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15407	----	Proofreading Team. THE CYDER-MAKER'S INSTRUCTOR, Sweet-Maker's Assistant, And Victualler's and Housekeeper's DIRECTOR. IN THREE PARTS. * * * * * PART I. Directs the grower to make his cyder in the manner foreign wines are made; to preserve its body and flavour; to lay on a colour, and to cure all its disorders, whether bad flavour'd, prick'd, oily, or ropy. PART II. Instructs the trader or housekeeper to make raisin-wines, at a small Expence, little (if any thing) inferior to foreign wines in strength or flavour; to cure their disorders; to lay on them new bodies, colour, &c. PART III. Directs the brewer to fine his beer and ale in a short time, and to cure them if prick'd or ropy. To which is added, A Method to make yest to ferment beer, as well as common yest, when that is not to be had. All actually deduced from the AUTHOR'S experience. By THOMAS CHAPMAN, _Wine-Cooper_. LONDON, Printed: BOSTON, Re-printed and Sold by GREEN & RUSSELL, in Queen-Street, MDCCLXII. [Price One Shilling.] THE PREFACE. It may be thought necessary, in compliance with custom, that I should say something by way of PREFACE. If the reader would be informed what my reasons were for appearing in print, I shall candidly acknowledge, that the great prospect of a considerable advantage to myself was indeed the strongest persuasive; but I can with equal truth affirm, that it affords me no small pleasure to think I am doing my country at the same time a very great piece of service; and doubt not but that, as many will soon experience it, my labour will be thankfully received and acknowledged. Discoveries and Improvements ought not to be concealed; the public good calls loudly for them; but then, in return for the great advantage the public receives from them, the author of any such discovery may with the greatest justice claim an adequate reward. PREFACE The following Receipts and Directions are not collected from books, nor interspersed with old women's nostrums; but they are, in very truth, the result of my own LONG EXPERIENCE in trade, founded on chemical principles, which are principles of never-erring nature. Perhaps I had never thought of this Method of communicating my little knowledge, had it not been for many gentlemen in the counties of _Gloucester, Hereford, Worcester_, &c. for whom I have done a great deal of business, in the cyder-way particularly; and who have often express'd their desire of seeing my directions for the management of cyders, &c. made public. And no doubt such a thing was wanting; for it's hardly credible how much liquors of almost every kind is spoiled by mismanagement. Few people know the nature of fermentation, without which no vinous spirit can be produced; nor any liquor be rendered fine and potible. Fermentation separates the particles of bodies, and from liquids throws off the gross parts from the finer, which, without it, could not be effected. There is what is called a _fret_, which is only a partial fermentation, that nature is strong enough in some liquors to bring on, without the assistance of art; but this _fret_, or partial fermentation, is never strong enough to discharge the liquor of its foul parts; and if they should ever happen to subside, the least alteration in weather, as well as a hundred other accidents, will occasion their commixing, and render the liquor almost, or altogether as foul as ever; to prevent which we call in the assistance of art, and which our method will effectually prevent. In brewing beer, yest is apply'd to it, in order to ferment it, without which it would never be beer. This opens the body of the liquor, and renders it spirity and fine. The reason that cyder is not often fine, is owing to its not being fermented. After it is got into the hogshead, the generality of people think they have acquitted themselves very well, and done all the necessary business, except racking it. But I can assure them, the more any liquor is rack'd, the more it is weaken'd. By often racking, it loseth its body, and so becomes acid for want of strength to support it. Another gross error many people are guilty of, in keeping the bungs out of the casks. Nothing is more pernicious to fermented liquors, than their being exposed to the open air, whereby they lose their strength and flavour. Take a bottle of wine, draw the cork, and let it stand exposed to the open air for twenty-four hours only, and you will then find it dead, flat, and insipid; for the spirit is volatile, and has been carried off by the air, and what remains is the gross, elementary part chiefly. A cyder-cask should never be kept open more than fourteen or fifteen days, that is, 'till the ferment is stopt; but so contrary is the practice, that I have known them very commonly kept open three or four months. It hath been objected to me by cyder and sweet-makers, that stopping up the cask so soon will endanger the head being blown out or bursted; but their fears are groundless, provided the ferment is stopt. The bottoms are quite confined, and it is impossible they should rise, unless a forcing be added to raise them. The best time for bottling your cyder, is in the winter, or cool weather, when it is _down_, otherwise you will hazard breaking most of the bottles. The best method of keeping it, is to put it up in dry saw-dust, which will keep it in a due temperature of heat, without the colour's subsiding, unless you have laid a high colour on it, which, by long keeping, will subside in the same manner port-wine doth in bottles. For 'tis impossible to set a colour on cyder so strong, as to have it stand the bottle more than twelve or eighteen months, at farthest. The natural colour will change but little in a much longer time. What I have said of the sweet-making-business, (which I have been constantly concerned in for more than twenty years) is principally relating to fermentation; for it is in all kinds of made-wines the chief thing to be observed. I shall just take notice here of one or two things, by way of caution. If your fruit be candied, the best way to clean them is by bagging, and then you may easily take the stems from them. It is very seldom that the fruit is all of the same goodness, I would therefore recommend, that the best fruit be made separate from the ordinary, it being easy, and much more prudent, to mix the liquors to your palate, than to run the hazard of making the good fruit with the bad, a small quantity of which will sometimes spoil the flavour of the liquor, and turn it acid. As to the method of brewing malt-liquors, I shall only here observe, that the practice of boiling the wort so long as is often done, is very injudicious. Five minutes is long enough: a longer time serves only to evaporate the spirit, without having any good effect. Under the head of malt-liquor, I have confined myself to giving proper instructions for curing their disorders, such as fining 'em, _&c._ which must be of great use to victuallers as well as private families, who, by reason of the badness of malt, mismanagement, bad weather, or other accidents, have frequently quantities by them, which for want of knowing how to cure, lie useless, and are sometimes thrown away. In the course of these receipts, I have endeavoured to lay down every thing as plain as possible, preferring, in these cases, plainness to elegance, even tho' I were capable of it, which indeed I have no pretensions to. Before I take leave of my reader, I must admonish him, that if my directions are not observed punctually, I will not be answerable for his success; for he may be assured, in matters of this kind, a great deal depends upon what many people think trifling, and of no consequence whether done or not. But on the other hand, if he will take care to observe them exactly, I am sure they will fully answer his expectations. So shall he not repent laying out his money on this _little_, but not the least _valuable_, book; nor will my reputation suffer in having penn'd it for his use; which is the earnest wish of His humble Servant, T.C. The _Cyder-Maker's_ Instructor. Let your fruit be as near the same ripeness as possible, otherwise the juice will not agree in fermenting. When they are properly sweated, grind and press them; and as soon as you have filled a cask, if a hogshead, which is one hundred and ten gallons, ferment it as follows; and if less, proportion the ingredients to your quantity. A FERMENT for CYDER. To one hogshead of cyder, take three pints of solid yest, the mildest you can get; if rough, wash it in warm water, and let it stand 'till it is cold. Pour the water from it, and put it in a pail or can; put to it as much jalap as will lay on a six-pence, beat them well together with a whisk, then apply some of the cyder to it by degrees 'till your can is full. Put it all to the cyder, and stir it well together. When the ferment comes on, you must clean the bung-holes every morning with your finger, and keep filling the vessel up. The ferment for the first five or six days will be black and stiff; let it stand till it ferments white and kind, which it will do in fourteen or fifteen days; at that time stop the ferment, otherwise it will impair its strength. To stop the FERMENT. In stopping this ferment, which is a very strong one, you must first rack it into a clean cask, and when pretty near full, put to it three pounds of course, red, scowering sand, and stir it well together with a strong stick, and fill it within a gallon of being full; let it stand five or six hours, then pour on it as softly as you can a gallon of English spirit, and bung it up close; but leave out the vent-peg a day or two. At that time just put it in the hole and close it by degrees till you have got it close. Let it lay in that state at least a year, and if very strong cyder, such as stire, the longer you keep it the better it will be in the body; and when you pierce it, if not bright, force it in the following manner. A FORCING for CYDER. Take a gallon of perry or stale beer, put to it one ounce of isinglass, beat well and cut or pull'd to small pieces; put it to the perry or beer, and let it steep three or four days. Keep whisking it together, or else the glass will stick to the bottom, and have no effect on the liquor. When it comes to a stiff jelly, beat it well in your can with a whisk, and mix some of the cyder with it, 'till you have made the gallon four; then put two pounds of brick rubbings to it, and stir it together with two gallons of cyder more added to it, and apply to the hogshead; stir it well with your paddle, and shive it up close. The next day give it vent, and you will find it fine and bright. If you force perry, cut your isinglass with cyder or stale beer, for no liquor will force its own body. To cure ACID CYDER. It is always to be observ'd, that even weak _alkali_'s cure the strongest acid, such, for instance, as calcin'd chalk, calcin'd oyster or scallop-shells, calcin'd egg-shells, alabaster, &c. But if a hogshead can soon be drank, use a stronger _alkali_, such as salt of tartar, salt of wormwood; but in using them, you must always preserve their colour with _lac_, or else the _alkali_ will turn the liquor black, and keep it foul. To one hogshead, take two gallons of _lac_, and put to it one ounce and a half of isinglass beat well and pulled small; boil them together for five or six minutes; drain it, and when a stiff jelly, break it with a whisk, and mix about a gallon of the cyder with it; then put three pounds of calcin'd chalk, and two pounds of calcined oyster-shells to it, whisk it well together with four gallons more of the cyder, and apply it to the hogshead. Stir it well, and it will immediately discharge the acid part out at the bung. Let it stand one hour, then bung it close for five or six days; rack it from the bottom into a clean hogshead, and apply one quart of forcing to it. If you use a strong _alkali_, put to the _lac_ four ounces of salt of tartar, or salt of wormwood; but the former is best, as it hath not the bitter taste in it which the wormwood has. _Note_, Lac _is milk, but the cream must be skimm'd off it for use_. To cure OILY CYDER. The reason that cyder is sometimes oily, is owing to the fruit not being sorted alike; for the juice of fruit that is not ripe will seldom mix with ripe juice in fermentation. The acid part of one will predominate over the other, and throw the oily particles from it, which separation gives the liquor a disagreeable, foul taste; to remedy which you must treat it in the following manner, which will cause the oily parts to swim at top, and then you may rack the liquor from its bottom and oil. To a hogshead, take an ounce of salt of tartar, and two ounces of half sweet spirit of nitre, mix them in a gallon of _lac_, and whisk them well together; apply it to the hogshead, bung it up, and let it stand ten or fifteen days; then put a cock within two inches of the bottom of the hogshead, and rack it. Observe when it runs low, to look to the cock, lest any of the oily part should come, which will be all on the top, and will not run out till after the good liquor is drawn off. Put to the clean a quart of forcing, to raise it, and bung it close. _Note_, When you take out the oil and bottom, your cask must be well fired, otherwise it will spoil all the liquor that shall be afterwards put into it. For ROPY CYDER. The following remedy for ropy cyder must be proportion'd with judgment to the degree of the disorder in the liquor. If the rope be stiff and stringy, you must use a larger quantity of the ingredients. If a hogshead be quite stiff and stringy, work it at least an hour with your paddle, then put to it six pounds of common allum, ground to a fine powder; work it for half an hour after, and bung it up close. This in a week will cut the rope and bring it to a fine, thin, fluid state. Then rack it into a clean hogshead, and put to it one quart of forcing; stir them well in the hogshead and bung it close up. If but a thin rope, use a less quantity of the allum, and work it the same way. CYDERS bad flavour'd. Some cyders in keeping are apt to get reasty, thro' the ill quality of the fruit; and sometimes thro' the badness of the cask will get musty, or fusty. To remedy these evils, you must throw it in ferment, if its body is strong, with yest and jalap, and let it ferment three or four days; which will throw off the greatest part of the taste; then stop the ferment. If a hogshead, put to it one pound of sweet spirit of nitre, and bung it up close. This will cure the bad flavour if any left, and likewise keep it from growing flat. To colour CYDER. In many places, particularly where the soil is light, and the orchard lays rising, the juice of the fruit is nearly white, and tho' the cyder may be strong, it doth not appear to be so, by reason of its colour, which always prejudices the buyer against it. Many people spoil a great deal of good cyder by boiling and mixing melasses with it, to give it a colour; which not only gives it a bad red colour, but makes it muddy, as well as bad tasted. Others, again, will boil a large quantity of brown sugar and mix with it, which gives it a colour indeed, tho' a light one; when two pounds of good sugar, properly used, is sufficient to colour ten hogsheads, as follows: Take two pounds of powder sugar, the whiter the sugar the farther it will go, and the better the colour will be. Put it in an iron pot or ladle; set it over the fire, and let it burn 'till it is black and bitter; then put two quarts of boiling hot water to it; keep stirring it about, and boil it a quarter of an hour after you have put the water to it. Take it off the fire, and let it stand 'till it is cold; then bottle it for use. Half a pint of this will colour a hogshead. Put to each half pint, when you use it, a quarter of an ounce of allum ground, to set the colour. PART II. The _Sweet-Maker's_ Assistant. Of RAISIN WINES. These wines are made of various kinds of fruit; of _Malaga's, Belvederes, Smyrna's, Raisins of the Sun_, &c. But the fruit that produces the best wines is black _Smyrna's_, their juice being the strongest, and the fruit clearest from stalks: for the stalks in _Malaga's_ and _Belvideres_ are apt to give the wine a bad flavour, and will always throw an acid on it; for the stalks of all fruits are acid; but the stalks of _Smyrna's_ are so trifling, that after rubbing the fruit between your hands, they will easily sift out. Wine made from this fruit is the colour of Madeira, and has very much the flavour of it. Malaga is the colour and flavour of foreign malaga, but nothing near so strong. Wine made from belvideres is strong and very sweet; and after keeping it four or five years is very little inferior to old mountain. In order to succeed in making these wines, you ought never to set your steeps in hot weather, because the heat will put the fruit in a fret which will injure its fermenting kindly. The best time for making is in January or February. Set your steeps in the coldest part of the cellar, still remembering to keep them from the frost. To every gallon of water put five pounds of fruit, if good; if but indifferent, put six pounds, into the steep. Keep stirring them three or four times a day, and let them continue in the steep till the fruit begins to burst, and the stones swim on the top; which will be in about fourteen or fifteen days. Then strain the liquor from the fruit, and press the fruit very dry, mixing the pressings with the rest of the liquor, and put all together into a cask, and ferment it in the following manner. To every pipe of wine take two quarts of solid ale yest and one ounce of jalap, put them into a can, and into them pour a gallon of the new wine first made hot, whisk them well together, and apply to the pipe, stirring all together very well. If your cask be less than a pipe, proportion your yest and jalap accordingly. When the ferment comes on, you must keep the bung-hole clean, and let the vessel be filled up three or four times a day. Let it ferment ten or twelve days, or till it works clean and white. Then take it off its bottom, which will be very considerable, and put it into a clean cask. You may filter the bottom thro' a linen rag and put to the wine. Lay some heavy weight over the bung, and let it stand a day. Then lay on the top of the wine five gallons of melasses-spirit, and bung it up close. Leave out the vent peg a day or two; then drop it in the hole, and close it by degrees 'till you have made it quite close. Let it lay in this state for six months, at that time rack it from its bottom into a clean pipe, and you'll find it tolerably fine. Then put to it one quart of _forcing_, and bung it up. Let it lay 'till within a month of your wanting it; for the longer it lays the better it will be in body. Then rack it for the last time (always observing you touch no bottoms) and put three pints of _forcing_ to it. Stir it well with your paddle, and bung it up. The bottoms you may run thro' a linen rag as before, and mix with that in the pipe. You may pierce the wine in six or seven days, and you will find it quite fine and bright. To force RAISIN WINES. For one pipe, take two quarts of good cyder; put half an ounce of ground allum to it, and one ounce of isinglass pulled to small pieces. Beat them well in your can three or four times a day, and let the mixture stand till it becomes a stiff jelly; then break it with your whisk, and add to it two pounds of white sand or stone dust. Then break it up gradually with some of the wine, 'till you have made the two quarts two gallons, stir it well together, and apply to the pipe, and bung up close. The sand will carry down with it all the small particles with the isinglass misses, and likewise confine the bottom so as to prevent it from rising. But if you make your wine stronger by allowing a larger quantity of fruit to the gallon, this _forcing_ will not do; for all _forcings_ must be stronger than the body forc'd, or else the foul parts will not fall; therefore such wines must be forced with _English stum_, a quart of which is sufficient for a pipe, one pound of alabaster being beat in with it and apply'd as above. ENGLISH STUM. Take a five gallon cask that has been well soaked in water, set it to drain; then take a pound of roll brimstone and melt in a ladle; put as many rags to it as will suck up the melted brimstone. Burn half those rags in the cask, covering the bung-hole so much as that it may have just air enough to keep it burning. When burnt out put three gallons of very strong cyder, and one ounce of common allum (pounded and mixt with the cyder) into the cask. Keep rolling the cask about five or six times a day for two days. Then take out the bung, and hang the remainder of the rags on a wire in the cask, as near the cyder as possible, and set them on fire as before. When burnt out, bung the cask close and roll it well about three or four times a day for two days; then let it stand seven or eight days, and this liquor will be so strong as to affect your eyes by looking at it. When you force a pipe, take one quart of this liquid, put half an ounce of isinglass to it beat and pulled to small pieces. Whisk it together, and it will dissolve in four or five hours. Break the jelly with your whisk, and put one pound of alabaster to it, then dilute it with some of the wine, put it in the pipe, bung it close, and in a day it will be fine and bright. To cure ACID RAISIN WINES. The following ingredients must be proportioned to the degree of acidity; if but small, you must use the less, if a stronger acid a larger quantity. It must likewise be proportioned to the quantity of wine as well as to the degree of acidity. Observe that your cask be nearly full before you apply the ingredients; which will have this good effect, the acid part of the wine will rise to the top immediately, and issue out at the bung-hole. But if the cask be not full, the part that should fly off will still continue in the cask, and weaken the body of the wine. If your cask be full, it will be fit to have a body laid on it, in three or four days time. I shall here proportion the ingredients for a pipe, supposing it quite acid, so as but just recoverable. Take two gallons of lac, and two ounces of isinglass, boil them a quarter of an hour; strain the liquor, and let it stand 'till it is cold; then break it well with your whisk, and put four pounds of alabaster and three pounds of whiting to it. Stir them well together, and add one ounce of salt of tartar to the whole. Mix by degrees some of the wine with it, so as to dilute it to a thin liquor. Apply this to the cask, and stir it well with your paddle. This will immediately discharge the acid part from it, as was said before. When it is off and quite down, bung it up for three days, then rack it, and you'll find part of its body gone off by the strong fermentation. To remedy this, you must lay a fresh body on it in proportion to the degree to which it hath been lower'd by the above process; always having special care not to alter flavour. And this must be done with clarified sugar; for no fluid body will agree with it but what will make it thinner, or confer its own taste; therefore the following is the best manner. To lay a fresh body on the WINES. Take three quarters of a hundred of brown sugar, and put into your copper, then put a gallon of lime water to it, to keep it from burning. Keep stirring it about 'till it boils; then take three eggs and mash all together with the Shells, which put to the sugar. Stir it about, and as the scum or filth arise take it off. When quite clean put it into your can, and let it stand 'till it is cold before you use it. Then break it with the whisk by degrees, with about ten gallons of the wine, and apply it to the pipe. Work it with your paddle for half an hour; then put one quart of _stum forcing_ to it, which will unite their bodies, and likewise make it fine and bright. You must keep it bung'd very close. To cure RAISIN WINES that are cloudy. These wines, if they take a chill, are affected in the same manner with Port-wines. Like them they will be cloudy, and will have a floating lee in them, which by shaking in a glass will rise in clouds. If any thing be apply'd to it cold, it will strike a greater chill upon it, and change its true colour to a pale or deep blue one; to prevent which, and take off the chill, you must, _For a Pipe_, Take one gallon of lac and one ounce of isinglass broke in small pieces, three pounds of alabaster, two ounces of sweet spirit of nitre; boil them together for five or six minutes; Stir them and apply to the pipe as hot as possible. Stir it well in the pipe with your paddle, and in about two hours after, bung it close up. Let it lay five or six days, and you'll find it quite fine and bright. This will make it a little flat, to remedy which you must rack it clean from it's bottoms, and throw a quart of _stum forcing_ to it. To colour RAISIN WINES. Wine made of raisins of the sun is always of the colour of rhenish, which is almost white. Very often that which is made of malaga's (especially if the fruit be but indifferent) will not hold its colour, but must have a colour laid on it. The right colour of raisin wine is the colour of mountain. You must take care that your wine has not a great bottom in it; for if it has, 'twill be longer before it falls fine. In order to lay a mountain colour on your wine, you must take three or four pounds of brown sugar, according to the quantity of wine you want to colour. Put it in an iron pan or iron ladle, set it over the fire, and keep stirring it about. Let it burn in this manner 'till it is quite black and bitter, which will be in about half an hour. If you burn one pound of sugar, put a quart of boiling hot water to it; stir it about, and let it boil a quarter of an hour longer, then take it off and let it cool. A pint of this mixture is sufficient to colour a pipe of wine; but note, that with every pint you must mix a quarter of an ounce of common allum pounded to a fine powder; which will set the colour so that it will not subside, other wise it will fall to the bottom, and have no good effect on the liquor. If you would have your wine of the colour of port, you must take eight ounces of logwood raspings, four ounces of alkanet root, one ounce of cochineal. Infuse them over a slow fire for three hours; strain the liquor from the wood, and keep it boiling. Then burn three pounds of brown sugar as before, and put the colour'd liquor to it; boil all together a quarter of an hour longer; then take it off, and when cold, bottle it for use. A pint of this liquor will make a pipe the colour of port wine. You must always remember to set the colour with a quarter of an ounce of common allum, ground or beaten to a fine powder. PART III THE _Housekeepers_ DIRECTOR. FORCING for BEER. There are two sorts of forcings for beer; for what will agree with one kind of beer will not serve for another. Some beer when kept twelve or fourteen months will taste as new and sweet as if not brew'd more than six or seven, nay a much shorter time, which must have a different forcing from that which is proper for beer that is ripe or less sweet. Beers that are full and sweet must be forc'd in the following manner, viz. For a hogshead, take a gallon of stale cyder, likewise one ounce of isinglass beat and pulled to small pieces, with an ounce of common allum ground to a fine powder, put them to the cyder; whisk it well together and let it stand 'till it's a jelly. Then break it in your can, and put one ounce of cream of tartar, and two pounds of stone-dust to it; whisk it well together, and dilute it with some of the beer till you have made the gallon five. Apply it to the hogshead, and stir it well about; and when the ferment is gone off (which will be in two or three hours) bung it up close. Leave out the vent-peg; and in a day or two you'll find it fine and bright. Beers that are not Sweet are forced with _stum_, the same that is made for raisin wine, with this difference only, that you must take for one hogshead, three pints, and two pounds of alabaster; stir them well together, and dilute with beer as above. This will carry down all the foul particles, and make the beer fine in three or four hours. * * * * * FORCING for ALE. ALE that is brew'd in the winter to be drank in about two months is apt to get foul, occasion'd by the brewer's neglecting it when cooling. Sometimes it is left out in the frost, which will chill it, and make it curdy as it were, and and foul; to remedy this you must Take two gallons of cyder, and put two ounces of insinglass to it. When it is a jelly, add to them two pounds of brick-rubbings; whisk them well together, and dilute with some of the ale. Put the whole in the hogshead, and stir all about very well. When the ferment is a little off, bung it close; the next day give it vent, and you'll find it fine. ALE or BEER ACID. If your beer or ale be a little prick'd, you must take for each hogshead a gallon of lac, boil it with an ounce of isinglass, drain it, and when cold, put to it two pounds of alabaster, two pounds of calcined chalk, and one ounce of salt of tartar. Stir them well together, and apply to the hogshead. Mind that the cask be full, and this will immediately discharge the acid part from it, (as in page 12.) Bung it up for three or four days 'till it is settled; then rack it into a clean hogshead, and put two quarts of _ale forcing_ to it, and bung it close. BEER or ALE ROPY, to cure. If beer or ale should at any time get ropy, as in other disorders, you must proportion the strength of your remedy to the degree of the disorder. But beer or ale is seldom known to be so ropy as cyder. Take, for one hogshead, two pounds of common allum in one lump, if possible; put it into a clear fire, and burn it an hour, then pound it, and apply to the hogshead. Stir it well for half an hour. This will cut the rope in a day or two; then rack it and force it with the same _stum forcing_ at is directed for beer that is not sweet, as in page 26. If the rope be but thin, one pound of allum will be sufficient. Hyssop will cut a thin rope in ale, but this always gives it a bad taste. To make YEST, to ferment new BEER. Many people that live at a distance from any town, are at a great loss, especially in the winter time, for yest to brew with; I shall therefore here give them directions to make an artificial yest that will answer the purpose altogether as well as the natural. Take two quarts of small beer and one ounce of isinglass; boil them together five or six minutes; put it into a can or pail, and whisk it till it comes to the consistence of yest; let it stand an hour after, then put it to your wort in the same manner you were used to do the natural yest; this will be sufficient to ferment a hogshead. THE END. 
15622	----	Proofreading Team. A HANDBOOK ON JAPANNING _FOR IRONWARE, TINWARE, WOOD, ETC._ WITH SECTIONS ON TIN-PLATING AND GALVANIZING BY WILLIAM N. BROWN _SECOND EDITION: REVISED AND ENLARGED WITH THIRTEEN ILLUSTRATIONS_ LONDON SCOTT, GREENWOOD AND SON "THE OIL AND COLOUR TRADES JOURNAL" OFFICES 8 BROADWAY, LUDGATE, E.C. 1913 D. VAN NOSTRAND COMPANY 8 WARREN ST., NEW YORK _First Edition under title "A Handbook on Japanning and Enamelling", 1901_ _Second Edition, Revised and Enlarged, under title "A Handbook on Japanning"--January, 1913_ CONTENTS. PAGE SECTION I. INTRODUCTION. 1-5 Priming or Preparing the Surface to be Japanned 4 The First Stage in the Japanning of Wood or of Leather without a Priming 5 SECTION II. JAPAN GROUNDS. 6-19 White Japan Grounds 7 Blue Japan Grounds 9 Scarlet Japan Ground 9 Red Japan Ground 10 Bright Pale Yellow Grounds 10 Green Japan Grounds 10 Orange-Coloured Grounds 11 Purple Grounds 11 Black Grounds 11 Common Black Japan Grounds on Metal 12 Tortoise-shell Ground 12 Painting Japan Work 13 Varnishing Japan Work 17 SECTION III. JAPANNING OR ENAMELLING METALS. 20-28 Enamelling Bedstead Frames and similar large pieces 24 Japanning Tin, such as Tea-trays and similar goods 25 Enamelling Old Work 27 SECTION IV. THE ENAMELLING AND JAPANNING STOVE--PIGMENTS SUITABLE FOR JAPANNING WITH NATURAL LACQUER--MODERN METHODS OF JAPANNING WITH NATURAL JAPANESE LACQUER. 29-48 Appliances and Apparatus used in Japanning and Enamelling 29 Modern Japanning and Enamelling Stoves 34 Stoves heated by direct fire 34 Stoves heated by hot-water pipes 36 Pigments suitable for Japanning with Natural Lacquer 45 White Pigments 45 Red Pigments 46 Blue Pigment 46 Yellow Pigments 46 Green Pigment 46 Black Pigment 46 Methods of Application 46 Modern Methods of Japanning and Enamelling with Natural Japanese Lacquer 47 SECTION V. COLOURS FOR POLISHED BRASS.--MISCELLANEOUS. 49-57 Painting on Zinc or on Galvanized Iron 49 Bronzing Compositions 49 Golden Varnish for Metal 51 Carriage Varnish 51 Metal Polishes 51 Black Paints 52 Black Stain for Iron 53 Varnishes for Ironwork 55 SECTION VI. PROCESSES FOR TIN-PLATING. 58-60 Amalgam Process 59 Immersion Process 59 Battery Process 59 Weigler's Process 60 Hern's Process 60 SECTION VII. GALVANIZING. 61-66 INDEX. 67-69 HANDBOOK ON JAPANNING. SECTION I. INTRODUCTION. Japanning, as it is generally understood in Great Britain, is the art of covering paper, wood, or metal with a more or less thick coating of brilliant varnish, and hardening the same by baking it in an oven at a suitable heat. It originated in Japan--hence its name--where the natives use a natural varnish or lacquer which flows from a certain kind of tree, and which on its issuing from the plant is of a creamy tint, but becomes black on exposure to the air. It is mainly with the application of "japan" to metallic surfaces that we are concerned in these pages. Japanning may be said to occupy a position midway between painting and porcelain enamelling, and a japanned surface differs from an ordinary painted surface in being far more brilliant, smoother, harder, and more durable, and also in retaining its gloss permanently, in not being easily injured by hot water or by being placed near a fire; while real good japanning is characterised by great lustre and adhesiveness to the metal to which it has been applied, and its non-liability to chipping--a fault which, as a rule, stamps the common article. If the English process of japanning be more simple and produces a less durable, a less costly coating than the Japanese method, yet its practice is not so injurious to the health. Indeed, it is a moot point in how far the Japanese themselves now utilize their classical process, as the coat of natural japan on all the articles exhibited at the recent Vienna exhibition as being coated with the natural lacquer, when recovered after six months' immersion in sea water through the sinking of the ship, was destroyed, although it stood perfectly well on the articles of some age. In the English method, where necessary, a priming or undercoat is employed. It is customary to fill up any uneven surface, any minute holes or pores, and to render the surface to be japanned uniformly smooth. But such an undercoat or priming is not always applied, the coloured varnish or a proper japan ground being applied directly on the surface to be japanned. Formerly this surface usually, if not always, received a priming coat, and it does so still where the surface is coarse, uneven, rough, and porous. But where the surface is impervious and smooth, as in the case of metallic surfaces, a priming coat is not applied. It is also unnecessary to apply such a coat in the case of smooth, compact, grained wood. The reason for using this coating is that it effects a considerable saving in the quantity of varnish used, and because the matter of which the priming is composed renders the surface of the body to be varnished uniform, and fills up all pores, cracks, and other inequalities, and by its use it is easy after rubbing and water polishing to produce an even surface on which to apply the varnish. The previous application of this undercoat was thus an advantage in the case of coarse, uneven surfaces that it formed a first and sort of obligatory initial stage in the process of japanning. This initial coating is still applied in many instances. But it has its drawbacks, and these drawbacks are incidental to the nature of the priming coat which consists of size and whiting. The coats or layers of japan proper, that is of varnish and pigment applied over such a priming coat, will be continually liable to crack or peel off with any violent shock, and will not last nearly so long as articles japanned with the same materials and altogether in the same way but without the undercoat. This defect may be readily perceived by comparing goods that have been in use for some time in the japanning of which an undercoat has been applied with similar goods in which no such previous coat has been given. Provided a good japan varnish and appropriate pigments have been used and the japanning well executed, the coats of japan applied without a priming never peel or crack or are in any way damaged except by violence or shock, or that caused by continual ordinary wear and tear caused by such constant rubbing as will wear away the surface of the japan. But japan coats applied with a priming coat crack and fly off in flakes at the slightest concussion, at any knock or fall, more especially at the edges. Those Birmingham manufacturers who were the first to practise japanning only on metals on which there was no need for a priming coat did not of course adopt such a practice. Moreover, they found it equally unnecessary in the case of papier-mâché and some other goods. Hence Birmingham japanned goods wear better than those goods which receive a priming previous to japanning. PRIMING or PREPARING THE SURFACE TO BE JAPANNED. The usual priming, where one is applied, consists of Paris white (levigated whiting) made into a thin paste with size. The size should be of a consistency between the common double size and glue, and mixed with as much Paris white as will give it a good body so that it will hide the surface on which it is applied. But in particular work glovers' or parchment size instead of common size is used, and this is still further improved by the addition of one-third of isinglass, and if the coat be not applied too thickly it will be much less liable to peel or crack. The surface should be previously prepared for this priming by being well cleaned and by being brushed over with hot size diluted with two-thirds of water, that is provided the size be of the usual strength. The priming is then evenly and uniformly applied with a brush and left to dry. On a fairly even surface two coats of priming properly applied should suffice. But if it will not take a proper water polish, owing to the uneven surface not being effectually filled up, one or more additional coats must be applied. Previous to the last coat being applied, the surface should be smoothed by fine glass paper. When the last coat of priming is dry the water polish is applied. This is done by passing a fine wet rag or moistened sponge over the surface until the whole appears uniformly smooth and even. The priming is now complete and the surface ready to take the japan ground or the coloured varnish. THE FIRST STAGE IN THE JAPANNING OF WOOD OR OF LEATHER WITHOUT A PRIMING. [The leather is first securely stretched on a frame or board.] In this case, that is when no priming coat is previously applied, the best way to prepare the surface is to apply three coats of coarse varnish (1 lb. seed-lac, 1 lb rosin to 1 gallon methylated spirit, dissolve and filter). This varnish, like all others formed from methylated spirits, must be applied in a warm place and all dampness should be avoided, for either cold or moisture chills it and thus prevents it taking proper hold of the surface on which it is applied. When the work is prepared thus, or by the priming made of size and whiting already described, the japan proper is itself applied. SECTION II. JAPAN GROUNDS. The japan ground properly so called consists of the varnish and pigment where the whole surface is to be of one simple colour, or of the varnish, with or without pigment, on which some painting or other form of decoration is afterwards to be applied. It is best to form this ground with the desired pigment incorporated with shellac varnish, except in the case of a white japan ground which requires special treatment, or when great brilliancy is a desideratum and other methods must be adopted. The shellac varnish for the japan ground is best prepared as follows: shellac 1-1/4 lb., methylated spirits 1 gallon. Dissolve in a well-corked vessel in a warm place and with frequent shaking. After two or three days the shellac will be dissolved. It is then recommended to filter the solution through a flannel bag, and when all that will come through freely has done so the varnish should be run into a proper sized vessel and kept carefully corked for use. The bag may then be squeezed with the hand till the remainder of the fluid varnish is forced through it, and this if fairly clear may be used for rough purposes or added to the next batch. Pigments of any nature whatever may be used with the shellac varnish to give the desired tint to the ground, and where necessary they may be mixed together to form any compound colour, such as blue and yellow to form green. The pigments used for japan grounds should all be previously ground very smooth in spirits of turpentine, so smooth that the paste does not grate between the two thumb nails, and then only are they mixed with the varnish. This mixture of pigment and varnish vehicle should then be spread over the surface to be japanned very carefully and very evenly with a camel-hair brush. As metals do not require a priming coat of size and whiting, the japan ground may be applied to metallic surfaces forthwith without any preliminary treatment except thorough cleansing, except in the cases specially referred to further on. On metallic surfaces three to four coats are applied, and in the interval between each coat the articles must be stoved in an oven heated to from 250° to 300° F. WHITE JAPAN GROUNDS. The formation of a perfectly white japan ground and of the first degree of hardness has always been difficult to attain in the art of japanning, as there are few or no substances that can be so dissolved as to form a very hard varnish coat without being so darkened in the process as to quite degrade or spoil the whiteness of the colour. The following process, however, is said to give a composition which yields a very near approach to a perfect white ground: Take flake white or white lead washed and ground up with the sixth of its weight of starch and then dried, temper it properly for spreading with mastic varnish made thus: Take 5 oz. of mastic in powder and put it into a proper vessel with 1 lb. of spirits of turpentine; let them boil at a gentle heat till the mastic be dissolved, and, if there appear to be any turbidity, strain off the solution through flannel. Apply this intimate and homogeneous mixture on the body to be japanned, the surface of which has been suitably prepared either with or without the priming, then varnish it over with five or six coats of the following varnish: Provide any quantity of the best seed-lac and pick out of it all the clearest and whitest grains, take of this seed-lac 1/2 lb. and of gum anime 3/4 lb., pulverize the mixture to a coarse powder and dissolve in a gallon of methylated spirits and strain off the clear varnish. The seed-lac will give a slight tint to this varnish, but it cannot be omitted where the japanned surface must be hard, though where a softer surface will serve the purpose the proportion of seed-lac may be diminished and a little turpentine oleo-resin added to the gum anime to take off the brittleness. A very good varnish entirely free from brittleness may, it is said, be formed by dissolving gum anime in old nut or poppy oil, which must be made to boil gently when the gum is put into it. After being diluted with turps the white ground may be applied in this varnish, and then a coat or two of the varnish itself may be applied over it. These coats, however, take a long time to dry, and, owing to its softer nature, this japanned surface is more readily injured than that yielded by the shellac varnish. According to Mr. Dickson, "the old way of making a cream enamel for stoving (a white was supposed to be impossible) was to mix ordinary tub white lead with the polishing copal varnish and to add a modicum of blue to neutralize the yellow tinge, stove same in about 170°F. and then polish as before described". "This," continues Mr. Dickson, "would at the best produce but a very pale blue enamel or a cream. It was afterwards made with flake white or dry white lead ground in turps only and mixed with the polishing copal varnish with the addition of tints as required, by which means a white of any required character could be produced." BLUE JAPAN GROUNDS. Authorities state that these may be formed from bright Prussian blue or verditer glazed over with Prussian blue or of smalt. By bright Prussian blue possibly a genuine Prussian blue toned down to a sky blue with white lead is meant, and by verditer the variety known as refiners' blue verditer, and as to smalt it must not be forgotten that it changes its colour in artificial light. Be that as it may, the pigment may be mixed with the shellac varnish according to the instructions already given, but as the shellac will somewhat injure the tone of the pigment by imparting a yellow tinge to it where a bright true blue is required, the directions already given as regards white grounds must be carried out. SCARLET JAPAN GROUND. Vermilion is the best pigment to use for a scarlet japan ground, and its effect will be greatly enhanced by glazing it over with carmine or fine lake. If, however, the highest degree of brightness be required the white varnish must be used. Vermilion must be stoved at a very gentle heat. RED JAPAN GROUND. The basis of this japan ground is made up with madder lake ground in oil of turpentine, this constitutes the first ground; when this is perfectly dry a second coat of lake and white in copal varnish is applied, and the last coat is made up of lake in a mixture of copal varnish and turpentine varnish. BRIGHT PALE YELLOW GROUNDS. Orpiment or King's yellow may be used, and the effect is enhanced by dissolving powdered turmeric root in the methylated spirits from which the upper or polishing coat is made, which methylated spirits must be strained from off the dregs before the seed-lac is added to it to form the varnish. The seed-lac varnish is not so injurious to yellow pigments as it is to the tone of some other pigments, because, being tinged a reddish yellow, it does little more than intensify or deepen the tone of the pigment. GREEN JAPAN GROUNDS. Green japan grounds are produced by mixing Prussian blue or distilled verdigris with orpiment, and the effect is said to be extremely brilliant by applying them on a ground of leaf gold. Any of them may be used with good seed-lac varnish, for reasons already given. Equal parts by weight of rosin, precipitated rosinate of copper, and coal-tar solvent naphtha will give a varnish which, when suitably thinned and the coats stoved at a heat below 212° F., will give a green japan second to none as a finishing coat as regards purity of tone at least. To harden it and render it more elastic half of the rosin might be replaced by equal weights of a copal soluble in solvent naphtha and boiled linseed oil, so that the mixture would stand thus: rosinate of copper 1 lb., rosin 1/2 lb., boiled oil 1/4 lb., hard resin (copal) 1/4 lb., solvent naphtha 1 lb. When heated to a high temperature this rosinate of copper varnish yields a magnificent ruby bronze coloration, especially on glass. Verdigris dissolves in turpentine, and successful attempts might be made to make a green japan varnish from it on the lines indicated for rosinate of copper. ORANGE-COLOURED GROUNDS. Orange-coloured grounds may be formed by mixing vermilion or red lead with King's yellow, or orange lake or red orpiment (? realgar) will make a brighter orange ground than can be produced by any mixture. PURPLE GROUNDS. Purple grounds may be produced by the admixture of lake or vermilion with Prussian blue. They may be treated as the other coloured grounds as regards the varnish vehicle. BLACK GROUNDS. Black grounds may be formed either from lamp black or ivory black, but ivory black is preferable to lamp black, and possibly carbon black or gas black to either. These may be always applied with the shellac varnish as a vehicle, and their upper or polishing coats may consist of common seed-lac varnish. But the best quality of ivory black ground in the best super black japan yields, after suitable stoving, a very excellent black indeed, the purity of tone of which may be improved by adding a little blue in the grinding. COMMON BLACK JAPAN GROUNDS ON METAL. Common black japan grounds on metal by means of heat are procured in the following manner: The surface to be japanned must be coated over with drying oil, and when it is moderately dry must be put into a stove of such heat as will change the oil black without burning it. The stove should not be too hot when the oil is put into it nor the heat increased too fast, either which error would make it blister, but the slower the heat is increased and the longer it is continued, provided it be restrained within a due degree, the harder will be the coat of japan. This kind of japan requires no polish, having received from the heat, when properly regulated, a sufficiently bright surface. TORTOISE-SHELL GROUND. This beautiful ground, produced by heat, is valued not only for its hardness and its capacity to stand a heat greater than that of boiling water, but also for its fine appearance. It is made by means of a varnish prepared thus: Take one gallon of good linseed oil and half a pound of umber, boil them together until the oil becomes very brown and thick, strain it then through a coarse cloth and set it again to boil, in which state it must be continued until it acquires a consistency resembling that of pitch; it will then be fit for use. Having thus prepared the varnish, clean well the surface which is to be japanned; then apply vermilion ground in shellac varnish or with drying oil, very thinly diluted with oil of turpentine, on the places intended to imitate the more transparent parts of the tortoise-shell. When the vermilion is dry, brush the whole over with the black varnish thinned to the right consistency with oil of turpentine. When set and firm put the work into a stove where it may undergo a very strong heat, which must be continued a considerable time, for three weeks or even a month so much the better. This ground may be decorated with painting and gilding in the same way as any other varnished surface, which had best be done after the ground has been hardened, but it is well to give a second annealing at a very gentle heat after it has been finished. A very good black japan may be made by mixing a little japan gold size with ivory or lamp-black, this will develop a good gloss without requiring to be varnished afterwards. PAINTING JAPAN WORK. Japan work should be painted with real "enamel paints," that is with paints actually ground in varnish, and in that case all pigments may be used and the peculiar disadvantages, which attend several pigments with respect to oil or water, cease with this class of vehicle, for they are secured by it when properly handled from the least danger of changing or fading. The preparation of pigments for this purpose consists in bringing them to a due state of fineness by grinding them on a stone with turpentine. The best varnish for binding and preserving the pigments is shellac. This, when judiciously handled, gives such a firmness and hardness to the work that, if it be afterwards further secured with a moderately thick coat of seed-lac varnish, it will be almost as hard and durable as glass. The method of painting in varnish is, however, far more tedious than with an oil or water vehicle. It is, therefore, now very usual in japan work for the sake of dispatch, and in some cases in order to be able to use the pencil (brush) more freely, to apply the colours in an oil vehicle well diluted with turps. This oil (or japanners' gold size) may be made thus: Take 1 lb. of linseed oil and 4 oz. of gum anime, set the oil in a proper vessel and then add the gum anime powder, stirring it well until the whole is mixed with the oil. Let the mixture continue to boil until it appears of a thick consistence, then strain the whole through a coarse cloth and keep it for use. The pigments are also sometimes applied in a gum-water vehicle, but work so done, it has been urged, is not nearly so durable as that done in varnish or oil. However, those who formerly condemned the practice of japanning water-coloured decorations allowed that amateurs, who practised japanning for their amusement only and thus might not find it convenient to stock the necessary preparations for the other methods, might paint with water-colours. If the pigments are ground in an aqueous vehicle of strong isinglass size and honey instead of gum water the work would not be much inferior to that executed with other vehicles. Water-colours are sometimes applied on a ground of gold after the style of other paintings, and sometimes so as to produce an embossed effect. The pigments in this style of painting are ground in a vehicle of isinglass size corrected with honey or sugar-candy. The body with which the embossed work is raised is best formed of strong gum water thickened to a proper consistency with armenian bole and whiting in equal parts, which, being laid on in the proper figures and repaired when dry, may be then painted with the intended pigments in the vehicle of isinglass size or in the general manner with shellac varnish. As to the comparative value of pigments ground in water and ground in oil, that is between oil-colours and water-colours in enamelling and japanning, there seems to have been a change of opinion for some time back, especially as regards the enamelling of slate. The marbling of slate (to be enamelled) in water-colours is a process which Mr. Dickson says well repays study. It is greatly developed in France and Germany. The process is a quick one and the pigments are said to stand well and to maintain their pristine hue, yet if many strikingly natural effects result from the use of this process, its use has not spread in Great Britain, being confined wholly and solely to the marbling of slate (except in the case of wall-paper which is water-marbled in a somewhat similar way). "In painting in oil-colour," says Mr. Dickson, "the craftsman trusts largely to his badger-hair brush to produce his effects of softness and marbly appearance; but in painting in water-colours, this softness, depth, and marbly appearance are produced mostly by the colour placed upon the surface, and left entirely untouched by badger or any other brush. The colour drying quickly, does not allow much time for working, and when dry it cannot be touched without spoiling the whole of the work. The difference first of all between painting in water and in oil colour, is that a peculiar grain exists with painting in water that it is absolutely impossible to get in oil. The charm of a marble is, I think, its translucency as much as its beautiful colour; it is to that translucency (for in marble fixed we have no transparency) that it owes its softness of effect, which makes marble of such decorative value. This translucency can only be obtained by thin glazes of colour, by which means each succeeding glaze only partly covers the previous one, the character of the marble being thus produced. This is done sometimes in oil-colour in a marvellous manner, but even the best of oil-painting in marble cannot stand the comparison of water-colour, and it is only by comparison that any accurate judgment can be formed of any work. The production of marbles in water-colour has a depth, softness, and stoniness that defies oil-painting, and in some cases will defy detection unless by an expert of marbles. It may be that first of all the materials employed are more in keeping with the real material, as no oil enters into the composition of real marble, and by using the medium of water we thus start better, but the real secret is that by using water as a medium the colours take an entirely different effect. In painting in water-colour greys of any tint or strength can be obtained suitable for the production of a marble of greyish ground, by pure white, tinted as required, being applied of different thicknesses of colour, all the modulations of tone being obtained by the difference in the thickness of the colour applied." VARNISHING JAPAN WORK. Varnishing is the last and the finishing process in japanning. It consists in (1) applying, and (2) polishing the outer coats of varnish, which are equally necessary whether the plain japan ground be painted on or not. This is best done in a general way with common seed-lac varnish, except on those occasions where other methods have been shown to be more expedient, and the same reasons, which decide as to the propriety of using the different varnishes as regards the colours of the ground, hold equally with those of the painting, for where brightness is a material point and a tinge of yellow would injure it, seed-lac must give way to the whiter resins; but where hardness and tenacity are essential it must be adhered to, and where both are necessary a mixed varnish must be used. This mixed varnish should be made from the picked seed-lac as directed in the case of the white japan grounds. The common seed-lac varnish may be made thus: Take 1-1/2 lb. of seed-lac and wash it well in several waters, then dry it and powder it coarsely and put it with a gallon of methylated spirits into a Bohemian glass flask so that it be not more than two-thirds full. Shake the mixture well together and place the flask in a gentle heat till the seed-lac appears to be dissolved, the shaking being in the meantime repeated as often as may be convenient; then pour off all the clear and strain the remainder through a coarse cloth. The varnish so prepared must be kept for use in a well-corked glass vessel. The whiter seed-lac varnishes are used in the same manner as the common, except as regards the substances used in polishing, which, where a pure white or the greater clearness or purity of other pigments is in question, should be itself white, while the browner sorts of polishing dust, as being cheaper and doing their business with greater dispatch, may be used in other cases. The pieces of work to be varnished should be placed near the fire or in a warm room and made perfectly dry, and then the varnish may be applied with a flat camel-hair brush made for the purpose. This must be done very rapidly, but with great care; the same place should not be passed twice over in laying on one coat if it can possibly be avoided. The best way of proceeding is to begin in the middle and pass the brush to one end, then with another stroke from the middle pass it to the other end, taking care that before each stroke the brush be well supplied with varnish; when one coat is dry another must be laid over it in like manner, and this must be continued five or six times. If on trial there be not a sufficient thickness of varnish to bear the polish without laying bare the painting or ground colour underneath more varnish must be applied. When a sufficient number of coats of varnish is so applied the work is fit to be polished, which must be done in common work by rubbing it with a piece of cloth or felt dipped in tripoli or finely ground pumice-stone. But towards the end of the rubbing a little oil of any kind must be used with the powder, and when the work appears sufficiently bright and glossy it should be well rubbed with the oil alone to clean it from the powder and to give it a still greater lustre. In the case of white grounds, instead of the tripoli, fine putty or whiting should be used, but they should be washed over to prevent the danger of damaging the work from any sand or any other gritty matter that may happen to be mixed with them. It greatly improves all kinds of japan work to harden the varnish by means of heat, which, in every degree that can be applied short of what would burn or calcine the matter, tends to give it a firm and strong texture where metals form the body; therefore a very hot stove may be used, and the stoving may be continued for a considerable time, especially if the heat be gradually increased. But where wood or papier-mâché is in question, heat must be applied with great caution. SECTION III. JAPANNING OR ENAMELLING METALS. In japanning metals, all good work of which should be stoved, they have to be first thoroughly cleaned, and then the japan ground applied with a badger or camel-hair brush or other means, very carefully and evenly. Metals usually require from three to five coats, and between each application must be dried in an oven heated from 250° to 300° F.--about 270° being the average. It has already been seen that the best grounds for japanning are formed of shellac varnish, the necessary pigments for colouring being added thereto, being mixed with the shellac varnish after they have been ground into a high degree of smoothness and fineness in spirits of turpentine. In japanning it is best to have the oven at rather a lower temperature, increasing the heat after the work has been placed in the oven. When a sufficient number of coats have been laid on--which will usually be two only--the work must be polished by means of a piece of cloth or felt dipped in tripoli or finely powdered pumice-stone. For white grounds fine putty powder or whiting must be employed, a final coat being afterwards given, and the work stoved again. The last coat of all is one of varnish. And here, as a preliminary remark, it is advisable that all enamels and japans should be purchased ready-made, as any attempt to make such is almost sure to end in disaster, while, owing to the fact that such are only required for small jobs; it would involve too much trouble and would not pay. It is for this reason that few japan recipes are given, as, although many are available, they do not always turn out as suitable for the purpose as could be desired, in addition to which the ready-made articles can be purchased at a very reasonable price and are much better prepared. The operator should procure his enamels a shade or two lighter than he desires to see in the finished article, allowing the chemical action due to the stoving to tone the colours down. Another necessity is to keep the enamel thoroughly well mixed by well stirring it every time it is used, as if this is not done the actual colouring matter is apt to sink to the bottom, the ultimate result being that streaky work is produced in consequence of this indifferent mixing of the enamelling materials. It is hardly necessary to state that all japanning or enamelling work must be done in a room or shop absolutely free from dust or dirt, and as far away as possible from any window or other opening leading to the open air, for two reasons--one being that the draught therefrom may cool the oven or stove, and the other that the air may convey particles of dust into the enamelling shop. In fact, it cannot be too much impressed upon the workmen that one of the primary secrets of successful enamelling is absolute cleanliness; consequently all precautions must be taken to ensure that the enamel is perfectly free from grit and dust, and it must be so kept by frequent straining through fine muslin, flannel, or similar material. The work having been thoroughly cleaned and freed from all grease and other foreign matter, it must be suspended or held immediately over the pan elsewhere referred to, and the enamel poured on with an ordinary iron ladle, or covered by means of the brush. When it has been permitted to drain thoroughly, the work should be hung on the hooks on the rods in the oven as seen in the explanatory sketch, care being observed that no portion of the work is in such a position that any superfluous enamel cannot easily drain off--in other words, the work must lie or hang that it is always, as it were, on the slant. Always bear in mind when shutting the oven door to do so gently, as if a slam is indulged in all the gas jets will be blown out, and an explosion would probably result. Should the job in hand be a large one, it will be found as well to get a cheaper enamel for the first coat, but if the work is only a small job, it will not be necessary to have more than one enamel, of which a couple of coats at least will be required. When the first coat has thoroughly dried and hardened, the surface will have to be thoroughly rubbed till it is perfectly smooth with tripoli powder and fine pumice-stone, and afterwards hand-polished with rotten-stone and putty powder. And here it may be remarked that the finer the surface is got up with emery powder and other polishing agents the better will be the enamelling and ultimate finish. The rubbing down being finished, another coat of enamel must be applied and the work baked as before, care being always taken to keep the enamel in a sufficiently fluid condition as to enable it to flow and run off the work freely. It can easily be thinned with a little paraffin. A third coat will frequently be advisable, as it improves the finish. In enamelling cycles, it is well to hang the front forks crown uppermost when they are undergoing the final baking, and it is advisable to bear in mind that wheels require an enamel that will stove at a lower temperature than is called for for other parts of the machine. Some japanners advocate the fluid being put on with camel-or badger-hair brushes, and for the best descriptions of work, final coats, and such like, I agree with them; but this is a detail which can be left to the operator's own fancy, the class of work, etc.; but I would remind him that applying enamel with a brush requires much care and a certain amount of "knack". It is something like successful lacquering in brasswork--it looks very simple, but is not. Each succeeding coat of japan gives a more uniform and glossy surface, and for this reason it may, in some cases, be necessary to repeat the operation no fewer than half a dozen times, the final coat being generally a layer of clear varnish only, to add to the lustre. Care must be taken for light-coloured japans or enamels not to have the temperature sufficiently high to scorch, or the surface will be discoloured, as they require a lower temperature for fixing than the dark japans, which, provided the article is not likely to be injured by the heat, are usually dried at a somewhat high temperature. The preceding instructions apply only to the best descriptions of work. When pouring enamel by means of the ladle over pieces of work, do not agitate the liquid too much--at the same time taking care to keep it well mixed--so as to form air bubbles, as this will cause trouble, and in pouring over the work do it with an easy and gentle and not too hurried a motion. In japanning curved pieces, such as mud-guards, etc., in hanging up the work in the oven see that the liquid does not run to extremities and there form ugly blots or blotches of enamel. When white or other light tones are used for japanning they are mixed with japanners' varnish, and these require more careful heating in the oven or stove than darker tints or brown or black. [Illustration: FIG. 1.--Trough for Dipping Bedstead Frames and other Large Work.] ENAMELLING BEDSTEAD FRAMES AND SIMILAR LARGE PIECES. At Fig. 1 is shown a trough in which large pieces, such as bedsteads, bicycle frames, etc., are dipped or immersed. For the first-mentioned class of work such high finish is not required as for bicycles, and consequently the enamel need not be applied with a brush, nor will it be necessary to rub down the work between each coat, but instead the pieces can be literally dipped in the tank of liquid, then allowed to drain on to the dripping-board--the superfluous enamel thus finding its way back into the trough or tank, the dripped articles being afterwards placed in the oven to harden. The trough must be of sufficient dimensions to allow the pieces of work to be completely immersed, and the dripping-board should be set at an angle of about 45°. Bedstead frames will never require more than two coats and the commoner class of goods only one. I would not advise the tradesman in a small way of business to go to the expense of a trough, etc., as it calls for much more room than is ordinarily available, but if he has the necessary plant for bicycle work he can, of course, do an occasional job of the other kind. JAPANNING TIN, SUCH AS TEA-TRAYS AND SIMILAR GOODS. For japanning sheet-iron articles, which are really tin goods, such as tea-trays and similar things, first scour them well with a piece of sandstone, which will effectually remove all the scales and make the surface quite smooth. Then give the metal a coating of vegetable black, which must be mixed with super black japan varnish, thinned with turps, and well strained. Only a small quantity of this varnish is necessary, as it will dry dead. The article must then be placed in the stove to harden at a temperature of 212° F., there to remain for from ten to twelve hours. When taken out of the stove, the articles must be allowed to get cold, after which they must be given a coat of super black japan, which, if necessary, must be thinned with turps, a stiff, short bristle brush being employed, and the varnish put on sparingly, so that it will not "run" when it gets warm. Two coats of this varnish on top of the vegetable black coating are usually sufficient, when done properly, but a third coating much improves the work, and from ten to twelve hours' hardening will be necessary between each coating. The small lumps which will be more or less certain to arise will require to be rubbed down between each application by a small and smooth piece of pumice-stone. If it is desired to add gold or bronze bands or any kind of floral or other kind of fancy decorations, these are painted on, after the ground japanning has been done, in japanners' gold size, and then the gold leaf is applied, or the bronze or other metal powder is dusted on, after which the objects so treated are again placed in the stove, where they will not require to be kept near so long as for ordinary japanning. After they have been removed, the gilt or bronzed portions must be treated with a protecting coat of white spirit varnish. Transfers can be applied in the same way. Tinned iron goods are the most largely japanned, and for these brown and black colours are principally employed. Both are obtained by the use of brown japan, the metal having a preliminary coating of black paint when black is required. Only one coating of brown japan is given to cheap goods, but for better articles two or more are applied. For these it is possible that a final dressing with pumice-stone, then with rotten-stone, and rubbed with a piece of felt or cloth, or even the palm of the hand, may be necessary, but as a rule not. Large numbers of articles of the above description, such as tea-trays, tea-canisters, cash-boxes, coal-boxes, and similar goods, are japanned at Birmingham, and it is to such that the preceding instructions apply. ENAMELLING OLD WORK. In all cases of re-enamelling old work, it is absolutely necessary to remove all traces of the first enamelling, and if this has been well done in the first instance, it will prove no mean job. The best way to clean the work is to soak it in a strong "lye" of hot potash, when the softened enamel can be wiped or brushed off--this latter method being pursued in the more intricate and ungetatable portions of the work. New work, which has not been enamelled, can be treated in the same way for the removal of all grease, stains, finger-marks, etc., and too much attention cannot be paid to the initial preparation of the surface of the metal, to have it thoroughly even and smooth, as it adds so much to the ultimate finish and appearance of the work. Plenty of labour must be bestowed before the final coat, as any blemish will show through this finishing, and so mar what would otherwise be a highly satisfactory bit of work. In all kinds of bicycle work, whether new or old, the most satisfactory results are obtained by the application of at least two, and sometimes four or five, successive coats of good but thin enamel, as this will impart the necessary perfect coat, combined with durability, a high finish, and a good colour. A good enamel should be sufficiently hard, so as not to be scratched on the merest touch or rubbing. It will, of course, be understood that no solder-work must be put into the stove, or the pieces will separate. Should any of this work be discovered, the pieces must be taken apart, and then brazed together before being enamelled, and put in the stove. SECTION IV. THE ENAMELLING AND JAPANNING STOVE--PIGMENTS SUITABLE FOR JAPANNING WITH NATURAL LACQUER--MODERN METHODS OF JAPANNING WITH NATURAL JAPANESE LACQUER. APPLIANCES AND APPARATUS USED IN JAPANNING AND ENAMELLING. Besides the various enamels or japans and varnishes of various colourings and the stove, which will be found described and illustrated, together with the trough, in other pages, the worker will need some iron pots or cauldrons in which to boil the potash "lye" for the cleansing, more particularly, of old work, some iron ladles both for this work and for pouring the japan on the articles to be covered therewith, a few badger tools and brushes for small fine work, some hooks for the stove, a pair of pliers, a few bits of broom handle cut into short lengths and made taper, so as to fit into the tubes, etc., of bicycles and other work, so as to keep the hands as free from the japan as possible, some emery powder, pumice-stone powder, tripoli, putty powder, whiting, and a piece of felt or cloth. If he is also doing any common work, a stumpy brush of bristles and a soft leather will also be requisite, together with a file or two. These will about comprise the whole of the articles required, not very expensive, all of which will really not be required by a beginner. Owing largely to the strides made in the cycle trade enamelling is stoved by means of gas, and of this a plentiful supply is necessary. Enamelling stoves may really be described as hot-air cupboards or ovens, and for a stove which will answer most requirements--say one of 6 feet by 6 feet by 3-1/2 feet--six rows of atmospheric burners will be necessary to heat it, while it will be also advisable to fix pipes of 1-1/4 inch internal diameter from the gas meter to the stove. The atmospheric burners can be made from the requisite number of pieces of 1-1/4-inch gas tube 3-1/2 feet in length, one end of each being stopped, and having 1/3-inch holes drilled therein at intervals of about 1 inch, the other end being left open for the insertion of ordinary 3/8-inch brass gas taps. Another plan preferred by some japanners is to have three rows of burners the full length of the stove, which, under some circumstances, due to structural conditions, will be found more suitable. Anyway, whatever the position of the stove, allowance must be made for a temperature up to 400° F. to be raised. In old-fashioned ovens the heat is applied by means of external flues, in which hot air or steam is circulated, but this system is generally unsatisfactory, the supply of heat having to be controlled by dampers or stop-cocks, and this has given place to the gas apparatus. Another simple form of oven, though not one which I shall recommend, is a species of sheet-iron box, which is encased by another and larger box of the same shape, so placed that from 2 to 3 inches of interspace exists between the two boxes. To this interspace heat is applied, and a flue will have to be affixed to this apparatus to carry off the vapours which arise from the enamel or japan. For amateur or intermittent jobbing work the oven illustrated in Figs. 2 and 3 is about as good as any, though to guard against fire it would be as well to have a course of brickwork beneath the oven, while if this is not possible on account of want of height, a sheet or so of zinc or iron will help to mitigate the danger. It is also advisable, if the apartment is a low-pitched one, to have a sheet of iron or zinc suspended by four corner chains from the ceiling in order to protect this from firing through the heat from the enamelling oven. Of course, it will be understood that every portion of the stove must be put together with rivets, no soldered work being permissible. [Illustration: FIG. 2.--Door of Oven when Shut.] To those who wish to construct their own stove, it will be found that the framework can be shaped out of 1-inch angle iron, the panels or walls being constructed of sheet-iron of about 18 gauge, the whole being riveted together. The front will be occupied in its entire space by a door, which will require to be hung on strong iron hinges, and the framework of this door should be constructed of 1 inch by 1/4 inch iron--a rather stouter material will really be no disadvantage--to which the sheet-iron plates must be riveted. In the centre of the door must be cut a slit, say 1-1/2 inches by 9 inches, which will require to be covered with mica or talc behind which must be placed the thermometer, so as it can be seen during the process of stoving, without the necessity of opening the door, which, of course, more or less cools the oven. And, by the way, this thermometer must register higher than the highest temperature the oven is capable of reaching. Above is shown a sketch of the stove, interior and exterior, which will give an idea of what a japanner's stove is like. [Illustration: FIG. 3--Showing Stove when Open, and Back of Door.] Inside the stove it will be necessary to fix rows of iron rods, some four inches from the top, from which to suspend the work, or angle-iron ledges can be used on which the rods or bars can be fixed, these arrangements being varied according to the particular description of work, individual fancy, or other circumstances. Large S hooks are about the handiest to use. A necessary adjunct of the stove is a pan, which can be made by any handy man or tinworker, which should be made to fit the bottom of the stove above the gas jets, it being arranged that it rests on two side ledges, or along some rods. One a couple of inches in depth will be found sufficient, and it will repay its cost in the saving of enamel, it being possible with its use to enamel a bicycle with as little as a gallon of enamel. Some workmen have the tray made with a couple of hinged side flaps, to turn over and cover up the pan when not in use, but this is a matter of fancy. Of course, they must always be covered up when not in use. For those who would prefer to use Bunsen burners, I show at Fig. 4 a sketch of the best to employ, these having three rows of holes in each. [Illustration: FIG. 4.--Bunsen Burner.] When brick ovens are employed they must be lined with sheet-iron, and in these very rare circumstances where gas is not available, the stove can be heated with coal or wood, which will, of course, involve a total alteration in the structural arrangements. I have not given the details here, as I do not think the necessity will ever arise for their use, and for the same reason I have refrained from giving the particulars for heating by steam and electricity, or the other methods which have been adopted by various workers, as there is no question but that a gas stove or oven, as described, is about the best and handiest for jobbers or amateurs. MODERN JAPANNING AND ENAMELLING STOVES. The modern japanning and enamelling stove consists of a compartment capable of being heated to any desired temperature, say 100° to 400° F., and at the same time, except as regards ventilation, capable of being hermetically sealed so as to prevent access of dust, soot, and dirt of all kinds to mar the beauty and lustre of the object being enamelled or japanned. Such a stove may be heated-- 1. By a direct coal, coke, wood, peat, or gas fire (which surrounds the inner isolated chamber) (Fig. 5). 2. By heated air. 3. By steam or hot-water pipes, coils of which circulate round the interior of the stove or under the floor. Such ovens may be either permanent, that is, built into masonry, or portable. [Illustration: FIG. 5.--Greuzburg's Japanning Oven.] 1. _Stoves heated by direct fire._--These were, of course, the form in which japanning ovens were constructed somewhat after the style of a drying kiln. Fig. 5, Greuzburg's japanning oven heated on the outside by hot gases from furnace. The oven is built into brickwork, and the hot gases circulate in the flues between the brickwork and the oven, and its erection and the arrangement of the heating flues are a bricklayer's job. Coke containing much sulphur is objectionable as a fuel for enamel stoves Mr. Dickson emphasizes this very forcibly. He says: "In the days when stoves were heated by coke furnaces, and the heat distributed by the flues, the principal trouble was the escape of fumes of sulphur which caused dire disaster to all the enamels by entering into their composition and preventing their ever drying, not to speak of hardening. I have known enamels to be in the stoves with heat to 270° for two and three days, and then be soft. The sulphur also caused the enamels to crack in a peculiar manner, much like a crocodile skin, and work so affected could never be made satisfactory, for here again we come back to the first principle, that if the foundation be not good, the superstructure can never be permanent. The enamels, being permeated with sulphur and other products from the coke, could never be made satisfactory, and the only way was to clean it all off. The other principal troubles are the blowing of the work in air bubbles, which is caused mainly by the heat being too suddenly applied to the articles, but these are very small matters to the experienced craftsman." [Illustration: FIG. 6.] 2. _Stoves heated by hot-water pipes._--Let us first of all consider the principle on which these are constructed. In Perkins' apparatus for conveying heat through buildings by the circulation of water in small-bore hot-water pipes an endless tube or pipe is employed, the surface of which is occasionally increased by spiral or other turnings where the heat is to be given off or acquired: the annexed figure may serve to illustrate this principle; it represents a strong wrought-iron tube of about one inch diameter completely filled with water; the spiral A passes through a furnace where it is highly heated, and the water is consequently put into motion in the direction of the arrows; the boiling of the water or formation of steam is prevented by the pressure, whence the necessity of the extreme perfection and strength of the tube. B represents a second coil which is supposed to be in an apartment where the heat is to be given out. C is a screw stopper by which the water may be occasionally replenished. By this form of apparatus the water may be heated to 300° or 400°, or even higher, so as occasionally to singe paper. A larger tube and lower temperature are, however, generally preferable.[1] [Illustration: FIG. 7.--Enamelling Stove--in a Tin-plate Printing Factory--heated by Perkins' Hot-water Pipes.] The principle of Perkins' invention has, during the last eighty years, i.e. since the date of the invention in 1831, been very extensively applied not only for the heating of buildings of every description, but it has also been utilized for numerous industrial purposes which require an atmosphere heated up to 600° F. The principle lends itself specially to the design of apparatus for raising and maintaining heat evenly and uniformly, and also very economically for such purposes as enamelling, japanning, and lacquering. The distinctive feature of this apparatus when applied to moderate temperatures lies in the adoption of a closed system of piping of small bore, a certain portion of which is wound into a coil and placed in a furnace situated in any convenient position outside the drying chamber or hot closet. The circulation is thus hermetically sealed and so proportioned that while a much higher temperature can be attained than is possible with a system of pipes open to the atmosphere, yet a certain and perfectly safe maximum cannot by any possibility be exceeded. The efficiency of the apparatus increases within certain limits in proportion to the pressure employed, which fact explains the exceedingly economical results obtained, while the fact that, owing to the high temperature used, a small-bore pipe can be made more effective than the larger pipes used in any open system, accounts for the lower first cost of the Perkins' apparatus. [Illustration: FIG. 8.--Japanning and Enamelling Oven Heated by Single Hot-water Pipes sealed at both ends with Furnace in Rear.] [Illustration: FIG. 9--Japanning and Enamelling Oven For Bedstead, Ironmongery, Cash-box, and Lamp Factories.] [Illustration: FIG. 10.--Japanning and Enamelling Stove for parts of Sewing Machines.] It will be seen from the various illustrations that the articles to be treated are absolutely isolated from actual contact with the fire or the fire gases and other impurities which must be an objection to all methods of heating by means which are not of a purely mechanical nature. This principle not only recommends itself as scientifically correct and suited to the purpose in view, but is also a very simple and practical one. It affords the means of applying the heat at the point where it is required to do the work without unduly heating parts where heat is unnecessary; it secures absolute uniformity, perfect continuity, and the highest possible fuel economy. [Illustration: FIG. 11.--Japanning and Enamelling Stove for Iron-Bedsteads and Household Ironmongery with Truck on Rails.] [Illustration: FIG. 12--Permanent Japanning and Enamelling Stove for Kitchen Utensils built in Masonry.] The nature of the work to be executed in the different classes and various sizes of stoves vary so greatly and indefinitely that only by careful attention to the special requirements of each case, on the part of the designers and constructors, is it possible to obtain the most satisfactory results. The arrangement of fixing the pipes round the lower walls of the room in this form of stove is somewhat cumbersome, but in a roomy stove this slight drawback is not felt quite so much. However, it seems a good principle to leave every inch of internal space available for the goods to be enamelled or japanned, This principle is carried out to the letter in the other form of stoves described and illustrated in the sequel. The figure shows a section through single chamber japanning and enamelling oven heated by hot-water pipes (steel) closed at both ends and partially filled with water which always remains sealed up therein, and never evaporates until the pipes require to be refilled. This stove may be heated (1) by hot-water pipes (iron), (2) by super-heated water, (3) by steam, but only to 80° C. The different compartments may be heated to uniform or to different temperatures with hot water; the stoke-hole is at the side and thus quite separated from the stove proper. The ovens must be on the ground floor, so that the super-heated steam from the basement may be available. The great drawback to the use of gas for heating japanning and enamelling stoves is the great cost of coal gas. [Illustration: FIG. 13.--Portable Gas Heated Japanning and Enamelling Stove fitted with Shelves, Thermometer, etc.] PIGMENTS SUITABLE FOR JAPANNING WITH NATURAL LACQUER. _White Pigments._--Barium sulphate and bismuth oxychloride. These two are used for the white lacquer or as a body for coloured lacquers. When the lacquer is to be dried at a high temperature barium sulphate is preferable, but when it is dried at an ordinary temperature bismuth oxychloride is better. Since the lacquer is originally of a brown colour the white lacquer is not pure white, but rather greyish or yellowish. Many white pigments, such as zinc oxide, zinc sulphide, calcium carbonate, barium carbonate, calcium sulphate, lead white, etc., turn brown to black, and no white lacquer can be obtained with them. _Red Pigments._--Vermilion and red oxide of iron. These two are used for the red lacquer, but vermilion should be stoved at a low temperature. _Blue Pigment._--Prussian blue. _Yellow Pigments._--Cadmium sulphide, lead chromate and orpiment. _Green Pigment._--Chromium oxide (? Guignet's green). _Black Pigment._--Lamp black. This is one of the pigments for black lacquer, but does not give a brilliant colour, therefore it is better to prepare the black lacquer by adding iron powder or some compound of iron to the lacquer. Various mixed colours are obtained by mixing some of the above-mentioned pigments. Examples of application are as follows:-- (1) _Golden Yellow._--Finished lacquer, 10 parts; gamboge, 1 to 3; solvent, 5. If utensils are lacquered with this thin lacquer and dried for about 2 hours in an air-oven at a temperature of 120° C. a beautiful hard coating of golden colour is obtained. (2) _Black._--Black lacquer, 10 parts; solvent 2 to 4. Utensils lacquered with this lacquer are dried for about an hour at 130° to 140° C. (3) _Red._--Vermilion, 10 parts; finished lacquer, 4; solvent, 2. This lacquer is dried for about an hour at 130° to 140° C. (4) _Khaki or Dirty Yellow._--Barium sulphate, 100 parts; chromic oxide, 3; finished lacquer, 20 to 25; solvent, 15. This lacquer is dried for about half an hour at 160° C. (5) _Green._--Barium sulphate, 100 parts; chromic oxide, 20 to 50; finished lacquer, 40 to 50; solvent, 20. This is dried for about 10 minutes at 160° C. (6) _Yellow._--Barium sulphate, 100 parts; lead chromate, 40; finished lacquer, 40; solvent, 20. This is dried for about 15 minutes at 150° C. Almost all pigments other than the above-mentioned are blackened by contact with lacquer or suspend its drying quality. Several organic lakes can be used for coloured lacquers, that is to say, Indian yellow, thioflavin, and auramine lake for a yellow lacquer; fuchsine, rhodamine, and chloranisidin lake for a red; diamond sky blue, and patent nileblue lake for a blue; acid green, diamond green, brilliant milling green, vert-methyl lake, etc., for a green; methyl violet, acid violet, and magenta lake for a violet; phloxine lake for a pink. These lakes, however, are decomposed more or less on heating and fail to give proper colours when dried at a high temperature. MODERN METHODS OF JAPANNING AND ENAMELLING WITH NATURAL JAPANESE LACQUER. Urushiol, the principal constituent of Japanese lacquer, does not according to the Japanese investigator, Kisaburo Miryama, dry by itself at ordinary temperatures, but can be dried with ease at a temperature above 96° C. In the same way, lacquer that has been heated to a temperature above 70° C. and has entirely lost its drying quality can be easily dried at a high temperature. In this method of japanning the higher the temperature is, the more rapidly does the drying take place; for instance, a thin layer of urushiol, or lacquer, hardens within 5 hours at 100° C., within 30 minutes at 150° C., and within 10 minutes at 180° C. Japanning at a high temperature with natural lacquer does not require the presence of the enzymic nitrogenous matter in the lacquer, and gives a transparent coating which is quite hard and resistant to chemical and mechanical action; in these respects it is distinguished from that dried at an ordinary temperature. During the drying, oxygen is absorbed from the atmosphere and at the same time a partial decomposition takes place. This method of japanning has its application in lacquering metal work, glass, porcelain, earthenware, canvas, papier-mâché, etc.; because the drying is affected in a short time, and the coating thus obtained is much more durable than the same obtained by the ordinary method. For practical purposes it is better to _thin the lacquer with turpentine oil or other solvent_ in order to facilitate the lacquering and lessen the drying time of the lacquer. Since the lacquer-coating turns brown at a high temperature, lacquers of a light colour should be dried at 120° to 150° C.; and even those of a deep colour must not be heated above 180° C. _Most pigments are blackened by lacquer; therefore the varieties of coloured lacquers are very limited._ FOOTNOTES: [1] A question has been raised concerning the safety of Perkins' apparatus, not merely as relates to the danger of explosion, but also respecting that of high temperature; and it has been asserted that the water may be so highly heated in the tubes as to endanger the charring and even inflammation of paper, wood, and other substances in their contact or vicinity: such no doubt might be the case in an apparatus expressly intended for such purposes, but in the apparatus as constructed by Perkins, with adequate dampers and safety valves, and used with common care, no such result can ensue. Paper bound round an iron tube is not affected till the temperature exceeds 400°; from 420° to 444° it becomes brown or slightly singed; sulphur does not inflame below 540°. SECTION V. COLOURS FOR POLISHED BRASS--MISCELLANEOUS. PAINTING ON ZINC OR ON GALVANIZED IRON. Painting on zinc or galvanized iron is facilitated by employing a mordant of 1 quart of chloride of copper, 1 of nitrate of copper, and 1 of sal-ammoniac, dissolved in 64 parts of water. To thin mixture add 1 part of commercial hydrochloric acid. This is brushed over the zinc, and dries a dull-grey colour in from twelve to twenty-four hours, paint adhering perfectly to the surface thus formed. BRONZING COMPOSITIONS. The following are the formulæ for a variety of baths, designed to impart to polished brass various colours. The brass objects are put into boiling solutions composed of different salts, and the intensity of the shade obtained is dependent upon duration of the immersion. With a solution composed of sulphate of copper, 120 grains; hydrochlorate of ammonia, 30 grains; and water 1 quart, greenish shades are obtained. With the following solution, all the shades of brown, from orange-brown to cinnamon, are obtained: chlorate of potash, 150 grains; sulphate of copper, 150 grains; and water, 1 quart. The following solution gives the brass first a rosy tint, and then colours it violet and blue: sulphate of copper, 435 grains; hyposulphite of soda, 300 grains; cream of tartar, 150 grains; and water, 1 pint. Upon adding to this solution ammoniacal sulphate of iron, 300 grains, and hyposulphite of soda, 300 grains, there are obtained, according to the duration of the immersion, yellowish, orange, rosy, and then bluish shades. Upon polarizing the ebullition, the blue tint gives way to yellow, and finally to a pretty grey. Silver, under the same circumstances, becomes very beautifully coloured. After a long ebullition in the following solution, we obtain a yellow-brown shade, and then a remarkable fire-red: chlorate of potash, 75 grains; carbonate of nickel, 30 grains; salt of nickel, 75 grains; and water, 10 oz. The following solution gives a beautiful dark-brown colour: chlorate of potash, 75 grains; salt of nickel, 150 grains; and water, 10 oz. The following gives in the first place, a red, which passes to blue, then to pale lilac, and finally to white: orpiment, 75 grains; crystallized sal-sodæ, 150 grains; and water, 10 oz. The following gives a yellow-brown: salt of nickel, 75 grains; sulphate of copper, 75 grains; chlorate of potash, 75 grains; and water, 10 oz. On mixing the following solutions, sulphur separates, and the brass becomes covered with iridescent crystallizations: (1) cream of tartar, 75 grains; sulphate of copper, 75 grains; and water, 10 oz. (2) Hyposulphite of soda, 225 grains; and water, 5 oz. Upon leaving the brass objects immersed in the following mixture, contained in corked vessels, they at length acquire a very beautiful blue colour: hepar of sulphur, 75 grains; ammonia, 75 grains; and water, 4 oz. A GOLDEN VARNISH FOR METAL. Take 2 oz. of gum sandarach, 1 oz. of litharge of gold, and 4 oz. of clarified linseed oil, which boil in a glazed earthenware vessel till the contents appear of a transparent yellow colour. This will make a good varnish for the final coating for enamelled and japanned goods. CARRIAGE VARNISH. The following is used for the wheels, springs, and carriage parts of coaches and other vehicles: Take of pale African copal 8 lb.; fuse, and add 2-1/2 gallons of clarified linseed oil; boil until very stringy, then add 1/4 lb. each of dry copperas and litharge; boil, and thin with 5-1/2 gallons of turpentine; then mix while hot with the following varnish, and immediately strain the mixture into a covered vessel. Gum anime, 8 lb.; clarified linseed oil, 2-1/2 gallons; 1/4 lb. each of dried sugar of lead and litharge; boil, and thin with 5-1/2 gallons of turpentine; and mix it while hot as above directed. Of course these quantities will only do for big jobs, and as it has to do with metal, it has been thought advisable to include the formula in this handbook. METAL POLISHES. The active constituent of all metal polishes is generally chalk, rouge, or tripoli, because these produce a polish on metallic surfaces. The following recipes give good polishing soaps:-- (1) 20 to 25 lb. liquid soap is intimately mixed with about 80 lb. of Swedish chalk and 1/2 lb. Pompeiian red. (2) 25 lb. liquid coco-nut oil soap is mixed with 2 lb. tripoli, and 1 lb. each alum, tartaric acid, and white lead. (3) 25 lb. liquid coco-nut oil soap is mixed with 5 lb. rouge and 1 lb. ammonium carbonate. (4) 24 lb. coco-nut oil are saponified with 12 lb. soda lye of 38° to 40° B., after which 3 lb. rouge, 3 lb. water, and 32 grammes ammonia are mixed in. Good recipes for polishing pomades are as follows: (1) 5 lb. lard and yellow vaseline is melted and mixed with 1 lb. fine rouge. (2) 2 lb. palm oil and 2 lb. vaseline are melted together, and then 1 lb. rouge, 400 grains tripoli, and 20 grains oxalic acid are stirred in. (3) 4 lb. fatty petroleum and 1 lb. lard are heated and mixed with 1 lb. of rouge. The polishing pomades are generally perfumed with essence of myrbane. Polishing powders are prepared as follows: (1) 4 lb. magnesium carbonate, 4 lb. chalk, and 7 lb. rouge are intimately mixed. (2) 4 lb. magnesium carbonate are mixed with 150 grains fine rouge. An excellent and harmless polishing water is prepared by shaking together 250 grains floated chalk, 1 lb. alcohol, and 20 grains ammonia. Gilded articles are most readily cleansed with a solution of 5 grains borax in 100 parts water, by means of a sponge or soft brush. The articles are then washed in pure water, and dried with a soft linen rag. Silverware is cleansed by rubbing with a solution of sodium hyposulphite. BLACK PAINTS. Carbon, in one form or another, is the base of all black pigments. By far the most common of these, as used in structural plants, is graphite. Other black pigments are lamp-black (including carbon black) and bone-black, the former being produced in many grades, varying in price from twopence to half a crown per pound. Bone-black, which is refuse from the sugar-house black, varies in the percentage of carbon contained, which is usually about 10 or 12 per cent, the remainder being the mineral matter originally present in the bone, and containing 3 or 4 per cent of carbonate, whilst most of the remainder is phosphate of lime. Lamp-black is an absolutely impalpable powder, which having a small amount of greasy matter in it, greatly retards the drying of the oil with which it may be mixed. For this reason it is not used by itself, but is added in small quantity to other paints, which it affects by changing their colour, and probably their durability. For example, it is a common practice to add it to red lead, in order to tone down its brilliant colour, and also to correct the tendency it has to turn white, due to the conversion of the red oxide of lead into the carbonate. BLACK STAIN FOR IRON. For colouring iron and steel a dead black of superior appearance and permanency, the following is a good formula: 1 part bismuth chloride, 2 parts mercury bi-chloride, 1 part copper chloride, 6 parts hydrochloric acid, 5 parts alcohol, and 50 parts lamp-black, these being all well mixed. To use this preparation successfully--the article to be blacked or bronzed being first made clean and free from grease--it is applied with a swab or brush, or, better still, the object may be dipped into it; the liquid is allowed to dry on the metal, and the latter is then placed in boiling water, the temperature being maintained for half an hour. If, after this, the colour is not so dark as is desired, the operation has simply to be repeated, and the result will be found satisfactory. After obtaining the desired degree of colour, the latter is fixed, as well as much improved generally, by placing for a few minutes in a bath of boiling oil, or by coating the surface with oil, and heating the object till the oil is completely driven off The intense black obtained by this method is admirable. Another black coating for ironwork, which is really a lacquer, is obtained by melting ozokerite, which becomes a brown resinous mass, with a melting-point at 140° F. The melted mass is then further heated to 212° F., the boiling-point of water. The objects to be lacquered are scoured clean by rubbing with dry sand, and are dipped in the melted mass. They are then allowed to drip, and the ozokerite is ignited by the objects being held over a fire. After the ozokerite has burned away, the flame is extinguished, and the iron acquires a firmly adhering black coating, which resists atmospheric influences, as well as acids and alkalies. If the black iron vessels are to contain alkaline liquids, the above operation is repeated. A good cheap stock black paint or varnish for ironwork is prepared, as follows: Clear (solid) wood tar, 10 lb.; lamp black or mineral black, 1-1/4 lb.; oil of turpentine, 5-1/2 quarts. The tar is first heated in a large iron pot to boiling-point, or nearly so, and the heat is continued for about 4 hours. The pot is then removed from the fire out of doors, and while still warm, and not hot, the turpentine, mixed with the black, is stirred in. If the varnish is too thick to dry quickly, add more turpentine. Benzine can be used instead of turpentine, but the results are not so good. Asphaltum is preferable to the cheap tar. To make another good black varnish for ironwork, take 8 lb. of asphaltum and fuse it in an iron kettle, then add 2 gallons of boiled linseed oil, 1 lb. of litharge, 1/2 lb. of sulphate of zinc (add these slowly, or the mixture will boil over), and boil them for about 3 hours. Then, add 1-1/2 lb. of dark gum amber, and boil for 2 hours longer, or until the mass will become quite thick when cool. After this it should be thinned with turpentine to the proper consistency. VARNISHES FOR IRONWORK. A reliable authority gives the following as a very good recipe for ironwork varnish. Take 2 lb. of tar oil, 1/2 lb. of pounded resin, and 1/2 lb. of asphaltum, and dissolve together, and then mix while hot in an iron kettle, taking all care to prevent the flames getting into contact with the mixture. When cold the varnish is ready for application to outdoor ironwork. Another recipe is to take 3 lb. of powdered resin, place it in a tin or iron vessel, and add thereto 2-1/2 pints of spirits of turpentine, which well shake, and then let it stand for a day or two, giving it an occasional shake. Then add to it 5 quarts of boiled oil, shake it thoroughly well all together, afterwards letting it stand in a warm room till it gets clear. The clear portion can then be drawn off and used, or reduced with spirits of turpentine till of the requisite consistency. For making a varnish suitable for iron patterns, take sufficient oil of turpentine for the purpose of the job in hand, and drop into it, drop by drop, some strong commercial oil of vitriol, when the acid will cause a dark syrupy precipitate in the oil of turpentine, and continue to add the drops of vitriol till the precipitate ceases to act, after which pour off the liquid and wash the syrupy mass with water, when it will be ready for use. When the iron pattern is to be varnished, it must be heated to a gentle degree, the syrupy product applied, and then the article allowed to dry. A fine black varnish suitable for the covering of broken places in sewing machines and similar articles, where the japanned surface has become injured or scratched, can be made by taking some fine lamp-black or ivory-black, and thoroughly mixing it with copal varnish. The black must be in a very fine powder, and to mix the more readily it should be made into a pasty mass with turpentine. For the ordinary repairing shop this will be found very handy. The following is a simple way for tarring sheet-iron pipes to prevent rusting. The sections as made should be coated with coal tar, and then filled with light wood shavings, and the latter set alight. The effect of this treatment will be to render the iron practically proof against rust for an indefinite period, rendering future painting unnecessary. It is important, of course, that the iron should not be made too hot, or kept hot for too long a time, lest the tar should be burnt off. The following is a varnish for iron and steel given by a recognized authority: 5 parts of camphor and elemi, 15 parts of sandarach, and 10 parts of clear grains of mastic, are dissolved in the requisite quantity of alcohol, and applied cold. Another good black enamel for small articles can be made by mixing 1 lb. of asphaltum with 1 lb. of resin in 4 lb. of tar oil, well heating the whole in an iron vessel before applying. A good brown japan can be prepared by separately heating equal quantities of amber and asphaltum, and adding to each one-half the quantity by weight of boiled linseed oil. Both compounds are then mixed together. Copal resin may be substituted for the amber, but it is not so durable. Oil varnish made from amber is highly elastic. If it is used to protect tin-plate printing, when the plates after stoving have been subsequently rolled so as to distort the letters, the varnish has in no way suffered, and its surface remains unbroken. A bronzing composition for coating iron consists of 120 parts mercury, 10 parts tin, 20 parts green vitriol, 120 parts water, and 15 parts hydrochloric acid of 1.2 specific gravity. SECTION VI. PROCESSES FOR TIN-PLATING. In these days of making everything look what it is not, perhaps the best and cheapest substitute for silver as a white coating for table ware, culinary vessels, and the many articles requiring such a coating, is pure tin. It does not compare favourably with silver in point of hardness or wearing qualities, but it costs very much less than silver, is readily applied, and can be easily kept clean and bright. In tinning hollow ware on the inside the metal article is first thoroughly cleansed by pickling it in dilute muriatic or sulphuric acid and then scouring it with fine sand. It is then heated over a fire to about the melting-point of tin, sprinkled with powdered resin, and partly filled with melted pure grain tin covered with resin to prevent its oxidation. The vessel is then quickly turned and rolled about in every direction, so as to bring every part of the surface to be covered in contact with the molten metal. The greater part of the tin is then thrown out and the surface rubbed over with a brush of tow to equalize the coating; and if not satisfactory the operation must be repeated. The vessels usually tinned in this manner are of copper and brass, but with a little care in cleaning and manipulating, iron can also be satisfactorily tinned by this means. The vessels to be tinned must always be sufficiently hot to keep the metal contained in them thoroughly fused. This is covering by contact with melted tin. The amalgam process is not so much used as it was formerly. It consists in applying to the clean and dry metallic surface a film of a pasty amalgam of tin with mercury, and then exposing the surface to heat, which volatilizes the latter, leaving the tin adhering to the metal. The immersion process is the best adapted to coating articles of brass or copper. When immersed in a hot solution of tin properly prepared the metal is precipitated upon their surfaces. One of the best solutions for this purpose is the following:-- Ammonia alum 17-1/4 oz. Boiling 12-1/2 lb. Protochloride of tin 1 oz. The articles to be tinned must be first thoroughly cleansed, and then kept in the hot solution until properly whitened. A better result will be obtained by using the following bath, and placing the pieces in contact with a strip of clean zinc, also immersed:-- Bitartrate of potassium 14 oz. Soft water 24 " Protochloride of tin 1 " It should be boiled for a few minutes before using. The following is one of the best solutions for plating with tin by the battery process:-- Potassium pyrophosphate 12 oz. Protochloride of tin 4-1/2 " Water 20 " The anode or feeding-plate used in this bath consists of pure Banca tin. This plate is joined to the positive (copper or carbon) pole of the battery, while the work is suspended from a wire connected with the negative (zinc) pole. A moderately strong battery is required, and the work is finished by scratch-brushing. In Weigler's process a bath is prepared by passing washed chlorine gas into a concentrated aqueous solution of stannous chloride to saturation, and expelling excess of gas by warming the solution, which is then diluted with about ten volumes of water, and filtered, if necessary. The articles to be plated are pickled in dilute sulphuric acid, and polished with fine sand and a scratch-brush, rinsed in water, loosely wound round with zinc wire or tape, and immersed in the bath for ten or fifteen minutes at ordinary temperatures. The coating is finished with the scratch-brush and whiting. By this process cast-or wrought-iron, steel, copper, brass, and lead can be tinned without a separate battery. The only disadvantage of the process is that the bath soon becomes clogged up with zinc chloride, and the tin salt must be frequently removed. In Hern's process a bath composed of-- Tartaric acid 2 oz. Water 100 " Soda 3 " Protochloride of tin 3 " is employed instead of the preceding. It requires a somewhat longer exposure to properly tin articles in this than in Weigler's bath. Either of these baths may be used with a separate battery. SECTION VII. GALVANIZING. Galvanizing, as a protecting surface for large articles, such as enter into the construction of bridges, roofs, and shipwork, has not quite reached the point of appreciation that possibly the near future may award to it. Certain fallacies existed for a long time as to the relative merits of the dry or molten and the wet or electrolytical methods of galvanizing. The latter was found to be costly and slow, and the results obtained were erratic and not satisfactory, and soon gave place to the dry or molten bath process, as in practice at the present day; but the difficulty of management in connexion with large baths of molten material, and the deterioration of the bath, and other mechanical causes, limit the process to articles of comparatively small size and weight. The electro deposition of zinc has been subject to many patents, and the efforts to introduce it have been lamentable in both a mechanical and financial sense. Most authorities recommend a current density of 18 or 20 ampères per square foot of cathode surface, and aqueous solutions of zinc sulphate, acetate or chloride, ammonia, chloride or tartrate, as being the most suitable for deposition. Electrolytes made by adding caustic potash or soda to a suitable zinc salt have been found to be unworkable in practice on account of the formation of an insoluble zinc oxide on the surface of the anode and the resultant increased electrical resistance; the electrolytes are also constantly getting out of order, as more metal is taken out of the solution than could possibly be dissolved from the anodes by the chemicals set free on account of this insoluble scale or furring up of the anodes, which sometimes reaches one-eighth of an inch in thickness. To all intents and purposes the deposits obtained from acid solutions under favourable circumstances are fairly adhesive when great care has been exercised to thoroughly scale and clean the surface to be coated, which is found to be the principal difficulty in the application of any electro-chemical process for copper, lead, or tin, as well as for zinc, and that renders even the application of paint or other brush compounds to futile unless honestly complied with. Unfortunately these acid zinc coatings are of a transitory nature, Their durability being incomparable with hot galvanizing, as the deposit is porous and retains some of the acid salts, which cause a wasting of the zinc, and consequently the rusting of the iron or steel. Castings coated with acid zinc rust comparatively quickly, even when the porosity has been reduced by oxidation, aggravated no doubt by some of the corroding agents--sal-ammoniac, for instance--being forced into the pores of the metal. Other matters of serious moment in the electro-zincing process, apart from the slowness of the operation, were the uncertain nature, thickness, and extent of the coating on articles of irregular shape, and the formation of loose, dark-coloured patches on the work; the unhealthy and non-metallic look and want of brilliancy and the lustre prevented engineers and the trade from accepting the process or its results, except for the commoner articles of use. To obviate any tendency of the paint to peel off from the zinc surface, as it generally manifests a disposition to do, it is recommended to coat all the zinc surfaces, previous to painting them, with the following compound: 1 part chloride of copper, 1 part nitrate of copper, 1 part sal-ammoniac, dissolved in 61 parts of water, and then add 1 part commercial hydrochloric acid. When the zinc is brushed over with this mixture it oxidizes the surface, turns black, and dries in from twelve to twenty-four hours, and may then be painted over without any danger of peeling. Another and more quickly applied coating consists of, bi-chloride of platinum, 1 part dissolved in 10 parts of distilled water, and applied either by a brush or sponge. It oxidizes at once, turns black, and resists the weak acids, rain, and the elements generally. Zinc surfaces, after a brief exposure to the air, become coated with a thin film of oxide--insoluble in water--which adheres tenaciously, forming a protective coating to the underlying zinc. So long as the zinc surface remains intact, the underlying metal is protected from corrosive action, but a mechanical or other injury to the zinc coating that exposes the metal beneath, in the presence of moisture causes a very rapid corrosion to be started, the galvanic action being changed from the zinc positive to zinc negative, and the iron, as the positive element in the circuit, is corroded instead of the zinc. When galvanized iron is immersed in a corrosive liquid, the zinc is attacked in preference to the iron, provided both the exposed parts of the iron and the protected parts are immersed in the liquid. The zinc has not the same protective quality when the liquid is sprinkled over the surface and remains in isolated drops. Sea air, being charged with saline matters, is very destructive to galvanized surfaces, forming a soluble chloride by its action. As zinc is one of the metals most readily attacked by acids, ordinary galvanized iron is not suitable for positions where it is to be much exposed to an atmosphere charged with acids sent into the air by some manufactories, or to the sulphuric acid fumes found in the products of combustion of rolling mills, iron, glass, and gas works, etc., and yet we see engineers of note covering-in important buildings with corrugated and other sheets of iron, and using galvanized iron tie rods, angles, and other constructive shapes in blind confidence of the protective power of the zinc coating; also in supreme indifference as to the future consequences and catastrophes that arise from their unexpected failure. The comparative inertia of lead to the chemical action of many acids has led to the contention that it should form as good, if not a better, protection of iron than zinc, but in practice it is found to be deficient as a protective coating against corrosion. A piece of lead-coated iron placed in water will show decided evidences of corrosion in twenty-four hours. This is to be attributed to the porous nature of the coating, whether it is applied by the hot or wet (acid) process. The lead does not bond to the plate as well as either of the other metals--zinc, tin, copper, or any alloys of them. The following table gives the increase in weight of different articles due to hot galvanizing:-- +--------------------------+--------------------------+-------------+ | Description of | Weight of Zinc | Percentage | | Article | per Square foot | of Increase | | | | of Weight | +--------------------------+--------------------------+-------------+ | Thin sheet-iron | 1.196 oz. | 18.2 | | 5/16-in. plates | 1.76 " | 2.0 | | 4-in. cut nails | 2.19 " | 6.72 | | 7/8-in. die bolt and nut | approximately 1.206 oz. | 1.00 | +--------------------------+--------------------------+-------------+ Tin is often added to the hot bath for the purpose of obtaining a smoother surface and larger facets, but it is found to shorten the life of the protective coating very considerably. A portion of a zinc coating applied by the hot process was found to be very brittle, breaking when attempts were made to bend it; the average thickness of the coating was .015 inch. An analysis gave the following result: tin, 2.20; iron, 3.78; arsenic, a trace; zinc (by difference), 94.02. A small quantity of iron is dissolved from all the articles placed in the molten zinc bath, and a dross is formed amounting in many cases to 25 per cent of the whole amount of zinc used. The zinc-iron alloy is very brittle, and contains by analysis 6 per cent of iron, and is used to cast small art ornaments from. A hot galvanizing plant, having a bath capacity of 10 feet by 4 feet by 4-1/2 feet outside dimensions, and about 1 inch in thickness, will hold 28 tons of zinc. With equal amounts of zinc per unit of area, the zinc coating put on by the cold process is more resistant to the corroding action of a saturated solution of copper sulphate than is the case with steel coated by the ordinary hot galvanizing process; or, to put it in another form, articles coated by the cold process should have an equally long life under the same conditions of exposure that hot galvanized articles are exposed to, and with less zinc than would be necessary in the ordinary hot process. The hardness of a zinc surface is a matter of some importance. With this object in view aluminium has been added from a separate crucible to the molten zinc at the moment of dipping the article to be zinced, so as to form a compound surface of zinco-aluminium, and to reduce the ashes formed from the protective coverings of sal-ammoniac, fat, glycerine, etc. The addition of the aluminium also reduces the thickness of the coating applied. Cold and hot galvanized plates appear to stand abrasion equally well. Both pickling and hot galvanizing reduce the strength, distort and render brittle iron and steel wires of small sections. THE END. INDEX. A Amalgam process in tin-plating, 59. Appliances and apparatus used in japanning and enamelling, 29. B Battery process in tin-plating, 59. Black grounds, 11. ---- japan grounds on metal, common, 12. ---- paints, 52. ---- pigment, 46. ---- stain for iron, 53. ---- varnish for sewing machines, 56. Blue japan grounds, 9. ---- pigment, 46. Brass, polished, colours for, 49-57. Brick ovens, 33. Bright pale yellow grounds, 10. Bronzing composition, 49. Brown japan, 57. Bunsen burner, 33. C Carriage varnish, 51. Colours for polished brass, 49. Common black japan grounds on metal, 12. Composition for bronzing, 49. Cream enamel, 8. E Enamelling and japanning stoves, 29-46. ---- ---- ---- ---- heated by direct fire, 34. ---- ---- ---- ---- heated by hot-water pipes, 36. ---- or japanning metals, 20-28. ---- old work, 27. F First stage in the japanning of wood, 5. ---- ---- in the japanning of leather, without a priming, 5. G Galvanized iron, painting on, 49. Galvanizing, 61-66. Golden varnish for metal, 51. Green japan grounds, 10. ---- pigment, 46. Ground, red japan, 10. ---- scarlet japan, 9. ---- tortoise-shell, 12. Grounds, black, 11. ---- black japan, 12. ---- blue japan, 9. ---- bright pale yellow, 10. ---- green japan, 10. ---- japan, 6-19. ---- orange-coloured, 11. ---- purple, 11. ---- white japan, 7 H Heating stoves by direct fire, 34. ---- ---- by hot-water pipes, 36. Hern's process in tin-plating, 60. I Immersion process in tin-plating, 59. Iron, black stain for, 53. ---- galvanized, painting on, 49. Ironwork, varnishes for, 55. J Japan, brown, 57. ---- ground, red, 10. ---- ---- scarlet, 9. ---- ---- grounds, 6-19. ---- ---- black, 12. ---- ---- blue, 9. ---- ---- green, 10. ---- ---- white, 7. ---- work, painting, 13. ---- ---- varnishing, 17. Japanese gold size, 14. Japanese lacquer, 47. Japanning and enamelling stoves, 34. ---- ---- ---- ---- heated by direct fire, 34. ---- ---- ---- ---- heated by hot-water pipes, 36. ---- leather without a priming, first stage, 5. ---- or enamelling metals, 20-28. ---- tin, 25. ---- wood, first stage, 5. L Lacquer, Japanese, 47. M Metal, golden varnish for, 51. ---- polishes, 51. Metals, japanning or enamelling, 20-28. Modern japanning and enamelling stoves, 34. N Natural Japanese lacquer, 47. ---- lacquer, 45. O Oil vehicle, 14. Old work, enamelling, 27. Orange-coloured grounds, 11. P Painting japan work, 13. ---- on galvanized iron, 49. ---- ---- zinc, 49. Paints, black, 52. Pigments suitable for japanning with natural lacquer, 45. ---- black, 46. ---- blue, 46. ---- green, 46. ---- red, 46. ---- white, 45. ---- yellow, 46. Polished brass, colours for, 49. Preparing the surface to be japanned, 4. Priming the surface to be japanned, 4. Processes for tin-plating, 58. Purple grounds, 11. R Red japan ground, 10. ---- pigments, 46. S Scarlet japan ground, 9. Sewing machines, black varnish for, 56. Shellac varnish, 6. Stoves, modern japanning and enamelling, 34. Stove, the enamelling and japanning, 29-45. Surface to be japanned, priming or preparing the, 4. T Tin, japanning, 25. Tin-plating, colours for, 58. Tin-plating, amalgam process, 59. ---- battery process, 59. ---- Hern's process, 60. ---- immersion process, 59. ---- Weigler's process, 60. Tortoise-shell ground, 12. U Urushiol, 47. V Varnish, carriage, 51, ---- for iron and steel, 57. ---- for metal, golden, 51. ---- shellac, 6. Varnishes for iron work, 55. Varnishing japan work, 17. W Weigler's process of tin-plating, 60. White japan grounds, 7. ---- pigments, 45. Wood, first stage in the japanning of, 5. Y Yellow grounds, bright pale, 10. ---- pigments, 46. Z Zinc, painting on, 49. ABERDEEN: THE UNIVERSITY PRESS * * * * * ENAMELS AND ENAMELLING An Introduction to the Preparation and Application of all kinds of Enamels for Technical and Artistic Purposes. TRANSLATED FROM THE GERMAN OF PAUL RANDAU. _Second and Enlarged Edition._ _Demy 8vo._ _194 Pages._ Price 10s. 6d. net. (Post Free, 10s. 10d. Home; 11s. Abroad.) Published by SCOTT, GREENWOOD & SON, 8 BROADWAY, LUDGATE, LONDON, E.C. * * * * * THE MANUFACTURE OF VARNISHES. BY _J.G. McINTOSH._ Based on and including the work of ACH. LIVACHE. IN THREE VOLUMES. VOLUME I.--OIL CRUSHING, REFINING AND BOILING, THE MANUFACTURE OF LINOLEUM, PRINTING AND LITHOGRAPHIC INKS, AND INDIA-RUBBER SUBSTITUTES. Demy 8vo. 150 pp. 29 Illustrations. Price 75. 6d. net. (Post free, 7s. 10d. home; 8s. abroad.) VOLUME II.--VARNISH MATERIALS AND OIL-VARNISH MAKING. Demy 8vo. 70 Illustrations. 220 pp. Price 10s. 6d. net. (Post free, 10s. 10d. home; 11s. 3d. abroad.) VOLUME III.--SPIRIT VARNISHES AND SPIRIT VARNISH MATERIALS. Demy 8vo. 64 Illustrations. 464 pp. Price 12s. 6d. net. (Post free, 13s. home; 13s. 6d. abroad.) Send for Catalogue giving List of Contents of above works from SCOTT, GREENWOOD & SON, 8 BROADWAY, LUDGATE, LONDON, E.C. * * * * * For the latest recipes, etc., on Japanning you should read Oil & Colour Trades Journal. The Weekly Organ of the OIL, PAINT, VARNISH, SOAP, GLUE, DRYSALTERY, AND ALLIED TRADES. The Annual Subscription FOR 52 WEEKLY ISSUES, POST FREE, AND A COPY OF THE ANNUAL DIARY AND TRADE DIRECTORY, CARRIAGE PAID, IS 10s. TO ANY PART OF THE WORLD. A Specimen Copy WILL BE SENT TO ANYONE SENDING THEIR NAME AND ADDRESS TO THE OIL AND COLOUR TRADES JOURNAL OFFICES, 8 BROADWAY, LUDGATE, LONDON, E.C. 
21224	----	Leaves Turning Yellow, 2. Summer or Sun-brand, 3. Cones Dropping Off, 4. Honey Dew, 5. Damage from Wind, Hail and Rain; Vegetable Enemies of the Hop: Animal Enemies of the Hop.--Beneficial Insects on Hops. =PART III., CULTIVATION.= The Requirements of the Hop in Respect of Climate, Soil and Situation: Climate; Soil; Situation,--Selection of Variety and Cuttings.--Planting a Hop Garden: Drainage; Preparing the Ground; Marking-out for Planting; Planting; Cultivation and Cropping of the Hop Garden in the First Year.--Work to be Performed Annually in the Hop Garden: Working the Ground; Cutting; The Non-cutting System; The Proper Performance of the Operation of Cutting: I. Method of Cutting: Close Cutting, Ordinary Cutting, The Long Cut, The Topping Cut; II. Proper Season for Cutting: Autumn Cutting, Spring Cutting: Manuring; Training the Hop Plant: Poled Gardens, Frame Training; Principal Types of Frames: Pruning, Cropping, Topping, and Leaf Stripping the Hop Plant; Picking, Drying and Bagging.--Principal and Subsidiary Utilisation of Hops and Hop Gardens.--Life of a Hop Garden; Subsequent Cropping.--Cost of Production, Yield and Selling Prices. PART IV.--Preservation and Storage.--Physical and Chemical Structure of the Hop Cone.--Judging the Value of Hops. PART V.--Statistics of Production.--The Hop Trade.--Index. =Press Opinions.= "The subject is dealt with fully in every little detail; consequently, even the veriest tyro can take away some useful information from its pages."--_Irish Farming World._ "Farmers are but little given to reading; but nowadays brewers have to study their trade and keep abreast of its every aspect, and as far as regards our trade, to them this book especially appeals, and will be especially useful."--_Licensed Victuallers' Gazette._ "Like an oasis in the desert comes a volume upon the above subject, by the Professor at the Higher Agricultural College, Tetschen-Liebwerd, Germany, who has been fortunate enough to obtain an excellent translator from the German in the person of Mr. Charles Salter. The paucity of works upon the history and cultivation of hops is surprising considering the scope it gives for an interesting and useful work."--_Hereford Times._ "We can safely say that this book deals more comprehensively and thoroughly with the subject of hops than any work previously published in this country.... No one interested in the hop industry can fail to extract a large amount of information from Professor Gross's pages, which, although primarily intended for Continental readers, yet bear very closely on what may be termed the cosmopolitan aspects of the science of hop production."--_South Eastern Gazette._ "This is, in our opinion, the most scholarly and exhaustive treatise on the subject of hops, their culture and preservation, etc., that has been published, and to the hop grower especially will its information and recommendations prove valuable. Brewers, too, will find the chapter devoted to 'Judging the Value of Hops' full of useful hints, while the whole scope and tenor of the book bear testimony to the studious and careful manner in which its contents have been elaborated."--_Brewers' Journal._ "Considering the extent to which this country draws its hop supplies from abroad, this translation of Professor Gross's volume will prove an interesting and instructive addition to the library of any brewer or brewers' chemist, the more so as the work of translation has been admirably carried out in simple and vigorous English.... The volume is one of a valuable series of special technical works for trades and professions the publishers are issuing, and is the first so far dealing with the brewing industry."--_Burton Mail._ "A work upon the above subject must be welcomed if for no other reason than the dearth of books dealing with so interesting a theme, but fortunately apart from this the book will afford excellent reading to all interested in hops and their culture. Professor Gross takes one over the whole field, by commencing with the earliest history of the plant--so far back as the days of ancient Greece--and from both practical, theoretical and scientific standpoints, deals with the cultivation, classification and formation of the hop.... In speaking of the production of new varieties sound information is given, and should be of value to those who are always in search of improvements."--_Hereford Journal._ "This work is, without doubt, the most thorough and extensive compilation on hops ever yet offered to the public, and for this reason should be warmly welcomed and appreciated by men interested in the subject. Although primarily written for those engaged in the industry abroad, and mainly Continental in theory and practice, it nevertheless appeals to those connected with the hop growing and brewing business in England, not only by way of a comparison, but also as an instruction. The volume is at once practical and scientific, is well got up, and teems with illustrations and statistics. 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21592	----	THE ART OF MAKING WHISKEY, SO AS TO OBTAIN A BETTER, PURER, CHEAPER AND GREATER QUANTITY OF SPIRIT, FROM A GIVEN QUANTITY OF GRAIN. ALSO, THE ART OF CONVERTING IT INTO GIN. AFTER THE PROCESS OF THE HOLLAND DISTILLERS, _WITHOUT ANY AUGMENTATION OF PRICE._ By ANTHONY BOUCHERIE, OF LEXINGTON, KY. TRANSLATED FROM THE FRENCH BY C. M******* LEXINGTON, KY. PRINTED BY WORSLEY & SMITH. 1819 [Transcriber's Note: This edition is from Microfiche. All copies that I've found are marked "Photographed from an imperfect copy." Printer errors have been left as is, but noted. We cannot account for the accuracy in some of the numbers, where the original was exceptionally difficult to read. Where applicable, any changes are noted with a [TR]. Any other inconsistencies were left as in the original. A Table of Contents has been included in the HTML version.] UNITED STATES OF AMERICA, _District of Kentucky, to wit:_ Be it remembered, That on the 10th day of December, in the year of our Lord, 1818, and the forty-third year of the Independence of the United States of America, came ANTHONY BOUCHERIE, of the said district, and deposited in this office, a copy of the title of a book, the right whereof he claims as author and proprietor, in the words and figures following, viz: _"The Art of making Whiskey, so as to obtain a better, purer, cheaper and greater quantity of Spirit from a given quantity of Grain: Also, the art of converting it into Gin, after the process of the Holland Distillers, without any augmentation in the price.--By Anthony Boucherie:"_ In conformity to the act of Congress of the United States, entitled "An act for the encouragement of learning, by securing the copies of maps, charts and books to the authors ann [TR: and] proprietors of such copies during the times therein mentioned." And also to an act, entitled "An act supplementary to an act, entitled an act for the encouragement of learning, by securing the copies of maps, charts and books to the authors and proprietors of such copies, during the times therein mentioned, and extending the benefits thereof to the arts of designing and etching historical and other prints." JOHN H. HANNA, _Clerk of the District of Kentucky._ [Library stamp: IMPERFECT IN ORIGINAL] TO THE HONOURABLE LEGISLATURE OF THE STATE OF KENTUCKY. GENTLEMEN OF THE SENATE, AND OF THE HOUSE OF REPRESENTATIVES, _An immense and most fertile country, a republic where every individual enjoys the most unbounded freedom; such are the advantages which characterise the United States of America, and render them the asylum of the oppressed Europeans. I was one of the number, and as early as January, 1808, congress enacted a law dispensing me with the usual term of two years residence, for obtaining a patent._ _It is the duty of every citizen to contribute to the progress of useful knowledge, for the benefit and prosperity of his native or adopted country. It is under that point of view that I now publish_ The Art of Making Whiskey, so as to obtain a greater quantity of Spirit from a given quantity of Grain; the spirit thus obtained being purer and cheaper. Also, the Art of converting it into Gin, according to the process of the Holland Distillers, without making it dearer. [TR: This next paragraph is incomplete] _Give me leave, gentlemen, to publish this little w--[TR: work?] under the patronage of the enlightened Legisl--[TR: Legislature?] of the state which I have chosen for my--[TR: residence?] is undoubtedly of a general utility fo--_ _but more particularly an agricultural state, such as this, where every thing that contributes to the success of agriculture, adds to the welfare of the commonwealth. It is therefore to promote that desirable end, that I hereby renounce all the privileges granted me eight years ago, for the distiller's apparatus, of which I give here a description. I invite all distillers to use it the more confidently, as a long experience has proved to me its utility. In describing the art of converting Whiskey into Gin, according to the process of the Holland Distillers, I flatter myself, that I give a greater value to a national production usually neglected througout [TR: throughout] the continent, and which will be the principle of a considerable produce. Henceforth the Gin of the United States will be an important article of exportation for their outward trade, as well as for home consumption._ _Receive, gentlemen, the Assurances of my Profound Respect, A. BOUCHERIE._ PREFACE. The most usual drink in the United States, is whiskey; other spirituous liquors, such as peach and apple brandy, are only secondary, and from their high price and their scarcity, they are not sufficient for the wants of an already immense and increasing population. As to wine, in spite of all the efforts and repeated trials made to propagate the grape-vine, there is as yet no hopes, that it may in time become the principal drink of the Americans. To turn our enquiries towards the means of bringing the art of making whiskey to greater perfection, is therefore, to contribute to the welfare of the United States, and even to the health of the Americans, and to the prosperity of the distiller, as I will prove in the sequel. The arts and sciences have made great progress; my aim is to diffuse new light on every thing that relates to the formation of spirituous liquors that may be obtained from grains. Most arts and trades are practised without principles, perhaps from the want of the means of information. For the advantage of the distillers of whiskey, I will collect and offer them the means of obtaining from a given quantity of grain, the greatest possible quantity of spirit, purer and cheaper than by the usual methods. I shall then proceed to indicate the methods of converting whiskey into gin, according to the process of the Holland Distillers, without heightening its price. If the principles hereafter developed are followed, the trade of distiller will acquire great advantages, that will spread their influence on agriculture, and consequently on commerce in general. THE ART OF MAKING WHISKEY, &c. CHAPTER I. OF SPIRITUOUS LIQUORS, OR SPIRITS. Spirituous liquors are the produce of vinous ones, obtained by the distillation of these last. The art of making wine is of the remotest antiquity, since it is attributed to Noah; but that of distilling it, so as to extract its most spirituous part, dates only from the year 1300. Arnand de Villeneuve was the inventor of it, and the produce of his Still appeared so marvellous, that it was named Aqua-Vitæ, or _Water of Life_, and has ever since continued under that denomination in France; Voltaire and reason say that it might, with far more propriety, be called _Aqua-Mortis_, or Water of Death. This liquor, called in English, _Brandy_, received from the learned the name of _Spirit of Wine_; time improved the art of making it still stronger by concentration, and in that state it is called _Alcohol_. All spirit is the distilled result of a wine, either of grapes, other fruits, or grains; it is therefore necessary to have either wine, or any vinous liquor, in order to obtain spirits. CHAPTER II. OF THE FORMATION OF VINOUS LIQUORS WITH GRAINS, IN ORDER TO MAKE SPIRITS. The art of extracting wine from the juice of the grape, not being the object of this book, I shall confine myself to what is necessary and useful to the distillers of whiskey; it is therefore of the vinous liquor extracted from grains, that I am going to speak. The formation of that kind of liquor is founded upon a faculty peculiar to grains, which the learned chymist, Fourcroy, has called _saccharine fermentation_. Sugar itself does not exist in gramineous substances; they only contain its elements, or first principles, which produce it. The saccharine fermentation converts those elements into sugar, or at least into a saccharine matter; and when this is developed, it yields the eminent principle of fermentation, without which there exists no wine, and consequently no spirit. Grains yield two kinds of vinous liquors, of which the distiller makes spirit, and the brewer a sort of wine, called _beer_. From a comparison of the processes employed to obtain these two results, it will be found that the brewer's art has attained a higher degree of perfection than that of the distiller. They both have for their object to obtain a vinous liquor; but that of the brewer is, in reality, a sort of wine to which he gives, at pleasure, different degrees of strength; while that of the distiller is scarcely vinous, and cannot be made richer. I will give a succinct exposition of their two processes in order that they may be compared. OF THE ART OF BREWING. The art of brewing consists: 1st. In the sprouting of a proportion of grain, chiefly barley. This operation converts into a saccharine matter, the elements of that same substance already existing in grains. 2dly. In preparing the _wort_. For that operation, the grain, having been previously ground, is put into a vat, which is half filled up with water; the rest is filled up at three different times with hot water--the first at 100°, the second at 150°, and the third at 212°, which is boiling water. The mixture is strongly stirred each time that it is immersed. By this infusion, the water lays hold of the sweet principles contained in the grain. 3dly. The wort thus prepared, the liquor is filtrated, in order to separate it from the grain, and then boiled until reduced to one half, in order to concentrate it to the degree of strength desired. In that state, 40 gallons of wort contain the saccharine principles of 200 wt. of grain. 4thly. The wort, thus concentrated, is drawn off in barrels, which are kept in a temperature of 80° or 85°. The yeast is thrown into it to establish the fermentation, and in a short time beer is made, more or less strong, according to the degree of concentration, and more or less bitter, according to the greater or lesser proportion of hops put into it. Such are, in a concise view, the proceedings of the brewer. Let us proceed to those of the distiller of whiskey. OF THE DISTILLER OF WHISKEY. Whiskey is made either with rye, barley, or Indian corn. One, or all those kinds of grains is used, as they are more or less abundant in the country. I do not know how far they are mixed in Kentucky; but Indian corn is here in general the basis of whiskey, and more often employed alone. I have ascertained, in the different distilleries which I have visited in the United States-- 1stly. That, in general, the grain is not sprouted. I have, however, seen some distillers who put 10lbs. of malt into a hogshead of fermentation containing 100 gallons, which reduces it to almost nothing. 2dly. That they put two bushels of ground grain into a hogshead of fermentation containing 100 gallons, filled up with water. 3dly. They had a ferment to determine the fermentation, which, when finished, yields two gallons of whiskey per bushel of grain, and sometimes ten quarts, but very seldom. I do not know whether those results are exact; but, supposing them to be so, they must be subject to great variations, according to the quality of the grain, the season, the degree of heat, of the atmosphere, and the manner of conducting the fermentation. From my analysing the different sorts of grains, I know that Indian corn must yield the most spirit. From the above proportions, it results, that 100 gallons of the vinous liquor of distillers yield only 4 gallons of whiskey, and very seldom 5; that is, from a 25th to a 20th. It is easy to conceive how weak a mixture, 25 parts of water to one of whiskey, must be; thus the produce of the first distillation is only at 11° or 12° by the areometer, the water being at 10°. It is only by several subsequent distillations, that the necessary concentration is obtained, to make saleable whiskey. These repeated operations are attended with an increased expense of fuel, labor, and time. Such are the usual methods of the whiskey distillers. Before we compare them with those of the brewer, let us examine the nature of fermentation, and what are the elements the most proper to form a good vinous liquor: thence we shall judge with certainty, of those two ways of operating. CHAPTER III. OF FERMENTATION. "Fermentation is a spontaneous and intestine motion, which takes place amongst the principles of organic substance deprived of life, the maximum of which always tends to change the nature of bodies, and gives rise to the formation of new productions." _Bouillon la Grange.--Manual of a Course of Chymistry._ Fermentation has long since been divided into _spirituous_, _acid_, and _putrid_. It is only since the revival or new epoch of chymistry, that the learned have been occupied in researches on fermentation. I was the first who gave a new hint on this important part of natural philosophy, in 1785. It was then held as certain, that the saccharine substance was the principle of spirituous fermentation. A series of experiments enabled me to demonstrate the contrary, for I obtained a well crystallized sugar by the fermentation of a substance which produces none by any other means. In September, 1785, I read a memoir to the Academy of Sciences, at Paris. In that memoir I developed my theory. That learned body nominated four commissioners, for the purpose of examining my operations, and sanctioned my discovery by a report, in which it was acknowledged that I had discovered a new truth, and ordered the insertion of my memoir in the collection of those of the Foreign Associates. I attributed the principle of the spirituous fermentation to the mucilaginous substance. This has been since demonstrated, by attentively observing that it always begins with a motion of acid fermentation, which is produced by the mucilaginous substance. The European chymists have since reasoned upon fermentation; each of them has produced a new system; none have been able to bring it to a regular demonstration; and the learned Gay Lussac has said, that fermentation is one of the most mysterious operations of chymistry. Be that as it may, there are facts that are ascertained: let us endeavor to investigate them, that we may derive from them all the information which is necessary to us. It is incontestable that spirits are produced by the saccharine substance. Grains, however, supply it, although they are not sensibly sweet. This has made me suspect that the fermentation is at first saccharine, which produces the sweet substance that is necessary for the formation of spirit. It is thus that, by a series of internal motions, the fermentation causes the formation of the spirit to be preceded by a slight production of acid; that it transforms the vinous liquor into vinegar, which the same fermentation changes in time into an animal substance, destroyed in its turn by the putrid fermentation. Such are the progressive changes operated by this all-disorganizing phenomenon, and the unerring march of nature to bring back all substances to their respective elements. The necessary conditions for the formation of vinous fermentation, are-- 1st. The presence of the saccharine substance. 2dly. That of a vegeto-animal substance, commonly called ferment, and soluble in water. 3dly. A certain quantity of water. 4thly. A temperature of 70° to 75°. 5thly. A sufficient mass. When these are obtained, in a short time the liquor becomes turbid; it bubbles, from the disengaging of the carbonic acid gaz, and the heat increases considerably. After some days, these impetuous motions subside; the fermentation ceases by degrees; the liquor clears up; then it emits a vinous smell and taste. As soon as it ferments no more, it must be distilled. However, some distillers have asserted that a greater quantity of spirit is obtained when the liquor has acquired a certain degree of acidity. Others are of opinion that it must be distilled as soon as it is calm. I am of this opinion, because the acid can only be formed at the expense of a little of the spirit, which is one of the principles of the acetous acid. Besides, the longer the liquor remains in a mass, the more spirit is wasted by evaporation. CHAPTER IV. OF THE PROPORTIONS OF THE ELEMENTS NECESSARY TO FORM A GOOD VINOUS LIQUOR. What are the proportions of the elements necessary to form a good vinous liquor? We owe the important knowledge of those proportions to the celebrated and unfortunate Lavoisier, who has proved, by the most accurate experiments, that there must be 100 parts of dry sweet substance, or sugar 400 parts of water 10 parts of ferment, or liquid yeast, which is reduced --- to 8 7-10ths of dry matter. 510 parts in the whole, which produce 57 parts of dry alcohol; that is, containing no more water than is necessary to its formation, and consequently as strong as it can be. Let us dwell for a moment upon the proportions just pointed out, and especially upon their result, which exceeds any thing that has ever been obtained. Supposing the weight of each of those parts to be one pound, we shall have 100 lbs. of dry sweet Substance, or sugar 400 do. of water 10 do. of liquid ferment --- 510 pounds in the whole. 100lbs. of sugar is the quantity required to make 12-1/2 gallons of sirup, composed of 8lbs. of sugar and 8lbs. of water per gallon, 12-1/2 galls. 400lbs. of water, at 8lbs. per gall. make 50 " The produce will be 57lbs. of dry alcohol. A vessel containing one ounce of water, filled up with this alcohol, weighs only 16dwts. and 16grs. From this report, it appears that the specific weight of the alcohol is, to the weight of the water, as 20 to 24; that is, that water weighs 1/5 more than alcohol. If the 57lbs. thus obtained were only water, it would only represent 7-1/8* gallons; but being alcohol, it weighs 1/6* less, and consequently gives 7-1/8 gallons more, the sixth of this quantity, (to wit:) 1-1/6* gallons, which, added to 7-1/8*, make 8-7/24 gallons. [TR: Poor quality made it difficult to verify the above numbers and so noted with an asterisk] But 1 gallon of dry alcohol, extended in 2 gallons of water, gives 3 gallons of liquor at 19°, which is called Holland, or first proof; a produce surpassing all what has been hitherto known to the distillers. I will prove it by an example: 1 gallon of molasses yields only 1 gallon of rum, at 19°, to the rum distiller; still, molasses is a true sirup, composed of 8lbs. of sugar, or sweet matter, more fermentable than sugar. 12-1/2 gallons of molasses, representing 100lbs. of dry sweet matter yield consequently 12-1/2 galls. of rum, Holland proof, which is only half the produce obtained by Lavoisier; an immense difference capable of exciting the emulation of all distillers, as it proves the imperfection of the art. What are the causes of such a dissimilarity of product? We must seek for them. 1st. In the difference of the strength of the vinous liquor. Lavoisier employed only 4 parts of water to 1 part of dry sugar. The rum distiller usually puts 10 gallons of molasses to 90 gallons of water, or the residue of the preceding distillations. 10 galls. molasses contain 80 lbs. of sweet matter. 90 gallons of water weigh 720lbs.; therefore the proportion is, one part of sweet matter to 9 parts of water--whilst that indicated by Lavoisier is only 4 parts of water to 1 part of sugar.[A] It is obvious how much richer this last must be, and that the fermentation thus produced has an energy far superior to the other. Thence results a rapid production of spirit, operated in a short time; whilst that of the rum distiller languishes more or less, and a slow fermentation wastes part of the spirit which it produces, even as it is forming. 2dly. Bodies evaporate in proportion to the extent of their surface. One hogshead of 100 gallons, should contain, according to Lavoisier's composition, the elements of 50 gallons of spirit, at 19°; whilst that of the rum distiller contains only 12. Now, as every fermentable liquor requires open vessels, the hogshead of the rum distiller loses as much spirit as that of Lavoisier: hence it is plain how far the above proportion operates to the disadvantage of the fermer. 3dly. Another source of loss arises in the distilling vessels themselves. Nothing is more imperfect than the stills of a whiskey distillery. Lavoisier's were so perfect, that he made the analysis and the synthesis in the most delicate operations [B]. The vessels of the whiskey distillers, far from being hermetically closed, allow the spirit to evaporate through every joint. And this is not all: corroded by the acetous acid, they are full of small holes, particularly in the cap, where all the vapors collect themselves, as in a reservoir. It is easy to conceive with what rapidity they escape, which occasions a considerable waste of liquor. In proof of the truth of this observation, we may refer to the smell of whiskey, so strongly perceivable on the roads leading to a distillery, and preceeding from no other cause than that liquor wasting out of bad vessels, to the great loss of the distiller. 4thly. A fourth cause of loss arises from the worm of the still. However careful in keeping the surrounding water cool, there is always one portion of vapor not condensed. This is made more sensible in the winter, when the cold of the atmosphere makes every vapor visible; upon examination, it will be seen that the running stream of liquor is surrounded with it. In my description of my apparatus, I give the means of obviating that evil. To these several causes, may we not add another? May not the production of spirit be in a ratio to the richness of the fermenting liquor? It is certain, that in every spirituous fermentation there is a portion of the sweet matter which remains undecomposed and in its original state. Lavoisier found that it was 4.940; that is, nearly 5 parts in 100. It may possibly be the same in a weaker liquor; which would increase the loss, in the inverse ratio of the density of the liquor. Such are the causes to which I attribute the great superiority of Lavoisier's products; and from those observations I thought I could establish the fabrication of whiskey upon new principles. CHAPTER V. A COMPARISON OF THE PROCESSES OF THE BREWER WITH THOSE OF THE WHISKEY DISTILLER. From the experiments of one of the most learned chymists of Europe, it has been demonstrated, that the proportions the most advantageous to the formation of a good vinous liquor, are, one part of dry sweet substance to four parts of water; that is, that the sugar must form one fifth of the whole. We have, moreover, seen that 100lbs. of dry sweet matter gave 25 gallons of spirit 19°, which comes to 4lbs. of sugar per gallon. We shall make use of that scale in comparing the processes of the brewer with those of the whiskey distiller. Supposing the bushel of grain to weigh 50 pounds, and that it gives 2 gallons of whiskey at 19°, each of which gallons is the product of 4lbs. of sugar; then the strong beer which contains in 40 gallons the sweet matter of 200lbs. of grain, contains the elements of 8 gallons of spirit, or 32lbs. of dry sweet substance; and as the 40 gallons of this beer weigh 320lbs. the 32lbs. of sugar form only one-tenth of it, which is one half of Lavoisier's proportions. Those of the distiller of whiskey are 100lbs. of grain to 100 gallons of water, or thereabouts: 100lbs. of grain contain only 16lbs. of dry sweet matter: therefore, as the 100 gallons of vinous liquor weigh 800lbs. the 16lbs. of sugar form only its fiftieth part. Thence is seen how inferior the proportions of the whiskey distiller are to those of the brewer, and how far they are from good theory. But the brewer aims only at producing a sort of wine, and succeeds; while, the distiller wants to make spirit, and only obtains it in the manner the most expensive, and opposed to his own interest. CHAPTER VI DEFECTS IN THE USUAL METHOD OF MAKING WHISKEY. 1st. The most hurtful of all for the interests of the distillers, is undoubtedly the weakness of the vinous liquor. We have seen that the proportion of spirit is in a ratio to the richness of the fermenting liquor; that Lavoisier, by putting one-fifth of the mass of dry sugar, obtained twice as much spirit as the rum distiller, who puts in the same quantity, but drowns it in water. From those principles, which are not contested, the distiller, whose vinous liquor contains only one-fiftieth part of sweet matter, obtains the less spirit, and loses as much of it as he gets. 2dly. Another defect is joined to this: bodies are dissolved by reason of their affinity with the dissolving principle; the mucilaginous substance is as soluble in water as the saccharine substance. A mass of 100 gallons of water having only 16lbs. of sugar to dissolve, exerts it's dissolving powers upon the mucilaginous part which abounds in grains, and dissolves a great quantity of it. There results from that mixture, a fermentation partaking of the spirit and the acid, and if the temperature of the atmosphere is moderate, the acid invades the spirit, which is one of its principles: nothing remains but vinegar, and the hopes of the distiller are deceived. Some distillers have been induced, by the smallness of their products, to put in their stills, not only the fluid of the liquor, but the flour itself. Hence result two important defects. 1st. The solid matter precipitates itself to the bottom of the still, where it burns, and gives a very bad taste to the whiskey. In order to remedy this inconvenience, it has been imagined to stir the flour incessantly, by means of a chain dragged at the bottom of the still, and put in motion by an axis passing through the cap, and turned by a workman until the ebullition takes place. This axis, however well fitted to the aperture, leaves an empty space, and gives an issue to the spirituous vapors, which escaping with rapidity, thereby occasion a considerable loss of spirit. 3dly. The presence of the grain in the still, converted into meal, is not otherwise indifferent. It contains a kind of essential oil, more or less disagreeable, according to its nature; which distils with the spirit. That of Indian corn, in particular, is more noxious than that of any other grain; and it is the presence of meal in the stills, which causes the liquors obtained from grains to be so much inferior to that of fruits. 4thly. There is a fourth defect, at which humanity shudders, and which the laws ought to repress. Vinous liquors are more or less accompanied with acetone acid, or vinegar; but those proceeding from grain contain still more of this acid. The stills are generally made of naked copper; the acid works upon that metal, and forms with it the _acetate of copper_, or verdigrise, part of which passes with the whiskey. There is no distiller, who, with a little attention, has not observed it. I have always discovered it in my numerous rectifications, and at the end of the operation, when nothing more comes from the still but what is called the sweet oil of wine. An incontestable proof of this truth is, that as the stills of the distillers are of a green color in their interior part; that they are corroded with the acid, and pierced with numberless little holes, which render them unfit for use in a very short time. It is easy to conceive how hurtful must be the presence of verdigrise to those who make use of whiskey as a constant drink: even those who use it soberly, swallow a slow poison, destructive of their stomach; while to those who abuse it, it produces a rapid death, which would still be the consequence of abuse, if the liquor was pure, but is doubly accelerated by the poison contained in the whiskey. It is easy to remedy so terrible an evil. The acetous acid has no action upon tin. By tinning the stills, the purity of the liquor will be augmented, and the distilling vessels, already so expensive, will be longer preserved. This operation must be renewed every year. The worms must likewise be tinned, if they are copper; but they are better of tin, or of the purest pewter. Such are the defects of the present method of distilling whiskey. Having exposed them, I must present the means of bringing to perfection the fabrication of a liquor of such general use. CHAPTER VII. DESCRIPTION OF THE PROCESS THE MOST ADVANTAGEOUS TO MAKE WHISKEY. [TR: The next two paragraphs were cut short, however attempted re-constructed for clarity] As it is demonstrated that the spirit is the more abundant in proportion to the richness of the vinous liquor,* it is therefore necessary to enrich that of the distillery* which is so deficient in that respect. An exposition of* my processes will point out the means I employ to attain* that end. A large whiskey distillery should be* able to make 100 gallons per day, or three barrels* making altogether that quantity. One gallon of spirit being the produce of 4 pounds* of dry saccharine matter, we must therefore have 400 pounds of this substance for the 100 gallons we wish to obtain. If 1 bushel of grain gives 2 gallons of whiskey, there must be 50 to obtain a daily result of 100 gallons. I take Indian corn as the basis of the fabrication, as that of all the grains which yields the most. For, from my method, whatever grain is employed, the spirit is equally pure. I divide the still house into three different rooms, to wit: One for Infusion; One for Fermentation; One for Distillation. CHAPTER VIII. THE ROOM OF INFUSION. It is here that the liquor destined to make whiskey, should be prepared, and made rich enough to procure a good fermentation. To this effect, there must be a mill with a vertical stone, moved by a horse, or any other means of motion. Those mills are too well known for me to describe them more amply. The corn must be coarsely ground, so as scarcely to be broke into three or four pieces: consequently the stone must not be too heavy, for, at all events, the grain had better be too coarse than too fine. That mill should be placed in the infusion room, so as not to keep it dirty, nor to be too much in the way. It must grind, or rather break, 50 bushels per day. There must be a square kettle, 4 feet broad, 5 feet long, 1 foot deep. The kettle must be made in sheets of copper, one line thick, at least: the bottom, although flat, should have a slight swell inside, so as to avoid the expansion of the metal outside, from the action of the fire. This kettle must be placed upon a brick furnace, so that the longest parts should bear forwards, and the other against the chimney, from which it must be separated by a brick wall eight or nine inches. The sides, around which there must be a space to walk freely, should be supported by a wall 1-1/2 feet deep; the fore part upon such a wall, in the middle of which is an iron door, fifteen inches square, in an iron frame, through which the fuel is introduced. The kettle is mounted upon the furnace, so as to bear upon the four walls about 4 inches, and rests upon a bed of clay, which must leave no passage to the action of the fire; it is lined externally with bricks, and must have a pipe on one of its sides, to draw off the liquor. Under the kettle, 15 inches from the bottom, is a flue for the heat, running through all its length. It is 2-1/2 feet wide at bottom, extending like a fan at the top, about 6 inches on each side, so that the flame may circulate in all the breadth of the kettle. On the fore part of this flue, facing the door, is a hearth, occupying all its breadth, and 2 feet long. The rest of the flue is paved with bricks, and rises insensibly 4 inches towards the chimney, in which it opens by two holes, 1-1/2 inches wide, 8 or 9 inches high. Immediately under the hearth, is a mash hole 4 feet deep, occupying all its capacity, and projecting 2 feet forward. This opening is necessary to keep up a free circulation of air, and to take up the ashes. It should be covered with strong boards, not to hinder the service of the kettle. The hearth is made with an iron grate, more or less close, according to the nature of the fuel; if for wood, the bars must be about two inches apart; if for coals, half an inch is sufficient. The furnace must be built with care. The parts most exposed to the action of the fire must be built with soft bricks and potters' clay: soap stone would be preferable, if easy to procure. The brick separating the kettle and chimney, must be supported with flat bars of iron, as well as the part over the door. CHAPTER IX. USE OF THE KETTLE. The kettle is destined to make the infusion of the grain, and boil it so as to convert it into wort. By that operation I make the liquor richer, which I intend for fermentation, and bring it to divers degrees of strength. I put into the kettle 100 gallons of water, and 4 bushels of corn, broken, as I said before, at the mill. I light a small fire, which I increase gradually, until the water begins to boil; during that time, the grain is stirred with a paddle. As soon as the ebullition is established, the grain is taken up with a large skimmer, and put to drain into a large basket hanging over the kettle; and when the grain has been totally taken up, the fire is increased so as to bring the water to boil again, until reduced to two-fifths, which degree of concentration is not rigorous, and the distiller may augment it as his experience shall direct. When thus concentrated, the liquor is drawn off through the pipe, and received into a tub or vat containing 130 or 140 galls. 100 gallons more of water are put into the kettle, with 4 bushels of corn; the fire conducted slowly, as before, until the degree of ebullition; the corn is taken off, and the liquor concentrated in the same proportions; then drawn off as above, in the same tub. The same operation is repeated for the third time; the three united liquors are slightly stirred, and, still warm, transported into one of the hogsheads of fermentation, which it nearly fills up. As there must be four of these hogsheads filled up daily, the work at the kettle must be kept going on, without interruption, until that quantity is obtained, which may be done in about twelve hours. The grain which has been drained is carried to dry, either in the open air, or in a granary, and spread thin. When dry, it is excellent food for cattle, and highly preferable to the acid and fermented mash, usually used by distillers to feed cattle and hogs: they eat the corn dried in the above manner as if it had lost nothing of its primitive qualities and flavor. CHAPTER X. THE ROOM FOR FERMENTATION. The room destined to the fermentation must be close, lighted by two or three windows, and large enough to contain a number of hogsheads sufficient for the distillery. It may be determined by the number of days necessary for the fermentation; 30 or 40 hogsheads may suffice, each of 120 or 130 gallons. In the middle of the room must be a stove, large enough to keep up a heat of 75° to 80°, even in winter. A thermometer placed at one end of the room, serves to regulate the heat. As soon as the liquor is in the hogshead, the yeast, or fermenting principle, is put into it, stirred for some moments, and then left to itself. A liquor as rich as the above described ferments with force, and runs with rapidity through all the periods of fermentation. It is fit to distil as soon as that tumultuous state has subsided and the liquor is calm. The essential character of the spirituous fermentation, is to exhale the carbonic acid gaz in great quantity. This gaz is mortal to mankind, and to all the living creation. Thirty hogsheads of fermenting liquor producing a great deal of this gaz, the room should be purified of it by opening two opposite windows several times a day. This is the more essential, as the pure air, or _oxigen_, contributes to the formation of the spirit, of which it is one of the constituting principles. A short time, however, suffices to renew the air of the room. It is useless to remark, that the hogsheads must be open at one end, and rest upon pieces of wood elevating them some inches from the ground. They must remain uncovered during the fermentation; and afterwards be covered with a flying lid, when the liquor is calm. CHAPTER XI. OF THE ROOM FOR DISTILLATION. We have hitherto considered the liquor as containing only principles upon which the air has no action, and from which it can only extract some watery vapors; and, in fact, all those principles contained in the liquor are fixed. The action of the fire may concentrate, but not volatilize them. The liquor is now changed by the fermentation; it contains no longer the same principles, but has acquired those which it had not, which are volatile, and evaporate easily. They must therefore be managed carefully, in order not to lose the fruits of an already tedious labor. The spirit already created in the fermented liquor, must be collected by the distillation; but in transporting it to the still, the action of the external air must be carefully avoided, as it would cause the evaporation of some of the spirit. A pump to empty the hogsheads, and covered pipes to conduct the liquor into the still, is what has been found to answer that purpose. A good distilling apparatus is undoubtedly the most important part of a distillery. It must unite solidity, perfection in its joints, economy of fuel, rapidity of distillation, to the faculty of concentrating the spirit. Such are the ends I have proposed to myself in the following apparatus. The usual shape of stills is defective; they are too deep, and do not present enough of surface for their contents. They require a violent fire to bring them to ebullition; the liquor at bottom burns before it is warm at the top. My still is made upon different principles, and composed of two pieces, viz. the kettle, and its lid. The kettle, forming a long square, is like the kettle of infusion, already described, and only differs from it in being one foot deeper. The lid is in shape like an ancient bed tester; that is to say, its four corners rise into a sharp angle, and come to support a circle 16 inches diameter, bearing a vertical collar of about two inches. This collar comes to the middle of the kettle, and is elevated about 4 feet from the bottom. The lid is fastened to the kettle. The collar receives a pewter cap, to which is joined a pipe of the same metal, the diameter of which decreases progressively to a little less than 3 inches: this pipe, the direction of which is almost horizontal, is 5 feet long. My still, thus constructed, is established upon a furnace like that of the infusion room. I observe that the side walls are only raised to the half of the height of the kettle. A vertical pipe is placed on the side opposite to the pewter one, and serves to fill up the still: it is almost at the height of the fastening of the lid, but a little above. On the same side, on a level with the bottom, is a pipe of discharge, passing across the furnace: this pipe must project enough to help to receive or to direct the fluid residue of the distillation; its diameter must be such as to operate a prompt discharge of the still. OF THE URNS. These are copper vessels, thus called from their resembling those funeral vases of the ancients. Mine have a bottom of about 18 inches diameter; they are two feet high, have a bulge of 6 inches near the top, and then draw in to form an overture of about 8 inches. On one side, towards the top, there is a copper pipe 2 inches diameter, projecting externally 2 or 3 inches, and bent in an elbow: it enters the internal part of the urn, and descends towards the bottom, without touching it; there it is only a slight curve, and remains open. The external part of that pipe is fitted to receive the pewter pipe of the still; they are made so as to enter into one another, and must fit exactly. The round opening at the top of the urn receives a cap with a pewter pipe, made like that of the still. It is likewise five feet long, and its size in proportion to the opening: this goes and joins itself to the second urn, as the still does to the first. The pipe of this second goes to a third, and the pipe of this last to the worm. The three urns bear each a small pipe of discharge towards the bottom. This apparatus must be made with the greatest care. Neither the joints, the different pipes of communication, nor the nailings, must leave the smallest passage to the vapors. The workman must pay the greatest attention to his work, and the distiller must lute exactly all the parts of the apparatus that are susceptible of it: he must be the more careful as to luting it, as this operation is only performed once a week, when the apparatus is cleaned. At the moment of the distillation, the master or his foreman must carefully observe whether there is any waste of vapors, and remedy it instantly. The still and urns ought to be well tinned. CHAPTER XII. EFFECTS OF THIS APPARATUS. Although the still might contain 400 gallons, there must be only 200 gallons put into it: the rest remaining empty, the vapors develops themselves, and rise. In that state, the vinous liquor is about one foot deep, on a surface of 20 feet square: hence two advantages--the first, that being so shallow, it requires but little fuel to boil; the second, that the extent of surface gives rise to a rapid evaporation, which accelerates the work. This acceleration is such, that six distillations might be obtained in one day. The spirit contained in the vinous liquor rises in vapors to the lid of the still, there find the cap and its pipe, through which they escape into the first urn, by the side pipe above described, which conducts them to the bottom, where they are condensed immediately. But the vapors, continuing to come into the urn, heat it progressively: the spirituous liquor that it contains rises anew into vapors, escapes through the cap and pipe, and arrives into the second urn, where it is condensed as in the first. Here again, the same cause produces the same effect: the affluence of the heat drawn with the vapors, carries them successively into the third urn, and from thence into the worm, which condenses them by the effects of the cold water in which it is immersed. The urns, receiving no other heat than that which the vapors coming out of the still can transmit to them, raise the spirit; the water, at least the greatest part of it, remains at the bottom: hence, what runs from the worm is alcohol; that is, spirit at 35°. It is easily understood how the vapors coming out of the still are rectified in the urns, and that three successive rectifications bring the spirit to a high degree of concentration: it gets lower only when the vinous liquor draws towards the end of the distillation. As soon as it yields no more spirit, the fire is stopped, and the still is emptied in order to fill it up again, to begin a new distillation. Each time that the vinous liquor is renewed in the still, the water contained in the urns must be emptied, through the pipes of discharge at the bottom. Metals are conductors of the _caloric_. The heat accumulated in the still, rises to the cap, from whence it runs into the urns: with this difference--that the pewter, of which the cap and pipes are made, transmits less caloric than copper, because it is less dense: and that bodies are only heated in reason of their density. However, a great deal of heat is still communicated to the worm, and heats the water in which it is immersed. I diminish this inconvenience by putting a wooden pipe between the worm and the pipe of the third urn. Wood being a bad conductor of caloric, produces a _solution of continuity_, or interruption between the metals. The wood of this pipe must be soft and porous, and not apt to work by the action of the fire: however, to avoid its splitting, I wrap it up in two or three doubles of good paper, well pasted, and dried slowly. This pipe is one foot long, and hollowed in its length, so as to receive the pewter pipe of the third urn at one end, and to enter the worm at the other; thereby the worm is not as hot, since it only receives the heat of the vapors which it condenses. Notwithstanding all these precautions, it heats the water in which it is immersed after a length of time; and whatever care may be taken to renew it, all the vapors are not condensed, and this occasions a loss of spirit. I obviate this accident, by adding a second worm to the first: they communicate by means of a wooden pipe like the above. The effect of this second worm, rather smaller than the first, is such, that the water in which it is plunged remains cold, while that of the first must be renewed very often. By these means, no portion of vapors escape condensation. The liquor running from the worm is received into a small barrel, care being taken that it may not lose by the contact of the air producing evaporation. CHAPTER XIII. OF FERMENTS. They are of two kinds; the very putrescent bodies, and those supplied by the _oxigen_. Animal substances are of the first kind: _acids_, neutral salts, rancid oils, and metallic _oxids_, are of the second. Were I obliged to make use of a ferment of the first class, I would choose the glutinous part of wheat flour. This vegeto-animal substance is formed in the following manner:--A certain quantity of flour is made into a solid dough, with a little water. It is then taken into the hands, and water slowly poured over it, while it is kneaded again. The water runs white, because it carries off the starchy part of the flour; it runs clear after it is washed sufficiently. There remains in the hands of the operator a dough, compact, solid, elastic, and reduced to nearly the half of the flour employed. This dough, a little diluted with water, and kept in the temperature indicated for the room of fermentation, passes to the putrid state, and contracts the smell of spoiled meat. Four pounds of this dough per hogshead, seem to me to be sufficient to establish a good fermentation. A small quantity of good vinegar would answer the same purpose, and is a ferment of the second class. But are those means indispensable with my process? I do not think so. 1st. The richness of my vinous liquor, and the degree of heat to which I keep it, tend strongly to make it ferment. In fact, the infusion of the grain, by taking from it its saccharine part, takes likewise part of its mucilaginous substance, which is the principle of the spirituous fermentation, which it establishes whenever it meets with the other substance. 2dly. The hogsheads themselves are soon impregnated with a fermenting principle, and communicate it to the liquor that is put into them. 3dly. The rum distiller employs advantageously the residue of his preceding distillation, to give a fermentation to his new molasses: this residue has within itself enough of acidity for that purpose. Might not the residue of the distillation of my vinous liquor have the same acidity? It contains only the mucilaginous substance already acidulated. Some gallons of that residue to every hogshead, would, I think, be a very good ferment. Lastly. Here is another means which will certainly succeed: it is to leave at the bottom of each hogshead three or four inches of the vinous liquor, when transported into the still for distilling. This rising, which will rapidly turn sour, will form a ferment sufficient to establish a good fermentation. The intelligent manager of a distillery must conduct the means I indicate, towards the end which he proposes to himself, and must carefully avoid to employ as ferments, those disgusting substances which cannot fail to bring a discredit on the liquor in which they are known to be employed. CHAPTER XIV. OF THE AREOMETER, OR PROOF BOTTLE. This instrument is indispensable to the distiller: it ascertains the value of his spirits, since it shows the result of their different degrees of concentration. I will give the theory of this useful instrument, as it may be acceptable to those who do not know it. Bodies sink in fluids, in a _compound ratio_ to the volume and the density of those fluids, which they displace. It is from that law of nature, that a ship sinks 20 feet in fresh water, while it sinks only about 18 feet in sea water, which has more density on account of the salt dissolved therein. The reverse of this effect takes place in fluids lighter than water, as bodies floating in them sink the more, as the liquor has less density. Upon those principles are made two kinds of areometers--one for fluids denser than water; the other for those that are lighter: the first are called _salt proof_; the second _spirit proof_. Distilled water is the basis of those two scales: it is at the top for the _salt proof_, and at the bottom for the _spirit proof_; because the first is ascending, and the other descending; but by a useless singularity, the distilled water has been graduated at 10° for the spirit proof bottle, and at 0 for the _salt proof_. We shall only dwell upon the first, because it is the only one interesting to the distiller. Water being graduated at 10° in the areometer, it results from thence that the spirit going to 20°, is in reality only 10° lighter than water; and the alcohol gaaduated [TR: graduated] at 35°, is only 25° above distilled water. The areometer can only be just, when the atmosphere is temperate; that is, at 55° Fahrenheit, or 10° Reaumur. The variations in cold or heat influence liquors; they acquire density in the cold, and lose it in the heat: hence follows that the areometer does not sink enough in the winter, and sinks too much in the summer. Naturalists have observed that variation, and regulated it. They have ascertained that 1° of heat above temperate, according to the scale of Reaumur, sinks the areometer 1/8 of a degree more; and that 1° less of heat, had the contrary effect: thus the heat being at 18° of Reaumur, the spirit marking 21° by the areometer, is really only at 20°. The cold being at 8° below temperate, the spirit marking only 19° by the areometer, is in reality at 20°. 2-1/4 of Fahrenheit corresponding to 1° of Reaumur, occasion in like manner a variation of 1/8 of a degree: thus, the heat being at 78-1/2°, the spirit thus marking 21°, is only at 20; and the cold being at 87°, the spirit marking only 19° by the areometer, is in reality at 20°. It is easily conceived, that extreme cold or extreme heat occasion important variations. For that reason, there are in Europe inspectors, whose duty it is to weigh spirits, particularly _brandy_: for that purpose they make use of the areometer and the thermometer. An areometer, to be good, must be proved with distilled water, at the temperature of 55°. Areometers, being made of glass, are brittle, and must be used with great care. This inconvenience might be remedied, by making them of silver; I have seen several of this metal. A good silversmith could easily make them; I invite those artists to attend to that branch of business; it might become valuable, as the distillers will be more enlightened. CHAPTER XV. ADVANTAGES OF MY METHOD. The first of all, is derived from the composition of a vinous liquor, richer, and more proper to raise a vigorous fermentation, than that which is obtained by the usual method. Now, as it is proved that the quantity of spirit is in proportion to the richness of the fermenting liquor, mine therefore yields a great deal more spirit than any other. 2dly. We have seen that a heat of 75° or 80° must be kept up in the fermenting room: this being summer heat, proves that such a rich vinous liquor runs no risk of passing to the acid state with as much rapidity as that of the common distillers; and, consequently, that he who will follow my method can work all the year round without fear of losing the fruits of his labor, as it often happens--an advantage precious for him who makes it his sole business. The only change he has to make, is to suppress the heat of the stove, when the temperature of the atmosphere is sufficient to keep up a good fermentation in the liquor. As to my distilling apparatus, this is not a new idea. I present it to the public under the sanction of experience. I had it executed in Philadelphia eight years ago, after having obtained a patent. It was made for a rum distillery, where they still continue to use it. It presents the greatest advantages. The first is, that with a single fire, and a single workman, I distil and rectify the spirit three times, and bring it to the degree of alcohol; that is, to the greatest purity, and almost to the highest degree of concentration. 2dly. It lowers the cost of transportation, by two-thirds; because one gallon at 35° represents three gallons at the usual degree. The merchant, being arrived at the place of his destination, has only to add 2 gallons of water to 1 gallon of this alcohol, in order to have 3 gallons of whiskey; which is of a considerable advantage, either for land or sea carriage. 3dly. As the price of spirits is, in trade, in proportion to their degree of concentration, those made with my apparatus being at a very high degree, need no more rectifying, either for the retailer, the apothecary, or the painter; and the considerable expenses of that operation turn entirely to the profit of the distiller, as they are totally suppressed. Distillers may hereafter sell spirits of all degrees of concentration. Such are the advantages of my processes. I offer them the more willingly to the public, as they are founded upon the most approved principles of natural philosophy: by reflecting upon them, distillers will be easily convinced of it. * * * * * However perfect the description of a new thing may be, our ideas of it are always defective, until we have seen it put into practical use. Few men have the means of establishing a distillery on a new plan, and even the most enlightened may make notable errors. Few, besides, are bold enough to undertake, at their own risks, the trial of a new fabrication: they are afraid of losing, and of being blamed for having too lightly yielded to the persuasion of new projectors. Hence it follows that a useful discovery falls into oblivion, instead of doing any good. But no discovery of general utility ought to experience that fate in a republic. Government itself ought to promote the first undertaking, or a certain number of citizens ought to join in order to give it a start. It is the more easy in this case, as my apparatus requires very little expense. If a distillery according to my directions, was established in some of the principal towns of the state, my method would then make rapid progress, and thus prove the truth of the principle which I have advanced; and the distillers, after having meditated upon my method in this book, would come and satisfy themselves of its goodness, by seeing it put into practice, and yielding the most perfect results, with all the advantages for trade that may be expected: hence would naturally ensue the rapid increase of distillation, and consequently that of agriculture and commerce. THE ART OF MAKING GIN, AFTER THE PROCESS OF THE HOLLAND DISTILLERS. Having indicated the most proper means of obtaining spirits, I will now offer to the public the manner of making _Gin_, according to the methods used by the distillers in Holland. It may be more properly joined to the art of making whiskey, as it adds only to the price of the liquor, that of the juniper berries, the product of which will amply repay its cost. Many distillers in the United States have tried to imitate the excellent liquor coming from Holland, under the name _gin_. They have imagined different methods of proceeding, and have more or less attained their end. I have myself tried it, and my method is consigned in a patent. But those imitations are far from the degree of perfection of the Holland gin: they want that unity of taste, which is the result of a single creation; they are visibly compounds, more or less well combined, and not the result of a spontaneous production. To this capital defect, which makes those imitations so widely different from their original, is joined their high price, which prevents its general consumption. In fact, it is made at a considerable expense: the whiskey must be purchased, rectified and distilled over again with the berries. These expenses are increased by the waste of spirit occasioned by those reiterated distillations. This brings the price of this false gin to three times that of the whiskey: consequently the poorer sort of people, whose number is always considerable, are deprived of the benefits of a wholesome liquor, and restrained to whiskey, which is commonly not so. The methods used in Holland, have reduced gin to the lowest price; that of the juniper berries being there very trifling, and increasing but little the price of whiskey: still that small addition is almost reduced to nothing, as will be seen hereafter. The United States are, in some parts, almost covered with the tree called here _cedar_; which tree is no other than the juniper, and grows almost every where, and bears yearly a berry, which is in reality the juniper berry. Some Hollanders knew it at Boston, collected considerable quantities of it in Massachusetts, and shipping it to some of the eastern harbors, sold it as coming from Holland. I have seen some at Philadelphia ten years ago, at the house of a Hollander, who received it from Massachusetts in hogsheads of about ten hundred weight, and sold as the produce of his own country, what was really that of the United States. I collected myself a great quantity of those berries, at Norfolk, Va. by means of negroes, to whom I paid one dollar per bushel of 40 lbs. being 2-1/2 cts. per pound. Two years ago, it sold for 6 cents in Philadelphia, and bore the same price at Pittsburgh. There is a great deal of cedar in Kentucky, and consequently of berries. I have seen them at Blue Licks, and they abound near the Kentucky river. Although an incredible number of those trees is cut down daily, there is still a greater number standing, in the United States; and millions of bushels of berries are lost every year, while only skilful hands are wanted, to make them useful to mankind. The juniper berry has many medical properties: it is a delightful aromatic, and contains an oil essential, and a sweet extract, which by the fermentation yields a vinous liquor, made into a sort of wine in some countries; that is called wine for the poor: it strengthens the stomach, when debilitated by bad food or too hard labor. The Hollanders, who have long had the art of trading upon every thing, have constantly turned even their poverty to account. They have immense fabrications of gin, and scarcely any juniper trees. They only collect the berry in those countries where it is neglected as useless, as in France and Tyrol, which produce a great deal of it. The United States need have no recourse to Europe, in order to get the juniper berries: they have in abundance at home, what the Hollanders can only procure with trouble and money. They can therefore rival them with great advantage; but they must follow the same methods employed in the Holland distilleries. The juniper berry contains the sweet mucous extract, in a great proportion: it has therefore the principle necessary to the spirituous fermentation; and, indeed, it ferments spontaneously. When fresh, and heaped up, it acquires a degree of heat, but not enough to burn, as I have ascertained: it is therefore safely transported in hogsheads. From that facility of fermenting, it must be considered as a good ferment, and as increasing the quantity of spirit, when joined to a fermentable liquor. A distiller may at pleasure convert his whiskey into gin. He needs only to perfume the wort which he puts in fermentation, by adding a certain quantity of the berries, slightly broken: the fermentation is then common to both; their sweet mucosity enriches that of the wort, and increases the spirit, while at the same time the soapy extract, which is the proximate principle of vegetation, yields the essential oil, which perfumes the liquor.[C] The fermentation being common to both substances, unites them intimately; and when, by the distillation, the spirit is separated from the water, there remains an homogenous liquor, resulting from a single creation, and having that unity of taste, and all the properties of Holland gin, because obtained by the same means. One single and same distillation can therefore yield to the distiller either gin or whiskey, as it requires no more labor, and its conversion into gin costs only the price of the berries, which repays him amply, either by the spirit it yields, or by its essential oil, which, floating on the surface, may be easily collected. This oil bears a great price, and the Hollanders sell much of it. We have seen, in the 10th chapter of this work, that my hogsheads for the fermentation, contain about 120 gallons of wort, being the production of the saccharine extract of 12 bushels of grain. The intelligent distiller will himself determine the quantity of berries necessary for each hogshead to have a good aromatic perfume. He may begin with 10 lbs. per hogshead; and will, upon trial, judge whether or not this quantity is sufficient, or must be increased. At any rate, economy should not be consulted in the use of the berries, since their price does not increase that of the whiskey. This low price must naturally become the principle of an immense fabrication of gin; and henceforth it will be an important article of exportation for the United States, as well as a considerable and wholesome object of home consumption. FOOTNOTES: [A] Some rum distillers make a stronger vinous liquor, but it is still very far from Lavoisier's proportions. Others add successively new molasses to their vinous liquor, and thus prolong their fermentation, without making their liquor stronger, and consequently without obtaining more spirit. This is absolutely contrary to the true principles of distillation. [B] See his beautified operation on the decomposition of water. [C] I must here observe, that the juniper berry, as well as several other fruits, contains two kinds of essential oil: one is the proximate principle of vegetation, and the other is the superabundant oil: the first is combined with the soapy extract, and dissolves in water; while the second does not unite with it, and floats on the surface. END 
29375	----	Manufacturing Cost Data ON Artificial Ice MADE IN ACCORDANCE WITH OTTO LUHR CONSULTING ENGINEER & HERMAN FRIEDL ARCHITECT ICE MAKING SYSTEM PATENT APPLIED FOR 154 WEST RANDOLPH STREET CHICAGO, ILL. Ice for Commercial Purposes Ice for commercial purposes is obtained in two ways: either by cutting during the winter time from our lakes and rivers and storing in large Ice Storage Houses located alongside, or by freezing pure clean water by means of artificial refrigeration. All authorities are agreed that artificial ice is more sanitary than natural ice and it is only a matter of time when the use of natural ice will be prohibited except in special cases when the purity of its source of supply is beyond doubt. Our improved method of making artificial ice will cut the labor cost down to the minimum and will enable the manufacturer to profitably sell artificial ice at the price natural ice can be harvested. The logical result thereof will be the building of a large number of modern ice plants all over the country to supply the market with artificial ice in place of the present natural ice. We do not claim any wonders for our system but believe that the following points of advantage will convince any practical ice manufacturer that the labor cost has been cut in two. First. We pull a complete row of the full width of tank at one time. Second. Our air supply is permanently connected to the cans and the supply to each can can be regulated, if required. Third. We have a continuous air supply to the cans during freezing as well as during thawing, dumping and filling. Our air supply never ceases. Fourth. Our air is automatically cooled down to the temperature of the brine in the tank thereby eliminating all possibility of moisture in the air pipes. Fifth. Our cans are held in a solid frame of steel work and are connected to the crane from the time the cans are pulled until they are put back into the tanks, thereby doubling the life of the cans. We give herewith data covering the cost of manufacturing ice and will guarantee that under reasonably fair management the number of men required will not be exceeded. Do not fail to carefully analyze the following cost data. They may seem extremely low but a thorough study of our system will prove them to be very conservative. [1] NUMBER ONE Manufacturing Costs Per Ton of Ice Using Electric Power at Present Chicago Rates for Power and Labor Capacity of plant, 240 tons of ice per day, using 2692 cans of 400-lb. capacity. 18000-ton storage house. Average current requirement for freezing one ton of ice, including storage cooling and all auxiliaries, 55 K. W. hours. Average cost per K. W. hour, .9 cent. Current cost per ton of ice, 55 x .9, equals 49.6 cents. Assuming one month's shut-down for inspection and repairs, the total output of 240 tons of ice for 333 days amounts to 79,920 tons, or roughly speaking 80,000 tons of ice. Adding 1/2 cent per ton of ice for the required heating, the total power cost of making 80,000 tons of ice is (80,000 x .50) $ 40,000.00 ENGINE ROOM LABOR COST: 1 chief engineer per day $ 10.00 3 engineers per day $ 8.00 Total per day $ 34.00 365 days at $34.00 equals $ 12,410.00 or 12410 / 80000 = 15.62 cents per ton [2] ICE PLANT LABOR COST: 3 men pulling ice and setting it up in store-room. per day $ 6.00 3 men in store-room per day $ 6.00 1 shipping clerk per day $ 8.00 Total labor per day $ 44.00 365 days at $44.00 equals 16,060.00 For filling the winter storage house and taking the ice out of it will require 3 additional men for five months, equals 150 days x $18.00, equals $ 2,700.00 Total Ice Plant Labor Cost Equals $18,760.00 or 18670 / 80000 = 23.46 cents per ton 240 tons of ice equal 1200---400-lb. cans. As 24 cans are pulled at one time it requires 1200 / 24 = 50 pulls per day, or one pull every 29 minutes. The ice-puller has therefore ample time to set up all ice pulled in storage house as directed. Cost of Ammonia at 2 cent per ton $ 1,600.00 Cost of Oil and Waste at 2 cent per ton $ 1,600.00 Cost of Water at 3 cent per ton $ 2,400.00 Cost of Salt at 72 cent per ton $ 400.00 Plant Maintenance and Repairs $ 3,500.00 or 3500 / 80000 = 4.37 cent per ton OFFICE EXPENSES: 1 Manager and Salesman, per year $ 5,000.00 1 Bookkeeper, per year $ 2,400.00 Stationery, Telephone, etc $ 600.00 Total Cost $ 8,000.00 or 8000 / 80000 = 10 cent per ton [3] OVERHEAD CHARGES: 8 per cent interest on $350,000.00 investment $ 28,000.00 8 per cent interest on value of land ($20,000.00) $ 1,600.00 8 per cent interest on $10,000.00 working capital $ 800.00 3 per cent depreciation on $350,000.00 $ 10,500.00 Insurance (estimated) $ 1,500.00 Taxes (estimated) $ 3,500.00 Total $ 45,900.00 or 45900 / 80000 = 57.375 cent per ton Total Expense $134,570.00 or 134570 / 80000 = $1.68.215 per ton Divided as follows:-- Manufacturing cost including office expense $ 1.10.840 Overhead charges $ 0.57.375 ICE SALES ASSUMPTIONS: Month Ice Ice sold Ice stored Ice Sold Total Ice produced direct per day from storage stored in 30 per day per day daily days January 240 65 175 5250 February 240 65 175 5250 March 240 115 125 3750 April 240 165 75 2250 May 240 300 60 June 240 400 160 July 240 400 160 August 240 400 160 September 240 350 110 October 240 200 40 1200 November 240 140 100 3000 December None 65 65 Tons 20700 Less Tons 1950 Total Tons 18750 During the month of December, the Ice Plant will be shut down for overhauling and repairs, and part of the ice stored during November will be sold in December, therefore, requiring a total storage capacity of 18,750 tons, of which 750 tons will be stored in the ante-room and 18,000 tons will be stored in the big winter storage. [4] NUMBER TWO Manufacturing Costs Per Ton of Ice Using Electric Power at Present Chicago Rates for Power and Labor 240 TON CAPACITY PER DAY No Storage House for Surplus Ice ICE SALES ASSUMPTIONS: Tons per day Total Tons January 65 1,950 February 65 1,950 March 115 3,450 April 165 4,950 May 240 7,200 June 240 7,200 July 240 7,200 August 240 7,200 September. 240 7,200 October 200 6,000 November 140 4,200 December 65 1,950 Total output tons 60,450 NOTE--These sales can only be realized if the dealer has at least 18,000 tons of natural ice on hand to enable him to take care of the family trade during the hot months. If no large supply of natural ice is on hand hardly 50,000 tons can be sold, thereby increasing the cost per ton considerably. POWER COST: Due to numerous starting and stopping of compressor during the slack months the maximeter charges will be higher and therefore it must be assumed that 60 K. W. hours will be required per ton of ice instead of 55 K. W. hours for continuous consumption. 60 K. W. hours per ton of ice at .9 cent per K. W. hour equals 54 cents per ton. Adding 1/2 cent per ton for the required heating the power cost for making 60,450 tons of ice equals 60,450 x 54.5 cents, equals $ 32,945.25 [ 5 ] ENGINE ROOM LABOR COST: 1 chief engineer per day $ 10.00 3 engineers per day $ 8.00 Total per day $ 34.00 365 days at $34.00 equals $ 12,410.00 or 12410 / 60450 = 20.54 cent per ton of ice ICE PLANT LABOR COST: (Using present method of pulling ice) May, June, July, August, September and October require: 6 ice pullers per day $ 6.00 3 air men per day $ 6.00 6 storage house men per day $ 6.00 Total per day $ 90.00 184 days at $90.00 equals $ 16,560.00 March, April and November require: 6 pullers per day $ 6.00 4 storage house men per day $ 6.00 Total per day $ 60.00 91 days at $60.00 equals $ 5,460.00 December, January and February require: 3 pullers per day $ 6.00 3 storage house men per day $ 6.00 Total per day $ 36.00 92 days at $36.00 equals $ 3,312.00 1 shipping clerk per day $ 8.00 330 days x 8 equals $ 2,640.00 Total Labor Cost $ 27,972.00 or 27972 / 60450 = 46.27 cent per ton Cost of Ammonia at 2 cent per ton $ 1,209.00 Cost of Oil and Waste at 2 cent per ton $ 1,209.00 Cost of Water at 3 cent per ton $ 1,813.50 Cost of Salt at 1/2 cent per ton $ 302.25 Plant Maintenance and Repairs $ 2,800.00 or 2800 / 60450 = 4.63 cent per ton [6] OFFICE EXPENSE: 1 Manager and Salesman per year $ 5,000.00 1 Bookkeeper per year $ 2,400.00 Stationery, Telephone, etc $ 600.00 Total Cost $ 8,000.00 or 8000 / 60450 = 13.23 cent per ton OVERHEAD CHARGES: 8 per cent Interest on $280,000.00 investment $ 22,400.00 8 per cent Interest on value of land ($12,000.00) $ 960.00 8 per cent interest on $8,000.00 working capita $ 640.00 3 per cent depreciation on $280,000.00 $ 8,400.00 Insurance (estimated) $ 1,200.00 Taxes (estimated) $ 2,500.00 Total Overhead Charge 36,100.00 or 36100 / 60450 = 69.72 cent per ton Total Expense $124,961.00 or 124961 / 60450 = $2.06.72 per ton NOTE--If the LUHR & FRIEDL ICE MAKING SYSTEM is used, the Ice Plant Labor Cost will be as follows: May, June, July, August, September and October require: 3 ice pullers per day $ 6.00 3 storage house men per day $ 6.00 Total per day $ 36.00 184 days at $ 36.00 equals $ 6,624.00 March, April and November require: 3 ice pullers per day $ 6.00 2 storage house men per day $ 6.00 Total per day $ 30.00 91 days at $ 30.00 equals $ 2,730.00 December, January and February require: 3 ice pullers per day $ 6.00 1 storage house man per day $ 6.00 Total per day $ 24.00 92 days at $ 24.00 equals $ 2,208.00 1 shipping clerk per day $ 8.00 330 days x 8 equals. $ 2,640.00 Total Labor Cost. $ 14,202.00 or 14202 / 60450 = 23.49 cent per ton compared to 46.27 cent per ton, A SAVING OF 22.78 CENT PER TON. [7] [Illustration: Typical Design of a 160 Ton Steam Driven Ice Plant. Interior Details.] [8] [Illustration: Typical Design of a 160 Ton Steam Driven Ice Plant.] Exterior Cross Section In connection with Otto Luhr Consulting Engineer & Herman Fridel Architect Ice Making System Patent Applied For [9] NUMBER THREE Manufacturing Costs Per Ton of Ice Using Steam Power at Medium-Sized-Town Rates for Labor 160-ton capacity per day. 1,728--400-lb. cans. 333 days continuous full output. 12,000-ton storage house. COST OF POWER: A modern, highly efficient and economical steam driven high speed compressor plant must be installed so as to get the maximum power out of coal. The boiler room will contain two 250-H. P. water-tube boilers with automatic stokers and coal bin overhead holding two weeks' supply of coal. Steam pressure 175 lbs. As the firing of the boilers is automatic and requires practically no work on the part of the engineers, no firemen are needed. Ashes will also be removed automatically. The engine room equipment will consist of two 175-ton high speed compressors, direct connected to two Simple Condensing Una-flow Engines; also two generators, two cooling tower water pumps, two air compressors, switchboard, etc. All to be equipped with the latest labor and power-saving devices. Equipped as above, 25 tons of refrigeration can be easily obtained from one ton of ordinary 12,500 B T U coal. 1.8 ton of refrigeration is required to produce one ton of ice including the required cooling of storage house. Therefore the power cost of making one ton of ice with coal at $5.00 per ton equals $5.00 divided by 25/1.8 = 37 cent. (One cent per ton of ice is added for heating of dipping tank water.) Assuming one month's shut-down for inspection and repairs, the total output of 160 tons of ice for 333 days amounts to 53,280 tons of ice. The total power cost of making 53,280 tons of ice is therefore, 53,280 x 37 cent = $ 19,713.60 [10] ENGINE ROOM AND ICE PLANT LABOR COST: 1 chief engineer per day $ 8.00 3 engineers per day $ 6.00 1 shipping clerk per day $ 6.00 3 men in Storage House per day $ 4.00 Total per day $ 44.00 365 days at $44.00 per day equals $ 16,060.00 Additional labor cost for putting 12,000 tons into winter storage and taking out at $4.00 per day $ 1,200.00 Total Labor Cost $ 17,260.00 or 17260 / 53280 = 32.4 cent per ton Engineers will do their own firing of boilers and will pull all the ice. One pull required every 43 minutes. OFFICE EXPENSE: 1 Office Man (Manager and Bookkeeper) $ 3,000.00 Stationery, Telephone, etc. (per year) $ 300.00 Total Office Expense $ 3,300.00 or 3300 / 53280 = 6.2 cent per ton of ice Cost of Ammonia at 2 cent per ton $ 1,065.60 Cost of Oil and Waste at 2 cent per ton $ 1,065.60 Cost of Water at 3 cent per ton $ 1,598.40 Cost of Salt at 1/2 cent per ton $ 266.40 Plant Maintenance and Repairs $ 2,200.00 or 2200 / 53280 = 4.1 cent per ton [11] OVERHEAD CHARGES: 8 per cent interest on $220,000.00 investment equals $ 17,600.00 8 per cent interest on value of land ($10,000.00) $ 800.00 8 per cent interest on working capital ($7,500.00) $ 600.00 3 per cent depreciation on $220,000.00 $ 6,600.00 Insurance (estimated) $ 1,000.00 Taxes (estimated) $ 2,000.00 Total overhead charges $ 28,600.00 or 28600 / 53280 = 53.7 cent per ton Total Expense $ 75,069.60 or 75069.60 / 53280 = $ 1.409 per ton Divided as follows: Overhead charges $ 0.53.7 Manufacturing Cost (total) $ 0.87.2 [12] NUMBER FOUR Manufacturing Costs Per Ton of Ice Using Steam Power at Medium-Sized-Town Rates for Labor 100-ton capacity per day. 1,080--400-lb. cans. 333 days continuous full output. 7,600-ton Storage House. COST OF POWER: A modern, highly efficient and economical steam driven high speed compressor plant must be installed so as to get the maximum power out of coal. The boiler-room will contain two 200-H. P. water-tube boilers with automatic stokers and coal bin overhead holding two weeks' supply of coal. Steam pressure 175 lbs. As the firing of the boilers is automatic and requires practically no work on the part of the engineers, no firemen will be needed. Ashes will also be automatically removed. The engine room equipment will consist of two 100-ton high speed compressors, direct connected to two Simple Condensing Unaflow Engines; also two generators, two cooling tower pumps, two air compressors, switchboard, etc. All to be equipped with the latest labor and power-saving devices. Equipped as above, 25 tons of refrigeration can be easily obtained from one ton of ordinary 12500 B T U coal. 1.8 tons of refrigeration is required to produce one ton of ice, including the cooling of the storage house. Therefore, the power cost of making one ton of ice with coal at $5.00 per ton equals $5.00 divided by 25/1.8 = 37 cent. (One cent per ton of ice is added for heating of dipping-tank water.) Assuming one month's shut down for inspection and repairs, the total output of 100 tons of ice for 333 days amounts to 33,300 tons of ice. The total power cost of making 33,300 tons of ice is therefore, 33,300 x 37 cent, equals $ 12,321.00 [13] ENGINE ROOM AND ICE PLANT LABOR COST: 1 Chief Engineer per day $ 8.00 3 Engineers per day $ 6.00 2 Storage House Men per day $ 4.00 Total per day $ 34.00 Total 365 days at $34.00 per day $ 12,410.00 Additional labor cost for putting 7,500 tons into winter storage and taking out at $4.00 per day $ 750.00 Total labor cost $ 13,160.00 or 13160 / 33300 = 39.52 cent per ton Engineer will do his own firing of boilers and will pull all the ice and set it up in ante room if required. One pull required every 70 minutes. Chief Engineer will act as shipping clerk. OFFICE EXPENSE: 1 Office Man (Manager and Bookkeeper) $ 3,000.00 Stationery, Telephone, etc. (per year) $ 300.00 Total Office Expense $ 3,300.00 or 3300 / 33300 = 9.9 cent per ton Cost of Ammonia at 2 cent per ton $ 666.00 Cost of Oil and Waste at 2 cent per ton $ 666.00 Cost of Water at 3 cent per ton $ 999.00 Cost of Salt at 1/2 cent per ton $ 166.50 Plant Maintenance and Repairs $ 1,500.00 or 1500 / 33300 = 4.5 cent per ton [14] OVERHEAD CHARGES: 8 per cent interest on $150,000.00 investment $ 12,000.00 8 per cent interest on value of land ($7,000.00) $ 560.00 8 per cent interest on $5,000.00 working capital $ 400.00 3 per cent depreciation on $150,000.00 $ 4,500.00 Insurance (estimated) $ 700.00 Taxes (estimated) $ 1,360.00 Total overhead charges $ 19,520.00 or 19520 / 33300 == 68.7 cent per ton Total Expense $ 52,298.50 or 52298.50 / 33300 = $1.57 per ton Divided as follows: Overhead charges 68.7 cent Manufacturing Cost 98.3 cent [15] OTTO LUHR CONSULTING ENGINEER & HERMAN FRIEDL ARCHITECT ICE MAKING SYSTEM 154 W. RANDOLPH STREET, CHICAGO [End of Document] [Transcriber's Note] I found this document and the attached papers and photographs among my father's papers. I offer it as an insight into the finances and structure of business and trades in the early 1900's. There are no dates included in this document but a Google search of "Otto Luhr" produced these items: Mechanical and Refrigerating Engineer's Handy Book; Otto Luhr; 1913. Automatic refrigerating liquid feeder and regulator; United States Patent 1725875; 8/27/1929. Refrigerator car; United States Patent 1642882; 9/20/1927. Since the title page states "Patent Applied For", this document was probably published around 1925. Note the prices quoted for materials and labor: Coal, $5.00 a ton. [In 2009, about $100/ton, down from $300 in 2008.] Unskilled Labor, $6.00/day; that's DAY, not HOUR. Skilled Labor, $8 to $10/day Electricity, $0.009/KWH [my latest bill (in 2009) was $0.1317/KWH] Note the job titles in the attached documents: Barnmen, Washers, Blacksmiths The word "MAINTAINANCE" is thus spelled in the original. Finally, the optimistic tone of the document contrasts with the decline of the ice business in the 1940's, fifteen years later. I remember the ice deliveries and the weight sign my mother put in the window before we got our first mechanical refrigerator after World War II. [End Transcriber's Note] [Illustration: Photograph of machinery.] [Illustration: Photograph of Detroit Creamery building exterior.] DETROIT CREAMERY COMPANY ORGANIZATION 1 -- Board of Directors 2 -- Operating Committee Harry A. McDonald President Nelson J. Dessert Vice president Carl F. Siclaff Vice president Harry J. Weigand Treasurer & Comptroller Jerome H. Remick Ice Cream Sales & Service J. Harry Brickley Retail Milk Sales Oliver G. Spaulding Legal Department Richard L. Baire Advertising Frank McVeigh Purchasing Department Ben F. Taylor Ice Cream Production Ben F. Taylor Ice Cream Delivery Edward C. Krahl Henry St. Production Doc Grayson Laboratory John Kostuch Plant Engineer--Maintenance John Kostuch Power & Refrigeration J. Harry Watson Transportation J. Harry Watson Shops H. Terry Snowday Wholesale Milk Sales Carl O. Tuttle Butter Department Tom Wood Credit & Collections J. McWilliams Detroit Creamery Farms TREASURER & COMPTROLLER Harry J. Weigand Accounting - Detroit Creamery & Subsidiaries Loans & Contracts - Detroit Creamery & Subsidiaries Appropriations - Detroit Creamery & Subsidiaries Banks - Detroit Creamery & Subsidiaries Account Dept Personnel - Detroit Creamery & Subsidiaries Credits & Collections Corporate Records Purchasing Department Legal Department PLANT ENGINEERING--MAINTAINANCE POWER and REFRIGERATION John Kostuch (Chief Engineer) Paul Culver (Consulting) Norman Mitehell (Technical) (Advisory) (Dept. Head) HENRY STREET (MAINTAINANCE) James Crunnley (In Charge) (a) Electrical & General (Ray Casson) (b) Conveyors, Bottle Washers, Fillers, Cappers (Howard Strauss) (c) All other Machinery (Assign Mechanics) HENRY STREET (POWER & REFRIGERATION) Harry Hollenbeck (In Charge) (a) Engineers (b) Firemen MAIN PLANT (MAINTAINANCE) (POWER & REFRIGERATION) John Kostuch (In Charge) REC. STATIONS & MFG. PLANTS John Kostuch (Chief) Elmer DeWitt(Asst) Frank Mortimer (Mech) C. S. McBride (Production Dept.) SUBSIDIARY COMPANIES John Kostuch (Chief) Paul Culver--Norman Mitchell--Dept. Head MACHINE SHOP (MAIN PLANT) John Kostuch (In Charge) TRANSPORTATION & SHOPS J. Harry Watson Garages Detroit Subs. (Advisory) Auto Shops Detroit (Met. Area) Subs. (Advisory) Paint Shops Detroit & Subs. Electrical Shops Detroit Subs. (Advisory) Carpenter Shops Detroit & Sub. (Advisory) Stables Detroit (Advisory) Barnmen Sub. (Advisory) Washers Blacksmiths Wagon Shops Detroit & Subs Harness Shops Detroit & Subs. Plumbing Shops Detroit Sign Shop Detroit & Subs. Tin Shop Detroit & Subs. Special Delivery and Trucking Detroit (Main) Branch Trucking Special Trucking 
20663	----	THE AMERICAN PRACTICAL BREWER AND TANNER: IN WHICH IS EXHIBITED THE WHOLE PROCESS OF Brewing without boiling. Brewing strong Beer with the extract only of the Hop, leaving out the substance. A simple method of giving new Beer all the qualities of age, thereby fitting it for the bottle before it is three weeks old. A simple method of preventing Beer bursting the bottle. An economical mode of constructing Vats above ground, possessing the temperature of the best cellars and thus rendered fireproof. An economical mode by which every Housekeeper may brew his own Beer. A method of brewing good Beer from Bran and Shorts, and of preserving it. The Bordeaux method of making and preparing Claret Wine for shipping, which may be successfully applied to the wines of this country, particularly those of Kaskaskias. The best method and season for malting Indian Corn, from which alone good Beer can be made, a process highly important to Brewers. The best mode of raising Hops. The best mode of preparing Seed Barley for sowing. Best construction and aspect of Breweries and Malt Houses in this country. The French mode of tanning the heaviest Soal Leather in twenty-one days, and Calf Skins in three or four. (Highly important.) BY JOSEPH COPPINGER. Practical Brewer. _NEW-YORK_: PRINTED BY VAN WINKLE AND WILEY, No. 3 Wall Street. 1815. Transcriber's Note: Part of the last sentence in Footnote 6 is illegible and has been marked [remainder of text is illegible]. In addition, the Contents were moved from the rear to the front of this text for the convenience of the reader. CONTENTS. Page. Advertisement 3 Preface 5 The best position for placing a brewery and malt house, also the best aspect, with different arrangements of the vessels 11 A description of the form and plan of a brewery, distribution of the vessels; the most judicious and convenient manner of placing them, with a view to economy, cleanliness, and effect 13 Malt house, the best construction of, with proper barley lofts, dropping room, and flooring, how, and in what manner made, and best likely to last 18 Wooden kilns, how constructed 23 A new and economical construction of vats for keeping beer, which, in this way, may be rendered fire proof, whilst at the same time possessing the temperature of the best cellars, although above ground 29 Grinding, how substituted for 31 Malting 33 Plain practical process of malting 44 Malting winter barley 50 Malting oats ib. Malting rye ib. Malting wheat ib. Indian corn, how malted 51 Fermentation 54 Hops, how cultivated 99 Barley cultivation 109 Table beer 112 Small beer for shipping 113 Keeping table beer 114 Small beer of the best kind 116 Another method to brew small beer 118 Another process for brewing small beer 120 Single ale and table beer 123 Strong beer 126 Table beer, English method of brewing it 129 Unboiled beer 131 Strong beer, brewed with the extract of hops, leaving out the substance 134 Table beer for housekeepers, well worth their attention 136 Fermenting and cleansing in the same vessel 138 Plate of the worker 139 A new method of fermenting strong beer, that will produce a pure and good liquor 140 Process of brewing Windsor ale, on a small scale 142 Reading beer, how brewed 145 Two-penny amber beer, as brewed in London 147 London ale, how brewed 149 Windsor ale, on a large scale 151 Welsh ale, how brewed 154 Wirtemberg ale 156 Hock 158 Scurvy grass ale 160 Dorchester ale 162 Porter 165 Porter process No. I. 167 Porter process No. II. 170 Porter process No. III. 172 Porter malt 174 Porter colouring 176 Strong beer 182 Filtering operation (with a Plate) 189 Returned beer, how to make the most of 193 To Bring several sorts of beer, when mixed, to one uniform taste 194 Finings, the best method of preparing them 195 Heading 197 Bottling beer 198 Brewing coppers, the best method of setting them 202 Pumps, the best construction of, and how freed from ice in winter 205 Cleansing casks 208 To make mead wine 210 To make ginger wine 212 To make currant wine 213 Yest, how prepared to keep good in any climate 214 To make a substitute for brewer's yest 217 Another method 218 Another method 220 Process of making and preparing claret wine for shipping, as practiced in Bordeaux and its neighbourhood 221 Brewing company 227 The author's notice about plans and sections of elevation for breweries and malt houses 230 French mode of tanning 232 _Errata._ In the Advertisement, 4th page, 6th line, first word, for _wine_ read _vine_; and in the next line, first word, for _it_ read _its produce_. In page 25, 25th line, the last word should be omitted, and read thus, _malt or grain intended to be dried on it, requiring less fuel_, &c. In page 36, 25th line, first word, for _proportion_ read _preparation_. SOUTHERN DISTRICT OF NEW-YORK, _ss._ BE IT REMEMBERED, that on the fourteenth day of September, in the fortieth year of the independence of the United States of America, Joseph Coppinger of the said district, has deposited in this office the title of a book, the right whereof he claims as proprietor, in the words and figures following, to wit: "The American Practical Brewer and Tanner: in which is exhibited the whole process of Brewing without boiling; Brewing Strong Beer with the extract only of the Hop, leaving out the substance; a simple method of giving new Beer all the qualities of age, thereby rendering it fit for the Bottle before it is three weeks old; a simple method of preventing Beer bursting the Bottle; an economical mode of constructing Vats above ground, possessing the temperature of the best Cellars, and thus rendered fireproof; an economical mode by which every Housekeeper may brew his own Beer; a method of brewing good Beer from Bran and Shorts, and of preserving it; the Bordeaux method of making and preparing Claret Wine for shipping, which may be successfully applied to the vines of this country, particularly those of Kaskaskias; the best method and season for malting Indian Corn, from which alone good Beer can be made, a process highly important to Brewers; the best mode of raising Hops; the best mode of preparing Seed Barley for sowing; best construction of Breweries and Malt Houses in this country; the French mode of tanning the heaviest Soal Leather in twenty-one days, and Calf Skins in three or four--highly important. By Joseph Coppinger, Practical Brewer." In conformity to the act of the Congress of the United States, entitled "An act for the encouragement of learning, by securing the copies of maps, charts, and books to the authors and proprietors of such copies, during the times therein mentioned;" and also to an act entitled "an act, supplementary to an act, entitled an act for the encouragement of learning, by securing the copies of maps, charts, and books, to the authors and proprietors of such copies, during the times therein mentioned, and extending the benefits thereof to the arts of designing, engraving, and etching historical and other prints." THERON RUDD, Clerk of the Southern District of New-York. ADVERTISEMENT. Since writing the Preface, I have been induced to make an addition to this little work, in order to increase its usefulness, by giving the French mode of tanning, as practised by the famous Mr. Seguine. Of such importance did the Academy of Arts and Sciences at Paris consider this improvement, that they thought it worth while to appoint a committee of their own members to go down to one of the provinces where this gentleman resides, and there, on the spot, superintend his operations, which they did with minute attention; and it is from the journal of their reports to the academy, that the different processes of tanning leather in this ingenious artist's way are here given; an improvement that can, no doubt, be successfully applied to that important manufacture in this country, affording the tanner the opportunity of turning his capital twelve or fourteen times in a year, instead of once. This single advantage alone so forcibly recommends its adoption, particularly in a country like ours, where capital is scarce, that further comment is unnecessary. I have also added the Bordeaux method of making and preparing claret wine for shipping, as practised in that city and its vicinity; which practice may possibly hereafter be successfully applied to the red wines of this country. The more so, when it is known that in the reign of Louis XVI., the merchants of Bordeaux presented a memorial to that monarch, praying him to put a stop to the importation of the wines of Kaskaskias into France, as likely, if permitted, to be injurious to the trade of Bordeaux. There was at that time a College of Jesuits established in that country, the superiors of which caused the wine to be cultivated with great success, and quantities of it were at that time sent to France. As that territory is now in our possession, and its soil and climate peculiarly favourable to the growth of the grape, which is indigenous there, may it not be an object well worth the attention of our government, to encourage and improve the growth of the wine in that section of the union; which wise measure would, probably, in a few years, supply our own consumption, and leave a considerable surplus for exportation. To offer an apology for giving these subjects a place in this publication, seems wholly unnecessary, when their importance is considered. PREFACE. Brewing, in every country, whose soil and climate are congenial to the production of the raw materials, should be ranked among the first objects of its domestic and political economy. If any person doubt the truth of this position, I have only to request him to cast an eye on England, where the brewing capital is estimated at more than fifteen millions sterling; and the gross annual revenue, arising from this capital, at seven million five hundred thousand pounds sterling, including the hop, malt, and extract duties. Notwithstanding this enormous excise of 50 per cent. on the brewing capital, what immense fortunes have been made, and are daily making, in that country, as well as in Ireland and Scotland, by the intelligent and judicious practice of this _more than useful art_. Yet how much stronger inducements for similar establishments in this country, where we have no duty on the raw materials, or the extract;[1] and where the important article of hops is raised in as high perfection as in any part of Europe, and often for one third of the price paid in England. But a still more important consideration is the health and morals of our population, which appears to be essentially connected with the progress of the brewing trade. In proof of this assertion, I will beg leave to state a well known fact; which is, that in proportion as the consumption of malt liquors have increased in our large towns and cities, in that proportion has the health of our fellow citizens improved, and epidemics and intermittents, become less frequent. The same observation holds good as respects the country, where it is well known that those families that brew their own beer, and make a free use of it through the summer are, in general, all healthy, and preserve their colour; whilst their less fortunate neighbours, who do not use beer at all, are devoured by fevers and intermittents. These facts will be less doubted, when it is known that yest, properly administered, has been found singularly successful in the cure of fevers. This the practice of the Rev. Doctor Townsend, in England, places beyond all doubt, where he states, that in fifty fever cases that occurred in his own parish, (some of which were of the most malignant kind,) he only missed a cure in two or three, by administering yest. Having considered the produce of the brewery as it is connected with health, we may, with equal propriety, say it is not less so with morals; and its encouragement and extension, as an object of great national importance, cannot be too strongly recommended, as the most natural and effectual remedy to the too great use of ardent spirits, the baneful effects of which are too generally known, and too extensively felt, to need any particular description here. The farmer and the merchant will alike find their account in encouraging and improving the produce of the brewery. The farmer can raise no crop that will pay him better than hops; as, under proper management, he may reasonably expect to clear, of a good year, one hundred dollars per acre. Barley will also prove a good crop, if proper attention be paid to seed, soil, and time of sowing. The merchant will alike find his account in encouraging the brewery, from the many advantages derivable from an extensive export of its produce to the East and West Indies, South America, the Brazils, but particularly to Russia, where good beer is in great demand; large quantities are annually sent there from England, at a much higher rate, it may be presumed, than we could afford to supply them from this country. All these considerations united seem forcibly to recommend giving the breweries of the United States every possible encouragement and extension. Here, it is but justice to state, that the brewers of New-York deserve much credit for the high improvement they have made in the quality of their malt liquors within a few years, which seem to justify the hope that they will continue these advances to excellence, until they realise the opinion of Combrune and others, that it is possible to produce a "_malt wine_." [1] Save five per cent. on brewery sales--a war tax. [Illustration: A Malt House. B Kiln. C Dropping Room. D Mill House. E Brewery. F Working Store. G Vat House and Dry Store. H Bed Room. I Office. K Dwelling House. L Hop Room. M Stable. N Brewing Yard. O Cooper's Shed. P Steep.] THE AMERICAN PRACTICAL BREWER AND TANNER _The best position for placing a Brewery and Malt house, also the best aspect, with different arrangements of the Utensils._ Cleanliness being as essential in the brewery as in the dairy, it is of the greatest importance, never to lose sight of it in every part of the operations, and particularly in selecting the ground and soil to place a brewery on. The situation to be preferred should be an elevated one, and the soil either sand or gravel, as it is of great importance in the preservation of beer that the cellars be dry and sufficiently ventilated by windows properly disposed. If the cellars of the brewery be under ground, it would be very desirable to have them kept sweet and clean by properly constructed sewers, without which, pumping by a hand or a horse power is a poor substitute, as by this means (which we find too common in breweries) the washings of the cellars have time to become putrid, particularly in summer, emitting the most offensive and unwholesome effluvia, contaminating the atmosphere, and frequently endangering both the health and lives of the workmen. This is a serious evil, and should in all cases, as much as possible, be avoided. It is true, there are times, when a choice of situation cannot be made; in that case, circumstances must be submitted to, and people do the best they can. The cellars and coolers of the breweries in this country should have a northern aspect, and the cellars principally ventilated from east to west. The windows on the south side of cellars should be always close shut in summer, and only occasionally opened in winter; the floors of cellars should be paved with either tile or brick, these being more susceptible of being kept clean than either pavement or flags, and not so subject to get out of order. Supposing the brewery to have all its cellars above ground, which I conceive to be not only practicable, but, in many cases, preferable to having them under, as more economical, and more cleanly, particularly where vats for keeping strong beer are constructed on the plan herein after recommended, in which it is expected the temperature necessary for keeping beer will be as securely preserved above, as under ground, and the erections so constructed, as not only to be air, but fire proof. (See description of these vats.) _A description of the form and plan of a Brewery, distribution of the Vessels, the most judicious and convenient manner of placing them, with a view to economy, cleanliness, and effect._ The best plan of a well-constructed brewery I conceive to be that of a hollow, or oblong square, where all is enclosed by one or two gateways, (the latter the most complete,) parallel to each other. The first gateway, forming the brewery entrance, to pass through the dwelling house; the second, or corresponding gateway, to pass through the opposite side of the square, into an outer yard, well enclosed with walls and sheds, containing cooper's shop, &c. where all the empty casks might be securely preserved from the injury of wind and weather. This yard should be further sufficiently large to afford room for a hay reek, firewood, dung, &c. The brewery office should be placed in the passage of the outer gateway, so that every thing going in and out might be seen by those who are in the office. The dwelling house, vat house, and working store, to form one side of the brewery. The malt house, another. The kiln house, dropping room, and stable, a third side. The brewery, mill house, and hop room, to form the fourth side; thus completed, it would form a square, and afford security to whatever was contained within it, when the gates are locked. The sky cooler is, generally, the most elevated vessel in the brewery, and when properly constructed, is of great importance in facilitating both brewing and malting operations, as it usually supplies the whole quantity of water wanted in both. It commands the copper, and, of course, all the other vessels of the brewery: it may be so constructed as to form a complete roof to the mill loft, and in that situation be most conveniently placed for being filled from the water cistern, which should be placed contiguous to the mill walk, and so raised to the sky cooler by one or more pumps worked by the mill, with a one, two, or three horse power, according to the length of the lever, and the diameter of the mill. Sky, or water coolers, in general, are square vessels, made of the best two inch pine plank, properly jointed, from twenty to twenty-five feet square, laid on strong joists sufficiently close, and trunneled down (after pressing) with wooden trunnels from end to end, to prevent starting or warping; the joists are supported by a couple of strong beams, equally spaced; the sides of these coolers are generally raised from eighteen inches to two feet; in Europe they are generally leaded on their inside, but this expense may be saved, if they are properly made at first, and afterwards kept constantly full of water. In constructing these coolers, all the joints should be paid with white paint before laying, and the sides bolted, and screwed down; the better and easier to effect which, the thickness of the sides may be three inches after the saw; there should be a roofing all round the sides, to protect them from the weather; the bottom of the sky cooler should command the copper back, which should be made to form the cover of the copper, and to hold a complete charge of the same. These vessels, when properly constructed, are extremely useful in preventing waste and accidents by boiling over, also affording to the brewer, the opportunity of boiling his wort as fiercely as he pleases--a very important advantage in brewing porter and strong beer. A description of this back is not necessary, as every set cooper, who knows his business, is well acquainted with the proper construction of this vessel. The stuff it is made of should be two inches thick, well seasoned, and of the best pine plank. Thus placed on the copper, it should form a complete cover, water and steam tight, so that when the copper boils over, it will run into the back, and return again by a plug hole into the copper. The copper cock should be sufficiently elevated to command the hop cooler; the latter the wort coolers, No. 1 and 2. By thus running the worts from one cooler to another, you afford them the opportunity of depositing in each their feculencies, and coming nearly fine to the fermenting tuns, which should be sufficiently elevated above the troughs and casks to be filled, so that the operation of cleansing may be easily performed by one or more leaders, to communicate with a two or three piped tun dish, capable of filling two or three casks at a time. The mill stones, or metal rollers, should be sufficiently elevated to grind into the malt bin, placed over the mash tun, which bin should be sufficiently capacious to hold the whole grist of malt when ground; this bin is generally constructed in the form of a hopper, with a slide at the bottom, to let the malt into the mash tun when the water is ready, by being cooled down to its proper temperature. I would recommend making the mash tun shallow, so that the diameter shall be three times as long as the staff of the sides, above the false bottom. To the mash tun there should be a cover, in two or more pieces, according to size. The receiver, or underbank, which is placed under the mash tun, should be sufficiently elevated above ground, so as to enable the dirty or washing water to run off from its bottom by a plug hole. The fermenting tuns should be placed in a room where there is a fireplace, so as to raise the temperature in cold weather; each tun should be cribbed on its sides, with a stationary cover on the top. The cribs should be made to answer the sweep of the vessel, and to be put on or off as occasion, or the temperature of the season, may require. In one corner of the working store, I would recommend to have placed a set of drains, two in number, one over the other; the lower drain should be sufficiently elevated to get a bucket under it, so as to draw off its contents by a plug hole, placed at one corner of each drain. These drains will soon pay for themselves, by the quantity of yest that will be deposited on them, at each time of drawing them off, while the liquor will get fine, and may be applied in a variety of ways, to answer the purposes of the brewer, what in filling, starting in the tun, vatting, &c. _Malt House, the best construction of, with proper Barley Lofts, Dropping Room, and Flooring, how, and in what manner made, and best likely to last._ Malt houses intended to be annexed to breweries, should not be on a less scale than sixty feet long, by twenty-five feet wide. Unless there be a proper proportion of flooring to work the grain kindly and moderately, good malt is not to be expected. Two-floored houses are generally preferred to any other construction; would recommend placing the steep outside the house, to be communicated with from the lower floor by means of an arch way or window; the steep so placed should be covered with a tight roof; the best materials for making a steep are good brick, well grouted; the wall should be fourteen inches thick at least; this kind of steep will be found far superior to wood, as not liable to leak, or be worked on by rats; the sides and ends of this steep should be carefully plastered with tarrass mortar; the bottom may be laid with flag, tiles, or brick.[2] Two barley lofts, the whole length of the malt house, will be found highly convenient, as affording sufficient room to different large parcels of barley, and screening the same from loft to loft as it descends into the steep over wire screens; a contrivance I have found of great advantage in the malting operation, as finishing the cleaning of the barley before getting into the steep, a precaution that should never be omitted. The bottom of the screen should be cased with wood, communicating from loft to loft with a sack fastened to hooks at the lower end to receive all the dirt and screenings that may pass through the screens. The Dutch and German maltsters generally prefer having their lower or working floor under ground; but this I take to be a bad plan, unless in elevated situations, or where the soil is dry and gravelly; for if any spring of water or damp arises in the malt-house floor, or walls so placed, the injury to the malt is very great, and should be carefully guarded against. It is also very important to lay a solid foundation for your lower floor with stones, brick bats, or coarse gravel, which should be solidly compacted by ramming for the whole length, then levelled off by stakes, with a ten-foot level, to the thickness you would wish to give your floor--say three or four inches: the former thickness, say three inches, will be found sufficient. Lay your first coat on two inches thick with hair mortar; when this coat becomes sufficiently stiff, which will happen within twenty-four hours, you are to begin to lay your second or last coat of one inch thick over the first, to be prepared as follows: Take Roche, or unslaked lime, one part, by measure; fine pit sand, one part; clinker, or forge dust, finely powdered, two parts; clay or lome, by measure also, one part: let these different ingredients (taking the precaution of first slaking the Roche lime) be well mixed together, and then screened by a wire screen, carefully keeping out of the mixture all lumps and stones; the whole may be then worked up with a due proportion of water, observing that this kind of mortar cannot be too much worked or mixed together, nor too little wetted, just sufficient to work freely with the plastering trowel; the whole floor should, if possible, be laid in one day, and for this purpose several hands should be employed; in which case it will dry more equally and firmly. As soon as the floor begins to set, and that it will bear a board on it, without sinking in, you should begin to pound it in all directions, from end to end, with pounders made of two-inch plank, sixteen inches long, and from nine to twelve inches wide, with a long handle reaching breast high, and to be placed in the middle of this board; thus the operation of pounding will proceed without stooping or much labour. One or two men, with plastering trowels, should follow the pounders, wetting it with skimmed milk as they go, and set the floor as even and close as possible. If these two operations be well conducted there will not be found a single crack in the whole floor from end to end, which is of great importance to secure the making of good malt. Each loft should have uprights under the centre of all the beams from end to end of the house; this precaution is necessary to prevent the swagging or cracking of the upper floor. Trap doors should be placed at proper distances in the upper malt-house floor, to facilitate the shovelling of the couches from the lower to the upper floor. A well constructed kiln is of great importance to insure a successful result to the malting operation, and if large enough to dry off each steep at _one cast_ so much the better. The most approved covering for malt kilns in England (although not the most economical) is hair cloth, as it is asserted, it dries the palest and sweetest malt. Many prefer tiles, as less expensive and more lasting; others dry on boarded floors, and if this construction be well managed, I take it to be as good as any, and much cheaper than either tiles or hair cloth. (See description page 23.) The dropping room for receiving the malt as it comes off the kiln may be constructed different ways; but I take it that a ground floor covered with a two inch plank well jointed, and properly laid, is preferable to a loft for keeping malt, and in this situation might be heaped to any depth without injury or danger of breaking down. Malt thus kept, if well dried before coming off the kiln, is never in danger of heating or getting slack. The common mode of keeping malt is in bins situated on upper lofts, often injured by leaks from the roof, and at all times liable to the depredations of rats, which in the other way can be effectually guarded against, and is a highly important object of precaution to be taken by the brewer. Should weevils at any time get into, or generate in your malt, which is common when held over beyond twelve or eighteen months, the simplest and easiest way of getting rid of them, is to place four or five lobsters on your heap of malt, the smell of which will soon compel the weevils to quit the malt, and take refuge on the walls, from which they can be swept with a broom into a sheet or table cloth laid on the malt, and so taken off. It is asserted, that by this simple contrivance not one weevil will remain in the heap. Malt intended for brewing should be always screened before grinding; and for this purpose it is a good contrivance to screen it by means of the horse mill, as it runs from the hopper to the rollers or stones to be ground, the expense of which apparatus is comparatively nothing when compared to the advantages arising from it. [2] By some this construction of a steep may be thought too dear; in that case, a rough wooden one may be substituted, which, instead of placing outside the house, I would place on the upper floor of the malt house, so as to afford the opportunity of getting down its contents to the lower floor by means of a plug hole, which will save the labour of shovelling; but in summer, when this steep is not employed, it should be filled with lime water to prevent leaking, and to keep it sweet. _Wooden Kilns, how constructed._ The best form for these kilns is the circular. I will suppose the diameter sixteen feet; you construct your fire-place suitably to the burning of wood at about ten feet outside your kiln house, sufficiently elevated on iron bars to secure the draft of the fire place, from which runs a proportionate sized flue into the kiln, communicating with a circular flue which is close covered at top, and rounds the kiln on the inside at the distance of two feet from the wall; on both sides of this circular flue holes are left, at the distance of twelve or sixteen inches apart, on both sides, to let out the smoke and heat; the platform or floor of this kiln is raised about four or five feet above the top of the flue, and is made of three quarter inch boards, tongued and grooved, supported by joists two inches broad, and nine inches deep, placed at proportioned distances, to give solidity to the floor. The floor or platform of this kiln should be carefully laid, and well nailed; in this floor should be placed a wooden chimney, nine inches square, on the most convenient part of the inside next the wall, with a wooden register at a convenient distance: this chimney is intended to let off the great smoke that arises in the kiln at first lighting fire, particularly if the wood be moist or green. When this has gone off, and the fire burns clear, the register may be shut within a few inches, in order to keep up a small draft. It would have been proper to state that joists, intended to support the floor of this kiln, should be levelled off to one inch, top and bottom, so as give the fire a better chance to act upon the malt; these joists should be further paid as soon as, or before, laying down, with a strong solution of alum water; as also the bottom face of the boards laid on them, which should be first planed; the inside of the chimney and register should be also paid with the alum solution. On the top of the kiln should be placed a ventilator to draw off the steam of the malt, this may be done by means of a loover or cow; the latter turns with the wind, the former is stationary. There should be skirting boards, nine inches deep, to lie close to the floor and walls of the kiln, plastered with hair mortar on the top. This construction of kiln has been introduced by the Dutch, and will be found the most economical of any, joined to the peculiar advantage of being capable of drying malt with any kind of fuel, without danger of communicating any sort of bad flavour to the grain, while the heat can be securely raised to 120 degrees without any danger of ignition or burning; a higher heat is not wanted to dry pale malt. Of this, however, I have some doubts, as wood is a non-conductor of heat, and possibly is not susceptible of transmitting such a heat to the malt without danger of ignition. I should think that thin metal plates, one foot square, cast so as to lap on each other, or tiles, of the same make or form, would be a better covering; they certainly would convey the heat more rapidly and securely to the malt or grain intended to be dried on it, never requiring less fuel than the wooden covering, and precluding all danger of fire. [Illustration: A A A A A ground section of the vats. B the section of elevation.] _A new and economical construction of Vats for keeping Beer, which, in this way, may be rendered fire proof, whilst, at the same time, it secures a temperature for the liquor equal, it is expected to the best vaults: it further affords the convenience of having them above ground._ These vats may be constructed in different forms, either square, oval, or round; the latter I should prefer, as stronger, and less liable to leak. These circular vats, to save expense, may be bound with wood hoops instead of iron ones the splay to be given them as little as possible barely sufficient to have the hoops tight, and the vessel staunch. The bottoms of these vats should be elevated at least three and a half, or four feet from the ground, and solidly bedded in clay, earth, or sand; the clay, if convenient, to be preferred. As the earth rises, at every five or six inches, around these vats, it should be firmly pounded down and compressed, as in the case of tanners' vats; and this mode of surrounding the vats with dry earth well pounded and rammed is continued to the top; a stout, close, well-fitted cover of two inch plank is then placed on each vat, with a hole sixteen inches square, to let a man down occasionally; this hole should have a short trunk of an inch and a half plank firmly nailed to its sides, and about fourteen inches high; then a covering of earth, twelve inches deep, should be placed all over the tops of these vats, and this earth well rammed and compacted together; and when levelled off, covered with composition or a floor of tiles. Each of the trap doors should have a well-fitted, wooden cover on the top, with a ring of iron in the centre; this cover should be made fire proof on the outside. The brick wall in front of these vats need not, I apprehend, exceed fourteen inches thick, if of brick, just sufficient to resist the force of pressure from ramming the clay; vats thus placed, with their contents, may be considered fire proof, and possessing as cool a temperature as if placed fifteen feet under ground; joined to this, they will last six times as long as those in cellars or vaults, although bound in iron, at a considerable higher expense. Two ranges of these vats may be placed in one house, leaving a sufficient space for a passage in the centre, with a window at each end to light it. I have never before either heard or read of this construction; but I have little hesitation in saying it will in many cases be found preferable to the present mode of placing vats--it being more convenient, cleanly, economical, and secure, and, to all intents and purposes, as effectual in point of temperature as those expensively placed deep under ground. Under the inside of the head of these vats, and across the joints, should run a piece of scantling six inches wide, and four inches deep, with an upright of the same dimensions in the centre, in order to support the covering on the head, and to prevent sinking, or swagging, from the weight of the covering that will be necessarily placed over them, which will be from six to ten inches thick. _Grinding, how substituted for._ Malt, for brewing, may be prepared in three different ways, by grinding, bruising, or pounding; modern practice, however, almost universally gives the preference to bruising between metal rollers. This preference, where malt is of the very first quality, may be justified; but where it is of an inferior quality, which is but too generally the case, grinding with stones is preferable, as more capable of producing a fine grist, which, with indifferent malt, is important, as it will always produce a richer extract, by being finely, rather than coarsely ground; and it is more soluble in water of suitable temperature than that malt which is only bruised or cracked, and for this simple reason, that all imperfect-made malt has a great proportion of its bulk unmalted, and, of course, in a crude hard state, which will partially dissolve in water if ground fine, but will not dissolve at all if only cracked or bruised. A further object of the brewer's attention should be to prevent the dispersion, or waste, of the finer parts of the malt, so apt to fly off in the grinding, if not prevented by having the malt bin close covered, as well as the spout leading into it from the stones; trifling as this precaution may seem, it is well worth the brewer's attention. Here it may not be improper to observe, that in all cases of horse, or cattle mills, where the shaft of the main wheel is perpendicular, no better ingredient can be placed in the chamber of the lower box than quick silver, which is far superior to oil or grease, and will not require renewing for a long time. The brass of a mill, managed in this way, might be expected to last twenty years, and the movement smoother and easier. This economical substitute for oil and grease can, with equal advantage, be applied to water mills, whether their shafts be horizontal or perpendicular; in a word, to all kinds of machinery, where the preservation of the gudgeons and brasses are an object. _Malting._ The production of good malt is, without question, the key-stone of the arch of brewing; therefore the brewer's attention should be invariably directed to this point, as the most difficult and important part of his operations. The process of making malt is an artificial or forced vegetation, in which, the nearer we approach nature in her ordinary progress, the more certainly shall we arrive at the perfection of which the subject is capable. The farmer prefers a dry season to sow his small grain, that the common moisture of the earth may but gently insinuate itself into the pores of the grain, and thence gradually dispose it for the reception of the future shower, and the action of vegetation. The maltster cannot proceed by such slow degrees, but makes an immersion in water a substitute for the moisture of the earth, where a few hours infusion is equal to many days employed in the ordinary course of vegetation, and the grain is accordingly removed as soon as it appears fully saturated, lest a solution, and, consequently, a destruction of some of its parts should be the effect of a longer continuance in water, instead of that separation, which is begun by the introduction of watery particles into the body. Were it to be spread thin after this removal, it would become dry, and no vegetation would ensue; but being thrown into the couch, a kind of vegetative fermentation commences, which generates heat, and produces the first appearance of a vegetation. This state of the barley is nearly the same with that of many days continuance in the earth after sowing, but being in so large a body, it requires occasionally to be turned over and spread thinner; the former, to give the outward parts of the heap their share of the acquired warmth and moisture, both of which are lessened by exposure to the air; the latter, to prevent the progress of the vegetative to the putrefactive fermentation, which would be the consequence of suffering it to proceed beyond a certain degree. To supply the moisture thus continually decreasing by evaporation and consumption, an occasional, but sparing, sprinkling of water should be given to the floor, to recruit the languishing powers of vegetation, and imitate the shower upon the cornfield; but this should not be too often repeated; for, as in the field, too much rain, and too little sun, produces rank stems and thin ears, so here would too much water, and, of course, too little dry warmth, accelerate the growth of the malt, so as to occasion the extraction and loss of such of its valuable parts as, by a slower process, would have been duly separated and left behind. By the slow mode of conducting vegetation here recommended, an actual and minute separation of the parts takes place; the germination of the radicles and acrospire carries off the cohesive properties of the barley, thereby contributing to the preparation of the saccharine matter, which it has no tendency to extract, or otherwise injure, but to increase and meliorate, so long as the acrospire is confined within the husk; and by as much as it is wanting of the end of the grain, by so much does the malt fall short of perfection; and in proportion as it is advanced beyond, is that purpose defeated. This is very evident to the most common observation, on examining a kernel of malt, in the different stages of its progress. When the acrospire has shot but half the length of the grain, the lower part only is converted into that mellow saccharine flour we are solicitous of, whilst the other half exhibits no other signs of it than the whole kernel did at its first germination: let it advance to two thirds of the length, and the lower end will not only have increased its saccharine flavour, but will have proportionably extended its bulk, so as to have left one third part unmalted. This, or even less than this, is contended for by many maltsters, as a sufficient advance of the acrospire, which, they say, has done its business, so soon as it has passed the middle of the kernel. But we need seek no further for their conviction of error, than the examination here alluded to. Let the kernel be slit down the middle, and tasted at either end whilst green, or let the effects of mastication be tried when it is dried off; when the former will be found to exhibit the appearances just mentioned, the latter to discover the unwrought parts of the grain, in a stony hardness, which has no other effect in the mash tun, than that of imbibing a large proportion of the liquor, and contributing to the retention of those saccharine parts of the malt which are in contact with it; whence it is a rational inference, that three bushels of malt, imperfect in their proportion, are equal but to two of that which is carried to its utmost perfection. By this is meant the farthest advance of the acrospire, when it is just bursting from its confinement, before it has effected its enlargement. The kernel is then uniform in its internal appearance, and of a rich sweetness, in flavour equal to any thing we can conceive obtainable from imperfect vegetation. If the acrospire be suffered to proceed, the mealy substance melts into a liquid sweet, which soon passes into the blade, and leaves the husk entirely exhausted. The sweet thus produced by the infant efforts of vegetation, and lost by its more powerful action, revives, and makes a second appearance in the stem, but is then too much dispersed and altered in its form to answer any of the known purposes of art. The periods of its perfect appearance are in both cases remarkably critical. It is at first perfect at the instant the kernel is going to send forth the acrospire, and form itself into the future blade; it is again discovered perfect when the ear is labouring at its extrication, and hastening the production of the yet unformed kernels; in this it appears, the medium of nature's chemistry, equally employed by her in her mutation of the kernel into the blade, and her formation thus of other kernels, by which she effects the completion of that circle to which the operations of the vegetable world are limited. Were we to inquire by what means the same barley, with the same treatment, produces unequal portions of the saccharine matter in different situations, we should perhaps find it principally owing to the different qualities of the water used in malting, some of which are so much better suited to the quality of the grain than others, that the difference is truly astonishing. Hard water is very unfit for every purpose of vegetation, and soft will vary its effects according to the predominating quality of its impregnations. Pure elementary water is in itself supposed to be only the vehicle of the nutriment of plants, entering at the capillary tubes of the roots rising into the body, and here depositing its acquired virtues, perspiring by innumerable fine pores at the surface, and thence evaporating by the purest distillation into the open atmosphere, where it begins anew its rounds of collecting fresh properties, in order to its preparation for fresh service. This theory leads us to the consideration of an attempt to increase the natural quantity of the saccharum of malt by adventitious means; but it must be observed, on this occasion, that no addition to water will rise into the vessels of plants, but such as will pass the filter, the pores of which appearing somewhat similar to the fine strainers of absorbing vessels employed by nature in her nicer operations; we by analogy conclude, that properties so intimately blended with water as to pass the one, will enter and unite with the economy of the other, and vice versa. Supposing the malt to have obtained its utmost perfection, according to the criterion here inculcated, to prevent its further progress, and secure it in that state, we are to call in the assistance of a heat, sufficient to destroy the action of vegetation, by evaporating every particle of water, and thence leaving it in a state of preservation fit for the present or future purpose of the brewer. Thus having all its moisture extracted, and being by the previous process deprived of its cohesive property, the body of the grain is left a mere lump of flour, so easily divisible that, the husk being taken off, a mark may be made with the kernel, as with a piece of soft chalk. The extractable qualities of this flour are saccharum, closely united with a large quantity of the farinaceous mucilage peculiar to bread corn, and a small portion of oil enveloped by a fine earthy substance, the whole readily yielding to the impression of water, applied at different times, and different degrees of heat, and each part predominating in proportion to the time and manner of its application. In the curing of malt, as nothing more is requisite than a total extrication of every watery particle, if we had in the season proper for malting a sun heat sufficient to produce perfect dryness, it were practicable to produce beer nearly colourless; but that being wanting, and the force of custom having made it necessary to give our beers various tinctures and qualities resulting from fire, for the accommodation of various tastes, we are necessitated to apply such heats in the drying as shall not only answer the purpose of preservation, but give the complexion and property required; to effect this with certainty, and precision, the introduction of the thermometer is necessary, but the real advantages of its application are only to be known from experiment, on account of the different construction of different kilns, the irregularity of the heat in different parts of the same kiln, the depth of the malt, the distance of the bulb of the thermometer from the floor; for though similar heats will produce similar effects in the same situation, yet the distribution of heat in every kiln is so irregular, that the medium spot for the local situation of the thermometer as a standard, cannot be easily fixed for ascertaining effects upon the whole. That done, the several degrees, necessary for the purposes of porter, amber, pale beers, &c. are easily discovered to the utmost exactness, and become the certain rule of future practice. Though custom has laid this arbitrary injunction of variety on our malt liquors, it may not be amiss to intimate the losses we often sustain, and the inconvenience we combat in our obedience to her mandates. The further we pursue the deeper tints of colour by an increase of heat, beyond that which simple preservation requires the more we injure the valuable qualities of the malt. It is well known that scorched oils turn black, and that calcined sugar assumes the same complexion; similar effects are producible in malts, in proportion to the increase of heat, or the time of their continuing exposed to it. The parts of the whole being so intimately united by nature, an injury cannot be done to the one without affecting the other; accordingly we find that such parts of the subject as might have been severally extracted for the purpose of a more intimate union by fermentation, are, by great heat in curing, burned and blended so effectually together, that all discrimination is lost--the unfermentable are extracted with the fermentable, the integrant with the constituent, to the very great loss of spirituosity and transparency. In paler malts the extracting liquor produces a separation, which cannot be effected in brown, where the parts are so incorporated, that unless the brewer is very acquainted with their several qualities and attachments, he will bring over with the burned mixture of saccharine and mucilaginous principles, such an abundance of the scorched oils, as no fermentation can attenuate, no precipitants remove; for being themselves impediments to the action of fermentation, they lessen its efficacy; and being of the same specific gravity with the beer, they remain suspended in, and incorporated with, the body of it--an offence to the eye, and nausea to the palate, to the latest period. From this account it is evident the drying of malt is an article of the utmost consequence concerning the proper degree of heat to be employed for this purpose. Mr. Combrune has related some experiments made in an earthen pan, of about two feet diameter, and three inches deep, in which was put as much of the palest malts, very unequally grown, as filled it to the brim. This being placed over a charcoal fire, in a small stove, and kept continually stirred from bottom to top, exhibited different changes according to the degrees of heat employed on the whole. He concludes, that true germinated malts are charred in heats between one hundred and seventy-five, and one hundred and eighty degrees, and that as these correspond to the degrees in which pure alcohol, or the finest spirit of the grain itself boils, or disengages itself therefrom, they may point out to us the reason of barley being the fittest grain for the purpose of brewing. From these experiments, Mr. Combrune has constructed a table of the different degrees of the dryness of malt, with the colour occasioned by the difference of heat. Thus, malt exposed to one hundred and nineteen degrees, is white; to one hundred and twenty-four, cream colour; one hundred and twenty-nine, light yellow; one hundred and thirty-four, amber colour; one hundred and thirty-eight, brown; one hundred and fifty-two, high brown; one hundred and fifty-seven, brown, inclining to black; one hundred and sixty-two, high brown speckled with black; one hundred and seventy-one, colour of burned coffee; one hundred and seventy-six, black. This account not only shows us how to judge of the dryness of malt by its colour; but also, when grist is composed of several kinds of malt, what effect the whole will have when blended together by extraction. Experience proves that the less heat we employ in drying malt, the shorter time will be required before the beer that is brewed from it is fit to drink, and this will be according to the following table: ----------------------------------------------------------------------- _A table giving the heats of different coloured malts, and the time beer takes to ripen when brewed from them._ ----------------------------------------------------------------------- 124 Degrees 1 Month. | 138 Degrees 6 Months. | 152 Degrees 15 Months. 130 Degrees 3 Months. | 143 Degrees 7 Months. | 157 Degrees 20 Months. 134 Degrees 4 Months. | 148 Degrees 10 Months. | 162 Degrees 32 Months. _The plain practical process of Malting pale Malt, according to the most approved English method._ Suppose you are about to malt spring or summer barley, and that your steep contains sixty bushels. The time generally allowed for this kind of grain to remain in steep is from forty to forty-eight hours, taking care to give two waters; the first water is to continue on the grain twenty-four hours, then run off, and fresh water put on. This precaution is essentially necessary, in order to make clean bright malt, and should never be omitted. It is further right, at each watering, to skim off the surface of the water the light grain, chaff, and seed weeds, that are found floating on it; all this kind of trash, when suffered to remain in the steep, is a real injury to the malt, and considerably depreciates its value when offered for sale, and not less so when brewed. The depth of water over the barley in the steep need not exceed two or three inches, but should not be less. When the barley has remained in steep the necessary time, the water is let off by a plug hole at the bottom of the steep, with a strainer on the inside of the hole; when the barley is thus sufficiently strained, it should be let down by a plug hole in the bottom of the steep into the couch frame on the lower floor, (or adjoining to it, which would be the better construction,) which is no more than a square or oblong inclosure of inch and a half boards ledged together, and about two feet deep, of sufficient capacity to hold the contents of the steep, and so placed, in upright grooves, as to ship and unship in this frame. The steeped barley is to remain for twenty-four hours in the frame, when it should be broke out, and carefully turned from the bottom to the top, nearly of the same thickness it was in the frame, not less than sixteen or eighteen inches, where it should be suffered to remain twenty-four hours longer, or until the germination begins to appear: but this will be always shorter or longer, according to the temperature of the season, and is generally ascertained by sinking your hand towards the middle of the heap, and bringing up a handful of the grain, which, if regularly germinated, will make its appearance in every grain of barley, by appearing white at one end; at this stage of the process, (supposing the temperature of your malt house sixty degrees,) the heap should be extended on the floor, to the thickness of eight inches; after which it should be turned three or four times a day, according to the season, and the progress of vegetation; gradually reducing the thickness of the couch to four or five inches; but it should be remarked, that as soon as the root begins to dry and wither, the watering pot is to be used; the judicious management of which is one of the most important parts of the process of malting, and should be paid particular attention to. One watering, well applied, will, in most cases, answer the purpose. Two thirds of the whole quantity of water should be given to the upper surface of the couch, then turn it, and give the remaining third of the water to the couch when turned. The whole quantity of water to be used for sixty bushels of American spring barley, may be averaged at fifty-four gallons; this quantity will, consequently, allow thirty-six gallons to be as evenly distributed over the surface of the couch for the first water, as possible; the remaining eighteen gallons to be put on in the same way: when the couch is turned after this last watering, the whole couch should be turned back again; thus, in every turning, the bottom and top should always exchange places. In this stage of the process, care should be taken to turn the couch frequently, to prevent the growth of the root, in order to give the greater facility to the growth of the blade, it being essentially requisite to keep that of the root stationary, to prevent a waste of strength in the grain. Three or four days after watering, is generally found a sufficient time for the blade to grow fully up to the end of the grain; farther than which it should not be suffered to proceed. The couch should be now checked in its growth, and thrown on the second or withering floor, where it should be laid thin, and frequently turned; this continued operation will bring it dry and sweet to the kiln, to which it may be committed without further delay. Although the common practice is to throw it up into what is commonly termed a sweet-heap, and so remain from twelve to twenty-four hours, or until you can hardly bear your hand in it; then, and not before, is it considered fit to go on the kiln. This is a practice that cannot be too much condemned, or too generally exploded, as producing the very worst consequences; a few of which I will mention. Green malt, thus treated, becomes in a manner decomposed; and beer brewed from such malt will never keep long, acquiring a disagreeable, nauseous flavour, rapidly tending to acidity, beside becoming unusually high coloured. Although the malt, before grinding, will have all the appearance of pale malt, this quality can be easily accounted for by the high heat the malt is suffered to acquire in the heap before putting it on the kiln. What I have here mentioned will, I trust, suffice to recommend a more judicious mode of practice. Forty-eight hours for malt to remain on the kiln is enough, as pale malt can be completely dried in that time, if frequently turned, and properly attended to. It is further worthy of remark, that barley malt should in no case exceed fifteen or sixteen days from the steep to the kiln, and is often more successfully effected in twelve or thirteen days. The common practice of maltsters is to allow twenty one days, which generally brings the green malt in a mouldy state to the kiln, to the great injury of flavour and preservation in beer brewed from such malts; whereas, the grain should be brought as sweet and dry as circumstances will allow of to this last and important operation of malting, every part of which requires minute and continued attention. When you suppose your malt sufficiently dry, make a round space in the centre of your kilncast by shovelling the malt to the extremities; after which, sweep this space, and shovel back again your malt from the walls and angles into it; make a round heap of the whole on the centre of your kiln, sweep your kiln all round the foot of your heap; so let it stand two hours, then throw it off; this last operation is performed to give every chance for equal drying. The practice of many maltsters is to take seventy two hours to dry their pale malt, keeping all the time a very slow and slack fire, this is another capital error, and should be corrected with the former ones. Various are the opinions entertained, as to the best mode of preserving malt after coming off the kiln: some are of opinion that the circumambient air should have a free access to it; this opinion, I admit, might have weight if such malt was to be immediately brewed; but where it is allowed to remain in heap for four or five months, and gradually become cool, the less air admitted to have access to it the better; this has been the practice and opinion of the most judicious maltsters I have been acquainted with, and, consequently, is what I would recommend, except in the case of immediate use, where exposure becomes necessary, particularly after grinding, as malt so treated will bear a higher liquor, and yield a more preserving extract. _Winter Barley._ To avoid useless and unnecessary repetitions, it is enough simply to state, that winter barley, being a weaker bodied grain than summer, requires less watering, consequently, a less time in steep, say 36 to 40 hours, and about 32 gallons of water to sixty bushels will be sufficient on the floor; the other treatment the same. _Oats the same_, with about 24 gallons of water on the floor, for sixty bushels, divided as directed in the case of summer and winter barley; the remaining part of the process the same. _Rye Malt._ Rye may be steeped 48 hours, with 48 gallons of water on the floor; the remainder of the process the same, quantity of grain sixty bushels. _Wheat._ The above time in steep, and same proportion of water on the floor, will answer to make wheat malt, suppose 60 bushels, varying somewhat according to season, the time of steeping, and bringing to the kiln; the remainder of the process the same. _Indian Corn Malt, a valuable auxiliary to Brewing materials._ This species of grain well managed, and made into malt, will be found alike useful to the brewer and distiller, but it is peculiarly adapted to the brewing of porter; further, it is known to possess more saccharine matter than any other grain used in either brewing or distilling, joined to the advantage of not interfering with the season for malting barley, as this should commence when the former ceases. The summer months are the fittest for malting this kind of grain, and can be only very defectively made at any other season, as it requires a high temperature to force germination, and cause it to give out all its sweet. The following process, it is expected, will be found to answer every purpose wished for: suppose your steep to contain sixty bushels, after you have levelled it off, let on your water as directed in malting barley; you should give fresh water to your steep at the end of twenty-four hours. If it is southern corn you are malting, it will require to remain in steep seventy-two hours in the whole; if it be northern corn, it will require ninety-six hours, there being a considerable difference in the density of these two kinds of grain; the hardest, of course, requires the most water; and, in all cases, the fresher Indian corn is from the cob the better it will malt. When you have accomplished the necessary time in your steep, you let off your water; and, when sufficiently drained, let it down in your couch frame, where it will require turning once in twelve hours, in order to keep it of equal temperature; the depth of the grain should be about two feet and a half in the frame; as it begins to germinate and grow, open your frame, and thin it down at every turning, until you reduce its thickness to six or seven inches; thus extending it on your lower floor, turning it more frequently, as the growth is rapid. The vegetation of the grain, together with the turning, will by this time make the watering pot necessary; the criterion by which you will judge of its fitness for the water, is as soon as you perceive the root or acrospire begins to wither. Two thirds of your water is to be distributed over the surface of your couch for the first watering, which will require thirty-two gallons, and when turned back again, sixteen gallons for the second watering, making in the whole forty-eight gallons of water to sixty bushels of corn. This water should be put on with a gardener's watering pot, as equally as possible. Supposing this pot to contain four gallons, it will make eight pots for the first watering, and four for the second. In this stage of the operation the turnings on the floor should be very frequent, in order to keep the grain cool, as the heat of the weather, at this season, will be sufficient to promote and perfect the vegetation. The second day after the first watering, if the blade is not sufficiently grown, water again, but in less quantity, say one half. It will be now four or five days more before the couch is ready for the kiln, which will be ascertained by the blade becoming the full length of the corn. After this it should be thrown on the upper floor, and suffered to wither for a couple of days, turning it frequently; by this time the blade will have a yellow appearance, the grain will become tender, and, if tasted, be found uncommonly sweet; in this state it may be committed to the kiln, and dried in the usual way. N. B. It will generally take ten days after it is out of the steep to perfect the malting of southern corn, and twelve days for northern. _Fermentation._ Notwithstanding that progress of improvement in the doctrine of fermentation has, in the last twenty years, far surpassed any thing in the same period that preceded it, we have still much to learn. Fermentation is the instrument or means which nature employs in the decomposition of vegetable and animal bodies, or reduction of them to their original elements, or first principles. Fermentation is, therefore, a spontaneous separation of the component parts of these bodies, and is one of those processes that is conducted by nature for their resolution, and the combination and fermentation of other bodies out of them; therefore, it is one of these operations in which nature is continually present, and going on before our eyes; this may be one reason that a very critical observance of it has escaped our attention. Fermentation brings us acquainted with this unerring axiom; that nothing in nature is lost; or that matter, of which all things are composed, is indestructible. For instance, the vinous process of fermentation, succeeded by distillation, produces ardent spirits, or alcohol, the elements of which are here described. If we pass this alcohol, or spirits of wine, through a glass, porcelain, or metallic tube, heated right hot, provided with a suitable condenser and apparatus to separate and contain the parts or products, it will be decomposed and resolved into its primitive elements, carbonic acid gas, or fixed air, and hydrogen gas, or inflammable air; the oxygen being decomposed and united with the oxygen, or vital air, into carbonic acid gas; the water of the spirit of wine being also decomposed, or resolved into its first principles as herein is stated, forms a part of the produce before mentioned. Hence spontaneous fermentation, vinous, acetous, and putrefactive, is the natural decomposition of animal and vegetable matters, to which a certain degree of fluidity is necessary; for where vegetable and animal substances are dry, as sugar and glue for instance, and are kept so, no fermentation of any kind succeeds. There can be no doubt that spontaneous fermentation first taught mankind the means of procuring wine and other agreeable beverage; observation and industry the means of making spirit and vinegar, the first of which is evidently the produce of art, combined with the operations of nature. With nature for our guide, and our own ingenuity, fermentation has been made subservient to the various products we now obtain from saccharine and fermentable matters, such as sugar, molasses, grain, with which we have made wine, spirits, bread, beer, malt, &c.; which last has much facilitated our practice in fermentation, but proved the tide-ending, or point of stagnation to its further improvement. Relying too much on malted grain in the operation of fermentation, we are presented with some of the most pleasing and instructive phenomena of nature; the resolutions and combinations that are formed during the process of the vinous and acetous stages of fermentation, are interesting, beyond comparison, to the brewer, malt and molasses distillers, vintager, cider and vinegar maker, &c. The elastic fluids and volatile principles that are extricated and escape, formerly so little attended to, are now better understood. The method of commodiously saving, and advantageously applying them, and other volatile products, to the improvement of the fermenting and other fluids, will, I hope, not only form a new era in the progress of fermenting, brewing, distilling, &c. but a new source of profit, that may, in time, lead to a recomposition of those elements from which they were produced, or, at least, the fermentation of vinous fluids, vinegar, spirit, &c. by resorting to an inexhaustible source supplied by nature, of these important materials, and their application to the uses that may be made of that abundance so easily procurable, and at present so unprofitably wasted. But to continue our views to the business immediately before us, let us begin with the several products, by stating that carbonic acid gas, or fixed air, is copiously extracted from fluids in a state of vinous fermentation, and sundry mineral and vegetable substances, easily procurable, for which we have the testimony of our own senses; the same may be said of hydrogen gas, oxygen gas, &c. Presuming these positions granted, let us make a short inquiry into the composition of vinous fluids, &c. Apprehending there are but few people to whom these observations will be useful, but what will allow that all vinous fluids, whether intended for beer, wine, cider, &c. are the produce of saccharine matter, or fermentable matter obtained from the sugar cane, grain, fruit, &c. and the part which art at present takes in this beautiful process of nature, is to facilitate her operations in proportion to observation and experience, in conformity to the object in view, in making wine, beer, cider, spirit, &c.; or, subsequent to the vinous, to forward the progress of the acetous fermentation for the production of vinegar. The saccharine or fermentable matter of vegetables, consists in what is chemically called hydrogen gas, or inflammable air; carbonic acid gas, or fixed air; oxygen gas, or vital air; which last forms nearly one third part of the whole atmosphere, circumvolving our globe in which we breathe; or, more exactly, thirty-seven parts of oxygen, and seventy-three of azotic gas, are the component parts of our atmosphere, except the small proportion of undecomposed carbonic acid gas there may be found in it. Beer, wine, cider, malt and molasses wash, and other product by distillation; spirit consists of these three elastic fluids or airs, in composition with various proportions of water. Water itself is a compound of vital and inflammable air; a proof of this, and of the indestructibility of matter, these two elastic fluids burned together, in certain proportions, and in a proper apparatus, reproduce water. By another chemical process, this very water is reducible to these two substances, vital and inflammable air; hence, we see, that all saccharine and fermentable matter, and their products, by fermentation, are composed of the same materials, and resolvable into the same elements. It is scarcely necessary to give any definition of spontaneous fermentation, after what has been said on the subject; if it was, I would say it is that tendency which all fermentable matter has to decomposition, attended with intestine motion or ebullition, when sufficiently diluted with water, under a certain temperature of the atmosphere, the rapidity of which motion is always accompanied by an increase of temperature, or the change to a greater degree of heat generated within the body of the fermenting fluid, in proportion to the rapidity or augmentation of motion or ebullition excited. Fermentation produced by the addition of yest, or any other suitable ferment, in a fluid duly prepared, is governed by the same laws, and under the same influence of temperature, except when it is accelerated or protracted by the management of the operator, or by the changes induced by the influence of the atmosphere, rendered more or less subservient to his purposes, and produces a similar kind of spirit by distillation, possessing in common the properties of vinous spirit, or is converted to vinegar by the subsequent process of acetous fermentation, but much more productive in quantity and quality, so as to answer commercial purposes. In both spontaneous and excited fermentation, there is a similar escape of a large quantity of elastic fluid, or carbonic acid gas, with a considerable proportion of spirit, and some of the water of the fermented fluid. This gas is known to form a considerable part of mucilaginous substances, as sugar, molasses, honey, malt, and other saccharine and fermentable matter. Although the doctrine of fermentation, as a science, does not enable us to alter the spontaneous course of nature; yet if, by the assistance of the instruments, and means recommended, we are enabled to foresee and provide for the changes induced by the alterations of the atmosphere, we can guard against the inconveniences in some cases, and make them subservient to our purpose in others; so as more securely to conduct the process in each to advantage; and that with unusual facility; complex as it at present appears: it will not only be a great improvement in the present mode of fermentation; but facilitate our progress to still greater improvements in the doctrine of fermentation. Therefore, the rule of our conduct, in these pursuits, should be to watch the operations of nature with the closest attention, and assist her when languid, and control her when too violent; that is, by spurring in one instance, and bridling in the other, and accurately and undeviatingly apply the means proposed in the manner recommended, until experience enables us to improve it; otherwise, we shall only admire, without improving or profiting by her choicest phenomena. The motions of the planets, perplexed and intricate as they must have appeared in the infancy of astronomy, are now calculated and known with ease and precision. Attenuation is a term not unaptly applied to fermentation, the property of attenuation being to divide, then dilute, and rarify thick, gross, viscid, and dense substances, in which some degree of fluidity is pre-supposed; it is, therefore, that kind of dilution or fluidity which is promoted by agitation, and very aptly applied to mark the progress of fermentation, which is itself the process of nature, for decomposing vegetable and animal substances under a convenient degree of fluidity; it exists in intestine motion, either spontaneous or excited, accompanied with heat, which, under certain limits, is proportioned to the vigour of the fermentation, which ends in the decomposition of one class of bodies, and the composition of another; and which may be instanced in the resolving saccharine substances into hydrogen, oxygen, and carbon, and the combining them into inflammable spirits, or alcohol, and inflammable acids or vinegar; to which may be added, the lower you attenuate, the lighter and more spiritous the fermenting fluid becomes; and that attenuation, which is the offspring of fermentation, like the parent process, has its bounds, and can only be conducted with certainty and advantage by the use of the hydrometer, thermometer, &c. In this only lies the difference between the old word fermentation, and the new word attenuation, every thing used as a ferment, or to promote fermentation, is attenuant. The tendency of the vinous process of fermentation is to evolve or disentangle the hydrogen of the fermenting fluid, and unite it, with the carbon and oxygen of the same fluid, into ardent spirit, wine, beer, or alcohol, which last is well known to be inflammable. The tendency of the acetous process of fermentation, is to involve or entangle the hydrogen and carbon of the fermented fluid, with a greater proportion of oxygen, into vinegar, which is uninflammable. The fixed air, or carbonic acid gas, so abundantly extricated during the vinous process of fermentation, which every one concerned in the process is presumed to be acquainted with, is either composed of hydrogen and oxygen, or is a composition of carbon and oxygen, on which philosophers are divided in opinion. As the result is the same with respect to the formation of wine, beer, and spirit, I shall enter into no controversial reasoning on this head, instead of which, I shall endeavour to point out the most effectual mode of saving and profitably applying it, and the other elements, in the composition of wine, beer, spirit, and acid. As in fermentation, spontaneous or excited, there is a sensible escape of carbonic acid gas, or fixed air, it may not be improper to note, that fermentable, or saccharine matter, consists of about twenty-eight pounds of carbon, eight pounds of hydrogen, and sixty-four pounds of oxygen, reducible into fixed, inflammable, and vital air, weighing one hundred subtile pounds in toto, or that every one hundred subtile pounds of saccharine matter consists of such proportions of these airs and gasses. Attenuation is the result of a due resolution of the fermentable matter produced by excited fermentation, which divides mucilages, resolves viscidities, breaks down cohesions, generates heat and motion, extricates the imprisoned gasses, and, by frequent commixture, promotes the action and re-action of the component particles on each other, and by continually exposing a fresh surface and opposition of matter, brings them within the sphere of each other's attraction. As their original attraction is weakened by heat and motion, their expansion is increased by repulsion; and as they revolve, and recede from each other in this way, they are fitted, by the change in their modification, to involve each other, and from new attractions combining with each other into new substances, according to affinity, under changes induced in their nature conducive to this end, which not being exactly known, cannot at present be fully defined. In every brewing, or preparation of saccharine fluid for fermentation, the following phenomena occur: first, _heat_ is either disengaged or fixed: secondly, an _elastic fluid_ is either formed or absorbed in a nascent state: these two indisputable facts form the uniform and invariable phenomena of fermentation, and may be admitted as an established _axiom_, that the proportions, extrication, and action of heat, with the fermentation and fixation of elastic fluids, during the process, are the foundation of the vinous products of the fermenting fluid. In conformity to so rational a theory, I have for many years regulated my practice, the result of which is the object of these papers. These, therefore, are the three great objects which should engage our attention; not only in fermentation, but in every similar process in chemistry, and are the fundamental principles of our doctrine. FERMENTATION being not only a decomposition of the fermentable matter, but of the water of the fluid also; and the fixed air formed during the process being composed of the hydrogen and oxygen of the fermentable matter, and the water of the fluid also, there is a perpetual decomposition and recomposition of that water, which gives fluidity to the whole mass, taking place during the continuance of the process, part of the hydrogen and oxygen of which escapes under the form of fixed air, for want of a proper substance being presented of affinity enough to absorb and combine with it into wine, beer, or spirit, or some other necessary assistance in heat, light, motion, oxygen, hydrogen, carbon, &c. or an intermedium to facilitate the formation of wine, beer, or spirit, in preference to fixed air. Fixed air, or carbonic acid gas, consists of about twenty-five parts of oxygen, and nine of carbon, devested of the mucilage and yest that rises with it. It should be recollected, that the decomposition of pyrites, the formation of nitre, respiration, fermentation, &c. are low degrees of combustion, and though it is the property of combustion to form fixed and phlogisticated airs, both the modes of doing it, and the quantity of the products, depend on the manner of oxygenating them in the changes brought about by the different modes of combustion, or fermentation in the vinous, acetous, and putrid process, which show the affinity between them. Fermentation is a subsequent _low combustion_ of the vegetable oxydes or grain, that has undergone a previous, but partial combustion, something like the slightly charring, or oxydating of wood or pit-coal, by which the oxygenation is incomplete in both, and rendered more complete in the former. An ultimate combustion of the fermentable matter employed, is found only in the putrid process of fermentation, which is a final or total decomposition of vegetable and animal substances, in the actual combustion or burning of wood, charcoal, or bones. In the vinous process we have seen the escape of carbonic acid gas; in the acetous process there is a great escape of azotic gas, or phlogisticated air, from the decomposition of the air of the atmosphere consumed in this process, which consists of about two-thirds of azotic gas, and one third of oxygen gas,[3] the oxygenous part being absorbed in the acetous process, and azotic set free with more or less hydrogen and acetic gas, proportioned to the existing heat. If the heat is beyond a certain degree, a portion of the ethereal part of the new-formed acid escapes also. [3] Twenty-seven parts of oxygen gas, and seventy-three of azotic gas. In the putrid process, the hydrogen escapes under the acriform shape of inflammable air and azotic gas, and nothing more remains than mere earth or water, or both, as the case may be, which is exactly similar to other combustions, of which nothing remains, (if we except phosphorus) but earth or ashes, with what small portion of alkaline or other salts they may contain. This alkaline matter being present during the formation of carbonic and azotic gas, absorbs, to saturation, a due proportion of them, and generates _tartar_. Experience has taught us the truth or justness of this definition, and though it has brought us acquainted with the results of those three stages of fermentation, combustion, or decomposition, we have certainly overlooked the means of applying them with all the advantage they admit of in the business which is the subject of these papers, and which a little time and close observation must convince us of; and how much has been hitherto lost, with the means of saving it in future, shall be presently explained, and particularly pointed out. In the prosecution of this design, where I may not be able to give an unexceptionable demonstration, I hope always to be provided with a practical proof, which may prove equally beneficial. Let us now see what passes in a state of low combustion, such as may be the result of fermentation in vegetables, arising from heat, moisture, and motion, when impacted together. The most obvious occurrence of this nature is found in new hay, which, under these circumstances, for want of care and attention, often spontaneously takes fire, particularly in wet seasons. Fermentation, being one of the lowest degrees of combustion, is here the spontaneous effect of the moist hay being impacted together, and not properly made, that is, without the superfluous juices being dried out of it, by which it retains a sufficient degree of fluidity or moisture to begin a fermentation, in which heat and motion are generated, and light, in a nascent state, extricated; these appearances accumulated and accelerated by incumbent pressure, the redundant moisture being soon exhausted, and the heat and motion increasing, the actual combustion of the mass takes place, which is much facilitated by a decomposition of the water of this moisture, and the air of the atmosphere, unavoidably insinuated between the interstices formed by the fibres of the hay, as they are impacted together into cocks, or stacks, breaks out into actual flame, or _light visible_. These are no novel appearances, but such as fall within the observation of every one; and the candid maltster will acknowledge, that from the same cause, though differently produced, similar effects may, and sometimes do, happen in the malt house, in the preparation of that modern article of luxury, by which we are enabled to make malt wine; and these instances are sufficient to prove fermentation to be a low degree of combustion, and to both simplify and explain the justness of this doctrine. The malting of corn is the first stage of vegetation, low combustion, and fermentation. From observation and reasoning on what passes before our eyes, we discover the low species of fermentation, in which the malting of corn consists, to be a low degree of combustion, which, for want of due attention, may break out into actual flame. We were always acquainted with the _effect_: now reasoning on the subject brings us to a knowledge of the cause. To any one well acquainted with the nature of fermentation, it must be manifest, that the malt distillers have paid more attention, and made greater progress in the improvement of the process than any other class of men interested in the success, though far from having arrived at their _ne plus ultra_. The introduction of raw or unmalted corn; the close compactness of their working tun, or fermenting backs; the order and progressive succession with which they conduct the process; and the pains they necessarily take to arrive at a perfect attenuation, by a long protracted fermentation, with the early conviction of a reward proportioned to their diligence, and the success attending their best endeavours, when not frustrated by intervening causes, must be stronger inducements with them to delight in this instructive process of nature's formation, than with the brewer, who has not these immediate tests to encourage his labours, which the others daily derive from distillation, and which so quickly and uniformly terminates their hazards and success. The principal object in their view being a high and deliberate attenuation, with a full vinosity, without any further regard to the quality or flavour of their mash, as the combination of these qualities alone produces the required strength, in the cleanest manner. The brewer's cares are many, and of longer duration: he is the vintager of our northern climates: his porter or ale should be an agreeable malt wine, suited to the palate of the district or neighbourhood he lives in, or, ultimately, to the taste of his customers. The time he has allotted himself for attenuation was first founded in error, derived from ignorance of the subject, and slavishly continued by that invincible tyrant, custom. Hurry marks the progress of his fermentation, which can only be corrected by his speedy mode of _cleansing_, and the consequent but necessary perishing of a part. He must begin with more accuracy at the mash tun than the malt distiller, as it is there he must not only regulate the strength, but, partially, the flavour and transparency of his malt wine. His object does not end with the malt distiller's, nor, like his, concentre in one focal point, the solution of the whole of the farina of the plant or grain employed, regardless of milkiness or transparency; he must carefully take the heats of his liquor, so as to solve and combine the qualities he has in view; which, if he misses in the first mash, is partly irremediable in the succeeding ones. His cares do not end here; independent of the minutiæ of fermentation and cleansing, he has the flavour, fining, and bringing forward of his _malt wines_, nearly as much as the strength, to consider and employ his attention. It will scarcely be supposed that I would make these observations merely with a view of drawing this comparison, though even it might throw some light on the subject, without an attempt at supplying the defects pointed out, and remedying the evils represented. When the carbonic acid gas, or fixed air, so often mentioned in these papers may be rendered subservient to part of the improvements I have in view, and which is the constant, abundant, and uniform result of low combustion, or vinous fermentation, in proportion of thirty-five pounds weight to every hundred of saccharine or fermentable matter, fermented in a due proportion of liquor, or water; from the decomposition of which last, and the absorption of its oxygen, it is principally obtained. We have previously seen that one hundred pounds of fermentable matter consists of eight pounds of hydrogen, twenty-eight of carbon, and sixty-four pounds of oxygen; we have also seen that about thirty-five pounds of carbon is extricated and detached from this quantity of fermentable matter, properly diluted in water during fermentation; allowing the usual quantity of spirit at the same time to be formed by the process of this superfluous carbon, (as it now appears) must come principally from that decomposition of the water of dilution, and not from saccharine matter employed, which contains altogether but twenty-eight pounds of carbon, the whole of which must necessarily go to the formation of the fifty-seven pounds of dry alcohol produced. But not to descend too deeply into particulars that might lead into discussions not absolutely necessary in this place, let us take the produce of ten gallons of ardent spirit, at one to ten over proof. We here find that much more carbon has been generated, and given to the atmosphere, than went to the composition of this quantity of spirit, independent of the large quantity of alcohol dissolved in, and carried off by it, in its flight as before observed. Allowing the average quantity of fermentable matter in a quarter of malt, barley, or other grain, to be only seventy-five pounds, then four quarters will be equal to three hundred subtile pounds of raw sugar; or eighty quarters of the one will be equal to six thousand pounds of the other, or three tuns weight of unadulterated molasses. If we estimate the superfluous carbonic acid gas of this quantity of materials at only twenty-eight pounds per hundred, that will be sixteen hundred and eighty pounds dissipated during the fermentation, which is a loss, on every brewing of this quantity of materials, of upwards of forty-one gallons of spirit, of the strength of one to ten. What is computed here in spirit, may easily be applied to wine, porter, beer, ale, sweets, &c. In barrels allowing three gallons and three quarts of spirit per barrel to the former, and four gallons per barrel to the latter, which gives eleven barrels and three quarters of the one, and ten barrels and a quarter of the other, lost on each brewing of eighty quarters of malt, or the average of that quantity of other materials, by the mismanagement of the fermentation in one point only. It must appear evident to every person capable of investigating this calculation, that every six or seven pounds of carbon, fixed upon each quarter of malt, or other materials, there will be an augmentation of gravity or strength on this number of quarters, of ten or twelve barrels each brewing; that is, every six or seven pounds of this fugitive carbon that we arrest and fix in the fermenting fluid, as a component part of the subsequent produce, by presenting the requisite portion of oxygen and hydrogen, for the purpose within the sphere of each others attraction, we increase our strength in the before-mentioned _ratio_. It is of little moment whether this redundant gas comes from the water of dilution or from the fermentable matter, as under, if we can by any means turn it to account. We have presumed the average quantity of fermentable matter at seventy-five pounds per quarter; this must be evidently on the best goods; this will give us a length of three barrels per quarter of malt of eight bushels, of twenty-five pounds per barrel, specific gravity. Suppose the apparent attenuation of these goods to be nineteen pounds, the transparent gravity will be six pounds per barrel, viz. Gravity of the worts in the cooler just before letting down into the guile-tun, per barrel, 25 lb. Apparent attenuation per barrel, 19 lb. Transparent gravity per barrel, 6 --- 25 lb. Or take it as it really is, viz. specific gravity per barrel, 25 lb. Real attenuation per barrel, 13 lb. 8 oz. Yest and lees, 5 8 -------- 19 lb. Gravity per barrel, when transparent, 6 --- 25 lb. It may be said that nineteen pounds is the real attenuation, and the yest and lees produced is part thereof, as the fluid, or beer, in a state of transparency is but six pounds per barrel specific gravity, and it may, in some degree, be allowed to be so, as there is really so much gravity lost during the process of fermentation. If we multiply thirteen pounds eight ounces, which I have called the real attenuation, by four, we shall find the result to be fifty-four pounds, which is nineteen pounds more of superfluous gas upon four barrels of worts, of twenty-five pounds gravity each, than is extricated from an equivalent quantity of saccharine matter; that is, from one hundred pounds of raw sugar or one hundred and twelve pounds of molasses, and their respective waters of dilution, when the yest and lees do not exceed five pounds eight ounces per barrel. This may be truly called an analysis of the fermentable matter, giving the component parts tolerably exact; though much depends on the management of the fermentation, and the subsequent cleansing. By this analysis it appears, that the mucilage of malt, or grain, gives out more gas than the mucilage of sugar; and leaves a doubt on the mind whether to adjudge the superfluous gas to the fermentable matter, or to the water of dilution, or partly to both; but so it is, that these are the products, whatever source we derive them from, and there is no denying facts. The yest first added is not brought into this account. There is a great similarity of appearance between the two species of low combustion, fermentation and respiration. Fermentation, like respiration, is the spontaneous effort of involuntary motion to decomposition; and in the fermenting mass, as in the animal system, it raises the temperature of both above that of the surrounding atmosphere: that is, it is the cause of heat and involuntary motion, both in the fermenting mass and in the animal system; and, like slow combustion, consumes both, and resolves them into their first principles, from which tendency the latter is constantly withheld by the ingesta, fuel, or food, thrown in. I am well aware I must not carry this reasoning any further. Deep investigation may be thought not to be the object of our research; but we must always have two things in view in inquiries of this nature; indeed, in every pursuit of useful knowledge, where, like the present, it is connected with the first principles, to pursue the winding path of nature, through all her meanderings, up to the ultimate source of these elements, which are the instruments of her operations; and when we are favoured with a knowledge of these, either as the reward of laboured assiduity and attention, or the result of chance, to copy the original as close as we can. I know I shall be justly accused with tautology. I must plead guilty to the charge, not having leisure to apply the pruning hook of correction. The misfortune is, that new doctrines must appear in a new dress, by which they wear the garb of novelty, though, with respect to first principles, there is nothing new under the sun; yet the application of these principles might have remained in oblivion for ever if not called into action. The man who in an age calls them into action, and beneficially applies them for the good of that community of which he is a member, may be virtually, though not literally, called the discoverer of a principle. The man that projects, and the man that executes a voyage of discovery, have superior claims to the man at the mast head who first cries out land. The new turn that the discoveries of modern philosophers has given to natural philosophy, requiring a change of names as well as system; unusual words are unavoidably introduced to express new terms of science, which gives a different character and fashion to the whole, that I should have great pleasure in avoiding, were it possible, which it obviously is not, finding it easier to glide down the stream than oppose its torrent. Notwithstanding that I have calculated upon nineteen pounds only of twenty-five pounds per barrel of fermentable matter being attenuated, and have even in that quantity included five pounds eight ounces of lees and yest, (the least quantity produced,) such calculation must not be admitted to preclude the practicability of attenuating almost every particle of fermentable matter, and replacing it with an equivalent particle of spirit, if that spirit which is now carried off by the avolation of the fixed air, is, agreeably to my proposal, either arrested in its flight, or filtered, after its escape from the guile tun and cleansing vat, by the proper apparatus. Having in a former part of these papers observed, that attenuation may be carried too far, it may be necessary for me to reconcile these seemingly opposite positions, which should be understood in this way: When the quantity of fermentable matter, suspended in a barrel of worts, intended for beer, or ale, is from five to ten pounds more than twenty-five pounds per barrel, every particle of it may be safely attenuated, as the quantity of spirit generated will be sufficient to preserve the beer, or ale, for any requisite length of time, provided it has been properly hopped, &c., or in lieu thereof, received certain other additions to improve its vinosity, strength, and keeping; when the quantity of fermentable matter in worts is from five to fifteen pounds per barrel less than twenty-five pounds, the height of the attenuation ought to be limited on keeping beer and ale; the spirit generated being insufficient to preserve so much fermented fluid in a drinkable state for any length of time, with the usual additions only, even during the summer heats of our own climate; and if so, it is totally unfit for either exportation to warm latitudes, or for keeping at home. For the right understanding of these observations, we should consider that the unattenuated fermentable matter is perpetually furnishing a gradual supply of fixed air and spirit, by means of the imperceptible fermentation always going on in vinous liquors. Weak beers and ales fret and spoil very soon in warm weather, which proceeds from the development and avolation of their fixed air; strong beers and ales have their limits under the same influence of heat, time, change of the atmosphere, &c., and owe their preservation to two things, viz. to a due proportion of fermentable matter unattenuated, or the quantity of spirit they contain; as under these circumstances they are either preserved by the spirit already formed, or that continually supplied by the spontaneous decomposition of the fermentable matter they contain, slowly developing and yielding a fresh supply of air and spirit; hence beer and ales, not too highly attenuated, derive strength and spirituosity from age, when properly stored or cellared, and duly secured from the changes of the atmosphere. These observations are applicable to sweets, or made wines, and to those which are the produce of the grape, the progress of fermentation and attenuation being (or ought to be) interrupted in them by racking off, which is similar to cleansing in beers and ales: and in Madeiras, and other dry wines, the incipient acidity is corrected and restrained, by proper additions introduced in the early part of the process, and with others of similar effect when the wines are making up, either for use or exportation. We may gather from these observations, that worts attenuated for beer or ale, to the decomposition of all their fermentable matter, that is, attenuated so high, or so low, that their specific gravity is reduced to the standard of common water, and from that to the degree of levity spirit is known to give to water, in the proportion to the quantity added, and left to the preservation of the spirit formed, they have little or no auxiliary assistance from their original products, already exhausted by the highest or completest attenuation obtainable; an important circumstance, always to be attended to, particularly by those who affect an unnecessarily high attenuation! The intelligent brewer may, by the assistance of these observations, form a most accurate rule for the regulation of his future conduct in the management of fermentation, according as his beer or ale is to be weak or strong, or for present use or long keeping; for the accomplishment of which, the use of the hydrometer and thermometer claim his peculiar attention, and will undoubtedly answer his expectations, when joined to the certainty he is now at, of knowing when he is, or is not, to expect the development of fixed air and additional spirit, by which he can govern himself accordingly. These observations lead to a removal of the difficulties that lay in the way, and, at the same time, suggest a mode of applying the present, or of constructing a future _hydrometer_, for ascertaining the strength or the quantity of the vinous spirit in beer, wine, ale, and other fermented fluids, which has long been a desirable object. The distiller, having none of these niceties to attend to, is governed by the ultimate extent of the attenuation the worts, or wash, is found capable of, and which is both assisted and protracted by its superior density, in its progress from specific gravity to specific levity, if such an expression is admissible. Fermentation, begun in a fluid more or less saturated with saccharine or fermentable matter, the process is finished sooner or later, and usually in proportion to the degree of saturation, and the being conducted with more or less vigour under a well regulated temperature; for the more a fluid abounds with this matter, the grosser and denser it must necessarily be, and the longer will the attenuation be protracted; the longer it is protracted, in air-tight vessels, and in a healthy and vigourous state of decomposition, the more spiritous and strong will that wash turn out, and the greater the produce of spirit in distillation; hence, it is both protracted and assisted by its density. A languid may be truly called an unhealthy decomposition, it being productive of diseases common to misconducted fermentation, acidity, putridity, and lack of spirits, with a tendency to precipitate and burn upon the bottom of the still; hence, all the decompositions are confounded together, as in spontaneous fermentation. The formation of acidity during the process, is not of that injury to the distiller that it is to the brewer, nor is this recent acidity vinegar, as has been supposed by some chemists, but the incipient state of combination of resolving elements, whose particles are in that juxtaposition best suited to absorb developing hydrogen in a nascent state, and intimately to combine with it into vinous spirit, the approximation to which is promoted by time and incumbent pressure: these positions shall be explained as I proceed. The reason that putridity is so rarely discovered in excited fermentation, is, that it is usually counteracted by the previously evolved acidity, and corrected, but not saturated or neutralized; for, were that the case, the putrid could not immediately succeed the acetous process in the same fluid, nor exist together, as they are known to do in declining beer, vinegar, &c. The reason that acidity is not more frequently observed and attended to than it is, is because of its being sheathed or covered by the unattenuated sweets, or fermentable matter of the wash that remains undecomposed. On the other hand, when acidity is very prevalent, it may be mistaken for unattenuated fermentable matter, acidity increasing the density and specific gravity of the fluid. Putridity, from the avolation of its products, promotes levity, and that in proportion as its increase surpasses that of the general acid; and it is not until the action of the acetous becomes languid, that the putrid process gains the ascendency, when it is then difficult to overcome. Although these observations may show how the hydrometer, or its use, in unexperienced hands may be baffled, they both distinguish and explain the value of its application; they do more--they elucidate the doctrine of fermentation, and illustrate the goodness of Providence, who has made nothing in vain, but provided nature with its own resources for conducting every operation in the great plan of the universe with uniform and unerring security. In the decomposition of fermentable matter, either by combustion or fermentation, (which I have defined to be synonimous,) a portion of inflammable air, or hydrogen, is first evolved; secondly, another portion of inflammable air, united with pure air, or oxygen gas, evolves under the form of fixed air; this is the constant and uniform phenomena of these decompositions, and are progressively going on from the beginning to the end of the fermentation, while there is any fermentable matter to attenuate. A due portion of oxygen uniting in a nascent state with a correspondent portion of inflammable or hydrogen, and fixed air, forms the spiritous particles dispersed through the fermenting fluid, which create vinosity, and constitute it wine, beer, or wash. During which, so great is the avolation of fixed air, (as we have seen,) that much of the ethereal part of the new formed, or, rather, the scarcely-formed spirit, is carried off with it in a gaseous state. This is much assisted by the agency of the atmosphere, which is the solvent and receptacle of ethereal products, whose affinity for them must be as great as it is perfect and immediate--which demonstrates the necessity of having air-tight vats. When we consider the composition of the atmosphere, and that it owes its formation and existence to this cause, and, thereby becomes the menstruum of all created matter, we may be better able to understand the composition and formation of vinous spirits, and, by closely copying the original, more successfully imitate nature. We have seen that the principal phenomena in fermenting fluids is a brisk intestine motion of their parts, excited in all directions with a loss of transparency, or a muddiness, a hissing noise, the generating of gentle heat, and an exhalation of gas. This heat, we must now observe, is always very sensible before the extrication of any gas. We have adverted to the similarity existing between respiration and fermentation, which is remarkably so in the equality of heat produced in both in a healthy state of either, and which seldom exceeds ninety-six degrees of Fahrenheit's thermometer; but there are instances of their being much higher in both, without producing much injury to either. Instances of this could be adduced at home, without referring to warmer climates of the East and West Indies, where the temperature of the atmosphere is so much higher than with us; and that the temperature of the fermenting fluid, when at its height, always exceeds that of the surrounding atmosphere in these latitudes, which makes the similarity still stronger between these two decomposing processes. This is a general and just remark; but, in order to regulate it by practical facts, we must name the medium standard of heat, which rarely exceeds eighty-five degrees with the brewers; this is the medium of seventy-four and ninety-six degrees; but the medium heat is not unfrequently up to ninety-six degrees in the distiller's fermenting backs of Great Britain. Much depends on the degree of temperature the fermentation is pitched at: here, nothing is spoken of but the cleansing heat with the brewers, and the medium heat with the distillers. For the maintenance of combustion, the free access of air being necessary, an objection may be raised to air-tight vats, as unfit to carry on this process in, to the exclusion of external air; which objection may seem to gather force from the compression it occasions of the fixed air on the decomposing fluid, which is allowed to extinguish active combustion. I must acknowledge these are formidable objections to my definition of low combustion, but I by no means find them unanswerable. The aptitude of new hay, malt, and other vegetable matters, to spontaneous combustion, when impacted together by incumbent pressure, and a certain degree of moisture, should be recollected; and that this tendency is not destroyed by excluding the admission of external air, but by quickly cooling and dividing the impacted hay. The great quantity of oxygen, or vital air, both in the water of dilution, and in the fermentable matter, with which the fluid is more or less saturated, should be also recollected, which is about eighty-five parts in the former, and sixty-four parts of one hundred in the latter. Though, in an unelastic or fixed state, it is one of the properties of combustion to disengage and render it elastic, great part of which, during the low combustion which it supports, and in which heat is visible or perceptible, and light in an invisible state developed, three parts of this oxygen, with about one third of its weight of carbon, is converted into an elastic state, under the form of fixed air, that separates from the decomposing mass; a circumstance attending also on the combustion of coal and other combustible substances during their decomposition by that process, which supported in them by the external air of the atmosphere, where heat and light are both visible from the intensity and velocity of the combustion; and wholly invisible in the former, not from exclusion of external air, but from the length of time elapsed in low combustion; the one being performed instantaneously, and the other taking several days from its decomposition. Although fixed air is known to extinguish a lighted candle, and destroy animal life, that is, to be equally unfit for the combustion of inflammable bodies, or the support of animal respiration, it is also known to be as successfully employed as atmospheric air, or even dephlogisticated air, to melt glass, &c., when applied to the clear flame of a wax candle, by passing a current of it through a blow-pipe, to direct that flame on the glass to be melted.[4] [4] Count Rumford on the Economy of Fuel. This will not be so much to be wondered at, when we consider that the proportion of vital air in fixed air is as twenty-seven to nine, and in atmospheric air, the proportion of azotic gas or phlogisticated air, to vital air, is as seventy-three to twenty-seven; therefore, the former contains three fourths of vital air, and the latter little better than one fourth; but the fixed air is in a combined, and the phlogisticated air in an uncombined state. Among the processes made use of by nature for the decomposition of vegetable and animal substances, fermentation, or low combustion, is a principle one. Air, in a fixed or unelastic state, may be as necessary here as air in an elastic state is known to be in the active combustion of inflammable bodies. Chemists and philosophers are no strangers to two sorts of combustion, one in external air, and the other in close vessels. But this is not the combustion alluded to in fermentation, where all the requisites for complete decomposition is to be found independent of contact with the atmosphere; here one part is oxygenated at the expense of the other, and the other disoxygenated in favour of it. Nor does the solution, or decomposition of metals by acids, the combustion of inflammable and vital air for the production of water, stand in need of external heat or fire, any more than the low combustion in which fermentation consists for the production of spirit, beer, or wine, than that generated by the self-operation of its own temperature; similar to this is the self-animating principle or power with which nature has endowed the animal body of generating its own heat by respiration. In fermentation, the caloric, or matter of heat, which is plentifully disengaged by the condensation of oxygen, is prevented from breaking out into flame with the condensing hydrogen, from the presence of affinities in the fermenting mass, ready to absorb and fix them into vinous spirit, ale, beer, &c., with the other component element, carbon; by which they are too instantaneously taken up and fixed, to amount to more than bare ebullition, and pass at once from an incipient state of elasticity, to a fixed and non-elastic one, while the redundant heat, which would otherwise appear, is taken up and carried off by the abundant formation of carbonic acid gas, which requires so great a quantity of caloric to render it permanently elastic, as not only keeps this sort of combustion under ignition, but much below the degree of heat at which the accumulating vinous spirit could be raised to the evaporable or distilling point, though capable, as already observed, of detaching a considerable portion of it with the volatile gas, and of the water of solution, or the water of composition recently formed from the present attractions in its most volatile and incipient state of formation; both which we have seen ascend with the fixed air extricated, partly in a combined, and partly in an uncombined state. One part of hydrogen is sufficient to saturate and fix above five of carbon, and they require nearly sixteen parts of oxygen to complete their formation into alcohol, while the water of dilution undergoes a proportionate decomposition and recomposition, to assist the resolutions and combinations, and support the admirable equilibrium preserved by nature. At the same time that the extreme levity of the hydrogen gas accounts for the great quantity of heat which it holds in combination, and the high temperature requisite to effect its decomposition, and that such is its capacity for heat, that though combined with oxygen and water, it still possesses the property of absorbing a great deal more. It is this property that renders aqueous vapour lighter than atmospheric air in which it ascends; yet we have just now demonstrated the resolution and combination of hydrogen gas, and oxygen gas, both extricated from the fermentable matter and the water of dilution, and their formation into spirit, &c., at a temperature not many degrees above that of the incumbent atmosphere, and no higher than that excited by respiration in the animal system. In which we have shown the vegetable oxyde, (saccharine matter,) when reduced by the admixture of water, to form the worts or wash, to be a carbonated hydrogenous fluid, containing the elements of wine, beer, ale, spirit, &c., and the mode of producing them under circumstances conducive to their formation; these are motion, heat, pressure, and mutual attraction, called into existence by a species of low combustion, or fermentation, somewhat similar to respiration. In which the materials, the products, and the liberation of caloric are ultimately the same, whether the operation is attended by visible fire from the velocity of action, or weak incalescence from the slow progression of its motion; in which the component elements are continually assuming a gasseous form, and as constantly losing it by the force of mutual attraction for each other. No sooner is the equilibrium broken, in one instance, by their gasseous appearance, than it is restored by their condensation, and the heat liberated by the latter taken up by the former, by which the equilibrium is preserved; in this consists the increase of temperature above that of the surrounding atmosphere, accompanied by the discharge of fixed air; to fix, and advantageously apply which, shall be the next consideration; and, by an accurate imitation of the modification employed by nature, to render the fermenting fluid so much the stronger by such fixation. To accomplish which, we must advert to what has been delivered in the preceding pages, particularly to the proportions in which the equilibrium preserved by nature consists, and exactly to her manner of combining them in sugar, malt, and other saccharine matter, her mode of breaking this equilibrium, or decomposing them by fermentation, and recombining them into wine, beer, &c., and by the same process restoring the equilibrium. It cannot be doubted, but that, in the investigation of the acetous process of fermentation with the attenuation we do the vinous, they will mutually reflect light on each other; in which it will come out that wine, beer, ale, vinegar, spirit, &c., are not the only commercial preparation to which the doctrine of fermentation, or low combustion, may be advantageously applied, but also to others, that are perhaps equally important and productive. The cleansing being at the meridian, or greatest temperature of the heat of the fermenting fluid, and the object of that cleansing being to reduce the heat, and thereby allay the violence of the fermentation, by which an immediate decomposition takes place, the lighter impurities buoyed up to the top of the fluid flows off with the yest, while the heavier dregs descend to the bottom, and the fermentation gradually declines as the cleansing draws to a conclusion, and the fermenting fluid forms a turbid heterogeneous mass, very perceptibly approaching towards a transparent homogeneous fluid in its progress to a drinkable state. In laying out a brewery, the air should have free access to the coolers on all sides, under and over; cleansing vessels should be similarly situated, and, if avoidable, the coolers should not lay immediately over them, to raise their temperature, which should not be many degrees above that of the atmosphere, at temperate, which is fifty-two degrees; but the descent from the cleansing heat (seventy-five to eighty-five) should be progressive, that is, not sudden. A sudden chill would precipitate the grosser, and diffuse the lighter dregs throughout the fermenting fluid, which should be thrown off from the surface in cleansing; this would retard the fining, and empoverish the beer or ale; while the mode recommended will be found to promote transparency, and give strength and body, that is, fullness and spirituosity. In general, the cleansing commences too soon for the strength and quality of the goods, particularly for porter, since the introduction of a greater proportion of pale malt than formerly used; a more perfect fermentation is now requisite to keep up the genuine distinction in that flavour of porter from ordinary beers and ales, which, since the change of _lengths_, has much declined, though the only characteristic quality that gives it merit over other malt liquors--an object that deserves consideration in this great commercial branch of trade, and source of national wealth, where the loss of distinction will be the loss of trade. The rough, astringent, thirst-creating smack is the produce of the brown malt, and a well conducted fermentation. The porter now brewed can no more bear the sudden chill of a cooling atmosphere in the barrel cleansing, without too immediate a condensation and separation of its parts, than it is able to sustain the quick changes of a warm atmosphere, without an immediate tendency to acidity. As things now are, either extreme can only be avoided by a more attentive advertence to the mode of _cleansing_, so as to prevent a predominant tendency to either by adopting the means proposed, or such other, on the same principles, as are equally likely to preserve the quality, increase the strength, promote transparency, and avoid acidity. I know it may be urged by the most able brewers, that a high and rapid fermentation in the cleansing is a principal cause of that flavour for which porter is distinguished; that this kind of fermentation leads to a more perfect attenuation; and some of them may, with great truth, add, a perfect attenuation is the genuine mode of early bringing beer forward. This I most readily grant; it is the doctrine I wish to inculcate. The greater gravity of keeping beers, preserves them in a _mild state_, while their spirituosity prevents acidity. The flavour of the colouring matter now in use, nor the change it induces, is not, by any means, adapted to preserve the genuine flavour of porter, or compensate for that made in the change of malt; a change I by no means condemn, with respect to the malt; but however advantageous to the length, we must not altogether give up flavour, while we may equally as well, and indeed much better, preserve both by a due admixture of each sort of malt, and with suitable additions and proper correctives in the process or preparation of porter, both salubrious; as by the subsequent mixture of stale and mild beer, before sending out, or, afterwards, by drawing them from different casks into the same pot, when on draught, to suit the palate of each respective customer. I hope it is by this time understood, that my views are to raise the _Process of Brewing_ above the vulgar error that tyrant custom has entailed on it, and by the free exercise of the brewer's abilities, both in a scientific and tradesman-like manner, so as advantageously to preserve flavour and quality, with almost any proportions of every sort of malt he may occasionally be obliged to use. The world is continually exclaiming that _experience_ is better than _theory_. This is very true; for example, he who has had a very long experience, may, in general, perform operations with tolerable exactness; but this he undeviatingly does by certain stated means, without any deeper intelligence of the process. I would, with Mr. _Chaptal_, compare such a man to a blind person who is acquainted with the road, and can pass along it with ease, and perhaps even with the confidence and assurance of a man who sees perfectly well, but is at the same time incapable of avoiding accidental obstacles, of shortening his way, or taking the most direct course, and alike incapable of laying down any rules which he can communicate to others. This is the state of the artist of mere experience, however long the duration of his practice may have been, as the simple performer of operations. Brewing, fermenting, distilling, &c., are branches of commercial chemistry, that generally challenge the attention and secure the protection of those governments that constitute them sources of revenue and trade. Chemistry is as much the basis of the arts and manufactures, as mathematics is the fundamental principle of mechanics. In the process of brewing porter, ale, threepenny, &c., to be subsequently treated of, the practical minutia of fermentation and attenuation shall be circumstantially laid down in each, so as to account for, and distinguish the variety of flavour, &c., assignable to each _cause effected_ by the different modes of treatment. _Hops, the best method of cultivating and raising them._ A rich, deep soil, rather inclining to moisture, is, on the whole, the best adapted for the cultivation of hops; but it is observable that any soil (stiff clay only excepted) will suit the growing of hops when properly prepared; and in many parts of Great Britain they use the bog-land, which is fit for little else. The ground on which hops are to be planted should be made rich with that kind of manure best suited to the soil, and rendered fine and mellow by being ploughed deep, and harrowed several times. The hills should be at the distance of six or eight feet apart from each other, according to the richness of the ground. On lands that are rich, the vines will run the most; the hills must therefore be the further apart. At the first opening of the spring, when the frosts are over, and vegetation begins, sets, or small pieces of the roots of hops, must be obtained from hops that are esteemed the best.[5] Cut off from the main stalk or root, six inches in length, branches or suckers, most healthy, and of the last year's growth, if possible to be procured; if not, they should be wrapped in a cloth, kept in a moist place, excluded from the air. A hole should then be made large and deep, and filled with rich mellow earth. The sprouts should be set in this earth with the bud upwards, and the ground pressed close about them. If the buds have begun to open, the uppermost must be left just out of the ground, otherwise cover it with the earth an inch. Two or three sets to a pole is sufficient, and three poles to a hill will be found most productive; place one of the poles towards the north, the other two at equal distances, about two feet apart. The sets are to be placed in the same manner as the poles, that they may the easier climb. The length of the poles may be from fourteen to eighteen feet, according as the soil is rich or poor. The poles should be placed so as to incline to each other, meet at their tops, and there be tied. This is contrary to the European method, but will be found best in America. In this way they will strengthen and support each other, and form so great a defence against the violent gusts of wind, to which our climate is frequently subject in the months of July and August, as to prevent their being blown down. They will, likewise, form a three-sided pyramid, which will have the greatest possible advantage from the sun. It is suggested by experience, that hops which grow near the ground are the best. Too long poles, therefore, are not good, and care should be taken that the vines do not run beyond the poles, twisting off their tops will prevent it. The best kinds of wood for poles are alder, ash, birch, elm, chestnut, and cedar, their durability is directly the reverse of the order in which they stand; charring, or burning the end put into the ground, will preserve them. Hops should not be poled till the spring of the second year, and then not till they have been dressed. All that is necessary for the first year, is to keep the hops free from weeds, and the ground light and mellow by hoeing and ploughing often, if the yard be large enough to admit of it. The vines, when run to the length of four or five feet, should be twisted together, to prevent their bearing the first year, for that would injure them. In the months of March or April, of the second year, the hills must be opened, and all the sprouts or suckers cut off, within one inch of the old root, but that must be left entire with the roots that run down;[6] then cover the hills with fine earth and manure. The hops must be kept free from weeds and the ground mellow by hoeing often through the season, and hills of earth gradually raised around the vines during the summer. The vines must be assisted in running on the poles with woolen yarn, suffering them to run with the sun. By the last of August, or the first of September, the hops will be ripe, and fit to gather. This may be easily known by their colour changing, and having a fragrant smell; their seed grows brown and hard. As soon as ripe, they must be gathered without delay, for a storm or frost will injure them materially. The most expeditious method of picking hops, is to cut the vines three feet from the ground, pull up the poles and lay them on crotches, horizontally, at a height that may be conveniently reached, put under them a bin of equal length, and four may stand on each side to pick at the same time. Fair weather should always be chosen to gather hops and they should never be gathered when dew or moisture is on them, as it subjects them to mould. They should be dried as soon as possible after they are gathered; if not immediately, they must be spread on a floor to prevent their changing colour. The best mode of drying them is with a fire of charcoal and kiln, covered with hair cloth in the manner of a malt-kiln.[7] The fire should be steady and equal, and the hops gently stirred from time to time. Great attention is necessary in this part of the business, that the hops be uniformly and sufficiently dried; if too much dried they will look brown, and, of course, be materially injured in their quality, and proportionably reduced in their price. If too little dried, they will lose their natural colour and flavour. They should be on the hair cloth about six inches thick after it had been moderately warmed, then a steady fire kept up till the hops are nearly dry, lest the moisture or sweat the fire has raised should fall back and change their colour. After the hops have been in this situation seven, eight, or nine hours, and have got through sweating, and when struck with a stick will leap up; then throw them into a heap, mix them well, and spread them again, and let them remain till they are all equally dry. While they are in a sweat, it will be best not to move them for fear of burning, slacken the fire, when the hops are to be turned, and increase it afterwards. Hops are sufficiently dried, when their inner stalks break short, and their leaves become crisp, and fall off easily. They will crackle a little when their seed is bursting, and then they should be removed from the kiln. Hops that are dried in the sun lose their rich flavour, and, if under cover, they are apt to ferment and change with the weather, and lose their strength; moderate fire preserves the colour and flavour of the hops, by evaporating the water, and retaining the oil of the hop. After the hops are taken from the kiln, they should be laid in a heap, to acquire a little moisture to fit them for bagging. It would be well to exclude them from air by covering them with blankets. Three or four days will be sufficient for them to be in that state. When the hops are so moist that they may be pressed together without breaking, they are fit for bagging. Bags made of coarse linen cloth, eleven feet in length, and seven in circumference, which hold about two hundred pounds weight, are most commonly used in Europe: but any size that best suits may be made use of. To bag hops, a hole is made through the floor of a loft, large enough for a man to pass through with ease. The bag must be fastened to a hoop, larger than the hole, that the floor may serve to support the bag; for the convenience of handling the bags, some hops should be tied up in each corner of the bag, to serve as handles. The hops should be gradually thrown into the bag, and trod down continually, till the bag is filled. The mouth of the bag must then be sown up, and the hops are then fit for market. The closer and harder hops are packed, the longer and better they will keep; but they should be kept dry. In most parts of Great Britain where hops are cultivated, they estimate the charge of cultivating one acre of hops at forty-two dollars, for manuring and tilling, exclusive of poles and rent of land; poles they estimate at sixteen dollars per annum, but in this country they would not amount to half that sum; one acre is computed to require three thousand poles, which will last from eight to twelve years, according to the quality of the wood used. The English growers of hops think they have a very indifferent crop if the produce of one acre does not amount to one hundred and thirty-three dollars, but, much more frequently, it amounts to two hundred dollars, and sometimes so high as four hundred dollars per acre. In this country, experiments have been equally flattering. A gentleman in Massachusetts, in the summer of 1791, raised hops, from one acre of ground that sold for three hundred dollars; it is allowed, that land in this state is equally favourable to the growth of hops. Upon a low estimate, we may fairly compute the nett profit of one acre of hops to be eighty dollars, over and above poles, manure, and labour; and in a good year a great deal more might be expected. There is one circumstance further we think has weight, and ought to be mentioned: in the English estimate the expense put down is what they can hire the labour done for by those who make it their business to perform the different parts of the cultivation. A great saving may, therefore, be made by our farmers in the article of labour, for much of it may be performed by women and children. Added to this, we have another advantage of no small moment in this country: the hop harvest will come between our two great harvests, the small grain and Indian corn, without interfering with either but in England the case is otherwise: the small grain and hop harvest come in together, and create a great scarcity of hands, it being then the most busy season of the year. It is found, by experience, that the soil and climate of the eastern states are more favourable to the growth of hops than Great Britain; they not being so subject to moist, foggy weather of long continuance, which is most injurious to hops; and the southern and middle states are still more favourable to the growth of hops than the eastern states, in point of flavour and strength. The State of New-York unites some advantages from either extreme of the union. The cultivators of land in this state have every inducement, which policy or interest can offer, to enter with spirit into the cultivation of hops; as we shall thereby be able to supply our own demand, which is now every year increasing, instead of sending to our neighbours for every bag we consume; a circumstance the more unaccountable, as hops, are on all hands, allowed to be one of the most profitable crops that can be raised; the culture requires but little land, the labour may be performed at intervals, so as not to interfere with other business of the farm, and be generally performed by women and children. There is hardly a farmer in this state but may, with ease, raise from one quarter of an acre, to as much as three or four acres, the advantage of which would, in a few years, be most sensibly felt both by the individual concerned, and the state at large. In the city of New-York there are, at present, a number of large and respectable breweries, and new ones, from time to time, may reasonably be expected to be added to their number. All these establishments are now supplied with hops from Massachusetts and Connecticut; these considerations should certainly stimulate a few spirited cultivators to lead the way, and raise hops; their laudable example would soon be followed by others; so that in a few years we should have prime hops of our own in abundance, for home consumption or exportation. This subject will, I hope, appear sufficiently important to recommend itself; to say more is therefore unnecessary. [5] Of the different kinds of hops, the long white is the most esteemed; it yields the greatest quantity, and is the most beautiful. The beauty of hops consists of their being of a pale bright green color. Care should be taken to obtain all of one sort; but if different sorts are used, they must be kept separate in the field, for there is a material difference in their time of ripening; and if mixed in the field, will occasion extra trouble at the time of gathering them in. [6] Hops must be dressed every year, as soon as the frost will permit; on this being well done depends, in a great measure, the success of the crop. It is thought by many to be the best method to manure the hop yard in the fall, and cover the hills entirely with the manure, asserting, with other advantages, that this prevents the frost from injuring plants during the winter. Hops had better be gathered before they are full ripe than remain till they are over ripe, for then they will lose their seed by the wind, or on being handled. The seed is the strongest part of the hop, and when they get too ripe will lose their green colour, which is very necessary to preserve as the most valuable part of the [remainder of text is illegible] [7] Kilns covered with the splinters of walnut, or ash, will answer the purpose, and come cheaper than hair cloth. _Barley Cultivation._ However unconnected this subject may appear with a treatise on brewing, I cannot help thinking that, in this country, it is much more intimately connected with it than one would, at a first view, incline to suppose, and for the following reasons; first, Because the proper cultivation of barley is not generally known, save in the eastern states, and but very little raised in any of the others; secondly, Without good barley it is impossible to make good malt, consequently, good beer--and it must be acknowledged, that a great proportion of the barley that is raised, even in the eastern states, is but very imperfectly suited to the purposes of the brewery, being what is termed winter barley, and generally a poor, thin, lank grain, by no means qualified to make good malt. This is so well known in England, that it is very rarely met with in the barley markets, and seldom, or ever, purchased by a brewer. The summer, or spring barley, always getting the preference, being the largest bodied grain, and, of course, the best suited to the purposes of making prime malt, the want of which, is frequently severely felt by the brewers of this country, from the impossibility they often find themselves in of procuring good barley, being obliged to use such as they can get, which, for the most part, is very ill suited to their purpose. It will be, then, their interest to give every encouragement to the farmer to raise spring barley in preference to the winter, to procure the best seed, of that description, that he can find, to clean it well, to steep it in well or spring water for twelve hours, stirring it frequently from the bottom of the tub or vessel all around; and previous to each stirring, all the floating grains, seed weeds, &c., should be carefully skimmed off: thus nothing will remain for seed but sound and perfect grain. The first water should be drawn off at the end of six hours, and immediately replaced by fresh; this again drawn off at the end of six hours more; it should be sown, broad cast, the following day, being first previously mixed with a sufficient quantity of wood ashes to dry it as much as will be necessary for the purpose of sowing. Thus managed, if the ground be in proper tilth, and fitly prepared, this grain will make its appearance the fifth or sixth day after sowing; whereas, if the seed be sown dry, it will probably be three weeks or more before it comes up, particularly if the season be dry. I cannot more forcibly recommend this practice than by giving a brief sketch of an experiment made in England, and taken from the Bath and West of England Society's reports. A farmer selected four acres of the same field, treated and prepared it for seeding exactly in the same way, he then divided it into two equal parts; he sowed one part with dry seed, in the common way, the other with steeped seed, as here recommended, and the consequence was, that the latter produced a double crop, although the seed in both cases was the same, save the difference of treatment. The superior quality and condition of the crop seemed to keep pace with the increased quantity. The beginning or middle of March, if the weather be dry, is the best time to sow spring or summer barley. This mode of preparing seed wheat, is highly recommended as an assured preservative against the smut, fly, &c., insuring a sound good crop of grain. Barley should be always cut in dry weather, yet not suffered to be too ripe before cutting; stacking it in the field for a few weeks before removing it to the barn, helps and prepares it for malting, by sweating and drying it. Barley, immediately brought to the malt house from the field, rarely makes good malt, as a great proportion of it becomes staggy, and will not grow. Those who can corroborate the truth of these remarks, and sufficiently appreciate them, will readily justify and excuse this seeming departure from the original plan of this little work. _Table Beer._ There is no production of the brewery more important to society than good table beer, whether it be considered as a diluent to animal food, or a diet drink in fever cases, even of the most malignant kind, where, to my knowledge, it has been preferred to all others, and that with the greatest success, sanctioned by the advice of some of the most eminent physicians. This justifies my recommending it, and giving several processes for making this useful liquor. _Small Beer for Shipping._ 12 Bushels of Pale Malt. 12 Bushels of Amber Malt. -- 24 -- 14 lb. of Hops. Cleansed 24 Barrels. Let your malt be fine ground; first liquor 172; mash one hour, stand one hour, run down smartly; beat of second mash 180; mash one hour, stand two hours, boil two hours; making your length sufficiently long to give one barrel of beer to each bushel of malt. Pitch your tun at 70 degrees, giving one gallon of solid yest; cleanse within twenty-four hours. The fresher this beer is sent out the better: being very thin in body and low priced, it cannot be expected to last long. _Keeping Table Beer._ PROCESS. Commenced brewing at six in the morning, heat of the air 60 degrees, per Fahrenheit's Thermometer. 48 Bushels of Pale Malt. 16 Bushels of Amber Malt. -- 64 -- 72 lb. of Hops. Cleansed 45 Barrels of Table Beer. 10 lb. liquorice ball, which was previously melted down in boiling water, by frequent stirring, to a liquid, and then put in with the hops when added to the worts. Ran the necessary quantity of boiling water into the mash tun for the first mash, and when cooled down to 168, commenced mashing, which continued three quarters of an hour, stood one hour, ran down briskly; mashed a second time at 180, for half an hour; stood half an hour; mixed both worts, boiled one hour and a half as hard as possible, throwing into the copper, before boiling, half a pound of ground ginger, with half a pound of ground mustard; pitched these worts at 70 degrees, giving 3 gallons of solid yest; remained in the tun 36 hours, and was headed over, before cleansing, with four pounds of flour and one pound of salt mixed together. This kind of beer will have attenuated sufficiently in from 30 to 36 hours. _Small Beer of the best kind, how brewed, which, in a good cellar, will keep as long as can be reasonably wanted._ MATERIALS. 15 bushels of Pale Malt. 7 lb. Hops. Cleansed 10 1/2 Barrels Beer, heat of the air 50 by Fahrenheit's Thermometer. Boiled the first copper; drew the fire; then ran ten inches of boiling hot water into the keeve; added two inches of cold water, mixed both well together, which made up at 168; then put in the malt gradually, mashing all the time, for about half an hour; the mash being thin, did not require a longer operation. Before mashing, rubbed the 7 pounds of hops in a tub, sprinkling over them, when rubbed, about one quarter of a pound of white salt, then poured on boiling water in sufficient quantity to saturate them well, after which they were close covered; the keeve having stood two hours, the tap was set, and ran down twelve inches. Did not boil the second copper, but raised its heat to 184, mashed a second time, and stood one hour, ran down as before, and completed the length in the underbank, cleared the copper, had it rinced out, got up the worts, put in the hops, extract and all, made up the fire, and boiled one hour and a half as hard as possible, previously adding to them four pounds of brown sugar that had been dissolved in a bucket with hot water, also half a pound of ground mustard; this beer remained on the coolers about eight hours, pitched it next morning at 72 degrees, adding only one gallon of solid yest, ran slowly into the tun which made up at 61 degrees; came on gradually, remained in the tun 31 hours, and raised to 66, affording but two degrees of attenuation. Notwithstanding this beer worked well in the casks, yet moderately, was frequently filled at close intervals, and was glass fine the fifth day. The sugar was added to assist the colour as well as the strength, the mustard to give flavour. _Another Method._ To brew small beer somewhat stronger, take 30 bushels of pale malt, (have it ground fine,) 10 pound of hops, steep them as in the preceding process. Turn out of your copper 16 barrels of beer, give your first liquor at 165, your second at 175, mash, run down, stand, and boil as before. But before you commence brewing, take five pounds of brown sugar, put it into a metal pot with some water, set it on the fire, keep it constantly stirring till it begins to smell strong, then take it off the fire, and add to it, gradually, three gallons of water, at the temperature of blood heat, stirring the water and the sugar well together, till the whole be perfectly blended; this prepared liquor should be added to the worts in the copper before boiling. The fermentation, &c., to be conducted as before, save only the pitching, yest, to be increased by half a gallon, which half gallon is not to be added to the worts until twelve hours after the first gallon. Attenuation should proceed until the heat rises four degrees above the pitching heat, which should be the same as in the preceding process. In both instances, the tuns should be covered during the period of fermentation, but taken off for the purpose of rousing before cleansing; these covers should be put on again, in order to prevent the dispersion or waste of the gasses, which is always a loss of spirituosity. _A good sound keeping Table Beer may be Brewed from wheaten Bran and Shorts, and, in many situations, when Malt cannot be procured, would be found an excellent substitute. This process is well worth the attention of housekeepers._ PROCESS AS FOLLOWS: 40 Bushels of Shorts. 20 Bushels of Bran. 16 lb. of Hops will give 25 Barrels of Small Beer. Boil your first copper, run into your mash tun as much boiling water as, when reduced with cold, will bring it to the temperature of 1.0, then commence your mashing operation, putting in two bushels of shorts, and one bushel of bran at a time; when these are well mixed with the water, put in more, mash again, and so continue to do till all is in; it will take from half an hour to three quarters to mash this quantity properly; let your mash stand two hours, run down as in the preceding processes, and give your second liquor 165; mash a second time, stand one hour, boil your first wort one hour very hard with half your hops, which should have been steeped, rubbed, and salted, as before directed; boil your second wort one hour and a half in the same way, putting on the remainder of your hops, with one pound of ground mustard, and five pounds of brown sugar, reduced, by boiling, to a colouring matter, as already directed in the previous process; make up your two boilings in your tun at the heat of 65, giving three gallons of solid yest; let your attenuation proceed ten degrees, or to 75, then cleanse, and continue to fill your casks in the usual way. It has been found that beer brewed from these materials has stood the summer heats much better than beer brewed from malt alone; this may be accounted for by the extract of malt possessing a much larger proportion of saccharine matter than that obtainable from bran and shorts. In families, this beer may be brewed in the proportion of one or two barrels at a time; and in the country, where brewer's yest may not be procurable, leaven, diluted with blood-warm water, may be substituted for brewer's yest, and will answer, but not so well; neither will attenuation go so high, as fermentation with leaven, when applied to liquids, is generally languid and slow. _Single Ale and Table Beer._ 100 Bushels of Malt. 60 lb. of Hops. Heat of the air 50 degrees. Cleansed or tunned 30 Barrels of Single Ale; with 16 Barrels of Table Beer after. First, or mashing liquor, 168, run your whole quantity of boiling liquor into your mash tun, and when it cools down to the above point of 168, begin to run in your malt gradually from your malt bin; this quantity will require four or five hands to mash it well, which will generally take three quarters of an hour; when sufficiently mashed, cover your tun, let it stand two hours; run down this first mash smartly by two cocks within the hour; let your hops be rubbed, steeped, and salted, as before directed; added to these worts, as they began to boil, three gallons of the essentia bina or liquid colouring, with one pound and a half of ground mustard, and one pound of liquorice root finely powdered, boiled the whole two hours as hard as possible, there being a second copper for this operation, there was liquor prepared for the small beer and run on the keeve at the heat of 185; mashed well a second time, and stood two hours; by this time the first wort was let run into the hop back, and so on the cooler. After which, ran down the small beer, got it into the small copper, adding about six hand buckets of the hops that had been boiled on the single ale; these answered to preserve the beer, with one pound of ground mustard to assist flavour, and two gallons of the essentia bina to give colour; boiled the small beer one hour smartly. The strong worts were let into the tun in three portions, there being three coolers; the first division, at 65, had two gallons and a half of yest given to it; the second, at 66, the same quantity of yest; the third, at 65, was let down without yest, when all were in the tun made up at 64; in thirteen hours the tun had a handsome appearance of work; came on regularly, and attenuated to 76, having gained 12 degrees within sixty hours, then cleansed and filled the casks every three hours for the first eight fillings. Thus managed, this single ale was fit to send out the fifth day after brewing. When this ale is racking off the butts, to be sent out, would recommend putting two ounces of ground rice into each barrel which will create briskness, and much improve the beer. Ran the small beer into the hop back of the strong beer, and so on the coolers, thereby giving it a chance to lick up all the strong ale it met with in its progress to the tun, which it entered at 65 with three gallons of yest, and was cleansed within thirty-six hours. The quantity of beer here mentioned would be much improved by the addition of six or seven pounds of brown sugar or molasses; but if good table beer is wanted, it can be only obtained from whole grists of malt, and is well worth the difference of expense to those who can afford it, and appreciate quality. _Strong Beer._ Brewed, November, 1810, the following materials. Heat of the air 50 degrees. 40 Bushels of Pale Malt. 20 Bushels of Amber Malt. -- 60 -- 40 lb. of Hops, the best quality. Cleansed 20 Barrels of Beer. Rubbed, salted, and steeped the hops, as already directed, in a close vessel, ran a sufficient quantity of boiling water on the mash tun for the first mash, which was suffered to cool down to 165; mashed well for nearly one hour, stood two hours; ran down smartly, boiled the first wort one hour very hard, with about half the hops; mashed a second time at about 185: took about half an hour in the operation, ran down smartly after two hours' standing, got up this second mash smartly into the copper, taking the necessary precaution of rincing the copper out clean, for the reception of the second wort, which was boiled two hours very hard, with the remainder of the hops; these two worts were run together on the same cooler; after standing a few hours, were run on a second cooler, and there suffered to remain till they came down to 65; were then let into the tun, with two gallons of solid yest, by a large plug hole in a few minutes so as to have scarcely suffered any diminution of their heat; in twelve hours after, there was added two gallons more of yest, roused the tun a second time, came on gradually, and attenuated within 56 hours ten degrees, and so was cleansed at the heat of 75, this beer was filled every two hours, for the first twenty-four, and in a few days more became transparently fine; this beer should have added to it, before sending out, four ounces of steeped hops, and two ounces of ground rice to each barrel; the five pounds of hops wanted for this operation is previously put to steep in a clean tub with some of the beer. This beer, if thus brewed with good materials, and treated as directed, will be found to give satisfaction. During the winter half year, the fermenting tun should be always covered; in summer, only partially so; the less strong beer is attempted to be brewed in that season the better, as it will not keep, necessity alone should compel the brewer to work, in this country, during the summer months; and then at small beer only. _Table Beer, English method of brewing it._ Take 8 bushels of Malt, and 6 lb. of Hops. This quantity of materials should deliver four barrels of beer. First liquor 161; mash the first time one hour. Second liquor 170; mash the second time half an hour. Third liquor 152; mash the third time twenty minutes. Boil the three runnings together for two hours in a close covered copper; three pints of good solid yest will be sufficient to pitch this quantity, mixing it, before adding, with about one gallon of the wort, then add this to the rest; a low attenuation for this kind of beer will not answer, the specific gravity being too light, the fermentation rarely exceeding 30 hours in the tun. It being generally wanted for immediate use; it is pitched high, and worked quick. It is further important to bung it down close as soon as it has done working. This kind of beer may be securely and advantageously administered to fever patients, instead of other drink: I have known it to be attended with the happiest consequences. _Unboiled beer, how Brewed._ The following process, I confess, I never myself tried, but, from the manner it was spoken of by the party giving it, I would strongly recommend a trial of it on a small scale, at first, until its advantages and superiority was well ascertained over the old and long established mode of boiling wort. Mash your full complement of malt, or rather one third more, and that in the usual way, (suppose you are brewing strong beer,) and while your mash stands, let your copper have as much cold water run into it as will save it from burning; rouse your fire, salt and rub your hops, as recommended in previous processes; let their quantity be increased one third more than if brewed in the ordinary way; and when got into your copper, cover close, and let these hops simmer for two hours, _but not boil_; then run down your first wort in sufficient quantity as, when added to the water and the extract of the hops, will give you the length you contemplate; you will observe the malt is increased to meet the quantity of water in the copper; but this cannot be considered a loss, as the second mash will answer for single ale, or good table beer; the hops in the same way. When you have got your intended complement of strong wort in your copper, rouse it well, cover close, and let your copper stand two hours more, keeping up a moderate fire just enough to make it simmer _but not boil_; during this time your second mash may be going on with water from your second copper; this, as already stated, will make single ale, or good table beer; if the latter, it may be boiled in the usual way, but not longer than half an hour, on account of the increased quantity of hops; which hops should be all retained in the copper after the first worts are run off, by means of a strainer placed at the mouth of the cock hole; one hour strong boiling will be sufficient for the succeeding wort, if single ale be wanted; the remainder of the process for both worts is the same as already directed for such quality of drinks. It was further stated to me that unboiled beer will appear very turbid and unpromising for some time after it is brewed, and will take three months at least to come round; but that after that period it will improve rapidly, and become transparently fine; when second worts are found too weak, they may be assisted with good Muscovado sugar, of which eight pounds is considered equivalent to one bushel of malt. In fact, pleasant beer might be made from sugar alone, without any malt. _Strong Beer, of an excellent quality and flavour, brewed from the extract of the Hop only, rejecting the substance._ This extract was obtained by the hot infusion, in a close covered wooden vessel set to infuse the evening before brewing; in this process one third more hops should be allowed; these hops need not be wasted, as they will answer well for table beer, or single ale, brewed according to the preceding processes; but, in either case, one hour's strong boiling will answer for single ale, half an hour for table beer will be sufficient, on account of the increased quantity of hops. When you have got up your first wort in your copper, that you intend to preserve with extract, boil the first half hour without it, and one hour with it, very hard in both instances. It should have been mentioned that, in preparing your first, or mashing liquor, two pounds of rice is to be added to your water in the copper before boiling, supposing the length of your brewing 20 barrels, or in that proportion. Strong beer brewed with the extract alone, as here recommended, has turned out remarkably well, and if the hops are good, will be found more delicately flavoured than other beer; supposing the malt alike good. Pitching, cleansing, and filling, to be conducted as already recommended in preceding processes, with the tun close covered during the fermentation. _Table Beer._ Table beer, of a superior quality, may be brewed in the following manner, a process well worth the attention of the brewer, the gentleman and the farmer, whereby the beer is altogether prevented from working out of the cask, and the fermentation conducted without any apparent admission of the external air. I have made the scale for one barrel, in order to make it more generally useful to the community at large; however, the same proportions will answer for a greater or less quantity, only proportioning the materials and utensils. Take one peck of good malt ground, one pound of hops, put them in twenty gallons of water, and boil them for half an hour, then run them into a hair cloth bag, or sieve, so as to keep back the hops and malt from the wort, which, when cooled down to 65 degrees by Fahrenheit's thermometer, add to them 2 gallons of molasses, with one pint, or a little less, of good yest, mix these with your wort, and put the whole into a clean barrel, and fill it up with cold water to within four inches of the bung hole, (this space is requisite to leave room for fermentation,) bung down tight, and if brewed for family use, would recommend putting in the cock at the same time, as it will prevent the necessity of disturbing the cask afterwards; in one fortnight this beer might be drawn, and will be found to improve to the last. _Fermenting and Cleansing in the same Vessel._ The following recommendation to brewers is well worth their attention, that is, to ferment their strong, or what they call their stock beer, in the vat they propose to keep it in, until fit to turn out; this practice will be found advantageous to the flavour and preserving quality of such beer, as close fermentation has a decided preference over what is termed open. One or more workers may be placed in the side of such vat, a few inches above the surface of the enclosed liquor; thus the head as it rises will have the opportunity of running off; such fermentation should further be conducted coolly and slowly, the pitching heat, in this case, should not exceed 60 degrees of Fahrenheit, and the yest one third in quantity less than if applied in open vessels, but the yest should be mixed with a double quantity of the wort at 65, in a separate vessel before pitching. When vats are wanting, the operation may be conducted in hogsheads or butts, allowing a tin or wooden worker to each cask. In brewing small quantities of strong beer, this contrivance supersedes the necessity of fermenting tuns, or troughs, no small saving of expense, whilst it makes the beer more spiritous and preserving. The annexed plate shows the form and application of the worker, whether of tin or wood. [Illustration: A The cask in which the worker is placed. B The spout of the worker, which takes off the yest. C The plug at the angle of the worker to admit the pipe of a tundish, in order to fill the cask as it works.] _Another Method of fermenting Strong Beer that might be expected to produce a pure and excellent liquor._ Mash, run down, and boil in the usual way, suffer your worts, after drawing your fire, to remain on your copper two hours, doors and hatch open. If in winter, the deeper your worts lie on the cooler the better; when they have come down to the proper heat of pitching, give your yest to them on the cooler, mixing it gently with the whole guile, and when properly headed with yest, which will probably happen within twenty-four hours, run off your worts gently into barrels, leaving your top and bottom yest on the cooler undisturbed, till all the cooler is cleared; but previous to running your worts into the barrels, put half a pint of good solid yest into each, and when full, clap your tin workers into the bung holes, and so let it finish its fermentation for about a week longer, filling the casks occasionally as they work. When done working, bung down or vat them; if you wish to add any kind of flavouring substance to this beer, the best time to do it is at commencing the second fermentation, experience teaching that all fermented liquors should have such substances added to them during, or at the commencement of their fermentation, which is preferable to adding these substances in the boil; I mean spices, and delicate flavouring substances. _Process of Brewing Windsor Ale on a small scale._ Windsor ale is a very pale, light, agreeable ale, as fine as wine, and unquestionably the best fermented of any malt liquor sent to the London market. Length drawn, three barrels per quarter of eight bushels, the malt pale, with two pounds of hops of the first quality; heat of the first liquor 182, two barrels of which is generally allowed to each quarter of malt, for the first mash; one barrel per quarter for the second; the same quantity for the third is as little liquor as can be dispensed with in three mashings; for short liquor and stiff mashes are essential to this quality of ale, in order to leave as little as possible in the copper for evaporation on account of the short boiling. Mash quick, run down quick, get your wort as fine as possible into your underbank; let your first mash stand two hours, your second one hour and three quarters. Give your second mashing liquor at 190; if you mash a third time, give your liquor at 175; stand half an hour; these worts should be pitched from 52 to 60, but not higher. The mode of doing so is also different from the generality of other malt liquor; your yest should be fresh, smooth, and solid. Begin yesting this ale a few barrels at a time, and when that has caught, add the remainder gradually, in about 48 hours, or from that to 60. This guile of ale will assume a close head of yest, which should be carefully skimmed off as fast as it forms after the first skimming: by this is not meant the first or worty head formed soon after the yest has taken, but the close yesty head already mentioned, which usually takes the time stated, say from 48 to 60 hours, when no more yest rises, and the guile remains quite flat; you will find the heat you pitched at, say 56, 58, or 60 degrees will by this time have increased to 80, or even more, and the specific gravity of the wort diminished from 26 or 27 pound per barrel, to six or seven pound per barrel; this attenuation will give it all the pungency and spirituosity it stands in need of. At this time your cleansing operation commences; after which it will work but little in the casks. It should be filled regularly every two or three hours, after cleansing, for the first twenty-four. After it has done working, you should immediately start it into an air-tight vat, with about one pound of hops well rubbed to every three barrels of ale in your brewing; if you use spent hops, such as has been boiled on the first mash, you may use a greater quantity, say half a pound more to each three barrels of beer, taking the precaution that they are become quite cool. This ale, thus treated, will be found glass fine in the course of a fortnight, and fit to be racked off into hogsheads or barrels. It will improve by age both in flavour and quality. But it should not be boiled more than fifteen minutes. _Reading Beer, how made._ Reading beer is made in a town of that name about thirty miles distant from London; the quality of its beer is much spoken of, the mode of brewing it is stated to be as follows: Scale of Brewing, suppose 22 Barrels. 80 Bushels of Pale Malt. 98 lb. of Hops. 3 lb. of Grains of Paradise, pounded or ground. 5 lb. of Coriander Seed, do. 14 lb. of the best brown Sugar. Your malt should be some days ground, and if exposed on an open loft, after grinding, so much the better. Boil your first copper, run on your mash tun till you have your complement, then occasionally rouse your water with your mashing oars, or dashers, till you get it down to 175: put your malt in slowly, for fear of setting; keep mashing all the time, which should be continued full one hour, stand two hours, run your worts, when you set tap, as fine as you can get them into your underbank; this you will effect by drawing off successively five or six buckets of the first run, and throwing them over your grains in the mash tun; when you perceive they come off glass fine, lay by your bucket. Give your second mashing liquor at 178 degrees, mash three quarters of an hour, stand one hour. Give your third liquor at 158, mash half an hour, stand one hour; boil your first copper of worts, which should take the half of your three runs, one hour as hard as you can; your second, two hours in the same way; run the two boilings into one cooler, and pitch at 64, giving one gallon of solid smooth yest; skim off the yest, as in the case of Windsor ale, until the attenuation rises to 80 degrees, which will have advanced it, from the pitching heat of 64, sixteen degrees. Before you commence the operation of cleansing, mix one quarter of a pound of bay salt, with half a peck of malted bean flour, scatter this mixture over the surface of your tun, rouse well, cleanse, and fill in the usual way. _Two-penny Amber Beer, as brewed in London._ This beer is in great demand, and large quantities of it consumed, and is supposed more profitable to the brewer than any other species of malt liquor, it being generally brewed, drank, and paid for within the fortnight. PROCESS. 200 Bushels of Pale Malt. 112 lb. of Hops. 20 lb. of Liquorice Ball 30 lb. of Molasses, 4 lb. of Grains of Paradise, ground. Cleansed 81 Barrels. Heat of first mashing liquor 169; mash one hour, stand two hours, run down smartly; specific gravity of this wort 26 pound per barrel; second mash 170, mash half an hour, stand one hour, run down as before; specific gravity of this wort 11 pound and a half per barrel; third mash 160, mash twenty minutes, stand half an hour; gravity six pound per barrel; divide these three runnings into two boilings; boil the first copper for three quarters of an hour, the second one hour, in both cases as hard as possible; the hops and other ingredients should be put in at the first boil, and so retained in the copper by means of a strainer; pitch these worts at 64 degrees, giving two gallons of solid yest at first, with two gallons more in twelve hours after: remained in the tun about 60 hours, or until its attenuation reached 80 degrees; used over the surface of the tun, before cleansing, four pound of ground ginger, half a pound of bay salt, and about half a peck of wheaten flour, mixed all together, and scattered over the surface of the tun; roused well, and cleansed 81 barrels. This quality of beer, when brewed from good materials, and managed as directed, makes a wholesome and a pleasant beverage; but, to do it justice, should have more time allowed it for coming to perfection. _London Ale, how brewed._ Ale is, of all other malt liquor, the most delicate, and will bear less tampering with. It will therefore require your nicest care through every part of the process. Transparency, pungency, and flavour, are qualities that highly recommend this liquor, and should be particularly aimed at by the brewer. Hard water is, by some, supposed to be more favourable for making this kind of ale than soft. Heat of the air 60 degrees. 200 Bushels of Pale Malt 206 lb. of Hops. 4 lb. of Grains of Paradise, pounded or ground. 4 lb. of Coriander Seed, do. 1 lb. of Orange Powder, do. Cleansed 65 Barrels of Beer. First mash 173, mashed one hour, stood one hour, ran down smartly; specific gravity of this wort 32 pounds per barrel; the heat appears more favourable for obtaining the whole sweet of the mash than the preceding one by six pounds per barrel, an object well worth the attention of the brewer; second mash 172, specific gravity of this wort 22 pounds per barrel; mashing, standing, &c., the same as in the preceding process; boiled the first wort one hour; the second wort two hours, very hard in both instances; pitched the tun at 62 degrees giving two gallons of yest at first, and two gallons twelve hours after. Remained in the tun about 80 hours, or until it attenuated to 74, or twelve degrees over the heat it was pitched at; used over the surface of the tun, at cleansing, four pound of ground ginger, half a pound of bay salt, with half a peck of wheat flour well mixed, roused the tun well. You should observe, in working amber beer, to cleanse with the sweets on, but in ale you should work it low in order to get the sweets off. This ale should be carefully filled as it works and closely attended to until done working; then put into each cask, if of a large size, two handfuls of spent hops, that have been previously cooled, and but a short time boiled; then bung down, and it will be fit to send out. _Windsor Ale, brewed on a large Scale._ This ale has experienced so great a demand in London and its vicinity for a few years back, as materially to affect the London pale beer brewery; it is a liquor better calculated for winter than the summer season. The London brewers have been induced to brew on the same principle, and in many instances they exceed the original. Here follows the London process for brewing this kind of beer, which, I apprehend, will be well worth the American brewers' imitation, as good ale is a species of malt liquor rarely met with in this country. 200 Bushels of Pale Malt. 224 lb. of Hops. 40 lb of Honey. 4 lb. of Coriander Seed, ground. 2 lb. of the Grains of Paradise, ground. 65 Barrels Cleansed. Procure your hops of the best quality, rub them in one or more large tubs, pour cold water on them in sufficient quantity to wet them all over, and so let them infuse till the next day, which should be the day on which you brew. When your first copper has just boiled, run a sufficient quantity of water into your mash tun for your first mash; and when this has cooled down to 176 degrees, run in your malt slowly, and mash well for one hour and a quarter; after which, let your mash tun stand two hours, run down smartly and fine; keep your mash tun close covered from the time you have done mashing till you begin to set tap; give your second mashing liquor at 186, mash one hour, stand one hour, run down as before; give your third liquor for the last mash at 160, mash one hour, stand one hour run down as before; divide these three worts into two parts, boil your first copper one hour, putting in your ingredients with your hops, save the 40 pounds of honey, which should be reserved to be put into the copper a few minutes before striking off; rouse your copper well at the time of putting in the honey, and continue the same till run off, otherwise, it will pitch to the bottom of the copper, and likely be the cause of burning; your second worts should boil two hours on the same hops and ingredients, which should be retained in the copper by a strainer, pitch your tun at 62 degrees, giving two gallons of good yest at first, and two gallons more in twelve hours after; let your fermenting heat rise to 80 degrees; thus your attenuation will have gained 18 degrees, which will probably cause your guile to remain in the tun from 60 to 80 hours. Use salt and bean meal flour as directed in the preceding process, and in the same proportion, before cleansing; fill, &c., as already directed. _Welsh Ale, how brewed._ This it a luscious and richly flavoured ale, much liked, but very heady. PROCESS. 72 Bushels of Pale Malt. 70 lb. of Hops. 20 lb. of best brown Sugar. 2 lb. of Grains of Paradise, ground. Heat of the first mashing liquor 175, mash one hour and a half, putting in your malt very gradually, and mash uncommonly well, and let it stand two hours; second liquor at 190, mash one hour, and stand two more; run down as before, boil these two runs together for one hour and a half, putting in your hops, &c., save the sugar, which is to be put in but a few minutes before striking off, at which time the rousing of the copper should commence, and so continue until the worts are nearly run off. Small beer may be brewed, in the usual way, after both these worts, in which case, cold water will answer full as well as hot; pitch your strong worts at 62, with a small proportion of good yest, and let your fermenting heat rise to 80; thus your attenuation will proceed 18 degrees; cleanse with salt and bean flour as already directed, but in suitable proportion in point of quantity to your malt, fill in the usual way, and when nearly done working, use fine ale to top with, before you bung down, putting into each barrel one large handful of scalded hops, that have been previously cooled down. _Wirtemberg Ale._ BREWED AS FOLLOWS: 128 Bushels of Pale Malt. 32 Bushels of Amber Malt. --- 160 Bushels of Malt. --- 188 lb. of Hops. 28 lb. of Honey. 20 lb. of Sugar. 4 lb. of Hartshorn Shavings. 4 lb. of Coriander Seed, ground. 1 lb. of Caraway Seed, ground. Cleansed 50 Barrels of Ale. Give your first mashing liquor at 172, mash for one hour and a half, stand two hours, run down fine, but smartly. Second mashing liquor 180, mash one hour, stand two hours, run down as before; get up your two worts; put in, with your hops, the other ingredients, save the honey and sugar, which is to be put into your copper but a few minutes before striking off, rousing your copper while any wort remains in it. This ale should be boiled hard for one hour and a half; pitch your tun at 62, raise your fermenting heat to 80, which will generally rise in the course of 70 hours. Give of good solid yest four gallons, two gallons at first, and two gallons more in twelve hours after, rouse your tun each time. _Hock._ This is a beer that has within a few years had a great run, particularly in Germany. PROCESS AS FOLLOWS: 112 Bushels of Pale Malt. 48 Bushels of Amber Malt. --- 160 Bushels. --- 206 lb. of Hops. 4 lb. of Cocculus Indicus Berry, ground. 2 lb. of Fabia Amora, or Bitter Bean. 20 lb. of Brown Sugar, of good quality. Cleansed 54 Barrels. First liquor 176, mash one hour and a quarter, stand one hour and a half; second liquor 182, mash one hour, stand two hours; when both worts are in the copper, add your hops and other ingredients, except the sugar, which is to be put in as already directed a little time before striking off, boil two hours and a quarter as hard as you can. Pitch your tun at 64, giving four gallons of solid yest at once, and cleanse the second day, or in forty-eight hours; fill as already directed, and put into each barrel one handful of fresh steeped hops before bunging down. _Scurvy Grass Ale._ This species of ale is considered a great sweetener of the blood, has been much approved of, and is strongly recommended as a wholesome and pleasant medicine. PROCESS AS FOLLOWS: 40 Bushels of Pale Malt. 25 lb. of Hops. 10 lb. of Molasses. 2 lb. of Alexandrian Senna. 5 Bushels of Garden Scurvy Grass. Cleansed 14 Barrels of Ale. Your malt should be fine ground; give your first liquor at 170, mash one hour, stand one hour; heat of your second liquor 172, mash three quarters of an hour, stand one hour; give your third mashing liquor at 160, mash twenty minutes, stand half an hour; these three worts should be run into your copper together, and boil together for one hour gently, for one quarter of an hour more as hard as you can; all your ingredients to be put in with your hops, except the molasses, which should only be put in a few minutes before striking off; from the time you put in your molasses, keep stirring your copper until its contents is nearly off. About the middle of your fermentation, procure one pound of horse-radish, wash it well, dry it with a cloth, after which slice it thin, and throw it into your tun, rousing immediately after; when done, replace your tun cover, pitch your worts at 66 degrees, with about two gallons of solid yest; cleanse the third day, with the sweets on. This ale is drank both hot and cold. _Dorchester Ale._ This quality of ale is by many esteemed the best in England, when the materials are good, and the management judicious. 54 Bushels of the best Pale Malt. 50 lb. of the best Hops. 1 lb. of Ginger. 1/4 of a lb. of Cinnamon, pounded. Cleansed 14 Barrels, reserving enough for filling. Boil your copper, temper your liquor in the same to 185, and when ready, run it on your keeve a little at a time, putting in the malt and the water gradually together, mashing at the same time; when the whole of your malt is thus got in, continue the operation of mashing half an hour, cap with dry malt, and let your mash stand one hour and a half. Second liquor 190, mash three quarters of an hour, stand two hours; in both mashes get your worts as fine as you can into your underbank; rub and salt, before mashing, 30 pounds of your hops; infuse them in boiling water before mashing, and let the vessel containing them be close covered. The other twenty pounds of hops should have been rubbed the evening before brewing, but not salted, put into another close vessel, covered with boiling water, and there suffered to digest for 12 hours: at the time of putting the hops in your copper, the extract, in both cases, is to be added; but the first 30 pounds of hops in substance _only_ to be added; these, with the two extracts will be sufficient for the brewing; the remaining 20 pounds of hops will answer for single ale, or table beer, but should be used on the same day. Your worts being now in the copper, with the hops and extract, boil hard for one hour; after which, draw your fire, open your copper and ash-pit doors, and so let it stand one hour, then strike off gently on your cooler; when your worts are cooled down to 55, prepare your puncheons, suppose four, containing four barrels each; see that they are dry, sweet, and clean; take three pints of solid yest for each puncheon, to which you should add three quarts of the wort at 65, mix and blend the wort and yest together, putting this proportion to each cask, containing four barrels, then fill up with the wort, at the heat of 55, already mentioned; put in your tin workers, one into each puncheon, and when you perceive it begins to work freely, which probably will not be till the third or fourth day, begin to fill up your casks, and so continue doing from time to time, till they have done working. (The tin worker is described in page 139.) This mode of brewing appears to be peculiarly adapted for shipping to warm climates; the fermentation being slowly and coolly conducted: it is also well calculated for bottling. Table beer may be made, after this strong, of good quality, with cold water, if not over drawn; 10 pound of the steeped hops will be sufficient to preserve this beer; one hour's boiling will be enough; ferment as already directed, and add six pounds of sugar just before striking off, rousing, as already directed, while any remains in the copper. _Porter._ In England, is a liquor of modern date, which has nearly superseded the use of brown stout, and very much encroached on the consumption of other malt liquors, till it has become the staple commodity of the English brewery, and of such consequence to the government, in point of revenue, that it may be fairly said to produce more than all the rest. Porter, when well brewed, and of a proper age, is considered a wholesome and pleasant liquor, particularly when drank out of the bottle; a free use is made of it in the East and West Indies, where physicians frequently recommend the use of it in preference to Madeira wine: the following three processes are given under the denomination of No. I., II., and III., the first and second of which I knew to be the practice of two eminent houses in the trade. The third I cannot so fully answer for. An essential object to attend to, in order to ensure complete success to the porter process, is the preparation of the malt. Directions for that purpose will be found at the end of these processes. _Porter Process._ No. I. MATERIALS. 186 Bushels of Pale Malt. 94 Bushels of Brown Malt. --- 280 Bushels of Malt. --- 300 lb. of Hops. 10 lb. of Gentian Root, sliced. 10 lb. of Calamus. 10 lb. of the essence of Gentian. Cleansed 121 barrels. The hops, with the other ingredients, to be put in with the first boil, and retained in the copper by wire strainers, or otherwise, for the succeeding worts. First mashing liquor 165, mash one hour, stand one hour, run down smartly; second mash 170, mash one hour, stand one hour, run down as before; third mash 180, mash half an hour, stand half an hour, run down smartly; divide these three runs into two boilings, boil your first copper as hard as you can for half an hour, the second for three hours as hard as possible; pitch your first wort at 65 degrees, with 10 gallons of smooth yest; pitch your second at 70 degrees, with six gallons, both runs to mix in the same tun, as soon as the head of your tun begins to fall and close, which will possibly happen from thirty to forty hours, at which time it is expected the fermenting heat will rise to 80, but in no case should it be suffered to exceed it; two pecks of bean meal flour, with two pounds of bay salt mixed together, should be evenly scattered over the surface of the tun, before cleansing, and then well roused. After cleansing, this drink should be filled every two hours, for the first twelve fillings, after which, twice a day will be sufficient; and, in about a week after cleansing, porter so brewed, and treated as here directed, will be glass fine, and in a week more may be vatted. As porter is generally sent out in iron-bound hogsheads of seventy gallons each, there should, at the time of going out, be three half pints of finings, with as much heading mixed through the finings at will go on a two shilling piece; this fining and heading should be well stirred in the hogshead by means of a fining brush used for the purpose, with a long iron handle; treated thus, porter will fall fine in a few days. The faster draught porter is drawn off the cask the better it will drink; for when too long, it is apt to get flat, and sour. _Porter Process._ No. II. 160 Bushels of Pale Malt. 120 Bushels of Brown Malt. --- 280 --- 350 lb. of Hops. Cleansed 121 Barrels of Porter. Heat of the first mashing liquor one hundred and seventy-two, mash one hour, stand one hour, run down smartly; second mashing liquor one hundred and eighty, mash one hour, stand two hours, run down as before; third mash one hundred and sixty-four, mash half an hour, stand half an hour, run down smartly; boil the extract of the first, with half the extract of the second mash; boil as hard as you can for one hour and a quarter, then strike off, retaining your hops in the copper for your second boil, which includes half your second wort, and the whole of your third; these should be boiled for four hours as hard as you can make them; pitch your first wort at seventy, or so high that, when in the tun, it will make up at sixty-four, to which give six gallons of smooth yest; pitch your second wort at sixty-five, giving seven gallons more of yest; when all your worts are in your tun, it should make up at sixty-four. Thus managed, it will be fit to cleanse in thirty-six or forty hours; the closing and falling in of the head will direct the period of performing this operation; fill, &c., as in the foregoing process. _Porter Process._ No. III. 88 Bushels of Pale Malt. 102 lb. of Hops. 12 Gallons of Essentia Bina, or sugar colouring. Cleansed twenty-seven and a half Barrels of Porter. First mashing liquor one hundred and sixty, mash one hour, stand one hour; second mashing liquor one hundred and seventy, mash one hour, stand one hour and three quarters; third mashing liquor one hundred and seventy-five, mash half an hour, stand one hour; divide these three runs into two equal parts, boil the first one hour, the second two hours and a half, as hard as you can in both instances; pitch your first wort at sixty, giving two gallons of solid yest; your second at sixty-five, giving the same complement of yest; let your fermenting heat rise to eighty, then cleanse, first topping your tun with two pounds of bean meal flour, and half a pound of bay salt pounded and mixed with the flour; fill fine, and head your porter casks, as already directed to do with hogsheads; let your finings and heading be in that proportion with lesser casks. _Porter Malt._ This species of malt should be made from strong, well-bodied barley, the process exactly the same as for pale malt, until it is about half dried on the kiln; you then change your fuel under the kiln from coak or coal to ash or beech wood, which should be split into small handy billets, and a fierce, strong fire kept up, so as to complete the drying and colouring in three hours, during which time it should be frequently turned; when the colour is found sufficiently high, it may be thrown off; the workmen should be provided with wooden shoes, to protect their feet from the uncommon heat of the kiln in this last part of the process, which requires the grain to snap again from the excessive heat of the kiln. For the better performing this part of the process, I would recommend a wire kiln to be placed adjoining the tiled one, from which it may be cast on the wire; this would be a better and more certain mode of conveying the porter flavour to the malt, than if the drying was finished on the tiled kiln. Where a wire kiln was thought too dear, a tiled one might be made to answer. _Porter Colouring._ In modern language, is termed _essentia bina_. This is made from brown sugar, and is now generally substituted by the London brewers for porter malt, as more economical, and full as well calculated to answer all the purposes of flavour and colouring. Muscovado, or raw sugar, with lime water, are the usual ingredients of this colouring matter. Another kind, of inferior quality, is prepared from molasses, boiled until it is considerably darker, bitter, and of a thicker consistence; and when judiciously made, at the close of the boiling, it is set on fire and suffered to burn five or six minutes, then it is extinguished, and cautiously diluted with water to the original consistence of treacle. The burning or setting on fire gives it the greater part of its flavour, which is an agreeable bitterness, and burns out the unassimilating oil. Muscovado, or raw sugar, when treated in a similar manner, and diluted to the same consistence before it sets, obtains a bitterness that more nearly strikes the porter flavour on the palate; it is of a deep dark colour, between black and red. To prepare it to advantage, take three pounds, or three hundred weight of Muscovado sugar, for every two pounds, or two hundred pounds, of essentia bina intended to be made, put it into an iron boiler set in brick work, so that the flue for conveying the smoke of the fire into the chimney, rises but about two thirds of the height of the boiler in its passage to the chimney. The boiler should have a socket or pivot in the centre of its bottom to receive the spindle of wrought iron, with a crank in it, above the brim of the boiler, the upper end of which turns on a corresponding pivot in an iron bar fixed across several feet above the boiler, with a transverse iron arm to reach from the crank for some feet over the boiler for a man to stand, and turn it with its scraper of iron also, which works on the bottom of the boiler to keep the sugar from burning on the bottom before the upper part melts; this arm may be placed in a wooden handle at the end, and held by the man, lest it become too hot for his hand. Put one gallon of pure water into the boiler with every hundred weight of sugar to be employed, that is, one pint to every fourteen pounds weight of sugar, then add the sugar, light the fire, and keep it stirring until it boils, regulating the fire so as not to suffer it to boil over; as it begins to lessen in quantity, dip the end of the poker into it, to see if it candies as it cools, and grows proportionably bitter to its consistence; mark the height of the sugar in the boiler when it is all melted, to assist in judging of its decrease; when the specimen taken out candies, or sets hard pretty quickly, put out the fire under the boiler, and set the vapour or smoke arising from the boiler on fire, which will communicate to the boiling sugar, and let it burn for ten or twelve minutes, then extinguish it with a cover ready provided for the purpose, and faced with sheet iron, to be let down on the mouth of the boiler with a chain or rope, so as exactly to close the boiler. As soon as it is extinguished, cautiously add _strong lime water_ by a little at a time, working the iron stirrer well all the time the water is adding, so as to mix and dilute it all alike to the consistence of treacle; before it sets in the boiler, which it would do, as the heat declined, in a manner that would give a great deal of trouble to dilute it after, and be imperfectly done then, it is easy to conceive this kind of work requires to be done in an open place, or out-house, to prevent accidents from fire. If the _essentia bina_ is neither burned too little nor too much, it is a rich, high-flavoured, grateful bitter, that preserves and gives an inimitable flavour and good face to porter; to be added in proportion as the nature and composition of the grist is varied with a greater or less proportion of pale malt. _To convert old hock into brown stout_, it will take three pounds of _essentia bina_ of middling or ordinary kind, and but two pounds of the best made from Muscovado raw sugar as directed, it should weigh ten pounds to the gallon. The _essentia bina_ should be mixed with some finings, and roused into the tun soon after the yesty head gathers pretty strong, in order to undergo the decomposing power of fermentation, part of it being prone to float on the surface of the beer under the form of a flying lee. When employed in the usual way of colour, with this precaution, the colouring and preserving parts unite with the beer, and the gross charry parts precipitate with the lees, and other feculencies in the tun, previous to cleansing, adding a firm and keeping quality to the beer. Lime water for diluting the burnt sugar, in the proportion of _essentia bina_: thirty pounds of lime will make one puncheon, or one hundred and twenty gallons of lime water: put fresh lime from the kiln, previously slaked into coarse powder, into an airtight cask, gradually add the water, stirring up the lime to expose a fresh surface to the solvent powers of the water, which will rarely dissolve more than one ounce troy weight in the gallon, or retain so much when kept ever so closely excluded from the external air. If Roche lime was first grossly pounded, and slaked in the cask, the lime water might be made still stronger; the reason for directing the water to be slowly and cautiously added at the first, is for the more conveniently mixing the lime with the water, which otherwise would not be properly wet. Do not fill the vessel within a few gallons of the bung-hole, that it may be rolled over and over with effect, fifteen or twenty different times before left to settle, in order to have the water fully saturated with the lime; when settled it should be perfectly clear. It is important, as well at necessary to state, that when the lime water is about to be added to the _essentia bina_ in the kettle, it should be hot, otherwise there would be danger of cracking the cast iron, of which the kettle is composed, as well as causing a partial explosion and waste of the sugar when coming in contact with the cold medium of the lime water; this precaution should be carefully attended to. _Strong Beer._ Process for brewing strong beer, alleged to be the practice in Switzerland, by which it is asserted that an excellent and preserving beer will be produced. I would recommend a small experiment to be made at first, in order to establish its character and success on a more extended scale. At a first view, there appears to be one serious objection to this process, and that is, that it requires but a small quantity of oily or fatty matter to destroy the fermentation of any guile of beer. In answer, it may perhaps be truly said, that the precaution of skimming off the fatty matter, as it rises on the surface of this beer while in the copper, as well as the time allowed it there to settle, also, its straining through the hops before getting on the cooler, gives another chance to deposite this matter in the hops, if any should remain in the copper after the skimming off. PROCESS AS FOLLOWS: 60 Bushels of Pale Barley Malt. 20 Bushels of Pale Wheat Malt. --- 80 Bushels. --- 170 lb. of the best Hops, to be rubbed, salted, and steeped in one or more close vessels before mashing, or the evening before brewing, still better. 54 lb. of lean Beef to be put into the copper with the worts, this will average two pounds to the barrel. 7 lb. of Rice, also, to be put in with the Beef. 1 lb. of ground Mustard to be put in with the Hops. Cleansed 27 Barrels. These worts are to be boiled one hour without the hops, in order to afford the greater facility of skimming the fat off the surface. After they have boiled the first half hour, the fire is damped, the boil left to subside, and the copper to be then carefully skimmed. (This points out the necessity of an open copper for this operation.) After which, the fire is started again, and the worts made to boil another half hour, and skimmed a second time in the same way; after which the hops and mustard are added with three gallons of the _essentia bina_, and then boiled for one hour and a half, as hard as the copper will allow without boiling over or wasting; the fire is then drawn, ash-pit and copper doors left open, the copper covered, and suffered to stand two hours, then struck off on the hop back. The temperature of the external air at the time you brew this quality of beer should not be higher than fifty degrees. Your first, or mashing liquor, should boil, then run your whole complement into your mash tun, which when cooled down to one hundred and sixty-five, begin putting in your malt, one sack at a time, and mash for one hour and a quarter, stand one hour, run down as fine as you can, yet smartly; second mash one hundred and eighty-five, need not boil, but when brought to that heat in your copper, begin mashing, and mash well for three quarters of an hour, stand two hours; boil, skim, and hop, as already directed. It is to be understood that the produce of these two mashes are to be boiled together, forming a clear length, when cleansed, of twenty-seven barrels; pitch your worts at sixty, previously mixing in a tub, fifteen gallons of your wort at seventy, with one gallon of solid yest, some time before pitching, which will give it time to catch before adding to the remainder of the wort. Twelve hours after another gallon of pure yest is to be added, and the tun well roused, then covered; the attenuation suffered to proceed to eighty degrees, _but not higher_. This mode of pitching worts might be successfully applied to other qualities of beer and ale, and will be found a safe and good process. _Filtering Operation._ (With a Plate.) [Illustration A The fountain. B B The cocks. C The trunk communicating with the space between the two bottoms. D The filtering tub. E The false bottom. F The spout for carrying off the ascending liquor. G The receiver of the filtered liquor by ascent. H The receiver of the filtered liquor by descent.] This simple operation, if my view of its effects on malt liquors, as well as other fermented liquors, be correct, will do more towards their improvement and preservation, than any thing hitherto attempted to be tried on them, after their fermentation has been completed; and for this plain reason, that it will at once disengage them from all fermentable matter, and render them transparently fine and preserving; thus immediately fitting them for the bottle, or putting up into tight casks, for home consumption or exportation, which will soon recover the beer or ale so treated from the flatness that will necessarily be induced by a long exposure to the air during the continuance of the operation; further to remedy which, I would recommend putting into each barrel, before the cask is filled with this beer, half a pound of ground rice, then fill, bung down tight, and in a short time briskness and activity will be restored to the liquor, whether intended for draft or bottle. This mode might, with equal success, be applied to every kind of fermented liquor, particularly to cider, wine, and perry, also to river and rain water. There are two modes of filtration, one by descent, the other by ascent; the latter operation seems to be the most perfect, though not the most economical or expeditious. The preparation of the filtering medium is as follows. Your filtering vessel should be in proportion to the scale of work you intend operating on. The vessel containing the filter, should have the form somewhat of an inverted cone, in proportion wider at top than at bottom; over the bottom of this vessel should be placed a false one, about three or four inches distant from the other; this upper bottom should be perforated with holes, rather large bored, at the angles of every square inch of its surface; your fake bottom being laid, provide two pieces of clean thick blanketing the full size of the vessel, lay these pieces one over the other, over them a stratum six inches deep, of rather coarsely pounded charcoal; this should be previously wetted with some of the beer or ale, till brought to the consistence of coarse mortar; over this lay another stratum of fine clean pit sand, and so on, stratum super stratum, of sand and charcoal, till you have reached within six inches of the top; the cover of this vessel, which is also perforated with holes somewhat smaller than those of the bottom, is let down in the vessel to within one inch of the filtering medium, and in that position is well secured by buttons, or otherwise. When you filter by descent, you run your liquor over this cover, which, by means of the holes, will be distributed evenly over the upper surface of the filter; and so you continue running on your liquor as fast as you see the operation will take it. When you wish to filter by ascent, you introduce the liquor to be filtered between the two bottoms. As the fountain which supplies this liquor is higher than the filtering vessel, it will naturally force its way through the false bottom, filtering medium, &c., until it runs off pure at spout F into the receiver G. Those persons who live on the banks, or in the vicinity of our great rivers, such as the Missouri, Ohio, Mississippi, &c., may purify their drinking water in this way, with great advantage to their health, and consequent increase of comfort to themselves and families. It is also well adapted to the use of those who navigate these waters, particularly such as proceed in steam-boats, where convenient room can be always found for such useful and salutary purposes, and to them I strongly recommend its use. It may also be advantageously applied to filtering rain water, which, to some constitutions, may be more congenial than either spring or river water. _Returned Beer, to make the most of, and double its value._ Suppose, for example, you have one hundred and fifty barrels of this beer, (or in that proportion, adjust your mixing ingredients accordingly,) put the whole into one vat that it will fill; then take half a barrel of colouring, twenty-eight pounds cream of tartar, twenty-eight pounds of ground alum, one pound of salt of steel, otherwise called green copperas, with two barrels of strong finings; mix these ingredients well together, put them into your vat, and rouse well; after which, let the vat remain open for three days; then shut down the scuttle close, and sand it over; in one fortnight it will be fit for use; your own good sense will then direct its application. _To bring several sorts of Beer which have been mixed to one uniform taste._ EXAMPLE. Suppose you have one hundred barrels of this description in your vat; take six pounds of porter extract, six pounds of orange peel, ground, one pound of heading, composed of half a pound of alum, with half a pound of green copperas mixed, six pounds of Indian bark; mix these ingredients with one butt of finings, rouse your vat well, let it remain open three days, then close down your vat, and sand it over; it will be fit in one fortnight to use. _Finings, the best method of preparing them._ A very important object indeed, is finings in the management of porter and brown beers, and sometimes the paler kinds need their agency before they will become transparently fine: without this quality no beer can be acceptable to the consumer, and should be always a particular aim of the brewers to obtain. Take five pounds of isinglass, beat each piece in succession on a stone or iron weight, until you find you can conveniently shred it into small pieces, and so treat every piece until you have got through the whole; thus shredded, steep it in sour porter or strong beer that is very fine, then set the beer and the isinglass on the fire, and there let it remain till you raise the heat to one hundred and ninety, but no higher, keeping it, while on the fire, constantly stirring; then have your hogshead of clear beer ready, strain your dissolved isinglass through a hair sieve into it, which you must take care to mix well; thus assimilated it will be fit for use in twelve hours. It is worth remarking, that at the time of sending out porter or brown beer to your customers is the time to put in both your fining and heading, the jolting it then gets in the carriage will assist its fining more effectually, after it has rested a few days in the customer's cellar. _Heading._ Is variously composed, and differently prepared; what is here recommended will be found safe and effectual. Porter, or brown stout, when intended for draught, should never be sent out in the cask without fining and heading; the usual practice is to put your heading into your fining, and so both into the cask just before filling up and bunging down. The proportion for one hogshead of sixty-three gallons is three half pints of fining, with as much heading put into the fining as you can take up upon a cent piece; the heading here recommended is composed of equal parts of sal martus (or green copperas) and alum, both finely powdered and mixed in equal parts, so as to be intimately blended with each other before using. The advantages derivable from heading are merely apparent, giving a close frothy head to the beer in the quart or mug it is drawn in; supporting the vulgar prejudice, that such beer is better and stronger than that where no such appearance manifests itself. _Bottling Beer._ This is a branch of trade, that, under proper management, might be made very productive and profitable, whereas, in the manner it is now generally conducted, proves a losing one, occasioned by the great breakage of bottles, arising from the impure state of the beer at the time of putting into bottle. In consequence of this bad management, I have known a person, extensive in the trade, to lose on an average from two to three dozen bottles, as well as beer, on every hogshead he put up which happened to lie over till summer, or was bottled in that season; this loss was too heavy to expect much profit from a business so conducted; to obviate both these consequences, I would recommend beer, ale, and porter, intended for the bottle, to be carefully filtered through charcoal and sand, as directed in the operation of filtering; being thus purified from all its feculencies and fermentable matter, it will be in the best possible state for taking the bottle, in that mild and gentle way that will not endanger the loss of one or the other. It will further have the good effect of recovering the beer or ale, thus filtered, from the flatness that will necessarily be induced by that operation, giving the liquor all the briskness and activity that can be wished for. If beer, porter, or ale, be intended for exportation to a warmer climate than our own, the operation will be found particularly suited to it. Choose your corks of the best quality, and steep them in pure strong spirit from the evening before you begin your bottling operation; this precaution is essentially necessary to all beer intended to be shipped, or sent off to a warmer climate than our own, such as the East and West Indies, South America, &c. In more temperate climes, the simple precaution of filtering alone will be found to answer every necessary purpose, without steeping the corks in spirits. But suppose you bottle for home consumption, in that case you will naturally wish to have your beer, ale, and porter, get up in the bottle in as short a space of time as possible, in that case you should pack away your bottles in dry straw in summer, in sawdust in winter, as your object at that season will naturally be rather to accelerate than retard fermentation; here you should carefully watch its progress from day to day, by drawing a bottle from the centre of the heap, as nearly as you can get at it; place this bottle between you and the light, and if you perceive a chain of small bubbles in the neck of the bottle, immediately under the cork, you may conclude your beer is up in the bottle, then draw a few more bottles, and if the same appearance continues in them also, it is time to draw all your bottles from the heap they were originally packed in, and set them on their bottoms in a square frame ten inches deep, size optional; fill up this frame with the bottles of porter, or ale, so drawn in a ripe state, then get one or more bushels of bay salt, and scatter it as evenly as you can over the bottles, until the space between their necks is nearly half filled; then another course of bottles may be sunk between these, with their necks down through the salt, so as to form an upper tier; thus treated, not a single bottle will be found to break from the force of fermentation, and the salt will answer for a fresh supply of bottles, as often as you may find it necessary to draw, or send them out, this quantity will answer your purpose for years, if you only keep it dry; another advantage, and no small one, derivable from a bottling operation conducted in this way, will be, that a loft will be found more convenient for the purpose than a ground floor, as less damp, and more likely to preserve the salt dry, which a more moist atmosphere would naturally dissolve. The practice here recommended may, with equal success, be applied to cider and perry. _Brewing Coppers, the best method of setting them._ This article, at a first view, may not appear to have much connexion with brewing, but, when attentively considered, it has a very material one, as also with economy, by saving nearly one half the fuel. It is a well-known fact in brewing, that the quicker and stronger the operation of boiling is performed, the better such beer will preserve, and the sooner it will become fine; although this opinion is combated by many, experience has proved it in my practice. I will suppose the copper you are about to set to contain two thousand gallons, the diameter of its bottom, five feet; let your fire blocks, if possible, be of soapstone, one for each side, and one for the end, of sufficient thickness and length, and full twelve inches deep, to the top of your sleepers; three courses of brick, sloped off from the top of the fire stone, with the usual quantity of mortar, and plastered over, will afford sufficient elevation for the fire to act on the bottom of the copper, leaving a space of about eighteen or twenty inches from the bottom to the top of the sleepers; the breadth of the fireplace need not exceed twenty-six inches. When the copper is about to be placed on the blocks, by swinging, or otherwise, three feet of the bottom of the copper should be on one side from the centre of the furnace, and but two feet on the other; I would have but one flue or entrance for the fire to round this copper, which flue should be placed on the three feet side, twenty-four inches long at the mouth; distance of the brick work from the copper, six inches, to narrow to five at the closing; the first closing to be three feet high on the side of the copper; the second closing, to be two feet above that, leaving twenty-one inches clear flue, allowing three inches for the thickness of the brick and mortar; the throat of the first flue, leading into the second; twenty-four inches distance of upper flue from the copper, five inches closing into four and a half inches at top. A short distance above the top of your copper should be placed an iron register to regulate the fire, so contrived as to be handily worked backward and forward by the brewer, or the man tending the fire, as circumstances may direct. The furnace door should be in two parts, one to hang on each side of the frame, and so lap over a small round hole, with a sliding shut to it, should be fixed in one of these doors, to admit the iron slicer to stir the fire. The clear of the furnace frame need not exceed sixteen inches high, by eighteen inches wide. A copper so set and proportioned, by being kept close covered at top, might be expected to boil cold water in one hour and fifteen minutes, perhaps in one hour, and that with a great saving of fuel compared with the same sized copper set in the ordinary way. _Pumps, the best and most economical construction, also the most effectual, and least liable to fail or get out of order; how best treated in cold weather to prevent freezing, or when frozen to remove the inconvenience._ Freezing often retards the brewer's operations, and gives him considerable trouble and delay. To obviate these inconveniences, I would recommend having the rod of wood, instead of iron, so long as to work in a brass chamber, two feet above the lower box; if the pump be long, the rod may be made with joints of iron, and keys properly made, so as to have it in two, three, or four pieces, capable of being taken asunder; suppose the diameter of your chamber to be six inches, I would have the diameter of the rod five inches, which, being so much lighter than the column of water it displaces, will make the stroke comparatively light and easy to the horse, and not near so great a strain on the pump, delivering as much water or wort, it is expected, as will be found necessary for all the purposes of a brewery. But should it so happen, that any deficiency is found in the quantity of water and wort so delivered, it is only necessary to reduce the diameter of the wooden rod, from one quarter to half an inch more, and this will proportionably augment the quantity of water and wort delivered at each stroke. The water pumps, which in winter are exposed to the effects of the external air, should have a casing round them of boards from the level of the ground to half their height above it, which casing should be stuffed with dry hay, straw, or shavings, and well rammed; this casing should be water-tight round the pump, at the top, and a cock placed over it on one side of the pump, to let off the standing water; then stuff the mouth of the pump with hay or straw, and so treated the remaining water in the pump will never freeze in the coldest winter. But where these precautions have not been taken, and the charge in your pump becomes frozen, and you wish to clear it, get one quart of bay salt, throw it into your pump, stop the mouth of it at the top, and in the course of a few hours the salt will have dissolved the ice in your pump, and you may go to work; this is much more effectual and less troublesome than using hot water, which must be repeated in great quantities before it will produce its effect. _Cleansing Casks._ Trifling and simple as this operation may appear, it is still one that is highly important to the brewer, and requires minute and constant attention. Burning and steaming casks seems to be two most effectual modes of accomplishing this important object. If your casks have been long in use, and thereby contracted any musty or bad smell, the best way is to open them; wash them well out with boiling water; set them to dry, and then fire them, after which, they may be washed out again with hot water, and, when dry, headed for use; every cask after emptying, that is not perfectly sweet, should be treated in this way, particularly when intended for stock or keeping beer. New casks that have never been used, are best prepared by steaming them, and a small boiler, containing from sixty to one hundred gallons will be best suited to this purpose. If you have tin pipes communicating from one cask to another, you can steam four or five at a time, and the work goes on expeditiously. Fresh emptied small beer, and single-ale casks, can be sufficiently cleansed by chaining them; after which, rincing them out with hot water will be found a sufficient cleansing for such casks, as they are generally but a short time on draught. The operation of chaining casks is performed by putting into them, with boiling water, a small iron chain, two or three yards long, and then tossing your cask several times round and round so as to get the chain to rub, and act upon every part of the inside head, &c., this will take off the yest, &c. The smoother and evener all brewers' casks are made on their inside the better, as they are thereby the more easily cleaned. Every brewer should be particular in recommending to his customers carefully to cork up every cask as drawn off--by this simple precaution they will be preserved sweet for months, while the neglect of it will cause them to get foul in a short time, to the great increase of trouble and expense to the brewer before he can sufficiently purify them. It is also a necessary precaution to keep casks, when brought home, from the action of the sun and weather, by placing them under proper sheds; where casks are supposed to occupy one fifth of the brewer's active capital, they should at all times be carefully looked after. _The following processes are given principally for the use of gentlemen farmers, housekeepers, and others, who may occasionally wish, as well as find their account, in brewing their Mead or Metheglin._ THE PROCESS. For every pipe of mead allow one hundred and sixty-eight pounds of honey. On a small scale, take ten gallons of water, two gallons of honey, with a handful of raced ginger, and two lemons, cut them in slices, and put them, with the honey and ginger, into the water, boil for half an hour, carefully skimming all the time; use a strong ferment, and attenuate high, not under seventy-eight; in the boiling add two ounces of hops to the above ten gallons of water and two gallons of honey. In about three weeks, or one month, after cleansing and working off, this mead will be fit to bottle. This liquor, when thus made, is wholesome and pleasant, and little, if any, inferior to the best white wines. It is particularly grateful in summer, when drank mixed with water. _Ginger Wine._ Take sixteen quarts of water, boil it, add one pound of bruised ginger, infuse it in the water for forty-eight hours, placed in a cask in some warm situation; after which time strain off this liquor, add to it eight pounds of lump sugar, seven quarts of brandy, the juice of twelve lemons, and the rinds of as many Seville oranges; cut them, steep the fruit, and the rinds of the oranges, for twelve hours in the brandy, strain your brandy, add it to your other ingredients, bung up your cask, and in three or four weeks it will be fine; if it should not, a little dissolved isinglass will soon make it so. _Currant Wine._ Take five gallons of currant juice, and put it into a ten gallon cask, with twenty pounds of Havanna, or lump sugar, fill the cask with water, let it ferment, with the bung out, for some days; as it wastes fill up with water; when done working, bung down; and in two or three months after it will be fit for use: two quarts of French brandy added, after the fermentation ceases, would improve the liquor, and communicate to it a preserving quality. Wine may be made from strawberries, raspberries, and cherries in the same way. _Yest, how prepared, so as to preserve sweet and good in any climate._ This operation, I apprehend, however simple it may appear, will have very important consequences, whether we consider it as a medicine (and in putrid fevers there is, perhaps, no better known) or a ferment. It will be well worth the attention of the physician, the brewer, the distiller, the merchant, and the housekeeper, whether resident in the temperate, or in the torrid zone. Mr. Felton Mathew, merchant in London, obtained a patent for the above-mentioned object, which may be found in the Repertory of Arts, vol. V. page 73. Mr. Mathew used a press with a lever, the bottom made with stout deal or oak timber, fit for the purpose, raised with strong feet a convenient distance from the ground, so as to admit the beer to run off into whatever is prepared to receive it; into the back of it is let a strong piece of timber, or any other fit material, to secure one end of the lever, the top of which should work on an iron bolt or pin; when the lever is thus prepared, get your yest into hair-cloth bags, or, if not conveniently had, into coarse canvas bags; when filled, tie them securely at the mouth, and place one bag at a time in a trough of a proper size with a false bottom full of holes, on this bottom should be placed an oblong perforated shape, about the form of a brick mould; in this oblong shape or box, without either bottom or top, is placed the bag containing the yest, on which the press is let down, and gradually forced, as the beer exudes, or gradually runs off; when no more liquid runs from the shape, the press is taken off, and the bag opened, its contents taken out, which will crumble to pieces; in this state it should be thinly spread on canvass, previously stretched in frames, which will permit the heated air of the kiln to pass through it in all directions, and thus gradually finish the process to perfect dryness, which will be completely effected by ninety degrees of heat: at the commencement of the drying, it would be proper to pass the edge of a board over each frame, in order to reduce the lumps of yest, and thereby make them as small as possible. When completely dry, put it into tight casks or bottles so as to exclude air and moisture: thus secured, it will preserve good as long as wanted in any climate, and be found a valuable article of domestic economy, as well as medicine. When to be used, the necessary quantity should be dissolved in a little warm water, at the temperature of from eighty to ninety degrees of heat, with the addition of a proportionate quantity of sugar; the addition of sugar is only recommended when used to raise bread, but not when given as medicine; in the opinions of several intelligent men, this is considered the simplest and most effectual method of preserving yest, and, as such, is hereby strongly recommended. _To make a substitute for Brewer's Yest._ Take six pounds of ground malt, and three gallons of boiling water, mash them together well, cover the mixture, and let it stand three hours, then draw off the liquor, and put two pounds of brown sugar to each gallon, stirring it well till the sugar is dissolved, then put it in a cask just large enough to contain it, covering the bung hole with brown paper; keep this cask in a temperature of ninety-eight degrees. Prepare the same quantity of malt and boiling water as before, but without sugar, then mix all together, and add one quart of yest; let your cask stand open for forty-eight hours, and it will be fit for use. The quart of yest should not be added to these two extracts at a higher heat than eighty degrees. _Another method to make twenty-six gallons of the substitute._ Put twenty-six ounces of hops to as many gallons of water, boil it for two hours, or until you reduce the liquor to sixteen gallons; add malt and sugar in the proportion before mentioned, and mash your malt at the heat of one hundred and ninety degrees; let it stand two hours and a half, then strain it off, and add to the malt ten gallons more of water at the same degree of heat, and mash a second time; let it stand two hours, then strain it off as before; when your first mash is blood heat, or ninety-eight, put to it one gallon of the preceding substitute, mix it well, and let it stand ten hours; then take the produce of the second mash, and add it, at ninety-eight, to the rest, mix it well, and let it stand six hours, it will be then fit for use in the same manner, and for the same purposes as brewer's yest is applied; the advantages alleged in favour of this method are, that it will keep sweet and good longer than brewer's yest, and in any reason or temperature be fit for use. _Brewer's Yest._ May be generated in the following way: Take one pound of leaven, made with wheaten flour, such as the French generally use to raise their bread, dilute the pound of leaven with water or wort, the latter to choose at ninety degrees of heat, add it to your wort at the heat of sixty-five, supposing your barrel to be filled with wort at this heat; then add your leaven, diluted as mentioned, until your cask be full; to effect which, with less waste and more certainty, it may be better to put into your barrel the diluted leaven first, then fill up with wort at the temperature mentioned; after a day or two the beer will begin to work out yest, and will serve as a ferment for another brewing; thus, after three or four brewings, your yest will become so improved that it will be nearly equal to any brewer's yest, and the experiment in certain situations is well worth trying, when a proper ferment is wanted and cannot be otherwise procured. _Process for making and preparing Claret Wine for shipping; without which preparation such wines are considered unfit for exportation, being in its natural state about the strength of our common Cider._ Claret wine, before the French revolution, was the staple article of export from the great commercial City of Bordeaux, to every part of Europe. And, it may be presumed, will soon again reassume its wanted importance. The vintage generally begins, for making this sort of wine, about the middle or latter end of September, and is generally finished in all the month of October. The mode by which the juice is expressed from the grape, is by the workmen trampling them with their bare feet in a large reservoir or cooler, (not the cleanest operation in the world,) which has an inclination to the point where the spout or spouts are placed for taking off the expressed juice, which is conveyed to large open vats, that are thus filled with this juice to within ten or twelve inches of the upper edge; this space is left to make room for the fermentation, which spontaneously takes place in this liquor. After the first fermentation is over, and the wine begins to purify itself, which is ascertained by means of a small cock placed in the side of the vat, and takes place generally by the middle of February, or beginning of March, in the following year; it is then racked off into hogsheads, carefully cleansed, and a match of sulphur burned in each cask before filling; when thus racked off, it is bunged up, and immediately bought up by brokers for the Bordeaux merchants, and here it is made to undergo the second or finishing fermentation, in the following manner: It may be proper here to remark, that claret wine is generally divided into three growths, first, second, and third; the first growths, namely, Latour, Lafeet, and Chateaux Margo, are uniformly rented for a term of years, at a given price, to English merchants, through whom, or their agents _only_ is there a possibility of procuring any portion of this wine. The second growths are shipped to the different markets of Europe, North and South America; and the third growth principally to Holland and Hamburgh. In order to strengthen the natural body of claret wine, and to render it capable of bearing the transition of the sea, the first and second growths are allowed from ten to fifteen gallons of good Alicant wine to every hogshead, with one quart of stum.[8] The casks are then filled up and bunged down. They are then ranged three tier high from one end of the cellar to the other, each tier about eighteen inches, with two stanchions of stout pine plank, firmly placed between the heads of each hogshead, from one end of the cellar to the other, until they have reached, and are supported by, the end walls of the building. This precaution is necessary to guard against the force of fermentation, which is often so strong as to burst out the heads of the hogsheads, notwithstanding the precautions taken to secure them in the situation during the summer heats. The wine cooper, who has the charge of these wines, regularly visits them twice a day, morning and evening, in order to see the condition of the casks, and when he finds the fermentation too strong, he gives vent, and thus prevents the bursting of the casks. The third, or inferior growth, is exactly treated in same way, with the single exception of having Benicarlo wine substituted for Alicant in preparing them for their second fermentation, as cheaper and better suited to their quality; both these wines are of Spanish growth, and brought to Bordeaux by the canal of Languedoc: they are naturally of a much stronger body than native claret. Thus mixed and fermented, the claret becomes fortified, and rendered capable of bearing the transition of seas and climates. About the latter end of September, or beginning of October, the fermentation of these wines begins to slacken, and they gradually become fine; in this state they are racked off into fresh hogsheads carefully cleansed, and a match of sulphur burned in each before filling. After this operation, they are suffered to remain undisturbed (save that they are occasionally ullaged,) till about to be shipped, when they are racked off a second time, and fined down with the white of ten eggs to each hogshead; these whites are well beat up together with a small handful of white salt; after this fining, when rested, the hogsheads are filled up again with pure wine, and then carefully bunged down with wooden bungs, surrounded with clean linen to prevent leaking; in this state the wines are immediately shipped. Here it may be proper to state, that the lees that remain on the different hogsheads that have been racked off, are collected and put into pipes of one hundred and forty, or one hundred and fifty gallons each, and this lee wine, as it is termed, is fined down again with a proportionate number of eggs and salt. After which, it is generally shipped off as third growth, or used at table mixed with water. If at any time hereafter the method herein given of making and preparing claret wine for shipping, as practised in Bordeaux and its neighbourhood, should be applied to the red wines of this country, particularly those of Kaskaskias; it may be proper here to give a description of the mode in which these wines are racked, which will be found simple, effectual, and expeditious; I mean for the lower or ground tiers. The upper, or more elevated ones, rack themselves, without coercion of any kind. When you are about to rack a hogshead of wine upon the ground tier, you place your empty hogshead close to the full one, in which you then put your brass racking cock; on the nozzle of which cock you tie on a leather hose, which is generally from three to four feet long; on the other end of this hose is a brass pipe, the size of the tap hole, with a projecting shoulder towards the hose to facilitate knocking in this pipe into the empty hogshead, which is then removed a sufficient distance from the full hogshead in order to stretch the hose, now communicating with both. The cock is then turned, and the wine soon finds its level in the empty hogshead; then a large sized bellows, with an angular nozzle, and sharp iron feet towards the handle, which feet are forced down into the hoops of the cask on which it rests, in order to keep this bellows stationary, whilst the nozzle is hammered in tight at the bung hole of the racking hogshead; the bellows is then worked by one man, and in about five minutes the racking of the hogshead is completed. The pressure of the air introduced into the hogshead, by the bellows, acts so forcibly on the surface of the liquor, that it requires but a few minutes to finish the operation; when the cock is stopped, the hose taken off, and a new operation commences. This mode may possibly, in some cases, be advantageously applied to racking off beer, ale, and cider. [8] Stum is a certain quantity of white wine, strongly impregnated with sulphur. The mode of preparing it is as follows: A hogshead half filled with good white wine, or what is termed in French _vin de grave_; from fifteen to twenty long matches of sulphur are successively burned to this hogshead, with the bunghole closed. After this operation, the white wine becomes so impregnated with sulphur, that it has acquired all its taste and flavour, and is thus used as a ferment. _Brewing Company._ It is obvious to very slight observation, that the day is not distant when the brewing trade in this country will, as in England, become an object of great national importance, highly deserving the protection and encouragement of our general government, by freeing its produce from all duty, and thereby affording further inducements to the speculating and enterprising capitalists of this country to embark their funds in a trade that, above all others, is the best calculated to make them a sure and profitable return. In addition to the pleasing consideration that they are thereby combating and putting down the greatest immorality our country is chargeable with, namely, the too great use of ardent spirits, substituting in their place a wholesome and invigorating beverage. The person, therefore, whoever he may be, who contributes his money, or his talents, to this useful and moral purpose, deserves to rank high among the best friends of his country. Under these impressions it is that I beg leave to recommend to my fellow citizens the immediate establishment of a brewing company, with a capital of from thirty to forty thousand dollars, to be subscribed for in shares the most likely to be made up. With either of these sums a handsome beginning could be made, and the profits would in a few years encourage and justify enlargement to any prudent extent that could be reasonably wished for or required. In proof of the correctness of this opinion, I will beg leave to state a fact that has happened in my own time. When the mercantile house of Beamish & Crawford, of Cork, erected a porter brewery in that city, about twenty-five years ago, that establishment was the first of the kind in that town, and then stood alone, and notwithstanding that many large and rich ones in the same business have since been added, the original company have so progressed in fame and fortune, as to be now considered one of the first-rate breweries in Europe; and by the improved quality of their porter have, in a great degree, excluded the English from the West India market, their porter getting the preference there, as well as in Bristol and Liverpool, to which places large quantities are annually sent by that company. How much stronger inducements have we to form similar establishments in this country, where our excise on brewery produce bears no sort of proportion with that paid in England, and does not here exceed five per cent. on brewery sales. This being a war tax, it may be presumed it will not continue long. Our capacity to raise barley and hops, in as high perfection as in any part of Europe, is acknowledged; all then that is wanting is encouragement; afford this to our farmers, and they will soon convince you that no assertion is better founded. If so, the sooner a company of this description is formed the better for those who may be concerned; and for this plain reason, that notwithstanding the enormous excise chargeable on the raw materials and produce of the brewery in England, large fortunes have been, and are daily accumulating in that country by the judicious exercise of the brewing trade, as will appear by the following statement of the quantity of porter alone (beside other malt liquors) brewed by the twelve first breweries in London, in one year, ending 5th of July, 1810. _Barrels of Porter._ Barclay, Perkins & Co. 235,053 Read, Mecar & Co. 211,009 Trueman & Hanbury. 144,990 Felix, Calvert & Co. 133,493 Whitebread & Co. 110,939 Amery, Meux & Co. 93,660 Combe & Co. 85,150 Brown & Perry. 84,475 Godwin, Skinner & Co. 74,223 Elliot & Co. 57,851 Taylor. 54,510 Cloyer & Co. 41,590 --------- Total quantity of Barrels of Porter, 1,326,943 * * * * * NOTICE. The author informs those persons who may feel disposed to engage in the brewing and malting trades, that he can furnish them with ground plans, and sections of elevation, both of breweries and malt houses, on different scales, whether intended to be erected together, or separately, as will be found to unite, economy, convenience, and effect, joined to a considerable saving to those who are not themselves judges of such erections, or how they should be disposed. An experience of twenty-five years in both businesses, accompanied by a diligent and attentive practice, justifies these assertions. His terms will be found reasonable, and all letters (post paid) addressed to Joseph Coppinger, 193 Duane-street, New-York, will receive attention. A few copies of this work may be had by applying as above; but any number may be had at 45 John-street. TANNING. The following is the French mode of tanning all kinds of leather in a short time, highly important to the manufacturers of leather in this country, as it points out a secure and profitable mode of turning their capital twelve or thirteen times in a year, instead of once. _Washing Hides._ The best method of washing hides is to stretch them in a frame, and place them, thus stretched, in running water. If running water cannot be conveniently had, still water can be made to answer by frequent stirrings and agitations; the remainder of the operation of cleansing is performed as in the common way. _On taking off the Hair._ Begin by shaking some lime in a pit, to which put a great quantity of water, then stir this water well, that it may become saturated with the lime, then place your hides in the pit perpendicularly; for this purpose, several wooden poles should be fixed across the pit; to these poles the hides are to be fastened with strings at proper distances, each hide being first cut in two; whilst the hides were thus placed in the lime water, the lime itself, which had deposited on the bottom of the pit, was frequently stirred up to increase the strength of the water, and to make it more operative; the hair thus treated, will, in about eight days, come off the hide with great ease. A shorter and a better method may effect this purpose in two days; that is, to plunge the hides, after being washed and cleaned, into a solution of tan, which (having been already used) contains no longer any of the tanning principle, mixed with a five hundredth, or even a thousandth part of the oil of vitriol, commonly called sulphuric acid; this operation not only takes off the hair, but raises and swells the hide; as, in the old way, is generally effected by barley sourings. However, further swelling and raising is necessary, and the hides should again be plunged in another quantity of spent tan-water mixed with the one thousandth part of the oil of vitriol, and thus steeped a second time; their swelling and raising will be completed in about forty-eight hours; after this operation the hides will acquire a yellow colour, even to the interior part of their substance. To determine if the swelling and raising be sufficiently completed, let one of the corners of the hide be cut, and if it is in a proper state there will not appear any white streak in the middle, but the hide throughout its whole substance will have acquired a yellow colour, and semi-transparent appearance. Mr. S---- is of opinion, that swelling and raising hides is not necessary, and that the hides tanned without this operation are less permeable to water. On tanning on the new principle, as practised by Mr. S----, he places several rows of casks on stillings sufficiently elevated above the ground to place a can or tub under them; these casks were filled with fresh finely ground tan, then a certain quantity of water was poured into the first of them, which water, as it ran through the tan, exhausted and carried off the soluble part, and as fast as it ran into the vessels below, was taken away and poured on the second cask, and so on successively until the solution was sufficiently saturated, and thus it may have been brought to ten or twelve degrees of the arometer for salts. In order to exhaust the tan of the first cask, Mr. S---- continued pouring water on the first cask until it ran off clear; at which time the tan was deprived of its soluble part; these liquors, as it may be easily conceived, were carefully kept for future operations; large wooden vats are considered the best sort of vessels for holding this solution, as well as for making and preparing it; hogsheads, on a small scale, may be made to answer. It is particularly in the use of this solution that Mr. S----'s method consists; the quickness with which the solution acts is truly astonishing, and when we see it, there is cause of surprise in thinking why it was not found out before. As soon as the hides are taken out of the water, impregnated with sulphuric acid, Mr. S---- puts them into a weak solution of tan, in which he leaves them for the space of one or two hours; he afterwards plunges them into other solutions of tan, more or less charged with the tanning principle, in proportion to their strength, so that in the experiments at which we were present, some heavy hides were tanned in six or eight days, others in twenty and twenty-five days. In placing the hides in the solutions, some precautions are necessary; the hides should be suspended on a wheel, or in a frame where they should be stretched, and placed one inch apart, so as to admit the solution freely about them; Mr. S---- recommends cutting off the head and the neck of the hide, and a slip down each side, in which slip the feet and belly part are to be comprehended; and the circumstance which determines Mr. S---- to cut the hide in this manner is, that the feet, and the parts that are near the belly, are more spongy and more easily penetrated by the tan; and as they produce leather of an inferior quality they may be more advantageously tanned separately, than put promiscuously into the solutions of tan with the rest. The remaining part of the hide is to be divided into two or more parts or pieces, so as to be easily placed in the vats or casks. _Drying the Hides._ The hides, when taken out of the solution of tan, must be dried with the usual precautions, that is to say, so slowly, that the skin does not shrink on the flesh side. With respect to thinner hides, for the upper leather of shoes, Mr. S---- begins by washing and taking off the flesh in the manner already described, or, as is done in the common way for strong soal leather; he then takes off the hair by means of clear lime-water; he does not make them undergo the operation of swelling, but puts them immediately into weak solutions of tan, the strength of which he gradually increases, but without ever bringing it to the degree of contraction, which he gives it when it is to be used in tanning thick leather; two, three, or four days, are enough for tanning the thinner kind of leather. Leather which is not sufficiently impregnated with the tanning principle, is generally known by a white speck or streak, which is observable in the middle of its substance. We can affirm that those hides which were tanned in our presence, in a few days, were completely tanned, as the above mentioned white streak was not perceivable; we may also add, that Mr. S----'s method has the advantage of affording the opportunity of observing and examining, from time to time, the progress of the operation; for this purpose nothing more is necessary but to take a slip off the hide out of the vat, and cut off a corner of it, the white streak already spoken of will appear more or less thick, until the tanning is completed; it has been generally supposed, that the tan in the tanpits had no other effect upon the leather than that of hardening and bracing the fibres of the skin, which has been relaxed by the preliminary of tanning. Mr. S----, however, examined the operation more closely, and discovered that there existed in the tan a principle which was soluble in water, by which the tanning was brought about. That this principle afterwards became fixed in the leather in consequence of a particular combination between the said principle and the skin; and this combination produced a substance that was not soluble in water; all this has been demonstrated by Mr. S----, in the most evident manner. It is well known that if leather, which has not been tanned, is boiled in water, it is in a short time almost entirely dissolved therein. This solution, by being concentrated, produces a jelly, or size, which, by farther evaporation, and being dried in the air, becomes what is called glue. Mr. S---- having, in the course of his experiments, examined the effects of a solution of tan upon a solution of glue, observed that they were hardly mixed together before a white felamentous precipitate took place, owing to a combination of the glue with the tanning principle contained in the solution of tan. This precipitate is insoluble in water, either hot or cold, and acquires colour by being exposed to the light. The foregoing experiment furnishes a true explanation of the process of tanning; for it will easily be conceived that the solution of tan acts upon the hides (from which glue is produced) in the same manner as it acts upon glue; this is what really happens in common tanpits, and Mr. S----'s new method, in which the solution of tan gradually penetrates the hides, and as it penetrates combines with it, producing a gradual change of colour that is very observable, till at last the colour of the hide is changed throughout, and it acquires a compact texture and marbled appearance, like that of a nutmeg: by this it plainly appears, that a precipitation also takes place in the action of tanning, although the hide is not dissolved, but merely swelled so as to enable the solution to penetrate it more easily. The property which animal jelly, or glue, possesses, of being precipitated by a solution of the tanning principle, furnishes a means of discovering what substances may be useful in tanning: nothing more is necessary than to make a solution or infusion of the vegetable substance supposed proper for that purpose, and that upon being mixed with a solution of glue, will show by the greater or less quantity of precipitate produced, what probability there is that such substance might be advantageously employed in tanning. _Another Remark._ Lime-water also offers an excellent means of discovering such substances. If lime-water be added to a solution of tan, the mixture instantly produces a copious precipitate; and if a sufficient quantity of lime-water be added to neutralize the whole of the tanning principle, then the supernatant liquor, although still possessing colour, will not form any precipitate with glue; I mean in solution. In like manner the liquor separated from a precipitation, caused by the mixture of a solution of tan with one of glue, will not produce any precipitate with lime-water, if, during the precipitation, the tanning principle has been completely neutralized. This shows evidently that Doctor M'Bride's method of exhausting the tan by means of lime-water is defective, and that by so doing a loss of the tanning principle takes place, in proportion to the quantity of it contained or combined with the lime dissolved in the lime-water. _Another Remark._ As in summer the solution of tan is disposed to run into the vinous fermentation, and, of course, from that into the acetous, and have its principal changed, no more of the solution of tan should be prepared in the summer season than is wanted for immediate use. In winter, this precaution in not necessary, as in that season it will keep, and may be then prepared for exportation to any part of Europe and thus converted into a profitable article of commerce. _A table showing the time different hides took to be completed, in the operations of preparing and tanning._ Ten ox hides, taken the 17th of August, were completely tanned by the 6th of September, in all, twenty days. Washing the hides, 2 days. Taking off the hair, 5 do. Raising or swelling, 5 do. Second washing, 2 do. Tanning, (properly so called,) 6 do. --------- 20 days. Ten ox hides, taken the 19th of July, were tanned the 9th of August, making twenty-one days. Washing, 2 days. Taking off the hair, 10 do. Swelling, 1 do. Tanning, 8 do. --------- 21 days. One ox hide, taken the 3d of September, was tanned the 2d of October, making twenty-nine days. Washing, 1 day. Taking off the hair and swelling, 3 do. Tanning, 25 do. --------- 29 days. Another ox hide, taken the 5th of September, was tanned the 3d of October, making twenty-eight days. Washing, 1 day. Taking off the hair and swelling, 2 do. Tanning, 25 do. --------- 28 days. N.B. The tanning solutions made use of to these hides was less strong, and of a cooler temperature than usual, by which the time employed in the tanning operation was prolonged. _Calf Skins._ Sixteen very thick calf skins, taken the 18th of July, were tanned by the 31st of the same month. Washing, 1 day. Taking off the hair, 8 do. Tanning, 4 do. --------- 13 days. --------- Six calf skins, taken the 19th of July, were tanned the 2d of August, making fourteen days. Washing, 2 days. Taking off the hair, 9 do. Tanning, 3 do. --------- 14 days. --------- Six dried calf skins, began the 14th of August, were tanned the 28th of August. Washing, 2 days. Taking off the hair and swelling, 11 do. Tanning, 1 do. --------- 14 days. --------- Six calf skins, began the 20th of August, were finished the 10th of September. Taking off the hair and washing, 20 days. Tanning, (properly so called,) 1 do. --------- 21 days. --------- Three calf skins were brought from another tan-yard, the operation of tanning had been begun upon them, they having been thirteen days in the tanpit, in which it was intended they should have remained eleven months, (which was the usual time allowed such skins in the old way of tanning;) two of these skins were tanned in twenty-four hours, the third was tanned in forty-eight hours. Six other calf skins took thirteen days. Washing and taking off the hair, 6 days. Tanning, 7 do. --------- 13 days. --------- _Three salted Cow Hides_, Began the 14th of August, were finished the 12th of September. Washing and taking off the hair, 20 days. Tanning, 9 do. --------- 29 days. --------- _One fresh Horse Hide_, Began the 30th of August, was finished the 13th of September. Washing, 1 day. Taking off the hair, 6 do. Tanning, 7 do. --------- 14 days. --------- _Another fresh Horse Hide_, Began the 4th of September, was finished the 19th of September. Washing, 1 day. Taking off the hair, 7 do. Tanning, 7 do. --------- 15 days. --------- _Two dried Sheep Skins_, Began the 14th of August, were finished the 12th of September. Washing and taking off the wool, 25 days. Tanning, 4 do. --------- 29 days. --------- _Three Goat Skins_, Began the 16th of August, were finished the 10th of September. Washing and taking off the hair, 23 days. Tanning, 2 do. --------- 25 days. --------- _Five Goat Skins_, Began the 19th of August, were finished the 10th of September. Washing and taking off the hair, 20 days. Tanning, 2 do. --------- 22 days. --------- THE END 
21252	----	THE PRACTICAL DISTILLER: OR AN INTRODUCTION TO MAKING WHISKEY, GIN, BRANDY, SPIRITS, &c. &c. OF BETTER QUALITY, AND IN LARGER QUANTITIES, THAN PRODUCED BY THE PRESENT MODE OF DISTILLING, FROM THE PRODUCE OF THE UNITED STATES: _SUCH AS_ RYE, CORN, BUCK-WHEAT, APPLES, PEACHES, POTATOES, PUMPIONS AND TURNIPS. _WITH DIRECTIONS_ HOW TO CONDUCT AND IMPROVE THE PRACTICAL PART OF DISTILLING IN ALL ITS BRANCHES. _TOGETHER WITH DIRECTIONS_ FOR PURIFYING, CLEARING AND COLOURING WHISKEY, MAKING SPIRITS SIMILAR TO FRENCH BRANDY, &c. FROM THE SPIRITS OF RYE, CORN, APPLES, POTATOES, &c. &c. _AND SUNDRY EXTRACTS OF APPROVED RECEIPTS_ FOR MAKING CIDER, DOMESTIC WINES, AND BEER. BY SAMUEL McHARRY, OF LANCASTER COUNTY, PENN. PUBLISHED AT HARRISBURGH, (PENN.) BY JOHN WYETH. ----1809.---- DISTRICT OF _PENNSYLVANIA_, TO WIT: [Illustration: SEAL.] Be it remembered, that on the twenty fourth day of November, in the thirty-third year of the Independence of the United States of America, A. D. 1808, SAMUEL McHARRY, of the said district, hath deposited in this Office, the title of a Book, the right whereof he claims as author, in the words following, to wit: _The Practical Distiller: or an introduction to making Whiskey, Gin, Brandy, Spirits, &c. &c. of better quality, and in larger quantities, than produced by the present mode of distilling, from the produce of the United States: such as Rye, Corn, Buckwheat, Apples, Peaches, Potatoes, Pumpions and Turnips. With directions how to conduct and improve the practical part of distilling in all its branches. Together with directions for purifying, clearing and colouring Whiskey, making Spirits similar to French Brandy, &c. from the Spirits of Rye, Corn, Apples, Potatoes &c. &c. and sundry extracts of approved receipts for making Cider, domestic Wines, and Beer. By SAMUEL McHARRY, of Lancaster county, Pennsylvania._ In conformity to the act of the Congress of the United States, entitled, "An act for the encouragement of Learning, by securing the copies of Maps, Charts, and Books, to the Authors and proprietors of such copies during the times therein mentioned." And also to the act, entitled, "An act supplementary to an act, entitled, 'An act for the encouragement of Learning, by securing the copies of Maps, Charts, and Books, to the authors and proprietors of such copies during the time therein mentioned,' and extending the benefits thereof to the arts of designing, engraving, and etching historical and other prints." D. CALDWELL, _Clerk of the district of Pennsylvania._ CONTENTS: _Page_ SECTION I _Observations on Yeast._ 25 _Receipt for making stock Yeast._ 27 _Vessel most proper for preserving_ do. 30 _To ascertain the quality of_ do. 31 _To renew_ do. 32 _Observations on the mode in which distillers generally work_ do. 33 _How stock Yeast may be kept good for years._ 34 _To make best Yeast for daily use._ 36 SECTION II _Observations on the best wood for hogsheads._ 39 _To sweeten by scalding_ ditto. 41 Ditto, _burning_ do. 42 SECTION III _To mash rye in the common mode._ 44 _Best method of distilling rye._ 45 _To mash one-third rye with two-thirds corn._ 47 Do. _an equal quantity of rye and corn._ 49 Do. _two-thirds rye and one-third corn._ 51 Do. _corn._ 54 _To make four gallons to the bushel._ 55 _To know when grain is sufficiently scalded._ 58 _Directions for cooling off._ 59 _To ascertain when rye works well._ 61 _To prevent hogsheads from working over._ 62 SECTION IV _Observations on the quality of rye._ 63 _Mode of chopping rye._ 64 Do. _or grinding indian corn._ 65 Do. _malt._ 66 _To choose malt._ 67 _To build a malt-kiln._ 67 _To make malt for stilling._ 69 _Of hops._ 69 SECTION V _How to order and fill the singling still._ 69 _Mode of managing the doubling still._ 71 _On the advantages of making good whiskey._ 73 _Distilling buckwheat._ 77 _Distilling potatoes, with observations._ 78 _Receipt to prepare potatoes for distilling._ 82 _Distilling pumpions._ 83 Do. _turnips._ 83 Do. _apples._ 84 _To order_ do. _in the hogsheads._ 85 _To work_ do. _fast or slow._ 86 _To know when apples are ready for distilling._ 87 _To fill and order the singling still for apples._ 88 _To double apple-brandy._ 90 _To prepare peaches._ 91 _To double and single_ do. 92 SECTION VI _Best mode of setting stills._ 93 _To prevent the planter from cracking._ 98 _Method of boiling more than one still by a single fire._ 99 _To set a doubling still._ 100 _To prevent the singling still from rusting._ 101 SECTION VII _How to clarify whiskey._ 102 _To make a brandy, from rye, spirits or whiskey, to resemble French Brandy._ 103 _To make a spirit from_ ditto, _to resemble Jamaica spirits._ 104 Do. _Holland gin._ 105 Do. _country gin, and clarifying same._ 107 _On fining liquors._ 110 _On coloring liquors._ 111 _To correct the taste of singed whiskey._ 112 _To give an aged flavor._ 113 SECTION VIII _Observations on weather._ 115 Do. _water._ 117 _Precautions against fire._ 119 SECTION IX _Duty of the owner of a distillery._ 120 Do. _of a hired distiller._ 123 SECTION X _The profits arising from a common distillery._ 125 Do. _from a patent distillery._ 127 _Of hogs._ 129 _Diseases of hogs._ 133 _Feeding cattle and milk cows._ 134 SECTION XI _Observations on erecting distilleries._ 135 SECTION XII _On Wines._ 139 _Receipt for making ditto, from the autumn blue grape._ 140 Ditto, _from currants._ 142 Do. _for making cider, British mode._ 143 Do. do. _American mode._ 145 Do. _for an excellent American wine._ 150 Do. do. _honey wine._ 153 _To make elderberry wine._ 156 Do. do. _cordial._ 157 SECTION XIII _Of brewing beer._ 160 _Of the brewing vessels._ 160 _Of cleaning and sweetening casks and brewing vessels._ 161 _Of mashing or raking liquors._ 163 _Of working the liquor._ 167 _Of fining malt liquors._ 170 _Season for brewing._ 172 _To make elderberry beer or ebulum._ 173 _To make improved purl._ 174 _To brew strong beer._ 175 _To make china ale._ 176 _To make any new liquor drink as stale._ 177 _To recover sour ale._ 177 _To recover liquor that is turned bad._ 178 _Directions for bottling._ 178 _To make ale or beer of cooked malt._ 179 _To make treacle (or molasses) beer._ 181 PREFACE. When I first entered on the business of Distilling, I was totally unacquainted with it. I was even so ignorant of the process, as not to know that fermentation was necessary, in producing spirits from grain. I had no idea that fire being put under a still, which, when hot enough, would raise a vapour; or that vapour when raised, could be condensed by a worm or tube passing through water into a liquid state. In short, my impressions were, that chop-rye mixed with water in a hogshead, and let stand for two or three days; and then put into a still, and fire being put under her, would produce the spirit by boiling up into the worm, and to pass through the water in order to cool it, and render it palatable for immediate use--and was certain the whole art and mystery could be learned in two or three weeks, or months at farthest, as I had frequently met with persons who professed a knowledge of the business, which they had acquired in two or three months, and tho' those men were esteemed distillers, and in possession of all the necessary art, in this very abstruse science; I soon found them to be ignorant blockheads, without natural genius, and often, without principle. Thus benighted, and with only the above light and knowledge, I entered into the dark, mysterious and abstruse science of distilling, a business professed to be perfectly understood by many, but in fact not sufficiently understood by any. For it presents a field for the learned, and man of science, for contemplation--that by a judicious and systematic appropriation and exercise of certain elements, valuable and salutary spirits and beverages may be produced in great perfection, and at a small expense, and little inconvenience, on almost every farm in our country. The professed chymist, and profound theorist may smile at my ideas, but should any one of them ever venture to soil a finger in the practical part of distilling, I venture to say, he would find more difficulty in producing good yeast, than in the process of creating oxygen or hydrogen gas. Scientific men generally look down on us, and that is principally owing to the circumstance of so many knaves, blockheads and conceited characters being engaged in the business.--If then, the subject could be improved, I fancy our country would yield all the necessary liquors, and in a state of perfection, to gratify the opulent, and please the epicure. I had no difficulty in finding out a reputed great distiller, whose directions I followed in procuring every necessary ingredient and material for distilling, &c. He was industrious and attentive, and produced tolerable yield, but I soon found the quantity of the runs to vary, and the yield scarcely two days alike. I enquired into the cause, of him, but his answers were, he could not tell; I also enquired of other distillers, and could procure no more satisfactory answer--some attributed it to the water, others to witchcraft, &c. &c. I found them all ignorant--I was equally so, and wandered in the dark; but having commenced the business, I determined to have light on the subject; I thought there must be books containing instructions, but to my surprise, after a diligent search of all the book-stores and catalogues in Pennsylvania, I found there was no American work extant, treating on this science--and those of foreign production, so at variance with our habits, customs, and mode of economy, that I was compelled to abandon all hope of scientific or systematic aid, and move on under the instructions of those distillers of our neighborhood, who were little better informed than myself, but who cheerfully informed me of their experiments, and the results, and freely communicated their opinions and obligingly gave me their receipts. In the course of my progress, I purchased many receipts, and hesitated not to procure information of all who appeared to possess it, and sometimes at a heavy expense, and duly noted down all such discoveries and communications--made my experiments from time to time, and in various seasons, carefully noting down the results. Having made the business my constant and only study, carefully attending to the important branch of making yeast, and studying the cause and progress of fermentation, proceeding with numerous experiments, and always studying to discover the cause of every failure, or change, or difference in the yield. I could, after four years attention, tell the cause of such change, whether in the water, yeast, fermentation, quality of the grain, chopping the grain, or in mashing, and carefully corrected it immediately. By a thus close and indefatigable attention, I brought it to a system, in my mind, and to a degree of perfection, that I am convinced nothing but a long series of practice could have effected. From my record of most improved experiments, I cheerfully gave receipts to those who applied, and after their adoption obtaining some celebrity, I found applications so numerous, as to be troublesome, and to be impossible for me to furnish the demands gratis, of consequence, I was compelled to furnish to some, and refuse others; a conduct so pregnant with partiality, and a degree of illiberality naturally gave rise to murmurs. My friends strongly recommended a publication of them, the plan requiring the exercise of talents, order and method, with which I presumed myself not sufficiently versed, I for sometime obstinately refused, but at length and after reiterated solicitation, I consented to enter on the talk, under a flattering hope of affording useful information to those of my country engaged in the distillation of spirits from the growth of our native soil, which together with the following reasons, I offer as the only apology. 1st. I observed many distillers making fortunes, whilst others exercising an equal share of industry, and of equal merit were sinking money, owing to a want of knowledge in the business. 2d. In taverns I often observed foreign liquors drank in preference to those of domestic manufacture, though really of bad quality, possessing pernicious properties acquired from ingredients used by those in our commercial towns, who brew and compose brandies, spirits, and wines, often from materials most injurious to health, and this owing to so much bad liquor being made in our country, from which the reputation of domestic spirit has sunk. Whilst, in fact, we can make domestic spirits of various materials, which with a little management and age, will be superior to any of foreign produce. 3d. By making gin, &c. as good if not better, we might in a few years, meet those foreign merchants in their own markets, and undersell them; which we certainly could do, by making our liquors good, and giving them the same age. The transportation would of consequence improve them in an equal degree, for the only advantage their liquors of the same age have over our good liquors, is the mildness acquired by the friction in the warm hold of the ship in crossing the ocean. And moreover as liquors will be drank by people of all standings in society, I flattered myself I could improve our liquors, render them more wholesome to those whose unhappy habits compel a too free use of ardent spirits, and whose constitutions may have been doubly injured from the pernicious qualities of such as they were compelled to use. For there are in all societies and of both sexes, who will drink and use those beverages to excess, even when there exists a moral certainty, that they will sustain injury from such indulgence, and as an evidence of my hypothesis, I offer the free use of coffee, tea, &c. so universally introduced at the tables of people of every grade. The wise Disposer of worlds, very happily for mankind, permits the exhibition of genius, mind and talents, from the peasant and lower order, as well as from the monarch, the lord, and the opulent. To Europe they of course are not confined--Genius has already figured in our hemisphere--The arts and sciences are becoming familiar, they rise spontaneously from our native soil, and bid fair to vie with, if not out-shine accomplished Europe. In possession, then, of all the necessary materials, ingredients and requisites, I would ask why we cannot afford ardent spirits and wines equal to those imported; and thus raise our character to a standing with other countries, and retain those millions of dollars at home, which are yearly shipped abroad for those foreign liquors, so common, so universally in use, and much of which so adulterated, as to be followed, when freely used, with unhappy consequences. Would men of capital and science, turn their attention to distillations, from the produce of our own country, preserve the liquor until age and management would render it equal, if not superior to any imported; is it not probable that it would become an article of export, and most sensibly benefit our country at large. Considerations such as those have combined to determine a publication of my work; fully apprised of the scoffs of pedants, kicks, bites and bruises of critics--but I hope they will find latitude for the exercise of a share of compassion, when I inform them candidly, that a mill and distillery, or still house, were substituted for, and the only college and academy in which I ever studied, and those studies were broken, and during the exercise of my business, as a miller and distiller. That it contains errors in the diction and perspicuity, I will readily confess--but that it is in substance true, and contains much useful information, I must declare as an indisputable fact. And though the road I travelled was a new one, without compass, chart, or even star to steer by, not even a book to assist me in thinking, or cheer me in my gloomy passage--seeking from those springs of nature, and inherent endowments for consolatory aid--pressing on a frequently exhausted mind, for resources and funds, to accomplish the objects of my pursuits--not denying but that I met many of my fellow-beings, who cheerfully aided me with all the information in their power, and to whom I now present my thanks--I must acknowledge, I think my labors and exertions will prove useful to those of less experience than mine, in which event I shall feel a more ample remuneration for my exertions, than the price asked for one of those volumes. Could I have witnessed the publication of a similar work by a man of science and education, mine should never have appeared. But it would seem the learned and scientific have never considered a work of the kind as meriting their attention; a circumstance deeply to be regretted, as a finer colouring to a work of the same properties and value often procures celebrity, demand and currency. My object is to be useful, my style plain, and only laboured to be rendered easy to be understood, and convey the necessary instruction to those who may honor this work with a perusal, or resort to it for information, and that it may be useful to my countrymen, is the sincere wish of THE AUTHOR. INTRODUCTION. It is not more than twenty years since whiskey was first offered for sale in the seaport towns in large quantities; and then, owing to its badness, at a very low price. Since that period it has been gaining ground yearly, and at this time, it is the second great article of commerce, in the states of Pennsylvania and Maryland. In the interior of these states, it has nearly excluded the use of foreign distilled spirits, and I fancy might be made so perfectly pure and nice, as to ultimately supersede the use of any other throughout the United States. To assist in effecting this, the greatest attention should be paid to cleanliness, which in a distillery is absolutely necessary, the want of which admits of no excuse, where water is had without price. If a distiller does not by a most industrious well-timed care and attention, preserve every utensil perfectly sweet and clean, he may expect, notwithstanding he has well attended to the other branches, but indifferent whiskey and not much of it. If, for instance, every article, or only one article in the composition of yeast be sour or dirty, that one article will most assuredly injure the whole; which being put into a hogshead of mashed grain, soon imparts its acidity or filth to the whole mass, and of course will reduce the quantity and quality of the spirit yielded from that hogshead. Cleanliness in every matter and thing, in and about a distillery becomes an indispensable requisite, without a strict observance of which the undertaker will find the establishment unproductive and injurious to his interest. Purity cannot exist without cleanliness. Cleanliness in the human system will destroy an obstinate itch, of consequence, it is the active handmaid of health and comfort, and without which, decency does not exist. Care is another important and necessary consideration, and a basis necessary, on which to erect a distillery, in order to ensure it productive of wealth and reputation. Care and industry will ensure cleanliness; an eye of care must be extended to every thing, that nothing be lost, that every thing be in its proper place and order, that every thing be done in due time; the business must be well timed, and time well economised, as it ranks in this, as in every other business very high. Let a judicious attention be paid to care, cleanliness, and industry, and when united with a competent knowledge of the different branches of the distilling business, the character of a compleat practical distiller is perfect. With such a distiller, and a complete still-house, furnished with every necessary utensil for carrying on the business--it cannot fail to prove a very productive establishment, and present to the world, from the materials of our own farms, a spirit as wholesome, and well flavored and as healthy as any spirit whatever--the produce or yield of any country, provided it be permitted to acquire the same age. What a grand and great idea strikes the thinking scientific mind, on entering a complete and clean distillery, with an intelligent cleanly distiller, performing his duty in it. To see the four elements, each combining to produce (with the assistance of man) an article of commerce and luxury, and at the same time, a necessary beverage to man. The earth producing the grain, hops and utensils, which a combination of fire and water reduces into a liquid by fermentation, and when placed in the still to see air engaging fire to assist her in reducing the liquid that fire and water had produced, into a vapour, or air, and afterwards to see fire abandoning air, and assisting water to reduce it into a liquid by means of the condensing tubes, and then to consider the number of hands employed in keeping the distillery a going, will present one other patriotic idea. The farmer with all his domestics and people, engaged in the cultivation of the rye, corn, &c. The wood choppers--the haling--the coopers engaged in making casks--the hands engaged in feeding cattle and the pork--haling, barrelling and selling the whiskey, spirits, pork, &c. The produce of the distillery, presenting subject for commerce, and employ for the merchant, mechanic and mariner--and all from our own farms. After seeing the distillery afford employment for so many hands, bread to their families, and yielding the means of an extensive revenue and increase of commerce--with a flattering prospect of completely annihilating the use of foreign liquors in our country, and thereby saving the expenditure of millions of dollars; and ultimately rendering our liquors an article of export and source of wealth--I presume every mind will be struck with the propriety of encouraging a branch of business so promising in wealth and comfort. The following receipts are intended to convey all the instruction necessary in the science of distilling, and producing from the growth of our own farms, the best spirits of every description, and such as I flatter myself will supersede the use of all imported liquors, and thereby fulfil the views and wishes of THE AUTHOR. PRACTICAL DISTILLER. SECTION I. _Observations on Yeast._ That yeast is the main spring in distilling, is acknowledged by all distillers, tho' but few if them understand it, either in its nature or operation; tho' many pretend a knowledge of the grand subject of fermentation, and affect to understand the best mode of making stock yeast, and to know a secret mode unknown to all others--when it is my belief they know very little about it; but, by holding out the idea of adding some drug, not to be procured at every house, which has a hard name, and that is little known to people of common capacities: Such as Dragons blood, &c. frequently retailing their secret, as the best possible mode of making stock yeast, at ten, twenty, and in some instances one hundred dollars. Confessing it a subject, abstruse, and a science little understood in Pennsylvania, and notwithstanding the numerous experiments I have made with care and close observation, yet from a consciousness of not understanding it, _too well_, I have in several instances purchased receipts, and made faithful experiments; but have never yet met the man of science, theory, or practice, whose mode of making stock yeast, yielded a better preparation for promoting fermentation, than the simple mode pursued by myself for some years, and which I have uniformly found to be the best and most productive. In making yeast, all drugs and witchcraft are unnecessary--Cleanliness, in preserving the vessels perfectly sweet, good malt, and hops, and an industrious distiller, capable of observation, and attention to the following receipt, which will be assuredly found to contain the essence and spirit of the ways and art of making that composition, a knowledge of which I have acquired, by purchases--consultations with the most eminent brewers, bakers, and distillers in this commonwealth, and above all, from a long practice and experience, proving its utility and superior merits to my most perfect satisfaction; and which I with pleasure offer to my fellow-citizens, as meriting a preference--notwithstanding the proud and scientific chymist, and the flowery declarations or treatises of the profound theorist, may disapprove this simple mode, and offer those which they presume to be better, tho' they never soiled a finger in making a practical experiment, or perhaps witnessed a process of any description. ARTICLE II. _Receipt for Stock Yeast._ _For a stock yeast vessel of two gallons, the size best adapted for that purpose._ Take one gallon good barley malt, (be sure it be of good quality) put it into a clean, well scalded vessel, (which take care shall be perfectly sweet) pour thereon four gallons scalding water, (be careful your water be clean) stir the malt and water with a well scalded stick, until thoroughly mixed together, then cover the vessel close with a clean cloth, for half an hour; then uncover it and set it in some convenient place to settle, after three or four hours, or when you are sure the sediment of the malt is settled to the bottom, then pour off the top, or thin part that remains on the top, into a clean well scoured iron pot, (be careful not to disturb the thick sediment in the bottom, and that none of it goes into the pot); then add four ounces good hops, and cover the pot close with a clean scalded iron cover, and set it on a hot fire of coals to boil--boil it down one third, or rather more, then strain all that is in the pot through a thin hair sieve, (that is perfectly clean) into a clean well scalded earthen crock that is glazed--then stir into it, with a clean stirring stick, as much superfine flour as will make it about half thick, that is neither thick nor thin, but between the two, stirring it effectually until there be no lumps left in it. If lumps are left, you will readily perceive that the heart or inside of those lumps will not be scalded, and of course, when the yeast begins to work, those lumps will sour very soon, and of course sour the yeast--stir it then till those lumps are all broken, and mixed up, then cover it close for half an hour, to let the flour stirred therein, be properly scalded, after which uncover and stir it frequently until it is a little colder than milk warm, (to be ascertained by holding your finger therein for ten minutes, but beware your finger is clean) then add half a pint of genuine good yeast,[1] (be certain it is good, for you had better use none, than bad yeast) and stir it effectually, until you are sure the yeast is perfectly incorporated with the ingredients in the pot--after which cover it, and set it in a moderately cool place in summer, until you perceive it begin to work, or ferment--then be careful to stir it two or three times at intervals of half an hour--then set it past to work--in the winter, place it in a moderately warm part of the still-house--and in summer, choose a spring house, almost up to the brim of the crock in water--avoiding extremes of heat or cold, which are equally prejudicial to the spirit of fermentation--of consequence, it should be placed in a moderately warm situation in the winter, and moderately cool in the summer. [Footnote 1: If none can be obtained that is good, the following is a receipt to make it, viz. Procure three wooden vessels of different sizes and apertures, one capable of holding two quarts, the other three or four, and the third five or six; boil a quarter of a peck of malt for about eight or ten minutes in three pints of water; and when a quart is poured off from the grains, let it stand in a cool place till not quite cold, but retaining that degree of heat which the brewers usually find to be proper when they begin to work their liquor. Then remove the vessel into some warm situation near a fire, where the thermometer stands between 70 and 80 degrees (Fahrenheit,) and here let it remain till the fermentation begins, which will be plainly perceived within thirty hours; add then two quarts more of a like decoction of malt, when cool, as the first was; and mix the whole in the larger sized vessel, and stir it well in, which must be repeated in the usual way, as it rises in a common vat: then add a still greater quantity of the same decoction, to be worked in the largest vessel, which will produce yeast enough for a brewing of forty gallons.] This yeast ought to be renewed every four or five days in the summer, and eight or ten days in the winter--but it is safer to renew it oftener, or at shorter intervals, than suffering it to stand longer. In twenty-four hours after it begins to work, it is fit for use. Between a pint and half a pint of the foregoing stock yeast, is sufficient to raise the yeast for the daily use of three hogsheads. ART. III. The most proper vessel for preserving stock yeast is an earthen crock, that will hold three gallons at least, with a cover of the same, well glazed--as it will contract no acid from the fermentation, and is easily scalded and sweetened. There ought to be two of the same size, that when one is in use, the other may be sweetening--which is effected by exposing them to frost or fire. ART. IV. _To know when Yeast is good or bad._ When you perceive your yeast working, observe if it works quick, sharp and strong, and increasing in bulk nearly double what it was before it began to work, with a sweet sharp taste, and smell, with the appearance of a honey comb, with pores, and always changing place, with a bright lively colour, then you may pronounce your yeast good; on the contrary, if it is dead, or flat and blue looking, with a sour taste, and smell, (if any at all,) then you may pronounce it bad, and unfit for use, and of course must be renewed. ART. V. _How to renew Yeast when sour._ About two hours before you begin to make your beer, take one pint of the sour yeast, put it into a clean dish or vessel, and pour clean cold water over it--changing the water every fifteen minutes, until the acid be extracted, have it then in readiness to mix with the beer, which is to be prepared, in the following manner, viz. Take one pint malt, and scald it well in a clean vessel, with a gallon of boiling water, let it stand half an hour closely covered--then pour it into a pot with plenty of hops--then strain it into a well scalded earthen jug, when milk warm--add then a small quantity of the yeast, (sweetened as directed in the first part of this receipt,) with two or three table spoon fulls of molasses ... set it past for twenty four hours to ferment ... then pour off the top, or beer that is in the jug, leaving about a quart in the bottom ... then that which remains in the bottom will be yeast with which to start your stock yeast. ART. VI. The method of procuring and keeping stock yeast, by the generality of distillers, merits in the mind of the author of this work, most decided disapprobation. They generally procure yeast once a week, or month, from brewers, and if not convenient to be had in this way, they often use such as is used by country women, for baking bread, without paying any regard to the quality, or whether sour; with such, tho' generally bad, they proceed to make their daily yeast, and often continue the use of it, until the grain will no longer yield a gallon of whiskey to the bushel, and so often proceed in this miserable and indolent mode of procuring and renewing yeast, to the great prejudice of their own, and employer's interest ... attributing the small yield of liquor to the badness of the grain ... the manner in which it is chopped, or some other equally false cause. Then to the idle and careless habits of distillers, must be attributed any yield short of three gallons to the bushel of rye.... To ensure this quantity at least from the bushel, the author discovers the anxiety expressed, and the care recommended in the foregoing pages, on the subject of preserving and keeping good yeast, and recommends the following as the best mode of preparing. ART. VII. _Stock Yeast good for years._ When the weather is moderately warm in autumn or the spring, take of your best stock yeast that has fermented about twenty four hours, and stir it thick with the coarsest middlings of wheat flour, add small quantity of whiskey, in which, previously dissolve a little salt, when you have stirred the middlings with a stick, rub it between your hands until it becomes pretty dry, then spread it out thin, on a board to dry in the sun ... rubbing once or twice in the day between your hands until it is perfectly dry, which will be in three or four good days--taking it in at night before the dew falls--when it is properly dried, put it up in a paper and keep it in a dry airy place for use. Thus yeast will keep good, if free from moisture, for any length of time, and it is the only effectual mode of preserving stock yeast pure and sweet ... when put up conformably to the foregoing instructions, the distiller may always rely on having it good, and depend on a good turn out of his grain, provided he manages the other parts of his distilling equally well. About two hours before you mean to use the dried yeast, the mode is to take two gills, place it in any convenient vessel, and pour thereon milk-warm water, stir and mix it well with the yeast, and in two or three hours good working yeast will be produced. In the spring every distiller ought to make as much as would serve 'till fall, and every fall as much as will serve thro' the winter, reckoning on the use of one pint per week, three gills being sufficient to start as much stock yeast as will serve a common distillery one week. ART. VIII. _To make the best Yeast for daily use._ For three hogsheads take two handfuls of hops, put them into an iron pot, and pour thereon three gallons boiling water out of your boiler, set the pot on the fire closely covered half an hour, to extract the strength from the hops, then strain it into your yeast vessel, thicken it with chopped rye, from which the bran has been sifted ... stir it with a clean stick until the lumps are all well broken and mixed ... cover it close with a cloth for half an hour, adding at the time of putting in the chopped rye, one pint of good malt when the rye is sufficiently scalded, uncover and stir it well until it is milk-warm, then add one pint good stock yeast, stirring until you are sure it is well mixed with the new yeast. If your stock yeast is good, this method will serve you ... observing always, that your water and vessels are clean, and the ingredients of a good quality; as soon as you have cooled off and emptied your yeast vessel, scald and scour, and expose it to the night air to purify. Tin makes the best yeast vessel for yeast made daily, in the above mode. In the course of my long practice in distilling I fully discovered that a nice attention to yeast is absolutely necessary, and altho' I have in the foregoing pages said a great deal on the subject, yet from the importance justly to be attached to this ingredient in distilling, and to shew more fully the advantages and disadvantages arising from the use of good and bad yeast, I submit the following statement for the consideration of my readers. Advantages in using good yeast for one month, at 5 bushels per day; 30 days at 5 bushels, is 150 bushels at 60 cents, costs $ 90 00 Contra 150 bushels yield 3 gallons per bushel, at 50 cents per gallon--450 gallons, 225 00 -------- Profit $ 135 00 Disadvantages sustained during the above period. 150 bushels at 60 cents, $ 90 00 Contra 150 bushes yielding 1-1/2 gallons to the bushel--225 gallons at 50 cents, 112 50 ------- Profit $ 21 50 Thus the owner or distiller frequently sustains in the distillation of his produce, a loss, equal and in proportion to the foregoing--from the use of indifferent yeast, and often without knowing to what cause to attribute it. This statement will shew more forcibly, than any other mode--and is made very moderate on the side of indifferent yeast, for with bad sour yeast the yield will be oftener under one gallon to the bushel than above one and an half--whereas with good yeast the yield will rarely be so low as three gallons to the bushel. It is therefore, I endeavor so strongly to persuade the distiller to pay every possible attention to the foregoing instructions, and the constant use of good yeast only, to the total rejection of all which may be of doubtful quality. SECTION II. ARTICLE I. _Observations on Wood for Hogsheads._ The cheapest and easiest wrought wood is generally most used for making mashing tubs, or hogsheads, and very often for dispatch or from necessity, any wood that is most convenient is taken, as pine or chesnut; indeed I have seen poplar tubs in use for mashing, which is very wrong, as a distiller by not having his hogsheads of good wood, may lose perhaps the price of two sets of hogsheads in one season. For instance, a farmer is about to erect a distillery, and is convenient to a mountain, abounding in chesnut or pine, which from its softness and the ease with which it may be worked, its convenience for dispatch sake, is readily chosen for his mashing hogsheads.--To such selection of wood, I offer my most decided disapprobation, from my long experience, I know that any kind of soft wood will not do in warm weather. Soft porus wood made up into mashing tubs when full of beer and under fermentation, will contract, receive or soak in so much acid, as to penetrate nearly thro' the stave, and sour the vessel to such a degree, in warm weather, that no scalding will take it out--nor can it be completely sweetened until filled with cold water for two or three days, and then scalded; I therefore strongly recommend the use of, as most proper _White Oak._ Disapproving of black, tho' next in order to white oak staves for all the vessels about the distillery ... as being the most durable of close texture, easily sweetened ... and hard to be penetrated by acids of any kind, tho' sometimes the best white oak hogsheads may sour, but two or three scaldings will render them perfectly sweet ... if white oak cannot be had, black oak being of the next best in quality may be used ... and again I enter my protest against pine, chesnut, poplar, and every kind of soft porus wood. If possible, or if at all convenient, have the vessels iron bound and painted, to prevent worms and the weather from injuring them, using one good wood hoop on the bottom to save the chine. ART. II. _To sweeten Hogsheads by scalding._ When you turn your vessels out of doors (for it is esteemed slothful and a lazy mode to scald them in the still house,) you must wash them clean with your scrubbing brush, then put in sixteen or twenty gallons boiling water--cover it close for about twenty minutes, then scrub it out effectually with your scrubbing broom, then rinse your vessel well with a couple buckets clean cold water, and set them out to receive the air--this method will do in the winter, provided they are left out in the frost over night--but in summer, and especially during the months of July and August, this mode will not do--it is during those extreme warm months in our latitude, that the vessels are liable to contract putrid particles, which may be corrected by the following mode of making _Hogsheads perfectly sweet._ Scald them twice, as above directed, then light a brimstone match, flick it on the ground, turn your hogshead down over it, let it stand until the match quits burning, this operation is necessary once a week--a method I have found effectual. ART. III. _To sweeten Hogsheads by burning._ When you have scalded your hogsheads well, put into each, a large handful of oat or rye straw, set it on fire, and stir it till it is in a blaze, then turn the mouth of the hogshead down; the smoke will purify and sweeten the cask. This process should be repeated every other day, especially during summer--it will afford you good working casks, provided your yeast be good, and your hogsheads are well mashed. There ought always to be in a distillery more vessels than are necessary for immediate use, that they may alternately be exposed to the frost and air one night at least before brought into service, always bearing in mind that the utmost attention to cleanliness is necessary, in order to afford such yield from the grain, or fruit, as may be requisite to compensate for the expense and labor of extracting spirits--and moreover, that the exercise of the finest genius possessed by man is scarcely capable of taking from small grain, all the spirit it contains:.... good materials will not suffice ... the most marked attention is indispensably necessary to yeast; a mind capable of judging of fermentation in all its stages ... a close adherence to the manner of using the ingredients ... preparing them, and the use of sweet vessels, with great industry and a knowledge to apply it at the proper moment, are all necessary to enable the accomplishment of the desired end. Note ... In scalding your hogshead I would recommend the use of a shovel full of ashes, which will scald more sharply. SECTION III. ARTICLE I. _To Mash Rye in the common mode._ Take four gallons cold water to each hogshead, add one gallon malt, stir it well with your mashing stick, until the malt is thoroughly wet--when your still boils, put in about sixteen gallons boiling water, then put in one and an half bushels of chopped rye, stirring it effectually, until there is no lumps in it, then cover it close until the still boils, then put in each hogshead, three buckets or twelve gallons boiling water, stirring it well at the same time--cover it close--stir it at intervals until you perceive your rye is scalded enough, which you will know by putting in your mashing stick, and lifting thereon some of the scalded rye, you will perceive the heart or seed of the rye, like a grain of timothy seed sticking to the stick, and no appearance of mush, when I presume it will be sufficiently scalded--it must then be stirred until the water is cold enough to cool off, or you may add one bucket or four gallons of cold water to each hogshead, to stop the scalding. I have known this process succeed well with an attentive distiller. ART. II. _The best method of distilling Rye._ Take four gallons boiling, and two gallons cold water--put it into a hogshead, then stir in one and a half bushels chopped rye, let it stand five minutes, then add two gallons cold water, and one gallon malt, stir it effectually--let it stand till your still boils, then add sixteen gallons boiling water, stirring it well, or until you break all the lumps--then put into each hogshead, so prepared, one pint coarse salt, and one shovel full of hot coals out of your furnace. (The coals and salt have a tendency to absorb all sourness and bad smell, that may be in the hogshead or grain;) if there be a small quantity of hot ashes in the coals, it is an improvement--stir your hogsheads effectually every fifteen minutes, keeping them close covered until you perceive the grain scalded enough--when you may uncover, if the above sixteen gallons boiling water did not scald it sufficiently, water must be added until scalded enough--as some water will scald quicker than others--it is necessary to mark this attentively, and in mashing two or three times, it may be correctly ascertained what quantity of the kind of water used will scald effectually--after taking off the covers, they must be stirred effectually, every fifteen minutes, till you cool off--for which operation, see "_Cooling off._" To those who distill all rye, I recommend this method, as I have found it to answer every kind of water, with one or two exceptions. Distillers will doubtless make experiments of the various modes recommended and use that which may prove most advantageous and convenient. ART. III. _To Mash two thirds Rye and one third Corn in Summer._ This I have found to be the nicest process belonging to distilling--the small proportion of corn, and the large quantity of scalding water, together with the easy scalding of rye, and the difficulty of scalding corn, makes it no easy matter to exactly hit the scald of both; but as some distillers continue to practice it, (altho' not a good method in my mind, owing to the extreme nice attention necessary in performing it.) In the following receipt I offer the best mode within my knowledge, and which I deem the most beneficial, and in which I shew the process and mode pursued by other distillers. Take four gallons cold water, put it into a hogshead, then stir half a bushel corn into it, let it stand uncovered thirty minutes, then add sixteen gallons boiling water, stir it well, cover it close for fifteen minutes, then put in your rye and malt and stir it until there be no lumps, then cover it and stir it at intervals until your still boils, then add, eight, twelve, or sixteen gallons boiling water, or such quantity as you find from experience, to answer best--(but with most water, twelve gallons will be found to answer) stirring it well every fifteen minutes until you perceive it is scalded enough, then uncover and stir it effectually until you cool off; keeping in mind always that the more effectually you stir it, the more whiskey will be yielded. This method I have found to answer best, however, I have known it to do very well, by soaking the corn in the first place, with two gallons warm, and two gallons cold water, instead of the four gallons of cold water, mentioned above--others put in the rye, when all the boiling water is in the hogshead, but I never found it to answer a good purpose, nor indeed did I ever find much profit in distilling rye and corn in this proportion. ART. IV. _To distill one half Rye and one half Corn._ This method of distilling equal quantities of rye and corn, is more in practice, and is much better than to distill unequal proportions, for reason you can scald your corn and rye to a certainty, and the produce is equal if not more, and better whiskey, than all rye. The indian corn is cheaper, and the seed is better than if all rye. I would recommend this, as the smallest quantity of corn to be mixed with rye for distillation, as being most productive, and profitable. The following receipt I have found to answer all waters--yet there may be places where the distiller cannot follow this receipt exactly, owing to hard or soft water, (as it is generally termed) or hard flint or soft floury corn, that will either scald too much or too little--but this the attentive distiller will soon determine by experience. Have your hogshead perfectly sweet, put into each, three gallons of cold and three of boiling water, or more or less of each, as you find will answer best--then stir in your corn--fill up your boiler, bring it briskly to a boil--then put to each hogshead twelve gallons boiling water, giving each hogshead one hundred stirs, with your mashing stick, then cover close, fill up your boiler and keep a good fire under her, to produce a speedy boil; before you add the last water, put into each hogshead one pint of salt, and a shovel full of hot coals and ashes from under your still, stir the salt and coals well, to mix it with your corn, the coal will remove any bad smell which may be in the hogshead--Should you find on trial, that rye don't scald enough, by putting it in after your last water, you may in that case put in your rye before the last water--but this should be ascertained from several experiments. I have found it to answer best to put in the rye after all the water is in the hogshead, especially if you always bring the still briskly to a boil--then on your corn put twelve or sixteen gallons boiling water, (for the last water,) then if you have not already mashed in your rye, put it in with one gallon good malt to each hogshead, carefully stirring it immediately very briskly, for fear of the water loosing its heat, and until the lumps are all broken, which you will discover by looking at your mashing stick; lumps generally stick to it. When done stirring, cover the hogshead close for half an hour, then stir it to ascertain whether your grain be sufficiently scalded, and when nearly scalded enough, uncover and stir steady until you have it cool enough to stop scalding; when you see it is scalded enough, and by stirring that the scalding is stopped, uncover your hogsheads, and stir them effectually, every fifteen minutes, until they are fit to cool off--remembering that sweet good yeast, clean sweet hogsheads, with this mode of mashing carefully, will produce you a good turn out of your grain. The quantity of corn and rye is generally two stroked half bushels of each, and one gallon malt. ART. V. _To Mash one third Rye and two thirds Corn._ This I deem the most profitable mashing that a distiller can work, and if he can get completely in the way of working corn and rye in this proportion, he will find it the easiest process of mashing. That corn has as much and as good whiskey as rye or any other grain, cannot be disputed, and the slop or pot ale is much superior to that of any other grain, for feeding or fattening either horned cattle or hogs--one gallon of corn pot ale being esteemed worth three of rye, and cattle will always eat it better--and moreover, corn is always from one to two shillings per bushel cheaper than rye, and in many places much plentier--so that by adopting this method and performing it well, the distiller will find at the close of the year, it has advantages over all other processes and mixtures of rye and corn, yielding more profit, and sustaining the flock better. Hogs fatted on this pot ale, will be found decidedly better than any fatted on the slops of any other kind of mashing. _Mash as follows._ Have sweet hogsheads, good yeast and clean water in your boiler; when the water is sharp, warm, or half boiling, put into every hogshead you mean to mash at the same time, six, eight or as many gallons of the half boiling water, as will completely wet one bushel corn meal--add then one bushel chopped corn, stir it with your mashing stick till your corn is all wet; it is better to put in a less quantity of water first, and so add as you may find necessary, until completely wet (be careful in all mashings, that your mashing stick be clean), this is called soaking the corn. Then fill up your boiler, bring her quickly to a boil, when effectually boiling, put into every hogshead, twelve gallons boiling water, stirring it well after putting in each bucket, until the lumps are quite broken--cover the hogsheads close, after a complete stirring--fill up your boiler, bring her quickly to boil for the last mashing--stir the corn in the hogshead every fifteen minutes, till your last water is boiling--put into each hogshead one pint salt, and a shovel full of red hot coals, stirring it well--then put in each hogshead sixteen gallons of boiling water, stir it well--cover it close for twenty-five minutes--then put into each hogshead one half bushel rye meal, and one gallon good chopped malt, stirring it until the lumps are all broken, then cover it close, stir it every half hour, until you perceive it sufficiently scalded--then uncover it and stir it as often as your other business will permit, until ready to cool off. In this and every other mashing you must use sweet vessels only and good yeast, or your labor will be in vain; and in all kinds of mashing you cannot stir too much. ART. VI. _To Mash Corn._ This is an unprofitable and unproductive mode of mashing, but there may be some times when the distiller is out of rye, on account of the mill being stopped, bad roads, bad weather, or some other cause; and to avoid the necessity of feeding raw grain to the hogs or cattle, (presuming every distillery to be depended on for supplying a stock of some kind, and often as a great reliance for a large stock of cattle and hogs,) in cold weather I have found it answer very well, but in warm weather it will not do. Those who may be compelled then from the above causes, or led to it by fancy, may try the following method. To one hogshead, put twelve gallons boiling water, and one and an half bushels corn, stir it well, then when your water boils, add twelve gallons more, (boiling hot,) stir it well, and cover it close, until the still boils the third time, then put in each hogshead, one quart of salt, and sixteen gallons boiling water, stir it effectually, cover it close until you perceive it nearly scalded enough, then put in two, or three gallons cold water, (as you will find to answer best,) and two gallons malt, or more if it can be spared--stir it well, then cover it for half an hour, then uncover and stir it well, until cold enough to cool off. ART. VII. _To make four gallons from the bushel._ This is a method of mashing that I much approve of, and recommend to all whiskey distillers to try it--it is easy in process, and is very little more trouble than the common method, and may be done in every way of mashing, as well with corn or rye, as also a mixture of each, for eight months in the year; and for the other four is worth the trouble of following. I do not mean to say that the quantity of four gallons can be made at an average, in every distillery, with every sort of grain, and water, or during every vicissitude of weather, and by every distiller, but this far I will venture to say, that a still house that is kept in complete order, with good water, grain well chopped, good malt, hops, and above all good yeast; together with an apt, careful and industrious distiller, cannot fail to produce at an average for eight months in the year, three and three quarter gallons from the bushel at a moderate calculation. I have known it sometimes produce four and an half gallons to the bushel, for two or three days, and sometimes for as many weeks, when perhaps, the third or fourth day, or week, it would scarcely yield three gallons; a change we must account for, in a change of weather, the water or the neglect or ignorance of the distiller. For instance, we know that four gallons of whiskey is in the bushel of rye or corn--certain, that this quantity has been made from the bushel; then why not always? Because, is the answer, there is something wrong, sour yeast or hogsheads, neglect of duty in the distiller, change of grain, or change of weather--then of course it is the duty of the distiller to guard against all these causes as near as he can. The following method, if it does not produce in every distillery the quantity above mentioned, will certainly produce more whiskey from the bushel, than any other mode I have ever known pursued. Mash your grain in the method that you find will yield you most whiskey--the day before you intend mashing, have a clean hogshead set in a convenient part of the distillery; when your singling still is run off, take the head off and fill her up with clean water, let her stand half an hour, to let the thick part settle to the bottom, which it will do when settled, dip out with a gallon or pail, and fill the clean hogshead half full, let the hogshead stand until it cools a little, so that when you fill it up with cool water, it will be about milk-warm, then yeast it off with the yeast for making 4 gallons to the bushel, then cover it close, and let it work or ferment until the day following, when you are going to cool off; when the cold water is running into your hogshead of mashed stuff, take the one third of this hogshead to every hogshead, (the above being calculated for three hogsheads) to be mashed every day, stirring the hogsheads well before you yeast them off. This process is simple, and I flatter myself will be found worthy of the trouble. ART. VIII. _To know when Grain is scalded enough._ Put your mashing stick into your hogshead and stir it round two or three times gently, then lift it out and give it a gentle stroke on the edge of your hogshead--if you perceive the batter or musky part fall off your stick, and there remains the heart of the grain on your mashing stick, like grains of timothy seed, then be assured that it is sufficiently scalded, if not too much, this hint will suffice to the new beginner, but experience and observation will enable the most correct judgment. ART. IX. _Directions for cooling off._ Much observation is necessary to enable the distiller to cool off with judgment--which necessity is increased by the versatility of our climate, the seasons of the year, and the kinds of water used. These circumstances prevent a strict adherence to any particular or specific mode; I however submit a few observations for the guidance of distillers in this branch.--If in summer you go to cool off with cold spring water, then of course the mashed stuff in your hogsheads must be much warmer, than if you intended cooling off with creek or river water, both of which are generally near milk warm, which is the proper heat for cooling off--In summer a little cooler, and in winter a little warmer. It will be found that a hogshead of mashed grain will always get warmer, after it begins to work or ferment. When the mashed stuff in your hogsheads is brought to a certain degree of heat, by stirring, which in summer will feel sharp warm, or so warm, that you can hardly bear your hand in it for any length of time, will do for common water, but for very cold or very warm water to cool off with, the stuff in the hogsheads must be left colder or warmer, as the distiller may think most expedient, or to best suit the cooling off water. When you think it is time to cool off, have a trough or conveyance to bring the water to your hogsheads ready--let the hogsheads be well stirred, then let the water run into them slowly, stirring them all the time the water is running in, until they are milk warm, then stop the water, and after stirring them perfectly, put in the yeast and stir it until completely incorporated with the mashed stuff, then cover your hogshead until it begins to ferment or work, then uncover it. ART. X. _To ascertain when Rye works well in the Hogshead._ When mashed rye begins to work or ferment in the hogsheads, either in a heavy, thick, or light bubbly top, both of which are unfavorable; when it rises in a thick heavy top, you may be sure there is something wrong, either in the grain, yeast, or cooling off. When the top (as called by distillers) appear, with bubbles about the size of a nutmeg, rising and falling alternately, with the top not too thick nor too thin, and with the appearance of waves, mixed with the grain in the hogshead, rising and falling in succession, and when you put your head over the steam, and it flying into your nose, will have a suffocating effect, or when it will instantly extinguish a candle when held over it, you may feel assured, it is working well. From these hints and the experience of the distiller, a judgment may be formed of the state of fermentation and the quality. ART. XI. _To prevent Hogsheads from working over._ If the stuff is cooled off too warm, or too much yeast is put in the hogsheads, they will work over, and of course lose a great deal of spirit, to prevent which, take tallow and rub round the chine of the hogsheads a little higher than they ought to work; it will generally prevent them from rising any higher, but if they will work over in spite of this remedy, then drop a little tallow into the stuff, it will immediately sink the stuff to a proper height. SECTION IV. ARTICLE I. _Observations on the quality of Rye for distilling._ The best rye for distilling is that which is thoroughly ripe, before it is cut, and kept dry till threshed; if it has grown on high or hilly ground, it is therefore to be preferred, being then sounder and the grain fuller, than that produced on low level land--but very often the distiller has no choice, but must take that which is most convenient;--great care however ought to be observed in selecting sound rye, that has been kept dry, is clean and free from cockle, and all kind of dirt, advantages will result from fanning it, or running it through a windmill before it is chopped. ART. II. _Mode of chopping Rye and the proper size._ The mill stones ought to be burrs, and kept very sharp for chopping rye for distillation; and the miller ought to be careful not to draw more water on the wheel than just sufficient to do it well, and avoid feeding the stones plentifully; because in drawing a plentiful supply of water, the wheel will compel a too rapid movement of the stones, of course render it necessary they should be more abundantly fed, which causes part to be ground dead, or too fine, whilst part thereof will be too coarse, and not sufficiently broken, so that a difficulty arises in scalding--for in this state it will not scald equally, and of consequence, the fermentation cannot be so good or regular; and moreover as part of it will merely be flattened, a greater difficulty will arise in breaking the lumps, when you mash and stir your hogsheads. If burr stones are very sharp, I recommend the rye to be chopped very fine, but to guard against over-seeding, or pressing too much on them; but if the stones are not sharp, I would recommend the rye should be chopped about half fine. Distillers in general sustain a loss from having their rye chopped so coarse as I have observed it done in common. ART. III. _Chopping or Grinding Indian Corn._ Indian corn cannot be ground too fine for distilling. ART. IV. _Malt_ Cannot be ground too coarse, provided it is done even--there ought to be no fine nor coarse grains in malt, but ground perfectly alike, and of the same grade. If ground too fine, it will be apt to be scalded too much in mashing. Malt does not require half the scalding necessary in rye. Let the distiller try the experiment of coarse and then of fine ground malt and judge for himself. ART. V. _How to choose Malt._ Malt is chosen by its sweet smell, mellow taste, full flower, round body and thin skin. There are two kinds used, the pale and the brown--the pale is the best. ART. VI. _How to build a Malt kiln in every Distillery._ When setting up your stills, leave a space of about nine inches for a small furnace between the large ones, extend it to your chimney and carry up a funnel, there-from to the loft, then stop it--here build the kiln on the loft, about 4 or 5 feet square, the walls to be composed of single brick, 3 feet high--lay the bottom with brick, cover it with a plaster of mortar, to prevent the floor from taking fire. Turn the funnel of the chimney into, and extend it to the centre of the kiln, cover the top, leaving vent holes at the sides for the heat to escape thro'--Place on the top of the kiln, sheet iron or tin punched full of small holes, too small to admit the passage of malt; lay the malt on the top of the tin, when ready for drying. Put coals from under the still furnace into the small furnace leading to the kiln, which will heat the kiln and dry the malt above, by adding to or diminishing the quantity of coals, the heat may be increased or decreased, as may be found necessary. Malt for distilling ought to be dried without smoke. ART. VII. _Hops._ Give a preference to hops of a bright green colour, sweet smell, and have a gummy or clammy effect when rubbed between the hands or fingers. SECTION V. ARTICLE I. _How to order and fill the Singling still when distilling Rye._ Scrape, clean, and grease the singling still, fill her up with beer, and keep a good fire under her, till she be warm enough to head, stirring her constantly with a broom, to prevent the grain from sticking to the bottom or sides, and burning, which it is very apt to do when the beer is cold, but when it comes to boil there is little danger, prevented by the motion of boiling; have the head washed clean--when she is ready for the head, clap it on and paste it; keep up a brisk fire, until she begins to drop from the worm, then put in the damper in the chimney, and if the fire be very strong, moderate it a little, by throwing ashes or water on it, to prevent her throwing the head, which she will be very apt to do if very full, and coming round under a strong fire, (should the head come, or be thrown off, the spirit remaining will scarcely be worth running off). When fairly round and running moderately, watch her for half an hour; after which, unless the fire is very strong all danger is over. Should she happen to throw the head, it is the duty of the distiller to take and (wash the head and worm--the latter will be found full of stuff) clean, clap on the head, and paste it--but the moment the head is thrown off, the fire should be drowned out, and water thrown into the still to prevent her boiling over. It is important that after every run, or rather before you commence a run, the distiller should carefully clean out the still, wipe the bottom dry, and grease her well, to prevent her from burning and singeing the liquor. ART. II. _Mode of managing the doubling Still when making Whiskey._ Let the doubling still be carefully cleaned and washed out, then be filled with singlings and low wines left from the run preceding, add thereto half a pint of salt and one quart of clean ashes, which will help to clear the whiskey, and a handful of Indian meal to prevent the still from leaking at the cock, or elsewhere--clean the head and worm, put on the head, paste it well; put fire under and bring her round slowly, and run the spirit off as slow as possible, and preserve the water in the cooling tub as cold as in your power. Let the liquor as it runs from the worm pass thro' a flannel to prevent the overjuice from the copper, and the oil of the grain from mixing with the spirit. The first being poisonous, and the latter injurious to the liquor. The doubling still cannot be run too slow for making good whiskey ... observe when the proof leaves the worm, that is when there is no proof on the liquor as it comes from the worm, if there be ten gallons in your doubling keg, if so, run out three more, which will make in all thirteen gallons first proof whiskey. If the proof leaves the worm at eight gallons, then run till eleven gallons and so on in proportion, to the larger or smaller quantity in your keg at the time of the ceasing of the proof. ART. III. _Observations on the advantages of making strong and good Whiskey with stalement, &c._ The distiller who makes whiskey for a market under the government of inspection laws, too weak, sustains a loss of a cent for each degree it may be under proof ... and the disadvantages are increased in proportion to the extent of land carriage. If a distance of seventy miles, the price of carriage per gallon will be about six cents, paying the same price for weak or strong ... not only the disadvantage of paying for the carriage of feints or water, but the loss in the casks, which tho' small apparently at first view, yet if nicely attended to, will amount in the course of the year to a sum of moment to every distiller or proprietor. To convey my ideas, or render a more compleat exposition of my impressions as to the actual loss on one waggon load (predicated on a distance of seventy miles land carriage) of first proof whiskey, and that nine degrees under proof. I give the following statement. 300 _gallons good first proof whiskey at_ 50 _cents_, $ 150 _haling at six cents_, 18 ________ $ 132 00 300 _gallons whiskey nine degrees under proof at_ 41 _cents_, $ 123 _haling_ 18 ________ $ 105 00 ________ difference $ 27 00 This difference of twenty-seven dollars in favor of the distiller, who sends first proof whiskey, is not the only advantage, but he saves in barrels or casks, what will contain fifty four gallons, nearly two barrels; which together with the time saved, or gained in running good whiskey only, of filling and measuring it out, loading, &c. will leave an advantage of I presume, three dollars in each load. Or to verify more satisfactorily, and I hope my readers will not think me too prolix, as economy cannot be too much attended to in this business, I add a statement predicated on a year's work, and on the foregoing principles: _The distiller of weak whiskey, in twelve months, or one year, distils at the rate of_ 100 _gallons per week, or say in the year, he prepares for a market at the above distance,_ 5000 _gallons, which ought to command_ $ 2,500 _But he sustains a loss or deduction of_ 9 _cents_, 450 _Then the first loss may safely be computed at_ $ 450 150 _empty barrels necessary to contain_ 5000 _gallons, at_ 33-1/3 _gallons to the barrel, estimating the barrel at 7s and 6d, is_ $ 150 _This quantity of whiskey, when reduced to proof, is 4,100 gals. which would have occupied only 123 barrels_, 123 ------- 27 _Then the second loss may be estimated at_ $ 27 _He ought to have made this quantity of_ 4100 _gallons in nine months and three weeks, but we will say 10 months, sustaining a loss of two months in the year._ _3d item of loss. Hire of distiller for 2 months at_ $12 24 00 _4th do. Rent of distillery do. at £15 per annum._ 6 66 _5th do. One sixth of the wood consumed, (at the rate of 100 cords per annum,) 16 cords_, 20 00 _6th do. One sixth of the Malt, do. say 90 bushels_, 90 00 _7th do. Is the wear and tear of stills, vessels, &c._ 12 34 ------- $ 630 Showing hereby a total annual loss to the careless distiller, of six hundred and thirty dollars, and a weekly loss of twelve dollars and three cents in the whiskey of nine degrees below proof--our ninth part of which is seventy dollars, which is the sum of loss sustained on each degree in this quantity of whiskey. The foregoing I flatter myself will not only show the necessity of care, cleanliness, industry and judgment, in the business of distilling; a business professed to be known, by almost every body--but in reality quite a science, and so abstruse as to be but too imperfectly understood; and moreover, the value of time, so inestimable in itself, the economy of which is so rarely attended to. ART. IV. _Distilling of Buckwheat._ Buckwheat is an unprofitable grain for the distillers when distilled by itself, but when mixed with rye, it will yield nearly as much as rye; but I would by no means recommend the use of it when it can be avoided. Tho' sometimes necessity requires that a distiller should mash it for a day or two, when any thing is the matter, or that grain cannot be procured. In such event, the directions for distilling rye, or rye and corn may be followed, but it requires a much larger quantity of boiling water and if distilled by itself; it is necessary some wheat bran be mixed with it to raise it to the top of the hogshead: but by no means use buckwheat meal in making yeast. ART. V. _Distilling of Potatoes._ This is a branch of distilling that I cannot too highly recommend to the attention of every American--nor can the cultivation of this valuable vegetable be carried to a too great extent, the value of which ought to be known to every planter and it some times has awakened my surprise that they are not more cultivated, as it is notorious that they will sustain, and be a tolerable food for every thing possessing life on this earth--and as they produce a brandy, if properly made, of fine flavour. I hope yet to see the day when it will take precedence of French brandy and West-India spirits, and thereby retain in our own country, the immense sums at present expended on those foreign liquors; which, tho' benefitted by the sea voyage, yet often reaches us in a most pernicious state, and is frequently adulterated here. Could the American farmer be brought to raise a larger quantity of potatoes than necessary for his consumption at home, the price would be lowered, and the distiller might commence the distillation of them with greater propriety. That they contain a great deal and a very good spirit, I am certain, and moreover, after distillation will yield as great a quantity of good wholesome food for cattle or hogs, as rye or any other grain. If distillers could be brought to try the experiment of distilling ten or twelve bushels annually, I venture to predict that it would soon become a source of profit to themselves, encouragement to the farmer, and be of benefit to our country at large. One acre of ground, if well farmed, will produce from fifty to one hundred bushels of potatoes, but say sixty on an average. One hundred farmers each planting one acre, would yield six thousand bushels, which will yield at least two gallons of spirit to each bushel; thus, twelve thousand gallons of wholesome spirit may be produced, and with care, as good as necessary to be drank. Each farmer proceeding in this way, would have one hundred and twenty gallons spirit, as much as he may have occasion to use in the year, which would save the price of some acres of wheat or one hundred and twenty gallons rye whiskey. Each acre worked in potatoes will be in better order to receive a crop of wheat, barley, rye, or any kind of grain, than from any other culture. The farmer often receiving the advantage of a double crop, at the expense of seed and labor. They grow equally well in every soil and climate, in poor as well as rich ground--provided the thin soil be manured, and the potatoes plastered with plaster of Paris; and moreover, they are easier prepared for distilling than either apples, rye or corn, as I shall show hereafter when I come to treat of the mode of preparation; and in order to demonstrate the advantages that would arise to the farmer and distiller; I add a statement of the probable profits of ten acres of potatoes, and that of a like number of acres of rye, to shew which offers the greatest advantages. _Potatoes_ DR. _Ten acres at_ 60 _bushels is_ 600 _bushels at_ 33 _cents_ $ 198 00 _Rye._ _Ten acres of Rye, at_ 30 _bushels per acre, is_ 300 _bushels at_ 60 _cents_ $ 180 00 CR. 600 _bushels yielding_ 2 _gallons to the bushel,_ 1200 _gallons at_ 50 _cents_ 600 ----- $ 402 CR. 300 _bushels yielding_ 3 _gallons to the bushel_, 900 _gallons at_ 50 _cents_ 450 ----- $ 270 _Balance in favor of Potatoes_ $ 132 Thus a balance of one hundred and thirty two dollars would appear in favor of the yield of potatoes. I would not pretend to say that ten acres of Potatoes will not take more labor than ten acres of rye, but this far I will venture to say, that the profits arising from the sale of this brandy, will more than double pay the additional expense of raising them, besides the ground will be in much better condition to receive a crop of wheat, than the rye ground, nay, will be enriched from the crop, whilst the rye ground will be greatly impoverished. ART. VI. _Receipt to prepare Potatoes for Distilling._ Wash them clean, and grind them in an apple mill, and if there be no apple mill convenient, they may be scalded and then pounded--then put two or three bushels into a hogshead and fill the hogshead nearly full of boiling water, and stir it well for half an hour, then cover it close until the potatoes are scalded quite soft, then stir them often until they are quite cold--then put into each hogshead about two quarts of good yeast and let them ferment, which will require eight or ten days--the beer then may be drawn off and distilled, or put the pulp and all into the still, and distill them as you do apples. I have known potatoes distilled in this way to yield upwards of three gallons to the bushel. ART. VII. _Pumpions_ May be prepared by the same process used in preparing potatoes, with the exception of not scalding them so high, nor do they require so much yeast. ART. VIII. _Turnips_ Will produce nearly as much spirit as potatoes, but not so good. They must be prepared in the same manner. ART. IX. _How to distil Apples._ Apples ought to be perfectly ripe for distillation, as it has been ascertained from repeated trials, that they produce more and better spirit, (as well as cider), when fully ripe than if taken green, or the ripe and unripe mixed--if taken mixed it will not be found practicable to grind them evenly, or equally fine; those fully ripe will be well ground, whilst those hard and unripe will be little more than broken or slightly bruised--and when this coarse and fine mixture is put into a hogshead to work or ferment, that fully ripe and fine ground, will immediately begin, and will be nearly if not quite done working before the other begins, and of course nearly all the spirit contained in the unripe fruit will be lost--and if it is left standing until the ill ground unripe fruit is thoroughly fermented, and done working, you will perceive that a large portion of the spirit contained in the ripe well ground fruit is evaporated and of course lost. But if the fruit be all ripe and evenly ground, of course then it will work regularly and can be distilled in due and right order, and will produce the greatest quantity of spirit, and much superior to that produced from uneven, ill-ground or unripe fruit. Apples cannot be ground too fine. ART. X. _How to order Apples in the Hogsheads._ When the apples are ground put them into open hogsheads to ferment, taking care not to fill them too full, or they will work over; set them under cover, as the sun will sour them too soon, if permitted to operate on them, and by his heat extract a considerable quantity of the spirit, if the weather be warm they will work fast enough, provided you have a sufficient supply of hogsheads to keep your stills agoing in due time and order; about twenty hogsheads are sufficient to keep one singling still of one hundred and ten gallons agoing, if you distil the pumice with the juice, but if you press off the apples after they are done working, you must have three times that number. In warm weather five or six days is long enough for apples to work, as it is always better to distil them before they are quite done working, then to let them stand one hour after the fermentation ceases. ART. XI. _How to work Apples slow or fast._ If the hogsheads ripens too fast for your stills, add every day to each hogshead four gallons cold spring water, putting it into a hole made in the centre of the apples, with a large round stick of wood; by thus putting it into the centre of the hogshead, it will chill the fermentation, and thereby prevent the fruit from becoming ripe sooner than it may suit the convenience of the distiller. But I think it advisable that distillers should take in no more apples than they can properly manage in due time. If the weather be cold, and the apples do not ripen so fast as you wish, then add every twelve hours, four gallons boiling, or warm water, which will ripen them if the weather be not too cold in four days at farthest. ART. XII. _How to judge when Apples are ready for distilling._ Put your hand down into the hogsheads amongst the apples as far as you can, and bring out a handful of pugs--squeeze them in your hand, through your fingers, observe if there be any core, or lumps of apples un-digested, if none, you may consider them as sufficiently fermented and quite ready for distilling. It may also be ascertained by tasting and smelling the cider or juice, which rises in the hole placed in the centre; if it tastes sweet and smells strong, it is not yet ready, but when quite fermented, the taste will be sour, and smell strong, which is the proper taste for distilling. A nice discriminating attention is necessary to ascertain precisely, when the fermentation ceases, which is the proper moment for distillation, and I would recommend, rather to anticipate, than delay one hour after this period. ART. XIII. _How to fill and order the singling Still, when running Apple singlings._ When you perceive your apples ready for distilling, fill the singling still with apples and water; using about half a hogshead apples in a still of 110 gallons, the residue water, first having cleaned the still well, and greased her previous to filling--put fire under her and bring her ready to head, as quick as possible, stirring the contents well with a broom until ready to head, of which you can judge by the warmth of the apples and water, which must be rather warm to bear your hand in it any length of time. Wash the still head and worm clean, put on the head, paste it, keeping a good fire until she runs at the worm; run off 14 gallons briskly, and catch the feints in a bucket to throw into the next still full, if the singling still too fast, provided she does not smoke at the worm. When the first still full is off, and before you go to fill her the second time, draw or spread the coals that may be under her, in the furnace, and fill the furnace with wood. Shut up your furnace door and put in your damper; by proceeding thus, you cool the still and avoid burning her; this plan I deem preferable to watering out the fire. When empty, rinse the still round with cold water, scrape and grease her, then she will be ready to receive a second charge. Care is necessary in scraping and greasing your still every time she is emptied, if this is neglected, the brandy may be burnt and the still injured. ART. XIV. _How to double Apple Brandy._ Fill the doubling still with singlings, and add a quart of lime, (which will clear it) put fire under her and bring her to a run briskly--after she runs, lessen the fire and run her as slow as possible. Slow running will prevent any of the spirit from escaping, and make more and better brandy, than fast running.--Let the liquor filter thro a flannel cloth from the worm. ART. XV. _How to prepare Peaches._ Peaches like apples ought to be equally ripe, in order to insure an equal and regular fermentation--for where ripe and unripe fruit are thrown into the same hogshead, and ordered for distillation in this way a disadvantage is sustained. I therefore recommend to farmers and distillers, when picking the peaches to assort them when putting them in hogsheads, all soft ripe peaches may go together, as also those which are hard and less ripe--this will enable a more regular fermentation, and though the hard and less ripe, will take a longer time, than the soft and ripe to ferment, and yield less, yet the disadvantage will not be so great, as if mixed. They ought to be ground in a mill with metal nuts, that the stone and kernel may be well broken. The kernel when thus broken will give a finer flavor to the brandy, and increase the quantity. When they are ground they must be placed in hogsheads and worked in the same way with apples, but distilled sooner or they will lose much more spirit by standing any time after fermentation than apples. It is therefore better to distil them a short time before they are done working than at any period after. ART. XVI. _How to double and single Peach Brandy._ The same process must be observed in running off peaches as in apples, except that the singling still ought not to be run so fast, nor so much fire kept under her, and more water used to prevent burning. SECTION VI. ARTICLE I. _The best method of setting Stills._ If stills are not set right, great injury may accrue to them, in burning and damaging the sides, singeing the whiskey, and wasting of fuel too, are not the only disadvantages; but more damage may be done in six months, than would pay a man of judgment for putting up twenty pair. If they are set with their bottoms to the fire, they are very apt to burn, without the utmost care of the distiller, in stirring her when newly filled with cold beer, until she is warm, and by previously greasing the bottom well when empty. If wood be plenty, stills ought to be set on an arch, but if scarce, the bottom ought to be set to the fire. The following method is calculated for a furnace of either two or four feet long, and with the bottoms exposed, or on an arch as the distiller may fancy. Make up a quantity of well worked mortar, composed of the greater proportion of good clay, a little lime and cut straw. Lay the bottom of the furnace with flag stones, or good brick, from two to four feet long, as may be deemed most proper, let it be from twelve to sixteen inches wide, and from twelve to fourteen high. Then if it is designed to turn an arch, set the end of a brick on each wall of the furnace, leaning them over the furnace, till they meet in the middle--so continue the range on each side, until the furnace is completely covered in, leaving a small hole for the flue leading to the chimney behind, leaning towards the side, from which the flue is to be started, to proceed round the bilge of the still, which passage must be ten by four inches wide. After completing the arch as described, lay thereon a complete bed of mortar, well mixed with cut straw, set the still thereon, levelling her so that she will nearly empty her self by the stoop towards the cock; then fill up all round her with mortar to the lower rivets, carefully preventing any stone or brick from touching her, (as they would tend to burn her) ... then build the fender or fenders; being a wall composed of brickbats and clay well mixed with cut straw, build it from the commencement of the flue, and continue it about half round the still ... this is to prevent the flames from striking the still sides, in its hot state, immediately after it leaves the furnace, presuming that it will terminate before it reaches the end of this little wall or fender, between which, and the still, a space of two inches ought to be left for the action of the heat, which space preserves, and prevents the wall or fender, from burning the still; the mode in common practice, being to place it against the still, which will certainly singe or burn her. When this defender is finished, commence a wall, which continue round, laying a brick for a foundation, about four inches from the lower rivets; thus raising this wall for the flue, continuing it at an equal distance from the still, leaving a concave to correspond with the bilge of the still, and to be of precisely the same width and height all round the still. This precaution is absolutely necessary in building the wall of the flue exactly to correspond with the form of the still, and equally distant all round, for reasons 1st. The fire acts with equal force on every part of the still, and a greater heat may be applied to her, without burning. 2d. It has a great tendency to prevent the still house from smoking. When the wall of the flue is completed round the still, and raised so high, that a brick when laid on the top of the wall will extend to the rivets in the breast of the still or upper rivets, then completely plaster very smooth and even, the inside of the flue, and then cover the flue with a layer of brick, with a slight fall, or leaning a little from the still outwards, so that if water were dropped thereon, it would run off outwardly, carefully laying a layer of clay on the top of the wall, on which the brick may rest, and thereby prevent the brick from burning the still; carefully forming the brick with the trowel, so as to fit the wall and rest more safely--cautiously covering them well with clay, &c. and closing every crevice or aperture, to prevent smoak from coming thro' or the heat from deserting the flue till it passes to the chimney from the flue; then fill the still with water, and put a flow fire under her to dry the work. When the wall begins to dry, lay on a coat of mortar, (such as the next receipt directs), about two inches thick, when this begins to dry, lay a white coat of lime and sand-mortar, smoothing well with a trowel; rubbing it constantly and pressing it severely with the trowel to prevent it from cracking. There are many modes of setting stills and bringing the fire up by flues variously constructed, but I have found the foregoing plan to afford as great a saving of fuel, and bringing the still to a boil as early as any other. ART. II. _How to prevent the Plastering round Stills from cracking._ This method of making water proof plastering on stills, is done entirely in making the mortar, and putting it on, in making which, good clay and lime are absolutely necessary. When the mortar for the first coat is thoroughly worked, put as much brock of rye straw into it, as can be worked in, so that when the coat is put on, it may have a greater appearance of straw than mortar, when dry, and covered with the second coat composed of lime mortar, well rubbed and pressed with the trowel until it be dry. A covering put on of those materials, will be found to continue firm and compact without cracking, as in the common mode. _The best method of boiling two, three or more Stills or Kettles with one fire or furnace._ This method has been found to answer in some instances, and may perhaps do generally if properly managed. I will here give the result of my own experiments. I set a singling still holding 180 gallons on a furnace of 18 by 14 inches, and 4 feet six inches long, with the bottom to the fire, she had a common head and worm with scrapers and chains in her. I extended the flue, (or after passing it round her), to the doubling still which it likewise went round--but to prevent too much heat from passing to the doubling still, I fixed a shutter in the flue of the singling still, immediately above the intersection of the flue of the doubling still, to turn all the heat round her, and another shutter in the flue of the doubling still at the intersection of the flue of the singling still, to shut the heat off from the doubling still if necessary. With this fixture I run six hogsheads off in every twenty four hours and doubled the same, with the same heat and fire. I likewise had a boiler under which I kept another fire, which two fires consumed about three cords and an half of wood per week, distilling at the rate of sixty-five bushels of grain per week, and making about one hundred and ninety gallons in the same time. Before I adopted this method I kept four fires agoing, and made about the same quantity of whiskey, consuming about four and an half cords of wood per week, and was obliged to have the assistance of an additional distiller per week. I have since heard of the adoption of this plan with more success than I experienced. ART. III. _To set a doubling Still._ As spirits can hardly be burned or singed in a doubling still, if not before done in singling, all the precaution necessary is to set them in the best method for saving fuel, and preserving the still. The instructions given for setting a singling still, is presumed to be adequate to setting a doubling still. _How to prevent the singling Still from burning._ If the singling still be well set, and is carefully greased with a piece of bacon, tallow or hard soap, every time she is filled, she will seldom burn, but if she does burn or singe notwithstanding these precautions, it will be advisable to take her down and set her up a new ten times, rather than have her burned. SECTION VII. ARTICLE I. _How to clarify Whiskey, &c._ Take any vessel of convenient size, take one end out and make it clean, by scalding or otherwise; bore the bottom full of holes, a quarter of an inch in diameter--lay thereon three folds of flannel, over which spread ground maple charcoal and burnt brick-dust, made to the consistence of mortar, with whiskey, about two inches thick, pour your whiskey or brandy thereon, and let it filter thro' the charcoal, flannel, &c. after which you will find the spirit to have scarcely any taste or smell of whiskey.--Elevate the filtering cask so as to leave room to place a vessel to receive the spirit under it. ART. II. _How to make a Brandy resembling French Brandy, from Rye Whiskey or Apple Brandy._ Clarify the whiskey as the above receipt directs, after thus purifying, add one third or one fourth of French brandy, and it will be then found strongly to resemble the French brandy in taste and smell--and if kept a few years, will be found more salutary and healthful than French brandy alone. This mode of clarifying rids the spirit of any unpleasant flavour received in the process of distillation or from bad materials, and moreover, from all those vicious, poisonous properties contracted in the still or worm from copper; such as foetid oil from the malt, which frequently unites with the verdigris, and combines so effectually with whiskey, that it may possible require a frequent repetition of this mode of clarifying, to rid it completely of any unpleasant taste or property contracted as above stated. ART. III. _How to make a Spirit resemble Jamaica Spirit out of Rye Whiskey._ This is done precisely in the manner laid down in the receipt for French brandy. ART. IV. _How to make a resemblance of Holland Gin out of Rye Whiskey._ Put clarified whiskey, with an equal quantity of water, into your doubling still, together with a sufficient quantity of juniper berries, prepared; take a pound of unflacked lime, immerse it in three pints of water, stir it well--then let it stand three hours, until the lime sinks to the bottom, then pour off the clear lime water, with which boil half an ounce of isinglass cut small, until the latter is dissolved--then pour it into your doubling still with a handful of hops, and a handful of common salt, put on the head and set her a running; when she begins to run, take the first half gallon (which is not so good), and reserve it for the next still you fill--as the first shot generally contains something that will give an unpleasant taste and colour to the gin. When it looses proof at the worm, take the keg away that contains the gin, and bring it down to a proper strength with rain water, which must previously have been prepared, by having been evaporated and condensed in the doubling still and cooling tub. This gin when fined, and two years old, will be equal, if not superior to Holland gin. The isinglass, lime water and salt, helps to refine it in the still, and the juniper berries gives the flavor or taste of Holland gin. About thirteen pounds of good berries, are sufficient for one barrel. Be careful to let the gin as it runs from the worm, pass thro' a flannel cloth, which will prevent many unpleasant particles from passing into the liquor, which are contracted in the condensation, and the overjuice imbibed in its passage thro' the worm. ART. V. _The best method of making common country Gin._ Take of singlings a sufficient quantity to fill the doubling still, put therein ten or twelve pounds of juniper berries, with one shovel full of ashes, and two ounces alum--put on the bead, and run her off, as is done in making whiskey. This is the common mode of making country gin; but is in this state little superior to whiskey, save as to smell and flavor. It is therefore in my mind, that the mode of clarifying, prescribed, ought to be pursued in all distilleries, so far as necessary to make a sufficient quantity of good spirit for any market convenient--the supply of respectable neighbors, who may prefer giving a trifle more per gallon, than for common stuff and for domestic use. And moreover, I think the distiller will meet a generous price for such clarified, and pure spirit, as he may send to a large mercantile town for sale--as brewers and others, frequently desire such for mixing, brewing, making brandies in the French and Spanish mode, and spirits after the Jamaica custom. And after the establishment of a filtering tub or hopper, prepared as before described, with holes, flannel or woollen cloth, and plenty of maple charcoal, and burnt brick-dust, a distiller may always find leisure to attend to the filtration; indeed it will be found as simple and easy, as the process for making ley from ashes in the country for soap. But I would suggest that spirit prepared and clarified in this way, should be put into the sweetest and perfectly pure casks. New barrels will most certainly impart color, and perhaps some taste, which would injure the sale, if intended for a commercial town market, and for brewing, or mixing with spirits, from which it is to receive its flavor. For my own use, I would put this spirit into a nice sweet cask, and to each barrel I would add a pint of regularly, and well browned wheat, not burned but roasted as much as coffee. The taste of peach brandy may be imparted to it by a quantity of peach stone kernels, dried, pounded and stirred into the cask; in this way, those who are fond of the peach brandy flavor, may drink it without becoming subject to the pernicious consequences that arise from the constant use of peach brandy. Peach brandy, unless cleansed of its gross and cloying properties, or is suffered to acquire some years of age, has a cloying effect on the stomach, which it vitiates, by destroying the effect of the salival and gastric juices, which have an effect on aliment, similar to that of yeast on bread, and by its singular properties prevents those juices from the performance of their usual functions in the fermentation of the food taken into the stomach--producing acid and acrimonious matter, which in warm climates generates fevers and agues. Apple brandy has not quite a similar but equally pernicious effect, which age generally removes--indeed, age renders it a very fine liquor, and when diluted with water, makes a very happy beverage, gives life and animation to the digesting powers, and rarely leaves the stomach heavy, languid and cloyed. Then both those, (indeed, all liquors,) ought to be avoided when new, by persons of delicate habit, and those who do not exercise freely. A severe exercise and rough life, generally enables the stomach to digest the most coarse food, by liquor, however new. _On fining Liquors._ Isinglass is almost universally used in fining liquors. Take about half an ounce to the barrel--beat it fine with a hammer, lay it in a convenient vessel, pour thereon two gallons whiskey, or a like quantity of the liquor you are about to fine, let it soak two or three days, or till it becomes soft enough to mix--then stir it effectually, and add the white and shells of half a dozen eggs--beat them up together and pour them into the cask that is to be fined, then stir it in the cask, bung it slightly, after standing three or four days it will be sufficiently fine, and may be drawn off into a clean cask. ART. VI. _On colouring Liquors._ One pound of brown sugar burnt in a skillet almost to a cinder, add a quart of water, which when stirred, will dissolve the sugar--when dissolved, this quantity will color three barrels. A pint of well parched wheat put into a barrel will colour it, and give more the appearance of a naturally acquired colour, and an aged taste or flavor. ART. VII. _To correct the taste of singed Whiskey._ Altho' this cannot be done effectually without clarifying, as prescribed, but Bohea tea will in a great measure correct a slight singe--a quarter of a pound may be tried to the barrel. ART. VIII. _To give an aged flavor to Whiskey._ This process ought to be attended to by every distiller, and with all whiskey, and if carefully done, would raise the character, and add to the wholesomeness of domestic spirits. It may be done by clarifying the singlings as it runs from the still--let the funnel be a little broader than usual, cover it with two or more layers of flannel, on which place a quantity of finely beaten maple charcoal, thro' which let the singlings filter into your usual receiving cask. When doubling, put some lime and charcoal in the still, and run the liquor thro' a flannel--when it loses proof at the worm, take away the cask, and bring it to proof with rain water that has been distilled. To each hogshead of whiskey, use a pound of Bohea tea, and set it in the sun for two weeks or more, then remove it to a cool cellar, and when cold it will have the taste and flavor of old whiskey. If this method was pursued by distillers and spirits made 2d and 3d proof, it would not only benefit the seller, but would be an advantage to the buyer and consumer--and was any particular distiller to pursue this mode and brand his casks, it would raise the character of his liquor, and give it such an ascendancy as to preclude the sale of any other, beyond what scarcity or an emergency might impel in a commercial city. If distillers could conveniently place their liquor in a high loft, and suffer it to fall to the cellar by a pipe, it would be greatly improved by the friction and ebullition occasioned in the descent and fall. SECTION VIII. ARTICLE I. _Observations on Weather._ Some seasons are better for fermentation than others. Should a hail storm occur in the summer, the distiller should guard against cooling off with water in which hail is dissolved, for it will not work well. If a thundergust happens when the hogsheads are in the highest state of fermentation, the working will nearly cease, and the stuff begin to contract an acidity. And when in the spring the frost is coming out of the ground, it is unfortunate when the distiller is obliged to use water impregnated with the fusions of the frost, such being very injurious to fermentation--Those changes and occurrences ought to be marked well, to enable a provision against their effects. This will be found difficult without the assistance of a barometer, to determine the changes of the weather--a thermometer, to ascertain correctly the heat of the atmosphere, and to enable a medium and temperature of the air to be kept up in the distillery; and from observation to acquire a knowledge of the degree of heat or warmth, in which the mashing in the hogsheads ferments to the greatest advantage, and when this is ascertained, a distiller may in a close house sufficiently ventilated, and provided with convenient windows, always keep up the degree or temperature in the air, most adapted to the promotion of fermentation, by opening his windows or doors to admit air, as a corrective; or by keeping them closed in proportion to the coldness of the weather:--And a hydrometer, useful in measuring and ascertaining the extent of water. Instructions for the management of those instruments generally attend them, it is therefore unnecessary for me to go into a detail on this subject.--But it is absolutely necessary that the careful and scientific distiller should possess them, especially the two former, to guard against the changes of the weather, and preserve the atmosphere in the distillery, always equally warm. ART. II. _Observations on Water._ Distillers cannot be too particular in selecting good water for distilling, when about to erect distilleries. Any water will do for the use of the condensing tubs or coolers, but there are many kinds of water that will not answer the purpose of mashing or fermenting to advantage; among which are snow and limestone water, either of which possess such properties, as to require one fifth more of grain to yield the same quantity of liquor, that would be produced while using river water. Any water will answer the distillers purpose, that will dissolve soap, or will wash well with soap, or make a good lather for shaving. River or creek water is the best for distilling except when mixed with snow or land water from clay or ploughed ground. If no river or creek water can be procured, that from a pond, supplied by a spring, if the bottom be not very muddy will do, as the exposure to the sun, will generally have corrected those properties inimical to fermentation. Very hard water drawn from a deep well, and thrown into a cistern, or reservoir and exposed to the sun and air for two or three days, has been used in mashing with success, with a small addition of chop grain or malt. I consider rain water as next in order to that from the river, for mashing and fermentation. Mountain, slate, gravel and running water, are all preferable to limestone, unless impregnated with minerals--many of which are utterly at variance with fermentation. With few exceptions, I have found limestone, and all spring water too hard for mashing, scalding or fermenting. ART. III. _Precautions against Fire_ Cannot be too closely attended to. The store house, or cellar for keeping whiskey in, ought to be some distance from the distillery, and the liquor deposited, and all work necessary in it done by day, to avoid all possible danger arising from candles or lamps, from which many serious calamities have occurred. Suppose the cellar or place of deposit to be entered at night by a person carrying a lamp or candle, and a leaking cask takes his attention, in correcting the leak, he may set his lamp on the ground covered with whiskey, or he may drop by chance one drop of burning oil on a small stream of whiskey, which will communicate like gun powder, and may cause an explosion, which may in all likelihood destroy the stock on hand, the house, and the life of the individual.--On this subject it is not necessary I should say much, as every individual employed about a distillery must have some knowledge of the value of life and property. SECTION IX. ARTICLE I. _The duty of the owner of a Distillery._ The main and first object of the proprietor of a distillery, is gain or profit--and the second, it is natural, should be the acquiring a character or reputation for his liquor, and a desire to excel neighboring distilleries--in both of which, neglect and sloth will insure disappointment. The active, cleanly, industrious and attentive proprietor uses the following means. First. He provides his distillery with good sound grain, hogsheads, barrels, kegs, funnels, brooms, malt, hops, wood, &c. of all of which he has in plenty, nicely handled, and in good order. He also provides an hydrometer, thermometer, and particularly a barometer, duly observing the instructions accompanying each, their utility and particular uses. Secondly. He is careful that his distiller does his duty, of which he can be assured only, by rising at four o'clock, winter and summer, to see if the distiller is up and at his business, and that every thing is going well--and to prepare every thing and article necessary--to attend and see the hogs fed, and that the potale or slop be cold when given, and that the cattle be slopped--that the stills are not burning, nor the casks leaking, &c. &c. He observes the barometer, points out any changes in the weather, and pays an unremitted attention, seeing that all things are in perfect order, and enforcing any changes he may deem necessary. On the other hand, indolence begets indolence--The proprietor who sleeps till after sun rise, sets an example to his distiller and people, which is too often followed--the distillery becomes cold from the want of a regular fire being kept up in her--the hogsheads cease to work or ferment, of consequence, they will not turn out so much whiskey--and there is a general injury sustained. And it may often occur, that during one, two or three days in the week, the distiller may want grain, wood, malt, hops or some necessary--and perhaps all those things may be wanting during the same day ... and of course, the distiller stands idle. The cattle, hogs, &c. suffer; and from this irregular mode of managing, I have known the proprietor to sink money, sink in reputation, and rarely ever to attribute the effect to the right cause. _System and Method._ A well timed observance of system and method are necessary in all the various branches of business pursued, and without which none succeeds so well. And whilst the industrious, attentive and cleanly proprietor, may with certainty, calculate on a handsome profit and certain advantages to result from this business. He who conducts carelessly, may as certainly reckon on sustaining a general loss. ART. II. _The duty of an hired Distiller_ Is to rise at four o'clock every morning. Wash and clean out the boiler, fill her up with clean water, put fire under her, and to clean, fill and put fire under the singling still--to collect and put in order for mashing, his hogsheads--and as soon as the water is warm enough in the boiler to begin mashing, which he ought to finish as early in the day as possible; for when the mashing is done, he will have time to scald and clean his vessels, to attend his doubling and singling still, to get in wood for next day, and to make his stock yeast, if new yeast is wanting. In short, the distiller ought to have his mashing finished by twelve o'clock every day, to see and have every thing in the still house, under his eye at the same time; but he ought never to attempt doing more than one thing at once--a distiller ought never to be in a hurry, but always busy. I have always remarked that the bustling unsteady distiller attempts doing two or three things at once, and rarely ever has his business in the same state of forwardness with the steady methodical character. SECTION X. ARTICLE I. _Profits of a Common Distillery._ Profits arising from a distillery with two common stills, one containing 110 gallons, and one containing 65 gallons that is well conducted for 10 months. The calculations predicated on a site, distant about 60 miles from market. Due regard is paid to the rising and falling markets in the following statement. The selling price of whiskey will always regulate the price of grain, the distiller's wages, the prices of malt, hops, hauling, &c. is rather above than below par. _Distillery, Dr._ To 1077 bushels corn, at 50 cents per bushel, is $ 538 50 533 bushels rye, at 60 cents 309 80 96 bushels malt, at 70 ditto 67 20 ______ 1706 bushels total. 60 pounds hops at 25 cents per pound 15 100 cords of wood, at 2 dollars 200 Distiller's wages per year and boarding 204 70 Hauling whiskey, at 4 cents per gallon 204 70 50 poor hogs at 4 dollars each 200 --------- $ 1739 90 _Contra Cr._ By 5118 gallons whiskey, at 59 cents per gallon $ 2559 50 fat hogs at 7 dollars each 350 --------- $ 2939 --------- Leaving a balance of $ 1143 10 I have charged nothing for hauling of grain, &c. as the feed or slop for milk cows, young cattle, and fatting cattle, will more than pay that expense. An estimate of the profits arising from a patent distillery, (col. Anderson's patent improved) 1 still of 110 with a patent head, 1 still of 85 gallons for a doubling still, and a boiler of metal, holding 110 gallons. _Distillery, Dr._ To 2454 bushels corn, at 50 cents per bushel $ 1227 1216 do. rye, at 60 cents do. 729 60 200 do. malt at 70 cents do. 140 --------- 3870 120 pounds hops, at 25 cents per pound 30 100 cords wood, at 2 dollars per cord 200 2 distillers wages, boarding, &c. 400 Hauling whiskey, per gallon at 4 cents 464 40 120 poor hogs at 4 dolls. each 480 ________ Total expense $ 3671 _Contra, Cr._ By 11610 gallons whiskey, at 50 cents per gallon $ 5805 50 120 fat hogs, at 7 dolls. each 840 _________ $ 6645 50 _________ Clear profit, $ 2974 50 Profit of a common distillery 1148 10 _________ Balance in favor of a patent distillery $ 1826 40 _________ To do the business of a patent distillery or to carry her on to advantage, requires a little more capital to start with--but either the patent or common distillery, when they have run two or three months, managed by an attentive and brisk dealing man, will maintain, or keep themselves agoing. Where wood is scarce and money plenty, the patent distillery is certainly to be recommended, indeed, in all cases, I would recommend it, where the proprietor has money enough. It is by far the most profitable, and will sooner or later become in general use in this country. ART. III. _Of Hogs._ Raising, feeding and fattening hogs on potale, a business pursued and highly spoken of, but from my experience I have discovered that few good pigs can be raised entirely on potale--as it has a tendency to gripe and scour too much; but after they are weaned and a little used with slop, they will thrive well. If a hog in a cold morning comes running to a trough full of slop, that is almost boiling, and is very hungry--their nature is so gluttonous & voracious, that it will take several mouthfuls before it feels the effects of the heat, and endangers the scalding of the mouth, throat and entrails--and which may be followed by mortification and death;--moreover, hot feeding is the cause of so many deaths, and ill-looking unhealthy pigs, about some distilleries--which inconvenience might be avoided by taking care to feed or fill the troughs before the boiling slop is let out from the still. A distiller cannot be too careful of his hogs--as with care, they will be found the most productive stock he can raise--and without care unproductive. The offals of distilleries and mills cannot be more advantageously appropriated than in raising of hogs--they are prolific, arrive at maturity in a short period, always in demand. Pork generally sells for more than beef, and the lard commands a higher price than tallow; of the value of pork and every part of this animal, it is unnecessary for me to enter into detail; of their great value and utility, almost every person is well acquainted. The hog pens and troughs ought to be kept clean and in good order, the still slop salted two or three times a week; when fattening, hogs should be kept in a close pen, and in the summer a place provided to wallow in water. Hogs that are fed on potale, ought not to lie out at night, as dew, rain and snow injures them--indeed such is their aversion to bad weather, that when it comes on, or only a heavy shower of rain, away they run, full speed, each endeavoring to be foremost, all continually crying out, until they reach their stye or place of shelter. At the age of nine months, this animal copulates first, and frequently earlier, but it is better engendering should be prevented, till the age of eighteen months--for at an earlier age, the litter is uniformly small, and weakly, and frequently do not survive, besides the growth is injured. It is therefore better not to turn a sow to breeding, till from 18 to 24 months old. The sow goes four months with pig, and yields her litter at the commencement of the fifth; soon after encourages and receives the boar, and thus produces two litters in the year. I have known an instance of three litters having been produced in the year from one female. A sow ought not to be permitted to suckle her pigs more than two or three weeks, after which eight or nine only should be left with her, the rest sold, or sent to market, or killed for use--at the age of three weeks they are fit for eating, if the sow is well fed. A few sows will serve, and those kept for breeding, well selected from the litter, the residue, cut and splayed. Care and pains is due in the choice of the breed of hogs--the breeder had then better procure good ones, and of a good race at once, tho' the expense and trouble may seem material in the outset, yet the keeping will be the same, and the produce perhaps fifty per cent more. After the pigs are weaned, they ought to be fed for the first two weeks on milk, water and bran, after which potale may be used in the room of milk. I would recommend a little mixed potale from an early period, and increase it, so as to render them accustomed to the slop gradually. ART. IV. _Of the Diseases of Hogs._ The only disease that I know of which seems to be peculiar to hogs, is a kind of leprosy, commonly called measles, when it seizes them, they become dull and sleepy, if the tongue is pulled out, the palate and throat will be found full of blackish spots, which appear also on the head, neck, and on the whole body--the creature is scarce able to stand, and the roots of its bristles are bloody. As this disorder proceeds chiefly from their gluttony and filth, and hot drinking of potale and slop; to remedy which, it would be commendable to feed on cold potale, or scarcely milk warm, to keep them clean, to mix salt occasionally with the potale--tar their trough once a month, and give them a little ground antimony. In fattening hogs I have known them improve rapidly, after eating the warm ashes from a fresh burned brush heap. Hickory or willow ashes will have an effect to destroy worms, and I think ought to be used, they will eat it dry, when put in their troughs. ART. V. _On feeding Cattle and Milch Cows._ Potale is a great creator of milk, and will increase the quantity greatly in cows yielding milk, but no so good. Young cattle thrive very well, that get hay or straw during the night. To fatten cattle there ought to be mixed with the slop, a little oil meal, or chopped flaxseed, or chopped corn. The cattle kept on still slop ought to get plenty of salt. Warm potale injures their teeth. SECTION XI. ARTICLE I. _Observations on erecting Distilleries._ Those who are about to erect distilleries, have a handsome subject for consideration; the advantages, and the probable disadvantages that may arise from building on a particular site, or seat. The contiguity to a chopping mill is a material consideration--Wood forming an important article, should be taken into view--Grain merits also a great share of attention. The water which forms, by no means, the least important ingredient should be well analyzed; and a share of thought is due to the subject of a market for the whiskey, spirits and pork, produced from the establishment.--And should the water then prove good, soft and proper for fermentation, can be bro't over head, and the chopping mill is not very inconvenient, and wood convenient and cheap, and grain plenty and at reasonable prices, and a market within one hundred miles, I have little doubt but that with proper economy and observance of system, the establishment will prove very productive; and may be progressed in with cheerfulness, and a reasonable hope of a fair retribution to the owner. A proper seat being fixed on, with sufficient fall to bring the water over head, for it is very material, and an immense saving of labor--material, because it prevents a loss, in running the stills, from pumping or want of water in the cooling tubs. The size of the house follows, as requiring some more than usual calculation--houses are generally made too small, giving great inconvenience, and preventing that nice attention to cleanliness, which forms a very important item in the process of distilling. I would recommend a size sufficiently large for three stills, and to mash six hogsheads per day--one of col. Anderson's patent improved stills, I would consider, in many situations, as most desirable; at all events, I would recommend the preparation of room enough for three stills, if even it should be the intention of the owner to erect but two--for it is very probable, that after some experience, he may determine to pursue the business more extensively, and add the patent still. The size then established, I would recommend the lower story to be 10 feet high, this will leave room for the heated, or rarefied air to ascend in the summer above the cooler, and more necessary air in the warm season of the year, and prevent the unpleasant effect of a too warm air on the mashing hogsheads, and the sowing of the stuff in fermentation--and moreover, prevent the unpleasant effects of smoak on the distillers eyes. But it is important that the house should be erected on level ground with doors opposite each other, with plenty of windows to afford a draft and recourse of air, at pleasure, during the warm season; and so that in the winter it may be closed and preserved perfectly warm--to which end it is most expedient the lower story should be well built with stone and lime, and neatly plastered--the windows well glazed, with shutters &c. Thus provided, and a thermometer placed in the centre of the house, a proper temperature may be kept up in the air of the house--for there is a certain degree of warmth which exceeds for fermentation--this degree of heat, then correctly ascertained by the distiller, he may by a close attention to his duties, fires and the thermometer, always keep the air of the house in nearly that same and most approved state; and even by a well timed observation guard against storms and casualties. To effectuate this grand and important object, some have divided the stills, placing the boiler at one end, and a singling and doubling still at the other; this mode will ensure, in cold weather, the success of the measure more fully--others have placed all the stills in the centre of the building--a plan that will do better in the winter than in the summer, and one I think less favourably of than that of dividing them. During the winter, the north or northwest side of the house should be kept quite close, permitting the house to be lighted from the more temperate southward exposure. To calculate the window sashes to open by hinges, or to be taken entirely out in the summer, at pleasure, is in my mind advisable. SECTION XII. ARTICLE I. _On Wines._ Presuming this work may be rendered more desirable to farmers, from the introduction of some receipts for making domestic wine from the common hedge grapes, or such as are common on fence rows and on high rich grounds, and which are pleasantly flavored after receiving frost, and also for making cider in the best mode for preservation. I have extracted a few from various author's. _Receipt for making Domestic Wine from the Autumn Blue Grape._ About the latter end of September or about the first white frosts, gather the grapes which with us grow along old fences and hedges--pick all the grapes from the stems that are juicy, allowing two bushels thus picked a little heaped, to the barrel. Mash them well between your hands in small parcels, either in earthen pans, or some convenient small vessels--put them when mashed into a tub together, and add a little water so as to soak the pumice.... After stirring them well together, squeeze the pumice out from the liquor with your hands, as clean as you can--then strain the juice through a hair sieve. If the juice seems not all extracted from the pumice at one soaking and squeezing, put water to the pumice and squeeze them over again; take care not to add too much water, lest there should be more than the cask will hold. If after all the ingredients are added, the cask is not full, it may then be filled up with water. To the liquor thus prepared, add two pounds of good, clean, rich low priced brown sugar, per gallon, stirring it in the tub till all the sugar be dissolved; let it remain in the tub, and in a day or two it will ferment, and the scum rise to the top, which must be carefully skimmed off--then put the wine into a clean nice barrel--do not bung it up tight. There is generally a fermentation in it the spring following, when the grape vines are in blossom, but racking it off just before that season will prevent its working too much. If it is wanted to be soon ripe for use, put a quart of good old brandy after it is racked off, to the barrel, and give it air by leaving the bung quite loose. This mode of manufacturing wine for domestic use, is convenient and not expensive to those who have it in their power to manufacture maple sugar. But the nice housewife or husbandmen of ingenuity, will, I fancy, devise some more neat mode of compressing the juice from the grape--as pressing it by the hand, would seem less cleanly, though the fermentation generally cleanses sufficiently. _Currant Wine_ Is managed in the same way. The same quantity of sugar is presumed to answer--The juice is generally well strained thro' cloths, and when well stirred, &c. with the sugar, and neatly racked off, is put by in a loft to ripen, in sweet casks. ART. II. _Directions for making Cider, British mode._ The apples after being thrown into a heap should always be covered from the weather. The later the cider is made the better, as the juice is then more perfectly ripened, and less danger to be feared from fermentation. Nothing does more harm to cider than a mixture of rotten apples with the sound. The apples ought to be ground so close as to break the seeds which gives the liquor an agreeable bitter. The pumice should be pressed through hair bags, and the juice strained through two sieves, the uppermost of hair, the lower of muslin. After this the cider should be put into open casks, when great attention is necessary to discover the exact time in which the pumice still remaining in the juice, rises on the top, which happens from the third to the tenth day, according as the weather is more or less warm. This body does not remain on top more than two hours; consequently, care should be taken to draw off the cider before it sinks, which may be done by means of a plug. When drawn off, the cider is put into casks. Particular attention is again required to prevent the fermentation, when the least inclination towards it is discovered. This may be done by a small quantity of cider spirits, about one gallon to the hogshead. In March the cider should be again drawn off, when all risque of fermentation ceases. Then it should be put into good sweet casks, and in three years from that time, it will be fit for bottling. Old wine casks are to be preferred; those which contain rum are ruinous to cider. Large earthen vessels might be made with or without glazing, which would be preferable to any wooden vessel whatever. When we compare this with the hasty American mode of making cider, it is not to be wondered at that the English cider so infinitely excels ours. ART. III. _The following is a very highly approved American mode of making Cider._ Take care to have every necessary utensil to be made use of in the whole process, perfectly clean and free from every foreign smell. For this purpose, before you begin your work, let your mill, trough and press be made perfectly clean, by thoroughly washing, and if necessary, with scalding water. The casks are another material object, and if musty, or any other bad smell, one end should be taken out, and with shavings burn the inside; then scrub them clean, and put in the head, scald them well afterwards, and drain them perfectly; when dry, bung them tight and keep them in a cool shady place until wanted for use.--The apples should be quite ripe, and all the unripe and rotten ones, leaves, and every other thing that can tend to give the cider any disagreeable taste, carefully separated from them. I have found from careful attention and many experiments, that it is a great advantage to the cider to be separated from the gross parts as soon as possible; for this purpose, I tried several methods: that which I found succeeded the best, I shall now relate, as by following it, I was able to preserve my cider in a sound state, though made in the early part of the season. I took a large pipe, of about 150 gallons, had one of the heads taken out, and on the inside of the other laid on edge, four strips of boards, two inches wide, and on these strips placed a false bottom, filled with gimlet holes, three inches a part. On this false bottom, I put a hair cloth, (old blanket or swingline tow will do) so as to prevent any sand from washing into the space between the true and false bottoms; I procured a quantity of coarse sand, which was carefully washed in repeated waters, until it would not discolor the clean water--then dried the sand, put it in the pipe, on the hair cloth, (coarse blanket or swingline tow,) about 9 inches thick. Thus having every thing in readiness, I went through the process of making, as quick as possible, by having the apples ground fine early in the morning, putting them in the press as fast as they were ground; and then in sufficient quantities pressed out the juice, and put it over the sand in the cask, (having previously bored a gimlet hole in the side of the cask), between the true and false bottoms, in which I introduced a large goose-quill, stopped with another. The pipe was placed so high, as to admit of a cask under it, to receive the liquor as it ran from the quill, which, if rightly managed, will be perfectly fine, and being put away in a cool cellar, and stopped close, will keep well, and prove of an excellent quality. This process is easy, and in every person's power to execute, as the liquor, by being cleared, from its gross feculences, will not run into that violent fermentation, so destructive to the fine vinous flavor, which renders good cider so pleasing a drink. _Query._ Would not a quart of good apple brandy to each barrel of cider, made in this way, prevent any fermentation? But it is generally believed that cider is the better for having undergone a fermentation, becoming then more active and light; cider that has undergone condensation, or has been boiled down until strong, has been found to keep sound some length of time, but it is too heavy and destructive to the appetite, cloying the digesting powers.--And by too frequent use, I fancy, will ultimately produce ague and fevers; and I fear, cider made according to the foregoing receipt, would have a similar effect, but in a lesser degree. I would recommend after a due attention to cleanliness, in the apple mill, trough, press and casks, that the apples be assorted, and having been exposed to the air, under a roof or shed some time, selecting the sound only, that they be ground fine, and let stand soaking in the pumice twelve hours, and then pressed off, through a clean rye straw cheese (being the most common and convenient in the country,) and when flowing from the press, a vessel should be provided, with the bottom full of gimlet holes, in the style of a riddle, on which lay a coarse cloth, then a layer of clean sand, over which a parcel of coarse rye straw, and suffer it to filter thro' this vessel into the large receiving tub; the rye straw will intercept the coarser pieces of pumice, and may be changed frequently--This mode will rid the liquor of all the coarser pieces of pumice--then I would recommend that the cider should be placed in open hogsheads, such as are used for mashing grain in distilleries; those being raised about two feet and an half high on logs or a scaffolding, under a shade or covering--a spile hole bored near the bottom of each, so as to admit a barrel to stand under the spile--in this state, I would recommend it to stand until it undergoes a fermentation, carefully watching the top, and when the pumice is found to have risen, to skim it off carefully, then having previously provided sweet barrels, draw it off by the spile hole, adding from a pint to a quart of apple brandy to each barrel of strong cider, bung it up tight, and store it where the frost will not injure it. In this way, I presume it will keep well--and if the party be so disposed, I would recommend any bottling to be done in April, and during clear weather, though it is safe to bottle immediately after having undergone a thorough fermentation. _The following Receipt to make an excellent American Wine,_ Was communicated to the Burlington Society for promoting domestic manufactures, by Joseph Cooper, Esq. of Gloucester county, state of New Jersey, and ordered to be published;--which, from its extreme simplicity, and economy, shewing the convenience with which a very pleasant, healthful beverage, may be kept by every family in our country, is published in this work. And moreover, as it may have, in some degree, the happy effects of correcting the baneful and pernicious effects of coffee, which is so commonly used for breakfast in our state at present. Coffee, when first introduced, was used as a medicine only, and given only in a well clarified state, and sparingly--both from its soothing and pleasant effect, it become common, and now it is almost the only beverage used at breakfast by the farmers of Pennsylvania, and indeed, people suppose the morning repast is not genteel, unless the board is decorated with this foreign beverage. If it was used in a moderately strong well clarified state, it would be less injurious, but it is too frequently set down in a non descript state, difficult to be named, mixed with the grounds, and so far from clear, as to be entitled to the epithet of muddy, and sweetened with bad sugar, carrying with it to the simply ignorant family, using it in this state, the cause in a great measure of destroying the tone of the stomach, overloading it, and by and by, the introduction of a kind of dumb ague, or chill, followed with a fever, and often creating intermitting and remitting fevers--consequences arising out of the free use of bad provisions--which diseases are oftentimes kept up by the use of this infamously prepared coffee, for when the country people get sick, coffee is too frequently used as the only diet. It is particularly injurious to bilious habits--souring on the stomach, becoming acid, creating acidity, and preventing the glandular juicy supplies from producing the usual fermentation of the food in the stomach--rendering the chyle vitiated, which in its usual route, imparts from the intestines, nourishment to the blood. Thus conveying its baneful properties by this active vehicle, chyle to the blood, rendering it foetid, discoloured and by and by, often as difficult to be named in its adulterated state as the composition which gave rise to it. Had we not very many instances of new diseases--complaints which the most eminent of the medical faculty can with difficulty name, or treat with judgment, without first having made many essays and experiments fatal to the lives of hundreds, which are increasing with every approaching season, and all since the adoption of coffee. (True, the free use of ardent spirits and other luxuries operating on the effects of indolence--of habits, produced by the wealth and independence of our agricultural and commercial people, and growing out of an imitation of the elevated, affluent of society, born to fortune, and the successful professional characters;) a doubt might present itself as to the propriety of attributing many of those new complaints to coffee ... but to a too plentiful use of bad provisions, and an indulgence of bad habits, we must attribute to them. And as badly made coffee is among the most pernicious kinds of food, and particularly when taken in the morning on an empty stomach, and that too made from very green coffee, (dreadfully poisonous when used too frequently before it acquires age and a whiter colour,) it may be condemned with greater propriety. And whilst this beverage is condemned and so highly to be disapproved of, it is well if we can invent a light, pure, active and healthful beverage to be taken freely, between or at meals, calculated in its nature to correct in some degree, the unhappy effects of bad provisions--it is therefore I mention the _Receipt for making Honey Wine._ I put a quantity of the comb from which the honey had been drained, into a tub, to which I add a barrel of cider, immediately from the press; this mixture was well stirred, and left to soak for one night. It was then strained before a fermentation took place, and honey was added until the weight of the liquor was sufficient to bear an egg. It was then put into a barrel, and after the fermentation commenced, the cask was filled every day for three or four days, with water, that the filth might work out of the bung hole. When the fermentation moderated, I put the bung in loosely, lest stopping it tight, might cause the cask to burst.--At the end of five or six weeks the liquor was drawn off into a tub, and the white of eight eggs well beaten up, with a pint of clean sand, were put into it--I then added a gallon of cider spirit, and after mixing the whole well together, I returned it into the cask, which was well cleaned, bunged it tight and placed it in a proper situation for racking it off when fine. In the month of April following, I drew it off for use, and found it equal in my opinion, to almost any foreign wine--in the opinion of many good judges it was superior. This success has induced me to repeat the experiments for three years, and I am persuaded that by using the clean honey, instead of the comb, as above described; such an improvement might be made as would enable the citizens of the United States, to supply themselves with a truly federal and wholesome wine, which would not cost more than twenty cents per gallon, were all the ingredients procured at the market prices, and would have the peculiar advantage over all other wines, hitherto attempted in this country, that it contains no foreign mixture whatever, but is made from ingredients produced on our own farms. [_Columbian Magazine, November_ 1790. Doubtless the foregoing wine will be found strong, and if not well clarified, or rather fined, may be heavy--and therefore will be found excellent when diluted freely with water, and when about to be drank, two thirds of water will be found necessary, and an improvement. Bottling the foregoing wine in April, will certainly render it more excellent, and I fancy it ought to be drank mixed with water, during warm weather, and between meals, as in its pure state it may be found heavy. The gentleman who made the foregoing experiments, drew it off in kegs--this we presume was done to prevent its souring--as cider will suffer, and become hard after broaching the cask, whereas whilst full it remained sound. All American vinous liquors are liable to sour, because we rarely understand or practice the proper mode of manufacturing. Complete cleansing and fermentation is absolutely necessary--and when fermented, it must be well fined, and then drawn off in nice casks, or bottled--bottling is certainly the most effectual, and if a farmer procures as many as three dozen of black bottles, they with three kegs of seven and an half gallons each, will hold the barrel.--The kegs well bunged, will preserve the wine sound, and when a keg is broached, it must be immediately drawn off and bottled. The bottles when emptied, ought to be rinsed and stood up in an airy closet to drain. _To make Elderberry Wine._ _The editor is happy in introducing the following receipts which he is confident is hardly known in America. The great quantities of the Elderberry, which yearly goes to waste, might with very little trouble be manufactured into one of the most wholesome and agreeable wines ever introduced into America._ To every two quarts of berries, add one gallon of water, boil it half an hour, then strain it, and add to every gallon of liquor, two and an half pounds of sugar, then boil it together for half an hour, and skim it well; when cool (not cold) put in a piece of toasted bread, spread thick with brewer's yeast, to ferment. When you put this liquor into the barrel, which must be done the next day, add to every gallon of liquor, one pound of raisins, chopped, and stir all together in the barrel, once every day, for a week, then stop it close. It will not be fit to tap 'till the spring following the making; and the older the better. _To make Elderberry Wine, to drink, made warm, as a Cordial._ Equal quantities of berries and water boiled together, till the berries break, then strain off the liquor, and to every gallon thereof, put three pounds of sugar, and spice, to your palate, boil all up together, let it stand till it becomes cool, (not cold); then put in a piece of toasted bread, spread thick with brewer's yeast, to ferment, and in two or three days, it will be fit to put in the barrel, then stop it close. This will be fit to drink at Christmas, but the older the better. SECTION XIII. ARTICLE I. _To make Rye Malt for Stilling._ Steep it twenty four hours in warm weather, in cold, forty eight, so in proportion as the weather is hot or cold; drain off the water, lay it in your malt cellar, about fifteen inches thick, for twelve hours; then spread it out half that thickness, sprinkling water on it at the same time; after that, it is to be turned three times a day with care, sprinkling water on as before. The thickness of the bed in this stage, must depend on the weather; work it in this way till the sprout is half as long as the grain, then throw it on your withering floor, wither it there for forty eight hours; then put it on your kiln to dry. ART. II. _Of Brewing Beer._ As the following is intended principally for the use of private families, it will be necessary to begin with directions how to choose good Malt; for which, see page 67. _Of the Brewing Vessels._ To a copper that holds 36 gallons, the mash-tub ought to be at least big enough to contain six bushels of malt, and the copper of liquor, and room for mashing or stirring it: The under back, coolers and working tubs, may be rather fitted for the conveniency of the room, than to a particular size; for if one vessel be not sufficient to hold your liquor, you may take a second. _Of cleaning and sweetening Casks & Brewing Vessels._ If a cask, after the beer is drank out, be well stopt to keep out the air, and the lees remaining in it till you want to use it again, you will need only to scald it well, and take care of the hoops before you fill it; but if air gets into a foul empty cask, it will contract an ill scent in spight of scalding. A handful of bruised pepper boiled in the water you scald with, will take out a little musty smell; but the surest way is to take out the head of the cask, and let the cooper shave and burn it a little, and then scald it for use; if you cannot conveniently have a cooper to the cask, get some stone lime, and put about three pound into a barrel, (and proportionally to smaller or bigger vessels) and put to it about six gallons of cold water, bung it up, and shake it about for some time, and afterwards scald it well; or for want of lime, take a linen rag, and dip it in melted brimstone, and fasten one end to the bung, and light the other, and let it hang on the cask. You must give it a little air, else it will not burn; but keep in as much of the sulphur as you can. Scald it afterwards, and you will find no ill smell. If you have new casks, before you fill them, dig places in the earth, and lay them half their depth with their bung holes downward, for a week; and after well scalding them, you may venture to fill them. Another way to proceed, if your brewing vessels are tinged with any ill smell, is to take unflacked lime and water, and with an old broom scrub the vessel whilst the water is hissing, with the lime; and afterwards take all this lime and water away, and put fresh water into the vessel, and throw some bay or common salt into each, and let it stand a day or two; and when you come to brew, scald your vessels, throw into them a little malt-dust or bran; and this will not only finish their sweetening, but stop them from leaking. But since there is so much trouble in getting vessels sweet after they have been neglected, you ought to make all thorough clean after brewing, and once a month to fill your vessels with fair water, and let it off again in two or three days. _Of mashing or raking your Liquors._ Suppose you take six bushels of malt, and two pounds of hops, and would make of it one barrel of strong, and two barrels of small beer. Heat your first copper of liquor for mashing, and strew over it a double handful of bran or malt; by which you will see when it begins to boil; for it will break and curl, and then it is fit to be let off into the mash tub, where it must remain till the steam is quite spent, and you can see your face in it, before you put in your malt; and then you begin to mash, stirring it all the while you are putting in the malt: but keep out about half a bushel dry, which you are to strew over the rest, when you have done stirring it, which will be as soon as you have well mixed it with the liquor, and prevented it from clodding. After the dry malt is laid on, cover your mash tub with cloths, to prevent losing any spirit of the malt, and let it so remain for two hours. Meanwhile have another copper of liquor hot; and at two hours end begin to let off your first wort into the under-back. Receive a pailful of the first running, and throw it again upon the malt.--You will find that the malt has sucked up half of your first copper of liquor; and therefore to make up your quantity of wort for your strong beer, you must gradually lade out of the second copper, and strew bowl after bowl over the malt, giving it time to soak thro', and keeping it running by an easy stream, till you perceive you have about forty gallons, which in boiling and working will be reduced to thirty-six. If you throw into the under-back (whilst you are letting off) about half a pound of hops, it will preserve it from foxing, or growing sour or ropy. Your first wort being all run off, you must soften the tap of the mash tub; and take a copper of hot liquor for your second mashing, stirring up the malt as you did at first, and then cover it close for two hours more. Meanwhile you fill your copper with the first wort, and boil it with the remainder of the two pounds of hops, for an hour and an half, and then lade it off into the coolers. Contrive to receive the hops in a sieve, basket, or thin woolen bag that is sweet and clean; then immediately fill your copper with cold liquor, renew your fire under it, and begin to let off your second wort, throw a handful of hops into the under-back, for the same reason as before: you will want to lade a few bowls full of liquor over the malt to make up the copper full of second wort; and when you have enough, fasten the tap and mash a third time after the same manner, and cover it close for another two hours; and then charge your copper with the second wort, boiling it for an hour with the same hops. By this time you may shift your first wort out of the coolers into a working tub, to make room for the second wort to come into the coolers; and then your copper being empty, you may heat as much liquor as will serve you to lade over the malt, or, by this time, rather grains, to make up your third and last copper of wort, which must be bottled with the same hops over again; and then your coolers are discharged of your second wort, to make room for the third; and when they are both of a proper coolness, they may be put together before you set them a working. During the time of shifting your liquors out of the copper, it is of consequence to take care to preserve it from receiving damage by burning: you should always contrive to have the fire low, or else to damp it at the time of emptying, and be very expeditious to put in fresh liquor. _Of working the Liquor._ In this, regard must be had to the water: liquor naturally grows warm in working; therefore, in mild weather, it should be cold before it be set on, but a little warm in cold weather. The manner of doing it, is to put some good sweet yeast into a hand-bowl or piggin, with a little warm wort; then put the hand-bowl to swim upon the wort in the working tub, and in a little while it will work out, and leisurely mix with the wort, and when you find the yeast is gotten hold of the wort, you must look after it frequently; and if you perceive it begins to heat and ferment too fast, lade some of it out into another tub; and when grown cold, it may be put back again; or if you reserve some of the raw wort, you may check it leisurely, by stirring it in with a hand-bowl. The cooler you work your liquor, the better, provided it does but work well. If you happen to check it too much, you may forward its working, by filling a gallon stone bottle with boiling water, cork it close and put the bottle into the working tub.--An ounce or two of powdered ginger will have the same effect. There are a variety of methods in managing liquors whilst they are working.--Some people beat the yeast of strong beer and ale, once in two or three hours, for two or three days together. This they reckon makes the drink more heady, but withal hardens it so as to be drinkable in two or three days; the last day of beating it in, (stirring the yeast and beer together) the yeast, as it rises, will thicken; and then they take off part of the yeast, and beat in the rest, which they repeat as often as it rises thick; and when it has done working, they tun it up, so as it may just work out of the barrel. Others again do not beat it in at all, but let their strong drink work about two days, or till they see the ferment is over; and then they take off the top yeast, and either by a tap near the bottom, let it off sine, or else lade it out gently, to leave the sediment and yeast at the bottom. This way is proper for liquor that is to be drank soon: but if it be to keep, it will want the sediment to feed upon, and may probably grow stale, unless you make artificial lees: This you may make of a quart of brandy, and as much flour of wheat as will make it into dough; put them in lumps into the bung hole as soon as it has done working. Or else take a pound of the powder of oyster shells and mix it with a pound of treacle or honey, and put it in soon after it has done working. It would add to the goodness, as well as sining of your malt liquor, if you took two quarts of wheat, and make them very dry and crisp in an oven, or before the fire, and boil them in your first copper of wort.--They would strain off with your hops, and might be put with them into the second copper. _Of the fining of Malt Liquors._ It is most desirable to have beer fine of itself, which it seldom fails to do in due time, if rightly brewed and worked; but as disappointments some times happen, it will be necessary to know what to do in such cases. Ivory shavings boiled in your wort, or hartshorn shavings put into your cask just before you bung it down, will do much towards fining and keeping your liquor from growing stale. Isinglass is the most common thing made use of in fining all sorts of liquors; they first beat it well with a hammer or mallet, and lay it in a pail, and then draw off about two gallons of the liquor to be fined upon it, and let it soak two or three days; and when it is soft enough to mix with the liquor, they take a whisk, and stir it about till it is all of a ferment, and white froth; and they frequently add the whites and shells of about a dozen of eggs, which they beat in with it, and put altogether into the cask; then with a clean mop-stick, or some such thing, stir the whole together; and then lay a cloth, or piece of paper over the bung-hole, till the ferment is over; and then bung it up close, in a few days it will fall fine. But if you want to fine only a small quantity, take half an ounce of unflacked lime, and put it into a pint of water, and stir it well together, and let it stand for two or three hours, or till the lime settle to the bottom; then pour the water off clear, and throw away the sediment; then take half an ounce of isinglass cut small, and boil it in the lime water till it dissolves; then let it cool, and pour it into the vessel, &c. _Of the season for Brewing._ The season for brewing keeping-beer is certainly best before Christmas, for then your malt is in perfection, not having time to contract either a musty smell, dust or weavels, (an insect that eats out the heart of the malt) and the waters are then seldom mixed with snow; and then four pounds of hops will go as far as five in the spring of the year: For you must increase in the quantity of hops as you draw towards summer. But, in short, chuse moderate weather as much as you can for brewing, and if you have a kindly cellar besides to keep your liquor in, that will not be much affected by extremity of heat or cold, you may reasonably expect great satisfaction in your brewery. Avoid as much as possible brewing in hot weather; but if you are necessitated to brew, make no more than present drinking, for it will not keep. _To make Elderberry-Beer or Ebulum._ Take a hogshead of the first and strong wort, and boil in the same one bushel of picked Elderberries, full ripe; strain off, and when cold, work the liquor in the hogshead, and not in an open tun or tub; and after it has lain in the cask about a year, bottle it; and it will be a good rich drink, which they call ebulum; and has often been preferred to portwine, for its pleasant taste, and healthful quality. N. B. There is no occasion for the use of sugar in this operation; because the wort has strength and sweetness enough in itself to answer that end; but there should be an infusion of hops added to the liquor, by way of preservation and relish. Some likewise hang a small bag of bruised spices in the vessel. _To make improved and excellent wholesome Purl._ Take Roman wormwood two dozen, gentian-root six pounds; calamus aromatics (or the sweet flag root) two pounds; a pound or two of the galen gale-root; horse radish one bunch; orange peal dried, and juniper berries, each two pounds; seeds or kernels of Seville oranges cleaned and dried, two pounds. These being cut and bruised, put them into a clean butt, and start your mild brown, or pale beer upon them, so as to fill up the vessel, about the beginning of November, and let it stand till the next season; and make it thus annually. _To brew Strong Beer._ To a barrel of beer take two bushels of wheat just cracked in the mill, and some of the flour sifted out of it; when your water is scalding hot, put it into your mash-vat, there let it stand till you can see your face in it; then put your malt upon that, and do not stir it; let it stand two hours and an half; then let it run into a tub that has two pounds of hops in it, and a handful of rosemary flowers; and when it is all run, put it into the copper, and boil it two hours; then strain it off, setting it a cooling very thin, and setting it a working very cool; clear it very well before you put it a working; put a little yeast to it; when the yeast begins to fall, put it into your vessel, put in a pint of whole grain, and six eggs, then stop it; Let it stand a year, and then bottle it. A good table-beer may be made, by mashing again, after the preceding is drawn off; then let it stand two hours, and let that run, and mash again, and stir it as before; be sure to cover your mashing-vat well; mix the first and second running together. _To make China Ale._ To six gallons of ale, take a quarter of a pound or more of China root, thin sliced, and a quarter of a pound of coriander seeds, bruised--hang these in a tiffany, or coarse linen bag, in the vessel, till it has done working; and let it stand fourteen days before you bottle. _To make Ale, or any other liquor, that is too new, or sweet, drink stale._ To do this to the advantage of health, put to every quart of ale, or other liquor, 10 or 12 drops of the true spirit of salt, and let them be well mixed together, which they will soon do it by the subtile spirits penetrating into all parts, and have proper effect. _To recover sour Ale._ Scrape fine chalk a pound, or as the quantity of liquor requires, more; put it into a thin bag into the ale. _To recover Liquor that is turned bad._ If any liquor be pricked or fading, put to it a little syrup of clay, and let it ferment with a little barm, which will recover it; and when it is well settled, bottle it up, put in a clove or two, with a lump of loaf sugar. _Directions for Bottling._ You must have firm corks, boiled in wort, or grounds of beer; fill within an inch of the cork's reach, and beat it in with a mallet; then, with a small brass wire, bind the neck of the bottle, bring up the ends, and twist them over with a pair of pincers. _To make a quarter of a hogshead of Ale, and a hogshead of Beer, of cooked Malt._ Take five strike of malt not ground too small; put in some boiling water, to cover the bottom of your mashing-vat before you put in your malt; mash it with more boiling water, putting in your malt at several times, that it may be sure to be all wet alike; cover it with a peck of wheat bran, then let it stand thus mashed four hours, then draw off three gallons of wort, and pour it upon that you have mashed, so let it stand half an hour more, till it runs clear, then draw of all that will run, and take two quarts of it to begin to work up with the barm, which must be about a pint and a half--put in the two quarts of wort at three times to the barm; you need not stir it till you begin to put in the boiled wort. You will not have enough to fill your vessel at first; wherefore you must pour on more boiling water, immediately after the other has done running, till you have enough to fill a quarter of a hogshead, and then pour on water for a hogshead of beer. As soon as the ale wort has run off, put a third part into the boiler--when it boils up, take off the scum, which you may put upon the grains for the small beer--when it is skimmed, put in a pound and an half of hops, having first sifted out the seeds, then put in all the wort, and let it boil two hours and an half, afterwards strain into two coolers, and let it stand to cool and settle, then put it to cool a little at a time, to the barm, and two quarts of wort, and beat it well together: every time you put the wort in, be sure you keep the settling out. Suppose you brew early on Thursday morning, you may tun it at 9 or 10 on Saturday morning. Do not fill your vessel quite full, but keep about three gallons to put in, when it has worked 24 hours, which will make it work again. As soon as it hath done working, stop it up, put the drink as cool as you can together; thus it will work well. _To make Treacle Beer._ Boil two quarts of water, put into it one pound of treacle or molasses, stir them together till they are well mixed; then put six or eight quarts of cold water to it, and about a tea cup full of yeast or barm, put it up in a clean cask or stein, cover it over with a coarse cloth, two or three times double, it will be fit to drink in two or three days. The second and third time of making, the bottom of the first beer will do instead of yeast. If you make a large quantity, or intend it for keeping, you must put in a handful of hops and another of malt, for it to feed on, and when done working, stop it up close. The above is the best and cheapest way of making treacle beer, tho' some people add raisins, bran, wormwood, spices, such fruit, &c. as are in season, but that is just as you fancy. Indeed many pleasant, cheap, and wholesome drinks may be made from fruits, &c. if they are bruised and boiled in water, before the treacle is added. The plan of manufacturing domestic wines, mead and small beer, once established and understood in a family, becomes easy--is considered a duty--and the females prepare as regularly for renewing them, as for baking, and doing every other branch of business. Many families amidst plenty of ingredients and means, rarely have a comfortable beverage under their roof--this is attributable to indolence, stupidity and want of knowledge.--A little well timed, planning and system, with little more than usual labour, by the intelligent housewife, will cause comfort and plenty to reign throughout, and prove a fine and salutary example to society. Besides, the pleasure a lady derives from presenting a glass of good wine, in a nice clean glass to her welcome visitants, will always amply compensate for the trouble of manufacturing, and preparing it; but when the more intelligent pass a handsome and well merited compliment on the neatness and quality of her fare--she derives happiness from her industry, and a degree of pleasure approaching to exquisite. She may be esteemed one "who hath used her active faculties for the benefit of her family and society, and not only deserves well of society, but of heaven, for the judicious and liberal exercise of the mind, that god-like intellect, among the finest gifts of the munificent creator of worlds." But of her, who sitteth still and inactive, and doth not exercise those intellectual powers, it may be said "she is of an estrayed soul," and "hath buried her talent." And neither merits the attention of society, or the grateful love of her husband and family--and throws herself on the mercy of her God for forgiveness, for her numerous omissions, in withholding the exercise of her active faculties--presuming the being or individual, who is capable of the neglect of one duty, is capable of neglecting all--and tho' some little appearance may be kept up, yet conviction is eternally in the eye of the great judge--and not to be evaded. Thus then the laws of society, morality and religion, requiring the active exercise of our person and faculties--offering the finest and most inducing rewards, the words of our language are capable of describing, in the health afforded from exercise; the example, from which society is benefitted; the pleasure derived from the approbation of our neighbors, and a conscientiousness of having performed our duties here, and living by the exercise of a proper system of economy, in a constant state of independence, always in possession of the means of alleviating the condition of the indigent and unfortunate in society--and relieving the wants of our friends--and above all, the hope of eternal happiness in the approbation of heaven hereafter. _FINIS_ 
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34348	----	file was produced from images generously made available by The Internet Archive.) [Illustration: KATE FIELD] THE DRAMA OF GLASS BY KATE FIELD PUBLISHED BY THE LIBBEY GLASS CO. The Drama of Glass was an inspiration born in the brain of Kate Field, as she watched the busy workmen, who with trained eyes and skillful hands, wrought out the products of one of America's great industries that found a temporary home in the World's Fair at Chicago. It is an addition to the long list of brilliant writings of this versatile woman, whose literary labors have made her memory so dear to the thousands of Americans who have found in them the reflection of her own individuality. The story of an art that is as old as the building of the City of Babylon, that formed a part in the life of Egypt, that was interwoven in the history of Rome, and that gave a reputation to a nation, is re-told by Miss Field. From the beginning of the art, wrapped in mystery and legend, step by step her story has become history. She has carried it as far as the World's Fair, and it has devolved upon Mr. Thos. M. Willey to complete what she so well begun. [Illustration] PROLOGUE Have you ever thought what a drama glass plays in the history of the world? It is a drama even in the French acceptation of the word, which infers not only intense action, but death. Can there be more intense action than that of fire, and is not glass the own child of fire and death? The origin of glass is lost in myth and romance. Nobody knows how it was born, but there are as many traditions as there are cities claiming to be Homer's birthplace. Pliny says that the discovery of glass was due to substituting cakes of nitre for stones as supports for cooking pots. [Illustration] According to his story, certain Phoenician merchants landed on the coast of Palestine and cooked their food in pots supported on cakes of nitre taken from their cargo. Great was the wonder of these Phoenicians--the Yankees of antiquity, the builders of Tyre and Sidon, the inventors of the alphabet--on beholding solid matter changed to a strange fluid, which voluntarily mingled with its nearest neighbor, the sand, and made a transparent material now called glass. [Illustration] This story is too pretty to spoil, and those of us who prefer romance to science will believe it, though Menet the chemist positively declares that to produce such a fluid would require a heat from 1800 to 2700 degrees Fahrenheit. Under the circumstances narrated by Pliny, such a tremendously high temperature was impossible. Science often interferes with romance, and were not truth better even than poetry, science would be a nuisance in literature. An art that Hermes taught to Egyptian chemists like good wine needs no bush, yet on its brilliant crest may be found the splendid quarterings not only of Egypt, but of Gaul, Rome, Byzantium, Venice, Germany, Bohemia, Great Britain, and last but not least the United States. [Illustration] He was a poor man, who, in Seneca's day, had not his house decorated with various designs in glass; while Scaurus, the Aedile, a superintendent of public buildings in ancient Rome, actually built a theatre seating forty thousand persons, the second story of which was made of glass. That masterpiece of ancient manufacture, the Portland Vase, was taken from the tomb of the Roman Emperor Alexander Severus, and should bear his name rather than that of the Duchess of Portland, who purchased it from the Barberini family after it had stood three hundred years in their famous Roman gallery. In the thirteenth century Venice reigned supreme in glass making. No one knows how long the City of Doges might have monopolized certain features of this art but for a woman who could not keep a secret from her lover. Marietta was the daughter of Beroviero, one of the most famous glass makers of the fifteenth century. Many were his receipts for producing colored glass, and as he had faith in his own flesh and blood he confided these precious receipts to his daughter. Alas, for poor Beroviero! Marietta, after the manner of women, loved a man, one Giorgio, an artisan in her father's employ. History does not tell, but I have no doubt that Giorgio wheedled the secret out of his sweetheart. [Illustration] Once possessed of these receipts he published and sold them for a large sum, then turning on the man he had betrayed he demanded faithless Marietta in marriage. Thus it came to pass that the ignoble love of a weak woman for a dishonorable man helped to change the fortunes of Venice. The world gained by the destruction of a monopoly, one more proof of the poet's dictum that "all partial evil is universal good." [Illustration] It was in the middle of this same fifteenth century that a number of Venetian glass makers were imprisoned in London because they could not pay the heavy fine imposed by the Venetian Council for plying their art in foreign lands. "Let us work out our fine," pleaded these victims of prohibition. Their prayer was warmly seconded by England's king, whose intercession was by no means disinterested. Yielding to royal desire, Venice freed these artisans, and thus glass making was established in Great Britain. Beyond the point of reason all prohibitory laws fail sooner or later. Go to the bottom of slang, and as a rule you will find it based on rugged truth. When in the breezy vernacular of this republic a human being is credited with "sand" or is accused of being entirely destitute of it, he rises to high esteem or falls beneath contempt. Possessing "sand" he can command success; without it he is a poor creature. For the origin of this slang we turn to glass making, the excellence of which depends upon sand. If Bohemia succeeded finally in making clearer and whiter glass than Venice, it was because Bohemia produced better sand. When the town of Murano furnished the world with glass, its population was thirty thousand. That number has dwindled to four thousand. Bohemian glass stood unrivaled until England discovered flint or lead glass; now, the world looks to the United States for rich cut glass, the highest artistic expression of modern glass. Where does America begin its evolution in glass? Before the landing of the Pilgrims at Plymouth Rock. In 1608, within a mile of the English settlement of Jamestown, Virginia, a glass house was built in the woods. Curiously enough it was the first factory built upon this continent. This factory began with bottles, and bottles were the first manufactured articles that were exported from North America. In those early days glass beads were in great demand. Indians would sell their birthright for a mess of them, so when the first glass house fell to pieces, a second took its place for the purpose of supplying the Indians with beads. [Illustration] A few years later common glass was made in Massachusetts. It appears from the records of the town of Salem that the glass makers could not have been very successful, as that town loaned them thirty pounds in money which was never paid back. During the time of the Dutch occupation of Manhattan Island, when New York was known as New Amsterdam, a glass factory was built near Hanover Square, but not until after the Revolution came and went did glass making really take root in American soil. In July, 1787, the Massachusetts Legislature gave to a Boston glass company the exclusive right to make glass in that State for fifteen years. This company prospered and was the first successful glass manufacturing company in the United States. Then followed others that were successful. As early as 1865 there was manufactured, in the vicinity of Boston, glass that was the equal of the best flint glass manufactured in England. Two hundred and fifty years from the time the first rough bottles were exported from Virginia to England seems a long time to us, but how short a time it really is in the life of this ancient art--this drama of glass. [Illustration] FROM 1850 TO 1893 AN EVOLUTION IN GLASS It is always interesting to trace the history of a great industry. Like the oak, it begins with a small seed that hardly knows its own mind, and is often more surprised than the rest of the world at the result of earnest effort. See what apothecaries did for Italy. Mediæval art and the Medicis go hand in hand. The drama of glass in the United States may have as significant a mission, for it is singularly true that James Jackson Jarves, son of Deming Jarves, the pioneer glass manufacturer of New England, was almost the first American to give his life to the study of old masters and to devote his fortune to collecting their works. The Jarves gallery now belongs to Yale University. [Illustration] William L. Libbey was born in Portsmouth, New Hampshire, and became, in 1850, the confidential clerk of Jarves & Commeraiss, the greatest glass importers of Boston, and whose glass factory in South Boston was the forerunner of the Libbey Works of the Columbian Exposition. Having made a fortune--the fortune his clever son spent in art and _bric-a-brac_--Deming Jarves sold his glass factory to his trusted clerk in 1855, and for twenty years this Massachusetts industry gained strength and reputation. But the trend of population was westward. Cheap fuel was necessary to successful glass making. How could New England coal compete with natural gas? So Ohio came to the front. A few years ago Ohio's natural gas became exhausted. Without a day's disturbance petroleum succeeded gas, and better glass was made than ever, because oil produces a more even temperature. Verily "there is a soul of goodness in things evil." From Massachusetts to Ohio, from coal to gas, from gas to petroleum, what would be the next act in the drama of American glass? What, indeed, but an act the scene of which was laid in the grounds of the World's Fair! Believing fully in the westward course of empire, Mr. Edward D. Libbey had the inspiration that if Chicago wanted the World's Fair, Chicago would not only have it, but would create such an exposition as had never been seen. So before even the temporary organization was formed in Chicago the Libbey Glass Company filed an application for the exclusive right to manufacture glass at the Columbian Exposition. The problem of erecting a building that should be architecturally in keeping with the surroundings, that should afford every possible comfort to the thousands of daily visitors and still be used as a manufactory, was not an easy matter. Begun in October, 1892, the admirable building, put up in the Midway Plaisance to show the process of making glass, was finished one week before May 1st following. On that bleak opening day thousands of overshoes were stalled in mud a foot deep before the Administration Building, and the owners went home in some cases almost barefooted. [Illustration] But there was an expenditure of $125,000 in an idea, and the investors had no reason to fear weather or neglect. From the opening to the closing of the big front door two million people found their way to this glass house, at which no one threw stones. The trouble was not to get people in, but to keep them out. A mob never benefits itself nor anybody else. To reduce the attendance to reasonable proportions a fee was charged, applicable to the purchase of some souvenir, made perhaps before the buyer's very eyes. Why was this glass house so popular? Because its exhibit displayed the only art industry in actual operation within the Fair grounds. All people like machinery in motion, and the most curious people on earth are Americans. They want to know how things are made, and, like children, are not content until they have laid their hands on whatever confronts them. "Please do not touch" has no terrors for them. In addition to this inborn love of action, there is a fascination about glass blowing and the fashioning of shapeless matter piping hot from the pot that appeals to men and women of all sorts and conditions. With eyes and mouths wide open, thousands stood daily around the circular factory watching a hundred skilled artisans at work. They looked at the big central furnace, in which sand, oxide of lead, potash, saltpetre and nitrate of soda underwent vitrification; they saw it taken out of the pot a plastic mass, which, through long, hollow iron tubes, was blown and rolled and twisted and turned into things of beauty. Here was a champagne glass, there was a flower bowl; now came a decanter, followed by a jewel basket. A few minutes later jugs and goblets and vases galore passed from the nimble fingers of the artisans to the annealing oven below. [Illustration] All these creations entered the oven as hot as they came from the last manipulator, but gradually cooled off to the temperature of the atmosphere. Getting used to the hardships of life requires twenty-four hours, during which the trays on which the glass stands are slowly moved from the hot to the temperate end of the oven. This procession was an object lesson in life as well as in glass. "Make haste slowly or you'll defeat yourself," was the burden of the song those things of beauty sang to themselves and to all who listened. If American cut glass has grown beyond compare, it is largely due to the superior intelligence of American artisans. They have the "sand": so, too, have the beautiful hills of Berkshire County, Massachusetts, whence comes the purest quality the whole world has known. The best flint glass exhibited at the Paris Exposition of 1867 owed its excellence to the treasure stowed away in Western Massachusetts. [Illustration] The finest American flint glass of the Columbian Exposition found its inspiration in the same part of the old Bay State. Little did those visitors to the Fair know whence came the hot fires of Libbey's Glass House. They little knew that oil was drawn in pipes from Ohio, and that one hundred and fifty barrels of petroleum lay buried under innocent-looking grass, that looked up and asked not to be trodden under foot. Of course, had lightning struck those two great hidden tanks of liquid dynamite, we should all have been sent to that bourne whence no World's Fair visitor could have returned. Seventy-five barrels of oil were burned daily on the Midway Plaisance. How many gallons? Three thousand. Multiply one day's fire by one hundred and eighty days and you discover that the drama of glass at the Fair was the death of fifty-four thousand gallons of petroleum. EPILOGUE THE ACTRESS AND THE INFANTA [Illustration: GEORGIA CAYVAN] Ever since the era of fairy tales the world has heard of glass slippers. Cinderella wore them and great was the romance thereof. But whoever before 1893 heard of a glass dress, and who conceived such a novel idea? [Illustration] From that memorable day in the Garden of Eden when Eve ate that apple, which may literally be called the fruit of all knowledge, woman has been at the bottom of everything: it was a woman who got it into her head that she wanted a glass dress. How did it happen? Thus: In the middle of May, 1893, women from all parts of the earth took Chicago by storm. Theirs was the first of one hundred congresses, and among many artists was Georgia Cayvan, whose record on and off the stage does credit to her head and heart. Of course the clever actress visited the Fair and of course she followed the multitude and found herself watching the process of making American glass. It was not long before Miss Cayvan's quick eye was attracted by an exhibit of spun and woven glass lamp shades. "Do you mean to say those shades are spun out of glass?" she exclaimed; "the material resembles silk." "Nevertheless it is glass," replied the attendant. "Is it possible to make a glass dress?" [Illustration] "Why not? It is not only possible but eminently feasible." "Would it be very expensive?" "Twenty-five dollars a yard." This was a deal of money to invest in an experiment, as at least twelve yards are needed for a gown, but when a woman wills she wills, especially when she is intimately acquainted with her own mind. Miss Cayvan knows hers perfectly, and in a few minutes she exacted from the Company a promise not only to spin her many yards of glass cloth for a white evening costume, but she obtained from them the exclusive right to wear glass cloth on the stage. "It is agreed," said actress and manufacturer in chorus, and off hied the former to New York, where at the end of four weeks she received her material direct from the Midway Plaisance. How to make it up was the next question, for Madame la Modiste vowed she wouldn't touch such material with scissors and needles. [Illustration: INFANTA EULALIA] As a matter of fact a specialist is needed to cut and sew glass, which differs from other cloths in breaking and wickedly sticking into the hands, so a skillful and artistic young woman employee from Toledo was sent to New York to do what the ordinary seamstress could not. She cut and made the unique costume with which Miss Cayvan sweeps the stage to the edification of feminine and the wonder of masculine eyes. The fame of that glass gown reached the ears of the Infanta Eulalia, who saw it worn by the ingenious actress and determined to inspect its counterpart set up in a case at the World's Fair. The Midway Plaisance was the Princess's favorite resort in Chicago, and she soon turned her steps toward the glass house she had heard so much about. "Where's that dress?" asked the Infanta as she entered the factory. On being conducted to it Eulalia expressed great pleasure, declaring it was the finest thing she had seen at the Fair. "Would Your Highness wear such a gown were one made expressly for you?" she was asked. [Illustration] "Not only would I wear it, but I'd take the greatest delight in telling the story of its manufacture," replied the Princess. Before sailing away to Spain, Eulalia was fitted for her American glass gown, now wears it, and today there hangs in the Libbey Glass Company's private office the following official certificate: ROYAL HOUSE OF H. R. H. INFANTE DON ANTONIO DE ORLEANS H. R. H. Infante Antonio de Orleans appoints Messrs. Libbey and Company of Toledo, Ohio, cut-glass makers to his royal house, with the use of his royal coat-of-arms for signs, bills and labels. In fulfillment of the command of His Royal Highness I present this certificate, signed in Madrid, July 15th, 1893. PEDRO JOVER FOVAR Superintendent of His Royal Highness's Household Thus for the first time in the history of an industry almost as old as humanity, glass adorns alike the person of a Royal Princess and the person of a charming actress. Produced at the Court of Spain and on the American stage, am I not justified in calling this memory of a far and near past "The Drama of Glass"? KATE FIELD THE DRAMA OF GLASS BY KATE FIELD In every story told of the sights worth seeing at the Columbian Exposition the factory of the Libbey Glass Company, of Toledo, Ohio, has had an important part. It was more than a mere exhibit; it was a practical education in the art of glass making, which, like an easy lesson that follows step by step, from the mixing of the crude material to the completion of the finest piece of cut glass, impressed itself upon the minds of hundred of thousands of visitors. [Illustration] Recall in your memory your visit to the World's Fair in 1893. Place yourself upon the Midway Plaisance, directly opposite the Woman's Building. Does your mind picture a stately, beautiful building, with central dome and graceful towers? This was the building of the glass factory to whom the exclusive right to manufacture and sell its products was awarded over many competitors by the Ways and Means Committee of the World's Columbian Exposition. This concession was given because the plan of the Libbey Glass Company was a plan of broad ideas, fully meeting the requirement that America should show that the whole world followed her in the manufacture of cut glass. [Illustration] How well that Company fulfilled its mission is known to the two million visitors who passed under the deep-recessed semicircular archway, rich with sculptured ornament, that covered the grand entrance to this palace; within, it was like a theatre, where the scenes in the beautiful drama of glass were ever changing. Do you remember that the sides, the dome, the ceiling, were all glitter and sheen with the products of this mystic art, and that from thousands of cut-glass pieces, as from brilliant diamonds, sparkled the prismatic hues? [Illustration] Do you remember the roaring furnace a hundred feet high, the melting pots made of the clays of the Old and the New Worlds, mixed by the bare feet in order that they have the requisite consistency? The products of this factory were born of fire. The plastic molten mass that came from the melting furnace, with its heat of 2200 degrees Fahrenheit, was thirty hours before a mixture called by glass makers a "batch," whose chief ingredient was sand from the hills of Massachusetts. [Illustration] Did you watch the workmen--the "gatherer" and the "blower," with their long, hollow iron pipes? How the "blower," with his trained fingers, gave an easy, constantly swaying motion to the pipe, into which he blew and expanded the hot glass at its end? The tempering oven, through which all glass productions must pass before they will resist changes in temperature or even stand transportation? Did you follow the process of cutting glass; see the wheels like grindstones, driven by steam power? Wheels of stone that come from England and Scotland, and carry with them the old-country names of Yorkshire Flag, New Castle and Craigleith, stones that are very hard and close-grained, capable of retaining a very sharp edge? Wheels of iron, which are used to cut the design in the rough; wheels of wood, cork, felt, and revolving brush wheels, used in finishing and polishing? Did you know that the trained eye of the cutter and his experience were the only guides he had to secure the requisite depth to his cutting; that he must exercise great care and judgment, else the vibration of the glass renders it extremely liable to break, and that an intricate design requires many days of constant manipulation? Did you watch with interest the making of glass cloth, see how the thread of glass was drawn out and wound on the big wheels that revolved hundreds of times a minute? How the glass thread was woven with the silk thread, producing a pliable glass cloth of soft sheen and lustre, that could be folded, pleated and handled in all ways like cloth? Do you recall the Crystal Art Room? Did you realize that under that ceiling, bedecked with ten thousand dollars' worth of spun glass cloth, was collected the finest display of cut glass the world had ever seen? Do you remember an old glass punch bowl, used in 1840 by Henry Clay, and that near this relic of ancient glassware was another punch bowl upon which five hundred dollars' worth of labor had been bestowed? [Illustration] Did you mark the difference, the deep and brilliant cuttings, how effective they were, how they brought out the beauty and richness of the design? Then, when you examined the hundreds of other articles, the sherbet and punch glasses in Roman shapes, the quaint decanters in Venetian forms, the celery trays, flower vases, and the ice-cream sets and cut-glass dishes for every use, you saw the clearness of the glass itself, and that this deep and brilliant cutting of perfect design, that brought out the beauties of the great punch bowl, was a marked characteristic of the Libbey Cut Glass. Did you not, as an American, feel proud of the progress that your countrymen had made in this old art of glass making? Since the World's Fair at Chicago, two expositions of the industries of this country, the San Francisco Midwinter Fair and the Atlanta Exposition, have added to the honors and reputation of the cut glass of the Libbey Company. Certain trade-marks and names on silver and china are always looked upon with pleasure and with a feeling that the possessor has the genuine article. The same thing applies to cut glassware, so as a protection to the public against those who would profit by the reputation of others, the Libbey Glass Company cut their trade-mark--the name Libbey with a sword under it--upon every piece of glass they manufacture. Half a century in the life of America has added much to the art upon whose brilliant crest, as Miss Field has said, may be found the splendid quarterings of Egypt, Rome, Venice, Germany and Great Britain, and today the United States stands unrivaled in the manufacture of cut glass. The honor conferred upon the Libbey Glass Company by the committee, in granting to them the exclusive concession to manufacture and sell American glassware within the grounds of the Exposition during the World's Fair, was a great one. The honors conferred by the San Francisco and Atlanta Expositions are but added proofs that the selection was a proper one. The Libbey Glass Company thus stands today to represent the best the United States produces in cut glass, and the best the United States produces is the world's best. [Illustration] Bartlett & Company The Orr Press New York 
32962	----	generously made available by The Internet Archive/American Libraries.) A HANDBOOK OF LABORATORY GLASS-BLOWING _To my Friends Eric Reid and Sidney Wilkinson_ A Handbook of Laboratory Glass-Blowing BY BERNARD D. BOLAS WITH NUMEROUS DIAGRAMS IN THE TEXT BY NAOMI BOLAS [Illustration] LONDON GEORGE ROUTLEDGE & SONS, LTD NEW YORK: E. P. DUTTON & CO. 1921 CONTENTS CHAP. PAGE I. Introduction and Preliminary Remarks--General Principles to be observed in Glass Working--Choice of Apparatus--Tools and Appliances--Glass 1 II. Easy Examples of Laboratory Glass-Blowing--Cutting and Sealing Tubes, Tubes for High Temperature Experiments--Thermometer-Bulbs, Bulbs of Special Glass, Pipettes, Absorption-Bulbs or Washing Bulbs--Joining Tubes, Branches, Exhaustion-Branches, Branches of Dissimilar Glass, Blowing Bulbs, A Thistle Funnel, Cracking and Breaking Glass, Leading and Direction of Cracks--Use of Glass Rod or Strips of Window-Glass, Joining Rod, Feet and Supports--Gripping Devices for use in Corrosive Solutions--The Building up of Special Forms from Solid Glass 10 III. Internal Seals, Air-Traps, Spray Arresters, Filter-Pumps--Sprays, Condensers; plain, double surface, and spherical--Soxhlet Tubes and Fat Extraction Apparatus--Vacuum Tubes, Electrode Work, Enclosed Thermometers, Alarm Thermometers ... Recording Thermometers, "Spinning" Glass 32 IV. Glass, its Composition and Characteristics--Annealing--Drilling, Grinding, and Shaping Glass by methods other than Fusion--Stopcocks--Marking Glass--Calibration and Graduation of Apparatus--Thermometers--Exhaustion of Apparatus--Joining Glass and Metal--Silvering Glass 55 V. Extemporised Glass-Blowing Apparatus--The use of Oil or other Fuels--Making Small Rods and Tubes from Glass Scraps--The Examination of Manufactured Apparatus with a view to Discovering the Methods used in Manufacture--Summary of Conditions necessary for Successful Glass-Blowing 80 Index 105 PREFACE To cover the whole field of glass-blowing in a small handbook would be impossible. To attempt even a complete outline of the methods used in making commercial apparatus would involve more than could be undertaken without omitting the essential details of manipulation that a novice needs. I have, therefore, confined myself as far as possible to such work as will find practical application in the laboratory and will, I hope, prove of value to those whose interests lie therein. The method of treatment and somewhat disjointed style of writing have been chosen solely with the view to economy of space without the undue sacrifice of clearness. BERNARD D. BOLAS. Handbook of Laboratory Glass-Blowing CHAPTER I Introduction and Preliminary Remarks--General Principles to be observed in Glass Working--Choice of Apparatus--Tools and Appliances--Glass. Glass-blowing is neither very easy nor very difficult; there are operations so easy that the youngest laboratory boy should be able to repeat them successfully after once having been shown the way, there are operations so difficult that years are needed to train eye and hand and judgment to carry them out; but the greater number of scientific needs lie between these two extremes. Yet a surprisingly large number of scientific workers fail even to join a glass tube or make a T piece that will not crack spontaneously, and the fault is rather one of understanding than of lack of ability to carry out the necessary manipulation. In following the scheme of instruction adopted in this handbook, it will be well for the student to pay particular attention to the reason given for each detail of the desirable procedure, and, as far as may be, to memorise it. Once having mastered the underlying reason, he can evolve schemes of manipulation to suit his own particular needs, although, as a rule, those given in the following pages will be found to embody the result of many years' experience. There is a wide choice of apparatus, from a simple mouth-blowpipe and a candle flame to a power-driven blower and a multiple-jet heating device. All are useful, and all have their special applications, but, for the present, we will consider the ordinary types of bellows and blowpipes, such as one usually finds in a chemical or physical laboratory. The usual, or Herepath, type of gas blowpipe consists of an outer tube through which coal gas can be passed and an inner tube through which a stream of air may be blown. Such a blowpipe is shown in section by Fig. 1. It is desirable to have the three centring screws as shown, in order to adjust the position of the air jet and obtain a well-shaped flame, but these screws are sometimes omitted. Fig. 1, _a_ and _b_ show the effects of defective centring of the air jet, _c_ shows the effect of dirt or roughness in the inside of the air jet, _d_ shows a satisfactory flame. [Illustration: Fig 1] For many purposes, it is an advantage to have what is sometimes known as a "quick-change" blowpipe; that is one in which jets of varying size may be brought into position without stopping the work for more than a fraction of a second. Such a device is made by Messrs. Letcher, and is shown by _e_, and in section by _f_ Fig. 1. It is only necessary to rotate the desired jet into position in order to connect it with both gas and air supplies. A small bye-pass ignites the gas, and adjustment of gas and air may be made by a partial rotation of the cylinder which carries the jets. For specially heavy work, where it is needed to heat a large mass of glass, a multiple blowpipe jet of the pattern invented by my father, Thomas Bolas, as the result of a suggestion derived from a study of the jet used in Griffin's gas furnace, is of considerable value. This jet consists of a block of metal in which are drilled seven holes, one being central and the other six arranged in a close circle around the central hole. To each of these holes is a communication way leading to the gas supply, and an air jet is arranged centrally in each. Each hole has also an extension tube fitted into it, the whole effect being that of seven blowpipes. In order to provide a final adjustment for the flame, a perforated plate having seven holes which correspond in size and position to the outer tubes is arranged to slide on parallel guides in front of these outer tubes. [Illustration: Fig. 2] The next piece of apparatus for consideration is the bellows, of which there are three or more types on the market, although all consist of two essential parts, the blower or bellows proper and the wind chamber or reservoir. Two patterns are shown in Fig. 2; _a_, is the form which is commonly used by jewellers and metal workers to supply the air blast necessary for heating small furnaces. Such a bellows may be obtained at almost any jewellers' supply dealer in Clerkenwell, but it not infrequently happens that the spring in the wind chamber is too strong for glass-blowing, and hence the air supply tends to vary in pressure. This can be improved by fitting a weaker spring, but an easier way and one that usually gives fairly satisfactory results, is to place an ordinary screw-clip on the rubber tube leading from the bellows to the blowpipe, and to tighten this until an even blast is obtained. Another form of bellows, made by Messrs. Fletcher and Co., and common in most laboratories, is shown by _b_; the wind chamber consists of a disc of india-rubber clamped under a circular frame or tied on to a circular rim. This form is shown by Fig. 2, _b_. The third form, and one which my own experience has caused me to prefer to any other, is cylindrical, and stands inside the pedestal of the blowpipe-table. A blowpipe-table of this description is made by Enfer of Paris. There is no need, however, to purchase an expensive table for laboratory use. All the work described in this book can quite well be done with a simple foot bellows and a quick-change blowpipe. Nearly all of it can be done with a single jet blowpipe, such as that described first, or even with the still simpler apparatus mentioned on page 84, but I do not advise the beginner to practise with quite so simple a form at first, and for that reason have postponed a description of it until the last chapter. Glass-blowers' tools and appliances are many and various, quite a number of them are better rejected than used, but there are a few essentials. These are,--file, glass-knife, small turn-pin, large turn-pin, carbon cones, carbon plate, rubber tube of small diameter, various sizes of corks, and an asbestos heat reflector. For ordinary work, an annealing oven is not necessary, but one is described on page 60 in connection with the special cases where annealing is desirable. Fig. 3 illustrates the tools and appliances. _a_ is an end view of the desirable form of file, and shows the best method of grinding the edges in order to obtain a highly satisfactory tool. _b_ is a glass knife, shown both in perspective and end view, it is made of glass-hard steel and should be sharpened on a rough stone, such as a scythe-stone, in order to give a slightly irregular edge. _c_ is a small turn-pin which may be made by flattening and filing the end of a six-inch nail. _d_ is the large turn-pin and consists of a polished iron spike, about five inches long and a quarter of an inch diameter at its largest part. This should be mounted in a wooden handle. _e_ and _f_ are carbon cones. A thin rubber tube is also useful; it may be attached to the work and serve as a blowing tube, thus obviating the necessity of moving the work to the mouth when internal air pressure is to be applied. In order to avoid undue repetition, the uses of these tools and appliances will be described as they occur. [Illustration: Fig. 3] Glass, as usually supplied by chemical apparatus dealers is of the composition known as "soda-glass." They also supply "hard" or "combustion" glass, but this is only used for special purposes, as it is too infusible for convenient working in the ordinary blowpipe flame. Soda-glass consists primarily of silicate of sodium with smaller quantities of silicate of aluminum and potassium. Its exact composition varies. It is not blackened, as lead glass is, by exposure to the reducing gases which are present in the blue cone of a blowpipe flame, and hence is easier for a beginner to work without producing discolouration. Further notes on glasses will be found on page 55, but for ordinary purposes soda-glass will probably be used. CHAPTER II Easy Examples of Laboratory Glass-Blowing--Cutting and Sealing Tubes for Various Purposes; Test-Tubes, Pressure-Tubes, Tubes for High Temperature Experiments--Thermometer-Bulbs, Bulbs of Special Glass, Pipettes, Absorption-Bulbs or Washing-Bulbs--Joining Tubes; Branches, Exhaustion-Branches, Branches of Dissimilar Glass--Blowing Bulbs; A Thistle Funnel; Cracking and Breaking Glass; Leading and Direction of Cracks--Use of Glass Rod or Strips of Window-Glass; Joining Rod, Feet and Supports--Gripping Devices for use in Corrosive Solutions--The Building Up of Special Forms from Solid Glass. Perhaps the most common need of the glass-blower whose work is connected with that of the laboratory is for a sealed tube; and the sealing of a tube is an excellent preliminary exercise in glass-blowing. We will assume that the student has adjusted the blowpipe to give a flame similar to that shown in _d_, Fig. 1, and that he has learned to maintain a steady blast of air with the bellows; further, we will assume that the tube he wishes to seal is of moderate size, say not more than half an inch in diameter and with walls of from one-tenth to one-fifth of an inch thick. [Illustration: Fig. 4] A convenient length of tube for the first trial is about one foot; this should be cut off from the longer piece, in which it is usually supplied, as follows:--lay the tube on a flat surface and make a deep cut with the edge of a file. Do not "saw" the file to and fro over the glass. If the file edge has been ground as shown in _a_, Fig. 3, such a procedure will be quite unnecessary and only involve undue wear; one movement with sufficient pressure to make the file "bite" will give a deep cut. Now rotate the tube through about one-eighth of a turn and make another cut in continuation of the first. Take the tube in the hands, as shown in _a_, Fig. 4, and apply pressure with the thumbs, at the same time straining at the ends. The tube should break easily. If it does not, do not strain too hard, as it may shatter and cause serious injuries to the hands, but repeat the operation with the file and so deepen the original cuts. In holding a tube for breaking, it is important to place the hands as shown in sketch, as this method is least likely to cause shattering and also minimises the risk of injury even if the tube should shatter. To cut a large tube, or one having very thick walls, it is better to avoid straining altogether and to break by applying a small bead of intensely heated glass to the file cut. If the walls are very thin, a glass-blower's knife should be used instead of a file. The tube and glass-blower's knife should be held in the hand, and the tube rotated against the edge of the knife; this will not produce a deep cut, but is less likely to break the tube. A bead of hot glass should be used to complete the work. The next operation is to heat the glass tube in the middle; this must be done gradually and evenly; that is to say the tube must be rotated during heating and held some considerable distance in front of the flame at first; otherwise the outer surface of the glass will expand before the interior is affected and the tube will break. From two to five minutes, heating at a distance of about eight inches in front of the flame will be found sufficient in most cases, and another minute should be taken in bringing the tube into the flame. Gradual heating is important, but even heating is still more important and this can only be obtained by uniform and steady rotation. Until the student can rotate a tube steadily _without thinking about it_, real progress in glass-blowing is impossible. When the tube is in the flame it must be held just in front of the blue cone and rotated until the glass is soft enough to permit the ends to be drawn apart. Continue to separate the ends and, at the same time, move the tube very slightly along its own axis, so that the flame tends to play a little more on the thicker part than on the drawn-out portion. If this is done carefully, the drawn-out portion can be separated off, leaving only a slight "bleb" on the portion it is desired to seal. This is illustrated by _b_, Fig. 4. To convert the seal at _b_, Fig. 4., into the ordinary form of test-tube seal, it is only necessary to heat the "bleb" a little more strongly, blow gently into the tube until the thick portion is slightly expanded, re-heat the whole of the rounded end until it is beginning to collapse, and give a final shaping by careful blowing after it has commenced to cool. In each case the glass must be removed from the flame before blowing. The finished seal is shown by _c_, Fig. 4. If desired, the open end may now be finished by heating and rotating the soft glass against the large turn-pin, as illustrated in _d_, but the turn-pin must not be allowed to become too hot, as if this happens it will stick to the glass. After turning out the end, the lip of glass must be heated to redness and allowed to cool without coming in contact with anything; otherwise it will be in a condition of strain and liable to crack spontaneously. The finished test-tube is shown by _e_. When it is necessary to seal a substance inside a glass tube, the bottom of the tube is first closed, as explained above, and allowed to cool; the substance, if a solid, is now introduced, but should not come to within less than two inches of the point where the second seal is to be made. If the substance is a liquid it can more conveniently be introduced at a later stage. Now bring the tube into the blowpipe flame gradually, and rotate it, while heating, at the place where it is to be closed. Allow the glass to soften and commence to run together until the diameter of the tube is reduced to about half its original size. Remove from the flame and draw the ends apart, this should give a long, thick extension as shown by _f_, Fig. 4. If any liquid is to be introduced, it may now be done by inserting a thin rubber or other tube through the opening and running the liquid in. A glass tube should be used with caution for introducing the liquid, as any hard substance will tend to scratch the inside of the glass and cause cracking. The final closure is made by melting the drawn-out extension in the blowpipe flame; the finished seal being shown by _g_, Fig. 4. If the sealed tube has to stand internal pressure, it is desirable to allow the glass to thicken somewhat more before drawing out, and the bottom seal should also be made thicker. For such a tube, and especially when it has to stand heating, as in a Carius determination of chlorine, each seal should be cooled very slowly by rotating it in a gas flame until the surface is covered with a thick layer of soot, and it should then be placed aside in a position where the hot glass will not come in contact with anything, and where it will be screened from all draughts. _Joining Tube._--We will now consider the various forms of join in glass tubing which are met with in the laboratory. First, as being easiest, we will deal with the end-to-end joining of two tubes of similar glass. _a_, _b_, and _c_, Fig. 5, illustrate this. One end of one of the tubes should be closed, a lip should be turned out on each of the ends to be joined, and both lips heated simultaneously until the glass is thoroughly soft. Now bring the lips together gently, until they are in contact at all points and there are no places at which air can escape; remove from the flame, and blow slowly and very cautiously until the joint is expanded as shown in _b_, Fig. 5. Reheat in the flame until the glass has run down to rather less than the original diameter of the tube, and give a final shaping by re-blowing. The chief factors of success in making such a join are, thorough heating of the glass before bringing the two tubes together, and avoidance of hard or sudden blowing when expanding the joint. The finished work is shown by _c_, Fig. 5. [Illustration: Fig. 5] To join a small glass tube to the end of a large one, the large tube should first be sealed, a small spot on the extreme end of the seal heated, and air pressure used to expand the heated spot as shown in _d_. This expanded spot is then re-heated and blown out until it bursts as shown in _e_, the thin fragments of glass are removed and the end of the small tube turned out as shown in _f_. After this the procedure is similar to that used in jointing two tubes of equal size. When these two forms of joint have been mastered, a T piece will present but little difficulty. It is made in three stages as shown in Fig. 5, and the procedure is similar to that used in joining a large and small tube. Care should be taken to avoid softening the top of the "T" too much, or the glass will bend and distort the finished work; although a slight bend can be rectified by re-heating and bending back. Local re-heating is often useful in giving the joint its final shape. An exhaustion branch is often made by a totally different method. This method is shown by _g_, _h_, and _i_, Fig. 5; _g_ is the tube on which the branch is to be made. The end of a rod of similar glass should be heated until a mass of thoroughly liquid glass has collected, as shown, and at the same time a spot should be heated on that part of the tube where it is desired to make the branch. The mass of hot glass on the rod is now brought in contact with the heated spot on the tube and expanded by blowing as shown by _h_. The air pressure in the tube is still maintained while the rod is drawn away as shown by _i_. This will give a hollow branch which may be cut off at any desired point, and is then ready for connection to the vacuum pump. If the rod used is of a dissimilar glass, the branch should be blown much thinner. Such a branch will often serve as a useful basis for joining two tubes of different composition, as the ordinary type of branch is more liable to crack when made with two glasses having different coefficients of expansion. _Blowing Bulbs._--A bulb may be blown on a closed tube such as that shown by _c_, Fig. 5, by rotating it in the blowpipe flame until the end is softened, removing it from the flame and blowing cautiously. It is desirable to continue the rotation during blowing. In the case of a very small tube, it is sufficient to melt the end without previous sealing, rotate it in the flame until enough glass has collected, remove from the flame and blow while keeping the tube in rotation. _Thermometer Bulbs._--If the thermometer is to be filled with mercury, it is desirable to use a rubber bulb for blowing, as moisture is liable to condense inside the tube when the mouth is used, and this moisture will cause the mercury thread to break. In any case, a slight pressure should be maintained inside the thermometer tube while it is in the flame; otherwise the fine capillary tube will close and it will be very difficult to expand the heated glass into a bulb. _Large Bulbs._--When a large bulb is needed on a small or medium sized tube, it is often necessary to provide more glass than would be obtained if the bulb were blown in the ordinary way. One method is to expand the tube in successive stages along its axis, as shown by _a_, Fig. 6. These expanded portions are then re-heated, so that they run together into one hollow mass from which the bulb is blown; _b_ and _c_, illustrate this. Another method, and one which is useful for very large bulbs, is to fuse on a length of large, thick-walled, tubing. The heat reflector, _g_, Fig. 3, should be used, if necessary, when making large bulbs. It consists of a sheet of asbestos mounted in a foot, and is used by being placed close to the mass of glass on the side away from the blowpipe flame while the glass is being heated. [Illustration: Fig. 6] _Bulbs of Dissimilar Glass._--These may be made by the second method given under "Large Bulbs," but the joint should be blown as thin as possible. Further instructions in the use of unlike glasses are given on page 94. _A Bulb in the Middle of a Tube._--Unless the bulb is to be quite small, it will be necessary to join in a piece of thick glass tubing, or to draw the thin tube out from a larger piece, thus leaving a thick mass in the middle as shown by _d_, Fig. 6. This mass of glass should now be rotated in the blowpipe flame until it is quite soft and on the point of running together. Considerable practice will be necessary before the two ends of the tube can be rotated at the same speed and without "wobbling," but this power must be acquired. When the glass is thoroughly hot, remove from the flame, hold in a horizontal position, and expand by blowing. It is essential to continue the rotation while this is done. Should one part of the bulb tend to expand more than the other, turn the expanded part to the bottom, pause for about a second, both in rotating and blowing, in order that the lower portion may be cooled by ascending air-currents; then continue blowing and turning as before. _Absorption Bulbs or Washing Bulbs._--These are made by an elaboration of the processes given in the last paragraph, _g_, _h_, and _i_, Fig. 6, illustrate this. _A Thistle Funnel._--This is made by blowing a fairly thick-walled bulb on a glass tube, bursting a hole by heating and blowing, and enlarging the burst-out part by heating and rotating against a turn-pin. _Bending Glass Tube._--Small tubing may be bent in a flat flame gas burner and offers no special difficulty. Large or thin-walled tubing should be heated in the blowpipe flame and a slight bend made; another zone of the tube, just touching the first bend, should now be heated and another slight bend made. In this way it is possible to avoid flattening and a bend having any required angle can gradually be produced. A final shaping of the bend may be made by heating in a large blowpipe flame and expanding slightly by air pressure. _Glass Spirals._--If a tube is heated by means of a long, flat-flame burner, the softened tube may be wound on to an iron mandrel which has previously been covered with asbestos. The mandrel should be made slightly conical in order to facilitate withdrawal. It is desirable to heat the surface of the asbestos almost to redness by means of a second burner, and thus avoid undue chilling of the glass and the consequent production of internal strain. [Illustration: Fig. 7] _A Thermo-Regulator for Gas._--Fig. 7, _a-e_, shows an easily constructed thermo-regulator. The mercury reservoir, _a_, and the upper part, _b_, are made by joining two larger pieces of tubing on to the capillary. The gas inlet passes through a rubber stopper, in order to allow of adjustment for depth of insertion, and the bye-pass branches, _d_ and _e_, are connected by a piece of rubber tubing which can be compressed by means of a screw clip, thus providing a means of regulating the bye-pass. _Use of Glass Rod._--Apart from its most common laboratory use for stirring; glass rod may be used in building up such articles as insulating feet for electrical apparatus or acid-resisting cages for chemical purposes. Such a cage is shown by _f_, _g_ and _h_, Fig. 7. Further, by an elaboration of the method of making an exhaustion branch, given on page 18, blown articles may also be constructed from rod. Note the added parts of _e_, Fig. 9. _A Simple Foot._--The form of foot shown by Fig. 7, _k_, is easy to make and has many uses. First join a glass rod to a length of glass tubing as shown (the joint should be expanded slightly by blowing), cut off the tube and heat the piece remaining on the rod until it can be turned out as shown by _i_. This should be done with the large turn-pin, and care should be taken not to heat the supporting rod too strongly, otherwise the piece of tube will become bent and distorted; it is better to commence by heating the edge of the piece of tube and turn out a lip, then extend the heating by degrees and turn out more and more until the foot looks like that shown by _i_. We now need to make three projections of glass rod. These are produced as follows:--Heat the end of the glass rod until a thoroughly melted mass of glass has accumulated (the rod must be rotated while this is being done, otherwise the glass will drop off); when sufficient melted glass has been obtained, the edge of the turned-out foot should be heated to dull redness over about one-third of its circumference, and the melted glass on the rod should be drawn along the heated portion until both are so completely in contact as to form one mass of semi-fluid glass. The rod should now be drawn away slowly, and, finally, separated by melting off, thus producing a flat projection. A repetition of the process will give the other two projections, and the finished foot may be adjusted to stand upright by heating the projections slightly and standing it on the carbon plate mentioned on page 7. After the foot is adjusted it should be annealed slightly by heating to just below the softening point of the glass and then rotating in a smoky gas flame until it is covered with a deposit of carbon, after which it should be allowed to cool in a place free from draughts and where the hot glass will not come in contact with anything. The finished foot is shown by _k_, Fig. 7. _Building up from Glass Rod._--A glass skeleton-work can be constructed from rod without much difficulty, and is sometimes useful as a container for a substance which has to be treated with acid, or for similar purposes. The method is almost sufficiently explained by the illustration in Fig. 7; _f_ shows the initial stage, _g_ the method of construction of the net-work, and _h_ the finished container. It is convenient to introduce the substance at the stage indicated by _g_. The important points to observe in making this contrivance are that the glass rod must be kept hot by working while it is actually in the flame, and that the skeleton must be made as thin as possible with the avoidance of heavy masses of glass at any place. If these details are neglected it will be almost certain to crack. _Stirrers._--These are usually made from glass rod, and no special instructions are necessary for their construction, except that the glass should be in a thoroughly fused condition before making any joins and the finished join should be annealed slightly by covering with a deposit of soot, as explained on page 16. The flat ends shown in _a_, Fig. 8, are made by squeezing the soft glass rod between two pieces of carbon, and should be re-heated to dull redness after shaping. Fig. 8 also shows various forms of stirrer. In order to carry out stirring operations in the presence of a gas or mixture of gases other than air, some form of gland or seal may be necessary where the stirrer passes through the bearing in which it runs. A flask to which is fitted a stirrer and gas seal is shown in section by _b_, Fig. 8. The liquid used in this seal may be mercury, petroleum, or any other that the experimental conditions indicate. [Illustration: Fig. 8] If the bearing for a stirrer is made of glass tube, it is desirable to lubricate rather freely; otherwise heat will be produced by the friction of the stirrer and the tube will probably crack. Such lubrication may be supplied by turning out the top of the bearing tube and filling the turned-out portion with petroleum jelly mixed with a small quantity of finely ground or, better, colloidal graphite, and the bearing should also be lubricated with the same composition. Care should be taken not to employ so soft a lubricant or so large an excess as to cause it to run down the stirrer into the liquid which is being stirred. _Leading a Crack._--It sometimes happens that a large bulb or specially thin-walled tube has to be divided. In such a case it is scarcely practicable to use the method recommended for small tubes on page 12, but it is quite easy to lead a crack in any desired direction. A convenient starting point is a file cut; this is touched with hot glass until a crack is initiated. A small flame or a bead of hot glass is now used to heat the article at a point about a quarter of an inch from the end of the crack and in whatever direction it has to be led. The crack will now extend towards the source of heat, which should be moved farther away as the crack advances. In this manner a crack may be caused to take any desired path and can be led round a large bulb. _Cutting Glass with the Diamond._--Slips of window-glass can be used in place of glass rod for some purposes, and as cutting them involves the use of the glaziers' diamond or a wheel-cutter, they may well be mentioned under this heading. In cutting a sheet of glass with the diamond, one needs a flat surface on which to rest the glass, and a rule against which to guide the diamond. The diamond should be held in an almost vertical position, and drawn over the surface of the glass with slight pressure. While this is being done the angle of the diamond should be changed by bringing the top of the handle forward until the sound changes from one of scratching to a clear singing note. When this happens the diamond is cutting. A few trials will teach the student the correct angle for the diamond with which he works, and the glass, if properly cut, will break easily. If the cut fails it is better to turn the glass over and make a corresponding cut on the other side rather than make any attempt to improve the original cut. The diamond is seldom used for cutting small glass tubes. The use of the wheel-cutter calls for no special mention as it will cut at any angle, although the pressure required is somewhat greater than that needed by most diamonds. CHAPTER III Internal Seals, Air-Traps, Spray Arresters, Filter-Pumps--Sprays, Condensers; Plain, Double Surface, and Spherical--Soxhlet Tubes and Fat Extraction Apparatus--Vacuum Tubes, Electrode Work, Enclosed Thermometers, Alarm Thermometers, Recording Thermometers, "Spinning" Glass. _Internal Seals._--It is convenient to class those cases in which a glass tube passes through the wall of another tube or bulb under the heading of "Internal Seals." These are met with in barometers, spray arresters, and filter pumps, in condensers and some forms of vacuum tube. The two principal methods of making such seals will be considered first and their special application afterwards. _An Air Trap on a Barometer Tube._--This involves the use of the first method, and is perhaps the simplest example that can be given. Fig. 9, _a_, _a1_ and _a2_, show the stages by which this form of internal seal is made. For the first trials, it is well to work with fairly thick-walled tubing, which should be cut into two pieces, each being about eight inches long. [Illustration: Fig. 9] First seal the end of one tube as described on page 13, heat the sealed end and expand to a thick walled bulb. Fuse the end of the other tube, attach a piece of glass rod to serve as a handle, and draw out; cut off the drawn-out portion: leaving an end like _a_. Now heat a small spot at the end of the bulb, blow, burst out, and remove the thin fragments of glass. Heat a zone on the other tube at the point where the drawn-out portion commences and expand as shown by _a1_. The next stage is to join the tubes. Heat the ragged edges of the burst-out portion until they are thoroughly rounded. At the same time heat the drawn-out tube to just below softening point. Then, while the rounded edges of the burst-out portion are still soft, insert the other tube; rotate the join in the blowpipe flame until it is quite soft, and expand by blowing. If necessary, re-heat and expand again. The finished seal, which should be slightly annealed by smoking in a sooty flame, is shown by _a2_. _A Spray Arrester._--This is made by the second method, in which the piece of tube which projects inside the bulb is fused in position first and the outer tube is then joined on. The various stages of making are illustrated by _b_, _b1_ and _b2_, Fig. 9. A bulb is blown between two tubes by the method given on page 22, the larger tube is then cut off and the small piece of tube introduced into the bulb after having been shaped as shown in by _b_, Fig. 9. The opening in the bulb is sealed as shown by _b1_. The sealed part is now heated and the bulb inclined downwards until the inner tube comes in contact with the seal and is fused in position. This operation requires some practice in order to prevent the inner tube either falling through the soft glass or becoming unsymmetrical. The end of the bulb, where the inner tube comes in contact with it, is now perforated by heating and blowing, thus giving the form shown by _b2_, and the outer tube is joined on. The finished spray arrester is shown by _b3_. Practice alone will give the power to produce a symmetrical and stable piece of work. _Two Forms of Filter Pump._--That illustrated by _d_, Fig. 9, is made by the method explained under "An Air Trap on a Barometer Tube." That illustrated by _c_ is made by the method explained under "A Spray Arrester." No new manipulation is involved, and the construction should be clear from a study of the drawings. _Multiple and Branched Internal Seals._--A fuller consideration of these will be found on page 39, but one general principle may well be borne in mind; that, as far as is possible, a tube having both ends fastened inside another tube or bulb should be curved or have a spiral or bulb at some point in its length, otherwise any expansion or contraction will put great strain on the joints. _Sprays._--A spray which is easy to make, easy to adjust, and easy to clean after use is shown by _e_, Fig. 9. The opening on the top of the bulb is made by melting on a bead of glass, expanding, bursting, and fusing the ragged edges. The two branches which form the spray producing junction are made by the method used for an exhaustion branch and described on page 18. A spray which can be introduced through the neck of a bottle is shown by _h_, Fig. 9. The various stages in making this are illustrated by _f_, and _g_. If the inner tube is made by drawing out from a larger piece of glass so that two supporting pieces are left on each side of the place where it is intended to make the final bend, that bend can be made in a flat-flame gas burner without causing the inner tube to come in contact with the walls of the outer tube. Care must be taken when joining on the side piece that the inner tube is not heated enough to fuse it. The small hole in the side of the outer tube is produced by heating and bursting. _A Liebig's Condenser._--This consists of a straight glass tube passing through an outer cooling jacket. In practice it is better to make the jacket as a separate piece, and to effect a water-tight junction by means of two short rubber tubes. It may, however, be made with two internal seals of the class described under "A Spray Arrester." There is much less risk of these seals cracking if the inner tube is made in the form of a spiral or has a number of bulbs blown on it in order to give a certain amount of elasticity. _A Double-Surface Condenser._--Fig. 10 shows a condenser of this nature which is supplied by Messrs. Baird and Tatlock. It may be built up in stages as shown by _a_, _b_, and _c_, but the work involved requires considerable skill, and the majority of laboratory workers will find it cheaper to buy than to make. [Illustration: Fig. 10] _A Spherical Condenser._--Such a condenser as that shown by _f_, Fig 10, involves a method which may find application in a number of cases. The outer bulb is blown from a thick piece of tubing which has been inserted in a smaller piece (see _d_, Fig. 6); then the inner bulb by similar method. It is now necessary to introduce the smaller bulb into the larger, and for this purpose the larger bulb must be cut into halves. A small but deep cut is made with the file or glass-blowers' knife in the middle of the larger bulb, and at right angles to the axis of the tube on which it is blown. A minute bead of intensely heated glass is now brought in contact with the cut in order to start a crack. This crack may now be led round the bulb as described on page 30. If the work is carried out with care, it is possible to obtain the bulb in two halves as shown by _d_, and these two halves will correspond so exactly that when the cut edges are placed in contact they will be almost air-tight. The two tubes from the smaller bulb should be cut to such a length that they will just rest inside the larger, and the ends should be expanded. Place the inner bulb in position and fit the two halves of the outer bulb together, taking great care not to chip the edges. If the length of the tubes on the inner bulb has been adjusted properly, the inner bulb will be supported in position by their contact with the tubes on the outer bulb. Now rotate the cracked portion of the outer bulb in front of a blowpipe flame and press the halves together very gently as the glass softens. Expand slightly by blowing if necessary. If a small pin-hole develops at the joint it is sometimes possible to close this with a bead of hot glass; but if the bulb has been cut properly there should be no pin-holes formed. The condenser is finished by joining on the side tubes and sealing the inner tube through by the methods already given. In order to blow bulbs large enough to make a useful condenser, it will be convenient to employ the multiple-jet blowpipe described on page 4. _A Soxhlet-Tube or Extraction Apparatus._--This involves the construction of a re-entrant join where the syphon flows into the lower tube. It is of considerable value as an exercise and the complete apparatus is easy to make. A large tube is sealed at the bottom and the top is lipped, as in making a test-tube. A smaller tube is then joined on by a method similar to that given on page 18, but without making a perforation in the bottom of the large tube. Heating and expanding by air pressure, first through the large tube, then through the smaller tube and then again through the large tube, will give a satisfactory finish to this part of the work. [Illustration: Fig. 11] The syphon tube is now joined on to the large tube as shown by _a_, Fig. 11, care being taken to seal the other end of the syphon tube before joining. The details of the final and re-entrant joint of the syphon tube are shown at the lower part of _a_. This join is made by expanding the sealed end of the syphon tube into a small, thick-walled bulb, and the bottom of this bulb is burst out by local heating and blowing; the fragments of glass are removed and the edges made smooth by melting. A similar operation is carried out on the side of the tube to which the syphon tube is to be joined. This stage is shown by _a_. Now heat the syphon tube at the upper bend until it is flexible, and press the bulb at its end into the opening on the side of the other tube. Hold the glass thus until the syphon is no longer flexible. The final join is made by heating the two contacting surfaces, if necessary pressing the edges in contact with the end of a turn-pin, fusing together and expanding. The finished apparatus is shown by _c_. _Electrodes._--A thin platinum wire may be sealed into a capillary tube without any special precautions being necessary. The capillary tube may be drawn out from the side of a larger tube by heating a spot on the glass, touching with a glass rod and drawing the rod away; or the exhaustion branch described on page 18 may be used for the introduction of an electrode. It is convenient sometimes to carry out the exhaustion through the same tube that will afterwards serve for the electrode. The electrode wire is laid inside the branch before connecting to the exhaustion pump. When exhaustion is completed the tube is heated until the soft glass flows round the platinum and makes the seal air-tight. The branch is now cut off close to the seal on the pump side, a loop is made in the projecting end of the platinum wire, and the seal is finished by melting the cut-off end. Platinum is usually employed for such work, but if care is taken to avoid oxidation it is not impossible to make fairly satisfactory seals with clean iron or nickel wire. Hard rods of fine graphite, such as are used in some pencils, may also be sealed into glass, but it seems probable that air would diffuse through the graphite in the course of time. Another method for the introduction of an electrode is illustrated by _d_, _e_, _f_ and _g_, Fig. 11. In this case the bulb or thin-walled tube into which the electrode is to be sealed is perforated by a quick stab with an intensely heated wire--preferably of platinum--which is then withdrawn before the glass has had time to harden, and thus a minute circular hole is made. The electrode is coated with a layer of similar glass, or of the specially made enamel which is sold for this purpose, inserted into the bulb or tube by any convenient opening, and adjusted by careful shaking until the platinum wire projects through the small hole. The bulb or tube is then fused to the coating of the electrode and the whole spot expanded slightly by blowing. The appearance of the finished seal is shown by _g_. It is well to anneal slightly by smoking. _Thermometers._--Apart from the notes on page 20 with respect to the blowing of a suitable bulb on capillary tubing there is little to say in connection with the glass working needed in making a plain thermometer. The size desirable for the bulb will be determined by the bore of the capillary tube, the coefficient of expansion of the liquid used for filling, and the range of temperature for which the thermometer is intended. Filling may be carried out as follows:--Fit a small funnel to the open end of the capillary by means of a rubber tube, and pour into the funnel rather more than enough of the liquid to be used than is required to fill the bulb. Mercury or alcohol will be used in practice, most probably. Warm the bulb until a few air bubbles have escaped through the liquid and then allow to cool. This will suck a certain amount of liquid into the bulb. Now heat the bulb again, and at the same time heat the capillary tube over a second burner. The liquid will boil and sweep out the residual air, but it is necessary to heat the capillary tube as well in order to prevent condensation. Allow the bulb and tube to cool, then repeat the heating once more. By this time the bulb and tube should be free from air, and cooling should give a completely filled thermometer. Remove the funnel and heat the thermometer to a few degrees above the maximum temperature for which it is to be used; the mercury or other filling liquid will overflow from the top, and, as the temperature falls, will recede, thus allowing the end of the capillary to be drawn out. Reheat again until the liquid rises to the top of the tube, then seal by means of the blowpipe flame. The thermometer is now finished except for graduation; this is dealt with on page 75. _An Alarm Thermometer._--A thermometer which will complete an electric circuit when a certain temperature is reached may be made by sealing an electrode in the bulb and introducing a wire into the top, which in this case is not sealed. Naturally, this thermometer will be filled with mercury. There is considerable difficulty in filling such a bulb without causing it to crack. Several elaborations of this form are made, in which electrodes are sealed through the walls of the capillary tube, thus making it possible to detect electrically the variation of temperature when it exceeds any given limits. _An Enclosed or Floating Thermometer._--The construction of this type of thermometer is shown by _h_ and _i_, Fig 11. It is made in the following stages:--A bulb is blown on the drawn-out end of a thin-walled tube as shown by _h_. A small bulb is blown on the end of a capillary tube, burst, and turned out to form a lip which will rest in the drawn-out part of the thin-walled tube but is just too large to enter the bulb. The capillary tube is introduced and sealed in position, care being taken to expand the joint a little. The thermometer is filled and the top of the capillary tube closed by the use of a small blowpipe flame. A paper scale having the necessary graduations is inserted, and the top of the outer tube is closed as shown by _i_. _A Maximum and Minimum Thermometer._--If a small dumb-bell-shaped rod of glass or metal is introduced into the capillary tube of a horizontally placed, mercury-filled thermometer in such a position that the rising mercury column will come in contact with it, the rod will be pushed forward. When the mercury falls again the rod will be left behind and thus indicate the maximum temperature attained. If a similar dumb-bell-shaped rod is introduced into an alcohol-filled thermometer and pushed down until it is within the alcohol column, it will be drawn down by surface tension as the column falls; but the rising column will flow passed it without causing any displacement; thus the minimum temperature will be recorded. Six's combined maximum and minimum thermometer is shown by _b_, Fig. 11. In this case both maximum and minimum records are obtained from a mercury column, although the thermometer bulb is filled with alcohol. It is an advantage to make the dumb-bell-shaped rods of iron, as the thermometer can then be reset by the use of a small magnet, another advantage consequent on the use of metal being that the rods can be easily adjusted, by slight bending, so as to remain stationary in the tubes when the thermometer is hanging vertically, and yet to move with sufficient freedom to yield to the pressure of the recording column. The thermometer may be filled by the following method:--When the straight tube has been made the first dumb-bell is introduced and shaken down well towards the lower bulb, the tube is now bent to its final shape and the whole thermometer filled with alcohol as described on page 44. Now heat the thermometer to a little above the maximum temperature that it is intended to record, and pour clean mercury into the open bulb while holding the thermometer vertically. Allow to cool, and the mercury will be sucked down. The second dumb-bell is now introduced, sufficient alcohol being allowed to remain in the open bulb to about half fill it, and the alcohol in this bulb is boiled to expel air. The tube through which the bulb was filled in now sealed. _Clinical Thermometers._--The clinical thermometer is a maximum thermometer of a different type. In this case there is a constriction of the bore at a point just above the bulb. When the mercury in the bulb commences to contract, the mercury column breaks at the constriction and remains stationary in the tube, thus showing the maximum temperature to which it has risen. _Vacuum Tubes._--There are so many forms of these that it is scarcely practicable or desirable to give detailed instructions for making them; but an application of the various methods of glass-working which have already been explained should enable the student to construct most of the simpler varieties. An interesting vacuum tube is made which has no electrodes, but contains a quantity of mercury. When the tube is rocked so as to cause friction between the mercury and the glass sufficient charge is produced to cause the tube to glow. _A Sprengel Pump._--This, in its simplest form, is illustrated by _a_, Fig. 12. Such a form, although highly satisfactory in action, needs constant watching while in action, as should the mercury funnel become empty air will enter the exhausted vessel. Obviously, the fall-tube must be made not less than thirty inches long; the measurement being taken from the junction of the exhaustion branch with the fall-tube to the top of the turned-up end. [Illustration: Fig. 12] _A Macleod Pump._--One form of this is illustrated by _b_, Fig. 12. It has the advantage that the mercury reservoir may be allowed to become empty without affecting the vacuum in the vessel being exhausted. _"Spinning" Glass._--By the use of suitable appliances, it is quite possible to draw out a continuous thread of glass, which is so thin as to have almost the flexibility and apparent softness of woollen fibre; a mass of such threads constitutes the "glass wool" of commerce. The appliances necessary are:--a blowpipe capable of giving a well-formed flame of about six or eight inches in length, a wheel of from eighteen inches to three feet in diameter and having a flat rim of about three inches wide, and a device for rotating the wheel at a speed of about three hundred revolutions per minute. A very satisfactory arrangement may be made from an old bicycle; the back wheel having the tyre removed and a flat rim of tin fastened on in its place. The chain drive should be retained, but one of the cranks removed and a handle substituted for the remaining pedal. The whole device is shown by Fig. 13. [Illustration: Fig. 13] The procedure in "spinning" glass is as follows:--First melt the end of a glass rod and obtain a large mass of thoroughly softened glass, now spin the wheel at such a speed that its own momentum will keep it spinning for several seconds. Touch the end of the melted rod with another piece of glass and, without withdrawing the original rod from the blowpipe flame, draw out a thread of molten glass and twist it round the spinning wheel. If this is done properly, the thread of glass will grip on the flat rim, and by continuing to turn the wheel by hand it is possible to draw out a continuous thread from the melted rod, which must be advanced in the blowpipe flame as it is drawn on the wheel. If the rod is not advanced sufficiently the thread will melt off, if it is advanced too much, so as to heat the thick part and allow the glass to become too cool at the point of drawing out, then the thread will become too thick, but it is easy after a little practice to obtain the right conditions. Practice is necessary also in order to find the right speed for the wheel. When sufficient glass has been "spun," the whole "hank" of thin thread may be removed by drawing the thumb-nail across the wheel at any point on its flat rim, thus breaking the threads, and allowing the "hank" to open. _Brushes for Use with Strong Acids._--Glass wool, if of fine enough texture to be highly flexible, can be used to make acid-resisting brushes. A convenient method for mounting the spun glass is to melt the ends of the threads together into a bead, and then to fuse the bead on to a rod; thus giving a brush. If a pointed brush is necessary, the point may be ground on an ordinary grindstone or carborundum wheel by pressing the loose end of the spun glass against the grinding wheel with a thin piece of cardboard. When using brushes of this description, it is well to bear in mind the fact that there is always a liability of a few threads of glass breaking off during use. CHAPTER IV Glass, Its Composition and Characteristics. Annealing. Drilling, Grinding, and Shaping Glass by methods other than Fusion. Stopcocks. Marking Glass. Calibration and Graduation of Apparatus. Thermometers. Exhaustion of Apparatus. Joining Glass and Metal. Silvering Glass. There are three kinds of glass rod and tubing which are easily obtainable; these are soda-glass, which is that usually supplied by chemical apparatus dealers when no particular glass is specified; combustion-glass, which is supplied for work requiring a glass that does not so easily soften or fuse as soda-glass; and lead-glass, which is less common. There are also resistance-glass, made for use where very slight solubility in water or other solutions is desirable, and a number of other special glasses; but of these soda-glass, combustion-glass, lead-glass, and resistance-glass are the most important to the glass-blower whose work is connected with laboratory needs. _Soda-Glass._--Consists chiefly of sodium silicate, but contains smaller quantities of aluminum silicate, and often of calcium silicate; there may also be traces of several other compounds. The ordinary soda-glass tubing melts easily in the blowpipe flame, it has not a long intermediate or viscous stage during fusion, but becomes highly fluid rather suddenly; it does not blacken in the reducing flame. Bad soda-glass or that which has been kept for many years, tends to devitrify when worked. That is to say the glass becomes more or less crystalline and infusible while it is in the flame; and in this case it is often impossible to do good work with that particular sample of glass; although the devitrification may sometimes be remedied by heating the devitrified glass to a higher temperature. The presence of aluminum compounds appears to have some influence on the tendency of the glass to resist devitrification. Soda-glass, as a rule, is more liable to crack by sudden heating than lead-glass, and articles made from soda-glass often tend to crack spontaneously if badly made or, in the case of heavier and thicker articles, if insufficiently annealed. _Combustion-Glass._--Is usually a glass containing more calcium silicate and potassium silicate than the ordinary "soft" soda-glass. It is much less fusible than ordinary soda-glass, and passes through a longer intermediate or viscous stage when heated. Such a glass is not very suitable for use with the blowpipe owing to the difficulty experienced in obtaining a sufficiently high temperature. If, however, a certain amount of oxygen is mixed with the air used in producing the blowpipe flame this difficulty is minimised. _Resistance-Glass._--May contain zinc, magnesium, and other substances. As a rule it is harder than ordinary soda-glass, and less suitable for working in the blowpipe flame. It should have very little tendency to dissolve in water, and hence is used when traces of alkali or silicates would prove injurious in the solutions for which the glass vessels are to be used. _Lead-Glass._--This, or "flint" glass as it is often called from the fact that silica in the form of crushed and calcined flint was often used in making the English lead-glasses, contains a considerable proportion of lead silicate. Such a glass has, usually, a particularly bright appearance, a high refractive index, and is specially suitable for the production of the heavy "cut-glass" ware. Lead-glass tubing is easy to work in the blowpipe flame, melts easily, but does not become fluid quite so suddenly as most soda-glasses; articles made from it are remarkably stable and free from tendency to spontaneous cracking, although, as is essential for all the heavy or "glass-house" work, the massive articles need annealing in the oven. The two chief disadvantages of lead-glass for laboratory work are that it is blackened by the reducing gases if held too near to the blue cone of the blowpipe flame, and that it is rather easily attacked by chemical reagents; thus ammonium sulphide will cause blackening. The effect of the reducing flame on lead is not altogether a disadvantage, however; because a little care in adjusting the blowpipe and a little care in holding the glass in the right position will enable the student to work lead-glass without producing the faintest trace of blackening. This, in addition to being a valuable exercise in manipulation, will teach him to keep his blowpipe in good order, and prove a useful aid in his early efforts to judge as to the condition of the flame. It prevents discouragement if the student does his preliminary work with the soda-glass, but he should certainly make experiments with lead-glass as soon as he has acquired reasonable dexterity with soda-glass. _Annealing._--Annealing is a process by which any condition of strain which has been set up in a glass article, either by rapid cooling of one part while another part still remains hot, or by the application of mechanical stress after cooling is relieved. Annealing is carried out by subjecting the article to a temperature just below the softening point of the glass, maintaining that temperature until the whole article has become heated through the thicker part, and then reducing the temperature very gradually; thus avoiding any marked cooling of the thinner and outer parts first. For thin glass apparatus of the lamp-blown or blowpipe-made variety in which there are no marked difference of thickness, such as joins on tubes, ordinary seals, bulbs, etc., there is little need for annealing; and even those having rather marked changes of thickness, such as filter pumps, can be annealed sufficiently by taking care that the last step in making is heating to just below visible redness in the blowpipe flame and then rotating in a sooty gas flame until covered with a deposit of carbon. The article should then be allowed to cool in a place free from draughts and where the hot glass will not come in contact with anything. A few of the blowpipe-made articles, such, for example, as glass stopcocks, need more careful annealing, and for this purpose a small sheet-iron oven which can be heated to dull redness over a collection of gas burners will serve. Better still, a small clay muffle can be used. In either case, the article to be annealed should be laid on a clean, smooth, fireclay surface, the temperature should be maintained at a very dull red for two or three hours and then reduced steadily until the oven is cold. This cooling should take anything from three to twelve hours, according to the nature of the article to be annealed. A thick article, or one having great irregularities in thickness will need much longer annealing than one thinner or more regular. As a rule, soda-glass will need more annealing than lead-glass. _Drilling Glass._--Small holes may be drilled in glass by means of a rod of hard steel which has been broken off, thus giving a more or less irregular and crystalline end. There are several conditions necessary to enable the drilling of small holes to be carried out successfully:--the first of these is that the "drill" should be driven at a high speed. This may be done by means of a geared hand-drill such as the American pattern drill, although a somewhat higher speed than this will give is even more satisfactory. The second condition is that the pressure on the drill is neither too light nor too heavy; this is conveniently regulated by hand. The third condition is that the drill be prevented from "straying" over the surface of the glass; for this purpose a small metal guide is useful. The fourth condition is that a suitable lubricant be used; a strong solution of camphor in oil of turpentine is perhaps the most suitable. For commercial work, a diamond drill is often used, but this is scarcely necessary for the occasional work of a laboratory. _Larger Holes in Glass._--The method of drilling with a hard steel rod is not highly satisfactory for anything but small holes. When a larger hole, say one of an eighth of an inch or more, is needed it is better to use a copper or brass tube. This tube may be held in an American hand-drill, but a mixture of carborundum or emery and water is supplied to the rotating end. Tube or drill must be lifted at frequent intervals in order to allow a fresh supply of the grinding material to reach the end. In this case, also, a guide is quite essential in the early stages of drilling; otherwise the end of the tube will stray. The speed of cutting may be increased slightly by making a number of radial slots in the end of the tube; these serve to hold a supply of the grinding material. _Grinding Lenses._--This is scarcely within the scope of a book on glass-blowing for laboratory purposes, but it may be said that the lens may be ground by means of a permutating mould of hard lead or type-metal. The rough shaping is done with coarse carborundum or emery, and successive stages are carried on with finer and finer material. The last polishing is by the use of jewellers' rouge on the mould, now lined with a fine textile. _Filing Glass._--If a new file, thoroughly lubricated with a solution of camphor in oil of turpentine, is used, there is but little difficulty in filing the softer glasses. A slow movement of the file, without excessive pressure but without allowing the file to slip, is desirable. After a time the cutting edges of the file teeth will wear down and it will be necessary to replace the file by another. _Grinding Stoppers._--This is, perhaps, the most common form of grinding that the laboratory worker will need to perform, and for that reason, rather full details of the procedure are desirable. A very crude form of ground-in stopper may be made by drawing out the neck and the mass of glass which is intended to form the stopper to approximately corresponding angles, wetting the surfaces with a mixture of the abrasive material and water, and grinding the stopper in by hand. Frequent lifting of the stopper is necessary during grinding, in order to allow fresh supplies of abrasive material to reach the contacts. When an approximate fit is obtained, the coarse abrasive should be washed off, care being taken that the washing is complete, and a finer abrasive substituted. After a while, this is replaced in its turn by a still finer grinding material. Such a method of grinding may give a satisfactory stoppering if the angles of the plug and socket correspond very closely before grinding is commenced; but if there is a wide difference in the original angles, then no amount of grinding by this method will produce a good result. The reason for this is that the plug will become so worn in the preliminary grinding as to assume the form of a highly truncated cone; the socket will assume a reverse form, and the end result will be a loose-fitting plug and socket. Satisfactory grinding may be carried out by the use of copper or type-metal cones for the preliminary shaping. Such cones should be mounted on a mandrel which will fit into the chuck of the American hand-drill and turned on the lathe to the desirable angle for stoppering. A number of these cones will be necessary. A number of similar moulds, that is to say blocks of type-metal or hard lead in which is a hole corresponding in size and angle to the plug desired, should be made also. These must be rotated, either in the lathe or by other means, and are used for the preliminary shaping of the plug. If but few plugs are to be ground it is unnecessary to provide a means of rotating the moulds, as the plug may be held in the hand and ground into the mould in a manner similar to that used in the first method of stoppering. [Illustration: Fig. 14] When the socket and plug have been ground, by the successive use of cones and moulds, to the desired angle, so that they correspond almost exactly, the plug is given its final fitting into the socket by grinding-in with a fine abrasive, in the manner first described. _Stopcocks._--Although it would be more strictly in keeping with the form of this book to divide the making of stopcocks into two parts; shaping by heat and grinding, we will consider the whole operation here, and take for our example a simple stopcock such as that illustrated by Fig. 14. The "blank," _f_, that is the socket before grinding, is made by drawing out a piece of fairly thick-walled tubing into the form shown by _a_. Two zones on this tube are then heated by means of a small, pointed flame, and the tube is compressed along its axis, thus producing two raised rings as shown by _b_. Two zones, slightly towards the outer sides of these two raised rings are heated and the tube is drawn while air pressure is maintained within. This produces two thin-walled bulbs or extensions similar to those shown by _c_. One of these extensions is now broken off by means of a sharp blow with the edge of a file or other piece of metal, and the edges of the broken glass are rounded in the flame. The other extension is left to serve as a handle. We have now a piece of glass like that shown by _d_. Now heat a spot on the side of this, medially between the raised rings, until the glass is on the point of becoming deformed, and bring the intensely heated end of a smaller tube in contact with the heated spot. Without disturbing the relative positions of the two tubes, press the smaller tube down on a thin steel wire, so that the wire passes along the tube and enters the soft glass; thus forming a projection inside the sockets as shown by _e_. The wire must be withdrawn, again immediately. When the wire has been withdrawn, heat the place where it entered to dull redness, in order to relieve any strain; break off the thin extension, which up to the present has served as a handle, round off the broken edges in the flame, and join on and indent a similar piece of small tubing to the opposite side of the socket; the socket at this stage being shown by _f_. The "blank" for the socket is now completed, but it must be heated to dull redness in order to relieve strain and be placed in an annealing oven, where it should be annealed for some hours. The "blank" for the plug offers no special difficulty; it is made by heating a glass rod and compressing it axially until a mass having the form shown by _g_, Fig. 14, is produced; the end of this is heated intensely and brought in contact with the rather less heated side of a glass tube which has been drawn to the shape desired for the handle; when contact is made a slight air pressure is maintained in the glass tube, thus producing a hollow join. The ends of the tube are sealed and the bottom of the plug is drawn off, thus giving the finished "blank" as shown by _h_. This blank is now held in a pair of asbestos-covered tongs, heated to dull redness all over, and transferred to the annealing oven. When cold, the socket is ground out by the second method given under "Grinding Stoppers"; that is to say, by means of type-metal or copper cone, and the plug is ground to fit in a corresponding mould. When the fit is almost perfect, the transverse hole is drilled in the plug, and the final finishing is made with fine abrasive powder. Great care must be taken in the final grinding that there is no accumulation of abrasive material in the transverse hole of the plug; if this is allowed to occur there will be a ring ground out of the socket where the holes move, and the tightness of the finished stopcock will be lost. _Marking Glass._--As a preliminary to a consideration of the methods of graduating and calibrating glass apparatus, it is convenient to consider the various methods which are available for marking glass. Among these are, the writing diamond, the carborundum or abrasive pencil, the cutting-wheel, and etching by means of hydrofluoric acid. Each produces a different class of marking and each is worthy of independent consideration. _The Writing Diamond._--This is the name given to a small irregular fragment of "bort" which is usually mounted in a thin brass rod. Such a diamond, if properly selected, has none of the characteristics of a cutting diamond; although one occasionally finds so-called "writing diamonds" which will produce a definite cut. These should be rejected. The writing diamond is used in much the same way as a pencil, but is held more perpendicularly to the object, and a certain amount of pressure is necessary. The mark produced is a thin scratch which, although fairly definite, lacks breadth, and this is a disadvantage where the marking has to be read at a distance. This disadvantage may to some extent be overcome by making a number of parallel scratches. _The Abrasive Pencil._--A rod of carborundum composition may be ground or filed to a point, and this forms a very useful pencil for general work. The marking produced is rather less definite than that produced by a writing diamond, but has the advantage of being broader. _The Cutting Wheel._--"Cutting" in this case is scarcely the ideal expression, it should rather be "grinding," but "cutting" is more commonly used. Exceedingly good graduations may be made by the edge of a small, thin, abrasive wheel which is mounted on the end of a small mandrel and driven by a flexible shaft from an electric motor or any other convenient source of power. The depth of the mark can be controlled, and very light pressure will suffice. _Etching._--This is often the quickest and easiest way of marking glass apparatus. The object to be marked should first be warmed and coated very thoroughly with a thin film of paraffin wax. When cold, the marking is made through the paraffin wax by means of a needle point, and the object is then exposed to the action of hydrofluoric acid. If a shallow but clearly visible marking is desired, it is well to use the vapour of the acid; this may be done by bending up a sheet-lead trough on which the object can rest with the marked surface downwards. A little of the commercial hydrofluoric acid, or a mixture of a fluoride and sulphuric acid, is distributed over the bottom of the trough, and the whole arrangement is allowed to stand for about an hour. The object is washed thoroughly and the paraffin wax removed, either by melting and wiping off or by the use of a solvent, and the marking is finished. If a deep marking is desired, in order that it may afterwards be filled with some pigment, a better result is obtained by the use of liquid commercial hydrofluoric acid, which is a solution of hydrogen fluoride in water. The acid is mopped on to the object after the markings have been made on the paraffin wax film, and allowed to remain in contact for a few minutes. It is advantageous to repeat the mopping-on process at intervals during the etching. In all cases where hydrofluoric acid is used, or stored, it is of great importance to keep it well away from any optical instruments, as the most minute trace of vapour in the air will produce a highly destructive corrosion of any glass surfaces. _Methods of Calibration._--In the case of apparatus for volumetric work, this is usually carried out by weighing, although some of the smaller subdivisions are often made by measurement. When the subdivisions are made in this way it is of importance to see that the walls of the tube or vessel to be calibrated are parallel. Great errors arise in some of the commercial apparatus from neglect of this precaution. A convenient method of testing for parallelism, in the case of a wide tube, is to close one end and to weigh in successive quantities of mercury. An observation of the length occupied by each successive quantity will indicate any change in the bore. In the case of capillary tubes, it is convenient to introduce an unweighed quantity of mercury, measure its length accurately, and then to move it along the tube in stages, either by tilting the tube or by the application of air pressure. A measurement of the length at each stage will indicate whether the bore is approximately parallel or not. Neither of these methods is to be relied on without a careful examination of the tube, as it may happen that there are local irregularities in the bore which compensate for each other, and do not, therefore, affect the volume of a given length. Obviously, the smaller the quantity of mercury with which the test is carried out and the greater the number of observations made, the less risk will there be of such an error. A liquid, such as water or alcohol, which wets the glass is not suitable for such a test, unless special precautions are taken. When, however, a pipette or burette has to be calibrated to deliver a certain volume of water, the final calibration must be made with this liquid. Thus, the burette would first be calibrated by weighing in definite quantities of mercury of say 13.54 grammes (1 cc at 15°C.), each of the 1 cc divisions should be marked by some temporary marking. The burette is now filled with a solution of potassium bichromate and sulphuric acid and allowed to soak for some time; the bichromate is washed out and distilled water is put in. Successive quantities of water are run out of the jet, a fixed time being allowed for draining, and the weights of the quantities delivered are noted. This procedure will give the necessary data for altering the marking so that it may correspond to 1 cc _delivered_. Each 1 cc division is now divided into tenths by the method described below. A final verification of the markings should be made when the subdivision is completed. _Subdivision of Graduations._--Mark out the spaces to be subdivided on a sheet of paper. Take a reliable ruler on which any convenient length is divided into the desired number and place it across the lines at such an angle that the limits noted on the rule exactly bridge the gap. Now draw parallel lines through the markings. _Copying a Scale._--When a scale has been prepared on paper and it is necessary to copy that scale on the waxed-glass surface for etching, a convenient method is to employ a long wooden bar having a sharp needle passing through it at either end. The scale and object to be marked are fastened in line with one another, and the caliper bar is used from step to step. The mark is made by moving the bar through a minute portion of a circle, which provided that the bar is two or three feet in length, will not introduce any perceptible error in a scale of say a quarter of an inch in width. The arrangement is shown by Fig. 15. [Illustration: Fig. 15] _Graduating a Thermometer._--Assuming that the thermometer has been made of carefully selected tubing in which the bore is parallel and free from any small irregularities, we have only to fix the freezing point and boiling point. The intervening space may then be divided into 100 (if the thermometer is to be Centigrade) or 180 (if Fahrenheit). This division may be carried out by the method given under "Subdivisions of Graduations." A thermometer should not be calibrated until some weeks after making, as the glass bulb tends to contract. _Joining Glass and Metal._--It sometimes happens that one needs to make a more permanent and less flexible joint between a glass and metal tube than can be obtained by means of a rubber tube. To this end, any one of three slightly different methods may be employed. In the method of Chatelier one first coats the glass with platinum or silver, which may be done by moistening the glass with platinum chloride or silver nitrate and then heating to redness; a layer of copper is then deposited electrolytically on the treated surface of the glass, and soldering is carried out in the usual manner. McKelvy and Taylor call attention to two other methods in the _Journal of the Chemical Society_ for September, 1920. In one of these methods the glass is coated with platinum by covering it with a suspension of platinum chloride in oil of lavender and heating until the oil is burnt off. The metal tube is then tinned on its inner side and soldered to the prepared glass, slightly acid zinc chloride being used as a flux. In the second method, a joint is made by means of the Kraus flux, which consists of equal weights of zinc oxide, borax, and powdered soda-glass fused together. This is coated on the inner surface of the metal tube, and the hot glass tube, which has had the end slightly flanged to give support, is inserted. Fusion of the flux is completed by heating the outside of metal tube. _Silvering Glass._--In all cases where it is intended to deposit a silver mirror on a glass surface, thorough cleaning is essential. Prolonged soaking in a hot solution of potassium bichromate which has been acidified with sulphuric acid will often prove useful. The glass should then be washed thoroughly, rinsed in distilled water, and the solution should then be used. There are many formulæ for the silvering solution, but that used in Martin's method may be given:-- A--Nitrate of Silver 40 grammes Distilled Water 1000 c. cm. B--Nitrate of Ammonium 60 grammes Distilled Water 1000 c. cm. C--Pure Caustic Potash 100 grammes Distilled Water 1000 c. cm. D--Pure Sugar Candy 100 grammes Distilled Water 1000 c. cm. Dissolve and add:-- Tartaric Acid 23 grammes Boil for ten minutes, and when cool add:-- Alcohol 200 c. cm. Distilled Water to 2000 c. cm. For use take equal parts of A and B. Mix together also equal parts of C and D in another vessel. Then mix both liquids together in the silvering vessel and suspend the glass to be silvered face downwards in the solution. Or if a vessel has to be silvered on the inside, the solution is poured in. In this case, the deposition of silver may be hastened by immersing the vessel to be silvered in warm water. In working with a silver solution containing ammonia or ammonium salts there is sometimes the possibility of forming an explosive silver compound. It is well, therefore, to avoid keeping such solutions longer than is necessary, and to bear in mind that any deposit formed by solutions containing both silver and ammonia may have explosive properties, especially when dry. CHAPTER V Extemporised Glass-Blowing Apparatus--The Use of Oil or other Fuels--Making Small Rods and Tubes from Glass Scrap--The Examination of Manufactured Apparatus with the View to Discovering the Methods Used in Manufacture--Summary of Conditions Necessary for Successful Glass-Blowing. If, in the early stages of his study of glass-blowing, the student should attempt to work with the very simplest appliances, it is probable that his progress will be hindered; the use of the apparatus will require an undue amount of care and his attention will be distracted from the actual manipulation of the glass. The case is widely different after he has acquired a certain facility in glass-blowing. _A Simple Form of Blowpipe._--Although there are even more simple forms than that described here, we are not concerned with them. The form described is the simplest with which any considerable amount of glass-blowing can be carried out with certainty. This form consists of a tube through which air may be blown with the mouth, a condensation chamber in which any moisture from the breath can condense, a blowpipe jet, a supporting piece and a source of flame. The tube, condensation chamber, and jet are combined in the ordinary Black's blowpipe, such as is used for blowpipe tests in qualitative analysis; it consists of a conical tin tube having a mouthpiece at the small end and a side tube which carries a brass jet. A support for such a blowpipe may be cut out of a piece of brass or tin-plate, and should be fastened to a small, flat, wooden board. A source of flame may consist of an ordinary brass elbow, such as is used on gas fittings, and into which a piece of thin brass tube (the body of a fish-tail burner from which the perforated non-metallic plug has been removed will serve quite well) has been fitted. It is an advantage to flatten the brass tube somewhat and to file the flattened end to a slope which corresponds with the angle at which the blowpipe jet enters the burner. The whole source of the flame should be mounted on a separate base, in order that it may be moved while adjusting the apparatus to the best relative positions of flame and blowpipe jet. The complete apparatus is shown by _a_, Fig. 16. [Illustration: Fig. 16] In order to take full advantage of this blowpipe, it is desirable that the student should learn to maintain a steady steam of air with his mouth and, at the same time, be able to breathe. This requires a little practice. As a first exercise in breathing, before trying to breathe while using the mouth blowpipe, the student should close his mouth and inflate his cheeks with air; now, still keeping his cheeks tightly inflated, he should attempt to breathe through the nose. At first, this may be found rather difficult, but it becomes remarkably easy after a little practice. When he has mastered this, the student may practise the same operation, but with the blowpipe. It is important to bear in mind that the cheeks, not the lungs, form the reservoir for air used in maintaining the blowpipe flame. After a while, the student will find that he can maintain a steady air pressure and yet breathe with complete comfort. In adjusting the flame, care should be taken not to blow so hard as to produce a ragged and noisy cone of fire. A small jet, such as that commonly used on a mouth blowpipe, will with care give a pointed and quiet flame, having an appearance similar to that shown in the illustration. With a blowpipe like this, it is quite easy to seal glass tubes up to an inch in diameter, to join tubes up to half an inch in diameter, to bend tubes, to blow small bulbs, and to make the simpler forms of internal seal; but the provision for condensation of moisture is not ideal, and prolonged use of such a blowpipe also tends to produce undue fatigue. _A Mouth Blowpipe With an Expanding Reservoir._--This form of blowpipe can be made to give most excellent results; it is highly portable, and does not produce nearly so much fatigue when used continuously as the blowpipe described in the last section. Various slight modifications have been made in its construction during the last eighty years, but that described below will be found quite satisfactory. The apparatus consists of a tube through which air is blown from the mouth, a valve through which the air passes into an expanding reservoir, and a blowpipe jet in communication with the reservoir. In making the valve, several essentials have to be remembered; it must allow a free passage of air into the reservoir, it must open easily, and must close quickly. A satisfactory form of valve is that shown by _b_, Fig. 16. The moving part consists of a light glass bulb of about three-eights of an inch diameter and having a glass stem of rather under one-eighth diameter and about an inch and a half long. This stem rests in a guide at the end of a brass tube, the bulb contacting against the other end which is approximately shaped. The bulb and its seating are ground air-tight. A very light spring holds the bulb in position. This valve is fitted into a metal or glass T piece, one limb of which leads to the air reservoir and the other limb leads to the blowpipe jet; the limb containing the valve leads to the tube through which the air is blown in. A convenient reservoir may be made from a fairly large football bladder. A network of string should be fitted over the outside of the bladder and the strings should terminate in a hook on which a weight can be hung, in order to provide a means of adjusting the pressure at which the air is delivered to the jet. This bladder should be washed out and allowed to drain after use. The air tube which passes from the valve to the mouth may conveniently be made of brass, but, in order to avoid the continued contact of metal with the lips of the operator, it should be fitted with a non-metallic mouthpiece. It is an advantage from the point of view of portability to have the air tube easily detachable from the T piece containing the valve. The blowpipe jets, of which there may be several with advantage, may be made of glass tubing, bent to the most convenient angle and having an enlargement or bulb at some point in the tube. This bulb serves as a final condensing place for any traces of moisture that may escape from the larger reservoir. The whole device, blowing tube, reservoir, and T piece may be fastened to a clamp, so that it can be secured on the edge of any table where blowpipe work is to be carried out. If the blowpipe is to be used with gas, the form of burner described under. "A Simple Form of Blowpipe" will be found quite satisfactory. _The Use of Oil, or Other Non-Gaseous Fuels._--Although gas, when available, is usually preferred on account of its convenience, there are several other fuels which give a hotter flame. They have, also, the additional advantage of not requiring any connecting pipes; but each has its own disadvantage. One liquid fuel deserves special mention as being rather less desirable than the others; this is alcohol. Although very convenient in use, it has the disadvantage of being rather too highly inflammable and capable of burning without a wick, thus involving a certain fire risk; the flame is scarcely visible in a bright light, and the heat given by either the ordinary flame or the blowpipe flame produced from alcohol is considerably less than that from a similar flame in which coal gas is used. For small work, however, the facility with which a spirit lamp may be lighted may more than counterbalance these disadvantages at times. _Paraffin Wax._--Where there is no coal gas available and the blowpipe is only required at intervals, and especially where high portability is required, there are few fuels so convenient as paraffin wax. This may be obtained in pieces of a satisfactory size by cutting paraffin candles, from which the wick has been withdrawn, into lengths of about half an inch. These cut pieces have the advantage over any oily fuel, such as colza oil, that they can be wrapped in paper or carried in a cardboard box; further they will keep indefinitely, even in the presence of air, without undergoing any perceptible change. _Forms of Lamp for Paraffin Wax._--Probably, the best form is that devised by Thomas Bolas, and described by him in the _Journal of the Society of Arts_, December 2nd, 1898. This lamp consists of a small open tray of iron, through which pass three or more flat tubes, and between these tubes are placed small flat pieces of wick, the fit being such that the pieces of wick may be adjusted easily by means of a pair of pointed tweezers. The flame thus obtained, instead of having one large hollow, is broken or divided so that the combustion is concentrated into a smaller area, and the air blast, which is directed across the flame, carries the flame with it in a more complete manner than is the case with the ordinary flame; a more thorough combustion being realised by this arrangement. Another advantage is the ease with which the wick may be changed and a larger or smaller wick inserted to suit the flame to any size of air jet. This form of lamp may be used for oily fuel, although it is specially suitable for paraffin wax. Two small pieces of bent tin-plate may be used as side covers, and these serve to adjust the flame within certain limits. A tin-plate cover which fits easily over the whole lamp serves as an extinguisher. The complete lamp is shown by _d_, Fig. 16, and this figure shows also a quick-change air-jet device, the whole arrangement forming a blowpipe for use where a non-gaseous fuel is to be employed. Although the lamp just described is desirable when complete control over the size of the flame is necessary, and if the ideal conditions and maximum heat are to be obtained, yet a simpler form of lamp will be found to give very good results. Such a lamp may consist of a flat tin tray, having a diameter of about three and a half inches and a depth of about one inch. In this tray is a tin support for the wick, and the wick itself may consist of a bundle of soft cotton, for example, a loosely rolled piece of cotton cloth, but in either case the top of the wick should be cut to approximately the same angle as that at which the blowpipe jet meets the flame. In using paraffin wax as a fuel, it is necessary to see that sufficient wax reaches the wick to prevent charring during the first few minutes before the bulk of the wax is melted. _Animal and Vegetable Oils._--Almost any oil may be used as a fuel, but many tend to become hard and gummy if allowed to stand in the air for any considerable time. When this happens, the wick becomes clogged and it is impossible to obtain a good flame. A number of the oils tend, also, to produce rather strongly smelling smoke. _A Flame-Guard for Use With Non-Gaseous Fuels._--In order to avoid the eye-strain produced by the luminous base of the flame from a wick burning paraffin wax or oil, it is often advantageous to make a small tunnel of tin-plate, which can be rested on the sides of the lamp and rises over the top of the wick. Such a flame guard is shown by _e_, Fig. 16. _Small Rods and Tubes from Glass Scrap_:--It is scarcely practicable to make small quantities of good glass with the blowpipe flame as the only source of heat, but it is less difficult to make small rods or tubes from glass scrap, and the ability to do this is sometimes of considerable value when a small tube has to be joined on to some special piece of apparatus made of glass of unknown composition. It may be possible to obtain some fragments of similar glass, either from a broken part of the apparatus or from a similar piece, and from these fragments small tubes or rods can be made. The fragments of glass may be melted together on the end of a clay pipe-stem, care being taken to avoid trapping air bubbles as fresh fragments are added to the molten mass. When a sufficient quantity of glass has been accumulated, the viscous mass may be drawn out into a rod by bringing another pipe-stem into contact with the hot mass, rotating both pipe-stems steadily, and separating them until a rod of the desired size has been obtained. If, on the other hand, it is desired to produce a tube from the mass of heated glass, the mass should be blown hollow before the pipe-stems supporting it are separated. _Methods of Manufacture._--When the student has familiarised himself with the more common operations and processes used in glass-blowing, he will be in a position to increase his skill and knowledge of special methods by a critical examination of various examples of commercial work. There are few exercises more valuable than such an examination, combined with an attempt to reconstruct the stages and the methods by which the article chosen for examination was made. Obviously, it is impossible to give full details of all constructions in a small text-book; but it is easy to give an example of the constructional methods employed in the making of almost any piece of light blown-glass apparatus, and these methods should prove of special value when apparatus of a new pattern has to be evolved for the purposes of research. That is to say, one designs the apparatus required, applies known methods of construction as far as possible, and, by the examination of commercial apparatus having similar features, evolves the new methods required. For an exercise in such a process of reconstruction we may well take an ordinary commercial vacuum tube, such as that shown by _a_, Fig. 17. [Illustration: Fig. 17] In the tube from which this drawing was made, it was found that the spiral in the middle bulb was of a slightly yellowish colour and gave a green fluorescence when the electric discharge was passed through the tube; that is to say, the spiral is made of uranium-glass, which is usually a soda-glass containing trace of uranium, and hence differing slightly in composition from the ordinary glasses. The two enclosed tubes which are bent into a series of S bends gave a pink fluorescence, which indicates lead-glass; and the remainder of the tube fluoresced with an apple-green colour; this suggests ordinary soda-glass. We have, therefore, a piece of apparatus in which three dissimilar glasses are joined, while, at the same time, that apparatus contains a number of internal seals, and it is not probable that the dissimilar glasses will have their coefficients of expansion so nearly alike as to permit of a stable internal seal being made if one part of the seal consists of a glass differing from that of the other part. These considerations lead us to a closer examination of the joins where the dissimilar glasses are introduced, and we find that in no case is the internal seal made between dissimilar glasses, but that a soda-glass extension is joined on to both the uranium-glass tube and the lead-glass tubes at a point about half an inch before the internal seal commences. Careful examination of these joins shows that the change from one glass to another is not abrupt but gradual. Such a transitional joint may be made by taking a length of soda-glass tubing, sealing the end and fusing a minute bead of the other glass on to the sealed end, the end is then expanded and another bead of the other glass added, this bead is expanded and the operation is repeated, thus building up a tube, and, finally, the tube of the other glass is joined on to the end of this. We are now concerned with the question of the insertion of the uranium-glass spiral into the bulb (see p. 38). Obviously the spiral is too large to pass through the necks of the bulb, and it is difficult to imagine that the spiral was obtained by the insertion of a length of straight tubing which was bent after entering the bulb; therefore, the only remaining method is that the spiral was made first and the soda-glass extensions fastened on, and that the bulb was blown, cut in halves and the spiral inserted, and the two halves were then rejoined. That this was actually the case is confirmed by traces of a join which are just visible round the middle of the bulb. The insertion of the spiral and the making of the first internal seal are shown by _b_, and _c_. There is one detail in making the second join of the spiral to the bulb which calls for attention, and the small branch, similar to an exhaustion branch, at the side of the bulb provides a clue to this. If an attempt were made to complete the second internal seal through a closed bulb it would be impossible to obtain a good result, as the air-pressure in the bulb would not be under control when once union was effected, and further heating of the air in the bulb would cause expansion and perforate the wall near the second internal seal; we therefore make a small branch which can be left open and through which such air-pressure as may be found necessary can be maintained. The third join, by which the lead-glass tube is joined to the soda-glass is made in stages similar to those in which the soda-glass and uranium-glass were joined; but the internal seal is most conveniently made by sliding a length of tubing over the lead-glass and fusing this tubing to the large diameter soda-glass tube to which the lead-glass is already joined. The first stage of this operation is illustrated by _d_. When this seal is completed, the end of the soda-glass tube is drawn off and sealed as shown in _e_, and at this stage a side tube or branch is joined on. The sealed end of the outer and large diameter soda-glass tube is heated until it contracts and fuses to the enlargement that has previously been joined to the lead-glass tube, and the end is burst out as shown in _f_. Another length of soda-glass is then joined on to the burst-out end, and this length of soda-glass tubing is drawn out to a thin-walled contraction; the non-contracted part is expanded to form the bulb, and a small exhaustion branch made on the side, the drawn-out portion being cut off, and an electrode, previously prepared by coating a part of its length with a suitable enamel, is introduced. The tube is tilted to keep the electrode away from the drawn-out end, which is melted off and sealed. A small perforation is made with a hot platinum or iron wire in the sealed end, the electrode is shaken into position, and the sealing is completed as explained on page 42. The remainder of the tube, that is to say the lead-glass tube and the bulb on the other side of the middle bulb, is completed in a similar manner. SUMMARY OF CONDITIONS NECESSARY FOR SUCCESS IN GLASS-BLOWING. For the convenience of the student, it may be well to summarise the chief essentials for success in glass-blowing, and at the same time to add such brief notes on the various methods as may seem desirable. _Adjustment of Blowpipe._--The air jet should be clean internally, and so centered as to give a flame having a well-defined blue portion, the tip of the flame should not be only slightly luminous but purple in colour. In the case of a blowpipe burning oil or wax fuel the flame may be a trifle more ragged without disadvantage. _Bellows and Blowing._--The bellows should be adjusted to deliver air at constant pressure, either by insertion of a tap or, better, by attention to the wind reservoir if necessary. The movement of the foot in blowing should be steady, not jerky. _Heating Glass._--The tube or rod should be heated cautiously until it has reached its softening point in its thickest part. Steady rotation of the glass during the heating is almost essential. _Blowing a Bulb or Expanding a Join._--Prolonged heating is necessary in order that the thick parts may be heated completely through. Blowing should take place by stages, in order that the thin parts, which tend to expand first, have time to cool. The thick parts can then be expanded by further blowing and thus a bulb or expansion of even thickness can be obtained. _Cutting Glass._--The most useful method for general use is by means of the file or glass-blowers' knife. Either file or knife must be kept sharp by grinding. Neither file nor knife should be used on hot glass. The diamond and wheel cutter are useful for cutting sheet-glass, and when the diamond is employed a singing noise is an indication of a satisfactory cut. _Leading a Crack._--A crack may be led in any desired direction by means of a bead of hot glass or a small gas flame. The glass which it is desired to crack should be heated at a point slightly in advance of the crack, which will extend in the direction of the source of the heat. _Turning Out the End of a Tube._--This is done by heating the end of the tube and rotating it against an iron rod. The rod must be kept polished and free from rust, and it must not be allowed to become too hot while in use, otherwise the glass will stick to it. _Joining Unlike Glasses._--Joints between unlike glasses are often unstable. When such joints are made it is desirable to blow them as thin as possible, and to avoid the junction of unlike glasses in any complex joint, such as an internal seal. A transitional portion of tubing may be built up by the successive addition and interfusion of beads of one of the glasses to the end of a sealed tube consisting of the other glass. _Joining a Tube to a Very Thin Bulb._--The bulb may be thickened at the point of union by fusing on a bead of glass and expanding this slightly. A small central portion of the expanded part may then be perforated by bursting and the tube joined on. _Insertion of One Bulb Within Another._--A bulb may be divided into two halves by leading a crack round it and the inner bulb is then introduced. The two halves of the outer bulb may be fitted together (care being taken to avoid any damage to the edges), and the bulb may be completed by rotating the contacting edges before the blowpipe until they are soft, and then expanding slightly by means of air-pressure. _Annealing._--For most purposes, in the case of thin, blowpipe-made or lamp-blown glass apparatus, it is sufficient to cool slowly by rotating the finished article over a smoky flame and setting it aside in a place free from draughts, and where the hot glass will not come in contact with anything. Simple bulbs and joints do not even need this smoking; but thick articles, and especially those that are to be subjected to the stress of grinding, need more prolonged annealing in a special oven. _Use of Lead-Glass._--When lead-glass is to be used, the blowpipe flame should be in good adjustment and the glass should not be allowed to approach so near to the blue cone as to be blackened. Slight blackening may often be removed by heating the glass in the extreme end of the flame. Lead-glass articles tend to be rather more stable than similar articles of soda-glass. _Combustion-Glass._--This may be worked more easily if a small percentage of oxygen is introduced into the air with which the blowpipe flame is produced. If the air is replaced entirely by oxygen there is a risk of damaging the blowpipe jet, unless a special blowpipe is employed. _Internal Seal._--There are two ways of making these, one, in which the inner portion of the tube is fused on to the inside of the bulb or tube through which it is to pass, an opening is made by bursting and the outer tube is joined on. This is a quick and in some ways more satisfactory method than the other, in which there is no separate inner piece. _Rubber Blowing Tube._--In complicated work it is often convenient to use a thin rubber blowing-tube which is connected with the work either by a cork and piece of glass tubing or by fitting over a drawn-out end. The use of such a blowing-tube avoids the inconvenience of raising the work to the mouth when internal air-pressure is required. One end of the rubber tube is retained in the mouth during work. _General Notes._--A large amount of glass-blowing is spoiled through carelessness in arranging the work beforehand. The student should have every detail of his manipulation clearly in mind before he commences the work; he should not trust to evolving the method during the actual manipulation. Undue haste is another fruitful source of failure. Practically every operation in glass-blowing can be carried out in a perfectly leisurely manner, and it is better to err rather on the side of deliberation than on the side of haste. If, as will doubtless happen at times, a piece of work gives trouble and it is necessary to pause and consider the whole question, or if for any other reason it is necessary to stop during the construction of a partially finished join or other operation, great care should be taken not to allow the work to cool. A large, brush-like flame may be produced by increasing the amount of gas admitted to the blowpipe, and the work should be held just in front of the current of hot air produced by such a flame. It will then be possible to continue work on this without causing it to crack when further heat is applied. As time goes on, the student will find an increasing confidence in his ability to manipulate the soft glass, and with increasing confidence will come rapidly increasing power of manipulation. Perhaps the greatest obstacle to success in glass-blowing is undue haste in manipulation. INDEX Absorption bulbs, 21, 23. Airtube, flexible, 8, 102. Alarm thermometer, 45. Annealing, 7, 60. Bellows, adjusting pressure of, 5, 6. Bellows, foot, 5, 6. Bending tubes, 23. Blackening, 58, 101. Branching, 18, 19. Brushes of spun glass, 53. Blowpipe flame, quality of, 3. Blowpipe for mouth blast, 80, 82, 84. Blowpipe, for paraffin wax, 82, 88. Blowpipe, Herepath's, 2. Blowpipe jet, centring, 3, 98. Blowpipe jet, dirt in, 3. Blowpipe jet, multiple, 4, 40. Blowpipe, Letcher's, change, 4. Blowpipe, simple form of, 80. Bulb, medially on tube, 22. Bulbs, 19, 20, 22, 38, 98. Bulbs, absorption, (Liebig's), 21, 23. Bulbs, dividing, 39, 95. Bulbs from rod, 25. Bulbs, internal, 38. Bulbs, thick, 21. Cages, from glass rod, 24, 25, 27. Calibration, 72. Carius tubes, 16. Condenser, Liebig's, 37. Condensers, various, 37, 38. Cone, carbon, 8. Crack, leading, 30, 99. Cracking, subversive, 103. Cutting glass with diamond, 30. Cutting tubes, 11, 99. Diamond (glazier's), use of, 30. Dissimilar glass, joining of, 22, 94. Drilling, 61. Electrodes, sealing in, 42, 97. Etching glass, 70. Extemporised appliances, 80. Examination of apparatus, 93. Failure, Haste chief Source of, 103. Failures, Notes as to, 97. File, with oblique ground edge, 7. Filing glass, 63. Filter pumps, 35 Foot, 25 Fuels various, 82, 86, 87, 89. Funnel, thistle, 23. General principles and precautions, 1, 97 Glass, varieties of, 9, 55, 91-97. Graduation, 72-76 Haste, Source of Failure, 103 Heat reflector, asbestos, 7. Heating, intensive, 7, 57. Heating precautions, 12, 98 Joining dissimilar glass, 22. Joining glass to metal, 76. Joining tubes, 16, 94, 100. Knife, Glass blower's, 7, 99. Lenses, grinding, 63. Marking glass, 69. Methods, analytic study of, 91, 93. Oxygen for intensive heating, 57, 101. Precautions and General Principles, 1, 97. Pumps, Filter, 35. Pumps, Sprengel, 49, 50. Re-entering branch, 40. Reflector of heat, asbestos, 7. Rod, uses and articles from, 17, 25, 27, 28. Rod, blowing to hollow, 17, 25, 26, 91. Scrap glass, working, 90. Sealing tubes, 12, 13, 14. Sealed tubes for pressure, 15, 16. Sealing in of Electrodes, 42, 97. Seals, internal (airtraps), 32, 102. Silvering glass, 77. Soldering glass, 76. Soxhlet-tube, 40. Spirals, 23, 95. Spray arrester, 34. Spray producers, 36. Sprengel pumps, 49, 50. Spinning glass, 51. Stopcocks, 60, 66. Stoppering, 63. Stirrers, 28, 29. Summary as to precautions and failures, 97. Taps, 60, 66. Thermometers, Various, 44-49. Thermo-regulator, 24. Thistle Funnel, 23. Tools, Various small, 7. Turn-pins, 7, 8, 99. Turning out open ends, 14, 99. PRINTED IN GREAT BRITAIN BY W. JOLLY & SONS, LTD., PRINTERS, ABERDEEN. 
26106	----	US Patent 4,293,314: Gelled Fuel-Air Explosive United States Patent [19] [11] 4,293,314 Stull [45] Oct. 6, 1981 [54] GELLED FUEL-AIR EXPLOSIVE METHOD [75] Inventor: Bertram O. Stull, Ridgecrest, Calif. [73] Assignee: The United States of America as represented by the Secretary of the Navy, Washington, D.C. [21] Appl. No.: 111,453 [22] Filed: Jan. 11, 1980 [51] Int. Cl.^3 ................................ C10L 7/00 [52] U.S. Cl. ............................ 44/7 A; 44/7 R; 44/7 D; 102/90; 102/363 [58] Field of Search ................ 102/90; 44/7 R, 7 E, 44/7 D, 7 A [56] References Cited U.S. PATENT DOCUMENTS 3,539,311 11/1970 Cohen et al. ............. 44/7 A 3,634,157 1/1972 Batson ................... 44/7 E 3,685,453 8/1972 Hawrick .................. 102/90 3,730,093 5/1973 Cummings ................. 102/90 3,795,556 3/1974 Sippel et al. ............ 44/7 E 3,955,509 3/1976 Carlsen .................. 102/90 3,994,696 11/1976 Adicoff .................. 44/7 A 4,157,928 6/1979 Falterman et al. ......... 102/90 _Primary Examiner_--Edward A. Miller _Attorney, Agent, or Firm_--R. S. Sciascia; W. Thom Skeer; Lloyd E. K. Pohl [57] ABSTRACT 1,2-Butylene oxide as a fuel for a fuel air explosive weapon. The oxide may be used either as a pure liquid or gelled with a gelling agent such as silicon dioxide, particulate carbon or aluminum octoate. 3 Claims, No Drawings GELLED FUEL-AIR EXPLOSIVE METHOD BACKGROUND OF THE INVENTION 1. Field of the Invention 5 This invention relates to fuels for fuel air explosive weapons. More particularly, this invention relates to a method for causing an explosion comprising the steps of dispersing a cloud of liquid fuel in the air and detonating the cloud wherein the cloud is composed of particles of 10 gelled or ungelled 1,2-butylene oxide. 1. Description of the Prior Art Fuel air explosive weapons are now well known. A typical example of one is depicted in U.S. Pat. No. 3,955,509 which was issued to Gary A. Carlson on May 15 11, 1976. Fuel air explosive weapons may be described as devices which, upon activation, cause liquid fuel particles to be dispersed in the form of a detonable cloud in the air and then detonate the cloud. 20 A number of fuels have been used in fuel air explosive weapons. Among these are ethylene oxide and propylene oxide. Because of the ease with which is cloud of ethylene oxide or propylene oxide can be detonated, these two materials are the most commonly used. However, 25 these fuels have certain drawbacks. One drawback, common to both ethylene oxide and propylene oxide, is toxicity. Both materials are highly toxic. A concentration of 50 parts per million of ethylene oxide 30 in the air may have harmful effects on one breathing the air for about 8 hours. Propylene oxide is less toxic than ethylene oxide but is still highly toxic. A concentration of 100 parts per million of propylene oxide breathed for about 8 hours may have undesirable effects. Naturally, when fuel air explosive devices are stored in a confined 35 area such as aboard a ship, exposure for 8 hours is not unusual. Another drawback common to ethylene oxide and propylene oxide is the fact that both have relatively low boiling 40 points, 10.4° C. and 34.2° C. respectively. This makes the two difficult to handle in loading operations. High vapor pressures also contribute to difficulty in handling. A drawback particularly associated with ethylene oxide 45 is its tendency to polymerize during storage. Left alone in a fuel air explosive weapon or other container, ethylene oxide tends to self polymerize. The polymerized material is unsuitable for use as a fuel for a fuel air explosive device. Unpolymerized ethylene oxide, on the 50 other hand is highly desirable as a fuel insofar as detonability is concerned. Clouds containing from as little as 3 up to as much as 100 percent by volume of ethylene oxide are detonable. The detonation limits of propylene oxide, on the other hand, range from about 3.1 to about 27.5 percent by volume. 55 SUMMARY OF THE INVENTION It has now been found that 1,2-butylene oxide, when used as a fuel for fuel air explosive devices, exhibits marked superiority over either ethylene oxide or propylene 60 oxide. The marked superiority stems from the fact that 1,2-butylene oxide is about 3 times safer than propylene oxide when long exposure to it is required and about 3.5 times safer than ethylene oxide. Insofar as ease of detonation is concerned, 1,2-butylene oxide has about 65 the same explosive limits as propylene oxide. However, 1,2-butylene oxide is significantly easier to handle because its boiling point is nearly twice that of propylene oxide--63° C. as opposed to 34.2° C.--and over 6 times that of ethylene oxide. According to this invention 1,2-butylene oxide may be used in either its natural 5 liquid state or gelled with a hereinafter named gelling agent. DESCRIPTION OF THE PREFERRED EMBODIMENTS 10 In one embodiment of this invention, neat 1,2-butylene oxide liquid is used as the fuel in a fuel air explosive weapon in lieu of the previously most commonly used fuels, ethylene oxide and propylene oxide. It has been found that butylene oxide is significantly less toxic than 15 either of the two commonly used oxides. Air containing 400 parts per million of 1,2-butylene oxide may be breathed safely for up to 8 hours with no undesirable results as compared to 100 parts per million for propylene oxide and only 50 parts per million for ethylene 20 oxide. 1,2-butylene oxide offers a second distinct advantage over ethylene oxide and propylene oxide. Its boiling point is 63° C. as opposed to 10.4° C. and 34.2° C. 25 respectively for the other two oxides. Thus, loading operations are much easier to carry out. No special equipment is needed for its handling. Tests have shown that, insofar as ease of detonation is concerned, 1,2-butylene oxide is similar to propylene 30 oxide. Its explosive limits range from about 3.1 to 25.1 percent by volume as opposed to 3.1 to 27.5 percent by volume for propylene oxide. Thus, its significantly lower toxicity can be taken advantage of with very little loss in explosive efficiency. 35 Another factor contributing to the ease of handling of 1,2-butylene oxide is its vapor pressure. The vapor pressure of 1,2-butylene oxide is only 207.0 mm Hg at 25° C. as opposed to 1,292.0 for ethylene oxide and 569.0 for propylene oxide. 40 In a second embodiment of this invention, 1,2-butylene oxide may be used in a gelled state. It has been found that, if 1,2-butylene oxide is gelled by adding about 3 to about 10 weight percent of a gelling agent such as SiO_2 (Cab-O-Sil), particulate carbon or aluminum 45 octoate, it will still be dispersed into a detonable cloud by a typical fuel air explosive weapon. This is perhaps the best mode of practicing this invention for several reasons. First, the gel is more easily handled than the neat liquid. Second, if spilled the gel will not 50 disperse as a liquid will. In storage, no self-polymerization of 1,2-butylene oxide has been detected. Thus, a warhead loaded with the material has an indefinite shelf-life. I claim: 55 1. In a method for producing an explosion comprising the steps of dispersing a cloud of liquid particles in the air and detonating the cloud, the improvement residing in utilizing 1,2-butylene oxide in gel form as said liquid. 2. A method according to claim 1 wherein said gel consist essentially of 1,2-butylene oxide and a gelling agent selected from the group consisting of SiO_2, particulate carbon and aluminum octoate. 60 3. A method according to claim 2 wherein said gelling agent is present in an amount in the range of from 65 about 3 to about 10 weight percent. * * * * * 
15308	----	Department, Curtis Weyant, and the Online Distributed Proofreading Team NITRO-EXPLOSIVES [Illustration: DANGER BUILDING SHOWING PROTECTING MOUNDS. (_See page 6._)] NITRO-EXPLOSIVES A PRACTICAL TREATISE CONCERNING THE _PROPERTIES, MANUFACTURE, AND ANALYSIS OF NITRATED SUBSTANCES, INCLUDING THE FULMINATES, SMOKELESS POWDERS, AND CELLULOID_ BY P. GERALD SANFORD, F.I.C., F.C.S. _Public Analyst to the Borough of Penzance; late Consulting Chemist to the Cotton Powder Company Limited; and formerly Resident Chemist at the Stowmarket Works of the New Explosives Company Limited, and the Hayle Works of the National Explosive Company Limited_ ~Second Edition, Revised and Enlarged~ PREFACE. In compiling the following treatise, my aim has been to give a brief but thoroughly practical account of the properties, manufacture, and methods of analysis of the various nitro-explosives now so largely used for mining and blasting purposes and as propulsive agents; and it is believed that the account given of the manufacture of nitro-glycerine and of the gelatine dynamites will be found more complete than in any similar work yet published in this country. For many of the facts and figures contained in the chapter on Smokeless Powders I am indebted to (amongst others) the late Mr J.D. Dougall and Messrs A.C. Ponsonby and H.M. Chapman, F.C.S.; and for details with regard to Roburite to Messrs H.A. Krohn and W.J. Orsman, F.I.C. To these gentlemen my cordial thanks are due. Among the authorities which have been consulted in the general preparation of the work may be mentioned the _Journals_ of the Chemical Society, the Society of Chemical Industry, the United States Naval Institute, and the Royal Artillery Institution. I have also referred to several volumes of the periodical publication _Arms and Explosives;_ to various papers by Sir Frederick Abel, Bart., F.R.S., and General Wardell, R.A., on Gun-Cotton; to "Modern Artillery," by Capt. Lloyd, R.N., and A.G. Hadcock, R.A.; to the late Colonel Cundill's "Dictionary of Explosives"; as well as to the works of Messrs Eissler, Berthelot, and others. The illustrations have been prepared chiefly from my own drawings. A few, however, have been taken (by permission) from the pages of _Arms and Explosives_, or from other sources which are acknowledged in the text. P.G.S. THE LABORATORY, 20 CULLUM STREET, E.C. _May 1896._ PREFACE TO THE SECOND EDITION. In the preparation of the Second Edition of this work, I have chiefly made use of the current technical journals, especially of the _Journal of the Society of Chemical Industry_. The source of my information has in every case been acknowledged. I am also indebted to several manufacturers of explosives for information respecting their special products--among others the New Explosives Company Ltd.; Messrs Curtis's and Harvey Ltd.; The Schultze Gunpowder Company Ltd.; and Mr W.D. Borland, F.I.C., of the E.C. Powder Company Ltd. To my friend Mr A. Stanley Fox, F.C.S., of Faversham, my best thanks are also due for his help in many departments, and his kindness in pointing out several references. The chapter on Smokeless Powders has been considerably enlarged and (as far as possible) brought up to date; but it has not always been possible to give the process of manufacture or even the composition, as these details have not, in several cases, been made public. P. GERALD SANFORD. LONDON, _June 1906._ TABLE OF CONTENTS. CHAPTER I.--INTRODUCTION. The Nitro-Explosives--Substances that have been Nitrated--The Danger Area-- Systems of Professors Lodge, Zenger, and Melsens for the Protection of Buildings from Lightning, &c. CHAPTER II.--NITRO-GLYCERINE. Properties of Nitro-Glycerine--Manufacture--Nitration--Separation--Washing and Filtering--Drying, Storing, &c.--The Waste Acids--Their Treatment-- Nitric Acid Plants CHAPTER III.--NITRO-CELLULOSE, &C. Cellulose Properties--Discovery of Gun-Cotton--Properties of Gun-Cotton-- Varieties of Soluble and Insoluble Gun-Cottons--Manufacture of Gun-Cotton-- Dipping and Steeping�Whirling Out the Acid--Washing, Boiling, Pulping, Compressing--The Waltham Abbey Process--Le Bouchet Process--Granulation of Gun-Cotton--Collodion-Cotton--Manufacture--Acid Mixture Used--Cotton Used, &c.--Nitrated Gun-Cotton--Tonite--Dangers in Manufacture of Gun-Cotton-- Trench's Fire-Extinguishing Compound--Uses of Collodion-Cotton--Celluloid-- Manufacture, &c.--Nitro-Starch, Nitro-Jute, and Nitro-Mannite CHAPTER IV.--DYNAMITE. Kieselguhr Dynamite--Classification of Dynamites--Properties and Efficiency of Ordinary Dynamite--Other forms of Dynamite--Gelatine and Gelatine Dynamites, Suitable Gun-Cotton for, and Treatment of--Other Materials Used--Composition of Gelignite--Blasting Gelatine--Gelatine Dynamite--Absorbing Materials--Wood Pulp--Potassium Nitrate, &c.-- Manufacture, &c.--Apparatus Used--The Properties of the Gelatine Compounds CHAPTER V.--NITRO-BENZOL, ROBURITE, BELLITE, PICRIC ACID, &c. Explosives derived from Benzene--Toluene and Nitro-Benzene--Di- and Tri-nitro-Benzene--Roburite: Properties and Manufacture--Bellite: Properties, &c.--Securite--Tonite No. 3.--Nitro-Toluene-- Nitro-Naphthalene--Ammonite--Sprengel's Explosives--Picric Acid-- Picrates--Picric Powders--Melinite--Abel's Mixture--Brugère's Powders-- The Fulminates--Composition, Formula, Preparation, Danger of, &c.-- Detonators: Sizes, Composition, Manufacture--Fuses, &c. THE FULMINATES. Composition, Formula, Preparation, Danger of, &c.--Detonators: Sizes, Composition, Manufacture--Fuses, &c. CHAPTER VI.--SMOKELESS POWDERS IN GENERAL. Cordite--Axite--Ballistite--U.S. Naval Powder--Schultze's E.C. Powder-- Indurite--Vielle Poudre--Walsrode and Cooppal Powders--Amberite-- Troisdorf--B.N. Powder--Wetterin--Normal Powder--Maximite--Picric Acid Powders, &c. &c. CHAPTER VII.--ANALYSIS OF EXPLOSIVES. Kieselguhr Dynamite--Gelatine Compounds--Tonite--Cordite--Vaseline-- Acetone--Scheme for Analysis of Explosives--Nitro-Cotton--Solubility Test-- Non-Nitrated Cotton--Alkalinity--Ash and Inorganic Matter--Determination of Nitrogen--Lungé, Champion and Pellet's, Schultze-Tieman, and Kjeldahl's Methods--Celluloid--Picric Acid and Picrates--Resinous and Tarry Matters-- Sulphuric Acid and Hydrochloric Acid and Oxalic Acid--Nitric Acid-- Inorganic Impurities--General Impurities and Adulterations--Potassium Picrate, &c.--Picrates of the Alkaloids--Analysis of Glycerine--Residue-- Silver Test--Nitration--Total Acid Equivalent--Neutrality--Free Fatty Acids--Combined Fatty Acids--Impurities--Oleic Acid--Sodium Chloride-- Determination of Glycerine--Waste Acids--Sodium Nitrate--Mercury Fulminate--Cap Composition--Table for Correction of Volumes of Gases, for Temperature and Pressure CHAPTER VIII.--FIRING POINT OF EXPLOSIVES, HEAT TESTS, &C. Horsley's Apparatus--Table of Firing Points--The Government Heat Test Apparatus, &c., for Dynamites, Nitro-Glycerine, Nitro-Cotton, and Smokeless Powders--Guttmann's Heat Test--Liquefaction and Exudation Tests-- Page's Regulator for Heat Test Apparatus--Specific Gravities of Explosives--Will's Test for Nitro-Cellulose--Table of Temperature of Detonation, Sensitiveness, &c. CHAPTER IX.--THE DETERMINATION OF THE RELATIVE STRENGTH OF EXPLOSIVES. Effectiveness of an Explosive--High and Low Explosives--Theoretical Efficiency--M.M. Roux and Sarrau's Results--Abel and Noble's--Nobel's Ballistic Test--The Mortar--Pressure or Crusher Gauge--Calculation Volume of Gas Evolved, &c.--Lead Cylinders--The Foot-Pounds Machine--Noble's Pressure Gauge--Lieut. Walke's Results--Calculation of Pressure Developed by Dynamite and Gun-Cotton--McNab's and Ristori's Results of Heat Developed by the Explosion of Various Explosives--Composition of some of the Explosives in Common Use for Blasting, &c. INDEX LIST OF ILLUSTRATIONS. FRONTISPIECE--Danger Building showing Protecting Mounds. 1. Section of Nitro-Glycerine Conduit 2. Melsens System of Lightning Conductors 3. French System 4_a_ & 4_b_. English Government System 5. Upper Portion of Nitrator for Nitro-Glycerine 6. Small Nitrator 7. Nathan's Nitrator 8. Nitro-Glycerine Separator 9. Nitro-Glycerine Filtering Apparatus 10. Cotton-Waste Drier 11. Dipping Tank 12. Cooling Pits 13. Steeping Pot for Gun-Cotton 14. Hydro-Extractor or Centrifugal Drier 15_a_ & 15_b_. Gun-Cotton Beater 16_a_. Poacher for Pulping Gun-Cotton 16_b_. Plan of same 16_c_. Another form of Poacher 17 & 18. Compressed Gun-Cotton 19. Hydraulic Press 20. Thomson's Apparatus--Elevation 21. Elevation Plan 22. Trench's Safety Cartridge 23. Vessel used in Nitrating Paper 24. Cage ditto--White & Schupphaus' Apparatus 25. Do. do. do. 26 & 27. Nitrating Pot for Celluloid 28 & 29. Plunge Tank in Plan and Section 30. Messrs Werner, Pfleiderer & Perkins' Mixing Machine 31. M. 'Roberts' Mixing Machine for Blasting Gelatine 32. Plan of same 33. Cartridge Machine for Gelatines 34. Cartridge fitted with Fuse and Detonator 35. Gun-Cotton Primer 36. Electric Firing Apparatus 37. Metal Drum for Winding Cordite 38. Ten-Stranding 39. Curve showing relation between Pressures of Cordite and Black Powder, by Professor Vivian Lewes 40. Marshall's Apparatus for Moisture in Cordite 41. Lungé's Nitrometer 42. Modified do. 43. Horn's Nitrometer 44. Schultze-Tieman Apparatus for Determination of Nitrogen in Gun-Cotton 45. Decomposition Flask for Schultze-Tieman Method 46. Abel's Heat Test Apparatus 47. Apparatus for Separation of Nitro-Glycerine from Dynamite 48. Test Tube arranged for Heat Test 49. Page's Regulator 50. Do. showing Bye-Pass and Cut-off Arrangement 51. Will's Apparatus 52 & 53. Curves obtained 54. Dynamite Mortar 55. Quinan's Pressure Gauge 56. Steel Punch and Lead Cylinder for Use with Pressure Gauge 57. Micrometer Calipers for Measuring Thickness of Lead Cylinders 58. Section of Lead Cylinders before and after Explosion 59. Noble's Pressure Gauge 60. Crusher Gauge NITRO-EXPLOSIVES. CHAPTER I. _INTRODUCTORY._ The Nitro-Explosives--Substances that have been Nitrated--The Danger Area-- Systems of Professors Lodge, Zenger, and Melsens for the Protection of Buildings from Lightning, &c. The manufacture of the various nitro-explosives has made great advances during late years, and the various forms of nitro-compounds are gradually replacing the older forms of explosives, both for blasting purposes and also for propulsive agents, under the form of smokeless powders. The nitro-explosives belong to the so-called High Explosives, and may be defined as any chemical compound possessed of explosive properties, or capable of combining with metals to form an explosive compound, which is produced by the chemical action of nitric acid, either alone or mixed with sulphuric acid, upon any carbonaceous substance, whether such compound is mechanically mixed with other substances or not.[A] [Footnote A: Definition given in Order of Council, No. 1, Explosives Act, 1875.] The number of compounds and mixtures included under this definition is very large, and they are of very different chemical composition. Among the substances that have been nitrated are:--Cellulose, under various forms, e.g., cotton, lignin, &c.; glycerine, benzene, starch, jute, sugar, phenol, wood, straw, and even such substances as treacle and horse-dung. Some of these are not made upon the large scale, others are but little used. Those of most importance are nitro-glycerine and nitro-cellulose. The former enters into the composition of all dynamites, and several smokeless powders; and the second includes gun-cotton, collodion-cotton, nitrated wood, and the majority of the smokeless powders, which consist generally of nitro-cotton, nitro-lignin, nitro-jute, &c. &c., together with metallic nitrates, or nitro-glycerine. The nitro-explosives consist generally of some organic substance in which the NO_{2} group, known as nitryl, has been substituted in place of hydrogen. Thus in glycerine, |OH C_{3}H_{5}|OH, |OH which is a tri-hydric alcohol, and which occurs very widely distributed as the alcoholic or basic constituent of fats, the hydrogen atoms are replaced by the NO_{2} group, to form the highly explosive compound, nitro-glycerine. If one atom only is thus displaced, the mono-nitrate is formed thus, |ONO_{2} C_{3}H_{5}|OH; |OH and if the three atoms are displaced, C_{3}H_{5}(ONO_{2})_{3}, or the tri- nitrate, is formed, which is commercial nitro-glycerine. Another class, the nitro-celluloses, are formed from cellulose, C_{6}H_{10}O_{5}, which forms the groundwork of all vegetable tissues. Cellulose has some of the properties of the alcohols, and forms ethereal salts when treated with nitric and sulphuric acids. The hexa-nitrate, or gun-cotton, has the formula, C_{12}H_{14}O_{4}(ONO_{2})_{6}; and collodion-cotton, pyroxylin, &c., form the lower nitrates, i.e., the tetra- and penta-nitrates. These last are soluble in various solvents, such as ether-alcohol and nitro-glycerine, in which the hexa-nitrate is insoluble. They all dissolve, however, in acetone and acetic ether. The solution of the soluble varieties in ether-alcohol is known as collodion, which finds many applications in the arts. The hydrocarbon benzene, C_{6}H_{6}, prepared from the light oil obtained from coal-tar, when nitrated forms nitro-benzenes, such as mono-nitro-benzene, C_{6}H_{5}NO_{2}, and di-nitro-benzene, C_{6}H_{4}(NO_{2})_{2}, in which one and two atoms are replaced by the NO_{2} group. The latter of these compounds is used as an explosive, and enters into the composition of such well-known explosives as roburite, &c. The presence of nitro groups in a substance increases the difficulty of further nitration, and in any case not more than three nitro groups can be introduced into an aromatic compound, or the phenols. All aromatic compounds with the general formula, C_{6}H_{4}X_{2}, give, however, three series. They are called ortho, meta, or para compounds, depending upon the position of NO_{2} groups introduced. Certain regularities have been observed in the formation of nitro- compounds. If, for example, a substance contains alkyl or hydroxyl groups, large quantities of the para compound are obtained, and very little of the ortho. The substitution takes place, however, almost entirely in the meta position, if a nitro, carboxyl, or aldehyde group be present. Ordinary phenol, C_{6}H_{5}.OH, gives para- and ortho-nitro-phenol; toluene gives para- and ortho-nitro-toluene; but nitro-benzene forms meta-di-nitro- benzene and benzoic acid, meta-nitro-benzoic acid.[A] [Footnote A: "Organic Chemistry," Prof. Hjelt. Translated by J.B. Tingle, Ph.D.] If the graphic formula of benzene be represented thus (No. 1), then the positions 1 and 2 represent the ortho, 1 and 3 the meta, and 1 and 4 the para compounds. When the body phenol, C_{6}H_{5}.OH, is nitrated, a compound is formed known as tri-nitro-phenol, or picric acid, C_{6}H_{2}(NO_{2})_{3}OH, which is used very extensively as an explosive, both as picric acid and in the form of picrates. Another nitro body that is used as an explosive is nitro-naphthalene, C_{10}H_{6}(NO_{2})_{2}, in roburite, securite, and other explosives of this class. The hexa-nitro- mannite, C_{6}H_{8}(ONO_{2})_{6}, is formed [Illustration: No. 1] [Illustration: META-DINITRO-BENZENE No.2] by treating a substance known as mannite, C_{6}H_{8}(OH)_{6}, an alcohol formed by the lactic acid fermentation of sugar and closely related to the sugars, with nitric and sulphuric acids. It is a solid substance, and very explosive; it contains 18.58 per cent. of nitrogen. Nitro-starch has also been used for the manufacture of an explosive. Muhlhauer has described (_Ding. Poly. Jour._, 73, 137-143) three nitric ethers of starch, the tetra-nitro-starch, C_{12}H_{16}O_{6}(ONO_{2})_{4}, the penta- and hexa-nitro-starch. They are formed by acting upon potato starch dried at 100° C. with a mixture of nitric and sulphuric acids at a temperature of 20° to 25° C. Rice starch has also been used in its production. Muhlhauer proposes to use this body as a smokeless powder, and to nitrate it with the spent mixed acids from the manufacture of nitro- glycerine. This substance contains from 10.96 to 11.09 per cent. of nitrogen. It is a white substance, very stable and soluble even in cold nitro-glycerine. The explosive bodies formed by the nitration of jute have been studied by Messrs Cross and Bevan. and also by Mühlhäuer. The former chemists give jute the formula C_{12}H_{18}O_{9}, and believe that its conversion into a nitro-compound takes place according to the equation-- C_{12}H_{18}O_{9} + 3HNO_{3} = 3H_{2}O + C_{12}H_{15}O_(6}(NO_{3})_{3}. This is equivalent to a gain in weight of 44 per cent. for the tri- nitrate, and 58 per cent. for the tetra-nitrate. The formation of the tetra-nitrate appears to be the limit of nitration of jute fibre. Messrs Cross and Bevan say, "In other words, if we represent the ligno-cellulose molecule by a C_{12} formula, it will contain four hydroxyl (OH) groups, or two less than cellulose similarly represented." It contains 11.5 per cent. of nitrogen. The jute nitrates resemble those of cellulose, and are in all essential points nitrates of ligno-cellulose. Nitro-jute is used in the composition of the well-known Cooppal Smokeless Powders. Cross and Bevan are of opinion that there is no very obvious advantage in the use of lignified textile fibres as raw materials for explosive nitrates, seeing that a number of raw materials containing cellulose (chiefly as cotton) can be obtained at from £10 to £25 a ton, and yield also 150 to 170 per cent. of explosive material when nitrated (whereas jute only gives 154.4 per cent.), and are in many ways superior to the products obtained from jute. Nitro-lignin, or nitrated wood, is, however, largely used in the composition of a good many of the smokeless powders, such as Schultze's, the Smokeless Powder Co.'s products, and others. ~The Danger Area.~--That portion of the works that is devoted to the actual manufacture or mixing of explosive material is generally designated by the term "danger area," and the buildings erected upon it are spoken of as "danger buildings." The best material of which to construct these buildings is of wood, as in the event of an explosion they will offer less resistance, and will cause much less danger than brick or stone buildings. When an explosion of nitro-glycerine or dynamite occurs in one of these buildings, the sides are generally blown out, and the roof is raised some considerable height, and finally descends upon the blown-out sides. If, on the other hand, the same explosion had occurred in a strong brick or stone building, the walls of which would offer a much larger resistance, large pieces of brickwork would probably have been thrown for a considerable distance, and have caused serious damage to surrounding buildings. It is also a very good plan to surround all danger buildings with mounds of sand or earth, which should be covered with turf, and of such a height as to be above the roof of the buildings that they are intended to protect (see frontispiece).[A] These mounds are of great value in confining the force of the explosion, and the sides of the buildings being thrown against them are prevented from travelling any distance. In gunpowder works it is not unusual to surround the danger buildings with trees or dense underwood instead of mounds. This would be of no use in checking the force of explosion of the high explosives, but has been found a very useful precaution in the case of gunpowder. [Footnote A: At the Baelen Factory, Belgium, the danger buildings are erected on a novel plan. They are circular in ground plan and lighted entirely from the roof by means of a patent glass having wire-netting in it, and which it is claimed will not let a splinter fall, even if badly cracked. The mounds are then erected right up against the walls of the building, exceeding them in height by several metres. For this method of construction it is claimed that the force exerted by an explosion will expand itself in a vertical direction ("Report on Visits to Certain Explosive Factories," H.M. Inspectors, 1905).] In Great Britain it is necessary that all danger buildings should be a specified distance apart; a license also must be obtained. The application for a license must give a plan (drawn to scale) of the proposed factory or magazine, and the site, its boundaries, and surroundings, and distance the building will be from any other buildings or works, &c., also the character, and construction of all the mounds, and nature of the processes to be carried on in the factory or building.[A] [Footnote A: Explosives Act, 38 Vict. ch. 17.] [Illustration: FIG. 1.--SECTION OF NITRO-GLYCERINE CONDUIT. _a_, lid; _b_, lead lining; _c_, cinders.] The selection of a site for the danger area requires some attention. The purpose for which it is required, that is, the kind of explosive that it is intended to manufacture, must be taken into consideration. A perfectly level piece of ground might probably be quite suitable for the purpose of erecting a factory for the manufacture of gun-cotton or gunpowder, and such materials, but would be more or less unsuitable for the manufacture of nitro-glycerine, where a number of buildings are required to be upon different levels, in order to allow of the flow of the liquid nitro- glycerine from one building to another through a system of conduits. These conduits (Fig. 1), which are generally made of wood and lined with lead, the space between the woodwork and the lead lining, which is generally some 4 or 5 inches, being filled with cinders, connect the various buildings, and should slope gently from one to the other. It is also desirable that, as far as possible, they should be protected by earth-work banks, in the same way as the danger buildings themselves. They should also be provided with covers, which should be whitewashed in hot weather. A great deal of attention should be given to these conduits, and they should be very frequently inspected. Whenever it is found that a portion of the lead lining requires repairing, before cutting away the lead it should be very carefully washed, for several feet on either side of the portion that it is intended to remove, with a solution of caustic soda or potash dissolved in methylated spirit and water, and afterwards with water alone. This decomposes the nitro-glycerine forming glycerine and potassium nitrate. It will be found that the mixed acids attack the lead rather quickly, forming sulphate and nitrate of lead, but chiefly the former. It is on this account that it has been proposed to use pipes made of guttapercha, but the great drawback to their use is that in the case of anything occurring inside the pipes, such as the freezing of the nitro- glycerine in winter, it is more difficult to find it out, and the condition of the inside cannot be seen, whereas in the case of wooden conduits it is an easy matter to lift the lids along the whole length of the conduit. The buildings which require to be connected by conduits are of course those concerned with the manufacture of nitro-glycerine. These buildings are--(1) The nitrating house; (2) the separating house; (3) the filter house; (4) the secondary separator; (5) the deposit of washings; (6) the settling or precipitation house; and each of these buildings must be on a level lower than the preceding one, in order that the nitro-glycerine or acids may flow easily from one building to the next. These buildings are, as far as possible, best placed together, and away from the other danger buildings, such as the cartridge huts and dynamite mixing houses, but this is not essential. All danger buildings should be protected by a lightning conductor, or covered with barbed wire, as suggested by Professor Sir Oliver J. Lodge, F.R.S., Professors Zenger, of Prague, and Melsens, of Brussels, and everything possible should be done to keep them as cool as possible in the summer. With this object they should be made double, and the intervening space filled with cinders. The roof also should be kept whitewashed, and the windows painted over thinly with white paint. A thermometer should be suspended in every house. It is very essential that the floors of all these buildings should be washed every day before the work-people leave. In case any nitro-glycerine is spilt upon the floors, after sponging it up as far as possible, the floor should be washed with an alcoholic solution of soda or potash to decompose the nitro-glycerine, which it does according to the equation[A]-- C_{3}H_{5}(NO_{3})_{3} + 3KOH = C_{3}H_{8}O_{3} + 3KNO_{3}. [Footnote A: See also Berthelot, _Comptes Rendus_, 1900, 131[12], 519- 521.] Every one employed in the buildings should wear list or sewn leather shoes, which of course must be worn in the buildings only. The various houses should be connected by paths laid with cinders, or boarded with planks, and any loose sand about the site of the works should be covered over with turf or cinders, to prevent its blowing about and getting into the buildings. It is also of importance that stand pipes should be placed about the works with a good pressure of water, the necessary hose being kept in certain known places where they can be at once got at in the case of fire, such as the danger area laboratory, the foreman's office, &c. It is also desirable that the above precautions against fire should be tested once a week. With regard to the heating of the various buildings in the winter, steam pipes only should be used, and should be brought from a boiler-house outside the danger area, and should be covered with kieselguhr or fossil meal and tarred canvas. These pipes may be supported upon poles. A stove of some kind should be placed in the corner of each building, but it must be entirely covered in with woodwork, and as small a length of steam pipes should be within the building as possible. In the case of a factory where nitro-glycerine and dynamite are manufactured, it is necessary that the work-people should wear different clothes upon the danger area than usual, as they are apt to become impregnated with nitro-glycerine, and thus not very desirable or safe to wear outside the works. It is also necessary that these clothes should not contain any pockets, as this lessens the chance of matches or steel implements being taken upon the danger area. Changing houses, one for the men, and another for the girls, should also be provided. The tools used upon the danger area should, whenever the building is in use, or contains explosives, be made of phosphor bronze or brass, and brass nails or wooden pegs should be used in the construction of all the buildings. [Illustration: FIG. 2.--MELSENS SYSTEM OF LIGHTNING CONDUCTORS.] ~Lightning Conductors.~--The Explosive Substances Act, 38 Vict. ch. 17, clause 10, says, "Every factory magazine and expense magazine in a factory, and every danger building in a magazine, shall have attached thereto a sufficient lightning conductor, unless by reason of the construction by excavation or the position of such magazine or building, or otherwise, the Secretary of State considers a conductor unnecessary, and every danger building in a factory shall, if so required by the Secretary of State, have attached thereto a sufficient lightning conductor." The exact form of lightning conductor most suitable for explosive works and buildings has not yet been definitely settled. Lightning-rod engineers favour what is known as the Melsens system, due to Professor Melsens, of Brussels, and Professor Zenger, of Prague, but first suggested by the late Professor Clerk-Maxwell. In a paper read before the British Association, Clerk-Maxwell proposed to protect powder-magazines from the effects of lightning by completely surrounding or encasing them with sheet metal, or a cage of metallic conductors. There were, however, several objections to his system as he left it. Professor Melsens[A] has, while using the idea, made several important alterations. He has multiplied the terminals, the conductors, and the earth-connections. His terminals are very numerous, and assume the form of an aigrette or brush with five or seven points, the central point being a little higher than the rest, which form with it an angle of 45°. He employs for the most part galvanised-iron wire. He places all metallic bodies, if they are of any considerable size, in communication with the conducting system in such a manner as to form closed metallic circuits. His system is illustrated in Fig. 2, taken from _Arms and Explosives_. [Footnote A: Belgian Academy of Science.] This system is a near approximation to J.C. Maxwell's cage. The system was really designed for the protection of powder-magazines or store buildings placed in very exposed situations. Zenger's system is identical with that of Melsens, and has been extensively tried by the Austrian military authorities, and Colonel Hess has reported upon the absolute safety of the system. [Illustration: Fig. 3.--FRENCH SYSTEM OF LIGHTNING CONDUCTORS.] The French system of protecting powder-magazines is shown in Fig. 3, where there are no brush terminals or aigrettes. The French military authorities also protect magazines by erecting two or more lightning-rods on poles of sufficient height placed close to, but not touching, the walls of the magazine. These conductors are joined below the foundations and earthed as usual. In the instructions issued by the Government, it is stated that the lightning-rods placed upon powder-mills should be of such a height, and so situated, that no danger is incurred in igniting the powder-dust in the air by the lightning discharge at the pointed rod. In such a case a fork or aigrette of five or more points should invariably be used in place of a single point. [Illustration: FIG. 4_a_.--GOVERNMENT SYSTEM OF LIGHTNING CONDUCTORS FOR LARGE BUILDINGS.] [Illustration: FIG. 4_b_.--GOVERNMENT SYSTEM OF LIGHTNING CONDUCTORS FOR SMALL BUILDINGS.] In Fig. 4 (_a_ and _b_) is shown the Government method for protecting buildings in which explosives are made or stored. Multiple points or aigrettes would be better. Lord Kelvin and Professor Melsens favour points, and it is generally admitted that lightning does not strike buildings at a single point, but rather in a sheet; hence, in such cases, or in the event of the globular form being assumed by the lightning, the aigrette will constitute a much more effective protection than a single point. As to the spacing of conductors, they may, even on the most important buildings, be spaced at intervals of 50 feet. There will then be no point on the building more than 25 feet from the conductor. This "25-feet rule" can be adhered to with advantage in all overground buildings for explosives. Underground magazines should, whenever possible, also be protected, because, although less exposed than overground buildings, they frequently contain explosives packed in metal cases, and hence would present a line of smaller electrical resistance than the surrounding earth would offer to the lightning. The conductor should be arranged on the same system as for overground buildings, but be applied to the surface of the ground over the magazines. In all situations where several conductors are joined in one system, the vertical conductors should be connected both at the top and near the ground line. The angles and the prominent portions of a building being the most liable to be struck, the conductors should be carried over and along these projections, and therefore along the ridges of the roof. The conductors should be connected to any outside metal on the roofs and walls, and specially to the foot of rain-water pipes. All the lightning conductors should be periodically tested, to see that they are in working condition, at least every three months, according to Mr Richard Anderson. The object of the test is to determine the resistance of the earth-connection, and to localise any defective joints or parts in the conductors. The best system of testing the conductors is to balance the resistance of each of the earths against the remainder of the system, from which the state of the earths may be inferred with sufficient accuracy for all practical purposes. Captain Bucknill, R.E., has designed an instrument to test resistance which is based on the Post Office pattern resistance coil, and is capable of testing to approximate accuracy up to 200 ohms, and to measure roughly up to 2,000 ohms. Mr R. Anderson's apparatus is also very handy, consisting of a case containing three Leclanché cells, and a galvanometer with a "tangent" scale and certain standard resistances. Some useful articles on the protection of buildings from lightning will be found in _Arms and Explosives_, July, August, and September 1892, and by Mr Anderson, Brit. Assoc., 1878-80. ~Nitro-Glycerine.~--One of the most powerful of modern explosive agents is nitro-glycerine. It is the explosive contained in dynamite, and forms the greater part of the various forms of blasting gelatines, such as gelatine dynamite and gelignite, both of which substances consist of a mixture of gun-cotton dissolved in nitro-glycerine, with the addition of varying proportions of wood-pulp and saltpetre, the latter substances acting as absorbing materials for the viscid gelatine. Nitro-glycerine is also largely used in the manufacture of smokeless powders, such as cordite, ballistite, and several others. Nitro-glycerol, or glycerol tri-nitrate, was discovered by Sobrero in the year 1847. In a letter written to M. Pelouse, he says, "when glycerol is poured into a mixture of sulphuric acid of a specific gravity of 1.84, and of nitric acid of a gravity of 1.5, which has been cooled by a freezing mixture, that an oily liquid is formed." This liquid is nitro-glycerol, or nitro-glycerine, which for some years found no important use in the arts, until the year 1863, when Alfred Nobel first started a factory in Stockholm for its manufacture upon a large scale; but on account of some serious accidents taking place, its use did not become general. It was not until Nobel conceived the idea (in 1866) of absorbing the liquid in some absorbent earth, and thus forming the material that is now known as dynamite, that the use of nitro-glycerine as an explosive became general. Among those who improved the manufacture of nitro-glycerine was Mowbray, who, by using pure glycerine and nitric acid free from nitrous acid, made very great advances in the manufacture. Mowbray was probably the first to use compressed air for the purpose of keeping the liquids well agitated during the process of nitration, which he conducted in earthenware pots, each containing a charge of 17 lbs. of the mixed acids and 2 lbs. of glycerol. A few years later (1872), MM. Boutnny and Faucher, of Vonges,[A] proposed to prepare nitro-glycerine by mixing the sulphuric acid with the glycerine, thus forming a sulpho-glyceric acid, which was afterwards mixed with a mixture of nitric and sulphuric acids. They claimed for this method of procedure that the final temperature is much lower. The two mixtures are mixed in the proportions--Glycerine, 100; nitric acid, 280; and sulphuric acid, 600. They state that the rise of temperature upon mixing is limited from 10° to 15° C.; but this method requires a period of twenty-four hours to complete the nitration, which, considering the danger of keeping the nitro-glycerine in contact with the mixed acids for so long, probably more than compensates for the somewhat doubtful advantage of being able to perform the nitration at such a low temperature. The Boutnny process was in operation for some time at Pembrey Burrows in Wales, but after a serious explosion the process was abandoned. [Footnote A: _Comptes Rendus_, 75; and Desortiaux, "Traité sur la Poudre," 684-686.] Nitro-glycerine is now generally made by adding the glycerine to a mixture of sulphuric and nitric acids. The sulphuric acid, however, takes no part in the reaction, but is absolutely necessary to combine with the water that is formed by the decomposition, and thus to keep up the strength of the nitric acid, otherwise lower nitrates of glycerine would be formed that are soluble in water, and which would be lost in the subsequent process of washing to which the nitro-compound is subjected, in order to remove the excess of acids, the retention of which in the nitro-glycerol is very dangerous. Nitro-glycerol, which was formerly considered to be a nitro-substitution compound of glycerol, was thought to be formed thus-- C_{3}H_{8}O_{3} + 3HNO_{3} = C{3}H_{5}(NO_{2})_{3}O_{3} + 3H_{2}O; but more recent researches rather point to its being regarded as a nitric ether of glycerol, or glycerine, and to its being formed thus-- C_{3}H_{8}O_{3} + 3 HNO_{3} = C{3}H_{5}(NO_{3})_{3} + 3H_{2}O. 92 227 |OH The formula of glycerine is C_{3}H_{8}O_{8}, or C_{3}H_{5}|OH |OH |ONO_{2} and that of the mono-nitrate of glycerine, C_{3}H_{5}|OH |OH |ONO_{2} and of the tri-nitrate or (nitro-glycerine), C_{3}H_{5}|ONO_{2} |ONO_{2} that is, the three hydrogens of the semi-molecules of hydroxyl in the glycerine have been replaced by the NO_{2} group. In the manufacture upon the large scale, a mixture of three parts by weight of nitric acid and five parts of sulphuric acid are used. From the above equation it will be seen that every 1 lb. of glycerol should give 2.47 lbs. of nitro-glycerol ((227+1)/92 = 2.47), but in practice the yield is only about 2 lbs. to 2.22, the loss being accounted for by the unavoidable formation of some of the lower nitrate, which dissolves in water, and is thus washed away, and partly perhaps to the presence of a little water (or other non-nitrable matter) in the glycerine, but chiefly to the former, which is due to the acids having become too weak. CHAPTER II. _MANUFACTURE OF NITRO-GLYCERINE._ Properties of Nitro-Glycerine--Manufacture of Nitro-Glycerine--Nitration-- The Nathan Nitrator--Separation--Filtering and Washing--The Waste Acids-- Treatment of the Waste Acid from the Manufacture of Nitro-Glycerine and Gun-Cotton. ~Properties of Nitro-Glycerine.~--Nitro-glycerol is a heavy oily liquid of specific gravity 1.6 at 15° C., and when quite pure is colourless. The commercial product is a pale straw yellow, but varies much according to the purity of the materials used in its manufacture. It is insoluble in water, crystallises at 10.5° C., but different commercial samples behave very differently in this respect, and minute impurities prevent or delay crystallisation. Solid nitro-glycerol[A] melts at about 12° C., but requires to be exposed to this temperature for some time before melting. The specific gravity of the solid form is 1.735 at +10° C.; it contracts one-twelfth of its volume in solidifying. Beckerheim[B] gives the specific heat as 0.4248 between the temperatures of 9.5° and 9.8° C., and L. de Bruyn gives the boiling point as above 200°. [Footnote A: Di-nitro-mono chlorhydrin, when added to nitro-glycerine up to 20 per cent., is said to prevent its freezing.] [Footnote B: _Isb., Chem. Tech._, 22, 481-487. 1876.] Nitro-glycerine has a sweet taste, and causes great depression and vertigo. It is soluble in ether, chloroform, benzene, glacial acetic acid, and nitro-benzene, in 1.75 part of methylated spirit, very nearly insoluble in water, and practically insoluble in carbon bisulphide. Its formula is C_{3}H_{5}(NO_{3})_{3}, and molecular weight 227. When pure, it may be kept any length of time without decomposition. Berthelot kept a sample for ten years, and Mr G. M'Roberts, of the Ardeer Factory, for nine years, without their showing signs of decomposition; but if it should contain the smallest trace of free acid, decomposition is certain to be started before long. This will generally show itself by the formation of little green spots in the gelatine compounds, or a green ring upon the surface of liquid nitro-glycerine. Sunlight will often cause it to explode; in fact, a bucket containing some water that had been used to wash nitro-glycerine, and had been left standing in the sun, has in our experience been known to explode with considerable force. Nitro-glycerine when pure is quite stable at ordinary temperatures, and samples have been kept for years without any trace of decomposition. It is very susceptible to heat, and even when quite pure will not stand a temperature of 100° C. for a longer period than a few hours, without undergoing decomposition. Up to a temperature of 45° C., however, properly made and purified nitro- glycerine will remain unchanged almost indefinitely. The percentage composition of nitroglycerine is as follows:-- Found. Theory for C_{3}H_{5}(N0_{2})_{3}. Carbon 15.62 15.86 per cent. Hydrogen 2.40 2.20 " Nitrogen 17.90 18.50 " Oxygen ... 63.44 " The above analysis is by Beckerheim. Sauer and Adou give the nitrogen as 18.35 to 10.54 per cent. by Dumas' method; but I have never found any difficulty in obtaining percentages as high as 18.46 by the use of Lunge's nitrometer. The decomposition products by explosion are shown by the following equation-- 2C_{3}H_{5}(NO_{3})_{3} = 6CO_{2} + 5H_{2}O + 6N + O; that is, it contains an excess of 3.52 per cent. of oxygen above that required for complete combustion; 100 grms. would be converted into-- Carbonic Acid (CO_{2}) 58.15 per cent. Water 19.83 " Oxygen 3.52 per cent. Nitrogen 18.50 " The volume of gases produced at 0° and 760 mm., calculated from the above, is 714 litres per kilo, the water being taken as gaseous. Nitro-glycerine is decomposed differently if it is ignited as dynamite (i.e., kieselguhr dynamite), and if the gases are allowed to escape freely under a pressure nearly equal to that of the atmosphere. Sarrau and Vieille obtained under these conditions, for 100 volumes of gas-- NO 48.2 per cent. CO 35.9 " CO_{2} 12.7 " H 1.6 per cent. N 1.3 " CH_{4} 0.3 " These conditions are similar to those under which a mining charge, simply ignited by the cap, burns away slowly under a low pressure (i.e., a miss fire). In a recent communication, P.F. Chalon (_Engineering and Mining Journal_, 1892) says, that in practice nitro-glycerine vapour, carbon monoxide, and nitrous oxide, are also produced as the result of detonation, but he attributes their formation to the use of a too feeble detonator. Nitro-glycerine explodes very violently by concussion. It may be burned in an open vessel, but if heated above 250° C. it explodes. Professor C.E. Munroe gives the firing point as 2O3°-2O5° C., and L. de Bruyn[A] states its boiling point as 185°. He used the apparatus devised by Horsley. The heat of formation of nitro-glycerine, as deduced from the heat of combustion by M. Longuinine, is 432 calories for 1 grm.; and the heat of combustion equals 1,576 cals. for 1 grm. In the case of nitro-glycerine the heat of total combustion and the heat of complete decomposition are interchangeable terms, since it contains an excess of oxygen. According to Dr W.H. Perkin, F.R.S.,[B] the magnetic rotation of nitro-gylcerine is 5,407, and that of tri-methylene nitrate, 4.769 (diff. = .638). Dr Perkin says: "Had nitro-glycerine contained its nitrogen in any other combination with oxygen than as -O-NO_{2}, as it might if its constitution had been represented as C_{3}H_{2}(NO_{2})_{3}(OH)_{3}, the rotation when compared with propyl nitrate (4.085) would be abnormal." [Footnote A: _Jour. Soc. Chem. Ind._, June 1896, p. 471.] [Footnote B: _Jour. Chem. Soc._, W.H. Perkin, 1889, p. 726.] The solubility of nitro-glycerine in various solvents has been investigated by A.H. Elliot; his results may be summarised as follows:-- _______________________________________________________________________ | | Solvent. | Cold. | Warm. _____________________________|______________________|__________________ | | Water | Insoluble | Slightly soluble Alcohol, absolute | Soluble | Soluble " 93% | " | " " 80% | Slowly soluble | " " 50% | Insoluble | Slightly soluble Methyl alcohol | Soluble | Soluble Amyl " | " | " Ether, ethylic | " | " " acetic | " | " Chloroform | " | " Acetone | " | " Sulphuric acid (1.845) | " | " Nitric acid (1.400) | Slowly soluble | " Hydrochloric acid (1.200) | Insoluble, decomposed| Slowly soluble Acetic acid, glacial | Soluble | Soluble Carbolic acid | " | " Astral oil | Insoluble | Insoluble Olive " | Soluble | Soluble Stearine oil | " | " Mineral jelly | Insoluble | Insoluble Glycerine | " | " Benzene | Soluble | Soluble Nitro-benzene | " | " Toluene | " | " Carbon bi-sulphide | Insoluble | Slightly affected Turpentine | " | Soluble Petroleum naphtha, 71°-76° B.| " | Insoluble Caustic soda (1:10 solution) | Insoluble. | Insoluble. Borax, 5% solution | " | " Ammonia (.980) | " | " slightly | | affected. Ammonium sulph-hydrate | Insoluble, sulphur | Decomposed. | separates | Iron sulphate solution | Slightly affected | Affected. Iron chloride (1.4 grm. Fe | Slowly affected | Decomposed. to 10 c.c. N_{2}O) | | Tin chloride | Slightly affected | Affected. _____________________________|______________________|__________________ Many attempts have been made to prepare nitro-glycerine explosives capable of withstanding comparatively low temperatures without freezing, but no satisfactory solution of the problem has been found. Among the substances that have been proposed and used with more or less success, are nitro- benzene, nitro-toluene, di-nitro-mono-chlorhydrine, solid nitro derivatives of toluene,[A] are stated to lower the freezing point of nitro-glycerine to -20°C. without altering its sensitiveness and stability. The subject has been investigated by S. Nauckhoff,[B] who states that nitroglycerine can be cooled to temperatures (-40° to -50° C.) much below its true freezing point, without solidifying, by the addition of various substances. When cooled by means of a mixture of solid carbon, dioxide, and ether, it sets to a glassy mass, without any perceptible crystallisation. The mass when warmed to 0°C. first rapidly liquefies and then begins to crystallise. The true freezing point of pure nitro- glycerine was found to be 12.3°C. The technical product, owing to the presence of di-nitro-glycerine, freezes at 10.5° C. According to Raoult's law, the lowering of the freezing point caused by _m_ grms. of a substance with the molecular weight M, when dissolved in 100 grms. of the solvent, is expressed by the formula: [Delta] = E(_m_/M), where E is a constant characteristic for the solvent in question. The value of E for nitro- glycerine was found to be 70.5 when calculated, according to Van't Hoff's formula, from the melting point and the latent heat of fusion of the substance. Determinations of the lowering of the freezing point of nitro- glycerine by additions of benzene, nitro-benzene, di-nitro-benzene, tri- nitro-benzene, p.-nitro-toluene, o.-nitro-toluene, di-nitro-toluene, naphthalene, nitro-naphthalene, di-nitro-naphthalene, ethyl acetate, ethyl nitrate, and methyl alcohol, gave results agreeing fairly well with Raoult's formula, except in the case of methyl alcohol, for which the calculated lowering of the freezing point was greater than that observed, probably owing to the formation of complex molecules in the solution. The results show that, in general, the capacity of a substance to lower the freezing point of nitro-glycerine depends, not upon its freezing point, or its chemical composition or constitution, but upon its molecular weight. Nauckhoff states that a suitable substance for dissolving in nitro- glycerine, in order to lower the freezing point of the latter, must have a relatively low molecular weight, must not appreciably diminish the explosive power and stability of the explosive, and must not be easily volatile at relatively high atmospheric temperatures; it should, if possible, be a solvent of nitro-cellulose, and in every case must not have a prejudicial influence on the gelatinisation of the nitro-cellulose. [Footnote A: Eng. Pat. 25,797, November 1904.] [Footnote B: _Z. Angew. Chem._, 1905, 18, 11-22, 53-60.] ~Manufacture of Nitro-Glycerine.~--Nitro-glycerine is prepared upon the manufacturing scale by gradually adding glycerine to a mixture of nitric and sulphuric acids of great strength. The mixed acids are contained in a lead vessel, which is kept cool by a stream of water continually passing through worms in the interior of the nitrating vessel, and the glycerine is gradually added in the form of a fine stream from above. The manufacture can be divided into three distinct operations, viz., nitration, separation, and washing, and it will be well to describe these operations in the above order. ~Nitration.~--The most essential condition of nitrating is the correct composition and strength of the mixed acids. The best proportions have been found to be three parts by weight of nitric acid of a specific gravity 1.525 to 1.530, and containing as small a portion of the oxides of nitrogen as possible, to five parts by weight of sulphuric acid of a specific gravity of 1.840 at 15° C., and about 97 per cent. of mono- hydrate. It is of the very greatest importance that the nitric acid should be as strong as possible. Nothing under a gravity of 1.52 should ever be used even to mix with stronger acid, and the nitration will be proportional to the strength of the acid used, provided the sulphuric acid is also strong enough. It is also of great importance that the oxides of nitrogen should be low, and that they should be kept down to as low as 1 per cent., or even lower. It is also very desirable that the nitric acid should contain as little chlorine as possible. The following is the analysis of a sample of nitric acid, which gave very good results upon the commercial scale:--Specific gravity, 1.525, N_{2}O_{4}, 1.03 per cent.; nitric acid (HNO_{3}), 95.58 per cent. The amount of real nitric acid (mono-hydrate) and the amount of nitric peroxide present in any sample should always be determined before it is used for nitrating purposes. The specific gravity is not a sufficient guide to the strength of the acid, as an acid having a high gravity, due to some 3 or 4 per cent of nitric oxides in solution, will give very poor nitration results. A tenth normal solution of sodium hydroxide (NaOH), with phenol-phthalein as indicator, will be found the most convenient method of determining the total acid present. The following method will be found to be very rapid and reliable:--Weigh a 100 c.c. flask, containing a few cubic centimetres of distilled water, and then add from a pipette 1 c.c. of the nitric acid to be examined, and reweigh (this gives the weight of acid taken). Now make up to 100 c.c. at 15° C.; shake well, and take out 10 c.c. with a pipette; drain into a small Erlenmeyer flask, and add a little of the phenol-phthalein solution, and titrate with the tenth normal soda solution. The nitric peroxide can be determined with a solution of potassium permanganate of N/10 strength, thus: Take a small conical flask, containing about 10 c.c. of water, and add from a burette 10 to 16 c.c. of the permanganate solution; then add 2 c.c. of the acid to be tested, and shake gently, and continue to add permanganate solution as long as it is decolourised, and until a faint pink colour is permanent. _Example._ N/10 permanganate 3.16 grms. per litre, 1 c.c. = O.0046 grm. N_{2}O_{4}, 2 c.c. of sample of acid specific gravity 1.52 = 3.04 grms. taken for analysis. Took 20 c.c. permanganate solution, O.0046 x 20 =.092 grm. N_{2}O_{4}, and (.092 x 100)/3.04 = 3.02 per cent. N_{2}O_{4}. The specific gravity should be taken with an hydrometer that gives the specific gravity directly, or, if preferred, the 2 c.c. of acid may be weighed. A very good method of rapidly determining the strength of the sulphuric acid is as follows:--Weigh out in a small weighing bottle, as nearly as possible, 2.45 grms. This is best done by running in 1.33 c.c. of the acid (1.33 x 1.84 = 2.447). Wash into a large Erlenmeyer flask, carefully washing out the bottle, and also the stopper, &c. Add a drop of phenol- phthalein solution and titrate, with a half normal solution of sodium hydrate (use a 100 c.c. burette). Then if 2.45 grms. exactly have been taken, the readings on the burette will equal percentages of H_{2}SO_{4} (mono-hydrate) if not, calculate thus:--2.444 grms. weighed, required 95.4 c.c. NaOH. Then-- 2.444 : 95.4 :: 2.45 : _x_ = 95.64 per cent. H_{2}SO_{4}. It has been proposed to free nitric acid from the oxides of nitrogen by blowing compressed air through it, and thus driving the gases in solution out. The acid was contained in a closed lead tank, from which the escaping fumes were conducted into the chimney shaft, and on the bottom of which was a lead pipe, bent in the form of a circle, and pierced with holes, through which the compressed air was made to pass; but the process was not found to be of a very satisfactory nature, and it is certainly better not to allow the formation of these compounds in the manufacture of the acid in the first instance. Another plan, however, is to heat the acid gently, and thus drive out the nitrous gases. Both processes involve loss of nitric acid. Having obtained nitric and sulphuric acids as pure as possible, the next operation is to mix them. This is best done by weighing the carboys in which the acids are generally stored before the acids are drawn off into them from the condensers, and keeping their weights constantly attached to them by means of a label. It is then a simple matter to weigh off as many carboys of acid as may be required for any number of mixings, and subtract the weights of the carboys. The two acids should, after being weighed, be poured into a tank and mixed, and subsequently allowed to flow into an acid egg or montjus, to be afterwards forced up to the nitrating house in the danger area. The montjus or acid egg is a strong cast-iron tank, of either an egg shape, or a cylinder with a round end. If of the former shape, it would lie on its side, and upon the surface of the ground, and would have a manhole at one end, upon which a lid would be strongly bolted down; but if of the latter shape, the lid, of course, is upon the top, and the montjus itself is let into the ground. In either case, the principle is the same. One pipe, made of stout lead, goes to the bottom, and another just inside to convey the compressed air, the acids flowing away as the pressure is put on, just as blowing down one tube of an ordinary wash- bottle forces the water up the other tube to the jet. The pressure necessarily will, of course, vary immensely, and will depend upon the height to which the acid has to be raised and the distance to be traversed. The mixed acids having been forced up to the danger area, and to a level higher than the position of the nitrating house, should, before being used, be allowed to cool, and leaden tanks of sufficient capacity to hold at least enough acid for four or five nitrations should be placed in a wooden house upon a level at least 6 or 7 feet above the nitrating house. In this house also should be a smaller lead tank, holding, when filled to a certain mark, just enough of the mixed acids for one nitration. The object of this tank is, that as soon as the man in charge knows that the last nitration is finished, he refills this smaller tank (which contains just enough of the mixed acids), and allows its contents to flow down into the nitrating house and into the nitrator, ready for the next nitration. The nitration is usually conducted in a vessel constructed of lead, some 4 feet wide at the bottom, and rather less at the top, and about 4 feet or so high. The size, of course, depends upon the volume of the charge it is intended to nitrate at one operation, but it is always better that the tank should be only two-thirds full. A good charge is 16 cwt. of the mixed acids, in the proportion of three to five; that is, 6 cwt. of nitric acid, and 10 cwt. of sulphuric acid, and 247 lbs. of glycerine. Upon reference to the equation showing the formation of nitro-glycerine, it will be seen that for every 1 lb. of glycerine 2.47 lbs. of nitro- glycerine should be furnished,[A] but in practice the yield is only a little over 2 lbs., the loss being accounted for by the unavoidable formation of some of the lower nitrate of glycerine (the mono-nitrate), which afterward dissolves in the washing waters. The lead tank (Fig. 5) is generally cased in woodwork, with a platform in front for the man in charge of the nitrating to stand upon, and whence to work the various taps. The top of the tank is closed in with a dome of lead, in which is a small glass window, through which the progress of the nitrating operation can be watched. From the top of this dome is a tube of lead which is carried up through the roof of the building. It serves as a chimney to carry off the acid fumes which are given off during the nitration. The interior of this tank contains at least three concentric spirals of at least 1-inch lead pipe, through which water can be made to flow during the _whole_ operation of nitrating. Another lead pipe is carried through the dome of the tank, as far as the bottom, where it is bent round in the form of a circle. Through this pipe, which is pierced with small holes, about 1 inch apart, compressed air is forced at a pressure of about 60 lbs. in order to keep the liquids in a state of constant agitation during the whole period of nitration. There must also be a rather wide pipe, of say 2 inches internal diameter, carried through the dome of the tank, which will serve to carry the mixed acid to be used in the operation into the tank. There is still another pipe to go through the dome, viz., one to carry the glycerine into the tank. This need not be a large bore pipe, as the glycerine is generally added to the mixed acids in a thin stream (an injector is often used). [Footnote A: Thus if 92 lbs. glycerine give 227 lbs. nitro-glycerine, (277 x 1)/92 = 2.47 lbs.] [Illustration: FIG. 5.--TOP OF NITRATOR. _A_, Fume Pipe; _B_, Water Pipes for Cooling; _C_, Acid Mixture Pipe; _E_, Compressed Air; _G_, Glycerine Pipe and Funnel; _T_, Thermometer; _W_, Window.] Before the apparatus is ready for use, it requires to have two thermometers fixed, one long one to reach to the bottom of the tank, and one short one just long enough to dip under the surface of the acids. When the tank contains its charge, the former gives the temperature of the bottom, and the latter of the top of the mixture. The glycerine should be contained in a small cistern, fixed in some convenient spot upon the wall of the nitrating house, and should have a pipe let in flush with the bottom, and going through the dome of the nitrating apparatus. It must of course be provided with a tap or stop-cock, which should be placed just above the point where the pipe goes through the lead dome. Some method of measuring the quantity of glycerine used must be adopted. A gauge-tube graduated in inches is a very good plan, but it is essential that the graduations should be clearly visible to the operator upon the platform in front of the apparatus. A large tap made of earthenware (and covered with lead) is fixed in the side of the nitrating tank just above the bottom, to run off the charge after nitration. This should be so arranged that the charge may be at option run down the conduit to the next house or discharged into a drowning tank, which may sometimes be necessary in cases of decomposition. The drowning tank is generally some 3 or 4 yards long and several feet deep, lined with cement, and placed close outside the building. The apparatus having received a charge of mixed acids, the water is started running through the pipes coiled inside the tank, and a slight pressure of compressed air is turned on,[A] to mix the acids up well before starting. The nitration should not be commenced until the two thermometers register a temperature of 18° C. The glycerine tap is then partially opened, and the glycerine slowly admitted, and the compressed air turned on full, until the contents of the apparatus are in a state of very brisk agitation. A pressure of about 40 lbs. is about the minimum (if 247 lbs. of glycerine and 16 cwt. of acids are in the tank). If the glycerine tube is fitted with an injector, it may be turned on almost at once. The nitration will take about thirty minutes to complete, but the compressed air and water should be kept on for an additional ten minutes after this, to give time for all the glycerine to nitrate. The temperature should be kept as low as possible (not above 18° C.). [Footnote A: At the Halton Factory, Germany, cylinders of compressed carbon dioxide are connected with the air pipes so that in the event of a failure of the air supply the stirring can be continued with this gas if necessary.] The chief points to attend to during the progress of the nitration are-- 1. The temperature registered by the two thermometers. 2. The colour of the nitrous fumes given off (as seen through the little window in the dome of the apparatus). 3. The pressure of the compressed air as seen from a gauge fixed upon the air pipe just before it enters the apparatus. 4. The gauge showing the quantity of glycerine used. The temperature, as shown by either of the two thermometers, should not be at any time higher than 25° C. If it rises much above this point, the glycerine should be at once shut off, and the pressure of air increased for some few minutes until the temperature falls, and no more red fumes are given off. The nitration being finished, the large earthenware tap at the bottom of the tank is opened, and the charge allowed to flow away down the conduit to the next building, i.e., to the separator. The nitrating house is best built of wood, and should have a close-boarded floor, which should be kept scrupulously clean, and free from grit and sand. A wooden pail and a sponge should be kept in the house in order that the workman may at once clean up any mess that may be made, and a small broom should be handy, in order that any sand, &c., may be at once removed. It is a good plan for the nitrator to keep a book in which he records the time of starting each nitration, the temperature at starting and at the finish, the time occupied, and the date and number of the charge, as this enables the foreman of the danger area at any time to see how many charges have been nitrated, and gives him other useful information conducive to safe working. Edward Liebert has devised an improvement in the treatment of nitro-glycerine. He adds ammonium sulphate or ammonium nitrate to the mixed acids during the operation of nitrating, which he claims destroys the nitrous acid formed according to the equation-- (NH_{4})_{2}SO_{4} + 2HNO_{3} = H_{2}SO_{4} + 2N_{2} + 4H_{2}O. I am not aware that this modification of the process of nitration is in use at the present time. The newly made charge of nitro-glycerine, upon leaving the nitrating house, flows away down the conduit, either made of rubber pipes, or better still, of woodwork, lined with lead and covered with lids made of wood (in short lengths), in order that by lifting them at any point the condition of the conduit can be examined, as this is of the greatest importance, and the conduit requires to be frequently washed out and the sulphate of lead removed. This sulphate always contains nitro-glycerine, and should therefore be burnt in some spot far removed from any danger building or magazine, as it frequently explodes with considerable violence. [Illustration: FIG. 6.--SMALL NITRATOR. _N_, Tap for Discharging; _P_, Water Pipes; _T_, Thermometer; _W_, Windows; _P'_, Glycerine Pipe.] In works where the manufacture of nitro-glycerine is of secondary importance, and some explosive containing only perhaps 10 per cent. of nitroglycerine is manufactured, and where 50 or 100 lbs. of glycerine are nitrated at one time, a very much smaller nitrating apparatus than the one that has been already described will be probably all that is required. In this case the form of apparatus shown in Fig. 6 will be found very satisfactory. It should be made of stout lead (all lead used for tanks, &c., must be "chemical lead"), and may be made to hold 50 or 100 lbs. as found most convenient. This nitrator can very well be placed in the same house as the separator; in fact, where such a small quantity of nitro- glycerine is required, the whole series of operations, nitrating, separation, and washing, &c., may very well be performed in the same building. It will of course be necessary to place the nitrator on a higher level than the separator, but this can easily be done by having platforms of different heights, the nitration being performed upon the highest. The construction of this nitrator is essentially the same as in the larger one, the shape only being somewhat different. Two water coils will probably be enough, and one thermometer. It will not be necessary to cover this form in with woodwork. ~The Nathan Nitrator.~[A]--This nitrator is the patent of Lt. Col. F.L. Nathan and Messrs J.M. Thomson and W. Rintoul of Waltham Abbey, and will probably before long entirely supersede all the other forms of nitrator on account of its efficiency and economy of working. With this nitrator it is possible to obtain from 2.21 to 2.22 parts of nitro-glycerine from every 1 part of glycerine. The apparatus is so arranged that the nitration of the glycerine, the separation of nitro-glycerine produced, as well as the operation of "after-separation," are carried out in one vessel. The usual nitrating vessel is provided with an acid inlet pipe at the bottom, and a glass separation cylinder with a lateral exit or overflow pipe at the top. This cylinder is covered by a glass hood or bell jar during nitration to direct the escaping air and fumes into a fume pipe where the flow of the latter may be assisted by an air injector. The lateral pipe in the separation cylinder is in connection with a funnel leading to the prewash tank. The drawing (Fig. 7) shows a vertical section of the apparatus; _a_ is the nitrating vessel of usual construction, having at the bottom an acid inlet pipe with three branches, one leading to the de-nitrating plant, _c_ leading to the drowning tank, and _d_, which extends upwards and has two branches, _e_ leading to the nitrating acids tank, and _f_ to the waste acid tank. On the sloped bottom of the nitrating vessel _a_ lies a coil _g_ of perforated pipe for blowing air, and there are in the vessel several coils _h_, three shown in the drawing, for circulation of cooling water. At the top of the vessel there is a glass cylinder _i_, having a lateral outlet _j_ directed into the funnel mouth of a pipe _k_ leading to the prewash tank. Over the cylinder _i_ is a glass globe _l_, into which opens a pipe _m_ for leading off fumes which may be promoted by a compressed air jet from a pipe _r_ operating as an injector. Into an opening of the glass dome _l_ is inserted a vessel _n_, which is connected by a flexible pipe _p_ to the glycerine tank, and from the bottom of _n_, which is perforated and covered with a disc perforated with holes registering with those through the bottom, this disc being connected by a stem with a knob _q_ by which it can be turned so as to throttle or cut off passage of glycerine through the bottom. _s_ is a thermometer for indicating the temperature of the contents of the vessel. [Footnote A: Eng. Pat. 15,983, August 1901.] [Illustration: FIG. 7.--NATHAN'S NITRATOR FOR NITRO-GLYCERINE. (_a_) Nitrating Vessel; (_b_) to Separating Vessel; (_c_) to Drowning Tank; (_e_) Nitrating Acids enter (_f_) to the Waste Acids; (_g_) Coils for Compressed Air; (_h_) Pipes for Cooling Water; (_i_) Glass Cylinder; (_j_) Outlet to _k_; (_k_) leading to Prewash Tank; (_l_) Glass Dome; (_m_) Pipe to lead off for Escape of Fumes; (_n_) Vessel; (_p_) Pipe conveying Glycerine; (_q_) Knob to turn off Glycerine; (_r_) Compressed Air Jet; (_s_) Thermometer.] In operating with this apparatus the nitrating acid is introduced into the nitrating vessel by opening the cock of the pipe _e_. The glycerine is then run in by introducing _n_ and opening the valve at its bottom, the contents of the vessel being agitated by air blown through the perforations of the pipe _g_. When the glycerine is all nitrated and the temperature has slightly fallen, the circulation of the water through the coils _h_ and the air-stirring are stopped, and the glycerine supply vessel _n_ is removed. The nitro-glycerine as it separates from the acids is raised by introducing by the pipe _f_ waste acid from a previous charge, this displacing the nitro-glycerine upwards and causing it to flow by the outlet, _j_ and pipe _k_ to the prewash tank. When nearly all the nitro-glycerine has been separated in this manner the acids in the apparatus may be run off by the pipe _b_ to an after separating vessel for further settling, thus leaving the apparatus free for another nitration, or the nitrating vessel itself may be used as an after separating bottle displacing the nitro-glycerine with waste acid as it rises to the top, or skimming off in the usual manner. When the separation of the nitro- glycerine is complete the waste acid is run off and denitrated as usual, a portion of it being reserved for the displacement of the nitro-glycerine in a subsequent operation. In a further patent (Eng. Pat. 3,020, 1903) the authors propose with the object of preventing the formation and separation of nitro-glycerine in the waste acids, after the nitro-glycerine initially formed in the nitrating vessel has been separated and removed, to add a small quantity of water to the waste acids; this is carried out as follows. A relatively small quantity of water is added, and this prevents all further separation of nitro-glycerine, and at the same time the strength of the waste acids is so slightly reduced that their separation and re-concentration are not affected. "After-separation" is thus done away with, and the nitro- glycerine plant simplified and its output increased. After nitration separation is commenced at a temperature such that when all the displacing acid has been added, and the separation of the nitro-glycerine is complete, the temperature of the contents of the nitrating vessel shall not be lower than 15° C. A sufficient quantity of the displacing acid is then run off through the waste-acid cock to allow of the remaining acids being air-stirred without splashing over the top. A small quantity of water, from 2 to 3 per cent. according to strength of acid; if waste consists of sulphuric acid (monohydrate), 62 per cent.; nitric acid (anhydrous), 33 per cent. and water 5 per cent.; temperature 15° C., then 2 per cent. of water is added; if waste acids contain less than 4 per cent. of water of temperature lower than 15° C., from 3 to 5 per cent. of water may have to be added. The water is added slowly through the separator cylinder, and the contents of the nitrator air-stirred, but not cooled, the temperature being allowed to rise slowly and regularly as the water is added--usually about 3° C. for each per cent. of water added. When air-agitation has been stopped, the acids are kept at rest for a short time, in order to allow of any small quantity of initially formed nitro-glycerine adhering to the coils and sides of the vessel rising to the top. When this has been separated by displacement, the acids are ready for denitration, or can be safely stored without further precaution. ~Separation.~--The nitro-glycerine, together with the mixed acids, flows from the nitrating house to the separating house, which must be on a lower level than the former. The separating house contains a large lead-lined tank, closed in at the top with a wooden lid, into which a lead pipe of large bore is fixed, and which is carried up through the roof of the building, and acts as a chimney to carry off any fumes. A little glass window should be fixed in this pipe in order that the colour of the escaping fumes may be seen. The conduit conveying the nitro-glycerine enters the building close under the roof, and discharges its contents into the tank through the pipe G (Fig. 8). The tank is only about two-thirds filled by the charge. There is in the side of the tank a small window of thick plate glass, which enables the workman to see the level of the charge, and also to observe the progress of the separation, which will take from thirty minutes to one hour. The tank should be in connection with a drowning tank, as the charge sometimes gets very dangerous in this building. It must also be connected by a conduit with the filter house, and also to the secondary separator by another conduit. The tank should also be fitted with a compressed air pipe, bent in the form of a loop. It should lie upon the bottom of the vat. The object of this is to mix up the charge in case it should get too hot through decomposition. A thermometer should of course be fixed in the lid of the tank, and its bulb should reach down to the middle of the nitro-glycerine (which rests upon the surface of the mixed acids, the specific gravity of the nitro-glycerine being 1.6, and that of the waste acids 1.7; the composition of the acids is now 11 per cent. HNO_{3}, 67 per cent. H_{2}SO_{4}, and 22 per cent. water), and the temperature carefully watched. [Illustration: FIG. 8.--SEPARATOR. _A_, Compressed Air Pipes; _G_, Nitro- glycerine enters from Nitrator; _N_, Nitro-glycerine to _P_; _L_, Lantern Window; _W_, Window in Side; _S_, Waste Acids to Secondary Separator; _T_, Tap to remove last traces of Nitro-glycerine; _P_, Lead Washing Tank; _A_, Compressed Air; _W_, Water Pipe; _N_, Nitro-glycerine from Separator.] If nothing unusual occurs, and it has not been necessary to bring the compressed air into use, and so disturb the process of separation, the waste acids may be run away from beneath the nitro-glycerine, and allowed to flow away to the secondary separator, where any further quantity of nitro-glycerine that they contain separates out after resting for some days. The nitro-glycerine itself is run into a smaller tank in the same house, where it is washed three or four times with its own bulk of water, containing about 3 lbs. of carbonate of soda to neutralise the remaining acid. This smaller tank should contain a lead pipe, pierced and coiled upon the bottom, through which compressed air may be passed, in order to stir up the charge with the water and soda. After this preliminary washing, the nitro-glycerine is drawn off into indiarubber buckets, and poured down the conduit to the filter house. The wash waters may be sent down a conduit to another building, in order to allow the small quantity of nitro-glycerine that has been retained in the water as minute globules to settle, if thought worth the trouble of saving. This, of course, will depend upon the usual out-turn of nitro-glycerine in a day, and the general scale of operations. [Illustration: FIG. 9.--FILTERING AND WASHING PLANT. _W_, Lead Washing Tank; _WP_, Water Pipe; _L_, Lid; _S_, Nitro-glycerine from Separator; _A, B, C_, Filtering Tanks; _B2_, Indiarubber Bucket.] ~Filtering and Washing.~--The filter house (Fig. 9), which must of course be again on a somewhat lower level than the separating house, must be a considerably larger building than either the nitrating or separating houses, as it is always necessary to be washing some five or six charges at the same time. Upon the arrival of the nitro-glycerine at this house, it first flows into a lead-lined wooden tank (W), containing a compressed air pipe, just like the one in the small tank in the separating house. This tank is half filled with water, and the compressed air is turned on from half to a quarter of an hour after the introduction of the charge. The water is then drawn off, and fresh water added. Four or five washings are generally necessary. The nitro-glycerine is then run into the next tank (A), the top of which is on a level with the bottom of the first one. Across the top of this tank is stretched a frame of flannel, through which the nitroglycerine has to filter. This removes any solid matters, such as dirt or scum. Upon leaving this tank, it passes through a similar flannel frame across another tank (B), and is finally drawn off by a tap in the bottom of the tank into rubber buckets. The taps in these tanks are best made of vulcanite. At this stage, a sample should be taken to the laboratory and tested. If the sample will not pass the tests, which is often the case, the charge must be rewashed for one hour, or some other time, according to the judgment of the chemist in charge. In the case of an obstinate charge, it is of much more avail to wash a large number of times with small quantities of water, and for a short time, than to use a lot of water and wash for half an hour. Plenty of compressed air should be used, as the compound nitric ethers which are formed are thus got rid of. As five or six charges are often in this house at one time, it is necessary to have as many tanks arranged in tiers, otherwise one or two refractory charges would stop the nitrating house and the rest of the nitro-glycerine plant. The chief causes of the washed material not passing the heat test are, either that the acids were not clean, or they contained objectionable impurities, or more frequently, the quality of the glycerine used. The glycerine used for making nitro-glycerine should conform to the following tests, some of which, however, are of greater importance than others. The glycerine should-- 1. Have minimum specific gravity at 15° C. of 1.261. 2. Should nitrify well. 3. Separation should be sharp within half an hour, without the separation of flocculent matter, nor should any white flocculent matter (due to fatty acids) be formed when the nitrated glycerine is thrown into water and neutralised with carbonate of soda. 4. Should be free from lime and chlorine, and contain only traces of arsenic, sulphuric acid, &c. 5. Should not leave more than 0.25 per cent. of inorganic and organic residue together when evaporated in a platinum dish without ebullition (about 160° C.) or partial decomposition. 6. Silver test fair. 7. The glycerine, when diluted one-half, should give no deposit or separation of fatty acids when nitric peroxide gas is passed through it. (Nos. 1, 2, 3, and 5 are the most essential.) The white flocculent matter sometimes formed is a very great nuisance, and any sample of glycerol which gives such a precipitate when tried in the laboratory should at once be rejected, as it will give no end of trouble in the separating house, and also in the filter house, and it will be very difficult indeed to make the nitro-glycerine pass the heat test. The out- turn of nitro-glycerine also will be very low. The trouble will show itself chiefly in the separating operation. Very often 2 or 3 inches will rise to the surface or hang about in the nitro-glycerine, and at the point of contact between it and the mixed acids, and will afterwards be very difficult to get rid of by filtration. The material appears to be partly an emulsion of the glycerine, and partly due to fatty acids, and as there appears to be no really satisfactory method of preventing its formation, or of getting rid of it, the better plan is not to use any glycerine for nitrating that has been found by experiment upon the laboratory scale to give this objectionable matter. One of the most useful methods of testing the glycerine, other than nitrating, is to dilute the sample one-half with water, and then to pass a current of nitric peroxide gas through it, when a flocculent precipitate of elaïdic acid (less soluble in glycerine than the original oleic acid) will be formed. Nitrogen peroxide, N_{2}O_{4}, is best obtained by heating dry lead nitrate (see Allen, "Commercial Organic Analysis," vol. ii., 301). When a sample of nitro-glycerine is brought to the laboratory from the filter house, it should first be examined to see that it is not acid.[A] A weak solution of Congo red or methyl orange may be used. If it appears to be decidedly alkaline, it should be poured into a separating funnel, and shaken with a little distilled water. This should be repeated, and the washings (about 400 c.c.) run into a beaker, a drop of Congo red or methyl orange added, and a drop or so of N/2 hydrochloric acid added, when it should give, with two or three drops at most, a blue colour with the Congo red, or pink with the methyl orange, &c. The object of this test is to show that the nitro-glycerine is free from any excess of soda, i.e., that the soda has been properly washed out, otherwise the heat test will show the sample to be better than it is. The heat test must also be applied. [Footnote A: A. Leroux, _Bul. Soc. Chim. de Bel._, xix., August 1905, contends that experience does not warrant the assumption that free acid is a source of danger in nitro-glycerine or nitro-cellulose; free alkali, he states, promotes their decomposition.] Upon leaving the filter house, where it has been washed and filtered, and has satisfactorily passed the heat test, it is drawn off from the lowest tank in indiarubber buckets, and poured down the conduit leading to the precipitating house, where it is allowed to stand for a day, or sometimes longer, in order to allow the little water it still contains to rise to the surface. In order to accomplish this, it is sufficient to allow it to stand in covered-in tanks of a conical form, and about 3 or 4 feet high. In many works it is previously filtered through common salt, which of course absorbs the last traces of water. It is then of a pale yellow colour, and should be quite clear, and can be drawn off by means of a tap (of vulcanite), fixed at the bottom of the tanks, into rubber buckets, and is ready for use in the preparation of dynamite, or any of the various forms of gelatine compounds, smokeless powders, &c., such as cordite, ballistite, and many others. Mikolajezak (_Chem. Zeit._, 1904, Rep. 174) states that he has prepared mono- and di-nitro-glycerine, and believes that the latter compound will form a valuable basis for explosives, as it is unfreezable. It is stated to be an odourless, unfreezable oil, less sensitive to percussion, friction, and increase of temperature, and to possess a greater solvent power for collodion-cotton than ordinary nitro-glycerine. It can thus be used for the preparation of explosives of high stability, which will maintain their plastic nature even in winter. The di-nitro-glycerine is a solvent for tri-nitro-glycerine, it can therefore be mixed with this substance, in the various gelatine explosives in order to lower the freezing point. ~The Waste Acids.~--The waste acids from the separating house, from which the nitro-glycerine has been as completely separated as possible, are run down the conduit to the secondary separator, in order to recover the last traces of nitro-glycerine that they contain. The composition of the waste acids is generally somewhat as follows:--Specific gravity, 1.7075 at 15° C.; sulphuric acid, 67.2 per cent.; nitric acid, 11.05 per cent.; and water, 21.7 per cent., with perhaps as much as 2 per cent. of nitric oxide, and of course varying quantities of nitro-glycerine, which must be separated, as it is impossible to run this liquid away (unless it can be run into the sea) or to recover the acids by distillation as long as it contains this substance. The mixture, therefore, is generally run into large circular lead-lined tanks, covered in, and very much like the nitrating apparatus in construction, that is, they contain worms coiled round inside, to allow of water being run through to keep the mixture cool, and a compressed air pipe, in order to agitate the mixture if necessary. The top also should contain a window, in order to allow of the interior being seen, and should have a leaden chimney to carry off the fumes which may arise from decomposition. It is also useful to have a glass tube of 3 or 4 inches in diameter substituted for about a foot of the lead chimney, in order that the man on duty can at any time see the colour of the fumes arising from the liquid. There should also be two thermometers, one long one reaching to the bottom of the tank, and one to just a few inches below the surface of the liquid. The nitro-glycerine, of course, collects upon the surface, and can be drawn off by a tap placed at a convenient height for the purpose. The cover of the tank is generally conical, and is joined to a glass cylinder, which is cemented to the top of this lead cover, and also to the lead chimney. In this glass cylinder is a hole into which fits a ground glass stopper, through which the nitro-glycerine can be drawn off. There will probably never be more than an inch of nitro-glycerine at the most, and seldom that. It should be taken to the filter house and treated along with another charge. The acids themselves may either be run to waste, or better treated by some denitration plant. This house probably requires more attention than any other in the danger area, on account of the danger of the decomposition of the small quantities of nitro-glycerine, which, as it is mixed with such a large quantity of acids and water, is very apt to become hot, and decomposition, which sets up in spots where a little globule of nitro-glycerine is floating, surrounded by acids that gradually get hot, gives off nitrous fumes, and perhaps explodes, and thus causes the sudden explosion of the whole. The only way to prevent this is for the workman in charge to look at the thermometers _frequently_, and at the colour of the escaping fumes, and if he should notice a rise of temperature or any appearance of red fumes, to turn on the water and air, and stir up the mixture, when probably the temperature will suddenly fall, and the fumes cease to come off. The cause of explosions in this building is either the non-attention of the workmen in charge, or the bursting of one of the water pipes, by which means, of course, the water, finding its way into the acids, causes a sudden rise of temperature. If the latter of these two causes should occur, the water should at once be shut off and the air turned on full, but if it is seen that an explosion is likely to occur, the tank should at once be emptied by allowing its contents to run away into a drowning tank placed close outside the house, which should be about 4 feet deep, and some 16 feet long by 6 feet wide; in fact, large enough to hold a considerable quantity of water. But this last course should only be resorted to as a last extremity, as it is extremely troublesome to recover the small quantity of nitro-glycerine from the bottom of this tank, which is generally a bricked and cemented excavation some few yards from the house. It has been proposed to treat these waste acids, containing nitro- glycerine, in Mr M. Prentice's nitric acid retort. In this case they would be run into the retort, together with nitrate of soda, in a fine stream, and the small quantity of nitro-glycerine, coming into contact with the hot mixture already in the retort, would probably be at once decomposed. This process, although not yet tried, promises to be a success. Several processes have been used for the denitration of these acids. ~Treatment of the Waste Acid from the Manufacture of Nitro-Glycerine and Gun-Cotton.~--The composition of these acids is as follows:-- Nitro-glycerine and Gun-cotton Waste Acid. Sulphuric acid 70 per cent. 78 per cent. Nitric acid 10 " 12 " Water 20 " 10 " The waste acid from the manufacture of gun-cotton is generally used direct for the manufacture of nitric acid, as it contains a fairly large amount of sulphuric acid, and the small amount of nitro-cellulose which it also generally contains decomposes gradually and without explosion in the retort. Nitric acid may be first distilled off, the resulting sulphuric acid being then added to the equivalent amount of nitrate of soda. Nitric acid is then distilled over and condensed in the usual way. Very often, however, the waste acid is added direct to the charge of nitrate without previously eliminating the nitric acid. The treatment of the waste acid from the manufacture of nitro-glycerine is somewhat different. The small amount of nitro-glycerine in this acid must always be eliminated. This is effected either by allowing the waste acid to stand for at least twenty- four hours in a big vessel with a conical top, where all the nitro- glycerine which will have separated to the surface is removed by skimming; or, better still, the "watering down process" of Col. Nathan may be employed. In Nathan's nitrator every existing trace of nitro-glycerine is separated from the acids in a few hours after the nitration, and any further formation of nitro-glycerine is prevented by adding about 2 per cent. of water to the waste acids, which are kept agitated during the addition. The waste acid, now free from nitro-glycerine, but which may still contain organic matter, is denitrated by bringing it into contact with a jet of steam. The waste acid is passed in a small stream down through a tower of acid-resisting stoneware (volvic stone), which is closely packed with earthenware, and at the bottom of which is the steam jet. Decomposition proceeds as the acid meets the steam, nitric and nitrous acids are disengaged and are passed out at the top of the tower through a pipe to a series of condensers and towers, where the nitric acid is collected. The nitrous acid may be converted into nitric acid by introducing a hot compressed air jet into the gases before they pass into the condensers. Weak sulphuric acid of sp. gr. 1.6 collects in a saucer in which the tower stands, and is then passed through a cooling worm. The weak sulphuric acid, now entirely free from nitric and nitrous acids, may be concentrated to sp. gr. 1.842 and 96 per cent. H_{2}SO_{4} by any of the well-known processes, e.g., Kessler, Webb, Benker, Delplace, &c., and it may be used again in the manufacture of nitro-glycerine or gun-cotton. Two points in the manufacture of nitro-glycerine are of the greatest importance, viz., the purity of the glycerine used, and the strength and purity of the acids used in the nitration. With regard to the first of these, great care should be taken, and a complete analysis and thorough examination, including a preliminary experimental nitration, should always be instituted. As regards the second, the sulphuric acid should not only be strong (96 per cent.), but as free from impurities as possible. With the nitric acid, which is generally made at the explosive works where it is used, care must be taken that it is as strong as possible (97 per cent. and upwards). This can easily be obtained if the plant designed by Mr Oscar Guttmann[A] is used. Having worked Mr Guttmann's plant for some time, I can testify as to its value and efficiency. [Footnote A: "The Manufacture of Nitric Acid," _Jour. Soc. Chem. Ind._, March 1893.] Another form of nitric acid plant, which promises to be of considerable service to the manufacturer of nitric acid for the purpose of nitrating, is the invention of the late Mr Manning Prentice, of Stowmarket. Through the kindness of Mr Prentice, I visited his works to see the plant in operation. It consists of a still, divided into compartments or chambers in such a manner that the fluid may pass continuously from one to the other. The nitric acid being continuously separated by distillation, the contents of each division vary--the first containing the full proportion of nitric acid, and each succeeding one less of the nitric acid, until from the overflow of the last one the bisulphate of soda flows away without any nitric acid. The nitrate of soda is placed in weighed quantities in the hopper, whence it passes to the feeder. The feeder is a miniature horizontal pug-mill, which receives the streams of sulphuric acid and of nitrate, and after thoroughly mixing them, delivers them into the still, where, under the influence of heat, they rapidly become a homogeneous liquid, from which nitric acid continuously distils. Mr Prentice says: "I may point out that while the ordinary process of making nitric acid is one of fractional distillation by time, mine is fractional distillation by space." "Instead of the operation being always at the same point of space, but differing by the successive points of time, I arrange for the differences to take place at different points of space, and these differences exist at one and the same points of time." It is possible with this plant to produce the full product of nitric acid of a gravity of 1.500, or to obtain the acid of varying strengths from the different still-heads. One of these stills, capable of producing about 4 tons of nitric acid per week, weighs less than 2 tons. It is claimed that there is by their use a saving of more than two-thirds in fuel, and four- fifths in condensing plant. Further particulars and illustrations will be found in Mr Prentice's paper (_Journal of the Society of Chemical Industry_, 1894, p. 323). CHAPTER III. _NITRO-CELLULOSE, &c._ Cellulose Properties--Discovery of Gun-Cotton--Properties of Gun-Cotton-- Varieties of Soluble and Insoluble Gun-Cottons--Manufacture of Gun-Cotton-- Dipping and Steeping--Whirling out the Acid--Washing--Boiling--Pulping-- Compressing--The Waltham Abbey Process--Le Bouchet Process--Granulation of Gun-Cotton--Collodion-Cotton--Manufacture--Acid Mixture used--Cotton used, &c.--Nitrated Gun-Cotton--Tonite--Dangers in Manufacture of Gun-Cotton-- Trench's Fire-Extinguishing Compound--Uses of Collodion-Cotton--Celluloid-- Manufacture, &c.--Nitro-Starch, Nitro-Jute, and Nitro-Mannite. ~The Nitro-Celluloses.~--The substance known as cellulose forms the groundwork of vegetable tissues. The cellulose of the woody parts of plants was at one time supposed to be a distinct body, and was called lignine, but they are now regarded as identical. The formula of cellulose is (C_{6}H_{10}O_{6})_{X}, and it is generally assumed that the molecular formula must be represented by a multiple of the empirical formula, C_{12}H_{20}O_{10} being often regarded as the minimum. The assumption is based on the existence of a penta-nitrate and the insoluble and colloidal nature of cellulose. Green (_Zeit. Farb. Text. Ind._, 1904, 3, 97) considers these reasons insufficient, and prefers to employ the single formula C_{6}H_{10}O_{5}. Cellulose can be extracted in the pure state, from young and tender portions of plants by first crushing them, to rupture the cells, and then extracting with dilute hydrochloric acid, water, alcohol, and ether in succession, until none of these solvents remove anything more. Fine paper or cotton wool yield very nearly pure cellulose by similar treatment. Cellulose is a colourless, transparent mass, absolutely insoluble in water, alcohol, or ether. It is, however, soluble in a solution of cuprammoniac solution, prepared from basic carbonate or hydrate of copper and aqueous ammonia. The specific gravity of cellulose is 1.25 to 1.45. According to Schulze, its elementary composition is expressed by the percentage numbers:-- Carbon 44.0 per cent. 44.2 per cent. Hydrogen 6.3 " 6.4 " Oxygen 49.7 " 49.4 " These numbers represent the composition of the ash free cellulose. Nearly all forms of cellulose, however, contain a small proportion of mineral matters, and the union of these with the organic portion of the fibre or tissue is of such a nature that the ash left on ignition preserves the form of the original. "It is only in the growing point of certain young shoots that the cellulose tissue is free from mineral constituents" (Hofmeister). Cellulose is a very inert body. Cold concentrated sulphuric acid causes it to swell up, and finally dissolves it, forming a viscous solution. Hydrochloric acid has little or no action, but nitric acid has, and forms a series of bodies known as nitrates or nitro-celluloses. Cellulose has some of the properties of alcohols, among them the power of forming ethereal salts with acids. When cellulose in any form, such as cotton, is brought into contact with strong nitric acid at a low temperature, a nitrate or nitro product, containing nitryl, or the NO_{2} group, is produced. The more or less complete replacement of the hydroxylic hydrogen by NO_{2} groups depends partly on the concentration of the nitric acid used, partly on the duration of the action. If the most concentrated nitric and sulphuric acids are employed, and the action allowed to proceed for some considerable time, the highest nitrate, known as hexa-nitro- cellulose or gun-cotton, C_{12}H_{14}O_{4}(O.NO_{2})_{6}, will be formed; but with weaker acids, and a shorter exposure to their action, the tetra and penta and lower nitrates will be formed.[A] [Footnote A: The paper by Prof. Lunge, _Jour. Amer. Chem. Soc._, 1901, 23[8], 527-579, contains valuable information on this subject.] Besides the nitrate, A. Luck[A] has proposed to use other esters of cellulose, such as the acetate, benzoate, or butyrate. It is found that cellulose acetate forms with nitro-glycerine a gelatinous body without requiring the addition of a solvent. A sporting powder is proposed composed of 75 parts of cellulose nitrate (13 per cent. N.) mixed with 13 parts of cellulose acetate. [Footnote A: Eng. Pat. 24,662, 22nd November 1898.] The discovery of gun-cotton is generally attributed to Schönbein (1846), but Braconnot (in 1832) had previously nitrated starch, and six years later Pelouse prepared nitro-cotton and various other nitro bodies, and Dumas nitrated paper, but Schönbein was apparently the first chemist to use a mixture of strong nitric and sulphuric acids. Many chemists, such as Piobert in France, Morin in Russia, and Abel in England, studied the subject; but it was in Austria, under the auspices of Baron Von Lenk, that the greatest progress was made. Lenk used cotton in the form of yarn, made up into hanks, which he first washed in a solution of potash, and then with water, and after drying dipped them in the acids. The acid mixture used consisted of 3 parts by weight of sulphuric to 1 part of nitric acid, and were prepared some time before use. The cotton was dipped one skein at a time, stirred for a few minutes, pressed out, steeped, and excess of acid removed by washing with water, then with dilute potash, and finally with water. Von Lenk's process was used in England at Faversham (Messrs Hall's Works), but was given up on account of an explosion (1847). Sir Frederick Abel, working at Stowmarket and Waltham Abbey, introduced several very important improvements into the process, the chief among these being pulping. Having traced the cause of its instability to the presence of substances caused by the action of the nitric acid on the resinous or fatty substances contained in the cotton fibre, he succeeded in eliminating them, by boiling the nitro-cotton in water, and by a thorough washing, after pulping the cotton in poachers. Although gun-cottons are generally spoken of as nitro-celluloses, they are more correctly described as cellulose nitrates, for unlike nitro bodies of other series, they do not yield, or have not yet done so, amido bodies, on reduction with nascent hydrogen.[A] The equation of the formation of gun-cotton is as follows:-- 2(C_{6}H_{10}O_{5}) + 6HNO_{3} = C_{12}H_{14}O_{4}(NO_{3})_{6} + 6OH_{2}. Cellulose. Nitric Acid. Gun-Cotton. Water. The sulphuric acid used does not take part in the reaction, but its presence is absolutely essential to combine with the water set free, and thus to prevent the weakening of the nitric acid. The acid mixture used at Waltham Abbey consists of 3 parts by weight of sulphuric acid of 1.84 specific gravity, and 1 part of nitric acid of 1.52 specific gravity. The same mixture is also used at Stowmarket (the New Explosive Company's Works). The use of weaker acids results in the formation of collodion- cotton and the lower nitrates generally. [Footnote A: "Cellulose," by Cross and Bevan, ed. by W.R. Hodgkinson, p. 9.] The nitrate which goes under the name of gun-cotton is generally supposed to be the hexa-nitrate, and to contain 14.14 per cent. of nitrogen; but a higher percentage than 13.7 has not been obtained from any sample. It is almost impossible (at any rate upon the manufacturing scale) to make pure hexa-nitro-cellulose or gun-cotton; it is certain to contain several per cents. of the soluble forms, i.e., lower nitrates. It often contains as much as 15 or 16 per cent., and only from 13.07[A] to 13.6 per cent. of nitrogen. [Footnote A: Mr J.J. Sayers, in evidence before the court in the "Cordite Case," says he found 15.2 and 16.1 per cent. soluble cotton, and 13.07 and 13.08 per cent. nitrogen in two samples of Waltham Abbey gun-cotton.] A whole series of nitrates of cellulose are supposed to exist, the highest member being the hexa-nitrate, and the lowest the mono-nitrate. Gun-cotton was at one time regarded as the tri-nitrate, and collodion-cotton as the di-nitrate and mono-nitrate, their respective formula being given as follows:-- Mono-nitro-cellulose C_{6}H_{9}(NO_{2})O_{5} = 6.763 per cent. nitrogen. Di-nitro-cellulose C_{6}H_{8}(NO_{2})_{2}O_{5} = 11.11 " " Tri-nitro-cellulose C_{6}H_{7}(NO_{2})_{3}O_{5} = 14.14 " " But gun-cotton is now regarded as the hexa-nitrate, and collodion-cotton as a mixture of all the other nitrates. In fact, chemists are now more inclined to divide nitro-cellulose into the soluble and insoluble forms, the reason being that it is quite easy to make a nitro-cellulose entirely soluble in a mixture of ether-alcohol, and yet containing as high a percentage of nitrogen as 12.6; whereas the di-nitrate[A] should theoretically only contain 11.11 per cent. On the other hand, it is not possible to make gun-cotton with a higher percentage of nitrogen than about 13.7, even when it does not contain any nitro-cotton that is soluble in ether-alcohol.[B] The fact is that it is not at present possible to make a nitro-cellulose which shall be either entirely soluble or entirely insoluble, or which will contain the theoretical content of nitrogen to suit any of the above formulæ for the cellulose nitrates. Prof. G. Lunge gives the following list of nitration products of cellulose:-- [Footnote A: The penta-nitrate C_{12}H_{15}O_{5}(NO_{3})_{5} = 12.75 per cent. nitrogen.] [Footnote B: In the Cordite Trial (1894) Sir F.A. Abel said, "Before 1888 there was a broad distinction between soluble and insoluble nitro- cellulose, collodion-cotton being soluble (in ether-alcohol) and gun-cotton insoluble." Sir H.E. Roscoe, "That he had been unable to make a nitro-cotton with a higher nitrogen content than 13.7." And Professor G. Lunge said, "Gun-cotton always contained soluble cotton, and _vice versa_." These opinions were also generally confirmed by Sir E. Frankland, Sir W. Crookes, Dr Armstrong, and others.] Dodeca-nitro-cellulose C_{24}H_{28}O_{20}(NO_{2})_{12} = 14.16 per cent. nitrogen. (= old tri-nitro-cellulose) Endeca-nitro-cellulose C_{24}H_{29}O_{20}(NO_{2})_{11} = 13.50 per cent. nitrogen. Deca-nitro-cellulose C_{24}H_{30}O_{20}(NO_{2})_{10} = 12.78 per cent. nitrogen. Ennea-nitro-cellulose C_{24}H_{31}O_{20}(NO_{2})_{9} = 11.98 per cent. nitrogen. Octo-nitro-cellulose C_{24}H_{32}O_{20}(NO_{2})_{8} = 11.13 per cent. nitrogen. (= old di-nitro-cellulose) Hepta-nitro-cellulose C_{24}H_{33}O_{20}(NO_{2})_{7} = 10.19 per cent. nitrogen. Hexa-nitro-cellulose C_{24}H_{34}O_{20}(NO_{2})_{6} = 9.17 per cent. nitrogen. Penta-nitro-cellulose C_{24}H_{35}O_{20}(NO_{2})_{5} = 8.04 per cent. nitrogen. Tetra-nitro-cellulose C_{24}H_{36}O_{20}(NO_{2})_{4} = 6.77 per cent. nitrogen. (= old mono-nitro-cellulose) It is not unlikely that a long series of nitrates exists. It is at any rate certain that whatever strength of acids may be used, and whatever temperature or other conditions may be present during the nitration, that the product formed always consists of a mixture of the soluble and insoluble nitro-cellulose. Theoretically 100 parts of cotton by weight should produce 218.4 parts of gun-cotton, but in practice the yield is a good deal less, both in the case of gun-cotton or collodion-cotton. In speaking of soluble and insoluble nitro-cellulose, it is their behaviour, when treated with a solution consisting of 2 parts ether and 1 of alcohol, that is referred to. There is, however, another very important difference, and that is their different solubility in nitro-glycerine. The lower nitrates or soluble form is soluble in nitro-glycerine under the influence of heat, a temperature of about 50° C. being required. At lower temperatures the dissolution is very imperfect indeed; and after the materials have been left in contact for days, the threads of the cotton can still be distinguished. The insoluble form or gun-cotton is entirely _insoluble_ in nitro-glycerine. It can, however, be made to dissolve[A] by the aid of acetone or acetic ether. Both or rather all the forms of nitro-cellulose can be dissolved in acetone or acetic ether. They also dissolve in concentrated sulphuric acid, and the penta-nitrate in nitric acid at about 80° or 90° C. [Footnote A: Or rather to form a transparent jelly.] The penta-nitrate may be obtained in a pure state by the following process, devised by Eder:--The gun-cotton is dissolved in concentrated nitric acid at 90° C., and reprecipitated by the addition of concentrated sulphuric acid. After cooling to 0° C., and mixing with a larger volume of water, the precipitated nitrate is washed with water, then with alcohol, dissolved in ether-alcohol, and again precipitated with water, when it is obtained pure. This nitrate is soluble in ether-alcohol, and slightly in acetic acid, easily in acetone, acetic ether, and methyl-alcohol, insoluble in alcohol. Strong potash (KOH) solution converts into the di-nitrate C_{12}H_{18}O_{8}(NO_{3})_{2}. The hexa-nitrate is not soluble in acetic acid or methyl-alcohol. The lower nitrates known as the tetra- and tri-nitrates are formed together when cellulose is treated with a mixture of weak acids, and allowed to remain in contact with them for a very short time (twenty minutes). They cannot be separated from one another, as they all dissolve equally in ether-alcohol, acetic ether, acetic acid, methyl-alcohol, acetone, amyl acetate, &c. As far as the manufacture of explosive bodies is concerned, the two forms of nitro-cellulose used and manufactured are gun-cotton or the hexa- nitrate (once regarded as tri-nitro-cellulose), which is also known as insoluble gun-cotton, and the soluble form of gun-cotton, which is also known as collodion, and consists of a mixture of several of the lower nitrates. It is probable that it chiefly consists, however, of the next highest nitrate to gun-cotton, as the theoretical percentage of nitrogen for this body,. the penta-nitrate, is 12.75 per cent., and analyses of commercial collodion-cotton, entirely soluble in ether-alcohol, often give as high a percentage as 12.6. We shall only describe the manufacture of the two forms known as soluble and insoluble, and shall refer to them under their better known names of gun-cotton and collodion-cotton. The following would, however, be the formulæ[A] and percentage of nitrogen of the complete series:-- Hexa-nitro-cellulose C_{12}H_{14}O_{4}(NO_{3})_{6} 14.14 per cent. nitrogen. Penta-nitro-cellulose C_{12}H_{15}O_{5}(NO_{3})_{5} 12.75 per cent. nitrogen. Tetra-nitro-cellulose C_{12}H_{16}O_{6}(NO_{3})_{4} 11.11 per cent. nitrogen. Tri-nitro-cellulose C_{12}H_{17}O_{7}(NO_{3})_{3} 9.13 per cent. nitrogen. Di-nitro-cellulose C_{12}H_{18}O_{8}(NO_{3})_{2} 7.65 per cent. nitrogen. Mono-nitrocellulose C_{12}H_{19}O_{9}(NO_{3}) 3.80 per cent. nitrogen. [Footnote A: Berthelot takes C_{24}H_{40}O_{20} as the formula of cellulose; and M. Vieille regards the highest nitrate as (C_{24}H_{18}(NO_{3}H)_{11}O_{9}). _Compt. Rend._, 1882, p. 132.] ~Properties of Gun-Cotton.~--The absolute density of gun-cotton is 1.5. When in lumps its apparent density is 0.1; if twisted into thread, 0.25; when subjected, in the form of pulp, to hydraulic pressure, 1.0 to 1.4. Gun-cotton preserves the appearance of the cotton from which it is made. It is, however, harsher to the touch; it is only slightly hygroscopic (dry gun-cotton absorbs 2 per cent. of moisture from the air). It possesses the property of becoming electrified by friction. It is soluble in acetic ether, amyl acetate, and acetone, insoluble in water, alcohol, ether, ether-alcohol, methyl-alcohol, &c. It is very explosive, and is ignited by contact with an ignited body, or by shock, or when it is raised to a temperature of 172° C. It burns with a yellowish flame, almost without smoke, and leaves little or no residue. The volume of the gases formed is large, and consists of carbonic acid, carbonic oxide, nitrogen, and water gas. Compressed gun-cotton when ignited often explodes when previously heated to 100° C. Gun-cotton kept at 80° to 100° C. decomposes slowly, and sunlight causes it to undergo a slow decomposition. It can, however, be preserved for years without undergoing any alteration. It is very susceptible to explosions by influence. For instance, a torpedo, even placed at a long distance, may explode a line of torpedoes charged with gun-cotton. The velocity of the propagation of the explosion in metallic tubes filled with pulverised gun-cotton has been found to be from 5,000 to 6,000 mms. per second in tin tubes, and 4,000 in leaden tubes (Sebert). Gun-cotton loosely exposed in the open air burns eight times as quickly as powder (Piobert). A thin disc of gun-cotton may be fired into from a rifle without explosion; but if the thickness of the disc be increased, an explosion may occur. The effect of gun-cotton in mines is very nearly the same as that of dynamite for equal weights. It requires, however, a stronger detonator, and it gives rise to a larger quantity of carbonic oxide gas. Gun-cotton should be neutral to litmus, and should stand the Government heat test--temperature of 150° F. for fifteen minutes (see page 249). In the French Navy gun-cotton is submitted to a heat test of 65° C. (= 149° F.) for eleven minutes. It should contain as small a percentage of soluble nitro-cotton and of non-nitrated cotton as possible. The products of perfectly detonated gun-cotton may be expressed by the following equation:-- 2C_{12}H_{14}O_{4}(NO_{3})_{6} = 18CO + 6CO_{2} + 14H_{2}O + 12N. It does not therefore contain sufficient oxygen for the complete combustion of its carbon. It is for this reason that when used for mining purposes a nitrate is generally added to supply this defect (as, for instance, in tonite). It tends also to prevent the evolution of the poisonous gas, carbonic oxide. The success of the various gelatine explosives is due to this fact, viz., that the nitro-glycerine has an excess of oxygen, and the nitro-cotton too little, and thus the two explosives help one another. In practice the gases resulting from the explosion of gun-cotton are-- Carbonic oxide, 28.55; carbonic acid, 19.11; marsh gas (CH_{4}), 11.17; nitric oxide, 8.83; nitrogen, 8.56; water vapour, 21.93 per cent. The late Mr E.O. Brown, of Woolwich Arsenal, discovered that perfectly wet and uninflammable compressed gun-cotton could be easily detonated by the detonation of a priming charge of the dry material in contact with it. This rendered the use of gun-cotton very much safer for use as a military or mining explosive. As a mining explosive, however, gun-cotton is now chiefly used under the form of tonite, which is a mixture of half gun-cotton and half barium nitrate. This material is sometimes spoken of as "nitrated gun-cotton." The weight of gun-cotton required to produce an equal effect either in heavy ordnance or in small arms is to the weight of gunpowder in the proportion of 1 to 3, i.e., an equal weight of gun-cotton would produce three times the effect of gunpowder. Its rapidity of combustion, however, requires to be modified for use in firearms. Hence the lower nitrates are generally used, or such compounds as nitro-lignose, nitrated wood, &c., are used. The initial pressure produced by the explosion of gun-cotton is very large, equal to 18,135 atmospheres, and 8,740 kilogrammes per square centimetre for 1 kilo., the heat liberated being 1,075 calories (water liquid), or 997.7 cals. (water gaseous), but the quantity of heat liberated changes with the equation of decomposition. According to Berthelot,[A] the heat of formation of collodion-cotton is 696 cals. for 1,053 grms., or 661 cals. for 1 kilo. The heat liberated in the total combustion of gun-cotton by free oxygen at constant pressure is 2,633 cals. for 1,143 grms., or for 1 kilo. gun-cotton 2,302 cals. (water liquid), or 2,177 cals. (water gaseous). The heat of decomposition of gun- cotton in a closed vessel, found by experiment at a low density of charge (0.023), amounts to 1,071 cals. for 1 kilo. of the substance, dry and free from ash. To obtain the maximum effect of gun-cotton it must be used in a compressed state, for the initial pressures are thereby increased. Wet gun-cotton s much less sensitive to shock than dry. Paraffin also reduces its liability to explode, so also does camphor. [Footnote A: "Explosives and their Power," trans. by Hake and M'Nab.] The substance known as celluloid, a variety of nitro-cellulose nearly corresponding to the formula C_{24}H_{24}(NO_{3}H)_{8}O_{12}, to which camphor and various inert substances are added, so as to render it non-sensitive to shock, may be worked with tools, and turned in the lathe in the same manner as ivory, instead of which material celluloid is now largely used for such articles as knife handles, combs, &c. Celluloid is very plastic when heated towards 150° C., and tends to become very sensitive to shock, and in large quantities might become explosive during a fire, owing to the general heating of the mass, and the consequent evaporation of the camphor. When kept in the air bath at 135° C., celluloid decomposes quickly. In an experiment (made by M. Berthelot) in a closed vessel at 135° C., and the density of the charge being 0.4, it ended in exploding, developing a pressure of 3,000 kilos. A large package of celluloid combs also exploded in the guard's van on one of the German railways a few years ago. Although it is not an explosive under ordinary circumstances, or even with a powerful detonator, considerable care should be exercised in its manufacture. ~The Manufacture of Gun-Cotton.~--The method used for the manufacture of gun-cotton is that of Abel (Spec. No. 1102, 20. 4. 65). It was worked out chiefly at Stowmarket[A] and Waltham Abbey,[B] but has in the course of time undergone several alterations. These modifications have taken place, however, chiefly upon the Continent, and relate more to the apparatus and machinery used than to any alteration in the process itself. The form of cellulose used is cotton-waste,[C] which consists of the clippings and waste material from cotton mills. After it has been cleaned and purified from grease, oil, and other fatty substances by treatment with alkaline solutions, it is carefully picked over, and every piece of coloured cotton rag or string carefully removed. The next operation to which it is submitted has for its object the opening up of the material. For this purpose it is put through a carding machine, and afterwards through a cutting machine, whereby it is reduced to a state suitable for its subsequent treatment with acids, that is, it has been cut into short lengths, and the fibres opened up and separated from one another. [Footnote A: The New Explosive Co. Works.] [Footnote B: Royal Gunpowder Factory.] [Footnote C: Costs from £10 to £25 a ton. In his description of the "Preparation of Cotton-waste for the Manufacture of Smokeless Powder," A. Hertzog states that the German military authorities require a cotton which when thrown into water sinks in two minutes; when nitrated, does not disintegrate; when treated with ether, yields only 0.9 per cent. of fat; and containing only traces of chlorine, lime, magnesia, iron, sulphuric acid, and phosphoric acid. If the cotton is very greasy, it must be first boiled with soda-lye under pressure, washed, bleached with chlorine, washed, treated with sulphuric acid or HCl, again washed, centrifugated, and dried; if very greasy indeed a preliminary treatment with lime-water is desirable. See also "Inspection of Cotton-Waste for Use in the Manufacture of Gun-cotton," by C.E. Munro, _Jour. Am. Chem. Soc._, 1895, 17, 783.] ~Drying the Cotton.~--This operation is performed in either of two ways. The cotton may either be placed upon shelves in a drying house, through which a current of hot air circulates, or dried in steam-jacketed cylinders. It is very essential that the cotton should be as dry as possible before dipping in the acids, especially if a wholly "insoluble" nitro-cellulose is to be obtained. After drying it should not contain more than 0.5 per cent. of moisture, and less than this if possible. The more general method of drying the cotton is in steam-jacketed tubes, i.e., double cylinders of iron, some 5 feet long and 1-1/2 foot wide. The cotton is placed in the central chamber (Fig. 10), while steam is made to circulate in the surrounding jacket, and keeps the whole cylinder at a high temperature (steam pipes may be coiled round the outside of an iron tube, and will answer equally well). By means of a pipe which communicates with a compressed air reservoir, a current of air enters at the bottom, and finds its way up through the cotton, and helps to remove the moisture that it contains. The raw cotton generally contains about 10 per cent. of moisture and should be dried until it contains only 1/2 per cent. or less. For this it will generally have to remain in the drying cylinder for about five hours. At the end of that time a sample should be taken from the _top_ of the cylinder, and dried in the water oven (100° C.[A]) for an hour to an hour and a half, and re-weighed, and the moisture then remaining in it calculated. [Footnote A: It is dried at 180° C. at Waltham Abbey, in a specially constructed drying chamber.] [Illustration: FIG. 10.--COTTON DRIER.] It is very convenient to have a large copper water oven, containing a lot of small separate compartments, large enough to hold about a handful of the cotton, and each compartment numbered, and corresponding to one of the drying cylinders. The whole apparatus should be fixed against the wall of the laboratory, and may be heated by bringing a small steam pipe from the boiler-house. It is useful to have a series of copper trays, about 3 inches by 6 inches, numbered to correspond to the divisions in the steam oven, and exactly fitting them. These trays can then be taken by a boy to the drying cylinders, and a handful of the cotton from each placed in them, and afterwards brought to the laboratory and weighed (a boy can do this very well), placed in their respective divisions of the oven, and left for one to one and a half hours, and re-weighed. When the cotton is found to be dry the bottom of the drying cylinder is removed, and the cotton pushed out from the top by means of a piece of flat wood fixed on a broom-handle. It is then packed away in galvanised- iron air-tight cases, and is ready for the next operation. At some works the cotton is dried upon shelves in a drying house through which hot air circulates, the shelves being of canvas or of brass wire netting. The hot air must pass under the shelves and through the cotton, or the process will be a very slow one. ~Dipping and Steeping.~--The dry cotton has now to be nitrated. This is done by dipping it into a mixture of nitric and sulphuric acids. The acids used must be strong, that is, the nitric acid must be at least of a gravity of 1.53 to 1.52, and should contain as little nitric oxide as possible. The sulphuric acid must have a specific gravity of 1.84 at 15° C., and contain about 97 per cent. of the mono-hydrate (H_{2}SO_{4}). In fact, the strongest acids obtainable should be used when the product required is gun-cotton, i.e., the highest nitrate. The sulphuric acid takes no part in the chemical reaction involved, but is necessary in order to combine with the water that is liberated in the reaction, and thus to maintain the strength of the nitric acid. The reaction which takes place is the following:-- 2(C_{6}H_{10}O_{5}) + 6HNO_{3} = C_{12}H_{14}(NO_{3})_{6} + 6 H_{2}O. 324 378 = 594 108. Cellulose. Gun-Cotton. Theoretically,[A] therefore, 1 part of cellulose should form 1.8 part of gun-cotton. Practically, however, this is never obtained, and 1.6 lb. from 1 lb. of cellulose is very good working. The mixture of acids used is generally 1 to 3, or 25 per cent. nitric acid to 75 per cent. sulphuric acid. [Footnote A: (594 x 1)/324= 1.83.] [Illustration: FIG. 11.--TANK FOR DIPPING COTTON.] [Illustration: FIG. 12.--THE COOLING PITS.] The dipping is done in cast-iron tanks (Fig. 11), a series of which is arranged in a row, and cooled by a stream of cold water flowing round them. The tanks hold about 12 gallons, and the cotton is dipped in portions of 1 lb. at a time. It is thrown into the acids, and the workman moves it about for about three minutes with an iron rabble. At the end of that time he lifts it up on to an iron grating, just above the acids, fixed at the back of the tank, where by means of a movable lever he gently squeezes it, until it contains about ten times its weight of acids (the 1 lb. weighs 10 lbs.). It is then transferred to earthenware pots to steep. [Illustration: FIG. 13.--COTTON STEEPING POT.] ~Steeping.~--The nitrated cotton, when withdrawn from the dipping tanks, and still containing an excess of acids, is put into earthenware pots of the shape shown in Figs. 12 and 13. The lid is put on, and the pots placed in rows in large cooling pits, about a foot deep, through which a stream of water is constantly flowing. These pits form the floor of the steeping house. The cotton remains in these pots for a period of forty-eight hours, and must be kept cool. Between 18° and 19° C. is the highest temperature desirable, but the cooler the pots are kept the better. At the end of forty-eight hours the chemical reaction is complete, and the cotton is or should be wholly converted into nitro-cellulose; that is, there should be no unnitrated cotton. [Illustration: FIG. 14.--HYDRO-EXTRACTOR.] ~Whirling Out the Acid.~--The next operation is to remove the excess of acid. This is done by placing the contents of two or three or more pots into a centrifugal hydro-extractor (Fig. 14), making 1,000 to 1,500 revolutions per minute. The hydro-extractor consists of a machine with both an inner cylinder and an outer one, both revolving in concert and driving outwardly the liquid to the chamber, from which it runs away by a discharge pipe. The wet cotton is placed around the inner cone. The cotton, when dry, is removed, and at once thrown into a large tank of water, and the waste acids are collected in a tank.[A] [Footnote A: Care must be taken in hot weather that the gun-cotton does not fire, as it does sometimes, directly the workman goes to remove it after the machine is stopped. It occurs more often in damp weather. Dr Schüpphaus, of Brooklyn, U.S.A., proposes to treat the waste acids from the nitration of cellulose by adding to them sulphuric anhydride and nitric acid. The sulphuric anhydride added converts the water liberated from the cellulose into sulphuric acid.] ~Washing.~--The cotton has now to be carefully washed. This is done in a large wooden tank filled with water. If, however, a river or canal runs through the works, a series of wooden tanks, the sides and bottoms of which are pierced with holes, so as to allow of the free circulation of water, should be sunk into a wooden platform that overhangs the surface of the river in such a way that the tanks are immersed in the water, and of course always full. During the time that the cotton is in the water a workman turns it over constantly with a wooden paddle. A stream of water, in the form of a cascade, should be allowed to fall into these tanks. The cotton may then be thrown on to this stream of water, which, falling some height, at once carries the cotton beneath the surface of the water. This proceeding is necessary because the cotton still retains a large excess of strong acids, and when mixed with water gives rise to considerable heat, especially if mixed slowly with water. After the cotton has been well washed, it is again wrung out in a centrifugal machine, and afterwards allowed to steep in water for some time. [Illustration: FIG. 15_a_.--THE BEATER FOR GUN-COTTON.] ~Boiling.~--The washed cotton is put into large iron boilers with plenty of water, and boiled for some time at 100° C. In some works lead-lined tanks are used, into which a steam pipe is led. The soluble impurities of unstable character, to which Sir F.A. Abel traced the liability of gun- cotton to instability, are thereby removed. These impurities consist of the products formed by the action of nitric acid on the fatty and resinous substances contained in the cotton fibres. The water in the tanks should be every now and again renewed, and after the first few boilings the water should be tested with litmus paper until they are no longer found to be acid. [Illustration: FIG. 15_b_.--WHEEL OF BEATER.] ~Pulping.~--The idea of pulping is also due to Abel. By its means a very much more uniform material is obtained. The process is carried out in an apparatus known as a "Beater" or "Hollander" (Fig. 15, _a, b_). It consists of a kind of wooden tank some 2 or 3 feet deep of an oblong shape, in which a wheel carrying a series of knives is made to revolve, the floor of the tank being sloped up so as to almost touch the revolving wheels. This part of the floor, known as the "craw," is a solid piece of oak, and a box of knives is fixed into it, against which the knives in the revolving wheel are pressed. The beater is divided into two parts--the working side, in which the cotton is cut and torn between the knife edges in the revolving cylinder and those in the box; and the running side, into which the cotton passes after passing under the cylinder. The wheel is generally boxed in to prevent the cotton from being thrown out during its revolution. The cotton is thus in constant motion, continually travelling round, and passing between the knives in the revolving cylinder and those in the box fixed in the wooden block beneath it. The beater is kept full of water, and the cotton is gradually reduced to a condition of pulp. The wheel revolves at the rate of 100 to 150 times a minute. [Illustration: FIG. 16_a_.--POACHER FOR WASHING GUN-COTTON.] [Illustration: FIG. 16_b_.--PLAN OF THE POACHER.] [Illustration: FIG. 16_c_.--ANOTHER FORM OF POACHER.] When the gun-cotton is judged to be sufficiently fine, the contents of the beater are run into another very similar piece of machinery, known as the "poacher" (Fig. 16, _a, b, c_), in which the gun-cotton is continuously agitated together with a large quantity of water, which can be easily run off and replaced as often as required. When the material is first run into the poacher from the beater, the water with which it is then mixed is first run away and clean water added. The paddle wheel is then set in motion, and at intervals fresh water is added. There is a strainer at the bottom of the poacher which enables the water to be drawn off without disturbing the cotton pulp. After the gun-cotton has been in the poacher for some time, a sample should be taken by holding a rather large mesh sieve in the current for a minute or so. The pulp will thus partly pass through and partly be caught upon the sieve, and an average sample will be thus obtained. The sample is squeezed out by hand, bottled, and taken to the laboratory to be tested by the heat test for purity. It first, however, requires to be dried. This is best done by placing the sample between coarse filter paper, and then putting it under a hand-screw press, where it can be subjected to a tolerably severe pressure for about three minutes. It is then rubbed up very finely with the hands, and placed upon a paper tray, about 6 inches by 4-1/2 inches, which is then placed inside a water oven upon a shelf of coarse wire gauze, the temperature of the oven being kept as near as possible to 120° F. (49° C.), the gauze shelves in the oven being kept about 3 inches apart. The sample is allowed to remain at rest for fifteen minutes in the oven, the door of which is left wide open. After the lapse of fifteen minutes the tray is removed and exposed to the air of the laboratory (away from acid fumes) for two hours, the sample being at some point within that time rubbed upon the tray with the hand, in order to reduce it to a fine and uniform state of division. Twenty grains (1.296 grm.) are used for the test. (See Heat Test, page 249.) If the gun-cotton sample removed from the poacher stands the heat test satisfactorily, the machine is stopped, and the water drained off. The cotton is allowed some little time to drain, and is then dug out by means of wooden spades, and is then ready for pressing. The poachers hold about 2,000 lbs. of material, and as this represents the products of many hundred distinct nitrating operations, a very uniform mixture is obtained. Two per cent. of carbonate of soda is sometimes added, but it is not really necessary if the cotton has been properly washed. ~Compressing Gun-Cotton.~--The gun-cotton, in the state in which it is removed from the poacher, contains from 28 to 30 per cent. of water. In order to remove this, the cotton has to be compressed by hydraulic power. The dry compressed gun-cotton is packed in boxes containing 2,500 lbs. of dry material. In order to ascertain how much of the wet cotton must be put into the press, it is necessary to determine the percentage of water. This may be done by drying 2,000 grains upon a paper tray (previously dried at 100° C.) in the water oven at 100° C. for three hours, and re-weighing and calculating the percentage of water. It is then easy to calculate how much of the wet gun-cotton must be placed in the hopper of the press in order to obtain a block of compressed cotton of the required weight. Various forms of presses are used, and gun-cotton is sent out either as solid blocks, compressed discs, or in the form of an almost dry powder, in zinc- lined, air-tight cases. The discs are often soaked in water after compression until they have absorbed 25 per cent. of moisture. [Illustration: FIG. 17.--OLD METHOD. 100 PIECES.] [Illustration: FIG. 18.--NEW METHOD. ONE SOLID BLOCK.] At the New Explosives Company's Stowmarket Works large solid blocks of gun-cotton are pressed up under a new process, whereby blocks of gun- cotton, for use in submarine mines or in torpedo warheads, are produced. Large charges of compressed gun-cotton have hitherto been built up from a number of suitably shaped charges of small dimensions (Fig. 17), as it has been impossible to compress large charges in a proper manner. The formation of large-sized blocks of gun-cotton was the invention of Mr A. Hollings. Prior to the introduction of this method, 8 or 9 lbs. had been the limit of weight for a block. This process has been perfected at the Stowmarket factory, where blocks varying from the armour-piercing shell charge of a few ounces up to blocks of compressed gun-cotton mechanically true, weighing 4 to 5 cwts. for torpedoes or submarine mines, are now produced. At the same time the new process ensures a uniform density throughout the block, and permits of any required density, from 1.4 downwards, being attained; it is also possible exactly to regulate the percentage of moisture, and to ensure its uniform distribution. The maximum percentage of moisture depends, of course, upon the density. By the methods of compression gun-cotton blocks hitherto employed, blocks of a greater thickness than 2 inches, or of a greater weight than 9 lbs., could not be made, but with the new process blocks of any shape, size, thickness, or weight that is likely to be required can be made readily and safely. The advantages which are claimed for the process may be enumerated as follows:--(1.) There is no space wasted, as in the case with built-up charges, through slightly imperfect contact between the individual blocks, and thus either a heavier charge--i.e., about 15 per cent. more gun- cotton--can be got into the same space, or less space will be occupied by a charge of a given weight. (2.) The metallic cases for solid charges may be much lighter than for those built-up, since with the former their function is merely to prevent the loss of moisture from wet gun-cotton, or to prevent the absorption of moisture by dry gun-cotton. They can thus be made lighter, as the solid charge inside will prevent deformation during transport. With built-up charges the case must be strong enough to prevent damage, either to itself or to the charge it contains. For many uses a metal case, however light, may be discarded, and one of a thin waterproof material substituted. (3.) The uniform density of charges made by this process is very favourable to the complete and effective detonation of the entire mass, and to the presence of the uniform amount of moisture in every part of the charge. (4.) Any required density, from the maximum downwards, may be obtained with ease, and any required amount of moisture left in the charge. These points are of great importance in cases where, like torpedo charges, it is essential to have the centre of gravity of the charge in a predetermined position both vertically and longitudinally, and the charge so fixed in its containing case that the centre of gravity cannot shift. The difficulty of ensuring this with a large torpedo charge built up from a number of discs and segments is well known. Even with plain cylindrical or prismatic charges a marked saving in the process of production is effected by this new system. The charges being in one block they are more easily handled for the usual periodical examination, and they do not break or chafe at the edges, as in the case of discs and cubes in built-up charges. A general view of the press is given in Fig. 19. The gun-cotton in a container is placed on a cradle fixed at an angle to the press. The mould is swivelled round, and the charge pushed into it with a rammer, and it is then swivelled back into position. The mould is made up of a number of wedge pieces which close circumferentially on the enclosed mass, which is also subjected to end pressure. Holes are provided for the escape of water. [Illustration: FIG. 19.--A 4-CWT. BLOCK OF GUN-COTTON BEING TAKEN FROM HYDRAULIC PRESS.] ~The Waltham Abbey Process.~--At the Royal Gunpowder Factory, Waltham Abbey, the manufacture of gun-cotton has been carried out for many years. The process used differs but little from that used at Stowmarket. The cotton used is of a good quality, it is sorted and picked over to remove foreign matters, &c., and is then cut up by a kind of guillotine into 2-inch lengths. It is then dried in the following manner. The cotton is placed upon an endless band, which conducts it to the stove, or drying closet, a chamber heated by means of hot air and steam traps to about 180° F.; it falls upon a second endless band, placed below the first; it travels back again the whole length of the stove, and so on until delivered into a receptacle at the bottom of the farther end, where it is kept dry until required for use. The speed at which the cotton travels is 6 feet per minute, and as the length of the band travelled amounts to 126 feet, the operation of drying takes twenty-one minutes. One and a quarter lb. are weighed out and placed in a tin box; a truck, fitted to receive a number of these boxes, carries it along a tramway to a cool room, where it is allowed to cool. ~Dipping.~--Mixed acids are used in the proportion of 1 to 3, specific gravity nitric acid 1.52, and sulphuric acid 1.84. The dipping tank is made of cast iron, and holds 220 lbs. of mixed acids, and is surrounded on three sides by a water space in order to keep it cool. The mixed acids are stored in iron tanks behind the dipping tanks, and are allowed to cool before use. During the nitration, the temperature of the mixed acids is kept at 70° F., and the cotton is dipped in quantities of 1-1/2 lb. at a time. It is put into a tin shoot at the back of the dipping tank, and raked into the acids by means of a rabble. It remains in the acids for five or six minutes, and is then removed to a grating at the back, pressed and removed. After each charge of cotton is removed from the tank, about 14 lbs. of fresh mixed acids are added, to replace amount removed by charge. The charge now weighs, with the acids retained by it, 15 lbs.; it is now placed in the pots, and left to steep for at least twenty-four hours, the temperature being kept as low as possible, to prevent the formation of soluble cotton, and also prevent firing. The proportion of soluble formed is likely to be higher in hot weather than cold. The pots must be covered to prevent the absorption of moisture from the air, or the accidental entrance of water, which would cause decomposition, and consequent fuming off, through the heat generated by the action of the water upon the strong acids. The excess of acids is now extracted by means of hydro-extractors, as at Stowmarket. They are worked at 1,200 revolutions per minute, and whirled for five minutes (10-1/2 lbs. of waste acids are removed from each charge dipped). The charge is then washed in a very similar manner to that previously described, and again wrung out in a centrifugal extractor (1,200 revolutions per minute). The gun-cotton is now boiled by means of steam in wooden tanks for eight hours; it is then again wrung out in the extractors for three minutes, boiled for eight hours more, and again wrung out; it is then sent to the beater and afterwards to the poacher. The poachers hold 1,500 gals. each, or 18 cwt. of cotton. The cotton remains six hours in the poachers. Before moulding, 500 gals. of water are run into the poacher, and 500 gals. of lime water containing 9 lbs. of whiting and 9 gals. of a caustic soda solution. This mixture is of such a strength that it is calculated to leave in the finished gun-cotton from 1 to 2 per cent. of alkaline matter. By means of vacuum pressure, the pulp is now drawn off and up into the stuff chest--a large cylindrical iron tank, sufficiently elevated on iron standards to allow room for the small gauge tanks and moulding apparatus below. It holds the contents of one poacher (18 cwt.), and is provided with revolving arms to keep the pulp stirred up, so that it may be uniformly suspended in water. Recently a new process, invented by J.M. and W.T. Thomson (Eng. Pat. No. 8,278, 1903), has been introduced at the Waltham Abbey Factory. The object of this invention is the removal of the acids of nitration from the nitrated material after the action has been completed, and without the aid of moving machinery, such as presses, rollers, centrifugals, and the like. The invention consists in the manufacture of nitrated celluloses by removing the acids from the nitrated cellulose directly by displacement without the employment of either pressure or vacuum or mechanical appliances of any kind, and at the same time securing the minimum dilution of the acids. It was found that if water was carefully run on to the surface of the acids in which the nitro-cellulose is immersed, and the acids be slowly drawn off at the bottom of the vessel, the water displaces the acid from the interstices of the nitro-cellulose without any undesirable rise in temperature, and with very little dilution of the acids. By this process almost the whole of the acid is recovered in a condition suitable for concentration, and the amount of water required for preliminary washing is very greatly reduced. The apparatus which is used for the purpose consists of a cylindrical or rectangular vessel constructed with a perforated false bottom and a cock at its lowest point for running off the liquid. Means are also provided to enable the displacing water to be run quietly on to the surface of the nitrating acids.[A] [Footnote A: In a further patent (Eng. Pat. 7,269, 1903, F.L. Natham), J.M. Thomson and W.T. Thomson propose by use of alcohol to replace the water, used in washing nitro-cellulose, and afterward to remove the alcohol by pressing and centrifuging.] The apparatus is shown in Fig. 2O, side elevation, and in Fig. 21 a plan of the nitrating vessel and its accessories is given. In Fig. 20 is shown in sectional elevation one of the trough devices for enabling liquids to be added to those in the nitrating vessel without substantial disturbance. [Illustration: FIG. 20.--SECTIONAL ELEVATION OF THOMSON'S APPARATUS, _a_, Tank; _b_, False Bottom; _c_, Bottom; _c'_, Ribs; _d_, Draining Outlet; _e_, Grid; _f_, Troughs, with Aprons _g_; _h_, Pipe, with Branches _h'_, leading to Troughs, _f_; _k'_, Outlet Pipe of the Sulphuric Acid Tank _k_; _l_, Water Supply Pipe; _m_, Pipe to supply of Nitrating Acids; _o_, Perforations of Trough _f_; _p_, Cock to remove Acid.] In carrying out this invention a rectangular lead-lined or earthenware tank _a_ is employed, having a false bottom _b_, supported by ribs _c'_, over the real bottom _c_, which slopes down to a draining outlet pipe _d_, provided with a perforated grid or plate _e_, adapted to prevent choking of the outlet. Suitably supported near the top of the vessel _a_ are provided two troughs, _f_ having depending aprons _g_, a pipe _h_ has two branches _h'_, leading to the troughs, _f_. This pipe _h_ is adapted to be connected by a rubber pipe either to the outlet pipe _k'_ of the sulphuric acid tank _k_ or the water supply pipe _l_. The nitrating acids are supplied through the pipe _m_. A charge of mixed nitrating acids is introduced into the vessel _a_ say up to the level _n_, and the dry cellulose thrown into the acids in small quantities at a time, being pushed under the surface in the usual way. [Illustration: FIG. 21.--PLAN OF THOMSON'S APPARATUS, _a_, Tank; _b_, False Bottom; _c'_, Ribs; _e_, Grid; _f_, Troughs; _g_, Aprons; _h_ and _h'_, Pipes to Troughs _f_; _k_, Sulphuric Acid Tank; _m_, Pipe to Nitrating Acids Tank; _o_, Perforations of Troughs; _p_, Cock to remove Acid.] A thin layer, say half an inch, of a suitable liquid, preferably sulphuric acid, of a gravity not exceeding that of the waste acid to be produced, is run carefully on the top of the acids by means of the troughs _f_, which are perforated as shown at _o_, so that the sulphuric acid runs down the aprons _g_, and floats on the nitrating acids. The whole is then allowed to stand till nitration has been completed. Water is then supplied to the troughs by way of the pipes _l_, _h_, and _h'_, and is allowed to float very gently over the surface of the sulphuric acid, and when a sufficient layer has been formed, the cock _p_ at the bottom of the apparatus is opened, and the acid slowly drawn off, water being supplied to maintain the level constant. It is found that the rate of displacement of the acids is a factor which exerts a considerable influence on the properties of the resulting nitro-cellulose, and affords a means of regulating the temperature of displacement. A rate of displacement which has been found suitable is about two inches in depth of the vessel per hour when treating highly nitrated celluloses, but this rate may, in some cases, be considerably increased. The flow of water at the top of the apparatus is regulated so that a constant level is maintained. By this means the water gradually and entirely displaces the acids from the interstices of the nitro-cellulose, the line of separation between the acids and the water being fairly sharply defined throughout. The flow of water is continued until that issuing at the bottom is found to be free from all trace of acid. The purification of the nitro-cellulose is then proceeded with as usual, either in the same vessel or another. In the process above described, the object of the introduction of a small layer of sulphuric acid is mainly to prevent the fuming which would otherwise take place, and is not essential, as it is found it can be omitted without any deleterious effect. In order to use the mixed acids in the most economical manner, the waste acid from a previous operation may be used for a first nitration of the cellulose; being afterwards displaced with fresh acids which carry the nitration to the required degree before they are in turn displaced by water. The apparatus may be used merely for the removal of the acid, in which case the nitration is carried out in other vessels in the usual way, and the nitro-cellulose removed to the displacement apparatus where it is just covered with waste acid, and the displacement then proceeded with as above described. In some cases the process is carried out in an ordinary nitrating centrifugal, using the latter to effect preliminary drying after acid extraction. This gives a great advantage over the usual method of working ordinary centrifugal nitrating apparatus, because the acid being removed before the centrifugal is run, practically all danger of firing therein disappears, and a greater proportion of the waste acid is recovered. In some cases the acids and water may be supplied by perforated pipes, lying along the edges of the nitrating vessel, and these edges may, if desired, be themselves made inclined, like the sides of the troughs _f_. In the case of effecting nitration in centrifugals as above, the displacing sulphuric acid and water may thus be supplied round the edges of the machines, or removal troughs such as _f_ may be used. It will be obvious that any inert liquid of suitable specific gravity may be used instead of sulphuric acid, as a separation layer. ~Moulding.~--By means of the small measuring tank above referred to, the gun-cotton pulp is drawn off from the stuff chest, and run into moulds of the shapes and sizes required. Thence a large proportion of the water is drawn off by means of tubes connected with the vacuum engine, the moulds having bottoms of fine wire gauze, in order to prevent the pulp from passing through. Hydraulic pressure of about 34 lbs. on the square inch is then applied, which has the effect of compressing the pulp into a state in which it has sufficient consistency to enable it to be handled with care, and also expels a portion of the remaining water. ~Compressing.~--The moulded gun-cotton is now taken to the press house, which is situated at some distance from the rest of the factory. Here the moulds are subjected to powerful hydraulic pressure, from 5 to 6 tons per square inch, and is compressed to one-third of its previous bulk. The slabs or discs thus formed are kept under pressure for a short time, not exceeding a minute and a half, to give the requisite density. It should, when removed, be compact, and just sink in water, and should perceptibly yield to the pressure of the fingers. There are perforations in the press blocks, to allow of the escape of gases, if formed, by reason of sufficient heat being generated. The men working the press are placed under cover, behind strong rope mantlets having eye tubes which command a view of the press. ~Packing.~--The finished slabs and discs are dipped into a solution of soda and carbolic acid, and packed in special wood metal-lined cases. When it is to be sent abroad, the metal lining, which is made of tinned copper, is soldered down, but both the outer wooden and inner metal cases are fitted with air-tight screw-plugs, so that when necessary water can be added without unfastening the cases. ~Reworked gun-cotton~ does not make such good discs as new pulped gun- cotton, probably because the fibrous tenacity of the gun-cotton has been destroyed by the amount of pressure it has previously undergone, so that when repulped it resembles fine dust, and a long time is required to press it into any prescribed form. It is generally boiled for eight hours to open up the fibre and remove alkali, then broken up by hand with wooden mallets, pulped, and then used with fresh gun-cotton in the proportion of 1 to 5 parts. ~Manufacture at Le Bouchet.~--At Le Bouchet gun-cotton was made thus:--200 grms. of cotton were steeped for an hour in 2 litres of a mixture of 1 volume concentrated nitric and 2 volumes sulphuric acid. The cotton was then removed and pressed, whereby 7/10ths of the waste acids was recovered. After this it was washed for one to one and a half hours in running water, strongly pressed again; allowed to lie for twenty-four hours in wood-ash lye; then well washed in running water; pressed, and finally dried on a wide linen sheet, through which was forced air heated to 60° C. The average yield from 100 parts of cotton was 165 parts of gun- cotton. The strong pressings of the gun-cotton, while still impregnated with acids, caused subsequent washings to be difficult and laborious. ~Granulation of Gun-Cotton.~--Gun-cotton is often required in the granulated form for use either alone or with some form of smokeless powder. This is done under the patent of Sir Frederick Abel in the following manner:--The gun-cotton from the poacher is placed in a centrifugal machine, very similar to the hydro-extractors before mentioned, and used for wringing out the acids. In this machine it loses water until it only contains 33 per cent., and is at the same time reduced to a more or less fibrous state. It is then taken to the granulating room, where it is first passed through sieves or perforations, which break up the mass into little pieces like shot. The material is then transferred to a revolving drum made of wood or stout leather, which is kept constantly revolving for some time. The material is occasionally sprinkled with water. The drum in turning, of course, carries the granules partially round with it, but the action of gravity causes them to descend constantly to the lowest point, and thus to roll over one another continually. The speed of the drum must not be too rapid. None of the granules must be carried round by centrifugal force, but it must be fast enough to carry them some little distance up the side of the drum. After removal from the drum the granules are dried upon shelves in the drying house. Gun-cotton is also dissolved in acetone or acetic ether until it has taken the form of a jelly. It is then rolled into thin sheets, and when dry cut up into little squares. In the manufacture of smokeless powders from nitro-cellulose, nitro-lignine, &c., the various substances are mixed with the gun-cotton or collodion-cotton before granulating. ~Collodion-Cotton.~--In the manufacture of collodion or soluble cotton the finer qualities of cotton-waste are used and the acids used in the dipping tanks are much weaker. The manufacture of collodion-cotton has become of more importance than gun-cotton, by reason of its use for the manufacture of the various forms of gelatine, such as gelatine dynamite, gelignite, forcite, &c., and also on account of its extensive use in the manufacture of many of the smokeless powders. It is also used for the manufacture of "collodion," which is a solution of collodion-cotton in ether-alcohol; for the preparation of celluloid, and many other purposes. It is less explosive than gun-cotton, and consists of the lower nitrates of cellulose. It is soluble in nitro-glycerine, and in a mixture of 2 parts of ether and 1 of alcohol; also in acetone, acetic ether, and other solvents. MM. Ménard and Domonte were the first to prepare a soluble gun- cotton, and its investigation was carried on by Béchamp, who showed that its properties and composition were different to those of gun-cotton. ~Manufacture.~--The cotton used is cotton-waste.[A] It is thought by some that Egyptian cotton is preferable, and especially long fibre varieties. The strength of the acids used is, however, of more importance than the quality of the cotton. The percentage composition of the acid mixture which gives the best results is as follows:--Nitric acid, 23 per cent.; sulphuric acid, 66 per cent.; and water, 11 per cent; and has a specific gravity of 1.712 (about). It can be made by mixing sulphuric acid of specific gravity 1.84 with nitric acid of specific gravity 1.368 in the proportions of 66 per cent. and 34 per cent. respectively. (The production of the penta-nitro-cellulose is aimed at if the collodion-cotton is for use as an explosive.) If the acids are much weaker than this, or potassium nitrate and sulphuric acid is used, the lower nitrates will be formed. The product, while being entirely soluble in ether-alcohol or nitro-glycerine, will have a low nitrogen content, whereas a material with as high a nitrogen as 12 or 12.6 is to be aimed at. [Footnote A: Raw cotton is often used.] The cotton should not be allowed to remain in the dipping tanks for more than five minutes, and the acid mixture should be kept at a temperature of 28° C. or thereabouts; and the cotton should be removed after a few minutes, and should not be pressed out, as in the case of gun-cotton, but at once transferred to the pots and allowed to steep for forty-eight hours. (Some prefer twenty-four hours, but there is more chance in this case of the product containing non-nitrated cellulose.) When the nitration is complete, the collodion-cotton is removed from the pots, and treated in exactly the same manner as described under gun-cotton. The produce should be entirely soluble in ether-alcohol and nitro-glycerine, and contain as near 12.7 per cent. of nitrogen as possible. The theoretical nitrogen is for the penta-nitro-cellulose 12.75 per cent. This will, however, seldom if ever be obtained. The following are some of the results I have obtained from different samples:-- Nitrogen. (1.) (2.) (3.) German make 11.64 11.48 11.49 per cent. Stowmarket 12.57 12.60 11.22 " Walsrode 11.61 12.07 11.99 " Faversham 12.14 11.70 11.60 " and the following was the analysis of a sample (No. 1) of German-made collodion-cotton, which made very good blasting gelatine:-- _ Soluble cotton (collodion) 99.118 per cent.| Nitrogen = 11.64 per cent. Gun-cotton 0.642 " _| Non-nitrated cotton 0.240 " Total ash 0.25 " It should contain as little non-nitrated or unconverted cotton and as little gun-cotton as possible, as they are both insoluble in nitro- glycerol. The quality and composition of any sample of collodion-cotton can be quickly inferred by determining the percentage of nitrogen by means of the nitrometer and the use of the solubility test.[A] A high nitrogen content coupled with a high solubility is the end to be aimed at; a high nitrogen with a low solubility shows the presence of gun-cotton, and a low nitrogen, together with a low solubility, the presence of unnitrated cotton. Where complete solubility is essential and the percentage of nitrogen less important, Dr Lunge recommends nitration with a mixture of equal parts of sulphuric and nitric acids containing from 19 to 20 per cent. of water. [Footnote A: See Analysis of Explosives.] Mr T.R. France claims to have invented some improvements in the manufacture of soluble nitro-cellulose. His object has been to produce an article as uniform as possible. His explanation of the imperfect action of the acids is that, however uniform the mixed acids may be in strength and proportions, and however carefully the operations of nitrating, &c., may be conducted, there are variable elements found in different samples of cotton. The cotton fibre has for its protection a glazed surface. It is tubular and cellular in structure, and contains a natural semi-fluid substance composed of oil or gum, which varies in nature according to the nature of the soil upon which the cotton is grown. The tubes of the fibre seem to be open at one end only when the fibre is of normal length. When, therefore, the cotton is subjected to the action of the mixed acids, the line of least resistance seems to be taken by them, viz., the insides of the tubes constituting the fibre of the cotton, into which they are taken by capillary attraction, and are subject to change as they progress, and to the increased resistance from the oil or gum, &c., in their progress, and therefore to modified action, the result of which is slower and slower action, or chemical change. He also thinks it is possible that the power of capillary attraction is balanced in the tubes by air contained therein, after a little, sufficiently so to prevent the acids from taking full effect. To get over this, Mr France uses his cotton in a fine state, almost dust, in fact, and then nitrates in the usual mixture of acids at 40° to 90° F., the excess of acids being removed by pressure. He says he does not find it necessary to wash this fine cotton dust in an alkaline solution previous to nitration. His mixed acids consist of 8 parts HNO_{3} = 42° B., and 12 parts H_{2}SO_{4} = 66° B., and he stirs in the dipping tank for fifteen minutes, the temperature being 50° F. to 100° F., the temperature preferred being 75° F. ~"Nitrated" Gun-Cotton.~--The nitrates that are or have been mixed with gun-cotton in order to supply oxygen are potassium nitrate, ammonium nitrate, and barium nitrate (tonite). The total combustion of gun-cotton by potassium nitrate corresponds to the equation:-- 10[C_{24}H_{18}(NO_{3}H)_{11}O_{9}] + 82KNO_{3} = 199CO_{2} + 41K_{2}CO_{3} + 145H_{2}O + 96N_{2}, or 828 grms. of nitrate for 1,143 grms. of gun-cotton, or 42 per cent. nitrate and 58 per cent. gun-cotton. The explosive made at Faversham by the Cotton Powder Company, and known as tonite No. 1, consists of very nearly half gun-cotton and half barium nitrate. The relations by weight of total combustion would be 51.6 of gun-cotton to 48.4 of barium nitrate. The average composition of tonite I have found by analysis to be 51 per cent. gun-cotton to 49 per cent. barium nitrate. The heat liberated is practically the same as for an equivalent weight of KNO_{3}; but the barium nitrate mixture weighs 2,223 grms. instead of 1,971 grms., or one-eighth more. The advantage in mixing a nitrate with gun-cotton is that it supplies oxygen, and by converting all the carbon into carbonic acid, prevents the formation of the poisonous gas carbonic oxide (CO). The nitrates of potassium and barium are also used admixed with nitro- cellulose in several of the sporting smokeless powders. ~The Manufacture of Tonite.~--The explosive tonite was patented by Messrs Trench, Faure, and Mackie, and is manufactured at Faversham and Melling at the works of the Cotton Powder Company, and at San Francisco by the Tonite Powder Company. It consists of finely divided and macerated gun-cotton incorporated with finely ground nitrate of barium which has been carefully recrystallised. It is made by acting upon carbonate of barium[A] with nitric acid. The wet and perfectly purified, finely pulped gun-cotton is intimately mixed up between edge runners with about the same weight of nitrate, and the mixing and grinding continued until the whole has become an intimately mixed paste. This paste is then compressed into cartridges, formed with a recess at one end for the purpose of inserting the detonator. The whole is then covered with paraffined paper. [Footnote A: Witherite, BaCO_{3} + 2HNO_{3} = Ba(NO_{3})_{2} + CO_{2} + H_{2}O.] The tonite No. 2 consisted of gun-cotton, nitrates of potash and soda, charcoal and sulphur. Tonite No. 3[A] is composed as follows:--Gun-cotton, 19 per cent.; di-nitro-benzol, 13 per cent.; and barium nitrate, 68 per cent. or similar proportions. It is a yellowish colour, and being slower in its explosive action, is better adapted for blasting soft rock. [Footnote A: Tonite No. 1 was patented by Messrs Trench, Faure, and Mackie, and tonite Nos. 2 and 3 by Trench alone.] Tonite is extensively used in torpedoes and for submarine blasting, also for quarries, &c. Large quantities were used in the construction of the Manchester Ship Canal. Among its advantages are, that the English railways will take tonite on the same footing as gunpowder; it is a very dense material; if wetted it can easily be dried in the sun; it very readily explodes by the use of a proper detonator; while it burns very slowly and without the least danger; the cartridges being waterproofed, it can be employed in wet bore holes, and it can be tamped with water; and finally, as it contains sufficient oxygen to oxidise the carbon, no carbonic oxide (CO) gas is formed, i.e., its detonation is perfect. It is a very safe explosive to use, being little susceptible to either blows or friction. Not long ago, a committee, composed of Prof. P. Bedson, Drs Drummond and Hume, Mr T. Bell, one of H.M. Inspectors of Coal Mines, and others, in considering the problem whether the fumes produced by the combustion of tonite were injurious to health, carried out a series of experiments in coal mines for this purpose. The air at the "intake" was analysed, also the air of the "return," and the smoky air in the vicinity of the shot holes. The cartridge was surrounded by the flame-extinguishing mixture, and packed in a brown paper bag. During the first experiment nineteen shots were fired (= 6.29 lbs. tonite). The "return" air showed only a trace of carbonic oxide gas (CO). At the second experiment thirteen shots were fired (= 4.40 lbs. tonite), and analysis of the air of the "return" showed that CO was present in traces only, whilst the fumes contained only 1.9 to 4.8 parts per 10,000. ~Dangers in connection with the Manufacture of Guncotton, &c.~--Of all the nitro compounds, the least dangerous to manufacture are gun-cotton and collodion-cotton. The fact that the Stowmarket Factory is within five minutes' walk of the town shows how safe the manufacture of this explosive is regarded. With the exception of the nitration and the compression into blocks or discs, the whole process is worked with a large excess of water, and the probability of an explosion is thus reduced to a minimum. Among the precautions that should, however, be taken, are--first, the careful extraction of the resinous and soluble substances from the cotton before nitration, as it was shown many years ago by Sir F.A. Abel that the instability of the gun-cotton first manufactured in England and Austria was chiefly due to these compounds. They are generally removed by boiling the cotton in a soda solution. The actual nitration of cotton is not a dangerous operation, but the operations of wringing in the hydro-extractors, and washing the nitro- cotton after it leaves the first centrifugal machine, are somewhat so. Great care should be taken that the wrung-out nitro-cotton at once comes in contact with a large excess of water, i.e., is at once immersed entirely in the water, since at this stage it is especially liable to decomposition, which, once started, is very difficult to stop. The warmer the mixture and the less water it contains, the more liable it is to decomposition; hence it is that on warm and damp days the centrifugal machines are most likely to fire. The commencement of decomposition may be at once detected by the evolution of red fumes. Directly the gun-cotton is immersed in the large quantity of water in the beater and poacher it is safe. In order that the final product may be stable and have good keeping qualities, it is necessary that it should be washed completely free from acid. The treatment in the beater and poacher, by causing the material to assume the state of a fine pulp, in contact with a large quantity of water, does a good deal to get rid of the free acid, but the boiling process is absolutely necessary. It has been proposed to neutralise the free acid with a dilute solution of ammonia; and Dr C.O. Weber has published some experiments bearing upon this treatment. He found that after treatment with ammonia, pyroxyline assumed a slightly yellowish tinge, which was a sure sign of alkalinity. It was then removed from the water, and roughly dried between folds of filter paper, and afterwards dried in an oven at 70° C. After three hours, however, an explosion took place, which entirely destroyed the strong copper oven in which the nitro- cotton (about one oz.) had been drying. The explosion was in some respects remarkable. The pyroxyline was the di-nitro-cellulose (or possibly the penta-nitro?), and the temperature was below the igniting point of this material (40° C. would have been a better temperature). Dr Weber determined the ignition point of his di-nitro-cellulose, and found it to be 194° to 198° C., and he is therefore of opinion that the explosion was due to the treatment of the partially washed material with ammonia. A certain quantity of ammonium nitrate was probably formed, and subsequently dried upon the nitro-cellulose, in a state of very fine subdivision. The faintest trace of acid would then be sufficient to bring about the explosive ignition of the ammonium nitrate. The drying of gun-cotton or collodion-cotton is also a somewhat dangerous operation. A temperature of 40° C. (104° F.) should not be exceeded, and thermometers should be placed in the nitro-cotton, and the temperature frequently observed. An electric alarm thermometer is also a useful adjunct to the cotton drying house. Great care must also be taken that there are no exposed hot-water pipes or stoves in the drying house, as the fine gun-cotton dust produced by the turning or moving of the material upon the shelves would settle upon such pipes or stoves, and becoming hot, would be very sensitive to the least friction. The floor also should be covered with linoleum or indiarubber. When hot currents of air are made to pass over the surface of gun-cotton, the gun-cotton becomes electrified. It is important, therefore, to provide some means to carry it away. Mr W.F. Reid, F.I.C., was the first to use metal frames, carriers, and sieves, upon which is secured the cloth holding the gun-cotton, and to earth them. The compression of gun-cotton into blocks, discs, &c., is also attended with considerable risk. Mr O. Guttmann, in an interesting paper upon "The Dangers in the Manufacture of Explosives" (_Jour. Soc. Chem. Ind._, No. 3, vol. xi., 1892), says: "The compression of gun-cotton into cartridges requires far more care than that of gunpowder, as this is done in a warm state, and gun-cotton even when cold, is more sensitive than gunpowder. When coming out of the centrifugal machines, the gun-cotton should always pass first through a sieve, in order to detect nails or matches which may by chance have got into it. What has been said as to gunpowder presses applies still more to those for gun-cotton, although the latter are always hydraulic presses. Generally the pistons fit the mould perfectly, that is to say, they make aspiration like the piston of a pump. But there is no metal as yet known which for any length of time will stand the constant friction of compression, and after some time the mould will be wider in that part where the greatest compression takes place. The best metal for this purpose has proved to be a special steel made by Krupp, but this also is only relatively better; for pistons I prefer hard cast iron. If the position of the moulds and pistons is not exactly the same in all cases, what the Germans call 'Ecken' (English 'binding') will take place, viz., the mould will stand obliquely to the piston, and a dangerous friction will result." "Of course, it is necessary to protect the man working the hydraulic valves during compression. At Waltham Abbey they have a curtain made of ship's hawsers, which is at the same time elastic and resistant." Mr Guttmann has found that a partition wall 12 inches thick, made of 2-inch planks, and filled with ground cinders, gives very effective protection. A door in this partition enables the workman to get to the press, and a conical tube penetrates the wall, enabling the man to see the whole work from a safe standpoint. The roof, or one side of the building, should be of glass, so as to give the explosion a direction. ~Trench's Fire-extinguishing Compound~ is manufactured by the Cotton Powder Company at Faversham, and is the invention of Mr George Trench, F.C.S., the manager of the Company. The object of the invention is to surround the cartridges of tonite, when used in coal mines, with a fire- extinguishing compound. If a charge of tonite, dynamite, or gelatine dynamite is put inside a few ounces of this mixture, and then fired, not the least trace of flame can be observed, and experiments appear to show that there is no flame at all. The compound consists of sawdust impregnated with a mixture of alum and chlorides of sodium and ammonia. Fig. 22 shows the manner of placing the tonite cartridge in the paper bag, and surrounding it with the fire-extinguishing compound, _aa_. The attachment of the fuse and detonator is also shown. [Illustration: FIG. 22.--TRENCH'S FIRE-EXTINGUISHING CARTRIDGE.] The following report (taken from the _Faversham News_, 22nd Oct. 1887) of experiments conducted in the presence of several scientific and mining men will show its value:--"A large wrought-iron tank, of 45 cubic feet capacity, had been sunk level with the ground in the middle of the yard; to this tank the gas had been laid on, for a purpose that will be explained later on. The charges were fired by means of electricity, a small dynamo firing machine being placed from 30 to 40 yards away from the 'mine.'" Operations were commenced by the top of the tank being covered over and plastered down in order to make it air-tight; then a sufficient quantity of coal gas was placed in it to make it highly inflammable and explosive, the quantity being ascertained by a meter which had been fixed specially for the purpose. Whilst the gas was being injected the cartridge was prepared. The first experiment was to try whether a small charge of tonite--fired without the patent extinguisher--would ignite the gas. The gas having been turned on, a miner's lamp was placed in the "tank," but this was extinguished before the full quantity of gas had gone through the meter. However, the gas being in, the charge of 1-1/4 oz. tonite was placed in the "mine," the detonator was connected by means of long wires to the dynamo machine, and the word was given to "fire." With a tremendous report, and a flash of fire, the covering of the mine flew in all directions, clearly showing that the gas had exploded. The next cartridge (a similar charge) was prepared with the patent compound. First of all a brown paper case of about 2 inches diameter was taken, and one of the tonite cartridges was placed in the centre of it, the intervening space between the charge and-the case being packed with the "fire-extinguishing compound." The mine having had another supply of gas injected, the protected cartridge was placed inside and fired. The result was astonishing, the explosion not being nearly so loud, whilst there was not the least flash of fire. "Protected" and "unprotected" charges were fired at intervals, gas being turned into the tank on each occasion. Charges of tonite varying from 1 to 6 oz. were also used with the compound. The report was trifling, whilst no flash could be seen. ~Uses of Collodion-Cotton.~--The collodion or soluble gun-cotton is used for a variety of purposes. The chief use is, however, for the manufacture of the various explosive gelatine compounds, of which blasting gelatine is the type. It is also very extensively used in the manufacture of smokeless powders, both military and sporting--in fact, very few of them do not contain it. In some, however, nitro-lignose or nitrated wood is used instead. This, however, is chemically the same thing, viz., nitro- cellulose, the cellulose being derived from the wood fibre. It is more used in this connection than the higher nitrate gun-cotton. Another use to which it has been applied very extensively, of recent years, is in the manufacture of "celluloid." It is used in photography for the preparation of the films on the sensitised plates, and many other purposes. Dissolved in a solution of two parts ether and one of alcohol, it forms the solution known as collodion, used for a variety of purposes, such as a varnish, as a paint for signals; in surgery, for uniting the edges of wounds. Quite lately, Mr Alfred Nobel, the well-known inventor of dynamite, has patented the use of nitro-cellulose, hydro- or oxy-cellulose, as an artificial substitute for indiarubber. For this purpose it is dissolved in a suitable non-volatile or slightly volatile "solvent," such as nitro- naphthalene, di-nitro-benzene, nitro-toluene, or its homologues; products are obtained varying from a gelatinous consistency to the hardness of ebonite. The proportions will vary from about 20 per cent. of nitro- cellulose in the finished product, forming a soft rubber, to 50 per cent. nitrating celluloid, and the "solvent" chosen will depend on the use to which the rubber substitute is to be put, the liquids giving a more elastic substance, whilst mixtures of solids and liquids may be employed when the product is to be used at high temperatures. By means of rollers steam heated, the incorporation may be accomplished without the aid of a volatile liquid, or the nitro-cellulose may be employed wet, the water being removed after "solution." It is advisable to use the cellulose nitrated only just enough to render it suitable, in order to reduce the inflammability of the finished product. Mr W. Allen, M.P., of Gateshead, proposed to use celluloid for cartridge cases, and thus to lighten ammunition, and prevent jambing, for the case will be resolved into gases along with the powder. Extractors will also be done away with. ~Celluloid~ is an intimate mechanical mixture of pyroxyline (gun-cotton or collodion-cotton) with camphor, first made by Hyatt, of Newark, U.S.A., and obtained by adding the pyroxyline to melted camphor, or by strongly compressing the two substances together, or by dissolving the constituents in an appropriate solvent, e.g., alcohol or ether, and evaporating to dryness. A combination of the two latter methods, i.e., partial solution, with pressure, is now usually adapted. The pyroxyline employed is generally the tetra- and penta-nitrated cellulose, the hexa-nitrate (gun-cotton) being but seldom used on account of its explosive properties. Care is taken to prevent the formation of the hexa-nitrate by immersing the cellulose in only moderately strong nitric acid, or in a warm mixture of nitric and sulphuric acids. The paper, either in small pieces or in sheets, is immersed for about twenty-five minutes in a mixture of 2 parts of nitric acid and 5 parts of sulphuric acid, at a temperature of about 30° C., after which the nitrated cellulose is thoroughly washed with water to remove the last traces of free acid, pressed, and whilst still moist, mixed with the camphor. In the process of Trebouillet and De Besancele, the cellulose, which may be in the form of paper, cotton, or linen, is twice nitrated--first in the acid mixture employed in a previous operation; and secondly, in a fresh mixture of 3 parts sulphuric acid of 1.83 specific gravity, and 2 parts concentrated nitric acid containing nitrous acid. After each nitration the mass is subjected to pressure, and is then carefully washed with water, to which, at the last, a small quantity of ammonia or caustic soda is added to remove the final traces of acid. The impregnation of the pyroxyline with the camphor is effected in a variety of ways. The usual proportion of the constituents is 2 parts pyroxyline and 1 part camphor. In Trebouillet and De Besancele's process, 100 parts of pyroxyline are intimately mixed with from 40 to 50 parts camphor, and moulded together by strong pressure in a hot press, and afterwards dried by exposure to air, desiccated by calcium chloride or sulphuric acid. The usual method is, however, to dissolve the camphor in the least possible quantity of alcohol, and sprinkle the solution over the dry pyroxyline, which is then covered with a second layer of pyroxyline, and the whole again treated with the camphor solution, the addition of pyroxyline and camphor solution being repeated alternately until the requisite amount of celluloid mixture is obtained. The mass, which sinks together in transparent lumps, is worked for about an hour between cold iron rollers, and then for the same period between rollers which can be gently heated by steam. The layer of celluloid surrounding the rollers is then cut away and again pressed, the resulting cake, which is now about 1 cm. thick, being cut into plates of about 70 cm. long and 30 cm. broad. These are placed one above the other, and strongly pressed together by hydraulic pressure at a temperature of about 70° for twenty-four hours. The thick cakes are once more cut into plates of the desired thickness, and placed in a chamber heated from 30° to 40° for eight to fourteen days, whereby they become thoroughly dry, and are readily made into various articles either by being moulded while warm under pressure, cut, or turned. Occasionally other liquids, e.g., ether and wood spirit, are used in place of alcohol as solvents for the camphor. Celluloid readily colours, and can be marbled for manufacturing purposes, &c. It is highly inflammable and not explosive even under pressure, and may be worked under the hammer or between rollers without risk. It softens in boiling water, and may be moulded or pressed. Its specific gravity varies slightly with its composition and with the degree of pressure it has received. It is usually 1.35. It appears to be merely a mixture of its components, since by treatment with appropriate solvents the camphor may be readily extracted, and on heating the pyroxyline burns away while the camphor volatilises. The manufacture of pyroxyline for the purpose of making celluloid has very much increased during recent years, and with this increase of production improved methods of manufacture have been invented. A series of interesting papers upon the manufacture of pyroxyline has been published by Mr Walter D. Field, of New York, in the _Journal of the American Chemical Society_[A] from which the following particulars are taken:-- [Footnote A: Vol. xv., No. 3, 1893; Vol. xvi., No. 7, 1894; Vol. xvi., No. 8, 1894. Figs. 19, 20, 21, 22, and 23 are taken from Mr Field's paper.] ~Selection of the Fibre.~--Cotton fibre, wood fibre, and flax fibre in the form of raw cotton, scoured cotton, paper, and rags are most generally used, and give the best results. As the fibres differ greatly in their structure, they require different methods of nitrating. The cotton fibre is a flattened hollow ribbon or collapsed cylindrical tube, twisted a number of times, and closed at one end to form a point. The central canal is large, and runs nearly to the apex of the fibre. Its side walls are membraneous, and are readily penetrated by the mixed acids, and consequently the highest nitration results. In the flax fibre the walls are comparatively thick, the central canal small; hence it is to be presumed that the nitration must proceed more slowly than in the case of cotton. The New Zealand flax gives the most perfectly soluble nitrates of any of the flaxes. Cotton gives a glutinous collodion, and calico a fluid collodion. One of the largest manufacturers of pyroxyline in the States uses the "Memphis Star" brand of cotton. This is an upland cotton, and its fibres are very soft, moist, and elastic. Its colour is light creamy white, and is retained after nitration. The staple is short, and the twist inferior to other grades, the straight ribbon-like filaments being quite numerous. This cotton is used carded, but not scoured. This brand of cotton contains a large quantity of half and three-quarter ripe fibre, which is extremely thin and transparent, distributed throughout the bulk of the cotton (Monie., Cotton Fibre, 67). Mr Field says, "This is a significant fact when it is known that from this cotton an extremely soluble pyroxyline can be produced." Pyroxyline of an inferior grade as regards colour only can be produced from the cotton wastes of the trade. They must be scoured before they are fit for nitrating. Paper made from the pulps of sulphite and sulphate processes is capable of yielding a very soluble pyroxyline. It can be nitrated at high temperatures and still yield good results. Tissue paper made from flax fibre is also used after being cut into squares. Mowbray (U.S.P., No. 443, 105, 3rd December 1890) says that a pure cotton tissue paper less than 1/500 inch in thickness, thin as it is, takes on a glutinous or colloid surface, and thus requires some thirty minutes to enable the nitration to take place. With a thicker paper only the surface would be nitrated. He therefore uses a fibre that has been saturated with a solution of nitrate of soda, and afterwards dried slowly, claiming that the salt crystallises in the fibre, or enters by the action termed osmose, and opens up the fibre to the action of the acid. This process would only be useful when the cotton is to be nitrated at a low temperature. At a high temperature it would be unnecessary. Dietz and Wayne (U.S.P., No. 133, 969) use ramie, rheca, or China grass for producing a soluble pyroxyline. That made from ramie is always of uniform strength and solubility, and requires a smaller quantity of solvent to dissolve it than that made from cotton. Mr Field's experience, however, is entirely contrary to this statement. Such is the influence of the physical form of the fibre on the process of nitration, that when flax fibre and cotton fibre are nitrated with acid mixtures of exactly the same strength, and at the same temperature, the solution of the first is glutinous or thick, and the second fluid or thin. By simply nitrating at a higher temperature than the cotton, the flax will yield a pyroxyline giving an equally fluid collodion. The presence of chlorine in the fibre must be carefully avoided, as such a fibre will yield an acid product which cannot be washed neutral. The fibre must be dry before nitration; and this is best done, according to Mr Field, by using the form of drier used in drying wool. ~Nitration of the Fibre.~--Mixed cotton and flax fibre in the form of paper, from 2/1000 to 3/1000 inch thick, and cut into 1-inch squares, is nitrated by the Celluloid Manufacturing Company, and the same paper, left in long strips, 1 inch wide, is used for nitration by the Xylonite Manufacturing Company, of North Adams, Mass. (U.S.A.). The Celluloid Company introduce the cut paper into the mixed acids by means of a hollow, rapidly revolving tube, flared at the lower end, and immersed in the mixed acids. The centrifugal force of the revolving tube throws the paper towards the sides of the vessel, leaving the centre of the vessel ready for fresh paper. The Xylonite Company simply cut the paper into long strips, and introduce it into the mixed acids by means of forks. The arrangement used by this Company for holding the mixed acids is a cylindrical vessel divided into a number of sections, the whole revolving like a turntable, thus allowing the workman to nitrate successively each lot of paper at a given point. This Company did not remove the acid from the paper after its immersion, but plunged it immediately into the water, thus losing a large proportion of the waste acid. The Celluloid Company, by using the paper in smaller pieces, and more paper to a pound of acid, and wringing the mixed acid from the paper before immersion in water, had a better process of nitration. Other manufacturers use earthenware vessels, and glass or steel rods, hooked at one end, having small pieces of rubber hose pulled over the other end to prevent the hand from slipping. The form of vessel in general use is that given in Fig. 23. It is large enough to nitrate 1 lb. of cotton at a time. The hook at one end of the rod enables the workman to pull the pyroxyline apart, and thus ensures saturation of the fibre. In the winter the room in which the nitrating is done must be kept at a temperature of about 70° F. in order to secure equality in the batches. [Illustration: FIG. 23.--VESSEL FOR NITRATING COTTON OR PAPER.] The nitrating apparatus of White and Schupphaus (U.S.P., No. 418, 237, 89) Mr Field considers to be both novel and excellent. The cage (Fig. 24), with its central perforated cylinder (Fig. 25), is intended to ensure the rapid and perfect saturation of the tissue paper used for nitrating. The patentees say that no stirring is required with their apparatus. This, says Mr Field, might be true when paper is used, or even cotton, when the temperature of nitration is from 30° to 35° C., but would not be true if the temperature were raised to 50° to 55° C. The process is as follows:-- The paper is nitrated in the cage (Fig. 25), the bottom of which is formed by the flanged plate C, fastened to the bottom of the internal cylinder B. After nitration the cage is carried to a wringer, which forms the basket, and the acids removed. Finally, the cage is taken to a plunge tank, where the paper is removed from the cage by simply pulling out the central perforated cylinder B. Fig. 26 shows the nitrating pot, with its automatic cover. The plunge tank is shown in plan and section in Figs. 28 and 29. This apparatus is suitable for the nitration of cotton fibre in bulk at high or low temperatures. Other methods that have been patented are Mowbray's (U.S.P., No. 434, 287), in which it is proposed to nitrate paper in continuous lengths, and Hyatt's (U.S.P., No. 210, 611). [Illustration: FIG. 24.--CENTRAL PERFORATED CYLINDER.] [Illustration: FIG. 25.--THE CAGE. WHITE AND SCHUPPHAUS' NITRATING APPARATUS.] [Illustration: FIG. 26.--CELLULOID NITRATING POT.] [Illustration: FIG. 27.--ANOTHER VIEW.] [Illustration: FIGS. 28, 29.--PLUNGE TANK, IN PLAN AND SECTION.] ~The Acid Mixture.~--Various formulæ have been published for producing soluble nitro-cellulose. In many instances, although the observations were correct for the single experiment, a dozen experiments would have produced a dozen different products. The composition of the acids used depends upon the substance to be nitrated, and the temperature at which the nitration will be worked. Practically there are three formulæ in general use--the one used by the celluloid manufacturers; another in which the cotton is nitrated at high temperatures; and a third in which the temperature of the immersion is low, and the time of nitration about six hours. Of the three, the best method is the last one, or the one in which the cotton is immersed at a low temperature, and then the reaction allowed to proceed in pots holding from 5 to 10 lbs. of cotton. The formula used by the celluloid manufacturers for the production of the low form of nitrated product which they use is:-- Sulphuric acid 66 parts by weight. Nitric acid 17 " " Water 17 " " Temperature of immersion, 30° C. Time, twenty to thirty minutes. The cellulose is used in the form of tissue paper 2/1000 inch thick, 1 lb. to 100 of acid mixture. The nitro-cellulose produced by this formula is very insoluble in the compound ethers and other solvents of pyroxyline, and is seemingly only converted or gelatinised by the action of the solvent. The next formula produces a mixture of tetra-and penta-nitro- celluloses hardly soluble in methyl-alcohol (free from acetone), but very soluble in anhydrous compound ethers, ketones, and aldehydes:-- Nitric acid, sp. gr. 1.435 8 lbs. Sulphuric acid, sp. gr. 1.83 15-3/4 lbs. Cotton 14 oz. Temperature of nitration, 60° C. Time of immersion, forty-five minutes. The 60° of temperature is developed by mixing the acids together. The cotton is allowed to remain in the acid until it feels "short" to the rod. The following table, due to Mr W.D. Field, shows very plainly the great variation in the time of the immersion and the temperature by seemingly very slight causes. It extends over fourteen working days, during which time it rained four days. The formula used is that given above, except that the specific gravity of the nitric acid is somewhat lower. The product obtained differs only from that produced by using nitric acid of specific gravity 1.43 in being soluble in methyl-alcohol. From 30 to 35 lbs. of pyroxyline were produced in each of the fourteen days. A careful examination of this table will prove very instructive. The increase in yield varies from 31 per cent. to nothing, and the loss runs as high as 10 per cent., yet care was taken to make the product uniform in quality. On the days it rained there was a loss, with the exception of the fourth day, when there was neither a loss nor a gain. On the days it was partly clear, as just before or after rain, the table shows a loss in product. We can explain this fact by reason of the moisture-absorbing qualities of the cotton. On the rainy days it would absorb the moisture from the air until, when immersed in the acids, they were weakened, and the fibre dissolved more or less in weakened acid, producing what is known as "burning" in the batch. It will also be noticed that on days which show a loss, the time of the immersion was correspondingly short, as on the a loss, the time of the immersion was correspondingly short, as on the tenth, twelfth, and seventh days. ______________________________________________________________________ | | | | | | Specific Gravity. | Time. | | |_____________________|_______________________________| | | | | | | | | | |H_{2}S0_{4}.|HNO_{3}.|Hours.|Minutes.|Hours.|Minutes.| |________________|____________|________|______|________|______|________| | | | | | | | | | 1. Clear | 1.838 | 1.4249 | ... | 20 | 4 | ... | | 2. " | 1.837 | 1.4249 | ... | 20 | 2 | ... | | 3. Cloudy | 1.837 | 1.4226 | ... | 45 | 2 | ... | | 4. Rain | 1.837 | 1.420 | ... | 20 | 1 | 20 | | 5. Clear | 1.8377 | 1.42 | 1 | 15 | 2 | ... | | 6. Rainy | 1.8391 | 1.422 | ... | 35 | 1 | 40 | | 7. Cloudy | 1.835 | 1.4226 | ... | 20 | ... | 35 | | 8. Clear | 1.835 | 1.422 | ... | 35 | 1 | 10 | | 9. Partly Clear| 1.824 | 1.4271 | ... | 20 | 1 | ... | |10. " | 1.83 | 1.4271 | ... | 10 | ... | 25 | |11. Cloudy | 1.832 | 1.425 | ... | 10 | ... | 50 | |12. Rainy | 1.822 | 1.425 | ... | 10 | ... | 20 | |13. Partly CLear| 1.8378 | 1.4257 | ... | 60 | 1 | 40 | |14. Cloudy | 1.837 | 1.4257 | 1 | 56 | 4 | 40 | |________________|____________|________|______|________|______|________| | | | | | |Temp., Deg. C. | Percentage | | |_______________|___________________| | | | | | | | | From | To | Increase. | Loss. | |________________|_______|_______|___________|_______| | | | | | | | 1. Clear | 57° | 62° | 31 | ... | | 2. " | 60° | 62° | 18 | ... | | 3. Cloudy | 60° | 62° | 7 | ... | | 4. Rain | 60° | 63° | 0 | 0 | | 5. Clear | 58° | 62° | 15 | ... | | 6. Rainy | 58° | 62° | ... | 2 | | 7. Cloudy | 62° | 65° | ... | 10 | | 8. Clear | 60° | 62° | 5 | ... | | 9. Partly Clear| 50° | 60° | ... | 3 | |10. " | 58° | 60° | ... | 10 | |11. Cloudy | 58° | 60° | 8 | ... | |12. Rainy | 58° | 60° | ... | 10 | |13. Partly CLear| 50° | 58° | 20 | ... | |14. Cloudy | 50° | 60° | 16 | ... | |________________|_______|_______|___________|_______| The lesson this table teaches is, that it is almost impossible to nitrate cellulose in small quantities, and get uniform results, when the nitration is carried on at high temperatures. As regards the solubility of pyroxyline, Parks found that nitro-benzene, aniline, glacial acetic acid, and camphor, dissolved in the more volatile solvents methyl-alcohol and alcohol-ether, were much the best solvents for producing a plastic, as they are less volatile, and develop greater solvent action under the influence of heat. Nitro-benzene gives a solution that is granular; it seems to merely convert the pyroxyline, and not to dissolve it; but on the addition of alcohol, a solution is at once obtained, and the granular appearance disappears, and the solution becomes homogeneous. The acid mixture and the method of nitrating have much to do with the action of the various solvents, so also has the presence of water. Dr Schupphaus found that propyl and isobutyl alcohols with camphor were active solvents, and the ketones, palmitone, and stearone in alcohol solution, also alpha- and beta-naphthol, with alcohol and anthraquinone (diphenylene diketone) in alcoholic solution, and also iso-valeric aldehyde and its derivatives, amyliden-dimethyl and amyliden-diethyl ethers. August Sayer (U.S.P., No. 470,451) finds diethyl-ketone, dibutyl-ketone, di-pentyl-ketone, and the mixed ketones,[A] methyl-ethyl, methyl-propyl, methyl-butyl, methyl-amyl, and ethyl-butyl ketones are active solvents of pyroxyline; and Paget finds that although methyl-amyl oxide is a solvent, that ethyl-amyl oxide is not. [Footnote A: Ketones are derived from the fatty acids by the substitution of the hydroxyl of the latter by a monad positive radical. They thus resemble aldehydes in constitution. The best-known ketone is acetone CH_{3}CO.CH_{3}. Mixed ketones are obtained by distilling together salts of two different fatty acids. Thus potassic butyrate and potassic acetate form propyl-methyl-ketone-- C(C_{2}H_{5})H_{2} | CO.CH_{3}] The solvents of pyroxyline can be divided into general classes--First, those which are solvents without the aid of heat or solution in alcohol; second, those that are solvents when dissolved in alcohol. These solvents are those which also develop a solvent action when heated to their melting point in combination with pyroxyline. Mr W.D. Field groups the solvents of pyroxyline into classes thus: Two of the monohydric alcohols; compound ethers of the fatty acids with monohydric alcohols, aldehydes; simple and mixed ketones of the fatty acid series. These four classes include the greater number of the solvents of pyroxyline. Those not included are as follows:--Amyl-nitrate and nitrite, methylene-di-methyl ether, ethidene-diethyl ether, amyl-chloracetate, nitro-benzene and di-nitro-benzene, coumarin, camphor, glacial acetic acid, and mono-, di-, and tri-acetin. Richard Hale uses the following solvent:--Amyl-acetate, 4 volumes; petroleum naphtha, 4 volumes; methyl-alcohol, 2 volumes; pyroxyline, 4 to 5 ounces to the gallon of solvent. Hale used petroleum naphtha to hasten the drying qualities of the varnish, so that it would set on the article to be varnished before it had a chance to run off. It is, however, the non-hygroscopic character of the solvent that makes the varnish successful. This formula is very largely used for the production of pyroxyline varnish, which is used for varnishing pens, pencils, &c., also brass-work and silver-ware. The body known as oxy-cellulose[A] is formed by the action of nitric acid upon cellulose when boiled with it. The quantity formed is about 30 per cent. of cellulose acted upon. When washed free from acid, it gelatinises. It is then soluble in dilute alkalies, and can be reprecipitated from solution by alcohol, acids, or saline solutions. Messrs Cross and Bevan assign to it the formula C_{18}H_{26}O_{16}. It dissolves in concentrated sulphuric acid, and with nitric acid forms a nitro body of the formula C_{18}H_{23}O_{16}3(NO_{2}), which is prepared as follows:--The gelatinous oxy-cellulose is washed with strong nitric acid until free from water, and is then diffused through a mixture of equal volumes of strong sulphuric and nitric acids, in which it quickly dissolves. The solution, after standing for about an hour, is poured in a fine stream into a large volume of water, by which the "nitro" body is precipitated as a white flocculent mass. The product, after drying at 110° C., was found upon analysis to contain 6.48 per cent. nitrogen. [Footnote A: "On the Oxidation of Cellulose," by C.F. Cross and E.J. Bevan, _Jour. Chem. Soc._, 1883, p. 22.] MISCELLANEOUS NITRO-EXPLOSIVES. ~Nitro-Starch.~--It is only recently that, by means of the process introduced by the "Actiengesellschaft Dynamit Nobel," it has been possible to make this explosive upon the manufacturing scale. Nitro-starch has been known since 1883, when Braconnot discovered it, and called it xyloidine. Its formula is C_{6}H_{8}O_{3}(NO_{3})_{2}, but Dr Otto Mühlhäusen has lately succeeded in preparing higher nitrated compounds, viz.:-- (_a._) C_{6}H_{7-1/2}O_{2-1/2}(NO_{3})_{2-1/2}. (_b._) C_{6}H_{7}O_{4}(NO_{3})_{3}. Or doubling the molecule of starch:-- Nitrogen. i. Tetra-nitro-starch C_{12}H_{16}O_{6}(ONO_{2})_{4} 11.11 per cent. ii. Penta-nitro-starch C_{12}H_{15}O_{5}(ONO_{2})_{5} 12.75 " iii. Hexa-nitro-starch C_{12}H_{14}O_{4}(ONO_{2})_{6} 14.14 " He regards them as true ethers (esters) of nitric acid. Thus on treatment with sulphuric acid, these compounds yield NO_{3}H, the residue O.NO_{2} thus appearing to be replaced by the sulphuric acid residue. On treatment with a solution of ferrous chloride, nitric oxide and "soluble" starch are regenerated. On shaking with sulphuric acid over mercury, all the nitrogen is split off as NO. Tetra-nitro-starch is prepared upon the large scale as follows:--A quantity of potato-starch is taken and exposed in some suitable desiccating apparatus at a temperature of 100° C. until all the moisture which it contains is completely driven off. It is then reduced to a fine powder by grinding, and dissolved in nitric acid of specific gravity 1.501. The vessel in which this solution is accomplished is made of lead, and must be provided with two jackets, cooled by means of water. It should further be fitted with a screw-agitator, in order to keep the nitric acid circulating freely. The charge of starch is introduced through an opening in the cover of this digesting vessel, and the proportions of acid to starch are 10 kilogrammes of starch to 100 kilos. of acid. The temperature is kept within the limits 20° to 25° C. When the solution of the starch is complete, the liquid is conducted into a precipitating apparatus, which is also provided with a cooling jacket, for the purpose of regulating the temperature. The bottom of this vessel is double and perforated, and here is placed a layer of gun-cotton to act as a filter. This vessel is filled with spent nitro-sulphuric acid obtained as a waste product from the nitro-glycerine manufactory, and the solution of starch in nitric acid is sprayed into it through an injector worked by compressed air, whereby the nitro-starch is thrown down in the form of a fine-grained powdery precipitate. In order to precipitate 100 kilos. of the acid solution of starch, it is necessary to employ 500 kilos. of spent nitro-sulphuric acid. As it is precipitated the nitro-starch collects on the gun-cotton filter, and the acid liquor is run off through a tap placed beneath the perforated double bottom of the vessel, and of course below the filter pad. The precipitated starch is further cleansed from acid by repeated washings and by pressure, until all trace of acidity has been eliminated, and the substance exhibits a neutral reaction. The next step is to treat the nitro-starch with a 5 per cent. solution of soda, in contact with which it is allowed to stand for at least twenty-four hours. The product is then ground up until a sort of "milk" or emulsion is obtained, and lastly treated with a solution of aniline, so that when pressed into cake, it contains about 33 per cent. of water, and 1 per cent. of aniline. Dr Mühlhäusen, working on these lines in the laboratory, prepared nitro- starch which contained 10.96 and 11.09 per cent. of nitrogen. When in the state of powder it is snow-white in colour; it becomes electrified when rubbed; it is very stable, and soluble even in the cold in nitro- glycerine. He has also prepared a tetra-nitro-starch containing 10.58 and 10.50 per cent. of nitrogen, by pouring water into a solution of starch in nitric acid which had stood for several days. The substance thus produced in the laboratory had all the properties of that prepared by the other process. The production of penta-nitro-starch is effected by adding 20 grms. of rice-starch--previously dried at a temperature of 100°C., in order to eliminate all moisture--to a mixture of 100 grms. of nitric acid, specific gravity 1.501, and 300 grms. of sulphuric acid, specific gravity 1.8 (some tetra-nitro-starch is also formed at the same time). After standing in contact with these mixed acids for one hour the starch has undergone a change, and the mass may now be discharged into a large quantity of water, and then washed, first with water, and finally with an aqueous solution of soda. The yield in Dr Mühlhäusen's experiments was 147.5 per cent. The substance thus formed is now heated with ether-alcohol, the ether is distilled off, and the penta-nitro-starch appears as a precipitate, whilst the tetra-nitro-starch, which is formed simultaneously, remains in solution in the alcohol. As obtained by this process, it contained 12.76 and 12.98 per cent. nitrogen, whilst the soluble tetra-nitro-starch contained 10.45 per cent. Hexa-nitro-starch is the product chiefly formed when 40 grms. of dry starch are treated with 400 grms. of nitric acid, specific gravity 1.501, and allowed to stand in contact for twenty-four hours; 200 grms. of this mixture are then poured into 600 c.c. of sulphuric acid of 66° B. The result of this manipulation is a white precipitate, which contains 13.52-13.23 and 13.22 per cent. nitrogen; and consists, therefore, of a mixture of penta- and hexa-nitro-starch. The experiments undertaken with these substances demonstrated that those prepared by precipitating the nitro-starch with strong sulphuric acid were less stable in character or properties than those which were precipitated by water or weak sulphuric acid. Dr Mühlhäusen is of opinion that possibly in the former case a sulpho-group may be formed, which in small quantity may occasion this instability. The following table shows the behaviour of these substances prepared in different ways and under various conditions:-- __________________________________________________________________ | | | | | SAMPLES. | | |____________________________________________| | | | | | | | | | A. | B. | C. | D. | E. | | Ignition-point |175° C. |170° C. |152° C. |121° C. |155° C. | | Stability |Stable |Stable |Unstable|Unstable|Unstable| | Per cent. of N. | 11.02 | 10.54 | 12.87 | 12.59 | 13.52 | | 96 per cent. alcohol| Sol. | Sol. | Insol. | Insol. | Insol. | | Ether | Insol. | Insol. | Insol. | Insol. | Insol. | | Ether-alcohol | Sol. | Sol. | Sol. | Sol. | Sol. | | Acetic Ether | Sol. | Sol. | Sol. | Sol. | Sol. | |_____________________|________|________|________|________|________| These samples were prepared as follows:-- A. From 1 part nitric acid and 2 parts sulphuric acid (containing 70 per cent. H_{2}O). B. From 1 part nitric acid and water. C. From 1 part nitric and 3 parts H_{2}SO_{4} (con.). D. From 1 part nitric and 3.5 parts con. H_{2}SO_{4}. E. From 1 part nitric and 3 parts con. H_{2}SO_{4}. Dr Mühlhäusen is of opinion that these compounds may be turned to practical account in the production of good smokeless powder. He recommends the following proportions and method. Six grms. of nitro-jute and 2 grms. of nitro-starch are mixed together, and moistened with acetic ether. These ingredients are then worked together into a uniform mass, and dried at a temperature ranging between the limits 50° to 60° C. He has himself prepared such a smokeless powder, which proved to contain 11.54 per cent. of nitrogen, and was very stable. Further details of Dr Mühlhäusen's work upon nitro-starch can be found in _Dingler's Polytechnisches Journal_, paper "Die höhren Salpetersäureäther der Stärke," 1892, Band 284, s. 137-143, and a Bibliography up to 1892 in _Arms and Explosives_, December 1892. M. Berthelot gives the heat of formation of nitro-starch as 812 cals. for 1 grm., and the heat of total combustion as equal to 706.5 cals. for 207 grms., or for 1 grm. 3,413 cals. The heat of decomposition could only be calculated if the products of decomposition were given, but they have not as yet been studied, and the quantity of oxygen contained in the compound is far from being sufficient for its complete combustion. Berthelot and Vieille found the average velocities for nitro-starch powder, density of charge about 1.2, in a tin tube 4 mm. external diameter, to be, in two experiments, 5,222 m. and 5,674 m. In a tin tube 5.5 mm. external diameter, the velocity was 5,815 m., and in lead tube 5,006 m. (density 1.1 to 1.2). The starch powder is hygroscopic, and is insoluble in water and alcohol. When dry it is very explosive, and takes fire at about 350° F. Mr Alfred Nobel has taken out a patent (Eng. Pat. No. 6,560, 88) for the use of nitro-starch. His invention relates to the treatment of nitro- starch and nitro-dextrine, for the purpose of producing an explosive powder, to be used in place of gunpowder. He incorporates these materials with nitro-cellulose, and dissolves the whole in acetone, which is afterwards distilled off. A perfect incorporation of the ingredients is thus brought about. ~Nitro-Jute.~--It is obtained by treating jute with nitric acid. Its properties have been studied by Messrs Cross and Bevan (_Jour. Chem. Soc._, 1889, 199), and by Mühlhäusen. The latter used for its nitration an acid mixture composed of equal parts of nitric and sulphuric acids, which was allowed to act upon the jute for some time. He found that with long exposure, i.e., from three to four hours in the acids, there was a disintegrating of the fibre-bundles, and the nitration was attended by secondary decomposition and conversion into products soluble in the acid mixture. Cross and Bevan's work upon this subject leads them to conclude that the highest yield of nitrate is represented by an increase of weight of 51 per cent. They give jute the empirical formula C_{12}H_{18}O_{9} (C = 47 per cent. H = 6 per cent., and O = 47 per cent.), and believe its conversion into a nitro compound to take place thus:-- C_{12}H_{18}O + 3HNO_{3} = C_{12}H_{15}O_{6}(NO_{3})_{3} + 3H_{2}O. This is equivalent to a gain in weight of 44 per cent. for the tri- nitrate, and of 58 per cent. for the tetra-nitrate. The formation of the tetra-nitrate appears to be the limit of nitration of jute-fibre. In other words, if we represent the ligno-cellulose molecule by a C_{12} formula, it will contain four hydroxyl (OH) groups, or two less than cellulose similarly represented. The following are their nitration results:-- Acids used.--I. HNO_{3} sp. gr. 1.43, and H_{2}SO_{4} = 1.84 equal parts. II. 1 vol. HNO_{3}(1.5), 1 vol. H_{2}SO_{4}(1.84). III. 1 vol. HNO_{3}(1.5), 75 vols. H_{2}SO_{4}(1.84). I. = 144.4; II. = 153.3; III. = 154.4 grms.; 100 grms. of fibre being used in all three cases. Duration of exposure, thirty minutes at 18° C. The nitrogen was determined in the products, and equalled 10.5 per cent. Theory for C_{12}H_{15}O_{6}(NO_{3})_{3} = 9.5 per cent. and for C_{12}H_{15}O_{6}(NO_{3})_{4} = 11.5 per cent. These nitrates resemble those of cellulose, and are in all essential points nitrates of ligno- cellulose. Mühlhäusen obtained a much lower yield, and probably, as pointed out by Cross and Bevan, a secondary decomposition took place, and his products, therefore, probably approximate to the derivatives of cellulose rather than to those of ligno-cellulose, the more oxidisable, non-cellulose, or lignone constituents having been decomposed. In fact, he regards his product as cellulose penta-nitrate (C_{12}H_{16}O_{5}(ONO_{2})_{5}). The _Chemiker Zeitung_, xxi., p. 163, contains a further paper by Mühlhäusen on the explosive nitro-jute. After purifying the jute-fibre by boiling it with a 1 per cent. solution of sodium carbonate, and washing with water, he treated 1 part of the purified jute with 15 parts of nitro-sulphuric acid, and obtained the following results with different proportions of nitric to sulphuric acids:-- Yield Ignition Nitrogen. per cent. Point. Experiment I.-- 1. HNO_{3} 1. H_{2}SO_{4} 129.5 170° C. 11.96% " II. " 2. " 132.2 167° C. 12.15% " III. " 3. " 135.8 169° C. 11.91% An experiment made with fine carded jute and the same mixture of acids as in No. II. gave 145.4 per cent. nitro-jute, which ignited at 192° C., and contained 12 per cent. nitrogen. This explosive is not at present manufactured upon the large scale, and Messrs Cross and Bevan are of opinion that there is no very obvious advantage in the use of lignified textile fibre as raw materials for explosive nitrates, seeing that a large number of raw materials containing cellulose (chiefly as cotton) can be obtained at a cheaper rate, and yield also 150 to 170 per cent. of explosive material when nitrated, and are in many ways superior to the products obtained hitherto from jute. ~Nitro-mannite~ is formed by the action of nitric acid on mannite, a hex-acid alcohol closely related to sugar. It occurs abundantly in manna, which is the partly dried sap of the manna-ash (_Fraxinus ornus_). It is formed in the lactic acid fermentation of sugar, and by the action of nascent hydrogen on glucose and cellulose, or on invert sugar. Its formula is C_{6}H_{8}(OH)_{6} and that of nitro-mannite C_{6}H_{8}(NO_{3})_{6}. Mannite crystallises in needles or rhombic prisms, which are soluble in water and alcohol, and have a sweet taste. Nitro-mannite forms white needle-shaped crystals, insoluble in water, but soluble in ether or alcohol. When rapidly heated, they ignite at about 374° F., and explode at about 590° F. It is more susceptible to friction and percussion than nitro-glycerine, and unless pure it is liable to spontaneous decomposition. It is considered as the nitric ether of the hexatomic alcohol mannite. It is formed by the action of a mixture of nitric and sulphuric acids upon mannite-- C_{6}H_{8}(OH)_{6} + 6HNO_{3} = C_{6}H_{8}(NO_{3})_{6} + 6H_{2}O. Its products of explosion are as shown in the following equation:-- C_{6}H_{8}(OH)_{6} = 6CO_{2} + 4H_{2}O + 3N_{2} + O_{2}. Its percentage composition is as follows:--Carbon, 15.9 per cent.; hydrogen, 1.8 per cent.; nitrogen, 18.6 per cent.; and oxygen, 63.7 per cent. Its melting point is 112 to 113° C., and it solidifies at 93°. When carefully prepared and purified by recrystallisation from alcohol, and kept protected from sunlight, it can be kept for several years without alteration. Nitro-mannite is more dangerous than nitro-glycerine, as it is more sensitive to shock. It is intermediate in its shattering properties between nitro-glycerine and fulminate of mercury. It explodes by the shock of copper on iron or copper, and even of porcelain on porcelain, provided the latter shock be violent. Its heat of formation from its elements is +156.1 calories. It is not manufactured upon the commercial scale. Besides the nitro compounds already described, there are many others, but they are of little importance, and are none of them made upon the large scale. Among such substances are _nitro-coal_, which is made by the action of nitric acid on coal; _nitro-colle_, a product which results from the action of nitric acid on isinglass or gelatine, soaked in water. It is then treated with the usual acids. Another method is to place strong glue in cold water until it has absorbed the maximum amount of the latter. The mixture is solidified by the addition of nitric acid, nitrated in the usual way, and well washed. Abel's _Glyoxiline_ is only nitrated gun-cotton impregnated with nitro- glycerine. Nitro-lignine is only nitro-cellulose made from wood instead of cotton; and nitro-straw is also only nitro-cellulose. The explosive known as _Keil's Explosive_ contains nitro-glucose. Nitro-molasses, which is a liquid product, has also been proposed, and nitro-saccharose, the product obtained by the nitration of sugar. It is a white, sandy, explosive substance, soluble in alcohol and ether. When made from cane sugar, it does not crystallise; but if made from milk sugar, it does. It has been used in percussion caps, being stronger and quicker than nitro-glycerine. It is, however, very sensitive and very hygroscopic, and very prone to decomposition. Nitro-tar, made from crude tar-oil, by nitration with nitric acid of a specific gravity of 1.53 to 1.54. Nitro-toluol is used, mixed with nitro-glycerine. This list, however, does not exhaust the various substances that have been nitrated and proposed as explosives. Even such unlikely substances as horse dung have been experimented with. None of them are very much used, and very few of them are made upon the manufacturing scale. CHAPTER IV. _DYNAMITE AND GELATINES._ Kieselguhr Dynamite--Classification of Dynamites--Properties and Efficiency of Ordinary Dynamite--Other Forms of Dynamite--Gelatine and Gelatine Dynamites, Suitable Gun-Cotton for, and Treatment of--Other Materials used--Composition of Gelignite--Blasting Gelatine--Gelatine Dynamite--Absorbing Materials--Wood Pulp--Potassium Nitrate, &c.-- Manufacture and Apparatus used, and Properties of Gelatine Dynamites-- Cordite--Composition and Manufacture. ~Dynamite.~--Dynamite consists of nitro-glycerine either absorbed by some porous material, or mixed with some other substance or substances which are either explosives or merely inert materials. Among the porous substances used is kieselguhr, a silicious earth which consists chiefly of the skeletons of various species of diatoms. This earth occurs in beds chiefly in Hanover, Sweden, and Scotland. The best quality for the purpose of manufacturing dynamite is that which contains the largest quantity of the long tubular _bacillariæ_, and less of the round and lancet-shaped forms, such as _pleurosigmata_ and _diclyochæ_, as the tube-shaped diatoms absorb the nitro-glycerine better, and it becomes packed into the centre of the silicious skeleton of the diatoms, the skeleton acting as a kind of tamping, and increasing the intensity of the explosion. Dynamites are classified by the late Colonel Cundill, R.A., in his "Dictionary of Explosives" as follows:-- 1. Dynamites with an inert base, acting merely as an absorbent. 2. Dynamites with an active base, i.e., an explosive base. No. 2 may be again divided into three minor classes, which contain as base-- (_a._) Charcoal. (_b._) Gunpowder or other nitrate, or chlorate mixture. (_c._) Gun-cotton or other nitro compound (nitro-benzol, &c.). The first of these, viz., charcoal, was one of the first absorbents for nitro-glycerine ever used; the second is represented by the well-known Atlas powder; and the last includes the well-known and largely used gelatine compounds, viz., gelignite and gelatine dynamite, and also tonite No. 3, &c. In the year 1867 Nobel produced dynamite by absorbing the nitro-glycerine in an inert substance, forming a plastic mass. In his patent he says: "This invention relates to the use of nitro-glycerine in an altered condition, which renders it far more practical and safe for use. The altered condition of the nitro-glycerine is effected by causing it to be absorbed in porous unexplosive substances, such as charcoal, silica, paper, or similar materials, whereby it is converted into a powder, which I call dynamite, or Nobel's safety powder. By the absorption of the nitro- glycerine in some porous substance it acquires the property of being in a high degree insensible to shocks, and it can also be burned over a fire without exploding." Ordinary dynamite consists of a mixture of 75 per cent. of nitro-glycerine and 25 per cent. of kieselguhr. The guhr as imported (Messrs A. Haake & Co. are the chief importers) contains from 20 to 30 per cent. of water and organic matter. The water may be very easily estimated by drying a weighed quantity in a platinum crucible at 100° C. for some time and re-weighing, and the organic matter by igniting the residue strongly over a Bunsen burner. Before the guhr can be used for making dynamite it must be calcined, in order not only to get rid of moisture, but also the organic matter. A good guhr should absorb four times its weight of nitro-glycerine, and should then form a comparatively dry mixture. It should be pale pink, red brown, or white. The pink is generally preferred, and it should be as free as possible from grit of all kinds, quartz particles, &c., and should have a smooth feeling when rubbed between the finger and thumb, and should show a large quantity of diatoms when viewed under the microscope. The following was the analysis of a dried sample of kieselguhr:--Silica, 94.30; magnesia, 2.10; oxide of iron and alumina, 1.3; organic matter, 0.40; moisture, 1.90 per cent. The guhr is generally dried in a reverberatory muffle furnace. It is spread out on the bottom to the thickness of 3 or 4 inches, and should every now and then be turned over and raked about with an iron rabble or hoe. The temperature should be sufficiently high to make the guhr red hot, or the organic matter will not be burnt off. The time occupied in calcining will depend of course upon the quality of the guhr being operated upon. Those containing a high percentage of water and organic matter will of course take longer than those that do not. A sample of the calcined guhr should not contain more than 0.5 per cent. of moisture and organic matter together. After the guhr is dry it requires to be sifted and crushed. The crushing is done by passing it between iron rollers fixed at the bottom of a cone or hopper, and revolving at a moderate speed. Beneath the rollers a fine sieve should be placed, through which the guhr must be made to pass. The kieselguhr having been dried, crushed, and sifted, should be packed away in bags, and care should be taken that it does not again absorb moisture, as if it contains anything above about five-tenths per cent. of water it will cause the dynamite made with it to exude. The guhr thus prepared is taken up to the danger area, and mixed with nitro-glycerine. The nitro-glycerine used should be quite free from water, and clear, and should have been standing for a day or two in the precipitating house. The guhr and nitro-glycerine are mixed in lead tanks (about 1-1/2 foot deep, and 2 to 3 feet long), in the proportions of 75 of the nitro-glycerine to 25 of the guhr, unless the guhr is found to be too absorbent, which will cause the dynamite to be too dry and to crumble. In this case a small quantity of barium sulphate, say about 1 per cent., should be added to the guhr. This will lessen its absorbing powers, or a highly absorptive sample of guhr may be mixed with one of less absorptive power, in the proportions found by experiment to be the best suited to make a fairly moist dynamite, but one that will not exude. The mixing itself is generally performed in a separate house. In a series of lead-lined tanks the guhr is weighed, placed in a tank, and the nitro- glycerine poured on to it. The nitro-glycerine may be weighed out in indiarubber buckets. The whole is then mixed by hand, and well rubbed between the hands, and afterwards passed through a sieve. At this stage the dynamite should be dry and powdery, and of a uniform colour. It is now ready to be made up into cartridges, and should be taken over to the cartridge huts. These are small buildings surrounded with mounds, and contain a single cartridge machine. Each hut requires three girls--one to work the press, and two to wrap up the cartridges. The cartridge press consists of a short cylinder of the diameter of the cartridge that it is intended to make. Into this cylinder a piston, pointed with ivory or lignum vitæ wood, works up and down from a spring worked by a lever. Round the upper edge of the cylinder is fastened a canvas bag, into which the powdery dynamite is placed by means of a wooden scoop, and the descending piston forces the dynamite down the cylinder and out of the open end, where the compressed dynamite can be broken off at convenient lengths. The whole machine should be made of gun-metal, and should be upright against the wall of the building. The two girls, who sit at tables placed on each side of the press, wrap the cartridges in parchment paper. From these huts the cartridges are collected by boys every ten minutes or a quarter of an hour, and taken to the packing room, where they are packed in 5-lb. cardboard boxes, which are then further packed in deal boxes lined with indiarubber, and fastened down air tight. The wooden lids are then nailed down with brass or zinc nails, and a label pasted on the outside giving the weight and description of the contents. The boxes should then be removed to the magazines. It is well to take a certain number of cartridges from the packing house at different times during the day, say three or four samples, and to test them by the heat test. A sample cut from a cartridge, about 1 inch long, should be placed under a glass shade, together with water (a large desiccator, in fact), and left for some days. A good dynamite should not, under these conditions, show any signs of exudation, even after weeks.[A] [Footnote A: For analysis of dynamite, see chapter on "Analysis," and author's article in _Chem. News_, 23rd September 1892.] ~Properties of Kieselguhr Dynamite.~--One cubic foot of dynamite weighs 76 lbs. 4 oz. The specific gravity of 75 per cent. dynamite is, however, 1.50. It is a red or grey colour, and rather greasy to the touch. It is much less sensitive to shock than nitro-glycerine, but explodes occasionally with the shock of a rifle bullet, or when struck. The addition of a few per cent. of camphor will considerably diminish its explosive qualities to such an extent that it can be made non-explosive except to a very strong fulminate detonator. The direct contact of water disintegrates dynamite, separating the nitro-glycerine, hence great caution is necessary in using it in wet places. It freezes at about 40° Fahr. (4° C.), and remains frozen at temperatures considerably exceeding that point. When frozen, it is comparatively useless as an explosive agent, and must be thawed with care. This is best done by placing the cartridges in a warming pan, which consists of a tin can, with double sides and bottom, into which hot water (130° Fahr.) can be poured. The dynamite will require to be left in for some considerable time before it becomes soft. On no account must it be placed on a hot stove or near a fire, as many serious accidents have occurred in this way. Frozen dynamite is a hard mass, with altered properties, and requires 1.5 grm. of fulminate instead of 0.5 grm. to explode it. Thawing may also cause exudation of the nitro-glycerine, which is much more sensitive to shock, and if accidentally struck with an iron tool, may explode. It is a dangerous thing to cut a frozen cartridge with a knife. Ramming is even more dangerous; in fact it is not only dangerous, but wasteful, to use dynamite when in a frozen state. Dynamite explodes at a temperature of 360° Fahr., and is very sensitive to friction when hot. In hot countries it should never be exposed to the rays of the sun. It should, however, not be kept in a damp or moist place, as this is liable to cause exudation. Sunlight, if direct, can cause a slow decomposition, as with all nitro and nitric compounds. Electric sparks ignite, without exploding it, at least when operating in the open air. Dynamite, when made with neutral nitro-glycerine, appears to keep indefinitely. Sodium or calcium carbonate to the extent of 1 per cent. is often added to dynamite to ensure its being neutral. If it has commenced to undergo change, however, it rapidly becomes acid, and sometimes explodes spontaneously, especially if contained in resisting envelopes. Nevertheless, neutral and well-made dynamite has been kept for years in a magazine without loss of its explosive force. If water is brought into contact with it, the nitro-glycerine is gradually displaced from the silica (guhr). This action tends to render all wet dynamite dangerous. It has been observed that a dynamite made with wood sawdust can be moistened and then dried without marked alteration, and from 15 to 20 per cent. of water may be added to cellulose dynamite without depriving it of the power of exploding by strong detonator (this is similar to wet gun-cotton). It is, however, rendered much less sensitive to shock. With regard to the power of No. 1 dynamite, experiments made in lead cylinders give the relative value of No. 1 dynamite, 1.0; blasting gelatine, 1.4; and nitro-glycerine, 1.4. The heat liberated by the sudden explosion of dynamite is the same as its heat of combustion,[A] and proportionate to the weight of nitro-glycerine contained in the mixture. The gases formed are carbonic acid, water, nitrogen, and oxygen. [Footnote A: Berthelot, "Explosives and their Power."] The "explosive wave" (of Berthelot) for dynamite is about 5,000 metres per second. At this rate the explosion of a cartridge a foot long would only occupy 1/24000 part of a second, while a ton of dynamite cartridges about 7/8 diameter, laid end to end, and measuring one mile in length, would be exploded in one-quarter of a second by detonating a cartridge at either end.[A] Mr C. Napier Hake, F.I.C., the Inspector of Explosives for the Victorian Government, in his paper, "Notes on Explosives," says: "The theoretical efficiency of an explosive cannot in practice be realised in useful work for several reasons, as for instance in blasting rock-- "1. Incomplete combustion. "2. Compression and chemical changes induced in surrounding material. "3. Energy expended in cracking and heating of the material which is not displaced. "4. The escape of gas through the blast-hole and the fissures caused by the explosion. "The useful work consists partly in displacing the shattered masses. The proportion of useful work obtainable has been variously estimated at from 14 to 33 per cent. of the theoretical maximum potential." [Footnote A: C.N. Hake, "Notes on Explosives," _Jour. Soc. Chem. Ind._, 1889.] Among the various forms of dynamite that are manufactured is carbo- dynamite, the invention of Messrs Walter F. Reid and W.D. Borland. The base is nitro-glycerine, and the absorbent is carbon in the form of burnt cork. It is as cheap as ordinary dynamite, and has greater explosive force, seeing that 90 per cent. of the mixture is pure nitro-glycerine, and the absorbent itself is highly combustible. It is also claimed that if this dynamite becomes wet, no exudation takes place. Atlas powder is a dynamite, chiefly manufactured in America at the Repanno Chemical Works, Philadelphia. It is a composition of nitro-glycerine, wood-pulp, nitrate of soda, and carbonate of magnesia. This was the explosive used in the outrages committed in London, by the so-called "dynamiters." Different varieties contain from 20 to 75 per cent. of nitro-glycerine. The Rhenish dynamite, considerably used in the mines of Cornwall, is composed of 70 parts of a solution of 2 to 3 per cent. of naphthalene in nitro-glycerine, 3 parts of chalk, 7 parts of sulphate of barium, and 20 of kieselguhr. Kieselguhr dynamites are being largely given up in favour of gelatine explosives. The late Colonel Cundill, in his "Dictionary of Explosives," gives a list of about 125 kinds of dynamites. Many of these, however, are not manufactured. Among the best known after the ordinary No. 1 dynamite are forcite, ammonia dynamite, litho-fracteur, rendock, Atlas powder, giant powder, and the various explosive gelatines. They all contain nitro- glycerine, mixed with a variety of other substances, such as absorbent earths, wood-pulp, nitro-cotton, carbon in some form or other, nitro- benzol, paraffin, sulphur, nitrates, or chlorates, &c. &c. ~Blasting Gelatine and Gelatine Dynamite.~--The gelatine explosives chiefly in use are known under the names of blasting gelatine, gelatine dynamite, and gelignite. They all consist of the variety of nitro- cellulose known as collodion-cotton, i.e., a mixture of the penta- and tetra-nitrates dissolved in nitro-glycerine, and made up with various proportions of wood-pulp, and some nitrate, or other material of a similar nature. As the gun-cotton contains too little oxygen for complete combustion, and the nitro-glycerine an excess, a mixture of the two substances is very beneficial. Blasting gelatine consists of collodion-cotton and nitro-glycerine without any other substance, and was patented by Mr Alfred Nobel in 1875. It is a clear, semi-transparent, jelly-like substance, of a specific gravity of 1.5 to 1.55, slightly elastic, resembling indiarubber, and generally consists of 92 per cent. to 93 per cent. of nitro-glycerine, and 7 to 8 per cent. of nitro-cotton. The cotton from which it is made should be of good quality. The following is the analysis of a sample of nitro-cellulose which made very good gelatine:- Soluble cotton 99.118 per cent. Gun-cotton 0.642 " Non-nitrated cotton 0.240 " Nitrogen 11.64 " Total ash 0.25 " The soluble cotton, which is a mixture of the tetra- and penta-nitrates, is soluble in ether-alcohol, and also in nitro-glycerine, and many other solvents, whereas the hexa-nitrate (gun-cotton), C_{12}H_{14}O_{4}(ONO_{2})_{6}, is not soluble in the above liquids, although it is soluble in acetone or acetic ether. It is very essential, therefore, that the nitro-cotton used in the manufacture of the gelatine explosives should be as free as possible from gun-cotton, otherwise little lumps of undissolved nitro-cotton will be left in the finished gelatine. The non-nitrated or unconverted cotton should also be very low, in fact considerably under 1/2 per cent. The nitro-cotton and the nitro-glycerine used should always be tested before use by the heat test, because if they do not separately stand this test, it cannot be expected that the gelatine made from them will do so. It often occurs, however, that although both the ingredients stand this test separately before being mixed, that after the process of manufacture one or other or both fail to do so. The nitro-cotton most suitable for gelatine making is that which has been finely pulped. If it is not already fine enough, it must be passed through a fine brass wire sieve. It will be found that it requires to be rubbed through by hand, and will not go through at all if in the least degree damp. It is better, therefore, to dry it first. The percentage of nitrogen in the nitrated cotton should be over 11 per cent. It should be as free as possible from sand or grit, and should give but little ash upon ignition, not more than 0.25 per cent. The cotton, which is generally packed wet in zinc-lined wooden boxes, will require to be dried, as it is very essential indeed that none of the materials used in the manufacture of gelatine should contain more than the slightest trace of water. If they do, the gelatine subsequently made from them will most certainly exude, and become dangerous and comparatively valueless. It will also be much more difficult to make the nitro-cotton dissolve in the nitro-glycerine if either contains water. In order to find out how long any sample of cotton requires to be dried, a sample should be taken from the centre of several boxes, well mixed, and about 1,000 grms. spread out on a paper tray, weighed, and the whole then placed in the water oven at 100° C., and dried for an hour or so, and again weighed, and the percentage of moisture calculated from the loss in weight. This will be a guide to the time that the cotton will probably require to be in the drying house. Samples generally contain from 20 to 30 per cent. of water. After drying for a period of forty-eight hours, a sample should be again dried in the oven at 100° C., and the moisture determined, and so on at intervals until the bulk of the cotton is found to be dry, i.e., to contain from 0.25 to 0.5 per cent. of moisture. It is then ready to be sifted. During the process of removing to the sifting house and the sifting itself, the cotton should be exposed to the air as little as possible, as dry nitro-cotton absorbs as much as 2 per cent. of moisture from the air at ordinary temperatures and average dryness. The drying house usually consists of a wooden building, the inside of which is fitted with shelves, or rather framework to contain drawers, made of wood, with brass or copper wire netting bottoms. A current of hot air is made to pass through the shelves and over the surface of the cotton, which is spread out upon them to the depth of about 2 inches. This current of air can be obtained in any way that may be found convenient, such as by means of a fan or Root's blower, the air being passed over hot bricks, or hot-water pipes before entering the building. The cotton should also be occasionally turned over by hand in order that a fresh surface may be continually exposed to the action of the hot air. The building itself may be heated by means of hot-water pipes, but on no account should any of the pipes be exposed. They should all be most carefully covered over with wood-work, because when the dry nitro-cotton is moved, as in turning it over, very fine particles get into the air, and gradually settling on the pipes, window ledges, &c., may become very hot, when the slightest friction might cause explosion. It is on this account that this house should be very carefully swept out every day. It is also very desirable that the floor of this house should be covered with oilcloth or linoleum, as being soft, it lessens the friction. List shoes should always be worn in this building, and a thermometer hung up somewhere about the centre of the house, and one should also be kept in one of the trays to give the temperature of the cotton, especially the bottom of the trays. The one nearest to the hot air inlet should be selected. If the temperature of the house is kept at about 40° C. it will be quite high enough. The building must of course be properly ventilated, and it will be found very useful to have the walls made double, and the intervening space filled with cinders, and the roof covered with felt, as this helps to prevent the loss of heat through radiation, and to preserve a uniform temperature, which is very desirable. The dry cotton thus obtained, if not already fine enough, should be sifted through a brass sieve, and packed away ready for use in zinc air-tight cases, or in indiarubber bags. The various gelatine compounds, gelignite, gelatine dynamite, and blasting gelatine, are manufactured in exactly the same way. The forms known as gelatine dynamite differ from blasting gelatine in containing certain proportions of wood-pulp and potassium nitrate, &c. The following are analyses of some typical samples of the three compounds:-- Gelatine Blasting Gelignite. Dynamite. Gelatine. Nitro-glycerine 60.514 71.128 92.94 per cent. Nitro-cellulose 4.888 7.632 7.06 " Wood-pulp 7.178 4.259 ... " Potassium nitrate 27.420 16.720 ... " Water ... 0.261 ... " The gelignite and gelatine dynamites consist, therefore, of blasting gelatine, thickened up with a mixture of absorbing materials. Although the blasting gelatine is weight for weight more powerful, it is more difficult to make than either of the other two compounds, it being somewhat difficult to make it stand the exudation and melting tests. The higher percentage of nitro-cotton, too, makes it expensive. When the dry nitro-cotton, which has been carefully weighed out in the proportions necessary either for blasting gelatine or any of the other gelatine explosives, is brought to the gelatine making house, it is placed in a lead-lined trough, and the necessary quantity of pure dry nitro- glycerine poured upon it. The whole is then well stirred up, and kept at a temperature of from 40° to 45° C. It should not be allowed to go much above 40° C.; but higher temperatures may be used if the nitro-cotton is very obstinate,[A] and will not dissolve. Great caution must, however, be observed in this case. The mixture should be constantly worked about by the workman with a wooden paddle for at least half an hour. At a temperature of 40° to 45° the nitro-glycerine acts upon the nitro-cotton and forms a jelly. Without heat the gelatinisation is very imperfect indeed, and at temperatures under 40° C. takes place very slowly. [Footnote A: Generally due to the nitro-cotton being damp.] [Illustration: FIG. 30.--WERNER, PFLEIDERER, & PERKINS' MIXING MACHINE.] The limit of temperature is 50° C. or thereabouts. Beyond this the jelly should never be allowed to go, and to 50° only under exceptional circumstances. The tank in which the jelly is made is double-lined, in order to allow of the passage of hot water between its inner and outer linings. A series of such tanks are generally built in a wooden framework, and the double linings are made to communicate, so that the hot water can flow from one to the other consecutively. The temperature of the water should be about 60° C. if it is intended to gelatinise at 45° C., and about 80° if at 50° C.; but this point must, of course, be found by experiment for the particular plant used. An arrangement should be made to enable the workman to at once cut off the supply of hot water and pass cold water through the tanks in case the explosive becomes too hot. [Illustration: FIG. 31.--MR M'ROBERTS' MIXER FOR GELATINE EXPLOSIVES.] The best way to keep the temperature of the water constant is to have a large tank of water raised upon a platform, some 5 or 6 feet high, outside the building, which is automatically supplied with water, and into which steam is turned. A thermometer stuck through a piece of cork and floated upon the surface of the tank will give the means of regulating the temperature. When the jelly in the tanks has become semi-transparent and the cotton has entirely dissolved, the mixture should be transferred to the mixing machine. The mixing machines are specially designed for this work, and are built in iron, with steel or bronze kneading- and mixing-blades, according to requirements. A suitable machine for the purpose is that known as the Nito-Universal Incorporator, shown in Fig. 30, which has been specially constructed by Messrs Werner, Pfleiderer, & Perkins, Ltd., after many years' experience in the mixing of explosive materials, and is now almost exclusively adopted in both Government and private factories. Mr George M'Roberts'[A] mixing machine, however, which is shown in Fig. 31, is still used in some factories for dynamite jelly. [Footnote A: See _Jour. Soc. Chem. Ind._, 1890, 267.] If it is intended to make gelignite, or gelatine dynamite, it is at this point that the proper proportions of wood-pulp[A] and potassium nitrate should be added, and the whole well mixed for at least half an hour, until the various ingredients are thoroughly incorporated. [Footnote A: Most of the wood-pulp used in England is obtained from pine-trees, but poplar, lime, birch, and beech wood are also used. It is chiefly imported as wood-pulp. The pulp is prepared as follows:--The bark and roots are first removed, and the logs then sawn into boards, from which the knots are removed. The pieces of wood are afterwards put through a machine which breaks them up into small pieces about an inch long, which are then crushed between rollers. These fragments are finally boiled with a solution of sodium bisulphite, under a pressure of about 90 lbs. per square inch, the duration of the boiling being from ten to twelve hours. Sulphurous acid has also been used. Pine-wood yields about 45 per cent. and birch about 40 per cent. of pulp when treated by this process. The pulp is afterwards bleached and washed, &c. Birch. Beech. Lime. Pine. Poplar. Cellulose 55.52 45.47 53.09 56.99 62.77 per cent. Resin 1.14 0.41 3.93 0.97 1.37 " Aqueous extract 2.65 2.47 3.56 1.26 2.88 " Water 12.48 12.57 10.10 13.87 12.10 " Lignine 28.21 39.14 29.32 26.91 20.88 "] The following analysis of woods is by Dr H. Müller:--These mixing machines can either be turned by hand, or a shaft can be brought into the house and the machine worked by means of a belt at twenty to thirty revolutions per minute. The bearings should be kept constantly greased and examined, and the explosive mixture carefully excluded. When the gelatine mixture has been thoroughly incorporated, and neither particles of nitrate or wood meal can be detected in the mass, it should be transferred to wooden boxes and carried away to the cartridge-making machines to be worked up into cartridges. [Illustration: FIG. 32.--PLAN OF THE BOX CONTAINING THE EXPLOSIVE, IN M'ROBERTS' MACHINE.] The application of heat in the manufacture of the jelly from collodion- cotton and nitro-glycerine is absolutely necessary, unless some other solvent is used besides the nitro-glycerine, such as acetone, acetic ether, methyl, or ethyl-alcohol. (They are all too expensive, with the exception of acetone and methyl-alcohol, for use upon the large scale.) These liquids not only dissolve the nitro-cellulose in the cold, but render the resulting gelatine compound less sensitive to concussion, and reduce its quickness of explosion (as in cordite). They also lower the temperature at which the nitro-glycerine becomes congealed, i.e., they lower the freezing point[A] of the resulting gelatine. [Footnote A: It has been proposed to mix dynamite with amyl alcohol for this purpose. Di-nitro-mono-chlorhydrine has also been proposed.] The finished gelatine paste, upon entering the cartridge huts, is at once transferred to the cartridge-making machine, which is very like an ordinary sausage-making machine[A] (Fig. 33). The whole thing must be made of gun-metal or brass, and it consists of a conical case containing a shaft and screw. The revolutions of the shaft cause the thread of the screw to push forward the gelatine introduced by the hopper on the top to the nozzle, the apex of the cone-shaped case, from whence the gelatine issues as a continuous rope. The nozzle is of course of a diameter according to the size of cartridge required. [Footnote A: G. M'Roberts, _Jour. Soc. Chem. Ind._, 31st March 1890, p. 266.] [Illustration: FIG. 33.--CARTRIDGE-MAKING MACHINE FOR GELATINE EXPLOSIVES.] The issuing gelatine can of course be cut off at any length. This is best done with a piece of hard wood planed down to a cutting edge, i.e., wedge-shaped. Mr Trench has devised a kind of brass frame, into which the gelatine issuing from the nozzle of the cartridge machine is forced, finding its way along a series of grooves. When the frame is full, a wooden frame, which is hinged to one end of the bottom frame, and fitted with a series of brass knives, is shut down, thereby cutting the gelatine up into lengths of about 4 inches. It is essential that the cartridge machines should have no metallic contacts inside. The bearing for the screw shaft must be fixed outside the cone containing the gelatine. One of these machines can convert from 5 to 10 cwt. of gelatine into cartridges per diem, depending upon the diameter of the cartridges made. After being cut up into lengths of about 3 inches, the gelatine is rolled up in cartridge paper. Waterproof paper is generally used. The cartridges are then packed away in cardboard boxes, which are again packed in deal boxes lined with indiarubber, and screwed down air tight, brass screws or zinc or brass nails being used for the purpose. These boxes are sent to the magazines. Before the boxes are fastened down a cartridge or so should be removed and tested by the heat test, the liquefaction test, and the test for liability to exudation. (Appendix, p. 6, Explosives Act, 1875.) A cartridge also should be stored in the magazine in case of any subsequent dispute after the bulk of the material has left the factory. The object of the liquefaction test is to ensure that the gelatine shall be able to withstand a fairly high temperature (such as it might encounter in a ship's hold) without melting or running together. The test is carried out as follows:--A cylinder of the gelatine dynamite is cut from the cartridge of a length equal to its diameter. The edges must be sharp. This cylinder is to be placed on end on a flat surface (such as paper), and secured by a pin through the centre, and exposed for 144 consecutive hours to a temperature of 85° to 90° F., and during such time the cylinder should not diminish in height by more than one-fourth of an inch, and the cut edges should remain sharp. There should also be no stain of nitroglycerine upon the paper. The exudation test consists in freezing and thawing the gelatine three times in succession. Under these conditions there should be no exudation of nitro-glycerine. All the materials used in the manufacture of gelatine explosives should be subjected to analytical examination before use, as success largely depends upon the purity of the raw materials. The wood-pulp, for instance, must be examined for acidity. ~Properties of the Gelatine Compounds.~--Blasting gelatine is generally composed of 93 to 95 parts nitro-glycerine, and 5 to 7 parts of nitro- cellulose, but the relative proportions of explosive base and nitro- glycerine, &c., in the various forms of the gelatine explosives do not always correspond to those necessary for total combustion, either because an incomplete combustion gives rise to a greater volume of gas, or because the rapidity of decomposition and the law of expansion varies according to the relative proportions and the conditions of application. The various additions to blasting gelatine generally have the effect of lowering the strength by reducing the amount of nitro-glycerine, but this is sometimes done in order to change a shattering agent into a propulsive force. If this process be carried too far, we of course lose the advantages due to the presence of nitro-glycerine. There is therefore a limit to these additions.[A] [Footnote A: Mica is said to increase the rapidity of explosion when mixed with gelatine.] The homogeneousness and stability of the mixture are of the highest importance. It is highly essential that the nitro-glycerine should be completely absorbed by the substances with which it is mixed, and that it should not subsequently exude when subjected to heat or damp. It is also important that there should be no excess of nitro-glycerine, as this may diminish instead of augment the strength, owing to a difference in the mode of the propagation of the explosive wave in the liquid, and in the mixture. Nitro-glycerine at its freezing point has a tendency to separate from its absorbing material, in fact to exude. When frozen, too, it requires a more powerful detonation to explode it, but it is less sensitive to shock. The specific gravity of blasting gelatine is 1.5 (i.e., nearly equal to that of nitro-glycerol); that of gun-cotton (dry) is 1.0. Blasting gelatine burns in the air when unconfined without explosion, at least in small quantities and when not previously heated, but it is rather uncertain in this respect. It can be kept at a moderately high temperature (70° C.) without decomposition. At higher temperatures the nitro-glycerine will partially evaporate. When slowly heated, it explodes at 204° C. If, however, it contains as much as 10 per cent. of camphor, it burns without exploding. According to Berthelot,[A] gelatine composed of 91.6 per cent. nitro-glycerine and 8.4 per cent. of nitro-cellulose, which are the proportions corresponding to total combustion, produces by explosion 177CO_{2}+ 143H_{2}O + 8N_{2}. [Footnote A: Berthelot, "Explosives and their Powers."] He takes C_{24}H_{22}(NO_{3}H)_{9}O_{11} as the formula of the nitro- cellulose, and 51C_{3}H_{2}(NO_{3}H)_{3} + C_{24}H_{22}(NO_{3}H)_{9}O_{11} as the formula of the gelatine itself, its equivalent weight being 12,360 grms. The heat liberated by its explosion is equal to 19,381 calories, or for 1 kilo. 1,535 calories. Volume of gases reduced temperature equals 8,950 litres. The relative value[A] of blasting gelatine to nitro- glycerine is as 1.4 to 1.45, kieselguhr dynamite being taken as 1.0. [Footnote A: Roux and Sarran.] CHAPTER V. _NITRO-BENZOL, ROBURITE, BELLITE, PICRIC ACID, &c._ Explosives derived from Benzene--Toluene and Nitro-Benzene--Di- and Tri-nitro-Benzene--Roburite: Properties and Manufacture--Bellite: Properties, &c.--Securite--Tonite No. 3.--Nitro-Toluene-- Nitro-Naphthalene--Ammonite--Sprengel's Explosives--Picric Acid-- Picrates--Picric Powders--Melinite--Abel's Mixture--Brugère's Powders-- The Fulminates--Composition, Formula, Preparation, Danger of, &c.-- Detonators: Sizes, Composition, Manufacture--Fuses, &c. ~The Explosives derived from Benzene.~--There is a large class of explosives made from the nitrated hydro-carbons--benzene, C_{6}H_{6}; toluene, C_{7}H_{8}; naphthalene, C_{10}H_{8}; and also from phenol (or carbolic acid), C_{6}H_{5}OH. The benzene hydro-carbons are generally colourless liquids, insoluble in water, but soluble in alcohol and ether. They generally distil without decomposition. They burn with a smoky flame, and have an ethereal odour. They are easily nitrated and sulphurated; mono, di, and tri derivatives are readily prepared, according to the strength of the acids used. It is only the H-atoms of the benzene nucleus which enter into reaction. Benzene was discovered by Faraday in 1825, and detected in coal-tar by Hofmann in 1845. It can be obtained from that portion of coal-tar which boils at 80° to 85° by fractionating or freezing.[A] The ordinary benzene of commerce contains thiophene (C_{4}H_{4}S), from which it may be freed by shaking with sulphuric acid. Its boiling point is 79° C.; specific gravity at 0° equals 0.9. It burns with a luminous smoky flame, and is a good solvent for fats, resins, sulphur, phosphorus, &c. Toluene was discovered in 1837, and is prepared from coal-tar. It boils at 110° C., and is still liquid at 28° C. [Footnote A: It may be prepared chemically pure by distilling a mixture of benzoic acid and lime.] The mono-, chloro-, bromo-, and iodo-benzenes are colourless liquids of peculiar odour. Di-chloro-, di-bromo-benzenes, tri- and hexa-chloro- and bromo-benzenes, are also known; and mono-chloro-, C_{6}H_{4}Cl(CH_{3}), and bromo-toluenes, together with di derivatives in the ortho, meta, and para modifications. The nitro-benzenes and toluenes are used as explosives. The following summary is taken from Dr A. Bernthsen's "Organic Chemistry":-- SUMMARY. ____________________________________________________________________ | | | C_{6}H_{5}(N0_{2}) Nitro-benzene. Liq. B.Pt. 206° C. | | | | C_{6}H_{4}(NO_{2})_{2} Ortho-, meta-, and para- di-nitro-benzenes. | | Solid. M.P. 118°, 90°, and 172° C. | | | | C_{6}H_{3}(NO_{3})_{3} S.-Tri-nitro-benzene. Solid. M.P. 121° C. | |____________________________________________________________________| | | | C_{6}H_{4}(CH_{3})NO_{2} Ortho-, meta-, and para- nitro-toluenes. | | B.P. 218°, 230°, and 234° C, Para compound solid. | |____________________________________________________________________| | | | C_{6}H_{3}(CH_{3})_{2}NO_{2} Nitro-xylene. Liquid. | |____________________________________________________________________| | | | C_{6}H_{2}(CH_{3})_{3}NO_{2} Nitro-mesitylene. Solid. | |____________________________________________________________________| | | | C_{6}H_{3}(CH_{3})(NO_{2})_{2} Di-nitro-toluenes. | |____________________________________________________________________| | | | C_{6}H_{4}Cl(NO_{2}) Nitro-chloro-benzenes. | | | | C_{6}Br_{4}(NO_{2})_{2} Tetra-bromo-di-nitrobenzene. | |____________________________________________________________________| The nitro compounds are mostly pale yellow liquids, which distil unchanged, and volatilise with water vapour, or colourless or pale yellow needles or prisms. Some of them, however, are of an intense yellow colour. Many of them explode upon being heated. They are heavier than water, and insoluble in it, but mostly soluble in alcohol, ether, and glacial acetic acid. Nitro-benzene, C_{6}H_{5}(NO_{2}), was discovered in 1834 by Mitscherlich. It is a yellow liquid, with a melting point of +3° C. It has an intense odour of bitter almonds. It solidifies in the cold. In di-nitro-benzene, the two nitro groups may be in the meta, ortho, or para position, the meta position being the most general (see fig., page 4). By recrystallising from alcohol, pure meta-di-nitro-benzene may be obtained in long colourless needles. The ortho compound crystallises in tables, and the para in needles. They are both colourless. When toluene is nitrated, the para and ortho are chiefly formed, and a very little of the meta compound. ~Nitro Compounds of Benzene and Toluene.~--The preparation of the nitro derivatives of the hydrocarbons of the benzene series is very simple. It is only necessary to bring the hydrocarbon into contact with strong nitric acid, when the reaction takes place, and one or more of the hydrogen atoms of the hydrocarbon are replaced by the nitryl group (NO_{2}). Thus by the action of nitric acid on benzene (or benzol), mono-nitro-benzene is formed:-- C_{6}H_{6} + HNO_{3} = C_{6}H_{5}.NO_{2} +H_{2}O. Mono-nitro-benzene. By the action of another molecule of nitric acid, the di-nitro-benzene is formed:-- C_{6}H_{5}.NO_{2} + HNO_{3} = C_{6}H_{4}(NO_{2})_{2} + H_{2}O. Di-nitro-benzene. These nitro bodies are not acids, nor are they ethereal salts of nitrous acid, as nitro-glycerine is of glycerine. They are regarded as formed from nitric acid by the replacement of hydroxyl by benzene radicals. ~Mono-nitro Benzene~ is made by treating benzene with concentrated nitric acid, or a mixture of nitric and sulphuric acids. The latter, as in the case of the nitration of glycerine, takes no part in the reaction, but only prevents the dilution of the nitric acid by the water formed in the reaction. Small quantities may be made thus:--Take 150 c.c. of H_{2}SO_{4} and 75 c.c. HNO_{3}, or 1 part nitric to 2 parts sulphuric acid, and put in a beaker standing in cold water; then add 15 to 20 c.c. of benzene, drop by drop, waiting between each addition for the completion of the reaction, and shake well during the operation. When finished, pour contents of beaker into about a litre of cold water; the nitro-benzol will sink to the bottom. Decant the water, and wash the nitro-benzol two or three times in a separating funnel with water. Finally, dry the product by adding a little granulated calcium chloride, and allowing to stand for some little time, it may then be distilled. Nitro-benzene is a heavy oily liquid which boils at 205° C., has a specific gravity of 1.2, and an odour like that of oil of bitter almonds. In the arts it is chiefly used in the preparation of aniline. ~Di-nitro Benzene~ is a product of the further action of nitric acid on benzene or nitro-benzene. It crystallises in long fine needles or thin rhombic plates, and melts at 89.9° C. It can be made thus:--The acid mixture used consists of equal parts of nitric and sulphuric acids, say 50 c.c. of each, and without cooling add very slowly 10 c.c. of benzene from a pipette. After the action is over, boil the mixture for a short time, then pour into about half a litre of water, filter off the crystals thus produced, press between layers of filter paper, and crystallise from alcohol. Di-nitro-benzene, or meta-di-nitro-benzene, as it is sometimes called, enters into the composition of several explosives, such as tonite No. 3, roburite, securite, bellite. Nitro-benzene is manufactured upon the large scale as follows:--Along a bench a row of glass flasks, containing 1 gallon each (1 to 2 lbs. benzene), are placed, and the acids added in small portions at a time, the workmen commencing with the first, and adding a small quantity to each in turn, until the nitration was complete. This process was a dangerous one, and is now obsolete. The first nitro-benzene made commercially in England, by Messrs Simpson, Maule, and Nicholson, of Kennington, in 1856, was by this process. Now, however, vertical iron cylinders, made of cast-iron, are used for the nitrating operation. They are about 4 feet in diameter and 4 feet deep, and a series are generally arranged in a row, at a convenient height from the ground, beneath a line of shafting. Each cylinder is covered with a cast-iron lid having a raised rim all round. A central orifice gives passage to a vertical shaft, and two or more other conveniently arranged openings allow the benzene and the mixed acids to flow in. Each of these openings is surrounded with a deep rim, so that the whole top of the cylinder can be flooded with water some inches in depth, without any of it running into the interior of the nitrator. The lid overhangs the cylinder somewhat, and in the outer rim a number of shot- holes or tubes allow the water to flow down all over the outside of the cylinder into a shallow cast-iron dish, in which it stands. By means of a good supply of cold water, the top, sides, and bottom of the whole apparatus is thus cooled and continually flooded. The agitator consists of cast-iron arms keyed to a vertical shaft, with fixed arms or dash-plates secured to the sides of the cylinder. The shaft has a mitre wheel keyed on the top, which works into a corresponding wheel on the horizontal shafting running along the top of the converters. This latter is secured to a clutch; and there is a feather on the shaft, so that any one of the converters can if necessary be put either in or out of gear. This arrangement is necessary, as riggers or belts of leather, cotton, or indiarubber will not stand the atmosphere of the nitro-benzole house. Above and close to each nitrator stands its acid store tank, of iron or stoneware. The building in which the nitration is carried out should consist of one story, have a light roof, walls of hard brick, and a concrete floor of 9 to 12 inches thick, and covered with pitch, to protect its surface from the action of the acids. The floor should be inclined to a drain, to save any nitro-benzol spilt. Fire hydrants should be placed at convenient places, and it should be possible to at once fill the building with steam. A 2-inch pipe, with a cock outside the building, is advisable. The building should also be as far as possible isolated. The acids are mixed beforehand, and allowed to cool before use. The nitric acid used has a specific gravity of 1.388, and should be as free as possible from the lower oxides of nitrogen. The sulphuric acid has a specific gravity of 1.845, and contains from 95 to 96 per cent. of mono- hydrate. A good mixture is 100 parts of nitric to 140 parts of sulphuric acid, and 78 parts of benzene; or 128 parts HNO_{3}, 179 of H_{2}SO_{4}, and 100 of benzene (C_{6}H_{6}). The benzene having been introduced into the cylinder, the water is turned on and the apparatus cooled, the agitators are set running, and the acid cock turned on so as to allow it to flow in a very thin stream into the nitrator. Should it be necessary to check the machinery even for a moment, the stream of acid must be stopped and the agitation continued for some time, as the action proceeds with such vigour that if the benzene being nitrated comes to rest and acid continues to flow, local heating occurs, and the mixture may inflame. Accidents from this cause have been not infrequent. The operation requires between eight to ten hours, agitation and cooling being kept up all the time. When all the acid is added the water is shut off, and the temperature allowed to rise a little, to about 100° C. When it ceases to rise the agitators are thrown out of gear, and the mixture allowed some hours to cool and settle. The acid is then drawn off, and the nitro-benzene is well washed with water, and sometimes distilled with wet steam, to recover a little unconverted benzene and a trace of paraffin (about .5 per cent. together). At many English works, 100 to 200 gallons, or 800 to 1,760 lbs., are nitrated at a time, and toluene is often used instead of benzene, especially if the nitro-benzene is for use as essence of myrbane. The waste acids, specific gravity 1.6 to 1.7, contain a little nitro-benzene in solution and some oxalic acid. They are concentrated in cast-iron pots and used over again. ~Di-nitro Benzene~ is obtained by treating a charge of the hydrocarbon benzene with double the quantity of mixed acids in two operations, or rather in two stages, the second lot of acid being run in directly after the first. The cooling water is then shut off, and the temperature allowed to rise rapidly, or nitro-benzene already manufactured is taken and again nitrated with acids. A large quantity of acid fumes come off, and some of the nitro- and di-nitro-benzol produced comes off at the high temperature which is attained, and a good condensing apparatus of stoneware must be used to prevent loss. The product is separated from the acids, washed with cold water and then with hot. It is slightly soluble in water, so that the washing waters must be kept and used over again. Finally it is allowed to settle, and run while still warm into iron trays, in which it solidifies in masses 2 or 4 inches thick. It should not contain any nitro-benzol, nor soil a piece of paper when laid on it, should be well crystallised, fairly hard, and almost odourless. The chief product is meta-di-nitro-benzene, melting point 89.8, but ortho-di-nitro-benzene, melting point 118°, and para-di-nitro, melting point 172°, are also produced. The melting point of the commercial product is between 85° to 87° C. Di-nitro-toluene is made in a similar manner. The tri-nitro-benzene can only be made by using a very large excess of the mixed acids. Nitro- benzene, when reduced with iron, zinc, or tin, and hydrochloric acids, forms aniline. ~Roburite.~--This explosive is the invention of a German chemist, Dr Carl Roth (English patent 267A, 1887), and is now manufactured in England, at Gathurst, near Wigan. It consists of two component parts, non-explosive in themselves (Sprengel's principle), but which, when mixed, form a powerful explosive. The two substances are ammonium nitrate and chlorinated di-nitro-benzol. Nitro-naphthalene is also used. Nitrate of soda and sulphate of ammonium are allowed to be mixed with it. The advantages claimed for the introduction of chlorine into the nitro compound are that chlorine exerts a loosening effect upon the NO_{2} groups, and enables the compound to burn more rapidly than when the nitro groups alone are present. The formula of chloro-di-nitro-benzol is C_{6}H_{3}Cl(NO_{2})_{2}. The theoretical percentage of nitrogen, therefore, is 13.82, and of chlorine 17.53. Dr Roth states that, from experiments he has made, the dynamic effect is considerably increased by the introduction of chlorine into the nitro compound. Roburite burns quickly, and is not sensitive to shock; it must be used dry; it cannot be made to explode by concussion, pressure, friction, fire, or lightning; it does not freeze; it does not give off deleterious fumes, and it is to all intents and purposes flameless; and when properly tamped and fired by electricity, can be safely used in fiery mines, neither fine dust nor gases being ignited by it. The action is rending and not pulverising. Compared to gunpowder, it is more powerful in a ratio ranging from 2-1/2 to 4 to 1, according to the substance acted upon. It is largely used in blasting, pit sinking, quarrying, &c., but especially in coal mining. According to Dr Roth, the following is the equation of its decomposition:-- C_{6}H_{3}Cl(NO_{2})_{2} + 9HN_{4}NO_{3} = 6CO_{2} + 20N + HCl. In appearance roburite is a brownish yellow powder, with the characteristic smell of nitro-benzol. Its specific gravity is 1.40. The Company's statement that the fumes of roburite were harmless having been questioned by the miners of the Garswood Coal and Iron Works Colliery, a scientific committee was appointed by the management and the men jointly for the purpose of settling the question. The members of this committee were Dr N. Hannah, Dr D.J. Mouncey, and Professor H.B. Dixon, F.R.S., of Owens College. After a protracted investigation, a long and technical report was issued, completely vindicating the innocuousness of roburite when properly used. In the words of _The Iron and Coal Trades' Review_ (May 24, 1889), "The verdict, though not on every point in favour of the use in all circumstances of roburite in coal mines, is yet of so pronounced a character in its favour as an explosive that it is impossible to resist the conclusion that the claims put forward on its behalf rest on solid grounds." Roburite was also one of the explosives investigated by the committee appointed in September 1889 by the Durham Coalowners' and Miners' Associations, for the purpose of determining whether the fumes produced by certain explosives are injurious to health. Both owners and workmen were represented on the committee, which elected Mr T. Bell, H.M. Inspector of Mines, as its chairman, with Professor P.P. Bedson and Drs Drummond and Hume as professional advisers. The problem considered was whether the fumes produced by the combustion of certain explosives, one of which was roburite, were injurious to health. The trial comprised the chemical analysis of the air at the "intake," and of the vitiated air during the firing of the shots at the "return," and also of the smoky air in the vicinity of the shot-holes. Five pounds and a half of roburite were used in twenty-three shots. It had been asserted that the fumes from this explosive contained carbon-monoxide, CO, but no trace of this gas could be discovered after the explosion. On another occasion, however, when 4.7 lbs. of roburite were exploded in twenty-three shots, the air at the "return" showed traces of CO gas to the extent of .042 to .019 per cent. The medical report which Drs Hume and Drummond presented to the committee shows that they investigated every case of suspected illness produced by exposure to fumes, and they could find no evidence of acute illness being caused. They say, "No case of acute illness has, throughout the inquiry, been brought to our knowledge, and we are led to the conclusion that such cases have not occurred." ~Manufacture.~--As now made, roburite is a mixture of ammonium nitrate and chlorinated di-nitro-benzol. The nitrate of ammonia is first dried and ground, and then heated in a closed steam-jacketed vessel to a temperature of 80° C., and the melted organic compound is added, and the whole stirred until an intimate mixture is obtained. On cooling, the yellow powder is ready for use, and is stored in straight canisters or made up into cartridges. Owing to the deliquescent nature of the nitrate of ammonia, the finished explosive must be kept out of contact with the air, and for this reason the cartridges are waterproofed by dipping them in melted wax. Roburite is made in Germany, at Witten, Westphalia; and also at the English Company's extensive works at Gathurst, near Wigan, which have been at work now for some eighteen years, having started in 1888. These works are of considerable extent, covering 30 acres of ground, and are equal to an output of 10 tons a day. A canal runs through the centre, separating the chemical from the explosive portions of the works, and the Lancashire and Yorkshire Railway runs up to the doors. Besides sending large quantities of roburite itself abroad, the Company also export to the various colonies the two components, as manufactured in the chemical works, and which separately are quite non-explosive, and which, having arrived at their destination, can be easily mixed in the proper proportions. Among the special advantages claimed for roburite are:--First, that it is impossible to explode a cartridge by percussion, fire, or electric sparks. If a cartridge or layer be struck with a heavy hammer, the portion struck is decomposed, owing to the large amount of heat developed by the blow. The remaining explosive is not in the least affected, and no detonation whatever takes place. If roburite be mixed with gunpowder, and the gunpowder fired, the explosion simply scatters the roburite without affecting it in the least. In fact, the only way to explode roburite is to detonate it by means of a cap of fulminate, containing at least 1 gramme of fulminate of mercury. Secondly, its great safety for use in coal mines. Roburite has the great advantage of exploding by detonation at a very low temperature, indeed so low that a very slight amount of tamping is required when fired in the most explosive mixture of air and coal gas possible, and not at all in a mixture of air and coal dust--a condition in which the use of gunpowder is highly dangerous. Mr W.J. Orsman, F.I.C., in a paper read at the University College, Nottingham, in 1893, gives the temperature of detonation of roburite as below 2,100° C., and of ammonium nitrate as 1,130° C., whereas that of blasting gelatine is as much as 3,220° C. With regard to the composition of the fumes formed by the explosion of roburite, Mr Orsman says: "With certain safety explosives--roburite, for instance--an excess of the oxidising material is added, namely, nitrate of ammonia; but in this case the excess of oxygen here causes a diminution of temperature, as the nitrate of ammonia on being decomposed absorbs heat. This excess of oxygen effectually prevents the formation of carbon monoxide (CO) and the oxides of nitrogen." The following table (A), also from Mr Orsman's paper, gives the composition of five prominent explosives, and shows the composition of the gases formed on explosion. The gases were collected after detonating 10 grms. of each in a closed strong steel cylinder, having an internal diameter of 5 inches. With respect to the influence of ammonium nitrate in lowering the temperature of explosion of the various substances to which it is added, it was found by a French Commission that, when dry and finely powdered, ammonium nitrate succeeds in depreciating the heat of decomposition without reducing the power of the explosive below a useful limit. The following table (B) shows the composition of the explosives examined, and the temperatures which accompanied their explosion. A ______________________________________________________________________ | | | | | | | Composition of Gases. | | |Volume |__________________________| | Explosive. |of Gas | | | | | | |formed.|CO_{2}.| CO. |CH_{4}| N. | | | | | | &H. | | |___________________________________|_______|_______|_____|______|_____| | | | | | | | | | | Per | Per | Per | Per | | | c.c. | cent. |cent.|cent. |cent.| |Gunpowder-- | | | | | | | Nitre 75 parts | | | | | | | Sulphur 10 '' | 2,214 | 51.3 | 3.5| 3.5 | 41.7| | Charcoal 15 '' | | | | | | |Gelignite-- | | | | | | | Nitro-glycerine 56.5 parts | | | | | | | Nitro-cotton 3.5 '' | 4,980 | 25 | 7 | ... | 67 | | Wood-meal 8.0 '' | | | | | | | KNO_{3} 32.0 '' | | | | | | |Tonite-- | | | | | | | Nitro-Cotton | 3,750 | 30 | 8 | ... | 62 | | Barium nitrate | | | | | | |Roburite-- | | | | | | | Ammonium nitrate, 86 parts | | | | | | | Di-nitro-chloro-benzol 14 '' | 4,780 | 32 | ... | ... | 68 | |Carbonite | | | | | | | Nitro-glycerine 25 parts | | | | | | | Wood-meal 40 '' | 2,100 | 19 | 15 | 26 | ... | | Potas. nitrate 34 '' | | | | | | |___________________________________|_______|_______|_____|______|_____| B ____________________________________________________________________ | | | | | | | Original | Percentage | Final | | Explosive. | Temperature |NH_{4}.NO_{3}| Temperature | | |Co-efficient.| added. |Co-efficient.| |__________________________|_____________|_____________|_____________| | | | | | |Nitro-glycerine | 3,200 | ... | ... | |Blasting gelatine | | | | | (8 per cent. gun-cotton)| 3,090 | 88 | 1,493 | |Dynamite | | | | | (25 per cent. silica)| 2,940 | 80 | 1,468 | | | | | | |Gun-cotton, 1 | 2,650 | ... | ... | | | 2,060 | 90.5 | 1,450 | | | | | | |Ammonium nitrate | 1,130 | ... | ... | |__________________________|_____________|_____________|_____________| ~Bellite~ is the patent of Mr Carl Lamm, Managing Director of the Rötebro Explosive Company, of Stockholm, and is licensed for manufacture in England. It consists of a mixture of nitrate of ammonia with di- or tri-nitro-benzol, it has a specific gravity of 1.2 to 1.4 in its granulated state, and 1 litre weighs 800 to 875 grms. Heated in an open vessel, bellite loses its consistency at 90° C., but does not commence to separate before a temperature of 200° C. is reached, when it evaporates without exploding. If heated suddenly, it burns with a sooty flame, somewhat like tar, but if the source of heat is removed, it will cease burning, and assume a caramel-like structure. It absorbs very little moisture from the air after it has been pressed, and if the operation has been performed while the explosive is hot, the subsequent increase of weight is only 2 per cent. When subjected to the most powerful blow with a steel hammer upon an iron plate, it neither explodes nor ignites. A rifle bullet fired into it at 50 yards' distance will not explode it. Granulated bellite explodes fully by the aid of fulminating mercury. Fifteen grms. of bellite fired by means of fulminate, projected a shot from an ordinary mortar, weighing 90 lbs., a distance of 75 yards, 15 grms. of gunpowder, under the same conditions, throwing it only 12 yards. A weight of 7-1/2 lbs. falling 145 centimetres failed to explode 1 grm. of bellite. Various experiments and trials have been made with this explosive by Professor P.T. Cleve, M.P.F. Chalon, C.N. Hake, and by a committee of officers of the Swedish Royal Artillery. It is claimed that it is a very powerful and extremely safe explosive; that it cannot be made to explode by friction, shock, or pressure, nor by electricity, fire, lightning, &c., and that it is specially adapted for use in coal mines, &c.; that it can only be exploded by means of a fulminate detonator, and is perfectly safe to handle and manufacture; that it does not freeze, can be used as a filling for shells, and lastly, can be cheaply manufactured. ~Securite~ consists of 26 parts of meta-di-nitro-benzol and 74 parts of ammonium nitrate. It is a yellow powder, with an odour of nitro-benzol. It was licensed in 1886. It sometimes contains tri-nitro-benzol, and tri-nitro-naphthalene. The equation of its combustion is given as C_{6}H_{4}(NO_{2})_{2} + 10(NH_{4}NO_{3}) = 6CO_{2} + 22H_{2}O + 11N_{2} and, like bellite and roburite, it is claimed to be perfectly safe to use in the presence of fire damp and coal dust.[A] The variety known as Flameless Securite consists of a mixture of nitrate and oxalate of ammonia and di-nitro-benzol. [Footnote A: See paper by S.B. Coxon, _North of Eng. Inst. Mining and Mech. Eng._, 11, 2, 87.] ~Kinetite.~--A few years ago an explosive called "Kinetite"[A] was introduced, but is not manufactured in England. It was the patent of Messrs Petry and Fallenstein, and consisted of nitro-benzol, thickened or gelatinised by the addition of some collodion-cotton, incorporated with finely ground chlorate of potash and precipitated sulphide of antimony. An analysis gave the following percentages:-- Nitro-benzol, 19.4 per cent. Chlorate of potash, 76.9 per cent. Sulphide of antimony nitro-cotton, 3.7 per cent. [Footnote A: V. Watson Smith, _Jour. Soc. Chem. Ind._, January 1887.] It requires a very high temperature to ignite it, and cannot, under ordinary circumstances, when unconfined, be exploded by the application of heat. It is little affected by immersion in water, unless prolonged, when the chlorate dissolves out, leaving a practical inexplosive residue.[A] It was found to be very sensitive to combined friction and percussion, and to be readily ignited by a glancing blow of wood upon wood. It was also deficient in chemical stability, and has been known to ignite spontaneously both in the laboratory and in a magazine. It is an orange- coloured plastic mass, and smells of nitro-benzol. [Footnote A: Col. Cundill, R.A., "Dict. of Explosives," says: "If, however, it be exposed to moist and dry air alternately, the chlorate crystallises out on the surfaces, and renders the explosive very sensitive."] ~Tonite No. 3~ contains 10 to 14 per cent. of nitro-benzol (see Tonite). Trench's Flameless Explosive contains 10 per cent. of di-nitro-benzol, together with 85 per cent. of nitrate of ammonia, and 5 per cent. of a mixture of alum, and the chlorides of sodium and ammonia. ~Tri-nitro-Toluene.~--Toluene, C_{7}H_{8}, now chiefly obtained from coal- tar, was formerly obtained by the dry distillation of tolu-balsam. It may be regarded as methyl-benzene, or benzene in which one hydrogen is replaced by methyl (CH_{3}), thus (C_{6}H_{5}CH_{3}), or as phenyl- methane, or methane in which one hydrogen atom is replaced by the radical phenyl (C_{6}H_{5}), thus (CH_{3}C_{6}H_{5}). Toluene is a colourless liquid, boiling at 110° C., has a specific gravity of .8824 at 0° C., and an aromatic odour. Tri-nitro-toluene is formed by the action of nitric acid on toluene. According to Häussermann, it is more advantageous to start with the ortho-para-di-nitro-toluene, which is prepared by allowing a mixture of 75 parts of 91 to 92 per cent. nitric acid and 150 parts of 95 to 96 per cent. sulphuric acid to run in a thin stream into 100 parts of para-nitro-toluene, while the latter is kept at a temperature between 60° to 65° C., and continually stirred. When the acid has all been run in, this mixture is heated for half an hour to 80° C., and allowed to stand till cold. The excess of nitric acid is then removed. The residue after this treatment is a homogeneous crystalline mass of ortho-para-di-nitro- toluene, of which the solidifying point is 69.5° C. To convert this mass into tri-nitro derivative, it is dissolved by gently heating it with four times its weight of sulphuric acid (95 to 96 per cent.), and it is then mixed with 1-1/2 times its weight of nitric acid (90 to 92 per cent.), the mixture being kept cool. Afterwards it is digested at 90° to 95° C., with occasional stirring, until the evolution of gas ceases. This takes place in about four or five hours. The operation is now stopped, the product allowed to cool, and the excess of nitric acid separated from it. The residue is then washed with hot water and very dilute soda solution, and allowed to solidify without purification. The solidifying point is 70° C., and the mass is then white, with a radiating crystalline structure. Bright sparkling crystals, melting at 81.5° C. may, however, be obtained by recrystallisation from hot alcohol. The yield is from 100 parts di-nitro-toluene, 150 parts of the tri-nitro derivative. Häussermann states also that 1:2:4:6 tri-nitro- toluene can be obtained from ordinary commercial di-nitro-toluene melting at 60° to 64° C.; but when this is used, greater precautions must be exercised, for the reactions are more violent. Moreover, 10 per cent. more nitric acid is required, and the yield is 10 per cent. less. He also draws attention to the slight solubility of tri-nitro-toluene in hot water, and to the fact that it is decomposed by dilute alkalies and alkaline carbonates--facts which must be borne in mind in washing the substance. This material is neither difficult nor dangerous to make. It behaves as a very stable substance when exposed to the air under varying conditions of temperature (-10° to +50° C.) for several months. It cannot be exploded by flame, nor by heating it in an open vessel. It is only slightly decomposed by strong percussion on an anvil. A fulminate detonator produces the best explosive effect with tri-nitro-toluene. It can be used in conjunction with ammonium nitrate, but such admixture weakens the explosive power; but even then it is stated to be stronger than an equivalent mixture of di-nitro-benzene and ammonium nitrate. Mowbray patented a mixture of 3 parts nitro-toluol to 7 of nitro-glycerine, also in the proportions of 1 to 3, which he states to be a very safe explosive. ~Faversham Powder.~--One of the explosives on the permitted list (coal mines) is extensively used, and is manufactured by the Cotton Powder Co. Ltd. at Faversham. It is composed of tri-nitro-toluol 11 parts, ammonium nitrate 93 parts, and moisture 1 part. This explosive must be used only when contained in a case of an alloy of lead, tin, zinc, and antimony thoroughly waterproof; it must be used only with a detonator or electric detonator of not less strength than that known as No. 6. ~Nitro-Naphthalene.~--Nitro-naphthalene is formed by the action of nitric acid on naphthalene (C_{10}H_{8}). Its formula is C_{10}H_{7}NO_{2}, and it forms yellow needles, melting at 61° C.; and of di-nitro-naphthalene (C_{10}H_{6}(NO_{2})_{2}), melting point 216° C. There are also tri-nitro and tetra-nitro and [alpha] and [beta] derivatives of nitro-naphthalene. It is the di-nitro-naphthalene that is chiefly used in explosives. It is contained in roburite, securite, romit, Volney's powder, &c. Fehven has patented an explosive consisting of 10 parts of nitro-naphthalene mixed with the crude ingredients of gunpowder as follows:--Nitro-naphthalene, 10 parts; saltpetre, 75 parts; charcoal, 12.5 parts; and sulphur, 12.5 parts. He states that he obtains a mono-nitro-naphthalene, containing a small proportion of di-nitro-naphthalene, by digesting 1 part of naphthalene, with or without heat, in 4 parts of nitric acid (specific gravity 1.40) for five days. Quite lately a patent has been taken out for a mixture of nitro- naphthalene or di-nitro-benzene with ammonium nitrate, and consists in using a solvent for one or other or both of the ingredients, effected in a wet state, and then evaporating off the solvent, care being taken not to melt the hydrocarbon. In this way a more intimate mixture is ensured between the particles of the components, and the explosive thus prepared can be fired by a small detonator, viz., by 0.54 grms. of fulminate. Favier's explosive also contains mono-nitro-naphthalene (8.5 parts), together with 91.5 parts of nitrate of ammonia. This explosive is made in England by the Miners' Safety Explosive Co. A variety of roburite contains chloro-nitro-naphthalene. Romit consists of 100 parts ammonium nitrate and 7 parts potassium chlorate mixed with a solution of 1 part nitro- naphthalene and 2 parts rectified paraffin oil. ~Ammonite.~--This explosive was originally made at Vilvorde in Belgium, under the title of the Favier Explosive, consisting of a compressed hollow cylinder composed of 91.5 per cent. of nitrate of ammonia, and 8.5 per cent. of mono-nitro-naphthalene filled inside with loose powder of the same composition. The cartridges were wrapped in paper saturated with paraffin-wax, and afterwards dipped in hot paraffin to secure their being water-tight. The Miners' Safety Explosives Co., when making this explosive at their factory at Stanford-le-Hope, Essex, abandoned after a short trial the above composition, and substituted di-nitro-naphthalene 11.5 per cent. for the mono-nitro-naphthalene, and used thin lead envelopes filled with loose powder slightly pressed in, in place of the compressed cylinders containing loose powder. The process of manufacture is shortly as follows:--132-3/4 lbs. of thoroughly dried nitrate of ammonium is placed in a mill pan, heated at the bottom with live steam, and ground for about twenty minutes until it becomes so dry that a slight dust follows the rollers; then 17-1/2 lbs. of thoroughly dry di-nitro-naphthalene is added, and the grinding continued for about ten minutes. Cold water is then circulated through the bottom of the pan until the material appears of a lightish colour and falls to powder. (While the pan is hot the whole mass looks slightly plastic and of a darker colour than when cold.) A slide in the bottom of the pan is then withdrawn, the whole mass working out until the pan is empty; it is now removed to the sifting machine, brushed through a wire sieve of about 12 holes to the inch, and is then ready for filling into cartridges. The hard core is returned from the sifting machine and turned into one of the pans a few minutes before the charge is withdrawn. The ammonite is filled into the metallic cartridges by means of an archimedian screw working through a brass tube, pushing off the cartridges as the explosive is fed into them against a slight back pressure; a cover is screwed on, and they then go to the dipping room, where they are dipped in hot wax to seal the ends; they are then packed in boxes of 5 lbs. each and are ready for delivery. The di-nitro-naphthalene is made at the factory. Mono-nitro-naphthalene is first made as follows:--12 parts of commercial nitrate of soda are ground to a fine powder, and further ground with the addition of 15 parts of refined naphthalene until thoroughly incorporated; it is then placed in an earthenware pan, and 30 parts of sulphuric acid of 66° B. added, 2 parts at a time, during forty-eight hours (the rate of adding H_{2}SO_{4} depends on the condition of the charge, and keeping it in a fluid state), with frequent agitation, day and night, during the first three or four days, afterwards three or four times a day. In all fourteen days are occupied in the nitration process. It is then strained through an earthenware strainer, washed with warm water, drained, and dried. For the purpose of producing this material in a granulated condition, which is found more convenient for drying, and further nitrification, it is placed in a tub, and live steam passed through, until brought up to the boiling point (the tub should be about half full), cold water is then run in whilst violently agitating the contents until the naphthalene solidifies; it can then be easily drained and dried. For the further treatment to make di-nitro-naphthalene, 18 parts of nitro-naphthalene are placed in an earthenware pan, together with 39 parts of sulphuric acid of 66° B., then 15 parts of nitric acid of 40° B. are added, in small quantities at a time, stirring the mixture continually. This adding of nitric acid is controlled by the fuming, which should be kept down as much as possible. The operation takes ten to twelve days, when 100 times the above quantities, taken in kilogrammes, are taken. At the end of the nitration the di-nitro-naphthalene is removed to earthenware strainers, allowed to drain, washed with hot water and soda until all acid is removed, washed with water and dried. The di-nitro- naphthalene gives some trouble in washing, as some acid is held in the crystals which is liable to make its appearance when crushed. To avoid this it should be ground and washed with carbonate of soda before drying; an excess of carbonate of soda should not, however, be used. ~Electronite.~--This is a high explosive designed to afford safety in coal getting. This important end has been attained by using such ingredients, and so proportioning them, as will ensure on detonation a degree of heat insufficient under the conditions of a "blown-out" shot, to ignite fire damp or coal dust. It is of the nitrate of ammonium class of permitted explosives. It contains about 75 per cent. of nitrate of ammonium, with the addition of nitrate of barium, wood meal, and starch. The gases resulting from detonation are chiefly water in the gaseous form, nitrogen, and a little carbon dioxide. It is granulated with the object of preventing missfires from ramming, to which nitrate of ammonium explosives are somewhat susceptible. This explosive underwent some exhaustive experiments at the experimental station near Wigan in 1895, when 8 oz. or 12 oz. charges were fired unstemmed into an admixture of coal dust and 10 per cent. of gas, without any ignition taking place. It is manufactured by Messrs Curtis's & Harvey Ltd. at their factory, Tonbridge, Kent. ~Sprengel's Explosives.~--This is a large class of explosives. The essential principle of them all is the admixture of an oxidising with a combustible agent at the time of, or just before, being required for use, the constituents of the mixture being very often non-explosive bodies. This type of explosive is due to the late Dr Herman Sprengel, F.R.S. Following up the idea that an explosion is a sudden combustion, he submitted a variety of mixtures of oxidising and combustible agents to the violent shock of a detonator of fulminate. These mixtures were made in such proportions that the mutual oxidation or de-oxidation should be theoretically complete. Among them are the following:-- 1. One chemical equivalent of nitro-benzene to equivalents of nitric acid. 2. Five equivalents of picric acid to 13 equivalents of nitric acid. 3. Eighty-seven equivalents of nitro-naphthalene to 413 equivalents of nitric acid. 4. Porous cakes, or lumps of chlorate of potash, exploded violently with bisulphide of carbon, nitro-benzol, carbonic acid, sulphur, benzene, and mixtures of these substances. No. 1 covers the explosive known as _Hellhoffite_, and No. 2 is really oxonite, and No. 4 resembles rack-a-rock, an explosive invented by Mr S.R. Divine, and consisting of a mixture of chlorate of potash and nitro- benzol. Roburite, bellite, and securite should perhaps be regarded as belonging to the Sprengel class of explosives, otherwise this class is not manufactured or used in England. The principal members are known as _Hellhoffite_, consisting of a mixture of nitro-petroleum or nitro-tar oils and nitric acid, or of meta-di-nitro-benzol and nitric acid; _Oxonite_, consisting of picric and nitric acids; and _Panclastite_, a name given to various mixtures, proposed by M. Turpin, such as liquid nitric peroxide, with bisulphide of carbon, benzol, petroleum, ether, or mineral oils. ~Picric Acid, Tri-nitro-Phenol, or Carbazotic Acid.~--Picric acid, or a tri-nitro-phenol (C_{6}H_{2}(NO_{2})_{3}OH)[2:4:6], is produced by the action of nitric acid on many organic substances, such as phenol, indigo, wool, aniline, resins, &c. At one time a yellow gum from Botany Bay (_Xanthorrhoea hastilis_) was chiefly used. One part of phenol (carbolic acid), C_{6}H_{5}OH, is added to 3 parts of strong fuming nitric acid, slightly warmed, and when the violence of the reaction has subsided, boiled till nitrous fumes are no longer evolved. The resinous mass thus produced is boiled with water, the resulting picric acid is converted into a sodium salt by a solution of sodium carbonate, which throws down sodium picrate in crystals. Phenol-sulphuric acid is now, however, more generally used, and the apparatus employed for producing it closely resembles that used in making nitro-benzol. It is also made commercially by melting carbolic acid, and mixing it with strong sulphuric acid, then diluting the "sulpho- carbolic"[A] acid with water, and afterwards running it slowly into a stone tank containing nitric acid. This is allowed to cool, where the crude picric acid crystallises out, and the acid liquid (which contains practically no picric acid, but only sulphuric acid, with some nitric acid) being poured down the drains. The crude picric acid is then dissolved in water by the aid of steam, and allowed to cool when most of the picric acid recrystallises. The mother liquor is transferred to a tank and treated with sulphuric acid, when a further crop of picric acid crystals is obtained. The crystals of picric acid are further purified by recrystallisation, drained, and dried at 100° F. on glazed earthenware trays by the aid of steam. It can also be obtained by the action of nitric acid on ortho-nitro-phenol, para-nitro-phenol, and di-nitro-phenol (2:4 and 2:6), but not from meta-nitro-phenol, a fact which indicates its constitution.[B] [Footnote A: O. and p. phenolsulphonic acids. C_{3}H_{4}(OH).SO_{3}H + 3HNO_{3} = C_{6}H_{2}(NO_{2})_{3}OH + H_{2}SO_{4} + 2H_{2}O. (Picric acid).] [Footnote B: Carey Lea, _Amer. Jour. Sci._, (ii.), xxxii. 180.] Picric acid crystallises in yellow shining prisms or laminæ having an intensely bitter taste, and is poisonous. It melts at 122.5° C., sublimes when cautiously heated, dissolves sparingly in cold water, more easily in hot water, still more in alcohol. It stains the skin an intense yellow colour, and is used as a dye for wool and silk. It is a strong acid, forming well crystallised yellow salts, which detonate violently when heated, some of them also by percussion. The potassium salt, C_{6}H_{2}(NO_{2})_{3}OK, crystallises in long needles very slightly soluble in water. The sodium, ammonium, and barium salts are, however, easily soluble in water. Picric acid, when heated, burns with a luminous and smoky flame, and may be burnt away in large quantity without explosion; but the mere contact of certain metallic oxides, with picric acid, in the presence of heat, develops powerful explosives, which are capable of acting as detonators to an indefinite amount of the acid, wet or dry, which is within reach of their detonative influence. The formula of picric acid is C_{6}H_{2}|(NO_{2})_{3} |OH. which shows its formation from phenol (C_{6}H_{5}OH.), three hydrogen atoms being displaced by the NO_{2} group. The equation of its formation from phenol is as follows:-- C_{6}H_{5}.OH + 3HNO_{3} = C_{6}H_{2}(NO_{2})_{3}OH + 3H_{2}O. According to Berthelot, its heat of formation from its elements equals 49.1 calories, and its heat of total combustion by free oxygen is equal to +618.4 cals. It hardly contains more than half the oxygen necessary for its complete combustion. 2C_{6}H_{2}(NO_{2})_{3}OH + O_{10} = 12CO_{2} + 3H_{2} + 3N_{2}. The percentage composition of picric acid is--Nitrogen, 18.34; oxygen, 49.22; hydrogen, 1.00; and carbon, 31.44, equal to 60.26 per cent. of NO_{2}. The products of decomposition are carbonic acid, carbonic oxide, carbon, hydrogen, and nitrogen, and the heat liberated, according to Berthelot, would be 130.6 cals., or 570 cals. per kilogramme. The reduced volume of the gases would be 190 litres per equivalent, or 829 litres per kilogramme. To obtain a total combustion of picric acid it is necessary to mix with it an oxidising agent, such as a nitrate, chlorate, &c. It has been proposed to mix picric acid (10 parts) with sodium nitrate (10 parts) and potassium bichromate (8.3 parts). These proportions would furnish a third of oxygen in excess of the necessary proportion. Picric acid was not considered to be an explosive, properly so called, for a long time after its discovery, but the disastrous accident which occurred at Manchester (_vide_ Gov. Rep. No. LXXXI., by Colonel (now Sir V.D.) Majendie, C.B.), and some experiments made by Dr Duprè and Colonel Majendie to ascertain the cause of the accident, conclusively proved that this view was wrong. The experiments of Berthelot (_Bull. de la Soc. Chim. de Paris_, xlix., p. 456) on the explosive decomposition of picric acid are also deserving of attention in this connection. If a small quantity of picric acid be heated in a moderate fire, in a crucible, or even in an open test tube, it will melt (at 120° C. commercial acid), then give off vapours which catch fire upon contact with air, and burn with a sooty flame, without exploding. If the burning liquid be poured out upon a cold slab, it will soon go out. A small quantity carefully heated in a tube, closed at one end, can even be completely volatilised without apparent decomposition. It is thus obvious that picric acid is much less explosive than the nitric ethers, such as nitro-glycerol and nitro-cellulose, and very considerably less explosive than the nitrogen compounds and fulminates. It would, however, be quite erroneous to assume that picric acid cannot explode when simply heated. On the contrary, Berthelot has proved that this is not the case. If a glass tube be heated to redness, and a minute quantity of picric acid crystals be then thrown in, it will explode with a curious characteristic noise. If the quantity be increased so that the temperature of the tube is materially reduced, no explosion will take place at once, but the substance will volatilise and then explode, though with much less violence than before, in the upper part of the tube. Finally, if the amount of picric acid be still further increased under these conditions, it will undergo partial decomposition and volatilise, but will not even deflagrate. Nitro-benzene, di-nitrobenzene, and mono-, di-, and tri-nitro-naphthalenes behave similarly. The manner in which picric acid will decompose is thus dependent upon the initial temperature of the decomposition, and if the surrounding material absorb heat as fast as it is produced by the decomposition, there will be no explosion and no deflagration. If, however, the absorption is not sufficient to prevent deflagration, this may so increase the temperature of the surrounding materials that the deflagration will then end in explosion. Thus, if an explosion were started in an isolated spot, it would extend throughout the mass, and give rise to a general explosion. In the manufacture of picric acid the first obvious and most necessary precaution is to isolate the substance from other chemicals with which it might accidentally come into contact. If pure materials only are used, the manufacture presents no danger. The finished material, however, must be carefully kept from contact with nitrates, chlorates, or oxides. If only a little bit of lime or plaster become accidentally mixed with it, it may become highly dangerous. A local explosion may occur which might have the effect of causing the explosion of the whole mass. Picric acid can be fired by a detonator, 5-grain fulminate, and M. Turpin patented the use of picric acid, unmixed with any other substance, in 1885. The detonation of a small quantity of dry picric acid is sufficient to detonate a much larger quantity containing as much as 17 per cent. of water. It is chiefly due to French chemists (and to Dr Sprengel) that picric acid has come to the front as an explosive. Melinite,[A] a substance used by the French Government for filling shells, was due to M. Turpin, and is supposed to be little else than fused picric acid mixed with gun-cotton dissolved in some solvent (acetone or ether-alcohol). Sir F.A. Abel has also proposed to use picric acid, mixed with nitrate of potash (3 parts) and picrate of ammonia (2 parts) as a filling for shells. This substance requires a violent blow and strong confinement to explode it. I am not aware, however, that it has ever been officially adopted in this country. Messrs Désignolles and Brugère have introduced military powders, consisting of mixtures of potassium and ammonium picrates with nitrate of potassium. M. Désignolles introduced three kinds of picrate powders, composed as follows:-- ___________________________________________________________________ | | | | | | | For Torpedoes | For Guns. | For Small | | | and Shells. | Ordinary. Heavy. | Arms. | |___________________|_______________|___________________|___________| | | | | | | | Picrate of Potash | 55-50 | 16.4- 9.6 | 9 | 28.6-22.9 | | Saltpetre | 45-50 | 74.4-79.7 | 80 | 65.0-69.4 | | Charcoal | ... | 9.2-10.7 | 11 | 6.4- 7.7 | |___________________|_______________|___________|_______|___________| They were made much like ordinary gunpowder, 6 to 14 per cent. of moisture being added when being milled. The advantages claimed over gunpowder are greater strength, and consequently greater ballistic or disruptive effect, comparative absence of smoke, and freedom from injurious action on the bores of guns, owing to the absence of sulphur. Brugère's powder is composed of ammonium picrate and nitre, the proportions being 54 per cent. picrate of ammonia and 46 per cent. potassic nitrate. It is stable, safe to manufacture and handle, but expensive. It gives good results in the Chassepôt rifle, very little smoke, and its residue is small, and consists of carbonate of potash. It is stated that 2.6 grms. used in a rifle gave an effect equal to 5.5 grms. of ordinary gunpowder. [Footnote A: The British Lydite and the Japanese Shimose are said to be identical with Melinite.] Turpin has patented various mixtures of picric acid, with gum-arabic, oils, fats, collodion jelly, &c. When the last-named substance is diluted in the proportion of from 3 to 5 per cent. in a mixture of ether and alcohol, he states that the blocks of picric acid moulded with it will explode in a closed chamber with a priming of from 1 to 3 grammes of fulminate. He also casts picric acid into projectiles, the cast acid having a density of about 1.6. In this state it resists the shock produced by the firing of a cannon, when contained in a projectile, having an initial velocity of 600 metres. It is made in the following way:--The acid is fused in a vessel provided with a false bottom, heated to 130° to 145° C. by a current of steam under pressure, or simply by the circulation under the false bottom of a liquid, such as oil, chloride of zinc, glycerine, &c., heated to the same temperature. The melted picric acid is run into moulds of a form corresponding to that of the blocks required, or it may be run into projectiles, which should be heated to a temperature of about 100° C., in order to prevent too rapid solidification. When cresylic acid (or cresol, C_{6}H_{4}(CH_{3})OH.) is acted upon by nitric acid it produces a series of nitro compounds very similar to those formed by nitric acids on phenol, such as sodium di-nitro-cresylate, known in the arts as victoria yellow. Naphthol, a phenol-like body obtained from naphthalene, under the same conditions, produces sodium di-nitro- naphthalic acid, C_{10}H_{6}(NO_{2})_{2}O. The explosive known as "roburite" contains chloro-nitro-naphthalene, and romit, a Swedish explosive, nitro-naphthalene. ~Tri-nitro-cresol~, C_{7}H_{4}(NO_{2})_{3}OH.--A body very similar to tri- nitro-phenol, crystallises in yellow needles, slightly soluble in cold water, rather more so in boiling water, alcohol, and ether. It melts at about 100° C. In France it is known as "Cresilite," and mixed with melinite, is used for charging shells. By neutralising a boiling saturated solution of tri-nitro-cresol with ammonia, a double salt of ammonium and nitro-cresol crystallises out upon cooling, which is similar to ammonium picrate. This salt is known as "Ecrasite," and has been used in Austria for charging shells. It is a bright yellow solid, greasy to the touch, melts at 100° C., is unaffected by moisture, heat, or cold, ignites when brought into contact with an incandescent body or open flame, burning harmlessly away unless strongly confined, and is insensitive to friction or concussion. It is claimed to possess double the strength of dynamite, and requires a special detonator (not less than 2 grms. of fulminate) to provoke its full force. Notwithstanding the excellent properties attributed to this explosive, Lieut. W. Walke ("Lectures on Explosives," p. 181) says, "Several imperfectly explained and unexpected explosions have occurred in loading shells with this substance, and have prevented its general adoption up to the present time." ~The Fulminates.~--The fulminates are salts of fulminic acid, C_{2}N_{2}O_{2}H_{2}. Their constitution is not very well understood. Dr E. Divers, F.R.S., and Mr Kawakita (_Chem. Soc. Jour._, 1884, pp. 13-19), give the formulæ of mercury and silver fulminates as OC = N AgOC = N / | \ | \ Hg | O and | O \ | / | / -C = N AgC = N whereas Dr H.E. Armstrong, F.R.S., would prefer to write the formula of fulminic acid ON.C.OH. | C(N.OH), and A.F. Holleman (_Berichte_, v. xxvi., p. 1403), assigns to mercury fulminate the formula C:N.O Hg | | C:N.O, and R. Schol (_Ber._, v. xxiii., p. 3505), C:NO || Hg. C:NO They are very generally regarded as iso-nitroso compounds. The principal compound of fulminic acid is the mercury salt commonly known as fulminating mercury. It is prepared by dissolving mercury in nitric acid, and then adding alcohol to the solution, 1 part of mercury and 12 parts of nitric acid of specific gravity 1.36, and 5-1/2 parts of 90 per cent. alcohol being used. As soon as the mixture is in violent reaction, 6 parts more of alcohol are added slowly to moderate the action. At first the mixture blackens from the separation of mercury, but this soon vanishes, and is succeeded by crystalline flocks of mercury fulminate which fall to the bottom of the vessel. During the reaction, large quantities of volatile oxidation products of alcohol, such as aldehyde, ethylic nitrate, &c., are evolved from the boiling liquid, whilst others, such as glycollic acid, remain in solution. The mercury fulminate is then crystallised from hot water. It forms white silky, delicate needles, which are with difficulty soluble in cold water. In the dry state it is extremely explosive, detonating on heating, or by friction or percussion, as also on contact with concentrated sulphuric acid. The reaction that takes place upon its decomposition is as follows:-- C_{2}N_{2}O_{2}Hg = Hg + 2CO + N_{2} (284) According to this equation 1 grm. of the fulminate should yield 235.8 c.c. (= 66.96 litres for 284 grms.). Berthelot and Vicille have obtained a yield of 234.2 c.c., equal to 66.7 litres for one equivalent 284 grms. Dry fulminate explodes violently when struck, compressed, or touched with sulphuric acid, or as an incandescent body. If heated slowly, it explodes at 152° C., or if heated rapidly, at 187° C. It is often used mixed with potassium chlorate in detonators. The reaction which takes place in this case is 3C_{2}N_{2}O_{2}Hg + 2KClO_{3} = 3Hg + 6CO_{2} + 3N_{2} + 2KCl. On adding copper or zinc to a hot saturated solution of the salt, fulminate of copper or zinc is formed. The copper salt forms highly explosive green crystals. There is also a double fulminate of copper of ammonia, and of copper and potassium. Silver fulminite, C_{2}N_{2}O_{2}Ag_{2}, is prepared in a similar manner to the mercury salt. It separates in fine white needles, which dissolve in 36 parts of boiling water, and are with difficulty soluble in cold water. At above 100° C., or on the weakest blow, it explodes with fearful violence. Even when covered with water it is more sensitive than the mercury salt. It forms a very sensitive double salt with ammonia and several other metals. With hydrogen it forms the acid fulminate of silver. It is used in crackers and bon-bons, and other toy fireworks, in minute quantities. Gay Lussac found it to be composed as follows:--Carbon, 7.92 per cent.; nitrogen, 9.24 per cent.; silver, 72.19 per cent.; oxygen, 10.65 per cent.; and he assigned to it the formula, C_{2}N_{2}Ag_{2}O_{2}. Laurent and Gerhardt give it the formula, C_{2}N(NO_{2})Ag_{2}, and thus suppose it to contain nitryl, NO_{2}. On adding potassium chloride to a boiling solution of argentic fulminate, as long as a precipitate of argentic chloride forms, there is obtained on evaporation brilliant white plates, of a very explosive nature, of potassic argentic fulminate, C(NO_{2})KAg.CN, from whose aqueous solution nitric acid precipitates a white powder of hydric argentic fulminate, C(NO_{2})HAg.CN. All attempts to prepare fulminic acid, or nitro-aceto- nitrile, C(NO_{2})H_{2}CN, from the fulminates have failed. There is a fulminate of gold, which is a violently explosive buff precipitate, formed when ammonia is added to ter-chloride of gold, and fulminate of platinum, a black precipitate formed by the addition of ammonia to a solution of oxide platinum, in dilute sulphuric acid. Fulminating silver is a compound obtained by the action of ammonia on oxide of silver. It is a very violent explosive. Pure mercury fulminate may be kept an indefinite length of time. Water does not affect it. It explodes at 187° C., and on contact with an ignited body. It is very sensitive to shock and friction, even that of wood upon wood. It is used for discharging bullets in saloon rifles. Its inflammation is so sudden that it scatters black powder on which it is placed without igniting it, but it is sufficient to place it in an envelope, however weak, for ignition to take place, and the more resisting the envelope the more violent is the shock, a circumstance that plays an important part in caps and detonators. The presence of 30 per cent. of water prevents decomposition, 10 per cent. prevents explosion. This is, however, only true for small quantities, and does not apply to silver fulminate, which explodes under water by friction. Moist fulminates slowly decompose on contact with the oxidisable metals. The (reduced) volume of gases obtained from 1 kilo. is according to Berthelot, 235.6 litres. The equation of its decomposition is C_{2}HgN_{2}O_{2} = 2CO + N_{2} + Hg. Fulminate of mercury is manufactured upon the large scale by two methods. One of these, commonly known as the German method, is conducted as follows:--One part of mercury is dissolved in 12 parts of nitric acid of a specific gravity of 1.375, and to this solution 16.5 parts of absolute alcohol are added by degrees, and heat is then slowly applied to the mixture until the dense fumes first formed have disappeared, and when the action has become more violent some more alcohol is added, equal in volume to that which has already been added. This is added very gradually. The product obtained, which is mercury fulminate, is 112 per cent. of the mercury employed. Another method is to dissolve 10 parts of mercury in 100 parts of nitric acid of a gravity of 1.4, and when the solution has reached a temperature of 54° C, to pour it slowly through a glass funnel into 83 parts of alcohol. When the effervescence ceases, it is filtered through paper filters, washed, and dried over hot water, at a temperature not exceeding 100° C. The fulminate is then carefully packed in paper boxes, or in corked bottles. The product obtained by this process is 130 per cent. of the mercury taken. This process is the safest, and at the same time the cheapest. Fulminate should be kept, if possible, in a damp state. Commercial fulminate is often adulterated with chlorate of potash. ~Detonators~, or caps, are metallic capsules, usually of copper, and resemble very long percussion caps. The explosive is pure fulminate of mercury, or a mixture of that substance with nitrate or chlorate of potash, gun-powder, or sulphur. The following is a common cap mixture:-- 100 parts of fulminate of mercury and 50 parts of potassium nitrate, or 100 parts of fulminate and 60 parts of meal powder. Silver fulminate is also sometimes used in caps. There are eight sizes made, which vary in dimensions and in amount of explosive contained. They are further distinguished as singles, doubles, trebles, &c., according to their number. Colonel Cundill, R.A. ("Dict. of Explosives"), gives the following list:-- No. 1 contains 300 grms. of explosive per 1000. " 2 " 400 " " " " " " 3 " 540 " " " " " " 4 " 650 " " " " " " 5 " 800 " " " " " " 6 " 1,000 " " " " " " 7 " 1,500 " " " " " " 8 " 2,000 " " " " " Trebles are generally used for ordinary dynamite, 5, 6, or 7 for gun-cotton, blasting gelatine, roburite, &c. In the British service percussion caps, fuses, &c., are formed of 6 parts by weight of fulminate of mercury, 6 of chlorate of potash, and 4 of sulphide of antimony; time fuses of 4 parts of fulminate, 6 of potassium chlorate, 4 of sulphide of antimony, the mixture being damped with a varnish consisting of 645 grains of shellac dissolved in a pint of methylated spirit. Abel's fuse (No. 1) consists of a mixture of sulphide of copper, phosphide of copper, chlorate of potash, and No. 2 of a mixture of gun-cotton and gun-powder. They are detonated by means of a platinum wire heated to redness by means of an electric current. Bain's fuse mixture is a mixture of subphosphide of copper, sulphide of antimony, and chlorate of potash. In the manufacture of percussion caps and detonators the copper blanks are cut from copper strips and stamped to the required shape. The blanks are then placed in a gun-metal plate, with the concave side uppermost--a tool composed of a plate of gun-metal, in which are inserted a number of copper points, each of the same length, and so spaced apart as to exactly fit each point into a cap when inverted over a plate containing the blanks. The points are dipped into a vessel containing the cap composition, which has been previously moistened with methylated spirit. It is then removed and placed over the blanks, and a slight blow serves to deposit a small portion of the cap mixture into each cap. A similar tool is then dipped into shellac varnish, removed and placed over the caps, when a drop of varnish from each of the copper points falls into the caps, which are then allowed to dry. This is a very safe and efficacious method of working. At the works of the Cotton-Powder Company Limited, at Faversham, the fulminate is mixed wet with a very finely ground mixture of gun-cotton and chlorate of potash, in about the proportions of 6 parts fulminate, 1 part gun-cotton, and 1 part chlorate. The water in which the fulminate is usually stored is first drained off, and replaced by displacement by methyl-alcohol. While the fulminate is moist with alcohol, the gun-cotton and chlorate mixture is added, and well mixed with it. This mixture is then distributed in the detonators standing in a frame, and each detonator is put separately into a machine for the purpose of pressing the paste into the detonator shell. At the eleventh annual meeting of the representatives of the Bavarian chemical industries at Regensburg, attention was drawn to the unhealthy nature of the process of charging percussion caps. Numerous miniature explosions occur, and the air becomes laden with mercurial vapours, which exercise a deleterious influence upon the health of the operatives. There is equally just cause for apprehension in respect to the poisonous gases which are evolved during the solution of mercury in nitric acid, and especially during the subsequent treatment with alcohol. Many methods have been proposed for dealing with the waste products arising during the manufacture and manipulation of fulminate of mercury, but according to Kæmmerer, only one of comparatively recent introduction appears to be at all satisfactory. It is based upon the fact that mercuric fulminate, when heated with a large volume of water under high pressure, splits up into metallic mercury and non-explosive mercurial compounds of unknown composition. In mixing the various ingredients with mercury fulminate to form cap mixtures, they should not be too dry; in fact, they are generally more or less wet, and mixed in small quantities at a time, in a special house, the floors of which are covered with carpet, and the tables with felt. Felt shoes are also worn by the workpeople employed. All the tools and apparatus used must be kept very clean; for granulating, hair sieves are used, and the granulated mixture is afterwards dried on light frames, with canvas trays the bottoms of which are covered with thin paper, and the frames fitted with indiarubber cushions, to reduce any jars they may receive. The windows of the building should be painted white to keep out the rays of the sun. Mr H. Maxim, of New York, has lately patented a composition for detonators for use with high explosives, which can also be thrown from ordnance in considerable quantities with safety. The composition is prepared as follows:--Nitro-glycerine is thickened with pyroxyline to the consistency of raw rubber. This is done by employing about 75 to 85 per cent. of nitro-glycerine, and 15 to 25 per cent. of pyroxyline, according to the stiffness or elasticity of the compound desired. Some solvent that dissolves the nitro-cotton is also used. The product thus formed is a kind of blasting gelatine, and should be in a pasty condition, in order that it may be mixed with fulminate of mercury. The solvent used is acetone, and the quantity of fulminate is between 75 to 85 per cent. of the entire compound. If desired, the compound can be made less sensitive to shocks by giving it a spongy consistency by agitating it with air while it is still in a syrupy condition. The nitro-glycerine, especially in this latter case, may be omitted. In some cases, when it is desirable to add a deterring medium, nitro-benzene or some suitable gum is added. [Illustration: FIG. 34. METHOD OF PREPARING THE CHARGE.] The method of preparing a blasting charge is as follows:--A piece of Bickford fuse of the required length is cut clean and is inserted into a detonator until it reaches the fulminate. The upper portion of the detonator is then squeezed round the fuse with a pair of nippers. The object of this is not only to secure that the full power of the detonator may be developed, but also to fix the fuse in the cap (Fig. 34). When the detonator, &c., is to be used under water, or in a damp situation, grease or tallow should be placed round the junction of the cap with the fuse, in order to make a water-tight joint. A cartridge is then opened and a hole made in its upper end, and the detonator pushed in nearly up to the top. Gun-cotton or tonite cartridges generally have a hole already made in the end of the charge. Small charges of dry gun-cotton, known as primers, are generally used to explode wet gun-cotton. The detonators (which are often fired by electrical means) are placed inside these primers (Fig. 35). [Illustration: FIG. 35. PRIMER.] One of the forms of electric exploders used is shown in Fig. 36. This apparatus is made by Messrs John Davis & Son, and is simply a small hand dynamo, capable of producing a current of electricity of high tension. This firm are also makers of various forms of low tension exploders. A charge having been prepared, as in Fig. 34, insert into the bore-hole one or more cartridges as judged necessary, and squeeze each one down separately with a _wooden_ rammer, so as to leave no space round the charge, and above this insert the cartridge containing the fuse and detonator. Now fill up the rest of the bore-hole with sand, gravel, water, or other tamping. With gelatine dynamites a firm tamping may be used, but with ordinary dynamite loose sand is better. The charge is now ready for firing. [Illustration: FIG. 36.--ELECTRIC EXPLODER.] CHAPTER VI. _SMOKELESS POWDERS._ Smokeless Powder in General--Cordite--Axite--Ballistite--U.S. Naval Powder--Schultze's E.G. Powder--Indurite--Vielle Poudre--Rifleite-- Cannonite--Walsrode--Cooppal Powders--Amberite--Troisdorf--Maximite-- Picric Acid Powders, &c., &c. The progress made in recent years in the manufacture of smokeless powders has been very great. With a few exceptions, nearly all these powders are nitro compounds, and chiefly consist of some form of nitro-cellulose, either in the form of nitro-cotton or nitro-lignine; or else contain, in addition to the above, nitro-glycerine, with very often some such substance as camphor, which is used to reduce the sensitiveness of the explosive. Other nitro bodies that are used, or have been proposed, are nitro-starch, nitro-jute, nitrated paper, nitro-benzene, di-nitro-benzene, mixed with a large number of other chemical substances, such as nitrates, chlorates, &c. And lastly, there are the picrate powders, consisting of picric acid, either alone or mixed with other substances. The various smokeless powders may be roughly divided into military and sporting powders. But this classification is very rough; because although some of the better known purely military powders are not suited for use in sporting guns, nearly all the manufacturers of sporting powders also manufacture a special variety of their particular explosive, fitted for use in modern rifles or machine guns, and occasionally, it is claimed, for big guns also. Of the purely military powders, the best known are cordite, ballistite, and the French B.N. powder, the German smokeless (which contains nitro- glycerine and nitro-cotton); and among the general powders, two varieties of which are manufactured either for rifles or sporting guns, Schultze's, the E.C. Powders, Walsrode powder, cannonite, Cooppal powder, amberite, &c., &c. ~Cordite~, the smokeless powder adopted by the British Government, is the patent of the late Sir F.A. Abel and Sir James Dewar, and is somewhat similar to blasting gelatine. It is chiefly manufactured at the Royal Gunpowder Factory at Waltham Abbey, but also at two or three private factories, including those of the National Explosives Company Limited, the New Explosives Company Limited, the Cotton-Powder Company Limited, Messrs Kynock's, &c. As first manufactured it consisted of gun-cotton 37 per cent., nitro-glycerine 58 per cent., and vaseline 5 per cent., but the modified cordite now made consists of 65 per cent. gun-cotton, 30 per cent. of nitro-glycerine, and 5 per cent. of vaseline. The gun-cotton used is composed chiefly of the hexa-nitrate,[A] which is not soluble in nitro- glycerine. It is therefore necessary to use some solvent such as acetone, in order to form the jelly with nitro-glycerine. The process of manufacture of cordite is very similar, as far as the chemical part of the process is concerned, to that of blasting gelatine, with the exception that some solvent for the gun-cotton, other than nitro-glycerine has to be used. Both the nitro-glycerine and the gun-cotton employed must be as dry as possible, and the latter should not contain more than .6 per cent. of mineral matter and not more than 10 per cent. of soluble nitro-cellulose, and a nitrogen content of not less than 12.5 per cent. The dry gun-cotton (about 1 per cent. of moisture) is placed in an incorporating tank, which consists of a brass-lined box, some of the acetone is added, and the machine (Fig. 29), is started; after some time the rest of the acetone is added (20 per cent. in all) and the paste kneaded for three and a half hours. At the end of this time the Vaseline is added, and the kneading continued for a further three and a half hours. The kneading machine (Fig. 29) consists of a trough, composed of two halves of a cylinder, in each of which is a shaft which carries a revolving blade. These blades revolve in opposite directions, and one makes about half the number of revolutions of the other. As the blades very nearly touch the bottom of the trough, any material brought into the machine is divided into two parts, kneaded against the bottom, then pushed along the blade, turned over, and completely mixed. During kneading the acetone gradually penetrates the mixture, and dissolves both the nitro-cellulose and nitro-glycerine, and a uniform dough is obtained which gradually assumes a buff colour. During kneading the mass becomes heated, and therefore cold water is passed through the jacket of the machine to prevent heating the mixture above the normal temperature, and consequent evaporation of the acetone. The top of the machine is closed in with a glass door, in order to prevent as far as possible the evaporation of the solvent. When the various ingredients are formed into a homogeneous mass, the mixture is taken to the press house, where in the form of a plastic mass it is placed in cylindrical moulds. The mould is inserted in a specially designed press, and the cordite paste forced through a die with one or more holes. The paste is pressed out by hydraulic pressure, and the long cord is wound on a metal drum (Fig. 38), or cut into lengths; in either case the cordite is now sent to the drying houses, and dried at a temperature of about 100° F. from three to fourteen days, the time varying with the size. This operation drives off the acetone, and any moisture the cordite may still contain, and its diameter decreases somewhat. In case of the finer cordite, such as the rifle cordite, the next operation is blending. This process consists in mounting ten of the metal drums on a reeling machine similar to those used for yarns, and winding the ten cords on to one drum. This operation is known as "ten-stranding." Furthermore, six "ten-stranded" reels are afterwards wound upon one, and the "sixty-stranded" reel is then ready to be sent away, This is done in order to obtain a uniform blending of the material. With cordite of a larger diameter, the cord is cut into lengths of 12 inches. Every lot of cordite from each manufacturer has a consecutive number, numbers representing the size and one or more initial letters to identify the manufacturer. These regulations do not apply to the Royal Gunpowder Factory, Waltham Abbey. The finished cordite resembles a cord of gutta-percha, and its colour varies from light to dark brown. It should not look black or shrivelled, and should always possess sufficient elasticity to return to its original form after slight bending. Cordite is practically smokeless. On explosion a very thin vapour is produced, which is dissipated rapidly. This smokelessness can be understood from the fact that the products of combustion are nearly all non-condensible gases, and contain no solid products of combustion which would cause smoke. For the same muzzle velocity a smaller charge of cordite than gunpowder is required owing to the greater amount of gas produced. Cordite is very slow in burning compared to gunpowder. For firing blank cartridges cordite chips containing no vaseline is used. The rate at which cordite explodes depends in a measure upon the diameter of the cords, and the pressure developed upon its mechanical state. The sizes of cordite used are given by Colonel Barker, R.A., as follows:-- For the .303 rifle .0375 inch diameter. " 12 Pr. B.L. gun .05 " " " .075 " " 4.7-inch Q.F. gun .100 " " 6-inch Q.F. gun .300 " " heavy guns .40 to .50 " For rifles the cordite is used in bundles of sixty strands, in field-guns in lengths of 11 to 12 inches, and the thicker cordite is cut up into 14-inch lengths. Colonel Barker says that the effect of heat upon cordite is not greater as regards its shooting qualities than upon black powder, and in speaking of the effect that cordite has upon the guns in which it is used (R.A. Inst.) said that they had at Waltham Abbey a 4.7-inch Q.F. gun that had fired 40 rounds of black powder, and 249 rounds of cordite (58 per cent. nitro-glycerine) and was still in excellent condition, and showed very little sign of action, and also a 12-lb. B.L. gun that had been much used and was in no wise injured. [Footnote A: The gun-cotton used contains 12 per cent. of soluble gun-cotton, and a nitrogen content of not less than 12.8 to 13.1 per cent.] [Illustration: Fig. 37 Scale, 1 inch = 1 foot. Single Strand Reel.] [Illustration: FIG. 38.--"TEN-STRANDING."] In some experiments made by Captain Sir A. Noble,[A] with the old cordite containing 58 per cent. nitro-glycerine, a charge of 5 lbs. 10 oz. of cordite of 0.2 inch diameter was fired. The mean chamber crusher gauge pressure was 13.3 tons per square inch (maximum 13.6, minimum 12.9), or a mean of 2,027 atmospheres (max. 2,070, min. 1,970). The muzzle velocity was 2,146 foot seconds, and the muzzle energy 1,437 foot tons. A gramme of cordite generated 700 c.c. of permanent gases at 0° C. and 760 mm. pressure. The quantity of heat developed was 1,260 gramme units. In the case of cordite, as also with ballistite, a considerable quantity of aqueous vapour has to be added to the permanent gases formed. A similar trial, in which 12 lbs. of ordinary pebble powder was used, gave a pressure of 15.9 tons per square inch, or a mean of 2,424 atmospheres. It gave a 45-lb. projectile a mean muzzle velocity of 1,839 foot seconds, thus developing a muzzle energy of 1,055 foot tons. A gramme of this powder at 0° C. and 760 mm. generates 280 c.c. of permanent gases, and develops 720 grm. units of heat. [Footnote A: _Proc. Roy. Soc._, vol. lii., No. 315.] In a series of experiments conducted by the War Office Chemical Committee on Explosives in 1891, it was conclusively shown that considerable quantities of cordite may be burnt away without explosion. A number of wooden cases, containing 500 to 600 lbs. each of cordite, were placed upon a large bonfire of wood, and burned for over a quarter of an hour without explosion. At Woolwich in 1892 a brown paper packet containing ten cordite cartridges was fired into with a rifle (.303) loaded with cordite, without the explosion of a single one of them, which shows its insensibility to shock. With respect to the action of cordite upon guns, Sir A. Noble points out that the erosion caused is of a totally different kind to that of black powder. The surface of the barrel in the case of cordite appears to be washed away smoothly by the gases, and not pitted and eaten into as with black powder. The erosion also extends over a shorter length of surface, and in small arms it is said to be no greater than in the case of black powder. Sir A. Noble says in this connection: "It is almost unnecessary to explain that freedom from rapid erosion is of very high importance in view of the rapid deterioration of the bores of large guns when fired with charges developing very high energies. As might perhaps be anticipated from the higher heat of ballistite, its erosive power is slightly greater than that of cordite, while the erosive power of cordite is again slightly greater than that of brown prismatic. Amide powder, on the other hand, possesses the peculiarity of eroding very much less than any other powder with which I have experimented, its erosive power being only one-fourth of that of the other powders enumerated." TABLE GIVING SOME OF SIR. A. NOBLE'S EXPERIMENTS. ________________________________________________________________________ | | | VELOCITIES OBTAINED. | |________________________________________________________________________| | | | | | | | | In a 40 | In a 50 | In a 75 | In a 100 | | | Cal. Gun.| Cal. Gun.| Cal. Gun.| Cal. Gun.| |____________________________|__________|__________|__________|__________| | | | | | | | |Foot Secs.|Foot Secs.|Foot Sees.|Foot Secs.| | | | | | | |With cordite 0.4 in. diam. | 2,794 | 2,940 | 3,166 | 3,286 | | " " 0.3 " | 2,469 | 2,619 | 2,811 | 2,905 | | " ballistite 0.3 in. cubes| 2,416 | 2,537 | 2,713 | 2,806 | | " French B.N. for | | | | | | 6-inch guns | 2,249 | 2,360 | 2,536 | 2,616 | | " prismatic amide | 2,218 | 2,342 | 2,511 | 2,574 | | | | | | | |____________________________|__________|__________|__________|__________| | | | ENERGIES REPRESENTED BY ABOVE VELOCITIES. | |________________________________________________________________________| | | | | | | | |Foot Tons.|Foot Tons.|Foot Tons.|Foot Tons.| | | | | | | | Cordite 0.4 inch | 5,413 | 5,994 | 6,950 | 7,478 | | Ballistite 0.3 inch cubes | 4,227 | 4,754 | 5,479 | 5,852 | | French B.N. | 4,047 | 4,463 | 5,104 | 5,460 | | Prismatic amide | 3,507 | 3,862 | 4.460 | 4,745 | |____________________________|__________|__________|__________|__________| And again, in speaking of his own experiments, he says: "One 4.7-inch gun has fired 1,219 rounds, and another 953, all with full charges of cordite, while a 6-inch gun has fired 588 rounds with full charges, of which 355 were cordite. In the whole of these guns, so far as I can judge, the erosion is certainly not greater than with ordinary powder, and differs from it remarkably in appearance. With ordinary powder a gun, when much eroded, is deeply furrowed (these furrows having a great tendency to develop into cracks), and presents much the appearance in miniature of a very roughly ploughed field. With cordite, on the contrary, the surface appears to be pretty smoothly swept away, while the length of the surface eroded is considerably less." [Illustration: FIG. 39.--COMPARATIVE PRESSURE CURVES OF CORDITE AND BLACK POWDER. _a_, Charge, 48 lbs. powder; _b_, charge, 13 lbs. 4 oz. cordite; _c_, charge, 13 lbs. 4 oz. powder. Weight of projectile, 100 lbs. in 6-inch gun. M.V. Cordite = 1960 feet seconds.] The pressures given by cordite compared with those given by black powder in the 6-inch gun will be seen upon reference to Fig. 39, which is taken from Professor V.B. Lewes's paper, read before the Society of Arts; and due to Dr W. Anderson, F.R.S., the Director-General of Ordnance Factories. It has been found that the erosive effect is in direct proportion to the nitro-glycerine present. The cordite M.D., which contains only 30 per cent. nitro-glycerine, gives only about half the erosive effect of the old service cordite. With regard to the heating effect of cordite and cordite M.D. on a rifle, Mr T.W. Jones made some experiments. He fired fifty rounds of .303 cartridges in fifteen minutes in the service rifle. Cordite raised the temperature of the rifle 270° F., and cordite M.D. 160° F. only. With regard to the effect of heat upon cordite, there is some difference of opinion. Dr W. Anderson, F.R.S., says that there is no doubt that the effect of heat upon cordite is greater than upon black powder. At a temperature of 110° F. the cordite used in the 4.7-inch gun is considerably affected as regards pressure. Colonel Barker, R.A., in reply to a question raised by Colonel Trench, R.A. (at the Royal Artillery Institution), concerning the shooting qualities of cordite heated to a temperature of 110° F., said: "Heating cordite and firing it hot undoubtedly does disturb its shooting qualities, but as far as we can see, not much more than gunpowder. I fear that we must always expect abnormal results with heated propellants, either gunpowder or cordite; and when fired hot, the increase in pressure and velocities will depend upon the heat above the normal or average temperature at which firing takes place." Colonel Barker also, in referring to experiments that had been made in foreign climates, said: "Climatic trials have been carried out all over the world, and they have so far proved eminently satisfactory. The Arctic cold of the winter in Canada, with the temperature below zero, and the tropical sun of India, have as yet failed to shake the stability of the composition, or abnormally injure its shooting qualities." Dr Anderson is of opinion that cordite should not be stored in naval magazines near to the boilers. Professor Vivian B. Lewes, in his recent Cantor Lectures before the Society of Arts, suggests that the magazines of warships should be water- jacketed, and maintained at a temperature that does not rise above 100° F. ~Axite.~--This powder is manufactured by Messrs Kynock Limited, at their works at Witton, Birmingham. The main constituents of cordite are retained although the proportions are altered; ingredients are added which impart properties not possessed by cordite, and the methods of its manufacture have been modified. The form has also been altered. Axite is made in the form of a ribbon, the cross section being similar in shape to a double- headed rail. It is claimed for this powder, that it does not corrode the barrel in the way cordite does, that with equal pressure it gives greatly increased velocity, and therefore flatter trajectory. That the effect of temperature on the pressure and velocity with axite is only half that with cordite. That the maximum flame temperature of axite is considerably less than that of cordite, and the erosive effect is therefore considerably less. That the deposit left in the barrel after firing axite cartridges reduces the friction between the bullet and the barrel. It is therefore practicable to use axite cartridges giving higher velocities than can be employed with cordite, as with such velocities the latter would nickel the barrel by excessive friction. It is also claimed that the accuracy is greatly increased. The following results have been obtained with this same time, and under the same conditions:-- ~Axite~ Cartridges with 200-grain bullets. Velocity 2,726 F.S. Pressure 20.95 tons. ~Axite~ Cartridges with 215-grain bullets. Velocity 2,498 F.S. Pressure 19.24 tons. ~Axite~ Service Cartridges. Velocity 2,179 F.S. Pressure 15.76 tons. ~Cordite~ Service Cartridges. Velocity 2,010 F.S. Pressure 15.67 tons. Five rounds from the Service axite and Service cordite were placed in an oven and heated to a temperature of 110° F. for one hour, and were then fired for pressure. The following results were obtained:-- ~Axite.~ ~Cordite.~ Before heating 15.76 tons per sq. in. 15.67 tons per sq. in. After " 16.73 " " 17.21 " " _____ _____ Increase .97 = 6.1% 1.54 = 9.8% Average Velocities-- Before heating 2,150 F.S. 2,030 F.S. After " 2,180 " 2,090 " _____ _____ Increase 30 F.S. = 1-1/2% 60.0 F.S. = 3% In order to show the accuracy given by axite, seven rounds were fired from a machine rest at a target fixed at 100 yards from a rifle. Six of the seven shots could be covered by a penny piece, the other being just outside. In order to ascertain the relative heat imparted to a rifle by the explosion of axite and cordite, ten rounds each of axite and cordite cartridges were fired from a .303 rifle, at intervals of ten seconds, the temperature of the rifle barrel being taken before and after each series:-- THE RISE IN TEMPERATURE OF THE RIFLE BARREL With axite was 71° F. With cordite was 89° F. Difference in favour of axite 18° F. = 20.2% The lubricating action of axite is shown by the fact that a series of cordite cartridges fired from a .303 rifle in the ordinary way, followed by a second series, the barrel being lubricated between each shot by firing an axite cartridge alternately with the cordite cartridge. The mean velocity of the first series of cordite cartridges was 1,974 ft. per second; the mean velocity of the second series was 2,071 ft. per second; the increased velocity due to the lubricating effect of axite therefore was 97 ft. per second. This powder, it is evident, has very many very excellent qualities, and considerable advantages over cordite. It is understood that axite is at present under the consideration of the British Government for use as the Service powder. ~Ballistite.~--Nobel's powder, known as ballistite, originally consisted of a camphorated blasting gelatine, and was made of 10 parts of camphor in 100 parts of nitro-glycerine, to which 200 parts of benzol were then added, and 50 parts of nitro-cotton (soluble) were then steeped in this mixture, which was then heated to evaporate off the benzol, and the resulting compound afterwards passed between steam-heated rollers, and formed into sheets, which were then finally cut up into small squares or other shapes as convenient. The camphor contained in this substance was, however, found to be a disadvantage, and its use discontinued. The composition is now 50 per cent. of soluble nitro-cotton and 50 per cent. of nitro-glycerine. As nitro-glycerine will not dissolve its own weight of nitro-cotton (even the soluble variety), benzol is used as a solvent, but is afterwards removed from the finished product, just as the acetone is removed from cordite. About 1 per cent. of diphenylamine is added for the purpose of increasing its stability. The colour of ballistite is a darkish brown. It burns in layers when ignited, and emits sparks. The size of the cubes into which it is cut is a 0.2-inch cube. Its density is 1.6. It is also, by means of a special machine, prepared in the form of sheets, after being mixed in a wooden trough fitted with double zinc plates, and subjected to the heating process by means of hot-water pipes. It is passed between hot rollers, and rolled into sheets, which are afterwards put through a cutting machine and granulated. Sir A. Nobel's experiments[A] with this powder gave the following results:--The charge used was 5 lbs. 8 oz., the size of the cubes being 0.2 inch. The mean crusher-gauge pressure was 14.3 tons per square inch (maximum, 2,210; minimum, 2,142), and average pressure 2,180 atmospheres. The muzzle velocity was 2,140 foot seconds, and the muzzle energy 1,429 foot tons. A gramme of ballistite generates 615 c.c. of permanent gases, and gives rise to 1,365 grm. units of heat. Ballistite is manufactured at Ardeer in Scotland, at Chilworth in Surrey, and also in Italy, under the name of Filite, which is in the form of cords instead of cubes. The ballistite made in Germany contained more nitro-cellulose, and the finished powder was coated with graphite. Its use has been discontinued as the Service powder in Germany, but it is still the Service powder in Italy. [Footnote A: _Proc. Roy. Soc._, vol. lii., p. 315.] ~U.S. Naval Smokeless Powder.~--This powder is manufactured at the U.S. Naval Torpedo Station for use in guns of all calibres in the U.S. Navy. It is a nitro-cellulose powder, a mixture of insoluble and soluble nitro- cellulose together with the nitrates of barium and potassium, and a small percentage of calcium carbonate. The proportions in the case of the powder for the 6-inch rapid-fire gun are as follows:--Mixed nitro-cellulose (soluble and insoluble) 80 parts, barium nitrate 15 parts, potassium nitrate 4 parts, and calcium carbonate 1 part. The percentage of nitrogen contained in the insoluble nitro-cellulose must be 13.30±0.15, and in the soluble 11.60±0.15, and the mean nitration strength of the mixture must be 12.75 per cent. of nitrogen. The solvent used in making the powder is a mixture of ether (sp. gr. 0.720) 2 parts, and alcohol (95 per cent. by volume) 1 part. The process of manufacture is briefly as follows:[A]--The soluble and insoluble nitro-cellulose are dried separately at a temperature from 38° to 41° C., until they do not contain more than 0.1 per cent. of moisture. The calcium carbonate is also finely pulverised and dried, and is added to the mixed nitro-celluloses after they have been sifted through a 16-mesh sieve. The nitrates are next weighed out and dissolved in hot water, and to this solution is added the mixture of nitro-celluloses and calcium carbonate with constant stirring until the entire mass becomes a homogeneous paste. This pasty mass is next spread upon trays and re-dried at a temperature between 38° and 48° C., and when thoroughly dry it is transferred to the kneading machine. The ether- alcohol mixture is now added, and the process of kneading begun. It has been found by experiment that the amount of solvent required to secure thorough incorporation is about 500 c.c. to each 500 grms. of dried paste. To prevent loss of solvent due to evaporation, the kneading machine is made vapour light. The mixing or kneading is continued until the resulting greyish-yellow paste is absolutely homogeneous so far as can be detected by the eye, which requires from three to four hours. The paste is next treated in a preliminary press (known as the block press and is actuated by hydraulic power), where it is pressed into a cylindrical mass of uniform density and of such dimensions as to fit it for the final or powder press. The cylindrical masses from the block press are transferred to the final press, whence they are forced out of a die under a pressure of about 500 lbs. per square inch. As it emerges from the final press the powder is in the form of a ribbon or sheet, the width and thickness of which is determined by the dimensions of the powder chamber of the gun in which the powder is to be used. On the inner surface of the die are ribs extending in the direction of the powder as it emerges from the press, the object of these ribs being to score the sheets or ribbons in the direction of their length, so that the powder will yield uniformly to the pressure of the gases generated in the gun during the combustion of the charge. The ribbon or sheet is next cut into pieces of a width and length corresponding to the chamber of the gun for which it is intended, the general rule being that the thickness of the grain (when perfectly dry) shall be fifteen one-thousandths (.015) of the calibre of the gun, and the length equal to the length to fit the powder chamber. Thus, in case of the 6-inch rapid-fire gun the thickness of the grain (or sheet) is 0.09 of an inch and the length 32 inches. The sheets are next thoroughly dried, first between sheets of porous blotting-paper under moderate pressure and at a temperature between 15° C. and 21.5° C. for three days, and then exposed to free circulation of the air at about 21.5° C. for seven days, and finally subjected for a week or longer to a temperature not exceeding 38° C. until they cease to lose weight. [Footnote A: Lieut. W. Walke, "Lectures on Explosives," p. 330.] The sheets, when thoroughly dried, are of a uniform yellowish-grey colour, and of the characteristic colloidal consistency; they possess a perfectly smooth surface, and are free from internal blisters or cracks. The temperature of ignition of the finished powder should not be below 172° C., and when subjected to the heat or stability test, it is required to resist exposure to a temperature of 71° C. for thirty minutes without causing discoloration of the test paper. ~W.A. Powder.~--This powder is made by the American Smokeless Powder Company, and it was proposed for use in the United States Army and Navy. It is made in several grades according to the ballistic conditions required. It consists of insoluble gun-cotton and nitro-glycerine, together with metallic nitrates and an organic substance used as a deterrent or regulator. The details of its manufacture are very similar to those of cordite, with the exception that the nitro-glycerine is dissolved in a portion of the acetone, before it is added to the gun-cotton. The powder is pressed into solid threads, or tubular cords or cylinders, according to the calibre of the gun in which the powder is to be used. As the threads emerge from the press they are received upon a canvas belt, which passes over steam-heated pipes, and deposited in wire baskets. The larger cords or cylinders are cut into the proper lengths and exposed upon trays in the drying-house. The powder for small arms is granulated by cutting the threads into short cylinders, which are subsequently tumbled, dusted, and, if not perfectly dry, again placed upon trays in the drying- house. Before being sent away from the factory, from five to ten lots of 500 lbs. each are mixed in a blending machine, in order to obtain greater uniformity. The colour of the W.A. powder is very light grey, the grains are very uniform in size, dry and hard. The powder for larger guns is of a yellowish colour, almost translucent, and almost as hard as vulcanite. The powder is said to be unaffected by atmospheric or climatic conditions, to be stable, and to have given excellent ballistic results; it is not sensitive to the impact of bullets, and when ignited burns quietly, unless strongly confined. Turning now to the smokeless powders, in which the chief ingredient is nitro-cellulose in some form (either gun-cotton or nitro-lignine, &c.), one of the first of these was Prentice's gun-cotton, which consisted of nitrated paper 15 parts, mixed with 85 parts of unconverted cellulose. It was rolled into a cylinder. Another was Punshon's gun-cotton powder, which consisted of gun-cotton soaked in a solution of sugar, and then mixed with a nitrate, such as sodium or potassium nitrate. Barium nitrate was afterwards used, and the material was granulated, and consisted of nitrated gun-cotton. The explosive known as tonite, made at Faversham, was at first intended for use as a gunpowder, but is now only used for blasting. ~The Schultze Powder.~--One of the earliest of the successful powders introduced into this country was Schultze's powder, the invention of Colonel Schultze, of the Prussian Artillery, and is now manufactured by the Schultze Gunpowder Company Limited, of London. The composition of this powder, as given in the "Dictionary of Explosives" by the late Colonel Cundall, is as follows:-- Soluble nitro-lignine 14.83 per cent. Insoluble " 23.36 " Lignine (unconverted) 13.14 " Nitrates of K and Ba 32.35 " Paraffin 3.65 " Matters soluble in alcohol 0.11 " Moisture 2.56 " This powder was the first to solve the difficulty of making a smokeless, or nearly smokeless powder which could be used with safety and success in small arms. Previously, gun-cotton had been tried in various forms, and in nearly every instance disaster to the weapon had followed, owing to the difficulty of taming the combustion to a safe degree. But about 1866 Colonel Schultze produced, as the result of experiments, a nitrated wood fibre which gave great promise of being more pliable and more easily regulated in its burning than gun-cotton, and this was at once introduced into England, and the Schultze Gunpowder Company Limited was formed to commence its manufacture, which it did in the year 1868. During the years from its first appearance, Schultze gunpowder has passed through various modifications. It was first made in a small cubical grain formed by cutting the actual fibre of timber transversely, and then breaking this veneer into cubes. Later on improvements were introduced, and the wood fibre so produced was crushed to a fine degree, and then reformed into small irregular grains. Again, an advance was made in the form of the wood fibre used, the fibre being broken down by the action of chemicals under high temperature, and so producing an extremely pure form of woody fibre. The next improvement was to render the grains of the powder practically waterproof and less affected by the atmospheric influences of moisture and dryness, and the last improvement to the process was that of hardening the grains by means of a solvent of nitro-lignine, so as to do away with the dust that was often formed from the rubbing of the grains during transit. Minor modifications have from time to time also been made, in order to meet the gradual alteration which has taken place during this long period in the manufacture of sporting guns and cartridge cases to be used with this powder, but through all its evolution this Company has adhered to the first idea of using woody fibre in preference to cotton as the basis of their smokeless powder, as experience has confirmed the original opinion that a powder can be thus made less sensitive to occasional differences in loading, and more satisfactory all round than when made from the cotton base. The powder has always been regulated so that bulk for bulk it occupies the same measure as the best black powder, and as regards its weight, just one half of that of black. The process of manufacture of this powder is briefly as follows:-- Wood of clean growth is treated by the well-known sulphite process for producing pure woody fibre, which is very carefully purified, and this, after drying, is steeped in a mixture of nitric and sulphuric acids, to render it a nitro-compound and the explosive base of the powder. This nitro compound is carefully purified until it stands the very high purity requirements of the Home Office, and is then ground with oxygen-bearing salts, &c., and the whole is formed into little irregular-shaped grains of the desired size, which grains are dried and hardened by steeping in a suitable solvent for the nitro compound, and after finally drying, sifting, &c., the powder is stored in magazines for several months before it is issued. When issued, a very large blend is made of many tons weight, which ensures absolute uniformity in the material. There is in England a standard load adopted by every one for testing a sporting powder; this charge is 42 grains of powder and 1-1/8 oz. No. 6 shot--this shot fired from a 12-bore gun, patterns being taken at 40 yards, the velocity at any required distance. The standard muzzle velocity of Schultze gunpowder is 1,220 feet per second. The mean 40 yards ditto is 875 feet per second. The mean 20 yards ditto is 1,050 feet per second. The internal pressure not to exceed 3.5 tons. This Company also manufactures a new form of powder, known as Imperial Schultze. It is a powder somewhat lighter in gravity; 33 grains occupies the bulk charge, as compared with the 42 grains of the old. It follows in its composition much the lines of the older powder, but it is quite free from smoke, and leaves no residue whatever. ~The E.G. Powder.~--This is one of the oldest of the nitro powders. It was invented by Reid and Johnson in 1882. It is now manufactured by the E.G. Powder Company Limited, at their factory near Dartford, Kent, and in America by the Anglo-American E.G. Powder Company, at New Jersey. The basis of this powder is a fine form of cellulose, derived from cotton, carefully purified, and freed from all foreign substances, and carefully nitrated. Its manufacture is somewhat as follows:--Pure nitro-cotton, in the form of a fine powder, is rotated in a drum, sprinkled with water, and the drum rotated until the nitro-cotton has taken the form of grains. The grains are then dried and moistened with ether-alcohol, whereby the moisture is gelatinised, and afterwards coloured with aurine, which gives them an orange colour. They are then dried and put through a sieve, in order to separate the grains which may have stuck together during the gelatinising process. Since its introduction soon after 1881, E.G. powder has undergone considerable modifications, and is now a distinctly different product from a practical point of view. It is now and has been since 1897 what is known as a 33-grain powder, that is to say, the old standard charge of 3 drams by measure for a 12-bore gun weighs 33 grains, as compared with 42 grains for the original E.G. and other nitro powders. This improvement was effected by a reduction of the barium nitrate and the use of nitro- cellulose of a higher degree of nitration, and also more gelatinisation in manufacture. The granules are very hard, and resist moisture to an extent hitherto unattainable by any "bulk" powder. Irregularities of pressure in loading have also a minimum effect by reason of the hardness of the grains. The colouring matter used is aurine, and the small quantity of nitrate used is the barium salt. The powder is standardised for pressure velocity with Boulengé chronograph,[A] pattern and gravimetric density by elaborate daily tests, and is continually subjected to severe trials for stability under various conditions of storage, the result being that it may be kept for what in practice amount to indefinite periods of time, either in cartridges or in bulk without any alteration being feared. The E.C. powders are used in sporting guns. No. 1 and No. 2 E.C. are not at present manufactured, E.C. No. 3 having taken their place entirely. Since 1890 these powders have been manufactured under the Borland-Johnson patents, these improved powders being for some time known as the J.B. powders. The E.C. No. 1 was superseded by the E.C. No. 2, made under the Borland-Johnson patents, and this in its turn by the E.C. No. 3 (in 1897). [Footnote A: Invented in 1869 by Major Le Boulengé, Belgian Artillery. It is intended to record the mean velocity between any two points, and from its simplicity and accuracy is largely employed. Other forms have been invented by Capt. Bréger, French Artillerie de la Marine, and Capt. Holden, R.A.] ~Indurite~ is the invention of Professor C.E. Munroe, of the U.S. Naval Torpedo Station. It is made from insoluble nitro-cotton, treated in a particular manner by steam, and mixed with nitro-benzene. The _Dupont_ powder is very similar to _Indurite_. M.E. Leonard, of the United States, invented a powder consisting of 75 parts of nitro-glycerine, 25 parts of gun-cotton, 5 parts of lycopodium powder, and 4 parts of urea crystals dissolved in acetone. The French smokeless powder, Vielle poudre (poudre B), used in the Lebel rifle, is a mixture of nitro-cellulose and tannin, mixed with barium and potassium nitrates. It gives a very feeble report, and very little bluish smoke. The Nobel Company is said to be perfecting a smokeless powder in which the chief ingredients are nitro-amido- and tri- nitro-benzene. C.O. Lundholm has patented (U.S. Pat, 701,591, 1901) a smokeless powder containing nitro-glycerine 30, nitro-cellulose 60, diamyl phthalate 10 (or diamyl phthalate 5, and mineral jelly 5). The diamyl phthalate is added, with or without the mineral jelly to nitro-glycerine and nitro-cellulose. ~Walsrode Powder.~--The smokeless powder known as Walsrode powder consists of absolutely pure gelatinised nitro-cellulose, grained by a chemical not a mechanical process, consequently the grains do not need facing with gelatine to prevent their breaking up, as is the case with many nitro powders. For this same reason, as well as from the method of getting rid of the solvent used, the Walsrode has no tendency whatever to absorb moisture. In fact, it can lie in water for several days, and when taken out and dried again at a moderate temperature will be found as good as before. Nor is it influenced by heat, whether dry or damp, and it can be stored for years without being in the least affected. It is claimed also that it heats the barrels of guns much less than black powder, and does not injure them. The standard charge is 30 grains, and it is claimed that with this charge Walsrode powder will prove second to none. A large cap is necessary, as the grains of this powder are very hard, and require a large flame to properly ignite them. In loading cartridges for sporting purposes, an extra felt wad is required to compensate for the small space occupied by the charge; but for military use the powder can be left quite loose. The gas pressure of this powder is low (in several military rifles only one- half that of other nitros), and the recoil consequently small; and it is claimed that with the slight increase of the charge (from 29 to 30 grs.) both penetration and initial velocity will be largely increased, whilst the gas pressure and recoil will not be greater. This powder was used at Bisley, at the National Rifle Association's Meeting, with satisfactory results. It is made by the Walsrode Smokeless and Waterproof Gunpowder Company. The nitro-cotton is gelatinised by means of acetic ether, and the skin produced retards burning. The nitro-cotton is mixed with acetic ether, and when the gelatinisation has taken place, the plastic mass is forced through holes in a metal plate into strips, which are then cut up into pieces the size of grains. The M.H. Walsrode powder is a leaflet powder, light in colour, about 40 grains of which give a muzzle velocity of 1,350 feet and a pressure of 3 tons. It is, like the other Walsrode powders, waterproof and heat-proof. ~Cooppal Powder~ is manufactured by Messrs Cooppal & Co. at their extensive powder works in Belgium. It consists of nitro-jute or nitro- cotton, with or without nitrates, treated with a solvent to form a gelatinised mass. There are a great many varieties of this powder. One kind is in the form of little squares; another, for use in Hotchkiss guns, is formed into 3-millimetre cubes, and is black. Other varieties are coloured with aniline dyes of different colours. ~Amberite~ is a nitro-cellulose powder of the 42-grain type of sporting gunpowders, and is manufactured by Messrs Curtis's & Harvey Limited, at their Smokeless Powder Factory, Tonbridge, Kent. It consists of a mixture of nitro-cellulose, paraffin, barium, nitrate, and some other ingredients. It is claimed for this powder that it combines hard shooting with safety, great penetration, and moderate strain on the gun. It is hard and tough in grain, and may be loaded like black powder, and subjected to hard friction without breaking into powder, that it is smokeless, and leaves no residue in the gun. The charge for 12 bores is 42 grains by weight, and 1-1/8 oz. or 1-1/16 oz. shot. The powders known as cannonite[A] and ruby powder, also manufactured by Messrs Curtis's & Harvey Limited, are analogous products having the same general characteristics. [Footnote A: For further details of cannonite, see First Edition, p. 181.] ~Smokeless Diamond~, also manufactured by the above mentioned firm, is a nitro-cellulose powder of the 33-grain type of sporting gunpowders. It was invented by Mr H.M. Chapman. The manufacture of Smokeless Diamond, as carried out at Tonbridge, is shortly as follows:--The gun-cotton, which is the chief ingredient of this powder, is first stoved, then mixed with certain compounds which act as moderators, and after the solvents are added, is worked up into a homogeneous plastic condition. It then undergoes the processes of granulation, sifting, dusting, drying, and glazing. In order to ensure uniformity several batches are blended together, and stored for some time before being issued for use. It is claimed for this powder that it is quick of ignition, the quickness being probably due to the peculiar structure of the grains which, when looked at under the microscope, have the appearance of coke. The charge for a 12 bore is 33 grains and 1-1/16 oz. shot, which gives a velocity of 1,050 feet per second, and a pressure of 3 tons per square inch. ~Greiner's Powder~ consists of nitro-cellulose, nitro-benzol, graphite, and lampblack. ~B.N. Powder.~--This powder is of a light grey or drab colour, perfectly opaque, and rough to the touch. It consists of a mixture, nitro-cellulose and the nitrates of barium and potassium. Its composition is as follows:-- Insoluble nitro-cellulose 29.13 parts Soluble nitro-cellulose 41.31 " Barium nitrate 19.00 " Potassium nitrate 7.97 " Sodium carbonate 2.03 " Volatile matter 1.43 " This powder is a modification of the Poudre B., or Vieille's powder invented for use in the Lebel rifle, and which consisted of a mixture of the nitro-celluloses with paraffin. ~Von Foster's Powder~ contains nothing but pure gelatinised nitro- cellulose, together with a small quantity of carbonate of lime. The German ~Troisdorf Powder~ is a mixture of gelatinised nitro-cellulose, with or without nitrates. ~Maximite~ is the invention of Mr Hudson Maxim, and is a nitro-compound, the base being gun-cotton. The exact composition and method of manufacture are, however, kept secret. It is made by the Columbia Powder Manufacturing Company, of New York, and in two forms--one for use as a smokeless rifle powder, and the other for blasting purposes. ~Wetteren Powder.~--This powder was manufactured at the Royal Gunpowder Factory at Wetteren, and used in the Belgian service. Originally it was a mixture of nitro-glycerine and nitro-cellulose, with amyl acetate as solvent. Its composition has, however, been altered from time to time. One variety consists chiefly of nitro-cellulose, with amyl acetate as solvent. It is of a dark brown colour, and of the consistency of indiarubber. It is rolled into sheets and finally granulated. ~Henrite~ is a nitro-cellulose powder. ~Normal Powder.~--The Swedish powder known as "Normal" Smokeless Powder, and manufactured by the Swedish Powder Manufacturing Company, of Landskrona, Sweden, and used for some years past in the Swiss Army, is made in four forms. For field guns of 8.4 calibre, it is used in the form of cylindrical grains of a yellow colour, of a diameter of .8 to .9 mm. and density of .790--about 840 grains of it go to one gun. For rifles, it is used in the form of grey squares, density .750, and 1 grm. equals about 1,014 grains. One hundred rounds of this powder, fired in eighteen minutes, raised the temperature of the gun barrel 284° F. A nitro- glycerine powder, fired under the same conditions, gave a temperature of 464° F. This powder is said to keep well--a sample kept 3-1/2 years gave as good results as when first made--is easy to make, very stable, ignites easily, not very sensitive to shock or friction, is very light, &c. Eight hundred rounds fired from a heavy gun produced no injury to the interior of the weapon. Samples kept for eleven months in the moist atmosphere of a cellar, when fired gave a muzzle velocity of 1,450 ft. secs. and pressure of 1,312 atmospheres, and the moisture was found to have risen from 1.2 to 1.6 per cent. After twenty-three months in the damp it contained 2 per cent. moisture, gave a muzzle velocity of 1,478 ft. sees., and pressure of 1,356 atmospheres. In a 7.5 millimetre rifle, 13.8 grm. bullet, and charge of 2 grms., it gives a muzzle velocity of 2,035 ft. secs. and a pressure of 2,200 atmospheres. In the 8.4 cm. field-gun, with charge of 600 grms., and projectile of 6.7 kilogrammes, muzzle velocity was equal to 1,640 ft. secs. and pressure 1,750. A sample of the powder for use in the .303 M. rifle, lately analysed by the author, gave the following result:-- Gun-cotton 96.21 per cent. Soluble cotton 1.80 " Non-nitrated cotton trace. Resin and other matters 1.99 " _______ 100.00 The various forms of powder invented and manufactured by Mr C.F. Hengst are chiefly composed of nitrated straw that has been finely pulped. The straw is treated first with acids and afterwards with alkalies, and the result is a firm fibrous substance which is granulated. It is claimed that this powder is entirely smokeless and flameless, that it does not foul the gun nor heat the barrel, and is at the same time 150 per cent. stronger than black powder. The German "Troisdorf" powder consists of nitro-cellulose that has been gelatinised together with a nitrate. Kolf's powder is also gelatinised with nitro-cellulose. The powders invented by Mr E.J. Ryves contain nitro- glycerine, nitro-cotton, castor-oil, paper-pulp, and carbonate of magnesia. Maxim powder contains both soluble and insoluble nitro- cellulose, nitro-glycerine, and carbonate of soda. The smokeless powder made by the "Dynamite Actiengesellschaft Nobel" consists of nitro-starch 70 to 99 parts, and of di- or tri-nitro-benzene 1 to 30 parts. An American wood powder, known as Bracket's Sporting Powder, consists of soluble and insoluble nitro-lignine, mixed with charred lignine, humus, and nitrate of soda. Mr F.H. Snyder, of New York, is the inventor of a shell powder known as the "Snyder Explosive," consisting of 94 per cent. nitro-glycerine, 6 per cent. of soluble nitro-cotton, and camphor, which is said to be safe in use. Experiments were made with it in a 6-inch rifled gun, fired at a target 220 yards away, composed of twelve 1-inch steel plates welded together, and backed with 12-inch and 14-inch oak beams, and weighing 20 tons. The shots entirely destroyed it. The charge of explosive used was 10 lbs. in each shell. ~Comparative Tests of Black and Nitro Powders, from "American Field."~-- The results given in table below were obtained at the German Shooting Association's grounds at Coepenick, Berlin. Penetration was calculated by placing frames, each holding five cards of 1 millimetre in thickness (equals .03937 inch), and 3 inches apart, in a bee-line, at distances of 20 inches. Velocity, pattern, and penetration were taken at 40 yards from the muzzle of a 12-gauge choke-bore double-barrel gun. Gas pressure was taken by a special apparatus. All shells were loaded with 1-1/8 oz. of No. 3 shot, equal to 120 pellets, and the number given below represents the average number in the 30-inch pattern. The number of sheets passed through gives the average penetration. One atmosphere equals pressure equal to 1 kilogramme (2.2 lbs.) on the square centimetre, hence 1,000 atmospheres equal 2,200 lbs. on the square centimetre. The E.C., Schultze, and Walsrode powders were loaded in Elcy's special shells, 2-1/2 inches long. The averages were taken from a large number of shots, and the same series of shots fired under precisely the same conditions. _______________________________________________________________________ | | | | | | | | Gas | | | | | | Pressure. | Velocity. | Pattern. | Penetration. | |__________________|____________|___________|____________|______________| | | | | | | | |Atmospheres.| Metres. | | Sheets. | | | | | | | |Fine-grained black| | | | | |powder, standard | | | | | |charge | 514.2 | 280 | 78.6 = 66% | 19.O | | | | | | | |Coarse-grained | | | | | |black powder, | | | | | |standard charge | 473.4 | 281.4 | 78.2 = 65% | 19.4 | | | | | | | |Schultze powder, | | | | | |42 grains | 921.0 | 290.0 | 64.2 = 54% | 20.2 | | | | | | | |Schultze powder, | | | | | |45 grains | 1052.8 | 305.8 | 52.2 = 42% | 20.6 | | | | | | | |E.G. smokeless, | | | | | |42 grains | 920.2 | 298.4 | 81.4 = 67% | 18.8 | | | | | | | |Walsrode, | | | | | |29 grains | 586.4 | 280.6 | 83.0 = 69% | 19.0 | |__________________|____________|___________|____________|______________| Barometer, 760 mm. Thermometer, 30° C. Hydrometer = 65. Wind, S.W. ~Picric Powders.~--The chief of these is _Melinite_, the composition of which is not known with certainty. It is believed to be melted picric acid together with gun-cotton dissolved in acetone or ether-alcohol. Walke gives the following proportions--30 parts of tri-nitro-cellulose dissolved in 45 parts of ether-alcohol (2 to 1), and 70 parts of fused and pulverised picric acid. The ether-alcohol mixture is allowed to evaporate spontaneously, and the resulting cake granulated. The French claim, however, that the original invention has been so modified and perfected that the melinite of to-day cannot be recognised in the earlier product. Melinite has a yellow colour, is almost without crystalline appearance, and when ignited by a flame or heated wire, it burns with a reddish-yellow flame, giving off copious volumes of black smoke. Melinite as at present used is said to be a perfectly safe explosive, both as regards manufacture, handling, and storage. _Lyddite_,[A] the picric acid explosive used in the British service, is supposed to be identical with the original melinite, but its composition has not been made public. [Footnote A: Schimose, the Japanese powder, is stated to be identical with Lyddite and Melinite (_Chem. Centr._, 1906, 1, 1196).] Picrates are more often used than picric acid itself in powders. One of the best known is _Brugère's Powder_, which is a mixture of 54 parts of picrate of ammonia and 45 parts of saltpetre. It is stable and safe to manufacture. It has been used in the Chassepôt rifle with good results, gives little smoke, and a small residue only of carbonate of potash. The next in importance is _Designolle's Powder_, made at Bouchon, consisting of picrate of potash, saltpetre, and charcoal. It was made in three varieties, viz., for rifles, big guns, and torpedoes and shells. These powders are made much in the same way as gunpowder. The advantages claimed for them over gunpowder are, greater strength, comparative absence of smoke, and freedom from injurious action on the bores of guns. _Emmensite_ is the invention of Dr Stephen Emmens, of the United States. The Emmens "crystals" are produced by treating picric acid with fuming nitric acid of specific gravity of 1.52. The acid dissolves with the evolution of red fumes. The liquid, when cooled, deposits crystals, stated to be different to picric acid, and lustrous flakes. These flakes, when heated in water, separate into two new bodies. One of these enters into solution and forms crystals unlike the first, while the other body remains undissolved. The acid crystals are used mixed with a nitrate. Emmensite has been subjected to experiment by the direction of the U.S. Secretary for War, and found satisfactory. A sample of Emmensite, in the form of a coarse powder, was first tried in a pistol, and proved superior in propelling power to ordinary gunpowder. When tested against explosive gelatine, it did very good work in shattering iron plates. It is claimed for this explosive that it enjoys the distinction of being the only high explosive which may be used both for firearms and blasting. This view is supported by the trials made by the American War Office authorities, and shows Emmensite to be a useful explosive both for blasting and as a smokeless powder. Its explosive power, as tested, is 283 tons per square inch, and its specific gravity is 1.8. Abel proposed to use picric acid for filling shells. His _Picric Powder_ consisted of 3 parts of saltpetre, and 2 of picrate of ammonia. _Victorite_ consists of chlorate of potash, picric acid, and olive oil, and with occasionally some charcoal. It has the form of a coarse yellowish grey powder, and leaves an oily stain on paper, and it is very sensitive to friction and percussion. The composition is as follows:--KClO_{3} = 80 parts; picric acid, 110 parts; saltpetre, 10 parts; charcoal, 5 parts. It is not manufactured in England. _Tschiner's Powder_ is very similar to Victorite in composition, but contains resin. A list of the chief picric powders will be found in the late Colonel J.P. Cundill, R.A.'s "Dictionary of Explosives." CHAPTER VII. _ANALYSIS OF EXPLOSIVES._ Kieselguhr Dynamite--Gelatine Compounds--Tonite--Cordite--Vaseline-- Acetone--Scheme for Analysis of Explosives--Nitro-Cotton--Solubility Test-- Non-Nitrated Cotton--Alkalinity--Ash and Inorganic Matter--Determination of Nitrogen--Lungé, Champion and Pellet's, Schultze-Tieman, and Kjeldahl's Methods--Celluloid--Picric Acid and Picrates--Resinous and Tarry Matters-- Sulphuric Acid and Hydrochloric Acid and Oxalic Acid--Nitric Acid-- Inorganic Impurities--General Impurities and Adulterations--Potassium Picrate, &c.--Picrates of the Alkaloids--Analysis of Glycerine--Residue-- Silver Test--Nitration--Total Acid Equivalent--Neutrality--Free Fatty Acids--Combined Fatty Acids--Impurities--Oleic Acid--Sodium Chloride-- Determination of Glycerine--Waste Acids--Sodium Nitrate--Mercury Fulminate--Cap Composition--Table for Correction of Volumes of Gases, for Temperature and Pressure ~Kieselguhr Dynamite.~--The material generally consists of 75 per cent. of nitro-glycerine and 25 per cent. of the infusorial earth kieselguhr. The analysis is very simple, and may be conducted as follows:--Weigh out about 10 grms. of the substance, and place over calcium chloride in a desiccator for some six to eight days, and then re-weigh. The loss of weight gives the moisture. This will generally be very small, probably never more than 1 per cent., and usually less. Mr James O. Handy, in order to save time, proposes to dry dynamite in the following manner. He places 1 grm. of the material in a porcelain crucible 1 inch in diameter. The crucible is then supported at the bottom of an extra wide-mouthed bottle of about 600 c.c. capacity. Air, which has been dried by bubbling through strong sulphuric acid, is now drawn over the surface of the sample for three hours by means of an ordinary aspirator. The air should pass approximately at the rate of 10 c.c. per second. The tube by which the dry air enters the bottle extends to within 1 inch of the crucible containing the dynamite. An empty safety bottle is connected with the inlet, and another with the outlet of the wide-mouthed bottle. The first guards against the mechanical carrying over by the air current of sulphuric acid from the acid bottle into the sample, whilst the second prevents spasmodic outbursts of water from the exhaust from reaching the sample. The method also gave satisfactory results with nitro-glycerine. The dry substance may now be wrapped in filter paper, the whole weighed, and the nitro-glycerine extracted in the Soxhlet apparatus with ether. The ether should be distilled over at least twenty-four times. I have found, however, that much quicker, and quite as accurate, results may be obtained by leaving the dynamite in contact with ether in a small Erlenmeyer flask for twenty-four hours--leaving it overnight is better-- and decanting, and again allowing the substance to remain in contact with a little fresh ether for an hour, and finally filtering through a weighed filter, drying at 100° C., and weighing. This gives the weight of the kieselguhr. The nitro-glycerine must be obtained by difference, as it is quite useless to evaporate down the ethereal solution to obtain it, as it is itself volatile to a very considerable extent at the temperature of evaporation of the ether, and the result, therefore, will always be much too low. The dry guhr can, of course, be examined, either qualitatively or quantitatively, for other mineral salts, such as carbonate of soda, &c. An actual analysis of dynamite No. 1 made by the author at Hayle gave-- Moisture, 0.92 per cent.; kieselguhr, 26.15 per cent.; and nitro- glycerine, 72.93 per cent., the last being obtained by difference. ~Nitro-Glycerine.~--It is sometimes desired to test an explosive substance for nitro-glycerine. If an oily liquid is oozing from the substance, soak a drop of it in filter paper. If it is nitro-glycerine it will make a greasy spot. If the paper is now placed upon an iron anvil, and struck with an iron hammer, it will explode with a sharp report, if lighted it burns with a yellowish to greenish flame, emitting a crackling sound, and placed upon an iron plate and heated from beneath, it explodes sharply. If a few drops of nitro-glycerine are placed in a test tube, and shaken up with methyl-alcohol (previously tested with distilled water, to see that it produces no turbidity), and filtered, on the addition of distilled water, the solution will become milky, and the nitro-glycerine will separate out, and finally collect at the bottom of the tube. If to a solution of a trace of nitro-glycerine in methyl-alcohol, a few drops of a solution, composed of 1 volume of aniline, and 40 volumes sulphuric acid (1.84) be added, a deep purple colour will be produced. This colour changes to green upon the addition of water. If it is necessary to determine the nitro-glycerine quantitatively in an explosive, the scheme on page 213 may be followed. Ether is the best solvent to use. Nitrogen should be determined in the nitrometer. ~Gelatine Compounds.~--The simplest of these compounds is, of course, blasting gelatine, as it consists of nothing but nitro-cotton and nitro- glycerine, the nitro-cellulose being dissolved in the glycerine to form a clear jelly, the usual proportions being about 92 per cent. of nitro- glycerine to 8 per cent. nitro-cotton, but the cotton is found as high as 10 per cent. in some gelatines. Gelatine dynamite and gelignite are blasting gelatines, with varying proportions of wood-pulp and saltpetre (KNO_{3}) mixed with a thin blasting gelatine. The method of analysis is as follows:--Weigh out 10 grms. of the substance, previously cut up into small pieces with a platinum spatula, and place over calcium chloride in a desiccator for some days. Reweigh. The loss equals moisture. This is generally very small. Or Handy's method may be used. The dried sample is then transferred to a small thistle-headed funnel which has been cut off from its stem, and the opening plugged with a little glass wool, and round the top rim of which a piece of fine platinum wire has been fastened, in order that it may afterwards be easily removed from the Soxhlet tube. The weight of this funnel and the glass wool must be accurately known. It is then transferred to the Soxhlet tube and exhausted with ether, which dissolves out the nitro-glycerine. The weighed residue must afterwards be treated in a flask with ether-alcohol to dissolve out the nitro-cotton. But the more expeditious method, and one quite as accurate, is to transfer the dried gelatine to a conical Erlenmeyer flask of about 500 c.c. capacity, and add 250 c.c. of a mixture of ether-alcohol (2 ether to 1 alcohol), and allow to stand overnight. Sometimes a further addition of ether-alcohol is necessary. It is always better to add another 300 c.c., and leave for twenty minutes or so after the solution has been filtered off. The undissolved portion, which consists of wood-pulp, potassium nitrate, and other salts, is filtered off through a linen or paper filter, dried and weighed. ~Solution.~--The ether-alcohol solution contains the nitro-cotton and the nitro-glycerine in solution.[A] To this solution add excess of chloroform (about 100 c.c. will be required), when the nitro-cellulose will be precipitated in a gelatinous form. This should be filtered off through a linen filter, and allowed to drain. It is useless to attempt to use a filter pump, as it generally causes it to set solid. The precipitated cotton should then be redissolved in ether-alcohol, and again precipitated with chloroform (20 c.c. of ether-alcohol should be used). This precaution is absolutely necessary, if the substance has been treated with ether- alcohol at first instead of ether only, otherwise the results will be much too high, owing to the gelatinous precipitate retaining very considerable quantities of nitro-glycerine. The precipitate is then allowed to drain as completely as possible, and finally allowed to dry in the air bath at 40° C., until it is easily detached from the linen filter by the aid of a spatula, and is then transferred to a weighed watch-glass, replaced in the oven, and dried at 40° C. until constant in weight. The weight found, calculated upon the 10 grms. taken, gives the percentage of nitro- cellulose. [Footnote A: If the substance has been treated with ether alone in the Soxhlet, the nitro-glycerine will of course be dissolved out first, and the ether-alcohol solution will only contain the nitro-cellulose.] ~The Residue~ left after treating the gelatine with ether-alcohol is, in the case of blasting gelatine, very small, and will probably consist of nothing but carbonate of soda. It should be dried at 100° C. and weighed, but in the case of either gelignite or gelatine dynamite this residue should be transferred to a beaker and boiled with distilled water, and the water decanted some eight or ten times, and the residue finally transferred to a tarred filter and washed for some time with hot water. The residue left upon the filter is wood-pulp. This is dried at 100° C. until constant, and weighed. The solution and washings from the wood are evaporated down in a platinum dish, and dried at 100° C. It will consist of the potassium nitrate, and any other mineral salts, such as carbonate of soda, which should always be tested for by adding a few drops of nitric acid and a little water to the residue, and again evaporating to dryness and re-weighing. From the difference in weight the soda can be calculated, sodium nitrate having been formed. Thus-- Na_{2}CO_{3} + 2HNO_{3} = 2NaNO_{3} + CO_{2} + H_{2}O. Mol. wt. = 106 = 170 (170 - 106 = 64) and _x_ = (106 x _d_)/64 where _x_ equals grms. of sodium carbonate in residue, and _d_ equals the difference in weight of residue, before and after treatment with nitric acid. The nitro-glycerine is best found by difference, but if desired the solutions from the precipitation of the nitro-cellulose may be evaporated down upon the water bath at 30° to 40° C., and finally dried over CaCl_{2} until no smell of ether or chloroform can be detected, and the nitro- glycerine weighed. It will, however, always be much too low. An actual analysis of a sample of gelatine dynamite gave the following result:-- Nitrocellulose (collodion) 3.819 per cent. Nitro-glycerine 66.691 " Wood-pulp 16.290 " KNO_{3} 12.890 " Na_{2}CO_{3} _Nil._ Water 0.340 " This sample was probably intended to contain 30 per cent. of absorbing material to 70 per cent. of explosive substances. Many dynamites contain other substances than the above, such as paraffin, resin, sulphur, wood, coal-dust, charcoal, also mineral salts, such as carbonate of magnesia, chlorate of potash, &c. In these cases the above-described methods must of course be considerably modified. Paraffin, resin, and most of the sulphur will be found in the ether solution if present. The solution should be evaporated (and in this case the explosive should in the first case be treated with ether only, and not ether-alcohol), and the residue weighed, and then treated on the water bath with a solution of caustic soda. The resin goes into solution, and is separated by decantation from the residue, and precipitated by hydrochloric acid, and collected on a tarred filter (dried at 100° C.), and dried at 100° C. and weighed. The nitro- glycerine residue is treated with strong alcohol, decanted, and the residue of paraffin and sulphur washed with alcohol, dried, and weighed. To separate the paraffin from the sulphur the residue is heated with a solution of ammonium sulphide. After cooling the paraffin collects as a crust upon the surface of the liquid, and by pricking a small hole through it with a glass rod the liquid underneath can be poured off, and the paraffin then washed with water, dried, and weighed. Sulphur is found by difference. Mr F.W. Smith (_Jour. Amer. Chem. Soc._, 1901, 23 [8], 585-589) determines the sulphur in dynamite gelatine as follows:--About 2 grms. are warmed in a 100 c.c. silver crucible on the water bath with an alcoholic solution of sodium hydroxide, and where the nitro-glycerine is decomposed, the liquid is evaporated to dryness. The residue is fused with 40 grms. of KOH and 5 grms. of potassium nitrate, the mass dissolved in dilute acetic acid and filtered, and the sulphates precipitated in the usual way. If camphor is present, it can be extracted with bisulphide of carbon after the material has been treated with ether-alcohol. In that case the sulphur, paraffin, and resin will also be dissolved. The camphor being easily volatile, can be separated by evaporation. Let the weight of the extract, freed from ether-alcohol before treatment with bisulphide of carbon, equal A, and the weight of extract after treatment with CS_{2} and evaporation of the same equal B; and weight of the residue which is left after evaporation of the CS_{2} and the camphor in solution equal C, the percentage of camphor will be A - B - C. The residue C may contain traces of nitro-glycerine, resin, or sulphur. Camphor may be separated from nitro-glycerine by means of CS_{2}. If the solution of camphor in nitro-glycerine be shaken with CS_{2}, the camphor and a little of the nitro-glycerine will dissolve. The bisulphide solution is decanted, or poured into a separating funnel and separated from the nitro-glycerine. The two solutions are then heated on the water bath to 20° C. and then to 60° C., and afterwards in a vacuum over CaCl_{2} until the CS_{2} has evaporated from them. The camphor evaporates, and leaves the small quantity of nitro-glycerine which had been dissolved with it. The other portion is the nitro-glycerine, now free from CS_{2}. The two are weighed and their weights added together, and equals the nitro- glycerine present. There is a loss of nitro-glycerine, it being partly evaporated along with the CS_{2}. Captain Hess has shown that it is equal to about 1.25 per cent. This quantity should therefore be added to that found by analysis. Morton Liebschutz, in a paper in the _Moniteur Scientifique_ for January 1893, very rightly observes that the variety of dynamites manufactured is very great, all of them having a special composition which, good or bad, is sometimes of so complicated a nature that the determination of their elements is difficult. The determination of nitro-glycerine in simple dynamite No. 1 is easy; but not so when the dynamite contains substances soluble in ether, such as sulphur, resin, paraffin, and naphthalene. After detailing at length the methods he employs, he concludes with the observation that the knowledge of the use of acetic acid--in which nitro-glycerine dissolves--for the determination of nitro-glycerine may be serviceable. Mr F.W. Smith[A] gives the following indirect method of determining nitro-glycerine in gelatine dynamite, &c. About 15 grms. of the sample are extracted with chloroform in a Soxhlet apparatus, and the loss in weight determined. In a second portion the moisture is determined. A third portion of about 2 grms. is macerated with ether in a small beaker, the ethereal extract filtered, and the process of extraction repeated three or four times. The united filtrates are allowed to evaporate spontaneously, and the residue warmed gently on the water bath with 5 c.c. of ammonium sulphide solution, and 10 c.c. of alcohol until the nitro-glycerine is decomposed, after which about 250 c.c. of water and sufficient hydrochloric acid to render the liquid strongly acid, are added, and the liquid filtered. The precipitate is washed free from acid, and then washed through the filter with strong alcohol and chloroform into a weighed platinum dish, which is dried to constant weight at 50° C. The contents of the dish are now transferred to a silver crucible, and the sulphur determined. This amount of sulphur, deducted from the weight of the contents of the platinum dish, gives the quantity of substances soluble in chloroform with the exception of the nitro-glycerine, moisture, and sulphur. The amount of the former substances _plus_ the moisture and sulphur, deducted from the total loss on extraction with chloroform, gives the quantity of nitro-glycerine. Nitro-benzene may be detected, according to J. Marpurgo, in the following manner:--In a porcelain basin are placed two drops of liquid phenol, three drops of water, and a fragment of potash as large as a pea. The mixture is boiled, and the aqueous solution to be tested then added. On prolonged boiling nitro-benzene produces at the edge of the liquid a crimson ring, which on the addition of a solution of bleaching powder turns emerald- green. And nitro-glycerine in ether solution, by placing a few drops of the suspected solution, together with a drop or two of aniline, upon a watch-glass, evaporating off the ether, and then adding a drop of concentrated sulphuric acid to the residue, when, if nitro-glycerine is present, the H_{2}SO_{4} will strike a crimson colour, due to the action of the aniline sulphate upon the nitric acid liberated from the nitro- glycerine. [Footnote A: "Notes on the Analysis of Explosives," _Jour. Amer. Chem. Soc._, 1901, 23 [8], 585-589.] ~Tonite.~--The analysis of this explosive is a comparatively easy matter, and can be performed as follows:--Weigh out 10 grms., or a smaller quantity, and boil with water in a beaker, decanting the liquid four or five times, and filter. The aqueous solution will contain the nitrate of barium. Then put the residue on the filter, and wash two or three times with boiling water. Evaporate the filtrate to dryness in a platinum dish. Dry and weigh. This equals the Ba(NO_{3})_{2}. If the sample is tonite No. 3, and contains di-nitro-benzol, treat first with ether to dissolve out this substance. Filter into a dish, and evaporate off the ether, and weigh the di-nitro-benzol, and afterwards treat residue with water as before. The residue is dried and weighed, and equals the gun-cotton present. It should then be treated with a solution of ether-alcohol in a conical flask, allowed to stand some three hours, then filtered through a weighed filter paper, dried at 40° C., and weighed. This will give the gun-cotton, and the difference between this last weight and the previous one will give the collodion-cotton. A portion of the residue containing both the gun- cotton and the soluble cotton can be tested in the nitrometer, and the nitrogen determined. ~Cordite.~--This explosive consists of gun-cotton (with a little collodion-cotton in it as impurity), nitro-glycerine, and vaseline--the proportions being given as 30 per cent. nitro-glycerine, 65 per cent. gun- cotton, and 5 per cent. vaseline. Its analysis is performed by a modification of the method given for gelatines. Five grms. may be dissolved in ether-alcohol in a conical flask, allowed to stand all night, and then filtered through a linen filter. The residue is washed with a little ether, pressed, and dried at 40° C., and weighed. It equals the gun-cotton. The solution contains the nitro-glycerine, soluble cotton, and vaseline. The cotton is precipitated with chloroform, filtered off, dried, and weighed. The two ether-alcohol solutions are mixed, and carefully evaporated down in a platinum dish upon the water bath at a low temperature. The residue is afterwards treated with strong 80 per cent. acetic acid, which dissolves out any nitro-glycerine left in it. The nitro-glycerine is then obtained by difference, or the method suggested to me privately by Mr W.J. Williams may be used. The residue obtained by evaporation of the ether-alcohol solution, after weighing, is treated with alcoholic potash to decompose the nitro-glycerine, water is added and the alcohol evaporated off. Some ether is then added, and the mixture shaken, and the ether separated and evaporated, and the residue weighed as vaseline. The moisture should, however, be determined by the method devised by Mr Arthur Marshall, F.I.C., of the Royal Gunpowder Works, Waltham Abbey, which is carried out as follows:--The cordite or other explosive is prepared in the manner laid down for the Abel heat test, that is t say, it is ground in a small mill, and that portion is selected which passes through a sieve having holes of the size of No. 8 wire gauge, but not through one with holes No. 14 wire gauge. [Illustration: FIG. 40.--MARSHALL'S APPARATUS FOR MOISTURE IN CORDITE.] The form of apparatus used is shown in Fig. 40. It consists of an aluminium dish A, having the dimensions shown, and the glass cone B weighing not more than 30 grms. Five grms. of the cordite are weighed into the aluminium dish A. This is covered with the cone B, and the whole is accurately weighed, and is then placed upon a metal plate heated by steam from a water bath. It is left upon the bath until all the moisture has been driven off, then it is allowed to cool for about half-an-hour in a desiccator and is weighed. The loss in weight gives accurately the moisture of the sample. For cordite of the original composition, one hour's heating is sufficient to entirely drive off the moisture; for modified cordite containing 65 per cent. of gun-cotton, two hours is enough, provided that there be not more than 1.3 per cent. of moisture present. If the proportion of nitro-glycerine be higher, a longer heating is necessary. The aluminium dish must not be shallower than shown in the figure, for if the distance between the substance and the edge of the glass cone be less than half an inch, some nitro-glycerine will be lost. Again, the sample must not be ground finer than stated, else some of the moisture will be lost in the grinding and sieving operations, and the result will be too low. In order to be able to drive off all the moisture in the times mentioned, it is essential that the glass cone shall not fit too closely on the aluminium dish, consequently the horizontal ledge round the top of the dish should be bent, so as to render it slightly untrue, and leave a clearance of about 0.02 inch in some places. If these few simple precautions be taken, the method will be found to be very accurate. Duplicate determinations do not differ more than 0.01 per cent.[A] [Footnote A: "Determination of Moisture in Nitro-glycerine Explosives," by A. Marshall, _Jour. Soc. Chem. Ind._, Feb. 29, 1904, p. 154.] ~The Vaseline~ (C_{16}H_{34}), or petroleum jelly, used has a flash-point of 400° F. It must not contain more than 0.2 per cent. volatile matter when heated for 12 hours on the water bath, and should have a specific gravity of 0.87 at 100° F., and a melting point of 86° F. It is obtained during the distillation of petroleum, and consists mainly of the portions distilling above 200° C. It boils at about 278° C. ~Acetone~ (CH_{3}CO.CH_{3}), or dimethyl ketone, is formed when iso-propyl alcohol is oxidised with potassium bichromate and sulphuric. It is also produced in considerable quantities during the dry distillation of wood, and many other organic compounds. Crude wood spirit, which has been freed from acetic acid, consists in the main of a mixture of acetone and methyl- alcohol. The two substances may be roughly separated by the addition of calcium chloride, which combines with the methyl-alcohol. On subsequent distillation crude acetone passes over, and may be purified by conversion into the bisulphite compound. Acetone is usually prepared, however, by the dry distillation of crude calcium or barium acetate. (CH_{3}.COO)_{2}Ca = CH_{3}.CO.CH_{3} + CaCO_{3}. The distillate is fractionated, and the portion, boiling between 50° and 60° C., mixed with strong solution of sodium bisulphite. The crystalline cake of acetone sodium bisulphite, which separates on standing, is well pressed, to free it from impurities, decomposed by distillation with dilute sodium carbonate, and the aqueous distillate of pure acetone dehydrated over calcium chloride. Acetone is a colourless, mobile liquid of sp. gr. .792 at 20° C., it boils at 56.5° C., has a peculiar, pleasant, ethereal odour, and is mixible with water, alcohol, and ether in all proportions. The acetone used in the manufacture of cordite should conform to the following specification:-- SPECIFICATION FOR ACETONE. 1. The acetone to be not more than 0.802 specific gravity at 60° F. When mixed with distilled water it must show no turbidity, and must leave no residue on evaporation at 212° F. On distillation, four-fifths by volume of the quantity taken must distil over at a temperature not exceeding 138° F. The residual matter left after this distillation must not contain, besides acetone, any ingredient that is not a bye-product incidental to the manufacture of acetone. 2. One c.c. of 0.10 per cent. solution in distilled water of pure permanganate of potash, added to 100 c.c. of the acetone, must retain its distinctive colour for not less than 30 minutes. This test should be made at a temperature of 60° F. 3. The acetone tested by the following method must not show more than 0.005 per cent. of acid, calculated to acetic acid:-- To 50 c.c. of the sample diluted with 50 c.c. of distilled water, with 2 c.c. of phenol-phthalein solution (1 gramme to 1,000 c.c. of 50 per cent. alcohol) added as an indicator, add from a burette N/100 sodium hydrate solution (1 c.c. 0.0006 gramme acetic acid), and calculate to acetic acid in the usual manner. The water used for the dilution of the acetone must be carefully tested for acidity, and the pipettes used for measuring should not be blown out, as it would be possible thus to neutralise nearly 2 c.c. of the soda solution. The presence of water in a sample of acetone may be detected by Schweitzer and Lungwitz's method (_Chem. Zeit._, 1895, xix., p. 1384), which consists in shaking together equal volumes of acetone and petroleum ether (boiling point, 40° to 60° C.), when if present a separation of the liquid in layers will take place. ~Estimation of Acetone.~--Kebler (_Jour. Amer. Chem. Soc._, 1897, 19, 316- 320) has improved Squibb's modification of Robineau and Rollins' method. The following solutions are required:-- (1.) A 6 per cent. solution of hydrochloric acid. (2.) A decinormal solution of sodium thiosulphate. (3.) Alkaline potassium iodide solution prepared by dissolving 250 grms. of potassium iodide in water, made up to a litre; dissolving 257 grms. of sodium hydroxide (by alcohol) in water, likewise made up to a litre. After allowing the latter to stand, 800 c.c. of the clear solution are added to the litre of KI. (4.) Sodium hypochlorite solution: 100 grms. of bleaching powder (35 per cent.) are mixed with 400 c.c. of water: to this is added a hot solution of 120 grms. of crystallised sodium carbonate in 400 c.c. of water. After cooling, the clear liquid is decanted, the remainder filtered, and the filtrate made up to a litre; to each litre is added 25 c.c. of sodium hydroxide solution (sp. gr. 1.29). (5.) An aqueous solution of the acetone, containing 1 or 2 per cent. of acetone. (6.) Bicarbonated starch solution prepared by treating 0.125 grm. of starch with 5 c.c. of cold water, then adding 20 c.c. of boiling water, boiling a few minutes, cooling, and adding 2 grms. of sodium bicarbonate. To 20 c.c. of the potassium iodide solution are added 10 c.c. of the diluted aqueous acetone, an excess of the sodium hypochlorite solution is then run in from a burette and well shaken for a minute. The mixture is then acidified with the hydrochloric acid solution, and while agitated, an excess of sodium thiosulphate solution is added, the mixture being afterwards allowed to stand a few minutes. The starch indicator is then added, and the excess of thiosulphate re-titrated. The relation of the sodium hypochlorite solution to the sodium thiosulphate being known, the percentage of acetone can be readily calculated.[A] [Footnote A: See "The Testing of Acetone," Conroy, _Jour. Soc. Chem. Ind._, 31st March 1900, vol. xix.] Dr S.J.M. Auld has recently (_Jour. Chem. Soc._, Feb. 15, 1906, vol. xxv.) worked out a volumetric method for the estimation of acetone, depending on the formation of bromoform, and its subsequent hydrolysis with alcoholic potash. The hydrolysis is probably expressed thus-- 3CHBr_{3} + 9KOH + C_{2}H_{5}OH = 3CO + C_{2}H_{4} + 9KBr + 7H_{2}O as it has been shown by Hermann and Long that exactly 3 volumes of carbon monoxide to 1 of ethylene are evolved. The residual potassium bromide is estimated by means of standard silver nitrate solution. Bromoform is specially suitable for this purpose for several reasons. It is very readily formed by the action of bromine and potash on acetone, and although very volatile in steam, it is not liable to loss due to its own evaporation. Further, its high molecular weight and large percentage of bromine conduce to accurate results, 58 grms. of acetone being responsible for the formation of 357 grms. of KBr. The method of carrying out the analysis is as follows:-- A known quantity of the solution to be tested, containing acetone to the extent of 0.1 to 0.2 grm., is pipetted into a 500 c.c. round-bottom flask, diluted with a little water, and mixed with 20 to 30 c.c. of a 10 per cent. solution of caustic potash. The flask is connected with a long reflex condenser, and is also fitted with a dropping funnel containing a solution of bromine in potassium bromide (200 grms. of Br and 250 grms. of KBr to 1 litre of water). The bromine solution is allowed to flow into the mixture until it has acquired a faint yellow tinge, the flask and its contents being then heated on the water bath at about 70° C. for half-an- hour. Bromine solution is added drop by drop until the slight coloration is permanent, excess of bromine being got rid of by boiling for a minute or two with a little more caustic potash. The mixture is then distilled until the distillate is free from bromoform, halogen being tested for in the usual manner. Water is added to the contents of the flask if necessary. It may be here observed that no acetone can be detected in the distillate by means of the mercuric oxide test, and free bromine is also absent. The condenser having been washed out with a little alcohol, in order to remove any traces of bromoform which may have collected, the distillate and washings are mixed with 50 c.c. of alcohol and sufficient solid caustic potash to make an approximately 10 per cent. solution. The mixture is then heated on the water bath under a reflux condenser until the bromoform is completely decomposed. This generally occupies about three-quarters of an hour. The liquid is allowed to cool, evaporated to smaller bulk if necessary, and exactly neutralised with dilute nitric acid. It is then diluted with water to 500 c.c., and an aliquot part titrated with N/10 silver nitrate solution, using potassium chromate as indicator; 240 parts of bromine correspond to 58 parts of acetone. The complete analysis can be performed in one and a half to two hours. It is imperative that the bromine used should be pure, as crude bromine frequently contains bromoform. The method is suitable for the estimation of acetone in wood-spirit, the spirit being diluted to 10 times its volume, and 5 c.c. of this solution employed for the determination. For example-- (1.) Three c.c. of a solution containing 9.61 per cent. acetone gave 1.7850 grm. KBr. Acetone found = 9.66 per cent. (2.) Ten c.c. of a solution containing 0.96 per cent. acetone gave 0.5847 grm. KBr. Acetone found = 0.95 per cent. ~Nitro-Cotton.~--The first thing upon opening a case of wet cotton, or in receiving a sample from the "poacher," that requires to be determined is the percentage of water that it contains. It is best done by weighing out about 1,000 grms. upon a paper tray, which has been previously dried in the oven at 100° C. for some time, and become constant in weight. The trayful of cotton is then placed in a water oven, kept at 100° C., and dried as long as it loses water. The loss gives the percentage of water. It varies from 20 to 30 per cent. as a rule in "wet" cotton. OUTLINE SCHEME FOR THE ANALYSIS OF NITRO-EXPLOSIVES _______________________________________________________________________ | | | Exhaust dried substance with Anhydrous Ether in Soxhlet's Fat | | Extraction Apparatus. | |_______________________________________________________________________| | | | _Solution_--Divide into two parts ~A.~ and ~B.~ | |_______________________________________________________________________| | | | ~A.~ | | | | Allow ether to evaporate spontaneously. Dry residue in vacuo over | | H_{2}SO_{4} and weigh. Equals nitro-glycerine, resin, camphor, and | | paraffin. | | | | The nitro-glycerine in this residue may be decomposed by heating | | with a solution of alcoholic potash. Water may then be added, and the | | alcohol evaporated off on the water bath. From this solution the | | resin may be precipitated by HCl, filtered off, dried, and weighed. | | Solution containing the paraffin is treated with AmS solution and | | heated. On cooling the paraffin separates, and may be separated. | | Residue may be shaken with CS_{2} to remove camphor. | |_______________________________________________________________________| | | | ~B.~ | | | | Add phenol-phthalein and titrate with alcoholic potash, 1 c.c. normal | | KHO = .330 grm. _resin_, and add considerably more KHO. Evaporate, | | dissolve residue in water, shake with ether, and separate. | |_______________________________________________________________________| | | | _Ethereal Solution_ evaporated leaves paraffin. | |_______________________________________________________________________| | | | _Aqueous Solution_-- | | Add bromide, acidify with HCl, separate any resin and precipitate, | | filtrate with BaCl_{2} BaSO_{4} x .1373 = Sulphur. | |_______________________________________________________________________| | | | _Residue_-- | | Dry, weigh, and exhaust with water preferably in Soxhlet. | |_______________________________________________________________________| | | | | _Solution_-- | _Residue_-- | | Contains metallic | Dry, weigh, and agitate an aliquot part with | | nitrates, chlorates, | with H_{2}SO_{4} and Hg in nitrometer. If | | soluble carbonates, | nitro-cellulose is present, treat remainder of | | the sum of which | residue with ether-alcohol. | | (except AmCO_{3}) |________________________________________________| | can be determined by | | | evaporating down at | _Solution_-- | | 100° C. to dryness | Evaporate and weigh. Residue consists of | | and weighing. | soluble nitro-cellulose. | | Nitrates can be |________________________________________________| | determined by | | | | _Residue_-- | | | Dry and weigh and determine hexa-nitro- | | | cellulose in nitrometer, if present. Exhaust | | | remainder with acetic ether. | | |________________________________________________| | | | | | | _Solution_-- | _Residue_-- | | | Hexa-nitro-cellulose | Dry and weigh, ignite | | | (Gun cotton). | and reweigh. Loss = | | | | _Cellulose_. | | | |_________________________| | | | | | | | Residue consists of | | | | sawdust, charcoal, | | | | coal, chalk, guhr, | | | | or mineral matter, &c. | |______________________|______________________|_________________________| NOTE.--Camphor is found by difference. Sulphur is only partially soluble in ether. It is better, therefore, to extract some of the original substance with water, and treat residue with alcoholic KHO. Add bromide, acidify, and precipitate as BaSO. ~The Solubility Test.~--The object of this test is to ascertain, in the case of gun-cotton, the percentage of soluble (penta and lower nitrates) cotton that it contains, or in the case of soluble cotton, the quantity of gun-cotton. The method of procedure is as follows:--Five grms. of the sample which has been previously dried at 100° C., and afterwards exposed to the air for two hours, is transferred to a conical flask, and 250 c.c. ether-alcohol added (2 ether to 1 alcohol). The flask is then corked and allowed to digest, with repeated shaking, for two or three hours. The whole is then transferred to a linen filter, and when the solution has passed through the filter, is washed with a little ether, and pressed in a hand-screw press between folds of filter paper. The sample is then returned to the flask, and the previous treatment repeated, but it will be sufficient for it to digest for one hour the second time. The filter is then again pressed first gently by hand, then in the press, and afterwards opened up and the ether allowed to evaporate. The gun-cotton is then removed from the filter and transferred to a watch-glass, and dried in the water oven at 100° C. When dry it is exposed to the air for two hours and weighed. It equals the amount of gun-cotton and unconverted cotton in the 5 grms. The unconverted cotton must be determined in a separate 5 grms. and deducted. The method of determining the soluble cotton now used in the Government laboratories is as follows:--Fifty grains of the nitro-cotton are dissolved in 150 c.c. of ether-alcohol, and allowed to stand, with frequent shakings, in a 200 c.c. stoppered measure for six hours; 75 c.c. of the clear solution are then drawn off by the aid of a pipette and evaporated in a dish on the water bath, and finally in the water oven at 120° F. (49° C.), until constant in weight. The weight found equals the quantity of soluble cotton in the 75 c.c., which, multiplied by 4, equals the percentage, thus: Suppose that 2.30 grains was the weight found, then (2.3 x 150)/75 = 4.6 in 50 = 9.20 per cent. A method for the determination of soluble nitro-cellulose in gun-cotton and smokeless powder has been published by K.B. Quinan (_Jour. Amer. Chem. Soc._, 23 [4], 258). In this method about 1 grm. of the finely divided dry sample to be analysed is placed in an aluminium cup 1.9 inch in diameter and 4-1/8 inch deep. It is then covered and well stirred with 50 c.c. of alcohol, 100 c.c. of ether are then added, and the mixture is stirred for several minutes. After removing the stirrer, the cup is lightly covered with an aluminium lid, and is then placed in the steel cup of a centrifugal machine, which is gradually got up to a speed of 2,000 revolutions per minute, the total centrifugal force at the position occupied by the cups (which become horizontal when in rapid rotation) is about 450 lbs. They are rotated at the full speed for ten to twelve minutes, and the machine is then gradually stopped. By this time the whole of the insoluble matter will be at the bottom of the cup, and the supernatant solution will be clear. It is drawn off to within a quarter of an inch of the bottom (without disturbing the sediment), with the aid of a pipette. Care must be taken that the solution thus withdrawn is perfectly clear. About 10 to 15 c.c. of colloid solution and a film of insoluble matter remain at the bottom of the cup; these are stirred up well, the stirrer is rinsed with ether-alcohol, about 50 c.c. of fresh ether-alcohol are added; the mixture is again treated in the centrifugal apparatus for about eight minutes; the whole washing process is then repeated until all soluble matter has been removed. This may require about seven or eight (or for samples with much insoluble matter ten or twelve or more) washings, but as the extraction proceeds, the period of rotation may be somewhat reduced. After extraction is completed, the insoluble matter is transferred to a Gooch crucible with the usual asbestos pad, dried at 100° C., and weighed. The residue may, if wished, be dried and weighed in the aluminium cup, but then it cannot be ignited. The whole time for an analysis exclusive of that required for drying, is from one to two hours--average time, 1-1/4 hour. The results are satisfactory both as to accuracy and rapidity. Acetone-soluble nitro-cellulose may be determined by the same method. ~The Unconverted or Non-nitrated Cotton.~--However well the cotton has been nitrated, it is almost certain to contain a small quantity of non- nitrated or unconverted cotton. This can be determined thus:--Five grms. of the sample are boiled with a saturated solution of sodium sulphide, and then allowed to stand for forty-eight hours, and afterwards filtered or decanted, and again boiled with fresh solutions of sulphide, and again filtered, washed first with dilute HCl and then with water, dried, and weighed. The residue is the cellulose that was not nitrated, plus ash, &c. It should be ignited, and the weight of the ash deducted from the previous weight. Acetone, and acetic-ether (ethyl-acetate) may also be used as solvents for the nitro-cellulose. Another process is to boil the gun-cotton, &c., in a solution of sodium stannate made by adding caustic soda to a solution of stannous chloride, until the precipitate first formed is just re-dissolved. This solution dissolves the cellulose nitrates, but does not affect the cellulose. Dr Lungé found the following process more satisfactory in the case of the more highly nitrated products:--The reagent is an alcoholic solution of sodium-ethylate prepared by dissolving 2 to 3 grms. of sodium in 100 c.c. of 95 per cent. alcohol, and mixing the filtered solution with 100 c.c. of acetone. It has no effect upon cellulose, but decomposes nitro-cellulose with the formation of a reddish brown compound, which is soluble in water. In the determination, 5 grms. of gun-cotton are heated to 40° or 50° C. on the water bath with 150 c.c. of the reagent, the liquid being shaken at intervals for twenty to thirty minutes; or the mixture may be allowed to stand for a few hours at the ordinary temperature. The brown-red solution is decanted from the undissolved residue, and the latter washed with alcohol and with water, by decantation, and then on the filter with hot water, to which a little hydrochloric acid is added for the final washings. For ordinary work this cellulose is dried immediately and weighed, but in exact determinations it is washed with alcohol, again treated with 50 c.c. of the reagent, and separated and washed as before. The cellulose thus obtained, gives no trace of gas in the nitrometer, and duplicate determinations agree within 0.1 to 0.2 per cent. when the weight of unchanged cellulose amounts to about 0.2 grm. Gun-cotton, which is completely soluble in acetone, contains only traces of cellulose, and when as much as 0.85 per cent. is present it does not dissolve entirely. This method is not applicable to the determination of cellulose in lower nitrated products, and Dr Lungé attributes this to the fact that these being prepared with less concentrated acid invariably contain oxy-cellulose. ~Alkalinity.~--Five grms. of the air-dried and very finely divided sample are taken from the centre of the slabs or discs, and digested with about 20 c.c. of N/2 hydrochloric acid, and diluted with water to about 250 c.c., and shaken for about fifteen minutes. The liquid is then decanted, and washed with water until the washings no longer give an acid reaction. The solution, together with the washings, are titrated with N/4 sodium carbonate, using litmus as indicator. ~Ash and Inorganic Matter.~--This is best determined by mixing 2 or 3 grms. of the nitro-cotton in a platinum crucible with shavings of paraffin, heating sufficiently to melt the paraffin, and then allowing the contents of the crucible to catch fire and burn away quietly. The temperature is then raised, and the carbonaceous residue incinerated, cooled, weighed, &c., and the percentage of ash calculated. Schjerning proceeds in the following way:--He takes 5 grms. of the nitro-cotton in a large platinum crucible, he then moistens it with a mixture of alcohol and ether, in which paraffin has been dissolved to saturation, and filtered and mixed with one-fourth of its volume of water. Some fragments of solid paraffin are then added, and the ether set on fire. Whilst this is in progress the crucible is kept in an oblique position, and is rotated so that the gun-cotton may absorb the paraffin uniformly. The partially charred residue is now rubbed down with a rounded glass rod, and the crucible is covered and heated for from fifteen to twenty minutes over the blow-pipe, the lid being occasionally removed. The residue is soon converted into ash, which is weighed, and then washed out into a porcelain basin and treated with hydrochloric acid heated to 90° C. The oxide of iron, alumina, lime, and magnesia are thus dissolved, and the silica remains as insoluble residue. The rest of the analysis is conducted according to the well-known methods of separation. The percentage of ash as a whole is generally all that is required. ~Examination of Nitrated Celluloses with Polarised Light.~--Dr G. Lungé (_Jour. Amer. Chem. Soc._, 1901, 23 [8], 527) has formed the following conclusions:--The most highly nitrated products appear blue in polarised light, but those containing between 13.9 and 13.0 per cent. of nitrogen cannot be distinguished from each other by polarisation. As the percentage of nitrogen rises, the blue colour becomes less intense, and here and there grey fibres can be observed, though not in proportion to the increase in the nitrogen. Below 12.4 per cent. of nitrogen, the fibres show a grey lustre, which usually appears yellow when the top light is cut off. Below 10 per cent. of nitrogen, the structure is invariably partially destroyed and no certain observations possible. It is only possible to distinguish with certainty, firstly any unchanged cellulose by its flashing up in variegated (rainbow) colours; and secondly, highly nitrated products (from 12.75 per cent. N upwards), by their flashing up less strongly in blue colours. The purple transition stage in the fibres containing over 11.28 per cent. of N (Chardonnet) was not observed by Dr Lungé. ~Determination of Nitrogen by Lungé Nitrometer.~--The determination of the percentage of nitrogen in a sample of gun-cotton or collodion is perhaps of more value, and affords a better idea of its purity and composition, than any of the foregoing methods of examination, and taken in conjunction with the solubility test, it will generally give the analyst a very fair idea of the composition of his sample. If we regard gun-cotton as the hexa-nitro-cellulose, the theoretical amount of nitrogen required for the formula is 14.14 per cent., and in the same way for collodion-cotton, which consists of the lower nitrates, chiefly, however, of the penta- nitrate, the theoretical nitrogen is 12.75 per cent., so that if in a sample of nitro-cotton the nitrogen falls much lower than 14 per cent., it probably contains considerable quantities of the lower nitrates, and perhaps some non-nitrated cellulose as well (C_{6}H_{10}O_{5})_{x}, which of course would also lower the percentage of nitrogen. The most expeditious method of determining the nitrogen in these nitro bodies is by the use of Lungé's nitrometer (Fig. 41), and the best way of working the process is as follows:--Weigh out with the greatest care 0.6 grm. of the previously dried substance in a small weighing bottle of about 15 c.c. capacity, and carefully add 10 c.c. of concentrated sulphuric acid from a pipette, and allow to stand until all the cotton is dissolved. The nitrometer should be of a capacity 150 to 200 c.c., and should contain a bulb of 100 c.c. capacity at the top, and should be fitted with a Greiner and Friederich's three-way tap. When the nitro-cotton has entirely dissolved to a clear solution, raise the pressure tube of the nitrometer so as to bring the mercury in the measuring tube close up to the tap. Open the tap in order to allow of the escape of any air bubbles, and clean the surface of the mercury and the inside of the cup with a small piece of filter paper. Now close the tap, and pour the solution of the nitro-cotton into the cup. Rinse out the bottle with 15 c.c. of sulphuric acid, contained in a pipette, pouring a little of the acid over the stopper of the weighing bottle in case some of the solution may be on it. Now lower the pressure tube a little, just enough to cause the solution to flow into the bulb of the measuring tube, when the tap is slightly opened. When the solution has run in almost to the end, turn off the tap, wash down the sides of the bottle, and add to the cup of the nitrometer; allow it to flow in as before, and then wash down the sides of the cup with 10 c.c. of sulphuric acid, adding little by little, and allowing each portion added to flow into the bulb of the nitrometer before adding the next portion. Great care is necessary to prevent air bubbles obtaining admission, and if the pressure tube is lowered too far, the acid will run with a rush and carry air along with it. [Illustration: FIG. 41.--ORDINARY FORM OF LUNGÉ NITROMETER.] The solution being all in the measuring tube, the pressure tube is again slightly raised, and the tube containing the nitro-cotton solution shaken for ten minutes with considerable violence. It is then replaced in the clamp, and the pressure relieved by lowering the pressure tube, and the whole apparatus allowed to stand for twenty minutes, in order to allow the gas evolved to assume the temperature of the room. A thermometer should be hung up close to the bulb of the measuring tube. At the end of the twenty minutes, the levels of the mercury in the pressure and measuring tubes are equalised, and the final adjustment obtained by slightly opening the tap on the measuring tube (very slightly), after first adding a little sulphuric acid to the cup, and observing whether the acid runs in or moves up. This must be done with very great care. When accurately adjusted, it should move neither way. Now read off the volume of the NO gas in cubic centimetres from the measuring tube. Read also the thermometer suspended near the bulb, and take the height of the barometer in millimetres. The calculation is very simple. EXAMPLE--COLLODION-COTTON. 0.6[A] grm. taken. Reading on measuring tube = 114.6 c.c. NO. Barometer-- 758 mm. Temperature--15° C. [Footnote A: 0.5 grm. is enough in the case of gun-cotton.] Since 1 c.c. NO = 0.6272 milligramme N, and correcting for temperature and pressure by the formula 760 x (1 + _d_^{2}) (_d_ = .003665), for temperature 15° = 801.78,[A] then (114.6 x 100 x 750 x .6272)/(801.7 x. 6) = 11.22 per cent. nitrogen. [Footnote A: See Table, page 244.] The nitrogen in nitro-glycerine may of course be determined by the nitrometer, but in this case it is better to take a much smaller quantity of the substance. From 0.1 to 0.2 grm. is quite sufficient. This will give from 30 to 60 c.c. of gas, and therefore a measuring tube without a 100 c.c. bulb must be used. EXAMPLE. 0.1048 grm. nitroglycerine taken gave 32.5 c.c. NO. Barometer, 761 mm. Temperature, 15° C. Therefore, (3.25 x 100 x 761 x .6272)/(801.78 x.1048) = 18.46 per cent. N. Theory = 18.50 per cent. Professor Lungé has devised another form of nitrometer (Fig. 42), very useful in the nitrogen determination in explosives. It consists of a measuring tube, which is widened out in the middle to a bulb, and is graduated above and below into 1/10 c.c. The capacity of the whole apparatus is 130 c.c.; that of each portion of the tube being 30 c.c., and of the bulb 70 c.c. The upper portion of the graduated tube serves to measure small volumes of gas, whilst larger volumes are read off on the lower part. [Illustration: FIG. 42. FIG. 43. SOME NEW FORMS OF NITROMETER.] F.M. Horn (_Zeitschrift für angewandte Chemie_, 1892, p. 358) has devised a form of nitrometer (Fig. 43) which he has found especially useful in the examination of smokeless powders. The tap H is provided with a wide bore through which a weighed quantity of the powder is dropped bodily into the bulb K. From 4 to 5 c.c. of sulphuric acid which has been heated to 30° C. are then added through the funnel T, the tap H being immediately closed. When the powder has dissolved--a process which may be hastened by warming the bulb very carefully--the thick solution is drawn into the nitrometer tube N, and the bulb rinsed several times with fresh acid, after which operation the analysis is proceeded with in the usual way. Dr Lungé's method of using a separate nitrometer in which to measure the NO gas evolved to the one in which the reaction has taken place, the gas being transferred from the one to the other by joining them by means of indiarubber tubing, and then driving the gas over by raising the pressure tube of the one containing the gas, the taps being open, I have found to be a great improvement. 1 c.c. NO gas at 0° and 760 mm. Equals 0.6272 milligrammes (N) nitrogen. " 1.343 " nitric oxide. " 2.820 " (HNO_{3}) nitric acid. " 3.805 " (NaNO_{3}) sodium nitrate. " 4.523 " (KNO_{3}) potassium nitrate. ~Champion and Pellet's Method.~--This method is now very little used. It is based upon the fact that when nitro-cellulose is boiled with ferrous chloride and hydrochloric acid, all the nitrogen is disengaged as nitric oxide (NO). It is performed as follows:--A vacuum is made in a flask, fitted with a funnel tube, with a glass stopper on the tube; a delivery tube that can also be closed, and which dips under a solution of caustic soda contained in a trough, and the end placed under a graduated tube, also full of caustic soda. From 0.12 to 0.16 grm. cotton dissolved in 5 to 6 c.c. of sulphuric acid is allowed to flow into the flask, which contains the ferrous chloride and hydrochloric acid, and in which a vacuum has been formed by boiling, and then closing the taps. The solution is then heated, the taps on the delivery tube opened, and the end placed under the collecting tube, and the NO evolved collected. The NO gas is not evolved until the solution has become somewhat concentrated. Eder substituted a solution of ferrous sulphate in HCl for ferrous chloride. Care must be taken that the flask used is strong enough to stand the pressure, or it will burst. The same chemists (_Compt. Rendus_, lxxxiii. 707) also devised the following method for determining the NO_{2} in nitro-glycerine:--A known quantity of a solution of ferrous sulphate of previously ascertained reducing power is placed in a flask, acidified with hydrochloric acid, and its surface covered with a layer of petroleum oil. About .5 grm. of the nitro-glycerine is then introduced, and the flask heated on the water bath. When the sample is completely decomposed, the liquid is heated to boiling to remove nitric oxide, and the excess of ferrous sulphate ascertained by titration with standard permanganate; 56 of iron (Fe) oxidised by the sample correspond to 23 of NO_{2} in the sample of nitro-glycerine. ~The Schultze-Tieman Method~ for determining nitrogen in nitro-explosives, especially nitro-cellulose and nitro-glycerine.--The figure (No. 44) shows the general arrangement of the apparatus. I am indebted for the following description of the method of working it to my friend, Mr William Bate, of Hayle. To fill the apparatus with the soda solution, the gas burette is put on the indiarubber stopper of basin W, and firmly clamped down. Then the taps A and C are opened, and B closed. When the burette is filled with soda solution half-way up the funnel Y, A and C are closed, and B opened. The arrows show the inlet and outlet for the cooling water that is kept running through the water jacket round the nitrometer tube. To collect the gas, raise the nitrometer off the rubber stopper, and place the gas tube from the decomposition apparatus in the glass dish W and under the opening of the nitrometer. [Illustration: Fig. 44. SCHULTZE-TIEMAN APPARATUS.] For the estimation of nitrogen in nitro-cellulose take .5 to .65 grm., and place in the decomposition flask _f_ (Fig. 45), washing in with about 25 c.c. of water by alternately opening clips D and E. The air in the flask is driven out by boiling, whilst the air is shut off by the tube _i_ dipping into the basin W, which is filled with the soda lye, and tube K is placed in the test tube R, which contains a few c.c. of water. As soon as all the air is completely driven out, clips D and E are closed, and the gas jet is taken away. (This flask must be a strong one, or it will burst.) Into test tube R, 25 c.c. of concentrated solution of protochloride of iron and 10 to 15 c.c. concentrated hydrochloric acid are poured, which are sucked up into the developing flask _f_ by opening clip E, air being carefully kept from entering. The clip E is now closed, and tube _i_ is put underneath the burette, and the development of NO gas is commenced by heating the contents of the flask _f_. When the pressure of the gas in the flask has become greater than the pressure of the atmosphere, the connecting tube begins to swell at _i_, whereupon clip D is opened, and the boiling continued with frequent shaking of the bulb, until no more nitrous gas bubbles rise up into the soda lye, the distilling over of the HCl causes a crackling noise, the clip D is closed, and E opened. The burette is again put hermetically on the indiarubber stopper in basin W, and the apparatus is left to cool until the water discharged through P shows the same temperature as the water flowing through (into the cooling jacket) Z. If the level of the soda solution in the tube X is now put on exactly the same level as that in the burette by lowering or elevating the tube X as required, the volume of NO obtained in c.c. can be read off within 1/10 c.c., and the percentage of nitrogen calculated by the usual formula. [Illustration: FIG. 45.--Decomposition Flask for Schultze-Tieman Method.] The solution of protochloride of iron is obtained by dissolving iron nails, &c., in concentrated HCl, the iron being in excess. When the development of hydrogen ceases, it is necessary to filter warm through a paper filter, and acidify filtrate with a few drops of HCl. The soda solution used has a sp. gr. of 1.210 to 1.260; equals 25° to 30° B. The nitro-cellulose is dried in quantities of 2 grms. at 70° C. during eight to ten hours, and then three hours in an exiccator over H_{2}SO_{4}. The results obtained with this apparatus are very accurate. The reaction is founded upon that of MM. Champion and Pellet's method. ~The Kjeldahl Method of Determining Nitrogen.~--This method, which has been so largely used by analysts for the determination of nitrogen in organic bodies, more especially perhaps in manures, was proposed by J. Kjeldahl,[A] of the Carlsberg Laboratory of Copenhagen. It was afterwards modified by Jodlbauer, of Munich,[B] and applied to the analysis of nitro- explosives by M. Chenel, of the Laboratoire Centrale des Poudres, whose method of procedure is as follows:--0.5 grm. of the finely powdered substance is digested in the cold with a solution of 1.2 grm. of phenol and 0.4 grm. phosphoric anhydride in 30 c.c. of sulphuric acid. The mixture is kept well shaken until the solution is complete. From 3 to 4 grms. of zinc-dust is then cautiously and gradually added, the temperature of the mass being kept down until complete reduction has been effected. Finally, 0.7 grm. of mercury is added, and the process continued in the usual way, according to Kjeldahl; that is, the liquid is distilled until all the ammonia has passed over, and is absorbed in the standard acid. The distillate is then titrated with standard ammonia. [Footnote A: J. Kjeldahl, _Zeitschrift Anal. Chem._, 1883, xxii., p. 366.] [Footnote B: Jodlbauer, _Chemisches Centralblatt_, 1886, pp. 434-484. See also _Arms and Explosives_, 1893, p. 87.] The NO_{2} group is at the moment of solution fixed upon the phenol with the production of mono-nitro-phenol, which is afterwards reduced by the action of the zinc-dust into the amido derivative. During the subsequent combustion, the nitrogen of the amido-phenol becomes fixed in the state of ammonia. M. Chenel is perfectly satisfied with the results obtained, but he points out that the success of the operation depends upon the complete conversion of the phenol into the mono-nitro derivatives. This takes place whenever the organic compound forms a _clear solution_ in the cold sulphuric acid mixture. Substances like collodion or gun-cotton must be very finely divided for successful treatment. The following table shows some of the results obtained by M. Chenel:-- ______________________________________________ | | | | | Total Nitrogen. | | Substances Analysed. |______________________| | | | | | | Calculated. | Found. | | |_____________|________| | | | | | Saltpetre (KNO_{3}) | 13.86 | 13.91 | | | | 13.82 | | | | 13.73 | | | | 13.96 | | Ammonium nitrate | 35.00 | 35.31 | | | | 34.90 | | | | 34.96 | | Barium nitrate | 10.72 | 10.67 | | | | 10.62 | | Nitro-glycerol | 18.50 | 18.45 | | Di-nitro-benzol[A] | 16.67 | 16.78 | | | | 16.57 | | Para-nitro-phenol | 10.07 | 10.03 | | Picric acid[A] | 18.34 | 18.42 | | | | 18.43 | | Ammonium picrate | 22.76 | 22.63 | | | | 22.67 | | Di-nitro-ortho-cresol | 14.14 | 14.10 | | | | 13.98 | | Tri-nitro-meta-cresol | 17.28 | 17.57 | | | | 17.27 | |_______________________|_____________|________| [Footnote A: Dr. Bernard Dyer obtained 18.39 per cent. for picric acid and 16.54 per cent. for di-nitro-benzol.--_Jour. Chem. Soc._, Aug. 1895.] When Chenel endeavoured to apply Jodlbauer's modification of Kjeldahl's process to the examination of the tri- and tetra-nitrated naphthalenes, he found that good results were not obtainable, because these compounds do not dissolve completely in the cold sulphuric acid. It may, however, be used if they are previously converted into the naphthylamines, according to the plan proposed by D'Aguiar and Lautemann (_Bull. Soc. Chim._, vol. iii., new series, p. 256). This is rapidly effected as follows:--Twelve grms. of iodine are gradually added to a solution of 2 grms. of phosphorus in about 15 or 20 c.c. of bisulphide of carbon, this solution being contained in a flask of 250 c.c. capacity. The flask and its contents are heated on the water bath at 100° C. with constant attention, until the last traces of the carbon bisulphide have distilled away. It is then cooled, and the iodide of phosphorus is detached from the sides of the flask by shaking, but not expelled. The next step is to add about 0.5 to 0.6 grm. of the substance that is to be analysed, after which 8 grms. of water are introduced, and the flask is agitated gently two or three times. As soon as the reaction becomes lively, the contents of the flask are well shaken. It is usually finished about one minute after the addition of the water. The flask is now cooled, and 25 c.c. of sulphuric acid, together with 0.7 grm. of mercury, are gradually added; hydriodic acid (HI) forms, and the temperature of the flask must be raised sufficiently to expel it. The remaining part of the operation is as in the ordinary Kjeldahl process. M. Chenel has found this process the best for the analysis of the nitro- naphthalenes, and for impervious substances like collodion or gun-cotton. Personally, I have never been able to obtain satisfactory results with this process in the analysis of nitro-cellulose, and I am of opinion that the process does not possess any advantage over the nitrometer method, at any rate for the analysis of gun-cotton. Table giving the Percentages of Nitrogen and Oxide of Nitrogen in Various Substances used in or as Explosives: Name FORMULÆ NITROGEN NO_{2} per cent. per cent. Nitroglycerine C_{3}H_{5}(ONO_{2})_{3} 18.50 = 60.70 Hexa-nitro-cellulose C_{12}H_{14}O_{4}(ONO_{2})_{6} 14.14 = 46.42 Penta-nitro-cellulose C_{6}H_{8}O_{5}(ONO_{2})_{5} 11.11 = 36.50 Nitro-benzene C_{6}H_{5}NO_{2} 11.38 = 37.39 Di-nitro-benzene C_{6}H_{4}(NO_{2})_{2} 16.67 = 54.77 Tri-nitro-benzene C_{6}H_{3}(NO_{2})_{3} 19.24 = 63.22 Nitro-toluene C_{7}H_{7}NO_{2} 10.21 = 33.49 Nitro-naphthalene C_{10}H_{7}NO_{2} 8.09 = 26.53 Di-nitro-naphthalene C_{10}H_{6}(NO_{2})_{2} 12.84 = 42.12 Nitro-mannite C_{6}H_{7}(NO_{3})_{6} 23.59 = 77.37 Nitro-starch C_{6}H_{8}O_{4}(HNO_{3}) 6.76 = 22.18 Picric acid (Tri-nitro-phenol) C_{6}H_{2}OH(NO_{2})_{3} 18.34 = 60.15 Chloro-nitro-benzene C_{6}H_{3}Cl(NO_{2})_{2} 13.82 = 45.43 Ammonium nitrate NH_{4}NO_{3} 35.00 = Sodium nitrate NaNO_{3} 16.47 = Potassium nitrate KNO_{3} 13.86 = Nitric acid HNO_{3} 22.22 = Barium nitrate Ba(NO_{3})_{2} 10.72 = ~Analysis of Celluloid.~--The finely divided celluloid is well stirred, by means of a platinum wire, with concentrated sulphuric acid in the cup of a Lungé nitrometer, and when dissolved the nitrogen determined in the solution in the usual way. To prevent interference from camphor, the following treatment is suggested by H. Zaunschirm (_Chem. Zeit._, xiv., 905). Dissolve a weighed quantity of the celluloid in a mixture of ether- alcohol, mixed with a weighed quantity of washed and ignited asbestos, or pumice-stone, dry, and disintegrate the mass, and afterwards extract the camphor with chloroform, dry, and weigh: then extract with absolute methyl-alcohol, evaporate, weigh, and examine the nitro-cellulose in the nitrometer. ~Picric Acid and Picrates.~--Picric acid is soluble in hot water, and to the extent of 1 part in 100 in cold water, also in ether, chloroform, glycerine, 10 per cent. soda solution, alcohol, amylic alcohol, carbon bisulphide, benzene, and petroleum. If a solution of picric acid be boiled with a strong solution of potassium cyanide, a deep red liquid is produced, owing to the formation of potassium iso-purpurate, which crystallises in small reddish-brown plates with a beetle-green lustre. This, by reaction with ammonium chloride, gives ammonium iso-purpurate (NH_{4}C_{8}H_{4}N_{5}O_{6}), or artificial murexide, which dies silk and wool a beautiful red colour. On adding barium chloride to either of the above salts, a vermilion-red precipitate was formed, consisting of barium iso-purpurate. With ammonio-sulphate of copper, solutions of picric acid give a bright green precipitate. Mr A.H. Allen gives the following methods for the assay of commercial picric acid, in his "Commercial Organic Analysis":-- ~Resinous and Tarry matters~ are not unfrequently present. They are left insoluble on dissolving the sample in boiling water. The separation is more perfect if the hot solution be exactly neutralised by caustic soda. ~Sulphuric Acid, Hydrochloric Acid, and Oxalic Acid~, and their salts are detected by adding to the filtered aqueous solution of the sample solutions of the picrates of barium, silver, and calcium. These salts are readily made by boiling picric acid with the carbonates of the respective metals and filtering: other soluble salts of these methods may be substituted for the picrates, but they are less satisfactory. ~Nitric Acid~ may be detected by the red fumes evolved on warming the sample with copper turnings. ~Inorganic Impurities and Picrates of Potash and Sodium~, &c., leave residues on cautious ignition. ~General Impurities and Adulterations~ may be detected and determined by shaking 1 grm. of the sample of acid in a graduated tube with 25 c.c. of ether, the pure acid dissolves, while any oxalic acid, nitrates, picrates, boric acid, alum, sugar, &c., will be left insoluble, and after removal of the ethereal liquid, may be readily identified and determined. For the detection and determination of water and of oxalic acid, 50 c.c. of warm benzene may be advantageously substituted for ether. Sugar may be separated from the other impurities by treating the residue insoluble in ether or benzene with rectified spirit, in which sugar and boric acid alone will dissolve. If boric acid be present, the alcoholic solution will burn with a green flame. Mono- and di-nitrophenic acids lower the melting point (122° C). Their calcium salts are less soluble than the picrate, and may be approximately separated from it by fractional crystallisation, or by precipitating the hot saturated solution of the sample with excess of lime water. Picric acid may be determined by extracting the acidulated aqueous solution by agitation with ether or benzene, and subsequently removing and evaporating off the solvent. It may also be precipitated as the potassium salt. ~Potassium Picrate~ [KC_{6}H_{2}(NO_{2})_{3}O]. When a strong solution of picric acid is neutralised by carbonate of potash, this salt is thrown down in yellow crystalline needles, which require 260 parts of cold or 14 parts of hot water for their solution. In alcohol it is much less soluble. ~Ammonium Picrate~ is more soluble in water than the above, and sodium picrate is readily soluble in water, but nearly insoluble in solution of sodium carbonate. ~Picrates of the Alkaloids.~--Picric acid forms insoluble salts with many of the alkaloids, and picric acid may be determined in the following manner:--To the solution of picric acid, or a picrate, add a solution of sulphate of cinchonine acidulated with H_{2}SO_{4}. The precipitated picrate of cinchonine [C_{20}H_{24}N_{2}O(C_{6}H_{2}N_{3}O_{7})_{2}] is washed with cold water, rinsed off the filter into a porcelain crucible or dish, the water evaporated on the water bath, and the residual salt weighed. Its weight, multiplied by .6123, gives the quantity of picric acid in the sample taken. ~Analysis of Glycerine.~[A] Glycerine that is to be used for the manufacture of nitro-glycerine should have a minimum specific gravity of 1.261 at 15° C. This can be determined, either by the aid of a Sartorius specific gravity balance, or by using an ordinary specific gravity bottle. One of 10 or 25 c.c. capacity is very convenient. [Footnote A: See also Sulman and Berry, _Analyst_, xi., 12-34, and Allen's "Commercial Organic Analysis," vol. ii., part i.] ~Residue~[A] left upon evaporation should not be more than 0.25 per cent. To determine this, take 25 grms. of the glycerine, and evaporate it at a temperature of about 160° C. in a platinum basin, and finish in an air bath. Weigh until constant weight is obtained. Afterwards incinerate over a bunsen burner, and weigh the ash. [Footnote A: Organic matter up to .6 per cent. is not always prejudicial to the nitrating quantities of a glycerine.] ~Silver Test.~ A portion of the sample of glycerine to be tested should be put in a small weighing bottle, and a quarter of its bulk of N/10 silver nitrate solution added to it, then shake it, and place in a dark cupboard for fifteen minutes. It must be pronounced bad if it becomes black or dark brown within that time (acrolein, formic, and butyric acids). The German official test for glycerine for pharmaceutical purposes is much more stringent, 1 c.c. of glycerine heated to boiling with 1 c.c. of ammonia solution and three drops of silver nitrate solution must give neither colour or precipitate within five minutes. ~Nitration.~ Fifty grms. of the glycerine are poured from a beaker into a mixture of concentrated nitric acid (specific gravity 1.53) and sulphuric acid (1.84), mixed in the proportions of 3 HNO_{3} to 5 H_{2}SO_{4} (about 400 c.c. of mixed acids). The mixed acids should be put into a rather large beaker, and held in the right hand in a basin of water, and the glycerine slowly poured into them from a smaller one held in the left. A constant rotatory motion should be given to the beaker in which the nitration is performed. When all the glycerine has been added, and the mixture has been shaken for a few minutes longer, it is poured into a separator, and allowed to stand for some time. It should, if the glycerine is a good one, have separated from the mixed acids in ten minutes, and the line of demarcation between the nitro-glycerine and the acid should be clear and sharp, neither should there be any white flocculent matter suspended in the liquid. The excess of acids is now drawn off, and the nitro-glycerine shaken once or twice with a warm solution of carbonate of soda, and afterwards with water alone. The nitro-glycerine is then drawn off into a weighed beaker, the surface dried with a piece of filter paper, and weighed; 100 parts of a good glycerine should yield about 230 of nitro-glycerine. A quicker method is to take only 10 c.c. of the glycerine, of which the specific gravity is already known, nitrate as before, and pour into a burette, read off the volume of nitro-glycerine in c.c. and multiply them by 1.6 (the specific gravity of nitro-glycerine), thus: 10 grms. gave 14.5 c.c. nitro-glycerine, and 14.5 x 1.6 = 23.2 grms., therefore 100 would give 232 grms. nitro-glycerine. The points to be noted in the nitration of a sample of glycerine are: the separation should be sharp, and within half an hour or less, and there should be no white flocculent matter formed, especially when the carbonate of soda solution is added. ~Total Acid Equivalent.~ Mr G.E. Barton (_Jour. Amer. Chem. Soc._, 1895) proposes to determine thus: 100 c.c. of glycerine are diluted to 300 c.c. in a beaker, a few drops of a 1 per cent. solution of phenolphthalein and 10 c.c. of normal caustic soda solution are added; after boiling, the liquid is titrated with normal hydrochloric acid (fatty acids are thus indicated and roughly determined). ~Neutrality.~ The same chemist determines the neutrality of glycerine thus: 50 c.c. of glycerine mixed with 100 c.c. of water and a few drops of alcoholic phenolphthalein[A] are titrated with hydrochloric acid or sodium hydroxide; not more than 0.3 c.c. normal hydrochloric acid or normal soda solution should be required to render the sample neutral; raw glycerines contain from .5 to 1.0 per cent. of sodium carbonate. [Footnote A: Sulman and Berry prefer litmus as indicator.] ~Determination of Free Fatty Acids.~ A weighed quantity of the glycerine is shaken up with some neutral ether in a separating funnel, the glycerine allowed to settle, drawn off, and the ether washed with three separate lots of water. The water must have been recently boiled, and be quite free from CO_{2}. All the free fatty acid is now in the ether, and no other soluble acid. A drop of phenolphthalein is now added, a little water, and the acidity determined by titration with deci-normal baryta solution, and the baryta solution taken calculated as oleic acid. ~Combined Fatty Acid.~ About 30 grms. of the glycerine are placed in a flask, and to it is added about half a grm. of caustic soda in solution. The mixture is heated for ten minutes at 150° C. After cooling some pure ether is added to it, and enough dilute H_{2}SO_{4} to render it distinctly acid. It is well shaken. All the fatty acids go into the ether. The aqueous solution is then removed, and the ether well washed to remove all H_{2}SO_{4}. After the addition of phenolphthalein the acid is titrated, and the amount used calculated into oleic acid. From this total amount of fatty acids the free fatty acid is deducted, and the quantity of combined fatty acids thus obtained. ~Impurities.~ The following impurities may be found in bad samples of glycerine:--Lead, arsenic, lime, chlorine, sulphuric acid, thio-sulphates, sulphides, cyanogen compounds, organic acids (especially oleic acid and fatty acids[A]), rosin products, and other organic bodies. It is also said to be adulterated with sugar and glucose dextrine. Traces of sulphuric acid and arsenic may be allowed, also very small traces indeed of lime and chlorine. [Footnote A: These substances often cause trouble in nitrating, white flocculent matter being formed during the process of washing.] The organic acids, formic and butyric acids may be detected by heating a sample of the glycerine in a test tube with alcohol and sulphuric acid, when, if present, compound ethers, such as ethylic formate and butyrate, the former smelling like peaches and the latter of pine-apple, will be formed. ~Oleic Acid~, if present in large quantity, will come down upon diluting the sample with water, but smaller quantities may be detected by passing a current of nitrogen peroxide, N_{2}O_{4} (obtained by heating lead nitrate), through the diluted sample, when a white flocculent precipitate of elaidic acid, which is less soluble than oleic acid, will be thrown down. By agitating glycerol with chloroform, fatty acids, rosin oil, and some other impurities are dissolved, while certain others form a turbid layer between the chloroform and the supernatant liquid. On separating the chloroform and evaporating it to dryness, a residue is obtained which may be further examined. ~Sodium Chloride~ can be determined in 100 c.c. of the glycerine by adding a little water, neutralised with sodium carbonate, and then titrated with a deci-normal solution of silver nitrate, using potassium chromate as indicator. ~Organic Impurities~ of various kinds occur in crude glycerine, and are mostly objectionable. Their sum may be determined with fair accuracy by Sulman and Berry's method: 50 grms. of the sample are diluted with twice its measure of water, carefully neutralised with acetic acid, and warmed to expel carbonic acid; when cold, a solution of basic lead acetate is added in slight but distinct excess, and the mixture well agitated. The formation of an abundant precipitate, which rapidly subsides, is an indication of considerable impurity in the sample. To ascertain its amount, the precipitate is first washed by decantation, and then collected on a tared, or preferably a double counter-poised filter, where it is further washed, dried at 100° to 105° C., and weighed. The precipitate and filter paper are then ignited separately in porcelain, at a low red heat, the residues moistened with a few drops of nitric acid and reignited; the weight of the lead oxide deducted from that of the original precipitate gives the weight of the organic matter precipitated by the lead. Raw glycerines contain from 0.5 to 1.0 per cent. ~Albuminous Matters.~ An approximate determination of the albuminous matters may be made by precipitating with basic lead acetate as already described, and determining the nitrogen by the Kjeldahl method; the nitrogen multiplied by 6.25 gives the amount of albuminous matter in the precipitate. ~The Determination of Glycerine.~ The acetin method of Benedikt and Canton depends upon the conversion of glycerine into triacetin, and the saponification of the latter, and reduces the estimation of glycerine to an acidmetric method. About 1.5 grm. of crude glycerine is heated to boiling with 7 grms. of acetic anhydride, and 3 to 4 grms. of anhydrous sodium acetate, under an upright condenser for one and a half hours. After cooling, 50 c.c. of water are added, and the mixture heated until all the triacetin has dissolved. The liquid is then filtered into a large flask, the residue on the filter is well washed with water, the filtrate quite cooled, phenolphthalein is added and the fluid exactly neutralised with a dilute (2 to 3 per cent.) solution of alkali. Twenty-five c.c. of a 10 per cent. caustic soda solution, which must be accurately standardised upon normal acid, are then pipetted into the liquid, which is heated to boiling for ten minutes to saponify the triacetin, and the excess of alkali is then titrated back with normal acid. One c.c. of normal acid corresponds to .03067 grm. of glycerine. ~Precautions.~--The heating must be done with a reflux condenser, the triacetin being somewhat volatile. The sodium acetate used must be quite anhydrous, or the conversion of the glycerine to triacetyl is imperfect. Triacetin in contact with water gradually decomposes. After acetylation is complete, therefore, the operations must be conducted as rapidly as possible. It is necessary to neutralise the free acetic acid very cautiously, and with rapid agitation, so that the alkali may not be locally in excess. ~The Lead Oxide Method.~--Two grms. of sample are mixed with about 40 grms. of pure litharge, and heated in an air bath to 130° C. until the weight becomes constant, care being taken that the litharge is free from such lead compounds and other substances as might injuriously affect the results, and that the heating of the mixture takes place in an air bath free from carbonic acid. The increase in weight in the litharge, minus the weight of substance not volatilisable from 2 grms. of glycerine at 160° C., multiplied by the factor 1.243, is taken as the weight of glycerine in the 2 grms. of sample. The glycerine must be fairly pure, and free from resinous substances and SO_{3}, to give good results by this process. ~Analysis of the "Waste Acids" from the Manufacture of Nitro-Glycerine or Gun-Cotton.~ Determine the specific gravity by the specific gravity bottle or hydrometer, and the oxides of nitrogen by the permanganate method described under nitro-glycerine. Now determine the total acidity of the mixture by means of a tenth normal solution of sodium hydrate, and calculate it as nitric acid (HNO_{3}), then determine the nitric acid by means of Lungé nitrometer, and subtract percentage found from total acidity, and calculate the difference into sulphuric acid, thus:-- Total acidity equals 97.46 per cent.--11.07 per cent. HNO_{3} = 86.39 per cent., then (86.39 x 49)/63 = 67.20 per cent. H_{2}SO_{4}. Then analysis of sample will be:-- _ Sulphuric acid = 67.20 per cent. | Nitric acid = 11.07 " |- Specific gravity = 1.7075. Water = 12.73 " _| This method is accurate enough for general use in the nitric acid factory. The acid mixture may be taken by volume for determining nitric oxide in nitrometer. Two c.c. is a convenient quantity in the above case, then 2 x 1.7075 (specific gravity) = 3.414 grms. taken, gave 145 c.c. NO (barometer = 748 mm, and temperature = 15°C.) equals 134.9 c.c. (corr.) and as 1 c.c. NO = .0282 grm. HNO_{3} 135 x .0282 = .378 grm. = 11.07 per cent. nitric acid. ~Sodium Nitrate.~ Determine moisture and chlorine by the usual methods, and the total, NaNO_{3}, by means of nitrometer--0.45 grm. is a very convenient quantity to work on (gives about 123 c.c. gas); grind very fine, and dissolve in a very little hot water in the cup of the nitrometer; use about 15 c.c. concentrated H_{2}SO_{4}. One cubic cent. of NO equals .003805 grm. of NaNO_{3}. The insoluble matter, both organic and inorganic, should also be determined, also sulphate of soda and lime tested for. ~Analysis of Mercury Fulminate (Divers and Kawakita's Method).~--A weighed quantity of mercury fulminate is added to excess, but measured quantity of fuming hydrochloric acid contained in a retort connected with a receiver holding water. After heating for some time, the contents of the retort and receiver are mixed and diluted, and the mercury is precipitated by hydrogen sulphide. By warming and exposure to the air in open vessels the hydrogen sulphide is for the most part dissipated. The solution is then titrated with potassium hydroxide (KOH), as well as another quantity of hydrochloric acid, equal to that used with the fulminate. As the mercury chloride is reconverted into hydrochloric acid by the hydrogen sulphide, and as the hydroxylamine does not neutralise to litmus the hydrochloric acid combined with it, there is an equal amount of hydrochloric acid free or available in the two solutions. Any excess of acid in the one which has received the fulminate will therefore be due to the formic acid generated from the fulminate. Dr. Divers and M. Kawakita, working by this method, have obtained 31.31 per cent. formic acid, instead of 32.40 required by theory. (_Jour. Chem. Soc._, p. 17, 1884.) Divers and Kawakita proceed thus: 2.351 grms. dissolved, as already described, in HCl, and afterwards diluted, gave mercury sulphide equal to 70.40 per cent. mercury. The same solution, after removal of mercury, titrated by iodine for hydroxylamine, gave nitrogen equal to 9.85 per cent., and when evaporated with hydroxyl ammonium chloride equal to 9.55 per cent. A solution of 2.6665 grms. fulminate in HCl of known amount, after removal of mercury by hydrogen sulphide, gave by titration with potassium hydrate, formic acid equal to 8.17 per cent. of carbon. Collecting and comparing with calculation from formula we get-- Calc. I. II. III. Mercury 70.42 70.40 ... ... Nitrogen 9.86 9.85 9.55 ... Carbon 8.45 ... ... 8.17 Oxygen 11.27 ... ... ... _______ 100.00 ~The Analysis of Cap Composition.~--Messrs F.W. Jones and F.A. Willcox (_Chem. News_, Dec. 11, 1896) have proposed the following process for the analysis of this substance:--Cap composition usually consists of the ingredients--potassium chlorate, antimony sulphide, and mercury fulminate, and to estimate these substances in the presence of each other by ordinary analytical methods is a difficult process. Since the separation of antimony sulphide and mercury fulminate in the presence of potassium chlorate necessitates the treatment of the mixture with hydrochloric acid, and this produces an evolution of hydrogen sulphide from the sulphide, and a consequent precipitation of sulphur; and potassium chlorate cannot be separated from the other ingredients by treatment with water, owing to the appreciable solubility of mercury fulminate in cold water. In the course of some experiments on the solubility of mercury fulminate Messrs Jones and Willcox observed that this body was readily soluble in acetone and other ethereal solvents when they were saturated with ammonia gas, and that chlorate of potash and sulphide of antimony were insoluble in pure acetone saturated with ammonia; these observations at once afforded a simple method of separating the three ingredients of cap composition. By employing this solution of acetone and ammonia an analysis can be made in a comparatively short time, and yields results of sufficient accuracy for all technical purposes. The following are the details of the process:-- A tared filter paper is placed in a funnel to the neck of which has been fitted a piece of rubber tubing provided with a clip. The paper is moistened with a solution of acetone and ammonia, the cap composition is weighed off directly on to the filter paper and is then covered with the solution of acetone and ammonia and allowed to stand thirty-four hours. It is then washed repeatedly with the same solution until the washings give no coloration with ammonium sulphide, and afterwards washed with acetone until washings give no residue on evaporation dried and weighed. The paper is again put in the funnel and washed with water until free from potassium chlorate, dried and weighed. If _c_ = weight of composition taken, _d_ = " " filter paper, _a_ = " after first extraction, _b_ = " " second extraction, then _c+d-a_ = weight of fulminate, _c+d-a-b_ = " " KClO_{3}, _b-d_ = " " sulphide of antimony. The composition should be finely ground in an agate mortar. The results of the analysis by this method of two mixtures of known composition are given below-- ________________________________________________________________________ | | | | | | A | B | | | | | | | Percentage | Percentage | Percentage | Percentage | | | Taken. | Found. | Taken. | Found. | |____________________|____________|____________|____________|____________| | | | | | | | Antimony Sulphide | 36.47 | 36.25 | 37.34 | 37.22 | | Potassium Chlorate | 33.25 | 33.71 | 46.03 | 46.43 | | Mercury Fulminate | 30.27 | 30.02 | 16.61 | 16.34 | |____________________|____________|____________|____________|____________| Dr. H.W. Brownsdon's (_Jour. Soc. Chem. Ind._, xxiv., April 1905) process is as follows:--The cap composition is removed by squeezing the cap with pliers, while held over a porcelain basin of about 200 c.c. capacity, and removing the loosened foil and broken composition by means of a pointed wooden chip. Composition adhering to the shell or foil is loosened by alcohol, and washed into the dish by means of alcohol in a small wash bottle. The shell and foil are put to one side and subsequently weighed when dry. The composition in the dish is broken down quite fine with a flat-headed glass rod, and the alcohol evaporated on the water bath till the residue is moist, but not quite dry, 25 c.c. of water are then added, and the composition well stirred from the bottom. After the addition of 0.5 grm. of pure sodium, thiosulphate, the contents of the dish, is well stirred for two and a half minutes. One drop of methyl orange is then added, and the solution titrated with N/20 sulphuric acid, which has been standardised against weighings of 0.05-0.1 grm. fulminate to which 25 c.c. of water is added in a porcelain dish, then 0.5 grm. of thiosulphate, and after stirring for two and a half minutes, titrated with N/20 sulphuric acid. The small amount of antimony sulphide present does not interfere with the recognition of the end point. After titration, the solution is filtered through a small 5-1/2 cm. filter paper, which retains the antimony sulphide. The filter paper containing the Sb_{2}S_{3} is well washed and then transferred to a large 6 by 1 test tube. Five c.c. of strong hydrochloric acid are added, and the contents of the tube boiled gently for a few seconds until the sulphide is dissolved and all the H_{2}S driven off or decomposed: 2-3 c.c. of a saturated solution of tartaric acid are added, and the contents of the tube washed into a 250 c.c. Erlenmeyer flask. The solution is then nearly neutralised with sodium carbonate, excess of bi-carbonate added, and after the addition of some starch solution titrated with N/20 iodine solution. This method for small quantities of stibnite is both quick and accurate, the error being about ±0.0003 grm. Sb_{2}S_{3} at the outside. The tendency of this method is to give slightly low figures for the fulminate, but since these are uniform within a negligible error, it does not affect the value of the results as a criterion of uniformity. The following test results were obtained by Dr Brownsdon:-- ____________________________________________________________ | | | | | Fulminate Taken. | Fulminate Found. | Error. | | Grm. | Grm. | Grm. | | | | | | 0.0086 | 0.0083 | -0.0003 | | 0.0082 | 0.0081 | -0.0001 | | 0.0074 | 0.0071 | -0.0003 | | 0.0068 | 0.0066 | -0.0002 | |____________________|___________________|___________________| | | | | | Stibnite Taken. |Sb_{2}S_{3}, Found.| Error. | | Grm. | Grm. | Grm. | | | | | | 0.0085 | 0.0084 | -0.0001 | | 0.0098 | 0.0099 | +0.0001 | | 0.0160 | 0.0157 | -0.0003 | | 0.0099 | 0.0100 | +0.0001 | |____________________|___________________|___________________| TABLE FOR CORRECTION OF VOLUMES OF GASES FOR TEMPERATURE, GIVING THE DIVISOR FOR THE FORMULA. V_{1} = V x B/(760 x (1 + dt)) (d = 0.003665) 1 + dt from 0° to 30° C. ___________________________________________________________ | | | | | t. | 760x(1+dt). | t. | 760x(1+dt). | t. | 760x(1+dt). _____|_____________|_____|_____________|_____|_____________ | | | | | °C. | | °C. | | °C. | 0.0 | 750.000 | 1.7 | 764.7352 | 3.4 | 769.4704 .1 | 760.2785 | .8 | 765.0137 | .5 | 769.7489 .2 | 760.5571 | .9 | 765.2923 | .6 | 770.0274 .3 | 760.8356 | 2.0 | 765.5708 | .7 | 770.3060 .4 | 761.1142 | .1 | 765.8493 | .8 | 770.5845 .5 | 761.3927 | .2 | 766.1279 | .9 | 770.8631 .6 | 761.6712 | .3 | 766.4064 | 4.0 | 771.1416 .7 | 761.9498 | .4 | 766.6850 | .1 | 771.4201 .8 | 762.2283 | .5 | 766.9635 | .2 | 771.6987 .9 | 762.5069 | .6 | 767.2420 | .3 | 771.9772 1.0 | 762.7854 | .7 | 767.5206 | .4 | 772.2558 .1 | 763.0639 | .8 | 767.7991 | .5 | 772.5343 .2 | 763.3425 | .9 | 768.0777 | .6 | 772.8128 .3 | 763.6210 | 3.0 | 768.3562 | .7 | 773.0914 .4 | 763.8996 | .1 | 768.6347 | .8 | 773.3699 .5 | 764.1781 | .2 | 768.9133 | .9 | 773.6485 .6 | 764.4566 | .3 | 769.1918 | 5.0 | 773.9270 _____|_____________|_____|_____________|_____|_____________ ___________________________________________________________ | | | | | t. | 760x(1+dt). | t. | 760x(1+dt). | t. | 760x(1+dt). _____|_____________|_____|_____________|_____|_____________ | | | | | °C. | | °C. | | °C. | 5.1 | 774.2055 | .9 | 787.5755 | .7 | 800.9454 .2 | 774.4841 |10.0 | 787.8540 | .8 | 801.2239 .3 | 774.7626 | .1 | 788.1325 | .9 | 801.5025 .4 | 775.0412 | .2 | 788.4111 |15.0 | 801.7810 .5 | 775.3197 | .3 | 788.6896 | .1 | 802.0595 .6 | 775.5982 | .4 | 788.9682 | .2 | 802.3381 .7 | 775.8768 | .5 | 789.2467 | .3 | 802.6166 .8 | 776.1553 | .6 | 789.5252 | .4 | 802.8952 .9 | 776.4339 | .7 | 789.8038 | .5 | 803.1737 6.0 | 776.7124 | .8 | 790.0823 | .6 | 803.4522 .1 | 776.9909 | .9 | 790.3609 | .7 | 803.7308 .2 | 777.2695 |11.0 | 790.6394 | .8 | 804.0093 .3 | 777.5480 | .1 | 790.9179 | .9 | 804.2879 .4 | 777.8266 | .2 | 791.1965 |16.0 | 804.5664 .5 | 778.1051 | .3 | 791.4750 | .1 | 804.8449 .6 | 778.3836 | .4 | 791.7536 | .2 | 805.1235 .7 | 778.6622 | .5 | 792.0321 | .3 | 805.4020 .8 | 778.9407 | .6 | 792.3106 | .4 | 805.6806 .9 | 779.2193 | .7 | 792.5892 | .5 | 805.9591 7.0 | 779.4978 | .8 | 792.8677 | .6 | 806.2376 .1 | 779.7763 | .9 | 793.1463 | .7 | 806.5162 .2 | 780.0549 |12.0 | 793.4248 | .8 | 806.7947 .3 | 780.3334 | .1 | 793.7033 | .9 | 807.0733 .4 | 780.6120 | .2 | 793.9819 |17.0 | 807.3518 .5 | 780.8905 | .3 | 794.2604 | .1 | 807.6303 .6 | 781.1690 | .4 | 794.5390 | .2 | 807.9089 .7 | 781.4476 | .5 | 794.8175 | .3 | 808.1874 .8 | 781.7261 | .6 | 795.0960 | .4 | 808.4660 .9 | 782.0047 | .7 | 795.3746 | .5 | 808.7445 8.0 | 782.2832 | .8 | 795.6531 | .6 | 809.0230 .1 | 782.5617 | .9 | 795.9317 | .7 | 809.3016 .2 | 782.8403 |13.0 | 796.2102 | .8 | 809.5801 .3 | 783.1188 | .1 | 796.4887 | .9 | 809.8587 .4 | 783.3974 | .2 | 796.7673 |18.0 | 810.1372 .5 | 783.6959 | .3 | 797.0458 | .1 | 810.4175 .6 | 783.9544 | .4 | 797.3244 | .2 | 810.6943 .7 | 784.2330 | .5 | 797.6029 | .3 | 810.9728 .8 | 784.5115 | .6 | 797.8814 | .4 | 811.2514 .9 | 784.7901 | .7 | 798.1600 | .5 | 811.5299 9.0 | 785.0686 | .8 | 798.4385 | .6 | 811.8084 .1 | 785.3471 | .9 | 798.7171 | .7 | 812.0870 .2 | 785.6257 |14.0 | 798.9956 | .8 | 812.3655 .3 | 785.9042 | .1 | 799.2741 | .9 | 812.6441 .4 | 786.1828 | .2 | 799.5527 |19.0 | 812.9226 .5 | 786.4613 | .3 | 799.8312 | .1 | 813.2011 .6 | 786.7398 | .4 | 800.1098 | .2 | 813.4797 .7 | 787.0184 | .5 | 800.3883 | .3 | 813.7582 .8 | 787.2969 | .6 | 800.6668 | .4 | 814.0368 _____|_____________|_____|_____________|_____|_____________ ___________________________________________________________ | | | | | t. | 760x(1+dt). | t. | 760x(1+dt). | t. | 760x(1+dt). _____|_____________|_____|_____________|_____|_____________ | | | | | °C. | | °C. | | °C. | 19.5 | 814.3153 |23.0 | 824.0642 | .5 | 833.8131 .6 | 814.5938 | .1 | 824.3427 | .6 | 834.0916 .7 | 814.8724 | .2 | 824.6213 | .7 | 834.3702 .8 | 815.1500 | .3 | 824.8998 | .8 | 834.6487 .9 | 815.4925 | .4 | 825.1784 | .9 | 834.9273 20.0 | 815.7080 | .5 | 825.4569 |27.0 | 835.2058 .1 | 815.9865 | .6 | 825.7354 | .1 | 835.4843 .2 | 816.2651 | .7 | 826.0140 | .2 | 835.7629 .3 | 816.5436 | .8 | 826.2925 | .3 | 836.0414 .4 | 816.8222 | .9 | 826.5711 | .4 | 836.3200 .5 | 817.1007 |24.0 | 826.8496 | .5 | 836.5985 .6 | 817.3792 | .1 | 827.1281 | .6 | 836.8770 .7 | 817.6578 | .2 | 827.4067 | .7 | 837.1556 .8 | 817.9363 | .3 | 827.6852 | .8 | 837.4341 .9 | 818.2149 | .4 | 827.9638 | .9 | 837.7127 21.0 | 818.4934 | .5 | 828.2423 |28.0 | 837.9912 .1 | 818.7719 | .6 | 828.5208 | .1 | 838.2697 .2 | 819.0505 | .7 | 828.7994 | .2 | 838.5483 .3 | 819.3290 | .8 | 829.0779 | .3 | 838.8268 .4 | 819.6076 | .9 | 829.3565 | .4 | 839.1054 .5 | 819.8861 |25.0 | 829.6350 | .5 | 839.3839 .6 | 820.1646 | .1 | 829.9135 | .6 | 839.6624 .7 | 820.4432 | .2 | 830.1921 | .7 | 839.9410 .8 | 820.7217 | .3 | 830.4706 | .8 | 840.2195 .9 | 821.0003 | .4 | 830.7492 | .9 | 840.4981 22.0 | 821.2788 | .5 | 831.0277 |29.0 | 840.7766 .1 | 821.5573 | .6 | 831.3062 | .1 | 841.0551 .2 | 821.8859 | .7 | 831.5848 | .2 | 841.3337 .3 | 822.1144 | .8 | 831.8633 | .3 | 841.6122 .4 | 822.3930 | .9 | 832.1419 | .4 | 841.8908 .5 | 822.6715 |26.0 | 832.4204 | .5 | 842.1693 .6 | 822.9500 | .1 | 832.6989 | .6 | 842.4478 .7 | 823.2286 | .2 | 832.9775 | .7 | 842.7264 .8 | 823.5071 | .3 | 833.2560 | .8 | 843.0049 .9 | 823.7857 | .4 | 833.5346 | .9 | 843.2835 | | | |30.0 | 843.5620 _____|_____________|_____|_____________|_____|_____________ CHAPTER VIII. _FIRING POINT OF EXPLOSIVES, HEAT TESTS, &c._ Horsley's Apparatus--Table of Firing points--The Government Heat-Test Apparatus for Dynamites--Nitro-Glycerine, Nitro-Cotton, and Smokeless Powders--Liquefaction and Exudation Tests--Page's Regulator for Heat-Test Apparatus--Specific Gravities of Explosives--Table of Temperature of Detonation, Sensitiveness, &c. ~The Firing Point of Explosives.~--The firing point of an explosive may be determined as follows:--A copper dish, about 3 inches deep, and 6 or more wide, and fitted with a lid, also of copper, is required. The lid contains several small holes, into each of which is soldered a thick copper tube about 5 mm. in diameter, and 3 inches long, with a rather larger one in the centre in which to place a thermometer. The dish is filled with Rose's metal, or paraffin, according to the probable temperature required. The firing point is then taken thus:--After putting a little piece of asbestos felt at the bottom of the centre tube, the thermometer is inserted, and a small quantity of the explosive to be tested is placed in the other holes; the lid is then placed on the dish containing the melted paraffin or metal, in such a way that the copper tubes dip below the surface of the liquid; the temperature of the bath is now raised until the explosive fires, and the temperature noted. The initial temperature should also be noted. THE FIRING POINT OF VARIOUS EXPLOSIVES (by C. E. Munroe). (Horsley's Apparatus used.) _____________________________________________________________________ | | °C. Nitro-glycerine, 5 years old (a single drop taken) | 203-205 Gun-cotton (compressed military cotton, sp. gr. 1.5) | 192-201 Air-dried gun-cotton, stored for 4 years | 179-187 Ditto, stored for 1 year | 187-189 Air-dried collodion-cotton, long staple "Red Island | cotton," 3 years old | 186-191 Air-dried collodion, 3 years old, stored wet | 197-199 Hydro-nitro-cellulose | 201-213 Kieselguhr dynamite, No. 1 | 197-200 Explosive gelatine | 203-209 Mercury fulminate | 175-181 Gunpowder (shell) | 278-287 Hill's picric powder (shells) Been in store 10 years. | 273-283 Ditto (musket) Composed of-- | 282-290 Ammonium picrate 42.18 % | Potassium picrate 53.79 " | Charcoal (alder) 3.85 " | ________ | | 99.82 | Forcite, No. 1 | 187-200 Atlas powder (75% NG) | 175-185 Emmensite, No. 1 Sample had been stored in | 167-184 magazine for some months in | a wooden box. | " No. 2 Stored in tin case. | 165-177 " No. 5 " " | 205-217 __________________________________________________________|__________ | | | °C. | Powder used in Chassepôt rifle | 191 | By Leygue & Champion. French gunpowder | 295 | " " Rifle powder (picrate) | 358 | " " Cannon | 380 | " " __________________________________|_________|________________________ Horsley's apparatus consists of an iron stand with a ring support, holding a hemispherical iron vessel or bath in which solid paraffin is put. Above this is another movable support, from which a thermometer is suspended, and so adjusted that its bulb is immersed in the material contained in the iron vessel. A thin copper cartridge-case, 5/8 inch in diameter and 1-15/16 inch long, is suspended over the bath by means of a triangle, so that the end of the case is just 1 inch below the surface of the molten material. On beginning the experiment of determining the firing point of any explosive, the material in the bath is heated to just above the melting point; the thermometer is inserted in it, and a minute quantity of the explosive is placed in the bottom of the cartridge-case. The initial temperature is noted, and then the cartridge-case containing the explosive is inserted in the bath. The temperature is quickly raised until the contents of the cartridge-case flash off or explode, when the temperature is noted as the _firing point_. [Illustration: FIG. 46.--HEAT TEST APPARATUS.] Professor C.E. Munroe, of the U.S. Torpedo Station, has determined the firing point of several explosives by means of this apparatus. ~The Government Heat Test (Explosives Act, 1875): Apparatus required.~--A water bath, consisting of a spherical copper vessel _(a)_, Fig. 46, of about 8 inches diameter, and with an aperture of about 5 inches; the bath is filled with water to within a quarter of an inch of the edge. It has a loose cover of sheet copper about 6 inches in diameter _(b)_ and rests on a tripod stand about 14 inches high _(c)_, which is covered with coarse wire gauze _(e)_, and is surrounded with a screen of thin sheet copper _(d)_. Within the latter is placed an argand burner _(f)_ with glass chimney. The cover _(b)_ has four holes arranged, as seen in Fig. II., No. 4 to contain a Page's[A] or Scheibler's regulator, No. 3 the thermometer, Nos. 1 and 2 the test tubes containing the explosive to be tested. Around the holes 1 and 2 on the under side of the cover are soldered three pieces of brass wire with points slightly converging (Fig. III.); these act as springs, and allow the test tubes to be easily placed in position and removed. [Footnote A: See _Chem. Soc. Jour._, 1876, i. 24. F.J.M. Page.] ~Test Tubes~, from 5-1/4 to 5-1/2 inches long, and of such a diameter that they will hold from 20 to 22 cubic centimetres of water when filled to a height of 5 inches; rather thick glass is preferable. Indiarubber stoppers, fitting the test tubes, and carrying an arrangement for holding the test papers, viz., a narrow glass tube passing through the centre of the stopper, and terminating in a platinum wire hook. A glass rod drawn out and the end turned up to form a hook is better. ~The Thermometer~ should have a range from 30° to 212° F., or from 1° to 100° C. A minute clock is useful. ~Test Paper.~--The test paper is prepared as follows:--45 grains (2.9 grms.) of white maize starch (corn flour), previously washed with cold water, are added to 8-1/2 oz. of water. The mixture is stirred, heated to boiling, and kept gently boiling for ten minutes; 15 grains (1 grm.) of pure potassium iodide (previously recrystallised from alcohol, absolutely necessary) are dissolved in 8-1/2 oz. of distilled water. The two solutions are thoroughly mixed and allowed to get cold. Strips or sheets of white English filter paper, previously washed with water and re-dried, are dipped into the solution thus prepared, and allowed to remain in it for not less than ten seconds; they are then allowed to drain and dry in a place free from laboratory fumes and dust. The upper and lower margins of the strips or sheets are cut off, and the paper is preserved in well- stoppered or corked bottles, and in the dark. The dimensions of the pieces of test paper used are about 4/10 inch by 8/10 inch (10 mm. by 20 mm.).[A] [Footnote A: When the paper is freshly prepared, and as long as it remains in good condition, a drop of diluted acetic acid put on the paper with a glass rod produces no coloration. In process of time it will become brownish, when treated with the acid, especially if it has been exposed to sunlight. It is then not fit for use.] In Germany zinc-iodide starch paper is used, which is considered to be more sensitive than potassium iodide. ~Standard Tint Paper.~--A solution of caramel in water is made of such concentration that when diluted one hundred times (10 c.c. made up to 1 litre) the tint of this diluted solution equals the tint produced by the Nessler test in 100 c.c. water containing .000075 grm. of ammonia, or .00023505 grm. AmCl. With this caramel solution lines are drawn on strips of white filter paper (previously well washed with distilled water, to remove traces of bleaching matter, and dried) by means of a quill pen. When the marks thus produced are dry, the paper is cut into pieces of the same size as the test paper previously described, in such a way that each piece has a brown line across it near the middle of its length, and only such strips are preserved in which the brown line has a breadth varying from 1\2 mm. to 1 mm. (1/50 of an inch to 1/25 of an inch). ~Testing Dynamite, Blasting Gelatine, and Gelatine Dynamite.~--Nitro- glycerine preparations, from which the nitro-glycerine can be extracted in the manner described below, must satisfy the following test, otherwise they will not be considered as manufactured with "thoroughly purified nitro-glycerine," viz., fifteen minutes at 160° F. (72° C.). ~Apparatus required.~--A funnel 2 inches across (_d_), a cylindrical measure divided into grains (_e_), Fig. 47. ~Mode of Operation.~--About 300 (19.4 grms.) to 400 grains (26 grms.) of dynamite (_b_), finely divided, are placed in the funnel, which is loosely plugged by freshly ignited asbestos (_a_). The surface is smoothed by means of a flat-headed glass rod or stopper, and some clean washed and dried kieselguhr (_c_) is spread over it to the depth of about 1/8 inch. Water is then poured on from a wash bottle, and when the first portion has been soaked up more is added; this is repeated until sufficient nitro- glycerine has collected in the graduated measure (_e_). If any water should have passed through, it must be removed from the nitro-glycerine by filter paper, or the nitro-glycerine may be filtered. [Illustration: FIG. 47.--APPARATUS FOR SEPARATING THE NlTRO-GLYCERINE FROM DYNAMITE.] [Illustration: FIG. 48.--TEST TUBE ARRANGED FOR HEAT TEST.] ~Application of Test.~--The thermometer is fixed so as to be inserted through the lid of the water bath into the water, which is maintained at 160° F. (72° C.), to a depth of 2-3/4 inches. Fifty grains (= 3.29 grms.) of nitro-glycerine to be tested are weighed into the test tube, in such a way as not to soil the sides of the tube (use a pipette). A test paper is fixed on the hook of the glass rod, so that when inserted into the tube it will be in a vertical position. A sufficient amount of a mixture of half distilled water and half glycerine, to moisten the upper half of the paper, is now applied to the upper edge of the test paper by means of a glass rod or camel's hair pencil; the cork carrying the rod and paper is fixed into the test tube, and the position of the paper adjusted so that its lower edge is about half way down the tube; the latter is then inserted through one of the holes in the cover to such a depth that the lower margin of the moistened part of the paper is about 5/8 inch above the surface cover. The test is complete when the faint brown line, which after a time makes its appearance at the line of boundary between the dry and moist part of the paper, equals in tint the brown line of the standard tint paper. ~Blasting Gelatine, Gelatine Dynamite, Gelignite, &c.~--Fifty grains (= 3.29 grms.) of blasting gelatine are intimately mixed with 100 grains (= 6.5 grms.) of French chalk. This is done by carefully working the two materials together with a wooden pestle in a wooden mortar. The mixture is then gradually introduced into the test tube, with the aid of gentle tapping upon the table between the introduction of successive portions of the mixture into the tube, so that when the tube contains all the mixture it shall be filled to the extent of 1-3/4 inch of its height. The test paper is then inserted as above described for nitro-glycerine. The sample tested must stand a temperature of 160° F. for a period of ten minutes before producing a discoloration of the test paper corresponding in tint to the standard paper. _N.B._--Non-gelatinised nitro-glycerine preparations, from which the nitro-glycerine cannot be expelled by water, are tested without any previous separation of the ingredients, the temperature being as above 160° F., and the time being seven minutes. ~Gun-Cotton, Schultze Gunpowder, E.C. Powder, &c.: A. Compressed Gun- Cotton.~--Sufficient material to serve for two or more tests is removed from the centre of the cartridge by gentle scraping, and if necessary, further reduced by rubbing between the fingers. The fine powder thus produced is spread out in a thin layer upon a paper tray 6 inches by 4-1/2 inches, which is then placed inside a water oven, kept as nearly as possible at 120° F. (49° C.). The wire gauze shelves of the oven should be about 3 inches apart. The sample is allowed to remain at rest for fifteen minutes in the oven, the door of which is left wide open. After the lapse of fifteen minutes the tray is removed and exposed to the air of the room for two hours, the sample being at some point within that time rubbed upon the tray with the hand, in order to reduce it to a fine and uniform state of division. The heat test is performed as before, except that the temperature of the bath is kept at 170° F. (66° C.), and regulator set to maintain that temperature. Twenty grains (1.296 grm.) are used, placed in the test tube, gently pressed down until it occupies a space of as nearly as possible 1-5/10 inch in the test tube of dimensions previously specified. The fine cotton adhering to the sides of the tube can be removed by a clean cloth or silk handkerchief. The paper is moistened by touching the upper edge with a drop of the 50 per cent. glycerine solution, the tube inserted in the bath to a depth of 2-1/2 inches, measured from the cover, the regulator and thermometer being inserted to the same depth. The test paper is to be kept near the top of the test tube, but clear of the cork, until the tube has been immersed for about five minutes. A ring of moisture will about this time be deposited upon the sides of the test tube, a little above the cover of the bath. The glass rod must then be lowered until the lower margin of the moistened part of the paper is on a level with the bottom of the ring of moisture in the tube. The paper is now closely watched, The test is complete when a very faint brown coloration makes its appearance at the line of boundary between the dry and moist parts of the paper. It must stand the test for not less than ten minutes at 170° F. (The time is reckoned from the first insertion of the tube in the bath until the appearance of a discoloration of the test paper.) ~B. Schultze Powder, E.C. Powder, Collodion-Cotton, &c.~--The sample is dried in the oven as above for fifteen minutes, and exposed for two hours to the air. The test as above for compressed gun-cotton is then applied. ~C. Cordite~ must stand a temperature of 180° F. for fifteen minutes. The sample is prepared as follows:--Pieces half an inch long are cut from one end of every stick selected for the test: in the case of the thicker cordites, each piece so cut is further subdivided into about four portions. These cut pieces are then passed once through the mill, the first portion of material which passes through being rejected on account of the possible presence of foreign matter from the mill. The ground material is put on the top sieve of the nest of sieves, and sifted. That portion which has passed through the top sieve and been stopped by the second is taken for the test. If the mill is properly set, the greater portion of the ground material will be of the proper size. If the volatile matter in the explosive exceeds 0.5 per cent., the sifted material should be dried at a temperature not exceeding 140° F, until the proportion does not exceed 0.5 per cent. After each sample has been ground, the mill must be taken to pieces and carefully cleaned. The sieves used consist of a nest of two sieves with holes drilled in sheet copper. The holes in the top sieve have a diameter = 14 B.W.G., those in the second = 21 B.W.G. If too hard for the mill, the cordite may be softened by exposure to the vapour of acetone,[A] or reduced, to the necessary degree of subdivision by means of a sharp moderately-coarse rasp. Should it have become too soft in the acetone vapour for the mill, it should be cut up into small pieces, which may be brought to any desired degree of hardness by simple exposure to air. Explosives which consist partly of gelatinised collodion-cotton, and partly of ungelatinised gun-cotton, are best reduced to powder by a rasp, or softened by exposure to mixed ether and alcohol vapour at a temperature of 40° F. to 100° F. [Footnote A: Mr W. Cullen _(Jour. Soc. Chem. Ind._, Jan. 31, 1901) says:-- "Undoubtedly the advent of the horny smokeless powders of modern times has made it a little difficult to give the test the same scope as it had when first introduced." As a rule a simple explanation can be found for every apparently abnormal result, and in the accidental retention of a portion of the solvent used in the manufacture, will frequently be found an explanation of the trouble experienced.] ~Ballistite.~--In the case of ballistite the treatment is the same, except that when it is in a very finely granulated condition it need not be cut up. ~Guttmann's Heat Test.~--This test was proposed by Mr Oscar Guttmann in a paper read before the Society of Chemical Industry (vol. xvi., 1897), in the place of the potassium iodide starch paper used in the Abel test. The filter paper used is wetted with a solution of diphenylamine[A] in sulphuric acid. The solution is prepared as follows:--Take 0.100 grm. of diphenylamine crystals, put them in a wide-necked flask with a ground stopper, add 50 c.c. of dilute sulphuric acid (10 c.c. of concentrated sulphuric acid to 40 c.c. of water), and put the flask in a water bath at between 50° and 55° C. At this temperature the diphenylamine will melt, and at once dissolve in the sulphuric acid, when the flask should be taken out, well shaken, and allowed to cool. After cooling, add 50 c.c. of Price's double distilled glycerine, shake well, and keep the solution in a dark place. The test has to be applied in the following way:--The explosives that have to be tested are finely subdivided, gun-cotton, nitro-glycerine, dynamite, blasting gelatine, &c., in the same way as at present directed by the Home Office regulations. Smokeless powders are all to be ground in a bell-shaped coffee mill as finely as possible, and sifted as hitherto. 1.5 grm. of the explosive (from the second sieve in the case of smokeless powder) is to be weighed off and put into a test tube as hitherto used. Strips of well-washed filter paper, 25 mm. wide, are to be hung on a hooked glass rod as usual. A drop of the diphenylamine solution is taken up by means of a clean glass rod, and the upper corners of the filter paper are touched with it, so that when the two drops run together about a quarter of the filter paper is moist. This is then put into the test tube, and this again into the water bath, which has been heated to 70° C. The heat test reaction should not show in a shorter time than fifteen minutes. It will begin by the moist part of the paper acquiring a greenish yellow colour, and from this moment the paper should be carefully watched. After one or two minutes a dark blue mark will suddenly appear on the dividing line between the wet and dry part of the filter paper, and this is the point that should be taken. [Footnote A: Dr G. Spica (_Rivista_, Aug. 1897) proposes to use hydrochloride of meta-phenylenediamine.] ~Exudation and Liquefaction Test for Blasting Gelatine, Gelatine Dynamite, &c.~--A cylinder of blasting gelatine, &c., is to be cut from the cartridge to be tested, the length of the cylinder to be equal to its diameter, and the ends being cut flat. The cylinder is to be placed on end on a flat surface without any wrapper, and secured by a pin passing vertically through its centre. In this condition the cylinder is to be exposed for 144 consecutive hours (six days and nights) to a temperature ranging from 85° to 90° F. (inclusive), and during such exposure the cylinder shall not diminish in height by more than one-fourth of its original height, and the upper cut surface shall retain its flatness and the sharpness of its edge. ~Exudation Test.~--There shall be no separation from the general mass of the blasting gelatine or gelatine dynamite of a substance of less consistency than the bulk of the remaining portion of the material under any conditions of storage, transport, or use, or when the material is subjected three times in succession to alternate freezing and thawing, or when subjected to the liquefaction test before described. ~Picric Acid.~--The material shall contain not more than 0.3 part of mineral or non-combustible matter in 100 parts by weight of the material dried at 160° F. It should not contain more than a minute trace of lead. One hundred parts of the dry material shall not contain more than 0.3 part of total (free and combined) sulphuric acid, of which not more than 0.1 part shall be free sulphuric acid. Its melting point should be between 248° and 253° F. ~Ammonite, Bellite, Roburite, and Explosives of similar Composition.~-- These are required to stand the same heat test as compressed nitro-cellulose, gun-cotton, &c. ~Chlorate Mixtures.~--The material must not be too sensitive, and must show no tendency to increase in sensitiveness in keeping. It must contain nothing liable to reduce the chlorate. Chlorides calculated as potassium chloride must not exceed 0.25 per cent. The material must contain no free acid, or substance liable to produce free acid. Explosives of this class containing nitro-compounds will be subject to the heat test. ~Page's Regulator.~--The most convenient gas regulator to use in connection with the heat-test apparatus is the one invented by Prof. F.J.M. Page, B.Sc.[A] (Fig. 49). It is not affected by variations of the barometric pressure, and is simple and easy to fit up. It consists of a thermometer with an elongated glass bulb 5/8 inch diameter and 3 inches long. The stem of the thermometer is 5 inches long and 1/8 inch to 3/16 inch internal diameter. One and a half inch from the top of the stem is fused in at right angles a piece of glass tube, 1 inch long, of the same diameter as the stem, so as to form a T. A piece of glass tube (A), about 7/16 inch external diameter and 1-1/2 inch long, is fitted at one end with a short, sound cork (C, Fig. 50). Through the centre of this cork a hole is bored, so that the stem of the thermometer just fits into it. The other end of this glass tube is closed by a tightly fitting cork, preferably of indiarubber (I), which is pierced by a fine bradawl through the centre. Into the hole thus made is forced a piece of fine glass tube (B) 3 inches long, and small enough to fit loosely inside the stem of the thermometer. [Footnote A: _Chemical Soc. Jour._, 1876, i. 24.] The thermometer is filled by pouring in mercury through a small funnel until the level of the mercury (when the thermometer is at the desired temperature) is about 1-1/2 inch below the T. The piece of glass tube A, closed at its upper extremity by the cork I, through which the fine glass tube B passes into the stem of the thermometer, is now filled by means of the perforated cork at its lower extremity on the stem of the thermometer. The gas supply tube is attached to the top of the tube A, the burner to the T, so that the gas passes in at the top, down the fine tube B, rises in the space between B and the inside wall of the stem of the thermometer, and escapes by the T. The regulator is set for any given temperature by pushing the cork C, and consequently the tubes A and B, which are firmly attached to it, up or down the stem of the thermometer, until the regulator just cuts off the gas at the desired temperature. [Illustration: FIG. 49.--PAGE'S REGULATOR.] [Illustration: FIG. 50.--PAGE'S GAS REGULATOR, SHOWING BYE-PASS AND CUT-OFF ARRANGEMENT.] As soon as the temperature falls, the mercury contracts, and thus opens the end of the tube B. The gas is thus turned on, and the temperature rises until the regulator again cuts off the gas. In order to prevent the possible extinction of the flame by the regulator, the brass tube which carries the gas to the regulator is connected with the tube which brings the gas from the regulator to the burner by a small brass tap (Fig. 2). This tap forms an adjustable bye-pass, and thus a small flame can be kept burning, even though the regulator be completely shut off. It is obvious that the quantity of gas supplied through the bye-pass must always be less than that required to maintain the desired temperature. This regulator, placed in a beaker of water on a tripod, will maintain the temperature of the water during four or five hours within 0.2° C., and an air bath during six weeks within 0.5° C. To sum up briefly the method of using the regulator:--Being filled with mercury to about 1\2 inch below the T, attach the gas supply as in diagram (Fig. 2), the brass tap being open, and the tube B unclosed by the mercury. Allow the gas to completely expel the air in the apparatus. Push down the tube A so that the end of B is well under the surface of the mercury. Turn off the tap of the bye-pass until the smallest bead of flame is visible. Raise A and B, and allow the temperature to rise until the desired point is attained. Then push the tubes A and B slowly down until the flame is just shut off. The regulator will then keep the temperature at that point. ~Will's Test for Nitro-Cellulose.~--The principle of Dr W. Will's test[A] may be briefly described as follows:--The regularity with which nitro- cellulose decomposes under conditions admitting of the removal of the products of decomposition immediately following their formation is a measure of its stability. As decomposing agent a sufficiently high temperature (135° C.) is employed, the explosive being kept in a constantly changing atmosphere of carbon dioxide, heated to the same temperature: the oxides of nitrogen which result are swept over red-hot copper, and are then reduced to nitrogen, and finally, the rates of evolution of nitrogen are measured and compared. Dr Will considers that the best definition and test of a stable nitro-cellulose is that it should give off at a high temperature equal quantities of nitrogen in equal times. For the purposes of manufacture, it is specially important that the material should be purified to its limit, i.e., the point at which further washing produces no further change in its speed of decomposition measured in the manner described. [Footnote A: W. Will, _Mitt. a. d. Centrallstelle f. Wissench. Techn. Untersuchungen Nuo-Babelsberg Berlin_, 1902 [2], 5-24.] The sample of gun-cotton (2.5 grms.) is packed into the decomposition tube 15 mm. wide and 10 cm. high, and heated by an oil bath to a constant temperature, the oxides so produced are forced over ignited copper, where they are reduced, and the nitrogen retained in the measuring tubes. Care must be taken that the acid decomposition products do not condense in any portion of the apparatus. The air in the whole apparatus is first displaced by a stream of carbon dioxide issuing from a carbon dioxide generator, or gas-holder, and passing through scrubbers, and this stream of gas is maintained throughout the whole of the experiment, the gas being absorbed at the end of the system by strong solution of caustic potash. To guard against the danger of explosions, which occasionally occur, the decomposition tube and oil bath are surrounded by a large casing with walls composed of iron plate and strong glass. Dr Will's apparatus has been modified by Dr Robertson,[A] of the Royal Gunpowder Factory, Waltham Abbey. The form of the apparatus used by him is shown in Fig. 51. ~CO_{2} Holders.~--Although objection has been taken to the use of compressed CO_{2} in steel cylinders on account of the alleged large and variable amount of air present, it has, nevertheless, been found possible to obtain this gas with as little as 0.02 per cent. of air. Frequent estimations of the air present in the CO_{2} of a cylinder show that even with the commercial article, after the bulk of the CO_{2} has been removed, the residual gas contains only a very small amount of air, which decreases in a gradual and perfectly regular manner. For example, one cylinder which gave 0.03 per cent. of air by volume, after three months' constant use gave 0.02 per cent. The advantage of using CO_{2} from this source is obvious when compared with the difficulty of evolving a stream of gas of constant composition from a Kipps or Finkener apparatus. A micrometer screw, in addition to the main valve of the CO_{2} cylinder, is useful for governing the rate of flow. A blank experiment should be made to ascertain the amount of air in the CO_{2} and the correction made in the readings afterwards. [Footnote A: _Jour. Soc. Chem. Ind._, June 30, 1902, p. 819.] [Illustration: Fig 51.--Will's Apparatus for Testing Nitro-cellulose] ~Measurement of Pressure and Rate of Flow.~--Great attention is paid to the measurement of the rate of flow of gas, which is arrived at by counting with a stop-watch the number of bubbles of gas per minute in a small sulphuric acid wash bottle. A mercury manometer is introduced here, and is useful for detecting a leak in the apparatus. The rate of flow that gives the most satisfactory results is 1,000 c.c. per hour. If too rapid it does not become sufficiently preheated in the glass spiral, and if too slow there is a more rapid decomposition of the nitro-cellulose by the oxides of nitrogen which are not removed. ~Decomposition Tube.~--This is of the form and dimensions given by Dr Will (15 mm. wide and 10 cm. high), the preheating worm being of the thinnest hydrometer stem tubing. The ground-in exit tube is kept in position by a small screw clamp with trunnion bearings. ~Bath.~--To permit of two experiments being carried on simultaneously, the bath is adapted for two decomposition tubes, and is on the principle of Lothar Meyer's air bath, that is, the bath proper filled with a high- flashing hydrocarbon oil, and fitted with a lid perforated with two circular holes for the spiral tubes, is surrounded by an asbestos-covered envelope, in the interior of which circulate the products of combustion of numerous small gas jets. The stirrer, agitated by a water motor, or, better still, a hot-air engine, has a series of helical blades curved to give a thorough mixing to the oil. Great uniformity and constancy of temperature are thus obtained. The bath is fitted also with a temperature regulator and thermometer. ~Reduction Tube~--This is of copper, and consists of two parts, the outer tube and an inner reaching to nearly the bottom of the former. Into the inner tube fits a spiral of reduced copper gauze, and into the annular space between the tubes is fitted a tightly packed reduced copper spiral. At the bottom the inlet tube dips into a layer of copper oxide asbestos, on the top of which is a layer of reduced copper asbestos. Through the indiarubber cork passes a glass tube, which leads the CO_{2} and nitrogen out of the reduction tube. As the portion of the tube containing the spirals is heated to redness, water jackets are provided on both inner and outer tubes to protect the indiarubber cork. ~Nitrogen Measuring Apparatus.~--The measuring tube with zigzag arrangement is used, having been found very economical in potash. It is most convenient to take readings by counterbalancing the column of potash solution and reading off the volume of gas at atmospheric pressure. For this purpose the tap immediately in front of the measuring tube is momentarily closed, this having been proved to be without ill effect on the progress of the test. In all experiments done by this test the air correction is subtracted from each reading, and the remainder brought to milligrams of nitrogen with the usual corrections. As objection has frequently been taken to the test on the ground of difficulty in interpreting the results obtained, Dr Robertson made a series of experiments for the purpose of standardising the test, and at the same time of arriving at the condition under which it could be applied in the most sensitive and efficient manner. A variety of nitro-celluloses having been tested, there were chosen as typical, of stable and unstable products, service gun-cotton on the one hand, and an experimental gun- cotton, Z, on the other. The first point brought out by these experiments was the striking uniformity of service gun-cotton, first in regard to the rectilinear nature of the curve of evolution of nitrogen, and secondly in regard to the small range within which a large number of results is included, 15 samples lying between 6.6 and 8.7 mgms. of nitrogen evolved in four hours. In the case of service gun-cotton, little difference in the rate of evolution of nitrogen evolved is obtained on altering the rate of passage of CO_{2} gas through the wide range of 500 c.c. per hour to 2,500 c.c. per hour. With Z gun-cotton (see Fig. 52), however, the case is very different. Operating at a rate of 1,000 c.c. of CO_{2} per hour, a curve of nitrogen evolution is obtained, which is bent and forms a good representation of the inherent instability of the material as proved to exist from other considerations. Operating at the rate of 1,500 c.c. per hour, as recommended by Dr Will, the evolution of nitrogen is represented by a straight line, steeper, however, than that of service gun-cotton. The rate of passage of CO_{2} was therefore chosen at 1,000 c.c. per hour, or two-thirds of the rate of Dr Will, and this rate, besides possessing the advantage claimed of rendering diagnostic the manner of nitrogen evolution in Z gun-cotton, has in other cases been useful in bringing out relationships, which the higher rate would have entirely masked. [Illustration: Fig. 52.--Dr. Robertson's results.] [Illustration: Fig. 53.--Service Guncotton for Cordite made at a Private Factory.] Readings are taken thirty minutes from the time the nitro-cellulose is heated, and are taken at intervals of fifteen minutes for about four hours; fresh caustic potash is added every thirty minutes or so. It is convenient to plot the results in curves. The curves given in Fig. 53 are from gun-cotton manufacturers in England at a private factory. The rate of evolution of nitrogen is as follows:-- In 1 hour. In 2 hours. In 3 hours. In 4 hours. N. N. N. N. in milligrammes. 1.25 2.55 4.5 5.75 1.5 3.25 5.25 6.75 These results are very satisfactory, the gun-cotton was of a very good quality. Several hours are necessary to remove all the air from the apparatus. Dr Will stated fifteen minutes in his original paper, but this has not been found sufficient. It has not been satisfactorily proved that Will's test can be applied to gelatinised nitro-cellulose powders. It is convenient to plot the results in curves; the nitrogen is generally given in cubic centimetres or in milligrammes, and readings taken every fifteen minutes. The steepness of the curve is a measure of the stability of the nitro-cellulose which is being examined. The steeper the curve the more nitrogen is evolved per unit of time, and the less stable the nitro- cellulose. In the case of unstable nitro-celluloses heated under the conditions described, the separation of nitrogen is much greater at first than at a later period. If the nitro-cellulose be very unstable, explosions are produced. If the separation of nitrogen is uniform during the prolonged heating, then the nitro-cellulose may be regarded as "normal." If it be desired to determine the absolute amount of nitrogen separated from a nitro-cellulose, the following conditions must be observed:--(1.) Accurate weighing of the nitro-cellulose; (2.) Determination of the amount of air in the CO_{2}, and deduction of this from the volume of gas obtained; (3.) Reduction of the volume of the gas to the volume at 0° C. and 760 mm. pressure.[A] [Footnote A: See also _Jour. Soc. Chem. Ind._, Dec. 1902, pages 1545-1555, on the "Stability of Nitro-cellulose" and "Examination of Nitro- cellulose," Dr Will.] ~Bergrnann and Junk~[A] describe a test for nitro-cellulose that has been in use in the Prussian testing station for some years. The apparatus consists of a closed copper bath provided with a condenser and 10 countersunk tubes of 20 cm. length. By boiling amyl-alcohol in the bath, the tubes can be kept at a constant temperature of 132° C. The explosive to be tested is placed in a glass tube 35 cm. long and 2 cm. wide, having a ground neck into which an absorption bulb is fitted. The whole apparatus is surrounded by a shield, in case of explosion. In carrying out the test, 2 grms. of the explosive are placed in the glass tube and well pressed down. The absorption bulb is half filled with water, and fitted into the ground neck of the glass tube, which is then placed in one of the tubes in the bath previously brought to the boiling point (132° C.). The evolved oxides of nitrogen are absorbed in the water in the bulb, and at the end of two hours the tubes are removed from the bath, and on cooling, the water from the bulb flows back and wets the explosive. The contents of the tube are filtered and washed, the filtrate is oxidised with permanganate, and the nitrogen determined as nitric oxide by the Schultze-Tieman method. The authors conclude that a stable gun-cotton does not evolve more than 2.5 c.c. of nitric oxide per grm. on being heated to 132° C. for two hours, and a stable collodion-cotton not more than 2 c.c. under the same conditions. The percentage of moisture in the sample to be tested should be kept as low as possible. A sample of nitro-cellulose containing 1.97% of moisture gave an evolution of 2.6 c.c. per grm., while the same sample with 3.4% moisture gave an evolution of over 50 c.c. per grm. Sodium carbonate added to an unstable nitro-cellulose diminishes the rate of decomposition, but if sodium carbonate be intimately mixed with a stable nitro-cellulose the rate of decomposition will be increased. Calcium carbonate and mercury chloride have no influence. If an unstable nitro- cellulose be extracted with alcohol a stable compound is produced. The percentage solubility of a nitro-cellulose in ether-alcohol rises on heating to 132° C. A sample which before heating had a solubility of 4.7% had its solubility increased to 82.5% after six hours' heating. [Footnote A: _Jour. Soc. Chem. Ind._, xxiii., Oct. 15, 1904, p. 953.] Mr A.P. Sy (_Jour. Amer. Chem. Soc._, 1903) describes a new stability test for nitro-cellulose which he terms "The Elastic Limit of Powder Resistance to Heat." The test consists in heating the powder on a watch glass in an oven to a temperature of 115° C., after eight hours the watch glass and powder are weighed and the process repeated daily for six days or less. He claims that the powder is tested in its natural state, all the products of decomposition are taken into account, whilst in the old tests only the acid products are shown, and in the Will test only nitrogen, that it affords an indication of the effect of small quantities of added substances or foreign matters on the stability and that it is simple, and not subject to the variations of the old tests. Obermüller (_Jour. Soc. Chem. Ind._, April 15, 1905) considers Bergmann and Junk's test is too complicated and occupies too much time; he proposes to heat gun-cotton to 140° C. _in vacuo_, and to measure continuously by means of a mercury manometer the pressure exerted by the evolved gases, the latter being maintained at constant volume; the rate at which the pressure increases is a measure of the rate of decomposition of the nitro- cellulose. SPECIFIC GRAVITIES OF EXPLOSIVES, &C. Nitro-glycerine 1.6 Gun-cotton (dry) 1.06 " (25 per cent. water) 1.32 Dynamite No. 1 1.62 Blasting gelatine 1.54 Gelatine dynamite 1.55 Ballistite 1.6 Forcite 1.51 Tonite 1.28 Roburite 1.40 Bellite 1.2-1.4 Carbo-dynamite 1.5 Turpin's cast picric acid 1.6 Nitro-mannite 1.6 Nitro-starch 1.5 Emmensite 1.8 Mono-nitro-benzene 1.2 Meta-di-nitro-benzene 1.575 at 18° C. Ortho-di-nitro-benzene 1.590 " Para-di-nitro-benzene 1.625 " British gunpowder, E.X.E. 1.80 " " S.B.C. 1.85 Cannonite (powder) 1.60 Celluloid 1.35 Cellulose 1.45 Ammonium nitrate 1.707 Mercury fulminate 4.42 TABLE OF THE TEMPERATURE OF DETONATION. Blasting gelatine 3220° Nitro-glycerine 3170° Dynamite 2940° Gun-cotton 2650° Tonite 2648° Picric acid 2620° Roburite 2100° Ammonia nitrate 1130° RELATIVE SENSITIVENESS TO DETONATION (by Professor C.E. Munroe, U.S. Naval Torpedo Station). __________________________________________________________________________ | | Maximum | | Distance | | at which | | Detonation | | occurred. | | CM. | | | Gun-cotton | 10 | Nitro-glycerine 86.5 nitro-cotton | | 9.5, camphor 4 per cent. Explosive gelatine | 20 | NH_{4}NO_{3} 5 parts, (camphorated) | | C_{6}H_{4}(N0_{3})_{2} 1 part. Judson powder, R.R.P. | 25 | Emmensite (No. 259) | 30 | Rack-a-rock | 32 | KClO_{3} 79 parts, | | C_{6}H_{5}(NO)_{2} 21 parts. Bellite | 50 | Forcite No. 1 | 61 | Kieselguhr dynamite No. 1 | 64 | 75 per cent. nitro-gycerine. Atlas powder No. 1 | 74 | __________________________|____________|_________________________ CHAPTER IX. _DETERMINATION OF THE RELATIVE STRENGTH OF EXPLOSIVES._ Effectiveness of an Explosive--High and Low Explosives--Theoretical Efficiency--MM. Roux and Sarrau's Results--Abel and Noble's--Nobel's Ballistic Test--The Mortar, Pressure, or Crusher Gauge--Lead Cylinders-- The Foot-Pounds Machine--Noble's Pressure Gauge--Lieutenant Walke's Results--Calculation of Pressure Developed by Dynamite and Gun-Cotton-- Macnab's and Ristori's Results of Heat Developed by the Explosion of Various Explosives--Composition of some of the Explosives in Common Use for Blasting, &c. ~The Determination of the Relative Strength of Explosives.~--Explosives may be roughly divided into two divisions, viz., those which when exploded produce a shattering force, and those which produce a propulsive force. Explosives of the first class are generally known as the high explosives, and consist for the most part of nitro compounds, or mixtures of nitro compounds with other substances. Any explosive whose detonation is very rapid is a high explosive, but the term has chiefly been applied to the nitro-explosives. The effectiveness of an explosive depends upon the volume and temperature of the gases formed, and upon the rapidity of the explosion. In the high explosives the chemical transformation is very rapid, hence they exert a crushing of shattering effect. Gunpowder, on the other hand, is a low explosive, and produces a propelling or heaving effect. The maximum work that an explosive is capable of producing is proportionate to the amount of heat disengaged during its chemical transformation. This may be expressed in kilogrammetres by the formula 425Q, where Q is the number of units of heat evolved. The theoretical efficiency of an explosive cannot, however, be expected in practice for many reasons. In the case of blasting rock, for instance:[A]--1. Incomplete combustion of the explosive. 2. Compression and chemical changes induced in the surrounding material operated on. 3. Energy expended in the cracking and heating of the material which is not displaced. 4. The escape of gas through the blast-hole, and the fissures caused by the explosion. The proportion of useful work has been estimated to be from 14 to 33 per cent. of the theoretical maximum potential. [Footnote A: C.N. Hake, Government Inspector of Explosives, Victoria, _Jour. Soc. Chem. Ind._, 1889.] For the purposes of comparison, manufacturers generally rely more upon the practical than the theoretical efficiency of an explosive. These, however, stand in the same relation to one another, as the following table of Messrs Roux and Sarrau will show:-- MECHANICAL EQUIVALENT OF EXPLOSIVES. Theoretical Work Relative in Kilos. Value. Blasting powder (62 per cent. KNO_{3}) 242,335 1.0 Dynamite (75 per cent. nitro-glycerine) 548,250 2.26 Blasting gelatine (92 per cent. nitro-glycerine) 766,813 3.16 Nitro-glycerine 794,563 3.28 Experiments made in lead cylinders give-- Dynamite 1.0 Blasting gelatine 1.4 Nitro-glycerine 1.4 Sir Frederick Abel and Captain W.H. Noble, R.A., have shown that the maximum pressure exerted by gunpowder is equal to 486 foot-tons per lb. of powder, or that when 1 kilo, of the powder gases occupy the volume of 1 litre, the pressure is equal to 6,400 atmospheres; and Berthelot has calculated that every gramme of nitro-glycerine exploded gives 1,320 units of heat. MM. Roux and Sarrau, of the Depôt Centrales des Poudres, Paris, by means of calorimetric determinations, have shown that the following units of heat are produced by the detonation of-- Nitro-glycerine 1,784 heat units. Gun-cotton 1,123 " Potassic picrate 840 " which, multiplied by the mechanical equivalent per unit, gives-- Nitro-glycerine 778 metre tons per kilogramme. Gun-cotton 489 " " Picrate of potash 366 " " ~Nobel's Ballistic Test.~--Alfred Nobel was the first to make use of the mortar test to measure the (ballistic) power of explosives. The use of the mortar for measuring the relative power of explosives does not give very accurate results, but at the same time the information obtained is of considerable value from a practical point of view. The mortar consists of a solid cylinder of cast iron, one end of which has been bored to a depth of 9 inches, the diameter of the bore being 4 inches. At the bottom of the bore-hole is a steel disc 3 inches thick, in which another hole has been bored 3 inches by 2 inches. The mortar (Fig. 54) itself is fitted with trunnions, and firmly fixed in a very solid wooden carriage, which is securely bolted down to the ground. The shot used should weigh 28 lbs., and be turned accurately to fit the bore of the mortar. Down its centre is a hole through which the fuse is put. The following is the method of making an experiment:--A piece of hard wood is turned in the lathe to exactly fit the hole in the steel disc at the bottom of the bore. This wooden cylinder itself contains a small cavity into which the explosive is put. Ten grms. is a very convenient quantity. Before placing in the mortar, a hole may be made in the explosive by means of a piece of glass rod of such a size that the detonator to be used will just fit into it. After placing the wooden cylinder containing the explosive in the cavity at the bottom of the bore, the shot, slightly oiled, is allowed to fall gently down on to it. A piece of fuse about a foot long, and fitted with a detonator, is now pushed through the hole in the centre of the shot until the detonator is embedded in the explosive. The fuse is now lighted, and the distance to which the shot is thrown is carefully measured. The range should be marked out with pegs into yards and fractions of yards, especially at the end opposite to the mortar. The mortar should be inclined at an angle of 45°. In experimenting with this apparatus, the force and direction of the wind will be found to have considerable influence. [Illustration: FIG. 54.--MORTAR FOR MEASURING THE BALLISTIC POWER OF EXPLOSIVES. _A_, Shot; _B_, Steel Disc; _C_, Section of Mortar (Cast Iron); _D_, Wooden Plug holding Explosive (_E_); _F_, Fuse.] Mr T. Johnson made some ballistic tests. He used a steel mortar and a shot weighing 29 Ibs., and he adopted the plan of measuring the distance to which a given charge, 5 grms., would throw the shot. He obtained the following results:-- Range in Feet. Blasting gelatine (90 per cent. nitro-glycerine and nitro-cellulose) 392 Ammonite (60 per cent. Am(NO_{3}) and 10 per cent. nitro-naphthalene) 310 Gelignite (60 per cent. nitro-gelatine and gun-cotton) 306 Roburite (AmNO_{3} and chloro-nitro-benzol) 294 No. 1 dynamite (75 per cent. nitro-gelatine) 264 Stonite (68 per cent. nitro-gelatine and 32 per cent. wood-meal) 253 Gun-cotton 234 Tonite (gun-cotton and nitrates) 223 Carbonite (25 per cent. nitro-gelatine, 40 per cent. wood-meal, and 30 per cent. nitrates) 198 Securite (KNO_{3} and nitro-benzol) 183 Gunpowder 143 ~Calculation of the Volume of Gas Evolved in an Explosive Reaction.~--The volume of gas evolved in an explosive reaction may be calculated, but only when they are simple and stable products, such calculations being made at 0° and 760 mm. Let it be required, for example, to determine the volume of gas evolved by 1 gram-molecule of nitro-glycerine. The explosive reaction of nitro-glycerine may be represented by the equation. C_{3}H_{5}O_{3}(NO_{2})_{3} = 3CO_{2} + 2-1/2H_{2}O + 1-1/2N_{2} + 1/4O_{2} By weight 227 = 132 + 45 + 42 + 8 By volume 2 = 3 + 2-1/2 + 1-1/2 + 1/4 The weights of the several products of the above reactions are calculated by multiplying their specific gravities by the weight of 1 litre of hydrogen at 0° C. and 760 mm. (0.0896 grm). Thus, One litre of CO_{2} = 22 x .0896 = 1.9712 grm. " H_{2}O = 9 x " = 0.8064 " " N_{2} = 14 x " = 1.2544 " " O_{2} = 16 x " = 1.4336 " The volume of permanent gases at 0° and 760 mm. is constant, and assuming the gramme as the unit of mass, is found to be 22.32 litres. Thus:-- Volume of 44 of CO_{2}, at 0° and 760 mm. = 44/1.9712 = 22.32 litres. 18 " H_{2}O " " = 18/0.8044 = 22.32 " 28 " N_{2} " " = 28/1.2544 = 22.32 " 32 " O_{2} " " = 32/1.4366 = 22.32 " Therefore 132 grms. of CO_{2} at 0° C and 760 mm. = 22.32 x 3 = 66.96 litres. 45 " H_{2}O " " = 22.32 x 2-1/2 = 55.80 " 42 " N_{2} " " = 22.32 x 1-1/2 = 33.48 " 8 " O_{2} " " = 22.32 x 1/4 = 5.58 " ____________ 161.82 " Therefore 1 gram-molecule or 227 grms. of nitro-glycerine when exploded, produces 161.82 litres of gas at 0° C and 760 mm. To determine the volume of gas at the temperature of explosion, we simply apply the law of Charles.[A] Thus-- V : V' :: T : T' or V' = VT'/T in which V represents the original volume. V' " new volume. T " original temperature on the absolute scale. T' " new temperature of the same scale In the present case T' = 6001°. Therefore substituting, we have V' = 161.82x6001/273 = 3557 litres or at the temperature of explosion 1 gram-molecule of nitro-glycerine produces 3,557 litres of permanent gas. [Footnote A: According to the law of Charles, the volume of any gas varies directly as its temperature on the absolute scale, provided the pressure remains constant. Knowing the temperature on the centigrade scale, the corresponding temperature on the absolute scale is obtained by adding 273 to the degrees centigrade.] ~Pressure or Crusher Gauge.~--There are many forms of this instrument. As long ago as 1792 Count Rumford used a pressure gauge. The so-called crusher gauge was, however, first used by Captain Sir Andrew Noble in his researches on powder. Other forms are the Rodman[A] punch Uchatius Eprouvette, and the crusher gauge of the English Commission on Explosives. They are all based either upon the size of an indent made upon a copper disc by a steel punch fitted to a piston, acted upon by the gases of the explosive, or upon the crushing or flattening of copper or lead cylinders. [Footnote A: Invented by General Rodman, United States Engineers.] [Illustration: FIG. 55.--PRESSURE GAUGE.] Berthelot uses a cylinder of copper, as also did the English Commission, but in the simpler form of apparatus mostly used by manufacturers lead cylinders are used. This form of apparatus (Fig. 55) consists of a base of iron to which four uprights _a_ are fixed, set round the circumference of a 4-inch circle; the lead plug rests upon the steel base let into the solid iron block. A ring _c_ holds the uprights _d_ together at the top. The piston _b_, which rests upon the lead plug, is a cylinder of tempered steel 4 inches in diameter and 5 inches in length; it is turned away at the sides to lighten it as much as possible. It should move freely between the uprights _d_. In the top of this cylinder is a cavity to hold the charge of explosive. The weight of this piston is 12-1/4 lbs. The shot _e_ is of tempered steel, and 4 inches in diameter and 10 inches in length, and weighs 34-1/2 lbs. It is bored through its axis to receive a capped fuse. The instrument is used in the following manner:--A plug of lead 1 inch long and 1 inch in diameter, and of a cylindrical form, is placed upon the steel plate between the uprights _a_, the piston placed upon it, the carefully weighed explosive placed in the cavity, and the shot lowered gently upon the piston. A piece of fuse, with a detonator fixed at one end, is then pushed through the hole in the shot until it reaches the explosive contained in the cavity in the piston. The fuse is lighted. When the charge is exploded, the shot is thrown out, and the lead cylinder is more or less compressed. The lead plugs must be of a uniform density and homogeneous structure, and should be cut from lead rods that have been drawn, and not cast separately from small masses of metal. [Illustration: FIG. 56.--_b_, STEEL PUNCH; _c_, LEAD CYLINDER FOR USE WITH PRESSURE GAUGE.] The strength of the explosive is proportional to the work performed in reducing the height of the lead (or copper) plug, and to get an expression for the work done it is necessary to find the number of foot-pounds (or kilogrammetres) required to produce the different amounts of compression. This is done by submitting exactly similar cylinders of lead to a crushing under weights acting without initial velocity, and measuring the reduced heights of the cylinders; from these results a table is constructed establishing empirical relations between the reduced heights and the corresponding weights; the cylinders are measured both before and after insertion in the pressure gauge by means of an instrument known as the micrometer calipers (Fig. 57).[A] [Footnote A: An instrument called a "Foot-pounds Machine" has been invented by Lieut. Quinan, U.S. Army. It consists of three boards, connected so as to form a slide 16 feet high, in which a weight (the shot of the pressure gauge) can fall freely. One of the boards is graduated into feet and half feet. The horizontal board at the bottom, upon which the others are nailed, rests upon a heavy post set deep in the ground, upon which is placed the piston of the gauge, which in this case serves as an anvil on which to place the lead cylinders. The shot is raised by means of a pulley, fixed at the top of the structure, to any desired height, and let go by releasing the clutch that holds it. The difference between the original length and the reduced length gives the compression caused by the blow of the shot in falling, and gives the value in foot-pounds required to produce the different amounts of compression. (Vide _Jour. U.S. Naval Inst._, 1892.)] [Illustration: FIG. 57.--MICROMETER CALIPERS FOR MEASURING DIAMETER OF LEAD CYLINDERS.] ~The Use of Lead Cylinders.~--The method of using lead cylinders to test the strength of an explosive is a very simple affair, and is conducted as follows:--A solid cast lead cylinder, of any convenient size, is bored down the centre for some inches, generally until the bore-hole reaches to about the centre of the block. The volume of this hole is then accurately measured by pouring water into it from a graduated measure, and its capacity in cubic centimetres noted. The bore-hole is then emptied and dried, and a weighed quantity (say 10 grms.) of the explosive pressed well down to the bottom of the hole. A hole is then made in the explosive (if dynamite) with a piece of clean and rounded glass rod, large enough to take the detonator. A piece of fuse, fitted with a detonator, is then inserted into the explosive and lighted. After the explosion a large pear- shaped cavity will be found to have been formed, the volume of which is then measured in the same way as before. The results thus obtained are only relative, but are of considerable value for comparing dynamites among themselves (or gun-cottons). Experiments in lead cylinders gave the relative values for nitro-glycerine 1.4, blasting gelatine 1.4, and dynamite 1.0. (Fig. 58 shows sections of lead cylinders before and after use.) [Illustration: FIG. 58.--LEAD CYLINDERS BEFORE AND AFTER USE.] Standard regulations for the preparation of lead cylinders may be found in the _Chem. Zeit._, 1903, 27 [74], 898. They were drawn up by the Fifth International Congress of App. Chem., Berlin. The cylinder of lead should be 200 mm. in height and 200 mm. in diameter. In its axis is a bore-hole, 125 mm. deep and 25 mm. in diameter. The lead used must be pure and soft, and the cylinder used in a series of tests must be cast from the same melt. The temperature of the cylinders should be 15° to 20° throughout. Ten grms. of explosive should be used and wrapped in tin-foil. A detonator with a charge of 2 grms., to be fired electrically, is placed in the midst of the explosive. The cartridge is placed in the bore-hole, and gently pressed against the bottom, the firing wires being kept in central position. The bore-hole is then filled with dry quartz sand, which must pass through a sieve of 144 meshes to the sq. cm., the wires being .35 mm. diameter. The sand is filled in evenly, any excess being levelled off. The charge thus prepared is then fired electrically. The lead cylinder is then inverted, and any residues removed with a brush. The number of c.c. of water required to fill the cavity, in excess of the original volume of the bore-hole, is a measure of the strength of the explosive. The results are only comparable if made with the same class of explosive. A result is to be the mean of at least three experiments. The accuracy of the method depends on (_a_) the uniform temperature of the lead cylinder (15° to 20° C. 7); (_b_) on the uniformity of the quartz sand; (_c_) on the uniformity of the measurements. [Illustration: FIG. 59.--NOBLE'S PRESSURE GAUGE.] ~Noble's Pressure Gauge.~--The original explosive vessels used by Captain Sir A. Noble in his first experiments were practically exactly similar to those that he now employs, which consists of a steel barrel A (Fig. 59), open at both ends, which are closed by carefully fitted screw plugs, furnished with steel gas checks to prevent any escape past the screw. The action of the gas checks is exactly the same as the leathers used in hydraulic presses. The pressure of the gas acting on both sides of the annular space presses these sides firmly against the cylinder and against the plug, and so effectually prevents any escape. In the firing plug F is a conical hole closed by a cone fitting with great exactness, which, when the vessel is prepared for firing, is covered with fine tissue paper to act as an insulator. The two firing wires GG, one in the insulated cone, the other in the firing plug, are connected by a very fine platinum wire passing through a glass tube filled with meal powder. The wire becomes red-hot when connection is made with a Leclanché battery, and the charge which has previously been inserted into the vessel is fired. The crusher plug is fitted with a crusher gauge H for determining the pressure of the gases at the moment of explosion, and in addition there is frequently a second crusher gauge apparatus screwed into the cylinder. When it is desired to allow the gases to escape for examination, the screw J is slightly withdrawn. The gases then pass into the passage I, and can be led to suitable apparatus in which their volume can be measured, or in which they can be sealed for subsequent chemical analysis. The greatest care must be exercised in carrying out experiments with this apparatus; it is particularly necessary to be sure that all the joints are perfectly tight before exploding the charge. Should this not be the case, the gases upon their generation will cut their way out, or completely blow out the part improperly secured, in either case destroying the apparatus. The effect produced upon the apparatus when the gas has escaped by cutting a passage for itself is very curious. The surface of the metal where the escape occurred presents the appearance of having been washed away in a state of fusion by the rush of the highly heated products. ~The Pressure Gauge.~--The pressure is found by the use of a little instrument known as the pressure gauge which consists of a small chamber formed of steel, inside of which is a copper cylinder, and the entrance being closed by a screw gland, in which a piston, having a definite sectional area, works. There is a gas check E (Fig. 60) placed in the gland, and over the piston, which prevents the admission of gas to the chamber. When it is desired to find the pressure in the chamber of a gun, one or more of these crushers are made up with or inserted at the extreme rear end of the cartridge, in order to avoid their being blown out of the gun when fired. This, however, often takes place, in which case the gauges are usually found a few yards in front of the muzzle. The copper cylinders which register the pressure are made 0.5 inch long from specially selected copper, the diameters being regulated to give a sectional area of either 1/12 or 1/24 square inch. [Illustration: FIG. 60.--CRUSHER GAUGE. _E_, GAS CHECK.] Hollow copper cylinders are manufactured with reduced sectional areas for measuring very small pressures. It has been found that these copper cylinders are compressed to definite lengths for certain pressures with remarkable uniformity. Thus a copper cylinder having a sectional area of 1/12 square inch, and originally 1/2 inch long, is crushed to a length of 0.42 inch by a pressure of 10 tons per square inch. By subsequently applying a pressure of 12 tons per square inch the cylinder is reduced to a length of 0.393 inch. Before using the cylinders, whether for experimenting with closed vessels or with guns, it is advisable to first crush them by a pressure a little under that expected in the experiment. Captain Sir A. Noble used in his experiments a modification of Rodman's gauge. (Ordnance Dept., U.S.A., 1861.) ~By Calculation.~--To calculate the pressure developed by the explosion of dynamite in a bore-hole 3 centimetres in diameter, charged with 1 kilogramme of 75 per cent. dynamite, Messrs Vieille and Sarrau employ the following formula:-- P = V_{o}(1 + Q/273._c_)/(V - _v_). Where V_{o} = the volume (reduced to 0° and 760 mm.) of the gases produced by a unit of weight of the explosive; Q the number of calories disengaged by a unit of weight of the explosive; _c_ equals the specific heat at constant volume of the gases; V the volume in cubic centimetres of a unit of weight of the explosive; _v_ the volume occupied by the inert materials of the explosive. The volume of gas produced by the explosion of 1 kilogramme of nitro-glycerine (at 0° and 760 mm.) is 467 litres. V_{o} will therefore equal 0.75 x 467 = 350.25. The specific heat _c_ is, according to Sarrau, .220 (_c_); and according to Bunsen, 1 kilogramme of dynamite No. 1 disengages 1,290 (Q) calories. The density of dynamite is equal to 1.5, therefore V = 1/1.5 = .666. If we take the volume of the kieselguhr as .1, we find from above formula that P = 350(1 + 1290/(273 x .222))/(.600 - .1) = 13,900 atmospheres, which is equal to 14,317 kilogrammes per square centimetre. The pressure developed by 1 kilogramme of pure nitro-glycerine equals 18,533 atmospheres, equals 19,151 kilogrammes. Applying this formula to gun- cotton, and taking after Berthelot, Q = 1075, and after Vieille and Sarrau, V_{o} = 671 litres, and _c_ as .2314, and the density of the nitro-cellulose as 1.5, we have (V = O) P = 671(1 + 1075/(273 x .2314))/.666 = 18,135 atmospheres. To convert this into pressure of kilogrammes per square centimetre, it is necessary to multiply it by the weight of a column of mercury 0.760 m. high, and 1 square centimetre in section, which is equal to increasing it by 1/30. It thus becomes P^{k} = (1 + 1/30). P^{k} = 18,135 x 1.033 = 18,733 kilogrammes. The following tables, taken from Messrs William Macnab's and E. Ristori's paper (_Proc. Roy. Soc._, 56, 8-19), "Researches on Modern Explosives," are very interesting. They record the results of a large number of experiments made to determine the amount of heat evolved, and the quantity and composition of the gases produced when certain explosives and various smokeless powders were fired in a closed vessel from which the air had been previously exhausted. The explosions were carried out in a "calorimetric bomb" of Berthelot's pattern.[A] [Footnote A: For description of "bomb," see "Explosives and their Power," Berthelot, trans. by Hake and Macnab, p. 150. (Murray.)] Table Showing Quantity of Heat and Volume and Analysis of Gas Developed per Gramme with Different Sporting and Military Smokeless Powders Now In Use ______________________________________________________________________ | | | | | Name of Explosive. | Calories | Permanent | Aqueous | Total Volume | | per grm. | Gases. | Vapour. | of Gas at 0° | | | | | and 760 mm. | ______________________|__________|___________|_________|______________| | | cc/grm | cc/grm | cc/grm | E.C. powder, English | 800 | 420 | 154 | 574 | S.S. powder | 799 | 584 | 150 | 734 | Troisdorf, German | 943 | 700 | 195 | 895 | Rifleite, English | 864 | 766 | 159 | 925 | B.N., French | 833 | 738 | 168 | 906 | Cordite, English | 1253 | 647 | 235 | 882 | Ballistite, German | 1291 | 591 | 231 | 822 | Ballistite, Italian | 1317 | 58l | 245 | 826 | and Spanish | | | | | ______________________|__________|___________|_________|______________| The figures in column headed "Co-efficient of Potential Energy" serve as a measure of comparison of the power of the explosives, and are the products of the number of calories by the volume of gas, the last three figures being suppressed in order to simplify the results. The amounts of water found were calculated for comparison as volumes of H_{2}O gas at 0° and 760 mm. E.C. powder consists principally of nitro-cellulose mixed with barium nitrate and a small proportion of camphor. S.S. of nitro-lignine mixed with barium nitrate and nitro-benzene. Troisdorf powder is gelatinised nitro-cellulose; rifleite gelatinised nitro-cellulose and nitro-benzene. Cordite contains 58 per cent. nitro-glycerine, 37 per cent. gun-cotton, and 5 per cent. vaseline. Ballistite (Italian) consists of equal parts nitro-cellulose and nitro- glycerine, and 1/2 per cent. of aniline. The German contains a higher percentage of nitro-cellulose. TABLE SHOWING THE HEAT DEVELOPED BY EXPLOSIVES CONTAINING NITRO-GLYCERINE AND NITRO-CELLULOSE IN DIFFERENT PROPORTIONS. ______________________________________________________________________ Composition of Explosives. | Calories per cent. _____________________________________________|________________________ Nitro-cellulose | | (N = 13.3 per cent.). | Nitro-glycerine. | | | 100 per cent. dry pulp | 0 | 1061 100 " gelatinised | 0 | 922 90 " | 10 per cent. | 1044 80 " | 20 " | 1159 70 " | 30 " | 1267 60 " | 40 " | 1347 50 " | 50 " | 1410 40 " | 60 " | 1467 0 " | 100 " | 1652 __________________________|__________________|________________________ | | Nitro-cellulose | | (N=12.24 per cent.) | Nitro-glycerine. | | | 80 per cent. | 20 per cent. | 1062 60 " | 40 " | 1288 50 " | 50 " | 1349 40 " | 60 " | 1405 | | __________________________|__________________|________________________| Nitro-cellulose | | (N = 13.3 per cent.). | Nitro-glycerine. | Vaseline. | | 55 per cent. | 40 per cent. | 5 per cent. 1134 35 " | 60 " | 5 " 1280 __________________________|__________________|________________________ TABLE OF RESULTS OBTAINED BY LIEUT. W. WALKE., OF THE ARTILLERY, U.S.A, WITH QUINAN'S PRESSURE GAUGE. Nitro-glycerine being taken as 100. (From _U.S. Naval Inst. Jour._) __________________________________________________________________________ | | | | Compression | Order of | Name of Explosive. | of Lead | Strength. | | | | | Inch. | | Explosive gelatine | 0.585 | 106.17 | Hellhoffite | 0.585 | 106.17 | Nitro-glycerine | 0.551 | 100.00 | Standard, N.G. Nobel's smokeless powder | 0.509 | 92.38 | Nitro-glycerine | 0.509 | 92.37 | Gun-cotton | 0.458 | 83.12 | U.S. naval torpedo | | | gun-cotton Gun-cotton | 0.458 | 83.12 | Stowmarket. Nitro-glycerine | 0.451 | 81.85 | Vouges, N.G. Gun-cotton | 0.448 | 81.31 | Dynamite No. 1 | 0.448 | 81.31 | Dynamite de Traul | 0.437 | 79.31 | Emmensite | 0.429 | 77.86 | Amide powder | 0.385 | 69.87 | Oxonite | 0.383 | 69.51 | Tonite | 0.376 | 68.24 | G.C. 52.5%, and | | | Ba(NO_{3})_{2}, 47.5% Bellite | 0.362 | 65.70 | Rack-a-rock | 0.340 | 61.71 | Atlas powder | 0.333 | 60.43 | Ammonia dynamite | 0.332 | 60.25 | Volney's powder No. 1 | 0.322 | 58.44 | Nitrated naphthalene. " No. 2 | 0.294 | 53.18 | " " Melinite | 0.280 | 50.82 | Picric acid 70%, and | | | sol. nitro-cotton 30%. Silver fulminate | 0.277 | 50.27 | Mercury | 0.275 | 49.91 | Mortar powder | 0.155 | 28.13 | _________________________|_____________|___________|______________________ ~Composition of some of the Explosives in Common Use.~ ~Ordinary Dynamite.~ Nitro-Glycerine 75 per cent. Kieselguhr 25 " ~Amvis.~ Nitrate of Ammonia 90 per cent. Chloro-di-nitro Benzene 5 " Wood Pulp 5 " ~Ammonia Nitrate Powder.~ Nitrate of Ammonia 80 per cent. Chlorate of Potash 5 " Nitro-Glucose 10 " Coal Tar 5 " ~Celtite.~ Nitro-Glycerine 56-59 parts. Nitro-Cotton 2-3.5 " KNO_{3} 17-21 " Wood Meal 8-9 " Ammonium Oxalate 11-13 " Moisture 0.5-1.5 " ~Atlas Powders.~ Sodium Nitrate 2.0 per cent. Nitro-Glycerine 75.0 " Wood Pulp 21.0 " Magnesium Carbonate 2.0 " ~Dauline.~ Nitro-Glycerine 50 per cent. Sawdust 30 " Nitrate of Potash 20 " ~Vulcan Powder.~ Nitro-Glycerine 30 per cent. Nitrate of Soda 52.5 " Sulphur 7.0 " Charcoal 10.5 " ~Vigorite.~ Nitro-Glycerine 30 per cent. Nitrate of Soda 60 " Charcoal 5 " Sawdust 5 " ~Rendrock.~ Nitrate of Potash 40 per cent. Nitro-Glycerine 40 " Wood Pulp 13 " Paraffin or Pitch 7 " ~Ammonia Nitrate Powder.~ Ammonia Nitrate 80 per cent. Potassium Chlorate 5 " Nitro-Glucose 10 " Coal Tar 5 " ~Hercules Powders.~ Nitro-Glycerine 75 to 40 per cent. Sugar 1 " 15.66 " Chlorate of Potash 1.05 " 3.34 " Nitrate of Potash 2.10 " 31.00 " Carbonate of Magnesia 20.85 " 10.00 " ~Carbo-Dynamite.~ Nitro-Glycerine 90 per cent. Charcoal 10 " ~Geloxite (Permitted List).~ Nitro-Glycerine 64-54 parts. Nitro-Cotton 5-4 " Nitrate of Potash 22-13 " Ammonium Oxalate 15-12 " Red Ochre 1-0 " Wood Meal 7-4 " The Wood Meal to contain not more than 15% and not less than 5% moisture. ~Giant Powder.~ Nitro-Glycerine 40 per cent. Sodium Nitrate 40 " Rosin 6 " Sulphur 6 " Guhr 8 " ~Dynamite de Trauzel.~ Nitro-Glycerine 75 parts. Gun-Cotton 25 " Charcoal 2 " ~Rhenish Dynamite.~ Solution of N.G. in Naphthalene 75 per cent. Chalk, or Barium Sulphate 2 " Kieselguhr 23 " ~Ammonia Dynamite.~ Ammonia Nitrate 75 parts. Paraffin 4 " Charcoal 3 " Nitro-Glycerine 18 " ~Blasting Gelatine.~ Nitro-Glycerine 93 per cent. Nitro-Cotton 3 to 7 " ~Gelatine Dynamite.~ Nitro-Glycerine 71 per cent. Nitro-Cotton 6 " Wood Pulp 5 " Potassium Nitrate 18 " ~Gelignite.~ Nitro-Glycerine 60 to 61 per cent. Nitro-Cotton 4 " 5 " Wood Pulp 9 " 7 " Potassium Nitrate 27 " ~Forcite.~ Nitro-Glycerine 49 per cent. Nitro-Cotton 1.0 " Sulphur 1.5 " Tar 10.0 " Sodium Nitrate 38.0 " Wood Pulp 5 " (The N.-G., &c., varies.) ~Tonite No. 1.~ Gun-Cotton 52-50 per cent. Barium Nitrate 47-40 " ~Tonite No. 2.~ Contains Charcoal also. ~Tonite No. 3.~ Gun-Cotton 18 to 20 per cent. Ba(NO_3)_2 70 " 67 " Di-nitro-Benzol 11 " 13 " Moisture 0.5 " 1 " ~Carbonite.~ Nitro-Glycerine 17.76 per cent. Nitro-Benzene 1.70 " Soda 0.42 " KNO_3 34.22 " Ba(NO_3)_2 9.71 " Cellulose 1.55 " Cane Sugar 34.27 " Moisture 0.36 " ________ 99.99 ~Roburite.~ Ammonium Nitrate 86 per cent. Chloro-di-nitro-Benzol 14 " ~Faversham Powder.~ Ammonium Nitrate 85 per cent. Di-nitro-Benzol 10 " Trench's Flame-extinguishing Compound 5 " ~Favierite No. 1.~ Ammonium Nitrate 88 per cent. Di-nitro-Naphthalene 12 " ~Favierite No. 2.~ No. 1 Powder 90 per cent. Ammon. Chloride 10 " ~Bellite.~ Ammonium Nitrate 5 parts. Meta-di-nitro-Benzol 1 " ~Petrofacteur.~ Nitro-Benzene 10 per cent. Chlorate of Potash 67 " Nitrate of Potash 20 " Sulphide of Antimony 3 " ~Securite.~ Mixtures of Meta-di-nitro-Benzol 26 per cent. and Nitrate of Ammonia 74 " ~Rack-a-Rock.~ Potassium Chlorate 79 parts. Mono-nitro-Benzene 21 " ~Oxonite.~ Nitric Acid (sp. gr. 1.5) 54 parts. Picric Acid 46 " ~Emmensite.~ Emmens Acid 5 parts. Ammonium Nitrate 5 " Picric Acid 6 " ~Brugère Powder.~ Ammonium Picrate 54 per cent. Nitrate of Potash 46 " ~Designolle's Torpedo Powders.~ Potassium Picrate 55 to 50 per cent. Nitrate of Potash 45 " 50 " ~Stowite.~ Nitro-Glycerine 58 to 61 parts. Nitro-Cotton 4.5 " 5 " Potassium Nitrate 18 " 20 " Wood Meal 6 " 7 " Oxalate of Ammonia 11 " 15 " The Wood Meal shall contain not more than 15% and not less than 5% by weight of moisture. The explosive shall be used only when contained in a non-water-proofed wrapper of parchment--No. 6 detonator. ~Faversham Powder.~ Nitrate of Ammonium 93 to 87 Tri-nitro-Toluol 11 " 9 Moisture 1 " -- ~Kynite.~ Nitro-Glycerine 24-26 parts. Wood-Pulp 2.5-3.5 " Starch 32.5-3.5 " Barium Nitrate 31.5-34.5 " CaCO_{3} 0-0.5 " Moisture 3.0-6.0 " Must be put up only in water-proof parchment paper, and No. 6 electric detonator used. ~Rexite.~ Nitro-Glycerine 6.5-8.5 parts. Ammonium Nitrate 64-68 " Sodium Nitrate 13-16 " Tri-nitro-Tolulene 6.5-8.5 " Wood Meal 3-5 " Moisture .5-1.4 " Must be contained in water-proof case (stout paper), water-proofed with Resin and Cerasin--No. 6 detonator. ~Withnell Powder.~ Ammonium Nitrate 88-92 parts. Tri-nitro-Toluene 4-6 " Flour (dried at 100° C.) 4-6 " Moisture 0-15 " Only to be used when contained in a linen paper cartridge, water-proofed with Carnuba Wax, Parrafin--No. 7 detonator used. ~Phenix Powder.~ Nitro-Glycerine 28-31 parts. Nitro-Cotton 0-1 " Potassium Nitrate 30-34 " Wood Meal 33-37 " Moisture 2-6 " ~SMOKELESS POWDERS.~ ~Cordite.~ Nitro-Glycerine 58 per cent. +or- .75 Nitro-Cotton 37 " +or- .65 Vaseline 5 " +or- .25 ~Cordite, M.D.~ Nitro-Glycerine 30 per cent. +or- 1 Nitro-Cotton 65 " +or- 1 Vaseline 5 " +or- .25 Analysis of-- By W. Mancab and A.E. Leighton. ~E.C. Powder.~ Nitro-Cotton 79.0 per cent. Potassium Nitrate 4.5 " Barium Nitrate 7.5 " Camphor 4.1 " Wood Meal 3.8 " Volatile Matter 1.1 " ~Walarode Powder.~ Nitro-Cotton 98.6 per cent. Volatile Matter 1.4 " ~Kynoch's Smokeless.~ Nitro-Cotton 52.1 per cent. Di-nitro-Toluene 19.5 " Potassium Nitrate 1.4 " Barium Nitrate 22.2 " Wood Meal 2.7 " Ash 0.9 " Volatile Matter 1.2 " ~Schultze.~ Nitro-Lingin 62.1 per cent. Potassium Nitrate 1.8 " Barium Nitrate 26.1 " Vaseline 4.9 " Starch 3.5 " Volatile Matter 1.0 " ~Imperial Schultze.~ Nitro-Lignin 80.1 per cent. Barium Nitrate 10.2 " Vaseline 7.9 " Volatile Matter 1.8 " ~Cannonite.~ Nitro-Cotton 86.4 per cent. Barium Nitrate 5.7 " Vaseline 2.9 " Lamp Black 1.3 " Potassium Ferro-cyanide 2.4 " Volatile Matter 1.3 " ~Amberite.~ Nitro-Cotton 71.0 per cent. Potassium Nitrate 1.3 " Barium Nitrate 18.6 " Wood Meal 1.4 " Vaseline 5.8 " ~Sporting Ballistite.~ Nitro-Glycerine 37.6 per cent Nitro-Cotton 62.3 " Volatile Matter 0.1 " The following is a complete List of the Permitted Explosives as Defined in the Schedules to the Explosives in Coal Mines Orders of the 20th December 1902, of the 24th December 1903, of the 5th September 1903, and 10th December 1903:-- Albionite. Ammonal. Ammonite. Amvis. Aphosite. Arkite. Bellite No. 1. Bellite No. 2. Bobbinite. Britonite. Cambrite. Carbonite. Clydite. Coronite. Dahmenite A. Dragonite. Electronite. Faversham Powder. Fracturite. Geloxite. Haylite No. 1. Kynite. Negro Powder. Nobel's Ardeer Powder. Nobel Carbonite. Normanite. Pit-ite. Roburite No. 3. Saxonite. Stow-ite. Thunderite. Victorite. Virite. West Falite No. 1. West Falite No. 2. INDEX. Abel's, Sir Frederick, method of manufacturing gun-cotton, 57. Abel's heat test, 249. Acid mixture for nitrating nitro-glycerine, 23. Air pressure in nitrator, 28. Alkalinity in nitro-cellulose, 217. Amberite, 189. Ammonite, 149. Analyses of collodion-cotton, 81. gelatine dynamites, 123. Analysis of explosives, 197. acetone, 209. blasting gelatine, 199. cap composition, 241. cordite, 206. celluloid, 230. dynamite, 197. forcite, 202. fulminate, 240. glycerine, 233. gun-cotton, 212. nitric acid, 24. picric acid, 230. tonite, 205. waste acids, 239. Armstrong on the constitution of the fulminates, 159. Atlas powder, 119. Auld on acetone, 211. Axite, 176. Ballistite, 179. Beater or Hollander for pulping gun-cotton, 64. Bedson, Prof., on roburite explosion gases, 140. Bellite, 142. Benzene, explosives derived from, 132. Benzene, mono-nitro- and di-nitro-benzene, 134. Bergmann and Junk on nitro-cellulose tests, 268. Bernthsen summary of nitro-benzenes, 133. Blasting gelatine, 119. Blasting charge, preparation of, 166. B.N. powder, 190. Boiling-point of N.G., 19. Boutnny's nitro-glycerine process, 15. Brown on wet gun-cotton, 56. Brugère's powder, 195. Bucknill's resistance coil, 13. Calculation of volume of gas evolved in an explosive reaction, 276. Cannonite, 189. Cellulose, 2, 47. Celluloid manufacture, 91. analysis, 230. cartridges, 91. uses of, 90. Field's papers on, 93. fibre for, 94. nitration of fibre, &c., 95. formula of, 57. Champion and Pellet's method of determining nitrogen, 223. Chenel's modification of Kjeldahl's method, 227. Collodion-cotton, 79. Comparative tests of black and nitro-powders, 193. Compressing gun-cotton, 77. Composition of waste acids from nitro-glycerine, 43. Composition of some common explosives, 290. Conduits for nitro-glycerine, 7. Cooppal powder, 5, 189. Cordite manufacture, 169. analysis, 206. Cresilite, 158. Cross and Bevan on nitro-jute, 107. Crusher gauge, 284. Cundill, Colonel, classification of dynamites, 112. Danger area, 5. Dangers in the manufacture of gun-cotton, 85. Decomposition of cellulose, 54. Definition of explosives in Order of Council (Explosives Act), 1. Determination of N_{2}O_{4} in nitric acid, 24. Determination of strength of H_{2}SO_{4}, 25. Determination of relative strength of explosives, 272. Detonators, 163. Di-nitro-toluene, 138. Dipping cotton in manufacture of gun-cotton, 60. Divers and Kawakita on the fulminates, 159. Dixon, Prof. H.B., on roburite explosions, 139. Drying house for gun-cotton, 122. Dynamite, efficiency of, 118. frozen dynamite, 116. gelatine dynamite, 119. properties of kieselguhr dynamite, 116. Reid & Borland's carbo-dynamite, 119. Rhenish dynamite, 119. various kinds of, 119. E.C. powder, 186. Electronite, 151. Emmensite, 195. Equation of formation of nitro-glycerine, 16. Equation of formation of nitro-cellulose, 50. Exploders, electric, 167. Explosion gases of dynamite, 19. nitro-glycerine, 18. gun-cotton, 55. roburite, 139. Exudation test gelatines, 257. Faversham powder, 147. Favier's explosive, 149. Field on celluloid, 93, 99. Firing-point of explosives, 247. Filite, 180. Filtering nitre-glycerine, 37. Flameless explosives, 89, 138, 144. Formation of white matter in the nitration of N.G., 39. Forcite, 119. France, 82. Free fatty acid in glycerine, 39, 235. Freeing nitric acid from N_{2}O_{4}, 25. Freezing-point of N.G., 21. French Commission on Ammonium Nitrate, 142. Fulminates constitution, 159. Fulminate of mercury, 159, 240. Fulminate of silver, 161. Fuses, various kinds of, 166. Gases formed by the decomposition of nitro-glycerine, 18. Gelatine explosives, analysis of, 199. Glycerine, analysis of, 233. formula of, 16. nitration of, 23. Greiner's powder, 190. Gun-cotton, analysis of, 212. boiling, 64. complete series of, 52, 54. compressing, moulding, and packing, 67, 77, 78. dipping and steeping the cotton, 60. drying the cotton, 58. granulation of, 79. manufacture of, 57. Abel's method, 57. Stowmarket, 57. Waltham Abbey, 71. products of decomposition of, 55. properties of, 54. pulping, 65. washing, 63. as a mining explosive, 56. Guttmann's nitric acid plant, 45. Guttmann's heat test, 256. Handy's method for determining moisture in dynamite, 197. Hannah, Dr N., on roburite explosion gases, 139. Heat developed by explosives containing nitro-glycerine, &c., 288. Heat test, Abel, 249. Hellhoffite, 152. Henrite powder, 191. Hollander, 65. Horsley's apparatus, 248. Hydro-extractors for wringing out gun-cotton, 62. Impurities in commercial glycerine, 39, 233. Impurities in fulminate, 240. nitro-glycerine, 38. picric acid, 231. Ketones as solvents for pyroxyline, 101. Kieselguhr dynamite, 112. Kinetite, 145. Kjeldahl method of determining nitrogen, 227. Le Bouchet, manufacture of gun-cotton at, 78. Lead cylinders for testing strength of explosives, 281. Lenk's improvements in gun-cotton manufacture, 49. Lewes on the pressure of cordite, 175. Leibert's treatment of nitro-glycerine, 30. Lightning conductors for danger buildings, 10. Liquefaction test for gelatine, 257. Lodge on lightning conductors, 8. Lowering of freezing-point of N.G., 21. Lungé's nitrometer, 219. Lydite, 156. Manufacture of gun-cotton, 57. Manufacture of nitro-glycerine, 17. cordite, 169. roburite, 140. fulminates, 162. tonite, 84. di-nitro-benzene, 138. nitro-starch, 103. celluloid, 91. Majendie (Col. Sir V.D.), report on a picric acid explosion, 155. Maximite, 191. Maxim's detonator mixture, 165. M'Robert's mixing machine, 126. Mechanical equivalent of explosives, 273. Melinite, 156. Mono-nitro-glycerine, di-nitro-nitro-glycerine, 41. Moulding gun-cotton, 77. Mounds for protection of danger buildings, 6. Mortar for ballistic tests, 275. Mowbray on use of compressed air, 15. Mühlhäusen on nitro-starch, 4, 5, 103. Nathan's nitrator, 32. Nitric peroxide in N.G., 24. Nitration products of cellulose, 52, 54. Nitro-glycerine, analysis of, 198. properties, 17. nitration, 23. separation, 35. washing, 37. uses of, 41. manufacture of, 17. Nitro-benzene, properties and manufacture of, 132, 137. Nitro-cellulose, 2, 47, 60, 212. Nitro-jute, 5, 107. Nitro-mannite, 4, 109. Nitro-naphthalene, 148. Nitro-starch, 4, 103. Nitro-toluene, 132. Nitrated gun-cotton, 83. Nitrogen, determination of, Lungé method, 219. Champion and Pellet's, 223. Schultze-Tieman, 224. Kjeldahl-Chenel's, 227. percentages of in various explosives, 228. Nitrometers, Lungé, Horn's, &c., 220, 222. Nobel's ballistic test, 274. Noble's pressure gauge, 282. experiments on cordite, 172. Normal powder, 191. Oleic acid in glycerine, 236. Orsman on roburite, 142. Oxonite, 152. Oxy-cellulose, 102. Packing gun-cotton, 78. dynamite, 116. Page's regulator, 260. Panclastite, 152. Percentage composition of nitro-glycerine, 18. Perkin on magnetic rotation of nitro-glycerine, 19. Phenol, tri-nitro-phenol, 152. Picric acid, 152, 231. powders, 157, 189. Picrates, 154, 231. Polarised light and nitro-cellulose, 218. Position of the NO_{2} group in nitro-explosives, 2, 3, 16. Prentice's nitric acid plant, 43. Pressure gauge, 282. Primers of gun-cotton, 166. Properties of dynamite, 116. gelatine compounds, 130. Pulping gun-cotton, 65. Pyroxyline for celluloid, 96. solvents for, 101. Quinan's foot-pound machine, 280. Raoult's law and N.G., 21. Reworked gun-cotton, 78. Rhenish dynamite, 119. Roburite, properties and manufacture of, 138. Bedson's report on, 140. Orsman on gases produced by explosion of, 142. Romit, 148. Sarrau and Vieille, gases obtained from ignition of dynamite, 19. Sayers, 50. Scheme for analysis of explosives, 213. Schultze's powder, 183. Schultze-Tieman method of determining nitrogen, 224. Securite, 144. Separation of nitro-glycerine from mixed acids, 35. Shimose, 156. Silver test for glycerine, 233. Smokeless powders, 168. Smokeless diamond, 190. Snyder's powder, 193. Sobrero discovered nitro-glycerine, 14. Sodium nitrate, analysis of, 239. Soluble and insoluble nitro-cellulose, 51. Solubility of nitro-glycerine, 20. Solvents for soluble gun-cotton, 52, 101. Solubility test for gun-cotton, 214. Specific gravity of explosives, 270. Sprengel's explosives, 151. Stowmarket, manufacture of gun-cotton at, 57. Sulphuric acid, determination of strength of, 24. Sy on test for nitro-cellulose, 269. Temperature of nitration of nitro-glycerine, 29. Thomson's patents, 73. Toluene, 146. Tonite, 84, 146. analysis of, 205. fumes from, 85. Treatment of waste acids, 43. Trench's fire-extinguishing compound, 88. Trebouillet and De Besancele on celluloid manufacture, 92. Tri-nitro-cresol, 158. Tri-nitro-toluene, 146. Tri-nitro-phenol, 152. Tri-nitro-glycerine, 2, 14. Troisdorf powder, 191, 192. Turpin's melinite, 156. U.S. naval powder, 180. Uses of celluloid, 91, 93, 102. Uses of collodion-cotton, 90. Vaseline, 208. Vielle poudre, 190. Volney's powder, 148. Von Foster's powder, 191. Walsrode powder, 188. W.A. powder, 182. Waltham Abbey, manufacture of gun-cotton at, 71. manufacture of cordite at, 169. Walke's pressure gauge results, 289. War Office experiments with cordite, 173. Washing gun-cotton, 63. nitro-glycerine, 37. Waste acids from nitro-glycerine, 41, 226. Weltern powder, 191. Werner & Pfleiderer's mixing machine, 124. Whirling out the acids from gun-cotton, 62. Will's test for nitre-cellulose, 261. Wood pulp, 126. Xylonite Company's process, 96. Zenger's lightning conductors, 11. _Printed at_ THE DARLEN PRESS, _Edinburgh_. 
17625	----	Transcriber's Notes: 1. Subscripts have been marked with an underscore character in front with text surrounded in curly braces, for example: H_{2}O (formula of water). 2. Inconsistent hyphenation of words preserved. 3. Several misprints fixed. A full list of corrections can be found at the end of the text. [Illustration: LIGHT AND LIBERTY] The Century Books of Useful Science ARTIFICIAL LIGHT ITS INFLUENCE UPON CIVILIZATION BY M. LUCKIESH DIRECTOR OF APPLIED SCIENCE. NELA RESEARCH LABORATORY, NATIONAL LAMP WORKS OF GENERAL ELECTRIC COMPANY Author of "Color and Its Applications," "Light and Shade and Their Applications," "The Lighting Art," "The Language of Color," etc. _ILLUSTRATED WITH PHOTOGRAPHS_ NEW YORK THE CENTURY CO. 1920 Copyright, 1920, by THE CENTURY CO. DEDICATED TO THOSE WHO HAVE ENCOURAGED ORGANIZED SCIENTIFIC RESEARCH FOR THE ADVANCEMENT OF CIVILIZATION PREFACE In the following pages I have endeavored to discuss artificial light for the general reader, in a manner as devoid as possible of intricate details. The early chapters deal particularly with primitive artificial light and their contents are generally historical. The science of light-production may be considered to have been born in the latter part of the eighteenth century and beginning with that period a few chapters treat of the development of artificial light up to the present time. Until the middle of the nineteenth century _mere_ light was available, but as the century progressed, the light-sources through the application of science became more powerful and efficient. Gradually _mere_ light grew to _more_ light and in the dawn of the twentieth century _adequate_ light became available. In a single century, after the development of artificial light began in earnest, the efficiency of light-production increased fifty-fold and the cost diminished correspondingly. The next group of chapters deals with various economic influences of artificial light and with some of the byways in which artificial light is serving mankind. On passing through the spectacular aspects of lighting we finally emerge into the esthetics of light and lighting. The aim has been to show that artificial light has become intricately interwoven with human activities and that it has been a powerful influence upon the progress of civilization. The subject is too extensive to be treated in detail in a single volume, but an effort has been made to present a discussion fairly complete in scope. It is hoped that the reader will gain a greater appreciation of artificial light as an economic factor, as an artistic medium, and as a mighty influence upon the safety, efficiency, health, happiness, and general progress of mankind. M. LUCKIESH. ACKNOWLEDGMENTS It is a pleasant duty to acknowledge the coöperation of various companies in obtaining the photographs which illustrate this book. With the exception of Plates 2 and 7, which are reproduced from the excellent works of Benesch and Allegemane respectively, the illustrations of early lighting devices are taken from an historical collection in the possession of the National Lamp Works of the General Electric Co. To this company the author is indebted for Plates 1, 3, 4, 5, 6, 9, 11, 15, 18b, 20, 21, 29; to Dr. McFarlan Moore for Plate 10; to Macbeth Evans Glass Co. for Plate 12; to the Corps of Engineers, U. S. Army, for Plate 13; to Lynn Works of G. E. Co. for Plates 14, 16; to Edison Lamp Works of G. E. Co. for Plates 17, 24; to Cooper Hewitt Co. for Plate 18a; to R. U. V. Co. for Plate 19; to New York Edison Co. for Plates 22, 26, 30; to W. D'A. Ryan and the Schenectady Works of G. E. Co. for Plates 23, 25, 31; to National X-Ray Reflector Co. for Plate 28. Besides the companies and the individuals particularly involved in the foregoing, the author is glad to acknowledge his appreciation of the assistance of others during the preparation of this volume. CONTENTS CHAPTER PAGE I LIGHT AND PROGRESS 3 II THE ART OF MAKING FIRE 15 III PRIMITIVE LIGHT-SOURCES 24 IV THE CEREMONIAL USE OF LIGHT 38 V OIL-LAMPS OF THE NINETEENTH CENTURY 51 VI EARLY GAS-LIGHTING 63 VII THE SCIENCE OF LIGHT-PRODUCTION 80 VIII MODERN GAS-LIGHTING 97 IX THE ELECTRIC ARCS 111 X THE ELECTRIC INCANDESCENT FILAMENT LAMPS 127 XI THE LIGHT OF THE FUTURE 143 XII LIGHTING THE STREETS 152 XIII LIGHTHOUSES 163 XIV ARTIFICIAL LIGHT IN WARFARE 178 XV SIGNALING 194 XVI THE COST OF LIGHT 208 XVII LIGHT AND SAFETY 225 XVIII THE COST OF LIVING 238 XIX ARTIFICIAL LIGHT AND CHEMISTRY 256 XX LIGHT AND HEALTH 269 XXI MODIFYING ARTIFICIAL LIGHT 284 XXII SPECTACULAR LIGHTING 298 XXIII THE EXPRESSIVENESS OF LIGHT 310 XXIV LIGHTING THE HOME 325 XXV LIGHTING--A FINE ART? 341 READING REFERENCES 357 INDEX 359 LIST OF ILLUSTRATIONS Light and Liberty _Frontispiece_ FACING PAGE Primitive fire-baskets 16 Crude splinter-holders 16 Early open-flame oil and grease lamps 17 A typical metal multiple-wick open-flame oil-lamp 32 A group of oil-lamps of two centuries ago 33 Lamps of a century or two ago 56 Elaborate fixtures of the age of candles 57 Flame arc 128 Direct current arc 128 On the testing-racks of the manufacturer of incandescent filament lamps 129 Carbon-dioxide tube for accurate color-matching 160 The Moore nitrogen tube 160 Modern street lighting 161 A completed lighthouse lens 176 Torro Point Lighthouse, Panama Canal 176 American search-light position on Western Front in 1919 177 American standard field search-light and power unit 177 Signal-light for airplane 232 Trench light-signaling outfit 232 Aviation field light-signal projector 232 Signal search-light for airplane 232 Unsafe, unproductive lighting worthy of the dark ages 233 The same factory made safe, cheerful, and more productive by modern lighting 233 Locomotive electric headlight 240 Search-light on a fire-boat 240 Building ships under artificial light at Hog Island Shipyard 241 Artificial light in photography 256 Sterilizing water with radiant energy from quartz mercury-arcs 257 Judging color under artificial daylight 272 Artificial daylight 273 Fireworks and illuminated battle-fleet at Hudson-Fulton Celebration 288 Fireworks exhibition on May Day at Panama-Pacific Exposition 289 The new flood lighting contrasted with the old outline lighting 304 Niagara Falls flooded with light 305 Artificial light honoring those who fell and those who returned 320 The expressiveness of light in churches 321 Obtaining two different moods in a room by a portable lamp which supplies direct and indirect components of light 336 The lights of New York City 337 Artificial light in community affairs 352 Panama-Pacific Exposition 353 ARTIFICIAL LIGHT I LIGHT AND PROGRESS The human race was born in slavery, totally subservient to nature. The earliest primitive beings feasted or starved according to nature's bounty and sweltered or shivered according to the weather. When night fell they sought shelter with animal instinct, for not only were activities almost completely curtailed by darkness but beyond its screen lurked many dangers. It is interesting to philosophize upon a distinction between a human being and the animal just below him in the scale, but it may serve the present purpose to distinguish the human being as that animal in whom there is an unquenchable and insatiable desire for independence. The effort to escape from the bondage of nature is not solely a human instinct; animals burrow or build retreats through the instinct of self-preservation. But this instinct in animals is soon satisfied, whereas in human beings it has been leading ever onward toward complete emancipation. The progress of civilization is a long chain of countless achievements each one of which has increased man's independence. Early man perhaps did not conceive the idea of fire and then set out to produce it. His infant mind did not operate in this manner. But when he accidentally struck a spark, produced fire by friction, or discovered it in some other manner, he saw its possibility. It is thrilling to picture primitive man at his first bonfire, enjoying the warmth, or at least interested in it. But how wonderful it must have become as twilight's curtain was drawn across the heavens! This controllable fire emitted _light_. It is easy to imagine primitive man pondering over this phenomenon with his sluggish mind. Doubtless he cautiously picked up a flaming stick and timidly explored the crowding darkness. Perhaps he carried it into his cave and behold! night had retreated from his abode! No longer was it necessary for him to retire to his bed of leaves when daylight failed. The fire not only banished the chill of night but was a power over darkness. Viewed from the standpoint of civilization, its discovery was one of the greatest strides along the highway of human progress. The activities of man were no longer bounded by sunrise and sunset. The march of civilization had begun. In the present age of abundant artificial light, with its manifold light-sources and accessories which have made possible countless applications of light, mankind does not realize the importance of this comfort. Its wonderful convenience and omnipresence have resulted in indifference toward it by mankind in general, notwithstanding the fact that it is essential to man's most important and educative sense. By extinguishing the light and pondering upon his helplessness in the resulting darkness, man may gain an idea of its overwhelming importance. Those unfortunate persons who suffer the terrible calamity of blindness after years of dependence upon sight will testify in heartrending terms to the importance of light. Milton, whose eyesight had failed, laments, O first created beam and thou great Word "Let there be light," and light was over all, Why am I thus bereaved thy prime decree? Perhaps only through a similar loss would one fully appreciate the tremendous importance of light to him, but imagination should be capable of convincing him that it is one of the most essential and pleasure-giving phenomena known to mankind. A retrospective view down the vista of centuries reveals by contrast the complexity with which artificial light is woven into human activities of the present time. Written history fails long before the primitive races are reached, but it is safe to trust the imagination to penetrate the fog of unwritten history and find early man huddled in his cave as daylight wanes. Impelled by the restless spirit of progress, this primitive being grasped the opportunity which fire afforded to extend his activities beyond the boundaries of daylight. The crude art upon the walls of his cave was executed by the flame of a smoking fagot. The fire on the ledge at the entrance to his abode became a symbol of home, as the fire on the hearth has symbolized home and hospitality throughout succeeding ages. The accompanying light and the protection from cold combined to establish the home circle. The ties of mated animals expanded through these influences to the bonds of family. Thus light was woven early into family life and has been throughout the ages a moralizing and civilizing influence. To-day the residence functions as a home mainly under artificial light, for owing to the conditions of living and working, the family group gathers chiefly after daylight has failed. From the pine knot of primitive man to the wonderfully convenient light-sources of to-day there is a great interval, consisting, as appears retrospectively, of small and simple steps long periods apart. Measured by present standards and achievements, development was slow at first and modern man may be inclined to impatience as he views the history of light and human progress. But the achievements of early centuries, which appear so simple at the present time, were really great accomplishments when considered in the light of the knowledge of those remote periods. Science as it exists to-day is founded upon proved facts. The scientist, equipped with a knowledge of physical and chemical laws, is led by his imagination into the darkness of the unexplored unknown. This knowledge illuminates the pathway so that hypotheses are intelligently formed. These evolve into theories which are gradually altered to fit the accumulating facts, for along the battle area of progress there are innumerable scouting-parties gaining secrets from nature. These are supported by individuals and by groups, who verify, amplify, and organize the facts, and they in turn are followed by inventors who apply them. Liaison is maintained at all points, but the attack varies from time to time. It may be intense at certain places and other sectors may be quiet for a time. There are occasional reverses, but the whole line in general progresses. Each year witnesses the acquirement of new territory. It is seen that through the centuries there is an ever-growing momentum as knowledge, efficiency, and organization increase the strength of this invading army of scientists and inventors. The burning fagot rescued mankind from the shackles of darkness, and the grease-lamp and tallow-candle have done their part. Progress was slow in those early centuries because the great minds of those ages philosophized without a basis of established facts: scientific progress resulted more from an accumulation of accidental discoveries than by a directed attack of philosophy supported by the facts established by experiment. It was not until comparatively recent times, at most three centuries ago, that the great intellects turned to systematically organized scientific research. Such men as Newton laid the foundation for the tremendous strides of to-day. The store of facts increased and as the attitude changed from philosophizing to investigating, the organized knowledge grew apace. All of this paved the way for the momentous successes of the present time. The end is not in sight and perhaps never will be. The unexplored region extends to infinity and, judged by the past, the momentum of discovery will continue to increase for ages to come, unless the human race decays through the comfort and ease gained from utilizing the magic secrets which are constantly being wrested from nature. Among the achievements of science and invention, the production and application of artificial light ranks high. As an influence upon civilization, no single achievement surpasses it. Without artificial light, mankind would be comparatively inactive about one half its lifetime. To-day it has been fairly well established that the human organism can flourish on eight hours' sleep in a period of twenty-four hours. Another eight hours spent in work should settle man's obligation to the world. The remaining hours should be his own. Artificial light has made such a distribution of time possible. The working-periods in many cases may be arranged in the interests of economy, which often means continuous operations. The sun need not be considered when these operations are confined to interiors or localized outdoors. Thus, artificial light has been an important factor in the great industrial development of the present time. Man now burrows into the earth, navigates under water, travels upon the surface of land and sea, and soars among the clouds piloted by light of his own making. Progress does not halt at sunset but continues twenty-four hours each day. Building, printing, manufacturing, commerce, and other activities are prosecuted continuously, the working-shifts changing at certain periods regardless of the rising or setting sun. Adequate artificial lighting decreases spoilage, increases production, and is a powerful factor in the prevention of industrial accidents. It has ever been true since the advent of artificial light that the intellect has been largely nourished after the completion of the day's work. The highly developed artificial lighting of the present time may account for much of the vast industry of publication. Books, magazines, and newspapers owe much to convenient and inexpensive artificial light, for without it fewer hours would be available for recreation and advancement through reading. Schools, libraries, and art museums may be attended at night for the betterment of the human race. The immortal Lincoln, it is said, gained his early education largely by the light of the fireplace. But all were not endowed with the persistence of Lincoln, so that illiteracy was more common in his day than in the present age of adequate illumination. The theatrical stage not only depends for its effectiveness upon artificial light but owes its existence and development largely to this agency. In the moving-picture theater, pictures are projected upon the screen by means of it and even the production of the pictures is independent of daylight. These and a vast number of recreational activities owe much, and in some cases their existence, to artificial light. Not many centuries ago the streets at night were overrun by thieves and to venture outdoors after dark was to court robbery and even bodily harm. In these days of comparative safety it is difficult to realize the influence that abundant illumination has had in increasing the safety of life and property. Maeterlinck in his poetical drama, "The Bluebird," appropriately has made _Light_ the faithful companion of mankind. The Palace of Night, into which _Light_ is not permitted to enter, is the abode of many evils. Thus the poet has played upon the primitive instincts of the impressiveness of light and darkness. By combining the symbolism of light, color, and darkness with the instincts which have been inherited by mankind from its superstitious ancestry of the age of mythology, another field of application of artificial light is opened. Light has gradually assumed such attributes as truth, knowledge, progress, enlightenment. Throughout the early ages light was more or less worshiped and thus artificial lights became woven in many religious ceremonies. Some of these have persisted to the present time. The great pageants of peace celebrations and world's expositions appropriately feature artificial light. In drawing upon the potentiality of the expressiveness and impressiveness of light and color, artificial light is playing a major part. Doubtless the future generations will be entertained by gorgeous symphonies of light. Experiments are performed in this direction now and then, and it is reasonable to expect that after many centuries of cultivation of the appreciation of light-symphonies, these will take a place among the arts. The elaborate and complicated music of the present time is appreciated by civilized nations only after many centuries of slow cultivation of taste and understanding. Light-therapy is to-day a distinct science and art. The germicidal action of light-rays and of some of the invisible rays which ordinarily accompany the luminous rays is well proved. Wounds are treated effectively and water is sterilized by the ultraviolet radiant energy in modern artificial illuminants. Thousands of lighthouses, light-ships, and light-buoys are scattered along sea-coasts, rivers, and channels. They guide the wheelman and warn the lookout of shoals and reefs. Some of these send forth flashes of light whose intensities are measured in millions of candle-power. Many are unattended for days and even months. These powerful lights dominated by automatic mechanisms have replaced the wood-fires which were maintained a few centuries ago upon certain prominent points. Signal-lights now guide the railroad train through the night. A burning flare dropped from the rear of a train keeps the following train at a safe distance. Huge search-lights penetrate the night air for many miles. When these are equipped with shutters, a code may be flashed from one ship to another or between the vessel and land. A code from a powerful search-light has been read a hundred miles away because the flashes were projected upon a layer of high clouds and were thus visible far beyond the horizon. Artificial light played its part in the recent war. Huge search-light equipments were devised for portability. This mobile apparatus was utilized against enemy aircraft and in various other ways. Small hand-lamps are used to send out a pencil of light as directed by a pair of sights and the code is flashed by means of a trigger. Raiding-parties are no longer concealed by the curtain of darkness, for rockets and star-shells are used to illuminate large areas. Flares sent upward to drift slowly downward supported by parachutes saved and cost many lives during the recent war. Rockets are used by ships in distress and also by beleaguered troops. Experiments are being prosecuted to ascertain the possibilities of artificial light in the forcing of plant-growth, and even chickens are made to work longer hours by its use. Artificial light is now modified in color or spectral character to meet many requirements. Daylight has been reproduced in spectral quality so that certain processes requiring accurate discrimination of color are now prosecuted twenty-four hours a day under artificial daylight. Colored light is made of the correct quality which does not affect photographic plates of various sensibilities. Monochromatic light is utilized in photo-micrography for the best rendition of detail. Light-waves have been utilized as standards of length because they are invariable and fundamental. Numerous other interesting adaptations of artificial light are in daily use. This is in reality the age of artificial light, for mankind has not only become independent of daylight in certain respects, but has improved upon natural light. The controllability of artificial light makes it superior to natural light in many ways. In fact, uses have been made of artificial light which are impossible with natural light. Light-sources may be made of a vast variety of shapes, and those may be transported wherever desired. They may be equipped with reflectors and other optical devices to direct or to diffuse the light as required. Thus, artificial light to-day has numerous advantages over light which has been furnished by the Creator. It is sometimes stated that it can never compete with daylight in cheapness, inasmuch as the latter costs nothing. But this is not true. Even in the residence, daylight costs something, because windows are more expensive than plain walls. The expense of washing windows is an appreciable percentage of the cost of gas or electricity. And there is window-breakage to be considered. In the more elaborate buildings of the congested portions of cities, daylight is satisfactory a lesser number of hours than in the outlying districts. In some stores, offices, and factories artificial light is used throughout the day. Still, the daylighting-equipment is installed and maintained. Furthermore, when it is considered that much expensive area is given to light-courts and much valuable wall space to windows, it is seen that the cost of daylight in congested cities is in reality considerable. Of course, the daylighting-equipment has value in ventilating, but ventilation may be taken care of in a very satisfactory manner as a separate problem. The cost of skylights in museums and other large buildings is far greater than that of ordinary ceilings and walls, and the extra allowance for heating is appreciable. The expense of maintenance of some skylights is considerable. Thus it is seen that the cost and maintenance of daylighting-equipment, the loss of valuable rental space and of wall area, and the increased expense of heating are factors which challenge the statement that daylight costs nothing. In fact, it is not surprising to find that occasionally the elimination of daylighting--the reliance upon artificial light alone--has been seriously contemplated. When the possibilities of the latter are considered, it is reasonable to expect that it will make greater and greater inroads and that many buildings of the future will be equipped solely with artificial-lighting systems. Naturally, with the tremendous development of artificial light during the present age, a new profession has arisen. The lighting expert is evolving to fill the needs. He is studying the problems of producing and utilizing artificial illumination. He deals with the physics of light-production. His studies of utilization carry him into the vast fields of physiology and psychology. His is a profession which eventually will lead into numerous highways and byways of enterprise, because the possibilities of lighting extend into all those activities which make their appeal to consciousness through the doorway of vision. These possibilities are limited only by the boundaries of human endeavor and in the broadest sense extend even beyond them, for light is one of the most prominent agencies in the scheme of creation. It contributes largely to the safety, the efficiency, and the happiness of civilized beings and beyond all it is a powerful civilizing agency. II THE ART OF MAKING FIRE Scattered over the earth at the present time various stages of civilization are to be found, from the primitive savages to the most highly cultivated peoples. Although it is possible that there are tribes of lowly beings on earth to-day unfamiliar with fire or ignorant of its uses, savages are generally able to make fire. Thus the use of fire may serve the purpose of distinguishing human beings from the lower animals. Surely the savage of to-day who is unable to kindle fire or who possesses a mind as yet insufficiently developed to realize its possibilities, is quite at the mercy of nature's whims. He lives merely by animal prowess and differs little in deeds and needs from the beasts of the jungle. In this imaginary journey to the remote regions beyond the outskirts of civilization it soon becomes evident that the development of artificial light may be a fair measure of civilization. In viewing the development of artificial light it is seen that preceding the modern electrical age, man depended universally upon burning material. Obviously, the course of civilization has been highly complex and cannot be symbolized adequately by the branching tree. From its obscure beginning far in the impenetrable fog of prehistoric times, it has branched here and there. These various branches have been subjected to many different influences, with the result that some flourished and endured, some retrogressed, some died, some went to seed and fell to take root and to begin again the upward climb. The ultimate result is the varied civilization of the present time, a study of which aids in penetrating the veil that obscures the ages of unrecorded writing. Likewise, material relics of bygone ages supply some threads of the story of human progress and mythology aids in spanning the misty gap between the earliest ages of man and the period when historic writings were begun. Throughout these various stages it becomes manifest that the development of artificial light is associated with the progress of mankind. According to a certain myth, Prometheus stole fire from heaven and brought this blessing to earth. Throughout the mythologies of various races, fire and, as a consequence, light have been associated with divinity. They have been subjects of worship perhaps more generally than anything else, and these early impressions have survived in the ceremonial uses of light and fire even to the present time. The origin of fire as represented in any of the myths of the superstitious beings of early ages is as suitable as any other, inasmuch as definite knowledge is unavailable. Active volcanoes, spontaneous combustion, friction, accidental focusing of the sun's image, and other means may have introduced primitive beings to fire. A study of savage tribes of the present age combined with a survey of past history of mythology, of material relics, and of the absence of lamps or other lighting utensils leads to the conclusion that the earliest source of light was the wood fire. [Illustration: PRIMITIVE FIRE-BASKETS] [Illustration: CRUDE SPLINTER-HOLDERS] [Illustration: EARLY OPEN-FLAME OIL AND GREASE LAMPS] Even to-day the savages of remote lands have not advanced further than the wood-fire stage, and they may be found kneeling upon the ground energetically but skilfully rubbing sticks together until the friction kindles a fire. In using these fire-sticks they convert mechanical energy into heat energy. This is a fundamental principle of physics, employed by them as necessity demands, but they are totally ignorant of it as a scientific law. The things which these savages learn are the result of accidental discovery. Until man pondered over such simple facts and coördinated them so that he could extend his knowledge by general reasoning, his progress could not be rapid. But the sluggish mind of primitive man is capable of devising improvements, however slowly, and the art of making fire by means of rubbing fire-sticks gradually became more refined. Mechanical improvements resulted from experience, with the consequence that finally one stick was rubbed to and fro in a groove, or was rapidly twirled between the palms of the hands while one end was pressed firmly into a hole in a piece of wood. In the course of a few seconds or a minute, depending upon skill and other conditions, a fire was obtained. It is interesting to note how civilized man is often compelled by necessity to adopt the methods of primitive beings. The rubbing of sticks is an emergency measure of the master of woodcraft at the present time, and the production of fire in this manner is the proud accomplishment or ambition of every Boy Scout. Where only such crude means of kindling fire were available it became the custom in some cases to maintain a fire burning continuously in a public place. Around this pyrtaneum the various civil, political, and religious affairs were carried on by the light and warmth of the public fire. Many quaint customs evolved, apparently, from this ancient procedure. The tinder-box of modern centuries doubtless originated in very early times, for it is inconceivable that the earliest beings did not become aware of the production of sparks when certain stones were struck together. In the stone age, when human beings spent much of their time chiseling implements and utensils from stone by means of tools of the same substance, it appears certain that this means of producing fire was ever apparent. Many of their sharp implements, such as knives and arrow-heads, were made of quartz and similar material and it is likely that the use of two pieces of quartz for producing a spark originated in those remote periods. Alaskan and Aleutian tribes are known to have employed two pieces of quartz covered with native sulphur. When these were struck together with skill, excellent sparks were obtained. Later, when iron and steel became available, the more modern tinder-box was developed. An early application of the flint-and-steel principle was made by certain Esquimo tribes who obtained fire by striking a piece of quartz against a piece of iron pyrites. The latter is a yellow sulphide of iron, of crystalline form, best known as "fool's gold." Doubtless, the more primitive beings used dried grass, leaves, and moss as inflammable material upon which the sparks were showered. In later centuries the tinder-box was filled with charred grass, linen, and paper. There was a long interval between the development of fire-sticks and that of the tinder-box as measured by the progress of civilization. During recent centuries ordinary brown paper soaked in saltpeter and dried was utilized satisfactorily as an inflammable material. Such devices have been employed in past ages in widely separated regions of the earth. Elaborate specimens of tinder-boxes from Jamaica, Japan, China, Europe, and various other countries are now reposing in the collections in the possession of museums and of individuals. If the radiant energy from the sun is sufficiently concentrated upon inflammable material, the latter will ignite. Such concentration may be achieved by means of a convex lens or a concave mirror. This method of producing fire does not antedate the more primitive methods such as striking quartz or rubbing wooden sticks, because the materials required are not readily found or prepared, but it is of very remote origin. Aristophanes in his comedy "The Clouds," which is a satire aimed at the science and philosophy of his period (488-385 B. C.), mentions the "burning lens." Nearly every one is familiar with an achievement attributed to Archimedes in which he destroyed the ships at Syracuse by focusing the image of the sun upon them by means of a concave mirror. The ancient Egyptians were proficient in the art of glass-making, so it is likely that the "burning-glass" was employed by them. Even a crude lens of glass will focus an image of the sun sufficiently well to cause inflammable material to ignite. The energy in sunlight varies enormously, even on clear days, because the water-vapor in the atmosphere absorbs some of the radiant energy emitted by the sun. This absorbed radiation is chiefly known as infra-red energy, which does not arouse the sensation of light. When the water-vapor content of the atmosphere is high, the sun, though it may appear as bright to the eye, in reality is not as hot as it would be if the water-vapor were not present. However, a fire may be kindled by concentrating only the visible rays in sunlight because of the enormous intensity of sunlight. A convex lens fashioned from ice by means of a sharp-edged stone and finally shaped by melting the surfaces as they are rubbed in the palms of the hands, will kindle a fire in highly inflammable material if the sun is high and the atmosphere is fairly clear. Burning-glasses are used to a considerable extent at the present time in certain countries and it is reported that British soldiers were supplied with them during the Boer War. Indicative of the predominant use to which the glass lens was applied in the past is the employment of the term "burning-glass" instead of lens in the scientific writings as late as a century or two ago. As civilization advanced, leading intellects began to inquire into the mysteries of nature and the periods of pure philosophy gave way to an era of methodical research. Alchemy and superstition began to retire before the attacks of those pioneers who had the temerity to believe that the scheme of creation involved a vast network of invariable laws. In this manner the powerful sciences of physics and chemistry were born a few centuries ago. Among other things the production of fire and light received attention and the "dark ages" were doomed to end. The crude, uncertain, and inconvenient methods of making fire were replaced by steadily improving scientific devices. Matches were at first cumbersome, dangerous, and expensive, but these gradually evolved into the safety matches of the present time. Although they were primarily intended for lighting fires and various kinds of lamps, billions of them are now used yearly as convenient light-sources. Smoldering hemp or other material treated with niter and other substances was an early form of match used especially for discharging firearms. The modern wax-taper is an evolutionary form of this type of light-source. Phosphorus has long played a dominant rôle in the preparation of matches. The first attempt at making them in their modern form appears to have occurred about 1680. Small pieces of phosphorus were used in connection with small splints of wood dipped in sulphur. This type of match did not come into general use until after the beginning of the nineteenth century, owing to its danger and expense. White or yellow phosphorus is a deadly poison; therefore the progress of the phosphorus match was inhibited until the discovery of the relatively harmless form known as red phosphorus. The first commercial application of this form was made in about 1850. An early ingenious device consisted of a piece of phosphorus contained in a tube. A piston fitted snugly into the tube, by means of which the air could be compressed and the phosphorus ignited. Sulphur matches were ignited from the burning tinder, the latter being fired by flint and steel. In 1828 another form of match consisted of a glass tube containing sulphuric acid and surrounded by a mixture of chlorate of potash and sugar. A pair of nippers was supplied with each box of these "matches," by means of which the tip of the glass tube could be broken off. This liberated the acid, which upon mixing with the other ingredients set fire to them. To this contrivance a roll of paper was attached which was ignited by the burning chemicals. The lucifer or friction matches appeared in about 1827, but successful phosphorus matches were first made in about 1833. The so-called safety match of the present time was invented in the year 1855. To-day, the total daily output of matches reaches millions and perhaps billions. Automatic machinery is employed in preparing the splints of wood and in dipping them into molten paraffin wax and finally into the igniting composition. During recent years the principle of the tinder-box has been revived in a device in which sparks are produced by rubbing the mineral cerite (a hydrous silicate of cerium and allied metals) against steel. These sparks ignite a gas-jet or a wick soaked in a highly inflammable liquid such as gasolene or alcohol. This device is a tinder-box of the modern scientific age. Naturally with the advent of electricity, electrical sparks came into use for lighting gas-jets and mantles and in isolated instances they have served as light-sources. Doubtless, every one is familiar with the parlor stunt of igniting a gas-jet from the discharge from the finger-tips of static electricity accumulated by shuffling the feet across the floor-rug. Although many of these methods and devices have been used primarily for making fire, they have served as emergency or momentary light-sources. In the outskirts of civilization some of them are employed at the present time and various modern light-sources require a method of ignition. III PRIMITIVE LIGHT-SOURCES Many are familiar with the light of the firefly or of its larvæ, the glow-worm, but few persons realize that a vast number of insects and lower organisms are endowed with the superhuman ability of producing light by physiological processes. Apparently the chief function of these lighting-plants within the living bodies is not to provide light in the sense that the human being uses it predominantly. That is, these wonderful light-sources seem to be utilized more for signaling, for luring prey, and for protection than for strictly illuminating-purposes. Much study has been given to the production of light by animals, because the secrets will be extremely valuable to mankind. As one floats over tide-water on a balmy evening after dark and watches the pulsating spots of phosphorescent light emitted by the lowly jellyfishes, his imaginative mood formulates the question, "Why are these lowly organisms endowed with such a wonderful ability?" Despite his highly developed mind and body and his boasted superiority, man must go forth and learn the secrets of light-production before he may emancipate himself from darkness. If man could emit light in relative proportion to his size as compared with the firefly, he would need no other torch in the coal-mine. How independent he would be in extreme darkness where his adapted eyes need only a feeble light-source! Primitive man, desiring a light-source and having no means of making fire, imprisoned the glowing insects in a perforated gourd or receptacle of clay, and thus invented the first lantern perhaps before he knew how to make fire. The fireflies of the West Indies emit a continuous glow of considerable luminous intensity and the natives have used these imprisoned insects as light-sources. Thus mankind has exhibited his superiority by adapting the facilities at hand to the growing requirements which his independent nature continuously nourished. His insistent demand for independence in turn has nourished his desire to learn nature's secrets and this desire has increased in intensity throughout the ages. The act of imprisoning a glowing insect was in itself no greater stride along the highway of progress than the act of picking a tasty fruit from its tree. However, the crude lantern perhaps directed his primitive mind to the possibilities of artificial light. The flaming fagot from the fire was the ancestor of the oil-lamp, the candle, the lantern, and the electric flash-light. It is a matter of conjecture how much time elapsed before his feeble intellect became aware that resinous wood afforded a better light-source than woods which were less inflammable. Nevertheless, pine knots and similar resinous pieces of wood eventually were favored as torches and their use has persisted until the present time. In some instances in ancient times resin was extracted from wood and burned in vessels. This was the forerunner of the grease-and the oil-lamp. In the woods to-day the craftsman of the wilds keeps on the lookout for live trees saturated with highly inflammable ingredients. Viewed from the present age, these smoking, flickering light-sources appear very crude; nevertheless they represent a wide gulf between their users and those primitive beings who were unacquainted with the art of making fire. Although the wood fire prevailed as a light-source throughout uncounted centuries, it was subjected to more or less improvement as civilization advanced. When the wood fire was brought indoors the day was extended and early man began to develop his crude arts. He thought and planned in the comfort and security of his cave or hut. By the firelight he devised implements and even decorated his stone surroundings with pictures which to-day reveal something of the thoughts and activities of mankind during a civilization which existed many thousand years ago. When it was too warm to have a roaring fire upon the hearth, man devised other means for obtaining light without undue warmth. He placed glowing embers upon ledges in the walls, upon stone slabs, or even upon suspended devices of non-inflammable material. Later he split long splinters of wood from pieces selected for their straightness of grain. These burning splinters emitting a smoking, feeble light were crude but they were refinements of considerable merit. A testimonial of their satisfactoriness is their use throughout many centuries. Until very recent times the burning splinter has been in use in Scotland and in other countries, and it is probable that at present in remote districts of highly civilized countries this crude device serves the meager needs of those whose requirements have been undisturbed by the progress of civilization. Scott, in "The Legend of Montrose," describes a table scene during a feast. Behind each seat a giant Highlander stood, holding a blazing torch of bog-pine. This was also the method of lighting in the Homeric age. Crude clay relics representing a human head, from the mouth of which the wood-splinters projected, appear to corroborate the report that the flaming splinter was sometimes held in the mouth in order that both hands of a workman would be free. Splinter-holders of many types have survived, but most of them are of the form of a crude pedestal with a notch or spring clip at its upper end. The splinter was held in this clip and burned for a time depending upon its length and the character of the wood. It was the business of certain individuals to prepare bundles of splinters, which in the later stages of civilization were sold at the market-place or from house to house. Those who have observed the frontiersman even among civilized races will be quite certain that the wood for splinters was selected and split with skill, and that the splinters were burned under conditions which would yield the most satisfactory light. It is a characteristic of those who live close to nature, and are thus limited in facilities, to acquire a surprising efficiency in their primitive activities. An obvious step in the use of burning wood as a light-source was to place such a fire on a shelf or in a cavity in the wall. Later when metal was available, gratings or baskets were suspended from the ceiling or from brackets and glowing embers or flaming chips were placed upon them. Some of these were equipped with crude chimneys to carry away the smoke, and perhaps to increase the draft. In more recent centuries the first attempt at lighting outdoor public places was by means of metal baskets in which flaming wood emitted light. It was the duty of the watchman to keep these baskets supplied with pine knots. In early centuries street-lighting was not attempted, and no serious efforts worthy of consideration as adequate lighting were made earlier than about a century ago. As a consequence the "link-boy" came into existence. With flaming torch he would escort pedestrians to their homes on dark nights. This practice was in vogue so recently that the "link-boy" is remembered by persons still living. In England the profession appears to have existed until about 1840. Somewhat akin to the wood-splinter, and a forerunner of the candle, was the rushlight. In burning wood man noticed that a resinous or fatty material increased the inflammability and added greatly to the amount of light emitted. It was a logical step to try to reproduce this condition by artificial means. As a consequence rushes were cut and soaked in water. They were then peeled, leaving lengths of pith partially supported by threads of the skin which were not stripped off. These sticks of pith were placed in the sun to bleach and to dry, and after they were thoroughly dry they were dipped in scalding grease, which was saved from cooking operations or was otherwise acquired for the purpose. A reed two or three feet long held in the splinter-holder would burn for about an hour. Thus it is seen that man was beginning to progress in the development of artificial light. In developing the rushlight he was laying the foundation for the invention of the candle. Pliny has mentioned the burning of reeds soaked in oil as a feature of funeral rites. Many crude forerunners of the candle were developed in various parts of the world by different races. For example, the Malays made a torch by wrapping resinous gum in palm leaves, thus devising a crude candle with the wick on the outside. Many primitive uses of vegetable and animal fats were forerunners of the oil-lamp. In the East Indies the candleberry, which contains oily seeds, has been burned for light by the natives. In many cases burning fish and birds have served as lamps. In the Orkney Islands the carcass of a stormy petrel with a wick in its mouth has been utilized as a light-source, and in Alaska a fish in a split stick has provided a crude torch for the natives. These primitive methods of obtaining artificial light have been employed for centuries and many are in use at the present time among uncivilized tribes and even by civilized beings in the remote outskirts of civilization. Surely progress is limited where a burning fish serves as a torch, or where, at best, the light-sources are feeble, smoking, flickering, and ill-smelling! Progress insisted upon a light-source which was free from the defects of the crude devices already described and the next developments were improvements to the extent at least that combustion was more thorough. The early oil-lamps and candles did not emit much smoke, but they were still feeble light-sources and not always without noticeable odors. Nevertheless, they marked a tremendous advance in the production of artificial light. Although they were not scientific developments in the modern sense, the early oil-lamp and the candle represented the great possibilities of utilizing knowledge rather than depending upon the raw products of nature in unmodified forms. The advent of these two light-sources in reality marked the beginning of the civilization which was destined to progress and survive. Although such primitive light-sources as the flaming splinter and the glowing ember have survived until the present age, lamps consisting of a wick dipped into a receptacle containing animal and vegetable oils have been in use among the more advanced peoples since prehistoric times. Oil-lamps are to be seen in the earliest Roman illustrations. During the height of ancient civilization along the eastern shores of the Mediterranean Sea, elaborate lighting was effected by means of the shallow grease-or oil-lamp. It is difficult to estimate the age in which this form of light-source originated, but some lamps in existence in collections at the present time appear to have been made as early as four or five thousand years before the Christian era. It is noteworthy that such lamps did not differ materially in essential details from those in use as late as a few centuries ago. At first the grease used was the crude fat from animals. Vegetable oils also were burned in the early lamps. The Japanese, for example, extracted oil from nuts. When the demands of civilization increased, extensive efforts were made to obtain the required fats and oils. Amphibious animals of the North and the huge mammals of the sea were slaughtered for their fat, and vegetable sources were cultivated. Later, sperm and colza were the most common oils used by the advanced races. The former is an animal oil obtained from the head cavities of the sperm-whale; the latter is a vegetable oil obtained from rape-seed. Mineral oil was introduced as an illuminant in 1853, and the modern lamp came into use. The grease-and oil-lamps in general were of such a form that they could be carried with ease and they had flat bottoms so that they would rest securely. The simplest forms had a single wick, but in others many wicks dipped into the same receptacle. The early ones were of stone, but later, lamps were modeled from clay or terra cotta and finally from metals. They were usually covered and the wick projected through a hole in the top near the edge. Large stone vases filled with a hundred pounds of liquid fat are known to have been used in early times. As a part of the setting in the celebration of festivals the ancient nations of Asia and Africa placed along the streets bronze vases filled with liquid fat. The Esquimaux to-day use this form of lamp, in which whale-oil and seal blubber is the fuel. Incidentally, these lamps also supply the only artificial heat for their huts and igloos. The heat from these feeble light-sources and from their bodies keeps these natives of the arctics warm within the icy walls of their abodes. Very beautiful oil-lamps of brass, bronze, and pewter evolved in such countries as Egypt. Many of these were designed for and used in religious ceremonies. The oil-lamps of China, Scotland, and other countries in later centuries were improved by the addition of a pan beneath the oil-receptacle, to catch drippings from the wick or oil which might run over during the filling. The Chinese lamps were sometimes made of bamboo, but the Scottish lamps were made of metal. A flat metal lamp, called a crusie, was one of the chief products of blacksmiths and was common in Scotland until the middle of the nineteenth century. This type of lamp was used by many nations and has been found in the catacombs of Rome. The crusie was usually suspended by an iron hook and the flow of oil to the wick could be regulated by tilting. The wick in the Scottish lamps consisted of the pith of rushes, cloth, or twisted threads. These early oil-lamps were almost always shallow vessels into which a short wick was dipped, and it was not until the latter part of the eighteenth century that other forms came into general use. The change in form was due chiefly to the introduction of scientific knowledge when mineral oil was introduced. As early as 1781 the burning of naptha obtained by distilling coal at low temperatures was first discussed, but no general applications were made until a later period. This was the beginning of many marked improvements in oil-lamps, and was in reality the birth of the modern science of light-production. [Illustration: A TYPICAL METAL MULTIPLE-WICK OPEN-FLAME OIL-LAMP] [Illustration: A GROUP OF OIL-LAMPS OF TWO CENTURIES AGO] As the activities of man became more complex he met from his growing store of knowledge the increasing requirements of lighting. In consequence, many ingenious devices for lighting were evolved. For example, in England in the seventeenth century man was already burrowing into the earth for coal and of course encountered coal-gases. These inflammable gases were first known for the direful effects which they so often produced rather than for their useful qualities. Although they were known to miners long before they received scientific attention, the earliest account of them in the Transactions of the Royal Society was presented in the year 1667. A description of early gas-lighting has been reserved for a later chapter, but the foregoing is noted at this point to introduce a novel early method of lighting in coal-mines where inflammable gases were encountered. In discussing this coal-gas another early writer stated that "it will not take fire except by flame" and that "sparks do not affect it." One of the early solutions of the problem of artificial lighting under such conditions is summarized as follows: Before the invention of Sir Humphrey Davy's Safety Lamp, this property of the gas gave rise to a variety of contrivances for affording the miners sufficient light to pursue their operations; and one of the most useful of these inventions was a mill for producing light by sparks elicited by the collision of flint and steel. Such a stream of sparks may appear a very crude and unsatisfactory solution as judged by present standards, but it was at least an ingenious application of the facilities available at that time. Various other devices were resorted to in the coal-mines before the introduction of a safety lamp. In discussing the candle it is necessary again to go back to an early period, for it slowly evolved in the course of many centuries. It is the natural descendant of the rushlight, the grease-lamp, and various primitive devices. Until the advent of the more scientific age of artificial lighting, the candle stood preëminent among early light-sources. It did not emit appreciable smoke or odor and it was conveniently portable and less fragile than the oil-lamp. Candles have been used throughout the Christian era and some authorities are inclined to attribute their origin to the Phoenicians. It is known that the Romans used them, especially the wax-candles, in religious ceremonies. The Phoenicians introduced them into Byzantium, but they disappeared under the Turkish rule and did not come into use again until the twelfth century. The wax-candle was very much more expensive than the tallow-candle until the fifteenth century, when its relative cost was somewhat reduced, bringing it within the means of a greater proportion of the people. Nevertheless it has long been used, chiefly by the wealthy; the departing guest of the early Victorian inn would be likely to find an item on his bill such as this: "For a gentleman who called himself a gentleman, wax-lights, 5/." Poor men used tallow dips or went to bed in the dark. It is interesting to note the importance of the candle in the household budget of early times in various sayings. For example, "The game is not worth the candle," implies that the cost of candle-light was not ignored. In these days little attention is given to the cost of artificial light under similar conditions. If a person "burns a candle at both ends" he is wasteful and oblivious to the consequences of extravagance whether in material goods or in human energy. With the rise of the Christian church, candles came to be used in religious ceremonies and many of the symbolisms, meanings, and customs survive to the present time. Some of the finest art of past centuries is found in the old candlesticks. Many of these antiques, which ofttimes were gifts to the church, have been preserved to posterity by the church. The influence of these lighting accessories is often noted in modern lighting-fixtures, but unfortunately early art often suffers from adaptation to the requirements of modern light-sources, or the eyesight suffers from a senseless devotion to art which results in the use of modern light-sources, unshaded and glaring, in places where it was unnecessary to shade the feeble candle. The oldest materials employed for making candles are beeswax and tallow. The beeswax was bleached before use. The tallow was melted and strained and then cotton or flax fibers were dipped into it repeatedly, until the desired thickness was obtained. In early centuries the pith of rushes was used for wicks. Tallow is now used only as a source of stearine. Spermaceti, a fatty substance obtained from the sperm-whale, was introduced into candle-making in about 1750 and great numbers of men searched the sea to fill the growing demands. Paraffin wax, a mixture of solid hydrocarbons obtained from petroleum, came into use in 1854 and stearine is now used with it. The latter increases the rigidity and decreases the brittleness of the candle. Some of the modern candles are made of a mixture of stearine and the hard fat extracted from cocoanut-oil. Modern candles vary in composition, but all are the product of much experience and of the application of scientific knowledge. The wicks are now made chiefly of cotton yarn, braided or plaited by machinery and chemically treated to aid in complete combustion when the candle is burned. Their structure is the result of long experience and they are now made so that they bend and dip into the molten fuel and are wholly consumed. This eliminates the necessity of trimming. Candles have been made in various ways, including dipping, pouring, drawing, and molding. Wax-candles are made by pouring, because wax cannot be molded satisfactorily. Drawing is somewhat similar to dipping, except that the process is more or less continuous and is carried out by machinery. Molding, as the term implies, involves the use of molds, of the size and shape desired. The candlestick evolved from the most primitive wooden objects to elaborately designed and decorated works of art. The primitive candlestick was crude and was no more than a holder of some kind for keeping the candle upright. Later a form of cup was attached to the stem of the holder, to catch the dripping wax or fat. The latter improvement has persisted throughout the centuries. The modern candle is by no means an unsatisfactory light-source. Those who have had experience with it in the outskirts of civilization will testify that it possesses several desirable characteristics. Supplies of candles are transported without difficulty; the lighted candle is easily carried about; and the light in a quiescent atmosphere is quite satisfactory, if common sense is used in shading and placing the candle. Although in a sense a primitive light-source, it is a blessing in many cases and, incidentally, it is extensively used to-day in industries, in religious ceremonies, as a decorative element at banquets, and in the outposts of civilization. This account of the evolution of light-sources has crossed the threshold of what may be termed modern scientific light-production in the case of the candle and the oil-lamp. There is a period of a century or more during which scientific progress was slow, but those years paved the way for the extraordinary developments of the last few decades. IV THE CEREMONIAL USE OF LIGHT Inasmuch as the symbolisms and ceremonial uses of light originated in the childhood of the human race and were nourished throughout the age of mythology, the early light-sources are associated more with this phase of artificial light than modern ones. For this reason it appears appropriate to present this discussion before entering into the later stages of the development and utilization of artificial light. Furthermore, many of the traditions of lighting at the present time are survivors of the early ages. Lighting-fixtures show the influence of this byway of lighting, and in those cases where the ceremonial use of light has survived to the present time, modern light-sources cannot be employed wisely in replacing more primitive ones without consideration of the origin and existence of the customs. In fact, candles are likely to be used for hundreds of years to come, owing to the sentiment connected with them and to the established customs founded upon centuries of traditional use. Doubtless, the sun as a source of heat and light and of the blessings which these bring to earth, is responsible largely for the divine significance bestowed upon light. Darkness very deservingly acquired many uncomplimentary attributes, for danger lurked behind its veil and it was the suitable abode of evil spirits. It harbored all that was the antithesis of goodness, happiness, and security. Light naturally became sacred, life-giving, and symbolic of divine presence. Fire was to primitive beings the most impressive phenomenon over which they had any control, and it was sufficiently mysterious in its operation to warrant a connection with the supernatural. Thus it was very natural that these earlier beings worshiped it as representing divine presence. The sun, as Ra, was one of the chief gods of the ancient Egyptians; and the Assyrians, the Babylonians, the ancient Greeks, and many other early peoples gave a high place to this deity. Among simpler races the sun was often the sole object of worship, and those peoples who worship Light as the god of all, in a sense are not far afield. Fire-worshipers generally considered fire as the purest representation of heavenly fire, the origin of everything that lives. Light was considered such a blessing that lamps were buried with the dead in order that spirits should be able to have it in the next world. This custom has prevailed widely but the fact that the lamps were unlighted indicates that only the material aspect was considered. It is interesting to note that the lamps and other light-sources in pagan temples and religious processions were not symbolical but were offerings to the gods. In later centuries a deeper symbolical meaning became attached to light and burning lamps were placed upon the tombs of important personages. The burying of lamps with the dead appears to have originated in Asia. The Phoenicians and Romans apparently continued the custom, but no traces of it have been found in Greece and Egypt. Fire and light have been closely associated in various religious creeds and their ceremonies. The Hindu festival in honor of the goddess of prosperity is attended by the burning of many lamps in the temples and homes. The Jewish synagogues have their eternal lamps and in their rituals fire and light have played prominent rôles. The devout Brahman maintains a fire on the hearth and worships it as omniscient and divine. He expects a brand from this to be used to light his funeral pyre, whose fire and light will make his spirit fit to enter his heavenly abode. He keeps a fire burning on the altar, worships Agni, the god of fire, and makes fire sacrifices on various occasions such as betrothals and marriages. To the Mohammedans lighted lamps symbolize holy places, and the Kaaba at Mecca, which contains a black stone supposed to have been brought from heaven, is illuminated by thousands of lamps. Many of the uses to which light was put in ancient times indicate its rarity and sacred nature. Doubtless, the increasing use of artificial light at festivals and celebrations of the present time is partly the result of lingering customs of bygone centuries and partly due to a recognition of an innate appeal or attribute of light. Certainly nothing is more generally appropriate in representing joy and prosperity. Throughout all countries ancient races had woven natural light and fire into their rites and customs, so it became a natural step to utilize artificial light and fire in the same manner. It would be tedious and monotonous to survey the vast field of ancient worship of light, for the underlying ideas are generally similar. The mythology of the Greeks is illustrative of the importance attached to fire and light by the cultivated peoples of ancient times. The myth of Prometheus emphasizes the fact that in those remote periods fire and light were regarded as of prime importance. According to this myth, fire and light were contained in heaven and great cunning and daring were necessary in order to obtain it. Prometheus stole this heavenly fire, for which act he was chained to the mountain and made to suffer. The Greeks mark this event as the beginning of human civilization. All arts are traced to Prometheus, and all earthly woe likewise. As past history is surveyed it appears natural to think of scientific men who have become martyrs to the quest of hidden secrets. They have made great sacrifices for the future benefit of civilization and not a few of them have endured persecution even in recent times. The Greeks recognized that a new era began with the acquisition of artificial light. Its divine nature was recognized and it became a phenomenon for worship and a means for representing divine presence. The origin of fire and light made them holy. The fire on the altar took its place in religious rites and there evolved many ceremonial uses of lamps, candles, and fire. The Greeks and Romans burned sacred lamps in the temples and utilized light and fire in many ceremonies. The torch-race, in which young men ran with lighted torches, the winner being the one who reached the goal first with his torch still alight, originated in a Grecian ceremony of lighting the sacred fire. There are many references in ancient Roman and Grecian literature to sacred lamps burning day and night in sanctuaries and before statues of gods and heroes. On birthdays and festivals the houses of the Romans were specially ornamented with burning lamps. The Vestal Virgins in Rome maintained the sacred fire which had been brought by fugitives from Troy. In ancient Rome when the fire in the Temple of Vesta became extinguished, it was rekindled by the rubbing of a piece of wood upon another until fire was obtained. This was carried into the temple by the Vestal Virgin and the sacred fire was rekindled. The fire produced in this manner, for some reason, was considered holy. The early peoples displayed many lamps on feast-days and an example of extravagance in this respect is an occasion when King Constantine commanded that the entire city of Constantinople be illuminated by wax-candles on Christmas Eve. Candelabra, of the form of the branching tree, were commonly in use in the Roman temples. The ceremonial use of light in the Christian church evolved both from adaptations of pagan customs and of the natural symbolisms of fire and light. However, these acquired a deeper meaning in Christianity than in early times because they were primarily visible representations or manifestations of the divine presence. The Bible contains many references to the importance and symbolisms of light and fire. According to the First Book of Moses, the achievement of the Creator immediately following the creation of "the heavens and the earth" was the creation of light. The word "light" is the forty-sixth word in Genesis. Christ is "the true light" and Christians are "children of light" in war against the evil "powers of darkness." When St. Paul was converted "there shined about him a great light from heaven." The impressiveness and symbolism of fire and light are testified to in many biblical expressions. Christ stands "in the midst of seven candle-sticks" with "his eyes as a flame of fire." When the Holy Ghost appeared before the apostles "there appeared unto them cloven tongues of fire." When St. Paul was preaching the gospel of Christ at Alexandria "there were many lights" suggesting a festive illumination. According to the Bible, the perpetual fire which came originally from heaven was to be kept burning on the altar. It was holy and those whose duty it was to keep it burning were guilty of a grave offense if they allowed it to be extinguished. If human hands were permitted to kindle it, punishment was meted out. The two sons of Aaron who "offered strange fire before the Lord" were devoured by "fire from the Lord." The seven-branched candlestick was lighted eternally and these burning light-sources were necessary accompaniments of worship. The countless ceremonial uses of fire and light which had evolved in the past centuries were bound to influence the rites and customs of the Christian church. The festive illumination of pagan temples in honor of gods was carried over into the Christian era. The Christmas tree of to-day is incomplete without its many lights. Its illumination is a homage of light to the source of light. The celebration of Easter in the Church of the Holy Sepulchre in Jerusalem is a typical example of fire-worship retained from ancient times. At the climax of the services comes the descent of the Holy Fire. The central candelabra suddenly becomes ablaze and the worshipers, each of whom carries a wax taper, light their candles therefrom and rush through the streets. The fire is considered to be of divine origin and is a symbol of resurrection. The custom is similar in meaning to the light which in older times was maintained before gods. During the first two or three centuries of the Christian era the ceremonial use of light does not appear to have been very extensive. Writings of the period contain statements which appear to ridicule this use to some extent. For example, one writer of the second century states that "On days of rejoicing ... we do not encroach upon daylight with lamps." Another, in the fourth century, refers with sarcasm to the "heathen practice" in this manner: "They kindle lights as though to one who is in darkness. Can he be thought sane who offers the light of lamps and candles to the Author and Giver of all light?" That candles were lighted in cemeteries is evidenced by an edict which forbade their use during the day. Lamps of the early centuries of the Christian era have been found in the catacombs of Rome which are thought to have been ceremonial lamps, for they were not buried with the dead. They were found only in niches in the walls. During these same centuries elaborate candelabra containing hundreds of candles were kept burning before the tombs of saints. Notwithstanding the doubt that exists as to the extent of ceremonial lighting in the early centuries of the Christian era, it is certain that by the beginning of the fifth century the ceremonial use of light in the Christian church had become very extensive and firmly established. That this is true and that there were still some objections is indicated by many controversies. Some thought that lamps before tombs were ensigns of idolatry and others felt that no harm was done if religious people thus tried to honor martyrs and saints. Some early writings convey the idea that the ritualistic use of lights in the church arose from the retention of lights necessary at nocturnal services after the hours of worship had been changed to daytime. Passing beyond the early controversial period, the ceremonial use of light is everywhere in evidence at ordinary church services. On special occasions such as funerals, baptisms, and marriages, elaborate altar-lighting was customary. The gorgeous candelabra and the eternal lamp are noted in many writings. Early in the fifth century the pope ordered that candles be blessed and provided rituals for this ceremony. Shortly after this the Feast of Purification of the Virgin was inaugurated and it became known as Candlemas because on this day the candles for the entire year were blessed. However, it appears that the blessing of candles was not carried out in all churches. Altar lights were not generally used until the thirteenth century. They were originally the seven candles carried by church officials and placed near the altar. The custom of placing lighted lamps before the tombs of martyrs was gradually extended to the placing of such lamps before various objects of a sacred or divine relation. Finally certain light-sources themselves became objects of worship and were surrounded by other lamps, and the symbolisms of light grew apace. A bishop in the sixth century heralded the triple offering to God represented by the burning wax-candle. He pointed out that the rush-wick developed from pure water; that the wax was the product of virgin bees; and that the flame was sent from heaven. Each of these, he was certain, was an offering acceptable to God. Wax-candles became associated chiefly with religious ceremonies. The wax later became symbolic of the Blessed Virgin and of the body of Christ. The wick was symbolical of Christ's soul, the flame represented his divine character, and the burning candle thus became symbolical of his death. The lamp, lantern, and taper are frequently symbols of piety, heavenly wisdom, or spiritual light. Fire and flames are emblems of zeal and fervor or of the sufferings of martyrdom and the flaming heart symbolizes fervent piety and spiritual or divine love. By the time the Middle Ages were reached the ceremonial uses of light became very complex, but for the Roman Catholic Church they may be divided into three general groups: (1) They were symbolical of God's presence or of the effect of his presence; of Christ or of "the children of light"; or of joy and content at festivals. (2) They may be offered in fulfillment of a religious vow; that is, as an act of worship. (3) They may possess certain divine power because of their being blessed by the church, and therefore may be helpful to soul and body. The three conceptions are indicated in the prayers offered at the blessing of the candles on Candlemas as follows: (1) "O holy Lord ... who ... by thy command didst cause this liquid to come by the labor of bees to the perfection of wax, ... we beseech thee ... to bless and sanctify these candles for the use of men, and the health of bodies and souls...." (2) "...these candles, which we thy servants desire to carry lighted to magnify thy name; that by offering them to thee, being worthily inflamed with the holy fire of thy most sweet charity, we may deserve...." (3) "O Lord Jesus Christ, the true light, ... mercifully grant, that as these lights enkindled with visible fire dispel nocturnal darkness, so our hearts illuminated by visible fire," etc. In general, the ceremonial uses of lights in this church were originated as a forceful representation of Christ and of salvation. On the eve of Easter a new fire, emblematic of the arisen Christ, is kindled, and all candles throughout the year are lighted from this. During the service of Holy Week thirteen lighted candles are placed before the altar and as the penitential songs are sung they are extinguished one by one. When but one remains burning it is carried behind the altar, thus symbolizing the last days of Christ on earth. It is said that this ceremony has been traced to the eighth century. On Easter Eve, after the new fire is lighted and blessed, certain ceremonies of light symbolize the resurrection of Christ. From this new fire three candles are lighted and from these the Paschal Candle. The origin of the latter is uncertain, but it symbolizes a victorious Christ. From it all the ceremonial lights of the church are lighted and they thereby are emblematic of the presence of the light of Christ. Many interesting ceremonial uses may be traced out, but space permits a glimpse of only a few. At baptismal services the paschal candle is dipped into the water so that the latter will be effective as a regenerative element. The baptized child is reborn as a child of light. Lighted candles are placed in the hands of the baptized persons or of their god-parents. Those about to take vows carry lights before the church official and the same idea is attached to the custom of carrying or of holding lights on other occasions such as weddings and first communion. Lights are placed around the bodies of the dead and are carried at the funeral. They not only protect the dead from the powers of darkness but they symbolize the dead as still living in the light of Christ. The use of lighted candles around bodies of the dead still survives to some extent among Protestants, but their significance has been lost sight of. Even in the eighteenth century funerals in England were accompanied by lighted tapers, but the carrying of lights in other processions appears to have ceased with the Reformation. In some parts of Scotland it is still the custom to place two lighted candles on a table beside a corpse on the day of the funeral. With the importance of light in the ritual of the church it is not surprising that the extinction of lights is a part of the ceremony of excommunication. Such a ceremony is described in an early writing thus: "Twelve priests should stand about the bishop, holding in their hands lighted torches, which at the conclusion of the anathema or excommunication they should cast down and trample under foot." When the excommunicant is reinstated, a lighted candle is placed in his hands as a symbol of reconciliation. These and many other ceremonial uses of light have been and are practised, but they are not always mandatory. Furthermore, the customs have varied from time to time, but the few which have been touched upon illustrate the impressive part that light has played in religious services. During the Reformation the ceremonial use of lights was greatly altered and was abolished in the Protestant churches as a relic of superstition and papal authority. In the Lutheran churches ceremonial lights were largely retained, in the Church of England they have been subjected to many changes largely through the edicts of the rulers. In the latter church many controversies were waged over ceremonial lights and their use has been among the indictments of a number of officials of the church in impeachment cases before the House of Commons. Many uses of light in religious ceremonies were revived in cathedrals after the Restoration and they became wide-spread in England in the nineteenth century. As late as 1889 the Archbishop of Canterbury ruled that certain ceremonial candles were lawful according to the Prayer-Book of Edward VI, but the whole question was left open and unsettled. These byways of artificial light are complex and fascinating because their study leads into many channels and far into the obscurity of the childhood of the human race. A glimpse of them is important in a survey of the influence of artificial light upon the progress of civilization because in these usages the innate and acquired impressiveness of light is encountered. Although many ceremonial uses of light remain, it is doubtful if their significance and especially their origin are appreciated by most persons. Nevertheless, no more interesting phase of artificial light is encountered than this, which reaches to the foundation of civilization. V OIL-LAMPS OF THE NINETEENTH CENTURY It will be noted that the light-sources throughout the early ages were flames, the result of burning material. This principle of light-production has persisted until the present time, but in the latter part of the nineteenth century certain departures revolutionized artificial lighting. However, it is not the intention to enter the modern period in this chapter except in following the progress of the oil-lamp through its period of scientific development. The oil-lamp and the candle were the mainstays of artificial lighting throughout many centuries. The fats and waxes which these light-sources burned were many but in the later centuries they were chiefly tallow, sperm-oil, spermaceti, lard-oil, olive-oil, colza-oil, bees-wax and vegetable waxes. Those fuels which are not liquid are melted to liquid form by the heat of the flame before they are actually consumed. The candle is of the latter type and despite its present lowly place and its primitive character, it is really an ingenious device. Its fuel remains conveniently solid so that it is readily shipped and stored; there is nothing to spill or to break beyond easy repair; but when it is lighted the heat of its flame melts the solid fuel and thus it becomes an "oil-lamp." Animal and vegetable oils were mainly used until the middle of the nineteenth century, when petroleum was produced in sufficient quantities to introduce mineral oils. This marked the beginning of an era of developments in oil-lamps, but these were generally the natural offspring of early developments by Ami Argand. Before man discovered that nature had stored a tremendous supply of mineral oil in the earth he was obliged to hunt broadcast for fats and waxes to supply him with artificial light. He also was obliged to endure unpleasant odors from the crude fuels and in early experiments with fats and waxes the odor was carefully noted as an important factor. Tallow was a by-product of the kitchen or of the butcher. Stearine, a constituent of tallow, is a compound of glyceryl and stearic acid. It is obtained by breaking up chemically the glycerides of animal fats and separating the fatty acids from glycerin. Fats are glycerides; that is, combinations of oleic, palmetic, and stearic acids. Inasmuch as the former is liquid at ordinary temperatures and the others are solid, it follows that the consistency or solidity of fats depend upon the relative proportions of the three constituents. The sperm-whale, which lives in the warmer parts of all the oceans, has been hunted relentlessly for fuels for artificial lighting. In its head cavities sperm-oil in liquid form is found with the white waxy substance known as spermaceti. Colza-oil is yielded by rape-seed and olive-oil is extracted from ripe olives. The waxes are combinations of allied acids with bases somewhat related to glycerin but of complex composition. Fats and waxes are more or less related, but to distinguish them carefully would lead far afield into the complexities of organic chemistry. All these animal and vegetable products which were used as fuels for light-sources are rich in carbon, which accounts for the light-value of their flames. The brightness of such a flame is due to incandescent carbon particles, but this phase of light-production is discussed in another chapter. These oils, fats, and waxes are composed by weight of about 75 to 80 per cent. carbon; 10 to 15 per cent. hydrogen; and 5 to 10 per cent. oxygen. Until the middle of the eighteenth century the oil-lamps were shallow vessels filled with animal or vegetable oil and from these reservoirs short wicks projected. The flame was feeble and smoky and the odors were sometimes very repugnant. Viewing such light-sources from the present age in which light is plentiful, convenient, and free from the great disadvantages of these early oil-lamps, it is difficult to imagine the possibility of the present civilization emerging from that period without being accompanied by progress in light-production. The improvements made in the eighteenth century paved the way for greater progress in the following century. This is the case throughout the ages, but there are special reasons for the tremendous impetus which light-production has experienced in the past half-century. These are the acquirement of scientific knowledge from systematic research and the application of this knowledge by organized development. The first and most notable improvement in the oil-lamp was made by Argand in 1784. Our nation was just organizing after its successful struggle for independence at the time when the production of light as a science was born. Argand produced the tubular wick and contributed the greatest improvement by being the first to perform the apparently simple act of placing a glass chimney upon the lamp. His burner consisted of two concentric metal tubes between which the wick was located. The inner tube was open, so that air could reach the inner surface of the wick as well as the outer surface. The lamp chimney not only protected the flame from drafts but also improved combustion by increasing the supply of air. It rested upon a perforated flange below the burner. If the glass chimney of a modern kerosene lamp be lifted, it will be noted that the flame flickers and smokes and that it becomes steady and smokeless when the chimney is replaced. The advantages of such a chimney are obvious now, but Argand for his achievements is entitled to a place among the great men who have borne the torch of civilization. He took the first step toward adequate artificial light and opened a new era in lighting. The various improvements of the oil-lamp achieved by Argand combined to effect complete combustion, with the result that a steady, smokeless lamp of considerable luminous intensity was for the first time available. Many developments followed, among which was a combination of reservoir and gravity feed which maintained the oil at a constant level. In later lamps, upon the adoption of mineral oil, this was found unnecessary, perhaps owing to the construction of the wick and to the physical characteristics of the oil which favored capillary action in the wick. However, the height of the oil in the reservoir of modern oil-lamps makes some difference in the amount of light emitted. The Carcel lamp, which appeared in 1800, consisted of a double piston operated by clockwork. This forced the oil through a tube to the burner. Franchot invented the moderator lamp in 1836, which, because of its simplicity and efficiency soon superseded many other lamps designed for burning animal and vegetable oils. The chief feature of the moderator lamp is a spiral spring which forces the oil upward through a vertical tube to the burner. These are still used to some extent in France, but owing to the fact that "mechanical" lamps eventually were very generally replaced by more simple ones, it does not appear necessary to describe these complex mechanisms in detail. When coal is distilled at moderate temperatures, volatile liquids are obtained. These hydrocarbons, being inflammable, naturally attracted attention when first known, and in 1781 their use as fuel for lamps was suggested. However, it was not until 1820 that the light oils obtained by distilling coal-tar, a by-product of the coal-gas industry which was then in its early stage of development, were burned to some extent in the Holliday lamp. In this lamp the oil is contained in a reservoir from the bottom of which a fine metal tube carries the oil down to a rose-burner. The oil is heated by the flame and the vaporized mineral oil which escapes through small orifices is burned. This type of lamp has undergone many physical changes, but its principle survives to the present time in the gasolene and kerosene burners hanging on a pole by the side of the street-peddler's stand. Although petroleum products were not used to any appreciable extent for illuminating-purposes until after the middle of the nineteenth century, mineral oil is mentioned by Herodotus and other early writers. In 1847 petroleum was discovered in a coal-mine in England, but the supply failed in a short time. However, the discoverer, James Young, had found that this oil was valuable as a lubricant and upon the failure of this source he began experiments in distilling oil from shale found in coal deposits. These were destined to form the corner-stone of the oil industry in Scotland. In 1850 he began producing petroleum in this manner, but it was not seriously considered for illuminating-purposes. However, in Germany about this time lamps were developed for burning the lighter distillates and these were introduced into several countries. But the price of these lighter oils was so great that little progress was made until, in 1859, Col. E. L. Drake discovered oil in Pennsylvania. By studying the geological formations and concluding that oil should be obtained by boring, Drake gave to the world a means of obtaining petroleum, and in quantities which were destined to reduce the price of mineral oil to a level undreamed of theretofore. To his imagination, which saw vast reservoirs of oil in the depths of the earth, the world owes a great debt. Lamps were imported from Germany to all parts of the civilized world and the kerosene lamp became the prevailing light-source. Hundreds of American patents were allowed for oil-lamps and their improvements in the next decade. [Illustration: LAMPS OF A CENTURY OR TWO AGO] [Illustration: ELABORATE FIXTURES OF THE AGE OF CANDLES] The crude petroleum, of course, is not fit for illuminating purposes, but it contains components which are satisfactory. The various components are sorted out by fractional distillation and the oil for burning in lamps is selected according to its volatility, viscosity, stability, etc. It must not be so volatile as to have a dangerously low flashing-point, nor so stable as to hinder its burning well. In this fractional distillation a vast variety of products are now obtained. Gasolene is among the lighter products, with a density of about 0.65; kerosene has a density of about 0.80; the lubricating-oils from 0.85 to 0.95; and there are many solids such as vaseline and paraffin which are widely used for many purposes. This process of refining oils is now the source of paraffin for making candles, in which it is usually mixed with substances like stearin in order to raise its melting-point. Crude petroleum possesses a very repugnant odor; it varies in color from yellow to black; and its specific gravity ranges from about 0.80 to 1.00, but commonly is between 0.80 and 0.90. Its chemical constitution is chiefly of carbon and hydrogen, in the approximate ratio of about six to one respectively. It is a mixture of paraffin hydrocarbons having the general formula of C_{n}H_{2n+2} and the individual members of this series vary from CH_{4} (methane) to C_{15}H_{32} (pentadecane), although the solid hydrocarbons are still more complex. Petroleum is found in many countries and the United States is particularly blessed with great stores of it. The ordinary lamp consisting of a wick which draws up the mineral oil and feeds it to a flame is efficient and fairly free from danger. It requires care and may cause disaster if it is upset, but it has been blamed unjustly in many accidents. A disadvantage of the kerosene lamp over electric lighting, for example, is the relatively greater possibility of accidents through the carelessness of the user. This point is brought out in statistics of fire-insurance companies, which show that the fires caused by kerosene lamps are much more numerous than those from other methods of lighting. If in a modern lamp of proper construction a close-fitting wick is used and the lamp is extinguished by turning down and blowing across the chimney, there is little danger in its use excepting accidental breakage or overturning. In oil-lamps at the present time mineral oils are used which possess flashing-points above 75°F. The highly volatile components of petroleum are dangerous because they form very explosive mixtures with air at ordinary temperatures. A mineral oil like kerosene, to be used with safety in lamps, should not be too volatile. It is preferable that an inflammable vapor should not be given off at temperatures under 120°F. The oil must be of such physical characteristics as to be drawn up to the burner by capillarity from the reservoir which is situated below. It is volatilized by the heat of the flame into a mixture of hydrogen and hydrocarbon gases and these are consumed under the heat of the process of consumption by the oxygen in the air. The resulting products of this combustion, if it is complete, are carbon dioxide and water-vapor. For each candle-power of light per hour about 0.24 cubic foot of carbon dioxide and 0.18 cubic foot of water-vapor are formed by a modern oil-lamp. That an open flame devours something from the air is easily demonstrated by enclosing it in an air-tight space. The flame gradually becomes feeble and smoky and finally goes out. It will be noted that a burning lamp will vitiate the atmosphere of a closed room by consuming the oxygen and returning in its place carbon dioxide. This is similar to the vitiation of the atmosphere by breathing persons and tests indicate that for each two candle-power emitted by a kerosene flame the vitiation is equal to that produced by one adult person. Inasmuch as oil-lamps are ordinarily of 10 to 20 candle-power, it is seen that one lamp will consume as much oxygen as several persons. In order that oil-lamps may produce a brilliant light free from smoke, combustion must be complete. The correct quantity of oil must be fed to the burner and it must be properly vaporized by heat. If insufficient oil is fed, the intensity of the light is diminished and if too much is available at the burner, smoke and other products of incomplete combustion will be emitted. The wick is an important factor, for, through capillarity, it feeds oil forcefully to the burner against the action of gravity. This action of a wick is commonly looked upon with indifference but in reality it is caused by an interesting and really wonderful phenomenon. Wicks are usually made of high-grade cotton fiber loosely spun into coarse threads and these are woven into a loose plait. The wick must be dry before being inserted into the burner; and it is desirable that it be considerably longer than is necessary merely to reach the bottom of the reservoir. A flame burning in the open will smoke because insufficient oxygen is brought in contact with it. The injurious products of this incomplete combustion are carbon monoxide and oil vapors, which are a menace to health. To supply the necessary amount of oxygen (air) to the flame, a forced draft is produced. Chimneys are simple means of accomplishing this, and this is their function whether on oil-lamps or factories. Other means of forced draft have been used, such as small fans or compressed air. In the railway locomotive the short smoke-stack is insufficient for supplying large quantities of air to the fire-box so the exhausted steam is allowed to escape into the stack. With each noisy puff of smoke a quantity of air is forcibly drawn into the fire-box through the burning fuel. In the modern oil-lamp the rush of air due to the "pull" of the chimney is broken and the air is diffused by the wire gauze or holes at the base of the burner. These metal parts, being hot, also serve to warm the oil before it reaches the burning end of the wick, thus serving to aid vaporization and combustion. The consumption of oil per candle-power per hour varies considerably with the kind of lamp and with the character of the oil. The average consumption of oil-lamps burning a mineral oil of about 0.80 specific gravity and a rather high flashing-point is about 50 to 60 grams of oil per candle-power per hour for well-designed flame-lamps. Kerosene weighs about 6.6 pounds per gallon; therefore, about 800 candle-power hours per gallon are obtained from modern lamps employing wicks. Kerosene lamps are usually of 10 to 20 candle-power, although they are made up to 100 candle-power. These luminous intensities refer to the maximum horizontal candle-power. The best practice now deals with the total light output, which is expressed in lumens, and on this basis a consumption of one gallon of kerosene per hour would yield about 8000 lumens. Oil-lamps have been devised in which the oil is burned as a spray ejected by air-pressure. These burn with a large flame; however, a serious feature is the escape of considerable oil which is not burned. These lamps are used in industrial lighting, especially outdoors, and possess the advantage of consuming low-grade oils. They produce about 700 to 800 candle-power hours per gallon of oil. Lamps of this type of the larger sizes burn with vertical flames two or three feet high. The oil is heated as it approaches the nozzle and is fairly well vaporized on emerging into the air. The names of Lucigen, Wells, Doty, and others are associated with this type of lamp or torch, which is a step in the direction of air-gas lighting. During the latter part of the nineteenth century numerous developments were made which paralleled the progress in gas-lighting. Experiments were conducted which bordered closely upon the next epochal event in light-production--the appearance of the gas mantle. One of these was the use of platinum gauze by Kitson. He produced an apparatus similar to the oil-spray lamp, on a small and more delicate scale. The hot blue flame was not very luminous and he attempted to obtain light by heating a mantle of fine platinum gauze. Although these mantles emitted a brilliant light for a few hours, their light-emissivity was destroyed by carbonization. After the appearance of the Welsbach mantle, Kitson's lamp and others met with success by utilizing it. From this point, attention was centered upon the new wonder, which is discussed in a later chapter after certain scientific principles in light-production have been discussed. The kerosene or mineral-oil lamp was a boon to lighting in the nineteenth century and even to-day it is a blessing in many homes, especially in villages, in the country, and in the remote districts of civilization. Its extensive use at the present time is shown by the fact that about eight million lamp-chimneys are now being manufactured yearly in this country. It is convenient and safe when carelessness is avoided, and is fairly free from odor. Its vitiation of the atmosphere may be counteracted by proper ventilation and there remains only the disadvantage of keeping it in order and of accidental breakage and overturning. The kerosene lantern is widely used to-day, but the danger due to accident is ever-present. The consequences of such accidents are often serious and are exemplified in the terrible conflagration in Chicago in 1871, when Mrs. O'Leary's cow kicked over a lantern and started a fire which burned the city. Modern developments in lighting are gradually encroaching upon the territory in which the oil-lamp has reigned supreme for many years. Acetylene plants were introduced to a considerable extent some time ago and to-day the self-contained home-lighting electric plant is being installed in large numbers in the country homes of the land. VI EARLY GAS-LIGHTING Owing to the fact that the smoky, flickering oil-lamp persisted throughout the centuries and until the magic touch of Argand in the latter part of the eighteenth century transformed it into a commendable light-source, the reader is prepared to suppose that gas-lighting is of recent origin. Apparently William Murdock in England was the first to install pipes for the conveyance of gas for lighting purposes. In an article in the "Philosophical Transactions of the Royal Society of London" dated February 25, 1808, in which he gives an account of the first industrial gas-lighting, he states: It is now nearly sixteen years, since, in a course of experiments I was making at Redruth in Cornwall, upon the quantities and qualities of the gases produced by distillation from different mineral and vegetable substances, I was induced by some observation I had previously made upon the burning of coal, to try the combustible property of the gases produced from it.... Inasmuch as he is credited with having lighted his home by means of piped gas, this experimental installation may be considered to have been made in 1792. In his first trial he burned the gas at the open ends of the pipes; but finding this wasteful, he closed the ends and in each bored three small holes from which the gas-flames diverged. It is said that he once used his wife's thimble in an emergency to close the end of the pipe; and, the thimble being much worn and consequently containing a number of small holes, tiny gas-jets emerged from the holes. This incident is said to have led to the use of small holes in his burners. He also lighted a street lamp and had bladders filled with gas "to carry at night, with which, and his little steam carriage running on the road, he used to astonish the people." Apparently unknown to Murdock, previous observations had been made as to the inflammability of gas from coal. Long before this Dr. Clayton described some observations on coal-gas, which he called "the spirit of coals." He filled bladders with this gas and kept them for some time. Upon his pricking one of them with a pin and applying a candle, the gas burned at the hole. Thus Clayton had a portable gas-light. He was led to experiment with distillation of coal from some experiences with gas from a natural coal bed, and he thus describes his initial laboratory experiment: I got some coal, and distilled it in a retort in an open fire. At first there came over only phlegm, afterwards a black _oil_, and then likewise, a _spirit_ arose which I could no ways condense; but it forced my lute and broke my glasses. Once when it had forced my lute, coming close thereto, in order to try to repair it, I observed that the spirit which issued out _caught fire_ at the _flame_ of the _candle_, and continued burning with violence as it _issued out_ in a _stream_, which I blew out, and lighted again alternately several times. He then turned his attention to saving some of the gas and hit upon the use of bladders. He was surprised at the amount of gas which was obtained from a small amount of coal; for, as he stated, "the spirit continued to rise for several hours, and filled the bladders almost as fast as a man could have blown them with his mouth; and yet the quantity of coals distilled was inconsiderable." Although this account appeared in the Transactions of the Royal Society in 1739, there is strong evidence that Dr. Clayton had written it many years before, at least prior to 1691. But before entering further into the early history of gas-lighting, it is interesting to inquire into the knowledge possessed in the seventeenth century pertaining to natural and artificial gas. Doubtless there are isolated instances throughout history of encounters with natural gas. Surely observant persons of bygone ages have noted a small flame emanating from the end of a stick whose other end was burning in a bonfire or in the fireplace. This is a gas-plant on a small scale; for the gas is formed at the burning end of the wooden stick and is conducted through its hollow center to the cold end, where it will burn if lighted. If a piece of paper be rolled into the form of a tube and inclined somewhat from a horizontal position, inflammable gas will emanate from the upper end if the lower end is burning. By applying a match near the upper end, we can ignite this jet of gas. However, it is certain that little was known of gas for illuminating purposes before the eighteenth century. The literature of an ancient nation is often referred to as revealing the civilization of the period. Surely the scientific literature which deals with concrete facts is an exact indicator of the technical knowledge of a period! That little was known of natural gas and doubtless of artificial gas in the seventeenth century is shown by a brief report entitled "A Well and Earth in Lancashire taking Fire at a Candle," by Tho. Shirley in the Transactions of the Royal Society in 1667. Much of the quaint charm of the original is lost by inability to present the text in its original form, but it is reproduced as closely as practicable. The report was as follows: About the latter End of _Feb._ 1659, returning from a Journey to my House in Wigan, I was entertained with the Relation of an odd Spring situated in one Mr. _Hawkley's_ Ground (if I mistake not) about a Mile from the Town, in that Road which leads to _Warrington_ and _Chester_: The People of this Town did confidently affirm, That the Water of this Spring did burn like Oil. When we came to the said Spring (being 5 or 6 in Company together) and applied a lighted Candle to the Surface of the Water; there was 'tis true, a large Flame suddenly produced, which burnt the Foot of a Tree, growing on the Top of a neighbouring Bank, the Water of which Spring filled a Ditch that was there, and covered the Burning-place; I applied the lighted Candle to divers Parts of the Water contained in the said Ditch, and found, as I expected, that upon the Touch of the Candle and the Water the Flame was extinct. Again, having taken up a Dish full of water at the flaming Place, and held the lighted Candle to it, it went out. Yet I observed that the Water, at the Burning-place, did boil, and heave, like Water in a Pot upon the Fire, tho' by putting my Hand into it, I could not perceive it so much as warm. This Boiling I conceived to proceed from the Eruption of some bituminous or sulphureous Fumes; considering this Place was not above 30 or 40 Yards distant from the Mouth of a Coal-Pit there: And indeed _Wigan_, _Ashton_, and the whole Country, for many Miles compass, is underlaid with Coal. Then, applying my Hand to the Surface of the Burning-place of the Water, I found a strong Breath, as it were a Wind, to bear against my Hand. When the Water was drained away, I applied the Candle to the Surface of the dry Earth, at the same Point where the Water burned before; the Fumes took fire, and burned very bright and vigorous. The Cone of the Flame ascended a Foot and a half from the Superficies of the Earth; and the Basis of it was of the Compass of a Man's Hat about the Brims. I then caused a Bucket full of Water to be pour'd on the Fire, by which it was presently quenched. I did not perceive the Flame to be discoloured like that of sulphurous Bodies, nor to have any manifest Scent with it. The Fumes, when they broke out of the Earth, and press'd against my Hand, were not, to my best Remembrance, at all hot. Turning again to Dr. Clayton's experiments, we see that he pointed out striking and valuable properties of coal-gas but apparently gave no attention to its useful purposes. Furthermore, his account appears to have attracted no particular notice at the time of its publication in 1739. Dr. Richard Watson in 1767 described the results of experiments which he had been making with the products arising from the distillation of coal. In his process he permitted the gas to ascend through curved tubes, and he particularly noted "its great inflammability as well as elasticity." He also observed that "it retained the former property after it had passed through a great quantity of water." His published account dealt with a variety of facts and computations pertaining to the quantities of coke, tar, etc., produced from different kinds of coal and was a scientific work of value, but apparently the usefulness of the property of inflammability of coal-gas did not occur to him. It is usually the habit of the scientific explorer of nature to return from excursions into her unfrequented recesses with new knowledge, to place it upon exhibition, and to return for more. The inventor passes by and sees applications for some of these scientific trophies which are productive of momentous consequences to mankind. Sir Humphrey Davy described his primitive arc-lamp three quarters of a century before Brush developed an arc-lamp for practical purposes. Maxwell and Hertz respectively predicted and produced electromagnetic waves long before Marconi applied this knowledge and developed "wireless" telegraphy. In a similar manner scientific accounts of the production and properties of coal-gas antedated by many years the initial applications made by Murdock to illuminating purposes. Up to the beginning of the nineteenth century the civilized world had only a faint glimpse of the illuminating property of gas, but practicable gas-lighting was destined soon to be an epochal event in the progress of lighting. The dawn of modern science was coincident with the dawn of a luminous era. At Soho foundry in 1798 Murdock constructed an apparatus which enabled him to exhibit his lighting-plan on a larger scale and to experiment on purifying and burning the gas so as to eliminate odor and smoke. Soho was an unique institution described as a place to which men of genius were invited and resorted from every civilized country, to exercise and to display their talents. The perfection of the manufacturing arts was the great and constant aim of its liberal and enlightened proprietors, Messrs. Boulton and Watt; and whoever resided there was surrounded by a circle of scientific, ingenious, and skilful men, at all times ready to carry into effect the inventions of each other. The Treaty of Amiens, which gave to England the peace she was sorely in need of, afforded Murdock an opportunity in 1802 favorable for making a public display of gas-lighting. The illumination of the Soho works on this occasion is described as "one of extraordinary splendour." The fronts of the extensive range of buildings were ornamented with a large number of devices which displayed the variety of forms of gas-lights. At that time this was a luminous spectacle of great novelty and the populace came from far and wide "to gaze at, and to admire, this wonderful display of the combined effects of science and art." Naturally, Murdock had many difficulties to overcome in these early days, but he possessed skill and perseverance. His first retorts for distilling coal were similar to the common glass retort of the chemist. Next he tried cast-iron cylinders placed perpendicularly in a common furnace, and in each were put about fifteen pounds of coal. In 1804 he constructed them with doors at each end, for feeding coal and extracting coke respectively, but these were found inconvenient. In his first lighting installation in the factory of Phillips and Lee in 1805 he used a large retort of the form of a bucket with a cover on it. Inside he installed a loose cage of grating to hold the coal. When carbonization was complete the coke could be removed as a whole by extracting this cage. This retort had a capacity of fifteen hundred pounds of coal. He labored with mechanical details, varied the size and shape of the retorts, and experimented with different temperatures, with the result that he laid a solid foundation for coal-gas lighting. For his achievements he is entitled to an honorable place among the torch-bearers of civilization. The epochal feature of the development of gas-lighting is that here was a possibility for the first time of providing lighting as a public utility. In the early years of the nineteenth century the foundation was laid for the great public-utility organizations of the present time. Furthermore, gas-lighting was an improvement over candles and oil-lamps from the standpoints of convenience, safety, and cost. The latter points are emphasized by Murdock in his paper presented before the Royal Society in 1808, in which he describes the first industrial installation of gas-lighting. He used two types of burners, the Argand and the cockspur. The former resembled the Argand lamp in some respects and the latter was a three-flame burner suggesting a fleur-de-lis. In this installation there were 271 Argand burners and 636 cockspurs. Each of the former "gave a light equal to that of four candles; and each of the latter, a light equal to two and a quarter of the same candles; making therefore the total of the gas light a little more than 2500 candles." The candle to which he refers was a mold candle "of six in the pound" and its light was considered a standard of luminous intensity when it was consuming tallow at the rate of 0.4 oz. (175 grains) per hour. Thus the candle became very early a standard light-source and has persisted as such (with certain variations in the specifications) until the present time. However, during recent years other standard light-sources have been devised. According to Murdock, the yearly cost of gas-lighting in this initial case was 600 pounds sterling after allowing generously for interest on capital invested and depreciation of the apparatus. The cost of furnishing the same amount of light by means of candles he computed to be 2000 pounds sterling. This comparison was on the basis of an average of two hours of artificial lighting per day. On the basis of three hours of artificial lighting per day, the relative cost of gas-and candle-lighting was about one to five. Murdock was characteristically modest in discussing his achievements and his following statement should be read with the conditions of the year 1808 in mind: The peculiar softness and clearness of this light with its almost unvarying intensity, have brought it into great favour with the work people. And its being free from the inconvenience and danger, resulting from sparks and frequent snuffing of candles, is a circumstance of material importance, as tending to diminish the hazard of fire, to which cotton mills are known to be exposed. Although this installation in the mill of Phillips and Lee is the first one described by Murdock, in reality it is not the first industrial gas-lighting installation. During the development of gas apparatus at the Soho works and after his luminous display in 1802, he gradually extended gas-lighting to all the principal shops. However, this in a sense was experimental work. Others were applying their knowledge and ingenuity to the problem of making gas-lighting practicable, but Murdock has been aptly termed "the father of gas-lighting." Among the pioneers was Le Bon in France, Becher in Munich, and Winzler or Winsor, a German who was attracted to the possibilities of gas-lighting by an exhibition which Le Bon gave in Paris in 1802. Winsor learned that Le Bon had been granted a patent in Paris in 1799 for making an illuminating gas from wood and tried to obtain the rights for Germany. Being unsuccessful in this, he set about to learn the secrets of Le Bon's process, which he did, perhaps largely owing to an accumulation of information directly from the inventor during the negotiations. Winsor then turned to England as a fertile field for the exploitation of gas-lighting and after conducting experiments in London for some time he made plans to organize the National Heat and Light Co. Winsor was primarily a promoter, with little or no technical knowledge; for in his claims and advertisements he disregarded facts with a facility possessed only by the ignorant. He boasted of his inventions and discoveries in the most hyperbolical language, which was bound to provoke a controversy. Nevertheless, he was clever and in 1803 he publicly exhibited his plan of lighting by means of coal-gas at the Lyceum Theatre in London. He gave lectures accompanied by interesting and instructive experiments and in this manner attracted the public to his exhibition. All this time he was promoting his company, but his promoting instinct caused his representations to be extravagant and deceptive, which exposed him to the ridicule and suspicion of learned men. His attempt to obtain certain exclusive rights by Act of Parliament failed because of opposition of scientific men toward his claims and of the stand which Murdock justly made in self-protection. These years of controversy yield entertaining literature for those who choose to read it, but unfortunately space does not permit dwelling upon it. The investigations by committees of Parliament also afford amusing side-lights. Throughout all this Murdock appeared modest and conservative and had the support of reputable scientific men, but Winsor maintained extravagant claims. During one of these investigations Sir Humphrey Davy was examined by a committee from the House of Commons in 1809. He refuted Winsor's claims for a superior coke as a by-product and stated that the production of gas by the distillation of coal had been well known for thirty or forty years and the production of tar as long. He stated that it was the opinion of the Council of the Royal Society that Murdock was the first person to apply coal-gas to lighting in actual practice. As secretary of the Society, Sir Humphrey Davy stated that at the last session it had bestowed the Count Rumford medal upon Murdock for "his economical application of the gas light." Winsor proceeded to float his company without awaiting the Act of Parliament and in 1807 lighted a street in Pall Mall. Through the opposition which he aroused, and owing to the just claims of priority on the part of Murdock, the bill to incorporate the National Heat and Light Co. with a capital of 200,000 pounds sterling was thrown out. However, he succeeded in 1812 in receiving a charter very much modified in form, for the Chartered Gas Light and Coke Co. which was the forerunner of the present London Gas Light and Coke Co. The conditions imposed upon this company as presented in an early treatise on gas-lighting (by Accum in 1818) were as follows: The power and authorities granted to this corporate body are very restricted and moderate. The individuals composing it have no exclusive privilege; their charter does not prevent other persons from entering into competition with them. Their operations are confined to the metropolis, where they are bound to furnish not only a stronger and better light to such streets and parishes as chuse to be lighted with gas, but also at a cheaper price than shall be paid for lighting the said streets with oil in the usual manner. The corporation is not permitted to traffic in machinery for manufacturing or conveying the gas into private houses, their capital or joint stock is limited to £200,000, and his Majesty has the power of declaring the gas-light charter void if the company fail to fulfil the terms of it. The progress of this early company was slow at first, but with the appointment of Samuel Clegg as engineer in 1813 an era of technical developments began. New stations were built and many improvements were introduced. By improving the methods of purifying the gas a great advance was made. The utility of gas-lighting grew apace as the prejudices disappeared, but for a long time the stock of the company sold at a price far below par. About this time the first gas explosion took place and the members of the Royal Society set a precedent which has lived and thrived: they appointed a committee to make an inquiry. But apparently the inquiry was of some value, for it led "to some useful alterations and new modifications in its apparatus and machinery." Many improvements were being introduced during these years and one of them in 1816 increased the gaseous product from coal by distilling the tar which was obtained during the first distillation. In 1816 Clegg obtained a patent for a horizontal rotating retort; for an apparatus for purifying coal-gas with "cream of lime"; and for a rotative gas-meter. Before progressing too far, we must mention the early work of William Henry. In 1804 he described publicly a method of producing coal-gas. Besides making experiments on production and utilization of coal-gas for lighting, he devoted his knowledge of chemistry to the analysis of the gas. He also made analytical studies of the relative value of wood, peat, oil, wax, and different kinds of coal for the distillation of gas. His chemical analyses showed to a considerable extent the properties of carbureted hydrogen upon which illuminating value depended. The results of his work were published in various English journals between 1805 and 1825 and they contributed much to the advancement of gas-lighting. Although Clegg's original gas-meter was complicated and cumbersome, it proved to be a useful device. In fact, it appears to have been the most original and beneficial invention occasioned by early gas-lighting. Later Samuel Crosley greatly improved it, with the result that it was introduced to a considerable extent; but by no means was it universally adopted. Another improvement made by Clegg at this time was a device which maintained the pressure of gas approximately constant regardless of the pressure in the gasometer or tank. Clegg retired from the service of the gas company in 1817 after a record of accomplishments which glorifies his name in the annals of gas-lighting. Murdock is undoubtedly entitled to the distinction of having been the first person who applied gas-lighting to large private establishments, but Clegg overcame many difficulties and was the first to illuminate a whole town by this means. In London in 1817 over 300,000 cubic feet of coal-gas was being manufactured daily, an amount sufficient to operate 76,500 Argand burners yielding 6 candle-power each. Gas-lighting was now exciting great interest and was firmly established. Westminster Bridge was lighted by gas in 1813, and the streets of Westminster during the following year. Gas-lighting became popular in London by 1816 and in the course of the next few years it was adopted by the chief cities and towns in the United Kingdom and on the Continent. It found its way into the houses rather slowly at first, owing to apprehension of the attendant dangers, to the lack of purification of the gas, and to the indifferent service. It was not until the latter half of the nineteenth century that it was generally used in residences. The gas-burner first employed by Murdock received the name "cockspur" from the shape of the flame. This had an illuminating value equivalent to about one candle for each cubic foot of gas burned per hour. The next step was to flatten the welded end of the gas-pipe and to bore a series of holes in a line. From the shape of the flames this form of burner received the name "cockscomb." It was somewhat more efficient than the cockspur burner. The next obvious step was to slit the end of the pipe by means of a fine saw. From this slit the gas was burned as a sheet of flame called the "bats-wing." In 1820 Nielson made a burner which allowed two small jets to collide and thus form a flat flame. The efficiency of this "fish-tail" burner was somewhat higher than that of the earlier ones. Its flame was steadier because it was less influenced by drafts of air. In 1853 Frankland showed an Argand burner consisting of a metal ring containing a series of holes from which jets of gas issued. The glass chimney surrounded these, another chimney, extending somewhat lower, surrounded the whole, and a glass plate closed the bottom. The air to be fed to the gas-jets came downward between the two chimneys and was heated before it reached the burner. This increased the efficiency by reducing the amount of cooling at the burner by the air required for combustion. This improvement was in reality the forerunner of the regenerative lamps which were developed later. In 1854 Bowditch brought out a regenerative lamp and, owing to the excessive publicity which this lamp obtained, he is generally credited with the inception of the regenerative burner. This principle was adopted in several lamps which came into use later. They were all based upon the principle of heating both the gas and the air required for combustion prior to their reaching the burner. The burner is something like an inverted Argand arranged to produce a circular flame projecting downward with a central cusp. The air- and gas-passages are directly above the flame and are heated by it. In 1879 Friedrich Siemens brought out a lamp of this type which was adapted from a device originally designed for heating purposes, owing to the superior light which was produced. This was the best gas-lamp up to that time. Later, Wenham, Cromartie, and others patented lamps operating on this same principle. Murdock early modified the Argand burner to meet the requirements of burning gas and by using the chimney obtained better combustion and a steadier flame than from the open burners. He and others recognized that the temperature of the flame had a considerable effect upon the amount of light emitted and non-conducting material such as steatite was substituted for the metal, which cooled the flame by conducting heat from it. These were the early steps which led finally to the regenerative burner. The increasing efficiency of the various gas-burners is indicated by the following, which are approximately the candle-power based upon equal rates of consumption, namely, one cubic foot of gas per hour: Candle-power per cubic foot of gas per hour Fish-tail flames, depending upon size 0.6 to 2.5 Argand, depending upon improvements 2.9 to 3.5 Regenerative 7 to 10 It is seen that the possibilities of gas lighting were recognized in several countries, all of which contributed to its development. Some of the earlier accounts have been drawn chiefly from England, but these are intended merely to serve as examples of the difficulties encountered. Doubtless, similar controversies arose in other countries in which pioneers were also nursing gas-lighting to maturity. However, it is certain that much of the early progress of lighting of this character was fathered in England. Gas-lighting was destined to become a thriving industry, and is of such importance in lighting that another chapter is given its modern developments. VII THE SCIENCE OF LIGHT-PRODUCTION In previous chapters much of the historical development of artificial lighting has been presented and several subjects have been traced to the modern period which marks the beginning of an intensive attack by scientists upon the problems pertaining to the production of efficient and adequate light-sources. Many historical events remain to be touched upon in later chapters, but it is necessary at this point for the reader to become acquainted with certain general physical principles in order that he may read with greater interest some of the chapters which follow. It is seen that from a standpoint of artificial lighting, the "dark age" extended well into the nineteenth century. Oil-lamps and gas-lighting began to be seriously developed at the beginning of the last century, but the pioneers gave attention chiefly to mechanical details and somewhat to the chemistry of the fuels. It was not until the science of physics was applied to light-sources that rapid progress was made. All the light-sources used throughout the ages, and nearly all modern ones, radiate light by virtue of the incandescence of solids or of solid particles and it is an interesting fact that carbon is generally the solid which emits light. This is due to various physical characteristics of carbon, the chief one being its extremely high melting-point. However, most practicable light-sources of the past and present may be divided into two general classes: (1) Those in which solids or solid particles are heated by their own combustion, and (2) those in which the solids are heated by some other means. Some light-sources include both principles and some perhaps cannot be included under either principle without qualification. The luminous flames of burning material such as those of wood-splinters, candles, oil-lamps, and gas-jets, and the glowing embers of burning material appear in the first class; and incandescent gas-mantles, electric filaments, and arc-lamps to some extent are representative of the second class. Certain "flaming" arcs involve both principles, but the light of the firefly, phosphorescence, and incandescent gas in "vacuum" tubes cannot be included in this simplified classification. The status of these will become clear later. It has been seen that flames have been prominent sources of artificial light; and although of low luminous efficiency, they still have much to commend them from the standpoints of portability, convenience, and subdivision. The materials which have been burned for light, whether solid or liquid, are rich in carbon, and the solid particles of carbon by virtue of their incandescence are responsible for the brightness of a flame. A jet of pure hydrogen gas will burn very hot but with so low a brightness as to be barely visible. If solid particles are injected into the flame, much more light usually will be emitted. A gas-burner of the Bunsen type, in which complete combustion is obtained by mixing air in proper proportions with the gas, gives a hot flame which is of a pale blue color. Upon the closing of the orifice through which air is admitted, the flame becomes bright and smoky. The flame is now less hot, as indicated by the presence of smoke or carbon particles, and combustion is not complete. However, it is brighter because the solid particles of carbon in passing upward through the flame become heated to temperatures at which they glow and each becomes a miniature source of light. A close observer will notice that the flame from a match, a candle, or a gas-jet, is not uniformly bright. The reader may verify this by lighting a match and observing the flame. There is always a bluish or darker portion near the bottom. In this less luminous part the air is combining with the hydrogen of the hydrocarbon which is being vaporized and disintegrated. Even the flame of a candle or of a burning splinter is a miniature gas-plant, for the solid or liquid hydrocarbons are vaporized before being burned. Owing to the incoming colder air at this point, the flame is not hot enough for complete combustion. The unburned carbon particles rise in its draft and become heated to incandescence, thus accounting for the brighter portion. In cases of complete combustion they are eventually oxidized into carbon dioxide before they are able to escape. If a piece of metal be held in the flame, it immediately becomes covered with soot or carbon, because it has reduced the temperature below the point at which the chemical reaction--the uniting of carbon with oxygen--will continue. An ordinary flat gas-flame of the "bats-wing" type may vary in temperature in its central portion from 300°F. at the bottom to about 3000°F. at the top. The central portion lies between two hotter layers in which the vertical variation is not so great. The brightness of the upper portion is due to incandescent carbon formed in the lower part. When scientists learned by exploring flames that brightness was due to the radiation of light by incandescent solid matter, the way was open for many experiments. In the early days of gas-lighting investigations were made to determine the relation of illuminating value to the chemical constitution of the gas. The results combined with a knowledge of the necessity for solid carbon in the flame led to improvements in the gas for lighting purposes. Gas rich in hydrocarbons which in turn are rich in carbon is high in illuminating value. Heating-effect depends upon heat-units, so the rating of gas in calories or other heat-units per cubic foot is wholly satisfactory only for gas used for heating. The chemical constitution is a better indicator of illuminating value. As scientific knowledge increased, efforts were made to get solid matter into the flames of light-sources. Instead of confining efforts to the carbon content of the gas, solid materials were actually placed in the flame, and in this manner various incandescent burners were developed. A piece of lime placed in a hydrogen flame or that of a Bunsen burner is seen to become hot and to glow brilliantly. By producing a hotter flame by means of the blowpipe, in which hydrogen and oxygen are consumed, the piece of lime was raised to a higher temperature and a more intense light was obtained. In Paris there was a serious attempt at street-lighting by the use of buttons of zirconia heated in an oxygen-coal-gas flame, but it proved unsuccessful owing to the rapid deterioration of the buttons. This was the line of experimentation which led to the development of the lime-light. The incandescent burner was widely employed, and until the use of electricity became common the lime-light was the mainstay for the stage and for the projection of lantern slides. It is in use even to-day for some purposes. The origin of the phrase "in the lime-light" is obvious. The luminous intensity of the oxyhydrogen lime-light as used in practice was generally from 200 to 400 candle-power. The light decreases rapidly as the burner is used, if a new surface of lime is not presented to the flame from time to time. At the high temperatures the lime is somewhat volatile and the surface seems to change in radiating power. Zirconium oxide has been found to serve better than lime. Improvements were made in gas-burners in order to obtain hotter flames into which solid matter could be introduced to obtain bright light. Many materials were used, but obviously they were limited to those of a fairly high melting-point. Lime, magnesia, zirconia, and similar oxides were used successfully. If the reader would care to try an experiment in verification of this simple principle, let him take a piece of magnesium ribbon such as is used in lighting for photography and ignite it in a Bunsen flame. If it is held carefully while burning, a ribbon of ash (magnesia) will be obtained intact. Placing this in the faintly luminous flame, he will be surprised at the brilliance of its incandescence when it has become heated. The simple experiment indicates the possibilities of light-production in this direction. Naturally, metals of high melting-point such as platinum were tried and a network of platinum wire, in reality a platinum mantle, came into practical use in about 1880. The town of Nantes was lighted by gas-burners using these platinum-gauze mantles, but the mantles were unsuccessful owing to their rapid deterioration. This line of experimentation finally bore fruit of immense value for from it the gas-mantle evolved. A group of so-called "rare-earths," among which are zirconia, thoria, ceria, erbia, and yttria (these are oxides of zirconium, etc.) possess a number of interesting chemical properties some of which have been utilized to advantage in the development of modern artificial light. They are white or yellowish-white oxides of a highly refractory character found in certain rare minerals. Most of them are very brilliant when heated to a high temperature. This latter feature is easily explained if the nature of light and the radiating properties of substances are considered. Suppose pieces of different substances, for example, glass and lime, are heated in a Bunsen flame to the same temperature which is sufficiently great to cause both of them to glow. Notwithstanding the identical conditions of heating, the glass will be only faintly luminous, while the piece of lime will glow brilliantly. The former is a poor radiator; furthermore, the lime radiates a relatively greater percentage of its total energy in the form of luminous energy. The latter point will become clearer if the reader will refresh his memory regarding the nature of light. Any luminous source such as the sun, a candle flame, or an incandescent lamp is sending forth electromagnetic waves not unlike those used in wireless telegraphy excepting that they are of much shorter wave-length. The eye is capable of recording some of these waves as light just as a receiving station is tuned to record a range of wave-lengths of electromagnetic energy. The electromagnetic waves sent forth by a light-source like the sun are not all visible, that is, all of them do not arouse a sensation of light. Those that do comprise the visible spectrum and the different wave-lengths of visible radiant energy manifest themselves by arousing the sensations of the various spectral colors. The radiant energy of shortest wave-length perceptible by the visual apparatus excites the sensation of violet and the longest ones the sensation of deep red. Between these two extremes of the visible spectrum, the chief spectral colors are blue, green, yellow, orange, and red in the order of increasing wave-lengths. Electromagnetic energy radiated by a light-source in waves of too great wave-length to be perceived by the eye as light is termed as a class "infra-red radiant energy." Those too short to be perceived as light are termed as a class "ultraviolet radiant energy." A solid body at a high temperature emits electro-magnetic energy of all wave-lengths, from the shortest ultra-violet to the longest infra-red. Another complication arises in the variation in visibility or luminosity of energy of wave-lengths within the range of the visible spectrum. Obviously, no amount of energy incapable of exciting the sensation of light will be visible. The energy of those wave-lengths near the ends of the visible spectrum will be inefficient in producing light. That energy which excites the sensation of yellow-green produces the greatest luminosity per unit of energy and is the most efficient light. The visibility or luminous efficiency of radiant energy may be ranged approximately in this manner according to the colors aroused: yellow-green, yellow, green, orange, blue-green, red, blue, deep red, violet. Newton, an English scientist, first described the discovery of the visible spectrum and this is of such fundamental importance in the science of light that the first paragraph of his original paper in the "Transactions of the Royal Society of London" is quoted as follows: In the Year 1666 (at which time I applied my self to the Grinding of Optick Glasses of other Figures than Spherical) I procured me a Triangular Glass-Prism, to try therewith the celebrated Phaenomena of Colours. And in order thereto, having darkened my Chamber, and made a small Hole in my Window-Shuts, to let in a convenient Quantity of the Sun's Light, I placed my Prism at its Entrance, that it might be thereby refracted to the opposite Wall. It was at first a very pleasing Divertisement, to view the vivid and intense Colours produced thereby; but after a while applying my self to consider them more circumspectly, I became surprised to see them in an oblong Form; which, according to the receiv'd Law of Refractions, I expected should have been circular. They were terminated at the Sides with streight Lines, but at the Ends the Decay of Light was so gradual, that it was difficult to determine justly what was the Figure, yet they seemed Semicircular. Even Newton could not have had the faintest idea of the great developments which were to be based upon the spectrum. Now to return to the peculiar property of rare-earth oxides--namely, their unusual brilliance when heated in a flame--it is easy to understand the reason for this. For example, when a number of substances are heated to the same temperature they may radiate the same amount of energy and still differ considerably in brightness. Many substances are "selective" in their absorbing and radiating properties. One may radiate more luminous energy and less infra-red energy, and for another the reverse may be true. The former would appear brighter than the latter. The scientific worker in light-production has been searching for such "selective" radiators whose other properties are satisfactory. The rare-earths possess the property of selectivity and are fortunately highly refractory. Welsbach used these in his mantle, whose efficiency is due partly to this selective property. Recent work indicates that much higher efficiencies of light-production are still attainable by the principles involved in the gas-mantle. Turning again to flames, another interesting physical phenomenon is seen on placing solutions of different chemical salts in the flame. For example, if a piece of asbestos is soaked in sodium chloride (common salt) and is placed in a Bunsen flame, the pale-blue flame suddenly becomes luminous and of a yellow color. If this is repeated with other salts, a characteristic color will be noted in each case. The yellow flame is characteristic of sodium and if it is examined by means of a spectroscope, a brilliant yellow line (in fact, a double line) will be seen. This forms the basis of spectrum analysis as applied in chemistry. Every element has its characteristic spectrum consisting usually of lines, but the complexity varies with the elements. The spectra of elements also exhibit lines in the ultra-violet region which may be studied with a photographic plate, with a photo-electric cell, and by other means. Their spectral lines or bands also extend into the infra-red region and here they are studied by means of the bolometer or other apparatus for detecting radiant energy by the heat which it produces upon being absorbed. Spectrum analysis is far more sensitive than the finest weighing balance, for if a grain of salt be dissolved in a barrel of water and an asbestos strip be soaked in the water and held in a Bunsen flame, the yellow color characteristic of sodium will be detectable. A wonderful example of the possibilities of this method is the discovery of helium in the sun before it was found on earth! Its spectral lines were detected in the sun's spectrum and could not be accounted for by any known element. However, it should be stated that the spectrum of an element differs generally with the manner obtained. The electric spark, the arc, the electric discharge in a vacuum tube, and the flame are the means usually employed. The spectrum has been dwelt upon at some length because it is of great importance in light-production and probably will figure strongly in future developments. Although in lighting little use has been made of the injection of chemical salts into ordinary flames, it appears certain that such developments would have risen if electric illuminants had not entered the field. However, the principle has been applied with great success in arc-lamps. In the first arc-lamps plain carbon electrodes were used, but in some of the latest carbon-arcs, electrodes of carbon impregnated with various salts are employed. For example, calcium fluoride gives a brilliant yellow light when used in the carbons of the "flame" arc. These are described in detail later. Following this principle of light-production the vacuum tubes were developed. Crookes studied the light from various gases by enclosing them in a tube which was pumped out until a low vacuum was produced. On connecting a high voltage to electrodes in each end, an electrical discharge passed through the residual gas making it luminous. The different gases show their characteristic spectra and their desirability as light-producers is at once evident. However, the most general principle of light-production at the present time is the radiation of bodies by virtue of their temperature. If a piece of wire be heated by electricity, it will become very hot before it becomes luminous. At this temperature it is emitting only invisible infra-red energy and has an efficiency of zero as a producer of light. As it becomes hotter it begins to appear red, but as its temperature is raised it appears orange, until if it could be heated to the temperature of the sun, about 10,000°F., it would appear white. All this time its luminous efficiency is increasing, because it is radiating not only an increasing percentage of visible radiant energy but an increasing amount of the most effective luminous energy. But even when it appears white, a large amount of the energy which it radiates is invisible infra-red and ultra-violet, which are ineffective in producing light, so at best the substance at this high temperature is inefficient as a light-producer. In this branch of the science of light-production substances are sought not only for their high melting-point, but for their ability to radiate selectively as much visible energy as possible and of the most luminous character. However, at best the present method of utilizing the temperature radiation of hot bodies has limitations. The luminous efficiencies of light-sources to-day are still very low, but great advances have been made in the past half-century. There must be some radical departures if the efficiency of light-production is to reach a much higher figure. A good deal has been said of the firefly and of phosphorescence. These light-sources appear to emit only visible energy and, therefore, are efficient as radiators of luminous radiant energy. But much remains to be unearthed concerning them before they will be generally applicable to lighting. If ultra-violet radiation is allowed to impinge upon a phosphorescent material, it will glow with a considerable brightness but will be cool to the touch. A substance of the same brightness by virtue of its temperature would be hot; hence phosphorescence is said to be "cold" light. An acquaintance with certain terms is necessary if the reader is to understand certain parts of the text. The early candle gradually became a standard, and uniform candles are still satisfactory standards where high accuracy is not required. Their luminous intensity and illuminating value became units just as the foot was arbitrarily adopted as a unit of length. The intensity of other light-sources was represented in terms of the number of candles or fraction of a candle which gave the same amount of light. But the luminous intensity of the candle was taken only in the horizontal direction. In the same manner the luminous intensities of light-sources until a short time ago were expressed in candles as measured in a certain direction. Incandescent lamps were rated in terms of mean horizontal candles, which would be satisfactory if the luminous intensity were the same in all directions, but it is not. Therefore, the candle-power in one direction does not give a measure of the total light-output. If a source of light has a luminous intensity of one candle in all directions, the illumination at a distance of one foot in any direction is said to be a foot-candle. This is the unit of illumination intensity. A lumen is the quantity of light which falls on one square foot if the intensity of illumination is one foot-candle. It is seen that the area of a sphere with a radius of one foot is 4 pi or 12.57 square feet; therefore, a light-source having a luminous intensity of one candle in all directions emits 12.57 lumens. This is the satisfactory unit, for it measures total quantity of light, and luminous efficiencies may be expressed in terms of lumens per watt, lumens per cubic foot of gas per hour, etc. Of course, the efficiencies of light-sources are usually of interest to the consumer if they are expressed in terms of cost. But from a practical point of view there are many elements which combine to make another important factor, namely, satisfactoriness. Therefore, the efficiency of artificial lighting from the standpoint of the consumer should be the ratio of satisfactoriness to cost. However, the scientist is interested chiefly in the efficiency of the light-source which may be expressed in lumens per watt, or the amount of light obtained from a given rate of consumption or of emission of energy. This method of rating light-sources penalizes those radiating considerable energy which does not produce the sensation of light or which at best is of wave-lengths that are inefficient in this respect. That radiant energy which is wholly of a wave-length of maximum visibility, or, in other words, excites the sensation of yellow-green, is the most efficient in producing luminous sensation. Of course, no illuminants are available which approach this theoretical ideal and it is not likely that this would be a practical ideal. Under monochromatic yellow-green light the magical drapery of color would disappear and the surroundings would be a monochrome of shades of this hue. Having no colors with which to contrast this color, the world would be colorless. This should be obvious when it is considered that an object which is red under an illuminant containing all colors such as sunlight would be black or dark gray under monochromatic yellow-green light. The red under present conditions is kept alive by contrast with other colors, because the latter live by virtue of the fact that most of our present illuminants contain their hues. It is assumed that the reader knows that a red object, for example, appears red because it reflects (or transmits) red rays and absorbs the other rays in the illuminant. In other words, color is due to selective absorption reflection, or transmission. Perhaps the ideal illuminant, which is most generally satisfactory for general activities, is a white light corresponding to noon sunlight. If this is chosen as the scientific ideal, the illuminants of the present time are much more "efficient" than if the most efficient light is the ideal. The luminous efficiency of the radiant energy most efficient in producing the sensation of light (yellow-green) is about 625 lumens per watt. That is, if energy of this wave-length alone were radiated by a hypothetical light-source, each watt would produce 625 lumens. The luminous efficiency of the most efficient white light is about 265 lumens per watt; in other words, if a hypothetical light-source radiated energy of only the visible wave-lengths and in proportions to produce the sensation of white, each watt would produce 265 lumens. If such a white light were obtained by pure temperature radiation--that is, by a normal radiator at a temperature of 10,000°F., which is impracticable at present--the luminous efficiency would be about 100 lumens per watt. The normal radiator which emits energy by virtue of its temperature without selectively radiating more or less energy in any part of the spectrum than indicated by the theoretical radiation laws is called a "black-body" or normal radiator. Modern illuminants have luminous efficiencies ranging from 5 to 30 lumens per watt, so it is seen that much is to be done before the limiting efficiencies are reached. The amount of light obtained from various gas-burners for each cubic foot of gas consumed per hour varies for open gas-flames from 5 to 30 lumens; for Argand burners from 35 to 40 lumens; for regenerative lamps from 50 to 75 lumens; and for gas-mantles from 200 to 250 lumens. In the development of light-sources, of course, any harmful effects of gases formed by burning or chemical action must be avoided. Some of the fumes from arcs are harmful, but no commercial arc appears to be dangerous when used as it is intended to be used. Gas-burners rob the atmosphere of oxygen and vitiate it with gases, which, however, are harmless if combustion is complete. That adequate ventilation is necessary where oxygen is being consumed is evident from the data presented by authorities on hygiene. A standard candle when burning vitiates the air in a room almost as much as an adult person. An ordinary kerosene lamp vitiates the atmosphere as much as a half-dozen persons. An ordinary single mantle burner causes as much vitiation as two or three persons. In order to obtain a bird's-eye view of progress in light-production, the following table of relative luminous efficiencies of several light-sources is given in round numbers. These efficiencies are in terms of the most efficient (yellow-green) light. Efficiency in per cent. Sperm-candle 0.02 Open gas-flame .04 Incandescent gas-mantle .19 Carbon filament lamp .05 Vacuum Mazda lamp 1.3 Gas-filled Mazda lamp 2 to 3 Arc-lamps 2 to 7 White light radiated by "black-body" 16 Most efficient white light 40 Firefly 95 Most efficient light (yellow-green) 100 The luminous efficiency of a light-source is distinguished from that of a lamp. The former is the ratio of the light produced to the amount of energy radiated by the light-source. The latter is the ratio of the light produced to the total amount of energy consumed by the device. In other words, the luminous efficiency of a lamp is less than that of the light-source because the consumption of energy in other parts of the lamp besides the light-source are taken into account. These additional losses are appreciable in the mechanisms of arc-lamps but are almost negligible in vacuum incandescent filament lamps. They are unknown for the firefly, so that its luminous efficiency only as a light-source can be determined. Its efficiency as a lighting-plant may be and perhaps is rather low. VIII MODERN GAS-LIGHTING As has been seen, the lighting industry, as a public service, was born in London about a century ago and companies to serve the public were organized on the Continent shortly after. From this early beginning gas-light remained for a long time the only illuminant supplied by a public-service company. It has been seen that throughout the ages little advance was made in lighting until oil-lamps were improved by Argand in the eighteenth century. Candles and open-flame oil-lamps were in use when the Pyramids were built and these were common until the approach of the nineteenth century. In fact, several decades passed after the first gas-lighting was installed before this form of lighting began to displace the improved oil-lamps and candles. It was not until about 1850 that it began to invade the homes of the middle and poorer classes. During the first half of the nineteenth century the total light in an average home was less than is now obtained from a single light-source used in residences; still, the total cost of lighting a residence has decreased considerably. If the social and industrial activities of mankind are visualized for these various periods in parallel with the development of artificial lighting, a close relation is evident. Did artificial light advance merely hand in hand with science, invention, commerce, and industry, or did it illuminate the pathway? Although gas-lighting was born in England it soon began to receive attention elsewhere. In 1815 the first attempt to provide a gas-works in America was made in Philadelphia; but progress was slow, with the result that Baltimore and New York led in the erection of gas-works. There are on record many protests against proposals which meant progress in lighting. These are amusing now, but they indicate the inertia of the people in such matters. When Bollman was projecting a plan for lighting Philadelphia by means of piped gas, a group of prominent citizens submitted a protest in 1833 which aimed to show that the consequences of the use of gas were appalling. But this protest failed and in 1835 a gas-plant was founded in Philadelphia. Thus gas-lighting, which to Sir Walter Scott was a "pestilential innovation" projected by a madman, weathered its early difficulties and grew to be a mighty industry. Continued improvements and increasing output not only altered the course of civilization by increased and adequate lighting but they reduced the cost of lighting over the span of the nineteenth century to a small fraction of its initial cost. Think of the city of Philadelphia in 1800, with a population of about fifty thousand, dependent for its lighting wholly upon candles and oil-lamps! Washington's birthday anniversary was celebrated in 1817 with a grand ball attended by five hundred of the élite. An old report of the occasion states that the room was lighted by two thousand wax-candles. The cost of this lighting was a hundred times the cost of as much light for a similar occasion at the present time. Can one imagine the present complex activities of a city like Philadelphia with nearly two million inhabitants to exist under the lighting conditions of a century ago? To-day there are more than fifty thousand street lamps in the city--one for each inhabitant of a century ago. Of these street lamps about twenty-five thousand burn gas. This single instance is representative of gas-lighting which initiated the "light age" and nursed it through the vicissitudes of youth. The consumption of gas has grown in the United States during this time to three billion cubic feet per day. For strictly illuminating purposes in 1910 nearly one hundred billion cubic feet were used. This country has been blessed with large supplies of natural gas; but as this fails new oil-fields are constantly being discovered, so that as far as raw materials are concerned the future of gas-lighting is assured for a long time to come. The advent of the gas-mantle is responsible for the survival of gas-lighting, because when it appeared electric lamps had already been invented. These were destined to become the formidable light-sources of the approaching century and without the gas-mantle gas-lighting would not have prospered. Auer von Welsbach was conducting a spectroscopic study of the rare-earths when he was confronted with the problem of heating these substances. He immersed cotton in solutions of these salts as a variation of the regular means for studying elements by injecting them into flames. After burning the cotton he found that he had a replica of the original fabric composed of the oxide of the metal, and this glowed brilliantly when left in the flame. This gave him the idea of producing a mantle for illuminating purposes and in 1885 he placed such a mantle in commercial use. His first mantles were unsatisfactory, but they were improved in 1886 by the use of thoria, an oxide of thorium, in conjunction with other rare-earth oxides. His mantle was now not only stronger but it gave more light. Later he greatly improved the mantles by purifying the oxides and finally achieved his great triumph by adding a slight amount of ceria, an oxide of cerium. Welsbach is deserving of a great deal of credit for his extensive work, which overcame many difficulties and finally gave to the world a durable mantle that greatly increased the amount of light previously obtainable from gas. The physical characteristics of a mantle depend upon the fabric and upon the rare-earths used. It must not shrink unduly when burned, and the ash should remain porous. It has been found that a mantle in which thoria is used alone is a poor light-source, but that when a small amount of ceria is added the mantle glows brilliantly. By experiment it was determined that the best proportions for the rare-earth content are one part of ceria and ninety-nine parts of thoria. Greater or less proportions of ceria decreased the light-output. The actual percentage of these oxides in the ash of the mantle is about 10 per cent., making the content of ceria about one part in one thousand. Mantles are made by knitting cylinders of cotton or of other fiber and soaking these in a solution of the nitrates of cerium and thorium. One end of the cylinder is then sewed together with asbestos thread, which also provides the loop for supporting the mantle over the burner. After the mantle has dried in proper form, it is burned; the organic matter disappears and the nitrates are converted into oxides. After this "burning off" has been accomplished and any residual blackening is removed, the mantle is dipped into collodion, which strengthens it for shipping and handling. The collodion is a solution of gun-cotton in alcohol and ether to which an oil such as castor-oil has been added to prevent excessive shrinkage on drying. The materials and structure of the fabric of mantles have been subjected to much study. Cotton was first used; then ramie fibers were introduced. The ramie mantle was found to possess a greater life than the cotton mantle. Later the mantles were mercerized by immersion in ammonia-water and this process yielded a stronger material. The latest development is the use of an artificial silk as the base fabric, which results in a mantle superior to previous mantles in strength, flexibility, permanence of form, and permanence of luminous property. This artificial silk mantle will permit of handling even after it has been in use for several hundred hours. This great advance appears to be due to the fact that after the artificial-silk fibers have been burned off, the fibers are solid and continuous instead of porous as in previous mantles. The color-value of the light from mantles may be varied considerably by altering the proportions of the rare-earths. The yellowness of the light has been traced to ceria, so by varying the proportions of ceria, the color of the light may be influenced. The inverted mantle introduced greater possibilities into gas-lighting. The light could be directed downward with ease and many units such as inverted bowls were developed. In fact, the lighting-fixtures and the lighting-effects obtainable kept pace with those of electric lighting, notwithstanding the greater difficulties encountered by the designer of gas-lighting fixtures. Many problems were encountered in designing an inverted burner operating on the Bunsen principle, but they were finally satisfactorily solved. In recent years a great deal of study has been given to the efficiency of gas-burners, with the result that a high level of development has been reached. Several methods of electrical ignition have been evolved which in general employ the electric spark. Electrical ignition and developments of remote control have added great improvements especially to street-lighting by means of gas. Gas-valves for remote control are actuated by gas pressure and by electromagnets. In general, the gas-lighting engineers have kept pace marvelously with electric lighting, when their handicaps are considered. Various types of burners have appeared which aimed to burn more gas in a given time under a mantle and thereby to increase the output of light. These led to the development of the pressure system in which the pressure of gas was at first several times greater than usual. The gas is fed into the mixing tube under this higher pressure in a manner which also draws in an adequate amount of air. In this way the combustion at the burner is forced beyond the point reached with the usual pressure. Ordinary gas pressure is equal to that of a few inches of water, but high-pressure systems employ pressures as great as sixty inches of water. Under this high-pressure system, mantle-burners yield as high as 500 lumens per cubic foot of gas per hour. The fuels for gas-lighting are natural gas, carbureted water-gas, and coal-gas obtained by distilling coal, but there are different methods of producing the artificial gases. Coal-gas is produced analytically by distilling certain kinds of coal, but water-gas and producer-gas are made synthetically by the action of several constituents upon one another. Carbureted water-gas is made from fixed carbon, steam, and oil and also from steam and oil. Producer-gas is made by the action of steam or air or both upon fixed carbon. Water-gas made from steam and oil is usually limited to those places where the raw materials are readily available. The composition of a gas determines its heating and illuminating values, and constituents favorable to one are not necessarily favorable to the other. Coal-gas usually is of lower illuminating value than carbureted water-gas. It contains more hydrogen, for example, than water-gas and it is well known that hydrogen gives little light on burning. It has been seen in a previous chapter that the distillation of gas from coal for illuminating purposes began in the latter part of the eighteenth century. From this beginning the manufacture of coal-gas has been developed to a great and complex industry. The method is essentially destructive distillation. The coal is placed in a retort and when it reaches a temperature of about 700°F. through heating by an outside fire, the coal begins to fuse and hydrocarbon vapors begin to emanate. These are generally paraffins and olefins. As the temperature increases, these hydrocarbons begin to be affected. The chemical combinations which have long existed are broken up and there are rearrangements of the atoms of carbon and hydrogen. The actual chemical reactions become very complex and are somewhat shrouded in uncertainty. In this last stage the illuminating and heating values of the gas are determined. Usually about four hours are allowed for the complete distillation of the gaseous and liquid products from a charge of coal. Many interesting chemical problems arise in this process and the influences of temperature and time cannot be discussed within the scope of this book. Besides the coal-gas, various by-products are obtained depending upon the raw materials, upon the procedure, and upon the market. After the coal-gas is produced it must be purified and the sulphureted hydrogen at least must be removed. One method of accomplishing this is by washing the gas with water and ammonia, which also removes some of the carbon dioxide and hydrocyanic acid. Various other undesirable constituents are removed by chemical means, depending upon the conditions. The purified gas is now delivered to the gas-holder; but, of course, all this time the pressure is governed, in order that the pressure in the mains will be maintained constant. Much attention has been given to the enrichment of gas for illuminating purposes; that is, to produce a gas of high illuminating value from cheap fuel or by inexpensive processes. This has been done by decomposing the tar obtained during the distillation of coal and adding these gases to the coal-gas; by mixing carbureted water-gas with coal-gas; by carbureting inferior coal-gases; and by mixing oil-gas with inferior coal-gas. Water-gas is of low illuminating value, but after it is carbureted it burns with a brilliant flame. The water-gas is made by raising the temperature of the fuel bed of hard coal or coke by forced air, which is then cut off, while steam is passed through the incandescent fuel. This yields hydrogen and carbon monoxide. To make carbureted water-gas, oil-gas is mixed with it, the latter being made by heating oil in retorts. A great many kinds of gas are made which are determined by the requirements and the raw materials available. The amount of illuminating gas yielded by a ton of fuel, of course, varies with the method of manufacture, with the raw material, and with the use to which the fuel is to be put. The production of coal-gas per ton of coal is of the order of magnitude of 10,000 cubic feet. A typical yield by weight of a coal-gas retort is, 10,000 cubic feet of gas 17 per cent. coke 70 " " tar 5 " " ammoniacal liquid 8 " " The coke is not pure carbon but contains the non-volatile minerals which will remain as ash when the coke is burned, just as if the original coal had been burned. On the crown of the retort used in coal-gas production, pure carbon is deposited. This is used for electric-arc carbons and for other purposes. From the tar many products are derived such as aniline dyes, benzene, carbolic acid, picric acid, napthalene, pitch, anthracene, and saccharin. A typical analysis of the gas distilled from coal is very approximately as follows, Hydrocarbons 40 per cent. Hydrogen 50 " " Carbon monoxide 4 " " Nitrogen 4 " " Carbon dioxide 1 " " Various other gases 1 " " It is seen that illuminating gas is not a definite compound but a mixture of a number of gases. The proportion of these is controlled in so far as possible in order to obtain illuminating value and some of them are reduced to very small percentages because they are valueless as illuminants or even harmful. The constituents are seen to consist of light-giving hydrocarbons, of gases which yield chiefly heat, and of impurities. The chief hydrocarbons found in illuminating gas are, ethylene C_{2}H_{4} crotonylene C_{4}H_{6} propylene C_{3}H_{6} benzene C_{6}H_{6} butylene C_{4}H_{8} toluene C_{7}H_{8} amylene C_{5}H_{10} xylene C_{8}H_{10} acetylene C_{2}H_{2} methane C H_{4} allylene C_{3}H_{4} ethane C_{2}H_{6} A gas which has played a prominent part in lighting is acetylene, produced by the interaction of water and calcium carbide. No other gas easily produced upon a commercial scale yields as much light, volume for volume, as acetylene. It has the great advantage of being easily prepared from raw material whose yield of gas is considerably greater for a given amount than the raw materials which are used in making other illuminating gases. The simplicity of the manufacture of acetylene from calcium carbide and water gives to this gas a great advantage in some cases. It has served for individual lighting in houses and in other places where gas or electric service was unavailable. Where space is limited it also had an advantage and was adopted to some extent on automobiles, motor-boats, ships, lighthouses, and railway cars before electric lighting was developed for these purposes. The color of the acetylene flame is satisfactory and it is extremely brilliant compared with most flames. An interesting experiment is found in placing a spark-gap in the flame and sending a series of sparks across it. If the conditions are proper the flame will became very much brighter. When the gas issues from a proper jet under sufficient pressure, the flame is quite steady. Its luminous efficiency gives it an advantage over other open gas-flames in lighting rooms, because for the same amount of light it vitiates the air and exhausts the oxygen to a less degree than the others. Of course, in these respects the gas-mantle is superior. The reaction which takes place when water and calcium carbide are brought together is a double decomposition and is represented by, CaC_{2} + H_{2}O = C_{2}H_{2} + CaO It will be seen that the products are acetylene gas and calcium oxide or lime. The lime, being hydroscopic and being in the presence of water or water-vapor in the acetylene generator, really becomes calcium hydroxide Ca(OH)_{2}, commonly called slaked lime. If there are impurities in the calcium carbide, it is sometimes necessary to purify the gas before it may be safely used for interior lighting. The burners and mantles used in acetylene lighting are essentially the same as those for other gas-lighting, excepting, of course, that they are especially adapted for it in minor details. The chief source of calcium carbide in this country is the electric furnace. Cheap electrical energy from hydro-electric developments, such as the Niagara plants, have done much to make the earth yield its elements. Aluminum is very prevalent in the soil of the earth's surface, because its oxide, alumina, is a chief constituent of ordinary clay. But the elements, aluminum and oxygen, cling tenaciously to each other and only the electric furnace with its excessively high temperatures has been able to separate them on a large commercial scale. Similarly, calcium is found in various compounds over the earth's surface. Limestone abounds widely, hence the oxide and carbonate of lime are wide-spread. But calcium clings tightly to the other elements of its compounds and it has taken the electric furnace to bring it to submission. The cheapness of calcium carbide is due to the development of cheap electric power. It is said that calcium carbide was discovered as a by-product of the electric furnace by accidentally throwing water upon the waste materials of a furnace process. The discovery of a commercial scale of manufacture of calcium carbide has been a boon to isolated lighting. Electric lighting has usurped its place on the automobile and is making inroads in country-home lighting. Doubtless, acetylene will continue to serve for many years, but its future does not appear as bright as it did many years ago. The Pintsch gas, used to some extent in railroad passenger-cars in this country, is an oil-gas produced by the destructive distillation of petroleum or other mineral oil in retorts heated externally. The product consists chiefly of methane and heavy hydrocarbons with a small amount of hydrogen. In the early days of railways, some trains were not run after dark and those which were operated were not always lighted. At first attempts were made at lighting railway cars with compressed coal-gas, but the disadvantage of this was the large tank required. Obviously, a gas of higher illuminating-value per volume was desired where limited storage space was available, and Pintsch turned his attention to oil-gas. Gas suffers in illuminating-value upon being compressed, but oil-gas suffers only about half the loss that coal-gas does. In about 1880 Pintsch developed a method of welding cylinders and buoys which satisfied lighthouse authorities and he was enabled to furnish these filled with compressed gas. Thus the buoy was its own gas-tank. He devised lanterns which would remain lighted regardless of wind and waves and thus gained a start with his compressed-gas systems. He compressed the gas to a pressure of about one hundred and fifty pounds per square inch and was obliged to devise a reducer which would deliver the gas to the burner at about one pound per square inch. This regulator served well throughout many years of exacting service. The system began to be adopted on ships and railroads in 1880 and for many years it has served well. Although gas-lighting has affected the activities of mankind considerably by intensifying commerce and industry and by advancing social progress, the illuminants which eventually took the lead have extended the possibilities and influences of artificial light. In the brief span of a century civilized man is almost totally independent of natural light in those fields over which he has control. What another century will bring can be predicted only from the accomplishments of the past. These indicate possibilities beyond the powers of imagination. IX THE ELECTRIC ARCS Early in 1800 Volta wrote a letter to the President of the Royal Society of London announcing the epochal discovery of a device now known as the voltaic pile. This letter was published in the Transactions and it created great excitement among scientific men, who immediately began active investigations of certain electrical phenomena. Volta showed that all metals could be arranged in a series so that each one would indicate a positive electric potential when in contact with any metal following it in the series. He constructed a pile of metal disks consisting of zinc and copper alternated and separated by wet cloths. At first he believed that mere contact was sufficient, but when, later, it was shown that chemical action took place, rapid progress was made in the construction of voltaic cells. The next step after his pile was constructed was to place pairs of strips of copper and zinc in cups containing water or dilute acid. Volta received many honors for his discovery, which contributed so much to the development of electrical science and art--among them a call to Paris by Bonaparte to exhibit his electrical experiments, and to receive a medal struck in his honor. While Volta was being showered with honors, various scientific men with great enthusiasm were entering new fields of research, among which was the heating value of electric current and particularly of electric sparks made by breaking a circuit. Late in 1800 Sir Humphrey Davy was the first to use charcoal for the sparking points. In a lecture before the Royal Society in the following year he described and demonstrated that the "spark" passing between two pieces of charcoal was larger and more brilliant than between brass spheres. Apparently, he was producing a feeble arc, rather than a pure spark. In the years which immediately followed many scientific men in England, France, and Germany were publishing the results of their studies of electrical phenomena bordering upon the arc. By subscription among the members of the Royal Society, a voltaic battery of two thousand cells was obtained and in 1808 Davy exhibited the electric arc on a large scale. It is difficult to judge from the reports of these early investigations who was the first to recognize the difference between the spark and the arc. Certainly the descriptions indicate that the simple spark was not being experimented with, but the source of electric current available at that time was of such high resistance that only feeble arcs could have been produced. In 1809 Davy demonstrated publicly an arc obtained by a current from a Volta pile of one thousand plates. This he described as "a most brilliant flame, of from half an inch to one and a quarter inches in length." In the library of the Royal Society, Davy's notes made during the years of 1805 and 1812 are available in two large volumes. These were arranged and paged by Faraday, who was destined to contribute greatly to the future development of the science and art of electricity. In one of these volumes is found an account of a lecture-experiment by Davy which certainly is a description of the electric arc. An extract of this account is as follows: The spark [presumably the arc], the light of which was so intense as to resemble that of the sun, ... produced a discharge through heated air nearly three inches in length, and of a dazzling splendor. Several bodies which had not been fused before were fused by this flame.... Charcoal was made to evaporate, and plumbago appeared to fuse in vacuo. Charcoal was ignited to intense whiteness by it in oxymuriatic acid, and volatilized by it, but without being decomposed. From a consideration of his source of electricity, a voltaic pile of two thousand plates, it is certain that this could not have been an electric spark. Later in his notes Davy continued: ...the charcoal became ignited to whitness, and by withdrawing the points from each other, a constant discharge took place through the heated air, in a space at least equal to four inches, producing a most brilliant ascending arch of light, broad and conical in form in the middle. This is surely a description of the electric arc. Apparently the electrodes were in a horizontal position and the arc therefore was horizontal. Owing to the rise of the heated air, the arc tended to rise in the form of an arch. From this appearance the term "arc" evolved and Davy himself in 1820 definitely named the electric flame, the "arc." This name was continued in use even after the two carbons were arranged in a vertical co-axial position and the arc no more "arched." An interesting scientific event of 1820 was the discovery by Arago and by Davy independently that the arc could be deflected by a magnet and that it was similar to a wire carrying current in that there was a magnetic field around it. This has been taken advantage of in certain modern arc-lamps in which inclined carbons are used. In these arcs a magnet keeps the arc in place, for without the magnet the arc would tend to climb up the carbons and go out. In 1838 Gassiot made the discovery that the temperature of the positive electrode of an electric arc is much greater than that of the negative electrode. This is explained in electronic theory by the bombardment of the positive electrode by negative electrons or corpuscles of electricity. This temperature-difference was later taken into account in designing direct-current arc-lamps, for inasmuch as most of the light from an ordinary arc is emitted by the end of the positive electrode, this was placed above the negative electrode. In this manner most of the light from the arc is directed downward where desired. In the few instances in modern times where the ordinary direct-current arc has been used for indirect lighting, in which case the arc is above an inverted shade, the positive carbon is placed below the negative one. Gassiot first proved that the positive electrode is hotter than the negative one by striking an arc between the ends of two horizontal wires of the same substance and diameter. After the arc operated for some time, the positive wire was melted for such a distance that it bent downward, but the negative remained quite straight. Charcoal was used for the electrodes in all the early experiments, but owing to the intense heat of the arc, it burned away rapidly. A progressive step was made in 1843 when electrodes were first made by Foucault from the carbon deposited in retorts in which coal was distilled in the production of coal-gas. However, charcoal, owing to its soft porous character, gives a longer arc and a larger flame. In 1877 the "cored" carbons were introduced. These consist of hard molded carbon rods in which there is a core of soft carbon. In these are combined the advantages of charcoal and hard carbon and the core in burning away more rapidly has a tendency to hold the arc in the center. Modern carbons for ordinary arc-lamps are generally made of a mixture of retort-carbon, soot, and coal-tar. This paste is forced through dies and the carbons are baked at a fairly high temperature. A variation in the hardness of the carbons may be obtained as the requirements demand by varying the proportions of soot and retort-carbon. Cored carbons are made by inserting a small rod in the center of the die and the carbons are formed with a hollow core. This may be filled with a softer carbon. If two carbons connected to a source of electric current are brought together, the circuit is completed and a current flows. If the two carbons are now slightly separated, an arc will be formed. As the arc burns the carbons waste away and in the case of direct current, the positive decreases in length more rapidly than the negative one. This is due largely to the extremely high temperature of the positive tip, where the carbon fairly boils. A crater is formed at the positive tip and this is always characteristic of the positive carbon of the ordinary arc, although it becomes more shallow as the arc-length is increased. The negative tip has a bright spot to which one end of the arc is attached. By wasting away, the length of the arc increases and likewise its resistance, until finally insufficient current will pass to maintain the arc. It then goes out and to start it the carbons must be brought together and separated. The mechanisms of modern arc-lamps perform these functions automatically by the ingenious use of electromagnets. The interior of the arc is of a violet color and the exterior is a greenish yellow. The white-hot spot on the negative tip is generally surrounded by a fringe of agitated globules which consist of tar and other ingredients of carbons. Often material is deposited from the positive crater upon the negative tip and these accretions may build up a rounded tip. This deposit sometimes interferes with the proper formation of the arc and also with the light from the arc. It is often responsible for the hissing noise, although this hissing occurs with any length of arc when the current is sufficiently increased. The hissing seems to be due to the crater enlarging under excessive current until it passes the confines of the cross-section of the carbon. It thus tends to run up the side, where it comes in contact with oxygen of the air. In this manner the carbon is directly burned instead of being vaporized, as it is when the hot crater is small and is protected from the air by the arc itself. The temperature of the positive crater is in the neighborhood of 6000° to 7000°F. The brightness of the arc under pressure is the greatest produced by artificial means and is very intense. By putting the arc under high pressure, the brightness of the sun may be attained. The temperature of the hottest spot on the negative tip is about a thousand degrees below that of the positive. No great demand arose for arc-lamps until the development of the Gramme dynamo in 1870, which provided a practicable source of electric current. In 1876 Jablochkov invented his famous "electric candle" consisting of two rods of carbon placed side by side but separated by insulating material. In this country Brush was the pioneer in the development of open arc-lamps. In 1877 he invented an arc-lamp and an efficient form of dynamo to supply the electrical energy. The first arc-lamps were ordinary direct-current open arcs and the carbons were made from high-grade coke, lampblack, and syrup. The upper positive carbon in these lamps is consumed at a rate of one to two inches per hour. Inasmuch as about 85 per cent. of the total light is emitted by the upper (positive) carbon and most of this from the crater, the lower carbon is made as small as possible in order not to obstruct any more light than necessary. The positive carbon of the open arc is often cored and the negative is a smaller one of solid carbon. This combination operates quite satisfactorily, but sometimes solid carbons are used outdoors. The voltage across the arc is about 50 volts. In 1846 Staite discovered that the carbons of an arc enclosed in a glass vessel into which the air was not freely admitted were consumed less rapidly than when the arc operated in the open air. After the appearance of the dynamo, when increased attention was given to the development of arc-lamps, this principle of enclosing the arcs was again considered. The early attempts in about 1880 were unsuccessful because low voltages were used and it was not until the discovery was made that the negative tip builds up considerably for voltages under 65 volts, that higher voltages were employed. In 1893 marked improvements were consummated and Jandus brought out a successful enclosed arc operating at 80 volts. Marks contributed largely to the success of the enclosed arc by showing that a small current and a high voltage of 80 to 85 volts were the requisites for a satisfactory enclosed arc. The principle of the enclosed arc is simple. A closely fitting glass globe surrounds the arc, the fit being as close as the feeding of the carbons will permit. When the arc is struck the oxygen is rapidly consumed and the heated gases and the enclosure check the supply of fresh air. The result is that the carbons are consumed about one tenth as rapidly as in the open arc. There is no crater formed on the positive tip and the arc wanders considerably. The efficiency of the enclosed arc as a light-producer is lower than that of the open arc, but it found favor because of its slow rate of consumption of the carbons and consequent decreased attention necessary. This arc operates a hundred hours or more without trimming, and will therefore operate a week or more in street-lighting without attention. When it is considered that open arcs for all-night burning were supplied with two pairs of carbons, the second set going into use automatically when the first were consumed, the value of the enclosed arc is apparent. However, the open arc has served well and has given way to greater improvements. It is rapidly disappearing from use. The alternating-current arc-lamp was developed after the appearance of the direct-current open-arc and has been widely used. It has no positive or negative carbons, for the alternating current is reversing in direction usually at the rate of 120 times per second; that is, it passes through 60 complete cycles during each second. No marked craters form on the tips and the two carbons are consumed at about the same rate. The average temperature of the carbon tips is lower than that of the positive tip of a direct-current arc, with the result that the luminous efficiency is lower. These arcs have been made of both the open and enclosed type. They are characterized by a humming noise due to the effect of alternating current upon the mechanism and also upon the air near the arc. This humming sound is quite different from the occasional hissing of a direct-current arc. When soft carbons are used, the arc is larger and apparently this mass of vapor reduces the humming considerably. The humming is not very apparent for the enclosed alternating-current arc. The alternating arc can easily be detected by closely observing moving objects. If a pencil or coin be moved rapidly, a number of images appear which are due to the pulsating character of the light. At each reversal of the current, the current reaches zero value and the arc is virtually extinguished. Therefore, there is a maximum brightness midway between the reversals. Various types of all these arcs have been developed to meet the different requirements of ordinary lighting and to adapt this method of light-production to the needs of projection, stage-equipment, lighthouses, search-lights, and other applications. Up to this point the ordinary carbon arc has been considered and it has been seen that most of the light is emitted by the glowing end of the positive carbon. In fact, the light from the arc itself is negligible. A logical step in the development of the arc-lamp was to introduce salts in order to obtain a luminous flame. This possibility as applied to ordinary gas-flames had been known for years and it is surprising that it had not been early applied to carbons. Apparently Bremer in 1898 was the first to introduce fluorides of calcium, barium, and strontium. The salts deflagrate and a luminous flame envelops the ordinary feeble arc-flame. From these arcs most of the light is emitted by the arc itself, hence the name "flame-arcs." By the introduction of metallic salts into the carbons the possibilities of the arc-lamp were greatly extended. The luminous output of such lamps is much greater than that of an ordinary carbon arc using the same amount of electrical energy. Furthermore, the color or spectral character of the light may be varied through a wide range by the use of various salts. For example, if carbons are impregnated with calcium fluoride, the arc-flame when examined by means of a spectroscope will be seen to contain the characteristic spectrum of calcium, namely, some green, orange, and red rays. These combine to give to this arc a very yellow color. As explained in a previous chapter, the salts for this purpose may be wisely chosen from a knowledge of their fundamental or characteristic flame-spectra. These lamps have been developed to meet a variety of needs and their luminous efficiencies range from 20 to 40 lumens per watt, being several times that of the ordinary carbon open-arc. The red flame-arc owes its color chiefly to strontium, whose characteristic visible spectrum consists chiefly of red and yellow rays. Barium gives to the arc a fairly white color. The yellow and so-called white flame-arcs have been most commonly used. Flame-arcs have been produced which are close to daylight in color, and powerful blue-white flame-arcs have satisfied the needs of various chemical industries and photographic processes. These arcs are generally operated in a space where the air-supply is restricted similar to the enclosed-arc principle. Inasmuch as poisonous fumes are emitted in large quantities from some flame-arcs, they are not used indoors without rather generous ventilation. In fact, the flame-arcs are such powerful light-sources that they are almost entirely used outdoors or in very large interiors especially of the type of open factory buildings. They are made for both direct and alternating current and the mechanisms have been of several types. The electrodes are consumed rather rapidly so they are made as long as possible. In one type of arc, the carbons are both fed downward, their lower ends forming a narrow V with the arc-flame between their tips. Under these conditions the arc tends to travel vertically and finally to "stretch" itself to extinction. However, the arc is kept in place by means of a magnet above it which repels the arc and holds it at the ends of the carbons. The chief objection to the early flame-arcs was the necessity for frequent renewal of the carbons. This was overcome to a large extent in the Jandus regenerative lamp in which the arc operates in a glass enclosure surrounded by an opal globe. However, in addition to the inner glass enclosure, two cooling chambers of metal are attached to it. Air enters at the bottom and the fumes from the arc pass upward and into the cooling chambers, where the solid products are deposited. The air on returning to the bottom is thus relieved of these solids and the inner glass enclosure remains fairly clean. The lower carbon is impregnated with salts for producing the luminous flame and the upper carbon is cored. The life of the electrodes is about seventy-five hours. The next step was the introduction of the so-called "luminous-arc" which is a "flame-arc" with entirely different electrodes. The lower (negative) electrode consists of an iron tube packed chiefly with magnetite (an iron oxide) and titanium oxide in the approximate proportions of three to one respectively. The magnetite is a conductor of electricity which is easily vaporized. The arc-flame is large and the titanium gives it a high brilliancy. The positive electrode, usually the upper one, is a short, thick, solid cylinder of copper, which is consumed very slowly. This lamp, known as the magnetite-arc, has a luminous efficiency of about 20 lumens per watt with a clear glass globe. The mechanisms which strike the arc and feed the carbons are ingenious devices of many designs depending upon the kind of arc and upon the character of the electric circuit to which it is connected. Late developments in electric incandescent filament lamps have usurped some of the fields in which the arc-lamp reigned supreme for years and its future does not appear as bright now as it did ten years ago. High-intensity arcs have been devised with small carbons for special purposes and considered as a whole a great amount of ingenuity has been expended in the development of arc-lamps. There will be a continued demand for arc-lamps, for scientific developments are opening new fields for them. Their value in photo-engraving, in the moving-picture production studios, in moving-picture projection, and in certain aspects of stage-lighting is firmly established, and it appears that they will find application in certain chemical industries because the arc is a powerful source of radiant energy which is very active in its effects upon chemical reactions. The luminous efficiencies of arc-lamps depend upon so many conditions that it is difficult to present a concise comparison; however, the following may suffice to show the ranges of luminous output per watt under actual conditions of usage. These efficiencies, of course, are less than the efficiencies of the arc alone, because the losses in the mechanism, globes, etc., are included. Lumens per watt Open carbon arc 4 to 8 Enclosed carbon arc 3 to 7 Enclosed flame-arc (yellow or white) 15 to 25 Luminous arc 10 to 25 Another lamp differing widely in appearance from the preceding arcs may be described here because it is known as the mercury-arc. In this lamp mercury is confined in a transparent tube and an arc is started by making and breaking a mercury connection between the two electrodes. The arc may be maintained of a length of several feet. Perhaps the first mercury-arc was produced in 1860 by Way, who permitted a fine jet of mercury to fall from a reservoir into a vessel, the reservoir and receiver being connected to the poles of a battery. The electric current scattered the jet and between the drops arcs were formed. He exhibited this novel light-source on the mast of a yacht and it received great attention. Later, various investigators experimented on the production of a mercury-arc and the first successful ones were made in the form of an inverted U-tube with the ends filled with mercury and the remainder of the tube exhausted. Cooper Hewitt was a successful pioneer in the production of practicable mercury-arcs. He made them chiefly in the form of straight tubes of glass up to several feet in length, with enlarged ends to facilitate cooling. The tubes are inclined so that the mercury vapor which condenses will run back into the enlarged end, where a pool of mercury forms the negative electrode. The arc may be started by tilting the tube so that a mercury thread runs down the side and connects with the positive electrode of iron. The heat of the arc volatilizes the mercury so that an arc of considerable length is maintained. The tilting is done by electromagnets. Starting has also been accomplished by means of a heating coil and also by an electric spark. The lamps are stabilized by resistance and inductance coils. One of the defects of the light emitted by the incandescent vapor of mercury is its paucity of spectral colors. Its visible spectrum consists chiefly of violet, blue, green, and yellow rays. It emits virtually no red rays, and, therefore, red objects appear devoid of red. The human face appears ghastly under this light and it distorts colors in general. However, it possesses the advantages of high efficiency, of reasonably low brightness, of high actinic value, and of revealing detail clearly. Various attempts have been made to improve the color of the light by adding red rays. Reflectors of a fluorescent red dye have been used with some success, but such a method reduces the luminous efficiency of the lamp considerably. The dye fluoresces red under the illumination of ultra-violet, violet, and blue rays; that is, it has the property of converting radiation of these wave-lengths into radiant energy of longer wave-lengths. By the use of electric incandescent filament lamps in conjunction with mercury-arcs, a fairly satisfactory light is obtained. Many experiments have been made by adding other substances to the mercury, such as zinc, with the hope that the spectrum of the other substance would compensate the defects in the mercury spectrum. However no success has been reached in this direction. By the use of a quartz tube which can withstand a much higher temperature than glass, the current density can be greatly increased. Thus a small quartz tube of incandescent mercury vapor will emit as much light as a long glass tube. The quartz mercury-arc produces a light which is almost white, but the actual spectrum is very different from that of white sunlight. Although some red rays are emitted by the quartz arc, its spectrum is essentially the same as that of the glass-tube arc. Quartz transmits ultra-violet radiation, which is harmful to the eyes, and inasmuch as the mercury vapor emits such rays, a glass globe should be used to enclose the quartz tube when the lamp is used for ordinary lighting purposes. It is fortunate that such radically different kinds of light-sources are available, for in the complex activities of the present time all are in demand. The quartz mercury-arc finds many isolated uses, owing to its wealth of ultra-violet radiation. It is valuable as a source of ultra-violet for exciting phosphorescence, for examining the transmission of glasses for this radiation, for sterilizing water, for medical purposes, and for photography. X THE ELECTRIC INCANDESCENT FILAMENT LAMPS Prior to 1800 electricity was chiefly a plaything for men of scientific tendencies and it was not until Volta invented the electric pile or battery that certain scientific men gave their entire attention to the study of electricity. Volta was not merely an inventor, for he was one of the greatest scientists of his period, endowed with an imagination which marked him as a genius in creative work. By contributing the electric battery, he added the greatest impetus to research in electrical science that it has ever received. As has already been shown, there began a period of enthusiastic research in the general field of heating effects of electric current. The electric arc was born in the cradle of this enthusiasm, and in the heating of metals by electricity the future incandescent lamp had its beginning. Between the years 1841 and 1848 several inventors attempted to make light-sources by heating metals. These crude lamps were operated by means of Grove and Bunsen electric cells, but no practicable incandescent filament lamps were brought out until the development of the electric dynamo supplied an adequate source of electric current. As electrical science progressed through the continued efforts of scientific men, it finally became evident that an adequate supply of electric current could be obtained by mechanical means; that is, by rotating conductors in such a manner that current would be generated within them as they cut through a magnetic field. Even the pioneer inventors of electric lamps made great contributions to electrical practice by developing the dynamo. Brush developed a satisfactory dynamo coincidental with his invention of the arc-lamp, and in a similar manner, Edison made a great contribution to electrical practice in devising means of generating and distributing electricity for the purpose of serving his filament lamp. [Illustration: DIRECT CURRENT ARC Most of the light being emitted by the positive (upper) electrode] [Illustration: FLAME ARC Most of the light being emitted by the flame] [Illustration: ON THE TESTING-RACKS OF THE MANUFACTURER OF INCANDESCENT FILAMENT LAMPS Thousands of lamps are burned out for the sake of making improvements. The electrical energy used is equivalent to that consumed by a city of 30,000 inhabitants] Edison in 1878 attacked the problem of producing light from a wire or filament heated electrically. He used platinum wire in his first experiments, but its volatility and low melting-point (3200°F.) limited the success of the lamps. Carbon with its extremely high melting-point had long attracted attention and in 1879 Edison produced a carbon filament by carbonizing a strip of paper. He sealed this in a vessel of glass from which the air was exhausted and the electric current was led to the filament through platinum wires sealed in the glass. Platinum was used because its expansion and contraction is about the same as glass. Incidentally, many improvements were made in incandescent lamps and thirty years passed before a material was found to replace the platinum leading-in wires. The cost of platinum steadily increased and finally in the present century a substitute was made by the use of two metals whose combined expansion was the same as that of platinum or glass. In 1879 and 1880 Edison had succeeded in overcoming the many difficulties sufficiently to give to the world a practicable incandescent filament lamp. About this time Swan and Stearn in England had also produced a successful lamp. In Edison's early experiments with filaments he used platinum wire coated with carbon but without much success. He also made thin rods of a mixture of finely divided metals such as platinum and iridium mixed with such oxides as magnesia, zirconia, and lime. He even coiled platinum wire around a piece of one of these oxides, with the aim of obtaining light from the wire and from the heated oxide. However, these experiments served little purpose besides indicating that the filament was best if it consisted solely of carbon and that it should be contained in an evacuated vessel. One of the chief difficulties was to make the carbon filaments. Some of the pioneers, such as Sawyer and Mann, attempted to cut these from a piece of carbon. However, Edison and also Swan turned their attention to forming them by carbonizing a fiber of organic matter. Filaments cut from paper and threads of cotton and silk were carbonized for this purpose. Edison scoured the earth for better materials. He tried a fibrous grass from South America and various kinds of bamboo from other parts of the world. Thin filaments of split bamboo eventually proved the best material up to that time. He made many lamps containing filaments of this material, and even until 1910 bamboo was used to some extent in certain lamps. Of these early days, Edison said: It occurred to me that perhaps a filament of carbon could be made to stand in sealed glass vessels, or bulbs, which we were using, exhausted to a high vacuum. Separate lamps were made in this way independent of the air-pump, and, in October, 1879, we made lamps of paper carbon, and with carbons of common sewing thread, placed in a receiver or bulb made entirely of glass, with the leading-in wires sealed in by fusion. The whole thing was exhausted by the Sprengel pump to nearly one-millionth of an atmosphere. The filaments of carbon, although naturally quite fragile owing to their length and small mass, had a smaller radiating surface and higher resistance than we had dared hope. We had virtually reached the position and condition where the carbons were stable. In other words, the incandescent lamp as we still know it to-day [1904], in essentially all its particulars unchanged, had been born. After Edison's later success with bamboo, Swan invented a process of squirting filaments of nitrocellulose into a coagulating liquid, after which they are carbonized. Very fine uniform filaments can be made by this process and although improvements have been made from time to time, this method has been employed ever since its invention. In these later years cotton is dissolved in a suitable solvent such as a solution of zinc chloride and this material is forced through a small diamond die. This thread when hardened appears similar to cat-gut. It is cut into proper lengths and bent upon a form. It is then immersed in plumbago and heated to a high temperature in order to destroy the organic matter. A carbon filament is the result. From this point to the finished lamp many operations are performed, but a discussion of these would lead far afield. The production of a high vacuum is one of the most important processes and manufacturers of incandescent lamps have mastered the art perhaps more thoroughly than any other manufacturers. At least, their experience in this field made it possible for them to produce quickly and on a large scale such devices as X-ray tubes during the recent war. During the early years of incandescent lamps, improvements were made from time to time which increased the life and the luminous efficiency of the carbon filaments, but it was not until 1906 that any radical improvement was achieved. In that year in this country a process was devised whereby the carbon filament was made more compact. In fact, from its appearance it received the name "metallized filament." These carbon filaments are prepared in the same manner as the earlier ones but are finally "treated" by heating in an atmosphere of hydrocarbons such as coal-gas. The filament is heated by electric current and the heat breaks down the hydrocarbons, with the result that carbon is deposited upon the filament. This "treated" filament has a coating of hard carbon and its electrical resistance is greater than that of the untreated filament. The luminous efficiency of a carbon filament is a function of its temperature and it increases very rapidly with increasing temperature. For this reason it is a constant aim to reach high filament temperatures. Of all the materials used in filaments up to the present time, carbon possesses the highest melting-point (perhaps as high as 7000°F.), but the carbon filament as operated in practice has a lower efficiency than any other filament. This is because the highest temperature at which it can be operated and still have a reasonable life is much lower than that of metallic filaments. The incandescent carbon in the evacuated bulb sublimes or volatilizes and deposits upon the bulb. This decreases the size of the filament eventually to the breaking-point and the blackening of the bulb decreases the output of light. The treated filament was found to be a harder form of carbon that did not volatilize as rapidly as the untreated filament. It immediately became possible to operate it at a higher temperature with a resulting increase of luminous efficiency. This "graphitized" carbon filament lamp became known as the gem lamp in this country and many persons have wondered over the word "gem." The first two letters stand for "General Electric" and the last for "metallized." This lamp was welcomed with enthusiasm in its day, but the day for carbon filaments has passed. The advent of incandescent lamps of higher efficiency has made it uneconomical to use carbon lamps for general lighting purposes. Although the treated carbon filament was a great improvement, its reign was cut short by the appearance of metal filaments. In 1803 a new element was discovered and named tantalum. It is a dark, lustrous, hard metal. Pure tantalum is harder than steel; it may be drawn into fine wire; and its melting-point is very high (about 5100°F.). It is seen to possess properties desirable for filaments, but for some reason it did not attract attention for a long time. A century elapsed after its discovery before von Bolton produced the first tantalum filament lamp. Owing to the low electrical resistance of tantalum, a filament in order to operate satisfactorily on a standard voltage must be long and thin. This necessitates storing away a considerable length of wire in the bulb without permitting the loops to come into contact with each other. After the filaments have been in operation for a few hundred hours they become brittle and faults develop. When examined under a microscope, parts of the filament operated on alternating current appear to be offset. The explanation of this defect goes deeply into crystalline structure. The tantalum filament was quickly followed by osmium and by tungsten in this country. The osmium filament appeared in 1905 and its invention is due to Welsbach, who had produced the marvelous gas-mantle. Owing to its extreme brittleness, osmium was finely divided and made into a paste of organic material. The filaments were squirted through dies and, after being formed and dried, they were heated to a high temperature. The organic matter disappeared and the fine metallic particles were sintered. This made a very brittle lamp, but its high efficiency served to introduce it. In 1870 when Scheele discovered a new element, known in this country as tungsten, no one realized that it was to revolutionize artificial lighting and to alter the course of some of the byways of civilization. This metal--which is known as "wolfram" in Germany, and to some extent in English-speaking countries--is one of the heaviest of elements, having a specific gravity of 19.1. It is 50 per cent. heavier than mercury and nearly twice as heavy as lead. It was early used in German silver to the extent of 1 or 2 per cent. to make platinoid, an alloy possessing a high resistance which varies only slightly as the temperature changes. This made an excellent material for electrical resistors. The melting-point of tungsten is about 5350°F., which makes it desirable for filaments, but it was very brittle as prepared in the early experiments. It unites very readily with oxygen and with carbon at high temperatures. The first tungsten lamps appeared on the market in 1906, but these contained fragile filaments made by the squirting process. When the squirted filament of tungsten powder and organic matter was heated in an atmosphere of steam and hydrogen to remove the binding material, a brittle filament of tungsten was obtained. The first lamps were costly and fragile. After years of organized research tungsten is now drawn into the finest wires, possessing a tensile strength perhaps greater than any other material. Filaments are now made into many shapes and the greatest strides in artificial lighting have been due to scientific research on a huge scale. The achievements which combined to perfect the tungsten lamp to the point where it has become the mainstay of electric lighting are not attached to names in the Hall of Fame. Organization of scientific research in the industrial laboratories is such that often many persons contribute to the development of an improvement. Furthermore, time is usually required for a full perspective of applications of scientific knowledge. In the early days organized research was not practised and the great developments of those days were the works of individuals. To-day, even in pure science, some of the greatest contributions are made by industrial laboratories; but sometimes these do not become known to the public for many years. The whole scheme of scientific development has changed materially. For example, the story of the development of ductile tungsten, which has revolutionized lighting, is complex and more or less shrouded in secrecy at the present time. Many men have contributed toward this accomplishment and the public at the present time knows little more than the fact that tungsten filaments, which were brittle yesterday, are now made of ductile tungsten wire drawn into the finest filaments. The earlier tungsten filaments were made by three rival processes. By the first, a deposit of tungsten was "flashed" on a fine carbon filament, the latter being eliminated finally by heating in an atmosphere of hydrogen and water-vapor. By the second, colloidal tungsten was produced by operating an arc between tungsten electrodes under water. The finely divided tungsten was gathered, partially dried, and squirted through dies to form filaments. These were then sintered. The third was the "paste" process already described. These methods produced fragile filaments, but their luminous efficiency was higher than that of previous ones. However, in this country ductile tungsten was soon on its way. An ingot of tungsten is subjected to vigorous swaging until it takes the form of a rod. This is finally drawn into wire. Much of this development work was done by the laboratories of the General Electric Company and they were destined to contribute another great improvement. The blackening of the lamp bulbs was due to the evaporation of tungsten from the filament. All filaments up to this time had been confined in evacuated bulbs and the low pressure facilitates evaporation, as is well known. It had long been known that an inert gas in the bulb would reduce the evaporation and remedy other defects; however, under these conditions, there would be a considerable loss of energy through conduction of heat by the gases. In the vacuum lamp nearly all the electrical energy is converted into radiant energy, which is emitted by the filament and any dissipation of heat is an energy loss. A high vacuum was one of the chief aims up to this time, but a radical departure was pending. If an ordinary tungsten-lamp bulb be filled with an inert gas such as nitrogen, the filament may be operated at a very much higher temperature without any more deterioration than takes place in a vacuum at a lower temperature. This gives a more efficient _light_ but a less efficient _lamp_. The greater output of light is compensated by losses by conduction of heat through the gas. In other words, a great deal more energy is required by the filament in order to remain at a given temperature in a gas than in a vacuum. However, elaborate studies of the dependence of heat-losses upon the size and shape of the filament and of the physics of conduction from a solid to a gas, established the foundation for the gas-filled tungsten lamp. The knowledge gained in these investigations indicated that a thicker filament lost a relatively less percentage of energy by conduction than a thin one for equal amounts of emitted light. However, a practical filament must have sufficient resistance to be used safely on lighting circuits already established and, therefore, the large diameter and high resistance were obtained by making a helical coil of a fine wire. In fact, the gas-filled tungsten lamp may be thought of as an ordinary lamp with its long filament made into a short helical coil and the bulb filled with nitrogen or argon gas. This development was not accidental and from a scientific point of view it is not spectacular. It did not mark a new discovery in the same sense as the discovery of X-rays. However, it is an excellent example of the great rewards which come to systematic, thorough study of rather commonplace physical laws in respect to a given condition. Such achievements are being duplicated in various lines in the laboratories of the industries. Scientific research is no longer monopolized by educational institutions. The most elaborate and best-equipped laboratories are to be found in the industries sometimes surrounded by the smoke and noise and vigorous activity which indicate that achievements of the laboratory are on their way to mankind. The smoke-laden industrial district, pulsating with life, is the proud exhibit of the present civilization. It is the creation of those who discover, organize, and apply scientific facts. But how many appreciate the debt that mankind owes not only to the individual who dedicates his life to science but to the far-sighted manufacturer who risks his money in organized quest of new benefits for mankind? A glimpse into a vast organization of research, which, for example, has been mainly responsible for the progress of the incandescent lamp would alter the attitude of many persons toward science and toward the large industrial companies. The progress in the development of electric incandescent lamps is shown in the following table, where the dates and values are more or less approximate. It should be understood that from 1880 to the present time there has been a steady progress, which occasionally has been greatly augmented by sudden steps. APPROXIMATE VALUES Lumens per Date Filament Temperature watt 1880 Carbon 3300°F. 3.0 1906 Carbon (graphitized) 3400 4.5 1905 Tantalum 3550 6.5 1905 Osmium 3600 7.5 1906 Tungsten (vacuum) 3700 8.0 1914 Tungsten (gas-filled) up to 5300°F. 10 to 25 Throughout the development of incandescent filament lamps many ingenious experiments were made which resulted usually in light-sources of scientific interest but not of practical value. One of the latest is the tungsten arc in an inert gas. By means of a heating coil, a small arc is started between two electrodes consisting of tungsten, but this as yet has not been shown to be practicable. Another type of filament lamp was developed by Nernst in 1897. It was an ingenious application of the peculiar properties of rare-earth oxides. His first lamp consisted essentially of a slender rod of magnesia. This substance does not conduct electricity at ordinary temperatures, but when heated to incandescence it becomes conducting. Upon sufficient heating of this filament by external means while a proper voltage is impressed upon it, the electric current passes through it and thereafter this current will maintain its temperature. Thus such a filament becomes a conductor and will continue to glow brilliantly by virtue of the electrical energy which it converts into heat. Later lamps consisted of "glowers" about one inch long made from a mixture of zirconia and yttria, and finally a mixture of ceria, thoria, and zirconia was used. The glower is heated initially by a coil of platinum wire located near it but not in contact with it. Owing to the fact that this glower decreases rapidly in resistance as its temperature is increased, it is necessary to place in series with it a substance which increases in resistance with increasing current. This is called a "ballasting resistance" and is usually an iron wire in a glass bulb containing hydrogen. The heater is cut out by an electromagnet when the glower goes into operation. This lamp is a marvel of ingenuity and when at its zenith it was installed to a considerable extent. Its light is considerably whiter than that of the carbon filament lamps. However, its doom was sounded when metallic filament lamps appeared. An interesting filament was developed by Parker and Clark by using as a core a small filament of carbon. This flashed in an atmosphere containing a vapor of a compound of silicon, became coated with silicon. This filament was of high specific resistance and appeared to have promise. It has not been introduced commercially and doubtless it cannot compete with the latest tungsten lamps. Electric incandescent lamps are the present mainstay of electric illumination and, it might be stated, of progress in lighting. Wonderful achievements have been accomplished in other modes of lighting and the foregoing statement is not meant to depreciate those achievements. However, the incandescent filament lamp has many inherent advantages. The light-source is enclosed in an air-tight bulb which makes for a safe, convenient lamp. The filament is capable of subdivision, with the result that such lamps vary from the minutest spark of the smallest miniature lamp to the enormous output of the largest gas-filled tungsten lamp. The outputs of these are respectively a fraction of a lumen and twenty-five thousand lumens; that is, the luminous intensity varies from an equivalent of a small fraction of a standard candle to a single light-source emitting light equivalent to two thousand standard candles. Statistics are cold facts and are usually uninteresting in a volume of this character, but they tell a story in a concise manner. The development of the modern incandescent lamp has increased the intensity of light available with a great decrease in cost, and this progressive development is shown easily by tables. For example, since the advent of the tungsten lamp the average candle-power and luminous efficiency of all the lamps sold in this country has steadily increased, while the average wattages of the lamps have remained virtually stationary. AVERAGE CANDLE-POWER, WATTS, AND EFFICIENCY OF ALL THE LAMPS SOLD IN THIS COUNTRY Lumens Year Candle-power Watts per watt 1907 18.0 53 3.33 1908 19.0 53 3.52 1909 21.0 52 3.96 1910 23.0 51 4.42 1911 25.0 51 4.82 1912 26.0 49 5.20 1913 29.4 47 6.13 1914 38.2 48 7.80 1915 42.2 47 8.74 1916 45.8 49 9.60 1917 48.7 51 10.56 It will be noted that the luminous intensity of incandescent filament lamps has steadily increased since the carbon lamp was superseded, and that in a period of ten years of organized research behind the tungsten lamp the luminous efficiency (lumens per watt) has trebled. In other words, everything else remaining unchanged, the cost of light in ten years was reduced to one third. But the reduction in cost has been more than this, as will be shown later. During the same span of years the percentage of carbon filament lamps of the total filament lamps sold decreased from 100 per cent. in 1907 to 13 per cent. in 1917. At the same time the percentage of tungsten (Mazda) lamps increased from virtually zero in 1907 to about 87 per cent. in 1917. The tantalum lamp had no opportunity to become established, because the tungsten lamp followed its appearance very closely. In 1910 the sales of the former reached their highest mark, which was only 3.5 per cent. of all the lamps sold in the United States. From a lowly beginning the number of incandescent filament lamps sold for use in this country has grown rapidly, reaching nearly two hundred million in 1919. XI THE LIGHT OF THE FUTURE In viewing the development of artificial light and its manifold effects upon the activities of mankind, it is natural to look into the future. Jules Verne possessed the advantage of being able to write into fiction what his riotous imagination dictated, and so much of what he pictured has come true that his success tempts one to do likewise in prophesying the future of lighting. Surely a forecast based alone upon the past achievements and the present indications will fall short of the actual realizations of the future! If the imagination is permitted to view the future without restrictions, many apparently far-fetched schemes may be devised. It may be possible to turn to nature's supply of daylight and to place some of it in storage for night use. One millionth part of daylight released as desired at night would illuminate sufficiently all of man's nocturnal activities. The fictionist need not heed the scientist's inquiry as to how this daylight would be bottled. Instead of giving time to such inquiries he would pass on to another scheme, whereby earth would be belted with optical devices so that day could never leave. When the sun was shining in China its light would be gathered on a large scale and sent eastward and westward in these great optical "pipe-lines" to the regions of darkness, thus banishing night forever. The writer of fiction need not bother with a consideration of the economic situation which would demand such efforts. This line of conjecture is interesting, for it may suggest possibilities toward which the present trend of artificial lighting does not point; however, the author is constrained to treat the future of light-production on a somewhat more conservative basis. At the present time the light-source of chief interest in electric lighting is the incandescent filament lamp; but its luminous efficiency is limited, as has been shown in a previous chapter. When light is emitted by virtue of its temperature much invisible radiant energy accompanies the visible energy. The highest luminous efficiency attainable by pure temperature radiation will be reached when the temperature of a normal radiator reaches the vicinity of 10,000°F. to 11,000°F. The melting-points of metals are much lower than this. The tungsten filament in the most efficient lamps employing it is operating near its melting-point at the present time. Carbon is a most attractive element in respect to melting-point, for it melts at a temperature between 6000°F. and 7000°F. Even this is far below the most efficient temperature for the production of light by means of pure temperature radiation. There are possibilities of higher efficiency being obtained by operating arcs or filaments under pressure; however, it appears that highly efficient light of the future will result from a radical departure. Scientists are becoming more and more intimate with the structure of matter. They are learning secrets every year which apparently are leading to a fundamental knowledge of the subject. When these mysteries are solved, who can say that man will not be able to create elements to suit his needs, or at least to alter the properties of the elements already available? If he could so alter the mechanism of radiation that a hot metal would radiate no invisible energy, he would have made a tremendous stride even in the production of light by virtue of high temperature. This property of selective radiation is possessed by some elements to a slight degree, but if treatment could enhance this property, luminous efficiency would be greatly increased. Certainly the principle of selectivity is a byway of possibilities. A careful study of commonplace factors may result in a great step in light-production without the creation of new elements or compounds, just as such a procedure doubled the luminous efficiency of the tungsten filament when the gas-filled lamp appeared. There are a few elements still missing, according to the Periodic Law which has been so valuable in chemistry. When these turn up, they may be found to possess valuable properties for light-production; but this is a discouraging byway. It is natural to inquire whether or not any mode of light-production now in use has a limiting luminous efficiency approaching the ultimate limit which is imposed by the visibility of radiation. The eye is able to convert radiant energy of different wave-lengths into certain fixed proportions of light. For example, radiant energy of such a wave-length as to excite the sensation of yellow-green is the most efficient and one watt of this energy is capable of being converted by the visual apparatus into about 625 lumens of light. Is this efficiency of conversion of the visual apparatus everlastingly fixed? For the answer it is necessary to turn to the physiologist, and doubtless he would suggest the curbing of the imagination. But is it unthinkable that the visual processes will always be beyond the control of man? However, to turn again to the physics of light-production, there are still several processes of producing light which are appealing. Many years ago Geissler, Crookes, and other scientists studied the spectra of gases excited to incandescence by the electric discharge in so-called vacuum tubes. The gases are placed in transparent glass or quartz tubes at rather low pressures and a high voltage is impressed upon the ends of these tubes. When the pressure is sufficiently low, the gases will glow and emit light. Twenty-eight years ago, D. McFarlan Moore developed the nitrogen tube, which was actually installed in various places. But there is such a loss of energy near the cathode that short "vacuum" tubes of this character are very inefficient producers of light. Efficiency is greatly increased by lengthening the tubes, so Moore used tubes of great length and a rather high voltage. As a tube of this sort is used, the gas gradually disappears and it must be replenished. In order to replenish the gas, Moore devised a valve for feeding gas automatically. An advantage of this mode of light-production is that the color or quality of the light may be varied by varying the gas used. Nitrogen yields a pinkish light; neon an orange light; and carbon dioxide a white light. Moore's carbon-dioxide tube is an excellent substitute for daylight and has been used for the discrimination of colors where this is an important factor. However, for this purpose devices utilizing color-screens which alter the light from the tungsten lamp to a daylight quality are being used extensively. The vacuum-tube method of producing light has an advantage in the selection of a gas among a large number of possibilities, and some of the color effects of the future may be obtained by means of it. Claude has lately worked on light-production by vacuum tubes and has combined the neon tube with the mercury-vapor tube. The spectrum of neon to a large extent compensates for the absence of red light in the mercury spectrum, with a result that the mixture produces a more satisfactory light than that of either tube. However, this mode of light-production has not proved practicable in its present state of development. Fundamentally the limitations are those of the inherent spectral characteristics of gases. Doubtless the possibilities of the mechanisms of the tubes and of combining various gases have not been exhausted. Furthermore, if man ever becomes capable of controlling to some extent the structure of elements and of compounds, this method of light-production is perhaps more promising than others of the present day. There is another attractive method of producing light and it has not escaped the writer of fiction. H. G. Wells, with his rare skill and with the license so often envied by the writer of facts, has drawn upon the characteristics of fluorescence and phosphorescence. In his story "The First Men in the Moon," the inhabitants of the moon illuminate their caverns by utilizing this phenomenon. A fluorescent liquid was prepared in large quantities. It emitted a brilliant phosphorescent glow and when it splashed on the feet of the earth-men it felt cold, but it glowed for a long time. This is a possibility of the future and many have had visions of such lighting. If the ceiling of a coal-mine was lined with glowing fireflies or with phosphorescent material excited in some manner, it would be possible to see fairly well with the dark-adapted eyes. This leads to the class of phenomena included under the general term "luminescence." The definition of this term is not thoroughly agreed upon, but light produced in this manner does not depend upon temperature in the sense that a glowing tungsten filament emits light because it is sufficiently hot. A phosphorus match rubbed in the moist palm of the hand is seen to glow, although it is at an ordinary temperature. This may be termed "chemi-luminescence." Sidot blende, Balmain's paint, and many other compounds, when illuminated with ordinary light, and especially with ultra-violet and violet rays, will continue to glow for a long time. Despite their brightness they will be cold to the touch. This phenomenon would be termed "photo-luminescence," although it is better known as "phosphorescence." It should be noted that the latter term was carelessly originated, for phosphorus has nothing to do with it. The glow of the Geissler tube or electrically excited gas at low pressure would be an example of "electro-luminescence." The luminosity of various salts in the Bunsen-flame is due to so-called luminescence and there are many other examples of light-production which are included in the same general class. Inasmuch as light is emitted from comparatively cold bodies in these cases, it is popularly known as "cold" light. There are many instances of light being emitted without being accompanied by appreciable amounts of invisible radiant energy and it is natural to hope for practical possibilities in this direction. As yet little is known regarding the efficiency of light-production by phosphorescence. The luminous efficiency of the radiant energy emitted by phosphorescent substances has been studied, but it seems strange that among the vast works on phosphorescent phenomena, scarcely any mention is made of the efficiency of producing light in this manner. For example, assume that phosphorescent zinc sulphide is excited by the light from a mercury-arc. All the energy falling upon it is not capable of exciting phosphorescence, as may be readily shown. Assuming that a known amount of radiant energy of a certain wave-length has been permitted to fall upon the phosphorescent material, then in the dark the latter may be seen to glow for a long time. An interesting point to investigate is the relation of the output to input; that is, the ratio of the total emitted light to the total exciting energy. This is a neglected aspect in the study of light-production by this means. The firefly has been praised far and wide as the ideal light-source. It is an efficient radiator of light, for its light is "cold"; that is, it does not appear to be accompanied by invisible radiant energy. But little is said about its efficiency as a light-producer. Who knows how much fuel its lighting-plant consumes? The chemistry of light-production by living organisms is being unraveled and this part of the phenomenon will likely be laid bare before long. For an equal amount of energy radiated, the firefly emits a great many times more light than the most efficient lamp in use at the present time, but before the firefly is pronounced ideal, the efficiency of its light-producing process must be known. There are many ways of exciting phosphorescence and fluorescence, the latter being merely an unenduring phosphorescence, which ceases when the exciting energy is cut off. Ultra-violet, violet, and blue rays are generally the most effective radiant energy for excitation purposes. X-rays and the high-frequency discharge are also powerful excitants. As already stated, virtually nothing is known of the efficiency of this mode of light-production or of the mechanism within the substance, but on the whole it is a remarkable phenomenon. Radium is also a possibility in light-production and in fact has been practically employed for this purpose for several years. It or one of its compounds is mixed with a phosphorescent substance such as zinc sulphide and the latter glows continuously. Inasmuch as the life of some of the radium products is very long, such a method of illuminating watch-dials, scales of instruments, etc., is very practicable where they are to be read by eyes adapted to darkness and consequently highly sensitive to light. Whether or not radium will be manufactured by the ton in the future can only conjectured. Owing to the limitations imposed by physical laws of radiation and by the physiological processes of vision the highest luminous efficiency obtainable by heating solid materials is only about 15 per cent. of the luminous efficiency of the most luminous radiant energy. At present there are no materials available which may be operated at the temperature necessary to reach even this efficiency. Great progress in the future of light-production as indicated by present knowledge appears to lie in the production of light which is unaccompanied by invisible radiant energy. At present such phenomena as fluorescence, phosphorescence, the light of the firefly, chemi-luminescence, etc., are examples of this kind of light-production. Of course, if science ever obtains control over the constitution of matter, many difficulties will disappear; for then man will not be dependent upon the elements and compounds now available but will be able to modify them to suit his needs. XII LIGHTING THE STREETS In this age of brilliantly lighted boulevards and "great white ways" flooded with light from shop-windows, electric signs, and street-lamps, it is difficult to visualize the gloom which shrouded the streets a century ago. As the belated pedestrian walks along the suburban highways in comparative safety under adequate artificial lighting, he will realize the great influence of artificial light upon civilization if he recalls that not more than two centuries ago in London it was a common practice ... that a hundred or more in a company, young and old, would make nightly invasions upon houses of the wealthy to the intent to rob them and that when night was come no man durst adventure to walk in the streets. Inhabitants of the cities of the present time are inclined to think that crime is common on the streets at night, but what would it be without adequate artificial light? Two centuries ago in a city like London a smoking grease-lamp, a candle, or a basket of pine knots here and there afforded the only street-lighting, and these were extinguished by eleven o'clock. Lawlessness was hatched and hidden by darkness, and even the lantern or torch served more to mark the victim than to protect him. It has been said in describing the conditions of the age of dark streets that everybody signed his will and was prepared for death before he left his home. By comparison with the present, one is again encouraged to believe that the world grows better. Doubtless, artificial light projected into the crannies has had something to do with this change. Adequate street-lighting is really a product of the twentieth century, but throughout the nineteenth century progress was steadily made from the beginning of gas-lighting in 1807. In preceding centuries crude lighting was employed here and there but not generally by the public authorities. In the earliest centuries of written history little is said of street-lighting. In those days man was not so much inclined to improve upon nature, beyond protecting himself from the elements, and he lighted the streets more as a festive outburst than as an economic proposition. Nevertheless, in the early writings occasionally there are indications that in the centers of advanced civilization some efforts were made to light the streets. The old Syrian city of Antioch, which in the fourth century of the Christian era contained about four hundred thousand inhabitants, appears to have had lighted streets. Libanius, who lived in the early years of that century, wrote: The light of the sun is succeeded by other lights, which are far superior to the lamps lighted by Egyptians on the festival of Minerva of Sais. The night with us differs from the day only in the appearance of the light; with regard to labor and employment, everything goes on well. Although apparently labor was not on a strike, the soldiers caused disturbances, for in another passage he tells of riotous soldiers who cut with their swords the ropes from which were suspended the lamps that afforded light in the night-time, to show that the ornaments of the city ought to give way to them. Another writer in describing a dispute between two religious adherents of opposed creeds stated that they quarreled "till the streets were lighted" and the crowd of onlookers broke up, but not until they "spat in each other's face and retired." Thus it is seen that artificial light and civilization may advance, even though some human traits remain fundamentally unchanged. Throughout the next thousand years there was little attempt to light the streets. Iron baskets of burning wood, primitive oil-lamps, and candles were used to some extent, but during all these centuries there was no attempt on the part of the government or of individuals to light the streets in an organized manner. In 1417 the Mayor of London ordained "lanthorns with lights to bee hanged out on the winter evenings betwixt Hallowtide and Candlemasse." This was during the festive season, so perhaps street-lighting was not the sole aim. Early in the sixteenth century, the streets of Paris being infested with robbers, the inhabitants were ordered to keep lights burning in the windows of all houses that fronted on the streets. For about three centuries the citizens of London, and doubtless of Paris and of other cities, were reminded from time to time in official mandates "on pains and penalties to hang out their lanthorns at the appointed time." The watchman in long coat with halberd and lantern in hand supplemented these mandates as he made his rounds by, A light here, maids, hang out your lights, And see your horns be clear and bright, That so your candle clear may shine, Continuing from six till nine; That honest men that walk along May see to pass safe without wrong. In 1668, when some regulations were made for improving the streets of London, the inhabitants were ordered "for the safety and peace of the city to hang out candles duly to the accustomed hour." Apparently this method of obtaining lighting for the streets was not met by the enthusiastic support of the people, for during the next few decades the Lord Mayor was busy issuing threats and commands. In 1679 he proclaimed the "neglect of the inhabitants of this city in hanging and keeping out their lights at the accustomed hours, according to the good and ancient usage of this City and Acts of the Common Council on that behalf." The result of this neglect was "when nights darkened the streets then wandered forth the sons of Belial, flown with insolence and wine." In 1694 Hemig patented a reflector which partially surrounded the open flame of a whale-oil lamp and possessed a hole in the top which aided ventilation. He obtained the exclusive rights of lighting London for a period of years and undertook to place a light before every tenth door, between the hours of six and twelve o'clock, from Michaelmas to Lady Day. His effort was a worthy one, but he was opposed by a certain faction, which was successful in obtaining a withdrawal of his license in 1716. Again the burden of lighting the streets was thrust upon the residents and fines were imposed for negligence in this respect. But this procedure after a few more years of desultory lighting was again found to be unsatisfactory. In 1729 certain individuals contracted to light the streets of London by taxing the residents and paid the city for this monopoly. Householders were permitted to hang out a lantern or a candle or to pay the company for doing so. But robberies increased so rapidly that in 1736 the Lord Mayor and Common Council petitioned Parliament to erect lamps for lighting the city. An act was passed accordingly, giving them the privilege to erect lamps where they saw fit and to burn them from sunset to sunrise. A charge was made to the residents, on a sliding scale depending upon the rate of rental of the houses. As a consequence five thousand lamps were soon installed. In 1738 there were fifteen thousand street lamps in London and they were burned an average of five thousand hours annually. In the annals of these early times street-lighting is almost invariably the result of an attempt to reduce the number of robberies and other crimes. In appealing for more street-lamps in 1744 the Lord Mayor and aldermen of London in a petition to the king, stated that divers confederacies of great numbers of evil-disposed persons, armed with bludgeons, pistols, cutlasses, and other dangerous weapons, infest not only the private lanes and passages, but likewise the public streets and places of public concourse, and commit most daring outrages upon the persons of your Majesty's good subjects, whose affairs oblige them to pass through the streets, by terrifying, robbing and wounding them; and these facts are frequently perpetrated at such times as were heretofore deemed hours of security. It has already been seen that gas-lighting was introduced in the streets of London for the first time in 1807. This marks the real beginning of public-service lighting companies. In the next decade interest in street-lighting by means of gas was awakened on the Continent, and it was not long before this new phase of civilization was well under way. Although this first gas-lighting was done by the use of open flames, it was a great improvement over all the preceding efforts. Lawlessness did not disappear entirely, of course, and perhaps it never will, but it skulked in the back streets. A controlling influence had now appeared. But early innovations in lighting did not escape criticism and opposition. In fact, innovations to-day are not always received by unanimous consent. There were many in those early days who felt that what was good for them should be good enough for the younger generation. The descendants of these opponents are present to-day but fortunately in diminishing numbers. It has been shown that in Philadelphia in 1833 a proposal to install a gas-plant was met with a protest signed by many prominent citizens. A few paragraphs of an article entitled "Arguments against Light" which appeared in the Cologne _Zeitung_ in 1816 indicate the character of the objections raised against street-lighting. 1 From the theological standpoint: Artificial illumination is an attempt to interfere with the divine plan of the world, which has preordained darkness during the night-time. 2 From the judicial standpoint: Those people who do not want light ought not to be compelled to pay for its use. 3 From the medical standpoint: The emanations of illuminating gas are injurious. Moreover, illuminated streets would induce people to remain later out of doors, leading to an increase in ailments caused by colds. 4 From the moral standpoint: The fear of darkness will vanish and drunkenness and depravity increase. 5 From the viewpoint of the police: The horses will get frightened and the thieves emboldened. 6 From the point of view of national economy: Great sums of money will be exported to foreign countries. 7 From the point of view of the common people: The constant illumination of streets by night will rob festive illuminations of their charm. The foregoing objections require no comment, for they speak volumes pertaining to the thoughts and activities of men a century ago. It is difficult to believe that civilization has traveled so far in a single century, but from this early beginning of street-lighting social progress received a great impetus. Artificial light-sources were feeble at that time, but they made the streets safer and by means of them social intercourse was extended. The people increased their hours of activity and commerce, industry, and knowledge grew apace. The open gas-jet and kerosene-flame lamps held forth on the streets until within the memory of middle-aged persons of to-day. The lamplighter with his ladder is still fresh in memory. Many of the towns and villages have never been lighted by gas, for they stepped from the oil-lamp to the electric lamp. The gas-mantle has made it possible for gas-lighting to continue as a competitor of electric-lighting for the streets. In 1877 Mr. Brush illuminated the Public Square of Cleveland with a number of arc-lamps, and these met with such success that within a short time two hundred and fifty thousand open-arc lamps were installed in this country, involving an investment of millions of dollars. Adding to this investment a much greater one in central-station equipment, a very large investment is seen to have resulted from this single development in lighting. This open-arc lamp was the first powerful light-source available and, appearing several years before the gas-mantle, it threatened to monopolize street-lighting. It consumed about 500 watts and had a maximum luminous intensity of about 1200 candles at an angle of about 45 degrees. Its chief disadvantage was its distribution of light, mainly at this angle of 45 degrees, which resulted in a spot of light near the lamp and little light at a distance. A satisfactory street-lighting unit must emit its light chiefly just below the horizontal in those cases where the lamps must be spaced far apart for economical reasons. On referring to the chapter on the electric arc it will be seen that the upper (positive) carbon of the open-arc emits most of the light. Thus most of the light tends to be sent downward, but the lower carbon obstructs some of this with a resulting dark spot beneath the lamp. The gas-mantle followed closely after the arrival of the carbon arc and is responsible for the existence of gas-lighting on the streets at the present time. It is a large source of light and therefore its light cannot be controlled by modern accessories as well as the light from smaller sources, such as the arc or concentrated-filament lamp. As a consequence, there is marked unevenness of illumination along the streets unless the gas-mantle units are spaced rather closely. Even with the open-arc, without special light-controlling equipment there is about a thousand times the intensity near the lamps when placed on the corners of the block as there is midway between them. In 1879 the incandescent filament lamp was introduced and it began to appear on the streets in a short time. It was a feeble, inefficient light-source, compared with the arc-lamp, but it had the advantage of being installed on a small bracket. As a consequence of simplicity of operation, the incandescent lamp was installed to a considerable extent, especially in the suburban districts. [Illustration: THE MOORE NITROGEN TUBE In lobby of Madison Square Garden] [Illustration: CARBON-DIOXIDE TUBE FOR ACCURATE COLOR-MATCHING] [Illustration: MODERN STREET LIGHTING Tunnels of light boring through the darkness provide safe channels for modern traffic] The open-arc lamp possessed the disadvantage of emitting a very unsteady light and of consuming the carbons so rapidly that daily trimming was often necessary. In 1893 the enclosed arc appeared and although it consumed as much electrical energy as the open-arc and emitted considerably less light, it possessed the great advantage of operating a week without requiring a renewal of carbons. By surrounding the arc by means of a glass globe, little oxygen could come in contact with the carbons and they were not consumed very rapidly. The light was fairly steady and these arcs operated satisfactorily on alternating current. The latter feature simplified the generating and distributing equipment of the central station. The magnetite or luminous arc-lamp next appeared and met with considerable success. It was more efficient than the preceding lamps but was handicapped by being solely a direct-current device. Those familiar with the generation and distribution of electricity will realize this disadvantage. However, its luminous intensity just below the horizontal was about 700 candles and its general distribution of light was fairly satisfactory. Later the flame-arcs began to appear and they were installed to some extent. The arc-lamp has served well in street-lighting from the year 1877, when the open-arc was introduced, until the present time, when the luminous-arc is the chief survivor of all the arc-lamps. The carbon incandescent filament lamp was used extensively until 1909, when the tungsten filament lamp began to replace it very rapidly. However, it was not until 1914, when the gas-filled tungsten lamp appeared, that this type of light-source could compete with arc-lamps on the basis of efficiency. The helical construction of the filament made it possible to confine the filament of a high-intensity tungsten lamp in a small space and for the first time a high degree of control of the light of street lamps was possible. Prismatic "refractors" were designed, somewhat on the principle of the lighthouse refractor, so that the light would be emitted largely just below the horizontal. This type of distribution builds up the illumination at distant points between successive street lamps, which is very desirable in street-lighting. The incandescent filament lamp possesses many advantages over other systems. It is efficient; capable of subdivision; operates on direct and alternating current; requires little attention; and is capable of most successful use with light-controlling apparatus. According to the reports of the Department of Commerce the number of electric arc-lamps for street-lighting supplied by public electric-light plants decreased from 348,643 in 1912 to 256,838 in 1917, while the number of electric incandescent filament lamps increased from 681,957 in 1912 to 1,389,382 in 1917. Street-lighting is not only a reinforcement for the police but it decreases accidents and has come to be looked upon as an advertising medium. In the downtown districts the high-intensity "white-way" lighting is festive. The ornamental street lamps have possibilities in making the streets attractive and in illuminating the buildings. However, it is to be hoped that in the present age the streets of cities and towns will be cleared of the ragged equipment of the telephone and lighting companies. These may be placed in the alleys or underground, leaving the streets beautiful by day and glorified at night by the torches of advanced civilization. XIII LIGHTHOUSES At the present time thousands of lighthouses, light-ships, and light-buoys guide the navigator along the waterways and into harbors and warn him of dangerous shoals. Many wonderful feats of engineering are involved in their construction and in no field of artificial lighting has more ingenuity been displayed in devising powerful beams of light. Many of these beacons of safety are automatic in operation and require little attention. It has been said that nothing indicates the liberality, prosperity, or intelligence of a nation more clearly than the facilities which it affords for the safe approach of the mariner to its shores. Surely these marine lights are important factors in modern navigation. The first "lighthouses" were beacon-fires of burning wood maintained by priests for the benefit of the early commerce in the eastern part of the Mediterranean Sea. As early as the seventh century before Christ these beacon-fires were mentioned in writings. In the third century before the Christian era a tower said to be of a great height was built on a small island near Alexandria during the reign of Ptolemy II. The tower was named Pharos, which is the origin of the term "pharology" applied to the science of lighthouse construction. Cæsar, who visited Alexandria two centuries later, described the Pharos as a "tower of great height, of wonderful construction." Fire was kept burning in it night and day and Pliny said of it, "During the night it appears as bright as a star, and during the day it is distinguished by the smoke." Apparently this tower served as a lighthouse for more than a thousand years. It was found in ruins in 1349. Throughout succeeding centuries many towers were built, but little attention was given to the development of light-sources and optical apparatus. The first lighthouse in the United States and perhaps on the Western continents was the Boston Light, which was completed in 1716. A few days after it was put into operation a news item in a Boston paper heralded the noteworthy event as follows: By virtue of an Act of Assembly made in the First Year of His Majesty's Reign, For Building and Maintaining a Light House upon the Great Brewster (called Beacon-Island) at the Entrance of the Harbour of Boston, in order to prevent the loss of the Lives and Estates of His Majesty's Subjects; the said Light House has been built; and on Fryday last the 14th Currant the Light was kindled, which will be very useful for all Vessels going out and coming in to the Harbour of Boston, or any other Harbours in the Massachusetts Bay, for which all Masters shall pay to the Receiver of Impost, one Penny per Ton Inwards, and another Penny Outwards, except Coasters, who are to pay Two Shillings each, at their clearance Out, And all Fishing Vessels, Wood Sloops, etc. Five Shillings each by the Year. This was the practical result of a petition of Boston merchants made three years before. The tower was built of stone, at a cost of about ten thousand dollars. Two years later the keeper and his family were drowned and the catastrophe so affected Benjamin Franklin, a boy of thirteen, that he wrote a poem concerning it. The lighthouse was badly damaged during the Revolution, by raiding-parties, and in 1776, when the British fleet left the harbor, a squad of sailors blew it up. It was rebuilt in 1783 and has since been increased in height. Apparently oil-lamps were used in it from the beginning, notwithstanding the fact that candles and coal fires served for years in many lighthouses of Europe. In 1789 sixteen lamps were used and in 1811 Argand lamps and reflectors were installed, with a revolving mechanism. It now ceased to be a fixed light and the day of flashing lights had arrived. At the present time the Boston Light emits a beam of 100,000 candle-power directed by modern lenses. When the United States Government was organized in 1789 there were ten lighthouses owned by the Colonies, but the Boston Light was in operation thirty years before the others. Sandy Hook Light, New York Harbor, was established in 1764 and its original masonry tower is still standing and in use. It is the oldest surviving lighthouse in this country. It was built with funds raised by means of two lotteries authorized by the New York Assembly. A few days after it was lighted for the first time the following news item appeared in a New York paper: On Monday evening last the New York Light-house erected at Sandy Hook was lighted for the first time. The House is of an Octagon Figure, having eight equal Sides; the Diameter at the Base 29 Feet; and at the top of the Wall, 15 Feet. The Lanthorn is 7 feet high; the Circumference 33 feet. The whole Construction of the Lanthorn is Iron; the Top covered with Copper. There are 48 Oil Blazes. The Building from the Surface is Nine Stories; the whole from Bottom to Top is 103 Feet. From these early years the number of lighthouses has steadily grown, until now the United States maintains lights along 50,000 miles of coast-line and river channels, a distance equal to twice the circumference of the earth. It maintains at the present time about 15,000 aids to navigation at an annual cost of about $5,000,000. In 1916 this country was operating 1706 major lights, 53 light-ships, and 512 light-buoys--a total of 5323. The earliest lighthouses were equipped with braziers or grates in which coal or wood was burned. These crude light-sources were used until after the advent of the nineteenth century and in one case until 1846. In the famous Eddystone tower off Plymouth, England, candles were used for the first time. The first Eddystone tower was completed in 1698, but it was swept away in 1703. Another was built and destroyed by fire in 1755. Smeaton then built another in 1759. Inasmuch as Smeaton is credited with having introduced the use of candles, this must have occurred in the eighteenth century; still it appears that, as we have said, the Boston Light, built in 1716, used oil-lamps from its beginning. However, Smeaton installed twenty-four candles of rather large size each credited with an intensity of 2.8 candles. The total luminous intensity of the light-source in this tower was about 67 candles. Inasmuch as this was before the use of efficient reflectors and lenses, it is obvious that the early lighthouses were rather feeble beacons. According to British records, oil-lamps with flat wicks were first used in the Liverpool lighthouses in 1763. The Argand lamp, introduced in about 1784, became widely used. The better combustion obtained with this lamp having a cylindrical wick and a glass chimney greatly increased the luminous intensity and general satisfactoriness of the oil-lamp. Later Lange added an improvement by providing a contraction toward the upper part of the chimney. Rumford and also Fresnel devised multiple-wick burners, thus increasing the luminous intensity. In these early lamps sperm-oil and colza-oil were burned and they continued to be until the middle of the nineteenth century. Cocoanut-oil, lard-oil, and olive-oil have also been used in lighthouses. Naturally, mineral oil was introduced as soon as it was available, owing to its lower cost; but it was not until nearly 1870 that a satisfactory mineral-oil lamp was in operation in lighthouses. Doty is credited with the invention of the first successful multiple-wick lighthouse lamp using mineral oil, and his lamp and modifications of it were very generally used until the latter part of the nineteenth century. These lamps are of two types--one in which oil is supplied to the burner under pressure and the other in which oil is maintained at a constant level. In some of the smallest lamps the ordinary capillarity of the wick is depended on to supply oil to the flame. Coal-gas was introduced into lighthouses in about the middle of the nineteenth century. Inasmuch as the gas-mantle had not yet appeared, the gas was burned in jets. Various arrangements of the jets, such as concentric rings forming a stepped cone, were devised. The gas-mantle was a great boon to the mariner as well as to civilized beings in general. It greatly increases the intensity of light obtainable from a given amount of fuel and it is a fairly compact bright source which makes it possible to direct the light to some degree by means of optical systems. Owing to the elaborate apparatus necessary for making coal-gas, several other gases have been more desirable fuels for lighthouse lamps. Various simple gas-generators have been devised. Some of the high-flash mineral-oils are vaporized and burned under a mantle. Acetylene, which is so simply made by means of calcium carbide and water, has been a great factor in lighting for navigation. By the latter part of the nineteenth century lighthouses employing incandescent gas-burners were emitting beams of light having luminous intensities as great as several hundred thousand candles. These special gas-mantle light-sources have brightness as high as several hundred candles per square inch. Electric arc-lamps were first introduced into lighthouse service in about 1860, but these lamps cannot be considered to have been really practicable until about 1875. In 1883 the British lighthouse authorities carried out an extensive investigation of arc-lamps. It was found that the whiter light from these lamps suffered a greater absorption by the atmosphere than the yellower light from oils, but the much greater luminous intensity of the arc-lamp more than compensated for this disadvantage. The final result of the investigation was the conclusion that for ordinary lighthouse purposes the oil-and gas-lamps were more suitable and economical than arc-lamps; but where great range was desired, the latter were much more advantageous, owing to their great luminous intensity. Electric incandescent filament lamps have been used for the less important lights, and recently there has been some application of the modern high-efficiency filament lamps. Besides the high towers there are many minor beacons, light-ships, and light-buoys in use. Many of these are untended and therefore must operate automatically. The light-ship is used where it is impracticable or too expensive to build a lighthouse. Inasmuch as it is anchored in fairly deep water, it is safe in foggy weather to steer almost directly toward its position as indicated by the fog-signal. Light-ships are more expensive to maintain than lighthouses, but they have the advantages of smaller cost and of mobility; for sometimes it may be desired to move them. The first light-ship was established in 1732 near the mouth of the Thames, and the first in this country was anchored in Chesapeake Bay near Norfolk in 1820. The early ships had no mode of self-propulsion, but the modern ones are being provided with their own power. Oil and gas have been used as fuel for the light-sources and in 1892 the U. S. Lighthouse Board constructed a light-ship with a powerful electric light. Since that time several have been equipped with electric lights supplied by electric generators and batteries. Untended lights were not developed until about 1880, when Pintsch introduced his welded buoys filled with compressed gas and thereby provided a complete lighting-plant. With improvements in lamps and controls the untended light-buoys became a success. The lights burn for several months, and even for a year continuously; and the oil-gas used appears to be very satisfactory. Recently some experiments have been made with devices which would be actuated by sunlight in such a manner that the light would be extinguished during the day excepting a small pilot-flame. By this means a longer period of burning without attention may be obtained. Electric filament lamps supplied by batteries or by cables from the shore have been used, but the oil-gas buoy still remains in favor. Acetylene has been employed as a fuel for light-buoys. Automatic generators have been devised, but the high-pressure system is more simple. In the latter case purified acetylene is held in solution under high pressure in a reservoir containing an asbestos composition saturated with acetone. The light-sources of beacons have had the same history as those of other navigation lights. Many of these are automatic in operation, sometimes being controlled by clockwork. During the last twenty years the gas-mantle has been very generally applied to beacon-lights. In the latter part of the nineteenth century a mineral-oil lamp was devised with a permanent wick made by forming upon a thick wick a coating of carbon. The operation is such that this is not consumed and it prevents further burning of the wick. The optical apparatus of navigation lights has undergone many improvements in the past century. The early lights were not equipped with either reflecting or refracting apparatus. In 1824 Drummond devised a scheme for reflecting light in order that a distant observer might make a reading upon the point where the apparatus was being operated by another person. He was led by his experiments to suggest the application of mirrors to lighthouses. His device was essentially a parabolic mirror similar to the reflectors now widely used in automobile head-lamps, search-lights, etc. He employed the lime-light as a source of light and was enthusiastic over the results obtained. His discussion published in 1826 indicates that little practical work had been done up to that time toward obtaining beams or belts of light by means of optical apparatus. However, lighthouse records show that as early as 1763 small silvered plane glasses were set in plaster of Paris in such a manner as to form a partially enveloping reflector. Spherical reflectors were introduced in about 1780 and parabolic reflectors about ten years later. All the earlier lights were "fixed," but as it is desirable that the mariner be able to distinguish one light from another, the revolving mechanism evolved. By its agency characteristic flashes are obtained and from the time interval the light is recognized. The first revolving mechanism was installed in 1783. The early flashing lights were obtained by means of revolving reflectors which gathered the light and directed it in the form of a beam or pencil. The type of parabolic reflector now in use does not differ essentially from that of an automobile head-lamp, excepting that it is larger. Lenses appear to have been introduced in the latter part of the nineteenth century. They were at first ground from a solid piece of glass, in concentric zones, in order to reduce the thickness. They were similar in principle to some of the tail-light lenses used at present on automobiles. Later the lenses were built up by means of separate annular rings. The name of Fresnel is permanently associated with lighthouse lenses because in 1822 he developed an elaborate built-up lens of annular rings. The centers of curvature of the different rings receded from the axis as their distance from the center increased, in such a manner as to overcome a serious optical defect known as spherical aberration. Fresnel devised many improvements in which he used refracting and reflecting prisms for the outer elements. The optical apparatus of lighthouses usually aims (1) to concentrate the rays of light into a pencil of light, (2) to concentrate them into a belt of light, or (3) to concentrate the rays over a limited azimuth. In the first case a single lens or a parabolic reflector suffices, but in the second case a cylindrical lens which condenses the light vertically into a horizontal sheet of light is essential. The third case is a combination of the first two. The modern lighthouse lenses are very elaborate in construction, being built up by means of many elements into several sections. For example, the central section may consist of a spherical lens ground with annular rings. In the next section refracting prisms may be used and in the outer section reflecting glass prisms are employed. The various elements are carefully designed according to the laws of geometrical optics. The flashing light has such advantages over the fixed that it is generally used for important beacons. A variety of methods of obtaining intermittent light have been employed, but they are not of particular interest. Sometimes the lens or reflector is revolved and in other types an opaque screen containing slits is revolved. In the larger lighthouses the optical apparatus and its structure sometimes weigh several tons. When it is necessary to revolve apparatus of this weight, the whole mechanism is floated upon mercury contained in a cast-iron vessel of suitable size, and by an ingenious arrangement only a small portion of mercury is required. The characteristics of navigation lights are varied considerably in order to enable the mariner to distinguish them and thereby to learn exactly where he is. The fixed light is liable to be confused with others, so it has now become a minor light. Flashes of short duration followed by longer periods of darkness are extensively used. The mariner by timing the intervals is able to recognize the light. This method is extended to groups of short flashes followed by longer intervals of darkness. In fact, short flashes have been employed to indicate a certain number so that a mariner could recognize the light by a number rather than by means of his watch. However, a time element is generally used. A combination of fixed light upon which is superposed a flash or a group of flashes of white or of colored light has been used, but it is in disrepute as being unreliable. A type known as "occulating lights" consists of a fixed light which is momentarily eclipsed, but the duration of the eclipse is usually less than that of the light. Obviously, groups of eclipses may be used. Sometimes lights of different colors are alternated without any dark intervals. The colored ones used are generally red and green, but these are short-range lights at best. Colored sectors are sometimes used over portions of the field, in order to indicate dangers, and white light shows in the fairway. These are usually fixed lights for marking the channel. The distance at which a light may be seen at sea depends upon its luminous intensity, upon its color or spectral composition, upon its height and that of the observer's eyes above the sea-level, and upon the atmospheric conditions. Assuming a perfectly clear atmosphere, the visibility of a light-source apparently depends directly upon its candle-power. The atmosphere ordinarily absorbs the red, orange, and yellow rays less than the green, blue, and violet rays. This is demonstrated by the setting sun, which as it approaches closer to the horizon changes from yellow to orange and finally to red as the amount of atmosphere between it and the eye increases. For this reason a red light would have a greater range than a blue light of the same luminous intensity. Under ordinary atmospheric conditions the range of the more powerful light-sources used in lighthouses is greater than the range as limited by the curvature of the earth. For the uncolored illuminants the range in nautical miles appears to be at least equal to the square root of the candle-power. A real practical limitation which still exists is the curvature of the earth, and the distance an object may be seen by the eye at sea-level depends upon the height of the object. The relation is approximately expressed thus,-- Range in nautical miles = 8/7 square root of Height of object in feet. For example, the top of a tower 100 feet high is visible to an eye at sea-level a distance of 8/7 square root of 100 = 80/7 = 11.43 miles. Now if the eye is 49 feet above sea-level, a similar computation will show how far away it may be seen by the original eye at sea-level. This is 8/7 square root of 49 = 8 miles. Hence an eye 49 feet above sea-level will be able to see the top of the 100-foot tower at a distance of 11.43 + 8 or 19.43 nautical miles. Under these conditions an imaginary line drawn from the top of the tower to the eye will be just tangent to the spherical surface of the sea at a distance of 8 miles from the eye and 11.43 miles from the tower. The luminous intensity of a light-source or of the beam of light is directly responsible for the range. The luminous intensity of the early beacon-fires and oil-lamps was equivalent to a few candles. The improvements in light-sources and also in reflecting and refracting optical systems have steadily increased the candle-power of the beams, until to-day the beams from gas-lamps have intensities as high as several hundred thousand candle-power. The beams sent forth by modern lighthouses equipped with electric lamps and enormous light-gathering devices are rated in millions of candle-power. In fact, Navesink Light at the entrance of New York Bay is rated as high as 60,000,000 candle-power. Of course, light-production has increased enormously in efficiency in the past century, but without optical devices for gathering the light, the enormous beam intensity would not be obtained. For example, consider a small source of light possessing a luminous intensity of one candle in all directions. If all this light which is emitted in all directions is gathered and sent forth in a beam of small angle, say one thousandth of the total angle surrounding a point, the intensity of this beam would be 1000 candles. It is in this manner that the enormous beam intensities are built up. There is an interesting point pertaining to short flashes of light. To the dark-adapted eye a brief flash is registered as of considerably higher intensity than if the light remained constant. In other words, the lookout on a vessel is adapted to darkness and a flash from a beam of light is much brighter than if the same beam were shining steadily. This is a physiological phenomenon which operates in favor of the flashing light. [Illustration: A. A COMPLETED LIGHTHOUSE LENS] [Illustration: B. TORRO POINT LIGHTHOUSE, PANAMA CANAL] [Illustration: AMERICAN SEARCH-LIGHT POSITION ON WESTERN FRONT IN 1919] [Illustration: AMERICAN STANDARD FIELD SEARCH-LIGHT AND POWER UNIT] Doubtless, the reader has noted that reliability, simplicity, and low cost of operation are the primary considerations for light-sources used as aids to navigation. This accounts for the continued use of oil and gas. From an optical standpoint the electric arc-lamps and concentrated-filament lamps are usually superior to the earlier sources of light, but the complexity of a plant for generating electricity is usually a disadvantage in isolated places. The larger light-ships are now using electricity generated by apparatus installed in the vessels. There seems to be a tendency toward the use of more buoys and fewer lighthouses, but the beam-intensities of the latter are increasing. In the hundred years since the Boston Light was built the same great changes wrought by the development of artificial light in other activities of civilization have appeared in the beacons of the mariner. The development of these aids to navigation has been wonderful, but it must go on and on. The surface of the earth comprises 51,886,000 square statute miles of land and 145,054,000 square miles of water. Three fourths of the earth's surface is water and the oceans will always be highways of world commerce. All the dangers cannot be overcome, but human ingenuity is capable of great achievements. Wreckage will appear along the shore-lines despite the lights, but the harvest of the shoals has been much reduced since the time described by Robert Louis Stevenson, when the coast people in the Orkneys looked upon wrecks as a source of gain. He states: It had become proverbial with some of the inhabitants to observe that "if wrecks were to happen, they might as well be sent to the poor island of Sanday as anywhere else." On this and the neighboring island, the inhabitants have certainly had their share of wrecked goods. On complaining to one of the pilots of the badness of his boat's sails, he replied with some degree of pleasantry, "Had it been His [God's] will that you come na here wi these lights, we might a' had better sails to our boats and more o' other things." In the leasing of farms, a location with a greater probability of shipwreck on the shore brought a much higher rent. XIV ARTIFICIAL LIGHT IN WARFARE When the recent war broke out science responded to the call and under the stress of feverish necessity compressed the normal development of a half-century into a few years. The airplane, in 1914 a doubtful plaything of daredevils, emerged from the war a perfected thing of the air. Lighting did not have the glamor of flying or the novelty of chemical warfare, but it progressed greatly in certain directions and served well. While artificial lighting conducted its unheralded offensive by increasing production in the supporting industries and helped to maintain liaison with the front-line trenches by lending eyes to transportation, it was also doing its part at the battle front. Huge search-lights revealed the submarine and the aërial bomber; flares exposed the manoeuvers of the enemy; rockets brought aid to beleaguered vessels and troops; pistol lights fired by the aërial observer directed artillery fire; and many other devices of artificial light were in the fray. Many improvements were made in search-lights and in signaling devices and the elements of the festive fireworks of past ages were improved and developed for the needs of modern warfare. Night after night along the battle front flares were sent up to reveal patrols and any other enemy activity. On the slightest suspicion great swarms of these brilliant lights would burst forth as though flocks of huge fireflies had been disturbed. They were even used as light barrages, for movements could be executed in comparative safety when a large number of these lights lay before the enemy's trenches sputtering their brilliant light. The airman dropped flares to illuminate his target or his landing field. The torches of past parades aided the soldier in his night operations and rockets sent skyward radiated their messages to headquarters in the rear. The star-shell had the same missions as other flares, but it was projected by a charge of powder from a gun. These and many modifications represent the useful applications of what formerly were mere "fireworks." Those which are primarily signaling devices are discussed in another chapter, but the others will be described sufficiently to indicate the place which artificial light played in certain phases of warfare. The illuminating compounds used in these devices are not particularly new, consisting essentially of a combustible powder and chemical salts which make the flame luminous and give it color when desired. Among the ingredients are barium nitrate, potassium perchlorate, powdered aluminum, powdered magnesium, potassium nitrate, and sulphur. One of the simplest mixtures used by the English is, Barium nitrate 37 per cent. Powdered magnesium 34 per cent. Potassium nitrate 29 per cent. The magnesium is coated with hot wax or paraffin, which not only acts as a binder for the mixture when it is pressed into its container but also serves to prevent oxidation of the magnesium when the shells are stored. The barium and potassium nitrates supply the oxygen to the magnesium, which burns with a brilliant white flame. The potassium nitrate takes fire more readily than the barium nitrate, but it is more expensive than the latter. Owing to the cost of magnesium, powdered aluminum has been used to some extent as a substitute. Aluminum does not have the illuminating value of magnesium and it is more difficult to ignite, but it is a good substitute in case of necessity. An English mixture containing these elements is, Barium nitrate 58 per cent. Magnesium 29 per cent. Aluminum 13 per cent. Mixtures which are slow to ignite must be supplemented by a primary mixture which is readily ignited. For obtaining colored lights it is only necessary to add chemicals which will give the desired color. The mixtures can be proportioned by means of purely theoretical considerations; that is, just enough oxygen can be present to burn the fuel completely. However, usually more oxygen is supplied than called for by theory. The illuminating shell is perhaps the most useful of these devices to the soldier. It has been constructed with and without parachutes, the former providing an intense light for a brief period because it falls rapidly. These shells of the larger calibers are equipped with time-fuses and are generally rather elaborate in construction. The shell is of steel, and has a time-fuse at the tip. This fuse ignites a charge of black powder in the nose of the shell and this explosion ejects the star-shell out of the rear of the steel casing. At the same time the black powder ignites the priming mixture next to it, which in turn ignites the slow-burning illuminating compound. The star-shell has a large parachute of strong material folded in the rear of the casing and the cardboard tube containing the illuminating mixture is attached to it. The time of burning varies, but is ordinarily less than a minute. Certain structural details must be such as to endure the stresses of a high muzzle velocity. Furthermore, a velocity of perhaps 1000 feet per second still obtains when the star-shell with its parachute is ejected at the desired point in the air. The non-parachute illuminating shell is designed to give an intense light for a brief interval and is especially applicable to defense against air raids. Such a light aims to reveal the aircraft in order that the gunners may fire at it effectively. These shells are fitted with time-fuses which fire the charge of black powder at the desired interval after the discharge of the shell from the gun. The contents of the shell are thereby ejected and ignited. The container for the illuminating material is so designed that there is rapid combustion and consequently a brilliant light for about ten seconds. The enemy airman in this short time is unable to obtain any valuable knowledge pertaining to the earth below and furthermore he is likely to be temporarily blinded by the brilliant light if it is near him. The rifle-light which resembles an ordinary rocket, is fired from a rifle and is designed for short-range use. It consists of a steel cylindrical shell a few inches long fastened to a steel rod. A parachute is attached to the cardboard container in which the illuminating mixture is packed and the whole is stowed away in the steel shell. Shore delay-fuses are used for starting the usual cycle of events after the rifle-light has been fired from the gun. The steel rod is injected into the barrel of a rifle and a blank cartridge is used for ejecting this rocket-like apparatus. Owing to inertia the firing-pin in the shell operates and the short delay-fuse is thus fired automatically an instant after the trigger of the rifle is pulled. Illuminating "bombs" of the same general principles are used by airmen in search of a landing for himself or for a destructive bomb; in signaling to a gunner, and in many other ways. They are simple in construction because they need not withstand the stresses of being fired from a gun; they are merely dropped from the aircraft. The mechanism of ignition and the cycle of events which follow are similar to those of other illuminating shells. The value of such artificial-lighting devices depends both upon luminous intensity and time of burning. Although long-burning is not generally required in warfare, it is obvious that more than a momentary light is usually needed. In general, high candle-power and long-burning are opposed to each other, so that the most intense lights of this character usually are of short duration. Typical performances of two flares of the same composition are as follows: Flare No. 1 Flare No. 2 Average candle-power 270,000 95,000 Seconds of burning 10 35 Candle-seconds 2,700,000 3,325,000 Cubic inches of compound 6 7 Candle-seconds per cubic inch 450,000 475,000 Candle-hours per cubic inch 125 132 The illuminating compound was the same in these two flares, which differed only in the time allowed for burning. Of course, the measurements of the luminous intensity of such flares is difficult because of the fluctuations, but within the errors of the measurements it is seen that the illuminating power of the compound is about the same regardless of the time of burning. The light-source in the case of burning powders is really a flame, and inasmuch as the burning end hangs downward, more light is emitted in the lower hemisphere than in the upper. The candle-power of the largest flares equals the combined luminous intensities of 200 street arc-lamps or of 10,000 ordinary 40-watt tungsten lamps such as are used in residence lighting. It is interesting to note the candle-hours obtained per cubic inch of compound and to find that the cost of this light is less than that of candles at the present time and only five or ten times greater than that of modern electric lighting. Illuminating shells in use during the recent war were designed for muzzle velocities as high as 2700 feet per second and were gaged to ignite at any distance from a quarter of a mile to several miles. The maximum range of illuminating shells fired from rifles was about 200 yards; for trench mortars about one mile; and from field and naval guns about four miles. The search-light has long been a valuable aid in warfare and during the recent conflict considerable attention was given to its development and application. It is used chiefly for detecting and illuminating distant targets, but this covers a wide range of conditions and requirements. In order that a search-light may be effective at a great distance, as much as possible of the light emitted by a source is directed into a beam of light of as nearly parallel rays as can be obtained. Reflectors are usually employed in military search-lights, and in order that the beam may be as nearly parallel (minimum divergence) as possible, the light must be emitted by the smallest source compatible with high intensity. This source is placed at the proper point in respect to a large parabolic reflecter which renders the rays parallel or nearly so. Ever since its advent the electric arc has been employed in large search-lights, with which the army and the navy were supplied; however, the greatest improvements have been made under the stress of war. The science of aëronautics advanced so rapidly during the recent war that the necessity for powerful search-lights was greatly augmented and as the conflict progressed the enemy airmen came to look upon the newly developed ones with considerable concern. The rapidly moving aircraft and its high altitude brought new factors into the design of these lights. It now became necessary to have the most intense beam and to be able to sweep the heavens with it by means of delicate controlling apparatus, for the targets were sometimes minute specks moving at high speed at altitudes as high as five miles. Furthermore, owing to the shifting battle areas, mobile apparatus was necessary. The control of light by means of reflectors has been studied for centuries, but until the advent of the electric arc the light-sources were of such large areas that effective control was impossible. Optical devices generally are considered in connection with "point sources," but inasmuch as no light can be obtained from a point, a source of small dimensions and of high brightness is the most effective compromise. Parabolic mirrors were in use in the eighteenth century and their properties were known long before the first search-light worthy of the name was made in 1825 by Drummond, who used as a source of light a piece of lime heated to incandescence in a blast flame. He finally developed the "lime-light" by directing an oxyhydrogen flame upon a piece of lime and this device was adapted to search-lights and to indoor projection. It is said that the first search-light to be used in warfare was a Drummond lime-light which played a part in the attack on Fort Wagner at Charleston in 1863. In 1848 the first electric arc lamp used for general lighting was installed in Paris. It was supplied with current by a large voltaic cell, but the success of the electric arc was obliged to await the development of a more satisfactory source of electricity. A score of years was destined to elapse, after the public was amazed by the first demonstration, before a suitable electric dynamo was invented. With the advent of the dynamo, the electric arc was rapidly developed and thus there became available a concentrated light-source of high intensity and great brilliancy. Gradually the size was increased, until at the present time mirrors as large as seven feet in diameter and electric currents as great as several hundred amperes are employed. The beam intensities of the most powerful search-lights are now as great as several hundred million candles. The most notable advance in the design of arc search-lights was achieved in recent years by Beck, who developed an intensive flame carbon-arc. His chief object was to send a much greater current through the arc than had been done previously without increasing the size of the carbons and the unsteadiness of the arc. In the ordinary arc excessive current causes the carbons to disintegrate rapidly unless they are of large diameter. Beck directed a stream of alcohol vapor at the arc and they were kept from oxidizing. He thus achieved a high current-density and much greater beam intensities. He also used cored carbons containing certain metallic salts which added to the luminous intensity, and by rotation of the positive carbon so that the crater was kept in a constant position, greater steadiness and uniformity were obtained. Tests show that, in addition to its higher luminous efficiency, an arc of this character directs a greater percentage of the light into the effective angle of the mirror. The small source results in a beam of small divergence; in other words, the beam differs from a cylinder by only one or two degrees. If the beam consisted entirely of parallel rays and if there were no loss of light in the atmosphere by scattering or by absorption, the beam intensity would be the same throughout its entire length. However, both divergence and atmospheric losses tend to reduce the intensity of the beam as the distance from the search-light increases. Inasmuch as the intensity of the beam depends upon the actual brightness of the light-source, the brightness of a few modern light-sources are of interest. These are expressed in candles per square inch of projected area; that is, if a small hole in a sheet of metal is placed next to the light-source and the intensity of the light passing through this hole is measured, the brightness of the hole is easily determined in candles per square inch. BRIGHTNESS OF LIGHT-SOURCES IN CANDLES PER SQUARE INCH Kerosene flame 5 to 10 Acetylene 30 to 60 Gas-mantle 30 to 500 Tungsten filament (vacuum) lamp 750 to 1,200 Tungsten filament (gas-filled) lamp 3,500 to 18,000 Magnetite arc 4,000 to 6,000 Carbon arc for search-lights 80,000 to 90,000 Flame arc for search-lights 250,000 to 350,000 Sun (computed mean) about 1,000,000 As the reflector of a search-light is an exceedingly important factor in obtaining high beam-intensities, considerable attention has been given to it since the practicable electric arc appeared. The parabolic mirror has the property of rendering parallel, or nearly so, the rays from a light-source placed at its focus. If the mirror subtends a large angle at the light-source, a greater amount of light is intercepted and rendered parallel than in the case of smaller subtended angles; hence, mirrors are large and of as short focus as practicable. Search-light projectors direct from 30 to 60 per cent. of the available light into the beam, but with lens systems the effective angle is so small that a much smaller percentage is delivered in the beam. Mangin in 1874 made a reflector of glass in which both outer and inner surfaces were spherical but of different radii of curvature, so that the reflector was thicker in the middle. This device was "silvered" on the outside and the refraction in the glass, as the light passed through it to the mirror and back again, corrected the spherical aberration of the mirrored surface. These have been extensively used. Many combinations of curved surfaces have been developed for special projection purposes, but the parabolic mirror is still in favor for powerful search-lights. The tip of the positive carbon is placed at its focus and the effective angle in which light is intercepted by the mirror is generally about 125 degrees. Within this angle is included a large portion of the light emitted by the light-source in the case of direct-current arcs. If this angle is increased for a mirror of a given diameter by decreasing its focal length, the divergence of the beam is increased and the beam-intensity is diminished. This is due to the fact that the light-source now becomes apparently larger; that is, being of a given size it now subtends a larger angle at the reflector and departs more from the theoretical point. When the recent war began the search-lights available were intended generally for fixed installations. These were "barrel" lights with reflectors several feet in diameter, the whole output sometimes weighing as much as several tons. Shortly after the entrance of this country into the war, a mobile "barrel" search-light five feet in diameter was produced, which, complete with carriage, weighed only 1800 pounds. Later there were further improvements. An example of the impetus which the stress of war gives to technical accomplishments is found in the development of a particular mobile searchlight. Two months after the War Department submitted the problems of design to certain large industrial establishments a new 60-inch search-light was placed in production. It weighed one fifth as much as the previous standard; it had one twentieth the bulk; it was much simpler; it could be built in one fourth the time; and it cost half as much. Remote control of the apparatus has been highly developed in order that the operator may be at a distance from the scattered light near the unit. If he is near the search-light, this veil of diffused light very seriously interferes with his vision. Mobile power-units were necessary and the types developed used the automobile engine as the prime mover. In one the generator is located in front of the engine and supported beyond the automobile chassis. In another type the generator is located between the automobile transmission and the differential. A standard clutch and gear-shift lever is employed to connect the engine either with the generator or with the propeller shaft of the truck. The first type included a 115-volt, 15-kilowatt generator, a 36-inch wheel barrel search-light, and 500 feet of wire cable. The second type included a 105-volt, 20-kilowatt generator, a 60-inch open searchlight, and 600 feet of cable. This type has been extended in magnitude to include a 50-kilowatt generator. When these units are moved, the search-light and its carriage are loaded upon the rear of the mobile generating equipment. An idea of the intensities obtainable with the largest apparatus is gained from illumination produced at a given distance. For example, the 15-kilowatt search-light with highly concentrated beam, produced an illumination at 930 feet of 280 foot-candles. At this point this is the equivalent of the illumination produced by a source having a luminous intensity of nearly 250,000,000 candles. Of course, the range at which search-lights are effective is the factor of most importance, but this depends upon a number of conditions such as the illumination produced by the beam at various distances, the atmospheric conditions, the position of the observer, the size, pattern, color, and reflection-factor of the object, and the color, pattern, and reflection-factor of the background. These are too involved to be discussed here, but it may be stated that under ordinary conditions these powerful lights are effective at distances of several miles. According to recent work, it appears that the range of a search-light in revealing a given object under fixed conditions varies about as the fourth root of its intensity. Although the metallic parabolic reflector is used in the most powerful search-lights, there have been many other developments adapted to warfare. Fresnel lenses have been used above the arc for search-lights whose beams are directed upward in search of aircraft, thus replacing the mirror below the arc, which, owing to its position, is always in danger of deterioration by the hot carbon particles dropping upon it. For short ranges incandescent filament lamps have been used with success. Oxyacetylene equipment has found application, owing to its portability. The oxyacetylene flame is concentrated upon a small pellet of ceria, which provides a brilliant source of small dimensions. A tank containing about 1000 liters of dissolved acetylene and another containing about 1100 liters of oxygen supply the fuel. A beam having an intensity of about 1,500,000 candles is obtained with a consumption of 40 liters of each of the gases per hour. At this rate the search-light may be operated twenty hours without replenishing. Although the beacon-light for nocturnal airmen is a development which will assume much importance in peaceful activities, it was developed chiefly to meet the requirements of warfare. These do not differ materially from those which guide the mariner, except that the traveler in the aërial ocean is far above the plane on which the beacon rests. For this reason the lenses are designed to send light generally upward. In foreign countries several types of beacons for aërial navigation have been in use. In one the light from the source is freely emitted in all upward directions, but the light normally emitted into the lower hemisphere is turned upward by means of prisms. In a more elaborate type, belts of lenses are arranged so as to send light in all directions above the horizontal plane. A flashing apparatus is used to designate the locality by the number or character of the flashes. Electric filaments and acetylene flames have been used as the light-sources for this purpose. In another type the light is concentrated in one azimuth and the whole beacon is revolved. Portable beacons employing gas were used during the war on some of the flying-fields near the battle front. All kinds of lighting and lighting-devices were used depending upon the needs and material available. Even self-luminous paint was used for various purposes at the front, as well as for illuminating watch-dials and the scales of instruments. Wooden buttons two or three inches in diameter covered with self-luminous paint could be fixed wherever desired and thus serve as landmarks. They are visible only at short distances and the feebleness of their light made them particularly valuable for various purposes at the battle front. They could be used in the hand for giving optical signals at a short distance where silence was essential. Self-luminous arrows and signs directed troops and trucks at night and even stretcher-bearers have borne self-luminous marks on their backs in order to identify them to their friends. Somewhat analogous to this application of luminous paint is the use of blue light at night on battle-ships and other vessels in action or near the enemy. Several years ago a Brazilian battle-ship built in this country was equipped with a dual lighting-system. The extra one used deep-blue light, which is very effective for eyes adapted to darkness or to very low intensities of illumination and is a short-range light. Owing to the low luminous intensity of the blue lights they do not carry far; and furthermore, it is well established that blue light does not penetrate as far through ordinary atmosphere as lights of other colors of the same intensity. The war has been responsible for great strides in certain directions in the development and use of artificial light and the era of peace will inherit these developments and will adapt them to more constructive purposes. XV SIGNALING From earliest times the beacon-fire has sent forth messages from hilltops or across inaccessible places. In this country, when the Indian was monarch of the vast areas of forest and prairie, he spread news broadcast to roving tribesmen by means of the signal-fire, and he flashed his code by covering and uncovering it. Castaways, whether in fiction or in reality, instinctively turn to the beacon-fire as a mode of attracting a passing ship. On every hand throughout the ages this simple means of communication has been employed; therefore, it is not surprising that mankind has applied his ingenuity to the perfection of signaling by means of light, which has its own peculiar fields and advantages. Of course, wireless telephony and telegraphy will replace light-signaling to some extent, but there are many fields in which the last-named is still supreme. In fact, during the recent war much use was made of light in this manner and devices were developed despite the many other available means of signaling. One of the chief advantages of light as a signal is that it is so easily controlled and directed in a straight line. Wireless waves, for example, are radiated broadcast to be intercepted by the enemy. The beginning of light-signaling is hidden in the obscurity of the past. Of course, the most primitive light-signals were wood fires, but it is likely that man early utilized the mirror to reflect the sun's image and thus laid the foundation of the modern heliograph. The Book of Job, which is probably one of the oldest writings available, mentions molten mirrors. The Egyptians in the time of Moses used mirrors of polished brass. Euclid in the third century before the Christian era is said to have written a treatise in which he discussed the reflection of light by concave mirrors. John Peckham, Archbishop of Canterbury in the thirteenth century, described mirrors of polished steel and of glass backed with lead. Mirrors of glass coated with an alloy of tin and mercury were made by the Venetians in the sixteenth century. Huygens in the seventeenth century studied the laws of refraction and reflection and devised optical apparatus for various purposes. However, it was not until the eighteenth century that any noteworthy attempts were made to control artificial light for practical purposes. Dollond in 1757 was the first to make achromatic lenses by using combinations of different glasses. Lavoisier in 1774 made a lens about four feet in diameter by constructing a cell of two concave glasses and filling it with water and other liquids. It is said that he ignited wood and melted metals by concentrating the sun's image upon them by means of this lens. About that time Buffon made a built-up parabolic mirror by means of several hundred small plane mirrors set at the proper angles. With this he set fire to wood at a distance of more than two hundred feet by concentrating the sun's rays. He is said also to have made a lens from a solid piece of glass by grinding it in concentric steps similar to the designs worked out by Fresnel seventy years later. These are examples of the early work which laid the foundation for the highly perfected control of light of the present time. While engaged in the survey of Ireland, Thomas Drummond in 1826 devised apparatus for signaling many miles, thus facilitating triangulation. Distances as great as eighty miles were encountered and it appeared desirable to have some method for seeing a point at these great distances. Gauss in 1822 used the reflection of the sun's image from a plane mirror and Drummond also tried this means. The latter was successful in signaling 45 miles to a station which because of haze could not be seen, or even the hill upon which it rested. Having demonstrated the feasibility of the plan, he set about making a device which would include a powerful artificial light in order to be independent of the sun. In earlier geodetic surveys Argand lamps had been employed with parabolic reflectors and with convex lenses, but apparently these did not have a sufficient range. Fresnel and Arago constructed a lens consisting of a series of concentric rings which were cemented together, and on placing this before an Argand lamp possessing four concentric wicks, they obtained a light which was observed at forty-eight miles. Despite these successes, Drummond believed the parabolic mirror and a more powerful light-source afforded the best combination for a signal-light. In searching for a brilliant light-source he experimented with phosphorus burning in oxygen and with various brilliant pyrotechnical preparations. However, flames were unsteady and generally unsuitable. He then turned in the direction which led to his development of the lime-light. In his first apparatus he used a small sphere of lime in an alcohol flame and directed a jet of oxygen through the flame upon the lime. He thereby obtained, according to his own description in 1826, a light so intense that when placed in the focus of a reflector the eye could with difficulty support its splendor, even at a distance of forty feet, the contour being lost in the brilliancy of the radiation. He then continued to experiment with various oxides, including zirconia, magnesia, and lime from chalk and marble. This was the advent of the lime-light, which should bear Drummond's name because it was one of the greatest steps in the evolution of artificial light. By means of this apparatus in the survey, signals were rendered visible at distances as great as one hundred miles. Drummond proposed the use of this light-source in the important lighthouses at that time and foresaw many other applications. The lime-light eventually was extensively used as a light-signaling device. The heliograph, which utilizes the sun as a light-source, has been widely used as a light-signaling apparatus and Drummond perhaps was the first to utilize artificial light with it. The disadvantage of the heliograph is the undependability of the sun. With the adoption of artificial light, various optical devices have come into use. Philip Colomb perhaps is deserving of the credit of initiating modern signaling by flashing a code. He began work on such a system in 1858 and as an officer in the British Navy worked hard to introduce it. Finally, in 1867, the British Navy adopted the flashing-system, in which a light-source is exposed and eclipsed in such a manner as to represent dots and dashes analogous to the Morse code. At first the rate of transmission of words was from seven to ten per minute. Recently much more sensitive apparatus is available, and with such devices the rate is limited only by the sluggishness of the visual process. This initial system was very successful in the British Navy and it was soon found that a fleet could be handled with ease and safety in darkness or in fog. Inasmuch as the "dot-and-dash" system requires only two elements, it may be transmitted by various means. A lantern may be swung in short and long arcs or dipped accordingly. The blinker or pulsating light-signal consists of a single light-source mechanically occulted. It is controlled by means of a telegraph-key and the code may be rapidly transmitted. The search-light affords a means for signaling great distances, even in the daytime. The light is usually mechanically occulted by a quick-acting shutter, but recently another system has been devised. In the latter the light itself is controlled by means of an electrical shunt across the arc. In this manner the light is dimmed by shunting most of the current, thereby producing the same effect as actually eclipsing the light with a mechanical shutter. By means of the search-light signals are usually visible as far as the limitations of the earth's curvature will permit. By directing the beam against a cloud, signals have been observed at a distance of one hundred miles from the search-light despite intervening elevated land or the curvature of the ocean's surface. By means of small search-lights it is easy to send signals ten miles. This kind of apparatus has the advantage of being selective; that is, the signals are not visible to persons a few degrees from the direction of the beam. One of the most recent developments has been a special tungsten filament in a gas-filled bulb placed at the focus of a small parabolic mirror. The beam is directed by means of sights and the flashes are obtained by interrupting the current by means of a trigger-switch. The filament is so sensitive that signals may be sent faster than the physiological process of vision will record. With the advent of wireless telegraphy light-signaling for long distances was temporarily eclipsed, but during the recent war it was revived and much development work was prosecuted. The Ardois system consists of four lamps mounted in a vertical line as high as possible. Each lamp is double, containing a red and a white light, and these lights are controlled from a keyboard. A red light indicates a dot in the Morse code and a white light indicates a dash. The keys are numbered and lettered, so that the system may be operated by any one. Various other systems employing colored lights have been used, but they are necessarily short-range signals. Another example is the semaphore. When used at night, tungsten lamps in reflectors indicate the positions of the arms. The advantage of these signals over the flashing-system is that each signal is complete and easy to follow. The flashing-system is progressive and must be carefully followed in order to obtain the meaning of the dots and dashes. Smaller signal-lamps using acetylene have been employed in the forestry service and in other activities where a portable device is necessary. In one type, a mixture-tank containing calcium carbide and water is of sufficient capacity for three hours of signaling. A small pilot-light is permitted to burn constantly and the flashes are obtained by operating a key which increases the gas-pressure. The light flares as long as the key is depressed. The range of this apparatus is from ten to twenty miles. An electric lamp supplied from a storage battery has been designed for geodetic operations in mountainous districts where it is desired to send signals as far as one hundred miles. Tests show that this device is a hundred and fifty times more powerful than the ordinary acetylene signal-lamp, and it is thought that with this new electric lamp haze and smoke will seldom prevent observations. Certain fixed lights are required by law on a vessel at night. When it is under way there must be a white light at the masthead, a starboard green light, a port red light, a white range-light, and a white light at the stern. The masthead light is designed to emit light through a horizontal arc of twenty points of the compass, ten on each side of dead ahead. This light must be visible at a distance of five miles. The port and starboard lights operate through a horizontal arc of twenty points of the compass, the middle of which is dead ahead. They are screened so as not to be visible across the bow and they must be intense enough to be visible two miles ahead. The masthead light is carried on the foremast and the range-light on the mainmast, at an elevation fifteen feet higher than the former. The range-light emits light toward all points of the compass and must be intense enough to be seen at a distance of three miles. The stern light is similar to the masthead, but its light must not be visible forward of the beam. When a vessel is towing another it must display two or three lights in a vertical line with the masthead light and similar to it. The lights are spaced about six feet apart, and two extra ones indicate a short tow and three a long one. A vessel over a hundred and fifty feet long when at anchor is required to display a white light forward and aft, each visible around the entire horizon. These and many other specifications indicate how artificial light informs the mariner and makes for order in shipping. Without artificial light the waterways would be trackless and chaos would reign. The distress signals of a vessel are rockets, but any burning flame also serves if rockets are unavailable. Fireworks were known many centuries ago and doubtless the possibilities of signaling by means of rockets have long been recognized. An early instance of scientific interest in rockets and their usefulness is that of Benjamin Robins in 1749. While he was witnessing a display of fireworks in London it occurred to him that it would be of interest to measure the height to which the rockets ascended and to determine the ranges at which they were visible. His measurements indicated that the rockets ascended usually to a height of 440 yards, but some of them attained altitudes as high as 615 yards. He then had some special ones made and despatched letters to friends in three different localities, at distances as great as 50 miles, asking them to observe at a certain time, when the rockets were to be sent up in the outskirts of London. Some of these rockets rose to altitudes as great as 600 yards and were distinctly seen by observers 38 miles away. Later he made rockets which ascended as high as 1200 yards and concluded that this was a practical means of signaling. Since that time and especially during the recent war, rockets have served well in signaling messages. The self-propelled rockets have not been altered in essential features since the remote centuries when the Chinese first used them in celebrations. A cylindrical shell is mounted on a wooden stick and when the powder in the shell burns the hot gases are ejected so violently downward that the reaction drives the shell upward. At a certain point in the air, various signals burst forth, which vary in character and color. One of the advantages of the rocket is that it contains within itself the force of propulsion; that is, no gun is necessary to project it. The illuminating compounds and various details are similar to those of the illuminating shells described in another chapter. At present the rocket is not scientifically designed to obtain the greatest efficiency of propulsion, but its simplicity in this respect is one of its chief advantages. If the self-propelled rocket becomes the projectile of the future, as some have ventured to predict, much consideration must be given to the design of the orifice through which the gases violently escape in order that the best efficiency of propulsion may be attained. There are other details in which improvements may be made. The combustion products of the black powder which are not gaseous equal about one third the weight of the powder. This represents inefficient propulsion. Furthermore, during recent years much information has been gained pertaining to the air-resistance which can be applied to advantage in designing the form of rockets. Besides the various rockets, signal-lights have been constructed to be fired from guns and pistols. During the recent war the airman in the dark heights used the pistol signal-light effectively for communication. These devices emitted stars either singly or in succession, and the color of these stars as well as their number and sequence gave significance to the signal. Some of these light-signals were provided with parachutes and were long-burning; that is, light was emitted for a minute or two. There are many variations possible and a great many different kinds of light-signals of this character were used. In the front-line trenches and in advances they were used when telephone service was unavailable. The airman directed artillery fire by means of his pistol-light. Rockets brought aid to the foundered ship or to the life-boats. The signal-tube which burned red, green, or white was held in the hand or laid on the ground and it often told its story. For many years such a device dropped from the rear of the railroad train has kept the following train at a safe distance. A device was tried out in the trenches, during the war, which emitted a flame. This could be varied in color to serve as a signal and the apparatus had sufficient capacity for thirty hours' burning. This could also be used as a weapon, or when reduced in intensity it served as a flash-light. For many years experiments have been made upon the use of the invisible rays which accompany visible rays. The practicability of signaling with invisible rays depends upon producing them efficiently in sufficient quantity and upon separating them from the visible rays which accompany them. Some successful results were obtained with a 6-volt electric lamp possessing a coiled filament at the focus of a lens three inches in diameter and twelve inches in focal length. This gave a very narrow beam visible only in the neighborhood of the observation post to which the signals were directed. The beam was directed by telescopic sights. During the day a deep red filter was placed over the lamp and the light was invisible to an observer unless he was equipped with a similar red screen to eliminate the daylight. It is said that signals were distinguished at a distance of six miles. By night a screen was used which transmitted only the ultraviolet rays, and the observer's telescope was provided with a fluorescent screen in its focal plane. The ultraviolet rays falling upon this screen were transformed into visible rays by the phenomenon of fluorescence. The range of this device was about six miles. For naval convoys lamps are required to radiate toward all points of the compass. For this purpose a quartz mercury-arc which is rich in ultraviolet rays was surrounded with a chimney which transmitted the ultraviolet rays efficiently and absorbed all visible rays excepting violet light. The lamp appeared a deep violet color at close range, but the faintly visible light which it transmitted was not seen at a distance. A distant observer picks up the invisible ultraviolet "light" by means of a special optical device having a fluorescent screen of barium-platino-cyanide. This device had a range of about four miles. Light-signals are essential for the operation of railways at night and they have been in use for many years. In this field the significance of light-signals is based almost universally on color. The setting of a switch is indicated by the color of the light that it shows. With the introduction of the semaphore system, in which during the day the position of the arm is significant, colored glasses were placed on the opposite end of the arm in such a manner that a certain colored glass would appear before the light-source for a certain position of the arm. A kerosene flame behind a glass lens was the lamp used, and, for example, red meant "Stop," green counseled "Caution," and clear or white indicated "All clear." For many years the kerosene lamp has been used, but recently the electric filament lamp is being installed to some extent for this purpose. In fact, on one railroad at least, tungsten lamps are used for light-signals by day as well as by night. Three signals--red, green, and white--are placed in a vertical line and behind each lens are two lamps, one operating at high efficiency and one at low efficiency to insure against the failure of the signal. The normal daylight range is about three thousand feet and under the worst conditions when opposed to direct sunlight, the range is not less than two thousand feet. It is said that these lights are seen more easily than semaphore arms under all circumstances and that they show two or three times as far as the latter during a snow-storm. The standard colors for light-signals as adopted by the Railway Signal Association are red, yellow, green, blue, purple, and lunar white. These are specified as to the amount of the various spectral colors which they transmit when the light-source is the kerosene flame. Obviously, the colors generally appear different when another illuminant is used. The blue and purple are short-range signals, but the effective range of the best railway signal employing a kerosene flame is only about four miles. It has been shown that the visibility of point sources of white light in clear atmosphere, for distances up to a mile at least, is proportional to their candle-power and inversely proportional to the square of the distance. Apparently the luminous intensities of signal-lamps required in clear weather in order that they may be visible must be 0.43 candles for one nautical mile, 1.75 candles for two nautical miles, and 11 candles for five nautical miles. From the data available it appears that a red or a white signal-light will be easily visible at a distance in nautical miles equal to the square root of its candle-power in that direction. The range in nautical miles of a green light apparently is proportional to the cube root of the candle-power. Whether or not these relations between the range in miles and the luminous intensity in candles hold for greater distances than those ordinarily encountered has not been determined, but it is interesting to note that the square root of the luminous intensity of the Navesink Light at the entrance to New York Harbor is about 7000. Could this light be seen at a distance of seven thousand miles through ordinary atmosphere? The most distinctive colored lights are red, yellow, green, and blue. To these white (clear) and purple have been added for signaling-purposes. Yellow is intense, but it may be confused with "white" or clear. Blue and purple as obtained from the present practicable light-sources are of low intensity. This leaves red, green, and clear as the most generally satisfactory signal-lights. There are numerous other applications, especially indoors. Some of these have been devised for special needs, but there are many others which are general, such as for elevators, telephones, various call systems, and traffic signals. Light has the advantages of being silent and controllable as to position and direction, and of being a visible signal at night. Thus, in another field artificial light has responded to the demands of civilization. XVI THE COST OF LIGHT Artificial light is so superior to natural light in many respects that mankind has acquired the habit of retiring many hours after darkness has fallen, a result of which has brought forth the issue known as "daylight saving." Doubtless, daylight should be used whenever possible, but there are two sides to the question. In the first place, it costs something to bring daylight indoors. The architectural construction of windows and skylights increases the cost of daylight. Light-courts, by sacrificing valuable floor-area, add to the expense. The maintenance of windows and sky lights is an appreciable item. Considering these and other factors, it can be seen that daylight indoors is expensive; and as it is also undependable, a supplementary system of artificial lighting is generally necessary. In fact, it is easy to show in some cases that artificial lighting is cheaper than natural lighting. The average middle-class home is now lighted artificially for about $15.00 to $25.00 per year, with convenient light-sources which are available at all times. There is no item in the household budget which returns as much satisfaction, comfort, and happiness in proportion to its cost as artificial light. It is an artistic medium of great potentiality, and light in a narrow utilitarian sense is always a by-product of artistic lighting. The insignificant cost of modern lighting may be emphasized in many ways. The interest on the investment in a picture or a vase which cost $25.00 will usually cover the cost of operating any decorative lamp in the home. A great proportion of the investment in personal property in a home is chargeable to an attempt to beautify the surroundings. The interest on only a small portion of this investment will pay for artistic and utilitarian artificial lighting in the home. The cost of washing the windows of the average house may be as great as the cost of artificial lighting and is usually at least a large fraction of the latter. It would become monotonous to cite the various examples of the insignificant cost of artificial light and its high return to the user. The example of the home has been chosen because the reader may easily carry the analysis further. The industries where costs are analyzed are now looking upon adequate and proper lighting as an asset which brings in profits by increasing production, by decreasing spoilage, and by decreasing the liability of accidents. Inasmuch as daylight saving became an issue during the recent war and is likely to remain a matter of concern, its history is interesting. One of the outstanding differences between primitive and civilized beings is their hours of activities. The former automatically adjusted themselves to daylight, but as civilization advanced, the span of activities began to extend more and more beyond the coming of darkness. Finally in many activities the work-day was extended to twenty-four hours. There can be no insurmountable objection to working at night with a proper arrangement of the periods of work; in fact, the cost of living would be greatly increased if the overhead charges represented by such items as machinery and buildings were allowed to be carried by the decreased products of a shortened period of production. There cannot be any basic objection to artificial lighting, because most factories, for example, may be better illuminated by artificial than by natural light. Of course, the lag of comfortable temperature behind daylight is responsible to some extent for a natural shifting of the ordinary working-day somewhat behind the sun. The chill of dawn tends to keep mankind in bed and the cheer of artificial light and the period of recreation in the evening tends to keep the civilized races out of bed. There are powerful influences always at work and despite the desirable features of daylight-saving, mankind will always tend to lag. As years go by, doubtless it will be necessary to make the shift again and again. It seems certain that throughout the centuries thoughtful persons have seen the difficulty of rousing man from his warm bed in the early morning and have recognized a simple solution in turning the hands of the clock ahead. Among the earliest advocates of daylight saving during modern times, when it became important enough to be considered as an economic issue, was Benjamin Franklin. In 1784 he wrote a masterful serio-comic essay entitled "An Economical Project" which was published in the _Journal_ of Paris. The article, which appeared in the form of a letter, began thus: MESSIEURS: You often entertain us with accounts of new discoveries. Permit me to communicate to the public through your paper one that has lately been made by myself and which I conceive may be of great utility. I was the other evening in a grand company where the new lamp of Messrs. Quinquet and Lange was introduced and much admired for its splendor; but a general inquiry was made whether the oil it consumed was not in exact proportion to the light it afforded, in which case there would be no saving in the use of it. No one present could satisfy us on that point, which all agreed ought to be known, it being a very desirable thing to lessen, if possible, the expense of lighting our apartments, when every other article of family expense was so much augmented. I was pleased to see this general concern for economy, for I love economy exceedingly. I went home, and to bed, three or four hours after midnight, with my head full of the subject. An accidental sudden noise waked me about 6 in the morning, when I was surprised to find my room filled with light, and I imagined at first that a number of those lamps had been brought into it; but, rubbing my eyes, I perceived the light came in at the windows. I got up and looked out to see what might be the occasion of it, when I saw the sun just rising above the horizon, from whence he poured his rays plentifully into my chamber, my domestic having negligently omitted the preceding evening to close the shutters. I looked at my watch, which goes very well, and found that it was but 6 o'clock; and, still thinking it something extraordinary that the sun should rise so early, I looked into the almanac, where I found it to be the hour given for his rising on that day. I looked forward, too, and found he was to rise still earlier every day till toward the end of June, and that at no time in the year he retarded his rising so long as till 8 o'clock. Your readers who, with me, have never seen any signs of sunshine before noon, and seldom regard the astronomical part of the almanac, will be as much astonished as I was when they hear of his rising so early, and especially when I assure them that he gives light as soon as he rises. I am convinced of this. I am certain of my fact. One cannot be more certain of any fact. I saw it with my own eyes. And, having repeated this observation the three following mornings, I found always precisely the same result. He then continues in the same vein to show that learned persons did not believe him and to point out the difficulties which the pioneer encounters. He brought out the vital point by showing that if he had not been awakened so early he would have slept six hours longer by the light of the sun and in exchange he would have lived six hours the following night by candle-light. He then mustered "the little arithmetic" he was master of and made some serious computations. He assumed as the basis of his computations that a hundred thousand families lived in Paris and each used a half-pound of candles nightly. He showed that between March 20th and September 20th, 64,000,000 pounds of wax and tallow could be saved, which was equivalent to $18,000,000. After these serious computations he amusingly proposed the means for enforcing the daylight saving. Obviously, it was necessary to arouse the sluggards and his proposals included the use of cannons and bells. Besides, he proposed that each family be restricted to one pound of candles per week, that coaches would not be allowed to pass after sunset except those of physicians, etc., and that a tax be placed upon every window which had shutters. His closing paragraph was as follows: For the great benefit of this discovery, thus freely communicated and bestowed by me on the public, I demand neither place, pension, exclusive privilege, nor any other regard whatever. I expect only to have the honor of it. And yet I know there are little, envious minds who will, as usual, deny me this and say that my invention was known to the ancients, and perhaps they may bring passages out of the old books in proof of it. I will not dispute with these people that the ancients knew not the sun would rise at certain hours; they possibly had, as we have, almanacs that predicted it; but it does not follow thence that they knew he gave light as soon as he rose. That is what I claim as my discovery. If the ancients knew it, it might have been long since forgotten; for it certainly was unknown to the moderns, at least to the Parisians, which to prove I need use but one plain simple argument. They are as well instructed, judicious and prudent a people as exist anywhere in the world, all professing, like myself, to be lovers of economy, and, for the many heavy taxes required from them by the necessities of the State have surely an abundant reason to be economical. I say it is impossible that so sensible a people, under such circumstances, should have lived so long by the smoky, unwholesome and enormously expensive light of candles, if they had really known that they might have had as much pure light of the sun for nothing. Franklin's amusing letter had a serious aim, for in 1784 family expenses were much augmented and adequate lighting by means of candles was very costly in those days. However, conditions have changed enormously in the past hundred and thirty-five years. A great proportion of the population lives in the darker cities. The wheels of progress must be kept going continuously in order to curb the cost of living, which is constantly mounting higher owing to the addition of conveniences and luxuries. Furthermore, the cost of light has so diminished that it is not only a minor factor at present but in many cases is actually paying dividends in commerce and industry. It is paying dividends of another kind in the social and educational aspects of the home, library, church, and art museum. Daylight saving has much to commend it, but the cost of daylight and the value of artificial light are important considerations. The cost of fuels for lighting purposes cannot be thoroughly compared throughout a span of years without regard to the fluctuating purchasing power of money, which would be too involved for consideration here. However, it is interesting to make a brief survey throughout the past century. From 1800 until 1845 whale-oil sold for about $.80 per gallon, but after this period it increased in value, owing apparently to its growing scarcity, until it reached a price of $1.75 per gallon in 1855. Fortunately, petroleum was discovered about this time, so that the oil-lamp did not become a luxury. From 1800 to 1850 tallow-candles sold at approximately 20 cents a pound. There being six candles to the pound, and inasmuch as each candle burned about seven hours, the light from a candle cost about 1/2 cent per hour. From 1850 to 1875 tallow-candles sold at an average price of approximately 25 cents a pound. It may be interesting to know that a large match emits about as much light as a burning candle and a so-called safety match about one third as much. A candle-hour is the total amount of light emitted by a standard candle in one hour, and candle-hours in any case are obtained by multiplying the candle-power of the source by the hours of burning. In a similar manner, lumens output multiplied by hours of operation give the lumen-hours. A standard candle may be considered to emit an amount of light approximately equal to 10 lumens. A wax-candle will emit about as much light as a sperm candle but will consume about 10 per cent. less weight of material. A tallow candle will emit about the same amount of light with a consumption about 50 per cent. greater. The tallow-candle has disappeared from use. With the appearance of kerosene distilled from petroleum the camphene lamp came into use. The kerosene cost about 80 cents per gallon during the first few years of its introduction. The price of kerosene averaged about 55 cents a gallon between 1865 and 1875. During the next decade it dropped to about 22 cents a gallon and between 1885 and 1895 it sold as low as 13 cents. Artificial gas in 1865 sold approximately at $2.50 per thousand cubic feet; between 1875 and 1885 at $2.00; between 1885 and 1895 at $1.50. The combined effect of decreasing cost of fuel or electrical energy for light-sources and of the great improvements in light-production gave to the householder, for example, a constantly increasing amount of light for the same expenditure. For example, the family which a century ago spent two or three hours in the light of a single candle now enjoys many times more light in the same room for the same price. It is interesting to trace the influence of this greatly diminishing cost of light in the home. For the sake of simplicity the light of a candle will be retained as the unit and the cost of light for the home will be considered to remain approximately the same throughout the period to be considered. In fact, the amount of money that an average householder spends for lighting has remained fairly constant throughout the past century, but he has enjoyed a longer period of artificial light and a greater amount of light as the years advanced. The following is a table of approximate values which shows the lighting obtainable for $20.00 per year throughout the past century exclusive of electricity: Hours Equivalent of Candle-hours Year per night light in candles per night per year 1800 3 5 15 5,500 1850 3 8 24 8,700 1860 3 11 33 12,000 1870 3 22 66 24,000 1880 3.5 36 126 46,000 1890 4 50 200 73,000 1900 5 154 770 280,000 It is seen from the foregoing that in a century the candle-equivalent obtainable for the same cost to the householder increased at least thirty times, while the hours during which this light is used have nearly doubled. In other words, in the nineteenth century the candle-hours obtainable for $20.00 per year increased about fifty times. Stated in another manner, the cost of light at the end of the century was about one fiftieth that of candle light at the beginning of the century. One authority in computing the expense of lighting to the householder in a large city of this country has stated that coincident with an increase of 1700 per cent. in the amount of night lighting of an American family, in average circumstances, using gas for light, there has come a reduction in the cost of the year's lighting of 34 per cent. or approximately $7.50 per year; and that the cost of lighting per unit of light--the candle-hour--is now but 2.8 per cent. of what it was in the first half of the nineteenth century. No other necessity of household use has been so cheapened and improved during the last century. In general, the light-user has taken advantage of the decrease by increasing the amount of light used and the period during which it is used. In this manner the greatly diminished cost of light has been a marked sociological and economic influence. After Murdock made his first installation of gas-lighting in an industrial plant early in the nineteenth century, he published a comparison of the expense of operation with that of candle-lighting. He arrived at the costs of light equivalent to 1000 candle-hours as follows: 1000 candle-hours Gas-lighting at a rate of two hours per day $1.95 " " " " " three " " " 1.40 Candle-lighting 6.50 It is seen that the longer hours of burning reduce the cost of gas-lighting by reducing the percentage of overhead charges. There are no such factors in lighting by candles because the whole "installation" is consumed. This is an early example of which an authentic record is available. At the present time a certain amount of light obtained for $1.00 with efficient tungsten filament lamps, costs $2.00 if obtained from kerosene flames and about $50.00 if obtained by burning candles. In order to obtain the cost of an equivalent amount of light throughout the past century a great many factors must be considered. Obviously, the results obtained by various persons will differ owing to the unavoidable factor of judgment; however, the following list of approximate values will at least indicate the trend of the price of light throughout the century or more of rapid developments in light-production. A fair average of the retail values of fuels and of electrical energy and an average luminous efficiency of the light-sources involved have been used in making the computations. The figures apply particularly to this country. TABLE SHOWING THE APPROXIMATE TOTAL COST OF 1000 CANDLE-HOURS FOR VARIOUS PERIODS Per 1000 candle-hours 1800 to 1850, sperm-oil $2.40 tallow candle 5.00 1850 to 1865, kerosene 1.65 tallow candle 6.85 1865 to 1875, kerosene .75 tallow candle 6.25 gas, open-flame .90 1875 to 1885, kerosene .25 gas, open-flame .60 1885 to 1895, kerosene .15 gas, open-flame .40 1895 to 1915, gas mantle .07 carbon filament .38 metallized filament .28 tungsten filament (vacuum) .12 tungsten filament (gas-filled) .07 In these days the cost of living has claimed considerable attention and it is interesting to compare that of lighting. In the following table the price of food and of electric lighting are compared for twenty years preceding the recent war. The great disturbance due to the war is thereby eliminated from consideration, but it should be noted that since 1914 the price of food has greatly increased but that of electric lighting has not changed materially. The cost of each commodity is taken as one hundred units for the year 1894 but, of course, the actual cost of living for the householder is perhaps a hundred times greater than the cost of electric lighting. Year Food Electric lighting 1894 100 100 1896 80 92 1898 92 90 1900 100 85 1902 113 77 1904 110 77 1906 115 57 1908 128 30 1910 138 28 1912 144 23 1914 145 17 One feature of electric lighting which puzzles the consumer and which gives the politicians an opportunity for crying "discrimination" and "injustice" at the public-service company is the great variation in rates. There is no discrimination or injustice when the householder, for example, must pay more for his lighting than a factory pays. The rates are not only affected by "demand" but by the period in which the demand comes. Residence lighting is chiefly confined to certain hours from 5 to 9 P. M. and there is a great "peak" of demand at this time. The central-stations must have equipment available for this short-time demand and much of the capacity of the equipment is unused during the remainder of the day. The factory which uses electricity throughout the day or night or both is helping to keep the central-station operating efficiently. The equipment necessary to supply electricity to the factory is operating long hours. Not only is this overhead charge much less for factories and many other consumers than for the householder, but the expense of accounting, of reading meters, etc., is about the same for all classes of consumers. Therefore, this is an appreciable item on the bill of the small consumer. Doubtless, the public does not realize that the enormous decrease in the cost of lighting during the past century is due largely to the fact that the lighting industry has grown large. Increased production is responsible for some of this decrease and science for much of it. The latter, having been called to the aid of the manufacturers, who are better able by virtue of their magnitude to spend time and resources upon scientific developments, has responded with many improvements which have increased the efficiency of light-production. Some figures of the Census Bureau may be of interest. These are given for 1914 in order that the abnormal conditions due to the recent war may be avoided. The figures pertaining to the manufacture of gas for sale which do not include private plants are as follows for the year 1914 for this country: Number of establishments 1,284 Capital $1,252,421,584 Value of products (gas, coke, tar, etc.) $220,237,790 Cost of materials $76,779,288 Value added by manufacture $143,458,502 Value of gas $175,065,920 Coal used (tons) 6,116,672 Coke used (tons) 964,851 Oil used (gallons) 715,418,623 Length of gas mains (miles) 58,727 Manufactured products sold Total gas (cubic feet) 203,639,260,000 Straight coal gas (cubic feet) 10,509,946,000 Carbureted water gas (cubic feet) 90,017,725,000 Mixed coal- and water-gas (cubic feet) 86,281,339,000 Oil gas (cubic feet) 16,512,274,000 Acetylene (cubic feet) 136,564,000 Other gas, chiefly gasolene (cubic feet) 181,412,000 Coke (bushels) 114,091,753 Tar (gallons) 125,938,607 Ammonia liquors (gallons) 50,737,762 Ammonia, sulphate (pounds) 6,216,618 Of course, only a small fraction of the total gas manufactured is used for lighting. According to the U. S. Geological Survey, the quantities of gas sold in this country in the year 1917 were as follows: Coal-gas 42,927,728,000 cubic feet Water-gas 153,457,318,000 " " Oil-gas 14,739,508,000 " " Byproduct gas 131,026,575,000 " " Natural gas 795,110,376,000 " " In 1914 there were 38,705,496 barrels (each fifty gallons) of illuminating oils refined in this country and the value was $96,806,452. About half of this quantity was exported. In 1914 the value of all candles manufactured in this country was about $2,000,000, which was about half that of the candles manufactured in 1909 and in 1904. In 1914 the value of the matches manufactured in this country was $12,556,000. This has increased steadily from $429,000 in 1849. In 1914 the glass industries in this country made 7,000,000 lamps, 70,000,000 chimneys, 16,300,000 lantern globes, 24,000,000 shades, globes, and other gas goods. Many millions of other lighting accessories were made, but unfortunately they are not classified. Some figures pertaining to public electric light and power stations of the United States for the years 1907 and 1917 are as follows: 1917 1907 Number of establishments 6,541 4,714 Commercial 4,224 3,462 Municipal 2,317 1,562 Income $526,886,408 $175,642,338 Total horse-power of plants 12,857,998 4,098,188 Steam engines 8,389,389 2,693,273 Internal combustion engines 217,186 55,828 Water-wheels 4,251,423 1,349,087 Kilowatt capacity of generators 9,001,872 2,709,225 Output in millions of kilowatt-hours 25,438 5,863 Motors served (horse-power) 9,216,323 1,649,026 Electric-arc street-lamps served 256,838 .... Electric-filament street-lamps served 1,389,382 .... In general, there is a large increase in the various items during the decade represented. The output of the central stations doubled in the five years from 1907 to 1912, and doubled again in the next five years from 1912 to 1917. Street lamps were not reported in 1907, but in 1912 there were 348,643 arc-lamps served by the public companies. The number of arc-lamps decreased to 256,838 in 1917. On the other hand, there were 681,957 electric filament street lamps served in 1912, which doubled in number to 1,389,382 in 1917. The cost of construction and equipment of these central stations totaled more than $3,000,000,000 in 1917. Although there is no immediate prospect of the failure of the coal and oil supplies, exhaustion is surely approaching. And as the supplies of fuel for the production of gas and electricity diminish, the cost of lighting may advance. The total amount of oil available in the known oil-fields of this country at the present time has been estimated by various experts between 5,000,000,000 and 20,000,000,000 barrels, the best estimate being about 7,000,000,000. The annual consumption is now about 400,000,000 barrels. These figures do not take into account the oil which may be distilled from the rich shale deposits. Apparently this source will yield a hundred billion barrels of oil. In a similar manner the coal-supply is diminishing and the consumption is increasing. In 1918 more than a half-billion tons of coal were shipped from the mines. The production of natural gas perhaps has reached its peak, and, owing to its relation to the coal and oil deposits, its supply is limited. Although only a fraction of the total production of gas, oil, and coal is used in lighting, the limited supply of these products emphasizes the desirability of developing the enormous water-power resources of this country. The present generation will not be hard pressed by the diminution of the supply of gas, oil, and coal, but it can profit by encouraging and even demanding the development of water-power. Furthermore, it is an obligation to succeeding generations to harness the rivers and even the tides and waves in order that the other resources will be conserved as long as possible. Science will continue to produce more efficient light-sources, but the cost of light finally is dependent upon the cost of the energy supplied to these lamps. At the present time water-power is the anchor to the windward. XVII LIGHT AND SAFETY It is established that outdoors life and property are at night safer under adequate lighting than they are under inadequate lighting. Police departments in the large cities will testify that street-lighting is a powerful ally and that crime is fostered by darkness. But in reckoning the cost of street-lighting to-day how many take into account the value of safety to life and property and the saving occasioned by the reduction in the police-force necessary to patrol the cities and towns? Owing to the necessity of darkening the streets in order to reduce the hazards of air-raids, London experienced a great increase in accidents on the streets, which demonstrated the practical value of street-lighting from the standpoint of accident prevention. During the war, when dastardly traitors and agents of the enemy were striking at industry, the value of lighting was further recognized by the industries, with the result that flood-lighting was installed to protect them. By common consent this new phase was termed "protective lighting." Soon after the entrance of this country into the recent war, the U. S. Military Intelligence established a Section of Plant Protection which had thirty-three district offices during the war and gave attention to thirty-five thousand industrial plants engaged in production of war materials. Protective lighting was early recognized by this section as a very potential agency for defense, and extensive use was made of it. For example, Edmund Leigh, chief of the section, in discussing the value of outdoor lighting stated: An illustration of our work in this connection is the case of an $80,000,000 powder plant of recent construction. We arranged to have all wires buried. In addition to the ordinary lighting on an adjacent hill there is a large searchlight which will command any part of the buildings and grounds. Every three hundred yards there is a watch-tower with a searchlight on top. These searchlights are for use only in emergency. Each tower has a telephone service, one connected with the other. The men in the towers have a view of the building exteriors, which are all well lighted, and the men in the buildings look across the yard to the lighted fence line and so get a silhouette of persons or objects in between. The most vital parts of the buildings are surrounded by three fences. In the near-by woods the underbrush has been cleared out and destroyed. The trunks and limbs of trees have been whitewashed. No one can walk among these trees or between the trees and the plant without being seen in silhouette.... I say flatly that I know nothing that is so potential for good defense as good illumination and at the same time so little understood. Without such protective lighting an army of men would have been required to insure the safety of this one vital plant; still it is obvious that the cost of the protective lighting was an insignificant part of the value of the plant which it insured against damage and destruction. The United States participated for nineteen months in the recent war and during that time about 400,000 casualties were suffered by its forces. This was at the rate of about 250,000 per year, which included casualties in battle, at sea, and from sickness, wounds, and accidents. Every one has felt the magnitude of this rate of casualties because either his home or that of a friend was blighted by one or more of these tragedies in the nineteen months. However, R. E. Simpson of the Travelers Insurance Company has stated that: During a one-year period in this country the number of accidents due to inadequate or improper lighting exceeds the yearly rate of our war casualties. This is a startling comparison, which emphasizes a phase of lighting that has long been recognized by experts but has been generally ignored by the industries and by the public. The condition doubtless is due largely to a lag in the proper utilization of artificial lighting behind the rapid increase in congestion in the industries and in public places. Accident prevention is an important phase of modern life which must receive more attention. From published statistics and conservative estimates it has been concluded that there are approximately 25,000 persons killed or permanently disabled, 500,000 seriously injured, and 1,000,000 slightly injured each year in this country. Translating these figures by means of the accident severity rates, Mr. Simpson has found that there is a total of 180,000,000 days of time lost per year. This is equivalent to the loss of services of 600,000 men for a full year of 300 work-days. This loss is distributed over the entire country and consequently its magnitude is not demonstrated excepting by statistics. Of course, the causes of the accidents are numerous, but, among the means of prevention, proper lighting is important. According to some authorities at least 18 per cent. of these accidents are due to defects in lighting. On this basis the services of 108,000 men as producers and wage-earners are continually lost at the present time because the lighting is not sufficient or proper for the safety of workers. If the full year's labor of 108,000 men could be applied to the mining of coal, 130,000,000 million tons of coal would be added to the yearly output; and only 10,000 tons would be necessary to supply adequate lighting for this army of men working for a full year for ten hours each day. Statistics obtained under the British workmen's compensation system show that 25 per cent. of the accidents were caused by inadequate lighting of industrial plants. Much has been said and actually done regarding the saving of fuel by curtailing lighting, but the saving may easily be converted into a great loss. For example, a 25-watt electric lamp may be operated ten hours a day for a whole year at the expense of one eighth of a ton of coal. Suppose this lamp to be over a stairway or at any vital point and that by extinguishing it there occurs a single accident which involves the loss of only one day's work on the part of the worker. If this one day's time could have produced coal, there would have been enough coal mined in the ten hours to operate the lamp for thirty-two years. The insignificant cost of lighting is also shown by the distribution of the consumption of fuel for heating, cooking, and lighting in the home. Of the total amount of fuel consumed in the home for these purposes, 87 per cent. is for heating, 11 per cent. for cooking and 2 per cent. for lighting. The amount of coal used for lighting purposes in general is about 2.5 per cent. of the total consumption of coal, so it is seen that the curtailment of lighting at best cannot save much fuel; and it may actually result in a great economic loss. By replacing inefficient lamps and accessories with efficient lighting-equipment and by washing windows and artificial lighting devices, a real saving can be realized. Improper lighting may be as productive of accidents as inadequate lighting, and throughout the industries and upon the streets the misuse of light is in evidence. The blinding effect of a brilliant light-source is easily proved by looking at the sun. After a few moments great discomfort is experienced, and on looking away from this brilliant source the eyes are temporarily blinded by the after-images. When this happens in a factory as the result of gazing into an unshielded light-source, the workman may be injured by moving machinery, by stumbling over objects, and in many other ways. Unshaded light-sources are too prevalent in the industries. Improper lighting is likely to cause deep shadows wherein many dangers may be hidden. On the street the glare from automobile head-lamps is very prevalent and nearly everybody may testify from experience to the dangers of glare. Even the glaring locomotive head-lamp has been responsible for many casualties. Unfortunately, natural lighting outdoors has not been under the control of man and he has accepted it as it is. The sky is a harmless source of light when viewed outdoors and the sun is in such a position that it is usually easy to avoid looking at it. It is so intensely glaring that man unconsciously avoids looking directly at it. These conditions are responsible to an extent for man's indifference and even ignorance of the rudiments of safe lighting. When he has artificial light, over which he may exercise control, he either ignores it or owing to the less striking glare he misuses it and his eyesight without realizing it. A great deal of eye-strain and permanent eye trouble arises from the abuse of the eyes by improper lighting. For example, near-sightedness is often due to inadequate illumination, which makes it necessary for the eyes to be near the work or the reading-page. Improper or inadequate lighting especially influences eyes that are immature in growth and in function, and it has been shown that with improvements in lighting the percentage of short-sightedness has decreased in the schools. Furthermore, it has been shown that where no particular attention has been given to lighting and vision, the percentage of short-sightedness has increased with the grade. There are twenty million school children in this country whose future eyesight is in the hands of those who have jurisdiction over lighting and vision. There are more than a hundred million persons in this country whose eyes are daily subjected to improper lighting-conditions, either through their own indifference or through the negligence of others. Of a certain group of 91,000 purely industrial accidents in the year 1910, Mr. Simpson has stated that 23.8 per cent. were due, directly or indirectly, to the lack of proper illumination. These may be further divided into two approximately equal groups, one of which comprises the accidents due to inadequate illumination and the other to those toward which improper lighting was a contributing cause. The seasonal variation of these accidents is given in the following table, both for those due directly or indirectly to inadequate and improper lighting and those due to other causes. SEASONAL DISTRIBUTION OF INDUSTRIAL ACCIDENTS DUE TO LIGHTING CONDITIONS AND TO OTHER CAUSES Percentage due to Lighting conditions Other causes July 4.8 5.9 August 5.2 6.2 September 6.1 6.9 October 8.6 8.5 November 10.9 10.5 December 15.6 12.2 January 16.1 11.9 February 10.0 10.5 March 7.6 8.8 April 6.1 6.9 May 5.2 5.8 June 3.8 5.9 The figures in one column have no direct relation to those in the other; that is, each column must be considered by itself. It is seen from the foregoing that about half the number of the accidents due to poor illumination occurred in the months of November, December, January, and February. These are the months of inadequate illumination unless artificial lighting has been given special attention. The same general type of seasonal distribution of accidents due to other causes is seen to exist but not so prominently. The greatest monthly rate of accidents during the winter season is nearly four times the minimum monthly rate during the summer for those accidents due to lighting conditions. This ratio reduces to about twice in the case of accidents due to other causes. Looking at the data from another angle, it may be considered that the likelihood of an accident being caused by lighting conditions is about twice as great in any of the four "winter" months as in any of the remaining eight months. Doubtless, this may be explained largely upon the basis of morale. The winter months are more dreary than those of summer and the workman's general outlook is different in winter than in summer. In the former season he goes back and forth to work in the dark, or at best, in the cold twilight. He is not only more depressed but he is clumsier in his heavier clothing. If the enervating influence of these factors is combined with a greater clumsiness due to cold and perhaps to colds, it is not difficult to account for this type of seasonal distribution of accidents. A study of the accidents of 1917 indicated that 13 per cent. occurred between 5 and 6 P. M. when artificial lighting is generally in use to help out the failing daylight. Only 7.3 per cent. occurred between 12 M. and 1 P. M. [Illustration: SIGNAL-LIGHT FOR AIRPLANE] [Illustration: TRENCH LIGHT-SIGNALING OUTFIT] [Illustration: AVIATION FIELD LIGHT-SIGNAL PROJECTOR] [Illustration: SIGNAL SEARCH-LIGHT FOR AIRPLANE] [Illustration: UNSAFE, UNPRODUCTIVE LIGHTING WORTHY OF THE DARK AGES] [Illustration: THE SAME FACTORY MADE SAFE, CHEERFUL, AND MORE PRODUCTIVE BY MODERN LIGHTING] There is another aspect of the subject which deals particularly with the safety of the light-source or method of lighting. As each innovation in lighting appeared during the past century there immediately arose the question of safety. The fire-hazard of open flames received attention in early days, and when gas-lighting appeared it was condemned as a poison and an explosive. Mineral-oil lamps introduced the danger of explosions of the vapors produced by evaporation. When electric lighting appeared it was investigated thoroughly. The result of all this has been an effort to make lamps and methods safe. Insurance companies have the relative safety of these systems established to their satisfaction and to-day little fire-hazard is attached to the present modes of general lighting if proper precautions have been taken. When electric lighting was first introduced the public looked upon electricity as dangerous and naturally many questions pertaining to hazards arose. The distribution of electricity has been so highly perfected that little is heard of the hazards which were so magnified in the early years. Data gathered between 1884 and 1889 showed that about 13,000 fires took place in a certain district. Of these, 42 were attributed to electric wires; 22 times as many to breakage and explosion of kerosene lamps; and ten times as many through carelessness with matches. These figures cannot be taken at their face value because of the absence of data showing the relative amount of electric and kerosene lighting; nevertheless they are interesting because they represent the early period. There are industries where unusual care must be exercised in regard to the lighting. In certain chemical industries no lamps are used excepting the incandescent lamp and this is enclosed in an air-tight glass globe. Even a public-service gas company cautions its employees and patrons thus: "_Do not look for a gas-leak with a naked light! Use electric light._" The coal-mine offers an interesting example of the precautions necessary because the same type of problems are found in it as in industries in general, with the additional difficulties attending the presence or possible presence of explosive gas. The surroundings in a coal-mine reflect a small percentage of the light, so that much light is wasted unless the walls are whitewashed. This is a practical method for increasing safety in coal-mines. However, the most dangerous feature is the light-source itself. According to the Bureau of Mines during the years 1916 and 1917 about 60 per cent. of the fatalities due to gas and coal-dust explosions were directly traceable to the use of defective safety lamps and to open flames. In the early days of coal-mining it was found that the flame of a candle occasionally caused explosions in the mines. It was also found that sparks of flint and steel would not readily ignite the gas or coal-dust and this primitive device was used as a light-source. Of course, statistics are unavailable concerning the casualties in coal-mines throughout the past centuries, but with the accidents not uncommon in this scientific age, with its elaborate organizations striving to stamp out such casualties, there is good reason to believe that previous to a century or two ago the risks of coal-mining must have been great. Open flames have been widely used in this industry, but there has always been the risk of the presence or the appearance of gas or explosive dust. The early open-flame lamps not only were sources of danger but their feeble varying intensity caused serious damage to the eyesight of miners. This factor is always present in inadequate and improper lighting, but its influence is noticeable in coal-mining in the nervous disease affecting the eyes which is known as nystagmus. The symptoms of the disease are inability to see at night and the dazzling effect of ordinary lamps. Finally objects appear to the sufferer to dance about and his vision is generally very much disturbed. The oil-lamps used in coal-mining have a luminous intensity equivalent to about one to four candles, but owing to the atmospheric conditions in the mines a flame does not burn as brightly as in the fresh air. The possibility of explosion due to the open flame was eliminated by surrounding it with a metal gauze. Davy was the inventor of this device and his safety lamp introduced about a hundred years ago has been a boon to the coal-miner. Various improvements have been devised, but Davy's lamp contained the essentials of a safety device. The flame is surrounded by a cylinder of metal gauze which by forming a much cooler boundary prevents the mine-gas from becoming heated locally by the lamp flame to a sufficient temperature to ignite and consequently to explode. This device not only keeps the flame from igniting the gas but it also serves as an indicator of the amount of gas present, by the variation in the size and appearance of the tip of the flame. However, the gauze reduces the luminous output, and as it accumulates soot and dust the light is greatly diminished. One of these lamps is about as luminous as a candle, initially, but its intensity is often reduced by accumulations upon the gauze to only one fifth of the initial value. The acetylene lamp is the best open-flame light-source available to the miner, for several reasons. It is of a higher candle-power than the others and as it is a burning gas, there is not the danger of flying sparks as in the case of burning wicks. The greater intensity of illumination affords a greater safety to the miner by enabling him to detect loose rock which may be ready to fall upon him. However, this lamp may be a source of danger, owing to the fact that it will burn more brilliantly in a vitiated atmosphere than other flame-lamps. Another disadvantage is the possibility of calcium carbide accidentally spilt coming in contact with water and thereby causing the generation of acetylene gas. If this is produced in the mine in sufficient quantities it is a danger which may not be suspected. If ignited it will explode and may also cause severe burns. The electric lamp, being an enclosed light-source capable of being subdivided and fed by a small portable battery, early gave promise of solving the problem of a safe mine-lamp of adequate candle-power. Much ingenuity has been applied to the development of a portable electric safety mine-lamp, and several such lamps are now approved by the Bureau of Mines. Two general types are being manufactured, the cap outfit and the hand outfit. They consist essentially of a lamp in a reflector whose aperture is closed with a sheet or a lens of clear glass. The battery may be of the "dry" or "storage" type and in the case of the cap outfit the battery is carried on the back. The specifications for these lamps demand that a luminous intensity averaging at least 0.4 candle be maintained throughout twelve consecutive hours of operation. At no time during this period shall the output of light fall below 1.25 lumens for a cap-lamp and below 3 lumens for a hand-lamp. Inasmuch as these are equipped with reflectors, the specifications insist that a circle of light at least seven feet in diameter shall be cast on a wall twenty inches away. It appears that a portable lamp is an economic necessity in the coal-mines, on account of the expense, inconvenience, and possible dangers introduced by distribution systems such as are used in most places. Although the major defects in lighting are due to absence of light in dangerous places, to glare, and to other factors of improper lighting, there are many minor details which may contribute to safety. For example, low lamps are useful in making steps in theaters and in other places, in drawing attention to entrances of elevators, in lighting the aisles of Pullman cars, under hand-rails on stairways, and in many other vital places. A study of accidents indicates that simple expedients are effective preventives. XVIII THE COST OF LIVING A comparison of the civilization of the present with that of a century ago reveals a startling difference in the standards of living. To-day mankind enjoys conveniences and luxuries that were undreamed of by the past generations. For example, a certain town in Iowa, a score of years ago, was appraised for a bond-issue and it was necessary to extend its limits considerably in order to include a valuation of one half million dollars required by the underwriters. On a summer's evening at the present time a thousand "pleasure" automobiles may be found parked along its streets and these exceed in valuation that of the entire town only twenty years ago and equal it to-day. There are economists who would argue that the automobile has paid for itself by its usefulness, but the fact still exists that a great amount of labor has been diverted from producing food, clothing, and fuel to the production of "pleasure" automobiles. And this is the case with many other conveniences and luxuries. It is admitted that mankind deserves these refinements of modern civilization, but he must expect the cost of living to increase unless counteracting measures are taken. The economics of the increasing cost of living and the analysis of the relations of necessities, conveniences, and luxuries are too complex to be thoroughly discussed here. In fact, the most expert economists would disagree on many points. However, it is certain that the cost of living has steadily increased during the past century and it is reasonably certain that the standards of the present civilization are responsible for some if not all of the increase. Increased production is an anchor to the windward. It may drag and give way to some extent, but it will always oppose the course of the cost of living. When the first industrial plant was lighted by gas, early in the nineteenth century, the aim was merely to reinforce daylight toward the end of the day. Continuous operation of industrial plants was not practised in those days, excepting in a very few cases where it was essential. To-day some industries operate continuously, but most of them do not. In the latter case the consumer pays more for the product because the percentage of fixed or overhead charge is greater. Investment in ground, buildings, and equipment exacts its toll continuously and it is obvious that three successive shifts producing three times as much as a single day shift, or as much as a trebled day shift, will produce the less costly product. In the former case the fixed charge is distributed over the production of continuous operation, but in the latter case the production of a single day shift assumes the entire burden. Of course, there are many factors which enter into such a consideration and an important one is the desirability of working at night. It is not the intention to touch upon the psychological and sociological aspects but merely to look coldly upon the facts pertaining to artificial light and production. In the first place, it has been proved that in factories proper lighting as obtained by artificial means is generally more satisfactory than the natural lighting. Of course, a narrow building with windows on two sides or a one-story building with a saw-tooth roof of best design may be adequately illuminated by natural light, but these buildings are the exception and they will grow rarer as industrial districts become more congested. Artificial light may be controlled so that light of a satisfactory quality is properly directed and diffused. Sufficient intensities of illumination may be obtained and the failure of artificial light is a remote possibility as compared with the daily failure of natural light. With increasing cost of ground space, factories are built of several stories and with less space given to light courts, with the result that the ratio of window area to that of the floor is reduced. These tendencies militate against satisfactory daylighting. In the smoky congested industrial districts the period of effective daylight is gradually diminishing and artificial lighting is always essential at least as a reinforcement for daylight. It has been proved that proper artificial lighting--and there is no excuse for improper artificial lighting--is superior to most interior daylighting conditions. [Illustration: LOCOMOTIVE ELECTRIC HEADLIGHT] [Illustration: SEARCH-LIGHT ON A FIRE-BOAT] [Illustration: BUILDING SHIPS UNDER ARTIFICIAL LIGHT AT HOG ISLAND SHIPYARD] Although it is difficult to present figures in a brief discussion of this character, it may be stated that, in general, the cost of adequate artificial light is about 2 per cent. of the pay-roll of the workers; about 10 per cent. of the rental charges; and only a fraction of 1 per cent. of the cost of the manufactured products. These figures vary considerably, but they represent conservative average estimates. From these it is seen that artificial lighting is a small factor in adding to the cost of the product. But does artificial lighting add to the cost of a product? Many examples could be cited to prove that proper artificial lighting may be responsible for an actual reduction in the cost of the product. In a certain plant it was determined that the workmen each lost an appreciable part of an hour per day because of inadequate lighting. A properly designed and maintained lighting-system was installed and the saving in the wages previously lost, more than covered the operating-expense of the artificial lighting. Besides really costing the manufacturer less than nothing, the new artificial lighting system was responsible for better products, decreased spoilage, minimized accidents, and generally elevated spirits of the workmen. In some cases it is only necessary to save one minute per hour per workman to offset entirely the cost of lighting. The foregoing and many other examples illustrate the insignificance of the cost of lighting. The effectiveness of artificial lighting in reducing the cost of living is easily demonstrated by comparing the output of a factory operating on one and two shifts per day respectively. In a well-lighted factory which operated day and night shifts, the cost of adequate lighting was 7 cents per square foot per year. If this factory, operating only in the daytime, were to maintain the same output, it would be necessary to double its size. In order to show the economic value of artificial lighting it is only necessary to compare the cost of lighting with the rental charge of the addition and of its equipment. A fair rental value for plant and equipment is 50 cents per square foot per year; but of course this varies considerably, depending upon the type of plant and the character of the equipment. An investigation showed that this value varies usually between 30 to 70 cents per square foot per year. Using the mean value, 50 cents, it is seen that the rental charge is about seven times the cost of lighting. Furthermore, there is a saving of 43 cents per square foot per year during the night operation by operating the night shift. Of course, this is not strictly true because a depreciation of machinery during the night shift should be allowed for. These fixed charges would average slightly more than half as much in the case of the two-shift factory as in the case of the same output from a factory twice as large but operating only a day shift. Incidentally, the two-shift factory need not be a hardship for the workers, for, if the eight-hour shifts are properly arranged, the worker on the night shift may be in bed by midnight and the objection to a disturbance of ordinary hours of sleep is virtually eliminated. In a discussion of light and safety presented in another chapter the startling industrial losses due to accidents are shown to be due partially to inadequate or improper lighting. About one fourth of the total number of accidents may be charged to defective lighting. The consumer bears the burden of the support of an unproducing army of idle men. According to some experts an average of about 150,000 men are continuously idle in this country owing to inadequate and improper lighting. This is an appreciable factor in the cost of living, but the greatest effectiveness of artificial lighting in curtailing costs is to be found in reducing the fixed charges borne by the product through the operation of two shifts and by directly increasing production owing to improved lighting. The standard of artificial-lighting intensity possessed by the average person at the present time is an inheritance from the past. In those days when artificial light was much more costly than at present the tendency naturally was to use just as little light as necessary. That attitude could not have been severely criticized in those early days of artificial lighting, but it is inexcusable to-day. Eyesight and greater safety from accidents are in themselves valuable enough to warrant adequate lighting, but besides these there is the appeal of increased production. Outdoors on a clear summer day at noon the intensity of daylight illumination at the earth's surface is about 10,000 foot-candles; in other words, it is equal to the illumination on a surface produced by a light-source equivalent to 10,000 candles at a distance of one foot from the surface. This will be recognized as an enormous intensity of illumination. On a cloudy day the intensity of illumination at the earth's surface may be as high as 3000 foot-candles and on a "gloomy" day the illumination at the earth's surface may be 1000 foot-candles. When it is considered that mankind works under artificial light with an intensity of only a few foot-candles, the marvels of the visual apparatus are apparent. But it should be noted that the eyes of the human race evolved under natural light. They have been used to great intensities when called upon for their greatest efforts. The human being is wonderfully adaptive, but it could scarcely be hoped that the eyes could readjust themselves in a few generations to the changed conditions of low-intensity artificial lighting. There is no complaint against the range of intensities to which the eye responds, for in range of sensibility it is superior to any man-made device. For extremely low brightnesses another set of physiological processes come into play. Based purely upon the physiological laws of vision it seems reasonable to conclude that mankind should not work under artificial illumination as low as has been considered necessary owing to the cost in the past. With this principle of vision as a foundation, experiments have been made with greater intensities of illumination in the industries and elsewhere and increased production has been the result. In a test in a factory where an adequate record of production was in effect it was found that an increase in the intensity of illumination from 4 to 12 foot-candles increased the production in various operations. The lowest increase in production was 8 per cent., the highest was 27 per cent., and the average was 15 per cent. The original lighting in this case was better than that of the typical industrial conditions, so that it seems reasonable to expect a greater increase in production when a change is made from the average inadequate lighting of a factory to a well-designed lighting-system giving a high intensity of illumination. In another test the production under a poor system of lighting by means of bare lamps on drop-cords was compared with that of an excellent system in which well-designed reflectors were used. The intensity of illumination in the latter case was twenty-five times that of the former and the production was increased in various operations from 30 per cent. for the least increase to 100 per cent. for the greatest increase. Inasmuch as the energy consumption in the latter case was increased seven times and the illumination twenty-five times, it is seen that the increase in intensity of illumination was due largely to the use of proper reflectors and to the general layout of the new lighting-system. In another case a 10 per cent. increase in production was obtained by increasing the intensity of illumination from 3 foot-candles to about 12 foot-candles. This increase of four times in the intensity of illumination involved an increase in consumption of electrical energy of three times the original amount at an increase in cost equal to 1.2 per cent. of the pay-roll. In another test an increase of 10 per cent. in production was obtained at an increase in cost equal to less than 1 per cent. of the payroll. The efficiency of well-designed lighting installations is illustrated in this case, for the illumination intensity was increased six times by doubling the consumption of electrical energy. Various other tests could be cited, but these would merely emphasize the same results. However, it may be stated that the factory superintendents involved are convinced that adequate and proper artificial lighting is a great factor in increasing production. Mr. W. A. Durgin, who conducted the tests, has stated that the average result of increasing the intensity of illumination and of properly designing the lighting installations in factories will be at least a 15 per cent. increase in production at an increased cost of not more than 5 per cent. of the pay-roll. This is apparently a conservative statement. When it is considered that generally the cost of lighting is only a fraction of 1 per cent. of the cost of products to the consumer, it is seen that the additional cost of obtaining an increase of 15 per cent. in production is inappreciable. Industrial superintendents are just beginning to see the advantage of adequate artificial lighting, but the low standards of lighting which were inaugurated when artificial light was much more costly than it is to-day persist tenaciously. When high intensities of proper illumination are once tried, they invariably prove successful in the industries. Not only does the worker see all his operations better, but there appears to be an enlivening effect upon individuals under the higher intensities of illumination. Mankind chooses a dimly lighted room in which to rest and to dream. A room intensely lighted by means of well-designed units which are not glaring is comfortable but not conducive to quiet contemplation. It is a place in which to be active. This is perhaps one of the factors which makes for increased production under adequate lighting. Civilization has just passed the threshold of the age of adequate artificial lighting and only a small percentage of the industries have increased their lighting standards commensurately to the possibilities of the present time. If high-intensity artificial lighting was installed in all the industries and a 15 per cent. increase in production resulted, as tests appear to indicate, the increased production would be equal to that of nearly two million workers. This great increase in output is brought about by lighting at an insignificant increase in cost but without the additional consumption of food or clothing. Besides this increase in production there is the decrease in spoilage. The saving possible in this respect through adequate lighting has been estimated for the industries of this country at $100,000,000. If mankind is to have conveniences and luxuries, efficiency in production must be practised to the utmost and in the foregoing a proved means has been discussed. There are many other ways in which artificial light may serve in increasing production. Man has found that eight hours of sleep is sufficient to keep him fit for work if he has a sufficient amount of recreation. Before the advent of artificial light the activities of the primitive savage were halted by darkness. This may have been Nature's intention, but civilized man has adapted himself to the changed conditions brought about by efficient and adequate artificial light. There appears to be no fundamental reason for not imposing an artificial day upon plants, animals, chemical processes, etc.; and, in fact, experiments are being prosecuted in these directions. The hen, when permitted to follow her natural course, rises with the sun and goes to roost at sunset. During the winter months she puts in short days off the roost. It has been shown that an artificial day, made by piecing out daylight by means of artificial light, might keep the hen scratching and feeding longer, with an increased production of eggs as a result. Many experiments of this character have been carried out, and there appears to be a general conclusion that the use of artificial light for this purpose is profitable. Experiments conducted recently by the agricultural department of a large university indicate that in poultry husbandry, when artificial light is applied to the right kind of stock with correct methods of feeding, the distribution of egg-production throughout the whole year can be radically changed. The supply of eggs may be increased in autumn and winter and decreased in spring and summer. Data on the amount of illumination have not been published, but it is said that the most satisfactory results have been obtained when the artificial illumination is used from sunset until about 9 P. M. throughout the year. An increase of 30 to 40 per cent. in the number of eggs laid on a poultry-farm in England as the result of installing electric lamps in the hen-houses was reported in 1913. On this farm there were nearly 200 yards of hen-houses containing about 6000 hens, and the runs were lighted on dark mornings and early nights of the year preceding the report. About 300 small lamps varying from 8 to 32 candle-power were used in the houses. It was found that an imitation of sunset was necessary by switching off the 32 candle-power lamps at 6 P. M. and the 16 candle-power lamps at 9:30. This left only the 8 candle-power lamps burning, and in the faint illumination the hens sought the roosting-places. At 10 P. M. the remaining lights were extinguished. It was found that if all the lights were extinguished suddenly the fowls went to sleep on the ground and thus became a prey to parasites. The increase in production of eggs is brought about merely by keeping the fowls awake longer. On the same farm the growth of chicks incubated during the winter months increased by one third through the use of electric light which kept them feeding longer. Many fishermen will testify that artificial light seems to attract fish, and various reports have been circulated regarding the efficacy of using artificial light for this purpose on a commercial scale. One report which bears the earmarks of authenticity is from Italy, where it is said that electric lights were successfully used as "bait" to augment the supply of fish during the war. The lamps were submerged to a considerable depth and the fish were attracted in such large numbers that the use of artificial light was profitable. The claims made were that the supply of fish was not only increased by night fishing but that a number of fishermen were thereby released for national service during the war. An interesting incident pertaining to fish, but perhaps not an important factor in production, is the use of electric lights in the summer over the reservoirs of a fish hatchery. These lights, which hang low, attract myriads of bugs, many of which fall in the water and furnish natural and inexpensive food for the fish. Many experiments have been carried out in the forcing of plants by means of artificial light. Some of these were conducted forty years ago, when artificial light was more costly than at the present time. Of course, it is well known that light is essential to plant life and in general it is reasonable to believe that daylight is the most desirable quality of light for plants. In greenhouses the forcing of plants is desirable, owing to the restricted area for cultivation. It has been established that some of the ultra-violet rays which are absorbed or not transmitted by glass are harmful to growing plants. For this reason an arc-lamp designed for forcing purposes should be equipped with a glass globe. F. W. Rane reported in 1894 upon some experiments with electric carbon-filament lamps in greenhouses in which satisfactory results were obtained by using the artificial light several hours each night. Prof. L. H. Bailey also conducted experiments with the arc-lamp and concluded that there were beneficial results if the light was filtered through clear glass. Without considering the details of the experiment, we find some of Rane's conclusions of interest, especially when it is remembered that the carbon-filament lamps used at that time were of very low efficiency compared with the filament lamps at the present time. Some of his conclusions were as follows: The incandescent electric light has a marked effect upon greenhouse plants. The light appears to be beneficial to some plants grown for foliage, such as lettuce. The lettuce was earlier, weighed more and stood more erect. Flowering plants blossomed earlier and continued to bloom longer under the light. The light influences some plants, such as spinach and endive, to quickly run to seed, which is objectionable in forcing these plants for sale. The stronger the candle-power the more marked the results, other conditions being the same. Most plants tended toward a taller growth under the light. It is doubtful whether the incandescent light can be used in the greenhouse from a practical and economic standpoint on other plants than lettuce and perhaps flowering plants; and at present prices (1894) it is a question if it will pay to employ it even for these. There are many points about the incandescent electric light that appear to make it preferable to the arc light for greenhouse use. Although we have not yet thoroughly established the economy and practicability of the electric light upon plant growth, still I am convinced that there is a future in it. These are encouraging conclusions, considering the fact that the cost of light from incandescent lamps at the present time is only a small fraction of its cost at that time. In an experiment conducted in England in 1913 mercury glass-tube arcs were used in one part of a hothouse and the other part was reserved for a control test. The same kind of seeds were planted in the two parts of the hothouse and all conditions were maintained the same, excepting that a mercury-vapor lamp was operated a few hours in the evening in one of them. Miss Dudgeon, who conducted the test, was enthusiastic over the results obtained. Ordinary vegetable seeds and grains germinated in eight to thirteen days in the hothouse in which the artificial light was used to lengthen the day. In the other, germination took place in from twelve to fifty-seven days. In all cases at least several days were saved in germination and in some cases several weeks. Flowers also increased in foliage, and a 25 per cent. increase in the crop of strawberries was noted. Seedlings produced under the forcing by artificial light needed virtually no hardening before being planted in the open. Professor Priestley of Bristol University said of this work: The light seems to have been extraordinarily efficacious, producing accelerated germination, increased growth, greater depth of color, and more important still, no signs of lanky, unnatural extension of plant usually associated with forcing. Rather the plants exposed to the radiation seem to have grown if anything more sturdy than the control plants. A structural examination of the experimental and control plants carried out by means of the microscope fully confirmed Miss Dudgeon's statements both as to depth of color and greater sturdiness of the treated plants. Unfortunately there is much confusion amid the results of experiments pertaining to the effects of different rays, including ultra-violet, visible and infra-red, upon plant growth. If this aspect was thoroughly established, investigations could be outlined to greater advantage and efficient light-sources could be chosen with certainty. There is the discouraging feature that the average intensity of daylight illumination from sunrise to sunset in the summer-time is several thousand foot-candles. The cost of obtaining this great intensity by means of artificial light would be prohibitive. However, the daylight illumination in a greenhouse in winter is very much less than the intensity outdoors in summer. Indeed, this intensity perhaps averages only a few hundred foot-candles in winter. There is encouragement in this fact and there is hope that a little light is relatively much more effective than a great amount. Expressed in another manner, it is possible that a little light is much more effective than no light at all. Experiments with artificial light indicate very generally an increased growth. Recently Hayden and Steinmetz experimented with a plot of ground 5 feet by 9 feet, over which were hung five 500-watt gas-filled tungsten lamps 3 feet above the ground and 17 inches apart. The lamps were equipped with reflectors and the resulting illumination was 700 foot-candles. This is an extremely high intensity of artificial illumination and is comparable with daylight in greenhouses. The only seeds planted were those of string beans and two beds were carried through to maturity, one lighted by daylight only and the other by daylight and artificial light, the latter being in operation twenty-fours hours per day. The plants under the additional artificial light grew more rapidly than the others, and of the various records kept the gain in time was in all cases about 50 per cent. From the standpoint of profitableness the artificial lighting was not justified. However, there are several points to be brought out before considering this conclusion too seriously. First, it appears unwise to use the artificial light during the day; second, it appears possible that a few hours of artificial light in the evening would suffice for considerable forcing; third, it is possible that a much lower intensity of artificial light might be more effective per lumen than the great intensity used; fourth, it is quite possible that some other efficient light-source may be more effective in forcing the growth of plants. These and many other factors must be carefully determined before judgment can be passed on the efficacy of artificial light in reducing the cost of living in this direction. Certainly, artificial light has been shown to increase the growth of plants and it appears probable that future generations at least will find it profitable to use the efficient light-producers of the coming ages in this manner. Many other instances could be cited in which artificial light is very closely associated with the cost of living. Overseas shipment of fruit from the Canadian Northwest is responsible for a decided innovation in fruit-picking. In searching for a cause of rotting during shipment it was finally concluded that the temperature at the time of picking was the controlling factor. As a consequence, daytime was considered undesirable for picking and an electric company supplied electric lighting for the orchards in order that the picking might be done during the cool of night. This change is said to have remedied the situation. Cases of threshing and other agricultural operations being carried on at night are becoming more numerous. These are just the beginnings of artificial light in a new field or in a new relation to civilization. Its economic value has been demonstrated in the ordinary fields of lighting and these new applications are merely the initial skirmishes which precede the conquest of new territory. The modern illuminants have been developed so recently that the new possibilities have not yet been established. However, artificial light is already a factor on the side of the people in the struggle against the increasing cost of living, and its future in this direction is still more promising. XIX ARTIFICIAL LIGHT AND CHEMISTRY Some one in an early century was the first to notice that the sun's rays tanned the skin, and this unknown individual made the initial discovery in what is now an extensive branch of science known as photo-chemistry. The fading of dyes, the bleaching of textiles, the darkening of silver salts, the synthesis and decomposition of compounds are common examples of chemical reactions induced by light. There are thousands of other examples of the chemical effects of light some of which have been utilized by mankind. Others await the development of more efficient light-sources emitting greater quantities of active rays, and many still remain interesting scientific facts without any apparent practical applications at the present time. Visible and ultra-violet rays are the radiations almost entirely responsible for photochemical reactions, but the most active of these are the blue, violet, and ultra-violet rays. These are often designated chemical or actinic rays in order to distinguish the group as a whole from other groups such as ultra-violet, visible, and infra-red. Light is a unique agent in chemical reactions because it is not a material substance. It neither contaminates nor leaves a residue. Although much information pertaining to photochemistry has been available for years, the absence of powerful light-sources emitting so-called chemical rays in large quantities inhibited the practical development of the science of photochemistry. Even to-day, with vast applications of light in this manner, mankind is only beginning to utilize its chemical powers. [Illustration: In a moving-picture studio In a portrait studio ARTIFICIAL LIGHT IN PHOTOGRAPHY] [Illustration: Swimming pool City waterworks STERILIZING WATER WITH RADIANT ENERGY FROM QUARTZ MERCURY-ARCS] Although it appears that the chemical action of light was known to the ancients, the earliest photochemical investigations which could be considered scientific and systematic were those of K. W. Scheele in 1777 on silver salts. An extract from his own account is as follows: I precipitated a solution of silver by sal-ammoniac; then I edulcorated (washed) it and dried the precipitate and exposed it to the beams of the sun for two weeks; after which I stirred the powder and repeated the same several times. Hereupon I poured some caustic spirit of sal-ammoniac (strong ammonia) on this, in all appearance, black powder, and set it by for digestion. This menstruum (solvent) dissolved a quantity of luna cornua (horn silver), though some black powder remained undissolved. The powder having been washed was, for the greater part, dissolved by a pure acid of nitre (nitric acid), which, by the operation, acquired volatility. This solution I precipitated again by means of sal-ammoniac into horn silver. Hence it follows that the blackness which the luna cornua acquires from the sun's light, and likewise the solution of silver poured on chalk, is _silver by reduction_. I mixed so much of distilled water with the well-washed horn silver as would just cover this powder. The half of this mixture I poured into a white crystal phial, exposed it to the beams of the sun, and shook it several times each day; the other half I set in a dark place. After having exposed the one mixture during the space of two weeks, I filtrated the water standing over the horn silver, grown already black; I let some of this water fall by drops in a solution of silver, which was immediately precipitated into horn silver. This extract shows that Scheele dealt with the reducing action of light. He found that silver chloride was decomposed by light and that there was a liberation of chlorine. However, it was learned later that dried silver chloride sealed in a tube from which the air was exhausted is not discolored by light and that substances must be present to absorb the chlorine. Scheele's work aroused much interest in photochemical effects and many investigations followed. In many of these the superiority of blue, violet, and ultra-violet rays was demonstrated. In 1802 the first photograph was made by Wedgwood, who copied paintings upon glass and made profiles by casting shadows upon a sensitive chemical compound. However, he was not able to fix the image. Much study and experimentation were expended upon photochemical effects, especially with silver compounds, before Niepce developed a method of producing pictures which were subsequently unaffected by light. Later Daguerre became associated with Niepce and the famous daguerreotype was the result. Apparently the latter was chiefly responsible for the development of this first commercial process, the products of which are still to be found in the family album. A century has elapsed since this earliest period of commercial photography, and during each year progress has been made, until at the present time photography is thoroughly woven into the activities of civilized mankind. In those earliest years a person was obliged to sit motionless in the sun for minutes in order to have his picture taken. The development of a century is exemplified in the "snapshot" of the present time. Photographic exposures outdoors at present are commonly one thousandth of a second, and indoors under modern artificial light miles of "moving-picture" film are made daily in which the individual exposures are very small fractions of a second. Artificial light is playing a great part in this branch of photochemistry, and the development of artificial light for the various photographic needs is best emphasized by reminding the reader that the sources must be generally comparable with the sun in actinic or chemical power. The intensity of illumination due to sunlight on a clear day when the sun is near the zenith is commonly 10,000 foot-candles on a surface perpendicular to the direct rays. This is equivalent to the illumination due to a source 90,000 candle-power at a distance of three feet. The sun delivers about 200,000,000,000 horse-power to the earth continuously, which is estimated to be about one million times the amount of power generated artificially on the earth. Of this inconceivable quantity of energy a small part is absorbed by vegetation, some is reflected and radiated back into space, and the balance heats the earth. To store some of this energy so that it may be utilized at will in any desired form is one of the dreams of science. However, artificial light-sources are depended upon at present in many photographic and other chemical processes. Although two illuminants may be of the same luminous intensity, they may differ widely in actinic value. It is impossible to rate the different illuminants in a general manner as to actinic value because the various photochemical reactions are not affected to the same extent by rays of a given wave-length. Nearly all human eyes see visible rays in approximately the same manner, but the multitude of chemical reactions show a wide variation in sensitivity to the various rays. For example, one photographic emulsion may be sensitive only to ultra-violet, violet, and blue rays and another to all these rays and also to the green, yellow, and red. Therefore, one illuminant may be superior to another for one photochemical reaction, while the reverse may be true in the case of another reaction. In general, it may be said that the arc-lamps including the mercury-arcs provide the most active illuminants for photochemical processes; however, a large number of electric incandescent filament lamps are used in photographic work. The photo-engraver has been independent of sunlight since the practical development of his art. In fact, the printer could not depend upon sunlight for making the engravings which are used to illustrate the magazines and newspapers. The newspaper photographer may make a "flashlight" exposure, develop his negative, and make a print from it under artificial light. He may turn this over to the photo-engraver who carries out his work by means of powerful arc-lamps and in an hour or two after the original exposure was made the newspaper containing the illustration is being sold on the streets. The moving-picture studio is independent of daylight in indoor settings and there is a tendency toward the exclusive use of artificial light. In this field mercury-vapor lamps, arc-lamps, and tungsten photographic lamps are used. Similarly, in the portrait studio there is a tendency for the photographer to leave the skylighted upper floors and to utilize artificial light. In this field the tungsten photographic lamp is gaining in popularity, owing to its simplicity and to other advantages. Artificial light in general is more satisfactory than natural light for many kinds of photographic work because through the ease of controlling it a greater variety of more artistic effects may be obtained. In ordinary photographic printing tungsten lamps are widely used, but in blue-printing the white flame-arc and the mercury-vapor lamp are generally employed. Not many years ago the blue-printer waited for the sun to appear in order to make his prints, but to-day large machines operate continuously under the light of powerful artificial sources. How many realize that the blue-print is almost universally at the foundation of everything at the present time? Not only are products made from blue-prints but the machinery which makes the products is built from blue-prints. Even the building which houses the machinery is first constructed from blue-prints. They form an endless chain in the activities of present civilization. Artificial light has been a great factor in the practical development of photography and it is looked upon for aid in many other directions. Although there is a multitude of reactions in photographic processes which are brought about by exposure to light, these represent relatively few of the photochemical reactions. In general, it may be stated that light is capable of causing nearly every type of reaction. The chemical compounds which are photo-sensitive are very numerous. Many of the compounds of silver, gold, platinum, mercury, iron, copper, manganese, lead, nickel, and tin are photo-sensitive and these have been widely investigated. Light and oxygen cause many oxidation reactions and, on the other hand, light reduces many compounds such as silver salts, even to the extent of liberating the metal. Oxygen is converted partially into ozone under the influence of certain rays and there are many examples of polymerization caused by light. Various allotropic changes of the elements are due to the influence of light; for example, a sulphur soluble in carbon disulphide is converted into sulphur which is insoluble, and the rate of change of yellow phosphorus into the red variety is greatly accelerated by light. Hydrogen and chlorine combine under the action of light with explosive rapidity to form hydrochloric acid and there are many other examples of the synthesizing action of light. Carbon monoxide and chlorine combine to form phosgene and the combination of chlorine, bromine, and iodine, with organic compounds, is much hastened by exposing the mixture to light. In a similar manner many decompositions are due to light; for example, hydrogen peroxide is decomposed into water and oxygen. This suggests the reason for the use of brown bottles as containers for many chemical compounds. Such glass does not transmit appreciably the so-called actinic or chemical rays. There is a large number of reactions due to light in organic chemistry and one of fundamental importance to mankind is the effect of light on the chlorophyll, the green coloring matter in vegetation. No permanent change takes place in the chlorophyll, but by the action of light it enables the plant to absorb oxygen, carbon dioxide, and water and to use these to build up the complex organic substances which are found in plants. Radiant energy or light is absorbed and converted into chemical energy. This use of radiant energy occurs only in those parts of the plant in which chlorophyll is present, that is, in the leaves and stems. These parts absorb the radiant energy and take carbon dioxide from the air through breathing openings. They convert the radiant energy into chemical energy and use this energy in decomposing the carbon dioxide. The oxygen is exhausted and the carbon enters into the structure of the plant. The energy of plant life thus comes from radiant energy and with this aid the simple compounds, such as the carbon dioxide of the air and the phosphates and nitrates of the soil, are built into complex structures. Thus plants are constructive and synthetic in operation. It is interesting to note that the animal organism converts complex compounds into mechanical and heat energy. The animal organism depends upon the synthetic work of plants, consuming as food the complex structures built by them under the action of light. For example, plants inhale carbon dioxide, liberate the oxygen, and store the carbon in complex compounds, while the animal uses oxygen to burn up the complex compounds derived from plants and exhales carbon dioxide. It is a beautiful cycle, which shows that ultimately all life on earth depends upon light and other radiant energy associated with it. Contrary to most photochemical reactions, it appears that plant life utilize yellow, red, and infra-red energy more than the blue, violet, and ultra-violet. In general, great intensities of blue light and of the closely associated rays are necessary for most photochemical reactions with which man is industrially interested. It has been found that the white flame-arc excels other artificial light-sources in hastening the chlorination of natural gas in the production of chloroform. One advantage of the radiation from this light-source is that it does not extend far into the ultra-violet, for the ultra-violet rays of short wave-lengths decompose some compounds. In other words, it is necessary to choose radiation which is effective but which does not have rays associated with it that destroy the desired products of the reaction. By the use of a shunt across the arc the light can be gradually varied over a considerable range of intensity. Another advantage of the flame-arc in photochemistry is the ease with which the quality or spectral character of the radiant energy may be altered by varying the chemical salts used in the carbons. For example, strontium fluoride is used in the red flame-arc whose radiant energy is rich in red and yellow. Calcium fluoride is used in the carbons of the yellow flame-arc which emits excessive red and green rays causing by visual synthesis the yellow color. The radiant energy emitted by the snow-white flame-arc is a close approximation to average daylight both as to visible and to ultra-violet rays. Its carbons contain rare-earths. The uses of the flame-arcs are continually being extended because they are of high intensity and efficiency and they afford a variety of color or spectral quality. A million white flame-carbons are being used annually in this country for various photochemical processes. Of the hundreds of dyes and pigments available many are not permanent and until recent years sunlight was depended upon for testing the permanency of coloring materials. As a consequence such tests could not be carried out very systematically until a powerful artificial source of light resembling daylight was available. It appears that the white flame-arc is quite satisfactory in this field, for tests indicate that the chemical effect of this arc in causing dye-fading is four or five times as great as that of the best June sunlight if the materials are placed within ten inches of a 28-ampere arc. It has been computed that in several days of continuous operation of this arc the same fading results can be obtained as in a year's exposure to daylight in the northern part of this country. Inasmuch as the fastness of colors in daylight is usually of interest, the artificial illuminant used for color-fading should be spectrally similar to daylight. Apparently the white flame-arc fulfils this requirement as well as being a powerful source. Lithopone, a white pigment consisting of zinc sulphide and barium sulphate, sometimes exhibits the peculiar property of darkening on exposure to sunlight. This property is due to an impurity and apparently cannot be predicted by chemical analysis. During the cloudy days and winter months when powerful sunlight is unavailable, the manufacturer is in doubt as to the quality of his product and he needs an artificial light-source for testing it. In such a case the white flame-arc is serving satisfactorily, but it is not difficult to obtain effects with other light-sources in a short time if an image of the light-source is focused upon the material by means of a lens. In fact, a darkening of lithopone may be obtained in a minute by focusing upon it the image of a quartz mercury-arc by means of a quartz lens. In special cases of this sort the use of a focused image is far superior to the ordinary illumination from the light-source, but, of course, this is impracticable when testing a large number of samples simultaneously. Incidentally, lithopone which turns gray or nearly black in the sunlight regains its whiteness during the night. An amusing incident is told of a young man who painted his boat one night with a white paint in which lithopone was the pigment. On returning home the next afternoon after the boat had been exposed to sunlight all day, he was astonished to see that it was black. Being very much perturbed, he telephoned to the paint store, but the proprietor escaped a scathing lecture by having closed his shop at the usual hour. The young man telephoned in the morning and told the proprietor what had happened, but on being asked to make certain of the facts he went to the window and looked at his boat and behold! it was white. It had regained whiteness during the night but would turn black again during the day. Although pigments and dyes are not generally as peculiar as lithopone, much uncertainty is eliminated by systematic tests under constant, continuous, and controllable artificial light. The sources of so-called chemical rays are numerous for laboratory work, but there is a need for highly efficient powerful producers of this kind of energy. In general the flame-arcs perhaps are foremost sources at the present time, with other kinds of carbon arcs and the quartz mercury-arc ranking next. One advantage of the mercury-arc is its constancy. Furthermore, for work with a single wave-length it is easy to isolate one of the spectral lines. The regular glass-tube mercury-arc is an efficient producer of the actinic rays and as a consequence has been extensively used in photographic work and in other photochemical processes. An excellent source for experimental work can be made easily by producing an arc between two small iron rods. The electric spark has served in much experimental work, but the total radiant energy from it is small. By varying the metals used for electrodes a considerable variety in the radiant energy is possible. This is also true of the electric arcs, and the flame-arcs may be varied widely by using different chemical compounds in the carbons. There are other effects of light which have found applications but not in chemical reactions. For example, selenium changes its electrical resistance under the influence of light and many applications of this phenomenon have been made. Another group of light-effects forms a branch of science known as photo-electricity. If a spark-gap is illuminated by ultra-violet rays, the resistance of the gap is diminished. If an insulated zinc plate is illuminated by ultra-violet or violet rays, it will gradually become positively charged. These effects are due to the emission of electrons from the metal. Violet and ultra-violet rays will cause a colorless glass containing manganese to assume a pinkish color. The latter is the color which manganese imparts to glass and under the influence of these rays the color is augmented. Certain ultra-violet rays also ionize the air and cause the formation of ozone. This can be detected near a quartz mercury-arc, for example, by the characteristic odor. The foregoing are only a few of the multitude of photochemical reactions and other effects of radiant energy. The development of this field awaits to some extent the production of so-called actinic rays more efficiently and in greater quantities, but there are now many practical applications of artificial light for these purposes. In the extensive fields of photography various artificial light-sources have served for many years and they are constantly finding more applications. Artificial light is now used to a considerable extent in the industries in connection with chemical processes, but little information is available, owing to the secrecy attending these new developments in industrial processes. However, this brief chapter has been introduced in order to indicate another field of activity in which artificial light is serving. It is agreed by scientists that photochemistry has a promising future. Mankind harnesses nature's forces and produces light and this light is put to work to exert its influence for the further benefit of mankind. Science has been at work systematically for only a century, but the accomplishments have been so wonderful that the imagination dares not attempt to prophesy the achievements of the next century. XX LIGHT AND HEALTH The human being evolved without clothing and the body was bathed with light throughout the day, but civilization has gone to the other extreme of covering the body with clothing which keeps most of it in darkness. Inasmuch as light and the invisible radiant energy which is associated with it are known to be very influential agencies in a multitude of ways, the question arises: Has this shielding of the body had any marked influence upon the human organism? Although there is a vast literature upon the subject of light-therapy, the question remains unanswered, owing to the conflicting results and the absence of standardization of experimental details. In fact, most investigations are subject to the criticism that the data are inadequate. Throughout many centuries light has been credited with various influences upon physiological processes and upon the mind. But most of the early applications had no foundation of scientific facts. Unfortunately, many of the claims pertaining to the physiological and psychological effects of light at the present time are conflicting and they do not rest upon an established scientific foundation. Furthermore some of them are at variance with the possibilities and an unprejudiced observer must conclude that much systematic work must be done before order may arise from the present chaos. This does not mean that many of the effects are not real, for radiant energy is known to cause certain effects, and viewing the subject broadly it appears that light is already serving humanity in this field and that its future is promising. The present lack of definite data pertaining to the effects of radiation is due to the failure of most investigators to determine accurately the quantities and wave-lengths of the rays involved. For example, it is easy to err by attributing an effect to visible rays when the effect may be caused by accompanying invisible rays. Furthermore, it may be possible that certain rays counteract or aid the effective rays without being effective alone. In other words, the physical measurements have been neglected notwithstanding the fact that they are generally more easily made than the determinations of curative effects or of germicidal action. Radiant energy of all kinds and wave-lengths has played a part in therapeutics, so it is of interest to indicate them according to wave-length or frequency. These groups vary in range of wave-length, but the actual intervals are not particularly of interest here. Beginning with radiant energy of highest frequencies of vibration and shortest wave-lengths, the following groups and subgroups are given in their order of increasing wave-length: Röntgen or X-rays, which pass readily through many substances opaque to ordinary light-rays. Ultra-violet rays, which are divided empirically into three groups, designated as "extreme," "middle," and "near" in accordance with their location in respect to the visible region. Visible rays producing various sensations of color, such as violet, blue, green, yellow, orange, and red. Infra-red or the invisible rays bordering on the red rays. An unknown, unmeasured, or unfilled region between the infra-red and the "electric" waves. Electric waves, which include a class of electromagnetic radiant energy of long wave-length. Of these the Herzian waves are of the shortest wave-length and these are followed by "wireless" waves. Electric waves of still greater wave-length are due to the slower oscillations in certain electric circuits caused by lightning discharges, etc. The Röntgen rays were discovered by Röntgen in 1896 and they have been studied and applied very widely ever since. Their great use has been in X-ray photography, but they are also being used in therapeutics. The extreme ultra-violet rays are not available in sunlight and are available only near a source rich in ultra-violet rays, such as the arc-lamps. They are absorbed by air, so that they are studied in a vacuum. These are the rays which convert oxygen into ozone because the former strongly absorbs them. The middle ultra-violet rays are not found in sunlight, because they are absorbed by the atmosphere. They are also absorbed by ordinary glass but are freely transmitted by quartz. The nearer ultra-violet rays are found in sunlight and in most artificial illuminants and are transmitted by ordinary glass. Next to this region is the visible spectrum with the various colors, from violet to red, induced by radiant energy of increasing wave-length. The infra-red rays are sometimes called heat-rays, but all radiant energy may be converted into heat. Various substances transmit and absorb these rays in general quite differently from the visible rays. Water is opaque to most of the infra-red rays. Next there is a region of wave-lengths or frequencies for which no radiant energy has been found. The so-called electric waves vary in wave-length over a great range and they include those employed in wireless telegraphy. All these radiations are of the same general character, consisting of electromagnetic energy, but differing in wave-length or frequency of vibration and also in their effects. In effect they may overlap in many cases and the whole is a chaos if the physical details of quantity and wave-length are not specified in experimental work. [Illustration: In art work In a haberdashery JUDGING COLOR UNDER ARTIFICIAL DAYLIGHT] [Illustration: In an underground tunnel In an art gallery ARTIFICIAL DAYLIGHT] It has been conclusively shown that radiant energy kills bacteria. The early experiments were made with sunlight and the destruction of micro-organisms is generally attributed to the so-called chemical rays, namely, the blue, violet, and ultra-violet rays. It appears in general that the middle ultra-violet rays are the most powerful destroyers. It is certainly established that sunlight sterilizes water, for example, and the quartz mercury-lamp is in daily use for this purpose on a practicable scale. However, there still appears to be a difference of opinion as to the destructive effect of radiant energy upon bacteria in living tissue. It has been shown that the middle ultra-violet rays destroy animal tissue and, for example, cause eye-cataracts. It appears possible from some experiments that ultra-violet rays destroy bacteria in water and on culture plates more effectively in the absence of visible rays than when these attend the ultra-violet rays as in the case of sunlight. This is one of the reasons for the use of blue glass in light-therapy, which isolates the blue, violet, and near ultra-violet rays from the other visible rays. If the infra-red rays are not desired they can be readily eliminated by the use of a water-cell. There is a vast amount of testimony which proves the bactericidal action of light. Bacteria on the surface of the body are destroyed by ultra-violet rays. Typhus and tubercle bacilli are destroyed equally well by the direct rays from the sun and from the electric arcs. Cultures of diphtheria develop in diffused daylight but are destroyed by direct sunlight. Lower organisms in water are readily killed by the radiation from any light-source emitting ultra-violet rays comparable with those in direct sunlight. From the great amount of data available it appears reasonable to conclude that radiant energy is a powerful bactericidal agency but that the action is due chiefly to ultra-violet rays. It appears also that no bacteria can resist these rays if they are intense enough and are permitted to play upon the bacteria long enough. The destruction of these organisms appears to be a phenomenon of oxidation, for the presence of oxygen appears to be necessary. The foregoing remarks about the bactericidal action of radiant energy apply only to bacteria in water, in cultures, and on the surface of the body. There is much uncertainty as to the ability of radiant energy to destroy bacteria within living tissue. The active rays cannot penetrate appreciably into such tissue and many authorities are convinced that no direct destruction takes place. In fact, it has been stated that the so-called chemical rays are more destructive to the tissue cells than to bacteria. Finsen, a pioneer in the use of radiant energy in the treatment of disease, effected many wonderful cures and believed that the bacteria were directly destroyed by the ultra-violet rays. However, many have since come to the conclusion that the beneficent action of the rays is due to the irritation which causes an outflow of serum, thus bringing more antibodies in contact with the bacilli, and causing the destruction of the latter. Hot applications appear to work in the same manner. Primitive beings of the tropics are known to treat open wounds by exposing them to the direct rays of the sun without dressings of any kind. These wounds are usually infected and the sun's rays render them aseptic and they heal readily. Many cases of sores and surgical wounds have been quickly healed by exposure to sunlight. Even red light has been effective, so it has been concluded by some that rays of almost any wave-length, if intense enough, will effect a cure of this character by causing an effusion of serum. It has also been stated that the chemical rays have anæsthetic powers and have been used in this rôle for many minor operations. It is said that the Chinese have used red light for centuries in the treatment of smallpox and throughout the Middle Ages this practice was not uncommon. In the oldest book on medicine written in English there is an account of a successful treatment of the son of Edward I for smallpox by means of red light. It is also stated that this treatment was administered throughout the reigns of Elizabeth and of Charles II. Another account states that a few soldiers confined in dark dungeons recovered from smallpox without pitting. Finsen also obtained excellent results in the treatment of this disease by means of red light. However, in this case it appears that the exclusion of the so-called chemical rays favors healing of the postules of smallpox and that the use of red light is therefore a negative application of light-therapy. In other words, the red light plays no part except in furnishing a light which does not inhibit healing. Although the so-called actinic rays have curative value in certain cases, there are some instances where light-baths are claimed to be harmful. It is said that sun-baths to the naked body are not so popular as they were formerly, except for obesity, gout, rheumatism, and sluggish metabolism, because it is felt that the shorter ultra-violet rays may be harmful. These rays are said to increase the pulse, respiration, temperature, and blood-pressure and may even start hemorrhages and in excessive amounts cause headache, palpitation, insomnia, and anemia. These same authorities condemn sun-baths to the naked body of the tuberculous, claiming that any cures effected are consummated despite the injury done by the energy of short wave-length. There is no doubt that these rays are beneficial in local lesions, but it is believed that the cure is due to the irritation caused by the rays and the consequent bactericidal action of the increased flow of serum, and not to any direct beneficial result on the tissue-cells. Others claim to cure tuberculosis by means of powerful quartz mercury-arcs equipped with a glass which absorbs the ultra-violet rays of shorter wave-lengths. These conclusions by a few authorities are submitted for what they are worth and to show that this phase of light-therapy is also unsettled. Any one who has been in touch with light-therapy in a scientific rôle is bound to note that much ignorance is displayed in the use of light in this manner. In fact, it appears safe to state that light-therapy often smacks of quackery. Very mysterious effects are sometimes attributed to radiant energy, which occasionally border upon superstition. Nevertheless, this kind of energy has value, and notwithstanding the chaos which still exists, it is of interest to note some of the equipment which has been used. Some practitioners have great confidence in the electric bath, and elaborate light-baths have been devised. In the earlier years of this kind of treatment the electric arc was conspicuous. Electrodes of carbon, carbon and iron, and iron have been used when intense ultra-violet rays were desired. The quartz mercury-arc of later years supplies this need admirably. Dr. Cleaves, after many years of experience with the electric-arc bath, has stated: From the administration of an electric-arc bath there is obtained an action upon the skin, the patient experiences a pleasant and slightly prickly sensation. There is produced, even from a short exposure, upon the skin of some patients a slight erythema, while with others there is but little such effect even from long exposures. The face assumes a normal rosy coloring and an appearance of refreshment and repose on emerging from the bath is always observed. From the administration of the electric-arc bath there is also noted the establishment of circulatory changes with a uniform regulation of the heart's action, as evidenced by improved volume and slower pulse rate, the augmentation of the temperature, increased activity of the skin, fuller and slower respiration, gradually increased respiratory capacity, and diminished irritability of the mucous membrane in tubercular, bronchitic, or asthmatic patients. There is also lessened discharge in those patients suffering from catarrhal conditions of the nasal passages. In diseases of the respiratory system, a soothing effect upon the mucous membranes is always experienced, while cough and expectoration are diminished. The cabinet used by Dr. Cleaves was large enough to contain a cot upon which the patient reclined. An arc-lamp was suspended at each of the two ends of the cabinet and a flood of light was obtained directly and by reflection from the white inside surfaces of the cabinet. By means of mirrors the light from the arcs could be concentrated upon any desired part of the patient. Finsen, who in 1895 published his observations upon the stimulating action of light, is considered the pioneer in the use of so-called chemical rays in the treatment of disease. He had a circular room about thirty-seven feet in diameter, in which two powerful 100-ampere arc-lamps about six feet from the floor were suspended from the ceiling. Low partitions extended radially from the center, so that a number of patients could be treated simultaneously. The temperature of the room was normal, so that the treatment was essentially by radiant energy and not by heat. The chemical action upon the skin was said to be quite as strong as under sunlight. The exposures varied from ten minutes to an hour. Light-baths containing incandescent filament lamps are also used. In some cases the lamp, sometimes having a blue bulb, is merely contained as a reflector and the light is applied locally as desired. Light-cabinets are also used, but in these there is considerable effect due to heat. The ultra-violet rays emitted by the small electric filament lamps used in these cabinets are of very low intensity and the bactericidal action of the light must be feeble. The glass bulbs do not transmit the extreme ultra-violet rays responsible for the production of ozone, or the middle ultra-violet rays which are effective in destroying animal tissue. The cabinets contain from twenty to one hundred incandescent filament lamps of the ordinary sizes, from 25 to 60 watts. In the days of the carbon filament lamp the 16-candle-power lamp was used. Certainly the heating effect has advantages in some cases over other methods of heating. The light-rays penetrate the tissue and are absorbed and transformed into heat. Other methods involve conduction of heat from the hot air or other hot applications. Of course, it is also contended that the light-rays are directly beneficial. Light is also concentrated upon the body by means of lenses and mirrors. For this purpose the sun, the arc, the quartz mercury-arc, and the incandescent lamp have been used. Besides these, vacuum-tube discharges and sparks have been utilized as sources for radiant energy and "electrical" treatment. Röntgen rays and radium have also figured in recent years in the treatment of disease. The quartz mercury-arc has been extensively used in the past decade for the treatment of skin diseases and there appears to be less uncertainty about the efficacy of radiant energy for the treatment of surface diseases than of others. Herod related that the Egyptians treated patients by exposure to direct sunlight and throughout the centuries and among all types of civilization sunlight has been recognized as having certain valuable healing or purifying properties. Finsen in his early experiments cured a case of lupus, a tuberculous skin disease, by means of the visible and near ultra-violet rays in sunlight. He demonstrated that these were the effective rays by using only the radiant energy which passed through a water-cell made by using a convex lens for each end of the cell and filling the intervening space with water. This was really a lens made of glass and water. The glass absorbed the ultra-violet rays of shorter wave-length and the water absorbed the infra-red rays. Thus he was able to concentrate upon the diseased skin radiant energy consisting of visible and near ultra-violet rays. The encouraging results which Finsen obtained in the treatment of skin diseases led him to become independent of sunlight by equipping a special arc-lamp with quartz lenses. This gave him a powerful source of so-called chemical rays, which could be concentrated wherever desired. However, when science contributed the mercury-vapor arc, developments were immediately begun which aimed to utilize this artificial source of steady powerful ultra-violet rays in light-therapy. As a consequence, there are now available very compact quartz mercury-arcs designed especially for this purpose. Apparently their use has been very effective in curing many skin diseases. Certainly if radiant energy is effective, it has a great advantage over drugs. An authority has stated in regard to skin diseases that, treatment with the ultra-violet rays, especially in conjunction with the Röntgen rays, radium and mesothorium is that treatment which in most instances holds rank as the first, and in many as the only and often enough the most effective mode of handling the disease. Sterilization by means of the radiation from the quartz mercury-arc has been practised successfully for several years. Compact apparatus is in use for the sterilization of water for drinking, for surgical purposes, and for swimming-pools, and the claims made by the manufacturers of the apparatus apparently are substantiated. One type of apparatus withstands a pressure of one hundred pounds per square inch and may be connected in series with the water-main. The water supplied to the sterilizer should be clear and free of suspended matter, in order that the radiant energy may be effective. Such apparatus is capable of sterilizing any quantity of water up to a thousand gallons an hour, and the lamp is kept burning only when the water is flowing. It is especially useful in hotels, stores, factories, on ships, and in many industries where sterile water is needed. Water is a vital necessity in every-day life, whether for drinking, cooking, or industrial purposes. It is recognized as a carrier of disease and the purification of water-supply in large cities is an important problem. Chlorination processes are in use which render the treated water disagreeable to the taste and filtration alone is looked upon with suspicion. The use of chemicals requires constant analysis, but it is contended that the bactericidal action of ultra-violet rays is so certain and complete that there is never any doubt as to the sterilization of the water if it is clear, or if it has been properly filtered before treating. The system of sterilization by ultra-violet rays is the natural way, for the sun's rays perform this function in nature. Apparatus for sterilization of water by means of ultra-violet rays is built for public plants in capacities up to ten million gallons per day and these units may be multiplied to meet the needs of the largest cities. Large mechanical filters are used in conjunction with these sterilizers, and thus mankind copies nature's way, for natural supplies of pure water have been filtered through sand and have been exposed to the rays of the sun which free it from germ life. Some sterilizers of this character are used at the place where a supply of pure water is desired or at a point where water is bottled for use in various parts of a factory, hospital, store, or office building. These were used in some American hospitals during the recent war, where they supplied sterilized water for drinking and for the antiseptic bathing of wounds. In warfare the water supply is exceedingly important. For example, the Japanese in their campaign in Manchuria boiled the water to be used for drinking purposes. The mortality of armies in many previous wars was often much greater from preventable diseases than from bullets, but the Japanese in their war with Russia reversed the mortality statistics. Of a total mortality of 81,000 more than 60,000 died of casualties in battle. The sterilization of water for swimming-pools is coming into vogue. Heretofore it was the common practice to circulate the water through a filter, in order to remove the impurities imparted to it by the bathers and to return it to the pool. It is insisted by the adherents of sterilization that filtration of this sort is likely to leave harmful bacteria in the water. Sterilizers in which ultra-violet rays are the active rays are now in use for this purpose, being connected beyond the outflow from the filter. The effectiveness of the apparatus has been established by the usual method of counting the bacteria. Near the outlet of the ordinary filter a count revealed many thousand bacteria per cubic inch of water and among these there were bacteria of intestinal origin. Then a sterilizer was installed in which the effective elements were two quartz mercury-lamps which consumed 2.2 amperes each at 220 volts. A count of bacteria in the water leaving the sterilizer showed that these organisms had been reduced to 5 per cent. and finally to a smaller percentage of their original value, and that all those of intestinal origin had been destroyed. In fact, the water which was returned to the pool was better than that which most persons drink. Radiant energy possesses advantages which are unequaled by other bactericidal agents, in that it does not contaminate or change the properties of the water in any way. It does its work of destroying bacteria and leaves the water otherwise unchanged. These glimpses of the use of the radiant energy as a means of regaining and retaining good health suggest greater possibilities when the facts become thoroughly established and correlated. The sun is of primary importance to mankind, but it serves in so many ways that it is naturally a compromise. It cannot supply just the desired radiant energy for one purpose and at the same time serve for another purpose in the best manner. It is obscured on cloudy days and disappears nightly. These absences are beneficial to some processes, but man in the highly organized activity of present civilization desires radiant energy of various qualities available at any time. In this respect artificial light is superior to the sun and is being improved continually. XXI MODIFYING ARTIFICIAL LIGHT In a single century science has converted the dimly lighted nights with their feeble flickering flames into artificial daytime. In this brief span of years the production of light has advanced far from the primitive flames in use at the beginning of the nineteenth century, but, as has been noted in another chapter, great improvements in light-production are still possible. Nevertheless, the wonderful developments in the last four decades, which created the arc-lamps, the gas-mantle, the mercury-vapor lamps, and the series of electric incandescent-filament lamps, have contributed much to the efficiency, safety, health, and happiness of mankind. A hundred years ago civilization was more easily satisfied and an improvement which furnished more light at the same cost was all that could be desired. To-day light alone is not sufficient. Certain kinds of radiant energy are required for photography and other photochemical processes and a vast array of colored light is demanded for displays and for effects upon the stage. Man now desires lights of various colors for their expressive effects. He is no longer satisfied with mere light in adequate quantities; he desires certain qualities. Furthermore, he no longer finds it sufficient to be independent of daylight merely in quantity of light. In fact, he has demanded artificial daylight. Doubtless the future will see the production of efficient light of many qualities or colors, but to-day many of the demands must be met by modifying the artificial illuminants which are available. Vision is accomplished entirely by the distinction of brightness and color. An image of any scene or any object is focused upon the retina as a miniature map in light, shade, and color. Although the distinction of brightness is a more important function in vision than the ability to distinguish colors, color-vision is far more important in daily life than is ordinarily appreciated. One may go through life color-blind without suffering any great inconvenience, but the divine gift of color-vision casts a magical drapery over all creation. Relatively few are conscious of the wonderful drapery of color, except for occasional moments when the display is unusual. Nevertheless a study of vision in nearly all crafts reveals the fact that the distinction of colors plays an important part. In the purchase of food and wearing-apparel, in the decoration of homes and throughout the arts and industries, mankind depends a great deal upon the appearance of colors. He depends upon daylight in this respect and unconsciously often, when daylight fails, ceases work which depends upon the accurate distinction of colors. His color-vision evolved under daylight; arts and industries developed under daylight; and all his associations of color are based primarily upon daylight. For these reasons, adequate artificial illumination does not make mankind independent of daylight in the practice of arts and crafts and in many minor activities. In quality or spectral character, the unmodified illuminants used for general lighting purposes differ from daylight and therefore do not fully replace it. Noon sunlight contains all the spectral colors in approximately the same proportions, but this is not true of these artificial illuminants. For these reasons there is a demand for artificial daylight. The "vacuum" tube affords a possibility of an extensive variety of illuminants differing widely in spectral character or color. Every gas when excited to luminescence by an electric discharge in the "vacuum" tube (containing the gas at a low pressure) emits light of a characteristic quality or color. By varying the gas a variety of illuminants can be obtained, but this means of light-production has not been developed to a sufficiently practicable state to be satisfactory for general lighting. Nitrogen yields a pinkish light and the nitrogen tube as developed by Dr. Moore was installed to some extent a few years ago. Neon yields an orange light and has been used in a few cases for displays. Carbon dioxide furnishes a white light similar to daylight and small tubes containing this gas are in use to-day where accurate discrimination of color is essential. The flame-arcs afford a means of obtaining a variety of illuminants differing in spectral character or color. By impregnating the carbons with various chemical compounds the color of the flame can be widely altered. The white flame-arc obtained by the use of rare-earth compounds in the carbons provides an illuminant closely approximating average daylight. By using various substances besides carbon for the electrodes, illuminants differing in spectral character can be obtained. These are usually rich in ultra-violet rays and therefore have their best applications in processes demanding this kind of radiant energy. The arc-lamp is limited in its application by its unsteadiness, its bulkiness, and the impracticability of subdividing it into light-sources of a great range of luminous intensities. The most extensive applications of artificial daylight have been made by means of the electric incandescent filament lamp, equipped with a colored glass which alters the light to the same quality as daylight. The light from the electric filament lamp is richer in yellow, orange, and red rays than daylight, and by knowing the spectral character of the two illuminants and the spectral characteristics of colored glasses in which various chemicals have been incorporated, it is possible to develop a colored glass which will filter out of the excess of yellow, orange, and red rays so that the transmitted light is of the same spectral character as daylight. Thousands of such artificial daylight units are now in use in the industries, in stores, in laboratories, in dye-works, in print-shops, and in many other places. Currency and Liberty Bonds have been made under artificial daylight and such units are in use in banks for the detection of counterfeit currency. The diamond expert detects the color of jewels and the microscopist is certain of the colors of his stains under artificial daylight. The dyer mixes his dyes for the coloring of tons of valuable silk and the artist paints under this artificial light. These are only a few of a vast number of applications of artificial daylight, but they illustrate that mankind is independent of natural light in another respect. There are various kinds of daylight, two of which are fairly constant in spectral character. These are noon sunlight and north skylight. The former may be said to be white light and its spectrum indicates the presence of visible radiant energy of all wave-lengths in approximately equal proportions. North skylight contains an excess of violet, blue, and blue-green rays and as a consequence is a bluish white. Noon sunlight on a clear day is fairly constant in spectral character, but north skylight varies somewhat depending upon the absence or presence of clouds and upon the character of the clouds. If large areas of sunlit clouds are present, the light is largely reflected sunlight. If the sky is overcast, the north skylight is a result of a mixture of sunlight and blue skylight filtered through the clouds and is slightly bluish. If the sky is clear, the light varies from light blue to deep blue. [Illustration: FIREWORKS AND ILLUMINATED BATTLE-FLEET AT HUDSON-FULTON CELEBRATION] [Illustration: FIREWORKS EXHIBITION ON MAY DAY AT PANAMA-PACIFIC EXPOSITION] The daylight which enters buildings is often considerably altered in color by reflection from other buildings and from vegetation, and after it enters a room it is sometimes modified by reflection from colored surroundings. It may be commonly noted that the light reflected from green grass through a window to the upper part of a room is very much tinted with green and the light reflected from a yellow brick building is tinted yellow. Besides these alterations, sunlight varies in color from the yellow or red of dawn through white at noon to orange or red at sunset. Throughout the day the amount of light from the sky does not change nearly as much as the amount of sunlight, so there is a continual variation in the proportion of direct sunlight and skylight reaching the earth. This is further varied by the changing position of the sun. For example, at a north window in which the direct sunlight may not enter throughout the day, the amount of sunlight which enters by reflection from adjacent buildings and other objects may vary greatly. Thus it is seen that daylight not only varies in quantity but also in quality, and an artificial daylight, which is based upon an extensive analysis, has the advantage of being constant in quantity and quality as well as correct in quality. Modern artificial-daylight units which have been scientifically developed not only make mankind independent of daylight in the discrimination of colors but they are superior to daylight. Although there are many expert colorists who require an accurate artificial daylight, there are vast fields of lighting where a less accurate daylight quality is necessary. The average eyes are not sufficiently skilled for the finest discrimination of colors and therefore the Mazda "daylight" lamp supplies the less exacting requirements of color matching. It is a compromise between quality and efficiency of light and serves the purpose so well that millions of these lamps have found applications in stores, offices, and industries. In order to make an accurate artificial north skylight for color-work by means of colored glass, from 75 to 85 per cent. of the light from a tungsten lamp must be filtered out. This absorption in a broad sense increases the efficiency of the light, for the fraction that remains is now satisfactory, whereas the original light is virtually useless for accurate color-discrimination. About one third of the original light is absorbed by the bulb of the tungsten "daylight" lamp, with a resultant light which is an approximation to average daylight. Old illuminants such as that emitted by the candle and oil-lamp were used for centuries in interiors. All these illuminants were of a warm yellow color. Even the earlier modern illuminants were not very different in color, so it is not surprising that there is a deeply rooted desire for artificial light in the home and in similar interiors of a warm yellow color simulating that of old illuminants. The psychological effect of warmth and cheerfulness due to such illuminants or colors is well established. Artificial light in the home symbolizes independence of nature and protection from the elements and there is a firm desire to counteract the increasing whiteness of modern illuminants by means of shades of a warm tint. The white light is excellent for the kitchen, laundry, and bath-room, and for reading-lamps, but the warm yellow light is best suited for making cozy and cheerful the environment of the interiors in which mankind relaxes. An illuminant of this character can be obtained efficiently by using a properly tinted bulb on tungsten filament lamps. By absorbing about one fourth to one third of the light (depending upon the temperature of the filament) the color of the candle flame may be simulated by means of a tungsten filament lamp. Some persons are still using the carbon-filament lamp despite its low efficiency, because they desire to retain the warmth of tint of the older illuminants. However, light from a tungsten lamp may be filtered to obtain the same quality of light as is emitted by the carbon filament lamp by absorbing from one fifth to one fourth of the light. The luminous efficiency of the tungsten lamp equipped with such a tinted bulb is still about twice as great as that of the carbon-filament lamp. Thus the high efficiency of the modern illuminants is utilized to advantage even though their color is maintained the same as the old illuminants. All modern illuminants emit radiant energy, which does not affect the ordinary photographic plate. This superfluous visible energy merely contributes toward glare or a superabundance of light in photographic studios. A glass has been developed which transmits virtually all the rays that affect the ordinary photographic plate and greatly reduces the accompanying inactive rays. Such a glass is naturally blue in color, because it must transmit the blue, violet, and near ultra-violet rays. Its density has been so determined for use in bulbs for the high-efficiency tungsten lamps that the resultant light appears approximately the color of skylight without sacrificing an appreciable amount of the value of the radiant energy for ordinary photography. This glass, it is seen, transmits the so-called chemical rays and is useful in other activities where these rays alone are desired. It is used in light-therapy and in some other activities in which the chemical effects of these rays are utilized. In the photographic dark-room a deep red light is safe for all emulsions excepting the panchromatic, and lamps of this character are standard products. An orange light is safe for many printing papers. Panchromatic plates and films are usually developed in the dark where extreme safety is desired, but a very weak deep red light is not unsafe if used cautiously. However, many photographic emulsions of this character are not very sensitive to green rays, so a green light has been used for this purpose. A variety of colored lights are in demand for theatrical effects, displays, spectacular lighting, signaling, etc., and there are many superficial colorings available for this purpose. Few of these show any appreciable degree of permanency. Permanent superficial colorings have recently been developed, but these are secret processes unavailable for the market. For this reason colored glass is the only medium generally available where permanency is desired. For permanent lighting effects, signal glasses, colored caps, and sheets of colored glass may be used. Tints may be obtained by means of colored reflectors. Other colored media are dyes in lacquers and in varnishes, colored inks, colored textiles, and colored pigments. Inasmuch as colored glass enters into the development of permanent devices, it may be of interest to discuss briefly the effects of various metallic compounds which are used in glass. The exact color produced by these compounds, which are often oxides, varies slightly with the composition of the glass and method of manufacture, but this phase is only of technical interest. The coloring substances in glass may be divided into two groups. The first and largest group consists of those in which the coloring matter is in true solution; that is, the coloring is produced in the same manner as the coloring of water in which a chemical salt is dissolved. In the second group the coloring substances are present in a finely divided or colloidal state; that is, the coloring is due to the presence of particles in mechanical suspension. In general, the lighter elements do not tend to produce colored glasses, but the heavier elements in so far as they can be incorporated into glass tend to produce intense colors. Of course, there are exceptions to this general statement. The alkali metals, such as sodium, potassium, and lithium, do not color glass appreciably, but they have indirect effects upon the colors produced by manganese, nickel, selenium, and some other elements. Gold in sufficient amounts produces a red in glass and in low concentration a beautiful rose. It is present in the colloidal state. In the manufacture of "gold" red glass, the glass when first cooled shows no color, but on reheating the rich ruby color develops. The glass is then cooled slowly. The gold is left in a colloidal state. Copper when added to a glass produces two colors, blue-green and red. The blue-green color, which varies in different kinds of glasses, results when the copper is fully oxidized, and the red by preventing oxidation by the presence of a reducing agent. This red may be developed by reheating as in the case of making gold ruby glass. Selenium produces orange and red colors in glass. Silver when applied to the surface of glass produces a beautiful yellow color and it has been widely used in this manner. It has little coloring effect in glass, because it is so readily reduced, resulting in a metallic black. Uranium produces a canary yellow in soda and potash-lime glasses, which fluoresce, and these glasses may be used in the detection of ultra-violet rays. The color is topaz in lead glass. Both sulphur and carbon are used in the manufacture of pale yellow glasses. Antimony has a weak effect, but in the presence of much lead it is used for making opaque or translucent yellow glasses. Chromium produces a green color, which is reddish in lead glass, and yellowish in soda, and potash-lime glasses. Iron imparts a green or bluish green color to glass. It is usually present as an impurity in the ingredients of glass and its color is neutralized by adding some manganese, which produces a purple color complementary to the bluish green. This accounts for the manganese purple which develops from colorless glass exposed to ultra-violet rays. Iron is used in "bottle green" glass. Its color is greenish blue in potash-lime glass, bluish green in soda-lime glass, and yellowish green in lead glass. Cobalt is widely used in the production of blue glasses. It produces a violet-blue in potash-lime and soda-lime glasses and a blue in lead glasses. It appears blue, but it transmits deep red rays. For this reason when used in conjunction with a deep red glass, a filter for only the deepest red rays is obtained. Nickel produces an amethyst color in potash-lime glass, a reddish brown in soda-lime glass, and a purple in lead glass. Manganese is used largely as a "decolorizing" agent in counteracting the blue-green of iron. It produces an amethyst color in potash-lime glass and reddish violet in soda-lime and lead glasses. These are the principal coloring ingredients used in the manufacture of colored glass. The staining of glass is done under lower temperatures, so that a greater variety of chemical compounds may be used. The resulting colors of metals and metallic oxides dissolved in glass depend not only upon the nature of the metal used, but also partly upon the stage of oxidation, the composition of the glass and even upon the temperature of the fusion. In developing a glass filter the effects of the various coloring elements are determined spectrally and the various elements are varied in proper proportions until the glass of desired spectral transmission is obtained. It is seen that the coloring elements are limited and the combination of these is further limited by chemical considerations. In combining various colored glasses or various coloring elements in the same glass the "subtractive" method of color-mixture is utilized. For example, if a green glass is desired, yellowish green chromium glass may be used as a basis. By the addition of some blue-green due to copper, the yellow rays may be further subdued so that the resulting color is green. The primary colors for this method of color-mixture are the same as those of the painter in mixing pigments--namely, purple, yellow, and blue-green. Various colors may be obtained by superposing or intimately mixing the colors. The resulting transmission (reflection in the case of reflecting media such as pigments) are those colors commonly transmitted by all the components of a mixture. Thus, Purple and yellow = red Yellow and blue-green = green Blue-green and purple = blue The colors produced by adding lights are based not on the "subtractive" method but on the actual addition of colors. These primaries are red, green, and blue and it will be noted that they are the complementaries of the "subtractive" primaries. By the use of red, green, and blue lights in various proportions, all colors may be obtained in varying degrees of purity. The chief mixtures of two of the "additive" primaries produce the "subtractive" primaries. Thus, Red and blue = purple Red and green = yellow Green and blue = blue-green Although the coloring media which are permanent under the action of light, heat, and moisture are relatively few, by a knowledge of their spectral characteristics and other principles of color the expert is able to produce many permanent colors for lighting effects. The additive and subtractive methods are chiefly involved, but there is another method which is an "averaging" additive one. For example, if a warm tint of yellow is desired and only a dense yellow glass is available, the yellow glass may be cut into small pieces and arranged upon a colorless glass in checker-board fashion. Thus a great deal of uncolored light which is transmitted by the filter is slightly tinted by the yellow light passing through the pieces of yellow glass. If this light is properly mixed by a diffusing glass the effect is satisfactory. These are the principal means of obtaining colored light by means of filters and by mixing colored lights. By using these in conjunction with the array of light-sources available it is possible to meet most of the growing demands. Of course, the ideal solution is to make the colored light directly at the light-source, and doubtless future developments which now appear remote or even impossible will supply such colored illuminants. In the meantime, much is being accomplished with the means available. XXII SPECTACULAR LIGHTING Artificial light is a natural agency for producing spectacular effects. It is readily controlled and altered in color and the brightness which it lends to displays outdoors at night renders them extremely conspicuous against the darkness of the sky. It surpasses other decorative media by the extreme range of values which may be obtained. The decorator and painter are limited by a range of values from black to white pigments, which ordinarily represents an extreme contrast of about one to thirty. The brightnesses due to light may vary from darkness to those of the light-sources themselves. The decorator deals with secondary light--that is, light reflected by more or less diffusely reflecting objects. The lighting expert has at his command not only this secondary light but the primary light of the sources. Lighting effects everywhere attract attention and even the modern merchant testifies that adequate lighting in his store is of advertising value. In all the field of spectacular lighting the superiority of artificial light over natural light is demonstrated. Light is a universal medium with which to attract attention and to enthrall mankind. The civilizations of all ages have realized this natural power of light. It has played a part in the festivals and triumphal processions from time immemorial and is still the most important feature of many celebrations. In the early festivals fires, candles, and oil-lamps were used and fireworks were invented for the purpose. Even to-day the pyrotechnical displays against the dark depths of the night sky hold mankind spellbound. But these evanescent notes of light have been improved upon by more permanent displays on a huge scale. Thirty years before the first practical installation of gas-lighting an exhibition of "Philosophical Fireworks" produced by the combustion of inflammable gases was given in several cities of England. It is a long step from the array of flickering gas-flames with which the fronts of the buildings of the Soho works were illuminated a century ago to the wonderful lighting effects a century later at the Panama-Pacific Exposition. Some who saw that original display of gas-jets totaling a few hundred candle-power described it as an "occasion of extraordinary splendour." What would they have said of the modern spectacular lighting at the Exposition where Ryan used in a single effect forty-eight large search-lights aggregating 2,600,000,000 beam candle-power! No other comparison exemplifies more strikingly the progress of artificial lighting in the hundred years which have elapsed since it began to be developed. The nature of the light-sources in the first half of the nineteenth century did not encourage spectacular or display lighting. In fact, this phase of lighting chiefly developed along with electric lamps. Of course, occasionally some temporary effect was attempted as in the case of illuminating the dome of St. Paul's Cathedral in London in 1872, but continued operation of the display was not entertained. In the case of lighting this dome a large number of ship's lanterns were used, but the result was unsatisfactory. After this unsuccessful attempt at lighting St. Paul's, a suggestion was made of "flooding it with electric light projected from various quarters." Spectacular lighting outdoors really began in earnest in the dawn of the twentieth century. Although some of the first attempts at spectacular lighting outdoors were made with search-lights, spectacular lighting did not become generally popular until the appearance of incandescent filament lamps of reasonable efficiency and cost. The effects were obtained primarily by the use of small electric filament lamps draped in festoons or installed along the outlines and other principal lines of buildings and monuments. The effect was almost wholly that of light, for the glare from the visible lamps obscured the buildings or other objects. The method is still used because it is simple and the effects may be permanently installed without requiring any attention excepting to replace burned-out lamps. However, the method has limitations from an artistic point of view because the artistic effects of painting, sculpture, and architecture cannot be combined with it very effectively. For example, the details of a monument or of a building cannot be seen distinctly enough to be appreciated. The effect is merely that of outlines or lines and patterns of points of light and is usually glaring. The next step was to conceal these lamps behind the cornices or other projections or in nooks constructed the purpose. Light now began to mold and to paint the objects. The structures began to be visible; at least the important cornices and other details were no longer mere outlines. The introduction of the drawn-wire tungsten lamp is responsible for an innovation in spectacular lighting of this sort, for now it became possible to make concentrated light-sources so essential to projectors. Furthermore, these lighting units require very little attention after once being located. With the introduction of electric-filament lamps of this character small projectors came into use, and by means of concentrated beams of light whole buildings and monuments could be flooded with light from remote positions. The effects obtained by concealing lamps behind cornices had demonstrated that the lighting of the surfaces was the object to be realized in most cases, and when small projectors not requiring constant attention became available, a great impetus was given to flood-lighting. When France gave to this country the Bartholdi Statue of Liberty there was no thought of having this emblem visible at night excepting for the torch held the hand of Liberty. This torch was modified at the time of the erection of the statue to accommodate the lamps available, with the result that it was merely a lantern containing a number of electric lamps. At night it was a speck of light more feeble than many surrounding shore lights. The statue had been lighted during festivals with festoons and outlines of lamps, but in 1915, when the freedom of the generous donor of the statue appeared to be at stake, a movement was begun which culminated in a fund for flood-lighting Liberty. The broad foundation of the statue made the lighting comparatively easy by means of banks of incandescent filament search-lights. About 225 of these units were used with a total beam candle-power of about 20,000,000. The original idea of an imitation flame for the torch was restored by building this from pieces of yellow cathedral glass of three densities. About six hundred pieces of glass were used, the upper ones being generally of the lighter tints and the lower ones of the darker tints. A lighthouse lens was placed in this lantern so that an intense beam of light would radiate from it. The flood-lighted Statue of Liberty is now visible by night as well as by day and it has a double significance at night, for light also symbolizes independence. Just as the Statue of Liberty stands alone in the New York Harbor so does the Woolworth Building reign supreme on lower Manhattan. Liberty proclaims independence from the bondage of man and the Woolworth Tower stands majestically in defiance of the elements as a symbol of man's growing independence of nature. This building with its cream terra-cotta surface and intricate architectural details touched here and there with buff, blue, green, red, and gold, rises 792 feet or sixty stories above the street and typifies the American spirit of conceiving and of executing great undertakings. In it are blended art, utility, and majesty. Viewed by multitudes during the day, it is a valuable advertisement for the name which stands for a national institution. But by day it shares attention with its surroundings. If lighted at night it would stand virtually alone against the dark sky and the investment would not be wholly idle during the evening hours. Mr. H. H. Magdsick, who designed the lighting for Liberty, planned the lighting for the Woolworth Tower, which rises 407 feet or thirty-one stories above the main building. Five hundred and fifty projectors containing tungsten filament lamps were distributed about the base of the tower and among some of the architectural details. The main architectural features of the mansard roof extending from the fifty-third to the fifty-seventh floor, the observation balcony at the fifty-eighth and the lantern structures at the fifty-ninth and sixtieth floors are covered with gold-leaf. By proper placing of the projectors a glittering effect is obtained from these gold surfaces. The crowning features of the lighting effect are the lanterns in the crest of the spire. Twenty-four 1000-watt tungsten lamps were placed behind crystal diffusing glass, which transmits the light predominantly in a horizontal direction. Thus at long distances, from which the architectural details cannot be distinguished, the brilliant crowning light is visible. An automatic dimmer was devised so that the effect of a huge varying flame was obtained. At close range, owing to the nature of the glass panels, this portion is not much brighter than the remainder of the surfaces. When the artificial lighting is in operation the tower becomes a majestic spire of light and this magnificent Gothic structure projecting defiantly into the depths of darkness is in more than one sense a torch of modern civilization. Many prominent buildings and monuments have burst forth in a flood of light, and their beauty and symbolism have been appreciated at night by many persons who do not notice them by day. Not only are the beautiful structures of man lighted permanently but many temporary effects are devised. Artificial lighting effects have become a prominent part in outdoor festivals, pageants, and theatricals. Candles have been associated with Christmas trees ever since the latter came into use and naturally artificial light has been a feature in the community Christmas trees which have come into vogue in recent years. The Municipal Christmas Tree in Chicago in 1916 was ninety feet high and was lighted with projectors. Thousands of gems taken from the Tower of Jewels at the San Francisco Exposition added life and sparkle to that of the other decorations. [Illustration: The Capitol flooded with light Luna Park, Coney Island, studded with 60,000 incandescent filament lamps THE NEW FLOOD LIGHTING CONTRASTED WITH THE OLD OUTLINE LIGHTING] [Illustration: NIAGARA FALLS FLOODED WITH LIGHT] After the close of the recent war artificial light played a prominent part throughout the country in the joyful festivals. A jeweled arch erected in New York in honor of the returning soldiers rivaled some of the spectacles of the Panama-Pacific Exposition. The arch hung like a gigantic curtain of jewels between two obelisks, which rose to a height of eighty feet and were surmounted by jeweled forms in the shape of sunbursts. Approximately thirty thousand jewels glittered in the beams of batteries of arc-projectors. Many of the signs and devices which played a part in the "Welcome Home" movement were of striking nature and of a character to indicate permanency. The equipment of a large building consisted of more than five thousand 10-watt lamps, the entire building being outlined with stars consisting of eleven lamps each. The "Brighten Up" campaign spread throughout the country. The lighting and installation of signs and special patriotic displays, the flooding of streets and shop-windows with light without stint, produced an inspiring and uplifting effect which did much to restore cheerfulness and optimism. A glowing example was set in Washington, where the flood-lighting of the Capitol, discontinued shortly after our entrance into the war, was resumed. In Chicago a "Victory Way" was established, with street-lighting posts on both sides of the street equipped with red, white, and blue globes surmounted by a golden goddess of Victory. One hundred and seventy-five projectors were installed along the way on the roofs and in the windows of office buildings. A brilliant, scintillating "Altar of Victory" was erected at the center of the Way. It was composed of two enormous candelabra erected one on each side of a platform ninety feet high. These were studded with jewels and supported a curtain of jewels suspended from the altar. In the center of the curtain was a huge jeweled eagle bearing the Allied flags. This was illuminated by arc-projectors which delivered 200,000,000 beam candle-power. In addition to these there were many smaller projectors. In the top of each candelabra six large red-and-orange lamps were installed in reflectors. These illuminated live steam which issued from the top. Surmounting the whole was a huge luminous fan formed by beams from large arc search-lights. These are only a few of the many lighting effects which welcomed the returning soldiers, but they illustrate how much modern civilization depends upon artificial light for expressing its feelings and emotions. Throughout all these festivals light silently symbolized happiness, freedom, and advancement. Projectors were used on a large scale in several cases before the advent of the concentrated filament lamp. W. D'A. Ryan, the leader in spectacular lighting, lighted the Niagara Falls in 1907 with batteries of arc-projectors aggregating 1,115,000,000-beam candle-power. In 1908 he used thirty arc-projectors to flood the Singer Tower in New York with light and projected light to the flag on top by means of a search-light thirty inches in diameter. Many flags waved throughout the war in the beams of search-lights, symbolizing a patriotism fully aroused. The search-light beam as it bores through the atmosphere at night is usually faintly bright, owing to the small amount of fog, dust, and smoke in the air. By providing more "substance" in the atmosphere, the beams are made to appear brighter. Following this reasoning, Ryan developed his scintillator consisting of a battery of search-light beams projected upward through clouds of steam which provided an artificial fog. This was first displayed at the Hudson-Fulton celebration with a battery of arc search-lights totaling 1,000,000,000-candle-power. All these effects despite their magnitude were dwarfed by those at the Panama-Pacific Exposition, and inasmuch as this up to the present time represents the crowning achievement in spectacular lighting, some of the details worked out by Ryan may be of interest. In general, the lighting effects departed from the bizarre outline lighting in which glaring light-sources studded the structures. The radiant grandeur and beauty of flood-lighting from concealed light-sources was the key-note of the lighting. In this manner wonderful effects were obtained, which not only appealed to the eye and to the artistic sensibility but which were free from glare. By means of flood-lighting and relief-lighting from concealed light-sources the third dimension or depth was obtained and the architectural details and colorings were preserved. A great many different kinds of devices and lamps were used to make the night effects superior in grandeur to those of daytime. The Zone or amusement section was lighted with bare lamps in the older manner and the glaring bizarre effects contrasted the spectacular lighting of the past with the illumination of the future. In another section the visitor was greeted with a gorgeous display of carnival spirit. Beautifully colored heraldic shields on which were written the early history of the Pacific coast were illuminated by groups of luminous arc-lamps on standards varying from twenty-five to fifty-five feet in height. The Tower of Jewels with more than a hundred thousand dangling gems was flood-lighted, and the myriads of minute reflected images of light-sources glittering against the dark sky produced an effect surpassing the dreams of imagination. Shadows and high-lights of striking contrasts or of elusive colors greeted the visitor on every hand. Individual isolated effects of light were to be found here and there. Fire hissed from the mouths of serpents and cast the spell of mobile light over the composite Spanish-Gothic-Oriental setting. A colored beam of a search-light played here and there. Mysterious vapors rising from caldrons were in reality illuminated steam. Symbolic fountain groups did not escape the magic touch of the lighting wizard. In the Court of the Universe great areas were illuminated by two fountains rising about a hundred feet above the sunken gardens. One of these symbolized the setting sun, the other the rising sun. The shaft and ball at the crest of each fountain were glazed with heavy opal glass imitating travertine marble and in these were installed incandescent lamps of a total candle-power of 500,000. The balustrade seventy feet above the sunken gardens was surmounted by nearly two hundred incandescent filament search-lights. Light was everywhere, either varying in color into a harmonious scene or changing in light and shadow to mold the architecture and sculpture. The enormous glass dome of the Palace of Horticulture was converted into an astronomical sphere by projecting images upon it in such a manner that spots of light revolved; rings and comets which appeared at the horizon passed on their way through the heavens, changing in color and disappearing again at the horizon. All these effects and many more were mirrored in the waters of the lagoons and the whole was a Wonderland indeed. The scintillator consisted of 48 arc search-lights three feet in diameter totaling 2,600,000,000 beam candle-power. The lighting units were equipped with colored screens and the beams which radiated upward were supplied with an artificial fog by means of steam generated by a modern express locomotive. The latter was so arranged that the wheels could be driven at a speed of sixty miles per hour under brake, thereby emitting great volumes of steam and smoke, which when illuminated with various colors produced a magnificent spectacle. Over three hundred scintillator effects were worked out and this feature of fireless fireworks was widely varied. The aurora borealis and other effects created by this battery of search-lights extended for many miles. The many effects regularly available were augmented on special occasions and it is safe to state that this apparatus built upon a huge scale provided a flexibility of fireless fireworks never attained even with small-scale devices. The lighting of the exposition can barely be touched upon in a few paragraphs and it would be difficult to describe in words even if space were unlimited. It represented the power of light to beautify and to awe. It showed the feebleness of the decorator's media in comparison with light pulsating with life. It consisted of a great variety of direct, masked, concealed, and projected effects, but these were blended harmoniously with one another and with the decorative and architectural details of the structures. It was a crowning achievement of a century of public lighting which began with Murdock's initial display of a hundred flickering gas-jets. It demonstrated the powers of science in the production of light and of genius and imagination in the utilization of light. It was a silent but pulsating display of grandeur dwarfing into insignificance the aurora borealis in its most resplendent moments. XXIII THE EXPRESSIVENESS OF LIGHT From an esthetic or, more broadly, a psychological point of view no medium rivals light in expressiveness. Not only is light allied with man's most important sense but throughout long ages of associations and uses mankind has bestowed upon it many attributes. In fact, it is possible that light, color, and darkness possess certain fundamentally innate powers; at least, they have acquired expressive and impressive powers through the many associations in mythology, religion, nature, and common usage. Besides these attributes, light possesses a great advantage over the media of decoration in obtaining brightness and color effects. For example, the landscape artist cannot reproduce the range of values or brightnesses in most of nature's scenes, for if black is used to represent a deep shadow, white is not bright enough to represent the value of the sky. In fact, the range of brightnesses represented by the deep shadow and the sky extends far beyond the range represented by black and white pigments. The extreme contrast ordinarily available by means of artist's colors is about thirty to one, but the sky is a thousand times brighter than a shadow, a sunlit cloud is thousands of times brighter than the deep shadows of woods, and the sun is millions of times brighter than the shadows in a landscape. The range of brightnesses obtainable by means of light extends from darkness or black throughout the range represented by pigments under equal illumination and beyond these through the enormous range obtainable by unequal illumination of surfaces to the brightnesses of the light-sources themselves. In the matter of purity of colors, light surpasses reflecting media, for it is easy to obtain approximately pure hues by means of light and to obtain pure spectral hues by resorting to the spectrum of light. It is impossible to obtain pure hues by means of pigments or of other reflecting media. These advantages of light are very evident on turning to spectacular lighting effects, and even the lighting of interiors illustrates a potentiality in light superior to other media. For example, in a modern interior in which concealed lighting produces brilliantly illuminated areas above a cornice and dark shadows on the under side, the range in values is often much greater than that represented by black and white, and still there remains the possibility of employing the light-sources themselves in extending the scale of brightness. Superposing color upon the whole it is obvious that the combination of "primary" light with reflected light possesses much greater potentiality than the latter alone. This potentiality of light is best realized if lighting is regarded as "painting with light" in a manner analogous to the decorator's painting with pigments, etc. The expressive possibilities of lighting find extensive applications in relation to painting, sculpture, and architecture. A painting is an expression of light and the sculptor's product finally depends upon lighting for its effectiveness. Lighting is the master painter and sculptor. It may affect the values of a painting to some extent and it is a great influence upon the colors. It molds the model from which the sculptor works and it molds the completed work. The direction, distribution, and quality of light influence the appearance of all objects and groups of them. Aside from the modeling of ornament, the light and shade effects of relatively large areas in an interior such as walls and ceiling, the contrasts in the brightnesses of alcoves with that of the main interior, and the shadows under cornices, beams, and arches are expressions of light. The decorator is able to produce a certain mood in a given interior by varying the distribution of values and the choice of colors and the lighting artist is able to do likewise, but the latter is even able to alter the mood produced by the decorator. For example, a large interior flooded with light from concealed sources has the airiness and extensiveness of outdoors. If lighted solely by means of sources concealed in an upper cornice, the ceiling may be bright and the walls may be relatively dark by contrast. Such a lighting effect may produce a feeling of being hemmed in by the walls without a roof. If the room is lighted by means of chandeliers hung low and equipped with shades in such a manner that the lower portions of the walls may be light while the upper portions of the interior may be ill defined, the feeling produced may be that of being hemmed in by crowding darkness. Thus lighting is productive of moods and illusions ranging from the mystery of crowding darkness to the extensiveness of outdoors. Future lighting of interiors doubtless will provide an adequacy of lighting effects which will meet the respective requirements of various occasions. A decorative scheme in which light and medium grays are employed produces an interior which is very sensitive to lighting effects. To these light-and-shade effects colored light may add its charming effectiveness. Not only are colored lighting effects able to add much to the beauty of the setting but they possess certain other powers. Blue tints produce a "cold" effect and the yellow and orange tints a "warm" effect. For example, a room will appear cooler in the summer when illuminated by means of bluish light and a practical application of this effect is in the theater which must attract audiences in the summer. How tinted illuminants fit the spirit of an occasion or the mood of a room may be fully appreciated only through experiments, but these are so effective that the future of lighting will witness the application of the idea of "painting with light" to its fullest extent. Color is demanded in other fields, and, considering its effectiveness and superiority in lighting, it will certainly be demanded in lighting when its potentiality becomes appreciated and readily utilized. The expressiveness of light is always evident in a landscape. On a sunny day the mood of a scene varies throughout the day and it grows more enticing and agreeable as the shadows lengthen toward evening. The artist in painting a desert scene employs short harsh shadows if he desires to suggest the excessive heat. These shadows suggest the relentless noonday sun. The overcast sky is universally depressing and it has been found that on a sunny day most persons experience a slight depression when a cloud obscures the sun. Nature's lighting varies from moment to moment, from day to day, and from season to season. It presents the extremes of variation in distributions of light from overcast to sunny days and in the latter cases the shadows are continually shifting with the sun's altitude. They are harshest at noon and gradually fade as they lengthen, until at sunset they disappear. The colors of sunlit surfaces and of shadows vary from sunrise to sunset. These are the fundamental variations in the lighting, but in the various scenes the lighting effects are further modified by clouds and by local conditions or environment. The vast outdoors provides a fruitful field for the study of the expressiveness of light. Having become convinced of this power of light, the lighting expert may turn to artificial light, which is so easily controlled in direction, distribution, and color, and draw upon its potentiality. Not only is it easy to provide a lighting suitable to the mood or to the function of an interior but it is possible to obtain some variety in effect so that the lighting may always suit the occasion. A study of nature's lighting reveals one great principle, namely, variety. Mankind demands variety in most of his activities. Work is varied and alternated with recreation. Meals are not always the same. Clothing, decorations, and furnishings are relieved of monotony. One of the most potent features of artificial light is the ease with which variety may be obtained. In obtaining relief from the monotony of decorations and furnishings, considerable expense and inconvenience are inevitably encountered. With an adequate supply of outlets, circuits, and controls a wide variety of lighting effects may be obtained with perhaps an insignificant increase in the initial investment. Variety is the spice of lighting as well as of life. These various principles of lighting are readily exemplified in the lighting of the home, which is discussed in another chapter. The church is even a better example of the expressive possibilities of lighting. The architectural features are generally of a certain period and first of all it is essential to harmonize the lighting effect with that of the architectural and decorative scheme. Obviously, the dark-stained ceiling of a certain type of church would not be flooded with light. The fact that it is made dark by staining precludes such a procedure in lighting. The characteristics of creeds are distinctly different and these are to some extent exemplified by the lines of the architecture of their churches. In the same way the lighting effect may be harmonized with the creed and the spirit of the interior. The lighting may always be dignified, impressive, and congruous. Few churches are properly lighted with a high intensity of illumination; moderate lighting is more appropriate, for it is conducive to the spirit of worship. In some creeds a dominant note is extreme penitence and severity. The architecture may possess harsh outlines, and this severity or extreme solemnity may be expressed in lighting by harsher contrasts, although this does not mean that the lighting must be glaring. On the other hand, in a certain modern creed the dominant note appears to be cheerfulness. The spacious interiors of the churches of this creed are lacking in severe lines and the walls and ceilings are highly reflecting. Adequate illumination by means of diffused light without the production of severe contrasts expresses the creed, modernity, and enlightenment. On the altar of certain churches the expressiveness of light is utilized in the ceremonial uses which vary with the creed. Even the symbolism of color may be appropriately woven into the lighting of the church. The expressiveness of light and color originated through the contact of primitive man with nature. Sunlight meant warmth and a bountiful vegetation, but darkness restricted his activities and harbored manifold dangers. Many associations thus originated and they were extended through ignorance and superstition. Yellow is naturally emblematical of the sun and it became the symbol of warmth. Brown as the predominant color of the autumn foliage became tinctured with sadness because the decay of the vegetation presaged the death of the year and the cold dreary months of winter. The first signs of green vegetation in the spring were welcomed as an end of winter and a beginning of another bountiful summer; hence green symbolized youth and hope. It became associated with the springtime of life and thus signified inexperience, but as the color of vegetation it also meant life itself and became a symbol of immortality. Blue acquired certain divine attributes because, as the color of the sky, it was associated with the abode of the gods or heaven. Also a blue sky is the acme of serenity and this color acquired certain appropriate attributes. Associations of this character became woven into mythology and thus became firmly established. Poets have felt these influences of light and color in nature and have given expression to them in words. They also have entwined much of the mythology of past civilizations and these repetitions have helped to establish the expressiveness of light and color. Early ecclesiasts employed these symbolisms in religious ceremonies and dictated the garbs of saints and other religious personages in the paintings which decorated their edifices. Thus there were many influences at work during the early centuries when intellects were particularly susceptible through superstition and lack of knowledge. The result has been an extensive symbolism of light, color, and darkness. At the present time it is difficult to separate the innate appeal of light, color, and darkness from those attributes which have been acquired through associations. Possibly light and color have no innate powers but merely appear to have because the acquired attributes have been so thoroughly established through usage and common consent. Space does not permit a discussion of this point, but the chief aim is consummated if the existence of an expressiveness and impressiveness of light is established. There are many other symbolisms of color and light which have arisen in various ways but it is far beyond the scope of this book to discuss them. Psychological investigations reveal many interesting facts pertaining to the influence of light and color upon mankind. When choosing color for color's sake alone, that is, divorced from any associations of usage, mankind prefers the pure colors to the tints and shades. It is interesting to note that this is in accord with the preference exhibited by uncivilized beings in their use of colors for decorating themselves and their surroundings. Civilized mankind chooses tints and shades predominantly to live with, that is, for the decoration of his surroundings. However, civilized man and the savage appear to have the same fundamental preference for pure colors and apparently culture and refinement are responsible for their difference in choice of colors to live with. This is an interesting discovery and it has its applications in lighting, especially in spectacular and stage-lighting. It appears to be further established that when civilized man chooses color for color's sake alone he not only prefers the pure colors but among these he prefers those near the ends of the spectrum, such as red and blue. Red is favored by women, with blue a close second, but the reverse is true for men. It is also thoroughly established that red, orange, and yellow exert an exciting influence; yellow-green, green, and blue-green, a tranquilizing influence, and blue and violet a subduing influence upon mankind. All these results were obtained with colors divorced from surroundings and actual usage. In the use of light and color the laws of harmony and esthetics must be obeyed, but the sensibility of the lighting artist is a satisfactory guide. Harmonies are of many varieties, but they may be generally grouped into two classes, those of analogy and those of contrast. The former includes colors closely associated in hue and the latter includes complementary colors. No rules in simplified form can be presented for the production of harmonies in light and color. These simplifications are made only by those who have not looked deeply enough into the subject through observation and experiment to see its complexity. The expressiveness of light finds applications throughout the vast field of lighting, but the stage offers great opportunities which have been barely drawn upon. When one has awakened to the vast possibilities of light, shade, and color as a means of expression it is difficult to suppress a critical attitude toward the crudity of lighting effects on the present stage, the lack of knowledge pertaining to the latent possibilities of light, and the superficial use of this potential medium. The crude realism and the almost total absence of deep insight into the attributes of light and color are the chief defects of stage-lighting to-day. One turns hopefully toward the gallant though small band of stage artists who are striving to realize a harmony of lighting, setting, and drama in the so-called modern theater. Unappreciated by a public which flocks to the melodramatic movie, whose scenarios produced upon the legitimate stage would be jeered by the same public, the modern stage artist is striving to utilize the potentiality of light. But even among these there are impostors who have never achieved anything worth while and have not the perseverance to learn to extract some of the power of light and to apply it effectively. Lighting suffers in the hands of the artist owing to the absence of scientific knowledge and it is misused by the engineer who does not possess an esthetic sensibility. Science and art must be linked in lighting. The worthy efforts of stage artists in some of the modern theaters lack the support of the producers, who cater to the taste of the public which pays the admission fees. Apparently the modern theater must first pass through a period in which financial support must be obtained from those who are able to give it, just as the symphony orchestra has been supported for the sake of art. Certainly the time is at hand for philanthropy to come to the aid of worthy and capable stage artists who hope to rescue theatrical production from the mire of commercialism. Those who have not viewed stage-lighting from behind the scenes would often be surprised at the crudity of the equipment, and especially at the superficial intellects which are responsible for some of the realistic effects obtained. But these are the result usually of experiment, not of directed knowledge. Furthermore, little thought is given to the emotional value of light, shade, and color. The flood of light and the spot of light are varied with gaudy color-effects, but how seldom is it possible to distinguish a deep relation between the lighting and the dramatic incidents! [Illustration: Soldiers' and Sailors' Monument Jeweled portal welcoming returned soldiers ARTIFICIAL LIGHT HONORING THOSE WHO FELL AND THOSE WHO RETURNED] [Illustration] [Illustration: THE EXPRESSIVENESS OF LIGHT IN CHURCHES] In much of the foregoing discussion the present predominating theatrical productions are not considered, for the lighting effects are good enough for them. Many ingenious tricks and devices are resorted to in these productions, and as a whole lighting is serving effectively enough. But in considering the expressiveness of light the deeper play is the medium necessary for utilizing the potentiality of light. These are rare and unfortunately the stage artist appreciative of the significations and emotional value of light and color is still rarer. The equipment of the present stage consists of footlights, side-lights, border-lights, flood-lights, spot-lights, and much special apparatus. One of the severest criticisms of stage-lighting from an artistic point of view may be directed against the use of footlights for obtaining the dominant light. This is directed upward and the effect is an unnatural and even a grotesque modeling of the actors' features. The shadows produced are incongruous, for they are opposed to the other real and painted effects of light and shade. The only excuse for such lighting is that it is easily done and that proper lighting is difficult to obtain, owing to the fact that it involves a change in construction. By no means should the footlights be abandoned, for they would still be invaluable in obtaining diffused light even when the dominant light is directed from above the horizontal. In the present stage-lighting, in which the footlights generally predominate, the expressiveness of light is not satisfactory. Perhaps they are a necessary compromise, but inasmuch as their effect is unnatural they should not be accepted until it is thoroughly proved that ingenuity cannot eliminate the present defects. The stage as a whole is a mobile picture in light, shade, and color with the addition of words and music. Excepting the latter, it is an expression of light worthy of the same care and consideration that the painting, which is also an expression of light, receives from the artist. The scenery and costumes should be considered in terms of the lighting effects because they are affected by changes in the color of the light. In fact, the author showed a number of years ago that by carefully relating the colors of the light with the colors used in painting the scenery, a complete change of scene can be obtained by merely changing the color of the light. Rather wonderful dissolving effects can be produced in this manner without shifting scenery. For example, a warm summer scene with trees in full foliage under a yellow light may be changed under a bluish light to a winter scene with ground covered with snow and trees barren of leaves. But before such accomplishments can be realized upon the stage, scientific knowledge must be available behind the scenes. The art museum affords a multitude of opportunities for utilizing the expressiveness of light. This is more generally true of sculptured objects than of paintings because the latter may be treated as a whole. The artist almost invariably paints a picture by daylight and unless it is illuminated by daylight it is altered in appearance, that is, it becomes another picture. The great difference in the appearance of a painting under daylight and ordinary artificial light is quite startling, when demonstrated by means of apparatus in which the two effects may be rapidly alternated. Art museums are supposed to exhibit the works of artists and, therefore, no changes in these works should be tolerated if they can be avoided. The modern artificial-daylight lamps make it possible to illuminate galleries with light at night which approximates daylight. A further advantage of artificial light is that it may be easily controlled and a more satisfactory lighting may be obtained than with natural light. Considering the cost of daylight in museums and its disadvantages it appears possible that artificial daylight with its advantages may replace it eventually in the large galleries. If the works of artists are really prized for their appearance, the lighting of them is very important. Sculpture is modeled by light and although it is impossible to ascertain the lighting under which the sculptor viewed his completed work with pride and satisfaction, it is possible to give the best consideration to its lighting in its final place of exhibition. The appearance of a sculpture depends upon the dominant direction of the light, the solid-angle subtended by the light-source (skylight, area of sky, etc.) and the amount of scattered light. The direction of dominant light determines the general direction of the shadows; the solid-angle of the light-source affects the character of the edges of the shadows; and the scattered light accounts for the brightness of the shadows. It should be obvious that variations of these factors affect the appearance or expression of three-dimensional objects. Therefore the position of a sculptured object with respect to the window or other skylight and the amount of light reflected from the surroundings are important. Visits to art museums with these factors in mind reveal a gross neglect in the lighting of objects of art which are supposed to appeal by virtue of their appearances, for they can arouse the emotions only through the doorway of vision. A century ago mankind gave no thought to utilizing the expressive and impressive powers of light except in religious ceremonies. It was not practicable to utilize light from the feeble flames of those days in the elaborate manner necessary to draw upon these powers. Man was concerned with the more pressing needs. He wanted enough light to make the winter evenings endurable and the streets reasonably safe. The artists of those days saw the wonderful expressions of light exhibited by Nature, but they dared not dream of rivaling these with artificial light. To-day Nature surpasses man in the production of lighting effects only in magnitude. Man surpasses her artistically. In fact, the artist becomes a master only when he can improve upon her settings; when he is able by rare judgment in choosing and in eliminating and by skill and ingenuity to substitute a complete harmony for her incomplete and unsatisfactory reality. But everywhere Nature is the great teacher, for her world is full of an everchanging infinitude of expressions of light. Mankind needs only to study these with an attuned sensibility to be able eventually to play the music of light for those who are blessed with an esthetic sense. XXIV LIGHTING THE HOME In the home artificial light exerts its influence upon every one. Without artificial lighting the family circle may not have become the important civilizing influence that it is to-day. Certainly civilized man now shudders at the thought of spending his evenings in the light of the fire upon the hearth or of a burning splinter. The importance of artificial light is emphatically impressed upon the householder when he is forced temporarily to depend upon the primitive candle through the failure of the modern system of lighting. He flees from his home to that of his more fortunate neighbor, or he retires in his helplessness to awaken in the morning with a blessing for daylight. He cannot conceive of happiness and recreation in the homes of a century or two ago, when a few candles or an oil-lamp or two were the sole sources of light. But when the electric or gas service is again restored he relapses shortly into his former placid indifference toward the wonderfully efficient and adequate artificial light of the present age. Until recently artificial light was costly and the householder in common with other users of light did not concern himself with the question of adequate and artistic lighting. His chief aim was to utilize as little as possible, for cost was always foremost in his mind. The development of the science of light-production has been so rapid during the past generation that adequate, efficient, and cheap artificial light finds mankind unconsciously viewing lighting with the same attitude as he displays toward his food and fuel bills. Another consequence of this rapid development is that mankind does not know how to extract the joy from modern artificial light. This is readily demonstrated by analyzing the lighting of middle-class homes. The cost of light has been discussed in another chapter and it has been shown that it has decreased enormously in a century. It is now the most potential agency in the home when viewed from the standpoint of cost. The average householder pays less than twenty dollars per year for ever-ready light throughout his home. For about five cents per day the average family enjoys all the blessings of modern lighting, which is sufficient proof that cost is an insignificant item. In order to simplify the discussion of lighting the home the terminology of electric-lighting will be used. The principles expounded apply as well to gas as to electricity, and owing to the ingenuity of the gas-lighting experts, the possibilities of gas-lighting are extensive despite its handicaps. There are some places in the home, such as the kitchen and basement, where lighting is purely utilitarian in the narrow sense, but in most of the rooms the esthetic or, more broadly, the psychological aspects of lighting should dominate. Pure utility is always a by-product of artistic lighting and furthermore, the lighting effects will be without glare when they satisfy all the demands of esthetics. In dealing with lighting in the home the householder should concentrate his attention upon lighting effects. Unfortunately, he is not taught to do so, for everywhere he turns for help he finds the discussion directed toward fixtures and lamps instead of toward lighting effects. However, these are merely links in the chain from the meter to the eye. Lamps are of interest from the standpoint of quantity and quality of light, and fixtures are of importance chiefly as distributers of light. These details are merely means to an end and the end is the lighting effect. Of course, the fixtures are more important as objects than the wires because they are visible and should harmonize with the general decorative and architectural scheme. The home is the theater of life full of various moods and occasions; hence the lighting of a home should be flexible. A degree of variety should be possible. Controls, wiring, outlets, and fixtures should conspire to provide this variety. At the present time the average householder does not give much attention to lighting until he purchases fixtures. It is probable that he thought of it when he laid out or approved the wiring, but usually he does not consider it seriously until he visits the fixture-dealer to purchase fixtures. And then unfortunately the fixture-dealer does not light his home; he does not sell the householder lighting-effects designed to meet the requirements of the particular home; he sells merely fixtures. Unfortunately there are few fixtures available which have definite aims in lighting as demanded by the home. Of the great variety of fixtures available there are many artistic objects, but it is obvious that little attention is given to their design from the standpoint of lighting. That the fixture-dealer usually thinks of fixtures as objects and gives little or no thought to lighting effects is apparent from his conversation and from his display. He exhibits fixtures usually en masse and seldom attempts to illustrate the lighting effects produced in the room. The foregoing criticisms are presented to emphasize the fact that throughout the field of lighting the great possibilities which have been opened by modern light-sources are not fully appreciated. The point at which to begin to design the lighting for a home is the wiring. Unfortunately this is too often done by a contractor who has given no special thought to the possibilities of lighting and to the requirements in wiring and switches necessary in order to realize them. At this point the householder should attempt to form an opinion as to the relative values. Is artificial lighting important enough to warrant an expenditure of two per cent. of the total investment in the home and its furnishings? The answer will depend upon the extent to which artificial light is appreciated. It appears that four or five per cent. is not too much if it is admitted that the artificial lighting system ranks next to the heating plant in importance and that these two are the most important features of an interior of a residence. A switch or a baseboard outlet costs an insignificant sum but either may pay for itself many times in the course of a few years through its utility or convenience. It appears best to take up this subject room by room because the requirements vary considerably, but in order to be specific in the discussions, a middle-class home will be chosen. The more important rooms will be treated first and various simple details will be touched upon because, after all, the proper lighting of a home is realized by attention to small details. The living-room is the scene of many functions. It serves at times for the quiet gathering of the family, each member devoted to reading. At another time it may contain a happy company engaged at cards or in conversation. The lighting requirements vary from a spot or two of light to a flood of light. Excepting in the small living-rooms there does not appear to be a single good reason for a ceiling fixture. It is nearly always in the field of vision when occupants are engaged in conversation, and for reading purposes the portable lamp of satisfactory design has no rival. Wall brackets cannot supply general lighting without being too bright for comfort. If they are heavily shaded they may still emit plenty of light upward, but the adjacent spots on the walls or ceiling will generally be too bright. Wall brackets may be beautiful ornaments and decorative spots of light and have a right to exist as such, but they cannot be safely depended upon for adequate general lighting on those occasions which demand such lighting. As a general principle, it is well to visualize the furniture in the room when looking at the architect's drawings and it is advantageous even to cut out pieces of paper representing the furniture in scale. By placing these on the drawings the furnished room is readily visualized and the locations of baseboard outlets become evident. It appears that the best method of lighting a living-room is by means of decorative portable lamps. Such lamps are really lighting-furniture, for they aid in decorating and in furnishing the room at all times. A number of these lamps in the living-room insures great flexibility in the lighting, and the light may be kept localized if desired so that the room is restful. A room whose ceiling and walls are brilliantly illuminated is not so comfortable for long periods as one in which these areas are dimly lighted. Furthermore, the latter is more conducive to reading and to other efforts at concentration. The furniture may be readily shifted as desired and the portable lamps may be rearranged. Such lighting serves all the purposes of the living-room excepting those requiring a flood of light, but it is easy to conceal elaborate lighting mechanisms underneath the shades of portable lamps. Several types of portable lamps are available which supply an indirect component as well as direct light. The former illuminates the ceiling with a flood of light without any discomforting glare. Such a lighting-unit is one of the most satisfactory for the home, for two distinct effects and a combination of these introduce a desirable element of variety into the lighting. Not less than four and preferably six baseboard outlets should be provided in a living-room of moderate size. One outlet on the mantel is also to be desired for connecting decorative candlesticks, and brackets above the fireplace are of ornamental value. Although the absence of ceiling fixtures improves the appearance of the room, wiring may be provided for ceiling outlets in new houses as a matter of insurance against the possible needs of the future. When ceiling fixtures are not used, switches may be provided for the mantel brackets or certain baseboard outlets in order that light may be had upon entering the room. The merits of a portable lamp may be ascertained before purchasing by actual demonstration. Some of them are not satisfactory for reading-lamps, owing to the shape of the shade or to the position of the lamps. The utility of a table lamp may be determined by placing it upon a table and noting the spread of light while seated in a chair beside it. A floor lamp may also be tested very easily. A miniature floor lamp about four feet in height with an appropriate shade provides an excellent lamp for reading purposes because it may be placed by the side of a chair or moved about independent of other furniture. A tall floor lamp often serves for lighting the piano, but small piano lamps may be found which are decorative as well as serviceable in illuminating the music without glare. The dining-room presents an entirely different problem for the setting is very definite. The dining-table is the most important area in the room and it should be the most brilliantly illuminated area in the room. A demonstration of this point is thoroughly convincing. The decorator who designs wall brackets for the dining-room is interested in beautiful objects of art and not in a proper lighting effect. The fixture-dealer, having fixtures to sell and not recognizing that he could fill a crying need as a lighting specialist, is as likely to sell a semi-indirect or an indirect lighting fixture as he is to provide a properly balanced lighting effect with the table brightly illuminated. The indirect and semi-indirect units illuminate the ceiling predominantly with the result that this bright area distracts attention from the table. A brightly illuminated table holds the attention of the diners. Light attracts and a semi-darkness over the remainder of the room crowds in with a result that is far more satisfactory than that of a dining-room flooded with light. The old-fashioned dome which hung over the dining-table has served well, for it illuminated the table and left the remainder of the room dimly lighted. But its wide aperture made it necessary to suspend it rather low in order that the lamps within should not be visible. It is an obtrusive fixture and despite its excellent lighting effect, it went out of style. But satisfactory lighting principles never become antiquated, and as taste in fixtures changes the principles may be retained in new fixtures. Modern domes are available which are excellent for the dining-room if the lamps are well concealed. The so-called showers are satisfactory if the shades are dense and of such shape as to conceal the lamps from the eyes. Various modifications readily suggest themselves to the alert fixture-designer. Even the housewife can do much with silk shades when the principle of lighting the dining-table is understood. The so-called candelabra have been sold extensively for dining-rooms and they are fairly satisfactory if equipped with shades which reflect much of the light downward. Semi-indirect and indirect fixtures have many applications in lighting, but they do not provide the proper effect for a dining-room. It is easy to make a special fixture which will send a component of light downward to the table and will permit a small amount of diffused light to the ceiling and walls. If a daylight lamp is used for the direct component, the table will appear very beautiful. Under this light the linen and china are white, flowers and decorations on the china appear in their full colors, the silver is attractive, and the various color-harmonies such as butter, paprika, and baked potato are enticing. This is an excellent place for a daylight lamp if diffused light illuminating the remainder of the room and the faces of the diners is of a warm tone obtained by warm yellow lamps or by filtering these components of the light through orange shades. The ceiling fixture should be provided with two circuits and switches. In some cases it is easy to provide a dangling plug for connecting such electric equipment as a toaster, percolator, or candlesticks. Two candlesticks are effective on the buffet, but usually the smallest normal-voltage lamps available give too much light. Miniature lamps may be used with a small transformer, or two regular lamps may be connected in series. At least two baseboard outlets are convenient. The foregoing deals with the more or less essential lighting of a dining-room, but there are various practicable additional lighting effects which add much charm to certain occasions. Colored light of low intensity obtained from a cove or from "flower-boxes" fastened upon the wall is very pleasing. If a cove is provided around the room, two circuits containing orange and blue lamps respectively will supply two colors widely differing in effect. By mixing the two a beautiful rose tint may be obtained. This equipment has been installed with much satisfaction. A simpler method of obtaining a similar effect is to use imitation flower-boxes plugged into wall outlets. Artificial foliage adds to the charm of these boxes. The colored light is merely to add another effect on special occasions and its intensity should never be high. In the dining-room such unusual effects are not out of place and they need not be garish. The sun-room partakes of the characteristics of the living-room to some extent, but, it being smaller, a semi-indirect fixture may be satisfactory for general illumination. However, a portable lamp which supplies an indirect component of light besides the direct light serves admirably for reading as well as for flooding the room with light when necessary. Two or three baseboard outlets are desirable for attaching decorative or even purely utilitarian lamps. The sun-room is an excellent place for utilizing "flower-box" fixtures decorated with artificial foliage. In fact, a central fixture may assume the appearance of a "hanging basket" of foliage. The library and den offer no problems differing from those already discussed in the living-room. A careful consideration of the disposition of the furniture will reveal the best positions for the outlets. In a small library wall brackets may serve as decorative spots of light and if the shades are pendent they may serve as lamps for reading purposes. In both these rooms an excellent reading-lamp is desired, but it may be decorative as well. Wall outlets may be desired for decorative portable lamps upon the bookcases. The sleeping-room, which commonly is also a dressing-room, often exhibits the errors of a lack of foresight in lighting. In most rooms of this character there is one best arrangement of furniture and if this is determined it is easy to ascertain where the windows and outlets should be located. The windows may usually be arranged for twin beds as well as for a single one with obvious advantages of flexibility in arrangement. With the position of the bureau determined it is easy to locate outlets for two wall brackets, one on each side, about sixty-six inches above the floor and about five feet apart. When the brackets are equipped with dense upright shades, the figure before the mirror is well illuminated without glare and sufficient light reaches the ceiling to illuminate the whole room. A baseboard outlet should be available for small portable lamps which may be used upon the bureau or for electric heating devices. The same is true for the dressing-table; indeed, two small decorative lamps on the table serve better than high wall brackets owing to the fact that the user is seated. A baseboard outlet near the head of the bed or between the beds is convenient for a reading-lamp and for other purposes. An outlet in the center of the ceiling controlled by a convenient switch may be installed on building, as insurance against future needs or desires. But a single lighting-unit in the center of the ceiling does not serve adequately the needs at the bureau and dressing-table. In fact, two wall brackets properly located with respect to the bureau afford a lighting much superior for all purposes in the bedroom to that produced by a ceiling fixture. In the bath-room the principal problem is to illuminate the person, especially the face, before the mirror. Many mistakes are made at this point, despite the simplicity of the solution. In order to see the image of an object in a mirror, the object must be illuminated. It is best to do this in a straightforward manner by means of a small lighting-unit on each side of the mirror at a height of five feet. Both sides of the face will be well illuminated and the light-sources are low enough to eliminate objectionable shadows. The units may be merely pull-chain sockets containing frosted or opal lamps. A center bracket or a single unit suspended from the ceiling is not as satisfactory as the two brackets. These afford enough light for the entire bath-room. A baseboard or wall outlet is convenient for connecting a heater, curling-iron, and other electrically heated devices. The sewing-room, which in the middle-class home is usually a small room, is sometimes used as a bedroom. A ceiling fixture will supply adequate general lighting, but a baseboard outlet should be available for a short floor lamp or a table lamp for sewing purposes. An intense local light is necessary for this occupation, which severely taxes the eyes. A so-called daylight lamp serves very well in this case. [Illustration: OBTAINING TWO DIFFERENT MOODS IN A ROOM BY A PORTABLE LAMP WHICH SUPPLIES DIRECT AND INDIRECT COMPONENTS OF LIGHT] [Illustration: THE LIGHTS OF NEW YORK CITY Towering shafts of light defy the darkness and thousands of lighted windows symbolize man's successful struggle against nature] In the kitchen the wall brackets are easily located after the positions of the range, work-table, sink, etc., are determined. A bracket for each is advisable unless they are so located that one will serve two purposes. It is customary to have a combination fixture for gas and electricity. This is often suspended from the center of the ceiling, but inasmuch as the gas-light cannot be close to the ceiling, the fixture extends so far downward as to become a nuisance. Furthermore, a light-source hung low from the center of the ceiling is in such a position that the worker in the kitchen usually works in his shadow. If a ceiling outlet is used it should be an electrical socket at the ceiling. The combination fixture is best placed on the wall as a bracket. The so-called daylight lamps are valuable in the kitchen. In the basement a generous supply of ceiling outlets adds much to the satisfaction of a basement. One in each locker, one before the furnace, and a large daylight lamp above but to one side of the laundry trays are worth many times their cost. Furthermore, a wall socket for the electric iron and washing-machine is a convenience very much appreciated. In the stairways convenient three-way switches for each of the ceiling fixtures represents the best practice. A baseboard outlet in the upper hall affords a connection for a decorative lamp and pays for itself many times as a place to attach the vacuum-cleaner from which all the rooms on that floor may be served. In vestibules and on porches ceiling fixtures controlled by means of convenient switches are satisfactory. The entrance hall may be made to express hospitality by means of lighting which should be adequate and artistic. An adequate supply of outlets and wall switches is not costly and they pay generous dividends. With a scanty supply of these, the possibilities of lighting are very much curtailed. There is nothing intricate about locating switches and outlets, so the householder may do this himself, or he may view critically the plans as submitted. The chief difficulties are to throw aside his indifference and to readjust his ideas and values. It may be confidently stated that the possibilities of lighting far outrank most of the features which contribute to the cost of a house and of its furnishings. After considering the requirements and decorative schemes of the various rooms the householder should be competent to judge the appropriateness of the lighting effects obtained from fixtures which the dealer displays, but he should insist upon a demonstration. If the dealer is not equipped with a room for this purpose, he should be asked to demonstrate in the rooms to be lighted. If the fixture-dealer does not realize that he should be selling lighting effects, the householder should make him understand that lighting effects are of primary importance and the fixtures themselves are of secondary interest in most cases. The unused outlets that have been installed for possible future needs may be sealed in plastering if the positions are marked so that they may be found when desired. An advantage of portable lamps is that they may be taken away on moving. In fact, when lighting is eventually considered a powerful decorative medium, as it should be, it is probable that fixtures will be personal property attached to ceiling, wall, and floor outlets by means of plugs. A variety of incandescent lamps are available. For the home, opal, frosted, or bowl-frosted lamps are usually more satisfactory than clear lamps. Bare filaments should not be visible, for they not only cause discomfort and eye-strain but they spoil what might otherwise be an artistic effect. Lamps with diffusing bulbs do much toward eliminating harsh shadows cast by the edges of the shades, by the chains of the fixtures, etc. These lamps are available in many shapes and sizes and the householder should make a record of voltage, wattage, and shape of the lamps which he finds satisfactory in the various fixtures. The Mazda daylight lamp has several places in the home and the Mazda white-glass and other high-efficiency lamps supply many needs better than the vacuum lamps. In brackets and other purely decorative lighting-units small frosted lamps are usually the most satisfactory. There is a general desire for the warm yellowish light of the candle-flame, and this may be obtained by a tinted shade but usually more satisfactorily by means of a tinted lamp. The householder will find it interesting to become intimate with lighting, for it can serve him well. The housewife will often find much interest in making shades of textiles and of parchment. Charming glassware in appropriate tints and painted designs is available for all rooms. In the bedchamber and the nursery some of these painted designs are exceedingly effective. Fixtures should shield the lamps from the eyes, and the diffusing media whether glass or textile should be dense enough to prevent glare. No fixture can be beautiful and no lighting effect can be artistic if glare is present. If the architect and the householder will realize that light is a medium comparable with the decorator's media, better lighting will result. Light has the great advantage of being mobile and with adequate outlets and controls supplemented by fixtures from which different effects are available, the householder will find in lighting one of the most fruitful sources of interest and pleasure. It can do much toward expressing the taste of the householder or if neglected it can undo much of the effect of excellent decoration and furnishing. Artificial lighting, softly diffused and properly localized, is one of the most important factors in making a house a home. XXV LIGHTING--A FINE ART? In the preceding chapters the progress of light has been sketched from its obscure infancy to its vigorous youth of the present time. It has been seen that progress was slow until the beginning of the nineteenth century, after which it began to gain momentum until the present century has witnessed tremendous advances. Until the latter part of the nineteenth century artificial light was considered an expensive utility, but as modern lamps appeared which supplied adequate light at reasonable cost attention began to be centered upon utilization, and the lighting engineer was born. Gradually it is being realized that artificial light is no longer a luxury, that it may be used in great quantity, and that it may be directed, diffused, and altered in color as desired. Although the potentiality of light has been barely drawn upon, the present usages surpass the most extravagant dreams of civilized beings a half-century ago. Mere light of that time was changed into more light as gas-lighting developed, and more light has increased to adequate light of the present time through the work of scientists. It is apparent that a sudden enforced reversion to the primitive flames of fifty years ago would paralyze many activities. Much of interest and beauty would be blotted out of this brilliant, pulsating, productive age. It is startling to note that almost the entire progress in artificial lighting has taken place during the past hundred years and that most of it has been crowded into the latter part of this period. In fact, its development since it began in earnest has gone forward with ever-increasing momentum. On viewing the wonders of modern artificial lighting on every hand it is not difficult to muster the courage necessary to venture into its future. The lighting engineer has been a natural evolution of the present age, for the economic aspects of lighting have demanded attention. He is increasing the safety, efficiency, and happiness of mankind and civilization is beginning to feel his influence economically. However, with the advent of adequate, efficient, and controllable light, the potentiality of light as an artistic medium may be drawn upon and the lighting artist with a deep insight into the possibilities of artificial light now has his opportunity. But the artist who believes that a new art may be evolved to perfection in a few years is doomed to disappointment, for it is necessary only to view retrospectively such arts as painting and music to be convinced that understanding and appreciation develop slowly through centuries of experiment and contact. Will lighting ever become a fine art? Will it ever be able alone to arouse emotional man as do the fine arts? Are the powers of light sufficiently great to enthrall mankind without the aid of form, music, action, or spoken words? It is safer to answer "yes" than "no" to these questions. Painting has reached a high place as an art and this art is the expressiveness of secondary or reflected light reinforced by imitation forms, which by a combination of light and drawing comprise the "subjects." A painting is a momentary expression of light, a cross-section of something mobile, such as nature, thought, or action. Light has the essential qualifications of painting with the advantages of a greater range of brightness, of greater purity of colors, and the great potentiality of mobility. If lighting becomes a fine art it will doubtless be related to painting somewhat in the same manner that architecture is akin to sculpture. With the introduction of mobility it will borrow something from the arts of succession and especially from music. The art of lighting in its present infancy is leaning upon established arts, just as the infant learns to walk alone by first depending upon support. The use of color in painting developed slowly, being supported for centuries by the strength of drawing or subject. The landscapes of a century ago were dull, for color was employed hesitatingly and sparingly. The colors in the portraits of the past merely represented the gorgeous dress of bygone days. But the painter of the present shows that color is beginning to be used for itself and that the painter is no longer hesitant concerning its power to go hand in hand with drawing. Drafting and coloring are now in partnership, the former having given up guardianship when the latter reached maturity. Lighting is now an accompaniment of the drama, of the dance, of architecture, of decoration, and of music. It has been a background or a part of the "atmosphere" excepting occasionally when some one with imagination and daring has given it the leading rôle. Even in its infancy it has on occasions performed admirably almost without any aid. The bursting rocket, the marvelous effects at the Panama-Pacific Exposition, and some of the exhibitions on the theatrical stage are glimpses of the potentiality of light. To fall back upon the terminology of music, these may be glimmerings of light-symphonies. Harmony is simultaneity and a painting in this respect is a chord--a momentary expression fixed in material media. A melody of light requires succession just as the melody in music. The restless colors of the opal comprise a light melody like the songs of birds. The gorgeous splendor of the sunset compares in magnitude and in its various moods with the symphony orchestra and its powers. Throughout nature are to be found gentle chords, beautiful melodies and powerful symphonies of light and this music of light exhibits the complexity and structure analogous to music. There is no physical relation between music, poetry, and light, but it is easy to lean upon the established terminology for purposes of discussion. Those who would build color-music identical to sound music are making the mistake of starting with a physical foundation instead of basing the art of light-expression upon psychological effects of light. In other words, a relation between light and music can exist only in the psychological realm. These melodies and symphonies of light in nature are admittedly pleasing or impressive as the case may be, but are they as appealing as music, poetry, painting, or sculpture? The consensus of opinion of a large group of average persons might indicate a negative reply, but the combined opinion of this group is not so valuable as the opinion of a colorist or of an artist who has sensed the wonders of light. The unprejudiced opinion of artists is that light is a powerfully expressive and impressive medium. The psychologist will likely state that the emotive value of light or color is not comparable to the appeal of an excellent dinner or of many other commonplace things. But he has experimented only with single colors or with simple patterns and his subjects are selected more or less at random from the multitude. What would be his conclusion if he examined painters and others who have developed their sensibilities to a deep appreciation of light and color? It is certain that the painter who picks up a purple petal fallen from a rose and places it upon a green leaf is as thrilled by the powerful vibrant color-chord as the musician who hears an exquisite harmony of sounds. Music has been presented to civilized mankind in an organized manner for ages and the fundamental physical basis of modern music is a thousand years old. Would the primitive savage appreciate the modern symphony orchestra? Even the majority of civilized beings prefer the modern ragtime or jazz to the exquisite art of the symphony. An appreciation of the opera and the symphony is reached by educational methods extending over long periods. An appreciation of the expressiveness of light cannot be expected to be realized by any short-cut. Most persons to-day enjoy the melodramatic "movie" more than the drama and relatively few experience the deep appeal of the fine arts. Surely the symphony of light cannot be justly condemned because of a lack of appreciation and understanding of it, for it has not been introduced to the public. Furthermore, the expressiveness of music is still indefinite at best despite the many centuries of experimenting on the part of musicians. If poetry is to be believed, the symphonies of light as rendered by nature in the sunsets, in the aurora borealis, and in other sky-effects of great magnitude have deeply impressed the poet. If his descriptions are to be accepted at their face-value, the melodies of light rendered in the precious stone, in the ice-crystal, and in the iridescence of bird-plumage please his finer sensibilities. If he is sincere, mobile light is a seductive agency. The painter has contributed little of direct value in developing the music of light. He is concerned with an instantaneous expression. He waits for it patiently and, while waiting, learns to appreciate the fickleness of mood in nature, but when he fixes one of these moods he has contributed very little to the art of mobile light. Unfortunately the art schools teach the student little or nothing pertaining to color for color's sake. When the student is capable of drawing fairly well and is acquainted with a few stereotyped principles of color-harmony he is sent forth to follow in the footsteps of past masters. He may be seen at the art museum faithfully copying a famous painting or out in the fields stalking a tree with the hopes of an embryo Corot. The world moves and has only a position in the rank and file for imitators. Occasionally an artist goes to work with a vim and indulges in research, thereby demonstrating originality in two respects. Painting is just as much a field for research as light-production. Recently experiments are being made in the production of color-harmonies devoid of form. Surely there is a field for pure color-composition and this the field of the painter which leads toward the art of mobile light. Many of the formless paintings of the present day which pass under the banner of this _ism_ or that are merely experiments in the expressiveness of light. Being formless, they are devoid of subject in the ordinary sense and cannot be more or less than a fixed expression of light. Naturally they have received much criticism and have been ridiculed, but they can expect nothing else until they are understood. They cannot be understood until mankind learns their language and then they must be understandable. In other words, there are impostors gathered around the sincere research-artist because the former have neither the ability to paint for a living nor the inclination to forsake the comparative safety of the mystery of art for the practical world where their measure would be quickly taken. This army of camp-followers will not advance the art of mobile light, but the sincere seekers after the principles of light-expression who form the foundation of the various _isms_ may contribute much. The painter will always be available with his finer sensibility to appreciate and to aid in developing the art of mobile light, but his direct contribution appears most likely to come from the present chaos of experiments in pure color-composition, in the psychology of light, or, more broadly, in the expressiveness of light. The decorator and the designer of gowns and costumes do not arrogate to themselves the name "artist," but they are daily creating something which is leading toward a fuller appreciation of the expressiveness of light. If they do not contribute directly to the development of the art of mobile light, they are at least aiding in developing what may eventually be an appreciative public. The artist paints a "still-life," the decorator creates a color-harmony of abstract or conventional forms, and the costumer produces a color-composition in textiles. The decorator and costumer approach closer to pure color-composition than the artist in his still-life. The latter is a grouping of objects primarily for their color-notes. Why bother with a banana when a yellow-note is desired? Why utilize the abstract or conventional forms of the decorator? Why not follow this lead further to the less definite forms employed by the costumer? Why not eliminate form even more completely? This is an important point and an interesting lead, for to become rid of form has been one of the perplexing problems encountered by those who have dreamed of an art of mobile light. The painter who uses line and color imitatively has perhaps acquired skill in depicting objects and more or less appreciation of the beautiful. But if he is to be creative and to produce a higher art he must be able to use line and color without reference to objects. He thus may aid in the development of an abstract art which is the higher art and at the same time aid in educating the public to appreciate pure color-harmonies. From these momentary expressions of light and from the experience gained, the mobile colorist would receive material aid and his productions would be viewed by a more receptive audience or rather "optience" as it may be called. The development of taste for abstract art is needed in order that the art of mobile light may develop and, incidentally, an appreciation of the abstract in art is needed in all arts. Science has contributed much by way of clearing the decks. It has produced the light-sources and the apparatus for controlling light. It has analyzed the physical aspects of color-mixture and has accumulated extensive data pertaining to color-vision. It has pointed out pitfalls and during recent years has been delving further by investigating the psychology of light and color. The latter field is looked to for valuable information, but, after all, there is one way of making progress in the absence of data and that is to make attempts at the production of impressive effects of mobile light. Some of these have been made, but unfortunately they have been heralded as finished products. Perhaps the most general mistake made is in relating sounds and colors by stressing a mere analogy too far. Notwithstanding the vibratory nature of the propagation of sound and light, this is no reason for stressing a helpful analogy. After all it is the psychological effect that is of importance and it is absurd to attribute any connection between light-waves and sound-waves based upon a relation of physical quantities. No space will be given to such a relation because it is so absurdly superficial; however, the language of music will be borrowed with the understanding that no relation is assumed. A few facts pertaining to vision will indicate the trend of developments necessary in the presentation of mobile light. The visual process synthesizes colors and at this point departs widely from the auditory process. The sensation of white may be due to the synthesis of all the spectral colors in the proportions in which they exist in noon sunlight or it may be due to the synthesis of proper proportions of yellow and blue, of red, green, and blue, of purple and green, and a vast array of other combinations. A mixture of red and green lights may produce an exact match for a pure yellow. Thus it is seen that the mixture of lights will cause some difficulty. For example, the components of a musical chord may be picked out one by one by the trained ear, but if two or more colored lights are mixed they are merged completely and the resultant color is generally quite different from any of the components. In music of light, the components of color-chords must be kept separated, for if they are intermingled like those of musical chords they are indistinguishable. Therefore, the elements of harmony in mobile light must be introduced by giving the components different spatial positions. The visual process is more sluggish than the auditory process; that is, lights must succeed each other less rapidly than musical notes if they are to be distinguished separately. The ear can follow the most rapid execution of musical passages, but there is a tendency for colors to blend if they follow one another rapidly. This critical frequency or rate at which successive colors blend decreases with the brightness of the components. If red and green are alternated at a rate exceeding the critical frequency, a sensation of yellow will result; that is, neither component will be distinguishable and a steady yellow or a yellow of flickering brightness will be seen. The hues blend at a lower frequency than the brightness components of colors; hence there may be a blend of color which still flickers in brightness. Many weird results may be obtained by varying the rate of succession of colors. If this rate is so low that the colors do not tend to merge, they are much enriched by successive contrast. It is known that juxtaposed colors generally enrich one another and this phenomenon is known as simultaneous contrast. Successive contrast causes a similar effect of heightened color. An effect analogous to dynamic contrast in music may be obtained with mobile light by varying the intensity of the light or possibly the area. Melody may be simply obtained by mere succession of lights. Tone-quality has an analogy in the variation of the purity of color. For example, a given spectral hue may be converted into a large family of tints by the addition of various amounts of white light. Rhythm is as easily applied to light as to music, to poetry, to pattern, or to the dance, but in mobile lights its limitations already have been suggested. However, it is bound to play an important part in the art of mobile light because rhythmic experiences are much more agreeable than those which are non-rhythmic. Rhythm abounds everywhere and nothing so stirs mankind from the lowliest savage to the highly cultivated being as rhythmic sequences. Many psychological effects of light have been recorded from experiment and observation and affective values of light have been established in various other byways. It is possible that the degree of pleasure experienced by most persons on viewing a color-harmony or the delightful color-melody of a sunlit opal may be less than that experienced on listening to the rendition of music. However, if this were true it would offer no discouragement, because absolute values play a small part in life. Two events when directly compared apparently may differ enormously in their ability to arouse emotions, but the human organism is so adaptive that each in its proper environment may powerfully affect the emotions. For example, those who have sported in aërial antics in the heights of cloudland or have stormed the enemy's trench are still capable of enjoying a sunset or the call of a bird to its mate at dusk. The wonderful adaptability of the inner being is the salvation of art as well as of life. In the rendition of mobile light it is fair to give the medium every advantage. Sometimes this means to eliminate competitors and sometimes it means to remove handicaps. On the stage light has had competitors which are better understood. For example, in the drama words and action are easily understood, and regardless of the effectiveness of light it would not receive much credit for the emotive value of the production. In the wonderful harmony of music, dance, and light in certain recent exhibitions, the dance and music overpowered the effects of lights because they speak familiar languages. [Illustration: A community Christmas tree A community song-festival ARTIFICIAL LIGHT IN COMMUNITY AFFAIRS] [Illustration: PANAMA-PACIFIC EXPOSITION Artificial light not only reveals the beauty of decoration and architecture but enthralls mankind with its own unlimited powers] A number of attempts have been made to utilize light as an accompaniment of music and some of them on a small scale have been sincere and creditable, but a much-heralded exhibition on a large scale a few years ago was not the product of deep thought and sincere effort. For example, colored lights thrown upon a screen having an area of perhaps twenty square feet were expected to compete with a symphony orchestra in Carnegie Hall. The music reached the most distant auditor in sufficient volume, but the lighting effect dwindled to insignificance. Without entering into certain details which condemned the exhibition in advance, the method of rendition of the light-accompaniment revealed a lack of appreciation of the problems involved on the part of those responsible. Incidentally, it has been shown that the composer of this particular musical selection with its light accompaniment was psychologically abnormal; that is, he was affected with colored audition. It is not yet established to what extent normal persons are similarly affected by light and color. Certainly there is no similarity among the abnormal and none between the abnormal and normal. If light is to be used as an accompaniment to music, it must be given an opportunity to supply "atmosphere." This it cannot do if confined to an insignificant spot; it must be given extensity. Furthermore, by the use of diaphanous hangings, form will be minimized and the evanescent effects surely can be charming. But finally the lighting effects must fill the field of vision just as the music "fills the field of audition" in order to be effective. There are fundamental objections to the use of mobile light as an accompaniment to music and therefore the future of the art of mobile light must not be allowed to rest upon its success with music. If it progresses through its relation with music, so much is gained; if not, the relation may be broken for music is quite capable of standing alone. There is a tendency on the part of some revolutionary stage artists to give to lighting an emotional part in the play, or, in other words, to utilize lighting in obtaining the proper mood for the action of the play. Color and purely pictorial effect are the dominant notes of some of them. All of these modern stage-artists are abandoning the intricately realistic setting, and, as a consequence, light is enjoying a greater opportunity. In the more common and shallow theatrical production, lighting and color effects have many times saved the day, and, although these effects are not of the deeper emotional type, they may add a spectacular beauty which brings applause where the singing is mediocre and the comedy isn't comedy. The potentiality of lighting effects for the stage has been barely drawn upon, but as the expressiveness of light is more and more utilized on the stage, the art of mobile light will be advanced just so much more. Light, color, and darkness have many emotional suggestions which are easily understood and utilized, but the blending of mobile light with the action is difficult because its language is only faintly understood. It is futile to attempt to describe a future composition of mobile light. Certainly there is an extensive variety of possibilities. A sunset may be compressed into minutes or an opalescent sky may be a motif. Varying intensities of a single hue or of allied hues may serve as a gentle melody. Realistic effects may be introduced. The expressiveness of individual colors may be taken as a basis for constructing the various motifs. These may be woven into melody in which rhythm both in time and in intensity may be introduced. Action may be easily suggested and the number of different colors, in a broad sense, which are visible is comparable to the audible tones. Shading is as easily accomplished as in music and the development of this art need not be inhibited by a lack of mechanical devices and light-sources. The tools will be forthcoming if the conscientious artist requests them. Whatever the future of the art of mobile light may be, it is certain that the utilization of the expressiveness of light has barely begun. It may be that light-music must pass through the "ragtime" stage of fireworks and musical-revue color-effects. If so, it is gratifying to know that it is on its way. Certainly it has already served on a higher level in some of the artistic lighting effects in which mobility has featured to some extent. If the art does not develop rapidly it will be merely following the course of other arts. A vast amount of experimenting will be necessary and artists and public alike must learn. But if it ever does develop to the level of a fine art its only rival will be music, because the latter is the only other abstract art. Material civilization has progressed far and artificial light has been a powerful influence. May it not be true that artificial light will be responsible for the development of spiritual civilization to its highest level? If mobile light becomes a fine art, it will be man's most abstract achievement in art and it may be incomparably finer and more ethereal than music. If this is realized, artificial light in every sense may well deserve to be known as the torch of civilization. READING REFERENCES No attempt will be made to give a pretentious bibliography of the literature pertaining to the various aspects of artificial lighting, for there are many articles widely scattered through many journals. _The Transactions of the Illuminating Engineering Society_ afford the most fruitful source of further information; the _Illuminating Engineer_ (London), contains much of interest; and _Zeitschrift für Beleuchtungswesen_ deals with lighting in Germany. H. R. D'Allemagne has compiled an elaborate "Historie du Luminaire" which is profusely illustrated, and L. von Benesch in his "Beleuchtungswesen" has presented many elaborate charts. In both these volumes lighting devices and fixtures from the early primitive ones to those of the nineteenth century are illustrated. A few of the latest books on lighting, in the English language, are "The Art of Illumination," by Bell; "Modern Illuminants and Illuminating Engineering," by Gaster and Dow; "Radiation, Light and Illumination," by Steinmetz; "The Lighting Art," by Luckiesh; "Illuminating Engineering Practice," consisting of a course of lectures presented by various experts under the joint auspices of the University of Pennsylvania and the Illuminating Engineering Society; "Lectures on Illuminating Engineering," comprising a series of lectures presented under the joint auspices of Johns Hopkins University and the Illuminating Engineering Society; and "The Range of Electric Searchlight Projectors," by Rey; "The Electric Arc," by Mrs. Ayrton; "Electric Arc Lamps," by Zeidler and Lustgarten, and "The Electric Arc," by Child treat the scientific and technical aspects of the arc. G. B. Barham has furnished a book on "The Development of the Incandescent Electric Lamp." "Color and Its Applications," and "Light and Shade and Their Applications," are two books by Luckiesh which deal with lighting from unique points of view. "The Language of Color," by Luckiesh, aims to present what is definitely known regarding the expressiveness and impressiveness of color. W. P. Gerhard has supplied a volume on "The American Practice of Gaspiping and Gas Lighting in Buildings," and Leeds and Butterfield one on "Acetylene." A recent book in French by V. Trudelle treats "Lumière Electrique et ses différentes Applications au Théatre." Many books treat of photometry, power-plants, etc., but these are omitted because they deal with phases of light which have not been discussed in the present volume. "Light Energy," by Cleaves, is a large volume devoted to light-therapy, germicidal action of radiant energy, etc. References to individual articles will often be found in the various indexes of publications. THE END INDEX Aaron, 43 Accidents: 8; street-lighting in relation to, 225 _et seq._; percentage (table) of, due to improper lighting, 231 Acetylene: 62; light-yield of, 106, 107, 170, 187, 191 Actinic rays: effect of, upon human organism, 275 Africa, public lighting in ancient, 31 Agni, god of fire, 40 Air-pump, 130 Air-raids, 225 Alaska, 18, 29 Alchemy, 20 Aleutians, 18 Alexandria, 43, 163 Allylene, 106 Aluminum, 108, 179, 180 Amiens, Treaty of, 69 Amylene, 106 Aniline dyes, 106 Animal: distinction between, and human being, 3; 15; production of light, 24 _et seq._; sources of light, 30, 31; oils, 51 Antimony, 294 Antioch, 153 Arago, 114, 196 Archbishop of Canterbury, 49 Archimedes, 19 Arc: lamps, 69, 89; electric, 111 _et seq._; distinction between spark and, 112; Davy's notes on electric, 113; formation of, 115, 116; Staite and enclosed, 117, 118; principle of enclosed, 118, 119; types of, 120; flame-, 121, 122; luminous, 122; electric, 127; luminous efficiency of electric (table), 124; 160 _et seq._; -lamp in lighthouses, 168 _et seq._; magnetite-, 187; 261 Ardois system of signaling, 199 Argand, Ami: 52; inaugurates new era in artificial lighting, 53, 54; 63, 70, 76, 77, 78, 97, 167, 196 Argon, 137 Aristophanes, "The Clouds," 19 Art Museums, 9, 13, 322, 323 Asbestos, 170 Asia: public lighting in ancient, 31, 39 Automobiles, 238 Babylon, 39 Bacteria: effect of artificial light upon, 272 _et seq._; 281, 282 Bailey, Prof. L. H., 250 Baltimore, 98 Bamboo: carbon filaments, 169 Bartholdi, 302, 303 Beacons. _See_ Lighthouses. Beck, 186 Beecher, 72 Beeswax, 35, 51 Benzene, 106 Bible, cited on importance of artificial light, 42-44 "Bluebird, The," Maeterlinck, 9 Blue-prints, 261 Bollman, 98 Bolton, von, 132, 133 Bombs, illuminating, 182 _et seq._ Boston Light, 164, 165, 166, 177 Bowditch, production of regenerative lamp by, 78, 79 Boy Scouts, 17 Bremer, 120 Bristol University, 252 Brush, 68, 159 Building, 8 Bunsen, 81, 85, 89, 148, 149 Bureau of Mines: cited on open flames, 234; 236 Burning-glasses, 19, 20. _See also_ Lenses. Butylene, 106 Byzantium, 34 Cæsar, 163 Canada, 254 Candle-hour, defined, 215 Candles: progress and, 7; 25, 28, 29, 30, 33; religious uses of, 34, 35; as a modern light-source, 36, 37; ceremonial uses of, 38 _et seq._; 44, 48, 57, 82, 97, 222, 299, 304 Calcium, 107, 108 Carbolic acid, 106 Carbon: 53, 80, 81; physical characteristics of, 80, 81; 90, 104, 105, 128, 129, 144, 170 Carbon filament: 127 _et seq._; preparation of, 129, 130, 131; luminous efficiency of, 131, 132; lamps, 161; lamps in greenhouses, 250 _et seq._ Carbons, formation of, 115, 116 Carbureted hydrogen, 75 Carcel, invention of clockwork lamp by, 54, 55 Cat-gut, 130 Ceria, 85, 101 Charleston, S. C., 185 Charcoal: 113; uses of, for electrodes, 115 Chartered Gas Light and Coke Co., London, 74 Chemistry: artificial light and, 256-268 Chicago, 62, 304, 305 Chimneys, 54, 60, 62 China, 19, 31, 32 Chlorate of potash, 22 Christ, 33, 46, 47 Christians, "children of light," 42 Christmas trees, 43, 304 Chromium, 294 Church of England, 49 Cities: economy of artificial lighting in congested, 13 Civilization: effect of artificial light upon, 4 _et seq._; fire and, 15 Clark, Parker and, 139 Clayton, Dr.: invention of portable gas-light by, 64; quoted, 64, 65; experiments of, with coal-gas, 67 Claude, 147 Cleaves, Dr., quoted, 276, 277 Clegg, Samuel: 74; gas-lighting accomplishments of, 75, 76 Cleveland, 159 "Clouds, The," Aristophanes, 19 Coal: 32; as a light-source, 55; supply, 223; 228 Coal-gas: 63 _et seq._; public lighting by, developed, 70 _et seq._; analytical production of, 103, 104; yield of, retort (table), 105; analysis of, 106 Coal-mines, 234 _et seq._ Cobalt, 294 Coke, 68, 105 Cologne, 157, 158 Colomb, Philip, 197 Color: 9; relation of artificial light to, 284 _et seq._ Colza, 31, 52, 167 Combustion, 82 _et seq._ Commerce, 8, 97 Constantine, 42 Copper, 262, 295 Cornwall, 63 Cotton: 101; carbon filaments, 129, 130 Cromartie, 78 Crookes, 90, 146 Crosley, Samuel, improvement of gas-meter by, 76 Crusies, 32 Daguerre, 258 Dancing, 346 Davy, Sir Humphrey: 33, 68, 73; first use by, of charcoal for sparking points, 112; notes of, on electric arc, 113; 114 Daylight, artificial, 12: 284 _et seq._; application of, 287 Daylighting, 12-14 Dollond, 195 Doty, 61, 167 Drake, Col. E. L., discovery of oil in Pennsylvania by, 56 Drummond, Thomas: 171, 185, 196; quoted on signaling, 197 Dudgeon, Miss, 251, 252 Dyes, 256, 265 East Indies, 29 Eddystone Light, 166, 167 Edison: and problem of electric incandescent filament lamps, 128 _et seq._; 129; quoted on birth of incandescent lamp, 130 Edward I, 274 Edward VI, 49 Efficiency, effect of artificial light upon, 14 Eggs: relation of artificial light to production of, 247, 248 Egypt: 31; sacredness of light in ancient, 39; 153, 195 Electric filament: 81, 127 _et seq._: approximate value of, lamps (table), 138 Electric pile: construction of, 111; 127 Electricity: 13, 22; as a light-source, 57; for home-lighting, 62, 84; 87, 89; ignition of gas by, 102; lighting by, 109 _et seq._ Electromagnetic waves, 68, 86, 87 Electromagnets, 114, 116 Electrodes, 113, 114, 115 _et seq._; life of, 122 Elizabeth, Queen, 274 England: 32; petroleum discovered in, 56; gas-lighting in, 63 _et seq._; 166, 251, 274 Erbia, 85 Esquimaux: 18; use of artificial light by, 31 Ethylene, 106 Factories: 13; artificial light in, 239 _et seq._ Faraday, 113 Filaments, carbon, 129 _et seq._ Finsen: 273, 274, 275; on stimulating action of artificial light, 277; 279, 280 Fire: importance of, to man, 5 _et seq._; man's dependence upon, 15; mythical origin of, 16; making, 17 _et seq._; production of, in the stone age, 18; in early civilization, 19; ancient worship of, 29, 299 Fireflies: 24, 81, 96, 148, 149, 150 "First Men in the Moon, The," H. G. Wells, cited, 148 Fish: artificial light as bait for, 249 Flame-arcs, 120, 121, 122, 187 Flames: 86, 88, 89; open, 233, 234 _et seq._ Flint, 33 Fool's gold, 18 Fort Wagner, 185 France: lamps in, 55; early gas-light in, 72 Franchot, invention of moderator lamps by, 55 Frankland, 77 Franklin, Benjamin: 165; quoted, 210-212; 213 Fresnel, 167, 196 Friction, 16, 17 Gas: 13, 22; discovery of coal, 32, 33; early uses of, as light-source, 63 _et seq._; installment of, pipes in England, 63, 64; Shirley's report on Natural, 66, 67; first public display of, lighting, 69; cost of, lighting, 71; first attempt at industrial, lighting, 72; first English, company, 74; first, explosion, 75; house, lighting, 76, 77; 80, 82; spectrum of, 90; modern, lighting industry, 97 _et seq._; origin of lighting by, 98; first, works in America, 98; growth of, consumption in United States, 99; electrical ignition applied to, lighting, 102; pressure, 102, 103; water, 105; carbons in, 106; production of Pintsch, 109, 110; salts applied to, flames, 120; 157; Census Bureau figures on cost of, plants, 221, 222; 224, 341 Gas-burners: 63, 64, 77; candle-power of pioneer (table), 79; improvements in, 84 Gas-mantle: 61, 81; influence of, 99; characteristics of, 100 _et seq._; 187 Gas-meter, Clegg's, 76 Gasolene: lamps, 55; 57 Gassiot, 114 Gauss, 196 Geissler, 146 General Electric Company, 132, 135, 136 Germany: development of lamps in, 56; early gas-lighting in, 72 Glass, 195, 290 _et seq._ Glowers, 139 Glow-worms, 24 Glycerides, 52 Gold, 293 Gout, 275 Gramme dynamo, 117 Grass: 18; carbon filaments, 129 Greece: 39; sacred lamps in ancient, 41; 42 Greenhouses, carbon-filament lamps in, 250 _et seq._ Hall of Fame, 134 Happiness, effect of artificial light upon, 14 Hayden and Steinmetz, 253 Health, artificial light in relation to, 269-283 Helium, 89 Hemig, 155 Hemp, 21 Henry, William, 75 Herodotus, 56 Hertz, 68 Hertzian waves, 271 Hewitt, Cooper, produces mercury-arcs, 124, 125 Home: artificial light in relation to, 6; lighting, 325 _et seq._ Hindu: light in, ceremonials, 40 Hudson-Fulton Celebration, 306 Huygens, 195 Hydrocarbons, 82 Hydrogen, 81 Illiteracy, artificial light and, 9 Invention, 7, 97 Iowa, 238 Iridium, 129 Iron, 18, 262, 294 Iron pyrites, 18 Italy, 249 Jablochkov: electric candle of, 117 Jamaica, 19 Jandus, 118, 122 Japan: 19; use of oil in, 30; 281 Jerusalem, 43 Jews: artificial light among, 40 _Journal_, Paris, quoted, 210-212 Kerosene: 57; weight of, lumens, 60; 62, 187, 233 Kitson, platinum-gauze mantle applied by, 61 Laboratories: achievements of, 137 Lamps: 16, 25; Roman, 30; 31; invention of safety, 33; ancient funereal, 39; sacred, of antiquity, 41; ceremonial, 44; scientific development of oil, 51 _et seq._; Holliday, 55; Carcel, 54, 55; Franchot's moderator, 55; gasolene, 55; development of, in Germany, 56; air pressure, 61; supremacy of oil, ends, 62; Bowditch's, 77, 78; 80, 97; mercury-arc, 126; electric incandescent filament, 127 _et seq._; gem, 132; tungsten, 133 _et seq._; luminous efficiency (table) of incandescent filament, 141; 299; in home, 328-333 Lange, 167 Lard-oil, 51 Lavoisier, 195 Lead, 262, 294 Le Bon, 72 "Legend of Montrose, The," Scott, cited on primitive lighting, 27 Leigh, Edmund, quoted, 226 Lenses, 20, 171 _et seq._ Libanius, quoted, 153, 154 Liberty, Statue of, 301, 302, 303 Libraries, 9 Light: relation of artificial, to progress, 3 _et seq._; as a civilizing agency, 3-14; primitive man and artificial, 4; Milton, quoted on importance of, 5; artificial, and science, 7; artificial, and industrial development, 8; Maeterlinck's tribute to, 9; Lincoln's debt to artificial, 9; symbolism of, 9, 10; therapy, 10; in war, 11; adaptations of, 12; 13; mythical origin of artificial, 16; earliest source of, 16; production of, in stone age, 18; matches as source of, 21; animals as, sources, 24, 25; primitive sources of, 24-37; evolution of artificial, sources, 24-37; development, 28 _et seq._; early outdoor use of artificial, 28; Roman uses of artificial, 30; beginning of scientific, 33, 34; candles as modern, source, 36, 37; symbolism and religious uses of, 38 _et seq._; Bible cited on artificial, 42-44; in relation to worship, 43, 45, 46; Argand's contribution to, 53, 54; coal as, source, 55; early uses of gas as, source, 63 _et seq._; as a public utility, 70; first installation of industrial gas, 72; science of, production, 80 _et seq._; causes of, radiation, 80, 81; 83; lime, 84; electric, 89 _et seq._; principle of, production, 90, 91; sources, 93; various gas-burners', supply, 95; relative efficiency of, sources, 95, 96; in the home, 97; influence of, upon science, invention, and commerce, 97 _et seq._; yield of acetylene, 106, 107; electric, 109; influence of gas upon development of artificial, 110; development of artificial, 111 _et seq._; efforts to improve color of mercury-arc, 125; electric-incandescent-filament, 127 _et seq._; effect of tungsten, upon, 133 _et seq._; of the future, 143-152; in warfare, 178-193; signaling, 194-207; cost of, 208-224; and safety, 225 _et seq._; improper use of, 229, 230; comparison of daylight and artificial, 240; reducing action of, 258; bactericidal action of, 272 _et seq._; modifying, 284 _et seq._; spectacular uses of, 298-309; expressiveness of, 310-324; utility of modern, 325-340; evolution of the art of applying, 341-356; mobile, 347, 348, 349, 350; psychological effect of, 351 _et seq._; as an accompaniment to music, 352-354 Light-buoys, 10, 169 Lighthouses: 10, 163-177; optical apparatus of, 172 _et seq._ Light-ships, 10, 169 Lighting-systems: comparison of, 12-14 Lime, 84, 107, 108, 294 Lincoln, Abraham, 9 Linen, 18 Link-buoys, 28 Lithopone, 265, 266 Liverpool, 167 Living: comparison of, standards, 238 _et seq._ London, 152, 154, 155, 156, 157, 202 London Gas Light and Coke Company, 74 Lucigen, 61 Lumen-hour: defined, 215 Lumens: 60, 94, 215 Lutheran Church, 49 Lyceum Theatre, London, 73 Maeterlinck, Maurice, 9 Magazines, 8 Magdsick, H. H., 303 Magnesia: 84; Nernst's application of, 138 Magnesium, 179, 180 Magnetite arc, 187 Man: distinction between, and animal, 3; artificial light and early, 4; light-sources of primitive, 25 Manganese, 262, 268, 294 Mangin, 188 Mann, 129 Mantles, 95 Manufacturing, 8 Marconi, 68 Marks, 118 Matches: as light-sources, 21; 22, 82 Maxwell, 68 Mazda lamps, 289, 339 Mecca, 40 Mediterranean Sea, 163 Mercury-arc: Way's, 124; 125, 126; quartz, 125, 126; attempts to improve color of, light, 125 Middle Ages, 46, 47, 474 Milton, quoted, 5 Mirror, 19 Mohammedans, 40 Moore, Dr. McFarlan, 146, 147 Morality, effect of light upon, 9 Morse code: application of, to light-signaling, 198, 199 Moses, 195 Moving-pictures, 9, 260, 261 Munich, 72 Murdock, William: installment of gas-pipes by, 63; 68, 69, 70; quoted on industrial use of artificial, 71; 72, 73, 74, 76, 78, 217, 309 Museums: 13; utilization of artificial light by, 322, 323 Music: light as an accompaniment to, 352-354 Mythology, 16 Nantes, 85 Napoleon, 111 Napthalene, 106 National Heat and Light Co., 72, 74 Natural gas, 99 Navesink Light, 206 Nernst, 138, 139 Newspapers, 8 Newton, Sir Isaac: 7; quoted on discovery of visible spectrum, 87; 88 New York, 98, 165, 166, 206, 302, 304 Niagara Falls, 108, 306 Nickel, 262 Nielson, 77 Niepce, 258 Niter, 21 Nitrogen, 137 Norfolk, 169 Obesity, 275 Offices, 13 Oil: as a light-source, 29 _et seq._; development of, lamps, 51 _et seq._; 155; in lighthouse, 165 _et seq._; 222, 224, 299 O'Leary, Mrs., and her lamp, 62 Olive-oil, 51, 52, 167 Orkney Islands, 29, 177 Osmium, 133 Oxygen: relative consumption of, by oil-lamps, 58, 59; 262 Ozone, 262 Painting, 342, 343, 347, 348, 349 Pall Mall, 74 Panama-Pacific Exposition: 304; artificial lighting of, 306, 307, 308, 309 Paper: 18; carbon filaments, 129, 130 Paraffin, 35, 57 Parker and Clark, 139 Paris: experimental gas-lighting in, 83, 84; Volta in, 111; 154, 185, 210, 212, 213 Peckham, John, 195 Pennsylvania: discovery of oil in, 56 Periodic Law, 145 Petroleum: 35, 51, 55; discovery of, 56; constitution of crude, 57; 58, 214 Pharos, 163 Philadelphia, 98, 99, 157 Phillips and Lee, 70, 72 "Philosophical Transactions of the Royal Society of London," 33; quoted on industrial lighting, 63; Shirley's report on natural gas in, 66, 67; quoted, 87 Phoenicians, 34, 39 Phosphorus, 21 Photo-micrography, 12 Photography: 126; early experiments in, 258; development of, 259; 291, 292 Picric acid, 106 Pigments, 265 Pintsch: production of, gas, 109, 110, 170 Pitch, 106 Plant-growth: artificial light and, 11, 249 _et seq._ Platinum, 85, 128, 129, 262 Plumbago, 113, 130 Plymouth, 166 Poetry, 346 Police, 162 Potash, chlorate of, 22 Priestley, Professor, quoted, 252 Printing, 8 Progress: influence of fire upon, 15 _et seq._ Prometheus, 16, 41 Propylene, 106 Ptolemy II, 163 Quartz: 18, 19; mercury-arcs, 125; uses of, 126; in skin diseases, 278, 279 Radiators, energy, 88 _et seq._ Radium, 150 Railway Signal Association, 205 Railways: light-signaling applied to, 205 Ramie fiber, 101 Rane, 250, 251 Rare-earth oxides: 85; properties of, 88, 99 Recreation, 9 Redruth, 63 Reformation: ceremonial uses of light during the, 48, 49 Rheumatism, 275 Robins, Benjamin, 201 Rome, 30, 32, 34, 39, 41, 42, 44 Röntgen, 270, 280. _See also_ X-ray. Royal Society of London: 33, 63, 66, 67, 70, 73; and first gas explosion, 75, 111, 112 Rumford, 167 Rushlights, 28, 33 Russia, 281 Ryan, W. D'A., 306 Safety: artificial light in relation to, 14, 225 _et seq._ Salts: chemical, 88, 89; metallic, 120; silver, 257, 258 Sandy Hook Light, 165, 166 San Francisco, 304, 306-309 Savages, 3, 15, 17 Sawyer, 129 Scheele, K. W., 133; quoted, 257, 258 Schools, 9 Science: light and, 6, 7; 97; systematized, 268 Scotland: 26, 31, 32, 48; oil industry in, 56 Scott, Sir Walter, cited, 27, 98 Sculpture: artificial light in relation to, 184 Search-lights, 11, 169 Section of Plant Protection, 225, 226 Selenium, 267, 293 Semaphore, 199 Shells: illuminating, 179 _et seq._ Shirley, Thomas: quoted on natural gas, 66, 67 Siemens, 78 Signaling, 194-207 Silicon: filament, 140 Silk: artificial, 101; carbon-filaments, 129 Simpson, R. E., 227, 231 Silver, 258, 293 Skin diseases: treatment of, 278, 279, 280 Skylights, 13 Sleep, 8 Smallpox, 274, 275 Smeaton, 166 Soho, 69, 72 South Africa, 129 Sparks: 33, 125 Spectrum: visible, 86; Newton quoted on, 87; of elements, 89; of gases, 90; 120, 121; mercury, 124-126 Sperm, 31, 51, 52, 167 Spermaceti, 35, 51 Splinter-holders, 27, 28 Stage: and artificial light, 319 _et seq._; 343 Staite, 117, 118 Stearine, 35, 52 Stearn, 129 Steel, 18, 33 Steinmetz, Hayden and, 253 Sterilization: quartz-mercury-arc and, 280, 281, 282 Stevenson, Robert Louis, quoted, 177 Stores, 13 St. Paul, 43 St. Paul's Cathedral, 300 Street-lighting: development of, 152-162 Sugar, 22 Sulphide of iron, 18 Sulphur, 18, 21, 179, 180, 294 Sulphuric acid, 21, 22 Sun, 8, 16, 19, 20 Swan, 129 Syracuse, 19 Syria, 153 Tallow, 34, 35, 51, 52 Tantalum: 132; filament lamps, 133 Tar, 68, 106 Telegraphy, 195 Telephony, 194 Textiles, 256 Thames, 169 Theaters, 9, 319 _et seq._ Thoria, 85 Tin, 262 Tinder-boxes, 18, 19, 22 Travelers Insurance Company, 227 Trees, 26 Troy, 42 Tuberculosis, 273 Tungsten lamp, 161 _et seq._, 187, 261, 290, 303 Typhus, 273 Ultra-violet rays: 126, 150; in photographic electricity, 267, 268; 270, 272, 294 United States: petroleum in, 57; gas-consumption in, 99; 164, 165, 166 United States Geological Survey, cited on sale of gas, 222 United States Military Intelligence, 225, 226 Vacuum tubes, 81, 286 Venetians, 195 Ventilation, 13 Verne, Jules, 143 Vestal Virgins, 42 Volcanoes, 166 Volta, 111, 112, 127 Voltaic pile: construction of, 111, 127 Von Bolton. _See_ Bolton. War: and artificial light, 11, 178-193 Washington, 305 Water: sterilization of, by artificial light, 280 _et seq._ Watson, Dr. Richard, 67, 68 Watt, 94 Waves: electro-magnetic, 68, 86, 125 _et seq._ Wax, 34, 46, 51 Way: mercury-arc produced by, 124 Wells, 61 Wells, H. G., cited, 148 Welsbach, Auer von: 61; invention of mantle by, 99, 100, 133 Wenham, 78 West Indies, 25 Whale-oil, 31 Wicks, 35, 36, 53, 54, 58, 59 Winsor, 72, 73. _See also_ Winzler. Winzler. _See_ Winsor. _Wolfram._ _See_ Tungsten. Wood, 26, 27, 28 Woolworth Building, 302, 303 Wounds: treatment of, by artificial light, 10 X-ray: production of, tubes during War, 131; 137, 150, 270, 280 Young, James: discovers petroleum, 56 Yttria, 85 _Zeitung_, Cologne: 157; extract from, on street-lighting, 158 Zinc, 125, 130, 267 Zirconia, 84, 85 Transcriber's List of Corrections LOCATION ORIGINAL CORRECTED Chapter II and similiar material and similar material Chapter XIII as a constant level at a constant level Chapter XIV the carbons to distintegrate the carbons to disintegrate Chapter XV John Pechham John Peckham coated with an allow coated with an alloy with various billiant with various brilliant key in depressed key is depressed Chapter XVI has nearly doubled have nearly doubled Chapter XVII this own indifference their own indifference Chapter XXIII Nature's lighting varied Nature's lighting varies Chapter XXIV so-called cadelabra so-called candelabra possibilties possibilities READING REFERENCES ...Applications an Théatre." ...Applications au Théatre." INDEX Photo-micography Photo-micrography Siemans Siemens 
48722	----	available at The Internet Archive. Transcriber Note Text emphasis denoted as _Italic_. U. S. DEPARTMENT OF AGRICULTURE FARMERS' BULLETIN No. 1438 MAKING FERMENTED PICKLES INFORMATION AND DIRECTIONS for pickling vegetables in brine have been prepared for the use of housewives and producers of pickles, and to meet the needs of extension workers. Cucumber (salt, sour, sweet, dill, and mixed) pickles and sauerkraut are given most attention. String beans, green tomatoes, chayotes, mango melons, burr gherkins, cauliflower, corn on the cob, and some fruits, such as peaches and pears, are mentioned. Although intended mainly for guidance in putting up pickles on a small scale in the home, this bulletin may be used also in preparing large quantities on a commercial or semicommercial scale. This bulletin is a revision of, and supersedes, Farmers' Bulletin 1159. Washington, D. C. Issued August, 1924 MAKING FERMENTED PICKLES By Edwin LeFevre, _Scientific Assistant, Microbiological Laboratory, Bureau of Chemistry_ CONTENTS Page How brining preserves vegetables 1 Equipment for brining and pickling 2 Supplies for brining and pickling 4 Cucumber pickles 5 Salt pickles 5 Sour pickles 7 Sweet pickles 8 Dill pickles 8 Mixed pickles 10 Sauerkraut 10 Fermentation and salting of vegetables other than, cucumbers and cabbage 11 Causes of failure 12 Coloring and hardening agents 14 Tables and tests 14 ALTHOUGH excellent pickles can be bought on the market at all seasons of the year, many housewives prefer to make their own, particularly when their home gardens afford a plentiful supply of cucumbers. Brining is a good way to save surplus cucumbers that can not be used or readily sold in the fresh state. Instead of letting them go to waste it is very easy to cure them, after which they may be held as long as desired or until they can be sold to advantage, either in local markets or to pickle manufacturers. Thus growers are protected against loss by overproduction or from inability to speedily market a perishable crop, and the pickle market receives the benefit of a steady supply. HOW BRINING PRESERVES VEGETABLES When vegetables are placed in brine the juices and soluble material contained in them are drawn out by the force known as osmosis. The fermentable sugar present in all fruits and vegetables, which is one of the soluble substances extracted by osmotic action, serves as food for the lactic-acid bacteria which break it down into lactic acid and certain volatile acids. In some vegetables, like cucumbers and cabbage, where the supply of sugar is ample and other conditions are favorable to the growth of the lactic bacteria, a decided acid formation takes place, constituting a distinct fermentation. The acid brine thus formed acts upon the vegetable tissues, bringing about the changes in color, taste, and texture which mark the pickled state. As a rule, a solution of salt is used, although some vegetables quickly give up enough moisture to convert dry salt into brine. Salt also hardens or makes firm the vegetables placed in brine and checks the action of organisms which might otherwise destroy the plant tissues. Cabbage is well preserved in its own brine in the form of sauerkraut. Other vegetables and some fruits may, under certain conditions, be economically preserved by brining. As a rule, however, canning is preferable for these products, because food values and natural flavors are better preserved by that method. Lack of time, a shortage of cans, or an oversupply of raw material may justify the preservation of vegetables other than cucumbers and cabbage by curing in brine. EQUIPMENT FOR BRINING AND PICKLING Stone jars are the most convenient and desirable receptacles (fig. 1) for making small quantities of pickles. Stoneware is much more easily kept clean and absorbs objectionable odors and flavors to a smaller extent than wood. Straight-side, open-top jars, which come in practically all sizes, from 1 to 20 gallons, are best for this purpose. Those used for the directions given in this bulletin are 4-gallon jars which hold about 12 pounds (one-fourth bushel) of cucumbers. If only very small quantities of pickles are put up, wide-mouth bottles or glass jars will do. [Illustration: Fig. 1.--Some suitable containers for home-brined products] Water-tight kegs or barrels are best for making larger quantities of pickles. Those used for the directions given in this bulletin are barrels holding from 40 to 45 gallons. They must first be washed, or possibly charred, to remove all undesirable odors and flavors. Undesirable flavors may be removed by using solutions of potash or soda lye. A strong solution of lye should remain in the barrel for several clays, after which the barrel should be thoroughly soaked and washed with hot water until the lye is removed. Boards about an inch thick make the best covers. These may be of any kind of wood, except yellow or pitch pine, which would give the pickles an undesirable flavor. They should be from 1 to 2 inches less in diameter than the inside of the jar or barrel, so that they may be easily removed. Dipping the covers in paraffin and then burning them over with a flame fills the pores of the wood, thus making it comparatively easy to keep them clean. Heavy plates of suitable size may be used instead of boards as covers for small containers. A clean white cloth is often needed to cover the material in the jar or barrel. Two or three thicknesses of cheesecloth or muslin, cut in circular form, and about 6 inches larger in diameter than the inside of the receptacle, makes a suitable covering. Sometimes grape, beet, or cabbage leaves are used for this purpose. Grape leaves are a good covering for dill pickles, and cabbage leaves for sauerkraut. In addition to the jars, crocks, or kegs in which the pickles are made, 2-quart glass jars are needed for packing the finished product. If corks are used for sealing such containers, they should first be dipped in hot paraffin. When vegetables which have been fermented in a weak brine are to be kept for any length of time, air must be excluded from them. This may be done by sealing the containers with paraffin, beeswax, or oil. Paraffin, the cheapest and probably the best of these three substances, is easily handled and readily separated from the pickles when they are removed from the containers. To remove any dirt, the paraffin should be heated and strained through several thicknesses of cheesecloth. Thus the paraffin may be used over and over again. The clean paraffin is melted and poured over the surface of the pickles in quantities sufficient to make, when hardened, a solid coating about half an inch thick. Where there are vermin, lids should be placed over the paraffin in jars and other covers should be placed over the paraffin in kegs. If applied before active fermentation has stopped, the seal may be broken by the formation of gas below the layer, making it necessary to remove the paraffin, heat it again, and once more pour it over the surface. In many cases a safer and better plan for preserving vegetables fermented in a weak brine is to transfer the pickled product to glass jars as soon as fermentation is completed and seal tightly. Almost anything which furnishes the required pressure will serve as a weight to hold the mass down in a jar or keg. Clean stones (except limestone) and bricks are recommended. [Illustration: Fig. 2.--Salinometer] A pair of kitchen scales and suitable vessels for determining liquid measure are, of course, essential. The salinometer, an instrument for measuring the salt strength of a brine, is very useful, although not absolutely necessary, in brining (fig. 2). By following the directions given here it will be possible to make brines of the required strength without the use of this instrument. Results may be readily checked, however, and any changes in brine strength which occur from time to time may be detected by the use of the salinometer. The salinometer scale is graduated into 100 degrees, which indicate the range of salt concentration between 0°, the reading for pure water at 60° F,; and 100°, which indicates a saturated salt solution (26½ per cent). Table 1 (page 14) shows the relation between salinometer readings and salt percentages. Salinometers are sold for about $1 each by firms dealing in chemical apparatus and supplies. A sugar hydrometer is very useful in all canning and pickling work. Either the Brix or Balling scale may be used. Both read directly in percentages of sugar in a pure sugar solution. A Balling hydrometer, graduated from 0° to 70°, is a convenient instrument for the tests indicated in this bulletin. SUPPLIES FOR BRINING AND PICKLING SALT Fine table salt is not necessary. What is known as common fine salt, or even coarser grades, may be used. Caked or lumpy salt can not be equally distributed. Salt to which anything has been added to prevent caking is not recommended for pickling and brining. Alkaline impurities in the salt are especially objectionable. Any noncaking salt which contains less than 1 per cent of the carbonates or bicarbonates of sodium, calcium, or magnesium may be used for this purpose. VINEGAR A good, clear vinegar of 40 to 60 grain strength (4 to 6 per cent acetic acid) is required in making sour, sweet, and mixed pickles, and is sometimes used for dill pickles. Many pickle manufacturers prefer distilled vinegar, as it is colorless and free from sediment. If fruit vinegars are used they should first be filtered to remove all sediment. SUGAR Granulated sugar should be used in making sweet pickles. The quantity of sugar required for each gallon of vinegar in making sweet liquors is shown in Table 3 (p. 15). SPICES Spices are used to some extent in making nearly all kinds of pickles, but chiefly for sweet, mixed, and dill pickles. Various combinations are used, depending on the kind of pickles to be made and the flavor desired. Peppers (black and cayenne), cloves, cinnamon, celery seed, caraway, dill herb, mustard (yellow), allspice, cardamom, bay leaves, coriander, turmeric, and mace, are the principal whole spices for this purpose. Ginger and horse-radish root are used sometimes. All of these spices may be purchased in bulk and mixed as desired. Mixed whole spices, specially prepared for pickling purposes, sold in the stores, are, as a rule, satisfactory. Care should be taken to see that they are of proper strength. Oil spices may be desirable under some circumstances, but their effect is not so lasting as that of the whole spices. Turmeric has been much used in both the commercial and household preparation of pickles. While some of its qualities entitle it to be classed among the spices, it does not rank in importance as such with the others named. It is employed largely because of its supposed effect on the color of pickles, which is probably overestimated. Dill herb is practically always used with cucumbers when they are fermented in a weak brine and often with other vegetables fermented in this way. It gives the pickle a distinct flavor which is very popular. The dill herb, a native of southern Europe, can be grown in nearly all parts of the United States and usually is obtainable in the markets of the larger cities. While the entire stalk of the dill herb is of value for flavoring, the seeds are best suited for imparting the desired flavor. For this reason the crop should be harvested only after the seeds have become fully mature but are not so ripe that they fall off. The herb may be used green, dried, or brined. When green or brined dill is used, twice as much by weight as would be required if the dried herb were used is taken. Dill retains its flavor for a long time when brined. To preserve it in this way it should be packed in a 60° brine, or in an 80° brine if it is to be kept for a long time. Dill brine is as good as the herb for flavoring. CUCUMBER PICKLES Because of their shape, firmness, or keeping quality some varieties of cucumbers are better adapted for making pickles than others. Among the best of the pickling varieties are the Chicago Pickling, Boston Pickling, and Snow's Perfection. Cucumbers of practically all varieties, sizes, and shapes, however, make good pickles.[1] [1] Information on the cultivation of cucumbers, and the diseases and enemies which attack them, may be obtained from the United States Department of Agriculture. Cucumbers to be pickled should retain from one-eighth to one-fourth inch of their stems, and they should not be bruised. If dirty they should be washed before brining. They should be placed in brine not later than 24 hours after they have been gathered. Cucumbers contain approximately 90 per cent of water. As this large water content reduces materially the salt concentration of any brine in which they are fermented, it is necessary to add an excess of salt at the beginning of a fermentation in the proportion of 1 pound for every 10 pounds of cucumbers. The active stage of cucumber fermentation continues for 10 to 30 days, depending largely on the temperature at which it is conducted. The most favorable temperature is 86° F. Practically all the sugar withdrawn from the cucumbers is utilized during the stage of active fermentation, at the end of which the brine reaches its highest degree of acidity. During this period the salt concentration should not be materially increased: for, although the lactic bacteria are fairly tolerant of salt, there is a limit to their tolerance. The addition of a large quantity of salt at this time would reduce their acid-forming power just when this is essential to a successful fermentation. Salt, therefore, should be added gradually over a period of weeks. SALT PICKLES Salt pickles, or salt stock, are made by curing cucumbers in a brine which should contain not less than 9.5 per cent of salt (approximately 36° on the salinometer scale) at the start. Not only must the brine be kept at this strength, but salt should be added until it has a concentration of about 15 per cent (60° on the salinometer scale). If well covered with a brine of this strength, the surface of which is kept clean, pickles will keep indefinitely. Proper curing of cucumbers requires from six weeks to two months, or possibly longer, according to the temperature at which the process is carried out and the size and variety of the cucumbers. Attempts to use short cuts or to make pickles overnight, as is sometimes advised, are based on a mistaken idea of what really constitutes a pickle. Curing of cucumbers is marked by an increased firmness, a greater degree of translucency, and a change in color from pale green to dark or olive green. These changes are uniform throughout the perfectly cured specimen. So long as any portion of a pickle is whitish or opaque it is not perfectly cured. After proper processing in water, salt pickles may be eaten as such or they may be converted into sour pickles (p. 7), sweet pickles (p. 8), or mixed pickles (p. 10). SMALL QUANTITIES Pack the cucumbers in a 4-gallon jar and cover with 6 quarts of a 10 per cent brine (40° on salinometer scale). At the time of making up the brine, or not later than the following day, add more salt at the rate of 1 pound for every 10 pounds of cucumbers used--in this case 1 pound and 3 ounces. This is necessary to maintain the strength of the brine. Cover with a round board or plate that will go inside the jar, and on top of this place a weight heavy enough to keep the cucumbers well below the surface of the brine. At the end of the first week, and at the end of each succeeding week for five weeks, add one-fourth pound of salt. In adding salt always place it on the cover. If it is added directly to the brine, it may sink, as a result of which the salt solution at the bottom will be very strong, while that near the surface may be so weak that the pickles will spoil. A scum, made up usually of wild yeasts and molds, forms on the surface. As this may prove injurious by destroying the acidity of the brine, remove it by skimming. LARGE QUANTITIES Put into a barrel 5 to 6 inches of a 40° brine (Table 1, p. 14) and add 1 quart of good vinegar. In this brine place the cucumbers as they are gathered. Weigh the cucumbers each time before they are added. Put a loose-fitting wooden cover over the cucumbers and weight it down with a stone heavy enough to bring the brine over the cover. After the cover and stone have been replaced add to the brine over the cover 1 pound of salt for every 10 pounds of cucumbers. Unless the cucumbers are added too rapidly, it will be unnecessary to add more brine, for when a sufficient weight is maintained on the cover the cucumbers make their own brine. If, however, the cucumbers are added rapidly, or if the barrel is filled at once, more brine may be required. In such a case, add enough of the 40° brine to cover the cucumbers. When the barrel is full, add 3 pounds of salt each week for five weeks (15 pounds to a 45-gallon barrel). In adding the salt, place it on the cover. Added in this way it goes into solution slowly, insuring a brine of uniform strength throughout and a gradually increasing salt concentration. Thus, shriveling of the pickles is prevented to a great extent and the growth and activity of the lactic bacteria are not seriously checked. Stirring or agitation of the brine may be harmful for the reason that the introduction of air bubbles is conducive to the growth of spoilage bacteria. From time to time remove the scum which forms on the surface. Where cucumbers are grown extensively for the production of pickles, curing is done in large tanks at salting stations. While it involves certain details of procedure not required in barrel quantities, this method of curing is essentially the same. PROCESSING After being cured in brine, pickles must receive a processing in water to remove the excess of salt. If they are to be used as salt pickles, only a partial processing is required. If, however, they are to be made into sour, sweet, or mixed pickles, the salt should be largely, but not completely, removed. Pickles keep better when the salt is not entirely soaked out. Under factory conditions, processing is accomplished by placing the pickles in tanks, which are then filled with water and subjected to a current of steam, the pickles being agitated meanwhile. In most homes, however, the equipment for such treatment is not available. The best that can be done in the home is to place the pickles in a suitable vessel, cover them with water, and heat them slowly to about 120° F., at which temperature they should be held for from 10 to 12 hours, being stirred frequently. The water is then poured off, and the process is repeated, if necessary, until the pickles have only a slightly salty taste. SORTING After processing, the pickles should be sorted. To secure the most attractive product, pickles should be as nearly as possible of uniform size. At least three sizes are recognized--small (2 to 3 inches long) , medium (3 to 4 inches long), and large (4 inches or longer). Only the small sizes are selected for bottling. Fairly small and medium-large cucumbers are well adapted to the making of sweet pickles. The larger sizes may be used for sour and dill pickles. Imperfectly formed pickles, the so-called crooks and nubs, can be cut up and added to mixed pickles or other combinations of which cucumbers form a part. The number of pickles of various sizes required to make a gallon is shown in Table 4, page 16. SOUR PICKLES After pickles have been processed sufficiently, drain them well and cover them at once with vinegar. A 45 or 50 grain vinegar usually gives all the sourness that is desirable. If, however, very sour pickles are preferred, it would be well to use at first a 45-grain vinegar, and after a week or 10 days transfer the pickles to a vinegar of the strength desired. As the first vinegar used will in all cases be greatly reduced in strength by dilution with the brine contained in the pickles, it will be necessary to renew the vinegar after a few weeks. If this is not done and the pickles are held for any length of time they may spoil. The best containers for sour pickles are stone jars, or, for large quantities, kegs or barrels. Covered with a vinegar of the proper strength, pickles should keep indefinitely. SWEET PICKLES Cover the cured and processed cucumbers with a sweet liquor made by dissolving sugar in vinegar, usually with the addition of spices. Depending upon the degree of sweetness desired, the quantity of sugar may vary from 4 to 10 pounds to the gallon of vinegar, 6 pounds to the gallon usually giving satisfactory results. The chief difficulty in making sweet pickles is their tendency to become shriveled and tough, which increases with the sugar concentration of the liquor. This danger can usually be avoided by covering the pickles first with a plain 45 to 50 grain vinegar. After one week discard this vinegar, which in all probability has become greatly reduced in strength, and cover with a liquor made by adding 4 pounds of sugar to the gallon of vinegar. It is very important that the acidity of the liquor used on pickles be kept as high as possible. A decrease in acidity much below a 30-grain strength may permit the growth of yeasts, with resulting fermentation and spoilage. If a liquor containing more than 4 pounds of sugar to the gallon is desired, it would be best not to .exceed that quantity at first, but gradually add sugar until the desired concentration is obtained. A sugar hydrometer readily and accurately indicates the sugar concentration (p. 4). A reading of 42° (Brix or Balling) would indicate a concentration of approximately 6 pounds of sugar to the gallon of vinegar. (Table 3, p. 15.) Spices are practically always added in making sweet pickles. The effect of too much spice, especially the stronger kinds, like peppers and cloves, however, is injurious. One ounce of whole mixed spices to 4 gallons of pickles is enough. As spices may cause cloudiness of the vinegar, they should be removed after the desired flavor has been obtained. Heating is an aid to a better utilization of the spice. Add the required quantity of spice, in a cheesecloth bag, to the vinegar and hold at the boiling point for not longer than half an hour. Heating too long causes the vinegar to darken. If considered desirable, add sugar at this time, and pour at once over the pickles. If the pickles are to be packed in bottles or jars, after such preliminary treatment as may be required, transfer them to these containers and cover them with a liquor made as desired. DILL PICKLES The method for making dill pickles differs from that for making salt pickles in two important particulars. A much weaker brine is used, and spices, chiefly dill, are added. Because of the weaker salt concentration, a much more rapid curing takes place. As a result they can be made ready for use in about half the time required for ordinary brined pickles. This shortening of the period of preparation, however, is gained at the expense of the keeping quality of the product. For this reason it is necessary to resort to measures which will prevent spoilage. SMALL QUANTITIES Place in the bottom of the jar a layer of dill and one-half ounce of mixed spice. Then fill the jar, to within 2 or 3 inches of the top, with washed cucumbers of as nearly the same size as practicable. Add another half ounce of spice and layer of dill. It is a good plan to place over the top a layer of grape leaves. In fact, it would be well to place these at both the bottom and top. They make a very suitable covering and have a greening effect on the pickles. Pour over the pickles a brine made as follows: Salt, 1 pound; vinegar, 1 pint ; water, 2 gallons. Never use a hot brine at the beginning of a fermentation. The chances are that it would kill the organisms present, thus preventing fermentation. Cover with a board cover or plate with sufficient weight on top to hold the cucumbers well below the brine. If the cucumbers are packed at a temperature around 86° F., an active fermentation will at once set in. This should be completed in 10 days to 2 weeks, if a temperature of about 86° F. is maintained. The scum which soon forms on the surface and which consists usually of wild yeasts, but often contains molds and bacteria, should be skimmed off. After active fermentation has stopped, it is necessary to protect the pickles against spoilage. This may be done in one of two ways: (1) Cover with a layer of paraffin. This should be poured while hot over the surface of the brine or as much of it as is exposed around the edges of the board cover. When cooled this forms a solid coating which effectually seals the pickles. (2) Seal the pickles in glass jars or cans. As soon as they are sufficiently cured, which may be determined by their agreeable flavor and dark-green color, transfer them to glass jars, and fill either with their own brine or with a fresh brine made as directed. Add a small quantity of dill and spice. Bring the brine to a boil, and, after cooling to about 160° F., pour it over the pickles, filling the jars full. Seal the jars tight. The plan of preserving dill pickles by sealing in jars has the merit of permitting the use of a small quantity without the necessity of opening and resealing a large bulk, as is the case when pickles are packed in large containers and sealed with paraffin. LARGE QUANTITIES Fill a barrel with cucumbers. Add 6 to 8 pounds of green or brined dill, or half that quantity of dry dill, and 1 quart of mixed spices. If brined dill is used, it is well to add about 2 quarts of the dill brine. The dill and spices should be evenly distributed at the bottom, middle, and top of the barrel. Also add 1 gallon of good vinegar.[2] [2] This addition of vinegar is not essential, and many prefer not to use it. In the proportion indicated, however, it is favorable to the growth of the lactic bacteria and helps to prevent the growth of spoilage organisms. Its use, therefore, is to be regarded with favor. Some prefer to omit the mixed spices for the reason that they interfere with the distinctive flavor of the dill herb. Head up tight and, through a hole bored in the head, fill the barrel with a brine made in the proportion of one-half pound of salt to a gallon of water. Add brine until it flows over the head and is level with the top of the chime. Maintain this level by adding brine from time to time. Remove the scum which soon forms on the surface. During the period of active fermentation, keep the barrel in a warm place and leave the hole in the head open to allow gas to escape. When active fermentation is over, as indicated by the cessation of bubbling and frothing on the surface, the barrel may be plugged tight and placed in storage, preferably in a cool place. Leakage and other conditions may cause the brine in a barrel of pickles to recede at any time. The barrels should be inspected occasionally, and more brine added if necessary. Pickles put up in this way should be ready for use within about six weeks. When pickles are to be held in storage a long time, a 28° brine, made by adding 10 ounces of salt to a gallon of water, should be used. Pickles packed in a brine of this strength will keep a year, if the barrels are kept filled and in a cool place. The important factor in preserving pickles put up in a weak brine, such as is ordinarily used for dill pickles, is the exclusion of air. When put up in tight barrels this is accomplished by keeping the barrels entirely filled with brine. MIXED PICKLES Onions, cauliflower, green peppers, tomatoes, and beans, as well as cucumbers, are used for making mixed pickles. All vegetables should first be cured in brine. For making mixed pickles, very small vegetables are much to be preferred. If larger ones must be used, first cut them into pieces of a desirable and uniform shape and size. Place in the bottom of each wide-mouth bottle or jar a little mixed spice. In filling the bottle arrange the various kinds of pickles in as neat and orderly a manner as possible. The appearance of the finished product depends largely upon the manner in which they are packed in the bottle. Do not completely fill the bottles. If sour pickles are desired, fill the bottles completely with a 45-grain vinegar. If sweet ones are wanted, fill with a liquor made by dissolving 4 to 6 pounds of sugar in a gallon of vinegar. Seal tight, and label properly. SAUERKRAUT For making sauerkraut in the home, 4 or 6 gallon stone jars are considered the best containers, unless large quantities are desired, in which case kegs or barrels may be used. Select only mature, sound heads of cabbage. After removing all decayed or dirty leaves, quarter the heads and slice off the core portion. For shredding, one of the hand-shredding machines which can be obtained on the market is much the best, although an ordinary slaw cutter or a large knife will do. In making sauerkraut the fermentation is carried out in a brine made from the juice of the cabbage which is drawn out by the salt. One pound of salt for every 40 pounds of cabbage makes the proper strength of brine to produce the best results. The salt may be distributed as the cabbage is packed in the jar or it may be mixed with the shredded cabbage before being packed. The distribution of 2 ounces of salt with every 5 pounds of cabbage probably is the best way to get an even distribution. Pack the cabbage firmly, but not too tightly, in the jar or keg. When full, cover with a clean cloth and a board or plate. On the cover place a weight heavy enough to cause the brine to come up to the cover. If the jar is kept at a temperature of about 86° F., fermentation will start promptly. A scum soon forms on the surface of the brine. As this scum tends to destroy the acidity and may affect the cabbage, it should be skimmed off from time to time. If kept at 86° F., the fermentation should be completed in six to eight days. A well-fermented sauerkraut should show a normal acidity of approximately +20, or a lactic acid percentage of 1.8 (p. 16). After fermentation is complete, set the sauerkraut in a cool place. If the cabbage is fermented late in the fall, or if it can be stored in a very cool place, it may not be necessary to do more than keep the surface skimmed and protected from insects, etc.; otherwise it will be necessary to resort to one of the following measures to prevent spoilage: (1) Pour a layer of hot paraffin over the surface, or as much of it as is exposed around the cover. Properly applied to a clean surface, this effectually seals the jar and protects the contents from contamination. (2) After the fermentation is complete, pack the sauerkraut in glass jars, adding enough of the "kraut" brine, or a weak brine made by adding an ounce of salt to a quart of water, to completely fill the jars. Seal the jars tight, and set them away in a cool place. The second method is much to be p referred to the first. Sauerkraut properly fermented and stored in this way has kept throughout a season in good condition. Placing the jars before sealing in a water bath and heating until the center of the jar shows a temperature of about 160° F. gives an additional assurance of good-keeping quality of the "kraut." In the commercial canning of sauerkraut, where conditions and length of storage can not be controlled, heat must always be used. FERMENTATION AND SALTING OF VEGETABLES OTHER THAN CUCUMBERS AND CABBAGE There are three methods of preserving vegetables by the use of salt: FERMENTATION IN AN ADDED BRINE Experiments have shown that string beans, green tomatoes, beets, chayotes, mango melons, burr gherkins, cauliflower, and corn (on cob) may be well preserved in a 10 per cent brine (40° on the salinometer scale) for several months. Peppers and onions are better preserved in an 80° brine. The brine must be maintained at its original strength by the addition of salt, and the surface of the brine must be kept free from scum. Some of the vegetables listed, notably string beans and green tomatoes, are well adapted to fermentation in a weak brine (5 per cent salt), in which case dill and other spices may be added. The general directions given for dill pickles (p. 8) should be followed. FERMENTATION IN BRINE PRODUCED BY DRY SALTING This method, of course, can be used only for vegetables which contain enough water to make their own brine. String beans, if young and tender, may be preserved in this way. Remove tips and strings, and, if the pods are large, break them in two. Older beans, and doubtless other vegetables, could be preserved by this method if first shredded in the same manner as cabbage (p. 10). Use salt equal to 3 per cent of the weight of the vegetables (1 ounce salt to about 2 pounds vegetables). SALTING WITHOUT FERMENTATION Enough salt to prevent all bacterial action must be added. Wash and weigh the vegetables. Mix with them thoroughly one-fourth their weight of salt. If after the addition of pressure there is not enough brine to cover the product, add brine made by dissolving 1 pound of salt in 2 quarts of water. As soon as bubbling ceases, protect the surface by covering with paraffin. This method is especially well adapted to vegetables in which the sugar content is too low to produce a successful fermentation, such as chard, spinach, and dandelions. Corn can also be well preserved in this way. Husk it and remove the silk. Cook it in boiling water for 10 minutes, to set the milk. Then cut the corn from the cob with a sharp knife, weigh it, and pack it in layers, with one-fourth its weight of fine salt. The methods of preservation outlined are not limited to vegetables. Solid fruits, like clingstone peaches and Kieffer pears, can be preserved in an 80° brine for as long as six months. After the salt has been soaked out, they may be worked up into desirable products by the use of spices, vinegar, sugar, etc. Soft fruits, like Elberta peaches and Bartlett pears, are best preserved in weak vinegar (2 per cent acetic acid).[3] [3] Report of an investigation in the Bureau of Chemistry on the utilization of brined products, by Rhea C. Scott, 1919. CAUSES OF FAILURE SOFT OR SLIPPERY PICKLES A soft or slippery condition, one of the most common forms of spoilage in making pickles, is the result of bacterial action. It always occurs when pickles are exposed above the brine and very often when the brine is too weak to prevent the growth of spoilage organisms. To prevent it keep the pickles well below the brine and the brine at the proper strength. To keep pickles for more than a very few weeks a brine should contain 10 per cent of salt. Once pickles have become soft or slippery as a result of bacterial action no treatment will restore them to a normal condition. HOLLOW PICKLES Hollow pickles may occur during the process of curing. This condition, however, does not mean a total loss, for hollow pickles may be utilized in making mixed pickles or certain forms of relish. While there are good reasons to believe that hollow pickles are the result of a faulty development or nutrition of the cucumber, there is also a strong probability that incorrect methods may contribute to their formation. One of these is allowing too long a time to intervene between gathering and brining. This period should not exceed 21 hours. Hollow pickles frequently become floaters. Sound cucumbers properly cured do not float, but any condition which operates to lower their relative weight, such as gaseous distention, may cause them to rise to the surface. EFFECT OF HARD WATER So-called hard waters should not be used in making a brine. The presence of large quantities of calcium salts and possibly other salts found in many natural waters may prevent the proper acid formation, thus interfering with normal curing. The addition of a small quantity of vinegar serves to overcome alkalinity when hard water must be used. If present in any appreciable quantity, iron is objectionable, causing a blackening of the pickles under some conditions. SHRIVELING Shriveling of pickles often occurs when they have been placed at once in very strong salt or sugar solutions, or even in very strong vinegars. For this reason avoid such solutions so far as possible. When a strong solution is desirable the pickles should first be given a preliminary treatment in a weaker solution. This difficulty is most often encountered in making sweet pickles. The presence of sugar in high concentrations is certain to cause shriveling unless EFFECT OF TOO MUCH SALT ON SAUERKRAUT Perhaps the most common cause of failure in making sauerkraut is the use of too much salt. The proper quantity is 2| per cent by weight of the cabbage packed. When cabbage is to be fermented in very warm weather it may be well to use a little more salt. As a rule, however, this should not exceed 3 per cent. In applying the salt see that it is evenly distributed. The red streaks which are sometimes seen in sauerkraut are believed to be due to uneven distribution of salt. EFFECT OF SCUM Spoilage of the top layers of vegetables fermented in brine is sure to occur unless the scum which forms on the surface is frequently removed. This scum is made up of wild yeasts, molds, and bacteria, which, if allowed to remain, attack and break down the vegetables beneath. They may also weaken the acidity of the brine, in which way they may cause spoilage. The fact that the top layers have spoiled, does not necessarily mean, however, that all in the container are spoiled. The molds and other organisms which cause the spoilage do not quickly get down to the lower layers. The part found in good condition often may be saved by carefully removing the spoiled part from the top, adding a little fresh brine, and pouring hot paraffin over the surface. EFFECT OF TEMPERATURE Temperature has an important bearing on the success of a lactic fermentation. The bacteria which are essential in the fermentation of vegetable foods are most active at a temperature of approximately 86° F., and as the temperature falls below this point their activity correspondingly diminishes. It is essential, therefore, that the foods be kept as close as possible to 86° F. at the start and during the active stages of a fermentation. This is especially important in the production of sauerkraut, which is often made in the late fall or winter. The fermentation may be greatly retarded or even stopped by too low a temperature. After the active stages of a fermentation have passed, store the food in a cool place. Low temperatures are always an aid in the preservation of food products. COLORING AND HARDENING AGENTS To make what is thought to be a better looking product, it is the practice in some households to "green" pickles by heating them with vinegar in a copper vessel. Experiments have shown that in this treatment copper acetate is formed, and that the pickles take up very appreciable quantities of it. _Copper acetate is poisonous._ By a ruling of the Secretary of Agriculture, made July 12, 1912, foods greened with copper salts, all of which are poisonous, will be regarded as adulterated. Alum is often used for the purpose presumably of making pickles firm. The use of alum in connection with food products is of doubtful expediency, to say the least. If the right methods are followed in pickling, the salt and acids in the brine will give the desired firmness. The use of alum, or any other hardening agent, is unnecessary. TABLES AND TESTS Table 1.--_Salt percentages, corresponding salinometer readings, and quantity of salt required to make 6 quarts of brine_ -----------+------------+-------------- | | Salt in Salt in |Salinometer | 6 quarts of solution | reading |finished brine -----------+------------+-------------- _Per cent_| _Degrees_ | _Ounces_ 1.06 | 4 | 2 2.12 | 8 | 4¼ 3.18 | 12 | 6½ 4.24 | 16 | 8½ 5.3 | 20 | 11 7.42 | 28 | 14½ 8.48 | 32 | 18 9.54 | 36 | 20 10.6 | 40 | 22½ 15.9 | 60 | 35 21.2 | 80 | 48 26.5 | 100 | 64 -----------+------------+-------------- The figures given in the first two columns of Table 1 are correct. Those in the last column are correct within the possibilities of ordinary household methods. To make up a brine from this table, the required quantity of salt is dissolved in a smaller volume of water and water is added to make up as nearly as possible to the required 6 quarts. One pound of salt dissolved in 9 pints of water makes a solution with a salinometer reading of 40°, or approximately a 10 per cent brine. In a brine of this strength, fermentation proceeds somewhat slowly. Pickles kept in a brine maintained at this strength will not spoil. One-half pound of salt dissolved in 9 pints of water makes approximately a 5 per cent brine, with a salinometer reading of 20°. A brine of this strength permits a rapid fermentation, but vegetables kept in such a brine will spoil within a few weeks if air is not excluded. A brine in which a fresh egg just floats is approximately a 10 per cent solution. Fermentation takes place fairly well in brines of 40° strength, and will, to some extent at least, up to 60°. At 80° all fermentation stops. The volume of brine necessary to cover vegetables is about half the volume of the material to be fermented. For example, if a 5-gallon keg is to be packed, 2½ gallons of brine is required. Table 2.--_Freezing point of brine at different salt concentrations_ ----------+-------------+------------ Salt | Salinometer | Freezing | reading | temperature ----------+-------------+------------ _Per cent_| _Degrees_ | °_F_ 5 | 20 | 25.2 10 | 40 | 18.7 15 | 60 | 12.2 20 | 80 | 6.1 25 | 100 | 0.5 ----------+-------------+------------ Table 3.--_Density of sugar sirup_ ---------+--------------- | Quantity of | sugar for Density | each gallon | of water[4] ---------+--------------- _Degrees | Brix or | Balling_ | _Lbs._ _Ozs._ 5 | 7 10 | 14.8 15 | 1 7.5 20 | 1 14.75 25 | 2 12.5 30 | 3 9 40 | 5 8.75 45 | 6 13 50 | 8 5.25 55 | 10 4 60 | 12 8 ---------+--------------- [4] When vinegar is used, the equivalent sugar hydrometer reading would be about 2 degrees higher than that indicated in the table. Table 4.--_Number of cucumbers of various sizes required to make a gallon of pickles_ -------------------+----------------+----------- | | Number to Size | Variety | a gallon -------------------+----------------+----------- 1 to 2 inches long | Gherkins[5] | 250 to 650 2 to 3 inches long | Small pickles | 130 to 250 3 to 4 inches long | Medium pickles | 40 to 130 4 inches and longer| Large pickles | 12 to 40 -------------------+----------------+----------- [5] Small pickles are usually designated as gherkins. Those of very small size are sometimes called midgets. The maximum acidity formed by a lactic fermentation of vegetables in brine varies from 0.25 to 2 per cent. The maximum is reached at or soon after the close of the active stage of fermentation. After this the acidity usually decreases slowly. The stage of active fermentation continues for from one to three weeks, depending upon the temperature, strength of brine, etc. During this period gas is formed and froth appears on the surface, owing to the rising of gas bubbles. At the close of this period the brine becomes "still." The quantity of acid formed depends primarily upon the sugar content of the vegetables fermented, but it may be influenced by other factors. Dipping a piece of blue litmus paper (obtainable at drug stores) in the brine will show whether the brine is acid. If the paper turns pinkish or red, the brine is acid, but the litmus paper does not give a definite indication of the degree of acidity. For those who want to know accurately what the degree of acidity is the following method is outlined: With a pipette transfer exactly 5 cubic centimeters of the brine to a small evaporating dish. To this add 45 cubic centimeters of distilled water and 1 cubic centimeter of a 0.5 per cent solution of phenolphthalein in 50 per cent alcohol. Then run in slowly a one-twentieth normal sodium hydrate solution. This is best done by using a 25 cubic centimeter burette, graduated in tenths. As the sodium hydrate is being added stir constantly, and note carefully when the entire liquid shows a faint pink tint. This indicates that the neutral point has been reached. Read off carefully the exact quantity of sodium hydrate required to neutralize the mixture in the dish. This number multiplied by 0.09 gives the number of grams of acid per 100 cubic centimeters, calculated as lactic, present in the brine. This method can be used to determine the acid strength of vinegars. Multiply by 0.06 to ascertain the number of grams of acetic acid per 100 cubic centimeters present in the vinegar. The apparatus and chemicals needed for this test can be obtained from any firm dealing in chemical apparatus and supplies. ORGANIZATION OF THE UNITED STATES DEPARTMENT OF AGRICULTURE _Secretary of Agriculture_ Henry C. Wallace. _Assistant Secretary_ Howard M. Gore. _Director of Scientific_ Work E. D. Ball. _Director of Regulatory Work_ Walter G. Campbell. _Director of Extension Work_ C. W. Warburton. _Solicitor_ R. W. Williams. _Weather Bureau_ Charles F. Marvin, _Chief_. _Bureau of Agricultural Economics_ Henry C. Taylor, _Chief_. _Bureau of Animal Industry_ John R. Mohler, _Chief_. _Bureau of Plant Industry_ William A. Taylor, _Chief_. _Forest Service_ W. B. Greeley. _Chief_. _Bureau of Chemistry_ C. A. Browne, _Chief_. _Bureau of Soils_ Milton Whitney. _Chief_. _Bureau of Entomology_ L. O. Howard, _Chief_. _Bureau of Biological Surrey_ E. W. Nelson, _Chief_. _Bureau of Public Roads_ Thomas H. MacDonald, _Chief_. _Bureau of Home Economics_ Louise Stanley. _Chief_, _Bureau of Dairying_ C. W. Larson, _Chief_. _Office of Experiment Stations_ E. W. Allen. _Chief_. _Fixed Nitrogen Research Laboratory_ F. G. Cottrell, _Director_. _Publications_ L. J. Haynes, _In Charge_. _Library_ Claribel R. Barnett. _Librarian_. _Federal Horticultural Board_ C. L. Marlatt, _Chairman_. _Insecticide and Fungicide Board_ J. K. Haywood. _Chairman_. _Packers and Stockyards Administration_ } Chester Morrill, _Grain Futures Administration_ } _Assistant to the Secretary_. --------------- This bulletin is a contribution from _Bureau of Chemistry_ C. A. Browne, _Chief_. _Microbiological Laboratory_ Charles Thou, _Mycologist in Charge_. ---------------------------------------- ADDITIONAL COPIES OF THIS PUBLICATION MAY BE PROCURED FROM THE SUPERINTENDENT OF DOCUMENTS GOVERNMENT PRINTING OFFICE WASHINGTON, D. C. AT 5 CENTS PER COPY ---------------------------------------- * * * * * Transcriber Note Figure 1 was moved so that it would not split a paragraph. 
17149	----	Note: Project Gutenberg also has an HTML version of this file which includes the original illustrations. See 17149-h.htm or 17149-h.zip: (http://www.gutenberg.net/dirs/1/7/1/4/17149/17149-h/17149-h.htm) or (http://www.gutenberg.net/dirs/1/7/1/4/17149/17149-h.zip) Transcriber's notes: Underscores before and after words denote italics. Underscore and {} denote subscripts. Footnotes moved to end of book. The book starts using the word "CHAPTER" only after its chapter number XI. I have left it the same in this text. The Century Books of Useful Science CREATIVE CHEMISTRY Descriptive of Recent Achievements in the Chemical Industries by EDWIN E. SLOSSON, M.S., PH.D. Literary Editor of _The Independent_, Associate in Columbia School of Journalism Author of "Great American Universities," "Major Prophets of Today," "Six Major Prophets," "On Acylhalogenamine Derivatives and the Beckmann Rearrangement," "Composition of Wyoming Petroleum," etc. With Many Illustrations [Illustration (Decorative)] New York The Century Co. Copyright, 1919, by The Century Co. Copyright, 1917, 1918, 1919, by The Independent Corporation Published, October, 1919 [Illustration: From "America's Munitions" THE PRODUCTION OF NEW AND STRONGER FORMS OF STEEL IS ONE OF THE GREATEST TRIUMPHS OF MODERN CHEMISTRY The photograph shows the manufacture of a 12-inch gun at the plant of the Midvale Steel Company during the late war. The gun tube, 41 feet long, has just been drawn from the furnace where it was tempered at white heat and is now ready for quenching.] TO MY FIRST TEACHER PROFESSOR E.H.S. BAILEY OF THE UNIVERSITY OF KANSAS AND MY LAST TEACHER PROFESSOR JULIUS STIEGLITZ OF THE UNIVERSITY OF CHICAGO THIS VOLUME IS GRATEFULLY DEDICATED CONTENTS I THREE PERIODS OF PROGRESS 3 II NITROGEN 14 III FEEDING THE SOIL 37 IV COAL-TAR COLORS 60 V SYNTHETIC PERFUMES AND FLAVORS 93 VI CELLULOSE 110 VII SYNTHETIC PLASTICS 128 VIII THE RACE FOR RUBBER 145 IX THE RIVAL SUGARS 164 X WHAT COMES FROM CORN 181 XI SOLIDIFIED SUNSHINE 196 XII FIGHTING WITH FUMES 218 XIII PRODUCTS OF THE ELECTRIC FURNACE 236 XIV METALS, OLD AND NEW 263 READING REFERENCES 297 INDEX 309 A CARD OF THANKS This book originated in a series of articles prepared for _The Independent_ in 1917-18 for the purpose of interesting the general reader in the recent achievements of industrial chemistry and providing supplementary reading for students of chemistry in colleges and high schools. I am indebted to Hamilton Holt, editor of _The Independent_, and to Karl V.S. Howland, its publisher, for stimulus and opportunity to undertake the writing of these pages and for the privilege of reprinting them in this form. In gathering the material for this volume I have received the kindly aid of so many companies and individuals that it is impossible to thank them all but I must at least mention as those to whom I am especially grateful for information, advice and criticism: Thomas H. Norton of the Department of Commerce; Dr. Bernhard C. Hesse; H.S. Bailey of the Department of Agriculture; Professor Julius Stieglitz of the University of Chicago; L.E. Edgar of the Du Pont de Nemours Company; Milton Whitney of the U.S. Bureau of Soils; Dr. H.N. McCoy; K.F. Kellerman of the Bureau of Plant Industry. E.E.S. LIST OF ILLUSTRATIONS The production of new and stronger forms of steel is one of the greatest triumphs of modern chemistry _Frontispiece_ FACING PAGE The hand grenades contain potential chemical energy capable of causing a vast amount of destruction when released 16 Women in a munition plant engaged in the manufacture of tri-nitro-toluol 17 A chemical reaction on a large scale 32 Burning air in a Birkeland-Eyde furnace at the DuPont plant 33 A battery of Birkeland-Eyde furnaces for the fixation of nitrogen at the DuPont plant 33 Fixing nitrogen by calcium carbide 40 A barrow full of potash salts extracted from six tons of green kelp by the government chemists 41 Nature's silent method of nitrogen fixation 41 In order to secure a new supply of potash salts the United States Government set up an experimental plant at Sutherland, California, for utilization of kelp 52 Overhead suction at the San Diego wharf pumping kelp from the barge to the digestion tanks 53 The kelp harvester gathering the seaweed from the Pacific Ocean 53 A battery of Koppers by-product coke-ovens at the plant of the Bethlehem Steel Company, Sparrows Point, Maryland 60 In these mixing vats at the Buffalo Works, aniline dyes are prepared 61 A paper mill in action 120 Cellulose from wood pulp is now made into a large variety of useful articles of which a few examples are here pictured 121 Plantation rubber 160 Forest rubber 160 In making garden hose the rubber is formed into a tube by the machine on the right and coiled on the table to the left 161 The rival sugars 176 Interior of a sugar mill showing the machinery for crushing cane to extract the juice 177 Vacuum pans of the American Sugar Refinery Company 177 Cotton seed oil as it is squeezed from the seed by the presses 200 Cotton seed oil as it comes from the compressors flowing out of the faucets 201 Splitting coconuts on the island of Tahiti 216 The electric current passing through salt water in these cells decomposes the salt into caustic soda and chlorine gas 217 Germans starting a gas attack on the Russian lines 224 Filling the cannisters of gas masks with charcoal made from fruit pits--Long Island City 225 The chlorpicrin plant at the Bdgewood Arsenal 234 Repairing the broken stern post of the _U.S.S. Northern Pacific_, the biggest marine weld in the world 235 Making aloxite in the electric furnaces by fusing coke and bauxite 240 A block of carborundum crystals 241 Making carborundum in the electric furnace 241 Types of gas mask used by America, the Allies and Germany during the war 256 Pumping melted white phosphorus into hand grenades filled with water--Edgewood Arsenal 257 Filling shell with "mustard gas" 257 Photomicrographs showing the structure of steel made by Professor E.G. Mahin of Purdue University 272 The microscopic structure of metals 273 INTRODUCTION BY JULIUS STIEGLITZ Formerly President of the American Chemical Society, Professor of Chemistry in The University of Chicago The recent war as never before in the history of the world brought to the nations of the earth a realization of the vital place which the science of chemistry holds in the development of the resources of a nation. Some of the most picturesque features of this awakening reached the great public through the press. Thus, the adventurous trips of the _Deutschland_ with its cargoes of concentrated aniline dyes, valued at millions of dollars, emphasized as no other incident our former dependence upon Germany for these products of her chemical industries. The public read, too, that her chemists saved Germany from an early disastrous defeat, both in the field of military operations and in the matter of economic supplies: unquestionably, without the tremendous expansion of her plants for the production of nitrates and ammonia from the air by the processes of Haber, Ostwald and others of her great chemists, the war would have ended in 1915, or early in 1916, from exhaustion of Germany's supplies of nitrate explosives, if not indeed from exhaustion of her food supplies as a consequence of the lack of nitrate and ammonia fertilizer for her fields. Inventions of substitutes for cotton, copper, rubber, wool and many other basic needs have been reported. These feats of chemistry, performed under the stress of dire necessity, have, no doubt, excited the wonder and interest of our public. It is far more important at this time, however, when both for war and for peace needs, the resources of our country are strained to the utmost, that the public should awaken to a clear realization of what this science of chemistry really means for mankind, to the realization that its wizardry permeates the whole life of the nation as a vitalizing, protective and constructive agent very much in the same way as our blood, coursing through our veins and arteries, carries the constructive, defensive and life-bringing materials to every organ in the body. If the layman will but understand that chemistry is the fundamental _science of the transformation of matter_, he will readily accept the validity of this sweeping assertion: he will realize, for instance, why exactly the same fundamental laws of the science apply to, and make possible scientific control of, such widely divergent national industries as agriculture and steel manufacturing. It governs the transformation of the salts, minerals and humus of our fields and the components of the air into corn, wheat, cotton and the innumerable other products of the soil; it governs no less the transformation of crude ores into steel and alloys, which, with the cunning born of chemical knowledge, may be given practically any conceivable quality of hardness, elasticity, toughness or strength. And exactly the same thing may be said of the hundreds of national activities that lie between the two extremes of agriculture and steel manufacture! Moreover, the domain of the science of the transformation of matter includes even life itself as its loftiest phase: from our birth to our return to dust the laws of chemistry are the controlling laws of life, health, disease and death, and the ever clearer recognition of this relation is the strongest force that is raising medicine from the uncertain realm of an art to the safer sphere of an exact science. To many scientific minds it has even become evident that those most wonderful facts of life, heredity and character, must find their final explanation in the chemical composition of the components of life producing, germinal protoplasm: mere form and shape are no longer supreme but are relegated to their proper place as the housing only of the living matter which functions chemically. It must be quite obvious now why thoughtful men are insisting that the public should be awakened to a broad realization of the significance of the science of chemistry for its national life. It is a difficult science in its details, because it has found that it can best interpret the visible phenomena of the material world on the basis of the conception of invisible minute material atoms and molecules, each a world in itself, whose properties may be nevertheless accurately deduced by a rigorous logic controlling the highest type of scientific imagination. But a layman is interested in the wonders of great bridges and of monumental buildings without feeling the need of inquiring into the painfully minute and extended calculations of the engineer and architect of the strains and stresses to which every pin and every bar of the great bridge and every bit of stone, every foot of arch in a monumental edifice, will be exposed. So the public may understand and appreciate with the keenest interest the results of chemical effort without the need of instruction in the intricacies of our logic, of our dealings with our minute, invisible particles. The whole nation's welfare demands, indeed, that our public be enlightened in the matter of the relation of chemistry to our national life. Thus, if our commerce and our industries are to survive the terrific competition that must follow the reëstablishment of peace, our public must insist that its representatives in Congress preserve that independence in chemical manufacturing which the war has forced upon us in the matter of dyes, of numberless invaluable remedies to cure and relieve suffering; in the matter, too, of hundreds of chemicals, which our industries need for their successful existence. Unless we are independent in these fields, how easily might an unscrupulous competing nation do us untold harm by the mere device, for instance, of delaying supplies, or by sending inferior materials to this country or by underselling our chemical manufacturers and, after the destruction of our chemical independence, handicapping our industries as they were in the first year or two of the great war! This is not a mere possibility created by the imagination, for our economic history contains instance after instance of the purposeful undermining and destruction of our industries in finer chemicals, dyes and drugs by foreign interests bent on preserving their monopoly. If one recalls that through control, for instance, of dyes by a competing nation, control is in fact also established over products, valued in the hundreds of millions of dollars, in which dyes enter as an essential factor, one may realize indeed the tremendous industrial and commercial power which is controlled by the single lever--chemical dyes. Of even more vital moment is chemistry in the domain of health: the pitiful calls of our hospitals for local anesthetics to alleviate suffering on the operating table, the frantic appeals for the hypnotic that soothes the epileptic and staves off his seizure, the almost furious demands for remedy after remedy, that came in the early years of the war, are still ringing in the hearts of many of us. No wonder that our small army of chemists is grimly determined not to give up the independence in chemistry which war has achieved for us! Only a widely enlightened public, however, can insure the permanence of what farseeing men have started to accomplish in developing the power of chemistry through research in every domain which chemistry touches. The general public should realize that in the support of great chemical research laboratories of universities and technical schools it will be sustaining important centers from which the science which improves products, abolishes waste, establishes new industries and preserves life, may reach out helpfully into all the activities of our great nation, that are dependent on the transformation of matter. The public is to be congratulated upon the fact that the writer of the present volume is better qualified than any other man in the country to bring home to his readers some of the great results of modern chemical activity as well as some of the big problems which must continue to engage the attention of our chemists. Dr. Slosson has indeed the unique quality of combining an exact and intimate knowledge of chemistry with the exquisite clarity and pointedness of expression of a born writer. We have here an exposition by a master mind, an exposition shorn of the terrifying and obscuring technicalities of the lecture room, that will be as absorbing reading as any thrilling romance. For the story of scientific achievement is the greatest epic the world has ever known, and like the great national epics of bygone ages, should quicken the life of the nation by a realization of its powers and a picture of its possibilities. CREATIVE CHEMISTRY La Chimie posséde cette faculté créatrice à un degré plus éminent que les autres sciences, parce qu'elle pénètre plus profondément et atteint jusqu'aux éléments naturels des êtres. --_Berthelot_. I THREE PERIODS OF PROGRESS The story of Robinson Crusoe is an allegory of human history. Man is a castaway upon a desert planet, isolated from other inhabited worlds--if there be any such--by millions of miles of untraversable space. He is absolutely dependent upon his own exertions, for this world of his, as Wells says, has no imports except meteorites and no exports of any kind. Man has no wrecked ship from a former civilization to draw upon for tools and weapons, but must utilize as best he may such raw materials as he can find. In this conquest of nature by man there are three stages distinguishable: 1. The Appropriative Period 2. The Adaptive Period 3. The Creative Period These eras overlap, and the human race, or rather its vanguard, civilized man, may be passing into the third stage in one field of human endeavor while still lingering in the second or first in some other respect. But in any particular line this sequence is followed. The primitive man picks up whatever he can find available for his use. His successor in the next stage of culture shapes and develops this crude instrument until it becomes more suitable for his purpose. But in the course of time man often finds that he can make something new which is better than anything in nature or naturally produced. The savage discovers. The barbarian improves. The civilized man invents. The first finds. The second fashions. The third fabricates. The primitive man was a troglodyte. He sought shelter in any cave or crevice that he could find. Later he dug it out to make it more roomy and piled up stones at the entrance to keep out the wild beasts. This artificial barricade, this false façade, was gradually extended and solidified until finally man could build a cave for himself anywhere in the open field from stones he quarried out of the hill. But man was not content with such materials and now puts up a building which may be composed of steel, brick, terra cotta, glass, concrete and plaster, none of which materials are to be found in nature. The untutored savage might cross a stream astride a floating tree trunk. By and by it occurred to him to sit inside the log instead of on it, so he hollowed it out with fire or flint. Later, much later, he constructed an ocean liner. Cain, or whoever it was first slew his brother man, made use of a stone or stick. Afterward it was found a better weapon could be made by tying the stone to the end of the stick, and as murder developed into a fine art the stick was converted into the bow and this into the catapult and finally into the cannon, while the stone was developed into the high explosive projectile. The first music to soothe the savage breast was the soughing of the wind through the trees. Then strings were stretched across a crevice for the wind to play upon and there was the Æolian harp. The second stage was entered when Hermes strung the tortoise shell and plucked it with his fingers and when Athena, raising the wind from her own lungs, forced it through a hollow reed. From these beginnings we have the organ and the orchestra, producing such sounds as nothing in nature can equal. The first idol was doubtless a meteorite fallen from heaven or a fulgurite or concretion picked up from the sand, bearing some slight resemblance to a human being. Later man made gods in his own image, and so sculpture and painting grew until now the creations of futuristic art could be worshiped--if one wanted to--without violation of the second commandment, for they are not the likeness of anything that is in heaven above or that is in the earth beneath or that is in the water under the earth. In the textile industry the same development is observable. The primitive man used the skins of animals he had slain to protect his own skin. In the course of time he--or more probably his wife, for it is to the women rather than to the men that we owe the early steps in the arts and sciences--fastened leaves together or pounded out bark to make garments. Later fibers were plucked from the sheepskin, the cocoon and the cotton-ball, twisted together and woven into cloth. Nowadays it is possible to make a complete suit of clothes, from hat to shoes, of any desirable texture, form and color, and not include any substance to be found in nature. The first metals available were those found free in nature such as gold and copper. In a later age it was found possible to extract iron from its ores and today we have artificial alloys made of multifarious combinations of rare metals. The medicine man dosed his patients with decoctions of such roots and herbs as had a bad taste or queer look. The pharmacist discovered how to extract from these their medicinal principle such as morphine, quinine and cocaine, and the creative chemist has discovered how to make innumerable drugs adapted to specific diseases and individual idiosyncrasies. In the later or creative stages we enter the domain of chemistry, for it is the chemist alone who possesses the power of reducing a substance to its constituent atoms and from them producing substances entirely new. But the chemist has been slow to realize his unique power and the world has been still slower to utilize his invaluable services. Until recently indeed the leaders of chemical science expressly disclaimed what should have been their proudest boast. The French chemist Lavoisier in 1793 defined chemistry as "the science of analysis." The German chemist Gerhardt in 1844 said: "I have demonstrated that the chemist works in opposition to living nature, that he burns, destroys, analyzes, that the vital force alone operates by synthesis, that it reconstructs the edifice torn down by the chemical forces." It is quite true that chemists up to the middle of the last century were so absorbed in the destructive side of their science that they were blind to the constructive side of it. In this respect they were less prescient than their contemned predecessors, the alchemists, who, foolish and pretentious as they were, aspired at least to the formation of something new. It was, I think, the French chemist Berthelot who first clearly perceived the double aspect of chemistry, for he defined it as "the science of analysis _and synthesis_," of taking apart and of putting together. The motto of chemistry, as of all the empirical sciences, is _savoir c'est pouvoir_, to know in order to do. This is the pragmatic test of all useful knowledge. Berthelot goes on to say: Chemistry creates its object. This creative faculty, comparable to that of art itself, distinguishes it essentially from the natural and historical sciences.... These sciences do not control their object. Thus they are too often condemned to an eternal impotence in the search for truth of which they must content themselves with possessing some few and often uncertain fragments. On the contrary, the experimental sciences have the power to realize their conjectures.... What they dream of that they can manifest in actuality.... Chemistry possesses this creative faculty to a more eminent degree than the other sciences because it penetrates more profoundly and attains even to the natural elements of existences. Since Berthelot's time, that is, within the last fifty years, chemistry has won its chief triumphs in the field of synthesis. Organic chemistry, that is, the chemistry of the carbon compounds, so called because it was formerly assumed, as Gerhardt says, that they could only be formed by "vital force" of organized plants and animals, has taken a development far overshadowing inorganic chemistry, or the chemistry of mineral substances. Chemists have prepared or know how to prepare hundreds of thousands of such "organic compounds," few of which occur in the natural world. But this conception of chemistry is yet far from having been accepted by the world at large. This was brought forcibly to my attention during the publication of these chapters in "The Independent" by various letters, raising such objections as the following: When you say in your article on "What Comes from Coal Tar" that "Art can go ahead of nature in the dyestuff business" you have doubtless for the moment allowed your enthusiasm to sweep you away from the moorings of reason. Shakespeare, anticipating you and your "Creative Chemistry," has shown the utter untenableness of your position: Nature is made better by no mean, But nature makes that mean: so o'er that art, Which, you say, adds to nature, is an art That nature makes. How can you say that art surpasses nature when you know very well that nothing man is able to make can in any way equal the perfection of all nature's products? It is blasphemous of you to claim that man can improve the works of God as they appear in nature. Only the Creator can create. Man only imitates, destroys or defiles God's handiwork. No, it was not in momentary absence of mind that I claimed that man could improve upon nature in the making of dyes. I not only said it, but I proved it. I not only proved it, but I can back it up. I will give a million dollars to anybody finding in nature dyestuffs as numerous, varied, brilliant, pure and cheap as those that are manufactured in the laboratory. I haven't that amount of money with me at the moment, but the dyers would be glad to put it up for the discovery of a satisfactory natural source for their tinctorial materials. This is not an opinion of mine but a matter of fact, not to be decided by Shakespeare, who was not acquainted with the aniline products. Shakespeare in the passage quoted is indulging in his favorite amusement of a play upon words. There is a possible and a proper sense of the word "nature" that makes it include everything except the supernatural. Therefore man and all his works belong to the realm of nature. A tenement house in this sense is as "natural" as a bird's nest, a peapod or a crystal. But such a wide extension of the term destroys its distinctive value. It is more convenient and quite as correct to use "nature" as I have used it, in contradistinction to "art," meaning by the former the products of the mineral, vegetable and animal kingdoms, excluding the designs, inventions and constructions of man which we call "art." We cannot, in a general and abstract fashion, say which is superior, art or nature, because it all depends on the point of view. The worm loves a rotten log into which he can bore. Man prefers a steel cabinet into which the worm cannot bore. If man cannot improve Upon nature he has no motive for making anything. Artificial products are therefore superior to natural products as measured by man's convenience, otherwise they would have no reason for existence. Science and Christianity are at one in abhorring the natural man and calling upon the civilized man to fight and subdue him. The conquest of nature, not the imitation of nature, is the whole duty of man. Metchnikoff and St. Paul unite in criticizing the body we were born with. St. Augustine and Huxley are in agreement as to the eternal conflict between man and nature. In his Romanes lecture on "Evolution and Ethics" Huxley said: "The ethical progress of society depends, not on imitating the cosmic process, still less on running away from it, but on combating it," and again: "The history of civilization details the steps by which man has succeeded in building up an artificial world within the cosmos." There speaks the true evolutionist, whose one desire is to get away from nature as fast and far as possible. Imitate Nature? Yes, when we cannot improve upon her. Admire Nature? Possibly, but be not blinded to her defects. Learn from Nature? We should sit humbly at her feet until we can stand erect and go our own way. Love Nature? Never! She is our treacherous and unsleeping foe, ever to be feared and watched and circumvented, for at any moment and in spite of all our vigilance she may wipe out the human race by famine, pestilence or earthquake and within a few centuries obliterate every trace of its achievement. The wild beasts that man has kept at bay for a few centuries will in the end invade his palaces: the moss will envelop his walls and the lichen disrupt them. The clam may survive man by as many millennia as it preceded him. In the ultimate devolution of the world animal life will disappear before vegetable, the higher plants will be killed off before the lower, and finally the three kingdoms of nature will be reduced to one, the mineral. Civilized man, enthroned in his citadel and defended by all the forces of nature that he has brought under his control, is after all in the same situation as a savage, shivering in the darkness beside his fire, listening to the pad of predatory feet, the rustle of serpents and the cry of birds of prey, knowing that only the fire keeps his enemies off, but knowing too that every stick he lays on the fire lessens his fuel supply and hastens the inevitable time when the beasts of the jungle will make their fatal rush. Chaos is the "natural" state of the universe. Cosmos is the rare and temporary exception. Of all the million spheres this is apparently the only one habitable and of this only a small part--the reader may draw the boundaries to suit himself--can be called civilized. Anarchy is the natural state of the human race. It prevailed exclusively all over the world up to some five thousand years ago, since which a few peoples have for a time succeeded in establishing a certain degree of peace and order. This, however, can be maintained only by strenuous and persistent efforts, for society tends naturally to sink into the chaos out of which it has arisen. It is only by overcoming nature that man can rise. The sole salvation for the human race lies in the removal of the primal curse, the sentence of hard labor for life that was imposed on man as he left Paradise. Some folks are trying to elevate the laboring classes; some are trying to keep them down. The scientist has a more radical remedy; he wants to annihilate the laboring classes by abolishing labor. There is no longer any need for human labor in the sense of personal toil, for the physical energy necessary to accomplish all kinds of work may be obtained from external sources and it can be directed and controlled without extreme exertion. Man's first effort in this direction was to throw part of his burden upon the horse and ox or upon other men. But within the last century it has been discovered that neither human nor animal servitude is necessary to give man leisure for the higher life, for by means of the machine he can do the work of giants without exhaustion. But the introduction of machines, like every other step of human progress, met with the most violent opposition from those it was to benefit. "Smash 'em!" cried the workingman. "Smash 'em!" cried the poet. "Smash 'em!" cried the artist. "Smash 'em!" cried the theologian. "Smash 'em!" cried the magistrate. This opposition yet lingers and every new invention, especially in chemistry, is greeted with general distrust and often with legislative prohibition. Man is the tool-using animal, and the machine, that is, the power-driven tool, is his peculiar achievement. It is purely a creation of the human mind. The wheel, its essential feature, does not exist in nature. The lever, with its to-and-fro motion, we find in the limbs of all animals, but the continuous and revolving lever, the wheel, cannot be formed of bone and flesh. Man as a motive power is a poor thing. He can only convert three or four thousand calories of energy a day and he does that very inefficiently. But he can make an engine that will handle a hundred thousand times that, twice as efficiently and three times as long. In this way only can he get rid of pain and toil and gain the wealth he wants. Gradually then he will substitute for the natural world an artificial world, molded nearer to his heart's desire. Man the Artifex will ultimately master Nature and reign supreme over his own creation until chaos shall come again. In the ancient drama it was _deus ex machina_ that came in at the end to solve the problems of the play. It is to the same supernatural agency, the divinity in machinery, that we must look for the salvation of society. It is by means of applied science that the earth can be made habitable and a decent human life made possible. Creative evolution is at last becoming conscious. II NITROGEN PRESERVER AND DESTROYER OF LIFE In the eyes of the chemist the Great War was essentially a series of explosive reactions resulting in the liberation of nitrogen. Nothing like it has been seen in any previous wars. The first battles were fought with cellulose, mostly in the form of clubs. The next were fought with silica, mostly in the form of flint arrowheads and spear-points. Then came the metals, bronze to begin with and later iron. The nitrogenous era in warfare began when Friar Roger Bacon or Friar Schwartz--whichever it was--ground together in his mortar saltpeter, charcoal and sulfur. The Chinese, to be sure, had invented gunpowder long before, but they--poor innocents--did not know of anything worse to do with it than to make it into fire-crackers. With the introduction of "villainous saltpeter" war ceased to be the vocation of the nobleman and since the nobleman had no other vocation he began to become extinct. A bullet fired from a mile away is no respecter of persons. It is just as likely to kill a knight as a peasant, and a brave man as a coward. You cannot fence with a cannon ball nor overawe it with a plumed hat. The only thing you can do is to hide and shoot back. Now you cannot hide if you send up a column of smoke by day and a pillar of fire by night--the most conspicuous of signals--every time you shoot. So the next step was the invention of a smokeless powder. In this the oxygen necessary for the combustion is already in such close combination with its fuel, the carbon and hydrogen, that no black particles of carbon can get away unburnt. In the old-fashioned gunpowder the oxygen necessary for the combustion of the carbon and sulfur was in a separate package, in the molecule of potassium nitrate, and however finely the mixture was ground, some of the atoms, in the excitement of the explosion, failed to find their proper partners at the moment of dispersal. The new gunpowder besides being smokeless is ashless. There is no black sticky mass of potassium salts left to foul the gun barrel. The gunpowder period of warfare was actively initiated at the battle of Cressy, in which, as a contemporary historian says, "The English guns made noise like thunder and caused much loss in men and horses." Smokeless powder as invented by Paul Vieille was adopted by the French Government in 1887. This, then, might be called the beginning of the guncotton or nitrocellulose period--or, perhaps in deference to the caveman's club, the second cellulose period of human warfare. Better, doubtless, to call it the "high explosive period," for various other nitro-compounds besides guncotton are being used. The important thing to note is that all the explosives from gunpowder down contain nitrogen as the essential element. It is customary to call nitrogen "an inert element" because it was hard to get it into combination with other elements. It might, on the other hand, be looked upon as an active element because it acts so energetically in getting out of its compounds. We can dodge the question by saying that nitrogen is a most unreliable and unsociable element. Like Kipling's cat it walks by its wild lone. It is not so bad as Argon the Lazy and the other celibate gases of that family, where each individual atom goes off by itself and absolutely refuses to unite even temporarily with any other atom. The nitrogen atoms will pair off with each other and stick together, but they are reluctant to associate with other elements and when they do the combination is likely to break up any moment. You all know people like that, good enough when by themselves but sure to break up any club, church or society they get into. Now, the value of nitrogen in warfare is due to the fact that all the atoms desert in a body on the field of battle. Millions of them may be lying packed in a gun cartridge, as quiet as you please, but let a little disturbance start in the neighborhood--say a grain of mercury fulminate flares up--and all the nitrogen atoms get to trembling so violently that they cannot be restrained. The shock spreads rapidly through the whole mass. The hydrogen and carbon atoms catch up the oxygen and in an instant they are off on a stampede, crowding in every direction to find an exit, and getting more heated up all the time. The only movable side is the cannon ball in front, so they all pound against that and give it such a shove that it goes ten miles before it stops. The external bombardment by the cannon ball is, therefore, preceded by an internal bombardment on the cannon ball by the molecules of the hot gases, whose speed is about as great as the speed of the projectile that they propel. [Illustration: © Underwood & Underwood THE HAND GRENADES WHICH THESE WOMEN ARE BORING will contain potential chemical energy capable of causing a vast amount of destruction when released. During the war the American Government placed orders for 68,000,000 such grenades as are here shown.] [Illustration: © International Film Service, Inc. WOMEN IN A MUNITION PLANT ENGAGED IN THE MANUFACTURE OF TRI-NITRO-TOLUOL, THE MOST IMPORTANT OF MODERN HIGH EXPLOSIVES] The active agent in all these explosives is the nitrogen atom in combination with two oxygen atoms, which the chemist calls the "nitro group" and which he represents by NO_{2}. This group was, as I have said, originally used in the form of saltpeter or potassium nitrate, but since the chemist did not want the potassium part of it--for it fouled his guns--he took the nitro group out of the nitrate by means of sulfuric acid and by the same means hooked it on to some compound of carbon and hydrogen that would burn without leaving any residue, and give nothing but gases. One of the simplest of these hydrocarbon derivatives is glycerin, the same as you use for sunburn. This mixed with nitric and sulfuric acids gives nitroglycerin, an easy thing to make, though I should not advise anybody to try making it unless he has his life insured. But nitroglycerin is uncertain stuff to keep and being a liquid is awkward to handle. So it was mixed with sawdust or porous earth or something else that would soak it up. This molded into sticks is our ordinary dynamite. If instead of glycerin we take cellulose in the form of wood pulp or cotton and treat this with nitric acid in the presence of sulfuric we get nitrocellulose or guncotton, which is the chief ingredient of smokeless powder. Now guncotton looks like common cotton. It is too light and loose to pack well into a gun. So it is dissolved with ether and alcohol or acetone to make a plastic mass that can be molded into rods and cut into grains of suitable shape and size to burn at the proper speed. Here, then, we have a liquid explosive, nitroglycerin, that has to be soaked up in some porous solid, and a porous solid, guncotton, that has to soak up some liquid. Why not solve both difficulties together by dissolving the guncotton in the nitroglycerin and so get a double explosive? This is a simple idea. Any of us can see the sense of it--once it is suggested to us. But Alfred Nobel, the Swedish chemist, who thought it out first in 1878, made millions out of it. Then, apparently alarmed at the possible consequences of his invention, he bequeathed the fortune he had made by it to found international prizes for medical, chemical and physical discoveries, idealistic literature and the promotion of peace. But his posthumous efforts for the advancement of civilization and the abolition of war did not amount to much and his high explosives were later employed to blow into pieces the doctors, chemists, authors and pacifists he wished to reward. Nobel's invention, "cordite," is composed of nitroglycerin and nitrocellulose with a little mineral jelly or vaseline. Besides cordite and similar mixtures of nitroglycerin and nitrocellulose there are two other classes of high explosives in common use. One is made from carbolic acid, which is familiar to us all by its use as a disinfectant. If this is treated with nitric and sulfuric acids we get from it picric acid, a yellow crystalline solid. Every government has its own secret formula for this type of explosive. The British call theirs "lyddite," the French "melinite" and the Japanese "shimose." The third kind of high explosives uses as its base toluol. This is not so familiar to us as glycerin, cotton or carbolic acid. It is one of the coal tar products, an inflammable liquid, resembling benzene. When treated with nitric acid in the usual way it takes up like the others three nitro groups and so becomes tri-nitro-toluol. Realizing that people could not be expected to use such a mouthful of a word, the chemists have suggested various pretty nicknames, trotyl, tritol, trinol, tolite and trilit, but the public, with the wilfulness it always shows in the matter of names, persists in calling it TNT, as though it were an author like G.B.S., or G.K.C, or F.P.A. TNT is the latest of these high explosives and in some ways the best of them. Picric acid has the bad habit of attacking the metals with which it rests in contact forming sensitive picrates that are easily set off, but TNT is inert toward metals and keeps well. TNT melts far below the boiling point of water so can be readily liquefied and poured into shells. It is insensitive to ordinary shocks. A rifle bullet can be fired through a case of it without setting it off, and if lighted with a match it burns quietly. The amazing thing about these modern explosives, the organic nitrates, is the way they will stand banging about and burning, yet the terrific violence with which they blow up when shaken by an explosive wave of a particular velocity like that of a fulminating cap. Like picric acid, TNT stains the skin yellow and causes soreness and sometimes serious cases of poisoning among the employees, mostly girls, in the munition factories. On the other hand, the girls working with cordite get to using it as chewing gum; a harmful habit, not because of any danger of being blown up by it, but because nitroglycerin is a heart stimulant and they do not need that. [Illustration: The Genealogical Tree of Nitric Acid From W.Q. Whitman's "The Story of Nitrates in the War," _General Science Quarterly_] TNT is by no means smokeless. The German shells that exploded with a cloud of black smoke and which British soldiers called "Black Marias," "coal-boxes" or "Jack Johnsons" were loaded with it. But it is an advantage to have a shell show where it strikes, although a disadvantage to have it show where it starts. It is these high explosives that have revolutionized warfare. As soon as the first German shell packed with these new nitrates burst inside the Gruson cupola at Liège and tore out its steel and concrete by the roots the world knew that the day of the fixed fortress was gone. The armies deserted their expensively prepared fortifications and took to the trenches. The British troops in France found their weapons futile and sent across the Channel the cry of "Send us high explosives or we perish!" The home Government was slow to heed the appeal, but no progress was made against the Germans until the Allies had the means to blast them out of their entrenchments by shells loaded with five hundred pounds of TNT. All these explosives are made from nitric acid and this used to be made from nitrates such as potassium nitrate or saltpeter. But nitrates are rarely found in large quantities. Napoleon and Lee had a hard time to scrape up enough saltpeter from the compost heaps, cellars and caves for their gunpowder, and they did not use as much nitrogen in a whole campaign as was freed in a few days' cannonading on the Somme. Now there is one place in the world--and so far as we know one only--where nitrates are to be found abundantly. This is in a desert on the western slope of the Andes where ancient guano deposits have decomposed and there was not enough rain to wash away their salts. Here is a bed two miles wide, two hundred miles long and five feet deep yielding some twenty to fifty per cent. of sodium nitrate. The deposit originally belonged to Peru, but Chile fought her for it and got it in 1881. Here all countries came to get their nitrates for agriculture and powder making. Germany was the largest customer and imported 750,000 tons of Chilean nitrate in 1913, besides using 100,000 tons of other nitrogen salts. By this means her old, wornout fields were made to yield greater harvests than our fresh land. Germany and England were like two duelists buying powder at the same shop. The Chilean Government, pocketing an export duty that aggregated half a billion dollars, permitted the saltpeter to be shoveled impartially into British and German ships, and so two nitrogen atoms, torn from their Pacific home and parted, like Evangeline and Gabriel, by transportation oversea, may have found themselves flung into each other's arms from the mouths of opposing howitzers in the air of Flanders. Goethe could write a romance on such a theme. Now the moment war broke out this source of supply was shut off to both parties, for they blockaded each other. The British fleet closed up the German ports while the German cruisers in the Pacific took up a position off the coast of Chile in order to intercept the ships carrying nitrates to England and France. The Panama Canal, designed to afford relief in such an emergency, caved in most inopportunely. The British sent a fleet to the Pacific to clear the nitrate route, but it was outranged and defeated on November 1, 1914. Then a stronger British fleet was sent out and smashed the Germans off the Falkland Islands on December 8. But for seven weeks the nitrate route had been closed while the chemical reactions on the Marne and Yser were decomposing nitrogen-compounds at an unheard of rate. England was now free to get nitrates for her munition factories, but Germany was still bottled up. She had stored up Chilean nitrates in anticipation of the war and as soon as it was seen to be coming she bought all she could get in Europe. But this supply was altogether inadequate and the war would have come to an end in the first winter if German chemists had not provided for such a contingency in advance by working out methods of getting nitrogen from the air. Long ago it was said that the British ruled the sea and the French the land so that left nothing to the German but the air. The Germans seem to have taken this jibe seriously and to have set themselves to make the most of the aerial realm in order to challenge the British and French in the fields they had appropriated. They had succeeded so far that the Kaiser when he declared war might well have considered himself the Prince of the Power of the Air. He had a fleet of Zeppelins and he had means for the fixation of nitrogen such as no other nation possessed. The Zeppelins burst like wind bags, but the nitrogen plants worked and made Germany independent of Chile not only during the war, but in the time of peace. Germany during the war used 200,000 tons of nitric acid a year in explosives, yet her supply of nitrogen is exhaustless. [Illustration: World production and consumption of fixed inorganic nitrogen expressed in tons nitrogen From _The Journal of Industrial and Engineering Chemistry_, March, 1919.] Nitrogen is free as air. That is the trouble; it is too free. It is fixed nitrogen that we want and that we are willing to pay for; nitrogen in combination with some other elements in the form of food or fertilizer so we can make use of it as we set it free. Fixed nitrogen in its cheapest form, Chile saltpeter, rose to $250 during the war. Free nitrogen costs nothing and is good for nothing. If a land-owner has a right to an expanding pyramid of air above him to the limits of the atmosphere--as, I believe, the courts have decided in the eaves-dropping cases--then for every square foot of his ground he owns as much nitrogen as he could buy for $2500. The air is four-fifths free nitrogen and if we could absorb it in our lungs as we do the oxygen of the other fifth a few minutes breathing would give us a full meal. But we let this free nitrogen all out again through our noses and then go and pay 35 cents a pound for steak or 60 cents a dozen for eggs in order to get enough combined nitrogen to live on. Though man is immersed in an ocean of nitrogen, yet he cannot make use of it. He is like Coleridge's "Ancient Mariner" with "water, water, everywhere, nor any drop to drink." Nitrogen is, as Hood said not so truly about gold, "hard to get and hard to hold." The bacteria that form the nodules on the roots of peas and beans have the power that man has not of utilizing free nitrogen. Instead of this quiet inconspicuous process man has to call upon the lightning when he wants to fix nitrogen. The air contains the oxygen and nitrogen which it is desired to combine to form nitrates but the atoms are paired, like to like. Passing an electric spark through the air breaks up some of these pairs and in the confusion of the shock the lonely atoms seize on their nearest neighbor and so may get partners of the other sort. I have seen this same thing happen in a square dance where somebody made a blunder. It is easy to understand the reaction if we represent the atoms of oxygen and nitrogen by the initials of their names in this fashion: NN + OO --> NO + NO nitrogen oxygen nitric oxide The --> represents Jove's thunderbolt, a stroke of artificial lightning. We see on the left the molecules of oxygen and nitrogen, before taking the electric treatment, as separate elemental pairs, and then to the right of the arrow we find them as compound molecules of nitric oxide. This takes up another atom of oxygen from the air and becomes NOO, or using a subscript figure to indicate the number of atoms and so avoid repeating the letter, NO_{2} which is the familiar nitro group of nitric acid (HO--NO_{2}) and of its salts, the nitrates, and of its organic compounds, the high explosives. The NO_{2} is a brown and evil-smelling gas which when dissolved in water (HOH) and further oxidized is completely converted into nitric acid. The apparatus which effects this transformation is essentially a gigantic arc light in a chimney through which a current of hot air is blown. The more thoroughly the air comes under the action of the electric arc the more molecules of nitrogen and oxygen will be broken up and rearranged, but on the other hand if the mixture of gases remains in the path of the discharge the NO molecules are also broken up and go back into their original form of NN and OO. So the object is to spread out the electric arc as widely as possible and then run the air through it rapidly. In the Schönherr process the electric arc is a spiral flame twenty-three feet long through which the air streams with a vortex motion. In the Birkeland-Eyde furnace there is a series of semi-circular arcs spread out by the repellent force of a powerful electric magnet in a flaming disc seven feet in diameter with a temperature of 6300° F. In the Pauling furnace the electrodes between which the current strikes are two cast iron tubes curving upward and outward like the horns of a Texas steer and cooled by a stream of water passing through them. These electric furnaces produce two or three ounces of nitric acid for each kilowatt-hour of current consumed. Whether they can compete with the natural nitrates and the products of other processes depends upon how cheaply they can get their electricity. Before the war there were several large installations in Norway and elsewhere where abundant water power was available and now the Norwegians are using half a million horse power continuously in the fixation of nitrogen and the rest of the world as much again. The Germans had invested largely in these foreign oxidation plants, but shortly before the war they had sold out and turned their attention to other processes not requiring so much electrical energy, for their country is poorly provided with water power. The Haber process, that they made most of, is based upon as simple a reaction as that we have been considering, for it consists in uniting two elemental gases to make a compound, but the elements in this case are not nitrogen and oxygen, but nitrogen and hydrogen. This gives ammonia instead of nitric acid, but ammonia is useful for its own purposes and it can be converted into nitric acid if this is desired. The reaction is: NN + HH + HH + HH --> NHHH + NHHH Nitrogen hydrogen ammonia The animals go in two by two, but they come out four by four. Four molecules of the mixed elements are turned into two molecules and so the gas shrinks to half its volume. At the same time it acquires an odor--familiar to us when we are curing a cold--that neither of the original gases had. The agent that effects the transformation in this case is not the electric spark--for this would tend to work the reaction backwards--but uranium, a rare metal, which has the peculiar property of helping along a reaction while seeming to take no part in it. Such a substance is called a catalyst. The action of a catalyst is rather mysterious and whenever we have a mystery we need an analogy. We may, then, compare the catalyst to what is known as "a good mixer" in society. You know the sort of man I mean. He may not be brilliant or especially talkative, but somehow there is always "something doing" at a picnic or house-party when he is along. The tactful hostess, the salon leader, is a social catalyst. The trouble with catalysts, either human or metallic, is that they are rare and that sometimes they get sulky and won't work if the ingredients they are supposed to mix are unsuitable. But the uranium, osmium, platinum or whatever metal is used as a catalyzing agent is expensive and although it is not used up it is easily "poisoned," as the chemists say, by impurities in the gases. The nitrogen and the hydrogen for the Haber process must then be prepared and purified before trying to combine them into ammonia. The nitrogen is obtained by liquefying air by cold and pressure and then boiling off the nitrogen at 194° C. The oxygen left is useful for other purposes. The hydrogen needed is extracted by a similar process of fractional distillation from "water-gas," the blue-flame burning gas used for heating. Then the nitrogen and hydrogen, mixed in the proportion of one to three, as shown in the reaction given above, are compressed to two hundred atmospheres, heated to 1300° F. and passed over the finely divided uranium. The stream of gas that comes out contains about four per cent. of ammonia, which is condensed to a liquid by cooling and the uncombined hydrogen and nitrogen passed again through the apparatus. The ammonia can be employed in refrigeration and other ways but if it is desired to get the nitrogen into the form of nitric acid it has to be oxidized by the so-called Ostwald process. This is the reaction: NH_{3} + 4O --> HNO_{3} + H_{2}O ammonia oxygen nitric acid water The catalyst used to effect this combination is the metal platinum in the form of fine wire gauze, since the action takes place only on the surface. The ammonia gas is mixed with air which supplies the oxygen and the heated mixture run through the platinum gauze at the rate of several yards a second. Although the gases come in contact with the platinum only a five-hundredth part of a second yet eighty-five per cent. is converted into nitric acid. The Haber process for the making of ammonia by direct synthesis from its constituent elements and the supplemental Ostwald process for the conversion of the ammonia into nitric acid were the salvation of Germany. As soon as the Germans saw that their dash toward Paris had been stopped at the Marne they knew that they were in for a long war and at once made plans for a supply of fixed nitrogen. The chief German dye factories, the Badische Anilin and Soda-Fabrik, promptly put $100,000,000 into enlarging its plant and raised its production of ammonium sulfate from 30,000 to 300,000 tons. One German electrical firm with aid from the city of Berlin contracted to provide 66,000,000 pounds of fixed nitrogen a year at a cost of three cents a pound for the next twenty-five years. The 750,000 tons of Chilean nitrate imported annually by Germany contained about 116,000 tons of the essential element nitrogen. The fourteen large plants erected during the war can fix in the form of nitrates 500,000 tons of nitrogen a year, which is more than twice the amount needed for internal consumption. So Germany is now not only independent of the outside world but will have a surplus of nitrogen products which could be sold even in America at about half what the farmer has been paying for South American saltpeter. Besides the Haber or direct process there are other methods of making ammonia which are, at least outside of Germany, of more importance. Most prominent of these is the cyanamid process. This requires electrical power since it starts with a product of the electrical furnace, calcium carbide, familiar to us all as a source of acetylene gas. If a stream of nitrogen is passed over hot calcium carbide it is taken up by the carbide according to the following equation: CaC_{2} + N_{2} --> CaCN_{2} + C calcium carbide nitrogen calcium cyanamid carbon Calcium cyanamid was discovered in 1895 by Caro and Franke when they were trying to work out a new process for making cyanide to use in extracting gold. It looks like stone and, under the name of lime-nitrogen, or Kalkstickstoff, or nitrolim, is sold as a fertilizer. If it is desired to get ammonia, it is treated with superheated steam. The reaction produces heat and pressure, so it is necessary to carry it on in stout autoclaves or enclosed kettles. The cyanamid is completely and quickly converted into pure ammonia and calcium carbonate, which is the same as the limestone from which carbide was made. The reaction is: CaCN_{2} + 3H_{2}O --> CaCO_{3} + 2NH_{3} calcium cyanamid water calcium carbonate ammonia Another electrical furnace method, the Serpek process, uses aluminum instead of calcium for the fixation of nitrogen. Bauxite, or impure aluminum oxide, the ordinary mineral used in the manufacture of metallic aluminum, is mixed with coal and heated in a revolving electrical furnace through which nitrogen is passing. The equation is: Al_{2}O_{3} + 3C + N_{2} --> 2AlN + 3CO aluminum carbon nitrogen aluminum carbon oxide nitride monoxide Then the aluminum nitride is treated with steam under pressure, which produces ammonia and gives back the original aluminum oxide, but in a purer form than the mineral from which was made 2AlN + 3H_{2}O --> 2NH_{3} + Al_{2}O_{3} Aluminum water ammonia aluminum oxide nitride The Serpek process is employed to some extent in France in connection with the aluminum industry. These are the principal processes for the fixation of nitrogen now in use, but they by no means exhaust the possibilities. For instance, Professor John C. Bucher, of Brown University, created a sensation in 1917 by announcing a new process which he had worked out with admirable completeness and which has some very attractive features. It needs no electric power or high pressure retorts or liquid air apparatus. He simply fills a twenty-foot tube with briquets made out of soda ash, iron and coke and passes producer gas through the heated tube. Producer gas contains nitrogen since it is made by passing air over hot coal. The reaction is: 2Na_{2}CO_{3} + 4C + N_{2} = 2NaCN + 3CO sodium carbon nitrogen sodium carbon carbonate cyanide monoxide The iron here acts as the catalyst and converts two harmless substances, sodium carbonate, which is common washing soda, and carbon, into two of the most deadly compounds known to man, cyanide and carbon monoxide, which is what kills you when you blow out the gas. Sodium cyanide is a salt of hydrocyanic acid, which for, some curious reason is called "Prussic acid." It is so violent a poison that, as the freshman said in a chemistry recitation, "a single drop of it placed on the tongue of a dog will kill a man." But sodium cyanide is not only useful in itself, for the extraction of gold and cleaning of silver, but can be converted into ammonia, and a variety of other compounds such as urea and oxamid, which are good fertilizers; sodium ferrocyanide, that makes Prussian blue; and oxalic acid used in dyeing. Professor Bucher claimed that his furnace could be set up in a day at a cost of less than $100 and could turn out 150 pounds of sodium cyanide in twenty-four hours. This process was placed freely at the disposal of the United States Government for the war and a 10-ton plant was built at Saltville, Va., by the Ordnance Department. But the armistice put a stop to its operations and left the future of the process undetermined. [Illustration: A CHEMICAL REACTION ON A LARGE SCALE From the chemist's standpoint modern warfare consists in the rapid liberation of nitrogen from its compounds] [Illustration: Courtesy of E.I. du Pont de Nemours Co. BURNING AIR IN A BIRKELAND-EYDE FURNACE AT THE DU PONT PLANT An electric arc consuming about 4000 horse-power of energy is passing between the U-shaped electrodes which are made of copper tube cooled by an internal current of water. On the sides of the chamber are seen the openings through which the air passes impinging directly on both sides of the surface of the disk of flame. This flame is approximately seven feet in diameter and appears to be continuous although an alternating current of fifty cycles a second is used. The electric arc is spread into this disk flame by the repellent power of an electro-magnet the pointed pole of which is seen at bottom of the picture. Under this intense heat a part of the nitrogen and oxygen of the air combine to form oxides of nitrogen which when dissolved in water form the nitric acid used in explosives.] [Illustration: Courtesy of E.I. du Pont de Nemours Co. A BATTERY OF BIRKELAND-EYDE FURNACES FOR THE FIXATION OF NITROGEN AT THE DU PONT PLANT] We might have expected that the fixation of nitrogen by passing an electrical spark through hot air would have been an American invention, since it was Franklin who snatched the lightning from the heavens as well as the scepter from the tyrant and since our output of hot air is unequaled by any other nation. But little attention was paid to the nitrogen problem until 1916 when it became evident that we should soon be drawn into a war "with a first class power." On June 3, 1916, Congress placed $20,000,000 at the disposal of the president for investigation of "the best, cheapest and most available means for the production of nitrate and other products for munitions of war and useful in the manufacture of fertilizers and other useful products by water power or any other power." But by the time war was declared on April 6, 1917, no definite program had been approved and by the time the armistice was signed on November 11, 1918, no plants were in active operation. But five plants had been started and two of them were nearly ready to begin work when they were closed by the ending of the war. United States Nitrate Plant No. 1 was located at Sheffield, Alabama, and was designed for the production of ammonia by "direct action" from nitrogen and hydrogen according to the plans of the American Chemical Company. Its capacity was calculated at 60,000 pounds of anhydrous ammonia a day, half of which was to be oxidized to nitric acid. Plant No. 2 was erected at Muscle Shoals, Alabama, to use the process of the American Cyanamid Company. This was contracted to produce 110,000 tons of ammonium nitrate a year and later two other cyanamid plants of half that capacity were started at Toledo and Ancor, Ohio. At Muscle Shoals a mushroom city of 20,000 sprang up on an Alabama cotton field in six months. The raw material, air, was as abundant there as anywhere and the power, water, could be obtained from the Government hydro-electric plant on the Tennessee River, but this was not available during the war, so steam was employed instead. The heat of the coal was used to cool the air down to the liquefying point. The principle of this process is simple. Everybody knows that heat expands and cold contracts, but not everybody has realized the converse of this rule, that expansion cools and compression heats. If air is forced into smaller space, as in a tire pump, it heats up and if allowed to expand to ordinary pressure it cools off again. But if the air while compressed is cooled and then allowed to expand it must get still colder and the process can go on till it becomes cold enough to congeal. That is, by expanding a great deal of air, a little of it can be reduced to the liquefying point. At Muscle Shoals the plant for liquefying air, in order to get the nitrogen out of it, consisted of two dozen towers each capable of producing 1765 cubic feet of pure nitrogen per hour. The air was drawn in through two pipes, a yard across, and passed through scrubbing towers to remove impurities. The air was then compressed to 600 pounds per square inch. Nine tenths of the air was permitted to expand to 50 pounds and this expansion cooled down the other tenth, still under high pressure, to the liquefying point. Rectifying towers 24 feet high were stacked with trays of liquid air from which the nitrogen was continually bubbling off since its boiling point is twelve degrees centigrade lower than that of oxygen. Pure nitrogen gas collected at the top of the tower and the residual liquid air, now about half oxygen, was allowed to escape at the bottom. The nitrogen was then run through pipes into the lime-nitrogen ovens. There were 1536 of these about four feet square and each holding 1600 pounds of pulverized calcium carbide. This is at first heated by an electrical current to start the reaction which afterwards produces enough heat to keep it going. As the stream of nitrogen gas passes over the finely divided carbide it is absorbed to form calcium cyanamid as described on a previous page. This product is cooled, powdered and wet to destroy any quicklime or carbide left unchanged. Then it is charged into autoclaves and steam at high temperature and pressure is admitted. The steam acting on the cyanamid sets free ammonia gas which is carried to towers down which cold water is sprayed, giving the ammonia water, familiar to the kitchen and the bathroom. But since nitric acid rather than ammonia was needed for munitions, the oxygen of the air had to be called into play. This process, as already explained, is carried on by aid of a catalyzer, in this case platinum wire. At Muscle Shoals there were 696 of these catalyzer boxes. The ammonia gas, mixed with air to provide the necessary oxygen, was admitted at the top and passed down through a sheet of platinum gauze of 80 mesh to the inch, heated to incandescence by electricity. In contact with this the ammonia is converted into gaseous oxides of nitrogen (the familiar red fumes of the laboratory) which, carried off in pipes, cooled and dissolved in water, form nitric acid. But since none of the national plants could be got into action during the war, the United States was compelled to draw upon South America for its supply. The imports of Chilean saltpeter rose from half a million tons in 1914 to a million and a half in 1917. After peace was made the Department of War turned over to the Department of Agriculture its surplus of saltpeter, 150,000 tons, and it was sold to American farmers at cost, $81 a ton. For nitrogen plays a double rôle in human economy. It appears like Brahma in two aspects, Vishnu the Preserver and Siva the Destroyer. Here I have been considering nitrogen in its maleficent aspect, its use in war. We now turn to its beneficent aspect, its use in peace. III FEEDING THE SOIL The Great War not only starved people: it starved the land. Enough nitrogen was thrown away in some indecisive battle on the Aisne to save India from a famine. The population of Europe as a whole has not been lessened by the war, but the soil has been robbed of its power to support the population. A plant requires certain chemical elements for its growth and all of these must be within reach of its rootlets, for it will accept no substitutes. A wheat stalk in France before the war had placed at its feet nitrates from Chile, phosphates from Florida and potash from Germany. All these were shut off by the firing line and the shortage of shipping. Out of the eighty elements only thirteen are necessary for crops. Four of these are gases: hydrogen, oxygen, nitrogen and chlorine. Five are metals: potassium, magnesium, calcium, iron and sodium. Four are non-metallic solids: carbon, sulfur, phosphorus and silicon. Three of these, hydrogen, oxygen and carbon, making up the bulk of the plant, are obtainable _ad libitum_ from the air and water. The other ten in the form of salts are dissolved in the water that is sucked up from the soil. The quantity needed by the plant is so small and the quantity contained in the soil is so great that ordinarily we need not bother about the supply except in case of three of them. They are nitrogen, potassium and phosphorus. These would be useless or fatal to plant life in the elemental form, but fixed in neutral salt they are essential plant foods. A ton of wheat takes away from the soil about 47 pounds of nitrogen, 18 pounds of phosphoric acid and 12 pounds of potash. If then the farmer does not restore this much to his field every year he is drawing upon his capital and this must lead to bankruptcy in the long run. So much is easy to see, but actually the question is extremely complicated. When the German chemist, Justus von Liebig, pointed out in 1840 the possibility of maintaining soil fertility by the application of chemicals it seemed at first as though the question were practically solved. Chemists assumed that all they had to do was to analyze the soil and analyze the crop and from this figure out, as easily as balancing a bank book, just how much of each ingredient would have to be restored to the soil every year. But somehow it did not work out that way and the practical agriculturist, finding that the formulas did not fit his farm, sneered at the professors and whenever they cited Liebig to him he irreverently transposed the syllables of the name. The chemist when he went deeper into the subject saw that he had to deal with the colloids, damp, unpleasant, gummy bodies that he had hitherto fought shy of because they would not crystallize or filter. So the chemist called to his aid the physicist on the one hand and the biologist on the other and then they both had their hands full. The physicist found that he had to deal with a polyvariant system of solids, liquids and gases mutually miscible in phases too numerous to be handled by Gibbs's Rule. The biologist found that he had to deal with the invisible flora and fauna of a new world. Plants obey the injunction of Tennyson and rise on the stepping stones of their dead selves to higher things. Each successive generation lives on what is left of the last in the soil plus what it adds from the air and sunshine. As soon as a leaf or tree trunk falls to the ground it is taken in charge by a wrecking crew composed of a myriad of microscopic organisms who proceed to break it up into its component parts so these can be used for building a new edifice. The process is called "rotting" and the product, the black, gummy stuff of a fertile soil, is called "humus." The plants, that is, the higher plants, are not able to live on their own proteids as the animals are. But there are lower plants, certain kinds of bacteria, that can break up the big complicated proteid molecules into their component parts and reduce the nitrogen in them to ammonia or ammonia-like compounds. Having done this they stop and turn over the job to another set of bacteria to be carried through the next step. For you must know that soil society is as complex and specialized as that above ground and the tiniest bacterium would die rather than violate the union rules. The second set of bacteria change the ammonia over to nitrites and then a third set, the Amalgamated Union of Nitrate Workers, steps in and completes the process of oxidation with an efficiency that Ostwald might envy, for ninety-six per cent. of the ammonia of the soil is converted into nitrates. But if the conditions are not just right, if the food is insufficient or unwholesome or if the air that circulates through the soil is contaminated with poison gases, the bacteria go on a strike. The farmer, not seeing the thing from the standpoint of the bacteria, says the soil is "sick" and he proceeds to doctor it according to his own notion of what ails it. First perhaps he tries running in strike breakers. He goes to one of the firms that makes a business of supplying nitrogen-fixing bacteria from the scabs or nodules of the clover roots and scatters these colonies over the field. But if the living conditions remain bad the newcomers will soon quit work too and the farmer loses his money. If he is wise, then, he will remedy the conditions, putting a better ventilation system in his soil perhaps or neutralizing the sourness by means of lime or killing off the ameboid banditti that prey upon the peaceful bacteria engaged in the nitrogen industry. It is not an easy job that the farmer has in keeping billions of billions of subterranean servants contented and working together, but if he does not succeed at this he wastes his seed and labor. The layman regards the soil as a platform or anchoring place on which to set plants. He measures its value by its superficial area without considering its contents, which is as absurd as to estimate a man's wealth by the size of his safe. The difference in point of view is well illustrated by the old story of the city chap who was showing his farmer uncle the sights of New York. When he took him to Central Park he tried to astonish him by saying "This land is worth $500,000 an acre." The old farmer dug his toe into the ground, kicked out a clod, broke it open, looked at it, spit on it and squeezed it in his hand and then said, "Don't you believe it; 'tain't worth ten dollars an acre. Mighty poor soil I call it." Both were right. [Illustration: Courtesy of American Cyanamid Co. FIXING NITROGEN BY CALCIUM CARBIDE A view of the oven room in the plant of the American Cyanamid Company. The steel cylinders standing in the background are packed with the carbide and then put into the ovens sunk in the floor. When these are heated internally by electricity to 2000 degrees Fahrenheit pure nitrogen is let in and absorbed by the carbide, making cyanamid, which may be used as a fertilizer or for ammonia.] [Illustration: Photo by International Film Service A BARROW FULL OF POTASH SALTS EXTRACTED FROM SIX TONS OF GREEN KELP BY THE GOVERNMENT CHEMISTS] [Illustration: NATURE'S SILENT METHOD OF NITROGEN FIXATION The nodules on the vetch roots contain colonies of bacteria which have the power of taking the free nitrogen out of the air and putting it in compounds suitable for plant food.] The modern agriculturist realizes that the soil is a laboratory for the production of plant food and he ordinarily takes more pains to provide a balanced ration for it than he does for his family. Of course the necessity of feeding the soil has been known ever since man began to settle down and the ancient methods of maintaining its fertility, though discovered accidentally and followed blindly, were sound and efficacious. Virgil, who like Liberty Hyde Bailey was fond of publishing agricultural bulletins in poetry, wrote two thousand years ago: But sweet vicissitudes of rest and toil Make easy labor and renew the soil Yet sprinkle sordid ashes all around And load with fatt'ning dung thy fallow soil. The ashes supplied the potash and the dung the nitrate and phosphate. Long before the discovery of the nitrogen-fixing bacteria, the custom prevailed of sowing pea-like plants every third year and then plowing them under to enrich the soil. But such local supplies were always inadequate and as soon as deposits of fertilizers were discovered anywhere in the world they were drawn upon. The richest of these was the Chincha Islands off the coast of Peru, where millions of penguins and pelicans had lived in a most untidy manner for untold centuries. The guano composed of the excrement of the birds mixed with the remains of dead birds and the fishes they fed upon was piled up to a depth of 120 feet. From this Isle of Penguins--which is not that described by Anatole France--a billion dollars' worth of guano was taken and the deposit was soon exhausted. Then the attention of the world was directed to the mainland of Peru and Chile, where similar guano deposits had been accumulated and, not being washed away on account of the lack of rain, had been deposited as sodium nitrate, or "saltpeter." These beds were discovered by a German, Taddeo Haenke, in 1809, but it was not until the last quarter of the century that the nitrates came into common use as a fertilizer. Since then more than 53,000,000 tons have been taken out of these beds and the exportation has risen to a rate of 2,500,000 to 3,000,000 tons a year. How much longer they will last is a matter of opinion and opinion is largely influenced by whether you have your money invested in Chilean nitrate stock or in one of the new synthetic processes for making nitrates. The United States Department of Agriculture says the nitrate beds will be exhausted in a few years. On the other hand the Chilean Inspector General of Nitrate Deposits in his latest official report says that they will last for two hundred years at the present rate and that then there are incalculable areas of low grade deposits, containing less than eleven per cent., to be drawn upon. Anyhow, the South American beds cannot long supply the world's need of nitrates and we shall some time be starving unless creative chemistry comes to the rescue. In 1898 Sir William Crookes--the discoverer of the "Crookes tubes," the radiometer and radiant matter--startled the British Association for the Advancement of Science by declaring that the world was nearing the limit of wheat production and that by 1931 the bread-eaters, the Caucasians, would have to turn to other grains or restrict their population while the rice and millet eaters of Asia would continue to increase. Sir William was laughed at then as a sensationalist. He was, but his sensations were apt to prove true and it is already evident that he was too near right for comfort. Before we were half way to the date he set we had two wheatless days a week, though that was because we persisted in shooting nitrates into the air. The area producing wheat was by decades:[1] THE WHEAT FIELDS OF THE WORLD Acres 1881-90 192,000,000 1890-1900 211,000,000 1900-10 242,000,000 Probable limit 300,000,000 If 300,000,000 acres can be brought under cultivation for wheat and the average yield raised to twenty bushels to the acre, that will give enough to feed a billion people if they eat six bushels a year as do the English. Whether this maximum is correct or not there is evidently some limit to the area which has suitable soil and climate for growing wheat, so we are ultimately thrown back upon Crookes's solution of the problem; that is, we must increase the yield per acre and this can only be done by the use of fertilizers and especially by the fixation of atmospheric nitrogen. Crookes estimated the average yield of wheat at 12.7 bushels to the acre, which is more than it is in the new lands of the United States, Australia and Russia, but less than in Europe, where the soil is well fed. What can be done to increase the yield may be seen from these figures: GAIN IN THE YIELD OF WHEAT IN BUSHELS PER ACRE 1889-90 1913 Germany 19 35 Belgium 30 35 France 17 20 United Kingdom 28 32 United States 12 15 The greatest gain was made in Germany and we see a reason for it in the fact that the German importation of Chilean saltpeter was 55,000 tons in 1880 and 747,000 tons in 1913. In potatoes, too, Germany gets twice as big a crop from the same ground as we do, 223 bushels per acre instead of our 113 bushels. But the United States uses on the average only 28 pounds of fertilizer per acre, while Europe uses 200. It is clear that we cannot rely upon Chile, but make nitrates for ourselves as Germany had to in war time. In the first chapter we considered the new methods of fixing the free nitrogen from the air. But the fixation of nitrogen is a new business in this country and our chief reliance so far has been the coke ovens. When coal is heated in retorts or ovens for making coke or gas a lot of ammonia comes off with the other products of decomposition and is caught in the sulfuric acid used to wash the gas as ammonium sulfate. Our American coke-makers have been in the habit of letting this escape into the air and consequently we have been losing some 700,000 tons of ammonium salts every year, enough to keep our land rich and give us all the explosives we should need. But now they are reforming and putting in ovens that save the by-products such as ammonia and coal tar, so in 1916 we got from this source 325,000 tons a year. [Illustration: Courtesy of _Scientific American_. Consumption of potash for agricultural purposes in different countries] Germany had a natural monopoly of potash as Chile had a natural monopoly of nitrates. The agriculture of Europe and America has been virtually dependent upon these two sources of plant foods. Now when the world was cleft in twain by the shock of August, 1914, the Allied Powers had the nitrates and the Central Powers had the potash. If Germany had not had up her sleeve a new process for making nitrates she could not long have carried on a war and doubtless would not have ventured upon it. But the outside world had no such substitute for the German potash salts and has not yet discovered one. Consequently the price of potash in the United States jumped from $40 to $400 and the cost of food went up with it. Even under the stimulus of prices ten times the normal and with chemists searching furnace crannies and bad lands the United States was able to scrape up less than 10,000 tons of potash in 1916, and this was barely enough to satisfy our needs for two weeks! [Illustration: What happened to potash when the war broke out. This diagram from the _Journal of Industrial and Engineering Chemistry_ of July, 1917, shows how the supply of potassium muriate from Germany was shut off in 1914 and how its price rose.] Yet potash compounds are as cheap as dirt. Pick up a handful of gravel and you will be able to find much of it feldspar or other mineral containing some ten per cent. of potash. Unfortunately it is in combination with silica, which is harder to break up than a trust. But "constant washing wears away stones" and the potash that the metallurgist finds too hard to extract in his hottest furnace is washed out in the course of time through the dropping of the gentle rain from heaven. "All rivers run to the sea" and so the sea gets salt, all sorts of salts, principally sodium chloride (our table salt) and next magnesium, calcium and potassium chlorides or sulfates in this order of abundance. But if we evaporate sea-water down to dryness all these are left in a mix together and it is hard to sort them out. Only patient Nature has time for it and she only did on a large scale in one place, that is at Stassfurt, Germany. It seems that in the days when northwestern Prussia was undetermined whether it should be sea or land it was flooded annually by sea-water. As this slowly evaporated the dissolved salts crystallized out at the critical points, leaving beds of various combinations. Each year there would be deposited three to five inches of salts with a thin layer of calcium sulfate or gypsum on top. Counting these annual layers, like the rings on a stump, we find that the Stassfurt beds were ten thousand years in the making. They were first worked for their salt, common salt, alone, but in 1837 the Prussian Government began prospecting for new and deeper deposits and found, not the clean rock salt that they wanted, but bittern, largely magnesium sulfate or Epsom salt, which is not at all nice for table use. This stuff was first thrown away until it was realized that it was much more valuable for the potash it contains than was the rock salt they were after. Then the Germans began to purify the Stassfurt salts and market them throughout the world. They contain from fifteen to twenty-five per cent. of magnesium chloride mixed with magnesium chloride in "carnallite," with magnesium sulfate in "kainite" and sodium chloride in "sylvinite." More than thirty thousand miners and workmen are employed in the Stassfurt works. There are some seventy distinct establishments engaged in the business, but they are in combination. In fact they are compelled to be, for the German Government is as anxious to promote trusts as the American Government is to prevent them. Once the Stassfurt firms had a falling out and began a cutthroat competition. But the German Government objects to its people cutting each other's throats. American dealers were getting unheard of bargains when the German Government stepped in and compelled the competing corporations to recombine under threat of putting on an export duty that would eat up their profits. The advantages of such business coöperation are specially shown in opening up a new market for an unknown product as in the case of the introduction of the Stassfurt salts into American agriculture. The farmer in any country is apt to be set in his ways and when it comes to inducing him to spend his hard-earned money for chemicals that he never heard of and could not pronounce he--quite rightly--has to be shown. Well, he was shown. It was, if I remember right, early in the nineties that the German Kali Syndikat began operations in America and the United States Government became its chief advertising agent. In every state there was an agricultural experiment station and these were provided liberally with illustrated literature on Stassfurt salts with colored wall charts and sets of samples and free sacks of salts for field experiments. The station men, finding that they could rely upon the scientific accuracy of the information supplied by Kali and that the experiments worked out well, became enthusiastic advocates of potash fertilizers. The station bulletins--which Uncle Sam was kind enough to carry free to all the farmers of the state--sometimes were worded so like the Kali Company advertising that the company might have raised a complaint of plagiarizing, but they never did. The Chilean nitrates, which are under British control, were later introduced by similar methods through the agency of the state agricultural experiment stations. As a result of all this missionary work, which cost the Kali Company $50,000 a year, the attention of a large proportion of American farmers was turned toward intensive farming and they began to realize the necessity of feeding the soil that was feeding them. They grew dependent upon these two foreign and widely separated sources of supply. In the year before the war the United States imported a million tons of Stassfurt salts, for which the farmers paid more than $20,000,000. Then a declaration of American independence--the German embargo of 1915--cut us off from Stassfurt and for five years we had to rely upon our own resources. We have seen how Germany--shut off from Chile--solved the nitrogen problem for her fields and munition plants. It was not so easy for us--shut off from Germany--to solve the potash problem. There is no more lack of potash in the rocks than there is of nitrogen in the air, but the nitrogen is free and has only to be caught and combined, while the potash is shut up in a granite prison from which it is hard to get it free. It is not the percentage in the soil but the percentage in the soil water that counts. A farmer with his potash locked up in silicates is like the merchant who has left the key of his safe at home in his other trousers. He may be solvent, but he cannot meet a sight draft. It is only solvent potash that passes current. In the days of our grandfathers we had not only national independence but household independence. Every homestead had its own potash plant and soap factory. The frugal housewife dumped the maple wood ashes of the fireplace into a hollow log set up on end in the backyard. Water poured over the ashes leached out the lye, which drained into a bucket beneath. This gave her a solution of pearl ash or potassium carbonate whose concentration she tested with an egg as a hydrometer. In the meantime she had been saving up all the waste grease from the frying pan and pork rinds from the plate and by trying out these she got her soap fat. Then on a day set apart for this disagreeable process in chemical technology she boiled the fat and the lye together and got "soft soap," or as the chemist would call it, potassium stearate. If she wanted hard soap she "salted it out" with brine. The sodium stearate being less soluble was precipitated to the top and cooled into a solid cake that could be cut into bars by pack thread. But the frugal housewife threw away in the waste water what we now consider the most valuable ingredients, the potash and the glycerin. But the old lye-leach is only to be found in ruins on an abandoned farm and we no longer burn wood at the rate of a log a night. In 1916 even under the stimulus of tenfold prices the amount of potash produced as pearl ash was only 412 tons--and we need 300,000 tons in some form. It would, of course, be very desirable as a conservation measure if all the sawdust and waste wood were utilized by charring it in retorts. The gas makes a handy fuel. The tar washed from the gas contains a lot of valuable products. And potash can be leached out of the charcoal or from its ashes whenever it is burned. But this at best would not go far toward solving the problem of our national supply. There are other potash-bearing wastes that might be utilized. The cement mills which use feldspar in combination with limestone give off a potash dust, very much to the annoyance of their neighbors. This can be collected by running the furnace clouds into large settling chambers or long flues, where the dust may be caught in bags, or washed out by water sprays or thrown down by electricity. The blast furnaces for iron also throw off potash-bearing fumes. Our six-million-ton crop of sugar beets contains some 12,000 tons of nitrogen, 4000 tons of phosphoric acid and 18,000 tons of potash, all of which is lost except where the waste liquors from the sugar factory are used in irrigating the beet land. The beet molasses, after extracting all the sugar possible by means of lime, leaves a waste liquor from which the potash can be recovered by evaporation and charring and leaching the residue. The Germans get 5000 tons of potassium cyanide and as much ammonium sulfate annually from the waste liquor of their beet sugar factories and if it pays them to save this it ought to pay us where potash is dearer. Various other industries can put in a bit when Uncle Sam passes around the contribution basket marked "Potash for the Poor." Wool wastes and fish refuse make valuable fertilizers, although they will not go far toward solving the problem. If we saved all our potash by-products they would not supply more than fifteen per cent. of our needs. Though no potash beds comparable to those of Stassfurt have yet been discovered in the United States, yet in Nebraska, Utah, California and other western states there are a number of alkali lakes, wet or dry, containing a considerable amount of potash mixed with soda salts. Of these deposits the largest is Searles Lake, California. Here there are some twelve square miles of salt crust some seventy feet deep and the brine as pumped out contains about four per cent. of potassium chloride. The quantity is sufficient to supply the country for over twenty years, but it is not an easy or cheap job to separate the potassium from the sodium salts which are five times more abundant. These being less soluble than the potassium salts crystallize out first when the brine is evaporated. The final crystallization is done in vacuum pans as in getting sugar from the cane juice. In this way the American Trona Corporation is producing some 4500 tons of potash salts a month besides a thousand tons of borax. The borax which is contained in the brine to the extent of 1-1/2 per cent. is removed from the fertilizer for a double reason. It is salable by itself and it is detrimental to plant life. Another mineral source of potash is alunite, which is a sort of natural alum, or double sulfate of potassium and aluminum, with about ten per cent. of potash. It contains a lot of extra alumina, but after roasting in a kiln the potassium sulfate can be leached out. The alunite beds near Marysville, Utah, were worked for all they were worth during the war, but the process does not give potash cheap enough for our needs in ordinary times. [Illustration: Photo by International Film Service IN ORDER TO SECURE A NEW SUPPLY OF POTASH SALTS The United States Government set up an experimental plant at Sutherland, California, for the utilization of kelp. The harvester cuts 40 tons of kelp at a load] [Illustration: THE KELP HARVESTER GATHERING THE SEAWEED FROM THE PACIFIC OCEAN] [Illustration: Courtesy of Hercules Powder Co. OVERHEAD SUCTION AT THE SAN DIEGO WHARF PUMPING KELP FROM THE BARGE TO THE DIGESTION TANKS] The tourist going through Wyoming on the Union Pacific will have to the north of him what is marked on the map as the "Leucite Hills." If he looks up the word in the Unabridged that he carries in his satchel he will find that leucite is a kind of lava and that it contains potash. But he will also observe that the potash is combined with alumina and silica, which are hard to get out and useless when you get them out. One of the lavas of the Leucite Hills, that named from its native state "Wyomingite," gives fifty-seven per cent. of its potash in a soluble form on roasting with alunite--but this costs too much. The same may be said of all the potash feldspars and mica. They are abundant enough, but until we find a way of utilizing the by-products, say the silica in cement and the aluminum as a metal, they cannot solve our problem. Since it is so hard to get potash from the land it has been suggested that we harvest the sea. The experts of the United States Department of Agriculture have placed high hopes in the kelp or giant seaweed which floats in great masses in the Pacific Ocean not far off from the California coast. This is harvested with ocean reapers run by gasoline engines and brought in barges to the shore, where it may be dried and used locally as a fertilizer or burned and the potassium chloride leached out of the charcoal ashes. But it is hard to handle the bulky, slimy seaweed cheaply enough to get out of it the small amount of potash it contains. So efforts are now being made to get more out of the kelp than the potash. Instead of burning the seaweed it is fermented in vats producing acetic acid (vinegar). From the resulting liquid can be obtained lime acetate, potassium chloride, potassium iodide, acetone, ethyl acetate (used as a solvent for guncotton) and algin, a gelatin-like gum. PRODUCTION OF POTASH IN THE UNITED STATES __________________________________________________________________________ | | | 1916 | 1917 Source | Tons K_{2}O | Per cent. | Tons K_{2}O | Per cent. | | of total | | of total | | production | | production ____________________|_____________|____________|_____________|____________ | | | | Mineral sources: | | | | Natural brines | 3,994 | 41.1 | 20,652 | 63.4 Altmite | 1,850 | 19.0 | 2,402 | 7.3 Dust from cement | | | | mills | | | 1,621 | 5.0 Dust from blast | | | | furnaces | | | 185 | 0.6 Organic Sources: | | | | Kelp | 1,556 | 16.0 | 3,752 | 10.9 Molasses residue | | | | from distillers | 1,845 | 19.0 | 2,846 | 8.8 Wood ashes | 412 | 4.2 | 621 | 1.9 Waste liquors | | | | from beet-sugar | | | | refineries | | | 369 | 1.1 Miscellaneous | | | | industrial | | | | wastes | 63 | .7 | 305 | 1.0 | ___________ | __________ | ___________ | __________ | | | | Total | 9,720 | 100.0 | 32,573 | 100.0 --From U S. Bureau of Mines Report, 1918. This table shows how inadequate was the reaction of the United States to the war demand for potassium salts. The minimum yearly requirements of the United States are estimated to be 250,000 tons of potash. This completes our survey of the visible sources of potash in America. In 1917 under the pressure of the embargo and unprecedented prices the output of potash (K_{2}O) in various forms was raised to 32,573 tons, but this is only about a tenth as much as we needed. In 1918 potash production was further raised to 52,135 tons, chiefly through the increase of the output from natural brines to 39,255 tons, nearly twice what it was the year before. The rust in cotton and the resulting decrease in yield during the war are laid to lack of potash. Truck crops grown in soils deficient in potash do not stand transportation well. The Bureau of Animal Industry has shown in experiments in Aroostook County, Maine, that the addition of moderate amounts of potash doubled the yield of potatoes. Professor Ostwald, the great Leipzig chemist, boasted in the war: America went into the war like a man with a rope round his neck which is in his enemy's hands and is pretty tightly drawn. With its tremendous deposits Germany has a world monopoly in potash, a point of immense value which cannot be reckoned too highly when once this war is going to be settled. It is in Germany's power to dictate which of the nations shall have plenty of food and which shall starve. If, indeed, some mineralogist or metallurgist will cut that rope by showing us a supply of cheap potash we will erect him a monument as big as Washington's. But Ostwald is wrong in supposing that America is as dependent as Germany upon potash. The bulk of our food crops are at present raised without the use of any fertilizers whatever. As the cession of Lorraine in 1871 gave Germany the phosphates she needed for fertilizers so the retrocession of Alsace in 1919 gives France the potash she needed for fertilizers. Ten years before the war a bed of potash was discovered in the Forest of Monnebruck, near Hartmannsweilerkopf, the peak for which French and Germans contested so fiercely and so long. The layer of potassium salts is 16-1/2 feet thick and the total deposit is estimated to be 275,000,000 tons of potash. At any rate it is a formidable rival of Stassfurt and its acquisition by France breaks the German monopoly. When we turn to the consideration of the third plant food we feel better. While the United States has no such monopoly of phosphates as Germany had of potash and Chile had of nitrates we have an abundance and to spare. Whereas we formerly _imported_ about $17,000,000 worth of potash from Germany and $20,000,000 worth of nitrates from Chile a year we _exported_ $7,000,000 worth of phosphates. Whoever it was who first noticed that the grass grew thicker around a buried bone he lived so long ago that we cannot do honor to his powers of observation, but ever since then--whenever it was--old bones have been used as a fertilizer. But we long ago used up all the buffalo bones we could find on the prairies and our packing houses could not give us enough bone-meal to go around, so we have had to draw upon the old bone-yards of prehistoric animals. Deposits of lime phosphate of such origin were found in South Carolina in 1870 and in Florida in 1888. Since then the industry has developed with amazing rapidity until in 1913 the United States produced over three million tons of phosphates, nearly half of which was sent abroad. The chief source at present is the Florida pebbles, which are dredged up from the bottoms of lakes and rivers or washed out from the banks of streams by a hydraulic jet. The gravel is washed free from the sand and clay, screened and dried, and then is ready for shipment. The rock deposits of Florida and South Carolina are more limited than the pebble beds and may be exhausted in twenty-five or thirty years, but Tennessee and Kentucky have a lot in reserve and behind them are Idaho, Wyoming and other western states with millions of acres of phosphate land, so in this respect we are independent. But even here the war hit us hard. For the calcium phosphate as it comes from the ground is not altogether available because it is not very soluble and the plants can only use what they can get in the water that they suck up from the soil. But if the phosphate is treated with sulfuric acid it becomes more soluble and this product is sold as "superphosphate." The sulfuric acid is made mostly from iron pyrite and this we have been content to import, over 800,000 tons of it a year, largely from Spain, although we have an abundance at home. Since the shortage of shipping shut off the foreign supply we are using more of our own pyrite and also our deposits of native sulfur along the Gulf coast. But as a consequence of this sulfuric acid during the war went up from $5 to $25 a ton and acidulated phosphates rose correspondingly. Germany is short on natural phosphates as she is long on natural potash. But she has made up for it by utilizing a by-product of her steelworks. When phosphorus occurs in iron ore, even in minute amounts, it makes the steel brittle. Much of the iron ores of Alsace-Lorraine were formerly considered unworkable because of this impurity, but shortly after Germany took these provinces from France in 1871 a method was discovered by two British metallurgists, Thomas and Gilchrist, by which the phosphorus is removed from the iron in the process of converting it into steel. This consists in lining the crucible or converter with lime and magnesia, which takes up the phosphorus from the melted iron. This slag lining, now rich in phosphates, can be taken out and ground up for fertilizer. So the phosphorus which used to be a detriment is now an additional source of profit and this British invention has enabled Germany to make use of the territory she stole from France to outstrip England in the steel business. In 1910 Germany produced 2,000,000 tons of Thomas slag while only 160,000 tons were produced in the United Kingdom. The open hearth process now chiefly used in the United States gives an acid instead of a basic phosphate slag, not suitable as a fertilizer. The iron ore of America, with the exception of some of the southern ores, carries so small a percentage of phosphorus as to make a basic process inadvisable. Recently the Germans have been experimenting with a combined fertilizer, Schröder's potassium phosphate, which is said to be as good as Thomas slag for phosphates and as good as Stassfurt salts for potash. The American Cyanamid Company is just putting out a similar product, "Ammo-Phos," in which the ammonia can be varied from thirteen to twenty per cent. and the phosphoric acid from twenty to forty-seven per cent. so as to give the proportions desired for any crop. We have then the possibility of getting the three essential plant foods altogether in one compound with the elimination of most of the extraneous elements such as lime and magnesia, chlorids and sulfates. For the last three hundred years the American people have been living on the unearned increment of the unoccupied land. But now that all our land has been staked out in homesteads and we cannot turn to new soil when we have used up the old, we must learn, as the older races have learned, how to keep up the supply of plant food. Only in this way can our population increase and prosper. As we have seen, the phosphate question need not bother us and we can see our way clear toward solving the nitrate question. We gave the Government $20,000,000 to experiment on the production of nitrates from the air and the results will serve for fields as well as firearms. But the question of an independent supply of cheap potash is still unsolved. IV COAL-TAR COLORS If you put a bit of soft coal into a test tube (or, if you haven't a test tube, into a clay tobacco pipe and lute it over with clay) and heat it you will find a gas coming out of the end of the tube that will burn with a yellow smoky flame. After all the gas comes off you will find in the bottom of the test tube a chunk of dry, porous coke. These, then, are the two main products of the destructive distillation of coal. But if you are an unusually observant person, that is, if you are a born chemist with an eye to by-products, you will notice along in the middle of the tube where it is neither too hot nor too cold some dirty drops of water and some black sticky stuff. If you are just an ordinary person, you won't pay any attention to this because there is only a little of it and because what you are after is the coke and gas. You regard the nasty, smelly mess that comes in between as merely a nuisance because it clogs up and spoils your nice, clean tube. Now that is the way the gas-makers and coke-makers--being for the most part ordinary persons and not born chemists--used to regard the water and tar that got into their pipes. They washed it out so as to have the gas clean and then ran it into the creek. But the neighbors--especially those who fished in the stream below the gas-works--made a fuss about spoiling the water, so the gas-men gave away the tar to the boys for use in celebrating the Fourth of July and election night or sold it for roofing. [Illustration: THE PRODUCTION OF COAL TAR A battery of Koppers by-product coke-ovens at the plant of the Bethlehem Steel Company, Sparrows Point, Maryland. The coke is being pushed out of one of the ovens into the waiting car. The vapors given off from the coal contain ammonia and the benzene compound used to make dyes and explosives] [Illustration: IN THESE MIXING VATS AT THE BUFFALO WORKS, ANILINE DYES ARE PREPARED] But this same tar, which for a hundred years was thrown away and nearly half of which is thrown away yet in the United States, turns out to be one of the most useful things in the world. It is one of the strategic points in war and commerce. It wounds and heals. It supplies munitions and medicines. It is like the magic purse of Fortunatus from which anything wished for could be drawn. The chemist puts his hand into the black mass and draws out all the colors of the rainbow. This evil-smelling substance beats the rose in the production of perfume and surpasses the honey-comb in sweetness. Bishop Berkeley, after having proved that all matter was in your mind, wrote a book to prove that wood tar would cure all diseases. Nobody reads it now. The name is enough to frighten them off: "Siris: A Chain of Philosophical Reflections and Inquiries Concerning the Virtues of Tar Water." He had a sort of mystical idea that tar contained the quintessence of the forest, the purified spirit of the trees, which could somehow revive the spirit of man. People said he was crazy on the subject, and doubtless he was, but the interesting thing about it is that not even his active and ingenious imagination could begin to suggest all of the strange things that can be got out of tar, whether wood or coal. The reason why tar supplies all sorts of useful material is because it is indeed the quintessence of the forest, of the forests of untold millenniums if it is coal tar. If you are acquainted with a village tinker, one of those all-round mechanics who still survive in this age of specialization and can mend anything from a baby-carriage to an automobile, you will know that he has on the floor of his back shop a heap of broken machinery from which he can get almost anything he wants, a copper wire, a zinc plate, a brass screw or a steel rod. Now coal tar is the scrap-heap of the vegetable kingdom. It contains a little of almost everything that makes up trees. But you must not imagine that all that comes out of coal tar is contained in it. There are only about a dozen primary products extracted from coal tar, but from these the chemist is able to build up hundreds of thousands of new substances. This is true creative chemistry, for most of these compounds are not to be found in plants and never existed before they were made in the laboratory. It used to be thought that organic compounds, the products of vegetable and animal life, could only be produced by organized beings, that they were created out of inorganic matter by the magic touch of some "vital principle." But since the chemist has learned how, he finds it easier to make organic than inorganic substances and he is confident that he can reproduce any compound that he can analyze. He cannot only imitate the manufacturing processes of the plants and animals, but he can often beat them at their own game. When coal is heated in the open air it is burned up and nothing but the ashes is left. But heat the coal in an enclosed vessel, say a big fireclay retort, and it cannot burn up because the oxygen of the air cannot get to it. So it breaks up. All parts of it that can be volatized at a high heat pass off through the outlet pipe and nothing is left in the retort but coke, that is carbon with the ash it contains. When the escaping vapors reach a cool part of the outlet pipe the oily and tarry matter condenses out. Then the gas is passed up through a tower down which water spray is falling and thus is washed free from ammonia and everything else that is soluble in water. This process is called "destructive distillation." What products come off depends not only upon the composition of the particular variety of coal used, but upon the heat, pressure and rapidity of distillation. The way you run it depends upon what you are most anxious to have. If you want illuminating gas you will leave in it the benzene. If you are after the greatest yield of tar products, you impoverish the gas by taking out the benzene and get a blue instead of a bright yellow flame. If all you are after is cheap coke, you do not bother about the by-products, but let them escape and burn as they please. The tourist passing across the coal region at night could see through his car window the flames of hundreds of old-fashioned bee-hive coke-ovens and if he were of economical mind he might reflect that this display of fireworks was costing the country $75,000,000 a year besides consuming the irreplaceable fuel supply of the future. But since the gas was not needed outside of the cities and since the coal tar, if it could be sold at all, brought only a cent or two a gallon, how could the coke-makers be expected to throw out their old bee-hive ovens and put in the expensive retorts and towers necessary to the recovery of the by-products? But within the last ten years the by-product ovens have come into use and now nearly half our coke is made in them. Although the products of destructive distillation vary within wide limits, yet the following table may serve to give an approximate idea of what may be got from a ton of soft coal: 1 ton of coal may give Gas, 12,000 cubic feet Liquor (Washings) ammonium sulfate (7-25 pounds) Tar (120 pounds) benzene (10-20 pounds) toluene (3 pounds) xylene (1-1/2 pounds) phenol (1/2 pound) naphthalene (3/8 pound) anthracene (1/4 pound) pitch (80 pounds) Coke (1200-1500 pounds) When the tar is redistilled we get, among other things, the ten "crudes" which are fundamental material for making dyes. Their names are: benzene, toluene, xylene, phenol, cresol, naphthalene, anthracene, methyl anthracene, phenanthrene and carbazol. There! I had to introduce you to the whole receiving line, but now that that ceremony is over we are at liberty to do as we do at a reception, meet our old friends, get acquainted with one or two more and turn our backs on the rest. Two of them, I am sure, you've met before, phenol, which is common carbolic acid, and naphthalene, which we use for mothballs. But notice one thing in passing, that not one of them is a dye. They are all colorless liquids or white solids. Also they all have an indescribable odor--all odors that you don't know are indescribable--which gives them and their progeny, even when odorless, the name of "aromatic compounds." [Illustration: Fig. 8. Diagram of the products obtained from coal and some of their uses.] The most important of the ten because he is the father of the family is benzene, otherwise called benzol, but must not be confused with "benzine" spelled with an _i_ which we used to burn and clean our clothes with. "Benzine" is a kind of gasoline, but benzene _alias_ benzol has quite another constitution, although it looks and burns the same. Now the search for the constitution of benzene is one of the most exciting chapters in chemistry; also one of the most intricate chapters, but, in spite of that, I believe I can make the main point of it clear even to those who have never studied chemistry--provided they retain their childish liking for puzzles. It is really much like putting together the old six-block Chinese puzzle. The chemist can work better if he has a picture of what he is working with. Now his unit is the molecule, which is too small even to analyze with the microscope, no matter how high powered. So he makes up a sort of diagram of the molecule, and since he knows the number of atoms and that they are somehow attached to one another, he represents each atom by the first letter of its name and the points of attachment or bonds by straight lines connecting the atoms of the different elements. Now it is one of the rules of the game that all the bonds must be connected or hooked up with atoms at both ends, that there shall be no free hands reaching out into empty space. Carbon, for instance, has four bonds and hydrogen only one. They unite, therefore, in the proportion of one atom of carbon to four of hydrogen, or CH_{4}, which is methane or marsh gas and obviously the simplest of the hydrocarbons. But we have more complex hydrocarbons such as C_{6}H_{14}, known as hexane. Now if you try to draw the diagrams or structural formulas of these two compounds you will easily get H H H H H H H | | | | | | | H-C-H H-C-C-C-C-C-C-H | | | | | | | H H H H H H H methane hexane Each carbon atom, you see, has its four hands outstretched and duly grasped by one-handed hydrogen atoms or by neighboring carbon atoms in the chain. We can have such chains as long as you please, thirty or more in a chain; they are all contained in kerosene and paraffin. So far the chemist found it east to construct diagrams that would satisfy his sense of the fitness of things, but when he found that benzene had the compostion C_{6}H_{6} he was puzzled. If you try to draw the picture of C_{6}H_{6} you will get something like this: | | | | | | -C-C-C-C-C-C- | | | | | | H H H H H H which is an absurdity because more than half of the carbon hands are waving wildly around asking to be held by something. Benzene, C_{6}H_{6}, evidently is like hexane, C_{6}H_{14}, in having a chain of six carbon atoms, but it has dropped its H's like an Englishman. Eight of the H's are missing. Now one of the men who was worried over this benzene puzzle was the German chemist, Kekulé. One evening after working over the problem all day he was sitting by the fire trying to rest, but he could not throw it off his mind. The carbon and the hydrogen atoms danced like imps on the carpet and as he watched them through his half-closed eyes he suddenly saw that the chain of six carbon atoms had joined at the ends and formed a ring while the six hydrogen atoms were holding on to the outside hands, in this fashion: H | C / \\ H-C C-H || | H-C C-H \ // C | H Professor Kekulé saw at once that the demons of his subconscious self had furnished him with a clue to the labyrinth, and so it proved. We need not suppose that the benzene molecule if we could see it would look anything like this diagram of it, but the theory works and that is all the scientist asks of any theory. By its use thousands of new compounds have been constructed which have proved of inestimable value to man. The modern chemist is not a discoverer, he is an inventor. He sits down at his desk and draws a "Kekulé ring" or rather hexagon. Then he rubs out an H and hooks a nitro group (NO_{2}) on to the carbon in place of it; next he rubs out the O_{2} of the nitro group and puts in H_{2}; then he hitches on such other elements, or carbon chains and rings as he likes. He works like an architect designing a house and when he gets a picture of the proposed compounds to suit him he goes into the laboratory to make it. First he takes down the bottle of benzene and boils up some of this with nitric acid and sulfuric acid. This he puts in the nitro group and makes nitro-benzene, C_{6}H_{5}NO_{2}. He treats this with hydrogen, which displaces the oxygen and gives C_{6}H_{5}NH_{2} or aniline, which is the basis of so many of these compounds that they are all commonly called "the aniline dyes." But aniline itself is not a dye. It is a colorless or brownish oil. It is not necessary to follow our chemist any farther now that we have seen how he works, but before we pass on we will just look at one of his products, not one of the most complicated but still complicated enough. [Illustration: A molecule of a coal-tar dye] The name of this is sodium ditolyl-disazo-beta-naphthylamine- 6-sulfonic-beta-naphthylamine-3.6-disulfonate. These chemical names of organic compounds are discouraging to the beginner and amusing to the layman, but that is because neither of them realizes that they are not really words but formulas. They are hyphenated because they come from Germany. The name given above is no more of a mouthful than "a-square-plus-two-a-b-plus-b-square" or "Third Assistant Secretary of War to the President of the United States of America." The trade name of this dye is Brilliant Congo, but while that is handier to say it does not mean anything. Nobody but an expert in dyes would know what it was, while from the formula name any chemist familiar with such compounds could draw its picture, tell how it would behave and what it was made from, or even make it. The old alchemist was a secretive and pretentious person and used to invent queer names for the purpose of mystifying and awing the ignorant. But the chemist in dropping the al- has dropped the idea of secrecy and his names, though equally appalling to the layman, are designed to reveal and not to conceal. From this brief explanation the reader who has not studied chemistry will, I think, be able to get some idea of how these very intricate compounds are built up step by step. A completed house is hard to understand, but when we see the mason laying one brick on top of another it does not seem so difficult, although if we tried to do it we should not find it so easy as we think. Anyhow, let me give you a hint. If you want to make a good impression on a chemist don't tell him that he seems to you a sort of magician, master of a black art, and all that nonsense. The chemist has been trying for three hundred years to live down the reputation of being inspired of the devil and it makes him mad to have his past thrown up at him in this fashion. If his tactless admirers would stop saying "it is all a mystery and a miracle to me, and I cannot understand it" and pay attention to what he is telling them they would understand it and would find that it is no more of a mystery or a miracle than anything else. You can make an electrician mad in the same way by interrupting his explanation of a dynamo by asking: "But you cannot tell me what electricity really is." The electrician does not care a rap what electricity "really is"--if there really is any meaning to that phrase. All he wants to know is what he can do with it. [Illustration: COMPARISON OF COAL AND ITS DISTILLATION PRODUCTS From Hesse's "The Industry of the Coal Tar Dyes," _Journal of Industrial and Engineering Chemistry_, December, 1914] The tar obtained from the gas plant or the coke plant has now to be redistilled, giving off the ten "crudes" already mentioned and leaving in the still sixty-five per cent. of pitch, which may be used for roofing, paving and the like. The ten primary products or crudes are then converted into secondary products or "intermediates" by processes like that for the conversion of benzene into aniline. There are some three hundred of these intermediates in use and from them are built up more than three times as many dyes. The year before the war the American custom house listed 5674 distinct brands of synthetic dyes imported, chiefly from Germany, but some of these were trade names for the same product made by different firms or represented by different degrees of purity or form of preparation. Although the number of possible products is unlimited and over five thousand dyes are known, yet only about nine hundred are in use. We can summarize the situation so: Coal-tar --> 10 crudes --> 300 intermediates --> 900 dyes --> 5000 brands. Or, to borrow the neat simile used by Dr. Bernhard C. Hesse, it is like cloth-making where "ten fibers make 300 yarns which are woven into 900 patterns." The advantage of the artificial dyestuffs over those found in nature lies in their variety and adaptability. Practically any desired tint or shade can be made for any particular fabric. If my lady wants a new kind of green for her stockings or her hair she can have it. Candies and jellies and drinks can be made more attractive and therefore more appetizing by varied colors. Easter eggs and Easter bonnets take on new and brighter hues. More and more the chemist is becoming the architect of his own fortunes. He does not make discoveries by picking up a beaker and pouring into it a little from each bottle on the shelf to see what happens. He generally knows what he is after, and he generally gets it, although he is still often baffled and occasionally happens on something quite unexpected and perhaps more valuable than what he was looking for. Columbus was looking for India when he ran into an obstacle that proved to be America. William Henry Perkin was looking for quinine when he blundered into that rich and undiscovered country, the aniline dyes. William Henry was a queer boy. He had rather listen to a chemistry lecture than eat. When he was attending the City of London School at the age of thirteen there was an extra course of lectures on chemistry given at the noon recess, so he skipped his lunch to take them in. Hearing that a German chemist named Hofmann had opened a laboratory in the Royal College of London he headed for that. Hofmann obviously had no fear of forcing the young intellect prematurely. He perhaps had never heard that "the tender petals of the adolescent mind must be allowed to open slowly." He admitted young Perkin at the age of fifteen and started him on research at the end of his second year. An American student nowadays thinks he is lucky if he gets started on his research five years older than Perkin. Now if Hofmann had studied pedagogical psychology he would have been informed that nothing chills the ardor of the adolescent mind like being set at tasks too great for its powers. If he had heard this and believed it, he would not have allowed Perkin to spend two years in fruitless endeavors to isolate phenanthrene from coal tar and to prepare artificial quinine--and in that case Perkin would never have discovered the aniline dyes. But Perkin, so far from being discouraged, set up a private laboratory so he could work over-time. While working here during the Easter vacation of 1856--the date is as well worth remembering as 1066--he was oxidizing some aniline oil when he got what chemists most detest, a black, tarry mass instead of nice, clean crystals. When he went to wash this out with alcohol he was surprised to find that it gave a beautiful purple solution. This was "mauve," the first of the aniline dyes. The funny thing about it was that when Perkin tried to repeat the experiment with purer aniline he could not get his color. It was because he was working with impure chemicals, with aniline containing a little toluidine, that he discovered mauve. It was, as I said, a lucky accident. But it was not accidental that the accident happened to the young fellow who spent his noonings and vacations at the study of chemistry. A man may not find what he is looking for, but he never finds anything unless he is looking for something. Mauve was a product of creative chemistry, for it was a substance that had never existed before. Perkin's next great triumph, ten years later, was in rivaling Nature in the manufacture of one of her own choice products. This is alizarin, the coloring matter contained in the madder root. It was an ancient and oriental dyestuff, known as "Turkey red" or by its Arabic name of "alizari." When madder was introduced into France it became a profitable crop and at one time half a million tons a year were raised. A couple of French chemists, Robiquet and Colin, extracted from madder its active principle, alizarin, in 1828, but it was not until forty years later that it was discovered that alizarin had for its base one of the coal-tar products, anthracene. Then came a neck-and-neck race between Perkin and his German rivals to see which could discover a cheap process for making alizarin from anthracene. The German chemists beat him to the patent office by one day! Graebe and Liebermann filed their application for a patent on the sulfuric acid process as No. 1936 on June 25, 1869. Perkin filed his for the same process as No. 1948 on June 26. It had required twenty years to determine the constitution of alizarin, but within six months from its first synthesis the commercial process was developed and within a few years the sale of artificial alizarin reached $8,000,000 annually. The madder fields of France were put to other uses and even the French soldiers became dependent on made-in-Germany dyes for their red trousers. The British soldiers were placed in a similar situation as regards their red coats when after 1878 the azo scarlets put the cochineal bug out of business. The modern chemist has robbed royalty of its most distinctive insignia, Tyrian purple. In ancient times to be "porphyrogene," that is "born to the purple," was like admission to the Almanach de Gotha at the present time, for only princes or their wealthy rivals could afford to pay $600 a pound for crimsoned linen. The precious dye is secreted by a snail-like shellfish of the eastern coast of the Mediterranean. From a tiny sac behind the head a drop of thick whitish liquid, smelling like garlic, can be extracted. If this is spread upon cloth of any kind and exposed to air and sunlight it turns first green, next blue and then purple. If the cloth is washed with soap--that is, set by alkali--it becomes a fast crimson, such as Catholic cardinals still wear as princes of the church. The Phoenician merchants made fortunes out of their monopoly, but after the fall of Tyre it became one of "the lost arts"--and accordingly considered by those whose faces are set toward the past as much more wonderful than any of the new arts. But in 1909 Friedlander put an end to the superstition by analyzing Tyrian purple and finding that it was already known. It was the same as a dye that had been prepared five years before by Sachs but had not come into commercial use because of its inferiority to others in the market. It required 12,000 of the mollusks to supply the little material needed for analysis, but once the chemist had identified it he did not need to bother the Murex further, for he could make it by the ton if he had wanted to. The coloring principle turned out to be a di-brom indigo, that is the same as the substance extracted from the Indian plant, but with the addition of two atoms of bromine. Why a particular kind of a shellfish should have got the habit of extracting this rare element from sea water and stowing it away in this peculiar form is "one of those things no fellow can find out." But according to the chemist the Murex mollusk made a mistake in hitching the bromine to the wrong carbon atoms. He finds as he would word it that the 6:6' di-brom indigo secreted by the shellfish is not so good as the 5:5' di-brom indigo now manufactured at a cheap rate and in unlimited quantity. But we must not expect too much of a mollusk's mind. In their cheapness lies the offense of the aniline dyes in the minds of some people. Our modern aristocrats would delight to be entitled "porphyrogeniti" and to wear exclusive gowns of "purple and scarlet from the isles of Elishah" as was done in Ezekiel's time, but when any shopgirl or sailor can wear the royal color it spoils its beauty in their eyes. Applied science accomplishes a real democracy such as legislation has ever failed to establish. Any kind of dye found in nature can be made in the laboratory whenever its composition is understood and usually it can be made cheaper and purer than it can be extracted from the plant. But to work out a profitable process for making it synthetically is sometimes a task requiring high skill, persistent labor and heavy expenditure. One of the latest and most striking of these achievements of synthetic chemistry is the manufacture of indigo. Indigo is one of the oldest and fastest of the dyestuffs. To see that it is both ancient and lasting look at the unfaded blue cloths that enwrap an Egyptian mummy. When Caesar conquered our British ancestors he found them tattooed with woad, the native indigo. But the chief source of indigo was, as its name implies, India. In 1897 nearly a million acres in India were growing the indigo plant and the annual value of the crop was $20,000,000. Then the fall began and by 1914 India was producing only $300,000 worth! What had happened to destroy this profitable industry? Some blight or insect? No, it was simply that the Badische Anilin-und-Soda Fabrik had worked out a practical process for making artificial indigo. That indigo on breaking up gave off aniline was discovered as early as 1840. In fact that was how aniline got its name, for when Fritzsche distilled indigo with caustic soda he called the colorless distillate "aniline," from the Arabic name for indigo, "anil" or "al-nil," that is, "the blue-stuff." But how to reverse the process and get indigo from aniline puzzled chemists for more than forty years until finally it was solved by Adolf von Baeyer of Munich, who died in 1917 at the age of eighty-four. He worked on the problem of the constitution of indigo for fifteen years and discovered several ways of making it. It is possible to start from benzene, toluene or naphthalene. The first process was the easiest, but if you will refer to the products of the distillation of tar you will find that the amount of toluene produced is less than the naphthalene, which is hard to dispose of. That is, if a dye factory had worked out a process for making indigo from toluene it would not be practicable because there was not enough toluene produced to supply the demand for indigo. So the more complicated napthalene process was chosen in preference to the others in order to utilize this by-product. The Badische Anilin-und-Soda Fabrik spent $5,000,000 and seventeen years in chemical research before they could make indigo, but they gained a monopoly (or, to be exact, ninety-six per cent.) of the world's production. A hundred years ago indigo cost as much as $4 a pound. In 1914 we were paying fifteen cents a pound for it. Even the pauper labor of India could not compete with the German chemists at that price. At the beginning of the present century Germany was paying more than $3,000,000 a year for indigo. Fourteen years later Germany was _selling_ indigo to the amount of $12,600,000. Besides its cheapness, artificial indigo is preferable because it is of uniform quality and greater purity. Vegetable indigo contains from forty to eighty per cent. of impurities, among them various other tinctorial substances. Artificial indigo is made pure and of any desired strength, so the dyers can depend on it. The value of the aniline colors lies in their infinite variety. Some are fast, some will fade, some will stand wear and weather as long as the fabric, some will wash out on the spot. Dyes can be made that will attach themselves to wool, to silk or to cotton, and give it any shade of any color. The period of discovery by accident has long gone by. The chemist nowadays decides first just what kind of a dye he wants, and then goes to work systematically to make it. He begins by drawing a diagram of the molecule, double-linking nitrogen or carbon and oxygen atoms to give the required intensity, putting in acid or basic radicals to fasten it to the fiber, shifting the color back and forth along the spectrum at will by introducing methyl groups, until he gets it just to his liking. Art can go ahead of nature in the dyestuff business. Before man found that he could make all the dyes he wanted from the tar he had been burning up at home he searched the wide world over to find colors by which he could make himself--or his wife--garments as beautiful as those that arrayed the flower, the bird and the butterfly. He sent divers down into the Mediterranean to rob the murex of his purple. He sent ships to the new world to get Brazil wood and to the oldest world for indigo. He robbed the lady cochineal of her scarlet coat. Why these peculiar substances were formed only by these particular plants, mussels and insects it is hard to understand. I don't know that Mrs. Cacti Coccus derived any benefit from her scarlet uniform when khaki would be safer, and I can't imagine that to a shellfish it was of advantage to turn red as it rots or to an indigo plant that its leaves in decomposing should turn blue. But anyhow, it was man that took advantage of them until he learned how to make his own dyestuffs. Our independent ancestors got along so far as possible with what grew in the neighborhood. Sweetapple bark gave a fine saffron yellow. Ribbons were given the hue of the rose by poke berry juice. The Confederates in their butternut-colored uniform were almost as invisible as if in khaki or _feldgrau_. Madder was cultivated in the kitchen garden. Only logwood from Jamaica and indigo from India had to be imported. That we are not so independent today is our own fault, for we waste enough coal tar to supply ourselves and other countries with all the new dyes needed. It is essentially a question of economy and organization. We have forgotten how to economize, but we have learned how to organize. The British Government gave the discoverer of mauve a title, but it did not give him any support in his endeavors to develop the industry, although England led the world in textiles and needed more dyes than any other country. So in 1874 Sir William Perkin relinquished the attempt to manufacture the dyes he had discovered because, as he said, Oxford and Cambridge refused to educate chemists or to carry on research. Their students, trained in the classics for the profession of being a gentleman, showed a decided repugnance to the laboratory on account of its bad smells. So when Hofmann went home he virtually took the infant industry along with him to Germany, where Ph.D.'s were cheap and plentiful and not afraid of bad smells. There the business throve amazingly, and by 1914 the Germans were manufacturing more than three-fourths of all the coal-tar products of the world and supplying material for most of the rest. The British cursed the universities for thus imperiling the nation through their narrowness and neglect; but this accusation, though natural, was not altogether fair, for at least half the blame should go to the British dyer, who did not care where his colors came from, so long as they were cheap. When finally the universities did turn over a new leaf and began to educate chemists, the manufacturers would not employ them. Before the war six English factories producing dyestuffs employed only 35 chemists altogether, while one German color works, the Höchster Farbwerke, employed 307 expert chemists and 74 technologists. This firm united with the six other leading dye companies of Germany on January 1, 1916, to form a trust to last for fifty years. During this time they will maintain uniform prices and uniform wage scales and hours of labor, and exchange patents and secrets. They will divide the foreign business _pro rata_ and share the profits. The German chemical works made big profits during the war, mostly from munitions and medicines, and will be, through this new combination, in a stronger position than ever to push the export trade. As a consequence of letting the dye business get away from her, England found herself in a fix when war broke out. She did not have dyes for her uniforms and flags, and she did not have drugs for her wounded. She could not take advantage of the blockade to capture the German trade in Asia and South America, because she could not color her textiles. A blue cotton dyestuff that sold before the war at sixty cents a pound, brought $34 a pound. A bright pink rhodamine formerly quoted at a dollar a pound jumped to $48. When one keg of dye ordinarily worth $15 was put up at forced auction sale in 1915 it was knocked down at $1500. The Highlanders could not get the colors for their kilts until some German dyes were smuggled into England. The textile industries of Great Britain, that brought in a billion dollars a year and employed one and a half million workers, were crippled for lack of dyes. The demand for high explosives from the front could not be met because these also are largely coal-tar products. Picric acid is both a dye and an explosive. It is made from carbolic acid and the famous trinitrotoluene is made from toluene, both of which you will find in the list of the ten fundamental "crudes." Both Great Britain and the United States realized the danger of allowing Germany to recover her former monopoly, and both have shown a readiness to cast overboard their traditional policies to meet this emergency. The British Government has discovered that a country without a tariff is a land without walls. The American Government has discovered that an industry is not benefited by being cut up into small pieces. Both governments are now doing all they can to build up big concerns and to provide them with protection. The British Government assisted in the formation of a national company for the manufacture of synthetic dyes by taking one-sixth of the stock and providing $500,000 for a research laboratory. But this effort is now reported to be "a great failure" because the Government put it in charge of the politicians instead of the chemists. The United States, like England, had become dependent upon Germany for its dyestuffs. We imported nine-tenths of what we used and most of those that were produced here were made from imported intermediates. When the war broke out there were only seven firms and 528 persons employed in the manufacture of dyes in the United States. One of these, the Schoelkopf Aniline and Chemical Works, of Buffalo, deserves mention, for it had stuck it out ever since 1879, and in 1914 was making 106 dyes. In June, 1917, this firm, with the encouragement of the Government Bureau of Foreign and Domestic Commerce, joined with some of the other American producers to form a trade combination, the National Aniline and Chemical Company. The Du Pont Company also entered the field on an extensive scale and soon there were 118 concerns engaged in it with great profit. During the war $200,000,000 was invested in the domestic dyestuff industry. To protect this industry Congress put on a specific duty of five cents a pound and an ad valorem duty of 30 per cent. on imported dyestuffs; but if, after five years, American manufacturers are not producing 60 per cent. in value of the domestic consumption, the protection is to be removed. For some reason, not clearly understood and therefore hotly discussed, Congress at the last moment struck off the specific duty from two of the most important of the dyestuffs, indigo and alizarin, as well as from all medicinals and flavors. The manufacture of dyes is not a big business, but it is a strategic business. Heligoland is not a big island, but England would have been glad to buy it back during the war at a high price per square yard. American industries employing over two million men and women and producing over three billion dollars' worth of products a year are dependent upon dyes. Chief of these is of course textiles, using more than half the dyes; next come leather, paper, paint and ink. We have been importing more than $12,000,000 worth of coal-tar products a year, but the cottonseed oil we exported in 1912 would alone suffice to pay that bill twice over. But although the manufacture of dyes cannot be called a big business, in comparison with some others, it is a paying business when well managed. The German concerns paid on an average 22 per cent. dividends on their capital and sometimes as high as 50 per cent. Most of the standard dyes have been so long in use that the patents are off and the processes are well enough known. We have the coal tar and we have the chemists, so there seems no good reason why we should not make our own dyes, at least enough of them so we will not be caught napping as we were in 1914. It was decidedly humiliating for our Government to have to beg Germany to sell us enough colors to print our stamps and greenbacks and then have to beg Great Britain for permission to bring them over by Dutch ships. The raw material for the production of coal-tar products we have in abundance if we will only take the trouble to save it. In 1914 the crude light oil collected from the coke-ovens would have produced only about 4,500,000 gallons of benzol and 1,500,000 gallons of toluol, but in 1917 this output was raised to 40,200,000 gallons of benzol and 10,200,000 of toluol. The toluol was used mostly in the manufacture of trinitrotoluol for use in Europe. When the war broke out in 1914 it shut off our supply of phenol (carbolic acid) for which we were dependent upon foreign sources. This threatened not only to afflict us with headaches by depriving us of aspirin but also to removed the consolation of music, for phenol is used in making phonographic records. Mr. Edison with his accustomed energy put up a factory within a few weeks for the manufacture of synthetic phenol. When we entered the war the need for phenol became yet more imperative, for it was needed to make picric acid for filling bombs. This demand was met, and in 1917 there were fifteen new plants turning out 64,146,499 pounds of phenol valued at $23,719,805. Some of the coal-tar products, as we see, serve many purposes. For instance, picric acid appears in three places in this book. It is a high explosive. It is a powerful and permanent yellow dye as any one who has touched it knows. Thirdly it is used as an antiseptic to cover burned skin. Other coal-tar dyes are used for the same purpose, "malachite green," "brilliant green," "crystal violet," "ethyl violet" and "Victoria blue," so a patient in a military hospital is decorated like an Easter egg. During the last five years surgeons have unfortunately had unprecedented opportunities for the study of wounds and fortunately they have been unprecedentedly successful in finding improved methods of treating them. In former wars a serious wound meant usually death or amputation. Now nearly ninety per cent. of the wounded are able to continue in the service. The reason for this improvement is that medicines are now being made to order instead of being gathered "from China to Peru." The old herb doctor picked up any strange plant that he could find and tried it on any sick man that would let him. This empirical method, though hard on the patients, resulted in the course of five thousand years in the discovery of a number of useful remedies. But the modern medicine man when he knows the cause of the disease is usually able to devise ways of counteracting it directly. For instance, he knows, thanks to Pasteur and Metchnikoff, that the cause of wound infection is the bacterial enemies of man which swarm by the million into any breach in his protective armor, the skin. Now when a breach is made in a line of intrenchments the defenders rush troops to the threatened spot for two purposes, constructive and destructive, engineers and warriors, the former to build up the rampart with sandbags, the latter to kill the enemy. So when the human body is invaded the blood brings to the breach two kinds of defenders. One is the serum which neutralizes the bacterial poison and by coagulating forms a new skin or scab over the exposed flesh. The other is the phagocytes or white corpuscles, the free lances of our corporeal militia, which attack and kill the invading bacteria. The aim of the physician then is to aid these defenders as much as possible without interfering with them. Therefore the antiseptic he is seeking is one that will assist the serum in protecting and repairing the broken tissues and will kill the hostile bacteria without killing the friendly phagocytes. Carbolic acid, the most familiar of the coal-tar antiseptics, will destroy the bacteria when it is diluted with 250 parts of water, but unfortunately it puts a stop to the fighting activities of the phagocytes when it is only half that strength, or one to 500, so it cannot destroy the infection without hindering the healing. In this search for substances that would attack a specific disease germ one of the leading investigators was Prof. Paul Ehrlich, a German physician of the Hebrew race. He found that the aniline dyes were useful for staining slides under the microscope, for they would pick out particular cells and leave others uncolored and from this starting point he worked out organic and metallic compounds which would destroy the bacteria and parasites that cause some of the most dreadful of diseases. A year after the war broke out Professor Ehrlich died while working in his laboratory on how to heal with coal-tar compounds the wounds inflicted by explosives from the same source. One of the most valuable of the aniline antiseptics employed by Ehrlich is flavine or, if the reader prefers to call it by its full name, diaminomethylacridinium chloride. Flavine, as its name implies, is a yellow dye and will kill the germs causing ordinary abscesses when in solution as dilute as one part of the dye to 200,000 parts of water, but it does not interfere with the bactericidal action of the white blood corpuscles unless the solution is 400 times as strong as this, that is one part in 500. Unlike carbolic acid and other antiseptics it is said to stimulate the serum instead of impairing its activity. Another antiseptic of the coal-tar family which has recently been brought into use by Dr. Dakin of the Rockefeller Institute is that called by European physicians chloramine-T and by American physicians chlorazene and by chemists para-toluene-sodium-sulfo-chloramide. This may serve to illustrate how a chemist is able to make such remedies as the doctor needs, instead of depending upon the accidental by-products of plants. On an earlier page I explained how by starting with the simplest of ring-compounds, the benzene of coal tar, we could get aniline. Suppose we go a step further and boil the aniline oil with acetic acid, which is the acid of vinegar minus its water. This easy process gives us acetanilid, which when introduced into the market some years ago under the name of "antifebrin" made a fortune for its makers. The making of medicines from coal tar began in 1874 when Kolbe made salicylic acid from carbolic acid. Salicylic acid is a rheumatism remedy and had previously been extracted from willow bark. If now we treat salicylic acid with concentrated acetic acid we get "aspirin." From aniline again are made "phenacetin," "antipyrin" and a lot of other drugs that have become altogether too popular as headache remedies--say rather "headache relievers." Another class of synthetics equally useful and likewise abused, are the soporifics, such as "sulphonal," "veronal" and "medinal." When it is not desired to put the patient to sleep but merely to render insensible a particular place, as when a tooth is to be pulled, cocain may be used. This, like alcohol and morphine, has proved a curse as well as a blessing and its sale has had to be restricted because of the many victims to the habit of using this drug. Cocain is obtained from the leaves of the South American coca tree, but can be made artificially from coal-tar products. The laboratory is superior to the forest because other forms of local anesthetics, such as eucain and novocain, can be made that are better than the natural alkaloid because more effective and less poisonous. I must not forget to mention another lot of coal-tar derivatives in which some of my readers will take a personal interest. That is the photographic developers. I am old enough to remember when we used to develop our plates in ferrous sulfate solution and you never saw nicer negatives than we got with it. But when pyrogallic acid came in we switched over to that even though it did stain our fingers and sometimes our plates. Later came a swarm of new organic reducing agents under various fancy names, such as metol, hydro (short for hydro-quinone) and eikongen ("the image-maker"). Every fellow fixed up his own formula and called his fellow-members of the camera club fools for not adopting it though he secretly hoped they would not. Under the double stimulus of patriotism and high prices the American drug and dyestuff industry developed rapidly. In 1917 about as many pounds of dyes were manufactured in America as were imported in 1913 and our _exports_ of American-made dyes exceeded in value our _imports_ before the war. In 1914 the output of American dyes was valued at $2,500,000. In 1917 it amounted to over $57,000,000. This does not mean that the problem was solved, for the home products were not equal in variety and sometimes not in quality to those made in Germany. Many valuable dyes were lacking and the cost was of course much higher. Whether the American industry can compete with the foreign in an open market and on equal terms is impossible to say because such conditions did not prevail before the war and they are not going to prevail in the future. Formerly the large German cartels through their agents and branches in this country kept the business in their own hands and now the American manufacturers are determined to maintain the independence they have acquired. They will not depend hereafter upon the tariff to cut off competition but have adopted more effective measures. The 4500 German chemical patents that had been seized by the Alien Property Custodian were sold by him for $250,000 to the Chemical Foundation, an association of American manufacturers organized "for the Americanization of such institutions as may be affected thereby, for the exclusion or elimination of alien interests hostile or detrimental to said industries and for the advancement of chemical and allied science and industry in the United States." The Foundation has a large fighting fund so that it "may be able to commence immediately and prosecute with the utmost vigor infringement proceedings whenever the first German attempt shall hereafter be made to import into this country." So much mystery has been made of the achievements of German chemists--as though the Teutonic brain had a special lobe for that faculty, lacking in other craniums--that I want to quote what Dr. Hesse says about his first impressions of a German laboratory of industrial research: Directly after graduating from the University of Chicago in 1896, I entered the employ of the largest coal-tar dye works in the world at its plant in Germany and indeed in one of its research laboratories. This was my first trip outside the United States and it was, of course, an event of the first magnitude for me to be in Europe, and, as a chemist, to be in Germany, in a German coal-tar dye plant, and to cap it all in its research laboratory--a real _sanctum sanctorum_ for chemists. In a short time the daily routine wore the novelty off my experience and I then settled down to calm analysis and dispassionate appraisal of my surroundings and to compare what was actually before and around me with my expectations. I found that the general laboratory equipment was no better than what I had been accustomed to; that my colleagues had no better fundamental training than I had enjoyed nor any better fact--or manipulative--equipment than I; that those in charge of the work had no better general intellectual equipment nor any more native ability than had my instructors; in short, there was nothing new about it all, nothing that we did not have back home, nothing--except the specific problems that were engaging their attention, and the special opportunities of attacking them. Those problems were of no higher order of complexity than those I had been accustomed to for years, in fact, most of them were not very complex from a purely intellectual viewpoint. There was nothing inherently uncanny, magical or wizardly about their occupation whatever. It was nothing but plain hard work and keeping everlastingly at it. Now, what was the actual thing behind that chemical laboratory that we did not have at home? It was money, willing to back such activity, convinced that in the final outcome, a profit would be made; money, willing to take university graduates expecting from them no special knowledge other than a good and thorough grounding in scientific research and provide them with opportunity to become specialists suited to the factory's needs. It is evidently not impossible to make the United States self-sufficient in the matter of coal-tar products. We've got the tar; we've got the men; we've got the money, too. Whether such a policy would pay us in the long run or whether it is necessary as a measure of military or commercial self-defense is another question that cannot here be decided. But whatever share we may have in it the coal-tar industry has increased the economy of civilization and added to the wealth of the world by showing how a waste by-product could be utilized for making new dyes and valuable medicines, a better use for tar than as fuel for political bonfires and as clothing for the nakedness of social outcasts. V SYNTHETIC PERFUMES AND FLAVORS The primitive man got his living out of such wild plants and animals as he could find. Next he, or more likely his wife, began to cultivate the plants and tame the animals so as to insure a constant supply. This was the first step toward civilization, for when men had to settle down in a community (_civitas_) they had to ameliorate their manners and make laws protecting land and property. In this settled and orderly life the plants and animals improved as well as man and returned a hundredfold for the pains that their master had taken in their training. But still man was dependent upon the chance bounties of nature. He could select, but he could not invent. He could cultivate, but he could not create. If he wanted sugar he had to send to the West Indies. If he wanted spices he had to send to the East Indies. If he wanted indigo he had to send to India. If he wanted a febrifuge he had to send to Peru. If he wanted a fertilizer he had to send to Chile. If he wanted rubber he had to send to the Congo. If he wanted rubies he had to send to Mandalay. If he wanted otto of roses he had to send to Turkey. Man was not yet master of his environment. This period of cultivation, the second stage of civilization, began before the dawn of history and lasted until recent times. We might almost say up to the twentieth century, for it was not until the fundamental laws of heredity were discovered that man could originate new species of plants and animals according to a predetermined plan by combining such characteristics as he desired to perpetuate. And it was not until the fundamental laws of chemistry were discovered that man could originate new compounds more suitable to his purpose than any to be found in nature. Since the progress of mankind is continuous it is impossible to draw a date line, unless a very jagged one, along the frontier of human culture, but it is evident that we are just entering upon the third era of evolution in which man will make what he needs instead of trying to find it somewhere. The new epoch has hardly dawned, yet already a man may stay at home in New York or London and make his own rubber and rubies, his own indigo and otto of roses. More than this, he can make gems and colors and perfumes that never existed since time began. The man of science has signed a declaration of independence of the lower world and we are now in the midst of the revolution. Our eyes are dazzled by the dawn of the new era. We know what the hunter and the horticulturist have already done for man, but we cannot imagine what the chemist can do. If we look ahead through the eyes of one of the greatest of French chemists, Berthelot, this is what we shall see: The problem of food is a chemical problem. Whenever energy can be obtained economically we can begin to make all kinds of aliment, with carbon borrowed from carbonic acid, hydrogen taken from the water and oxygen and nitrogen drawn from the air.... The day will come when each person will carry for his nourishment his little nitrogenous tablet, his pat of fatty matter, his package of starch or sugar, his vial of aromatic spices suited to his personal taste; all manufactured economically and in unlimited quantities; all independent of irregular seasons, drought and rain, of the heat that withers the plant and of the frost that blights the fruit; all free from pathogenic microbes, the origin of epidemics and the enemies of human life. On that day chemistry will have accomplished a world-wide revolution that cannot be estimated. There will no longer be hills covered with vineyards and fields filled with cattle. Man will gain in gentleness and morality because he will cease to live by the carnage and destruction of living creatures.... The earth will be covered with grass, flowers and woods and in it the human race will dwell in the abundance and joy of the legendary age of gold--provided that a spiritual chemistry has been discovered that changes the nature of man as profoundly as our chemistry transforms material nature. But this is looking so far into the future that we can trust no man's eyesight, not even Berthelot's. There is apparently no impossibility about the manufacture of synthetic food, but at present there is no apparent probability of it. There is no likelihood that the laboratory will ever rival the wheat field. The cornstalk will always be able to work cheaper than the chemist in the manufacture of starch. But in rarer and choicer products of nature the chemist has proved his ability to compete and even to excel. What have been from the dawn of history to the rise of synthetic chemistry the most costly products of nature? What could tempt a merchant to brave the perils of a caravan journey over the deserts of Asia beset with Arab robbers? What induced the Portuguese and Spanish mariners to risk their frail barks on perilous waters of the Cape of Good Hope or the Horn? The chief prizes were perfumes, spices, drugs and gems. And why these rather than what now constitutes the bulk of oversea and overland commerce? Because they were precious, portable and imperishable. If the merchant got back safe after a year or two with a little flask of otto of roses, a package of camphor and a few pearls concealed in his garments his fortune was made. If a single ship of the argosy sent out from Lisbon came back with a load of sandalwood, indigo or nutmeg it was regarded as a successful venture. You know from reading the Bible, or if not that, from your reading of Arabian Nights, that a few grains of frankincense or a few drops of perfumed oil were regarded as gifts worthy the acceptance of a king or a god. These products of the Orient were equally in demand by the toilet and the temple. The unctorium was an adjunct of the Roman bathroom. Kings had to be greased and fumigated before they were thought fit to sit upon a throne. There was a theory, not yet altogether extinct, that medicines brought from a distance were most efficacious, especially if, besides being expensive, they tasted bad like myrrh or smelled bad like asafetida. And if these failed to save the princely patient he was embalmed in aromatics or, as we now call them, antiseptics of the benzene series. Today, as always, men are willing to pay high for the titillation of the senses of smell and taste. The African savage will trade off an ivory tusk for a piece of soap reeking with synthetic musk. The clubman will pay $10 for a bottle of wine which consists mostly of water with about ten per cent. of alcohol, worth a cent or two, but contains an unweighable amount of the "bouquet" that can only be produced on the sunny slopes of Champagne or in the valley of the Rhine. But very likely the reader is quite as extravagant, for when one buys the natural violet perfumery he is paying at the rate of more than $10,000 a pound for the odoriferous oil it contains; the rest is mere water and alcohol. But you would not want the pure undiluted oil if you could get it, for it is unendurable. A single whiff of it paralyzes your sense of smell for a time just as a loud noise deafens you. Of the five senses, three are physical and two chemical. By touch we discern pressures and surface textures. By hearing we receive impressions of certain air waves and by sight of certain ether waves. But smell and taste lead us to the heart of the molecule and enable us to tell how the atoms are put together. These twin senses stand like sentries at the portals of the body, where they closely scrutinize everything that enters. Sounds and sights may be disagreeable, but they are never fatal. A man can live in a boiler factory or in a cubist art gallery, but he cannot live in a room containing hydrogen sulfide. Since it is more important to be warned of danger than guided to delights our senses are made more sensitive to pain than pleasure. We can detect by the smell one two-millionth of a milligram of oil of roses or musk, but we can detect one two-billionth of a milligram of mercaptan, which is the vilest smelling compound that man has so far invented. If you do not know how much a milligram is consider a drop picked up by the point of a needle and imagine that divided into two billion parts. Also try to estimate the weight of the odorous particles that guide a dog to the fox or warn a deer of the presence of man. The unaided nostril can rival the spectroscope in the detection and analysis of unweighable amounts of matter. What we call flavor or savor is a joint effect of taste and odor in which the latter predominates. There are only four tastes of importance, acid, alkaline, bitter and sweet. The acid, or sour taste, is the perception of hydrogen atoms charged with positive electricity. The alkaline, or soapy taste, is the perception of hydroxyl radicles charged with negative electricity. The bitter and sweet tastes and all the odors depend upon the chemical constitution of the compound, but the laws of the relation have not yet been worked out. Since these sense organs, the taste and smell buds, are sunk in the moist mucous membrane they can only be touched by substances soluble in water, and to reach the sense of smell they must also be volatile so as to be diffused in the air inhaled by the nose. The "taste" of food is mostly due to the volatile odors of it that creep up the back-stairs into the olfactory chamber. A chemist given an unknown substance would have to make an elementary analysis and some tedious tests to determine whether it contained methyl or ethyl groups, whether it was an aldehyde or an ester, whether the carbon atoms were singly or doubly linked and whether it was an open chain or closed. But let him get a whiff of it and he can give instantly a pretty shrewd guess as to these points. His nose knows. Although the chemist does not yet know enough to tell for certain from looking at the structural formula what sort of odor the compound would have or whether it would have any, yet we can divide odoriferous substances into classes according to their constitution. What are commonly known as "fruity" odors belong mostly to what the chemist calls the fatty or aliphatic series. For instance, we may have in a ripe fruit an alcohol (say ethyl or common alcohol) and an acid (say acetic or vinegar) and a combination of these, the ester or organic salt (in this case ethyl acetate), which is more odorous than either of its components. These esters of the fatty acids give the characteristic savor to many of our favorite fruits, candies and beverages. The pear flavor, amyl acetate, is made from acetic acid and amyl alcohol--though amyl alcohol (fusel oil) has a detestable smell. Pineapple is ethyl butyrate--but the acid part of it (butyric acid) is what gives Limburger cheese its aroma. These essential oils are easily made in the laboratory, but cannot be extracted from the fruit for separate use. If the carbon chain contains one or more double linkages we get the "flowery" perfumes. For instance, here is the symbol of geraniol, the chief ingredient of otto of roses: (CH_{3})_{2}C = CHCH_{2}CH_{2}C(CH_{3})_{2} = CHCH_{2}OH The rose would smell as sweet under another name, but it may be questioned whether it would stand being called by the name of dimethyl-2-6-octadiene-2-6-ol-8. Geraniol by oxidation goes into the aldehyde, citral, which occurs in lemons, oranges and verbena flowers. Another compound of this group, linalool, is found in lavender, bergamot and many flowers. Geraniol, as you would see if you drew up its structural formula in the way I described in the last chapter, contains a chain of six carbon atoms, that is, the same number as make a benzene ring. Now if we shake up geraniol and other compounds of this group (the diolefines) with diluted sulfuric acid the carbon chain hooks up to form a benzene ring, but with the other carbon atoms stretched across it; rather too complicated to depict here. These "bridged rings" of the formula C_{5}H_{8}, or some multiple of that, constitute the important group of the terpenes which occur in turpentine and such wild and woodsy things as sage, lavender, caraway, pine needles and eucalyptus. Going further in this direction we are led into the realm of the heavy oriental odors, patchouli, sandalwood, cedar, cubebs, ginger and camphor. Camphor can now be made directly from turpentine so we may be independent of Formosa and Borneo. When we have a six carbon ring without double linkings (cyclo-aliphatic) or with one or two such, we get soft and delicate perfumes like the violet (ionone and irone). But when these pass into the benzene ring with its three double linkages the odor becomes more powerful and so characteristic that the name "aromatic compound" has been extended to the entire class of benzene derivatives, although many of them are odorless. The essential oils of jasmine, orange blossoms, musk, heliotrope, tuberose, ylang ylang, etc., consist mostly of this class and can be made from the common source of aromatic compounds, coal tar. The synthetic flavors and perfumes are made in the same way as the dyes by starting with some coal-tar product or other crude material and building up the molecule to the desired complexity. For instance, let us start with phenol, the ill-smelling and poisonous carbolic acid of disagreeable associations and evil fame. Treat this to soda-water and it is transformed into salicylic acid, a white odorless powder, used as a preservative and as a rheumatism remedy. Add to this methyl alcohol which is obtained by the destructive distillation of wood and is much more poisonous than ordinary ethyl alcohol. The alcohol and the acid heated together will unite with the aid of a little sulfuric acid and we get what the chemist calls methyl salicylate and other people call oil of wintergreen, the same as is found in wintergreen berries and birch bark. We have inherited a taste for this from our pioneer ancestors and we use it extensively to flavor our soft drinks, gum, tooth paste and candy, but the Europeans have not yet found out how nice it is. But, starting with phenol again, let us heat it with caustic alkali and chloroform. This gives us two new compounds of the same composition, but differing a little in the order of the atoms. If you refer back to the diagram of the benzene ring which I gave in the last chapter, you will see that there are six hydrogen atoms attached to it. Now any or all these hydrogen atoms may be replaced by other elements or groups and what the product is depends not only on what the new elements are, but where they are put. It is like spelling words. The three letters _t_, _r_ and _a_ mean very different things according to whether they are put together as _art_, _tar_ or _rat_. Or, to take a more apposite illustration, every hostess knows that the success of her dinner depends upon how she seats her guests around the table. So in the case of aromatic compounds, a little difference in the seating arrangement around the benzene ring changes the character. The two derivatives of phenol, which we are now considering, have two substituting groups. One is--O-H (called the hydroxyl group). The other is--CHO (called the aldehyde group). If these are opposite (called the para position) we have an odorless white solid. If they are side by side (called the ortho position) we have an oil with the odor of meadowsweet. Treating the odorless solid with methyl alcohol we get audepine (or anisic aldehyde) which is the perfume of hawthorn blossoms. But treating the other of the twin products, the fragrant oil, with dry acetic acid ("Perkin's reaction") we get cumarin, which is the perfume part of the tonka or tonquin beans that our forefathers used to carry in their snuff boxes. One ounce of cumarin is equal to four pounds of tonka beans. It smells sufficiently like vanilla to be used as a substitute for it in cheap extracts. In perfumery it is known as "new mown hay." You may remember what I said on a former page about the career of William Henry Perkin, the boy who loved chemistry better than eating, and how he discovered the coal-tar dyes. Well, it is also to his ingenious mind that we owe the starting of the coal-tar perfume business which has had almost as important a development. Perkin made cumarin in 1868, but this, like the dye industry, escaped from English hands and flew over the North Sea. Before the war Germany was exporting $1,500,000 worth of synthetic perfumes a year. Part of these went to France, where they were mixed and put up in fancy bottles with French names and sold to Americans at fancy prices. The real vanilla flavor, vanillin, was made by Tiemann in 1874. At first it sold for nearly $800 a pound, but now it may be had for $10. How extensively it is now used in chocolate, ice cream, soda water, cakes and the like we all know. It should be noted that cumarin and vanillin, however they may be made, are not imitations, but identical with the chief constituent of the tonka and vanilla beans and, of course, are equally wholesome or harmless. But the nice palate can distinguish a richer flavor in the natural extracts, for they contain small quantities of other savory ingredients. A true perfume consists of a large number of odoriferous chemical compounds mixed in such proportions as to produce a single harmonious effect upon the sense of smell in a fine brand of perfume may be compounded a dozen or twenty different ingredients and these, if they are natural essences, are complex mixtures of a dozen or so distinct substances. Perfumery is one of the fine arts. The perfumer, like the orchestra leader, must know how to combine and coördinate his instruments to produce a desired sensation. A Wagnerian opera requires 103 musicians. A Strauss opera requires 112. Now if the concert manager wants to economize he will insist upon cutting down on the most expensive musicians and dropping out some of the others, say, the supernumerary violinists and the man who blows a single blast or tinkles a triangle once in the course of the evening. Only the trained ear will detect the difference and the manager can make more money. Suppose our mercenary impresario were unable to get into the concert hall of his famous rival. He would then listen outside the window and analyze the sound in this fashion: "Fifty per cent. of the sound is made by the tuba, 20 per cent. by the bass drum, 15 per cent. by the 'cello and 10 per cent. by the clarinet. There are some other instruments, but they are not loud and I guess if we can leave them out nobody will know the difference." So he makes up his orchestra out of these four alone and many people do not know the difference. The cheap perfumer goes about it in the same way. He analyzes, for instance, the otto or oil of roses which cost during the war $400 a pound--if you could get it at any price--and he finds that the chief ingredient is geraniol, costing only $5, and next is citronelol, costing $20; then comes nerol and others. So he makes up a cheap brand of perfumery out of three or four such compounds. But the genuine oil of roses, like other natural essences, contains a dozen or more constituents and to leave many of them out is like reducing an orchestra to a few loud-sounding instruments or a painting to a three-color print. A few years ago an attempt was made to make music electrically by producing separately each kind of sound vibration contained in the instruments imitated. Theoretically that seems easy, but practically the tone was not satisfactory because the tones and overtones of a full orchestra or even of a single violin are too numerous and complex to be reproduced individually. So the synthetic perfumes have not driven out the natural perfumes, but, on the contrary, have aided and stimulated the growth of flowers for essences. The otto or attar of roses, favorite of the Persian monarchs and romances, has in recent years come chiefly from Bulgaria. But wars are not made with rosewater and the Bulgars for the last five years have been engaged in other business than cultivating their own gardens. The alembic or still was invented by the Arabian alchemists for the purpose of obtaining the essential oil or attar of roses. But distillation, even with the aid of steam, is not altogether satisfactory. For instance, the distilled rose oil contains anywhere from 10 to 74 per cent. of a paraffin wax (stearopten) that is odorless and, on the other hand, phenyl-ethyl alcohol, which is an important constituent of the scent of roses, is broken up in the process of distillation. So the perfumer can improve on the natural or rather the distilled oil by leaving out part of the paraffin and adding the missing alcohol. Even the imported article taken direct from the still is not always genuine, for the wily Bulgar sometimes "increases the yield" by sprinkling his roses in the vat with synthetic geraniol just as the wily Italian pours a barrel of American cottonseed oil over his olives in the press. Another method of extracting the scent of flowers is by _enfleurage_, which takes advantage of the tendency of fats to absorb odors. You know how butter set beside fish in the ice box will get a fishy flavor. In _enfleurage_ moist air is carried up a tower passing alternately over trays of fresh flowers, say violets, and over glass plates covered with a thin layer of lard. The perfumed lard may then be used as a pomade or the perfume may be extracted by alcohol. But many sweet flowers do not readily yield an essential oil, so in such oases we have to rely altogether upon more or less successful substitutes. For instance, the perfumes sold under the names of "heliotrope," "lily of the valley," "lilac," "cyclamen," "honeysuckle," "sweet pea," "arbutus," "mayflower" and "magnolia" are not produced from these flowers but are simply imitations made from other essences, synthetic or natural. Among the "thousand flowers" that contribute to the "Eau de Mille Fleurs" are the civet cat, the musk deer and the sperm whale. Some of the published formulas for "Jockey Club" call for civet or ambergris and those of "Lavender Water" for musk and civet. The less said about the origin of these three animal perfumes the better. Fortunately they are becoming too expensive to use and are being displaced by synthetic products more agreeable to a refined imagination. The musk deer may now be saved from extinction since we can make tri-nitro-butyl-xylene from coal tar. This synthetic musk passes muster to human nostrils, but a cat will turn up her nose at it. The synthetic musk is not only much cheaper than the natural, but a dozen times as strong, or let us say, goes a dozen times as far, for nobody wants it any stronger. Such powerful scents as these are only pleasant when highly diluted, yet they are, as we have seen, essential ingredients of the finest perfumes. For instance, the natural oil of jasmine and other flowers contain traces of indols and skatols which have most disgusting odors. Though our olfactory organs cannot detect their presence yet we perceive their absence so they have to be put into the artificial perfume. Just so a brief but violent discord in a piece of music or a glaring color contrast in a painting may be necessary to the harmony of the whole. It is absurd to object to "artificial" perfumes, for practically all perfumes now sold are artificial in the sense of being compounded by the art of the perfumer and whether the materials he uses are derived from the flowers of yesteryear or of Carboniferous Era is nobody's business but his. And he does not tell. The materials can be purchased in the open market. Various recipes can be found in the books. But every famous perfumer guards well the secret of his formulas and hands it as a legacy to his posterity. The ancient Roman family of Frangipani has been made immortal by one such hereditary recipe. The Farina family still claims to have the exclusive knowledge of how to make Eau de Cologne. This famous perfume was first compounded by an Italian, Giovanni Maria Farina, who came to Cologne in 1709. It soon became fashionable and was for a time the only scent allowed at some of the German courts. The various published recipes contain from six to a dozen ingredients, chiefly the oils of neroli, rosemary, bergamot, lemon and lavender dissolved in very pure alcohol and allowed to age like wine. The invention, in 1895, of artificial neroli (orange flowers) has improved the product. French perfumery, like the German, had its origin in Italy, when Catherine de' Medici came to Paris as the bride of Henri II. She brought with her, among other artists, her perfumer, Sieur Toubarelli, who established himself in the flowery land of Grasse. Here for four hundred years the industry has remained rooted and the family formulas have been handed down from generation to generation. In the city of Grasse there were at the outbreak of the war fifty establishments making perfumes. The French perfumer does not confine himself to a single sense. He appeals as well to sight and sound and association. He adds to the attractiveness of his creation by a quaintly shaped bottle, an artistic box and an enticing name such as "Dans les Nues," "Le Coeur de Jeannette," "Nuit de Chine," "Un Air Embaumé," "Le Vertige," "Bon Vieux Temps," "L'Heure Bleue," "Nuit d'Amour," "Quelques Fleurs," "Djer-Kiss." The requirements of a successful scent are very strict. A perfume must be lasting, but not strong. All its ingredients must continue to evaporate in the same proportion, otherwise it will change odor and deteriorate. Scents kill one another as colors do. The minutest trace of some impurity or foreign odor may spoil the whole effect. To mix the ingredients in a vessel of any metal but aluminum or even to filter through a tin funnel is likely to impair the perfume. The odoriferous compounds are very sensitive and unstable bodies, otherwise they would have no effect upon the olfactory organ. The combination that would be suitable for a toilet water would not be good for a talcum powder and might spoil in a soap. Perfumery is used even in the "scentless" powders and soaps. In fact it is now used more extensively, if less intensively, than ever before in the history of the world. During the Unwashed Ages, commonly called the Dark Ages, between the destruction of the Roman baths and the construction of the modern bathroom, the art of the perfumer, like all the fine arts, suffered an eclipse. "The odor of sanctity" was in highest esteem and what that odor was may be imagined from reading the lives of the saints. But in the course of centuries the refinements of life began to seep back into Europe from the East by means of the Arabs and Crusaders, and chemistry, then chiefly the art of cosmetics, began to revive. When science, the greatest democratizing agent on earth, got into action it elevated the poor to the ranks of kings and priests in the delights of the palate and the nose. We should not despise these delights, for the pleasure they confer is greater, in amount at least, than that of the so-called higher senses. We eat three times a day; some of us drink oftener; few of us visit the concert hall or the art gallery as often as we do the dining room. Then, too, these primitive senses have a stronger influence upon our emotional nature than those acquired later in the course of evolution. As Kipling puts it: Smells are surer than sounds or sights To make your heart-strings crack. VI CELLULOSE Organic compounds, on which our life and living depend, consist chiefly of four elements: carbon, hydrogen, oxygen and nitrogen. These compounds are sometimes hard to analyze, but when once the chemist has ascertained their constitution he can usually make them out of their elements--if he wants to. He will not want to do it as a business unless it pays and it will not pay unless the manufacturing process is cheaper than the natural process. This depends primarily upon the cost of the crude materials. What, then, is the market price of these four elements? Oxygen and nitrogen are free as air, and as we have seen in the second chapter, their direct combination by the electric spark is possible. Hydrogen is free in the form of water but expensive to extricate by means of the electric current. But we need more carbon than anything else and where shall we get that? Bits of crystallized carbon can be picked up in South Africa and elsewhere, but those who can afford to buy them prefer to wear them rather than use them in making synthetic food. Graphite is rare and hard to melt. We must then have recourse to the compounds of carbon. The simplest of these, carbon dioxide, exists in the air but only four parts in ten thousand by volume. To extract the carbon and get it into combination with the other elements would be a difficult and expensive process. Here, then, we must call in cheap labor, the cheapest of all laborers, the plants. Pine trees on the highlands and cotton plants on the lowlands keep their green traps set all the day long and with the captured carbon dioxide build up cellulose. If, then, man wants free carbon he can best get it by charring wood in a kiln or digging up that which has been charred in nature's kiln during the Carboniferous Era. But there is no reason why he should want to go back to elemental carbon when he can have it already combined with hydrogen in the remains of modern or fossil vegetation. The synthetic products on which modern chemistry prides itself, such as vanillin, camphor and rubber, are not built up out of their elements, C, H and O, although they might be as a laboratory stunt. Instead of that the raw material of the organic chemist is chiefly cellulose, or the products of its recent or remote destructive distillation, tar and oil. It is unnecessary to tell the reader what cellulose is since he now holds a specimen of it in his hand, pretty pure cellulose except for the sizing and the specks of carbon that mar the whiteness of its surface. This utilization of cellulose is the chief cause of the difference between the modern world and the ancient, for what is called the invention of printing is essentially the inventing of paper. The Romans made type to stamp their coins and lead pipes with and if they had had paper to print upon the world might have escaped the Dark Ages. But the clay tablets of the Babylonians were cumbersome; the wax tablets of the Greeks were perishable; the papyrus of the Egyptians was fragile; parchment was expensive and penning was slow, so it was not until literature was put on a paper basis that democratic education became possible. At the present time sheepskin is only used for diplomas, treaties and other antiquated documents. And even if your diploma is written in Latin it is likely to be made of sulfated cellulose. The textile industry has followed the same law of development that I have indicated in the other industries. Here again we find the three stages of progress, (1) utilization of natural products, (2) cultivation of natural products, (3) manufacture of artificial products. The ancients were dependent upon plants, animals and insects for their fibers. China used silk, Greece and Rome used wool, Egypt used flax and India used cotton. In the course of cultivation for three thousand years the animal and vegetable fibers were lengthened and strengthened and cheapened. But at last man has risen to the level of the worm and can spin threads to suit himself. He can now rival the wasp in the making of paper. He is no longer dependent upon the flax and the cotton plant, but grinds up trees to get his cellulose. A New York newspaper uses up nearly 2000 acres of forest a year. The United States grinds up about five million cords of wood a year in the manufacture of pulp for paper and other purposes. In making "mechanical pulp" the blocks of wood, mostly spruce and hemlock, are simply pressed sidewise of the grain against wet grindstones. But in wood fiber the cellulose is in part combined with lignin, which is worse than useless. To break up the ligno-cellulose combine chemicals are used. The logs for this are not ground fine, but cut up by disk chippers. The chips are digested for several hours under heat and pressure with acid or alkali. There are three processes in vogue. In the most common process the reagent is calcium sulfite, made by passing sulfur fumes (SO_{2}) into lime water. In another process a solution of caustic of soda is used to disintegrate the wood. The third, known as the "sulfate" process, should rather be called the sulfide process since the active agent is an alkaline solution of sodium sulfide made by roasting sodium sulfate with the carbonaceous matter extracted from the wood. This sulfate process, though the most recent of the three, is being increasingly employed in this country, for by means of it the resinous pine wood of the South can be worked up and the final product, known as kraft paper because it is strong, is used for wrapping. But whatever the process we get nearly pure cellulose which, as you can see by examining this page under a microscope, consists of a tangled web of thin white fibers, the remains of the original cell walls. Owing to the severe treatment it has undergone wood pulp paper does not last so long as the linen rag paper used by our ancestors. The pages of the newspapers, magazines and books printed nowadays are likely to become brown and brittle in a few years, no great loss for the most part since they have served their purpose, though it is a pity that a few copies of the worst of them could not be printed on permanent paper for preservation in libraries so that future generations could congratulate themselves on their progress in civilization. But in our absorption in the printed page we must not forget the other uses of paper. The paper clothing, so often prophesied, has not yet arrived. Even paper collars have gone out of fashion--if they ever were in. In Germany during the war paper was used for socks, shirts and shoes as well as handkerchiefs and napkins but it could not stand wear and washing. Our sanitary engineers have set us to drinking out of sharp-edged paper cups and we blot our faces instead of wiping them. Twine is spun of paper and furniture made of the twine, a rival of rattan. Cloth and matting woven of paper yarn are being used for burlap and grass in the making of bags and suitcases. Here, however, we are not so much interested in manufactures of cellulose itself, that is, wood, paper and cotton, as we are in its chemical derivatives. Cellulose, as we can see from the symbol, C_{6}H_{10}O_{5}, is composed of the three elements of carbon, hydrogen and oxygen. These are present in the same proportion as in starch (C_{6}H_{10}O_{5}), while glucose or grape sugar (C_{6}H_{12}O_{6}) has one molecule of water more. But glucose is soluble in cold water and starch is soluble in hot, while cellulose is soluble in neither. Consequently cellulose cannot serve us for food, although some of the vegetarian animals, notably the goat, have a digestive apparatus that can handle it. In Finland and Germany birch wood pulp and straw were used not only as an ingredient of cattle food but also put into war bread. It is not likely, however, that the human stomach even under the pressure of famine is able to get much nutriment out of sawdust. But by digesting with dilute acid sawdust can be transformed into sugars and these by fermentation into alcohol, so it would be possible for a man after he has read his morning paper to get drunk on it. If the cellulose, instead of being digested a long time in dilute acid, is dipped into a solution of sulfuric acid (50 to 80 per cent.) and then washed and dried it acquires a hard, tough and translucent coating that makes it water-proof and grease-proof. This is the "parchment paper" that has largely replaced sheepskin. Strong alkali has a similar effect to strong acid. In 1844 John Mercer, a Lancashire calico printer, discovered that by passing cotton cloth or yarn through a cold 30 per cent. solution of caustic soda the fiber is shortened and strengthened. For over forty years little attention was paid to this discovery, but when it was found that if the material was stretched so that it could not shrink on drying the twisted ribbons of the cotton fiber were changed into smooth-walled cylinders like silk, the process came into general use and nowadays much that passes for silk is "mercerized" cotton. Another step was taken when Cross of London discovered that when the mercerized cotton was treated with carbon disulfide it was dissolved to a yellow liquid. This liquid contains the cellulose in solution as a cellulose xanthate and on acidifying or heating the cellulose is recovered in a hydrated form. If this yellow solution of cellulose is squirted out of tubes through extremely minute holes into acidulated water, each tiny stream becomes instantly solidified into a silky thread which may be spun and woven like that ejected from the spinneret of the silkworm. The origin of natural silk, if we think about it, rather detracts from the pleasure of wearing it, and if "he who needlessly sets foot upon a worm" is to be avoided as a friend we must hope that the advance of the artificial silk industry will be rapid enough to relieve us of the necessity of boiling thousands of baby worms in their cradles whenever we want silk stockings. On a plain rush hurdle a silkworm lay When a proud young princess came that way. The haughty daughter of a lordly king Threw a sidelong glance at the humble thing, Little thinking she walked in pride In the winding sheet where the silkworm died. But so far we have not reached a stage where we can altogether dispense with the services of the silkworm. The viscose threads made by the process look as well as silk, but they are not so strong, especially when wet. Besides the viscose method there are several other methods of getting cellulose into solution so that artificial fibers may be made from it. A strong solution of zinc chloride will serve and this process used to be employed for making the threads to be charred into carbon filaments for incandescent bulbs. Cellulose is also soluble in an ammoniacal solution of copper hydroxide. The liquid thus formed is squirted through a fine nozzle into a precipitating solution of caustic soda and glucose, which brings back the cellulose to its original form. In the chapter on explosives I explained how cellulose treated with nitric acid in the presence of sulfuric acid was nitrated. The cellulose molecule having three hydroxyl (--OH) groups, can take up one, two or three nitrate groups (--ONO_{2}). The higher nitrates are known as guncotton and form the basis of modern dynamite and smokeless powder. The lower nitrates, known as pyroxylin, are less explosive, although still very inflammable. All these nitrates are, like the original cellulose, insoluble in water, but unlike the original cellulose, soluble in a mixture of ether and alcohol. The solution is called collodion and is now in common use to spread a new skin over a wound. The great war might be traced back to Nobel's cut finger. Alfred Nobel was a Swedish chemist--and a pacifist. One day while working in the laboratory he cut his finger, as chemists are apt to do, and, again as chemists are apt to do, he dissolved some guncotton in ether-alcohol and swabbed it on the wound. At this point, however, his conduct diverges from the ordinary, for instead of standing idle, impatiently waving his hand in the air to dry the film as most people, including chemists, are apt to do, he put his mind on it and it occurred to him that this sticky stuff, slowly hardening to an elastic mass, might be just the thing he was hunting as an absorbent and solidifier of nitroglycerin. So instead of throwing away the extra collodion that he had made he mixed it with nitroglycerin and found that it set to a jelly. The "blasting gelatin" thus discovered proved to be so insensitive to shock that it could be safely transported or fired from a cannon. This was the first of the high explosives that have been the chief factor in modern warfare. But on the whole, collodion has healed more wounds than it has caused besides being of infinite service to mankind otherwise. It has made modern photography possible, for the film we use in the camera and moving picture projector consists of a gelatin coating on a pyroxylin backing. If collodion is forced through fine glass tubes instead of through a slit, it comes out a thread instead of a film. If the collodion jet is run into a vat of cold water the ether and alcohol dissolve; if it is run into a chamber of warm air they evaporate. The thread of nitrated cellulose may be rendered less inflammable by taking out the nitrate groups by treatment with ammonium or calcium sulfide. This restores the original cellulose, but now it is an endless thread of any desired thickness, whereas the native fiber was in size and length adapted to the needs of the cottonseed instead of the needs of man. The old motto, "If you want a thing done the way you want it you must do it yourself," explains why the chemist has been called in to supplement the work of nature in catering to human wants. Instead of nitric acid we may use strong acetic acid to dissolve the cotton. The resulting cellulose acetates are less inflammable than the nitrates, but they are more brittle and more expensive. Motion picture films made from them can be used in any hall without the necessity of imprisoning the operator in a fire-proof box where if anything happens he can burn up all by himself without disturbing the audience. The cellulose acetates are being used for auto goggles and gas masks as well as for windows in leather curtains and transparent coverings for index cards. A new use that has lately become important is the varnishing of aeroplane wings, as it does not readily absorb water or catch fire and makes the cloth taut and air-tight. Aeroplane wings can be made of cellulose acetate sheets as transparent as those of a dragon-fly and not easy to see against the sky. The nitrates, sulfates and acetates are the salts or esters of the respective acids, but recently true ethers or oxides of cellulose have been prepared that may prove still better since they contain no acid radicle and are neutral and stable. These are in brief the chief processes for making what is commonly but quite improperly called "artificial silk." They are not the same substance as silkworm silk and ought not to be--though they sometimes are--sold as such. They are none of them as strong as the silk fiber when wet, although if I should venture to say which of the various makes weakens the most on wetting I should get myself into trouble. I will only say that if you have a grudge against some fisherman give him a fly line of artificial silk, 'most any kind. The nitrate process was discovered by Count Hilaire de Chardonnet while he was at the Polytechnic School of Paris, and he devoted his life and his fortune trying to perfect it. Samples of the artificial silk were exhibited at the Paris Exposition in 1889 and two years later he started a factory at Basançon. In 1892, Cross and Bevan, English chemists, discovered the viscose or xanthate process, and later the acetate process. But although all four of these processes were invented in France and England, Germany reaped most benefit from the new industry, which was bringing into that country $6,000,000 a year before the war. The largest producer in the world was the Vereinigte Glanzstoff-Fabriken of Elberfeld, which was paying annual dividends of 34 per cent. in 1914. The raw materials, as may be seen, are cheap and abundant, merely cellulose, salt, sulfur, carbon, air and water. Any kind of cellulose can be used, cotton waste, rags, paper, or even wood pulp. The processes are various, the names of the products are numerous and the uses are innumerable. Even the most inattentive must have noticed the widespread employment of these new forms of cellulose. We can buy from a street barrow for fifteen cents near-silk neckties that look as well as those sold for seventy-five. As for wear--well, they all of them wear till after we get tired of wearing them. Paper "vulcanized" by being run through a 30 per cent. solution of zinc chloride and subjected to hydraulic pressure comes out hard and horny and may be used for trunks and suit cases. Viscose tubes for sausage containers are more sanitary and appetizing than the customary casings. Viscose replaces ramie or cotton in the Welsbach gas mantles. Viscose film, transparent and a thousandth of an inch thick (cellophane), serves for candy wrappers. Cellulose acetate cylinders spun out of larger orifices than silk are trying--not very successfully as yet--to compete with hog's bristles and horsehair. Stir powdered metals into the cellulose solution and you have the Bayko yarn. Bayko (from the manufacturers, Farbenfabriken vorm. Friedr. Bayer and Company) is one of those telescoped names like Socony, Nylic, Fominco, Alco, Ropeco, Ripans, Penn-Yan, Anzac, Dagor, Dora and Cadets, which will be the despair of future philologers. [Illustration: A PAPER MILL IN ACTION This photograph was taken in the barking room of the big pulp mill of the Great Northern Paper Company at Millinocket, Maine] [Illustration: CELLULOSE FROM WOOD PULP This is now made into a large variety of useful articles of which a few examples are here pictured] Soluble cellulose may enable us in time to dispense with the weaver as well as the silkworm. It may by one operation give us fabrics instead of threads. A machine has been invented for manufacturing net and lace, the liquid material being poured on one side of a roller and the fabric being reeled off on the other side. The process seems capable of indefinite extension and application to various sorts of woven, knit and reticulated goods. The raw material is cotton waste and the finished fabric is a good substitute for silk. As in the process of making artificial silk the cellulose is dissolved in a cupro-ammoniacal solution, but instead of being forced out through minute openings to form threads, as in that process, the paste is allowed to flow upon a revolving cylinder which is engraved with the pattern of the desired textile. A scraper removes the excess and the turning of the cylinder brings the paste in the engraved lines down into a bath which solidifies it. Tulle or net is now what is chiefly being turned out, but the engraved design may be as elaborate and artistic as desired, and various materials can be used. Since the threads wherever they cross are united, the fabric is naturally stronger than the ordinary. It is all of a piece and not composed of parts. In short, we seem to be on the eve of a revolution in textiles that is the same as that taking place in building materials. Our concrete structures, however great, are all one stone. They are not built up out of blocks, but cast as a whole. Lace has always been the aristocrat among textiles. It has maintained its exclusiveness hitherto by being based upon hand labor. In no other way could one get so much painful, patient toil put into such a light and portable form. A filmy thing twined about a neck or dropping from a wrist represented years of work by poor peasant girls or pallid, unpaid nuns. A visit to a lace factory, even to the public rooms where the wornout women were not to be seen, is enough to make one resolve never to purchase any such thing made by hand again. But our good resolutions do not last long and in time we forget the strained eyes and bowed backs, or, what is worse, value our bit of lace all the more because it means that some poor woman has put her life and health into it, netting and weaving, purling and knotting, twining and twisting, throwing and drawing, thread by thread, day after day, until her eyes can no longer see and her fingers have become stiffened. But man is not naturally cruel. He does not really enjoy being a slave driver, either of human or animal slaves, although he can be hardened to it with shocking ease if there seems no other way of getting what he wants. So he usually welcomes that Great Liberator, the Machine. He prefers to drive the tireless engine than to whip the straining horses. He had rather see the farmer riding at ease in a mowing machine than bending his back over a scythe. The Machine is not only the Great Liberator, it is the Great Leveler also. It is the most powerful of the forces for democracy. An aristocracy can hardly be maintained except by distinction in dress, and distinction in dress can only be maintained by sumptuary laws or costliness. Sumptuary laws are unconstitutional in this country, hence the stress laid upon costliness. But machinery tends to bring styles and fabrics within the reach of all. The shopgirl is almost as well dressed on the street as her rich customer. The man who buys ready-made clothing is only a few weeks behind the vanguard of the fashion. There is often no difference perceptible to the ordinary eye between cheap and high-priced clothing once the price tag is off. Jewels as a portable form of concentrated costliness have been in favor from the earliest ages, but now they are losing their factitious value through the advance of invention. Rubies of unprecedented size, not imitation, but genuine rubies, can now be manufactured at reasonable rates. And now we may hope that lace may soon be within the reach of all, not merely lace of the established forms, but new and more varied and intricate and beautiful designs, such as the imagination has been able to conceive, but the hand cannot execute. Dissolving nitrocellulose in ether and alcohol we get the collodion varnish that we are all familiar with since we have used it on our cut fingers. Spread it on cloth instead of your skin and it makes a very good leather substitute. As we all know to our cost the number of animals to be skinned has not increased so rapidly in recent years as the number of feet to be shod. After having gone barefoot for a million years or so the majority of mankind have decided to wear shoes and this change in fashion comes at a time, roughly speaking, when pasture land is getting scarce. Also there are books to be bound and other new things to be done for which leather is needed. The war has intensified the stringency; so has feminine fashion. The conventions require that the shoe-tops extend nearly to skirt-bottom and this means that an inch or so must be added to the shoe-top every year. Consequent to this rise in leather we have to pay as much for one shoe as we used to pay for a pair. Here, then, is a chance for Necessity to exercise her maternal function. And she has responded nobly. A progeny of new substances have been brought forth and, what is most encouraging to see, they are no longer trying to worm their way into favor as surreptitious surrogates under the names of "leatheret," "leatherine," "leatheroid" and "leather-this-or-that" but come out boldly under names of their own coinage and declare themselves not an imitation, not even a substitute, but "better than leather." This policy has had the curious result of compelling the cowhide men to take full pages in the magazines to call attention to the forgotten virtues of good old-fashioned sole-leather! There are now upon the market synthetic shoes that a vegetarian could wear with a clear conscience. The soles are made of some rubber composition; the uppers of cellulose fabric (canvas) coated with a cellulose solution such as I have described. Each firm keeps its own process for such substance a dead secret, but without prying into these we can learn enough to satisfy our legitimate curiosity. The first of the artificial fabrics was the old-fashioned and still indispensable oil-cloth, that is canvas painted or printed with linseed oil carrying the desired pigments. Linseed oil belongs to the class of compounds that the chemist calls "unsaturated" and the psychologist would call "unsatisfied." They take up oxygen from the air and become solid, hence are called the "drying oils," although this does not mean that they lose water, for they have not any to lose. Later, ground cork was mixed with the linseed oil and then it went by its Latin name, "linoleum." The next step was to cut loose altogether from the natural oils and use for the varnish a solution of some of the cellulose esters, usually the nitrate (pyroxylin or guncotton), more rarely the acetate. As a solvent the ether-alcohol mixture forming collodion was, as we have seen, the first to be employed, but now various other solvents are in use, among them castor oil, methyl alcohol, acetone, and the acetates of amyl or ethyl. Some of these will be recognized as belonging to the fruit essences that we considered in Chapter V, and doubtless most of us have perceived an odor as of over-ripe pears, bananas or apples mysteriously emanating from a newly lacquered radiator. With powdered bronze, imitation gold, aluminum or something of the kind a metallic finish can be put on any surface. Canvas coated or impregnated with such soluble cellulose gives us new flexible and durable fabrics that have other advantages over leather besides being cheaper and more abundant. Without such material for curtains and cushions the automobile business would have been sorely hampered. It promises to provide us with a book binding that will not crumble to powder in the course of twenty years. Linen collars may be water-proofed and possibly Dame Fashion--being a fickle lady--may some day relent and let us wear such sanitary and economical neckwear. For shoes, purses, belts and the like the cellulose varnish or veneer is usually colored and stamped to resemble the grain of any kind of leather desired, even snake or alligator. If instead of dissolving the cellulose nitrate and spreading it on fabric we combine it with camphor we get celluloid, a plastic solid capable of innumerable applications. But that is another story and must be reserved for the next chapter. But before leaving the subject of cellulose proper I must refer back again to its chief source, wood. We inherited from the Indians a well-wooded continent. But the pioneer carried an ax on his shoulder and began using it immediately. For three hundred years the trees have been cut down faster than they could grow, first to clear the land, next for fuel, then for lumber and lastly for paper. Consequently we are within sight of a shortage of wood as we are of coal and oil. But the coal and oil are irrecoverable while the wood may be regrown, though it would require another three hundred years and more to grow some of the trees we have cut down. For fuel a pound of coal is about equal to two pounds of wood, and a pound of gasoline to three pounds of wood in heating value, so there would be a great loss in efficiency and economy if the world had to go back to a wood basis. But when that time shall come, as, of course, it must come some time, the wood will doubtless not be burned in its natural state but will be converted into hydrogen and carbon monoxide in a gas producer or will be distilled in closed ovens giving charcoal and gas and saving the by-products, the tar and acid liquors. As it is now the lumberman wastes two-thirds of every tree he cuts down. The rest is left in the forest as stump and tops or thrown out at the mill as sawdust and slabs. The slabs and other scraps may be used as fuel or worked up into small wood articles like laths and clothes-pins. The sawdust is burned or left to rot. But it is possible, although it may not be profitable, to save all this waste. In a former chapter I showed the advantages of the introduction of by-product coke-ovens. The same principle applies to wood as to coal. If a cord of wood (128 cubic feet) is subjected to a process of destructive distillation it yields about 50 bushels of charcoal, 11,500 cubic feet of gas, 25 gallons of tar, 10 gallons of crude wood alcohol and 200 pounds of crude acetate of lime. Resinous woods such as pine and fir distilled with steam give turpentine and rosin. The acetate of lime gives acetic acid and acetone. The wood (methyl) alcohol is almost as useful as grain (ethyl) alcohol in arts and industry and has the advantage of killing off those who drink it promptly instead of slowly. The chemist is an economical soul. He is never content until he has converted every kind of waste product into some kind of profitable by-product. He now has his glittering eye fixed upon the mountains of sawdust that pile up about the lumber mills. He also has a notion that he can beat lumber for some purposes. VII SYNTHETIC PLASTICS In the last chapter I told how Alfred Nobel cut his finger and, daubing it over with collodion, was led to the discovery of high explosive, dynamite. I remarked that the first part of this process--the hurting and the healing of the finger--might happen to anybody but not everybody would be led to discovery thereby. That is true enough, but we must not think that the Swedish chemist was the only observant man in the world. About this same time a young man in Albany, named John Wesley Hyatt, got a sore finger and resorted to the same remedy and was led to as great a discovery. His father was a blacksmith and his education was confined to what he could get at the seminary of Eddytown, New York, before he was sixteen. At that age he set out for the West to make his fortune. He made it, but after a long, hard struggle. His trade of typesetter gave him a living in Illinois, New York or wherever he wanted to go, but he was not content with his wages or his hours. However, he did not strike to reduce his hours or increase his wages. On the contrary, he increased his working time and used it to increase his income. He spent his nights and Sundays in making billiard balls, not at all the sort of thing you would expect of a young man of his Christian name. But working with billiard balls is more profitable than playing with them--though that is not the sort of thing you would expect a man of my surname to say. Hyatt had seen in the papers an offer of a prize of $10,000 for the discovery of a satisfactory substitute for ivory in the making of billiard balls and he set out to get that prize. I don't know whether he ever got it or not, but I have in my hand a newly published circular announcing that Mr. Hyatt has now perfected a process for making billiard balls "better than ivory." Meantime he has turned out several hundred other inventions, many of them much more useful and profitable, but I imagine that he takes less satisfaction in any of them than he does in having solved the problem that he undertook fifty years ago. The reason for the prize was that the game on the billiard table was getting more popular and the game in the African jungle was getting scarcer, especially elephants having tusks more than 2-7/16 inches in diameter. The raising of elephants is not an industry that promises as quick returns as raising chickens or Belgian hares. To make a ball having exactly the weight, color and resiliency to which billiard players have become accustomed seemed an impossibility. Hyatt tried compressed wood, but while he did not succeed in making billiard balls he did build up a profitable business in stamped checkers and dominoes. Setting type in the way they did it in the sixties was hard on the hands. And if the skin got worn thin or broken the dirty lead type were liable to infect the fingers. One day in 1863 Hyatt, finding his fingers were getting raw, went to the cupboard where was kept the "liquid cuticle" used by the printers. But when he got there he found it was bare, for the vial had tipped over--you know how easily they tip over--and the collodion had run out and solidified on the shelf. Possibly Hyatt was annoyed, but if so he did not waste time raging around the office to find out who tipped over that bottle. Instead he pulled off from the wood a bit of the dried film as big as his thumb nail and examined it with that "'satiable curtiosity," as Kipling calls it, which is characteristic of the born inventor. He found it tough and elastic and it occurred to him that it might be worth $10,000. It turned out to be worth many times that. Collodion, as I have explained in previous chapters, is a solution in ether and alcohol of guncotton (otherwise known as pyroxylin or nitrocellulose), which is made by the action of nitric acid on cotton. Hyatt tried mixing the collodion with ivory powder, also using it to cover balls of the necessary weight and solidity, but they did not work very well and besides were explosive. A Colorado saloon keeper wrote in to complain that one of the billiard players had touched a ball with a lighted cigar, which set it off and every man in the room had drawn his gun. The trouble with the dissolved guncotton was that it could not be molded. It did not swell up and set; it merely dried up and shrunk. When the solvent evaporated it left a wrinkled, shriveled, horny film, satisfactory to the surgeon but not to the man who wanted to make balls and hairpins and knife handles out of it. In England Alexander Parkes began working on the problem in 1855 and stuck to it for ten years before he, or rather his backers, gave up. He tried mixing in various things to stiffen up the pyroxylin. Of these, camphor, which he tried in 1865, worked the best, but since he used castor oil to soften the mass articles made of "parkesine" did not hold up in all weathers. Another Englishman, Daniel Spill, an associate of Parkes, took up the problem where he had dropped it and turned out a better product, "xylonite," though still sticking to the idea that castor oil was necessary to get the two solids, the guncotton and the camphor, together. But Hyatt, hearing that camphor could be used and not knowing enough about what others had done to follow their false trails, simply mixed his camphor and guncotton together without any solvent and put the mixture in a hot press. The two solids dissolved one another and when the press was opened there was a clear, solid, homogeneous block of--what he named--"celluloid." The problem was solved and in the simplest imaginable way. Tissue paper, that is, cellulose, is treated with nitric acid in the presence of sulfuric acid. The nitration is not carried so far as to produce the guncotton used in explosives but only far enough to make a soluble nitrocellulose or pyroxylin. This is pulped and mixed with half the quantity of camphor, pressed into cakes and dried. If this mixture is put into steam-heated molds and subjected to hydraulic pressure it takes any desired form. The process remains essentially the same as was worked out by the Hyatt brothers in the factory they set up in Newark in 1872 and some of their original machines are still in use. But this protean plastic takes innumerable forms and almost as many names. Each factory has its own secrets and lays claim to peculiar merits. The fundamental product itself is not patented, so trade names are copyrighted to protect the product. I have already mentioned three, "parkesine," "xylonite" and "celluloid," and I may add, without exhausting the list of species belonging to this genus, "viscoloid," "lithoxyl," "fiberloid," "coraline," "eburite," "pulveroid," "ivorine," "pergamoid," "duroid," "ivortus," "crystalloid," "transparene," "litnoid," "petroid," "pasbosene," "cellonite" and "pyralin." Celluloid can be given any color or colors by mixing in aniline dyes or metallic pigments. The color may be confined to the surface or to the interior or pervade the whole. If the nitrated tissue paper is bleached the celluloid is transparent or colorless. In that case it is necessary to add an antacid such as urea to prevent its getting yellow or opaque. To make it opaque and less inflammable oxides or chlorides of zinc, aluminum, magnesium, etc., are mixed in. Without going into the question of their variations and relative merits we may consider the advantages of the pyroxylin plastics in general. Here we have a new substance, the product of the creative genius of man, and therefore adaptable to his needs. It is hard but light, tough but elastic, easily made and tolerably cheap. Heated to the boiling point of water it becomes soft and flexible. It can be turned, carved, ground, polished, bent, pressed, stamped, molded or blown. To make a block of any desired size simply pile up the sheets and put them in a hot press. To get sheets of any desired thickness, simply shave them off the block. To make a tube of any desired size, shape or thickness squirt out the mixture through a ring-shaped hole or roll the sheets around a hot bar. Cut the tube into sections and you have rings to be shaped and stamped into box bodies or napkin rings. Print words or pictures on a celluloid sheet, put a thin transparent sheet over it and weld them together, then you have something like the horn book of our ancestors, but better. Nowadays such things as celluloid and pyralin can be sold under their own name, but in the early days the artificial plastics, like every new thing, had to resort to _camouflage_, a very humiliating expedient since in some cases they were better than the material they were forced to imitate. Tortoise shell, for instance, cracks, splits and twists, but a "tortoise shell" comb of celluloid looks as well and lasts better. Horn articles are limited to size of the ceratinous appendages that can be borne on the animal's head, but an imitation of horn can be made of any thickness by wrapping celluloid sheets about a cone. Ivory, which also has a laminated structure, may be imitated by rolling together alternate white opaque and colorless translucent sheets. Some of the sheets are wrinkled in order to produce the knots and irregularities of the grain of natural ivory. Man's chief difficulty in all such work is to imitate the imperfections of nature. His whites are too white, his surfaces are too smooth, his shapes are too regular, his products are too pure. The precious red coral of the Mediterranean can be perfectly imitated by taking a cast of a coral branch and filling in the mold with celluloid of the same color and hardness. The clear luster of amber, the dead black of ebony, the cloudiness of onyx, the opalescence of alabaster, the glow of carnelian--once confined to the selfish enjoyment of the rich--are now within the reach of every one, thanks to this chameleon material. Mosaics may be multiplied indefinitely by laying together sheets and sticks of celluloid, suitably cut and colored to make up the picture, fusing the mass, and then shaving off thin layers from the end. That _chef d'oeuvre_ of the Venetian glass makers, the Battle of Isus, from the House of the Faun in Pompeii, can be reproduced as fast as the machine can shave them off the block. And the tesserae do not fall out like those you bought on the Rialto. The process thus does for mosaics, ivory and coral what printing does for pictures. It is a mechanical multiplier and only by such means can we ever attain to a state of democratic luxury. The product, in cases where the imitation is accurate, is equally valuable except to those who delight in thinking that coral insects, Italian craftsmen and elephants have been laboring for years to put a trinket into their hands. The Lord may be trusted to deal with such selfish souls according to their deserts. But it is very low praise for a synthetic product that it can pass itself off, more or less acceptably, as a natural product. If that is all we could do without it. It must be an improvement in some respects on anything to be found in nature or it does not represent a real advance. So celluloid and its congeners are not confined to the shapes of shell and coral and crystal, or to the grain of ivory and wood and horn, the colors of amber and amethyst and lapis lazuli, but can be given forms and textures and tints that were never known before 1869. Let me see now, have I mentioned all the uses of celluloid? Oh, no, there are handles for canes, umbrellas, mirrors and brushes, knives, whistles, toys, blown animals, card cases, chains, charms, brooches, badges, bracelets, rings, book bindings, hairpins, campaign buttons, cuff and collar buttons, cuffs, collars and dickies, tags, cups, knobs, paper cutters, picture frames, chessmen, pool balls, ping pong balls, piano keys, dental plates, masks for disfigured faces, penholders, eyeglass frames, goggles, playing cards--and you can carry on the list as far as you like. Celluloid has its disadvantages. You may mold, you may color the stuff as you will, the scent of the camphor will cling around it still. This is not usually objectionable except where the celluloid is trying to pass itself off for something else, in which case it deserves no sympathy. It is attacked and dissolved by hot acids and alkalies. It softens up when heated, which is handy in shaping it though not so desirable afterward. But the worst of its failings is its combustibility. It is not explosive, but it takes fire from a flame and burns furiously with clouds of black smoke. But celluloid is only one of many plastic substances that have been introduced to the present generation. A new and important group of them is now being opened up, the so-called "condensation products." If you will take down any old volume of chemical research you will find occasionally words to this effect: "The reaction resulted in nothing but an insoluble resin which was not further investigated." Such a passage would be marked with a tear if chemists were given to crying over their failures. For it is the epitaph of a buried hope. It likely meant the loss of months of labor. The reason the chemist did not do anything further with the gummy stuff that stuck up his test tube was because he did not know what to do with it. It could not be dissolved, it could not be crystallized, it could not be distilled, therefore it could not be purified, analyzed and identified. What had happened was in most cases this. The molecule of the compound that the chemist was trying to make had combined with others of its kind to form a molecule too big to be managed by such means. Financiers call the process a "merger." Chemists call it "polymerization." The resin was a molecular trust, indissoluble, uncontrollable and contaminating everything it touched. But chemists--like governments--have learned wisdom in recent years. They have not yet discovered in all cases how to undo the process of polymerization, or, if you prefer the financial phrase, how to unscramble the eggs. But they have found that these molecular mergers are very useful things in their way. For instance there is a liquid known as isoprene (C_{5}H_{8}). This on heating or standing turns into a gum, that is nothing less than rubber, which is some multiple of C_{5}H_{8}. For another instance there is formaldehyde, an acrid smelling gas, used as a disinfectant. This has the simplest possible formula for a carbohydrate, CH_{2}O. But in the leaf of a plant this molecule multiplies itself by six and turns into a sweet solid glucose (C_{6}H_{12}O_{6}), or with the loss of water into starch (C_{6}H_{10}O_{5}) or cellulose (C_{6}H_{10}O_{5}). But formaldehyde is so insatiate that it not only combines with itself but seizes upon other substances, particularly those having an acquisitive nature like its own. Such a substance is carbolic acid (phenol) which, as we all know, is used as a disinfectant like formaldehyde because it, too, has the power of attacking decomposable organic matter. Now Prof. Adolf von Baeyer discovered in 1872 that when phenol and formaldehyde were brought into contact they seized upon one another and formed a combine of unusual tenacity, that is, a resin. But as I have said, chemists in those days were shy of resins. Kleeberg in 1891 tried to make something out of it and W.H. Story in 1895 went so far as to name the product "resinite," but nothing came of it until 1909 when L.H. Baekeland undertook a serious and systematic study of this reaction in New York. Baekeland was a Belgian chemist, born at Ghent in 1863 and professor at Bruges. While a student at Ghent he took up photography as a hobby and began to work on the problem of doing away with the dark-room by producing a printing paper that could be developed under ordinary light. When he came over to America in 1889 he brought his idea with him and four years later turned out "Velox," with which doubtless the reader is familiar. Velox was never patented because, as Dr. Baekeland explained in his speech of acceptance of the Perkin medal from the chemists of America, lawsuits are too expensive. Manufacturers seem to be coming generally to the opinion that a synthetic name copyrighted as a trademark affords better protection than a patent. Later Dr. Baekeland turned his attention to the phenol condensation products, working gradually up from test tubes to ton vats according to his motto: "Make your mistakes on a small scale and your profits on a large scale." He found that when equal weights of phenol and formaldehyde were mixed and warmed in the presence of an alkaline catalytic agent the solution separated into two layers, the upper aqueous and the lower a resinous precipitate. This resin was soft, viscous and soluble in alcohol or acetone. But if it was heated under pressure it changed into another and a new kind of resin that was hard, inelastic, unplastic, infusible and insoluble. The chemical name of this product is "polymerized oxybenzyl methylene glycol anhydride," but nobody calls it that, not even chemists. It is called "Bakelite" after its inventor. The two stages in its preparation are convenient in many ways. For instance, porous wood may be soaked in the soft resin and then by heat and pressure it is changed to the bakelite form and the wood comes out with a hard finish that may be given the brilliant polish of Japanese lacquer. Paper, cardboard, cloth, wood pulp, sawdust, asbestos and the like may be impregnated with the resin, producing tough and hard material suitable for various purposes. Brass work painted with it and then baked at 300° F. acquires a lacquered surface that is unaffected by soap. Forced in powder or sheet form into molds under a pressure of 1200 to 2000 pounds to the square inch it takes the most delicate impressions. Billiard balls of bakelite are claimed to be better than ivory because, having no grain, they do not swell unequally with heat and humidity and so lose their sphericity. Pipestems and beads of bakelite have the clear brilliancy of amber and greater strength. Fountain pens made of it are transparent so you can see how much ink you have left. A new and enlarging field for bakelite and allied products is the making of noiseless gears for automobiles and other machinery, also of air-plane propellers. Celluloid is more plastic and elastic than bakelite. It is therefore more easily worked in sheets and small objects. Celluloid can be made perfectly transparent and colorless while bakelite is confined to the range between a clear amber and an opaque brown or black. On the other hand bakelite has the advantage in being tasteless, odorless, inert, insoluble and non-inflammable. This last quality and its high electrical resistance give bakelite its chief field of usefulness. Electricity was discovered by the Greeks, who found that amber (_electron_) when rubbed would pick up straws. This means simply that amber, like all such resinous substances, natural or artificial, is a non-conductor or di-electric and does not carry off and scatter the electricity collected on the surface by the friction. Bakelite is used in its liquid form for impregnating coils to keep the wires from shortcircuiting and in its solid form for commutators, magnetos, switch blocks, distributors, and all sorts of electrical apparatus for automobiles, telephones, wireless telegraphy, electric lighting, etc. Bakelite, however, is only one of an indefinite number of such condensation products. As Baeyer said long ago: "It seems that all the aldehydes will, under suitable circumstances, unite with the aromatic hydrocarbons to form resins." So instead of phenol, other coal tar products such as cresol, naphthol or benzene itself may be used. The carbon links (-CH_{2}-, methylene) necessary to hook these carbon rings together may be obtained from other substances than the aldehydes, for instance from the amines, or ammonia derivatives. Three chemists, L.V. Kedman, A.J. Weith and F.P. Broek, working in 1910 on the Industrial Fellowships of the late Robert Kennedy Duncan at the University of Kansas, developed a process using formin instead of formaldehyde. Formin--or, if you insist upon its full name, hexa-methylene-tetramine--is a sugar-like substance with a fish-like smell. This mixed with crystallized carbolic acid and slightly warmed melts to a golden liquid that sets on pouring into molds. It is still plastic and can be bent into any desired shape, but on further heating it becomes hard without the need of pressure. Ammonia is given off in this process instead of water which is the by-product in the case of formaldehyde. The product is similar to bakelite, exactly how similar is a question that the courts will have to decide. The inventors threatened to call it Phenyl-endeka-saligeno-saligenin, but, rightly fearing that this would interfere with its salability, they have named it "redmanol." A phenolic condensation product closely related to bakelite and redmanol is condensite, the invention of Jonas Walter Aylesworth. Aylesworth was trained in what he referred to as "the greatest university of the world, the Edison laboratory." He entered this university at the age of nineteen at a salary of $3 a week, but Edison soon found that he had in his new boy an assistant who could stand being shut up in the laboratory working day and night as long as he could. After nine years of close association with Edison he set up a little laboratory in his own back yard to work out new plastics. He found that by acting on naphthalene--the moth-ball stuff--with chlorine he got a series of useful products called "halowaxes." The lower chlorinated products are oils, which may be used for impregnating paper or soft wood, making it non-inflammable and impregnable to water. If four atoms of chlorine enter the naphthalene molecule the product is a hard wax that rings like a metal. Condensite is anhydrous and infusible, and like its rivals finds its chief employment in the insulation parts of electrical apparatus. The records of the Edison phonograph are made of it. So are the buttons of our blue-jackets. The Government at the outbreak of the war ordered 40,000 goggles in condensite frames to protect the eyes of our gunners from the glare and acid fumes. The various synthetics played an important part in the war. According to an ancient military pun the endurance of soldiers depends upon the strength of their soles. The new compound rubber soles were found useful in our army and the Germans attribute their success in making a little leather go a long way during the late war to the use of a new synthetic tanning material known as "neradol." There are various forms of this. Some are phenolic condensation products of formaldehyde like those we have been considering, but some use coal-tar compounds having no phenol groups, such as naphthalene sulfonic acid. These are now being made in England under such names as "paradol," "cresyntan" and "syntan." They have the advantage of the natural tannins such as bark in that they are of known strength and can be varied to suit. This very grasping compound, formaldehyde, will attack almost anything, even molecules many times its size. Gelatinous and albuminous substances of all sorts are solidified by it. Glue, skimmed milk, blood, eggs, yeast, brewer's slops, may by this magic agent be rescued from waste and reappear in our buttons, hairpins, roofing, phonographs, shoes or shoe-polish. The French have made great use of casein hardened by formaldehyde into what is known as "galalith" (i.e., milkstone). This is harder than celluloid and non-inflammable, but has the disadvantages of being more brittle and of absorbing moisture. A mixture of casein and celluloid has something of the merits of both. The Japanese, as we should expect, are using the juice of the soy bean, familiar as a condiment to all who patronize chop-sueys or use Worcestershire sauce. The soy glucine coagulated by formalin gives a plastic said to be better and cheaper than celluloid. Its inventor, S. Sato, of Sendai University, has named it, according to American precedent, "Satolite," and has organized a million-dollar Satolite Company at Mukojima. The algin extracted from the Pacific kelp can be used as a rubber surrogate for water-proofing cloth. When combined with heavier alkaline bases it forms a tough and elastic substance that can be rolled into transparent sheets like celluloid or turned into buttons and knife handles. In Australia when the war shut off the supply of tin the Government commission appointed to devise means of preserving fruits recommended the use of cardboard containers varnished with "magramite." This is a name the Australians coined for synthetic resin made from phenol and formaldehyde like bakelite. Magramite dissolved in alcohol is painted on the cardboard cans and when these are stoved the coating becomes insoluble. Tarasoff has made a series of condensation products from phenol and formaldehyde with the addition of sulfonated oils. These are formed by the action of sulfuric acid on coconut, castor, cottonseed or mineral oils. The products of this combination are white plastics, opaque, insoluble and infusible. Since I am here chiefly concerned with "Creative Chemistry," that is, with the art of making substances not found in nature, I have not spoken of shellac, asphaltum, rosin, ozocerite and the innumerable gums, resins and waxes, animal, mineral and vegetable, that are used either by themselves or in combination with the synthetics. What particular "dope" or "mud" is used to coat a canvas or form a telephone receiver is often hard to find out. The manufacturer finds secrecy safer than the patent office and the chemist of a rival establishment is apt to be baffled in his attempt to analyze and imitate. But we of the outside world are not concerned with this, though we are interested in the manifold applications of these new materials. There seems to be no limit to these compounds and every week the journals report new processes and patents. But we must not allow the new ones to crowd out the remembrance of the oldest and most famous of the synthetic plasters, hard rubber, to which a separate chapter must be devoted. VIII THE RACE FOR RUBBER There is one law that regulates all animate and inanimate things. It is formulated in various ways, for instance: Running down a hill is easy. In Latin it reads, _facilis descensus Averni._ Herbert Spencer calls it the dissolution of definite coherent heterogeneity into indefinite incoherent homogeneity. Mother Goose expresses it in the fable of Humpty Dumpty, and the business man extracts the moral as, "You can't unscramble an egg." The theologian calls it the dogma of natural depravity. The physicist calls it the second law of thermodynamics. Clausius formulates it as "The entropy of the world tends toward a maximum." It is easier to smash up than to build up. Children find that this is true of their toys; the Bolsheviki have found that it is true of a civilization. So, too, the chemist knows analysis is easier than synthesis and that creative chemistry is the highest branch of his art. This explains why chemists discovered how to take rubber apart over sixty years before they could find out how to put it together. The first is easy. Just put some raw rubber into a retort and heat it. If you can stand the odor you will observe the caoutchouc decomposing and a benzine-like liquid distilling over. This is called "isoprene." Any Freshman chemist could write the reaction for this operation. It is simply C_{10}H_{16} --> 2C_{5}H_{8} caoutchouc isoprene That is, one molecule of the gum splits up into two molecules of the liquid. It is just as easy to write the reaction in the reverse directions, as 2 isoprene--> 1 caoutchouc, but nobody could make it go in that direction. Yet it could be done. It had been done. But the man who did it did not know how he did it and could not do it again. Professor Tilden in May, 1892, read a paper before the Birmingham Philosophical Society in which he said: I was surprised a few weeks ago at finding the contents of the bottles containing isoprene from turpentine entirely changed in appearance. In place of a limpid, colorless liquid the bottles contained a dense syrup in which were floating several large masses of a yellowish color. Upon examination this turned out to be India rubber. But neither Professor Tilden nor any one else could repeat this accidental metamorphosis. It was tantalizing, for the world was willing to pay $2,000,000,000 a year for rubber and the forests of the Amazon and Congo were failing to meet the demand. A large share of these millions would have gone to any chemist who could find out how to make synthetic rubber and make it cheaply enough. With such a reward of fame and fortune the competition among chemists was intense. It took the form of an international contest in which England and Germany were neck and neck. [Illustration: Courtesy of the "India Rubber World." What goes into rubber and what is made out of it] The English, who had been beaten by the Germans in the dye business where they had the start, were determined not to lose in this. Prof. W.H. Perkin, of Manchester University, was one of the most eager, for he was inspired by a personal grudge against the Germans as well as by patriotism and scientific zeal. It was his father who had, fifty years before, discovered mauve, the first of the anilin dyes, but England could not hold the business and its rich rewards went over to Germany. So in 1909 a corps of chemists set to work under Professor Perkin in the Manchester laboratories to solve the problem of synthetic rubber. What reagent could be found that would reverse the reaction and convert the liquid isoprene into the solid rubber? It was discovered, by accident, we may say, but it should be understood that such advantageous accidents happen only to those who are working for them and know how to utilize them. In July, 1910, Dr. Matthews, who had charge of the research, set some isoprene to drying over metallic sodium, a common laboratory method of freeing a liquid from the last traces of water. In September he found that the flask was filled with a solid mass of real rubber instead of the volatile colorless liquid he had put into it. Twenty years before the discovery would have been useless, for sodium was then a rare and costly metal, a little of it in a sealed glass tube being passed around the chemistry class once a year as a curiosity, or a tiny bit cut off and dropped in water to see what a fuss it made. But nowadays metallic sodium is cheaply produced by the aid of electricity. The difficulty lay rather in the cost of the raw material, isoprene. In industrial chemistry it is not sufficient that a thing can be made; it must be made to pay. Isoprene could be obtained from turpentine, but this was too expensive and limited in supply. It would merely mean the destruction of pine forests instead of rubber forests. Starch was finally decided upon as the best material, since this can be obtained for about a cent a pound from potatoes, corn and many other sources. Here, however, the chemist came to the end of his rope and had to call the bacteriologist to his aid. The splitting of the starch molecule is too big a job for man; only the lower organisms, the yeast plant, for example, know enough to do that. Owing perhaps to the _entente cordiale_ a French biologist was called into the combination, Professor Fernbach, of the Pasteur Institute, and after eighteen months' hard work he discovered a process of fermentation by which a large amount of fusel oil can be obtained from any starchy stuff. Hitherto the aim in fermentation and distillation had been to obtain as small a proportion of fusel as possible, for fusel oil is a mixture of the heavier alcohols, all of them more poisonous and malodorous than common alcohol. But here, as has often happened in the history of industrial chemistry, the by-product turned out to be more valuable than the product. From fusel oil by the use of chlorine isoprene can be prepared, so the chain was complete. But meanwhile the Germans had been making equal progress. In 1905 Prof. Karl Harries, of Berlin, found out the name of the caoutchouc molecule. This discovery was to the chemists what the architect's plan of a house is to the builder. They knew then what they were trying to construct and could go about their task intelligently. Mark Twain said that he could understand something about how astronomers could measure the distance of the planets, calculate their weights and so forth, but he never could see how they could find out their names even with the largest telescopes. This is a joke in astronomy but it is not in chemistry. For when the chemist finds out the structure of a compound he gives it a name which means that. The stuff came to be called "caoutchouc," because that was the way the Spaniards of Columbus's time caught the Indian word "cahuchu." When Dr. Priestley called it "India rubber" he told merely where it came from and what it was good for. But when Harries named it "1-5-dimethyl-cyclo-octadien-1-5" any chemist could draw a picture of it and give a guess as to how it could be made. Even a person without any knowledge of chemistry can get the main point of it by merely looking at this diagram: C C C---C || || || | C--C C C--C C | | --> | | C C--C C C--C || || | || C C C---C [Illustration: isoprene _turns into_ caoutchouc] I have dropped the 16 H's or hydrogen atoms of the formula for simplicity's sake. They simply hook on wherever they can. You will see that the isoprene consists of a chain of four carbon atoms (represented by the C's) with an extra carbon on the side. In the transformation of this colorless liquid into soft rubber two of the double linkages break and so permit the two chains of 4 C's to unite to form one ring of eight. If you have ever played ring-around-a-rosy you will get the idea. In Chapter IV I explained that the anilin dyes are built up upon the benzene ring of six carbon atoms. The rubber ring consists of eight at least and probably more. Any substance containing that peculiar carbon chain with two double links C=C-C=C can double up--polymerize, the chemist calls it--into a rubber-like substance. So we may have many kinds of rubber, some of which may prove to be more useful than that which happens to be found in nature. With the structural formula of Harries as a clue chemists all over the world plunged into the problem with renewed hope. The famous Bayer dye works at Elberfeld took it up and there in August, 1909, Dr. Fritz Hofmann worked out a process for the converting of pure isoprene into rubber by heat. Then in 1910 Harries happened upon the same sodium reaction as Matthews, but when he came to get it patented he found that the Englishman had beaten him to the patent office by a few weeks. This Anglo-German rivalry came to a dramatic climax in 1912 at the great hall of the College of the City of New York when Dr. Carl Duisberg, of the Elberfeld factory, delivered an address on the latest achievements of the chemical industry before the Eighth--and the last for a long time--International Congress of Applied Chemistry. Duisberg insisted upon talking in German, although more of his auditors would have understood him in English. He laid full emphasis upon German achievements and cast doubt upon the claim of "the Englishman Tilden" to have prepared artificial rubber in the eighties. Perkin, of Manchester, confronted him with his new process for making rubber from potatoes, but Duisberg countered by proudly displaying two automobile tires made of synthetic rubber with which he had made a thousand-mile run. The intense antagonism between the British and German chemists at this congress was felt by all present, but we did not foresee that in two years from that date they would be engaged in manufacturing poison gas to fire at one another. It was, however, realized that more was at stake than personal reputation and national prestige. Under pressure of the new demand for automobiles the price of rubber jumped from $1.25 to $3 a pound in 1910, and millions had been invested in plantations. If Professor Perkin was right when he told the congress that by his process rubber could be made for less than 25 cents a pound it meant that these plantations would go the way of the indigo plantations when the Germans succeeded in making artificial indigo. If Dr. Duisberg was right when he told the congress that synthetic rubber would "certainly appear on the market in a very short time," it meant that Germany in war or peace would become independent of Brazil in the matter of rubber as she had become independent of Chile in the matter of nitrates. As it turned out both scientists were too sanguine. Synthetic rubber has not proved capable of displacing natural rubber by underbidding it nor even of replacing natural rubber when this is shut out. When Germany was blockaded and the success of her armies depended on rubber, price was no object. Three Danish sailors who were caught by United States officials trying to smuggle dental rubber into Germany confessed that they had been selling it there for gas masks at $73 a pound. The German gas masks in the latter part of the war were made without rubber and were frail and leaky. They could not have withstood the new gases which American chemists were preparing on an unprecedented scale. Every scrap of old rubber in Germany was saved and worked over and over and diluted with fillers and surrogates to the limit of elasticity. Spring tires were substituted for pneumatics. So it is evident that the supply of synthetic rubber could not have been adequate or satisfactory. Neither, on the other hand, have the British made a success of the Perkin process, although they spent $200,000 on it in the first two years. But, of course, there was not the same necessity for it as in the case of Germany, for England had practically a monopoly of the world's supply of natural rubber either through owning plantations or controlling shipping. If rubber could not be manufactured profitably in Germany when the demand was imperative and price no consideration it can hardly be expected to compete with the natural under peace conditions. The problem of synthetic rubber has then been solved scientifically but not industrially. It can be made but cannot be made to pay. The difficulty is to find a cheap enough material to start with. We can make rubber out of potatoes--but potatoes have other uses. It would require more land and more valuable land to raise the potatoes than to raise the rubber. We can get isoprene by the distillation of turpentine--but why not bleed a rubber tree as well as a pine tree? Turpentine is neither cheap nor abundant enough. Any kind of wood, sawdust for instance, can be utilized by converting the cellulose over into sugar and fermenting this to alcohol, but the process is not likely to prove profitable. Petroleum when cracked up to make gasoline gives isoprene or other double-bond compounds that go over into some form of rubber. But the most interesting and most promising of all is the complete inorganic synthesis that dispenses with the aid of vegetation and starts with coal and lime. These heated together in the electric furnace form calcium carbide and this, as every automobilist knows, gives acetylene by contact with water. From this gas isoprene can be made and the isoprene converted into rubber by sodium, or acid or alkali or simple heating. Acetone, which is also made from acetylene, can be converted directly into rubber by fuming sulfuric acid. This seems to have been the process chiefly used by the Germans during the war. Several carbide factories were devoted to it. But the intermediate and by-products of the process, such as alcohol, acetic acid and acetone, were in as much demand for war purposes as rubber. The Germans made some rubber from pitch imported from Sweden. They also found a useful substitute in aluminum naphthenate made from Baku petroleum, for it is elastic and plastic and can be vulcanized. So although rubber can be made in many different ways it is not profitable to make it in any of them. We have to rely still upon the natural product, but we can greatly improve upon the way nature produces it. When the call came for more rubber for the electrical and automobile industries the first attempt to increase the supply was to put pressure upon the natives to bring in more of the latex. As a consequence the trees were bled to death and sometimes also the natives. The Belgian atrocities in the Congo shocked the civilized world and at Putumayo on the upper Amazon the same cause produced the same horrible effects. But no matter what cruelty was practiced the tropical forests could not be made to yield a sufficient increase, so the cultivation of the rubber was begun by far-sighted men in Dutch Java, Sumatra and Borneo and in British Malaya and Ceylon. Brazil, feeling secure in the possession of a natural monopoly, made no effort to compete with these parvenus. It cost about as much to gather rubber from the Amazon forests as it did to raise it on a Malay plantation, that is, 25 cents a pound. The Brazilian Government clapped on another 25 cents export duty and spent the money lavishly. In 1911 the treasury of Para took in $2,000,000 from the rubber tax and a good share of the money was spent on a magnificent new theater at Manaos--not on setting out rubber trees. The result of this rivalry between the collector and the cultivator is shown by the fact that in the decade 1907-1917 the world's output of plantation rubber increased from 1000 to 204,000 tons, while the output of wild rubber decreased from 68,000 to 53,000. Besides this the plantation rubber is a cleaner and more even product, carefully coagulated by acetic acid instead of being smoked over a forest fire. It comes in pale yellow sheets instead of big black balls loaded with the dirt or sticks and stones that the honest Indian sometimes adds to make a bigger lump. What's better, the man who milks the rubber trees on a plantation may live at home where he can be decently looked after. The agriculturist and the chemist may do what the philanthropist and statesman could not accomplish: put an end to the cruelties involved in the international struggle for "black gold." The United States uses three-fourths of the world's rubber output and grows none of it. What is the use of tropical possessions if we do not make use of them? The Philippines could grow all our rubber and keep a $300,000,000 business under our flag. Santo Domingo, where rubber was first discovered, is now under our supervision and could be enriched by the industry. The Guianas, where the rubber tree was first studied, might be purchased. It is chiefly for lack of a definite colonial policy that our rubber industry, by far the largest in the world, has to be dependent upon foreign sources for all its raw materials. Because the Philippines are likely to be cast off at any moment, American manufacturers are placing their plantations in the Dutch or British possessions. The Goodyear Company has secured a concession of 20,000 acres near Medan in Dutch Sumatra. While the United States is planning to relinquish its Pacific possessions the British have more than doubled their holdings in New Guinea by the acquisition of Kaiser Wilhelm's Land, good rubber country. The British Malay States in 1917 exported over $118,000,000 worth of plantation-grown rubber and could have sold more if shipping had not been short and production restricted. Fully 90 per cent. of the cultivated rubber is now grown in British colonies or on British plantations in the Dutch East Indies. To protect this monopoly an act has been passed preventing foreigners from buying more land in the Malay Peninsula. The Japanese have acquired there 50,000 acres, on which they are growing more than a million dollars' worth of rubber a year. The British _Tropical Life_ says of the American invasion: "As America is so extremely wealthy Uncle Sam can well afford to continue to buy our rubber as he has been doing instead of coming in to produce rubber to reduce his competition as a buyer in the world's market." The Malaya estates calculate to pay a dividend of 20 per cent. on the investment with rubber selling at 30 cents a pound and every two cents additional on the price brings a further 3-1/2 per cent. dividend. The output is restricted by the Rubber Growers' Association so as to keep the price up to 50-70 cents. When the plantations first came into bearing in 1910 rubber was bringing nearly $3 a pound, and since it can be produced at less than 30 cents a pound we can imagine the profits of the early birds. The fact that the world's rubber trade was in the control of Great Britain caused America great anxiety and financial loss in the early part of the war when the British Government, suspecting--not without reason--that some American rubber goods were getting into Germany through neutral nations, suddenly shut off our supply. This threatened to kill the fourth largest of our industries and it was only by the submission of American rubber dealers to the closest supervision and restriction by the British authorities that they were allowed to continue their business. Sir Francis Hopwood, in laying down these regulations, gave emphatic warning "that in case any manufacturer, importer or dealer came under suspicion his permits should be immediately revoked. Reinstatement will be slow and difficult. The British Government will cancel first and investigate afterward." Of course the British had a right to say under what conditions they should sell their rubber and we cannot blame them for taking such precautions to prevent its getting to their enemies, but it placed the United States in a humiliating position and if we had not been in sympathy with their side it would have aroused more resentment than it did. But it made evident the desirability of having at least part of our supply under our own control and, if possible, within our own country. Rubber is not rare in nature, for it is contained in almost every milky juice. Every country boy knows that he can get a self-feeding mucilage brush by cutting off a milkweed stalk. The only native source so far utilized is the guayule, which grows wild on the deserts of the Mexican and the American border. The plant was discovered in 1852 by Dr. J.M. Bigelow near Escondido Creek, Texas. Professor Asa Gray described it and named it Parthenium argentatum, or the silver Pallas. When chopped up and macerated guayule gives a satisfactory quality of caoutchouc in profitable amounts. In 1911 seven thousand tons of guayule were imported from Mexico; in 1917 only seventeen hundred tons. Why this falling off? Because the eager exploiters had killed the goose that laid the golden egg, or in plain language, pulled up the plant by the roots. Now guayule is being cultivated and is reaped instead of being uprooted. Experiments at the Tucson laboratory have recently removed the difficulty of getting the seed to germinate under cultivation. This seems the most promising of the home-grown plants and, until artificial rubber can be made profitable, gives us the only chance of being in part independent of oversea supply. There are various other gums found in nature that can for some purposes be substituted for caoutchouc. Gutta percha, for instance, is pliable and tough though not very elastic. It becomes plastic by heat so it can be molded, but unlike rubber it cannot be hardened by heating with sulfur. A lump of gutta percha was brought from Java in 1766 and placed in a British museum, where it lay for nearly a hundred years before it occurred to anybody to do anything with it except to look at it. But a German electrician, Siemens, discovered in 1847 that gutta percha was valuable for insulating telegraph lines and it found extensive employment in submarine cables as well as for golf balls, and the like. Balata, which is found in the forests of the Guianas, is between gutta percha and rubber, not so good for insulation but useful for shoe soles and machine belts. The bark of the tree is so thick that the latex does not run off like caoutchouc when the bark is cut. So the bark has to be cut off and squeezed in hand presses. Formerly this meant cutting down the tree, but now alternate strips of the bark are cut off and squeezed so the tree continues to live. When Columbus discovered Santo Domingo he found the natives playing with balls made from the gum of the caoutchouc tree. The soldiers of Pizarro, when they conquered Inca-Land, adopted the Peruvian custom of smearing caoutchouc over their coats to keep out the rain. A French scientist, M. de la Condamine, who went to South America to measure the earth, came back in 1745 with some specimens of caoutchouc from Para as well as quinine from Peru. The vessel on which he returned, the brig _Minerva_, had a narrow escape from capture by an English cruiser, for Great Britain was jealous of any trespassing on her American sphere of influence. The Old World need not have waited for the discovery of the New, for the rubber tree grows wild in Annam as well as Brazil, but none of the Asiatics seems to have discovered any of the many uses of the juice that exudes from breaks in the bark. The first practical use that was made of it gave it the name that has stuck to it in English ever since. Magellan announced in 1772 that it was good to remove pencil marks. A lump of it was sent over from France to Priestley, the clergyman chemist who discovered oxygen and was mobbed out of Manchester for being a republican and took refuge in Pennsylvania. He cut the lump into little cubes and gave them to his friends to eradicate their mistakes in writing or figuring. Then they asked him what the queer things were and he said that they were "India rubbers." [Illustration: FOREST RUBBER Compare this tropical tangle and gnarled trunk with the straight tree and cleared ground of the plantation. At the foot of the trunk are cups collecting rubber juice.] [Illustration: PLANTATION RUBBER This spiral cut draws off the milk as completely and quickly as possible without harming the tree. The man is pulling off a strip of coagulated rubber that clogs it.] [Illustration: IN MAKING GARDEN HOSE THE RUBBER IS FORMED INTO A TUBE BY THE MACHINE ON THE RIGHT AND COILED ON THE TABLE TO THE LEFT] The Peruvian natives had used caoutchouc for water-proof clothing, shoes, bottles and syringes, but Europe was slow to take it up, for the stuff was too sticky and smelled too bad in hot weather to become fashionable in fastidious circles. In 1825 Mackintosh made his name immortal by putting a layer of rubber between two cloths. A German chemist, Ludersdorf, discovered in 1832 that the gum could be hardened by treating it with sulfur dissolved in turpentine. But it was left to a Yankee inventor, Charles Goodyear, of Connecticut, to work out a practical solution of the problem. A friend of his, Hayward, told him that it had been revealed to him in a dream that sulfur would harden rubber, but unfortunately the angel or defunct chemist who inspired the vision failed to reveal the details of the process. So Hayward sold out his dream to Goodyear, who spent all his own money and all he could borrow from his friends trying to convert it into a reality. He worked for ten years on the problem before the "lucky accident" came to him. One day in 1839 he happened to drop on the hot stove of the kitchen that he used as a laboratory a mixture of caoutchouc and sulfur. To his surprise he saw the two substances fuse together into something new. Instead of the soft, tacky gum and the yellow, brittle brimstone he had the tough, stable, elastic solid that has done so much since to make our footing and wheeling safe, swift and noiseless. The gumshoes or galoshes that he was then enabled to make still go by the name of "rubbers" in this country, although we do not use them for pencil erasers. Goodyear found that he could vary this "vulcanized rubber" at will. By adding a little more sulfur he got a hard substance which, however, could be softened by heat so as to be molded into any form wanted. Out of this "hard rubber" "vulcanite" or "ebonite" were made combs, hairpins, penholders and the like, and it has not yet been superseded for some purposes by any of its recent rivals, the synthetic resins. The new form of rubber made by the Germans, methyl rubber, is said to be a superior substitute for the hard variety but not satisfactory for the soft. The electrical resistance of the synthetic product is 20 per cent, higher than the natural, so it is excellent for insulation, but it is inferior in elasticity. In the latter part of the war the methyl rubber was manufactured at the rate of 165 tons a month. The first pneumatic tires, known then as "patent aerial wheels," were invented by Robert William Thomson of London in 1846. On the following year a carriage equipped with them was seen in the streets of New York City. But the pneumatic tire did not come into use until after 1888, when an Irish horse-doctor, John Boyd Dunlop, of Belfast, tied a rubber tube around the wheels of his little son's velocipede. Within seven years after that a $25,000,000 corporation was manufacturing Dunlop tires. Later America took the lead in this business. In 1913 the United States exported $3,000,000 worth of tires and tubes. In 1917 the American exports rose to $13,000,000, not counting what went to the Allies. The number of pneumatic tires sold in 1917 is estimated at 18,000,000, which at an average cost of $25 would amount to $450,000,000. No matter how much synthetic rubber may be manufactured or how many rubber trees are set out there is no danger of glutting the market, for as the price falls the uses of rubber become more numerous. One can think of a thousand ways in which rubber could be used if it were only cheap enough. In the form of pads and springs and tires it would do much to render traffic noiseless. Even the elevated railroad and the subway might be opened to conversation, and the city made habitable for mild voiced and gentle folk. It would make one's step sure, noiseless and springy, whether it was used individualistically as rubber heels or collectivistically as carpeting and paving. In roofing and siding and paint it would make our buildings warmer and more durable. It would reduce the cost and permit the extension of electrical appliances of almost all kinds. In short, there is hardly any other material whose abundance would contribute more to our comfort and convenience. Noise is an automatic alarm indicating lost motion and wasted energy. Silence is economy and resiliency is superior to resistance. A gumshoe outlasts a hobnailed sole and a rubber tube full of air is better than a steel tire. IX THE RIVAL SUGARS The ancient Greeks, being an inquisitive and acquisitive people, were fond of collecting tales of strange lands. They did not care much whether the stories were true or not so long as they were interesting. Among the marvels that the Greeks heard from the Far East two of the strangest were that in India there were plants that bore wool without sheep and reeds that bore honey without bees. These incredible tales turned out to be true and in the course of time Europe began to get a little calico from Calicut and a kind of edible gravel that the Arabs who brought it called "sukkar." But of course only kings and queens could afford to dress in calico and have sugar prescribed for them when they were sick. Fortunately, however, in the course of time the Arabs invaded Spain and forced upon the unwilling inhabitants of Europe such instrumentalities of higher civilization as arithmetic and algebra, soap and sugar. Later the Spaniards by an act of equally unwarranted and beneficent aggression carried the sugar cane to the Caribbean, where it thrived amazingly. The West Indies then became a rival of the East Indies as a treasure-house of tropical wealth and for several centuries the Spanish, Portuguese, Dutch, English, Danes and French fought like wildcats to gain possession of this little nest of islands and the routes leading thereunto. The English finally overcame all these enemies, whether they fought her singly or combined. Great Britain became mistress of the seas and took such Caribbean lands as she wanted. But in the end her continental foes came out ahead, for they rendered her victory valueless. They were defeated in geography but they won in chemistry. Canning boasted that "the New World had been called into existence to redress the balance of the Old." Napoleon might have boasted that he had called in the sugar beet to balance the sugar cane. France was then, as Germany was a century later, threatening to dominate the world. England, then as in the Great War, shut off from the seas the shipping of the aggressive power. France then, like Germany later, felt most keenly the lack of tropical products, chief among which, then but not in the recent crisis, was sugar. The cause of this vital change is that in 1747 Marggraf, a Berlin chemist, discovered that it was possible to extract sugar from beets. There was only a little sugar in the beet root then, some six per cent., and what he got out was dirty and bitter. One of his pupils in 1801 set up a beet sugar factory near Breslau under the patronage of the King of Prussia, but the industry was not a success until Napoleon took it up and in 1810 offered a prize of a million francs for a practical process. How the French did make fun of him for this crazy notion! In a comic paper of that day you will find a cartoon of Napoleon in the nursery beside the cradle of his son and heir, the King of Rome--known to the readers of Rostand as l'Aiglon. The Emperor is squeezing the juice of a beet into his coffee and the nurse has put a beet into the mouth of the infant King, saying: "Suck, dear, suck. Your father says it's sugar." In like manner did the wits ridicule Franklin for fooling with electricity, Rumford for trying to improve chimneys, Parmentier for thinking potatoes were fit to eat, and Jefferson for believing that something might be made of the country west of the Mississippi. In all ages ridicule has been the chief weapon of conservatism. If you want to know what line human progress will take in the future read the funny papers of today and see what they are fighting. The satire of every century from Aristophanes to the latest vaudeville has been directed against those who are trying to make the world wiser or better, against the teacher and the preacher, the scientist and the reformer. In spite of the ridicule showered upon it the despised beet year by year gained in sweetness of heart. The percentage of sugar rose from six to eighteen and by improved methods of extraction became finally as pure and palatable as the sugar of the cane. An acre of German beets produces more sugar than an acre of Louisiana cane. Continental Europe waxed wealthy while the British West Indies sank into decay. As the beets of Europe became sweeter the population of the islands became blacker. Before the war England was paying out $125,000,000 for sugar, and more than two-thirds of this money was going to Germany and Austria-Hungary. Fostered by scientific study, protected by tariff duties, and stimulated by export bounties, the beet sugar industry became one of the financial forces of the world. The English at home, especially the marmalade-makers, at first rejoiced at the idea of getting sugar for less than cost at the expense of her continental rivals. But the suffering colonies took another view of the situation. In 1888 a conference of the powers called at London agreed to stop competing by the pernicious practice of export bounties, but France and the United States refused to enter, so the agreement fell through. Another conference ten years later likewise failed, but when the parvenu beet sugar ventured to invade the historic home of the cane the limit of toleration had been reached. The Council of India put on countervailing duties to protect their homegrown cane from the bounty-fed beet. This forced the calling of a convention at Brussels in 1903 "to equalize the conditions of competition between beet sugar and cane sugar of the various countries," at which the powers agreed to a mutual suppression of bounties. Beet sugar then divided the world's market equally with cane sugar and the two rivals stayed substantially neck and neck until the Great War came. This shut out from England the product of Germany, Austria-Hungary, Belgium, northern France and Russia and took the farmers from their fields. The battle lines of the Central Powers enclosed the land which used to grow a third of the world's supply of sugar. In 1913 the beet and the cane each supplied about nine million tons of sugar. In 1917 the output of cane sugar was 11,200,000 and of beet sugar 5,300,000 tons. Consequently the Old World had to draw upon the New. Cuba, on which the United States used to depend for half its sugar supply, sent over 700,000 tons of raw sugar to England in 1916. The United States sent as much more refined sugar. The lack of shipping interfered with our getting sugar from our tropical dependencies, Hawaii, Porto Rico and the Philippines. The homegrown beets give us only a fifth and the cane of Louisiana and Texas only a fifteenth of the sugar we need. As a result we were obliged to file a claim in advance to get a pound of sugar from the corner grocery and then we were apt to be put off with rock candy, muscovado or honey. Lemon drops proved useful for Russian tea and the "long sweetening" of our forefathers came again into vogue in the form of various syrups. The United States was accustomed to consume almost a fifth of all the sugar produced in the world--and then we could not get it. [Illustration: MAP SHOWING LOCATION OF EUROPEAN BEET SUGAR FACTORIES--ALSO BATTLE LINES AT CLOSE OF 1918 ESTIMATED THAT ONE-THIRD OF WORLDS PRODUCTION BEFORE THE WAR WAS PRODUCED WITHIN BATTLE LINES Courtesy American Sugar Refining Co.] The shortage made us realize how dependent we have become upon sugar. Yet it was, as we have seen, practically unknown to the ancients and only within the present generation has it become an essential factor in our diet. As soon as the chemist made it possible to produce sugar at a reasonable price all nations began to buy it in proportion to their means. Americans, as the wealthiest people in the world, ate the most, ninety pounds a year on the average for every man, woman and child. In other words we ate our weight of sugar every year. The English consumed nearly as much as the Americans; the French and Germans about half as much; the Balkan peoples less than ten pounds per annum; and the African savages none. [Illustration: How the sugar beet has gained enormously in sugar content under chemical control] Pure white sugar is the first and greatest contribution of chemistry to the world's dietary. It is unique in being a single definite chemical compound, sucrose, C_{12}H_{22}O_{11}. All natural nutriments are more or less complex mixtures. Many of them, like wheat or milk or fruit, contain in various proportions all of the three factors of foods, the fats, the proteids and the carbohydrates, as well as water and the minerals and other ingredients necessary to life. But sugar is a simple substance, like water or salt, and like them is incapable of sustaining life alone, although unlike them it is nutritious. In fact, except the fats there is no more nutritious food than sugar, pound for pound, for it contains no water and no waste. It is therefore the quickest and usually the cheapest means of supplying bodily energy. But as may be seen from its formula as given above it contains only three elements, carbon, hydrogen and oxygen, and omits nitrogen and other elements necessary to the body. An engine requires not only coal but also lubricating oil, water and bits of steel and brass to keep it in repair. But as a source of the energy needed in our strenuous life sugar has no equal and only one rival, alcohol. Alcohol is the offspring of sugar, a degenerate descendant that retains but few of the good qualities of its sire and has acquired some evil traits of its own. Alcohol, like sugar, may serve to furnish the energy of a steam engine or a human body. Used as a fuel alcohol has certain advantages, but used as a food it has the disqualification of deranging the bodily mechanism. Even a little alcohol will impair the accuracy and speed of thought and action, while a large quantity, as we all know from observation if not experience, will produce temporary incapacitation. When man feeds on sugar he splits it up by the aid of air into water and carbon dioxide in this fashion: C_{12}H_{22}O_{11} + 12O_{2} --> 11H_{2}O + 12CO_{2} cane sugar oxygen water carbon dioxide When sugar is burned the reaction is just the same. But when the yeast plant feeds on sugar it carries the process only part way and instead of water the product is alcohol, a very different thing, so they say who have tried both as beverages. The yeast or fermentation reaction is this: C_{12}H_{22}O_{11} + H_{2}O --> 4C_{2}H_{6}O + 4CO_{2} cane sugar water alcohol carbon dioxide Alcohol then is the first product of the decomposition of sugar, a dangerous half-way house. The twin product, carbon dioxide or carbonic acid, is a gas of slightly sour taste which gives an attractive tang and effervescence to the beer, wine, cider or champagne. That is to say, one of these twins is a pestilential fellow and the other is decidedly agreeable. Yet for several thousand years mankind took to the first and let the second for the most part escape into the air. But when the chemist appeared on the scene he discovered a way of separating the two and bottling the harmless one for those who prefer it. An increasing number of people were found to prefer it, so the American soda-water fountain is gradually driving Demon Rum out of the civilized world. The brewer nowadays caters to two classes of customers. He bottles up the beer with the alcohol and a little carbonic acid in it for the saloon and he catches the rest of the carbonic acid that he used to waste and sells it to the drug stores for soda-water or uses it to charge some non-alcoholic beer of his own. This catering to rival trades is not an uncommon thing with the chemist. As we have seen, the synthetic perfumes are used to improve the natural perfumes. Cottonseed is separated into oil and meal; the oil going to make margarin and the meal going to feed the cows that produce butter. Some people have been drinking coffee, although they do not like the taste of it, because they want the stimulating effect of its alkaloid, caffein. Other people liked the warmth and flavor of coffee but find that caffein does not agree with them. Formerly one had to take the coffee whole or let it alone. Now one can have his choice, for the caffein is extracted for use in certain popular cold drinks and the rest of the bean sold as caffein-free coffee. Most of the "soft drinks" that are now gradually displacing the hard ones consist of sugar, water and carbonic acid, with various flavors, chiefly the esters of the fatty and aromatic acids, such as I described in a previous chapter. These are still usually made from fruits and spices and in some cases the law or public opinion requires this, but eventually, I presume, the synthetic flavors will displace the natural and then we shall get rid of such extraneous and indigestible matter as seeds, skins and bark. Suppose the world had always been used to synthetic and hence seedless figs, strawberries and blackberries. Suppose then some manufacturer of fig paste or strawberry jam should put in ten per cent. of little round hard wooden nodules, just the sort to get stuck between the teeth or caught in the vermiform appendix. How long would it be before he was sent to jail for adulterating food? But neither jail nor boycott has any reformatory effect on Nature. Nature is quite human in that respect. But you can reform Nature as you can human beings by looking out for heredity and culture. In this way Mother Nature has been quite cured of her bad habit of putting seeds in bananas and oranges. Figs she still persists in adulterating with particles of cellulose as nutritious as sawdust. But we can circumvent the old lady at this. I got on Christmas a package of figs from California without a seed in them. Somebody had taken out all the seeds--it must have been a big job--and then put the figs together again as natural looking as life and very much better tasting. Sugar and alcohol are both found in Nature; sugar in the ripe fruit, alcohol when it begins to decay. But it was the chemist who discovered how to extract them. He first worked with alcohol and unfortunately succeeded. Previous to the invention of the still by the Arabian chemists man could not get drunk as quickly as he wanted to because his liquors were limited to what the yeast plant could stand without intoxication. When the alcoholic content of wine or beer rose to seventeen per cent. at the most the process of fermentation stopped because the yeast plants got drunk and quit "working." That meant that a man confined to ordinary wine or beer had to drink ten or twenty quarts of water to get one quart of the stuff he was after, and he had no liking for water. So the chemist helped him out of this difficulty and got him into worse trouble by distilling the wine. The more volatile part that came over first contained the flavor and most of the alcohol. In this way he could get liquors like brandy and whisky, rum and gin, containing from thirty to eighty per cent. of alcohol. This was the origin of the modern liquor problem. The wine of the ancients was strong enough to knock out Noah and put the companions of Socrates under the table, but it was not until distilled liquors came in that alcoholism became chronic, epidemic and ruinous to whole populations. But the chemist later tried to undo the ruin he had quite inadvertently wrought by introducing alcohol into the world. One of his most successful measures was the production of cheap and pure sugar which, as we have seen, has become a large factor in the dietary of civilized countries. As a country sobers up it takes to sugar as a "self-starter" to provide the energy needed for the strenuous life. A five o'clock candy is a better restorative than a five o'clock highball or even a five o'clock tea, for it is a true nutrient instead of a mere stimulant. It is a matter of common observation that those who like sweets usually do not like alcohol. Women, for instance, are apt to eat candy but do not commonly take to alcoholic beverages. Look around you at a banquet table and you will generally find that those who turn down their wine glasses generally take two lumps in their demi-tasses. We often hear it said that whenever a candy store opens up a saloon in the same block closes up. Our grandmothers used to warn their daughters: "Don't marry a man who does not want sugar in his tea. He is likely to take to drink." So, young man, when next you give a box of candy to your best girl and she offers you some, don't decline it. Eat it and pretend to like it, at least, for it is quite possible that she looked into a physiology and is trying you out. You never can tell what girls are up to. In the army and navy ration the same change has taken place as in the popular dietary. The ration of rum has been mostly replaced by an equivalent amount of candy or marmalade. Instead of the tippling trooper of former days we have "the chocolate soldier." No previous war in history has been fought so largely on sugar and so little on alcohol as the last one. When the war reduced the supply and increased the demand we all felt the sugar famine and it became a mark of patriotism to refuse candy and to drink coffee unsweetened. This, however, is not, as some think, the mere curtailment of a superfluous or harmful luxury, the sacrifice of a pleasant sensation. It is a real deprivation and a serious loss to national nutrition. For there is no reason to think the constantly rising curve of sugar consumption has yet reached its maximum or optimum. Individuals overeat, but not the population as a whole. According to experiments of the Department of Agriculture men doing heavy labor may add three-quarters of a pound of sugar to their daily diet without any deleterious effects. This is at the rate of 275 pounds a year, which is three times the average consumption of England and America. But the Department does not state how much a girl doing nothing ought to eat between meals. Of the 2500 to 3500 calories of energy required to keep a man going for a day the best source of supply is the carbohydrates, that is, the sugars and starches. The fats are more concentrated but are more expensive and less easily assimilable. The proteins are also more expensive and their decomposition products are more apt to clog up the system. Common sugar is almost an ideal food. Cheap, clean, white, portable, imperishable, unadulterated, pleasant-tasting, germ-free, highly nutritious, completely soluble, altogether digestible, easily assimilable, requires no cooking and leaves no residue. Its only fault is its perfection. It is so pure that a man cannot live on it. Four square lumps give one hundred calories of energy. But twenty-five or thirty-five times that amount would not constitute a day's ration, in fact one would ultimately starve on such fare. It would be like supplying an army with an abundance of powder but neglecting to provide any bullets, clothing or food. To make sugar the sole food is impossible. To make it the main food is unwise. It is quite proper for man to separate out the distinct ingredients of natural products--to extract the butter from the milk, the casein from the cheese, the sugar from the cane--but he must not forget to combine them again at each meal with the other essential foodstuffs in their proper proportion. [Illustration: THE RIVAL SUGARS The sugar beet of the north has become a close rival of the sugar cane of the south] [Illustration: INTERIOR OF A SUGAR MILL SHOWING THE MACHINERY FOR CRUSHING CANE TO EXTRACT THE JUICE] [Illustration: Courtesy of American Sugar Refinery Co. VACUUM PANS OF THE AMERICAN SUGAR REFINERY COMPANY In these air-tight vats the water is boiled off from the cane juice under diminished atmospheric pressure until the sugar crystallizes out] Sugar is not a synthetic product and the business of the chemist has been merely to extract and purify it. But this is not so simple as it seems and every sugar factory has had to have its chemist. He has analyzed every mother beet for a hundred years. He has watched every step of the process from the cane to the crystal lest the sucrose should invert to the less sweet and non-crystallizable glucose. He has tested with polarized light every shipment of sugar that has passed through the custom house, much to the mystification of congressmen who have often wondered at the money and argumentation expended in a tariff discussion over the question of the precise angle of rotation of the plane of vibration of infinitesimal waves in a hypothetical ether. The reason for this painstaking is that there are dozens of different sugars, so much alike that they are difficult to separate. They are all composed of the same three elements, C, H and O, and often in the same proportion. Sometimes two sugars differ only in that one has a right-handed and the other a left-handed twist to its molecule. They bear the same resemblance to one another as the two gloves of a pair. Cane sugar and beet sugar are when completely purified the same substance, that is, sucrose, C_{12}H_{22}O_{11}. The brown and straw-colored sugars, which our forefathers used and which we took to using during the war, are essentially the same but have not been so completely freed from moisture and the coloring and flavoring matter of the cane juice. Maple sugar is mostly sucrose. So partly is honey. Candies are made chiefly of sucrose with the addition of glucose, gums or starch, to give them the necessary consistency and of such colors and flavors, natural or synthetic, as may be desired. Practically all candy, even the cheapest, is nowadays free from deleterious ingredients in the manufacture, though it is liable to become contaminated in the handling. In fact sugar is about the only food that is never adulterated. It would be hard to find anything cheaper to add to it that would not be easily detected. "Sanding the sugar," the crime of which grocers are generally accused, is the one they are least likely to be guilty of. Besides the big family of sugars which are all more or less sweet, similar in structure and about equally nutritious, there are, very curiously, other chemical compounds of altogether different composition which taste like sugar but are not nutritious at all. One of these is a coal-tar derivative, discovered accidentally by an American student of chemistry, Ira Remsen, afterward president of Johns Hopkins University, and named by him "saccharin." This has the composition C_{6}H_{4}COSO_{2}NH, and as you may observe from the symbol it contains sulfur (S) and nitrogen (N) and the benzene ring (C_{6}H_{4}) that are not found in any of the sugars. It is several hundred times sweeter than sugar, though it has also a slightly bitter aftertaste. A minute quantity of it can therefore take the place of a large amount of sugar in syrups, candies and preserves, so because it lends itself readily to deception its use in food has been prohibited in the United States and other countries. But during the war, on account of the shortage of sugar, it came again into use. The European governments encouraged what they formerly tried to prevent, and it became customary in Germany or Italy to carry about a package of saccharin tablets in the pocket and drop one or two into the tea or coffee. Such reversals of administrative attitude are not uncommon. When the use of hops in beer was new it was prohibited by British law. But hops became customary nevertheless and now the law requires hops to be used in beer. When workingmen first wanted to form unions, laws were passed to prevent them. But now, in Australia for instance, the laws require workingmen to form unions. Governments naturally tend to a conservative reaction against anything new. It is amusing to turn back to the pure food agitation of ten years ago and read the sensational articles in the newspapers about the poisonous nature of this dangerous drug, saccharin, in view of the fact that it is being used by millions of people in Europe in amounts greater than once seemed to upset the tender stomachs of the Washington "poison squads." But saccharin does not appear to be responsible for any fatalities yet, though people are said to be heartily sick of it. And well they may be, for it is not a substitute for sugar except to the sense of taste. Glucose may correctly be called a substitute for sucrose as margarin for butter, since they not only taste much the same but have about the same food value. But to serve saccharin in the place of sugar is like giving a rubber bone to a dog. It is reported from Europe that the constant use of saccharin gives one eventually a distaste for all sweets. This is quite likely, although it means the reversal within a few years of prehistoric food habits. Mankind has always associated sweetness with food value, for there are few sweet things found in nature except the sugars. We think we eat sugar because it is sweet. But we do not. We eat it because it is good for us. The reason it tastes sweet to us is because it is good for us. So man makes a virtue out of necessity, a pleasure out of duty, which is the essence of ethics. In the ancient days of Ind the great Raja Trishanku possessed an earthly paradise that had been constructed for his delectation by a magician. Therein grew all manner of beautiful flowers, savory herbs and delicious fruits such as had never been known before outside heaven. Of them all the Raja and his harems liked none better than the reed from which they could suck honey. But Indra, being a jealous god, was wroth when he looked down and beheld mere mortals enjoying such delights. So he willed the destruction of the enchanted garden. With drought and tempest it was devastated, with fire and hail, until not a leaf was left of its luxuriant vegetation and the ground was bare as a threshing floor. But the roots of the sugar cane are not destroyed though the stalk be cut down; so when men ventured to enter the desert where once had been this garden of Eden, they found the cane had grown up again and they carried away cuttings of it and cultivated it in their gardens. Thus it happened that the nectar of the gods descended first to monarchs and their favorites, then was spread among the people and carried abroad to other lands until now any child with a penny in his hand may buy of the best of it. So it has been with many things. So may it be with all things. X WHAT COMES FROM CORN The discovery of America dowered mankind with a world of new flora. The early explorers in their haste to gather up gold paid little attention to the more valuable products of field and forest, but in the course of centuries their usefulness has become universally recognized. The potato and tomato, which Europe at first considered as unfit for food or even as poisonous, have now become indispensable among all classes. New World drugs like quinine and cocaine have been adopted into every pharmacopeia. Cocoa is proving a rival of tea and coffee, and even the banana has made its appearance in European markets. Tobacco and chicle occupy the nostrils and jaws of a large part of the human race. Maize and rubber are become the common property of mankind, but still may be called American. The United States alone raises four-fifths of the corn and uses three-fourths of the caoutchouc of the world. All flesh is grass. This may be taken in a dietary as well as a metaphorical sense. The graminaceae provide the greater part of the sustenance of man and beast; hay and cereals, wheat, oats, rye, barley, rice, sugar cane, sorghum and corn. From an American viewpoint the greatest of these, physically and financially, is corn. The corn crop of the United States for 1917, amounting to 3,159,000,000 bushels, brought in more money than the wheat, cotton, potato and rye crops all together. When Columbus reached the West Indies he found the savages playing with rubber balls, smoking incense sticks of tobacco and eating cakes made of a new grain that they called _mahiz_. When Pizarro invaded Peru he found this same cereal used by the natives not only for food but also for making alcoholic liquor, in spite of the efforts of the Incas to enforce prohibition. When the Pilgrim Fathers penetrated into the woods back of Plymouth Harbor they discovered a cache of Indian corn. So throughout the three Americas, from Canada to Peru, corn was king and it has proved worthy to rank with the rival cereals of other continents, the wheat of Europe and the rice of Asia. But food habits are hard to change and for the most part the people of the Old World are still ignorant of the delights of hasty pudding and Indian pudding, of hoe-cake and hominy, of sweet corn and popcorn. I remember thirty years ago seeing on a London stand a heap of dejected popcorn balls labeled "Novel American Confection. Please Try One." But nobody complied with this pitiful appeal but me and I was sorry that I did. Americans used to respond with a shipload of corn whenever an appeal came from famine sufferers in Armenia, Russia, Ireland, India or Austria, but their generosity was chilled when they found that their gift was resented as an insult or as an attempt to poison the impoverished population, who declared that they would rather die than eat it--and some of them did. Our Department of Agriculture sent maize missionaries to Europe with farmers and millers as educators and expert cooks to serve free flapjacks and pones, but the propaganda made little impression and today Americans are urged to eat more of their own corn because the famished families of the war-stricken region will not touch it. Just so the beggars of Munich revolted at potato soup when the pioneer of American food chemists, Bumford, attempted to introduce this transatlantic dish. But here we are not so much concerned with corn foods as we are with its manufactured products. If you split a kernel in two you will find that it consists of three parts: a hard and horny hull on the outside, a small oily and nitrogenous germ at the point, and a white body consisting mostly of starch. Each of these is worked up into various products, as may be seen from the accompanying table. The hull forms bran and may be mixed with the gluten as a cattle food. The corn steeped for several days with sulfurous acid is disintegrated and on being ground the germs are floated off, the gluten or nitrogenous portion washed out, the starch grains settled down and the residue pressed together as oil cake fodder. The refined oil from the germ is marketed as a table or cooking oil under the name of "Mazola" and comes into competition with olive, peanut and cottonseed oil in the making of vegetable substitutes for lard and butter. Inferior grades may be used for soaps or for glycerin and perhaps nitroglycerin. A bushel of corn yields a pound or more of oil. From the corn germ also is extracted a gum called "paragol" that forms an acceptable substitute for rubber in certain uses. The "red rubber" sponges and the eraser tips to pencils may be made of it and it can contribute some twenty per cent. to the synthetic soles of shoes. [Illustration: CORN PRODUCTS] Starch, which constitutes fifty-five per cent. of the corn kernel, can be converted into a variety of products for dietary and industrial uses. As found in corn, potatoes or any other vegetables starch consists of small, round, white, hard grains, tasteless, and insoluble in cold water. But hot water converts it into a soluble, sticky form which may serve for starching clothes or making cornstarch pudding. Carrying the process further with the aid of a little acid or other catalyst it takes up water and goes over into a sugar, dextrose, commonly called "glucose." Expressed in chemical shorthand this reaction is C_{6}H_{10}O_{5} + H_{2}O --> C_{6}H_{12}O_{6} starch water dextrose This reaction is carried out on forty million bushels of corn a year in the United States. The "starch milk," that is, the starch grains washed out from the disintegrated corn kernel by water, is digested in large pressure tanks under fifty pounds of steam with a few tenths of one per cent. of hydrochloric acid until the required degree of conversion is reached. Then the remaining acid is neutralized by caustic soda, and thereby converted into common salt, which in this small amount does not interfere but rather enhances the taste. The product is the commercial glucose or corn syrup, which may if desired be evaporated to a white powder. It is a mixture of three derivatives of starch in about this proportion: Maltose 45 per cent. Dextrose 20 per cent. Dextrin 35 per cent. There are also present three- or four-tenths of one per cent. salt and as much of the corn protein and a variable amount of water. It will be noticed that the glucose (dextrose), which gives name to the whole, is the least of the three ingredients. Maltose, or malt sugar, has the same composition as cane sugar (C_{12}H_{22}O_{11}), but is not nearly so sweet. Dextrin, or starch paste, is not sweet at all. Dextrose or glucose is otherwise known; as grape sugar, for it is commonly found in grapes and other ripe fruits. It forms half of honey and it is one of the two products into which cane sugar splits up when we take it into the mouth. It is not so sweet as cane sugar and cannot be so readily crystallized, which, however, is not altogether a disadvantage. The process of changing starch into dextrose that takes place in the great steam kettles of the glucose factory is essentially the same as that which takes place in the ripening of fruit and in the digestion of starch. A large part of our nutriment, therefore, consists of glucose either eaten as such in ripe fruits or produced in the mouth or stomach by the decomposition of the starch of unripe fruit, vegetables and cereals. Glucose may be regarded as a predigested food. In spite of this well-known fact we still sometimes read "poor food" articles in which glucose is denounced as a dangerous adulterant and even classed as a poison. The other ingredients of commercial glucose, the maltose and dextrin, have of course the same food value as the dextrose, since they are made over into dextrose in the process of digestion. Whether the glucose syrup is fit to eat depends, like anything else, on how it is made. If, as was formerly sometimes the case, sulfuric acid was used to effect the conversion of the starch or sulfurous acid to bleach the glucose and these acids were not altogether eliminated, the product might be unwholesome or worse. Some years ago in England there was a mysterious epidemic of arsenical poisoning among beer drinkers. On tracing it back it was found that the beer had been made from glucose which had been made from sulfuric acid which had been made from sulfur which had been made from a batch of iron pyrites which contained a little arsenic. The replacement of sulfuric acid by hydrochloric has done away with that danger and the glucose now produced is pure. The old recipe for home-made candy called for the addition of a little vinegar to the sugar syrup to prevent "graining." The purpose of the acid was of course to invert part of the cane sugar to glucose so as to keep it from crystallizing out again. The professional candy-maker now uses the corn glucose for that purpose, so if we accuse him of "adulteration" on that ground we must levy the same accusation against our grandmothers. The introduction of glucose into candy manufacture has not injured but greatly increased the sale of sugar for the same purpose. This is not an uncommon effect of scientific progress, for as we have observed, the introduction of synthetic perfumes has stimulated the production of odoriferous flowers and the price of butter has gone up with the introduction of margarin. So, too, there are more weavers employed and they get higher wages than in the days when they smashed up the first weaving machines, and the same is true of printers and typesetting machines. The popular animosity displayed toward any new achievement of applied science is never justified, for it benefits not only the world as a whole but usually even those interests with which it seems at first to conflict. The chemist is an economizer. It is his special business to hunt up waste products and make them useful. He was, for instance, worried over the waste of the cores and skins and scraps that were being thrown away when apples were put up. Apple pulp contains pectin, which is what makes jelly jell, and berries and fruits that are short of it will refuse to "jell." But using these for their flavor he adds apple pulp for pectin and glucose for smoothness and sugar for sweetness and, if necessary, synthetic dyes for color, he is able to put on the market a variety of jellies, jams and marmalades at very low price. The same principle applies here as in the case of all compounded food products. If they are made in cleanly fashion, contain no harmful ingredients and are truthfully labeled there is no reason for objecting to them. But if the manufacturer goes so far as to put strawberry seeds--or hayseed--into his artificial "strawberry jam" I think that might properly be called adulteration, for it is imitating the imperfections of nature, and man ought to be too proud to do that. The old-fashioned open kettle molasses consisted mostly of glucose and other invert sugars together with such cane sugar as could not be crystallized out. But when the vacuum pan was introduced the molasses was impoverished of its sweetness and beet sugar does not yield any molasses. So we now have in its place the corn syrups consisting of about 85 per cent. of glucose and 15 per cent. of sugar flavored with maple or vanillin or whatever we like. It is encouraging to see the bill boards proclaiming the virtues of "Karo" syrup and "Mazola" oil when only a few years ago the products of our national cereal were without honor in their own country. Many other products besides foods are made from corn starch. Dextrin serves in place of the old "gum arabic" for the mucilage of our envelopes and stamps. Another form of dextrin sold as "Kordex" is used to hold together the sand of the cores of castings. After the casting has been made the scorched core can be shaken out. Glucose is used in place of sugar as a filler for cheap soaps and for leather. Altogether more than a hundred different commercial products are now made from corn, not counting cob pipes. Every year the factories of the United States work up over 50,000,000 bushels of corn into 800,000,000 pounds of corn syrup, 600,000,000 pounds of starch, 230,000,000 pounds of corn sugar, 625,000,000 pounds of gluten feed, 90,000,000 pounds of oil and 90,000,000 pounds of oil cake. Two million bushels of cobs are wasted every year in the United States. Can't something be made out of them? This is the question that is agitating the chemists of the Carbohydrate Laboratory of the Department of Agriculture at Washington. They have found it possible to work up the corn cobs into glucose and xylose by heating with acid. But glucose can be more cheaply obtained from other starchy or woody materials and they cannot find a market for the xylose. This is a sort of a sugar but only about half as sweet as that from cane. Who can invent a use for it! More promising is the discovery by this laboratory that by digesting the cobs with hot water there can be extracted about 30 per cent. of a gum suitable for bill posting and labeling. Since the starches and sugars belong to the same class of compounds as the celluloses they also can be acted upon by nitric acid with the production of explosives like guncotton. Nitro-sugar has not come into common use, but nitro-starch is found to be one of safest of the high explosives. On account of the danger of decomposition and spontaneous explosion from the presence of foreign substances the materials in explosives must be of the purest possible. It was formerly thought that tapioca must be imported from Java for making nitro-starch. But during the war when shipping was short, the War Department found that it could be made better and cheaper from our home-grown corn starch. When the war closed the United States was making 1,720,000 pounds of nitro-starch a month for loading hand grenades. So, too, the Post Office Department discovered that it could use mucilage made of corn dextrin as well as that which used to be made from tapioca. This is progress in the right direction. It would be well to divert some of the energetic efforts now devoted to the increase of commerce to the discovery of ways of reducing the need for commerce by the development of home products. There is no merit in simply hauling things around the world. In the last chapter we saw how dextrose or glucose could be converted by fermentation into alcohol. Since corn starch, as we have seen, can be converted into dextrose, it can serve as a source of alcohol. This was, in fact, one of the earliest misuses to which corn was put, and before the war put a stop to it 34,000,000 bushels went into the making of whiskey in the United States every year, not counting the moonshiners' output. But even though we left off drinking whiskey the distillers could still thrive. Mars is more thirsty than Bacchus. The output of whiskey, denatured for industrial purposes, is more than three times what is was before the war, and the price has risen from 30 cents a gallon to 67 cents. This may make it profitable to utilize sugars, starches and cellulose that formerly were out of the question. According to the calculations of the Forest Products Laboratory of Madison it costs from 37 to 44 cents a gallon to make alcohol from corn, but it may be made from sawdust at a cost of from 14 to 20 cents. This is not "wood alcohol" (that is, methyl alcohol, CH_{4}O) such as is made by the destructive distillation of wood, but genuine "grain alcohol" (ethyl alcohol, C_{2}H_{6}O), such as is made by the fermentation of glucose or other sugar. The first step in the process is to digest the sawdust or chips with dilute sulfuric acid under heat and pressure. This converts the cellulose (wood fiber) in large part into glucose ("corn sugar") which may be extracted by hot water in a diffusion battery as in extracting the sugar from beet chips. This glucose solution may then be fermented by yeast and the resulting alcohol distilled off. The process is perfectly practicable but has yet to be proved profitable. But the sulfite liquors of the paper mills are being worked up successfully into industrial alcohol. The rapidly approaching exhaustion of our oil fields which the war has accelerated leads us to look around to see what we can get to take the place of gasoline. One of the most promising of the suggested substitutes is alcohol. The United States is exceptionally rich in mineral oil, but some countries, for instance England, Germany, France and Australia, have little or none. The Australian Advisory Council of Science, called to consider the problem, recommends alcohol for stationary engines and motor cars. Alcohol has the disadvantage of being less volatile than gasoline so it is hard to start up the engine from the cold. But the lower volatility and ignition point of alcohol are an advantage in that it can be put under a pressure of 150 pounds to the square inch. A pound of gasoline contains fifty per cent. more potential energy than a pound of alcohol, but since the alcohol vapor can be put under twice the compression of the gasoline and requires only one-third the amount of air, the thermal efficiency of an alcohol engine may be fifty per cent. higher than that of a gasoline engine. Alcohol also has several other conveniences that can count in its favor. In the case of incomplete combustion the cylinders are less likely to be clogged with carbon and the escaping gases do not have the offensive odor of the gasoline smoke. Alcohol does not ignite so easily as gasoline and the fire is more readily put out, for water thrown upon blazing alcohol dilutes it and puts out the flame while gasoline floats on water and the fire is spread by it. It is possible to increase the inflammability of alcohol by mixing with it some hydrocarbon such as gasoline, benzene or acetylene. In the Taylor-White process the vapor from low-grade alcohol containing 17 per cent. water is passed over calcium carbide. This takes out the water and adds acetylene gas, making a suitable mixture for an internal combustion engine. Alcohol can be made from anything of a starchy, sugary or woody nature, that is, from the main substance of all vegetation. If we start with wood (cellulose) we convert it first into sugar (glucose) and, of course, we could stop here and use it for food instead of carrying it on into alcohol. This provides one factor of our food, the carbohydrate, but by growing the yeast plants on glucose and feeding them with nitrates made from the air we can get the protein and fat. So it is quite possible to live on sawdust, although it would be too expensive a diet for anybody but a millionaire, and he would not enjoy it. Glucose has been made from formaldehyde and this in turn made from carbon, hydrogen and oxygen, so the synthetic production of food from the elements is not such an absurdity as it was thought when Berthelot suggested it half a century ago. The first step in the making of alcohol is to change the starch over into sugar. This transformation is effected in the natural course of sprouting by which the insoluble starch stored up in the seed is converted into the soluble glucose for the sap of the growing plant. This malting process is that mainly made use of in the production of alcohol from grain. But there are other ways of effecting the change. It may be done by heating with acid as we have seen, or according to a method now being developed the final conversion may be accomplished by mold instead of malt. In applying this method, known as the amylo process, to corn, the meal is mixed with twice its weight of water, acidified with hydrochloric acid and steamed. The mash is then cooled down somewhat, diluted with sterilized water and innoculated with the mucor filaments. As the mash molds the starch is gradually changed over to glucose and if this is the product desired the process may be stopped at this point. But if alcohol is wanted yeast is added to ferment the sugar. By keeping it alkaline and treating with the proper bacteria a high yield of glycerin can be obtained. In the fermentation process for making alcoholic liquors a little glycerin is produced as a by-product. Glycerin, otherwise called glycerol, is intermediate between sugar and alcohol. Its molecule contains three carbon atoms, while glucose has six and alcohol two. It is possible to increase the yield of glycerin if desired by varying the form of fermentation. This was desired most earnestly in Germany during the war, for the British blockade shut off the importation of the fats and oils from which the Germans extracted the glycerin for their nitroglycerin. Under pressure of this necessity they worked out a process of getting glycerin in quantity from sugar and, news of this being brought to this country by Dr. Alonzo Taylor, the United States Treasury Department set up a special laboratory to work out this problem. John R. Eoff and other chemists working in this laboratory succeeded in getting a yield of twenty per cent. of glycerin by fermenting black strap molasses or other syrup with California wine yeast. During the fermentation it is necessary to neutralize the acetic acid formed with sodium or calcium carbonate. It was estimated that glycerin could be made from waste sugars at about a quarter of its war-time cost, but it is doubtful whether the process would be profitable at normal prices. We can, if we like, dispense with either yeast or bacteria in the production of glycerin. Glucose syrup suspended in oil under steam pressure with finely divided nickel as a catalyst and treated with nascent hydrogen will take up the hydrogen and be converted into glycerin. But the yield is poor and the process expensive. Food serves substantially the same purpose in the body as fuel in the engine. It provides the energy for work. The carbohydrates, that is the sugars, starches and celluloses, can all be used as fuels and can all--even, as we have seen, the cellulose--be used as foods. The final products, water and carbon dioxide, are in both cases the same and necessarily therefore the amount of energy produced is the same in the body as in the engine. Corn is a good example of the equivalence of the two sources of energy. There are few better foods and no better fuels. I can remember the good old days in Kansas when we had corn to burn. It was both an economy and a luxury, for--at ten cents a bushel--it was cheaper than coal or wood and preferable to either at any price. The long yellow ears, each wrapped in its own kindling, could be handled without crocking the fingers. Each kernel as it crackled sent out a blazing jet of oil and the cobs left a fine bed of coals for the corn popper to be shaken over. Driftwood and the pyrotechnic fuel they make now by soaking sticks in strontium and copper salts cannot compare with the old-fashioned corn-fed fire in beauty and the power of evoking visions. Doubtless such luxury would be condemned as wicked nowadays, but those who have known the calorific value of corn would find it hard to abandon it altogether, and I fancy that the Western farmer's wife, when she has an extra batch of baking to do, will still steal a few ears from the crib. XI SOLIDIFIED SUNSHINE All life and all that life accomplishes depend upon the supply of solar energy stored in the form of food. The chief sources of this vital energy are the fats and the sugars. The former contain two and a quarter times the potential energy of the latter. Both, when completely purified, consist of nothing but carbon, hydrogen and oxygen; elements that are to be found freely everywhere in air and water. So when the sunny southland exports fats and oils, starches and sugar, it is then sending away nothing material but what comes back to it in the next wind. What it is sending to the regions of more slanting sunshine is merely some of the surplus of the radiant energy it has received so abundantly, compacted for convenience into a portable and edible form. In previous chapters I have dealt with some of the uses of cotton, its employment for cloth, for paper, for artificial fibers, for explosives, and for plastics. But I have ignored the thing that cotton is attached to and for which, in the economy of nature, the fibers are formed; that is, the seed. It is as though I had described the aeroplane and ignored the aviator whom it was designed to carry. But in this neglect I am but following the example of the human race, which for three thousand years used the fiber but made no use of the seed except to plant the next crop. Just as mankind is now divided into the two great classes, the wheat-eaters and the rice-eaters, so the ancient world was divided into the wool-wearers and the cotton-wearers. The people of India wore cotton; the Europeans wore wool. When the Greeks under Alexander fought their way to the Far East they were surprised to find wool growing on trees. Later travelers returning from Cathay told of the same marvel and travelers who stayed at home and wrote about what they had not seen, like Sir John Maundeville, misunderstood these reports and elaborated a legend of a tree that bore live lambs as fruit. Here, for instance, is how a French poetical botanist, Delacroix, described it in 1791, as translated from his Latin verse: Upon a stalk is fixed a living brute, A rooted plant bears quadruped for fruit; It has a fleece, nor does it want for eyes, And from its brows two wooly horns arise. The rude and simple country people say It is an animal that sleeps by day And wakes at night, though rooted to the ground, To feed on grass within its reach around. But modern commerce broke down the barrier between East and West. A new cotton country, the best in the world, was discovered in America. Cotton invaded England and after a hard fight, with fists as well as finance, wool was beaten in its chief stronghold. Cotton became King and the wool-sack in the House of Lords lost its symbolic significance. Still two-thirds of the cotton crop, the seed, was wasted and it is only within the last fifty years that methods of using it have been developed to any extent. The cotton crop of the United States for 1917 amounted to about 11,000,000 bales of 500 pounds each. When the Great War broke out and no cotton could be exported to Germany and little to England the South was in despair, for cotton went down to five or six cents a pound. The national Government, regardless of states' rights, was called upon for aid and everybody was besought to "buy a bale." Those who responded to this patriotic appeal were well rewarded, for cotton rose as the war went on and sold at twenty-nine cents a pound. [ILLUSTRATION: PRODUCTS AND USES OF COTTONSEED] But the chemist has added some $150,000,000 a year to the value of the crop by discovering ways of utilizing the cottonseed that used to be thrown away or burned as fuel. The genealogical table of the progeny of the cottonseed herewith printed will give some idea of their variety. If you will examine a cottonseed you will see first that there is a fine fuzz of cotton fiber sticking to it. These linters can be removed by machinery and used for any purpose where length of fiber is not essential. For instance, they may be nitrated as described in previous articles and used for making smokeless powder or celluloid. On cutting open the seed you will observe that it consists of an oily, mealy kernel encased in a thin brown hull. The hulls, amounting to 700 or 900 pounds in a ton of seed, were formerly burned. Now, however, they bring from $4 to $10 a ton because they can be ground up into cattle-feed or paper stock or used as fertilizer. The kernel of the cottonseed on being pressed yields a yellow oil and leaves a mealy cake. This last, mixed with the hulls, makes a good fodder for fattening cattle. Also, adding twenty-five per cent. of the refined cottonseed meal to our war bread made it more nutritious and no less palatable. Cottonseed meal contains about forty per cent. of protein and is therefore a highly concentrated and very valuable feeding stuff. Before the war we were exporting nearly half a million tons of cottonseed meal to Europe, chiefly to Germany and Denmark, where it is used for dairy cows. The British yeoman, his country's pride, has not yet been won over to the use of any such newfangled fodder and consequently the British manufacturer could not compete with his continental rivals in the seed-crushing business, for he could not dispose of his meal-cake by-product as did they. [Illustration: Photo by Press Illustrating Service Cottonseed Oil As It Is Squeezed From The Seed By The Presses] [Illustration: Photo by Press Illustrating Service Cottonseed Oil As It Comes From The Compressors Flowing Out Of The Faucets When cold it is firm and white like lard] Let us now turn to the most valuable of the cottonseed products, the oil. The seed contains about twenty per cent. of oil, most of which can be squeezed out of the hot seeds by hydraulic pressure. It comes out as a red liquid of a disagreeable odor. This is decolorized, deodorized and otherwise purified in various ways: by treatment with alkalies or acids, by blowing air and steam through it, by shaking up with fuller's earth, by settling and filtering. The refined product is a yellow oil, suitable for table use. Formerly, on account of the popular prejudice against any novel food products, it used to masquerade as olive oil. Now, however, it boldly competes with its ancient rival in the lands of the olive tree and America ships some 700,000 barrels of cottonseed oil a year to the Mediterranean. The Turkish Government tried to check the spread of cottonseed oil by calling it an adulterant and prohibiting its mixture with olive oil. The result was that the sale of Turkish olive oil fell off because people found its flavor too strong when undiluted. Italy imports cottonseed oil and exports her olive oil. Denmark imports cottonseed meal and margarine and exports her butter. Northern nations are accustomed to hard fats and do not take to oils for cooking or table use as do the southerners. Butter and lard are preferred to olive oil and ghee. But this does not rule out cottonseed. It can be combined with the hard fats of animal or vegetable origin in margarine or it may itself be hardened by hydrogen. To understand this interesting reaction which is profoundly affecting international relations it will be necessary to dip into the chemistry of the subject. Here are the symbols of the chief ingredients of the fats and oils. Please look at them. Linoleic acid C_{18}H_{32}O_{2} Oleic acid C_{18}H_{34}O_{2} Stearic acid C_{18}H_{36}O_{2} Don't skip these because you have not studied chemistry. That's why I am giving them to you. If you had studied chemistry you would know them without my telling. Just examine them and you will discover the secret. You will see that all three are composed of the same elements, carbon, hydrogen, and oxygen. Notice next the number of atoms in each element as indicated by the little low figures on the right of each letter. You observe that all three contain the same number of atoms of carbon and oxygen but differ in the amount of hydrogen. This trifling difference in composition makes a great difference in behavior. The less the hydrogen the lower the melting point. Or to say the same thing in other words, fatty substances low in hydrogen are apt to be liquids and those with a full complement of hydrogen atoms are apt to be solids at the ordinary temperature of the air. It is common to call the former "oils" and the latter "fats," but that implies too great a dissimilarity, for the distinction depends on whether we are living in the tropics or the arctic. It is better, therefore, to lump them all together and call them "soft fats" and "hard fats," respectively. Fats of the third order, the stearic group, are called "saturated" because they have taken up all the hydrogen they can hold. Fats of the other two groups are called "unsaturated." The first, which have the least hydrogen, are the most eager for more. If hydrogen is not handy they will take up other things, for instance oxygen. Linseed oil, which consists largely, as the name implies, of linoleic acid, will absorb oxygen on exposure to the air and become hard. That is why it is used in painting. Such oils are called "drying" oils, although the hardening process is not really drying, since they contain no water, but is oxidation. The "semi-drying oils," those that will harden somewhat on exposure to the air, include the oils of cottonseed, corn, sesame, soy bean and castor bean. Olive oil and peanut oil are "non-drying" and contain oleic compounds (olein). The hard fats, such as stearin, palmitin and margarin, are mostly of animal origin, tallow and lard, though coconut and palm oil contain a large proportion of such saturated compounds. Though the chemist talks of the fatty "acids," nobody else would call them so because they are not sour. But they do behave like the acids in forming salts with bases. The alkali salts of the fatty acids are known to us as soaps. In the natural fats they exist not as free acids but as salts of an organic base, glycerin, as I explained in a previous chapter. The natural fats and oils consist of complex mixtures of the glycerin compounds of these acids (known as olein, stearin, etc.), as well as various others of a similar sort. If you will set a bottle of salad oil in the ice-box you will see it separate into two parts. The white, crystalline solid that separates out is largely stearin. The part that remains liquid is largely olein. You might separate them by filtering it cold and if then you tried to sell the two products you would find that the hard fat would bring a higher price than the oil, either for food or soap. If you tried to keep them you would find that the hard fat kept neutral and "sweet" longer than the other. You may remember that the perfumes (as well as their odorous opposites) were mostly unsaturated compounds. So we find that it is the free and unsaturated fatty acids that cause butter and oil to become rank and rancid. Obviously, then, we could make money if we could turn soft, unsaturated fats like olein into hard, saturated fats like stearin. Referring to the symbols we see that all that is needed to effect the change is to get the former to unite with hydrogen. This requires a little coaxing. The coaxer is called a catalyst. A catalyst, as I have previously explained, is a substance that by its mere presence causes the union of two other substances that might otherwise remain separate. For that reason the catalyst is referred to as "a chemical parson." Finely divided metals have a strong catalytic action. Platinum sponge is excellent but too expensive. So in this case nickel is used. A nickel salt mixed with charcoal or pumice is reduced to the metallic state by heating in a current of hydrogen. Then it is dropped into the tank of oil and hydrogen gas is blown through. The hydrogen may be obtained by splitting water into its two components, hydrogen and oxygen, by means of the electrical current, or by passing steam over spongy iron which takes out the oxygen. The stream of hydrogen blown through the hot oil converts the linoleic acid to oleic and then the oleic into stearic. If you figured up the weights from the symbols given above you would find that it takes about one pound of hydrogen to convert a hundred pounds of olein to stearin and the cost is only about one cent a pound. The nickel is unchanged and is easily separated. A trace of nickel may remain in the product, but as it is very much less than the amount dissolved when food is cooked in nickel-plated vessels it cannot be regarded as harmful. Even more unsaturated fats may be hydrogenated. Fish oil has hitherto been almost unusable because of its powerful and persistent odor. This is chiefly due to a fatty acid which properly bears the uneuphonious name of clupanodonic acid and has the composition of C_{18}H_{28}O_{2}. By comparing this with the symbol of the odorless stearic acid, C_{18}H_{36}O_{2}, you will see that all the rank fish oil lacks to make it respectable is eight hydrogen atoms. A Japanese chemist, Tsujimoto, has discovered how to add them and now the reformed fish oil under the names of "talgol" and "candelite" serves for lubricant and even enters higher circles as a soap or food. This process of hardening fats by hydrogenation resulted from the experiments of a French chemist, Professor Sabatier of Toulouse, in the last years of the last century, but, as in many other cases, the Germans were the first to take it up and profit by it. Before the war the copra or coconut oil from the British Asiatic colonies of India, Ceylon and Malaya went to Germany at the rate of $15,000,000 a year. The palm kernels grown in British West Africa were shipped, not to Liverpool, but to Hamburg, $19,000,000 worth annually. Here the oil was pressed out and used for margarin and the residual cake used for feeding cows produced butter or for feeding hogs produced lard. Half of the copra raised in the British possessions was sent to Germany and half of the oil from it was resold to the British margarin candle and soap makers at a handsome profit. The British chemists were not blind to this, but they could do nothing, first because the English politician was wedded to free trade, second, because the English farmer would not use oil cake for his stock. France was in a similar situation. Marseilles produced 15,500,000 gallons of oil from peanuts grown largely in the French African colonies--but shipped the oil-cake on to Hamburg. Meanwhile the Germans, in pursuit of their policy of attaining economic independence, were striving to develop their own tropical territory. The subjects of King George who because they had the misfortune to live in India were excluded from the British South African dominions or mistreated when they did come, were invited to come to German East Africa and set to raising peanuts in rivalry to French Senegal and British Coromandel. Before the war Germany got half of the Egyptian cottonseed and half of the Philippine copra. That is one of the reasons why German warships tried to check Dewey at Manila in 1898 and German troops tried to conquer Egypt in 1915. But the tide of war set the other way and the German plantations of palmnuts and peanuts in Africa have come into British possession and now the British Government is starting an educational campaign to teach their farmers to feed oil cake like the Germans and their people to eat peanuts like the Americans. The Germans shut off from the tropical fats supply were hard up for food and for soap, for lubricants and for munitions. Every person was given a fat card that reduced his weekly allowance to the minimum. Millers were required to remove the germs from their cereals and deliver them to the war department. Children were set to gathering horse-chestnuts, elderberries, linden-balls, grape seeds, cherry stones and sunflower heads, for these contain from six to twenty per cent. of oil. Even the blue-bottle fly--hitherto an idle creature for whom Beelzebub found mischief--was conscripted into the national service and set to laying eggs by the billion on fish refuse. Within a few days there is a crop of larvae which, to quote the "Chemische Zentralblatt," yields forty-five grams per kilogram of a yellow oil. This product, we should hope, is used for axle-grease and nitroglycerin, although properly purified it would be as nutritious as any other--to one who has no imagination. Driven to such straits Germany would have given a good deal for one of those tropical islands that we are so careless about. It might have been supposed that since the United States possessed the best land in the world for the production of cottonseed, coconuts, peanuts, and corn that it would have led all other countries in the utilization of vegetable oils for food. That this country has not so used its advantage is due to the fact that the new products have not merely had to overcome popular conservatism, ignorance and prejudice--hard things to fight in any case--but have been deliberately checked and hampered by the state and national governments in defense of vested interests. The farmer vote is a power that no politician likes to defy and the dairy business in every state was thoroughly organized. In New York the oleomargarin industry that in 1879 was turning out products valued at more than $5,000,000 a year was completely crushed out by state legislation.[2] The output of the United States, which in 1902 had risen to 126,000,000 pounds, was cut down to 43,000,000 pounds in 1909 by federal legislation. According to the disingenuous custom of American lawmakers the Act of 1902 was passed through Congress as a "revenue measure," although it meant a loss to the Government of more than three million dollars a year over what might be produced by a straight two cents a pound tax. A wholesale dealer in oleomargarin was made to pay a higher license than a wholesale liquor dealer. The federal law put a tax of ten cents a pound on yellow oleomargarin and a quarter of a cent a pound on the uncolored. But people--doubtless from pure prejudice--prefer a yellow spread for their bread, so the economical housewife has to work over her oleomargarin with the annatto which is given to her when she buys a package or, if the law prohibits this, which she is permitted to steal from an open box on the grocer's counter. A plausible pretext for such legislation is afforded by the fact that the butter substitutes are so much like butter that they cannot be easily distinguished from it unless the use of annatto is permitted to butter and prohibited to its competitors. Fradulent sales of substitutes of any kind ought to be prevented, but the recent pure food legislation in America has shown that it is possible to secure truthful labeling without resorting to such drastic measures. In Europe the laws against substitution were very strict, but not devised to restrict the industry. Consequently the margarin output of Germany doubled in the five years preceding the war and the output of England tripled. In Denmark the consumption of margarin rose from 8.8 pounds per capita in 1890 to 32.6 pounds in 1912. Yet the butter business, Denmark's pride, was not injured, and Germany and England imported more butter than ever before. Now that the price of butter in America has gone over the seventy-five cent mark Congress may conclude that it no longer needs to be protected against competition. The "compound lards" or "lard compounds," consisting usually of cottonseed oil and oleo-stearin, although the latter may now be replaced by hardened oil, met with the same popular prejudice and attempted legislative interference, but succeeded more easily in coming into common use under such names as "Cottosuet," "Kream Krisp," "Kuxit," "Korno," "Cottolene" and "Crisco." Oleomargarin, now generally abbreviated to margarin, originated, like many other inventions, in military necessity. The French Government in 1869 offered a prize for a butter substitute for the army that should be cheaper and better than butter in that it did not spoil so easily. The prize was won by a French chemist, Mége-Mouries, who found that by chilling beef fat the solid stearin could be separated from an oil (oleo) which was the substantially same as that in milk and hence in butter. Neutral lard acts the same. This discovery of how to separate the hard and soft fats was followed by improved methods for purifying them and later by the process for converting the soft into the hard fats by hydrogenation. The net result was to put into the hands of the chemist the ability to draw his materials at will from any land and from the vegetable and animal kingdoms and to combine them as he will to make new fat foods for every use; hard for summer, soft for winter; solid for the northerners and liquid for the southerners; white, yellow or any other color, and flavored to suit the taste. The Hindu can eat no fat from the sacred cow; the Mohammedan and the Jew can eat no fat from the abhorred pig; the vegetarian will touch neither; other people will take both. No matter, all can be accommodated. All the fats and oils, though they consist of scores of different compounds, have practically the same food value when freed from the extraneous matter that gives them their characteristic flavors. They are all practically tasteless and colorless. The various vegetable and animal oils and fats have about the same digestibility, 98 per cent.,[3] and are all ordinarily completely utilized in the body, supplying it with two and a quarter times as much energy as any other food. It does not follow, however, that there is no difference in the products. The margarin men accuse butter of harboring tuberculosis germs from which their product, because it has been heated or is made from vegetable fats, is free. The butter men retort that margarin is lacking in vitamines, those mysterious substances which in minute amounts are necessary for life and especially for growth. Both the claim and the objection lose a large part of their force where the margarin, as is customarily the case, is mixed with butter or churned up with milk to give it the familiar flavor. But the difficulty can be easily overcome. The milk used for either butter or margarin should be free or freed from disease germs. If margarin is altogether substituted for butter, the necessary vitamines may be sufficiently provided by milk, eggs and greens. Owing to these new processes all the fatty substances of all lands have been brought into competition with each other. In such a contest the vegetable is likely to beat the animal and the southern to win over the northern zones. In Europe before the war the proportion of the various ingredients used to make butter substitutes was as follows: AVERAGE COMPOSITION OF EUROPEAN MARGARIN Per Cent. Animal hard fats 25 Vegetable hard fats 35 Copra 29 Palm-kernel 6 Vegetable soft fats 26 Cottonseed 13 Peanut 6 Sesame 6 Soya-bean 1 Water, milk, salt 14 ___ 100 This is not the composition of any particular brand but the average of them all. The use of a certain amount of the oil of the sesame seed is required by the laws of Germany and Denmark because it can be easily detected by a chemical color test and so serves to prevent the margarin containing it from being sold as butter. "Open sesame!" is the password to these markets. Remembering that margarin originally was made up entirely of animal fats, soft and hard, we can see from the above figures how rapidly they are being displaced by the vegetable fats. The cottonseed and peanut oils have replaced the original oleo oil and the tropical oils from the coconut (copra) and African palm are crowding out the animal hard fats. Since now we can harden at will any of the vegetable oils it is possible to get along altogether without animal fats. Such vegetable margarins were originally prepared for sale in India, but proved unexpectedly popular in Europe, and are now being introduced into America. They are sold under various trade names suggesting their origin, such as "palmira," "palmona," "milkonut," "cocose," "coconut oleomargarin" and "nucoa nut margarin." The last named is stated to be made of coconut oil (for the hard fat) and peanut oil (for the soft fat), churned up with a culture of pasteurized milk (to impart the butter flavor). The law requires such a product to be branded "oleomargarine" although it is not. Such cases of compulsory mislabeling are not rare. You remember the "Pigs is Pigs" story. Peanut butter has won its way into the American menu without any camouflage whatever, and as a salad oil it is almost equally frank about its lowly origin. This nut, which grows on a vine instead of a tree, and is dug from the ground like potatoes instead of being picked with a pole, goes by various names according to locality, peanuts, ground-nuts, monkey-nuts, arachides and goobers. As it takes the place of cotton oil in some of its products so it takes its place in the fields and oilmills of Texas left vacant by the bollweevil. The once despised peanut added some $56,000,000 to the wealth of the South in 1916. The peanut is rich in the richest of foods, some 50 per cent. of oil and 30 per cent. of protein. The latter can be worked up into meat substitutes that will make the vegetarian cease to envy his omnivorous neighbor. Thanks largely to the chemist who has opened these new fields of usefulness, the peanut-raiser got $1.25 a bushel in 1917 instead of the 30 cents that he got four years before. It would be impossible to enumerate all the available sources of vegetable oils, for all seeds and nuts contain more or less fatty matter and as we become more economical we shall utilize of what we now throw away. The germ of the corn kernel, once discarded in the manufacture of starch, now yields a popular table oil. From tomato seeds, one of the waste products of the canning factory, can be extracted 22 per cent. of an edible oil. Oats contain 7 per cent. of oil. From rape seed the Japanese get 20,000 tons of oil a year. To the sources previously mentioned may be added pumpkin seeds, poppy seeds, raspberry seeds, tobacco seeds, cockleburs, hazelnuts, walnuts, beechnuts and acorns. The oil-bearing seeds of the tropics are innumerable and will become increasingly essential to the inhabitants of northern lands. It was the realization of this that brought on the struggle of the great powers for the possession of tropical territory which, for years before, they did not think worth while raising a flag over. No country in the future can consider itself safe unless it has secure access to such sources. We had a sharp lesson in this during the war. Palm oil, it seems, is necessary for the manufacture of tinplate, an industry that was built up in the United States by the McKinley tariff. The British possessions in West Africa were the chief source of palm oil and the Germans had the handling of it. During the war the British Government assumed control of the palm oil products of the British and German colonies and prohibited their export to other countries than England. Americans protested and beseeched, but in vain. The British held, quite correctly, that they needed all the oil they could get for food and lubrication and nitroglycerin. But the British also needed canned meat from America for their soldiers and when it was at length brought to their attention that the packers could not ship meat unless they had cans and that cans could not be made without tin and that tin could not be made without palm oil the British Government consented to let us buy a little of their palm oil. The lesson is that of Voltaire's story, "Candide," "Let us cultivate our own garden"--and plant a few palm trees in it--also rubber trees, but that is another story. The international struggle for oil led to the partition of the Pacific as the struggle for rubber led to the partition of Africa. Theodor Weber, as Stevenson says, "harried the Samoans" to get copra much as King Leopold of Belgium harried the Congoese to get caoutchouc. It was Weber who first fully realized that the South Sea islands, formerly given over to cannibals, pirates and missionaries, might be made immensely valuable through the cultivation of the coconut palms. When the ripe coconut is split open and exposed to the sun the meat dries up and shrivels and in this form, called "copra," it can be cut out and shipped to the factory where the oil is extracted and refined. Weber while German Consul in Samoa was also manager of what was locally known as "the long-handled concern" (_Deutsche Handels und Plantagen Gesellschaft der Südsee Inseln zu Hamburg_), a pioneer commercial and semi-official corporation that played a part in the Pacific somewhat like the British Hudson Bay Company in Canada or East India Company in Hindustan. Through the agency of this corporation on the start Germany acquired a virtual monopoly of the transportation and refining of coconut oil and would have become the dominant power in the Pacific if she had not been checked by force of arms. In Apia Bay in 1889 and again in Manila Bay in 1898 an American fleet faced a German fleet ready for action while a British warship lay between. So we rescued the Philippines and Samoa from German rule and in 1914 German power was eliminated from the Pacific. During the ten years before the war, the production of copra in the German islands more than doubled and this was only the beginning of the business. Now these islands have been divided up among Australia, New Zealand and Japan, and these countries are planning to take care of the copra. But although we get no extension of territory from the war we still have the Philippines and some of the Samoan Islands, and these are capable of great development. From her share of the Samoan Islands Germany got a million dollars' worth of copra and we might get more from ours. The Philippines now lead the world in the production of copra, but Java is a close second and Ceylon not far behind. If we do not look out we will be beaten both by the Dutch and the British, for they are undertaking the cultivation of the coconut on a larger scale and in a more systematic way. According to an official bulletin of the Philippine Government a coconut plantation should bring in "dividends ranging from 10 to 75 per cent. from the tenth to the hundredth year." And this being printed in 1913 figured the price of copra at 3-1/2 cents, whereas it brought 4-1/2 cents in 1918, so the prospect is still more encouraging. The copra is half fat and can be cheaply shipped to America, where it can be crushed in the southern oilmills when they are not busy on cottonseed or peanuts. But even this cost of transportation can be reduced by extracting the oil in the islands and shipping it in bulk like petroleum in tank steamers. In the year ending June, 1918, the United States imported from the Philippines 155,000,000 pounds of coconut oil worth $18,000,000 and 220,000,000 pounds of copra worth $10,000,000. But this was about half our total importations; the rest of it we had to get from foreign countries. Panama palms may give us a little relief from this dependence on foreign sources. In 1917 we imported 19,000,000 whole coconuts from Panama valued at $700,000. [Illustration: SPLITTING COCONUTS ON THE ISLAND OF TAHITI After drying in the sun the meat is picked and the oil extracted for making coconut butter] [Illustration: From "America's Munitions" THE ELECTRIC CURRENT PASSING THROUGH SALT WATER IN THESE CELLS DECOMPOSES THE SALT INTO CAUSTIC SODA AND CHLORINE GAS There were eight rooms like this in the Edgewood plant, capable of producing 200,000 pounds of chlorine a day] A new form of fat that has rapidly come into our market is the oil of the soya or soy bean. In 1918 we imported over 300,000,000 pounds of soy-bean oil, mostly from Manchuria. The oil is used in manufacture of substitutes for butter, lard, cheese, milk and cream, as well as for soap and paint. The soy-bean can be raised in the United States wherever corn can be grown and provides provender for man and beast. The soy meal left after the extraction of the oil makes a good cattle food and the fermented juice affords the shoya sauce made familiar to us through the popularity of the chop-suey restaurants. As meat and dairy products become scarcer and dearer we shall become increasingly dependent upon the vegetable fats. We should therefore devise means of saving what we now throw away, raise as much as we can under our own flag, keep open avenues for our foreign supply and encourage our cooks to make use of the new products invented by our chemists. CHAPTER XII FIGHTING WITH FUMES The Germans opened the war using projectiles seventeen inches in diameter. They closed it using projectiles one one-hundred millionth of an inch in diameter. And the latter were more effective than the former. As the dimensions were reduced from molar to molecular the battle became more intense. For when the Big Bertha had shot its bolt, that was the end of it. Whomever it hit was hurt, but after that the steel fragments of the shell lay on the ground harmless and inert. The men in the dugouts could hear the shells whistle overhead without alarm. But the poison gas could penetrate where the rifle ball could not. The malignant molecules seemed to search out their victims. They crept through the crevices of the subterranean shelters. They hunted for the pinholes in the face masks. They lay in wait for days in the trenches for the soldiers' return as a cat watches at the hole of a mouse. The cannon ball could be seen and heard. The poison gas was invisible and inaudible, and sometimes even the chemical sense which nature has given man for his protection, the sense of smell, failed to give warning of the approach of the foe. The smaller the matter that man can deal with the more he can get out of it. So long as man was dependent for power upon wind and water his working capacity was very limited. But as soon as he passed over the border line from physics into chemistry and learned how to use the molecule, his efficiency in work and warfare was multiplied manifold. The molecular bombardment of the piston by steam or the gases of combustion runs his engines and propels his cars. The first man who wanted to kill another from a safe distance threw the stone by his arm's strength. David added to his arm the centrifugal force of a sling when he slew Goliath. The Romans improved on this by concentrating in a catapult the strength of a score of slaves and casting stone cannon balls to the top of the city wall. But finally man got closer to nature's secret and discovered that by loosing a swarm of gaseous molecules he could throw his projectile seventy-five miles and then by the same force burst it into flying fragments. There is no smaller projectile than the atom unless our belligerent chemists can find a way of using the electron stream of the cathode ray. But this so far has figured only in the pages of our scientific romancers and has not yet appeared on the battlefield. If, however, man could tap the reservoir of sub-atomic energy he need do no more work and would make no more war, for unlimited powers of construction and destruction would be at his command. The forces of the infinitesimal are infinite. The reason why a gas is so active is because it is so egoistic. Psychologically interpreted, a gas consists of particles having the utmost aversion to one another. Each tries to get as far away from every other as it can. There is no cohesive force; no attractive impulse; nothing to draw them together except the all too feeble power of gravitation. The hotter they get the more they try to disperse and so the gas expands. The gas represents the extreme of individualism as steel represents the extreme of collectivism. The combination of the two works wonders. A hot gas in a steel cylinder is the most powerful agency known to man, and by means of it he accomplishes his greatest achievements in peace or war time. The projectile is thrown from the gun by the expansive force of the gases released from the powder and when it reaches its destination it is blown to pieces by the same force. This is the end of it if it is a shell of the old-fashioned sort, for the gases of combustion mingle harmlessly with the air of which they are normal constituents. But if it is a poison gas shell each molecule as it is released goes off straight into the air with a speed twice that of the cannon ball and carries death with it. A man may be hit by a heavy piece of lead or iron and still survive, but an unweighable amount of lethal gas may be fatal to him. Most of the novelties of the war were merely extensions of what was already known. To increase the caliber of a cannon from 38 to 42 centimeters or its range from 30 to 75 miles does indeed make necessary a decided change in tactics, but it is not comparable to the revolution effected by the introduction of new weapons of unprecedented power such as airplanes, submarines, tanks, high explosives or poison gas. If any army had been as well equipped with these in the beginning as all armies were at the end it might easily have won the war. That is to say, if the general staff of any of the powers had had the foresight and confidence to develop and practise these modes of warfare on a large scale in advance it would have been irresistible against an enemy unprepared to meet them. But no military genius appeared on either side with sufficient courage and imagination to work out such schemes in secret before trying them out on a small scale in the open. Consequently the enemy had fair warning and ample time to learn how to meet them and methods of defense developed concurrently with methods of attack. For instance, consider the motor fortresses to which Ludendorff ascribes his defeat. The British first sent out a few clumsy tanks against the German lines. Then they set about making a lot of stronger and livelier ones, but by the time these were ready the Germans had field guns to smash them and chain fences with concrete posts to stop them. On the other hand, if the Germans had followed up their advantage when they first set the cloud of chlorine floating over the battlefield of Ypres they might have won the war in the spring of 1915 instead of losing it in the fall of 1918. For the British were unprepared and unprotected against the silent death that swept down upon them on the 22nd of April, 1915. What happened then is best told by Sir Arthur Conan Doyle in his "History of the Great War." From the base of the German trenches over a considerable length there appeared jets of whitish vapor, which gathered and swirled until they settled into a definite low cloud-bank, greenish-brown below and yellow above, where it reflected the rays of the sinking sun. This ominous bank of vapor, impelled by a northern breeze, drifted swiftly across the space which separated the two lines. The French troops, staring over the top of their parapet at this curious screen which ensured them a temporary relief from fire, were observed suddenly to throw up their hands, to clutch at their throats, and to fall to the ground in the agonies of asphyxiation. Many lay where they had fallen, while their comrades, absolutely helpless against this diabolical agency, rushed madly out of the mephitic mist and made for the rear, over-running the lines of trenches behind them. Many of them never halted until they had reached Ypres, while others rushed westwards and put the canal between themselves and the enemy. The Germans, meanwhile, advanced, and took possession of the successive lines of trenches, tenanted only by the dead garrisons, whose blackened faces, contorted figures, and lips fringed with the blood and foam from their bursting lungs, showed the agonies in which they had died. Some thousands of stupefied prisoners, eight batteries of French field-guns, and four British 4.7's, which had been placed in a wood behind the French position, were the trophies won by this disgraceful victory. Under the shattering blow which they had received, a blow particularly demoralizing to African troops, with their fears of magic and the unknown, it was impossible to rally them effectually until the next day. It is to be remembered in explanation of this disorganization that it was the first experience of these poison tactics, and that the troops engaged received the gas in a very much more severe form than our own men on the right of Langemarck. For a time there was a gap five miles broad in the front of the position of the Allies, and there were many hours during which there was no substantial force between the Germans and Ypres. They wasted their time, however, in consolidating their ground, and the chance of a great coup passed forever. They had sold their souls as soldiers, but the Devil's price was a poor one. Had they had a corps of cavalry ready, and pushed them through the gap, it would have been the most dangerous moment of the war. A deserter had come over from the German side a week before and told them that cylinders of poison gas had been laid in the front trenches, but no one believed him or paid any attention to his tale. War was then, in the Englishman's opinion, a gentleman's game, the royal sport, and poison was prohibited by the Hague rules. But the Germans were not playing the game according to the rules, so the British soldiers were strangled in their own trenches and fell easy victims to the advancing foe. Within half an hour after the gas was turned on 80 per cent. of the opposing troops were knocked out. The Canadians, with wet handkerchiefs over their faces, closed in to stop the gap, but if the Germans had been prepared for such success they could have cleared the way to the coast. But after such trials the Germans stopped the use of free chlorine and began the preparation of more poisonous gases. In some way that may not be revealed till the secret history of the war is published, the British Intelligence Department obtained a copy of the lecture notes of the instructions to the German staff giving details of the new system of gas warfare to be started in December. Among the compounds named was phosgene, a gas so lethal that one part in ten thousand of air may be fatal. The antidote for it is hexamethylene tetramine. This is not something the soldier--or anybody else--is accustomed to carry around with him, but the British having had a chance to cram up in advance on the stolen lecture notes were ready with gas helmets soaked in the reagent with the long name. The Germans rejoiced when gas bombs took the place of bayonets because this was a field in which intelligence counted for more than brute force and in which therefore they expected to be supreme. As usual they were right in their major premise but wrong in their conclusion, owing to the egoism of their implicit minor premise. It does indeed give the advantage to skill and science, but the Germans were beaten at their own game, for by the end of the war the United States was able to turn out toxic gases at a rate of 200 tons a day, while the output of Germany or England was only about 30 tons. A gas plant was started at Edgewood, Maryland, in November, 1917. By March it was filling shell and before the war put a stop to its activities in the fall it was producing 1,300,000 pounds of chlorine, 1,000,000 pounds of chlorpicrin, 1,300,000 pounds of phosgene and 700,000 pounds of mustard gas a month. Chlorine, the first gas used, is unpleasantly familiar to every one who has entered a chemical laboratory or who has smelled the breath of bleaching powder. It is a greenish-yellow gas made from common salt. The Germans employed it at Ypres by laying cylinders of the liquefied gas in the trenches, about a yard apart, and running a lead discharge pipe over the parapet. When the stop cocks are turned the gas streams out and since it is two and a half times as heavy as air it rolls over the ground like a noisome mist. It works best when the ground slopes gently down toward the enemy and when the wind blows in that direction at a rate between four and twelve miles an hour. But the wind, being strictly neutral, may change its direction without warning and then the gases turn back in their flight and attack their own side, something that rifle bullets have never been known to do. [Illustration: © International Film Service GERMANS STARTING A GAS ATTACK ON THE RUSSIAN LINES Behind the cylinders from which the gas streams are seen three lines of German troops waiting to attack. The photograph was taken from above by a Russian airman] [Illustration: © Press Illustrating Service FILLING THE CANNISTERS OF GAS MASKS WITH CHARCOAL MADE FROM FRUIT PITS IN LONG ISLAND CITY] Because free chlorine would not stay put and was dependent on the favor of the wind for its effect, it was later employed, not as an elemental gas, but in some volatile liquid that could be fired in a shell and so released at any particular point far back of the front trenches. The most commonly used of these compounds was phosgene, which, as the reader can see by inspection of its formula, COCl_{2}, consists of chlorine (Cl) combined with carbon monoxide (CO), the cause of deaths from illuminating gas. These two poisonous gases, chlorine and carbon monoxide, when mixed together, will not readily unite, but if a ray of sunlight falls upon the mixture they combine at once. For this reason John Davy, who discovered the compound over a hundred years ago, named it phosgene, that is, "produced by light." The same roots recur in hydrogen, so named because it is "produced from water," and phosphorus, because it is a "light-bearer." In its modern manufacture the catalyzer or instigator of the combination is not sunlight but porous carbon. This is packed in iron boxes eight feet long, through which the mixture of the two gases was forced. Carbon monoxide may be made by burning coke with a supply of air insufficient for complete combustion, but in order to get the pure gas necessary for the phosgene common air was not used, but instead pure oxygen extracted from it by a liquid air plant. Phosgene is a gas that may be condensed easily to a liquid by cooling it down to 46 degrees Fahrenheit. A mixture of three-quarters chlorine with one-quarter phosgene has been found most effective. By itself phosgene has an inoffensive odor somewhat like green corn and so may fail to arouse apprehension until a toxic concentration is reached. But even small doses have such an effect upon the heart action for days afterward that a slight exertion may prove fatal. The compound manufactured in largest amount in America was chlorpicrin. This, like the others, is not so unfamiliar as it seems. As may be seen from its formula, CCl_{3}NO_{2}, it is formed by joining the nitric acid radical (NO_{2}), found in all explosives, with the main part of chloroform (HCCl_{3}). This is not quite so poisonous as phosgene, but it has the advantage that it causes nausea and vomiting. The soldier so affected is forced to take off his gas mask and then may fall victim to more toxic gases sent over simultaneously. Chlorpicrin is a liquid and is commonly loaded in a shell or bomb with 20 per cent. of tin chloride, which produces dense white fumes that go through gas masks. It is made from picric acid (trinitrophenol), one of the best known of the high explosives, by treatment with chlorine. The chlorine is obtained, as it is in the household, from common bleaching powder, or "chloride of lime." This is mixed with water to form a cream in a steel still 18 feet high and 8 feet in diameter. A solution of calcium picrate, that is, the lime salt of picric acid, is pumped in and as the reaction begins the mixture heats up and the chlorpicrin distils over with the steam. When the distillate is condensed the chlorpicrin, being the heavier liquid, settles out under the layer of water and may be drawn off to fill the shell. Much of what a student learns in the chemical laboratory he is apt to forget in later life if he does not follow it up. But there are two gases that he always remembers, chlorine and hydrogen sulfide. He is lucky if he has escaped being choked by the former or sickened by the latter. He can imagine what the effect would be if two offensive fumes could be combined without losing their offensive features. Now a combination something like this is the so-called mustard gas, which is not a gas and is not made from mustard. But it is easily gasified, and oil of mustard is about as near as Nature dare come to making such sinful stuff. It was first made by Guthrie, an Englishman, in 1860, and rediscovered by a German chemist, Victor Meyer, in 1886, but he found it so dangerous to work with that he abandoned the investigation. Nobody else cared to take it up, for nobody could see any use for it. So it remained in innocuous desuetude, a mere name in "Beilstein's Dictionary," together with the thousands of other organic compounds that have been invented and never utilized. But on July 12, 1917, the British holding the line at Ypres were besprinkled with this villainous substance. Its success was so great that the Germans henceforth made it their main reliance and soon the Allies followed suit. In one offensive of ten days the Germans are said to have used a million shells containing 2500 tons of mustard gas. The making of so dangerous a compound on a large scale was one of the most difficult tasks set before the chemists of this and other countries, yet it was successfully solved. The raw materials are chlorine, alcohol and sulfur. The alcohol is passed with steam through a vertical iron tube filled with kaolin and heated. This converts the alcohol into a gas known as ethylene (C_{2}H_{4}). Passing a stream of chlorine gas into a tank of melted sulfur produces sulfur monochloride and this treated with the ethylene makes the "mustard." The final reaction was carried on at the Edgewood Arsenal in seven airtight tanks or "reactors," each having a capacity of 30,000 pounds. The ethylene gas being led into the tank and distributed through the liquid sulfur chloride by porous blocks or fine nozzles, the two chemicals combined to form what is officially named "di-chlor-di-ethyl-sulfide" (ClC_{2}H_{4}SC_{2}H_{4}Cl). This, however, is too big a mouthful, so even the chemists were glad to fall in with the commonalty and call it "mustard gas." The effectiveness of "mustard" depends upon its persistence. It is a stable liquid, evaporating slowly and not easily decomposed. It lingers about trenches and dugouts and impregnates soil and cloth for days. Gas masks do not afford complete protection, for even if they are impenetrable they must be taken off some time and the gas lies in wait for that time. In some cases the masks were worn continuously for twelve hours after the attack, but when they were removed the soldiers were overpowered by the poison. A place may seem to be free from it but when the sun heats up the ground the liquid volatilizes and the vapor soaks through the clothing. As the men become warmed up by work their skin is blistered, especially under the armpits. The mustard acts like steam, producing burns that range from a mere reddening to serious ulcerations, always painful and incapacitating, but if treated promptly in the hospital rarely causing death or permanent scars. The gas attacks the eyes, throat, nose and lungs and may lead to bronchitis or pneumonia. It was found necessary at the front to put all the clothing of the soldiers into the sterilizing ovens every night to remove all traces of mustard. General Johnson and his staff in the 77th Division were poisoned in their dugouts because they tried to alleviate the discomfort of their camp cots by bedding taken from a neighboring village that had been shelled the day before. Of the 925 cases requiring medical attention at the Edgewood Arsenal 674 were due to mustard. During the month of August 3-1/2 per cent. of the mustard plant force were sent to the hospital each day on the average. But the record of the Edgewood Arsenal is a striking demonstration of what can be done in the prevention of industrial accidents by the exercise of scientific prudence. In spite of the fact that from three to eleven thousand men were employed at the plant for the year 1918 and turned out some twenty thousand tons of the most poisonous gases known to man, there were only three fatalities and not a single case of blindness. Besides the four toxic gases previously described, chlorine, phosgene, chlorpicrin and mustard, various other compounds have been and many others might be made. A list of those employed in the present war enumerates thirty, among them compounds of bromine, arsenic and cyanogen that may prove more formidable than any so far used. American chemists kept very mum during the war but occasionally one could not refrain from saying: "If the Kaiser knew what I know he would surrender unconditionally by telegraph." No doubt the science of chemical warfare is in its infancy and every foresighted power has concealed weapons of its own in reserve. One deadly compound, whose identity has not yet been disclosed, is known as "Lewisite," from Professor Lewis of Northwestern, who was manufacturing it at the rate of ten tons a day in the "Mouse Trap" stockade near Cleveland. Throughout the history of warfare the art of defense has kept pace with the art of offense and the courage of man has never failed, no matter to what new danger he was exposed. As each new gas employed by the enemy was detected it became the business of our chemists to discover some method of absorbing or neutralizing it. Porous charcoal, best made from such dense wood as coconut shells, was packed in the respirator box together with layers of such chemicals as will catch the gases to be expected. Charcoal absorbs large quantities of any gas. Soda lime and potassium permanganate and nickel salts were among the neutralizers used. The mask is fitted tightly about the face or over the head with rubber. The nostrils are kept closed with a clip so breathing must be done through the mouth and no air can be inhaled except that passing through the absorbent cylinder. Men within five miles of the front were required to wear the masks slung on their chests so they could be put on within six seconds. A well-made mask with a fresh box afforded almost complete immunity for a time and the soldiers learned within a few days to handle their masks adroitly. So the problem of defense against this new offensive was solved satisfactorily, while no such adequate protection against the older weapons of bayonet and shrapnel has yet been devised. Then the problem of the offense was to catch the opponent with his mask off or to make him take it off. Here the lachrymators and the sternutators, the tear gases and the sneeze gases, came into play. Phenylcarbylamine chloride would make the bravest soldier weep on the battlefield with the abandonment of a Greek hero. Di-phenyl-chloro-arsine would set him sneezing. The Germans alternated these with diabolical ingenuity so as to catch us unawares. Some shells gave off voluminous smoke or a vile stench without doing much harm, but by the time our men got used to these and grew careless about their masks a few shells of some extremely poisonous gas were mixed with them. The ideal gas for belligerent purposes would be odorless, colorless and invisible, toxic even when diluted by a million parts of air, not set on fire or exploded by the detonator of the shell, not decomposed by water, not readily absorbed, stable enough to stand storage for six months and capable of being manufactured by the thousands of tons. No one gas will serve all aims. For instance, phosgene being very volatile and quickly dissipated is thrown into trenches that are soon to be taken while mustard gas being very tenacious could not be employed in such a case for the trenches could not be occupied if they were captured. The extensive use of poison gas in warfare by all the belligerents is a vindication of the American protest at the Hague Conference against its prohibition. At the First Conference of 1899 Captain Mahan argued very sensibly that gas shells were no worse than other projectiles and might indeed prove more merciful and that it was illogical to prohibit a weapon merely because of its novelty. The British delegates voted with the Americans in opposition to the clause "the contracting parties agree to abstain from the use of projectiles the sole object of which is the diffusion of asphyxiating or deleterious gases." But both Great Britain and Germany later agreed to the provision. The use of poison gas by Germany without warning was therefore an act of treachery and a violation of her pledge, but the United States has consistently refused to bind herself to any such restriction. The facts reported by General Amos A. Fries, in command of the overseas branch of the American Chemical Warfare Service, give ample support to the American contention at The Hague: Out of 1000 gas casualties there are from 30 to 40 fatalities, while out of 1000 high explosive casualties the number of fatalities run from 200 to 250. While exact figures are as yet not available concerning the men permanently crippled or blinded by high explosives one has only to witness the debarkation of a shipload of troops to be convinced that the number is very large. On the other hand there is, so far as known at present, not a single case of permanent disability or blindness among our troops due to gas and this in face of the fact that the Germans used relatively large quantities of this material. In the light of these facts the prejudice against the use of gas must gradually give way; for the statement made to the effect that its use is contrary to the principles of humanity will apply with far greater force to the use of high explosives. As a matter of fact, for certain purposes toxic gas is an ideal agent. For example, it is difficult to imagine any agent more effective or more humane that may be used to render an opposing battery ineffective or to protect retreating troops. Captain Mahan's argument at The Hague against the proposed prohibition of poison gas is so cogent and well expressed that it has been quoted in treatises on international law ever since. These reasons were, briefly: 1. That no shell emitting such gases is as yet in practical use or has undergone adequate experiment; consequently, a vote taken now would be taken in ignorance of the facts as to whether the results would be of a decisive character or whether injury in excess of that necessary to attain the end of warfare--the immediate disabling of the enemy--would be inflicted. 2. That the reproach of cruelty and perfidy, addressed against these supposed shells, was equally uttered formerly against firearms and torpedoes, both of which are now employed without scruple. Until we know the effects of such asphyxiating shells, there was no saying whether they would be more or less merciful than missiles now permitted. That it was illogical, and not demonstrably humane, to be tender about asphyxiating men with gas, when all are prepared to admit that it was allowable to blow the bottom out of an ironclad at midnight, throwing four or five hundred into the sea, to be choked by water, with scarcely the remotest chance of escape. As Captain Mahan says, the same objection has been raised at the introduction of each new weapon of war, even though it proved to be no more cruel than the old. The modern rifle ball, swift and small and sterilized by heat, does not make so bad a wound as the ancient sword and spear, but we all remember how gunpowder was regarded by the dandies of Hotspur's time: And it was great pity, so it was, This villainous saltpeter should be digg'd Out of the bowels of the harmless earth Which many a good tall fellow had destroy'd So cowardly; and but for these vile guns He would himself have been a soldier. The real reason for the instinctive aversion manifested against any new arm or mode of attack is that it reveals to us the intrinsic horror of war. We naturally revolt against premeditated homicide, but we have become so accustomed to the sword and latterly to the rifle that they do not shock us as they ought when we think of what they are made for. The Constitution of the United States prohibits the infliction of "cruel and unusual punishments." The two adjectives were apparently used almost synonymously, as though any "unusual" punishment were necessarily "cruel," and so indeed it strikes us. But our ingenious lawyers were able to persuade the courts that electrocution, though unknown to the Fathers and undeniably "unusual," was not unconstitutional. Dumdum bullets are rightfully ruled out because they inflict frightful and often incurable wounds, and the aim of humane warfare is to disable the enemy, not permanently to injure him. [Illustration: From "America's Munitions" THE CHLORPICRIN PLANT AT THE EDGEWOOD ARSENAL From these stills, filled with a mixture of bleaching powder, lime, and picric acid, the poisonous gas, chlorpicrin, distills off. This plant produced 31 tons in one day] [Illustration: Courtesy of the Metal and Thermit Corporation, N.Y. REPAIRING THE BROKEN STERN POST OF THE U.S.S. NORTHERN PACIFIC, THE BIGGEST MARINE WELD IN THE WORLD On the right the fractured stern post is shown. On the left it is being mended by means of thermit. Two crucibles each containing 700 pounds of the thermit mixture are seen on the sides of the vessel. From the bottom of these the melted steel flowed down to fill the fracture] In spite of the opposition of the American and British delegates the First Hague Conference adopted the clause, "The contracting powers agree to abstain from the use of projectiles the [sole] object of which is the diffusion of asphyxiating or deleterious gases." The word "sole" (_unique_) which appears in the original French text of The Hague convention is left out of the official English translation. This is a strange omission considering that the French and British defended their use of explosives which diffuse asphyxiating and deleterious gases on the ground that this was not the "sole" purpose of the bombs but merely an accidental effect of the nitric powder used. The Hague Congress of 1907 placed in its rules for war: "It is expressly forbidden to employ poisons or poisonous weapons." But such attempts to rule out new and more effective means of warfare are likely to prove futile in any serious conflict and the restriction gives the advantage to the most unscrupulous side. We Americans, if ever we give our assent to such an agreement, would of course keep it, but our enemy--whoever he may be in the future--will be, as he always has been, utterly without principle and will not hesitate to employ any weapon against us. Besides, as the Germans held, chemical warfare favors the army that is most intelligent, resourceful and disciplined and the nation that stands highest in science and industry. This advantage, let us hope, will be on our side. CHAPTER XIII PRODUCTS OF THE ELECTRIC FURNACE The control of man over the materials of nature has been vastly enhanced by the recent extension of the range of temperature at his command. When Fahrenheit stuck the bulb of his thermometer into a mixture of snow and salt he thought he had reached the nadir of temperature, so he scratched a mark on the tube where the mercury stood and called it zero. But we know that absolute zero, the total absence of heat, is 459 of Fahrenheit's degrees lower than his zero point. The modern scientist can get close to that lowest limit by making use of the cooling by the expansion principle. He first liquefies air under pressure and then releasing the pressure allows it to boil off. A tube of hydrogen immersed in the liquid air as it evaporates is cooled down until it can be liquefied. Then the boiling hydrogen is used to liquefy helium, and as this boils off it lowers the temperature to within three or four degrees of absolute zero. The early metallurgist had no hotter a fire than he could make by blowing charcoal with a bellows. This was barely enough for the smelting of iron. But by the bringing of two carbon rods together, as in the electric arc light, we can get enough heat to volatilize the carbon at the tips, and this means over 7000 degrees Fahrenheit. By putting a pressure of twenty atmospheres onto the arc light we can raise it to perhaps 14,000 degrees, which is 3000 degrees hotter than the sun. This gives the modern man a working range of about 14,500 degrees, so it is no wonder that he can perform miracles. When a builder wants to make an old house over into a new one he takes it apart brick by brick and stone by stone, then he puts them together in such new fashion as he likes. The electric furnace enables the chemist to take his materials apart in the same way. As the temperature rises the chemical and physical forces that hold a body together gradually weaken. First the solid loosens up and becomes a liquid, then this breaks bonds and becomes a gas. Compounds break up into their elements. The elemental molecules break up into their component atoms and finally these begin to throw off corpuscles of negative electricity eighteen hundred times smaller than the smallest atom. These electrons appear to be the building stones of the universe. No indication of any smaller units has been discovered, although we need not assume that in the electron science has delivered, what has been called, its "ultim-atom." The Greeks called the elemental particles of matter "atoms" because they esteemed them "indivisible," but now in the light of the X-ray we can witness the disintegration of the atom into electrons. All the chemical and physical properties of matter, except perhaps weight, seem to depend upon the number and movement of the negative and positive electrons and by their rearrangement one element may be transformed into another. So the electric furnace, where the highest attainable temperature is combined with the divisive and directive force of the current, is a magical machine for accomplishment of the metamorphoses desired by the creative chemist. A hundred years ago Davy, by dipping the poles of his battery into melted soda lye, saw forming on one of them a shining globule like quicksilver. It was the metal sodium, never before seen by man. Nowadays this process of electrolysis (electric loosening) is carried out daily by the ton at Niagara. The reverse process, electro-synthesis (electric combining), is equally simple and even more important. By passing a strong electric current through a mixture of lime and coke the metal calcium disengages itself from the oxygen of the lime and attaches itself to the carbon. Or, to put it briefly, CaO + 3C --> CaC_{2} + CO lime coke calcium carbon carbide monoxide This reaction is of peculiar importance because it bridges the gulf between the organic and inorganic worlds. It was formerly supposed that the substances found in plants and animals, mostly complex compounds of carbon, hydrogen and oxygen, could only be produced by "vital forces." If this were true it meant that chemistry was limited to the mineral kingdom and to the extraction of such carbon compounds as happened to exist ready formed in the vegetable and animal kingdoms. But fortunately this barrier to human achievement proved purely illusory. The organic field, once man had broken into it, proved easier to work in than the inorganic. But it must be confessed that man is dreadfully clumsy about it yet. He takes a thousand horsepower engine and an electric furnace at several thousand degrees to get carbon into combination with hydrogen while the little green leaf in the sunshine does it quietly without getting hot about it. Evidently man is working as wastefully as when he used a thousand slaves to drag a stone to the pyramid or burned down a house to roast a pig. Not until his laboratory is as cool and calm and comfortable as the forest and the field can the chemist call himself completely successful. But in spite of his clumsiness the chemist is actually making things that he wants and cannot get elsewhere. The calcium carbide that he manufactures from inorganic material serves as the raw material for producing all sorts of organic compounds. The electric furnace was first employed on a large scale by the Cowles Electric Smelting and Aluminum Company at Cleveland in 1885. On the dump were found certain lumps of porous gray stone which, dropped into water, gave off a gas that exploded at touch of a match with a splendid bang and flare. This gas was acetylene, and we can represent the reaction thus: CaC_{2} + 2 H_{2}O --> C_{2}H_{2} + CaO_{2}H_{2} calcium carbide _added_ to water _ gives_ acetylene _and_ slaked lime We are all familiar with this reaction now, for it is acetylene that gives the dazzling light of the automobiles and of the automatic signal buoys of the seacoast. When burned with pure oxygen instead of air it gives the hottest of chemical flames, hotter even than the oxy-hydrogen blowpipe. For although a given weight of hydrogen will give off more heat when it burns than carbon will, yet acetylene will give off more heat than either of its elements or both of them when they are separate. This is because acetylene has stored up heat in its formation instead of giving it off as in most reactions, or to put it in chemical language, acetylene is an endothermic compound. It has required energy to bring the H and the C together, therefore it does not require energy to separate them, but, on the contrary, energy is released when they are separated. That is to say, acetylene is explosive not only when mixed with air as coal gas is but by itself. Under a suitable impulse acetylene will break up into its original carbon and hydrogen with great violence. It explodes with twice as much force without air as ordinary coal gas with air. It forms an explosive compound with copper, so it has to be kept out of contact with brass tubes and stopcocks. But compressed in steel cylinders and dissolved in acetone, it is safe and commonly used for welding and melting. It is a marvelous though not an unusual sight on city streets to see a man with blue glasses on cutting down through a steel rail with an oxy-acetylene blowpipe as easily as a carpenter saws off a board. With such a flame he can carve out a pattern in a steel plate in a way that reminds me of the days when I used to make brackets with a scroll saw out of cigar boxes. The torch will travel through a steel plate an inch or two thick at a rate of six to ten inches a minute. [Illustration: Courtesy of the Carborundum Company, Niagara Falls MAKING ALOXITE IN THE ELECTRIC FURNACES BY FUSING COKE AND BAUXITE In the background are the circular furnaces. In the foreground are the fused masses of the product] [Illustration: Courtesy of the Carborundum Co., Niagara Falls A BLOCK OF CARBORUNDUM CRYSTALS] [Illustration: Courtesy of the Carborundum Co., Niagara Falls MAKING CARBORUNDUM IN THE ELECTRIC FURNACE At the end may be seen the attachments for the wires carrying the electric current and on the side the flames from the burning carbon.] The temperatures attainable with various fuels in the compound blowpipe are said to be: Acetylene with oxygen 7878° F. Hydrogen with oxygen 6785° F. Coal gas with oxygen 6575° F. Gasoline with oxygen 5788° F. If we compare the formula of acetylene, C_{2}H_{2} with that of ethylene, C_{2}H_{4}, or with ethane, C_{2}H_{6}, we see that acetylene could take on two or four more atoms. It is evidently what the chemists call an "unsaturated" compound, one that has not reached its limit of hydrogenation. It is therefore a very active and energetic compound, ready to pick up on the slightest instigation hydrogen or oxygen or chlorine or any other elements that happen to be handy. This is why it is so useful as a starting point for synthetic chemistry. To build up from this simple substance, acetylene, the higher compounds of carbon and oxygen it is necessary to call in the aid of that mysterious agency, the catalyst. Acetylene is not always acted upon by water, as we know, for we see it bubbling up through the water when prepared from the carbide. But if to the water be added a little acid and a mercury salt, the acetylene gas will unite with the water forming a new compound, acetaldehyde. We can show the change most simply in this fashion: C_{2}H_{2} + H_{2}O --> C_{2}H_{4}O acetylene _added to_ water _forms_ acetaldehyde Acetaldehyde is not of much importance in itself, but is useful as a transition. If its vapor mixed with hydrogen is passed over finely divided nickel, serving as a catalyst, the two unite and we have alcohol, according to this reaction: C_{2}H_{4}O + H_{2} --> C_{2}H_{6}O acetaldehyde _added to_ hydrogen _forms_ alcohol Alcohol we are all familiar with--some of us too familiar, but the prohibition laws will correct that. The point to be noted is that the alcohol we have made from such unpromising materials as limestone and coal is exactly the same alcohol as is obtained by the fermentation of fruits and grains by the yeast plant as in wine and beer. It is not a substitute or imitation. It is not the wood spirits (methyl alcohol, CH_{4}O), produced by the destructive distillation of wood, equally serviceable as a solvent or fuel, but undrinkable and poisonous. Now, as we all know, cider and wine when exposed to the air gradually turn into vinegar, that is, by the growth of bacteria the alcohol is oxidized to acetic acid. We can, if we like, dispense with the bacteria and speed up the process by employing a catalyst. Acetaldehyde, which is halfway between alcohol and acid, may also be easily oxidized to acetic acid. The relationship is readily seen by this: C{2}H_{6}O --> CC_{2}H_{4}O --> C_{2}H_{4}O_{3} alcohol acetaldehyde acetic acid Acetic acid, familiar to us in a diluted and flavored form as vinegar, is when concentrated of great value in industry, especially as a solvent. I have already referred to its use in combination with cellulose as a "dope" for varnishing airplane canvas or making non-inflammable film for motion pictures. Its combination with lime, calcium acetate, when heated gives acetone, which, as may be seen from its formula (C_{3}H_{6}O) is closely related to the other compounds we have been considering, but it is neither an alcohol nor an acid. It is extensively employed as a solvent. Acetone is not only useful for dissolving solids but it will under pressure dissolve many times its volume of gaseous acetylene. This is a convenient way of transporting and handling acetylene for lighting or welding. If instead of simply mixing the acetone and acetylene in a solution we combine them chemically we can get isoprene, which is the mother substance of ordinary India rubber. From acetone also is made the "war rubber" of the Germans (methyl rubber), which I have mentioned in a previous chapter. The Germans had been getting about half their supply of acetone from American acetate of lime and this was of course shut off. That which was produced in Germany by the distillation of beech wood was not even enough for the high explosives needed at the front. So the Germans resorted to rotting potatoes--or rather let us say, since it sounds better--to the cultivation of _Bacillus macerans_. This particular bacillus converts the starch of the potato into two-thirds alcohol and one-third acetone. But soon potatoes got too scarce to be used up in this fashion, so the Germans turned to calcium carbide as a source of acetone and before the war ended they had a factory capable of manufacturing 2000 tons of methyl rubber a year. This shows the advantage of having several strings to a bow. The reason why acetylene is such an active and acquisitive thing the chemist explains, or rather expresses, by picturing its structure in this shape: H-C[triple bond]C-H Now the carbon atoms are holding each other's hands because they have nothing else to do. There are no other elements around to hitch on to. But the two carbons of acetylene readily loosen up and keeping the connection between them by a single bond reach out in this fashion with their two disengaged arms and grab whatever alien atoms happen to be in the vicinity: | | H-C-C-H | | Carbon atoms belong to the quadrumani like the monkeys, so they are peculiarly fitted to forming chains and rings. This accounts for the variety and complexity of the carbon compounds. So when acetylene gas mixed with other gases is passed over a catalyst, such as a heated mass of iron ore or clay (hydrates or silicates of iron or aluminum), it forms all sorts of curious combinations. In the presence of steam we may get such simple compounds as acetic acid, acetone and the like. But when three acetylene molecules join to form a ring of six carbon atoms we get compounds of the benzene series such as were described in the chapter on the coal-tar colors. If ammonia is mixed with acetylene we may get rings with the nitrogen atom in place of one of the carbons, like the pyridins and quinolins, pungent bases such as are found in opium and tobacco. Or if hydrogen sulfide is mixed with the acetylene we may get thiophenes, which have sulfur in the ring. So, starting with the simple combination of two atoms of carbon with two of hydrogen, we can get directly by this single process some of the most complicated compounds of the organic world, as well as many others not found in nature. In the development of the electric furnace America played a pioneer part. Provost Smith of the University of Pennsylvania, who is the best authority on the history of chemistry in America, claims for Robert Hare, a Philadelphia chemist born in 1781, the honor of constructing the first electrical furnace. With this crude apparatus and with no greater electromotive force than could be attained from a voltaic pile, he converted charcoal into graphite, volatilized phosphorus from its compounds, isolated metallic calcium and synthesized calcium carbide. It is to Hare also that we owe the invention in 1801 of the oxy-hydrogen blowpipe, which nowadays is used with acetylene as well as hydrogen. With this instrument he was able to fuse strontia and volatilize platinum. But the electrical furnace could not be used on a commercial scale until the dynamo replaced the battery as a source of electricity. The industrial development of the electrical furnace centered about the search for a cheap method of preparing aluminum. This is the metallic base of clay and therefore is common enough. But clay, as we know from its use in making porcelain, is very infusible and difficult to decompose. Sixty years ago aluminum was priced at $140 a pound, but one would have had difficulty in buying such a large quantity as a pound at any price. At international expositions a small bar of it might be seen in a case labeled "silver from clay." Mechanics were anxious to get the new metal, for it was light and untarnishable, but the metallurgists could not furnish it to them at a low enough price. In order to extract it from clay a more active metal, sodium, was essential. But sodium also was rare and expensive. In those days a professor of chemistry used to keep a little stick of it in a bottle under kerosene and once a year he whittled off a piece the size of a pea and threw it into water to show the class how it sizzled and gave off hydrogen. The way to get cheaper aluminum was, it seemed, to get cheaper sodium and Hamilton Young Castner set himself at this problem. He was a Brooklyn boy, a student of Chandler's at Columbia. You can see the bronze tablet in his honor at the entrance of Havemeyer Hall. In 1886 he produced metallic sodium by mixing caustic soda with iron and charcoal in an iron pot and heating in a gas furnace. Before this experiment sodium sold at $2 a pound; after it sodium sold at twenty cents a pound. But although Castner had succeeded in his experiment he was defeated in his object. For while he was perfecting the sodium process for making aluminum the electrolytic process for getting aluminum directly was discovered in Oberlin. So the $250,000 plant of the "Aluminium Company Ltd." that Castner had got erected at Birmingham, England, did not make aluminum at all, but produced sodium for other purposes instead. Castner then turned his attention to the electrolytic method of producing sodium by the use of the power of Niagara Falls, electric power. Here in 1894 he succeeded in separating common salt into its component elements, chlorine and sodium, by passing the electric current through brine and collecting the sodium in the mercury floor of the cell. The sodium by the action of water goes into caustic soda. Nowadays sodium and chlorine and their components are made in enormous quantities by the decomposition of salt. The United States Government in 1918 procured nearly 4,000,000 pounds of chlorine for gas warfare. The discovery of the electrical process of making aluminum that displaced the sodium method was due to Charles M. Hall. He was the son of a Congregational minister and as a boy took a fancy to chemistry through happening upon an old text-book of that science in his father's library. He never knew who the author was, for the cover and title page had been torn off. The obstacle in the way of the electrolytic production of aluminum was, as I have said, because its compounds were so hard to melt that the current could not pass through. In 1886, when Hall was twenty-two, he solved the problem in the laboratory of Oberlin College with no other apparatus than a small crucible, a gasoline burner to heat it with and a galvanic battery to supply the electricity. He found that a Greenland mineral, known as cryolite (a double fluoride of sodium and aluminum), was readily fused and would dissolve alumina (aluminum oxide). When an electric current was passed through the melted mass the metal aluminum would collect at one of the poles. In working out the process and defending his claims Hall used up all his own money, his brother's and his uncle's, but he won out in the end and Judge Taft held that his patent had priority over the French claim of Hérault. On his death, a few years ago, Hall left his large fortune to his Alma Mater, Oberlin. Two other young men from Ohio, Alfred and Eugene Cowles, with whom Hall was for a time associated, wore the first to develop the wide possibilities of the electric furnace on a commercial scale. In 1885 they started the Cowles Electric Smelting and Aluminum Company at Lockport, New York, using Niagara power. The various aluminum bronzes made by absorbing the electrolyzed aluminum in copper attracted immediate attention by their beauty and usefulness in electrical work and later the company turned out other products besides aluminum, such as calcium carbide, phosphorus, and carborundum. They got carborundum as early as 1885 but miscalled it "crystallized silicon," so its introduction was left to E.A. Acheson, who was a graduate of Edison's laboratory. In 1891 he packed clay and charcoal into an iron bowl, connected it to a dynamo and stuck into the mixture an electric light carbon connected to the other pole of the dynamo. When he pulled out the rod he found its end encrusted with glittering crystals of an unknown substance. They were blue and black and iridescent, exceedingly hard and very beautiful. He sold them at first by the carat at a rate that would amount to $560 a pound. They were as well worth buying as diamond dust, but those who purchased them must have regretted it, for much finer crystals were soon on sale at ten cents a pound. The mysterious substance turned out to be a compound of carbon and silicon, the simplest possible compound, one atom of each, CSi. Acheson set up a factory at Niagara, where he made it in ten-ton batches. The furnace consisted simply of a brick box fifteen feet long and seven feet wide and deep, with big carbon electrodes at the ends. Between them was packed a mixture of coke to supply the carbon, sand to supply the silicon, sawdust to make the mass porous and salt to make it fusible. [Illustration: The first American electric furnace, constructed by Robert Hare of Philadelphia. From "Chemistry in America," by Edgar Fahs Smith] The substance thus produced at Niagara Falls is known as "carborundum" south of the American-Canadian boundary and as "crystolon" north of this line, as "carbolon" by another firm, and as "silicon carbide" by chemists the world over. Since it is next to the diamond in hardness it takes off metal faster than emery (aluminum oxide), using less power and wasting less heat in futile fireworks. It is used for grindstones of all sizes, including those the dentist uses on your teeth. It has revolutionized shop-practice, for articles can be ground into shape better and quicker than they can be cut. What is more, the artificial abrasives do not injure the lungs of the operatives like sandstone. The output of artificial abrasives in the United States and Canada for 1917 was: Tons Value Silicon carbide 8,323 $1,074,152 Aluminum oxide 48,463 6,969,387 A new use for carborundum was found during the war when Uncle Sam assumed the rôle of Jove as "cloud-compeller." Acting on carborundum with chlorine--also, you remember, a product of electrical dissolution--the chlorine displaces the carbon, forming silicon tetra-chloride (SiCl_{4}), a colorless liquid resembling chloroform. When this comes in contact with moist air it gives off thick, white fumes, for water decomposes it, giving a white powder (silicon hydroxide) and hydrochloric acid. If ammonia is present the acid will unite with it, giving further white fumes of the salt, ammonium chloride. So a mixture of two parts of silicon chloride with one part of dry ammonia was used in the war to produce smoke-screens for the concealment of the movements of troops, batteries and vessels or put in shells so the outlook could see where they burst and so get the range. Titanium tetra-chloride, a similar substance, proved 50 per cent. better than silicon, but phosphorus--which also we get from the electric furnace--was the most effective mistifier of all. Before the introduction of the artificial abrasives fine grinding was mostly done by emery, which is an impure form of aluminum oxide found in nature. A purer form is made from the mineral bauxite by driving off its combined water. Bauxite is the ore from which is made the pure aluminum oxide used in the electric furnace for the production of metallic aluminum. Formerly we imported a large part of our bauxite from France, but when the war shut off this source we developed our domestic fields in Arkansas, Alabama and Georgia, and these are now producing half a million tons a year. Bauxite simply fused in the electric furnace makes a better abrasive than the natural emery or corundum, and it is sold for this purpose under the name of "aloxite," "alundum," "exolon," "lionite" or "coralox." When the fused bauxite is worked up with a bonding material into crucibles or muffles and baked in a kiln it forms the alundum refractory ware. Since alundum is porous and not attacked by acids it is used for filtering hot and corrosive liquids that would eat up filter-paper. Carborundum or crystolon is also made up into refractory ware for high temperature work. When the fused mass of the carborundum furnace is broken up there is found surrounding the carborundum core a similar substance though not quite so hard and infusible, known as "carborundum sand" or "siloxicon." This is mixed with fireclay and used for furnace linings. Many new forms of refractories have come into use to meet the demands of the new high temperature work. The essentials are that it should not melt or crumble at high heat and should not expand and contract greatly under changes of temperature (low coefficient of thermal expansion). Whether it is desirable that it should heat through readily or slowly (coefficient of thermal conductivity) depends on whether it is wanted as a crucible or as a furnace lining. Lime (calcium oxide) fuses only at the highest heat of the electric furnace, but it breaks down into dust. Magnesia (magnesium oxide) is better and is most extensively employed. For every ton of steel produced five pounds of magnesite is needed. Formerly we imported 90 per cent. of our supply from Austria, but now we get it from California and Washington. In 1913 the American production of magnesite was only 9600 tons. In 1918 it was 225,000. Zirconia (zirconium oxide) is still more refractory and in spite of its greater cost zirkite is coming into use as a lining for electric furnaces. Silicon is next to oxygen the commonest element in the world. It forms a quarter of the earth's crust, yet it is unfamiliar to most of us. That is because it is always found combined with oxygen in the form of silica as quartz crystal or sand. This used to be considered too refractory to be blown but is found to be easily manipulable at the high temperatures now at the command of the glass-blower. So the chemist rejoices in flasks that he can heat red hot in the Bunsen burner and then plunge into ice water without breaking, and the cook can bake and serve in a dish of "pyrex," which is 80 per cent. silica. At the beginning of the twentieth century minute specimens of silicon were sold as laboratory curiosities at the price of $100 an ounce. Two years later it was turned out by the barrelful at Niagara as an accidental by-product and could not find a market at ten cents a pound. Silicon from the electric furnace appears in the form of hard, glittering metallic crystals. An alloy of iron and silicon, ferro-silicon, made by heating a mixture of iron ore, sand and coke in the electrical furnace, is used as a deoxidizing agent in the manufacture of steel. Since silicon has been robbed with difficulty of its oxygen it takes it on again with great avidity. This has been made use of in the making of hydrogen. A mixture of silicon (or of the ferro-silicon alloy containing 90 per cent. of silicon) with soda and slaked lime is inert, compact and can be transported to any point where hydrogen is needed, say at a battle front. Then the "hydrogenite," as the mixture is named, is ignited by a hot iron ball and goes off like thermit with the production of great heat and the evolution of a vast volume of hydrogen gas. Or the ferro-silicon may be simply burned in an atmosphere of steam in a closed tank after ignition with a pinch of gunpowder. The iron and the silicon revert to their oxides while the hydrogen of the water is set free. The French "silikol" method consists in treating silicon with a 40 per cent. solution of soda. Another source of hydrogen originating with the electric furnace is "hydrolith," which consists of calcium hydride. Metallic calcium is prepared from lime in the electric furnace. Then pieces of the calcium are spread out in an oven heated by electricity and a current of dry hydrogen passed through. The gas is absorbed by the metal, forming the hydride (CaH_{2}). This is packed up in cans and when hydrogen is desired it is simply dropped into water, when it gives off the gas just as calcium carbide gives off acetylene. This last reaction was also used in Germany for filling Zeppelins. For calcium carbide is convenient and portable and acetylene, when it is once started, as by an electric shock, decomposes spontaneously by its own internal heat into hydrogen and carbon. The latter is left as a fine, pure lampblack, suitable for printer's ink. Napoleon, who was always on the lookout for new inventions that could be utilized for military purposes, seized immediately upon the balloon as an observation station. Within a few years after the first ascent had been made in Paris Napoleon took balloons and apparatus for generating hydrogen with him on his "archeological expedition" to Egypt in which he hoped to conquer Asia. But the British fleet in the Mediterranean put a stop to this experiment by intercepting the ship, and military aviation waited until the Great War for its full development. This caused a sudden demand for immense quantities of hydrogen and all manner of means was taken to get it. Water is easily decomposed into hydrogen and oxygen by passing an electric current through it. In various electrolytical processes hydrogen has been a wasted by-product since the balloon demand was slight and it was more bother than it was worth to collect and purify the hydrogen. Another way of getting hydrogen in quantity is by passing steam over red-hot coke. This produces the blue water-gas, which contains about 50 per cent. hydrogen, 40 per cent. carbon monoxide and the rest nitrogen and carbon dioxide. The last is removed by running the mixed gases through lime. Then the nitrogen and carbon monoxide are frozen out in an air-liquefying apparatus and the hydrogen escapes to the storage tank. The liquefied carbon monoxide, allowed to regain its gaseous form, is used in an internal combustion engine to run the plant. There are then many ways of producing hydrogen, but it is so light and bulky that it is difficult to get it where it is wanted. The American Government in the war made use of steel cylinders each holding 161 cubic feet of the gas under a pressure of 2000 pounds per square inch. Even the hydrogen used by the troops in France was shipped from America in this form. For field use the ferro-silicon and soda process was adopted. A portable generator of this type was capable of producing 10,000 cubic feet of the gas per hour. The discovery by a Kansas chemist of natural sources of helium may make it possible to free ballooning of its great danger, for helium is non-inflammable and almost as light as hydrogen. Other uses of hydrogen besides ballooning have already been referred to in other chapters. It is combined with nitrogen to form synthetic ammonia. It is combined with oxygen in the oxy-hydrogen blowpipe to produce heat. It is combined with vegetable and animal oils to convert them into solid fats. There is also the possibility of using it as a fuel in the internal combustion engine in place of gasoline, but for this purpose we must find some way of getting hydrogen portable or producible in a compact form. Aluminum, like silicon, sodium and calcium, has been rescued by violence from its attachment to oxygen and like these metals it reverts with readiness to its former affinity. Dr. Goldschmidt made use of this reaction in his thermit process. Powdered aluminum is mixed with iron oxide (rust). If the mixture is heated at any point a furious struggle takes place throughout the whole mass between the iron and the aluminum as to which metal shall get the oxygen, and the aluminum always comes out ahead. The temperature runs up to some 6000 degrees Fahrenheit within thirty seconds and the freed iron, completely liquefied, runs down into the bottom of the crucible, where it may be drawn off by opening a trap door. The newly formed aluminum oxide (alumina) floats as slag on top. The applications of the thermit process are innumerable. If, for instance, it is desired to mend a broken rail or crank shaft without moving it from its place, the two ends are brought together or fixed at the proper distance apart. A crucible filled with the thermit mixture is set up above the joint and the thermit ignited with a priming of aluminum and barium peroxide to start it off. The barium peroxide having a superabundance of oxygen gives it up readily and the aluminum thus encouraged attacks the iron oxide and robs it of its oxygen. As soon as the iron is melted it is run off through the bottom of the crucible and fills the space between the rail ends, being kept from spreading by a mold of refractory material such as magnesite. The two ends of the rail are therefore joined by a section of the same size, shape, substance and strength as themselves. The same process can be used for mending a fracture or supplying a missing fragment of a steel casting of any size, such as a ship's propeller or a cogwheel. [Illustration: TYPES OF GAS MASK USED BY AMERICA, THE ALLIES, AND GERMANY DURING THE WAR In the top row are the American masks, chronologically, from left to right: U.S. Navy mask (obsolete), U.S. Navy mask (final type), U.S. Army box respirator (used throughout the war), U.S.R.F.K. respirator, U.S.A.T. respirator (an all-rubber mask), U.S.K.T. respirator (a sewed fabric mask), and U.S. "Model 1919," ready for production when the armistice was signed. In the middle row, left to right, are: British veil (the original emergency mask used in April, 1915), British P.H. helmet (the next emergency mask), British box respirator (standard British army type), French M2 mask (original type), French Tissot artillery mask, and French A.R.S. mask (latest type). In the front row: the latest German mask, the Russian mask, Italian mask, British motor corps mask, U.S. rear area emergency respirator, and U.S. Connell mask] [Illustration: PUMPING MELTED WHITE PHOSPHORUS INTO HAND GRENADES FILLED WITH WATER--EDGEWOOD ARSENAL] [Illustration: FILLING SHELL WITH "MUSTARD GAS" Empty shells are being placed on small trucks to be run into the filling chamber. The large truck in the foreground contains loaded shell] For smaller work thermit has two rivals, the oxy-acetylene torch and electric welding. The former has been described and the latter is rather out of the range of this volume, although I may mention that in the latter part of 1918 there was launched from a British shipyard the first rivotless steel vessel. In this the steel plates forming the shell, bulkheads and floors are welded instead of being fastened together by rivets. There are three methods of doing this depending upon the thickness of the plates and the sort of strain they are subject to. The plates may be overlapped and tacked together at intervals by pressing the two electrodes on opposite sides of the same point until the spot is sufficiently heated to fuse together the plates here. Or roller electrodes may be drawn slowly along the line of the desired weld, fusing the plates together continuously as they go. Or, thirdly, the plates may be butt-welded by being pushed together edge to edge without overlapping and the electric current being passed from one plate to the other heats up the joint where the conductivity is interrupted. It will be observed that the thermit process is essentially like the ordinary blast furnace process of smelting iron and other metals except that aluminum is used instead of carbon to take the oxygen away from the metal in the ore. This has an advantage in case carbon-free metals are desired and the process is used for producing manganese, tungsten, titanium, molybdenum, vanadium and their allows with iron and copper. During the war thermit found a new and terrible employment, as it was used by the airmen for setting buildings on fire and exploding ammunition dumps. The German incendiary bombs consisted of a perforated steel nose-piece, a tail to keep it falling straight and a cylindrical body which contained a tube of thermit packed around with mineral wax containing potassium perchlorate. The fuse was ignited as the missile was released and the thermit, as it heated up, melted the wax and allowed it to flow out together with the liquid iron through the holes in the nose-piece. The American incendiary bombs were of a still more malignant type. They weighed about forty pounds apiece and were charged with oil emulsion, thermit and metallic sodium. Sodium decomposes water so that if any attempt were made to put out with a hose a fire started by one of these bombs the stream of water would be instantaneously changed into a jet of blazing hydrogen. Besides its use in combining and separating different elements the electric furnace is able to change a single element into its various forms. Carbon, for instance, is found in three very distinct forms: in hard, transparent and colorless crystals as the diamond, in black, opaque, metallic scales as graphite, and in shapeless masses and powder as charcoal, coke, lampblack, and the like. In the intense heat of the electric arc these forms are convertible one into the other according to the conditions. Since the third form is the cheapest the object is to change it into one of the other two. Graphite, plumbago or "blacklead," as it is still sometimes called, is not found in many places and more rarely found pure. The supply was not equal to the demand until Acheson worked out the process of making it by packing powdered anthracite between the electrodes of his furnace. In this way graphite can be cheaply produced in any desired quantity and quality. Since graphite is infusible and incombustible except at exceedingly high temperatures, it is extensively used for crucibles and electrodes. These electrodes are made in all sizes for the various forms of electric lamps and furnaces from rods one-sixteenth of an inch in diameter to bars a foot thick and six feet long. It is graphite mixed with fine clay to give it the desired degree of hardness that forms the filling of our "lead" pencils. Finely ground and flocculent graphite treated with tannin may be held in suspension in liquids and even pass through filter-paper. The mixture with water is sold under the name of "aquadag," with oil as "oildag" and with grease as "gredag," for lubrication. The smooth, slippery scales of graphite in suspension slide over each other easily and keep the bearings from rubbing against each other. The other and more difficult metamorphosis of carbon, the transformation of charcoal into diamond, was successfully accomplished by Moissan in 1894. Henri Moissan was a toxicologist, that is to say, a Professor of Poisoning, in the Paris School of Pharmacy, who took to experimenting with the electric furnace in his leisure hours and did more to demonstrate its possibilities than any other man. With it he isolated fluorine, most active of the elements, and he prepared for the first time in their purity many of the rare metals that have since found industrial employment. He also made the carbides of the various metals, including the now common calcium carbide. Among the problems that he undertook and solved was the manufacture of artificial diamonds. He first made pure charcoal by burning sugar. This was packed with iron in the hollow of a block of lime into which extended from opposite sides the carbon rods connected to the dynamo. When the iron had melted and dissolved all the carbon it could, Moissan dumped it into water or better into melted lead or into a hole in a copper block, for this cooled it most rapidly. After a crust was formed it was left to solidify slowly. The sudden cooling of the iron on the outside subjected the carbon, which was held in solution, to intense pressure and when the bit of iron was dissolved in acid some of the carbon was found to be crystallized as diamond, although most of it was graphite. To be sure, the diamonds were hardly big enough to be seen with the naked eye, but since Moissan's aim was to make diamonds, not big diamonds, he ceased his efforts at this point. To produce large diamonds the carbon would have to be liquefied in considerable quantity and kept in that state while it slowly crystallized. But that could only be accomplished at a temperature and pressure and duration unattainable as yet. Under ordinary atmospheric pressure carbon passes over from the solid to the gaseous phase without passing through the liquid, just as snow on a cold, clear day will evaporate without melting. Probably some one in the future will take up the problem where Moissan dropped it and find out how to make diamonds of any size. But it is not a question that greatly interests either the scientist or the industrialist because there is not much to be learned from it and not much to be made out of it. If the inventor of a process for making cheap diamonds could keep his electric furnace secretly in his cellar and market his diamonds cautiously he might get rich out of it, but he would not dare to turn out very large stones or too many of them, for if a suspicion got around that he was making them the price would fall to almost nothing even if he did sell another one. For the high price of the diamond is purely fictitious. It is in the first place kept up by limiting the output of the natural stone by the combination of dealers and, further, the diamond is valued not for its usefulness or beauty but by its real or supposed rarity. Chesterton says: "All is gold that glitters, for the glitter is the gold." This is not so true of gold, for if gold were as cheap as nickel it would be very valuable, since we should gold-plate our machinery, our ships, our bridges and our roofs. But if diamonds were cheap they would be good for nothing except grindstones and drills. An imitation diamond made of heavy glass (paste) cannot be distinguished from the genuine gem except by an expert. It sparkles about as brilliantly, for its refractive index is nearly as high. The reason why it is not priced so highly is because the natural stone has presumably been obtained through the toil and sweat of hundreds of negroes searching in the blue ground of the Transvaal for many months. It is valued exclusively by its cost. To wear a diamond necklace is the same as hanging a certified check for $100,000 by a string around the neck. Real values are enhanced by reduction in the cost of the price of production. Fictitious values are destroyed by it. Aluminum at twenty-five cents a pound is immensely more valuable to the world than when it is a curiosity in the chemist's cabinet and priced at $160 a pound. So the scope of the electric furnace reaches from the costly but comparatively valueless diamond to the cheap but indispensable steel. As F.J. Tone says, if the automobile manufacturers were deprived of Niagara products, the abrasives, aluminum, acetylene for welding and high-speed tool steel, a factory now turning out five hundred cars a day would be reduced to one hundred. I have here been chiefly concerned with electricity as effecting chemical changes in combining or separating elements, but I must not omit to mention its rapidly extending use as a source of heat, as in the production and casting of steel. In 1908 there were only fifty-five tons of steel produced by the electric furnace in the United States, but by 1918 this had risen to 511,364 tons. And besides ordinary steel the electric furnace has given us alloys of iron with the once "rare metals" that have created a new science of metallurgy. CHAPTER XIV METALS, OLD AND NEW The primitive metallurgist could only make use of such metals as he found free in nature, that is, such as had not been attacked and corroded by the ubiquitous oxygen. These were primarily gold or copper, though possibly some original genius may have happened upon a bit of meteoric iron and pounded it out into a sword. But when man found that the red ocher he had hitherto used only as a cosmetic could be made to yield iron by melting it with charcoal he opened a new era in civilization, though doubtless the ocher artists of that day denounced him as a utilitarian and deplored the decadence of the times. Iron is one of the most timid of metals. It has a great disinclination to be alone. It is also one of the most altruistic of the elements. It likes almost every other element better than itself. It has an especial affection for oxygen, and, since this is in both air and water, and these are everywhere, iron is not long without a mate. The result of this union goes by various names in the mineralogical and chemical worlds, but in common language, which is quite good enough for our purpose, it is called iron rust. [Illustration: By courtesy _Mineral Foote-Notes_. From Agricola's "De Re Metallica 1550." Primitive furnace for smelting iron ore.] Not many of us have ever seen iron, the pure metal, soft, ductile and white like silver. As soon as it is exposed to the air it veils itself with a thin film of rust and becomes black and then red. For that reason there is practically no iron in the world except what man has made. It is rarer than gold, than diamonds; we find in the earth no nuggets or crystals of it the size of the fist as we find of these. But occasionally there fall down upon us out of the clear sky great chunks of it weighing tons. These meteorites are the mavericks of the universe. We do not know where they come from or what sun or planet they belonged to. They are our only visitors from space, and if all the other spheres are like these fragments we know we are alone in the universe. For they contain rustless iron, and where iron does not rust man cannot live, nor can any other animal or any plant. Iron rusts for the same reason that a stone rolls down hill, because it gets rid of its energy that way. All things in the universe are constantly trying to get rid of energy except man, who is always trying to get more of it. Or, on second thought, we see that man is the greatest spendthrift of all, for he wants to expend so much more energy than he has that he borrows from the winds, the streams and the coal in the rocks. He robs minerals and plants of the energy which they have stored up to spend for their own purposes, just as he robs the bee of its honey and the silk worm of its cocoon. Man's chief business is in reversing the processes of nature. That is the way he gets his living. And one of his greatest triumphs was when he discovered how to undo iron rust and get the metal out of it. In the four thousand years since he first did this he has accomplished more than in the millions of years before. Without knowing the value of iron rust man could attain only to the culture of the Aztecs and Incas, the ancient Egyptians and Assyrians. The prosperity of modern states is dependent on the amount of iron rust which they possess and utilize. England, United States, Germany, all nations are competing to see which can dig the most iron rust out of the ground and make out of it railroads, bridges, buildings, machinery, battleships and such other tools and toys and then let them relapse into rust again. Civilization can be measured by the amount of iron rusted per capita, or better, by the amount rescued from rust. But we are devoting so much space to the consideration of the material aspects of iron that we are like to neglect its esthetic and ethical uses. The beauty of nature is very largely dependent upon the fact that iron rust and, in fact, all the common compounds of iron are colored. Few elements can assume so many tints. Look at the paint pot cañons of the Yellowstone. Cheap glass bottles turn out brown, green, blue, yellow or black, according to the amount and kind of iron they contain. We build a house of cream-colored brick, varied with speckled brick and adorned with terra cotta ornaments of red, yellow and green, all due to iron. Iron rusts, therefore it must be painted; but what is there better to paint it with than iron rust itself? It is cheap and durable, for it cannot rust any more than a dead man can die. And what is also of importance, it is a good, strong, clean looking, endurable color. Whenever we take a trip on the railroad and see the miles of cars, the acres of roofing and wall, the towns full of brick buildings, we rejoice that iron rust is red, not white or some leas satisfying color. We do not know why it is so. Zinc and aluminum are metals very much like iron in chemical properties, but all their salts are colorless. Why is it that the most useful of the metals forms the most beautiful compounds? Some say, Providence; some say, chance; some say nothing. But if it had not been so we would have lost most of the beauty of rocks and trees and human beings. For the leaves and the flowers would all be white, and all the men and women would look like walking corpses. Without color in the flower what would the bees and painters do? If all the grass and trees were white, it would be like winter all the year round. If we had white blood in our veins like some of the insects it would be hard lines for our poets. And what would become of our morality if we could not blush? "As for me, I thrill to see The bloom a velvet cheek discloses! Made of dust! I well believe it, So are lilies, so are roses." An etiolated earth would be hardly worth living in. The chlorophyll of the leaves and the hemoglobin of the blood are similar in constitution. Chlorophyll contains magnesium in place of iron but iron is necessary to its formation. We all know how pale a plant gets if its soil is short of iron. It is the iron in the leaves that enables the plants to store up the energy of the sunshine for their own use and ours. It is the iron in our blood that enables us to get the iron out of iron rust and make it into machines to supplement our feeble hands. Iron is for us internally the carrier of energy, just as in the form of a trolley wire or of a third rail it conveys power to the electric car. Withdraw the iron from the blood as indicated by the pallor of the cheeks, and we become weak, faint and finally die. If the amount of iron in the blood gets too small the disease germs that are always attacking us are no longer destroyed, but multiply without check and conquer us. When the iron ceases to work efficiently we are killed by the poison we ourselves generate. Counting the number of iron-bearing corpuscles in the blood is now a common method of determining disease. It might also be useful in moral diagnosis. A microscopical and chemical laboratory attached to the courtroom would give information of more value than some of the evidence now obtained. For the anemic and the florid vices need very different treatment. An excess or a deficiency of iron in the body is liable to result in criminality. A chemical system of morals might be developed on this basis. Among the ferruginous sins would be placed murder, violence and licentiousness. Among the non-ferruginous, cowardice, sloth and lying. The former would be mostly sins of commission, the latter, sins of omission. The virtues could, of course, be similarly classified; the ferruginous virtues would include courage, self-reliance and hopefulness; the non-ferruginous, peaceableness, meekness and chastity. According to this ethical criterion the moral man would be defined as one whose conduct is better than we should expect from the per cent. of iron in his blood. The reason why iron is able to serve this unique purpose of conveying life-giving air to all parts of the body is because it rusts so readily. Oxidation and de-oxidation proceed so quietly that the tenderest cells are fed without injury. The blood changes from red to blue and _vice versa_ with greater ease and rapidity than in the corresponding alternations of social status in a democracy. It is because iron is so rustable that it is so useful. The factories with big scrap-heaps of rusting machinery are making the most money. The pyramids are the most enduring structures raised by the hand of man, but they have not sheltered so many people in their forty centuries as our skyscrapers that are already rusting. We have to carry on this eternal conflict against rust because oxygen is the most ubiquitous of the elements and iron can only escape its ardent embraces by hiding away in the center of the earth. The united elements, known to the chemist as iron oxide and to the outside world as rust, are among the commonest of compounds and their colors, yellow and red like the Spanish flag, are displayed on every mountainside. From the time of Tubal Cain man has ceaselessly labored to divorce these elements and, having once separated them, to keep them apart so that the iron may be retained in his service. But here, as usual, man is fighting against nature and his gains, as always, are only temporary. Sooner or later his vigilance is circumvented and the metal that he has extricated by the fiery furnace returns to its natural affinity. The flint arrowheads, the bronze spearpoints, the gold ornaments, the wooden idols of prehistoric man are still to be seen in our museums, but his earliest steel swords have long since crumbled into dust. Every year the blast furnaces of the world release 72,000,000 tons of iron from its oxides and every year a large part, said to be a quarter of that amount, reverts to its primeval forms. If so, then man after five thousand years of metallurgical industry has barely got three years ahead of nature, and should he cease his efforts for a generation there would be little left to show that man had ever learned to extract iron from its ores. The old question, "What becomes of all the pins?" may be as well asked of rails, pipes and threshing machines. The end of all iron is the same. However many may be its metamorphoses while in the service of man it relapses at last into its original state of oxidation. To save a pound of iron from corrosion is then as much a benefit to the world as to produce another pound from the ore. In fact it is of much greater benefit, for it takes four pounds of coal to produce one pound of steel, so whenever a piece of iron is allowed to oxidize it means that four times as much coal must be oxidized in order to replace it. And the beds of coal will be exhausted before the beds of iron ore. If we are ever to get ahead, if we are to gain any respite from this enormous waste of labor and natural resources, we must find ways of preventing the iron which we have obtained and fashioned into useful tools from being lost through oxidation. Now there is only one way of keeping iron and oxygen from uniting and that is to keep them apart. A very thin dividing wall will serve for the purpose, for instance, a film of oil. But ordinary oil will rub off, so it is better to cover the surface with an oil-like linseed which oxidizes to a hard elastic and adhesive coating. If with linseed oil we mix iron oxide or some other pigment we have a paint that will protect iron perfectly so long as it is unbroken. But let the paint wear off or crack so that air can get at the iron, then rust will form and spread underneath the paint on all sides. The same is true of the porcelain-like enamel with which our kitchen iron ware is nowadays coated. So long as the enamel holds it is all right but once it is broken through at any point it begins to scale off and gets into our food. Obviously it would be better for some purposes if we could coat our iron with another and less easily oxidized metal than with such dissimilar substances as paint or porcelain. Now the nearest relative to iron is nickel, and a layer of this of any desired thickness may be easily deposited by electricity upon any surface however irregular. Nickel takes a bright polish and keeps it well, so nickel plating has become the favorite method of protection for small objects where the expense is not prohibitive. Copper plating is used for fine wires. A sheet of iron dipped in melted tin comes out coated with a thin adhesive layer of the latter metal. Such tinned plate commonly known as "tin" has become the favorite material for pans and cans. But if the tin is scratched the iron beneath rusts more rapidly than if the tin were not there, for an electrolytic action is set up and the iron, being the negative element of the couple, suffers at the expense of the tin. With zinc it is quite the opposite. Zinc is negative toward iron, so when the two are in contact and exposed to the weather the zinc is oxidized first. A zinc plating affords the protection of a Swiss Guard, it holds out as long as possible and when broken it perishes to the last atom before it lets the oxygen get at the iron. The zinc may be applied in four different ways. (1) It may be deposited by electrolysis as in nickel plating, but the zinc coating is more apt to be porous. (2) The sheets or articles may be dipped in a bath of melted zinc. This gives us the familiar "galvanized iron," the most useful and when well done the most effective of rust preventives. Besides these older methods of applying zinc there are now two new ones. (3) One is the Schoop process by which a wire of zinc or other metal is fed into an oxy-hydrogen air blast of such heat and power that it is projected as a spray of minute drops with the speed of bullets and any object subjected to the bombardment of this metallic mist receives a coating as thick as desired. The zinc spray is so fine and cool that it may be received on cloth, lace, or the bare hand. The Schoop metallizing process has recently been improved by the use of the electric current instead of the blowpipe for melting the metal. Two zinc wires connected with any electric system, preferably the direct, are fed into the "pistol." Where the wires meet an electric arc is set up and the melted zinc is sprayed out by a jet of compressed air. (4) In the Sherardizing process the articles are put into a tight drum with zinc dust and heated to 800° F. The zinc at this temperature attacks the iron and forms a series of alloys ranging from pure zinc on the top to pure iron at the bottom of the coating. Even if this cracks in part the iron is more or less protected from corrosion so long as any zinc remains. Aluminum is used similarly in the calorizing process for coating iron, copper or brass. First a surface alloy is formed by heating the metal with aluminum powder. Then the temperature is raised to a high degree so as to cause the aluminum on the surface to diffuse into the metal and afterwards it is again baked in contact with aluminum dust which puts upon it a protective plating of the pure aluminum which does not oxidize. [Illustration: PHOTOMICROGRAPHS SHOWING THE STRUCTURE OF STEEL MADE BY PROFESSOR E.G. MARTIN OF PURDUE UNIVERSITY 1. Cold-worked steel showing ferrite and sorbite (enlarged 500 times) 2. Steel showing pearlite crystals (enlarged 500 times) 3. Structure characteristic of air-cooled steel (enlarged 50 times) 4. The triangular structure characteristic of cast steel showing ferrite and pearlite (enlarged 50 times)] [Illustration: Courtesy of E.G. Mahin THE MICROSCOPIC STRUCTURE OF METALS 1. Malleabilized casting; temper carbon in ferrite (enlarged 50 times) 2. Type metal; lead-antimony alloy in matrix of lead (enlarged 100 times) 3. Gray cast iron; carbon as graphite (enlarged 500 times) 4. Steel composed of cementite (white) and pearlite (black) (enlarged 50 times)] Another way of protecting iron ware from rusting is to rust it. This is a sort of prophylactic method like that adopted by modern medicine where inoculation with a mild culture prevents a serious attack of the disease. The action of air and water on iron forms a series of compounds and mixtures of them. Those that contain least oxygen are hard, black and magnetic like iron itself. Those that have most oxygen are red and yellow powders. By putting on a tight coating of the black oxide we can prevent or hinder the oxidation from going on into the pulverulent stage. This is done in several ways. In the Bower-Barff process the articles to be treated are put into a closed retort and a current of superheated steam passed through for twenty minutes followed by a current of producer gas (carbon monoxide), to reduce any higher oxides that may have been formed. In the Gesner process a current of gasoline vapor is used as the reducing agent. The blueing of watch hands, buckles and the like may be done by dipping them into an oxidizing bath such as melted saltpeter. But in order to afford complete protection the layer of black oxide must be thickened by repeating the process which adds to the time and expense. This causes a slight enlargement and the high temperature often warps the ware so it is not suitable for nicely adjusted parts of machinery and of course tools would lose their temper by the heat. A new method of rust proofing which is free from these disadvantages is the phosphate process invented by Thomas Watts Coslett, an English chemist, in 1907, and developed in America by the Parker Company of Detroit. This consists simply in dipping the sheet iron or articles into a tank filled with a dilute solution of iron phosphate heated nearly to the boiling point by steam pipes. Bubbles of hydrogen stream off rapidly at first, then slower, and at the end of half an hour or longer the action ceases, and the process is complete. What has happened is that the iron has been converted into a basic iron phosphate to a depth depending upon the density of articles processed. Any one who has studied elementary qualitative analysis will remember that when he added ammonia to his "unknown" solution, iron and phosphoric acid, if present, were precipitated together, or in other words, iron phosphate is insoluble except in acids. Therefore a superficial film of such phosphate will protect the iron underneath except from acids. This film is not a coating added on the outside like paint and enamel or tin and nickel plate. It is therefore not apt to scale off and it does not increase the size of the article. No high heat is required as in the Sherardizing and Bower-Barff processes, so steel tools can be treated without losing their temper or edge. The deposit consisting of ferrous and ferric phosphates mixed with black iron oxide may be varied in composition, texture and color. It is ordinarily a dull gray and oiling gives a soft mat black more in accordance with modern taste than the shiny nickel plating that delighted our fathers. Even the military nowadays show more quiet taste than formerly and have abandoned their glittering accoutrements. The phosphate bath is not expensive and can be used continuously for months by adding more of the concentrated solution to keep up the strength and removing the sludge that is precipitated. Besides the iron the solution contains the phosphates of other metals such as calcium or strontium, manganese, molybdenum, or tungsten, according to the particular purpose. Since the phosphating solution does not act on nickel it may be used on articles that have been partly nickel-plated so there may be produced, for instance, a bright raised design against a dull black background. Then, too, the surface left by the Parker process is finely etched so it affords a good attachment for paint or enamel if further protection is needed. Even if the enamel does crack, the iron beneath is not so apt to rust and scale off the coating. These, then, are some of the methods which are now being used to combat our eternal enemy, the rust that doth corrupt. All of them are useful in their several ways. No one of them is best for all purposes. The claim of "rust-proof" is no more to be taken seriously than "fire-proof." We should rather, if we were finical, have to speak of "rust-resisting" coatings as we do of "slow-burning" buildings. Nature is insidious and unceasing in her efforts to bring to ruin the achievements of mankind and we need all the weapons we can find to frustrate her destructive determination. But it is not enough for us to make iron superficially resistant to rust from the atmosphere. We should like also to make it so that it would withstand corrosion by acids, then it could be used in place of the large and expensive platinum or porcelain evaporating pans and similar utensils employed in chemical works. This requirement also has been met in the non-corrosive forms of iron, which have come into use within the last five years. One of these, "tantiron," invented by a British metallurgist, Robert N. Lennox, in 1912, contains 15 per cent. of silicon. Similar products are known as "duriron" and "Buflokast" in America, "metilure" in France, "ileanite" in Italy and "neutraleisen" in Germany. It is a silvery-white close-grained iron, very hard and rather brittle, somewhat like cast iron but with silicon as the main additional ingredient in place of carbon. It is difficult to cut or drill but may be ground into shape by the new abrasives. It is rustproof and is not attacked by sulfuric, nitric or acetic acid, hot or cold, diluted or concentrated. It does not resist so well hydrochloric acid or sulfur dioxide or alkalies. The value of iron lies in its versatility. It is a dozen metals in one. It can be made hard or soft, brittle or malleable, tough or weak, resistant or flexible, elastic or pliant, magnetic or non-magnetic, more or less conductive to electricity, by slight changes of composition or mere differences of treatment. No wonder that the medieval mind ascribed these mysterious transformations to witchcraft. But the modern micrometallurgist, by etching the surface of steel and photographing it, shows it up as composite as a block of granite. He is then able to pick out its component minerals, ferrite, austenite, martensite, pearlite, graphite, cementite, and to show how their abundance, shape and arrangement contribute to the strength or weakness of the specimen. The last of these constituents, cementite, is a definite chemical compound, an iron carbide, Fe_{3}C, containing 6.6 per cent. of carbon, so hard as to scratch glass, very brittle, and imparting these properties to hardened steel and cast iron. With this knowledge at his disposal the iron-maker can work with his eyes open and so regulate his melt as to cause these various constituents to crystallize out as he wants them to. Besides, he is no longer confined to the alloys of iron and carbon. He has ransacked the chemical dictionary to find new elements to add to his alloys, and some of these rarities have proved to possess great practical value. Vanadium, for instance, used to be put into a fine print paragraph in the back of the chemistry book, where the class did not get to it until the term closed. Yet if it had not been for vanadium steel we should have no Ford cars. Tungsten, too, was relegated to the rear, and if the student remembered it at all it was because it bothered him to understand why its symbol should be W instead of T. But the student of today studies his lesson in the light of a tungsten wire and relieves his mind by listening to a phonograph record played with a "tungs-tone" stylus. When I was assistant in chemistry an "analysis" of steel consisted merely in the determination of its percentage of carbon, and I used to take Saturday for it so I could have time enough to complete the combustion. Now the chemists of a steel works' laboratory may have to determine also the tungsten, chromium, vanadium, titanium, nickel, cobalt, phosphorus, molybdenum, manganese, silicon and sulfur, any or all of them, and be spry about it, because if they do not get the report out within fifteen minutes while the steel is melting in the electrical furnace the whole batch of 75 tons may go wrong. I'm glad I quit the laboratory before they got to speeding up chemists so. The quality of the steel depends upon the presence and the relative proportions of these ingredients, and a variation of a tenth of 1 per cent. in certain of them will make a different metal out of it. For instance, the steel becomes stronger and tougher as the proportion of nicked is increased up to about 15 per cent. Raising the percentage to 25 we get an alloy that does not rust or corrode and is non-magnetic, although both its component metals, iron and nickel, are by themselves attracted by the magnet. With 36 per cent. nickel and 5 per cent. manganese we get the alloy known as "invar," because it expands and contracts very little with changes of temperature. A bar of the best form of invar will expand less than one-millionth part of its length for a rise of one degree Centigrade at ordinary atmospheric temperature. For this reason it is used in watches and measuring instruments. The alloy of iron with 46 per cent. nickel is called "platinite" because its rate of expansion and contraction is the same as platinum and glass, and so it can be used to replace the platinum wire passing through the glass of an electric light bulb. A manganese steel of 11 to 14 per cent. is too hard to be machined. It has to be cast or ground into shape and is used for burglar-proof safes and armor plate. Chrome steel is also hard and tough and finds use in files, ball bearings and projectiles. Titanium, which the iron-maker used to regard as his implacable enemy, has been drafted into service as a deoxidizer, increasing the strength and elasticity of the steel. It is reported from France that the addition of three-tenths of 1 per cent. of zirconium to nickel steel has made it more resistant to the German perforating bullets than any steel hitherto known. The new "stainless" cutlery contains 12 to 14 per cent. of chromium. With the introduction of harder steels came the need of tougher tools to work them. Now the virtue of a good tool steel is the same as of a good man. It must be able to get hot without losing its temper. Steel of the old-fashioned sort, as everybody knows, gets its temper by being heated to redness and suddenly cooled by quenching or plunging it into water or oil. But when the point gets heated up again, as it does by friction in a lathe, it softens and loses its cutting edge. So the necessity of keeping the tool cool limited the speed of the machine. But about 1868 a Sheffield metallurgist, Robert F. Mushet, found that a piece of steel he was working with did not require quenching to harden it. He had it analyzed to discover the meaning of this peculiarity and learned that it contained tungsten, a rare metal unrecognized in the metallurgy of that day. Further investigation showed that steel to which tungsten and manganese or chromium had been added was tougher and retained its temper at high temperature better than ordinary carbon steel. Tools made from it could be worked up to a white heat without losing their cutting power. The new tools of this type invented by "Efficiency" Taylor at the Bethlehem Steel Works in the nineties have revolutionized shop practice the world over. A tool of the old sort could not cut at a rate faster than thirty feet a minute without overheating, but the new tungsten tools will plow through steel ten times as fast and can cut away a ton of the material in an hour. By means of these high-speed tools the United States was able to turn out five times the munitions that it could otherwise have done in the same time. On the other hand, if Germany alone had possessed the secret of the modern steels no power could have withstood her. A slight superiority in metallurgy has been the deciding factor in many a battle. Those of my readers who have had the advantages of Sunday school training will recall the case described in I Samuel 13:19-22. By means of these new metals armor plate has been made invulnerable--except to projectiles pointed with similar material. Flying has been made possible through engines weighing no more than two pounds per horse power. The cylinders of combustion engines and the casing of cannon have been made to withstand the unprecedented pressure and corrosive action of the fiery gases evolved within. Castings are made so hard that they cannot be cut--save with tools of the same sort. In the high-speed tools now used 20 or 30 per cent, of the iron is displaced by other ingredients; for example, tungsten from 14 to 25 per cent., chromium from 2 to 7 per cent., vanadium from 1/2 to 1-1/2 per cent., carbon from 6 to 8 per cent., with perhaps cobalt up to 4 per cent. Molybdenum or uranium may replace part of the tungsten. Some of the newer alloys for high-speed tools contain no iron at all. That which bears the poetic name of star-stone, stellite, is composed of chromium, cobalt and tungsten in varying proportions. Stellite keeps a hard cutting edge and gets tougher as it gets hotter. It is very hard and as good for jewelry as platinum except that it is not so expensive. Cooperite, its rival, is an alloy of nickel and zirconium, stronger, lighter and cheaper than stellite. Before the war nearly half of the world's supply of tungsten ore (wolframite) came from Burma. But although Burma had belonged to the British for a hundred years they had not developed its mineral resources and the tungsten trade was monopolized by the Germans. All the ore was shipped to Germany and the British Admiralty was content to buy from the Germans what tungsten was needed for armor plate and heavy guns. When the war broke out the British had the ore supply, but were unable at first to work it because they were not familiar with the processes. Germany, being short of tungsten, had to sneak over a little from Baltimore in the submarine _Deutschland_. In the United States before the war tungsten ore was selling at $6.50 a unit, but by the beginning of 1916 it had jumped to $85 a unit. A unit is 1 per cent. of tungsten trioxide to the ton, that is, twenty pounds. Boulder County, Colorado, and San Bernardino, California, then had mining booms, reminding one of older times. Between May and December, 1918, there was manufactured in the United States more than 45,500,000 pounds of tungsten steel containing some 8,000,000 pounds of tungsten. If tungsten ores were more abundant and the metal more easily manipulated, it would displace steel for many purposes. It is harder than steel or even quartz. It never rusts and is insoluble in acids. Its expansion by heat is one-third that of iron. It is more than twice as heavy as iron and its melting point is twice as high. Its electrical resistance is half that of iron and its tensile strength is a third greater than the strongest steel. It can be worked into wire .0002 of an inch in diameter, almost too thin to be seen, but as strong as copper wire ten times the size. The tungsten wires in the electric lamps are about .03 of an inch in diameter, and they give three times the light for the same consumption of electricity as the old carbon filament. The American manufacturers of the tungsten bulb have very appropriately named their lamp "Mazda" after the light god of the Zoroastrians. To get the tungsten into wire form was a problem that long baffled the inventors of the world, for it was too refractory to be melted in mass and too brittle to be drawn. Dr. W.D. Coolidge succeeded in accomplishing the feat in 1912 by reducing the tungstic acid by hydrogen and molding the metallic powder into a bar by pressure. This is raised to a white heat in the electric furnace, taken out and rolled down, and the process repeated some fifty times, until the wire is small enough so it can be drawn at a red heat through diamond dies of successively smaller apertures. The German method of making the lamp filaments is to squirt a mixture of tungsten powder and thorium oxide through a perforated diamond of the desired diameter. The filament so produced is drawn through a chamber heated to 2500° C. at a velocity of eight feet an hour, which crystallizes the tungsten into a continuous thread. The first metallic filament used in the electric light on a commercial scale was made of tantalum, the metal of Tantalus. In the period 1905-1911 over 100,000,000 tantalus lamps were sold, but tungsten displaced them as soon as that metal could be drawn into wire. A recent rival of tungsten both as a filament for lamps and hardener for steel is molybdenum. One pound of this metal will impart more resiliency to steel than three or four pounds of tungsten. The molybdenum steel, because it does not easily crack, is said to be serviceable for armor-piercing shells, gun linings, air-plane struts, automobile axles and propeller shafts. In combination with its rival as a tungsten-molybdenum alloy it is capable of taking the place of the intolerably expensive platinum, for it resists corrosion when used for spark plugs and tooth plugs. European steel men have taken to molybdenum more than Americans. The salts of this metal can be used in dyeing and photography. Calcium, magnesium and aluminum, common enough in their compounds, have only come into use as metals since the invention of the electric furnace. Now the photographer uses magnesium powder for his flashlight when he wants to take a picture of his friends inside the house, and the aviator uses it when he wants to take a picture of his enemies on the open field. The flares prepared by our Government for the war consist of a sheet iron cylinder, four feet long and six inches thick, containing a stick of magnesium attached to a tightly rolled silk parachute twenty feet in diameter when expanded. The whole weighed 32 pounds. On being dropped from the plane by pressing a button, the rush of air set spinning a pinwheel at the bottom which ignited the magnesium stick and detonated a charge of black powder sufficient to throw off the case and release the parachute. The burning flare gave off a light of 320,000 candle power lasting for ten minutes as the parachute slowly descended. This illuminated the ground on the darkest night sufficiently for the airman to aim his bombs or to take photographs. The addition of 5 or 10 per cent. of magnesium to aluminum gives an alloy (magnalium) that is almost as light as aluminum and almost as strong as steel. An alloy of 90 per cent. aluminum and 10 per cent. calcium is lighter and harder than aluminum and more resistant to corrosion. The latest German airplane, the "Junker," was made entirely of duralumin. Even the wings were formed of corrugated sheets of this alloy instead of the usual doped cotton-cloth. Duralumin is composed of about 85 per cent. of aluminum, 5 per cent. of copper, 5 per cent. of zinc and 2 per cent. of tin. When platinum was first discovered it was so cheap that ingots of it were gilded and sold as gold bricks to unwary purchasers. The Russian Government used it as we use nickel, for making small coins. But this is an exception to the rule that the demand creates the supply. Platinum is really a "rare metal," not merely an unfamiliar one. Nowhere except in the Urals is it found in quantity, and since it seems indispensable in chemical and electrical appliances, the price has continually gone up. Russia collapsed into chaos just when the war work made the heaviest demand for platinum, so the governments had to put a stop to its use for jewelry and photography. The "gold brick" scheme would now have to be reversed, for gold is used as a cheaper metal to "adulterate" platinum. All the members of the platinum family, formerly ignored, were pressed into service, palladium, rhodium, osmium, iridium, and these, alloyed with gold or silver, were employed more or less satisfactorily by the dentist, chemist and electrician as substitutes for the platinum of which they had been deprived. One of these alloys, composed of 20 per cent. palladium and 80 per cent. gold, and bearing the telescoped name of "palau" (palladium au-rum) makes very acceptable crucibles for the laboratory and only costs half as much as platinum. "Rhotanium" is a similar alloy recently introduced. The points of our gold pens are tipped with an osmium-iridium alloy. It is a pity that this family of noble metals is so restricted, for they are unsurpassed in tenacity and incorruptibility. They could be of great service to the world in war and peace. As the "Bad Child" says in his "Book of Beasts": I shoot the hippopotamus with bullets made of platinum, Because if I use leaden ones, his hide is sure to flatten 'em. Along in the latter half of the last century chemists had begun to perceive certain regularities and relationships among the various elements, so they conceived the idea that some sort of a pigeon-hole scheme might be devised in which the elements could be filed away in the order of their atomic weights so that one could see just how a certain element, known or unknown, would behave from merely observing its position in the series. Mendeléef, a Russian chemist, devised the most ingenious of such systems called the "periodic law" and gave proof that there was something in his theory by predicting the properties of three metallic elements, then unknown but for which his arrangement showed three empty pigeon-holes. Sixteen years later all three of these predicted elements had been discovered, one by a Frenchman, one by a German and one by a Scandinavian, and named from patriotic impulse, gallium, germanium and scandium. This was a triumph of scientific prescience as striking as the mathematical proof of the existence of the planet Neptune by Leverrier before it had been found by the telescope. But although Mendeléef's law told "the truth," it gradually became evident that it did not tell "the whole truth and nothing but the truth," as the lawyers put it. As usually happens in the history of science the hypothesis was found not to explain things so simply and completely as was at first assumed. The anomalies in the arrangement did not disappear on closer study, but stuck out more conspicuously. Though Mendeléef had pointed out three missing links, he had failed to make provision for a whole group of elements since discovered, the inert gases of the helium-argon group. As we now know, the scheme was built upon the false assumptions that the elements are immutable and that their atomic weights are invariable. The elements that the chemists had most difficulty in sorting out and identifying were the heavy metals found in the "rare earths." There were about twenty of them so mixed up together and so much alike as to baffle all ordinary means of separating them. For a hundred years chemists worked over them and quarreled over them before they discovered that they had a commercial value. It was a problem as remote from practicality as any that could be conceived. The man in the street did not see why chemists should care whether there were two didymiums any more than why theologians should care whether there were two Isaiahs. But all of a sudden, in 1885, the chemical puzzle became a business proposition. The rare earths became household utensils and it made a big difference with our monthly gas bills whether the ceria and the thoria in the burner mantles were absolutely pure or contained traces of some of the other elements that were so difficult to separate. This sudden change of venue from pure to applied science came about through a Viennese chemist, Dr. Carl Auer, later and in consequence known as Baron Auer von Welsbach. He was trying to sort out the rare earths by means of the spectroscopic method, which consists ordinarily in dipping a platinum wire into a solution of the unknown substance and holding it in a colorless gas flame. As it burns off, each element gives a characteristic color to the flame, which is seen as a series of lines when looked at through the spectroscope. But the flash of the flame from the platinum wire was too brief to be studied, so Dr. Auer hit upon the plan of soaking a thread in the liquid and putting this in the gas jet. The cotton of course burned off at once, but the earths held together and when heated gave off a brilliant white light, very much like the calcium or limelight which is produced by heating a stick of quicklime in the oxy-hydrogen flame. But these rare earths do not require any such intense heat as that, for they will glow in an ordinary gas jet. So the Welsbach mantle burner came into use everywhere and rescued the coal gas business from the destruction threatened by the electric light. It was no longer necessary to enrich the gas with oil to make its flame luminous, for a cheaper fuel gas such as is used for a gas stove will give, with a mantle, a fine white light of much higher candle power than the ordinary gas jet. The mantles are knit in narrow cylinders on machines, cut off at suitable lengths, soaked in a solution of the salts of the rare earths and dried. Artificial silk (viscose) has been found better than cotton thread for the mantles, for it is solid, not hollow, more uniform in quality and continuous instead of being broken up into one-inch fibers. There is a great deal of difference in the quality of these mantles, as every one who has used them knows. Some that give a bright glow at first with the gas-cock only half open will soon break up or grow dull and require more gas to get any kind of a light out of them. Others will last long and grow better to the last. Slight impurities in the earths or the gas will speedily spoil the light. The best results are obtained from a mixture of 99 parts thoria and 1 part ceria. It is the ceria that gives the light, yet a little more of it will lower the luminosity. The non-chemical reader is apt to be confused by the strange names and their varied terminations, but he need not be when he learns that the new metals are given names ending in _-um_, such as sodium, cerium, thorium, and that their oxides (compounds with oxygen, the earths) are given the termination _-a_, like soda, ceria, thoria. So when he sees a name ending in _-um_ let him picture to himself a metal, any metal since they mostly look alike, lead or silver, for example. And when he comes across a name ending in _-a_ he may imagine a white powder like lime. Thorium, for instance, is, as its name implies, a metal named after the thunder god Thor, to whom we dedicate one day in each week, Thursday. Cerium gets its name from the Roman goddess of agriculture by way of the asteroid. The chief sources of the material for the Welsbach burners is monazite, a glittering yellow sand composed of phosphate of cerium with some 5 per cent. of thorium. In 1916 the United States imported 2,500,000 pounds of monazite from Brazil and India, most of which used to go to Germany. In 1895 we got over a million and a half pounds from the Carolinas, but the foreign sand is richer and cheaper. The price of the salts of the rare metals fluctuates wildly. In 1895 thorium nitrate sold at $200 a pound; in 1913 it fell to $2.60, and in 1916 it rose to $8. Since the monazite contains more cerium than thorium and the mantles made from it contain more thorium than cerium, there is a superfluity of cerium. The manufacturers give away a pound of cerium salts with every purchase of a hundred pounds of thorium salts. It annoyed Welsbach to see the cerium residues thrown away and accumulating around his mantle factory, so he set out to find some use for it. He reduced the mixed earths to a metallic form and found that it gave off a shower of sparks when scratched. An alloy of cerium with 30 or 35 per cent. of iron proved the best and was put on the market in the form of automatic lighters. A big business was soon built up in Austria on the basis of this obscure chemical element rescued from the dump-heap. The sale of the cerite lighters in France threatened to upset the finances of the republic, which derived large revenue from its monopoly of match-making, so the French Government imposed a tax upon every man who carried one. American tourists who bought these lighters in Germany used to be much annoyed at being held up on the French frontier and compelled to take out a license. During the war the cerium sparklers were much used in the trenches for lighting cigarettes, but--as those who have seen "The Better 'Ole" will know--they sometimes fail to strike fire. Auer-metal or cerium-iron alloy was used in munitions to ignite hand grenades and to blazon the flight of trailer shells. There are many other pyrophoric (light-producing) alloys, including steel, which our ancestors used with flint before matches and percussion caps were invented. There are more than fifty metals known and not half of them have come into common use, so there is still plenty of room for the expansion of the science of metallurgy. If the reader has not forgotten his arithmetic of permutations he can calculate how many different alloys may be formed by varying the combinations and proportions of these fifty. We have seen how quickly elements formerly known only to chemists--and to some of them known only by name--have become indispensable in our daily life. Any one of those still unutilized may be found to have peculiar properties that fit it for filling a long unfelt want in modern civilization. Who, for instance, will find a use for gallium, the metal of France? It was described in 1869 by Mendeléef in advance of its advent and has been known in person since 1875, but has not yet been set to work. It is such a remarkable metal that it must be good for something. If you saw it in a museum case on a cold day you might take it to be a piece of aluminum, but if the curator let you hold it in your hand--which he won't--it would melt and run over the floor like mercury. The melting point is 87° Fahr. It might be used in thermometers for measuring temperatures above the boiling point of mercury were it not for the peculiar fact that gallium wets glass so it sticks to the side of the tube instead of forming a clear convex curve on top like mercury. Then there is columbium, the American metal. It is strange that an element named after Columbia should prove so impractical. Columbium is a metal closely resembling tantalum and tantalum found a use as electric light filaments. A columbium lamp should appeal to our patriotism. The so-called "rare elements" are really abundant enough considering the earth's crust as a whole, though they are so thinly scattered that they are usually overlooked and hard to extract. But whenever one of them is found valuable it is soon found available. A systematic search generally reveals it somewhere in sufficient quantity to be worked. Who, then, will be the first to discover a use for indium, germanium, terbium, thulium, lanthanum, neodymium, scandium, samarium and others as unknown to us as tungsten was to our fathers? As evidence of the statement that it does not matter how rare an element may be it will come into common use if it is found to be commonly useful, we may refer to radium. A good rich specimen of radium ore, pitchblende, may contain as much, as one part in 4,000,000. Madame Curie, the brilliant Polish Parisian, had to work for years before she could prove to the world that such an element existed and for years afterwards before she could get the metal out. Yet now we can all afford a bit of radium to light up our watch dials in the dark. The amount needed for this is infinitesimal. If it were more it would scorch our skins, for radium is an element in eruption. The atom throws off corpuscles at intervals as a Roman candle throws off blazing balls. Some of these particles, the alpha rays, are atoms of another element, helium, charged with positive electricity and are ejected with a velocity of 18,000 miles a second. Some of them, the beta rays, are negative electrons, only about one seven-thousandth the size of the others, but are ejected with almost the speed of light, 186,000 miles a second. If one of the alpha projectiles strikes a slice of zinc sulfide it makes a splash of light big enough to be seen with a microscope, so we can now follow the flight of a single atom. The luminous watch dials consist of a coating of zinc sulfide under continual bombardment by the radium projectiles. Sir William Crookes invented this radium light apparatus and called it a "spinthariscope," which is Greek for "spark-seer." Evidently if radium is so wasteful of its substance it cannot last forever nor could it have forever existed. The elements then ate not necessarily eternal and immutable, as used to be supposed. They have a natural length of life; they are born and die and propagate, at least some of them do. Radium, for instance, is the offspring of ionium, which is the great-great-grandson of uranium, the heaviest of known elements. Putting this chemical genealogy into biblical language we might say: Uranium lived 5,000,000,000 years and begot Uranium X1, which lived 24.6 days and begot Uranium X2, which lived 69 seconds and begot Uranium 2, which lived 2,000,000 years and begot Ionium, which lived 200,000 years and begot Radium, which lived 1850 years and begot Niton, which lived 3.85 days and begot Radium A, which lived 3 minutes and begot Radium B, which lived 26.8 minutes and begot Radium C, which lived 19.5 minutes and begot Radium D, which lived 12 years and begot Radium E, which lived 5 days and begot Polonium, which lived 136 days and begot Lead. The figures I have given are the times when half the parent substance has gone over into the next generation. It will be seen that the chemist is even more liberal in his allowance of longevity than was Moses with the patriarchs. It appears from the above that half of the radium in any given specimen will be transformed in about 2000 years. Half of what is left will disappear in the next 2000 years, half of that in the next 2000 and so on. The reader can figure out for himself when it will all be gone. He will then have the answer to the old Eleatic conundrum of when Achilles will overtake the tortoise. But we may say that after 100,000 years there would not be left any radium worth mentioning, or in other words practically all the radium now in existence is younger than the human race. The lead that is found in uranium and has presumably descended from uranium, behaves like other lead but is lighter. Its atomic weight is only 206, while ordinary lead weighs 207. It appears then that the same chemical element may have different atomic weights according to its ancestry, while on the other hand different chemical elements may have the same atomic weight. This would have seemed shocking heresy to the chemists of the last century, who prided themselves on the immutability of the elements and did not take into consideration their past life or heredity. The study of these radioactive elements has led to a new atomic theory. I suppose most of us in our youth used to imagine the atom as a little round hard ball, but now it is conceived as a sort of solar system with an electropositive nucleus acting as the sun and negative electrons revolving around it like the planets. The number of free positive electrons in the nucleus varies from one in hydrogen to 92 in uranium. This leaves room for 92 possible elements and of these all but six are more or less certainly known and definitely placed in the scheme. The atom of uranium, weighing 238 times the atom of hydrogen, is the heaviest known and therefore the ultimate limit of the elements, though it is possible that elements may be found beyond it just as the planet Neptune was discovered outside the orbit of Uranus. Considering the position of uranium and its numerous progeny as mentioned above, it is quite appropriate that this element should bear the name of the father of all the gods. In these radioactive elements we have come upon sources of energy such as was never dreamed of in our philosophy. The most striking peculiarity of radium is that it is always a little warmer than its surroundings, no matter how warm these may be. Slowly, spontaneously and continuously, it decomposes and we know no way of hastening or of checking it. Whether it is cooled in liquefied air or heated to its melting point the change goes on just the same. An ounce of radium salt will give out enough heat in one hour to melt an ounce of ice and in the next hour will raise this water to the boiling point, and so on again and again without cessation for years, a fire without fuel, a realization of the philosopher's lamp that the alchemists sought in vain. The total energy so emitted is millions of times greater than that produced by any chemical combination such as the union of oxygen and hydrogen to form water. From the heavy white salt there is continually rising a faint fire-mist like the will-o'-the-wisp over a swamp. This gas is known as the emanation or niton, "the shining one." A pound of niton would give off energy at the rate of 23,000 horsepower; fine stuff to run a steamer, one would think, but we must remember that it does not last. By the sixth day the power would have fallen off by half. Besides, no one would dare to serve as engineer, for the radiation will rot away the flesh of a living man who comes near it, causing gnawing ulcers or curing them. It will not only break down the complex and delicate molecules of organic matter but will attack the atom itself, changing, it is believed, one element into another, again the fulfilment of a dream of the alchemists. And its rays, unseen and unfelt by us, are yet strong enough to penetrate an armorplate and photograph what is behind it. But radium is not the most mysterious of the elements but the least so. It is giving out the secret that the other elements have kept. It suggests to us that all the other elements in proportion to their weight have concealed within them similar stores of energy. Astronomers have long dazzled our imaginations by calculating the horsepower of the world, making us feel cheap in talking about our steam engines and dynamos when a minutest fraction of the waste dynamic energy of the solar system would make us all as rich as millionaires. But the heavenly bodies are too big for us to utilize in this practical fashion. And now the chemists have become as exasperating as the astronomers, for they give us a glimpse of incalculable wealth in the meanest substance. For wealth is measured by the available energy of the world, and if a few ounces of anything would drive an engine or manufacture nitrogenous fertilizer from the air all our troubles would be over. Kipling in his sketch, "With the Night Mail," and Wells in his novel, "The World Set Free," stretched their imaginations in trying to tell us what it would mean to have command of this power, but they are a little hazy in their descriptions of the machinery by which it is utilized. The atom is as much beyond our reach as the moon. We cannot rob its vault of the treasure. READING REFERENCES The foregoing pages will not have achieved their aim unless their readers have become sufficiently interested in the developments of industrial chemistry to desire to pursue the subject further in some of its branches. Assuming such interest has been aroused, I am giving below a few references to books and articles which may serve to set the reader upon the right track for additional information. To follow the rapid progress of applied science it is necessary to read continuously such periodicals as the _Journal of Industrial and Engineering Chemistry_ (New York), _Metallurgical and Chemical Engineering_ (New York), _Journal of the Society of Chemical Industry_ (London), _Chemical Abstracts_ (published by the American Chemical Society, Easton, Pa.), and the various journals devoted to special trades. The reader may need to be reminded that the United States Government publishes for free distribution or at low price annual volumes or special reports dealing with science and industry. Among these may be mentioned "Yearbook of the Department of Agriculture"; "Mineral Resources of the United States," published by the United States Geological Survey in two annual volumes, Vol. I on the metals and Vol. II on the non-metals; the "Annual Report of the Smithsonian Institution," containing selected articles on pure and applied science; the daily "Commerce Reports" and special bulletins of Department of Commerce. Write for lists of publications of these departments. The following books on industrial chemistry in general are recommended for reading and reference: "The Chemistry of Commerce" and "Some Chemical Problems of To-Day" by Robert Kennedy Duncan (Harpers, N.Y.), "Modern Chemistry and Its Wonders" by Martin (Van Nostrand), "Chemical Discovery and Invention in the Twentieth Century" by Sir William A. Tilden (Dutton, N.Y.), "Discoveries and Inventions of the Twentieth Century" by Edward Cressy (Dutton), "Industrial Chemistry" by Allen Rogers (Van Nostrand). "Everyman's Chemistry" by Ellwood Hendrick (Harpers, Modern Science Series) is written in a lively style and assumes no previous knowledge of chemistry from the reader. The chapters on cellulose, gums, sugars and oils are particularly interesting. "Chemistry of Familiar Things" by S.S. Sadtler (Lippincott) is both comprehensive and comprehensible. The following are intended for young readers but are not to be despised by their elders who may wish to start in on an easy up-grade: "Chemistry of Common Things" (Allyn & Bacon, Boston) is a popular high school text-book but differing from most text-books in being readable and attractive. Its descriptions of industrial processes are brief but clear. The "Achievements of Chemical Science" by James C. Philip (Macmillan) is a handy little book, easy reading for pupils. "Introduction to the Study of Science" by W.P. Smith and E.G. Jewett (Macmillan) touches upon chemical topics in a simple way. On the history of commerce and the effect of inventions on society the following titles may be suggested: "Outlines of Industrial History" by E. Cressy (Macmillan); "The Origin of Invention," a study of primitive industry, by O.T. Mason (Scribner); "The Romance of Commerce" by Gordon Selbridge (Lane); "Industrial and Commercial Geography" or "Commerce and Industry" by J. Russell Smith (Holt); "Handbook of Commercial Geography" by G.G. Chisholm (Longmans). The newer theories of chemistry and the constitution of the atom are explained in "The Realities of Modern Science" by John Mills (Macmillan), and "The Electron" by R.A. Millikan (University of Chicago Press), but both require a knowledge of mathematics. The little book on "Matter and Energy" by Frederick Soddy (Holt) is better adapted to the general reader. The most recent text-book is the "Introduction to General Chemistry" by H.N. McCoy and E.M. Terry. (Chicago, 1919.) CHAPTER II The reader who may be interested in following up this subject will find references to all the literature in the summary by Helen R. Hosmer, of the Research Laboratory of the General Electric Company, in the _Journal of Industrial and Engineering Chemistry_, New York, for April, 1917. Bucher's paper may be found in the same journal for March, and the issue for September contains a full report of the action of U.S. Government and a comparison of the various processes. Send fifteen cents to the U.S. Department of Commerce (or to the nearest custom house) for Bulletin No. 52, Special Agents Series on "Utilization of Atmospheric Nitrogen" by T.H. Norton. The Smithsonian Institution of Washington has issued a pamphlet on "Sources of Nitrogen Compounds in the United States." In the 1913 report of the Smithsonian Institution there are two fine articles on this subject: "The Manufacture of Nitrates from the Atmosphere" and "The Distribution of Mankind," which discusses Sir William Crookes' prediction of the exhaustion of wheat land. The D. Van Nostrand Co., New York, publishes a monograph on "Fixation of Atmospheric Nitrogen" by J. Knox, also "TNT and Other Nitrotoluenes" by G.C. Smith. The American Cyanamid Company, New York, gives out some attractive literature on their process. "American Munitions 1917-1918," the report of Benedict Crowell, Director of Munitions, to the Secretary of War, gives a fully illustrated account of the manufacture of arms, explosives and toxic gases. Our war experience in the "Oxidation of Ammonia" is told by C.L. Parsons in _Journal of Industrial and Engineering Chemistry_, June, 1919, and various other articles on the government munition work appeared in the same journal in the first half of 1919. "The Muscle Shoals Nitrate Plant" in _Chemical and Metallurgical Engineering_, January, 1919. CHAPTER III The Department of Agriculture or your congressman will send you literature on the production and use of fertilizers. From your state agricultural experiment station you can procure information as to local needs and products. Consult the articles on potash salts and phosphate rock in the latest volume of "Mineral Resources of the United States," Part II Non-Metals (published free by the U.S. Geological Survey). Also consult the latest Yearbook of the Department of Agriculture. For self-instruction, problems and experiments get "Extension Course in Soils," Bulletin No. 355, U.S. Dept. of Agric. A list of all government publications on "Soil and Fertilizers" is sent free by Superintendent of Documents, Washington. The _Journal of Industrial and Engineering Chemistry_ for July, 1917, publishes an article by W.C. Ebaugh on "Potash and a World Emergency," and various articles on American sources of potash appeared in the same _Journal_ October, 1918, and February, 1918. Bulletin 102, Part 2, of the United States National Museum contains an interpretation of the fertilizer situation in 1917 by J.E. Poque. On new potash deposits in Alsace and elsewhere see _Scientific American Supplement_, September 14, 1918. CHAPTER IV Send ten cents to the Department of Commerce, Washington, for "Dyestuffs for American Textile and Other Industries," by Thomas H. Norton, Special Agents' Series, No. 96. A more technical bulletin by the same author is "Artificial Dyestuffs Used in the United States," Special Agents' Series, No. 121, thirty cents. "Dyestuff Situation in U.S.," Special Agents' Series, No. 111, five cents. "Coal-Tar Products," by H.G. Porter, Technical Paper 89, Bureau of Mines, Department of the Interior, five cents. "Wealth in Waste," by Waldemar Kaempfert, _McClure's_, April, 1917. "The Evolution of Artificial Dyestuffs," by Thomas H. Norton, _Scientific American_, July 21, 1917. "Germany's Commercial Preparedness for Peace," by James Armstrong, _Scientific American_, January 29, 1916. "The Conquest of Commerce" and "American Made," by Edwin E. Slosson in _The Independent_ of September 6 and October 11, 1915. The H. Koppers Company, Pittsburgh, give out an illustrated pamphlet on their "By-Product Coke and Gas Ovens." The addresses delivered during the war on "The Aniline Color, Dyestuff and Chemical Conditions," by I.F. Stone, president of the National Aniline and Chemical Company, have been collected in a volume by the author. For "Dyestuffs as Medicinal Agents" by G. Heyl, see _Color Trade Journal_, vol. 4, p. 73, 1919. "The Chemistry of Synthetic Drugs" by Percy May, and "Color in Relation to Chemical Constitution" by E.R. Watson are published in Longmans' "Monographs on Industrial Chemistry." "Enemy Property in the United States" by A. Mitchell Palmer in _Saturday Evening Post_, July 19, 1919, tells of how Germany monopolized chemical industry. "The Carbonization of Coal" by V.B. Lewis (Van Nostrand, 1912). "Research in the Tar Dye Industry" by B.C. Hesse in _Journal of Industrial and Engineering Chemistry_, September, 1916. Kekulé tells how he discovered the constitution of benzene in the _Berichte der Deutschen chemischen Gesellschaft_, V. XXIII, I, p. 1306. I have quoted it with some other instances of dream discoveries in _The Independent_ of Jan. 26, 1918. Even this innocent scientific vision has not escaped the foul touch of the Freudians. Dr. Alfred Robitsek in "Symbolisches Denken in der chemischen Forschung," _Imago_, V. I, p. 83, has deduced from it that Kekulé was morally guilty of the crime of OEdipus as well as minor misdemeanors. CHAPTER V Read up on the methods of extracting perfumes from flowers in any encyclopedia or in Duncan's "Chemistry of Commerce" or Tilden's "Chemical Discovery in the Twentieth Century" or Rogers' "Industrial Chemistry." The pamphlet containing a synopsis of the lectures by the late Alois von Isakovics on "Synthetic Perfumes and Flavors," published by the Synfleur Scientific Laboratories, Monticello, New York, is immensely interesting. Van Dyk & Co., New York, issue a pamphlet on the composition of oil of rose. Gildemeister's "The Volatile Oils" is excellent on the history of the subject. Walter's "Manual for the Essence Industry" (Wiley) gives methods and recipes. Parry's "Chemistry of Essential Oils and Artificial Perfumes," 1918 edition. "Chemistry and Odoriferous Bodies Since 1914" by G. Satie in _Chemie et Industrie_, vol. II, p. 271, 393. "Odor and Chemical Constitution," _Chemical Abstracts_, 1917, p. 3171 and _Journal of Society for Chemical Industry_, v. 36, p. 942. CHAPTER VI The bulletin on "By-Products of the Lumber Industry" by H.K. Benson (published by Department of Commerce, Washington, 10 cents) contains a description of paper-making and wood distillation. There is a good article on cellulose products by H.S. Mork in _Journal of the Franklin Institute_, September, 1917, and in _Paper_, September 26, 1917. The Government Forest Products Laboratory at Madison, Wisconsin, publishes technical papers on distillation of wood, etc. The Forest Service of the U.S. Department of Agriculture is the chief source of information on forestry. The standard authority is Cross and Bevans' "Cellulose." For the acetates see the eighth volume of Worden's "Technology of the Cellulose Esters." CHAPTER VII The speeches made when Hyatt was awarded the Perkin medal by the American Chemical Society for the discovery of celluloid may be found in the _Journal of the Society of Chemical Industry_ for 1914, p. 225. In 1916 Baekeland received the same medal, and the proceedings are reported in the same _Journal_, v. 35, p. 285. A comprehensive technical paper with bibliography on "Synthetic Resins" by L.V. Redman appeared in the _Journal of Industrial and Engineering Chemistry_, January, 1914. The controversy over patent rights may be followed in the same _Journal_, v. 8 (1915), p. 1171, and v. 9 (1916), p. 207. The "Effects of Heat on Celluloid" have been examined by the Bureau of Standards, Washington (Technological Paper No. 98), abstract in _Scientific American Supplement_, June 29, 1918. For casein see Tague's article in Rogers' "Industrial Chemistry" (Van Nostrand). See also Worden's "Nitrocellulose Industry" and "Technology of the Cellulose Esters" (Van Nostrand); Hodgson's "Celluloid" and Cross and Bevan's "Cellulose." For references to recent research and new patent specifications on artificial plastics, resins, rubber, leather, wood, etc., see the current numbers of _Chemical Abstracts_ (Easton, Pa.) and such journals as the _India Rubber Journal, Paper, Textile World, Leather World_ and _Journal of American Leather Chemical Association._ The General Bakelite Company, New York, the Redmanol Products Company, Chicago, the Condensite Company, Bloomfield, N.J., the Arlington Company, New York (handling pyralin), give out advertising literature regarding their respective products. CHAPTER VIII Sir William Tilden's "Chemical Discovery and Invention in the Twentieth Century" (E.P. Dutton & Co.) contains a readable chapter on rubber with references to his own discovery. The "Wonder Book of Rubber," issued by the B.F. Goodrich Rubber Company, Akron, Ohio, gives an interesting account of their industry. Iles: "Leading American Inventors" (Henry Holt & Co.) contains a life of Goodyear, the discoverer of vulcanization. Potts: "Chemistry of the Rubber Industry, 1912." The Rubber Industry: Report of the International Rubber Congress, 1914. Pond: "Review of Pioneer Work in Rubber Synthesis" in _Journal of the American Chemical Society_, 1914. Bang: "Synthetic Rubber" in _Metallurgical and Chemical Engineering_, May 1, 1917. Castellan: "L'Industrie caoutchoucière," doctor's thesis, University of Paris, 1915. The _India Rubber World_, New York, all numbers, especially "What I Saw in the Philippines," by the Editor, 1917. Pearson: "Production of Guayule Rubber," _Commerce Reports_, 1918, and _India Rubber World_, 1919. "Historical Sketch of Chemistry of Rubber" by S.C. Bradford in _Science Progress_, v. II, p. 1. CHAPTER IX "The Cane Sugar Industry" (Bulletin No. 53, Miscellaneous Series, Department of Commerce, 50 cents) gives agricultural and manufacturing costs in Hawaii, Porto Rico, Louisiana and Cuba. "Sugar and Its Value as Food," by Mary Hinman Abel. (Farmer's Bulletin No. 535, Department of Agriculture, free.) "Production of Sugar in the United States and Foreign Countries," by Perry Elliott. (Department of Agriculture, 10 cents.) "Conditions in the Sugar Market January to October, 1917," a pamphlet published by the American Sugar Refining Company, 117 Wall Street, New York, gives an admirable survey of the present situation as seen by the refiners. "Cuban Cane Sugar," by Robert Wiles, 1916 (Indianapolis: Bobbs-Merrill Co., 75 cents), an attractive little book in simple language. "The World's Cane Sugar Industry, Past and Present," by H.C.P. Geering. "The Story of Sugar," by Prof. G.T. Surface of Yale (Appleton, 1910). A very interesting and reliable book. The "Digestibility of Glucose" is discussed in _Journal of Industrial and Engineering Chemistry_, August, 1917. "Utilization of Beet Molasses" in _Metallurgical and Chemical Engineering_, April 5, 1917. CHAPTER X "Maize," by Edward Alber (Bulletin of the Pan-American Union, January, 1915). "Glucose," by Geo. W. Rolfe _(Scientific American Supplement_, May 15 or November 6, 1915, and in Boger's "Industrial Chemistry"). On making ethyl alcohol from wood, see Bulletin No. 110, Special Agents' Series, Department of Commerce (10 cents), and an article by F.W. Kressmann in _Metallurgical and Chemical Engineering_, July 15, 1916. On the manufacture and uses of industrial alcohol the Department of Agriculture has issued for free distribution Farmer's Bulletin 269 and 424, and Department Bulletin 182. On the "Utilization of Corn Cobs," see _Journal of Industrial and Engineering Chemistry_, Nov., 1918. For John Winthrop's experiment, see the same _Journal_, Jan., 1919. CHAPTER XI President Scherer's "Cotton as a World Power" (Stokes, 1916) is a fascinating volume that combines the history, science and politics of the plant and does not ignore the poetry and legend. In the Yearbook of the Department of Agriculture for 1916 will be found an interesting article by H.S. Bailey on "Some American Vegetable Oils" (sold separate for five cents), also "The Peanut: A Great American Food" by same author in the Yearbook of 1917. "The Soy Bean Industry" is discussed in the same volume. See also: Thompson's "Cottonseed Products and Their Competitors in Northern Europe" (Part I, Cake and Meal; Part II, Edible Oils. Department of Commerce, 10 cents each). "Production and Conservation of Fats and Oils in the United States" (Bulletin No. 769, 1919, U.S. Dept. of Agriculture). "Cottonseed Meal for Feeding Cattle" (U.S. Department of Agriculture, Farmer's Bulletin 655, free). "Cottonseed Industry in Foreign Countries," by T.H. Norton, 1915 (Department of Commerce, 10 cents). "Cottonseed Products" in _Journal of the Society of Chemical Industry_, July 16, 1917, and Baskerville's article in the same journal (1915, vol. 7, p. 277). Dunstan's "Oil Seeds and Feeding Cakes," a volume on British problems since the war. Ellis's "The Hydrogenation of Oils" (Van Nostrand, 1914). Copeland's "The Coconut" (Macmillan). Barrett's "The Philippine Coconut Industry" (Bulletin No. 25, Philippine Bureau of Agriculture). "Coconuts, the Consols of the East" by Smith and Pope (London). "All About Coconuts" by Belfort and Hoyer (London). Numerous articles on copra and other oils appear in _U.S. Commerce Reports_ and _Philippine Journal of Science_. "The World Wide Search for Oils" in _The Americas_ (National City Bank, N.Y.). "Modern Margarine Technology" by W. Clayton in _Journal Society of Chemical Industry_, Dec. 5, 1917; also see _Scientific_ _American Supplement_, Sept. 21, 1918. A court decision on the patent rights of hydrogenation is given in _Journal of Industrial and Engineering Chemistry_ for December, 1917. The standard work on the whole subject is Lewkowitsch's "Chemical Technology of Oils, Fats and Waxes" (3 vols., Macmillan, 1915). CHAPTER XII A full account of the development of the American Warfare Service has been published in the _Journal of Industrial and Engineering Chemistry_ in the monthly issues from January to August, 1919, and an article on the British service in the issue of April, 1918. See also Crowell's Report on "America's Munitions," published by War Department. _Scientific American_, March 29, 1919, contains several articles. A. Russell Bond's "Inventions of the Great War" (Century) contains chapters on poison gas and explosives. Lieutenant Colonel S.J.M. Auld, Chief Gas Officer of Sir Julian Byng's army and a member of the British Military Mission to the United States, has published a volume on "Gas and Flame in Modern Warfare" (George H. Doran Co.). CHAPTER XIII See chapter in Cressy's "Discoveries and Inventions of Twentieth Century." "Oxy-Acetylene Welders," Bulletin No. 11, Federal Board of Vocational Education, Washington, June, 1918, gives practical directions for welding. _Reactions_, a quarterly published by Goldschmidt Thermit Company, N.Y., reports latest achievements of aluminothermics. Provost Smith's "Chemistry in America" (Appleton) tells of the experiments of Robert Hare and other pioneers. "Applications of Electrolysis in Chemical Industry" by A.F. Hall (Longmans). For recent work on artificial diamonds see _Scientific American Supplement_, Dec. 8, 1917, and August 24, 1918. On acetylene see "A Storehouse of Sleeping Energy" by J.M. Morehead in _Scientific American_, January 27, 1917. CHAPTER XIV Spring's "Non-Technical Talks on Iron and Steel" (Stokes) is a model of popular science writing, clear, comprehensive and abundantly illustrated. Tilden's "Chemical Discovery in the Twentieth Century" must here again be referred to. The Encyclopedia Britannica is convenient for reference on the various metals mentioned; see the article on "Lighting" for the Welsbach burner. The annual "Mineral Resources of the United States, Part I," contains articles on the newer metals by Frank W. Hess; see "Tungsten" in the volume for 1914, also Bulletin No. 652, U.S. Geological Survey, by same author. _Foote-Notes_, the house organ of the Foote Mineral Company, Philadelphia, gives information on the rare elements. Interesting advertising literature may be obtained from the Titantium Alloy Manufacturing Company, Niagara Falls, N.Y.; Duriron Castings Company, Dayton, O.; Buffalo Foundry and Machine Company, Buffalo, N.Y., manufacturers of "Buflokast" acid-proof apparatus, and similar concerns. The following additional references may be useful: Stellite alloys in _Jour. Ind. & Eng. Chem._, v. 9, p. 974; Rossi's work on titantium in same journal, Feb., 1918; Welsbach mantles in _Journal Franklin Institute_, v. 14, p. 401, 585; pure alloys in _Trans. Amer. Electro-Chemical Society_, v. 32, p. 269; molybdenum in _Engineering_, 1917, or _Scientific American Supplement_, Oct. 20, 1917; acid-resisting iron in _Sc. Amer. Sup._, May 31, 1919; ferro-alloys in _Jour. Ind. & Eng. Chem._, v. 10, p. 831; influence of vanadium, etc., on iron, in _Met. Chem. Eng._, v. 15, p. 530; tungsten in _Engineering_, v. 104, p. 214. INDEX Abrasives, 249-251 Acetanilid, 87 Acetone, 125, 154, 243, 245 Acetylene, 30, 154, 240-248, 257, 307, 308 Acheson, 249 Air, liquefied, 33 Alcohol, ethyl, 101, 102, 127, 174, 190-194, 242-244, 305 methyl, 101, 102, 127, 191 Aluminum, 31, 246-248, 255, 272, 284 Ammonia, 27, 29, 31, 33, 56, 64, 250 American dye industry, 82 Aniline dyes, 60-92 Antiseptics, 86, 87 Argon, 16 Art and nature, 8, 9, 170, 173 Artificial silk, 116, 118, 119 Aspirin, 84 Atomic theory, 293-296, 299 Aylesworth, 140 Baekeland, 137 Baeyer, Adolf von, 77 Bakelite, 138, 303 Balata, 159 Bauxite, 31 Beet sugar, 165, 169, 305 Benzene formula, 67, 301, 101 Berkeley, 61 Berthelot, 7, 94 Birkeland-Eyde process, 26 Bucher process, 32 Butter, 201, 208 Calcium, 246, 253 Calcium carbide, 30, 339 Camphor, 100, 131 Cane sugar, 164, 167, 177, 180, 305 Carbolic acid, 18, 64, 84, 101, 102, 137 Carborundum, 249-251 Caro and Frank process, 30 Casein, 142 Castner, 246 Catalyst, 28, 204 Celluloid, 128-135, 302 Cellulose, 110-127, 129, 137, 302 Cellulose acetate, 118, 120, 302 Cerium, 288-290 Chemical warfare, 218-235, 307 Chlorin, 224, 226, 250 Chlorophyll, 267 Chlorpicrin, 224, 226 Chromicum, 278, 280 Coal, distillation of, 60, 64, 70, 84, 301 Coal tar colors, 60-92 Cochineal, 79 Coconut oil, 203, 211-215, 306 Collodion, 117, 123, 130 Cologne, eau de, 107 Copra, 203, 211-215, 306 Corn oil, 183, 305 Cotton, 112, 120, 129, 197 Cocain, 88 Condensite, 141 Cordite, 18, 19 Corn products, 181-195, 305 Coslett process, 273 Cottonseed oil, 201 Cowles, 248 Creative chemistry, 7 Crookes, Sir William, 292, 299 Curie, Madame, 292 Cyanamid, 30, 35, 299 Cyanides, 32 Diamond, 259-261, 308 Doyle, Sir Arthur Conan, 221 Drugs, synthetic, 6, 84, 301 Duisberg, 151 Dyestuffs, 60-92 Edison, 84, 141 Ehrlich, 86, 87 Electric furnace, 236-262, 307 Fats, 196-217, 306 Fertilizers, 37, 41, 43, 46, 300 Flavors, synthetic, 93-109 Food, synthetic, 94 Formaldehyde, 136, 142 Fruit flavors, synthetic, 99, 101 Galalith, 142 Gas masks, 223, 226, 230, 231 Gerhardt, 6, 7 Glucose, 137, 184-189, 194, 305 Glycerin, 194, 203 Goldschmidt, 256 Goodyear, 161 Graphite, 258 Guayule, 159, 304 Guncotton, 17, 117, 125, 130 Gunpowder, 14, 15, 22, 234 Gutta percha, 159 Haber process, 27, 28 Hall, C.H., 247 Hare, Robert, 237, 245, 307 Harries, 149 Helium, 236 Hesse, 70, 72, 90 Hofmann, 72, 80 Huxley, 10 Hyatt, 128, 129, 303 Hydrogen, 253-255 Hydrogenation of oils, 202-205, 306 Indigo, 76, 79 Iron, 236, 253, 262-270, 308 Isoprene, 136, 146, 149, 150, 154 Kelp products, 53, 142 Kekulé's dream, 66, 301 Lard substitutes, 209 Lavoisier, 6 Leather substitutes, 124 Leucite, 53 Liebig, 38 Linseed oil, 202, 205, 270 Magnesium, 283 Maize products, 181-196, 305 Manganese, 278 Margarin, 207-212, 307 Mauve, discovery of, 74 Mendeléef, 285, 291 Mercerized cotton, 115 Moissan, 259 Molybdenum, 283, 308 Munition manufacture in U.S., 33, 224, 299, 307 Mushet, 279 Musk, synthetic, 96, 97, 106 Mustard gas, 224, 227-229 Naphthalene, 4, 142, 154 Nature and art, 8-13, 118, 122, 133 Nitrates, Chilean, 22, 24, 30, 36 Nitric acid derivatives, 20 Nitrocellulose, 17, 117 Nitrogen, in explosives, 14, 16, 117, 299 fixation, 24, 25, 29, 299 Nitro-glycerin, 18, 117, 214 Nobel, 18, 117 Oils, 196-217, 306 Oleomargarin, 207-212, 307 Orange blossoms, 99, 100 Osmium, 28 Ostwald, 29, 55 Oxy-hydrogen blowpipe, 246 Paper, 111, 132 Parker process, 273 Peanut oil, 206, 211, 214, 306 Perfumery, Art of, 103-108 Perfumes, synthetic, 93-109, 302 Perkin, W.H., 148 Perkin, Sir William, 72, 80, 102 Pharmaceutical chemistry, 6, 85-88 Phenol, 18, 64, 84, 101, 102, 137 Phonograph records, 84, 141 Phosphates, 56-59 Phosgene, 224, 225 Photographic developers, 88 Picric acid, 18, 84, 85, 226 Platinum, 28, 278, 280, 284, 286 Plastics, synthetic, 128-143 Pneumatic tires, 162 Poisonous gases in warfare, 218-235, 307 Potash, 37, 45-56, 300 Priestley, 150, 160 Purple, royal, 75, 79 Pyralin, 132, 133 Pyrophoric alloys, 290 Pyroxylin, 17, 127, 125, 130 Radium, 291, 295 Rare earths, 286-288, 308 Redmanol, 140 Remsen, Ira, 178 Refractories, 251-252 Resins, synthetic, 135-143 Rose perfume, 93, 96, 97, 99, 105 Rubber, natural, 155-161, 304 synthetic, 136, 145-163, 304 Rumford, Count, 160 Rust, protection from, 262-275 Saccharin, 178, 179 Salicylic acid, 88, 101 Saltpeter, Chilean, 22, 30, 36, 42 Schoop process, 272 Serpek process, 31 Silicon, 249, 253 Smell, sense of, 97, 98, 103, 109 Smith, Provost, 237, 245, 307 Smokeless powder, 15 Sodium, 148, 238, 247 Soil chemistry, 38, 39 Soy bean, 142, 211, 217, 306 Starch, 137, 184, 189, 190 Stassfort salts, 47, 49, 55 Stellites, 280, 308 Sugar, 164-180, 304 Sulfuric acid, 57 Tantalum, 282 Terpenes, 100, 154 Textile industry, 5, 112, 121, 300 Thermit, 256 Thermodynamics, Second law of, 145 Three periods of progress, 3 Tin plating, 271 Tilden, 146, 298 Titanium, 278, 308 TNT, 19, 21, 84, 299 Trinitrotoluol, 19, 21, 84, 299 Tropics, value of, 96, 156, 165, 196, 206, 213, 216 Tungsten, 257, 277, 281, 308 Uranium, 28 Vanadium, 277, 280, 308 Vanillin, 103 Violet perfume, 100 Viscose, 116 Vitamines, 211 Vulcanization, 161 Welding, 256 Welsbach burner, 287-289, 308 Wheat problem, 43, 299 Wood, distillation of, 126, 127 Wood pulp, 112, 120, 303 Ypres, Use of gases at, 221 Zinc plating, 271 _Once a Slosson Reader_ _Always a Slosson Fan_ JUST PUBLISHED CHATS ON SCIENCE By E.E. SLOSSON Author of "Creative Chemistry," etc. Dr. Slosson is nothing short of a prodigy. He is a triple-starred scientist man who can bring down the highest flying scientific fact and tame it so that any of us can live with it and sometimes even love it. He can make a fairy tale out of coal-tar dyes and a laboratory into a joyful playhouse while it continues functioning gloriously as a laboratory. But to readers of "Creative Chemistry" it is wasting time to talk about Dr. Slosson's style. "Chats On Science," which has just been published, is made up of eighty-five brief chapters or sections or periods, each complete in itself, dealing with a gorgeous variety of subjects. They go from Popover Stars to Soda Water, from How Old Is Disease to Einstein in Words of One Syllable. The reader can begin anywhere, but when he begins he will ultimately read the entire series. It is good science and good reading. It contains some of the best writing Dr. Slosson has ever done. The Boston Transcript says: "These 'Chats' are even more fascinating, were that possible, than 'Creative Chemistry.' They are more marvelous than the most marvelous of fairy tales ... Even an adequate review could give little idea of the treasures of modern scientific knowledge 'Chats on Science' contains ... Dr. Slosson has, besides rare scientific knowledge, that gift of the gods--imagination." * * * * * ("Chats on Science" by E.E. Slosson is published by The Century Company, 353 Fourth Avenue, New York City. It is sold for $2.00 at all bookstores, or it may be ordered from the publisher.) FOOTNOTES: [1] I am quoting mostly Unstead's figures from the _Geographical Journal_ of 1913. See also Dickson's "The Distribution of Mankind," in Smithsonian Report, 1913. [2] United States Abstract of Census of Manufactures, 1914, p. 34. [3] United States Department of Agriculture, Bulletin No. 505. 
35597	----	A TREATISE ON THE BREWING OF BEER, &c. &c. _A Saving of Twenty per Cent._ A TREATISE ON THE BREWING OF BEER, WHEREIN IS PROVED That one Bushel of Malt will produce a Gallon of Beer more than another Bushel of an equal Strength, although both Malts be made of one Sort or Species of Barley. In this work will be found some profitable and necessary directions to Maltsters. Improvements in the Brew-house, and Brewing Utensils. Showing the cause what makes hard and sour Beer. Directions for preventing Beer from becoming sour or foxed, even if used in the warmest Season. ALSO Directions in what State to cleanse the Beer, so as to have it fine without using any art or device whatsoever; and for the Management of the Beer in the Cellar. Some Observations in the Choice of HOPS; Proving that they are useful after they have been used in brewing. _The different Experiments are from Twenty Years Practice._ By E. HUGHES. --> Some very useful and necessary directions to the Publican who retails Common Brewer's Beer. SECOND EDITION. UXBRIDGE: PRINTED FOR THE AUTHOR, AND SOLD BY T. LAKE. SOLD ALSO BY E. NEWBERY, ST. PAUL'S CHURCH YARD, LONDON, AND ALL BOOKSELLERS IN TOWN OR COUNTRY. 1796. PREFACE. The first edition of this treatise met with encouragement enough to flatter me that I had left no room to improve it: but, encouraged by the satisfaction my friends was pleased to express of its utility to the public, I have been induced to make every improvement I could collect. Before I presumed to offer this small treatise to the public, the different modes and methods, here recommended, I have proved by different experiments, which I flatter myself will be found of utility, particularly to private families, especially farmers, because their servants have very little knowlege of brewing, their time being so much employed in other business, and so frequently are they changing their employ that they are rendered incapable of being competent in brewing. I do not presume to dictate to those who are proficients; but it must be acknowleged that good malt is frequently marred in brewing by persons who have very little or no knowlege of brewing, and I flatter myself that by a perusal of this treatise it will enable them to be more competent in making the best of the malt intrusted to their care, to the greater satisfaction and benefit of their employers. Waters having a great predominance in brewing, I have given directions in the choice and improvement of them. The improvements in the brewing utensils will be attended with some expence, but the utility arising therefrom will soon make amends. I have taken the liberty to admonish the retailer of common brewer's beer, because, from their inattention in managing the beer after it comes into their stock or possession, the blame, if any, is imputed to the brewer but I am fully convinced to the contrary, from the almost daily practice of the common brewer, and their malt being of the first quality, as country brewers generally make their own malt, and that from the best barley, together with the conveniency of their utensils, enables them to have the advantage of most private families that brew their own beer; therefore it principally depends on the conduct of the publican as to the quality of the beer, after it comes into his stock, or possession. I have taken the liberty to give some directions in the choice of malt, not that I mean to challenge the maltster, or give him directions in the management of his corn, except in the drying. I presume if malt is not attended to on the kiln and perfectly sound dried, it never will produce good and wholesome beer. E. HUGHES. Sep. 3, 1796. A TREATISE. _On Waters._ Waters differ in their quality, that is to say, in extracting the goodness from the Malt; it is, therefore, very necessary for every one who professes the brewing of Beer, to be well acquainted with the nature and quality of the Water he brews with; for as the quality of the water is, so depends the brewing of beer. I am fully persuaded that waters so differ in quality, they will very much add or diminish the quantity and quality of the beer. Well Waters ought not to be used only in cases of necessity, when waters of a softer quality cannot be procured: the well water should be pumped into tubs, or any convenient vessel that is clean and sweet. It is a custom with many to fill the copper a day or two, and sometimes longer, before they begin the operation of brewing, but this I strongly forbid; for a liquid cannot be too short a time in the copper, except it is in a boiling state; my reasons for this I shall point out in another part of this treatise. I would recommend fresh bran to be put into the well water whilst in the tubs, and now and then give it a stir, this will cause a sort of fermentation, and will likewise soften the water. The time for keeping water in the tubs must depend upon the season of the year: if in winter, or moderate cool weather, a week will not be too long; but if in summer, two days will be sufficient. Spring or River Water is far preferable to Well Water, but river or spring waters differ very much in their softness, and that which will lather best with soap is a convincing proof, and is to be prefered for brewing; for, First,--It will leave the grains dryer than well water of a harsher quality. Secondly,--The beer will come to a quicker fermentation in the tun; and, Thirdly,--It will also fine itself much sooner in the cask, than if brewed from well water. Rain Water, such as runs off tiled roofs, is, undoubtedly, to be prefered before well or river water in brewing, being of a simple and soft nature. There is one very great object to the interest of the brewer;--Beer, brewed with rain or river water, will be stronger than beer brewed with well water from an equal quantity of Malt, because it will have a freer access to the Malt; and, as I said before, it will leave the grains much dryer than well water, which is convincing, the dryer the grains are, the better will be the beer. Many persons very much prefer Pond Waters, such that are frequently disturbed by horses and other cattle, which generally causes it to be in a thick muddy state; but the sediments of this thick muddy water must be found prejudicial; for when the wort is emptied out of the cooling tubs into the working tun, or running from the coolers into the tun, a part of the sediment, from the foulness of the water, will follow the wort into the tun, consequently the yeast will be in a foul state and cannot be of that utility in baking, as though the brewing had been from pure clean water. There is a great difficulty often happens in making beer come to a fermentation in the tun; this, I verily believe, is principally owing to the hardness of the water it is brewed with. _Some Observations on the Grinding of Malt._ Much depends on the grinding of Malt. Many people give directions to have their malt ground small, having an idea that the water will mix itself with, and have a more free access to it, than when ground in a more coarser state; but this idea is very erroneous. Malt should be only broke in the Mill, that is, if possible, every corn should be only bruised; malt ground in this manner will discharge the wort in a fine state throughout the whole brewing. I have known many persons neglect giving orders for their malt till the day before they intend to brew; but malt should be ground four or five days, or a week would not be too long for brown malt, but great care must be taken to keep it in a dry place. Malt, ground a reasonable time before it is used, loses the heat which it receives in grinding, and reduces it to a soft and mellow state; it will receive the water more freely, and a greater quantity of wort may be made than if it was brewed immediately after it was ground. The beer will also work much better in the tun and in less time become fit for use than if brewed as soon as it comes from the mill. This is proved by good housekeepers, who have their wheat ground two or three days before they use it; for by losing the heat it receives from the mill in grinding, the flour will be lighter, and receive the yeast and water more freely, than if used immediately from the mill. Brewing is generally left to the care of servants, particularly in farm houses, who frequently have at the same time other business to perform, which too frequently causes the brewing to be neglected, particularly in its first stage. The mash in this first stage determines the whole of the brewing, for the malt ought to be well mixed up with the water, which will cause some time and labour; therefore the person employed in brewing should not, on that day, have any other business to perform, so as to engross any time or attention from the brewing, for any part neglected may mar the whole, which is too frequently the case. _Improvements in the Mash Tun._ Mash Tuns should have false bottoms, to take up as occasion may require;--they should be about two inches clear of the fixed bottom, with holes therein, about a sixth part of an inch in diameter. The false bottom answers two good purposes; First,--You may be more expeditious in mashing, by having a free access to all parts of the mash tun, which, with a tap vase or some such like instrument being in the mash tun, will impede the stirring of the mash, therefore some part of the malt will not be mixed with the water. Secondly,--The false bottom will drain the grains dryer than the tap vase, and in the fixed bottom there will be a sediment left, which, with one bottom only, would have passed through the tap vase, and a part of it accompanied the wort down into the tun. This will answer another good purpose; for the sediment not accompanying the wort into the copper, it will want less boiling, as it will break sooner and fine itself. _Note._ Where the false bottom is used the tap must spend through a cock at the bottom of the tun. The holes in the false bottom may be about three or four inches distance from each other. Fail not to boil your water six or eight minutes, then let it into the mash tun; if time will permit, do not put your malt in for mashing till the steam has escaped and you can see your face in the water; but if time will not admit of this, add about one gallon of cold water to eighteen gallons of hot. Whilst you put your malt into the tun, let a person stir it to prevent its clotting, then well mash it, and let the mash stand two hours at least. The second mash need not stand so long as the first. If convenient, always make use of hot water for your small beer, for by boiling the water a few minutes it will soften it, and will cause it to have a more free access to the malt, and the wort will require less boiling. _Boiling of the Worts._ Many brewers boil their worts from one to two hours; this is very much practised in private families;--a great part of the time the wort is in a simmering state the fire perhaps is not attended to, the person who has the care of the brewing is, as I said before, frequently employed in some other business, therefore this very material part is neglected: As soon as the wort is in the copper it should be made to boil as quick as possible, and a brisk fire should be kept under the copper to cause the wort to boil as fast as possible, for fast boiling will cause the wort to break and fine itself much sooner than it would if kept in a slow boiling state. Thirty or forty minutes will be sufficient to boil ale, and one hour if strong beer. This quick boiling will cause a saving of one gallon in twenty, at least, which must be acknowleged a _great advantage_, considering the present high price of malt. I will presume to say there will be a saving in the wood or coal by boiling the wort, as is commonly said, a gallop, when it rises itself considerably above the copper. The copper should have a curve made of wood, fixed round the brim, to prevent the wort from being spilt when boiling; or the copper should be so hung, with a sheet of lead fixed round the brim in a sloping position, that when the wort is hastily boiling, it would fall on the lead and immediately return into the copper, therefore it would prevent the wort from wasting or boiling over. _Cooling of the Worts._ As soon as the wort is out of the copper the next thing is to get the heat out as soon as possible, and to get it in a state for fermentation. Most private brewers, and many victuallers, separate their worts into tubs, bowls, pans, &c. for cooling; I have seen wort in no less than twelve or sixteen different utensils; worts being of a sticky quality, it must be acknowleged that a loss is sustained by having the wort in so many utensils, and also very inconvenient to pour the wort from the tubs and pans into the working tun; for in each of the before mentioned utensils will be a sediment, which too frequently follows the wort into the working tun. Now to prevent the use of all these small utensils, a brew-house, though ever so small, will admit of two coolers being erected; for two coolers will take up nearly the same room in the brew-house as if only one were to be erected; for one cooler should be nearly underneath the other, so that the second cooler may receive the wort from the first. Care must be taken in fixing the coolers, so as to admit the working tun underneath the coolers, to receive the wort: but this need not be consulted where there is a conveniency to convey the worts and work them in the cellar. _Note._ A victualler is compelled by law not to alter the position of his coolers without giving notice to the excise officer;--now private families have the advantage,--they may have their coolers fixed in the brew-house, or to lay on trestles, and move them to any part, as occasion may require. The size of the coolers must so correspond with the quantity of malt brewed, that in warm weather the worts do not exceed two inches in depth in the coolers; for in summer brewing the heat cannot too soon escape from the worts; and this is the evil--not having a conveniency to separate the worts in a thin state, the brewer has not been able to get the heat out,--he has let the wort down into the working tun in a warm state, which has often brought on the fox, in a short time became sour, and rendered unfit for drinking. The reader will observe that brewing in warm weather ought to be avoided as much as possible; for the coolers or tubs in warm weather being in a very dry state, and the worts being a long time cooling, that, at least, one gallon in forty will exhaust itself. I shall point out one more improvement for cooling the worts more expeditiously: In many brew-houses there is no conveniency, when the worts come out of the copper, for the steam to escape out of the brew-house, but will continue for a time in a thick cloudy state, to the great detriment of the worts:--to remedy this, I would recommend flap shutters to be erected in as many parts of the brew-house as convenient, and the building will admit; the flap shutters will permit the steam to escape and very rapidly cool the worts. These shutters are as convenient in the winter, or when the weather is moderately cool, for they are so contrived that you may set them to what centre you please. From these improvements the brewing will be more expeditiously performed, as the worts will, of course, from this conveniency, much sooner make way for the small beer, and totally prevent its being left in the copper all night, which is too often practised, to the injury of those who drink it, as it will not be fine, but remain in a thick wey colour, which is owing to its being in the copper too long, and not being kept in a boiling state; for if a copper has been in use twenty years it will at times shew symtoms of the verdigrease, which is a sufficient voucher that the wort cannot be too short a time in the copper, except when boiling. Coolers will last many years without repairing; when, on the contrary, cooling tubs, &c. are frequently out of repair, and are as lumber, being of little or no use, except when used in brewing. From the before mentioned improvements you will always finish your brewing before a late hour at night, which will enable you to pay the more attention to the worts in the tuns, &c. Care should be taken to keep the brewing utensils as clean and as sweet as those used in a dairy; for without cleanliness it is impossible to have your beer in a good and wholesome state. The copper should be cleaned after each brewing, as it will keep it bright; when it is used but seldom, and in wet or damp weather, the verdigrease will appear, but care should be taken to examine and clean it, previous to the warier's being put in for brewing. It often happens, where the mash tun is not used for a working tun, the grains are left in the mash tun till the next morning, they will then be in a sour state; therefore the tun should be scalded before the next brewing. If in very warm weather, some quick lime, that is, lime not slacked, will be necessary, by adding some water to dissolve it to the same consistence as used for a white-wash; then with a mop or brush wet the tun with the lime like unto white-washing; after the lime has been on about a day it may be washed off. Much care should be taken to keep the coolers and working tuns in a clean state, by frequently scalding; it will be necessary in warm weather to lime the coolers and working tuns;--this is an excellent remedy where the coolers and tuns are tinged with the fox, as also a preventative against that fulsome complaint. Experience will inform you that the use of lime is excellent in cleaning the utensils. When you soak the coolers, &c. previous to brewing, add some lime to the water, as it will search and purge the joints of the coolers and tubs, by cleaning them from disagreeable smells. Particular attention should be paid to the cooling of the worts, by having coolers as before mentioned. You may let your worts down into the tun as quick or as slow as you please and as the season may require; in very cold weather it should go down into the tun from the cooler by a good stream, as the worts require to go down into the tun in a warm state, particularly when there is but a small quantity brewed. In summer brewing your worts will require to go down into the tun in a cold state; however it will be much the best for them to be cold than too warm, therefore you should set the cock or plug to discharge the worts from the coolers into the tun but slow and dribbling; for by going down slowly it will prevent a hasty fermentation, and consequently will have the good effect to prevent your tun of beer from being foxed; therefore it must be allowed to be convenient and necessary to have coolers erected, as the worts will go down into the tun in almost one regular degree of heat. On the contrary, when worts are cooled in tubs, pans, &c. they are emptied into the working tun in different degrees of heat, one after another; perhaps in some of these cooling tubs or pans the worts are two or three inches in depth; in others, six or seven inches; therefore the worts will be of different degrees of heat, and by having part of the worts let down into the tun much warmer than those already down, and which, perhaps, are in a fermentation, those worts will, of course, cause a fermentation too hastily,--will frequently cause the tun of beer to be foxed, and will always be in a heavy state, for the yeast will not separate itself from the beer; this renders the coolers more necessary and convenient. _Attending the Working Tun._ Attention should be paid to the beer when in the tun. It is a custom with many brewers to put their yeast for that brewing into the tun at one time: I will prove that practice to be very erroneous; for by adding the quantity of yeast you intend to use at one time, may cause a fermentation too hastily, and then you have no remedy. You should feed your tun with yeast by adding a little at a time, as occasion may require, for by so doing you will always be master of your tun of beer, by having it in what state of fermentation you please; as the quality of malt and waters differ, it will require more or less yeast to ferment it, and by adding the yeast at different times you will be enabled to form such a judgment as never to over-yeast your tun. Every time you add more yeast you should stir your beer with a bowl or bucket. _Cleansing._ It is a practice with many people to keep their beer in the tun from four to six days; by that time the yeast will fall to the bottom of the tun, and the beer will be in a flat, dead state; it will always be _heady_ beer, being kept so long before it is cleansed; it will not be inclined to work in the casks, nor will it drink with a pleasant, lively taste. There is no coming at any exact time, with respect to hours, when your beer will be ready to cleanse, therefore this must be done by attention, in frequently examining when your beer is at its full head of working, or what is commonly said, rather inclined to go back; when it is in that state it should be cleansed immediately. This, I say, should be attended to, notwithstanding it should happen at twelve o'clock at night; for this is the evil, by neglecting the proper time to cleanse your beer it will not be able to fine itself in the casks, and then some device must be used to fine it, which is too often injurious to the beer. _A very necessary Caution._ It is a common practice, when casks are scalded or cleansed, to expose them to the sun and wind to dry, and there leave them till the time of cleansing, then they are placed in the cellar, &c. and the beer immediately cleansed into them; when the sun, in warm weather, has penetrated through the wood and become so warm that you cannot conveniently lay your hand upon them; this is often done unthinkingly, but the casks being thus heated by the sun causes the beer to work too hastily; after all the care and pains before taken, it here receives a material injury, by having, as may be said, undergone a second fermentation, and will reduce its strength by working too hastily out of the casks, and very probably may be the cause of its not being soft and pleasant; however, care should be taken to get your casks perfectly dry, previous to the cleansing into them; in hot weather place them in the cellar, &c. some time before you have occasion to cleanse your beer into them. Attention should be paid in keeping your casks filled up after cleansing, to enable the yeast to discharge itself from the beer, for by so doing there will be the greater probability of your beer being fine; if the casks are not kept filled up when working, the yeast cannot discharge itself from the beer, which, in change of weather, will be purging and hissing in the casks, and will cause it to be harsh and unpleasant; this is the principal cause why we have so many muddy ales. Attending your beer when working, by filling up the casks, will be found to be of the greatest utility, as you will have no occasion to use any device to fine your beer, which will only attend to adulteration. _Small Beer._ As I said before, small beer is too frequently neglected, because the master or mistress of a family drink but a small quantity of it. I verily believe there would be less _good_ small beer consumed in a family of servants and workmen, than if it were inferior and bad in its quality. It may be thought strange by adding the name of _good_ to small beer, but it must be acknowleged that there is a great disparity in the quality of ales, and why not in small beer; on the one hand, it certainly depends on what length you draw from quantity of malt. Small beer should be let down into the tun much warmer than ale; and as soon as it shews an inclination to work it should be cleansed; it will then work well in the casks, and will have a quick, lively taste. Small beer, not having a sufficient strength, cannot support a long fermentation in the tun: for if it is worked cold, and left too long in the tun, it will drink flat and unpleasant. Now, as I said before, there will be no more _good_ small beer consumed in a family, than if it were ever so _bad_; for when a workman or servant has occasion for a pot of small beer, if bad, he will, perhaps, drink a part of it, and throw the remainder away, and, very likely, carelessly leave the cock dropping, in order to get rid of such a bad commodity the sooner. Now, on the other hand, if the small beer was _good_, the consumers would take care to leave the cock, &c. secure, well knowing they should not have a better substitute. _Cleanliness in the Cellar._ Care should be taken to keep the cellar clean, (especially those who are situated near the south aspect; or shallow, where the sun has any power,) by scraping the yeast from the bung-holes of the casks; else in warm weather it will smell offensive, and insects will breed therein, which must be injurious to the beer, if the bung-holes are open. The dropping of the cock, tap tubs, &c. will cause fulsome smells in the cellar, which frequently require to be washed down; for washing and cleaning your cellar often, will keep your beer in a cool state, and will be the means of preventing mild ale from becoming stale. Put some hops into your ale and small beer casks a few days before you want to tap them for use; even those hops that have already been used in brewing will be found serviceable in fining your beer, and will not cause it to be too bitter, but will prevent your small beer from becoming sour. Notwithstanding their being used in brewing, they will be found by experience to be very serviceable for the purpose before mentioned. Another advantage will arise, they will serve the use of fresh hops, which, when dear, will be found to be a considerable saving. _Note._ They are recommended for beer that is for present drinking, as they cannot be expected to be sufficient for beer intended for a long standing. Another advantage will be found when a length of ale is brewed, and no small beer made, the hops will then be found of greater utility, as they will contain the same quality as the ale they were brewed with; consequently the ale and small beer they are put into will receive a greater advantage therefrom. This may not seem consistent, as mild ales and small beer seldom have any hops put into the casks; but when a cask of beer is a considerable time at tap, it will certainly want something to feed on; this is one cause why small beer generally turns sour when it is nearly out; now by using the before mentioned hops it will be found to be a considerable remedy to prevent both mild ales and small beer from being hard and unpleasant. The reader will observe, these hops having performed their duty, they are of no expense, only the trouble of putting them into the casks. The small beer must derive a considerable advantage from those hops when a guile of ale was only brewed from them. Take care to put them into the casks as soon as they are cold, for by being too long exposed to the air they will lose their virtue. I should not have said so much concerning small beer, but the price of malt is so considerably advanced, to what it was formerly, that small beer is become an expensive article, where there is a numerous family. If you observe the before mentioned directions you will not have your small beer so unpleasant, particularly when your cask is nearly out. The most wholesome small beer is made from an intire guile of small, for then you have the whole of the spirit and sweetness of the malt; it will keep better and drink much fresher than if it were to be made from the goods after a length of ale. If you rack your beer, fail not to put some hops into the casks, wetting them first with some of the same beer, or rather wet the hops with some wort when brewing. If you want to hasten your beer for drinking, put the hops into the casks when they are warm; if your beer is for a long standing, put the hops in your casks when they are cold, giving them a stir to separate them in the beer. Take care not to be under the necessity of tapping your ale or small beer before it has actually done working, for by so doing you will prevent it from becoming fine: new beer may be classed with new bread; for the newer you draw your beer the more there will be consumed; new beer is not so satisfying as it is when come to a more mature age. Beware, lest you forget to pay attention to your beer which is at tap; for, "as the eye of the master maketh his horse fat," so the head of a family, now and then giving a look into his cellar, may be the cause of beer drinking more agreeable to his palate, by taking care the vent-holes are kept closely stopped, and the cocks secure. Do not fail to stoop your cask when the beer is about two parts in three out; this should be done whilst the tap is spending, for then you will not disturb the sediment. By stooping the cask when the beer is about two parts in three out will prevent it from becoming flat and sour; when, on the other hand, it is too frequently to be observed when a person is drawing a pot of beer, the stream is impeded; for the beer, being so nearly out, will not run till it is stooped. Now before this, the cock discharging the beer but slowly, the air is admitted into the cask, which causes the beer to drink flat, and, perhaps, turn sour: therefore this will enforce the necessity of stooping your cask before it be so nearly out. This is a fault with many publicans, not paying attention to their cellars; even many of those who brew their own beer are neglectful, notwithstanding their own interest and credit is concerned. Tis not uncommon for the vent-peg, and even the bung, to be left out of those casks which are actually on draught. Publicans, who retail common brewer's beer, and neglect their cellars, have this excuse, if their customers find fault with the beer, by saying "tis such beer as my brewer sends me," so it may be; but let a publican be served with beer of the first quality, it entirely depends on the management of the retailer thereof, whether the beer shall be of a good or bad quality. This is proved by persons in the same town, each being served with beer from one and the same brew-house; there will be generally a disparity in the quality after it comes into the stock of the respective retailers thereof, which proves it to be the good or bad management in the cellar. I am convinced I shall not offend the _attentive_ publican by what I have said respecting the cellar; but should this fall into the hands of the _inattentive_, it may offend; but that I will excuse, if, by the reading of this, he should be convinced of his error, and pay more attention to his cellar; that he may be enabled to draw a pot of beer to please those useful and valuable men, the labourer and the mechanic; and where they used to drink but one pot of beer with him, they may, from finding his ale much better than usual, perhaps, drink two. _On the drying and qualities of Malt._ I shall here give a few observations on malt, which was my principal reason for introducing this work to the public, well knowing that many who profess the art of brewing have very little knowlege of the nature and quality of the malt and hops they brew with. Malt is dried with coke, coal, wood, furze, and straw. The best and sweetest malt is dried with coke, or welch coal; because the coke, or coal, gives a regular and gradual heat. Malt dried with coke, or coal, will be of a bright, clean colour, because the fire is free from smoak. It is also to be observed that malt dried with coal, or coke, is generally well cured, that is, sound dried, because the coke or coal fire is fierce and strong. If malt is dried with a wood fire it greatly depends on the wood being housed in a dry season; for if the wood is dry it will produce a clear fire, free from smoak, and the malt will be of a bright colour; but if the wood is wet and sugged, the fire will not be fierce, but will be smoaky, and will certainly cause the malt to be of a dull colour; and the beer brewed from such malt will consequently have a smoaky taste: therefore it depends on the attention of the maltster, in housing his wood in good order, for without that attention he cannot serve his customers with good, bright, well cured malt. I have seen very fine malt dried with straw, it being less subject to smoak than malt dried with wood; but this mode of drying is very tedious, because a person must always attend the fire. In those countries where it is straw-dried, wood and coal is dear, therefore straw is used as a substitute for coal, &c. However, if care be taken, malt may be well cured with a straw or wood fire, but not to equal welch coal, or coke, because the fire may always be kept up so as to produce a regular heat. Fuel being much dearer than formerly many maltsters are too sparing of their fire; and here arises the principal cause why we have so much bad beer; for if malt is not well cured, that is, sound dried, it will not produce good and wholesome beer. Malt may appear to be of a fine amber colour, and this may be done by making a strong fire a few minutes before the kiln is shifted, therefore the colour is not at all times a rule for its being well dried. No malt should be used till it has been off the kiln a month, at least; at the end of that time, if the malt bites quick and crisp, you may conclude it is well dried. It will be very necessary when you give orders for a brewing of malt, to request your maltster to send the malt well dried; this caution may induce him to pay more attention in the drying of his malt. When a brewing of malt is ordered by private families, perhaps no order is given respecting any particular sort, that is to say, whether pale, amber, or brown, for these are the three sorts of malt; but many retail maltsters in the country have but one sort of malt, and, in fact, one sort is sufficient, provided care is taken to dry their malt sound, of a fine amber colour. Now I again repeat that the principal reason of our having so much hard and sour beer, is owing to the malt being under dried; for malt is the fundamental article in brewing. If a guile of beer is made from under dried malt it will not be of a fine bright colour, and an extra boiling of the worts will not have the desired effect: then you are under the necessity of using finings and other nostrums, which are only temporary, for no other ingredients whatever can be so beneficial to beer as malt and hops, and if those two commodities are in a good and genuine state, you will not have occasion to seek for any other art or device whatever. Another considerable advantage will arise, for each bushel of sound dried malt will produce a gallon of wort more than slack or under dried malt; this is proved by brewing two sorts of malt, that is, malt perfectly dried will discharge the wort freely, and the grains will be dry and light; when, on the other hand, if a brewing of beer is made from under dried malt, the grains will be clammy and heavy, owing to the raw state of the malt, therefore a part of the wort cannot discharge itself, which is a sufficient voucher that the perfectly dried malt will produce a greater quantity of wort of an equal degree of strength. I hinted before that malt should not be brewed till it has been off the kiln a month; but if malt is six or seven months old it will be the better, because it will become mellow, and your beer will be much softer and better than if used immediately from the kiln. Between michaelmas and christmas the retail maltster's stock of old malt generally lays in a small compass, and will be slack; I should at this season recommend part old and part new, for the one will help the other. _On Hops._ Many professed brewers are particularly attached to the colour of the hops, that is, they are partial to those of a fine green colour; these are certainly to be prefered, if they were ripe when gathered:--to prove their goodness, rub them between your fingers, if they are in full condition they will stick to your fingers, will have a good strong scent, and the seeds will appear full and yellow. Brown spots are frequently to be seen on hops; these are, in general, hops that came to a full ripeness before they were gathered. High winds and rain frequently happen about the middle or latter end of the hop season, which will disfigure them in their colour in a few hours, so that the colour is not at all times to direct you as to their goodness. In the hop countries most hop-planters keep those hops which are most disfigured in their quality, separate and apart, when picking, from those of a brighter colour; those which are of an inferior colour are kept for their own use, and disposed of to their neighbours, it being their opinion that they answer the purpose in brewing nearly as well as those of a brighter colour, provided they are in full condition, that is, if they are full of seeds; for in the seeds is the virtue and strength of the hop. The quantity of hops used in brewing is generally half a pound to a bushel of malt, and so in proportion to a greater quantity; if mild ale, for present drinking, a lesser quantity will do; but this must be left to the discretion of the brewer, or master of a family, as some are more partial to the taste of the hop than others. Hops are found to be of such excellent utility in the bittering of beer, that common brewers and innkeepers are forbidden by law to use any other bitter ingredient whatever in brewing of beer and ale. I have taken the liberty to insert this as a caution to the unwary. As to the quantity of beer each bushel of malt should produce, it must rest on the option or circumstances of the brewer, or the head of a family. A bushel of malt will produce ten gallons of good ale; but the greater the quantity of malt, brewed at one time, the better will be your beer. 
8900	----	THE LONDON and COUNTRY BREWER By Anonymous 1736 Containing an Account, I. Of the Nature of the Barley-Corn, and of the proper Soils and Manures for the Improvement thereof. II. Of making good Malts. III. To know good from bad Malts. IV. Of the Use of the Pale, Amber, and Brown Malts. V. Of the Nature of several Waters, and their Use in Brewing. VI. Of Grinding Malts. VII. Of Brewing in general. VIII. Of the _London_ Method of Brewing Stout, But-Beer, Pale and Brown Ales. IX. Of the Country or Private Way of Brewing. X. Of the Nature and Use of the Hop. XI. Of Boiling Malt liquors, and to Brew a Quantity of Drink in a little Room, and with a few Tubs. XII. Of Foxing or Tainting of Malt Liquors; their Prevention and Cure. XIII. Of Fermenting and Working of Beers and Ales, and the unwholesome Practice of Beating in the Yeast, detected. XIV. Of several artificial Lees for feeding, fining, preserving, and relishing Malt Liquors. XV. Of several pernicious Ingredients put into Malt Liquors to encrease their Strength. XVI. Of the Cellar or Repository for keeping Beers and Ales. XVII. Of Sweetening and Cleaning Casks. XVIII. Of Bunging Casks and Carrying them to some Distance. XIX. Of the Age and Strength of Malt Liquors. XX. Of the Profit and Pleasure of Private Brewing and the Charge of Buying Malt Liquors. To which is added, XXI. A Philosophical Account of Brewing Strong _October_ Beer. By an Ingenious Hand. By a Person formerly concerned in a Common Brewhouse at _London_, but for twenty Years past has resided in the Country. The SECOND EDITION, Corrected. LONDON Printed for Messeurs Fox, at the _Half-Moon and Seven Stars_, in _Westminster-Hall_. M.DCC.XXXVI. [Price Two Shillings.] THE PREFACE. The many Inhabitants of Cities and Towns, as well as Travellers, that have for a long time suffered great Prejudices from unwholsome and unpleasant Beers and Ales, by the badness of Malts, underboiling the Worts, mixing injurious Ingredients, the unskilfulness of the Brewer, and the great Expense that Families have been at in buying them clogg'd with a heavy Excise, has moved me to undertake the writing of this Treatise on Brewing, Wherein I have endeavour'd to set in sight the many advantages of Body and Purse that may arise from a due Knowledge and Management in Brewing Malt Liquors, which are of the greatest Importance, as they are in a considerable degree our Nourishment and the common Diluters of our Food; so that on their goodness depends very much the Health and Longevity of the Body. This bad Economy in Brewing has brought on such a Disrepute, and made our Malt Liquors in general so odious, that many have been constrain'd, either to be at an Expence for better Drinks than their Pockets could afford, or take up with a Toast and Water to avoid the too justly apprehended ill Consequences of Drinking such Ales and Beers. Wherefore I have given an Account of Brewing Beers and Ales after several Methods; and also several curious Receipts for feeding, fining and preserving Malt Liquors, that are most of them wholsomer than the Malt itself, and so cheap that none can object against the Charge, which I thought was the ready way to supplant the use of those unwholsome Ingredients that have been made too free with by some ill principled People meerly for their own Profit, tho' at the Expence of the Drinker's Health. _I hope I have adjusted that long wanted Method of giving a due Standard both to the Hop and Wort, which never was yet (as I know of) rightly ascertain'd in Print before, tho' the want of it I am perswaded has been partly the occasion of the scarcity of good Drinks, as is at this time very evident in most Places in the Nation. I have here also divulg'd the Nostrum of the Artist Brewer that he has so long valued himself upon, in making a right Judgment when the Worts are boiled to a true Crisis; a matter of considerable Consequence, because all strong Worts may be boiled too much or too little to the great Loss of the Owner, and without this Knowledge a Brewer must go on by Guess; which is a hazard that every one ought to be free from that can; and therefore I have endeavor'd to explode the old Hour-glass way of Brewing, by reason of the several Uncertainties that attend such Methods and the hazard of spoiling both Malt and Drink; for in short where a Brewing is perform'd by Ladings over of scalding Water, there is no occasion for the Watch or Hour-glass to boil the Wort by, which is best known by the Eye, as I have both in this and my second Book made appear. I have here observed that necessary Caution, which is perfectly requisite in the Choice of good and the Management of bad Waters; a Matter of high Importance, as the Use of this Vehicle is unavoidable in Brewing, and therefore requires a strict Inspection into its Nature; and this I have been the more particular in, because I am sensible of the great Quantities of unwholsome Waters used not only by Necessity, but by a mistaken Choice. So also I have confuted the old received Opinion lately published by an Eminent Hand, that long Mashings are the best Methods in Brewing; an Error of dangerous Consequence to all those who brew by Ladings over of the hot Water on the Malt. The great Difficulty and what has hitherto proved an Impediment and Discouragement to many from Brewing their own Drinks, I think, I have in some measure removed, and made it plainly appear how a Quantity of Malt Liquor may be Brewed in a little Room and in the hottest Weather, without the least Damage by Foxing or other Taint. The Benefit of Brewing entire Guile small Beer from fresh Malt, and the ill Effects of that made from Goods after strong Beer or Ale; I have here exposed, for the sake of the Health and Pleasure of those that may easily prove their advantage by drinking of the former and refusing the latter. By the time the following Treatise is read over and thoroughly considered, I doubt not but an ordinary Capacity will be in some degree a better Judge of good and bad Malt Liquors as a Drinker, and have such a Knowledge in Brewing that formerly he was a stranger to; and therefore I am in great Hopes these my Efforts will be one Principal Cause of the reforming our Malt Liquors in most Places; and that more private Families than ever will come into the delightful and profitable Practice of Brewing their own Drinks, and thereby not only save almost half in half of Expence, but enjoy such as has passed thro' its regular Digestions, and is truly pleasant, fine, strong and healthful. I Question not but this Book will meet with some Scepticks, who being neither prejudiced against the Introduction of new Improvements, or that their Interests will be hereby eclipsed in time; To such I say I do not write, because I have little hopes to reform a wrong Practice in them by Reason and Argument. But those who are above Prejudice may easily judge of the great Benefits that will accrue by the following Methods, I have here plainly made known, and of those in my Second Book that I have almost finished and hope to publish in a little time, wherein I shall set forth how to Brew without boiling Water or Wort, and several other Ways that will be of considerable Service to the World._ [Illustration] CHAP. I. _Of the Nature of the Barley-Corn, and of the proper Soils and Manures for the Improvement thereof_. This Grain is well known to excel all others for making of Malts that produce those fine _British_ Liquors, Beer and Ale, which no other Nation can equalize; But as this Excellency cannot be obtain'd unless the several Ingredients are in a perfect State and Order, and these also attended with a right judgment; I shall here endeavour to treat on their several particulars, and first of Soils. This Grain I annually sow in my Fields on diversities of Soils, and thereby have brought to my knowledge several differences arising therefrom. On our Red Clays this Grain generally comes off reddish at both ends, and sometimes all over, with a thick skin and tuff nature, somewhat like the Soil it grows in, and therefore not so valuable as that of contrary qualities, nor are the black blewish Marly Clays of the Vale much better, but Loams are, and Gravels better than them, as all the Chalks are better then Gravels; on these two last Soils the Barley acquires a whitish Body, a thin skin, a short plump kernel, and a (unreadable) flower, which occasions those, fine pale and amber Malts made at _Dunstable_, _Tring_ and _Dagnal_ from the Barley that comes off the white and gravelly Grounds about those Places; for it is certain there is as much difference in Barley as in Wheat or other Grain, from the sort it comes off, as appears by the excellent Wheats that grow in the marly vale Earths, Peas in Sands, and Barley in Gravels and Chalks, &c. For our Mother Earth, as it is destinated to the service of Man in the production of Vegetables, is composed of various sorts of Soils for different Seeds to grow therein. And since Providence has been pleased to allow Man this great privilege for the imployment of his skill and labour to improve the same to his advantage; it certainly behoves us to acquaint ourselves with its several natures, and how to adapt an agreeable Grain and Manure to their natural Soil, as being the very foundation of enjoying good and bad Malts. This is obvious by parallel Deductions from Turneps sown on rank clayey loamy Grounds, dressed with noxious Dungs that render them bitter, tuff, and nauseous, while those that grow on Gravels, Sands and Chalky Loams under the assistance of the Fold, or Soot, Lime, Ashes, Hornshavings, &c. are sweet (unreadable) and pleasant. 'Tis the same also with salads, Asparagus, Cabbages, Garden-beans and all other culinary Ware, that come off those rich Grounds glutted with the great quantities of _London_ and other rank Dungs which are not near so pure, sweet and wholsome, as those produced from Virgin mould and other healthy Earths and Manures. There is likewise another reason that has brought a disreputation on some of the Chiltern-barley, and that is, the too often sowing of one and the same piece of Ground, whereby its spirituous, nitrous and sulphureous qualities are exhausted and worn out, by the constant attraction of its best juices for the nutriment of the Grain: To supply which, great quantities of Dungs are often incorporated with such Earths, whereby they become impregnated with four, adulterated, unwholsome qualities, that so affect the Barley that grows therein, as to render it incapable of making such pure and sweet Malts, as that which is sown in the open Champaign-fields, whose Earths are constantly rested every third Year called the Fallow-season, in order to discharge their crude, phlegmatick and sour property, by the several turnings that the Plough gives them part of a Winter and one whole Summer, which exposes the rough, clotty loose parts of the Ground, and by degrees brings them into a condition of making a lodgment of those saline benefits that arise from the Earths, and afterwards fall down, and redound so much to the benefit of all Vegetables that grow therein, as being the essence and spring of Life to all things that have root, and tho' they are first exhaled by the Sun in vapour from the Earth as the spirit or breath thereof, yet is it return'd again in Snows, Hails, Dews, etc. more than in Rains, by which the surface of the Globe is saturated; from whence it reascends in the juices of Vegetables, and enters into all those productions as food, and nourishment, which the Creation supplies. Here then may appear the excellency of steeping Seed-barley in a liquor lately invented, that impregnates and loads it with Nitre and other Salts that are the nearest of all others to the true and original Spirit or Salt of the Earth, and therefore in a great measure supplies the want thereof both in inclosure and open Field; for even in this last it is sometimes very scarce, and in but small quantities, especially after a hot dry Summer and mild Winter, when little or no Snows have fell to cover the Earth and keep this Spirit in; by which and great Frosts it is often much encreased and then shews itself in the warmth of well Waters, that are often seen to wreak in the cold Seasons. Now since all Vegetables more or less partake of those qualities that the Soil and Manures abound with in which they grow; I therefore infer that all Barley so imbibed, improves its productions by the ascension of those saline spirituous particles that are thus lodged in the Seed when put into the Ground, and are part of the nourishment the After-Crop enjoys; and for this reason I doubt not, but when time has got the ascendant of prejudice, the whole Nation will come into the practice of the invaluable Receipt published in two Books, entituled, _Chiltern and Vale Farming Explained_, and, _The Practical Farmer_; both writ by _William Ellis_ of _Little Gaddesden_ near _Hempstead_ in _Hertfordshire_, not only for Barley, but other Grains. But notwithstanding Barley may grow on a light Soil with a proper Manure; and improved by the liquor of this Receipt, yet this Grain may be damaged or spoiled by being mown too soon, which may afterwards be discovered by its shrivelled and lean body that never will make right good Malt; or if it is mown at a proper time, and if it be housed damp, or wettish, it will be apt to heat and mow-burn, and then it will never make so good Malt, because it will not spire, nor come so regularly on the floor as that which was inned dry. Again, I have known one part of a Barley-crop almost green at Harvest, another part ripe, and another part between both, tho' it was all sown at once, occasion'd by the several situations of the Seed in the Ground, and the succeeding Droughts. The deepest came up strong and was ripe soonest, the next succeeded; but the uppermost, for want of Rain and Cover, some of it grew not at all, and the rest was green at Harvest. Now these irregularities are greatly prevented and cured by the application of the ingredients mentioned in the Receipt, which infuses such a moisture into the body of the Seed, as with the help of a little Rain and the many Dews, makes it spire, take root and grow, when others are ruined for want of the assistance of such steeping. Barley like other Grain will also degenerate, and become rank, lean and small bodied, if the same Seed is sown too often in the Soil; 'tis therefore that the best Farmers not only change the Seed every time, but take due care to have it off a contrary Soil that they sow it in to; this makes several in my neighbourhood every Year buy their Barley-seed in the Vale of _Ailsbury_, that grew there on the black clayey marly Loams, to sow in Chalks, Gravels, &c. Others every second Year will go from hence to _Fullham_ and buy the Forward or Rath-ripe Barley that grows there on Sandy-ground; both which Methods are great Improvements of this Corn, and whether it be for sowing or malting, the plump, weighty and white Barley-corn, is in all respects much kinder than the lean flinty Sorts. CHAP. II _Of making_ Malts. As I have described the Ground that returns the best Barley, I now come to treat of making it into Malt; to do which, the Barley is put into a leaden or tyled Cistern that holds five, ten or more Quarters, that is covered with water four or six Inches above the Barley to allow for its Swell; here it lyes five or six Tides as the Malster calls it, reckoning twelve Hours to the Tide, according as the Barley is in body or in dryness; for that which comes off Clays, or has been wash'd and damag'd by Rains, requires less time than the dryer Grain that was inned well and grew on Gravels or Chalks; the smooth plump Corn imbibing the water more kindly, when the lean and steely Barley will not so naturally; but to know when it is enough, is to take a Corn end-ways between the Fingers and gently crush it, and if it is in all parts mellow, and the husk opens or starts a little from the body of the Corn, then it is enough: The nicety of this is a material Point; for if it is infus'd too much, the sweetness of the Malt will be greatly taken off, and yield the less Spirit, and so will cause deadness and sourness in Ale or Beer in a short time, for the goodness of the Malt contributes much to the preservation of all Ales and Beers. Then the water must be drain'd from it very well, and it will come equal and better on the floor, which may be done in twelve or sixteen Hours in temperate weather, but in cold, near thirty. From the Cistern it is put into a square Hutch or Couch, where it must lye thirty Hours for the Officer to take his Gage, who allows four Bushels in the Score for the Swell in this or the Cistern, then it must be work'd Night and Day in one or two Heaps as the weather is cold or hot, and turn'd every four, six or eight Hours, the outward part inwards and the bottom upwards, always keeping a clear floor that the Corn that lies next to it be not chill'd; and as soon as it begins to come or spire, then turn it every three, four or five Hours, as was done before according to the temper of the Air, which greatly governs this management, and as it comes or works more, so must the Heap be spreaded and thinned larger to cool it. Thus it may lye and be work'd on the floor in several parallels, two or three Foot thick, ten or more Foot broad, and fourteen or more in length to Chip and Spire; but not too much nor too soft; and when it is come enough, it is to be turned twelve or sixteen times in twenty-four Hours, if the Season is warm, as in _March, April_ or _May_; and when it is fixed and the Root begins to be dead, then it must be thickned again and carefully kept often turned and work'd, that the growing of the Root may not revive, and this is better done with the Shoes off than on; and here the Workman's Art and Diligence in particular is tryed in keeping the floor clear and turning the Malt often, that it neither moulds nor Aker-spires, that is, that the Blade does not grow out at the opposite end of the Root; for if it does, the flower and strength of the Malt is gone, and nothing left behind but the Aker-spire, Husk and Tail: Now when it is at this degree and fit for the Kiln, it is often practised to put it into a Heap and let it lye twelve Hours before it is turned, to heat and mellow, which will much improve the Malt if it is done with moderation, and after that time it must be turned every six Hours during twenty four; but if it is overheated, it will become like Grease and be spoiled, or at least cause the Drink to be unwholsome; when this Operation is over, it then must be put on the Kiln to dry four, six or twelve Hours, according to the nature of the Malt, for the pale sort requires more leisure and less fire than the amber or brown sorts: Three Inches thick was formerly thought a sufficient depth for the Malt to lye on the Hair-cloth, but now six is often allowed it to a fault; fourteen or sixteen Foot square will dry about two Quarters if the Malt lyes four Inches thick, and here it should be turned every two, three or four Hours keeping the Hair-cloth clear: The time of preparing it from the Cistern to the Kiln is uncertain; according to the Season of the Year; in moderate weather three Weeks is often sufficient. If the Exciseman takes his Gage on the floor he allows ten in the Score, but he sometimes Gages in Cistern, Couch, Floor and Kiln, and where he can make most, there he fixes his Charge: When the Malt is dryed, it must not cool on the Kiln, but be directly thrown off, not into a Heap, but spreaded wide in an airy place, till it is thoroughly cool, then put it into a Heap or otherwise dispose of it. There are several methods used in drying of Malts, as the Iron Plate-frame, the Tyle-frame, that are both full of little Holes: The Brass-wyred and Iron-wyred Frame, and the Hair-cloth; the Iron and Tyled one, were chiefly Invented for drying of brown Malts and saving of Fuel, for these when they come to be thorough hot will make the Corns crack and jump by the fierceness of their heat, so that they will be roasted or scorch'd in a little time, and after they are off the Kiln, to plump the body of the Corn and make it take the Eye, some will sprinkle water over it that it may meet with the better Market. But if such Malt is not used quickly, it will slacken and lose its Spirits to a great degree, and perhaps in half a Year or less may be taken by the Whools and spoiled: Such hasty dryings or scorchings are also apt to bitter the Malt by burning its skin, and therefore these Kilns are not so much used now as formerly: The Wyre-frames indeed are something better, yet they are apt to scorch the outward part of the Corn, that cannot be got off so soon as the Hair-cloth admits of, for these must be swept, when the other is only turned at once; however these last three ways are now in much request for drying pale and amber Malts, because their fire may be kept with more leisure, and the Malt more gradually and truer dyed, but by many the Hair-cloth is reckoned the best of all. Malts are dryed with several sorts of Fuel; as the Coak, Welch-coal, Straw, Wood and Fern, &c. But the Coak is reckoned by most to exceed all others for making Drink of the finest Flavour and pale Colour, because it sends no smoak forth to hurt the Malt with any offensive tang, that Wood, Fern and Straw are apt to do in a lesser or greater degree; but there is a difference even in what is call'd Coak, the right sort being large Pit-coal chark'd or burnt in some measure to a Cinder, till all the Sulphur is consumed and evaporated away, which is called Coak, and this when it is truly made is the best of all other Fuels; but if there is but one Cinder as big as an Egg, that is not thoroughly cured, the smoak of this one is capable of doing a little damage, and this happens too often by the negligence or avarice of the Coak-maker: There is another sort by some wrongly called Coak, and rightly named Culme or Welch-coal, from _Swanzey_ in _Pembrokeshire_, being of a hard stony substance in small bits resembling a shining Coal, and will burn without smoak, and by its sulphureous effluvia cast a most excellent whiteness on all the outward parts of the grainy body: In _Devonshire_ I have seen their Marble or grey Fire-stone burnt into Lime with the strong fire that this Culme makes, and both this and the Chark'd Pit-coal affords a most sweet moderate and certain fire to all Malt that is dryed by it. Straw is the next sweetest Fuel, but Wood and Fern worst of all. Some I have known put a Peck or more of Peas, and malt them with five Quarters of Barley, and they'll greatly mellow the Drink, and so will Beans; but they won't come so soon, nor mix so conveniently with the Malt, as the Pea will. I knew a Farmer, when he sends five Quarters of Barley to be Malted, puts in half a Peck or more of Oats amongst them, to prove he has justice done him by the Maker, who is hereby confin'd not to Change his Malt by reason others won't like such a mixture. But there is an abuse sometimes committed by a necessitous Malster, who to come by Malt sooner than ordinary, makes use of Barley before it is thoroughly sweated in the Mow, and then it never makes right Malt, but will be steely and not yield a due quantity of wort, as I knew it once done by a Person that thrashed the Barley immediately from the Cart as it was brought out of the Field, but they that used its Malt suffered not a little, for it was impossible it should be good, because it did not thoroughly Chip or Spire on the floor, which caused this sort of Malt, when the water was put to it in the Mash-tub, to swell up and absorb the Liquor, but not return its due quantity again, as true Malt would, nor was the Drink of this Malt ever good in the Barrel, but remain'd a raw insipid beer, past the Art of Man to Cure, because this, like Cyder made from Apples directly off the Tree, that never sweated out their phlegmatick crude juice in the heap, cannot produce a natural Liquor from such unnatural management; for barley certainly is not fit to make Malt of until it is fully mellowed and sweated in the Mow, and the Season of the Year is ready for it, without both which there can be no assurance of good Malt: Several instances of this untimely making Malt I have known to happen, that has been the occasion of great quantities of bad Ales and Beers, for such Malt, retaining none of its Barley nature, or that the Season of the Year is not cold enough to admit of its natural working on the Floor, is not capable of producing a true Malt, it will cause its Drink to stink in the cask instead of growing fit for use, as not having its genuine Malt-nature to cure and preserve it, which all good Malts contribute to as well as the Hop. There is another damage I have known accrue to the Buyer of Malt by Mellilet, a most stinking Weed that grows amongst some Barley, and is so mischievously predominant, as to taint it to a sad degree because its black Seed like that of an Onion, being lesser than the Barley, cannot be entirely separated, which obliges it to be malted with the Barley, and makes the Drink so heady that it is apt to fuddle the unwary by drinking a small quantity. This Weed is so natural to some Ground that the Farmer despairs of ever extirpating it, and is to be avoided as much as possible, because it very much hurts the Drink that is made from Malt mixed with it, by its nauseous Scent and Taste, as may be perceived by the Ointment made with it that bears its Name: I knew a Victualler that bought a parcel of Malt that this weed was amongst, and it spoiled all the Brewings and Sale of the Drink, for it's apt to cause Fevers, Colicks and other Distempers in the Body. Darnel is a rampant Weed and grows much amongst some Barley, especially in the bad Husbandman's Ground, and most where it is sown with the Seed-barley: It does the least harm amongst Malt, because it adds a strength to it, and quickly intoxicates, if there is much in it; but where there is but little, the Malster regards it not, for the sake of its inebriating quality. There are other Weeds or Seeds that annoy the Barley; but as the Screen, Sieve and throwing will take most of them out, there does not require here a Detail of their Particulars. Oats malted as Barley is, will make a weak, soft, mellow and pleasant Drink, but Wheat when done so, will produce a strong heady nourishing well-tasted and fine Liquor, which is now more practised then ever. CHAP. III. _To know good from bad_ Malts. This is a Matter of great Importance to all Brewers, both publick and private, for 'tis common for the Seller to cry all is good, but the Buyer's Case is different; wherefore it is prudential to endeavour to be Master of this Knowledge, but I have heard a great Malster that lived towards _Ware_, say, he knew a grand Brewer, that wetted near two hundred Quarters a Week, was not a judge of good and bad Malts, without which 'tis impossible to draw a true length of Ale or Beer. To do this I know but of few Ways, _First_, By the Bite; Is to break the Malt Corn across between the Teeth, in the middle of it or at both Ends, and if it tasteth mellow and sweet, has a round body, breaks soft, is full of flower all its length, smells well and has a thin skin, then it is good; _Secondly_, By Water; Is to take a Glass near full, and put in some Malt; and if it swims, it is right, but if any sinks to the bottom, then it is not true Malt, but steely and retains somewhat of its Barley nature; yet I must own this is not an infallible Rule, because if a Corn of Malt is crack'd, split or broke, it will then take the water and sink, but there may an allowance be given for such incidents, and still room enough to make a judgment. _Thirdly_, Malt that is truly made will not be hard and steely, but of so mellow a Nature, that if forced against a dry Board, will mark and cast a white Colour almost like Chalk. _Fourthly_, Malt that is not rightly made will be part of it of a hard Barley nature, and weigh heavier than that which is true Malt. CHAP. IV. _Of the Nature and Use of Pale, Amber and Brown_ Malts. The pale Malt is the slowest and slackest dryed of any, and where it has had a leisure fire, a sufficient time allowed it on the Kiln, and a due care taken of it; the flower of the grain will remain in its full quantity, and thereby produce a greater length of wort, than the brown high dryed Malt, for which reason it is sold for one or two shillings _per_ Quarter more than that: This pale Malt is also the most nutritious sort to the body of all others, as being in this state the most simple and nearest to its Original Barley-corn, that will retain an Alcalous and Balsamick quality much longer than the brown sort; the tender drying of this Malt bringing its body into so soft a texture of Parts, that most of the great Brewers, brew it with Spring and Well-waters, whose hard and binding Properties they think agrees best with this loose-bodied Malt, either in Ales or Beer's and which will also dispense with hotter waters in brewing of it, than the brown Malt can. The amber-colour'd Malt is that which is dryed in a medium degree, between the pale and the brown, and is very much in use, as being free of either extream. Its colour is pleasant, its taste agreeable and its nature wholsome, which makes it be prefer'd by many as the best of Malts; this by some is brewed either with hard or soft waters, or a mixture of both. The brown Malt is the soonest and highest dryed of any, even till it is so hard, that it's difficult to bite some of its Corns asunder, and is often so crusted or burnt, that the farinous part loses a great deal of its essential Salts and vital Property, which frequently deceives its ignorant Brewer, that hopes to draw as much Drink from a quarter of this, as he does from pale or amber sorts: This Malt by some is thought to occasion the Gravel and Stone, besides what is commonly called the Heart-burn; and is by its steely nature less nourishing than the pale or amber Malts, being very much impregnated with the fiery fumiferous Particles of the Kiln, and therefore its Drink sooner becomes sharp and acid than that made from the pale or amber sorts, if they are all fairly brewed: For this reason the _London_ Brewers mostly use the _Thames_ or _New River_ waters to brew this Malt with, for the sake of its soft nature, whereby it agrees with the harsh qualities of it better than any of the well or other hard Sorts, and makes a luscious Ale for a little while, and a But-beer that will keep very well five or six Months, but after that time it generally grows stale, notwithstanding there be ten or twelve Bushels allowed to the Hogshead, and it be hopp'd accordingly. Pale and amber Malts dryed with Coak or Culm, obtains a more clean bright pale Colour than if dryed with any other Fuel, because there is not smoak to darken and sully their Skins or Husks, and give them an ill relish, that those Malts little or more have, which are dryed with Straw, Wood, or Fern, &c. The Coak or _Welch_ Coal also makes more true and compleat Malt, as I have before hinted, than any other Fuel, because its fire gives both a gentle and certain Heat, whereby the Corns are in all their Parts gradually dryed, and therefore of late these Malts have gained such a Reputation that great quantities have been consumed in most Parts of the Nation for their wholsome Natures and sweet fine Taste: These make such fine Ales and But-beers, as has tempted several of our Malsters in my Neighbour-hood to burn Coak or Culm at a great expence of Carriage thirty Miles from _London_. Next to the Coak-dryed Malt, the Straw-dryed is the sweetest and best tasted: This I must own is sometimes well Malted where the Barley, Wheat, Straw, Conveniencies and the Maker's Skill are good; but as the fire of the Straw is not so regular as the Coak, the Malt is attended with more uncertainty in its making, because it is difficult to keep it to a moderate and equal Heat, and also exposes the Malt in some degree to the taste of the smoak. Brown Malts are dryed with Straw, Wood and Fern, &c. the Straw-dryed is not the best, but the Wood sort has a most unnatural Taste, that few can bear with, but the necessitous, and those that are accustomed to its strong smoaky tang; yet is it much used in some of the Western Parts of _England_, and many thousand Quarters of this Malt has been formerly used in _London_ for brewing the Butt-keeping-beers with, and that because it sold for two Shillings _per_ Quarter cheaper than the Straw-dryed Malt, nor was this Quality of the Wood-dryed Malt much regarded by some of its Brewers, for that its ill Taste is lost in nine or twelve Months, by the Age of the Beer, and the strength of the great Quantity of Hops that were used in its Preservation. The Fern-dryed Malt is also attended with a rank disagreeable Taste from the smoak of this Vegetable, with which many Quarters of Malt are dryed, as appears by the great Quantities annually cut by Malsters on our Commons, for the two prevalent Reasons of cheapness and plenty. At _Bridport_ in _Dorsetshire_, I knew an Inn-keeper use half Pale and half Brown Malt for Brewing his Butt-beers, that, proved to my Palate the best I ever drank on the Road, which I think may be accounted for, in that the Pale being the slackest, and the Brown the hardest dryed, must produce a mellow good Drink by the help of a requisite Age, that will reduce those extreams to a proper Quality. CHAP. V. _Of the Nature of several Waters and their use in Brewing. And first of Well-waters_. Water next to Malt is what by course comes here under Consideration as a Matter of great Importance in Brewing of wholsome fine Malt-liquors, and is of such Consequence that it concerns every one to know the nature of the water he Brews with, because it is the Vehicle by which the nutritious and pleasant Particles of the Malt and Hop are conveyed into our Bodies, and there becomes a diluter of our Food: Now the more simple and freer every water is from foreign Particles, the better it will answer those Ends and Purposes; for, as Dr_.Mead_ observes, some waters are so loaded with stony Corpuscles, that even the Pipes thro' which they are carried, in time are incrusted and stopt up by them, and is of that petrifying nature as to breed the Stone in the Bladder, which many of the _Parisians_ have been instances of, by using this sort of water out of the River _Seine_. And of this Nature is another at _Rowel_ in _Northamptonshire_, which in no great distance of time so clogs the Wheel of an overshot Mill there, that they are forced with, convenient Instruments to cut way for its Motion; and what makes it still more evident, is the sight of those incrusted Sides of the Tea-kettles, that the hard Well-waters are the occasion of, by being often boiled in them: And it is further related by the same Doctor, that a Gentlewoman afflicted with frequent returns of violent Colick Pains was cured by the Advice of _Van Helmont_, only by leaving off drinking Beer brewed with Well-water; It's true, such a fluid has a greater force and aptness to extract the tincture out of Malt, than is to be had in the more innocent and soft Liquor of Rivers: But for this very reason it ought not, unless upon meer necessity, to be made use of; this Quality being owing to the mineral Particles and alluminous Salts with which it is impregnated. For these waters thus saturated, will by their various gravities in circulation, deposit themselves in one part of the animal Body or other, which has made some prove the goodness of Water by the lightness of its body in the Water Scales, now sold in several of the _London_ Shops, in order to avoid the Scorbutick, Colicky, Hypochondriack, and other ill Effects of the Clayey and other gross Particles of stagnating Well-waters, and the calculous Concretions of others; and therefore such waters ought to be mistrusted more than any, where they are not pure clear and soft or that don't arise from good Chalks or stony Rocks, that are generally allowed to afford the best of all the Well sorts. Spring-waters are in general liable to partake of those minerals thro' which they pass, and are salubrious or mischievous accordingly. At _Uppingham_ in _Rutland_, their water is said to come off an Allum-rock, and so tints their Beer with its saline Quality, that it is easily tasted at the first Draught. And at _Dean_ in _Northamptonshire_, I have seen the very Stones colour the rusty Iron by the constant running of a Spring-water; but that which will Lather with Soap, or such soft water that percolates through Chalk, or a Grey Fire-stone, is generally accounted best, for Chalks in this respect excell all other Earths, in that it administers nothing unwholsome to the perfluent waters, but undoubtedly absorps by its drying spungy Quality any ill minerals that may accompany the water that runs thro' them. For which reason they throw in, great Quantities of Chalk into their Wells at _Ailsbury_ to soften their water, which coming off a black Sand-stone, is so hard and sharp that it will often turn their Beer sour in a Week's time, so that in its Original State it's neither fit to Wash nor Brew with, but so long as the Alcalous soft Particles of the Chalk holds good, they put it to both uses. River-waters are less liable to be loaded with metallick, petrifying, saline and other insanous Particles of the Earth, than the Well or Spring sorts are, especially at some distance from the Spring-head, because the Rain water mixes with and softens it, and are also much cured by the Sun's heat and the Air's power, for which reason I have known several so strict, that they won't let their Horses drink near the first rise of some of them; this I have seen the sad Effects of, and which has obliged me to avoid two that run cross a Road in _Bucks_ and _Hertfordshire_: But in their runnings they often collect gross Particles from ouzy muddy mixtures, particularly near Town, that make the Beer subject to new fermentations, and grow foul upon alteration of weather as the _Thames_ water generlly does; yet is this for its softness much better than the hard sort, however both these waters are used by some Brewers as I shall hereafter observe; but where a River-water can be had clear in a dry time, when no great Rain has lately fell out of Rivulets or Rivers that have a Gravelly, Chalky, Sandy or Stone-bottom free from the Disturbance of Cattle, &c. and in good Air, as that of _Barkhamstead St. Peters_ in _Hertfordshire_ is; it may then justly claim the name of a most excellent water for Brewing, and will make a stronger Drink with the same quantity of Malt than any of the Well-waters; insomuch that that of the _Thames_ has been proved to make as strong Beer with seven Bushels of Malt, as Well-water with eight; and so are all River-waters in a proportionable degree, and where they can be obtain'd clean and pure, Drink may be drawn fine in a few Days after Tunning. Rain-water is very soft, of a most simple and pure nature, and the best Diluter of any, especially if received free from Dirt, and the Salt of Mortar that often mixes with it as it runs off tyled Roofs; this is very agreeable for brewing of Ales that are not to be kept a great while, but for Beers that are to remain some time in the Casks, it is not so, well, as being apt to putrify the soonest of any. Pond-waters; this includes all standing waters chiefly from Rain, and are good or bad as they happen; for where there is a clean bottom, and the water lies undisturbed from the tread of Cattle, or too many Fish, in an open sound Air, in a large quantity, and where the Sun has free access; it then comes near, if not quite as good as Rain or River-waters, as is that of _Blew-pot_ Pond on the high Green at _Gaddesden_ in _Hertfordshire_ and many others, which are often prefer'd for Brewing, even beyond many of the soft Well-waters about them. But where it is in a small quantity, or full of Fish (especially the sling Tench) or is so disturbed by Cattle as to force up Mud and Filth; it is then the most foul and disagreeable of all others: So is it likewise in long dry Seasons when our Pond-waters are so low as obliges us to strain it thro' Sieves before we can use it, to take out the small red Worms and other Corruptions, that our stagnant waters are generally then too full of. The latest and best Doctors have so far scrutinized into the prime Cause of our _British_ malady the Scurvy, as to affirm its first rise is from our unwholesome stagnating waters, and especially those that come off a clayey surface, as there are about _Londonderry_ and _Amsterdam_, for that where the waters are worst, there this Distemper is most common, so that in their Writings they have put it out of all doubt, that most of our complicated symptoms that are rank'd under this general Name, if they don't take their beginning from such water, do own it to be their chief Cause. CHAP. VI. _Of Grinding_ Malts. As trifling as this Article in Brewing may seem at first it very worthily deserves the notice of all concern'd therein, for on this depends much the good of our Drink, because if it is ground too small the flower of the Malt will be the easier and more freely mix with the water, and then will cause the wort to run thick, and therefore the Malt must be only just broke in the Mill, to make it emit its Spirit gradually, and incorporate its flower with the water in such a manner that first a stout Beer, then an Ale, and afterwards a small Beer may be had at one and the same Brewing, and the wort run off fine and clear to the last. Many are likewise so sagacious as to grind their brown Malt a Fortnight before they use it, and keep it in a dry Place from the influence of too moist an Air, that it may become mellower by losing in a great measure the fury of its harsh fiery Particles, and its steely nature, which this sort of Malt acquires on the Kiln; however this as well as many other hard Bodies may be reduced by Time and Air into a more soluble, mellow and soft Condition, and then it will imbibe the water and give a natural kind tincture more freely, by which a greater quantity and stronger Drink may be made, than if it was used directly from the Mill, and be much smoother and better tasted. But the pale Malt will be fit for use at a Week's end, because the leisureness of their drying endows them with a softness from the time they are taken off the Kiln to the time they are brewed, and supplies in them what Time and Air must do in the brown sorts. This method of grinding Malt so long before-hand can't be so conveniently practised by some of the great Brewers, because several of them Brew two or three times a Week, but now most of them out of good Husbandry grind their Malts into the Tun by the help of a long descending wooden Spout, and here they save the Charge of emptying or uncasing it out of the Bin (which formerly they used to do before this new way was discovered) and also the waste of a great deal of the Malt-flower that was lost when carryed in Baskets, whereas now the Cover of the Tun presents all that Damage In my common Brewhouse at _London_ I ground my Malt between two large Stones by the Horse-mill that with one Horse would grind [blank space] quarters an Hour, But in the Country I use a steel Hand-mill, that Cost at first forty Shillings; which will by the help of only one Man grind six or eight Bushels in an Hour, and will last a Family many Years without hardning or cutting: There are some old-fashion'd stone Hand-mills in being, that some are Votaries for and prefer to the Iron ones, because they alledge that these break the Corn's body, when the Iron ones only cut it in two, which occasions the Malt so broke by the Stones, to give the water a more easy, free and regular Power to extract its Virtue, than the Cut-malt can that is more confin'd within its Hull. Notwithstanding the Iron ones are now mostly in Use for their great Dispatch and long Duration. In the Country it is frequently done by some to throw a Sack of Malt on a Stone or Brick-floor as soon as it is ground, and there let it lye, giving it one turn, for a Day or two, that the Stones or Bricks may draw out the fiery Quality it received from the Kiln, and give the Drink a soft mild Taste. CHAP. VII. _Of Brewing in general_. Brewing, like several other Arts is prostituted to the opinionated Ignorance of many conceited Pretenders, who if they have but seen or been concern'd in but one Brewing, and that only one Bushel of Malt, assume the Name of a Brewer and dare venture on several afterwards, as believing it no other Task, than more Labour, to Brew a great deal as well as a little; from hence it partly is, that we meet with such hodge-podge Ales and Beers, as are not only disagreeable in Taste and Foulness, but indeed unwholsome to the Body of Man, for as it is often drank thick and voided thin, the Feces or gross part must in my Opinion remain behind in some degree. Now what the Effects of that may be, I must own I am not Physician enough to explain, but shrewdly suspect it may be the Cause of Stones, Colicks, Obstructions, and several other Chronical Distempers; for if we consider that the sediments of Malt-liquors are the refuse of a corrupted Grain, loaded with the igneous acid Particles of the Malt, and then again with the corrosive sharp Particles of the Yeast, it must consequently be very pernicious to the _British_ human Body especially, which certainly suffers much from the animal Salts of the great Quantities of Flesh that we Eat more than People of any other Nation whatsoever; and therefore are more then ordinarily obligated not to add the scorbutick mucilaginous Qualities of such gross unwholsome Particles, that every one makes a lodgment of in their Bodies, as the Liquors they drink are more or less thick; for in plain Truth, no Malt-liquor can be good without it's fine. The late Curious _Simon Harcourt_ Esq; of _Penly_, whom I have had the honour to drink some of his famous _October_ with, thought the true Art of Brewing of such Importance, that it is said to Cost him near twenty Pounds to have an old Days-man taught it by a _Welch_ Brewer, and sure it was this very Man exceeded all others in these Parts afterwards in the Brewing of that which he called his _October_ Beer. So likewise in _London_ they lay such stress on this Art, that many have thought it worth their while to give one or two hundred Guineas with an Apprentice: This Consideration also made an Ambassador give an extraordinary Encouragement to one of my Acquaintance to go over with him, that was a great Master of this Science. But notwithstanding all that can be said that relates to this Subject, there are so many Incidents attending Malt-liquors, that it has puzled several expert Men to account for their difference, though brewed by the same Brewer, with the same Malt, Hops and Water, and in the same Month and Town, and tapp'd at the same time: The Beer of one being fine, strong and well Tasted, while the others have not had any worth drinking, now this may be owing to the different Weather in the same Month, that might cause an Alteration in the working of the Liquors, or that the Cellar may not be so convenient, or that the Water was more disturbed by Winds or Rains, &c. But it has been observed that where a Gentleman has imployed one Brewer constantly, and uses the same sort of Ingredients, and the Beer kept in dry Vaults or Cellars that have two or three Doors; the Drink has been generally good. And where such Malt-liquors are kept in Butts, more time is required to ripen, meliorate and fine them, than those kept in Hogsheads, because the greater quantity must have the longer time; so also a greater quantity will preserve itself better than a lesser one, and on this account the Butt and Hogshead are the two best sized Casks of all others; but all under a Hogshead hold rather too small a quantity to keep their Bodies. The Butt is certainly a most noble Cask for this use, as being generally set upright, whereby it maintains a large Cover of Yeast, that greatly contributes to the keeping in the Spirits of the Beer, admits of a most convenient broaching in the middle and its lower part, and by its broad level Bottom, gives a better lodgment to the fining and preserving Ingredients, than any other Cask whatsoever that lyes in, the long Cross-form. Hence it partly is, that the common Butt-beer is at this time in greater Reputation than ever in _London_, and the Home-brew'd Drinks out of Credit; because the first is better cured in its Brewing, in its Quantity, in its Cask, and in its Age; when the latter has been loaded with the pernicious Particles of great Quantities of Yeast, of a short Age, and kept in small Casks, that confines its Owner, only to Winter Brewing and Sale, as not being capable of sustaining the Heat of the Weather, for that the acidity of the Yeast brings on a sudden hardness and staleness of the Ale, which to preserve in its mild Aley Taste, will not admit of any great Quantity of Hops; and this is partly the reason that the handful of Salt which the _Plymouth_ Brewers put into their Hogshead, hinders their Ale from keeping, as I shall hereafter take notice of. CHAP. VIII. _The_ London _Method of Brewing_. In a great Brewhouse that I was concern'd in, they wetted or used a considerable Quantity of Malt in one Week in Brewing Stout-beer, common Butt-beer, Ale and small Beer, for which purpose they have River and Well Waters, which they take in several degrees of Heat, as the Malt, Goods and Grain are in a condition to receive them, and according to the Practice there I shall relate the following Particulars, viz. _For Stout Butt Beer_. This is the strongest Butt-Beer that is Brewed from brown Malt, and often sold for forty Shillings the Barrel, or six Pound the Butt out of the wholesale Cellars: The Liquor (for it is Sixpence forfeit in the _London_ Brewhouse if the word Water is named) in the Copper designed for the first Mash, has a two Bushel Basket, or more, of the most hully Malt throw'd over it, to cover its Top and forward its Boiling; this must be made very hot, almost ready to boil, yet not so as to blister, for then it will be in too high a Heat; but as an indication of this, the foul part of the Liquor will ascend, and the Malt swell up, and then it must be parted, look'd into and felt with the Finger or back of the Hand, and if the Liquor is clear and can but be just endured, it is then enough, and the Stoker must damp his fire as soon as possible by throwing in a good Parcel of fresh Coals, and shutting his Iron vent Doors, if there are any; immediately on this they let as much cold Liquor or Water run into the Copper as will make it all of a Heat, somewhat more than Blood-warm, this they Pump over, or let it pass by a Cock into an upright wooden square Spout or Trunk, and it directly rises thro' the Holes of a false Bottom into the Malt, which is work'd by several Men with Oars for about half an Hour, and is called the first and stiff Mash: While this is doing, there is more Liquor heating in the Copper that must not be let into the mash Tun till it is very sharp, almost ready to boil, with this they Mash again, then cover it with several Baskets of Malt, and let it stand an Hour before it runs into the Under-back, which when boiled an Hour and a half with a good quantity of Hops makes this Stout. The next is Mash'd with a cooler Liquor, then a sharper, and the next Blood-warm or quite Cold; by which alternate degrees of Heat, a Quantity of small Beer is made after the Stout. _For Brewing strong brown Ale called_ Stitch. This is most of it the first running of the Malt, but yet of a longer Length than is drawn for the Stout; It has but few Hops boiled in it, and is sold for Eight-pence _per_ Gallon at the Brewhouse out of the Tun, and is generally made to amend the common brown Ale with, on particular Occasions. This Ale I remember was made use of by [Blank space] _Medlicot_ Esq; in the beginning of a Consumption, and I heard him say, it did him very great Service, for he lived many Years afterwards. _For Brewing common brown Ale and Starting Beer_. They take the Liquors from the brown Ale as for the Stout, but draw a greater Quantity from the Malt, than for Stout or Stitch, and after the fifth and second Mash they Cap the Goods with fresh Malt to keep in the Spirit and Boil it an Hour; after this, small Beer is made of the same Goods. Thus also the common brown Starting Butt-Beer is Brewed, only boiled with more Hops an Hour and a half, and work'd cooler and longer than the brown Ale, and a shorter Length drawn from the Malt. But it is often practised after the brown Ale, and where a Quantity of small Beer is wanted, or that it is to be Brewed better than ordinary, to put so much fresh Malt on the Goods as will answer that purpose. _For Brewing Pale and Amber Ales and Beers_. As the brown Malts are Brewed with River, these are Brewed with Well or Spring Liquors. The Liquors are by some taken sharper for pale than brown Malts, and after the first scalding Liquor is put over, some lower the rest by degrees to the last which is quite Cold, for their small Beer; so also for Butt-Beers there is no other difference than the addition of more Hops, and boiling, and the method of working. But the reasons for Brewing pale Malts with Spring or hard Well waters, I have mentioned in my second Book of Brewing. _For Brewing Entire Guile Small Beer_. On the first Liquor they throw some hully Malt to shew the break of it, and when it is very sharp, they let in some cold Liquor, and run it into the Tun milk warm; this is mash'd with thirty or forty pulls of the Oar, and let stand till the second Liquor is ready, which must be almost scalding hot to the back of the Hand, then run it by the Cock into the Tun, mash it up and let it stand an Hour before it is spended off into the Under-back: These two pieces of Liquor will make one Copper of the first wort, without putting any fresh Malt on the Goods; the next Liquor to be Blood-warm, the next sharp, and the next cool or cold; for the general way in great Brewhouses is to let a cool Liquor precede a sharp one, because it gradually opens the Pores of the Malt and Goods, and prepares the way for the hotter Liquor that is to follow. _The several Lengths or Quantities of Drinks that have been made from Malt, and their several Prices, as they have been sold at a common Brewhouse_. For Stout-Beer, is commonly drawn one Barrel off a quarter of Malt, and sold for thirty Shillings _per_ Barrel from the Tun. For Stitch or strong brown Ale, one Barrel and a Firkin, at one and twenty Shillings and Fourpence _per_ Barrel from the Tun. For common brown Ale, one Barrel and a half or more, at sixteen Shillings _per_ Barrel, that holds thirty two Gallons, from the Tun. For Intire small Beer, five or six Barrels off a Quarter, at seven or eight Shillings _per_ Barrel from the Tun. For Pale and Amber Ale, one Barrel and a Firkin, at one Shilling _per_ Gallon from the Tun. CHAP. IX. _The Country or private way of Brewing_. Several Countries have their several Methods of Brewing, as is practised in _Wales, Dorchester, Nottingham, Dundle_, and many other Places; but evading Particulars, I shall here recommend that which I think is most serviceable both in Country and _London_ private Families. And first, I shall observe that the great Brewer has some advantages in Brewing more than the small one, and yet the latter has some Conveniences which the former can't enjoy; for 'tis certain that the great Brewer can make more Drink, and draw a greater Length in proportion to his Malt, than a Person can from a lesser Quantity, because the greater the Body, the more is its united Power in receiving and discharging, and he can Brew with less charge and trouble by means of his more convenient Utensils. But then the private Brewer is not without his Benefits; for he can have his Malt ground at pleasure, his Tubs and moveable Coolers sweeter and better clean'd than the great fixed Tuns and Backs, he can skim off his top Yeast and leave his bottom Lees behind, which is what the great Brewer can't so well do; he can at discretion make additions of cold wort to his too forward Ales and Beers, which the great Brewer can't so conveniently do; he can Brew how and when he pleases, which the great ones are in some measure hindred from. But to come nearer the matter, I will suppose a private Family to Brew five Bushels of Malt, whose Copper holds brim-full thirty six Gallons or a Barrel: On this water we put half a Peck of Bran or Malt when it is something hot, which will much forward it by keep in the Steams or Spirit of the water, and when it begins to Boil, if the water is foul, skim off the Bran or Malt and give it the Hogs, or else lade both water and that into the mash Vat, where it is to remain till the steam is near spent, and you can see your Face in it, which will be in about a quarter of an Hour in cold weather; then let all but half a Bushel of the Malt run very leisurely into it, stirring it all the while with an Oar or Paddle, that it may not Ball, and when the Malt is all but just mix'd with water it is enough, which I am sensible is different from the old way and the general present Practice; but I shall here clear that Point. For by not stirring or mashing the Malt into a Pudding Consistence or thin Mash, the Body of it lies in a more loose Condition, that will easier and sooner admit of a quicker and more true Passage of the after-ladings of the several Bowls or Jets of hot water, which must run thorough it before the Brewing is ended; by which free percolation the water has ready access to all the parts of the broken Malt, so that the Brewer is capacitated to Brew quicker or slower, and to make more Ale or small Beer; If more Ale, then hot Boiling water must be laded over to slow that one Bowl must run almost off before another is put over, which will occasion the whole Brewing to last about sixteen Hours, especially if the _Dundle_ way is followed, of spending it out of the Tap as small as a Straw, and as fine as Sack, and then it will be quickly so in the Barrel: Of if less or weaker Ale is to be made and good small Beer, then the second Copper of boiling water may be put over expeditiously and drawn out with a large and fast steam. After the first stirring of the Malt is done, then put over the reserve of half a Bushel of fresh Malt to the four Bushels and half that is already in the Tub, which must be spread all over it, and also cover the top of the Tub with some Sacks or other Cloths to keep in the Steam or Spirit of the Malt; then let it stand two or three Hours, at the end of which, put over now and then a Bowl of the boiling water in the Copper as is before directed, and so continue to do till as much is run off as will almost fill the Copper; then in a Canvas or other loose woven Cloth, put in half a Pound of Hops and boil them half an Hour, when they must be taken out, and as many fresh ones put in their room as is judged proper to boil half an Hour more, if for Ale: But if for keeping Beer, half a Pound of fresh ones should be put in at every half Hour's end, and Boil an Hour and a half briskly: Now while the first Copper of wort is Boiling, there should be scalding water leisurely put over the Goods, Bowl by Bowl, and run off, that the Copper may be filled again immediately after the first is out, and boiled an Hour with near the same quantity of fresh Hops, and in the same manner as those in the first Copper of Ale-wort were. The rest for small Beer may be all cold water put over the Grains at once, or at twice, and Boil'd an Hour each Copper with the Hops that has been boil'd before. But here I must observe, that sometimes I have not an opportunity to get hot water for making all my second Copper of wort, which obliges me then to make use of cold to supply what was wanting. Out of five Bushels of Malt, I generally make a Hogshead of Ale with the two first Coppers of wort, and a Hogshead of small Beer with the other two, but this more or less according to please me, always taking Care to let each Copper of wort be strained off thro' a Sieve, and cool in four or five Tubs to prevent its foxing. Thus I have brewed many Hogsheads of midling Ale that when the Malt is good, has proved strong enough for myself and satisfactory to my friends: But for strong keeping Beer, the first Copper of wort may be wholly put to that use, and all the rest small Beer: Or when the first Copper of wort is intirely made use of for strong Beer, the Goods may be help'd with more fresh Malt (according to the _London_ Fashion) and water lukewarm put over at first with the Bowl, but soon after sharp or boiling water, which may make a Copper of good Ale, and small Beer after that. In some Parts of the North, they take one or more Cinders red hot and throw some Salt on them to overcome the Sulphur of the Coal, and then directly thrust it into the fresh Malt or Goods, where it lies till all the water is laded over and the Brewing done, for there is only one or two mashings or stirrings at most necessary in a Brewing: Others that Brew with Wood will quench one or more Brands ends of Ash in a Copper of wort, to mellow the Drink as a burnt Toast of Bread does a Pot of Beer; but it is to be observed, that this must not be done with Oak, Firr, or any other strong-scented Wood; lest it does more harm than good. _Another Way_. When small Beer is not wanted, and another Brewing is soon to succeed the former, then may the last small Beer wort, that has had no Hops boiled in it, remain in the Copper all Night, which will prevent its foxing, and be ready to boil instead of so much water to put over the next fresh Malt: This will greatly contribute to the strengthening, bettering and colouring of the next wort, and is commonly used in this manner when Stout or _October_ Beer is to be made, not that it is less serviceable if it was for Ale, or Intire Guile small Beer; but lest it should taste of the Copper by remaining all Night in it, it may be dispersed into Tubs and kept a Week or more together if some fresh cold water is daily added to it, and may be brewed as I have mentioned, taking particular Care in this as well as in the former ways to return two, three, or more Hand-bowls of wort into the Mash Tub, that first of all runs off, till it comes absolutely fine and clear, and then it may spend away or run off for good: Others will reserve this small Beer wort unboiled in Tubs, and keep it there a Week in Winter, or two or three Days in Summer, according to Conveniency, by putting fresh water every Day to it, and use it instead of water for the first Mash, alledging it is better so than boiled, because by that it is thickened and will cause the wort to run foul; this may be a Benefit to a Victualler that Brews to Sell again, and can't Vent his small Beer; because for such small raw wort that is mix'd with any water, there is no Excise to be pay'd. _For Brewing Intire Guile Small Beer_. There can be no way better for making good small Beer, than by Brewing it from fresh Malt, because in Malt as well as in Hops, and so in all other Vegetables, there is a Spirituous and Earthy part, as I shall further enlarge on in writing of the Hop; therefore all Drink brewed from Goods or Grains after the first or second worts are run off, is not so good and wholsome, as that intirely brewed from fresh Malt, nor could any thing but Necessity cause me to make use of such Liquor; yet how many thousands are there in this Nation that know nothing of the matter, tho' it is of no small Importance, and ought to be regarded by all those that value their Health and Taste. And here I advertise every one who reads or hears this, and is capable of being his own Friend, so far to mind this _Item_ and prefer that small Beer which is made entirely from fresh Malt, before any other that is brewed after strong Beer or Ale. Now to brew such Guile small Beer after the boiling water has stood in the Tub till it is clear, put in the Malt leisurely, and mash it that it does not Ball or Clot, then throw over some fresh Malt on the Top, and Cloths over that, and let it stand two Hours before it is drawn off, the next water may be between hot and cold, the next boiling hot, and the next Cold; or if conveniency allows not, there may be once scalding water, and all the rest cold instead of the last three. Thus I brew my Intire Guile small Beer, by putting the first and last worts together, allowing half, or a Pound of Hops to a Hogshead and boiling it one Hour, but if the Hops were shifted twice in that time, the Drink would plainly discover the benefit. Sometimes, when I have been in haste for small Beer, I have put half a Bushel of Malt and a few Hops into my Barrel-Copper, and boil'd a Kettle gallop as some call it an Hour, and made me a present Drink, till I had more leisure to brew better. _A particular way of Brewing strong_ October _Beer_. There was a Man in this Country that brewed for a Gentleman constantly after a Very precise Method, and that was, as soon as he had put over all his first Copper of water and mash'd it some time, he would directly let the Cock run a small stream and presently put some fresh Malt on the former, and mash on the while the Cock was spending, which he would put again over the Malt, as often as his Pail or Hand-bowl was full, and this for an Hour or two together; then he would let it run off intirely, and put it over at once, to run off again as small as a Straw. This was for his _October_ Beer: Then he would put scalding water over the Goods at once, but not mash, and Cap them with more fresh Malt that stood an Hour undisturbed before he would draw it off for Ale; the rest was hot water put over the Goods and mash'd at twice for small Beer: And it was observed that his _October_ Beer was the most famous in the Country, but his Grains good for little, for that he had by this method wash'd out all or most of their goodness; this Man was a long while in Brewing, and once his Beer did not work in the Barrel for a Month in a very hard Frost, yet when the weather broke it recovered and fermented well, and afterwards proved very good Drink, but he seldom work'd, his Beer less than a Week in the Vat, and was never tapp'd under three Years. This way indeed is attended with extraordinary Labour and Time, by the Brewers running off the wort almost continually, and often returning the same again into the mash Vat, but then it certainly gives him an opportunity of extracting and washing out the goodness of the Malt, more than any of the common Methods, by which he is capacitated to make his _October_ or _March_ Beer as strong as he pleases. The Fame of _Penly October_ Beer is at this time well known not only throughout _Hertfordshire_, but several other remote Places, and truly not without desert, for in all my Travels I never met with any that excell'd it, for a clear amber Colour, a fine relish, and a light warm digestion. But what excell'd all was the generosity of its Donor, who for Hospitality in his Viands and this _October_ Beer, has left but few of his Fellows. I remember his usual Expression to be, You are welcome to a good Batch of my _October_, and true it was, that he proved his Words by his Deeds, for not only the rich but even the poor Man's Heart was generally made glad, even in advance, whenever they had Business at _Penly_, as expecting a refreshment of this Cordial Malt Liquor, that often was accompany'd with a good Breakfast or Dinner besides, while several others that had greater Estates would seem generous by giving a Yeoman Man Neighbour, the Mathematical Treat of a look on the Spit, and a standing Drink at the Tap. _Of Brewing Molosses Beer_. Molosses or Treacle has certainly been formerly made too much use of in the brewing of Stout Beer, common Butt Beers, brown Ales and small Beer when Malts have been dear: But it is now prohibited under the Penalty of fifty Pounds for every ten Pounds weight found in any common Brewhouse, and as Malts are now about twenty Shillings _per_ Quarter, and like to be so by the Blessing of God, and the Assistance of that invaluable excellent Liquor for steeping Seed Barley in, published in a late Book intituled, _Chiltern and Vale Farming Explained_: There is no great danger of that, Imposition being rife again, which in my Opinion was very unwholsome, because the Brewer was obliged to put such a large quantity of Treacle into his water or small wort to make it strong Beer or Ale, as very probably raised a sweating in some degree in the Body of the drinker: Tho' in small Beer a lesser quantity will serve; and therefore I have known some to brew it in that for their Health's sake, because this does not breed the Scurvy like Malt-liquors, and at the same time will keep open the Pipes and Passages of the Lungs and Stomach, for which purpose they put in nine Pounds weight into a Barrel-Copper of cold water, first mixing it well, and boiling it briskly with a quarter of a Pound of Hops or more one Hour, so that it may come off twenty seven Gallons. _A Method practiced by a Victualler for Brewing of Ale or_ October _Beer from_ Nottingham. His Copper holds twenty four Gallons, and the Mash Tub has room enough for four and more Bushels of Malt. The first full Copper of boiling water he puts into the Mash Tub, there to lye a quarter of an Hour, till the steam is so far spent, that he can see his Face in it, or as soon as the hot water is put in, throws a Pail or two of cold water into it, which will bring it at once into a temper; then he lets three Bushels of Malt be run leisurely into it, and stirred or mash'd all the while, but as little as can be, or no more than just to keep the Malt from clotting or balling; when that is done, he puts one Bushel of dry Malt on the Top to keep in the Vapour or Spirit, and so lets it stand covered two Hours, or till the next Copper full of water is boiled hot, which he lades over the Malt or Goods three Hand-bowls full at a time, that are to run off at the Cock or Tap by a very small stream before more is put on, which again must be returned into the Mash Tub till it comes off exceeding fine, for unless the wort is clear when it goes into the Copper, there are little hopes it will be so in the Barrel, which leisure way obliges him to be sixteen Hours in brewing these four Bushels of Malt. Now between the ladings over he puts cold water into the Copper to be boiling hot, while the other is running off; by this means his Copper is kept up near full, and the Cock spending to the end of brewing his Ale or small Beer, of which only twenty one Gallons must be saved of the first wort that is reserved in a Tub, wherein four Ounces of Hops are put and then it is to be set by. For the second wort I will suppose there are twenty Gallons of water in the Copper boiling hot, that must be all laded over in the same manner as the former was, but no cold water need here be mixed; when half of this is run out into a Tub, it must be directly put into the Copper with half of the first wort, strain'd thro' the Brewing Sieve as it lies on a small loose wooden Frame over the Copper, to keep back those Hops that were first put in to preserve it, which is to make the first Copper twenty one Gallons; then upon its beginning to boil he puts in a Pound of Hops in one or two Canvas or other coarse Linnen Bags, somewhat larger than will just contain the Hops, that an allowance may be given for their swell; this he boils away very briskly for half an Hour, when he takes the Hops out and continues boiling the wort by itself till it breaks into Particles a little ragged, and then it is enough and must be dispers'd into the cooling Tubs very thin: Then put the remainder of the first and second wort together and boil that, the same time, in the same manner, and with the same quantity of fresh Hops the first was. The rest of the third or small Beer wort will be about fifteen or twenty Gallons more or less, he mixes directly with some cold water to keep it free of Excise, and puts it into the Copper as the first Liquor to begin a second Brewing of Ale with another four Bushels of Malt as he did before, and so on for several Days together if necessary; but at last there may be some small Beer made, tho' some will make make none, because the Goods or Grains will go the further in feeding of Hogs. _Observations on the foregoing Method_. The first Copper of twenty four Gallons of water is but sufficient to wet three Bushels of Malt, and by the additions of cold water as the hot is expended, it matters not how much the Malt drinks up: Tho' a third part of water is generally allowed for that purpose that is never returned. By the leisure putting over the Bowls of water, the goodness of the Malt is the more extracted and washed out, so that more Ale may be this way made and less small Beer, than if the wort was drawed out hastily; besides the wort has a greater opportunity of coming off finer by a slow stream than by a quicker one, which makes this Method excel all others that discharge the wort out of the Mash Tub more hastily. Also by the continual running of the Cock or Tap, the Goods or Grains are out of danger of sowring, which often happens in Summer Brewings, especially when the Cook is stopt between the several boilings of the wort, and what has been the very Cause of damaging or spoiling many Guiles of Drink. This Brewer reposes such a Confidence in the Hops to preserve the wort from fixing even in the very hottest time in Summer, that he puts all his first running into one Tub, till he has an opportunity of boiling it, and when Tubs and Room are so scarce that the wort is obliged to be laid thick to cool, then the security of some fresh Hops (and not them already boiled or soak'd) may be put into it, which may be got out again by letting the Drink run thro' the Cullender, and after that a Hair Sieve to keep the Seeds of the Hop back as the Drink goes into the Barrel: But this way of putting Hops into the cooling Tubs is only meant where there is a perfect Necessity, and Tubs and Room enough can't be had to lay the wort thin. By this Method of Brewing, Ale may be made as strong or as small as is thought fit, and so may the small Beer that comes after, and is so agreeable that this Brewer makes his Ale and strong keeping _October_ Beer, all one and the same way, only with this Difference, that the latter is stronger and more hopp'd than the former. Where little or no small Beer is wanted, there may little or none be Brewed, according to this manner of Working, which is no small Conveniency to a little Family that uses more strong than small, nor is there any Loss by leaving the Grainy in some Heart, where Horse, Cows, Hogs, or Rabbits are kept. I am very sensible that the Vulgar Error for many Years, has been a standard Sign to the ignorant of boiling strong Worts only till they break or curdle in the Copper, which sometimes will be in three quarters of an Hour, or in an Hour or more, according to the nature of the Malt and Water; but from these in some measure I dissent, and also from those that boil it two or three Hours, for it is certain the longer worts boil, the thicker they are made, because the watry or thin parts evaporate first away, and the thicker any Drink is boiled, the longer it requires to lye in the Barrel to have its Particles broke, which Age must be then the sole cause of, and therefore I have fixed the time and sign to know when the wort is truly enough, and that in such, a manner that an ordinary Capacity may be a true judge of, which hereafter will prevent prodigious Losses in the waste of strong worts that have often been boiled away to greater Loss than Profit. I have here also made known, I think, the true Method of managing the Hop in the Copper, which has long wanted adjusting, to prevent the great damage that longer boilings of them has been the sole occasion of to the spoiling of most of our malt Drinks brewed in this Nation. CHAP. X. _The Nature and Use of the Hop_. This Vegetable has suffered its degradation, and raised its Reputation on the most of any other. It formerly being thought an unwholsome Ingredient, and till of late a great breeder of the Stone in the Bladder, but now that falacious Notion is obviated by Dr_.Quincy_ and others, who have proved that Malt Drink much tinctured by the Hop, is less prone to do that mischief, than Ale that has fewer boiled in it. Indeed when the Hop in a dear time is adulterated with water, in which Aloes, etc. have been infused, as was practised it is said about eight Years ago to make the old ones recover their bitterness and seem new, then they are to be looked on as unwholsome; but the pure new Hop is surely of a healthful Nature, composed of a spirituous flowery part, and a phlegmatick terrene part, and with the best of the Hops I can either make or mar the Brewing, for if the Hops are boiled in strong or small worts beyond their fine and pure Nature, the Liquor suffers, and will be tang'd with a noxious taste both ungrateful and unwholsome to the Stomach, and if boiled to a very great Excess, they will be apt to cause Reachings and disturb a weak Constitution. It is for these Reasons that I advise the boiling two Parcels of fresh Hops in each Copper of Ale-wort, and if there were three for keeping Beer, it would be so much the better for the taste, health of Body and longer Preservation of the Beer in a sound smooth Condition. And according to this, one of my Neighbours made a Bag like a Pillow-bear of the ordinary sixpenny yard Cloth, and boil'd his Hops in it half an Hour, then he took them out, and put in another Bag of the like quantity of fresh Hops and boiled them half an Hour more, by which means he had an opportunity of boiling both Wort and Hops their due time, sav'd himself the trouble of draining them thro' a Sieve, and secured the Seeds of the Hops at the same time from mixing with the Drink, afterwards he boiled the same Bags in his small Beer till he got the goodness of it out, but observe that the Bags were made bigger than what would just contain the Hops, otherwise it will be difficult to boil out their goodness. It's true, that here is a Charge encreased by the Consumption of a greater quantity of Hops than usual, but then how greatly will they answer the desired end of enjoying fine palated wholsome Drink, that in a cheap time will not amount to much if bought at the best Hand; and if we consider their after-use and benefit in small Beer, there is not any loss at all in their Quantity: But where it can be afforded, the very small Beer would be much improved if fresh Hops were also shifted in the boiling of this as well as the stronger worts, and then it would be neighbourly Charity to give them away to the poorer Person. Hence may appear the Hardship that many are under of being necessitated to drink of those Brewers Malt Liquors, who out of avarice boil their Hops to the last, that they may not lose any of their quintessence: Nay, I have known some of the little Victualling Brewers so stupendiously ignorant, that they have thought they acted the good Husband, when they have squeezed the Hops after they have been boiled to the last in small Beer, to get out all their goodness as they vainly imagin'd, which is so reverse to good management, that in my Opinion they had much better put some sort of Earth into the Drink, and it would prove more pleasant and wholsome. And why the small Beer should be in this manner (as I may justly call it) spoiled for want of the trifling Charge of a few fresh Hops, I am a little surprized at, since is the most general Liquor of Families and therefore as great Care is due to as any in its Brewing, to enjoy it in pure and wholsome Order. After the Wort is cooled and put into the working Vat or Tub, some have thrown fresh Hops into it, and worked them with the Yeast, at the same time reserving a few Gallons of raw Wort to wash the Yeast thro' a Sieve to keep back the Hop. This is a good way when Hops enough have not been sufficiently boiled in the Wort, or to preserve it in the Coolers where it is laid thick, otherwise I think it needless. When Hops have been dear, many have used the Seeds of Wormwood, the they buy in the London Seed Shops instead of them: Others _Daucus_ or wild Carrot Seed, that grows in our common Fields, which many of the poor People in this Country gather and dry in their Houses against their wanting of them: Others that wholsome Herb _Horehound_, which indeed is a fine Bitter and grows on several of our Commons. But before I conclude this Article, I shall take notice of a Country Bite, as I have already done of a _London_ one, and that is, of an Arch Fellow that went about to Brew for People, and took his opportunity to save all the used Hops that were to be thrown away, these he washed clean, then would dry them in the Sun, or by the Fire, and sprinkle the juice of _Horehound_ on them, which would give them such a greenish colour and bitterish taste, that with the help of the Screw-press he would sell them for new Hops. Hops in themselves are known to be a subtil grateful Bitter, whose Particles are Active and Rigid, by which the viscid ramous parts of the Malt are much divided, that makes the Drink easy of Digestion in the Body; they also keep it from running into such Cohesions as would make it ropy, valid and sour, and therefore are not only of great use in boiled, but in raw worts to preserve them sound till they can be put into the Copper, and afterwards in the Tun while the Drink is working, as I have before hinted. Here then I must observe, that the worser earthy part of the Hop is greatly the cause of that rough, harsh unpleasant taste, which accompany both Ales and Beers that have the Hops so long boiled in them as to tincture their worts with their mischievous Effects; for notwithstanding the Malt, be ever so good, the Hops, if boiled too long in them, will be so predominant as to cause a nasty bad taste, and therefore I am in hopes our Malt Liquors in general will be in great Perfection, when Hops are made use of according to my Directions, and also that more Grounds will be planted with this most serviceable Vegetable than ever, that their Dearness may not be a disencouragement to this excellent Practice. For I know an Alehouse-keeper and Brewer, who, to save the expence of Hops that were then two Shillings _per_ Pound, use but a quartern instead of a Pound, the rest he supplied with _Daucus_ Seeds; but to be more particular, in a Mug of this Person's Ale I discovered three several Impositions. _First_, He underboil'd his Wort to save its Consumption: _Secondly_, He boiled this Seed instead of the Hop; and _Thirdly_, He beat the Yeast in for some time to encrease the strength of the Drink; and all these in such a _Legerdemain_ manner as gull'd and infatuated the ignorant Drinker to such a degree as not to suspect the Fraud, and that for these three Reasons: _First_, The underboil'd wort being of a more sweet taste than ordinary, was esteemed the Produce of a great allowance of Malt. _Secondly_, The _Daucus_ Seed encreased their approbation by the fine Peach flavour or relish that it gives the Drink; and _Thirdly_, The Yeast was not so much as thought of, since they enjoyed a strong heady Liquor. These artificial Qualities, and I think I may say unnatural, has been so prevalent with the Vulgar, who were his chief Customers, that I have known this Victualler have more Trade for such Drink than his Neighours, who had much more wholsome at the same time; for the _Daucus_ Seed tho' it is a Carminative, and has some other good Properties, yet in the unboil'd Wort it is not capable of doing the Office of the Hop, in breaking thro' the clammy parts of it; the Hop being full of subtil penetrating Qualities, a Strengthener of the Stomach, and makes the Drink agreeble, by opposing Obstructions of the _Viscera_, and particularly of the Liver and Kidneys, as the Learned maintain, which confutes the old Notion, that Hops are a Breeder of the Stone in the Bladder. CHAP. XI. _Of Boiling Malt Liquors_. Altho' I have said an Hour and a half is requisite for boiling _October_ Beer, and an Hour for Ales and small Beer; yet it is to be observed, that an exact time is not altogether a certain Rule in this Case with some Brewers; for when loose Hops are boiled in the wort so long till they all sink, their Seeds will arise and fall down again; the wort also will be curdled, and broke into small Particles if examin'd in a Hand-bowl, but afterwards into larger, as big as great Pins heads, and will appear clean and fine at the Top. This is so much a Rule with some, that they regard not Time but this Sign to shew when the Wort is boiled enough; and this will happen sooner or later according to the Nature of the Barley and its being well Malted; for if it comes off Chalks or Gravels, it generally has the good Property of breaking or curdling soon; but if of tough Clays, then it is longer, which by some Persons is not a little valued, because it saves time in boiling, and consequently the Consumption of the Wort. It is also to be observed, that pale Malt Worts will not break so soon in the Copper, as the brown Sorts, but when either of their Worts boil, it should be to the purpose, for then they will break sooner and waste less than if they are kept Simmering, and will likewise work more kindly in the Tun, drink smoother, and keep longer. Now all Malt Worts may be spoiled by too little or too much boiling; if too little, then the Drink will always taste raw, mawkish, and be unwholsome in the Stomach, where, instead of helping to dilute and digest our Food, it will cause Obstructions, Colicks, Head-achs, and other misfortunes; besides, all such underboil'd Drinks are certainly exposed to staleness and sowerness, much sooner than those that have had their full time in the Copper. And if they are boiled too long, they will then thicken (for one may boil a Wort to a Salve) and not come out of the Copper fine and in a right Condition, which will cause it never to be right clear in the Barrel; an _Item_ sufficient to shew the mistake of all those that think to excel in Malt Liquors, by boiling them two or three Hours, to the great Confusion of the Wort, and doing more harm than good to the Drink. But to be more particular in those two Extreams, it is my Opinion, as I have said before, that no Ale Worts boiled less than an Hour can be good, because in an Hour's time they cannot acquire a thickness of Body any ways detrimental to them, and in less than an Hour the ramous viscid parts of the Ale cannot be sufficiently broke and divided, so as to prevent it running into Cohesions, Ropyness and Sowerness, because in Ales there are not Hops enough allowed to do this, which good boiling must in a great measure supply, or else such Drink I am sure can never be agreeable to the Body of Man; for then its cohesive Parts being not thoroughly broke and comminuted by time and boiling, remains in a hard texture of Parts, which consequently obliges the Stomach to work more than ordinary to digest and secrete such parboiled Liquor, that time and fire should have cured before: Is not this apparent in half boil'd Meats, or under-bak'd Bread, that often causes the Stomach a great fatigue to digest, especially in those of a sedentary Life; and if that suffers, 'tis certain the whole Body must share in it: How ignorant then are those People, who, in tipling of such Liquor, can praise it for excellent good Ale, as I have been an eye-witness of, and only because its taste is sweetish, (which is the nature of such raw Drinks) as believing it to be the pure Effects of the genuine Malt, not perceiving the Landlord's Avarice and Cunning to save the Consumption of his Wort by shortness of boiling, tho' to the great Prejudice of the Drinker's Health; and because a Liquid does not afford such a plain ocular Demonstration, as Meat and Bread does, these deluded People are taken into an Approbation of indeed an _Ignis fatuus_, or what is not. To come then to the _Crisis_ of the Matter, both Time and the Curdling or Breaking of the Wort should be consulted; for if a Person was to boil the Wort an Hour, and then take it out of the Copper, before it was rightly broke, it would be wrong management, and the Drink would not be fine nor wholsome; and if it should boil an Hour and a half, or two Hours, without regarding when its Particles are in a right order, then it may be too thick, so that due Care must be had to the two extreams to obtain it its due order; therefore in _October_ and keeping Beers, an Hour and a quarter's good boiling is commonly sufficient to have a thorough cured Drink, for generally in that time it will break and boil enough, and because in this there is a double Security by length of boiling, and a quantity of Hops shifted; but in the new way there is only a single one, and that is by a double or treble allowance of fresh Hops boiled only half an Hour in the Wort, and for this Practice a Reason is assigned, that the Hops being endowed with discutient apertive Qualities, will by them and their great quantity supply the Defect of underboiling the Wort; and that a further Conveniency is here enjoyed by having only the fine wholsome strong flowery spirituous Parts of the Hop in the Drink, exclusive of the phlegmatick nasty earthy Parts which would be extracted if the Hops were to be boiled above half an Hour; and therefore there are many now, that are so attach'd to this new Method, that they won't brew Ale or _October_ Beer any other way, vouching it to be a true Tenet, that if Hops are boiled above thirty Minutes, the wort will have some or more of their worser Quality. The allowance of Hops for Ale or Beer, cannot be exactly adjusted without coming to Particulars, because the Proportion should be according to the nature and quality of the Malt, the Season of the Year it is brew'd in, and the length of time it is to be kept. For strong brown Ale brew'd in any of the Winter Months, and boiled an Hour, one Pound is but barely sufficient for a Hogshead, if it be Tapp'd in three Weeks or a Month. If for pale Ale brewed at that time and for that Age, one Pound and a quarter of Hops; but if these Ales are brewed in any of the Summer Months, there should be more Hops allowed. For _October_ or _March_ brown Beer, a Hogshead made from Eleven Bushels of Malt, boiled an Hour and a quarter to be kept Nine Months, three Pounds and a half ought to be boiled in such Drink at the least. For _October_ or _March_, pale Beer made from fourteen Bushels, boiled an Hour and a quarter, and kept Twelve Months, six Pound ought to be allowed to a Hogshead of such Drink, and more if the Hops are shifted in two Bags, and less time given the Wort to boil. Now those that are of Opinion, that their Beer and Ales are greatly improved by boiling the Hops only half an Hour in the Wort, I joyn in Sentiment with them, as being very sure by repeated Experience it is so; but I must here take leave to dissent from those that think that half an Hour's boiling the Wort is full enough for making right sound and well relished Malt Drinks; however of this I have amply and more particularly wrote in my Second Book of Brewing in Chapter IV, where I have plainly publish'd the true Sign or Criterion to know when the Wort is boiled just enough, and which I intend to publish in a little time. CHAP. XII. _Of Foxing or Tainting Malt Liquors_. Foxing is a misfortune, or rather a Disease in Malt Drinks, occasioned by divers Means, as the Nastiness of the Utensils, putting the Worts too thick together in the Backs or Cooler, Brewing too often and soon one after another, and sometimes by bad Malts and Waters, and the Liquors taken in wrong Heats, being of such pernicious Consequence to the great Brewer in particular, that he sometimes cannot recover and bring his Matters into a right Order again under a Week or two, and is so hateful to him in its very Name, that it is a general Law among them to make all Servants that Name the word _Fox_ or _Foxing_, in the Brewhouse to pay Sixpence, which obliges them to call it _Reynards_; for when once the Drink is Tainted, it may be smelt at some Distance somewhat like a _Fox_; It chiefly happens in hot weather, and causes the Beer and Ale so Tainted to acquire a fulsome sickish taste, that will if it is receive'd in a great degree become Ropy like Treacle, and in some short time turn Sour. This I have known so to surprize my small Beer Customers, that they have asked the Drayman what was the matter: He to act in his Master's Interest tells them a Lye, and says it is the goodness of the Malt that causes that sweetish mawkish taste, and then would brag at Home how cleverly he came off. I have had it also in the Country more than once, and that by the idleness and ignorance of my Servant, who when a Tub has been rinced out only with fair Water, has set it by for a clean one but this won't do with a careful Master for I oblige him to clean the Tub with a Hand-brush, Ashes, or Sand every Brewing, and so that I cannot scrape any Dirt up under my Nail. However as the Cure of this Disease has baffled the Efforts of many, I have been tempted to endeavour the finding out a Remedy for the great Malignity, and shall deliver the best I know on this Score. And here I shall mention the great Value of the Hop in preventing and curing the Fox in Malt Liquors. When the Wort is run into the Tub out of the mashing Vat, it is a very good way to throw some Hops directly into it before it is put into the Copper, and they will secure it against Sourness and Ropyness, that are the two Effects of fox'd Worts or Drinks, and is of such Power in this respect, that raw Worts may be kept some time, even, in hot weather, before they are boiled, and which is necessary; where there is a large Quantity of Malt used to a little Copper; but it is certain that the stronger Worts will keep longer with Hops than the smaller Sorts: So likewise if a Person has fewer Tubs than is wanting, and he is apprehensive his Worts will be Fox'd by too thick lying in the Coolers or working Tubs, then it will be a safe way to put some fresh Hops into such Tubs and work them with the Yeast as I have before hinted; or in case the Drink is already Foxed in the Fat or Tun, new Hops should be put in and work'd with it, and they will greatly fetch it again into a right Order; but then such Drink should be carefully taken clear off from its gross nasty Lee, which being mostly Tainted, would otherwise lye in the Barrel, corrupt and make it worse. Some will sift quick Lime into foxed Drinks while they are working in the Tun or Vat, that its Fire and Salts may break the Cohesions of the Beer or Ale, and burn away the stench, that the Corruption would always cause; but then such Drink should by a Peg at the bottom of the Vat be drawn off as fine as possible, and the Dregs left behind. There are many that do not conceive how their Drinks become Fox'd and Tainted for several Brewings together; but I have in Chapter VI, in my Second Book, made it appear, that the Taint is chiefly retain'd and lodged in the upright wooden Pins that fasten the Planks to the Joists, and how scalding Lye is a very efficacious Liquor to extirpate it out of the Utensils in a little time if rightly applied; and one other most powerful Ingredient that is now used by the greatest Artists for curing of the same. CHAP. XIII _Of fermenting and working of Beers and Ales, and the pernicious Practice of Beating in the Yeast detected_. This Subject in my Opinion has, long wanted a Satyrical Pen to shew the ill Effects of this unwholsome Method, which I suppose has been much discouraged and hindered hitherto, from the general use it has been under many Years, especially by the _Northern_ Brewers, who tho' much famed for their Knowledge in this Art, and have induced many others by their Example in the _Southern_ and other Parts to pursue their Method; yet I shall endeavour to prove them culpable of Male-practice, that beat in the Yeast, as some of them have done a Week together; and that Custom ought not to Authorize an ill Practice. _First_, I shall observe that Yeast is a very strong acid, that abounds with subtil spirituous Qualities, whose Particles being wrapped up in those that are viscid, are by a mixture with them in the Wort, brought into an intestine Motion, occasion'd by Particles of different Gravities; for as the spirituous Parts of the Wort will be continually striving to get up to the Surface, the glutinous adhesive ones of the Yeast will be as constant in retarding their assent, and so prevent their Escape; by which the spirituous Particles are set loose and free from their viscid Confinements, as may appear by the Froth on the Top, and to this end a moderate warmth hastens the Operation, as it assists in opening the viscidities in which some spirituous Parts may be entangled, and unbends the Spring of the included Air: The viscid Parts which are raised to the Top, not only on account of their own lightness, but by the continual efforts and occursions of the Spirits to get uppermost, shew when the ferment is at the highest, and prevent the finer Spirits making their escape; but if this intestine Operation is permitted to continue too long, a great deal will get away, and the remaining grow flat and vapid, as Dr. _Quincy_ well observes. Now tho' a small quantity of Yeast is necessary to break the Band of Corruption in the Wort, yet it is in itself of a poisonous Nature, as many other Acids are; for if a Plaister of thick Yeast be applied to the Wrist as some have done for an Ague, it will there raise little Pustules or Blisters in some degree like that Venomous! (As I have just reason in a particular Sense to call it) Ingredient _Cantharide_, which is one of the Shop Poisons. Here then I shall observe, that I have known several beat the Yeast into the Wort for a Week or more together to improve it, or in plainer terms to load the Wort with its weighty and strong spirituous Particles; and that for two Reasons, _First_, Because it will make the Liquor so heady, that five Bushels of Malt may be equal in strength to six, and that by the stupifying Narcotick Qualities of the Yeast; which mercenary subtilty and imposition has so prevailed to my Knowledge with the Vulgar and Ignorant, that it has caused many of them to return the next Day to the same Alehouse, as believing they had stronger and better Drink than others: But alas, how are such deceived that know no other than that it is the pure Product of the Malt, when at the same time they are driving Nails into their Coffins, by impregnating their Blood with the corrupt Qualities of this poisonous acid, as many of its Drinkers have proved, by suffering violent Head-achs, loss of Appetite, and other Inconveniencies the Day following, and sometimes longer, after a Debauch of such Liquor; who would not perhaps for a great reward swallow a Spoonful of thick Yeast by itself, and yet without any concern may receive for ought they know several, dissolved in the Vehicle of Ale, and then the corrosive Corpuscles of the Yeast being mix'd with the Ale, cannot fail (when forsaken in the Canals of the Body of their Vehicle) to do the same mischief as they would if taken by themselves undiluted, only with this difference, that they may in this Form be carried sometimes further in the animal Frame, and so discover their malignity in some of the inmost recesses thereof, which also is the very Case of malignant Waters, as a most learned Doctor observes. _Secondly_, They alledge for beating the Yeast into Wort, that it gives it a fine tang or relish, or as they call it at _London_, it makes the Ale bite of the Yeast; but this flourish indeed is for no other reason than to further its Sale, and tho' it may be agreeable to some Bigots, to me it proves a discovery of the infection by its nauseous taste; however my surprize is lessen'd, when I remember the _Plymouth_ People, who are quite the reverse of them at _Dover_ and _Chatham_; for the first are so attach'd to their white thick Ale, that many have undone themselves by drinking it; nor is their humour much different as to the common Brewers brown Ale, who when the Customer wants a Hogshead, they immediately put in a Handful of Salt and another of Flower, and so bring it up, this is no sooner on the Stilling but often Tapp'd, that it may carry a Froth on the Top of the Pot, otherwise they despise it: The Salt commonly answered its End of causing the Tiplers to become dryer by the great Quantities they drank, that it farther excited by the biting pleasant stimulating quality the Salt strikes the Palate with. The Flower also had its seducing share by pleasing the Eye and Mouth with its mantling Froth, so that the Sailors that are often here in great Numbers used to consume many Hogsheads of this common Ale with much delight, as thinking it was intirely the pure Product of the Malt. Their white Ale is a clear Wort made from pale Malt, and fermented with what they call ripening, which is a Composition, they say, of the Flower of Malt, Yeast and Whites of Eggs, a _Nostrum_ made and sold only by two or three in those Parts, but the Wort is brewed and the Ale vended by many of the Publicans; which is drank while it is fermenting in Earthen Steens, in such a thick manner as resembles butter'd Ale, and sold for Twopence Halfpenny the full Quart. It is often prescribed by Physicians to be drank by wet Nurses for the encrease of their Milk, and also as a prevalent Medicine for the Colick and Gravel. But the _Dover_ and _Chatham_ People won't drink their Butt-Beer, unless it is Aged, fine and strong. _Of working and fermenting_ London _Stout Beer and Ale_. In my Brewhouse at _London_, the Yeast at once was put into the Tun to work the Stout Beer and Ale with, as not having the Conveniency of doing otherwise, by reason the After-worts of small Beer comes into the same Backs or Coolers where the strong Worts had just been, by this means, and the shortness of time we have to ferment our strong Drinks, we cannot make Reserves of cold Worts to mix with and check the too forward working of those Liquors, for there we brewed three times a Week throughout the Year, as most of the great ones do in _London_, and some others five times. The strong Beer brewed for keeping is suffered to be Blood-warm in the Winter when the Yeast is put into it, that it may gradually work two Nights and a Day at least, for this won't admit of such a hasty Operation as the common brown Ale will, because if it is work'd too warm and hasty, such Beer won't keep near so long as that fermented cooler. The brown Ale has indeed its Yeast put into it in the Evening very warm, because they carry it away the very next Morning early to their Customers, who commonly draw it out in less than a Week's time. The Pale or Amber Ales are often kept near it, not quite a Week under a fermentation, for the better incorporating the Yeast with Wort, by beating it in several times for the foregoing Reasons. _Of working or fermenting Drinks brewed by Private Families_. I mean such who Brew only for their own use, whether it be a private Family or a Victualler. In this Case be it for Stout Beers, or for any of the Ales; the way that is used in _Northamptonshire_, and by good Brewers elsewhere; is, to put some Yeast into a small quantity of warm Wort in a Hand-bowl, which for a little while swims on the Top, where it works out and leisurely mixes with the Wort, that is first quite cold in Summer, and almost so in Winter; for the cooler it is work'd the longer it will keep, too much Heat agitating the spirituous Particles into too quick a motion, whereby they spend themselves too fast, or fly away too soon, and then the Drink will certainly work into a blister'd Head that is never natural; but when it ferments by moderate degrees into a fine white curl'd Head, its Operation is then truly genuine, and plainly shews the right management of the Brewer. To one Hogshead of Beer, that is to be kept nine Months, I put a Quart of thick Yeast, and ferment it as cool as it will admit of, two Days together, in _October_ or _March_, and if I find it works too fast, I check it at leisure by stirring in some raw Wort with a Hand-bowl: So likewise in our Country Ales we take the very same method, because of having them keep some time, and this is so nicely observed by several, that I have seen them do the very same by their small Beer Wort; now by these several Additions of raw Wort, there are as often new Commotions raised in the Beer or Ale, which cannot but contribute to the rarefaction and comminution of the whole; but whether it is by these joining Principles of the Wort and Yeast, that the Drink is rendered smoother, or that the spirituous Parts are more entangled and kept from making their Escape, I can't determine; yet sure it is, that such small Liquors generally sparkle and knit out of the Barrel as others out of a Bottle, and is as pleasant Ale as ever I drank. Others again for Butt or Stout Beer will, when they find it works up towards a thick Yeast, mix it once and beat it in again with the Hand-bowl or Jett; and when it has work'd up a second time in such a manner, they put it into the Vessel with the Yeast on the Top and the Sediments at Bottom, taking particular Care to have some more in a Tub near the Cask to fill it up as it works over, and when it has done working, leave it with a thick Head of Yeast on to preserve it. But for Ale that is not to be kept very long, they Hop it accordingly, and beat the Yeast in every four or five Hours for two Days successively in the warm weather, and four in the Winter till the Yeast begins to work heavy and sticks to the hollow part of the Bowl, if turned down on the same, then they take all the Yeast off at Top and leave all the Dregs behind, putting only up the clear Drink, and when it is a little work'd in the Barrel, it will be fine in a few Days and ready for drinking. But this, last way of beating in the Yeast too long, I think I have sufficiently detected, and hope, as it is how declining, it will never revive again, and for which reason I have in my second Book encouraged all light fermentations, as the most natural for the Malt Liquor and the human Body. _Of forwarding and retarding the fermentation of malt Liquors_. In case Beer or Ale is backward in working, it is often practised to cast some Flower out of the Dusting Box, or with the Hand over the Top of the Drink, which will become a sort of Crust or Cover to help to keep the Cold out: Others will put in one or two Ounces of powder'd Ginger, which will so heat the Wort as to bring it forward: Others will take a Gallon Stone Bottle and fill it with boiling water, which being well Cork'd, is put into the working Tub, where it will communicate a gradual Heat for some time and forward the fermentation: Others will reserve some raw Wort, which they heat and mix with the rest, but then due Care must be taken that the Pot in which it is heated has no manner of Grease about it lest it impedes, instead of promoting the working, and for this reason some nice Brewers will not suffer a Candle too near the Wort, lest it drop into it. But for retarding and keeping back any Drink that is too much heated in working, the cold raw Wort, as I have said before, is the most proper of any thing to check it with, tho' I have known some to put one or more Pewter Dishes into it for that purpose, or it may be broke into several other Tubs, where by its shallow lying it will be taken off its Fury. Others again, to make Drink work that is backward, will take the whites of two Eggs and beat them up with half a Quartern of good Brandy, and put it either into the working Vat, or into the Cask, and it will quickly bring it forward if a warm Cloth is put over the Bung. Others will tye up Bran in a coarse thin Cloth and put it into the Vat, where by its spungy and flowery Nature and close Bulk it will absorp a quantity of the Drink, and breed a heat to forward its working. I know an Inn-keeper of a great Town in _Bucks_ that is so curious as to take off all the top Yeast first, and then by a Peg near the bottom of his working Tub, he draws off the Beer or Ale, so that the Dreggs are by this means left behind. This I must own is very right in Ales that are to be drank soon, but in Beers that are to lye nine or twelve Months in a Butt or other Cask, there certainly will be wanted some Feces or Sediment for the Beer to feed on, else it must consequently grow hungry, sharp and eager; and therefore if its own top and bottom are not put into a Cask with the Beer, some other Artificial Composition or Lee should supply its Place, that is wholsomer, and will better feed with such Drink than its own natural Settlement, and therefore I have here inserted several curious Receipts for answering this great End. CHAP. XIV. _Of an Artificial Lee for Stout or Stale Beer to feed on_. This Article, as it is of very great Importance in the curing of our malt Liquors, requires a particular regard to this last management of them, because in my Opinion the general misfortune of the Butt or keeping Beers drinking so hard and harsh, is partly owing to the nasty foul Feces that lye at the bottom of the Cask, compounded of the Sediments of Malt, Hops and Yeast, that are, all Clogg'd with gross rigid Salts, which by their long lying in the Butt or other Vessel, so tinctures the Beer as to make it partake of all their raw Natures: For such is the Feed, such is the Body, as may be perceived by Eels taken out of dirty Bottoms, that are sure to have a muddy taste, when the Silver sort that are catched in Gravelly or Sandy clear Rivers Eat sweet and fine: Nor can this ill property be a little in those Starting (as they call it in _London_) new thick Beers that were carry'd directly from my Brewhouse, and by a Leather Pipe or Spout conveyed into the Butt as they stood in the Cellar, which I shall further demonstrate by the Example of whole Wheat, that is, by many put into such Beer to feed and preserve it, as being reckoned a substantial Alcali; however it has been proved that such Wheat in about three Years time has eat into the very Wood of the Cask, and there Hony-comb'd it by making little hollow Cavities in the Staves. Others there are that will hang a Bag of Wheat in the Vessel that it mayn't touch the Bottom, but in both Cases the Wheat is discovered to absorp and collect the saline acid qualities of the Beer, Yeast and Hop, by which it is impregnated with their sharp qualities, as a Toast of Bread is put into Punch or Beer, whose alcalous hollow Nature will attract and make a Lodgment of the acid strong Particles in either, as is proved by eating the inebriating Toast, and therefore the _Frenchman_ says, the _English_ are right in putting a Toast into the Liquor, but are Fools for eating it: Hence it is that such whole Wheat is loaded with the qualities of the unwholsome Settlements or Grounds of the Beer, and becomes of such a corroding Nature, as to do this mischief; and for that reason, some in the _North_ will hang a Bag of the Flower of malted Oats, Wheat, Pease and Beans in the Vessels of Beer, as being a lighter and mellower Body than whole Wheat or its Flower, and more natural to the Liquor: But whether it be raw Wheat or Malted, it is supposed, after this receptacle has emitted its alcalous Properties to the Beer, and taken in all it can of the acid qualities thereof, that such Beer will by length of Age prey upon that again, and so communicate its pernicious Effects to the Body of Man, as Experience seems to justify by the many sad Examples that I have seen in the Destruction of several lusty Brewers Servants, who formerly scorn'd what they then called Flux Ale, to the preference of such corroding consuming Stale Beers; and therefore I have hereafter advised that such Butt or keeping Beers be Tapp'd at nine or twelve Months end at furthest, and then an Artificial Lee will have a due time allowed it to do good and not harm. _An Excellent Composition for feeding Butts or keeping Beers with_. Take a Quart of _French_ Brandy, or as much of _English_, that is free from any burnt Tang, or other ill taste, and is full Proof, to this put as much Wheat or Flower as will knead it into a Dough, put it in long pieces into the Bung Hole, as soon as the Beer has done working, or afterwards, and let it gently fall piece by piece to the bottom of the Butt, this will maintain the Drink in a mellow freshness, keep staleness off for some time, and cause it to be the stronger as it grows Aged. ANOTHER. Take one Pound of Treacle or Honey, one Pound of the Powder of dryed Oyster-shells or fat Chalk, mix them well and put it into a Butt, as soon as it has done working or some time after, and Bung it well, this will both fine and preserve the Beer in a soft, smooth Condition for a great while. ANOTHER. Take a Peck of Egg-shells and dry them in an Oven, break and mix them with two Pound of fat Chalk, and mix them with water wherein four Pounds of coarse Sugar has been boiled, and put it into the Butt as aforesaid. _To fine and preserve Beers and Ales by boiling an Ingredient in the Wort_. This most valuable way I frequently follow both for Ale, Butt-beer and Small Beer, and that is, in each Barrel Copper of Wort, I put in a Pottle, or two Quarts of whole Wheat as soon as I can, that it may soak before it boils, then I strain it thro' a Sieve, when I put the Wort in cooling Tubs, and if it is thought fit the same Wheat may be boiled in a second Copper: Thus there will be extracted a gluey Consistence, which being incorporated with the Wort by boiling, gives it a more thick and ponderous Body, and when in the Cask, soon makes a Sediment or Lee, as the Wort is more or less loaded with the weighty Particles of this fizy Body; but if such Wheat was first parched or baked in an Oven, it would do better, as being rather too raw as it comes from the Ear. _Another Way_. A Woman, who lived at _Leighton Buzzard_ in _Bedfordshire_, and had the best Ale in the Town, once told a Gentleman, she had Drink just done working in the Barrel, and before it was Bung'd would wager it was fine enough to Drink out of a Glass, in which it should maintain a little while a high Froth; and it was true, for the Ivory shavings that she boiled in her Wort, was the Cause of it, which an Acquaintance of mine accidentally had a View of as they lay spread over the Wort in the Copper; so will Hartshorn shavings do the same and better, both of them being great finers and preservers of malt Liquors against staleness and sourness, and are certainly of a very alcalous Nature. Or if they are put into a Cask when you Bung it down, it will be of service for that purpose; but these are dear in Comparison of the whole Wheat, which will in a great measure supply their Place, and after it is used, may be given to a poor Body, or to the Hog. _To stop the Fret in Malt Liquors_. Take a Quart of Black Cherry Brandy, and pour it in at the Bung-hole of the Hogshead and stop it close. _To recover deadish Beer_. When strong Drink grows flat, by the loss of its Spirits, take four or five Gallons out of a Hogshead, and boil it with five Pound of Honey, skim it, and when cold, put it to the rest, and stop it up close: This will make it pleasant, quick and strong. _To make stale Beer drink new_. Take the Herb _Horehound_ stamp it and strain it, then put a Spoonful of the juice (which is an extream good Pectoral) to a pitcher-full of Beer, let it stand covered about two Hours and drink it. _To fine Malt Liquors_. Take a pint of water, half an Ounce of unslack'd Lime, mix them well together, let it stand three Hours and the Lime will settle to the Bottom, and the water be as clear as Glass, pour the water from the Sediment, and put it into your Ale or Beer, mix it with half an Ounce of Ising-glass first cut small and boiled, and in five Hours time or less the Beer in the Barrel will settle and clear. There are several other Compositions that may be used for this purpose, but none that I ever heard of will answer like those most Excellent Balls that Mr. _Ellis_ of _Little Gaddesden_ in _Hertfordshire_ has found out by his own Experience to be very great Refiners, Preservers and Relishers of Malt Liquors and Cyders, and will also recover damag'd Drinks, as I have mentioned in my Second Book, where I have given a further Account of some other things that will fine, colour and improve Malt Drinks: The Balls are sold at [missing text] CHAP. XV. _Of several pernicious Ingredients put into Malt Liquors to encrease their Strength_. Malt Liquors, as well as several others, have long lain under the disreputation of being adulterated and greatly abused by avaricious and ill-principled People, to augment their Profits at the Expence of the precious Health of human Bodies, which, tho' the greatest Jewel in Life, is said to be too often lost by the Deceit of the Brewer, and the Intemperance of the Drinker: This undoubtedly was one, and I believe the greatest, of the Lord _Bacon's_ Reasons for saying, he thought not one _Englishman_ in a thousand died a natural Death. Nor is it indeed to be much wondered at, when, according to Report, several of the Publicans make it their Business to study and practise this Art, witness what I am afraid is too true, that some have made use of the _Coculus India_ Berry for making Drink heady, and saving the Expence of Malt; but as this is a violent Potion by its narcotick stupifying Quality, if taken in too large a degree, I hope this will be rather a prevention of its use than an invitation, it being so much of the nature of the deadly Nightshade, that it bears the same Character; and I am sure the latter is bad enough; for one of my Neighbour's Brothers was killed by eating its Berries that grow in some of our Hedges, and so neatly resembles the black Cherry, that the Boy took the wrong for the right. There is another sinister Practice said to be frequently used by ill Persons to supply the full quantity of Malt, and that is _Coriander_ Seeds: This also is of a heady nature boiled in the Wort, one Pound of which will answer to a Bushel of Malt, as was ingenuously confess'd to me by a Gardener, who own'd he sold a great deal of it to Alehouse Brewers (for I don't suppose the great Brewer would be concern'd in any such Affair) for that purpose, purpose, at Ten-pence per Pound; but how wretchedly ignorant are those that make use of it, not knowing the way first to cure and prepare it for this and other mixtures, without which it is a dangerous thing, and will cause Sickness in the Drinkers of it. Others are said to make use of Lime-stones to fine and preserve the Drink; but to come off the fairest in such foul Artifices, it has been too much a general Practice to beat the Yeast so long into the Ale, that without doubt it has done great Prejudice to the Healths of many others besides the Person I have writ of in the Preface of my Second Book. For the sake then of Seller and Buyer, I have here offered several valuable Receipts for fining, preserving and mellowing Beers and Ales, in such a true healthful and beneficial manner, that from henceforth after the Perusal of this Book, and the knowledge of their worth are fully known, no Person, I hope, will be so sordidly obstinate as to have any thing to do with such unwholsome Ingredients; because these are not only of the cheapest sort, but will answer their End and Purpose; and the rather, since Malts are now only twenty Shillings per Quarter, and like to hold a low Price for Reasons that I could here assign. I own, I formerly thought they were too valuable to expose to the Publick by reason of their Cheapness and great Virtues, as being most of them wholsomer than the Malt itself, which is but a corrupted Grain. But, as I hope they will do considerable Service in the World towards having clear salubrious and pleasant Malt Liquors in most private Families and Alehouses, I have my Satisfaction. CHAP. XVI. _Of the Cellar or Repository for keeping Beers and Ales_. It's certain by long Experience, that the Weather or Air has not only a Power or Influence in Brewings; but also after the Drink is in the Barrel, Hogshead or Butt, in Cellars or other Places, which is often the cause of forwarding or retarding the fineness of Malt Liquors; for if we brew in cold Weather, and the Drink is to stand in a Cellar of Clay, or where Springs rise, or Waters lye or pass through, such a Place by consequence will check the due working of the Drink, chill, flat, deaden and hinder it from becoming fine. So likewise if Beer or Ale is brewed in hot Weather and put into Chalky, Gravelly or Sandy Cellars, and especially if the Windows open to the South, South-East, or South-West, then it is very likely it will not keep long, but be muddy and stale: Therefore, to keep Beer in such a Cellar, it should be brewed in _October_, that the Drink may have time to cure itself before the hot Weather comes on; but in wettish or damp Cellars, 'tis best to Brew in _March_, that the Drink may have time to fine and settle before the Winter Weather is advanced. Now such Cellar Extremities should, if it could be done, be brought into a temperate State, for which purpose some have been so curious as to have double or treble Doors to their Cellar to keep the Air out, and then carefully shut the outward, before they enter the inward one, whereby it will be more secure from aerial Alterations; for in Cellars and Places, that are most exposed to such Seasons, Malt Liquors are frequently disturb'd and made unfit for a nice Drinker; therefore if a Cellar is kept dry and these Doors to it, it is reckoned warm in Winter and cool in Summer, but the best of Cellars are thought to be those in Chalks, Gravels or Sands, and particularly in Chalks, which are of a drying quality more than any other, and consequently dissipates Damps the most of all Earths, which makes it contribute much to the good keeping of the Drink; for all damp Cellars are prejudicial to the Preservation of Beers and Ales, and sooner bring on the rotting of the Casks and Hoops than the dry ones; Insomuch that in a chalky Cellar near me, their Ashen broad Hoops have lasted above thirty Years. Besides, in such inclosed Cellars and temperate Air, the Beers and Ales ripen more kindly, are better digested and softned, and drink smoother: But when the Air is in a disproportion by the Cellars letting in Heats and Colds, the Drink will grow Stale and be disturbed, sooner than when the Air is kept out. From hence it is, that in some Places their Malt Liquors are exceeding good, because they brew with Pale or Amber Malts, Chalky Water, and keep their Drinks in close Vaults or proper dry Cellars, which is of such Importance, that notwithstanding any Malt Liquor may be truly brewed, yet it may be spoiled in a bad Cellar that may cause such alternate Fermentations as to make it thick and sour, tho' it sometimes happens that after such Changes it fines itself again; and to prevent these Commotions of the Beer, some brew their pale Malt in _March_ and their brown in _October_, for that the pale Malt, having not so many fiery Particles in it as the brown, stands more in need of the Summer's Weather to ripen it, while the brown sort being more hard and dry is better able to defend itself against the Winter Colds that will help to smooth its harsh Particles; yet when they happen to be too violent, Horse-dung should be laid to the Windows as a Fortification against them; but if there were no Lights at all to a Cellar, it would be better. Some are of Opinion, that _October_ is the best of all other Months to brew any sort of Malt in, by reason there are so many cold Months directly follow, that will digest the Drink and make it much excel that Brewed in _March_ because such Beer will not want that Care and Watching, as that brewed in _March_ absolutely requires, by often taking out and putting in the Vent-peg on Change of Weather; and if it is always left out, then it deadens and palls the Drink; yet if due Care is not taken in this respect, a Thunder or Stormy Night may marr all, by making the Drink ferment and burst the Cask; for which Reason, as Iron Hoops are most in Fashion at this time, they are certainly the greatest Security to the safety of the Drink thus exposed; and next to them is the Chesnut Hoop; both which will endure a shorter or longer time as the Cellar is more or less dry, and the Management attending them. The Iron Hoop generally begins to rust first at the Edges, and therefore should be rubbed off when opportunity offers, and be both kept from wet as much as possible; for 'tis Rust that eats the Iron Hoop in two sometimes in ten or twelve Years, when the Ashen and Chesnut in dry Cellars have lasted three times as long. CHAP. XVII. _Of Cleaning and Sweetening of Casks_. In Case your Cask is a Butt, then with cold Water first rince out the Lees clean, and have ready, boiling or very hot Water, which put in, and with a long Stale and a little Birch fastened to its End, scrub the Bottom as well as you can. At the same time let there be provided another shorter Broom of about a Foot and a half long, that with one Hand may be so imployed in the upper and other Parts as to clean the Cask well: So in a Hogshead or other smaller Vessel, the one-handed short Broom may be used with Water, or with Water, Sand or Ashes, and be effectually cleaned; the outside of the Cask about the Bung-hole should be well washed, lest the Yeast, as it works over, carries some of its Filth with it. But to sweeten a Barrel, Kilderkin, Firkin or Pin in the great Brewhouses, they put them over the Copper Hole for a Night together, that the Steam of the boiling Water or Wort may penetrate into the Wood; this Way is such a furious Searcher, that unless the Cask is new hooped just before, it will be apt to fall in pieces. _Another Way_. Take a Pottle, or more, of Stone Lime, and put it into the Cask; on this pour some Water and stop it up directly, shaking it well about. _Another Way_. Take a long Linnen Rag and dip it in melted Brimstone, light it at the end, and let it hang pendant with the upper part of the Rag fastened to the wooden Bung; this is a most quick sure Way, and will not only sweeten, but help to fine the Drink. _Another_. Or to make your Cask more pleasant, you may use the Vintners Way thus: Take four Ounces of Stone Brimstone, one Ounce of burnt Alum, and two Ounces of Brandy; melt all these in an Earthen Pan over hot Coals, and dip therein a piece of new Canvas, and instantly sprinkle thereon the Powders of Nutmegs, Cloves, Coriander and Anise-seeds: This Canvas set on fire, and let it burn hanging in the Cask fastened at the end with the wooden Bung, so that no Smoke comes out. _For a Musty Cask_. Boil some Pepper in water and fill the Cask with it scalding hot. _For a very stinking Vessel_. The last Remedy is the Coopers taking out one of the Heads of the Cask to scrape the inside, or new-shave the Staves, and is the surest way of all others, if it is fired afterwards within-side a small matter, as the Cooper knows how. These several Methods may be made use of at Discretion, and will be of great Service where they are wanted. The sooner also a Remedy is applied, the better; else the Taint commonly encreases, as many have to their prejudice proved, who have made use of such Casks, in hopes the next Beer will overcome it; but when once a Cask is infected, it will be a long while, if ever, before it becomes sweet, if no Art is used. Many therefore of the careful sort, in case they han't a Convenience to fill their Vessel as soon as it is empty, will stop it close, to prevent the Air and preserve the Lees sound, which will greatly tend to the keeping of the Cask pure and sweet against the next Occasion. _To prepare a new Vessel to keep Malt Liquors in_. A new Vessel is most improperly used by some ignorant People for strong Drink after only once or twice scalding with Water, which is so wrong, that such Beer or Ale will not fail of tasting thereof for half, if not a whole Year afterwards; such is the Tang of the Oak and its Bark, as may be observed from the strong Scents of Tan-Yards, which the Bark is one cause of. To prevent then this Inconvenience, when your Brewing is over put up some Water scalding hot, and let it run throu' the Grains, then boil it and fill up the Cask, stop it well and let it stand till it is cold, do this twice, then take the Grounds of strong Drink and boil in it green Wallnut Leaves and new Hay or Wheat Straw, and put all into the Cask, that it be full and stop it close. After this, use it for small Beer half a Year together, and then it will be thoroughly sweet and fit for strong Drinks; or _Another Way_. Take a new Cask and dig a Hole in the Ground, in which it may lye half depth with the Bung downwards; let it remain a Week, and it will greatly help this or any stinking musty Cask. But besides these, I have writ of two other excellent Ways to sweeten musty or stinking Casks, in my Second Book of Brewing. _Wine Casks_. These, in my Opinion, are the cheapest of all others to furnish a Person readily with, as being many of them good Casks for Malt Liquors, because the Sack and White-Wine sorts are already season'd to Hand, and will greatly improve Beers and Ales that are put in them: But beware of the Rhenish Wine Cask for strong Drinks; for its Wood is so tinctured with this sharp Wine, that it will hardly ever be free of it, and therefore such Cask is best used for Small Beer: The Claret Cask will a great deal sooner be brought into a serviceable State for holding strong Drink, if it is two or three times scalded with Grounds of Barrels, and afterwards used for small Beer for some time. I have bought a Butt or Pipe for eight Shillings in _London_ with some Iron Hoops on it, a good Hogshead for the same, and the half Hogshead for five Shillings, the Carriage for a Butt by the Waggon thirty Miles is two Shillings and Sixpence, and the Hogshead Eighteen-pence: But, to cure a Claret Cask of its Colour and Taste, put a Peck of Stone-Lime into a Hogshead, and pour upon it three Pails of Water; bung immediately with a Wood-or Cork Bung, and shake it well about a quarter of an Hour, and let it stand a Day and Night and it will bring off the red Colour, and alter the Taste of the Cask very much. But of three several other excellent Methods for curing musty, stinking, new and other tainted Casks, I have writ of in my Account of Casks in my Second Book. CHAP. XVIII. _Of Bunging Casks and Carrying of Malt Liquors to some distance_. I am sure this is of no small Consequence, however it may be esteemed as a light matter by some; for if this is not duly perform'd, all our Charge, Labour and Care will be lost; and therefore here I shall dissent from my _London_ Fashion, where I bung'd up my Ale with Pots of Clay only, or with Clay mix'd with Bay Salt, which is the better of the two, because this Salt will keep the Clay moist longer than in its Original State; and the Butt Beers and fine Ales were Bung'd with Cork drove in with a piece of Hop-Sack or Rag, which I think are all insipid, and the occasion of spoiling great Quantities of Drink, especially the small Beers; for when the Clay is dry, which is soon in Summer, there cannot be a regular Vent thro' it, and then the Drink from that time flattens and stales to the great loss in a Year to some Owners, and the Benefit of the Brewer; for then a fresh Cask must be Tapp'd to supply it, and the remaining part of the other throw'd away. Now, to prevent this great Inconvenience, my Bung-holes are not quite of the largest size of all, and yet big enough for the common wooden Iron Hoop'd Funnel used in some Brew-houses: In this I put in a turned piece of Ash or Sallow three Inches broad at Top, and two Inches and a half long, first putting in a double piece of dry brown Paper, that is so broad that an Inch or more may be out of it, after the wooden Bung is drove down with a Hammer pretty tight; this Paper must be furl'd or twisted round the Bung, and another loose piece upon and around that, with a little Yeast, and a small Peg put into the Bung, which is to be raised at Discretion when the Beer is drawing, or at other times to give it Vent if there should be occasion: Others will put some Coal or Wood Ashes wetted round this Bung, which will bind very hard, and prevent any Air getting into or out of the Cask; but this in time is apt to rot, and wear the Bung-hole by the Salt or Sulphur in the Ashes, and employing a Knife to scrape it afterwards. Yet, for keeping Beers, it's the best Security of all other ways whatsoever. There is also a late Invention practised by a common Brewer in the Country that I am acquainted with, for the safe Carriage of Drink on Drays, to some distance without losing any of it, and that is in the Top Center of one of these Bungs, he puts in a wooden Funnel, whose Spout is about four Inches long, and less than half an Inch Diameter at Bottom; this is turned at Top into a concave Fashion like a hollow round Bowl, that will hold about a Pint, which is a constant Vent to the Cask, and yet hinders the Liquor from ascending no faster than the Bowl can receive, and return it again into the Barrel: I may say further, he has brought a Barrel two Miles, and it was then full, when it arrived at his Customers, because the Pint that was put into the Funnel, at setting out, was not at all lost when he took it off the Dray; this may be also made of Tin; and will serve from the Butt to the small Cask. In the Butt there is a Cork-hole made about two Inches below the upper Head, and close under that a piece of Leather is nailed Spout-fashion, that jetts three Inches out, from which the Yeast works and falls into a Tub, and when the working is over the Cork is put closely in, for the Bung in the Head of the upright Cask is put in as soon as it is filled up with new Drink: Now when such a Cask is to be broach'd and a quick Draught is to follow, then it may be tapp'd at Bottom; but if otherwise, the Brass Cock ought to be first put in at the middle, and before the Drink sinks to that it should be Tapp'd at Bottom to prevent the breaking of the Head of Yeast, and its growing stale, flat and sour. In some Places in the Country when they brew Ale or Beer to send to _London_ at a great Distance, they let it be a Year old before they Tap it, so that then it is perfectly fine; this they put into small Casks that have a Bung-hole only fit for a large Cork, and then they immediately put in a Role of Bean-flour first kneaded with Water or Drink, and baked in an Oven, which is all secured by pitching in the Cork, and so sent in the Waggon; the Bean-flour feeding and preserving the Body of the Drink all the way, without fretting or causing it to burst the Cask for want of Vent, and when Tapp'd will also make the Drink very brisk, because the Flour is in such a hard Consistence, that it won't dissolve in that time; but if a little does mix with the Ale or Beer, its heavy Parts will sooner fine than thicken the Drink and keep it mellow and lively to the last, if Air is kept out of the Barrel. CHAP. XIX. _Of the Strength and Age of Malt Liquors_. Whether they be Ales or strong Beers, it is certain that the midling sort is allowed by Physicians to be the most agreeable of any, especially to those of a sedentary Life, or those that are not occupied in such Business as promotes Perspiration enough to throw out and break the Viscidities of the stronger sorts; on which account the laborious Man has the advantage, whose Diet being poor and Body robust, the strength of such Liquors gives a Supply and better digests into Nourishment: But for the unactive Man a Hogshead of Ale which is made from six Bushels of Malt is sufficient for a Diluter of their Food, and will better assist their Constitution than the more strong sort, that would in such produce Obstructions and ill Humours; and therefore that Quantity for Ale, and ten Bushels for a Hogshead of strong Beer that should not be Tapp'd under nine Months, is the most healthful. And this I have experienc'd by enjoying such an Amber Liquor that has been truly brewed from good Malt, as to be of a Vinous Nature, that would permit of a hearty Dose over Night, and yet the next Morning leave a Person light, brisk and unconcern'd. This then is the true Nostrum of Brewing, and ought to be studied and endeavoured for by all those that can afford to follow the foregoing Rules, and then it will supply in a great measure those chargeable (and often adulterated tartarous arthritick) Wines. So likewise for small Beer, especially in a Farmer's Family where it is not of a Body enough, the Drinkers will be feeble in hot Weather and not be able to perform their Work, and will also bring on Distempers, besides the loss of time, and a great waste of such Beer that is generally much thrown away; because Drink is certainly a Nourisher of the Body, as well as Meats, and the more substantial they both are, the better will the Labourer go through his Work, especially at Harvest; and in large Families the Doctor's Bills have proved the Evil of this bad Oeconomy, and far surmounted the Charge of that Malt that would have kept the Servants in good Health, and preserved the Beer from such Waste as the smaller sort is liable to. 'Tis therefore that some prudent Farmers will brew their Ale and small Beer in _March_, by allowing of five or six Bushels of Malt, and two Pounds of Hops to the Hogshead of Ale, and a quarter of Malt and three Pounds of Hops to five Barrels of small Beer. Others there are, that will brew their Ale or strong Beer in _October_, and their small Beer a Month before it is wanted. Others will brew their Ale and small Beer in _April, May_ and _June_; but this according to humour, and therefore I have hinted of the several Seasons for Brewing these Liquors: However in my Opinion, whether it be strong or small Drinks, they should be clear, smooth and not too small, if they are design'd for Profit and Health; for if they are otherwise, it will be a sad Evil to Harvest Men, because then they stand most in need of the greatest Balsamicks: To this end some of the softning Ingredients mentioned in the foregoing Receipts should be made use of to feed it accordingly, if these Drinks are brewed forward. And that this particular important Article in the Brewing Oeconomy may be better understood, I shall here recite Dr. _Quincy_'s Opinion of Malt Liquors, viz. The Age of Malt Drinks makes them more or less wholsome, and seems to do somewhat the same as Hops; for those Liquors which are longest kept, are certainly the least viscid; Age by degrees breaking the viscid Parts, and rendering them smaller, makes them finer for Secretion; but this is always to be determined by their Strength, because in Proportion to that will they sooner or later come to their full Perfection and likewise their Decay, until the finer Spirits quite make their Escape, and the remainder becomes vapid and sour. By what therefore has been already said, it will appear that the older Drinks are the more healthful, so they be kept up to this Standard, but not beyond it. Some therefore are of Opinion, that strong Beer brewed in _October_ should be Tapp'd at _Midsummer_, and that brewed in _March_ at _Christmas_, as being most agreeable to the Seasons of the Year that follow such Brewings: For then they will both have part of a Summer and Winter to ripen and digest their several Bodies; and 'tis my humble Opinion, that where the Strength of the Beer, the Quantity of Hops, the boiling Fermentation and the Cask are all rightly managed, there Drink may be most excellent, and better at nine Months Age, than at nine Years, for Health and Pleasure of Body. But to be truly certain of the right Time, there should be first an Examination made by Pegging the Vessel to prove if such Drink is fine, the Hop sufficiently rotted, and it be mellow and well tasted. CHAP. XX. _Of the Pleasure and Profit of Private Brewing, and the Charge of buying Malt Liquors_. Here I am to treat of the main Article of shewing the difference between brewing our own Ales and Beers, and buying them, which I doubt not will appear so plain and evident, as to convince any Reader, that many Persons may save well towards half in half, and have their Beer and Ale strong, fine and aged at their own Discretion: A satisfaction that is of no small weight, and the rather since I have now made known a Method of Brewing a Quantity of Malt with a little Copper and a few Tubs, a Secret that has long wanted Publication; for now a Person may Brew in a little Room, and that very safely by keeping his Wort from Foxing, as I have already explained, which by many has been thought impossible heretofore; and this Direction is the more Valuable as there are many Thousands who live in Cities and Towns, that have no more than a few Yards Square of Room to perform a private Brewing in. And as for the trouble, it is easy to account for by those who have time enough on their Hands, and would do nothing else if they had not done this: Or if a Man is paid half a Crown a Day for a Quantity accordingly: Or if a Servant can do this besides his other Work for the same Wages and Charge, I believe the following account will make it appear it is over-ballanc'd considerably, by what such a Person may save in this undertaking, besides the Pleasure of thoroughly knowing the several Ingredients and Cleanliness of the Brewer and Utensils. In several of the Northern Counties of _England_, where they have good Barley, Coak-dryed Malt, and the Drink brewed at Home, there are seldom any bad Ales or Beers, because they have the Knowledge in Brewing so well, that there are hardly any common Brewers amongst them: In the West indeed there are some few, but in the South and East Parts there are many; and now follows the Account, that I have Stated according to my own general Practice, viz. _A Calculation of the Charge and Profit of Brewing six Bushels of Malt for a private Family_. £. s. d. Six Bushels of Malt at 2s. 8d. _per_ Bushel, Barley being this ) Year 1733. sold for 14s. _per_ ) 0 16 0 Quarter by the Farmer ) Hops one Pound 0 1 6 Yeast a Quart 0 0 4 Coals one Bushel, or if Wood or Furze 0 1 0 A Man's Wages a Day 0 2 6 ------------ Total 1 1 4 _Of these six Bushels of Malt I make one Hogshead of Ale and another of Small Beer: But if I was to buy them of some common Brewers, the Charge will be as follows_, viz. £ s. d. One Hogshead of Ale containing 48 ) Gallons, at 6 _d. per_ Gallon is ) 1 4 0 One Hogshead of Small Beer ) containing 54 Gallons, at 2 _d_. ) 0 9 0 _per_ Gallon is ) 0 9 0 ___.____.____ 1 13 0 ___.____.____ Total Saved 0 11 8 By the above Account it plainly appears, that 11 s. and 8 d. is clearly gained in Brewing of six Bushels of Malt at our own House for a private Family, and yet I make the Charge fuller by 2 s. and 6 d. then it will happen with many, whose Conveniency by Servants, &c. may intirely take it off; besides the six Bushels of Grains that are currently sold for Three-pence the Bushel, which will make the Eleven and Eight-pence more by four Shillings, without reckoning any thing for yeast, that in the very cheapest time sells here for Four-pence the Quart, and many times there happens three Quarts from so much Drink; so that there may possibly be gained in all sixteen Shillings and Eight-pence: A fine Sum indeed in so small a Quantity of Malt. But here by course will arise a Question, whether this Ale is as good as that bought of some of the common Brewers at Six-pence a Gallon; I can't say all is; however I can aver this, that the Ale I brew in the Country from six Bushels of Malt for my Family, I think is generally full as good, if not better than any I ever sold at that Price in my _London_ Brewhouse: And if I should say, that where the Malt, Water and Hops are right good, and the Brewer's Skill answerable to them, there might be a Hogshead of as good Ale and another of small Beer made from five Bushels as I desire to use for my Family, or for Harvest Men; It is no more than I have many times experienced, and 'tis the common length I made for that Purpose. And whoever makes use of true Pale and Amber Malts, and pursues the Directions of this Book, I doubt not but will have their Expectation fully answered in this last Quantity, and so save the great Expence of Excise that the common Brewers Drink is always clogg'd with, which is [blotted text] than five Shillings for Ale and Eighteen-pence _per_ Barrel for Small Beer. CHAP. XXI. _A Philosophical Account for Brewing strong_ October _Beer. By an Ingenious Hand_. In Brewing, your Malt ought to be sound and good, and after its making to lye two or more Months in the Heap, to come to such a temper, that the Kernel may readily melt in the washing. The well dressing your Malt, ought to be one chief Care; for unless it be freed from the Tails and Dust, your Drink will not be fine and mellow as when it is clean dressed. The grinding also must be considered according to the high or low drying of the Malt; for if high dryed, then a gross grinding is best, otherwise a smaller may be done; for the Care in grinding consists herein, lest too much of the Husk being ground small should mix with the Liquor, which makes a gross Feces, and consequently your Drink will have too fierce a Fermentation, and by that means make it Acid, or that we call Stale. When your Malt is ground, let it stand in Sacks twenty-four Hours at least, to the end that the Heat in grinding may be allayed, and 'tis conceived by its so standing that the Kernel will dissolve the better. The measure and quantity we allow of Hops and Malt, is five Quarter of Malt to three Hogsheads of Beer, and eighteen Pounds of Hops at least to that Quantity of Malt, and if Malt be pale dryed, then add three or four Pounds of Hops more. The Choice of Liquor for Brewing is of considerable advantage in making good Drink, the softest and cleanest water is to be prererr'd, your harsh water is not to be made use of. You are to boil your first Liquor, adding a Handful or two of Hops to it, then before you strike it over to your Goods or Malt, cool in as much Liquor, as will bring it to a temper not to scald the Malt, for it is a fault not to take the Liquor as high as possible but not to scald. The next Liquors do the same. And indeed all your Liquors ought to be taken as high as may be, that is not to scald. When you let your Wort from your Malt into the Underback, put to it a Handful or two of Hops, 'twill preserve it from that accident which Brewers call Blinking or Foxing. In boiling your Worts, the first Wort boil high or quick; for the quicker the first Wort is boiled, the better it is. The second boil more than the first, and the third or last more than the second. In cooling lay your Worts thin, and let each be well cooled, and Care must be taken in letting them down into the Tun, that you do it leisurely, to the end that as little of the Feces or Sediment which causes the Fermentation to be fierce or mild, for Note, there is in all fermented Liquors, Salt and Sulphur, and to keep these two Bodies in a due Proportion, that the Salt does not exalt itself above the Sulphur, consists a great part of the Art in Brewing. When your Wort is first let into your Tun, put but a little Yeast to it, and let it work by degrees quietly, and if you find it works but moderate, whip in the Yeast two or three times or more, till you find your Drink well fermented, for without a full opening of the Body by fermentation, it will not be perfect fine, nor will it drink clean and light. When you cleanse, do it by a Cock from your Tun, placed six Inches from the Bottom, to the end that most of the Sediment may be left behind, which may be thrown on your Malt to mend your Small Beer. When your Drink is Tunn'd, fill your Vessel full, let it work at the Bung-hole, and have a reserve in a small Cask to fill it up, and don't put any of the Drink which will be under the Yeast after it is work'd over into your Vessels, but put it by itself in another Cask, for it will not be so good as your other in the Cask. This done, you must wait for the finishing of the fermentation, then stop it close, and let it stand till the Spring, for Brewing ought to be done in the Month of _October_, that it may have time to settle and digest all the Winter Season. In the Spring you must unstop your Vent-hole and thereby see whether your Drink doth ferment or not, for as soon as the warm Weather comes, your Drink will have another fermentation, which when it is over, let it be again well stopped and stand till _September_ or longer, and then Peg it; and if you find it pretty fine, the Hop well rotted and of a good pleasant taste for drinking. Then and not before draw out a Gallon of it, put to it two Ounces of Ising-glass cut small and well beaten to melt, stirring it often and whip it with a Wisk till the Ising-glass be melted, then strain it and put it into your Vessel, stirring it well together, stop the Bung slightly, for this will cause a new and small fermentation, when that is over stop it close, leaving only a Vent-hole a little stopp'd, let it stand, and in ten Days or a little more, it will be transparently fine, and you may drink of it out of the Vessel till two parts in three be drawn, then Bottle the rest, which will in a little time come to drink very well. If your Drink in _September_ be well condition'd for taste, but not fine, and you desire to drink it presently, rack it before you put your Ising-glass to it, and then it will fine the better and drink the cleaner. To make Drink fine quickly, I have been told that by separating the Liquor from the Feces, when the Wort is let out of the Tun into the Underback, which may be done in this manner, when you let your Wort into your Underback out of your Tun, catch the Wort in some Tub so long, and so often as you find it run foul, put that so catched on the Malt again, and do so till the Wort run clear into the Underback. This is to me a very good way (where it may be done) for 'tis the Feces which causes the fierce and violent fermentation, and to hinder that in some measure is the way to have fine Drink: Note that the finer you make your Wort, the sooner your Drink will be fine, for I have heard that some Curious in Brewing have caused Flannels to be so placed, that all the Wort may run thro' one or more of them into the Tun before working, by which means the Drink was made very fine and well tasted. _Observations on the foregoing Account_. This Excellent Philosophical Account of Brewing _October_ Beer, has hitherto remained in private Hands as a very great Secret, and was given to a Friend of mine by the Author himself, to whom the World is much obliged, altho' it comes by me; In justice therefore to this ingenious Person, I would here mention his Name, had I leave for so doing; but at present this Intimation must suffice. However, I shall here take notice, that his Caution against using tailed or dusty Malt, which is too commonly sold, is truly worthy of Observation; for these are so far from producing more Ale or Beer, that they absorb and drink part of it up. In Grinding Malts he notifies well to prevent a foul Drink. The quantity he allows is something above thirteen Bushels to the Hogshead which is very sufficient; but this as every body pleases. The Choice of Liquors or Waters for Brewing, he says, is of considerable advantage; and so must every body else that knows their Natures and loves Health, and pleasant Drink: For this purpose, in my Opinion, the Air and Soil is to be regarded where the Brewing is performed; since the Air affects all things it can come at, whether Animal, Vegetable or Mineral, as may be proved from many Instances: In the Marshes of _Kent_ and _Essex_, the Air there is generally so infectious by means of those low vaesy boggy Grounds, that seldom a Person escapes an Ague one time or other, whether Natives or Aliens, and is often fatally known to some of the _Londoners_ and others who merrily and nimbly travel down to the Isles of _Grain_ and _Sheppy_ for a valuable Harvest, but in a Month's time they generally return thro' the Village of _Soorne_ with another Mien. There is also a little _Moor_ in _Hertfordshire_, thro' which a Water runs that frequently gives the _Passant_ Horses that drink of it, the Colick or Gripes, by means of the aluminous sharp Particles of its Earth; Its Air is also so bad, as has obliged several to remove from its Situation for their Healths: The Dominion of the Air is likewise so powerful over Vegetables, that what will grow in one Place won't in another, as is plain from the Beech and Black Cherry Tree, that refuse the Vale of _Ailesbury_ tho' on some Hills there, yet will thrive in the _Chiltern_ or Hilly Country: So the Limes and other Trees about _London_ are all generally black-barked, while those in the Country are most of them of a Silver white. Water is also so far under the Influence of the Air and Soil, as makes many excellent for Brewing when others are as bad. In Rivers, that run thro' boggy Places, the Sullage or Washings of such Soils are generally unwholsome as the nature of such Ground is; and so the Water becomes infected by that and the Effluvia or Vapour that accompanies such Water: So Ponds are surely good or bad, as they are under too much Cover or supply'd by nasty Drains, or as they stand situated or exposed to good and bad Airs. Thus the Well-waters by consequence share in the good or bad Effects of such Soils that they run thorough, and the very Surface of the Earth by which such Waters are strained, is surely endowed with the quality of the Air in which it lies; which brings me to my intended purpose, to prove that Water drawn out of a Chalky, or Fire-stone Well, which is situated under a dry sweet loamy Soil, in a fine pure Air, and that is perfectly soft, must excel most if not all other Well-waters for the purpose in Brewing. The Worts also that are rooted in such an Air, in course partakes of its nitrous Benefits, as being much exposed thereto in the high Backs or Coolers that contain them. In my own Grounds I have Chalks under Clays and Loams; but as the latter is better than the former, so the Water proves more soft and wholsome under one than the other. Hence then may be observed the contrary Quality of those harsh curdling Well-waters that many drink of in their Malt Liquors, without considering their ill Effects, which are justly condemn'd by this able Author as unfit to be made use of in Brewing _October_ Beer. The boiling a few Hops in the first Water is good, but they must be strained thro' a Sieve before the Water is put into the Malt; and to check its Heat with cold Liquor, or to let it stand to cool some time, is a right Method, lest it scalds and locks up the Pores of the Malt, which would then yield a thick Wort to the end of the Brewing and never be good Drink. His putting Hops into the Underback, is an excellent Contrivance to prevent foxing, as I have already hinted. The quick boiling of the Wort is of no less Service, and that the smaller Wort should be boiled longer than the strong is good Judgment, because the stronger the Wort, the sooner the Spirits flie away and the waste of more Consequence; besides if the first Wort was to be boiled too long, it would obtain so thick a Body, as to prevent in great measure its fining hereafter after so soon in the Barrel; while the smaller sort will evaporate its more watry Parts, and thereby be brought into a thicker Confidence, which is perfectly necessary in thin Worts; and in this Article lies so much the Skill of the Brewer, that some will make a longer Length than ordinary from the Goods for Small Beer, to shorten it afterwards in the Copper by Length of boiling, and this way of consuming it is the more natural, because the remaining part will be better Cured. The laying Worts thin is a most necessary Precaution; for this is one way to prevent their running into Cohesions and Foxing, the want of which Knowledge and Care has undoubtedly been the occasion of great Losses in Brewing; for when Worts are tainted in any considerable degree, they will be ropy in time and unfit for the human Body, as being unwholsome as well as unpleasant. So likewise is his _Item_ of great Importance, when he advises to draw the Worts off fine out of the Backs or Coolers, and leave the Feces or Sediments behind, by reason, as he says, they are the cause of those two detested Qualities in Malt Liquors, staleness and foulness, two Properties that ought to imploy the greatest Care in Brewers to prevent; for 'tis certain these Sediments are a Composition of the very worst part of the Malt, Hops and Yeast, and, while they are in the Barrel, will so tincture and impregnate the Drink with their insanous and unpleasant nature, that its Drinkers will be sure to participate thereof more or less as they have lain together a longer or a shorter time. To have then a Malt Drink balsamick and mild, the Worts cannot be run off too fine from the Coolers, nor well fermented too slow, that there may be a Medium kept, in both the Salt and Sulphur that all fermented Malt Drinks abound with, and herein, as he says, lies a great part of the Art of Brewing. He says truly well, that a little Yeast at first should be put to the Wort, that it may quietly work by degrees, and not be violently forc'd into a high Fermentation; for then by course the Salt and Sulphur will be too violently agitated into such an Excess and Disagreement of Parts, that will break their Unity into irregular Commotions, and cause the Drink to be soon stale and harsh. But if it should be too backward and work too moderate, then whipping the Yeast two or three times into it will be of some service to open the Body of the Beer, for as he observes, if Drink has not a due fermentation, it will not be fine, clean, nor light. His advice to draw the Drink out of the Tun by a Cock at such a distance from the bottom is right; because that room will best keep the Feces from being disturb'd as the Drink is drawing off, and leaving them behind; but for putting them afterwards over the Malt for Small Beer, I don't hold it consonant with good Brewing, by reason in this Sediment there are many Particles of the Yeast, that consequently will cause a small Fermentation in the Liquor and Malt, and be a means to spoil rather than make good Small Beer. What he says of filling up the Cask with a reserve of the same Drink, and not with that which has once worked out, is past dispute just and right. And so is what he says of stopping up the Vessel close after the Fermentation is over; but that it is best to Brew all strong Beer in _October_, I must here take leave to dissent from the Tenet, because there is room for several Objections in relation to the sort of Malt and Cellar, which as I have before explained, shall say the less here. As he observes Care should be taken in the Spring to unstop the Vent, lest the warm Weather cause such a Fermentation as may burst the Cask, and also in _September_, that it be first try'd by Pegging if the Drink is fine, well tasted and the Hop rotted; and then if his Way is liked best, bring the rest into a transparent Fineness; for Clearness in Malt Liquors, as I said before, and here repeat it again, is a most agreeable Quality that every Man ought to enjoy for his Health and Pleasure, and therefore he advises for dispatch in this Affair, and to have the Drink very fine, to rack it off before the Ising-glass is put in; but I can't be a Votary for this Practice, as believing the Drink must lose a great deal of its Spirits by such shifting; yet I must chime in with his Notion of putting the Wort so often over the Malt till it comes off fine as I have already taught, which is a Method that has been used many Years in the North of _England_, where they are so curious as to let the Wort lie some time in the Underback to draw it off from the Feces there; nor are they less careful to run it fine out of the Cooler into the Tun, and from that into the Cask; in all which three several Places the Wort and Drink may be had clear and fine, and then there will be no more Sediments than is just necessary to assist and seed the Beer, and preserving its Spirits in a due Temper. But if Persons have Time and Conveniency, and their Inclination leads them to, obtain their Drink in the utmost Fineness, it is an extraordinary good way to use _Hippocrates_ Sleeve or Flannel Bag, which I did in my great Brew-house at _London_ for straining off the Feces that were left in the Backs. As to the Quantity of Malt for Brewing a Hogshead of _October_ Beer, I am of Opinion thirteen Bushels are right, and so are ten, fifteen and twenty, according as People approve of; for near _Litchfield_, I know some have brewed a Hogshead of _October_ Beer from sixteen Bushels of Barley Malt, one of Wheat, one of Beans, one of Pease and one of Oat Malt, besides hanging a Bag of Flower taken out of the last four Malts in the Hogshead for the Drink to feed on, nor can a certain Time Be limited and adjusted for the Tapping of any Drink (notwithstanding what has been affirmed to the contrary) because some Hops will not be rotted so soon as others, and some Drinks will not fine so soon as others; as is evident in the Pale Malt Drinks, that will seldom or never break so soon in the Copper as the Brown sort, nor will they be so soon ripe and fit to Tap as the high dryed Malt Drink will. Therefore what this Gentleman says of trying Drink by first Pegging it before it is Tapp'd, in my Opinion is more just and right than relying on a limited time for Broaching such Beer. 
45339	----	SYKES & STREET, SOLE U. S. AGENTS FOR St. Denis Dyestuff and Chemical Co., (LIMITED.) A. POIRRIER, President. No. 105 RUE LAFAYETTE, PARIS, FRANCE, MANUFACTURERS OF ANILINE COLORS, ARCHIL EXTRACT, CUDBEAR. &c. INCLUDING MANY Specialties for Feather and Silk Dyers French Extracts of Dyewood and Indigo, &c., &c. 85 Water St., NEW YORK, U.S.A. BRANCHES: BOSTON--35 India Street. PHILADELPHIA--43 N. Front St. AGENCIES: R. R. STREET & CO., Chicago. Ills. S. H. FRANK & CO., San Francisco, Cal. [Illustration: GROUP OF OSTRICHES.] THE PRACTICAL OSTRICH FEATHER DYER, BY ALEXANDER PAUL. REVISED AND CORRECTED BY DR. M. FRANK. PUBLISHED BY MRS. DR. M. FRANK, "Textile Colorist," 506 Arch St., Philadelphia, Pa., U. S. A. 1888. _Copyright, 1888, by Mrs. Dr. M. Frank._ _All Rights Reserved._ PREFACE. In the preparation of this work it has been my aim to present Recipes, simple, yet complete in every detail, for dyeing every color and shade of color known. Reliability, practicability and rapidity I claim for this work, and would ask that it be judged not from a literary standpoint, but as a thorough and practical instructor in the art of Ostrich Feather Dyeing, as simplified and perfected by me during years of hard work and research. It is the first work of its kind ever put before the public in the English language, and will, in consequence, receive from those interested close scrutiny and criticism, which prompts the author to offer $1000 to any person who will prove that the recipes herein contained, or any single one of them, will not produce the desired color or shade perfect and in the time mentioned. The old methodical orthodox dyers will find a decided advantage in being enabled to make colors in minutes, that heretofore required hours and days to complete. Technicalities and high-sounding phrases for the names of colors and terms of the dye-house have no place in this work. It is not necessary for a man to be a chemist to be a practical feather dyer, other authorities to the contrary notwithstanding. Good practical common sense and judgment and a knowledge of the nature of the goods you are handling, and throw theory to the winds. ALEX PAUL. TO THE OSTRICH FEATHER MANUFACTURERS, DYERS AND SCOURERS, AND INTERESTED PUBLIC OF AMERICA AND EUROPE, THIS WORK IS RESPECTFULLY DEDICATED, BY THE AUTHOR. _TESTIMONIALS._ The following are a few of the numerous testimonials received by Dr. M. Frank, Manager of "Textile Colorist," in evidence of our method: CHICAGO, Feb. 23, 1885. All I have to say regarding Mr. Alex. Paul's method for dyeing ostrich feathers are just as he represents, and after having taken a course I am perfectly satisfied. I. F. SCHWARZ. RICHMOND, VA., Jan. 20, 1885. Sir,--After receiving a course of instruction of Mr. Alex. Paul, I think he is a thorough master of his art, and fully comes up his promises, and any one who wishes to learn the art could not do better than to engage his services. JAS. F. THURSTON. LOUISVILLE, KY., March 12, 1885. This is to certify that I have this day received instructions from Mr. Paul, in the art of feather dyeing, and I can truly say that I am much pleased with his process, so simple, so quickly done, and produces such beautiful colors and shades. I paid $150 to other parties for instruction in feather dyeing, and I can say that I knew but little about feather dyeing before to-day. P. BARRISTER. MILWAUKEE, Feb. 27, 1885. We take pleasure in recommending the method of feather dyeing taught to us by Mr. Alex. Paul, for the sum of fifty dollars. We think it would be beneficial for any dyer to learn this art. OTTO PIETSCH CO. ROCHESTER, Feb. 4, 1885. This is to certify that Mr. Paul has this day given me instructions in ostrich feather dyeing, for which I paid fifty dollars. I am perfectly satisfied that he has accomplished all that he undertook to do to my satisfaction, and think that it will prove to be money well invested. WM. MAINS. CANTON, O., Feb. 11, 1885. I have taken this day a course of instruction in ostrich feather dyeing from Mr. A. Paul, for which I paid him fifty dollars. The same I consider the most simple and best method known; and is well worth ten times the amount. C. PETER & SON. UTICA, Jan. 31, 1885. I have received a course of instructions from Alex. Paul, for which I paid him fifty dollars, and would state that I consider Mr. Paul a thorough master of the art of feather dyeing, and feel that five times the amount paid him would not be equivalent to the information received. JOHN W. MCLEAN. MILWAUKEE, Feb. 28, 1885. Mr. Alex. Paul has given me instruction for dyeing and cleaning ostrich feathers. I feel satisfied to certify that his method cannot be excelled, and that the instruction is worth ten times the amount charged. I. LEISER. BALTIMORE, Jan. 14, 1885. Sir,--I have received through Mr. Alex. Paul of your method of feather dyeing, and acknowledge that your method is far superior to my most vivid imagination of what can be executed in the art of feather dyeing. I would not sell the information I have obtained, nor would be without it for a great deal more than I paid for it. E. BAUER. ALBANY, Jan. 28, 1885. I am glad to have had the opportunity to learn the art of feather dyeing as taught by Mr. Alex. Paul, and will never regret it. It is the easiest, most economical and the best method known. I paid Mr. Paul fifty dollars for his instruction, but I would not be without it for five hundred. It is, without exception, the finest method extant. JOHN P. MAYER. [Illustration: A, Work-bench. B, Hydro-extractor. C, C, Buckets. D, Boiler. E, Stationary Wash-tub. F, F, Hot-water Pipes.] [Illustration: Steaming Kettle] [Illustration: Curling Knife (Half Size)] OSTRICH FEATHER DYEING. GROWTH OF THE OSTRICH FEATHER TRADE DURING THE PAST TWELVE YEARS IN THIS COUNTRY. The manufacturers of America could have been counted on the fingers of one's hand a dozen years ago. At the present time New York alone can boast of between forty and fifty. Enterprising men in other cities and throughout the country are yearly becoming interested and endeavoring to take hold of this young and profitable business, and we can look to ostrich feather manufacturing at the present time as one of our staple industries. The greatest disadvantage manufacturers have had to contend with was a lack of knowledge of coloring. Our greatest chemists and aniline manufacturers have worked diligently, contributing largely to the progress of wool, cotton and silk dyeing, but the amount of dyestuffs used by the largest feather manufacturers was of such minor importance that it did not seem profitable for them to investigate; consequently the art of ostrich feather dyeing progressed very slowly. Feather dyers a dozen years ago were scarce, and the art (if in those days it could be called such), was controlled to a great extent by the French, who, judging by my experience with them, impressed me as being the most egotistical mortals, and decidedly orthodox in their methods, absolutely refusing to take hold of anything new that might prove beneficial to them, and so jealously did they guard their (as they considered them) secrets, that during working hours every one of them even their employers, were denied admittance to the dye-house. Millions of dollars are at the present time invested in ostrich feathers in all conditions, in the cases of raw stock in the ware-houses and in the flourishing ostrich farms now in existence; and a milliner's window without its rich clusters of ostrich tips and plumes would to-day be a rare sight. They are used not only in the trimming of hats and bonnets, but fashion demands their use in trimming dresses, wraps, etc., and to a large extent they are being used in making handsome and very valuable fans. It is to be regretted that London and Paris markets are supplied with the choicest of the goods that come from the Cape, and America gets the leavings, although our market consumes equally as many, if not more. It is only a matter of time, however, when manufacturers will be importing raw stock direct. THE BIRD, ITS PLUMAGE AND HABITS. Years ago, before the trade had begun to assume its present proportions, the supply of feathers came chiefly from Egypt; the bird being hunted by the natives, and generally killed for its plumage, which was in quality far superior to the feathers which are to-day raised on farms at the Cape. The flues or fibres of the Egyptian were very close and compact and very strong in texture and of great durability, and having a great affinity for color, they were capable of standing a great amount of manipulation without receiving serious injury. A serious objection to them was that one-half, or more, were marked where the bird pecked them with his bill, giving them a moth-eaten appearance, and few of them could be used for white, as they were more or less stained on the ends, a dirty yellow, which soap would not remove and acid would only develop, there being at that time no known method of bleaching them, as the virtues of Peroxide of Hydrogen or Permanganate of Potash as bleaching agents were unknown to the dyers. Enterprising capitalists saw a profitable field for investment in the propagation of the bird, and, as a result, the supply has greatly increased, and the quality of the plumage is far superior in every respect to the wild Egyptian ostrich. A full grown ostrich will weigh about three hundred pounds, and stands about seven to eight feet in height. In the breeding season they will travel in broods of from three to five in number, one of which is invariably a male. The hens lay their eggs in a pit scraped out with their feet, the sand forming a ridge around it. When they have accumulated a dozen eggs or so the male begins to brood, always taking his place on them at night, surrounded by the hens, while by day they will relieve one another. Again, at times the hatching has been left entirely to the sun. North African eggs present a smooth surface, while those of the South are pitted. At the present time an ostrich farm is in progress in California; it is as yet a very young institution, and its success is being watched with interest, but, in my opinion, while the bird will live and thrive, the quality of the plumage will be very inferior to those in their native clime. So much has already been written concerning the bird's powerful digestive organs, and so exaggerated that we will not try to discredit or contradict it. It is hardly necessary to remark that there is scarcely enough substance in ten-penny nails or doorknobs to fatten an ostrich on. BRIEF SKETCH OF DYESTUFFS USED BY ME IN MY METHOD OF DYEING. LOGWOOD. Logwood is met with in commerce in the shape of large blocks, averaging about four hundred pounds each in weight. On the surface the wood is a dirty deep brown red, but within, where it has not come in contact with the atmosphere, its color is much brighter. The tree is a native of South America. It has been known and used ever since a short period after the discovery of America. During the twenty-third year of the reign of Queen Elizabeth an act of Parliament was passed, forbidding its use as a dyestuff, because it did not yield fast colors. This act was repealed, however, by an Order in Council of Charles II., which proceeds to set forth that great improvements have been made as regards the obtaining of fast colors from logwood. The following are the chief varieties of logwood, distinguished by names derived from the localities of exportation: Yucatan, Laguna, Domingo, Monte Christo, Fort Liberte, Jamaica, etc. Logwood is to-day one of our most important dyewoods, as indeed it enters in feather dyeing into all of the dark or staple colors, such as black, navy blue, brown, green, garnet, etc. To extract the substance requires considerable boiling, especially if used in the form of chips; if it is used ground, which is by far preferable to chips in feather dyeing, it requires much less boiling to extract the substance. The dyer will often find logwood, that, although purchased under the name of a most excellent brand, will be far inferior to what he has been using, in which case it is well to look for an adulteration of some sort, which it is not at all easy to detect, only when it does not produce the desired result. TURMERIC. The substance known as turmeric is the under-ground stem of a plant which grows in a wild state in some parts of China and India. It emits a strong, but pleasant odor, and its taste is peppery, aromatic and bitter at the same time. The plant, however, is cultivated in Java and Bengal; the latter country producing the better quality. Although turmeric is rich in coloring matter, its want of permanence is a hindrance to it. It is generally sold in powder, ground down very fine. It should be quite dry; if damp, it loses its color, turns a dull yellowish brown, and dyes flat shades. A good turmeric should show a beautiful lustre. It enters into a majority of the dark colors in feather dyeing, and, although used as a body for colors only, a great deal depends upon it as to the result. BICHROMATE OF POTASH. This dyestuff, known as red chrome and bichromate and often times simply as chrome, consists in one equivalent of potash, with two equivalents of chromic acid. It contains no water, and consequently cannot lose any weight by exposure to heat or dry air. It will not attract moisture from a damp atmosphere. It dissolves readily in ten times its weight of cold water, and is insoluble in alcohol. It forms bright red crystals, and the solution is of a deep orange yellow. Bichromate of potash is a most powerful oxidizing agent, and produces very complex and interesting changes in tinctorial bodies. It is an intense poison. Its most extensive application is now in the production of blacks, along with logwood; indeed, without its aid it would be next to an impossibility to produce a glossy and permanent black on ostrich feathers. In giving depth of shade to all dark colors it is used in preference to any thing else, and I have never found any to contain any adulteration that was perceptible, or that was a hindrance to its good qualities. It is used in ostrich feather dyeing always in a diluted form, in a very high temperature of water. ARCHIL. About the thirteenth century an Italian, Tederigi by name, during travels in the East observed the tinctorial powers of a certain class of plant of low organization, called lichens, and introduced the color into Europe under the name of archil. For this discovery he was amply rewarded by the government, besides amassing a large fortune, as the supply for years came from Florence. At first the weeds were collected on the shores of various islands in the Mediterranean; but on the discovery of the Canary Islands, in 1402, large quantities were obtained from there. Later on they were imported from Cape Verde; and now they are also obtained from Madagascar, Zanzibar, Angelo and Lima and various localities in South America. The weed does not contain any coloring matter already formed, but under the influence of ammonia and the oxygen of the atmosphere gives rise to archil. The manufacture of archil was for centuries carried on in wooden troughs. Two hundred parts lichens were placed in the trough together with about two hundred and forty parts of decomposed urine, and the mixture well worked every three hours for forty-eight hours. Five parts of slaked lime, one part of arsenious acid and one and one-quarter parts of alum were then added, and the whole well stirred and allowed to ferment. The stirring was repeated, from time to time, for a month. The contents of the trough were then removed to casks, and left to stand, thus improving the color. Archil is also one of the most important dyestuffs used by the feather dyer, principally entering into the composition of garnet, plum, brown, etc. Contact with acid will destroy its coloring virtues by turning it a dull brown red. SAFRANINE. It is prepared by treating aniline oils successively with nitrous acid and arsenic acid, and one of an alkaline nitrate at about 212° Fah., for a short time. The product is extracted with boiling water, neutralized with an alkali filtered, and the color precipitated with common salt. Pure hydrochloride forms thin reddish crystals, which are soluble in water and in alcohol, yielding a yellowish red solution. The most characteristic reaction of safranine is that when concentrated sulphuric acid is gradually added to its solution, the color changes to violet, then to blue, dark green and light green. Then, on diluting the solution with water, the same changes of color take place, only in the reverse order. In feather dyeing safranine is used chiefly in making light colors of a pinkish hue; such as pink, terra cotta, and to give a tint to ecru, beige and such colors. OXALIC ACID. Oxalic acid, a most powerful acid, occurs combined chiefly with potash juices of plants of the genus _oxalis_ and _rumex_. Artificially it was obtained by the action of nitric acid upon sugar and starch, but has been prepared latterly by treating spent dyestuffs with alkalies. Oxalic acid forms colorless transparent crystals, which are inodorous, intensely sour, and do not grow moist upon exposure. Should they become damp, some nitric or sulphuric acid, used in the preparation, has not been thoroughly removed. It is soluble in its own weight of boiling water, but requires about eight times its weight of water at 65° Fah. Oxalic is one of the largely used acids in feather dyeing, being used in a number of light colors for the purpose of developing the color. In developing blues it is invaluable. Other colors it will totally destroy, violet or safranine, for example; and it is used in place of sulphuric acid for the purpose of extracting color. INDIGO BLUE. Indigo is derived from several plants of warm climates. In the plant the color exists as a yellowish liquid; but when extracted and exposed to the action of the air it becomes insoluble, and takes an intensely blue color. The cultivation of the plant is carried on chiefly in India, Java, Egypt and Louisiana. Indigo comes in the market in lumps, which, if of good quality, presents a deep bluish purple color, and exhibits a fine reddish coppery lustre if rubbed with a hard, polished body. If very hard or heavy, or when the color is very dull, blackish, greenish or brownish, the quality is below the standard. It is, however, of very little consequence in ostrich feather dyeing, and its impurities would scarcely at any time be noticeable. It should, however, dilute thoroughly in boiling water, and if there remain a sediment of any proportion, the indigo is impure. Sulphuric acid is generally used to develop the color. SULPHURIC ACID. Sulphuric acid, commonly called oil of vitriol, a common, yet very important, acid. Although not used to any great extent in ostrich feather dyeing, it occurs in commerce in various states and degrees of purity. It was at one time prepared by distilling dried copperas at a high temperature. It is now obtained in greater purity from the alkaline bisulphates. It is a clear colorless oily fluid, weighing about eighteen pounds to the gallon. If mixed with cold water, a great increase of temperature takes place. It rapidly destroys organic bodies, depriving them of their oxygen and hydrogen, and leaving the carbon behind, as a blackish mass. If any particle of organic matter falls into a carboy of acid, it is decomposed, and imparts a dark color to the liquid. It takes up water from the air rapidly, if left uncorked, and thus dilutes itself. Its use in feather dyeing is principally to extract colors that are too dark. COPPERAS. Copperas is generally prepared from the soft, white variety of iron pyrites, frequently found to a great extent in the coal measures. These, on exposure to air and moisture, decompose the latter, taking up oxygen, and are thus converted into sulphate of iron. Copperas forms pale greenish blue semi-transparent crystals, containing forty-five per cent. of water. If this be expelled, there remains a dull whitish powder. The crystals dissolve readily in one and one-half times their weight of cold water, and less than half their weight of boiling water. The direct uses of copperas have very much diminished in feather dyeing; as for dyeing black in conjunction with logwood it has been almost entirely superseded by bichromate of potash. In drabs and in saddening down light colors it is, to a certain extent, still used. It is used in quantities so small, however, that there is no serious results to be feared, as it must be used in quantity to injure the fibre. BISMARCK BROWN. Bismarck brown is a product that is used in feather dyeing to a considerable extent, chiefly in a diluted form. It dissolves readily in boiling water. It comes in the form of a powder, of a dirty black hue, and in liquid it is a heavy yellowish red. It makes a fast color, alkali having but little effect on it. Oxalic or sulphuric acid will brighten the color, and turning it more on the red order. In giving a brownish hue to such light colors as beige, ecru, etc., it is invaluable. It is used by some in the topping of dark brown. It has such a great affinity for the fibre of feathers that it is very difficult to remove therefrom. CONCENTRATED COTTON BLUE. This blue appears to the consumer in the form of crystals or coarse powder of a purplish tint. It is not universally used among feather dyers, although it is the most reliable aniline blue in use. It is used in conjunction with oxalic acid to develop. It is fast to light, and possesses a great many advantages of value. It is soluble in water, either hot or cold, and is used in the production of the palest shades, as well as in the darkest navy blues. ROCCELINE. A patented product, that in feather dyeing is capable of taking the place of all other reds. It is the only dyestuff that satisfactorily takes the place of extract of safflower, producing, with the aid of a proportion of oxalic acid, the most beautiful shades of scarlet and cardinal. It is perfectly fast to light, dissolves readily in boiling water, and comes to us in the form of a dull red powder. Its adulterations, if it contains any, have never interfered with its success; in fact, to the feather dyer it contains virtues too manifold and valuable to enumerate. DYEING RECIPES. WHITE. BLEACHING, OR WHAT IS COMMONLY CALLED CLEANING. After stringing your feathers and marking your tickets, prepare luke warm soap-water and wash thoroughly between the hands to remove all dirt and grease. Rub the soap on the feathers, rinse thoroughly in luke warm water two or three times for the purpose of removing all particles of soap, which is very important; just as much so as removing the dirt. For one to one hundred feathers you can use a common porcelain wash bowl. Prepare bath by using one gallon of clear cold water, add to that a small handful of starch, powdered or lump starch will answer. Enter feathers, rubbing them thoroughly between the hands to expand the flues and get them in condition to receive the color, so as to insure an even shade; after which add about one-half teaspoonful of oxalic acid and a drop of diluted violet, just enough to give your bath a pale lavender tint. Enter feathers, and let remain in bath about one minute, keeping them under the surface and agitating by rubbing them between the hands; after which squeeze feathers out of bath and dry. The quickest method for a few feathers is to have a small quantity of clean, powdered starch, and rub them around in it. The starch will immediately absorb all moisture, and you have but to beat it out of the flues, as it dries either on a clean board or between the hands. It is but the work of a few seconds. This method of drying insures an unsoiled color, as the feathers are dry a few seconds after leaving the bath. Great care should be used to bring your violet diluted thoroughly, so that no particles may enter the bath and spot your goods. In diluting your violet use boiling water, and shake well in bottle, and let it stand for a time, when all sediment will settle at the bottom, and will not again mix with your color. It is very important to use only the amount of oxalic acid mentioned in recipe, as a greater quantity would destroy your color by turning the violet a dirty blueish green, and much less than the quantity mentioned would have a tendency to cast a lavender tint on your goods. Should you, by mistake or carelessness, spoil your white, proceed to rinse off all the starch in cold water first; then in luke warm water to remove all the acid from feathers, and then use soap and hot water, and wash well, and rinse. Mix a fresh white bath as directed in the recipe, and proceed this time with more care. BLEACHING LIGHT COLORS WHITE. Old faded light colors, such as blue, pink, ecru, corn, drab, etc., that you are desirous of bleaching white, can be accomplished in the following way. Wash feathers thoroughly in warm water, using soap. Add a small pinch of soda, after which rinse in about three warm waters to insure the removal of every particle of soap. Dilute in clean bowl or basin one-quarter ounce of permanganate of potash in one gallon of boiling water. The water must be as hot as steam or fire can make it. Enter feathers, and let remain in bath about one minute, a few seconds more or less will do no harm, nor will it make any material difference in the result; continually agitating in bath with clean stick, after which you will notice that the feathers have assumed a light, full brown color. Take out of the bath, but do not rinse them; let the loose color drain off for a few seconds, meantime empty bath and rinse your bowl thoroughly; then dilute half an ounce of oxalic acid or sulphurous acid in one gallon of boiling water. The water must be absolutely clean. Enter feathers, and let remain in until all the color has entirely disappeared, gently agitating while in bath. After the bath has become transparent and the feathers white, which will take about two minutes, empty out about two-thirds of the bath, and add cold water to reduce to hand heat; then add a small handful of starch and a drop of diluted violet, and enter your feathers, and let them remain in about one minute, squeeze out and dry in starch. Blue you will generally find the hardest of all light colors to remove for white, the soda and permanganate seeming apparently to decompose the color. The moment it enters the oxalic bath, it generally, to a more or less extent, develops the color again. Such being the case, after rinsing in luke warm water to remove acid, return to a weak soda bath for a minute, and then rinse and return to permanganate bath, rather weaker than the first one; in other words, repeat the first operation all through, only in weaker solutions. This process can be used successfully in bleaching all light colors white. In bleaching natural blacks, however, it would not be practicable. A recipe for bleaching natural black will be found in another portion of the book. [Illustration: WHITE--page 16.] [Illustration: LILAC--page 56.] [Illustration: LIGHT PINK--page 20.] [Illustration: LEMON--page 52.] LIGHT PINK. White feathers are generally used for this color, but all light colors can be made a beautiful shade of pink by first bleaching with permanganate of potash. After washing and rinsing thoroughly in luke warm water, soap to remove all loose dirt and grease, or bleaching, if required. Prepare bath as follows: Take one gallon of luke warm water, more or less, according to the quantity of feathers you have to dye add a small handful of starch. Enter your feathers and rub around between the hands thoroughly to open the flues so as to insure an even shade; add a couple of drops of diluted safranine to bath. Enter feathers, and let them remain in the bath about one minute, or until feathers look about two shades darker than sample; gently stirring them around in bath meanwhile, and keeping them under the surface. Remove from bath, squeeze and dry in the usual way, rubbing them in dry powdered starch, and beat them out on a clean board or between the hands to remove all particles which might adhere. Should your sample that you have to match be a little on the yellowish order, a drop of diluted Bismarck brown added to bath will bring the desired shade; or if a very brilliant shade or rose pink, a drop of diluted violet added to the bath and increase temperature; a little judgment is always necessary; as, for example, should you require a dark shade, you would naturally let your goods remain longer in the bath than the time specified in recipe, or add a little more color, and if a very pale pink is wanted, less time and color should be used. Should you, at any time, find your color, after being dried, a couple of shades darker than your sample, rinse goods in luke warm water, and enter feathers, pass through for a minute, and dry. LIGHT BLUE. All other faded out light colors can be made into a delicate shade of sky blue by first bleaching with permanganate of potash process for the purpose of removing colors. White feathers that are only dirty and greasy must be thoroughly washed and rinsed in luke warm water, after which prepare bath as follows: For one gallon of luke warm water, more or less, according to the amount of feathers to be dyed, add a small handful of clean starch; enter your feather and rub them around in bath for a second between the hands to open the flues, to admit color evenly; add about one teaspoonful of oxalic acid, enter feathers and let remain in bath a few seconds longer; then remove feathers from bath, and add a couple of drops of concentrated cotton blue diluted; re-enter feathers and let them remain in about half a minute; increase temperature of your bath a few degrees by adding some hot water; take feathers out of bath and add thereto a drop of diluted indigo blue; re-enter, and keep them well under the surface of bath to give them an even color, and allow to remain in about thirty seconds longer. Take them out of bath, squeeze out and dry, either in powdered starch or by beating on a clean board or table. Under no circumstances allow feathers to hang wet and motionless on line during process of drying without beating the starch out. The result of so doing would cause the feathers to look thin, shriveled, and injure the color and quality of goods. The same care should be observed not alone in this, but in all colors. In light blues your bath should look about two shades darker than the sample to be matched. Where a darker shade is required, more color can be added; and, through carelessness or negligence, should you allow your color to become too dark, rinse off your feathers in cold water first to remove the starch, and then in luke warm water a couple of times to draw off all acid, and pass feathers a few seconds through a bath of luke warm water with a small pinch of soda in it, which will have the effect of drawing off all surplus color; after which rinse in luke warm water, and mix a fresh bath of luke warm water and starch and one-half a teaspoonful of oxalic acid; enter your feathers and carefully add color until you have obtained the desired shade. ECRU. All old colors, excepting dark brown, bottle green, navy blue, black, garnet, etc., can be dyed a good shade of ecru. Begin an old color by passing them through a solution of hot water, about one ounce of soda to a gallon of water, for about 30 seconds; after which take them out and rinse by passing them through clean boiling water, which will draw off more color than it would seem possible the feathers could contain. If all the old color, or enough of it, be not removed, put feathers through the permanganate of potash process. For dirty white feathers simply wash them thoroughly with soap and hot water, and rinse well; then prepare your bath as follows: One gallon of hand warm water, add a small handful of starch, and enter feathers, rubbing them around thoroughly, and getting the starch rubbed into the flues; then add to bath a small quantity of copperas, about the size of a bean, and re-enter your feathers and let remain in bath about one minute or less; after which add a few drops of logwood liquor and about a teaspoonful of diluted aniline brown, first removing feathers from bath; enter feathers and let remain in bath about one minute, being careful to keep them moving in bath. If found a little too brown to match your sample, a small pinch of turmeric added to bath will reduce the shade. If they are found a little too yellow for sample, a drop of diluted violet will answer. If the dyer, through his own carelessness, should allow his color to get too dark, proceed to extract color as follows: dilute in about one gallon of luke warm water one-half teaspoonful of oxalic acid. Enter feathers, first rinsing off starch in cold water; let them remain in about half a minute, and rinse off about three times in hot water to remove acid. The acid will turn the feathers a bright yellow, and after rinsing off well the yellow color will have entirely disappeared, and the feathers a light shade of dust. Prepare a fresh bath as per recipe, and, using more care, enter feathers and pass through until you have acquired the desired shade. In the first bath, should a very dark shade be required, add a little more logwood and copperas than directed in the recipe, and if a very light color, a little less. CREAM COLOR. There are numerous methods of producing this most beautiful, yet simple, shade. Any yellow substance in conjunction with oxalic acid can be used with more or less fair success. A great many dyers use a few drops of diluted logwood, developed with the aid of oxalic acid. The color this produces is very satisfactory when finished, but no sooner is it exposed to strong light than the color becomes a dirty drab shade, caused by the acid leaving the feathers, the logwood becoming oxidized. The best and most permanent shade of cream color is obtained in the following manner: Thoroughly wash and rinse your feathers to remove every particle of dirt, for it is as necessary to have the feathers clean as if they were for a white, and if they are very dirty or old faded out colors, put them through the permanganate of potash process, and then remove all color. Prepare bath of one gallon of luke warm water and a small handful of starch; enter feathers and rub around in bath between the hands; meantime dilute in about one pint of boiling water a small five-cent package of essence of coffee (commonly called chicory), and boil for a few minutes; then add a few drops of the liquid to the bath, and add thereto a teaspoonful of oxalic acid. Re-enter feathers and let remain in bath about one minute, constantly moving them around; after which squeeze them out and dry, either in starch or on a clean board. The result will be a rich and permanent cream. Should a pink or brownish tint be required to match sample, a drop of Bismarck brown added to bath will produce the desired result; or if wanted a little more yellow, a few grains of turmeric added to the bath will answer. [Illustration: CREAM--page 25.] [Illustration: LIGHT BLUE--page 21.] [Illustration: LAVENDER--page 38.] [Illustration: SALMON--page 71.] SILVER GRAY. A very delicate color, requiring feathers almost a pure white to make a clear shade. After thoroughly washing and rinsing, or bleaching if required, with permanganate of potash, prepare a bath of one gallon of luke warm water, and add a small handful of starch. Enter feathers and manipulate between the hands; then add to bath a small piece of copperas, about the size of a pea, and a few drops of diluted logwood liquor; re-enter feathers and let remain in bath until in appearances they are two or three shades darker than sample; then add to bath a couple of drops of diluted violet, first removing feathers from bath; let them remain in a few seconds longer, and squeeze out and dry in the usual way. The violet gives your feathers the brilliant shade that is so desirable in silver grays. Be careful in drying them not to use starch that has been previously used in drying feathers that have been dyed in acid baths, as it would be liable to spot your color. Should you, through carelessness or otherwise, allow your color to get darker than shade desired, rinse feathers off a couple of times in cold water to remove starch; then dilute half a teaspoonful of oxalic acid in a gallon of hot water, and pass feathers through it for a few seconds, and then rinse off twice in boiling water. After which prepare a bath same as per recipe, using more care, and pass feathers through until you have obtained the desired shade. BISMARCK BROWN. Wash and rinse your feathers, after which prepare a bath of one gallon of boiling water and about one ounce of turmeric and half an ounce of copperas; enter your feathers and let them remain in bath about two minutes, more or less, after which take out and rinse twice in cold water. Meantime have boiling a bath of half a pound of logwood to a gallon of water, and enter feathers at boiling temperature, letting them remain in about ten seconds or longer. Should a darker shade be desired, take out and rinse in cold water, after which dilute a half teaspoonful of aniline brown in a gallon of boiling water. Reduce temperature a little with cold water. Enter feathers and let them remain in about three minutes; then cool off a small portion of the bath, and add a small handful of starch, pass feathers through and dry. If a lighter shade is wanted, add a drop of sulphuric acid to the starch bath and pass feathers through. If the sample to match be more on the yellow order, about twice the amount of turmeric in the first bath; and if desired more on the red, use no turmeric, only copperas, in the first bath. If a darker shade is wanted, let them remain a longer time than that specified in the logwood bath. Any light color can be used to make a Bismarck brown; but if very dark colors are used, it is well to draw off some of the color, doing it in the usual way. [Illustration: SEA-FOAM--page 70.] [Illustration: SILVER GRAY--page 26.] [Illustration: ECRU--page 23.] [Illustration: TRILEUL--page 58.] SEAL BROWN. For seal brown it is not necessary to wash your feathers, nor to bleach off any color. Any old colors, excepting black, can be made a good shade of seal brown. Begin in bath by diluting about two ounces of turmeric in a gallon of boiling water (more or less matters not). Enter your feathers and keep them well under the surface of the bath about two or three minutes; after which take out and rinse in cold water twice. In the meantime boiling a bath of logwood about one pound to a gallon of water. If boiled on fire about fifteen minutes is necessary, and if boiled with steam a half hour is required. Enter feathers in logwood and let remain in about three minutes, keeping them well under the surface of bath, after which take out and rinse; if in cold water about twice, then dilute a half an ounce of bichromate of potash in a gallon of boiling water, and see that bichromate is thoroughly dissolved. Enter feathers and let them remain in about ten seconds, a longer time if a very dark shade is wanted; then take them out and rinse thoroughly in cold water; after which add to your logwood bath about one tablespoonful of extract of archil; bring bath to a boil and enter your feathers; cover up bath and let them remain in about four minutes; a little more or less time, in this bath is of no material difference in color, only to make the shade heavier or lighter. Take your feathers out of bath and rinse in cold water; mix a small handful of starch in about a quart of cold water, and pass feathers through and dry in the usual way. If your color be darker than the shade you desire, add a drop or two of sulphuric acid to starch bath, and pass your feathers through for a few seconds. If found to be lighter than the shade you desire, rinse off the starch from your feathers in cold water; then dilute a quarter of an ounce of bichromate of potash in a gallon of boiling water, and pass your feathers through; after which rinse, starch and dry. Another excellent method for quick seal brown is as follows: dilute two ounces of turmeric and half an ounce of copperas in one gallon of boiling water, and let them remain in about two minutes; take out and rinse, then enter in a strong bath of logwood at boiling, and keep under surface about three minutes; after which rinse; then mix a bath of a quarter to a half teaspoonful of aniline brown in a gallon of boiling water. Enter your feathers and let them remain in bath about three minutes; take out, rinse, starch and dry. If required darker, re-enter into logwood bath for a few seconds. If wanted lighter, add a drop or two of sulphuric acid in your starch bath, squeeze out and dry in the usual way. NAVY BLUE. All light colored feathers can be used for navy blue without first either washing or bleaching out any of the color. But if your feathers be very dirty or greasy, especially the latter, wash them well in warm soap water and rinse. Prepare bath by diluting about one teaspoonful of concentrated cotton blue in one gallon of boiling water; add about a teaspoonful of oxalic acid. Stir around well to thoroughly dissolve aniline; then enter your feathers, and raise temperature of your bath to boiling. Let feathers remain in about three minutes; a minute more will not do any harm, only have a tendency to make your color a little richer; after which take feathers out of bath and rinse thoroughly in cold water for the purpose of removing all loose particles of color and the acid; having boiling meantime a bath of logwood of medium strength; enter feathers, letting them remain therein about one-half a minute; take out and rinse in cold water; dilute about half an ounce of bichromate of potash in a gallon of boiling water; enter feathers, let them remain in about half a minute, and stir them around well in bath; after which take them out and rinse in cold water and starch and dry. Should you desire a darker shade, rinse off starch, and return to logwood bath for a few seconds, rinse off and repeat bichromate of potash bath; then rinse, starch and dry. In this way, by repeating the logwood and bichromate of potash, you can darken your color down almost to a black. Should you get your color darker than your sample to be matched, rinse off starch in clear cold water, and dilute a teaspoonful of oxalic acid in a gallon of hot water almost boiling and enter feathers, passing them through about a half minute; after which take out and pass through a basin of boiling water a few seconds. This will draw off the surplus of logwood and chrome, and then mix a starch bath luke warm; add thereto a half teaspoonful of oxalic acid for the purpose of bringing up the blue. This process will reduce your color three or four shades; then pass feathers and dry. This process of dyeing navy blue produces a rich, even shade that is perfectly fast to light and alkali, and with the smallest degree of judgment by the dyer it is impossible to have a failure. CARDINAL. Years ago the most successful shades of cardinal were produced by taking about equal parts of turmeric and oxalic acid and diluting in boiling water, entering feathers in same for a while; then adding thereto about half a cupful of extract of safflower and about the same amount of extract of archil, letting them remain in until the bath was cold. Not a bad recipe, but very expensive. Prepare your feathers by washing and rinsing thoroughly, after which take about one gallon of boiling water, and add to it about one teaspoonful of oxalic acid, and enter feathers for a few seconds. Take out and add to bath a teaspoonful of rocceline powder, thoroughly dissolved, and re-enter feathers; raise temperature of bath to boiling, either with steam or fire, and let feathers remain in about four minutes. If quite a dark shade of cardinal be required, add to bath about a tablespoonful of extract of archil and let remain in a little longer, or a few drops of diluted violet in bath will answer instead. Then empty out all but a small quantity of your bath and cool off with cold water, and add a small handful of starch. Pass feathers through, squeeze out and dry. The result is a most beautiful shade of cardinal. This color is perfectly fast to light. If your shade to match should happen to be slightly on the yellowish order, a few drops of diluted aniline brown added to bath with rocceline will produce the yellowish tint. It is hardly possible to spoil this color, except by the extravagant use of one of the ingredients. [Illustration: CHOCOLATE--page 75.] [Illustration: CORN--page 64.] [Illustration: MEDIUM BLUE--page 67.] [Illustration: BEIGE] CRUSHED STRAWBERRY. Prepare feathers by washing and rinsing thoroughly in luke warm water; or if old, dark, faded out colors, pass them through bleaching process of permanganate of potash; afterwards being careful to rinse all the acid out before entering bath. Prepare bath by diluting a small handful of starch in about a gallon of luke warm water, enter feathers and manipulate thoroughly between the hands for a few seconds; take out, and add to bath a few drops of diluted safranine; re-enter feathers and let remain in bath about one minute, or until they have assumed a dark shade of pink; then add to bath a few drops of diluted aniline brown and a small pinch of copperas, and enter feathers, letting them remain a minute longer. Take feathers out, and dry in the usual way. If a very dark shade is wanted, a few drops of diluted logwood added to bath at the time you add the copperas will have the desired effect; or a few drops of violet will answer in its stead. Should you find your color too much on the drab, a few drops of safranine added to bath will have the desired effect. Should you find that your color is entirely too dark for your sample, rinse off the starch in cold water; pass feathers through a solution of a half teaspoonful of oxalic acid in a gallon of hot water for a few seconds; then rinse in hot water twice to remove the acid, after which prepare a fresh bath as per recipe, using more care, and keep in until desired result is obtained. PLUM. Feathers that are any color excepting dark green or black can be dyed a beautiful shade of plum. Wash and rinse your goods, and prepare your bath as follows: one pound of logwood to a gallon or more of water, and boil fifteen minutes or longer, then add to bath about a quarter pound of extract of archil, and enter your feathers, letting them remain in bath about five minutes, after which take them out and rinse in cold water. Prepare a bath of half an ounce of bichromate of potash in a gallon of boiling water, more or less, and see that it is thoroughly dissolved; pass feathers through about ten seconds; then take them out and rinse twice in clear cold water; then dilute a small handful of starch in a half gallon of luke warm water, and add to it about half an ounce of soda; pass feathers through for about half a minute and dry. Should color be found too light for sample, rinse off starch in cold water, and repeat bichromate of potash bath; rinse, starch and dry. An old logwood bath that has been used for other colors will answer for plum, and save boiling up a fresh bath. OLIVE. If your feathers to be dyed are very dark colors, such as brown, navy blue, green, garnet, etc., draw off some of the color by passing through a solution of boiling water and half an ounce of soda, and rinse in boiling water twice. Prepare bath by diluting two ounces of turmeric in about one gallon of water. Enter feathers and let them remain in about two minutes,--a longer time will not hurt; after which take them out and rinse in cold water twice. Have a medium strong bath of logwood boiling meantime, and enter your feathers, letting them remain in about two minutes; then take them out and rinse in cold water. Prepare a bath of one gallon of boiling water and half an ounce of bichromate of potash, and after it is thoroughly dissolved, enter your feathers and let them remain in about one minute, longer if a very dark shade be required. Take out and rinse, after which your feathers will have assumed a dark, dull olive, looking not unlike a faded out black. Next prepare a bath of two ounces of turmeric with about one gallon of boiling water, and add thereto a small pinch of green aniline, just enough to give your bath the appearance of being a couple of shades more on the green than the sample to be matched. Enter your feathers and let them remain in about three minutes; first, however, bringing your bath to a boil, after which take feathers out and rinse, starch and dry. If feathers be found darker than sample to be matched, a few drops of diluted oxalic acid in your starch bath will bring the shade down; and if found lighter than sample, rinse the starch off thoroughly in cold water, and dilute a quarter ounce of bichromate of potash in a gallon of boiling water, and pass your feathers through for a few seconds. If wanted a very dark shade, they should, after having the starch rinsed off, be returned to the logwood bath, then rinsed and give the bichromate of potash bath as above. If found a little too much on the green for sample, a weak bath of turmeric, similar to the first bath of the operation will have the desired effect. There are also some shades of olive where it will not be found necessary to use any green at all; that is when the shade approaches the brown on the olive. LAVENDER. Feathers for lavender must be white, or nearly so, if you desire a good clear shade. All light colors can be used by first bleaching with permanganate of potash, or if only dirty white feathers, wash and rinse them thoroughly. Prepare bath of luke warm water and a small handful of starch, rub feathers around between the hands to expand the fibres; then add to bath a few drops of diluted violet. Enter your feathers and let remain about one minute in bath, keeping them meanwhile in motion; take out your feathers and add to bath a drop of diluted safranine; re-enter and raise temperature of bath a few degrees by addition of hot water; let your feathers remain about half a minute in bath; if wanted darker, add a few drops of diluted violet, and if lighter, less; after which take out your feathers and dry them in the usual way, being careful to use clean starch for drying. To use starch that had previously been used to dry light colors that contained acid, would most likely result in spotting your color, as the application of acid to any portion of the delicate color would turn it a greenish blue. If your color be found too dark for sample, you can either wash in a solution of soap water, or else pass feathers through a bath of a teaspoonful of oxalic acid to a gallon of luke warm water, after which rinse off well and put through fresh bath as per recipe. OLD GOLD. All light colors, such as light blues, pinks, drabs, yellows, etc., that you are desirous of making old gold need but to be washed with soap and hot water prior to entering in bath. Prepare your bath with two ounces of turmeric and one gallon of boiling water, more or less matters not. Enter your feathers, and let them remain in bath about two minutes, after which add a small pinch of copperas, about the size of a bean. Let your feathers remain in bath about one minute longer, after which take feathers from bath and add thereto a few drops of diluted Bismarck brown; let them remain in bath about one minute longer; take them out, cool off a small portion of the bath with cold water, add a small handful of starch, pass your feathers through and dry. If wanted a very dark shade of gold, a few drops of diluted logwood added to bath will have the desired effect; and if wanted lighter, a smaller quantity of copperas in bath. If the shade be found entirely too dark for sample, a solution of oxalic acid in luke warm water will draw off a portion of the color and brighten what is left. If wanted a very yellowish shade of gold, use more turmeric, less copperas and no logwood, and be particular to have your bath at all times at a boiling temperature. [Illustration: SLATE--page 47.] [Illustration: GENDARME BLUE--page 57.] [Illustration: FELT DRAB--page 46.] [Illustration: GARNET--page 40.] GARNET. It is not necessary to wash your feathers, except they are very dirty and greasy. As a rule all old colors, excepting greens, navy blues or blacks, can be used for this color without bleaching. Prepare bath by boiling about one pound of logwood to a gallon of water or more about fifteen minutes; strain off liquor from wood; add about two tablespoonfuls of extract of archil, and bring again to a boil. Enter your feathers and let them remain in bath about four or five minutes, after which take feathers from bath, rinse twice in clean cold water, and dilute a small handful of starch in a little clear cold water; pass feathers through and dry in the usual way. Should your color be found too dark for sample to be matched, dilute a couple of drops of sulphuric acid in your starch bath, and pass feathers through for a few seconds; first, however, adding a little hot water to increase temperature. If found lighter than the desired shade, rinse your feathers thoroughly in cold water and dilute half an ounce of bichromate of potash in about one gallon of boiling water; pass your feathers through for a few seconds, rinse thoroughly and dry. Great care is necessary in passing feathers through this chrome bath, as the color will oxidize very rapidly. If your sample to match be more on the brown shade, a very little archil, not more than one-half the prescribed quantity must be used; and if more on the purple or plum, add more archil than the quantity specified. In preparing bath, when you have added the archil, be careful in bringing it to boiling temperature that you do not allow it to boil any time, as that would have a tendency to dull your color. By keeping this bath clean it can be used several times, in fact, it improves with age; and, if kept in a crock, so that it will not come in contact with any metallic substance, and when needed just brought to boiling temperature; and if needed, a teaspoonful of archil added to it will produce very beautiful shades of garnet. This bath can be used to make your plum colors; and if you have an old bath of logwood on hand it is not necessary to boil a fresh one, simply add the archil, and bring to a boil. TERRA COTTA. If white feathers, wash and rinse them thoroughly with hot water, and if faded out light colors, extract color by bleaching with permanganate of potash in the usual way; being careful to rinse well in hot water to remove all the acid used in bleaching before entering bath. Prepare bath as follows: about a gallon of luke warm water, and add a small handful of starch. Enter feathers, rub around in bath between the hands, take out and add a few drops of diluted safranine, and copperas about the size of a pea. Enter feathers and let remain in bath about one minute; take out and add about half a teaspoonful of diluted aniline brown; re-enter feathers and let them remain in about half a minute longer; after which dry in the usual way. If found too pink for sample, add a few drops more aniline brown, and return to bath for a few seconds. If found too yellow, add a few drops more of diluted safranine, and keep in bath a few seconds longer; if wanted darker, add a little more of each color, and keep in bath longer. BOTTLE GREEN. After washing and rinsing feathers thoroughly,--if dirty or greasy, extracting color if necessary,--prepare bath as follows: One ounce of turmeric diluted in one gallon of boiling water; enter your feathers and let remain in about one minute, after which take out and rinse thoroughly. Prepare a weak bath of logwood, about half a pound to the gallon of water, or about half the usual strength of an ordinary logwood bath for black; boil a few minutes, after which enter your feathers and let them remain in bath about one minute; then take out and rinse thoroughly in cold water; after which prepare a bath of half an ounce of bichromate of potash to one gallon of boiling water. Dissolve bichromate of potash, enter feathers and let them remain in about half a minute; a little longer if a very dark shade be required, and so much less time if a very light shade is required; after which take feathers out and rinse thoroughly in cold water. Dilute about one-half a teaspoonful of aniline green in a gallon of boiling water, and reduce temperature of bath a few degrees with cold water; then enter feathers and let them remain in bath about two or three minutes; remove feathers and cool off a small portion of the bath with cold water, and add to it a small handful of starch; pass your feathers through the bath, squeeze out and dry off in the usual way. If found to be lighter than shade desired, rinse off starch thoroughly, and return for a few seconds to logwood bath without increasing temperature any; then rinse off in cold water, and pass through a weak solution of bichromate of potash, about one-quarter ounce to a gallon; after which rinse, starch and dry. If found darker than shade desired, pass feathers through a solution of half a teaspoonful of oxalic acid in about one gallon of luke warm water for about thirty seconds; take them out of this and rinse twice through boiling water, and then give a weak bath of aniline green,--about half the strength of the first bath. If samples to be matched be more on the yellow or olive, use decidedly more turmeric in the first bath, and add a little, say about a teaspoonful, to the aniline green bath. If a green on the blue, it will be necessary to use only one-half the turmeric prescribed in the first bath. STEEL COLOR. All light colors can be used to make a good shade of steel by first extracting colors by the usual process of bleaching with permanganate of potash; if white and dirty, wash thoroughly in hot water and soap and rinse. Prepare your bath as follows: To one gallon of luke warm water add a small handful of starch; enter your feathers, rub them around well in bath; after which add a small pinch of copperas and about a tablespoonful of logwood liquor, and let remain in about one minute; increase temperature of bath and add a few drops of diluted violet, first removing your feathers from bath; re-enter feathers and let remain about one minute, or until your feathers look about four shades darker than sample; after which take out and dry. If found too light, return to bath and add more logwood liquor and a few drops more violet, and should you find them altogether too dark for sample, extract your color by passing them through a solution of one teaspoonful of oxalic acid in a gallon of hot water; after which rinse them off by passing them through a gallon of boiling water about twice, when you will find your color reduced four or five shades. The oxalic acid renders the feathers a bright yellow. Boiling water will draw off the logwood and bring out your shade of drab in as much milder form; then proceed to mix a new drab bath the same as per recipe, only using more caution not to get it too dark; enter feathers, bring to shade, using a drop of violet to brighten up color. Be careful in drying not to use starch that has previously been used on a color where acid was used to develop. [Illustration: STEEL--page 45.] [Illustration: ARMY BLUE--page 59.] [Illustration: PURPLE--page 60.] [Illustration: MAROON--page 51.] FELT DRAB. Prepare feathers by washing and rinsing thoroughly, or bleaching if needed; after which mix a bath of luke warm water and starch. Enter feathers and manipulate in bath a few seconds between the hands; after which add a small quantity of copperas, about the size of a pea. Enter feathers and let them remain in about half a minute; take out feathers and add a few drops of logwood liquor; re-enter feathers and let them remain in about half a minute; add to bath about a drop of diluted safranine, and if shade be wanted a little on the yellow, a drop of diluted Bismarck brown can be added. Allow feathers to remain in until they look about three shades darker than sample; then take out and dry as usual. If found either too dark or too light, treat precisely as preceding color (steel). Be careful not to use starch that has been used for an acid color. SLATE COLOR. To make this color all light colors can be used and some dark ones; only those, however, that do not contain much yellow, as, for example, blues, reds, etc. After preparing for bath by washing and rinsing, or by extracting color if necessary, mix a bath of logwood, about half the usual strength, and enter feathers. Bath must be at boiling temperature, and let them remain in about one minute; after which take out and rinse. Proceed to mix a bath of one quarter ounce of copperas and one gallon of boiling water; enter feathers and let them remain in bath about half a minute; take out and cool off a small portion of the bath, add starch and pass feathers through, squeeze out and dry. If the color to be matched be very dark, repeat the bath of logwood and mix a bath of one-quarter ounce of bichromate of potash in a gallon of boiling water. Enter feathers and let remain in about half a minute; after which rinse off in cold water, and starch and dry. If a very brilliant shade be required, when you have rinsed feathers from bichromate of potash bath, wash thoroughly in soap-suds and rinse in luke warm water. Dilute a small quantity of starch in cold water, pass feathers through and dry. The above recipe produces a most beautiful shade of slate color, perfectly fast to light, and the depth of shade is regulated by the quantity of logwood. Should you find your color altogether too dark for sample, proceed to extract by passing through a solution of one teaspoonful of oxalic acid to one gallon of boiling water for about half a minute, and then rinsing off twice or three times in boiling water; after which repeat in a milder form. ORANGE COLOR. Prepare feathers by washing and rinsing thoroughly. Prepare bath by diluting about two ounces of turmeric in a gallon of boiling water, and enter your feathers, letting them remain in bath about two minutes; then take them out and add a few drops of diluted Bismarck brown and about a teaspoonful of oxalic acid; re-enter your feathers and bring bath to a boil, and let remain in about three minutes; after which take out, and cool off a small quantity of bath, add a small handful of starch, pass feathers through and dry. Should you desire a very full dark shade, use about twice the amount of turmeric, add a few drops more Bismarck brown; and if wanted much lighter, use less of each color. If wanted more yellow, use very small quantity of Bismarck brown; and if a very reddish shade of orange, a little more Bismarck brown than amount prescribed in recipe. There are numerous orange anilines in the market that are used successfully in dyeing shades of orange, but it is almost necessary to have a different shade of aniline for every shade of color made. Should your sample to be matched be rather dull, use no oxalic acid in bath, as the oxalic acid is used in developing and brightening the shade. To remove the color, should it be too dark, the first method is to wash well in soap water, rinse and pass through a solution of oxalic acid in warm water, about half an ounce to the gallon. SCARLET. Wash and rinse your feathers thoroughly, and if required to remove a surplus of any old color, pass through a bath of permanganate of potash, as per recipe; after which prepare a bath of half a teaspoonful of oxalic acid to one gallon of boiling water and about a teaspoonful of turmeric; enter feathers and let them remain in bath about half a minute, after which take them out and add to bath about half a teaspoonful of rocceline; dissolve powder thoroughly, and return to bath; let them remain in about one minute longer, then cool off a small quantity of the bath and add a small handful of starch; pass your feathers through, squeeze out and dry as usual. If wanted a very dark shade, add a little more rocceline and let remain longer in bath. If shade be a little on the orange, use more turmeric and less rocceline; and if more on the cardinal, vice versa. Should you, through carelessness, get your color too dark, to remove color rinse off and wash thoroughly in a soap bath, and rinse off in boiling water about twice, which will have the effect of reducing the color several shades; mix a new bath as per recipe, and enter feathers, using more care and judgment and proceed to starch and dry as called for in recipe. MAROON. Almost any odd shades of color can be used without extracting colors, but if dirty or greasy, it is always best to wash thoroughly and rinse. Take your old logwood bath that has been used for black and other colors, or else boil a fresh bath of the same proportions, about a pound to the gallon. When at boiling temperature add thereto a half cupful of extract of archil, first removing the grounds of logwood from the bath; then enter your feathers and let them remain in the bath about four or five minutes; take them out and rinse thoroughly in cold water, and prepare a bath of one-half ounce of bichromate of potash to a gallon of boiling water, and thoroughly dissolve potash; after which pass your goods through for a few seconds only, and take out and rinse twice in cold water; dilute a small handful of starch in clean cold water, pass feathers through and dry. Should a very dark shade be required, allow your feathers to remain in bichromate of potash bath a few seconds longer; take out and dry. Should you find your color too dark for sample, it is only necessary to add to your starch bath a few drops of sulphuric acid, and add a small quantity of hot water to increase temperature a few degrees, and pass feathers through. This bath, same as the garnet, can be used again, and improves with age if kept in a clean place. If you have an old garnet bath on hand, it will answer for maroon by bringing to a boil and adding about a teaspoonful more extract of archil to it. [Illustration: STONE--page 73.] [Illustration: COFFEE--page 79.] [Illustration: BOTTLE GREEN--page 43.] [Illustration: OLIVE BROWN--page 81.] LEMON COLOR. Wash and rinse your feathers thoroughly if dirty whites; if old faded out light colors, bleach with permanganate of potash; after which prepare bath as follows: One gallon of luke warm water and a handful of starch; enter your feathers and rub around between the hands for a few seconds; then add to bath a teaspoonful of oxalic acid, and dilute about a tablespoonful of turmeric in a small quantity of water, and add a few drops of the liquor to the bath; re-enter your feathers and let them remain in about one minute or so; after which take them out and add a drop of diluted indigo blue; return feathers to bath and allow them to remain about one minute longer in bath, after which take out, squeeze and dry usual. If a deep rich shade be desired, and you have no sample to match, use no indigo in the bath. Another excellent method of making lemon is to substitute an equal amount of picric acid for turmeric; and, should you find your color entirely too dark for your sample, rinse off your feathers in luke warm water, and proceed to wash with soap and hot water, and rinse thoroughly in boiling water; then prepare a fresh bath as per recipe, and enter your feathers, using much care. If found too light for your sample, add to bath a little more turmeric liquor, and return feathers to bath for a few seconds longer, and dry. BLACK. The most staple and important of all the colors. Some will argue that it is not a color; I, to the contrary, however, that it is not only a color, but a combination of colors, and it is the knowledge of how to properly combine them that results in the production of a very handsome and glossy black. Twelve years ago a bath of black that was commenced on Monday and was ready to go into the drying-room by Saturday was considered at that time a most expeditious piece of work; and, even up to the present time, some of our old orthodox dyers,--those old chronic, methodical dyers,--those who dye according to the most approved and advantageous methods of half a century ago,--still continue to occupy the greater part of a week in getting a black on what (by that time) is left of the feathers. Their object from the start is to produce a black, and they generally succeed. Begin, if raw stock, by washing and rinsing thoroughly in order to remove all natural grease and dirt adhering to the fibre. If they are old colors to be redyed a black, it is not necessary to wash them nor to bleach them for the purpose of removing any of the color, as the black bath will overcome all the other colors; as, for example, a navy blue, a bottle green, garnet, etc., can be all entered at the same time, and put through precisely the same process, and they will all be the same shade of black when they are dried. Prepare bath by diluting a quarter pound of turmeric in a gallon of boiling water and bring to a boil; after which enter your feathers, and let remain in bath about five minutes, keeping them well under the surface, and gently moving while in bath; after which take feathers out and rinse twice in clear cold water. Meantime dilute one pound of logwood in about one and a half gallons of boiling water, and boil for about fifteen minutes; after which enter your feathers and let them remain in bath about four minutes; then take out and rinse thoroughly in two waters. Dilute one ounce of bichromate of potash in one gallon, more or less, of boiling water, enough to completely cover up your feathers, dissolving bichromate of potash thoroughly. Enter your feathers, let them remain in bath about three minutes; after which take them out and rinse thoroughly. Meantime have logwood bath boiling, and return feathers to it. Cover up, and let them remain about eight minutes; take out and rinse twice as before. After rinsing, prepare a bath of about half an ounce of bichromate of potash and salts of tartar about the size of a pea in a gallon of boiling water; dissolve thoroughly. Let them remain in bath about three minutes; after which take out and rinse thoroughly in cold water. Then mix a bath of hot soap-suds, and enter feathers; wash well and rinse in luke warm water. The washing and rinsing is not absolutely necessary, in fact, it can not much improve what is already a clean, glossy black. Washing, however, if productive of a change at all, must be beneficial. Then proceed to mix a small handful of starch in a small quantity of cold water; pass feathers through and dry. While your feathers are in the bichromate of potash bath, they must be kept moving in bath constantly and well under the surface. There is nothing to be added to make a successful result, except it be to caution you to adhere as strictly as possible to the recipe. It often occurs that feathers are brought in to be dipped over that have faded out, or have grown rusty looking from exposure to light and long wear. The color can be restored by simply passing them through the last two baths for the same length of time that is allotted to the regular recipe. During the process of drying black be sure to have the starch beaten out as fast as it dries. It is best to dry them in the open air, and, if possible, allow them to hang in the sun for a while, as it improves the color. One especial advantage this black has over most others, is that it improves with age; and, instead of fading, the black will grow more intense. LILAC. Wash and rinse thoroughly in hot soap water, and rinse in about four waters to remove any particle of soap that may adhere to the feathers; next prepare bath of one gallon of hand warm water, and add a handful of starch. Enter feathers and rub thoroughly between the hands; remove and add to bath a few drops of diluted violet, according to shade required; add about two drops of diluted saffranine, and re-enter feathers, let remain in bath about three minutes, squeeze out and dry in powdered starch in the usual way. Be sure your starch is clean and free from acid, and also that your board is in the same condition. Great care should be exercised to see that every particle of the violet is dissolved to avoid spots on the feathers. Should quite a bluish shade be desired, a drop of diluted aniline green added will produce the desired result. GENDARME BLUE. Prepare feathers by washing thoroughly, and rinse about four times in hot water to remove any particle of soap that may adhere to the feathers. Prepare a bath of a teaspoonful of indigotine powder to one gallon of boiling water. Mix thoroughly and enter feathers, and let remain in about one minute, after which remove and add about one teaspoonful of oxalic acid or same quantity of sulphuric acid, and re-enter feathers, letting them remain in bath about five minutes longer; then remove from bath and cool off. Reserve a small portion of bath, and cool off with cold water, adding a drop of sulphuric acid and a small handful of starch; pass feathers through and dry in powdered starch by rubbing between the hands or by simply beating out on a clean board, used only for drying acid colors. Should you find your color too dark, thoroughly rinse off all the starch and pass feathers through a bath of boiling water and let remain about half a minute; pass through starch bath and dry. If found too light, simply increase temperature of bath by adding boiling water and few drops more indigotine; re-enter feathers and let them remain in bath a couple of minutes longer. [Illustration: OLIVE--page 36.] [Illustration: PLAIN, DRAB--page 78.] [Illustration: TERRA COTTA--page 42.] [Illustration: PLUM--page 35.] TRILEUL. Wash and rinse feathers thoroughly in hot water and soap, and rinse thoroughly in about four hot waters; then pass through a bath of plain boiling water; next prepare a bath of one gallon of luke warm water, and add a handful of starch. Enter feathers and rub thoroughly between the hands; remove and add a teaspoonful of oxalic acid; enter feathers and let them remain in bath about two minutes; then remove and add to bath a few drops of diluted picric acid, and re-enter feathers; let remain in about one minute longer, take out and dry in the usual way by rubbing in powdered starch between the hands and beating out on a clean board until all the starch has been removed from the fibre. Should you find your color a shade too dark, mix a luke warm starch bath, and pass feathers through, keeping them under about half a minute, and dry as usual. Be careful that your picric acid is thoroughly dissolved, as otherwise it will be likely to spot your feathers, if the particles come in contact with the flues, and the spots are very hard to remove, as it would be necessary to put them through a bleaching process. ARMY BLUE. Prepare feathers by washing and rinsing thoroughly in hot water. Be careful about rinsing to remove every particle of soap that may adhere to the fibre, after which prepare bath as follows: One teaspoonful of indigotine powder, diluted in one gallon of boiling water, and add thereto about half a teaspoonful of oxalic acid, stirring around well to thoroughly dissolve every particle of color. Enter feathers and let them remain in bath about four minutes; after which take out and rinse in luke warm water to remove the acid in feathers; next prepare a bath of one gallon of hand warm water and add a small handful of starch; add thereto a cupful of boiled logwood liquor and a few grains of copperas, enter feathers, let remain in bath about three minutes; take out and dry by rubbing between the hands in powdered starch, and beat out on a clean board until all the starch has been removed. Should you find your color darker than shade required, prepare a bath of half a teaspoonful of oxalic acid in a gallon of hand warm water, and pass feathers through about half a minute; take out and pass through boiling water, after which pass through starch bath and dry. Should you find shade too light, add more logwood to bath, increase temperature, let remain in a couple of minutes longer and dry. PURPLE. Prepare feathers by washing in hot water and soap thoroughly, and afterwards rinse in about four hot waters to remove every particle of soap and dirt; after which prepare bath as follows: Take one gallon of water about 200° Fah.; dilute therein half a teaspoonful of Violet 3 B., stirring it around thoroughly to dissolve every particle. Enter your feathers and let remain about five minutes; after which take out and pour out the bath, reserving some, and cooling it off with cold, clean water, add a small handful of starch and pass feathers through, first cooling them off by shaking them in the air; rub them between the hands in starch bath to aid the flue or fibre to expand; after which squeeze out and rub thoroughly between the hands, and beat out on a clean board until every particle of starch has been removed. Should you find the top or tips a darker shade than the bottom, or should they bronze or assume a metallic appearance, pass feathers through a bowl of boiling water with a small pinch of soda added, and rinse; after which pass through a new starch bath with a few drops of diluted violet added; take out and dry. MEDIUM GREEN. Prepare your feathers same as for bottle green. Prepare bath by diluting about one ounce of turmeric in a gallon of boiling water, and enter feathers, letting them remain in bath about two minutes; after which take out and rinse in cold water twice. Have boiling a medium strong bath of logwood, and pass feathers through for a few seconds, first cooling off temperature of logwood bath a few degrees with cold water; after which rinse off thoroughly, and prepare a bath of a quarter of an ounce of bichromate of potash in a gallon of boiling water, dissolve it thoroughly, and enter feathers; let them remain in this bath about ten seconds, and take them out and rinse thoroughly in cold water. Proceed to dilute one teaspoonful of turmeric and a half teaspoonful of aniline green in a gallon of boiling water, and reduce temperature a few degrees with cold water. Enter your feathers, and let them remain in bath about three minutes; then take them out and cool off a small portion of bath, and add a small handful of starch, and dry in the usual way. If found to be too dark, add a few drops of diluted oxalic acid to starch bath, and pass your feathers through for a few seconds. If found too light, rinse off the starch in cold water and return to logwood bath for a few seconds, without increasing the temperature any, and rinse off and give a weak bath of bichromate of potash, rinse off and dry. BEIGE. Prepare your feathers by washing and rinsing thoroughly, or if old light colors, bleach with permanganate of potash, being sure to rinse out in hot water to remove acid from feathers, before putting in bath. Dilute a small quantity of starch in a gallon of boiling water, and enter your feathers, rubbing them around in bath between the hands to expands the flues and admit the color evenly on feathers. After which add to bath a small pinch of copperas, about the size of a bean, and about a teaspoonful of turmeric, and enter your feathers, letting them remain in bath about one minute; take them out, and add about a teaspoonful of logwood liquor; re-enter your feathers, and let them remain in bath about one minute, first increasing the temperature by adding hot water; after which remove feathers from bath, and add thereto a few drops of diluted Bismarck brown. To bring the ecru tint desired, a few seconds before taking feathers from bath to dry, add a couple of drops of diluted violet, squeeze out and dry. If a very dark shade of beige is wanted use a greater amount of logwood and Bismarck brown, and if lighter shade is desired, less color should be used. Should your color be found altogether too dark for sample, dilute about half a teaspoonful of oxalic acid in a gallon of hot water, more or less. Pass your feathers through for a few seconds, and rinse off twice in luke warm water and once in boiling water. Then mix a fresh bath of luke warm water and starch, and add thereto a small proportion of turmeric and diluted Bismarck brown, and copperas about the size of a pea. Enter your feathers, and, using care, bring to the desired shade. [Illustration: NAVY BLUE--page 31.] [Illustration: MAGENTA--page 69.] [Illustration: PEA GREEN--page 80.] [Illustration: BRONZE--page 74.] CORN COLOR. Prepare feathers by washing and rinsing thoroughly if dirty greasy whites, or bleach with permanganate of potash if faded out light colors. Prepare your bath as follows: Take one gallon of luke warm water and dilute therein a small handful of starch, and rub your feathers around between the hands. Add about a half teaspoonful of turmeric and dilute well in bath. Enter your feathers and rub around well between the hands. Increase the temperature of your bath by adding hot water, and allow your feathers to remain in bath about one minute; then take them out and add a couple of drops of diluted aniline brown; re-enter feathers and let them remain in bath about one minute longer; then squeeze out and dry as usual. If your shade to match be considerably on the yellow shade, use very little aniline brown, about one drop, and if more on the brown, use less turmeric. If your color be entirely too dark and dull looking, dilute half a teaspoonful of oxalic acid, and pass feathers through for a few seconds and rinse off in luke warm water. Prepare a fresh bath and enter your feathers, as per recipe; or, if wanted a very bright shade, wash off with soap and hot water, and rinse thoroughly in hot water. Then prepare a bath of one teaspoonful of turmeric, one teaspoonful of oxalic acid and one teaspoonful of diluted Bismarck brown in a gallon of luke warm water. Enter your feathers and keep in bath about two minutes, add a little starch to bath, and pass feathers through for a few seconds longer, squeeze out and dry in the usual way. ELECTRIC BLUE. Feathers must be white, or nearly so, to make a good clear shade of electric blue. Prepare your feathers by washing with soap and hot water if dirty whites, and if old, faded light colors bleach with permanganate of potash. Prepare your bath as follows: Take half a teaspoonful of cotton blue and a half teaspoonful of oxalic acid,--a little more or less matters not,--in a gallon of boiling water. Enter your feathers, and let them remain in bath about five minutes; after which take out and rinse twice in cold water and once in hot water to remove all acid and loose color. Prepare a bath of about one cupful of logwood liquor and a small pinch of copperas in a gallon of hot water, not quite boiling, however, and pass feathers through for a couple of minutes. Cool off a little of your bath, and add a small handful of starch and a few drops of violet, pass feathers through and dry. MEDIUM BROWN. All light colors can be made a handsome shade of medium brown without removing the color by bleaching or without washing, unless very dirty and greasy. Prepare your bath by diluting about two ounces of turmeric and a half ounce of copperas in one gallon, more or less, of boiling water. Enter your feathers, keep them well under the surface of bath, and let them remain therein about two minutes; after which take out, rinse twice in cold water. Have boiling meantime a medium strong bath of logwood, about the same proportion as for black; boil about fifteen minutes, and enter your feathers, allowing them to remain in about one minute; after which take out and rinse off twice in cold water; then dilute about a half teaspoonful of aniline brown in a gallon of boiling water, and after dissolving well, enter your feathers, and let them remain in bath about two minutes; take out and rinse in cold water; after which dilute a small handful of starch in a small quantity of luke warm water, and add to that a couple of drops of sulphuric acid; pass feathers through for a few seconds, squeeze out and dry. Should your color be too dark to match sample, return to starch bath, add a few drops of sulphuric acid, let feathers remain in about half a minute, and dry. If a darker shade is wanted, it is necessary to rinse off starch in cold water, and return your feathers to logwood bath for a few seconds, rinse off and repeat Bismarck brown bath as before. By this process, with a little judgment, all shades of brown can be produced in the most satisfactory manner. MEDIUM BLUE. Prepare your feathers by washing and rinsing thoroughly in hot water; light faded out colors need not be bleached, but thoroughly washed in hot soap suds instead. Prepare your bath as follows: Take one teaspoonful of concentrated cotton blue and one teaspoonful of oxalic acid, dilute it in one gallon of boiling water. Be careful to see that the blue crystals are well dissolved. Enter your feathers, and let them remain in bath about four minutes, keeping them well under the surface. Meantime keep them gently agitated to insure an even color; after which take out, rinse, starch and dry. If your feathers be found too dark for sample, or too much on the purple, rinse off, starch in cold water thoroughly, and pass through a bowl of boiling water, starch and dry, using a few grains of oxalic acid diluted in starch bath. If a very light shade be desired, use but half the quantity of cotton blue, and do not allow them to remain in bath quite so long a time. If a much darker shade be required than the foregoing recipe will produce, then rinse off your feathers thoroughly in cold water, to remove all starch, and pass feathers through a medium strong bath of logwood at boiling temperature for a few seconds, and rinse off twice in cold water; dilute a half ounce of bichromate of potash in a gallon of boiling water, and pass your feathers through for a few seconds only; rinse, starch and dry. Should you get your color too dark by this process, pass your feathers through a solution of half a teaspoonful of oxalic acid in a gallon of boiling water, and rinse off in boiling water twice; then dilute a small quantity of starch in luke warm water, add a few grains of oxalic acid to it, pass feathers through and dry as usual. MAGENTA. Prepare your feathers, whether dirty whites or faded out light colors, by washing thoroughly in hot soap suds and rinsing well in hot water. Prepare your bath as follows: Take about a half teaspoonful of safranine and dilute in one gallon, more or less, of boiling water, and add thereto a half tablespoonful of extract of archil. Enter your feathers and let them remain in bath about two minutes; after which take out and add to bath a few drops of diluted violet, and re-enter your feathers, letting them remain in bath about one minute longer. Then take out and rinse in cold water, and dilute a small handful of starch in bowl of luke warm water; pass feathers through and dry. If found too red for sample, rinse off and add to bath a tablespoonful of extract of archil; return feathers to bath for about one minute, first, however, increasing temperature; next rinse, starch and dry. If found to be too much on the plum for sample, rinse off and add to bath about a quarter teaspoonful of safranine, increase temperature of bath to almost boiling; enter feathers and let them remain in bath about one minute; after which rinse, starch and dry. If found to be too light, add a few drops of diluted violet to bath; and, if too dark, dilute a half teaspoonful of oxalic acid in one gallon of luke warm water, and pass feathers through for a few seconds, rinse off twice or more in boiling water; then prepare bath same as per recipe, and allow them to remain until desired shade is obtained. [Illustration: BLACK--page 53.] [Illustration: ELECTRIC BLUE--page 65.] [Illustration: SCARLET--page 50.] [Illustration: MOSS--page 76.] SEA FOAM. This is a very delicate shade of color bordering on pea green. Your feathers must be white, or nearly so. If dirty whites, wash and rinse thoroughly; and, if old faded out colors, pass through bleach of permanganate of potash; after which prepare your bath of one gallon of luke warm water and a small handful of starch, and enter your feathers, rubbing them around between the hands. Take feathers from bath and add about a half teaspoonful of turmeric; re-enter your feathers, keeping them moving around in bath about half a minute. Then take out your feathers and add to bath a couple of drops of diluted aniline green. Re-enter feathers, first increasing the temperature of your bath a few degrees by adding hot water, let them remain in bath about two minutes longer, squeeze out and dry in the usual way. Should your sample be more on the green, you will simply add a few drops more diluted aniline green; and if more on the yellow, you can use less. If the shade to be matched be darker than your feathers, add more of each color in the preparation of first bath. If a rather dull shade be desired, which in this color is quite frequently the case, a small pinch of copperas about the size of a pea will have the desired effect. Should you find your color entirely too dark for your sample, wash off thoroughly in soap suds, and rinse in hot water; after which dilute a half teaspoonful of oxalic acid in a gallon of luke warm water, pass feathers through for a few seconds and rinse off in luke warm water. Then prepare your bath as per recipe, using a little more care and judgment in your second attempt. SALMON. Have your feathers white, or nearly so, by washing if dirty, or bleaching with permanganate if needed, being careful to rinse thoroughly for the purpose of removing any acid or soap; after which prepare your bath as follows: Take one gallon of luke warm water and a small handful of starch. Enter your feathers and rub around between the hands for a few seconds; then add to bath a few drops of diluted safranine and copperas about the size of a pea. Let your feathers remain in bath about one minute; after which take out and add to bath about one teaspoonful of diluted Bismarck brown, first increasing temperature of bath a few degrees with hot water; re-enter your feathers and allow them to remain in bath about a minute; after which squeeze out and dry in the usual way. If your sample to be matched be more on the pink, use less aniline brown; and if more on the yellow, use less safranine and more aniline brown. Should you desire a much darker shade, use more of each color than laid down in recipe, and add a few drops of logwood liquor. If your feathers be found altogether too dark for sample, rinse off starch in cold water and dilute a half teaspoonful of oxalic acid in luke warm water, and pass your feathers through for a few seconds, take out and rinse a couple of times in hot water (not boiling). Prepare bath again as per recipe, using greater care. This shade of color is on the order of the terra cotta and crushed strawberry, and can be made in the same bath by adding color or diluting. Be careful in drying to use only clean starch and a clean board that has not been used with any acid colors. STONE COLOR. Stone color is a shade varying very slightly from slate and smoke color. All light shades can be used for this color; first preparing them by washing and rinsing them thoroughly. Prepare a medium strong bath of logwood by boiling for about fifteen minutes; after which enter your feathers, and let them remain in bath about two or three minutes, longer if a very dark shade be required; then take them out and rinse in cold water twice. Prepare a bath of half ounce of bichromate of potash in one gallon of boiling water, and dissolve thoroughly. Enter your feathers, and let them remain in bath about two minutes, keeping them well under the surface of bath and moving at the same time, to assist in producing an even color; after which take out and rinse off about three times in cold water, and prepare a bath of hot soap water. Enter your feathers, and wash thoroughly, adding to bath a small pinch of soda; after which rinse carefully in hot water; dissolve a small handful of starch in cold water, pass your feathers through, squeeze out and dry in the usual way. If your feathers be found much too light for your sample to be matched, rinse off starch in cold water, and return your feathers to logwood bath for a few seconds; dissolve a small pinch of copperas in a gallon of boiling water, reduce temperature a little and enter your feathers, letting them remain in bath a few seconds. Take out and pass through starch and dry. If found to be altogether too dark, dilute a teaspoonful of oxalic acid in a gallon of hot water; pass feathers through a few seconds and rinse off in boiling water twice; wash, starch and dry. BRONZE. Wash and rinse thoroughly, using soap for washing, and rinse out in hot water about four times; after which prepare a bath of one quarter pound of turmeric to one gallon of boiling water. Enter feathers and let remain in bath about three minutes; take out and rinse. Boil a bath of half pound of logwood to one gallon of water about ten minutes; enter feathers and let remain in bath about four minutes; take out and rinse. Then prepare a bath of half an ounce of bichromate of potash and one gallon of boiling water, and let feathers remain in bath about two minutes, take out and rinse. Next prepare a bath of one quarter pound of turmeric and one-quarter teaspoonful of Victoria green crystals, and add one gallon of boiling water. Enter feathers and let remain in bath about four minutes; take out, cool off a small portion of the bath and add a small handful of starch. Pass feathers through and dry in powdered starch by pressing between the hands; then beat on a board or table until all the starch is removed from the feather. CHOCOLATE. Prepare your feathers by washing and rinsing thoroughly; and, if necessary, bleach with permanganate of potash. After doing this, rinse thoroughly in hot water for the purpose of removing all acid from the fibre. Prepare your bath of one gallon of water at boiling temperature; add thereto a teaspoonful of turmeric and a small pinch of copperas about the size of a bean. Enter your feathers and allow them to remain in bath about one minute or longer. Take out your feathers, and add to bath about one tablespoonful of diluted Bismarck Brown and a few drops of diluted violet; re-enter your feathers, and let them remain in bath about three minutes, keeping them meanwhile well under the surface of the bath; after which take them out, cool off a small portion of the bath, and add thereto a small handful of starch; pass your feathers through and dry in the usual way. If a very dark shade be required, you will add to bath about a tablespoonful of logwood liquor at the same time you add the violet, and allow them to remain in bath a little longer. Should you find your color entirely too dark for your sample to be matched, rinse off starch in cold water; dilute about a half teaspoonful of oxalic acid in a gallon or more of hot water. Pass your feathers through, and rinse off in luke warm water twice; then pass your feathers through a bath of boiling water, for the purpose of effectively removing the acid; after which prepare again as called for in recipe, using a little more care, and the desired result will be obtained. [Illustration: SEAL BROWN--page 29.] [Illustration: CRUSHED STRAWB'Y--page 34.] [Illustration: ORANGE--page 48.] [Illustration: BISMARCK BROWN--page 28.] MOSS COLOR. Wash your feathers and rinse thoroughly. Prepare your bath of quarter pound of turmeric and a half ounce of copperas diluted in a gallon or more of boiling water. Enter your feathers and let them remain in bath about two minutes; after which take out and rinse twice in cold water. Meantime have a medium strong bath of logwood boiling, and enter your feathers, letting them remain in about one minute, take out and rinse. Then prepare a bath of about two ounces of turmeric and a small pinch of aniline green in a gallon of boiling water. Enter your feathers and allow them to remain in bath about three minutes or longer. Take out and cool off a small quantity of bath with cold water; add a small handful of starch, pass your feathers through and dry. If your color be found too much on the green for your sample to be matched, add to starch bath a few drops of sulphuric acid; or, instead, rinse off starch and mix a bath of two ounces of turmeric in a gallon of boiling water; pass your feathers through for a minute or so, starch and dry. If found to be too much on the yellow or olive, add to your bath a few grains of aniline green, and return them to the same for a few seconds, first rinsing off starch in cold water. If found too light, pass for a few seconds through a weak bath of bichromate of potash; and if too dark, dilute a few grains of oxalic acid in hot water, and add to your starch bath a few drops. Pass your feathers through for a few seconds and dry in the usual way. PLAIN DRAB. If your feathers are old, dirty whites, wash and rinse them thoroughly. If light colors, remove the same by passing through permanganate of potash process, and use great care in rinsing to remove all the acid before entering in bath. Prepare your bath with one gallon of luke warm water and a small handful of starch; enter your feathers and rub them around well in bath between the hands to expand the fibres. Take out your feathers, and add to bath a small piece of copperas about the size of a bean and about a quarter cupful of logwood liquor; re-enter your feathers, and let them remain in bath a few minutes, meantime adding a small quantity of hot water to increase temperature of bath; then add a couple of drops of diluted safranine to bath, let remain in bath one minute longer, squeeze out and dry as usual. If wanted more on the shade of felt drab, use, instead of safranine, a few drops of Bismarck brown; and if wanted more on the steel, use a few drops of diluted violet in bath. If a darker shade should be desired, use only a little more logwood liquor, and allow them to remain a short time in bath. Should you find your color to be altogether too dark for sample to be matched, rinse off starch, and dilute a half teaspoonful of oxalic acid in hot water; pass your feathers through, rinse off a couple of times in luke warm water and lastly through boiling water, for the purpose of removing all acid. Then prepare a fresh bath according to recipe, and pass through until you have obtained the desired shade. COFFEE COLOR. Old faded out light colors need only to be thoroughly washed and rinsed to prepare them for this color; and darker colors can be prepared by bleaching with permanganate of potash, taking care to rinse thoroughly in hot water for the purpose of removing all the acid. Prepare your bath of about one teaspoonful of turmeric and copperas about the size of a bean in a gallon of boiling water. Enter your feathers and let remain in bath about two minutes; remove feathers from bath and add a half cupful of logwood liquor and return feathers to bath, letting them remain in about one minute; after which remove feathers and add to your bath about two tablespoonfuls of diluted Bismarck brown and hot water to increase temperature of bath; re-enter feathers and allow them to remain in about two minutes; after which cool off a small quantity of the bath and add a small handful of starch; pass feathers through and dry. If found to be too light, return to bath, first adding more logwood liquor and Bismarck brown, and let them remain in bath about one minute. If too dark for your sample to be matched, dilute a few grains of oxalic acid in luke warm water; pass feathers through for a few seconds and rinse off three times in luke warm water. Then prepare bath as per recipe, using more care in the preparation. If found too much on the yellow, a few drops of diluted safranine added to your bath will produce the desired effect. Use clean starch in drying; if a table or board is used, see that it is perfectly clean and free from acid. PEA GREEN. Prepare your feathers by washing thoroughly in hot water, and rinse thoroughly to remove any soap that may adhere to the feathers. Then prepare a bath by diluting a handful of starch in a half gallon of hand warm water, and rub feathers around between the hands. Remove feathers and a add a few drops of diluted Victoria green and a couple of drops of diluted picric acid. Enter feathers, letting them remain in bath about two minutes, keeping them well under the surface to insure an even color. If wanted a shade more on the yellow, add a drop more of picric acid; and if more on the blue, leave the picric acid out entirely. Take out and dry in starch, being careful to beat out on a clean board in the usual way. OLIVE BROWN. Wash feathers thoroughly in hot water and soap, and rinse about four times in hot water; after which prepare a bath of half a pound of logwood; first enter feathers in one-quarter pound of turmeric and one gallon of boiling water; let them remain in bath about four minutes. When logwood bath has boiled sufficiently, say ten minutes, rinse feathers out of turmeric in cold water; and enter in logwood, letting them remain in bath about six minutes; take out and rinse. Prepare a bath of half an ounce of bichromate of potash and one gallon of boiling water; enter feathers and let remain in bath about one minute; take out and rinse thoroughly in cold water. Mix a bath of one ounce of turmeric to one ounce of archil and half the old logwood bath; bring to a boil and enter feathers, letting them remain in bath about six minutes; take out and rinse. Then mix a bath of luke warm water and starch, add a couple of drops of sulphuric acid and a couple of drops of picric acid diluted, pass feathers through, squeeze out thoroughly and dry by rubbing in powdered starch between the hands; beat out on a clean board until all the starch is removed from the feathers. [Illustration: MEDIUM BROWN--page 66.] [Illustration: OLD-GOLD--page 39.] [Illustration: CARDINAL--page 33.] [Illustration: MEDIUM GREEN--page 61.] PROCESS OF DEGRADING OR BLEACHING NATURAL GRAY OR BLACK WHITE. Begin by washing and rinsing your feathers thoroughly; after which soak in a bath of compound of one gallon of ammonia to eight gallons of water for about eight hours; take feathers out and squeeze out the excess of ammonia which is in the flues. Put your feathers in the peroxide of hydrogen with an addition of twelve to sixteen ounces of ammonia to one five gallon can or demijohn, and let it work slowly, stirring feathers from time to time for about six hours; after which lay your feathers on one side of the tub and add to the peroxide of hydrogen bath about four ounces more of ammonia; stir the bath well to insure a thorough mixture of the peroxide of hydrogen with the ammonia. The peroxide of hydrogen will continue to work for about twelve hours more, until it becomes thoroughly exhausted; after which take out your feathers and rinse a few times in luke warm water. Then proceed to put them in a second bath of peroxide of hydrogen to be prepared as follows: To a half gallon demijohn of peroxide of hydrogen add two and a half gallons of water, and add thereto about eight ounces of ammonia. Then enter your feathers, and allow the bath to work a few hours; again add about two ounces of ammonia by the same process as before, and then let it work a few hours longer, or until the bath becomes exhausted. To ascertain whether total exhaustion has taken place, take a small portion of the bath in a glass and dilute therein a few grains of permanganate of potash; if it be not totally exhausted, bubbles will appear on the surface; if exhausted, none will be noticeable. After your feathers have been removed from the bath they must be carefully rinsed off in three or four waters, a few degrees more than luke warm. Then prepare a warm soap bath, and allow your feathers to remain in a few minutes; after which rinse off thoroughly in luke warm water; dilute a small handful of starch in a quantity of cold water, pass your feathers through and dry. All natural color will have entirely disappeared. Whatever portion of the amount of feathers you have just bleached are for whites, before drying them up, prepare a bath as per recipe for white, pass through and dry in the usual way. This process of bleaching is used only when it is desirable to make light colors from gray or natural black feathers, but feathers for navy blue, seal brown, bottle green, etc., will not be improved by bleaching. The shade of color can be evened off in the bath. HINTS ABOUT THE DYEHOUSE. In dyehouses where steam is used, it is necessary to boil your bath a longer time than where the bath comes in direct contact with the fire. The accommodations of a dyehouse for the re-dying of ostrich feathers need be very simple and inexpensive; in fact, I have seen a dyehouse where old re-dyed transient work to the amount of fifty dollars per day was accomplished with a small cooking stove, a wash-boiler, a wash-bowl and a tin dipper; costing in all less than six dollars. Of course, in the manufacture of raw stock it is necessary to have larger vessels and much better facilities; for instance, instead of from ten to fifty, or even a hundred feathers, you will of necessity be compelled to dye lots of from five to ten pounds of goods at one time. Two stationary tubs or vats, one for use in washing white and bleaching, and the other for black, with water pipes and steam pipes and connections; a few large porcelain lined or copper basins for dark colors are essential; it is also well to have an outer room or inclosed closet to keep your dyestuffs in, as it is important that they be kept clean. When cans of color are opened for the purpose of diluting a portion or making a color, have the cover replaced and returned to closet when through with it. Have bench or table whereon rests your basins, while you match shades in making colors, if possible, where a north light will strike it; and if cold weather and the windows closed, keep the glass clean. You will often get various reflections in the dyehouse that cause a great deal of trouble to the dyer; as, for example, if the sun should be shining on a red brick wall and the reflection beating into the dyehouse, it will often lead the dyer astray, and while he thinks he has a perfect match, when the color goes into the office there is a decided difference. The great majority who are expected to be benefitted by this work are not ostrich feather manufacturers, but the job dyer; and it is my object to simplify the dyehouse as well as the methods of dyeing. A small corner of the dyehouse can be used, and a couple of ordinary wash-bowls, a common wash-boiler and a tin dipper are really all the utensils that are practically necessary to complete the dyehouse for the renovator. A couple of hours in the morning devoted to feather dyeing, and a good practical man can turn out fifty dollars worth at a cost of only his two hours labor, and perhaps fifty cents worth of color. Feathers can be dried in an ordinary hot room or, if warm weather, out in the open air. The dry room where large quantities of feathers are dried should never be too warm, as the feathers are apt to dry up quicker than the boys can beat the starch out of them; and, as a consequence, the flues or fibres are not expanded as they should be, and the feathers are much harder to curl. The board or table used to beat the feathers on must be perfectly smooth, as there is otherwise danger of tearing out the flues. The drying of feathers is quite an important operation, and if not understood, can result in ruining a great many by drying them improperly, allowing the starch to dry up on the flues without beating it out, and by breaking the quills. The dry room is only used when the weather is too inclement to dry in the open air, or when you have not got outside accommodations. The yard or roof is far preferable to the dry room, and especially so for white and black feathers. After having been washed and the starch thoroughly removed, it will improve them greatly to expose them to the sun for an hour or two. Colors, especially delicate shades, should not be allowed to hang in the sun only during the actual time required for drying a black made by our process; it greatly improves upon exposure to the sunlight, giving it an advantage over all others. Baths of logwood or old garnet baths that you are desirous of saving for future use, it will be well to remove them from the copper or tin basins or pans to wooden buckets or crockery jars, and cover them up for the purpose of excluding all foreign matter. MISCELLANEOUS INFORMATION. In the re-dying of old feathers the first thing necessary is to enter them in book by whatever system you may think best; after which they are assorted as to color, the blacks, browns, greens, blues, etc. Put in separate lots and then string them and mark your tickets. You will often find when you have selected your colors a number of different shades to be dyed one color; as, for example, when you come to string your browns, you will find a blue, a green, a garnet, a drab, and perhaps a dozen different shades of colors; string them all on at once and enter together, and dye a good medium shade of seal brown and dry; after which you proceed to take them off the string, and place them with their respective tickets. You will now find, perhaps, one a shade too dark for your sample, another perhaps a shade too light. The former you would pass through a weak solution of sulphuric acid in starch bath, and the latter through a weak solution of bichromate of potash. Another one you may find a little too red for sample, or too yellow. These, in turn, you can bring to match your sample as per recipe for brown. In beginning the days work, it is well to do all your bleaching and cleaning first, while your hand basins and dyehouse are in a clean condition; after which the blacks, as they require logwood good and pure, and the same logwood used for them can be used for all other colors where logwood enters into their composition. Consequently one bath of logwood boiled in the morning will do all the work for the day. In Chicago I remember, while giving instruction to a gentleman, who had come down from St. Paul, Minn., for the purpose of learning the art, that in one afternoon I taught him how to make every color and shade of color known, and my logwood bath that was used during the whole day's work was boiled in a small sauce-pan that held about two quarts. It had been used in making black, browns, greens and navy blues of all shades, and was still in good enough condition to make any color, excepting perhaps black. Keep your bath of logwood covered at all times when not in actual use, and, indeed, then, if convenient, to prevent any foreign substance from entering it. It is the custom of a great many ostrich feather dyers to keep a quantity of starch in the dyehouse for the purpose of dipping their feathers into it and partially beating them out prior to removing them from the bath for the purpose of drying the ends up to see if they match sample. This is a very bad practice, for the loose starch flying through the dyehouse will settle on the uncovered colors and cause not a little annoyance and trouble. Keep the starch out of the dyehouse; keep it in the drying-room where it belongs. In drying your feathers out of the baths in starch it is well to have two boxes,--one to be used for colors that contain acid; as, for example, light blues, lemon, etc.,--the other for those colors that contain none; such as drabs, pinks, etc. In dissolving colors use ordinary bottles, and be sure to always use boiling water for the purpose of diluting. Let the proportions be about one teaspoonful of color to one pint of boiling water. Shake gently to thoroughly dilute aniline, and cork or cover bottles to keep out dirt. Colors that are used in making very delicate shades, such as pinks or light blues, it is well to tie around the top of the bottle in place of a cork a small piece of muslin. It will act as a strainer, and prevent particles of color that may not have been thoroughly dissolved from passing into the bath and spotting your goods. Do not be too careful of the hands and afraid of getting them covered with dyestuffs; use them in the bath instead of sticks at all times, excepting where the liquid is too hot to permit it. The best method of cleaning the hands, no matter how dirty, is to pass them through a solution of soda, about one-quarter ounce in a small quantity of hot water; rinse off in cold water, and take about a teaspoonful of chloride of lime, moisten with water and rub the hands gently with it until all color has entirely disappeared; then wash with soap and hot water. WASHING RAW STOCK. First string your feathers, being careful to place the string on the end of quill so as not to get any of the flues under the loop; then slice down according to quantity of feathers to be washed, from one to more pounds of soap in boiling water, and boil down to a liquor; after which fill a clean tub half full of luke warm water, and pour soap into it; then enter your feathers and give them a slight rubbing. Then push them well under the surface of the water, cover them up and allow them to remain over night. In the morning run off dirty water and squeeze out your feathers; enter your feathers in a tub of clean luke warm water and use an ordinary wash board and a soft scrubbing brush. Rub bar soap on feathers, and brush gently, being very careful not to tear out the flues. Soap and brush one string at a time, manipulate them much after the manner of a woman handling a large wash. Be careful to give minute attention to the bottom portion of the feathers, as the flues are always more closely stuck together with the natural grease of the bird, and it often requires an amount of hard labor to remove. Repeat the washing operation and rinse off in about three luke warm waters, starch and dry. In starching rub the feathers around well between the hands for the purpose of getting all the flues thoroughly expanded, squeeze out of bath and hang on lines to dry. Put no more out at once than the dyers can comfortably handle, as it is well to have them beat out on board at regular intervals of a minute or so; thereby expanding the flues to their utmost. The process of selecting the different grades or qualities follow, and it is necessary for the person performing this work to be familiar with the application of dyestuffs to feathers, to insure the dyer less trouble; as the different qualities all put in the bath together, and going through exactly the same process will come out different shades of color, will cause the dyer a great deal of trouble and labor getting them all an even color. When a batch of feathers are intended for white it will not be necessary to dry them first; simply wash and rinse, and prepare your white bath as per recipe, and pass them through it. It is scarcely necessary to remark here that natural black and gray feathers must not be washed at the same time with whites, as the latter would not be improved. Strings should not contain more than fifty plumes, for, if they are made much longer, it would be awkward to handle them. Tips, however, are often strung three or four in a bunch, according to size, and an ordinary string may contain two or three hundred. In washing natural black tips it is advisable to use a brush on them during the first rinsing to remove all particles of soap therefrom. SHADING. Shading from dark to light colors is the result of submerging one portion of the feather in the bath and withholding the balance. Great care and not a little skill is needed to produce a satisfactory result. There are various ways of handling the goods, covering up the portions to remain the light shade or holding them out with the hands. Spotted or speckled feathers are produced by first dyeing the light shade that you desire to be spotted, and then wrapping around a round stick with cord, according to the size you desire to have the spots, you will regulate the weight of cord used. After having bound the cord tightly around the feather and stick, which must then be tied firmly to keep from slipping, pass through boiling water for a few seconds for the purpose of expanding the wood and contracting the cord, thereby making the cord much tighter. After you have made them whatever dark color you desire, take out, starch and pass through dry starch; then remove cord and dry your feathers, when you will find that the portion covered by the cord will be the light shade, and the feathers have the appearance of being dotted all over. Natural blacks or grays can be speckled as follows: Go through the same preparations of binding around stick with cord and degrading or bleaching them white. The result will be that the portion covered with cord will be same as before entering the bath, a black or dark brown, and the body of the feathers will be white. Should you desire the feathers dyed any light color to contrast with the dark spots; before removing the cord, mix your bath and dye as per recipe, dry as before directed, and the result is very beautiful. Some very nice effects are produced in shading by taking natural grays or bioucs, that is, feathers that are one portion white and the balance in spots, black. PARING, STEAMING AND CURLING. Feathers that have just come out of the dyehouse for the first time require paring, which consists in removing the quill from the inner portion of the feather, thereby making the feathers more elastic. The feathers must first be thoroughly dried; they are then taken, one at a time, held between the thumb and two fore fingers of the left hand, while, with a knife held in the right, the inner quill is rapidly removed close to the flues or fibres. This branch of the business is in itself a trade, and requires a great amount of skill and caution to prevent cutting through the quill. The feather can be made still more limber by scraping the quill with a piece of glass. Of course, this process of paring the quill is only used in new work. In re-dying old feathers it is never needed; in old work it is only necessary to dry up thoroughly, steam and curl. A great many have no knowledge of what relation steaming has to the finishing of feathers. It has the effect of making all the flues lie perfectly straight beside each other, and also dampens the feathers just enough to assist the curler in her work. It is necessary to have a steamer made as follows: get a kettle that will hold about one gallon or more of water, made out of plain tin, with a spout commencing at the base about two inches in width and tapering up to a half inch in width at top. The spout should be about eighteen inches in length; the total cost should not be more than one dollar. Never have it more than half full of water, and you can boil it on either an ordinary stove or common gas or oil stove. You may ask why steam from the boiler, or out of an ordinary tea-kettle would not answer? It is too wet. Instead of having the desired effect it wets the flues, while the other dampens it just enough. The steam emitted from the steam kettle is drier than any other. When the steam is passing through the tube take hold of the feathers by either end and pass backward and forward for a few seconds about two inches above the top of pipe, and lay down perfectly flat, one on top of the other. Curling is a trade that can only be thoroughly mastered by practice; the principles can be taught, but only practice will make perfect. It does not, however, require a great while. I have known persons that within three months had become first-class curlers, practicing a short time each day. The feather is held between the first and second finger and thumb of the left hand and a few flues taken up at a time with the knife held in the right hand, and gently drawn along the round dull edge of the knife, and allowed to drop in a half circle; begin at the bottom of the right hand side of the feather, work up to the top and around and down the other side; and in laying up take up about three flues at a time, skipping about six. Feminine fingers are generally better adapted to this work than others, and, in fact, it is more of a woman's work than a man's. Tips are generally bent and branched. You can give the feathers a nice droop by taking the quill between the thumb and fore-finger, and with the thumb pressing the quill through between the first and second finger. Begin about the middle of the feather, and, shifting about a quarter inch at a time, pass swiftly up towards the top, when the feathers will have a very beautiful droop. Plain wire stems can be used. Take thin wire, cut about five inches in length, and twist one end of it on stem or quill of your feathers so as to hold; then take tissue paper, cut in strips about a half inch wide, and in color corresponding with the shade of feathers; wrap it around wire to entirely cover it up, and then branch tips, two or three in a bunch, as suits your fancy. NOTE OF THE PUBLISHER. The old maxim, that "seeing is believing," applies perhaps nowhere more than in dyeing. All those who have availed themselves of the opportunity to see the method of dyeing ostrich feathers practically executed before their eyes by the author, as described in the foregoing pages, are satisfied of and willingly testify to its superiority over any of the methods heretofore known, practiced and often acquired at the cost of much money, time and trouble, and which, in many cases, when put to the practical test, failed to give the desired results. Yet there are probably many more disbelievers than believers in any new method, however freely and truthfully certified to, who mistrust the quick work of our new processes of ostrich feather dyeing, and who would rather prefer to operate after a somewhat slow but (in their opinion) therefore surer, older method. They shall not be disappointed by perusing our book and in looking up something which they would want to try in practice, and for them especially we supplement our book with the following Appendix, containing a number of practically tested recipes for dyeing ostrich feathers. APPENDIX. GENERAL REMARKS. The cultivated taste of the present age, requiring a large variety of natural and artificially produced or embellished material for adornment, employs almost any kind of bird's feathers, either in their natural coloring or dyed. None of them, however, are used in the condition as they are plucked from the body of the live or dead bird, but all must undergo a cleaning process, which not only serves to improve their appearance, but is an exceedingly essential requisite for the preservation of the material from decay and the attacks of moth and other insects, and is, above all, the first condition and indispensable preparatory operation for dyeing feathers, whether the costly feather of the ostrich or the common feather of our domestic chicken or pigeon. The cleaning or washing process is the same for all kinds of feathers; the ostrich feather, however, requires drying after every treatment in a bath, and a special operation for the purpose of opening the fine flues, which gives the plumage of the ostrich its characteristic and distinguishing beauty and rich, downy appearance of luxurious softness. The feathers of the ostrich, which are used for dress-feathers, are taken from the wings and tail of the bird, whose spurred wings, by their peculiar construction render it entirely unfit for flight. The wings seem rather only fit to serve for the purpose of holding the body of the bird in equilibrium while running, and of preventing it from sinking to any depth into the loose sand of the deserts, which are the home of the ostrich. The natural colors of the ostrich feathers are white, black and gray, or rather a dark drab. They are, therefore, sorted according to their natural color, to be bleached white, or dyed in light colors, or to be used for dark shades. Practical men in the general dyeing business, and in garment dyeing or re-dyeing, hold that it is unnecessary to bleach, respectively strip, the material for dyeing dark colors, and garment dyers strip their material only to a certain extent, so as to leave upon it a bottom of color which they can advantageously use for their new dye. This method appears correct, if as "practical" as all that is designated, which results in a saving of expense or labor; but it is evident that a clear color of the highest possible beauty can never be obtained upon a bottom of a different hue; the bottom color will always, more or less, show and impair the purity of the topping color; but compound or mixed colors can be thus produced in an advantageous manner and to good effect, if the color of the bottom enters into their composition. The same is unquestionably the case with ostrich feathers, and the dyer is often compelled and must be prepared to bleach the gray or black and white feathers in order to dye them any light shade. The bleaching of naturally purely black feathers is probably but seldom required, as these are ordinarily left as nature has made them, but merely cleaned to heighten their beauty and gloss. Owing to the delicate nature of the material, the dyeing of ostrich feathers bears much similarity to that of silk; both being high in price, carelessness and negligence in their treatment is apt to entail heavy losses. The utmost cleanliness of all utensils is an absolute requirement; dyestuffs, drugs and chemicals must never be added to baths in substance, but always in solution, and never while the material is in the bath; but the material must be taken up while the dyestuff or salt, etc., solution is being added to the bath, and only re-entered after stirring well. Solutions, as well as decoctions, must always be filtered, respectively strained, before adding them to the dye bath, even if they have been prepared beforehand, because any undissolved or solid particle of substance deposited upon the feathers would necessarily produce a spot or mark of a darker or lighter shade, as the case may be, according to the character of the undissolved substance. Although alkalies and heat are applied and necessary for washing or scouring, that is, cleaning and ungreasing the feathers, strong alkaline and excessive heat operating together are as fatal for feathers as they are for any other animal fibre,--wool or silk,--and strong heat applied to dry feathers is apt to irretrievably ruin them. The soap with which feathers are to be treated, must, therefore, be as neutral as possible, and if recipes speak of "boiling" the feathers, it must be understood in the sense as in wool-dyeing, that is, to apply a heat near the boiling point, when the baths begin to throw up bubbles, but not actually boil. That the water used for any purpose in ostrich feather dyeing, for washing, bleaching, dyeing or rinsing, must be perfectly clean, needs hardly to be mentioned. UTENSILS. The utensils required for feather dyeing are of a very simple character, few and inexpensive. For small establishments an ordinary stove, a common wash-boiler, to have constantly hot water on hand, an ordinary wash tub, a white china wash-basin for dyeing, a clean board for starching and a few bottles, together with a small tin pan or kettle and funnel, for making solutions and decoctions and filtering them, is all that is necessary besides the work table. More recently, flat, oval upper pans, tinned for special purposes, have been introduced as dye-vessels, which are neatly provided with a moveable perforated false-bottom, and are heated either upon a direct fire, or a gas jet, or by direct steam. In large establishments copper pans are generally used, for the better grades of ostrich feathers especially, and for ordinary goods wooden tubs, both heated by steam. Where wooden tubs are used, several of them are set apart for the color most in demand, such as black, brown, gray, mode, etc. PREPARATION OF THE FEATHERS. The bundles received from the dealer being opened, the feathers are sorted according to color and size, and those for white and light colors, to be bleached, are laid from those of dark colors, which are ordinarily not bleached, that is, the black or gray ones. When going to work the feathers are put on strings, that is, they are firmly tied singly, about an inch apart from one another, and about an inch above the end of the quill, 20 or 25 with one string, seldom more, as they would make the bundle too thick and unhandy. The feathers are then ready for the steep, which operation ought always and for any method be the first step of treatment before proceeding to washing, scouring and bleaching proper. For this purpose a strong solution of soap is made in boiling water; when cooled down to about 150° F., it is well stirred, the feathers entered and left in the bath over night. The temperature may be kept up over night. It is necessary, however, to lay the feathers down in the steep so that the liquid can reach every part of them, and to keep them well immersed in the steep, for which purpose it is advisable to weigh them down by clean sticks of wood or some other means. Instead of soap, soda may be used for the steep; taking about one and one-half ounces of soda crystals to one gallon of water. By the steep the impurities, dirt and grease, covering the feather are loosened, and thereby the following cleaning operations materially facilitated. CLEANING AND BLEACHING OF FEATHERS. The ostrich feathers, like all material taken from the covering of the animal body, wool, hair, etc., which are embellished by dyeing for the use of man or woman in dress, contain by nature a certain amount of fat, and in their raw condition are more or less covered with dust, dirt and a greasy exudation, which must be removed for dyeing; that is, they are scoured or washed and then bleached or whitened, because the feathers, like all other so-called white animal matter, have always a faint yellowish tint, sometimes yellowish spots which cannot be removed without injury to the material, but obliterated by bleaching, which, in the case of white feathers, is called bleaching or whitening. The bleaching of gray and black feathers and the stripping or decoloring of dyed feathers are different operations. For scouring or washing, novel methods are recommended, which, however, differ from one another very little, and are, on the whole, represented by the following: Prepare a good handwarm bath (100-120° F.), in which dissolve two ounces Marseilles soap in per gallon of water and beat up to a good lather. Enter feathers and rub them well, string for string, by hand. They may even be taken upon a wash-board and rubbed with a brush, which does not hurt them, notwithstanding their delicate structure, because the soap steep has given them great elasticity and resistance to the manipulation. Continue the operations until the tank is exhausted and dirty; then give another fresh bath of the same composition and temperature; treat the feathers as in the first bath and rinse them perfectly clean from every particle of soap in two or three luke-warm (100°) waters; for, every trace of soap remaining upon the feathers will hinder the dye from running up and cause uneven colors, or, upon white feathers, yellow stains. Then prepare a cold bath with solution of bioxolate of potash (one-eighth to one-sixth ounce of salt to one gallon), enter feathers, pass them in the bath for 15-20 minutes, take up and rinse them in cold water three to four times to remove the salt. For feathers which have to remain white, the latter bath is composed of one and one-quarter ounces bioxolate of potash and one and one-eighth ounces oxalic acid to one gallon of water, and the feathers laid down in it until perfectly white; when they are taken out and rinsed clean from acid in luke-warm water. The feathers being rinsed clean from the oxolate of potash bath, if destined for white, are then whitened, or rather blued, for the purpose of covering the yellowish tint above mentioned. To this purpose a cold bath is prepared with only so much methyl violet or methylene blue, as to give the water a very faint tint. To ascertain whether this is the case, a white china plate is held about a foot below the surface of the bath, when its appearance will show the shade of blue that will be produced by the bath. The feathers are then entered and gently agitated in the bath until they have the desired tint. DRYING OR STARCHING. The feathers coming from the bioxolate of potash bath, after rinsing, or from the blue baths, are squeezed out by pulling them through the hand, and pressing them between the laps of a dry clean piece of white muslin, whereupon they are immediately passed through a bath of raw starch, that is, unboiled starch, consisting of about one-half pound of starch to a gallon of water. After passing them through the hand the feathers are then again pressed between the cloth; then the waves are lightly drawn by hand over the stems, and the feathers either beaten between the hands or upon a clean board over a stove until dry, or they are agitated by hand or by a suitable mechanical contrivance before an open fire or gas-jet, or hung in a warm room and frequently shaken until dry, that is, until all starch has dropped out; and finally the remaining starch is beaten out between the hands or upon the board by means of a soft brush. By this treatment the feathers are not only dried, but the flues opened besides. It needs not to be specially mentioned, that the feathers are dried, or finished, as it were, in the same manner after dyeing. In case the flues are not sufficiently opened, although all the starch has been beaten out, dip the feathers into clean benzine and swing or agitate them until dry, which takes place in a few minutes, while the flues are opened in the most perfect manner. For white feathers the benzine may be blued, but in this case, they must be dried between muslin. BLEACHING OR DECOLORING NATURALLY GRAY FEATHERS. The feather dyer is often required to dye light colors upon naturally gray or even black feathers. As above remarked, the natural color would show even under dark colors dyed upon them to a greater or less extent, unless they are first decolorized, that is, their natural color destroyed or blackened. Much more necessary is, therefore, this operation for light colors to be dyed upon naturally colored ostrich feathers. The only known chemical agent affecting such a bleach to nearly white is peroxyd of hydrogen or oxygenated water. For bleaching ostrich feathers a bath is prepared of peroxyd of hydrogen to which so much liquid ammonia is added as to give the bath a sharp pungent odor. The feathers, which must be previously cleaned as above mentioned, and well rinsed, are entered and left immersed in the bath until they have assumed a nearly white cream color, whereupon the feathers are taken up and thoroughly rinsed or laid down in running water until every trace of ammonia has disappeared. It must be observed, however, that only acid aniline colors can be dyed upon such decolorized feathers and that in dyeing only a moderate heat must be applied. Dr. P. Ebell, of Linden, near Hanover, one of the first and still largest manufacturers of peroxyd of hydrogen, writes on the subject of feather bleaching as follows: The assorted and picked feathers are cleaned from dirt and fat with soap and water by means of soft brushes, which operation is continued until the feathers (after drying) are readily wetted by water; when they are laid down for some time in pure water. The liquids are removed from the feathers by a centrifugal machine or a wringer (the latter is evidently meant for ordinary feathers, other than ostrich feathers). Mix in a clean wooden tub twenty litres peroxyd of hydrogen (Koenigswæter & Ebell) with four hundred and fifty grammes ammonia 20° B. (=0.9 sp. gra.) and heat to 34° C., by a leaden steam pipe at the bottom of the tub. Enter 5 kilo. cleaned feathers, which work by hand and turn every hour. In twenty four hours the bleach is completed. If pure white feathers are wanted, give a second bath, but for a shorter period. The bleached feathers are carefully removed from the bleaching bath and laid down, for an hour and a half, in a cold bath of one hundred litres water containing one hundred grammes sulphuric acid 66° B., and then completely lixiviated in pure, soft water. While moist (after squeezing) they are then passed through a milk of unboiled starch which is lightly blued with aniline blue or violet, and slowly dried, in the air or in a warm room, under repeated shaking to prevent the flues from sticking together. After removing the starch by beating, the feathers are ready for curling, etc. PEROXYD OF HYDROGEN. This most valuable bleaching agent is a contraction of hydrogen and oxygen, of the formula HO_{2}, sp. grv. 1.45 (chemically given), or 94.12 per cent. oxygen with 5.88 per cent. hydrogen. It consists in a limpid, syrupous liquid, of characteristic color, and when heated to 15° C., is decomposed into water and oxygen, upon which property its great bleaching power is based. Experiments to reduce it to a solid form by refrigeration and pressure have thus far been unsuccessful. The commercial article is somewhat modified by the addition of water to prevent its ready decomposition under the influence of a warm temperature. For the same reason it is advisable to always keep it in a cool place. LIGHT BLUE. I. To dye this delicate color well, special care must be taken in cleaning the feathers, for which purpose only olive-oil soap of the best quality, with a little ammonia, ought to be employed. When they are perfectly clean and no more grease upon the stems, rinse them first in one or two lukewarm waters, then in cold water until the last trace of soap is removed. Then fill your basin or dyeing pan three-quarters full of cold water; put in, for a dozen feathers, one hundred and eighty grammes (about eight ounces) of raw starch in a sufficient quantity of good indigo extract to give the starch-bath the desired shade. Enter the feathers and work them gently until they are completely dyed, that is, for about fifteen or twenty minutes. Then take them out, squeeze out the starch by putting them between the fingers and thumb of your hand, and shake them before the stove, or in a well-warmed chamber until dry. While drying, beat them from time to time upon the board, or between the hands to remove the adhering starch. II. Prepare a lukewarm bath acidulated with a few drops of sulphuric acid, so as to give a faint sour taste, to which add, according to shade, solution of methyl blue B. (Actien Gesellschaft fuer Anilin Fabrikation, Berlin). Enter the feathers and leave them in the bath until cold, or until uniformly dyed. NOTE.--Some dyers use alkaline blue, which is not, however, recommendable, because alkaline baths, as above remarked, are injurious to the feathers and must be avoided as much as possible. III. Prepare bath of lukewarm water, dissolve in it about one-half ounce tartaric acid per one quart, and add one ounce indigo carmine per quart of liquid; stir well, enter the feathers and agitate or lay down in the bath until the required shade is obtained. This color shows little fastness to light and air, which can be improved, however, by adding to the dye bath one-quarter ounce alum per quart. The shade being obtained, take up the feathers and pass, without rinsing, through raw starch milk, dry and beat as described. Light blues, as is easy to understand, can only be dyed upon white feathers for the most delicate shades; nearly white, or developed gray feathers may be used for the shades approaching a light medium blue. NAVY BLUE. I. For this color naturally gray or semi-bleached feathers may be used. It requires a mordant, like wool. For this purpose prepare a bath of forty per cent. (of the weight of feathers) tannin at 167° F., enter the feathers and agitate them from time to time for three hours. Then take them up, drain and squeeze them out, enter a cold bath of pyrolignite of iron (black liquor) marking 5° B., and work them for half hour; take them out, drain and squeeze, and then expose them, well spread out upon the strings, for one hour to the action of the air. Then rinse and dye upon a fresh warm bath with a mixture of aniline blue and a little methyl violet, using about twenty per cent. of the weight of feathers. Add the dyestuff in the beginning only in small doses and slowly in order to prevent the production of a bronzy, undesirable lustre upon the stem, as is often the case in dying with aniline dyestuffs if they are added to the bath in too large doses. II. Prepare a hot bath, to which add as much indigo carmine as to bring the color of the bath pretty near the shade to be produced. Enter the feathers and agitate them in the bath for one hour. Then take up the feathers, add alum and a solution of cloth-blue S. to the bath, re-enter the feathers and work them while raising the temperature to boiling point, when the steam or gas is turned off, or the pan removed from the fire, and the feathers allowed to lie for fifteen or twenty minutes longer in the bath. They are then taken out, rinsed, starched and dried and beaten. III. Have the feathers properly cleaned and well rinsed from the soap, respectively soda. Gray feathers may be used unbleached, but a purer color is obtained upon them when bleached. Prepare a hot bath, to which so much sulphuric acid is added, that it has a feeble sour taste; add the solution of two per cent. (of the weight of feathers), navy blue, one per cent. fast blue or black, and one-eighth per cent. acid fuchsine. Stir well, enter the feathers, manipulate while raising the temperature to boiling point, but not to actual boiling, continue at this temperature for one half hour; then stop off the steam, lay the feathers down in the bath until cool, lift and dry as usual. GENDARME BLUE. This color requires a pure bottom, that is, naturally white or bleached. After cleaning, respectively washing in warm soap, which must not even be omitted with bleached feathers, and thorough rinsing, prepare a bath and dye as for dyeing light blue with indigo carmine. Then add some aniline green and navy blue to the bath, re-enter the feathers which have been taken up before making the addition, work them well while raising the temperature to the boiling point; continue at this temperature for one-half hour longer, lift, rinse, starch and dry as usual. PLUM OR PRUNE. I. For this color, which has in itself a subdued tone of brown, or has the color of gray ostrich feathers, such naturally colored feathers may be used unbleached, but well cleaned and rinsed before dyeing. Prepare a luke-warm bath, to which add about one-half ounce tartaric acid to per quart of water and solution of methyl violet 6 B., according to shade, with a little aniline ponceau or fast brown for toning. While working the feathers, raise the temperature and continue dyeing at nearly boiling for one-half hour; then take out, wash and dry. Or, II. Prepare a boiling hot bath with alum, sulphuric acid and tartar; to which add acid fuchsine; enter the feathers, and dye one-half hour to a blue red, which tone, by the addition of decoction of logwood, continue at nearly boiling heat for one-half hour longer, lift, rinse lightly, starch, beat and dry. III. Take a hot bath, upon which violet has been dyed, and refresh it with some solution of methyl violet, 5 B., and a few drops of sulphuric acid, or prepare a hot bath with the same ingredients, and indigo carmine, according to shade; or, instead of indigo carmine, indigo substitute, fast blue B. A., and indigotine; preferably, however, use indigo carmine, which develops more slowly, and therefore is surer to give better results, while the aniline dyestuffs run up more rapidly, and are apt to dye unevenly, unless their solutions are added gradually and the feathers handled quickly and carefully. LIGHT YELLOW. I. Light yellow is comparatively very little in demand for ostrich feathers, and scarcely used for trimming hats of children and young misses as a set-off for other colors. To produce it, prepare a pretty hot bath with a little sulphuric acid, so as to give it a slightly acid taste, add very little quinoline yellow, lay down the feathers in the bath for one-half hour, turning and agitating them from time to time, lift, rinse and dry. For this color, as well as for light blues and roses, the feathers must be perfectly white. (For this dye the quinoline yellow manufactured by the Actien Gesellschaft fuer Anilin Fabrikation, Berlin, is specially suitable). As the purity of all light shades of delicate colors greatly depends upon the purity of the water, it is advisable to bring the bath, before preparing it, to boil with some bran and chloride of tin and skim it off well. MEDIUM YELLOW. Various shades of yellow can also be produced with the old natural dyestuffs, which are not, however, equal in brilliancy to the foregoing described colors. The feathers must be bleached for these as well as for any clear color, which would be materially impaired by an impure bottom; still developed grays may be employed. After scouring and thoroughly rinsing the feathers, prepare a cold bath of alum, about one ounce to one gallon of clear water, or of acetic acid; lay the feathers down until well opened, so that the liquid can uniformly act upon all parts, for one hour. Then take them out, squeeze and centrifugate them, and dye the shade upon a fresh warm bath with the required quantity of flavine, decoction of color or of fustic; lift, rinse and starch as usual. Or, dissolve a sufficient quantity of turmeric in boiling water, filter and enter the feathers while the filtrate is still well hot. Agitate them for five minutes, then take them up, add to the bath a small quantity of tartaric acid, this to promote its dissolution; then re-enter the feathers, work them again for five minutes, lift, rinse in cold water, and dry. If these colors are to have a light reddish or warmer tone, add, when nearly done, some anotto to the dye bath. DARK YELLOW. Bleached grays answer for this color as well as naturally white feathers. Scour and rinse them well. Prepare a bath, feebly acidulated with sulphuric acid, and add the filtered solution of two and one-half per cent. of the weight of feathers, dark yellow, (manufactured by the Leipziger Anilin Fabrik, formerly Bayer & Kegel). Enter the feathers in the cold and work them diligently until the color is well up, then raise the temperature slowly to 170° F., dye to shade, lift, rinse in clear cold water, starch and dry. II. A new light yellow, which is fast to light and air, is obtained by products of Leonhardt & Co., at Manheim, viz: redarine and acme yellow. Add to a hot bath of 170-190° F., a quite small quantity of redarine and still less acme yellow; enter the feathers, manipulate for one-half hour, take out, rinse and dry them with starch, and beat well out. This color being extremely sensitive, the purification of the water for the bath is as necessary as the most scrupulous cleanliness of utensils and workshops. GOLDEN YELLOW. I. The feathers being scoured and rinsed clean of soap, prepare a bath of five per cent., of the weight of feathers, bisulphate of soda, add solution (filtered) of azo orange, according to shade. Enter the feathers at 120° F.; heat up slowly to 170° F., while working the feathers; lift when the shade is obtained, squeeze out, starch and dry. II. Prepare a bath with three per cent. (of the weight of the feathers) Glauber salt and one per cent. sulphuric acid. Enter the feathers at 100-120° F., after adding to the bath the solution of one per cent. golden yellow S. (of Gust. Doerr, Frankfort-on-Main), work the feathers repeatedly during one-half hour, when they all have assumed a rich, nourished color; take up, rinse lightly; starch and beat them dry. OLD GOLD. Have the naturally white or decolorized gray feathers well washed in soap and rinsed clean from it. Prepare a hot bath at 170° F., to which add so much aniline cream as to color it dark reddish yellow. Enter the feathers and agitate them from five to ten minutes, according to the shade desired. Then take them up, add some sulphuric acid to the bath, re-enter the feathers, work for two minutes; then lift, rinse and dry. The bath can be preserved for further use. GRAY. So unpretending this color appears, so difficult is it to produce, and it requires a considerable amount of practice and good judgment to bring out a good color from the beginning, as very little too much or too little will spoil a color either in tone or in shade. A very good logwood gray, which with proper attention seldom fails to turn out satisfactory, is made as follows: Prepare a hot bath, to which add a small quantity of decoction of logwood; enter the feathers and work them in the bath for fifteen or twenty minutes, according to shade desired. Then take them up, add to the bath very little pyrolignite of iron, that is, only as much as to turn the color of the bath; re-enter the feathers, agitate them again for fifteen or twenty minutes in the liquid; then lift, rinse and starch as usual. This color might be best described as dark ash gray. Instead of pyrolignite of iron, some solution of copperas may be used. It will be easily understood, that the more concentrated the decoction of logwood is, the darker turns out the color, and it is in that respect particularly that the dyer has to use good judgment in producing shades from silver gray to dark ash gray. This color, besides, presents the advantage, that by topping it with solutions of blue, brown, yellow or green coal-tar dyestuffs a great variety of mode colors can be produced. PEARL GRAY. After scouring and rinsing well, prepare a warm bath (100-120° F.) with five per cent., of the weight of feathers, bisulphate of soda, to which add solution of Victoria blue and of extract of archil, according to sample. Acid violet may be used, but requires a temperature near the boiling point, which ought to be avoided wherever possible in dyeing ostrich feathers. To be on the safe side, make the solutions of the dyestuffs of medium concentration, use only the clear of them, or better filter the same, and add it slowly and gradually first in small doses, finally by drops, for which purpose the use of a burette with squeeze-cock is recommendable. SILVER GRAY. Scour, respectively bleach, and rinse the feathers well clean, prepare a bath, work the solution of five per cent., of the weight of feathers, silver gray (Actein Gesellschaft fuer Anilin Fabrikation, Berlin), feebly acidulated with sulphuric acid; enter the feathers in the cold, work well to make the color dye up evenly; then raise the temperature slowly under diligent working, to 170° F., continue at this temperature for five to ten minutes, lift, rinse and dry. BROWN. The series of brown colors, partly produced by combinations of spectrum colors, partly of direct brown dyestuffs, presents a large range of modifications and shades, from a light rust brown or buff to nearly black, blueish, yellowish, reddish, olive brown, etc., and is in this respect only inferior to the non-descript endless variety of modes. With the exception of the very lightest shades, which require perfectly white feathers, they can be dyed upon half-bleached, and the deeper shades upon unbleached gray feathers; the dyer, must, however, in the latter case, bear in mind, that the gray bottom color always influences to a certain degree, the tone of the color that is to be dyed upon it. Nevertheless, as to the proportions of the dyestuffs to be employed for a given tone or shade cannot be given, because the tinctorial value of artificial dyestuffs is very changeable and not even constant with the same makers. Experience, skill and trial dyes must, therefore, guide the dyer in composing the baths for browns as well as for modes, the majority of the latter being modifications of brown. In general the following may be observed: I. After scouring the feathers and rinsing them perfectly clean of the scouring material, whether soap or soda, prepare a bath of 170 to 190° F., to which add fifteen per cent., of the weight of feathers, bisulphate of soda, indigo carmine, extract of archil and azo yellow. According to the proportionally greater or smaller quantity of either dyestuff added to the dyebath either browns are obtained, or olives, Russia green, reseda, or a variety of modes. The trouble with all colors into whose compositions indigo carmine enters is, that this dyestuff requires a comparatively high temperature to run up, preferably a boiling bath, which, however, is decidedly objectionable with ostrich feathers. To avoid this difficulty, the new acid Victoria blue is used instead of indigo carmine, and fuchsine S. instead of extract of archil. Victoria blue dyes up readily at a moderate temperature. II. The feathers being scoured and rinsed clean, prepare a boiling bath with so much sulphuric acid as to give a feebly sour taste, and add fast aniline brown, turmeric, and indigo carmine or cloth-blue S., according to the tone and shade desired. Prepare the bath so that it shows exactly this tone of color which is to be dyed, and bring it to boil in order to produce a perfect mixture of the three dyestuffs, or rather their filtered solutions. Then chill the bath to about 120° F., enter the feathers, while raising the temperature in about fifteen minutes to near the boiling point; then dye to shade, lift, rinse and dry. It is advisable, in order to obtain a level dye, to add not the whole amount of dyestuff solution required at one time, but at least in two times; which rule altogether applies to all aniline dyestuffs, more or less, as they mostly run up very rapidly and are apt, therefore, to give uneven dyes. If a yellowish tint is wanted, use a little azo yellow or azo orange; picric acid, which was formerly very freely used for this purpose, has been almost entirely abandoned. LIGHT BROWN. Clean and rinse them as usual, prepare a bath of 170-190° F., with redarine, a trace of orange O, and some acid green; enter feathers and work for one-half hour, then lift, rinse and dry. By varying the proportions of dyestuffs, a series of modes is obtainable. (Dyestuffs manufactured by Leonhardt & Co., of Mannheim). RUST BROWN. Prepare a slightly acidulated warm bath with three per cent., of the weight of feathers, fast aniline brown, one per cent. azo yellow, one percent. extract of indigo, and a little sulphuric acid; enter the well scoured and rinsed feathers at 120-140° F., work the feathers for one-half hour, while slowly raising the temperature to the boiling point; continue dyeing at that degree of heat, but not boiling, for five minutes; lift, rinse, starch and dry. RED BROWN. I. Scour and rinse well; prepare a warm bath, in which dissolve three per cent., of the weight of feathers, alum, add twenty-five per cent. extract of archil, one and one half per cent. azo yellow, and if required for shade, one-half per cent. indigo carmine; enter at 170° F., dye to shade while slowly raising the temperature to near the boiling point, continue at that temperature for ten to fifteen minutes longer; then lift, rinse and dry. Instead of indigo carmine, cloth-blue S. may be used, in which case enter at 120° and raise the temperature slowly, not above 190° F. Or, II. Prepare a bath at 190° F., add five per cent. bisulphate of soda, when dissolved, add solution of extract of archil, fast yellow and indigo carmine as required for the shade, and dye at that temperature to sample. Instead of archil, any red or orange azo dyestuff may be used, preferably bordeaux. COFFEE BROWN. Have the feathers will cleaned and rinsed, bleaching being not required, prepare a bath with three per cent. alum (of the weight of feathers), at 170° F., add indigo carmine, bordeaux and azo yellow, according to sample, and dye to shade while slowly raising the temperature to near the boiling point, but bring not to boil, but continue until the indigo carmine is well up. A less fast color is obtained with archil, indigo carmine and picric acid. When finished dyeing, rinse, starch and dry as usual. The dyestuffs for brown being nearly the same for all shades, while the depth and tone of the color is produced by differently proportioning the quantities of the different dyestuffs and the time of dyeing, it is advantageous to have the solutions of dyestuffs near by on hand; it is advisable, however, if good work is intended, to always filter before using solutions which have been standing for some time. This precaution is necessary, because from most solutions, if allowed to stand for a day or longer, some dyestuff which was not dissolved but only suspended in the liquid, separates out forming a more or less copious sediment which, if it passes into the dye bath, settles upon the feathers causing spots or streaks of a different shade than the rest of the feathers. PUCE. Scour and rinse the feathers well; grays can be used in their natural color without bleaching. Prepare a warm bath, in which dissolve eighty per cent., of the weight of feathers, tartaric acid and eighty per cent. Glauber salt; then add sixteen per cent. aniline fast brown; eight per cent. azo yellow, and sixteen per cent. induline or nigrosine, and bring the bath to a boil; after a few minutes of boiling, chill by the addition of cold water, enter the feathers and work them at hand-heat for fifteen or twenty minutes until the color has become level; then bring the bath again to near the boiling point; lay the feathers down in the bath, shut off the steam, or withdraw from the fire, and let the bath cool down. When cold, that is in about one or two hours, take out the feathers, rinse and dry. FAWN. Prepare a warm bath with five per cent. bisulphate of soda, add solutions of azo orange, acid violet and some archil cautiously in several doses until the bath has the desired color. Enter the scoured and rinsed feathers and agitate for fifteen or twenty minutes, to produce a level dye; then raise the temperature slowly to 190-200° F., dye for a few minutes longer, lift, rinse and dry. By varying the proportions of the dyestuffs, drab, wood brown, lead color, etc., can be obtained, and olives by increasing the quantity of acid violet and omitting the extract of archil. CHESTNUT BROWN. Scour and rinse the feathers well; natural grays may be used unbleached. Prepare a decoction of one and one quarter pound cudbear, and six ounces turmeric in two gallons of water, strain through a cloth and enter the feathers at hand heat (about 90-100° F.); work them for twenty or thirty minutes, or until they have attained a nourished garnet color. Then take them out, rinse, lay them down for five minutes in a cold solution of about six ounces copperas in one-half gallon of water, take them up and rinse in cold water. Then return to the first bath, operate for fifteen minutes at hand heat, enter again, after rinsing, the iron bath, and continue alternately dyeing upon the two baths until the required shade is obtained. Rinse every time on shifting from one bath to the other, in clean water, and finally rinse well, starch and dry. HAVANNA. I. For this color it is advisable to use naturally white or bleached feathers, scour or wash them clean in soap and warm water and remove the soap by thoroughly rinsing in two warm and one cold waters. Prepare a bath slightly acidulated with sulphuric acid, to which add eighty per cent., of the weight of feathers, tartaric acid, eight per cent. azo yellow, six per cent. fast brown, and three and a quarter per cent. acid green. Enter the feathers at 100-120° F. and manipulate at that temperature for ten or fifteen minutes. Then raise the temperature to the boiling point (but do not boil), lay the feathers down in the bath for one-half to one hour, while the bath cools down, lift, starch and finish as usual. II. Prepare a bath slightly acidulated with sulphuric acid, bring to nearly boiling, add a concentrated solution of orange S. and some acid green, enter the feathers and dye to shade; then pass them through a week oil-bath, and dry them, placed straight between several laps of clean muslin. III. Prepare a bath of the decoction of twelve and a half per cent., of the weight of feathers, alum and twenty-five per cent. turmeric; strain, enter the feathers at 170-190° F., and let them lie in the bath over night. On the following day dye, at 100° F., with decoction of fustet, tone with decoction of logwood or of brazil, according to sample, starch and dry. MUSHROOM. I. For this elegant color take naturally white or bleached gray feathers, scour and rinse them well. Prepare a hot bath with five per cent., of the weight of feathers, bisulphate of soda, to which add, as required, filtered solutions of fast yellow, indigo carmine and ponceau G. Enter the feathers at 170° F., work them for ten or fifteen minutes and raise the temperature slowly to near the boiling point. Add the dyestuffs in small quantities gradually, making the additions only when the dyestuff of the bath has been completely absorbed, and then by drops so as to be able to correct the color without waste of dyestuff. Bear in mind, that the indigo carmine dyes up slowly and requires a high temperature. An easier process is, therefore, the following: II. After cleaning and rinsing well, prepare a bath at 170° F., with four per cent. bisulphate of soda, to which add gradually in small quantities, as required, some nigrosine, azo orange and a little mandarin or nigrosine, alkaline blue and fuchsine S., rinse, starch and dry. LIGHT DRAB. Scour and rinse the feathers as usual; bleached grays may be used. Prepare a bath with five per cent., of the weight of feathers, bisulphate of soda and the clear solutions of acid violet, azo orange and fuchsine S.; add the dyestuff in small portions and finally by drops, until the bath has the desired shade of color; then enter the feathers and dye at 170° F. to sample, squeeze or centrifugate, starch and dry. BEIGE. I. For this color take either naturally white or well-bleached gray feathers, scour or wash and rinse them clean. Prepare pretty thin solutions of aniline orange (chrysaniline) and violet, add very little of them at a time and finally by drops to the dyestuffs containing either five per cent. bisulphate of soda or a small dose of sulphuric acid; enter the feathers at 145° F. and dye to shade at the same temperature, which will require about twenty or thirty minutes; lift, rinse, squeeze and starch. II. Have the feathers well cleaned, respectively, bleached, and rinsed. Prepare a hot bath (170-190° F.), with a little sulphuric acid, just enough to give it a slightly sour taste, add a few drops of solution of fast brown and a little more solution of acid green (both dyestuffs of the Farbwerke, formerly Meister, Lucius & Bruening, Hoechst-on-Main); take of them one or two drops, respectively two or three drops per gallon of water for a light shade and increase quantities proportionally for darker shades. Rinse after dying, starch and dry. III. Take white feathers or grays very well bleached to nearly white, scour and rinse them well. Prepare a bath of warm water, 100-120° F. and some vinegar so as to give it a distinct sour taste; add to a basin full, or about one-half gallon of the bath a little solution of fast brown, one or two drops of indigo carmine, and a trace of turmeric. Lay the feathers down in the bath for fifteen or twenty minutes and agitate them repeatedly in the liquid to make them level. For a Gray Beige, add a little nigrosine to the bath and proceed as above. MODES. For the modes it is impossible to give generally applicable directions, as these colors are of an indefinitely varying character, consisting in modifications of other compound or mixed colors which are affected by sometimes very trifling, unmeasureable additions of a toning dyestuff, and coloring effects are produced which cannot be described nor defined by names, but must be judged by the experienced eye of the dyer. Most of these colors are derived from grays or browns as above remarked, and the safest way for the dyer is, to begin dyeing with light shades of the prevalent characteristic color and give them the peculiar tone by the addition of other colors by drops. The proportions of dyestuffs thus ascertained for light shades, are then easy to increase for deeper shades. It needs not to be remarked, that for these colors the feathers must be bleached, especially for light and medium shades, and that, if unbleached, grays are to be dyed in dark shades, the effect of the natural color must be considered in composing the dye. In general all modes are dyed upon a bath which is acidulated with bisulphate of soda, with azo orange, azo yellow, azo brown, acid violet, indigo carmine, solid blue or cloth blue, induline or nigrosine, archil or acid fuchsine. For brown modes, solution of Bismarck brown may be added at the beginning, in which case the other dyestuffs serve only for giving the peculiar tone. For a yellowish green mode take orange O, azo yellow, and solid blue (fast blue); for darker shades add a little violet 6 B., or a few drops sulphate of indigo. If alizarine dyestuffs are to be employed, use tartaric acid as mordant, but for neutral dyestuffs add also a little alum to the dyebath. For gray modes use the same dyestuffs as above, excepting the orange, instead of which a blue-red dyestuff is to be employed, such as azo rubine, bordeaux, fuchsine, etc., with the addition of a little acid green. The bath must be acidulated with a little sulphuric acid, or better with tartaric acid, or tartaric acid and alum, and after dyeing the feathers must be rinsed, starched and dried as usual. For particularly fast modes add only tartaric acid to the dyebath and no alum, and a few drops of solution of thio-scarlet, thio-rubine, and thio-brown; for grays add a little azo yellow and sadden with solid blue. Alum does not agree with the thio dyestuffs which are manufactured by Dahl & Co., Barmin, and are fast against soap and light. Feathers dyed with these dyestuffs which have become soiled, can be washed, therefore, with neutral soap without injury to the color, but must naturally be dressed anew. RESEDA. Scour the white, respectively bleached feathers and rinse well. Prepare a bath with five per cent., of the weight of feathers, bisulphate of soda, to which add gradually and carefully the filtered solution of acid violet, fast yellow and fuchsine S., making the additions from the beginning in small quantities only, until the desired tone and shade are obtained; then enter and work the feathers to sample at 173° F. It is for this dye particularly important that the bisulphate of soda used be crystallized, that is, pure bisulphate free from surplus sulphuric acid, while the commercial article is often nothing but a mixture of Glauber salt (sulphate of soda) into sulphuric acid, answer for this dye. A good reseda is also easily obtained by adding to the acidulated bath small quantities of decoction of logwood and turmeric, so as to give a feeble bath. Enter the scoured and bleached feathers, after rinsing, at 170° F., work them for about fifteen minutes, until level, and sadden with a little solution of blue stone. Rinse, starch and dry as usual. ORDINARY GREEN. For two and one-half pounds of feathers boil two and one-half pounds of fustic for one-half hour with three quarts of water, pour the decoction off and boil the chips again for one-half hour with three quarts of water, mix the two decoctions and strain. Add three ounces alum and one and one-half ounces tartar, enter the feathers well scoured and rinsed, and dye to shade at 170° F. Or, prepare the dyestuffs of decoction of fustic or turmeric, and indigo carmine, according to shade, enter at 170° F., work for one-half hour while slowly raising the temperature to near the boiling point, and dye to sample; lift, rinse, squeeze and starch as usual. LIGHT GREEN. I. Scour, respectively bleach, and rinse the feathers. Prepare a hot bath with the solution of forty per cent., of the weight of feathers, tannin, and treat the feathers in it for 1 hour at 170°F. Prepare a bath with a filtered solution of methyl green, according to shade, tone, if a yellowish green is wanted, with the clear solution of picric acid, and dye to sample at 150° F. Lift, squeeze and starch without rinsing. II. A better color is obtained upon a lightly acidulated bath (with sulphuric acid) with acid green, malachite green, fast green, etc., that is, with the filtered solutions of these dyestuff's, added to the bath in quantities of from ten to twenty per cent. to suit the shade. Enter at 170° F.; dye for twenty or thirty minutes, lift, rinse, squeeze and dry with starch. If a yellowish tone is wanted, add the clear solution of picric acid, or of acid yellow. MOSS GREEN. Scour and rinse the feathers well; for dark shades unbleached grays may be used. Prepare a feebly acidulated bath with sulphuric acid, at a temperature near the boiling point; add turmeric freely and Guinea green G less. Enter the feathers and manipulate at the same temperature for fifteen or twenty minutes, according to the desired tone, re-enter and dye to shade. By varying the proportions of the three dyestuffs, a great variety of green-brownish modes can be produced, which approach medium and dark bronzes the more the fast brown predominates in the composition of the color. BOG GREEN. This color is preferably dyed upon unbleached gray feathers. Scour and rinse them, prepare a decoction of green walnut husks or of sumac; lay the feathers down in it for two hours, working them from time to time; then add some decoction of logwood and dye to shade at 170° F., or indigo carmine and dye to shade while slowly raising the temperature to near the boiling point. Rinse, squeeze, starch and dry. GRASS GREEN. Scour, respectively bleach, and rinse the feathers. Prepare a boiling bath with turmeric and indigo carmine; chill, enter the feathers at 170° F., dye for one-half hour, raise the temperature slowly to near the boiling point and dye to shade, take up, rinse and pass through a handwarm bath of tartar; lift, squeeze, starch and dry. RUSSIA GREEN. I. Scour the feathers as usual and rinse well. Prepare a bath slightly acidulated with sulphuric acid, add two per cent., of the weight of feathers, acid green and one per cent. aniline navy blue dissolved in warm water and filtered acid, according to sample, some filtered decoction of turmeric or solution of fast yellow. Dye at 170° F. to shade, lift rinse and dry with starch. II. Have the feathers well cleaned and rinsed. Prepare a bath twenty per cent., of the weight of feathers, new green, eight per cent. canarine, sixteen per cent. aniline blue black, sixty per cent. alum, and one-quarter litre sulphuric acid (for two and a half pounds of feathers). Bring the bath to a brisk boil, then chill with cold water, enter the feathers and work them for one hour; finally sadden and tone by adding some decoction of fustic and of logwood. Lift, rinse, squeeze, starch and dry. III. Prepare a sharp hot bath with a little sulphuric acid; add Guinea green, according to shade, and tone by the addition of indigo carmine and turmeric; for very deep shades add also some nigrosine or fast blue-black, dissolved and filtered. Enter as hot as the feathers can be handled, work for one half hour; then raise the temperature slowly to near the boiling point and dye to shade. The bath for deeper shades being not exhausted can be preserved for further use, refreshed by suitable additions of dyestuffs as required, but caution must be used as regards the subsequent additions of sulphuric acid, that not so much be added as to injure the feathers. For Russia green, especially the darker shades of it, naturally gray and even black feathers can be used unbleached. ROSE. I. For this delicate color, as well as for the lightest shades of blue and pure yellow, absolutely white feathers must be used; scour them carefully and rinse them perfectly clean from soap or soda, and have the dyestuffs well dissolved and the solutions filtered. Prepare a handwarm bath with a little tartaric acid or acetic acid, to which some solution of eosine, rhodamine, azoeosine, safranine, coccine or ponceau 6 R. B. or ponceau R. R. Be particularly cautious in adding the dyestuff solutions gradually in small quantities, even by drops, to avoid over-dyeing, as by partly stripping of a too dark shade, a fine color can never be obtained, and the nature of the material demands that all unnecessary handling be avoided. After dyeing, rinse lightly, pass through starch and dry. The dyes with the ponceaus are faster than those with eosine or safranine. II. Prepare a bath at hand heat with carthamine (extract of safflower), well dissolved and filtered, which add very gradually in small quantities, taking up the feathers each time before making a fresh addition, until the desired shade is nearly obtained, then add a little tartaric acid to the bath, re-enter the feathers and dye to shade; or dye first to shade upon the safflower bath, and then pass through a fresh, handwarm feeble bath of tartaric acid, which in this case can be used again for other colors, either as a fixing bath or in the composition of the dye bath. RED. Scour and rinse the feathers well; grays must be bleached as near to white as possible, and these ought only to be dyed dark shades of red. Prepare a bath with twenty per cent., of the weight of feathers, bisulphate of soda, and see, as in all cases, that it is well crystallized and dry. (Never use the article when it looks decayed, forms lumps or is moist). Add four to six per cent. azo red, according to the shade wanted, raise the temperature to 170° F., enter the feathers and work to shade; take out, starch and dry. FAST ALIZARINE RED. I. Scour and rinse the white, respectively bleached gray, feathers and prepare a bath of boiling water with eight per cent., of the weight of feathers, alum, four per cent. tartaric acid, two or three per cent. oxalic acid, and three per cent. alizarine red; let the bath boil for fifteen minutes, then let the temperature go down just below the boiling point. Lay down the feathers in the bath, which keep at near the boiling point for at least one hour before allowing it to go down to hand-heat; then continue for two or three hours longer, agitating the feathers from time to time; lift, rinse, starch and dry. By using alizarine acid 2 A. bl. bl., a pure red, similar to Turkey red is obtained. Alizarine 1 W. S. gives scarlets. If the feathers are passed, before rinsing, through a strong soap bath, pretty blue tones are produced. II. For a fuller red, striking towards bordeau, prepare a well concentrated boiling bath in the same manner with three per cent. bichromate of potash, one and one-half to two per cent. tartaric acid, one per cent. oxalic acid, and eight per cent. alizarine red 2 A. bl. bl. When all is dissolved, let the temperature go down below the boiling point, enter the feathers, and proceed as above. SCARLET. I. For this color naturally white feathers are preferably used, but well bleached grays may also be employed; scour and rinse well. Then fill your pan with boiling water, add a few handfuls of bran, let it well boil up, remove the bran from the bath and rub the feathers in the bath as in washing; then pass them three times through clean, cold water. While the feathers are draining, prepare another fresh bath of lukewarm water, to which add a little chloride of tin and, for one pound of feathers, about two pinches of starch and ninety grammes cochineal; then bring the bath to boil and let it gently boil for eight or ten minutes, shut off the steam or remove the pan from the fire, let it stand for a few minutes. Then lay the feathers down in the bath, taking care that they are well kept down in the liquid, work for twenty minutes diligently, then let them lodge in the bath for six to eight hours. As the combination of cochineal and the chloride is readily oxydized and changed to violet by the oxygen of the air, it is advisable to dye in a tinned pan with cover to shut out the air. Then pass through three lukewarm waters, the last of which contains a little chloride of tin and about a pinch of cream of tartar. II. Prepare a hot bath with twenty per cent. (of the weight of feathers) bisulphate of soda, well crystallized and dry, and four to six per cent. azo red, according to shade. Enter the feathers at 170° F., dye to sample in fifteen or twenty minutes, lift, starch and dry. According to the brand of azo red which is used, either scarlet or ponceau is obtained. By mixing the various brands of azo red, a very fine ponceau is produced. If a very blue tone is desired, add to the bath some solution of coccinine (azo red blue touch). PONCEAU. I. Scour and rinse the white, respectively bleached feathers well. Prepare a nearly boiling bath, acidulated with sulphuric acid, to which simply add ponceau R. R. extra. Enter the feathers, operate at boiling heat one-half hour, then lay down the feathers and let them lodge until level; lift, rinse, starch and dry. II. Prepare a sharp handwarm bath with one per cent. tartaric acid (of the weight of feathers), or with one per cent. Glauber salt and one-fourth per cent. sulphuric acid, to which add the filtered solutions of ponceau R. B., ponceau 6 R. B., and eosine S. extra B. Enter the feathers and agitate for twenty to thirty minutes, or until the desired shade is obtained; lift, rinse, starch and dry. III. Lay down the feathers for four hours in a cold bath in which some chloride of tin has been dissolved; then dye for one-half hour in a hand warm bath of cochineal, lift and dry. IV. Prepare a bath with one and one-half per cent., of the weight of feathers, saccharic acid, one-quarter per cent. tin salt, and six to seven per cent. cochineal, bring the bath to boil for one minute; then chill. Enter the scoured and rinsed feathers at hand heat, dye for three-quarters of an hour, take up and expose them for two hours to the air, rinse, starch and dry. BORDEAUX. Scour and rinse the feathers well. Prepare a boiling hot bath slightly acidulated with sulphuric acid, to which add a liberal quantity of ponceau 6 R. B., a few drops solution of aniline blue, and some yellow dyestuff, such as turmeric, fast yellow, or quinoline yellow, and bring the bath to boil for a few minutes. Then chill to sharp hand-heat, enter the feathers and work until level, and sample; if still too light, add some more of all these dyestuffs. As the bath shows from the beginning the color it will produce, it can be corrected before entering the feathers. GARNET (RED). I. Scour and rinse the feathers well clean, grays ought to be bleached. Prepare the dyebath as for ponceau (I.), or use an old ponceau bath, and add to it some aniline cerise (cherry red) and very little extract of indigo, or solution of fast blue-black. Enter feathers as hot as possible to handle, work for fifteen to twenty minutes while raising the temperature to boiling heat; then stop heating, lay down the feathers, and let them lodge until level; lift, rinse and dry. II. Prepare a boiling hot, not boiling, bath of anotto, according to shade, enter the feathers, work them well through, then lay them down in the bath for twelve hours. Take them up, rinse, pass through a moderately strong alum bath, rinse again, and dye at 170°F., with either decoction of red wood (brazil, camwood, etc.,) or fuchsine; lift and dry. GARNET (BROWN). For very deep shades naturally gray feathers may be used unbleached with proper consideration of the tone of the bottom color. Have the feathers well cleaned and rinsed, and add to a bath of two gallons of water, one and one-quarter pounds cudbear and five ounces turmeric. Bring the bath to boil, boil for five or ten minutes, let cool down to 100° F., enter the feathers and dye to shade. Lift, starch and dry. Or, utilize a used ruby bath (following) and add to it five ounces turmeric. RUBY. For a good color the feathers must be white, naturally or bleached; scour and rinse them well. Add to two gallons of water one and one-half pounds good cudbear, stir well, enter the feathers and work them, while slowly heating, as long as the hands can stand it. Then lay them down until colored to shade, lift, rinse well, starch and dry. SALMON. I. Salmon or "flesh" may be dyed upon bleached naturally gray feathers, in which case the creamy tint of the feathers must be taken into consideration and can be utilized for certain broken tones of the color. Have the feathers well washed in soap or soda, and rinsed perfectly clean. For dyeing prepare a bath as for rose, preferably with ponceau B. R., or utilize an old bath for rose, according to its strength and the shade to be produced, and add in either case a suitable, small quantity of filtered decoction of turmeric. Proceed as stated for dyeing rose, with the difference only, that the acid may be added to the dyebath at once, if the bath is made fresh. Particularly fine shades are obtained with rhodamine and turmeric, in a bath slightly acidulated with acetic acid, upon bleached grays. II. Prepare a bath as for rose, with some solution of eosine, a little quinoline yellow, according to tone, and a little acetic acid, just enough to give the bath a slightly sour taste. Enter the well cleaned, or bleached feathers after rinsing, at hand heat and agitate them until the bath is well exhausted, or a level color, according to sample, obtained, rinse lightly, starch and dry. AMARANTH. After scouring and rinsing, prepare a bath with one and one-half ounces alum per gallon of water, at 75-80° F., and lay the feathers down in it over night. On the next morning rinse them in cold water; then dye them at hand-heat to nearly boiling heat in a strained decoction of Brazil wood (or camwood, hypernic, etc.) until the required shade is obtained, and rinse in warm water to which some tartar has been added; starch and dry. BRONZE. For this color naturally gray feathers may be used if a deep shade is to be dyed; for light shades they ought to be bleached. Scour and rinse the feathers well; then prepare a bath with five per cent., of the weight of feathers, bisulphate of soda, to which add azo orange, acid violet and extract of archil. Dissolve the dyestuffs, each separately in water, filter, add the clear solutions gradually in small quantities until the shade is nearly reached, then, in order to correct, by drops, until the exact depth and tone are obtained. Enter the feathers and dye to shade at 170° F. Instead of acid violet indigo carmine may be used; in this case, however, as the dyestuff runs up slowly and difficultly, work at 170° F., for twenty to thirty minutes, then raise the temperature slowly to near the boiling point and continue at that temperature, without actual boiling, until the required color is obtained. Then rinse, squeeze, starch and dry. Bronze is also produced like drab, that is, with azo orange, acid violet and fuchsine S., but with greater quantities of dyestuff. Bronze is also obtained with the recipe for any dark brown, by making the yellow in it predominant; particularly good bronzes are in this manner obtained from dark chestnut brown. OLIVE. I. Clean the feathers by laying them down for six hours, or over night, in a weak warm solution of soda crystals (1° B.) to which add so much ammonia as to give it a faint odor; take up when completely ungreased and rinse well in lukewarm and cold waters. Prepare the dyebath with five per cent., of the weight of feathers, bisulphate of soda, to which add filtered solutions of indigo carmine, archil and fast yellow as required for the sample. As the indigo carmine is slow to dye up and requires boiling heat or a temperature near it, dye first the feathers blue with indigo carmine, then let the bath cool down to 170° F., and add the solutions of archil and fast yellow in small successive quantities, so as to be able to give the accurate tone. Instead of extract of archil, fast red or bordeaux may be employed. To avoid any possible injury to the feathers by the high temperature necessary for indigo carmine to run up, in its stead a solution of alkaline blue or of acid Victoria blue. Take up and dry the feathers without rinsing. II. Scour well and rinse the feathers, and prepare a bath with three per cent. alum (of the weight of feathers), to which add azo orange and some indigo carmine; enter at 170° F., dye for fifteen or twenty minutes, then raise the temperature slowly to near the boiling point and dye to shade. Lift and dry. By beginning with small quantities of the dyestuffs and successively increasing them and varying their proportions, a series of fine shades from light old gold to the deepest olive, near black can be produced. III. Prepare a boiling bath, in which dissolve one per cent., of the weight of feathers, alum, one per cent. Glauber salt, and add a little sulphuric acid; let cool down to 170° F., add some fast yellow, a little solution of archil and of sulphate of indigo, work for fifteen minutes while raising the temperature to the boiling point, and sadden with blue black, lift, rinse and dry with starch. IV. Prepare a sharp handwarm bath with a little sulphuric acid, to which add the clear solution of a little quinoline yellow or turmeric, and acid green; enter the feathers and work for fifteen minutes, or until they have taken a sufficiently nourished yellow-green color; then take them up, add to the bath some solution of fast brown, as required by the sample and dye at 170° F. to shade; rinse, squeeze, starch and dry. The brown dyestuff must be added very carefully in small doses, best by drops, in order to obtain with certainty any of the great varieties of shades, from olive green to olive brown, as required. VIOLET. Naturally gray feathers may be used unbleached, but only for very deep shades as the bottom color acts dulling upon the dye, and brilliant colors can only be obtained upon a pure white bottom. Scour, respectively bleach well, and rinse clean. Prepare a hot bath to which add some filtered solution of methyl violet, according to tone, that is, more or less blue, enter the feathers and work until cool, then add gradually more dyestuff solution according to shade while raising the temperature to near the boiling point and continue at this temperature until the desired shade is nearly obtained. If too blue, tone with a little solution of fuchsine S. Towards the end of the operation take up the feathers, add some alum to the bath, and when it is dissolved, shut off the steam, re-enter the feathers and work to shade for about ten minutes. Then lift, rinse and dry. HELIOTROPE AND LILAC. I. These colors being simply medium and light shades of violet, proceed as for the latter color, selecting for heliotrope the bluish brands of methyl violet, and for lilac the red touch mark. The dyebath is acidified with a little tartaric acid, so as to give it a feeble sourish taste and dyeing done at hand-heat until a level color is obtained with very little solution of the dyestuff, and more of it gradually added, while the temperature is raised to nearly boiling, as required for the shade to be produced. Or, II. Prepare the dyebath simply of cold water acidulated with a little sulphuric acid, add a few drops of the filtered solution of methyl violet (4 B. for heliotrope), and dye to shade without heating. In both cases rinse after dyeing, pass through a bath of raw starch and dye as usual. CREAM. I. The lightest shade of this delicate color can be produced upon naturally gray ostrich feathers by simply bleaching them; this color, however, is extremely sensitive, probably because the action of peroxyd of hydrogen continues under the influence of the oxygen of the air. Bleached grays require, therefore, dying as well as naturally white feathers. The feathers being well scoured and rinsed, prepare in a white basin (preferable to the copper pans, because the coloring of the dyebath is easier and more correctly discerned over the white bottom) a bath of pretty hot water, to which add a pinch of tartaric acid, and a little decoction of turmeric or solution of fast aniline yellow or of azo yellow, but only enough to give the water a light tint; work the feathers in it for four to six minutes. Then sample and correct, if necessary, by adding more dyestuff solution. The shade being obtained, pass through cold water, starch and dry us usual. II. Prepare in a white basin a handwarm bath with three or four drops of sulphuric acid and a few drops of the filtered solutions of picric acid, fast aniline yellow, quinoline yellow, or mandaric yellow extra, but preferably turmeric which dyes up more evenly than the other dyestuffs. Enter the feathers and agitate them for fifteen or twenty minutes; then lay them down in the bath for one-half hour longer to insure a level dye; lift, draw through lukewarm water, starch and dry. WHITE AND BLACK. Science teaches that white is the source of light or the product of combination of all other colors, because the light of the sun, which is assumed to be white, when broken up by means of a prism, shows in its image reflected upon a white plain, the three primary, and three secondary colors with the uncounted number of intermediary products of combinations of fractions of the primary colors forming the transition from one to the other, which can be perceived by the eye but not exactly separated from one another, but may quantitatively determined to an approximate degree of accuracy. Black, on the other hand, is described as the absence of all light, and it is denied, therefore, by theory a place among the colors. Practice asserts the direct contrary of the theory developed by science by way of conclusion. While philosophers assert that they have succeeded in producing white light by the combination of lights of the various colors, for which combination, however, they give no formula, no dyer with the greatest patience and with the most subtile proportioning of dyestuffs, giving pure reproductions of the primary colors as seen in the spectrum or image of the broken sunbeam, can ever be able to produce anything of a color approaching white. But every dyer knows how to produce white by bleaching, that is, by the destruction of all color. And this operation is comparatively simple and easy to perform, since the great achievements of modern chemistry have placed into the hand of the dyer the most energetic and effectious color destroying agents. The ostrich feather dyer of to-day is able to convert naturally gray and even black feathers into nearly pure white, which undertaking his father would have called the boast of a deranged mind and an absolute physical impossibility. And with the aid of a complementary color dyed upon the bleached feathers the tint remaining upon them is obliterated, or neutralized, which operation is generally called "white dyeing," although certainly white cannot be "dyed" with a blue or violet dyestuff as little as blue or violet can be produced with a yellow dyestuff. Black, on the other hand, although the name and rank of a color is denied it by the doctrines of theory is, for the dyer, most essentially a color requiring for its production the contribution of all colors, as can be shown by a simple experiment. If, for instance, within a circle, three equal circles, whose diameters are greater than half the diameter of the surrounding circle, are printed, one blue, one red and one yellow, so that the points of contact with the periphery of the outer circle are equidistant from one another, or form a regular triangle, their segments overlapping one another form four spherical triangles, one violet where red and blue cover one another, one orange where red and yellow come together, one green where yellow and blue are mixed, but the fourth is the centre, where parts of the three differently colored segments cover one another, is black, but toned by the color of the greatest intensity. In fact, black requires for its production more color, and is more difficult to dye than any color of the spectrum. It is not strange, therefore, that many more methods have been proposed and have been tried and adopted to dye black than for the production of any other color. Yet all these blacks are more or less tinted and are nothing more than the deepest shade, which can be produced with the aid of metallic salts, of blue, brown, gray, violet, green and even red. The only black upon ostrich feathers which may be justly called an absolute black is that produced after the method of Mr. Paul, as described in the front part of this book (page 53-56). It presents, besides, the advantage, that it can be completely done in eighteen minutes, while there are older methods which require not less than three days. Such, of course, will find no room here, but only the most reliable and expeditious, and safest of the older methods will be selected with due regard both to beauty of color and preservation of the precious material. WHITE. Naturally white ostrich feathers and bleached grays, like all material taken from the animal realm, retains even after scouring and bleaching a more or less noticeable yellowish tint, which becomes visible after some time even upon such as appear snow-white immediately after scouring. The cause is, probably, that the fat which is contained in feathers, as well as in wool and hair, and a part of which remains after the cleaning process, is oxydized by the action of the air. To perfectly and completely extract this remaining small amount of fat which does not hinder the subsequent dyeing operations, is not advisable; for, it has been observed that in that case, the feathers become brittle, and for this reason, scouring with soap is preferable to scouring with soda. It has been observed that colored matter taken from the animal body in the course of time loses its brilliancy of color and becomes dull; white feathers turn yellowish, even if perfectly protected against dust. To prevent this alteration, the bleached feathers are "dyed white," or rather blued or tinted; that is, the brilliancy of the white is heightened and the faint yellowish tinge neutralized by the application of a very light, scarcely perceptible tint of a complementary color. For this purpose, for instance, indigo carmine (greenish white), indigo carmine with a very small addition of ammoniacal cochineal (reddish white), induline or extract of indigo (bluish white), or methyl violet 6 B. (direct white), are employed, and a few drops of acid added to the bath, either sulphuric, acetic or oxalic acid. The acid, however, can be dispensed with, as it scarcely has anything to act upon, and as only a diminutive amount of it is employed, the blued feathers are not rinsed but immediately dried from the blue-bath. The additions of dyestuff to baths must be made so small that they do not affect a coloring of the feathers but only a faint tinting. Rather too little dyestuff may be added, which defect can at all times be corrected by adding a few drops more of the coloring solution, than too much. In the latter case it would become necessary to bleach the feathers again and go over the whole process of preparing the raw material for dyeing. BLACK. I. CHROME BLACK.--Black being the most difficult color to produce, as above remarked, the feathers require a specially careful preparatory treatment in order to remove everything that might interfere with the purity, uniformity and brilliancy of the color, or cause less dyed, dull spots and streaks. Naturally gray feathers, however, need not to be bleached or decolorized but only careful treatment and attention. The feathers are for twenty-four hours laid down in a solution of twice their weight of calcined soda, ammonia soda being preferable for this purpose to Lablanc soda (old process soda), then taken up and carefully rinsed clean from the alkaline in warm water, or better, in two warm waters. In the case of particularly valuable feathers it is recommendable, before laying them down in the soda solution, to rub the stains of the feathers off with a piece of carbonate of ammonia or with a large soda crystal. After rinsing, the feathers are entered for one hour, at 170° F., in a bath containing forty per cent., of the weight of feathers, chromate of potash, forty per cent. copperas, and twenty per cent. tartar, and several times turned and agitated during the specified period while the entering temperature is maintained. Then the feathers are taken up, and the adhering liquid squeezed out by hand or by rolling them through a clothes wringer with rubber roller. In the meantime a logwood bath of medium concentration is prepared either with a fresh decoction or with extract of logwood and twenty per cent. Marsailles soap dissolved in it. The feathers are entered in this bath at hand-heat, diligently agitated for twenty or thirty minutes and, if necessary, while the temperature is raised to 200° F., laid down in the bath until the correct shade and a level dye are obtained. The feathers are then lifted, squeezed, very thoroughly rinsed in cold water, passed through starch and dried with frequent shaking, respectively beating upon the board or between the hands. It occurs sometimes, that the stems of the feathers are imperfectly died and present light brown or gray places. This is attributable to insufficient scouring. In this case the defective portions of the stems must be scraped with a sharp penknife and dyed over. This operation, however, is difficult and requires much practice and a light hand, as too much scraping removes the horny glossy surface of the stem and, when dyed over, the only change effected is, that a dull black mark takes the place of the discolored or brown spot. Often, however, the defect can be remedied by touching the imperfect portions up with a feeble alcoholic solution of shellac, in which some nigrosine is dissolved. With properly scoured feathers this mishap does not occur. Another trouble, however, which is not unfrequent with blacks, is that the feathers are over-dyed and become brownish black instead of black. But in this case the remedy is as simple as its occurrence is frequent; a quick passage through sulphuric acid diluted with water to 2° B. strips off the excessive dye and produces a good color. Besides, this operation gives the feathers a brilliant lustre. Many dyers, therefore, methodically avail themselves of this effect of sulphuric acid and deliberately over dye their feathers (See IV below) and then apply the sulphuric acid passage for the purpose of imparting the feathers that peculiar lustre. A passage through a solution of sodium chloride, of 2° B. strength, has the same effect as a passage in sulphuric acid 2° B. For this purpose lay the feathers down in the warm sodium chloride solution, until the black cotton strings with which the feathers have been tied together, as in the beginning described, begin to turn gray. Then take up the feathers, rinse them very thoroughly in cold water, drain, starch and dry. Sodium chloride can be prepared in a simple way as follows: rub one-half pound fresh chloride of lime in a porcelain mortar with a little water into a smooth milk, which pour into a bucket, dilute with cold water, and add, under stirring, the solution of one pound Glauber salt; let settle and use the clear liquid. Instead of Glauber salt (sodium sulphate), soda crystals (sodium carbonate) may be used; the latter, however, is a little higher in price and renders the solution strongly alkaline. II. IRON BLACK.--Lay down the feathers over night in a warm bath, in which one hundred per cent., of the weight of feathers, soda crystals have been dissolved. On the following day take them up, squeeze them out and lay them down for two hours in a proportionally strong solution of carbonate of ammonia, take them up and rinse well in warm water. Lay down for six hours upon a bath of nitrate of iron 10° B.; take up, rinse, and dye at 170° F. with the decoction of ten per cent. logwood in which five per cent. Marseilles soap has been dissolved. If a dead black is wanted, add some decoction of quercitron or turmeric to the bath. The desired depth being obtained, lift, rinse, starch and dry. In case the color is over-dyed, strip with sodium chloride (or sulphuric acid) 2° B., as above described, drain, squeeze and dry. III. LOGWOOD BLACK.--Scour and rinse the feathers well. Prepare a bath with three per cent., of the weight of feathers, carbonate of lime, six per cent. blue stone, and five per cent. tartar. Enter the feathers at 170° F., maintain this temperature for one hour; then let it go down, but leave the feathers in the bath for six hours longer, agitating them frequently during that time. Take them up, drain and squeeze, or centrifugate, and enter a handwarm bath containing some decoction of logwood, to which some decoction of fustic is added. Work for fifteen or twenty minutes, then raise the temperature to nearly boiling heat. Continue adding decoction of logwood, until a nourished black is obtained. This dye being hard to correct by the ordinary means, the additions of logwood decoction must be made with caution towards the end of the operation, in order to prevent over-dyeing. If a brownish touch is desired, add some more decoction of fustic when the black is nearly done. Then lift, rinse, starch and dry as usual under continual agitation, beating and shaking of the feathers. This chrome black is superior to iron black, because it imparts, to the ostrich feathers, more lustre. IV. Whatever kind of feathers are to be dyed, white, grays or old blacks, wash them perfectly clean in two or three warm soap baths and remove the soap by rinsing in two or three warm and several cold waters. Colored feathers which are to be redyed blacks must be stripped of their color as much as possible by washing in hot soap to which some ammonia is added, whereupon this must be rinsed in several waters absolutely clear from soap and alkali; it is an erroneous notion to neutralize the last trace of alkali which may remain, by a passage through a feeble acid bath. The feathers thus prepared for dyeing, make a bath of two parts nitrate of iron to one part hot water at 170° F., enter the feathers, work them through a few times, and then lay them down in the bath for twelve hours (over night). Then lift and rinse the feathers in several (three or four) cold waters Prepare a pretty strong decoction of logwood and fustic, for which take two parts of the former to one part of the latter; let the temperature go down to about 208-210° F., when enter the feathers and maintain that temperature for fifteen or twenty minutes. Then shut off the steam or remove the dye-vessel from the fire, as the case may be, and let the feathers cool in the bath. When cold take them out, prepare a fresh bath of logwood and fustic like the first, enter the feathers at 208-210° F., after fifteen or twenty minutes add about a teaspoonful of copperas for one gallon of water, and leave the feathers in the bath for six or eight hours longer; then lift and rinse in several cold waters. The feathers are at this stage black with a strong brown touch which is removed by a cleaning bath of Eau de Javelle (sodium chloride). The latter is prepared by rubbing one-quarter pound chloride of lime to a smooth milk with a little cold water (in a porcelain or a marble mortar) and adding this milk to the solution of one-half pound Glauber salt in three parts water. After good stirring the mixture is then allowed to settle, when the clear solution is poured off and put up for use in well stoppered bottles. Of this liquid so much is added to a basin or pan full of warm water that it gives a slippery feel between the fingers, similar to that of a solution of soda. In this bath the feathers are agitated for six or eight minutes, or until the liquid has assumed a yellowish color. Then the feathers are taken out, rinse in two or three warm waters, passed through raw starch, pressed out between several laps of a clean piece of muslin, and dried either by rubbing them in pulverized and sifted potato starch or by shaking them before an open fire or gas-flame. The nitrate of iron bath can be preserved and used for the same purpose for eight or ten days, but the first logwood bath becomes useless and is let out. As above observed (I) sulphuric acid can also be employed for correcting the over-dyed feathers and reducing that brownish color to a pure lustrous black, but a much shorter passage is given: the feathers are entered by single strings, well opened, agitated in the sulphuric acid bath for a few seconds, and immediately rinsed. Where week work is done, it is advisable to have two men employed at this operation, one of whom passes the feathers in the acid bath and hands them over to the other man for rinsing. CONTRASTS AND SHADINGS, OR OMBREES. Fashion and fancy sometimes requires the dyer of ostrich feathers to dye upon one feather two, or even three contrasting colors, or different shades of the same color, that is, the tips of the feathers in another color or shade than that of the lower part of the feather. Generally in these combinations the tip is dyed the lighter color or shade, and the lower part considerably deeper or in a heavier color. Very popular combinations are: the tip light blue and the bottom brown, the tip rose and the lower part bordeaux, the tip light orange or dark yellow and the lower part garnet brown, tip rose with olive bottom part, or even three colors, such as the tip rose, the part below it medium olive green, and the lowest part deep violet. That such combinations are very handsome cannot be asserted; but fashion dictates, and fancy sometimes prefers oddity to beauty. More rational are at any rate the ombrées, or combinations of two or three shades of the same color upon one feather. The operation is the same for both styles; but contrasts are generally dyed only upon single feathers, while ombrées, being in greater demand, are dyed by strings or even in greater lots. The feathers being scoured and rinsed as usual, are first dyed wholly in the lightest color or shade to be produced, according to recipe, say light blue for the tip, and dried. Then wrap the top, as far as it is to be light blue, in paper (some dyers use for this purpose oiled or waxed paper) and tie the paper firmly, but not so hard as to injure the feather, with a string, not so loosely as to allow the paper envelope to slip out of place during the manipulation. Then, holding the feathers by the top, dip them into the boiling hot bath for the other color, or shade, to be dyed, but only so deep that the paper just touches the surface of the dye-liquid. This method is the safest for learners or new beginners. For more experienced workers it is unnecessary to use the paper wrapping; they simply first dye the light bottom shade, dry or not, according to the characters of the two colors (for shadings, half-dry feathers, that is, drained and squeezed out, are rather preferable), and loosely hold them in the bath for the second color, or deeper shade. They have it thereby in their power to effect a more gradual transition from one color or shade to the other. As the color becomes deeper, the longer the feather is immersed in the bath, it is plain that the dyer can easily produce upon one feather a complete graduated scale of shades. Each time, after a shade has been dyed to the required depth, the feathers are rinsed in cold water and some more dyestuff solution added to the bath. These additions require good judgment, because too much dyestuff added would cause an abrupt, dull contrast instead of a desirable gradual shaking off, or transition from one shade to the other. There ought only a little more dyestuff be added each time, than has been absorbed from the bath by dyeing the preceding shade. If paper wrappings are used, they must naturally be untied for rinsing and replaced by longer pieces before entering the bath for the following darker shade. After rinsing the feathers must always be well squeezed out. If two colors are to be dyed, for instance light blue tip with brown lower part, dye first the whole feather light blue, rinse, dry, tie up the tip in paper, and dye the lower half brown. It needs not to be mentioned that for dyeing two or three contrasting colors upon one feather only such dyes must be chosen as can serve for bottoming and topping one another without materially altering the character of the topping color. EDGINGS OR BORDERS. For this style of feather dyeing, use feathers of good quality, with wide and well developed vanes. They are dyed in two colors and shades only, presenting one color, mostly of a light shade, or a white "black" on both sides along the stems, while the outer edges for the vanes, or ends of the fibres, are dyed in a different color or darker shade. They make a particularly handsome effect when curled over the stem, setting off the edges in a fine contrast against the black showing through the curls. To produce edgings an oval pan, as described in the beginning, or other dye-vessel of greater length than the feathers, and three or four inches deep must be used. The well scoured, respectively bleached, and rinsed feathers are first dyed the color for the middle part, as usual on strings. After rinsing and drying they are taken off from the strings and "edged" singly. For this purpose prepare the dye-bath for the edging color, heat to the proper temperature, take the tip and quill respectively between the fore-finger and the thumb of both hands, dip the feathers edgewise, that is, with the ends of the fibres on one side of the stem, or the edge of the vane only, into the dye-bath as deep as the edging is to be wide, and move the feather in this position horizontally forward and backward in the bath until the shade is obtained. Then place the feather between several laps of clean dry muslin, squeeze it out by passing the hand over it, and dye the other edge in the same manner as the first. Finally rinse, starch and dry the feather as usual. In this connection a chemical reaction is worthy of mention, which was discovered about two years ago by an accident, and may be advantageously employed for the production of edgings upon ostrich feathers, if further developed by experiments. In a large feather-dyeing establishment, in Berlin, a sheet of paper which had been wetted with ammonia, and had become dry, had been left on a work-table, when one of the employees, who was handling a lot of feathers freshly dyed with methyl violet, inadvertently put one of the feathers, which was still moist, upon the impregnated paper. After a while, when the feather was picked up, it was found that the violet, all round the edge of the feather, had turned brilliant green, producing a very pleasing effect. It is rational to suppose that with mixed colors, in whose composition methyl violet largely enters, similar effects can be produced by the action of ammonia; and probably the same is the case with other aniline dyestuffs. GILDING AND SILVERING. Gilded and silvered ostrich feathers are but seldom in demand, and then only for grand evening dresses or stage effects, and for short seasons, which generally return far between. Their production is by no means a dyeing process, but rather an operation of surface ornamentation, still the dyer is sometimes requested to perform it. While goose feathers and other feathers of small value are wholly gilded or silvered, the gilding of ostrich feathers consists chiefly in a sprinkling with metallic dots, or sometimes in an edging, or is only applied to the tip of the feathers, which, from the nature of the operation, are treated singly. Such ornamented feathers, white as well as dyed, being only used for short periods, a permanent fixation of the gold or silver upon them is not required, but rather undesirable, as they will soon be redyed for other uses. For gilding, respectively silvering, a sufficiently adhesive solution of possibly colorless gum arabic is prepared and distributed by hand, and by means of a fine hair-brush, in smaller or larger dots, as required, over the upper side of the feather or along the edges, and before the gum solution becomes dry, sprinkled over with finely divided gold-leaf or silver-leaf. The feather is then turned over, given a few light taps with the hand to remove the loose dust of metal, and vigorously shaken, partly to prevent the fibres from sticking together, partly to remove the remaining loosely adhering particles of metal. The operation must be performed as rapidly as possible to prevent the gum solution from drying before the metallic dust is shaken off. The smaller the gum-dots are made, the quicker must the work be done, but the less is the danger of the fibres being pasted together, and the more elegant the appearance of the feather. The dots or spangles are made of different shapes, in little circles or squares, and sometimes arranged so as to form angular designs, according to taste and skill of the operator. Another very pretty, scarcely more permanent, but more frequently applied ornamentation of ostrich feathers, is the following. FROSTING. For this purpose the feathers are first dyed in a light or medium shade of any color, the effect of frosting feathers of a dark color being rather unfavorable. The feathers are then, after drying, covered on the upper side with a solution of clear gum arabic, as for gilding, but more closely, or may even be entirely brushed over with the gum solution, and are then, before the gum dries, sprinkled over with finely ground white glass, or mica, the latter giving the appearance of frosted silver. The glass powder or mica powder is then quickly and vigorously shaken off, to open the fibres and flues as much as possible, while drying. Finally, to complete the opening of the fibres, the feathers are steamed at the under side, and shaken in the air until open and dry. Great care is required in curling gilded or frosted feathers, that the metal or glass powder is not rubbed off in passing the fibres of the vane over the curling-knife. This operation being extremely difficult and dangerous, the use of a curling-iron, like that used by hair-dressers, is preferable to that of the knife. The iron is moderately heated, so as not to singe the feathers; then, beginning at the lower end of the feather, a part of the fibres on one side of the stem are taken by their ends between the shanks of the iron, the latter closed and the fibres wound downwards around it, the iron being carried on the under side of the feather towards the stem. Then first one side of the vane is successively curled from the quill up to the tip, when the same operation is repeated upon the other half of the feather. If, in this manner, the feather should be curled too strongly, the fibres are taken between the shanks of the warm curling-iron at the stem and simply drawn through the iron. Numerous ostrich feather dyers and dressers use the curling-iron altogether, instead of the knife; the only difficulty for the beginner is to get the proper heat, which, however, is soon learned. Very pretty effects are also obtained by dyeing the feathers a light shade of color, drying, gumming and sprinkling them with either powdered black glass or jet. RENOVATING FEATHERS. White ostrich feathers which, by long exposure to the show-window, or by lying in store for a protracted time, have lost their whiteness and turned yellow, and dyed feathers which, from the same causes, have become dirty, pale and discolored, can be restored to their former beauty by washing, respectively redyeing, as follows: I. A washing process, which is ordinarily only applied to white feathers which have become yellow, is as follows: Prepare a bath of two gallons of water at 145°F., to which add half a gallon of liquid ammonia (spirits of sal ammoniac, ammonia water); enter the feathers, work them once well through with the hands, and lay them down in the bath over night. On the following day take them up, wash them once through a soap-bath at 145°F., pass them again through the first ammoniacal bath, and rinse well and let them drain. Then prepare a bath of cold water, to which add so much of a clear solution of methyl violet 6 B., that a white china plate held about a foot below the surface of the water, appears with a faint bluish tint, or such a blue tone as is desired; and add to the bath so much sulphurous acid, that it gives the liquid a well defined odor. When the sulphurous acid mixes with the tinted liquid, the violet color of the latter disappears and changes to a greenish tint, which, however, turns again to blue upon the feathers when they are afterwards exposed to the action of the air. The feathers are then passed, singly, if possible, through the blue-bath, well drained, centrifugated or whizzed, starched and dried as usual. Colored feathers which have lost their freshness, and are to be redyed, are simply washed clean with soap and rinsed, or they are stripped of their color, as much as possible, with soap and oxalic acid, or bleached with peroxyd of hydrogen, as described in the beginning; whereupon they are dyed and treated like bleached new feathers, always taking into consideration, however, what of the old color may remain upon the feathers, may be utilizable as a bottom for the new color, or even as a component of it, for instance, in the case of many modes and several browns. II. Another method of renovating ostrich feathers presents the advantages that it is executed without the application of heat, that it is a simple cleaning process which attacks no color, and that it leaves the curling of the feathers intact, which is unavoidably taken out of them by washing with warm water and soap, or any other alkaline detergent substance. It is, therefore, only applied to feathers which have lost their purity of color by exposure, and whose curling is to be preserved, or is worthy of preserving. It is, in part, the same process which is known as "dry washing" among scourers and dyers of garments, and can be applied to feathers of any color and shade, white and even black, without exception. For this operation fill a basin or small wooden hand-tub with benzene, add a handful or two of potato flour (sifted potato starch), enter the feathers and rub them well through with the starch until clean; then squeeze then out by hand and press between muslin, finally whiz or shake them in the air until dry. This process is partly chemical, in so far as the benzene loosens the dust and other impurities which have settled upon the feathers, partly mechanical, as the numerous fine particles of the potato starch, which do not dissolve in benzene as soap does in water, rub these impurities off from the feather. By the combined action of the benzene and starch, and the friction applied, the feathers are not only cleaned, but the flues completely opened, so that the feather thus treated looks perfectly like new. A remarkable feature of this process is that the starch carries nearly all the impurities down with itself to the bottom of the wash-basin, and becomes soiled, while the benzene takes up every little of them, and can, therefore, after settling, be poured off from the starch sediment, and can be used several times before it needs to be purified or eventually becomes unfit for use. In using benzene, which is a highly combustible substance, the utmost precaution must be observed that no open flame or fire be in the work-room, neither open lamps nor a fire in the stove burning. Even doors leading to adjoining rooms, where lights or fires are burning, ought to be kept closed while working with benzene, because the benzene vapors, which may be carried to the flame by a draft of air, would inevitably ignite and cause an explosion and fire. Occurrences of this kind have been not unfrequently observed. Feathers which have been cleaned by this process, as well as new feathers, may be dyed by the following process. DYEING IN THE COLD WAY. This process is a real dyeing process, as well as a renovating process, both, however, to a limited extent, inasmuch as it can be applied only to white feathers or to such as are dyed with light and medium shades of certain colors which are to be freshened up; but it does not answer for dark colors. It is, however, extremely simple and easy to execute; besides, almost instantaneous, and therefore of great utility where rapid work is required, because it leaves the feathers perfectly in shape, like the benzene washing process, and does not affect the curling of the feather, if there is such. Old feathers which were already dyed cream, rose, salmon, light blue, light gray, light green, sea green, golden yellow, heliotrope or beige, can be redyed in the same colors, but must previously be washed with benzene; new white feathers do not require such washing. For this method of dyeing, aniline dyestuffs soluble in alcohol are used, viz.: for Cream, Curcumine or Aniline Orange, Rose, Eosine or Ponceau, Salmon, Curcumine and Eosine, Light Blue, Water Blue and Methylene Blue, Gray, Nigrosine, Sea-green, Malachite Green, Golden Yellow, Orange and Fast Brown, Heliotrope, Methyl violet 6 B., Beige, Methylene Blue, Curcumine and Fast Brown, mixed according to tone and shade. Operate as follows: Fill a white basin with a sufficient quantity of alcohol to completely wet the feathers in it; add, according to shade, a smaller or greater quantity of the clear alcoholic solution of the required dyestuff, or mixture of dyestuffs, pass the feathers singly, without previously wetting them, three or four times through the alcohol bath; then press them out between clean muslin, put a few handfuls of sifted potato starch upon a clean sheet of paper, and rub the feathers with it until thoroughly dry; finally, shake out the starch. RECAPITULATION OF GENERAL RULES. At all times have the feathers, which are to be dyed, scoured well, that is, washed clean from all externally adhering impurities, fat, etc.; naturally colored feathers bleached for all light and medium shades to be dyed upon them, and rinsed perfectly clean from the scouring or bleaching bath, first in two or three warm waters and then in cold water. On taking the feathers from any bath, always squeeze the liquid out first by drawing the feathers through the hand closed upon them, then by placing them straight between several laps of clean dry muslin and repeatedly passing the hand with quite a smart pressure over it. Never transfer the feathers, in any case, from one bath to another in a wet, but in a moist condition, or nearly dry. Never allow the feathers to become dry in the course of operations. If it is necessary to interrupt work, or to put feathers to one side for further treatment, dry them properly by first passing them through a bath of raw starch, in order to have the flues at all times as well opened as possible. In no case let the temperature of a bath, in which feathers are treated, rise to actual boiling, although for some dyestuffs a temperature near the boiling point is required to make them dye up, to become level or to fix them. In every instance, where an acid or acid salt is employed, either in a separate mordanting or fixing bath, or as a component of the dyebath, rinse well before drying. When sulphuric acid is used in the composition of a bath, add only so much of it as to give the water a very slight, scarcely perceptible acid taste. Although some artificial dyestuffs dye up without an addition of acid to the dye bath (basic dyestuffs), the addition of sulphuric acid, in a very small quantity, to the dye-bath is advantageous, rendering the colors brighter and also faster. When bisulphate of soda is employed, it is not necessary to also add sulphuric acid to the dye-bath; if it is added, however, it must only be in a very small quantity; careful rinsing in several warm and cold waters after dyeing is required. When alum alone is used without any other addition as mordant, sulphuric acid may be added, but only in the proportion of one tenth or, at the most, up to one fifth of the weight of alum, and careful rinsing in several warm and cold waters is the more indispensably required the more acid has been employed. All solutions of dyestuffs, as well as of chemicals, ought to be carefully filtered, and decoctions of woods, etc., strained before adding them to the bath; never add dyestuffs, drugs or chemicals in substance to any bath, in order to prevent solid particles from settling upon the feathers. Never add all the dyestuff probably required or prescribed by a recipe to the dye-bath at one time, but in several small quantities, each time after taking up the feathers, stir the bath after making the addition, re-enter the feathers and watch the progress of the dyeing carefully; when approaching the desired shade, add the dyestuff very cautiously, by drops if necessary, particularly with mixed colors, such as modes. Sample in proper time, and take not a whole feather for it, but pull off two or three fibres from the lower part of a feather, dry them quickly by squeezing between dry muslin, match, correct the bath and finish dyeing. While drying keep the feathers as much as possible in constant motion, shake and beat them. Do not interrupt operations, if it can be avoided, but do the work rapidly and continuously, without pausing. Keep every utensil scrupulously clean. THE END. CONTENTS. PAGE. Preface i Growth of the Ostrich Feather Trade, etc. 1 The Bird, Its Plumage and Habits 3 Sketch of Dyestuffs, etc. 5 Logwood 5 Turmeric 7 Bichromate of Potash 7 Archil 8 Safranine 10 Oxalic Acid 11 Indigo Blue 11 Sulphuric Acid 12 Copperas 13 Bismarck Brown 14 Concentrated Cotton Blue 14 Roceline 15 Recipes for Dyeing 16 Hints about the Dye-house 85 Miscellaneous Information 88 Washing Raw Stock 91 Shading 94 Paring, Steaming and Curling 95 Note of the Publisher 99 INDEX TO RECIPES. B. PAGE. BEIGE 62 BLACK 53 BLEACHING LIGHT COLORS WHITE 18 BLEACHING NATURAL GRAYS OR BLACKS WHITE 82 BLUE, ARMY 59 BLUE, ELECTRIC 65 BLUE, GENDARME 57 BLUE, LIGHT 21 BLUE, MEDIUM 67 BLUE, NAVY 31 BRONZE 74 BROWN, BISMARCK 28 BROWN, MEDIUM 66 BROWN, OLIVE 81 BROWN, SEAL 29 C. CARDINAL 33 CHOCOLATE 75 COFFEE 79 CORN 64 CREAM 25 D. DRAB, FELT 46 DRAB, PLAIN 78 E. ECRU 23 G. GARNET 40 GRAY, SILVER 26 GREEN, BOTTLE 43 GREEN, MEDIUM 61 GREEN, PEA 80 L. LAVENDER 38 LEMON 52 LILAC 56 M. MAGENTA 69 MAROON 51 MOSS 76 O. OLD-GOLD 39 OLIVE 36 ORANGE 48 P. PINK, LIGHT 20 PLUM 35 PURPLE 60 S. SALMON 71 SCARLET 50 SEA-FOAM 70 SLATE 47 STEEL 45 STONE 73 STRAWBERRY, CRUSHED 34 T. TERRA COTTA 42 TRILEUL 58 W. WHITE 16 INDEX TO SAMPLES. B. PAGE. BEIGE 34a BLACK 70a BLUE, ARMY 46a BLUE, ELECTRIC 70a BLUE, GENDARME 40a BLUE, LIGHT 26a BLUE, MEDIUM 24a BLUE, NAVY 64a BRONZE 64a BROWN, BISMARCK 76a BROWN, MEDIUM 82a BROWN, OLIVE 52a BROWN, SEAL 76a C. CARDINAL 82a CHOCOLATE 34a COFFEE 52a CORN 34a CREAM 26a D. DRAB, FELT 40a DRAB, PLAIN 58a E. ECRU 30a G. GARNET 40a GRAY, SILVER 30a GREEN, BOTTLE 52a GREEN, MEDIUM 82a GREEN, PEA 64a L. LAVENDER 26a LEMON 20a LILAC 20a M. MAGENTA 64a MAROON 46a MOSS 70a O. OLD-GOLD 82a OLIVE 58a ORANGE 76a P. PINK, LIGHT 20a PLUM 58a PURPLE 46a S. SALMON 26a SCARLET 70a SEA-FOAM 30a SLATE 40a STEEL 46a STONE 52a STRAWBERRY, CRUSHED 76a T. TERRA COTTA 58a TRILEUL 30a W. WHITE 20a CONTENTS OF APPENDIX. PAGE. General Remarks 103 Utensils 107 Preparation of Feathers 107 Cleaning, Bleaching, etc. 109 Drying or Starching 111 Bleaching or Decolorizing Natural Grays 112 Peroxyd of Hydrogen 114 Light Blue 115 Navy Blue 117 Gendarme Blue 119 Plum or Prune 119 Light Yellow 121 Medium Yellow 121 Dark Yellow 122 Golden Yellow 123 Old-Gold 124 Gray 125 Pearl Gray 126 Silver Gray 126 Brown 127 Light Brown 129 Rust Brown 130 Red Brown 130 Coffee Brown 131 Puce 132 Fawn 133 Chestnut Brown 133 Havanna 134 Mushroom 135 Light Drab 136 Beige 137 Modes 138 Reseda 140 Ordinary Green 141 Light Green 142 Moss Green 143 Bog Green 143 Grass Green 144 Rose 146 Red 147 Fast Alizarine Red 147 Scarlet 148 Ponceau 150 Bordeaux 151 Red Garnet 152 Brown Garnet 152 Ruby 153 Salmon 153 Amaranth 154 Bronze 155 Olive 156 Violet 158 Heliotrope and Lilac 159 Cream 160 White and Black 161 White 164 Black 166 Contrasts, Shadings, etc. 173 Edging or Borders 176 Gilding and Silvering 178 Frosting 180 Renovating Feathers 182 Dyeing in the Cold Way 186 Recapitulation of General Rules 187 SPECIALTIES FOR FEATHER AND SILK DYERS PH. H. KARCHER & CO., 55 CEDAR ST., NEW YORK, Sole Agent for GILLIARD, P. MONNET and CARTIER'S FRENCH ANILINE DYES IMPORTERS OF DYESTUFFS, EXTRACTS, CHEMICALS, &c. * * * * * ESTABLISHED 1861 HENRY A. GOULD & CO. IMPORTERS AND JOBBERS OF Indigo, Cutch, Dyewoods. GENERAL AGENTS Celebrated "Berlin Brand" Non-Poisonous Aniline Colors, including Substantive Dyes, and many varieties Soloble in Oils, &c. MANUFACTURED BY Actien Gesellschaft fur Anilin-Fabrikation, BERLIN, GERMANY. 17 & 19 Pearl Street, Boston. 78 William Street, New York. 71 North Front Street, Philadelphia. * * * * * A. KLIPSTEIN, 52 Cedar Street, NEW YORK. ANILINE COLORS, And all Dyestuffs and Chemicals used in Feather Dyeing. { 134 Milk St., Boston. BRANCH OFFICES: { 120 Arch St., Philadelphia. * * * * * WM. J. MATHESON & CO., 20 Cedar Street, New York. { 147 Milk St., Boston. BRANCH HOUSES: { 18 N. Front St., Philadelphia. { 22 S. Water Street, Providence, R. I. IMPORTERS OF AND DEALERS IN Coal Tar Colors and Dyestuffs MANUFACTURERS OF Dyewood, Sumac and Indigo Extracts, and Carmines. * * * * * American Ultramarine and Globe Anilin Works HELLER & MERZ, PROPRIETORS, 55 Maiden Lane, New York. P.O. Box 3508. Rose Bengal, Erythrosine, Fuchsine, Phloxine, Eosine, Violet, of Superior Quality. * * * * * John M. Sharpless & Co. MANUFACTURERS OF SOLID AND PASTE EXTRACTS OF DYEWOODS CUT AND BOLTED DYEWOODS IMPORTERS OF Cutch, Indigo, Chemicals, &c. Office: 20 & 22 N. Front St., Philadelphia, Pa. * * * * * R. HOLLIDAY'S SONS, 128 MILK ST., BOSTON. MASS. 45 N. FRONT ST., PHILADELPHIA. PRINCIPAL OFFICE: 7 PLATT ST., NEW YORK. MANUFACTURERS OF ALL ANILINE COLORS, ARCHIL, EXTRACT OF INDIGO, &c. PATENTED OF ACID MAGENTA. WORKS--Brooklyn, N. Y.; Huddersfield and Wakefield, England. * * * * * SCHOELLKOPF, HARTFORD & MACLAGAN, L't'd [Illustration] 3 Cedar St., 103 Milk St., NEW YORK. BOSTON. 42 N. Water St., PHILADELPHIA. SOLE AGENTS FOR SCHOELLKOPF ANILINE AND CHEMICAL CO. BUFFALO, N. Y. * * * * * TEXTILE COLORIST A Monthly Journal DEVOTED TO PRACTICAL DYEING, BLEACHING, PRINTING AND FINISHING, DYES, DYESTUFFS, AND CHEMICALS AS APPLIED TO DYEING, Textile Machinery, Carding, Spinning, Weaving, DESIGNING AND IMPROVED PROCESSES IN TEXTILE MANUFACTURING. ESTABLISHED, JANUARY, 1879. Published on the 15th of each month, at 506 ARCH STREET, PHILADELPHIA, U. S. A. Transcriber's Notes: Corrected obvious typos and inconsistencies in punctuation: p34a. BIEGE -> BEIGE (also in Index and Index to samples). p54. half a century age -> half a century ago. terra-cotta (Index) -> terra cotta (text). triluel -> trileul. p65. luke water -> luke-warm water. p104. certian -> certain. p122. turmeric is boiling -> turmeric in boiling. p124. analine -> aniline. p151. Lay down the feathers for four hours is a cold. bath -> Lay down the feathers for four hours in a cold bath. p162. most energetic and and effectious -> most energetic and effectious. p173. and hand them over -> and hands them over. p187. Operate of follows -> Operate as follows. p188. to put feathers one side -> to put feathers to one side. p189. composion -> composition In the Sample Index, the page for BLUE, MEDIUM should be 34a not 24a. Some inconsistencies and oddities in spelling and hyphenation have been left as printed: hand heat and hand-heat. centrifugated (in text) and soloble (in printed advertisement). redyed, re-dyed. peroxyd and peroxide. luke warm, lukewarm and luke-warm. p114. The correct formula for hydrogen peroxide is H_{2}O_{2} 
22784	----	ON LABORATORY ARTS BY RICHARD THRELFALL, M.A. PROFESSOR OF PHYSICS IN THE UNIVERSITY OF SYDNEY; MEMBER OF THE INSTITUTE OF ELECTRICAL ENGINEERS; ASSOCIATE-MEMBER OF THE INSTITUTE OF CIVIL ENGINEERS; MEMBER OF THE PHYSICAL SOCIETY London MACMILLAN AND CO, LIMITED NEW YORK: THE MACMILLAN COMPANY 1898 All rights reserved PREFACE 5 CHAPTER I 8 HINTS ON THE MANIPULATION OF GLASS AND ON GLASS-BLOWING FOR LABORATORY PURPOSES 8 § 4. Soft Soda Glass. § 6. Flint Glass. § 9. Hard or Bohemian, Glass. § 10. On the Choice of Sizes of Glass Tube. § 11. Testing Glass. § 13. Cleaning Glass Tubes. § 14. The Blow-pipe. § 18. The Table. § 19. Special Operations. § 20. Closing and blowing out the End of a Tube. § 21. To make a Weld. § 22. To weld two Tubes of different Sizes. § 24. To weld Tubes of very small Bore. § 30. To cut very thick Tubes. § 31. To blow a Bulb at the End of a Tube. § 32. To blow a bulb in the middle of a tube. § 33. To make a side Weld. § 34. Inserted Joints. § 35. Bending Tubes. § 36. Spiral Tubes. § 37. On Auxiliary Operations on Glass. § 38. Boring small Holes. § 39. For boring large holes through thick glass sheets. § 41. Operations depending on Grinding: Ground-in Joints. § 42. Use of the Lathe in Glass-working. § 46. Making Ground Glass. § 47. Glass-cutting. § 48. Cementing. § 49. Fusing Electrodes into Glass. § 51. The Art of making Air-light Joints. APPENDIX TO CHAPTER I. ON THE PREPARATION OF VACUUM TUBES FOR THE PRODUCTION OF PROFESSOR ROENTGEN'S RADIATION. CHAPTER II. GLASS-GRINDING AND OPTICIANS' WORK. § 61. Details of the Process of Fine Grinding. § 62. Polishing. § 63. Centering. § 65. Preparing Small Mirrors for Galvanometers. § 66. Preparation of Large Mirrors or Lenses for Telescopes. § 69. The Preparation of Flat Surfaces of Rock Salt. § 70. Casting Specula for Mirrors. § 71. Grinding and polishing Specula. § 72. Preparation of Flat Surfaces. § 73. Polishing Flat Surfaces on Glass or on Speculum Metal. CHAPTER III. MISCELLANEOUS PROCESSES. § 74. Coating Glass with Aluminium and Soldering Aluminium. § 75. The Use of the Diamond-cutting Wheel. § 76. Arming a Wheel. § 77. Cutting a Section. § 78. Grinding Rock Sections, or Thin Slips of any Hard Material. § 79. Cutting Sections of Soft Substances. § 80. On the Production of Quartz Threads. § 84. Drawing Quartz Threads. § 86. Drawing Threads by the Catapult. § 87. Drawing Threads by the Flame alone. § 88. Properties of Threads. § 90. On the Attachment of Quartz Fibres. § 91. Other Modes of soldering Quartz. § 92. Soldering. § 94. Preparing a Soldering Bit. § 95. Soft Soldering. § 97. Soldering Zinc. § 98. Soldering other Metals. § 99. Brazing. § 100. Silver Soldering. § 101. On the Construction of Electrical Apparatus--Insulators. § 102. Sulphur. § 103. Fused Quartz. § 104. Glass. § 105. Ebonite or Hard Rubber. § 106. Mica. § 107. Use of Mica in Condensers. § 108. Micanite. § 109. Celluloid. § 110. Paper. § 111. Paraffined Paper. § 112. Paraffin. § 113. Vaseline, Vaseline Oil, and Kerosene Oil. § 114. Imperfect Conductors. § 116. Conductors. § 117. Platinoid. § 119. Platinum Silver. § 120. Platinum Iridium. § 121. Manganin. § 122. Other Alloys. § 123. Nickelin. § 124. Patent Nickel. § 125. Constantin. 126. Nickel Manganese Copper. CHAPTER IV. ELECTROPLATING AND ALLIED ARTS. § 127. Electroplating. § 128. The Dipping Bath. § 130. Scratch-brushing. § 131. Burnishing. § 132. Silver-plating. § 133. Cold Silvering. § 134. Gilding. § 135. Preparing Surfaces for Gilding. § 136. Gilding Solutions. § 137. Plating with Copper. § 138. Coppering Aluminium. § 140. Alkaline Coppering Solution. § 141. Nickel-plating. 142. Miscellaneous Notes on Electroplating. § 143. Blacking Brass Surfaces. § 144. Sieves. § 145. Pottery making in the Laboratory. APPENDIX. PLATINISING GLASS. PREFACE EXPERIMENTAL work in physical science rests ultimately upon the mechanical arts. It is true that in a well-appointed laboratory, where apparatus is collected together in greater or less profusion, the appeal is often very indirect, and to a student carrying out a set experiment with apparatus provided to his hand, the temptation to ignore the mechanical basis of his work is often irresistible. It often happens that young physicists are to be found whose mathematical attainments are adequate, whose observational powers are perfectly trained, and whose general capacity is unquestioned, but who are quite unable to design or construct the simplest apparatus with due regard to the facility with which it ought to be constructed. That ultimate knowledge of materials and of processes which by long experience becomes intuitive in the mind of a great inventor of course cannot be acquired from books or from any set course of instruction. There are, however, many steps between absolute ignorance and consummate knowledge of the mechanical arts, and it is the object of the following pages to assist the young physicist in making his first steps towards acquiring a working knowledge of "laboratory arts." However humble the ambition may be, no one can be more keenly alive than the writer to the inadequacy of his attempt; and it is only from a profound sense of the necessity which exists for some beginning to be made, that he has had the courage to air his views on matters about which there are probably hundreds or thousands of people whose knowledge is superior to his own. Moreover, nothing has been further from the writer's mind than any idea of "instructing" any one; his desire is--if happily it may so befall--to be of assistance, especially to young physicists or inventors who wish to attain definite mechanical ends with the minimum expenditure of time. Most people will agree that one condition essential to success in such an undertaking is brevity, and it is for this reason that alternative methods as a rule have not been given, which, of course, deprives the book of any pretence to being a "treatise." The writer, therefore, is responsible for exercising a certain amount of discretion in the selection he has made, and it is hardly to be hoped that he has in all--or even in the majority of cases--succeeded in recommending absolutely the best method of procedure. This brings another point into view. Before all things the means indicated must be definite and reliable. It is for this reason that the writer has practically confined himself to matters lying within his own immediate experience, and has never recommended any process (with one or two minor exceptions, which he has noted) which he has not actually and personally carried through to a successful issue. This, although it is a matter which he considers of the highest importance, and which is his only title to a hearing, has unfortunately led to a very personal tone in the book. With regard to the arts treated of in the following pages, matters about which information is easily acquired--such as carpentering, blacksmithing, turning, and the arts of the watchmaker--have been left on one side. With regard to the last, which is of immense use in the laboratory, there happen to be at least two excellent and handy books, viz. Saunier's Watchmakers' Handbook, Tripplin, London, 1892; and Britton's Watchmakers' Dictionary and Guide. With regard to carpentering, turning, and blacksmithing, almost any one who so desires can obtain a little practical experience in any village. A short chapter has been devoted to glass-blowing, in spite of there being an excellent and handy book by Mr. Shenstone (The Methods of Glass-blowing, Rivington) on the subject already in existence. The reason for this exception lies in the fact that the writer's methods differ considerably from those advocated by Mr. Shenstone. The chapter on opticians' work has had to be compressed to an extent which is undesirable in dealing with so complex and delicate an art, but it is hoped that it will prove a sufficient introduction for laboratory purposes. In this matter the writer is under great obligations to his friend and assistant, Mr. James Cook, F.R.A.S, who gave him his first lessons in lens-making some twenty years ago. To Mr. John A. Brashear of Allegheny, Pa, thanks are due for much miscellaneous information on optical work, which is included verbatim in the text, some of it contained originally in printed papers, and some most kindly communicated to the writer for the purpose of this book. In particular, the writer would thank Mr. Brashear for his generously accorded information as to the production of those "flat" surfaces for which he is so justly famous. The writer is also indebted to Mr. A. E. Kennelly for some information as to American practice in the use of insulating material for electrical work, and to his friends Mr. J. A. Pollock and Dr. C. J. Martin for many valuable suggestions. For the illustrations thanks are due to Mrs. Threlfall and Mr. James Cook. With regard to matters which have come to the writer's knowledge by his being specifically instructed in them from time to time, due acknowledgment is, it is hoped, made in the text. With regard to the question as to what matters might be included and what omitted, the general rule has been to include information which the author has obtained with difficulty, and to leave on one side that which he has more easily attained. All the "unities" have been consistently outraged by a deliberate use of the English and metric systems side by side. So long as all the materials for mechanical processes have to be purchased to specifications in inches and feet, it is impossible to use the centimetre consistently without introducing inconvenience. However, everybody ought to, and probably does, use either system with equal facility. No attempt has been made at showing how work can be done without tools. Though, no doubt, a great deal can be done with inferior appliances where great economy of money and none of time is an object, the writer has long felt very strongly that English physical laboratory practice has gone too far in the direction of starving the workshop, and he does not wish, even indirectly, 'to give any countenance to such a mistaken policy. Physical research is too difficult in itself, and students' time is too valuable, for it to be remunerative to work with insufficient appliances. In conclusion, the writer would ask his readers to regard the book to some extent as tentative, and as a means to the procuring and organising of information bearing upon laboratory arts. Any information which can be given will be always thankfully received, and the author hereby requests any reader who may happen to learn something of value from the book to communicate any special information he may possess, so that it may be of use to others should another edition ever be called for. CHAPTER I HINTS ON THE MANIPULATION OF GLASS AND ON GLASS-BLOWING FOR LABORATORY PURPOSES § 1. THE art of glass-blowing has the conspicuous advantage, from the point of view of literary presentation, of being to a great extent incommunicable. As in the case of other delightful arts--such as those treated of in the Badminton Library, for instance--the most that can be done by writing is to indicate suitable methods and to point out precautions which experience has shown to be necessary, and which are not always obvious when the art is first approached. It is not the object of this work to deal with the art of glass-blowing or any other art after the manner befitting a complete treatise, in which every form of practice is rightly included. On the contrary, it is my wish to avoid the presentation of alternative methods. I consider that the presentation of alternative methods would, for my present purpose, be a positive disadvantage, for it would swell this book to an outrageous size; and to beginners--I speak from experience--too lavish a treatment acts rather by way of obscuring the points to be aimed at than as a means of enlightenment. The student often does not know which particular bit of advice to follow, and obtains the erroneous idea that great art has to be brought to bear to enable him to accomplish what is, after all, most likely a perfectly simple and straightforward operation. This being understood, it might perhaps be expected that I should describe nothing but the very best methods for obtaining any proposed result. Such, of course, has been my aim, but it is not likely that I have succeeded in every case, or even in the majority of cases, for I have confined myself to giving such directions as I know from my own personal experience will, if properly carried out, lead to the result claimed. In the few cases in which I have to refer to methods of which I have no personal experience, I have endeavoured to give references (usually taking the form of an acknowledgment), so that an idea of their value may be formed. All methods not particularised may be assumed by the reader to have come within my personal experience. § 2. Returning to glass-blowing, we may note that two forms of glass-blowing are known in the arts, "Pot" blowing and "Table" blowing. In the former case large quantities of fluid "metal" (technical term for melted glass) are assumed to be available, and as this is seldom the case in the laboratory, and as I have not yet felt the want of such a supply, I shall deal only with "table" blowing. Fortunately there is a convenient book on this subject, by Dr. Shenstone (Rivingtons), so that what I have to say will be as brief as possible, consistent with sufficiency for everyday work. As a matter of fact there is not very much to say, for if ever there was an art in which manual dexterity is of the first and last importance, that art is glass-working. I do not think that a man can become an accomplished glass-blower from book instructions merely--at all events, not without much unnecessary labour,--but he can learn to do a number of simple things which will make an enormous difference to him both as regards the progress of his work and the state of his pocket. § 3. The first thing is to select the glass. In general, it will suffice to purchase tubes and rods; in the case where large pieces (such as the bulbs of Geissler pumps) have to be specially prepared by pot-blowing, the student will have to observe precautions to be mentioned later on. There are three kinds of glass most generally employed in laboratories. § 4. Soft Soda Glass, obtained for the most part from factories in Thuringia, and generally used in assembling chemical apparatus.--This glass is cheap, and easily obtainable from any large firm of apparatus dealers or chemists. It should on no account be purchased from small druggists, for the following reasons:- (a) It is usually absurdly dear when obtained in this way. (b) It is generally made up of selections of different age and different composition, and pieces of different composition, even if the difference is slight, will not fuse together and remain together unless joined in a special manner. (c) It is generally old, and this kind of glass often devitrifies with age, and is then useless for blowpipe work, though it may be bent sufficiently for assembling chemical apparatus. Devitrified glass looks frosty, or, in the earlier stages, appears to be covered by cobwebs, and is easily picked out and rejected. § 5. It might be imagined that the devitrification would disappear when the glass is heated to the fusing point; and so it does to a great extent, but for many operations one only requires to soften the glass, and the devitrification often persists up to this temperature. My experience is that denitrified glass is also more likely to crack in the flame than good new glass, though the difference in this respect is not very strongly marked with narrow tubes. § 6. Flint Glass. Magnificent flint glass is made both in England and France. The English experimenter will probably prefer to use English glass, and, if he is wise, will buy a good deal at a time, since it does not appear to devitrify with age, and uniformity is thereby more likely to be secured. I have obtained uniformly good results with glass made by Messrs. Powell of Whitefriars, but I daresay equally good glass may be obtained elsewhere. For general purposes flint glass is vastly superior to the soft soda mentioned above. In the first place, it is very much stronger, and also less liable to crack when heated--not alone when it is new, but also, and especially, after it has been partly worked. Apparatus made of flint glass is less liable to crack and break at places of unequal thickness than if made of soda glass. This is not of much importance where small pieces of apparatus only are concerned, because these can generally be fairly annealed; and if the work is well done, the thickness will not be uneven. It is a different matter where large pieces of apparatus, such as connections to Geissler pumps, are concerned, for the glass has often to be worked partly in situ, and can only be imperfectly annealed. Joints made between specimens of different composition are much more likely to stand than when fashioned in soda glass. Indeed, if it is necessary to join two bits of soda glass of different kinds, it is better to separate them by a short length of flint glass; they are more likely to remain joined to it than to each other. A particular variety of flint glass, known as white enamel, is particularly suitable for this purpose, and, indeed, may be used practically as a cement. § 7, It is, however, when the necessity of altering or repairing apparatus complicated by joints arises that the advantage of flint glass is most apparent. A crack anywhere near to a side, or inserted joint, can scarcely ever be repaired in the case of soda glass apparatus, even when the glass is quite thin and the dimensions small. It should also be mentioned that flint glass has a much more brilliant appearance than soda glass. Of course, there is a considerable difference between different kinds of flint glass as to the melting point, and this may account for the divergency of the statements usually met with as to its fusibility compared with that of soda glass. The kind of flint glass made by Messrs. Powell becomes distinctly soft soon after it is hot enough to be appreciably luminous in a darkened room, and at a white heat is very fluid. This fluidity, though of advantage to the practised worker, is likely to give a beginner some trouble. § 8. As against the advantages enumerated, there are some drawbacks. The one which will first strike the student is the tendency of the glass to become reduced in the flame of the blow-pipe. This can be got over by proper adjustment of the flame, as will be explained later on. A more serious drawback in exact work is the following. In making a joint with lead glass it is quite possible to neglect to fuse the glass completely together at every point; in fact, the joint will stand perfectly well even if it be left with a hole at one side, a thing which is quite impossible with soft soda glass, or is at least exceedingly unusual. An accident of this kind is particularly likely to happen if the glass be at all reduced. Hence, if a joint does not crack when cold, the presumption is, in the case of soda glass, that the joint is perfectly made, and will not allow of any leak; but this is not the case with flint glass, for which reason all joints between flint glass tubes require the most minute examination before they are passed. If there are any air bubbles in the glass, especial care must be exercised. § 9. Hard or Bohemian, Glass. This is, of course, used where high temperatures are to be employed, and also in certain cases where its comparative insolubility in water is of importance. It is very unusual for the investigator to have to make complicated apparatus from this glass. Fused joints may be made between hard glass and flint glass without using enamel, and though they often break in the course of time, still there is no reason against their employment, provided the work be done properly, and they are not required to last too long. § 10. On the Choice of Sizes of Glass Tube. It will be found that for general purposes tubes about one-quarter inch in inside diameter, and from one-twentieth to one-fortieth of an inch thick, are most in demand. Some very thin soda glass of these dimensions (so-called "cylinder" tubes) will be found very handy for many purposes. For physico-chemical work a good supply of tubing, from one-half to three-quarters of an inch inside diameter, and from one-twentieth to one-eighth inch thick, is very necessary. A few tubes up to three inches diameter, and of various thicknesses, will also be required for special purposes. Thermometer and "barometer" tubing is occasionally required, the latter, by the way, making particularly bad barometers. The thermometer tubing should be of all sizes of bore, from the finest obtainable up to that which has a bore of about one-sixteenth of an inch. Glass rods varying from about one-twentieth of an inch in diameter up to, say, half an inch will be required, also two or three sticks of white enamel glass for making joints. To facilitate choice, there is appended a diagram of sizes from the catalogue of a reliable German firm, Messrs. Desaga of Heidelberg, and the experimenter will be able to see at a glance what sizes of glass to order. It is a good plan to stock the largest and smallest size of each material as well as the most useful working sizes. Fig. 1. § 11. Testing Glass. "Reject glass which has lumps or knots, is obviously conical, or has long drawn-out bubbles running through the substance." If a scratch be made on the surface of a glass tube, and one end of the scratch be touched by a very fine point of fused glass, say not more than one-sixteenth inch in diameter, the tube, however large it is (within reason), ought to crack in the direction of the scratch. If a big crack forms and does not run straight, but tends to turn longitudinally, it is a sign that the glass is ill annealed, and nothing can be done with it. If such glass be hit upon in the course of blow-pipe work, it is inadvisable to waste time upon it; the best plan is to reject it at once, and save it for some experiment where it will not have to be heated. The shortest way of selecting glass is to go to a good firm, and let it be understood that if the glass proves to be badly annealed it will be returned. Though it was stated above that the glass should not be distinctly conical, of course allowance must be made for the length of the pieces, and, on the other hand, a few highly conical tubes will be of immense service in special cases, and a small supply of such should be included. The glass, as it is obtained, should be placed in a rack, and covered by a cloth to reduce the quantity of dust finding its way into the tubes. It has been stated by Professor Ostwald that tubes when reared up on end tend to bend permanently. I have not noticed this with lead glass well supported. Each different supply should be kept by itself and carefully described on a label pasted on to the rack, and tubes from different lots should not be used for critical welds. This remark is more important in the case of soda than of lead glass. In the case of very fine thermometer tubes it will be advisable to cover the ends with a little melted shellac, or, in special cases, to obtain the tubes sealed from the works. Soda glass can generally be got in rather longer lengths than lead glass; the longer the lengths are the better, for the waste is less. It is useful to be able to distinguish the different kinds of glass by the colour. This is best observed by looking towards a bright surface along the whole length of the tube and through the glass. Lead glass is yellow, soda glass is green, and hard glass purple in the samples in my laboratory, and I expect this is practically true of most samples. [Footnote: Some new lead glass I have is also almost purple in hue. If any doubt exists as to the kind of glass, it may be tested at once in the blow-pipe flame, or by a mixture of oils of different refractive indices, as will be explained later.] § 12. The question of the solubility of glass in reagents is one of great importance in accurate work, though it does not always meet with the attention it deserves. It is impossible here to go into the matter with sufficient detail, and the reader is therefore referred to the Abstracts of the Chemical Society, particularly for the years 1889 and 1892. The memoir by F. Kohlrausch, Wied. Ann. xliv, should be consulted in the original. The following points may be noted. A method of testing the quality of glass is given by Mylius (C. S. J. Abstracts, 1889, p. 549), and it is stated that the resistance of glass to the action of water can generally be much increased by leaving it in contact with cold water for several days, and then heating it to 300° to 400° C. This improvement seems to be due to the formation of a layer of moist silica on the surface, and its subsequent condensation into a resisting layer by the heating. Mylius (C. S. J. Abstracts, 1892, p. 411), and Weber, and Sauer (C. S. J. Abstracts, 1892, p. 410) have also shown that the best glass for general chemical purposes consists of: Silica, 7 to 8 parts Lime, 1 part Alkali, 1.5 to 1.1 parts. This is practically "Bohemian" tube glass. The exact results are given in the Berichte of the German Chemical Society, vol. xxv. An excellent account of the properties of glass will be found in Grove's edition of Miller's Elements of Chemistry. § 13. Cleaning Glass Tubes. This is one of the most important arts in chemistry. If the tubes are new, they are generally only soiled by dust, and can be cleaned fairly easily--first by pushing a bit of cotton waste through with a cane, or pulling a rag through with string--and then washing with sand and commercial hydrochloric acid. I have heard of glass becoming scratched by this process, and breaking in consequence when heated, but have never myself experienced this inconvenience. In German laboratories little bits of bibulous paper are sometimes used instead of sand; they soon break into a pulp, and this pulp has a slightly scouring action. As soon as the visible impurities are removed and the tube when washed looks bright and clean, it may be wiped on the outside and held perpendicularly so as to allow the water film to drain down. If the tube be greasy (and perhaps in other cases) it will be observed that as the film gets thinner the water begins to break away and leave dry spots. For accurate work this grease, or whatever it is, must be removed; and after trying many plans for many years, I have come back to the method I first employed, viz. boiling out with aqua regia. For this purpose, close one end of the tube by a cork (better than a rubber bung, because cheaper), and half fill the tube with aqua regia; then, having noted the greasy places, proceed to boil the liquid in contact with the glass at these points, and in the case of very obstinate dirt--such as lingers round a fused joint which has been made between undusted tubes--leave the whole affair for twelve hours. If the greasiness is only slight, then simply shaking with hot aqua regia will often remove it, and the aqua regia is conveniently heated in this case by the addition of a little strong sulphuric acid. The spent aqua regia may be put into a bottle. It is generally quite good enough for the purpose of washing glass vessels with sand, as above explained. However carefully a tube is cleaned before being subjected to blowpipe operations, it will be fouled wherever there is an opening during the process of heating, unless the extreme tip only of an oxidising flame be employed. Even this should not be trusted too implicitly unless an oxygas or hydrogen flame is employed. When a tube or piece of apparatus has been cleaned by acid, so that on clamping it vertically, dry spaces do not appear, it may be rinsed with platinum distilled water and left to drain, the dust being, of course, kept out by placing a bit of paper round the top. For accurate work water thus prepared is to be preferred to anything else. When the glass is very clean interference colours will be noticed as the water dries away. Carefully-purified alcohol may in some cases be employed where it is desired to dry the tube or apparatus quickly. In this case an alcohol wash bottle should be used, and a little alcohol squirted into the top of the tube all round the circumference. The water film drags the alcohol after it, and by waiting a few minutes and then adding a few more drops of alcohol, the water may be practically entirely removed, especially if a bit of filter paper be held against the lower end of the tube. It is customary in some laboratories to use ether for a final rinse, but unless the ether is freshly distilled and very pure, it leaves a distinct organic residue. When no more liquid can be caused to drain away, the tube may be dried by heating it along its length, beginning at the top (to get the advantage of the reduction of surface tension), and so on all down. It will then be possible to mop up a little more of the rinsing liquid. When the tube is nearly dry a loose plug of cotton wool may be inserted at the bottom. The wool must be put in so that the fibres lie on an even surface inside the tube, and the wool must be blown free from dust. Ordinary cotton wool is useless, from being dusty and the fibres short, and the same remark applies to wadding. Use nothing but what is known as "medicated" cotton wool with a good long fibre. The tube will usually soon dry of itself when the cover is lifted an inch or so. If water has been used, the air-current may be assisted by means of the water-pump, the air being sucked from the top, so that the wool has an opportunity of acting as a dust filter; a very slow stream of air only must be employed. For connecting the tube to the pump, a bit of India-rubber tube about an inch in diameter, with a bore of about one-eighth of an inch, may be employed. The end of the rubber tube is merely pressed against the edge of the glass. These remarks apply, with suitable modification, to all kinds of finished apparatus having two openings. For flasks and so on, it is convenient to employ a blowing apparatus, dust being avoided by inserting a permanent plug of cotton wool in one of the leading tubes. The efficiency of this method is greatly increased by using about one foot of thin copper tube, bent into a helix, and heated by means of a Bunsen burner; the hot air (previously filtered) is passed directly into the flask, bottle, or whatever the apparatus may be. This has proved so convenient that a copper coil is now permanently fastened to the wall in one of the rooms of my laboratory. The above instructions indicate greater refinement than is in general necessary or proper for tubes that have to be afterwards worked by the blow-pipe. In the majority of cases all that is necessary is to remove the dust, and this is preferably done by a wad of cotton waste (which does not leave shreds like cotton wool), followed by a bit of bibulous filter paper. I would especially warn a beginner against neglecting this precaution, for in the process of blowing, the dust undergoes some change at the heated parts of the apparatus, and forms a particularly obstinate kind of dirt. In special cases the methods I have advocated for removing dirt and drying without covering the damp surfaces with dust are inadequate, but an experimenter who has got to that stage will have nothing to learn from such a work as this. § 14. The Blow-pipe. I suppose a small book might easily be written on this subject but what I have to say--in accordance with the limitation imposed--will be brief. For working lead glass I never use anything but an oxygas blow-pipe, except for very large work, and should never dream of using anything else. Of course, to a student who requires practice in order to attain dexterity this plan would be a good deal too dear. My advice to such a one is--procure good soda glass, and work it by means of a modification of a gas blow-pipe, to be described directly. The Fletcher's blow-pipes on long stems are generally very inconvenient. The flame should not be more than 5 or 6 inches from the working table at most, especially for a beginner, who needs to rest his arms on the edge of the table to secure steadiness. The kind of oxygas blow-pipe I find most convenient is indicated in the sketch. (Fig. 2) I like to have two nozzles, which will slip on and off, one with a jet of about 0.035 inch in diameter, the other of about double this dimension. The oxygen is led into the main tube of the blow-pipe by another tube of much smaller diameter, concentric with the main tube (Fig. 3, at A). The oxygen is mixed with the gas during its escape from the inner tube, which is pierced by a number of fine holes for the purpose, the extreme end being closed up. The inner tube may run up to within half an inch of the point where the cap carrying the nozzle joins the larger tube. Fig. 2. Fig. 3. If it is desired to use the blow-pipe for working glass which is already fixed in position to a support, it will be found very advantageous to use a hooked nozzle. The nozzle shown in the sketch is not hooked enough for this work, which requires that the flame be directed 'backwards towards the worker. With a little practice such a flame may be used perfectly well for blowing operations on the table, as well as for getting at the back of fixed tubes. To warm up the glass, the gas supply is turned full on, and enough oxygen is allowed to pass in to clear the flame. The work is held in front of, but not touching, the flame, until it is sufficiently hot to bear moving into the flame itself. The, work is exposed to this flame until, in the case of lead glass, traces of reduction begin to appear. When this point is reached the oxygen tap is thrown wide open. I generally regulate the pressure on the bags, so that under these circumstances the flame is rather overfed with oxygen. This condition is easily recognised, as follows. The flame shrinks down to a very small compass, and the inner blue cone almost disappears; also flashes of yellow light begin to show themselves--a thing which does not occur when the proportions of the gases are adjusted for maximum heating effect. For many purposes the small dimensions of the flame render it very convenient, and the high temperature which can be attained at exact spots enables glass to be fused together after a certain amount of mixing, which is an enormous advantage in fusing lead glass on to hard glass. The lead glass should not be heated hot enough to burn, but, short of this, the more fluid it is the better for joints between dissimilar samples. It will be noticed that the blow-pipe can be rotated about a vertical axis so as to throw the flame in various directions. This is often indispensable. § 15. In general the oxygen flame does not require to be delivered under so high a pressure as for the production of a lime light. In England, I presume, most experimenters will obtain their oxygen ready prepared in bottles, and will not have to undergo the annoyance of filling a bag. If, however, a bag is used, and it has some advantages (the valves of bottles being generally stiff), I find that a pressure produced by placing about two hundredweight (conveniently divided into four fifty-six pound weights) on bags measuring 3' x 2'6" x 2' (at the thicker end) does very well. To fill such a bag with oxygen, about 700 grms of potassium chlorate is required. If the experimenter desires to keep his bag in good order, he must purify his oxygen by washing it with a solution of caustic soda, and then passing it through a "tower" of potash or soda in sticks, and, finally, through a calcium chloride tower. This purifying apparatus should be permanently set up on a board, so that it may be carried about by the attendant to wherever it is required. Oxygen thus purified does not seem to injure a good bag--at least during the first six or seven years: In order to reduce the annoyance of preparing oxygen, the use of the usual thin copper conical bottle should be avoided. The makers of steel gas bottles provide retorts of wrought iron or steel for oxygen-making, and these do very well. They have the incidental advantage of being strong enough to resist the attacks of a servant when a spent charge is being removed. The form of retort referred to is merely a large tube, closed at one end, and with a screw coupling at the other; the dimensions may be conveniently about 5 inches by 10. The screw threads should be filled with fireclay (as recommended by Faraday) before the joint is screwed up. Before purchasing a bottle the experimenter will do well to remember that unless it is of sufficiently small diameter to go into his largest vice, he will be inconvenienced in screwing the top on and off. Why these affairs are not made with union joints, as they should be, is a question which will perhaps be answered when we learn why cork borers are still generally made of brass, though steel tube has long been available. Fig. 4. These little matters may appear very trivial--and so they are--but the purchaser of apparatus will generally find that unless he looks after details himself, they will not be attended to for him. Whether a union joint is provided or not, let it be seen that the end of the delivery tube is either small enough to fit a large rubber tube connection going to the wash-bottle, or large enough to allow of a cork carrying a bit of glass tube for the same purpose to be inserted. This tube should not be less than half an inch in inside diameter. Never use a new bottle before it has been heated sufficiently to get rid of grease and carbonaceous dirt. A convenient oxygen-making apparatus is shown in Fig. 4, which is drawn from "life." § 16. For large blow-pipe work with lead glass I recommend a system of four simple blow-pipes, in accordance with the sketch annexed. I first saw this system in operation in the lamp factory of the Westinghouse Electric Company at Pittsburg in 1889, and since then I have seen it used by an exceedingly clever "trick" glass-worker at a show. After trying both this arrangement and the "brush flame" recommended by Mr. Shenstone, I consider the former the more convenient; however, I daresay that either can be made to work in competent hands, but I shall here describe only my own choice. [Footnote: A brush flame is one which issues from the blow-pipe nozzle shaped like a brush, i.e. it expands on leaving the jet. It is produced by using a cylindrical air jet or a conical jet with a large aperture, say one-eighth of an inch. See Fig. 25.] As will be seen, the blow-pipe really consists of four simple brass tube blow-pipes about three-eighths of an inch internal diameter and 3 inches long, each with its gas and air tap and appropriate nozzle. Each blowpipe can turn about its support (the gas-entry pipe) to some extent, and this possibility of adjustment is of importance, The air jets are merely bits of very even three-sixteenths inch glass tubing, drawn down to conical points, the jets themselves being about 0.035 inch diameter. Fig. 5. The flames produced are the long narrow blow-pipe flames used in blow-pipe analysis, and arranged so as to consist mostly of oxidising flame. The air-supply does not require to be large, nor the pressure high--5 to 10 inches of water will do--but it must be very regular. The "trick" glass-blower I referred to employed a foot bellows in connection with a small weighted gasometer, the Westinghouse Company used their ordinary air-blast, and I have generally used a large gas-holder with which I am provided, which is supplied by a Roots blower worked by an engine. I have also used a "velocity pump" blower, which may be purchased amongst others from Gerhardt of Bonn. The arrangement acts both as a sucking and blowing apparatus, and is furnished with two manometers and proper taps, etc. As I have reason to know that arrangements of this kind work very ill unless really well made, I venture to add that the Gerhardt arrangement to which I refer is No. 239 in his catalogue, and costs about three pounds. It hardly gives enough air, however, to work four blow-pipes, and the blast requires to be steadied by passing the air through a vessel covered with a rubber sheet. In default of any of these means being available, one of Fletcher's foot-blowers may be employed, but it must be worked very regularly. A table mounted with one blow-pipe made on this plan, and worked by a double-acting bellows, is recommended for students' use. For working flint glass, the air jet may be one-eighth of an inch in diameter and the pressure higher--this will give a brush flame. See Fig. 25. It will be seen, on looking at the sketch of the blowpipe system, that the pair of blow-pipes farther from the observer can be caused to approach or recede at will by means of a handle working a block on a slide. It often happens that after using all four blow-pipes at once it is necessary to have recourse to one blow-pipe only, and to do this conveniently and quickly is rather an object. Now, in my arrangement I have to turn off both the gas and air from the farther system, and then put in a bit of asbestos board to prevent the nozzles being damaged by the flame or flames kept alight. As I said before, when some experience is gained, glassblowing, becomes a very simple art, and work can be done under circumstances so disadvantageous that they would entirely frustrate the efforts of a beginner. This is not any excuse, however, for recommending inferior arrangements. Consequently, I say that the pipes leading in gas and air should be all branches of one gas and one air pipe, in so far as the two remote and one proximate blow-pipe are concerned, and these pipes should come up to the table to the right hand of the operator, and should have main taps at that point, each with a handle at least 2 inches long. By this arrangement the operator can instantly turn down all the blow-pipes but one, while, if the inverse operation is required, all the three pipes can be started at once. [Footnote: I find, since writing the above, that I have been anticipated in this recommendation by Mr. G. S. Ram, The Incandescent Lamp and its Manufacture, p. 114.] The separate air and gas taps must be left for permanent regulation, and must not be used to turn the supply on or cut it off. In some respects this blow-pipe will be found more easy to manage than an oxygas blow-pipe, for the glass is not so readily brought to the very fluid state, and this will often enable a beginner who proceeds cautiously to do more than he could with the more powerful instrument. Though I have mentioned glass nozzles for the air supply, there is no difficulty in making nozzles of brass. For this purpose let the end of a brass tube of about one-eighth of an inch diameter be closed by a bit of brass wire previously turned to a section as shown (Fig. 6), and then bored by a drill of the required diameter, say -.035 inch. It is most convenient to use too small a drill, and to gradually open the hole by means of that beautiful tool, the watchmaker's "broach." The edges of the jet should be freed from burr by means of a watchmaker's chamfering tool (see Saunier's Watchmaker's Hand-book, Tripplin, 1882, p. 232, § 342), or by the alternate use of a slip of Kansas stone and the broach. Fig. 6. The construction of this blow-pipe is so simple, that in case any one wishes to use a brush flame, he can easily produce one simply by changing his air jets to bits of the same size (say one-eighth to one-sixteenth of an inch) tubing, cut off clean. To insure success, the ends of the tubes must be absolutely plane and regular; the slightest inequality makes all the difference in the action of the instrument. If a jet is found to be defective, cut it down a little and try again; a clean-cut end is better than one which has been ground flat on a stone. The end of a tube may, however, be turned in a manner hereafter to be described so as to make an efficient jet. Several trials by cutting will probably have to be made before success is attained. For this kind of jet the air-pressure must be greatly increased, and a large Fletcher's foot-blower or, better still, a small double-action bellows worked with vigour will be found very suitable. A fitting for this auxiliary blow-pipe is shown in Fig. 5 at B. Professor Roentgen's discovery has recently made it necessary to give more particular attention to the working of soft soda glass, and I have been obliged to supplement the arrangements described by a table especially intended for work with glass of this character. The arrangement has proved so convenient for general work that I give the following particulars. The table measures 5 feet long, 2 feet 11 inches wide, and is 2 feet 9 inches high. Fig. 7. It is provided with a single gas socket, into which either a large or small gas tube may be screwed. The larger tube is 5.5 inches long and 0.75 of an inch in diameter. The smaller tube is the same length, and half an inch in diameter. The axis of the larger tube is 3.5 inches above the table at the point of support, and is inclined to the horizontal at an angle of 12°. The axis of the smaller tube is 2.5 inches above the surface of the table, and is inclined to the horizontal at the same angle as the larger one. The air jets are simply pieces of glass tube held in position by corks. The gas supply is regulated by a well-bored tap. The air supply is regulated by treading the bellows--no tap is requisite. The bellows employed are ordinary smiths' bellows, measuring 22 inches long by 13 inches wide in the widest part. They are weighted by lead weights, weighing 26 lbs. The treadle is connected to the bellows by a small steel chain, for the length requires to be invariable. As the treadle only acts in forcing air from the lower into the upper chamber of the bellows, a weight of 13 lbs. is hung on to the lower cover, so as to open the bellows automatically. The air jets which have hitherto been found convenient are: for the small gas tube (1) a tube 0.12 inch diameter drawn down to a jet of 0.032 inch diameter for small work; (2) plain tubes not drawn down of 0.14 inch, 0.127 inch, and -0.245 inch diameter, and for the large gas tube, plain tubes up to 0.3 inch in diameter. The table is placed in such a position that the operator sits with his back to a window and has the black calico screen in front of him and to his right. The object of the screen is to protect the workman against draughts. The table is purposely left unscreened to the left of the workman, so that long tubes may be treated. § 17. Other appliances which will be required for glass-blowing are of the simplest character. (1) Small corks for closing the ends of tubes. (2) Soft wax--a mixture of bees' wax and resin softened by linseed oil to the proper consistency, easily found by trial, also used for temporarily closing tubes. (3) A bottle of vaseline for lubricating. (4) An old biscuit tin filled with asbestos in shreds, and an asbestos towel or cloth for annealing glass after removal from the flame. As asbestos absorbs moisture, which would defeat its use as an annealing material, it must be dried if necessary. (5) A Glass-Cutter's Knife. This is best made out of a fine three-cornered file, with the file teeth almost ground out, but not quite; it should be about 2 inches long. After the surface has been ground several times, it may be necessary to reharden the steel. This is best done by heating to a full red and quenching in mercury. The grindstone employed for sharpening the knife should be "quick," so as to leave a rough edge. I have tried many so-called glass knives "made in Germany," but, with one exception, they were nothing like so good as a small French or Sheffield file. In this matter I have the support of Mr. Shenstone's experience. (6) A wire nail, about 2 inches long, mounted very accurately in a thin cylindrical wooden handle about 5 inches long by one-quarter of an inch diameter, or, better still, a bit of pinion wire 6 inches long, of which 1.5 inches are turned down as far as the cylindrical core, An old dentists' chisel or filling tool is also a very good form of instrument. (7) A bit of charcoal about 3.5 inches long and 2 wide, and of any thickness, will be found very useful in helping to heat a very large tube. The charcoal block is provided with a stout wire handle, bent in such a manner that the block can be held close above a large glass tube on which the flames impinge. In some cases it is conveniently held by a clip stand. By the use of such a slab of charcoal the temperature obtainable over a large surface can be considerably increased. I have seen a wine-glass (Venetian sherry-glass) worked on a table with four blow-pipes, such as is here described, with the help of a block of hard wood held over the heated glass, and helping the attainment of a high temperature by its own combustion. (8) Several retort stands with screw clips. (9) Some blocks of wood about 5" X 2" X 2" with V-shaped notches cut in from the top. (10) A strong pair of pliers. (11) An apparatus for cleaning and drying the breath, when blowing directly by the mouth is not allowable. The apparatus consists of a solid and heavy block of wood supporting a calcium-chloride tube permanently connected with a tube of phosphorus pentoxide divided into compartments by plugs of glass wool. Care should be taken to arrange these tubes so as to occupy the smallest space, and to have the stand particularly stable. The exit tube from the phosphorus pentoxide should be drawn down to form a nozzle, from, say, half an inch to one-eighth of an inch in diameter, so as to easily fit almost any bit of rubber tube. The entry to the calcium chloride should be permanently fitted to about a yard of fine soft rubber tubing, as light as possible. The ends of this tube should terminate in a glass mouthpiece, which should not be too delicate. As an additional precaution against dust, I sometimes add a tube containing a long plug of glass wool, between the phosphorus pentoxide and the delivery tube, and also a tube containing stick potash on the entry side of the calcium chloride tube, but it may safely be left to individual judgment to determine when these additions require to be made. In practice I always keep the affair set up with these additions. The communication between all the parts should be perfectly free, and the tubes should be nearly filled with reagents, so as to avoid having a large volume of air to compress before a pressure can be got up. The arrangement will be clear by a reference to Fig. 8, which illustrates the apparatus in use for joining two long tubes. I have tried blowing-bags, etc, but, on the whole, prefer the above arrangement, for, after a time, the skill one acquires in regulating the pressure by blowing by the mouth and lips is such an advantage that it is not to be lightly foregone. Fig. 8. § 18. The Table. The system of four blow-pipes is, of course, a fixture. In this case the table may be about a yard square, and may be covered with asbestos mill-board neatly laid down, but this is not essential. The table should have a rim running round it about a quarter of an inch high. The tools should be laid to the right of the worker, and for this purpose the blow-pipes are conveniently fixed rather to the left of the centre of the table, but not so far as to make the leg of the table come so close to the operator as to make him uncomfortable, for a cheerful and contented spirit ought to be part of the glass-worker's outfit. The most convenient height for a blow-pipe table--with the blow-pipes about 2 inches above the table top--is 3 feet 2 inches. Nothing is so convenient to sit upon as a rough music-stool with a good range of adjustment. The advantage of an adjustable seat lies in the fact that for some operations one wants to be well over the work, while in others the advantage of resting the arms against the table is more important. § 19. Special Operations. The preliminary to most operations before the blow-pipe, is to draw down a tube and pull it out to a fine point. This is also the operation on which a beginner should exercise himself in the first instance. I will suppose that it is desired to draw out a tube about one-quarter of an inch in diameter, with the object of closing it, either permanently or temporarily, and leaving a handle for future operations in the shape of the point, thin enough to cool quickly and so not delay further work. For this simple operation most of the glass-blower's skill is required. The tube must be grasped between the first finger and thumb of both hands, and held so that the part to be operated on lies evenly between the two hands. The distance between the operator's thumbs may conveniently vary from 2.5 to 4 inches. Releasing the grip of the left hand, let the operator assure himself of his ability to easily rotate the tube about its axis--by the right thumb and finger--he will incidentally observe by the "feel" whether the tube is straight or not. A good deal of progress can be made from this point before the tube is heated at all. The operator can acquire a habit of instinctively rotating the tube by both hands, however the tube itself be moved about in space, or however it be pushed or pulled. The habit of constant and instinctive rotation is literally about one-third of the whole art of glassblowing. It is unlikely, however, that the beginner will discover that he has not got this habit, until a few failures draw his attention to it. The glass tube being held in position lightly yet firmly, and the operator being sure that he feels comfortable and at his ease, and that the blow-pipe flame (a single flame in this instance) is well under control, the preliminary heating may be commenced. With a tube of the dimensions given this is a very simple affair. Turn the air partly off, or blow gently, to get a partly luminous gas flame; hold the tube about an inch from the end of this flame, and turn it round and round till it commences to soften. In the case of soda glass it is usual to employ the gas flame only, but I find that it is better in most cases to use the hot air of a gently-blown flame, rather than have the disadvantage of the soot deposited in the alternative operation. When the glass begins to soften, or even before, it may be moved right into the blow-pipe flame, and the latter may be properly urged. It is not possible to give quite explicit and definite instructions, applicable to every case, as to when the time is ripe for passing the work into the flame, but the following notes will indicate the general rules to be observed:- (1) A thick tube must be warmed more slowly and raised to a higher temperature than a thin tube. (2) The same remark applies to a tube of large diameter, as compared with one of small diameter, whatever the thickness. (3) In the case of very large or thick tubes the hot air is advantageously employed at first, and to complete the preliminary heating, the luminous flame alone may be used. The object of this is to enable the operator to judge, by the presence of soot, its inability to deposit--or its burning off if deposited--of the temperature of the glass, and of the equality of this temperature all over the surface, for a large and thick tube might be heated quite enough to enable it to be safely exposed to the full heat before it is appreciably yielding to the fingers. In general, when the soot burns off freely, or lead glass begins to show the faintest sign of reduction, or soda glass begins to colour the flame, it is more than safe to proceed. In order to turn on the full flame the operator will form a habit of holding the work in the left hand only, and he will also take care not to let anything his right hand may be doing cause him to stop rotating the tube with his left thumb and finger. The preliminary adjustment of air or oxygen supply will enable the change to a flame of maximum power to be made very quickly. The tube having been introduced with constant rotation, it will soon soften sufficiently to be worked. The beginner will find it best to decide the convenient degree of softness by trial. With soda glass it does not much matter how soft the glass becomes, for it remains viscous, but with lead glass the viscosity persists for a longer time and then suddenly gives place to a much greater degree of fluidity. [Footnote: This is only drawn from my impressions acquired in glass-working. I have never explicitly tested the matter experimentally.] It is just at this point that a beginner will probably meet with his first difficulty. As soon as the glass gets soft he will find that he no longer rotates the glass at the same speed by the right and left hand, and, moreover, he will probably unconsciously bend the tube, and even deform it, by pushing or pulling. The second third of the art of the glass-blower consists in being able to move both hands about, rotating a tube with each thumb and finger, and keeping the distance between the hands, and also the speed of rotation, constant. Nothing but long practice can give this facility, but it is essential that it be acquired to some extent, or no progress can be made. Some people acquire a moderate proficiency very quickly, others, of whom the writer is one, only become reasonably proficient by months, or even years, of practice. Supposing that the tube is now ready to be drawn down, the operator will remove it from the flame, and will gently pull the ends apart, interrupting his turning as little as possible. If the tube be pulled too hard, or if the area heated be too small (about three-eighths of an inch in length in the case given would be proper), it will be found that the ends of the two portions of the tube will be nearly closed at a very sharp angle (nearly a right angle to the length of the tube), that the ends will be thin, and that a long length of very fine tube will be produced. To heat a short length of tube and pull hard and suddenly is the proper way to make a very fine capillary tube, but, in general, this is what we want to avoid. If the operation be successfully performed, the drawn-down tube will have the appearance exhibited, which is suitable either for subsequently closing or handling by means of the drawn-down portion. The straightness of the point can be obtained by a little practice in "feeling" the glass when the tube is rotated as it cools just before it loses its viscous condition. When the operation is carried out properly the shoulder of the "draw" should be perfectly symmetrical and of even thickness, and its axis regarded as that of a cone should lie in the axis of the tube produced. The operation should be repeated till the student finds that he can produce this result with certainty, and he should not be discouraged if this takes several days, or even weeks. Of course, it is probable that within the first hour he will succeed in making a tolerable job, but it is his business to learn never to make anything else. Fig. 9. Fig. 10. Diagram of a folded end. § 20. Closing and blowing out the End of a Tube. When it is desired to close the end of a particular bit of tube, this is easily done by heating the end, and at the same time heating the end of a waste bit of tube or rod; the ends, when placed in contact, stick together, and a point can be drawn down as before. [Footnote: "Point" is here used in the technical sense, i.e. it is a thin tail of glass produced by drawing down a tube.] Having got a point, it will be found that the thin glass cools enough to allow of the point being handled after a few moments. The most convenient way of reducing the point to a suitable length (say 1.5 inch) is to fuse it off in the flame, but this must be done neatly; if a tail is left it may cause inconvenience by catching, or even piercing the finger and breaking off. The blow-pipe flame being turned down to a suitable size, and the shoulder of the "draw" having been kept warm meanwhile, let the tip of the flame impinge on a point where the diameter is about half that of the undrawn tube, and let the temperature be very high (Fig. 11). The tube is to be inclined to the flame so that the latter strikes the shoulder normally, or nearly so. Then, according to circumstances, little or much of the glass can be removed at will by drawing off the tail (Fig. 12), till, finally, a small drop of melted glass only, adheres to the end of the now closed tube (Fig. 13). Fig. 11. Fig. 12. Fig. 13. Fig. 14. When this is satisfactorily accomplished, heat the extreme end of the tube most carefully and equally, holding it in such a position that the glass will tend to flow from the bead back on to the tube, i.e. hold the closed end up to the flame, the tube being, say, at 45 degrees to the horizontal. Then when the temperature is such as to indicate complete softness lift the tube to the mouth, still holding the tube pointing with its closed end a little above the horizontal, and blow gently. A beginner almost always blows too hard. What is wanted, of course, is a continued pressure, to give the viscous glass time to yield gradually, if it is uniform; or else intermittent puffs to enable the thinner parts, if there are any, to cool more, and hence become more resisting than the thicker ones. In any case a little practice will enable the operator to blow out a round and even end--neither thicker nor thinner than the rest of the tube. § 21. To make a Weld. To begin with, try on two bits of glass of the same size, i.e. cut a seven-inch length of glass in half by scratching it with the knife, and pulling the ends apart with a slight inclination away from the scratch. In other words, combine a small bending moment with a considerable tensional stress. It is important to learn to do this properly. If the proportions are not well observed, the tube will break with difficulty, and the section will not be perpendicular to the main length. If the knife is in good order it will make a fine deep scratch--the feel of the glass under the knife will enable the operator to decide when the scratch is made. The operation of cutting large tubes will be treated further on. The two halves of the tube being held one in each hand, and one tube closed at one end, the extremities to be united will be warmed, and then put in the flame as before. Fig. 16. There are many ways of proceeding--perhaps the easiest is as follows. As soon as the glass shows signs of melting at the ends--and care should be taken that much more is not heated--take both bits out of the flame. Stop rotating for a moment, and resting the arms carefully on the edge of the table, raise the tubes above the flame and bring the ends swiftly and accurately together. This is a case of "sudden death no second attempt at making the ends meet can be allowed; if the tubes join in any other than a perfectly exact manner a kink more or less objectionable will result. In practice the operator will learn to bring the ends together, commencing at one point; i.e. the axes of the tubes will be inclined at first, so as to cause adherence at one spot only. If this is not quite "fair", then less damage is done in moving one tube slightly up or down to get the contact exact. The tubes will then be closed upon one another as if they were hinged at the joint. This must be done lightly, yet sufficiently, to ensure that the glass is actually in contact all round. Having gone so far, replace the tubes--now one--in the flame, and carefully rotating the glass, raise the temperature higher than in the operation just described, in fact the higher the temperature, short of burning the glass, the better. Take the tube out of the flame and blow into the open end, turning constantly as before. One puff is enough. Then turn and pull the glass apart till it is of the same diameter and thickness throughout, and feel that it is straight as before. Though it is in general of high importance that the joint should be well heated, the beginner will probably find that he "ties up" his glass as soon as it gets really soft. If his object is to make one joint--at any cost--then let him be careful to use two bits of exactly the same kind of glass, and only get the temperature up to the viscous stage. If the joint be then pulled out till it is comparatively thin, it will probably stand (if of soda glass); certainly, if of lead glass, though in this case it may not be sound. In any case the joint should be annealed in the asbestos box if practicable, otherwise (unless between narrow tubes) with the asbestos rag. Care must be taken that the asbestos is dry. § 22. To weld two Tubes of different Sizes. To do this, the diameter of the larger tube must be reduced to that of the smaller. The general procedure described in drawing down must be followed, with the following modification. In general, a greater length of the tube must be heated, and it must be made hotter. The tube is to be gradually drawn in the flame with constant turning till the proper diameter and thickness of glass are attained. Fig. 16. For this operation time must be allowed if the operator's hands are steady enough to permit of it; the shoulder should form partly by the glass sinking in and partly by the process of drawing the hot glass out. A shoulder properly prepared is shown in the sketch. Beginners generally make the neck too thin on large tubes, and too thick on smaller ones. There ought to be no great difference in thickness of glass between the neck on the larger tube, and the smaller tube. The diameters should be as nearly as possible alike. Having drawn down the larger tube to a neck, take it out of the flame, and as it cools pull and turn till the neck is of the right thickness and is perfectly straight, i.e. make the final adjustment outside the flame, and to that end have the neck rather too thick (as to glass) before it is taken out. It is not necessary to wait till the neck gets cold before the end can be cut off. Make a scratch as before--this will probably slightly damage the temper of the file knife, but that must be put up with. Hold the tube against the edge of the table, so that the scratch is just above the level of the rim, and strike the upper part a smart blow with the handle of the glass knife rather in the direction of its length. [Footnote: A bit of hoop iron nailed against the side of the table is a very convenient arrangement, and it need not project appreciably above the general level of the rim.] Of course this applies to a tube where economy has been exercised and the end is short. If the tail is long enough to form a handle, the tube may be pulled apart as before. As a rule a temporary joint between a tube and a rod is not strong enough to enable the shoulder to be broken at the scratch by mere pulling. The ends to be welded must be broken off very clean and true. Subsequent operations are to be carried out as already described. § 23. The above operations will be easily performed on tubes up to half an inch in diameter, if they are not too long. It is the length of tube, and consequent difficulty in giving identity of motion with the two hands, which make the jointing of long tubes difficult. There are also difficulties if the tubes are very thin, have a very fine bore or a very large diameter. All these difficulties merely amuse a good glass-blower, but to an experimenter who wants to get on to other things before sufficient skill is acquired (in the movement of the hands and arms) the following method is recommended. First, use flint glass. Then, assuming that any drawing down has to be done, do it as well as possible, for on this the success of the method to be described especially depends. Be sure that the tubes to be welded are cut off clean and are as nearly as may be of the same size at the point of junction. To fix the description, suppose it is desired to join two tubes (see Fig. 8), each about one inch in diameter and a yard long. Get four clip stands and place them on a level table. Be sure that the stands are firm and have not warped so as to rock. In each pair of clips place a tube, so that the two tubes are at the same height from the table, and, in fact, exactly abut, with axes in the same straight line. Close one tube by a cork and then fix the blowing apparatus as shown to the other. In such an operation as this the drying apparatus may be dispensed with, and a rubber tube simply connected to one end of the system and brought to the mouth. Take the oxygen blow-pipe and turn the nozzle till the flame issues towards you, and see that the flame is in order. Then turn down the oxygen till it only suffices to clear the smoky flame, and commence to heat the proposed joint by a current of hot air, moving the flame round the joint. Finally, bring to bear the most powerful flame you can get out of the blow-pipe, and carry it round the joint so quickly that you have the latter all hot at once. Put down the blow-pipe, and, using both hands, press the tubes together (which wooden clips will readily allow), and after seeing that the glass has touched everywhere, pull the tubes a trifle apart. Apply the blow-pipe again, passing lightly over the thin parts, if any, and heating thicker ones; having the end of the rubber tube in his mouth, the operator will be able to blow out thick places. When all is hot, blow out slightly, and having taken the flame away, pull the tubes a little apart, and see that they are straight. Throw an asbestos rag over the joint, loosen one pair of the clamps slightly, and leave the joint to anneal. It is important that the least possible amount of glass should be heated, hence the necessity of having the ends well prepared, and it is also important that the work should be done quickly; otherwise glass will flow from the upper side downwards and no strong joint will be obtained. Fig. 17. Tube being opened at one end. § 24. To weld Tubes of very small Bore. If the bore is not so small as to prevent the entrance of the point of the iron nail, get the ends of the tubes hot, and open the bore by inserting the end of the nail previously smeared over with a trace of vaseline. Work the nail round by holding the handle between the thumb and first finger of the right hand, the tube being similarly placed in the left. The tube and nail should be inclined as shown in the sketch. Never try to force the operation; the nail soon cools the glass, so that only a very short time is available after each heat; during this the tube should be rotated against the nail rather than the nail against the tube. Be careful not to heat a greater length of tube than is necessary, or the nail will, by its component of pressure along the tube, cause the latter to "jump up" or thicken and bulge. Both ends being prepared, and if possible, kept hot, the weld may be made as before, and the heating continued till the glass falls in to about its previous thickness, leaving a bore only slightly greater than before. It is in operations such as this that the asbestos box will be found of great use. As soon as one end of the weld is ready cool it in the flame till soot deposits, and then plunge it into the asbestos. This will cause it to cool very slowly, and renders it less likely to crack when again brought into the flame. Turned-out ends, if the glass is at all thick, are very liable to crack off on reheating, so that they must be reintroduced (into the flame) with especial care. This liability to breakage is reduced, but not eliminated, by the asbestos annealing. Figs. 18 and 19. § 25. When the bore is very fine, it is best to seal off the tubes, and blow an incipient bulb near one end of each tube. These bulbs may be cooled in asbestos, and cut across when cold by means of a scratch touched at one end (Figs. 18 and 19) by a fine point of highly incandescent glass. For details of this method see p. 46, Fig. 21. Time is occasionally saved by blowing off the ends of the bulbs. The details of this process will be described when the operation of making thistle-headed tubes is dealt with. § 26. When the tubes are both of large diameter, long, and very thin (cylinder tubes), a considerable amount of difficulty will be experienced. On the whole, it is best to heat each end separately till the glass thickens a little, anneal in the flame and in asbestos, and then proceed as in § 22. If the ends are not quite true, it will be found that quite a thickness of glass may be "jumped" together at one side of the tubes, while the edges are still apart at the other. When this looks likely to happen, incline the tubes as if the joint were a hinge, and bend back quickly; do not simply continue to push the tubes together in a straight line, or an unmanageable lump of glass will be formed on one side. If in spite of these precautions such a lump does form, proceed as follows. Take a rod of glass, at least one-eighth of an inch thick, and warm it in the flame at one end. Heat the imperfect joint till it softens all round, and then bring the flame right up to the thick part, and heat that as rapidly and locally as possible. The oxygas flame does this magnificently. Press the heated end of the glass rod against the thick part, and pull off as much of the lump as it is desired to remove, afterwards blowing the dint out by a judicious puff. Finish off as before. § 27. Occasionally, when it is seen that in order to produce a joint closed all round, one side of the tube would be too much thickened, it is better to patch the open side. For this purpose take a glass rod about one-sixteenth inch in diameter, and turn the flame to give its greatest effect, still keeping rather an excess of air or oxygen. See that the side of the joint already made is kept fairly hot--it need not be soft; interrupt any other work often enough to ensure this. Then, directing the flame chiefly on the thin rod, begin to melt and pull the glass over the edges of the gap. When the gap is closed get the lump very hot, so that all the glass is well melted together, and then, if necessary, pull the excess of glass off, as before described. It must be remembered that this and the method of the previous section are emergency methods, and never give such nice joints as a manipulation which avoids them, i.e. when the ends of the tubes are perfectly straight and true to begin with. Also note that, as the tubes cannot be kept in rotation while being patched, it is as well to work at as low a temperature as possible, consistently with the other conditions, or the glass will tend to run down and form a drop, leaving a correspondingly thin place behind. Fig. 20. § 28. A very common fault in cutting a tube of about an inch in diameter is to leave it with a projecting point, as shown. This can be slowly chipped off by the pliers, using the jaws to crush and grind away the edge of the projection; it is fatal to attempt to break off large pieces of glass all at once. § 29. It will be convenient here to mention some methods of cutting large tubes. With tubes up to an inch and a half in diameter, and even over this--provided that the glass is not very thick--we may proceed as follows: Make a good scratch about half an inch long, and pretty deep, i.e. pass the knife backwards and forwards two or three times. Press a point of melted glass exactly on one end of the scratch; the glass point even when pressed out of shape should not be as large as a button one-twelfth of an inch in diameter. If this fails at first, repeat the operation two or three times. Fig. 21. If a crack does not form, touch the hot place with the cold end of the nail. If no success is obtained, try the other end of the scratch. If failure still pursues the operator, let him make another cut on the opposite side of the tube and try again. In general, the tube will yield the first or second time the hot drop of glass is applied. Never apply the drop at the centre of the scratch, or a ragged crack, which may run in any direction, will result. Very often, with a large tube, the crack formed by a successful operation will only extend a short distance. In this case it is desirable to entice the crack round the tube, and not trust to its running straight when the tube is pulled apart. On the whole, the best method in this case is to employ a flame pencil, which should be kept ready for use. This merely consists of a bit of glass tube of about the same dimensions as an ordinary lead pencil, drawn down to a very fine jet at one end. The jet must not be very long or thin, or the glass will soon fuse up. A few trials will enable the operator to get the proper proportions, which are such that the tube has the general appearance of a pencil normally sharpened (say with a cone of 60'). This tube is best made of hard glass. Connect it to a gas supply by light flexible tubing, and turn down the gas till the flame from the end of the jet is not more than one-tenth of an inch long. Then apply the jet, beginning from the end of the crack, and gradually draw it (the crack) round the tube. The operation will be assisted if a rubber ring is slipped on the tube to begin with, so that the eye has some guide as to whether the flame is being drawn round properly or not. The ring must, of course, be far enough away to escape the effect of the flame. The crack will be found to follow the flame in the most docile manner, unless the tube is thick or badly annealed. Some operators recommend a pencil of glowing charcoal, but the flame is undoubtedly better. § 30. To cut very thick Tubes. A large number of methods have been proposed, and nearly everybody has his favourite. The following has always succeeded with me. First mark on the tube, by means of a little dead black spirit paint, exactly where the cut is to be. Then sharpen the glass knife and scratch a quite deep cut all round: there is no difficulty in making the cut one-twentieth of an inch deep. It will be proper to lubricate the knife with kerosene after the first mark is made. [Footnote: The edge of the knife may be advantageously saved by using an old file moistened with kerosene for the purpose. I find kerosene is not worse, but, if anything, better than the solution of camphor in turpentine recommended by Mr. Shenstone.] If the glass is about one-eighth of an inch thick, the scratch maybe conveniently about one-twentieth of an inch deep, but if the glass is anything like one-quarter of an inch thick, the scratch must be much deeper, in fact, the glass may be half cut through. To make a very deep scratch, a wheel armed with diamond dust, which will be described later on, may be used. However, it is not essential to use a diamond wheel, though it saves time. When the cut is made to a sufficient depth proceed thus: Obtain two strips of bibulous paper or bits of tape and twist them round the tube on each side of the scratch, allowing not more than one-eighth of an inch between them. Then add a few drops of water to each, till it is thoroughly soaked, but not allowing water to run away. Dry out the scratch by a shred of blotting paper. Turn down the oxygas flame to the smallest dimensions, and then boldly apply it with its hottest part playing right into the nick and at a single point. Probably in about two seconds, or less, the tube will break. If it does not, rotate the tube, but still so that the flame plays in the nick. After making the tube very hot all round--if it has not broken--apply the flame again steadily at one point for a few seconds and then apply a bit of cold iron. If the tube does not break at once during these processes, let it cool, and cut the groove deeper; then try again. [Footnote: This method is continually being reinvented and published in the various journals. It is of unknown antiquity.] Fig. 22. If the tube breaks after great heating and long efforts, it will probably leave incipient cracks running away from the break, or may even break irregularly. A good break is nearly always one that was easily made. If a number of rings have to be cut, or a number of cuts made on glass tubes of about the same size, it will be found economical in the end to mount a glazier's diamond for the purpose. A simple but suitable apparatus is figured (Fig. 23). Fig. 23. The only difficulty is to regulate the position of the diamond so that it cuts. In order to do this, carefully note its cutting angle by preliminary trials on sheet glass, and then adjust the diamond by clamps, or by wriggling it in a fork, as shown. Weight the board very slightly, so as to give the small necessary pressure, and produce the cut by rotating the tube by hand. When a cut is nearly completed take great care that the two ends join, or irregularity will result. This is not always easy to do unless the tube happens to be straight. Having got a cut, start a crack by means of a fine light watchmaker's hammer, or even a bit of fused glass, and entice the crack round the cut by tapping with the hammer or by means of the flame pencil. If the cut is a true "cut" the tube will break at once. As a supply of electrical current for lighting will, in the near future, be as much a matter of course for laboratory purposes as a gas supply, I add the following note. To heat a tube round a scratch, nothing--not even the oxygas blow-pipe--is so good as a bit of platinum or iron wire electrically heated. If the crack does not start by considerable heating of the glass, stop the current, unwind the wire, and touch the glass on the crack either with a bit of cold copper wire or a wet match stem. I prefer the copper wire, for in my experience the water will occasionally produce an explosion of cracks. On the other hand, the cold wire frequently fails to start a crack. Judging from the appearance of thick tubes as supplied by the dealers, the factory method of cutting off appears to be to grind a nick almost through the tube, and right round; and for really thick glass this is the safest but slowest way; a thin emery wheel kept wet will do this perfectly. Suitable wheels may be purchased from the "Norton" Emery Wheel Co. of Bedford, Mass, U.S.A.--in England through Messrs. Churchill and Co. of London, importers. § 31. To blow a Bulb at the End of a Tube. I must admit at once that this is a difficult operation--at all events, if a large bulb is required. However, all there is to be said can be said in few words. In general, when a bulb is required at the end of a tube it will be necessary to thicken up the glass. A professional glass-worker will generally accomplish this by "jumping up" the tube, i.e. by heating it where the bulb is required, and compressing it little by little until a sufficient amount of glass is collected. The amateur will probably find that he gets a very irregular mass in this way, and will be tempted to begin by welding on a short bit of wide and thick tubing preparatory to blowing out the bulb. However, supposing that enough glass is assembled by-either of these methods, and that it is quite uniform in thickness, let the thickened part be heated along a circle till it becomes moderately soft, and let it then be expanded about one-fifth, say by gently blowing. It is perhaps more important to keep turning the glass during bulb-blowing than in any other operation, and this both when the glass is in the flame and while the bulb is being blown. It is also very important to avoid draughts. In general, a bulb is best blown with the tube in a nearly horizontal position, but sloping slightly upwards from the mouth. If it be noticed that a bulb tends to blow out more at one side than another, let the side of greatest protuberance be turned down, so that it is at the lowest point, reduce the pressure for an instant, and then blow again. It will be observed that the bulb will now expand at the top. The reason of this is chiefly that the under side cools most rapidly (according to Faraday, Chemical Manipulation, § 1194), and consequently can expand no further; but also it is not unlikely that the glass tends to flow somewhat from the upper side, which remains hot, and consequently the bulb, when the next puff reaches it, will tend to yield at this point. By heating several zones the tube will become gradually expanded. Fig. 24. Fig. 25. Fig. 26. When the length of the thickened part of the tube only slightly exceeds its diameter (Fig. 25), let the whole be brought to a temperature which, with flint glass, should be just short of that of perfect fluidity; and then, holding the tube horizontally and constantly turning it, let the bulb be blown out to its full size, noting the appearances and correcting too great protuberance on any side by the means above mentioned. If the bulb appears pear-shaped turn the tube so that the melted mass is directed upwards; if the bulb have the contrary fault, correct in the corresponding manner. The bulb when finished may be lightly tapped on the table, when, if there is any weak place owing to inequality of thickness, the bulb will break, and the operation may be started afresh. "A good bulb is round, set truly on the tube, and free from lumps of thick glass or places of excessive thinness." When the amateur has succeeded in blowing a bulb two inches in diameter on the end of a strong bit of thermometer tube--say for an air thermometer--he may well seek the congratulations of his friends. In case the bulb is not satisfactory on a first attempt, it may be melted down again, if the following precautions are taken. Directly creases begin to appear in the bulb let it be withdrawn from the flame, and gently blown till the creases come out. By alternate heating and blowing the glass can be got back to its original form, or nearly so, but unless the operator shows great skill and judgment, the probability is that the glass will be uneven. By heating and keeping the thicker parts in the higher position, and blowing a little now and again, the glass may be got even, and a new attempt may be made. It must not be supposed that this process can be carried on indefinitely, for the glass tends to lose its viscous properties after a time, or, at all events, it "perishes" in some way, especially if it has been allowed to get very thin; consequently too frequent attempts on the same glass are unprofitable. Two or three trials are as many as it generally pays to make. As a rule the largest possible flame may be used with advantage in this operation. § 32. To blow a bulb in the middle of a tube, the procedure is much like that already treated, but the manipulation is, if anything, more difficult, for the further end of the tube must be carried and turned as well as the end which is held to the lips. § 33. To make a side Weld. This is by no means difficult, but is easier with lead glass than with soda glass. The tube to which it is desired to make a side connection having been selected, it is closed at one end by rubber tube stops, or in any other suitable manner. The zone of the proposed connection is noted, and the tube is brought to near softness round that circle (if the tube is made actually soft, inconvenience will arise from the bending, which is sure to occur). Two courses are then open to the operator, one suitable to a thick tube, the other to a tube of moderate thickness. Taking the former first. Provide a piece of glass rod and warm its end. Direct a small flame against the spot on the thick tube where the proposed joint is to be. When the glass becomes almost incandescent at this spot, put the end of the rod against it and draw out a thread of glass till sufficient "metal" has been removed. Then fuse off the thread close to the tube. Fig. 27. The subsequent procedure is the same as for thin tubes. In this case heat the spot by the smallest flame available, and get the spot very hot. Blow it out gently into a bubble, perhaps extending to a height equal to its diameter. Then heat the top of the bubble till it is incandescent and blow violently. This will produce an opening fringed by glass so thin as to exhibit interference colours. Remove the filmy part, and heat the frayed edges till they cohere and form an incipient tube. If the flame has been of a correct size, the tube will now be of the same diameter as the tube to be welded on, and will project perhaps one-sixteenth of an inch from the surface of the main tube (Fig. 28). Fig. 28. Fig. 29. When this stage is reached, again heat the tube all round till it nearly softens, and by means of the other hand heat the end of the other tube which it is proposed to weld. Just before the main tube actually softens, turn it so as to heat the edges of the aperture, and at the same time get the end of the side tube very hot. Take both out of the flame for an instant, and press the parts together, instantly slightly withdrawing the side tube. If the operation is well performed, it will be found that the point of maximum thickness of glass is now clear of the main tube. The joint is then to be heated all round and blown out--a rather awkward operation, and one requiring some practice, but it can be done. Fig. 30. If great strength is wanted, heat the main tube all round the joint bit by bit, and blow each section slightly outwards. If the operator is confident in his skill, he should then heat the whole joint to the softening point, blow it out slightly, and then adjust by pulling and pushing. Cool first in the gas flame, and then plunge the joint into the asbestos and cover it up--or if too large, throw the asbestos cloth round it. In the case of soda glass this final "general heat" is almost essential, but it is not so with flint glass, and as the general heat is the most difficult part of the job, it will be found easier to use lead glass and omit the general heating. With soda glass a very small irregularity will cause the joint to break when cold, but flint glass is much more long-suffering. It is easy to perform the above operation on small tubes. For large ones it will be found best to employ flint glass and use the clip stands as in the case of direct welds, treated above, but, of course, with suitable modifications. Never let the main tube cool after the hole is made until the work is done. § 34. Inserted Joints. In many instances the performance of apparatus is much improved by joints of this kind, even when their use is not absolutely essential. There are two ways in which inserted joints may be made. The first method is the easier, and works well with flint glass; but when one comes to apply it to soda glass there is a danger of the glass becoming too thick near the joint, and this often leads to a cracking of the joint as the glass cools. Fig. 31. Suppose it is desired to insert the tube B into the tube A (Fig. 31). Begin by reducing the size of the end of tube A till B will just slip in quite easily. With B about one-quarter inch in diameter, a clearance of about one-twentieth of an inch, or less, in all (i.e. one-fortieth of an inch on each side) will be proper. Heat B by itself at the proposed zone of junction, and blow out a very narrow ring; then compress this slightly so that it forms an almost closed ring of glass. The figure refers to the close of this operation (Fig. 31, B). It does not matter much whether the ring remains a mere flattened bulb, or whether it is a solid ring, but it must be one or the other. Some judgment must be exercised in preparing the ring. In general, the beginner will collect too much glass in the ring, and consequently the joint, when made, will either be thick and liable to crack easily, or it will be blown out into an erratic shape in endeavours to reduce this thickness. Accordingly, the operator will, if necessary, thin the tube B by drawing slightly, if he considers it desirable, before the little enlargement is blown out. In general, two heats must be used for this operation. Fig. 32. Get the approximating parts of both A and B up to a temperature just below that at which they will adhere, and having closed the other end of A, place B carefully within it up to the ring, and if it can be arranged, have a mica wad in A, with a central hole through which the end of B can project. This will very much facilitate the operation, especially if B is long, but may be dispensed with by the exercise of care and skill. The operation is now simple. Fuse the junction and press the tubes lightly together, being careful not to collect more glass than can be helped; finally, blow out the joint and reduce the thickness by mild drawing (Fig. 33). In order to make a really good joint, two points must be particularly attended to--the rim must be thin and its plane perfectly perpendicular to the axis of tube B; the end of tube A must be cut off quite clean and perpendicular to its axis before B is inserted. So important are these conditions--especially the latter that the writer has even occasionally used the grindstone to get the end of A into a proper condition, an admission which will probably earn the contempt of the expert glass-worker. Fig. 33. Now for the second method, which is often practised in Germany, where soda glass is chiefly used. With this glass the chief point is to get a very even and not too thick ring at the junction, and consequently the extra thickening produced by making a rim on B is rather a drawback. The method consists in cutting off from B the length which it is desired to insert, slipping this into A (which may be an otherwise closed bulb, for instance), and then gradually melting up the open end of A till the piece of B inside will no longer fall out. By holding the joint downwards so that the inserted portion of B rests on the edges of the opening, a joint may be made with the minimum thickening. The external part of B, previously heated, is then applied, and the joint subjected to a "general" heat and blown out. Very nice joints may be made by this method, and it is perhaps the better one where the external part of B is to be less in diameter than the inserted part. It was in this manner that the writer was taught to make glass velocity pumps, one of which, of a good design, is figured as an example. In all cases good annealing should follow this operation. If the inserted part of the inner tube (B) is anything like an inch in diameter, and especially if it is of any length, as in some forms of ozone apparatus, or in a large Bunsen's ice calorimeter, the arrangements for supporting the inner part must be very good. A convenient way of proceeding when the inner tube is well supported is to make the mouth of A only very little larger than the diameter of B, so that B will only just slip in. Then the mouth of A and the zone of B may be heated together, and B blown out upon A. This, of course, must be arranged for, if necessary, by temporarily stopping the inner end of B. The inner support of B should be removed as soon as practicable after the joint is made, or, at all events, should not be perfectly rigid; a tightly-fitting cork, for instance, is too rigid. The reason is, of course, that in cooling there may be a tendency to set B a little to one side or the other, and if it is not free to take such a set, the joint most probably will give way. Good annealing both with flame and asbestos is a sine qua non in all inserted work. Fig. 34. § 35. Bending Tubes. I have hitherto said nothing about bending tubes, for to bend a tube of a quarter of an inch in diameter, and of ordinary thickness, is about the first thing one learns in any laboratory, while to bend large tubes nicely is as difficult an operation as the practice of glass-blowing affords. However, even in bending a narrow tube it is possible to proceed in the wrong way. The wrong way is to heat a short length of the tube and then bend it rapidly, holding the plane of the bend horizontal. The right way, per contra, is to use a batswing burner to heat, say, two inches of the tube with constant turning till it is very soft, and then, holding the glass so that the bend will be in a vertical plane passing through one eye (the other being shut), to make the bend rather slowly. If an exact angle is required, it is as well to have it drawn out on a sheet of asbestos board. In this case bend the glass as described till it is approximately right, and finish by laying it on the asbestos board and bringing it up to the marks. A suitable bit of wood may be substituted for the asbestos on occasion. N.B: The laboratory table is not a suitable piece of wood. A right-angled bend is often wanted. In this case the corner of a table will serve as a good guide to the eye, the glass being finished by being held just above it. If great accuracy is wanted, make a wooden template and suspend it by a screw from the side of the table, so that the vertex of the gauge for the interior angle projects downwards, then finish by bending the tube round it. The wood may be about half an inch thick. If a sharp bend is required, heat the tube in the blow-pipe, and bend it rapidly, blowing out the glass meanwhile. The reason why a long bend should be held in a vertical plane is that the hot part tends to droop out of the plane of the bend if the latter be made in a horizontal position. To bend a tube above half an inch in diameter is a more or less difficult operation, and one which increases in difficulty as the diameter of the tube increases. A U-tube, for instance, may be made as follows: Use the four blow-pipe arrangement so as to heat a fair length of tube, and get, say, two inches of tube very hot--almost fluid, in fact--by means of the carbon block supported from a stand. Remove the tube rapidly from the flame and draw the hot part out to, say, three inches. Then, holding the tube so as to make the bend in a vertical plane, bend it and blow it out together to its proper size. This operation seems to present no difficulties to experienced glass-workers, even with tubes of about one inch in diameter, but to the amateur it is very difficult. I always look on a large U-tube with feelings of envy and admiration, which the complex trick work of an elaborate vacuum tube does not excite in the least. It will be noted that this method may, and often does, involve a preliminary thickening of the glass. With tubes over an inch in diameter I have no idea as to what is the best mode of procedure--whether, for instance, a quantity of sand or gas coke might not be used to stuff out the tube during bending, but in this case there would be the difficulty of removing the fragments, which would be sure to stick to the glass. Of course, if the bend need not be short, the tube could be softened in a tube furnace and bent in a kind of way. I must admit that with tubes of even less than one inch in diameter I have generally managed best by proceeding little by little. I heat as much of the glass as I can by means of a gigantic blow-pipe, having a nozzle of about an inch in diameter, and driven by a machine-blower. When I find that, in spite of blowing, the tube begins to collapse, I suspend operations, reheat the tube a little farther on, and so proceed. If by any chance any reader knows a good laboratory method of performing this operation, I hope he will communicate it to me. After all, the difficulty chiefly arises from laboratory heating appliances being as a rule too limited in scope for such work. The bending of very thin tubes also is a difficulty. I have only succeeded here by making very wide bends, but of course the blowing method is quite applicable to this case, and the effect may be obtained by welding in a rather thicker bit of tube, and drawing and blowing it till it is of the necessary thinness. This is, however, a mere evasion of the difficulty. § 36. Spiral Tubes. These are easily made where good heating apparatus is available. As, however, one constantly requires to bend tubes of about one-eighth inch in diameter into spirals in order to make spring connections for continuous glass apparatus, I will describe a method by which this is easily done. Provide a bit of iron pipe about an inch and a quarter in outside diameter. Cover this with a thick sheath of asbestos cloth, and sew the edges with iron wire. Hammer the wire down so that a good cylindrical surface is obtained. Make two wooden plugs for the ends of the iron pipe. Bore one to fit a nail, which may be held in a small retort clip, and fasten a stout wire crank handle into the other one. Support the neck of the handle by means of a second clip. In this way we easily get a sort of windlass quite strong enough for our purpose. Fig. 35. Provide a large blow-pipe, such as the blow-pipe of a Fletcher crucible furnace, Select a length of tubing and clean it. Lash one end to the cylinder by means of a bit of wire, and hold the other end out nearly horizontally. Then start the blow-pipe to play on the tube just where it runs on to the asbestos cylinder, and at first right up to the lashing. Get an attendant to assist in turning the handle of the windlass, always keeping his eye on the tube, and never turning so fast as to tilt the tube upwards. By means of the blow-pipe, which may be moved round the tubing, heat the latter continuously as it is drawn through the flame, and lay it on the cylinder in even spirals. If the tubing is thin, a good deal of care will have to be exercised in order to prevent a collapse. A better arrangement, which, however, I have not yet tried, would, I think, be to replace the blow-pipe by two bats-wing burners, permanently fastened to a stand, one of them playing its flame downwards on to the top of the flame of the other. The angle between the directions of the jets might be, say, 130°, or whatever is found convenient. In this way the glass would not be so likely to get overheated in spots, and better work would doubtless result. However, I have made numbers of perfectly satisfactory spirals as described. Three or four turns only make a sufficiently springy connection for nearly all purposes. § 37. On Auxiliary Operations on Glass:- Boring Holes through Glass:- This is much more easily done than is generally supposed. The best mode of procedure depends on the circumstances. The following three cases will be considered:- 1. Boring holes up to one-quarter inch diameter through thick glass (say over one-eighth inch), or rather larger holes through thin glass. 2. Boring holes of any size through thick glass. 3. Boring round holes through ordinary window glass. § 38. Boring small Holes. Take a three-cornered file of appropriate dimensions, and snip the point off by means of a hammer; grind out most of the file marks to get sharp corners. Dip the file in kerosene, and have plenty of kerosene at hand in a small pot. Place the broken end of the file against the glass, and with considerable pressure begin to rotate it (the file) backwards and forwards with the fingers, very much as one would operate a bradawl against a hard piece of wood. The surface of the glass will shortly be ground away, and then the file bradawl will make much quicker progress than might be expected. Two or three minutes should suffice to bore a bit of sheet window-glass. The following points require attention: (1) Use any quantity of oil. (2) After getting through the skin reduce the pressure on the file. (3) Be sure to turn the file backwards and forwards through a complete revolution at least. (4) When the hole is nearly through reduce the pressure. (5) When the hole is through the glass be exceedingly careful not to force the file through too rapidly, otherwise it will simply act as a wedge and cause a complete fracture. (6) In many cases it is better to harden the file in mercury before commencing operations; both files and glass differ so much in hardness that this point can only be decided by a trial. If it is found necessary to harden the file, use either a large blow-pipe and a coke or charcoal bed, or else a small forge. A small blowpipe, such as is generally found in laboratories, does more harm than good, either by burning the end of the file or raising it to an insufficient temperature. (7) To sharpen the file, which is often necessary after passing through the "skin" of the glass, put it in a vice so that the point just protrudes clear of the jaws. Then, using a bit of waste iron as an intermediary anvil or punch, knock off the least bit from the point, so as to expose a fresh natural surface. The same result may be brought about by the use of a pair of pliers. If several holes have to be bored, it is convenient to mount the file in the lathe and use a bit of flat hard wood to press up the glass by means of the back rest. A drilling machine, if not too heavy, does very well, and has the advantage of allowing the glass to remain horizontal so that plenty of oil can be kept in the hole. Use a very slow speed in either case--much slower than would be used for drilling wrought iron. It is essential that the lubricant should flow on to the end of the file very freely, either from a pipette or from the regular oil-feed. If a little chipping where the file pierces the back surface is inadmissible, it is better, on the whole, to finish the bore by hand, using a very taper file. It is not necessary to use a special file for the lathe, for a well-handled file can be chucked very conveniently in a three-jaw chuck by means of the handle. Mr. Shenstone recommends a lubricant composed of camphor dissolved in turpentine for general purposes. With the object of obtaining some decisive information as to the use of this lubricant, and to settle other points, I made the following experiments. Using an old three-cornered French file, I chipped off the point and adjusted the handle carefully. I also ground out the file marks near the point, without hardening the file in mercury. Using kerosene and turpentine and camphor, I began to bore holes in a hard bit of 3/32 inch window glass. Each hole was bored to about one-eighth inch in diameter in four minutes with either lubricant. After hardening the file in mercury and using kerosene, I also required four minutes per hole. After mounting the file in a lathe which had been speeded to turn up brass rods of about one-half-inch diameter, and therefore ran too fast, I required one and a half minutes per hole, and bored them right through, using kerosene. On the whole, I think kerosene does as well as anything, and for filing is, I think, better than the camphor solution. However, I ought to say that the camphor-turpentine compound has probably a good deal to recommend it, for it has survived from long ago. My assistant tells me he has seen his grandfather use it when filing glass. I beg to acknowledge my indebtedness to Mr. Pye, of the Cambridge Scientific Instrument Company, for showing me in 1886 (by the courtesy of the Company) the file method of glass-boring; it is also described by Faraday in Chemical Manipulation, 1228. It is not necessary, however, to use a file at all, for the twist drills made by the Morse Drill Company are quite hard enough in their natural state to bore glass. The circumferential speed of the drill should not much exceed 10 feet per minute. In this way the author has bored holes through glass an inch thick without any trouble except that of keeping the lubricant sufficiently supplied. For boring very small holes watchmaker's drills may be used perfectly well, especially those tempered for boring hardened steel. The only difficulty is in obtaining a sufficient supply of the lubricant, and to secure this the drill must be frequently withdrawn. My reason for describing the file method at such length is to be found in the fact that a Morse drill requires to be sharpened after drilling glass before it can be used in the ordinary way, and this is often a difficulty. I ought to say that I have never succeeded in boring the barrel of a glass tap by either of these methods. [Footnote: I have been lately informed that it is usual to employ a splinter of diamond set in a steel wire holder both for tap boring and for drilling earthenware for riveting. The diamond must, of course, be set so as to give sufficient clearance for the wire holder. For methods of using and setting diamond tools see § 55. It will suffice to say here that a steel wire is softened and filed at one end so as to form a fork; into this the diamond is set by squeezing with pliers. The diamond is arranged so as to present a point in the axis of the wire, and must not project on one side of the wire more than on the other. It is not always easy to get a fragment satisfying these conditions, and at the same time suitable for mounting. A drop of solder occasionally assists the process of setting the diamond. In drilling, the diamond must be held against the work by a constant force, applied either by means of weight or a spring. I made many trials by this method, using a watchmaker's lathe and pressing up the work by a weight and string, which passed over a pulley. I used about 40 ounces, and drilled a hole 3/32 in diameter in flint glass at a speed of 900 revolutions per minute to a depth of one-eighth of an inch in eight minutes. I used soap and water as a lubricant, and the work was satisfactory. Since this was set up, I have been informed by Mr. Hicks of Hatton Garden that it is necessary to anneal glass rod by heating it up to the softening point and allowing it to cool very slowly under red-hot sand or asbestos before boring. If this be done, no trouble will be experienced. The annealing must be perfect.] § 39. For boring large holes through thick glass sheets, or, indeed, through anything where it is necessary to make sure that no accident can happen, or where great precision of position and form of hole is required, I find a boring tube mounted as shown in the picture (Fig. 36) is of great service. Brass or iron tube borers do perfectly well, and the end of the spindle may be provided once for all with a small tube chuck, or the tubes may be separately mounted as shown. A fairly high speed is desirable, and may be obtained either by foot, or, if power is available, is readily got by connecting to the speed cone of a lathe, which is presumably permanently belted to the motor. Fig. 36. After trying tubes armed with diamond dust, as will be presently explained, I find that emery and thin oil or turpentine, if liberally supplied below the glass, will do very nearly as well. The tube should be allowed to rise from the work every few seconds, so as to allow of fresh emery and oil being carried into the circular grooves. This is done by lifting the hinged upper bearing, the drill being lifted by a spiral spring between the pulley and the lower bearing shown at B. The glass may be conveniently supported on a few sheets of paper if flat, or held firm in position by wooden clamps if of any other shape. In any case it should be firmly held down and should be well supported. Any desired pressure upon the drill is obtained by weighting the hinged board A. § 40. The following method was shown to me by Mr. Wimshurst, but I have not had occasion to employ it myself. It is suitable for boring large holes through such glass as the plates of Mr. Wimshurst's Influence machines are usually made of. A diamond is mounted as the "pencil" of a compass, and with this a circle is drawn on the glass in the desired position. The other leg of the compass of course rests on a suitable washer. To the best of my recollection the further procedure was as follows. A piece of steel rod about one-eighth inch in diameter was ground off flat and mounted in a vice vertically, so as to cause its plane end to form a small horizontal anvil. The centre (approximately) of the diamond-cut circle of the glass was laid on this anvil so as to rest evenly upon it, and the upper surface (i.e. that containing the cut) was then struck smartly with a hammer, completely pulverising the glass above the anvil. The hole was gradually extended in a similar manner right up to the diamond cut, from which, of course, the glass broke away. A similar method has long been known to glaziers, differing from the preceding in that a series of diamond cuts are run across the circle parallel to two mutually perpendicular diameters. A smart tap on the back of the scored disc will generally cause the fragments to tumble out. I have never tried this myself, but I have seen it done. Large discs may easily be cut from sheet glass by drawing a circular diamond cut, and gradually breaking away the outer parts by the aid of additional cuts and a pair of pliers or "shanks" (see Fig. 44). § 41. Operations depending on Grinding: Ground-in Joints. The process will be perfectly understood by reference to a simple case. Suppose it is desired to grind the end of a tube into the neck of a bottle. If a stoppered bottle is available, the stopper must be taken out and measured as to its diameter at the top and bottom. Select a bit of tube as nearly as possible of the same diameter as the stopper at its thickest part. Draw down the glass in the blow-pipe flame rather by allowing it to sink than by pulling it out. After a few trials no difficulty will be experienced in making its taper nearly equal to that of the stopper, though there will in all probability be several ridges and inequalities. When this stage is reached anneal the work carefully and see that the glass is not too thin. Afterwards use emery and water, and grind the stopper into the bottle. There are six special directions to be note (1 )Turn the stopper through at least one revolution in each direction. (2) Lift it out often so as to give the fresh emery a chance of getting into the joint. (3) Rotate the bottle as well as the stopper in case there is any irregularity in the force brought to bear, which might cause one side of the neck to be more ground than another, or would cause the tube to set rather to one side or the other. (4) Use emery passing a 50 sieve, i.e. a sieve with fifty threads to the inch run (see § 144) to begin with, and when the stopper nearly fits, wash this thoroughly away, and finish with flour emery, previously washed to get rid of particles of excessive size; the process of washing will be fully discussed in the chapter on glass-grinding, which see. (5) Any degree of fineness of surface may be obtained by using graded emery, as will be explained, but, in general, it is unnecessary to attempt a finer surface than can be got with washed flour emery. A superficial and imperfect polish may be given by grinding for a short time with powdered pumice stone. (6) If the proper taper is not attained by blowing, or if ridges are left on the tapered part, the process may be both hastened and improved by giving the taper a preliminary filing with a three-cornered file and kerosene, just as one would proceed with iron or brass. A little filing will often save a good deal of grinding and make a better job. If a bottle without a tapered neck is to be employed, it is as well to do the preliminary grinding by means of a cone turned up from a bit of cast iron. This is put in the lathe and pushed into the mouth of the bottle, the latter being supported by the hands. Use about the same surface speed as would be employed for turning cast iron. In this case the emery is better used with kerosene. If a cylindrical bit of cast iron about an inch in diameter is turned down conically nearly to a point, it will save a good deal of trouble in making separate cones. If it gets ground into rings, and it becomes necessary to turn it up, use a diamond tool until the skin is thoroughly removed; the embedded emery merely grinds the edge off any ordinary steel tool. For diamond tools see § 55. § 42. Use of the Lathe in Glass-working. If it is necessary to remove a good deal of glass, time may be saved by actually turning the glass in a lathe. According to the direction given above for grinding a tube into the neck of a bottle, very little glass need be removed if the drawing down is well done, so that for this purpose turning is often unnecessary. If the taper of the stopper be small and it is permissible to use a thick tube, or if a solid stopper only has to be provided, or an old stopper quickly altered to a new form, turning is very useful. The glass may be "chucked" in any suitable manner, and run at a speed not exceeding 10 feet per minute. Prepare a three-cornered file by mercury-hardening and by grinding the end flat so as to form a cutting angle of about 80°, and use a moderate amount of kerosene lubrication, i.e. enough to keep the glass damp, but even this is not essential. Use the file as an ordinary brass turning tool, and press much more lightly than for metal turning. The glass will be found to scrape off quite pleasantly. By chucking glass tubes on wooden mandrells the ends may be nicely turned in this manner ready for accurate closing by glass plates. The process of grinding also is made much more rapid--at all events in the earlier stages--by chucking either the stopper or the bottle and holding the other member in the fingers, or in a wooden vice held in the hands. The finishing touches are best given by hand. I ought to say that I think a good deal of glass-grinding, as practised in laboratories, might be advantageously replaced by glass turning or filing and certainly will be by any one who will give these methods a trial. If one tube is to be ground into another, as in grinding a retort into a receiver, the latter must be drawn down from a larger piece, few beginners being able to widen a tube by the method explained with sufficient ease and certainty. The other operations are similar to the operations above described. § 43. Funnels often require to be ground to an angle of 60°. For this purpose it is well to keep a cast-iron cone, tapering from nothing up to four inches in diameter. This may be mounted on a lathe, and will be found of great use for grinding out the inside of funnels. Care must be taken to work the funnel backwards and forwards, or it will tend to grind so as to form rings, which interfere with filtering. A rough polish may be given on the lines explained in the next section. § 44. A rough polish may be easily given to a surface which has been finished by washed flour emery, in the following manner. Turn up a disc of soft wood on the lathe, and run it at the highest wood-turning speed. Rub into the periphery a paste of sifted powdered pumice stone and water. Any fairly smooth ground glass surface may be more or less polished by holding it for a moment against the revolving disc. Exact means of polishing will be described later on. Meanwhile this simple method will be found both quick and convenient, and is often quite sufficient where transparency, rather than figure, is required. I daresay a fine polish may be got on the same lines, using putty powder or washed rouge (not jewellers' rouge, which is too soft, but glass-polishers' rouge) to follow the pumice powder, but I have not required to try this. § 45. It is sometimes required to give to ground glass surfaces a temporary transparency. This is to be done by using a film of oil of the same refractive index as the glass. Cornu has employed a varnish consisting of a mixture of turpentine and oil of cloves, but the yellow-brown colour of the latter is often a disadvantage. It will be found that a mixture of nut oil and oil of bitter almonds, or of bromo-napthalene and acetone, can be made of only a faint yellow colour; and by exact adjustment of the proportions will have the same refractive index for any ray as crown glass (ordinary window glass). Procure a sample of the glass and smash it up to small fragments in an iron mortar. Sift out the fine dust and the larger pieces; bits about as large as small beads--say one-sixteenth inch every way--do very well. Boil the sifted glass with strong commercial hydrochloric acid to remove iron, wash with distilled water and a few drops of alcohol, dry on blotting paper in the sun or otherwise. Put the dry glass into a bottle or beaker, and begin by adding almond oil (or bromo-napthalene), then add nut oil (or acetone) till the glass practically disappears when examined by sodium light, or light of any other wave-length, as may be required. The adjustment of the mixture is a matter of great delicacy, one drop too much of either constituent, in, say, 50 cubic centimetres, makes all the difference. The final adjustment is best accomplished by having two mixtures of the oils, one just too rich in almond, the other in nut oil; by adding one or other of these, the required mixture is soon obtained. It is to be noted (1) That adjustment is only perfect for light of one wave-length. (2) That adjustment is only perfect at one temperature. On examining a bottle of rather larger fragments of glass immersed in an adjusted mixture by ordinary daylight, a peculiarly beautiful play of colours is seen. Of course, if it is only desired to make ground glass fairly transparent, these precautions are unnecessary, but it seemed better to dispose of the matter once for all in this connection. M. Cornu's object was to make a varnish which would prevent reflection from the back of a photographic plate on to the film. I have had occasion to require to do the same when using a scale made by cutting lines through a film of black varnish on a slip of glass. This succeeded perfectly by making the varnish out of Canada balsam stained with a black aniline dye. Mr. Russell, Government Astronomer of New South Wales, finds that the "halation" of star photographs can be prevented by pouring over the back of the plate a film of collodion suitably stained. § 46. Making Ground Glass. This is easily done by rubbing the surface of polished glass with a bit of cast iron and washed "flour of emery." Of course, if the fineness of grain of the surface is of importance, appropriate sizes of emery must be employed. The iron may be replaced by a bit of glass cut with transverse grooves to allow the emery to distribute itself, or even by a bit of glass without such grooves, provided it does not measure more than one or two inches each way. If great speed is an object rather than the fineness of the surface, use a bit of lead and coarse emery, say any that will pass a sieve with fifty threads to the inch. It may perhaps be mentioned here that it is a pity to throw away emery which has been used between glass and glass. In the chapter dealing with fine optical work the use of emery of various grades of fineness will be treated, and the finer grades can only be obtained (to my knowledge) from emery which has been crushed in the process of glass or metal grinding, especially the former. A large jam-pot covered with a cardboard lid does well as a receptacle of washings. § 47. Glass-cutting. This is an art about which more can be learned in five minutes by watching it well practised than by pages of written description. My advice to any one about to commence the practice of the art would be to make friends with a glazier and see it done. What follows is therefore on the supposition that this advice has been followed. After some experience of cutters made of especially hardened steel, I believe better work can generally be got out of a diamond, provided the cost is not an objection. It is economy to pay a good price for a good diamond. As is well known, the natural angle of the crystal makes the best point, and a person buying a diamond should examine the stone by the help of a lens, so as to see that this condition is fulfilled. The natural angle is generally, if not always, bounded by curved edges, which have a totally different appearance from the sharp edges of a "splinter." When a purchase is to be made, it is as well for the student to take a bit of glass and a foot-rule with him, and to test the diamond before it is taken away. When a good diamond has been procured, begin by taking cuts on bits of clean window glass until the proper angle at which to hold the tool is ascertained. Never try to cut over a scratch, if you value your diamond, and never press hard on the glass; a good cut is accompanied by an unmistakable ringing sound quite different from the sound made when the diamond is only scratching. Perhaps the most important advice that can be given is, Never lend the diamond to anybody--under any circumstances. The free use of a diamond is an art which the physicist will do well to acquire, for quite a variety of apparatus may be made out of glass strips, and the accuracy with which the glass breaks along a good cut reduces such an operation as glass-box-making to a question of accurate drawing. § 48. Cementing. One of the matters which is generally confused by too great a profusion of treatment is the art of cementing glass to other substances. The following methods will be found to work, subject to two conditions: (1) The glass must be clean; (2) it must be hot enough to melt the cement. For ordinary mending purposes when the glass does not require to be placed in water (especially if hot) nothing is better than that kind of glue which is generally called "diamond cement." This may be easily made by dissolving the best procurable isinglass in a mixture of 20 per cent water and 80 per cent glacial acetic acid--the exact proportions are not of consequence. First, the isinglass is to be tightly packed into a bottle with a wide neck, then add the water, and let the isinglass soak it up. Afterwards pour in the acetic acid, and keep the mixture near 100°C. for an hour or two on the water bath--or rather in it. The total volume of acetic acid and water should not be more than about half of the volume of isinglass when the latter is pressed into the bottle as tightly as possible. The proper consistency of the cement may be ascertained by lifting a drop out of the bottle and allowing it to cool on a sheet of glass. In ten minutes it ought not to be more than slightly sticky, and the mass in the bottle, after standing a few hours cold, should not be sticky at all, and should yield, jelly-like, to the pressure of the finger to only a slight degree. If the glue is too weak, more isinglass may be added (without any preliminary soaking). A person making the mixture for the first time almost always gets it too weak. It is difficult to give exact proportions by weight, as isinglass and gelatine (which may replace it) differ greatly in quality. This cement is applied like glue, and will cement nearly anything as well as glass. Of course, as much cement as possible must be squeezed out of any joint where it is employed. The addition of gums, as recommended in some books, is unnecessary. Ordinary glue will serve perfectly for cementing glass to wood. "Chipped glass" ware is, I understand, made by painting clean glass with glue. As the glue dries and breaks by contraction, it chips off the surface of the glass. I have never seen this done. In nearly all cases where alcohol is not to be employed very strong joints may be made by shellac. Orange shellac is stronger than the "bleached" variety. A sine qua non is that the glass be hot enough to melt the shellac. The best way is to heat the glass surfaces and rub on the shellac from a bit of flake; the glass should not be so hot as to discolour the shellac appreciably, or its valuable properties will be partly destroyed. Both glass surfaces being thus prepared, and the shellac being quite fluid on both, they may be brought together and clamped tightly together till cool. Shellac that has been overheated, or dissolved in alcohol, or bleached, is of little use as compared with the pale orange flaky product. Dark flakes have probably been overheated during the preliminary refining. For many purposes a cement is required capable of resisting carbon bisulphide. This is easily made by adding a little treacle (say 20 per cent) to ordinary glue. Since the mixture of glue and treacle does not keep, i.e. it cannot be satisfactorily melted up again after once it has set, no more should be made up than will be wanted at the time. If the glue be thick, glass boxes for carbon disulphide may be easily put together, even though the edges of the glass strips are not quite smooth, for, unlike most cements, this mixture remains tough, and is fairly strong in itself. I have found by experiment that most fixed and, to a less degree, essential oils have little or no solvent action on shellac, and I suspect that the same remark applies to the treacle-glue mixture, but I have not tried. Turpenes act on shellac slightly, but mineral oils apparently not at all. The tests on which these statements are based were continued for about two years, during which time kerosene and mineral oils had no observable effect on shellac--fastened galvanometer mirrors. § 49. Fusing Electrodes into Glass. This art has greatly improved since the introduction of the incandescent lamp; however, up to the present, platinum seems to remain the only substance capable of giving a certainly air-tight result. I have not tried the aluminium-alumina method. Many years ago it was the fashion to surround the platinum wire with a drop of white enamel glass in order to cause better adhesion between it and the ordinary glass. [Footnote: Hittorf and Geissler (Pogg. Ann. 1864, § 35; English translation, Phys. Soc. London, p. 138) found that it was impossible to make air-tight joints between platinum and hard potash glass, but that soft lead glass could be used with success as a cement.] However, in the case of flint glass, if one may judge from incandescent lamps, this is not essential--a fact which entirely coincides with my own experience. On the other hand, when sealing electrodes into German glass I have often used a drop of enamel with perfect results, though this is not always done in Germany. In all cases, however, in which electrodes have to be sealed in--especially when they are liable to heat--I recommend flint glass, and in this have the support of Mr. Rain (The Incandescent Lamp and its Manufacture, p. 131). The exact details for the preparation of eudiometer tubes are given by Faraday (Chemical Manipulation, § 1200). In view of what has preceded, however, I will content myself with the following notes. Make the hole through which the wire is to protrude only slightly larger than the wire itself, and be sure that the latter is clean. Allow the glass to cool sufficiently not to stick to the wire when the latter is pushed in. Be sure that, on heating, the glass does not get reduced, and that it flows up to the wire all round; pull and push the wire a little with a pair of pincers, to ensure this. It is not a bad plan to get the glass exceedingly fluid round the wire--even if the lump has to be blown out a little afterwards--as it cools. The seal should finally be well annealed in asbestos, but first by gradually moving it into the hot air in front of the flame. It was observed by Professor J. J. Thomson and the author some years ago (Proc. Roy. Soc. 40. 331. 1886) that when very violent discharges are taken through lightly sealed-in electrodes in lead-glass tubes--say from a large battery of Leyden jars--gas appears to be carried into the tube over and above that naturally given off by the platinum, and this without there being any apparent want of perfection in the seal. This observation has since been confirmed by others. Consequently in experiments on violent discharges in vacuo where certainty is required as to the exclusion of air, the seals should be protected by a guard tube or cap containing mercury; this must, of course, be put in hot and clean, on hot and clean glass, and in special cases should be boiled in situ. A well-known German physicist (Warburg, I think) recommends putting the seals under water, but I cannot think that this is a good plan, for if air can get in, why not water? which has its surface tension in its favour. The same reasoning prevents my recommending a layer of sulphuric acid above the mercury-a method used for securing air-tightness in "mercury joints" by Mr. Gimingham, Proc. R. S. 1874. Further protection may be attained for many purposes by coating the platinum wire with a sheath of glass, say half an inch long, fused to the platinum wire to a depth of one-twentieth of an inch all round. In some cases the electrodes must be expected to get very hot, for instance, when it is desired to platinise mirrors by the device of Professor Wright of Yale. In this and similar cases I have met with great success by using "barometer" tubes of about one-twelfth of an inch bore, and with walls, say, one-tenth of an inch thick. [Footnote: "Barometer" tube is merely very thick-walled glass tubing, and makes particularly bad barometers, which are sold as weather glasses.] This tube is drawn down to a long point--say an inch long by one-eighth of an inch external diameter, and the wire is fused in for a length, say, of three-quarters of an inch, but only in the narrow drawn--down part of the tube. At different times I have tried four such seals, and though the electrodes were red hot for hours, I have never had an accident--of course they were well annealed. Fig. 37. For directions as to the making of high vacuum tubes, see the section dealing with that matter. § 50. As economy of platinum is often of importance, the following little art will save money and trouble. Platinum is easily caused to join most firmly to copper--with which, I presume, it alloys--by the following method. Hold the platinum wire against the copper wire, end to end, at the tip of the reducing flame of a typical blowpipe--or anywhere--preferably in the "reducing" part of the oxygas flame; in a moment the metals will fuse together at the point of contact, when they may be withdrawn. Such a joint is very strong and wholly satisfactory, much better than a soldered joint. If the work is not carried out successfully so that a considerable drop of copper-platinum alloy accumulates, cut it off and start again. The essence of success is speed, so that the copper does not get "burned." If any considerable quantity of alloy is formed it dissolves the copper, and weakens it, so that we have first the platinum wire, then a bead of alloy, and then a copper wire fused into the bead, but so thin just outside the latter that the joint has no mechanical strength. § 51. The Art of making Air-light Joints. Lamp-manufacturers and others have long since learned that when glass is in question not only are fused joints made as easily as others, but that they afford the only reliable form of joint. An experimenter who uses flint glass, has a little experience, an oxygas blow-pipe and a blowing apparatus, will prefer to make his joints in this way, simply from the ease with which it may be done. When it comes to making a tight joint between glass and other substances the problem is by no means so easy. Thus Mr. Griffiths (Phil. Trans. 1893, p. 380) failed to make air-tight joints by cementing glass into steel tubes, using hard shellac, and the tubes fitting closely. These joints were satisfactory at first, but did not last; the length of the joint is not stated. The difficulty was finally got over by soldering very narrow platinum tubes into the steel, and fusing the former into the glass. Mr. Griffiths has since used an alloy with success as a cement, but I cannot discover what it is made from. Many years ago Professor Hittorf prepared good high vacuum tubes by plugging the ends of glass tubes with sealing wax merely, though in all cases the spaces to be filled with wax were long and narrow (Hittorf, Pogg. Ann. 1869, § 5, English translation, Phys. Soc. p. 113). Again, Regnault habitually used brass ferules, and cemented glass into them by means of his mastic, which can still be procured at a low rate from his instrument-makers (Golan, Paris). Lenard also, in his investigations on Cathode Rays (Wied. Ann, vol. li. p. 224), made use of sealing wax covered with marine glue. Surely in face of these facts we must admit that cement joints can be made with fair success. I do not know the composition of M. Regnault's mastic, but Faraday (Manipulations, § 1123) gives the following receipt for a cement for joining ferules to retorts, etc: Resin 5 parts. Beeswax 1 part. Red ochre or Venetian red, finely powdered and sifted 1 part. I believe this to be substantially the same as Regnault's mastic, though I have never analysed the latter. For chemical work the possibility of evolution of gas from such a cement must be taken into account, and I should certainly not trust it for this reason in vacuum tube work, where the purity of the confined gas could come in question. Otherwise it is an excellent cement, and does not in my experience tend to crack away from glass to the same extent as paraffin or pure shellac. This cracking away from glass, by the way, is probably an effect of difference in rate of expansion between the glass and cement which probably always exists, and, if the cement be not sufficiently viscous, must, beyond certain temperature limits, either produce cracks or cause separation. Professor Wright of Yale has used a hard mineral pitch as a cement in vacuum work with success. My attention has been directed to a fusible metal cement containing mercury, and made according to the following receipt, given by Mr. S. G. Rawson, Journal of the Society of Chemical Industry, vol. ix. (1890), P. 150:- Bismuth 40 per cent Lead 25 per cent Tin 10 per cent Cadmium 10 per cent Mercury 15 per cent This is practically one form of Rose's fusible metal with 15 per cent mercury added. It takes nearly an hour to set completely, and the apparatus must be clean and warm before it is applied. As the result of several trials by myself and friends, I am afraid I must dissent from the claim of the author that such a cement will make a really air-tight joint between glass tubes. Indeed, the appearance of the surface as viewed through the glass is not such as to give any confidence, no matter what care may have been exercised in performing all the operations and cleaning the glass; besides which the cement is rigid when cold, and the expansion difficulty comes in. On the other hand, if extreme air-tightness is not an object, the cement is strong and easily applied, and has many uses. I have an idea that if the joints were covered with a layer of soft wax, the result would be satisfactory in so far as air-tightness is concerned. This anticipation has since been verified. In many cases one can resort to the device already mentioned of enclosing a rubber or tape-wrapped joint between two tubes in a bath of mercury, but in this case the glass must be clean and hot and the mercury also warm, dry, and pure when the joint is put together, otherwise an appreciable air film is left against the glass, and this may creep into the joint. Perhaps the easiest way of making such a joint is to use an outer tube of thin clean glass, and bore a narrow hole into it from one side to admit the mercury; if the mercury is to be heated in vacuo, it is better to seal on a side joint. It is always better, if possible, to boil the mercury in situ, which involves making the wrapping of asbestos, but, after all, we come back to the position I began by taking up, viz. that the easiest and most reliable method is by fusion of the glass--all the rest are unsuitable for work of real precision. I should be ungrateful, however, were I not to devote a few lines to the great convenience and merit of so-called "centering cement." This substance has two or three very valuable properties. It is very tough and strong in itself, and it remains plastic on cooling for some time before it really sets. If for any reason a small tube has to be cemented into a larger one, which is a good deal larger, so that an appreciable mass of cement is necessary, and particularly if the joint requires to have great mechanical strength, this cement is invaluable. I have even used a plug of it instead of a cork for making the joint between a gas delivery tube and a calcium chloride tower. (Why are these affairs made with such abominable tubulures?) The joint in question has never allowed the tube to sag though it projects horizontally to a distance of 6 inches, and has had to withstand nearly two years of Sydney temperature. The cement consists of a mixture of shellac and 10 per cent of oil of cassia. The shellac is first melted in an iron ladle, and the oil of cassia quickly added and stirred in, to an extent of about 10 per cent, but the exact proportions are not of importance. Great care must be taken not to overheat the shellac. APPENDIX TO CHAPTER I ON THE PREPARATION OF VACUUM TUBES FOR THE PRODUCTION OF PROFESSOR ROENTGEN'S RADIATION [Footnote: Written in May 1896.] WHEN Professor Roentgen's discovery was first announced at the end of 1895 much difficulty was experienced in obtaining radiation of the requisite intensity for the repetition of his experiments. The following notes on the production of vacuum tubes of the required quality may therefore be of use to those who desire to prepare their own apparatus. It appears that flint glass is much more opaque to Roentgen's radiation than soda glass, and consequently the vacuum tubes require to be prepared from the latter material. Fig. 39. A form of vacuum tube which has proved very successful in the author's hands is sketched in Fig. 38. It is most easily constructed as follows. A bit of tubing about 2 centimetres diameter, 15 centimetres long, and 1.5 millimetre wall thickness, is drawn down to a point. The larger bulb, about 5 centimetres in diameter, is blown at one end of this tube. The thinner the bulb the better, provided that it does not collapse under atmospheric pressure. A very good idea of a proper thickness may be obtained from the statement that about 4 centimetres length of the tubing should be blown out to form the bulb. This would give a bulb of about the thickness of an ordinary fractionating bulb. Before going any further it is as well to test the bulb by tapping on the table and by exhausting it by means of an ordinary water-velocity pump. The side tube is next prepared out of narrower tubing, and is provided with a smaller bulb, a blowing-out tube, and a terminal, to be made as will be described. This side tube is next fused on to the main tube, special care being taken about the annealing, and the cathode terminal is then sealed into the main tube. After using clean glass it is in general only necessary to rinse the tube out with clean alcohol, after which it may be dried and exhausted. The success of the operation will depend primarily on the attention given to the preparation and sealing-in of the electrode facing the large bulb. Preparation of Terminals. Some platinum wire of about No. 26 B.W.G--the exact size is unimportant--must be provided, also some sheet aluminium about 1 millimetre thick, some white enamel cement glass, and a "cane" of flint-glass tube of a few millimetres bore. The electrodes are prepared by cutting discs of aluminium of from 1 to 1.5 centimetres diameter. The discs of aluminium are bored in the centre, so as to admit the "stems" which are made of aluminium wire of about 1 millimetre diameter. The stems are then riveted into the discs. The "stems" are about I centimetre long, and are drilled to a depth of about 3 millimetres, the drill used being about double the diameter of the platinum wire to be used for making the connections. The faces of the electrodes--i.e. the free surfaces of the aluminium discs--are then hammered flat and brought to a burnished surface by being placed on a bit of highly polished steel and struck by a "set" provided with a hole to allow of the "stem" escaping damage. The operation will be obvious after a reference to Figs. 39 and 40; it is referred to again on page 96. The platinum wires may be most conveniently attached by melting one end of the piece of platinum wire in the oxygas blow-pipe till it forms a bead just large enough to pass into the hole drilled up the stem of the electrode. The junction between the stein and the platinum wire is then made permanent by squeezing the aluminium down upon the platinum wire with the help of a pair of pliers. It is also possible to fuse the aluminium round the platinum, but as I have had several breakages of such joints, I prefer the mechanical connection described. Fig. 39. Sets for striking aluminium electrodes Fig. 40. i. Aluminium electrode. ii. Aluminium electrode connected to platinum wire. iii. Aluminium electrode connected to platinum wire and protected by glass. iv. Detail of fastening platinum wire. The stem and platinum wire may now be protected by covering them with a little flint glass. For this purpose the flint-glass tube is pulled down till it will just slip over the stem and wire, and is cut off so as to leave about half a centimetre of platinum wire projecting. The flint-glass tube is then fused down upon the platinum wire, care being taken to avoid the presence of air bubbles. At the close of the operation a single drop of white enamel glass is fused round the platinum wire at a high temperature, so as to make a good joint with the protecting flint-glass tube. The negative electrode being nearly as large as the main tube, it must be introduced before the latter is drawn down for sealing. After drawing down the main tube in the usual manner, taking care not to make it less than a millimetre in wall-thickness, it is cut off so as to leave a hole not quite big enough for the enamel drop to pass through. By heating and opening, the aperture is got just large enough to allow the enamel drop to pass into it, and when this is the case the joint is sealed, pulled, and blown out until the electrode occupies the right position--viz. in the centre of the tube and with its face normal to the axis of the tube. The glass walls near the negative electrode must not be less than a millimetre thick, and may be rather more with advantage, the glass must be even, and the joint between the flint glass and the soda glass, or between the wire and the soda glass, must be wholly through the enamel. The "seal" must be well annealed. It will be found that the sealing-in process is much easier when the stem of the electrode is short and when the glass coating is not too heavy. Half a millimetre of glass thickness round the stein is quite sufficient. The diagram, of the tube shows that the main tube has been expanded round the edges of the cathode. This is to reduce the heating consequent on the projection of cathode rays from the edges of the disc against the glass tube. The anode is inserted into its bulb in a quite similar manner. If desired it may be made considerably smaller, and does not need the careful adjustment requisite in sealing-in the cathode, nor does the glass near the entry wire require to be so thick. More intense effects are often got by making the cathode slightly concave, but in this case the risk of melting the thin glass is considerably increased. No doubt, Bohemian glass might be used throughout instead of soft soda glass, and this would not melt so easily; the difficulties of manipulating the glass are, however, more pronounced. It will be shown directly that the best Roentgen effects are got with a high vacuum, and it is for this reason that the glass near the cathode seal requires to be strong. The potential right up to the cathode is strongly positive inside the tube, and this causes the glass to be exposed to a strong electric stress in the neighbourhood of the seal. Although the glass-blowing involved in the making of a so-called focus tube is rather more difficult than in the case just described, there is no reason why such a difficulty should not be overcome; I will therefore explain how a focus tube may be made. Fig. 41. A bulb about 3 inches in diameter is blown from a bit of tube of a little more than 1 inch diameter. Unless the walls of the tube are about one-eighth of an inch in thickness, this will involve a preliminary thickening up of the glass. This is not difficult if care be taken to avoid making the glass too hot. The larger gas jet described in connection with the soda-glass-blowing table must be employed. In blowing a bulb of this size it must not be forgotten that draughts exercise a very injurious influence by causing the glass to cool unequally; this leads to bulbs of irregular shape. In the method of construction shown in Fig. 41, the anode is put in first. This anode simply consists of a square bit of platinum or platinum-iridium foil, measuring about 0.75 inch by 1 inch, and riveted on to a bent aluminium wire stem. As soon as the anode is fused in, and while the glass is still hot, the side tube is put on. The whole of the anode end is then carefully annealed. When the annealing is finished the side tube is bent as shown to serve as a handle when the time comes to mount the cathode. Before placing the cathode in position, and while the main tube is still wide open, the anode is adjusted by means of a tool thrust in through this open end. This is necessary in view of the fact that the platinum foil is occasionally bent during the operation of forcing the anode into the bulb. The cathode is a portion of a spherical surface of polished aluminium, a mode of preparing which will be given directly. The cathode having been placed inside the bulb, the wide glass tube is carefully drawn down and cut off at such a point that when the cathode is in position its centre of curvature will lie slightly in front of the anode plate. For instance, if the radius of curvature of the cathode be 1.5 inches, the centre of curvature may lie something like an eighth of an inch or less in front of the anode. The cathode as shown in Fig. 41 is rather smaller than is advantageous. To make it much larger than is shown, however, the opening into the bulb would require to be considerably widened, and though this is not really a difficult operation, still it requires more practice than my readers are likely to have had. The difficulty is not so much in widening out the entry as in closing it down again neatly. Now as to making the anode. A disc of aluminium is cut from a sheet which must not be too thick--one twenty-fifth of an inch is quite thick enough. This disc is bored at the centre to allow of the stem being riveted in position. The disc is then annealed in the Bunsen flame and the stem riveted on. The curvature is best got by striking between steel dies (see Figs. 39 and 40). Two bits of tool steel are softened and turned on the lathe, one convex and the other concave. The concave die has a small hole drilled up the centre to admit the stem. The desired radius of curvature is easily attained by cutting out templates from sheet zinc and using them to gauge the turning. The two dies are slightly ground together on the lathe with emery and oil and are then polished, or rather the convex die is polished--the other one does not matter. The polishing is most easily done by using graded emery and oil and polishing with a rag. The method of grading emery will be described in the chapter on glass-grinding. The aluminium disc is now struck between the dies by means of a hammer. If the radius of curvature is anything more than one inch and the disc not more than one inch in diameter the cathode can be struck at once from the flat as described. For very deep curves no doubt it will be better to make an intermediate pair of dies and to re-anneal the aluminium after the first striking. When the tube is successfully prepared so far as the glassblowing goes it may be rinsed with strong pure alcohol both inside and out, and dried. The straight part of the side tube is then constricted ready for fusing off and the whole affair is placed on the vacuum pump. In spite of the great improvements made during recent years in the construction of so-called Geissler vacuum pumps--i.e. pumps in which a Torricellian vacuum is continually reproduced--I am of opinion that Sprengel pumps are, on the whole, more convenient for exhausting Crooke's tubes. A full discussion of the subject of vacuum pumps will be found in a work by Mr. G. S. Ram (The Incandescent Lamp and its Manufacture), published by the Electrician Publishing Company, and it is not my intention to deal with the matter here; the simplest kind of Sprengel pump will be found quite adequate for our purpose, provided that it is well made. Fig. 42 is intended to represent a modification of a pump based on the model manufactured by Hicks of Hatton Garden, and arranged to suit the amateur glass-blower. The only point of importance is the construction of the head of the fall tube, of which a separate and enlarged diagram is given. The fall tubes may have an internal diameter up to 2 mm. (two millimetres) and an effective length of 120 cm. Free use is made of rubber tube connections in the part of the pump exposed to the passage of mercury. The rubber employed should be black and of the highest quality, having the walls strengthened by a layer of canvas. If such tube cannot be easily obtained, a very good substitute may be made by placing a bit of ordinary black tube inside another and rather larger bit and binding the outer tube with tape or ribbon. In any case the tubing which comes in contact with the mercury should be boiled in strong caustic potash or soda solution for at least ten minutes to get rid of free sulphur, which fouls the mercury directly it comes in contact with it. The tubing is well washed, rinsed with alcohol, and carefully dried. Fig. 42. The diagram represents what is practically a system of three Sprengel pumps, though they are all fed from the same mercury reservoir and run down into the same mercury receiver. It is much easier to make three pumps, each with separate pinch cocks to regulate the mercury supply, than it is to make three jets, each delivering exactly the proper stream of mercury to three fall tubes. Sprengel pumps only work at their highest efficiency when the mercury supply is carefully regulated to suit the peculiarities of each fall tube, and this is quite easily done in the model figured. Since on starting the pump the rubber connections have to stand a considerable pressure, the ends of the tubes must be somewhat corrugated to enable the rubber to be firmly wired on to them. The best binding wire is the purest Swedish iron wire, previously annealed in a Bunsen gas flame. The wire must never be twisted down on the bare rubber, but must always be separated from it by a tape binding. By taking this precaution the wire maybe twisted very much more tightly than is otherwise possible without cutting the rubber. The only difficulty in making such a pump as is described lies in the bending of the heads of the fall tubes. This bending must be done with perfect regularity and neatness, otherwise the drops of mercury will not break regularly, or will break just inside the top of the fall tube, and so obstruct its entrance that at high vacua no air can get into the tube at all. The connections at the head of the fall tubes must also be well put on and the joints blown out so that the mercury in dropping over the head is not interfered with by the upper surface of the tube. However, a glance at the enlarged diagram will show what is to be aimed at better than any amount of description. In preparing the fall tubes it is generally necessary to join at least two "canes" together. The joint must be arranged to occur either in the tube leading the mercury to the head of the fall, or in that part of the fall tube which remains full of mercury when the highest vacuum is attained. On no account must the joint be made at the fall itself (at least not by an amateur), nor in that part of the fall tube where the mercury falls freely, particularly at its lower end, where the drops fall on the head of the column of mercury. When a high vacuum is attained the efficacy of the pump depends chiefly on the way in which the drops fall on the head of the column. If the fall is too long the drops are apt to break up and allow the small bubble of air to escape up the tube, also any irregularity or dirt in the tube at this point makes it more easy for the bubbles of air to escape to the surface of the mercury. Any pump in which the supply of mercury to the fall tube can be regulated nicely will pump well until the lowest available pressures are being attained; a good pump will then continue to hold the air bubbles, while a bad one will allow them to slip back [Footnote: For special methods of avoiding this difficulty see Mr. Ram's book.] ... Though three fall tubes are recommended, it must not be supposed that the pump will produce a Crooke's vacuum three times more rapidly than one fall tube. Until the mercury commences to hammer in the pump the three tubes will pump approximately three times faster than one tube, but as soon as the major portion of the air collected begins to come from the layer condensed on the glass surface of the tube to be exhausted and from the electrodes, the rate at which exhaustion will go on no longer depends entirely on the pump. In order that bubbles of air may not slip back up the fall tube it is generally desirable to allow the mercury to fall pretty briskly, and in this case the capacity of the pump to take air is generally far in excess of the air supply. One advantage of having more than one fall tube is that it often happens that a fall tube gets soiled during the process of exhaustion and no longer works up to its best performance. Out of three fall tubes, however, one is pretty sure to be working well, and as soon as the mercury begins to hammer in the tubes the supply may be shut off from the two falls which are working least satisfactorily. Thus we are enabled to pump rapidly till a high degree of exhaustion is attained, having practically three pumps instead of one, whereas when the final stages are reached, and three pumps are only a drawback in that they increase the mercury flow, the apparatus is capable of instant modification to meet the new conditions. The thistle funnels at the head of the fall tubes are made simply by blowing bulbs and then blowing the heads of the bulbs into wider ones, and finally blowing the heads of the wider bulbs off by vigorous blowing. The stoppers are ground in on the lathe before the tubes are attached to the fall tubes. The stoppers require to be at least half an inch long where they fit the necks, and must be really well ground in. The stoppers must first be turned up nicely and the necks ground out by a copper or iron cone and emery. The stoppers are rotated on a lathe at quite a slow speed, say 30 or 40 feet per minute, and the necks are held against them, as described in the section dealing with this art. The stoppers must in this case be finished with "two seconds" emery, and lastly with pumice dust and water (see chapter on glass-grinding). Unless the stoppers fit exceedingly well trouble will arise from the mercury (which is poured into the thistle heads to form a seal) being forced downwards into the pump by atmospheric pressure. The joints between the three fall tubes and the single exhaust main are easily made when the tubes are finally mounted, the hooked nozzle of the oxygas blow-pipe being expressly made for such work. It is, on the whole, advisable to make the pump of flint glass, or at all events the air-trap tube and the fall tubes. A brush flame from the larger gas tube of the single blowpipe table is most suitable for the work of bending the tubes. The jointing of the long, narrow bore fall tubes is best accomplished by the oxygas flame, for in this way the minimum of irregularity is produced; the blowing tubes will of course be required for the job, and the narrow tubes must be well cleaned to begin with. The air trap is an important though simple part of the pump. Its shoulder or fall should stand rather higher than the shoulders of the fall tubes, so that the mercury may run in a thin stream through a good Torricellian vacuum before it passes down to the fall tubes. This is easily attained by regulating the main mercury supply at the pinch cock situated between the tube from the upper reservoir and the air-trap tube, the other cocks being almost wide open. It might be thought that the mercury would tend to pick up air in passing through the rubber connections to the fall tubes, but I have not found this to be the case in practice. There is, of course, no difficulty in eliminating the rubber connections between the fall tubes and the mercury supply from the air trap, but it impresses a greater rigidity on the structure and, as I say, is not in general necessary. It must not be forgotten that the mercury always exercises considerable pressure on the rubber joints, and so there is little tendency for gas to come out of the rubber. The thistle funnels at the head of the fall tubes provide a simple and excellent means of cleaning the fall tubes. For this purpose some "pure" sulphuric acid which has been boiled with pure ammonium sulphate is placed in each thistle funnel, and when the fall tube is dirty the connection to the mercury supply is cut off at the pinch cock so as to leave the tube between this entry and the head of the fall tube quite full of mercury, and the sulphuric acid is allowed to run down the fall tube by raising the stopper. The fall tube should be allowed to stand full of acid for an hour or so, after which it will be found to be fairly clean. Of course the mercury reservoir thus obtains a layer of acid above the mercury, and as it is better not to run the risk of any acid getting into the pump except in the fall tubes, the reservoir is best emptied from the bottom, by a syphon, if a suitable vessel cannot be procured, so that clean mercury only is withdrawn. The phosphorus pentoxide tube is best made as shown simply from a bit of wide tube, with two side connections fused to the rest of the pump. It is no more trouble to cut the tube and fuse it up again when the drying material is renewed than to adjust the drying tube to two fixed stoppers, which is the alternative. The practice here recommended is rendered possible only by the oxygas blow-pipe with hooked nozzle. The connection between the pump and tube to be exhausted is made simply by a short bit of rubber tube immersed in mercury. The phosphorus pentoxide should be pure, or rather free from phosphorus and lower oxides; unless this be the case, the vapour arising from it is apt to soil the mercury in the pump. The phosphorus pentoxide is purified by distilling with oxygen over red-hot platinum black; if this cannot be done, the pentoxide should at least be strongly heated in a tube, in a current of dry air or oxygen, before it is placed in the drying tube. The mercury used for the pump must be scrupulously clean. It does not, however, require to have been distilled in vacuo. It is sufficient to purify it by allowing it to fall in a fine spray into a large or rather tall jar of 25 per cent nitric acid and 75 per cent water. The mercury is then to be washed and dried by heating to, say, 110° C. in a porcelain dish. Exhausting a Roentgen Tube. With a pump such as has been described there is seldom any advantage in fusing an extra connection to the vacuum tube so as to allow of a preliminary exhaustion by means of a water pump. About half an hour's pumping may possibly be saved by making use of a water pump. The tube to be exhausted is washed and dried by careful heating over a Bunsen burner and by the passage of a current of air. The exhausting tube is then drawn down preparatory to sealing off, and the apparatus placed upon the pump. It is best held in position by a wooden clamp supported by a long retort stand. Exhaustion may proceed till the mercury in the fall tubes commences to hammer. At this point the tube must be carefully heated by a Bunsen flame, the temperature being brought up to, say, 400° C. The heating may be continued intermittently till little or no effect due to the heating is discernible at the pump. When this stage is reached, or even before, the electrodes may be connected up to the coil and a discharge sent through the tube. Care must be taken to stop the discharge as soon as a purple glow begins to appear, because when this happens, the resistance of the tube is very low, the electrodes get very hot, and may easily get damaged by a powerful discharge, and the platinum of the anode (if a focus tube is in question) begins to be distilled on to the glass. The heating and sparking are to be continued till the resistance of the tube sharply increases. This is tested by always having a spark gap, conveniently formed by the coil terminals, in parallel with the tube. If the terminals are points, it is convenient to set them at about one quarter of an inch distance apart. As soon as sparks begin to pass between the terminals of the spark gap it becomes necessary to watch the process of exhaustion very carefully. In the first place, stop the pump, but let the coil run, and note whether the sparks continue to flow over the terminals. If the glass and electrodes are getting gas free, the discharge will continue to pass by the spark gap, but if gas is still being freely given off, then in perhaps three minutes the discharge will return to the tube, and pumping must be recommenced. The Roentgen effect only begins to appear when the tube has got to so high a state of exhaustion that the resistance increases rapidly. By pumping and sparking, the resistance of the tube may be gradually raised till the spark would rather jump over 2 inches of air than go through the tube. When this state is attained the Roentgen effect as tested by a screen of calcium tungstate should be very brilliant. No conclusion as to the equivalent resistance of the tube can be arrived at so long as the discharge is kept going continually. When the spark would rather go over an inch of air in the spark gap than through the tube the pumping and sparking may be interrupted and the tube allowed to rest for, say, five minutes. It will generally be found that the equivalent resistance of the tube will be largely increased by this period of quiescence. It may even be found that the spark will now prefer to pass an air gap 3 inches long. In any case the sparking should now be continued, the pump being at rest, and the variations of tube resistance watched by adjusting the spark gap. If the resistance falls below an equivalent of 2 inches of air in the gap the pump must be brought into action again and continued until the resistance as thus estimated remains fairly constant for, say, ten minutes. When this occurs the narrow neck of the exhaust tube may be strongly heated till the blow-pipe flame begins to show traces of sodium light. The flame must then be withdrawn and the discharge again tested. This is necessary because it occasionally happens that gas is given off during the heating of the neck to the neighbourhood of its fusion temperature. If all is right the neck may now be fused entirely off and the tube is finished. Tubes of the focus pattern with large platinum anodes are in general (in my experience) much more difficult to exhaust than tubes of the kind first described. This is possibly to be attributed mainly to the gas given off by the platinum, but is also, no doubt, due to the tubes being much larger and exposing a larger glass surface. The type of tube described first generally takes about two hours to exhaust by a pump made as explained, while a "focus" tube has taken as long as nine hours, eight of which have been consumed after the tube was exhausted to the hammering point. The pressure at which the maximum heating of the anode by the cathode rays occurs is a good deal higher than that at which the maximum Roentgen effect is produced. There is little doubt that the Roentgen radiation changes in nature to some extent as the vacuum improves either as a primary or secondary effect. It is therefore of some importance to test the tube for the purpose for which it is to be used during the actual exhaustion. It has been stated, for instance, that the relative penetrability of bone and flesh to Roentgen radiation attains a maximum difference at a certain pressure; this is very likely the case. Whether this effect is a direct function of the density of the gas in the tube, or whether it is dependent on the voltage or time integral of the current during the discharge, are questions which still await a solution. The preparation of calcium tungstate for fluorescent screens is very simple. Commercial sodium tungstate is fused with dried calcium chloride in the proportion of three parts of the former to two parts of the latter, both constituents being in fine powder and well mixed together. The fusion is conducted in a Fletcher's crucible furnace in a clay crucible. The temperature is raised as rapidly as possible to the highest point which the furnace will attain--i.e. a pure white heat. At this temperature the mixture of salts becomes partly fluid, or at least pasty, and the temperature may be kept at its highest point for, say, a quarter of an hour. At the end of this time the mass is poured and scraped on to a brick, and when cold is broken up and boiled with a large excess of water to dissolve out all soluble matter. The insoluble part, which consists of a gray shining powder, is washed several times with hot water, and is finally dried on filter paper in a water oven. In order to prepare a screen the powder is ground slightly with very dilute shellac varnish, and is then floated over a glass plate so as to get an even covering. Unless the covering be very even the screen is useless, and no pains should be spared to secure evenness. It is not exactly easy to get a regular coat of the fluorescent material, but it may be done with a little care. CHAPTER II GLASS-GRINDING AND OPTICIANS' WORK § 52. As no instructions of any practical value in this art have, so far as I know, appeared in any book in English, though a great deal of valuable information has been given in the English Mechanic and elsewhere, I shall deal with the matter sufficiently fully for all practical purposes. On the other hand, I do not propose to treat of all the methods which have been proposed, but only those requisite for the production of the results claimed. The student is requested to read through the chapter before commencing any particular operation. § 53. The simplest way will be to describe the process of manufacture of some standard optical appliance, from which a general idea of the nature of the operations will be obtained. After this preliminary account special methods may be considered in detail. I will begin with an account of the construction of an achromatic object glass for a telescope, not because a student in a physical laboratory will often require to make one, but because it illustrates the usual processes very well; and requires to be well and accurately made. A knowledge of the ordinary principles of optics on the part of the reader is assumed, for there are plenty of books on the theory of lenses, and, in any case, it is my intention to treat of the art rather than of the science of the subject. By far the best short statement of the principles involved which I have seen is Lord Rayleigh's article on Optics in the Encyclopaedia Britannica, and this is amply sufficient. The first question that crops up is, of course, the subject of the choice of glass. It is obvious that the glass must be uniform in refractive index throughout, and that it must be free from air bubbles or bits of opaque matter. [Footnote: The complete testing of glass for uniformity of refractive index can only be arrived at by grinding and polishing a sufficient portion of the surfaces to enable an examination to be made of every part. In the case of a small disc it is sufficient to polish two or three facets on the edge, and to examine the glass in a field of uniform illumination through the windows thus formed. Very slight irregularities will cause a "mirage" easily recognised.] The simplest procedure is to obtain glass of the desired quality from Messrs. Chance of Birmingham, according to the following abbreviated list of names and refractive indices, which may be relied upon:- Density. Refractive Index. C D F G Hard crown 2.85 1.5146 1.5172 1.5232 1.5280 Soft crown 2.55 1.5119 1.5146 1.5210 1.5263 Light flint 3.21 1.5700 1.5740 1.5839 1.5922 Dense flint 3.66 1 6175 1.6224 1.6348 1.6453 Extra dense flint 3.85 1.6450 1.6504 1.6643 1.6761 Double extra dense flint 4.45 1.7036 1.7103 1.7273 ... The above glasses may be had in sheets from 0.25 to 1 inch thick, and 6 to 12 inches square, at a cost of, say, 7s. 6d. per pound. Discs can also be obtained of any reasonable size. Discs 2 inches in diameter cost about £1 per dozen, discs 3 inches in diameter about 10s. each. The price of discs increases enormously with the size. A 16-inch disc will cost about £100. For special purposes, where the desired quality of glass does not appear on the list, an application may be made to the Jena Factory of Herr Schott. In order to give a definite example, I may mention that for ordinary telescopic objectives good results may be obtained by combining the hard crown and dense flint of Chance's list, using the crown to form a double convex, and the flint to form a double concave lens. The convex lens is placed in the more outward position in the telescope, i.e. the light passes first through it. The conditions to be fulfilled are: (1) The glass must be achromatic; (2) it must have a small spherical aberration for rays converging to the principal focus. It is impossible to discuss these matters without going into a complete optical discussion. The radii of curvature of the surfaces, beginning with the first, i.e. the external face of the convex lens, are in the ratio of 1, 2, and 3; an allowance of 15 inches focal length per inch of aperture is reasonable (see Optics in Ency. Brit.), and the focal length is the same as the greatest radius of curvature. Thus, for an object glass 2 inches in diameter, the first surface of the convex lens would have a radius of curvature of 10 inches, the surface common to the convex and concave lens would have a radius of curvature of 20 inches, and the last surface a radius of curvature of 30 inches. This would also be about the focal length of the finished lens. The surfaces in contact have, of course, a common curvature, and need not be cemented together unless a slight loss of light is inadmissible. I will assume that a lens of about 2 inches diameter is to be made by hand, i.e. without the help of a special grinding or polishing machine; this can be accomplished perfectly well, so long as the diameter of the glass is not above about 6 inches, after which the labour is rather too severe. The two glass discs having been obtained from the makers, it will be found that they are slightly larger in diameter than the quoted size, something having been left for the waste of working. It is difficult to deal with the processes of lens manufacture without entering at every stage into rather tedious details, and, what is worse, without interrupting the main account for the purpose of describing subsidiary instruments or processes. In order that the reader may have some guide in threading the maze, it is necessary that he should commence with a clear idea of the broad principles of construction which are to be carried out. For this purpose it seems desirable to begin by roughly indicating the various steps which are to be taken. (1) The glass is to be made circular in form and of a given diameter. (2) Called Rough Grinding. The surfaces of the glass are to be made roughly convex, plane, or concave, as may be required; the glass is to be equally thick all round the edge. In this process the glass is abraded by the use of sand or emery rubbed over it by properly shaped pieces of iron or lead called "tools." (3) The glass is ground with emery to the correct spherical figure as given by a spherometer. (4) Called Fine Grinding. The state of the surface is gradually improved by grinding with finer and finer grades of emery. (5) The glass is polished by rouge. (6) The glass is "figured." This means that it is gradually altered in form by a polishing tool till it gives the best results as found by trial. In processes 2 to 5 counterpart tool surfaces are required--as a rule two convex and two concave surfaces for each lens surface. These subsidiary surfaces are worked (i.e. ground) on discs of cast iron faced with glass, or on slate discs; and discs thus prepared are called "tools." Taking these processes in the order named, the mode of manufacture is shortly as follows:- (1) The disc of glass, obtained in a roughly circular form, is mounted on an ordinary lathe, being conveniently cemented by Regnault's mastic to a small face plate. The lathe is rotated slowly, and the glass is gradually turned down to a circular figure by means (1) of a tool with a diamond point; or (2) an ordinary hand-file moistened with kerosene, as described in § 42; or (3) a mass of brass or iron served with a mixture of emery--or sand--and water fed on to the disc, so that the disc is gradually ground circular. The operation of making a circular disc of given diameter does not differ in any important particular from the similar operation in the case of brass or iron, and is in fact merely a matter of turning at a slow speed. (2 and 3) Roughing or bringing the surfaces of the glass roughly to the proper convex or concave shape. This is accomplished by grinding, generally with sand in large works, or with emery in the laboratory, where the time saved is of more importance than the value of the emery. Discs of iron or brass are cast and turned so as to have a diameter slightly less than that of the glass to be ground, and are, say, half an inch thick. These discs are turned convex or concave on one face according as they are to be employed in the production of concave or convex glass surfaces. The proper degree of convexity or concavity may be approximated to by turning with ordinary turning tools, using a circular arc cut from zinc or glass (as will be described) as a "template" or pattern. This also is a mere matter of turning. The first approximation to the desired convex or concave surface of the glass is attained (in the case of small lenses, say up to three inches diameter) by rotating the glass on the lathe as described above (for the purpose of giving it a circular edge) and holding the tool against the rotating glass, a plentiful supply of coarse emery and water, or sand and water, being supplied between the glass and metal surfaces. The tool is held by hand against the surface of the revolving glass, and is constantly moved about, both round its own axis of figure and to and fro across the glass surface. In this way the glass gradually gets convex or concave. The curvature is tested from time to time by a spherometer, and the tool is increased or decreased in curvature by turning it on a lathe so as to cause it to grind the glass more at the edges or in the middle according to the indications of the spherometer. This instrument, by the way--so important for lens makers--consists essentially of a kind of three-legged stool, with an additional leg placed at the centre of the circle circumscribing the other three. This central leg is in reality a fine screw with a very large head graduated on the edge, so that it is easy to compute the fractions of a turn given to the screw. The instrument is first placed on a flat plate, and the central screw turned till its end just touches the plate, a state of affairs which is very sharply discernible by the slight rocking which it enables the instrument to undergo when pushed by the hand. See the sketch. On a convex or concave surface the screw has to be screwed in or out, and from the amount of screwing necessary to bring all four points into equal contact, the curvature may be ascertained. Let a be the distance between the equidistant feet, and d the distance through which the screw is protruded or retracted from its zero position on a flat surface. Then the radius of curvature rho is given by the formula 2rho = a2/3d +d. Fig. 43. The process of roughing is not always carried out exactly as described, and will be referred to again. (4) The glass being approximately of the proper radius of curvature on one side, it is reversed on the chuck and the same process gone through on the other side. After this the glass is usually dismounted from the lathe and mounted by cement on a pedestal, which is merely a wooden stand with a heavy foot, so that the glass may be held conveniently for the workman. Sometimes a pedestal about four feet high is fixed in the floor of the room, so that the workman engaged in grinding the lens may walk round and round it to secure uniformity. For ordinary purposes, however, a short pedestal may be placed on a table and rotated from time to time by hand, the operator sitting down to his work. Rough iron or brass tools do not succeed for fine grinding--i.e. grinding with fine emery, because particles of emery become embedded in the metal so tightly that they cannot be got out by any ordinary cleaning. If we have been using emery passing say a sieve with 60 threads to the inch, and then go on to some passing say 100 threads to the inch, a few of the coarser particles will adhere to the "tool", and go on cutting and scratching all the time grinding by means of the finer emery is in progress. To get over this it is usual to use a rather different kind of grinding tool. A very good kind is made by cementing small squares of glass (say up to half an inch on the side), on to a disc of slate slightly smaller than the lens surface to be formed (Fig. 51). The glass-slate tool is then "roughed" just like the lens surface, but, of course, if the lens has been roughed "convex" the tool must be roughed "concave". The "roughed" tool is then used to gradually improve the fineness of grinding of the glass. For this purpose grinding by hand is resorted to, the tool and lens being supplied continually with finer and finer emery. Fig. 52 gives an idea of the way in which the tool is moved across the glass surface. Very little pressure is required. The tool is carried in small circular sweeps round and round the lens, so that the centre of the tool describes a many-looped curve on the lens surface. The tool must be allowed to rotate about its own axis; and the lens and pedestal must also be rotated from time to time. Every few minutes the circular strokes are interrupted, and simple, straight, transverse strokes taken. In no case (except to correct a, defect, as will be explained) should the tool overhang the lens surface by more than about one quarter the diameter of the latter. After grinding say for an hour with one size of emery fed in by means of a clean stick say every five minutes, the emery is washed off, and everything carefully cleaned. The process is then repeated with finer emery, and so on. The different grades of emery are prepared by taking advantage of the fact that the smaller the particles the longer do they remain suspended in water. Some emery mud from a "roughing" operation is stirred up with plenty of water and left a few seconds to settle, the liquor is then decanted to a second jug and left say for double the time, say ten seconds; it is decanted again, and so on till four or five grades of emery have been accumulated, each jug containing finer emery than its predecessor in the process. It is not much use using emery which takes more than half an hour to settle in an ordinary bedroom jug. What remains in the liquid to be decanted is mostly glass mud and not emery at all. The process of fine grinding is continually checked by the spherometer, and the art consists in knowing how to move the grinding tool so as to make the lens surface more or less curved. In general it may be said that if the tool is moved in small sweeps, and not allowed to overhang much, the Centre of the lens will be more abraded, while if bold free strokes are taken with much overhanging, the edges of the lens will be more ground away. By the exercise of patience and perseverance any one will succeed in gradually fine grinding the lens surface and keeping it to the spherometer, but the skill comes in doing this rapidly by varying the shape of the strokes before any appreciable alteration of curvature has come about. Polishing. The most simple way of polishing is to coat the grinding tool with paper, as will be described, and then to brush some rouge into the paper. The polisher is moved over the work in much the same way as the fine grinding tool, until the glass is polished. Many operators prefer to use a tool made by squeezing a disc of slate, armed with squares of warm pitch, against the lens surface (finely ground), and then covering these squares with rouge and water instead of emery and water as in the fine grinding process. The final process is called "figuring." It will in general be unnecessary with a small lens. With large lenses or mirrors the final touches have to be given after the optical behaviour of the lens or mirror has been tested with the telescope itself, and this process is called "figuring." A book might easily be written on the optical indications of various imperfections in a mirror or lens. Suffice it to say here that a sufficiently skilled person will be able to decide from an observation of the behaviour of a telescope whether a lens will be improved by altering the curvature of one or all of the surfaces. A very small alteration will make a large difference in the optical properties, so that in general "figuring" is done merely by using the rouge polishing tool as an abrading tool, and causing it to alter the curves in the manner already suggested for grinding. There are other methods based on knocking squares out of the pitch-polisher so that some parts of the glass may be more abraded than others. The "figuring" and polishing may be done by hand just like the grinding. There are machines, however, which can be made to execute the proper motions, and a polisher is set in such a machine, and the mechanical work done is by no means inconsiderable. In fact for surfaces above six inches in diameter few people are strong enough to work a polisher by hand owing to the intense adhesion between it and the exactly fitting glass surface. Such is a general outline of the processes required to produce a lens or mirror. These processes will now be dealt with in much greater detail, and a certain amount of repetition of the above will unfortunately be necessary: the reader is asked to pardon this. It will also be advisable for the reader to begin by reading the whole account before he commences any particular operation. The reason for this is that it has been desirable to keep to the main account as far as possible without inserting special instructions for subsidiary operations, however important they may be; consequently it may not always be quite clear how the steps described are to be performed. It will be found, however, that all necessary information is really given, though perhaps not always exactly in the place the reader might at first expect. § 54. All the discs that I have seen, come from the makers already roughly ground on the edges to a circular figure--but occasionally the figure is very rough indeed--and in some cases, especially if small lenses have to be made, it is convenient to begin by cutting the glass discs out of glass sheet, which also may be purchased of suit-able glass. To do this, the simplest way is to begin by cutting squares and then cutting off the corners with the diamond, the approximate circular figure being obtained by grinding the edges on an ordinary grindstone. If the pieces are larger, time and material may be saved by using a diamond compass, i.e. an ordinary drawing compass armed with a diamond to cut circles on the glass, and breaking the superfluous glass away by means of a pair of spectacle-maker's shanks (Fig. 44), or what does equally well, a pair of pliers with soft iron jaws. With these instruments glass can be chipped gradually up to any line, whether diamond-cut or not, the jaws of the pincers being worked against the edge of the glass, so as to gradually crush it away. Fig. 44. Assuming that the glass has been bought or made roughly circular, it must be finished on the lathe. For this purpose it is necessary to chuck it on an iron or hardwood chuck, as shown in Fig. 46. For a lens below say an inch in diameter, the centering cement may be used; but for a lens of a diameter greater than this, sufficient adhesion is easily obtained with Regnault's mastic, and its low melting point gives it a decided advantage over the shellac composition. The glass may be heated gradually by placing it on the water bath, or actually in the water, and gradually bringing the water up to the boiling-point. The glass, being taken out, is rapidly wiped, and rubbed with a bit of waste moistened, not wet, with a little turpentine: its surface is then rubbed with a stick of mastic previously warmed so as to melt easily. The surface of the chuck being also warm, and covered with a layer of melted cement, it is applied to the glass. The lathe is turned slowly by hand, and the glass pushed gradually into the most central position; it is then pressed tight against the chuck by the back rest, a bit of wood being interposed for obvious reasons. When all is cold the turning may be proceeded with. The quickest way is to use the method already described (i.e. actual turning by a file tool); but if the student prefers (time being no object), he may accomplish the reduction to a circular form very easily by grinding. Fig. 45. Fig. 46. For this purpose he will require to make the following arrangements (Fig. 45). If the lathe has a slide rest, a piece of stout iron may be bent and cut so as to fit the tool rest, and project beneath the glass. The iron must be fairly rigid, for if it springs appreciably beneath the pressure of the glass, it will not grind the latter really round. The lathe may run rather faster than for turning cast iron of the same size. Coarse emery, passing through a sieve of 80 threads to the inch (run), may be fed in between the glass and iron, and the latter screwed up till the disc just grinds slightly as it goes round. A beginner will generally (in this as in all cases of grinding processes) tend to feed too fast--no grinding process can be hurried. If a slide rest is not available, a hinged board, carrying a bit of iron, may (see Fig. 45) be arranged so as to turn about its hinge at the back of the lathe; and it may be screwed up readily enough by passing a long set-screw through the front edge, so that the point of the screw bears upon the lathe bed. I may add that emery behaves as if it were greasy, and it is difficult to wet it with clean water. This is easily got over by adding a little soap or alcohol to the water, or exercising a little patience. A good supply of emery and water should be kept between the disc and the iron; a little putty may be arranged round the point of contact on the iron to form a temporary trough. In any case the resulting emery mud should on no account be thrown away, but should be carefully kept for further use. The process is complete when the glass is perfectly round and of the required diameter as tested by callipers. § 55. The next step is to rough out the lens, and this may easily be done by rotating it more slowly, i.e. with a surface speed of ten feet per minute, and turning the glass with a hard file, as explained in § 42. If it is desired to employ the slide rest, it is quicker and better to use a diamond tool--an instrument quite readily made, and of great service for turning emery wheels and the like,--a thing, in fact, which no workshop should be without. A bit of diamond bort, or even a clear though off-colour stone, may be employed. An ordinary lathe tool is prepared by drawing down the tool steel to a long cone, resembling the ordinary practice in preparing a boring tool. The apex of the cone must be cut off till it is only slightly larger than the greatest transverse diameter of the diamond splinter. The latter may have almost any shape--a triangular point, one side of a three-sided prism is very convenient. A hole is drilled in the steel (which must have been well softened), only just large enough to allow the diamond to enter--if the splinter is thicker in the middle than at either end, so much the better--the diamond is fastened in position by squeezing the soft steel walls tightly down upon it. Personally I prefer to use a tool holder, and in this case generally mount the diamond in a bit of brass rod of the proper diameter; and instead of pinching in the sides of the cavity, I tin them, and set the diamond in position with a drop of soft solder. Fig. 47. In purchasing diamond bort, a good plan is to buy fragments that have been employed in diamond drilling, and have become too small to reset; in this case some idea as to the hardness of the bits may be obtained. Full details as to diamond tool-making are given in books on watch-making, and in Holtzapffell's great work on Mechanical Manipulation; but the above notes are all that are really necessary--it is, in fact, a very simple matter. The only advantage of using a diamond tool for glass turning is that one does not need to be always taking it out of the rest to sharpen it, which generally happens with hard steel, especially if the work is turned a little too fast. I recommend, therefore, that the student should boldly go to work "free hand" with a hard file; but if he prefer the more formal method, or distrust his skill (which he should not do), then let him use a diamond point, even if he has the trouble of making it. When using a diamond it is not necessary to employ a lubricant, but there is some advantage in doing so. The surface of the lens can be roughly shaped by turning to a template or pattern made by cutting a circular arc (of the same radius as the required surface) out of a bit of sheet zinc. Another very handy way of making templates of great accuracy is to use a beam compass (constructed from a light wooden bar) with a glazier's diamond instead of a pencil. A bit of thin sheet glass is cut across with this compass to the proper curvature--which can be done with considerable accuracy and the two halves of the plate, after breaking along the cut, are ground together with a view to avoiding slight local irregularities, by means of a little fine emery and water laid between the edges. In this process the glass is conveniently supported on a clean board or slate, and the bits are rubbed backwards and forwards against each other. § 56. It is not very easy for a beginner to turn a bit of anything--iron, wood, or glass--with great accuracy to fit a template, and consequently time may be saved by the following procedure, applied as soon as the figure of the template is roughly obtained. A disc of lead or iron, of the same diameter as the glass, and of approximately the proper curvature, is prepared by turning, and is armed with a handle projecting coaxially from the back of the disc. The glass revolving with moderate speed on the lathe, the lead tool, supplied with coarse emery and water, is held against it, care being taken to rotate the tool by the handle, and also to move it backwards and forwards across the disc, through a distance, say, up to half an inch; if it is allowed to overhang too much the edges of the glass disc will be overground. By the use of such a tool the glass can readily be brought up to the template. The only thing that remains, so far as the description of this part of the process goes, is to give a note or two as to the best way of making the lead tools, and for this purpose the main narrative of processes must be interrupted. The easiest way is to make a set of discs to begin with. For this purpose take the mandrel out of the lathe, and place it nose downwards in the centre of an iron ring of proper diameter on a flat and level iron plate. The discs are made by pouring lead round the screw-nose of the mandrel. This method, of course, leaves them with a hole in the centre; but this can be stopped up by placing the hot disc (from which the mandrel has been unscrewed) on a hot plate, and pouring in a sufficiency of very hot lead; or, better still, the mandrel can be supported vertically at any desired distance above the plate while the casting is being poured. Lead discs prepared in this way are easily turned so as to form very convenient chucks for brass work, and for use in the case now being treated, they are easily turned to a template, using woodturners' tools, which work better if oiled, and must be set to cut, not scrape. If the operator does not mind the trouble of cutting a screw, or if he has a jaw chuck, the lead may be replaced by iron with some advantage. The following is a neat way of making concave tools. It is an application of the principle of having the cutting tool as long as the radius of curvature, and allowing it to move about the centre of curvature. Place the disc of iron or lead on the lathe mandrel or in the chuck, and set the slide rest so that it is free to slide up or down the lathe bed. Take a bar of tool steel and cut it a little longer than the radius of curvature required. Forge and finish one end of the bar into a pointed turning tool of the ordinary kind. Measure the radius of curvature from the point of the tool along the bar, and bore a hole, whose centre is at this point, through the bar from the upper to the lower face. I regard the upper face as the one whose horizontal plane contains the cutting point when the tool is in use. Clamp a temporary back centre to the lathe bed, and let it carry a pin in the vertical plane through the lathe centres, and let this pin exactly fit the hole in the bar. Fig. 48. Place the "radius" tool in position for cutting, and let it be lightly held in the slide rest nearly at the cutting point, the centre of rotation of the pedestal (or its equivalent) passing through the central line of the bar. Then adjust the temporary back rest, so that the tool will take a cut. In the sketch the tool is shown swinging about the back centre instead of about a pin--there is little to choose between the methods unless economy of tool steel is an object. The tool must now be fed across the work. The pedestal must of course be free to rotate, and the slide rest to slip up and down the bed. In this way a better concave grinding tool can be made than would be made by a beginner by turning to a template--though an expert turner would probably carry out the latter operation so as to obtain an' accuracy of the same order, and would certainly do it in much less time than would be required in setting up the special arrangements here described. On the other hand, if several surfaces have to be prepared, as in the making of an achromatic lens, the quickest way would be by the use of the radius tool, bored of course to work at the several radii required. I have tried both methods, and my choice would depend partly on the lathe at my disposal, and partly on the number of grinding tools that had to be prepared. Having obtained a concave tool of any given radius, it is easily copied--negatively, so as to make a convex tool in the following manner. Adjust the concave tool already made on the back rest, so that if it rotated about the line of centres, it would rotate about its axis of figure. Arrangements for this can easily be made, but of course they will depend on the detailed structure of the lathe. Use the slide rest as before, i.e. let it grasp an ordinary turning tool lightly, the pedestal being fixed, but the rest free to slide up or down the lathe bed. Push the back rest up till the butt of the turning tool (ground to a rounded point) rests against the concave grinding tool. If the diameter of the convex tool required be very small compared with the radius of curvature of the surface (the most usual case), it is only necessary to feed the cutting tool across to "copy" the concave surface sufficiently nearly. Fig. 49. There seems no reason, however, why these methods should not be applied at once to the glass disc by means of a diamond point, and the rough grinding thus entirely avoided. I am informed that this has been done by Sir Henry Bessemer, but that the method was found to present no great advantage in practice. A reader with a taste for mechanical experimenting might try radius bar tools with small carborundum wheels rapidly driven instead of a diamond. Enough has now been said to enable any one to prepare rough convex or concave grinding tools of iron or lead, and of the same diameter as the glass to be ground. The general effect of the process of roughing the rotating lens surface is to alter the radius of curvature of both tool and glass; hence it is necessary to have for each grinding tool another to fit it, and enable it to be kept (by working the two together) at a constant figure. After a little practice it will be found possible to bring the glass exactly up to the required curvature as tested by template or spherometer. The art of the process consists in altering the shape of the grinding tool so as to take off the glass where required, as described in § 53, and from this point of view lead has some advantages; (opinions vary as to the relative advantages of lead and iron tools for this purpose, however). The subsidiary grinding tool is not actually needed for this preliminary operation, but it has to be made some time with a view to further procedure, and occasionally is of service here. § 57. 'The glass disc must be ground approximately to the proper curvature on each side before any fine grinding is commenced. It is precisely for this purpose that the previous turning of the disc is recommended, for it is easy to unmount and recentre a round object, but not so easy if the object have an indefinite shape. Using a cement which is plastic before it sets, the disc may be easily taken off the chuck and centred by a little handicraft, i.e. by rotating the lathe slowly and pushing the disc into such a position that it rotates about its axis. The grinding of the second surface is accomplished exactly as in the former case; of course on reversing the glass the chuck has to be slightly turned up to fit the convex or concave surface. § 58. There is, however, one point of interest and importance--attention to which will save a good deal of useless labour afterwards. The glass must be ground in such a manner that the thickness at the edge is the same all round. In other words, the axes of figure of the two surfaces must coincide. This will be the case if the recentering has been accurately performed, and therefore no pains should be spared to see that it is exactly carried out. Any simple form of vernier gauge (such as Brown and Sharpe's vernier callipers) will serve to allow of a sufficiently accurate measurement of the edge thickness of the lens. If any difference of thickness is observed as the gauge moves round the edge, one or other of the surfaces must be reground. Of course the latitude of error which may be permitted depends so much on the final arrangements for a special finishing process called the "centering of the lens"--which will be described--that it is difficult to fix a limit, but perhaps one-thousandth of an inch may be mentioned as a suitable amount for a 2-inch disc. For rough work, of course; more margin may be admitted. § 59. In a large shop I imagine that lenses of only two inches diameter would be ground in nests; or, in other words, a number would be worked at a time, and centering, even of a rough kind, would be left to the last; but this process will be treated hereafter. At present I shall assume that only one lens will be made at a time. Consequently we now enter on the stage of fine grinding by hand. A leaden pedestal, for the sake of stability, must be provided on which to mount the lens, so that the surface to be operated on may be nearly horizontal (Fig. 50). Before this can be done, however, fresh grinding tools (two for each surface) must be properly prepared. After trying several plans I unhesitatingly recommend that all fine-grinding surfaces should be made of glass. This is easily done by taking two discs of lead, or iron, or slate, cut to a one-tenth inch smaller radius of curvature (in the case of a convex tool, and the opposite in the other case) than the lens surface (Fig. 51, A). On these, square bits of sheet glass, one-tenth of an inch thick, are to be cemented, so as to leave channels of about one-eighth of an inch between each bit of glass (Fig. 52, B). The "mastic" cement formerly described may be employed for this purpose. Fig. 50. The bits of glass ought first to have their edges dressed smooth on the grind-stone. A convex and concave glass surface having been thus roughly prepared, they must be mounted in turn in the lathe, and brought to the proper curvature by grinding with the tools formerly employed and tested by the template or spherometer. It is well to control this process by means of a spherometer, so that the desired radius may be approximately reached. The two glass-grinding tools are then ground together by hand (see § 53 and § 61), the spherometer being employed from time to time to check the progress of the work. In general, if large circular sweeps are taken, greatly overhanging the side of the glass surface to be figured, both the upper and lower surfaces will be more ground at the edges, while in the opposite event the centre will be chiefly affected. Fig. 51. A spherometer capable of measuring a 2-inch surface may be procured, having a screw of, say, 50 threads to the inch, and a micrometer surface divided into 200 parts, each part easily capable of subdivision--into tenths or even twentieths. To get the full advantage of the spherometer it must screw exceedingly freely (i.e. must be well oiled with clock oil), and must not be fingered except at the milled head. If one of the legs is held by the fingers the expansion is sufficient to throw the instrument quite out of adjustment. The glass-grinding tools being brought to the proper figure, the next process is to transfer the same to the lens, and this is done by similar means, the fellow tool being used to correct the one employed in grinding the lens surface. Before the grade of emery is changed all three surfaces must agree, as nearly, at least, as the spherometer will show. In order to prevent confusion the following summary of the steps already taken may be given. The discs of glass are first ground or turned so as to be truly circular. Four "tools" are made for each surface--a rough pair of iron or lead, and a finishing pair of iron, lead, or slate faced by glass squares. For a small lens the iron or lead backing may be used, for a large one the slate. The rough tools are used to give an approximate figure both to the lens and to the finishing tools. The final adjustment is attained by grinding one of the glass-faced tools alternately upon the lens and upon the fellow glass-faced tool. The spherometer is accepted at all stages of the process as the final arbiter as to curvature. Some hints on the form of strokes used in grinding will be given later on (see § 61). It suffices to state here that the object throughout is to secure uniformity by allowing both the work and the tool to rotate, and exercising no pressure by the fingers. The tool backing may weigh from one to two pounds for a 2-inch lens. § 60. The tools and lens being all of the same curvature, the state of the surface is gradually improved by grinding with finer and finer emery. The best way of grading the emery is by washing it with clean water, and allowing the emery (at first stirred up with the water) to settle out. The longer the time required for this part of the process the finer will be the emery deposited. An ordinary bedroom jug is a very good utensil to employ during this process; a large glass jug is even better. The following grades will be found sufficient, though I daresay every operative's practice differs a little on this point. 1st grade: Flour emery, with the grit washed out, i.e. allowed to stand for 2" (sec.) before being poured off. 2nd grade: Stand 5" (secs.), settle in 1' (min.) 3rd grade: Stand 1', settle in 10'. 4th grade: Stand 10', settle in 60'. It is generally advisable to repeat the washing process with each grade. Thus, selecting grade 2 for illustration, the liquor for grade 3 must be poured off without allowing any of the sediment to pass over with it. If any sediment at all passes, one has no security against its containing perhaps the largest particle in the jug. As soon as the liquor for No. 3 has been decanted, jug No. 2 is filled up again with clean water (filtered if necessary), and after standing 5" is decanted into jug No. 2b, the sediment is returned to jug No. 1, and the liquor, after standing 1', is transferred to jug No. 3. The greatest care is necessary at each step of the operation to prevent "sediment" passing over with liquor. There is a little danger from the tendency which even comparatively large particles of emery have to float, in consequence of their refusing to get wet, and the emery worked up on the side of the jug is also a source of danger, therefore wipe the jug round inside before decanting. In order to get a uniform grade stop the currents of water in the jug, which may work up coarse particles, by holding a thin bit of wood in the rotating liquid for a moment, and then gently withdrawing it in its own plane. These precautions are particularly necessary in the case of grades Nos. 2, 3, and 4, especially No. 4, for if a single coarse particle gets on the tool when the work has progressed up to this point it will probably necessitate a return to grinding by means of No. 2, and involve many hours' work. The surface of the lens will require to be ground continuously with each grade till it has the uniform state of roughness corresponding to the grade in question. Two hours for each grade is about the usual time required in working such a lens as is here contemplated. The coarser grades of emery may be obtained by washing ordinary flour of emery, but the finer ones have to be got from emery which has been used in the previous processes. It is not a good plan to wash the finer grades of emery out of the proceeds of very rough grinding say with anything coarser than flour of emery--as there is a danger of thereby contaminating the finer grades with comparatively coarse glass particles (owing to their lightness) and this may lead to scratching. If the finer grades are very light in colour, it may be inferred that a considerable portion of the dust is composed of glass, and this does no good. Consequently time may be saved by stirring up the light-coloured mass with a little hydrofluoric acid in a platinum capsule; this dissolves the finely divided glass almost instantaneously. The emery and excess of hydrofluoric acid may then be thrown into a large beaker of clean water and washed several times. Fine emery thus treated has much the same dark chocolate colour as the coarser varieties. The operator should not wear a coat, and should have his arms bare while working with fine emery, for a workshop coat is sure to have gathered a good deal of dust, and increases the chances of coarse particles getting between the surfaces. § 61. Details of the Process of Fine Grinding. A lens of the size selected for description is mounted as before mentioned on a leaden pedestal, and the operator places the latter on a table of convenient height in a room as free from dust as possible. Everything should be as clean as a pin, and no splashes of emery mud should be allowed to lie about. I have found it convenient to spread clean newspapers on the table and floor, and to wear clean linen clothes, which do not pick up dust. I have an idea that in large workshops some simpler means of avoiding scratches must have been discovered, but I can only give the results of my own experience. I never successfully avoided scratches till I adopted the precautions mentioned. Fig. 52. The left hand should be employed in rotating the pedestal either continuously (though slowly) or at intervals of, say, one minute. This point is rather important. Some operators require two hands to work the grinding tool, and in any case this is the safer practice. Under these circumstances the pedestal may be rotated through one-eighth or tenth of a revolution every three minutes, or thereabouts. The general motion given to the grinding tool should be a series of circular sweeps of about one-fourth the diameter of the glass disc, and gradually carried round an imaginary circle drawn on the surface of the lens and concentric with it (Fig. 52). The tool may overhang the lens by a quarter of the diameter of the latter as a maximum. The circuit may be completed in from twelve to thirty sweeps. The grinding tool should be lightly held by the fingers and the necessary force applied parallel to the surface. The tool itself must be slowly rotated about its axis of figure. If the tool be lightly held, it will be found that it tends to rotate by itself. I say "tends to rotate," for if the tool be touching evenly all over the surface it will rotate in a direction opposite to the direction of the circular sweep. For instance, if the tool be carried round its looped path clockwise, it will tend to rotate about its own axis of figure counter-clockwise. If it touch more in the middle, this rotation will be increased, while if it touches more along the edge, the rotation will be diminished, or even reversed in an extreme case. Every fifty sweeps or so the tool should be simply ground backwards and forwards along a diameter of the lens surface. This grinding should consist of three or four journeys to and fro along, say, eight different diameters. About one-quarter of the whole grinding should be accomplished by short straight strokes, during which the tool should only overhang about one-quarter of an inch. The object of the straight strokes is to counteract the tendency to a gradual accumulation of the emery in the centre, which results from the circular grinding. A great deal of the art of the process consists in knowing how to work the tool to produce any given effect. For instance, if the lens requires to be ground down near the centre, the epicycloidal strokes must be nearly central; the tool must never overhang very much. If, on the other hand, it is the edges which require attention, these must be dealt with by wider overhanging strokes. The tool must be frequently tested on its fellow, and, indeed, ground upon it if any marked unevenness of action (such as that just described) is required for the lens. A check by spherometer will be applied at intervals according to the judgment of the operator, but, in any case, the fellow tool and lens should be kept at very nearly the same figure. The emery should never be allowed to become anything like dry between the tool and the lens, for in some way (probably by capillary action increasing the pressure of the tool) this seems to lead to scratching and "rolling" of the emery. The channels in the glass tool between the squares are of the greatest importance in enabling the emery to distribute itself. Perhaps the best guide in enabling one to judge as to when it is time to wash off the emery and apply fresh is the "feel" of the tool; also when the mud gets light in colour we know that it is full of glass dust, and proportionately inoperative. New emery may be put on, say, every five minutes, but no absolute rule can be given, for much depends on the pressure of the tool upon the lens. In the case considered a brass or lead, or even slate tool, of an inch, or even less, in thickness, will press quite heavily enough. In washing the lens and tool before new emery is introduced, a large enamelled iron bucket is very handy; the whole of the tool should be immersed and scrubbed with a nail-brush. The lens surface may be wiped with a bit of clean sponge, free from grit, or even a clean damp cloth. When the time comes to alter the grade of emery, a fresh lot of newspapers should be put down, and tools, lens, and pedestal well washed and brushed by the nail-brush. The surfaces should be wiped dry by a fresh piece of rag, and examined for scratches and also for uniformity of appearance; a good opinion can be formed as to the fit of the surfaces by noting whether--and if so, to what degree--they differ in appearance from point to point when held so that the light falls on them obliquely. It is necessary to exercise the greatest care in the washing between the application of successive grades of emery, and this will be facilitated if the edges of the glass squares were dressed on a grindstone before they were mounted. An additional precaution which may be of immense advantage is to allow the tool to dry between the application of successive grades of emery (of course, after it has been scrubbed), and then to brush it vigorously with a hat-brush. It sometimes happens that particles of mud which have resisted the wet scrubbing with the nail-brush may be removed by this method. As my friend Mr. Cook informs me that his present practice differs slightly from the above, I will depart from the rule I laid down, and add a note on an alternative method. Consider a single lens surface. This is roughed out as before by an iron tool, a rough fellow tool being made at the same time. The squares of glass are cemented to the roughing tool, and this is ground to the spherometer by means of the counterpart tool. The glass-coated tool is then applied to the lens surface and grinding with the first grade of emery commenced. The curvature is checked by the spherometer. Two auxiliary tools of, say, half the diameter of the lens, are prepared from slate, or glass backed with iron, and applied to grind down either the central part of the lens surface or tool surface, according to the indications of the spherometer. Any changes that may occur during grinding are corrected by these tools. The spherometer is accepted as the sole guide in obtaining the proper curvature. A slate backing is preferred for tools of any diameter over, say, 2 inches. § 62. Polishing. After the surface has been ground with the last grade of emery, and commences to become translucent even when dry, the grinding may be considered to be accomplished, and the next step is the polishing. There are many ways of carrying out this process, and the relative suitability of these methods depends on a good many, so to speak, accidental circumstances. For instance, if the intention is to finish the polishing at a sitting, the polishing tool may be faced with squares of archangel--not mineral or coal-tar--pitch and brought to shape simply by pressing while warm against the face of the lens. A tool thus made is very convenient, accurate, and good, but it is difficult to keep it in shape for any length of time; if left on the lens it is apt to stick, and if it overhangs ever so little will, of course, droop at the edges. On the whole, the following will be found a good and sufficient plan. The glass-grinding tool is converted into a polishing tool by pasting a bit of thin paper over its surface; a bit of woven letter paper of medium thickness with a smooth but not glazed surface does very well. We have found that what is called Smith's "21 lbs. Vellum Wove" is excellent. This is steeped in water till quite pliable and almost free from size. The glass tool is brushed over with a little thin arrowroot or starch paste, and the paper is laid upon it and squeezed down on the glass squares as well as possible; if the paper is wet enough and of the proper quality it will expand sufficiently to envelop the tool without creases, unless the curvature is quite out of the common. This being accomplished, and the excess of water and paste removed, the face of the paper is (for security) washed with a little clean water and a bit of sponge, and, finally, the tool is slightly pressed on the lens so as to get the paper to take up the proper figure as nearly as possible. After the polishing tool has been thus brought to the proper figure, it is lifted off and allowed to dry slowly. When the paper is dry it may be trimmed round the edges so as not to project sensibly beyond the glass squares. The next step is to brush the surface over very carefully with polishing rouge (prepared as is described at the end of this section) by means of a hat-brush. When the surface of the paper is filled with rouge all excess must be removed by vigorous brushing. Fig. 53. The tool being placed on the lens, two or three strokes similar to those used in grinding may be taken, and the tool is then lifted off and examined. It will be found to be dotted with a few bright points, produced by the adhesion of glass at the places of contact. These points are then to be removed in the following manner. An old three-cornered file is ground on each side till the file marks disappear, and sharp edges are produced (Fig. 53). This tool is used as an ink eraser, and it will be found to scrape the paper of the polishing tool very cleanly and well. The bright spots are the objects of attention, and they must be erased by the old file, and the polisher reapplied to the glass. A few strokes will develop other points, more numerous than before, and these in turn must be erased. The process is continued till the whole surface of the polishing tool is evenly covered with bright specks, and then the polishing may be proceeded with. The specks should not be more than about one-eighth of an inch apart, or the polishing will be irregular. The operation of polishing is similar to that of grinding. A reasonable time for polishing a glass surface is twenty hours; if more time is required it is a sign that the fine grinding has not been carried far enough. The progress of the operation may be best watched by looking at the surface--not through it. For this purpose a good light is requisite. When the lens is dismounted it may be examined by a beam of sunlight in a dark room, under which circumstances the faintest signs of grayness are easily discernible. It may be mentioned here that if the surface is in any way scratched the rouge will lodge in the scratches with great persistence, and an expert can generally tell from the appearance of scratches what kind of polishing powder has been employed. The persistence with which rouge clings to a rough surface of glass is rather remarkable. Some glass polishers prefer to use putty powder as a polishing material, and it is sometimes said to act more quickly than rouge; from my rather limited experience I have not found this to be the case, but it may have merits that I do not know of. Is it possible that its recommendation lies in the fact that it does not render scratches so obtrusively obvious as rouge does? Rouge is generally made in two or more grades. The softer grade is used for polishing silver, and is called jewellers' rouge. The harder grade, suitable for glass polishing, is best obtained from practical opticians (not mere sellers of optical instruments). I mean people like Messrs. Cook of York. Many years ago I prepared my own hard rouge by precipitating ferrous sulphate solution by aqueous ammonia, washing the precipitate, and heating it to a red heat. The product was ground up with water, and washed to get rid of large particles. This answered every purpose, and I could not find that it was in any way inferior to hard rouge as purchased. The same precipitate heated to a lower temperature is said to furnish a softer variety of rouge; at all events, it gives one more suitable for polishing speculum metal. Lord Rosso used rouge heated to a dull redness for this purpose. Rouge, whether made or bought, should always be washed to get rid of grit. I ought to add that not the least remarkable fact about the polishing is the extraordinarily small quantity of the polishing material requisite, which suggests that the process of polishing is not by any means the same as that of exceptionally fine grinding. Is it possible that the chief proximate cause of the utility of rouge is to be sought in its curious property of adhering to a rough glass surface, causing it, so to speak, to drag the glass off in minute quantities, and redeposit it after a certain thickness has been attained on another part of the surface? § 63. Centering. When a lens is ground and polished it will almost always happen that the axis of revolution of its cylindrical edge is inclined to the axis of revolution of its curved surfaces. Since in practice lenses have to be adjusted by their edges, it is generally necessary to adjust the edge to a cylinder about the axis of figure of the active surfaces. This is best done on a lathe with a hollow mandrel.. The lens is chucked on a chuck with a central aperture--generally by means of pitch or Regnault's mastic, or "centering" cement for small lenses--and a cross wire is fixed in the axis of revolution of the lathe, and is illuminated by a lamp. This cross wire is observed by an eye-piece (with cross wires only in the case of a convex lens, or a telescope similarly furnished in the case of a concave lens), also placed in the axis of rotation of the lathe. Both cross wires are thus in the axis of revolution of the mandrel, and the distant one (B in the figure) is viewed through the lens and referred to the fixed cross wires at A. In general, as the lathe is rotated by turning the mandrel the image of the illuminated cross wires will be observed to rotate also. The lens is adjusted until the image remains steady on rotating the mandrel and it is to give time for this operation that a slow-setting cement is recommended. When the image remains stationary we know that the optical centre of the lens is in the axis of revolution, and that this axis is normal to both lens surfaces, i.e. is the principal axis of the lens, or axis of figure. Fig. 54. A much readier method, and one, in general, good enough for most purposes, is to put a candle on the end of the lathe-bed where the back centre generally is, and observe the images of the flame by reflection from both the lens surfaces. This method is very handy with small lenses; the mandrel is turned, and the lens adjusted by hand till the images are immovable. In both cases, of course, the edge of the lens is turned or ground till it is truly circular, the position of the lens remaining undisturbed on the chuck. If the edge gauge has been properly used in the earlier stages of figuring, it will be found that very little turning or grinding is requisite to produce a true centering. The particular defect due to want of centering in a lens may be observed by using it as the objective of a telescope, and observing a star slightly out of focus. The interference fringes will not be concentric circles unless the lens is properly centred. I ought to say that I have not looked into the theory of this, but have merely taken it as a generally admitted fact. The diseases of lenses and the modes of treating them are dealt with in a book by Messrs. Cook of York, entitled On the Adjustment and Testing of Telescopic Objectives. The final process of figuring will be dealt with later on (§ § 66 and 67), as it applies not only to lenses but to mirrors, prisms, etc. If the instructions given have been carefully carried out on a 2-inch lens, it should perform fairly well, and possibly perfectly, without any further adjustment of the glass. § 64. Preparation of Small Lenses, where great Accuracy is not of the first Importance. Such lenses may generally be made out of bits of good plate or sheet glass, and are of constant use in the physical laboratory. They may be purchased so cheaply, however, that only those who have the misfortune to work in out-of-the-way places need be driven to make them. Suitable glass having been obtained and the curves calculated from the index of refraction, as obtained by any of the ordinary methods applicable to plates (the microscope method, in general, is quite good enough), squares circumscribing the desired circles are cut out by the help of a diamond. [Footnote: Glazebrook and Shaw's Practical Physics, p. 383 (4th ed.).] The squares are roughly snipped by means of a pair of pliers or spectacle-maker's shanks. The rough circles are then mounted on the end of a brass or iron rod of rather greater diameter than the finished lenses are to possess. This mounting is best done by centering cement. The discs are then dressed circular on a grindstone, the rod serving both as a gauge and handle. A sufficient number of these discs having been prepared, a pair of brass tools of the form shown in the sketch (Fig. 55), and of about the proper radius of curvature, are made. One of these tools is used as a support for the glass discs. Fig. 55. A compass being set to scribe circles of the same diameter as the glass discs, centre marks are made on the surface of the appropriate tool, circles are drawn on this, and facets are filed or milled (for which the spiral head of the milling machine is excellent). In the case of concave supporting surfaces, i.e. in making concave lenses, I apprehend filing would be difficult, and the facets would have to be made by a rose cutter or mill; but if the discs are fairly round, then, in fact, no facets are required. The facets being ready, the glass discs are cemented to them by centering cement, which may be used quite generally for small lenses. When the cutting of facets has been omitted on a concave surface, the best cement is hard pitch. The grinding tool is generally rather larger than the nest of lenses. Coarse and fine grinding is accomplished wholly on the lathe--the tool being rotated at a fair speed (see infra), and the nest of lenses moved about by its handle so as to grind all parts equally. It must, of course, be held anywhere except "dead on," for then the part round the axis would not get ground; this inoperative portion of the rotating tool must therefore be allowed to distribute its incapable efforts evenly over the nest of lenses. Polishing is accomplished by means of the grinding tool, coated with paper and rouge as before; or the tool may be coated with very thin cloth and used with rouge as before--in this case the polishing goes on fastest when the surface of the cloth is distinctly damp. In working by this method, each grade of emery need only be applied from five to ten minutes. The glass does not appear to get scratched when the emery is changed, provided everything is well washed. A good polish may be got in an hour. The lathe is run as for turning brass of the same diameter as the tool. One side of the lenses being thus prepared, they are reversed, and the process gone through for the other side in a precisely similar manner. [Footnote: Unless the radius of curvature is very short and the lenses also convex, there is no necessity to recess the facets, provided hard pitch is used as the cement. See note on hard pitch.] To save trouble, it is usual, to make such lenses of equal curvature on both faces; but of course this is a matter of taste. Fig. 56. For very common work, bits of good plate glass are employed, and the manufacturer's surface treated as flat (Fig. 56). In this way plano-convex lenses are easily and cheaply made. Finally the lenses have to be centred, an essential operation in this case. This is easily done by the reflection method--the edge being turned off by the file and kerosene and the centering cement being used in making the preliminary adjustment on the chuck. I presume a lens made in this way is worth about a shilling, so that laboratory manufacture is not very remunerative. Fig. 56 shows the method of mounting small lenses for lathe grinding, when only one lens is required. The tool is generally rotated in the lathe and the lens held against it. § 65. Preparing Small Mirrors for Galvanometers. To get good mirrors for galvanometers, I have found the best plan is to grind and polish a large number together, on a disc perhaps 8 or 10 inches in diameter. I was led to this after inspecting and rejecting four ounces of microscope cover slips, a most wearisome process. That regular cover slips should be few and far between is not unlikely, seeing that they are made (by one eminent firm at least) simply by "pot" blowing a huge thin bulb, and then smashing it on the floor and selecting the fragments. As in the case of large mirrors, it is of course only necessary to grind one side of the glass, theoretically at all events. The objections to this course are: (1) A silver surface cannot, in my experience, be polished externally (on a minute object like a cover slip) to be anything like so bright as the silver surface next the glass; and, (2) if one side only is ground, it will be found that the little mirror hopelessly loses its figure directly it is detached from the support on which it has been worked. Consequently, I recommend that these small mirrors should be ground and polished on both sides--enough may be made at one operation to last for a very long time. A slate back is prepared of the same radius of curvature as it is desired to impart to the mirrors. Bits of thin sheet glass are then ground circular as described in the last section and cemented to this surface by the smallest quantity of clean archangel pitch, allowed to cool slowly and even to rest for a day before the work is proceeded with. The whole surface is then ground and polished as before. The mirrors are now reversed, when they ought to nearly fit the tool (assuming that flats are being made, and the fellow tool in all other cases), and are recemented by pitch to the appropriate backing ground, and polished. If very excellent results are required, these processes may be preceded by a preliminary rough grinding of one surface, so that the little discs will "sit" exactly on the tool surface, and not run the risk of being strained by capillary forces in the pitch. We have always found this necessary for really good results. On removing such mirrors from the backing, they generally, more or less lose their figure, becoming (in general fairly uniformly) more concave or convex. About 5 per cent of the mirrors thus prepared will be found almost perfect if the work has been well done, and the rest will probably be very fair, unless the diameter is very large as compared with the thickness. The best way of grinding and polishing such large surfaces (nests 10 inches in diameter) is on a grinding machine, such as will be described below. The polishing is best done by means of paper, as before described. Having occasion to require hitherto unapproached lightness and optical accuracy in such mirrors, I got my assistant to try making them of fused quartz, slices being cut by a diamond wheel from a rod of that material. Chips of natural quartz were also obtained from broken "pebble" spectacles, and these were worked at the same time. The resulting mirrors were certainly superior to the best we could make from glass, but the labour of grinding was greater, and the labour of polishing less, than in the latter case. The pebble fragments gave practically as good mirrors as the fused slices. For the future it will be better always to make galvanometer mirrors from quartz crystals. These may be easily sliced, as will be described in § 74. The slices are dressed on a grindstone according to instructions already given for small lenses. The silvering of these mirrors is a point of great importance. After trying nearly every formula published, we have settled down to the following. A solution of pure crystallised nitrate of silver in distilled water is made up to a strength of 125 grams of the salt per litre. This forms the stock solution and is kept in a dark bottle. Let the volume of silvering liquor required in any operation be denoted by 4 v. The liquor is prepared as follows: I. Measure out a volume v of the stock solution of silver nitrate, and calculate the weight of salt which it contains; let this be w. In another vessel dissolve pure Rochelle salt to the amount of 2.6 w, and make up the solution to the volume v. These two solutions are to be mixed together at a temperature of 55° C, the vessels with their contents being heated to this temperature on the water bath. After mixing the liquids the temperature is to be kept approximately constant for five minutes, after which the liquor may be cooled. The white precipitate which first forms will become gray or black and very dense as the liquid cools. If it does not, the liquor must be reheated to 55° C, and kept at that temperature for a few minutes and then again allowed to cool. The solution is in good order when all the precipitate is dense and gray or black and the liquor clear. The blacker and denser the precipitate the better is the solution. The liquor is decanted and filtered from the precipitate and brought up to the volume 2 v by addition of some of the wash water. II. Measure out a volume 0.118 v of the stock solution into a separate vessel, and add to it a 5 per cent solution of ammonium hydrate, with proper precautions, so that the precipitate at first formed is all but redissolved after vigorous shaking. It is very important that this condition should be exactly attained. Therefore add the latter part of the ammonia very carefully. Make up the volume to 2 v. Mix the solutions I. and II. in a separate vessel and pour the mixture into the depositing vessel. The surface to be silvered should face downwards, and lie just beneath the free surface of the liquid. Bubbles must of course be removed. The silver deposit obtained in this manner is exceedingly white and, bright on the surface next to the glass, but the back is mat and requires polishing. The detail of the process described above was worked out in my laboratory by Mr. A. Pollock, to whom my thanks are due. This process gives good deposits when the solutions are freshly prepared, but the ammonia solution will not keep; The surfaces to be silvered require to be absolutely clean. The process is assisted by a summer temperature, say 70° Fahr, and possibly by the action of light. Six or seven hours at least are required for a good deposit; a good plan is to leave the mirrors in the bath all night. On removal from the bath the mirrors require to be well washed, and allowed to dry thoroughly in sun heat for several hours before they are touched. Care should be taken not to pull the mirrors out of shape when they are mounted for the bath. A single drop of varnish or paint (a mere speck) on the centre will suffice to hold them. The back of the deposit requires to be varnished or painted as a rule to preserve the silver. All paints and varnishes thus applied tend to spoil the figure by expanding or contracting. On the whole, I think boiled linseed oil and white or red lead--white or red paint in fact--is less deleterious than other things I have tried. Shellac varnish is the worst. Of course, the best mirror can be easily spoiled by bad mounting. I have tried a great number of methods and can recommend as fairly successful the following:- A little pure white lead, i.e. bought as pure as a chemical--not as a paint--is mixed with an equal quantity of red lead and made into a paste with a little linseed oil. I say a paste, not putty. A trace of this is then worked on to the back of the mirror at the centre as nearly as may be, and to this is attached the support. The only objection to this is that nearly a week is required for the paste to set. If people must use shellac let it be remembered that it will go on changing its shape for months after it has cooled (whether it has been dissolved in alcohol or not). § 66. Preparation of Large Mirrors or Lenses for Telescopes. So much has been written on this subject by astronomers, generally in the English Mechanic and in the Philosophical Transactions for 1840, that it might be thought nothing could be added. I will only say here that the processes already described apply perfectly to this case; but of course I only refer to silver on glass mirrors. For any size over 6 inches in diameter, the process of grinding and polishing by hand, particularly the latter, will probably be found to involve too much labour, and a machine will be required. A description of a modification of Mr. Nasmyth's machine--as made by my assistant, Mr. Cook--will be found below. There is no difficulty in constructing or working such a machine, and considered as an all round appliance, it possesses solid advantages over the simple double pulley and crank arrangement, which, however, from its simplicity deserves a note. Two pulleys, A and B, of about 18 inches diameter by 4 inches on the face, are arranged to rotate about vertical axes, and belted together. The shaft of one of these pulleys is driven by a belt in any convenient manner. Each pulley is provided on its upper surface with a crank of adjustable length carrying a vertical crank-pin. Each crank-pin passes through a 3"X 2" wooden rod, say 3' 6" long, and these rods are pinned together at their farther extremities, and this pin carries the grinding or polishing tool, or rather engages loosely with the back of this tool which lies below the rod. It is clear that if the pulleys are of commensurable diameters, and are rigidly connected--say by belting which neither stretches nor slips--the polishing tool will describe a closed curve. If, however, the belt is arranged to slip slightly, or if the pulleys are of incommensurable diameters, the curve traced out by the grinding tool will be very complex, and in the case of the ratio of the diameters being incommensurable, will always remain open; for polishing purposes the consummation to be wished. Mirror surfaces are ground spherical, the reduction to parabolic form being attained in the process of polishing. A very interesting account of the practice of dealing with very large lenses will be found in Nature, May 1886, or the Journal of the Society of Arts, same date (I presume), by Sir Howard Grubb. The author considers that the final adjustment of surfaces by "figuring"--of which more anon--is an art which cannot be learned by inspection, any more than a man could learn to paint by watching an artist. This is, no doubt, the case to some extent; still, a person wishing to learn how to figure a lens could not do better than take Sir Howard at his word, and spend a month at his works. Meanwhile the following remarks must suffice; it is not likely that anybody to whom these notes will be of service would embark on such large work as is contemplated by Sir Howard Grubb. Fig. 57. Description of Polishing Machine. Power is applied through belting to the speed cone A. By means of a bevel pinion rotation is communicated to the wheel D, which is of solid metal and carries a T-slot, C. A pedestal forming a crank-pin can be clamped so as to have any desired radius of motion by the screw E. A train of wheels E F G H K (ordinary cast lathe change wheels) communicate any desired ratio of motion to the tool-holder, which simply consists of two pins projecting vertically downwards from the spokes of wheel K. These pins form a fork, and each prong engages in a corresponding hole in the back of the slate-grinding tool (not shown in figure). The connection with the tool is purposely loose. The wheel E, of course, cannot rotate about the crank-pin D. Provision for changing the ratio of tool rotation is achieved by mounting the wheels composing the train on pins capable of sliding along a long slot in the bar supporting them. The farther end of this bar is caused to oscillate to and fro very slowly by means of an additional crank-pin S and crank-shaft, the projecting face of the bed-plate W being placed so as to allow V to slide about easily and smoothly. Motion is communicated to this part of the system by means of gears at 0 and P, and a belt working from P to Q. Thus the vertical shaft R is set in motion and communicates by gears with S. A pulley placed on the axle of the wheel carrying the crank-pin S gives a slow rotation to the work which is mounted on the table M. A small but important feature is the tray L below the gear K. This prevents dirt falling from the teeth of the wheel on to the work. The motion of S is of course very much less than of B--say 100 times less. The work can be conveniently adjusted as to height by means of the screw N. The machine must be on a steady foundation, and in a place as free from dust as possible. Though it looks complicated it is quite straight-forward to build and to operate. It is explained in Lord Rayleigh's article on Optics in the Encyclopaedia Britannica that a very minute change in the form of the curvature of the surface of a lens will make a large difference in the spherical aberration. This is to be expected, seeing that spherical aberration is a phenomenon of a differential sort, i.e. a measure of the difference between the curvature actually attained, and the theoretical curvature at each point of the lens, for given positions of point and image. Sir H. Grubb gives an illustration of the minuteness of the abrasion required in passing from a curve of one sort to a curve of another, say from a spherical to a parabolic curve, consequently the process of figuring by the slow action of a polishing tool becomes quite intelligible. In making a large mirror or lens all the processes hitherto described under grinding and polishing, etc, have to be gone through and in the manner described, and when all this is accomplished the final process of correcting to test commences. This process is called figuring. § 67. Of the actual operation of this process I have no personal knowledge, and the following brief notes are drawn from the article by Sir H. Grubb, from my assistant's (Mr. Cook) experience, and from a small work On the Adjustment and Testing of Telescopic Objectives, by T. Cook and Sons, Buckingham Works, York (printed by Ben Johnson and Co, Micklegate, York). This work has excellent photographs of the interference rings of star images corresponding to various defects. It must be understood that the following is a mere sketch. The art will probably hardly ever be required in laboratory practice, and those who wish to construct large telescopes should not be above looking up the references. The process is naturally divided for treatment into two parts. (1) The detection of errors, and the cause of these errors. (2) The application of a remedy. (1) A lens, being mounted with its final adjustments, is turned on to a star, which must not be too bright, and should be fairly overhead. The following appearances may be noted:- A. In focus, the star appears as a small disc with one or two rings round it; inside and outside of the focus the rings increase in number, are round, concentric with the disc, and the bright and dark rings are apparently equally wide. The appearance inside the focus exactly resembles that outside when allowance is made for chromatic effects. Conclusion: objective good, and correctly mounted. B. The rings round the star in focus are not circular, nor is the star at the centre of the system. In bad cases the fringes are seen at one side only. Effects exaggerated outside and inside the focus. Conclusion: the lens is astigmatic, or the objective is not adjusted to be co-axial with the eyepiece. C. When in focus the central disc is surrounded by an intermittent diffraction pattern, i.e. for instance the system of rings may appear along, and near, three or more radii. If these shift when the points of support of the lens are shifted, flexure may be suspected. D. On observing inside and outside the focus, the rings are not equally bright and dark. This may be due to uncorrected spherical aberration, particularly to a fault known as "zonal aberration," where different zones of the lens have different foci, but each zone has a definite focus. E. Irregular diffraction fringes point to bad annealing of the glass. This may be checked by an examination of the lens in polarised light. F. If the disc appear blurred and coloured, however the focus be adjusted, incomplete correction for chromatic aberration is inferred. If in addition the colouring is unsymmetrical (in an extreme case the star disc is drawn out to a coloured band), want of centering is to be inferred. This will also show itself by the interference fringes having the characteristics described in C. (2) The following steps may be taken in applying a remedy: A. The adjusting screws of the cell mounting the object glass may be worked until the best result is attained; this requires great care and patience. Any errors left over are to be attributed to other causes than the want of collinearity of the axes of object glass and eyepiece. B. Astigmatism is detected by rotating the object glass or object glass cell. If the oval fringes still persist and the longer axis follows the lens, astigmatism may be inferred. Similarly, by rotating one lens on the other, astigmatism, or want of centering (quite a different thing) may be localised to the lens. C. The presence of flexure may be confirmed by altering the position of the points of support with respect to the eyepiece, the lens maintaining its original position. The addition of more points of support will in general reduce the ill effects. How to get rid of them I do not know; they are only serious with large lenses. D. Spherical aberration may be located by using stops and zonal screens, and observing the effect on the image. Sir H. Grubb determines whether any point on the lens requires to be raised or lowered, by touching the glass at that point with a warm hand or cooling it by ether. The effects so produced are the differential results of the change of figure and of refractive index. By observing the effect of the heating or cooling of any part, the operator will know whether to raise or lower that part, provided that by a suitable preliminary experiment he has determined the relation between the effect produced by the change of figure, and that due to the temperature variation of the refractive index. In general it is sufficient to consider the change of shape only and neglect the change in refractive power. E. Marked astigmatism has never been noticed by me, but I should think that the whole lens surface would require to be repolished or perhaps reground in this case. F. To decide in which surface faults exist is not easy. By placing a film of oil between the two surfaces nearly in contact these may be easily examined. Thus a mixture of nut and almond oil of the right proportion, to be found by trial, for the temperature, will have the same refractive index as the crown glass, and will consequently reduce any errors of figure in the interior crown surface, if properly applied between the surfaces. Similarly the interior of the flint surface may have its imperfections greatly reduced in effect by using almond oil alone, or mixed with bisulphide of carbon. The outer surfaces, I presume, must be examined by warming or cooling over suitable areas or zones. The defects being detected, a matter requiring a great deal of skill and experience according to Sir H. Grubb, the next step is to remedy them; and the remedial measures as applied to the glass constitute the process of figuring. There are two ways of correcting local defects, one by means of small paper or pitch covered tools, which according to Sir H. Grubb is dangerous, and according to the experience of Mr. Cook, and I think of many French opticians, safe and advantageous. Pitch polishing tools are generally used for figuring. They are made by covering a slate backing with squares of pitch. The backing is floated with pitch say one-eighth of an inch thick. This is then scored into squares by a hot iron rod. The tool, while slightly warm, is laid upon the lens surface, previously slightly smeared with dilute glycerine, until the pitch takes the figure of the glass. The polishing material is rouge and water. Small tools are applied locally, and probably can only be so applied with advantage for grave defects. The other method is longer and probably safer. It consists in furnishing the polishing tool with squares of pitch as before. These being slightly warm, the lens is placed upon them so that they will flow to the exact figure also as before. I presume that the lens is to be slightly smeared with glycerine, or some equivalent, to keep the pitch from sticking. The squares are most thickly distributed where the abrasion is most required, i.e. less pitch is melted out by the iron rod. This may be supplemented by taking advantage of differences of hardness of pitch, making some squares out of harder, others out of softer pitch. The aim is to produce a polishing tool which will polish unequally so as to remove the glass chiefly from predetermined parts of the lens surface. The tool is worked over the surface of the lens by the polishing machine, and part of the art consists in adjusting the strokes to assist in the production of the local variations required. A source of difficulty and danger lies in the fact that the pitch squares are rarely of the same hardness, so that some abrade the glass more rapidly than others. This is particularly likely to occur if the pitch has been overheated. [Footnote: When pitch is heated till it evolves bubbles of gas its hardness increases with the duration of the process.] The reader must be good enough to regard these remarks as of the barest possible kind, and not intended to convey more than a general idea of the nature of the process of figuring. § 68. A few remarks on cleaning lenses will fittingly close this part of the subject. There is no need to go beyond the following instructions given by Mr. Brashear in Popular Astronomy, 1894, which are reproduced here verbatim. "The writer does not advise the use of either fine chamois skin, tissue paper, or an old soft silk handkerchief, nor any other such material to wipe the lenses, as is usually advised. It is not, however, these wiping materials that do the mischief, but the dust particles on the lenses, many of them perhaps of a silicious nature, which are always harder than optical glass, and as these particles attach themselves to the wiping material they cut microscopic or greater scratches on the surfaces of the objective in the process of wiping. "I write this article with the hope of helping to solve this apparently difficult problem, but which in reality is a very simple one. "Let us commence by taking the object glass out of its cell. Take out the screws that hold the ring in place, and lift out the ring. Placing the fingers of both hands so as to grasp the objective on opposite sides, reverse the cell, and with the thumbs gently press the objective squarely out of the cell on to a book, block of wood, or anything a little less in diameter than the objective, which has had a cushion of muslin or any soft substance laid upon it. One person can thus handle any objective up to 12 inches in diameter. "Before separating the lenses it should be carefully noted how they were put together with relation to the cell, and to one another, and if they art not marked they should be marked on the edges conspicuously with a hard lead pencil, so that when separated they may be put together in the same way, and placed in the same relation to the cell. With only ordinary precaution this should be an easy matter. "Setting the objective on edge the two lenses may be readily separated. "And now as to the cleaning of the lenses. I have, on rare occasions, found the inner surfaces of an object glass covered with a curious film, not caused directly by moisture but by the apparent oxidation of the tin-foil used to keep the lenses apart. "A year or more ago a 7-inch objective made by Mr. Clark was brought to me to clean. It had evidently been sadly neglected. The inside of the lenses were covered with such a film as I have mentioned, and I feared the glass was ruined. When taken apart it was found that the tin-foil had oxidised totally and had distributed itself all over the inner surfaces. I feared the result, but was delighted to find that nitric acid and a tuft of absorbent cotton cut all the deposit off, leaving no stains after having passed through a subsequent washing with soap and water. "I mention this as others may have a similar case to deal with. "For the ordinary cleaning of an objective let a suitable sized vessel, always a wooden one, be thoroughly cleaned with soap and water, then half filled with clean water about the same temperature as the glass. Slight differences of temperature are of no moment. Great differences are dangerous in large objectives. "I usually put a teaspoonful of ammonia in half a pail of water, and it is well to let a piece of washed 'cheese cloth' lie in the pail, as then there is no danger if the lens slips away from the hand, and, by the way, every observatory, indeed every amateur owning a telescope, should have plenty of 'cheese cloth' handy. It is cheap (about 3 cts. per yard) and is superior for wiping purposes to any 'old soft silk handkerchief,' chamois skin, etc. Before using it have it thoroughly washed with soap and water, then rinsed in clean water, dried and laid away in a box or other place where it can be kept clean. When you use a piece to clean an objective throw it away, it is so cheap you can afford to do so. "If the lenses are very dirty or 'dusty,' a tuft of cotton or a camel's-hair brush may be used to brush off the loose material before placing the lenses in the water, but no pressure other than the weight of the cotton or brush should be used. The writer prefers to use the palms of the hand with plenty of good soap on them to rub the surfaces, although the cheese cloth and the soap answers nicely, and there seems to be absolutely no danger of scratching when using the hands or the cheese cloth when plenty of water is used; indeed when I wish to wipe off the front surface of an objective in use, and the lens cannot well be taken out, I first dust off the gross particles and then use the cheese cloth with soap and water, and having gone over the surface gently with one piece of cloth, throw it away and take another, perhaps a third one, and then when the dirt is, as it were, all lifted up from the surface, a piece of dry cheese cloth will finish the work, leaving a clean brilliant surface, and no scratches of any kind. "In washing large objectives in water I generally use a 'tub' and stand the lenses on their edge. When thoroughly washed they are taken out and laid on a bundle of cheese cloth and several pieces of the same used to dry them. "I think it best not to leave them to drain dry; better take up all moisture with the cloth, and vigorous rubbing will do no harm if the surfaces have no abrading material on them. I have yet to injure a glass cleaned in this way. "This process may seem a rather long and tedious one, but it is not so in practice, and it pays. "In some places objectives must be frequently cleaned, not only because they become covered with an adherent dust, but because that dust produces so much diffused light in the field as to ruin some kinds of telescope work. Mr. Hale of the Kenwood Observatory tells me he cannot do any good prominence photography unless his objective has a clean surface; indeed every observer of faint objects or delicate planetary markings knows full well the value of a dark field free from diffused light. The object-glass maker uses his best efforts to produce the most perfect polish on his lenses, aside from the accuracy of the curves, both for high light value and freedom from diffused light in the field, and if the surfaces are allowed to become covered with dust, his good work counts for little. "If only the front surface needs cleaning, the method of cleaning with cheese cloth, soap and water, as described above, answers very well, but always throw away the first and, if necessary, the second cloth, then wipe dry with a third or fourth cloth; but if the surfaces all need cleaning I know of no better method than that of taking the objective out of its cell, always using abundance of soap and water, and keep in a good humor." § 69. The Preparation of Flat Surfaces of Rock Salt. The preliminary grinding is accomplished as in the case of glass, except that it goes on vastly faster. The polishing process is the only part of the operation which presents any difficulty. The following is an extract from a paper on the subject, by Mr. J. A. Brashear, Pittsburg, Pa, U.S.A, from the Proceedings of the American Association for the Advancement of Science, 1885. Practically the same method was shown me by Mr. Cook some years earlier, so that I can endorse all that Mr. Brashear says, with the following exceptions. We consider that for small salt surfaces the pitch is better scored into squares than provided with the holes recommended by Mr. Brashear. Mr. Brashear's instructions are as follows. After alluding to the difficulty of drying the polished salt surface--which is of course wet--Mr. Brashear says:- "Happily I have no trouble in this respect now, and as my method is easily carried out by any physicist who desires to work with rock salt surfaces, it gives me pleasure to explain it. For polishing a prism I make an ordinary pitch bed of about two and one-half or three times the area of the surface of the prism to be polished. While the pitch is still warm I press upon it any approximately flat surface, such as a piece of ordinary plate glass. The pitch bed is then cooled by a stream of water, and conical holes are then drilled in the pitch with an ordinary counter sink bit, say one-quarter of an inch in diameter, and at intervals of half an inch over the entire surface. This is done to relieve the atmospheric pressure in the final work. The upper surface of the pitch is now very slightly warmed and a true plane surface (usually a glass one, prepared by grinding and polishing three surfaces in the ordinary way, previously wetted) is pressed upon it until the pitch surface becomes an approximately true plane itself. Fortunately, moderately hard pitch retains its figure quite persistently through short periods and small changes of temperature, and it always pays to spend a little time in the preparation of the pitch bed. "The polisher being now ready, a very small quantity of rouge and water is taken upon a fine sponge and equally distributed over its surface. The previously ground and fined salt surface (this work is done the same as in glass working) is now placed upon the polisher and motion instantly set up in diametral strokes. I usually walk around the polisher while working a surface. It is well to note that motion must be constant, for a moment's rest is fatal to good results, for the reason that the surface is quickly eaten away, and irregularly so, owing to the holes that are in the pitch bed. Now comes the most important part of this method. After a few minutes' work the moisture will begin to evaporate quite rapidly. No new application of water is to be made, but a careful watch must be kept upon the pitch bed, and as the last vestige of moisture disappears the prism is to be slipped off the polisher in a perfectly horizontal direction, and if the work has been well done, a clean, bright, and dry surface is the result. The surface is now tested by the well-known method of interference from a perfect glass test plate (see Fig. 178). "If an error of concavity presents itself the process of polishing is gone over again, using short diametral strokes. If the error is one of convexity, the polishing strokes are to be made along the chords, extending over the edge of the polisher. The one essential feature of this method is the fact that the surface is wiped dry in the final strokes, thus getting rid of the one great difficulty of pitch polishing, a method undoubtedly far superior to that of polishing on broadcloth. If in the final strokes the surface is not quite cleaned I usually breathe upon the pitch bed, and thus by condensation place enough moisture upon it to give a few more strokes, finishing just the same as before. In ten minutes I have polished prisms of rock salt in this manner that have not only shown the D line double, but Professor Langley has informed me that his assistant, Mr. Keeler (J. E.), has seen the nickel line clearly between the D lines. This speaks for the superiority of the surfaces over those polished on broadcloth. "In polishing prisms I prefer to work them on top of the polisher, as they can be easily held, but as it is difficult to hold lenses or planes in this way without injuring the surfaces, I usually support them in a block of soft wood, turned so as to touch only at their edges, and work the polisher over them. Though it takes considerable practice to succeed at first, the results are so good that it well repays the few hours' work it requires to master the few difficulties it presents." Fig. 58. § 70. Casting Specula for Mirrors. According to Sir H. Grubb (loc. cit.) the best alloy is made of four atoms of copper and one of tin; this gives by weight, copper 252, tin 117.8. The copper is melted first in a plumbago crucible; the tin is added gradually. Of course, in the process of melting, even though a little fine charcoal be sprinkled over the copper, some loss of that metal will occur from oxidation. It is convenient in practice, therefore to reserve a portion of the tin and test the contents of the crucible by lifting a little of the alloy out and examining it. The following indications may be noted: When the copper is in excess the tint of the alloy is slightly red, and the structure, as shown at a fractured surface, is coarsely crystalline. As the proper proportions are more nearly attained, the crystalline structure becomes finer, the colour whiter, and the crystals brighter. The alloy is ready for use when the maximum brightness is attained and the grain is fine. If too much tin be added, the lustre diminishes. The correct proportion is, therefore, attained when a further small addition of tin produces no apparent increase of brightness or fineness of grain. About three-quarters of the tin may be added at first, and the other quarter added with testing as described. The alloy is allowed to cool until on skimming the surface the metal appears bright and remains so without losing its lustre by oxidation for a sensible time; it will still be quite red-hot. Fig. 59. Fig. 60. As the speculum alloy is too difficult to work with ordinary tools, it is best to cast the speculum of exactly the required shape and size. This is done by means of a ring of iron turned inside (and out) and on one edge. This ring is laid on a plate of figured iron, and before the metal is poured the plate (G) (Figs 59 and 61) is heated to, say, 300° C. In order to avoid the presence of oxide as far as possible, the following arrangements for pouring are made. A portion of the lower surface of the ring is removed by radial filing until a notch equal to, say, one-twentieth of the whole circumference is produced. This is cut to an axial depth of, say, half an inch. A bar of iron is then dovetailed loosely into the notch (Fig. 60, B), so that it will rest on the iron plate, and half fill the notch. The aperture thus left forms the port of ingress for the hot metal (see Fig. 61, M). A bit of sheet iron is attached to the upper surface of the ring, and lies as a sort of flap, shaped like a deep shovel, against the outside of the ring overhanging the port (Figs. 59 and 61 at F). This flap does not quite reach the iron plate, and its sides are bent so as to be in contact with the ring. A portion of a smaller ring is then applied in such a manner as to form a pouring lip or pool on the outside of the main ring at E, and the metal can only get into the main ring by passing under the edge of the flap and up through the port. This forms an efficient skimming arrangement. The process of casting is carried out by pouring steadily into the lip. To avoid air bubbles it is convenient to cause the metal to spread slowly over the chill, and Mr. Nasmyth's method of accomplishing this is shown in the figure (61). The chill rests on three pins, A B C (Figs. 59 and 61). Before pouring begins the chill is tilted up off C by means of the counterpoise D, which is insufficient to tilt it after the speculum is poured. It is important that the chill should be horizontal at the close of the operation, in order that the speculum may be of even thickness throughout. This is noted by means of levels placed on the ring (at K for instance). Fig. 61. This apparatus may appear unnecessarily complex, but it is worth while to set it up, for it makes the operation of casting a speculum fairly certain. If the metal is at the right temperature it will form a uniformly liquid disc inside the ring. The mass sets almost directly, and as soon as this occurs it is pushed to the edge of the plate and the metal in the lip broken off by a smart upward tap with a hammer. The dovetailed bit of iron is knocked downwards and falls off, and the ring may then be lifted clear of the casting. The object of the dovetail will now be understood, for without it there is great risk of breaking into the speculum in knocking the "tail" off. A box of quite dry sawdust is prepared in readiness for the process of annealing before the speculum is cast. The box must be a sound wooden or metal box, and must be approximately air-tight. For a speculum a foot in diameter the box must measure at least 3 feet both ways in plan, and be 2 feet 6 inches deep. Half the sawdust is in the box and is well pressed down so as to half fill it. The other half must be conveniently ready to hand. As soon as possible after casting, the speculum is thrown into the box, covered over with the sawdust, and the lid is put on. The object in having the box nearly air-tight is to avoid air-currents, which would increase the rate of cooling. A speculum a foot in diameter may conveniently take about three days to anneal, and should be sensibly warm when the box is opened on the fourth day. For larger sizes longer times will be required. We will say that the sawdust thickness on each side must be proportional to the dimensions of the speculum, or may even increase faster with advantage if time is of no moment. The process of annealing may be considered successful if the disc does not fly to pieces in working; it is to be worked on the chilled side. The object of giving the chill the approximate counterpart form will now appear; it saves some rough grinding, and causes the finished surface to be more homogeneous than it would be if the centre were sunk by grinding through the chilled surface. In 1889 I learned from Mr. Schneider, Professor Row-land's assistant at Baltimore, that in casting specula for concave gratings a good deal of trouble had been saved by carrying out the operation in an atmosphere consisting mostly of coal gas. It was claimed that in this way the presence of specks of oxide was avoided. I did not see the process in operation, but the results attained are known and admired by all experimenters. § 71. Grinding and polishing Specula. The rough grinding is accomplished by means of a lead tool and coarse emery; the size of grain may be such as will pass a sieve of 60 threads to the inch. The process of grinding is quite similar to that previously described, but it goes on comparatively quickly. The rough grinding is checked by the spherometer, and is interrupted when that instrument gives accordant and correct measurements all over the surface. The fine grinding may be proceeded with by means of a glass-faced tool as before described, or the labour may be reduced in the following manner. A slate tool, which must be free from green spots (a source of uneven hardness), is prepared, and this is brought nearly to the curvature of the roughly ground speculum, by turning or otherwise. It is finished on the speculum itself with a little flour of emery. The fine grinding is then carried on by means of slate dust and water, the slate tool being the grinder. The tool is, of course, scored into squares on the surface. If the casting process has been carried out successfully, the rough grinding may take, say six hours, and the fine grinding say thirty hours for a disc a foot in diameter. The greatest source of trouble is want of homogeneity in the casting, as evidenced by blowholes, etc. In general, the shortest way is to discard the disc and start afresh if there is any serious want of perfection in the continuity or homogeneity of the metal. Fig. 62. The finely ground surface must, of course, be apparently correct in so far as a spherometer (with 3 inches between the legs for a disc 1 foot in diameter) will show. Polishing and figuring are carried out simultaneously. Half an hour's polishing with a slate-backed pitch tool and rouge and water will enable an optical test to be made. The most convenient test is that of Foucault, a simple appliance for the purpose being shown in the figure (62). It essentially consists of a small lamp surrounded by an opaque chimney (A) through which a minute aperture (pin-hole) is made. A small lens may be used, of very great curvature, or even a transparent marble to throw an image of the flame on the pin-hole. A screen (B) is placed close to the source, and is provided with a rocking or tilting motion (C) in its own plane. The source and screen are partly independent, and each is provided with a fine adjustment which serves to place it in position near the centre of curvature. The screen is so close to the pin-hole in fact that both the source and a point on the edge of the screen may be said to be at the centre of curvature of the mirror. The mirror is temporarily mounted so as to have its axis horizontal, in a cellar or other place of uniform temperature. The final focussing to the centre of curvature is made by the fine adjustment screws; the image may be received on a bit of paper placed on the screen and overlapping the edge nearest the source. The screws are worked till the image has its smallest dimension and is bisected by the edge of the screen. The test consists in observing the appearance of the mirror surface while the screen is tilted to cut off the light, as seen by an eye placed at the edge of the screen, a peephole or eye lens being provided to facilitate placing the eye in a correct position. The screen screws are worked so as to gradually cut off the light, and the observer notes the appearance of the mirror surface. If the curves are perfect and spherical, the transition from complete illumination to darkness will be abrupt, and no part of the mirror will remain illuminated after the rest. For astronomical purposes a parabolic mirror is required. In this case the disc may be partially screened by zonal screens, and the position of the image for different zones noted; the correctness or otherwise of the curvature may then be ascertained by calculation. A shorter way is to place the source just outside the focus, to be found by trial, and then, moving the extinction screen (now a separate appliance) to, say, five times the radius of curvature away, where the image should now appear, the suddenness of extinction may be investigated. This, of course, involves a corresponding modification of the apparatus. Whether the tests indicate that a deepening of the Centre, i.e. increase of the curvature, or a flattening of the edges is required, at least two remedial processes are available. The "chisel and mallet" method of altering the size of the pitch, squares of the polisher may be employed, or paper or small pitch tools may be used to deepen the centre. The "chisel and mallet" method merely consists in removing pitch squares from a uniformly divided tool surface by means of the instruments mentioned. This removal is effected at those points at which the abrasion requires to be reduced. When some practice is attained, I understand that it is usual to try for a parabolic form at once, as soon as the polishing commences. This is done by dividing the pitch surface by V-shaped grooves, the sides of the grooves being radii of the circular surface, so that the central parts of the mirror get most of the polishing action. If paper tools are used they must not be allowed much overhang, or the edges of the mirror betray the effects of paper elasticity. Most operators "sink" the middle, but the late Mr. Lassell, a most accomplished worker, always attained the parabolic form by reducing the curvature of the edges of a spherical mirror. § 72. Preparation of Flat Surfaces. As Sir H. Grubb has pointed out, this operation only differs from those previously described in that an additional condition has to be satisfied. This condition refers to the mean curvature, which must be exact (in the case of flats it is of course zero) to a degree which is quite unnecessary in the manufacture of mirrors or lenses. A little consideration will show that to get a surface flat the most straightforward method is to carry out the necessary and sufficient condition for three surfaces to fit each other impartially. If they each fit each other, they must clearly all be flat. To carry out the process of producing a flat surface, therefore, two tools are made, and the glass or speculum is ground first on one and then on the other, the tools being kept "in fit" by occasional mutual grinding. The grinding and polishing go on as usual. If paper is employed, care must be taken that the polisher is about the same size as the object to be polished. There is a slight tendency to polish most at the edges; but if the sweeps are of the right shape and size, this may be corrected approximately. The best surfaces which have come under my notice are those prepared as "test surfaces" by Mr. Brashear of Alleghany, Pa, U.S.A. These I believe to be pitch polished. A pitch bed is prepared, I presume, in a manner similar to that described for rocksalt surfaces; but the working of the glass is an immense art, and one which I believe--if one may judge by results--is only known to Mr. Brashear. In general, the effect of polishing will be to produce a convex or concave surface, quite good enough for most purposes, but distinctly faulty when tested by the interference fringes produced with the aid of the test plate. The following information therefore--which I draw from Mr. 'Cook--will not enable a student to emulate Mr. Brashear, but will undoubtedly help him to get a very much better surface than he usually buys at a high price, as exhibited on a spectroscope prism. The only difference between this process and the one described for polishing lenses, lies in the fact that the rouge is put into the paper surface while the latter is wet with a dilute gum "mucilage." It is of course assumed that the object and the two tools have been finely ground and fit each other impartially. The paper is rubbed over with rouge and weak gum water. The tool, when dry, is applied to the flat ground surface (of the object), and is scraped with the three-cornered file chisel as formerly described. This process must be very carefully carried out. The paper must be of the quality mentioned, or may even be thinner and harder. The cross strokes should be more employed than in the case of the curved surfaces. A good deal will depend on the method employed for supporting the work; it is in general better to support the tool, which may have a slate backing of any desired thickness, whereby the difficulty resulting from strains is reduced. The work must be mounted in such a way as to minimise the effect of changes of temperature. If a pitch bed is selected, Mr. Brashear's instructions for rock salt may be followed, with, of course, the obvious necessary modifications. See also next section. § 73. Polishing Flat Surfaces on Glass or on Speculum Metal. The above process may be employed for speculum metal, or pitch may be used. In the latter case a fresh tool must be prepared every hour or so, because the metal begins to strip and leave bits on the polisher; this causes a certain amount of scratching to take place. As against this disadvantage, the process of polishing, in so far as the state of the surface is concerned, need not take an hour if the fine grinding has been well done. For the finest work changes of temperature, as in the case of glass, cause a good deal of trouble, and the operator must try to arrange his method of holding the object so as to give rise to the least possible communication of heat from the hand. The partial elasticity of paper, which is its defect as a polishing backing, is, I believe, partly counterbalanced by the difficulty of forming with pitch an exact counterpart tool without introducing a serious rise of temperature (i.e. warming the pitch). The rate of subsidence of the latter is very slow at temperatures where it is hard enough to work reliably as a polisher. A student interested in the matter of flat surfaces will do well to read an account of Lord Rayleigh's work on the subject, Nature, vol. xlviii, 1893, pp. 212, 526 (or B. A. Reports, 1893). In the first of these communications Lord Rayleigh describes the method of using test plates, and shows how to obtain the interference fringes in the clearest manner. For the ordinary optician a dark room and a soda flame afford all requisite information; and if a person succeeds in making three glass discs, say 6 inches in diameter, so flat that, when superposed in any manner, the interference fringes are parallel and equidistant, even to the roughest observation, he has nothing to learn from any book ever written on glass polishing. Lord Rayleigh has also shown how to use the free clean surface of water as a natural test plate. Since the above was written the following details of his exact course of procedure have been sent to me by Mr. Brashear, and I hereby tender my thanks:- "It really takes years to know just what to do when you reach that point where another touch either gives you the most perfect results attainable, or ruins the work you have already done. It has taken us a long time to find out how to make a flat surface, and when we were called upon to make the twenty-eight plane and parallel surfaces for the investigation of the value of the metre of the international standard, every one of which required an accuracy of one-twentieth of a wave length, we had a difficult task to perform. However, it was found that every surface had the desired accuracy, and some of them went far beyond it. It is an advantage in making flat surfaces to make more than one at a time; it is better to make at least three, and in fact we always grind and 'fine' three together. In making speculum plates we get up ten or twelve at once on the lead lap. These speculum plates we can test as we go on by means of our test plane until we get them nearly flat. In polishing them we first make quite a hard polisher, forming it on a large test plane that is very nearly correct. We then polish a while on one surface and test it, then on a second and test it, and after a while we accumulate plates that are slightly concave and slightly convex. By working upon these alternately with the same polisher, we finally get our polisher into such shape that it approximates more and more to a flat surface, and with extreme care and slow procedure we finally attain the results desired. All our flats are polished on a machine which has but little virtue in itself, unmixed with brains. Any machine giving a straight diametrical stroke will answer the purpose. The glass should be mounted so as to be perfectly free to move in every direction--that is to say, perfectly unconstrained. We mount all our flats on a piece of body Brussels carpet, so that every individual part of the woof acts as a yielding spring. The flats are held in place by wooden clamps at the edges, which never touch, but allow the bits of glass or metal to move slowly around if they are circular; if they are rectangular we allow them to tumble about as they please within the frame holding them. For making speculum metal plates either plane or concave we use polishers so hard that they scratch the metal all over the surface with fine microscopic scratches. We always work for figure, and when we get a hard polisher that is in proper shape, we can do ever so many surfaces with it if the environments of temperature are all right. If we have fifty speculum flats to make, and we recently made three times that number, we get them all ready and of accurate surface with the hard polisher. Then we prepare a very soft polisher, easily indented when cold with the thumb nail. A drop of rouge and about three drops of water are put on the plate, and with the soft polisher about one minute suffices to clean up all the scratches and leave a beautiful black polish on the metal. This final touch is given by hand; if we do not get the polish in a few minutes the surface is generally ruined for shape, and we have to resort to the hard polisher again. I assure you that nothing but patience and perseverance will master the difficulty that one has to encounter, but with these two elements 'you are bound to get there.'" CHAPTER III MISCELLANEOUS PROCESSES § 74. Coating Glass with Aluminium and Soldering Aluminium. A process of coating glass with aluminium has been lately discovered, which, if I mistake not, may be of immense service in special cases where a strongly adherent deposit is required. My attention was first attracted to the matter by an article in the Archives des Sciences physiques et naturelles de Genève, 1894, by M. Margot. It appears that clean aluminium used as a pencil will leave a mark on clean damp glass. If, instead of a pencil, a small wheel of aluminium--say as big as a halfpenny and three times as thick--is rotated on the lathe, and a piece of glass pressed against it, the aluminium will form an adherent, though not very continuous coating on the glass. Working with a disc of the size described rotating about as fast as for brass-turning, I covered about two square inches of glass surface in about five minutes. The deposit was of very uneven thickness, but was nearly all thick enough to be sensibly opaque. By burnishing the brilliance is improved (I used an agate burnisher and oil), but a little of the aluminium is rubbed off. The fact that the burnisher does not entirely remove it is a sign of the strength of the adherence which exists between the aluminium and the glass. In making the experiment, care must be taken to have the glass quite clean--or at all events free from grease--in order to obtain the best results. M. Margot has contributed further information to the Archives des Sciences physiques et naturelles (February 1895). He finds that adherence between aluminium and glass is promoted by dusting the glass with powders, such as rouge. There is no doubt that a considerable improvement is effected in this way; both rouge and alumina have in my hands greatly increased the facility with which the aluminium is deposited. M. Margot finds that zinc and magnesium resemble aluminium in having properties of adherence to glass, and, what is more, carry this property into their alloys with tin. Thus an alloy of zinc and tin in the proportions of about 92 per cent tin and 8 per cent zinc may be melted on absolutely clean glass, and will adhere strongly to it if well rubbed by an asbestos crayon. A happy inspiration was to try whether these alloys would, under similar circumstances, adhere to aluminium itself, and a trial showed that this was indeed the case, provided that both the aluminium and alloy are scrupulously clean and free from oxide. In this way M. Margot has solved the problem of soldering aluminium. I have satisfied myself by trial of the perfect ease and absolute success of this method. The alloy of zinc and tin in the proportions above mentioned is formed at the lowest possible temperature by melting the constituents together. It is then poured so as to form thin sticks. The aluminium is carefully cleaned by rubbing with a cuttle bone, or fine sand, and strong warm potash. It is then washed in water and dried with a clean cloth. The aluminium is now held over a clean flame and heated till it will melt the solder which is rubbed against it. The solder sticks at once, especially if rubbed with another bit of aluminium (an aluminium soldering bit) similarly coated. To solder two bits of aluminium together it is only necessary to tin the bits by this process and then sweat them together. The same process applies perfectly to aluminium caused to adhere to glass by the previously mentioned process, and enables strong soldered contacts to be made to glass. In one case, while I was testing the method, the adhesion was so strong that the solder on contracting while cooling actually chipped the surface clean off the glass. In order to get over this I have endeavoured to soften the solder by mixing in a little of the fusible metal mercury amalgam; and though this prevents the glass from being so much strained, it reduces the adherence of the solder. It is a comfort to be able to solder aluminium after working for so many years by way of electroplating, or filing under solder. An alternative method of soldering aluminium will be described when the electroplating of aluminium is discussed, § 138. Gilding Glass. In looking over some volumes of the Journal fuer praktische Chemie, I came across a method of gilding glass due to Boettger (Journ. f. prakt. Chem. 103, p. 414). After many trials I believe I am in a position to give definite instructions as to the best way of carrying out this rather troublesome operation. The films of gold obtained by the process are very thick, and the appearance of the gold exceedingly fine. The difficulty lies in the exact apportionment of the reducing solution. If too much of the reducing solution be added, the gold deposits in a fine mud, and no coating is obtained. If, on the other hand, too little of the reducing solution be added, little or no gold is deposited. The secret of success turns on exactly hitting the proper proportions. The reducing solution consists of a mixture of aldehyde and glucose, and the difficulty I have had in following Boettger's instructions arose from his specifying "commercial aldehyde" of a certain specific gravity which it was impossible to reproduce. I did not wish to specify pure aldehyde, which is not very easily got or stored, and consequently I have had to determine a criterion as to when the proportion of reducing solution is properly adjusted. The aldehyde is best made as required. I employed the ordinary process as described in Thorpe's Dictionary of Applied Chemistry, by distilling alcohol, water, sulphuric acid, and manganese dioxide together. The crude product is mixed with a large quantity of calcium chloride (dry--not fused), and is rectified once. The process is stopped when the specific gravity of the product reaches 0.832 at 60° F. The specific gravity of pure aldehyde is 0.79 nearly. The following is a modification of Boettger's formula:- Solution I 1 gram of pure gold is converted into chloride--got acid free--i.e. to the state represented by AuCl3, and dissolved in 120 cc. of water. This solution is the equivalent of one containing 6.5 grains of trichloride to the ounce of water. Solution II. 6 grams sodium hydrate. 100 grams water. Solution III. 0.2 grams glucose (bought as pure). 12.6 cubic centimetres 95 per cent alcohol. 12.6 cubic centimetres water. 2.0 cubic centimetres aldehyde, sp. gr. 0.832. To gild glass these solutions are used in the following proportions by volume:- 16 parts of No. I. 4 parts of No. II. 0.8 parts of No. III. The glass is first cleaned well with acid and washed with water: it is then rinsed with Solution No. III. If it is desired to gild the inside of a glass vessel, Solution No. III. may be placed in the vessel first, and the walls of the vessel rinsed round carefully. Solutions I. and II. are mixed separately and then added to III.--after about two minutes the whole is well shaken up. If it be desired to gild a mirror of glass, the glass-plate is suspended face downwards in a dish of the mixed solutions--care being taken to rinse the glass with Solution III. first. If the mixture darkens in from 7' to 10' in diffuse daylight and at 60°F. it will gild well, and it generally pays to make a few trials in a test tube to arrive at this. If too much reducing solution is present the liquid will get dark more rapidly, and vice versa. The gilding will require several hours--as much as twelve hours may be needed. The reaction is one of great chemical interest, being one of that class of reactions which is greatly affected by capillarity. Thus it occasionally happens that when the reducing solution is not in the right proportion, gold will be deposited at the surface of the liquid (so as to form a gilt ring on the inside of a test tube), the remainder of the gold going down as mud. The gold deposited is at first transparent to transmitted light and is deeply blue. I thought this might be due to a trace of copper or silver, but on carefully purifying the gold no change of colour was noted. If the reducing solution is present in slightly greater proportions than that given in the formula, the gold comes down with a richer colour, and has a tendency to form a mat surface and to separate from the glass. The gold which is deposited more slowly has a less rich colour but a brighter surface. The operation should be interrupted when a sufficient deposit has been obtained, because it is found that the thicker the deposit, the more lightly is it held to the glass surface. § 75. The Use of the Diamond-cutting Wheel. A matter which is not very well known outside geological circles is the manipulation of the diamond-cutting wheel, and as this is often of great use in the physical laboratory, the following notes may not be out of place. I first became acquainted with the art in connection with the necessity which arose for me to make galvanometer mirrors out of fused quartz, and it was then that I discovered with surprise how difficult it is to obtain information on the point. I desire to express my indebtedness to my colleagues, Professor David and Mr. Smeeth, for the instruction they have given me. In what follows I propose to describe their practice rather than my own, which has been of a makeshift description. I will therefore select the process of cutting a slice of rock for microscopical investigation. § 76. Arming a Wheel. Fig. 63. A convenient wheel is made out of tin-plate, i.e. mild steel sheet, about one-thirtieth of an inch thick and seven inches in diameter. This wheel must be quite flat and true, as well as round; too much pains cannot be taken in securing these qualities. After the wheel is mounted, it is better to turn it quite true by means of a watch-maker's "graver" or other suitable tool. The general design of a rock-cutting machine will be clear from the illustration (Fig. 63). The wheel being set up correctly, the next step is to arm it with diamond dust. For this purpose it is before all things necessary that real diamond dust should be obtained. The best plan is to procure a bit of "bort" which has been used in a diamond drill, and whose properties have therefore been tested to some extent. This is ground in a diamond mortar--or rather hammered in one--and passed through a sieve having at least 80 threads to the inch. The dust may be conveniently kept in oil. To arm the wheel, a little dust and oil is taken on the finger, and laid on round the periphery of the wheel. A bit of flint or agate is then held firmly against the edge of the wheel and the latter is rotated two or three times by hand. The rotation must be quite slow--say one turn in half a minute--and the flint must be held firmly and steadily against the wheel. Some operators prefer to hammer the diamond dust into the wheel with a lump of flint, or agate, but there is a risk of deforming the wheel in the process. When a new wheel is set up, it may be necessary to repeat the above process once every half hour or so till the cutting is satisfactory, but when once a wheel is well armed it will work for a long time without further attention. § 77. Cutting a Section. A wheel 7 inches in diameter may be rotated about 500 times per minute, and will give good results at that speed. The work, as will be seen from the diagram, is pressed against the edge of the wheel by a force, which in the case quoted was about the weight of eleven ounces. This was distributed along a cutting arc of three-quarters of an inch. A convenient cutting lubricant is a solution of Castile soap in water, and this must be freely supplied; if the wheel gets dry it is almost immediately spoiled owing to the diamond dust being scraped off. In the figure the lubricant is supplied by a wick running into the reservoir. I have used both clock oil and ordinary gas-engine oil as lubricants, with equally satisfactory results. As to the speed of cutting, in the experiment quoted a bit of rather friable "gabbro," measuring three-quarters of an inch on the face by five-eighths of an inch thick, was cut clean through in six minutes, or by 3000 turns of the wheel. The travel of the edge was thus between 5000 and 6000 feet, or say 9000 feet, nearly 2 miles, per inch cut. A good solid rock, like basalt, can be cut into slices of about 3/32 inch thick. A very loose rock is best boiled in Canada balsam, hard enough to set, before it is put against the wheel. Instead of a grinding machine a lathe may be employed. The disc is, of course, mounted on the mandrel, and the work on the slide-rest. The latter must be disconnected from its feed screws, and a weight arranged over a pulley so as to keep the work pressed against the wheel by a constant force. It may, perhaps, occur to the reader to inquire whether any clearance in the cut is necessary. The answer is that in all probability, and in spite of every care, the wheel will wobble enough to give clearance. If it does not, a little diamond dust rubbed into the side of the wheel, as well as the edge, will do all that is required. The edge also, after two or three armings, "burrs" a little, and thus provides a clearance naturally. It is not unlikely that in the near future the electric furnace will furnish us with a number of products capable of replacing the diamond as abrading agents. The cost of the small amount of diamond dust; required in a laboratory is so small, however, that it; is doubtful whether any appreciable economy will be, effected. § 78. Grinding Rock Sections, or Thin Slips of any Hard Material. A note on this is, perhaps, worth making, for the same reasons as were given for note, § 75, which it naturally follows. Just as trout-fishing; is described by Mr. Francis as the "art of fine and far off," [Footnote: In the Badminton Library, volume on Fishing.] section grinding may be called "the art of Canada balsam cooking," as follows. A section of rock having been cut from the lump as just described, it becomes; necessary to grind it down for purposes of microscopical investigation. For this purpose it is placed on a slip of glass, and cemented in position by Canada, balsam. Success in the operation of grinding the mounted section depends almost entirely on the way in which the mounting is done, and this in its turn depends on the condition to which the Canada has been brought. To illustrate the operations, I will describe a specific case, viz. that of grinding the section of "gabbro"' above described, for microscopical purposes. One side of the section is probably sufficiently smooth and plane from the operation of the diamond wheel; if not, it must be ground by the finger on a slab of iron or gun-metal with emery and water, the emery passing a sieve of 80 threads to the inch. The glass base on which the section is to be mounted for grinding is placed on a bit of iron or copper plate over a Bunsen burner, and three or four drops of natural Canada balsam are placed upon it. The section is placed on the plate to heat at the same time. The temperature must not rise so high as to cause any visible change in the Canada balsam, except a slight formation of bubbles, which rise to the surface, and can be blown off. The heating may require to be continued, say, up to twenty minutes. The progress of the operation is tested by examining the balsam as to its viscous properties. An exceedingly simple and accurate way of testing is to dip a pair of ordinary forceps in the balsam, which may be stirred a little to secure uniformity. The forceps are introduced with the jaws in contact, and, as soon as withdrawn, the jaws are allowed to spring apart, thus drawing out a balsam thread. In a few moments the thread is cold, and if the forceps be compressed, this thread will bend. The Canada must be heated until it is just in such a state that on bringing the jaws together the thread breaks. The forceps may open to about three-quarters of an inch. If the Canada is more viscous, so that the thread does not break, the section when cemented by it will most probably slip on the slide. On the other hand, if the balsam is more brittle, it will crumble away during the grinding. Assuming that the proper point has been reached, the section is mounted with the usual precautions to avoid air bubbles, i.e. by dropping one edge on the balsam first. When all is cold, the surface of the section may be ground on an iron plate with emery passing the 80 sieve, till it is about 1/40 inch thick. From this point it must be reduced on ground glass by flours of emery and water; the rough particles of the former may be washed out for fine work. The process of grinding should not take more than half an hour if the section is properly cut, etc. Beyond this point the allowable thickness must depend on the nature of the rock; a good general rule is to get the section just so thin that felspars show the yellow of the first order in a polarising, microscope. The section is then finished with, say, two minutes emery or water of Ayr-stone dust. It is better not to have the surface too smooth. To transfer the section, the hard Canada round the sides is scraped away, and the section itself covered with some fresh Canada from the bottle. It is then warmed till it will slip off when a pin, or the invaluable dentist's chisel, is pressed against one side. If the section be very delicate, the cover slip should be placed over it before it is moved to the proper slide. The Canada used for mounting is not quite so hard as that employed in grinding, but it should be hard when cold, i.e. not sticky. The art of preparing Canada balsam appears to consist in heating it under such conditions as will ensure its being exposed in thin layers. I have wasted a good deal of time in trying to bake Canada in evaporating basins, with the invariable result that it was either over or under-baked, and got dark in colour during the process. On reviewing the process of rock section-cutting and mounting as just described, I cannot help thinking that, if properly systematised, it could be made much more rapid by the introduction of proper automatic grinding machinery. It also seems not improbable that a proper overhaul of available gums and cements would be found to lead to a cementing material less troublesome than Canada balsam. § 79. Cutting Sections of Soft Substances. Though this art is fully treated of in books on practical biology, it is occasionally of use to the physicist, and the following note treats of that part of the subject which is not distinctly biological. Soft materials, of which thin sections may be required, generally require to be strengthened before they are cut. For this purpose a variety of materials are available. The one most generally used is hard paraffin. The only point requiring attention is the embedding. The material must be dry. This is accomplished by soaking in absolute alcohol, i.e. really absolute alcohol made by shaking up rectified spirit with potassium carbonate, previously dried, and then digesting for a day with large excess of quick-lime, making use of an inverted condenser and finally distilling off the alcohol without allowing it to come in contact with undried air. After soaking for some time in absolute alcohol, the material may be transferred to oil of bergamot, or oil of cloves, or almost any essential oil. After soaking in this long enough to allow the alcohol to diffuse out, the material may be lifted into a bath of melted paraffin (melting at, say, 51° C.). The process of soaking is in some cases made to go more rapidly by exhausting, and, if the material will stand it, by raising the temperature over 100° C. The soaking process may require minutes, hours, or days, according to the size and density of the material; but a few hours are usually sufficient. When cold, the sections may be cut in any of the ordinary forms of microtome. Another way of embedding is to soak in collodion, and then precipitate the latter in the material and around it by plunging into nearly absolute alcohol. The collodion yields a harder matrix than the paraffin. Whatever form of cutting machine is employed, the art of sharpening the knife is the only one requiring any particular notice. The easiest way of obtaining a knife hard enough to sharpen, is to use a razor of good quality. If it has to be ground, it is best to do this on a fine Turkey stone which is conveniently rested on two bits of rubber tubing, to avoid jarring the blade. Many stones are slightly cracked, but on no account must the razor be dragged across a crack, or the edge will suffer. The necessary and sufficient condition is that the razor must be worked in little sweeps over the stone, and pressed against the latter by little more than its own weight, and the grinding must be regular. The edge may be inspected under a microscope, and it must be perfectly smooth and even before it will cut sections. A finishing touch may be given on a leather strap, but it must be done skilfully, otherwise it is better omitted. The necessity for providing exceptionally keen and sharp edges arose in the manufacture of phonographs, where the knife used to turn up the wax cylinders must leave a perfectly smooth surface. In 1889 this was being accomplished on an ivory lap fed with a trace of very fine diamond dust. I have had this method in mind as a possible solution of the difficulty of razor-grinding, but have not tried it. I imagine one would use a soft steel or ivory slip rubbed over with fine diamond dust and oil by means of an agate. The lap used in the phonograph works was rotated at a high speed. § 80. On the Production of Quartz Threads. [Footnote: Since this was written an article on the same subject by Mr. Boys appeared in the Electrician for 1896. The instructions therein given are in accordance with what I had written, and I have made no alteration in the text.] In 1887 the important properties of fused quartz were discovered by Mr. Vernon Boys (Philosophical Magazine, June 1887, p. 489, "On the Production, Properties, and Some Suggested Uses of the Finest Threads"). A detailed study of the properties of quartz threads was made by Mr. Boys and communicated to the Society of Arts in 1889 (Journal of the Society of Arts, 1889). An independent study of the subject was made by the present writer in 1889 (Philosophical Magazine, July 1890, "On the Elastic Constants of Quartz Threads "). There is also a paper in the Philosophical Magazine for 1894 (vol. xxxvii. p. 463), by Mr. Boys, on "The Attachment of Quartz Fibres." This paper also appeared in the Journal of the Physical Society at about the same date, together with an interesting discussion of the matter. In the American Journal, Electric Power, for 1894, there is a series of articles by Professor Nichols on "Galvanometers," in which a particular method of producing quartz threads is recommended. The method was originally discovered by Mr. Boys, but he seems to have made no use of it. A hunt through French and German literature on the subject has disclosed nothing of interest--nothing indeed which cannot be found in the papers mentioned. § 81. Quartz fibres have two great advantages over other forms of suspension when employed for any kind of torsion balance, from an ordinary more or less "astatic" galvanometer to the Cavendish apparatus. In the first place the actual strength of the fibres under longitudinal stress is remarkably high, ranging from fifty to seventy tons weight per square inch of section, and even more than this in the case of very fine threads; the second and more important point in favour of quartz depends on the wide limits within which cylindrical threads of this material obey the simplest possible law of torsion, i.e. the law that for a given thread carrying a given weight at a given temperature and having one end clamped, the twist about the axis of figure produced by a turning moment applied at the free end is proportional simply to the moment of the twisting forces, and is independent of the previous history of the thread. It is to be noted, however, that the torsional resilience of quartz as tested by the above law is not so perfect but that our instrumental means allow us to detect its imperfections, and thus to satisfy ourselves that threads made of quartz are not things standing apart from all other materials, except in the sense that the limits within which they may be twisted without deviating in their behaviour from the law of strict proportionality by more than some unassigned small quantity, are phenomenally wide. A torsion balance--if we except the case of certain spiral springs--is almost always called upon for information as to the magnitude of very small forces, and for this purpose it is not essential merely that some law of twisting should be exactly obeyed, but also that the resistance to twisting of the suspension should be small. Now, regarded merely as a substance possessing elastic rigidity, quartz is markedly inferior to the majority of materials, for it is very stiff indeed; its utility depends as much as anything upon its great strength, for this allows us to, use threads of exceeding fineness. In addition to this it must be possible, and moreover readily possible, to obtain threads of uniform section over a sufficient length, or the rate of twist per unit length of the thread will vary in practice from point to point, so that the limits of allowable twist averaged over the whole thread may not be exceeded, and yet they may be greatly overpassed at particular points of the thread. It is interesting to note that in the case of quartz we not only have a means for readily producing very uniform cylindrical threads, but that the limits of allowable rate of twist are so wide that a small departure from uniformity of section produces much less inconvenience than in the case of any other known substance. § 82. There are three methods generally in use for drawing quartz fibres, all depending on the fact that quartz when fused is so viscous that it may be drawn into threads of great length, without these threads breaking up into drops, or indeed without their showing any sign of doing so. The surface tension of the melted quartz must, however, be very considerable, as may be seen by examining the shape of a drop of the molten material, and this suffices to impress a rigidly cylindrical form upon the thread, the great viscosity apparently damping down all oscillation. The first method is the one originally employed by Mr. Boys. A needle of quartz is melted somewhere in its length and is then drawn out rapidly by a light arrow, to which one end of the needle is attached, and which is projected from a kind of crossbow. A modification of this method, which the writer has found of service when very thick threads are required, is to replace the bow and arrow by a kind of catapult. The third method, which yields threads of almost unmanageable fineness, depends on the experimental fact that when a fine point of quartz is held in a high pressure oxygen gas blow-pipe flame, the friction of the flame gases suffices to overcome the tendency of the capillary forces to produce a spherical drop, and actually causes a fine thread to be projected outwards in the direction of the flame. § 83. A preliminary operation to any method is the production of a stick of fused quartz. This is managed as follows. A rock crystal or quartz pebble is selected and examined. It must be perfectly white, transparent, and free from dirt. Surface impurity can of course be got rid of by means of a grindstone. The crystal is placed in a perfectly clean Stourbridge clay crucible, furnished with a cover, and heated to bright redness for about an hour in a clean fire or in a Fletcher's gas furnace. The contents of the crucible are turned out when sufficiently cool on to a clean brick or bit of slate. It will be found that the crystal is completely broken up and the fragments must be examined in case any of them have become contaminated by the crucible, but this will not have happened if the temperature did not rise beyond a bright red heat. The heap of fragments being found satisfactory, the next thing is to fuse some of the pieces together. Unless the preliminary heating has been efficiently carried out this will prove an annoying task, because a rock crystal generally contains so much water that it splinters under the blow-pipe in a very persistent manner. There are two ways of assembling the fragments. One is to place two tiles or bricks on edge about the heap of quartz lying upon a third tile, so that the heap occupies the angular corner or nook formed by the tiles (Fig. 64). The oxygas blow-pipe previously described is adjusted to give its hottest flame, the bags being weighted by at least two hundredweight, if of the size described (see § 15). The tip of the inner cone of the blow-pipe is brought to bear directly upon one of the fragments, and if the operation is performed boldly it will be found that the surface of the fragment can be fused, and the fragment thus caused to hold together before the lower side gets hot enough to suffer any contamination from the tile or brick. A second fragment may be treated in the same way, and then a third, and so on. Finally, the fragments may be fused together slightly at the corners, and a stick may thus be formed. Of course a good deal of cracking and splitting of the fragments takes place in the process; the best pieces to operate upon are those which are well cracked to begin with, and that in such a way that the little fragments are interlocked. An alternative method which has some advantages is to arm a pair of forceps with two stout platinum jaws, say an inch and a half long, and flattened a little at the ends. The fragments are held in these platinum forceps and the blow-pipe applied as before. This method works very well in adding to a rod which has already been partly formed, but the jaws require constant renewals. The first fragment which is fused sufficiently to cohere may also be fused to a bit of tobacco pipe, or hard glass tube or rod, and the quartz stick gradually built up by fusing fresh pieces on to the one already in position. Fig. 64. Since the glass or pipeclay will contaminate the quartz which has been fused on to it, it is necessary to discard the end pieces at the close of the operation. A string of fragments having been collected and stuck together, the next step is to fuse them down into a uniform rod. This is easily done by holding the string in the blow-pipe flame and allowing it to fuse down. Twisting the fused part has a good effect in assisting the operation. It is desirable to use a large jet and as powerful a flame as can be obtained during this part of the operation. The final result should be a rod, say two or three inches long and one-eighth of an inch thick, which will in most cases contain a large number of air bubbles. Since the presence of drawn-out bubbles cannot be advantageous, it is often desirable to get rid of them, and this can conveniently be done at the present stage. The process at best is rather tedious; it consists in drawing the quartz down very fine before an intense flame, in order to allow the bubbles to get close enough to the surface to burst. A considerable loss of material invariably occurs during the process; for whenever the thin rod separates into two bits the process of flame-drawing of threads goes on, and entails a certain waste; moreover, the quartz in fine filaments is probably partially volatilised. Sooner or later, however, a sufficient length of bubble-free quartz can be obtained. It must not be supposed that it is always necessary to eliminate bubbles as perfectly as is contemplated in the foregoing description of the treatment, but for special purposes it may be essential to do so, and in any case the reader's attention is directed to a possible source of error. It may be mentioned in connection with this matter that crystals of quartz may look perfectly white and clear, and yet contain impurity. For instance, traces of sodium are generally present, and lithium was found in large spectroscopic quantity in five out of six samples of the purest crystals in my laboratory. The presence of lithium in rock crystal has also been detected by Tegetmeier (Vied. Ann, xli. p. 19, 1890). After some practice in preparing rods and freeing them of bubbles the operator will notice a distinct difference in the fusibility of the samples of quartz he investigates, though all may appear equally pure to the unaided eye. It should be mentioned, however, that high infusibility cannot always be taken as a test of purity, for the most infusible, or rather most viscous, sample examined by the writer contained more lithium than some less viscous samples. Fig. 65. During the process of freeing the quartz from bubbles the lithium and sodium will be found to burn away, or at all events to disappear. A rod of quartz, say three inches long, one-sixteenth of an inch in diameter, and free from bubbles for half an inch of its length, even when examined by a strong lens, is suitable for drawing into threads. The rod is manipulated exactly in the manner described under glass-blowing, and is finally drawn down at the bubble free part into a needle, say 0.02 inch in diameter (No. 25 on the Birmingham wire gauge), and 2 inches long. Fig. 66. There is one peculiarity about fused quartz which renders its manipulation easier than that of glass--it is impossible to break fused quartz, however suddenly it be thrust into the blow-pipe flame. A rod having a diameter of three-sixteenths of an inch--and perhaps much more--may be brought right up to the tip of the inner cone of the oxy-gas flame and held there-till one side fuses, the other being comparatively cool, without the slightest fear of precipitating a smash. In seven years' experience I have never seen a bit of once fused quartz broken by sudden heating; whether it might be done if sufficient precautions were taken I do not know. The reason of the fortunate peculiarity of quartz in this respect is, I presume, to be found in the fact that quartz once it has been fused is really a very strong material indeed, and is also probably the least expansible substance known. From some experiments of the writer upon the subject, it may be concluded that at the most quartz which has been fused expands only about one-fifth as fast as flint-glass, at all events between 20° and 70° C. § 84. Drawing Quartz Threads. The thick end of the rod of quartz is held in the fingers or occasionally in a clip. The end of the fine point is attached to a straw arrow by means of a little sealing-wax. The arrow is laid on the stock of a crossbow in the proper position for firing. See Figs. 67 and 68, which practically explain themselves. The needle is heated by the blow-pipe till a minute length is in a state of uniform fusion; the arrow is then let fly, when it draws a thread out with it. The arrow is preferably allowed to strike a wooden target placed, say, 30 feet away from the bow, and a width of black glazed calico is laid under the line of fire to catch the thread or arrow if it falls short. The general arrangements will be obvious from the figure. The bow is of pine in the case where very long thin threads are required, though for ordinary purposes I have found a bow of lance-wood succeed quite as well. The trigger of the bow consists of a simple pin passing through the stock and fastened at its lower end to a string connected with a board which can be depressed by foot. In the figure an ordinary trigger is shown, but the pin does just as well. Fig 67. The arrow is made out of about 6 inches of straw, plugged up aft by a small plug of pine or willow fastened in with sealing-wax, and projecting backwards one-eighth of an inch. This projection serves a double purpose: it gives a point of attachment for the quartz needle, and on firing the bow it forms a resisting anvil on which the string of the bow impinges. The head of the arrow is formed by a large needle stuck in with sealing-wax, and heavy enough to bring the centre of gravity of the arrow forward of one-third of its length, the condition of stability in flight. Fig. 68. It is not necessary to employ any feathering for these arrows; though I have occasionally used feathers or mica to "wing the shaft" no advantage has resulted therefrom. To get fine threads a high velocity is essential. This is obtained by considering (and acting upon) the principles involved. The bow may be regarded as a doubly-tapering rod clamped at the middle. After deflection it returns towards its equilibrium position at a rate depending in general terms on the elastic forces brought into play, directly, and on the effective moment of inertia of the rod, inversely (see Rayleigh, Sound, vol. ii. chap. viii.) If the mass of the arrow is negligible compared with the bow, the rate at which the arrow moves is practically determined by that attained by the end of the bow, which is a maximum in crossing its equilibrium position. The extent to which the arrow profits by this velocity depends on the way the bow is strung. It will be greatest when the string is perpendicular to the bow when passing its equilibrium position; or in other words, when the string is infinitely long. Since the string has mass, however, it is not permissible to make it too long, or its weight begins to make itself felt, and a point is soon reached at which the geometrical gain in string velocity is compensated for by the total loss of velocity due to the inertia of the string. In practice it is sufficient to use a string 10 per cent longer than the bow. It is well to use a light fiddle string, served with waxed silk at the trigger catch; if this be omitted the gut gets worn through very quickly. In order to decide how far it is permissible to bend the bow, the quickest way is to make a rough experiment on a bit of the same plank from which the bow is to be cut, and then to allow a small factor of safety. In the figure the bow is of lance-wood and is more bent than would be suitable for pine. The bow itself is tapered from the middle outwards just like any other bow. If thick threads are required, the above considerations are modified by the fact that quartz opposes a considerable resistance to drawing, and that consequently the arrow must not only have a high velocity, but a fair supply of energy as well; in other words, it must be heavy. A thin pine arrow instead of a straw generally does very well, but in this case the advantage of using pine for the bow vanishes; and in fact lance-wood does better, owing to the greater displacement which it will stand without breaking. This of course only means that a greater store of energy can be accumulated at one bending. I had occasion to investigate whether the unavoidable spin of an arrow about its axis produces any effect on the thread, and for this purpose made arrows with inertia bars thrust through the head, i.e. an arrow with a bit of wire run through it, perpendicular to its length--forming a cross in fact--the arms of the cross being weighted at the extreme ends by shot. This form of arrow has a considerable moment of inertia about its longer axis, and consequently rotates less than a mere straw, provided that the couples tending to produce rotation are not increased by the cross arm, or the velocity too much reduced. Shooting one of these arrows slowly, I could see that it did not rotate, and when fired at a high velocity, it generally arrived at the target (placed at varying distances front bow) with the arms nearly horizontal, thus showing that it probably did not rotate much. I did not succeed in this at the first trial, by any means. The threads got in this way were no better than those made with a single straw, whence we may conclude very provisionally that the spin of the arrow has only a small effect, if any, on the quality of the threads. Feathering the arrow, in my experience, tends, if anything to make it spin more; for one thing, because it is practically impossible to lay the feathering on straight. After the arrow is shot, it remains to gather in the thread, and if the latter is at all thin, we have a rather troublesome job. In a thread thirty or forty feet long, the most uniform part generally lies in the middle if the thread is thin, i.e. of the order of a ten-thousandth of an inch in diameter. If the thread is thick the most uniform part may be anywhere. The part of the thread required is generally best isolated by passing a slip of paper under it at each end and cementing the thread to the paper by means of a little paraffin or soft wax, and then cutting off the outer portions. One bit of paper may then be lifted off the calico, and the thread will carry the other bit. In this way the thread may be taken to a blackened board, where it may be mounted for stock. By passing the two ends of the thread under a microscope, or rather by breaking bits off the two ends and examining them together, it is easy to form an Opinion as to uniformity. Mr. Boys has employed an optical method of examining threads, but the writer has invariably found a high-power microscope more convenient and capable of giving more exact information as to the diameter of the threads. The beginner--or indeed the practised hand--need not expect to get a thread of the exact dimensions required at the first shot. A little experience is necessary to enable one to judge of the right thickness of the needle for a thread of given diameter. The threads are so easily shot, however, that a few trials take up very little time and generally afford quite sufficient experience to enable a thread of any required diameter to be prepared. It is no use attempting to heat an appreciable length of needle; if this be done the thread almost invariably has a thick part about the middle of its length.. It is sufficient to fuse at most about one-twentieth of an inch along the needle before firing off the bow. This can be done by means of the smaller oxygas blow-pipe jet described in the article on blow-pipes for glass-blowing, § 14. The flame must of course be turned down so as to be of a suitable size. A sufficiently small flame may be got from almost any jet. If the needle be not equally heated all round, the thread tends to be curly; indeed by means of the catapult, threads may be pulled which, when broken, tend to coil up like the balance-springs of watches, if only care be taken to have one side of the needle much hotter than the other. § 85. When examining bits of threads, say thicker than the two-thousandth of an inch, under the microscope it is convenient to use a film of glycerine stained with some kind of dye, in order to render the thread more sharply visible. The thread is mounted beneath a cover slip, and a drop of the stained glycerine allowed to run in. Such a treatment gives the image of the thread a sharply defined edge 3 and the contrast between the whiteness of the thread and the colour of the background allows measurements to be made with great ease. On the whole the easiest way of measuring the diameter of a thick thread is to use a measuring microscope, i.e. one in which the lens system can be displaced along a plane bed by means of a finely cut micrometer screw. The instruments made by the Cambridge Scientific Instrument Company do fairly well. Direct measurements up to 0.0001 inch are easily made by means of a microscope provided with a Zeiss "A" objective, and rather smaller differences of thickness can be made out by it. For thin threads the method next to be described is more fitting, because higher powers can be more conveniently used. In this method an ordinary microscope is employed together with a scale micrometer, and either an eyepiece micrometer, or a camera and subsidiary scale. The eyepiece micrometer is the more convenient. If a camera be employed, i.e. such an one as is supplied by Zeiss, it is astonishing how the accuracy of observation may be increased by attending carefully to the illumination of both the subsidiary scale and of the thread. The two images should be as far as possible of equal brightness, and for this purpose it will be found requisite to employ small screens. The detail of making a measurement by means of the micrometer eyepiece is very simple. The thread is arranged on the stage so as to point towards the observer, and the apparent diameter is read off on the eyepiece scale. In order to calibrate the latter it is only necessary to replace the thread by the stage micrometer, and to observe the number of stage micrometer divisions occupying the space in the eyepiece micrometer formerly occupied by the thread. It is essential that both thread and stage micrometer should occupy the same position in the field, for errors due to unequal distortion may otherwise become of importance. For this reason it is best to utilise the centre of the field only. The same remark applies to measurements by means of the camera, where the image of the thread is projected against the reflected image of the subsidiary scale laid alongside the microscope. In this case the value of the subsidiary scale divisions must be obtained from the divisions of the stage micrometer, coinciding as nearly as possible with the position occupied by the thread. Before commencing a measurement the screens are moved about till both images appear equally bright. Threads up to about one twenty-thousandth of an inch in diameter may be sufficiently well measured by means of a Zeiss "4 centimetre apochromatic object-glass" and an eyepiece "No. 6" with sixteen centimetre tube length. [Footnote: The objective certainly had "4 cm." marked on it, but the focal length appeared to be about I.5 mm. only.] § 86. Drawing Threads by the Catapult. The bow-and-arrow method fails when threads of a greater diameter than about 0.0015 inch are required--at least if any reasonable uniformity be demanded, and no radical change in the bow and arrow be carried out. Thus in the writer's laboratory a thread of about this diameter, within 1/10000 of an inch-13 inches long and free from air bubbles--was required. A fortnight's work by a most skilful operator only resulted in the production of two lengths satisfying the conditions. The greatest loss of time occurs in the examination of the thread by means of the microscope. Threads for galvanometer suspensions are conveniently from 0.0001 to 0.0004 inch in diameter, and are much more easily made and got uniform than thicker threads, to the production of which the catapult method applies. A reference to the diagram will make the construction of the instrument quite clear. The moving end of the quartz is attached to a small boxwood slider working on a tubular girder or between wires. The quartz is secured in position by clamps shown at A and B, and motion is imparted to the slider by a stretched piece of catapult elastic (C). An easy means of regulating the pull of the elastic is to hold it back by a loop of string whose length can be varied by twisting it round a pin. Fig. 69. [Footnote: For greater clearness of drawing, the tube carrying the slider is shown somewhat higher above the base than is convenient in practice; and the slide itself is shown too thin in the direction of the hole through it.] Since it is not permissible to allow the slider to rebound at the end of its journey, some such arrangement of breaks as is shown must be adopted. In the diagram the bottom of the slider runs on to a brass spring between the girder and the base of the appliance, and so gets jammed; the spiral spring acts merely as an additional guard. The diagram does not show the lower spring very clearly; it is a mere strip lying in the groove. A rod of quartz, with a needle at one end, is prepared as before and secured in the clamps. During the operation of fastening down the clamps, there is some danger of breaking the needle, and consequently it is advisable to soften the latter before and while adjusting the second clamp. The process of drawing a thread by this method is exactly similar to the operation already described in connection with the arrow method. Though short thick threads form the product generally obtained from the catapult, it must not be supposed that thin threads cannot be obtained in this way. If a short length of a very fine needle be heated, it will be found to yield threads quite fine enough for ordinary suspension purposes, but naturally not so uniform as those obtained from the 40-foot lengths obtainable by the bow-and-arrow method. It is easy to make spiral quartz springs resembling watch balance-springs by means of the catapult. All that is necessary is to see that the quartz is rather unequally heated before the shot is fired. In the future it is by no means impossible that such springs may have a real value, for the rigidity of quartz is known to increase as temperature rises. Hence it is probable that the springs would become stiffer as temperature rises, even though they work chiefly by bending, and little or not at all by twisting. As this is the kind of temperature variation required to compensate an uncompensated watch balance wheel, it may turn out to have some value. § 87. Drawing Threads by the Flame alone. A stick of quartz is drawn down to a fine point, and the tip of this point is held in the blow-pipe flame in the position shown in Fig. 70. Fig. 70. The friction of the flame gases is found to be sufficient to carry forward the fused quartz and to draw it into threads in spite of the influence of the capillary forces. If a sheet of paper be suspended at a distance of two or three feet in front of the blow-pipe flame, it will be found to be covered with fine threads tangled together into a cobwebby mass. As this method is an exceedingly simple one of obtaining threads, I have endeavoured to reduce it to a systematic operation. A sheet of cardboard, about two feet square, is painted dead black and suspended horizontally, painted side downwards (Fig. 70, A), at a height of about two feet above the blow-pipe flame. The latter is adjusted so as to point almost vertically upwards and towards the centre of the cardboard. A few half-inch pins are thrust through the card from the upper surface and pushed home; about one dozen pins scattered over the surface will be sufficient. Their object is to prevent the threads being carried away round the edge of the screen. The flame from the jet described so often is fed from gas bags weighted to about eighty pounds per square foot of (one) surface, i.e. "4-foot" bags require from three to four hundredweight to give an advantageous pressure. [Footnote: The resulting threads were really too fine for convenient manipulation, so that unless extremely fine threads are required it will be better to reduce the pressure of the gases considerably.] Two sticks of quartz are introduced and caused to meet just in front of the inner cone--the hottest part of the flame. They are then drawn apart so as to form a fine neck, which softens and is bent in the direction of motion of the flame gases. When fusion is complete the neck separates into two parts, and a thread is drawn from each of them. By alternately lightly touching the rods together, and drawing them apart, quite a mass of threads may be obtained in two or three minutes, when the process should be stopped. If too many threads get entangled in the pins, one gives one's self the unnecessary trouble of separating them. On taking down the card it will be found that the threads have been caught by the pins; but the card now being laid black side upwards, the former easily slip off the points. Threads at least a foot long, and perhaps vastly longer, may be obtained by this method, and are extraordinarily fine. When I first read Professor Nichols' statement (Electric Power, 1894) as to the value of these fibres for galvanometer purposes, I was rather sceptical on the ground that the threads would tend to get annealed by being drawn gradually, instead of suddenly, from a place of intense heat to regions of lower temperature. Now annealing threads by a Bunsen makes them rotten. The threads being immersed in the hot flame gases could only cool at the same rate as the gas, and it was not--and is not--clear to me that annealing of the threads can be avoided. On the other hand, it may be possible that a thread cooled slowly from the first does not suffer in the same way as a cold thread would do when annealed in a Bunsen flame. Again the velocity of the gases is beyond doubt exceedingly high, so that the annealing, even supposing it to be deleterious, might not be carried very far. Threads drawn by this method and measured "dry," i.e. by mounting them on a slide without the addition of any liquid, turned out to have a diameter of about 1/20000 of an inch. I do not think I could manage to mount such fine threads without very special trouble. All the threads lying on the board, however, were found in reality to consist of three or four separate threads, and there is no reason why several threads should not be mounted in parallel, provided, of course, that they are equally stretched and touching each other. Equality of tension in the mounting could be secured by making one attachment good, then cementing the other attachment to the other end of the threads, and "drawing" the two attachments slightly apart at the moment the cement commences to set. This method may turn out to be very valuable, for, so far as I can see, the carrying power would be increased without an increase of torsional stiffness of anything like so high an order as would be the case were one thread only employed. On the other hand, the law of torsion could hardly be quite so simple, at all events, to the second order of approximations. § 88. Properties of Threads. A large number of experiments on the numerical values of the elastic constants of quartz threads have been made by Mr. Boys and his students, and by the writer. As the methods employed were quite distinct and the results wholly independent, and yet in good agreement with each other, a rounded average may be accepted with considerable confidence. TENACITY OF QUARTZ FIBRES (BOYS). Diameter of Thread. Tenacity in Tons' Weight per Square Inch of Section. Tenacity in Dynes per Square Centimetre. Inches Centimetres 0.00069 0.00175 51.7 8 X 109 0.00019 0.00048 74.5 11.5 X 109 Rounded mean of Boys' and Threlfall's results: Young's Modulus at 20° C, 5.6 X 1011 C.G.S. Modulus of Simple Rigidity at 20° C, 2.65 X 1011 C.G.S. Modulus of Incompressibility, 1.4 X 1011 C.G.S. Modulus of Torsion, 3.7 X 1011 C.G.S. Approximate coefficient of linear expansion of quartz per degree between 80° C. and 30° C. is 0.0000017 (Threlfall = loc. cit.). This must be regarded with some suspicion, as the data were not concordant. There is no doubt, however, about the extreme inexpansibility of quartz. Temperature coefficient of modulus of torsional rigidity per degree centigrade, 22° to 98° C, 0.000133 Ditto, absolute simple rigidity, 0.000128 (Threlfall). Limit of allowable rate of twist in round numbers is, one-third turn per centimetre, in a fibre 0.01 cm. diameter. The limiting rate is probably roughly inversely as the diameter. Attention must be called to the rapid increase in the torsional rigidity of these threads as the temperature rises. A quartz spiral spring-balance will be appreciably stronger in hot weather. § 89. In the majority of instances in which quartz threads are applied in the laboratory, it is desirable to keep the coefficient of torsion as small as possible, and hence threads are used as fine as possible. It is convenient to remember that a thread 0.0014 cm. or 0.0007 inch in diameter breaks with a weight of about ten grammes, and may conveniently be employed to carry, say, five grammes. With threads three times finer the breaking strength per unit area increases, say, 50 per cent. In ordinary practice--galvanometric work for instance--where it is desirable to use a thread as fine and short as possible to sustain a weight up to, say, half a gramme, it will be found that fibres five centimetres long or over give no trouble through defect of elastic properties. A factor of safety of two is a fair allowance when loading threads. No difficulty will be experienced in mounting threads having a diameter of 0.0002 inch or over. With finer threads it is necessary to employ very dark backgrounds (Mr. Boys uses the darkness of a slightly opened drawer), or the threads cannot be sufficiently well seen. In the case of instruments in which threads remain highly twisted for long periods of time, the above rule as to the safe limit of twist does not allow of a sufficient margin; it is only applicable to galvanometric and similar purposes. The cause of the increase in tenacity as the diameter diminishes is at present unknown. It is due neither to an effect of annealing (annealed threads are rotten), nor is it a skin effect, nor is it due to the cooling of the thread under higher capillary pressure. It is, however, possible that it may be associated with some kind of permanent set taken by the fibres during the stage of passage from the liquid to the solid state. § 90. On the Attachment of Quartz Fibres. For many purposes it is sufficient to cement the fibres in position by means of ordinary yellow shellac, but where very great accuracy is aimed at, the shellac (being itself imperfectly elastic and exposed to shearing stress) imposes its imperfections on the whole system. This source of error can be got over by soldering the threads in position. Attempts were made by the writer in this direction, with fair success, in 1889, but as Mr. Boys has carried the art to a high degree of perfection, I will suppress the description of my own method and describe his in preference. It has, of course, been frequently repeated in my laboratory. In many cases, however, if not in all, it may be replaced by Margot soldering, as already described, a note on the application of which to this purpose will follow. A thread of the proper diameter having been selected, it is cut to the right length. With fine threads this is not always a perfectly easy matter. The best way is for the operator to station himself facing a good light, not sunlight, which is too tiring to the eye, but bright diffused light. The thread will be furnished with bits of paper stuck on with paraffin at both ends, as already described. A rough sketch of the apparatus--or, at all events, two lines showing the exact length which the free part of the thread must have--are marked on a smooth board, and this is supported with its plane vertical. The thread is held against the board, and the upper piece of paper is stuck lightly to the board with a trace of soft wax, so that the lower edge of the paper is at any desired height above the upper mark. This distance is measured, and forms the length of thread allowed to overlap the support. A second bit of paper is attached below the lower mark, a margin for the attachment of the lower end being measured and left as before. The thread will be most easily seen if the board is painted a dead black. If it is desired to attach the thread to its supports merely by shellac, this is practically all that needs to be done. The supports should resemble large pins. The upper support will be a brass wire in most cases, and will require to be filed away as shown in the sketch (Fig. 71). It is then coated with shellac by heating and rubbing upon the shellac. As previously noted, the shellac must not be overheated. The thread is cut off below the lower slip of paper, and the upper support being conveniently laid in a horizontal position on another dead-black surface, the thread is carried to it and laid as designed against the shellac, which is now cold. When the thread is in place, a soldering iron is put against the brass wire, and the shellac gradually melted till it closes over the thread. Fig. 71. The iron is then withdrawn and the thread pulled away from the point for one-twentieth of an inch or less. This ensures that the thread makes proper contact with the cement, and also that it is free from kinks; of course, it must leave the cement in the proper direction. A similar process is next carried out with respect to the lower attachment, and the ends of the thread are neatly trimmed off. Both ends of the thread being secured, the next step is to transfer the upper support to a clip stand, the suspended parts being held by hand, so that the weight comes on the thread very gradually. In this way it will be easily seen whether the thread is bent where it enters the shellac, and should this be the case, a hot iron must be brought up to the shellac and the error rectified. When both the support and the suspended parts are brought nearly to the required bearing, the hot iron is held for a moment close up to each attachment, the hand being held close below but not touching the suspended parts, and both attachments are allowed to straighten themselves out naturally. These details may appear tiresome, and so they are when written out at length, but the time occupied in carrying them out is very short, and quartz threads break easily, unless the pull upon them is accurately in the direction of their length at all points. In the event of its being decided to attach the thread by soldering, the process is rather more expensive in time, but not otherwise more troublesome. Fig. 72. Fig. 73. The thread being cut as before to the proper length, little bits of aluminium foil are smeared all over with melted shellac and suspended from the thread replacing the paper slips before described. It is important that no paraffin should be allowed to touch the thread anywhere near a point intended to be soldered. The thread is hung up from a clip stand by one of the bits of foil, and the lower end is washed by dipping it into strong nitric acid for a moment and thence into water. The object of smearing the foils all over with shellac is to prevent them being acted upon by the acid. The threads are not very easily washed acid free, but the process may be assisted by means of a fine camel's-hair pencil. Some silvering solution made as described (§ 65) is put into a test tube; the thread, after rinsing with distilled water, is lowered into the solution so far as is required, and is allowed to receive a coating of silver. It has been observed that the coating of silver must not be too thick--not sufficiently thick to be opaque. A watch may be kept on the process by immersing a minute strip of mica alongside the thread. The silvered thread is rinsed with distilled water and allowed to dry. Meanwhile the other end of the thread may be silvered. When both ends are silvered the process of coppering by electro deposit is commenced. A test tube is partially filled with a ten per cent solution of sulphate of copper, and several copper wires are dipped into it to form an anode. The thread is lowered carefully into the solution so as not to introduce air bubbles, and the silvered part is allowed to project far enough above the surface of the solution to come in contact with a fine copper wire. The circuit is closed through a Leclanché cell and a resistance box. It is as well to begin with a fair resistance, say 100 ohms out in the box, and the progress of the deposit is watched by means of a low-power microscope set up in front of the thread. If the copper appears to come down in a granular form, the resistance is too small and must be increased; if no headway appears to be made, the resistance must be diminished. As soon as a fair coat of copper has come down, i.e. when the diameter of the thread is about doubled, the process is interrupted. The thread is withdrawn, washed, dipped in a solution of chloride of zinc, and carefully tinned by dragging it over a small clean drop of solder on a soldering bit. During this part of the process the shellac is apt to get melted if the iron is held too close, so that it is advisable to begin by making the thread somewhat over long. The end of the thread must only be trimmed off at the conclusion of the operation, i.e. after the thread is soldered up. The thread is attached to the previously tinned supports much in the same way as has been described under the head of shellac attachments. It does not very much matter whether both ends are coppered before one is soldered up or not. At the conclusion of the whole process the superfluous copper and silver are dissolved off by a little hot strong nitric acid applied on a glass hair pencil. This is best done by holding the thread horizontally with the assistance of clip stands. If the thread is too delicate to bear brushing, the nitric acid may be applied by pouring out a big drop into a bit of platinum foil and holding this below the thread so as to touch it lightly. The dissolving of the copper and silver is, of course, followed by copious washing with hot water. This process is more laborious than might be imagined, but it may be shortened by heating the platinum foil supporting the water (Fig. 74). Fig. 74 The washing part of the process is, in the opinion of the writer, the most difficult part of the whole business, and it requires to be very thorough, or the thread will end by drawing out of the solder. In many cases it is better to try to do without any application of nitric acid at all, but, of course, this involves silvering and coppering to exact distances from the ends of the thread--at all events, in apparatus where the effective length of the thread is narrowly prescribed. It is important not to leave the active parts of the thread appreciably silvered, for the sake of avoiding zero changes due to the imperfect elasticity of the silver. In this soldering process ordinary tinman's solder may be employed; it must be applied very free from dust or oxide. § 91. Other Modes of soldering Quartz. Thick rods of quartz may be treated for attachment by solder in the same way as glass was treated by Professor Kundt to get a foundation for his electrolytically deposited prisms. [Footnote: See Appendix at end of book.] The application of a drop of a strong solution of platinum tetrachloride to the rod will, on drying, give rise to a film of the dry salt, and this may be reduced in the luminous gas flame. During the process, however, the quartz is apt to get rotten, especially if the temperature has been anything approaching a full red heat. The resulting platinum deposit adheres very strongly to the quartz, and may be soldered to as before. This method has been employed by the writer with success since 1887, and may even be extended to thick threads. It was also found that fusible metal either stuck to or contracted upon clean quartz so as to make a firm joint. In the light of M. Margot's researches (already described), it occurred to me that perhaps my experience was only a special case of the phenomena of adhesion investigated with so much success by M. Margot. I therefore tried whether the alloy of tin and zinc used for soldering aluminium would stick to quartz, and instantly found that this was indeed the case. Adhesion between the alloy and perfectly clean quartz takes place almost without rubbing. A rod of quartz thus "tinned" can be soldered up to anything to which solder will stick, at once. On applying the method to thick quartz threads, success was instantaneous (the threads were some preserved for ordinary galvanometer suspensions); but when the method was applied to very fine threads, great difficulty in tinning the threads was experienced. The operation is best performed by having the alloy on the end of an aluminium soldering bit, and taking care that it is perfectly free from oxide before the thread is drawn across it. There was no difficulty in soldering a thread "tinned" in this manner to a copper wire with tinman's solder, and the joint appeared perfect, the thread breaking finally at about an inch away from the joint. I allow Mr. Boys' method to stand as I have written it, simply because I have not had time as yet to make thorough tests of the durability of "Margot" joints on the finest threads; but I have practically no doubt as to its perfect applicability, provided always that the solder can be got clean enough when melted on the bit. Very fine threads will require to be stretched before tinning, in order to enable them to break through the capillary barrier of the surface of the melted solder. § 92. Soldering. It is almost unfair to the arts of the glass-blower or optician to describe them side by side with the humble trade of soldering. Nevertheless, no accomplishment of a mechanical kind is so serviceable to the physicist as handiness with the soldering bit; and, as a rule, there is no other exercise in which the average student shows such lamentable incapacity. The following remarks on the subject are therefore addressed to persons presumably quite ignorant of the way in which soldering is carried out, and do not profess to be more than of the most elementary character. For laboratory purposes three kinds of solder are in general sufficient. One is the ordinary tinman's solder composed of lead and tin. The second is "spelter," or soft fusible brass, and the third is an alloy of silver and brass called silver solder. Tinman's solder is used for most purposes where high temperatures are not required, or where the apparatus is intended to be temporary. The "spelter," which is really only finely granulated fusible brass, is used for brazing iron joints. The silver solder is convenient for most purposes where permanency is required, and is especially suited to the joining of small objects. § 93. Soft tinman's solder is made by melting together two parts of grain tin and one of soft lead--the exact proportions are not of consequence--but, on the other hand, the purer the constituents the better the solder. Within certain limits, the greater the proportion of tin the cleaner and more fusible is the solder. It is usually worth while to prepare the solder in the laboratory, for in this way a uniform and dependable product is assured. Good soft lead is melted in an iron ladle and skimmed; the temperature is allowed to rise very little above the melting-point. The tin is then added little by little, the alloy stirred vigorously and skimmed, and sticks of solder conveniently cast by sweeping the ladle over a clean iron plate, so as to pour out a thin stream of solder. If the solder be properly made it will have a mat and bright mottled surface, and will "crackle" when held up to the ear and bent. Perhaps the chief precaution necessary in making solder is to exclude zinc. The presence of a very small percentage of this metal entirely spoils the solder for tinman's work by preventing its "running" or flowing smoothly under the soldering bit. Fig. 75. Fig. 76. Fig. 77. § 94. Preparing a Soldering Bit. The wedge-shaped edge of one of the forms of bit shown in the sketch is filed to shape and the bit heated in a fire or on a gas heater. A bit of rough sandstone, or even a clean soft brick, or a bit of tin plate having some sand sprinkled over it, is placed in a convenient position and sprinkled with resin. As soon as the bit is hot enough to melt solder it is withdrawn and a few drops of solder melted on to the brick or its equivalent. The iron or bit is then rubbed to and fro over the solder and resin till the former adheres to and tins the copper head. It will be found advisable to tin every side of the point of the bit and to carry the tinning back at least half an inch from the edge. If the solder obstinately refuses to adhere, the cause is to be sought in the oxidation of the copper, or of the solder, or both--in either case the result of too high a temperature or too prolonged heating. The simple remedy is to get the iron hot, and then to dress it with an old file, so as to expose a bright surface, which is instantly passed over the resin as a means of preserving it from oxidation. If the process above described be now carried out, it will be found that the difficulty disappears. Before using the iron, wipe off any soot or coke or burned resin by means of an old rag. An iron tinned in this way is much to be preferred to one tinned by means of chloride of zinc. A shorter and more usual method is carried out as follows: The solution of chloride of zinc is prepared by adding bits of zinc to some commercial hydrochloric acid diluted with a little (say 25 per cent) of water. The acid may conveniently be placed in a small glazed white jar (a jam pot does excellently), and this should only be filled to about one-quarter of its capacity. An excess of zinc may be added. It may be fancy, but I prefer a soldering solution made in this way to a solution of chloride of zinc bought as a chemical product. The jar is generally mounted on a heavy leaden base, so as to avoid any danger of its getting knocked over, for nothing is so nasty or bad for tools as a bench on which this noxious liquid has been upset (Fig. 78). Fig. 78. To tin a soldering bit, a little of the fluid is dipped out of the jar on to a bit of tin plate bent up at the edges--a few drops is sufficient--and the iron is heated and rubbed about in the liquid with a drop of solder. If the iron is anything like clean it will tin at once and exhibit a very bright surface, but quite dirty copper may be tinned by dipping it for a moment in the liquid in the pot and then working it about over the solder. An iron so tinned remains covered with chloride of zinc, and this must be carefully wiped off if it is intended to use the iron with a resin or tallow flux in lead soldering. One disadvantage of this process is that the copper bit soon gets eaten into holes and requires to be dressed up afresh. On the other hand, an iron so tinned always presents a nice clean solder surface until the next time it is heated, when it generally becomes very dirty and requires to be carefully wiped before using. In my experience also an iron so tinned is more easily spoiled as to the state of its surface, "detinned," in fact, by overheating than when the tinning is carried out by resin and friction. When this happens, the shortest way out of the difficulty is the application of the old file so as to obtain a perfectly fresh surface. No one who knows his business ever uses an iron that is not perfectly clean and well tinned. The iron may be cleaned from time to time by heating it red hot and quenching it in water to get rid of the oxide, which scales off in the process. § 95. Soft Soldering. In the laboratory the chief application of the process is to copper soldering during the construction of electrical apparatus and to zinc soldering for general purposes. In ninety-nine cases out of every hundred where difficulties occur their origin is to be traced to dirt. There seems to be some inexplicable kink in the human mind which renders it callous to repeated proofs of the necessity for cleaning surfaces which it is intended to solder. The slightest trace of albuminous or gelatinous matter or shellac will prevent solder adhering to most metals and the same remark applies in a measure to the presence of oxides, although these may be removed by chloride of zinc or prevented from forming by resin or tallow. A touch with an ordinarily dirty hand--I refer to a solderer's hand--will often soil work sufficiently to make the adherence of solder difficult. The fluxes most generally employed are tallow for lead, resin or Venice turpentine for copper, chloride of zinc for anything except lead, which never requires it. The latter flux has the property (also possessed by borax at a red heat) of dissolving any traces of oxide which may be formed, as well as acting as a protecting layer to the metal. We may now turn to the consideration of a simple case of soldering, say the joining of two copper wires. The wires are first cleaned either by dipping in a bath of sulphuric and nitric acids--a thing no laboratory should be without--or by any suitable mechanical means. The cleaned wires are then twisted together--there is a regulation way of doing this, but it presents no advantage in laboratory practice--and the joint is sprinkled over with resin, or painted with a solution of resin in alcohol. The iron, being heated and floated with solder, is held against the joint, the latter being supported on a brick, and the solder is allowed to "sweat" into the joint. Enough solder must be present to penetrate right through the joint. Nothing is gained by rubbing violently with the iron. If the copper is clean it will tin, and if it is dirty it won't, and there the matter ends. Beginners generally use too small or too cold a bit, and produce a ragged, dirty joint in consequence. If the saving of time be an object, the joint may be twisted together on ordinarily dirty oxidised wires and heated to, say, 200° C. It is then painted with chloride of zinc and soldered with the bit. There is a difference of opinion as to the relative merits of chloride of zinc and of resin as a flux in soldering copper. Thus the standing German practice is, or was, to employ the former flux in every case for soldering electric light wires, while in England the custom used to be to specify that soldering should be done by resin, and this custom may still prevail; it lingers in Australia at all events. However, it is agreed on all hands that when chloride of zinc is used it must be carefully washed off. I have known of an electrical engineer insisting on his workmen "licking" joints with their tongues to ensure the total removal of chloride of zinc; it has a horrible taste; and I have occasionally pursued the same plan myself when the soldering of fine wires was in question. In any case, it is very certain that chloride of zinc left in a joint will ruin it sooner or later by loosening the contact between copper and solder. Very often it is requisite to solder together two extensive flat surfaces--for instance, in "chucking" certain kinds of brass work. The surfaces to be soldered must be carefully tinned, most conveniently by the help of the blow-pipe and chloride of zinc. After tinning, the surfaces are laid together and heated so as to "sweat" them together; the phrase, though inelegant, is expressive. 96. Soldering Tin Plate. If the plate be new and clean, a little resin or its solution in alcohol is all that is necessary as a flux. If the tin plate is rusty the rust must be removed and the clean iron, or rather mild steel, surface exposed. The use of chloride of zinc is practically essential in this case. Tin plate is often spotted with rust long before it becomes rusty as a whole, when, of course, it may be regarded as worn out, and such rust spots are most conveniently removed by means of the plumber's shave-hook. The shave-hook is merely a peculiarly shaped hard steel scraping knife on a handle (Fig. 79). Fig. 79 With tin plate the soldering of long joints is often necessary. The plate must be temporarily held in position either by binding with iron wire, fastening by clamps, or holding by an assistant. The flux is applied and the iron run slowly along the joint. Enough solder is used to completely float the tip of the iron. By arranging the joint so that it slopes downward slightly, and commencing at the upper end, the solder may be caused to flow after the iron, and will leave a joint with the minimum permissible amount of solder in it. By regulating the slope, heat of iron, etc, any desired quantity of solder may be run into the joint. § 97. Soldering Zinc. Zinc alloys with soft solder very easily, and by so doing entirely spoils it, making, it "crumbly," dirty, and preventing it running. Consequently, in soldering up zinc great care must be taken to prevent the solder becoming appreciably contaminated by the zinc. To this end the zinc surfaces are cleaned by means of a little hydrochloric acid, which is painted on instead of chloride of zinc. Plenty of solder is melted on to the work, and is drawn along over the joint by a single slow motion of the soldering bit. The iron must be just hot enough to make the solder flow freely, and it must never be rubbed violently on the zinc or allowed to linger in one spot; the result of the latter action will be to melt a hole through the zinc, owing to the tendency of this metal to form an easily fusible alloy with the solder. The art of soldering zinc is a very useful one in the laboratory. The majority of physicists appear to overlook the advantages of zinc considered as a material for apparatus construction. It is light, fairly strong, cheap, easily fusible, and yet hard and elastic when cold. It may be worked as easily as lead at a temperature of, say, 150° to 200° C, and slightly below the melting-point (423° C.) it is brittle and may & powdered. The property of softening at a moderate temperature is invaluable as a means of flattening zinc plate or shaping it in any way. During the work it may be held by means of an old cloth. Zinc sheet which has been heated between iron plates and flattened by pressure retains its flatness very fairly well after cooling. § 98. Soldering other Metals. Iron. The iron must be filed clean and then brushed with chloride of zinc solution. Some people add a little sat ammoniac to the chloride of zinc, but the improvement thus made is practically inappreciable. If the iron is clean it tins quite easily, and the process of soldering it is perfectly easy and requires no special comment. Brass. The same method as described for iron succeeds perfectly. The brass, if not exceedingly dirty, may be cleaned by heating to the temperature at which solder melts (below 200° C.), and painting it over with chloride of zinc, or dipping it in the liquor. If now the brass be heated again in the blow-pipe flame, it will be found to tin perfectly well when rubbed over with solder. German Silver, Platinoid, Silver, and Platinum are treated like iron. With regard to silver and platinum the same precautions as recommended in the case of zinc must be observed, for both these metals form fusible alloys with solder. Gold when pure requires no flux. Standard gold, which contains copper, solders better with a little chloride of zinc. Lead must be pared absolutely clean and then soldered quickly with a hot iron, using tallow as a flux. Since solder if over hot will adhere to lead almost anywhere, plumbers are in the habit of specially soiling those parts to which it is not intended that solder shall adhere. The "soiling" paint consists of very thin glue, called size, mixed with lampblack; on an emergency a raw potato may be cut in half, and the work to be soiled may be rubbed over with the cut surface of the potato. Hard Carbon or gas coke may be soldered after coating with copper by an electrolytic process, as will be described. § 99. Brazing. Soldering at a red heat by means of spelter is called brazing. Spelter is soft brass, and is generally made from zinc one part, copper one part; an alloy easily granulated at a red heat; it is purchased in the granular form. The art of brazing is applied to metals which will withstand a red heat, and the joints so soldered have the strength of brass. The pieces to be jointed by this method must be carefully cleaned and held in their proper relative positions by means of iron wire. It is generally necessary to soften iron wire as purchased by heating it red hot and allowing it to cool in the air; if this is not done the wire is usually too hard to be employed satisfactorily for binding. Very thin wire--i.e. above No. 20 on the Birmingham wire gauge--does not do, for it gets burned through, and perhaps allows the work to fall apart at a critical moment. The work being securely fastened, the next step is to cover the cleaned parts with flux in order to prevent oxidation. For this purpose "glass borax" is employed. "Glass" borax is simply ordinary borax which has been fused for the purpose of getting rid of water of crystallisation. The glass borax is reduced to powder in an iron mortar, for it is very hard, and is then made up into a cream with a little water. This cream is painted on to the parts of the work which are destined to receive the solder. The next step is to prepare the spelter, and this is easily done by mixing it with the cream, taking care to stir thoroughly with a flattened iron wire till each particle of spelter is perfectly covered with the borax. The mixture should not be too wet to behave as a granular mass, and may then be lifted on to the work by means of the iron spatula. Care must be taken to place the spelter on those parts only which are intended to receive it, and when this is done, the joint may be lightly powdered over with the dry borax, and will then be ready for heating. If the object is of considerable size it is most conveniently heated on the forge; if small the blowpipe is more convenient. In the latter case, place the work on a firebrick, and arrange two other bricks on edge about it, so that it lies more or less in a corner. A few bits of coke may also be placed on and about the work to increase the temperature by their combustion, and to concentrate the flame and prevent radiation. The temperature is gradually raised to a bright red heat, when the spelter will be observed to fuse or "run," as it is technically said to do. If the cleaning and distribution of flux has been successful, the spelter will "run" along the joint very freely, and the work should be tapped gently to make sure that the spelter has really run into the joint. The heating may be interrupted when the spelter is observed to have melted into a continuous mass. As soon as the work has fallen below a red heat it may be plunged into water, a process which has the effect of cracking off the glass-like layer of borax. There is, however, some risk of causing the work to buckle by this violent treatment, which must of course be modified so as to suit the circumstances of the case. If the joint is in such a position that the borax cannot be filed off, a very convenient instrument for its removal by scraping is the watchmaker's graver, a square rod of hard steel ground to a bevelled point (Fig. 80). Fig. 80. Several precautions require to be mentioned. In the first place, spelter is merely rather soft brass, and consequently it often cannot be fused without endangering the rest of the work. A good protection is a layer of fireclay laid upon the more delicate parts, such for instance as any screwed part. Gun-metal and tap-metal do not lend themselves to brazing so readily as iron or yellow brass, and are usually more conveniently treated by means of silver solder. Spelter tends to run very freely when it melts, and if the brass surface in the neighbourhood of the joint is at all clean, may run where it is not wanted. Of course some control may be exercised by "soiling" with fireclay or using an oxidising flame; but the erratic behaviour of spelter in this respect is the greatest drawback to its use in apparatus construction. The secret of success in brazing lies in properly cleaning up the work to begin with, and in disposing the borax so as to prevent subsequent oxidation. § 100. Silver Soldering. This process resembles that last described, but instead of spelter an alloy of silver, copper, and zinc is employed. The solder, as prepared by jewellers to meet special cases, varies a good deal in composition, but for the laboratory the usual proportions are: For soft silver solder Fine silver 2 parts Brass wire 1 part For hard silver solder Sterling silver 3 parts Brass wire 1 part The latter is, perhaps, generally the more convenient. Silver solders may, of course, be purchased at watchmakers' supply shops, and as thus obtained, are generally in thin sheet. This is snipped fine with a pair of shears preparatory to use. As odds and ends of silver (from old anodes and silver residues) generally accumulate in the laboratory, it is often more convenient to make the solder one's self. In this case it must be remembered in making hard solder by the second receipt that standard silver contains about one-twelfth of its weight of copper--exactly 18 parts copper to 220 silver. The silver is first melted in a plumbago crucible in a small furnace together with a little borax; if any copper is required this is then added, and finally the brass is introduced. When fusion is complete, the contents of the crucible are poured into any suitable mould. The quickest and most convenient way of preparing the alloy for use is to convert it into filings with the assistance of a coarse file, or by milling it, if a milling machine is available. Equal volumes of filings and powdered glass borax are made into a thin paste with water, and applied in an exactly similar manner to that described under the head of "brazing." In fact all the processes there described may be applied equally to the case under discussion, the substitution of silver for spelter being the only variation. The silver solder is more manageable than spelter, and does not tend to run wild over the work: a property which makes it much more convenient both for delicate joints and in cases where it is desired to restrict the solder to a single point or line. Small objects are almost invariably soldered with silver solder, and are held by forceps or on charcoal in the pointed flame of an ordinary blow-pipe. § 101. On the Construction of Electrical Apparatus: Insulators. It is not intended to deal in any way with the design of special examples of electrical apparatus, but merely to describe a rather miscellaneous set of materials and processes constantly required in its construction. It is not known whether there is such a thing as a perfect insulator, even if we presuppose ideal circumstances. Materials as they exist must be regarded merely as of high specific resistance, that is if we allow ourselves to use such a term in connection with substances, conduction through which is neither independent of electromotive force per unit length, nor of previous history. Even the best of these substances generally get coated with a layer of moisture when exposed to the air, and this as a rule conducts fairly well. Very pure crystalline sulphur and fused quartz suffer from this defect less than any other substances with which the writer is acquainted, but even with them the surface conductivity soon grows to such an extent as totally to mask the internal conduction. It is proposed to give a brief account of the properties of some insulating substances and their application in electrical construction, and at the same time to indicate the appliances and methods requisite for working them. With regard to the specific resistances which will be quoted, the numbers must not be taken to mean too much, partly for the reason already given. It is also in general doubtful whether sufficient care has been taken to distinguish the body from the surface conductivity, and consequently numerical estimates are to be regarded with suspicion. The question of "sampling" also arises, for it must be remembered that a change in composition amounting to, say, 1/10000 per cent may be accompanied by a million-fold change in specific resistance. § 102. Sulphur. This element exists in several allotropic forms, which have very different electric properties. After melting at about 125° C, and annealing at 110° for several hours, the soluble crystalline modification is formed. After keeping for some days--especially if exposed to light--the crystals lose their optical properties, but remain of the same melting-point, and are perfectly soluble in carbon bisulphide. The change is accompanied by a change in colour, or rather in brightness, as the transparency changes. The "specific resistance" of sulphur in this condition is above 1028 C.G.S.E.M. units, or 1013 megohms per cubic centimetre for an electric intensity of say 12,000 volts per centimetre. This is at ordinary temperatures. At 75° C. the specific resistance falls to about 1025 under similar conditions as to voltage. In all cases the conductivity appears to increase with the electric intensity, or at all events with an increase in voltage, the thickness of the layer of sulphur remaining the same. The specific inductive capacity is 3.162 at ordinary temperatures, and increases very slightly with rise of temperature. [Footnote: March 1897.--It is now the opinion of the writer that though the specific inductive capacity of a given sample of a solid element is perfectly definite, yet it is very difficult to obtain two samples having exactly the same value for this constant, even in the case of a material so well defined as sulphur.] The total residual charge, after ten minutes' charging with an intensity of 12,000 volts per centimetre, is not more than 4 parts in 10,000 of the original charge. In making this measurement the discharge occupied a fraction of a second. The electric strength for a homogeneous plate of crystalline sulphur is not less than 33,000 volts per centimetre, and probably a good deal more. If the sulphur is contaminated with up to 3 per cent of the amorphous variety, as is the case if it is cooled fairly quickly from a temperature of 170° C. or over, the specific resistance falls to from 10^25 to 10^26 at ordinary temperatures; and the specific inductive capacity increases up to 3.75, according to the amount of insoluble sulphur present. The residual charge under circumstances similar to those described above, but with an intensity of about 4000 volts per centimetre is, say, 2 per cent of the initial charge. So far as the writer is aware sulphur is the only solid non-conductor which can be easily obtained in a condition of approximate purity and in samples sufficiently exactly comparable with one another; it is the only one, therefore, that repays any detail of description. Very pure sulphur can be bought by the ton if necessary from the United Alkali Company of Newcastle-on-Tyne. It is recovered from sulphur waste by the Chance process, which consists in converting the sulphur into hydrogen sulphide, and burning the latter with insufficient air for complete combustion. The sulphur is thrown out of combination, and forms a crystalline mass on the walls and floor of the chamber. The sulphur which comes into the market consists of this mass broken up into convenient fragments. In order to purify it sufficiently for use as an insulator, the sulphur may be melted at a temperature of 120° to 140° C, and filtered through a plug of glass wool in a zinc funnel; as thus prepared it is an excellent insulator. To obtain the results mentioned in the table it is, however, necessary to conduct a further purification (chiefly from water) by distillation in a glass retort. The sulphur thus obtained may be cast of any desired form in zinc moulds, the castings and moulds being immediately removed to an annealing oven at a temperature of from 100° to 110° C, where they are left for several hours. If the sulphur is kept melted for some time at 125° C. the annealing is not so important. The castings may be removed from the mould by slightly heating the latter, but many breakages result. Insulators made on this plan are much less affected by the condensation of moisture from the air than anything except fused quartz. They are, however, very weak mechanically, and apt to crack by exposure to such changes of temperature as go on from day to day. It is clear, however, that in spite of this their magnificent electrical properties fit them for many important uses. If the sulphur be cooled rapidly from 170° C. or over, a mixture of the crystalline and amorphous varieties of sulphur is obtained. This mixture is very much stronger and tougher than the purely crystalline substance, and may be worked with ordinary hardwood tools into fairly permanent plates, rods, etc. Sheets of pure thick filter paper may also be dipped into sulphur at 170° C, at which temperature air and moisture are mostly expelled, and such sheets show a very considerable insulating power. The sulphur does not penetrate the paper, which therefore merely forms a nucleus. Cakes of the crystalline or mixed varieties may be made by grinding up some purified sulphur, moistening it with redistilled carbon bisulphide, or toluene, or even benzene (C6H6), and pressing it in a suitable mould under the hydraulic press. The plates thus formed are porous, but are splendid insulators, especially if made from the crystalline variety of sulphur, and they appear to keep their shape very well, and do not crack with ordinary temperature changes. The metals which resist the action of sulphur best are gold and aluminium; while platinum and zinc are practically unacted upon at temperatures below a red heat--in the former case,--and below the boiling-point of sulphur in the latter. A very convenient test of the purity of sulphur is the colour assumed by it when suddenly cooled from the temperature at which it is viscous. Quite pure sulphur remains of a pale lemon yellow under this treatment, but the slightest trace of impurity, such as arises from dust containing organic matter, stains the sulphur, and renders it darker in colour. § 103. Fused Quartz. This is on the whole the most reliable and most perfect insulator for general purposes. No exact numerical data have been obtained, but the resistivity must certainly be of the same order as that of pure sulphur at its best. The influence of the moisture of the air also reaches its minimum in the case of quartz, as was originally observed by Boys. As yet, however, the material can only be obtained in the form of rods or threads. For most purposes rods of about one-eighth of an inch in diameter are the most convenient. These rods may be used as insulating supports, and succeed perfectly even if they interpose less than an inch of their length to electrical conduction. The sketch (Figs. 81 and 81A) shows (to a scale of about one-quarter full size) a complete outfit for elementary electrostatic experiments, such as has been in use in the writer's laboratory for five years. With these appliances all the fundamental experiments may be performed, and the apparatus is always ready at a moment's notice. Fig. 81. Though quartz does not condense moisture or gas to form a conducting layer of anything like the same conductivity as in the case of glass or ebonite, still it is well to heat it if the best results are to be obtained. For this purpose a small pointed blow-pipe flame may be used, and the rods may be got red-hot without the slightest danger of breaking them. They then remain perfectly good and satisfactory for several hours at least, even when exposed to damp and dusty air. The rods are conveniently held in position by small brass ferrules, into which they are fastened by a little plaster of Paris. Sealing-wax must be avoided, on account of the inconvenience it causes when the heating of the rods is being carried out. One useful application of fused quartz is to the insulation of galvanometer coils (Fig. 82), another to the manufacture of highly insulating keys (Fig. 83); while as an insulating suspension it has all the virtues. If it is desired to render the threads conducting they may be lightly silvered, and will be found to conduct well enough for electrometer work before the silver coating is thick enough to sensibly impair their elastic properties. Fig. 81A. Fig. 82 is a full-size working drawing of a particular form of mounting for galvanometer coils. The objects sought to be attained are: (1) high insulation of the coils, (2) easy adjustment of the coils to the suspended system. The first object is attained as follows. The ebonite ring A is bored with four radial holes, through which are slipped from the inside the fused quartz bolt-headed pins B. The coil already soaked in hard paraffin is placed concentrically in the ring A by means of a special temporary centering stand. The space between the coil and the ring is filled up with hard paraffin, and this holds the quartz pins in position. The system of ebonite ring, coil, and pins is then fastened into the gun-metal coil carrier, which is cut away entirely, except near the edges, where it carries the pin brackets C. These brackets can swivel about the lower fastening at E before the latter is tightened up. The coil is now adjusted in the adjusting stand to be concentric with the axis of symmetry of the coil carrier, and the supporting pins are slipped into slot holes cut in the brackets, the brackets being swivelled as much as necessary to allow of this. When the pins are all inserted the brackets are screwed up by the screws at E. The pins are then cemented firmly to the brackets by a little plaster of Paris. The coil carrier can now be adjusted to the galvanometer frame by means of screws at D, which pass through wide holes in the carrier and bold the latter in position by their heads. In the sectional plan the parts of the galvanometer frame are shown shaded. The front of the frame at F F is of glass, and the back of the frame is also made of glass, though this is not shown in the section. A represents an ebonite ring into which the wire coil is cemented by means of paraffin. B B B B are quartz pins, with heads inside the ebonite ring. C C C are slotted brackets adjustable to the pins and capable of rotation by releasing the screws E E. D D are the screws holding the coil carriage to the galvanometer framework. These screws pass through large holes in the carriage so as to allow of some adjustment. Fig. 82. Fig. 83. § 104. Glass. When glass is properly chosen and perfectly dry it has insulating properties possibly equal to those possessed by quartz or crystalline sulphur. For many purposes, however, its usefulness is seriously reduced by the persistence with which it exhibits the phenomena of residual charge, and the difficulty that is experienced in keeping it dry. The insulating power of white flint glass is much in excess of that of soft soda glass, which is a poor insulator, and of ordinary green bottle glass. The jars of Lord Kelvin's electrometers, which insulate very well, are made of white flint glass manufactured in Glasgow, but it is found that occasionally a particular jar has to be rejected on account of its refusing to insulate, and this, if I understand aright, even when it exhibits no visible defects. A large number of varieties of glass were tested by Dr. Hopkinson at Messrs. Chance Bros. Works, in 1875 and 1876 (Phil. Trans, 1877), and in 1887 (Proc. Roy. Soc. xli. 453), chiefly with a view to the elucidation of the laws regulating the residual charge; and incidentally some extraordinarily high insulations were noted among the flint glasses. The glass which gave the smallest residual charge was an "opal" glass; and flint glasses were found to insulate 105 times as well as soda lime glasses. The plates of Wimshurst machines are made of ordinary sheet window glass, but as the insulating property of this material appears to vary, it is generally necessary to clean, dry, and test a sheet before using it. With regard to hard Bohemian glass, this is stated by Koeller (Wien Bericht) to insulate ten times as well as the ordinary Thuringian soft soda glass. On the whole the most satisfactory laboratory practice is to employ good white flint glass. The only point requiring attention is the preparation of the glass by cleaning and drying. Of course all grease or visible dirt must be removed as described in an earlier chapter (§ 13), but this is only a beginning. The glass after being treated as described and got into such a state as to its surface that clean water no longer tends to dry off unequally, must be subjected to a further scrub with bibulous paper and a clear solution of oleate of soda. The glass is then to be well rinsed with distilled water and allowed to drain on a sheet of filter paper. A very common cause of failure lies in the contamination of the glass with grease from the operator's fingers. Before setting out to clean the glass the student will do well to wash his hands with soap and water, then with dilute ammonia and finally with distilled water. In the case of an electrometer jar which has become conducting but is not perceptibly dirty, rubbing with a little oleate of soda and a silk ribbon, followed, of course, by copious washing, does very well. If there is any tin-foil on the jar, great care must be taken not to allow the glass surface to become contaminated by the shellac varnish or gum used to stick the tin-foil in position. Finally, the glass should be dried by radiant heat and raised to a temperature of 100° C. at least, and kept at it for at least half an hour. Before drying it is of course advisable to allow the water to drain away as far as possible, and if the water is only the ordinary distilled water of the laboratory, the glass is preferably wiped with a clean bit of filter paper; any hairs which may be left upon the glass will brush off easily when the glass is dry. In order to obtain satisfactory results the glass must be placed in dry air before it has appreciably cooled. This is easily done in the case of electrometer jars, and so long as the air remains perfectly dry through the action of sulphuric acid or phosphorus pentoxide, the jar will insulate. The slightest whiff of ordinarily damp air will, however, enormously reduce the insulating power of the glass, so that unvarnished glass surfaces must be kept for apparatus which is practically air-tight. For outside or imperfectly protected uses the glass does better when varnished. It is a fact, however, that varnished glass is rarely if ever so good as unvarnished glass at its best. Too much care cannot be taken over the preparation of the varnish; French polish, or carelessly made shellac varnish, is likely to do more harm than good. The best orange shellac must be dissolved in good cold alcohol by shaking the materials together in a bottle. The alcohol is made sufficiently pure by starting with rectified spirit and digesting it in a tin flask over quick-lime for several days, a reversed condenser being attached. A large excess of lime must be employed, and this leads to a considerable loss of alcohol, a misfortune which must be put up with. After, say, thirty hours' digestion, the alcohol may be distilled off and employed to act on the shellac. In making varnish, time and trouble are saved by making a good deal at one operation--a Winchester full is a reasonable quantity. The bottle may be filled three-quarters full of the shellac flakes and then filled up with alcohol; this gives a solution of a convenient strength. The solution, however, is by no means perfect, for the shellac contains insoluble matter, and this must be got rid off.`' One way of doing this is to filter the solution through the thick filtering paper made by Schleicher and Schuell for the purpose, but the filtering is a slow process, and hence requires to be conducted by a filter paper held in a clip (not a funnel) under a bell jar to avoid evaporation. Another and generally more convenient way in the laboratory is to allow the muddy varnish to settle--a process requiring at least a month--and to decant the clear solution off into another bottle, where it is kept for use. The muddy residue works up with the next lot of shellac and alcohol, which may be added at once for future use. The glass to be varnished is warmed to a temperature of, say, 50° C, and the varnish put on with a lacquering brush; a thin uniform coat is required. The glass is left to dry long enough for the shellac to get nearly hard and to allow most of the alcohol to evaporate. It is then heated before a fire, or even over a Bunsen, till the shellac softens and begins to yield its fragrant characteristic smell. If the coating is too heavy, or if the heating is commenced before the shellac is sufficiently dry, the latter will draw up into "tears," which are unsightly and difficult to dry properly. On no account must the shellac be allowed to get overheated. If the varnish is not quite hard when cold it may be assumed to be doing more harm than good. In varnishing glass tubes for insulating purposes it must be remembered that the inside of the tube is seldom closed perfectly as against the external air, and consequently it also requires to be varnished. This is best done by pouring in a little varnish considerably more dilute than that described, and allowing it to drain away as far as possible, after seeing that it has flooded every part of the tube. During this part of the process the upper end of the tube must be closed, or evaporation will go on so fast that moisture will be deposited from the air upon the varnished surface. Afterwards the tube may be gently warmed and a current of air allowed to pass, so as to prevent alcohol distilling from one part of the tube to another. The tube is finally heated to the softening point of shellac, and if possible closed as far as is practicable at once. § 105. Ebonite or Hard Rubber. This exceedingly useful substance can be bought of a perfectly useless quality. Much of the ebonite formerly used to cover induction coils for instance, deteriorates so rapidly when exposed to the air that it requires to have its surface renewed every few weeks. The very best quality of ebonite obtainable should be solely employed in constructing electric works. It is possible to purchase good ebonite from the Silvertown Rubber Company (and probably from other firms), but the price is necessarily high, about four shillings per pound or over. At ordinary temperatures ebonite is hard and brittle and breaks with a well-marked conchoidal fracture. At the temperature of boiling water the ebonite becomes somewhat softened, so that it is readily bent into any desired shape; on cooling it resumes its original hardness. This property of softening at the temperature of boiling water is a very valuable one. The ebonite to be bent or flattened is merely boiled for half an hour or so in water, taken out, brought to the required shape as quickly as possible, and left to cool clamped in position. The sheet ebonite as it comes from the makers is generally far from flat. It is often necessary to flatten a sheet of ebonite, and of course this is the more easily accomplished the smaller the sheet. Consequently a bit of ebonite of about the required size is first cut from the stock sheet by a hack-saw such as is generally used for metals. This piece is then boiled and pressed between two planed iron plates previously warmed to near 100° C. With pieces of ebonite such as are used for the tops of resistance boxes, measuring, say, 20 X 8 X 11 inches, very little trouble is experienced. The sheets when cold are found to retain the flatness which has been forced upon them perfectly well. It is otherwise with large thin sheets such as are used for Holtz machines. I have succeeded fairly, but only fairly, by pressing them in a "gluing press," consisting of heavy planed iron slabs previously heated to 100° C. I do not know exactly how best to flatten very thin and large sheets. It is easy to make large tubes out of sheet ebonite by taking advantage of the softening which ebonite undergoes in boiling water. A wooden mandrel is prepared of the proper size and shape. The ebonite is softened and bent round it; this may require two or three operations, for the ebonite gets stiff very quickly after it is taken out of the water. Finally the tube is bound round the mandrel with sufficient force to bring it to the proper shape and boiled in water, mandrel and all. The bath and its contents are allowed to cool together, so that the ebonite cools uniformly. Tubes made in this way are of course subject to the drawback of having an unwelded seam, but they do well enough to wind wire upon if very great accuracy of form is not required. If very accurate spools are needed the mandrel is better made of iron or slate and the spool is turned up afterwards. The seam may be strapped inside or at the ends by bits of ebonite acting as bridges, and the seam itself may be caulked with melted paraffin or anthracene. Working Ebonite. Ebonite is best worked as if it were brass, with ordinary brass-turning or planing tools. These tools should be as hard as possible, for the edges are apt to suffer severely, and blunt tools leave a very undesirable woolly surface on the ebonite. In turning or shaping ebonite sheets it is as well to begin by taking the skin off one side first, and then reversing the sheet, finishing the second side, and then returning to the first. This is on account of the fact that ebonite sometimes springs a little out of shape when the skin is removed. Turned work in ebonite, if well done, requires no sand-papering, but may be sufficiently polished by a handful of its own shavings and a little vaseline. The advantage of using a polished ebonite surface is that such a surface deteriorates more slowly under the influence of light and air than a surface left rough from the tool. If very highly polished surfaces are required, the ebonite after tooling is worked with fine pumice dust and water, applied on felt, or where possible by means of a felt buff on the lathe, and finally polished with rouge and water, applied on felt or cloth. Ebonite works particularly well under a spiral milling cutter, and sufficiently well under an ordinary rounded planing tool, with cutting angle the same as for brass, and hardened to the lightest straw colour. It is not possible, on the other hand, to use the carpenter's plane with success, for the angle of the tool is too acute and causes the ebonite to chip. In boring ebonite the drill should be withdrawn from the hole pretty often and well lubricated, for if the borings jam, as they are apt to do, the heat developed is very great and the temper of the drill gets spoiled. Ebonite will spoil a drill by heating as quickly as anything known; on the other hand, it may be drilled very fast if proper precaution is taken. It is advisable to expose ebonite to the light as little as possible, especially if the surface is unpolished, for under the combined action of light and air the sulphur at the surface of the ebonite rapidly oxidises, and the ebonite becomes covered with a thin but highly conducting layer of sulphurous or sulphuric acid or their compounds. When this happens the ebonite may be improved by scrubbing with hot water, or washing freely with alcohol rubbed on with cotton waste in the case of apparatus that cannot be dismounted. A complete cure, however, can only be effected by scraping off the outer layer of ebonite so as to expose a fresh surface. For this purpose a bit of sheet glass broken so as to leave a curved edge is very useful, and the ebonite is then scraped like a cricket bat. In designing apparatus for laboratory use it is as well to bear in mind that sooner or later the ebonite parts will require to be taken down and scraped up. Rods or tubes are, of course, most quickly treated on the lathe with rough glass cloth, and may be finished with fine sandpaper, then pumice dust and water, applied on felt. After cleaning the pumice off by means of water and a rag, the final touch may be given by means of vaseline, applied on cloth or on ebonite shavings. § 106. Mica. A great variety of minerals go under this name. Speaking generally, the Russian micas coming into commerce are potash micas, and mica purchased in England may be taken to be potash mica, especially if it is in large sheets. At ordinary temperatures "mica" of the kind found in commerce is an excellent insulator. Schultze (Wied. Ann. vol. xxxvi. p. 655) comes to the conclusion that both at high and at low temperatures mica (of all kinds?) is a better insulator than white "mirror glass," the composition of which is not stated. The experiments of the author referred to were apparently left unfinished, and altogether too much stress must not be laid on the results obtained, one of which was that mica conducts electrolytically to some extent at high temperatures. Bouty (Journal de Physique, 1890 [9], 288) and J. Curie (Thèse de Doctorat, Paris, 1888) agree in making the final conductivity of the mica used in Carpentier's condensers exceedingly small--at all events at ordinary temperatures. Bearing in mind that for such substances the term specific resistance has no very definite meaning, M. Bouty considers it is not less than 3.19 x 1028 E.M. units at ordinary temperatures. M. Bouty gives a note or illustration of what such numbers mean--a precaution not superfluous in cases where magnitudes are denoted logarithmically. Referring to the value quoted, viz. 3.19 x 1028, M. Bouty says, "Ce serait la resistance d'une colonne de mercure de 1mmq de section et de longueur telle que la lumière se propageant dans le vide, mettrait plus de 3000 ans A se transmettre d'une extrémité à I'autre de la colonne." M. Bouty returns to the study of mica (muscovite) in the Journal de Physique for 1892, p. 5, and there deals with the specific inductive capacity, which for a very small period of charge he finds has the value 8--an enormous value for such a good insulator, and one that it would be desirable to verify by some totally distinct method. This remark is enforced by the fact that M. Klemencic finds the number 6 for the same constant. The temperature coefficient of this constant was too small for M. Bouty to determine. The electric intensity was of the order of 100 volts per centimetre, and the experiments seem to indicate that the specific inductive capacity would be only slightly less if referred to a period of charge indefinitely short. I have found that the residual charge in a mica condenser, made according to Carpentier's method (to be described below), is about 1 per cent of the original charge under the following circumstances. Voltage 300 volts on a plate 0.2 mm. thick, duration of charge ten minutes, temperature about 20° C. To get this result the mica must be most carefully dried. This and other facts indicate that the so-called residual charge on ordinary condensers is, to a very large extent, due to the creeping of the charge from the armatures over the more or less conducting varnished surfaces of the mica, and its slow return on discharge. This source of residual charge was carefully guarded against by Rowland and Nichols (Phil. Mag. 1881) in their work on quartz, and is referred to by M. Bouty, who adduces some experiments to show that his own results are not vitiated by it. On the other hand, M. Bouty shows that a small rise in temperature enormously affects the state of a mica surface, and that the surface gets changed in such a way as to become very fairly conducting at 300° C. Also anybody can easily try for himself whether exposing a mica condenser plate which has been examined in presence of phosphorus pentoxide to ordinary air for five minutes will not enormously increase the residual charge, as has always been the case in the writer's experience, and if so, it is open to him to suggest some cause other than surface creeping as an explanation. M. Bouty, using less perfectly dried mica, did not get so good a result as to smallness of residual charge as the one above quoted. The chief use of mica for laboratory purposes depends on the ease with which it can be split, and also upon the fact that it may be considerably crumpled and bent without breaking. It therefore makes an excellent dielectric in so far as convenience of construction is concerned in the preparation of condensers, and lends itself freely to the construction of insulating washers or separators of any kind. Its success as a fair insulator at moderate temperatures has led to its use in resistance thermometers, where it appears to have given satisfaction up to, at all events, 400° C. It is worth a note that according to Werner Siemens, who had immense experience (Wied. Ann. vol. clix.), soapstone is the only reliable insulator at a red heat, but, no doubt, a good deal depends on the particular specimen investigated. § 107. Use of Mica in Condensers. If good results are desired it is essential to select the mica very carefully. Pieces appreciably stained,--particularly if the stain is not uniformly distributed,--cracked pieces, and pieces tending to flake off in patches should be rejected. The best samples of mica that have come under the writer's observation are those sheets sold for the purpose of giving to silver photographic prints that hideous glazed surface which some years ago was so popular. Sheets of mica about 0.1 to 0.2 mm. thick form good serviceable condenser plates, and will certainly stand a pressure of 300 volts, and most likely a good deal more. The general practice in England seems to have been to build up condensers of alternate sheets of varnished or paraffined-mica and tin-foil. This practice is open to several objections. In the first place, the capacity of a condenser made in this way varies with the pressure binding the plates together. In the second place, the amount of mica and tin-foil required is often excessive in consequence of the imperfect contact of these substances. Again, the inevitable air film between the mica and tin-foil renders condensers so made unsuitable for use with alternating currents, owing to the heating set up through air discharges, and which is generally, though often (if not always) wrongly, attributed to dielectric hysteresis. These imperfections are to a great extent got over by M. Carpentier's method of construction, which is, however, rather more costly both in material and labour. On the other hand, wonderful capacities are obtained with quite small amounts of mica. M. Bouty mentions a condenser of one microfarad capacity weighing 1500 grms. and contained in a square box measuring 12 centimetres on the side, and about 3 centimetres thick. The relation between the capacity and surface of doubly-coated plates is in electro-static units: Capacity = (sp. ind. capacity X area of one surface)/(4pi X thickness) This may be reduced to electro-magnetic units by dividing by 9x10^20, and to microfarads by further multiplying by 10^15. M. Carpentier begins, of course, by having his mica scrupulously clean and well selected. It is then silvered by one of the silvering processes (§ 65) on both sides, for which purpose the sheets may be suspended in a paraffined wood rack, so as to lie horizontally in the silvering solution, a space of about half an inch being allowed between the sheets. The silvering being finished, the sheets are dipped along two parallel edges in 75 per cent nitric acid. With regard to the third and fourth edges of the sheet, the silver is removed on one side only, using a spun glass brush; if we agree to call the two surfaces of the mica A and B respectively, and the two edges in question C and D, then the silver is removed from the A side along edge C, and from the B side along edge D. The silvered part is shown shaded in Fig. 84. By this arrangement the silver and mica plates may be built up together so as to form the same mutual arrangement of contacts as in an ordinary mica tin-foil condenser. Fig. 84. It need hardly be said that the sheets require very complete washing after treatment with nitric acid, followed by a varnishing of the edges as already described in the case of glass, and baking at a temperature of 140° C. in air free from flame gases, till the shellac begins to emit its characteristic odour and is absolutely hard when cold. The plates are then built up so as to connect the sheets which require to be connected, and to insulate the other set. General contact is, if necessary, secured by means of a little silver leaf looped across from plate to plate--a part of the construction which requires particular attention and clean hands, for it is by no means so easy to make an unimpeachable contact as might at first appear. The condenser, having been built up, may be clamped solid and placed in its case; the capacity will not depend appreciably on the tightness of the clamp screws--a great feature of the construction. Such a condenser will not give its best results unless absolutely dry. I have kept one very conveniently in a vacuum desiccator over phosphorus pentoxide, but if of any size, the condenser deserves a box to itself, and this must be air-tight and provided with a drying reagent, so arranged that it can be removed through a manhole of some sort. Contact to the brass-work on the lid may be made by pressing spring contacts tightly down upon the ends of the silver foils and carrying the connections through the lid. This also serves to secure the condenser in position. § 108. Micanite. This substance, though probably comparing somewhat unfavourably with the insulators already enumerated, and being subject to the uncertainties of manufacture, has during the last few years achieved a considerable success in American electrical engineering construction. It is composed of scrap mica and shellac varnish worked under pressure to the desired shape, and may be obtained in sheets, plates, and rods, or in any of the forms for which a die happens to have been constructed. Of course, in special cases it would be worth while to prepare a die, and then the attainable forms would be limited by moulding considerations only. The writer's experience is very limited in this matter, but Dr. Kennelly, with whom he communicated on the subject, was good enough to reply in favour of micanite for engineering work. § 109. Celluloid. This material is composed of nitrocellulose and camphor. It has fair insulating properties, and may be obtained in a variety of forms, but has now been generally abandoned for electrical work on account of its inflammability. § 110. Paper. Pure white filter paper, perfectly dry, is probably a very fair insulator; the misfortune is that in practice it cannot be kept dry. Under the most favourable circumstances its specific resistance may approach 1024 E.M. units. It must therefore be considered rather as a partial conductor than as an insulator. The only case of the use of dry paper as an insulator in machine construction which has come under the writer's notice is in building up the commutators of the small motors which used to drive the Edison phonographs. Its advantages in this connection are to be traced to the fact that a commutator so built up is durable and keeps a clean surface. Of course, the use of paper as an insulator for telephone wires is well known, but its success in this direction depends less upon its insulating properties than upon the fact that it can be arranged in such a way as to allow of the wires being partially air insulated, an arrangement tending to reduce the electrostatic capacity of the wire system. At one time it was the custom of instrument makers to employ ordinary printed paper in the shape of leaves torn from books or the folios of old ledgers to form the dielectric of the condensers used in connection with the contact breakers of induction coils. This practice has nothing but economy to recommend it, for cases often occur in which the paper, by gradual absorption of moisture from the air, comes to insulate so badly that it practically short circuits the spark gap, and so stops the action of the coil. Three separate cases have come within the writer's experience. Some measurements of the resistance of paper have been made by F. Uppenborn (Centralblatt fuer Electrotechnik, Vol. xi. p. 215, 1889). There is an abstract of the paper also in Wiedemann's Beiblaetter (1889, vol. xiii. P. 711). Uppenborn examined the samples of paper under normal conditions as to moisture and obtained the following results:- Description of Paper I Pressure Intensity II. Specific Resistance corresponding to pressures as in Column I. Ohms. III Pressure Intensity. IV. Specific Resistance corresponding to Column III. Ohms. Common cardboard 2.3 mm. thick 0.05 kilo. per 6000 sq. mm. 4.85 x 1015 20 kg. per 6000 sq. mm. 4.7 x 1014 Gray paper, 0.26 mm. thick 0.05 kilo. per 5000 sq. mm. 3.1 x 10^15 20 kg. per 5000 sq. mm. 8 x 1014 Yellow parchment paper-09 mm. thick 0.05 kilo. per 5300 sq. mm. 3.05 x 1016 20 kg. per 5300 sq. mm. 8 x 1016 Linen tracing cloth 0.05 kilo. per 6000 sq. mm. 1.35 x 1016 20 kg. per 33,000 sq. mm. 1.86 x 10^15 § 111. Paraffined Paper. Like wood and other semiconductors, paper can be vastly improved as an insulator by saturating it with melted paraffin. To get the best results a pure paper free from size must be employed--gray Swedish filter paper does well. This is dried at a temperature above 100° C. for, say, half an hour, and the sheets are then floated on the top of paraffin, kept melted at 140° C. or thereabout in a baking dish. As soon as the paper is placed upon the melted paraffin the latter begins to soak through, in virtue of capillary action, and drives before it the air and moisture, causing a strongly marked effervescence. After about one minute the paper may be thrust below the paraffin to soak. When a sufficient number of papers have accumulated, and when no more gas comes off, the tray may be placed in a vacuum box (Fig. 85), and the pressure reduced by the filter pump. As the removal of the air takes time, provision must be made for keeping the bath hot. A vacuum may be maintained for about an hour, and air then readmitted. Repeated exhaustions and readmissions of air, which appear to improve wood, do not give anything like such a good result with paper. In using a vacuum box provision must be made in the shape of a cool bottle between the air pump and the box. If this precaution be omitted, and if any paraffin splashes on to the hot surface of the box, it volatilises with decomposition and the products go to stop up the pump. Paraffin with a melting-point of 50° C. or upwards does well. The bath should be allowed to cool to about 60° C. before the papers are removed, so that enough paraffin may be carried out to thoroughly coat the paper and prevent the entrance of air. Fig. 85. Fig. 85 is a section of a vacuum vessel which has been found very convenient. It measures about two feet in diameter at the top. It is round, because it is much easier to turn one circular surface than to plane up four surfaces, which has to be done if the box is square. Both the rim of the vessel and the approximating part of the cover require to be truly turned and smoothly finished. A very good packing is made of solid indiarubber core about half an inch thick. This is carefully spliced--cemented by means of a solution of rubber in naphtha, and the splice sewed by thick thread. The lid ought to have a rim fitting inside the vessel, for this keeps the rubber packing in place; the rim has been accidentally omitted in Fig. 85. The bolts should not be more than five inches apart, and should lie at least half an inch in diameter, and the rim and lid should be each half an inch thick. Condensers may now be built up of sheets of this prepared paper interleaved with tin-foil in the ordinary way. If good results are required, the condenser when finished is compressed between wooden or glass end-pieces by means of suitable clamps. It can then be put in a box of melted paraffin, heated up to 140° C, and exhausted by means of the water pump for several hours. In this process the air rushes out from between the paper and foils with such vehemence that the paraffin is generally thrown entirely out of the box. To guard against this the box must be provided with a loosely fitting and temporary lid, pierced with several holes. The real test as to when exhaustion is complete would be the cessation of any yield of air or water. Since it is not generally convenient to make the vacuum box so air-tight that there are absolutely no leaks at all, and as the paraffin itself is, I think, inclined to "crack" slightly at the temperature of 140° C, this test or criterion cannot be conveniently applied. Two exhaustions, each of about two hours' duration, have, however, in my experience succeeded very well, provided, of course, that the dielectric is prepared as suggested. At the end of the exhaustion process the clamping screws are tightened as far as possible, the condenser remaining in its bath until the paraffin is pasty. Condensers made in this way resist the application of alternating currents perfectly, as the following tests will show. The dielectric consisted of about equal parts of hard paraffin and vaseline. A condenser of about 0.123 microfarads capacity and an insulation resistance of 2000 megohms, [Footnote: As tested by a small voltage.] having a tin-foil area of 4.23 square metres (about), and double papers each about 0.2 mm. thick, designed to run at 2000 volts with a frequency of 63 complete periods, was tested at this frequency. The condenser was thoroughly packed all round in cotton-wool to a thickness of 6 inches, and its temperature was indicated more or less by a thermometer plunged through a hole in the lid of the containing box and of the condenser box, and resting on the upper surface of one set of tin-foil electrodes, from which the soft paraffin mixture had been purposely scraped away. The following were the results of a four hours' run at a voltage 50 per cent higher than that for which the condenser was designed--i.e. 3000 volts. Times. Voltage Temperature Temperature Difference in Condenser. in Air. Hrs. Min. 2 10 2750 22.8° C. 23.0° C. + 0.2° 3 10 2700 23.0° C. 23.3° C. + 0.3° 3 18 3200 23.1° C. 23.0° C. -0.1° 4 10 3200 23.3° C. 23.7° C. + 0.4° 5 10 3100 23.6° C. 23.4° C. -0.2° 6 10 3000 23.8° C. 23.35° C. -0.45° An idea of the order of the amount of waste may be formed from the following additional experiment. A condenser similar to the one described was filled with oil of a low insulating power. It was tested calorimetrically, and also by the three voltmeter method, which, however, proved to be too insensitive. The temperature rise in the non-conducting box in air was about 0.3° C. per hour, and the loss of power was found to be less than 0.1 per cent. In the present case the actual rise was only 1° in four hours, and the integral give and take between the condenser and the air is practically nothing; consequently we may consider with safety that the rate of rise is certainly less than 1 degree per three hours. The voltage and frequency were about the same in both experiments, consequently the energy passed is about proportional to the capacity used in the two experiments. From this it follows that since the specific heat of both condensers was the same (nearly), the loss in the present case is a good deal less than one-tenth per cent. The residual charge is also much less than when the condenser is simply built up of paper paraffined in an unsystematic manner, and from which the air and water have been imperfectly extracted, as by baking the condenser first, and then immersing it in paraffin or oil. It is usual to consider that the phenomena of residual charge and heating in condensers, to which alternating voltages are applied, are closely allied. This is true, but the alliance is not one between cause and effect--at all events, with regard to the greater part of the heating. The imperfect exclusion of air and moisture, particularly the latter, certainly increases the residual charge by allowing surface creeping to occur; but it also acts directly in producing heating, both by lowering the insulation of the condenser and by allowing of air discharges between the condenser plates. Of these causes of heating, the discharges in air or water vapour are probably the more important. Long ago a theory of residual charge was given by Maxwell, based on the consideration of a laminated dielectric, the inductivity and resistance of which varied from layer to layer. It was shown that such an arrangement, and hence generally any want of homogeneity in a direction inclined to the lines of force leading to a change of value of the product of specific resistance and specific inductive capacity, would account for residual charge. This possible explanation has been generally accepted as the actual explanation, and many cases of residual charge attributed to want of homogeneity, which are certainly to be explained in a simpler manner. For instance, the residual charge in a silvered mica plate condenser, carefully dried, can be increased at least tenfold by an exposure of a few minutes to ordinarily damp air. The same result occurs with condensers of paraffined or sulphured paper; and these are the residual changes generally observed. The greater part must be due to creeping. § 112. Paraffin. This substance has long enjoyed great popularity in the physical laboratory. Its specific resistance is given by Ayrton and Perry as more than 1025, but it is probably much higher in selected samples. The most serviceable kind of paraffin is the hardest obtainable, melting at a temperature of not less than 52° C. It is a good plan to remelt the commercial paraffin and keep it at a temperature of, say, 120° C. for an hour, stirring it carefully with a glass rod so that it does not get overheated; this helps to get rid of traces of water vapour. Hard paraffin, when melted, has an enormous rate of expansion with temperature, so great, indeed, that care must be taken not to overfill the vessels in which it is to be heated. Castings can only be prepared by cooling the mould slowly from the bottom, keeping the rest of the mould warm, and adding-paraffin from time to time to make up for the contraction. The cooling is gradually allowed to spread up to the free surface. The chief use of paraffin in the laboratory is in the construction of complicated connection boards, which are easily made by drilling holes in a slab of paraffin, half filling them with mercury, and using them as mercury cups. Since paraffin is a great collector of dust, it should be screened by paper, otherwise the blocks require to be scraped at frequent intervals, which, of course, electrifies them considerably. This electrification is often difficult to remove without injuring the insulating power of the paraffin. A light touch with a clean Bunsen flame is the readiest method, and does not appear to reduce the insulation so much as might be expected. The safest way, however, is to leave the key covered by a clean cloth, which, however, must not touch the surface, for a sufficient time to allow of the charges getting away. The paraffin often becomes electrified itself by the friction of the key contacts, so that in electrometer work it is often convenient to form the cups by lining them with a little roll of copper foil twisted up at the bottom. In this case the connecting wires should, of course, be copper. Small steel staples are convenient for fastening the collecting wires upon the paraffin; or, in the case where these wires have to be often removed and changed about, drawing-pins are very handy. With mercury cups simply bored in paraffin great trouble will often be experienced in electrometer work, owing to a potential difference appearing between the cups--at all events when the contacts are inserted and however carefully this be done. A few drops of very pure alcohol poured in above the mercury often cures this defect. The surface of paraffin is by no means exempt from the defect of losing its insulating power when exposed to damp air, but it is not so sensitive as glass, nor does the insulating power fall so far. Two useful appliances are figured. Fig. 86. Fig. 87. One, in which paraffin appears as a cement, is an insulating stand made out of a bit of glass or ebonite tube cemented into an Erlenmeyer flask, having its neck protected from dust when out of use by a rubber washer, the other a "petticoat" insulator made by cementing a flint glass bottle into a glass dish with paraffin. In course of time the paraffin will be found to have separated from the glass. When this occurs the apparatus may be melted together again by placing it on the water bath for a few minutes. § 113. Vaseline, Vaseline Oil, and Kerosene Oil. These, when dry, insulate almost, but not quite as well as solid paraffin. H. Koeller (Wien Berichte, 98, ii. 201, 1889; Beibl. Wied. Ann. 1890, p. 186), working with very small voltages, places the final(?) specific resistance of commercial petroleum, ether, and vaseline oil at about 2 X 1027 C.G.S. This is ten times higher than the value assigned to commercial benzene (C6H6), and a hundred times higher than the value for commercial toluene. All these numbers mean little or nothing, but the petroleum and vaseline oil were the best fluid insulators examined by Koeller. By mixing vaseline with paraffin a soft wax may be made of any desired degree of softness, and by dissolving vaseline in kerosene an insulating liquid of any degree of viscidity may be obtained. Hard paraffin may be softened somewhat by the addition of kerosene, and an apparently homogeneous mass cast from the mixture. It will be found, however, that in course of time the kerosene oozes out, unless present in very small quantity. Koeller has found (loc. cit.) that some samples of vaseline oil conducted "vollstaendig gut," but I have not come across such samples. Vaseline oil, however, is sold at a price much above its value for insulating purposes. Kerosene oil is best obtained dry by drawing it directly from a new tin and exposing it to air as little as possible. Of course, it may be dried by chemical means and distillation, but this is usually (or always) unnecessary. Fig 88. There is some danger of kerosene containing minute traces of sulphuric acid, and it and other oils may be conveniently tested for insulation in the following manner. The quartz electroscope is taken, and the insulating rod heated in the blow-pipe. The electroscope will now insulate well enough to show no appreciable collapse of the leaves in one or two hours' time. Upon the plate of the electroscope is put a platinum or copper cylinder, and this is filled with kerosene (say) up to a fixed mark. The electroscope is placed on a surface plate, or, at all events, on a sheet of plate glass, and a "scribing block" is placed along side it and the scriber adjusted to dip into the kerosene to any required depth. This is done by twisting a bit of wire round the scribing point and allowing it to project downwards. The point itself serves to give an idea of the height to which the vessel may be filled. The liquid is adjusted till its surface is in contact with the end of the scribing point, and the wire then projects into the liquid and forms an electrode of constant area of surface. The scribing block is put to earth. A charge is given to the electroscope, and the time required for a given degree of collapse of the leaves noted. The kerosene is then removed and its place taken by vaseline or paraffin, known to insulate well as a standard for comparison. The experiment is then repeated, and the time noted for the same degree of collapse. This test, though of course rough, is generally quite sufficient for workshop purposes, and is easily applied. Moreover, it does not require correction for electrometer leakage, as generally happens when more elaborate appliances are used. The actual resistance of insulating oils depends so much on the electrical intensity, on the duration of that intensity, and on the previous history of the oil as to the direction of the voltage to which it has been subjected--to say nothing of the effects of traces of moisture--that quantitative experiments are of no value unless they are extremely elaborate. I shall therefore only append the following numbers due to Bouty, Ann. de Chemie et de Physique (6), vol. xxvii. p. 62, 1892, in which the effect of the conductivity on the determination of the specific inductive capacity was properly allowed for:- Carbon Bisulphide. Turpentine. Benzene (C6H6) at 20° C. Benzene at 60° C. Specific inductive capacity 2.715 2.314 2.21 2.22 Specific resistance in ohms per cubic centimetre 1.5 x 1013, 1.75 x 1012 1.56 x 1011 7.9 x 1011 [Footnote: Professor J. J. Thomson, and Newall (Phil. Proc. 1886) consider that carbon bisulphide showed traces of a "residual charge" effect; hence, until this point is cleared up, we must regard Bouty's value as corresponding only to a very short, but not indefinitely short, period of charge. On this point the paper must be consulted. March 1897--The writer has investigated this point by an independent method, but found no traces of "residual charge."] Information as to the specific inductive capacity of a large number of oils may be found in a paper by Hopkinson, Phil. Proc. 1887, and in a paper by Quincke in Wiedemann's Annalen, 1883. § 114. Imperfect Conductors. Under this heading may be grouped such things as wood, slate, marble, etc--in fact, materials generally used for switchboard insulation. An examination of the insulating power of these substances has recently been made by B. O. Peirce (Electrical Review, 11th January 1895) with quite sufficient accuracy, having in view the impossibility of being certain beforehand as to the character of any particular sample. The tests were made by means of holes drilled in slabs of the material to be examined. These holes were three-eighths of an inch in diameter, and from five-eighths to three-quarters of an inch deep, and one inch apart, centre to centre. A voltage of about 15 volts was employed. The following general results were arrived at:- (1) Heating in a paraffin bath always increases the resistance of wood, though only slightly if the wood be hard and dense. (2) Frequent exhaustion and readmission of air above the surface of the paraffin always has a good effect in increasing the resistance of wood. (3) When wood is once dry, impregnating it with paraffin tends to keep it dry. (4) Red vulcanised fibre, like wood, absorbs paraffin, but it cannot be entirely waterproofed in this way. (5) The resistance of wood with stream lines along the grain is twenty to fifty per cent lower than when the stream lines cross the grain. (6) The "contact" resistance between slabs of wood pressed together is always very high. The following table will sufficiently illustrate the results obtained. The stone was dried in the sun for three weeks in the summer (United States), and the wood is described as having been well seasoned:- CURRENT WITH THE GRAIN Lowest Resistance Highest Resistance Lowest Specific Highest Specific between two Cups between two Cups Resistance in Resistance in in Megohms. in Megohms. Megohms. Megohms. Ash. 550 920 380 700 Cherry 1100 4000 2800 6000 Mahogany 430 730 310 610 Oak 220 420 1050 2200 Pine. 330 630 360 1470 Hard pine. 10 48 17 1050 Black walnut 1100 3000 320 2100 Red fibre 2 4 3 60 Slate 184 280 Soapstone. 330 500 White marble 2000 8800 § 115. As to working the materials very little need be said. Fibre is worked like wood, but has the disadvantage of rapidly taking the edge off the tools. In turning it, therefore, brass-turning tools, though leaving not quite such a perfect finish as wood-turning tools, last much longer, and really do well enough. Fibre will not bear heating much above 100°C--at all events in paraffin. At 140° C. it becomes perfectly brittle. Its chief merit lies in its great strength. So far as insulation is concerned, Mr. Peirce's experiments show that it is far below most kinds of wood. Slate. This is a vastly more useful substance than it is generally credited with being. It is very easily worked at a slow speed, either on the shaping machine or on the lathe, with tools adjusted for cutting brass, and it keeps its figure, which is more than can be said for most materials. It forms a splendid base for instruments, especially when ground with a little emery by iron or glass grinders, fined with its own dust, and French polished in the ordinary way. Spools for coils of considerable radial dimension may be most conveniently made of slate instead of wood or brass, both because it keeps its shape, and because it insulates sufficiently well to stop eddy currents--at all events, sufficiently for ordinary practice. An appreciable advantage is that slate may be purchased at a reasonable rate in large slabs of any desired thickness. It is generally cut in the laboratory by means of an old cross-cut saw, but it does not do much damage to a hard hack saw such as is used for iron or brass. Marble. According to Holtzapffell, marble may be easily turned by means of simple pointed tools of good steel tempered to a straw colour. The cutting point is ground on both edges like a wood-turning tool, and held up to the work "at an angle of twenty or thirty degrees" (?with the horizontal). The marble is cut wet to save the tool. As soon as the point gets, by grinding, to be about one-eighth of an inch broad it must either be drawn down or reground; a flat tool will not turn marble at all. A convenient saw for marble is easily made on the principle of the frame saw. A bit of hoop iron forms a convenient blade, and is sharpened by being hammered into notches along one edge, using the sharp end of a hammer head. The saw is liberally supplied with sand and water--or emery and water, where economy of time is an object. The sawing of marble is thus really a grinding process, but it goes on rapidly. Marble is ground very easily with sand and water; it is fined with emery and polished with putty powder, which, I understand, is best used with water on cloth or felt. As grinding processes have already been fully described, there is no need to go into them here. I have no personal knowledge of polishing marble. § 116. Conductors. The properties of conductors, more particularly of metals, have been so frequently examined, that the literature of the subject is appallingly heavy. In what follows I have endeavoured to keep clear of what might properly appear in a treatise on electricity on the one hand, and in a wiring table on the other. The most important work on the subject of the experimental resistance properties of metals has been done by Matthieson, Phil. Trans. 1860 and 1862, and British Association Reports (1864); Callender, Phil. Trans. vol. clxxiii; Callender and Griffiths, Phil. Trans. vol. clxxxii; The Committee of the British Association on Electrical Standards from 1862 to Present Time; Dewar and Fleming, Phil. Mag. vol. xxxvi. (1893); Klemencic, Wiener Sitzungsberichte (Denkschrift), 1888, vol. xcvii. p. 838; Feussner and St. Lindeck, Zeitsch. fuer Inst. 'Kunde, ix. 1889, p. 233, and B. A. Reports, 1892, p. 139. Of these, Matthieson, and Dewar and Fleming treat of resistance generally, the latter particularly at low temperatures. [Footnote: The following is a list of Dr. Matthieson's chief papers on the subject of the electrical resistance of metals and alloys: Phil. Mag. xvi. 1858, pp. 219-223; Phil. Trans. 1858, pp. 383-388 Phil. Trans. 1860, pp. 161-176; Phil. Trans. 1862, pp. 1-27 Phil. Mag. xxi. (1861), pp. 107-115; Phil. Mag. xxiii. (1862), pp. 171-179; Electrician, iv. 1863, pp. 285-296; British Association Reports, 1863, p. 351.] Matthieson, and Matthieson and Hockin, Klemencic, Feussner, and St. Lindeck deal with the choice of metals for resistance standards. Callender's, and Callender and Griffiths' work is devoted to the study of platinum for thermometric purposes. The bibliography referring to special points will be given later. The simplest way of exhibiting the relative resistances of metals is by means of a diagram published by Dewar and Fleming (loc. cit.), which is reproduced on a suitable scale on the opposite page. For very accurate work, in which corrections for the volumes occupied by the metals at different temperatures are of importance, the reader is referred to the discussion in the original paper, which will be found most pleasant reading. From this diagram both the specific resistance and the temperature coefficient may be deduced with sufficient accuracy for workshop purposes. In interpreting the diagram the following notes will be of assistance. The diagram is drawn to a scale of so-called "platinum temperatures"--that is to say, let R0, R100, Rt be the resistances of pure platinum at 0°, 100°, and t° C. respectively, then the platinum temperature pt is defined as pt = 100 X (Rt-R0)/(R100-R0) This amounts to making the temperature scale such that the temperature at any point is proportional to the resistance of platinum at that point. Consequently on a resistance temperature diagram the straight line showing the relation between platinum resistance and platinum temperature will "run out" at the platinum absolute zero, which coincides more or less with the thermodynamic absolute zero, and also with the "perfect gas" absolute zero. Platinum temperatures may be taken for workshop purposes over ordinary ranges as almost coinciding with air thermometer temperatures. The metals used by Professors Dewar and Fleming were, with some exceptions, not absolutely pure, but in general represent the best that can be got by the most refined process of practical metallurgy. We may note further that the specific resistance is only correct for a temperature of about 15° C, since no correction for the expansion or contraction of material has been applied. The following notes on alloys suitable for resistance coils will probably be found sufficient. § 117. Platinoid. This substance, discovered by Martino and described by Bottomley (Phil. Proc. Roy. Soc. 1885), is an alloy of nickel, zinc, copper, and 1 per cent to 2 per cent of tungsten, but I have not been able to obtain an analysis of its exact composition. It appears to be difficult to get the tungsten to alloy, and it has to be added to part of the copper as phosphide of tungsten, in considerably greater quantity than is finally required. The nickel is added to part of the copper and the phosphide of tungsten, then the zinc, and then the rest of the copper. The alloy requires to be remelted several times, and a good deal of tungsten is lost by oxidation. The alloy is of a fine white colour, and is very little affected by air--in fact, it is to some extent untarnishable. The specific resistance will be seen to be about one and a half times greater than that of German silver, and the temperature coefficient is about 0.021 per cent per degree C. (i.e. about nineteen times less than copper, and half that of German silver). To all intents and purposes it may be regarded as German silver with 1 per cent to 2 per cent of tungsten. It does not appear to have been particularly examined for secular changes of resistance. 118. German Silver. This material has been exhaustively examined of late years by Klemencic and by Feussner and St. Lindeck. Everybody agrees that German silver, as ordinarily used for resistances, and composed of copper four parts, zinc two parts, nickel one part, is very ill-fitted for the purpose of making resistance standards. This is due (1) to its experiencing a considerable increase in resistance on winding. Feussner and St. Lindeck found an increase of 1 per cent when German silver was wound on a core of ten wire diameters. (2) To the fact that the change goes on, though with gradually decreasing rate, for months or years; (3) to the fact that the resistance is permanently changed (increased) by heating to 40° C. or over. By "artificially ageing" coils of German silver by heating to 150° C, say for five or six hours, its permanency is greatly improved, and it becomes fit for ordinary resistance coils where changes of, say, 1/5000 do not matter. It is a remarkable property of all nickel alloys containing zinc that their specific resistance is permanently increased by heating, whereas alloys which do not contain zinc suffer a change in the opposite direction. The manufacturers of German silver appear to take very little care as to the uniformity of the product put on the market; some so-called German silver is distinctly yellow, while other samples are bright and white. It is noted by Price (Measurements of Electrical Resistance, p. 24) that German silver wire is apt to exhibit great differences of resistance within quite short lengths. This has been my own experience as well, and is a great drawback to the use of German silver in the laboratory, for it makes it useless to measure off definite lengths of wire with a view to obtaining an approximate resistance. In England German silver coils are generally soaked in melted hard paraffin. In Germany, at all events at the Charlottenburg Institute, according to St. Lindeck--coils are shellac-varnished and baked. In any case it appears to be essential to thoroughly protect the metal against atmospheric influence. § 119. Platinum Silver. In the opinion of Matthieson and of Klemencic the 10 per cent silver, 90 per cent platinum alloy is the one most suitable for resistance standards. At all events, it has stood the test of time, for, with the following exceptions, all the British Association coils constructed of it from 1867 to the present day have continued to agree well together. The exceptions were three one-ohm coils, which permanently increased between 1888 and 1890, probably through some straining when immersed in ice. One coil changed by 0.0006 in 1 between the years 1867 and 1891. According to Klemencic, absolute permanency is not to be expected even from this alloy. Its recommendation as a standard depends on its chemical inertness, its small temperature coefficient (0.00027 per degree), and its small thermo-voltage against copper, as the following table (taken from Klemencic) will show:- Thermo-voltages in Micro-volts per degree against Copper over the Range 0° to 17° C. Platinum iridium 7.14 micro-volts per degree C. Platinum silver 6.62 micro-volts per degree C. Nickelin 28.5 micro-volts per degree C. German silver 10.43 micro-volts per degree C. Manganin (St. Lindeck) 1.5 micro-volts per degree C. Mechanically, the platinum silver is weak, and is greatly affected as to its resistance by mechanical strains--in fact, Klemencic considers it the worst substance he examined from this point of view--a conclusion rather borne out by Mr. Glazebrook's experience with the British Association standards already referred to (B. A. Reports, 1891 and 1892). Taking everything into account, it will probably be well to construct standards either with oil insulation only, or to bake the coils in shellac before testing, instead of soaking in paraffin. Fig. 89 illustrates a form of an oil immersed standard which is in use in my laboratory, and through which a considerable current may be passed. The oil is stirred by means of a screw propeller. Fig. 89. Fig. 89 represents a standard resistance for making Clerk cell comparisons by the silver voltameter method. The framework on which the coils are wound consists of a base and top of slate. The pillars are of flint glass tube surrounding brass bolts, and cemented to the latter by raw shellac. Grooves are cut in the glass sleeves to hold the wires well apart. These grooves were cut by means of a file working with kerosene lubrication. A screw stirrer is provided, and the whole apparatus is immersed in kerosene in the glass box of a storage cell. The apparatus is aged to begin with by heating to a temperature a good deal higher than any temperature it is expected to reach in actual work. After this the rigidity of the frame is intended to prevent any further straining of the wire. The apparatus as figured is not intended to be cooled to 0° C, so that it is put in as large a box as possible to gain the advantage of having a large volume of liquid. The top and bottom slates measure seven inches by seven inches, and the distance between them is seven inches. The inner coil is wound on first, and the loop which constitutes the end of the winding is brought up to a suitable position for adjustment. The insulation of the heavy copper connectors is by means of ebonite. § 120. Platinum Iridium. Platinum 90 per cent, iridium 10 per cent. This material was prepared in some quantity at the cost of the French Government, and distributed for test about 1886. Klemencic got some of it as representing Austria, and found it behaved very like the platinum silver alloy just discussed. The temperature coefficient is, however, higher than for platinum silver (0.00126 as against 0.00027). The mechanical properties of the alloy are, however, much better than those of the silver alloy; and in view of the experience with B. A. standards above quoted, it remains an open question whether, on the whole, it would not be the better material for standards, in spite of its higher price. Improvements in absolute measurements of resistance, however, may render primary standards superfluous. § 121. Manganin. Discovered by Weston--at all events as to its application to resistance coils. A glance at the diagram will exhibit its unique properties, on account of which it has been adopted by the Physikalisch Technischen Reichsanstalt for resistance standards. The composition of the alloy is copper 84 per cent, manganese 12 per cent, nickel 4 per cent, and it is described as of a steel-gray colour. Unfortunately it is apt to oxidise in the air, or rather the manganese it contains does so, so that it wants a very perfect protection against the atmosphere. Like German silver, manganin changes in resistance on winding, and coils made of it require to be artificially aged by heating to 150° for five hours before final adjustment. The annealing cannot be carried out in air, owing to the tendency to oxidation. The method adopted by St. Lindeck (at all events up to 1892) is to treat the coil with thick alcoholic shellac varnish till the insulation is thoroughly saturated, and then to bake the coil as described. The baking not only anneals the wire, but reduces the shellac to a hard and highly insulating mass. Whether stresses of sufficient magnitude to produce serious mechanical effects can be set up by unequal expansion of wire and shellac during heating and cooling is not yet known, but so far as tested (and it must be presumed that the Reichsanstalt tests are thorough) no difficulty seems to have been met with. In course of time, however, probably the best shellac coating will crack, and then adieu to the permanency of the coil! This might, of course, be obviated by keeping the coil in kerosene, which has no action on shellac, but which decomposes somewhat itself. The method of treatment above described suffices to render coils of manganin constant for at least a year (in 1892 the tests had only been made for this time) within a few thousands per cent. Manganin can be obtained in sheets, and from this material standards of 10-2, 10-3, and 10-4 ohms are made by soldering strips between stout copper bars, and these are adjusted by gradually increasing their resistance by boring small holes through them. The solder employed is said to be "silver." Mr. Griffiths (Phil. Trans. vol. clxxxiv. [1893], A, p. 390) has had some experience with manganin carrying comparatively heavy currents, under which circumstances its resistance when immersed in water was found to rise in spite of the varnish which coated it. Other experiments in which the manganin wire was immersed in paraffin oil did not exhibit this effect, though stronger currents were passed. On the whole, manganin appears to be the best material for coil boxes and "secondary" resistance standards. Whether it is fit to rank with the platinum alloys as regards permanency must be treated as an open question. § 122. Other Alloys. The following tables, taken from the work of Feussner and St. Lindeck, Zeitschrift fuer Instrumenten Kunde, 1889, vol. ix. p. 233, together with the following notes, will suffice. § 123. Nickelin. This is only German silver with a little less zinc, a little more nickel, and traces of cobalt and manganese. It behaves like German silver, but is an improvement on the latter in that all the faults of German silver appear upon a reduced scale in nickelin. § 124. Patent Nickel. Practically a copper nickel alloy, used to some extent by Siemens and Halske. It stands pretty well in the same relation to nickelin as the latter does to German silver. After annealing as for manganin it can be made into serviceable standards which do not change more than a few thousandths per cent. I have not come across a statement of its thermo-voltage against copper. § 125. Constantin. Another nickel copper alloy containing 50 per cent of each constituent. It appears to be a serviceable substance, having a temperature coefficient of 0.003 per cent per degree only, but an exceedingly high thermo-voltage, viz. 40 micro-volts per degree against copper. 1 2 3 4 5 6 7 8 German Nickelin made Rheo- Patent Nickel Manga- Nickel Silver by Obermaier tane nese Manga- Dia- Dia- Dia- Dia- Copper nese meter meter meter meter Copper 1.0mm 0.1mm 0.6mm 1.0mm Copper 60.16 61.63 54.57 53.28 74.41 74.71 70 73 Zinc 25.37 19.67 20.44 16.89 0.23 0.52 ... ... Tin ... ... ... ... trace ... ... Nickel 14.03 18.46 24.48 25.31 25.10 24.14 ... 3 Iron 0.30 0.24 0.64 4.46 0.42 0.70 ... ... Cobalt trace 0.19 ... ... trace trace ... ... Mang- trace 0.18 0.27 0.37 0.13 0.17 30 24 anese. 99.86 100.37 100.40 100.31 100.24 100.24 ... ... Specific resistance 30.0 33.2 44.8 52.5 34.2 32.8 100.6 47.7 Temperature coefficient 0.00036 0.00030 0.00033 0.00041 0.00019 0.00021 0.00004 0.00003 The specific resistance is in microhms, i.e. 10-6 ohms per cubic centimetre, and the temperature coefficient in degrees centigrade. 126. Nickel Manganese Copper. I can find no other reference with regard to this alloy mentioned by Lindeck. Nicholls, however (Silliman's Journal [3], 39, 171, 1890), gives some particulars of alloys of copper and ferromanganese. The following table is taken from Wiedemann's Beiblatter (abstract of Nicholl's paper, 1890, p. 811). All these alloys appear to require annealing at a red heat before their resistances are anything like constant. Let x be percentage of copper, then 100--x is percentage of "ferromanganese." Values of x. 100 99.26 91 .88 86.98 80.4 70.65 Specific resistance with respect to copper (? pure) 1 1.19 11.28 20.4 27.5 45.1 Temperature coefficient per degree x 10^6(hard) 3202 2167 138 16 22 -24 Ditto (soft) ... ... 184 80 66 21 If nickel is added, alloys of much the same character are obtained, some with negative temperature coefficients--for instance, one containing 52.51 per cent copper, 31.27 per cent ferromanganese, and 16.22 nickel. A detailed account of several alloys will be found in a paper by Griffiths (Phil. Trans. 1894, p. 390), but as the constants were determined to a higher order of accuracy than the composition of the material--or, at all events, to a higher degree of accuracy than that to which the materials can be reproduced--there is no advantage in quoting them here. CHAPTER IV ELECTROPLATING AND ALLIED ARTS § 127. Electroplating. This is an art which is usually deemed worthy of a treatise to itself, but for ordinary laboratory purposes it is a very simple matter--so simple, indeed, that the multiplicity of receipts as given in treatises are rather a source of embarrassment than otherwise. The fundamental principles of the art are:- (1) Dirty work cannot be electroplated. (2) Electroplated surfaces may be rougher, but will not be smoother than the original unplated surface. (3) The art of electroplating being in advance of the science, it is necessary to be careful as to carrying out instructions in detail. This particularly applies to the conditions which determine whether a metallic deposit shall come down in a reguline or in a crystalline manner. § 128. The Dipping Bath. An acid dipping bath is one of the most useful adjuncts to the laboratory, not only for cleansing metals for electroplating, but for cleaning up apparatus made out of bits of brass tube and sheet, and particularly for quickly cleaning binding screws, etc, where it is necessary to ensure good electrical contact. The cheapest and most satisfactory way in the end is to make up two or three rather large baths to begin with. The glass boxes of storage batteries do very nicely for the purpose, and being generally ground pretty flat at the top, they may be covered by sheets of patent plate glass, and thus preserved from the action of the air. First Bath. A 30 or 40 per cent solution of commercial caustic soda. Objects may be cleansed from grease in this bath by heating them as hot as is consistent with individual circumstances, and plunging them into it. It is a considerable advantage to begin by removing grease from articles subsequently to be dipped in an acid bath, both because it saves time and acid, and because more uniform results are obtainable when this is done than when it is omitted. It is a great advantage to have the caustic soda solution hot. This is always done in factories where nickel-plating is carried on, but it is inconvenient in the laboratory. The articles after dipping in the alkali are swilled with water, and may even be scrubbed with a brush, so as to remove greasy matters that have been softened but not entirely removed. Acid Bath. A convenient bath for laboratory purposes is made by mixing two volumes of strong commercial nitric acid with one of strong sulphuric acid in a cell measuring, say, 12 X 10 X 15 inches. Copper or brass articles are dipped in this bath for a few seconds, then rinsed with water, then dipped again for a second or two, or until they appear equally white all over, and then withdrawn as rapidly as possible and plunged into a large quantity of clean water. Care must be taken to transfer the articles from the bath to the water as quickly as possible, for if time be allowed for gas to be evolved, the surfaces become mat instead of bright. In order to save acid it is advisable to make up a third bath, using those odds and ends of acids which gradually accumulate in the laboratory. Sulphuric acid from the balance cases, for instance, mixed with its own volume of commercial nitric acid, does very well. The objects to be dipped receive a preliminary cleansing by a dip in this bath, the strong bath being reserved for the final dip. Sheet brass and drawn tube, as it comes from the makers, possesses a really fine surface, though this is generally obscured by grease and oxide. Work executed in these materials, cleaned in alkali, and dipped in really strong acid, will be found to present a much better appearance than work which has been filed, unless the latter be afterwards elaborately polished. On no account must paraffin be allowed to get into any of the baths. When the final bath gets weak it must be relegated to a subordinate position and a new bath set up. A weak acid bath leaves an ugly mottled surface on brass work. § 129. A metallic surface which it is intended to electroplate must, as has been mentioned, be scrupulously clean. If the metal is not too valuable or delicate, cleaning by dipping is easy and effectual. The following notes will be found to apply to special cases which often occur. (1) Silver Surfaces intended to be gilt. These are first washed clean with soap and hot water, and polished with whitening. They are then dipped for a moment in a boiling solution of potassium cyanide. A 20 per cent solution of common commercial cyanide does well, but the exact strength is quite immaterial. The cyanide is washed away in a large volume of soft water, and the articles are kept under water till they are scratch-brushed. Mat surfaces are readily produced on standard silver by dipping in hot strong sulphuric acid. The appearance of new silver coins, which is familiar to everybody, is obtained by this process. (2) Finely turned and finished Brass Work. If it is intended to nickel-plate such work, and if it is desirable to obtain brightly polished nickel surfaces, the work must be perfectly polished to begin with. Full details as to polishing may be found in workshop books or treatises on watch-making. It will suffice here to say that the brass work is first smoothed by the application of successive grades of emery and oil, or by very fine "dead" smooth files covered with chalk. Polishing is carried out by means of rotten stone and oil applied on leather. In polishing turned work care must be taken to move the file, emery, or rotten stone to and fro over the work with great regularity, or the surface will end by looking scratchy and irregular. The first process of cleaning is, of course, to remove grease, and this is accomplished best by dipping in a bath of strong hot caustic soda solution, and less perfectly by heating the work and dipping it in the cold caustic soda bath. During this process a certain amount of chemical action often occurs leading to the brass surface exhibiting some discoloration. The best way of remedying this is to dip the brass into a hot bath of cyanide of potassium solution. If it is inconvenient to employ hot baths or to heat the brass work, good results may be obtained by rubbing the articles over with a large rough cork plentifully lubricated with a strong solution of an alkali. If the surfaces are very soiled or dirty, a paste of alkali and fine slaked lime may be applied on a cork rubber, and this in my experience has always been most effective and satisfactory in every way, except that it is difficult to get into crevices. If the alkali stains the work, a little cyanide of potassium may be rubbed over the surface in a similar manner. Brass work treated by either of these methods is to be washed in clean water till the alkali is entirely removed, and may then be nickel-plated without any preliminary scratch-brushing. The treatment in hot baths of alkali and cyanide is the method generally employed in American factories as a preliminary to the nickelling of small brass work for sewing machines, etc. (3) Copper either for use as the kathode in electrolysis calibration experiments or otherwise is most conveniently prepared by dipping in the acid bath, rinsing quickly in cold water, scratch-brushing under cold water, and transferring at once to the plating bath. In the case where the copper plates require to be weighed they are dipped into very hot distilled water after scratch-brushing, and then dried at once by means of a clean glass cloth. (4) Aluminium (which, however, does not readily lend itself to plating operations [Footnote: This difficulty has now been overcome. See note, section 138.] ) is best treated by alkali rubbed on with a cork, or by a hot alkaline carbonate where rubbing is inexpedient. The clean aluminium is scratch-brushed under water, and at once transferred to the plating bath. (5) Iron for Nickel-plating. According to Dr. Gore (Electra-metallurgy, p. 319) the best bath for cleaning iron is made as follows: "One gallon of water and one pound of sulphuric acid are mixed with one or two ounces of zinc (which of course dissolves); to this is added half a pound of nitric acid." The writer has been accustomed to clean iron by mechanical means, to deprive it of grease by caustic alkali, and to finish it off by, means of a hard scratch brush. This process has always worked satisfactorily. (6) Articles soldered with soft solder containing lead and tin do not readily lend themselves to electrolytic processes, the solder generally becoming black and refusing to be coated with the electro-deposit. Moreover, if soldered articles are boiled for any length of time in caustic alkali during the preliminary cleansing, enough tin will dissolve to form a solution of stannate of potash or soda--strong enough to deposit tin on brass or copper. A method of coppering soldered articles will be described later on. § 130. Scratch-brushing. This process is generally indispensable, and to its omission is to be traced most laboratory failures in electroplating. Scratch-brushes may be bought at those interesting shops where "watchmakers' supplies" are sold. It will be well, therefore, to purchase a selection of scratch brushes, for they are made to suit particular kinds of work. They are all made of brass wire, and vary both in hardness and in the fineness of the wire. The simplest kind of scratch brush consists merely of a bundle of wires bound up tightly by another wire, and somewhat "frizzed" out at the ends (Fig. 90). A more useful kind is made just like a rotating brush, and has to be mounted on a lathe (Fig. 91). Fig. 90. Fig. 91. The scratch brush is generally, if not always, applied wet; the lubricant generally recommended is stale beer, but this may be replaced by water containing a small quantity of glue, or any other form of gelatine in solution--a mere trace (say .1 per cent) is quite sufficient. Very fair results may be got by using either pure or soapy water. The rotating brushes require to be mounted on a lathe, and may be run at the same speed as would be employed for turning wooden objects of the same dimensions. Since the brush has to be kept wet by allowing water or its equivalent to drip upon it, it is usual to make a tin trough over which the brush can revolve, and to further protect this by a tin hood to keep the liquid from being thrown all over the room. In many works the brush is arranged to lie partly in the liquid, and this does very well if the hood is effective. There is a superstition that electro-deposits stick better to scratch-brushed surfaces than to surfaces which have not been so treated, and consequently it is usual to scratch-brush surfaces before electro-deposit. However this may be, there is no doubt that adherence and solidity are promoted by frequent scratch-brushing during the process of depositing metal, especially when the latter tends to come down in a spongy manner. Gilt surfaces--if the gilding is at all heavy--are generally dull yellow, or even brown, when they come from the bath, and require the scratch brush to cause the gold to brighten, an office which it performs in a quite striking manner. The same remark applies to silvered surfaces, which generally leave the bath a dead white--at all events if the deposit is thick, and if ordinary solutions are employed. In either case the touch of the scratch brush is magical. § 131. Burnishing. Burnishers of steel, agate, or bloodstone can be bought at the shops where scratch brushes are sold, and are used to produce the same brightening effect as can be got by scratch-brushing. The same solutions are employed, but rather stronger, and the burnisher is swept over the surface so as to compress the deposited metal. Burnishing is rather an art, but when well done gives a harder and more brilliant (because smoother) surface than the scratch brush. On the whole, steel burnishers are the most convenient if in constant use. If the burnishing tools have to lie about, steel is apt to rust, unless carefully protected by being plunged in quicklime or thickly smeared with vaseline, and the least speck of rust is fatal to a burnisher. In any case the steel requires to be occasionally repolished by rouge and water on a bit of cloth or felt. The process of burnishing is necessarily somewhat slow and tedious, and as a rule is not worth troubling about except in cases where great permanence is required. The burnisher is moved over the work somewhat like a pencil with considerable pressure, and care is taken to make the strokes as uniform in direction as possible; otherwise the surface looks non-uniform, and has to be further polished by tripoli, whitening, etc, before it is presentable. § 132. Silver-plating. The most convenient solution for general purposes is an 8 to 10 per cent solution of the double cyanide of silver and potassium together with 1 or 2 per cent of "free" potassium cyanide. Great latitude is permissible in the strength of solution and density of current. As commercial cyanide of potassium generally contains an unknown percentage of other salts, which, however, do not interfere with its value for the purpose of silver-plating, the simplest procedure is as follows. For every 100 c.c. of plating solution about 7 grms. of dry crystallised silver nitrate are required. The equivalent amount of potassium cyanide (if dry and pure) is 5.2 grms, but commercial cyanide may contain from 50 per cent upwards to 96 per cent in the best fused cyanide made from ferrocyanide only. An approximate idea of the cyanide content can be obtained from the dealers when the salt is purchased, and this is all that is required. A quantity slightly in excess of the computed amount of cyanide is dissolved in distilled water, and this is cautiously added to the solution of the silver nitrate till precipitation is just complete. The supernatant liquors are then drained away, and the precipitate dissolved by adding a sufficiency of the remaining cyanide; this process is assisted by warming and stirring. An allowance of about one-tenth of the whole cyanide employed may be added to form "free" cyanide, and the solution made up to the strength named. It is advisable to begin with the cyanide in a moderately strong solution, for the sake of ease in dissolving the precipitate. This solution will deposit silver upon articles of copper or brass immersed in it even without the battery, but the coat will be thin. The solution is used cold, with a current density of about 10 to 20 ampères per square foot. The articles to be silvered are scratch-brushed, washed, and electroplated, till they begin to look undesirably rough. They are then taken out of the bath, rebrushed, and the process continued till a sufficiency of silver is deposited. Four grammes weight of silver (nearly) is deposited per ampère hour. It is best to use a fine silver anode, so that the solution, does not get contaminated by copper. In most factories it is usual to "quicken" the objects to be silvered before placing them in the electrolysis vats, because the deposit is said to adhere better in consequence of this treatment. I have never found it any improvement for laboratory purposes, but it is easy to do. A dilute (say 2 per cent) solution of cyanide of mercury is required containing a little free cyanide. The objects to be "quickened" are scratch-brushed and dipped into the cyanide of mercury solution till they are uniformly white; it is generally agreed that the less the mercury deposited the better, so long as a perfect coating is obtained. The objects are rinsed after quickening, and put in the depositing bath at once. The mat surface of silver obtained by electrolysis of the cyanide is very beautiful--one of the most beautiful things in nature--shining with incomparable crystalline whiteness. So delicate is it, however, for so great is the surface it exposes, that it is generally rapidly deteriorated by exposure to the air. It may be protected to some extent by lacquering with pale lacquer, but it loses some of its brilliancy and purity in the process. The deposit is generally scratch-brushed or burnished down to a regular reflecting surface. § 133. Cold Silvering. A thin but brilliant coat of silver may be readily applied to small articles of brass or copper in the following way. A saturated solution of sodium sulphite (neutral) is prepared, and into this a 10 per cent solution of nitrate of silver is poured so long as the precipitate formed is redissolved. A good deal of silver may be got into solution in this way. Articles to be silvered need only to be cleaned, brushed, and dipped in this solution till a coat of the required thickness is obtained. I must admit, however, that the coating thus laid on does not appear to be so permanent as one deposited by simple immersion from the cyanide solution, even though it is thicker. The cyanide plating solution will itself give a good coat of silver if it is used boiling, and if a little potassium cyanide be added. For purposes of instrument construction, however, a thin coat of silver is seldom to be recommended, on account of its liability to tarnish and its rapid destruction when any attempt is made to repolish it. For these reasons, nickel or gold plating is much to be preferred. § 134. Gilding. This art deserves to be much more widely practised than is usual in laboratories. Regarded as a means of preserving brass, copper, or steel, it is not appreciably more "time robbing" than lacquering, and gives infinitely better results. Moreover, it is not much more expensive. Strange as it may seem, the costliness of gilding seldom lies in the value of the gold deposited; the chief cost is in the chemicals employed to clean the work, and in interest on the not inconsiderable outlay on the solution and anode. The easiest metal to gild is silver, and it is not unusual to give base metals a thin coating of silver or copper, or both, one after the other, before gilding, in order to secure uniformity. To illustrate the virtue of a thin layer of gold, I will mention the following experiment. About three years ago I learned for the first time that to "clean" the silver used in a small household required at least an hour's labour per diem. I further ascertained that most of this time is spent on the polishing part of the process. As this seemed a waste of labour, I decided to try the effect of gilding. In order to give the proposal a fair trial I gilt the following articles: half a dozen table spoons and forks, a dozen dessert forks and spoons, and a dozen tea spoons. These were all common electroplated ware. They were weighed before and after gilding, and it was with difficulty that the increase of weight was detected, even though a fine bullion balance was employed. On calculating back to money, it appeared that the value of the gold deposited was about threepence. Assuming that an equal weight of silver had been accidentally dissolved by the free cyanide during the plating--which is unlikely--the total amount of gold deposited would be worth, say, sixpence. After three years' continuous use the gilding is still perfect, except at the points on which the spoons and forks rest, where it is certainly rather shabby. Meanwhile the "gold" plate only requires to be washed with hot water and soap to keep it in perfect order, a much more cleanly and expeditious process than that of silver cleaning. § 135. Preparing Surfaces for Gilding. Ordinary brass work--rough or smooth--may for purposes of preservation be dipped, scratch-brushed, and gilt at once. Seven years ago the writer gilt the inside of the head of a copper water still, and simply scratch-brushed it; it is to-day in as good order as when it was first done. If it is intended to gild work from the first, with the view of making an exceptionally fine job of it, "gilding metal," i.e. brass containing one to one and a quarter ounces of zinc to the pound of copper may be specified. From its costliness, however, this is only desirable for small work. Iron and steel are generally given a preliminary coating of copper, but this may be dispensed with though with no advantage--by using a particular process of gilding. Base metals, zinc, pewter, lead, etc, are first coppered in a cyanide of copper solution, as will be described under the head of Copper-plating. If it is intended to gild soldered articles, the preliminary coating of copper is essential. The most convenient vessel for holding a gilding solution is undoubtedly one formed of enamelled iron. Particularly useful are the buckets and "billies" (i.e. cylindrical cans) made of this material. These vessels may be heated without any fear of a smash, and do not appear to be appreciably affected by gilding solutions--at all events during several days or weeks. The avoidance of all risk of breakage when twenty or thirty pounds' worth of solution is in question is a matter of importance. Under no circumstances is it desirable to use anything but the purest gold and best fused cyanide (called "gold" cyanide) in the preparation of the solutions. The appearance of a pure gold deposit is far richer than of one containing silver, and its resistance to the atmosphere is perfect; moreover, in chemico-physical processes one has the satisfaction of knowing what one is dealing with. § 136. Gilding Solutions. The strength of solution necessary for gilding brass, copper, and silver is not very material. About one to two pounds of "gold" potassium cyanide (? 96 per cent KCN) per gallon does very well. The gold is best introduced by electrolysing from a large to a small gold electrode. One purchases a plate of pure gold either from the mint or from reliable metallurgists (say Messrs. Johnson and Matthey of London), and from this electrodes are cut. The relative areas of the electrodes do not really much matter. I have used an anode of four times the area of the cathode. The solution is preferably heated to a temperature of about 50° C, and a strong current is sent through it, say twenty amperes to the square foot of anode. The electrodes must be suspended below the surface of the solution by means of platinum wires. If the gold plates are only partly immersed, they dissolve much more rapidly where they cut the surface, possibly on account of the effect of convection currents, though so far as the writer is aware no proper explanation has yet been given. After a time gold begins to be deposited on the cathode in a powdery form, for which reason it is a good plan to begin by wrapping the latter in filter paper. The process has gone on for a sufficient time when a clean bit of platinum foil immersed in the place of the cathode becomes properly gilt at a current density of about ten amperes per square foot. The powdery gold deposited on the cathode while preparing the solution can be scraped off and melted for further use, or the whole cathode may now be used as an anode. The platinum foil testing cathode may also be "stripped" by making it an anode, and is for this reason preferable to German silver or copper, which would contaminate the solution while the "stripping" process was in progress. For general purposes a current density of say ten to fifteen amperes per square foot may be used, but this may be considerably varied, so long as the upper limit is not greatly overpassed. During gold-plating there is a considerable advantage in keeping the electrodes moving or the solution stirred. After immersing the cleaned and scratch-brushed articles, depositing may go on for about three minutes, after which they are removed from the bath and examined, in order to detect any want of uniformity in the deposit. The articles should be entirely immersed; if this is not done, irregularity is apt to appear at the surface. Platinum wires employed as suspenders, and coated along with the articles to be gilt, may also be cleaned without loss by making them anodes. If, on examination, all is found to be going on well, reimmerse the cathodes, and continue plating till they appear of a dull yellowish brown (this will occur in about four minutes), then remove them, rinse and scratch-brush them, and replace them in the bath. When a second coat appears to be getting rather brown than yellowish brown, i.e. of the colour of wet wash-leather, the removal, followed by scratch-brushing, may be repeated, and for nearly all laboratory purposes, the articles are now fully gilt. The coating of gold deposited from a hot cyanide solution is spongy in the extreme, and if the maximum wear-resisting effect is to be obtained, it is advisable to burnish the gold rather than to rely upon the scratch brush alone. If the area of the cathode exceeds that of the anode the solution is said to grow weaker, and vice versa. This may be remedied in the former case by an obvious readjustment; the latter introduces no difficulty so far as I know except when plating iron or steel. The student need not be troubled at the poor appearance of the deposit before it is scratch-brushed. Heavy gold deposits are almost always dull, not to say dirty, in appearance till the burnisher or scratch brush is applied. On the other hand, the deposit ought not to get anything like black in colour. The following indications of defects may be noted--they are taken from Gore. I have never been really troubled with them. The deposit is blackish. This is caused by too strong a current in too weak a bath. This may be remedied to some extent by stirring or keeping the cathode in motion. The obvious remedy is to add a little cyanide of gold. The gold anode gets incrusted. This is a sign that the bath is deficient in potassium cyanide. The gold anode gets black and gives off gas. The solution is deficient in cyanide, and too large a current is being passed. If a bright surface is desired direct from the bath, some caustic potash (say 2 per cent) may, according to Gore, be added, or the articles may be plated only slightly by using a weak current and taking them out directly they show signs of getting dull. By a weak current I mean one of about five amperes per square foot. The deposit is said to be denser if the solution be heated as directed; but the bath will gild, though not quite so freely when cold. To gild iron or steel directly, dilute the bath as above recommended some five or six times, add about 1 per cent of potassium cyanide, and gild with a very weak current (say two or three amperes per square foot) in the cold. Frequent scratch-brushing will be found requisite to secure proper adherence. It is generally recommended to gild brass or German silver in solutions which are rather weak, but in the small practice which occurs in the laboratory a solution prepared as suggested does perfectly for everything except iron or steel. The scratch-brushing should be done over a large photographic developing dish to avoid loss of gold. It is a good plan to rinse the articles after leaving the bath in a limited quantity of distilled water, which is afterwards placed in a "residue" bottle, and then to scratch-brush them by hand over the dish to catch fine gold. When any loose dust is removed the articles may be scratched in the lathe without appreciable further loss. Silver-gilt articles tend to get discoloured by use, but this discoloration can be removed by soap and water. After long use a gold cyanide bath tends to alter greatly in composition, In general, the bath tends to grow weaker, from the fact that there is a strong temptation to gild as many articles at once as possible. It is therefore a good plan to keep a rough profit and loss account of the gold in order to find the quantity in solution. Fifty dwts. per gallon (or 78 grms. per 4.5 litres) is recommended. A gallon of solution of this strength is worth about eleven pounds sterling in gold and cyanide, and a serviceable anode will be worth about 10 pounds. (Fine gold is worth nominally four pounds four shillings and eleven pence ha'penny per oz.) Gold may be easily obtained containing less impurity than one part in ten thousand. § 137. Plating with Copper. Copper may be deposited from almost any of its salts in reguline form, the sulphate and nitrate being most usually employed. In the laboratory a nearly saturated solution of sulphate of copper with 1 or 2 per cent of sulphuric acid will answer most purposes. A current density of, at most, fifteen amperes per square foot may be used, either for obtaining solid deposits for constructional purposes or for calibrating current measuring instruments by electrolysis. A copper anode is of course employed. When coppering with a view to obtaining thick deposits it is a good plan to place the electrodes several inches apart, and, if possible, to keep the liquid stirred, as there is a considerable tendency on the part of copper deposits to grow out into mossy masses wherever the current density exceeds the limit mentioned. As the masses grow towards the anode the defect naturally tends to increase of itself, hence the necessity for care. The phenomenon is particularly marked at the edges and corners of the cathode. If the deposit becomes markedly irregular, the best plan is to stop the process and file the face of the deposit down to approximate smoothness. In coppering it is of the utmost importance that the cathode be clean and free from grease; it must never be touched (by the finger, for instance) from the time it is scratch-brushed till it is immersed in the plating bath. Any grease or oxidation tends to prevent the copper deposit adhering properly. A copper deposit oxidises very easily when exposed to the air. Consequently if the surface be required free from oxide, as, for instance, when it is to be silvered or gilt, it must be quickly washed when withdrawn from the coppering bath, scratch-brushed, and transferred immediately to the silvering or gilding bath. If the surface is to be dried, as in electrolysis calibrations, it must be rinsed quickly with boiling water and pressed between sheets of filter paper. Another method which has been recommended is to rinse the copper in--water slightly acidulated with sulphuric acid (which prevents oxidation), then in distilled water, and to dry by blotting paper and in front of a fire, taking care not to make the plate too hot. The wash water is sufficiently acidulated by the addition of two or three drops of acid per litre. So far as I know, the method of washing in acidulated water was first proposed by Mr. T. Gray. § 138. Coppering Aluminium. A good adherent deposit of copper on aluminium used to be considered a desideratum in the days when it afforded the only means of soldering the latter. Many receipts have been published from time to time, and I have tried, I think, most of them. On no occasion, however, till this year (1896), have I succeeded in obtaining a deposit which would not strip after it was tinned and soldered, though it is not difficult to get apparently adherent deposits so long as they are not operated upon by the soldering iron. The best of the many solutions which have been proposed in years gone by is very dilute cupric nitrate with about 5 per cent of free nitric acid. The problem of electroplating aluminium which I have indicated as awaiting a solution has at last found one. In the Archives des Sciences physiques et naturelles de Genève for December 1895 (vol. xxxiv. p. 563) there is a paper by M. Margot on the subject, which discloses a perfectly successful method of plating aluminium with copper. The paper itself deals in an interesting way with the theory of the matter--however, the result is as follows. (1) The aluminium articles are boiled for a few minutes in a strong solution of ordinary washing soda. The aluminium surface is thus corroded somewhat, and rendered favourable to the deposit of an adherent film of copper. After removal from the soda solution the aluminium is well washed and brushed in running water. (2) The articles are dipped for thirty seconds or so in a hot 5 per cent solution of pure hydrochloric acid. (3) After dipping in the hydrochloric acid, the work is instantly plunged into clean water for about one second, so as to remove nearly, but not quite, all of the aluminium chloride. (4) The work is transferred to a cold dilute (say 5 per cent) solution of cupric sulphate slightly acidulated with sulphuric acid. The degree of acidulation does not appear to be very important, but about one-tenth per cent of strong acid does well. If the preliminary processes have been properly carried out the aluminium will become coated with copper, and the process is accompanied by the disengagement of gas. It appears to be a rule that if gas is not given off, the film of copper deposited is non-adherent. The work must be left in the copper sulphate solution till it has received a uniform coating of copper. (5) When this is the case the work is removed--well washed so as to get rid of the rest of the aluminium chloride, and then electroplated by the battery in the ordinary copper sulphate bath. If the operation (4) does not appear to give a uniform coat, or if gas is not evolved from every part of the aluminium surface, I find that operations (2) and (3) may be repeated without danger, provided that the dip in the hydrochloric acid is shortened to two or three seconds. The copper layer obtained by Margot's method is perfectly adherent--even when used as a base for ordinary solder--though in this case it can be stripped if sufficient force is applied. Since the solder recommended by M. Margot for aluminium contains zinc, it does not run well when used to unite aluminium to copper, brass, iron, etc. In this case, therefore, I have found the most advantageous method of soldering to be by way of a preliminary copper-plating. The success of M. Margot's method depends in my experience on obtaining just the proper amount of aluminium chloride in contact with the aluminium when the latter is immersed in the copper sulphate solution. § 139. The process of copper-plating from sulphate or nitrate may, according to Mr. Swan (Journal of the Royal Institution, 1892, p. 630), be considerably accelerated by the addition of a trace of gelatine to the solution. As success appears to depend upon hitting the exact percentage amount of the gelatine, which must in any case be but a fraction of one per cent, and as Mr. Swan refrains from stating what the amount is, I am unable to give more precise instructions. A few experiments made on the subject failed, doubtless through the gelatine content not having been rightly adjusted. Mr. Swan claims to be able to get a hard deposit of copper with a current density of 1000 amperes per square foot, but seems to recommend about one-tenth of that amount for general use. The solution employed is a mixture of nitrate of copper and ammonium chloride--proportions not stated. Electrolytic copper, as generally prepared, is very pure, but this is a mere accident depending on the impurities which, as a rule, have to be got rid of. Electrolysis seems to have no effect in purifying from arsenic, for instance. Roughly speaking, about 11 grms. of copper are deposited per ampere hour from cupric salt solutions. When the current density is too high the anode suffers by oxidation, and this introduces a large and very variable resistance into the circuit. § 140. Alkaline Coppering Solution Coppering Base Metals. It is often desirable to coat lead, zinc, pewter, iron, etc, with a firm and uniform layer of copper preparatory to gilding or silvering. If copper or brass articles are soldered with soft solder it is found that the solder does not become silvered or gilt along with the rest of the material, but remains uncoated and of an ugly dark colour. This defect is got over by giving a preliminary coating of copper. This is done in an alkaline solution, generally containing cyanogen and ammonia. The following method has succeeded remarkably well with me. The receipt was taken originally from Gore's Electro-metallurgy, p. 208. A solution is made of 50 grms. of potassium cyanide (ordinary commercial, say, 75 per cent) and 30 grms. of sodium bisulphite in I.5 litres of water. Thirty-five grammes of cupric acetate are dissolved in a litre of water, and 20 cubic centimetres of the strongest liquid ammonia are added. The precipitate formed must be more or less dissolved to a strong blue solution. The cyanide and bisulphite solution is then added with warming till the blue colour is destroyed. This usually requires the exact amount of cyanide and bisulphite mentioned, but I have not found it essential to entirely destroy the colour. The solution contains cuprocyanide of sodium and ammonium (?), which is not very soluble, and this salt tends to be deposited in granular crystalline masses on standing. However, at a temperature of 50° C. the above receipt gives an excellent coppering liquid, which will coat zinc with a fine reguline deposit. Brass or copper partly smeared with solder will receive a deposit of copper on the latter as well as on the former, and, moreover, a deposit which appears to be perfectly uniform. In using the bath the anode tends, as a rule, to become incrusted, and this rapidly increases the resistance of the cell, so that the current falls off quickly. The articles should be scratch-brushed and plated for about two minutes with a current density of about ten ampères per square foot. As soon as the deposit begins to look red the articles are to be removed and rebrushed, after which the process may be continued. About five minutes' plating will give a copper deposit quite thick enough after scratch-brushing to allow of a very even gilding or silvering. Aluminium appears to be fairly coated, but, as usual, the copper strips after soldering. Iron receives an excellent and adherent coat. I do not think that the formation of a crust upon the anode can be entirely prevented. According to Gore, its formation is due to the solution being too poor in copper, but I have added a solution of the acetate of copper and ammonium till the colour was bright blue without in any way reducing the incrustation. If the solutions become violently blue it is perhaps as well to add a little more cyanide and bisulphite, but I have not found such an addition necessary. The process is one of the easiest and most satisfactory in electro-metallurgy. § 141. Nickel-plating. An examination of several American samples of nickel-plated goods has disclosed that the coating of nickel is, as a rule, exceedingly thin. This is what one would expect from laboratory repetition of the processes employed. Commercial practice in the matter of the composition of nickelling solutions appears to vary a good deal. Thin coatings of nickel may be readily given in a solution of the double sulphate of nickel and ammonia, which does rather better if slightly alkaline. Deposits from this solution, however, become gray if of any thickness, and, moreover, are-apt to flake off the work. The following solution has given very good results with me. It is mentioned, together with others, in the Electrical Review, 7th June 1895. The ingredients are:- Nickel sulphate 5 parts Ammonia sufficient to neutralise the nickel salt. Ammonium tartrate 3.75 parts Tannin 0.025 parts Water 100 parts The nickel sulphate and ammonia are dissolved in half the water, the ammonium tartrate in the other half with the tannin. The solutions are mixed and filtered at about 40° C. This solution works well at ordinary temperatures, or slightly warm, with a current density of ten ampères per square foot. In an experiment made for the purpose I found that plating may go on for an hour in this solution before the deposit begins to show signs of flaking off. The deposit is of a fine white colour. The resistance of the bath is rather high and rather variable, consequently it is as well to have a current indicator in circuit, and it may well happen that five or six volts will be found requisite to get the current up to the value stated. For nickelling small objects of brass, such as binding screws, etc, it is very necessary to be careful as to the state of polish and uniformity of their surfaces before placing them in the plating bath. A polished surface will appear when coated as a polished surface, and a mat surface as a mat surface; moreover, any local irregularity, such as a speck of a foreign metal, will give rise to an ugly spot in the nickelling bath. For this reason it is often advisable to commence with a coat of copper laid on in an alkaline solution and scratch-brushed to absolute uniformity. An examination of the work will, however, disclose whether such a course is desirable or not; it is not done in American practice, at all events for small brass objects. These are cleaned in alkali and in boiling cyanide, which does not render a polished surface mat, as weak acid is apt to do, and are then coated with a current density of about ten ampères per square foot. In spite of what is to be found in books as to the ease with which nickel deposits may be polished, I find that the mat surface obtained by plating on an imperfectly polished cathode of iron is by no means easily polished either by fine emery, tripoli, or rouge. Consequently, as in the case of brass, if a polished surface is desired, it must be first prepared on the unplated cathode. In this case, even if the deposit appears dull, but not gray, it may be easily polished by tripoli and water, using a cork as the polisher. Scratch-brushing with brass wire, however, though possibly not with German silver wire, brightens the deposit, but discolours it. When the deposit becomes gray I have not succeeded in polishing it satisfactorily. Soldered brass or iron may be satisfactorily coated with nickel by giving it a preliminary coating of copper in the cyanide bath. On the whole, I recommend in general that iron be first coated with copper in the alkaline bath, scratch-brushed, and then nickel-plated, and this whether the iron appears to be uniform or not. Much smoother, thicker, and stronger coats of nickel are obtained upon the copper-plated surface than on the iron one, and the coating does not become discoloured (? by iron rust) in the same way that a coating on bare iron does. The copper surface may be plated for at least an hour at a density of ten ampères per square foot without scaling. Scales or circles divided on brass may be greatly improved in durability by nickel--plating. For this purpose the brass must be highly polished and divided before it is nickelled. The plating should be continued for a few minutes only, when a very bright but thin coat of nickel will be deposited; it then only remains to wash and dry the work, and this must be done at once. If the nickel is deposited before the scale or circle is engraved, very fine and legible divisions are obtained, but there is a risk that flakes of nickel may become detached here and there in the process of engraving. 142. Miscellaneous Notes on Electroplating. Occasionally it is desirable to make a metallic mould or other object of complex shape. The quickest way to do this is to carve the object out of hard paraffin, and then copy it by electrotyping. Electrotype moulds can be made in many ways. The easiest way perhaps is to take a casting in plaster of Paris, or by means of pressure in warm gutta-percha. In cases where the mould will not draw, recourse must be had to the devices of iron-founders, i.e. the plaster cast must be made in suitable pieces, and these afterwards fitted together. This process can occasionally be replaced by another in which the moulding material is a mixture of treacle and glue. The glue is soaked in cold water till it is completely soft. The superfluous water thrown away, one-fourth part by volume of thick treacle is added, and the mixture is melted on the water bath; during which process stirring has to be resorted to, to produce a uniform mixture. This liquid forms the moulding mixture, and it is allowed to flow round the object to be copied, contained in a suitable box, whose sides have been slightly oiled. The object to be copied should also be oiled. After some hours, when the glue mixture has set, it will be found to be highly elastic, so that it may be pulled away from the mould, and afterwards resume very nearly its original form. One drawback to the use of these moulds lies in the fact that the gelatine will rarely stand the plating solution without undergoing change, but this may be partially obviated by dipping it for a few seconds in a 10 per cent solution of bichromate of potash, exposing it to the sunlight for a few minutes, and then rinsing it. In order to render the surface conducting, it is washed over with a solution of a gold or silver salt, and the latter reduced in situ to metal by a suitable reagent. A solution of phosphorus is the most usual one (see Gore, Electro-metallurgy, p. 216). Such a mould may be copper-plated in the sulphate bath, connection being made by wires suitably thrust into the material. Plaster of Paris moulds require to be dried and waxed by standing on a hot plate in melted wax before they are immersed in the plating bath. In this case the surface is best made conducting either by silvering it by the silvering process used for mirrors, or by brushing it over with good black lead rendered more conducting by moistening with an ethereal solution of chloride of gold and then drying in the sun. The brushing requires a stiff camel's-hair pencil of large size cut so that the hairs project to a distance of about a quarter of an inch from the holder. The brushing must continue till the surface is bright, and is often a lengthy process. The same process of blackleading may be employed to get a coat of deposited metal which will strip easily from the cathode. In all cases where extensive deposits of copper are required, the growth takes place too rapidly at the corners. Consequently it is often desirable to localise the action of the deposit. A "stopping" of ordinary copal varnish seems to be the usual thing, but a thin coat of wax or paraffin or photographic (black) varnish does practically as well. I do not propose to deal with the subject of electrotyping to any extent, for if practised as an art, a good many little precautions are required, as the student may read in Gore's Electro-metallurgy. The above instructions will be found sufficient for the occasional use of the process in the construction of apparatus, etc. There is no advantage in attempting to hurry the process, a current density of about ten ampères per square foot being quite suitable and sufficiently low to ensure a solid deposit. § 143. Blacking Brass Surfaces. A really uniform dead-black surface is difficult to produce on brass by chemical means. A paste of nitrate of copper and nitrate of silver heated on the brass is said to give a dead-black surface, but I have not succeeded in making it act uniformly. For optical purposes the best plan is to use a paint made up of "drop" black, ground very fine with a little shellac varnish, and diluted for use with alcohol. No more varnish than is necessary to cause the black to hold together should be employed. In general, if the paint be ground to the consistency of very thick cream with ordinary shellac varnish it will be found to work well when reduced by alcohol to a free painting consistency. A very fine gray and black finish, with a rather metallic lustre, may be easily given to brass work. For this purpose a dilute solution of platinum tetrachloride (not stronger than 1 per cent) is prepared by dissolving the salt in distilled water. The polished brass work is cleaned by rubbing with a cork and strong potash till all grease has disappeared, as shown by water standing uniformly on the metal and draining away without gathering into drops. After copious washing the work is wholly immersed in a considerable volume of the platinum tetrachloride solution at the ordinary temperature. After about a quarter of an hour the brass may be taken out and washed. The surface will be found to be nicely and uniformly coated if the above instructions have been carried out, but any finger-marks or otherwise dirty places will cause irregularity of deposit. If the process has been successful it will be found that the deposit adheres perfectly, hardly any of it being removed by vigorous rubbing with a cloth. If the deposit is allowed to thicken--either by leaving the articles in the solution too long or heating the solution, or having it too strong--it will merely rub off and leave an irregular surface. This process succeeds well with yellow brass and Muntz metal, either cast or rolled, but it does not give quite such uniform (though still good) results with gun-metal, on which, however, the deposit is darker and deader in appearance. A book might be written (several have been written) on the art of metal colouring, but though doubtless a beautiful and delicate art, it is of little service in the laboratory. For further information the reader may consult a work by Hiorns. § 144. Sieves. Properly graded sieves with meshes of a reliable size are often of great use. They should be made out of proper "bolting" cloth, a beautiful material made for flour-millers. Messrs. Henry Simon and Company of Manchester have kindly furnished me with the following table of materials used in flour-milling. Sieves made of these materials will be found to work much more quickly and satisfactorily than those made from ordinary muslin or wire gauze. Relative Bolting Value of Silk, Wire, and Grit Gauze Threads per inch Trade No. Trade No. Trade No. of Approximate. of Silk. of Wire. Grit Gauze. 18 0000 18 16 22 000 20 20 28 00 26 26 38 0 32 34 48 1 40 44 52 2 45 50 56 3 50 54 60 4 56 58 64 5 60 60 72 6 64 66 80 7 70 70 84 8 80 80 94 9 106 10 114 11 124 12 130 13 139 14 148 15 156 16 163 17 167 18 170 19 173 20 § 145. Pottery making in the Laboratory. When large pieces of earthenware of any special design are required, recourse must be had to a pottery. Small vessels, plates, parts of machines, etc, can often be made in the laboratory in less time than it would take to explain to the potter what is required. For this purpose any good pipeclay may be employed. I have used a white pipe-clay dug up in the laboratory garden with complete success. The clay should be kneaded with water and squeezed through a cloth to separate grit. It is then mixed with its own volume or thereabouts of powdered porcelain evaporating basins, broken basins being kept for this purpose. The smoothness of the resulting earthenware will depend on the fineness to which the porcelain fragments have been reduced. I have found that fragments passing a sieve of sixty threads to the inch run, do very well, though the resulting earthenware is decidedly rough. The porcelain and clay being thoroughly incorporated by kneading, the articles are moulded, it being borne in mind that they will contract somewhat on firing. [Footnote: The contraction depends on the temperature attained as well as on the time. An allowance of one part in twelve will be suitable in the case considered.] The clay should be as stiff as is convenient to work, and after moulding must be allowed to get thoroughly dry by standing in an airy place; the drying must not be forced, especially at first, or the clay will crack. Small articles are readily fired in a Fletcher's crucible furnace supplied with a gas blow-pipe; the furnace is heated gradually to begin with. When a dull red heat is attained, the full power of the blast may be turned on, and the furnace kept at its maximum temperature for three or four hours at least, though on an emergency shorter periods may be made to do. The articles are supported on a bed of white sand; after firing, the crucible furnace must be allowed to cool slowly. It must be remembered that the furnace walls will get hot externally after the first few hours, consequently the furnace must be supported on bricks, to protect the bench. The pottery when cold may be dressed on a grindstone if necessary. This amateur pottery will be found of service in making small fittings for switch-boards, commutators, and in electrical work generally. Pottery made as described is very hard and strong, the hardness and strength depending in a great degree on the proportion of powdered porcelain added to the clay, as well, of course, as on the quality of both of these materials. It is a good plan to knead a considerable quantity of the mixture, which may then be placed in a well-covered jar, and kept damp by the addition of a little water. Pottery thus made does not require to be glazed, but, of course, a glaze can be obtained by any of the methods described in works on pottery manufacture. The following glaze has been recommended to me by a very competent potter:- Litharge 7 parts by weight Ground flint 2 parts by weight Cornish stone or felspar 1 parts by weight These ingredients are to be ground up till they will pass the finest sieve--say 180 threads to the inch. They are then mixed with water till they form a paste of the consistency of cream. They must, of course, be mixed together perfectly. The ware to be glazed is dipped into the cream after the first firing; it is then dried as before and refired. The glaze will melt at a bright red heat, but it will crack if not fired harder; the harder it is fired the less likely is it to crack. If colouring matters are added they must be ground in a mill free from iron till they are so fine that a thick blanket filter will not filter them when suspended in water. This remark applies particularly to oxide of cobalt. APPENDIX PLATINISING GLASS IN the Philosophical Magazine for July 1888 (vol. xxvi. p. 1) there is a paper by Professor Kundt translated from the Sitzungsberichte of the Prussian Academy. This paper deals with the indices of refraction of metals. Thin prisms were obtained by depositing metals electrolytically on glass surfaces coated with platinum. The preparation of these surfaces is troublesome. Kundt recounts that no less than two thousand trials were made before success was attained. A detailed account of the preparation of these surfaces is not given by Kundt, but one is promised--a promise unfortunately unfulfilled so far as I am able to discover. A hunt through the literature led to the discovery of the following references: Central Zeitung fuer Optik und Mechanik, p. 142 (1888); Dingler's Polytechnik Journal, Vol. cxcv. p. 464; Comptes Rendus, vol. lxx. (1870). The original communication is a paper by Jouglet in the Comptes Rendus, of which the other references are abstracts. The account in Dingier is a literal translation of the original paper, and the note in the Central Zeitung is abbreviated sufficiently to be of no value. The details are briefly as follows:- One hundred grams of platinum are dissolved in aqua regia and the solution is dried on the sand bath, without, however, producing decomposition. Though the instructions are not definite, I presume that the formation of PtCl4 is contemplated. The dried salt is added little by little to rectified oil of lavender, placed on a glass paint-grinding plate, and the salt and oil are ground together with a muller. Care is required to prevent any appreciable rise of temperature which would decompose the compound aimed at, and it is for this reason that the salt is to be added gradually. Of course the absorption of water from the air must be prevented from taking place as far as possible. Finally, the compound is diluted by adding oil of lavender up to a total weight of 1400 grams (of oil). The liquid is poured into a porcelain dish and left absolutely at rest for eight days. It is then decanted and filtered, left six days at rest, and again decanted (if necessary). The liquid should have a specific gravity of 5° on the acid hydrometer. (If by this the Baumé scale is intended, the corresponding specific gravity would be 1.037.) A second liquid is prepared by grinding up 25 grams of litharge with 25 grams of borate of lead and 8 to 10 grams of oil of lavender. The grinding must be thoroughly carried out. This liquid is to be added to the one first described, and the whole well mixed. The resulting fluid constitutes the platinising liquid, and is applied as follows:- A sheet of clean glass is held vertically, and the liquid is painted over it, carrying the brush from the lower to the upper edge. The layer of oil dries slowly, and when it is dry the painting is again proceeded with, moving the brush this time from right to left; and similarly the process is repeated twice, the brush being carried from top to bottom and left to right. This is with the object of securing great uniformity in the coating. Nothing is said as to the manner in which the glass is to be dried. The dried glass is finally heated to a temperature of dull redness in a muffle furnace. The resinous layer burns away without running or bubbling, and leaves a dull metallic surface. As the temperature rises this suddenly brightens, and we obtain the desired surface (which probably consists of an alloy of lead and platinum). It is bright only on the surface away from the glass. I have not had an opportunity of trying this process since I discovered the detailed account given by Jouglet; but many modifications have been tried in the laboratory of the Sydney University by Mr. Pollock, starting from the imperfect note in the Central Zeitung, which led to no real success. It was found that it is perfectly easy to obtain brilliant films of platinum by the following process, provided that the presence of a few pin-holes does not matter. The platinum salt employed is what is bought under the name of platinic chloride; it is, however, probably a mixture of this salt and hydro-chloro-platinic acid, and has all the appearance of having been obtained by evaporating a solution of platinum in aqua regia to dryness on the water bath. A solution of this salt in distilled water is prepared; the strength does not seem to matter very much, but perhaps one of salt to ninety-nine water may be regarded as a standard proportion. To this solution is added a few drops of ordinary gum water (i.e. a solution of dextrin). The exact quantity does not matter, but perhaps about 2 per cent may be mentioned as giving good results. The glass is painted over with this solution and dried slowly on the water bath. When the glass is dry, and covered with a uniform hard film of gum and platinum salt free from bubble holes, it is heated to redness in a muffle furnace. The necessary and sufficient temperature is reached as soon as the glass is just sensibly red-hot. The mirrors obtained in this way are very brilliant on the free platinum surface. If the gum be omitted, the platinum will have a mat surface; and if too much gum be used, the platinum will get spotty by bubbles bursting. There does not appear to be any advantage in using lead. It is quite essential that the film be dry and hard before the glass is fired. 
40411	----	TRANSCRIBER'S NOTE In the numerous chemical formulae a subscripted number is shown as _{2}, so the familiar formula for water would be H_{2}O: H, subscript 2, O. This notation is needed to distinguish digits that are subscripts from digits that are multipliers, as for example in the formula Pb(OH)_{2}2PbCO_{3}, where the subscript 2 must be distinguished from the quantity multiplier 2 that follows it. [Illustration: _Frontispiece_ STONEWARE MADE BY THE AUTHOR.] The Potter's Craft A Practical Guide for the Studio and Workshop _By_ CHARLES F. BINNS _Director of the New York State School of Clay-Working and Ceramics_ ¶ _Some time a Superintendent in the Royal Porcelain Works, Worcester, England_ _SECOND EDITION_ _SECOND PRINTING_ _26 PLATES AND 20 TEXT ILLUSTRATIONS_ [Colophon] NEW YORK D. VAN NOSTRAND COMPANY, INC. EIGHT WARREN STREET Copyright, 1910, 1922 by D. Van Nostrand Company _All rights reserved, including that of translation into the Scandinavian and other foreign languages._ Printed in the United States of America LANCASTER PRESS, INC. LANCASTER, PA. "A book is written, not to multiply the voice merely, not to carry it merely, but to perpetuate it. The author has something to say which he perceives to be true and useful, or helpfully beautiful. So far as he knows, no one has yet said it; so far as he knows, no one else can say it. He is bound to say it clearly and melodiously if he may; clearly, at all events." --_Ruskin._ PREFACE TO SECOND EDITION Since the publication of the first edition of this book eleven years have elapsed, years packed full of varied and interesting experiences. During that time it has been the pleasant fortune of the author to conduct classes, especially summer classes, in the science and art of pottery production. These have been occasions of meeting many fine and noble personalities whom to know is a liberal education. As one of the consequences of these experiences the book has been revised and some new chapters have been written. Especial acknowledgments are due and are gratefully made to Elsie Binns for the chapter on Clay-Working for Children and to Maude Robinson for that on Alkaline Glazes. The photographs are by the Taylor Studios, Hornell, N. Y. C. F. B. Alfred, New York. March, 1922. PREFACE TO FIRST EDITION This Book is the outcome of an experience extending over a period of thirty-six years. Twenty years ago it would have been impossible, for the science of ceramics was not then born. Ten years ago it would have been wasted for the Artist-potter in America had not arrived, but now the individual workers are many and the science is well established. Written teaching must be imperfect, but I have endeavored to set down the exact methods by which my students are taught, in the hope that those who cannot secure personal instruction may read and understand. As far as possible didactic statements have been avoided and the attempt has been made to lead every student to experiment and to think for himself. In other words, I have tried to erect sign-posts and occasional warnings rather than to remove all obstacles from the road. C. F. B. Alfred, N. Y. January, 1910. CONTENTS Introduction.--The Present Need xiii CHAPTER I. Applied Art 1 II. Pottery 9 III. Porcelain 23 IV. The Nature and Properties of Clay 29 V. The Preparation of Clay 37 VI. Mold-Making and Plaster 43 VII. Cases and Working Molds 58 VIII. Building by Hand 68 IX. The Potter's Wheel 74 X. Turning 99 XI. Making Large Pieces 107 XII. Cups and Saucers and Plates 124 XIII. Casting 129 XIV. Tiles 133 XV. Glazes and Glazing Part I 140 Part II--Matt Glazes 152 Part III--Fritted Glazes 157 Part IV--Recipes 160 Part V--The Defects of Glazes 164 Part VI--Alkaline Glazes 167 XVI. Decoration 173 XVII. The Fire 179 XVIII. High Temperature Wares 188 XIX. Clay-working for Children 194 INDEX 201 LIST OF PLATES Frontispiece.--Stoneware made by the Author. PLATE. PAGE I. Throwing.--Lesson II, 1 80 II. Throwing.--Lesson II, 2 81 III. Throwing.--Lesson II, 3 82 IV. Throwing.--Lesson III, 1 83 V. Throwing.--Lesson III, 2 86 VI. Throwing.--Lesson IV, 1 87 VII. Throwing.--Lesson IV, 2 89 VIII. Throwing.--Lesson V 90 IX. Throwing.--Lesson VI, 1 92 X. Throwing.--Lesson VI, 2 93 XI. Throwing.--Lesson VII 95 XII. Throwing.--Lesson VIII, 1 96 XIII. Throwing.--Lesson VIII, 2 97 XIV. Making Large Pieces. The First Section 109 XV. Making Large Pieces. Measuring the Foundation of the 110 Second Section XVI. Making Large Pieces. Drawing up the Second Section 111 XVII. Making Large Pieces. Shaping the Third Section 112 XVIII. Making Large Pieces. The Three Sections Completed 113 XIX. Making Large Pieces. Turning the Edge of the First 114 Section XX. Making Large Pieces. Finishing the Bottom of the First 116 Section XXI. Making Large Pieces. Checking the Size of the Second 117 Section XXII. Making Large Pieces. Fitting Together Dry 119 XXIII. Making Large Pieces. Setting the Third Section in Place 120 XXIV. Making Large Pieces. The Three Sections Set Together in 121 the Rough XXV. Making Large Pieces. The Finished Vase 122 INTRODUCTION: THE PRESENT NEED Many times it has been proven, in the history of the world, that it is not possible to force a reform or a novelty upon an unwilling people. Such things are organic. In order to live they must grow and in order to grow must live. No attempt will be made, therefore, in these pages to foster an idea or propound a thought which may exist only in the predilection of the author. The trend of the present demand, a persistent growth of several years, is towards a personal and individual expression in the crafts or industrial arts. This tendency is the natural swing of the pendulum from the machine-made product of the manufactory which in its turn was the inevitable result of mechanical invention. When the artisan was an artist and the designer a craftsman, there was but a limited production of industrial art. The articles made were expensive and for the wealthy alone. The common utensils necessary to the household were made on the farm and were of the rudest possible character. But with the gradual development of machinery there came an abandonment of rural activities, a flocking to the city, manufacturing on a large scale, lower prices, and a huge output. This has, of course, taken many years to develop, but the utmost limit of the swing has been reached and the question is "What next?" Will the factory cease its labors? Will output decrease in bulk and improve in quality? Will there ever, in a word, be a return to medieval conditions? Not only may all these questions be answered in the negative but it may be stated with all sincerity that there is no need for any other answer. What then, are not manufactured products as now put forth a menace to the art life of the nation? Are not the people being educated in the use of and belief in machine-made ornament and meretricious display? Perhaps so, but no good purpose will be served by a ruthless condemnation of these things. Art appreciation is a most subtle thing and no one may dictate to his neighbor as to what he should or should not admire. It took time for the public to understand and patronize the product of the machine even though the price was favorable. It will take time for an appreciation of craftsmanship to influence the land but this consummation will most assuredly come. On the one hand there is the manufactory, teeming with "hands," riotous with wheels, turning out its wares by the thousand and supplying the demand of the many; on the other, there is the artist-artisan. He labors at his bench in sincere devotion to his chosen vocation. His work is laborious and exacting, he can make but a few things and for them he must ask a price relatively high. Both these conditions are necessary. The craftsman cannot supply the need of the people and the manufacturer has no time or thought for disinterested production. Herein lies the need and here is the mission of the individual worker. In every age it is given to some to discern more than the multitude and it is theirs to teach. The people are anxious to learn, are eager to be led. What they demand will be manufactured and so by the irresistible lever of public opinion the man at the bench, if he be true to himself and to his craft, may move the millionaire manufacturer to make wares which, if not truly artistic, shall at least be inoffensive. Such a mission is not to be accomplished without suffering. The man who essays to attack a giant must be sure both of his ground and of his personal condition. He who would establish his craft in the knowledge and affection of men must possess enthusiasm, skill, discrimination and infinite patience. It is not enough to discern the good, the hand must follow the brain with diligent care. Furthermore, it is not enough to be able to make things well, one must also make them good and know it. The artist-artisan must have courage to destroy that which is below standard, and self-denial to resist the temptation to sell an unworthy product. The country needs craftsmen of this type and for them there is an important work. For such, if they elect to join the ranks of the potters, these words are written and in the hope that some may be stimulated, encouraged, guided and helped the counsel of a fellow craftsman is offered. CHAPTER I: APPLIED ART It is not intended, in these lines, to consider what are generally termed the Fine Arts, painting and sculpture. These are perfectly competent to take care of themselves and, indeed, the author can make no claim to an ability to discuss them. In the field of applied art, however, there are certain principles to be observed, principles, moreover, which are frequently lost sight of because of the lamentable separation of the functions of the artist and artificer. It is extremely difficult to draw the line between art and manufacture. For example, a wall paper, designed with skill and executed by machinery in actual reproduction of the work of the designer; is it a work of art or is it a product of the factory? It is both. Primarily a work of art is the product of the artist's own hand. It reveals his individuality. It is the language in which he expresses himself to his audience. It is the note of his voice. Such a work may or may not appeal to a large section of the public. This will always be so. An artist, be he poet, musician, painter or craftsman, is one who can see more than others. What he sees he endeavors to express but it is inevitable that he be sometimes misunderstood. Hence it the more necessary that his message be delivered at first hand. To look upon a replica of the work of an artist is like reading a sermon or an oration from a printed page. One may gather much of the teaching but the personal note, the tone and gesture, must be lost. But there are many who can gather the words of great men only from books. There are, moreover, books which have never been spoken and wherein alone the message is to be found. In like manner there are works, emanating from the hand of great designers which can only be made available for the many in a form of reproduction. The wall paper cited as an illustration is of this class. Were it not for the printing press this beautiful design could not have passed beyond the studio, and while it is a great thing if a wealthy man can commission a Whistler to decorate a peacock room, it is an advantage by no means to be ignored that a well designed wall paper can be purchased by the piece. But while this is true of such of the household goods as cannot be procured except by the medium of the machine, there are other examples. In the case of the wall paper the function of the machine is simply to transfer the proper design to the paper itself. This has no identity except as a surface. It is no more to be considered than is a canvas upon which a picture is painted. But when a chair or a table is formed out of pieces of lumber uniformly shaped by one machine, the seat or top put together by another and the legs or back carved or stamped by a third, art or individuality is lost because mechanical construction is involved. Still more is this the case in the product of the manufactory of pottery. In commercial practice not only is a shape designed without regard to decoration but the same decoration is placed upon several forms, or a single form is made to suffer as the vehicle for many decorations. Some of the results may be pleasing, even beautiful, but it is more by luck than guidance and no piece produced in this way has any claim to be classed as a work of art. On the other hand it may happen that a work of art, in the sense of individual expression, may not even be beautiful and one is tempted to ask the reason. If a work which is a genuine expression of a man's personality fail to please the senses of those who are trained in the finer perceptions there must be something wrong. If the adverse opinion be at all general amongst the critics it may be assumed that they are right and that the worker is wrong. For example, the form of a flower is not a fit receptacle for a candle. It often happens that a designer, struck with the beauty of, say, a tulip, has modeled the flower in clay and made it into a candlestick. Now it is obvious that the more closely the model simulates the flower the less appropriate it is for such a purpose. If the model be heavy enough to be of use it must be far removed from its prototype. If a conventional design for a candlestick be adopted the petals of a flower may be shown in relief upon it but there must always be a solid foundation to account for the possibility of use. A favorite form with some designers is a bird's nest made into a flower holder. In this the same criticism applies. A bird's nest is always built to let water escape. Even a mud-lined nest is not impervious and the idea is obviously inappropriate. It is important that imitation be avoided and especially the imitation of material. One often hears the remark "How beautiful, it looks just like bronze." This, of course, comes from the casual observer to whom the skill of the imitation appeals but it cannot be too strongly insisted upon that to imitate one material in another is false from every point of view. Nor is it necessary. Clay is sufficient in itself. There are so many effects possible in pottery which are not possible in any other medium that it is entirely superfluous to seek outlandish texture and color. To be sure, such things are popular but that does not make them sound in principle or true in taste. It should not be a purpose of any craft to make pieces merely as an exhibition of skill. This is done sometimes by such versatile workers as the Japanese, but it may be laid down as a law that a production of the nature of a _tour-de-force_, an object which simply excites wonder at the skill of the worker, is undignified and meretricious. It is akin to the work of certain painters who delight in painting marble or velvet so as to exhibit a perfect texture only and is but one degree removed from the skill of the pavement artist who with colored chalk draws a lamb chop or a banana in such a manner that the real article seems to be lying on the ground at his feet. The true artist, be he potter or painter, works primarily for his own satisfaction. It sometimes happens that a defect, not large enough to be obvious, is a temptation to concealment. The public will never know. But the consciousness of the existence of such a blemish will destroy the pride of achievement which should accompany every finished piece. If the worker aims to draw any expression of opinion from the untrained observer it should be in the nature of a remark on how easy the work looks. Art will always conceal effort. Just as the poet or orator is at his best when he clothes sublime thought in simple words so the artist or craftsman glorifies his vocation when he makes use of means which appear to be within the reach of every observer. In addition to the work of the producer there must be considered the function of the critic. Artists are commonly impatient of criticism. Tennyson voiced this sentiment when he wrote of "Irresponsible indolent reviewers," but the power of the critic is rarer than the skill of the craftsman. True, there are critics and critics. There is the man who knows what he likes and who cannot be persuaded that he likes what is false, and there is the trained critic who sees with an educated eye and dissects with an unerring word. It is not common to find critic and craftsman in one and the same person and it not infrequently happens that the persons exercising these functions are at variance with each other. But if the critic be correct why is the craftsman wrong? In this let it be presumed that there is nothing wrong with his craft as such; that he handles his tools skilfully and has perfect control over his material. More than this, however, is necessary. The first requirement is a sense of form, a term which includes outline, proportion and structure. Often and often it is found that a designer depends upon novelty alone for acceptance. He is not altogether to blame in this for the great American public will, more often than not, ask, "Is it new?" Novelty in itself is no claim to consideration; in fact, on being shown some product of which it is said "Nothing like it has ever been seen before," the temptation is great to respond, "May its like never be seen again." Novelty apart, form must possess proportion, balance and grace. A chair must invite the sitter, a vase must stand securely, a carpet must lie flat. The absence of these things may evidence an individuality on the part of the designer but it is art at the expense of truth. The second necessary condition is fitness which again is expressed in several ways. A porcelain vase is required to be light, graceful and refined. A piece of ruder pottery may be no less satisfactory if it exhibit vigor, strength and solidity. A large pot for a growing tree is, for these reasons, more appropriate in grès than in porcelain. Porcelain is translucent but such a quality is of no advantage in the case of a flower pot; the strength of a massive body is, however, demanded by the circumstances of use and hence the unfitness of the one and the fitness of the other. Another point of fitness is concerned in the correspondence between size, form and weight. It often happens that one takes hold of a piece of pottery and experiences a shock. The mind unconsciously forms an estimate of what the weight will be but the piece does not respond. The effort put forth in accordance with the appearance of the object either lifts it suddenly into the air or fails to raise it from the table. The artist critic takes note of these things. To handle his wares is a constant pleasure, for one is not continually disappointed by unexpected violences. This correspondence or equilibrium is apart from the use of a piece of pottery. It is quite as legitimate to express one's ideas in clay in the presentation of simple beauty as it is to express them with paint upon canvas. At the same time there is always a satisfaction in a vase or flower pot that it can be used if required. Thus a vase which will not hold water is technically imperfect and the _bête noire_ of the conscientious potter. It is in the harmony of these things that the rôle of the critic is seen to advantage. If the artist be capable of criticizing his own work he is in a position to command attention but he must either discipline himself or be disciplined by others, which, after all, is the way of the world at large. CHAPTER II: POTTER It must always be an open question how much credit for artistic feeling can be given to primitive races. The production of pottery was, at first, the supplying of a need. Clay offered a medium for the making of household utensils which were at once fireproof and impervious. The work does not belong strictly to the earliest stages of civilization but is a development of advancing refinement.[A] [A] Those who wish to study Indian pottery in detail are referred to Dr. W. H. Holmes' work on the Aboriginal Pottery of the Eastern United States, published by the Smithsonian Institution, Washington, D. C. Crude and unprepared clays were used for the most part but the makers could scarcely have been conscious of the charming color-play produced by the burning of a red clay in a smoky fire. The pottery of the Indians is artistic in the sense of being an expression of an indigenous art and much of it is beautiful, though whether the makers possessed any real appreciation of beauty is open to doubt. The pottery was exclusively the work of the women. No wheel was employed but the ware was mainly constructed by coiling. Long strips of clay were rolled under the hands and made of uniform size and these were then coiled in spiral form, the rolls being welded together with water. After proceeding a certain height the walls of the growing jar would become weak under their own weight. The piece would then be set aside to undergo a partial hardening upon which the work would be carried forward another stage. The shape being completed and partially dried, the maker would work over the whole surface with stones or simple tools until the marks of the coils had disappeared and the walls had reached a sufficient thinness. A great deal of skill was exercised in accomplishing this. Many of the Indian forms are transitional. The basket, the gourd and the bark-made jar suggested their shapes to the potter; indeed it is sometimes evident that clay vessels were constructed as linings to wicker forms, the outer layer of twigs being afterwards burned off. The firing was performed in the open flame without any protection, a fact which accounts for the great irregularity found in quality and color. The decorations used by the Indian women were of the type common to unglazed wares. The clay was incised or embossed and natural earths were used as pigments. This accounts in great measure for the fitness which may be observed in aboriginal decoration. There is an absence of artificial coloring, nor is there any straining after effect, but instead there is shown a sober strength and a sane expression of values which would do credit to a modern designer. America is fortunate in possessing abundant relics of primitive times but it cannot be doubted that in other lands similar work was done, making allowance, of course, for the characteristic variations in national traits. The potter's craft is of such a nature, using an omnipresent material and requiring the minimum of tools, that almost every nation on the globe has practiced it. In some it has never been developed beyond the narrow limits of the stone age, in others it has reached the utmost perfection of cultured skill. For perfection of quality in crude pottery, no ware has ever surpassed that of Greece. It is not practicable here to deal with the numerous branches and sub-branches of Greek pottery; let it suffice for the present purpose to speak of only two main groups. In the first, the background of the decoration was supplied by the tint of the bare clay; in the second, this tint afforded the color of the decoration itself, the background being covered with a black pigment. To speak briefly these groups are known as black-figured and red-figured wares. The wheel was early adopted by the Grecian potters as a means of producing form and although molds were sometimes used, the wheel was, to all intents and purposes, the sole method of manufacture. Greek pottery is once fired. Birch classes it as glazed terra cotta, but the glaze is nothing more than the black pigment with which the decoration is carried out. The uncolored part of the clay is not glazed but polished with a hard tool. Probably some famous potters employed assistants either to make the pieces or to decorate but it does not appear that there was any reproduction, at least, during the best period. At first primitive ideas prevailed. Geometric designs were succeeded by rhythmic friezes of beasts and birds done in black. When the human figure made its appearance the faces were all in profile with full-fronting eye while the prominent details of feature and drapery were scratched with a sharp point before burning. The change of method to red on black gave much wider scope for the treatment of the human figure, rendered a fuller expression possible and enlarged the power of pictorial action. Great skill in drawing was manifested and details of both drapery and features were expressed with great care by means of the brush. Such was the state of the art when the decadence set in and the work fell into the hands of plagiarists and charlatans. Meretricious coloring and gaudy ornament succeeded the refinement and restraint of the earlier days and so the art perished. To the inventive power of the Romans the ceramic art owes more than one novelty. It would appear that the desideratum of the early days was a black ware. Homer in his hymn wrote: "Pay me my price, potters, and I will sing. Attend, O Pallas, and with lifted arm protect their ovens, Let all their cups and sacred vessels blacken well And baked with good success yield them Both fair renown and profit." The Greeks accomplished this blackening by means of a pigment, the Romans secured a similar result by a manipulation of the fire. It is well known that the oxide of iron which imparts to the clay a red color will, if burned in what is known as a "reducing" fire, turn black. This is accomplished by keeping the air supply at the lowest possible point and the effect is heightened by the smoke which is partly absorbed by the clay. This black ware is known as Upchurch pottery from the name of a locality in England where large quantities have been found, but numerous examples occur in Germany and, indeed, wherever the Roman hosts encamped. A second type of pottery is called Castor ware and consists of a dark clay upon which the decoration is traced in clay of a lighter color. The decoration was applied as a slip or cream and hence was the forerunner of the modern slip painting or _pâte-sur-pâte_. This ware is well worth a study. The decorations consisted largely of conventional borders and panels but it is specially notable on account of the free use of motives drawn from daily life. One of the commonest scenes depicted is the hunt of hare or stag, the animals and trees being often woven into an almost conventional frieze. The most valued type of Roman pottery seems to have been the Aretine or Samian ware. This is a bright red color and possesses an extremely thin glaze. A particular clay was evidently used, but all knowledge of its source has been lost. With the importation of Chinese porcelain by the Dutch the whole trend of pottery manufacture was changed. No longer was black a desirable color, white was seen to be much more delicate and beautiful and henceforth the endeavor of the potter was to produce a ware which should be as nearly like porcelain as possible. The crudeness of the clay kept this ideal from being realized, but various expedients were adopted and gradually better results were obtained. Throughout the East a type of white pottery was made which, though stimulated by the Chinese example, may have been a relic of the knowledge of the Egyptians. A crude clay was coated with a white preparation, possibly ground quartz, and upon this there were painted conventional designs in sombre colors. A clear glaze covered the whole and imparted to the colors a beautiful quality as of pebbles under water. The nature of the glaze is made evident by the hues assumed by the metallic oxides employed as colorants. Copper oxide affords a turquoise blue, manganese, a wine purple, and iron, a brick red. If the glaze had contained any considerable amount of lead oxide, these colors would have been quite different; copper would have produced green, manganese, dark brown, and iron, yellowish brown. The iron pigment was evidently a clay, sometimes spoken of as Armenian bole. The red color is always in raised masses because if a thin wash had been used the color would have yielded to the action of the glaze. This ware, commonly called Oriental _engobe_ ware, affords a fruitful study. Effects similar in character were produced by the late Theodore Deck of Paris, but no considerable use of the ancient methods has ever been attempted. The use of tin and lead in glazing was known to the Arabian and Moorish potters but these ingredients were not abundant in the East. When, however, the Moorish hosts conquered a part of Spain in the twelfth century it was found that both lead and tin were available. The result was the development of the enameled ware known by the generic name Maiolica. Some have maintained that this was first made in Italy but the name is derived from the island of Maiorca from which much of the pottery was exported. The famous Alhambra vase remains as a monument to the skill of the Hispano-Moresque craftsmen, but it was the Italian artists of the Renaissance who brought the enameled wares to perfection. The interest here is artistic and technical rather than historical, but no one can study the work of the period without learning something of Luca della Robbia and Giorgio Andreoli, of Gubbio and Pesaro and Castel Durante. The use of lead in the glaze proved seductive. It simplified the technical problems and provided a brilliant surface but alas! the colors suffered and one by one they succumbed. The blue of cobalt, however, proved indestructible and so, when the technical knowledge of the South met the traditions borrowed from the Chinese, there was born, in the little town of Delft in Holland, the blue enameled ware which has ever since been known by the name of its native place. As to the technical details of the production of Delft ware a great deal of information is available. The clay used contained a goodly proportion of lime and this served to hold the enamel in perfect union with the body. The decoration was painted in cobalt blue upon the unburned surface of the enamel. This was, in a measure, courting a difficulty but it is the glory of the craft that a difficulty is cheerfully accepted if in the overcoming there is found success. If the Delft potters had burned their enamel in order to make the painting easy, the world would never have enjoyed the tender tone of blue for which this pottery is famous. By painting the blue color over the powdery enamel, a more perfect union of enamel and color was accomplished than would have been possible by any other means. This fact alone is sufficient to account for the unsatisfactory nature of the modern, so-called, Delft. Difficulties have been avoided rather than met and the success of the early masters has eluded their recent followers. Much of the pottery made in France in the seventeenth century was inspired by the Italian renaissance. In fact the word faience is due to the avowed intention of the manufacturers of Nevers to copy the enameled pottery of Faenza. Almost the only novelty of the time was the inversion, by the Nevers potters, of the Delft idea. Instead of a white enamel with a blue decoration they used, in part, a blue ground with a decoration in white. It is not known that this variation found acceptance in any other place but in many localities, notably at Rouen, the manufacture of enameled wares was pursued with great success. The only real difference between the wares of Spain, Italy and France, lies in the decorative treatment. Sometimes the emphasis was laid upon lustres, sometimes on blue and white and again upon polychrome painting. In one place there was an extensive use made of pictorial treatment, in another all was conventional. The differences are interesting to a student or a collector but to the craftsman enameled pottery affords but one, though by no means an unimportant, means of expression. France, however, gave birth to two important and interesting departures from the beaten track; the so-called Henri deux ware, and the faience of Bernard Palissy. Important as these are to the ceramist, it is a remarkable fact that neither of them had any appreciable influence upon the art as a whole nor did they leave any descendants. A good deal of controversy has raged around the pottery commonly known as Henri II, some authorities claiming that it should be called Faience d'Oiron, and others assigning to it the name Saint Porchaire. It was, quite evidently, the production of an individual or group of individuals who had no connection with ordinary pottery manufacture, and the small quantity produced is evidence that it was made for personal pleasure. The name Henri II is undoubtedly satisfactory, for it was made in the reign of the second Henry and some pieces bear the monogram of the king. On the other hand H may be the initial of Helene d'Hengest, who occupied the chateau d'Oiron and who had in her employ one Bernard who filled the position of librarian. The style of the work seems to indicate a devotion to books, for the patterns are suggestive of book-binding tool work but were not produced in the same way. The ware was made of a natural cream-colored clay and the shapes were modeled with great skill. Upon the plain surface patterns were tooled or incised and the hollows thus formed were filled in with dark-colored clays. The whole was then covered with a clear lead glaze which afforded a finish very much like modern earthenware. The origin of this work is a matter of little more than academic interest but the technical details are of such importance as to be well worth a study. The ware is original and unique. No pottery either before or since has approached it in method, and the quality of most of the pieces is all that could be desired. Such was the elaboration of detail that no price could have been set upon the ware and it was evidently not made for sale. A distinct growth in style can be traced. The first pieces were somewhat archaic and even crude but as skill was acquired greater perfection was attained. As is too often the case, however, the skillful hand overreached itself and the later pieces are loaded with meretricious detail in many colors. There are only about fifty pieces known and these are equally divided between the museums of France and England. Bernard Palissy was a versatile genius but is here only considered as a potter. He states in his records that he was inspired by seeing an enameled cup. It was at one time supposed that this cup was of Italian maiolica but later authorities incline to the belief that it was a piece of Chinese porcelain which Palissy supposed to have been enameled. No white clay was known to him but enameled wares were quite accessible. It can scarcely be believed that maiolica was a novelty but it can easily be understood that a piece of white porcelain, viewed in the light of the contemporary knowledge of enamels, would appear of marvellous quality. Palissy essayed to imitate this wonder but attacked the problem from the standpoint of an opaque glaze. He spent fifteen years in experimenting but never realized his ideal. He did, however, produce a palette of marvellous colored enamels. He was a close student of nature and modeled all kinds of natural objects, glazing them in the proper hues. He also designed and made vases and service pieces, some with figure embossments. The story of his struggles is readily accessible to any who are interested. Palissy left little or no impression upon the ceramic art of his time but in recent years some work has been done in colored glazes fusible at a low temperature. This ware is sometimes sold under the name of maiolica but it is more nearly an imitation of Palissy. The main difference between the two types is that while the maiolica or tin-glazed pottery of Spain, Italy and France consisted for the most part of a white enameled surface upon which painting was applied, Palissy used little or no white enamel but decorated his wares with tinted glazes which themselves supplied the colors. In the low countries and the German states there was made the striking and original pottery known as _Grès de Flandres_. The clay was of the type commonly used for the manufacture of stone-ware and appears in three colors, brown, gray and cream. The ware was made on the wheel and embossments more or less elaborate were subsequently added. The unique feature consisted in the method of applying the glaze. This was simply common salt, thrown into the heated kiln and volatilized. The salt vapor bathed the glowing pottery and combined with its substance, thus producing the delightful orange-skin texture known as salt glaze. The knowledge of this method was conveyed to England in the seventeenth century and gained wide acceptance there. The English potters preferred to use clays which were almost white, and after glazing a decoration in brilliant colors was sometimes added. Naturalistic treatment was not attempted but conventionalized subjects were used with almost the effect of jewelry. The temperature at which this work can be produced varies with the clay. Many fusible clays will take a salt glaze but the beauty of the product depends to a large extent upon the purity of the body. This necessitates a hard fire, for white-burning clays always need a high temperature for vitrification. The early potteries of England were dependent largely upon clay effects. Some little enameled ware was made and is known as English Delft; but the bulk of the work was slip painted, incised, marbled or embossed. Each of these methods is capable of an intelligent application and all are within the reach of the artist potter. CHAPTER III: PORCELAIN The production of porcelain is the goal of the potter. The pure white of the clay and the possibility of unlimited fire treatment exert a profound influence upon the imagination while the difficulties of manipulation only serve to stimulate the energy of the enthusiast. For present purposes not much is to be learned from the soft porcelains of France nor from the bone china of England. German and French hard porcelain are but developments of the Chinese idea and therefore need not be studied apart from their prototype. The earliest date of Chinese porcelain is unknown. The records of the nation are very ancient but their meaning is often obscured by the fact that in the Chinese language the same word was used of old to denote both porcelain and earthenware. Specimens dating from only the tenth century A. D. look almost incredibly old. They are coarse and heavy in structure but are aglow with vibrant color. The finest porcelains date from the fourteenth and fifteenth centuries and these are the ideals towards which every modern potter looks. Broadly it may be stated that two methods prevailed. In the former the glaze itself was charged with color or the coloring matter was applied to the clay beneath the glaze. In the latter the porcelain was finished as to body and glaze and the decoration was applied at a subsequent and much lighter burn. The first named class is called single-colored porcelain; the second has several names such as the famille rose and famille verte as defined by Jacquemart. In the single-color class it is evident that the potters were not at all sure of their results. In many museums there are to be found examples of ox-blood red, more or less fine, and, with them, other pieces which were intended to be red but which failed in the fire. The wonder is, in these cases, that the pieces, even though failures, are beautiful. The knowledge required for the production of these wares is largely scientific; at the same time it is not to be believed that the Chinese had any special scientific training. They evidently traveled a long and tortuous path before the goal was reached, in fact, they often fell short of it altogether, but they had plenty of time and unlimited patience. The modern potter is, if less patient, more fortunate in that the course has been marked out with more or less accuracy and, if the landmarks of science be heeded, a certain degree of success may be attained. This single-color work is the true field of the ceramist. Anyone possessing the power of using a pencil, and with a large stock of patience, may produce over-glaze decoration, but to prepare glazes of many hues and to consign them unprotected to the fury of the furnace, requires skill, patience, courage and enthusiasm. During the last twenty years a new school has arisen which combines in a measure the advantages of the two Chinese methods. Colors are prepared from refractory materials and upon clay or soft burned biscuit ware, scenes, in more or less conventional form, are painted, or else a design purely conventional in character is applied by the artist. The ware is then glazed and subjected to the severe fire which all porcelain undergoes. The result is that the porcelain and the painting are united in a sense that can never be the case with over-glaze treatment. The colors become part of a purely ceramic unit; the spirit of the artist is fixed by the fire. To this class belong the porcelain of Copenhagen and the recent product of Sevres. These, of course, represent the result of much arduous training and many tedious experiments. Both the training and the experiments are necessary to some extent for every worker, not only because pottery clays vary much in composition, but because individuality can only be obtained by the preparation, in the laboratory, of the desired compounds. The Chinese, doubtless, stumbled upon many of their successes by accident, helped by the fact that the character of the fire employed influenced many of their colors. This will be explained in a later chapter. They were, however, quick to seize upon that which was good. Many fanciful names were given to the rarest colors, such as "the violet of wild apples," "liquid dawn" and "the red of the bean blossom." This idea has been carried further in France by the invention of such names as "_Sang-de-boeuf_," "_Sang-de-poulet_," "_clair-de-lune_," etc., and pursued in this country in "Peach blow." In the over-glaze treatment, the type named "famille verte" is characterized by a clear green glaze or enamel over a design in black. The whole is painted over the porcelain glaze and the green enamel is so soft that it is often decomposed on the surface. When a broad black mass is covered with green the decomposition gives rise to prismatic colors and occasions the term "raven's wing black." Some of this ware has also been gilt but the gold lines have disappeared and can only be located by the slight dullness of the enamel where they once were. Well known to collectors also are the rose-back plates. These belong to the "famille rose" in which the characteristic note is a delicate rose pink. This color is prepared from gold and when it is placed upon the back of an egg-shell plate a tender rosy transparency is imparted to the piece. One of the best known of the single colors is the pale sea green named celadon by the French. This color in China was called "the sky after rain" and was considered both rare and valuable. The porcelain of Copenhagen is the product of scientific skill and artistic taste. In the studios attached to the Royal Manufactory there has grown up a tradition of work and criticism which is fostered by ladies of birth and position. Many of these paint upon the porcelain themselves and so constitute a school which has become world famous. Natural objects are, for the most part, chosen and, as the palette of colors is, owing to the intense fire, quite limited and low in key, a tone of quiet atmosphere pervades the painting. This is accentuated by the use of the air-brush to distribute a ground color upon the ware in graduated strength. At the National Manufactory of Sevres there has been some attempt to follow the Copenhagen method but to a greater extent the work is along the lines of conventionalized form. In this treatment the French artists excel, being wonderfully accurate--almost too accurate--in their lines and spacing. Several individual workers in France have also pursued this plan, designing and executing the pieces which have made the French artist-potters famous. In the porcelains of Berlin the quality lies largely in the complete mastery of technical details. The work is, as would be expected, German in style, but the paste is pure and the colors are well prepared. From this brief review it will be seen that the interest in the manufacture of porcelain lies not so much in variety as in the value of individual results. In the pottery described in the previous chapter a great many different clays were used and each one proved suggestive to the potter. In porcelain, on the other hand, the body clay is almost identical wherever prepared, the requirement of a white translucent paste being paramount. CHAPTER IV: THE NATURE AND PROPERTIES OF CLAY Clay differs from earth or soil in that it possesses certain characteristics which these do not possess. Its distribution is very wide but for the most part it lies concealed from view. In certain parts of the country it is so abundant that it breaks through the surface or is exposed as an outcrop but usually it is covered by the soil which supports vegetation. Unless the subsoil consists of sand it is easy to expose a clay by plowing or digging with a spade. It usually appears as a greenish or bluish substance of close and uniform structure. The texture is sometimes smooth but more often numerous small stones are found imbedded in the mass. Such clays as are commonly found can be used for the manufacture of some kind of pottery but in the great majority of cases the ware will be red when fired because the clay contains a proportion of oxide of iron. A pure clay does not contain this and therefore becomes white or nearly white in the kiln. Pure clay, known as clay base or clay substance forms a part of all natural clays though sometimes only a small part. It consists of silica, alumina and water in a state of combination and is thus known as a hydrous aluminium silicate. While this substance is very common as an ingredient of ordinary clay, it is rarely found alone or uncontaminated. Commercial or workable clays may be said to consist of clay base and sand, with or without other impurities such as lime and oxide of iron. For working purposes it may be granted that the potter has to deal with a mixture of clay and sand. But sand is not a definite expression. It may vary both physically and chemically within wide limits. The physical nature has to do with condition, the chemical with composition. Thus a sand may be almost as coarse as gravel or as fine as the clay itself. It may be a pure quartz sand or it may be a crushed rock of almost any composition. The former is known as quartz, the latter as feldspar or feldspathic sand because it approaches in composition the group of minerals known as feldspars. Each of these ingredients, clay, quartz and feldspar, has an important part to play in the transformation of clay into pottery. Few of the clays used in making white pottery possess these ingredients in the correct proportions so that it becomes necessary to make a mixture in which the necessary proportions will be found. For successful pottery making three properties are demanded in a clay. First, plasticity. Without this, clay could not be shaped at all. It constitutes the obedience of a clay to the forming influence whether hand or mold. The necessity for this quality may be illustrated by the proverb "Making ropes of sand" as an example of the impossible. Sand, possessing no plasticity, cannot be shaped or made to hold together. The second property is porosity. A clay which exhibits a high degree of plasticity can be easily shaped but it cannot be safely dried. The water of plasticity cannot escape and therefore the clay warps and cracks. The function of porosity is to prevent this. A porous clay permits the water to escape freely and the clay can be dried without damage. This condition is produced by the admixture of sand or by the presence of sand in a natural clay. A coarse sand is more effective than a fine sand but a sand that is too coarse will interfere with delicate working while a sand that is too fine approximates the action of the clay itself and produces a substance which is dense rather than porous. Porosity is therefore the reverse of plasticity and these two properties must be adjusted so as to balance each other. The third necessary property is commonly known as vitrification but could be better named "densification" because complete vitrification is not attained in ordinary clay wares. This property may be defined as that which causes a clay to yield to the action of a high temperature so that the result is a ware, more or less dense, which is hard, durable and sonorous. With this there must be coupled a certain amount of resistance to heat treatment so that the pottery does not fuse or collapse during the firing. Here also is found the need for adjustment. The clay must yield to the fire but not completely. It must resist but not entirely. Plasticity is due to the clay base. Not only to its quantity but to its quality also. Some forms of clay in which clay base predominates are not plastic because the clay base itself is coarse grained. Other forms with less clay base present are plastic because this ingredient is fine grained and tough. Pure clay base is also highly resistant to fire and therefore contributes to the refractoriness of the mass. Porosity is caused by the sand in the clay. Any kind of sand will produce porosity but the effect differs with the condition of the sand. Coarse sand is more effective than fine sand. More sand will, of course, cause greater porosity. Vitrification or densification is due to the feldspar or fusible sand. This also varies with the condition. A fine-grained feldspar will produce vitrification more easily than the same amount of coarse feldspar. Certain substances are available for use in pottery mixtures, which possess one or other of the necessary properties in high degree so that they will impart these properties to a mass to which they are added. Kaolin or china clay is usually fine, white, and refractory. Some kaolins are rather plastic but most of them are "short" in working and rather tender. For the production of a white ware kaolin is indispensable. No other ingredient will afford the pure white color which is sought after in porcelain and china. Ball clay is very plastic, easily vitrified, but is not white. The color varies from a cream to a gray. The use of a ball clay is therefore limited in white wares because it will spoil the color. For wares in which a light cream color is not objectionable ball clays are valuable and almost indispensable. Stoneware clay is usually a rather plastic clay which contains a good deal of sand, hence stoneware clays can be used for certain classes of ware without admixture. A rather high temperature is required for most of these clays, though occasionally one can be found which will become dense at the fire of a studio kiln. The clays sold by the Enfield Pottery Company and by the Western Stoneware Company are of this type. Ground flint is a necessary ingredient in almost all pottery. It aids in the porosity of the clay and enables the mixture to be adjusted to fit a special glaze. Ground feldspar is also necessary. Like flint it aids in the porosity of the unburned clay but unlike flint it produces density in the firing. By a proper adjustment of these ingredients a clay can be composed which will meet the special requirements of the worker. In order to ascertain the properties of any given clay certain simple tests may be made and every clay-worker should know how to do this because one cannot be too well informed as to the materials to be used. First, water of plasticity. A certain portion of the clay, dried and powdered, is weighed out. It is convenient to weigh in grams and to measure in cubic centimeters because in this way calculation is easy. The scales and weights are described in the chapter on glazes. For measuring the water a glass vessel called a graduate is used. One holding a hundred cubic centimeters and graduated in centimeters and tenths can be obtained from a dealer in chemical supplies. One hundred grams of clay is weighed out and transferred to a glass slab. The graduate is filled with water to the one hundred mark. Some of this water is then poured on to the clay, adding little by little as needed until the whole can be worked into a stiff mass of the proper plasticity. The quantity of water used is then carefully noted by observing how much is left in the graduate. Suppose, for instance, 70 cubic centimeters are found remaining, the hundred grams of clay has absorbed thirty c.c. of water and as one c.c. of water weighs one gram the clay has taken just 30 per cent. This amount is important because it is one of the best indications of plasticity. A very plastic clay may need 40 per cent, a non-plastic clay may be satisfied with 25 per cent. Second, shrinkage. The mass of plastic clay is now transferred to a plaster bat and rolled or pressed out into a smooth slab about 12 centimeters long. Here again the centimeter is used in preference to the inch as being more easily calculated. A faint line is ruled on the clay slab and two fine scratches are marked exactly ten centimeters apart. The edges are trimmed and the excess clay made up into three or four small pieces which are to be fired in different parts of the kiln as tests for density. When the clay slab is dry the distance between the marks is measured and noted. The ten centimeters being divided into one hundred millimeters, each millimeter of shrinkage means one per cent. After firing, a second measurement is made and the differences are noted as dry shrinkage and fire shrinkage respectively. Third, firing. The slab with the measurement upon it is set in the kiln in the place where the clay wares are to receive the first or biscuit fire and the small pieces are arranged in different places so as to secure as many different conditions as possible. The position of each should be carefully recorded. After firing, the marks on the slab are measured as already described and note is taken of any warping of the piece. The color is also recorded. The small pieces should be tested for porosity or absorption of water but this is rather a delicate operation and needs a particularly sensitive balance. Generally it will suffice to use a wet sponge or to dip each piece into water, removing it quickly and noting carefully the rate of speed at which the water is absorbed. If the water should be scarcely absorbed at all a line of ink may be drawn upon the pottery with a pen, the piece being perfectly dry. In a fully vitrified ware the ink can be washed off, leaving scarcely a mark but the test is quite sensitive and with a little practice will afford an excellent means of comparing the density of different clays or of the same clay at different temperatures. Fourth, glazing. It is well to have ready a small supply of a standard clear glaze. Each of the test pieces should be covered with this in a rather thin coat and then they should all be fired again, this time close together so that they will receive the same heat treatment. This will enable one to determine what degree of fire for the clay will best suit the glaze. CHAPTER V: THE PREPARATION OF THE CLAY A clay having been selected in accordance with the tests described, it becomes necessary to prepare it for use. A fairly large supply should be obtained and stored in a dry place. Most natural clays need some kind of cleansing for there are almost always foreign substances present. This cleansing is accomplished by reducing the clay to the fluid known as slip. The necessary appliances for making slip are as follows: A large sieve of quarter-inch mesh. A small wire sieve of about 14 meshes to the inch. A large barrel. Two galvanized pails. The clay is, after drying, powdered and sifted through the large sieve. One of the pails is half filled with clean water and the clay, handful by handful, is sprinkled into it. The clay rapidly absorbs the water and sinks to the bottom. The addition of clay is continued until a small mound rises through the water, when the whole is left to soak for an hour. The bared arm is then plunged into the pail and the mass stirred vigorously. A stick or paddle will serve, of course, but the potter learns a great deal by the feel of the clay and therefore the hand is best. It is said that he is a poor sailor who will not dip his hands in the tar bucket and in like manner, he is a poor potter who fears the slip tub. This stirring will tell a good deal about the probable working of the clay. It may be stony or sandy or greasy. The large stones and roots will have been removed by the sieve but now, after thorough mixing, the slip is poured through the small sieve into the barrel. Both pails may be kept going at once, one being filled while the other is soaking and so on until the barrel is full or, at least, a good quantity of slip has been prepared. If the clay prove very sandy it should be washed. The mixture in the pail having been well stirred is allowed to stand for a definite time, say one minute. The slip is then poured into the second pail and it will be found that a quantity of sand has settled. This is thrown away and the slip in the second pail is examined. If enough sand has been removed, the slip may be poured into the barrel, using the fine sieve as already described. If still sandy the process should be repeated, the settling being for two minutes. Experience is the best guide in this operation but all the sand should not be removed. When the barrel is full of slip it is allowed to stand over night when some inches of clear water will be found at the top. This is removed with a siphon which may be made of a piece of lead or rubber pipe. The removal of the water results in the thickening of the slip and the contents of the barrel should be thoroughly stirred with a long wooden paddle to insure a uniform consistency. If the slip is found to be still thin another settling and removal of the water will thicken it. The slip thus prepared will keep indefinitely, provided that it is not allowed to become dry by evaporation. It improves greatly with age. This is the material which is used for casting as will be described later but for plastic work it must be still further thickened. A shallow box may be procured and made water-tight and the slip, when poured into it, will thicken much more rapidly than in the barrel, but it is better to have some shallow plaster dishes as the plaster itself absorbs the water and thickens the clay. Instructions for making these dishes appear in the chapter on plaster. These directions will suffice for the preparation of a natural clay but it is sometimes desired to prepare a white body either of earthenware or porcelain. These bodies do not exist in nature and therefore a mixture must be made. The ingredients are kaolin or white porcelain clay, ball clay or plastic potters' clay, ground quartz or flint, and ground feldspar.[B] [B] Georgia Kaolin and Tennessee Ball Clay may be procured from the John H. Sant and Sons Company, East Liverpool, Ohio, and flint and feldspar from the Golding Sons' Company, Trenton, N. J., or the Eureka Flint and Spar Company, Trenton, N. J., in quantities of not less than one barrel or sack. A suitable mixture for earthenware is-- Georgia Clay[C] 20 parts by weight Tennessee Ball Clay 30 " " " Flint 35 " " " Feldspar 15 " " " --- 100 and for porcelain-- Georgia Clay 45 parts by weight Flint 35 " " " Feldspar 20 " " " --- 100 [C] If English china clay can be procured it will make a whiter ware than Georgia clay. The earthenware will be creamy in color and porous at an ordinary fire. The porcelain will need a hard fire and will be white and translucent. It is, however, non-plastic and hard to work. The preparation of these mixtures of course necessitates a pair of scales but otherwise the treatment of the mix is the same as that of natural clay. Washing is not necessary but the clay must be powdered, mixed with the flint and spar, and sprinkled into water as already described. In place of the wire sieve, however, a silk lawn of 120 meshes to the inch should be used. The lawn is simply a fine sieve and is named because of the material (also called bolting cloth), with which it is covered. Have a carpenter make a box without a bottom. Cypress or oak should be used and this should be a full half inch thick. Four strips of the same thickness are also to be provided. The box may be of any convenient size; eight inches square and four inches deep is about right. The sides should be fastened together with brass screws to avoid rust and a piece of lawn is strained tightly across the bottom and secured with copper or brass tacks. A strip of coarse muslin folded and laid along the edges will help to prevent the lawn from tearing, the tacks being, of course, driven through both muslin and lawn. Then the four wooden strips are set upon the muslin and secured with brass screws. The completed lawn is then a tray of which the bottom is formed of lawn. The strips of wood beneath serve to protect the lawn when placed on a table as well as to assist in holding it firmly.[D] [D] Silk lawn of any desired mesh may be purchased by the yard from A. Sartorius & Company, 57 Murray Street, New York City; or brass sieves ready for use from the W. S. Tyler Company, Cleveland, O. For storing clay in the plastic state there is nothing better than stoneware jars. These may be had of any size and a tinman should make close-fitting covers. Earthenware covers do not fit tight and are always getting broken. A little water is poured into each jar and a support provided for the clay so that it does not rest in contact with the water. Under any conditions clay will slowly harden so that not too large a stock should be kept. Slip, on the other hand, keeps well so long as some water is always on the top and it is not a long process to stiffen it into clay. CHAPTER VI: MOLD-MAKING AND PLASTER Plaster is almost a necessity to the potter and therefore something should be learned about it. Even if one does not use molds there are numberless purposes for which plaster is convenient. For stiffening slip into clay, and for absorbing water from glazes, shallow dishes of plaster are used, and for holding work either in making or drying, plaster bats or round slabs are always in demand. It is best to purchase the finest quality of potters' plaster by the barrel.[E] It will keep indefinitely if stored in a dry place. The necessary appliances are: One or two large jugs for mixing, or a metal can with a spout. A metal spider or frying pan. Six feet of rubber machine belting, six inches wide, or similar strips cut from linoleum or enameled cloth. Two or three thin pieces of steel of various degrees of flexibility (scrapers). Handy knives, called vegetable knives. A small painter's brush. Two or three fine sponges. [E] Calvin Tomkins, 30 Church Street, New York City. To begin with, a size of soft soap and water is prepared. Put a quart of water into a kettle and add a piece of soap the size of an egg.[F] Simmer for an hour or until the soap is entirely dissolved and then set aside to cool. When cold the size should be of the consistency of maple syrup. This size is used whenever plaster is to be kept from sticking to a form or surface, and it has also the merit of causing clay to stick to plaster. For example, if a mold is to be taken from a clay model no size should be used, but if a plaster form is used as a foundation for clay ornament it should be well sized first. The size is laid on with a brush and wiped off with a sponge. Another sponge is then used with clean water and the sized surface is washed, all superfluous water being removed. Size is then applied a second time and washed off as before. A third application is sometimes necessary, or until the sized surface rejects water like grease does. On the last sizing, water is not applied, but the surface is polished with the sponge containing size. If the surface to be prepared be of wood or metal a single coat of size will often suffice, but if it be of plaster three or four applications are often necessary. [F] Any good laundry soap will serve, but it should be sliced thin. The first lesson may well be the manufacture of a plaster bat. The frying pan is first sized and set upon a level table. Let us suppose that a quart of water will fill it to about an inch in depth. This amount of water is put into a jug and two pounds and three-quarters of dry plaster is weighed out and allowed to trickle through the fingers into the water. This proportion has been found to be best for ordinary mixings. A smaller quantity of plaster to the quart of water will result in a very soft bat; a larger quantity will be proportionately harder. After the plaster has soaked up all the water it will take, that is in about two minutes' time, the hand is plunged in and the whole stirred to a smooth cream. All lumps must be broken up and the air bubbles removed as far as possible. Continue stirring gently and presently the mixture will be felt to grow thicker. The psychological moment arrives when the plaster forms upon the hand a white coating which cannot be shaken off. The creamy liquid is then poured into the frying pan which is gently shaken to level the surface. If the plaster has been poured at the right moment it will set smoothly with a mat surface like sugar icing. If poured too late it will be stiff and difficult to level, and if poured too soon it will curdle on the surface and water will be seen above the plaster. A little practice will show the right moment. The jug should be washed out immediately while the plaster is soft. In the place used for plaster work a tub should be provided in which all vessels and tools can be washed, for, if allowed to flow down the waste pipe of a sink, the plaster will speedily choke the outflow. After standing for some ten minutes, more or less, the bat in the frying pan will grow warm. This is the sign of a combination between the plaster and the water and shows the completion of the setting. The pan is now taken by the handle and, holding it upside down, the edge is rapped smartly on a brick or stone. This will cause the contents to fall out and there is a smooth disc which is one of the most useful of appliances. The edge will need to be scraped and the bat can be set aside until needed. It will be good practice to make a half dozen of these. This process of mixing and pouring plaster is the same for all operations and the instructions will not be repeated, but when the student is told to "pour plaster" it will be presumed that this experiment has already been made. [Illustration: Fig. 1. _A_, table. _B_, clay mound. _C_, plaster. _D_, rubber belt.] The next step is the making of a plaster bowl or dish for the purpose of drying out slip or glaze. A convenient size should be determined upon as it is best to have all the dishes the same. Upon any flat, smooth surface a mound of clay is reared which shall be the size and depth of the inside of the proposed dish. About twelve inches in diameter and three inches deep is a good size, though fourteen inches is not too large for the former dimension. This mound should be made as nearly circular as possible and the clay finished as smoothly as may be. The rubber belt is then set around the mound in the form of a hoop leaving a space of two inches between the clay mound and the rubber hoop. The rubber is fastened either by tying with string or by binding the overlapping ends with clothes pins. A roll of soft clay is laid down where the belt joins the table and pressed down outside to prevent leakage. Enough plaster to fill the space within the belt is now mixed and poured, covering the clay mound to a depth of at least one inch. When the plaster has set the rubber is detached, the whole turned over and the clay dug out. We have now a circular plaster dish three inches deep but we have only one. The trouble of rebuilding the clay is unnecessary a second time because a "case" or reverse can be made from which as many dishes as may be necessary can be formed. [Illustration: Fig. 2. _C_, plaster dish. _D_, rubber belt. _E_, plaster case or reverse.] [Illustration: Fig. 3. Plaster case, with rubber belt, arranged for pouring.] The dish is carefully smoothed and trimmed. The sharp edge is removed and the inside is dressed with fine sandpaper to a perfectly smooth surface. Size is now applied to the inside and upper edge until a bright slippery surface is obtained. The rubber belt is now bound closely around the dish and plaster is poured to a depth of about one and one-half inches on the edge. This, of course, makes a depth of four and one-half inches in the center. When this new plaster has set in turn the rubber is removed and the two castings can be easily separated by inserting a knife at the junction. The knife should be gently driven in with a hammer. Obviously it is now possible to make a number of dishes from the reverse thus obtained, by simply binding the rubber belt around each time and pouring plaster as at first. The original mold having been sized is no longer absorbent but must be kept in case additional reverses are needed. The molds or dishes must be thoroughly dried out before being used. The molding of a vase form is more elaborate but not really difficult. Even if one does not intend to produce pottery by molding there is always an advantage in having a number of simple forms upon which to make experiments. The vase to be molded is first drawn to exact size upon paper and a plaster model is turned on a lathe. This can be done equally well on the potters' wheel and the method is as follows: A plaster bat is saturated with water and set upon the wheel so as to run true when the wheel is revolved, and is cemented to the wheel head by a little slip. A few deep scratches are made on the face of the bat and a cylinder, either of the rubber belt or of stiff paper, is rolled up and set on end in the center of the bat. The size of the cylinder should be a little larger every way than the proposed vase. Plaster is now mixed and poured to fill the cylinder. It will adhere to the bat below by reason of the scratches. When the plaster has set, the cylinder is unfastened and removed and the turning may begin. To turn plaster well involves a good deal of practice but it is better to spoil three or four plaster cores in the learning than to spend a long time on one for fear of damaging it. [Illustration: Fig. 4. Turning tools for plaster.] [Illustration: Fig. 5. Position of tool in turning. _A_, correct. _B_ and _C_, incorrect.] The board support and turning stick described on page 100 are used in turning plaster as well as clay. The turning stick is held in the left hand and the point is pressed into the board. All this is, of course, made ready before the plaster is poured. The turning tools are here illustrated. They are not sold in the stores but can be made by any machinist. The head or cutting blade consists of a flat piece of steel through the center of which is a shaft or pin which is driven into a handle. The head may be of any shape but the triangle and the circle will meet every need. The tool is held in right hand and braced against the turning stick, the stick and tool being moved together by raising or lowering the left hand which holds the butt of the stick. While the plaster is still soft the round tool is used and the rough form is rapidly turned. Then as the setting of the plaster proceeds and it is found to grow harder, the triangle tool should be used and the shape gradually wrought out with the point. Finally by using the circle tool for concave lines and an edge of the triangle tool for convex lines the form is perfected. The surface is to be finished and the tool marks removed by using, free hand, a flexible scraper which is bent by the fingers and thumb to fit the lines of the form, and a final smoothing is given by fine sandpaper, the wheel being revolved all the time. At the top of the form a small cylindrical piece is left, called the "spare" which represents the thickness of the mold substance, and for the bottom a small piece is turned in the shape of a truncated cone. The small end of this should be the same diameter as the base of the vase. These are shown in the illustration (Fig. 6). [Illustration: Fig. 6. Vase with foot piece and template. _A_, vase. _B_, spare. _C_, foot piece. _D D_, templates. _N N N N_, natches.] It will be obvious that in the directions given above the base of the vase is not finished off and therefore the form must be cut off from the bat, either by a knife or saw, and the base is then finished by hand, or by setting the form upside down in a clay cradle--called a "chum"--and turning the base true. The form is now ready for molding. [Illustration: Fig. 7. End plates for mold. _E_, upper plate. _E'_, lower plate. _N N_, natches.] The plaster vase is laid upon its side on a piece of soft clay and a thin bat or plaster slab is cut to fit the outline. This template should fit with reasonable accuracy but need not be absolutely exact. A pair of these will be required, one to fit each side of the form. These slabs or sheets of plaster are always useful and if a sheet of glass is kept handy any excess of plaster left from a mixing may be poured on to it. This upon setting is easily detached and will present a smooth face where it has rested on the glass. The pair of templates must include, in their outline, both the spare and the foot piece but should not extend beyond either of these. The outside diameter of the mold is now to be determined and the templates cut to this dimension so that the two together, with the vase between them, constitute a longitudinal section of the mold. The vase must now be divided accurately into two halves by a line running from top to bottom. There are several ways of doing this. While the form is still on the bat a diameter of the bat may be drawn and a perpendicular erected from each end of this diameter. These perpendicular lines will, of course, mark the center of the vase on each side; or after the vase has been cut off another method is possible. With a pair of dividers find the center of both the top and the bottom of the vase. Mark each with a small hole or the point of a pencil. Now lay the vase on its side on the clay cradle upon a glass sheet or other level surface and raise or depress one end until the two centers are exactly the same height from the glass. Take this height in the dividers and, sliding one of the compass legs along the glass, gently scratch the plaster vase with the other or upper point. If the two centers have been accurately adjusted this scratch line will be the exact center of the form. Some soft clay is now built up on each side of the vase and the templates are pressed down upon it, one on each side until the upper face of each corresponds with the scratched line. The vase is now seen to be buried as to one half in a plaster surface, and plaster poured on this will give a half mold. There is yet, however, nothing to confine the plaster and it would flow away as fast as poured. Two end plates are necessary and these must rise in a half circle above the bed formed by the templates. The part below may be of any shape but must be high enough to cause the diameter of the half circle to coincide with the plane of the templates. Two pieces of cardboard, wood, or rubber belt are now bound to the sides, the apertures at the top and bottom, caused by the curve of the end plates, are stopped with clay and the whole presents the appearance of a vase, only half of which is visible, lying in a shallow trough. All the fitting should be carefully done but the tying up is not yet. The whole is now taken apart and well sized. Vase, foot piece, templates and end pieces are all to be sized thoroughly in the manner described. They are then put together again and bound around with twine. It is necessary now to make provision for the proper fitting of the halves of the mold. This is done by providing knobs and hollows which fit together. These are technically known as "natches" and will be referred to as such. Take two pieces of moderately stiff clay each about the size of a cherry. Roll them into neat balls and cut them in two with a thin knife. Lay each of the halves, flat side down, upon the templates, two on each, placing them in pairs opposite to each other. Affix two or more of these on the inner face of the bottom end plate. Now mix and pour the plaster. This should be poured to the height of the top of the end plates and, after pouring, shake this well down by dipping the fingers into it, so that no bubbles may cling to the surfaces below. As soon as the plaster has become firm but while it is still soft remove the string and the side boards, pull off the pieces of clay and with a straight, thin piece of wood scrape off the surplus of plaster by following the line of the end plates and thus making a half cylinder. As soon as the plaster has become warm the whole may be turned over and the templates and end plates removed. The four half spheres of clay will be found embedded in the face of the plaster and these, being removed, will leave four hemispherical depressions. The vase can now be gently detached from its bed and the first half of the mold is completed. A little dressing will be necessary. All overhanging edges and rough places should be finished off and the hollow natches smoothed with a piece of muslin on the end of a finger. The second half is simple. Replace the vase in the half mold, set the foot piece in its place, replace the end plates with the diameter on the line as before but with the semi-circular edges upward, and set two or three clay natches on the bottom one. Size, bind up, pour and scrape off as before, thus completing the two halves of the mold in cylindrical form. It only now remains to make the bottom for, at present, the mold is open at both ends. The two halves with the vase inside are bound very tightly together with twine and set on the table bottom upwards. The clay natches in the bottom are taken out and the hollows smoothed. The foot piece is taken out and the rough places dressed. The bottom end of the vase is now visible and this, together with the end of the mold, is sized. A strip of stout paper is bound around the mold, projecting about an inch above the end and plaster is poured to fill it. When this is set the paper is peeled off and the edges of the mold are dressed smooth. The bottom may now be detached by inserting a thin knife at the junction, the mold opened and the form taken out. The mold is now in three parts which may be put together at will and used for casting the vase in clay. CHAPTER VII: CASES AND WORKING MOLDS The mold described in the previous chapter is called, technically, a "block mold" and is not, as a rule, used for making the clay ware. The reason for this is that molds will wear out more or less rapidly and to repeat the process of making new ones from the original form would be tedious and expensive. From the block mold a reverse is made, called a "case," and from this, in turn, working molds are made in any required number. While it is possible to use the block mold as a working mold, and, if only a few pieces are required this is quite sufficient, yet, as it is often necessary to have a number of molds, the student should understand how to make a case. A case may be defined as a mold from which a mold is made. If one can imagine the visible half of the vase form as it appears in making the mold, with the templates and ends cemented into one piece, one has a conception of one half of a case. The problem is to make this with permanent but movable ends so as to have a convenient form from which half molds may be easily made. [Illustration: Fig. 8. Offset plates. _F_, top plate, front view. _F'_, side view. _G G'_, bottom plate.] [Illustration: Fig. 9. Sectional view of mold ready for casing. _A_, mold. _B B_, offset plates. _C C_, end plates. _N N_, natches.] The ends are joined to the body by means of offsets and the first step is the construction of these. One half of the block is taken and laid upon its back, being supported by clay so that the face is level and steady. An offset plate is now cut to fit each end. To make these a piece of plaster is selected or made which is true and smooth on both sides. The plates are cut of the same width as the mold and are beveled at the upper edge so as to rise slightly from the mold face. The curve at the end of the mold is cut out to fit and beveled in like manner. Then two end plates are fitted. These should be about two inches higher than the offset plates and are square at the top. Upon each of these two or three clay natches are set, being placed low down near the face of the mold. The mold and plates are well sized and bound together with side walls just as in the making of the mold. Plaster is poured to a height sufficient to well cover the natches and left to set hard. No shaping is necessary. When well set the end plates and offset plates are removed but the vase mold and the case are left attached together. The other half of the mold is prepared and run in the same way, the same offset plates and end plates being used with such slight refitting as may be necessary. The work is now examined and all rough places and scraps of adhering plaster are removed. The two halves of the case, the half molds being still attached, are set up on end, back to back, being separated by a thin piece of plaster or a strip of cardboard which should extend two inches above the top. The top ends are now sized, the natch holes having been smoothed off, a band of paper is tied around and plaster poured on top to a depth of about one inch. When set the whole is turned over and the operation is repeated on the other end. After the final setting the ends are easily removed and by the insertion of a thin knife driven by a light blow, the molds and case are separated. Each half case is now laid on its back and the proper ends are fitted in place. It only now needs the usual side walls to be tied on and molds can be made with ease just as the original block mold was made. [Illustration: Fig. 10. Mold and case in position. The top ends are lifted to show fitting. The bottom ends are not shown.] It now remains to make a case of the bottom mold. The bottom piece of the block mold is taken and sized and with a strip of paper bound around it, plaster is poured. The two are detached when set and the case is finished. It consists of seven pieces; three are used in each half and one for the bottom. [Illustration: Fig. 11. Block of plaster with face of plate turned. _B_, height of plaster to be poured. _C_, rubber belt.] Thus equipped it is possible to make any number of working molds and if the case should wear out or be damaged, a new one can always be made from the block mold. The block mold itself, having been sized, is no longer absorbent and cannot be used for making vases. The working molds should be thoroughly dried before using and they will last longer. Flat ware, such as plates and saucers, is made on, not in, a mold. The diameter of the plate having been decided upon, a block of plaster three inches wider is run. This is placed on the center of the wheel or jigger and in it the face of the plate is turned. This must be sunk below the level of the block and when finished, must appear as though the plate itself were embedded in the plaster. One half of the thickness of the edge is shown in such a way that there is no under cutting. Just outside of this edge the plaster is turned so as to slope gently up to the level of the block. Without removing the block from the wheel the face of the plate is well sized, a band of belting is arranged, of the same diameter as the edge of the slope and plaster is poured to a depth of three inches. Out of this the back of the mold is turned as shown in the illustration (Fig. 12). [Illustration: Fig. 12. _A_, block of plaster. _B_, mold poured on face of plate and turned.] The top of this as it lies upside down is shaped with a straight, almost upright slope which enables the mold to be set securely in the wheel head. Around the exposed edge of the original block, three or four natches are now bored or cut. They should be placed at irregular distances so that there will be no doubt as to the putting together of the sides of the case. If two circular pieces of plaster have to be set together and held by natches there should always be either this irregular spacing or some distinctive mark, because if this be not provided for, two or three trials will always be made before the correct fitting is found and these trials wear out the natches very quickly. [Illustration: Fig. 13. _A_, bottom of case. _B_, Cavity for pouring molds. _C_, top of case.] The back of the plate mold and the edges of the block are now sized and plaster is run to the level of the highest part of the mold but no higher (Fig. 13). When this is set, the two halves of the case can be separated and the mold taken out. Now when the halves of the case are fitted together there will be a cavity the exact size of the mold. This can be filled again and again with plaster, a new mold being formed each time. [Illustration: Fig. 14. Iron prong to fit wheel head.] [Illustration: Fig. 15. _A_, plaster, with prong inserted. _B_, rubber belt.] In order to use these molds a special head must be provided for the wheel. The regular head of the wheel should be detachable and in its place an iron frame called a prong is fitted. This consists of a collar either with a hollow cone or a screw to fit the shaft of the wheel, and from this radiate four short arms. In order to use this a circular block of plaster some two or three inches thick is poured on a table or slab and just as this is setting, the prong, upside down, is pressed into it just below the surface and held there until the plaster is hard enough to support the weight of the iron. When hard, the whole is lifted and the prong with the plaster attached is set in position on the wheel. This now forms a rough plaster head and it must be turned true. In this head a circular depression is to be turned which will exactly fit the back of the plate molds. If the recess should wear larger as it will if much used, a new head can easily be run. The same principle can be applied to the making of molds for saucers. [Illustration: Fig. 16. Wheel head with plate mold. The tool used is shown in dotted outline.] Cups and bowls are molded from the outside. A block of plaster about one inch thicker than the height of the proposed cup is taken and centered upon the wheel. Out of this the piece is to be turned, upside down, leaving a ledge or platform, the outside diameter of which is the size of the mold. The rubber belt is tied around this and the mold poured. If for casting this will suffice, but if it is intended to make the cups upon the wheel the outside of the mold must be turned to fit a wheel-head which is hollowed to receive it. The making of the cups is described in Chapter XI. A bowl is simply an enlarged cup. CHAPTER VIII: BUILDING BY HAND The production of pottery by hand is a form of modeling but with the important difference that while pieces modeled by art-school methods are not intended to be preserved in the clay itself, built pieces are destined for the fire. It is therefore necessary not only that a special clay be used but that the work be such as will hold under the strain of the burn. The composition of the clay has been dealt with in another chapter and it is presumed that the worker has decided upon the proper mix or has procured a suitable clay. There are two possible treatments of built pottery; the work may be finished by fingers and tools only or it may be placed upon the wheel and turned to a true surface. In the latter case the result is much the same as if the piece were thrown on the wheel as will be described. The principal point of difference is that while building needs less practice than throwing, turning a built piece is much more difficult and tedious than turning a thrown one. It is almost impossible to build with sufficient accuracy for the work to run true, and a great deal of time is consumed in filling hollows and removing lumps. These do not appear obtrusive when the work is held in the hand, but if it be revolved upon a fixed center every slight irregularity appears to be accentuated. On the other hand the charm of built ware lies in the subtle plastic quality which belongs to no other material or method. For very large pieces such as tree pots the combination method is useful but these should be built on the wheel itself and kept true as the work proceeds. Then a slight turning at the finish, when the clay is leather hard, will produce a satisfactory result. The clay for building should be rather soft as it is apt to dry quickly on handling. The work may be done either with coils or pieces. A plaster bat should be made with a low dome in the center. This bat may either fit the wheel or not, depending upon the plan adopted. The dome is to raise up the bottom of the vase and form a foot. The table may be covered with a piece of oil cloth or may be kept slightly damp. The first attempt should be to build a cylinder as this form is easy to construct and to keep true, so that the attention may be devoted to the manipulation of the clay. It is first necessary to roll out the clay into cords which should be a little thicker than the proposed walls are to be. These cords should be as uniform as possible and should be rolled quickly to avoid undue hardening. It is best to roll them as required. The domed bat is made quite damp and upon it should be marked the diameter of the cylinder to be built. A roll of clay is taken, one end laid in the center of the bat and the rest is coiled around it in a spiral line. When the disc so formed has reached the proper size, the coils are gently rubbed over with the fingers until they have thoroughly united and the lines of the spiral have disappeared. The clay disc may now be turned over and the rubbing continued on the other side. The circle is cut true and a new coil is laid on the outer edge thus making a shallow circular tray. In raising the walls it is best to pinch off the roll of clay when one circle has been completed and the new roll should be begun at another point so that all the joints will not be at the same place. This plan is better than coiling a long roll in a spiral for in this case one side of the piece will be higher than the other. After three rolls have been laid in position the wall, both inside and out, should be worked like the bottom so that the rolls will disappear and the clay be welded uniformly together. This should be done without water or with as little as possible. The use of water is very tempting. It makes the clay so smooth and seems to help but it will inevitably make the work sloppy and will tend to soften the walls. After three or four rolls have been worked in, the piece should be laid aside for some hours to stiffen. If this be not done the weight of the second building will cause the work to sag and fall out of shape. For this reason it is well to have two or three pieces in hand at once so that there need be no waiting. When the cylinder is of sufficient height it should be allowed to become quite stiff and then the irregularities should be corrected with a little soft clay which is worked into the joints. The whole surface may now be gone over with tools and brought to the required finish. As soon as the clay is hard enough it should be removed from the damp bat and placed upon a dry one to become dry. In the method of building by pieces no rolls are prepared but the clay is taken, pinch by pinch, each morsel being pressed into place as the work goes on. This plan is somewhat more plastic in effect and is well adapted to free-hand work; the resulting pottery, however, is generally thicker and heavier. The craft of building is not mastered until the lines of a drawing can be successfully followed. The clay is apt to choose its own way and the result will be very different from what the potter intended. The design should be carefully worked out on paper, full size if possible, and the clay form should be compared with the drawing as the building goes on. A profile may be cut in cardboard and this, applied to the clay from time to time, will verify the line, but all such mechanical aids should be used sparingly as the value of this work depends largely upon the sense of freedom and self-expression which belongs to it. The thickness of the clay walls is a matter of great importance. A small piece should not be so thick as to feel clumsy and heavy, nor should a large piece be so thin as to lose the sense of strength and solidity. It may be found on drying the ware, that cracks, especially in the bottom, are developed. The cause of this may be in the clay. A clay which is too plastic or too fine in the grain will surely crack. Such a clay may be opened or meagered by the addition of ground flint or fine grog. The cause may, on the other hand, be in the building. If the welding of the coils or pieces be imperfectly done, cracks are sure to result. If the bottom be too thick it will crack. A great strain is put upon the bottom in drying. The clay must be able to shrink and while the side walls are able to settle down on themselves, the bottom is pulled in every direction by the sides. The bottom should be made quite thin in the center and thicker toward the edges. This will help to avoid cracks. A bad crack cannot be successfully mended. It is best to break the piece and begin again. To burn it means the loss of the clay but the clay will be saved if the damaged work be withheld from the kiln. A small crack on the edge is also hopeless. A crack showing on the edge of a piece is a bad fault. A small crack in the bottom may be mended by dampening the place carefully and pressing in a little stiff clay. CHAPTER IX: THE POTTER'S WHEEL Much of the glamour of the potter's art is associated with the wheel. Poets have sung its praise and artists have delighted in its rhythmic motion, but alas! the wheel as a commercial method of manufacture is doomed to extinction. It cannot compete with the precision and speed of machinery. It devolves, therefore, upon the artist potter to maintain the wheel in its rightful place as, _par excellence_, the potter's tool. No clay worker's studio should be without a wheel, but the particular form of wheel depends upon the nature of the circumstances under which it is to be employed. The simplest wheel is that used by the Chinese. A circular plate with a heavy rim is set upon a spindle so that it will revolve freely and run steadily. As the workman sits or kneels upon the floor the surface of the wheel is about at the floor level. Around the periphery and upon the upper surface four holes are sunk and the workman, inserting a short stick into one of these, gives the wheel a rapid motion. Then while it is revolving by its own momentum the clay is centered and shaped. As the motion is lost the stick is again inserted and the wheel spun. This method, of course, involves much skill on the part of the workman. In the next form, one which is only adapted, however, for crude experimental work, the wheel is set upon the frame of a sewing machine and operated by the treadle. A beginning may be made upon such a wheel but the operator will soon wish for something better. A common factory form and one which is well adapted for studio work is the kick wheel. The wheel head is set at the top of a spindle and in the upright shaft there is a crank to which is attached a horizontal moving treadle. This is worked continuously by the left foot, the weight of the body being supported by the right. The action is strenuous and scarcely fitted for persons of other than robust physique but it can be used successfully after practice. This wheel is made by the manufacturers of potter's machinery. Another form of the kick wheel is used in Europe and is, in fact, the original wheel used by the French and German potters in the seventeenth century. The head is set on a spindle as usual but instead of the crank there is a large heavy disc on the bottom of the shaft and revolving in a horizontal plane. This is within reach of the foot and the operator, being seated, imparts a rapid motion by pushing, usually with the ball of the right toe. The momentum is kept up by the weight of the disc and there is a great advantage in that the foot need not be in continuous motion. On the other hand it is difficult to acquire sufficient speed and power for the work. There are several forms of machine wheels which are entirely satisfactory but which need the application of power. If a gas engine or a water motor or electric current be available, every effort should be made to obtain a wheel of this description. The prime motion is imparted to a short horizontal shaft which moves at a constant speed. Then the operator, seated in comfort, regulates the speed of the wheel itself by pressure upon a treadle. No action is required but a simple pressure, light for a slow speed and heavy for rapidity. Where the electric current is available, nothing could be better. Self-contained motor-driven wheels are available but are rather expensive. One more plan may be mentioned in which the wheel is simply a vertical lathe with a belt and handle to be turned by an assistant. This may be convenient for some but it is not always possible to secure help at the moment when the wheel is to be used. Moreover the cost of labor would soon pay for a mechanical wheel.[G] [G] Information as to the usual types of wheel may be obtained from The Crossley Manufacturing Company, Trenton, N. J.; The Patterson Foundry and Machine Company, East Liverpool, Ohio; a wheel operated like a sewing machine is sold by the Lewis Institute, Chicago. Whatever type of wheel is selected it should be arranged with a head which can be removed. There are two methods of constructing this; the head may be screwed on to the spindle, or the latter may terminate in a cone-shaped plug upon which the wheel head is made to fit as in the illustration (Fig. 14). The latter plan is to be preferred as the head can be removed more quickly and is not so likely to work loose. Several heads for the wheel can then be provided, one for regular work, one for making plates, one for finishing and so forth. The regular operation performed upon the wheel is termed either throwing or turning according to the industry in which it is employed, but in this description the word "throwing" will be used because the subsequent operation in which tools are employed is best described as turning. The best head for the wheel to be used in throwing is made of hard wood or brass because the ball of clay can be easily centered upon a smooth surface. This, however, involves that the work shall be cut off with a wire and removed while soft. This is commonly done by professionals but is beyond the skill of the beginner. It is best, therefore, to use a head like that illustrated for plate making and to have a number of specially shaped plaster bats to fit the recess (Fig. 17). Then when the piece is formed, the bat with its burden can be set aside for the work to harden. [Illustration: Fig. 17. Wheel head with detached bat.] Throwing is not an easy operation to describe but the following instructions in the form of lessons will, with a large amount of practice, enable the student to become fairly expert. Every opportunity should be taken to watch a good potter at work. There are a thousand and one little tricks in the position of the arms, hands, thumbs and fingers which are impossible to describe but which can easily be copied. If a kick wheel be used some time must be given to practicing the motion without using clay. The action of the foot must become subconscious or automatic like the pedaling of a bicycle so that simply to will a change of speed is to accomplish it. [Illustration: Fig. 18. The progress of a clay ball on the wheel.] _Lesson I._ Take the bat about to be used, plunge it in clean water and soak it nearly, but not quite, to saturation. If the bat remain wet one minute after being taken from the water, it has soaked too long and must be dried off a little. The effect of a wet bat is that the clay slips and cannot be held in one place. The proper dampness is secured when the clay ball can be pushed along the surface of the bat but does not slip easily. This condition is important and should be secured by experiment, because if not right, good work will be impossible. [Illustration: PLATE I. THROWING.--LESSON II, 1.] [Illustration: PLATE II. THROWING.--LESSON II, 2.] _Lesson II._ Place a small basin of water close at hand. Take a ball of clay about three inches in diameter. Set it on the center of the wheel as nearly as can be judged. Now spin the wheel at a fairly rapid rate. Brace the left elbow against the side and, wetting the hand, press the ball of the thumb and the lower part of the palm against the clay. The left forearm being kept rigid, the clay as it revolves will be forced into the center of the wheel. Use the right hand to sprinkle water on the clay that proper lubrication may be maintained. With the fingers of the right hand pull the clay towards you, at the same time pressing inward with left hand and so squeezing the clay. As the hands come together the clay will rise in a cone. Do not pull it upwards but let it rise as it is squeezed. Now bring the hands over the top and with the thumbs together press down again. Lumps and irregularities will be felt in the clay and the operations of spinning up and pressing down must be continued until these disappear. Repeat the exercise of centering with a fresh ball of clay until it can be accomplished with ease and rapidity. The clay so used is not wasted. The superfluous water may be dried off upon a plaster bat and the clay wedged up for use again. [Illustration: PLATE III. THROWING.--LESSON II, 3.] This wedging or waging of clay--the word has descended from the old English potters--is important. A strong table should be built of which the top, measuring about 30 by 20 inches, is made of two-inch plank. A raised edge two inches high is fastened firmly by being nailed to the sides; the trough thus formed is then filled with plaster and allowed to harden. An upright post is fastened in the center of one side and from the top of this a fine brass wire is stretched to the other side of the table, thus making a diagonal. The worker stands at the side of the table opposite the post. The ball of clay is taken in both hands and cut in two against the wire, then the pieces are slapped smartly upon the plaster, one on top of the other. The whole lump is then lifted, cut in two and slapped down as before. The lump of clay is thus formed into layers, the irregularities in hardness are corrected and the clay made smooth. A little practice will make the work quite easy but it will often be found necessary to cut and beat the clay fifteen or twenty times before a good texture is secured. If the plaster table be dry the clay will be stiffened rapidly but the plaster may be made wet to prevent this if it should not be necessary. A clay may also be softened in this way by sprinkling it with water as the wedging goes on. [Illustration: PLATE IV. THROWING.--LESSON III, 1.] [Illustration: PLATE V. THROWING.--LESSON III, 2.] _Lesson III._ Center the ball as in Lesson II and moisten both hands and the clay. Grasping the clay lightly but with sufficient force, press the right thumb downwards and towards the palm and a cup-shaped hollow is formed in the clay. Raise the right hand slowly, still keeping a light pressure upon the clay with the thumb. The clay wall will rise with the hand. Now insert the two first fingers of the left hand into the hollow and hold them against the right-hand wall. Slacken the speed of the wheel a little. Bend the forefinger of the right hand and press the second joint and the knuckle against the outer wall so as to oppose the fingers which are inside. Press the thumbs together to steady the hands and raise both hands upwards together. The fingers inside and outside the clay should be kept at a definite distance apart so that as the hands rise, the clay is brought to a uniform thickness. The hands are brought steadily to the full height to which the clay will go and thus a cylinder is formed. Repeat this lesson three or four times with fresh clay. [Illustration: PLATE VI. THROWING.--LESSON IV, 1.] [Illustration: PLATE VII. THROWING.--LESSON IV, 2.] _Lesson IV._ Keep the hands wet. Shape the clay cylinder as directed in the previous exercise. Now repeat the action of the fingers inside and outside and, beginning at the bottom, take a closer grip of the clay and draw up the walls as before. The cylinder is now taller and the walls thinner. Do this again and again taking a little closer grip each time until the cylinder is as tall and as thin as the clay will bear. The walls will probably spread as the work proceeds and the hands must then be used outside. Grasp the clay with both hands and squeeze it slightly; at the same time raise the hands upwards. This will reduce the diameter of the cylinder and thicken the walls. The operation of the fingers can then be repeated until the full height is reached. There is, of course, a limit to the height of the cylinder which can be made from a given lump of clay and it is best to begin on a small scale. A ball of clay which can be easily grasped with the hands is the proper size with which to learn. A very small ball is nearly as hard to work as a large one. Repeat this lesson until a tall cylinder can be made with ease and certainty. [Illustration: PLATE VIII. THROWING.--LESSON V.] _Lesson V._ Keep the hands wet. Spin up a cylinder with thick walls as in Lesson III. With the fingers of the one hand inside and those of the other hand outside, open the cylinder gradually. Keep the wheel at a slow speed. If the edge runs unevenly, use both hands outside to steady it, then work outwards again until a shallow bowl is formed. [Illustration: PLATE IX. THROWING.--LESSON VI, 1.] _Lesson VI._ Keep the hands wet. Spin up a cylinder of medium height as in Lesson IV. With the fingers of the right hand outside press inwards at the base of the cylinder close to the bat and with the fingers of the left hand inside, press outwards at a slightly higher level. This will reduce the diameter at the bottom and increase it in the middle, making a cup shape. Now raise the right hand and gently draw the top inwards. With the left hand inside press the upper edge outward and with the fingers of the right hand shape the upper part into the form of a jar or flower pot. [Illustration: PLATE X. THROWING.--LESSON VI, 2.] [Illustration: PLATE XI. THROWING.--LESSON VII.] _Lesson VII._ Keep the hands wet; proceed as in Lesson VI. Instead of making the top flange outwards, draw it gradually inwards into a globe form. Work the clay carefully upwards and inwards until the opening at the top is almost closed. Several attempts will probably have to be made before this result can be secured. [Illustration: PLATE XII. THROWING.--LESSON VIII, 1.] _Lesson VIII._ Keep the hands wet. Spin up a globe shape with a narrow base as in Lesson VI but carry a good share of the clay to the top so that the upper edge of the globe is quite thick. Insert two fingers of the left hand and with the fingers of the right hand outside work the upper edge of the globe into a tall neck. The action is the same as in the shaping of a cylinder except that the diameter is smaller. A good deal of practice will be necessary in order to keep the neck thin and to raise it to any appreciable height, but perseverance will accomplish it. [Illustration: PLATE XIII. THROWING.--LESSON VIII, 2.] These lessons if carried out conscientiously will enable the operator to produce almost any form in so far as the manipulation of the clay is concerned but the work up to this point is drill only. It is not intended that the pieces should be preserved. The next point is to insist that the clay obey the potter in the shaping of a form. A simple drawing of a jar should be made exact to the size proposed. Two or three pairs of calipers are provided and with them the diameter of each part of the drawing is taken. Of course a single pair could be made to serve, but it is very inconvenient to change measurements while working. A piece of wood also is cut to the height of the proposed piece. The throwing is begun as usual by making a cylinder. This should be higher than the drawing for the clay sinks in the shaping. First the bottom is pressed into the proper size (Lesson VI). Then the body is enlarged to the required measure and, lastly the diameter of the top is taken and the height brought to the determined point. If too high the superfluous clay may be cut off with a pointed knife, the edge being carefully rounded afterwards. It is only by checking up one's work in some such way as this that real power can be acquired. The skilled worker can think in the clay and create forms at will upon the moving wheel, but for the beginner to attempt this is like an endeavor to paint pictures before one has learned to draw. Shape after shape should be designed, drawn to scale and thrown to measure; in fact, for elaborate pieces no other course is possible. CHAPTER X: TURNING It is not possible to finish work to perfection in the operation of throwing. The clay is too soft to handle and for proper finishing the piece must be turned over to get at the bottom. An experienced thrower reduces the final work to a minimum and this, of course, is the ideal plan but even in factory practice every thrown piece is passed on to the turner so that the phrase "thrown and turned" is used as of a single operation, though it, in fact, expresses not only two processes but the work of two men. The artist-potter must needs, therefore, learn to turn, though this process should not be worked to death as it is liable to be. Many persons in the pride of having produced some sort of a form on the wheel will leave it in the crudest possible condition and trust to the turning tool to remove defects. If the lessons on throwing have been conscientiously carried out, this error will not be committed. A half dozen cylinders of convenient size should be thrown on separate bats and set aside in a cool place to harden. They must not be dried but should be in the condition known as "leather hard." If thrown one day they will be ready for turning the next morning. Pieces thus hardened are no longer flexible. They can be handled freely and the clay can be easily cut with a knife. [Illustration: Fig. 19. Turning tools bent and sharpened.] The equipment for turning consists of a board support, a turning stick and a set of tools. The board is of soft pine, eight or ten inches wide and two feet high and is set upright at the back of the wheel frame opposite the workman. It may be screwed in position if it does not interfere with the throwing, or it may be set in a socket so as to be removed when not in use. Its purpose is to support the end of the turning stick. The stick is an ordinary broomstick in the end of which is a sharpened nail. In use the end of the stick is held in the left hand and the point is pressed into the board at any required height. The right hand, holding the tool, is rested on the stick just as the hand of a painter rests on the mahl-stick. The turning tools are of soft steel.[H] They are purchased unshaped and the potter must learn to bend and file them to suit himself. A section of bench should be set apart for filing and care must be taken that the steel dust does not get into the clay. [H] The Milligan Hardware Company, East Liverpool, O. One of the cylinders, with the bat upon which it was thrown, is now taken in hand. Many beginners try to turn their pieces without detaching them from the bat, trusting to the original adhesion to hold the piece in position. This is a very unsatisfactory plan. A fundamental principle in craft work is that the mechanical difficulties in manipulation should be met and overcome at the first. If one trusts to some method which is apparently easy one walks with crutches and there will come a time, if progress is to be made, when such helps must of necessity be abandoned and then the learning must be begun again. Therefore the student is advised to face the mechanical technique at the very beginning. The cylinder may be turned on the throwing bat, but there is a better way. The piece should not become so hard that it will release its hold on the bat but with a long bladed knife it should be cut away. If the knife be held close to the bat a separation is easily effected. Set the leather-hard cylinder upon a new bat which is slightly damp and which runs true, on the wheel. The first problem is to center the work. A pencil line may be run upon the bat making a circle just the size of the cylinder. Then as the wheel is revolved it will be seen if the piece runs true. It is quite unlikely that this will be the case. Perhaps the bottom is true but the top circle is untrue. In other words, the axis of the cylinder is not upright. Turn the cylinder upside down and try if it will run any better. If it does the work may be begun in this position. If it does not, turn it back again. Now take a pencil and hold it with a steady hand so that it just touches the near side as the wheel goes round. Lift up the edge of the cylinder on the side marked by the pencil and slip a morsel of clay under it. Revolve the wheel and try with the pencil again. In this way raise or press down one side, keeping the bottom circle in the center until both top and bottom are running as nearly true as they can be made. This, so far, refers only to the horizontal planes. If one side is higher than the other it does not matter at present. Now take three small pieces of soft clay, and, holding the cylinder firmly with one hand, press them down at equidistant points in the angle where the piece joins the bat. This serves to hold the work in position. A square turning tool of small size is the best to begin with. It is held in the fingers as a pen is held but more firmly. The right hand rests on the turning stick and, the connection between hand and stick being as rigid as possible, both are moved together. This is better at first than moving the right hand freely for to do so will surely result in irregular work. The tool should be held so as to cut with one corner at first and it is well to take one cut, remove the tool, take another cut and so on. The object should be to feel the clay and to test its resistance. No one can be a successful potter who does not cultivate a sympathy for the clay. The tool is to cut, not to scrape. That is, the cutting edge is to be opposed to the revolving clay. The point at which the tool touches the clay is opposite the center or at the same distance from the operator as the center of the wheel is. If nearer to the workman the tool will not cut; if further away, it will scrape and pull (Fig. 5, page 50). The first efforts should be directed towards acquiring skill. The student should endeavor to make a cut at any desired point without regarding the effect upon the shape of the cylinder. In other words the clay is used merely as a practice piece. It is not to be preserved. It is a good plan to keep on turning the first piece until it is all turned away. Too many students fail because they wish to have a piece to keep. He will make the best ultimate success who cares nothing for the preservation of a dozen or two cylinders or other shapes, but uses them merely as exercises in manipulation. If the student is over anxious to avoid spoiling his work, he grows nervous and so loses control of his tools and material. To set no value on the practice pieces themselves begets confidence and this is the surest aid to success. After two or three cylinders have been centered to the pencil line the attempt to center one free-hand may be made. Place a cylinder on the wheel but not quite in the center. Spin the wheel at a medium rate. Fix the attention upon the eccentric motion, trying to forget the circular motion. As the cylinder appears to move from side to side tap it lightly with the hand so as to drive it towards the center. In all probability this will result in driving the cylinder off the wheel altogether. Some little practice is needed, but if persevered in the result will be a power of convenient and rapid centering which is never forgotten and which is the greatest possible help to successful work. One may practice with a wooden cylinder or even a tin can if the weight approximates that of the clay pieces. [Illustration: Fig. 20. Turned feet. _A B C_, feet for small pieces. _D E F_, feet for large pieces. _G H I_, common faults in foot finish.] Accompanying the practice in turning there should be some exercise in the shaping and filing of tools. Broad tools filed to the proper curve are indispensable in finishing concave surfaces. A curved edge may also be put upon one or two narrow tools. These will cut more rapidly than the broader ones but will not leave as smooth a finish. Whatever tool be used the final surface must be worked over with a soft sponge and water so as to eliminate the tool marks and leave a plastic surface. One of the principal troubles with which the beginner will meet is the vibration of the tool known as "chattering." This is sometimes so slight as not to be felt by the hand but when the motion of the wheel is stopped the work will be found covered with fine ridges like gathering on muslin. The way to prevent this is to avoid using the broad edge of the tool until some experience has been gained. The way to cure it is to go over the work again with a fine pointed tool and then to use the sponge liberally. The point of the tool cuts through the small ribs or wrinkles whereas a broad tool would ride over them and make the trouble worse. While the whole surface of the work will probably need more or less turning, the chief part of the operation is concerned with the under part or foot. The formation of a good foot marks a good potter and vice versa. Before beginning to turn it should be decided what kind of a foot is desired. Each shape has its own style. Some sketches are given here with an idea of the form to which each is adapted. They are shown upside down because the work is done in this position. The small bevel at the outer angle is used for facility in glazing. A foot finished thus always has a neat appearance when the glaze has been removed from the beveled face. CHAPTER XI: MAKING LARGE PIECES There is a limit in size beyond which the non-professional will not be able to go. Men of life-long experience can throw very large jars but this involves not only more practice than the artist-potter can hope to secure but also great physical strength. On the other hand it is perfectly possible to form vases two or three feet in height by doing the work in parts or sections. No one need fear to put such a plan in operation on account of sentiment. It is, of course, worth while to make large wares in a single piece but section work involves great skill and, as a rule, the result attained is better. Work made in one piece is apt to be badly finished, especially inside, and unduly heavy. Work made in sections can be thrown with thin walls and finished with proper care. If tradition be of any help, be it known that the Chinese have used the piece method for hundreds of years, and that the Greeks used it three thousand years ago. The first requisite is a drawing either actual size or properly scaled. The measurements should be those of the soft clay and if a particular size be desired in the burned piece, the shrinkage, probably about one-eighth, must be added. The drawing must show the size of each section with the points of junction, and should indicate the upper and lower edges in each case. Some divisions are best made right side up; some are more easily thrown upside down. Care should be taken that the faces which are to be joined are thrown under similar conditions. In every piece of work one face rests on the bat, the other is in the air or free. A bat face should always be joined to a bat face and a free face to a free. Suppose, for instance, a vase is to be sixteen inches high and is to be thrown in four divisions of four inches each. The bottom division is made first. This will stand in its normal position, right side up. The second section must now be thrown upside down, because, if it were not, its bat face would be joined to the free face of the first piece. So the sections are thrown alternately, every other one being inverted. [Illustration: PLATE XIV. MAKING LARGE PIECES. THE FIRST SECTION.] As the pieces are thrown they must be carefully measured to see that the faces which are to be united are the same size. The height of each piece also must be gauged and adjusted. The bats with their contents are now set aside to harden. As soon as they can be handled with safety the clay pieces should be removed from the bats upon which the throwing was done and set upon dry bats which will absorb the moisture and help to stiffen the clay. It is a good plan to pile the sections up as they are to stand in the finished piece, one upon another and to leave them so in a cool place for ten or twelve hours. The faces which are to be joined will thus acquire a uniform hardness and unequal shrinkage will be avoided. When all is ready for the turning, the sections being of the proper hardness are taken in hand. This work should not be hurried. It will take a whole morning to put together a large piece. First, the bottom section is placed on the wheel, centered and made to run true as regards the top edge. It is then inverted and the foot is properly finished, signed and dated. Then the second joint is likewise turned true on both faces, the inside turned smooth; and so on, each piece in turn is prepared for the fitting, the measurement of each face being accurately adjusted. At this stage it is possible to correct the diameter of the faces to some extent either by pressure as the wheel revolves or by building up with soft clay. In either case, however, the new work must be hardened before proceeding. The whole piece is now put together carefully but with dry joints. It should be slowly revolved on the wheel and the proportions carefully criticised. If satisfactory it is taken apart again and the actual fitting up may proceed. The bottom section is again centered most carefully on the wheel and steadied with three pieces of clay. A thick slip is now prepared, the same clay as that used for the work being of course, used. This slip must be quite free from lumps and should be as thick as molasses. The upper edge of the work is carefully sponged with clean water and a good coating of slip is applied at the junction. Care must be taken that every part of the face is covered with slip. The second joint is now moistened at the junction and set in position upon the bed of slip. It is placed very lightly and the wheel is gently revolved to see if the running is true. If so it is pressed home and the superfluous slip is removed. The joint should be quite close like a glued joint in carpentry. In the same way the third section is placed upon the second and the fourth upon the third. It is now possible to work over the face of the vase with a little soft clay. There is almost always some irregularity in the line, especially at the joints, and this must be adjusted while the work is moist. Then the whole face is gone over with turning tools and sponge and the vase is set aside to dry. It must not be expected that large pieces, made by any method, will be produced with as much ease as small vases and bowls. The risks are much greater and, owing to the size of the work, the faults are much more apparent. When the vase is perfectly dry it should be set on the wheel, centered and slowly revolved. If it is very untrue in its motion there is no remedy. It should be broken down and the clay used again. A very slight irregularity may be corrected by rubbing off a little clay on one side of the foot but this cannot be done to any considerable extent. The courage to break unsatisfactory work is never more valuable than at this juncture. It will pay in the end, for no imperfect piece can be a source of satisfaction to the conscientious craftsman. [Illustration: PLATE XV. MAKING LARGE PIECES. Measuring the Foundation of the Second Section.] [Illustration: PLATE XVI. MAKING LARGE PIECES. Drawing up the Second Section.] [Illustration: PLATE XVII. MAKING LARGE PIECES. Shaping the Third Section.] [Illustration: PLATE XVIII. MAKING LARGE PIECES. The Three Sections Completed.] [Illustration: PLATE XIX. MAKING LARGE PIECES. Turning the Edge of the First Section. (Note the other sections on the table.)] [Illustration: PLATE XX. MAKING LARGE PIECES. Finishing the Bottom of the First Section. (Note the second section in the foreground ready for turning.)] [Illustration: PLATE XXI. MAKING LARGE PIECES. Checking the Size of the Second Section.] [Illustration: PLATE XXII. MAKING LARGE PIECES. Fitting Together Dry.] [Illustration: PLATE XXIII. MAKING LARGE PIECES. Setting the Third Section in Place.] [Illustration: PLATE XXIV. MAKING LARGE PIECES. The Three Sections Set Together in the Rough.] [Illustration: PLATE XXV. MAKING LARGE PIECES. The Finished Vase.] CHAPTER XII: CUPS AND SAUCERS AND PLATES It is not likely that many craftsmen will care to produce table wares or even that they will be able to acquire the necessary skill. Simple as these wares seem, they are, in fact, the most difficult of all to make well. In factory working, one man makes nothing but cups, another saucers and another plates, so that each attains the skill of constant practice, but this is out of the question for the studio worker. At the same time it is well to know how it is done and it may be that some one will undertake to produce a few pieces for the sake of the enjoyment arising therefrom. It is possible to finish a cup upon the wheel just as a vase is made. The handle is modeled in clay and fastened in place with slip when in the leather hard condition. Saucers and plates cannot be made in this manner; first, because the broad thin bottom will surely crack and, second, because it is impracticable to turn a plate or saucer over in order to finish the bottom. The risk of breakage is so great that there is nothing to be gained. If cups be needed of uniform size they must be molded. The making of the molds has already been described. A small cylinder of the proper size is thrown in clay and removed from the wheel while soft. A number of these should be made at one time so as to avoid changing the wheel head often. When all are ready a hollow head shaped to receive the cup mold is set on the wheel and a mold inserted. One of the soft cylinders is now lowered gently into the mold and as the wheel is revolved the soft clay is pressed firmly against the walls with the fingers. A piece of wood, called a rib, cut to the exact shape of the inside of the cup, is used to smooth off the interior. The top edge is cut off and rounded and the mold is set aside for the cup to harden. As soon as the cup can be turned out it is set upside down upon the wheel and the bottom turned. Another method dispenses with the formation of the cylinder or "lining." A ball of clay of the proper size is dropped into the mold and pressed into shape with the fingers, the wheel, of course, being spun. The finishing is accomplished with the rib as before. This method will answer for wares which are to receive a low fire but for high temperatures the clay must be handled by the first-named plan. The cup is not complete without a handle. This may be modeled as already stated but to make each one of half a dozen in this way is unduly tedious. The better plan is to model a handle in wax and make a mold as already directed. A roll of soft clay is then laid in the mold, the two halves pressed together and the handle taken out and finished. Care must be taken that cup and handle are of the same degree of moisture, leather hard, for choice, or they will part company as they dry. The fastening is done with thick slip. The method for saucers is the same as that for plates, so that one description will suffice. The first step is to make a tool or profile. A large handful of soft clay is rolled out into a thick cylinder and laid down upon the plate mold. It should extend from the center to the circumference, forming a radius of the circle. The clay is pressed closely to the surface of the mold and part of it is squeezed into a knob which will form the hand-hold of the tool (Fig. 16, page 66). The clay is left in this position until it becomes nearly but not quite dry. It is then taken off and whittled into shape. The front edge must be straight and must lie along a radius of the plate. The foot is cut in at the proper point and a broad wedge-shaped hollow is made so as to gather the clay and pile it up into the foot. The hand-hold is shaped so as to fit comfortably between the first and second fingers of the right hand. When properly shaped the tool is thoroughly dried and then burned in the kiln. The fire must not be severe as it is important not to shrink the tool to any great extent. After burning slight corrections can be made with a file or a hard stone. The heel of the profile must be exactly at the center of the plate and the toe or curve must rest on the outer edge of the plate mold. In making plates a "batting block" and "batter" are used. The former is a heavy block of plaster which is fixed to a strong table. It must be saturated with water when in use. The wedging table already described will serve for this. The batter is a disc of plaster to which a handle is attached. It may be made of a thick plaster block, the handle being cut out of the substance itself. This is also kept saturated with water so that the clay will not stick. A ball of clay is laid on the block and gently beaten out with the batter into a disc of the proper size and thickness. The face of this is then polished with a steel blade and the disc is then lifted, turned over and laid, polished side downward, upon the mold. The wheel is then revolved and the clay pressed firmly to the mold with wet hands. The tool is now dipped in water and pressed steadily upon the revolving clay. The heel must be adjusted accurately to the center and the foot will be seen to rise up in its proper place. The operation is not easy and many failures must be expected but practice will accomplish the desired result. When leather hard the plate is gone over with a thin piece of rubber and when quite hard it may be removed from the mold. The edge is now trimmed and the face sponged over and the plate is ready for the kiln. CHAPTER XIII: CASTING In commercial production the casting method is constantly used. It is a means of making light and delicate pieces with ease and, of course, all the pieces cast in the same mold are alike. This very fact, however, has led to the method being disregarded by the studio worker who does not wish to duplicate anything that he makes. If a single piece only is to be made the work involved in molding is a waste of time and it is better to strive for skill at the wheel, and yet there are occasions when a knowledge of casting is of great value. In the preparation of trial pieces there is no method better. To make these in sufficient number on the wheel would be tedious except for the benefit of the practice involved. Directions for making molds have already been given and the slip which will have been prepared in the process of clay making is ready for the casting process. This slip should be thick, about the thickness of buckwheat batter. To be accurate, a pint should weigh 26 ounces. For small pieces or for vases with narrow necks it is advisable to use the slip rather thinner. For large wares, on the other hand, or for open bowls it may be slightly thicker. A few experiments will show the reason for this. Two quart jugs are needed. They should be large of neck and should deliver their contents freely and completely. Jugs with a deep shoulder are not good as the slip hangs in the pouring. One of these jugs is filled with slip which is to be poured carefully from one to the other, allowing it to flow gently down the side. This is to break the air bubbles which are nearly always found to be present and the pouring should be repeated until the slip flows smooth and even. The mold, being thoroughly dry, is tied around with twine, if in parts, and wedged firmly so that it cannot leak. The slip is then carefully poured so as not to touch the sides and the mold is filled until a small mound of slip rises over the edge. This mound will at once begin to sink as the water is drawn into the walls of the mold and slip must be added, little by little, to make good the loss. A small quantity of clay will now be found to have stiffened at the rim of the mold and if this be carefully removed with a steel tool the thickness of the wall of the vase will be seen. If not thick enough the mold must be continually filled up until the necessary thickness is attained. The mold is then carefully lifted, making sure that the bottom is held firmly, and the slip is poured out. It should not be poured back into the casting-jug but into another vessel. The mold is now set upside down to drain. It should not be placed upon the table but upon two sticks laid parallel so that the drip may hang clear. Several molds may be filled in this way at one time and after about twenty minutes the one first filled may be opened. The bottom is gently detached and the upper part of the mold, consisting of two halves, is laid upon the table on its side. A little gentle manipulation will now suffice to lift the one half and the vase will be seen lying in the other half as in a cradle. The clay is still very soft and must be treated carefully. The half mold, with the contained vase, is taken in the left hand and held nearly upright, the fingers below, the thumb on the top. Now set the fingers of the right hand under the bottom of the vase, rest the thumb lightly against the side and tilt the half mold gently forward. If mold and clay are in good condition the vase will fall forward to be supported on the fingers of the right hand and steadied by the thumb. The half mold is now laid down and the vase taken in both hands, set gently on a plaster bat and put aside to dry. It often happens that the vase leaves the mold with reluctance. If the slip be very new, or the mold either damp or hard or worn out there will be some difficulty in effecting a separation. By allowing the work to stand a while, however, and by slightly jarring the mold from time to time with the ball of the thumb the piece can generally be removed without damage. In using a new mold it is customary to make what is called a "waste filling." The mold is filled with slip and at once emptied. After standing a few minutes it is forcibly opened and the thin layer of clay inside is picked out with a ball of plastic clay pressed against it. A tool should never be used as this will damage the face of the mold. If the clay should stick obstinately a soft cloth used over the finger will remove it. The reason for this waste filling is that it removes the scum which occurs on all new molds. Cast ware should not be touched until quite dry and then the spare at the neck is carefully cut off, the seams scraped down and the whole surface smoothed with fine sand paper and a soft cloth. Worn out linen serves excellently for this purpose. Cups and bowls, if molded, are made without spare at the top. In this case great care must be taken to see that the edge is left clean and smooth in the casting. The spare neck on a vase acts as a margin of safety, as it is completely cut away in the finishing. If a piece has no spare the edge must be left without blemish at the first. CHAPTER XIV: TILES There are two methods of making tiles, the dust-pressed method and the plastic. The former is the more usual commercial plan but the appliances for preparing the dust and the heavy presses necessary are not adapted to studio work. The dust-pressed tile is, moreover, somewhat mechanical in surface. It is not suitable for modeling or for any treatment but those of glaze and color. The plastic tile, on the other hand, may be treated by plastic methods and the surface offers a texture which appeals strongly to the artist. For the successful production of tile a special body is necessary. Ordinary pottery clay is too close in grain and straight tile cannot be made from it. Small square pieces, however, such as tesseræ, can be made from any clay. It is presumed that a pure white tile body is not required. For studio work the most pleasing white surface is found in an opaque enamel, but for the most part the craftsman will wish to work for colored tile. A cream or buff body is all that is necessary, therefore, and the foundation of this is a clay known as sagger clay. In order to secure the necessary porosity a fine "grog" must be used. Grog is burned clay. After working awhile there will be an abundance of this in broken unglazed pottery but at first some soft fire-bricks must be pounded. This is laborious work, but a boy can usually be hired to do it. The brick or broken pottery is crushed in an iron mortar but should not be broken too fine. Two sieves are necessary, one of 20 and one of 40 meshes to the linear inch. The coarse powder which passes through the 20 mesh and lies upon the 40 mesh is used. This is called 20-40 grog. The dust which passes through the 40 mesh may be saved for kiln work. It is useful for setting biscuit pieces one upon another as it will effectually prevent sticking. This powdered grog is also useful in the case of flowing glazes. A thick layer on the bottom of the kiln will catch any drops of glaze and save the kiln from damage. A quantity of the 20-40 grog having been prepared, a mixture should be made of:-- Sagger Clay 550 parts 20-40 Grog 300 parts Ground Flint 150 parts The clay should be finely pulverized and the whole mixed in the dry state. Water is then added, little by little, until a rather soft mass is obtained. It is not practicable to mix clay of this description by the slip method because the grog would settle out and fall to the bottom of the vessel. It sometimes happens, however, that the stoneware clay contains grains of iron which cause black spots to appear in the tile. If these cause trouble the clay must be made into slip first and lawned through 120 mesh. It is then allowed to become very thick and the grog is stirred in. This is a good deal more trouble than the first named plan and is not often necessary. Tile are sometimes made in plaster molds. A tile of the proper size is cut from a plaster block and a mold is made from it. If a modeled surface be desired clay may be modeled upon the face of the plaster tile before the mold is made. The mold will then receive the embossment in reverse and all the tiles made from this mold will be alike. The clay is pressed into the mold while quite soft and is scraped off level at the back. Thus it is the face of the tile that is shaped by the plaster. If this plan be adopted the tile must be removed from the mold as soon as possible. If left to dry in the mold they will warp because of the unequal absorption. A better method has been devised by the author and has been put into practice with considerable success. When the size of the proposed tile has been determined a board is made which is large enough to hold a square of the tile, say twelve or sixteen. Thus if a tile five inches square is to be made the board would be fifteen by twenty inches for twelve tile or twenty inches square for sixteen. On each side of the board a wooden rim is fastened and this must stand higher than the board to the exact thickness of the tile. About five-eighths of an inch is enough. The board must be perfectly rectangular and marked off at even distance of five inches and a shallow groove is cut at each point. To make the tile the board is wetted and an even coating of grog dust is sprinkled upon it. A ball of clay is laid in the center of the board and rolled out with a rolling pin to fill every part of the frame. With a straight edge the clay is struck off smooth and clean, working always from the center outwards. Reversing the plaster mold method the tile are now face upward and any kind of surface may be given at will. The clay may be lubricated with water and made smooth or it may be sprinkled with grog dust which will give a sandy or toothed finish. The square is now to be cut into tile and this is done with a slender knife and ruler. The ruler should not rest upon the clay but upon thin strips of wood or cardboard which may be laid along the edges for the purpose. The cutting should not go quite through the clay as, if a slight connection be allowed to remain at the bottom, the tile will keep each other straight. When the cutting is finished the board should be set at an angle of forty-five degrees for the clay to harden. When leather-hard the whole may be turned gently over and the tile allowed to fall on to a board placed in readiness. They are now broken apart, trimmed if necessary and set aside to dry. Tile made in this way can be kept straight without difficulty and the method is much more expeditious than pressing in plaster molds. If a modeled surface be intended it is quite easy to work on the tile in the tray while the clay is soft. Forms may be cut in wood and pressed into the clay in any variety and the charm of individual treatment is preserved. The body given above will prove quite porous when fired but it will take matt glazes well. A little crazing is no detriment to tile because they are not like vessels which are meant to hold water. If a denser body be wished for some of the flint may be replaced by spar. One of the most attractive methods of decorating tile is by means of a white or delicately tinted enamel and color. The opaque tin enamel given on page 134 will answer well and if the whiteness prove too intense it may be modified by a very small addition of under-glaze color according to the tint desired. The tile should be glazed rather thick. Not as thick as a matt glaze but thicker than bright glazes. The glaze or enamel should be poured into a flat tray which is large enough to receive one tile. The tile is taken by the edges between fingers and thumb and held face downwards. Do not let either fingers or thumb project beyond the face. The glaze having been well stirred the face of the tile is allowed to rest upon it for about two seconds. The hand is then lifted quickly and reversed so that the tile is face upwards. Every effort should be made to avoid streaks or tears and a little practice will accomplish this. If the glaze shows a bad surface it should be scraped off. It can be mixed up and used again. Sometimes a slight wetting of the tile before glazing will help the surface to flow evenly. The decoration is carried out with ordinary under-glaze colors. These may be mixed together to produce any hue which is sought and a little of the glaze itself, about ten per cent., should be mixed with the color. This will assist in uniting the color with the glaze so that they melt together. To produce enamel decorations at their true value the color should be painted upon the dry glaze before it is burned. The best relation between surface and color is thus secured. The color must be worked quite thin with water and a little glycerine. A quick, sure stroke is needed as no change or erasure is possible. The design may be made on paper and traced or pounced on to the glaze with lamp-black. For burning the tile there is nothing better than little fire-clay boxes. These can be made in a mold without difficulty and the inside of each should be washed with glaze. If some such protection be not provided dirt is almost sure to fall on the flat surface and the tile will be spoiled. It is not possible to rear them on edge in the kiln for burning as then the glaze would flow to the lower side and cause an unsightly ridge. CHAPTER XV: GLAZES AND GLAZING PART I Much of the fascination of pottery making centers in the glaze. At one time a great deal of mystery appeared to surround the composition and use of glazes, but if one will take the trouble to learn, much of this may be dispelled. Some knowledge of chemistry is desirable if an understanding of the theory of glaze-making is to be acquired, but a good deal may be learned even without this knowledge. Only such simple instruction as can be assimilated by ordinary intelligence will be attempted here, as an exhaustive treatment of the subject would be long and tedious. It is possible to purchase glazes ready for use[J] but the true craftsman will not be satisfied until he can prepare his own. [J] The Roessler & Hasslacher Chemical Company, 709 6th Avenue, New York City, manufacture glazes according to the recipes of the author, and also chemicals for use in the laboratory. Glazes[K] belong to a class of chemical compounds known as silicates; that is, they have silica as the characteristic ingredient. Clear glazes are compound silicates of lead, zinc, lime, potassium, sodium, aluminum and boron. Matt glazes are characterized by certain of these ingredients being present in excess; and stanniferous or tin glazes are, as the name implies, rendered opaque by the use of oxide of tin. [K] It is admitted that glazes are not chemical combinations but solid solutions, but the principle is more easily understood when the analogy of chemical action is adopted. The commonest type of glaze is that which is made from ready prepared, commercial substances. These are called raw glazes as being made from raw materials or materials which need no preparation. It is possible to mix a glaze in a druggist's mortar by hand, using fine sieves, but if the best results are to be secured, a small mill must be used for grinding. The best form of mill is the ball mill or jar mill. This consists of a porcelain jar which is set in a frame and made to revolve upon its axis in a horizontal position. It is about half filled with porcelain balls and these as they roll against each other perform the grinding. These mills may be purchased ready for use, either as a single jar to be worked by hand or a battery of two or more revolved by power.[L] [L] Paul O. Abbé, 30 Broad Street, New York City. A good pair of scales is a necessity and it will be found convenient to use metric weights which need no calculation into pounds and ounces. Suspended scales are not as easy to use as the form known as counter scales or balances. They should have movable pans which are usually nickel plated. Upon these the materials can be placed direct without the use of pieces of paper, which are always troublesome and inaccurate. There should be a graduated bar on the front for the adjustment of weights of five grams and under. This avoids the use of small weights which are always being mislaid and lost. Dealers in chemical supplies keep these scales in stock and the cost is about eight dollars. A set of weights must also be procured from one hundred grams to five grams inclusive. These need not be of the accurate adjustment which are used in analysis. A good inexpensive grade is sufficient. The ingredients for glazes are given in the following list: Commercial Chemical Symbol or Equivalent Name Name Formula Weight White Lead Lead Carbonate Pb(OH)_{2}2PbCO_{3} 258 Zinc Oxide Zinc Oxide ZnO 81 Soda Ash Sodium Carbonate Na_{2}CO_{3} 106 Niter Potassium Nitrate KNO_{3} 202 Whiting Calcium Carbonate CaCO_{3} 100 (Carbonate of Lime) Feldspar Orthoclase K_{2}O,Al_{2}O_{3},6SiO_{2} 557 Kaolin Aluminum Silicate Al_{2}O_{3},2SiO_{2},2H_{2}O 258 or China Clay Flint Silica SiO_{2} 60 Borax Sodium di Borate Na_{2}B_{4}O_{7}10H_{2}O 382 Boric Acid Boric Acid B_{2}O_{3}3H_{2}O 124 For coloring, the following metallic oxides are used: Color Chemical Symbol or Equivalent Name Formula Weight Blue Cobalt Oxide CoO 80 Blue and Green Copper Oxide CuO 79 Gray and Brown Nickel Oxide NiO 75 Brown and Yellow Iron Oxide Fe_{2}O_{3} 160 Brown Manganese Carbonate MnCO_{3} 115 Under-glaze colors may also be used for coloring glazes, the color being ground with the glaze batch. It is not absolutely necessary to commit the formula and equivalent weight to memory. They will soon be remembered as use becomes second nature. A glaze is usually expressed as the chemical formula. In this there are three divisions given, each of which expresses a distinct function. On the left hand are the bases, the foundation of the glaze. These indicate the type, such as lead glaze, a lime glaze, an alkaline glaze, etc. All glazes being silicates, this is the usual way of distinguishing them. In the center are the alumina and boron oxide. These regulate the behavior of the glaze in the fire. They make it viscous or sluggish as it melts and prevent a too rapid flow. The alumina is infusible, the boron is fusible, but boron cannot be used in a raw glaze for reasons to be presently explained. At the right stands the silica, the dominating factor with which all the other ingredients combine, and which controls the behavior of the whole as regards the fitting of the glaze to the body. The very simplest form of glaze is a bisilicate of lead, represented by the formula PbO, SiO_{2}, or one equivalent of lead oxide and one of silica. The term "equivalent" means that the mixture is calculated, not upon the actual weight of a substance but upon its equivalent or unit weight. Thus the equivalent weight of lead oxide, PbO, being 222, in order to produce the formula in actual weight 222 grams or pounds must be weighed out. It does not matter what weights are used so long as they are the same for all. In like manner the equivalent weight of silica is 60 and as flint is pure silica, the formula PbO, SiO_{2} would be produced by weighing-- Litharge or Lead Oxide 222 parts Flint or Silica 60 parts Litharge is not, however, a convenient substance to use. It is very heavy and does not mix well in water. The most usual substance for the introduction of lead oxide is white lead. This is not lead oxide but it changes to lead oxide when burned. White lead bears the formula Pb(OH)_{2}, 2PbCO_{3}, which, being dissected is found to be 3PbO, H_{2}O, 2CO_{2}. H_{2}O is water and CO_{2} carbonic acid, both of which pass off in burning. Both, however, are weighed when the white lead is put on the scales and therefore the equivalent weight of white lead is 258 and not 222. The mixture for practical purposes then would be-- White Lead 258 parts Flint 60 parts Which, when ground and spread upon the ware would be a very fusible glaze of a yellowish tone. This was spoken of as a bisilicate of lead because the measure of the silica, also called the acidity of a glaze, is calculated upon the oxygen contained in the base and the silica respectively. PbO contains one molecule of oxygen, SiO_{2} contains two. Hence the relationship of the oxygen in the base to the oxygen in the silica is as one to two. This is called simply the "oxygen ratio" and is of great importance in determining the behavior of a glaze. While this simple bisilicate of lead will be a glaze under certain conditions it is found to possess two faults. 1. It is too fluid under fire. The glaze will run down a vertical surface and leave the upper edge of the piece bare. 2. If subjected to a long slow fire it will lose its gloss and become devitrified. This devitrification is often seen in commercial work and appears as a dull scum in patches and around the edges of the ware. It is, in fact, a crystallization of the silica which separates out, as salt does from an evaporated brine. Both these faults may be corrected by the addition of a little alumina to the glaze. A whole equivalent of alumina would be too much, in fact it is found in practice that .2 equivalent is sufficient for most lowfire glazes. In order to maintain the oxygen ratio and to keep the glaze as a bisilicate the silica content must be raised. Alumina contains three molecules of oxygen so that the total amount of alumina is multiplied by three and the silica brought to the equal point thus: PbO, .2Al_{2}O_{3}, 1.6SiO_{2} The amount of silica required in any bisilicate glaze may be found by the following equation: SiO_{2} = 2(3Al_{2}O_{3} + 1)/2 Thus if the alumina content were .25 equivalent this would be expressed: SiO_{2} = 2(.75 + 1)/2 Or-- SiO_{2} = 3.50/2 = 1.75 equivalent Now in order to produce this as a mixture it would be possible to introduce the alumina in the pure state, but pure alumina is expensive and clay which contains alumina is cheap so that clay is generally used to supply the alumina. Clay, however, contains silica as well, and therefore allowance must be made for this. On referring to the formula for kaolin, the purest form of clay, Al_{2}O_{3}, 2SiO_{2}, 2H_{2}O, it will be seen that there is twice as much silica present in equivalence as there is alumina and therefore .2 kaolin will contain .2Al_{2}O_{3} and 4SiO_{2}. Subtracting, then, the 4SiO_{2} from the 1.6SiO_{2} needed there will be 1.2 left to be supplied in the form of flint. The mixture therefore is-- White Lead 1.0 × 258 = 258 Kaolin .2 × 258 = 51.6 Flint 1.2 × 60 = 72 This is a glaze of the same character as that first given except that it no longer flows unduly from the higher places nor will it devitrify in a long-continued fire. The alumina will have counteracted both these evils. A glaze with only lead oxide as the base is not, however, desirable for general use. The color is yellowish and the lead oxide is apt to destroy the hue of any colors which are used with it. The available bases may be classified under three heads. 1. The metallic oxides, lead and zinc oxides. 2. The alkaline earths, the oxides of calcium and barium. 3. The alkalies, potash and soda. Barium oxide is not often used and soda cannot be used in raw glazes because there is no convenient substance which contains it. As glazes are always ground in water only insoluble ingredients can be employed without preparation. Potash is found in feldspar which is insoluble and while there is a so-called soda feldspar it can rarely be obtained of sufficient purity. In arranging the bases with which to compose a glaze it is desirable to use one at least from each class, but it must be borne in mind that however many bases are introduced the total must always be unity. This unit is, for the sake of brevity, described as RO. For example the following groups may be set forth: 1. PbO Lead Oxide .7 CaO Calcium Oxide .3 --- RO 1.0 2. PbO .6 CaO .4 --- RO 1.0 3. PbO Lead Oxide .5 ZnO Zinc Oxide .2 CaO Calcium Oxide .3 --- RO 1.0 4. PbO .6 ZnO .1 CaO .3 --- RO 1.0 5. PbO Lead Oxide .6 CaO Calcium Oxide .3 K_{2}O Potassium Oxide .1 --- RO 1.0 6. PbO .50 CaO .35 K_{2}O .15 ---- RO 1.00 7. PbO Lead Oxide .45 ZnO Zinc Oxide .10 CaO Calcium Oxide .30 K_{2}O Potassium Oxide .15 ---- RO 1.00 8. PbO .35 ZnO .15 CaO .35 K_{2}O .15 ---- RO 1.00 The reason for the unit rule is that if one formula is to be compared with another there must be a uniform basis upon which to work and, furthermore, it makes no difference whether the silica combines with one, two, three, or four bases, the chemical action is the same and, so long as the sum of the bases is kept at unity, the same amount of silica will be required. If two glazes be taken as an illustration this will be made clear: PbO .6 } CaO .4 } --- } Al_{2}O_{3} .2 SiO_{2} 1.6 1.0 } PbO .46 } ZnO .12 } CaO .28 } K_{2}O .14 } ---- } Al_{2}O_{3} .2 SiO_{2} 1.6 1.00 } Both of these formulae are bisilicates and each being properly fired, will stand, without crazing, on the same body. The use of the formula is to give an insight into the composition of the melted glaze. It takes no account of volatile ingredients or losses in the fire but for this very reason it must be translated into the substances to be weighed before use can be made of it. Of the ingredients given on pages 142, 143, some contain but one item of the formula, others contain several, as in the case of kaolin already cited. Feldspar, of the variety known as potash feldspar and named by mineralogists, "orthoclase," is a very useful ingredient in raw glazes, being, in fact, almost the only source of potash. The formula, page 142, shows that a molecule or equivalent of feldspar contains one molecule of potash K_{2}O, one of alumina Al_{2}O_{3}, and six of silica SiO_{2}. This fact is taken into account in calculating the mixture or batch weight. Base No. 5 (page 148), is as follows: PbO .6 CaO .3 K_{2}O .1 ---- 1.0 And this made up into a bisilicate glaze would be: PbO .6 } CaO .3 } K_{2}O .1 } ---- } Al_{2}O_{3} .2 SiO_{2} 1.6 1.0 } These items are extended in a horizontal line, a space being left on one side for the list of ingredients. PbO CaO K_{2}O Al_{2}O_{3} SiO_{2} .6 .3 .1 .2 1.6 Addition .6 White Lead .6 ---------------------------------------- Subtraction .0 .3 .1 .2 1.6 Addition .3 Whiting .3 ---------------------------------------- Subtraction .0 .1 .2 1.6 Addition .1 .1 .6 Feldspar .1 ---------------------------------------- Subtraction .0 .1 1.0 Addition .1 .2 Kaolin .1 ---------------------------------------- Subtraction .0 .8 Addition .8 Flint .8 ---------------------------------------- Subtraction .0 Each item is thus disposed of until the list is complete. These figures are, however, given in equivalents and each must be multiplied by the equivalent weight of the substance used. White Lead .6 × 258 = 154.8 parts by weight Whiting (calcium carbonate) .3 × 100 = 30.0 " " " Feldspar .1 × 557 = 55.7 " " " Kaolin .1 × 258 = 25.8 " " " Flint .8 × 60 = 48.0 " " " ----- 314.3 Batch of Glaze These amounts are weighed out in grams, put upon the mill with half a pint of water, and ground for about an hour. When taken off, the jar and porcelain balls are washed with plenty of water and the washings saved. The glaze, thus diluted, is strained through a lawn of 120 mesh and laid aside to settle. The clear water is then siphoned or poured off and the glaze is ready for use. For glazing the glaze should be as thick as cream. A finger dipped into it should show a white coating which cannot be shaken off. The pottery to be glazed should be first soaked in clean water until all absorption has ceased. It is then wiped dry and plunged into the glaze bath, or, if the piece be large, the glaze may be poured over it. The piece is gently shaken to distribute the glaze evenly and it is then set aside to dry. Before glazing a piece everything should be prepared. A stilt or support upon which to set the wet glazed pottery, and a bowl of water in which to wash the fingers so as to save all the glaze. It will be found best to glaze the inside of the piece first. It should then be well shaken to remove as much glaze as possible before beginning the outside. A thick glaze inside is almost sure to run down to the bottom where it will form a pool and perhaps burst the piece. Before firing, the bottom of the pottery should be carefully trimmed. Any excess of glaze is removed and the point of contact with the table is sponged clean. Then, when the piece is set in the kiln the bottom will not be inclined to stick. PART II: MATT GLAZES The texture of the matt glaze is always pleasing and the artist is not content unless at least some of his work can be finished in this way. Matt glazes are not underfired glazes nor are they deadened by acid or sand blast. They are produced in two ways. First, by an excess of alumina which is believed to cause the formation of certain compounds in the glaze, and, second, by an excess of silica which produces a devitrified surface. It was mentioned in the last chapter that a glaze free from alumina will devitrify or become dull. This is undesirable when a glaze is intended to be brilliant but it may be controlled and turned to advantage in the production of a certain type of matt. The successful preparation of this silica matt is extremely difficult. In fact, in the studio kiln it is almost impossible. These small kilns are apt to cool with great rapidity whereas, in order to produce the silica matt the kiln must be cooled very slowly, hours and even days of cooling being sometimes necessary. The alumina matt is more simple and its texture is quite satisfactory, being, in the opinion of some, the more pleasing of the two. It was mentioned in the last chapter that the best bright glazes for low temperature work are bisilicates, having an oxygen ratio of 1:2. The alumina matt has an oxygen ratio of about 3:4. This is secured in the following manner. The RO content may consist of any of the bases used in bright glazes, the proportion of each being adjusted in accordance with the desired point of fusion. The alumina content is rather higher than in a bright glaze and should not fall much below .3 equivalent, .35 equivalent is even better. The silica is adjusted in accordance with the following equation: SiO_{2} = 3(3Al_{2}O_{3} + 1)/4 Now if the alumina content be placed at .35 equivalent this would work out: SiO_{2} = 3(1.05 + 1)/4 Or: SiO_{2} = 6.15/4 = 1.5375 But as such a complete fraction is not necessary it may be stated as 1.54 equivalent. The formula would therefore be: RO, Al_{2}O_{3} .35, SiO_{2} 1.54 The RO content should not be too fusible. Lead oxide is desirable up to about .5 equivalent and it is an advantage to use feldspar so that K_{2}O may be introduced. Calcium oxide is also good but zinc oxide must be used sparingly as it is apt to suffer if overfired. The high content of alumina necessitates a good deal of clay and as this, if used raw, would make the glaze too plastic and cause it to crack, it is best to calcine a part of it, thus removing the combined water and changing the equivalent weight from 258 to 222. The calculation will then proceed as in the case of a bright glaze. PbO .50 } CaO .35 } K_{2}O .15 } ---- } Al_{2}O_{3} .35 SiO_{2} 1.54 RO 1.00 } PbO CaO K_{2}O Al_{2}O_{3} SiO_{2} .50 .35 .15 .35 1.54 Addition .50 White Lead .50 × 258 = 129 ---------------------------------------- Subtraction .0 .35 .15 .35 1.54 Addition .35 Whiting .35 × 100 = 35 ---------------------------------------- Subtraction .0 .15 .35 1.54 Addition .15 .15 .90 Feldspar .15 × 557 = 83 ---------------------------------------- Subtraction .0 .20 .64 Addition .15 .30 Calcined Kaolin .15 × 222 = 33 ---------------------------------------- Subtraction .05 .34 Addition .05 .10 Kaolin .05 × 258 = 13 ---------------------------------------- Subtraction .0 .24 Addition .24 Flint .24 × 60 = 14 ---------------------------------------- Subtraction .0 The mix, therefore, is: White Lead 129 grams Whiting 35 " Feldspar 83 " Calcined Kaolin 33 " Kaolin 13 " Flint 14 " This will give a silky matt glaze, nearly white, maturing at about cone 1. If a lower fusing point is desired the white lead may be increased at the expense of the whiting or if the glaze prove too fusible the reverse will correct it. The flint may be omitted without damage. The grinding of a matt glaze is of great importance. It is better to have it too coarse than too fine. Grinding for one hour on the ball mill should be ample and if the glaze be then strained through 120 mesh lawn all coarse particles will be arrested. A glaze that is too fine will crack and peel off or will curl up in the kiln. More than half the success of matt glazes lies in the using. It is necessary that the coating of glaze be very thick or the true texture will not be developed. When the glaze is taken from the mill plenty of water may be used in order to wash the apparatus clean and to save all the glaze. This is set aside in a deep bowl to settle. After some hours the clear water is carefully drawn off with a siphon. Half an ounce of gum tragacanth is put to soak in a quart of clean water. After twelve hours the gum will have swollen to a jelly-like mass. This is now worked vigorously with a Dover egg-beater or in a Christy mixer and again set aside. After another twelve hours the operation is repeated and the solution is a clear syrup of the consistency of thin molasses. A drop or two of carbolic acid or other germicide should be added to prevent decomposition. This mucilage should be prepared in advance. To the glaze batch from which the water has been removed a tablespoonful of the mucilage is added. If more of the glaze than the single batch has been weighed out then more mucilage will be necessary. The mixture is to be stirred very thoroughly and it will be found to thicken under the hand. It must be very much thicker than the bright glaze. In fact, the thicker it is the better, only that it must flow sufficiently so that the pottery may be covered with a smooth coating, avoiding lumps. Matt glazes do not correct their own faults in the kiln as bright glazes do. Every finger mark will show and, consequently, the glazing must be done with the greatest care. The process is the same as that described for bright glazes, except that as much glaze as possible is left on the ware. No more shaking should be done than will suffice to secure a smooth coating. It is well to place the pieces upside down to dry. For the inside of the pieces a matt glaze may be used or a thin coat of clear glaze at the pleasure of the worker. If the latter, care must be taken that none of the inside glaze is allowed to run over the edge. In firing, the pottery is sometimes placed on a stilt but this is not absolutely necessary. For a support a flat piece of burned clay may be used and this should be covered with an infusible wash to prevent any possibility of sticking. Equal parts of kaolin and flint make a good wash. The wash is worked up with water into a slip and applied with an ordinary brush. PART III: FRITTED GLAZES Fritted glazes, like raw glazes, are clear and brilliant and for most purposes the latter will suffice. Since, however, the aim of this work is to give as complete information as may be the fritted glaze will not be omitted. A fritt is a melt or compounded glass and the purpose of it is to permit the use of certain ingredients which are not available in the raw state. As glazes are ground in water it is essential that the substances used be insoluble. This condition would prohibit advantage being taken of borax, boric acid, and soda ash, if it were not for the possibility of rendering these insoluble by the operation of fritting. The following is an example of a fritted glaze: PbO Lead Oxide .30 } ZnO Zinc Oxide .15 } } Al_{2}O_{2} Alumina .15 } CaO Lime .25 } } SiO_{2} Silica 2.65 } B_{2}O_{3} Boric Acid .40 } Na_{2}O Soda .20 } K_{2}O Potash .10 } This will be produced in accordance with the usual calculation by the mix: White Lead .3 × 258 = 77 Zinc Oxide .15 × 81 = 12 Whiting .25 × 100 = 25 Borax .20 × 382 = 76 Feldspar .10 × 557 = 56 Kaolin .05 × 258 = 13 Flint 1.95 × 60 = 117 The borax contains the required amount of both soda and boric acid and the potash is supplied by the feldspar. Borax, being soluble, must be melted with certain other ingredients into an insoluble glass, thus: Fritt: Borax 76 x 2 = 152 Whiting 25 x 2 = 50 Feldspar 30 x 2 = 60 Flint 50 x 2 = 100 --- 362 These ingredients are weighed out in double quantity to guard against loss in melting and are fused either in the kiln or in a special furnace. A good fritting furnace is the No. 15, made by the Buffalo Dental Manufacturing Company. The charge is put into a plumbago crucible and when melted is poured out into water. This breaks up the fritt and renders it easy to grind. A similar crucible may be used in the kiln but as the fritt becomes very hard when cold and a crucible must be broken each time, the furnace method is better. If the fritt as given prove too sluggish to pour freely, the feldspar may be omitted, being added, of course, to the glaze mix. The melted weight of the fritt must now be calculated. Borax contains in each equivalent 180 parts water. Whiting contains in each equivalent 44 parts carbonic acid. Both water and carbonic acid pass off in the melting, thus the 76 parts of borax will be reduced in weight to 40 parts, and the 25 parts of whiting will be reduced to 14 parts. Spar and flint undergo no loss. The fritt after melting will therefore be: Borax 40 Whiting 14 Spar 30 Flint 50 --- 134 And the final mix for the glaze will be: Fritt 134 parts White Lead 77 " Zinc Oxide 12 " Feldspar 26 " Kaolin 13 " Flint 67 " This is ground on the mill as already directed and is ready for use. Fritted glazes are better than raw glazes for certain classes of ware. They are usually whiter and less easily scratched. They are, moreover, better for use with underglaze colors and are, as a rule, more easily melted. It is never necessary to make a fritt for the preparation of matt glazes. PART IV: RECIPES While the purpose of this work is not so much to put ready-made materials into the hands of the craftsman as to enable him to work out his own plans, it is recognized that there are some workers who lack the training and even the patience to do this. For these, the following recipes are given, but with the proviso that no recipe can be regarded as perfect for all conditions. Just as an untrained cook can spoil a dinner even when surrounded by cookery books, so the best of recipes will fail when unskillfully treated. One must be prepared to recognize the faults which are sure to develop and to correct them in an intelligent manner. The previous chapters should therefore be carefully studied, not alone for the information but because "the joy of the working" depends greatly upon the knowledge one has of the operations involved and a modest confidence in one's own powers. 1. Bright raw glaze. Cone .06 Formula PbO .60 } CaO .25 } Al_{2}O_{3} .15 SiO_{2} 1.45 K_{2}O .15 } Mix: White Lead 155 Whiting 25 Feldspar 55.7 Kaolin 13 Flint 45 Grind, with one-half pint of water, for one hour. 2. Bright raw glaze. Cone 1 Formula PbO .45 } ZnO .15 } Al_{2}O_{3} .20 SiO_{2} 1.60 CaO .25 } K_{2}O .15 } Mix: White Lead 116 Whiting 25 Zinc Oxide 12 Feldspar 83 Kaolin 13 Flint 36 3. Bright fritted glaze. Cone .02 Formula PbO .25 } ZnO .15 } Al_{2}O_{3} .15 } CaO .30 } } SiO_{2} 2.35 Na_{2}O .20 } B_{2}O_{3} .30 } K_{2}O .10 } Mix: Fritt Glaze Borax 114 Fritt 117 Whiting 60 White Lead 64 Soda Ash 10 Zinc Oxide 12 Spar 56 Spar 28 Flint 78 Kaolin 13 Flint 60 Grind as before. 4. Matt glaze. Cone .02 Formula PbO .50 } CaO .30 } Al_{2}O_{3} .34 SiO_{2} 1.48 K_{2}O .20 } Mix: White Lead 129 Whiting 30 Spar 111 Calcined Kaolin 22 Kaolin 11 5. Matt glaze. Cone 7 Formula CaO .75 } Al_{2}O_{3} .55 SiO_{2} 2.10 K_{2}O .25 } Mix: Feldspar 139 Whiting 75 Calcined Kaolin 55 Kaolin 13 For colored glazes add to any of the above: Blue: Cobalt Oxide 3 parts Slate blue: Cobalt Oxide 3 parts Nickel Oxide 1 part Warm blue: Cobalt Oxide 2 parts Iron Oxide 1 part Green: Copper Oxide 8 parts Blue green: Copper Oxide 8 parts Cobalt Oxide 1 part Cool green: Copper Oxide 8 parts Cobalt Oxide 1 part Nickel Oxide 2 parts Olive green: Copper Oxide 6 parts Iron Oxide 4 parts Orange brown: Iron Oxide 8 parts Red brown: Iron Oxide 8 parts Chrome Oxide 1 part Zinc Oxide 3 parts Yellow: Uranium Oxide 3 parts The coloring oxides should be weighed out and ground with the glaze. Any of the colors may be mixed together in order to modify the hue obtained or the amount of each coloring oxide may be varied to give a stronger or weaker value. Opaque tin enamel. Cone .02 Formula PbO .40 } CaO .25 } { SiO_{2} 1.75 K_{2}O .20 } Al_{2}O_{3} .25 { SnO_{2} .30 ZnO .15 } Mixture: White Lead 103 Whiting 25 Feldspar 111 Zinc Oxide 12 Kaolin 13 Flint 27 Tin Oxide 45 Grind, with one-half pint of water, for 45 minutes. PART V: THE DEFECTS OF GLAZES While it may chance that body and glaze and fire are so adjusted that faults do not develop, this state of things is rare. Besides, it is always possible that an occasional trouble may arise, hence it will be well to recount a few of the commonest defects with the method of cure. A cure is not necessarily specific. There may be a complication of causes but the remedy indicates the line along which relief will be found. 1. Crazing. Fine cracks appear in the glaze but do not penetrate the body. There are many causes. The body may be underfired or overfired. In the former case the crazing does not always appear at once and it grows worse upon standing. In the latter case the glaze is found to be crazed when taken from the kiln and it does not extend even after long standing. The glaze may be underfired. In this case the lines of the crack are broken and irregular, one often changing its direction without meeting another crack. In all these cases the remedy is obvious. Crazing also occurs when both body and glaze are correctly fired but there is an inherent disagreement in expansion. In such a case a little flint added either to the body or to the glaze will tend to cure the trouble but it must be remembered that the addition of flint to the glaze is apt to render it less fusible and therefore while one craze may be cured another may be caused. The addition of flint to the body is the simplest remedy. 2. Shivering or peeling. This is the reverse of crazing and is caused by the glaze being too large for the body. It almost always appears immediately the ware is cooled. The symptoms are that edges or convex surfaces are pushed off and even the ware itself is shattered. The remedy is to decrease the flint in either body or glaze. 3. Blistering. Glazes, both bright and matt, are apt to develop blisters at times. These may be yet unbroken when the kiln is opened or they may have melted down to a small crater, a ring with a depression in the center. The cause of this fault is usually to be found in the body. All clays contain sulphur and when a clay is aged this develops an acid which rises to the surface of the ware when dried and causes a scum. The glaze attacks this sulphate scum and a gas is generated which boils out and causes the blisters. If old clay blisters and new clay does not it may be regarded as certain that this is the cause. A little barium carbonate added to the clay will help to effect a cure. About one per cent. is usually enough. Clay so treated, however, must not be used in plaster molds as the barium attacks the plaster. If the cause be not found in the clay it may exist in the glaze itself. Some glaze ingredients contain impurities in the form of sulphates and these will cause blisters. 4. The glaze flows, leaving bare places. It is too fluid, add a little clay and flint. 5. A matt glaze burns to a bright surface. Matt glazes must be used in a very thick coat. If too thin they will inevitably brighten. The fire may be too high. The fire may be "reducing," that is, with insufficient air. 6. The glaze crawls or rolls up in lumps. Notice whether the glaze is cracked before burning. If so it will surely crawl. Too fine grinding is usually the cause of this trouble. Too much clay in the glaze may cause it, or a too porous body. A body which is underfired will almost certainly cause the glaze to crawl. 7. Pinholes appear in the glaze when cool. Too rapid cooling is the cause. PART VI: ALKALINE GLAZES The glory of the Persian and Egyptian blue is too alluring for potters to withstand. Though the pursuit of this glory leads one into all kinds of disasters and failures, the avenues of research that it opens add unending fascination to the study. Even one beautiful glowing pot out of twenty or more efforts is a stimulating achievement though it should not be thought that this is the usual proportion. It is a continual source of astonishment that with a slight variation of glaze formula a positive green will swim into a vibrating blue. The addition or substitution of one substance or another in the glaze mix may be the key to an unexpected transformation and may give the potter a new palette of color. The clay body has a very positive effect on alkaline glaze both in its composition and its color. This is especially true under a transparent glaze where the effect is considerable since the color of the glaze would be modified by the red or buff clay showing through. If, therefore, the object of the potter is to obtain a brilliant "Persian" blue, a white clay body must be composed or a white _engobe_ applied over the buff or red clay to hide the color. The Persians and Egyptians used a coarse, sandy body high in silica and covered the roughness of the clay with a fine white _engobe_ on which they painted their decorations in various colors. The whole was finally covered with the transparent alkaline glaze. While the effect of colored clay under opaque glaze is less pronounced, it still makes sufficient difference to be considered. The word _engobe_ is French and refers to a thin coating of clay, also called a slip, laid over a colored body to change the color or over a coarse body to give a finer texture. The _engobe_ is usually composed of china clay, flint, and feldspar much as a white earthenware body is constituted but with a larger content of flint. Ball clay may also be used but the color is not so white. The mixture of porcelain given on page forty will make an _engobe_ suitable for many clay bodies. If it should crack on drying more flint should be added. An _engobe_ must, of course, be put upon the unburned or green clay ware and this should be leather hard, not dry. The body with the _engobe_ may be burned before glazing or the glaze may be put upon the unburned ware and the whole subjected to one fire only. The ingredients in alkaline glazes are soda-ash, whiting, feldspar, flint and oxide of tin. The following is an example of a fritted glaze: Na_{2}O .60 } K_{2}O .10 } Al_{2}O_{3} .10 SiO_{2} 1.30 CaO .30 } Soda Ash 64 Whiting 30 Feldspar 56 Flint 42 The entire batch is fritted and ground in a ball mill with the usual amount of water for fritt grinding, adding a tablespoonful of gum tragacanth mucilage to the batch after it is sieved. The glaze should be the consistency of heavy cream when used. It is also possible to use an alkaline glaze in the raw or unfritted state. This necessitates grinding by hand in a mortar, but great care must be taken to mix the dry ingredients thoroughly before adding water and to stir the glaze constantly while pouring in the water, otherwise the soda-ash will cake and harden and be very difficult to break up. A batch of glaze can be ground by hand in fifteen or twenty minutes if done vigorously. It is then put through a 120-mesh sieve. The consistency is of importance. If too much water has been added and the glaze has become thin, it cannot be used successfully and should be discarded. Unfritted alkaline glaze does not keep well when moist but the ingredients can be ground dry and kept ready to be moistened as needed. The following is an example of an unfritted alkaline glaze: Na_{2}O .59 } CaO .21 } Al_{2}O_{3} .20 SiO_{2} 1.6 K_{2}O .20 } Soda Ash 62 Whiting 21 Feldspar 111 Flint 24 For color add the following oxides to a batch. 1. Egyptian blue, opaque--from 5 to 8 grams of black oxide of copper--16 grams of oxide of tin. 2. Persian blue, opaque--from 8 to 10 grams of black oxide of copper--16 grams of oxide of tin. 3. Sapphire blue--1 gram black oxide of cobalt. 4. Aubergine--9 grams black oxide of manganese. The clear glaze without any coloring oxide can be used over any of the colored glazes. This is sometimes necessary when the colored glaze contains such a large proportion of coloring oxide as to show black on the surface. The application of alkaline glaze is very important. Any of the three methods of pouring, dipping, and brushing can be employed. Brushing seems to give the best results but the glaze must be put on thick, in two or three coats, to give quality. The firing is interesting and important because of the varied effects it develops from the same formula. The range of temperature is great, varying from cone .05 to 1, developing the alkaline glaze according to the result desired. If the biscuit is soft fired the color will be more intense; if hard fired, the color will be much lighter in value with a high sheen on the surface. An unfritted alkaline glaze burned to .05 develops a soft matt finish. Where the color of a transparent Persian blue comes out olive green, too little glaze has been used on the piece or the buff of the clay has modified the color. Bubbles mean undeveloped glaze or sulphur in the clay or fuel. Black scum shows an excess of copper in the batch, or reduction in the fire. Sand paper surface proves too low firing or too thin a glaze. If one desires to reproduce the underglaze Persian decoration the black outlines may be drawn with a black underglaze color mixed with clay. A little mucilage must be added to secure smooth working. The turquoise blue is copper oxide, the dark blue cobalt, and the purple manganese. The oxides must be diluted with white clay and used rather thin. The Rhodian red is a finely ground red burning clay mixed with a little flint. This red must be laid on quite thickly. It will probably be found necessary to fire the painted decoration to about cone .03 before glazing. The glaze may be either quite clear or slightly tinted. Another effect may be produced by using the black outline alone under a peacock blue or turquoise glaze. A great many modifications and additions to this subject will suggest themselves to the potter as he works, and a continual study of the masterpieces of the Persians in the museums will prove the greatest inspiration. CHAPTER XVI: DECORATION The necessity for some kind of decoration upon the clay will always be a point of difference amongst artists. Some prefer the simple form with a glaze treatment only, others consider that the surface should be broken up by design. The question will not be debated here. The aim of this hand-book is instruction and the individuality of the worker is to be encouraged. Directions for executing the different treatments do not imply that these elaborations are advocated. That must be left to the inspiration of the worker. Decorations may be applied upon the soft clay by incising, inlaying and embossing; upon the dry clay or upon the burned pottery in color under the glaze or with no glaze at all; in the glaze by the use of colors or colored glazes; or over the glaze with colors and enamels. Each of these methods possesses special features. Each has its own possibilities and limitations and these should be mastered by the craftsman. As in the production of form a well-planned design should be prepared. The first sketch should be made on paper or on a slab of clay but the fitting and final arrangement are best made on the piece itself. Incising consists in the excavation of a shallow trench or trough on the surface of the clay. The vase or jar having been finished should be kept in a damp place so that the clay does not dry out completely. The design may be made in India ink with a brush. A steel tool with a narrow chisel end is used for cutting and care must be taken that the clay is in such a condition of moisture as will admit of a clean trench being dug without any rough or broken edges. The bottom of the trench need not be very smooth but the edges should be sharp and the lines well defined. At the same time a mechanical hardness of finish is to be avoided. The plastic nature of the clay should be kept in mind and every surface, though decided in character, should be soft and expressive. This result can be secured by working over the cutting with a moist camel-hair brush. The work must not be mopped so as to leave a woolly effect, but a little sympathetic penciling will remove the hard lines of the tool. There are two possible developments of incised work. The details of the design may be excavated or the background may be cut out leaving the drawing in relief. In modeling embossments the piece should be a little softer than for incising. It is important that in any clay work attached to a clay body the same amount of moisture should be present in both parts. This is not entirely possible in modeling upon forms which have already been shaped, for if the form be as soft as modeling clay it will not bear to be handled, while if the clay were as hard as the form it could not be worked. A compromise is therefore necessary. The vase must be kept as soft as possible consistent with holding its shape and the clay must be as stiff as the working will allow. As little water as possible should be used and the modeling should not be brought to its full height at once. If the clay be laid on little by little there is much less chance of cracking. Low relief is sometimes produced by painting in slip but here even more care is necessary. The slip should be laid on with a brush in thin coats, each coat being allowed to stiffen before another is applied and the whole work being kept moist. An atomizer with clean water is useful in this regard. The work, being kept on a whirler or turntable, is sprayed now and then with water and thus prevented from becoming too hard. When the slip work has been raised to the desired height the surface is tooled over so as to remove the brush marks. This is the method which has been brought to such perfection by the French artists and by them named _pâte-sur-pâte_. Modeled work is generally carried out in the same clay as that of which the form is made and depends upon high relief for its effect. Slip painting is usually done in a different color and if a light-colored slip be used upon a dark clay, the latter is partially seen through the coating in the thinnest places. This fact is made use of to accentuate the shadow effects. In using one clay over another great care must be taken to insure that the fire shrinkage is the same. The white body already given, or indeed, any light colored clay, may be tinted by the addition of under-glaze colors. The dry color, if sifted very fine, may be added to the plastic clay by thorough kneading and wedging but it is better to work up the clay into a slip and to stir in the color. The tinted slip is then lawned two or three times and dried out on plaster or used in the slip state as the case may be. A trial should be made before any important work is undertaken, both to see that the color is right and to discover any discrepancy in shrinkage. If a clay shrinks too much, a little ground flint may be added. If it shrinks too little, a little ball clay will correct it. The tint produced by the color is apt to darken in the kiln but the general hue will be similar to that of the color used. For some classes of work a native red clay gives admirable results. It may be lightened by the use of kaolin and flint and darkened by adding burnt umber. These colors are more satisfactory than greens and blues in clay because the brown and red tones are natural, the others are artificial. If a good buff-burning clay be available, it forms the best possible foundation for color work. Burnt umber will darken it and red clay may be mixed with it, always having regard to the matter of shrinkage already mentioned. Very pleasing effects may be produced by inlaying one clay with another. The pattern or design is first cut out as described under incising and then the second clay is pressed, morsel by morsel, into the excavation. The surface is cleaned off level with the body of the piece and the whole may be either polished or glazed. A plastic clay can be polished when leather hard and the finish will remain after firing. Any tool of steel, boxwood or ivory will do the work but a good supply of patience is needed so that the whole surface may be uniformly treated. For color decoration upon the pottery, ordinary underglaze colors are used, either upon the unburned clay or upon the burned ware commonly called biscuit. For use upon the clay, the colors should be mixed in water, using a little molasses, sugar, glycerine or gum arabic to make the color flow easily from the brush. Before burning, a little glaze should be sprayed over the work with an atomizer. Any ordinary fusible glaze will do. It is diluted with a good deal of water as only the very thinnest coat is necessary. The spray should not be held long in one place or the water will flow and smear the color. If the piece be turned slowly around the clay will absorb the water as it is applied. If this spraying be not done the colors will be apt to rub off after burning. Under-glaze colors are not fusible and hence they come from the fire as dry powders. The work on the biscuit is much the same except that turpentine and fat oil constitute a better working medium. When dry the spray should be applied as before. CHAPTER XVII: THE FIRE Kilns and burning form the pivot upon which the art of the potter turns. M. Doat has said, "A potter can no more express himself without his kiln than can a violinist without his violin," and yet there are some who try to make out by sending their work to some nearby pottery to be burned. Let it be at once understood that he who finds it impossible to procure and manage a kiln had best take to some other craft. Kilns are of two types, open and muffle. In the open kiln the flames pass through the firing chamber and the ware may be exposed to their action, as in stoneware and brick; or it may be enclosed in the fire-clay cases, called saggers, as in the many forms of pottery, dishes or faience. The muffle kiln is a closed chamber which is surrounded by flames but which is not entered by them. These kilns are used in the manufacture of terra cotta and heavy enamel wares, and the portable kilns made for studio use are of this type. There are certain advantages to be gained in the use of either type of kiln but inasmuch as the open kiln involves the use of saggers and as, moreover, it must be properly constructed of fire-brick by a skilled mason, it will be best to consider only the portable studio kiln.[M] [M] These kilns are made in several sizes by the H. J. Caulkins Company, Detroit, Mich. It must not be expected that any kiln will give perfect satisfaction. Neither built kiln nor portable kiln will do this, but either may be relied upon to do excellent work in the hands of those who will take trouble. A kiln of the proper size having been purchased, it must be carefully installed. A good chimney is an absolute necessity and if one can be built on purpose it will be best. It should be at least twenty-five feet high with the bottom lined with fire-brick to a height of six or eight feet. The portable kiln is set on iron legs which raise it about one foot from the floor. This is not enough for easy work and a platform of brick or stone, ten inches high, should be prepared. This will greatly simplify the observation and management of the burners which are beneath the kiln, and if it should make the inside of the muffle hard to reach, it is easier to stand on a box to attend to the kiln than it is to go on one's knees to the burner. The kiln room should have a cement floor and should be both well drained and well ventilated. At the window there should be a stout bench where the work of preparation may be done and at a convenient spot there should be shelves for stilts, cones, wash, stopping and all the minor accessories of burning. If there is room for a barrel of oil it will be a convenience, and if the room be fire-proof the insurance company will not object. The kiln having arrived it is mounted on the platform and the asbestos-lined pipe is securely connected with the chimney. The inside of the muffle is examined with care to see that no part has been jarred in transit. The reservoir cans are filled with oil and a slow fire is started. This should be allowed to burn very gently for an hour or two in order to thoroughly dry out and season the kiln. It is a good plan to make up a wash of equal parts of kaolin and flint and to brush this all over the inside of the kiln. It should not be put on so thick as to shell off from the walls but at the bottom a good coating may be laid. This protects the walls of the kiln from the attacks of glaze and will make them last longer. In order to fill the kiln economically a number of props and bats must be provided. Some of these are sent out with the kiln but one is always needing odd sizes and extra pieces. The props are simply legs of burned clay; they are of any height desired and should be thick enough to stand alone. The bats are slabs of burned clay and they rest on the props to form shelves. The bats must be thick enough to bear the weight of any pieces which they may be called upon to support, but they need not be very large as two or more may be used to bridge the width and length of the kiln. Bats and props are best made of sagger clay to which has been added about one-third of crushed fire-brick. Broken bats serve well for this after the first supply has been secured. This crushed burned clay, called grog, has a very important influence upon wares which have to be heated again and again. The size used should be about what will pass through a 16-mesh sieve, and if the dust be sifted out through a 48-mesh sieve, the resulting ware will be stronger. That is, only the grog which passes a 16 sieve but lies upon a 48 sieve should be used. The relative proportions of clay and grog in the mix will depend somewhat upon the nature of the clay. Three parts of clay to two of grog by measure will be about right. The first charging of the kiln should be with pieces of no great importance. The temperature in different parts must be carefully ascertained. In order to do this a number of pyrometric cones[N] are prepared in groups of three. [N] The pyrometric cones are fusible pyramids for testing heat. They are made by Prof. Edward Orton, Jr., Columbus, Ohio. Let us suppose that the work is intended to be carried out at a temperature of Cone No. 01. The numbers run both ways from this. The higher or less fusible cones are, 1, 2, 3, 4, etc., up to 36, and the more fusible numbers are 02, 03, etc., down to 022. If the firing is to be to Cone 01, numbers 02, 01 and 1 are selected and set upright in a small strip of soft clay. Eight or ten of these groups of three cones are to be prepared for the first firing, so as to test the kiln, one group is placed in each corner, at the bottom, and another in each corner on a shelf, which is arranged opposite the spy-hole in the door. In the middle of this, where it can be well seen through the hole, one of the groups of cones is placed. They must be set so that all three cones are visible as the kiln is being fired. The kiln is now filled up on both levels with pieces of pottery. To burn an empty kiln is not a reliable test. On the first occasion the fire should be started in the morning because no one can tell just how long the burn will take. When this time is ascertained it is best to start the fire so that the kiln will be finished by early evening. The cooling then takes place at night and there is no temptation to open the door too soon. The fire is started slowly and the flow of oil is gradually increased as the muffle begins to glow. The work here needs practice, nerve and judgment. A good deal of smoke will be seen at the chimney at first but this should disappear as the kiln grows red. If the fire be urged too strongly at the beginning fuel will be consumed to no purpose, the only result being the choking of the flues with carbon. As the red becomes visible through the spy-hole, more oil may be supplied, but notice must be taken that the smoke at the chimney does not increase. The ideal firing is where there is no smoke but this cannot be reached until the kiln is hot enough to cause the smoke to burn. Persons who have burned kilns for overglaze work will find the method of burning pottery very different. Instead of a fire brought as rapidly as possible to the finishing point, there must now be a slow soaking burn in which the heat shall have time to saturate the ware. The cones in front of the spy-hole must be observed from time to time and presently as the kiln reaches a bright cherry red, number 02 will begin to bend at the tip and will gradually arch over until the point touches the shelf upon which the cones stand. By this time number 01 will have begun to bend and when the point of this has touched the shelf, the firing is over and the oil is shut off. It requires some resolution to leave a kiln until morning but it is conducive to early rising anyway. The kiln need not be quite cold but it will help the kiln itself to wear better and the pottery will be better if nothing is done until everything can be handled without gloves. The cones are now taken out and a diagram is made of each level with the bend of each cone accurately drawn. This diagram should be mounted and hung on the wall for reference. It is not well to trust to memory. It will probably be found, in the type of kiln we are discussing, that the cones on the bottom have bent further than those on the shelf. That is, the bottom is somewhat the hotter. The variation in the kiln is not necessarily a disadvantage. It may be utilized in burning wares of different kinds. For example, if the bottom prove much the hotter, the biscuit ware may be placed below and the glazed pieces on the shelf. In such case the shelf itself should be washed with a good coating of clay and flint in order to protect it from casual drops of glaze. If a number of small pieces are being made, more than one shelf should be set up. The legs may be just a little taller than the tallest of the small pieces, but the art of placing or filling a kiln economically consists in making selection of pieces which fit well together both as regards height and shape. Thus, pieces which are large at the base may be dovetailed in with others of which the base is smaller than the upper part. In the case of clay ware the pieces may be set close together or even piled one upon another. There is no danger of sticking unless the ware is burned to complete vitrification. The glazed pieces must not, of course, touch each other. It will be seen, from these instructions, that there should be a good assortment of wares from which to select. Economical firing cannot be managed if a burn be attempted whenever a piece is ready, and patience must be exercised so as to fill the kiln to advantage. It is important that anyone attempting to burn a kiln should have some understanding of the phenomena of combustion. Many things occur in the firing which, without such an understanding, are not easily explained but which become perfectly clear when considered in the light of simple chemical science. Combustion means oxidation or a combination between the elements of the fuel, principally carbon and hydrogen, and the oxygen of the air. This combination is a chemical action and as it proceeds heat is liberated. With a given amount of a specific fuel and a given amount of air there is always the same amount of heat, but the rate at which this heat is given off varies with the time occupied in the operation. Heat may be generated slowly which means a low temperature, or the same volume of heat may be generated rapidly, occupying a much shorter time and developing a higher temperature. From these statements it will be seen that there is a difference between heat and temperature; heat means volume, temperature means intensity. Thus the temperature derivable from a given amount of fuel depends upon the rapidity with which it is burned. Combustion may be either complete or incomplete. In the former case enough air is supplied to oxidize all the fuel with, usually, some excess. The contents of the kiln are then bathed in the heated oxygen and the condition of the burning is called oxidizing. When the combustion is incomplete, on the other hand, there is a deficiency of oxygen. The kiln is charged with hot carbonaceous gases and smoke, and these, being hungry for oxygen, will abstract it from any substance which may be present. This condition is called reducing because the compounds which exist in clay or glaze are deprived of oxygen and thus reduced to a lower state of oxidation. In burning a kiln one should be able to produce either of these conditions at will because there are certain wares which require one or the other in order to secure the best results. To put the matter in a nutshell, oxidizing conditions are induced by a strong draft and open flues, reducing conditions are obtained by closing the air inlets and using a liberal amount of fuel. CHAPTER XVIII: HIGH-TEMPERATURE WARES The subject of "Grand Feu Ceramics" has been so ably developed by M. Taxile Doat in his admirable treatise[P] that it will be unnecessary to go deeply into the matter, but in order that the reader may be aware of what is involved, some description of the technique will be given. [P] Keramic Studio Publishing Co., Syracuse, N. Y. Hard-fired wares are divided into two classes, porcelain and stoneware. The latter is called by the French, "Grès," an abbreviation of the name "Grès de Flandres," the stoneware made in the low countries in the sixteenth century. Both these wares are, technically, once fired, that is, the body and glaze come to maturity at one and the same burning. The biscuit ware is often given a low burn at first in order to facilitate handling, but this leaves the body very porous and is in no sense a maturing fire. The glaze is laid upon this porous ware, or upon the unburned clay if preferred, and then comes the high fire or "Grand Feu" of the French. A mix for a porcelain body has already been given but if the ceramist means seriously to attack the porcelain problem he will have to do some experimental work for himself. The Georgia kaolin mentioned in the recipe on page 40 is a good, plastic clay but it is slightly off color. It may be necessary to improve the color by the use, in part, of another kaolin such as the Harris clay from North Carolina.[Q] [Q] The Harris Kaolin Company, Dillsboro, N. C. Furthermore, in the preparation of a fine porcelain it is necessary to grind the whole mix upon a mill. The mill used for glaze grinding will answer every purpose and care must be taken that the grinding, while carried far enough, be not too long continued. A certain amount of fine grit in the body mass is necessary but only by constant practice can the right point be reached. In making these experiments each step should be faithfully noted in a handy book. The amount of water to a given weight of clay and the duration of the grinding should be accurately observed and written down. It is most unwise to trust to memory. The process of casting may be used for porcelain as already described, but the very best of workmanship is necessary. The hard fire to which the porcelain is subjected reveals every error which has occurred in the making. The same thing applies to wheel work. Not only is great skill required in order to shape the tender porcelain clay on the wheel but the very essence of the porcelain is its lightness, to produce which by craftsmanship a long and arduous course of training must be endured. Stoneware is free from many of these difficulties and, consequently one who attempts the conquest of high-temperature wares is advised to begin with this. Stoneware clay need not be a mixture. There are many clays which can be used for the manufacture of grès with no more preparation than that laid down for common clays.[R] It sometimes happens that a clay will need the addition of a small quantity of flint or spar but this does not amount to a difficulty. [R] Stoneware clays may be procured from The Western Stoneware Company, Monmouth, Ill.; H. C. Perrine and Sons, South Amboy, N. J. Stoneware does not present the same manufacturing difficulties as are found in porcelain. The clay is quite plastic and can be easily shaped on the wheel; casting is scarcely a suitable process for this ware. The essence of stoneware is strength and virility, just as that of porcelain is lightness and grace. Each ware has forms suited to itself and it is a mistake to depart from these essential characteristics. After shaping and drying the technical manipulation of both wares proceeds along the usual lines. The first fire is at a very low temperature. The melting point of silver (cone 010) is enough in nearly every case. This leaves the ware in a soft and porous condition but hard enough to resist the action of water. The process of glazing has already been described but the composition of the proper glazes differs from that of low temperature glazes. Porcelain is always burned in a reducing fire; stoneware may be burned either reducing or oxidizing. The temperature at which the glaze is burned is very high, it must be, in fact, the maturing point of the body itself. The simplest form of porcelain glaze is that represented by the formula-- K_{2}O .3 } CaO .7 } Al_{2}O_{3} .5 SiO_{2} 4.0 Which is carried out in the following mixture: Feldspar 167 Whiting 70 Kaolin 52 Flint 108 ---- The glaze is ground for use. The same glaze will also serve for stoneware but it will burn to a brilliant surface whereas stoneware is better when finished with a matt texture. The following is a stoneware matt glaze: K_{2}O .3 } CaO .7 } Al_{2}O_{3} .7 SiO_{2} 2.6 Of which formula the mixture is-- Feldspar 167 Whiting 70 Calcined Kaolin 66 Raw Kaolin 26 ---- The porcelain glaze is at its best when uncolored. The matt glaze will be more interesting when used as a colored coating. The following are a few suggestions for colored matt stoneware glazes. To the glaze batch, 329 parts, add: For blue: Cobalt Oxide 2 parts Nickel Oxide 1 part Ground Rutile 10 parts For brown: Iron Oxide 6 parts Nickel Oxide 3 parts Ground Rutile 10 parts For green: Chrome Oxide 2 parts Cobalt Oxide 1 part Iron Oxide 4 parts For dark red: Iron Oxide 10 parts Chrome Oxide 2 parts Zinc Oxide 6 parts Rutile has not before been mentioned. It is a crude oxide of titanium and is exceedingly useful in high temperature work for producing odd, mossy and crystalline effects. These mixtures make no pretense to be complete, they are given as suggestions only because if the artist-potter is to be successful he must be prepared to compound glazes which are the expression of his own individuality. For burning high-temperature wares the kilns already described may be used but upon purchasing it should be stipulated that the kiln is to stand burning up to cone 11 or 12. Successful porcelain can be made at cone 10 but better results are secured at cone 12, though, of course, the wear upon the kiln is proportionately greater. Stoneware requires a burn of about cone 9, higher or lower according to the clay used but fine results must not be expected below cone 7 nor is it necessary to go higher than cone 10. CHAPTER XIX: CLAY-WORKING FOR CHILDREN One of the modern developments of clay-working is the use of it in elementary and high schools as a branch of manual training. In this, clay meets the most exacting needs of the work for it affords a perfect means of self-expression. Other arts interpose between the pupil and his material a series of tools or appliances, more or less elaborate, which constitute a barrier to the personal touch. Clay presents no such obstacles. The ten fingers are all the tools that are necessary at the beginning and, consequently, the personal equation in clay-working is remarkably high. In the kindergarten the children take to clay work as little ducks to water and the interest is never lost. In this way, clay, instead of adding to the labors of a teacher already overburdened by a plethora of subjects, constitutes a real relief. The work is so interesting that it moves along of itself and all that is needed is intelligent direction. It is, of course, necessary that anyone attempting to teach clay-working to children should have a knowledge of methods and principles. The essence of power, especially in teaching, is reserve, but there is great danger in expecting too much from small heads and hands. In the early exercises the skill of the teacher should even be employed to conceal her art. It is a mistake to place before elementary pupils work which is far beyond their reach. Let the teacher make before the class something which they themselves can do if they try and they will be encouraged to greater effort. A small cylinder is a suitable beginning exercise for several reasons. The form is definite and the result may therefore be easily criticized by the children themselves, the size of the piece may be readily adapted to the small fingers and the simplicity of line enables the attention to be concentrated upon the manipulation of the clay. This cylindrical form may be made more interesting by the addition of little feet or handles; by a simple line border incised along the upper edge; or by dividing the surface into well-spaced panels. The planning of the cylinder itself is a good exercise in rectangle proportion. In order to enable the pupils to turn their work from side to side each one should be provided with a piece of paper or cardboard the size of the base of the pottery. The building is started upon this and, managed in such a way, the clay does not stick to the table. When the idea of pottery building, either by coils or by pieces welded together, has been grasped, the children should be taught to think in the solid. There is almost always a difficulty in making children see that an outline drawing and a solid form may be alike in meaning. The teacher should draw upon the blackboard a simple jar in elevation, the plan, of course, will be a circle. The same thing is then made in clay by both teacher and children and the results are compared with the drawing. This will lead to the designing of the forms in outline by the children themselves. These designs should be made the exact size of the proposed pottery and if the outline be carefully cut out the line of the paper may be applied to the work as a template. By such means the children are led to produce accurate lines in the clay and control over the material is secured. There is always a temptation, when the clay sags or loses shape, to diverge from the original idea and to allow the material to shape itself. This inevitably leads to slovenly work and should be resisted from the first. The paper template helps to correct such an impulse and the pupil presently finds that the clay can be successfully controlled if enough trouble be taken. There is much interest too in the cutting of pottery forms from folded paper. A number of these forms may be pinned on a screen and the children led to select the best in line and proportion. Too much emphasis cannot be laid on the necessity for showing the children fine examples of pottery, both ancient and modern. The more primitive types, where the form and the decoration are so perfectly adapted to each other and to the material, are full of inspiration for the child potter as well as for the adult. When one is fortunate enough to be near a museum, many illustrations will be found, but good photographs or drawings are available for almost everyone. Constant comparison and the exercise of choice will lead to a development of taste, which must affect the child whether he later becomes a producer or a consumer. A flower holder is a good problem. It is a solid piece of clay two or three inches in diameter and an inch thick. This may be round or square in form and may have simple modeled decoration added to it. Quarter inch holes are pierced at regular intervals, in fact, they themselves should form part of the design. For the older children a shallow bowl of good line with a flower holder to fit is an interesting problem. Other good problems, which may be made more or less difficult according to the grade in which they are given, are rose jars, bread and milk bowls, incense burners, cylindrical jars, square fern dishes, candlesticks and small lamp bases. When working out decoration for pottery forms, it is well to have the children make their designs with the modeling tool upon the clay itself. If a piece of soft clay be rolled out flat upon the table it affords the best possible medium for making clay designs. The pupil is at once put in touch with the possibilities and limitations of the material. A drawing made upon paper may have to be entirely changed before it is suitable for use on clay. The soft surface can be smoothed over as often as necessary and a new sketch made until a design is approved for application to the pottery itself. In the chapter on decoration will be found suggestions for clay treatment. The making of tiles affords an interesting application of the principles of design, but the instructions in the chapter on tile should be followed in order to insure a workman-like product. If it is possible to use plaster, the making of a decorated tile from which a mold can be made and other tiles pressed is a good problem. Animal forms lend themselves to the decoration of such tiles and are always interesting to children. While these chapters are especially devoted to ceramics in the sense of burned and glazed pottery a few words upon modeling as related to school work may be added here. Imitative modeling from cast or copy with its development of animal and figure modeling, both from life and from memory, is valuable in the acquirement of the power of manipulation and control as well as in the cultivation of observation, imagination and memory. In the best regulated schools the work of the grades is often correlated in the study of some phase of human life. Facts are grouped around some epoch or event in history or some country or clime in geography. The children take up the clay while their minds are full of the current subject and nothing more natural than that they should illustrate the story by models. Such work is to be thoroughly commended as truly educational, though it does not fall strictly within the field of pottery and a few suggestions may therefore be in order. The modeling of animals or people for the sand table is full of interest for the younger children. Such stories as "The Three Bears," "Chicken Little" and "The Little Red Hen" immediately suggest themselves. For children of about the fourth grade "Alice in Wonderland" offers a most fascinating array of models. "The White Rabbit," "The Duchess," "The Mock Turtle," "The Mad Hatter," grotesques of all sorts, seem a natural outcome of this illustration work and the wise teacher will see the possibility for developing the imagination in the modeling of mythical creatures, such as dragons and gnomes, and in the personification of the elements. There is also an unlimited fund of material in the tales of knighthood and of fairyland. With the older children, simple principles of design and composition should be suggested. A paper weight is an interesting problem demanding the adaptation of form to space. Many of these things may be modeled in clay, dried and painted with water color or one of the patent modeling clays which set like cement may be used. If no supports have been left in the model it may be fired when thoroughly dry. Some of the best projects for sand table work involving modeling are Eskimo Life, Indian Life, Farm Life, The Circus, and Fairy Tales. Generally a suggestion is all that is necessary to call forth the most original conceptions and once started the children will soon far outstrip the teacher. INDEX A Alhambra Vase, 16 Armenian Bole, 15 B Ball-Clay, Tennessee, 40 Bases for Glaze, 143 Berlin Porcelain, 28 Bisilicate Glaze, 145, 146 Black Surfaced Ware, 13 Blistering of Glazes, 166 Building, Clay for, 69 Building, Faults in, 72 Building, Methods of, 70, 71 Built Pottery, 10, 68 Burning Tiles, 139 C Case for Mold-making, 58 Casting, 129 Casting, Slip for, 129 Castor Ware, 13 Children, Pottery for, 194 Chinese Porcelain, 23 Clay, Colored, 36 Clay, Crude, 9, 37 Clay, Decoration in, 173 Clay, for Building, 69 Clay, for Tiles, 134 Clay, Preparation of, 37 Colored Glazes, 24, 143, 163 Colors, Underglaze, 25, 143, 177 Combustion, 186, 187 Cones, Pyrometric, 182 Copenhagen Porcelain, 27 Crawling of Glazes, 166 Crazing of Glazes, 165 Cups and Saucers, 124 D Decoration, 173 Decoration of Tiles, 137 Defects of Glazes, 164 Devitrification, 152 E Earthenware, Mixture for, 40 Engobe Ware, Oriental, 15 F Famille Rose, 24, 26 Famille Verte, 24, 26 Feet for Vases, 105 Firing the Kiln, 179 Fitness in Design, 3, 4, 7 Flowing of Glazes, 145, 166 Form and Weight, 7 Fritt for Glaze, 158 Fritting Furnace, 159 G Glaze, Bases for, 148 Glaze, Bisilicate, 144, 145 Glaze, Calculation of, 150 Glaze, Fritt for, 158 Glaze, Pinholes in, 167 Glaze, Porcelain, 191 Glaze, Recipes, 160 Glaze, Stoneware, 191, 192 Glazes, Blistering of, 166 Glazes, Clear, 141, 161 Glazes, Colored, 143, 163, 192 Glazes, Crawling of, 166 Glazes, Crazing of, 165 Glazes, Defects of, 164 Glazes, Flowing of, 145, 166 Glazes, Grinding, 151, 155 Glazes, Ingredients for, 142, 143 Glazes, Matt, 152, 191 Glazes, Nature of, 141 Glazing, 140 Glazing Tiles, 137, 138 Grès de Flandres, 21 Gum Tragacanth, 156 H Hard Porcelain, 23, 189 High-temperature Wares, 188 I Ingredients for Glazes, 142, 143 J Jars for Storing Clay, 41 K Kiln, Firing the, 179 Kiln, Portable, 180 Kilns, 179 L Lawns, Silk, 41 Large Pieces, 107 M Matt Glazes, 152 Methods of Making Tiles, 135, 136 Molds for Plates, 62, 63 Molds for Vases, 52 O Oriental Engobe Ware, 15 Ox-blood Red, 24, 26 Oxidizing Fire, 187 Oxygen Ratio, 145 P Pâte-sur-pâte, 14, 175 Pieces, Large, 107 Pinholes in Glaze, 167 Plaster-of-Paris, 45 Plaster Dishes, 46, 47 Plaster Head for Wheel, 65, 78 Plaster, Setting of, 45 Porcelain, Berlin, 28 Porcelain, Copenhagen, 27 Porcelain Glaze, 191 Porcelain, Hard, 23, 189 Porcelain, Mixture for, 40 Porcelain, Sevres, 25 Potter's Wheel, 74 Pottery, Built, 9, 68 Pottery, for Children, 194 Pottery, White-coated, 14, 168 Props and Bats for Kiln, 182 Pyrometric Cones, 182 R Recipes for Glazes, 160 Reducing Fire, 187 S Salt-glazing, 21 Saucers, Cups and, 124 Shivering of Glazes, 165 Size, Mold-makers', 44 Slip, 38, 39, 129 Slip for Casting, 129 Slip-painting, 175 Stoneware, 21, 188, 190 Stoneware Glaze, 191 T Tennessee Ball-clay, 40 Tiles, 133 Tiles, Burning of, 139 Tiles, Clay for, 134 Tiles, Decoration of, 137 Tiles, Glazing, 137, 138 Throwing, 77 Tin Enamel, 164 Tragacanth, Gum, 156 Turning Tools, 100 U Underglaze Colors, 143, 177 V Vase Forms, Turning, 49-52 Vases, Feet for, 105 Vases, Molds for, 52 W Weight and Form, 7 White-coated Pottery, 14, 168 [advertisement] Books for the Craftsman ¶ We can always supply any book on the Manual Arts--whether it is issued by us or by any other publisher. ¶ Our stock of these books is complete and our facilities for filling your orders promptly and carefully are unsurpassed. Send your inquiries to us. ¶ A request will bring our various catalogs. D. VAN NOSTRAND CO., INC. 8 Warren Street New York City 
7803	----	by Al Haines. [Illustration: "Sugar it is, then!"] The Story of Sugar BY SARA WARE BASSETT Author of "The Story of Lumber" "The Story of Wool" "The Story of Leather" "The Story of Glass" ILLUSTRATED BY C. P. GRAY _To my cousin_ _William Pittman Huxley_ _this book is affectionately inscribed_ It gives me much pleasure to acknowledge the courtesy of the American Sugar Refining Company, and also the kindness of Senator Truman G. Palmer, of Washington, D. C. S. W. B. CONTENTS I. COLVERSHAM II. A NARROW ESCAPE III. SUGARING OFF IV. THE REFINERY V. VAN SPRINGS A SURPRISE VI. A FAMILY TANGLE VII. MR. CARLTON MAKES A WAGER AND WINS VIII. VAN MUTINIES IX. VAN'S GREAT DEED X. HOW VAN BORE HIS PUNISHMENT XI. THE BOYS MAKE A NEW ACQUAINTANCE XII. THE DAWN OF A NEW YEAR Illustrations "SUGAR IT IS, THEN!" "I DON'T REMEMBER THAT BIG ROCK" "I SHOULD THINK IT WOULD STICK TOGETHER" "IT IS NO EASY TASK" NO HORN HAD GIVEN WARNING "THESE TANKS ARE CONNECTED" THE STORY OF SUGAR CHAPTER I COLVERSHAM "Oh, say, Bobbie, quit that algebra and come on out! You've stuck at it a full hour already. What's the use of cramming any more? You'll get through the exam all right; you know you always do," protested Van Blake as he flipped a scrap of blotting paper across the study table at his roommate. Bob Carlton looked up from his book. "Perhaps you're right, Van," he replied, "but you see I can't be too sure on this stuff. Math isn't my strong point, and I simply must not fall down on it; if I should flunk it would break my father all up." "You flunk! I'd like to see you doing it." Van smiled derisively. "When you fall down on an exam the rest of us better give up. You know perfectly well you'll get by. You are always worrying your head off when there's no earthly need of it. Now look at me. If there is any worrying to be done I'm the one that ought to be doing it. Do I look fussed? You don't catch your uncle losing any sleep over his exams--and yet I generally manage to scrape along, too." "I know you do--you old eel!" Bob glanced admiringly at his friend. "I believe you just wriggle by on the strength of your grin." "Well, if you are such a believer in a grin why don't you cultivate one yourself and see how far it will carry you?" chuckled Van. "The trouble with you, Bobbie, is your conscience; you ought to be operated on for it. Why are you so afraid you won't get good marks all the time?" "I'm not afraid; but I'd be ashamed if I didn't," was the serious reply. "I promised my father that if he'd let me come to Colversham to school I'd do my best, and I mean to. It costs a pile of money for him to send me here, and it's only decent of me to hold up my end of the bargain." Van Cortlandt Blake stretched his arms and gazed thoughtfully down at the ruler he was twirling in his fingers. "Bobbie, you're a trump; I wish more fellows were like you. The difference between us is that while I perfectly agree with you I sit back and talk about it; you go ahead and do something. It's rotten of me not to work harder down here. I know my father is sore on it, and every time he writes I mean to take a brace and do better--honest I do, no kidding. But you know how it goes. Somebody wants me on the ball nine, or on the hockey team, or in the next play, and I say yes to every one of them. The first I know I haven't a minute to study and then I get ragged on the exams. "You are too popular for your own good, Van. No, I'm not throwing spinach, straight I'm not. What I mean is that everybody likes you. Why, there isn't a more popular boy in the school! That's why you get pulled into every sort of thing that's going. It's all right, too, only if you expect to study any you've got to rise up in your boots and take a stand. That's why I shut myself up and grind regularly part of every evening. I don't enjoy doing it, but it's the only way." Van rose and began to roam round the room uneasily. "Goodness knows, Bobbie, if one of us didn't grind neither of us would get anywhere. By the way, did you manage to dig out that Caesar for to-morrow? Fire away and give me the product of your mighty brain. I guess I can memorize the translation if you read it to me enough times." Bob did not reply. "Well?" "I don't think it is a straight thing for me to translate your Latin for you every day, Van," he said at last. "You ought not to ask me to do it." "I know it; it's mighty low down--I acknowledge that," answered Van frankly. "But what would you have me do? Flunk it? Come on. I'll get it myself next time." "That's what you always say, Van, but you never do." "But I tell you I will. This week I've been so rushed with the Glee Club rehearsals I couldn't do a thing. But you wait and view yours truly next week." Reluctantly Bob took up his Caesar and opened it. "That's a gentleman, Bobbie. Some time when you're drowning I'll throw a plank to you. I knew you'd save my life." "I do not approve of doing it at all," Bob observed, still searching for the place in the much worn brown text-book. "I've done about all your studying this term." "I own it, oh Benefactor. Are you not my brain--my intellectual machinery? Could I live a day without you?" Leaning across the table Van affectionately rumpled up Bob's tidy locks until every individual hair stood on end. "If it weren't for me you'd be dropped back into the next class--that's what would happen to you; and you deserve it, too." Van was silent. "I know it. I haven't put in an hour of solid work for a month, Bob I ought to be ashamed, and I am." He paused. "But there's no use jumping all over myself if I haven't," he resumed, shifting to a more sprightly tone. "I've said I was going to take a spurt soon and I mean it. I'll begin next week." "Why not start to-day?" There was a rap at the door. "Why not?" echoed Van, moving toward the door with evident relief. "Don't you see I can't? Somebody's always breaking in on my work. Here's somebody this very minute." He flung open the door. "Mail. A parcels-post package for you, Bob. I'll bet it's eats. Your mother's a corker at sending you things; I wish my mother sent me something now and then." "Well, it's a little different with you. Your family live so far out west they can't very well mail grub to you; but Mater is right here in New York, and of course as she's near by she'd be no sort of a mother if she didn't send me something beside this prison fare. Come on and see what it is this time." Bob loosened the string from the big box and began unwinding the wrappings. "Plum-cake!" he cried. "A dandy great loaf! And here's olives, and preserved ginger, and sweet chocolate. She's put in salted almonds, too; and look--here's a tin box of Hannah's molasses cookies, the kind I used to like when I was a kid. Isn't my mother a peach?" "She sure is; and she must think a lot of you," said Van slowly. "I wish my mother'd ever--" "Maybe if you pitched in a little harder here she'd feel--" "Oh, cut out the preaching, Bobbie," was the impatient retort. "I've had enough for one day." Bob did not speak, but tore open the letter that had come with the bundle. "Oh, listen to this, Van," he shouted excitedly. "Mother says they have decided to open the New Hampshire house for Easter. They're going up for my spring vacation and take in the sugaring off. What a lark! And listen to this. She writes: 'You'd better arrange to bring your roommate home with you for the holiday unless he has other plans.'" "Oh, I say!" "Could you go, Van?" Bob eyed his chum eagerly. "I don't see why I couldn't. I'm not going home to Colorado. It's too far. I was thinking of going to Boston with Ted Talbot, but I'd a good sight rather go batting with you, Bobbie, old man. It was fine of your mother to ask me. Where is the place?" "Our farm? It's in Allenville, New Hampshire, near Mount Monadnock. It used to be my grandfather's home, and after he died and we all moved to New York Father fixed it over and kept it so we could go there summers. I've never been up in the spring, though. It will be no end of fun." "I hope you do not call this weather spring," put in Van, sarcastically, pointing to the snow-buried hills outside. "Well, it is the middle of March, and it ought to be spring, if it isn't," answered Bob. "Just think! Only a week more of cramming; then the exams, and we're off. I'm awfully glad you can go." "You speak pretty cheerfully of the exams. I don't suppose you dread them much." Van lapsed into a moody silence, kicking the crumpled wrapping-paper into the fireplace. "You don't need to worry, Bob. But look at me. I'll be lucky if I squeak through at all. Of course I've never really flunked, but I've been so on the ragged edge of going under so many times that it's no fun." "Cheer up! You'll get through. Why, man alive, you've got to. Now come on and get at this Latin and afterward we'll pitch into the plum-cake." "What do you say we pitch into the cake first?" "No, sir. Not a bite of cake will you get until you have done your Caesar. Come on, Van, like a good kid, and have it over; then we'll eat and talk about Allenville." Once more Bob opened the book. "Here we are! You've got to do it, Van, and to-morrow you'll be glad that you did. Stop fooling with that paper and bring your chair round this side of the desk. Begin here: _Cum Caesar esset_--" Persistently Bob followed each line of the lesson down the page, translating and explaining as he went, and ungraciously Van Blake listened. The little brass clock on the mantelpiece ticked noisily, and the late afternoon sun that streamed in through the windows lighted into scarlet the crimson wall-paper and threw into prominence the posters tacked upon it. It was a cozy room with its deep rattan chairs and pillow-strewn couch. Snow-shoes, fencing foils, boxing-gloves, and tennis racquets littered the corners, and on every side a general air of boyish untidiness prevailed. Although the apartment was not, perhaps, as luxurious as a college room, it was nevertheless entirely comfortable, for the Colversham School boasted among its members not only boys of moderate means but the sons of some of the richest families in the country. It aimed to be a democratic institution, and in so far as this was possible it was; the school, however, was richly endowed and therefore its every appointment from its perfectly rolled tennis courts to its instructors and the Gothic architecture of its buildings was of the best. Van Cortlandt Blake, whose father was a western manufacturer, had by pure chance stumbled upon Bob Carlton the day the two had alighted from the train and stood helpless among the new boys on the station platform, awaiting the motor-car which was to meet them and carry them up to the school. Before the five mile ride was finished and the automobile had turned into the avenue of Colversham the boys had agreed to room together. Bob came from New York City. He was younger than Van, slender, dark, and very much in earnest; he might even have passed for a grind had it not been for his sense of humor and his love for skating and tennis. As it was he proved to be a master at hockey, as the school team soon discovered, and before he had been a week at Colversham his classmates also found that he was most loyal in his friendships and a lad of unusual generosity. Van Blake was of an entirely different type. Big, husky, happy-go-lucky--a poor student but a right jolly companion; a fellow who could pitch into any kind of sport and play an uncommonly good game at almost anything. More than that, he could rattle off ragtime untiringly and his nimble fingers could catch up on the piano any tune he heard whistled. What wonder he speedily became the idol of Colversham? He was a born leader, tactfully marshaling at will the boys who were his own age, and good-naturedly bullying those who were younger. To the school authorities he presented a problem. His influence was strong and, they felt, not always good; yet there was not a teacher on the premises who did not like him. Intellectually they were forced to own that he was demoralizing. He was, moreover, a disturber of the social order. But his pranks were, after all, pure mischief and never malicious or underhanded. With a boy like Bob Carlton as a roommate and drag anchor the principal argued he could not go far astray. And so the first year had passed without mishap, and already the second was nearing its close. The school board congratulated itself. Had the faculty known that for most of his scholarship, poor as it often was, Van Blake was indebted to the sheer will power of Bob Carlton they might have felt less sanguine. Day after day Bob had patiently tutored his big chum in order that he might contrive to scrape through his lessons. It was Bob who did the work and Van who serenely accepted the fruits of it--accepted it but too frequently with scant thanks and even with grumbling. Bob, however, doggedly kept at his self-imposed task. To-day's Latin translation was but an illustration of the daily program; Bob did the pioneering and Van came upon the field when the path was cleared of difficulties. And yet it was a glance of genuine affection that Bob cast at his friend stretched so comfortably in the big Morris chair with a pillow at his back. "There, you lazy villain, I think you'll do!" he declared at last. "Don't forget about the hostages in the second line; you seem pretty shaky on that. I guess, though, you'll pull through alive." "Bobbie, you're my guiding angel," returned the elder boy yawning. "When I make my pile and die rich I'm going to leave you all my money." "Great Hat! Hear him. Leave me your money! What do you suppose I'm going to be doing while you're rolling up your millions? I intend to be rich myself, thank you," retorted Bob, throwing down his book. "Now for the plum-cake! You deserve about half the loaf, old man, but I shan't give it to you, for it would make you sick as a dog, and then I'd have you to take care of. Oh, I say, listen a minute! Isn't that the crowd coming from the gym? Open the window and whistle to them. Tell 'em to pile up here for a feed. And get your muscle to work on this olive bottle, Van. I can't get the cork out." CHAPTER II A NARROW ESCAPE The dreaded examinations came and went and, as Van Blake expressed it, were passed with honor by Bobbie and with dishonor by himself. After the last one was over it was with a breath of relief that the two lads tossed pajamas and fresh linen into their suit-cases; collected snow-shoes and sweaters; and set out on their New Hampshire visit. It had been a late spring and therefore although the buds were swelling and a few pussy-willows venturing from their houses the country was still in the grip of winter; great drifts buried roadside and valley and continued to obstruct those highways where travel was infrequent. "There certainly is nothing very summerish about this New England weather of yours, Bob," remarked Van, as, on alighting from the train at Allenville, he buttoned closer his raccoon coat and stepped into the waiting sleigh which had come to meet them. "The State did not realize you were coming, old man; otherwise they would have had some weather especially prepared for your benefit," Bob replied, springing into the sleigh beside his chum. "My, but this is a jolly old pung! Hear it creak. I say," he leaned forward to address the driver, "where did my father get this heirloom, David?" "Law, Mr. Bob, this ain't your father's," David drawled. "He ain't got anything but wheeled vehicles in the barn, and not one of 'em will be a mite of use till April. I borrowed this turnout of the McMasters', who live a piece down the road; the foreman, you know. It was either this or a straight sledge, and we happened to be using the sledges collecting sap." "Are you sugaring off already?" questioned Bob with evident disappointment. "I understood Father to say we'd get here in time to be in on that." "Bless your soul, Mr. Bob, you'll see all you want of it," was David's quick answer. "There's gallons of sap that hasn't been boiled down yet. It's a great year for maple-sugar, a great year." "Are some years better than others?" Van inquired. "Yes, indeed. What you want to make the sap run is a good cold snap, followed by a thaw. That's just what we've been having. It's a prime combination." He jerked the reins impatiently. "Get up there, Admiral! He's the very worst horse to stop that ever was made. You see in summer he drags a hay-cart, and he has to keep halting for the hay to be piled on; then in the fall we use him for working on the road, and he has to wait while we pick up stones and spread gravel; in the spring he makes the rounds of the sugar orchard every morning and stands round on three legs while we empty the sap buckets into the cask on the sledge. Poor soul, he never seems to get going that he ain't hauled up. He's so used to it now that he'd rather stop than go, I reckon." David's prophecy appeared to be quite true, for the Admiral proved to be so loath to proceed that every few paces he would hesitate, turn his head, and seem to be inquiring where the hay, stones, or sap buckets were to-day. It was only David's repeated urging which kept him moving at all. In consequence it was dark before the boys caught sight of the "Pine Ridge" lights gleaming through the tangle of hemlock boughs that screened the drive, and saw the door of the hospitable old farmhouse swing open. "Well, I'll wager you're pretty hungry," a cheery voice called. "Hungry, Mother! We're starved--hollow down to our shoe-strings!" Swinging himself out upon the steps Bob bent and kissed his mother. "Mother, this is my roommate, Van Blake," he added. "I'm very glad to see you, Van," Mrs. Carlton said, putting both her hands into those of the big fellow who smiled down at her. "How strange it is that although you and Bob are such friends and he is continually talking and writing of you that you and I should never have met!" "I don't just know how it's happened, Mrs. Carlton," Van answered. "It seems as if the times you've been at the school to visit I've either been away or shut up in the infirmary with chicken-pox or something. I'm great at catching diseases, you know--I get everything that's going. Father says he thinks I can't bear to let anything get by me." He laughed boyishly. "Speaking of fathers, where's Dad, Mater?" "He stopped to put another log on the fire. Come in and see what a blaze we have ready for you." The two boys followed her into the hall, while David staggered at the rear of the procession with the luggage. Mr. Carlton came forward. "This is Van Blake, Father," Bob said, proudly introducing his chum. "I'm glad to see you, young man," Mr. Carlton responded. "Bob's friends will always find a welcome from us." "Thank you, sir." Mr. Carlton reflected a moment then asked abruptly: "I don't suppose you happen to be a connection of the Colorado Blakes." "I come from Colorado," replied Van quickly. "You're not one of the sugar Blakes; not Asa Blake's son." "Yes," cried Van. "Mr. Asa Blake is my father, and he is in the beet sugar business. Do you know him?" "I believe I've met him," Mr. Carlton admitted hurriedly, stooping to push the glowing back-log a little further forward. "Why, Father--" Bob was interrupted. "Come, boys," said Mrs. Carlton bustling in. "I guess you've warmed your fingers by this time. Bob, take Van up-stairs and tumble out of those fur coats as fast as ever you can so to be ready for dinner." The lads needed no second bidding. They were up-stairs and back in the dining-room in a twinkling, and so eagerly did they chatter of their plans for the morrow that hungry though they were they almost forgot to eat. "There are so many things to do that it is hard to decide where to begin," declared Bob. "Of course we want some coasting and some snow-shoeing; and we must climb Monadnock. Van says he hasn't seen a real mountain since he came East. Then we want to be on hand for the maple-sugar making. Why, ten days won't be half long enough to do everything we ought to do." His mother laughed. "You must have a good sleigh ride, too," she put in. "I draw the line on a sleigh ride if we have to go with that horse that brought us up from the station," announced Bob. "Me, too!" Van echoed. "It would take you the entire ten days to get anywhere and back if you went sleighing with the Admiral," said Mr. Carlton. Every one smiled. "I'd advise your seizing upon the first clear day for your Monadnock tramp," Mr. Carlton continued. "You'd better make sure of good weather when you get it. It won't make so much difference with your other plans; but for the mountain trip you must have a good day." "I do want Van to get the view from the top if he makes the climb," Bob answered. So the chat went merrily on. Yet despite the gaiety of the evening and Mr. Carlton's evident interest in the boys' holiday schemes Bob more than once caught his father furtively studying Van's profile. Obviously something either puzzled or annoyed him. There was, however, no want of cordiality in his hearty goodnight or in the zest with which he advocated that if the next morning proved to be unclouded the two lads better make certain of their mountain excursion. He even helped lay out the walk and offered many helpful suggestions. Bob's uneasiness lest his father should not like his chum vanished, and when he dropped into bed the last vague misgiving took flight, and he fell into a slumber so profound that morning came only too soon. It was David who, entering softly to start the fire in the bedroom fireplace, awakened Bob. He sat up and rubbed his eyes sleepily. "What sort of a day is it, David?" he questioned in a whisper that he might not arouse Van, who was lying motionless beside him. "It's a grand day, Mr. Bob. There ain't a cobweb in the sky." David tiptoed out and Bob nestled down once more beneath the blankets. It was fun to lie there watching the logs blaze up and see your breath rise on the chilly air; it was fun, too, to know that no gong would sound as it did at school and compel you to rush madly into your clothes lest you be late for breakfast and chapel, and receive a black mark in consequence. No, for ten delicious days there was to be no such thing as hurry. Bob lay very still luxuriating in the thought. Then he glanced at Van, who was still immovable, his arm beneath his cheek. His friend's obliviousness to the world was irresistible. Bob raised himself carefully; caught up his pillow; took accurate aim; and let it fly. It struck Van in the head, routing further possibility of sleep. "Can't you let a fellow alone?" he snapped. "Wake up, you old mummy!" shouted Bob. "A great mountain climber you are, sleeping here all day. Have you forgotten you're going up Monadnock to-day?" "Hang Monadnock! I was sound asleep when you lammed that pillow at me, you heathen. What's the good of waking me up at this unearthly hour?" yawned Van. "It's seven o'clock." "Seven o'clock!" Van straightened up and stared. "Why, man alive, I haven't been asleep fifteen minutes." "You've been lying like a log for nine mortal hours," chuckled Bob. "Great Scott! Some sleep, isn't it? That's better than I do at Colversham." "Rat_her!_" "Well, I need sleep. I'm worn out with over-study." "You are, like--" "I am. I'm an intellectual wreck," moaned Van. "It's the Latin." Bob burst into a shout, which was cut short by a rap at the door. "Time to get up, boys," called the cheery voice of Mr. Carlton. "Step lively, please. Here's a can of hot water." The boys wasted no more time in fooling. They bathed, dressed, and almost before they knew it were at the table partaking of a hearty breakfast which was capped by heaps of golden brown pancakes rendered even more golden by the sea of maple-syrup in which they floated. "I'll never be able to climb anything after this meal," Van gasped as he left the table and was thrusting his arms into his sweater. Bob grinned. "Don't expect us back before late afternoon, Father," he called over his shoulder. "We've a long slow climb ahead of us because of the snow. Probably we shall find it drifted in lots of places. Then we shall want some time at the top of the mountain, you know. Besides, we're going to stop and cook chops, and that will delay us. So don't worry if we don't turn up much before dinner time." "You're sure you know the trail, Bob?" his mother called as the trampers went down the steps. "Why, Mother dear, what a question! Know the trail? Haven't I climbed that mountain so many times that I could go up it backwards and with my eyes shut?" "I guess that's true, Mother," agreed Mr. Carlton reassuringly. "Good-bye, then," said Bob's mother. "Have a fine day and don't freeze your noses." The boys waved, and with a scuff of their snow-shoes were off. The climb was indeed a stiff one. At first the trail led through low, flat woods, fragrant with hemlock and balsam; here it was sheltered and warm. But soon the real ascent began. "We follow the bed of this brook almost to the top," explained Bob who was leading the way. "We come into it here, you see. In summer it is a narrow path clearly marked by rough stones; you wouldn't believe how different it looks now all covered with snow. It doesn't seem like the same place. I didn't realize what a difference the snow would make in everything. But, anyway, we can't miss the way with these great boulders along the sides of the path; and even if we did the trees are blazed." They pushed on for some time. Then the strap of Van's snow-shoe broke. "Oh, thunder! Got a knife, Bob?" he called. "This darn thing's busted. I'll have to haul to for repairs." Bob stopped impatiently. "Why didn't you look at it before you started?" he said. "Never thought of it, Old Preparedness," was the good-natured reply. "No matter, I have some string and I think I can fix it." It took some time, however, to make the fastening to the shoe and moccasin secure, and in the meantime the sun went behind a cloud. "I guess Father wasn't a very good weather prophet," remarked Bob, glancing at the sky. "It seems to be clouding up." "Don't fret. What do we care?" was Van's easy answer. "We're not really after the view. I don't give a hurrah for what we see when we get to the top; what I want is the fun of doing it." They shuffled on. "I'll be glad when this luncheon is inside instead of outside of me, won't you?" puffed Bob. "It's almighty heavy to carry." "It isn't the lunch I mind. It's all these infernal clothes," was Van's retort. "I don't see what on earth I wore so many things for." "You'll want them by and by." "I bet I won't!" protested Van. "I'm going to tie my red sweater to this tree and leave it here; I can't be bothered with so much stuff." "You'll be cold when you get to the top." "No, I won't. And anyway I'd rather be too cold then than too hot now. One's no better than the other." Deaf to Bob's counsel Van resolutely wound the offending sweater about a great white birch tree that stood at a fork of the path. "You'll be sorry," was Bob's parting thrust as they plodded on. The trail was now steep and so narrow that frequently Bob had to stop and search for the blazing on the trees. "Of course I know my way, all right," he insisted. "Still, it is mighty different in winter from what it is at other seasons of the year, I'll admit that. Remember, I've never climbed this hill when the snow was on the ground. However, when we once get to the top the coming down will be a cinch, because we can follow our own tracks." It was nearly two o'clock before the boys reached the top of the mountain. Over the landscape hung a mass of heavy gray clouds beneath which the sun was hidden; the wind was cutting as a knife, and while Van sought the shelter of an old shack Bob roamed about, delighting in the familiar scene. "Why don't you come over here and look at the view?" he called to his companion. "It is fairly clear in spite of the clouds." Van shivered. "Oh, I don't want to. I don't care a hang for the view--I told you that before. I'm just hungry. Let's get a fire going and cook the chops. What do you say?" "You're cold. I said you would be." "I'm not. I'm starved, though. Where can we get some wood?" Bob glanced about. "There seems to be plenty of undergrowth down in that hollow. Take my knife and cut away some of it. There's a piece of an old stump, too, that ought to burn well if it isn't too wet." "That thing would never burn; but the brush will. Sling me the knife and I'll cut an armful. Let's build it in that little rocky shelter. Thanks to my camping training I'm right at home on this job." Van's boast was no idle one. Soon the fire was crackling merrily and the chops and bacon were sizzling in the frying-pan. Bob unpacked the sandwiches and the thermos bottle of hot chocolate. It was a regal luncheon. How good everything tasted! "I believe I was cold," Van admitted, rubbing his hands over the dying embers of the blaze. "But I'm warm as toast now. Is there any more grub left to eat?" "Not a crumb--why? Are you still hungry?" queried Bob who was packing up the camping kit. Van chuckled. "Well, not exactly. I only thought we ought not to waste anything." Bob glanced up and laughed; then his face grew sober. "I say, there's a snowflake!" he cried. "And another! Jove, Van, it's begun to snow!" "We better be getting down, I suppose," drawled Van. "Just that, old man; fast as we can, too. Come on." "What's your hurry? It will be a lark." "It will be no lark if it snows much--I'll tell you that," replied Bob seriously. "Besides, the folks will worry. Come ahead." They turned back down the trail. The snowfall increased. "You can hardly see our tracks already," Bob called over his shoulder. "And this wind is fierce. I had no idea it would snow. It is awfully wet and sticky snow, too; see how it clings to the trees." They sped on. The descent was far easier than the climb, and they could go quickly. "I don't remember that big rock," exclaimed Van suddenly, pointing to a huge boulder that fronted them. "Isn't it a whacker! Odd that I didn't notice it when we came up. Could we have passed it and not seen it?" [Illustration: "I DON'T REMEMBER THAT BIG ROCK"] "I suppose we must have," Bob answered. "I don't remember it, though. Everything looks queer and different in the storm. It's a regular squall. How quickly it came!" "Can you still see our tracks?" "No. But of course we're right; I couldn't miss my way after coming over this path so many times." "Can you see the blazes on the trees?" "No, silly. How could I when they are all plastered over thick with snow?" was Bob's scornful retort. He was silent for a moment. "But don't you worry," he declared. "I am certain we came this way--at least I _think_ we did." His tone, however, was less convincing. They went on. "We don't seem to be coming out anywhere, do we?" Van finally asked. "No." "Didn't we pass a little clearing somewhere on the way up?" "Yes, there was one." "Have we passed it?" "No." "Then it's ahead of us." "It ought to be. I say, suppose we stop a minute and brush the snow off these trees so to make sure we really are on the trail." "A bully idea!" The boys put down their packs and reconnoitred. "There don't seem to be any marks on these trees," Van asserted after an interval of search. "But there must be." "Find them then--if you can." Bob nervously scrutinized several gnarled trunks. "You're right, Van," he owned at last. "We're off the trail; missed it somehow. We'd better go back; we can't be far wrong. Or better yet, you wait here while I hunt." Bob was very grave. "You bet I'm not going to be left here to be buried in snow like the Babes in the Wood," protested Van gaily. "No sir-ee! I don't stay here. I'll help hunt for the path too. Now don't go getting nervous, Bobbie, old chap. Two of us can't very well get lost on this mountain. We'll separate enough to keep within hallooing distance, and we'll tie a handkerchief on this tree so we can get back to it again if we want to. We know we're part way down, anyway. That's certain." "I don't feel so sure," was Bob's answer. "We ought to have turned back when it began to cloud up; but I never dreamed of snow. The family will be having a blue fit about us." "Cheer up! We'll get down all right, only it may take us a little longer," Van asserted. They branched into a side path. The snow swirled about them in blinding sheets, and their footing became heavy and slippery. Wandering on, they scanned the trees. Not a mark appeared. Both boys were chilled now, and their spirits drooped. The possibility of being lost on the mountain began to definitely form itself in their minds. "I'm mighty sorry I got you into this scrape, Van," Bob said after a long pause. "I was too cock-sure of myself. That comes of thinking you know it all." "Pooh! It wasn't your fault, Bob. I'd give a cent, though, to know where we are. Do you suppose we've been making any progress all this time, or just going round in a circle?" "Search me. I'll bet we've walked miles," groaned Bob. "I've got to rest if we never find the trail." He spoke wearily. "You're not going to sit down, Bob," Van retorted sharply. "Brace up. You've got to keep moving." "But I can't. I'm tired and--and--sleepy." His voice trailed off into a yawn. "I don't care." Van wheeled on his friend fiercely and striding up to him shook him violently by the shoulders. "Now pull yourself together!" he commanded. "Where's your nerve? Brace up or I'll rattle the daylights out of you." "I can't go another step." "You've got to. Start on ahead. Don't crawl that way--walk! Faster! Faster than that, do you hear? I'm just behind you, and I shall step on your heels if you lag. Keep it up. Go on." Panting, Bob obeyed. Suddenly he gave a cry. "What's the matter?" demanded Van. "There! There on the tree!" He pointed before him with trembling hand. "Your sweater!" Van pushed past him. "Sure as fate! My sweater! Blamed if it isn't." They both laughed weakly. "Then we've found the trail!" Bob almost sobbed the words. "We sure have! And hark, don't you hear voices? It's David, as I'm alive; and your father!" Aid had indeed come. "Father!" Bob shouted the word and then laughed again--this time a bit hysterically. "The rescuing party's right here!" called Mr. Carlton. He said it lightly, but as he came up and joined them Van saw that his face was drawn and his eyes suspiciously bright. "David has the sledge just at the foot of the hill," he remarked, appearing not to notice the boy's fatigue. "I guess you'd just as soon ride the rest of the way." He slipped an arm around Bob. "It's not much farther, son. Move right along as fast as you can. Hurry, boy. Your mother's pretty worried. Thank goodness we found you in time." CHAPTER III SUGARING OFF The next morning, incredible as it seemed, Bob and Van were none the worse for their mountain trip, and Mr. Carlton, who had worried no little about them, and who was still feeling the effects of his hours of anxiety, remarked somewhat wrathfully: "You two fellows come to the surface like a pair of corks! Any one would think that being lost on a mountain was an every-day occurrence with you. That is the difference between sixteen and forty-six, I suppose. My poor old nerves rebel at being jolted in such casual fashion." Bob smiled. "We're fit as two fighting cocks to-day, Father," he declared. "In fact, this very minute we're going out to help David collect sap. They are going to boil a lot of it down to-day." "I imagined as much when I saw the smoke rising from the sugar-house chimney. Well, you seem to have your morning's work mapped out. Just don't get lost again, for I have no mind to go scouring the country a second time to find you." "We'll take good care, Mr. Carlton," Van replied, giving a final tug at his long rubber boots. "You may not lose yourself, Van," Bob chuckled, "but I am morally certain you'll lose your boots. You will just walk off and leave them in some snow-drift or mud puddle and never miss them. They are big enough for an elephant. Where did you get them, anyway?" "They're an old pair David lent me; your father said I'd better wear them." "He's dead right, too. The snow is still deep in spots, and it is thawing everywhere. It is not the boots I'm quarreling with; it's their size. I guess, though, you can get on somehow. We want to cut across the road and make for that hill over to the right. That's where the sugar-house is; it stands in the middle of an orchard of maples which were planted by my grandfather. Of course we have other maple trees scattered about the farm and David taps those, too; but most of our sugar comes from this orchard." "Did your grandfather make maple-sugar to sell?" "Goodness, no! He made it to use. White sugar, you must understand, was not so common in the olden days as it is now. Very little of it was grown in our country; and so, as it had to be brought from the East Indies, Spain, and South America, it was pretty expensive. Grandfather told me once that when he was a boy people used brown sugar or maple-sugar to sweeten their food, and sometimes they even used cheap molasses. White sugar was looked upon as a great luxury." "I don't think I ever realized that before," said Van thoughtfully. "Why, even my father remembers when, as a little shaver, he used to have white sugar spread on his bread for a treat." "Seems queer, doesn't it?" Van mused. "Yes. But it isn't so queer when you consider that all the sugar-cane now growing in America first had to be brought to the West Indies from Spain, the Canary Islands, or Madeira and then transplanted along the Mississippi delta. Dad says that originally sugar-cane came from Africa or India and that doubtless it was the Crusaders who introduced it into Europe." "Do you mean to tell me that people never knew about sugar until then?" inquired Van incredulously, halting in the middle of the road. "The Chinese were practically the only people who did, and they did not use it at all as we do; they just sweetened things with the thin sap." Van regarded his chum steadily for a moment. "Say," he demanded at last, "how did you come to know so much, Bobbie?" "What? Oh, about sugar? I don't know much. I just happen to remember a few scraps Father has told me from time to time. He's in the sugar business, you know." "Really? No, I didn't know. You never said anything about it. Cane-sugar?" "Yes." Bob watched Van curiously. "That's odd." "Why?" "Oh, because my father is in the sugar business too. Don't you recall my telling your father so? Yes, my dad makes beet sugar." "Then that's how my father happened to know your father!" exclaimed Bob quickly. "I suppose they're business friends. I've been wondering why Father kept watching you. Probably he sees in you some resemblance to your father. Do you look like him?" "I hardly know. Some people think I do. My mother says so," was Van's indifferent response. "But say, tell me more about sugar. You'd think with my father right in the business I'd know something about it; but I don't. Do they get sugar from anything beside beets, and sugar-cane, and maple sap?" "Oh, my, yes. There's sugar in ever so many other things: in grapes, and milk, and the date palm, and in maize; but it is from the beet and cane that the most sugar can be extracted." Van nodded. "You're quite a lecturer, Bobbie," he said. "Wait until I get back home and astonish my father with all this knowledge. I'll make his eyes stick out." Van broke into hearty laughter at the thought. Then, as he started to walk on he gave a shout of dismay. "Hold onto me, Bob," he cried. "I can't move. While I've been standing here listening to your words of wisdom I've been sinking deeper and deeper into your old yellow mud until now I can't stir. I can't--upon my word. My feet are in perfectly solid. You can laugh if you want to, but you've just got to pull me out, that's all. Help! Help! To the rescue. I shall disappear in another minute. David will never see his rubber boots again." "Of course you can get your feet out," was Bob's scornful retort. "Cross my heart I can't. Honest, Bobbie," protested Van. "I've got into a quicksand or a quagmire or something. Look at me. I'm up to my knees now, and if you don't hurry you'll see nothing of me but my collar. I saved your life yesterday; you might do the same for me to-day." But Bob was too convulsed with amusement to offer aid; instead he stood on a large rock at the roadside and laughed immoderately. "Pull! Pull!" he cried to Van. "Why don't you pull?" "I am pulling," Van answered. "But it does no good. I can't budge my feet. I never saw such mud in all my life. It must be yards deep. It sucks my boots right off. You'll have to help me." "Not I! I know too well what would happen. It would be like Kipling's story of the Elephant's Child. Don't you remember, when the crocodile let go the nose of the little elephant how he suddenly sat down _plop_. I've no notion of being pulled into this mud hole when your rubber boots come to the surface. You'll have to get yourself out." "You old heathen! It is not a straight game to fit me out with a pair of hip rubber boots miles too large for me and then sit and howl when you see me losing my life in them. Well, you needn't come into the mire if you don't want to, but you can at least be gentleman enough to pass me the end of that pole that is lying beside you," said Van. "I'll do that." Bob picked up a long branch from the ground. "Here!" he cried. "Catch hold of this and pull." The two boys tugged at opposite ends of the stick. Then suddenly and quite without warning something happened. The dead wood parted and Bob hurtled backward off the rock where he had been standing and landed in a snow-drift; while Van, much to his astonishment, sat down with abruptness in the wettest of the mud. Two more chagrined boys could nowhere have been found. Bob was the first to get to his feet. Shaking the snow out of his hair and collar he called: "Get up, you--unless you want to be swallowed up for life. My eye, but you're a sight! If your mother could only see you now. Well, your feet are out, if you did have to get in all over to do it. Now step lively if you don't want to get stuck again. You are a peach, I must say!" Van took the banter good-naturedly. "That's what one might call being buried alive," he answered. "Lucky it wasn't you! I'm tall and could keep my head out; but the mire would long since have closed over an abbreviated person like yourself and you would have been seen no more." Bob winced. He was sensitive about his height. Clambering up on the rock beside his chum Van scooped up a handful of clean snow and with it washed his hands and face. "There!" he said at length. "I'm just as tidy as if it had not happened." "I can't exactly agree with you," replied Bob, "but I guess you'll have to do. Come on now. Goodness only knows where David and the sledge have got to by this time." They hurried up the hill. "There's David!" Van said, as they reached the crest of the rise. It was David sure enough; and standing beside him in his customary motionless attitude was the Admiral harnessed into a great sledge surmounted by a barrel into which David was pouring the sap as fast as he gathered it. At the moment the man was busy detaching one of the sap buckets from the trunk of a giant maple. The boys joined him. "What are you doing, Dave?" asked Van curiously. "Doing! Ain't you got eyes, young man? I certainly ain't writing a book or taking a wireless message," he answered without turning his head. "But straight, I mean it. What are you doing? You know this business is new to me," explained Van. "Haven't you ever seen maple-sugar made?" David's tone was full of surprise. "Never." "Well, bless my soul! Where was you raised?" "In Colorado." "Humph! That accounts for it. If you'd been brought up in the East you'd have known." "But I was raised in the East, David, and I've never seen maple-sugar made," piped Bob, instantly overthrowing the old farmer's philosophy. "You ain't never--you ain't seen maple-syrup or maple-sugar made, Mr. Bob?" queried David aghast. "No." "Well, what are we coming to?" The farmhand surveyed the boys disdainfully. "What you been doing with yourself all your days?" he gasped at last. "I've been going to school." "And they ain't taught you to make maple-sugar? That's about all schooling is worth nowadays," he affirmed. "Now I warn't never inside a schoolhouse in my life, but I've known from the time I was knee-high to a grasshopper how to make maple-sugar. I made pounds of it before I was half the age of you two. The boys of this generation don't know nothin'!" He sniffed contemptuously. "Well, you may as well learn before you're a minute older," he continued. "Listen, now. Do you see the little hole in this maple?" He pointed up at the gray trunk above his head. "We make a little hole like that in every tree as soon as the sap begins to run in the early spring. Then we drive into the hole this small piece of hollow wood--it is like a trough, you see; and the sap runs through it into the buckets we hang beneath. All day and all night it drips in and each morning we go round and empty every pail into the cask we carry on the sledge. The sap, as you see, is thin, because only part of it is sugar; the rest is water. What we have to do is to boil down the liquid until the part that is water goes off in vapor and only the syrup is left. If we're after maple-syrup we let it cool when it gets thick and later bottle it; but if we want sugar we must boil the syrup still more until little crystals form in it." "How can you tell when it has been boiled enough?" questioned Van. "Oh, we've made it enough times to know," David replied. "Some folks stick a thermometer into it and figger how hot it will have to be; they say that's the best way. Others try the syrup in cold water or on snow like you would candy. Generally speaking, I can tell by the feel of it, and by the way it drips from the spoon. Sometimes, though, when I'm in doubt I try it on snow myself. If it gets kinder soft and waxy you can be sure it is getting done. If I was you instead of tracking round emptying buckets I'd go in the sugar-house and see 'em boiling the syrup. They started yesterday, and as I calculate it the mess ought to be pretty well along by now." "Bully idea, David! What do you say, Van?" asked Bob. "Shall we trail David or shall we go in and see the sugar made?" "Sugar! Sugar! Me for the sugar!" Van cried. "Sugar it is then!" Into the sugar-house they went. The small room was hot and steamy, and in the middle of it in a zinc-lined tank the foaming sap was boiling furiously. Beside it stood McMasters, Mr. Carlton's foreman, a thermometer in his hand. "Good-morning, Mr. Bob," he said. "So you are coming to cast an eye on the maple-sugar! Last week we made syrup and bottled it. Not a bad day's work, eh?" With no little pride he pointed to a row of neat bottles symmetrically arranged on a shelf. "We'll seal them to-morrow or next day and get the labels on, and then they will be ready to sell. But to-day it's sugar, so we have to keep the sap at a higher temperature." As he spoke he paused to test the bubbling liquid in the kettle. "If you lads want a treat take one of those wooden plates over there and fill it with snow; I'll spoon some of this hot sap over it, and you will have a feast for a king." The boys needed no urging. They took the plates, hurried out, and soon returned with them; over the heap of snow the foreman poured several heaping spoonfuls of hot syrup which, to their surprise, cooled in an incredibly short time and stiffened into a sticky mass that looked like candy. "Now get one of those wooden skewers from the shelf and use it as a fork," McMasters said. The boys caught the idea at once. They gathered the candied syrup up on the end of the sticks and thrust it into their mouths. "Why, it is just like toffy!" Van exclaimed. "It is a sight fresher than anything you could buy at the store," observed the foreman. "I believe I've got to have some more, Mac," Bob said. "Somehow it melts away before you know you're eating it." He refilled his plate with fresh snow and held it out for a second helping of syrup. McMasters filled it good-naturedly. But when the plates were extended the fourth and fifth time the Scotchman demurred. "It is no stuff to make a meal of, Mr. Bob," protested he. "And at ten o'clock in the morning, too. I'll give you no more. It is too sweet. Next you know the two of you will be spending your vacation in bed and wondering what's the matter with you. Why, we'd have no sugar at all if you should stay here eating at this rate. If it's candy you're wantin', ask the cook to boil some maple-syrup until it is thick like molasses candy; then turn it out of the pan and when it is almost cool pull it until it turns white. You'll find it better than any candy you can buy. Try it." "We certainly will, Mac, and thanks for the suggestion," Bob replied. "And while you're at it you might hunt up some butternuts and stir them in; I'll recommend the result and will wager you'll think it as good as anything you ever ate." Once more he took the temperature of the steaming sap. "We're going to put some of the sugar in those tin pails and sell it," he continued. "Each pail holds ten pounds. And some we shall pour into those small tin moulds and make little scalloped cakes for our own use. I reckon you can have some of them to take back to college when you go. We'll certainly have a plenty to spare you some, for your father will make a handsome thing out of his sugar this year. I wouldn't wonder but you're being educated on maple-sugar money. You better make your bow of thanks to the trees as you go through the orchard," he added whimsically. CHAPTER IV THE REFINERY Vacation with its country sports came to an end only too quickly, and leaving the New Hampshire hills behind the Carlton family, together with Van Blake, set out for New York where the boys were to make a weekend visit before returning to Colversham. "I wish while we're in New York we could go through your refinery, Dad," Bob remarked to his father. Mr. Carlton glanced at him in surprise. "What set you thinking of that, Bob?" he asked. "You never were interested in sugar making before." "I know it, Father." Bob flushed guiltily. "I ought to have been. But since we have seen maple-sugar made Van and I thought it would be fun to see the process that white sugar has to go through before it is ready for the market." "Van thought so, did he?" queried Mr. Carlton. "Why, yes, he thought so. I believe, though, it was I who suggested it." "Humph!" murmured Mr. Carlton. He mused a moment. "I suppose it would do no harm," he said at last, half to himself. "Harm!" "No, no! Of course not," interrupted Mr. Carlton hurriedly. "The process is an open secret anyway, except perhaps--Oh, I guess it would be all right." Bob regarded his father with a puzzled stare. "I will arrange for you and Van to go through the works right away," continued Mr. Carlton. "It simply will be necessary for me to telephone the superintendent and tell him you are coming so he will have some one on hand to explain things to you. This was your scheme, you say?" "Yes, sir. Why?" "Nothing, nothing," was Mr. Carlton's enigmatic reply. He was as good as his word, for despite his peculiar reluctance in the matter he lost no time in perfecting the plan, and the next morning after the party reached New York he informed the boys that the motor-car would be at the door at nine o'clock to take them to the refinery. Bob and Van, to whom New York was more or less of an old story, hailed this announcement with pleasure and promptly stowed themselves away in the big limousine which was to whirl them to Long Island where the works were located. All the way out Van was singularly silent, and appeared to be turning something over in his mind; once he started to speak, but checked himself abruptly. Bob watched him uneasily. "I believe you've lost your enthusiasm about sugar," said he at last, "and did not really want to come." "What a notion! Of course I wanted to come." "But you seem so glum, old man." "Glum! Nonsense! I never was in better spirits in my life." With a sudden shifting of the subject Van pointed to a stack of chimneys cleaving the sky and observed: "I wonder if those belong to your father's plant?" "I fancy they do," was Bob's quick answer. "Dad said we'd see a bunch of tall chimneys, and that the refinery was of yellow brick." "Then this is the place," Van declared, drumming on the window glass with forced gaiety. He did not, however, leap from the car with the spring of anticipation that Bob did, and noticing his spiritless step his friend once more remarked upon it. "You seem bored to death to have to drag yourself through here, Van," said he. "What's the matter? You know if you do not want to come you don't have to." "I do want to." "But somehow you seem so-so--" "So _what?_" "Why, you seem to hang back as if you could hardly put one foot before the other," answered Bob. "Don't you feel well?" "Prime! There's nothing the matter with me. What put that idea into your head?" "Chiefly you yourself." "Well, cut it out. I don't see what you're fussing about me for. I'm just as anxious to see how sugar is made as you are." Still Bob was unconvinced. He could not have explained why, but he felt certain that Van's enthusiasm was feigned. For a second he paused undecidedly on the pavement before the door of the great factory; then shrugging his shoulders he entered, followed closely by his chum. It was evident that they were expected, for a clerk rose from his desk and came forward to greet them. "Mr. Hennessey, the superintendent, said I was to bring you to his office when you arrived," he said. "Thank you." "You are Mr. Carlton's son, aren't you?" "Yes." "I thought you must be. Mr. Hennessey himself is going to take you through the works." The clerk led the way to the door of a private office, where he knocked. "Mr. Carlton and his friend are here," he announced to the boy who opened the door. "Tell Mr. Hennessey right away." The boys had not a moment to wait before a large man with a genial face and outstretched hand came forward. "I'm glad to see you, Mr. Carlton," he said. "I'm Hennessey, the superintendent. Possibly you may have heard your father speak of me; I have been helping him make sugar for twenty years." Bob smiled up into the eyes of the big man looking down at him. "Indeed Dad has spoken of you, Mr. Hennessey," he said, returning the hearty hand-shake. "He depends on you a lot. He says he always feels sure that when you're on the job everything will be all right." Mr. Hennessey flushed with pleasure. "I merely try to run your father's place as if it were my own," was the modest rejoinder. "That's just it--that's why Father feels he can go to the North Pole if he wants to and not worry while he's gone," nodded Bob. "I think it is mighty good of you to bother with my chum and me. Can't you send some one to take us through the refinery? There is not the slightest need for you to go with us yourself." "Oh, I wouldn't think of turning you over to some one else. You see I am interested in your sugar education; I can't allow the boss's son to get a wrong start in the business," laughed Mr. Hennessey. "I'm afraid I'm not starting in the business," protested Bob, shaking his head deprecatingly. "I'm only trying to learn a little something about Dad's job, so I can be a bit more intelligent about it." "You're going to investigate the way your father earns his money, eh?" chuckled the superintendent. "Well, I'll tell you right now you need do no blushing for your father's business methods; he makes his fortune as cleanly and honestly as any man could make it." "I'll take a chance on Dad," was the laconic response. "You can do so with safety." There was a pause and turning Bob introduced Van Blake. Then after the two boys had been provided with duck coats so that none of the sticky liquid that sometimes dripped from the machinery should spot their clothing the three set out for the basement of the factory, where the incoming cargoes of sugar were unloaded. Here great bags or casks of raw sugar were being opened, and their contents emptied into wooden troughs preparatory to cleansing and refining. Both lads regarded with surprise the material that was being tipped out into the bins. "Why, it looks like nothing but coarse, muddy snow!" ejaculated Van. "Do you really mean to tell us that you can make that brown stuff white, Mr. Hennessey?" "That's what we're here for," answered Mr. Hennessey, obviously enjoying his amazement. "All raw sugar comes to us this way. You see, it is about the color of maple or brown sugar, but it is not nearly so pure, for it has a great deal of dirt mixed with it when we first get it." "Where does it come from?" inquired Bob. "Largely from the plantations of Cuba and Porto Rico. Toward the end of the year we also get raw sugar from Java, and by the time this is refined and ready for the market the new crop from the West Indies comes along. In addition to this we get consignments from the Philippine Islands, the Hawaiian Islands, South America, Formosa, and Egypt. I suppose it is quite unnecessary to tell you young men anything of how the cane is grown; of course you know all that." "I don't believe we do, except in a general way," Bob admitted honestly. "I am ashamed to be so green about a thing at which Dad has been working for years. I don't know why I never asked about it before. I guess I never was interested. I simply took it for granted." "That's the way with most of us," was the superintendent's kindly answer. "We accept many things in the world without actually knowing much about them, and it is not until something brings our ignorance before us that we take the pains to focus our attention and learn about them. So do not be ashamed that you do not know about sugar raising; I didn't when I was your age. Suppose, then, I give you a little idea of what happens before this raw sugar can come to us." "I wish you would," exclaimed both boys in a breath. "Probably in your school geographies you have seen pictures of sugar-cane and know that it is a tall perennial not unlike our Indian corn in appearance; it has broad, flat leaves that sometimes measure as many as three feet in length, and often the stalk itself is twenty feet high. This stalk is jointed like a bamboo pole, the joints being about three inches apart near the roots and increasing in distance the higher one gets from the ground." "How do they plant it?" Bob asked. "It can be planted from seed, but this method takes much time and patience; the usual way is to plant it from cuttings, or slips. The first growth from these cuttings is called plant cane; after these are taken off the roots send out ratoons or shoots from which the crop of one or two years, and sometimes longer, is taken. If the soil is not rich and moist replanting is more frequently necessary and in places like Louisiana, where there is annual frost, planting must be done each year. When the cane is ripe it is cut and brought from the field to a central sugar mill, where heavy iron rollers crush from it all the juice. This liquid drips through into troughs from which it is carried to evaporators where the water portion of the sap is eliminated and the juice left; you would be surprised if you were to see this liquid. It looks like nothing so much as the soapy, bluish-gray dish-water that is left in the pan after the dishes have been washed." "A tempting picture!" Van exclaimed. "I know it. Sugar isn't very attractive during its process of preparation," agreed Mr. Hennessey. "The sweet liquid left after the water has been extracted is then poured into vacuum pans to be boiled until the crystals form in it, after which it is put into whirling machines, called centrifugal machines, that separate the dry sugar from the syrup with which it is mixed. This syrup is later boiled into molasses. The sugar is then dried and packed in these burlap sacks such as you see here, or in hogsheads, and shipped to refineries to be cleansed and whitened." "Isn't any of the sugar refined in the places where it grows?" queried Bob. "Practically none. Large refining plants are too expensive to be erected everywhere; it therefore seems better that they should be built in our large cities, where the shipping facilities are good not only for receiving sugar in its raw state but for distributing it after it has been refined and is ready for sale. Here, too, machinery can more easily be bought and the business handled with less difficulty." "You spoke of a central sugar mill," began Bob. "Yes. Each plantation does not have a mill of its own or, indeed, need one. Frequently a planter will raise too small a crop to pay him to operate a mill; so a mill is constructed in the center of a sugar district, and to this growers may carry their wares and be paid in bulk. It saves much trouble and expense. It also encourages small growers who could not afford to build mills and might in consequence abandon sugar raising. The leaves are all stripped off before the cane is shipped so that nothing but the stalks are sent. As the largest portion of sugar is in the part of the cane nearest the ground it is cut as close to the root as possible. After the juice has been crushed from the stalks by putting them several times through the rollers the cane, or _begass_, as it is called, is so dry that it can be used as fuel for running the mill machinery." "How clever!" "Clever and economical as well," agreed Mr. Hennessey. "Moreover, it does away with a waste product that otherwise would accumulate." Bob nodded. "Raw sugar has usually been shipped to the northern refineries by water, as that mode of transportation is cheaper; but during the Great War ships have been so scarce that in 1916 a large consignment of Hawaiian sugar was for the first time sent overland across the American continent by train; this of course made the freight rates higher, and if such a condition were to continue the price of sugar would of necessity have to be advanced." "I never thought of such things affecting us," murmured Van. "We live in a network of interdependence," Mr. Hennessey replied. "Scarcely anything can be done in any land that does not affect us. Commercial conditions react upon us all, for there is not one of us who is not indebted to the four corners of the globe for what he eats, wears, and uses. Therefore, you see, world prosperity and comfort can be at their height only when there is world peace under which all nations are friends, maintaining cordial trade relation with one another." "What political party do you belong to, Mr. Hennessey?" asked Bob, glancing into the superintendent's earnest face. "I do not know just what label you would put on me," the big man replied evasively. "But this I do know: first, last, and all the time I am for a universe where each country shall work for the good of the whole." He spoke slowly and with impressiveness; then breaking off abruptly he led the way up a winding iron staircase and the boys, still pondering his words, followed him silently and thoughtfully. CHAPTER V VAN SPRINGS A SURPRISE The room into which they emerged was at the top of the factory, and it was here in great vats that the dry sugar was melted. "We often melt down as many as two million pounds of raw sugar a day," said Mr. Hennessey. "The United States, you know, is the greatest sugar consuming nation in the world. No other country devours so much of it. One reason is because here even the poorer classes have money enough so they can afford sugar for household use; in many countries this is not the case. Only the well-to-do take sugar in tea or coffee and have it for common use. Our Americans also eat quantities of candy. At the present time children eat three times as many sweets as did their parents, and the amount is constantly increasing. Doctors tell us sugar is one of the fuels necessary to the human system; it generates both heat and energy. Possibly it is because our people work so hard and are driven at such high nervous tension that they demand so much of this sort of food." "I never knew before that candy was good for us," ejaculated Bob in surprise. "Oh, bless you, yes! But you must take it in moderation if you wish to benefit from it and escape illness. Used intelligently sugar is an excellent food, but of course you must prescribe it for yourself in the proper proportions," laughed Mr. Hennessey. "We all constantly take more or less sugar into our systems through the ordinary foods we eat. But here in America over and above this each individual annually averages about eighty pounds of sugar. You will agree that that is a good deal." "I should think so! Why, that is a tremendous amount!" Van declared. "It seems so when you see it in figures, doesn't it?" returned the superintendent. "Next to the United States in sugar consumption comes England, the reason for this being that the English manufacture such vast amounts of jam for the market. England is a great fruit growing country, you must remember. The damp, moderate climate results in wonderful strawberries, gooseberries, plums, and other small fruits. With these products cheap, fine, and plenty, the English have taken up fruit canning as one of their industries, and they turn out some of the best jams and marmalades that are made." The boys listened intently. "The Germans and the French are much more frugal than we Americans," went on Mr. Hennessey. "Sugar is not so common in their countries. Often when in Germany you will notice people in the restaurants and cafés who carry away in their pockets the loaf sugar which has been allotted them and which they have not had occasion to use. It is a common occurrence, and considered quite proper, although it looks strange to us. Doubtless, too, if you have traveled abroad you have discovered how few candy shops there are. Foreigners regard the wholesale fashion in which we devour sweets with wonder and often with disgust. They consider it a form of self-indulgence, and indeed I myself think we are at times a bit immoderate." "My father says we are an immoderate people," Van put in. "I am afraid he is right," nodded Mr. Hennessey. "We seem to proceed on the principle that if a thing is good we must have a great deal of it. However, the vice--if vice it be--is good for the sugar business." He paused a moment and stood looking down into the great foaming vats before him. "You can't see the steam coils that are melting this raw sugar," he remarked. "They go round the inside of the tanks. But after the liquid is drawn off you can see them. When first melted the sugar is far from pure; you would be astonished at the amount of dirt mixed with it. Many of these impurities boil up to the surface and over and over again we skim them off. But even after that we have to wash the sugar by various processes. After it has been separated, clarified, and filtered it comes out a clear white liquid, and is ready for the vacuum pans, where the water is evaporated and the sugar crystallized." "How do you get the liquid clear?" asked Bob. "After it has been skimmed as carefully as possible we first settle it through the agency of chemicals," answered Mr. Hennessey. "We use milk of lime as a foundation, but we put other things with it. Our exact formula is a secret, but since you are in the family I guess there would be no objection to my telling you that we use---" "Don't tell us! Don't tell us!" cried Van suddenly. "I don't want to know. I'd rather not. I mustn't listen." Covering his ears the boy turned away. His companions regarded him with amazement. "Don't tell me, Mr. Hennessey," he pleaded. "Don't tell me anything that is secret. I can't listen. It wouldn't be right." It was evident both to the superintendent and to Bob that his distress was real, and although neither of them understood it Mr. Hennessey cut short his explanation. Try as they would the strange interruption left a jarring note behind it, and to ease the tenseness the older man stepped forward and, taking from a rack near by one of several glass tubes filled with yellow liquid, held it up to the light. "You see much must still be done to this stuff before it comes out white," he said. "We squeeze the liquid through a series of filter bags and also send it through other filters filled with black bone coal." "What is black bone coal?" Bob demanded. "Bone coal is a product made by burning and pulverizing the large bones left at the abbatoirs until a coarse-grained black powder not unlike emery sand is made; if this is not allowed to become too fine with using it is an excellent sugar filter. In fact, strangely enough, nothing has ever been found to take its place, and it has become a necessary but expensive agency employed in every sugar refinery. Quantities of it are used; in our refinery alone we have about a hundred bone coal filters and each one holds thirty tons of black bone coal. That will give you some idea how much of it is needed. We get nothing back on it, either, for in the process of using it becomes finer, and after that it is good for nothing unless, perhaps, to be made into cheap shoe-dressing. Unlike many of the other industries sugar refining has no by-products; by that I mean nothing on which the manufacturer may recover money. On the contrary in the leather business, for example, almost every scrap of material can either be utilized or sold for cash; odds and ends of the hides go into glue stock, small bits of leather are made into heel-taps or hardware fittings. But in refining cane-sugar there is nothing to be turned back into money to reimburse the manufacturer for his outlay. What isn't sugar is dead loss." The three now moved on and saw how the heated juice traveled by means of pipes from one vat to another, and how it constantly became thicker and clearer. "One of the greatest dangers to successful sugar making is fermentation," observed Mr. Hennessey. "Sugar must continually be stirred by revolving paddles to keep it from fermenting; we also are obliged to take the greatest care that our vats and all other receptacles are clean, and that the plant is immaculate. Frequently we wash down all the walls with a solution of lime in order that the entire interior of the refinery may be quite fresh." "I didn't dream it was so much work to make white sugar," ventured Bob, a little awed. "Our maple-sugar making was much simpler." "I'll venture to say it was," agreed Mr. Hennessey. "In the first place, you did not make such a quantity of it; then you did not try to get it white. Furthermore, you were content to take it in cakes. Making cane-sugar is, however, easy enough if one is careful and knows the exact way to do it. There is plenty of opportunity to spoil it--I'll admit that; but it is seldom that a batch of our sugar goes back on us. We have fine chemists who watch every step of the process and who constantly test samples of the liquid at every stage into which it passes until it comes out water-white." "And then?" "Then follows crystallization, and this too requires skilled workmen and extreme care. The water is evaporated and the sugar crystallized in the vacuum pans, the size crystal depending upon the temperature at which the liquid is boiled. It takes a lower temperature to form a small crystal and a higher one to form a large crystal. An expert who takes the temperature of the boiling sugar regulates what we call fine-grain or coarse-grain sugar by regulating the size of the crystals. By drawing off some of the liquid and examining it on a glass slide by electric light he can tell the precise moment at which the crystals are the right size. Each size has a name by which it is known in the trade: Diamond A; Fine Granulated; Coarse Granulated; Crystal Domino; Confectioners' A and so on." They were walking as Mr. Hennessey talked. "After the sugar has been crystallized in the pans it passes into a mixer, where it is stirred and kept from caking until it is put into the centrifugal machines, which actually spin off the crystals. These machines are lined with gauze, and as they whirl at tremendous velocity they force out through this gauze the liquid part of the sugar and leave the sugar crystals inside the machine. When these are quite dry the bottom of the receptacle opens, and the granular sugar is dropped through into a large bin." "But I should think it would stick together," objected Van. "That's an intelligent objection, my boy," declared Mr. Hennessey, much pleased at Van's grasp of the subject. "It would stick if it were not dried off by a degree of heat just right to keep the particles separate and not allow them to cake. After this any dust or dirt adhering to the sugar is blown off by an air blast. The product is then ready to be pressed into moulds or cut; boxed in small packages of varying weights; or put into bags or barrels." Mr. Hennessey led the way to another floor of the refinery. [Illustration: "I SHOULD THINK IT WOULD STICK TOGETHER."] Here were automatic machines upon which empty boxes traveled along until they reached a device that filled each one with the exact number of pounds to be contained in it, the package afterward passed to women who sealed it tightly and gave it the final touch before it was shipped. Other women were packing loaf or domino sugar, while down-stairs in a cooper shop men moved about constructing with great rapidity the barrels that were to carry larger quantities of sugar to the wholesale and retail stores. "I guess by this time you've had all the sugar-making you want for one day," declared the superintendent. "I'm afraid I've given you quite a stiff lesson. You see I am so interested in it myself that I forget to have mercy on my listeners." He smiled down at the boys. "I'm sure we have had a fine morning with you, Mr. Hennessey, and we certainly have learned a lot," Bob said, putting out his hand. "I can't swear, though, that we could make white sugar even now." "Faith, I'd be sorry if I thought I could teach any one the whole process in three hours. It would make my twenty years of study and hard work brand me as pretty stupid," chuckled the big superintendent. CHAPTER VI A FAMILY TANGLE It was not until the boys were in the motor-car and returning home that Bob ventured to mention to Van his strange behavior of the morning. "What on earth was the matter with you, Van?" he asked. Van stirred uneasily. "Bobbie," he said, "I'm going to tell you something. I've been wondering whether I'd better or not, and at last I've decided to. I didn't want to go to your father's refinery to-day or, in fact, at all. You've all been very kind to me, although it was not until I got a letter from my father this morning that I realized how kind." He paused. "Has your dad told you anything about my people?" he asked abruptly. "Of course he knows, but he may have thought best to keep it to himself; at any rate it has not prevented him from giving me as cordial a welcome to your home as he would if--" "If what?" "Well, if I weren't the person I am." "What do you mean?" "Why, he's trusted me and treated me as if he really liked me; and yet under the circumstances you can't expect him actually to mean it." "Mean what? What are you talking about?" "Hasn't he spoken to you about my father?" "Of course not; why should he?" "Then you haven't heard anything?" "Not a word. I don't understand what you are driving at at all," Bob declared, somewhat irritated. "Out with it. What's the matter?" Van hesitated as if uncertain how to begin. "That's mighty white of your father," he murmured, breaking the pause. "You see, it is this way. When I wrote home that I was going to New Hampshire to visit my roommate the family wrote me to go ahead. I recall now that I didn't mention your last name; in fact I guess I haven't in any of my letters. When I did happen to write (which wasn't often) I've always spoken of you as _Bob_. So when I got to Allenville I dropped a line to Father to say I'd arrived safely and in the note I put something about Mr. Carlton. Father lit on it right away; he wished to know who these Carltons were. I replied they were Mr. and Mrs. Carlton, of course--the parents of my roommate. Upon that I got another letter from home in which Father inquired if your father was in the sugar business, and said that years ago he used to have a partner named James Carlton, who started in the sugar trade with him and with whom he later quarreled. He supposed this could not be the same person, but he just wondered if by any chance it was." Van stopped. "Was that all he said?" "No, but I don't like to tell you the rest, Bobbie." "Fire away--unless it is something about Dad," Bob replied. "If it is I shan't listen, or at least I shan't believe it." "It isn't exactly against your father. I do not understand it very well myself. My father just said that if your father was Mr. James Carlton and he was in the sugar business he felt that because of family misunderstandings it would be better if I did not visit here again. He was very sorry I had done it this time, but of course that could not be helped now." "You don't mean to say he wants you to break off your friendship with me?" Bob gasped tremulously. "No, he didn't seem to be opposed to you; he just was hot at your dad. He added that he didn't believe your family could have known who I was when they asked me here, and I am afraid that's true, Bobbie." "Why, of course they knew! Haven't I spoken of you over and over again?" Bob protested indignantly. Van shook his head. "They knew I was your chum all right, Bob; but so far as details were concerned your family did not know much more about me than mine knew about you. Don't you recall how, when I arrived at Allenville, your father asked if I was one of the _Sugar Blakes_--Asa Blake's son?" "Yes, I do remember that now, but--" "That, you will recollect, was after I was landed at Allenville and your guest. Your father didn't know until that moment who I was, and when he found out he was too decent to say anything, or make it evident he didn't want me in the house. What could he do?" "But--but--" Bob broke off from sheer inability to continue. He was much too bewildered. "Your father sensed the awkwardness of the situation at once. Here you had gone to school and as ill luck would have it you had picked from out the entire bunch of boys the son of his worst enemy for a chum. Neither your father nor mine realized the truth until you innocently carted me home with you for a holiday visit. When your father found out the fact he was too polite to turn me out-of-doors; he just acted the gentleman and made the best of a bad dilemma," explained Van with appalling convincingness. "He even had the goodness to save my life the day we got lost on one of your New Hampshire mountains. He didn't tell you any of this because he didn't want to spoil your pleasure; but I am certain that if he had known who I was before I came he would not have allowed you to ask me into your home." "Nonsense! You are way off. Why, he's been as interested in having you with us as I have; at least he has acted so." "_Acted_ is just the word," Van cut in. "He has acted, all right. I guess you'll find he's been acting all the time. Honor bright, hasn't he said anything to you about me?" "No, not one word." Then suddenly Bob flushed; the memory of his father's strange conversation about the boy's visit to the refinery rushed over him. "Dad did say one thing which I did not understand at the time," he confessed reluctantly. "Perhaps, though, he did not mean anything by it." "What was it?" Bob struggled to evade the issue. "Oh, it was nothing much." "Come, Bobbie, you and I are friends," interrupted Van, "and we want to keep on being friends no matter how our fathers feel toward one another. If they have quarreled it is a great pity, but at least we needn't. The only way to straighten out this tangle is to be honest with each other and get at the truth; then, and not until then shall we know where we stand." "You're a brick, Van!" "Come ahead then--let's have it. What was it your father said?" "He merely asked whether it was your plan or mine to visit the refinery, and when I told him I suggested it he inquired all over again if I was sure you did not mention it first," Bob returned in very low tone. The words seemed wrung from him, and he colored as he repeated them. "Was that all?" "Not quite. After I had convinced him that the trip was my own idea he said: '_Well, well--it can do no harm; the process is an open secret, anyway._'" "You see I was right in my guess as to his feelings, Bobbie." "Maybe." "Of course I was; this proves it." "I'm afraid so," whispered Bob miserably. "Now all this may explain to you why I was so queer when we were at the refinery this morning," Van continued, once more reverting to the subject. "Do you understand it any better?" "I can see you didn't want Mr. Hennessey to tell you much about his processes." "You bet I didn't. I was in an awful hole. I got that letter from my father just before we left the house, and I was all upset over it. I didn't know what to do. It was bad enough to be visiting you without being shown all through your father's business plant as if I were an honored guest. It didn't seem as if I ought to go at all. If your father knew who I was he certainly couldn't want me to; and if he didn't it was worse yet. At first I thought the only honorable thing was to go straight to him and have it out; but I found I hadn't the nerve. Then I thought I'd ride with you to the factory and not go in. What I dreaded was that we might run into something that I should have no right to see, and that was precisely what happened." "So that was the reason you stopped Mr. Hennessey when he started to tell us the chemical formula?" "Yes. He said it was a secret, and it seemed to me it would be wrong for me to listen. If I didn't know what that formula was I certainly couldn't tell it, and ignorance might help me out of an awkward position if any one should try to persuade me to." "You are a trump, old man." "It was only the square thing toward your father; he has been straight with me and I want to show him that I can be a gentleman, too." The boys were silent for an interval; then Bob said: "Now about this snarl, Van--what are we going to do? Certainly we fellows are not going to let this feud of our fathers affect us." "Not by a jugful!" retorted Van with spirit. "The thing for us to do is to go right on being friends as if nothing had happened. It will make it all the easier that your father knows just who I am, and my father knows exactly who you are; it is franker and more in the open to have it so. If worse comes to worse we can talk the whole thing out with our families, and tell them how we feel. I am sure both your father and mine are too big to spoil a friendship like ours because of some fuss they had years and years ago. No, sir! I'm going to hold on to you, Bobbie, and," he added shyly, "I'm going to hold on to your father, too, if he'll let me, for I like him." "I'm glad you like Dad," Bob said, flushing with pleasure. "I do myself." "My dad isn't so bad, either," Van ventured with a dry little smile. "Some time you shall see for yourself." "I hope so." "Then it is agreed that we'll stick together, no matter what happens," said Van solemnly. "Sure thing!" "Promise." "You may bank on me," was Bob's earnest answer. CHAPTER VII MR. CARLTON MAKES A WAGER AND WINS As the boys sat at dinner that evening Mr. Carlton inquired about their trip to the refinery, and with a humorous twinkle in his eye added: "I do not suppose you would care to put in another day on factory visiting, would you?" "What do you mean, Dad?" asked Bob. "I was wondering whether you would like to see where some of our sugar goes," was his father's answer. "Would you be interested to take a tour through the Eureka Candy Factory to-morrow and learn how candy is made?" "I should," responded Bob promptly. "And you, Van?" demanded Mr. Carlton with a kindly smile. "I'd like it of all things," said Van, returning the smile frankly. "Very well. You shall spend to-morrow at the Eureka Company's factory. They are big customers of ours and when I telephoned them today they told me they would be glad to have you come, and promised to show you all about." "Are you sure they would want me to come, Mr. Carlton?" asked Van, looking squarely into the eyes of the older man. "Why not? You're a chum of Bob's, aren't you?" "Yes. But, you see, that isn't all." With one searching glance Mr. Carlton scanned the lad's face. "No, Van," he replied with quiet emphasis, "that is not all. You are more than Bob's chum--you are a friend of mine, too." The boy flushed. "I'd like to think so, Mr. Carlton." "I want you to know so, Van. I happened to see Mr. Hennessey," he went on in a lower tone, "and he related to me that incident at the factory. Of course he did not understand it, but I did--instantly. I appreciated your sense of honor, my boy." "I wanted to be square." "You were a gentleman in the very best sense of the word." A great gladness glowed in Van's eyes, for terse as was the phrase it bore to him the very recognition he had coveted from Bob's father. Mr. Carlton, however, did not enlarge upon the subject, but casting it swiftly into the background asked: "Are you sure you both would rather spend your last morning in New York going through a candy factory than doing anything else? Factories are tiresome places, you must remember." "But a candy factory could never be tiresome!" asserted Bob. His father laughed. "There are just as many miles in a candy factory as any other," he replied. "Any of the men who work there would tell you that, I fancy." "But they are such nice miles!" argued Bob. "Don't you say we go, Van?" "I sure do. I want to see how they dip chocolates," Van answered. "It's all aboard to-morrow morning, then," Mr. Carlton said as he lit his after-dinner cigar. "There's one thing, Dad, that it's only fair to warn you about," called Bob, turning on the lowest step of the stairway to address his father. "Our expedition may cost you something. You see they probably won't let us eat any candy at the factory; we'll just have to walk round with our eyes open and our hands crammed into our pockets to keep from swiping it. All the time we'll be getting up a tremendous candy appetite, and the minute we get outside we'll just have to make a bee-line for the first candy shop in sight and get filled up. So you must be prepared to cash in for refreshments." The corners of Mr. Carlton's mouth twisted into an enigmatic smile. "I'll agree to pay for as much candy as you care to eat," he said, accepting the challenge without objection. Bob stared at him. "Do you mean it?" "Certainly. Why do you question it?" "But"--faltered Bob in amazement, "you never promised anything like that before." "I may never promise it again, so make the most of it," was the dry retort. Although Bob did not reply he by no means forgot the unprecedented offer, and that the memory of it might be equally fresh in his father's mind he spoke of it once again when the three parted the next morning. "Well, Dad, we're off for the Bonbon World," he called as he passed the library door where his father sat looking over the morning's mail. "Remember you are going to O.K. any candy bills we run up." "I'm backing you for all you can eat," nodded Mr. Carlton. "Dad sure is game!" Bob declared as he and Van stepped into the waiting motor-car and began their ride to the factory. "He'll play it out, too. He never goes back on his word." "I'm afraid he'll be in for something then," grinned Van. Both boys were more than ever convinced of the truth of this remark when they entered the factory and were greeted by the mingled aroma of chocolate, wintergreen and molasses. "I could eat ten pounds of chocolates this minute!" exclaimed Van. "Go easy. Remember, we've got to wait until we have made the entire tour of this factory before we can have so much as a single caramel. You mustn't go getting up your appetite so soon." "But smell it, Bobbie! Why, the whole place is one mellifluous smudge. What do you say we chuck Colversham and get a job here? Think of having pounds of candy--tons of it--around all the time! Wouldn't it be a snap!" Van was cut short in his rhapsody by the approach of a pleasant faced lad of about his own age who was dressed from head to foot in white and wore a little white cap, across the front of which was printed in gold letters the word _Eureka_. "Are you Mr. Carlton?" he inquired of Van. "I'm not, but my chum is." "We were expecting you," the boy answered, turning to Bob. "I am to show you and your friend through the works. Will you kindly step this way?" Tagging at the heels of their white-robed guide Bob and Van made their way through a large storeroom stacked to the ceiling with fancy boxes of various sizes, shapes, and colors. "Give up Colversham, Bob, and maybe you could come here and wear a white suit every day and personally conduct visitors through the works; perhaps they'd even pay you in bonbons," whispered Van. "He must be about our age," returned Bob. "I wonder what they pay him." "I'd lots rather have had a man take us round," said Van softly. "Do you suppose this fellow knows anything?" All the way up in the elevator the two visitors watched the white-suited boy curiously and when they alighted in the large, sun-flooded room at the top of the factory they were still speculating as to his age and how much he earned, and marveling that so young a representative should have been selected to explain to them the candy industry. The room they entered was high and airy and at the further end of it, moving amid steam that rose from a score of copper kettles, a great many men in spotless white were hurrying about. "It is here that we start our candy making," said the boy who was showing Bob about. "Into those copper kettles we put our mixture of confectioners' sugar--confectioners' A, we call it--and corn syrup; this combination forms the basis of almost every variety of candy made. The kettles, as you will see, are heated by gas, which gives a steady flame, and at the side of each one we have a thermometer by which we can tell the exact temperature of the mixture. There is also a glass disc set in the side of every kettle to enable us to watch the boiling. The sugar and corn syrup are melted together and cooked at the temperature which after repeated experiments has proved the most successful for our purpose--one that will neither burn nor stick, or make the cooled fondant too thin to keep its shape." The boy spoke in the slow, measured tones of one who had told the tale many times before and was quite accustomed to his task. Bob glanced at Van. Their respect for the lad was rising. "How much does one of these kettles hold?" Bob asked. "About six hundred pounds." "And you fill all of them every day?" demanded Van in astonishment. "Several times over," was the answer. "It takes a lot of this ground material for the different kinds; some of it has other ingredients mixed with it later, and some is beaten, flavored, and colored for the fillings of chocolates." "But who on earth eats so much candy?" ejaculated Bob. "I don't know," responded the boy wearily. "I'm sure I don't." "What?" "I don't believe I'd touch a piece of candy for a hundred dollars," he continued. "I am sick of the sight of it. Candy from morning to night--candy, candy, candy! Candy everywhere! Nothing but candy." Bob and Van eyed him unbelievingly. Could a boy be human and feel that way? "Everybody here gets into the same state of mind," the lad went on. "When the green hands come they are crazy about the stuff for about a couple of days; then it is all over. You couldn't hire them to eat. Every few weeks the different employees are allowed to buy two pounds for themselves at the wholesale price, but you would be surprised to see how few of them do it. If they get it you can be pretty certain that it is to give away, for they'd never eat it themselves." His two listeners stared incredulously. Their guide led them across the room. "So," said he, reverting once more to the kettles and the thermometer, "our candy is not made by guesswork, you see. Sugar costs too much to risk having such a large batch as a kettleful spoiled. We boil it by the thermometer, and when it is at just the right point we take it off and put it into these coolers, where it thickens and is reduced to a workable temperature. That which is to be used as filling is then shifted into these big cylindrical cans that have inside them a series of revolving fingers and here the candy is beaten until quite smooth; whatever flavoring or coloring matter is needed is beaten into it." As the machinery whirled the boys stood watching the beaters. "Some of this beaten sugar will be colored pink, flavored with rose or wintergreen, and used for the centers of chocolate; some will have maple flavoring, some vanilla, some lemon. Nuts will be stirred into some of the rest of it. There is an almost endless number of ways in which it may be varied. Come over here and see them preparing the centers and getting them ready to cover with chocolate." It was an interesting process. Shallow wooden trays filled with dry corn-starch passed beneath a machine which left in them rows of empty holes the size of the heart of a chocolate cream. The trays then moved on until they stopped just under a nozzle, which ran exactly the right amount of liquid filling into each hole. The dryness of the corn-starch prevented the mixture from flowing together. As soon as every hole in the tray was filled with fondant it was set away to cool and an empty tray substituted. When the little centers were hard enough they were taken out of the corn-starch moulds, and after being put upon traveling strips of fine wire netting, melted chocolate was poured over them. The wire frames sped along like miniature moving sidewalks, their contents drying and cooling on the way. In the meantime the superfluous chocolate dripped through the netting into a trough beneath and was collected to be melted over again. On went the finished chocolates until they reached the packing-room, where girls removed them from the frames, sorted them, and put them into boxes. "These are not what is known as hand-dipped or fork-dipped chocolates," explained the boy. "Those are higher priced, because they require individual attention, and the material put into them is more expensive. To make those the girls take the centers and submerge each one in melted chocolate with a dipping-fork, finishing the pieces with a certain little twist or decoration on top; it requires no small amount of skill to make this top-knot, which not only serves to render the candy more attractive but to distinguish one variety of filling from another. Each kind has its own particular decoration. After some practice any of us might, I suppose, learn to make the twist on a chocolate once; but to make that precise thing each time and never vary it would be quite a different matter. It is important the pattern should be uniform, since both the dippers and the packers must know what is inside; in addition those who sell the candy must know. It is no easy task. After the chocolates are finished _Eureka_ is stamped on the bottom of every piece and they are ready to be sold." "I don't see what prevents your candy from sticking to everything," observed Van thoughtfully. [Illustration: "IT IS NO EASY TASK"] "Blasts of cool air that come through those overhead pipes. We can turn on the current whenever we wish. Whenever the girls who are packing candy find that it is becoming soft they turn on a current of cold air to chill and harden it; we often use these cool blasts, too, when handling candies in the process of making. Such kinds as butter-scotch, hoarhound, and the pretty twisted varieties stick together very easily. If they are allowed to become lumpy or marred they are useless for the trade and have to be melted over." "What are those men over there doing?" inquired Bob, pointing to a group of workmen who were stirring a seething mixture of nuts and molasses. "Some of them are making peanut brittle, some caramels; and in the last kettle I believe they are boiling hoarhound candy. See! The last man is ready to empty his upon the table. Suppose we go over and watch him." They reached the spot just in time to see the kettle lifted and the hot candy poured out upon the metal top of the table, where it spread itself like a small, irregular pond. At once the workman in charge took up a steel bar not unlike a metal yardstick and began pressing down the mass to a uniform thickness. This done he ran the bar deftly beneath and turned the vast piece over just as one would flop over some gigantic griddle-cake. He continued to change it from side to side, pressing it down in any spot where it was too thick, but never once touching it with his hands. He then cut off a long narrow strip and fed it into a machine at his elbow, the boys regarding him expectantly. Suddenly, to their great surprise, the formless ribbon of candy that had gone into the machine began to come forth at the other end in prettily marked discs, each with the firm name stamped upon it. "Hoarhound tablets, you see," observed the boy. "The Italian who is making peanut brittle has flattened his on the table in the same fashion and marked it into bars which later will be cut and wrapped in paraffine paper." "I never realized so much candy was manufactured in one day," exclaimed Bob as they went down in the elevator. "Oh, this isn't much," returned the boy. "We are running light just now. You should come a few weeks before Christmas if you want to see things hum here." "I guess that would be a good time for visitors to keep out," returned Bob as they smilingly bade good-bye to their guide and started home in the motor-car. As the automobile glided into Fifth Avenue Van said: "Look, Bobbie, there's a candy shop! I suppose all that stuff in the window was made in exactly the same way as those things we saw to-day, don't you?" But Bob did not turn his head. Instead he replied: "Don't say candy to me. I do not want to lay eyes on another piece of it for a week!" "Nor I!" Van echoed. "Do you wonder that boy at the factory feels as he does? I guess your father can keep his money so far as we are concerned. He'll have no candy bills from us." * * * * * In the meantime Mr. Carlton waited for the tremendous bonbon bill that had threatened to reduce his bank account, and when it was not forthcoming he nodded his head and chuckled quietly to himself. CHAPTER VIII VAN MUTINIES Another day passed and Bob and Van were once more back at Colversham greeting the boys and vainly endeavoring to settle down to the work of the last term. "It seems as if the stretch from April to June is about the hardest pull of the whole year," yawned Van, looking up for the twentieth time from his Latin lesson and gazing out into the sunny campus. "Studying is bad enough at best, but when the trout brooks begin to run and the canoeing is good it is a deadly proposition to be cooped up in this room hammering away for the finals." "It always seems worse after a vacation," agreed Bob, tilting back in his chair. "You'll get back into the harness, though, in a day or two; you know you always yap just about so much when you first get back to school." "I don't yap, as you call it, any worse than most fellows do. I hate being tied up like a pup on a leash. It seems as if I'd just have to get out and play ball--and if you were a human being you'd want to, too," growled Van. "Hang it all, don't you suppose I want to?" Bob retorted. "What do you think I'm made of, anyway?" "I don't know, Bobbie. Sometimes you're so resigned I begin to fear you are a mummy," was Van's laughing retort. "Now, I'm not like that. It is one big grind for me to study. The minute spring comes it seems as if I never could translate another line of Cicero as long as I lived, and I don't care a hurray what X equals. What will it matter a hundred years hence whether we plug away here at this stuff, or get out and play ball?" "I guess you'd find it would matter to you right now without waiting for the end of a century," was the laconic answer. "But speaking of ball, what wouldn't you give to see the first League game of the season in town, Saturday? That will be some playing!" "I clean forgot the season opened this week," exclaimed Van. "Since I got back here I've been all mixed up on dates. I thought it was next week. Are you sure it's Saturday?" Bob nodded. "Positive." "It'll be a cracker-jack game," mused Van. "I'd give something to be there. You don't suppose we could get off at noon and go, do you?" "Not on your life! Right now, after vacation? What do you take this school faculty for--an entertainment committee? You seem to forget we'd have to cut algebra, and English, and gym." "I shouldn't care." "I should. I'm working this trip, and can't afford to miss recitations," was Bob's sharp reply. "As for you, you can afford to miss them even less than I can--you know that. Put it out of your head. When you can't do a thing there is no use thinking about it and wishing you could." "I see no earthly harm in talking about it." "I do. It just keeps you stirred up." "Then what did you mention it for in the beginning?" "I don't know. I wish to goodness I hadn't," Bob declared. "Well, in spite of your opinions I repeat I'd give a fiver to see that game Saturday." "You can't, so cut it out and let me finish this theme. Every time I've started to write you've broken in and driven every blooming idea out of my head. Now quit it. You better pitch into your own work for to-morrow. Dig out all the Cicero you can, and later I'll help you with the rest." With finality Bob wheeled his chair around and proceeded to submerge himself in his task. But not so Van. He took up his book, to be sure, but over the top of it his eyes roved to the world outside, and fixed themselves dreamily on the line of hills that peeped above the tips of the red maples budding in the school campus. He was far away from Colversham and its round of duties. In imagination he moved with a gay, eager crowd through the gateway leading into the great city ball ground. He could hear the game called; watch the first swirl of the ball as it curved from the pitcher's hand; catch the sharp click of the bat against it; and join in the roar of applause as the swift-footed runner sped to second base. Everybody would be at that opening game! Not to go when it was within trolley distance was absurd. What was algebra, English, or a little wall-scaling compared to such an opportunity? And, anyway, who would be the wiser? There must be ways of getting off so nobody, not even Bob, would know. If only Bob could be persuaded to cut school! But it was never any use to urge Bob when he spoke in that horribly positive tone. You might just as well try to move a lighthouse. Van glanced furtively at his chum who, unconscious of his scrutiny, was writing steadily down a long page of foolscap. The sight had a steadying effect. Van again took up his book and scowled once more at that same old line at the top of the page. But all the time between his eyes and his Latin lesson swayed that alluring throng of pleasure seekers. Impatiently he tried to banish them, but stern as was his attempt their laughter still sounded in his ears. Against his will he was back at the ball game, and this time he was on his feet shouting wildly with the other fans as Carruth, the star batter, made a soaring hit and stole two bases on it. In that instant of unreined enthusiasm Van Blake decided that come what might he would go to the game on Saturday--go even though his whole term's work went for naught. The resolve made he tried to stifle his conscience by falling upon his Latin with unwonted zeal, and so ardently did he wrestle with it that when, an hour later, Bob pushed aside his papers and offered to help him with the lesson he was able to greet his chum with a translation so far beyond his customary efforts that Bob patted him on the head with paternal pride, exclaiming: "Bully for you, old man! That's about the best work I ever knew of your doing. The middle of it is a little queer, but we'll fix that up all right. Who says you're not a Cicero?" "Bobbie, if I thought for one moment that there was any danger of my becoming a Cicero or any other Latin worthy I'd go drown myself!" Van cried, startled at the mere thought. "I'm not so worse, though, am I? I'd no idea I could reel it off like that." "Of course you can do it. Why, Van, you could do all kinds of things if you'd only go at them. The trouble with you is that you always study with one eye out the window. If you'd only get down to your job with all your might you'd not only get your lessons better but you'd learn them in half the time." "I 'spect that's so," drawled Van lazily. "I ought to duff right in on all fours. I acknowledge it. But it is not so easy to make your mind go where you send it." He broke off, shifting the subject to athletics, and was in the highest spirits the rest of the day; but underneath all his fun and banter the question constantly arose in his inner consciousness: How could he elude his roommate's watchfulness and on the coming Saturday escape to the great game? Strangely enough Fortune seemed to smile upon his plot, for Friday morning Bob was taken to the infirmary with a sore throat, which, although slight, isolated him from the rest of the boys. No longer was he at Van's elbow to watch, warn, or censure. The coast was entirely clear. Van formulated his plans. Directly after luncheon on Saturday he would start for the city, hugging the edge of the campus and afterward cutting across the adjoining estate to meet the car line where it forked into the main road. Many another boy had done the same and not been caught; why not he? It was, to be sure, against the rules to leave the school grounds without permission, but one must take a chance now and then. Did not half the spice of life lay in risks? Accordingly after the noonday meal was finished and the boys had scattered to recitations or the dormitories Van sauntered idly out past the tennis-courts; across the field skirting the golf course and then with one sudden plunge was behind the gymnasium and running like a deer for the thicket that separated Colversham from the Sawyer estate. He knew the lay of the land perfectly, for this short cut was a favorite thoroughfare of the boys, in spite of the posted protest of _No Trespassing_. Creeping cautiously through the shelter of the orchard he contrived to escape observation and reach the highway in safety; at this quiet noon hour the road was entirely deserted save for the presence of one small boy who was jogging on ahead, a dinner pail upon his arm. He was a slender little fellow of six or seven years who whistled shrilly as he went and kicked up clouds of dust with his bare feet. As Van watched the sway of his shoulders and the unhampered tread of his unshod feet he could not but recall the days when he, too, had gloried in going barefoot. He smiled at the memory which now seemed so absurd. A slight sound behind him broke in upon his reverie. Bounding the turn just at his back swept a big scarlet touring-car driven by a solitary man. It was coming at tremendous speed and no horn had given warning of its noiseless approach. Van had but an instant to step out of its path when on it shot, bearing down on the unconscious boy ahead. The little chap was walking in the middle of the road and whistling so loudly that no hint of the oncoming danger reached him. The man in the motor saw the child and sounding his horn, swerved to the left; but it was too late. The speeding car caught the lad, struck him, and tossed him to the roadside rushing on in its mad flight faster, if anything, than before. In vain did Van call after it. His protest was useless. The great red vehicle whirled forward, a speck in the sunshine, and was lost to view. Terror-stricken Van darted to the child's side and bent over him. His eyes were closed and an ugly gash in his forehead was bleeding profusely. [Illustration: NO HORN HAD GIVEN WARNING] Binding a handkerchief round the little fellow's head the older boy lifted him in his arms and retracing his steps ran with him down the road, across the Sawyer lawn, and up the steps of the Colversham infirmary. A young orderly who was lounging at the door came forward and on seeing the child's face spoke quickly to a physician who was passing through the hall. Together they took the little boy from Van's arms and carried him to a cot in an adjoining room, anxiously plying Van with questions as they went. Briefly Van related the story. "Such men should be hung! Prison is too good for them!" snapped the doctor angrily. He passed his hand with infinite tenderness over the tiny, still form on the bed. "Is he much hurt, sir?" questioned Van eagerly. "I can't tell yet. He is hurt enough so that he doesn't come to his senses, poor little chap! Here, Jackson, ring for a couple of nurses. We'll get the child up-stairs." Van tagged behind them more because he was anxious to hear of the lad's condition than because he could be of any real use. As the sad procession left the elevator, emerging into the corridor on the second floor, a tall man who was coming down the stairway confronted them. It was Dr. Maitland, the principal of the school! "What's this?" he asked, advancing with swift stride. The doctor hurriedly explained the circumstances. "A motor accident on the Claybrook Road, you say? Well, well! Poor little chap! Who brought him in?" "This lad--one of the schoolboys. You showed good judgment, Blake, and it was a mighty fortunate thing that you were there," observed the surgeon, passing on. "The Claybrook Road?" repeated the puzzled principal. "You were on the Claybrook Road, Blake? And what were you doing there at this time of day?" With throbbing heart Van suddenly came to himself. Up to that instant no thought of his own peculiar plight had crossed his mind. Now the reality of his dilemma rushed upon him with pitiless force. "May I ask," repeated the principal in measured tone, "what were you doing on the Claybrook Road at this hour, Blake?" CHAPTER IX VAN'S GREAT DEED Dr Maitland, who was a man of unswerving justice, was influenced in his judgments neither by pity nor explanations, and thus it came about that when Van had answered his questions, putting before him the facts about his runaway, the principal sent the boy to his own room to there await sentence Van was in the lowest of spirits. What would the penalty of his insurrection be? He knew Dr. Maitland far too well to expect mercy, nor did he wish it. He was too proud for that. He had disobeyed the rules of the school, and he must now bear the punishment, be it what it would. The thought of holding back the facts had never entered his mind. Indolent he sometimes was even to laziness but never within his memory had he been dishonest. So he had fearlessly told the truth, and despite the calamity it threatened he found himself the happier for telling it. Whether it would mean expulsion from Colversham he did not know; probably it would. To think of leaving Colversham, the place he loved so much! And in disgrace, too. What would the other boys say? And his father? Van shrank at the thought of telling his father. Mr. Blake was a severe man who, like Dr. Maitland, would not gloss over the affair either by tolerance or sympathy. He would be angry, and he would have the right to be. Van admitted that. As he looked back on his school days he realized for the first time how indulgent his father had been; he had denied his son no reasonable wish, simply asking in return that the boy express his gratitude by studiousness and obedience. Van flushed as with vividness it came to his consciousness that he had repaid his father's goodness with neither of these things. He had studied just as little as was possible, and in place of appreciation he had rendered nothing but disgrace. His self-esteem was at a very low ebb when Bob, dismissed from the infirmary, returned to his old quarters. Van was seldom depressed--so seldom, in fact, that the sight aroused in his chum nothing but an anxiety lest he be ill. Surely nothing but sickness could cause Van Blake to lie on a couch, his face buried in pillows! "What's the matter, old fellow?" called Bob the instant he was inside the door. "Are you used up?" No answer. "I say, what's the trouble?" Bob repeated, hurrying to his side. It took much questioning before the story could be drawn from the boy's reluctant lips. "When Bob had at last heard it he was silent. "Can't you say something?" queried Van peevishly. "I hardly know what to say," Bob answered with slow gentleness. "I'm so sorry--so sorry and upset. I can't for the life of me understand how you came to do such a thing. Did you expect to get away with it? You must have known you would be missed at recitations and tracked down." "That's right--rub it in!" "I'm not rubbing it in; I'm only trying to understand it." "There's nothing to understand. I just was crazy to go to that ball game and I started. I should have gone, too, if it hadn't been for the kid getting hurt." "It was bully of you to bring him back, anyway," Bob said. "Of course you knew it was all up with you when you did it." "I didn't think about it at all. I wasn't thinking of anything but that poor little chap who was mowed down by the brute in that car. If I hadn't happened to hear the motor it might have been me instead. I wish it had been," he declared gloomily. "No you don't. Great Scott, cheer up, Van! The country hasn't gone to the dogs yet. I must admit you are in a mess; but it doesn't begin to be the mess it would have been if you had gone to the game, had a bang-up time, and come home a sneak who had stolen his fun. At least you have done the square thing and 'fessed up, and now you'll be man enough to take what's coming to you. What do you suppose Maitland will do?" "I can guess pretty well--pack me off home. He is stiff as a ramrod on obedience to the school rules," sighed Van, "and he's right, too. It is perfectly fair. I knew it when I went." "I can't see, just for one afternoon of sport, how you--" Bob broke off. "If I'd only been here you never would have gone." "Maybe not," admitted Van. Then he added in the same breath: "No, I shouldn't have gone if you had been here, Bobbie. Somehow you're my good angel. I wrote Father so the other day." "Stuff!" "It's true. You are such a brick! I thought you'd blow my head off when you'd heard what I'd done." "Well, I am mad enough to do it," was the tart reply. "For you to go and do a thing like that just for a ball game! It wasn't worth it. Think of your being pitched out of Colversham for a measly game of baseball. And you didn't get there, either!" Van kicked the pillows impatiently. "Don't light into me, Bobbie," he moaned. "Don't I feel bad enough as it is?" "I don't know whether you do or not; you ought to." "I do, Bob. I'm dead sorry." "If you'd stay sorry it might do some good," returned Bob. A sudden thought seemed to strike him. He did not speak for a few moments; then he said half aloud: "Who knows--it might help." "What might help?" "Nothing." Bob got up and sauntered to the door. "Will you stay right here like a decent chap and not get into any more mischief until I get back?" "Where are you going?" "Nowhere much--just across the campus for a little while. I'll be back soon. Will you wait here exactly where you are?" "Yes, but--" "Honor bright?" "Sure!" "All right. Don't quit this room until I come. So long!" Bob was gone. Van lay very still after the door had closed, and to keep him company in his solitude back swarmed all those dreary thoughts that Bob's cheery presence had for the time being banished; with a rush they came to jeer, taunt, and terrify. The _little while_ lengthened into an hour and on into a second one. The room became intolerable. Then upon the stone floor of the corridor outside sounded Bob's foot. "Still here, Van?" he cried, coming in with elastic step and banging the door after him. His face was wreathed in smiles. "What's happened to you that you look like that?" questioned Van, sitting up among the pillows. "Like what?" "Why, as if somebody had sent you a Christmas-tree or made you president of a railroad?" Bob laughed. "I've been to see the Head," he said. "Humph! I never knew of his causing any one such overwhelming delight," observed Van a little spitefully. "Hush up, old man; don't run down the Doctor," Bob said. "You may have more cause to be grateful to him than you know." "You don't mean--" Van's voice trembled. "Did you go to see him about me?" Bob nodded. "Bob! How did you dare?" "I dare do anything that becomes a man; who dares do more is none," quoted Bob merrily. "I don't believe, though, I'd have dared go for myself," he answered. "It is different when you are doing it for some one else. Now sit up and listen and I'll tell you all about it. The Doctor was mighty white about you; but in spite of all he stuck to the fact that you'd disobeyed the rules; he kept going back to that every time I tried to switch him off. We squabbled over you a solid hour, and the upshot of it was this: you are to stay at Colversham--" "Hurrah!" Van hurled a pillow into the air. "Shut up and hear the rest of it. You are to stay here because I promised upon my word of honor that you would keep straight and study." "I'll do it." "That isn't all." Bob hesitated. It was a wrench for him to deliver the remainder of the message. "Yes, you are to stay," he repeated as if to gain time. "But of course you can't expect to slip through with no punishment at all." "No, indeed!" Still Van spoke with jaunty hopefulness. "The Doctor thinks it is only fair that you should be pretty severely reminded of what you've done." "That's all right. I'm not afraid. Fire ahead! What's he going to do with me?" "He thinks--he says--he feels it is best--" "Oh, come on, come on--out with it!" "He has forbidden you to take any part in the school athletics this spring," was the reluctant whisper. Van did not speak. "I'm mighty sorry, old fellow," declared Bob, "but it was the best I could do." Still Van made no reply. With troubled gaze Bob regarded his chum. "I'd far rather Maitland had knocked me out," he ventured at last. Stooping, he put his hand on Van's shoulder. Van roused himself and looked up into his friend's face with one of his quick smiles. "It's all right, Bob," he said. "Don't you fuss about me any more. You were a trump to get me off as well as you did. I'll take my medicine without whimpering. I ought to bless my stars that my banishment from athletics is only temporary. Suppose I had been smashed up so I could never play another game like that little kid, Tim McGrew," he shuddered. "It was just sheer luck that saved me. Why, do you suppose, he should have been the one to be crippled and I go scot free?" he observed meditatively. "I don't know. Maybe because there is something in the world that only you can do. My father believes that." "Do you?" "I don't know." "It would be strange, wouldn't it, to feel you were let off just to do something?" mused Van. "You'd be wondering all the time what it was. Of course it would be something big." "You could never tell what it was," Bob replied, falling in with his friend's mood. "I suppose the only way to make sure would be to do whatever came to you the best way you could do it. You never could be sure that what you were doing was not the great thing." "Not studying and stuff like that." "It might be; or at least studying might lead to it." "I don't believe it." "It wouldn't hurt you to try it." "No, I suppose not." Then with characteristic caprice Van shifted the subject. "But seriously, Bobbie, there is something I am going to do. You'll howl, I guess, and maybe you'll be disappointed, too. It's about that sick kid, Tim McGrew. The surgeon says the little beggar will never walk again. I feel pretty sore about it; I suppose because I was there," explained Van uneasily. "I've about decided to chip in the money Father was going to send me for a canoe and get a wheel chair for him. His folks are poor, and can't get one, and the doctor says--" "You're a--" "Oh, shut up, can't you, Bobbie? It's only because I'm so cut up about the accident. Remember, it might have been me instead of him. You won't mind much if we don't have the canoe, will you?" "No," was the low answer. Neither of the boys spoke for some time. Then Bob whispered: "Have you thought, Van, that maybe the thing you are to do is something for that little lame boy, Tim McGrew?" CHAPTER X HOW VAN BORE HIS PUNISHMENT The spring term passed much faster than either Bob or Van dreamed it would and despite the absence of athletics Van Blake found plenty to do to fill the gap left by this customary activity. In the first place there was his studying. Had not Bob assumed an obligation that must be lived up to and that was quite as binding as if it existed on paper instead of in a mere invisible point of honor? He was very grateful to Bob and had given bond that he would live up to the pledge his chum had made for him. Now he must fulfil his promise, Van argued. So although the call of the springtime was strong and difficult to resist he had been faithful to his work, "plugging away," as he expressed it, with all his strength. To his surprise the task, so irksome at first, became interesting. It was a novel experience to enter a classroom and instead of moving in a mental haze possess a clear idea of what was going on. Twice he was able to furnish the correct answers to Latin questions on which every one else had failed, and what a thrill of satisfaction accompanied the performance! The attitude of his teachers changed, too. Formerly they had been polite; now they became even cordial, demonstrating by an unsuspected friendliness that they were after all ordinary human beings and rather likable ones at that. They were moreover amazingly sympathetic and met every endeavor of Van's with generous aid. Perhaps schools were not the prison-houses he had formerly thought them! There had, of course, been no chance to conceal from the boys the reason of his banishment from the ball field and tennis-courts; such a story as the motor accident travels with insidious speed. Before a day had passed from one end of Colversham to the other everybody knew that Van Blake had disobeyed the school rules and had in consequence forfeited his place in out-of-door sports. Van, however, was a great favorite and the manly way in which he accepted his penalty provoked nothing but admiration and respect from his classmates. He frankly admitted his mistake, owning that while his sentence was severe it was perfectly just; nor would he permit a word of criticism of Dr. Maitland's decree to be voiced in his hearing. "Maitland is all right!" was his hearty endorsement, and that remark was the only encouragement his pals received when they came to condone with him. Gradually the affair dropped out of sight. Van went among the boys, cheerily giving advice as to the make-up of the school teams and even coaching the fellow who was to serve as his successor as pitcher on the nine. Nevertheless there still remained quite a margin of leisure, and it was during this lonely interval when every one else was training for the coming games that he would stray off by himself and visit little Tim McGrew. Between the two a peculiar friendship sprang up. On Van's part it arose from forlornness mingled with a half formulated belief that he must do something to express his thankfulness that he himself had escaped from the fate that had overtaken the child. On the small lad's side it had its root in gratitude and hero-worship. In Tim's eyes Van Blake was an all-powerful person. Was it not he who had picked him up and carried him to the hospital? And had not this same big schoolboy bought the beautiful wheel-chair that enabled one to travel about the house and yard almost as readily as if on foot? In addition to all this was it not Van who came often to the house, never forgetting to bring in his pocket some toy or picture-book? Small things they often were--these gifts that meant so much to the child--often things of very slight money value; but to the invalid whose long, tedious days of convalescence were stretches of monotony the tiny presents seemed treasures from an enchanted land. Tim was now at home in the shabby cottage on the outskirts of Colversham where he lived with his mother and four sisters. Poor as the place was it was spotlessly neat and Tim's family were spotlessly tidy too. Mrs. McGrew, who supported her household by doing washing for some of the families in the town, might have had a permanent and much more lucrative position elsewhere had it not been for leaving her five little ones; as it was, she clung to her children, struggling to meet her living expenses as best she could. It had been a sore grief to her when Tim, her only boy and the baby of the home, had become crippled. Perhaps she sensed more clearly than did the lad the full seriousness of the calamity. As for Tim, he accepted it in childish fashion, hopefully ignoring the problems of the future. To Van Blake Mrs. McGrew was all gratitude. Of all her children her boy was her favorite. "But for you, sir, little Timmie might have been left at the roadside to die," she would exclaim over and over. "We'll never forget it--never--neither I nor the children!" It was thus that Van became the hero of the McGrew household, and the warmth and genuineness of the welcome he unfailingly received there aroused in him an answering friendliness. Many a time when he saw things either new or interesting he would find himself instinctively saying: "I must tell Tim about that," or "I must take that to Tim." But with his enthronement as the sovereign of Tim's universe there came to Van a very disquieting experience. Tim thought his big friend knew everything, and in consequence whenever he became puzzled about facts that were being read to him or that he heard he would instantly appeal to Van, whom he was sure could right every sort of dilemma that might arise. But too often the unlucky Van was forced to blush and falter that he would have to look it up; and when he did so he frequently learned something himself. For Tim never forgot. No sooner would Van be inside the gate than the shrill little voice would pipe: "And did you find out how far away Mars is, Mr. Blake?" Poor Van, it kept him scrambling to satisfy Tim McGrew's intellectual curiosity, yet there was a tang in the game that rendered it very interesting. He found, too, ample reward in seeing the wee invalid's face brighten when the query was answered. So the spring sped on. In the meantime Van had heard only irregularly from his parents. In a long letter to his father he had sent all the facts of his disgrace at school and had added that he was truly sorry; the reply he received had been terse and rather stern but not unkind. Mr. Blake expressed much regret for his son's conduct and closed his epistle with the caustic comment that he should look for a proof of Van's desire to make good. That was all. Van knew that Dr. Maitland had also written; but what he did not know was that with the fearlessness so characteristic of him Bob Carlton had taken the time and trouble to pen a long note to Colorado as a plea for his chum. It was a remarkable composition from a boy so young--a letter full of affection and earnestness and voicing a surprising insight into his friend's character and disposition. Mr. Blake read it over three times, and when he finished sat in a reverie with it still between his fingers. The tone of it was so like the man he had known long ago, that friend from whom a misunderstanding that now seemed pitiably trivial had separated him. It had been his fault; Mr. Blake could see that now. He had been both hasty and unjust. Over him surged a great wave of regret. Well, it was too late to mend the matter at this late day. One chance was, however, left him--to make up to the son for the injustice done the father. It therefore came about that at the close of the school term Bob Carlton was overjoyed to receive from Van's parents an invitation to come west with their boy and pass the summer holidays. Such a miracle seemed too good to be a reality, and the lads' instant fear was that the Carltons would be unwilling to spare Bob from home for such a long time. To their surprise, however, Mr. Carlton welcomed the plan with enthusiasm. A trip to Colorado would be a wonderful opportunity, the educational value of which could scarcely be estimated, he argued. Underneath this most excellent reason there also existed on Mr. Carlton's part a desire to show his former partner that he cherished no ill will for the past. Who knew but the boy might even be a messenger of peace? So one June morning, after bidding good-bye to Colversham and to Tim McGrew, the two lads set forth on their western journey. They were in high spirits. Both had passed the examinations with honors, and as Van thought of his achievement again and again he wondered if it could be true that he was one of that light-hearted band who were starting off on their summer vacation with no conditions to work off. The solitary cloud on the horizon was the grief of little Tim at having his friend go. But Van promised there should be letters--lots of them--and post-cards, too, all along the route; the parting would not be for long anyway. These were some of the thoughts that surged through Van's mind as he and Bob settled themselves into their places on the train and began the attempt to fathom the reams of directions Mr. Blake had sent them; pages and pages there were of what to do and what not to do on the long trip, the letter closing with the single sentence: "I am trusting you to make this journey alone because I believe your chum, Bob Carlton, has a level head." "If your own head is not level, Bobbie, it is at least an honor to be associated with a head that is," remarked Van humorously. "I guess that is about all the recommendation you need from Dad, old boy. I wonder how he happened to take such a fancy to you without ever having met you." "I wonder," echoed Bob quietly. CHAPTER XI THE BOYS MAKE A NEW ACQUAINTANCE To Bob every mile of the western journey was a step into Wonderland; novel sights, novel ideas confronted him on every hand and viewed through the medium of his enthusiasm things that had become threadbare to Van became, as if by magic, suddenly new. The greatness of the country was a marvel of which Bob had never before had any adequate conception. Then there were the cities, alive with varying industries, and teeming with their strangely mixed American population. Above all was the amazing natural beauty of scenery hitherto undreamed of. Hour after hour Bob sat spellbound at the window of the observation-car, never tiring of watching the shifting landscape as it whirled past. His interest and intelligence caught the notice of a gentleman who occupied the section opposite the boys, and soon the three formed one of those pleasant acquaintances so frequently made in traveling. Mr. Powers (for that was the stranger's name) was on his way back to his farm in Utah, and very eager was he to reach home. "So many things on the place need my attention that the journey you are delighting in seems very long to me," he remarked to Bob one morning as they came from the dining-car. "Is your farm a large one, Mr. Powers?" questioned Bob. Mr. Powers smiled. "It is larger than you would want to build a fence around," he returned humorously. "I suppose you have all sorts of cows and pigs and horses on it, and raise every kind of fruit and vegetable that ever was invented," put in Van mischievously. Mr. Powers shook his head and looked not a little amused. "No. We have only enough stock for our own use--nothing fancy. I do not go in for show farming. I raise only one thing on my land, and I'm going to see if you are clever enough to guess what it is." "Alfalfa!" cried Bob instantly. "No. How did you happen to think of that?" "Oh, I've read that lots of western farmers raised it." "True enough. It wasn't a bad guess, but it was not the right one," said the stranger. "Now suppose we hear from your chum." "Corn." "Still wrong; but you are getting warmer." "Wheat." "Wheat is not as good a random shot as corn." "It must be a vegetable," declared Bob thoughtfully. "Let me see. Not potatoes?" "No." "Of course it couldn't be peas, or beans, or squash, because you said once you had hundreds of acres, and you would never raise any of those things in such large quantities," argued Van. "Spinach, tomatoes--" "I have it!" cried Bob. "You should have guessed it the first thing, Van." "Why?" "Can't you think? With your father right in the business you ought to." "Beets," exclaimed Van. "Beets it is!" agreed Mr. Powers. "So your father is interested in beets too, is he? You don't chance to be the son of Mr. Asa Blake, do you?" "Yes, sir." "That is a coincidence," observed Mr. Powers much interested. "I sell all my crops to him. I expect then, young man, you know all there is to be known about growing beets." "On the contrary, I don't know a thing," Van confessed laughing. "Dad has never talked to me much about his business. He is too busy to talk to anybody," he added a little dubiously. "It is usually the doctor's children who never get any medicine," chuckled Mr. Powers. "Now, I could do better than that for you. I could tell you considerable about beets if you urged me to." "I wish you would," answered the boys promptly. "There, you see, you urge me at once--you insist upon hearing! What can I do? There is no escape for me but to comply with your request. Of course I was not expecting to be called upon to speak to-day and therefore I must crave the indulgence of the audience if I am but poorly prepared," began Mr. Powers with mock gravity. "In the first place you must remember that while sugar-cane can only be cultivated in a hot, moist climate, beets grow best in the temperate zone. In the United States there is a belt of beet-sugar land two hundred miles wide that runs irregularly across the country from southern New England to the Pacific coast. Sugar-beets can, of course, be grown elsewhere, but it is in this particular region that they thrive best. If even a small proportion of this area were to be planted with beets we could get enough sugar from them to enable us to ship it to foreign markets instead of yearly importing a large amount of it. The trouble is that we Americans are so rich in land that we waste it and fail to get from it a tenth part of what we might. If you doubt that travel in Europe and see what is done with land on the other side; or, better yet, watch what some Italian in this country will get from a bit of land no bigger than your pocket handkerchief." Mr. Powers stopped a minute and looked out of the window. "The great objection our people make to growing beets is that they injure the soil so that nothing else planted afterward will flourish. Now to an extent this is true. Beets do run out the soil if they are raised year after year on the same land. If our farmers were not so slow to get a new idea they would raise beets in rotation as is done in Europe." "What do you mean by rotation?" demanded Bob. "A rotating crop is one that produces a sequence of different kinds of harvests," explained Mr. Powers. "By that I mean harvests of entirely varying nature. Abroad they have learned that a hoed crop, when planted annually, destroys the productivity of the earth; therefore foreigners plant beets one year in three or five and cereals, turnips, or something else in between times. Formerly they used to let the land lie fallow a year to rest it, but now they have worked out a scheme by which they get a crop every year. It was Napoleon, that Frenchman of wonderful brain, who first discovered the value of beets for making sugar, and thought out the plan for raising them in rotation with other varieties of crops. He commanded that ninety thousand acres of beets be planted in different parts of France, and he established in connection with this decree a great fund of money from which bonuses were to be paid to persons who built factories to manufacture beet-sugar. He went even further, furnishing free instruction to all who wished to learn the industry. In consequence at the end of a couple of years there were in France over three hundred small sugar factories; little by little this number has increased until now the sugar product of the French nation is enormous." Fascinated by the story Bob and Van listened attentively. "Didn't other countries steal the idea of the rotating crop?" inquired Van. "Not at first. Germany tried to make her farmers believe in the new notion, but failed," answered Mr. Powers. "Later, however, as an inducement, the German government helped beet-sugar factories pay such good prices for beets that the farmers became anxious to raise them; at the same time a high duty was placed on imported sugar, and the result was that the German people were forced to manufacture their own. At the present time about one-half of the sugar used by all the world is made in foreign factories. I myself run my beet farm on the rotation principle, and find that the hoed root crops seem to stimulate the others; but I can't convince my neighbors of it." "Does beet-sugar taste any different from cane?" inquired Bob. "Not a whit; you couldn't tell the difference," was Mr. Powers' answer. "I suppose sugar-beets are just like those in our gardens," ventured Van. "No, they're not; they are, however, not unlike them. They differ in having more juice and in usually being white," replied Mr. Powers. "The ground has first to be plowed and harrowed, and is afterward laid off in eighteen-inch rows because beets, you know, are planted from seed. When the crop comes up trouble begins, for it has to be thinned until each plant has a good area in which to grow; the beets must also be carefully weeded and the soil round them loosened if they are to thrive." "How long is it before they are ready for sugar making?" inquired Bob. "Practically five months; it depends somewhat on the season. When they are ripe they are dug up, the tops are removed, and they are floated down small canals where washing machines with revolving brushes remove from them every atom of dirt." "And then?" "If they are to be made directly into syrup and do not have to be shipped in bulk they go into slicers which cut them into V-shaped pieces about the length and thickness of a slate pencil, these pieces being called cossettes. The sliced beet-root is next put into warm water tanks in order that the sugar contained in it may be drawn out. Built in a circle, these tanks are connected, and as the beets move from one vat to another more and more sugar is taken from them until they reach the last vat when the beet pulp is of no further use except to be used as fodder for live stock. The juice remains in the tanks, and in color it is--" "Red!" cried Van, thoughtlessly interrupting. "No, son, not red. It is black as ink." "Black!" exclaimed the boys in a chorus. "Black as your shoe." "But--but I don't see how they--" Van stopped, bewildered. "They bleach it by injecting fumes of sulphur gas into the tanks; lime is also used to--" "To clear it after the dirt has come to the top," put in the boys in a breath. "Exactly so," laughed Mr. Powers. "I observe you are now at the home plate." [Illustration: "THESE TANKS ARE CONNECTED"] "We saw it done at the sugar-cane refinery," explained Bob. "I see," nodded Mr. Powers. "Well, the principle of making beet-sugar is the same as cane-sugar. By the use of chemical solutions the juice is cleared until it is perfectly white." Bob nudged Van with his elbow and the lads smiled understandingly. There was no danger of their forgetting Mr. Hennessey and his secret chemical formula. "The remainder of the process is also similar to that used in refining cane-sugar. The syrup passes from tank to tank, constantly thickening, and the molasses is extracted in the same fashion by being thrown off in the centrifugal machines when the sugar crystallizes. Molasses is often boiled two and three times to make second and third grade molasses for the trade, and you must remember in this connection that the names _New Orleans_ and _Porto Rico_ do not necessarily indicate where the product was made, but rather its quality, these varieties being of the finest grade." Mr. Powers rose and drew out a cigar. "I think I'm quite a lecturer, don't you?" he said. "I imagine your father, Van, could have told you this story much better than I have if you could have captured him for two hours on a train when he had nothing else to do. As it is I have had to fill his place, and I want you to inform him with my compliments that I am surprised to discover how completely he has neglected his son's education." With a mischievous twinkle in his eye Mr. Powers passed into the smoking-car. CHAPTER XII THE DAWN OF A NEW YEAR On their arrival at Denver Van and Bob were met by Mr. Blake, and a delay in the train admitted of a passing greeting between Mr. Powers and Van's father; afterward the heavy express that had safely brought the travelers to their journey's end thundered on its way and the boys were left on the platform. Mr. Blake regarded each of them keenly for a moment before speaking; then he extended his hand to Bob, saying: "The highest compliment I can pay you, young man, is to tell you you are like your father. Mrs. Blake and I are very grateful to you for what you've done for our son." "I'm afraid--" protested Bob. Mr. Blake cut him short. "There, there, we won't discuss it," said he. "I simply wish you to know that both of us have appreciated your friendship for Van. He is a scatter-brained young dog, but he is all we have, and we believe in time he is going to make good. Eh, son?" Despite the words he smiled down at the lad kindly. "I hope so, Father." "With a wise friend at your elbow it will be your own fault if you do not," his father declared. Summoning a porter to carry the luggage the trio followed him to the train which was to take them to the small town outside of Denver, where the Blakes resided. Here they found Van's mother--very beautiful and very young, it seemed to Bob; a woman of soft voice and pretty southern manner who seemed always to appear in a different gown and many floating scarfs and ribbons. Bob felt at a glance that she would not be the sort of person to pack boxes of goodies and send to her boy; she would always be too busy to do that. That she was, nevertheless, genuinely fond of Van there could be not the smallest doubt, and she welcomed both boys to the great stone house with true Virginian hospitality. To describe that western sojourn would be a book in itself. Bob wrote home to his parents volumes about his good times, and still left half the wonders of his Colorado visit untold. There was the trip up Pike's Peak; a two days' jaunt to a gold mine; a horseback ride to a large beet farm in an adjoining town; three weeks of real mountain camping, the joy of which was enhanced by the capture of a good sized bear. In addition to all this there were several fishing trips, and toward the close of the holiday a tour to the Grand Canyon. It was a never-to-be-forgotten vacation crowded with experiences novel and delightful. "I wonder, Van, how you can ever be content to leave all this behind and come East to school," remarked Bob to his chum when toward the last of September they once more boarded the train and turned their faces toward Colversham. "Oh, you see, Dad was born in the East, and he wanted me to have an eastern education," explained Van. "He laughs at himself for the idea though, and says it is only a sentimental notion, as he is convinced a western school would do exactly as well. He has lived out here twenty years now, and yet he still has a tender spot in his heart for New England. It is in his blood, he declares, and he can't get it out. Notwithstanding his love for the East, however, Mother and I say that wild horses couldn't drag him back there to live." "I suppose you wouldn't want to come East, either," Bob said. "Not on your life! Give me lots of hustle and plenty of room!" replied Van emphatically. "But I like the East and the eastern people, and I'll be almighty tickled to get back to Colversham and the fellows--to say nothing of Tim McGrew." "You'll take up football again this fall, of course," said Bob. "We'll both duff right in with the practice squad as soon as the boys get out; it seems to me there is no earthly reason why each of us shouldn't land somewhere on the eleven this year." Weeks afterward Bob thought with a grim smile of the remark. How different that fall term proved to be from anything he had expected! Colversham was reached without disaster and back into the chaos of trunks, suit-cases, and swarming arrivals came the western travelers. From morning until night a stream of boys crossed and recrossed the campus and the air was merry with such characteristic greetings as: "Ah, there, Blakie! How is the old scout?" "Snappy work, Bob Carlton! I say, you look pretty kippie. Where did you swipe the yellow shoes?" "Just wearing them temporarily until I can step into yours as stroke of the crew!" called back Bob good-naturedly. A shout went up from the boys who had heard the sally. For nearly a week the school grounds were a-hum with voices. Then things began to settle down into the regular yearly routine. In spite of the stiff program ahead Van managed to spend some part of each day, if only a few moments of it, with Tim McGrew. How much there was to tell! Three months had worked marvels in the little fellow and it was a pleasure to see how his strength was returning. "The doctor thinks there's a chance I may walk yet, Mr. Blake!" exclaimed the child. "He doesn't promise it, mind; he just says maybe things won't turn out as bad as we thought at first. I heard him tell Ma that perhaps later if I was to be operated on maybe I'd pull through and surprise everybody. Think of it! Think what it means to know there is even a chance. Wouldn't it be wonderful if I should walk again some time?" Catching the glow in the wistful face Van's own beamed. "You'll have us all fooled yet, Tim," he cried, "and be prancing round here like a young Kentucky colt--see if you don't." The lads chuckled together. Van was bubbling over with high spirits when he left Tim that afternoon and there was nothing to herald the approach of the calamity that fell like a thunderbolt upon him. It was late at night when the illness developed that so alarmed Bob Carlton that it sent him rushing to the telephone to call up the head master. From that moment on things moved with appalling rapidity. Van was carried from the dormitory to the school hospital and at the doctor's advice Mr. Carlton was summoned from New York by telephone. Within an incredibly few hours both he and his wife arrived by motor, and their first act was to wire Van's father. The boy was very ill, so ill that in an operation lay the one slender chance of saving his life. The case could brook no delay. There was not sufficient time to consult Van's father, or learn from him his preferences as to what should be done. To Mr. Carlton fell the entire responsibility of taking command of the perilous situation. He it was who secured the famous surgeon from New York; who sent for nurses and doctors; who made the decision that meant life or death to the boy who lay suffering on the cot in that silent room. How leaden were the hours while the lad's existence trembled in the balance! Mr. Carlton paced the floor of the tiny office, his hands clinched behind him and his lips tightly set. If Van did not survive his would be the word that had sent him to his end. Should the worst befall how should he ever greet that desperate father who was even now hurrying eastward with all the speed that money could purchase? What should he say? What could he say, Mr. Carlton asked himself. To lose his own child would be a grief overwhelming enough; but to have given the order that hurried another man's only boy into eternity--that would be a tragedy that nothing could ever make right. "I have done the best I knew," muttered Mr. Carlton over and over to himself. "I have done toward his son precisely as I would have done toward my own. Had I it all to decide over again I could do nothing different." Yet try as he would to comfort himself the hours before he could have tidings from the operating room dragged with torturing slowness. Bob, crouched in a chair in the corner of the room, dared not speak to his father. Never had he seen him so unnerved. There was no need to question the seriousness of the moment; it brooded in the tenseness of the atmosphere, in the speed with which his heart beat, in the drawn face of the man who never ceased his measured tread up and down the narrow room. And when the strain of the operation was actually over there was no lessening of anxiety, because for days following the battle for life had still to be waged. Would human strength hold through the combat? That was the question that filled the weary hours of the day and the sleepless watches of the night. Mr. Carlton, ordinarily so bound up in business affairs that he never could leave town, now gave not a thought to them. Instead he took up his abode in the dormitory with Bob that he might be close at hand, and here he eagerly checked off the successive hours that brought nearer that man who was racing against Fate across the vast breadth of the country. How would they meet, these two who had been so long divided by a gulf of years and bitterness? Would his former friend feel that the decisions he had made were wise, or would he heap reproaches upon him for putting in jeopardy a life over which he had no jurisdiction? With dread Mr. Carlton strove to put the thought of the coming interview out of his mind. "I have done as well as I knew," he reiterated. "Would that it had been my own boy instead of his!" Over and over he planned to himself what he would say at that crucial meeting. He would explain as nearly as he could the precise conditions that he felt justified him in assuming the immense financial responsibilities he had heaped up for his former friend. If the lad lived it would be worth it all; but if he did not it would all have gone for naught. Would not any father rather have had his child alive, invalid though he was, than to have lost him altogether? The meeting when it came was quite different from anything Mr. Carlton had outlined. It was after midnight when the special arrived at the dim little station, and even before the train came to a stop its solitary passenger sprang impatiently to the platform. There was no need for James Carlton to make certain who it was; every line of the form was familiar. He strode to the traveler's side. The hands of the two men shot out and met in a firm clasp. "The boy?" "He is alive, Asa." "God bless you, Jim!" Van Blake faced the great crisis, fought his way courageously through it, and won. Slowly he retraced his steps up the path to health again, and as soon as he was able to be moved he and his father and mother together with the Carltons went to Allenville and opened the old farmhouse for Christmas. What a Christmas it was! What a day of rejoicing and thanksgiving among young and old! Tim McGrew and all his family were brought down for a holiday, and there was a royal tree decked with candles and loaded with gifts; there was a pudding which could nowhere have been matched; a southern plum-pudding made by Van's mother; there were carols sung as only those to whom they meant much could sing them; and there was joy and peace in every heart. "Next summer it must be Colorado for you all, Jim," cried Asa Blake as he stood with his hand on the shoulder of his old partner. "We'll make this New Year the happiest of our lives. Tim shall go too; and if money can buy surgical skill he shall make the journey hither on his own two feet. Here's to the new year, Jim!" "The new year, Asa, and may God bless us every one!" echoed Mr. Carlton, softly. 
44284	----	Transcriber's Note: Minor typographical errors have been corrected without note. Irregularities and inconsistencies in the text have been retained as printed. Words printed in italics are noted with underscores: _italics_. REMINISCENCES OF GLASS-MAKING. BY DEMING JARVES. SECOND EDITION, ENLARGED. NEW YORK: PUBLISHED BY HURD AND HOUGHTON, 401 BROADWAY, COR. WALKER STREET. 1865. Entered according to Act of Congress, in the year 1865, by DEMING JARVES, in the Clerk's Office of the District Court of the District of Massachusetts. RIVERSIDE, CAMBRIDGE: PRINTED BY H. O. HOUGHTON AND COMPANY. PREFACE. The articles upon the history and progress of Glass Manufacture herein presented to the public were originally published in the columns of a village newspaper. They are the result of investigation upon these topics made in the few leisure moments gained from the engrossing cares of business, and consequently make no pretension to anything of literary character or execution. The object of the writer has been to gather, in a condensed form, whatever of interesting information could be gained from authentic sources, in regard to a branch of manufacture which has attained a position among the useful and elegant arts scarcely rivalled by any other of those which mark and distinguish the progressive character of our country. It is believed that they present, in a condensed and convenient form, much valuable information, useful alike for reference and instruction. Aside from historical or mechanical facts, there is much of romantic interest attaching to the progress of this department of art. The partiality of friends interested in the topics herein presented, rather than his own opinion of their value, has induced the writer to present the articles in a more permanent form. BOSTON, _March 17, 1854_. * * * * * The above was the Preface to a small pamphlet in 8vo. of the "Reminiscences of Glass-making," printed for private circulation in 1854, and now enlarged into a more permanent form, and brought down to the present year, in order to meet the demand for information which has unexpectedly sprung up from those interested in the manufacture of Glass in America. BOSTON, _January, 1865_. REMINISCENCES OF GLASS-MAKING. It may be safely asserted that no department of art has, from its earliest period, attracted so much attention and investigation, none involved so extensive a range of inquiry, or been productive of more ingenious, interesting, and beautiful results, than the manufacture of glass. The question of the origin of glass goes back to the remotest antiquity, and is involved in almost entire obscurity. All that modern writers on the subject are enabled to do, is to glean hints and indistinct statements in reference to the subject, from the very brief and unsatisfactory accounts of the ancients. These, however, throw but a feeble light upon the precise point of the origin of the manufacture; and little is proved beyond the fact of its great antiquity. That the subject held a very prominent place in the technological literature of the ancients is clearly proved; Pliny, Theophrastus, Strabo, Petronius Arbiter, Berzelias, Neri, Merrit, Runket, and others, referring constantly to it. The writings of all these demonstrate the deep interest existing upon the subject at their various times, but still fail to present us with any connected or detailed account of the rise and progress of the art. When it is considered that the elements involved in the manufacture of glass are derived from the earth,--not one of its components being in itself transparent, but earthy, opaque, and apparently incapable of being transmuted into a transparent and brilliant substance,--when it is considered that from these a material is produced almost rivalling the diamond in lustre and refractive power, and sometimes so closely resembling the richest gems as to detract from the value of the costliest; can it be wonderful that in the earliest ages the art was invested with a mysterious interest attaching to no other mechanical department? From the earliest periods, up to the eighteenth century, the art, from the peculiar knowledge and skill involved, could only minister to the wants or pleasures of the luxurious rich. The rarity of the material rendered the articles greatly valuable, as tasteful ornaments of dress or furniture; indeed, it is well known that the glass of Venice, at one period, was as highly valued as is the plate of the present day; and the passion for possessing specimens, promised in England, at least, to excite a spirit of speculation fully rivalling that exhibited in the tulip mania, so ridiculous, as well as ruinous, in Holland. It has been reserved for the present age, however, to render the art of glass-making tributary to the comfort of man,--to the improvement of science,--and by its moderate cost to enable the poorest and humblest to introduce the light and warmth of the sun within, while excluding the storms and chilly blasts; to decorate his table with the useful, and minister to his taste, at a cost barely more than that of one of his ordinary days' labor. That which once was prized and displayed as the treasure and inheritance of the wealthy, and which, with sacred carefulness, was handed down as of precious value, may now be found in the humblest dwellings, and is procured at a charge which makes the account of the former costliness of glass to partake almost of the character of the fabulous and visionary. That the art of glass manufacture is destined to greater progress and higher triumphs cannot for a moment be doubted; and the time will arrive when, from increased purity of materials and progressive chemical development, the present position of the art will fall comparatively into the shade. It is no undue stretch of the imagination to conceive that lenses shall be perfected whose purity will enable the astronomer to penetrate the remotest region of space; new worlds may perhaps be revealed, realizing all that the "moon hoax" promised-- "The spacious firmament on high, With all the blue ethereal sky And spangled heavens"---- be read as a book, and man perhaps recognize man in other worlds than his own. It may be that in its triumphs it is destined to concentrate the rays of the sunlight, and make the eye to pierce into the secrets and deep places of the sea, "Full many a fathom deep." Man may be enabled to read the wonders and the hidden works of the Almighty; it may be, that the power of the traditional lens of Archimedes upon the fleet of Marcellus shall be realized, in the absorbing and igniting, and perhaps useful power of some feature of its progress; and in its sphere, the art become fruitful in practical results, rivalling the highest attainments in the department of scientific progress. It is no visionary speculation to believe, that, by the aid of machinery, it may be readily rolled into sheets, as is iron or lead now in use. It will minister more and more to the necessities and comfort of mankind, and contribute largely to the many and various manufacturing purposes of the age. That its practical adaptations are not already known or exhausted, cannot be doubted; and its applicability, in some cheaper form, for vessels of large size and certain shape, and (strange as it may seem) for tessellated and ordinary flooring and pavements, are among the results which we think yet to be demonstrated in its progress. An elegant writer, in a late number of "Harper's Magazine," says:-- "The importance of glass, and the infinite variety of objects to which it is applicable, cannot be exaggerated; indeed, it would be extremely difficult to enumerate its properties, or estimate adequately its value. This, then, transparent substance, so light and fragile, is one of the most essential ministers of science and philosophy, and enters so minutely into the concerns of life that it has become indispensable to the daily routine of our business, our wants, and our pleasures. It admits the sun and excludes the wind, answering the double purpose of transmitting light and preserving warmth; it carries the eye of the astronomer to the remotest regions of space; through the lenses of the microscope it develops new worlds of vitality, which, without its help, must have been but imperfectly known; it renews the sight of the old, and assists the curiosity of the young; it empowers the mariner to descry distant ships, and trace far off shores; the watchman on the cliff to detect the operations of hostile fleets and midnight contrabandists, and the lounger in the opera to make the tour of the circles from his stall; it preserves the light of the beacon from the rush of the tempest, and softens the flame of the lamp upon our tables; it supplies the revel with those charming vessels in whose bright depths we enjoy the color as well as the flavor of our wine; it protects the dial whose movements it reveals; it enables the student to penetrate the wonders of nature, and the beauty to survey the marvels of her person; it reflects, magnifies, and diminishes; as a medium of light and observation its uses are without limit, and as an article of mere embellishment, there is no form into which it may not be moulded, or no object of luxury to which it may not be adapted." In contrast with the foregoing, we will make one more extract, from an English writer of ancient date. Holinshed, in his "Chronicles," published during the reign of Elizabeth, says:-- "It is a world to see in these our days, wherein gold and silver aboundeth, that our gentility, as loathing these metals, (because of the plenty,) do now generally choose rather the Venice Glasses, both for our wine and beer, than any of these metals, or stone, wherein before time we have been accustomed to drink; but such is the nature of man generally, that it most coveteth things difficult to be attained; and such is the estimation of this stuff, that many become rich only with their new trade into Murana, (a town near to Venice,) from whence the very best are daily to be had, and such as for beauty do well near match the Crystal or the ancient Murrhina Vase, whereof now no man has knowledge. And as this is seen in the gentility, so in the wealthy commonality the like desire of glasses is not neglected, whereby the gain gotten by their purchase is much more increased, to the benefit of the merchant. The poorest endeavor to have glasses also if they may; but as the Venetian is somewhat too dear for them, they content themselves with such as are made at home of fern and burnt stone; but in fine, all go one way, that is to the shades, at last." PROPERTIES OF GLASS. Glass has properties peculiarly its own; one of which is that it is of no greater bulk when hot, or in the melted state, than when cold. Some writers state that it is (contrary to the analogy of all other metals) of greater bulk when cold than when hot. It is transparent in itself; but the materials of which it is composed are opaque. It is not malleable, but in ductility ranks next to gold. Its flexibility, also, is so great that when hot it can be drawn out, like elastic thread, miles in length, in a moment, and to a minuteness equal to that of the silk-worm. Brittle, also, to a proverb, it is so elastic that it can be blown to a gauze-like thinness, so as easily to float upon the air. Its elasticity is also shown by the fact that a globe, hermetically sealed, if dropped upon a polished anvil, will recoil two thirds the distance of its fall, and remain entire until the second or third rebound. (The force with which solid balls strike each other may be estimated at ten, and the reaction, by reason of the elastic property, at nine.) Vessels, called bursting-glasses, are made of sufficient strength to be drawn about a floor; a bullet may be dropped into one without fracture of the glass; even the stroke of a mallet sufficiently heavy to drive a nail has failed to break such glasses. In a word, ordinary blows fail to produce an impression upon articles of this kind. If, however, a piece of flint, cornelian, diamond, or other hard stone, fall into one of these glasses, or be shaken therein a few moments, the vessel will fly into a myriad of pieces. Glass of the class called Prince Rupert Drops exhibits another striking property. Let the small point be broken, and the whole flies with a shock into powder. Writers have endeavored to solve the philosophy of this phenomenon; some by attributing it to percussion putting in motion some subtle fluid with which the essential substance of glass is permeated, and thus the attraction of cohesion being overcome. Some denominate the fluid electricity, and assert that it exists in glass in great quantities, and is capable of breaking glass when well annealed. These writers do not appear to have formed any conclusion satisfactory to themselves, and fail to afford any well-defined solution to the mystery. Another phenomenon in connection with glass tubes is recorded in the "Philosophical Transactions," No. 476:-- "Place a tube, say two feet long, before a fire, in a horizontal position, having the position properly supported, say by putting in a cork at each end supported by pins for an axis; the rod will acquire a rotary motion round the axis, and also a progressive motion towards the fire, even if the supporters are declined from the fire. When the progressive motion of the tube towards the fire is stopped by any obstacle, the rotation is still continued. When the tubes are placed in nearly an upright position, leaning to the right hand, the motion will be from east to west; but if they lean to the left hand, their motion will be from west to east; and the nearer they are placed to an upright position the less will be their motion either way. If the tubes be placed on a sheet of glass, instead of moving towards the fire they will move from it, and about the axis in a contrary direction from what they did before; nay, they will recede from the fire, and move a little upwards when the plane inclines towards the fire." Glass is used for pendulums, as not being subject to affections from heat or cold. It is, as is well known, a non-conductor. No metallic condenser possesses an equal power with one of glass. In summer, when moisture fails to collect on a metallic surface, open glass will gather it on the exterior; the slightest breath of air evidently affecting the glass with moisture. Dew will affect the surface of glass while apparently uninfluential upon other surfaces. The properties of so-called "musical glasses" are strikingly singular. Glass bowls, partly filled with water, in various quantity, will, as is well known, emit musical sounds, varying with the thickness of their edges or lips. When rubbed, too, with a wet finger, gently, the water in the glass is plainly seen to tremble and vibrate. Bells manufactured of glass have been found the clearest and most sonorous; the vibration of sound extending to a greater degree than in metallic bells. Glass resists the action of all acids except the "fluoric." It loses nothing in weight by use or age. It is more capable than all other substances of receiving the highest degree of polish. If melted seven times over and properly cooled in the furnace, it will receive a polish rivalling almost the diamond in brilliancy. It is capable of receiving the richest colors procured from gold or other metallic coloring, and will retain its original brilliancy of hue for ages. Medals, too, embedded in glass, can be made to retain forever their original purity and appearance. Another singular property of glass is shown in the fact, that when the furnace, as the workmen term it, is settled, the metal is perfectly plain and clear; but if by accident the metal becomes too cool to work, and the furnace heat required to be raised, the glass, which had before remained in the open pots perfectly calm and plain, immediately becomes agitated or boiling. The glass rises in a mass of spongy matter and bubbles, and is rendered worthless. A change is however immediately effected by throwing a tumbler of water upon the metal, when the agitation immediately ceases, and the glass assumes its original quiet and clearness. All writers upon the subject of glass manufacture fail to show anything decisive upon the precise period of its invention. Some suppose it to have been invented before the flood. Nervi traces its antiquity to the yet problematical time of Job. It seems clear, however, that the art was known to the Egyptians thirty-five hundred years since; for records handed down to us in the form of paintings, hieroglyphics, &c., demonstrate its existence in the reign of the first Osirtasen, and existing relics in glass, taken from the ruins of Thebes, with hieroglyphical data, clearly place its antiquity at a point fifteen centuries prior to the time of Christ. Mr. Kennett Loftus, the first European who has visited the ancient ruins of Warka, in Mesopotamia, writes thus: "Warka is no doubt the Erech of Scripture, the second city of Nimrod, and it is the Orchoe of the Chaldees. The mounds within the walls afford subjects of high interest to the historian; they are filled, or I may say composed, of coffins piled upon each other to the height of forty-five feet." "The coffins are of baked clay, covered with green glaze, and embossed with the figures of warriors, &c., and within are ornaments of gold, silver, iron, copper, and _glass_." Layard, in his discoveries among the ruins of Nineveh and Babylon, in chapter 8th, says: "In this chamber were found two entire glass bowls, with fragments of others. The glass, like all others that come from the ruins, is covered with pearly scales, which, on being removed, leave prismatic, opal-like colors of the greatest brilliancy, showing, under different lights, the most varied tints. This is a well-known effect of age arising from the decomposition of certain component parts of the glass. These bowls are probably of the same period as the small bottle found in the ruins of the northwest palace during the previous excavations, and now in the British Museum. On this highly interesting relic is the name of Sargon, with his title of King of Assyria, in cuneiform characters, and the figure of a lion. We are therefore able to fix its date to the latter part of the seventh century B.C. It is consequently the most ancient known specimen of _transparent_ glass." In chapters 22d and 25th, he gives us the form of many glass vessels from the mound of Babel, similar in form to the modern fish-globes, flower-vases and table water-bottles of the present day--the latter being reeded must have been formed in metallic moulds--and pieces of glass tubes, the exterior impression exactly like our modern patch diamond figure. Of the several specimens of glass brought to England by Mr. Layard, one, the fragment of a vase, when examined, was of a dull green color, as though incrusted with carbonate of copper. This color was quite superficial, and the glass itself was opaque and of a vermilion tint, attributed to suboxide of copper. The outer green covering was due to the action of the atmosphere on the surface of the glass, and the consequent change of the suboxide into green carbonate of copper. This specimen is interesting, as showing the early use and knowledge of suboxide of copper as a stain or coloring agent for glass. The ancients employed several substances in their glass, and colored glazes for bricks and pottery, but of which there remains no published record. But these glasses and other ancient works of art prove that they were familiar with the use of oxide of lead as a flux in their vitreous glasses, and with stannic acid and Naples yellow as stains or pigments. Other writers believe that glass was in more general use in the ancient than in comparatively modern times, and affirm that among the Egyptians it was used even as material for coffins. It is certainly true that so well did the Egyptians understand the art, that they excelled in the imitation of precious stones, and were well acquainted with the metallic oxides used in coloring glass; and the specimens of their skill, still preserved in the British Museum and in private collections, prove the great skill and ingenuity of their workmen in mosaic similar in appearance to the modern paper-weights. Among the specimens of Egyptian glass still existing is a fragment representing a lion in bas-relief, well executed and anatomically correct. Other specimens are found inscribed with Arabic characters. All writers agree that the glass-houses in Alexandria, in Egypt, were highly celebrated for the ingenuity and skill of their workmen, and the extent of their manufactures. Strabo relates that the Emperor Hadrian received from an Egyptian priest a number of glass cups in mosaic, sparkling with every color, and deemed of such rare value that they were used only on great festivals. The tombs at Thebes, the ruins of Pompeii and Herculaneum, and the remains of the villa of the Emperor Tiberius, go not only incidentally to establish the antiquity of the art, but also prove the exquisite taste and skill of the artists of their various periods. The first glass-houses, well authenticated, were erected in the city of Tyre. Modern writers upon the subject generally refer to Pliny in establishing the fact that the Phoenicians were the inventors of the art of glass-making. The tradition is that the art was originally brought to light under the following circumstances. A vessel being driven by a storm to take shelter at the mouth of the river Belus, the crew were obliged to remain there some length of time. In the process of cooking, a fire was made upon the ground, whereon was abundance of the herb "kale." That plant burning to ashes, the saline properties became incorporated with the sand. This causing vitrification, the compound now called glass was the result. The fact becoming known, the inhabitants of Tyre and Sidon essayed the work, and brought the new invention into practical use. This is the tradition: but modern science demonstrates the false philosophy, if not the incorrectness, of Pliny's account; and modern manufacturers will readily detect the error, from the impossibility of melting silex and soda by the heat necessary for the ordinary boiling purposes. It is a well-authenticated fact, however, that there were whole streets in Tyre entirely occupied by glass-works; and history makes no mention of any works of this character at an earlier period than the time mentioned by Pliny. That Tyre possessed peculiar advantages for the manufacture, is very clear from geographical and geological data, the sand upon the shore at the mouth of the river Belus being pure silica, and well adapted to the manufacture. The extensive range of Tyrian commerce, too, gave ample facilities for the exportation and sale of the staple; and for some ages it must have constituted almost the only article, or at least the prominent article, of trade. Doubtless the rich freights of "the ships of Tyre," mentioned in Scripture, may in part have been composed of a material now as common as any of its original elements. From Tyre and Sidon the art was transferred to Rome. Pliny states it flourished most extensively during the reign of Tiberius, entire streets of the city being then occupied by the glass manufactories. From the period of Tiberius the progress of the art seems more definite and marked, both as relates to the quantity and mode of manufacture. It was during the reign of Nero, so far as we can discover, that the first perfectly clear glass, resembling crystal, was manufactured. Pliny states that Nero, for two cups of ordinary size, with handles, gave six thousand sestertia, equal in our currency to about two hundred and fifty thousand dollars; and that rich articles of glass were in such general use among the wealthy Romans as almost to supersede articles of gold and silver. The art, however, at that period, seems to have been entirely devoted to articles of luxury, and from the great price paid, supported many establishments,--all however evidently upon a comparatively small scale, and confined, as it would appear, to families. Up to this period, no evidence appears to prove that any other than colored articles in glass-ware were made. It is clear, too, that the furnaces and melting-pots then in use were of very limited capacity, the latter being of crucible shape; and it was not until the time of Nero that the discovery was made that muffled crucibles or pots, as at the present day, were required in order to make crystal glass. (Without them, it is well known, crystal glass cannot be perfected.) It appears, further, that a definite street in the city of Rome was assigned to the manufacturers of this article; and that in the reign of Severus they had attained such a position, and accumulated wealth to such a degree, that a formal tax was levied upon them. Some writers take the ground that this assessment was the primary cause of the transfer of the manufacture to other places. That the peculiar property of the manufacture at this period was its clear and crystal appearance is abundantly evident; and this, and the great degree of perfection to which the manufacture of white or crystal-like glass was carried, are by many writers thought to have been proved from classical sources,--Horace and Virgil both referring to it, the one speaking of its beautiful lustre and brilliancy, the other comparing it to the clearness of the waters of the Fucine Lake. The decline of this art in Rome is clearly defined by various writers; and its gradual introduction into Bohemia and Venice is plainly marked out. At this latter place the art flourished to a remarkable degree, and being marked by constant progress and improvement, enabled Venice to supply the world without a rival, and with the beautiful manufacture called "Venice drinking-cups." The beauty and value of these are abundantly testified to by many authors, among whom is Holinshed, referred to previously. The manufacture of these and similar articles were located, as stated in the "Chronicles," at Murano, a place about one mile from the city, where the business was carried on, and assumed a high position in the order of the arts. And from thence we are enabled to date its future progress and gradual introduction into Europe, Germany, England, and the Western World. It is not strange that the strict secrecy with which the business was conducted in these times, should have invested the art with an air of romance; and legends, probably invented for the purpose, created a maximum of wonder among the uninitiated. The government of Venice also added, by its course, to the popular notions regarding the high mystery of the art, conferring, as it did, the title of "Gentleman" (no idle title in those days) on all who became accomplished in the manufacture. Howell, in his "Familiar Letters," dated from Venice in 1621, says: "Not without reason, it being a rare kind of knowledge and chemistry, to transmute the dull bodies of dust and sand, for they are the only ingredients, to such pellucid, dainty body, as we see crystal glass is." That the art had greatly improved in the hands of the Venetian artisans cannot be doubted. The manufacture was carried to a degree far beyond any previous period; and the more so, because sustained by the governmental protection and patronage. Venice being then in the height of her commercial glory, she herself being "Queen of the Sea," ample facilities existed for the exportation of her manufactures to every part of the known world; and for a long period she held the monopoly of supplying the cities of Europe with crystal glass in its various departments of ornament and utility. A French writer, who published an elaborate work in twelve books upon the subject of glass manufacture, after it had been introduced into France, gives an interesting account of the rise and progress of the art in that country, the encouragement it received, and the high estimation in which it was held. After stating that it was introduced into France from Venice, he says:-- "The workmen who are employed in this noble art are all gentlemen, for they admit none but such. They have obtained many large privileges, the principal whereof is to work themselves, without derogating from their nobility. Those who obtained these privileges first were gentlemen by birth; and their privilege running, that they may exercise this art without derogating from their nobility, as a sufficient proof of it, which has been confirmed by all our kings; and in all inquiries that have been made into counterfeit nobilities, never was any one attainted who enjoyed these privileges, having always maintained their honor down to their posterity." Baron Von Lowhen states, in his "Analysis of Nobility in its Origin," that, "So useful were the glass-makers at one period in Venice, and so considerable the revenue accruing to the republic from their manufacture, that, to encourage the men engaged in it to remain in Murano, the Senate made them all Burgesses of Venice, and allowed nobles to marry their daughters; whereas, if a nobleman marries the daughter of any other tradesman, the issue is not reputed noble." From this statement a valuable lesson can be drawn, viz., that a strict parallel is constantly observable between the progress of this art and the intellectual and social elevation of its possessors. Those engaged in it now do not indeed occupy the same social position; still it is probable that in foreign lands the blood of noble ancestors still runs in their veins; and even in our own democratical land, with all the tendencies of its institutions, workers in glass claim a distinctive rank and character among the trades; and in the prices of labor, and the estimate of the comparative skill involved, are not controlled by those laws of labor and compensation which govern most other mechanical professions; and similarity of taste and habit is in a degree characteristic of the modern artisan in this department, as in the case of those who, for their accomplishment in the art, were ennobled in the more remote period of its progress. The same writer says:-- "It must be owned those great and continual heats, which those gentlemen are exposed to from their furnaces, are prejudicial to their health; for, coming in at their mouths, it attacks their lungs and dries them up, whence most part are pale and short-lived, by reason of the diseases of the heart and breast, which the fire causes; which makes Libarius say, 'they were of weak and infirm bodies, thirsty, and easily made drunk,'--this writer says, this is their true character: but I will say this in their favor, that this character is not general, having known several without this fault." Such was the character and habits of noble glass-makers four hundred years since; and whether their descendants still retain their blood or not, the habit of drinking, believed at that time necessary as consequent upon the nature of the employment, is, at the present day, confined to the ignorant, dissolute, and unambitious workmen. The habit will, doubtless, ere long be done away. Still, so long as the workmen of the present day cling to their conventional rules,--act as one body, the lazy controlling the efforts of the more intelligent and industrious,--so long will the conduct of the dissolute few affect the moral reputation of the entire body. They must not forget the old adage, that "One bad sheep taints the whole flock." The spirit of the age in no degree tends to sustain the old saying, that "Live horses must draw the dead ones." The writer already referred to, dwelling with great interest upon the social position of those then engaged in the art, goes on to say:-- "Anthony de Brossard, Lord of St. Martin and St. Brice, gentleman to Charles d'Artois, Count of Eu, a prince of noble blood royal, finding this art so considerable, that understanding it did not derogate from their nobility, obtained a grant in the year 1453 to establish a glass-house in his country, with prohibition of any other, and several other privileges he had annexed to it. The family and extraction of this Sieur de Brossard was considerable enough to bring him here as an example. The right of making glass being so honorable, since the elder sons of the family of Brossard left it off, the younger have taken it up, and continue it to this day. Messieurs de Caqueray, also gentlemen of ancient extraction, obtained a right of glass-making, which one of their ancestors contracted by marriage in the year 1468 with a daughter of Anthony de Brossard, Lord of St. Martin, that gentleman giving half of his right for part of her fortune, which was afterwards confirmed in the Chamber of Accounts. Messieurs Valliant, an ancient family of gentlemen, also obtained a grant of a glass-house for recompense of their services, and for arms a Poignard d'Or on azure, which agrees with their name and tried valor. Besides these families, who still continue to exercise this art, there are the Messieurs de Virgille, who have a grant for a little glass-house. Messieurs de la Mairie, de Suqrie, de Bougard, and several others, have been confirmed in their nobility during the late search in the year 1667. "We have, moreover, in France, several great families, sprung from gentlemen glass-makers who have left the trade, among whom some have been honored with the purple and the highest dignities and offices." Enough is recorded to show in what estimation the art was held in France by the government and people of that period; and it is in nowise wonderful that an art invested with so much distinction, conducted with so much secrecy, and characterized with so great a degree of romantic interest, should have given rise to strange reports and legends, hereafter to be referred to. The writer referred to above states that there were two modes of manufacturing glass. One he denominates that of the "Great Glass-Houses," the other the "Small Glass-Houses." In the large houses the manufacture of window-glass, and bottles for wine or other liquors, was carried on. He states:-- "The gentlemen of the Great Glass-Houses work only twelve hours, but that without resting, as in the little ones, and always standing and naked. The work passes through three hands. First, the gentlemen apprentices gather the glass and prepare the same. It is then handed to the second gentlemen, who are more advanced in the art. Then the master gentleman takes it, and makes it perfect by blowing it. In the little glass-houses, where they make coach-glasses, drinking-glasses, crystals, dishes, cups, bottles, and such like sort of vessels, the gentlemen labor but six hours together, and then more come and take their places, and after they have labored the same time they give places to the first; and thus they work night and day, the same workmen successively, as long as the furnace is in a good condition." Every glass-maker will perceive, from the foregoing description, that the same system prevails at the present time, as to the division of labor and period of labor, so far at least as "blown articles" are concerned. The names, too, then given to glass-makers' tools are retained to the present day, and, with slight difference, the shapes of the various tools are the same. At the best, the manufacturers of glass in France were for a long period much inferior to the Venetians and Bohemians; but after the introduction of window-glass, from Venice, the making of crystal glass greatly extended and correspondingly improved. In the year 1665 the government of France, desirous of introducing the manufacture of window-glass, offered sufficient inducement in money and privileges to a number of French artists (who had acquired the process at Murano, at Venice) to establish works at Tourtanville. At these works the same system of blowing was followed as that used in the Venetian glass-works. A workman, under this system, named Thevart, discovered the art of casting plate-glass, and obtained from the government a patent for the term of thirty years. He erected extensive works in Paris, and succeeded in what was then deemed an extraordinary feat, casting plates eighty-four inches by fifty inches, thereby exciting unbounded admiration. The credit of the invention of casting plates of glass belongs to France, and the mode then adopted exists at the present day, with but slight variation. France monopolized the manufacture over one hundred years before it was introduced into any other country. Writers generally agree that the manufacture of glass was introduced into England in the year 1557. "Friars' Hall," as stated by one writer, was converted into a manufactory of window-glass,--other writers say, for crystal glass, (called by the English "flint," from the fact of the use of flint-stones, which, by great labor, they burnt and ground.) In 1575 Friars' Hall Glass-Works, with forty thousand billets of wood, were destroyed by fire. In 1635, seventy-eight years after the art was introduced into England, Sir Robert Mansell introduced the use of coal fuel instead of wood, and obtained from the English government the monopoly of importing the fine Venetian drinking-glasses, an evidence that the art in England was confined as yet to the coarser articles. Indeed, it was not until the reign of William III. that the art of making Venetian drinking-vessels was brought into perfection,--quite a century after the art was introduced into England; an evidence of the slow progress made by the art in that country. As France was indebted to Venice for her workmen, so also was England indebted to the same source. Howell, in one of his "Familiar Letters," directed to Sir Robert Mansell, Vice-Admiral of England, says: "Soon as I came to Venice, I applied myself to dispatch your business according to instruction, and Mr. Seymour was ready to contribute his best furtherance. These two Italians are the best gentlemen workmen that ever blew crystal. One is allied to Antonio Miotte, the other is cousin to Maralao." Although Sir Robert procured workmen from Venice, they were probably of an inferior character, and a space of fifty years elapsed before the English manufactories equalled the Venetian and French in the quality of their articles. Evelyn, in his "Diary," states: "On the proclamation of James II., in the market-place of Bromley, by the sheriff of Kent, the commander of the Kentish troops, two of the King's trumpeters, and other officers, drank the King's health in a flint wine-glass three feet tall." In the year 1670, the Duke of Buckingham became the patron of the art in England, and greatly improved the quality and style of the flint-glass, by procuring, at great personal expense, a number of Venetian artists, whom he persuaded to settle in London. From this period, _i.e._, about the commencement of the eighteenth century, the English glass manufactories, aided by the liberal bounties granted them in cash upon all glass exported by them or sold for export, became powerful and successful rivals of the Venetian and the French manufactories in foreign markets. The clear bounty granted on each pound of glass exported from England, which the government paid to the manufacturer, was not derived from any tax by impost or excise previously laid, for all such were returned to the manufacturer, together with the bounty referred to; thereby lessening the actual cost of the manufacture from twenty-five to fifty per cent., and enabling the English exporters to drive off all competition in foreign markets. This bounty provision was annulled during the Premiership of Sir Robert Peel, together with all the excise duty on the home consumption. In 1673 the first plate-glass was manufactured at Lambeth, under a royal charter; but no great progress was made at that time, and the works for the purpose were doubtless very limited. One hundred years later, _i.e._ 1773, a Company was formed, under a royal charter, called the "Governor and Company of the British Cast Plate-Glass Manufactory," with a capital of eighty shares of five hundred pounds each, their works being at Ravenshead, in Lancashire. These works have been very successfully conducted, and, according to a late writer, are rivalled by none, excepting those at "St. Gobain," in France. Since the excise duty on plate-glass has been repealed, its manufacture has increased to a wonderful extent; the quantity used in the construction of the Crystal Palace, for the World's Fair, being probably many times larger than that manufactured twenty years since in the kingdom of Great Britain in any one year. An English paper states that Roger Bacon, at sixty-four years of age, was imprisoned ten years for making concave and convex glasses, and camera-obscura and burning-glasses. It is to many persons matter of great surprise that the manufacture of plate-glass has never been introduced into this country. The whole process is a simple one. The materials are as cheap here as in England or in France. Machinery for the polishing of the surface is as easily procured, and water-power quite as abundant, as in either country. The manufacture, with the materials so ready to the hand, and these together with the skill, labor, and demand, increasing every year, is most certain to realize a fair remunerating profit and steady sale. Besseman has lately introduced a new method of casting plate-glass, which, should it equal the inventor's expectation, will reduce the cost, supersede the old plan, and eventually, of course, increase the consumption. CURIOSITIES OF GLASS-MAKING. We gather from the ancient writers on glass-making, that the workers in the article had, at a very early period, arrived at so great a degree of proficiency and skill as to more than rival, even before the period of the Christian era, anything within the range of more modern art. The numerous specimens of their workmanship, still preserved in the public institutions of Europe, and in the cabinets of the curious, prove that the art of combining, coloring, gilding, and engraving glass was perfected by the ancients. Indeed, in fancy coloring, mosaic, and mock gems or precious stones, the art of the ancients has never been excelled. Among the numerous specimens it is remarkable that all vessels are round; none of ancient date are yet found of any other form. And no specimen of crystal glass of ancient date has yet been found. Among the numerous antiques yet preserved, the "Portland Vase" must hold the first place. Pellat, in his work on the incrustation of glass, states: "The most celebrated antique glass vase is that which was during more than two centuries the principal ornament of the Barberini Palace, and which is now known as the 'Portland Vase.' It was found about the middle of the sixteenth century, enclosed in a marble sarcophagus within a sepulchral chamber, under the Monte del Garno, two and a half miles from Rome, in the road to Frascati. It is ornamented with white opaque figures in bas-relief upon a dark blue transparent ground. The subject has not heretofore received a satisfactory elucidation, but the design and more especially the execution are admirable. The whole of the blue ground, or at least the part below the handles, must have originally been covered with white enamel, out of which the figures have been sculptured in the style of a cameo, with most astonishing skill and labor." The estimation in which the ancient specimens of glass were held, is demonstrated by the fact that the Duchess of Portland became the purchaser of the celebrated vase which bears her name, at a price exceeding nine thousand dollars, and bore away the prize from numerous competitors. The late Mr. Wedgwood was permitted to take a mould from the vase, at a cost of twenty-five hundred dollars, and he disposed of many copies, in his rich china, at a price of two hundred and fifty dollars each. The next specimen of importance is the vase exhumed at Pompeii in 1839, which is now at the Museum at Naples. It is about twelve inches high, eight inches in width, and of the same style of manufacture with the "Portland Vase." It is covered with figures in bas-relief raised out of a delicate white opaque glass, overlaying a transparent dark blue ground, the figures being executed in the style of cameo engraving. To effect this, the manufacturer must have possessed the art of coating a body of transparent blue glass with an equal thickness of enamel or opal-colored glass. The difficulty of tempering the two bodies of glass with different specific gravities, in order that they may stand the work of the sculptor, is well known by modern glass-makers. This specimen is considered by some to be the work of Roman artists; by others it is thought to be of the Grecian school. As a work of art it ranks next to the "Portland Vase," and the figures and foliage, all elegant and expressive, and representative of the season of harvest, demonstrate most fully the great artistic merit of the designer. THE ROYAL CLARENCE VASE. William Hone, in his "Day-Book" for 1831, says, "This superb glass vase, designed by John Gunby, and exhibited at the Queen's Bazaar, Oxford Street, London, is an immense basin of copper, and its iron shaft or foot clothed with two thousand four hundred pieces of glass, construct a vase fourteen feet high and twelve feet wide across the brim, weighing upwards of eight tons, and capable of holding eight pipes of wine. Each piece of glass is richly cut with mathematical precision and beautifully colored; the colors are gold, ruby, emerald, &c.; the colored pieces being cemented upon the metal body and rendered air-tight. The exterior is a gem-like surface of inconceivable splendor; on a summer afternoon it forms a mass of brilliancy. The vase, by illumination of gas alone, glittered like diamonds upon melted gold. Mr. Reingale says the human mind, in all of its extensive range of thought, is not able to conceive a splendid glass vase cut in a more elaborate and novel way. At the first sight one is confounded with astonishment, and knows not whether what we see is real, or whether on a sudden we have not been transported to another globe. To England is due the honor of its production, and it comes from the hands of one of its numerous celebrated artists, Mr. Gunby. The precious metal, gold, glitters in all its glory, intermixed, or rather united with extraordinary beauty of cutting and rich and splendid enamelled painting. One is at a loss whether most to admire the shape, the gorgeous brilliancy, the sparkle of the gems, the beauty of the cutting, the enamelling, the general conception, or the immense bulk of this magnificent and astounding work of art." The "Scientific American" states, "The troupe of glass-blowers at Hope Chapel furnish a very interesting evening's entertainment for those who are fond of practical things. A steam-engine, most beautifully constructed of different colored glass, is worked by steam all the time. The nature of the material affords an opportunity to see all the several parts moving at once, and it is really a very curious sight, even to an engineer, and one that will well repay a visit." Among the numerous specimens of ancient glass now in the British Museum, there are enough of the Egyptian and Roman manufacture to impress us with profound respect for the art as pursued by the earlier workers in glass. Among them is a fragment considered as the _ne plus ultra_ of the chemical and manipulatory skill of the ancient workers. It is described as consisting of no less than five layers or strata of glass, the interior layer being of the usual blue color, with green and red coatings, and each strata separated from and contrasted with the others by layers of white enamel, skilfully arranged by some eminent artist of the Grecian school. The subject is a female reposing upon a couch, executed in the highest style of art. It presents a fine specimen of gem engraving. Among the articles made of common material are a few green vases about fifteen inches high, in an excellent state of preservation, and beautiful specimens of workmanship. In the formation of the double handles and curves, these vases evince a degree of skill unattained by the glass-blowers of the present period. The cases in the Egyptian room at the Museum contain several necklaces, small figures, scarabæi, and other objects, which would appear to an ordinary observer to be composed of precious stones. They are, in fact, at least most of them, formed either of glass throughout the whole substance, or of materials covered with a glass coating. The manufacture of articles of this description presupposes a market for them; and the desire upon the part of the less affluent members of society to possess, at a cheap rate, ornaments in imitation of their superiors, necessarily leads to the conclusion that, even at the most ancient of the periods I have mentioned, the Egyptians had made a remarkable advance in the customs of civilized life. The Museum cases also exhibit networks of glass bugles, with which the wrappers of mummies were often decorated; and there is abundance of evidence to show that wine was frequently served at table in glass bottles and cups. Alexander the Great is said to have been buried at Alexandria in a coffin composed wholly of glass. The specimens taken from the tombs at Thebes are also numerous. Their rich and varied colors are proofs of the chemical and inventive skill of the ancients. These specimens embrace not only rich gems and mosaic work, but also fine examples of the lachrymatory vase. Some of the vases are made from common materials, with very great skill and taste. The specimen of glass coin, with hieroglyphical characters, must not be omitted; as also a miniature effigy of the Egyptian idol "Isis"; a specimen of which proves that the Egyptians must have been acquainted with the art of _pressing_ hot glass into metallic moulds, an art which has been considered of modern invention. English glass-makers considered the patent pillar glass a modern invention until a Roman vase was found (it is now to be seen in the Polytechnic Institution in London), being a complete specimen of pillar moulding. Pillat states in his work that he had seen an ancient drinking vessel of a Medrecan form, on a foot of considerable substance, nearly entire, and procured from Rome, which had the appearance of having been blown in an open-and-shut mould, the rim being afterwards cut off and polished. This is high authority, and, with other evidences that might be cited, goes far to prove that the ancients used moulds for pressing, and also for blowing moulded articles, similar to those now in use. Pompeian window-glass, of which panes have been discovered as large as twenty by twenty-eight inches, has proved, on examination, to have been cast in a manner similar to that now followed in making plate-glass, except that it was not rolled flat, as now, by metal cylinders, but pressed out with a wooden mallet, so that its thickness is not uniform. A glass has been discovered at Pompeii, about the size of a crown piece, with a convexity, which leads one to suppose it to be a magnifying lens. Now, it has been said that the ancients were not aware of this power, and the invention is given to Galileo by some, to a Dutchman, in 1621, by others, while a compound microscope is attributed to one Fontana, in the seventeenth century. But without a magnifying glass, how did the Greeks and Romans work those fine gems which the human eye is unable to read without the assistance of a glass? There is one in the Naples Royal Collection, for example, the legend of which it is impossible to make out, unless by applying a magnifying power. The glass in question, with a stone ready cut and polished for engraving, are now to be seen in the Museum of Naples. Specimens of colored glass, pressed in beautiful forms for brooches, rings, beads, and similar ornaments, are numerous. Of those of Roman production many specimens have been found in England. Some of these were taken from the Roman barrows. In Wales glass rings have been found; they were vulgarly called "snake stones," from the popular notion that they were produced by snakes, but were in fact rings used by the Druids as a charm with which to impose upon the superstitious. We find, too, that the specific gravity of the specimens referred to ranges from 2034 to 3400, proving oxide of lead to have been used in their manufacture; the mean gravity of modern flint-glass being 3200. From what we gather from the foregoing facts, we are inclined to the belief that, in fine fancy work, in colors, and in the imitation of gems, the ancient glass-makers excelled the modern ones. They were also acquainted with the art of making and using moulds for blown and pressed glass, and forming what in England is now called patent pillar glass. All these operations, however, were evidently on a very limited scale, their views being mainly directed to the production of small but costly articles. Although in the time of the Roman manufacturers vases of extra size were made, requiring larger crucibles and furnaces than those used by the glass-makers of Tyre, yet it is evident that they produced few articles except such as were held sacred for sepulchral purposes, or designed for luxury. And while they possessed the knowledge of the use of moulds to press and blow glass by expansion, it does not appear that they produced any articles for domestic use. If it were not thus, some evidences would be found among the various specimens which have been preserved. LEGENDS OF THE GLASS-HOUSE, ETC. Enough has been adduced to show the peculiar estimation in which the art of glass-making was formerly held, and the privileges conferred on it by the various governments of Europe. The art was thus almost invested with an air of romance; and a manufacture commanding so much attention on the part of the governments was regarded with a great share of awe and wonder. It is not strange that, in this state of things, various legends should have been identified with the manufacture and its localities. Among these legends was that which ascribed to the furnace-fire the property of creating the monster called the Salamander. It was believed, too, that at certain times this wonderful being issued from his abode, and, as opportunity offered, carried back some victim to his fiery bed. The absence of workmen, who sometimes departed secretly for foreign lands, was always accounted for by the hypothesis that in some unguarded moment they had fallen a prey to the Salamander. Visitors, too, whose courage could sustain them, were directed to look through the bye-hole to the interior of the furnace, and no one failed to discover the monster coiled in his glowing bed, and glaring with fiery eyes upon the intruder, much to his discomfiture, and effectually as to his retreat. Some gallant knights, armed _cap-a-pie_, it is said, dared a combat with the fiery dragon, but always returned defeated; the important fact being doubtless then unknown or overlooked, that steel armor, being a rapid conductor of heat, would be likely to tempt a more ready approach of the fabled monster. There was another current notion, that glass was as easily rendered malleable as brittle, but that the workmen concealed the art, and the life of any one attempting the discovery was surely forfeited. An ancient writer on glass, "Isidorus," states that, in the reign of Tiberius, an artist, banished from Rome on political considerations, in his retirement discovered the art of rendering glass malleable; he ventured to return to Rome, in hopes of procuring a remission of his sentence, and a reward for his invention; the glass-makers, supposing their interest to be at stake, employed so powerful an influence with the Emperor (who was made to believe that the value of gold might be diminished by the discovery), that he caused the artist to be beheaded, and his secret died with him. "Blancourt" relates that, as late as the time of Louis XIII., an inventor having presented to Cardinal Richelieu a specimen of malleable glass of his own manufacture, he was rewarded by a sentence of perpetual imprisonment, lest the "vested interest" of French glass manufacturers might be injured by the discovery. Even at the present day the error is a popular one, that if the art of making glass malleable were made known, it would have the effect of closing nearly all the existing glass-works; while the truth is, that quite the reverse would be the result. Whenever the art of making glass malleable is made known, it will assuredly multiply the manufacture to a tenfold degree. It was formerly the custom for the workmen, in setting pots in the glass-furnace, to protect themselves from the heat by dressing in the skins of wild animals from head to foot; to this "outre" garb were added glass goggle-eyes, and thus the most hideous-looking monsters were readily presented to the eye. Show was then made of themselves in the neighborhood, to the infinite alarm of children, old women, and others. This always occurred, with other mysterious doings, on the occasion of setting the pot, or any other important movement attendant on the business. The ground was thus furnished for very much of the horrible _diablerie_ connected with the whole history of the manufacture. A belief was long prevalent that glass drinking vessels, made under certain astronomical influences, would certainly fly to pieces if any poisonous liquid was placed in them; and sales of vessels of this kind were made at enormous prices. Another idea pervaded the community, that vessels of a certain form, made in a peculiar state of the atmosphere, and after midnight, would allow a pure diamond to pass directly through the bottom of the vessel. Various articles, such as colored goblets, were thought to add to the flavor of wine, and to detract materially from its intoxicating quality. All these, and many other popular notions, added greatly to the mystery and renown of glass manufacturers. We close this number with an extract from "Howell's Familiar Letters." "Murano," says he, "a little island about one mile from Venice, is the place where crystal glass is made, and it is a rare sight to see whole streets where on one side there are twenty furnaces at work. They say here, that although one should transfer a furnace from Murano to Venice, or to any of the little assembled islands about here, or to any other part of the earth beside, to use the same materials, the same workmen, the same fuel, and the selfsame ingredients every way, yet they cannot make crystal glass in that perfection for beauty and lustre as at Murano. Some impute it to the circumambient air, which is purified and attenuated by the concurrence of so many fires, that are in these furnaces night and day perpetually, for they are like the vestal fires, never going out." There is no manufacturing business carried on by man combining so many inherent contingencies, as that of the working of flint glass. There is none demanding more untiring vigilance on the part of the daily superintendent, or requiring so much ability and interest in the work. Unlike all other branches of labor, it is carried on by night and day, is governed by no motive power connected with steam or water, and has no analogy to the production of labor by looms or machinery. The crude material of earth being used, each portion requires careful refining from natural impurities, and when compounded, being dependent upon combustion in the furnace for its completion, (which combustion is effected by change of the atmosphere beyond the power of man to direct, but exercises a power to affect the heat of the furnace acting for good or for evil,) much responsibility rests upon the furnace-tenders; constant care on their part is required. A slight neglect affects the quality of the glass. A check upon the furnace in founding-time will spoil every pot of metal for the best work. Overheat, too, will destroy the pots, and the entire weekly melt will be launched into the cave, at a loss of several thousand dollars. Even with the utmost care, a rush of air will not uncommonly pass through the furnace and destroy one or more pots in a minute's space. And when the furnace has yielded a full melt, and is ready for work, many evils are at hand, and among the ever-jarring materials of a glass-house, some one becomes adverse to a full week's work; vigilance is not always the price of success. Again: no branch of mechanical labor possesses more of attraction for the eye of the stranger or the curious, than is to be witnessed in a glass-house in full play. The crowded and bee-like movements of the workmen, with irons and hot metal, yet each, like the spheres of his own orbit, presents a scene apparently of inextricable confusion. It is a difficult task to describe the curious and interesting operations of the glass-blowers; for the present we may say, that there is no other employment so largely dependent upon steadiness of nerve and calm self-possession. The power of manipulation is the result of long experience. The business of the glass-blower is literally at his "fingers' ends." It is most interesting to witness the progress of his labor, from the first gathering of the liquid metal from the pot, and the passing it from hand to hand, until the shapeless and apparently uncontrollable mass is converted into some elegant article. Equally interesting is it to witness with what dexterity he commands, and with what entire ease he controls the melted mass; the care, also, with which he swings it with force just enough to give it the desired length, joins it to other pieces, or with shears cuts it with the same ease as paper. The whole process, indeed, is one filled with the most fascinating interest and power. Of all the articles of glass manufacture, none command a greater degree of attention than the article called the salver, and no other develops so pleasing and surprising effects in its processes. When seen for the first time, the change from a shapeless mass, the force with which it flies open at the end of the process, changing in an instant into a perfect article, all combine to astonish and delight the beholder. Mystery is as much a characteristic of the art now as at any former period; but it is a mystery unallied to superstition,--a mystery whose interpreter is science,--a mystery which, instead of repelling the curious and frightening the ignorant, now invites the inquiring and delights the unlearned. By the following, we find that the romance of glass-making has not yet died out. We copy from the "Paris Annual of Scientific Discovery," for 1863, the following:-- "It would appear there is yet some secret in glass-making unknown to the world at large, as the manufactory of Mr. Daguet, of Soletere, France, is known to be in possession of an undivulged method, which enables them to make glass of a purity which all other manufacturers are not able to rival. A railway, recently constructed and running past Mr. Daguet's works, has so affected the glass-pots, by the tremor occasioned by the locomotives and trains, that work has had to be suspended. For this Mr. Daguet brought an action, during the past year, against the railway company for damages; but when the case came on for trial, the court held that it would be impossible to assess damages unless it were made cognizant of the secret, and its pecuniary advantage to Mr. Daguet. The latter declined imparting this, and the court refused to proceed further." We have shown that glass, while it has contributed so largely to the material well-being of man, has also administered profusely to the pleasure of woman. The belle enjoys the reflection of her beauty in its silvered face,--a pleasure peculiarly her own, as we all know,--and if we may believe poesy, the mermaid, her rival of the coral groves in the fathomless ocean, looks with equal satisfaction upon her dubious form, as seen in her hand-mirror. And what would Cinderella be to the nursery without her glass slipper! But leaving poetry to its own prolific devices, where would science find itself without the aid of glass? The astronomer's and chemist's vocation would be gone. Suns, planets, and stars would have no exact existence to us, and their laws be unknown. The seaman would blunder his way on the ocean, lucky if he guessed aright his course, and cursing his "stars," when he did not. In short, glass is the indispensable servant of science in almost all its forms, and where it does not discover it protects. Its loss would throw back the world into antediluvian ignorance, not to mention the countless eyes it would deprive of sight, of their intellectual food, and freedom of way. MANUFACTURE OF GLASS IN THE UNITED STATES, ETC. The last number of our series of articles upon this highly interesting subject--interesting both as concerns the various features of the manufacture, and as indicative of the progress of the art in the successive ages of the world's history--closed the sketch of the rise and progress of the manufacture of flint glass. Our sketch has covered the ground so far as time would allow, from the introduction of the art into Egypt, through its transfer to Tyre and Sidon, and from thence, in its order, to Rome, Venice, France, and finally into England. The reader will notice that this progress, like that of many others, is almost identical, for a time at least, with the gradual extension of conquest, and especially with this, as connected with the extension of the Roman sway. We now reach the period of its introduction into the Western continent, and propose giving an outline of its gradual extension and characteristics in our own land. Our opportunity of research as to the period of the introduction of glass manufacture into this country, induce the belief that the first effort was made some years before the American Revolution. This attempt was by a company of Germans, who selected the town of Quincy, in this State, as the place in which to establish the manufacture. We are acquainted with little beyond the fact, that such an attempt was made; their success, or the length of time during which they carried on the work, are matters equally beyond our knowledge. Some specimens of their articles still exist, showing mainly that they engaged in the manufacture of what is called black metal only; these also are of the rudest style of the art. The place in Quincy in which their manufactory was established acquired the name from them of "Germantown," which name it retains to the present time. The site of their manufactory is now occupied, we believe, by the institution called "The Sailors' Snug Harbor." A Connecticut paper states a patent was granted by that State, in 1747, for twenty years, to Thomas Darling, for the exclusive privilege of making glass. This Act appears to have become void, because of the patentee not fulfilling its conditions, and at various times after this special grants were made to others to introduce the manufacture of glass. The Historical Society of Brooklyn, N.Y., has in their cabinet "a glass bottle, the first one manufactured at a glass-works started, in 1754, near the site of the present glass-works in State Street. This enterprise, we are informed, was brought to an untimely end for want of sand,--that is, the right kind of sand." From this we infer, it must be a flint-glass bottle, as the sand suitable for green or black glass abounds on their shore. Shortly after the close of the Revolutionary struggle, we think about the year 1785, the late Robert Hewes, a well-known citizen of Boston, made, probably, the first attempt to establish a window-glass manufactory on this continent. This manufactory was modelled upon the German system. Mr. Hewes carried his works to the fuel, and erected his factory in the then forest of New Hampshire. The writer well remembers, when a boy, hearing Mr. Hewes relate, that when building his glass-works the tracks of bears were frequently seen in the morning in and around his works. From the best information in our possession, we think that to Mr. Robert Hewes must be conceded the first attempt to establish window-glass making in the United States, or in the western world. The aim of Mr. Hewes was doubtless to supply the most important and necessary article made of glass, and called for by the immediate wants of the people, viz., window-glass. It ended, however, in disappointment to the projector, probably from the frequent error of carrying such works into the interior, to the vicinity of fuel, or from lack of skill on the part of the workmen. This attempt was followed, about the year 1787, by Messrs. Whalley, Hunnewell, and their associates, and by the workmen Plumback and Cooper, who erected a large factory in Essex Street, Boston (where Edinboro' Street now is), for the purpose of making the Crown Window Glass. This was without success, until a German, of the name of Lint, arrived in the year 1803, and from this period there was great success in the manufacture, for the State of Massachusetts, to encourage the manufacture of window-glass, paid the proprietors a bounty on every table of glass made by them. This was done to counteract the effect of the bounty paid by England on the exportation of glass from that kingdom. The State bounty had the effect to encourage the proprietors and sustain their efforts, so that by perseverance many difficulties were overcome, and a well-earned reputation supported for the strength and clearness of their glass; a glass superior to the imported, and well known throughout the United States as "Boston Window-Glass." This reputation they steadily sustained, until they made glass in their new works at South Boston, in the year 1822. Their charter from the State was highly favorable to the stockholders; among the privileges it granted an exclusive right to manufacture for fifteen years, and to manufacture glass without their consent subjected the offender to a fine of five hundred dollars for each offence. Their capital was exempt from taxation for five years, and the workmen exempted from military duty. From the founding of this establishment may be dated the founding of all the Crown and Cylinder, Window and Flint Glass-Works in the Atlantic States. Indeed, this may be considered the fruitful parent tree of the many branches now so widely spread abroad. The wonderful mystery attached to the art of glass-making seems to have followed its introduction into this country. The glass-blower was considered a magician, and myriads visited the newly-erected works, and coming away with a somewhat improved idea of an unmentionable place and its occupants; and the man who could compound the materials to make glass was looked upon as an alchemist who could transmute base metal into pure gold. The fame of the works spread into a neighboring State, and in 1810 or 1811 a company was formed in Utica, to establish glass-works in that place, and quite a number of workmen in the Essex Street Works were induced to leave their employ and break their indentures from the offer of increased wages; while, however, on their way, and just before they reached the State line, they, with the agent, were arrested, brought back, and expensive lawsuits incurred. The Utica Works were abandoned, and, we believe, never revived. Subsequently another company was formed in New York, being influenced by a fallacious view of the silicious sand. This company erected their works at Sandy Lake, a locality abounding both in silex and fuel. A few years' trial convinced the proprietors the place was ill chosen, and, after the experience of heavy losses, it was abandoned. A Doctor Adams, of Richmond, Virginia, made large offers of increased wages to the workmen of the Essex Street Works, who were then induced to abandon their place of work and violate their indentures. They succeeded in reaching Richmond to try their fortune under the auspices of the Doctor. A few years' experience convinced them of the fallacy of increased pay; for, after very heavy losses, the works were abandoned and the workmen thrown out of employ. The proprietors of the Essex Street Works had engaged workmen in the mean time, at a very heavy expense, from England--a most difficult task, for the English government made it a penal offence to entice workmen to leave the kingdom at that period. In 1811 the proprietors of the Essex Street Works erected large and improved works on the shore at South Boston. To supply the workmen enticed away, and also to meet the wants of their factory, an agent was sent to England to procure a set of glass-workers. By the time they reached this country the war with England broke out, and the enterprise was thus defeated; for it became difficult to procure fuel and the various means for carrying on the Essex Street Works. The making of window-glass in Boston led to the introduction of the manufacture of flint-glass, arising from the excess of window-glass blowers, brought into the country by the enterprise of the Boston Window-Glass Company; many among the number from Europe had worked more or less in flint-glass works (no unusual thing in England), for a good flint-glass blower, with manual strength, can fill the part of a window-glass blower, and exceedingly well. Among the number was a Mr. Thomas Caines, now living at South Boston, having retired from the business with an independent property, the honest fruit of his skill and industry; he may be truly considered as the father of the flint-glass business in the Atlantic States. Mr. Caines proved competent to the task, not only as a first-rate workman, but possessed the art of mixing the materials and being able to sustain all the other departments appertaining to the business. He prevailed upon the proprietors to erect a small six-pot flint furnace in part of their large unoccupied manufactory in South Boston. At that time the articles of flint-glass imported by the earthenware trade were confined to a very few articles, such as German straw tumblers, cruets, salts, and plain decanters of cheap fabric; of the finer articles, to cut finger tumblers, sham diamond cut dishes, and Rodney decanters; a quality of glass and cutting that would not at the present day command one-fifth of their then cost. War having interrupted the importation of glass, the manufactory supplied the then limited demand, and gave full employ for their factory. Contemporaneous with the South Boston enterprise, a company was formed and incorporated under the title of the Porcelain and Glass Manufacturing Company. Their factory was located at East Cambridge, then called Craigie's Point. Their china department was directed by a Mr. Bruitan, but for want of proper materials it proved an entire failure. Their glass-works were under the direction of a Mr. Thompson, who built a small six-pot furnace, similar in size to the one at South Boston. Thompson brought out a set of hands, at a heavy expense, to work the furnace, but the result proved he was in no way qualified for the task, nor possessed of the least practical skill or knowledge of the business, and of course proving an entire failure. The attempt to make porcelain and glass was abandoned by the company. In 1815, some of the workmen left the South Boston Factory and hired of the Porcelain Company their six-pot furnace, and commenced the making of flint-glass under the firm of Emmet, Fisher & Flowers. They succeeded for a time very well, and turned out glass suitable for the trade; but want of concert of action prevented a successful result, and they dissolved without loss. The Porcelain Company, discouraged by so many failures, agreed to wind up their concern, and in November, 1817, they disposed of their entire property at public auction. As one manufactory dies out only to give place to another, so the present New England Glass Company was formed, and became the purchasers of the Porcelain Works. That company, from 1817, to the present time, have pursued the business with signal success; beginning with the small capital of forty thousand dollars, they have from time to time increased it, until it amounts at the present time to half a million of dollars. They commenced business with a small six-pot furnace, holding seven hundred pounds to each pot; employed, all told, about forty hands, and the yearly product did not exceed forty thousand dollars. They now run five furnaces, averaging ten pots to each, capacity of two thousand pounds to each pot. They employ over five hundred men and boys, and the yearly product is not less than five hundred thousand dollars. In 1820 some of their workmen left them, built a factory in New York City, and conducted their business under the firm of Fisher & Gillerland. In 1823 Gillerland dissolved the connection and built, on his own account, a manufactory in Brooklyn, N.Y., which he conducts at this period with great skill and success, and is considered the best metal mixer in the United States. In 1825 a Flint-Glass Manufactory was established by individual enterprise in Sandwich, Mass. Ground was broke in April, dwellings for the workmen built, and manufactory completed; and on the 4th day of July, 1825, they commenced blowing glass--three months from first breaking ground. In the following year it was purchased of the proprietor, a company formed, and incorporated under the title of Boston and Sandwich Glass Company. Like their predecessors, they commenced in a small way; beginning with an eight-pot furnace, each holding eight hundred pounds. The weekly melts at that period did not exceed seven thousand pounds, and yearly product seventy-five thousand dollars; giving employment to from sixty to seventy hands. From time to time, as their business warranted, they increased their capital until it reached the present sum of four hundred thousand dollars. Their weekly melts have increased from seven thousand pounds to much over one hundred thousand pounds; their hands employed from seventy to over five hundred; their one furnace of eight pots to four furnaces of ten pots; and yearly product from seventy-five thousand dollars to six hundred thousand dollars. In 1820 another secession of workmen from the New England Glass Company took place, to embark on their own account their savings of many years in the doubtful enterprise of establishing flint-glass works in Kensington, Philadelphia, under the title of the Union Flint-Glass Company. The proprietors, being all workmen, were enthusiastic in the project, happy in the belief that they could carry it on successfully, work when convenient, and enjoy much leisure. All was _then_ to them sunshine. Ere long they realized the many inherent evils attendant on flint-glass works; the demon of discord appeared among them, and they discovered, when too late, that they had left a place of comfort and ease for a doubtful enterprise. Death thinned their ranks, and the works, after passing into other hands for a short trial, have years since ceased to exist. From 1820 to 1840 very many attempts were made, by corporations and firms, to establish the manufacture of flint-glass in the Atlantic States, but almost with entire failure. The parent tree, the old South Boston concern, failed; the works were revived from time to time by at least five different concerns, and all ended in failure; and for years the works remained closed, till the present occupant, Mr. Patrick Slane, hired the premises, and by his enterprise and great industry has greatly enlarged the works, and is now carrying on a large and active business. In his factory we learn the old system among the operatives he does not allow to have a foothold, and the individual industry of his hands is not cramped or limited by the oppressive system of the old school operative. As a record of the past and a reference for the future, we find, in reviewing the various attempts to establish flint-glass works in the Atlantic States, that it would not be just to place the names of those identified with them before the reader; for many were deluded by the projectors with promises of the most flattering success, but realized only disappointment and loss. In enumerating all the concerns, companies, and corporations that have been engaged in the manufacture of flint-glass in the Atlantic States, we find the number to be forty-two; of which number two concerns have retired, and ten are now in operation, viz., two at East Cambridge, three at South Boston, one at Sandwich, three near New York City, and one at Philadelphia; leaving two concerns who retired with property, and twenty-eight out of the forty-two concerns entire failures, involving the parties interested in heavy loss, the fate of the existing ten to be determined by future events. Before closing, we may allude to the repeated failure of permanently establishing window- and bottle-glass works in this vicinity. The primary cause has been in the construction of the furnaces, no improvement for centuries having taken place, but the old defective plan being adhered to by workmen from Europe. A casual observer must see they are defective, and consume double the quantity of fuel really required for the weekly melts. The rate of wages for experienced workmen, about threefold over the German rates, has heretofore checked success, but at the present time is more than compensated by machinery and materials. The manufacture of plate-glass offers a profitable and inviting field that should be improved. The consumption in this country is large and increasing yearly. Materials are cheaper than in Europe, and as the most essential part is performed by machinery and motive power, this will more than equalize the extra rate of wages that may be taxed upon a new undertaking. We have recorded the rise and progress of the Glass Manufacture in the Atlantic States, showing its course from its introduction in 1812 to the present period, _i.e._ 1852, covering a space of time of just forty years. We now turn to the introduction of the manufacture in the Western States, for the account of which we are indebted to Mr. Thomas Bakewell, of Pittsburg, Penn. Mr. Bakewell advises us, that, prior to the year 1808, glass-works were established by a company of Germans, near Fredericktown, Maryland, under the direct control of a Mr. Amelong, for the purpose of manufacturing glass in all its branches. We have not ascertained the precise year in which Mr. Amelong commenced the manufacture; but previous to the year 1808 the establishment was broken up, and the workmen dispersed. Most of them reached Pittsburg, Penn., and a part of them were engaged by Col. James O'Hara, in the establishment of the first window-glass factory in the Western States. The same factory is in operation to the present day, and others of the Fredericktown company were instrumental in introducing the same branch of the glass business into Pennsylvania, at New Geneva, upon the property of the late Albert Gallatin. Others of the number, previously mentioned, established themselves in Baltimore, and in all of the places noticed. Some of their descendants still continue the business. There are at this time ten window-glass factories in the vicinity of Pittsburg, and fifteen in the river towns,--in all twenty-five works,--manufacturing over 220,000 boxes of window-glass of 100 feet each annually. We now proceed to examine a more interesting topic, viz., the rise and progress of the flint-glass business in the West. We have shown that most of the workmen, on the breaking up of the glass-works in Fredericktown, migrated to Pittsburg, attracted there, doubtless, by the coal mines. Some of these persons were successful in establishing the manufacture of window-glass, while a portion of the workmen, in the spring of the year 1808, attempted to establish a flint-glass manufactory upon part of the premises now occupied by Bakewell & Pears, extensive flint-glass manufacturers. The persons engaged in the enterprise, however, were deficient, both in the requisite knowledge and capital; the effort proved abortive, the parties quarrelled, and the establishment, in an incomplete condition, was offered for sale. In the August following, a Mr. Bakewell and his friend, Mr. Page, being on a visit to Pittsburg, were induced to purchase the concern, under the representation of one of the owners that he possessed the information and skill requisite for the proper pursuit of the business, having been engaged (as he stated) in the business before he left England. Mr. Bakewell had scarcely entered upon his new pursuit before he discovered that the qualification of the person alluded to had been entirely misrepresented, and that to succeed he must rely upon his own experience and diligence in the attainment of the peculiar knowledge indispensable to the success of his undertaking. In this the fortune of his family and friend were, of course, deeply involved, and he therefore set himself to the accomplishment of his task most manfully. Those only who have practical experience of the character of the undertaking can fully appreciate the various and almost insurmountable difficulties to be encountered and overcome before success could be attained. His first difficulty arose from want of skill in the workmen, and the inferiority of the materials employed in the manufacture of flint-glass. So little were the resources of the West developed at that day, that Mr. Bakewell had to procure his pearlash and red lead from Philadelphia, the pot clay from Burlington, N.J.,--the whole being transported over the mountains in wagons to Pittsburg. The only sand then known was the yellow kind, obtained in the vicinity, and used at this time only for window-glass. For many years Mr. Bakewell obtained the saltpetre needed from the caves of Kentucky, in a crude state, which article he was obliged to purify, until the period of 1815, when the required supply was obtained from Calcutta. The few workmen then in the country were not well instructed in the making of glass articles, after the glass was prepared, to which was added the great evil (which has too usually prevailed among the imported workmen) of a determination to prevent the instruction of apprentices by the most arbitrary and unjust means, and, so far as it was in their power, endeavoring to prevent competition, by not only controlling the hours of work, but the quantity of manufacture; in fact, doing the least amount of work possible for the largest amount of pay that could be coerced from the proprietors. Experience, however, showed Mr. Bakewell how to construct his furnaces, or, at least, to improve on the old; and he discovered better materials in his immediate vicinity, and succeeded in making purer glass than he had before made. The oppressive acts of the workmen, in the mean time, compelled Mr. Bakewell to resort to England for new workmen, at a time when the prohibitory laws there in regard to mechanics leaving England were in full force,--an undertaking requiring great secrecy, and at the risk of long imprisonment if detected. Such were some of the embarrassing circumstances with which Mr. Bakewell had to contend. Of the full force and extent of these, those only can conceive who have been under like necessities and circumstances. But a brighter day was dawning upon his exertions, and at length his arduous and untiring labor was crowned with the desired success. Good clay was procured from Holland, and purer materials discovered; competent workmen were either imported or instructed, and the flint-glass manufacture was firmly established at Pittsburg. From this first establishment there originated, in a few years, many other glass-works, erected chiefly by persons who had acquired the art with Mr. Bakewell, or had obtained the requisite means while in his employ. We may well consider Mr. Bakewell as the father of the flint-glass business in this country; for he commenced the work in 1808, and by untiring efforts and industry brought it to a successful issue. For the skill, judgment, labor, and perseverance devoted by him to the progress of the art, he truly merits the "Artium Magister" so often bestowed on those least worthy of its dignity and honor. Theory in Science too often receives the meed which practical progress in its walks so richly deserves. Mr. Bakewell lived to realize an ample fortune as the fruit of his industry, and his sons still carry on a profitable business on the premises originally occupied by their father. By father and sons this has covered a space of forty-four years, a length of time rarely finding a business in the same family in America. May the factory be always occupied and conducted by a Bakewell. The furnace built by Mr. Bakewell in 1808 contained only six pots, twenty inches in diameter, which were replaced in 1810 by a ten-pot furnace of a larger capacity, and in 1814 another furnace was added to the works, of like capacity. In 1809 another concern sprung up, and carried on the business on a limited scale; in 1812 another succeeded, making three concerns carrying on the business; and in 1810 another company was formed, but failed in a few years. There are now in Pittsburg nine concerns manufacturing flint-glass, running thirteen furnaces and one hundred and five pots. There are also three concerns at Wheeling, running five furnaces and forty-five pots. There are also at Wellsville, Steubenville, and Cincinnati one or two factories each, besides several manufactories for green glass jars, and one for the making of porter bottles; one also for mineral-water bottles. The first glass-cutting works were opened in 1809 by a German of the name of Echbaum, who had settled in Pittsburg some years previously. Mr. Bakewell also carried on glass-cutting, and among his workmen was an Englishman who had served as a soldier in Canada, being taken as a prisoner in one of the battles on the Lakes in 1813. He proved not only a good glass-cutter, but an excellent mechanic, in various branches; but still a dissipated and idle man, and of course of but little service in the manufactory. One of the amusing incidents connected with the manufacture occurred when General Clark (then Governor of Missouri) took a party of Osage Chiefs to Washington. On their way they visited Bakewell's Glass-Works, and their attention was greatly excited; they watched with great curiosity the process of making various articles, and the mode of affixing the handle to a glass pitcher quite disturbed the equanimity of the head chief, who, after shaking hands with the workmen, said, through the interpreter, "That man must have had some intercourse with the Great Spirit." The following, from Sigma's pen, shows a decanter-stopper can be made to point a moral or illustrate a satire:--"Mr. Flint, in his 'Ten Years in the Valley of the Mississippi,' tells a pleasant story of an Indian who told him he had _big diamond_, for which he had given trader _much beaver_. A time was appointed, and Mr. Flint visited the wigwam to examine the diamond, which, after considerable mystery, was brought forth from its place of concealment, and proved to be a broken glass decanter-stopper. When an individual, eminent for his talents and learning, has been justly decorated with the degree of LL.D., and finds the same mark of distinction bestowed upon others who are remarkable for neither, he cannot fail to perceive an amusing resemblance between his diploma and Kunkerpot's diamond." IMITATION OF MUSLIN-GLASS. Here is a simple and ingenious means of giving to glass the appearance of delicately wrought muslin:-- The process, which comes to us from Germany, consists in spreading very smoothly a piece of lace or tulle, and covering it with some fatty substance by means of a printer's roller. The glass being carefully cleaned, the cloth is laid upon it so as to leave in fat a print on the surface of all the threads of the fabric. The glass is then exposed about five minutes to the vapors of hydrofluoric acid, which roughens the spaces between the lines, and leaves the polish on the surface under the fat. A glass thus prepared becomes like a veil, protecting from exterior indiscretion persons who, from their apartment, desire to look commodiously outside. We recall here that the manipulation of hydrofluoric acid requires great prudence. This acid is so corrosive that a drop of its vapor condensed produces upon the hand a lively inflammation, and may even lead to graver accidents. Breathing the emanations should therefore be avoided with the greatest care. No art has been characterized, in the course of its progress, by so much of wonder and undefined belief in the supernatural, as that of the manufacture of glass in its various modes and articles. The old glass-works in Wellsburg, Va., were pulled down a few years since with a tremendous crash. They were erected in 1816, and, with the exception of the establishments at Pittsburg, were the oldest west of the mountains. The beginning of their career was prosperous, but the last owners have invariably sunk money in carrying on the works, and to prevent further losses they have now been finally destroyed, and the ground turned into a potato-patch. [From the "Scientific American."] ETCHING AND ORNAMENTING GLASS. The hardest glass may be etched and frosted with a peculiar liquid acid, and also with this acid in the condition of vapor. When powdered fluor spar is heated with concentrated sulphuric acid in a platinum or a lead retort, and connected with a refrigerator by a tube of lead, a very volatile, colorless liquid is obtained, which emits copious white and suffocating fumes. This is hydrofluoric acid, a dilute solution of which attacks glass with avidity, while neither sulphuric, nitric, nor muriatic acid has the least effect upon it. In a diluted state it is employed for glass etching, for which purpose it is kept in a lead vessel, because it has very little affinity for this metal. The vapor of this acid is also used for the same purpose. The glass to be operated upon is first coated with a ground of wax, and the design to be etched is then traced through the wax with a sharp instrument. In a shallow lead basin some powdered fluor spar is then placed, and a sufficient quantity of sulphuric acid poured upon it to convert it into a thin paste. The glass to be etched is now placed in the basin, to which a gentle heat is applied, when the vapor of the acid is disengaged and attacks the traced lines from which the wax has been removed. The operation is completed in a few minutes, the glass is removed, and the wax cleaned off with warm oil of turpentine. All those parts which have remained covered with the wax are now clear as before, while the other parts drawn by lines to represent figures have a frosted appearance. Any person can produce figures on glass with this acid, but, for reasons before stated, it is dangerous to use. In October, 1859, a patent was granted to James Napier, of Glasgow, Scotland, for a very simple method of ornamenting glass with fluoric acid. Instead of drawing patterns and figures on the glass with the use of varnish and a graver to prepare the glass for etching, the glass is prepared by simply transferring pictures from prints, which can be performed by almost any person. The method is, to take a print, lithograph, or picture made with printer's ink, and fix the printed surface to the glass by any ordinary paste made from starch. All the air must be carefully excluded from between the print and glass. When perfectly dry, liquid hydrofluoric acid about the specific gravity of 1.14 is applied for about three minutes, when it is washed in water to remove the paper and the acid, and the figure of the print is then found upon the glass. The printed portion of the paper may also be cut in outline and pasted on the glass, then transferred. Glass that is "flashed" on the surface with another color may be treated in this manner, when a portion of the flashing or surface will be removed, and the picture will remain in color. COLORED GLASS. The distinguished French chemist, M. Chevreul, who has devoted so much attention to the subject of color, has lately published a memoir on painted windows, in which there are many points which deserve the attention of artists and others who are interested in the manufacture of colored glass. It has often been much noticed that old stained glass windows have a much richer effect than modern ones, and M. Chevreul, speaking of this superiority, attributes it to what moderns regard as defects. In the first place, much of the ancient glass is of unequal thickness, and so presents convex and concave parts, which refract the light differently and produce an agreeable effect. In the next place the old colored glass is not a colorless glass, to which has been added the particular coloring material, such as protoxide of cobalt, &c. Old glass contains a good deal of oxide of iron, which colors it green, and to this must be attributed the peculiar effects of antique glass, colored by cobalt and manganese. M. Chevreul appears to think that modern stained glass is too transparent to produce the best effects. M. Regnault, the chemist, has recommended that all this kind of stained glass should be cast, to avoid the monotonous effect of plain surfaces on the light; and also that foreign substances should be mixed with the glass to diminish its transparency. Many attempts have been made to color with ruby or other colors gas shades, so as to throw on surrounding objects the color of the glass; but in no case has the ray of light passing through colored glass, to refract the shade, been successful. But when a ray of solar light is passed through a colorless prism, it is refracted, and forms, when thrown on a wall or screen, a broad band of colored light,--red, orange, yellow, green, blue, indigo, and violet,--which is known as the prismatic or solar spectrum. ARTIFICIAL DIAMONDS. We find a report in French journals that M. Gannal has succeeded in obtaining _crystals_, having all the property of the diamond, through the mutual reaction of phosphorus water and bisulphide of carbon upon each other for the space of fifteen weeks. The crystals were found to be so hard that no file would act upon them. They cut glass like ordinary diamonds, and scratched the hardest steel. In brilliancy and transparency they were in no way inferior to the best jewels, and some possessed a lustre surpassing that of most real stones. For reference we record the cost of materials for flint-glass, say in 1840 to 1845, as follows:-- Litherage, or red lead, cost 6-1/2 cts. per lb. Pearlash, 6 " " Nitre, 6 " " Silex, 0-1/2 " " Present price, 1864:-- Red lead, 21 cts. per lb. Pearlash, 17 " " Nitre, 6 " " Silex, 0-3/4 " " We now refer to the early introduction of the manufacture of glass into England. The English manufacturers, like ourselves, had to struggle with the various evils incident to the introduction of a new art. France and Germany, from their long experience in the making of glass, were enabled for a long time to undersell the English manufacturer in his own market. To foster and protect this branch of national industry, the English government imposed a heavy tax on all foreign glass imported into their dominions. This measure secured to the English manufacturer the entire trade, both with their colonies and with the home market, thus giving such substantial encouragement to the enterprise, that, in a few years, the manufacture was so much increased as to admit of exportation. To stimulate the exportation of various articles of English production, the government, in the latter part of the eighteenth century, granted bounties, from time to time, on linens, printed cottons, glass, &c, &c. Until the bounty on glass was allowed, the exportation of glass from England to foreign countries was very limited; for the French and Germans, as has before been stated, for various reasons could undersell the English; but the government bounty changed the aspect of affairs, and shortly the English manufacturers not only competed with the Germans and French for the foreign market, but actually excluded them from any participation,--the government bounty being equal to one half the actual cost of the glass exported. An Act of Parliament levied on flint-glass an excise duty of ninety-eight shillings sterling on all glass made in England, which excise was paid by the manufacturer, being about twenty-five cents per pound weight, without regard to quality; but if such glass was exported, the excise officer repaid the tax which it was presumed the manufacturers had paid, and a clear bounty of twenty-one shillings sterling was paid by the government to the exporter on each hundred weight of flint-glass shipped from England, being equal to five cents per pound. Under such encouragement the export increased from year to year to a very great extent, so that the excise duty of ninety-eight shillings sterling on the amount consumed at home did not equal the amount paid out in bounty. In the year 1812, fifty-second George III., an Act was passed reducing the excise duty to forty-nine shillings, and the export bounty to ten shillings sixpence. In 1815 the Act was renewed, and again in 1816. In 1825, sixth George IV. chap. 117, an Act was passed revising the former as to the mode of levying the excise duty and bounty, so as to prevent frauds on the revenue, which had hitherto been practised to a very great extent. This act remained in force until the Premiership of Sir Robert Peel, when both excise and bounty were abrogated, and the English manufacture stands on the same footing in foreign countries as those of other nations. By the protecting hand of the English government the flint-glass manufactories multiplied with very great rapidity, underselling all other nations, and not only rivalling, but far excelling them in the beauty, brilliancy, and density of the articles manufactured. The greatest stimulus ever given to the glass manufacture of England was the abolition of the duty on it in 1845. That abolition has produced a somewhat paradoxical result. While the quantity of glass made has increased in the proportion of three to one, the number of manufacturing firms has diminished in the proportion of one to two. In 1844 there were fourteen companies engaged in the manufacture. In 1846 and 1847, following the repeal of the duty, the number had increased to twenty-four. The glass trade, after the removal of the heavy burden imposed upon it, seemed to offer a fair opening for money seeking investment. The demand for glass was so great that the manufacturers were in despair. Glass-houses sprang up like mushrooms. Joint-stock companies were established to satisfy the universal craving for window-panes. And what was the result? Of the four-and-twenty companies existing in the year 1847, there were left, in 1854, but ten. At this time there are but seven in the whole United Kingdom. Two established in Ireland have ceased to exist. In Scotland, the Dumbarton Works, once famous, were closed in 1831, by the death of one of the partners, afterwards reopened, and again closed. The seven now existing are all English. The manufacture of the finer kinds of glass was introduced into England not many years ago from Germany, and German operatives were employed at very high wages. We understand that the English glass is now superior to the German. There is only one plate-glass factory in the United States. It was commenced only two years ago near New York, and we understand that it has met with encouraging success. Soon after the introduction of the business into this country, a very great improvement in the mode of manufacture was introduced. Pallat, in his admirable work on glass, alludes to the American invention in only a few words, and passes it by as of but slight importance; but it has brought about a very great change, and is destined to exert a still greater; in fact, it has revolutionized the whole system of the flint-glass manufacture, simply by mould machines for the purpose of pressing glass into any form. It is well known that glass in its melted state is not in the least degree malleable, but its ductility is next to that of gold, and by steady pressure it can be forced into any shape. The writer has in his possession the first tumbler made by machinery in this or any other country. Great improvement has of course taken place in the machinery, insomuch that articles now turned out by this process so closely resemble cut-glass that the practised eye only can detect the difference. Still, the entire field of improvement is not occupied, and greater advances will yet be made. The tendency, in this particular, has been so to reduce the cost of glass that it has multiplied the consumption at least tenfold; and there can be no reasonable doubt but that, at this period, a much larger quantity of flint-glass is made in this country than in England. The materials composing glass are all of native production, and may be considered as from the earth. The pig lead used is all obtained from the mines in the Western States; ashes from various sources in other States; and silex is also indigenous. The materials consumed yearly, in the manufacture, are something near the following estimate:-- Coal, for fuel, 48,000 tons; Silex, 6,500 " Ash, Nitre, &c. 2,500 " Lead, 3,800 " for the flint manufacture. How much more is consumed by the window-glass manufacturers, the writer is without data to determine. We have recorded the progress of improvement in the manufacture of glass, and now, relevant to the subject, we propose to examine the various improvements in working furnaces and glass-houses. To this end we present to our readers the drawing of a furnace for flint-glass,[1] with the interior of a glass-house as used by the Venetians, at the highest point of the art, in the sixteenth century. [1] See drawing No. 1, at end of book. The workmen in glass will see, that, as compared with the factories of the present day, the Venetians in their instrumentalities were subjected to many difficulties,--they were oppressed by the furnace smoke, and in no way protected from the heat of the furnace, or enabled to breathe fresh atmospheric air; in fact, the impression prevailed in those days that the external air, drawn into the glass-house, was detrimental to the business, and therefore it was most cautiously guarded against. The drawing is taken from an ancient work on glass, and although limited in the view, shows the general plan. The factory wall was conical, and rose like a large chimney, with a few windows for the admission of light. Exposed to the heat of the summer sun of Venice, and of the furnace within, neither the comfort nor health of the workman was secured. The construction of the annealing department shows two tiers of pans, the use of which must have been attended with great loss of materials. Yet, with all the perceptible inconvenience, no material change in construction was made for centuries. The same plan was adopted in France and England, and it is only within the present century that any change has taken place in the latter country. In fact, in the year 1827 an Englishman erected a glass factory on the same plan in the vicinity of New York, which, from its defective construction for this climate, soon passed out of use. The Germans, however, departed from the Venetian plan so far as to place the furnace in a large and well-ventilated building, but without a furnace-cone to carry off the heat and smoke; still a decided improvement was thus effected over the system in use in France and England. The plan referred to shows to the practical workmen of the present day the excessive waste of fuel arising from the construction of the furnace; for the same expenditure of fuel in the American furnace would melt ten times the material produced from the Venetian. It is admitted that the American glass-house is far in advance of the European ones at the present day, in the particulars of capacity, ventilation, comfort of the workmen, and economy in fuel. An impression is very prevalent that glass-making is an unhealthy occupation. It may have been thus in former times; but, as a matter of fact, no mechanical employment is more healthy. Dissipated as glass-makers have been in former days, and careless of their health as they are at present, no better evidence can be adduced to prove the _generally_ healthy character of the employment than the fact that the Glass Manufacturing Company in Sandwich, averaging in their employment three hundred hands, had not a man sick through the influence of the employment, or one die in their connection, for the space of twenty years. Drawing No. 2[2] represents the plan adopted in the French flint-glass furnaces. These at one period were worked by noblemen only,--the labor of the furnace-tender and taker-in being performed by servants, as before stated. The apparel and general style of dress, as indicated by the drawing, shows that more attention was paid to the fashion of the day than to comfort. The form of the furnace being similar to the Venetian shows it to have been subject to the same unnecessary waste of fuel; but it would appear that the French manufacturers had taken one step towards improvement, in using the waste fuel of the furnace to anneal their glass. The Venetians had a separate furnace to anneal their glass, supported by independent fires, as used at the present day. [2] See drawing No. 2, at end of book. The place marked D, over the crown of the furnace, is the door of the annealing oven; but the drawing is so imperfect that the artist does not show by what flues the smoke escapes, or in what way the glass was drawn from the annealing oven; for only the external view of the furnace is given. But it is fair to presume that the plan was the same as still exists in France, and as adopted by a French company now working a flint-glass factory in Williamsburg, near New York; viz.,--the taker-in, so called, mounts by steps to door D and places the articles in iron pans, which are slowly drawn over the furnace and through another door on the opposite side, to allow the glass vessels to cool gradually. The use of this plan is sustained by writers who describe the tools used to carry the glass articles into the upper oven to cool. In connection with the drawings of the ancient glass-furnaces, we deem it proper to give a drawing of glass-makers' tools[3] in use at that period, so that the glass-makers of the present day may observe with what instruments their noble predecessors in the art performed their labor. [3] See drawing No. 3, at end of book. In many of these tools we perceive the same general characters as mark those in use now. In some, improvements have been effected; while others are quite obsolete. It is quite curious to observe the etymology of many of the technical terms of the art in use at the present day. The name of the present polished iron table, _i.e._ the MARVER, is derived from the practice of the Italians and French in using slabs of polished marble. The iron now called the _punty_, from the Italian _ponteglo_. The tool now called _percellas_, from the word _porcello_. In fact, nearly all the technical terms in the glass manufacture, appertaining to the tool or furnace, are derived from the Italian. By referring to the drawing, we see that the tool marked A is the blow-iron, that marked B the punty-iron. Their character plainly indicates that the work made on them must have been confined to small or light articles. C, the scissors, D, the shears, correspond to those used at the present day. The tool marked E was used to finish part of their work. F and G were their large and small ladles,--the small used to take off the then called alkalic salt, showing that they were troubled with an excess of this in their time. The shovel, then called stockle, marked H, was used to carry glass articles to the annealing oven, forks not being then in use. The crooked iron I was used to stir up the metal in the pots. The tool L was used to form or hold large articles, their punty-iron not having sufficient strength. The tool M was used to carry flat articles to the annealing ovens. The tool N was used in refining their alkalic salts, and served to take off the salt as crystallized in course of its manufacture. The workmen of the present day will see that, as before remarked, many tools are not altered in form, while in others there is a decided improvement,--in none more than in the tool E. Tool D is exactly like those now in use; but many new tools have been introduced since that period, rendering most of the old tools useless. Improvements in the form of glass-furnaces, construction of the glass-house, tools, &c., have been very gradual,--more so, in fact, than in almost any other art, when we consider that a period of about four hundred years has elapsed since the furnaces, tools, &c., herein referred to, were in use, and that they remained very much the same until the present century. It is indeed no undue arrogance of claim to say that the very many improvements in furnaces, working machinery, tools, &c. (such as enable the manufacturer here to melt with the same fuel double the quantity of glass that can at present be done in the European furnaces,) are entirely owing to the progress of the art in this country. By the perfection of our machines double the product can be obtained; and although the glass maker is paid at least three times the wages usually paid in Germany or France, we can, in all the articles where the value of the materials predominates, compete successfully with importers of foreign glass; but when the labor on glass constitutes its chief value, then glass can be imported cheaper than it can be manufactured in this country. Essentially, however, we may say, in the realm of art as in that of civilization and progress,-- "Westward the star of empire takes its way." PRESSED GLASS. This important branch of glass-making demands more than a passing notice. Although it is commonly believed here that the invention originated in this country, the claim cannot be fully sustained. Fifty years back the writer imported from Holland salts made by being pressed in metallic moulds, and from England glass candlesticks and table centre-bowls, plain, with pressed square feet, rudely made, somewhat after the present mode of moulding glass. From 1814 to 1838, no improvement was made in Europe in this process, which was confined to common salts and square feet. America can claim the credit of great improvements in the needful machinery which has advanced the art to its present perfection. More than three quarters of the weekly melt is now worked up into pressed glass, and it is estimated that upwards of two million dollars has been expended in the moulds and machines now used in this particular branch of glass-making. This leaves Europe far behind us in this respect. With us there is active competition for excellence. It is, however, conceded that James B. Lyon & Co., of Pittsburg, stand first. To such a degree of delicacy and fineness have they carried their manufacture, that only experts in the trade can distinguish between their straw stem wines, and other light and beautiful articles made in moulds, and those blown by the most skilled workmen. When we consider the difference in the cost between pressed and blown ware, this rivalry in beauty of the former with the latter becomes all the more important to the public, as it cheapens one of the staple necessaries of civilized life. Great credit therefore is due this firm for their success in overcoming difficulties well understood by glass-makers, and doing away with the prejudice of the skilled blowers, who naturally were not inclined to put the new and more mechanical process of manufacturing glass on a par with the handicraft of the old. Lyon & Co. also excel all other American firms in large ware for table services, as well as in the more delicate objects of use. In speaking of the improvements in glass-making in America, we must not overlook what has been done by the New England Glass Company. Convinced of the importance of scientific skill in their business, they secured some years ago the services of Mr. Leighton and his three sons, at a liberal compensation. Besides possessing the best practical knowledge, they had also artistic taste, which enabled them to give elegant finish to their workmanship, and to introduce new and more beautiful patterns into it. They did not neglect, however, the more homely but useful articles; but executed orders for large and heavy objects for druggists' and chemical wares and philosophical apparatus, so satisfactorily as to secure a monopoly in them. Their richly cut, gilded, colored, and ornamental glass is considered equal to European work. John L. Gillerland, late of the Brooklyn Glass-Works, is remarkably skilful in mixing metal. He has succeeded in producing the most brilliant glass of refractory power, which is so difficult to obtain. A gold medal was awarded his glass, in face of European competition, at the Great International Exhibition in London, 1852. In making rich glass, the gaffer or foreman must understand the science of chemistry sufficiently well to mix and purify his materials in the best possible manner, removing all crude or foreign matter, and combining the proper substances into a homogeneous mass. Without this practical experience and knowledge, his glass, instead of being clear and brilliant, and of uniform color, will be dull, and of many hues or shades. It is important also that his personal character be such as to command the respect of the workmen. LENSES. Optical glasses have engaged the attention and investigation of scientific men for centuries. We read of the wonderful exploits of the burning lens of Archimedes, and find the remains of lenses thousands of years old in the ruins of Nineveh, Babylon, and Pompeii. They are of the utmost importance in the science of astronomy. The slow progress made in perfecting them shows the inherent difficulties that exist in obtaining glass of the required purity. One of these is the different specific gravities of the material used. Hence the lower part of a pot of melted glass is of greater specific gravity than the top, causing a tendency to cords or threads, an evil which science has yet to learn to overcome. Not even the large bounty offered by the English Government and the Board of Longitude has been successful in effecting any important improvement in this branch of manufacture. Munich enjoys the reputation of producing the best lenses, and consequently the finest telescopes. Sir Isaac Newton, Gregory, Dolland, Keir, and others adopted lenses made from flint- and from crown-glass, it being necessary to use both in the construction of achromatic telescopes, one possessing as small and the other as great dispersive powers relative to the mean refractive powers as can be procured. But the inherent defect of the lenses still remained. M. Macquer remarks, "The correction of this fault appears therefore to be very difficult." He had tried in vain to remove it by very long fusion and fierce fire. Others have found this by experience not to correct, but to augment the evil. Mr. Keir is of opinion that some new composition must be discovered, which, along with a sufficient refractive power, shall possess a greater uniformity of texture. Since then, it is certain some improvement has been made in the composition for lenses. In an English paper we find the following:--"One of the most remarkable optical lenses of modern manufacture is that produced by Messrs. Chance, English manufacturers, being an attempt by them to improve the manufacture of glass for optical purposes. The diameter is twenty-nine inches, and it is two inches and a quarter thick. It is really not a lens, but a plain disk intended for a lens, should its quality be sufficiently fine. The weight is about two hundred pounds. This piece of glass was inspected, on its first public exhibition, by eminent scientific judges. It was by them examined edgewise, transversely, and obliquely; it was viewed by daylight and by candle-light; it was tested by the polariscope and by other means; and after having been thus subjected to a severe ordeal, it was pronounced to be the largest and finest known specimen of the kind." The promise held out by the foregoing we fear has failed, as in very many previous cases, or the world ere this time would have heard of its success. An achromatic object-glass for telescopes consists of at least two lenses, the one made of flint-glass, and the other of crown-glass. The former, possessing least power of dispersing the colored rays relative to its mean refractive power, must be of greater value than the latter. It is upon this principle that the achromatism of the image is produced, the different colored rays being united into one focus. Flint-glass, to be fit for this delicate purpose, must be perfectly homogeneous, of uniform density throughout its substance, and free from wavy veins or cords. From the foregoing, the reader will see that, as has been said, the chief difficulty which exists in making telescopic lenses arises from want of pure glass. Every attempt to correct this evil has failed; it is well known our best telescopes and like optical instruments have always achromatic lenses, and for photographic purposes achromatic lenses are indispensable. If philosophers and astronomers have with so imperfect lenses attained so much, what may not the astronomer look for when science gives him lenses made from pure glass? If the heavens, by imperfect instruments, have so far been unveiled, to what extent may he not then be able to penetrate the pure ether, and reveal planets and heavenly bodies as yet unknown? We close our reminiscences of Glass and its manufacture, by presenting to our readers a view of an American model glass factory of the present day.[4] By comparing this view with the sketches heretofore given of the early Venetian and French factories, they will perceive the very great improvement which is apparent over the ancient plans, an improvement conducing alike to the health and comfort of the workmen. Thirty years have passed in its development, during which many difficulties arose from the conflicting opinions of the English and German glass-makers; and, in fact, it was not until the proprietors boldly separated themselves from the current and influence of old, and almost fixed opinions, that any decided progress was shown in the development of manufacturing efficiency, or any plan contributing to the health and comfort of the workmen employed. [4] See drawing No. 4, at end of book. It is to be borne in mind that the first glass works in this country were established by the Germans, who used no other fuel than wood, the furnaces for window-glass constructed under their directions being for that fuel only; on the other hand, the English workmen who introduced the making of flint-glass had made use of no other fuel than coal, and the English were therefore obliged to adopt (for the want of coal) the German plan for furnaces, and adapt the same to the making of flint-glass. The house was like the furnace, half English and half German, and from the year 1812, for thirty years, little or no improvement was made in this particular. Year after year the old plan was followed, until necessity paved the way for new plans in the effort to secure a less expensive mode of melting glass. The result has been highly favorable. More than one half has been saved in the melt, annealing leers, and working places, yielding the workmen greater space and facilities in performing their work, and no longer exposing them to the discomfort of extra heat, smoke, and unhealthy gases. These improvements have enabled the American manufacturer to sustain his business in the severe and trying competition with foreign manufacturers, who forced their glass into this country through their agents a few years since, in such quantities, and at such reduced prices, as seriously to affect the prosperity of our artisans; yet, aided as they have been by a tariff directly promoting foreign interest, and by the very low rates of wages paid on the Continent, they have been successfully contended with, and now a home competition has sprung up, reducing prices below a fair standard,--a competition, the result of enterprise, which will, erelong, regulate itself, for we fully hold to the maxim, that competition, honest and well sustained, is the soul and life of business:-- "No horse so swift that he needs not another To keep up his speed." There is no mechanical employment in this country yielding so good returns to the industrious as a good worker in glass, of the present day, can secure in the exercise of his skill. And we may still further say that there is no mechanical branch of industry offering such advantages for the full manifestation of a workman's real skill and industry, if the conventional usages which restrict the work could but be abrogated,--usages tending to a limited amount of work, and consequently making the workman to realize but a limited amount per week. Such workmen, of all others, should be allowed the inherent and inalienable right to work as long, and at such times, as the individual may deem for his comfort and interest. We have expressed the opinion that the manufacture of glass is as yet but in its infancy. The experience of every day confirms the assertion, and illustrates the maxim that "life is short, art is long." The time is not far distant when this country will become, we think, the largest exporter of glass, and the manufacture compose a most important item in every assorted export cargo. In this connection a hint to ship-owners may not be amiss. It is well known that in England, when a ship is put up for a foreign port, it is the custom to rate the freight according to the value of the merchandise,--dry goods paying the highest freight, hardware the next highest, earthen and glass ware the lowest. If our merchants would adopt this plan, very many of our bulky manufactures would find a market abroad; when, however, the same rate is required for a cask of glass ware as for a case of silks or prints, it taxes the latter a small percentage, but practically vetoes the export of the glass. Our task is now ended; our object has been to give a simple and succinct outline of the characteristics and progress of the Glass Manufacture, to suggest such hints as might bear upon the further advance of the art, and the preservation of those practically identified with the manufacture, and, if possible, to attract the attention of those hitherto unacquainted with its nature and history. If we have neglected the maxim that "_those who live in glass houses_," &c., it has not been from the want of honest endeavors to remember it; and if we have contributed either to the instruction or the pleasure of any reader, (and this is our hope,) we shall not regret the hours spent in the preparation of this little work. APPENDIX. RECEIPTS, ETC. There are plenty of receipts for the composition of flint or crystal glass, but no mixture that we know can secure a uniform shade in each pot. The component parts of glass are well known, and the mixer's sure guide is to watch the effect of heat on each pot, for he soon finds the mixture that gives good color in one pot will in another in the same furnace prove bad. If he possesses sufficient knowledge of the chemical causes, he can correct the evil. Among the valuable receipts for rich colors is the following, for RUBY GLASS, which takes lead both in cost and richness:-- Take one ounce of pure gold; dissolve in a glass vessel two ounces pure sal ammoniac acid, and five ounces of pure nitric acid, which will take six to seven days; drop in at a time say one twentieth part of the gold. When the first piece is dissolved, drop in another twentieth portion of the gold, and so on until the ounce of gold is all dissolved. This will require twenty-four hours. Evaporate the solution to dryness. Then prepare in a glass vessel six ounces pure nitric acid, two ounces muriatic acid, and one ounce of highest proof alcohol; mix them well together, and drop in pure grained tin a bit at a time, _but beware of the fumes_. Stir it well with a glass rod; dilute the solution with eighty times its bulk of distilled water; then take the prepared gold, dissolved in a quart of distilled water, and pour it steadily into the solution of tin as above prepared, stirring all the while. Let it settle twenty-four to thirty hours; pour off the water, leave the settlings, pour in two thirds of a quart of water. Stir it thoroughly; let it settle thirty hours; pour off as before, and filter the precipitate through filtering paper. The result is the purple of Crassus. The ounce of gold thus prepared must be well incorporated with the following batch: say thirty-two pounds fine silex, thirty-six pounds oxide of lead, sixteen pounds refined nitre; melt the same in a clean pot, one little used, and smooth inside; when filled in, put the stopper to the pot loose, leaving it slightly open; leave it five or six hours, or time to settle, then a back stopper can be put up. In the usual time it will be ready to be worked out in solid, egg-shaped balls, and exposed to the air to be partially cooled; they are then to be placed in the leer under a strong fire, which will in two or three hours turn them to a red color; then the pans may be drawn slowly to anneal the balls. It is well known to mixers that colored glass is derived from metallic oxides. To obtain the proper color depends on the purity and strength of the metallic oxides. The following receipts have with success been used:-- ALABASTER. To 500 lbs. of batch add 30 " phosphate of soda, 10 " allumine,--_i.e._ calcined alum, 3 " calcined magnesia. BLACK. To 1400 lbs. of batch add 180 " manganese, 100 " calcined iron scales, made fine, 20 " powdered charcoal, 10 " arsenic. CANARY. To 100 lbs. of batch add 8 ounces best oxide of uranium, 1 dr. oxide of copper. The common colors of purple, blue, emerald, or green, are too well known to require to be repeated here. The following receipt for crystal glass is on the European standard, viz.:-- 1200 lbs. silex, 800 " red lead, 440 " pearlash, 50 " nitre, 10 " phosphate of lime, 10 oz. white oxide of antimony, 24 " manganese, 32 " arsenic, 20 " borax. GERMAN SHEET GLASS. 400 lbs. silex, 130 " soda, 126 " hydrate of lime, 4 " charcoal, 7 " nitrate of soda, 4 " arsenic, 1 " manganese. Gold-colored spangles may be diffused through the glass by mixing gold-colored talcs in the batch. AGATE. To 150 lbs. flint batch add 10 " phosphate of lime, 6 " arsenic. BLACK. 600 lbs. flint batch, 40 " manganese, 46 " oxide of iron. LIGHT EMERALD GREEN. 200 lbs. flint batch, 2-1/2 " iron filings, calcined, 1/2 " antimony. ORIENTAL GREEN. 110 lbs. flint batch, 1 " oxide of uranium, 2 oz. carbonate of copper. OPAL. 500 lbs. batch, 60 " phosphate of lime, 4 " arsenic, 20 " nitrate of soda. Said to turn without cooling. William Gillender, of England, gives the following receipt for Bohemian Red, or Ruby:-- Sand, 62 lbs. Lead, 76 " Nitre, 22 " Antimony, 8 oz. Manganese, 3 " Add one ounce of purple of Crassus to every eighty pounds of the above batch. WAX RED. To 15 lbs. flint batch add 1 " raw brass, 3/4 " crocus martus. This he says is very good. TURQUOISE. To 1100 lbs. flint batch add 90 " phosphate of lime, 15 " arsenic, 15 " calcined brass dust. VIOLET. To 100 lbs. flint batch add 1 " calcined brass, 1-1/2 " zaffre. Receipts for window-glass are as numerous as for flint. The following are in general use in England, so says Gillender:-- CROWN GLASS. Sand, 1400 lbs. Quick lime, 480 " Sulphate of soda, 560 " Charcoal, 25 " PLATE GLASS. Sand, 300 lbs. Sulphate of soda, 450 " Quick lime, 100 " Nitre, 25 " Charcoal, 5 " DIAMOND GLASS. Four pounds of borax, one pound of fine sand; reduce both to a subtile powder, and melt them together in a closed crucible set in an air furnace, under a strong fire, till fusion is perfect. Let it cool in the crucible, and a pure, hard glass, capable of cutting common glass like a diamond, which it rivals in brilliancy, is produced. LEAD. Lead is an important and costly ingredient of flint-glass, used as a protoxide, either as litharge or red lead, and should be perfectly pure, for the presence of any other substance or metal will be shown in the color of the glass. Consequently, the purity of the glass depends mainly on the quality of the metallic lead and its being well manufactured. The writer believes he was the first person in the United States, aided by a director of the New England Glass Company, to build a lead furnace. This was in 1818. His only guide was a volume of "Cooper's Emporium of Arts and Sciences," which furnished a plan on a very limited scale. The furnace proved successful, and enabled the Company to continue their manufacture of glass at a period when no foreign red lead was to be procured. They enlarged their works, until they have become the most important in the country; while for over thirty years they monopolized the business in all its branches, from the highest qualities of pure Galena and painter's red lead to common pig lead. In manufacturing metallic lead, its weight is materially increased by the absorption of oxygen gas. In 1847 the writer made many test experiments, one as follows: 660 pigs of blue lead, weighing 45,540 pounds, turned out from the ovens 48,750 pounds of litharge,--an increase in weight of 3210 pounds. The cost of labor was $65.50; fuel, $86.50; engine power, $17.50; total, $169.50; and the market value of the excess in weight of the lead was $250, showing a satisfactory profit to the company for their outlay in this branch of their business. Chemistry gives the increase in course of manufacture: In protoxide state, 7 per cent.; in deutoxide state, 11 per cent.; in tritoxide, 15 per cent. Muriatic acid will detect iron in lead, on dissolving a small piece of lead in the acid. If colorless, it is good. Nitric acid will detect if there is cobalt in the lead, by adding to the acid half the quantity of high-proof alcohol. If present, the evidence is soon seen. Some use the following as more direct:--In a small evaporating glass dish place say one ounce of lead; cover it with muriatic acid; dissolve the lead over a spirit lamp, add a little water, and let it settle; draw it off into another glass vessel, and add five or six drops of the solution of potash. If the lead is suitable for glass-makers, the solution will be of a light, clear, greenish color; if of a blue or purple shade, it is not suitable for flint-glass. SAND, OR SILEX. In the manufacture of glass it is essential that the silex should be perfectly pure, as the slightest mineral taint affects the color. At first the New England factories got their sand from Demerara, brought as ballast, and the quality was good. During the War of 1812 this source of supply was cut off, but Plymouth beach provided for the wants of the manufacturers, until a better sand was discovered at Morris River, N.J., though not up to the full requirement of the art. For ten years past, Berkshire County. Mass., has furnished sand; the best quality is owned by G. W. Gordon, Esq. By thorough washing, and passing it through fine sieves, and proper packing, he now commands the market, and delivers it ready for use. The purity has been tested, as shown by the following extract from a report by Professor A. A. Hayes, M.D., of Boston, Massachusetts State Assayer, of the result of analyses of three samples of Berkshire sand, taken from three different locations owned by Mr. Gordon, viz.:-- "For the manufacture of glass, the slight amount of earth, in mica and tourmaline, contained in these samples, is of no account, the impurity being such oxides as color glass. The analyses therefore give only the proportion of coloring oxides; and, for simplicity of statement, the total weight of coloring oxide in each sample is determined in one part or pound. "Sample B analyses: 4000 parts of this sample contain one part of oxide of iron. Sample C analyses: 3333 parts of this sample contain one part of oxide of iron. Sample P analyses: 3460 parts of this sample contain one part of oxide of iron. "Sample B is equal in purity to the best sand known as a material for glass, in this or any other country." FURNACES. Next to pots, furnaces are most important for the success of a glass manufactory. Long ago it was seen that the old English plan was defective. They consumed coal at an extravagant rate, though this was not a serious drawback in England, because the furnaces were located near coal-mines, and run with a quality called slack, not otherwise merchantable. English furnaces were constructed with reference to durability, usually eight feet in diameter at the interior base, and six feet clear at the crown. This rule was followed in this country until 1840. The writer, having occasion to build an extra furnace, adopted the novel plan of one fourteen feet diameter at the base in the clear and only five feet at the crown, braced by binders, with cross-ties to prevent lateral expansion, which was a success. A furnace on the old plan consumed 2575 bushels of coal weekly, and refined only 38,000 pounds of raw material. The new refined 35,000 pounds, with a consumption of only 2000 bushels of coal. Since then a further decrease in consumption of coal has been produced by the use of the Delano patent, which feeds the furnace by forcing up the coal at the bottom of the burning mass, thus consuming the entire smoke, and obviating the necessity of wheeling coal on the glass-house floor and impeding the workmen. It also does away with all danger to the pots in feeding the fires. Besides these great advantages, it distributes a regular and uniform heat to each pot, causing the pots to last much longer, and fusing the metal better,--important items to mixers. From three to five tons of fuel is the weekly saving in a first-class furnace. It is of vital importance to obtain pots that will last a reasonable time. Clays of the finest quality are essential. Each piece must be freed from any foreign matter, particularly sulphate of iron, which often occurs. The burnt and raw clay should be well mixed, wet, and frequently kneaded, or trod over by the naked feet. Tenacity must be secured, sufficient that a roll twelve to eighteen inches long can be suspended, and hold firmly together by its own adhesiveness. The next point is to make the pots free from air blisters, all portions being compact; then to dry them thoroughly, which requires great care on account of the inequality of the different parts. Pot-makers are not agreed as to the value of different clays, and the use and proportion of raw to burnt shells. Some use sixteen parts raw to eleven burnt, some fifty-five raw to forty-five burnt, some equal proportions of each. Manufacturers have mainly depended upon imported clays, but the Western glass-makers have used Missouri clay with success. In the east it has not yet come into general use. Of the imported, that from Stowbridge is considered best. Garnkerk is a strong clay, and, if well selected, will rival any other. The analyses are for STOWBRIDGE, Silica, 64 parts, Alumina, 20 " Lime, 1 " Iron, 3 " GERMAN, Silica, 46 parts, Alumina, 34 " Iron, 3 " GARNKERK, Silica, 53 parts, Alumina, 43 " Lime, 1 " Iron, 1 " FRENCH, Silica, 40 parts, Alumina, 31 " Iron, 3 " WESTERN, Silica, 49 to 52 parts, Alumina, 31 to 32 " Iron, 2 to 4 " FUEL. This subject deserves special notice. We have said that the New England manufacturers at first used wood only, which was prepared by being split into equal lengths, with an average diameter of two inches, and then kiln-dried to dispel the sap and moisture. This fuel was supplied to the furnace at opposite fire-holes, a stick at a time, which was a laborious and heating process. Subsequently, a furnace was built at South Boston, over a cave, and unkilned wood was used in clefts. This saved one quarter in fuel, but it used up the pots so rapidly as to prove to be no economy in the end. After the development of the Virginia coal mines, our furnaces were altered to use coal, which proved to be more convenient and less costly than wood. The Pictou and Cumberland mines also increased the supply; and at present all the furnaces in New England, with one exception, are run with this last-named fuel. The various experiments made to economize fuel for the "glory-holes," as the workmen call the working places above the furnace, are well known. For many years the prepared wood we have spoken of was used. Then resin in a powdered state was added, which was both inconvenient and dangerous,--it having caused the destruction by burning of two glass-houses. This risk was finally overcome by the introduction of an invention which used it in a liquid state. But the demand for resin became so great as soon to more than double its price. This led to the substitution of coal tar, which was in use until science discovered its latent virtues for other purposes, and largely increased the original cost of the material. Indeed, at first the gas companies had considered it of no value, and had thrown it away by thousands of barrels. Combined with dead oil it is still used by glass-makers, but at greatly enhanced prices. The Cape Cod Glass Company have had in use for several years a Delano patent furnace-feeder, which enables them to use both hard and soft coal, as either is cheapest, and consumes the smoke and gas of either fuel, thus doing away all annoyance to the neighborhood. Theretofore every attempt to run working places with hard or soft coal had failed on account of the noxious gases set free, which injure the color of the glass. But owing to the intense heat created by the Delano patent, the furnace consumes these gases, and gives a quick fire polish to the various articles finished therein. As our native supplies of hard and soft coal are inexhaustible, there is no likelihood of an increase in the price of the present fuel so as to necessitate, as heretofore, a substitution of some cheaper article, especially as the discovery of petroleum tends to cheapen coal by a diversion of a portion of its consumption to that useful mineral oil. USEFUL ITEMS. A bushel of English coal weighs 80 pounds: of Virginia coal, 93 pounds; of Pictou, 76 pounds; of Cumberland, 84 pounds; of red ash, hard, 84 pounds. Crude saltpetre, refined, loses nine per cent. Chemists estimate that one hundred pounds of pearlash contain thirty per cent. carbonic acid. In refining, it loses on the average fifteen per cent. in weight. Phosphate of soda brightens glass. Borax brightens, but hardens glass. Twenty-five silver dollars refined will give thirty-seven ounces of nitrate of silver. A square foot of furnace clay weighs one hundred and twenty pounds. Alum, calcined, loses in weight sixty per cent. Crude flint batch, melted and ladled out, loses in the average fifteen per cent. in weight. Hard coal will measure forty cubic feet to a gross ton. Glass in water. There are some peculiar phenomena connected with hot glass and water. If a ball of red-hot iron is placed in a vessel containing cold water, the latter is quickly agitated. But a ball of melted glass of equal weight dropped in cold water will produce no immediate agitation. The water will remain for some time quiescent; but when the glass is cooled to about half its highest temperature, it agitates the cold water violently. Technical terms, descriptive of glass, such as crystal, flint, tale, may be derived from these facts: the French used for their base crystal stones, burnt and ground fine; in England they had recourse only to flint stone, treated the same as the French used their blocks of crystal; tale was derived from the mode of selling, the best glass being sold only by weight, while light articles were sold tale. [Illustration] 
50079	----	Transcriber's Note: Inconsistent hyphenation and spelling in the original document have been preserved. Obvious typographical errors have been corrected. Italic text is denoted by _underscores_ and bold text by =equal signs=. D'Appligny was changed to D'Apligny. Gallium was changed to Galium. Page 132: a "Note" was anchored, and added to the footnote sequence. Inconsistent punctuation and capitalization of lists, chapter headings, and footnotes was retained. The listed Errata were corrected. A BOOK ON VEGETABLE DYES BY ETHEL M. MAIRET A.D. 1916 PUBLISHED BY DOUGLAS PEPLER AT THE HAMPSHIRE HOUSE WORKSHOPS HAMMERSMITH W Price 5s. net. _PRINTED by DOUGLAS PEPLER at DITCHLING in the COUNTY of SUSSEX & PUBLISHED BY HIM AT THE HAMPSHIRE HOUSE WORKSHOPS HAMMERSMITH ON S. JOHN THE BAPTIST'S DAY A.D. MDCCCCXVI_ PUBLISHER'S NOTE IN PRINCIPIO ERAT VERBUM ET VERBUM ERAT APUD DEUM ET DEUS ERAT VERBUM. _Sc. Joannem_ 1.1. VIDITQUE DEUS CUNCTA QUÃ� FECERAT: ET ERANT VALDE BONA. _Genesis._ 1.31. MAN uses these good things, and when MAN first discovers how to make anything, that thing which he makes is good. For example: this book is printed upon one of the first iron presses to be made in this country. The press is a good press; it would be difficult to make a press which would enable the printer to print more clearly. The wooden press was a good press & the printing from it has not been surpassed. Further, this quality of goodness of a first discovery may persist for many years. But there is a tendency to avoid _Quality Street_. We are choosing rather _Quantity Street_ & the Bye paths of _Facility & Cleverness_; we have become accustomed to the hum of the _Time & Labour saving_ machinery; and we are in danger of forgetting the use of good things: indeed the tradition & practice of goodness has been lost in a considerable number of trades. For instance: a carpenter has become so used to buying his timber in planks from a yard that he has nearly forgotten its relation to the tree. The man who works to designs conceived by somebody else with wood sawn by another man's machine must be deprived of the natural strength of the tree. And this is not an exception to, but an example of, the way we are choosing to do things. It is impossible to buy linen as good as that normally used by every tradesman in the XVIII century. It is nearly impossible to get cloth, paper, bread, beer, bacon and leather equal to that in common use 150 years ago. IN VIEW OF THE BEGINNING it is desirable to record what still survives of the traditions of making good things; and I shall endeavour to publish the instructions & advice of men & women who still follow these good traditions. Douglas Pepler. CONTENTS PAGE I. INTRODUCTION 1 II. WOOL, SILK, COTTON AND LINEN 11 III. MORDANTS 24 IV. BRITISH DYE PLANTS 37 V. THE LICHEN DYES 45 VI. BLUE 63 VII. RED 87 VIII. YELLOW 107 IX. BROWN AND BLACK 122 X. GREEN 133 CHAPTER I. Dyeing has almost ceased to exist as a traditional art. In this 20th century the importance of colour in our lives seems to be realized less and less. It has been forgotten that strong and beautiful colour, such as used to abound in all every day things, is an essential to the full joy of life. A sort of fear or nervousness of bright colour is one of the features of our age, it is especially evident in the things we wear. There is unfortunately good reason for it. We fear bright colour because our modern colours are bad, and they are bad because the tradition of dyeing has been broken. The chemist has invaded the domain of the dyer, driven him out and taken over his business, with the result that ugly colour has become the rule for the first time in the history of mankind. It is not that chemists never produce beautiful colour. Dyeing as a chemical science has not been studied for the last 50 years without producing good results. But there is this great difference between the chemical commercial dyes and the traditional dyes--that with the commercial dyes it is very easy to produce ugly colours, the beautiful colour is rare; but with traditional dyes it is difficult to make an ugly colour, and good colour is the rule. It was in 1856 that mauve was produced from coal tar by an English chemist, and this began a new era in dyeing. The discovery was developed in Germany, and the result was the creation of a science of chemical colouring. The advantages of the new colours were ease and simplicity of use, general reliability with regard to strength and composition, and certainty in reproducing the same colour again without trouble. With regard to fastness, to light and to washing there is practically little difference between the two. It is more the method by which they are dyed and not the dye itself (although of course in some cases this is not so) that determines their fastness. The natural dyes are more trouble and take longer time to prepare. Chemical colours can be dyed now as fast as the natural colours, although at first this could not be done. Some of the chemical colours as well as the natural, are not fast to light and washing, and ought never to be used; but there are natural colours, such as madder, some of the lichens, catechu etc., which are as fast as any chemical dye, if not more so. BUT there is this general difference between the results of the two methods,--that when a chemical colour fades it becomes a different colour and generally a bad one: when a natural colour fades, it becomes a lighter tone of the same colour. Since the middle of the 19th century our colour sense has been getting rude shocks. At first came the hideous aniline colours, crude and ugly, and people said, "How wonderful, are they really made out of coal!" They were told to like them and they did, and admired the chemists who made them. Then came more discoveries, and colour began to go to the opposite extreme, and the fashion was muddy indeterminate colours--'art' colours as they were called, just as remote from pure good colouring in one direction as the early aniline colours were in the other. We are now emerging from the mud colours, as I would call them, to the period of the brilliant colouring of the Futurist. Here we have scientific colouring used with real skill. The Futurist has perhaps indicated a possible way in which chemical colours may be used by the artist and is teaching people the value of simple combinations of brilliant colour. And yet do they satisfy the artist? Are they as beautiful as the colours in a Persian Khelim? Is there a blue in the world as fine as the blue in a Bokhara rug, or a red to touch the red of a Persian brocade or Indian silk?--the new fresh colours as they come out of the dyer's vat, not as they are after years of wear and tear, though that is beautiful enough. And yet they are not more beautiful than the colours once made by dyers in England. They are as brilliant as the chemical colours, but they are not hard and unsympathetic and correct. They are alive and varied, holding the light as no chemical colour can hold it; and they are beautiful from their birth to their old age, when they mellow, one with the other, into a blend of richness that has never yet been got by the chemical dyer and never will be. Perhaps it is the scientific method that kills the imagination. Dealing with exactly known quantities, and striving for precise uniformity, the chemist has no use for the accidents and irregularities which the artist's imagination seizes and which the traditional worker well knew how to use. William Morris says that "all degradation of art veils itself in the semblance of an intellectual advance," and nothing is truer than this with regard to the art of dyeing. As a tradition it is practically dead in Britain, and is threatened with gradual extinction all over the world. It will not recover itself as an art till individual artists set themselves to make beautiful colours again, and ignore the colour made for them by commerce and the chemists. Handicraft workers should make their own colours. Leather workers should dye their own leather, the embroiderers their own silks and wools, the basket makers their own materials, the weavers and spinners their own flax, cotton and wool; and until they do this the best work will not be done. This is the necessity for the present. _If any craft worker wants sound colour he must make it for himself, he cannot get it done for him by artists._ The hope for the future is that dyeing may be reinstated as a craft, co-operating with the other crafts and practiced by craftsmen. The way to beauty is not by the broad and easy road; it is along difficult and adventurous paths. Every piece of craft work should be an adventure. It cannot be an adventure if commerce steps in and says "I will dye all your yarn for you; you will always then be able to match your colour again; there need be no variation; every skein shall be as all the others; you can order so many pounds of such a number and you can get it by return of post; and you can have six or seven hundred shades to choose from." It is all so easy, so temptingly easy,--but how DULL! the deadly yards of stuff all so even and so exactly dyed; so perfect that the commerce-ridden person says, "this is almost as good as the stuff you can buy in a shop, it is as perfect as machine made stuff." What would have been the use of all this to the great colourists of the world, the ancient Egyptians, the mediæval Italians or the great Oriental dyers? They could not get six hundred shades to order; six was more like their range, they did not need more, and in those they could not command precise uniformity. They knew that the slight variations caused by natural human methods add to the beauty and interest of a thing, and that a few good colours are worth any number of indifferent ones. It is quite certain that a great many of the handicrafts that have depended upon commercial dyes would produce _infinitely better work_ if they dyed their raw material themselves. It may be objected that life is not long enough; but the handicrafts are out to create more life, not out to produce quantity nor to save time. The aim of commerce is material gain; the aim of the crafts is to make life, and no trouble must be spared to reach that end. It must always be before the craft worker. Dyeing is an art; the moment science dominates it, it is an art no longer, and the craftsman must go back to the time before science touched it, and begin all over again. The tradition is nearly lost in England. It lingers in a few places in Scotland and Ireland. In Norway, Russia, Central Asia, India and other places where science has not entered too much into the life of the people, it is still practiced. Is dyeing as a tradition to be doomed, as traditional weaving was doomed? Yes, unless it be consciously studied again and remade into an art. This book is intended for the use of craftsmen and others who are trying to dye their materials by hand and on a small scale. Information and recipes, useful to such workers, are to be found in books and pamphlets dating onwards from the 17th century, and in this book I have drawn largely upon these sources of dyeing knowledge, as well as upon the traditions still followed by present workers, and upon the experience of my own work. All dyeing recipes, however, should guide rather than rule the worker; they are better applied with imagination and experience than with the slavishness of minute imitation. Every dyer should keep a record of his experiments, for this will become invaluable as it grows, and as one thing is learnt from another. The ideal way of working is not by a too rigid accuracy nor by loose guess-work, but by the way which practice has proved best: nevertheless, some of the greatest dyers have done their work by rule-of-thumb methods just as others have certainly worked with systematic exactness. The dyer, like any other artist, is free to find his own methods, subject to the requirements of good and permanent craftsmanship, provided that he achieves the effects at which he aims. But it is supremely important that he should aim at the right effects; or, rather, at the use of the right materials, for if these are right the effects may safely be left to take care of themselves. In order to develop the taste and temperament of a good colourist, it is necessary to use good colour and to live with good colour. In this book I attempt to show where good colour can be obtained. But one may begin to live with good colour which has been found by others. This part of the dyer's education is not prohibitively costly, even in these days of inferior colour. Indian and Persian embroideries are still to be obtained, though care must be taken in their selection, as most modern pieces are dyed with chemical dyes and are very ugly. Persian Khelim rugs are cheap and often of the most beautiful colours. Russian embroideries and woven stuffs, both old and new, are obtainable, and are good in colour, as are most of the embroideries and weavings of Eastern Europe and the East. What are popularly known as "coffee towels" are often embroidered in the finest coloured silks. Bokhara rugs and embroideries are still to be purchased, and many of the weavings of the far East, although, alas, very few of the modern ones are of good colour. I would say to dyers, do not be satisfied with seeing beautiful coloured stuffs in museums. It is possible still to get them, and to live with a piece of good colour is of much more use than occasional hours spent in museums. CHAPTER II. WOOL SILK COTTON LINEN Various kinds of wool. Wool from goats. Fleeces. Wool dyeing. Scouring of wool. Silk, preparation for dyeing. Cotton, cleansing and galling of. Indian methods of preparing cotton and linen for dyeing. BANCROFT on the preparing of cotton and linen for dyeing. Linen. On water for dyeing. ON WOOL.--The quality of wool varies considerably. British wools are of various kinds:-- _Highland, Welsh and Irish_ wools are from small sheep, not far removed from the wild state, with irregular short stapled fleeces. _Forest or Mountain sheep_ (Herdwick, Exmoor, Blackfaced, Limestone, Cheviot) have better wool, especially the Cheviot which is very thick & good for milling. _Ancient Upland_, such as South Down, are smaller sheep than the last named, but the wool is softer and finer. _Long Woolled sheep_ (Lincolns, Leicester) with long staple wool (record length, 36 in.) and the fleeces weighing up to 12 lbs. The Leicester fleece is softer, finer and better than the Lincoln. To the end of the 18th century _Spanish wool_ was the finest and best wool in the world. Spanish sheep have since been introduced into various countries, such as Saxony, Australia, Cape Colony, New Zealand, and some of the best wools now come from the colonies. _Alpaca, Vicuna and Llama_ wools are obtained from different species of South American goats. _Mohair_ is obtained from the Angora goat of Asia Minor. _Kashmir_ wool is got from the Thibetan goat. _Camel_ hair is the soft under wool of the camel, which is shed annually. It is of a brown colour. The colour of wool varies from white to a very dark brown black, with all shades of fawn, grey and brown in between. The natural colours are not absolutely fast to light but tend to bleach slightly with the sun. Fleeces are of various kinds, the principal being: _Lambs_, 3 to 6 months growth, the finest, softest and most elastic of wool. _Hogs and Tegs_: the first shearing of sheep that have not been shorn as lambs. _Wethers_: all clips succeeding the first shearing. Wool comes into the market in the following condition. 1) _In the grease_, not having been washed and containing all impurities. 2) _Washed_, with some of the grease removed and fairly clean. 3) _Scoured_, thoroughly cleaned & all grease removed. ON WOOL DYEING.--There are four principal methods of dyeing wool. 1st.--The wool is boiled first with the mordant and then in a fresh bath with the dye. This method of dyeing is the most satisfactory and gives brighter and faster colours than the other methods. It is not necessary to throw away the solution after the mordanting has been done, but it can be replenished for a fresh lot of wool; a separate bath is used for the dye. 2nd.--The wool is boiled first with the dye and, when it has absorbed as much of the colour as possible, the mordant is added to the same bath, thus fixing the colour. This is called the "stuffing" and "saddening" method; the "stuffing" being the boiling of the wool with the dye stuff and the "saddening" the fixing the colour by the mordant. A separate bath can be used for each of these processes, in which case each bath can be replenished and used again for a fresh lot of wool. 3rd.--The wool is boiled with the mordant and dye in the same bath together. The colour, as a rule, is not so fast & good as with a separate bath, though with some dyes a brighter colour is obtained. 4th.--The wool is mordanted, then dyed, then mordanted again (saddened). This method is adopted to ensure an extremely fast colour. The mordant in this case should be used rather sparingly. Wool can be dyed either in the fleece, in the yarn or in the woven cloth. Raw wool always contains a certain amount of natural grease. This should not be washed out until it is ready for dyeing, as the grease keeps the moth out to a considerable extent. Hand spun wool is always spun in the oil to facilitate spinning. All grease and oil must be scoured out before dyeing is begun, and this must be done very thoroughly or the wool will take the colour unevenly. The principal detergent known from earliest times is stale urine. In the Highlands this is used in the proportion of 1 part to 5 of water. It is the best scouring agent and leaves the wool soft and elastic. Carbonate of soda is also used. But a good pure soap is the most convenient scouring agent. A suds should be made with hot water, and the wool, which has been soaked in warm water previously, should be well squeezed and worked in the suds till all the grease is removed. This should be done two or three times if needed, and then the wool rinsed out thoroughly in clean water. Soda is apt to make the wool harsh and should be avoided. A little Ammonia added to the washing water helps. To prevent yarn felting when it is scoured, it should be first steeped in hot water and left to cool. Soft soap is best for long fine wool. Urine for short wools; or urine and soda ash. _Another way of cleansing wool._ Make a hot bath of 4 parts water and 1 part urine, enter wool, teasing it and opening it out to admit the full action of the liquid. After 20 minutes immersion, remove and allow to drain. Then rinse in clear running water and allow to dry. Use no soap. The liquid can be used again. The wool often loses one fifth of its weight in the process of washing. _To soften yarn_--In a gallon of hot water dissolve half pound of common soda, then add half-pint of sweet oil and stir well. A little of this added to the washing water, for some colours, will soften the yarn. _To bleach wool_--The wool is suspended in a closed room on hoops, and under the wool chafing dishes are placed with lighted coals on which powdered sulphur is cast. The room door is afterwards shut so that the smoke may be the longer retained to act on the wool, which is to remain until it is entirely whitened. ON SILK.--There are two kinds of silk, 1) _raw silk_ (reeled silk, thrown silk, drawn silk), and 2) _waste silk_ or spun silk. Raw silk is that directly taken from the cocoons. Waste silk is the silk from cocoons that are damaged in some way so that they cannot be reeled off direct. They are therefore carded and spun, like wool or cotton. Silk in the raw state is covered with a silk gum which must be boiled off before dyeing is begun. It is tied up in canvas bags and boiled up in a strong solution of soap for three or four hours until all the gum is boiled off. If it is yellow gum, the silk is wrought first in a solution of soft soap at a temperature just below boiling point for about an hour, then put into bags and boiled. After boiling, the soap is well washed out. Generally speaking, the affinity of silk for dyes is similar but weaker in character to that of wool. The general method for dyeing is the same as for wool, except that in most cases lower temperatures are used in the mordanting. In some cases, soaking in a cold concentrated solution of the mordant is sufficient. The dyeing of some colours is also at a low temperature. _Of the preparation of raw silk._ For every pound of raw silk, take ¼ lb. of soap; first put the silk into a bag, or so make it up that tangling may be prevented, then let it boil together for 2 hours, after which it must be very well cleansed, and so it is ready to dye all sorts of colours, being first allomed.[1] _How the boiled silk must be allomed._ In proportion to every pound of silk, take ¼ lb. of Allom, melt in a little kettle or skillet, and when melted, throw it in to a tub of water, into which put the silk to steep, where let it lie a whole night.[1] _To soften silk after dyeing._ Into a large vessel nearly full of water, a solution of soap is poured, in the proportion of from 4 to 5 lbs. of soap for every 110 lbs. of silk. The solution of soap is strained through a cloth into the water and well mixed. The silk is then introduced & left for about quarter of an hour after which it is wrung out and dried. ON COTTON.--Cotton is the down surrounding the seeds in pods of certain shrubs and trees growing in tropical and semi-tropical countries. It was first introduced into Europe by the Saracens and was manufactured into cloth in Spain in the early 13th century. Cotton cloth was made in England in the early 17th century. The colour of cotton varies from deep yellow to white. The fibre differs in length, the long stapled being the most valued. Cotton is difficult to dye and requires a special preparation. It is first boiled with water till thoroughly softened and wetted. Then alumed in the proportion of 1 of alum to 4 of the cotton (see page 28). It is then galled. The galling is done with different proportions of gall-nuts and other astringents (such as tannic acid, myrobalams, sumach, catechu) according to the quality of the astringents and the effect wished to be obtained. If gall-nuts are used they are bruised, then boiled for about two hours in a quantity of water. The bath is then allowed to cool till the hand can bear it. The cotton is worked well in this solution and then left for 24 hours. After which it is wrung out and dried. Cotton is sometimes boiled in sour water in order to cleanse it: sometimes an alkaline ley is used: the cotton must be boiled in it for 2 hours, then wrung out and rinsed in clean water and dried. Cotton dyeing has been carried on for centuries in the East. In India "before a cloth is ready to be dyed with a fast colour, it has generally to undergo a preliminary process of preparation more or less elaborate, the different stages of which may be recited as washing, bleaching, dunging, galling, aluming, or mordanting, and again washing." (_A Monograph on dyes and dyeing in the Bombay Presidency_, by C. G. H. Fawcett, 1896.) It is washed first of all to remove all impurities, whether those naturally belonging to the fibre or those purposely introduced during the processes of spinning and weaving. The bleaching removes grease, etc. This is done in India by the sun, air and moisture. The dunging process consists of passing the cotton through a hot solution of cow dung, which renders the dye fast. This is sometimes replaced by substitutes, such as the phosphates of soda and lime, silicates of soda, etc. The next operation of galling is an important step in the Indian process of dyeing. It is applied to cotton, linen and silk. Vegetable infusions containing tannin are applied to the cloth. Those mostly used are myrobalams, pomegranate rind, tamarisk galls, and pistachio galls. The cloth is then alumed, washed, and is then ready to be dyed. _Bancroft_ says:--"The fibres of linen or cotton when spun or woven are prepared for the dyer by being first boiled in water with a suitable proportion of potash (which for linen should be made caustic, in order that it may act more strongly upon the oily and resinous matters abounding in flax) and afterwards bleached by exposure upon the grass to sun and air. But as this operation commonly leaves a portion of earthy matter in the linen or cotton, it ought to be soaked or steeped in water soured by sulphuric acid, to dissolve and remove this earthy matter, taking care afterwards to wash or rinse off the acid." A few of the natural dye stuffs are capable of dyeing cotton direct, without a mordant, such as Turmeric, Barberry bark, safflower, annatto. For other dyes cotton has a special attraction, such as catechu, fustic, logwood. ON LINEN.--Linen is flax, derived from the decomposed stalks of a plant of the genus of Linum. It grows chiefly in Russia, Belgium, France, Holland, and Ireland. The plants after being gathered are subjected to a process called "retting", which separates the fibre from the decaying part of the plant. In Ireland and Russia this is usually done in stagnant water, producing a dark coloured flax. In Belgium, Holland and France, retting is carried out in running water, and the resulting flax is a lighter colour. Linen is more difficult to dye than cotton, probably on account of the hard nature of the fibre. The same processes are used for dyeing linen as for cotton. "Linen thread is dyed in the same manner as cotton, only, that previous to its being purged like cotton thread, it is usual to boil it in water, adding for every pound of thread a quarter pound of chopped sorrel. Oil of vitriol is, however, more convenient and better than sorrel."--D'Apligny. _To Bleach Linen._--(For 13 to 15 yards linen) Boil ½ lb. soap and ½ lb. soda in a gallon of water. Put it in a copper and fill up with water, leaving room for the linen to be put in. Put in the linen and bring to the boil. Boil for 2 hours, keeping it under the water and covered. Stir occasionally. Then spread out on the grass for 3 days, watering it when it gets dry. Repeat this boiling and grassing for 3 weeks. Your linen is then pure white. _To bleach linen a cream colour._--Boil ½ lb. soap and ½ lb. soda in a gallon of water. Fill copper up with water and put in linen. Boil for 2 hours. Repeat this once a day for 4 days. The linen should not be wrung out but kept in the water till ready to be put into the fresh bath. ON WATER.--A constant supply of clean soft water is a necessity for the dyer. Rain water should be collected as much as possible, as this is the best water to use. The dye house should be by a river or stream, so that the dyer can wash with a continuous supply. Spring and well water is as a rule hard, and should be avoided. In washing, as well as in dyeing, hard water is altogether injurious for wool. It ruins the brilliancy of colour, and prevents the dyeing of some colours. Temporary hardness can be overcome by boiling the water (20 to 30 minutes) before using. An old method of purifying water, which is still used by some silk and wool scourers, is to boil the water with a little soap, skimming off the surface as it boils. In many cases it is sufficient to add a little acetic acid to the water. _Berthollet_ says,--"Whenever, therefore, a water is limpid, when its flow is constant, when it has no sensible taste, and dissolves soap well, it may be regarded as very proper for dyeing." He also goes on to say that for correcting water that is bad, sour water is principally used, that is, water in which bran has been fermented. FOOTNOTE: [1] From a dye book of 1705. CHAPTER III. MORDANTS Definition of mordant. The principal mordants. The mordanting of silk and wool. Of linen and cotton. Astringents for cotton. Alum. Various examples of using alum for wool, silk, cotton and linen. Iron. Examples of iron mordants. Tin. Examples of tin mordants. Chrome. Examples of chrome mordants. Copper. Examples of copper mordants. General observations. Tannin and the galling of cotton and linen. Examples of various galling processes. MORDANTS.--Dyes are divided into two classes. First, the _substantive_ dyes, which give their colour directly to the material with which they are boiled: and second, the _adjective_ dyes, as they are sometimes called. These latter include the greater number of dyes and require the use of a mordant to bring out their colour. There are thus two processes concerned with the dyeing of most colours; the first is mordanting and the second is the colouring or actual dyeing. The mordanting prepares the stuff to receive the dye--(_mordere_, to bite.) The early French dyers thought that a mordant had the effect of opening the pores of the fibres, so that the dye could more easily enter; but according to Hummel and later dyers the action of the mordant is purely chemical; and he gives a definition of a mordant as "that body, whatever it may be, which is fixed on the fibre in combination with any given colouring matter." The mordant is first precipitated on to the fibre and combines with the colouring matter in the subsequent dye bath. But, whether the action is chemical or merely physical, the fact remains that all adjective dyes need this preparation of the fibre before they will fix themselves on it. The use of a mordant, though not a necessity, is sometimes an advantage when using substantive dyes. In early days the leaves and roots of certain plants were used. This is the case even now in India and other parts where primitive dyeing methods are still carried on. Alum has been known for centuries in Europe. Iron and tin filings have also been used. Alum and copperas have been known in the Highlands for long ages. Stale urine is also much used in Scotland and Ireland, but perhaps more as a clearing agent than as an actual mordant. Silk and wool require very much the same preparation except that in the case of silk high temperatures should be avoided. Wool is generally boiled in a weak solution of whatever mordant is used. With silk, as a rule, it is better to use a cold solution, or a solution at a temperature below boiling point. Cotton and linen are more difficult to dye than wool or silk. Their fibre is not so porous and will not hold the dye stuff without a more complicated preparation. The usual method of preparing linen or cotton is to boil it first with some astringent. The use of astringents in dyeing depends upon the tannic acid they contain. In combination with ordinary mordants, tannic acid aids the attraction of the colouring matter to the fibre and adds brilliancy to the colours. The astringents mostly used are tannic acid, gall nuts, sumach and myrobalams. Cotton has a natural attraction for tannic acid, so that when once steeped in its solution it is not easily removed by washing. ALUM. (_Aluminium sulphate._)--This is the most generally used of all the mordants, and has been known as such from early times in many parts of the world. For most colours a certain proportion of cream of tartar should be added to the alum bath as it helps to brighten the ultimate colour. The usual amount of alum used is a quarter of a pound to every pound of wool. As a rule, less mordant is needed for light colours than for dark. An excess of alum is apt to make the wool sticky. "For dyeing worsted and stuffs yellow, you make use of the usual preparation, viz., of tartar and alum. You allow four ounces of alum to every pound of wool, or twenty-five pounds to every hundred. With regard to the tartar, one ounce to every pound is sufficient for yellow, though it requires two for red."--Hellot. The usual length of time for boiling with alum is from ½ an hour to 1 hour; but some dyers give as much as 2½ hours. _Various examples of mordanting with alum._-- _For silk._ Wet out the silk thoroughly with water and wring out. Then work it about a little in a strong solution of alum, previously dissolved in hot water, and steep for several hours (or over night). Then wash well. It should not be allowed to dry before dyeing. "Silks are always alumed in the cold, because when they are alumed in a hot bath, they are apt to lose a portion of their lustre." _Berthollet._ _For wool._ ¼ lb. of Alum and 1 oz. Cream of tartar for every pound of wool. This is dissolved and when the water is warm the wool is entered. Raise to boiling point and boil for one hour. The bath is then taken off the fire and allowed to cool over night. The wool is then wrung out (not washed) and put away in a linen bag in cool place for four or five days, when it is ready for dyeing. _For cotton and linen._ After boiling in water (some use a sour water, some an alkaline ley) the cotton is put into the alum bath, ¼ lb. of Alum to 1 lb. of cotton. The alum is dissolved in hot water with soda in the proportion of 1 part soda to 16 of alum. (Some add a small quantity of tartar and arsenic). The cotton is well worked in this solution and left 24 hours. It is then washed, and afterwards galled. _For linen._ ¼ lb. alum for every pound of linen. Boil for 2½ hours and immediately put into the dye bath. _For wool._ 6 to 8 per cent. of alum and 5 to 7 per cent. of tartar of the weight of wool. IRON. (_Ferrous Sulphate_, _copperas_, _green vitriol_) Iron is one of the oldest mordants known and is largely used in wool and cotton dyeing. It is almost as important as alum. With wool it should be used in combination with cream of tartar. The temperature of the mordanting bath must be raised very gradually to boiling point or the wool will dye unevenly. A general method of dealing with copperas is to boil the wool first in a decoction of the colouring matter and then add the mordant to the same bath in a proportion of 5 to 8 per cent. of the weight of wool: and continue boiling for half an hour or so longer. With some dyes a separate bath is needed, such as with Camwood or Catechu. If used for cotton, the cotton is first dyed in a boiling decoction of the dye stuff and then passed through a cold solution of ferrous sulphate. Probably the commonest way of applying copperas in cotton dyeing is to prepare the cotton with tannin, pass through clear lime water and then through a copperas solution. Great care is needed in the using of copperas, as, unless it is thoroughly dissolved and mixed with the water before the wool is entered, it is apt to stain the wool. It also hardens wool if used in excess, or if boiled too long. Copperas is mostly used for the fixing of wool colours (Fustic etc.) to produce brown shades by the "stuffing and saddening" method (see page 14), the wool being boiled first in a decoction of the dye for about an hour, and then for ½ an hour with the addition of 5 to 8 per cent. of copperas. If used for darkening colours, copperas is added to the bath, after the dyeing, and the boiling continued for 15 to 20 minutes. _Examples of various proportions for Mordanting._-- 8 per cent. of copperas and 20 per cent. of cream of tartar is a mordant used for some colours. 4 per cent. copperas, 10 per cent. cream of tartar gives good olive colours with weld. 8 per cent. copperas without tartar with single bath method, for dark olive brown with old fustic. 2 oz. copperas and 2 oz. cream of tartar to 2½ lbs. wool. 2 oz. copperas, 1½ oz. oxalic acid to 2½ lbs. wool. TIN.--(_Stannous chloride_, _tin crystals_, _tin salts_, _muriate of tin_.) Tin is not so useful as a mordant in itself, but as a modifying agent with other mordants. It must be always used with great care, as it tends to harden the wool, making it harsh and brittle. Its general effect is to give brighter, clearer and faster colours than the other mordants. When used as a mordant before dyeing, the wool is entered into the cold mordanting bath, containing 4 per cent. of stannous chloride and 2 per cent. oxalic acid: the temperature is gradually raised to boiling, and kept at this temperature for 1 hour. It is sometimes added to the dye bath towards the end of dyeing, to intensify and brighten the colour. It is also used with cochineal for scarlet on wool, in the proportion of 6 per cent. of stannous chloride and 4 per cent. of cream of tartar. Boil for 1 to 1½ hours. Then wash well. The washing after mordanting is not always essential. Also 6 to 8 per cent. of oxalic acid and 6 per cent. of stannous chloride, for cochineal on wool. This mordant produces bright fast yellows from old fustic, by boiling the wool from 1 to 1¼ hours, with 8 per cent. of stannous chloride and 8 per cent. of cream of tartar. One recipe gives 2 oz. tin and 4¼ oz. cream of tartar to 2½ lbs. wool in 10 gallons of water. It is not a suitable mordant alone for cotton, but can be used to brighten the colour in combination with other mordants. "The nitro-muriate of tin (dyer's spirit) although it produces good yellows with quercitron bark, produces them in a much weaker degree than the murio-sulphate of that metal, which is really the cheapest and most efficacious of all the solutions or preparations of tin for dyeing quercitron as well as the cochineal colours."-- _Bancroft._ CHROME. (_Potassium dichromate_, _Bichromate of Potash._) Chrome is a modern mordant, unknown to the dyer of 50 years ago. It is excellent for wool and is easy to use and very effective in its action. Its great advantage is that it leaves the wool soft to the touch, whereas the other mordants are apt to harden the wool. In commercial dyeing it is now almost exclusively used, as it has proved itself the most generally convenient. By some it is said not to be so fast to light as the other mordants, but it produces brighter colours. The wool should be boiled for one to one & a half hours with bichromate of potash in the proportion of 2 to 4 per cent. of the wool. It is then washed well and immediately dyed. Wool mordanted with chrome should not be exposed to light, but should be kept well covered with the liquid while being mordanted, else it is liable to dye unevenly. An excess of chrome impairs the colour. 3 per cent. of chrome is a safe quantity to use for ordinary dyeing. One recipe gives 1½ oz. of chrome to 2½ lbs. of wool. It should be dissolved in the bath while the water is heating. The wool is entered and the bath gradually raised to the boiling point, and boiled for three quarters of an hour. In the dyeing of cotton, it is used for catechu browns and other colours. The cotton is soaked in a decoction of catechu, and afterwards passed through a boiling solution of chrome, or it is worked for half an hour in a bath of chrome at 60°C., and then washed. It is usual to wash wool or cotton after mordanting with chrome, but some dyers do not think it necessary. COPPER. (_Copper Sulphate_, _Verdigris_, _blue vitriol_, _blue-stone_.) Copper is rarely used as a mordant. It is usually applied as a saddening agent, that is, the wool is dyed first, and the mordant applied afterwards to fix the colour. With cream of tartar it is used sometimes as an ordinary mordant before dyeing, but the colours so produced have no advantage over colours mordanted by easier methods\. EXAMPLES.--6 per cent. of copper is used as a mordant for weld to produce an olive yellow. 4 to 5 per cent. is used with old fustic for yellow. 10 per cent. of copper gives to wool a reddish purple with cochineal. Mordants should not affect the physical characteristics of the fibres. Sufficient time must be allowed for the mordant to penetrate the fibre thoroughly. If the mordant is only superficial, the dye will be uneven: it will fade and will not be as brilliant as it should be. The brilliancy and fastness of Eastern dyes are probably due to a great extent to the length of time taken over the various processes of dyeing. _The longer time that can be given to each process, the more satisfactory will be the result._ Different mordants give different colours with the same dye stuff. For example:--Cochineal, if mordanted with alum, will give a crimson colour; with iron, purple; with tin, scarlet; and with chrome or copper, purple. Logwood, also, if mordanted with alum, gives a mauve colour; if mordanted with chrome, it gives a blue. Fustic, weld, and most of the yellow dyes, give a greeny yellow with alum, but an old gold colour with chrome; and fawns of various shades with other mordants. TANNIN.--(_Tannic Acid_.)--Tannins are used in the dyeing of cotton and linen. Cotton and linen possess the remarkable power of attracting tannins from their aqueous solution, and when these substances are prepared with tannins, they are able to retain dyes permanently. Cotton saturated with tannin, attracts the dye stuff more rapidly, and holds it. Tannic acid is the best tannin for mordanting cotton and linen, as it is the purest and is free from any other colouring matter. It is, therefore, used for pale and bright shades. But for dark shades, substances containing tannic acid are used, such as sumach, myrobalans, valonia, divi-divi, oak galls, chestnut (8 to 10 per cent. of tannin), catechu. Cotton and linen are prepared with tannin after they have been through the required cleansing, and if necessary, bleaching operations. A bath is prepared with 2 to 5 per cent. of tannic acid of the weight of the cotton, and a sufficient quantity of water. For dark shades, 5 to 10 per cent. should be used. The bath is used either hot or cold. It should not be above 60°C. The cotton is worked in this for some time, and then left to soak for 3 to 12 hours, while the bath cools. It is then wrung out and slightly washed. The following gives the relative proportions of the various substances containing tannin:--1 lb. tannin _equals_ 4 lbs. sumach, 18 lbs. myrobalans, 14 lbs. divi-divi, 11 lbs. oak galls. A few examples taken from various recipes of cotton dyeing:-- For 10 lbs. cotton use 12 oz. tannin. For 50 lbs. cotton use 10 lbs. sumach. For 40 lbs. cotton use 10 lbs. sumach. For 20 lbs. cotton use 2 lbs. yellow catechu or black catechu. For 20 lbs cotton spend 3 lbs. of catechu with 3 oz. of blue vitriol. Some recipes soak the cotton for 24 hours, others for 48 hours. CHAPTER IV. BRITISH DYE PLANTS The introduction of foreign dye woods and other dyes during the 17th and 18th centuries rapidly displaced the native dye plants, except in certain out of the way places such as the Highlands and parts of Ireland. Some of these British dye plants had been used from early historical times for dyeing. Some few are still in use in commercial dye work (pear, sloe, and a few others); but their disuse was practically completed during the 19th century when the chemical dyes ousted them from the market. The majority of these plants are not very important as dyes, and could not probably now be collected in sufficient quantities. Some few however are important, such as woad, weld, heather, walnut, alder, oak, some lichens; and many of the less important ones would produce valuable colours if experiments were made with the right mordants. Those which have been in use in the Highlands are most of them good dyes. Among these are Ladies Bedstraw, whortleberry, yellow iris, bracken, bramble, meadow sweet, alder, heather and many others. The yellow dyes are the most plentiful, and many of these are good fast colours. Practically no good red, in quantity, is obtainable. Madder is the only reliable red dye among plants, and that is no longer indigenous in England. Most of the dye plants require a preparation of the material to be dyed, with alum, or some other mordant, but a few, such as Barberry, and some of the lichens, are substantive dyes, and require no mordant. PLANTS WHICH DYE RED.-- Potentil. _Potentilla Tormentilla._ Roots. Wild Madder. _Rubia peregrina._ Lady's Bedstraw. _Galium verum._ Roots. Gromwell. _Lithospermum arvense._ Marsh Potentil. _Potentilla Comarum._ Roots. Birch. _Betula alba._ Fresh inner bark. Bed-straw. _Galium boreale._ Roots. Common Sorrel. _Rumex acetosa._ Roots. Evergreen Alkanet. _Anchusa sempervirens._ With chloride of tin. Dyer's Woodruff. _Asperula tinctoria._ Roots. PLANTS WHICH DYE BLUE.-- Woad. _Isatis Tinctoria._ Whortleberry or blaeberry. _Vaccinium Myrtillus._ Berries. Elder. _Sambucus nigra._ Berries. Privet. _Ligustrum vulgare._ Berries, with alum and salt. [2]Sloe. _Prunus communis._ Fruit. Red bearberry. _Arctostaphylos Uva-Ursi._ Dogs Mercury. _Mercurialis perennis._ Yellow Iris. _Iris Pseudacorus._ Root. Devil's Bit. _Scabiosa succisa._ Leaves prepared like woad. PLANTS WHICH DYE YELLOW.-- Weld. _Reseda luteola._ Meadow Rue. _Thalictrum flavum._ Roots. Marsh Marigold. _Caltha palustris._ Flowers. S. John's Wort. _Hypericum perforatum._ Heath. _Erica vulgaris._ With Alum. Spindle tree. _Euonymus Europæus._ Buckthorn. _Rhamnus frangula_ and _R. cathartica._ Berries and Bark. [3]Dyer's Greenwood. _Genista tinctoria._ Young shoots and leaves. Kidney Vetch. _Anthyllis Vulnararia._ Marsh Potentil. _Potentilla Comarum._ Ling. _Calluna vulgaris._ Yellow Centaury. _Chlora perfoliata._ Hornbeam. _Carpinus Betulus._ Bark. Hedge stachys. _Stachys palustris._ Polygonum Persecaria. Polygonum Hydropiper. Hop. _Humulus lupulus._ Stinking Willy, or Ragweed. _Senecio Jacobæa._ Yellow Camomile. _Anthemis tinctoria._ Common dock. _Rumex obtusifolius._ Root. [4]Sawwort. _Serratula tinctoria._ Gorse. _Ulex Europæus._ Bark, flowers and young shoots. Broom. _Sarothamnus scoparius._ Bracken. _Pteris aquilina._ Roots. Also young tops. Way-faring tree. _Viburnum lantana._ Leaves, with alum. Bramble. _Rubus fructicosus._ Nettle. _Urtica._ With alum. Bog Myrtle or Sweet Gale. _Myrica Gale._ Teasel. _Dipsacus Sylvestris._ Sundew. _Drosera._ Barberry. _Berberis vulgaris._ Stem and root. Bog asphodel. _Narthecium ossifragum._ Agrimony. _Agrimonia Eupatoria._ Yellow corydal. _Corydalis lutea._ Privet. _Ligustrum vulgare._ Leaves. Crab Apple. _Pyrus Malus._ Fresh inner bark. Ash. _Fraxinus excelsior._ Fresh inner bark. Pear. Leaves. Poplar. Leaves. Plum. Leaves. Birch. Leaves. [5]Willow. Leaves. PLANTS WHICH DYE GREEN.-- Privet. _Ligustrum vulgare._ Berries and leaves, with alum. Flowering reed. _Phragmites communis._ Flowering tops, with copperas. Elder. _Sambucus nigra._ Leaves with alum. Nettle. _Urtica dioica_ and _U. Urens_. Lily of the valley. _Convalaria majalis._ Leaves. Larch. Bark, with alum. PLANTS WHICH DYE BROWN.-- Whortleberry. _Vaccinium Myrtillus._ Young shoots, with nut galls. Larch. Pine needles, collected in Autumn. Walnut. Root and green husks of nut. Water Lily. _Nymphæa alba._ Root. Alder. _Alnus glutinosa._ Bark. Birch. _Betula alba._ Bark. Oak. _Quercus Rohur._ Bark. Red currants, with alum. Hop. _Humulus lupulus._ Stalks give a brownish red colour. PLANTS WHICH DYE PURPLE.-- Whortleberry or blaeberry. _Vaccinium myrtillus._ Berries. "It contains a blue or purple dye which will dye wool and silk without mordant." Deadly nightshade. _Atropa Belladonna._ Sundew. _Drosera._ Bryony. _Bryonia dioica._ Berries. Danewort. _Sambucus Ebulus._ Berries. Elder. _Sambucus nigra._ Berries, with alum, a violet; with alum and salt, a lilac colour. Dandelion. _Taraxacum Dens-leonis._ Roots. Dyes a magenta colour. Damson. Fruit, with alum. PLANTS WHICH DYE BLACK.-- Alder. _Alnus glutinosa._ Bark with copperas. Blackberry. _Rubus fruticosus._ Young shoots, with salts of iron. Dock. _Rumex._ Root. Iris. _Iris Pseudacorus._ Root. Meadowsweet. _Spirea Ulmaria._ Oak. Bark and acorns. Elder. Bark, with copperas. FOOTNOTES: [2] "On boiling sloes, their juice becomes red, and the red dye which it imparts to linen changes, when washed with soap, into a bluish colour, which is permanent." [3] "For giving very inferior yellow upon coarser woollens, the dyer's broom, _genista tinctoria_, is sometimes employed, with the common preparation of alum and tartar." [4] Sawwort which grows abundantly in meadows affords a very fine pure yellow with alum mordant, which greatly resembles weld yellow. It is extremely permanent. [5] "The leaves of the sweet willow, _salix pentandra_, gathered at the end of August and dried in the shade, afford, if boiled with about one thirtieth potash, a fine yellow colour to wool, silk and thread, with alum basis. All the 5 species of Erica or heath growing on this island are capable of affording yellows much like those from the dyer's broom; also the bark and shoots of the Lombardy poplar, _populus pyramidalis_. The three leaved hellebore, _helleborus trifolius_, for dyeing wool yellow is used in Canada. The seeds of the purple trefoil, lucerne, and fenugreek, the flowers of the French marigold, the chamomile, _antemis tinctoria_, the ash, _fraxinus excelsior_, fumitory, _fumaria officinalis_, dye wool yellow." "The American golden rod, _solidago canadensis_, affords a very beautiful yellow to wool, silk and cotton upon an aluminous basis."--Bancroft. CHAPTER V. THE LICHEN DYES Some of the most useful dyes and the least known are to be found among the Lichens. They seem to have been used among peasant dyers from remote ages, but apparently none of the great French dyers used them, nor are they mentioned in any of the old books on dyeing. The only Lichen dyes that are known generally among dyers are Orchil and Cudbear, and these are preparations of lichens, not the lichens themselves. They are still used in some quantity and are prepared rather elaborately. But a great many of the ordinary Lichens yield very good and permanent dyes. The Parmelia saxatilis and P. omphaloides, are largely used in the Highlands & West Ireland, for dyeing brown of all shades. No mordant is needed, and the colours produced are the fastest known. "Crottle," is the general name for Lichens, in Scotland. They are gathered off the rocks in July and August, dried in the sun, and used to dye wool, without any preparation. The crottle is put into the dye bath with a sufficient quantity of water, boiled up and allowed to cool and then boiled up with the wool until the shade required is got. This may take from one to three or four hours, as the dye is not rapidly taken up by the wool. Other dyers use it in the following way:--A layer of crottle, a layer of wool, and so on until the bath is full; fill up with cold water and bring to the boil, and boil till the colour is deep enough. Some of the finest browns are got in this way. The wool does not seem to be affected by keeping it in the dye a long time. A small quantity of acetic acid put in with the Lichen is said to assist in exhausting the colour. The grey Lichen _Ramalina scopulorum_, dyes a fine shade of yellow brown. It grows very plentifully on old stone walls, especially by the sea, and in damp woods, on trees, and on old rotten wood. Boil the Lichen up in sufficient water one day, and the next day put in the wool, and boil up again till the right colour is got. If the wool is left in the dye for a day or more after boiling, it absorbs more colour, and it does not hurt the wool, but leaves it soft and silky to the touch, though apt to be uneven in colour. Some mordant the wool first with alum, but it does not seem to need it. The best known of the dye Lichens are Parmelia saxatilis, and Parmelia omphalodes, which are still largely used in Scotland and Ireland for dyeing wool for tweeds. The well known Harris tweed smell is partly due to the use of this dye. Other Lichens also known for their dyeing properties are:--Parmelia caperata or Stone Crottle which contains a yellow dye, P. ceratophylla, or Dark Crottle, and P. parietina, the common wall lichen, which gives a colour similar to the colour of the lichen itself, yellowish brown. In _Bancroft's_ "Philosophy of Permanent Colours" is to be found the following--"Besides the lichens, whose colour depends upon a combination with the ammonia, there are some which afford substantive colours, less beautiful indeed, but more durable, by merely boiling with water. One of these is the muscus pulmonarius of Caspar Bauhine, or the lichenoides pulmonium reticulatum vulgare marginibus peltiferus of Dillenius, called Rags and Stone Rags, in the northern parts of England, which, without any mordant, dyes a very durable dark brown colour upon white wool or cloth, and a fine lasting black upon wool or cloth which has previously received a dark blue from Indigo." The following occurs in an old Scottish history.--"There is one excresence gotton off the craigs which they call cork-lit, and make use thereof for litting, or dyeing a kind of purple colour." Another lichen, taken from trees in Scotland, was used for producing an orange tint, called Philamort. The tree lichen was called wood-raw, or rags, to distinguish it from stone lichen, or stone-raw. A deep red colour was got from the dull grey friable lichen, common on old stone walls, which was scraped off, with a metal scraper. The bright yellow lichen, growing on rocks and walls, and old roofs, dyes a fine plum colour, if the wool is mordanted first with Bichromate of Potash. There is a difficulty, however, in getting enough of this lichen to make the dyeing with it practicable. The colour of the plant is no indication of the colorific power. That is often greatly modified by the conditions of its growth,--such as climate, elevation above the sea, nearness or distance from the sea, age, season when gathered, habitat. The best season for gathering most lichens, is late summer and autumn. In Sweden, Scotland and other countries, the peasantry use a lichen, called _Lecanora tartarea_, to furnish a red or crimson dye. In Shetland, the _Parmelia saxatilis_ (Scrottyie) is used to dye brown. It is found in abundance on argillaceous rocks. It is considered best if gathered late in the year, and is generally collected in August. Immediately after being collected, an iron vessel is filled with it, and stale urine then poured over it, till the vessel is full. This is slowly boiled until the plant begins to assume a mucillaginous appearance, which generally takes place in about 2 hours. When taken off the fire, it has the consistence of a thin jelly, but it speedily hardens until it is nearly as thick as porridge, and its colour becomes a dark rusty grey. It is then folded in the cloth, layer by layer of Scrottyie and cloth alternately, and all is boiled for about 20 minutes, in soft water, in which a little alum has been dissolved. It is then taken off the fire and the cloth washed in cold water, when the process of dyeing is complete. The Scrottyie, taken from between the folds of the cloth, is used several times for dyeing, on being treated again in the same manner. The plant used in Shetland for the red dye is the _Lecanora tartarea_. It is found abundantly on almost all rocks and also grows on dry moors, along with _Cladonia sangiferina_. (If a particle of the latter is allowed to be intermixed with the dye, it is supposed to be spoiled.) The lichen, and the dye made from it, are called Korkalett. This lichen is collected in May and June, and steeped in stale urine for about 3 weeks, being kept at a moderate heat all the time. The substance having then a thick and strong texture, like bread, and being of a bluish black colour, is taken out and made into small cakes of about ¾ lb. in weight, which are wrapped in dock leaves and hung up to dry in peat smoke. When dry it may be preserved fit for use for many years; when wanted for dyeing it is partially dissolved in warm water till of the consistence of Scrottyie, the dyeing proceeds in the same manner; 5 lbs. of korkalett being considered sufficient for about 4 Scotch ells of cloth. The colour produced is a light red. It is much used in the dyeing of yarn as well as cloth. The yarn is simply boiled in it without folding as in the case of cloth.[6] Linnæus mentions that a beautiful red colour may be prepared from Lichen pustulatus, _Gyrophora pustulata_. _G. cylindrica_ is used by Icelanders for dyeing woollen stuffs a brownish green colour. In Sweden and Norway, _Evernia vulpina_ is used for dyeing woollen stuffs yellow. Iceland moss, _Cetraria Islandica_, is used in Iceland for dyeing brown. _Usnea barbata_ is collected from trees in Pennsylvania & used for an orange colour for yarn. _Lecanora tartarea_ (corcur of the Scottish Highlanders) dyes a claret. It is usually prepared by pounding the lichen and mixing it with stale chamberley, to which a little salt or kelp is added; this mixture is kept for several weeks, and frequently stirred; being then brought to the consistence of coarse paste, it is made up into balls, with a little lime or burnt shells, and is kept ready for use. When used, it is coarsely powdered and a small portion of alum is generally added. A general method for using lichens is suggested by Dr. Westring of Sweden, in his "Experiments on Lichens for Dyeing Wools and Silks." He says: "The Lichens should be gathered after some days of rain, they can then be more easily detached from the rocks. They should be well washed, dried and reduced to a fine powder: 25 parts pure river water are added to 1 of powdered lichen, and 1 part of fresh quick lime to 10 parts powdered lichen. To 10 lbs. lichen ½ lb. sal ammoniac is sufficient when lime and sal ammoniac are used together. The vessel containing them should be kept covered for the first 2 or 3 days. Sometimes the addition of a little common salt or salt-petre will give greater lustre to the colours."[7] This method can be followed by anyone wishing to experiment with Lichens. Dr. Westring did not use a mordant as a rule. Where the same species of Lichen grows on both rocks and trees, the specimens taken from rocks give the better colours. ORCHIL OR ARCHIL AND CUDBEAR are substantive or non mordant dyes, obtained from Lichens of various species of Roccella growing on rocks in the Canary Islands and other tropical and sub-tropical countries. They used to be made in certain parts of Great Britain from various lichens, but the manufacture of these has almost entirely disappeared. They have been known from early times as dyes. They give beautiful purples and reds, but the colour is not very fast. The dye is produced by the action of ammonia and oxygen upon the crushed Lichens or weeds as they are called. The early way of producing the colour was by treating the Lichen with stale urine and slaked lime, and this method was followed in Scotland. Orchil is applied to wool by the simple process of boiling it in a neutral or slightly acid solution of the colouring matter. 3% Sulphuric acid is a useful combination. Sometimes alum and tartar are used. It dyes slowly and evenly. It is used as a bottom for Indigo on wool and also for compound shades on wool and silk. For cotton and linen dyeing it is not used. It is rarely used by itself as the colour is fugitive, but by using a mordant of tin, the colour is made much more permanent. "Archil is in general a very useful ingredient in dyeing; but as it is rich in colour, and communicates an alluring bloom, dyers are often tempted to abuse it, and to exceed the proportions that can add to the beauty, without, at the same time, injuring in a dangerous manner the permanence of the colours. Nevertheless, the colour obtained when solution of tin is employed, is less fugitive than without this addition."[8] Many of the British lichens produce colours by the same treatment as is used for producing Orchil. Large quantities were manufactured in Scotland from lichens gathered in the Shetland Islands and Western Highlands. This was called Cudbear. The species used by the Scottish Cudbear makers were generally _Lecanora tartarea_ and _Urceolaria calcarea_; but the following lichens also give the purple colour on treatment with ammonia.--_Evernia prunastri_, _Lecanora pallescens_, _Umbilicaria vellea_, _U. pustulata_, _Parmelia perlata_; whilst several others give colours of similar character, but of little commercial value. The manufacture of Archil and Cudbear from the various lichens is simple in principle. In all cases the plant is reduced to a pulp with water and ammonia, and the mass kept at a moderate heat and allowed to ferment, the process taking two or three weeks to complete. The ammonia used to be added in the form of stale urine, and additions of slaked lime were made from time to time.[9] The general mode of treatment for the development from the dye lichens of orchil and cudbear consists of the following steps:-- 1.--Careful washing, drying and cleaning, to separate earthy and other impurities. 2.--Pulverisation into a coarse or fine pulp with water. 3.--Regulated addition of ammonia of a certain strength and derived from various sources (putrid urine, gas liquor, etc.) 4.--Frequent stirring of the fermenting mass so as to ensure full exposure of every part thereof to the action of atmospheric oxygen. 5.--Addition of alkalis in some cases (e.g. potash or soda) to heighten or modify the colour; and of chalk, gypsum and other substances, to impart consistence. Various accessories are employed, e.g. the application of continued, moderate and carefully regulated heat during the process of fermentation.[10] RECIPES FOR DYEING WITH LICHENS. _To dye Brown with Crotal._ For 6¼ lbs. (100 oz.) of wool. Dye baths may be used of varying strengths of from 10 to 50 oz. of Crotal. Raise the bath to the boil, and boil for an hour. A light tan shade is got by first dipping the wool in a strong solution of Crotal, a darker shade by boiling for half-an-hour, and a dark brown by boiling for two hours or so. It is better, however, to get the shade by altering the quantity of Crotal used. The addition of sufficient oil of vitriol to make the bath slightly acid will be an improvement. (A very small quantity should be used). _To Dye Red with Crotal._-- Gather the lichen off the rocks--it is best in winter. Put layers of lichen and wool alternately in a pot, fill up with water and boil until you get the desired tint. Too much crotal will make the wool a dark red brown, but a very pretty terra cotta red can be got. No mordant is required. _To Dye Pink from a bright yellow Lichen._ (_Parmelia parietina_). Mordant the wool with 3% of Bichromate of Potash, then boil with the lichen for 1 hour or more. _To Dye Brown from Crotal._ Boil the wool with an equal quantity of lichen for 1 or 1½ hours. No mordant is required. _To dye red purple from Cudbear & Logwood._ Dye with equal quantities of Cudbear and Logwood, the wool having been mordanted with chrome. A lighter colour is got by dyeing with 8 lbs. cudbear and ½ lb. logwood (for 30 lbs. wool). _To Dye Yellow on Linen with the Lichen Peltigera canina_ (a large flat lichen growing on rocks in woods). Mordant with alum, (¼ lb. to a lb. of linen) boil for 2 hours. Then boil up with sufficient quantity of the lichen till the desired colour is got. LIST OF LICHENS USED BY THE PEASANTRY OF DIFFERENT COUNTRIES FOR WOOL DYEING.[11] SHADES OF RED, PURPLE AND ORANGE. _Roccella tinctoria._ Orseille. Grows in the South of France, on rocks by the sea. _Lecanora tartarea._ Crotal, Crottle, Corkur, Corcir, Korkir. Found in the Scotch Highlands and Islands, growing on rocks; used for the manufacture of Cudbear in Leith & Glasgow. _L. parella._ Light Crottle, Crabs Eye Lichen. Found in Scotland, France, and England, on rocks and trees, formerly celebrated in the South of France in the making of the dye called Orseille d'Auvergne. _L. hæmatomma._--Bloody spotted lecanora, Black lecanora. Found in Scotland on rocks and trees. _Umbilicaria pustulata._--Blistered umbilicaria. Found on rocks in Norway and Sweden. _Isidium corallinum._ White crottle. Found on rocks in Scotland. _I. Westringii._ Westring's Isidium. Norway and Sweden. _Urceolaria calcarea._ Corkir, Limestone Urceolaria. Found in Scotland, Western Islands, Shetland and Wales, growing on limestone rocks. _U. Scruposa._ Rock Urceolaria. Grows on rocks in hilly districts in England. _U. cinerea._ Greyish Urceolaria. In England, on rocks. _Parmelia saxatilis._ Crottle, stane-raw, Staney-raw, (Scotland). Scrottyie, (Shetland). Sten-laf, Sten-mossa, (Norway and Sweden). Found on rocks and stones in Scotland, Shetland, and Scandinavia. In winter the Swedish peasantry wear home made garments dyed purple by this lichen. By the Shetlanders it is usually collected in August, when it is considered richest in colouring matter. _P. omphalodes._ Black Crottle, Cork, Corker, Crostil or Crostal, (Scotch Highlands). Arcel, (Ireland). Kenkerig, (Wales). Alaforel-leaf, (Sweden). Found on rocks, especially Alpine, in Scotland, Ireland, Wales and Scandinavia. One of the most extensively used dye-lichens. It yields a dark brown dye readily to boiling water, and it is easily fixed to yarns by simple mordants. It is stated to yield a red, crimson or purple dye. _P. caperata._ Stone crottle, Arcel. Found in North of Ireland and Isle of Man, on trees. Said to dye yarn brown, orange and lemon yellow. _P. conspersa._ Sprinkled parmelia. Found growing on rocks in England. _Evernia prunastri._ Ragged hoary lichen. Stag's horn lichen. Found in Scotland, on trees. _Ramalina scopulorum._ Ivory-like ramalina. Scotland, on maritime rocks. A red dye. _R. farinacea._ Mealy ramalina. On trees in England. _Borrera ashney._ Chutcheleera. India. _Solorina crocea._ Saffron yellow solorina. In Scotland, on mountain summits. The colouring matter is ready formed and abundant in the thallus. _Nephroma parilis._ Chocolate colored nephroma. Scotland, on stones. Said to dye blue. _Sticta pulmonacea._ On trees. _Lecidea sanguinaria._ Red fruited lecidea. In Scotland, on rocks. _Conicularia aculeata._ var. _spadicea_. Brown prickly cornicularia. Canary Islands, Highland Mountains. _Usnea barbata._ Bearded Usnea. Pennsylvania and South America. On old trees. Stated to dye yarn orange. _U. florida._ Flowering Usnea. Pale greenish yellow or reddish brown. _U. plicata._ Plaited usnea. On trees. SHADES OF BROWN _Cetraria Islandica._ Iceland moss. Iceland heaths, and hills. It yields a good brown to boiling water, but this dye appears only to have been made available to the Icelanders. _Parmelia physoides._ Dark crottle, Bjork-laf. Found in Sweden, Scotland & Scandinavia, on rocks and trees. _P. omphalodes._ In Scandinavia and Scotland. Withering asserts that it yields a purple dye paler, but more permanent, than orchil; which is prepared in Iceland by steeping in stale lye, adding a little salt and making it up into balls with lime. _Sticta pulmonacea._ Oak lung, Lungwort, Aikraw, Hazel-raw, Oak rag, Hazel rag, Hazel crottle, Rags. Found on trees in England, Scotland, North of Ireland, Scandinavia. It dyes wool orange and is said to have been used by the Herefordshire peasantry to dye stockings brown. Some species yield beautiful saffron or gamboge coloured dyes, e.g. _S. flava_, _crocata_, _aurata_. _For continuation of list see Appendix._ FOOTNOTES: [6] T. Edmonston. _On the Native Dyes of the Shetland Islands_ 1841. [7] The _Annales de Chimie_. Stockholm Transactions 1792. [8] The Art of Dyeing. _Berthollet._ He gives minute directions for the preparation of Archil. See page 365. [9] Some British Dye Lichens. _Alfred Edge._ [10] From Dr. W. L. Lindsay, On Dyeing Properties of Lichens. [11] From an article by Dr. Lauder Lindsay on the "Dyeing Properties of Lichens," in the _Edinburgh Philosophical Journal._ July to October 1855. CHAPTER VI. [12]BLUE INDIGO, WOAD, LOGWOOD. "Notwithstanding the very great facility of dyeing wool blue, when the blue vat is once prepared, it is far otherwise with regard to the preparation of this vat, which is actually the most difficult operation in the whole art of dyeing."--Hellot. _INDIGO_ Indigo is the blue matter extracted from a plant, _Indigofera tinctoria_ & other species, growing in Asia, South America and Egypt. It reaches the market in a fine powder, which is insoluble in water. There are two ways of dyeing with indigo. It may be dissolved in sulphuric acid or oil of vitriol, thereby making an indigo extract. This process was discovered in 1740. It gives good blue colours, but is not very permanent. Darker colours by this method are more permanent than the paler ones. It does not dye cotton or linen. The other method is by the indigo vat process, which produces fast colours, but is complicated and difficult. In order to colour with indigo, it has to be deprived of its oxygen. The deoxydised indigo is yellow, and in this state penetrates the woollen fibre; the more perfectly the indigo in a vat is deoxydised, the brighter and faster will be the colour. For the dyeing of wool, the vats are usually heated to a temperature of 50°C. Cotton and linen are generally dyed cold. _Hellot_ says "when the vat, of whatsoever kind it be, is once prepared in a proper state, there is no difficulty in dyeing woollens or stuffs, as it is requisite only to soak them in clean warm water, to wring them, and then to immerse them in the vat, for a longer or shorter time, according as you would have the colour more or less deep. The stuff should be from time to time opened, that is to say, taken out and wrung over the vat and exposed to the air for a minute or two, till it becomes blue. For let your vat be what it will, the stuff will be green when taken out and will become blue when exposed to the air. In this manner it is very proper to let the colour change before you immerse your stuffs a second time, as you are thereby better enabled to judge whether they will require only one or several dips."--"The Art of Dyeing Wool," by _Hellot_. The colour of the blue is brightened by passing the wool through boiling water after it comes out of the dye. Indigo is a substantive dye and consequently requires no mordant. [13]1). TO MAKE EXTRACT OF INDIGO.-- Put 2 lbs. of oil of vitriol into a glass bottle or jar, stir into it 8 oz. of powdered indigo, stirring briskly for ½ hour, then cover up and stir 4 or 5 times a day for a few days, then add a little powdered chalk to neutralise the acid. It should be added slowly, little by little, as the chalk makes the acid bubble up. Keep it closely corked. 2). TO MAKE EXTRACT OF INDIGO.-- 4 oz. sulphuric acid, ½ oz. finely ground Indigo. Mix like mustard, and leave to stand over-night. Prepare the wool by mordanting with 5 oz. alum to 1 lb. wool. Boil for ½ hour and dye without drying. 3). TO DYE WOOL WITH INDIGO EXTRACT For 4 to 6 lbs. of wool. Stir 2 to 3 oz. of Indigo extract into the water of the dye bath. The amount is determined by the depth of shade required. When warm, enter the wool, and bring slowly to boiling point (about ½ hour) and continue boiling for another ½ hour. By keeping it below boiling point while dyeing, better colours are got, but it is apt to be uneven. Boiling levels the colour but makes the shade greener. This is corrected by adding to the dye bath a little logwood, 10 to 20 per cent. This should be boiled up separately, strained, and put in the bath before the wool is entered. Too much should be avoided however, as it dims the colour. It can be done in the same bath, but better results are got by separate baths. Instead of logwood a little madder is sometimes used; also Cudbear or Barwood. 4). TO DYE SILK WITH INDIGO EXTRACT. Dye at a temperature of 40 to 50°C. in a bath with a little sulphuric acid and the amount of indigo as is needed for the colour. Another method is to mordant the silk first with alum by steeping it for 12 hours in a solution of 25 per cent. and then, without washing, to dye with the Indigo Extract and about 10% of alum added to the dye bath. By this means compound colours can be made by the addition of cochineal, for purple, or old Fustic, Logwood, etc., for greys, browns and other colours. 5). SAXON BLUE.-- Put into a glazed earthen pot 4 lbs. of good oil of vitriol with 12 oz. of choice Indigo, stir this mixture very hastily and frequently in order to excite a fermentation. It is customary with some Dyers to put into this composition a little antimony or salt-petre, tartar, chalk, alum and other things, but I find it sufficient to mix the oil and Indigo alone, and the colours will be finer, for those neutral salts destroy the acid of the vitriol and sully the colour. In 24 hours it is fit for use. Then a copper of a good size is to be filled with fair water (into which one peck of bran is put in a bag) and made pretty warm, the bran after yielding its flower must be taken out, and the Chymie, (Indigo Extract) mixed well with water in a Piggin, (a small pot) is put in according to the shade required, having first put in a hand-ful of powdered tartar; the cloth is to be well wet and worked very quick over the winch (stick on which it is hung) for half an hour. The liquor must not be made hotter than for madder red (just under boiling point). The hot acid of the vitriol would cause the blue to incline to green if too much heat was given. (From an old Dye Book). 6). TO MAKE UP A BLUE VAT.-- Take 1 lb. Indigo thoroughly ground, put this into a deep vessel with about 12 gallons of water, add 2 lbs. copperas, and 3 lbs. newly slaked lime, and stir for 15 minutes. Stir again after 2 hours and repeat every 2 hours for 5 or 6 times. Towards the end, the liquor should be a greenish yellow colour, with blackish veins through it, and a rich froth of Indigo on the surface. After standing 8 hours to settle, the vat is fit to use. 7). TURQUOISE FOR WOOL.-- Mordant with alum. For a pale shade use 1 teaspoonful of Indigo Extract (see No. 2) for 1 lb. of wool. Boil ¼ hour. 8). BLUE FOR WOOL. (Highlands). Take a sufficiency of Indigo. (For medium shade about 1 oz. to every pound of wool). Dissolve it in about as much stale urine (about a fortnight old) as will make a bath for the wool. Make it lukewarm. Put in the wool and keep it at the same temperature till the dyeing is done. For a deep navy blue it will take a month, but a pale blue will be done in 3 or 4 days. Every morning and evening the wool must be taken out of the dye bath, wrung out and put back again. The bath must be kept covered and the temperature carefully attended to. Some add a decoction of dock roots the last day, which is said to fix the blue. The wool must then be thoroughly washed. This is a fast dye. 9). INDIGO VAT. (For small dyers). Add to 500 litres of stale urine 3 to 4 kilos of common salt and heat the mixture to 50° to 60°C., for 4 to 5 hours with frequent stirring, then add 1 kilo of madder, 1 kilo of ground Indigo, stir well, and allow to ferment till the Indigo is reduced. 10). SAXON BLUE. (_Berthollet_). Prepare the wool with alum and tartar. A smaller or greater proportion of the Indigo solution is put into the bath, (1 part of Indigo with 8 parts of sulphuric acid, digested for 24 hours), according to the depth of shade wished to be obtained. For deep shades it is advantageous to pour in the solution by portions, lifting out the wool from the bath while it is being added. The cold bath acts as well as the hot. 11). THE COLD INDIGO VAT WITH URINE. Take 4 lbs. of powdered Indigo and put it into a gallon of vinegar, leaving it to digest over a slow fire for 24 hours. At the end of this time the Indigo should be quite dissolved. If not dissolved pound it up with some of the liquor adding a little urine. Put into it ½ lb. madder, mixing it well. Then pour it into a cask containing 60 gallons of urine (fresh or stale). Mix and stir the whole together; this should be done morning and evening for 8 days or until the surface becomes green when stirred, and produces froth. It may be worked immediately without any other preparation than stirring it 3 or 4 hours before-hand. This kind of vat is extremely convenient, because when once prepared it remains so always until it is entirely exhausted. According as you would have your vat larger or smaller you reduce or enlarge the amount of the ingredients used in the same proportion as the original. This vat is sooner prepared in summer than in winter. 12). INDIGO VAT ON A SMALL SCALE FOR WOOLLENS AND COTTONS.-- Have a strong 9 gallon cask, put into it 8 gallons of urine, have a 4 quart pickle jar, into which put 1 lb. ground Indigo and 3 pints of best vinegar; put the jar into a saucepan filled with water, and make it boil well for 2 hours, stirring it all the time. Let it stand in a warm place for 3 days, then pour it into the cask; rake it up twice a day for a month. It must be covered from the air. 13). BLUE VAT FOR WOOLLENS.-- For every 20 gallons of water add 5 oz. ground Indigo, 8 oz. of potash, 3 oz. madder, and 4 oz. bran. Keep the solution at 140°F.; after 24 hours the whole will have begun to ferment, then add 2 oz. madder, stir and allow the whole to settle, after which the vat is ready for use. 14). TO DYE INDIGO BLUE. Urine Vat.-- Prepare vat as follows:--To 3½ gallons of stale urine add 4½ oz. of common salt, and heat the mixture to 125°F. (as hot as the hand can bear). Keep at this heat for 4 to 5 hours, frequently stirring, then add 1¼ oz. thoroughly ground Indigo and 1¼ oz. Madder, stir well and allow to ferment till the Indigo is reduced. This is recognized by the appearance of the vat, which should be of a greenish yellow colour, with streaks of blue. Allow the vat to settle, when you can proceed with dyeing. Process of dyeing the same as in No. 15. 15). TO DYE INDIGO BLUE.--Potash Vat.-- Into a pot 3 parts full of water put 1½ oz. Madder and 1½ oz. bran. Heat to nearly boiling, and keep at this heat for 3 hours. Then add 5 oz. Carbonate of Potash; allow Potash to dissolve and let the liquor cool down till luke-warm. Then add 5 oz. thoroughly ground Indigo, stir well and leave to ferment for two days, occasionally stirring, every 12 hours or so. Wool dyed in this vat must be thoroughly washed after the colour is obtained. _Process of Dyeing._--Into a vat prepared as above, dip the wool. Keep it under the vat liquor, gently moving about a sufficient time to obtain the colour required. A light blue is obtained in a few seconds, darker blues take longer. Take out wool, and thoroughly squeeze out of it all the dye liquor back into the vat. Spread out the wool on the ground, exposed to the air till the full depth of colour is developed. The wool comes out of the vat a greenish shade, but the oxygen in the air darkens it, through oxydation, to indigo blue. The wool should now be washed in cold water with a little acid added to it, and again thoroughly rinsed and dried. 16). BLUE VAT FOR COTTON.-- In a clean tub put 10 pails of water, slacken 1 bushel of lime into it, and cover while slackening; put 6 lbs. ground Indigo in a pot and mix it into a paste with hot water and then put 4 pails of boiling water on to it, stir it, cover it, and leave it. In another pot, put 20 lbs. copperas, pour 4 pails of water on this, stir it and leave it covered. Pour 4 pails of water on the top of the lime that is slackening, rake it up well and put in the melted copperas; rake it well and put in the Indigo; stir well and leave covered for a couple of days, stirring occasionally. Half fill a new vat with the mixture. Rake it well and while you are raking, fill it up with clean water, continue raking for an hour. Cover it over; it can be used the next day. This is a colour that never washes out. 17). GLOUCESTERSHIRE INDIGO VAT. Size 5 feet over the top: 7 feet deep, 6 to 7 feet at the bottom. Take ½ cwt. bran, ¼ peck lime and 40 lbs. indigo. Warm up to 180 to 200°F., rake it 4 times a day. If it ferments too much add more lime: if not enough, more bran. An experienced eye or nose will soon tell when it is ripe or fit to use, which should be in about 3 days. Regulate the strength of the vat from time to time to the colour required. No madder or woad is used when much permanency is wanted. 18). COLD INDIGO VAT FOR DYEING WOOL, SILK, LINEN AND COTTON. 1 part Indigo, 3 parts good quicklime, 3 parts English vitriol, and 1½ parts of orpiment. The Indigo is mixed with water, and the lime added, stirred well, covered up, and left for some hours. The powdered vitriol is then added, and the vat stirred and covered up. After some hours the orpiment powder is thrown in and the mixture is left for some hours. It is then stirred well and allowed to rest till the liquid at the top becomes clear. It is then fit for dyeing. _WOAD_ Woad is derived from a plant, _Isatis tinctoria_, growing in the North of France and in England. It was the only blue dye in the West before Indigo was introduced from India. Since then woad has been little used except as a fermenting agent for the indigo vat. It dyes woollen cloth a greenish colour which changes to a deep blue in the air. It is said to be inferior in colour to indigo but the colour is much more permanent. The leaves when cut are reduced to a paste, kept in heaps for about fifteen days to ferment, and then formed into balls which are dried in the sun; these have a rather agreeable smell and are of a violet colour. These balls are subjected to a further fermentation of 9 weeks before being used by the dyer. When woad is now used it is always in combination with Indigo, to improve the colour. Even by itself, however, it yields a good and very permanent blue. It is not now known how the ancients prepared the blue dye, but it has been stated (Dr. Plowright) that woad leaves when covered with boiling water, weighted down for half-an-hour, the water then poured off, treated with caustic potash and subsequently with hydrochloric acid, yield a good Indigo blue. If the time of infusion be increased, greens and browns are obtained. It is supposed that woad was "vitrum," the dye with which Cæsar said almost all the Britons stained their bodies. It is said to grow near Tewkesbury, also Banbury. It was cultivated till quite lately in Lincolnshire. There were four farms in 1896; one at Parson Drove, near Wisbech, two farms at Holbeach, and one near Boston. Indigo has quite superseded it in commerce.[14] "It is like the Indigo plant, but less delicate and rich. It is put in vats with Indigo and madder to dye a never-fading dark blue on wool, and was called woad-vats before Indigo was known." (Thomas Love). And again "Woad, or what is much stronger, pastel, always dyed the blue woollens of Europe until Indigo was brought over here." Bancroft says "Woad alone dyes a blue colour very durable, but less vivid and beautiful than that of Indigo." _LOGWOOD_ (Bois de Campêche, Campeachy Wood) Logwood is a dye wood from Central America, used for producing blues and purples on wool, black on cotton and wool, and black and violet on silk. It is called by the old dyers, one of the Lesser Dyes, because the colour loses all its brightness when exposed to the air. But with proper mordants and with careful dyeing this dye can produce fast and good colours. Queen Elizabeth's government issued an enactment entirely forbidding the use of logwood. The act is entitled "An Act for the abolishing of certeine deceitful stuffe used in the dyeing of clothes," and it goes on to state that "Whereas there hath been brought from beyond the seas a certeine kind of stuff called logwood, alias blockwood, wherewith divers dyers," etc., and "Whereas the clothes therewith dyed, are not only solde and uttered to the great deceit of the Queene's loving subjects, but beyond the seas, to the great discredit and sclaunder of the dyers of this realme. For reformation whereof, be it enacted by the Queene our Soveraygne Ladie, that all such logwood, in whose handes soever founde, shall be openly burned by authoritie of the maior." The person so offending was liable to imprisonment and the pillory. This is quoted from "The Art of Dyeing," by James Napier, written in 1853. He goes on to say, "Upwards of eighty years elapsed before the real virtues of this dyeing agent were acknowledged; and there is no dyewood we know so universally used, and so universally useful." The principal use for logwood is in making blacks and greys. The logwood chips should be put in a bag and boiled for 20 minutes to ½ hour, just before using. "Logwood is used with galls and copperas for the various shades of greys, inclining to slate, lavender, dove, and lead colour, etc. For this purpose you fill a cauldron full of clean water, putting into it as much nut galls as you think proper. You then add a bag of logwood, and when the whole is boiled, having cooled the liquor, you immerse the stuff, throwing in by degrees some copperas, partly dissolved in water."--Hellot. Hellot is very scornful of logwood, naming it as one of the lesser dyes, and not to be used by good dyers. _RECIPES FOR DYEING WITH LOGWOOD._ 1). BLACK FOR COTTON.-- After washing, work the cotton in a cold infusion of 30% to 40% of Sumach, or its equivalent in other tannin matter[15] (ground gall nuts, myrobalans, etc.) and let steep over-night. Squeeze out and without washing pass through a bath containing a diluted solution of lime water, or soda. Work in a cold solution of copperas for ½ hour, then back into the soda for a ¼ hour at a temperature of 50° to 60°C. Then wash. Dye in a freshly made bath of logwood with a small proportion of old Fustic or Quercitron Bark. The cotton is introduced into the cold dye liquor and the temperature gradually raised to boiling. Boil for ½ an hour. After dyeing, the cotton should be passed through a warm solution of Bichromate of Potash. (5 grains per litre). It is then washed and worked in a warm solution of soap and dried. More Fustic makes a greener black. When catechu is the tanning matter employed, the cotton should be worked in a boiling decoction of it and allowed to steep till cold. 2). GREY DRAB FOR WOOL. (10 lbs.) Dissolve ½ oz. Bichromate of Potash in water, and then boil for ½ hour; lift the wool and add 1 oz. logwood: boil for ½ hour. Lift out, wash and dry. 3). LOGWOOD GREY ON COTTON. The cotton is worked in a weak decoction of logwood at 40° to 50°C., and then in a separate bath containing a weak solution of ferrous sulphate or Bichromate of Potash. Wash. 4). GREEN BLACK FOR WOOL.-- Mordant wool with 3% Bichromate of Potash and 1% Sulphuric acid (or 4% Tartar) for 1 to 1½ hours. Then wash and dye with 35% to 50% of Logwood. This gives a blue black. It is greened by adding 5% old Fustic to the dye bath. The more Fustic the greener the black becomes. If 3% to 4% alum is added to the mordanting bath, a still greener shade is obtained. Sulphuric acid in the mordant produces a dead looking blue black. Tartar yields a bright bluish black. 5). LOGWOOD BLUE FOR WOOL. Mordant the wool for 1 to 1½ hours at 100°C., with 4% alum and 4 to 5% cream of Tartar. Wash well and dye for 1 to 1½ hours at boiling point with 15 to 30% logwood and 2 to 3% chalk. This colour is not very fast, but can be made faster by adding 1 to 3% bichromate of potash and 1% sulphuric acid. The brightest logwood blues are obtained by dyeing just below boiling point. Long boiling dulls the colour. 6). GREEN BLACK FOR WOOL. Mordant with 2% Chrome and 25% sulphuric acid. Boil 1½ hours and leave overnight. Dye with 40% logwood and 10% Fustic. Boil 1 hour. 7). LOGWOOD BLUE FOR WOOL. Chrome 1%, Alum 3%, Tartar 1½%. Boil 1½ hours and leave over-night. Dye with logwood 20% and Cudbear 1%. Boil one hour, then throw in 20 quarts of single muriate of tin, diluted with 20 to 30 gallons of water. Immerse 15 minutes and wash. 8). FAST PURPLE FOR COTTON. (For 20 lbs. cotton.) Mordant with copperas. Wash slightly; then a bath of muriate of tin. Dye with 4 to 5 lbs. logwood. 9). FAST BLACK ON WOOL.-- Put wool into a strong logwood bath, the stronger the better, and boil for 1 hour. Take out and drain, and put into a Bichromate of Potash bath and keep at 150°F. for about 5 minutes. Then a bath of Fustic or Quercitron. After which wash well in cold water. 10). BLACK FOR COTTON.-- (For 10 lbs.) Steep cotton in hot decoction of 3 lbs. Sumach and let stay over night. Wring out and work for 10 minutes through lime water: then work for ½ hour in a solution of 2 lbs. copperas. It may be either washed from this, or worked again through lime water for 10 minutes. Dye for ½ hour in a warm decoction of 3 lbs. logwood adding ½ pint chamber lye. Take out cotton and add to the same bath 2 oz. copperas. Work 10 minutes, then wash and dry. 1 lb. Fustic is added for jet black. 11). FAST BLACK FOR WOOLLENS.-- (For 50 lbs.) Mordant with 2 lbs. chrome, 1 lb. Tartar, 1 quart Muriate of Tin. Boil 1 hour and wash well. Dye with 25 lbs. logwood and 3 lbs. Fustic. Boil 30 minutes. Take out and add 1 pint Vitriol. Return for 10 minutes, wash and dry. 12). JET BLACK FOR SILK. (For 50 lbs.) Mordant in hot solution of Nitro-Sulphate of Iron at 150°F., work for ½ hour. Wash well, then boil up 18 lbs. Fustic. Put off the boil, enter silk and work for 30 minutes. Take out. Boil 16 lbs. logwood, put off the boil and decant the liquor into fresh bath, add 1 lb. white soap, enter and work from 30 to 40 minutes. Wash well. 13). LAVENDER FOR WOOL. (For 6¼ lbs.) Mordant with 3 oz. Bichromate of Potash, for 45 minutes and wash. Dye with 2 oz. madder, 1 oz. logwood. Enter the wool, raise to the boil and boil for 45 minutes. The proportion of logwood to madder can be so adjusted as to give various shades of claret to purple. 14). BLACK FOR WOOL. Mordant 6¼ lbs. wool with 4 oz. Chrome. Boil for 45 minutes. Dye with 50 oz. logwood, 1 oz. Fustic. Raise to boil and boil for 45 minutes. 15). FAST CHROME BLACK FOR WOOL. (For 40 lbs. wool.) Dissolve 3 lbs. copperas and boil for a short time. Then dip the wool in this for ¾ hour, airing frequently. Take out wool and make dye with 24 lbs. logwood. Boil for ½ hour. Dip ¾ hour, air wool, dip ¼ hour longer and then wash in strong soap suds. 16). LIGHT SILVER DRAB FOR WOOL. (For 50 lbs. wool). ½ lb. logwood, ½ lb. alum. Boil well and enter wool and dip for 1 hour. 17). A FAST LOGWOOD BLUE FOR WOOL. (Highland recipe). Mordant with 3% Bichromate of Potash and boil wool in it for 1½ hours. Wash and dry wool. Make a bath of 15 to 20% logwood with about 3% chalk added to it. Boil the wool for 1 hour, wash and dry. The wool can be greened by steeping it all night in a hot solution of heather, or boiling it in heather till the desired tint is obtained. 18). GREEN BLACK FOR WOOL. (For 50 lbs. wool). Boil 20 minutes with 1 lb. chrome. Dye with 20 lbs. Fustic, 8 lbs. logwood. Boil for ½ hour. 19). SLATE PURPLE. (For 80 lbs. yarn). Mordant with 2 lbs. chrome for 20 minutes. Dye with 10 lbs. logwood & 1 lb. Cudbear. Boil for ½ hour. 20). RAVEN GREY FOR WOOL. (For 60 lbs.) Dissolve 8 oz. Alum and work the wool very quickly for ½ hour at boiling heat; then take it out and add to the same liquor 3 or 4 lbs. copperas, & work it at boiling heat for ½ hour. Then wash. In another copper, boil 1 pailfull of logwood chips for 20 minutes. Put the wool into this for ½ hour; then return it into the alum and copperas for 10 to 15 minutes. 21). DARK RED PURPLE WITH LOGWOOD FOR WOOL.--(For 2½ lbs.) Mordant with 10 oz. alum and 2½ oz. cream of tartar for 1 hour. Let cool in the mordant, then wring out and put away for 4 or 5 days in a linen (or other) bag in the dark. Dye with 1 lb. logwood, and ½ lb. madder. Boil up the logwood and madder in a separate bath and pour through a sieve into the dye bath. Enter the wool when warm and bring to boil. Boil from ½ hour to 1½ hours. Wash thoroughly. 22). VIOLET WITH LOGWOOD FOR SILK. The silk is washed from the soap and drained. For every pound of silk, dissolve in cold water 1 oz. verdigris; when it is well mixed with the water, the silk is immersed and kept in this liquor for an hour. This does not give colour. It is then wrung & aired. A logwood liquor is then made; the silk dipped in it when cold; it takes a blue colour sufficiently dark. The silk is taken out and dipped in a clear solution of alum; it acquires a red which produces a violet on the silk just dyed blue. The quantity of alum is undetermined; the more alum the redder the violet. The silk is then washed. 23). ORDINARY LOGWOOD PURPLE FOR WOOL. (For 1 lb.) Mordant wool with ¼ lb. alum and ½ oz. tartar for 1 hour; wring out and put away in a bag for some days. Dye with ¼ lb. logwood for 1 hour. FOOTNOTES: [12] Early dyers were particular as to the naming of their colours. Here is a list of blues, published in 1669.--"White blue, pearl blue, pale blue, faint blue, delicate blue, sky blue, queen's blue, turkey blue, king's blue, garter blue, Persian blue, aldego blue, and infernal blue." [13] I give here recipes for the simpler vats which can be used on a small scale. The more complicated recipes can only be done in a well-fitted dye house. I would refer the reader to those in "The Art of Dyeing" by Hellot, Macquer and D'Apligny, and "Elements of the Art of Dyeing" by Berthollet. [14] Woad, pastel and Indigo are used in some dye books to mean the same dye, and they evidently have very much the same preparation in making. [15] See page 36. CHAPTER VII. RED. KERMES, COCHINEAL, LAC-DYE, MADDER. _KERMES._ Kermes, or Kerms, from which is got the "Scarlet of Grain" of the old dyers, is one of the old insect dyes. It is considered by most dyers to be the first of the red dyes, being more permanent than cochineal and brighter than madder. In the 10th century it was in general use in Europe. The reds of the Gothic tapestries were dyed with it, and are very permanent, much more so than the reds of later tapestries, which were dyed with cochineal. Bancroft says "The Kermes red or scarlet, though less vivid, is more durable than that of cochineal. The fine blood-red seen at this time on old tapestries in different parts of Europe, unfaded, though many of them are two or three hundred years old, were all dyed from Kermes, with the aluminous basis, on woollen yarn." Kermes consists of the dried bodies of a small scale insect, _Coccus ilicis_, found principally on the ilex oak, in the South of Europe. It is said to be still in use in Italy, Turkey, Morocco and other places. William Morris speaks of the "Al-kermes or coccus which produces with an ordinary aluminous mordant a central red, true vermilion, and with a good dose of acid a full scarlet, which is the scarlet of the Middle Ages, and was used till about the year 1656, when a Dutch chemist discovered the secret of getting a scarlet from cochineal by the use of tin, and so produced a cheaper, brighter and uglier scarlet." Kermes is employed exactly like cochineal. It has a pleasant aromatic smell which it gives to the wool dyed with it. The following recipe for its use is from an old French dye book:-- 20 lbs. of wool and ½ a bushel of bran are put into a copper with a sufficient quantity of water, and suffered to boil half-an-hour, stirring every now and then. It is then taken out to drain. While the wool is draining the copper is emptied and fresh water put in, to which is added about a fifth of sour water, four pounds of Roman Allum grossly powdered and two pounds of red Tartar. The whole is brought to boil, and that instant the hanks are dipped in, which are to remain in for two hours, stirring them continually. When the wool has boiled two hours in this liquor, it is taken out, left to drain, gently squeezed and put into a linen bag in a cool place for five or six days and sometimes longer. This is called leaving the wool in preparation. After the wool has been covered for five or six days, it is fitted to receive the dye. A fresh liquor is then prepared, and when it begins to be lukewarm, take 12 oz. of powdered Kermes for each pound of wool to be dyed, if a full and well coloured scarlet is wanted. If the Kermes was old and flat, a pound of it would be required for each pound of wool. When the liquor begins to boil, the yarn, still moist, (which it will be, if it has been well wrapped in a bag and kept in a cool place) is put in. Previous to its being dipped in the copper with the Kermes, a handful of wool is cast in, which is let to boil for a minute. This takes up a kind of scum which the Kermes cast up, by which the wool that is afterwards dipped, acquires a finer colour. The handful of wool being taken out, the prepared is put in. The hanks are passed on sticks continually stirring and airing them one after the other. It must boil after this manner an hour at least, then taken out and placed on poles to drain, afterwards wrung and washed. The dye still remaining in the liquor may serve to dip a little fresh parcel of prepared wool; it will take some colour in proportion to the goodness and quality of the Kermes put into the copper. _Another Recipe for Dyeing with Kermes._--The wool is first boiled in water along with bran for half-an-hour (½ bushel of bran for 20 lbs. of wool) stirring it from time to time. Drain. Next boil for 2 hours in a fresh bath with a fifth of its weight of alum and a tenth of Tartar. Sour water is usually added. It is then wrung, put into a bag and left in a cool place for some days. The Kermes is then thrown into warm water in the proportion of 12 oz. to every pound of wool. When the liquor boils, a handful of waste wool is thrown in, to take up the dross of the Kermes, and removed. The wool is then put in and boiled for an hour. It is afterwards washed in warm water in which a small quantity of soap has been dissolved. Then washed and dried. "To prepare wool for the Kermes dye, it is to be boiled in water with about â � of its weight in alum, and half as much of Tartar, for the space of two hours and afterwards left in the same liquor four or five days, when being rinsed, it is to be dyed in the usual way with about 12 oz. of Kermes for every pound of wool. Scarlets, etc., given from Kermes, were called grain colours, because that insect was mistaken for a grain. Wool prepared with a nitro-muriatic solution of tin (as is now practised for the cochineal scarlet) and dyed with Kermes takes a kind of aurora, or reddish orange colour."--Bancroft. _COCHINEAL_ The dried red bodies of an insect (_Coccus Cacti_) found in Mexico are named Cochineal. RECIPES FOR DYEING. 1). SCARLET FOR WOOL. For each pound of wool put 20 quarts of water. When the water is warm, add 2 oz. Cream of Tartar, 1½ drachms of powdered Cochineal. When the liquor is nearly boiling, put in 2 oz. of Solution of Tin (which the Dyers call Composition for Scarlet). As soon as it begins to boil, the wool, which has been wetted, is dipped and worked in the liquor for an hour and a half. A fresh liquor is then prepared, 1½ oz. of starch is put in and when the water is warm 6½ drachms of Cochineal. When nearly boiling 2 oz. of solution of tin is put in. It must boil, and then the wool is put in and stirred continually for 1½ hours. It is then taken out, wrung and washed. The Scarlet is then in its Perfection. 2). COCHINEAL FOR COTTON. Prepare 50 lbs. of cotton with 15 lbs. Sumach, 10 lbs. Alum. Dye with 2¼ lbs. of Cochineal. Leave for 24 hours in the Sumach; lift; winch 2 to 3 hours in a hot solution of Alum; wash in two waters, then boil up the cochineal; put off the boil, enter cotton & winch till colour be full enough; then wash and dry. 3). ORANGE RED FOR WOOL. 1). Mordant wool with Alum. 2). Dye in a bath of weak Fustic. Wash and Dry. 3). Put into cold water, Cream of Tartar, Tin, Pepper and Cochineal. When warm, enter the wool and boil. 4). PINK WITH COCHINEAL FOR WOOL. (For 60 lbs. wool). 5 lbs. 12 oz. alum. Boil and immerse wool for 50 minutes. Then add 1 lb. Cochineal and 5 lbs. cream of tartar. Boil and enter wool while boiling, till the required colour is got. 5). SCARLET FOR WOOL. (For 100 lbs.) 6 lbs. of Tartar are thrown into the water when warm. The bath is stirred briskly and when hot ½ lb. powdered cochineal is added and well mixed. Then 5 lbs. of clear solution of Tin is carefully mixed in. When it is boiling the wool is put in and moved briskly. After 2 hours it is taken out, aired and washed. The second bath. When the water is nearly boiling 5¾ lbs. of powdered cochineal is put in. A crust will form on the surface which will open in several places. Then 13 to 14 lbs. of solution of tin is poured in. After this is well mixed, the wool is entered and stirred well. Boil for an hour, then wash and dry. These two processes can be done together with good result. The colour can be yellowed by fustic or turmeric. More tartar in the second bath increases the colour. The scarlet may be brightened by common salt. Alum will change the scarlet to crimson, the wool being boiled in a solution of it for one hour. 6). CRIMSON FOR WOOL. Mordant with 2½ oz. alum and 1½ oz. tartar for every lb. of wool. Then dye with 1 oz. cochineal. Solution of tin is sometimes added. Also salt. 7). VIOLET FOR WOOL. Mordant with 2 oz. alum for 1 lb. wool. Dye with 1 oz. cochineal and 1 oz. of solution of iron in which the wool is kept till the shade is reached. 8). SCARLET WITH COCHINEAL, FOR WOOL. (For 100 oz. clean wool). Put 6 oz. Oxalic acid, 6 oz. Stannous Chloride (Tin Crystals), 8 oz. powdered cochineal in a bath containing about half the quantity of water required to cover wool. Boil 10 minutes, then add sufficient water to cover wool. Enter the wool, work well in the dye and boil for ¾ hour, after which take out the wool, wash and dry. 9). PURPLE, FOR WOOL. (For 2½ lbs. wool). Mordant with Bichromate of Potash, 1½ oz. in 10 gallons of water. Dye with 6 to 8 oz. cochineal. With alum mordant (4 oz.) a crimson colour is got. With tin mordant (2 oz.) a scarlet. With iron mordant (2 oz.) a purplish slate or lilac. 10). SCARLET, FOR WOOL. Mordant the wool for 1 to 1½ hours with 6% stannous chloride and 4% cream of tartar. Wash. Dye with 5 to 12% of ground cochineal for 1 to 1¼ hours. To dye the wool evenly, enter it in both the mordant and the dye when the water is warm, and raise gradually to boiling. 11). SCARLET, FOR WOOL. Fill the dye bath half full of water, add 6 to 8% of Oxalic acid, 6% of stannous chloride and 5 to 12 per cent. ground cochineal, boil up for 5 to 10 minutes, then fill up the dye bath with cold water. Introduce the wool, heat up the bath to the boiling point in the course of ¾ to 1 hour and boil ½ hour. Washing between mordanting and dyeing is not absolutely essential. The addition of tartar up to 8 per cent. increases the intensity and yellowness of the colour. In order to obtain bright yellow shades of scarlet it is usual to add a small proportion of some yellow dye to the bath. Wool mordanted with 10 per cent. of Copper sulphate and dyed in a separate bath with cochineal gives a reddish purple, or claret colour. With ferrous sulphate as mordant very good purplish slate or lilac colours can be got. Mordant and dye in separate baths. Use 8 per cent. of ferrous sulphate and 20 per cent. of tartar. 12). CRIMSON FOR SILK. Mordant the silk by working for ½ hour in a concentrated solution of alum, then leave to steep over night. Wash well and dye in a fresh bath containing 40 per cent. of cochineal. Enter the silk at a low temperature and heat gradually to boiling. 13). SCARLET FOR SILK. After boiling and washing, the silk is first slightly dyed with yellow by working it for ¼ hour at 50°C., in a weak soap bath containing about 10 per cent. of Annatto; it is then well washed. Mordant the silk by working it for ½ hour, then steeping it over night in a cold solution of 40 per cent. of nitro-muriate of tin. Wash and dye in a fresh bath with a decoction of 20 to 40 per cent. of cochineal and 5 to 10 per cent. cream of tartar. Enter the silk at a low temperature and heat gradually to boiling. Brighten in a fresh bath of cold water, slightly acidified with tartaric acid. Good results can also be obtained with the single bath method with cochineal, stannous chloride and oxalic acid. With the use of iron mordants very fine shades of lilac may be obtained on silk with cochineal. _LAC DYE._ Like Cochineal and Kermes, Lac is a small scale insect, _Coccus lacca_. It is found in India, Burmah and other Eastern countries; it was introduced into England in 1796. The method of dyeing with lac is very much the same as with cochineal; it yields its colour less readily however, and should be ground into a paste with the tin solution employed and a little hydrochloric acid and allowed to stand for a day before using. It is said to be a faster dye than cochineal, but is often used in combination with it, being a fuller colour though not so bright. A good fast scarlet is produced by the following recipe:--For 100 lbs. wool. 8 lbs. lac, previously ground up with part of the tin spirits, 5 lbs. cochineal, 5 lbs. tartar, 20 lbs. tin spirit. _MADDER._ Madder consists of the ground up dried roots of a plant, (Rubia tinctorum) cultivated in France, Holland, and other parts of Europe, as well as in India. Madder is not much used for silk dyeing, but for wool, linen and cotton it is one of the best dyes. It is also used largely in combination with other dyes to produce compound colours. When used for cotton the colour is much improved by boiling in a weak solution of soap after the dyeing. The gradual raising of the temperature of the dye bath is essential in order to develop the full colouring power of madder; long boiling should be avoided, as it dulls the colour. If the water is deficient in lime, brighter shades are got by adding a little ground chalk to the dye bath, 1 to 2 per cent. Berthollet distinguishes two kinds of madder red on cotton, one of which is given in No. 4. The other is the well-known Turkey red or Adrianople red, a very difficult and complicated dye, but one of the most permanent dyes known. Madder reds are said to be not so beautiful as those from Kermes, lac or cochineal, but my experience has been that with care, the finest reds can be got with madder. Birch leaves are used in Russia to improve the colour of madder. They are added to the dye bath. RECIPES FOR USE OF MADDER. 1). RED FOR WOOL. For 100 oz. (6¼ lbs.) wool. Mordant 8 oz. Alum and 2 oz. Tartar. Boil the wool in the mordant for one hour and wash in cold water. Dye: 50 oz. Madder. Enter the mordanted wool, raise to boil and boil gently for one hour. Wash thoroughly in cold water and dry. If the water is very soft, a small quantity of lime or chalk added to the dye bath improves the shade. Alder bark or alder leaves added to the dye bath darkens the colour. The best results are obtained when the dye bath is maintained just under the boiling point. 2). REDDISH BROWN FOR WOOL. Mordant with 3% bichromate of potash and dye with Madder. Good results can be got by the single bath method. (See page 14, No. 3.) 3). BROWNISH RED FOR WOOL. Mordant the wool with 6 to 8 per cent. of alum and 5 to 7 per cent. of tartar. Dye with 60 to 80% of Madder. Begin the dyeing at about 40°C., and raise the temperature of the bath gradually to 80° to 100°C., in the course of an hour, and continue the dyeing about an hour. Wash and dry. The colour can be brightened by adding a small proportion of stannous chloride to the mordant or it can be added to the dye bath towards the end of the dyeing. Brighter shades are got by keeping the temperature at about 80°C., and prolonging the dyeing process. After dyeing, the colour can be brightened by working the wool at 70°C., in a weak soap bath, or a bath containing bran. 4). BRIGHT RED FOR COTTON.[16] (For 22 lbs.). The cotton must be scoured, then galled in the proportion of 1 part of nut galls to 4 of cotton, and lastly alumed in the proportion of 1 of alum to 4 of cotton. To the solution of alum is added one twentieth of solution of soda ley (½ lb. ordinary soda to 1¾ pints water). It is then dried slowly and alumed again. Then dried slowly again. The more slowly the drying takes place the better the colour. The cotton is then ready to be dyed. Heat the water of the dye bath as hot as the hand can bear; mix in 6½ lbs. madder and stir carefully. When thoroughly mixed, put in the cotton & work for ¾ hour without boiling. Take it out & add about a pint of soda ley. The cotton is then returned to the bath and boiled for 15 to 20 minutes. It is then brightened by passing it quickly thro' a tepid bath with a pint of ley in it. It is then washed and dried. 5). BRIGHT ORANGE RED FOR WOOL. For 1 lb. scoured fleece, mordant with 4 oz. alum and 1 oz. cream of tartar. Dissolve the mordant, enter the wool and raise to boiling point and boil for 1 hour. Allow the wool to cool in the mordant. Then wring out and put in a linen bag in a cool place for 4 or 5 days. Soak 8 oz. madder over night in water and boil up before using. Put into dye bath, enter wool when warm, bring gradually to the boil and boil for ¾ hour. 6). BRIGHT RED FOR WOOL. Mordant 1 lb. wool with 5 oz. of Alum, and 1 oz. of Tartar; leave to drain and then wring out; put into a linen bag and leave in a cool place for several days. (The wool should still be damp when taken out to dye; if it is dry, damp with warm water). If the Tartar is increased a cinnamon colour is got. Dye with ½ lb. of madder for every pound of wool. The water should not boil, but kept just below boiling for an hour; then boil up for 5 minutes before taking out and washing. With sulphate of copper as a mordant, madder gives a clear brown bordering on yellow (one part of sulphate of copper and 2 parts of madder). 7). RED FOR SILK. The silk is mordanted over night with alum, by steeping it in a cold concentrated solution; wash well and dye in a separate bath with 50 per cent. of madder. Begin dyeing at a low temperature and gradually raise to 100°C. The addition of bran tends to give brighter colours. A small quantity of Sumach could be added if a fuller colour is wanted. After dyeing, wash and then brighten in a boiling solution of soap, to which a small percentage of stannous chloride has been added. Afterwards wash well. By mordanting with Copperas, either alone or after an Alum bath, violet and brown shades can be got. 8). RED WITH MADDER FOR WOOL. Pound up carefully without heating some roots of madder. Mordant the wool with Alum, adding some cayenne pepper. Dye with the madder, adding cream of tartar to the dye bath. Birch leaves improve the colour. 9). MADDER RED FOR COTTON. Take a piece of white cotton, about 20 yards. Melt in some water 1 lb. of potash; boil the cotton in this for 20 minutes, then rinse it. Put 4 lbs. of the best Sumach in the copper and fill it up with boiling water, and boil for 10 minutes. Put to cool and work the cotton well in this for an hour. Take it out and give it a scalding hot alum and sugar of lead bath for half-an-hour; rinse in two waters; put it back in the sumach for half-an-hour; then alum again for 20 minutes. Rinse. Put 2 lbs. of madder into hot water and boil gently for a few minutes. Put in the cotton, work well and boil for half-an-hour gently. After, give it a hot alum for 20 minutes, and rinse. Put 1 lb. fresh madder in the copper, put in the cotton and boil for 20 minutes. Then wash. 10). RED FOR COTTON. Scour the cotton. Then gall in the proportion of 1 of gall nuts to 4 of cotton. Then alum in the proportion of 1 of alum to 4 of cotton, with a little soda and tartar added. Dissolve the alum, etc., and put in the cotton, and boil half-an-hour. Cool down and ring out. Then dry slowly. Repeat the aluming. Put madder into water and when hot dip in cotton for ½ hour, keeping it under boiling point, then boil up for ¼ hour and wash. Dry. 11). MADDER RED FOR COTTON & LINEN. (For 1 lb.) 1st Mordant.--Boil 1 oz. ground gall nuts in 5 quarts of water for ½ hour. Put in thread and soak for 24 hours. Dry. 2nd Mordant.--Melt 2 oz. of alum, â � oz. of Turmeric, and ½ oz. of gum Arabic in two quarts of water, over a slow fire. Let cool. Melt 1 oz. soda, 1 oz. arsenic, ¼ oz. potash (crushed) in a bath, and when dissolved, add the alum, turmeric and gum Arabic mixture. Stew ½ hour. Put in thread, which should be covered with the liquid, and let it soak for 24 hours. Dry. 1st. Bath.--Put 2 oz. Madder into 10 quarts of water, heat up to boiling but do not let it boil. Put in thread and stir well for 1 hour. 2nd. Bath.--Put 3 oz. Madder in 10 quarts of water; treat as in first bath, from which the thread should be taken and put straight into the 2nd. bath. Stir for 1 hour. Soak for 24 hours; wash and dry. 3rd. Bath.--Put 3 oz. Madder in 10 quarts water; repeat the process described for 2nd. bath. The thread should be washed in cold water & lastly in warm water in which a little soft soap has been dissolved. When drying do not wring the skeins as this is likely to make the colour uneven. There are a few other red dyes of minor importance which should be mentioned. _BRAZIL WOODS_, various leguminous trees, including lima, sapan and peach wood, dye red with alum and tartar, and a purplish slate colour with bichromate of potash. They are not fast colours. Some old dyers used Brazil wood to heighten the red of madder. _CAMWOOD_, _BARWOOD_, _SANDALWOOD or SANDERSWOOD_, are chiefly used in wool dyeing, with other dye woods such as Old Fustic, and Logwood for browns. They dye good but fugitive red with bichromate of potash, or alum. _RED from LADIES BEDSTRAW._ The crushed roots of this plant are used. Mordant the wool with either alum or bichromate of potash. The red with alum is an orange red, with chrome, a crimson red. Make the dye bath with 30 to 50% of bedstraw roots and boil the mordanted wool in it for an hour. _RED for COTTON._ For 10 lbs. cotton boil 3 lbs. Sumach, let the cotton steep in this over night: wring out and work in red spirits (1 gill to a gallon of water). Wring out and wash well. Boil up 3 lbs. limawood (or Brazil or Peach wood) and 1 lb. fustic. Work the cotton in this ½ hour, as warm as the hand can bear; add 1 gill red spirits and work 15 minutes longer. Wash. FOOTNOTE: [16] This recipe can also be used for linen, but linen takes the colour less easily than cotton, and should have the various operations repeated as much as possible. CHAPTER VIII. YELLOW. WELD. OLD FUSTIC. TURMERIC. QUERCITRON. DYER'S BROOM. HEATHER, AND OTHER YELLOW DYES. "There are ten species of drugs for dyeing yellow, but we find from experience that of these ten there are only five fit to be used for the good dye--viz. Weld, savory, green wood, yellow wood and fenugrec". "Weld or wold yields the truest yellow, and is generally preferred to all the others. Savory and green wood, being naturally greenish, are the best for the preparation of wool to be dyed green: the two others yield different shades yellow".--Hellot. _WELD_ Weld, _Reseda luteola_, an annual plant growing in waste sandy places. The whole plant is used for dyeing except the root. It is the best and fastest of the yellow natural dyes. Hellot's directions for dyeing with weld are the following:--"Allow 5 or 6 lbs. of weld to every pound of stuff: some enclose the weld in a clean woollen bag, to prevent it from mixing in the stuff; and to keep the bag down in the copper, they put on it a cross of heavy wood. Others hold it in the liquor till it has communicated all its colour, and till it falls to the bottom: the stuff is then suspended in a net, which falls into the liquor, but others, when it has boiled, take out the weld with a rake and throw it away." The plant is gathered in June and July, it is then carefully dried in the shade and tied up into bundles. When needed for dyeing it is broken up into pieces or chopped finely, the roots being discarded and a decoction is made by boiling it up in water for about ¾ hour. It gives a bright yellow with alum and tartar as mordant. With chrome it yields an old gold shade; with tin it produces more orange coloured yellows; with copper and iron, olive shades. The quantity of weld used must be determined by the depth of colour required. The dye bath is prepared just before dyeing, the chopped weld being put into weighted bags and boiled in soft water for ½ to 1 hour. 2% of Stannous chloride added to the mordant gives brilliancy and fastness to the colour. Bright and fast orange yellows are got by mordanting with 8% Stannous chloride instead of alum. With 6% copper sulphate and 8% chalk, weld gives a good orange yellow. Wool mordanted with 4% of ferrous sulphate and 10% tartar and dyed in a separate bath with weld with 8% chalk, takes a good olive yellow. 8% of alum is often used for mordant for weld. The dye bath should not be above 90°C. It is good to add a little chalk to the dye bath as it makes the colour more intense, while common salt makes the colour richer and deeper. "Woollen dyers frequently add a little stale urine or lime and potash to the water in which it is boiled. They commonly employ 3 or 4 oz. of alum and one of tartar for each pound of the wool. Tartar is supposed to render the yellow colour a little more clear and lively."--Bancroft. Weld is of greater antiquity than most, if not all other natural yellow dyes. It is cultivated for dyeing in France, Germany and Italy. It is important for the silk dyer, as it dyes silk with a fast colour. The silk is mordanted in the usual way with alum, washed and dyed in a separate bath of 20 to 40% weld, with a small quantity of soap added. After dyeing, the colour is brightened by working the silk for 10 minutes in a fresh soap bath with a little weld added to it. Wring out without washing. RECIPES FOR DYEING WITH WELD. 1). YELLOW FOR SILK. Scour the silk in the proportion of 20 lbs. soap to 100 lbs. of silk. Afterwards alum and wash. A bath is made of 2 parts weld for 1 of silk, and after ¼ hour's boiling, it is filtered through a cloth into another bath. When this bath is cooled a little, the silk is immersed and turned about till dyed. The weld is in the meantime boiled up again with a little pearl ash, and after being strained, it is added to the first bath (part of the first bath having been thrown away) until the desired colour is got. The bath must not be too hot. If more golden yellows are wanted, add some annotto to the second bath. 2). YELLOW FOR COTTON. Scour the cotton in a lixivium of wood ashes, wash and dry. It is alumed with ¼ of its weight of alum. After 24 hours it is taken out of the bath and dried without washing. A weld bath is prepared with 1¼ parts weld to 1 of cotton, and the cotton dipped in till the shade is got. It is then worked in a bath of sulphate of copper (¼ copper to 1 of cotton) for 1½ hours. It is next thrown, without washing, into a boiling solution of white soap (¼ soap to 1 cotton). It is boiled for 1 hour, then washed and dried. 3). DEEP YELLOW FOR COTTON OR LINEN. 2½ parts of weld for 1 of cotton, with a little copper sulphate added to the bath. The cotton is well worked in this till the cotton has the desired colour. It is then taken out and a little soda ley is poured in. It is returned and worked in this for ¼ hour, then washed and dried. 4). OLD GOLD FOR WOOL. Mordant with 2% chrome and dye with 60% of weld in a separate bath. 3% of chalk adds to the intensity of colour. 5). YELLOW FOR WOOL. Boil wool with 4% of alum for 1 to 2 hours, and dye in a separate bath of 50 to 100% weld for 20 minutes to an hour at 90°C. 6). YELLOW FOR WOOL. Mordant with alum and tartar, and dye with 5 or 6 lbs. of weld for every lb. of wool. Common salt deepens the colour. If alum is added to the dye bath, the colour becomes paler and more lively. Sulphate of iron inclines it to brown. 7). WELD YELLOW FOR SILK. Work the silk (1 lb.) for an hour in a solution of alum, 1 lb. to the gallon, wring out and wash in warm water. Boil 2 lbs. weld for ½ hour; strain and work the silk in this for ½ hour. Add 1 pint alum solution to the weld bath and return the silk; work ten minutes, wring out and dry. _OLD FUSTIC._ Fustic is the wood of _Morus tinctoria_, a tree of Central America. It is used principally for wool. It does not produce a fast dye for cotton. With Bichromate of Potash as mordant, Old Fustic gives old gold colour. With alum it gives yellow, inclining to lemon yellow. The brightest yellows are got from it by mordanting with Tin. With copper sulphate it yields olive colours. (4 to 5% copper sulphate and 3 to 4% tartar). With ferrous sulphate, darker olives are obtained (8% ferrous sulphate). For silk it does not produce as bright yellows as weld, but can be used for various shades of green and olive. Prolonged dyeing should always be avoided, as the yellows are apt to become brownish and dull. The chips should be tied up in a bag and boiled for ½ hour before using. It is still better to soak the wood over-night, or boil up in a small vessel and strain into the dye bath. The proportion of Fustic to be used for a good yellow is 5 to 6 parts to 16 parts of wool. RECIPES FOR DYEING WITH OLD FUSTIC. 1). OLD GOLD FOR WOOL. Boil the wool with 3 to 4% Chrome for 1 to 1½ hours. Wash, and dye in a separate bath for 1 to 1½ hours at 100°C. with 20 to 80% of Old Fustic. 2). LIGHT YELLOW FOR SILK. Work the silk for ¼ to ½ hour at 50° to 60°C. in a bath containing 16% alum and a decoction of 8 to 16% of old Fustic. For dark yellow the silk is mordanted with alum, washed and dyed for about an hour at 50°C., with 50 to 100% of Fustic. The colour can be made faster and brighter by working the silk in a cold solution of nitro-muriate of Tin for an hour. 3). BRIGHT YELLOW FOR WOOL. Mordant wool with 8% of stannous chloride for 1 to 1½ hours, and 8% of tartar. Wash, and dye with 20 to 40% of Fustic at 80° to 100°C. for 30 to 40 minutes. 4). OLD GOLD FOR WOOL. Mordant 6¼ lbs. (100 oz.) wool with 3 oz. chrome, for ¾ hour and wash. Dye with 24 oz. Fustic & 4 oz. madder for 45 minutes. 5). YELLOW FOR WOOL. Mordant 6¼ lbs. wool with 3 oz. chrome, for ¾ hour and wash. Dye with 6 oz. Fustic, 2 drachms logwood. Boil ¾ hour. 6). BRIGHT YELLOW FOR WOOL. (Single bath method). Fill the dye bath ½ full of water, add 2% oxalic acid, 8% stannous chloride, 4% tartar and 40 per cent. of Fustic. Boil up for 5 or 10 minutes, then fill the bath with cold water. Put in the wool & heat up the bath to boiling in the course of ¾ to 1 hour, & boil for ½ hour. 7). YELLOW FOR WOOL. (Single bath). 4% stannous chloride, 4% oxalic acid and 50% Fustic. 8). YELLOW FOR SILK. (5 lbs.) Work the silk through an alum solution of 1 lb. to a gallon of water. Wash in warm water. Boil 2 lbs. Fustic for ½ hour in water and in this work the silk for ½ hour. Lift and add 1 pint of the alum solution. Work 10 minutes longer, then wash and dry. 9). FUSTIC YELLOW FOR SILK. (5 lbs.) Alum the silk. Boil up 3 lbs. Fustic and work silk in it while hot for ½ hour. Lift, add 2 oz. red spirits. Work for 15 minutes. Wash out in cold water. Work 10 minutes in a soap solution. Wring out and dry. 10). BUFF COLOUR ON WOOL. (45 lbs.) Boil 4½ lbs. Fustic and 1½ lbs. madder. Add 7 lbs. alum and boil up together. Allow to cool a little, enter wool and boil for ½ hour. 11). YELLOW FOR WOOL. Mordant with alum and tartar. Solution of tin increases the colour; salt makes it deeper. 5 or 6 oz. Fustic for every pound of wool. _TURMERIC_ Turmeric is a powder obtained from the ground up tubers of _Curcuma tinctoria_, a plant found in India and other Eastern countries. It gives a brilliant orange yellow, but it has little permanence. It is one of the substantive colours and does not need any mordant. Cotton has a strong attraction for it, and is simply dyed by working in a solution of Turmeric at 60°C. for about ½ hour. With silk and wool it gives a brighter colour if mordanted with alum or tin. Boiling should be avoided. It is used sometimes for deepening the colour of Fustic or Weld, but its use is not recommended as although it gives very beautiful colours, it is a fugitive dye. As Berthollet says "The shade arising from the Turmeric is not long of disappearing in the air." _QUERCITRON._ Quercitron is the inner bark of the _Quercus nigra_ or _Q. tinctoria_, a species of oak growing in the United States and Central America. It was first introduced into England by Bancroft in 1775 as a cheap substitute for weld. He says, "The wool should be boiled for the space of 1 or 1¼ hours with one sixth or one eighth of its weight of alum; then without being rinsed, it should be put into a dyeing vessel with clean water and also as many pounds of powdered bark (tied up in a bag) as there were used of alum to prepare the wool, which is to be then turned in the boiling liquor until the colour appears to have taken sufficiently: and then about 1 lb. clean powdered chalk for every 100 lbs. of wool may be mixed with the dyeing liquor and the operation continued 8 or 10 minutes longer, when the yellow will have become both lighter and brighter by this addition of chalk." QUERCITRON FOR SILK. _Bancroft._ 1 to 2 lbs. of bark to every 12 lbs. silk according to shade required. The bark, tied up in a bag, should be put into the dyeing vessel whilst the water is cold, as soon as it gets warm the silk, previously alumed, should also be put in and dyed as usual. A little chalk should be added towards the end of the operation. A little murio sulphate of tin is used where more lively shades of yellow are wanted. Boil at the rate of 4 lbs. bark to every 3 lbs. of alum & 2 lbs. murio sulphate of tin with a suitable quantity of water, for 10 to 15 minutes. Reduce the heat so that the hand can bear it, put in the silk and dye till it has acquired the shade. By adding suitable proportions of sulphate of indigo to this yellow liquor and keeping it well stirred, various and beautiful shades of Saxon green may be dyed. By dissolving different proportions of copperas or copperas and alum in the warm decoction of bark, silk may in the same way be dyed of all the different shades of olive and drab colours\. FOR COTTON AND LINEN. Soak the yarn in a liquor made by dissolving ¼ of its weight of alum in the necessary water, to which it will be highly advantageous to add at the rate of 1 lb. potash or 10 oz. chalk for every 6 or 7 lbs. alum. The yarn is taken out and dried well: being afterwards rinsed, it is to be dyed in cold liquor made by boiling 1¼ lbs. of the plant for each lb. of yarn, which, after having received a sufficient body of colour, is to be taken out of the dyeing liquor and soaked for an hour and more in a solution of sulphate of copper (blue vitriol) containing at the rate of 3 or 4 oz. for every pound of yarn: it is then removed without being washed, put into a boiling solution of hard soap, containing 3 or 4 oz. soap for each pound of yarn. Stir well and boil for about ¾ hour or more. Then wash and dry. And again, take a sufficient quantity of acetate of alumina. This is made by dissolving 3 lbs. alum in a gallon of hot water, then adding 1 lb. sugar of lead, stirring well for 2 or 3 days, afterwards adding about 2 oz. potash and 2 oz. powdered chalk, (carbonate of lime), mix with warm water and soak linen or cotton well in this for 2 hours, keeping warm; squeeze out, dry; soak again in mordant, squeeze; dry; soak in lime water, dry; this mordanting and liming can be repeated if a fast yellow is required: it should then be well washed. 12 to 18 lbs. of Quercitron bark, for every 100 lbs. cotton or linen, is tied up in a bag and put in cold water, and slightly heated. The cotton is put in, stirring for an hour to an hour and a half while the water gets warm: then the liquor is heated to boiling point and the cotton boiled a few minutes only. Slow raising to boiling point gives the best colour. Instead of using acetate of alumina, the cotton can be impregnated with some astringent such as galls or myrobalans (1 lb. in 2 or 3 gallons of water with a little soda). Macerate the cotton an hour or two in this and dry, then a solution of alum (8 lbs. alum, 1 lb. chalk, in 6 gallons of water) soak cotton 2 hours, and dry, then soak in lime water and dry. Second time in alum and dry. Then wash and dye slowly in the Quercitron. This is a lasting yellow for cotton or linen. _OTHER YELLOW DYES._ "Root of the dock, bark of the Ash tree, leaves of the almond, peach and pear trees, all give good yellow dyes, more or less fine according to the time they are boiled and in proportion to the Tartar and alum used. A proper quantity of alum brings these yellows to the beautiful yellows of the weld. If the Tartar is in greater quantity, these yellows will border on the orange, if too much boiled they take brown shades." From a dyeing book, 1778. _BARBERRY._ The roots and bark of _Berberis Vulgaris_, used principally for silk dyeing, without a mordant. The silk is worked at 50° to 60°C. in a solution of the dye wood slightly acidified with sulphuric, acetic or tartaric acid. For dark shades, mordant with stannous chloride. _DYERS BROOM._ _Genista tinctoria._ The plant grows on waste ground. It should be picked in June or July & dried. It can be used with an alum and tartar mordant and gives a good bright yellow. It is called greening weed and used to be much used for greening blue wool. _PRIVET LEAVES_, _Ligustrum vulgare_, dye a good fast yellow with alum and tartar. _HEATHER._ Most of the heathers make a yellow dye, but the one chiefly used is the Ling, _Calluna vulgaris_. The tips are gathered just before flowering. They are boiled in water for about half an hour. The wool, previously mordanted with alum, is put into the dye bath with the liquor, which has been strained. It is then covered up closely and left till the morning. Or the wool can be boiled in the heather liquor till the desired colour is obtained\. RECIPES:--1). YELLOW FOR WOOL. For 6¼ lbs. mordant with 5 oz. alum for 1 hour and wash. Boil up 8 oz. heather twigs, leaves and flowers. Enter the wool and boil for 1 hour. Wash in cold water & dry. 2). GOLDEN YELLOW FOR WOOL. For 6¼ lbs. mordant with 3 oz. bichromate of potash for ¾ hour. Wash in cold water. Dye with 50 oz. heather and boil for 45 minutes. CHAPTER IX. BROWN AND BLACK. CATECHU. ALDER BARK. SUMACH. WALNUT. PEAT SOOT. LOGWOOD, AND OTHER DYES _CATECHU._ Catechu, (Cutch) is an old Indian dye for cotton. It can be used for wool, and gives a fine rich brown. It is obtained from the wood of various species of Areca, Acacia, and Mimosa trees. Bombay Catechu is considered the best for dyeing purposes. Catechu is soluble in boiling water. It is largely used by the cotton dyer for brown, olive, drab, grey, and black. The ordinary method of dyeing cutch brown on cotton is to steep the cotton in a hot solution of catechu, containing a small addition of copper sulphate, and leave it in the solution for several hours. To 7 or 8 gallons of water put 1 lb. catechu and boil till all is dissolved, then add 1 to 2 ozs. of sulphate of copper and stir. It is then put into a boiling chrome bath (3%) for ½ hour. For deep shades the dyeing and chroming operations are repeated. With alum mordanted cotton, the colour is a yellowish brown, with tin it becomes still yellower. With iron it is brownish or greenish grey. When catechu only is used, a darker shade of brown is got by adding to the catechu 6% of its weight of copper sulphate. When mordants are used, they may be applied before or after the chrome bath, the cotton being worked in their cold solution. 1). CATECHU BROWN FOR COTTON. (10 lbs.) Work the cotton at a boiling heat for 2 hours, or steep for several hours in a cool liquid, in 2 lbs. catechu. (To each 7 or 8 gallons of water put 1 lb. of catechu, and boil till all is dissolved, then add 2 oz. sulphate of copper and stir). Wring out and then work for ½ hour in a hot solution of chrome, 6 oz. Wash in hot water. If soap is added the colour is improved. Any depth of colour can be got by repeating the operations. 2). BROWN FOR COTTON. Soak cotton in warm water. Boil for ½ hour in a solution of catechu, in the proportion of 1 oz. of catechu to 5 oz. of cotton. Put it into a 3% solution of chrome for ½ hour and boil. Then repeat these two operations till the colour is obtained. Then boil in a bath of Fustic. 3). BROWN FOR COTTON. (100 lbs.) Boil 20 lbs. catechu in water: dissolve in the liquid 10 lbs. alum and let it settle: enter the yarn into the hot liquid and after working well take out and enter into a fresh bath of boiling water with 4 lbs. of chrome. Rinse and soften with oil and soap. 4). CREAM COLOUR FOR COTTON WITH CATECHU. (11 lbs). Boil out ¾ oz. of catechu in water, and dissolve 2 lbs. 3 oz. curd soap in the clear liquid. Enter the cotton at 190° F. and work for an hour. 5). CATECHU FAST BROWN. (50 lbs.) Steep yarn over-night in a decoction of 10 lbs. cutch. Lift & work in a hot solution of chrome, rinse & dry. 6). LIGHT FAST CATECHU BROWN FOR COTTON. (50 lbs.) Boil 20 lbs. catechu in one boiler and 5 lbs. chrome in another. Enter in the catechu bath first, work 20 minutes, and wring out: then through the chrome 10 minutes, and wring out. Through catechu again, then chrome. Repeat this till dark enough, finishing with catechu. 7). LIGHT CATECHU BROWN FOR COTTON. (20 lbs). 3 lbs. of catechu and 3 oz. copper sulphate, boil up, and put into a bath of warm water. Enter cotton and work for ½ hour; wring out. In another bath of hot water dissolve 8 oz. of chrome. Enter cotton when boiling, and work for ½ hour. Then wash. 8). CATECHU BLACK FOR COTTON. Work the cotton in a hot decoction of catechu, allowing it to steep in the bath till cold, then work it in a cold solution of iron. Wash, and dye in a cold or tepid bath of logwood, and finally pass through a solution of chrome. 9). CATECHU BROWN FOR WOOL. The wool is boiled for 1 to 1½ hours, with 10 to 20% catechu, then sadden with 2 to 4% of copper sulphate, ferrous sulphate, or chrome, at 80° to 100°C., in a separate bath for ½ hour. 10). CATECHU STONE DRAB. (10 lbs. cotton). Work the cotton for ¼ hour with 2 pints catechu (1 lb. catechu to 7 or 8 gallons water; boil and add 2 oz. copper sulphate) in hot water, lift and add 2 oz. copperas in solution. Work for ¼ hour and wash. Add 2 oz. logwood to a bath of warm water & work cotton in this for 10 minutes. Lift and add ½ oz. alum. Work 10 minutes; wring out and dry. _ALDER BARK_ The bark and twigs of alder are used for dyeing brown and black. For 1 lb. wool use 1 lb. alder bark. Boil the wool with it for 2 hours, when it should be a dull reddish brown. Add ½ oz. copperas for every pound of wool for black. _SUMACH_ Sumach is the ground up leaves and twigs of the _Rhus coriaria_ growing in Southern Europe. It dyes wool a yellow and a yellow brown, but it is chiefly used in cotton dyeing. _WALNUT_ The green shells of the walnut fruit and the root are used for dyeing brown. The husks are collected when the fruit is ripe, put into a cask and covered with water. In this way they can be kept for a year or more; it is said the longer they are kept the better colour they give. Without a mordant the colour is quite fast, but if the wool is mordanted with alum a brighter and richer colour is got. When used they are boiled in water for ¼ hour, then the wool is entered and boiled till the colour is obtained. Long boiling is not good as it makes the wool harsh. It is much used as a "saddening" agent; that is for darkening other colours. William Morris says:-- "The best and most enduring blacks were done with this simple dye stuff, the goods being first dyed in the indigo or woad vat till they were a very dark blue, and then browned into black by means of the walnut root." * * * * * "Of all the ingredients used for the brown dye, the walnut rind is the best. Its shades are finer, its colour is lasting, it softens the wool, renders it of a better quality, and easier to work. To make use of this rind, a copper is half filled, and when it begins to grow luke-warm, the rind is added in proportion to the quantities of stuffs to be dyed and the colour intended. The copper is then made to boil, and when it has boiled a quarter-of-an-hour, the stuffs which were before dipped in warm water, are put in. They are to be stirred and turned until they acquire the desired colour."--James Haigh, 1797. _PEAT SOOT_ gives a good shade of brown to wool. Boil the wool for 1 to 2 hours with peat soot. Careful washing is required in several changes of water. It is used sometimes for producing a hazel colour, after the wool has been dyed with weld and madder. _OAK BARK._ Mordant with alum and dye in a decoction of oak bark. _ONION SKINS._ (Brown.) Mordant the wool with alum and a little cayenne pepper. Boil it up lightly and keep warm for 6 days. Drying 2 or 3 times in between makes the colour more durable. Dry. Boil a quantity of onion skins, and cool; then put in wool and boil lightly for half-an-hour to an hour; then keep warm for a while. Wring out and wash. _MADDER for BROWN._ (For 2½ lbs. wool). Mordant with 2 oz. copperas and 2 oz. cream of tartar. Dye with madder. _MADDER, ETC., for FRENCH BROWN._ (For 50 lbs. wool.) Mordant with 1½ lbs. chrome. Dye with 6 lbs. Fustic, 1 lb. madder, ½ lb. cudbear, 1 lb. Tartar. If not dark enough add 8 oz. logwood. Boil for ½ hour. Wash and dry. _FOR BLACK THREAD._ (From an old Dutch book on Dyeing. 1583). "Take a quantity of broken or bruised galls and boil them in water in a small pot and when they have a little boiled, take out all the galls and put into the same pot so much Copperas as ye had of galles and put therewith a little gumme of Arabic and then give it again another boiling. So let it boil a little, and with the said dye ye shall colour therein your thread, then take it forth and ye shall see it a fair shining black." _TAN SHADE._ (for 6¼ lbs. wool). Mordant with 3 oz. Chrome for 45 minutes and wash in cold water. Boil for ½ hour, in a bag, 5 oz. madder, 4 oz. Fustic, ½ oz. logwood. Enter the wool, raise to the boil, and boil for 45 minutes. By altering the proportions of madder & fustic various shades of brown can be got. _A GOOD BLACK_ for cotton, (20 lbs.) to stand milling and scouring. Steep all night with 6 lbs. of Sumach, pass through lime liquor and sadden with copperas; repeat in each of the last 2 tubs, adding more lime and copperas to each. Pass through logwood and wash. Soften with a little oil and soda ash. _A GOOD BLACK_ for cotton, (20 lbs.) In a tub of cold water add 5 lbs. sumach, give a few turns and let it steep in it all night; then in another tub of cold water add a few pails of lime water, wring out; in another tub add 2 lbs. dissolved copperas and a pailful of old Sumach liquor. Enter, give 6 turns, wring out. In lime tub put two pails more lime liquor. Scald 2 lbs. logwood, 1 lb. Fustic in water; enter cotton, give 10 turns, sadden with a little copperas in the same liquor. Soften with a little oil and soda ash. _BLACK FOR LINEN AND COTTON._ The yarn is first of all scoured in the ordinary way, galled, alumed, and then turned through a bath of weld. It is then dyed in a decoction of logwood to which one fourth part of sulphate of copper must be added for one part of yarn. It is then washed. It is dyed in a bath made with one part of madder for two of yarn. The yarn is then turned through a bath of boiling soap water, washed and dried. _DOESKIN BLACK._ (For 100 lbs. wool.) Camwood 8%. Boil for 50 minutes. Then add Chrome 3%, Alum 1%, Argol 1%. Boil for 50 minutes, take out of dye and allow to stand overnight. Dye in 45% logwood, 8% Fustic, 4% Sumac. Boil for 1½ hours, wash and dry. A fast permanent colour. _GREEN BLACK FOR WOOL._ Mordant with 2% Chrome and 25% Sulphuric acid. Boil 1½ hours; and leave over-night. Dye with 40% logwood, and 10% Fustic. Boil 1 hour. Wash. _BROWNISH BLACK FOR WOOL._ (For 1 lb.) Mordant with 3 per cent. Chrome. Dye with 2 oz. Fustic, 2 oz. logwood, 1 oz. madder, and 1 oz. copperas. _BROWN FOR WOOL._ Mordant 2½ hours with alum; dye with pine needles (larch) collected in Autumn when they drop. "_BLACK_ is obtained from the whole plant of _Spirea Ulmaria_, but especially the root. It is gathered then dried in the sun, and a strong decoction made by boiling for some hours, (a large handful to 3 pints of water). After it has boiled slowly for 2 to 3 hours, stale urine is added to supply the loss by evaporation. Then set aside to cool. The cloth to be dyed, is rubbed strongly with bog iron ore, previously roughened and moistened with water. It is then rolled up and boiled in the decoction. This is of a brilliant black. A fine black is said to have been formerly obtained from the roots of _Angelica Sylvestris_."--(Edmonstone on the Native Dyes of the Shetland Islands, 1841.) William Morris says; "[17]Black is best made by dyeing dark blue wool with brown; and walnut is better than iron for the brown part, because the iron-brown is apt to rot the fibre; as you will see in some pieces of old tapestry, or old Persian carpets, where the black is quite perished, or at least in the case of the carpet--gone down to the knots. All intermediate shades of flesh colour can be got by means of weak baths of madder and walnut "saddening;" madder or cochineal mixed with weld gives us orange, and with saddening (walnut) all imaginable shades between yellow and red, including the ambers, maize-colour, etc." From a Dye Book of 1705.--"Black may be compared to Night and Death, not only because all other colours are deepened and buried in the Black Dye, but that as Death puts an end to all Evils of Life, tis necessary that the Black Dye should remedy the faults of other colours, which have been occasioned by the deficiency of the Dyer or the Dye, or the change of Fashion according to the times and caprice of man." FOOTNOTE: [17]--For other recipes for Black, see Chapter VI on Logwood. CHAPTER X. GREEN Green results from the mixing of blue and yellow in varying proportions according to the shade of colour required. _Berthollet_ says:-- "Many different plants are capable of affording green colours; such as, the field broom grass, _Bromus secalinus_; the green berries of the berry bearing alder, _Rhamnus frangula_; wild chervil, _Chærophyllum silvestre_; purple clover, _Trifolium pratense_; common reed, _Arundo phragmites_; but these colours have no permanence."[18] _Hellot_ says:--"It is impossible to obtain more than one colour from a mixture of blue and yellow, which is green; but this colour comprehends an infinite variety of shades, the principal of which are the Yellow green, the Light green, the Gay green, the Grass green, the Laurel green, the Molequin green, the Deep green, the Sea green, the Celadon green, the Parrot green, and, I shall add, the Duck-wing green, and the Celadon green with Blue. All these shades and the intermediate ones are made after the same manner and with the same ease. The stuff or wool dyed blue, light or dark, is boiled with Alum and Tartar, as is usually done to make white stuff yellow, and then with Weld, Savory, or Greening Wood. The Weld and the Savory are the two plants that afford the finest greens." Another old Dye book says:-- "If you would dye your goods green, you must first dye them yellow with Broom or Dyer's Weed, otherwise Yellow Weed; after which put them into the Blue vat." Every dyer has his particular yellow weed with which he greens his blue dyed stuff. But the best greens are undoubtedly got from weld and fustic. The wool is dyed first in the blue vat; then washed and dried; then after mordanting dyed in the yellow bath. This method is not arbitrary as some dyers consider a better green is got by dyeing it yellow before the blue. But the first method produces the fastest and brightest greens as the aluming after the blue vat clears the wool of the loose particles of indigo and seems to fix the colour. If a bright yellow green is wanted, then mordant with alum after the indigo bath; if olive green, then mordant with chrome. The wool can be dyed blue for green in 3 different ways:--1st. in the indigo vat (see page 68 et seq.); 2nd. with Indigo Extract (see pages 65-67); 3rd. with logwood, the wool having been previously mordanted with chrome (see p. 82, No. 7, and p. 85 No. 17). For a good bright green, dye the wool a rather light blue, then wash and dry; green it with a good yellow dye, such as weld or fustic, varying the proportion of each according to the shade of green required. Heather tips, dyer's broom, dock roots, poplar leaves, saw wort are also good yellows for dyeing green. If Indigo Extract is used for the blue, fustic is the best yellow for greening, its colour is less affected by the sulphuric acid than other yellows. _Bancroft_ gives many recipes for dyeing green with quercitron. He says:-- "Wool which has been first properly dyed blue in the common indigo vat may be made to receive any of the various shades of green which are usually given in this way from weld, by boiling the blue wool (after it has been well rinsed) in water, with about one eighth of its weight in alum, and afterwards dyeing it unrinsed with about the same quantity of Quercitron bark and a little chalk which should be added towards the end of the process. In the same way cloth that has previously received the proper shade of Saxon blue, may be dyed to a beautiful Saxon green: it will be proper to add about 3 lbs. chalk with 10 to 12 pounds of alum for the preparation liquor for 100 lbs. weight of wool which is to be turned and boiled as usual for about an hour, and then without changing the liquor, 10 or 12 lbs. of Quercitron bark, powdered and tied up in a bag, may be put into it, and the dyeing continued. When the dyeing has continued about 15 minutes, it will be proper to add another lb. of powdered chalk, stirring it well in, and to repeat this addition once, twice or three times at intervals of 6 or 8 minutes. The chalk does not merely answer the purpose of decomposing the acid left in the wool by the sulphate of indigo, but it helps to raise the colour and to render it more durable." According to _Bancroft_, Quercitron is the yellow above all others for dyeing greens. He says:-- "The most beautiful Saxon greens may be produced very cheaply and expeditiously by combining the lively yellow which results from Quercitron bark, murio sulphate of tin and alum, with the blue afforded by indigo when dissolved in sulphuric acid, as for dyeing the Saxon blue". For a full bodied green he says "6 or 8 lbs. of powdered bark should be put into a dyeing vessel for every hundred  lbs. wool with a similar quantity of water. When it begins to boil, 6 lbs. murio-sulphate of tin should be added (with the usual precaution) and a few minutes afterwards 4 lbs. alum: these having boiled 5 or 6 minutes, cold water should be added, and then as much sulphate of Indigo as needed for the shade of green to be dyed, stirring thoroughly. The wool is then put into the liquor and stirred briskly for about ½ hour. It is best to keep the water just at the boiling point." RECIPES FOR DYEING GREEN. 1). BOTTLE GREEN FOR SILK WITH FUSTIC. (5 lbs.) Dissolve 2 lbs. alum and 1 lb. copperas in water; work the silk in this for ½ hour; wash in warm water. Work for ½ an hour in a decoction of 6 lbs. Fustic. Lift, and add 2 oz. Indigo Extract. Work 20 minutes. Wash and dry. 2). GREEN FOR WOOL WITH FUSTIC. ½ lb. of wool is mordanted with â � oz. chrome and â � oz. Cream of Tartar for ½ an hour to 1 hour. Soak overnight in water, 3 oz. Fustic and 2½ oz. logwood, and boil for 2 hours. Strain, and enter wool. Boil for 2 hours. 3). GREEN FOR LINEN WITH LARCH BARK. Mordant 4 lbs. linen with ½ lb. alum. Boil for 2½ hours; wring out but do not dry. Boil up a quantity of larch bark and boil linen in this for 2½ hours. 4). FUSTIC GREEN FOR WOOL. (50 lbs.) Mordant wool with 11 lbs. alum. Soak 50 lbs. Fustic over-night, and boil up. Enter the wool and boil for half-an-hour or more. Add Extract of Indigo in small quantities at a time, till the desired colour is got. 5). SAXON GREEN FOR WOOL. Mordant the wool with alum and tartar for half-an-hour; it is then taken out and aired, but not washed. The bath is refreshed with cold water, and half the amount of the solution of Indigo which is to be used is well mixed in. The wool is entered and rapidly stirred for 5 or 6 minutes, without boiling. It is taken out and the rest of the Indigo solution is well mixed in. The wool is put in and boiled for ten minutes; then taken out and cooled. The bath is then three-quarters emptied and filled up with a decoction of fustic. When the bath is very hot, the wool is put in until the desired shade of green is got. 6). GREEN WITH QUERCITRON FOR WOOL. Dye the wool blue in the Indigo vat. Wash well. For 100 parts of wool, put 3 parts of chalk and 10 or 12 of alum. Boil the wool in this for 1 hour. Then to the same bath, add 10 or 12 parts of Quercitron, and continue the boiling for ¼ hour. Then add 1 part of chalk, and this addition is repeated at intervals of 6 to 8 minutes till a fine green colour is brought out. 7). GREEN WITH QUERCITRON FOR COTTON. First, the cotton is dyed a sky blue colour by means of indigo dissolved by potash and orpiment; then it is passed through a strong decoction of sumach, in which it is left until well cooled. It is then dried, passed through the mordant of acetate of alumina, dried again, washed, worked for 2 hours in tepid bath of Quercitron, (26¼ lbs. to 110 lbs. cotton). 8). GREEN WITH INDIGO EXTRACT & WELD FOR WOOL. Mordant 1 lb. wool with 4 oz. alum and ½ oz. cream of tartar. Dye blue with sufficient quantity of Indigo Extract. Wash and dry. Prepare a dye bath with weld which has been previously chopped up and boiled. Enter wool and boil for half-an-hour or more. FOOTNOTE: [18] Note page 42 on British plants which dye green. APPENDIX LICHENS USED FOR DYEING WOOL BROWN. _Continued from page 62_ _S. scrobiculata._ Aik-raw, Oak rag. Found on trees in Scotland and England. _Gyrophora deusta._ Scorched looking gyrophora. Found on rocks in Scandinavia. Linnæus states that it furnishes a paint called "Tousch," much used in Sweden. _G. cylindrica._ Cylindrical gyrophora. On rocks in Iceland. Greenish brown. Also G. deusta. _Alectoria jubata._ Horse hair lichen, Rock hair. On fir trees in England, pale greenish brown. _Parmelia parietina._ Common yellow wall lichen, Wäg-mässa, Wag-laf. England and Sweden on trees, rocks, walls, palings. Used to dye Easter eggs. Used in Sweden for wool dyeing. _Cetraria juniperina._ En-mossa. On trees in Scandinavia. _Borrera flavicans._ Yellow borrera. On trees in Germany, gamboge yellow. _Lecanora candelaria._ Ljus mässa. On trees in Sweden. _Evernia flavicans._ Wolf's-bane evernia. On trees in Scandinavia, gamboge yellow. _Lecidea atro-virens._ Map lichen. On rocks in Scandinavia. _Lepraria chlorina._ Brimstone coloured lepraria. Scandinavia, on rocks. _L. Iolithus._ Viol-mässa. Sweden, on stones. Gives to stones the appearance of blood stains. BIBLIOGRAPHY Prof. G. Henslow. Uses of British Plants. Dr. Plowright. British Dye Plants. (Journal of the Royal Horticultural Society, Vol. 26. 1901.) Sowerby. Useful Plants of Great Britain. Sowerby. English Botany. Professor G. S. Boulger. The Uses of Plants. 1889. Alfred Edge. Some British Dye Lichens. (Journal of the Society of Dyers and Colourists. May 1914). J. J. Hummel. The Dyeing of Textile Fabrics. Clement Bolton. A Manual of Wool Dyeing. 1913. W. Crooks. Dyeing and Tissue Printing. 1882. Rawson, Gardiner and Laycock. A Dictionary of Dyes, Mordants, 1901. James Haigh. The Dyer's Assistant. 1778. James Napier. A Manual of Dyeing Receipts. 1855. James Napier. A Manual of the Art of Dyeing. 1853. A Profitable Boke. (On Dyeing). Translated from the Dutch. 1583. Darwin and Meldola. Woad. ("Nature", Nov. 12, 1896). Mrs. Anstruther Mackay. Simple Home Dyeing. English Encyclopædia. Dyeing. 1802. Gardiner D. Hiscock. 20th Century Book of Recipes, Formulas and Processes. 1907. F. J. Bird. The Dyer's Hand Book. 1875. Hurst. Silk Dyeing and Printing. (Technological Hand Book. 1892). Smith. Practical Dyers' Guide. 1849. T. Sims. Dyeing and Bleaching. (British Manufacturing Industries. 1877.) David Smith. The Dyers' Instructor. 1857. The Dyer and Colour Maker's Companion. 1859. Thomas Love. The Practical Dyer and Scourer. 1854. Knecht, Rawson and Lowenthal. A Manual of Dyeing. 1893. Berthollet. The Art of Dyeing. 1824. George Jarmain. On Wool Dyeing. 6 Lectures. 1876. Hellot, Macquer, M. le Pilleur D'Apligny. The Art of Dyeing Wool, Silk and Cotton. (Translated from the French, 1789. New Edition, 1901.) The Art of Dyeing. (Translated from the German. 1705. Reprint 1913.) R. P. Milroy. Handbook on Dyeing for Woollen Homespun Workers. (Congested Districts Board for Ireland). Dr. W. L. Lindsay. On the Dyeing Properties of Lichens. (Edinburgh New Philosophical Journal, 1855). T. Edmonston. "On the Native Dyes of the Shetland Islands." (Transactions of Botanical Society of Edinburgh, Vol. I. 1841). Edward Bancroft. The Philosophy of Permanent Colours. 1794. Francheville. On Ancient and Modern Dyes, 1767. (Royal Academy of Sciences, Berlin). Parnell's Applied Chemistry.--Article on Dyeing. William Morris. "Of Dyeing as an Art." (Essays by Members of the Arts and Crafts Exhibition Society, 1903). William Morris. "The Lesser Arts of Life." (From Architecture, Industry and Wealth. 1902). Brewster's Edinburgh ncyclopædia. 1830. Dyeing. Sansome. "Dyeing." 1888. John M. Thomson. The Practical Dyer's Assistant. 1849. GLOSSARY AND INDEX. A.--_Adjective dyes_, 24. Dyes which require a mordant. _Alder bark_, 43, 44, 100, 126. _Alizarin._ The chief colouring principle of madder. It is also the name for an extensive series of chemical colours produced from anthracene, one of the coal tar hydrocarbons, discvrd., 1868. _Alkaline ley_, 28. _Almond_, 120. _Amber_, 132. _Alum_, 26-29. _Aluminium sulphate_, 26. _Aniline_, 3. Discovered, 1826 (_añil, Span. indigo_). First prepared from indigo by means of caustic potash. Found in coal in 1834. Manufactured on a large scale after Perkin's discovery of mauve in 1856. _Anatta_, (Anotto, Arnotto, Roucou), 111. A dye obtained from the pulp surrounding the seeds of the _Bixa orellana_; chiefly used in dyeing silk an orange colour, but is of a fugitive nature. _Archil_, 52, 53, 54. _Argol_, 131. The tartar deposited from wines completely fermented, and adhering to the sides of casks as a hard crust. When purified it becomes Cream of Tartar. _Ash_, 41, 120. _Astringents_, 19, 26. B.--_Barberry_, 41, 120. _Barwood_, 67, 106. _Beck._--A large vessel or tub used in dyeing. _Bichromate of Potash_, 32. _Birch_, 38, 42, 43, 99, 103. _Black_, 122-123; from logwood, 79-85. _Black Dye Plants_, 44. _Blue_, 63; from Indigo, 66-75; from lichen, 61; from logwood, 79-85. _Blue black_, 81. _Blue Dye Plants_, 39. _Blue stone_, 33. _Blue vitriol_, 33-36. _Bois de Campêche_, 77. _Bois jaune_, Fustic, yellow wood. _Brazil woods_, 106. _British Dye Plants_, 37-44. _Broom_, 41, 134. _Brown_, 122-133; from lichens, 45-49, 51, 56, 57, 60-62, 140; from madder, 102, 106; from weld, 112; from woad, 76. _Brown Dye Plants_, 43. _Buff_, 115. C.--_Campeachy Wood_, 77. _Camwood_, 106, 131. _Carthamus._ Safflower, an annual plant cultivated in S. Europe, Egypt and Asia for the red dye from its flowers. _Catechu_, 33, 35, 36, 122-6. _Caustic Soda._ Carbonate of soda, boiled with lime. _Chestnut_, 35. _Chrome_, 32, 33. _Cinnamon_, 102. _Claret_, 51, 84. _Coal Tar Colours._ Colours obtained by distillation and chemical treatment from coal tar, a product of coal during the making of gas. There are over 2,000 colours in use. _Cochineal_, 92-7, 132. _Copper_, 33-5. _Copper sulphate_, 33. _Copperas_, 29, 30, 129. _Corcur_, 51. _Cotton_, 18; the dyeing of, 19; without mordant, 21; method in India, 19, 20; the mordanting of, 26. _Cream_, from catechu, 124. _Cream of Tartar_, 28-32, 34. See argol. _Crimson_, 94-96, 106; from lichens, 49, 60. _Crottle_, 46, 56-60, 62. _Cudbear_, 45, 52, 54, 55, 57, 58, 67, 85, 129. D.--_Detergent_, 15. A cleansing agent. _Dip._ Generally applied to immersing cloth etc. in the blue vat. _Divi-divi_, 35, 36. The dried pods of _Cæsalpina coriaria_, growing in the West Indies and S. America. They contain 20 to 35% tannin and a brown colouring matter. _Dock_, 40, 44, 50, 69, 120, 135. _Drab_, 80, 118, 126. _Dyer's Broom_, 40, 121, 135. _Dyer's Spirit_, 32. Aqua fortis, 10 parts; Sal Ammoniac, 5 parts; Tin, 2 parts; dissolved together. _Dyer's Weed_, 40, 134. E.--_Enter._ To enter wool, to put it into the dye or mordant liquor. _Extract of Indigo_, 65-69. F.--_Felting_, to prevent, 15. _Fenugrec_, Fenugreek, 107. _Trigonnella fÅ�nugræcum._ _Ferrous sulphate_, 29. _Flavin._ A colouring matter extracted from quercitron. _Fleece_, various kinds of, 13. _Flesh colour_, 132. _Full, to._ To tread or beat cloth for the purpose of cleansing and thickening it. _Fuller's Herb._ _Saponaria officinalis._ A plant used in the process of fulling. _Fuller's Thistle_ or Teasle. _Dipsacus fullonum._ Used for fulling cloth. _Fustet._ Young fustic. Venetian Sumach. _Rhus cotinus._ It gives a fine orange colour, which has not much permanence. _Fustic_, 113-116, 130, 131, 135. G.--_Galls_, _Gall nuts_, 26, 129. Oak galls produced by the egg of an insect,--the female gall wasp. An excrescence is produced round the egg, & the insect, when developed, pierces a hole & escapes. Those gall nuts which are not pierced contain most tannic acid. The best come from Aleppo and Turkey. _Gramme_ or _Gram_. About 15½ grains (Troy). _Green_, 133-9; with fustic, 137-8; with weld, 139. _Green Dye Plants_, 42. _Green Vitriol_, 29. _Green wood_, 107, 108, 134. _Greening weed_, 121. _Grey_, 67, 79; from logwood, 80, 85. H.--_Hazel colour_, 128. _Heather_, 40, 85, 121, 135. I.--_Iceland moss_, 51, 61. _Indigo_, 63-75, 135-139. _Indigo Extract_, 64-70; for green, 135-139. _Iron_, 29-30. K.--_Kermes_, 87-91. _Kilo. Kilogramme._ Equals 2 lbs. 3·2 oz. _Korkalett_, 50. L.--_Lac_, 97, 98. _Larch_, 43, 131, 137. _Lavender_, 84. _Lesser Dye_, 77, 79. _Ley_, see lye. _Lichen_, 45-62, 140. _Lilac_, 95, 96, 97. _Lima Wood_, 106, 107. _Linen_, 21; to bleach, 22; the mordanting of, 26; various kinds of, 21. _Litre_, 80. Nearly 1¾ pints. _Lixiviation._ The process of separating a soluble substance from an insoluble by the percolation of water. _Lixivium._ (Lye). A term often used in old dye books. Water impregnated with alkaline salts extracted by lixiviation from wood ashes. _Logwood_, 77, 130, 131, 137. _Lye_ or _Ley_. Any strong alkaline solution, especially one used for the purpose of washing, such as soda lye, soap lye. M.--_Madder_, 38, 98-105, 132. _Magenta_, 44. _Maize_, 132. _Mercerised Cotton._ Cotton prepared by treating with a solution of caustic potash or soda or certain other chemicals. Discovered by John Mercer in 1844. _Milling._ The operation of fulling cloth. _Mordants_, 24; general remarks on, 34; primitive mordants, 25. _Muriate of Tin_, 31. _Myrobalans_, 26, 35, 36. The fruit of several species of trees, growing in China & the East Indies, containing tannic acid, (25-40% tannin). O.--_Oak bark_, 128. _Oak galls_, 35, 36. _Oil of Vitriol_, 64, 65, 67. Sulphuric acid. _Old Fustic_, see Fustic. _Old Gold_, 109, 112-114. _Olive_, 109, 113, 118, 135. _Onion skins_, 128. _Orange_, 91, 93, 102, 106, 109, 120, 132; from lichens, 48, 51, 58, 60-2. _Orchil_, 45, 52-55. _Organzine._ Twisted raw silk from best cocoons, used for warp. _Orseille_, 58. _Oxalic Acid_, 30, 31. P.--_Pastel_, 77. Woad. _Peach_, 120. _Peach wood_, 106-107. _Pear_, 41, 120. _Pearl ash._ Carbonate of Potash. _Peat Soot_, 128. _Persian Berries._ The dried unripe fruit of various species of Rhamnus. Also called French berries, Grains of Avignon. _Philamort_, 48. _Pink_, 93; from lichen, 57. _Plum colour_, from lichen, 48. _Poplar_, 42, 135. _Potassium Carbonate._ (Potashes). Carbonate of Potash has been known since ancient times as a constituent of the ashes of land plants, from which it is obtained by extraction with water. In most cases Sodium Carbonate, which it strongly resembles, can be used in its place. _Potassium dichromate_, 32. _Privet_, 39, 41, 42, 121. _Purple_, from lichens, 53, 57-60, 62; with cochineal, 95, 96; with logwood, 82, 85, 86, 87. _Purple Dye Plants_, 43. Q.--_Quercitron_, 116-120; for green, 135-137. R.--_Red_, 87-107; from lichens, 48-51, 53, 56, 58, 60. _Red Dye Plants_, 38. _Red Spirits._ Tin spirits. Applied to tin mordants generally. A solution of Stannous chloride. _Red woods._ Camwood, Barwood, Sanderswood (Santal, Sandal, Red Sanders), Brazil wood, Sapan wood, Peach wood. _Retting_, 21. _Roucou._ Anatta, Arnotto. S.--_Sandalwood_ or Saunderswood, 106. _Sadden, to_, _saddening_, 14, 30, 34, 127, 130, 132. To darken or dull in colour. _Sapan wood_, 106. _Savory_, 107, 108. _Sawwort_, 41, 135. _Saxon blue_, 67, 70, 136. The dye made by Indigo dissolved in oil of vitriol. _Saxon green_, 118, 136, 138. _Scarlet_, 88, 91, 92, 93, 94, 95, 97, 98. _Scarlet of Grain_, 87. _Scotch ell._ 37·2 inches. _Scour, to._ To wash. _Scroop._ The rustling property of silk. _Scrottyie_, 49, 50, 59. _Silk_, 16-18; to alum, 18; general method of dyeing, 17; to mordant, 26; the preparation of, 17; to soften, 18; various kinds of, 16; raw, 16, 17; waste, 16. _Silver drab_, 84. _Sloe_, 39. _Soda ash._ Carbonate of soda. _Soda ley_, 101. _Sour water_, 28. To every gallon of water, add 1 gill vitriol; stir thoroughly. Stuff steeped in this should be covered with the liquor, otherwise it will rot. (2). Water in which bran has been made to grow sour. 24 bushels of bran are put in a tub, about 10 hogsheads of nearly boiling water is poured into it; acid fermentation soon begins, and in 24 hours it is ready to use. (3). Throw some handfuls of bran into hot water and let it stand for 24 hours, or till the water becomes sour, when it is fit for use. _Stannous Chloride_, 31. _Staple_, 11, 12. A term applied to cotton and wool, indicating length of fibre. _Stuffing and Saddening_, 14, 30. _Substantive Dye_, 24, 52, 65, 116. A dye not requiring a mordant. _Sulphuric Acid_, 64, 66, 67, 70, 120, 131. _Sumach_, 26, 35, 36, 126. Leaves and twigs of several species of Rhus, containing Tannic acid. It is sold in the form of crushed leaves or as a powder, (15-20% tannin). T.--_Tannic Acid_, 26, 35. _Tannin_, 35, 36. _Tin_, 31, 32. _Tin crystals_, 31. _Tin salts_, 31. _Tram._ Slightly twisted raw silk, used for weft. _Turkey Red_, 99. _Turmeric_, 116. _Turquoise_, 69. _Tyrian purple._ A purple colour obtained from certain shell fish, such as Buccinum & Purpura. It is mentioned by Pliny as being discovered in 1400 B.C. It was a lost art in the middle ages. V.--_Valonia_, 35. Acorn cups of certain species of oak from S. Europe, containing 25-35% of tannic acid. _Vegetable alkali._ Potash. _Verdigris_, 33. Acetate of copper. _Violet_, 86, 94, 103. _Vitrum_, 76. W.--_Walnut_, 43, 127, 132. _Water_ for dyeing, 23. _Weld_, 107-112, 120, 130, 134, 135. _Wet out_, to. To damp, before putting the yarn or cloth into the dye. _Woad_, 39, 75-77. _Wool_, 11; to bleach, 16; to cleanse, 15, 16; long staple wool, 12; various kinds of, 11, 12, 13. _Wool Dyeing_, general methods, 13-16. Y.--_Yarn_, to soften, 16. _Yellow_, 107-122; from lichens, 51, 57, 140; from sumach, 126. _Yellow Dye Plants_, 39. _Yellow Weed_, 134. _Yellow Wood_, 107. ERRATA page 59. Rock Urcolaria shld. be Rock Urceolaria. page 61. Flowering lusnea shld. be Flowering Usnea. page 144. (printed without being corrected). Add:--_Alder bark_, 43, 44, 100, 126. _Almond_, 120. _Amber_, 132. _Argol_, 131. _Ash_, 41, 120. _Barwood_, 67, 106. Correct:-- authracene to anthracene _anie_ to _añil_ Roucon to Roucou sorrounding to surrounding _Printed by Douglas Pepler at Ditchling_ [Illustration: A WOOD CUT ILLUSTRATION FROM THE DEVIL'S DEVICES (_see advert_.)] BOOKS Published by DOUGLAS PEPLER AT THE HAMPSHIRE HOUSE WORKSHOPS HAMMERSMITH COTTAGE ECONOMY BY WILLIAM COBBETT with an INTRODUCTION BY G. K. CHESTERSON Price 2s. 6d. net (Postage 3d.) A REPRINT of a STANDARD WORK Which should be of use, in these days, to Many beside Cottagers. A CAROL AND OTHER RHYMES By EDWARD JOHNSTON Price 1s. net. (Postage 2d.) A BOOK ON VEGETABLE DYES By ETHEL M. MAIRET Price 5s. net (Postage 4d.) THE DEVIL'S DEVICES or Control versus Service by DOUGLAS PEPLER, with Wood-cut Illustrations by Eric Gill. Price 2s. 6d. net. The first 200 copies will be numbered and signed. Price 3s. 6d. net. This book contains an account of a cinematograph entertainment in Satan's Circuit; a crafty devil; and an appreciation of No. 27, an English working-man. _THE REVIEWERS ON THE DEVIL'S DEVICES._ WHAT WILL THEY SAY NEXT? But we believe that the effect upon most people will be what it certainly is upon one reader, who is NOT IN THE LEAST SHOCKED, but is considerably BORED. --_C. O. Review._ A verse may find him who a sermon flies, and there is likely to be here and there one, who seeing in a bookseller's window the red cover and the black, the very black, cart thereon, will incontinently purchase. --_The New Witness._ His arguments are closely logical when he chooses to make them so, though their sequence and arrangement are bewilderingly haphazard. --_The Herald._ The whole effect is of a hotch-potch composed in a lunatic asylum; and the pictures seem madder than the letterpress.... Much to the irritation of my wife, for supper was waiting, I read on till I had read the book right through.... The "mad" author of this book is Douglas Pepler, the "mad" artist is Eric Gill. When I say "mad" I am, for the moment, taking it for granted that the world is sane.-- _Labour Leader._ * * * * * (and so on very nicely for several columns.)-- _Land and Water._ The drama is skilfully unfolded (though the author fails over the spelling of Nietzsche, page 29) and interspersed with wood-cuts ... and a still more excellent account of the passing of the poor man's parlour. _The Cambridge Magazine._ The author has marked with the toe of his boot the moral weakness on which the Devil depends for his power over the modern world.-- _Red Feather._ Mr. Pepler perpetually _DROPS_ into dialogue with FATAL RESULTS. _New Age._ 
46377	----	A PRACTICAL HANDBOOK ON THE DISTILLATION OF ALCOHOL FROM FARM PRODUCTS INCLUDING The Processes of Malting; Mashing and Mascerating; Fermenting and Distilling Alcohol from Grain, Beets, Potatoes, Molasses, etc., with Chapters on Alcoholometry and the DE-NATURING OF ALCOHOL FOR USE IN Farm Engines, Automobiles, Launch Motors, and in Heating and Lighting; with a Synopsis of the New Free Alcohol Law and its Amendment and the Government Regulations. BY F. B. WRIGHT. SECOND EDITION, REVISED AND GREATLY ENLARGED NEW YORK SPON & CHAMBERLAIN, 123 LIBERTY STREET LONDON E. & F. N. SPON, LIMITED, 57 HAYMARKET, S.W. 1907 Copyright, 1906, By SPON & CHAMBERLAIN. Copyright, 1907, By SPON & CHAMBERLAIN. McIlroy & Emmet, Printers, 22 Thames St., New York, U. S. A. PREFACE TO SECOND EDITION. Since the passage of the "Free Alcohol Act" there has been a constantly increasing demand for information as to the manufacture of industrial alcohol. This, with the favorable reception accorded to the first edition of this book has lead the publishers to bring out a second edition. The entire volume has been carefully revised and not only has the original text been amplified but new chapters have been added explaining the most modern and approved methods and appliances both as used in Europe and in this country. Another valuable feature of the present volume is the collection of U. S. de-naturing formulas covering the special denaturants necessitated by the various arts and by the Government requirements. The chapters on modern distilling apparatus rectifiers and modern plants have been very carefully prepared in order to give the reader a clear idea of the various types of apparatus in use to-day and of their general place in a distillery system. The value of the book has been further increased by numerous additional illustrations. It would be impossible in the compass of one small volume to describe all the practical details of alcohol manufacture particularly as these details vary with every distillery, but it has been the aim of the author to give sufficient information to enable every reader to understand the theory and general practice of the art, leading him from the simple methods and apparatus used until the last ten years to the more complicated stills and processes which have been lately devised. Inasmuch as the manufacture of industrial alcohol has been most highly perfected in France and Germany, use has been made of the best European authorities and in particular the author begs to acknowledge his indebtedness to Sa Majeste L'Alcohol by L. Beaudry de Saunier. The publishers' and author's acknowledgements are also due to the Vulcan Copper Works Company of Cincinnati, Ohio, and to the Geo. L. Squier Manufacturing Company, Buffalo, New York, for their kindness in allowing illustrations to be given of modern American distilling apparatus. F. B. WRIGHT. New York, Aug. 1, 1907. PREFACE. To the majority of persons Alcohol connotes liquor. That it is used to some extent in the arts, that it is a fuel, is also common knowledge, but Alcohol as a source of power, as a substitute for gasoline, petroleum, and kindred hydrocarbons was hardly known to the generality of Americans until the passage of the "De-naturing Act" by the last Congress. Then Alcohol leaped at once into fame,--not merely as the humble servant of the pocket lamp, nor as the Demon Rum, but as a substitute for all the various forms of cheap hydrocarbon fuels, and as a new farm product, a new means for turning the farmer's grain, fruit, potatoes, etc., into that greatest of all Powers, _Money_. That Alcohol was capable of this work was no new discovery accomplished by the fiat of Congress, but the Act of June 7, 1906, freed de-natured Alcohol from the disability it had previously labored under,--namely, the high internal revenue tax, and so cheapened its cost that it could be economically used for purposes in the arts and manufactures which the former tax forbade. This Act then opens the door of a new market to the farmer and the manufacturer, and it is in answer to the increased desire for information as to the source of Alcohol and its preparation that this book has been written. The processes described are thoroughly reliable and are such as have the approval of experience. As was stated above, Alcohol is not a natural product, but is formed by the decomposition of sugar or glucose through fermentation. This leaves Alcohol mixed with water, and these in turn are separated by distillation. The literature treating of the distillation of Alcohol from farm products is very scant. But due credit is here given to the following foreign works which have been referred to: Spon's Encyclopædia of the Industrial Arts, which also contains an article on Wood Alcohol, Mr. Bayley's excellent Pocketbook for Chemists, and Mr. Noel Deerr's fine work on Sugar and Sugar Cane. NEW YORK, Oct. 31, 1906 CONTENTS. CHAPTER I. ALCOHOL, ITS VARIOUS FORMS AND SOURCES. Its chemical structure. How produced. Boiling points. Alcohol and water. Alcohol, where found. Produced from decomposition of vegetables. Sources. Principal alcohols. 1 CHAPTER II. THE PREPARATION OF MASHES, AND FERMENTATION. A synopsis of steps. Mashing starchy materials. Gelatinizing apparatus and processes. Saccharifying. Cooling the mash. Fermentation. Yeast and its preparation. Varieties of fermentation:--Alcoholic, acetous, lactic and viscous. Fermenting periods. Fermenting apparatus and rooms. Strengthening alcoholic liquors. 8 CHAPTER III. DISTILLING APPARATUS. The simple still. Adams still. Concentrating stills. Compound distillation. Dorn's still. Continuous distillation. The Cellier-Blumenthal still. Coffey's still. Current stills. Regulating distillery fire. 33 CHAPTER IV. MODERN DISTILLING APPARATUS. The principles of modern compound stills. Vapor traps and their construction. Steam regulation. Feed regulation. American apparatus. The Guillaume inclined column still. 66 CHAPTER V. RECTIFICATION. General principles of "fractionation." Old form of rectifying still. Simple fractionating apparatus. "Vulcan" rectifier. Barbet's twin column rectifier. Guillaume's "Agricultural" rectifying apparatus. Rectifying by filtration. 82 CHAPTER VI. MALTING. The best barley to use. Washing. Steeping. Germinating. The "wet couch." The "floors." "Long malt." Drying. Grinding and crushing. 103 CHAPTER VII. ALCOHOL FROM POTATOES. Washing. Gelatinizing and saccharifying. Low pressure steaming, and apparatus therefor. Crushing the potatoes. High pressure steaming and apparatus. The vacuum cooker. The Henze steamer. Isolation of starch without steam. English methods. Saccharifying the starch. 110 CHAPTER VIII. ALCOHOL FROM GRAIN, CORN, WHEAT, RICE, AND OTHER CEREALS. Relative yields of various cereals. Choice of grain. Proportions of starch, etc., in various grains. Grinding. Steeping. Preparatory mashing. Saccharifying. Treatment of grain under high pressure. Softening grain by acid. 126 CHAPTER IX. ALCOHOL FROM BEETS. Beet cultivation. Composition. Soil and manures. Sowing. Harvesting. Storing. Production of alcohol from beets. Cleaning and rasping. Extraction by pressure. Extraction by maceration and diffusion. The diffusion battery. Fermentation. Direct distillation of roots. 140 CHAPTER X. ALCOHOL FROM MOLASSES AND SUGAR CANE. The necessary qualities in molasses. Beet sugar. Molasses mixing and diluting. Neutralizing the wash. Pitching temperature. Distilling. Fermenting raw sugar. Cane sugar molasses. "Dunder." Clarifying. Fermenting. Various processes. 163 CHAPTER XI. ALCOHOLOMETRY. Hydrometers in general. Proof spirit. Syke's hydrometer. Gay-Lussac's hydrometer. Tralles alcoholometer. Hydrometric methods. Estimation of alcohol. Field's alcoholometer. Grisler's method and apparatus. Estimating sugar in mash. Determination of alcoholic fruits. Physical tests. Chemical tests. The Permanganate of Potash test. Results by Barbet. 174 CHAPTER XII. DISTILLING PLANTS, THEIR GENERAL ARRANGEMENT AND EQUIPMENT. Simple apparatus. Elaborate plants. Steam stills. The fermenting room. Ventilation. Fermenting vats. Preparatory vats. Arrangement of grain distillery. A small beet distillery. Large beet distilling plant. Transporting beets. Potato distillery. Molasses distillery. Fermenting house for molasses. Transportation of molasses to distillery. Coal consumption. 189 CHAPTER XIII. DE-NATURED ALCOHOL, AND DE-NATURING FORMULÆ. Uses of alcohol. De-natured spirit:--Its use in Germany, France and England. The "De-naturing Act." The uses of de-natured alcohol. Methods and Formulæ for de-naturing. De-natured alcohol in the industrial world. 211 CHAPTER XIV. DE-NATURING REGULATIONS IN THE UNITED STATES. The Free Alcohol Act of 1906, and proposed changes therein. The Amendment of 1907. Internal Revenue Regulations. 224 Index. 261 LIST OF ILLUSTRATIONS No. PAGE. 1 Vacuum mash cooker _to face_ 10 2 Henze steamer 12 3 Mash cooler, air system 15 4 Mash cooler, water system 17 5 Yeasting and fermenting apparatus _to face_ 22 6 A simple still 34 7 Simple direct-heated still 35 8 Simple still, with rectifier 37 9 Adam's still 39 10 Corty's simplified distilling apparatus 41 11 Double still 42 12 Dorn's compound still 43 13 Compound still 46 14 Compound direct-fire still 47 15 Cellier-Blumenthal still 49 16 Details of rectifier column 50 17 Details of condenser and mash heater 52 18 Coffey's rectifying still 55 19, 20 Rotary current still 59, 60 21 Indicator for regulating the distilling fire 61 22 Diagrammatic view of column still and accessory apparatus _to face_ 64 23 Distilling plate 64 24, 25 Barbet traps 68 26 Steam regulator 70 27 Gauge glass for regulator 72 28 Continuous distilling apparatus with external tubular condenser _to face_ 72 29 Detail of chamber, continuous still 73 30, 31 Details of perforated plate _A_ 75, 76 32 Continuous distilling apparatus with goose separator _to face_ 76 33 Section of Gillaume's inclined column still 78 34 Gillaume's inclined column still 79 35 Rectifying still 88 36 Section of rectifying still 89 37 Fractional distilling apparatus 91 38 Rectifying apparatus with external tubular condenser _to face_ 94 39 Twin column Barbet rectifier 95 40 Gillaume's rectifier and inclined still 97 41 Steaming vat for potatoes 112 42 Bottom of steaming vat 113 43 Steam generator 114 44 Potato steamer and crusher 116 45 Bohn's steamer and crusher 118 46 Stack for storing beets 148 47 Storage cellar for beets 149 48 Beet and potato rasp 152 49 Dujardin's roll press 155 50 Defusion battery 158 51 Mixing vat 165 52 Syke's hydrometer 176 53 Field's alcoholometer 182 54 Geisler's apparatus 184 55 Continuous grain alcohol distillery--Barbet's system 198 56 Grain distillery, capacity 2500 bushels per day _to face_ 198 57 Small beet distillery 200 58 Large beet distillery 202 59 Molasses distillery, capacity 2500 gallons per day _to face_ 206 60 Molasses fermenting house 207 CHAPTER I. ALCOHOL, ITS VARIOUS FORMS AND SOURCES. =Alcohol.= (Fr., _alcool_; Ger., _alkohol_.) Formula, C_{2}H_{6}O. Pure alcohol is a liquid substance, composed of carbon, hydrogen, and oxygen, in the following proportions: C 52.17 H 13.04 O 34.79 ------ 100.00 It is the most important member of an important series of organic compounds, all of which resemble each other closely, and possess many analogous properties. They are classed by the chemist under the generic title of "Alcohols." Alcohol does not occur in nature; it is the product of the decomposition of sugar, or, more properly, of _glucose_, which, under the influence of certain organic, nitrogenous substances, called _ferments_ is split up into alcohol and carbonic anhydride. The latter is evolved in the form of gas, alcohol remaining behind mixed with water, from which it is separated by distillation. The necessary purification is effected in a variety of ways. TABLE I.--THE BOILING POINTS OF ALCOHOLIC LIQUORS OF DIFFERENT STRENGTHS, AND THE PROPORTIONS OF ALCOHOL IN THE VAPORS GIVEN OFF. ===========+===========+===========+===========+===========+=========== Proportion| |Proportion |Proportion | |Proportion of alcohol|Temperature|of alcohol |of alcohol |Temperature|of alcohol in the | of the |in the | in the | of the | in the boiling | boiling |condensed | boiling | boiling |condensed liquid in | liquid. |vapor in | liquid in | liquid. | vapor in 100 vols. | |100 vols. | 100 vols. | | 100 vols. -----------+-----------+-----------+-----------+-----------+----------- 92 | 171.0 F. | 93 | 20 | 189.5 F. | 71 90 | 171.5 F. | 92 | 18 | 191.6 F. | 68 85 | 172.0 F. | 91.5 | 15 | 194.0 F. | 66 80 | 172.7 F. | 90.5 | 12 | 196.1 F. | 61 75 | 173.6 F. | 90 | 10 | 198.5 F. | 55 70 | 175.0 F. | 89 | 7 | 200.6 F. | 50 65 | 176.0 F. | 87 | 5 | 203.0 F. | 42 50 | 178.1 F. | 85 | 3 | 205.1 F. | 36 40 | 180.5 F. | 82 | 2 | 207.5 F. | 28 35 | 182.6 F. | 80 | 1 | 209.9 F. | 13 30 | 185.0 F. | 78 | 0 | 212.0 F. | 0 25 | 187.1 F. | 76 | | | ===========+===========+===========+===========+===========+=========== Pure, absolute alcohol is a colorless, mobile, very volatile liquid, having a hot, burning taste, and a pungent and somewhat agreeable odor. It is very inflammable, burning in the air with a bluish-yellow flame, evolving much heat, leaving no residue, and forming vapors of carbonic anhydride and water. Its specific gravity at 0° C (32° F.) is .8095, and at 15.5° C. (60° F.) .794; that of its vapor is 1.613. It boils at 78.4° C. (173° F.). The boiling point of its aqueous mixtures are raised in proportion to the quantity of water present. Mixtures of alcohol and water when boiled give off at first a vapor rich in alcohol, and containing but little aqueous vapor; if the ebullition be continued a point is ultimately reached when all the alcohol has been driven off and nothing but pure water remains. Thus, by repeated distillations alcohol may be obtained from its mixtures with water in an almost anhydrous state. Absolute alcohol has a strong affinity for water. It absorbes moisture from the air rapidly, and thereby becomes gradually weaker; it should therefore be kept in tightly-stoppered bottles. When brought into contact with animal tissues, it deprives them of the water necessary for their constitution, and acts in this way as an energetic poison. Considerable heat is disengaged when alcohol and water are brought together; if, however, ice be substituted for water, heat is absorbed, owing to the immediate and rapid conversion of the ice into the liquid state. When one part of snow is mixed with two parts of alcohol, a temperature as low as 5.8° F. below zero is reached. When alcohol and water are mixed together the resulting liquid occupies, after agitation, a less volume than the sum of the two original liquids. This contraction is greatest when the mixture is made in the proportion of 52.3 volumes of alcohol and 47.7 volumes of water, the result being, instead of 100 volumes, 96.35. A careful examination of the liquid when it is being agitated reveals a vast number of minute air-bubbles, which are discharged from every point of the mixture. This is due to the fact that gases which are held in solution by the alcohol and water separately are less soluble when the two are brought together; and the contraction described above is the natural result of the disengagement of such dissolved gases. The following table represents the contraction undergone by different mixtures of absolute alcohol and water. TABLE II.--100 VOLUMES OF MIXTURE AT 59° F. ========+============++========+============++========+============ Alcohol.|Contraction.||Alcohol.|Contraction.||Alcohol.|Contraction. --------+------------++--------+------------++--------+------------ 100 | 0.00 || 65 | 3.61 || 30 | 2.72 95 | 1.18 || 60 | 3.73 || 25 | 2.24 90 | 1.94 || 55 | 3.77 || 20 | 1.72 85 | 2.47 || 50 | 3.74 || 15 | 1.20 80 | 2.87 || 45 | 3.64 || 10 | 0.72 75 | 3.19 || 40 | 3.44 || 5 | 0.31 70 | 3.44 || 35 | 3.14 || | ========+============++========+============++========+============ Alcohol is termed "absolute" when it has been deprived of every trace of water, and when its composition is exactly expressed by its chemical formula. To obtain it in this state it must be subjected to a series of delicate operations in the laboratory, which it would be impossible to perform on an industrial scale. In commerce it is known only in a state of greater or less dilution. Alcohol possesses the power of dissolving a large number of substances insoluble in water and acids, such as many inorganic salts, phosphorus, sulphur, iodine, resins, essential oils, fats, coloring matters, etc. It precipitates albumen, gelatine, starch, gum, and other substances from their solutions. These properties render it an invaluable agent in the hands of the chemist. Alcohol is found in, and may be obtained from, all substances--vegetable or other--which contain sugar. As stated above, it does not exist in these in the natural state, but is the product of the decomposition by fermentation of the saccharine principle contained therein; this decomposition yields the spirit in a very dilute state, but it is readily separated from the water with which it is mixed by processes of distillation, which will subsequently be described. The amount of alcohol which may be obtained from the different unfermented substances which yield it varies considerably, depending entirely upon the quantity of sugar which they contain. Alcohol is produced either from raw materials containing starch, as potatoes, corn, barley, etc., or raw materials containing sugar, as grapes, beets, sugar-cane, etc. The following are some of the most important sources from which alcohol is obtained: Grapes, apricots, cherries, peaches, currents, gooseberries, raspberries, strawberries, figs, plums, bananas, and many tropical fruits, artichokes, potatoes, carrots, turnips, beet-root, sweet corn, rice and other grains. Sugar-cane refuse, sorgum, molasses, wood, paper, and by a new French process from acetylene. On a large scale alcohol is usually obtained from sugar beets, molasses or the starch contained in potatoes, corn and other grains. The starch is converted into maltose by mixing with an infusion of malt. The maltose is then fermented by yeast. Sulphuric acid may be used to convert even woody fibre, paper, linen, etc., into glucose, which may in turn be converted into alcohol. TABLE III.--PRINCIPAL ALCOHOLS. =================+=======================+==============+============== Chemical Name. | Source. | Formula. |Boiling Point °F. -----------------+-----------------------+--------------+-------------- 1 Methyl Alcohol|Distillation of Wood |CH_{3}OH | 150.8 2 Ethyl " |Fermentation of sugar |C_{2}H_{5}OH | 172.4 3 Propyl " | " " grapes |C_{3}H_{7}OH | 206.6 4 Butyl " | " " beets |C_{4}H_{9}OH | 242.6 5 Amyl " | " " potatoes|C_{5}H_{11}OH | 278.6 6 Caproyl " | " " grapes |C_{6}H_{13}OH | 314.6 7 Aenanthyl " |Distillation castor oil|C_{7}H_{15}OH | 347. | with potatoes | | 8 Capryl " |Essential oil hog weed |C_{8}H_{17}OH | 375.8 9 Nonyl " |Nonane from petroleum |C_{9}H_{19}OH | 10 Rutyl " |Oil of Rue |C_{10}H_{21}OH| 11 Cytyl " |Spermaceti |C_{16}H_{33}OH| 12 Ceryl " |Chinese wax |C_{26}H_{53}OH| 13 Melisyl " |Bees' wax |C_{30}H_{61}OH| =================+=======================+==============+============== Among a variety of other substances which have been and are still used for the production of alcohol in smaller quantities, are roots of many kinds, such as those of asphodel, madder, etc. Seeds and nuts have been made to yield it. It will thus be seen that the sources of this substance are practically innumerable; anything, in fact, which contains or can be converted into sugar is what is termed "alcoholisable." Alcohol has become a substance of such prime necessity in the arts and manufactures, and in one form or another enter so largely into the composition of the common beverages consumed by all classes of people that its manufacture must, of necessity, rank among the most important industries of this and other lands. Of the alcohols given in the above table only two concern the ordinary distiller, or producer of alcohol for general use in the arts. Methyl alcohol, the ordinary "wood alcohol," or wood naphtha, and Ethyl alcohol, which is produced by the fermentation of sugar and may therefore be made from anything which contains sugar. Ethyl alcohol forms the subject of this treatise. Aside from its chemical use in the arts as a source of energy and as a fuel, alcohol will likely soon compete with petroleum, gasoline, kerosene, etc., under the Act of Congress freeing the "de-naturized" spirit from the Internal Revenue tax. This act and the de-naturing process are covered in the last chapters of this book. CHAPTER II. THE PREPARATION OF MASHES, AND FERMENTATION. Alcohol may be produced either from, (1) farinacious materials, such as potatoes or grains, (2), from sacchariferous substances such as grapes, sugar beets, sugar cane, or the molasses produced in sugar manufacture. THE PREPARATION OF STARCHY MATERIALS. =Saccharification.= =Preparatory Mashing.= With starchy materials it is first necessary to convert the starch into a sugar from which alcohol can be produced by the process of fermentation. This is called saccharification. =Gelatinizing.= The first step in this process is gelatinizing the starch;--that is, forming it into a paste by heating it with water, or into a liquid mass by steaming it under high pressure. The liquid or semi-liquid mass is then run into a preparatory mash vat and cooled. =Saccharifying.= The disintegrated raw materials or gelatinized starch in the preparatory mash vat is now to be "saccharified" or converted into sugar. This is effected by allowing malt to act on the starch. This malt contains a certain chemical "ferment" or enzyme, called "diastase" ("I separate"). This is able under proper conditions to break up the gelatinized starch into simpler substances--the dextrins--and later into a fermentable sugar called maltose. =Fermentation.=--The maltose or sugar in the "mash" is now to be converted into alcohol. This is accomplished by fermentation, a process of decomposition which converts the sugar into carbonic acid and alcohol. Fermentation is started by yeast, a fungus growth, which in the course of its life history produces a matter called zymose which chemically acts on the sugar to split it up into carbonic acid gas and alcohol. Yeast may be either "wild" or cultivated. If the mash is left to stand under proper condition the wild yeast spores in the air, will soon settle in the mash and begin to multiply. This method of fermentation is bad because other organisms than yeast will also be developed,--organisms antagonistic to proper fermentation. As a consequence, pure or cultivated yeast is alone used. This yeast is cultivated from a mother bed in a special yeast mash and when ripened is mixed with the mash in the fermenting vat. At a temperature between 50° F. and 86° F. the yeast induces fermentation, converting the sugar of the mash into carbon dioxid which escapes, and alcohol which remains in the decomposed mash, or "beer" as it is termed in the United States. It now remains to separate the alcohol from the water of the beer with which it is mixed. This is accomplished by distillation and rectification, as will be fully described in the chapters following. PRODUCTION OF ALCOHOL FROM SACCHARIFEROUS SUBSTANCES. Substances such as grape juice, fruit juice, sugar beets, cane sugar and molasses already contain fermentable sugar. Saccharification is therefore not needed and juices or liquids from these matters are either directly fermented as in the case of sugar cane, or--as in the case of sugar beets--the sugar in juice is transferred by yeast into a fermentable sugar. MASHING STARCHY MATERIALS. We will now consider in more detail the preparation of mashes from starch-containing substances. =Gelatinizing Apparatus.= These comprise either ordinary vats, into which steam at low pressure is admitted (see Fig. 44), cookers and stirrers such as shown in Fig. 1 and 45 or the Henze steamer (Fig. 2.) [Illustration: FIG. 1.--Vacuum Mash Cooker. (_To face page 10_)] An example of a cooking and mashing apparatus and its connections is shown in Fig. 1. This is the vacuum cooker put on the market by the Vulcan Copper Works Company, of Cincinnati, Ohio. This consists of a cylindrical steel vessel the interior of which is fitted with stirrer arms attached to a shaft making about sixty revolutions per minute. The steam enters the vessel at the bottom by means of pipes conducting it from a manifold, or header, in the same manner as is shown in the apparatus illustrated in Fig. 45. Attached to each pipe at its point of entrance is a check valve to spray the steam through the mash. A thermometer for registering the temperature and a water gauge are placed in the manifold. The grain enters the cooker from the grain hopper by way of a spout. The cylinder has been previously supplied with hot water and during the mixing of the meal with the hot water the mass is constantly stirred. The malt is mixed with water in the small grain tub which is provided with a stirrer. The malt mash is admitted into the cooker and the mass thoroughly mixed by the arms. After the mashing, the product passes off to the drop tub and from thence to the mash coolers where it is cooled to the proper temperature for fermentation. The gearing for agitating the malt mash and the grain or potato mash is evident from the drawing. The pressure steamers used in mashing are shown in Fig. 2. They comprise a cylindrical vessel preferably conical or partly conical, provided with steam entrance pipes, air valves and a manhole. At the bottom of the cone forming the lower end of the steamer is a grating located in an exit pipe provided with a valve. One of the steam entrance pipes is so located that the steam is forced in at the top of the cylinder while the other allows steam to enter at the bottom of the cylinder. The device is provided with a pressure gauge and an air cock. [Illustration: FIG. 2.--Henze Steamer.] In use the body of the apparatus is partly filled with water and the material to be treated. This is acted upon by a steam pressure of two atmospheres, which is later increased to three, steam entering by the lowermost pipe, passing up through the water and potatoes thoroughly agitating the same and passing away by the steam gauge. After standing at the last pressure for ten or fifteen minutes the lower steam inlet is closed; the upper inlet and the blow-out valve are opened. The steam is then increased to its highest point or about four atmospheres and the lower valve is opened. The disintegrated material is forced out by the steam through the grating at the bottom of the cone. This comminutes it and pulps it before it passes into the preparatory mash tub. Blowing out requires about 40 to 50 minutes. Steaming and blowing out together cover a space of two hours. The pressure of the steam before blowing out should be such that the steam is constantly being blown off through the safety valve. Thus the mass in the steamer is agitated and the material entirely disintegrated and gelatinized. =Process.= Into these apparatuses the potatoes and corn or grain first ground into mash, or even corn or grain unground, if the pressure is high enough, are disintegrated and cooked by steam under high pressure. During this process the starch becomes partially dissolved and partially gelatinized, which occurs when a pressure of some 65 pounds has been attained, with a temperature of about 300° F. =Saccharifying.= It is now necessary to saccharify the gelatinized mass. This is accomplished by adding to it a certain amount of malt, whereby maltose or sugar is formed through the action of the diastase. The amount of maltose so created is in proportion to the amount of malt used, the length of time it is acting, the dilution of the mash, and the existence of a proper temperature. The temperature best fitted for this action lies above 122° F., but in order to entirely dissolve the starch a temperature of 145° F. should be used. In addition, at this higher temperature, the bacteria inimical to fermentation are destroyed. A higher temperature than 145° F. should not be allowed, except in extraordinary cases as it injures the effectiveness of the diastase. =Apparatus.= The mixture of the malt with the mash may either take place in the heater and cooker itself (see Fig. 2) or in a preparatory mash vat. In the first instance, the malt is allowed to enter the cooking cylinder when the temperature of the mash is about 145° F. The mash is stirred until thoroughly mixed when the product is drawn into a receptacle called a drop tub and later reduced to a proper fermenting temperature. When the Henze type of steamer is used, the pulped mass (see Page 121) is blown into a preparatory mash vat, at the proper temperature. It is left to stand at this temperature for a period varying from twenty minutes to an hour and a half. =Cooling the Mash.= Saccharification takes place at a temperature above 122° F., but the proper fermenting temperature is only about 63° F. to 68° F., and hence some means must be adopted for cooling the hot mash to this temperature and for so cooling it in a relatively short time. [Illustration: FIG. 3.--Mash Cooler, Air System.] =Cooling= may be accomplished by submitting the mash to currents of air; to contact with cold water coils or by the use of ice. One of the simplest coolers of the first class is shown in Fig. 3. This consists of a shallow panlike tank A having means for introducing and drawing off the mash. Rotating in the center of the tank is a vertical shaft _C_ carrying radiating stirrer arms _B_. Braces _M_ extend to the middle of these arms and the arms carry a number of blades or paddles _b_, which extend down into the mash. Above the arms, mounted loosely on the same shaft, but rotating in the opposite direction, are fans _H_ supported by arms _J_ which create air currents over the agitated mash. These fans move at a much faster rate than the stirrers _B_. A simple form of driving gear is shown. The main shaft _C_ is rotated by a large bevel gear _D_, meshing with a small pinion _E_ on the end of a driving shaft _F_, which is driven by a belt. This shaft also carries a bevel gear _L_, which meshes with a bevel gear _K_ mounted on a sleeve. This sleeve surrounds and rotates freely on the central shaft _C_, being supported at its lower end in ball bearings _m m_, mounted on the shaft. This combination gives opposite rotation to the faces and stirrer arms and at different speeds. The driving mechanism can be of course varied. Another simple method of air cooling would be to let the mash run down a series of enclosed steps or chutes, the casing being kept cool by an air blast. Mashes may be even cooled by mere stirring by paddles, but this takes a long time and much labor. The preparatory mash vats used to-day are almost all provided with stirrers formed of hollow blades capable of a rapid stirring movement through the mash. Through the hollow blades cold water is forced. Mash vats of this kind should have the following qualities. They should be strongly built, particularly as regards the stirrers so as to be used with thick mashes. They should thoroughly and uniformly stir and mix the mash and they should be capable of cooling the mash within an hour, and should be so constructed as to be easily cleaned. By using coils of pipe which may be inserted or withdrawn from the mash tub, and through which cold water is forced, the mash may be effectively cooled, but the best plan for quick cooling is to bring a comparatively thin layer of the mash in contact with the coils. This may be conveniently done by using a system of comparatively large water pipes enclosing small pipes for the passage of the mash. [Illustration: FIG. 4.--Mash Cooler, Water System.] This should be arranged in a stand like the coils of a radiator with an incline from the inlet end of the top pipe to the outlet end of the lowermost pipe. As stated, the small pipe carries the mash, the large pipe the water. Preferably the mash flows downward while the water is forced upward in a contrary direction by means of a pump or a high level reservoir. The cooled mash should flow into the fermenting tank at a temperature of about 68° F. There are many varieties of mash cooling apparatuses on the market of more or less complication suited to the needs of large and expensive plants. The form of cooler best to be used depends upon the circumstances of each case and whether thick or thin mashes are to be distilled. The cooler should, however, be capable of thorough cleansing so that no portion of one mashing be carried to another. =Fermentation= is an obscure and seemingly spontaneous change or decomposition which takes place in most vegetable and animal substances when exposed at ordinary temperatures to air and moisture. While fermentation broadly covers decay or putrifaction, yet it is limited in ordinary use to the process for producing alcoholic liquors from sacchariferous mashes. Fermentation is brought about by certain bodies called ferments--these are either organized, as vegetable ferments such as yeast, or unorganized as diastase--the enzyme of germinated malt. The last is used to convert starch into maltose, the first is used to convert maltose into fermentable sugar. The organized ferments are either to be found floating freely in the air under the name of wild yeast or are artificially produced. If a solution of pure sugar be allowed to stand so that it can be acted on by the organisms in the air, it will remain unaltered for a long time, but finally mold will appear upon it and it will become sour and dark-colored. If, however, a suitable ferment is added to it, such as yeast, it rapidly passes into a state of active fermentation by which the sugar is split up into alcohol and carbon dioxid, the process continuing from 48 hours to several weeks according to the temperature, the amount of sugar present, and the nature and quantity of the ferment. Fermentation cannot occur at a temperature much below 40° F., nor above 140° F. The limits of practical temperature, however, are 41° to 86° F. Brewer's yeast is chiefly employed in spirit manufacture. The most striking phenomena of fermentation are the turbidity of the liquid, the rising of gas bubbles to the surface, and the increase in temperature, the disappearance of the sugar, the appearance of alcohol and the clearing of the liquid. At the end a slight scum is formed on the top of the liquid and a light colored deposit at the bottom. This deposit consists of yeast which is capable of exciting the vinous fermentation in other solutions of sugar. The lower the temperature the slower the process, while at a temperature above 86° F. the vinous fermentation is liable to pass into other forms of fermentation to be hereafter considered. There are many theories of fermentation, of which the two most important are those of Pasteur and Buchner. The first teaches that fermentation is caused purely by the organic life of the yeast plant and is not a mere chemical action, whereas the second view most largely held to-day is that fermentation is a purely chemical change due to certain unorganized substances called "enzymes" present in the yeast. The theory need not detain us. It is sufficient that the yeast plant in some manner acts to decompose the saccharified mash into alcohol and carbonic acid gas. =Yeast= is a fungus, a mono-cellular organism, which under proper conditions propogates itself to an enormous extent. There are many races or varieties of yeast each having its peculiar method of growth. For our purposes we may divide the yeast races into two classes, wild yeast and cultivated yeast. Originally any of the yeast races were supposed to be good enough to effect fermentation but to-day every effort is made to procure and use only those races which have the greatest power to decompose sugar. It was for this reason that the old distiller kept portions of his yeast over from one fermentation to the next. This was yeast whose action they understood and whose abilities were proven. This yeast so kept was open, however, to the chance of contamination and yeast to-day is as carefully selected and bred as is a strain of horses, or dogs, or plants. After getting a portion of selected pure yeast for breeding purposes, it may be sowed, that is, propagated very carefully in a yeast mash, in sterilizing apparatus, where all chance of contamination by bacteria or wild yeast is avoided. From this bed of mother yeast, or start yeast, the yeast for the successive yeast mashes is taken. The preparation of the various varieties of yeast mashes is too lengthy to be set forth except in special treatises on the subject, but the ordinary method of yeasting is as follows, reference being made to Fig. 5, which shows the apparatus used in the yeasting and fermenting departments of a distillery, as installed by the Vulcan Copper Works, of Cincinnati. The yeast tubs are shown to the left of the illustration. They are each provided with cooling coils and stirrers. The yeast mash we will assume is composed of equal parts of barley malt and rye meal. Hot water at 166° F. is first put into the mash tub. The rake or stirrers are then rotated and the meal run in slowly. The stirring is continued for twenty minutes after the meal is all in, during which the mash has become saccharified. The mash is then allowed to stand for about twenty hours, and to grow sour by lactic fermentation. The lactic acid so produced protects the mother yeast from infection by suppressing wild yeast and bacteria. During this period great care is taken to prevent the temperature of the mash falling below 95° F. and consequent butyric and acetous fermentation following. After it has so stood the sour mash is cooled by circulating water in the coils and stirring until it is reduced to from 59° to 68° F. depending on whether the mash is thin or thick. Start yeast during the cooling of the mash when at above 86° F. is added and stirred in. For the next twelve hours the yeast ferments and when a temperature of 84° F. has been attained the mash is cooled to 65° F. at which temperature it is maintained until allowed to enter the fermenting tubs through the pipe leading thereto from the yeast tub. There are four principal kinds of fermentation: alcoholic, acetous, lactic and viscous. =Alcoholic Fermentation.= This may be briefly described as follows: The mash in the fermenting vat having been brought to the proper temperature, the ferment is thrown in, and the whole is well stirred together. This is known as pitching. [Illustration: FIG. 5.--Yeasting and Fermenting Apparatus. (_To face page 22_)] The proper pitching temperature varies with the method of fermentation adopted, the length of the fermenting period, the materials of the mash, its thickness or attenuation. It must always be remembered that there is a great increase in the temperature of the "beer" during fermentation and that the temperature at its highest should never under any circumstances, become greater than 86° F. and with thick mashes that even a less heat is desirable. Therefore the pitching temperature should be such that the inevitable rise due to fermentation shall not carry the temperature to or beyond the maximum point desired for the particular mash being treated. It is to accurately control the pitching temperature and the fermenting temperature that the fermenting tanks are provided with cooling appliances. In about three hours' time, the commencement of the fermentation is announced by small bubbles of gas which appear on the surface of the vat, and collect around the edges. As these increase in number, the whole contents are gradually thrown into a state of motion, resembling violent ebullition, by the tumultuous disengagement of carbonic anhydride. The liquor rises in temperature and becomes covered with froth. At this point, the vat must be covered tightly, the excess of gas finding an exit through holes in the lid; care must now be taken to prevent the temperature from rising too high, and also to prevent the action from becoming too energetic, thereby causing the contents of the vat to overflow. In about twenty-four hours the action begins to subside, and the temperature falls to that of the surrounding atmosphere. An hour or two later, the process is complete; the bubbles disappear, and the liquor, which now possesses the characteristic odor and taste of alcohol, settles out perfectly clear. The whole operation, as here described, usually occupies from forty-eight to seventy-two hours. The duration of the process is influenced, of course, by many circumstances, chiefly by bulk of the liquor, its richness in sugar, the quality of the ferment, and the temperature. =Acetous Fermentation.= This perplexing occurrence cannot be too carefully guarded against. It results when the fermenting liquor is exposed to the air. When this is the case, the liquor absorbs a portion of the oxygen, which unites with the alcohol, thus converting it into acetic acid as rapidly as it is formed. When acetous fermentation begins, the liquor becomes turbid, and a long, stringy substance appears, which after a time settles down to the bottom of the vat. It is then found that all the alcohol has been decomposed, and that an equivalent quantity of acetous acid remains instead. It has been discovered that the presence of a ferment and a temperature of 68° to 95° F. are indispensable to acetous fermentation, as well as contact with the atmosphere. Hence, in order to prevent its occurrence, it is necessary not only to exclude the air, but also to guard against too high a temperature and the use of too much ferment. The latter invariably tends to excite acetous fermentation. It should also be remarked that it is well to cleanse the vats and utensils carefully with lime water before using, in order to neutralize any acid which they may contain; for the least trace of acid in the vat has a tendency to accelerate the conversion of alcohol into vinegar. A variety of other circumstances are favorable to acetification, such as the use of a stagnant or impure water, and the foul odors which arise from the vats; stormy weather or thunder will also engender it. =Lactic Fermentation.= Under the influence of lactic fermentation, sugar and starch are converted into lactic acid. When it has once begun, it develops rapidly, and soon decomposes a large quantity of glucose; but as it can proceed only in a neutral liquor, the presence of the acid itself speedily checks its own formation. Then, however, another ferment is liable to act upon the lactic acid already formed, converting it into _butyric acid_, which is easily recognized by its odor of rank butter. Carbonic anhydride and hydrogen are evolved by this reaction. The latter gas acts powerfully upon glucose, converting it into a species of gum called _mannite_, so that lactic fermentation--in itself an intolerable nuisance--becomes the source of a new and equally objectionable waste of sugar. It can be avoided only by keeping the vats thoroughly clean; they should be washed with water acidulated with five per cent of sulphuric acid. An altered ferment, or the use of too small a quantity, will tend to bring it about. The best preventives are _thorough cleanliness_, and the use of good, fresh yeast in the correct proportion. =Viscous Fermentation.= This is usually the result of allowing the vats to stand too long before fermentation begins. It is characterized by the formation of viscous or mucilaginous matters, which render the liquor turbid, and by the evolution of carbonic anhydride and hydrogen gases the latter acting as in the case of lactic fermentation and converting the glucose into mannite. Viscous fermentation may generally be attributed to the too feeble action of the ferment. It occurs principally in the fermentation of white wines, beer, and beet-juice, or of other liquors containing much nitrogenous matter. It may be avoided by the same precautions as are indicated for the prevention of lactic fermentation. =Periods of Fermentation.= The operation of fermentation may be conveniently divided into three equal periods. The first or pre-fermentation period is that when the yeast mixed into the mash is growing; the temperature should then be kept at about 63 to 68° F. during which time the yeast is propagated. The growth of the yeast is manifested by the development of carbonic acid gas and by a slight motion of the mash. When alcohol is produced to an extent of say five per cent. the growth of the yeast stops. The second period of chief fermentation then begins. Carbonic acid is freely developed and the sugar is converted into alcohol. The temperature at this time should not exceed 81.5° F. The second period of fermentation continues about 12 hours, when the last period commences. During the third period or after fermentation there is a lessening of the formation of carbonic acid and a lowering of the temperature. In this stage the mash is kept at a temperature of 77° to 81° F. In order to conveniently regulate the temperature of the mash the vat may be provided with a copper worm at the bottom thereof, through which cold water is forced. This, however, need only be used for thick mashes. There are also various kinds of movable coolers used for this purpose. There are a number of different forms which fermentation may take. The insoluble constituents of the mash in the process of fermentation are forced to the surface, and form what may be termed a cover. If the carbonic acid gas bubbles seldom break this cover it indicates that the conversion of the sugar into alcohol and carbonic acid is proceeding very slowly and imperfectly. If, however, the cover is swirling and seething, and particularly if the cover is rising and falling with every now and then a discharge of gas, it is an indication that the conversion is properly proceeding. Foaming of the mash is to be prevented, as the froth or foam flows over the mash tank and considerable loss is sustained. It may be prevented by pouring a little hot lard into the vat, or petroleum, provided its odor will not interfere with the use of the alcohol when distilled. Water is added in small quantities near the termination of the second period of fermentation. This dilutes the alcohol, in the mash and lessens its percentage, and thus the further growth of the yeast is permitted. After fermentation the mash takes either the form of a thick diluted pulp or of a thin liquor. Again the reader is reminded that the mash after fermentation contains alcohol mixed with water--and that the next step in the process--distillation is necessary merely to separate the alcohol from the water. There is always some loss in the process of fermentation; in other words, the actual production is below the theoretical amount due. Theoretically one pound of starch should yield 11.45 fluid ounces of alcohol. With a good result 88.3 per cent. of this theoretical yield is obtained; with an average result of 80.2 per cent. and with a bad result only about 72.6 per cent. or less. =Fermenting Apparatus.= It remains now to describe briefly the vessels or vats employed in the processes of fermentation. They are made of oak or cypress, firmly bound together with iron bands, and they should be somewhat deeper than wide, and slightly conical, so as to present as small a surface as possible to the action of the air. Their dimensions vary, of course, with the nature and quantity of the liquor to be fermented. Circular vats are preferable to square ones, as being better adapted to retain the heat of their contents. The lid should close securely, and a portion of it should be made to open without uncovering the whole. For the purpose of heating or cooling the contents when necessary, it is of great advantage to have a copper coil at the bottom of the vat, connected with two pipes, one supplying steam and the other cold water. =Iron vats= have also been used, having a jacketed space around them, into which hot or cold water may be introduced. As wooden vats are porous and hence uncleanly they have to be constantly scrubbed and disinfected. It is advisable to cover the interior with linseed oil, varnish or with a shellac varnish. The diameter of the coil varies according to the size of the vat. =The room= in which the vats are placed should be made as free from draughts as possible by dispensing with superfluous doors and windows; it should not be too high and should be enclosed by thick walls in order to keep in the heat. As uniformity of temperature is highly desirable, a thermometer should be kept in the room, and there should be stoves for supplying heat in case it be required. The temperature should be kept between 64° F. and 68° F. Every precaution must be taken to ensure the most absolute cleanliness; the floors should be swept or washed with water daily, and the vats, as pointed out above, must be cleaned out as soon as the contents are removed. For washing the vats, lime-water should be used when the fermentation has been too energetic or has shown a tendency to become acid; water acidulated with sulphuric acid is used when the action has been feeble and the fermented liquor contains a small quantity of undecomposed sugar. Care must be taken to get rid of carbonic anhydride formed during the operation. Buckets of lime-water are sometimes placed about the room for the purpose of absorbing this gas; but the best way of getting rid of it is to have a number of holes, three or four inches square, in the floor, through which the gas escapes by reason of its weight. The dangerous action of this gas and its effects upon animal life when unmixed with air are too well know to necessitate any further enforcement of these precautions. =The beer= obtained by mashing and fermenting consist essentially of volatile substances, such as water, alcohol, essential oils and a little acetic acid, and of non-volatile substances, such as cellulose, dextrine, unaltered sugar and starch, mineral matters, lactic acid, etc. =The volatile constituents= of the liquor possess widely different degrees of volatility; the alcohol has the lowest boiling point, water the next, then acetic acid, and last the essential oils. It will thus be seen that the separation of the volatile and non-volatile constituents by evaporation and condensation of the vapors given off is very easily effected, and that also by the same process, which is termed _distillation_, the volatile substances may be separated from one another. As the acetic acid and essential oils are present only in very small quantities, they will not require much consideration. The aim of distillation is to separate as completely as possible the alcohol from the water which dilutes it. Table I shows the amount of alcohol contained in the vapors given off from alcoholic liquids of different strength, and also their boiling points. A glance at this table shows to what an extent an alcoholic liquor may be strengthened by distillation, and how the quantity of spirit in the distillate increases in proportion as that contained in the original liquor diminishes. It will also be seen that successive distillations of spirituous liquors will ultimately yield a spirit of very high strength. As an example, suppose that a liquid containing five per cent, of alcohol is to be distilled. Its vapor condensed gives a distillate containing 42 per cent. of alcohol which, if re-distilled, affords another containing 82 per cent. This, subjected again to distillation, yields alcohol of over 90 per cent. in strength. Thus three successive distillations have strengthened the liquor from five per cent. to 90 per cent. It will thus be clear that the richness in alcohol of the vapors given off from boiling alcoholic liquids is not a constant quantity, but that it necessarily diminishes as the ebullition is continued. For example a liquor containing seven per cent. of alcohol yields, on boiling a vapor containing 50 per cent. The first portion of the distillate will, therefore, be of this strength. But as the vapor is proportionally richer in alcohol, the boiling liquor must become gradually weaker, and, in consequence, must yield weaker vapors. Thus, when the proportion of alcohol in the boiling liquid has sunk to five per cent., the vapors condensed at that time will contain only 40 per cent.; at two per cent. of alcohol in the liquor, the vapors yield only 28 per cent., and at one per cent., they will be found when condensed to contain only 13 per cent. From this it will be understood that if the distillation be stopped at any given point before the complete volatilization of all the alcohol the distillate obtained will be considerably stronger than if the process had been carried on to the end. Moreover, another advantage derived from checking the process before the end, and keeping the last portions of the distillate separate from the rest, besides that of obtaining a stronger spirit, is that a much purer one is obtained also. The volatile, essential oils, mentioned above, are soluble only in strong alcohol, and insoluble in its aqueous solutions. They distill also at a much higher temperature than alcohol, and so are found only among the last products of the distillation, which results from raising the temperature of the boiling liquid. This system of checking the distillation and removing the products at different points is frequently employed in the practice of rectification. CHAPTER III. DISTILLING APPARATUS. =The Apparatus= employed in the process of distillation is called a _still_, and is of almost infinite variety. A still may be any vessel which will hold and permit fermentated "wash" or "beer" to be boiled therein, and which will collect the vapors arising from the surface of the boiling liquid and transmit them to a condenser. The still may be either heated by the direct application of fire, or the liquid in the still raised to the boiling point by the injection of steam. The steam or vapor rising from the boiling liquid must be cooled and condensed. This is done by leading it into tubes surrounded by cold water or the "cold mash." The very simplest form of still is shown in Fig. 6, and consists of two essential parts, the still, or boiler _A_, made of tinned copper, the condenser _C_ which may be made of metal or wood and the worm _B_ made of a coil of tinned copper pipe. The liquor is boiled in _A_ and the vapors pass off into the worm _B_, which is surrounded by the cold water of the condenser, the distillate being drawn off at _f_. The heated vapors passing through the worm _B_ will soon heat up the water in _C_ thereby retarding perfect condensation. To prevent this, a cold water supply pipe may be connected to the bottom of _C_ making a connection at the top of _C_ for an over flow of the warmed up water. By this means the lowest part of the worm will be kept sufficiently cool to make a rapid condensation of the vapors. [Illustration: FIG. 6.--A Simple Still.] The boiler _A_ can be made in two parts; the upper part fitting into the lower part snugly at _d_. The pipe from the upper part fitting the worm snugly at _e_. This will enable the operator to thoroughly cleanse the boiler before putting in a new lot of liquor. The joints at _e_ and _d_ should be luted with dough formed by mixing the flour with a small portion of salt and moistening with water. This is thoroughly packed at the junctions of the parts to prevent the escape of steam or vapor. Fig. 7 shows such a Still as manufactured by the Geo. L. Squier Mfg. Co., Buffalo, N. Y. [Illustration: FIG. 7.--Simple Direct-Heated Still.] In an apparatus of this kind, the vapors of alcohol and water are condensed together. But if instead of filling the condenser _C_ with cold water, it is kept at a temperature of 176° F. the greater part of the water-vapor will be condensed while the alcohol, which boils at 172.4° F. passes through the coil uncondensed. If therefore the water be condensed and collected separately in this manner, and the alcoholic vapors be conducted into another cooler kept at temperature below 172.4° F., the alcohol will be obtained in a much higher state of concentration than it would be by a process of simple distillation. Supposing, again, that vapors containing but a small quantity of alcohol are brought into contact with an alcoholic liquid of lower temperature than the vapors themselves, and in very small quantity, the vapor of water will be partly condensed, so that the remainder will be richer in alcohol than it was previously. But the water, in condensing, converts into vapor a portion of the spirit contained in the liquid interposed, so that the uncondensed vapors passing away are still further enriched by this means. Here, then, are the results obtained; the alcoholic vapors are strengthened, firstly, by the removal of a portion of the water wherewith they were mixed; and then by the admixture with them of the vaporized spirit placed in the condenser. By the employment of some such method as this, a very satisfactory yield of spirit may be obtained, both with regard to quality, as it is extremely concentrated, and to the cost of production, since the simple condensation of the water is made use of to convert the spirit into vapor without the necessity of having recourse to fuel. The construction of every variety of distilling apparatus now in use is based upon the above principles. A sectional view of another simple form of still is shown in Fig. 8; _V_ is a wooden vat having a tight fitting cover _a_, through the center of which a hole has been cut. The wide end of a goose neck of copper pipe _g_ is securely fitted over this aperture, the smaller end of this pipe passes through the cover of the retort _R_ extending nearly to the bottom; _f_ is the steam supply pipe from boiler; _M_ the rectifier consisting of a cylindrical copper vessel containing a number of small vertical pipes surrounded by a cold water jacket; _o_ the inlet for the cold water which circulates around these small pipes, discharging at _n_; the pipes in _M_ have a common connection to a pipe _p_, which connects the rectifier with coil in cooler _C_; _s_ is a pipe to the receptacle for receiving the distillate; _u_ cold water supply pipe to cooler, and _W_ discharge for warmed-up water, _k_ discharge for refuse wash in vat _V_. [Illustration: FIG. 8.--Simple Still, with Rectifier.] The operation is as follows: The vat _V_ is nearly filled with fermented mash and retort _R_ with weak distillate from a previous operation. Steam is then turned into the pipe _f_ discharging near the bottom of the vat _V_ and working up through the mash. This heats up the mash and the vapors escape up _g_ over into _R_ where they warm up the weak distillate. The vapors thus enriched rise into _M_, where a good percentage of the water vapor is distilled, that is, condensed by the cold water surrounding the small pipes. The vapor then passes over through _p_ into the coil, where it is liquified and from whence it passes by pipe _s_ into the receiver. The cold water for cooling both _M_ and _C_ can be turned on as soon as the apparatus has become thoroughly heated up. The stills in use to-day in many parts of the South for the production of whiskey are quite as simple as those above described, and some for the making of "moonshine" liquor are more so. The first distilling apparatus for the production of strong alcohol on an industrial scale was invented by Edward Adam, in the year 1801. The arrangement is shown in Fig. 9, in which _A_ is a still to contain the liquor placed over a suitable heater. The vapors were conducted by a tube into the egg-shaped vessel _B_, the tube reaching nearly to the bottom; they then passed out by another tube into a second egg _C_; then, in some cases, into a third, not shown in the figure, and finally into the worm _D_, and through a cock at _G_ into the receiver. The liquor condensed in the first egg is stronger than that in the still, while that found in the second and third is stronger than either. The spirit which is condensed at the bottom of the worm is of a very high degree of strength. At the bottom of each of the eggs, there is a tube connected with the still, by which the concentrated liquors may be run back into _A_ for redistillation after the refuse liquor from the first distill has been run off. [Illustration: FIG. 9.--Adam's Still.] In the tube is a stop-cock _a_, by regulating which, enough liquor could be kept in the eggs to cover the lower ends of the entrance pipes, so that the alcoholic vapors were not only deprived of water by the cooling which they underwent in passing through the eggs, but were also mixed with fresh spirit obtained from the vaporization of the liquid remaining in the bottom of the eggs, in the manner already described. Adam's arrangement fulfilled, therefore, the two conditions necessary for the production of strong spirit inexpensively; but unfortunately it had also serious defects. The temperature of the egg could not be maintained at a constant standard, and the bubbling of the vapors through the liquor inside created too high a pressure. It was, however, a source of great profit to its inventor for a long period, although it gave rise to many imitations and improvements. The operation of distilling is often carried on in the apparatus represented in Fig. 22. It is termed the Patent Simplified Distilling Apparatus; it was originally invented by Corty, but it has since undergone much improvement. _A_ is the body of the still, into which the wash is put; _B_ the head of the still; _c c c_ three copper plates fitted in the upper part of the three boxes; these are kept cool by a supply of water from the pipe _E_, which is distributed on the top of the boxes by means of the pipes _G G G_. The least pure portion of the ascending vapors is condensed as it reaches the lowest plate, and falls back, and the next portion as it reaches the second plate, while the purest and lightest vapors pass over the goose-neck, and are condensed in the worm. The temperature of the plates is regulated by altering the flow of water by means of the cock _F_. For the purpose of cleaning the apparatus, a jet of steam or water may be introduced at _a_. A regulator is affixed at the screw-joint _H_, at the lower end of the worm, which addition is considered an important part of the improvement. The part of the apparatus marked _I_ becomes filled soon after the operation has commenced; the end of the other pipe _K_ is immersed in water in the vessel _L_. The advantage claimed for this apparatus is that the condensation proceeds in a partial vacuum, and that there is therefore a great saving in fuel. One of these stills, having a capacity of 400 gallons, is said to work off four or five charges during a day of 12 hours, furnishing a spirit 35 per cent. over-proof. [Illustration: FIG. 10.--Corty's Simplified Distilling Apparatus.] Fig. 11 represents a double still which was at one time largely employed in the colonies. It is simply an addition of the common still _A_ to the patent still _B_. From time to time the contents of _B_ are run off into _A_, those of _A_ being drawn off as dunder, the spirit from _A_ passing over into _B_. Both stills are heated by the same fire; and it is said that much fine spirit can be obtained by their use at the expense of a very inconsiderable amount of fuel. [Illustration: FIG. 11.--Double Still.] =Compound Distillation.= Where stills of the form shown in Figs. 6 and 8 are used the alcohol obtained is weak. Hence it is necessary that the distillate be again itself distilled, the operation being repeated a number of times. In the better class of still, however, compound distillation is performed the mash is heated by the hot vapors rising from the still and the vapors are condensed and run back into the still greatly enriched. [Illustration: FIG. 12.--Dorn's Compound Still.] The principle of compound distillation is well shown in Dorn's apparatus, Fig. 12. This consists of a still or boiler _A_ having a large dome-shaped head, on the interior faces of which the alcoholic vapors will condense. Thus only enriched vapors will pass up through goose-neck _B_ to the mash heater _D_. _C_ is a worm the end of which passes out to a compartment _E_ through an inclined partition _F_. From the compartment _E_ a pipe _e_ leads into the still _A_. An agitator _H_ is used for stirring the mash, so that it may be uniformly heated. A pipe _d_ provided with a cock allows the mash to be drawn off into the still _A_. From the highest point of the compartment _E_ a pipe _M_ leads to condensing coil _K_ in a tub _J_ of cold water, having a draw-off cock _I_. At the exit end of the condensing worm _K_ the tube is bent in a U form as at _L_, one arm of which has a curved open-ended continuation _n_, through which the air in the worm is expelled. The other arm opens into an inverted jar _l_ containing a hydrometer, for indicating the strength of the spirit. The spirits pass off through _m_ into a receiver. In operation the mash is admitted into the heater _D_ through _G_ until the heating tank is nearly filled. A certain amount of mash is then allowed to run into the still _A_ through the pipe _d_. The cock in _d_ is closed and the fire lighted. The vapors from the still are condensed in worm _C_ and the condensed liquid drops down into compartment _E_. Any vapor passing through _B_ and _C_ so highly heated as to be uncondensed in coils _C_ passes through the layer of liquid in compartment _E_, collects in the highest portion of the compartment and passes through pipe _M_ to coil _K_ where it is entirely liquefied. If the liquid in _E_ rises beyond a certain level it passes through pipe _e_ back to the still. Any vapors which may collect in the upper part of _D_ pass into the small bent pipe opening into the first coil of worm _C_. Water for rinsing the heater _D_ may be drawn through cock _s_ from the tub _J_ and warm water for rinsing the still, through pipe _d_ from the heater. Another form of compound still is shown in Fig. 13. In this the still _S_ is divided into an upper and lower compartment by a concavo-convex partition _d_, having at its crown an upwardly extending tube _t_ from which projects side tubes _p_. A pipe _P_ opens above and extends from tube _t_. _C_ is the mash heater and condenser. Connected to the head of the still is a pipe _T_ through which the vapors pass to a condensing coil _f_ formed on the wall of the heater _C_. At its bottom the coil _f_ extends out of the heater, through the water tub _W_ and out to receiver as at _F_. In the heat of this heater is a valve _V_ whereby any vapors which may arise from the heated mash are conducted by pipe _U_ to _T_. The heater _C_ is filled through funnel _Y_ and the mash is admitted to the still through pipe _b_ having cock _a_. The pipe _P_ extends to the upper part of the water tub _W_ and then downward to the bottom, where it again enters the still. An opening in the partition _d_ is controlled by a valve _G_ which allows liquid in the upper compartment of the still to flow into the lower. Spent mash may be drawn off through _c_ and the height of the water in tub _W_ be regulated by pipe _Z_. [Illustration: FIG. 13.--Compound Still.] The operation of this still is similar to Dorn's still. Mash is put into _C_ and a quantity of it is let into the upper compartment of the still and into the lower compartment by valve _G_. This valve is closed and the fire started. The vapors pass upward through _t_. If they are quite highly vaporized they pass onward up _P_, are condensed in their passage through the cool water tub and return as liquid to the upper compartment where they are further heated. The liquid in the upper compartment is thus constantly enriched and the vapor therefrom passes out through pipe _T_ into condensing coils _f_ where it is condensed into spirit and passes off by _F_. The funnel tube _Y_ acts also as a means of warning the attendant as to the condition of the mash. If it is too high in level and the pressure of vapor in the heater _C_ too great, liquid will be forced out of _Y_; if on the contrary, the mash sinks below the level of the pipe then vapor will escape and the heater needs refilling. [Illustration: FIG. 14.--Compound Direct Fire Still.] Fig. 14 shows a simple form of compound direct fire still as manufactured by the Geo. L. Squier Mfg. Co., of Buffalo, N. Y. Cellier-Blumenthal carrying this principle further devised an apparatus which has become the basis of all subsequent improvements; indeed, every successive invention has differed from this arrangement merely in detail, the general principles being in every case the same. The chief defect in the simple stills was that they were intermittent that is required the operations to be suspended when they were recharged, while that of Cellier-Blumenthal is continuous; that is to say, the liquid for distillation is introduced at one end of the arrangement, and the alcoholic products are received continuously, and of a constant degree of concentration, at the other. The saving of time and fuel resulting from the use of his still is enormous. In the case of the simple stills, the fuel consumed amounted to a weight nearly three times that of the spirit yielded by it; whereas, the Cellier-Blumenthal apparatus reduces the amount to one-quarter of the weight of alcohol produced. Fig. 15 shows the whole arrangement, and Figs. 16 to 17 represent different parts of it in detail. [Illustration: FIG. 15.--Cellier-Blumenthal Still.] In Fig. 15 _A_ is a boiler, placed over a brick furnace; _B_ is the still, placed beside it, on a slightly higher level and heated by the furnace flue which passes underneath it. A pipe _e_ conducts the steam from the boiler to the bottom of the still. By another pipe _d_, which is furnished with a stop cock and which reaches to the bottom of the still _A_, the alcoholic liquors in the still may be run from it into the boiler; by turning the valve the spent liquor may be run out at _a_. The glass tubes _b_ and _f_ show the height of liquid in the two vessels. _K_ is the valve for filling the boiler and _c_ the safety valve. [Illustration: FIG. 16.--Details of Rectifier Column.] The still is surmounted by a column _C_, shown in section in Fig. 16. This column contains an enriching arrangement whereby the liquid flowing down into the still _B_ is brought into intimate contact with the steam rising from the still. The liquid meets with obstacles in falling and falls downward in a shower, which thus presents multiplied obstacles to the ascent of the vapor. The liquid is thus heated almost to the boiling point before it falls into the still _B_. The construction for effecting this is shown at _C_, Fig. 16 and consists of an enclosed series of nine sets of circular copper saucer-shaped capsules, placed one above the other, and secured to three metallic rods passing through the series so that they can be all removed as one piece. These capsules are of different diameters, the larger ones which are, nearly the diameter of the column, are placed with the rounded side downwards, and are pierced with small holes; the smaller ones are turned bottom upwards, a stream of the liquid to be distilled flows down the pipe _h_ from _E_, into the top capsule of _C_ and then percolating through the small holes, falls into the smaller capsule beneath, and from the rim of this upon the one next below, and so throughout the whole of the series until it reaches the bottom and falls into the still _B_. The vapors rise up into the column from the still and meeting the stream of liquid convert it partially into vapor which passes out at the top of _C_ considerably enriched, into the column _D_. Fig. 16 shows a sectional view of the column _D_, the "rectifying column" as it is called. It contains six vessels, placed one above the other, in an inverted position, so as to form seals. These are so disposed that the vapors must pass through a thin layer of liquor in each vessel. Some of the vapor is thus condensed and the condensed liquid flows back into column _C_, the uncondensed vapor considerably enriched passing up the pipe _J_, into the coil _S_ in the condenser _E_, Fig. 17, which is filled with the "wash" to be distilled. [Illustration: FIG. 17.--Details of Condenser and Mash Heater.] Entering by the pipe _t_, Fig. 15, the undistilled liquid or "wash" is distributed over a perforated plate _y y_, and falls in drops into the condenser _E_, where it is heated by contact with the coil _S_ containing the heated vapors. The condenser is divided into two compartments by a diaphragm _X_ which is pierced with holes at its lower extremity; through these holes the wash flows into the second compartment, and passes out at the top, where it runs through the pipe _h_, into the top of the column _C_. The vapors are made to traverse the coil _S_, which is kept at an average temperature of 122° F., in the right hand compartment, and somewhat higher in the other. They pass first through _J_ into the hottest part of the coil, and there give up much of the water with which they are mixed, and the process of concentration continues as they pass through the coil. Each spiral is connected at the bottom with a vertical pipe by which the condensed liquors are run off; these are conducted into the retrograding pipe _p p_. Those which are condensed in the hottest part of the coil, and are consequently the weakest, are led by the pipe _L_ into the third vessel in the column _D_, Fig. 16, while the stronger or more vaporized portions pass through _L´_ into the fifth vessel. Stop-cocks at _m_, _n_, _o_ regulate the flow of the liquid into these vessels, and consequently also the strength of the spirit obtained. Lastly, as the highly concentrated vapors leave the coil _S_ at _R_, they are condensed in the vessel _F_, which contains another coil. This is kept cool by a stream of liquid flowing from the reservoir _H_ into the smaller cistern _G_ from which a continuous and regular flow is kept up through the tap _v_ into a funnel _N_ and thence into condenser _F_. It ultimately flows into condenser _E_ through pipe _t_, there being no other outlet. The finished products run out by pipe _x_ into suitable receivers. It will be seen that the condenser _E_ has two functions. First it condenses the alcoholic vapors before transmitting them to the final condenser _F_, rejecting and sending back those vapors which are not highly enough vaporized. Second it heats the wash intended for distilling by appropriating the heat of the vapors to be condensed. Thus two birds are killed with one stone. It will be noticed that the same result is accomplished in the columns _C_ and _D_. This is the principle of all modern stills. Another form of still which is very analogous to that last described is Coffey's apparatus, shown in Fig. 18, and is the immediate prototype of the stills used to-day in all but the simplest plants. [Illustration: FIG. 18.--Coffey's Rectifying Still.] It consists of two columns, _C_ the analyser, and _H_ the rectifier, placed side by side and above a chamber containing a steam pipe _b_ from a boiler _A_. This chamber is divided into two compartments by a horizontal partition _a_ pierced with small holes and furnished with four safety valves _e e e e_. The column _C_ is divided into twelve small compartments, by means of horizontal partitions of copper, also pierced with holes and each provided with two little valves _f_. The spirituous vapors passing up this column are led by a pipe _i_ to the bottom of the second column or _rectifier_. This column is also divided into compartments in precisely the same way, except that there are fifteen of them, the ten lowest being separated by the partitions, which are pierced with holes. The remaining five partitions are not perforated, but have a wide opening as at _w_, for the passage of the vapors, and form a condenser for the finished spirit. Between each of these partitions passes one bend of a long zig-zag pipe _m_, beginning at the top of the column, winding downwards to the bottom, and finally passing upwards again to the top of the other column, so as to discharge its contents into the highest compartment. The apparatus works in the following way: The pump _Q_ is set in motion, and the zig-zag pipe _m_ then fills with the wash or fermented liquor until it runs over at _n_ into the highest compartment of column _C_. The pump is then stopped, and steam is introduced through _b_, passing up through the two bottom chambers and the short pipe _F_ into the analyzing column, finally reaching the bottom of the other column by means of the pipe _i_. Here it surrounds the coil pipe _m_ containing the wash, so that the latter becomes rapidly heated. When several bends of the pipe have become heated, the pump is again set to work, and the hot wash is driven rapidly through the coil and into the analyzer at _n_. Here it takes the course indicated by the arrows, running down from chamber to chamber through the tubes _h_ until it reaches the bottom; none of the liquor finds its way through the perforations in the various partitions, owing to the pressure of the ascending steam. As the liquid cannot pass through the holes in the partitions it can only pass downward through the drop-pipe tubes _h_. By this means the mash is spread in a thin stratum over each partition to the depth of the seal _g_ and is fully exposed to the steam forcing its way up through the holes, the alcohol it contains being thus volatilized at every step. In its course downwards the wash is met by the steam passing up through the perforations, and the whole of the spirit which it contains is thus converted into vapor. As soon as the chamber _B_ is nearly full of the spent wash, its contents are run off into the lower compartment by opening a valve in the pipe _V_. By means of the cock _E_, they are finally discharged from the apparatus. This process is continued until all the wash has been pumped through. The course taken by the steam will be readily understood by a glance at the figure. When it has passed through each of the chambers of the analyzer, the mixed vapors of water and spirit pass through the pipe _i_ into the rectifying column. Ascending again, they heat the coiled pipe _m_, and are partially deprived of aqueous vapors by condensation. Being thus gradually concentrated, by the time they reach the opening at _w_ they consist of nearly pure spirit, and are then condensed by the cool liquid in the pipe, fall upon the partition and are carried away by the pipe _y_ to a refrigerator _W_. Any uncondensed gases pass out by the pipe _R_ to the same refrigerator, where they are deprived of any alcohol they may contain. The weak liquor condensed in the different compartments of the rectifier descends in the same manner as the wash descends in the other column; as it always contains a little spirit, it is conveyed by means of the pipe _S_ to the vessel _L_ in order to be pumped once more through the apparatus. =The condensed spirit= gathered over the plates _v_ passes out through the pipe _y_ to the condensing worm _T_. If any vapors escape the condensing plates they pass into _R_ and are condensed in the worm _T_ also. From worm _T_ the spirit flows into a suitable receiver _Z_. Before the process of distillation commences, it is usual, especially when the common Scotch stills are employed, to add about one lb. of soap to the contents of the still for every 100 gallons of wash. This is done in order to prevent the liquid from boiling over, which object is effected in the following way: The fermented wash always contains small quantities of acetic acid; this acts upon the soap, liberating an oily compound which floats upon the surface. The bubbles of gas as they rise from the body of the liquid are broken by this layer of oil, and hence the violence of the ebullition is considerably checked. Butter is sometimes employed for the same purpose. Figs. 19 and 20 show a diagrammatic section and a plan of a still used for thick mashes which are liable to burn. This comprises a circular chamber _B_ supported over suitable heating means, having on its bottom a series of concentric partitions _b_ which divide the bottom of the chamber into shallow channels for the mash. Running diametrically through the chamber is a partition. [Illustration: FIG. 19.--Rotary Current Still.] The mash passes from a tank as _A_ by a passage _a_ to an opening on one side of the central portion and into the outside channel _b_. The current of liquid passes along the outer channel until it is deflected by the central partition into the next interior channel _b_ and so on until it arrives at the center when it passes through the central partition into the other half of the chamber. Here it passes around back and forth and gradually outward to the outermost channel from which it passes off through an adjustable gate in outlet _c_. By adjusting this gate, and a gate or cock in inlet passage _a_, the passage and consequent depth of the liquid in the channels may be regulated. The vapor rising from the mash is carried over to a condenser through pipe _D_. In order to keep the mash from burning a chain _g_ is rotarily reciprocated along the channels by means of the bar _G_, the gear _E_ and the crank shaft _e_. Various modifications of this construction have been devised. The advantage of the still lies in submitting the mash in a thin current to the action of the heat, and the consequent rapid vaporization. [Illustration: FIG. 20.--Rotary Current Still.] Every distillation consists of two operations: The conversion of liquid into vapor, and the reconversion of the vapor into liquid. Hence perfect equilibrium should be established between the vaporizing heat and the condensing cold. The quantity of vapor must not be greater or less than can be condensed. If fire is too violent the vapors will pass out of the worm uncondensed. If the fire is too low the pressure of the vapor is not great enough to prevent the entrance of air, which obstructs distillation. As a means of indicating the proper regulation of the fire, the simple little device shown in Fig. 21 may be used. This consists of a tube of copper or glass having a ball _B_ eight inches in diameter. The upper end _E_ of the tube is attached to the condensing worm. The lower end of the tube is bent in U-shape; the length of the two bends from _b_ to outlet is four feet. The ball has a capacity slightly greater than the two legs of the bend. [Illustration: FIG. 21.--Indicator for Regulating the Distilling Fire.] Normally the liquid in the two legs will stand at a level. If, however, the fire is too brisk the vapor will enter the tube and drive out the liquor at _d_, and thus the level in the leg _C_ will be less than in the leg _D_. If, however, the fire is low, the pressure of vapor in the worm will decrease and the pressure of the outside air will force down the liquid in leg _D_ and up leg _C_ into the ball. A more perfected device but operating on the same principle is shown in Fig. 26. It is obviously impossible to present in the small compass of this book a description of all the varieties of stills used, but these which have been described illustrate the principles on which all stills are constructed and were chosen for their simplicity of construction and clearness of their operation. The principle of their operation is exactly the same as the more modern forms now to be described. CHAPTER IV. MODERN DISTILLING APPARATUS. In the previous chapter we have given a description of small, simple stills, such as were used until late years, and which are yet used in many localities where distilling is carried on on a small scale. We will now describe the principle features of more complicated and elaborate apparatus. All modern distilling apparatus for the production of a high grade of alcohol is based upon the principle set forth in the description of the Coffey still; that is, upon using a distilling column and a concentrating column, wherein the "wash" or mash fermented as described, passes over a series of plates or other obstructions in contact with an ascending column of heated vapor. This heated vapor extracts the alcohol from the wash, or from the low wines of the concentrator, and is continually strengthened during its journey until it passes off to a condenser as a vapor very rich in alcohol. The converse of this is true with the wash, which in its downward course is gradually deprived of its alcohol until it finally passes off at the bottom of the column. [Illustration: FIG. 22.--Diagramatic View of Column Still and Accessory Apparatus. (_To face page 64_)] Fig. 22 is illustrative of the general form and arrangement of such a column and its adjuncts; the details, however, will vary with each make of still. In this the "column" consists of a casing really continuous but divided into two portions--the distilling portion _A_ and the rectifying portion _B_. The operation is alike, however, in principle in both portions. [Illustration: Cross-Section of Fig. 23.] [Illustration: FIG. 23.--Distilling Plate.] The wash by means of a suitable pump is forced into an overhead tank or concentrator _G_ where it is warmed by the hot vapors as will be later described. It passes around the interior of the concentrator in a coil _c_ and then passes off by a pipe _a_ to the uppermost plate of the distilling portion _A_ of the column. The plates, as before explained on page 55, are each formed with a dropping tube _O_ (see Fig. 23), which extends above the plate to an extent slightly less than the desired thickness of the layer of liquid on each plate, and with perforations each having an upwardly projecting rim, and each covered with a cap _A_. This rim and cap form a trap. The ascending vapors pass up through the perforations, down between the rim and the edge of the cap and thus out through the layer of wash contained on the cap. The wash remains constantly level with the top of the tube _O_, the excess running off through the tube _O_ to the compartment or plate beneath. To return to Fig. 22, the wash by the pipe _a_ enters the distilling portion of the column at the uppermost plate thereof and, as described above, drops down from plate to plate. A steam pipe _S_ enters the bottom compartment of the distilling portion of the column and the steam as it rises through the little traps, bubbles out through the layer of wash and in each compartment enriches itself with alcohol. Thus the rising column of vapor is constantly becoming richer and the downward current of wash constantly weaker until at last it passes away as spent wash at the very bottom of the column by the pipe _D_. The hot vapors, as before described, pass upward and enter the rectifying portion of the column _B_. This consists of a series of compartments having perforated bottoms and dropping tubes. The vapor passes upward through these perforations of the plates,--the condensed portion of it dropping back again on to the lower plates or on to the distilling plates to be again vaporized and concentrated and the more highly vaporized portion passing out at the top of the column through the pipe _E_ to the concentrator _G_. The concentrator consists of a tank containing water within which is supported a vessel _F_ having double walls. The interior of this vessel is likewise filled with water. Between the double walls and surrounding the coiled pipe _c_ passes the vapors from pipe _E_. At the bottom of the vessel _F_ is a compartment _f_ connected by a pipe _F´_ with the upper compartment of the rectifying column. The less highly heated vapors will be condensed by the passage through the double walls of the vessel and the condensation will collect in the compartment _f_, and from there pass off by pipe _F´_ back to the rectifying column, to be again vaporized and strengthened by the descent from plate to plate of _B_. The rich and highly vaporized vapors which have passed the test of this preliminary concentration, pass out of the compartment _f_ by a pipe _M_. Here again the water surrounding the pipe tends to condense all but the most highly charged vapor and send it back to compartment _f_ but the vapor which succeeds in passing over through pipe _G_ is carried downward to a condenser _H_ where it is finally condensed and drawn off as at _g_. It is necessary that the rate of mash feed be regulated so that neither too much mash shall be pumped into the mash heater _G_, or too little, and the pipe leading from the pump to the heater is therefore provided with a tap and an indicating dial. In these modern stills the following are particularly important points to be especially brought to the consideration of the distiller. It cannot be too strongly impressed that effectiveness of the distilling column depends on the plates dividing it,--that is, upon the horizontality of the plates and the form of the traps or perforations. If the plates are not horizontal the wash is not maintained at a uniform level across the entire extent of the plate and hence some of the ascending vapor will pass out without contacting with the wash through uncovered traps, while others of the traps will be so deeply submerged in wash that the vapor cannot bubble through. Again the caps should be so made as to divide the vapor into fine streams and bring it into contact with each part of the wash. Plates simply perforated and uncapped give excellent results for they molecularize the vapor ascending through the liquid contained on the plates, but they require a constant pressure of vapor, and any variations of pressure tends to discharge them. In addition these perforations gradually enlarge by the action of acids in the wash or clog up, and the apparatus soon works badly. Good forms of capped traps are those shown in Figs. 24, 25 devised by Barbet. These are provided with an interior upwardly projecting rim. Extending over the rim and down around it is a copper cap having its margin slitted. The wash carried on the plate circulates about the caps and the alcoholic vapors bubble out through the slits and up through the wash, the vapor thus being finely divided and coming into intimate contact with each portion of the wash and thus more thoroughly depriving it of its alcohol. [Illustration: FIG. 24.--Barbet Trap.] [Illustration: FIG. 25.--Barbet Trap.] Besides this there is another advantage resident in these caps, namely, that distillation may be stopped for several hours and then re-started without trouble for the reason that the wash has been retained on the plates, whereas were the plates simply perforated the wash would ooze through and the plates have to be recharged. This form of plate may be easily repaired and does not necessitate the removal or replacement of the plate itself. The caps alone need be removed. For thick washes, which tends to obstruct the slits of the cap, Barbet has devised the cap shown at the right in Fig. 25. This cap extends down to the plate itself, and has very narrow slits in its periphery. With such a cap as shown in Fig. 24, the bran, sediments, etc., would tend to settle upon the top of the cap, enter beneath it and through the slits. The cone-shape of the top of this cap prevents the deposit of dregs thereon and the very narrow slits oppose the entrance of bran or sediment. While, for the sake of clearness, an old form of concentrator, _G_, has been shown, the concentrator, preheater for the wash, and condensers, to-day, are usually composed of bundles of tubes through which the vapors pass surrounded by water or the cool wash. These should be of bronze or copper and made without solder. The tubes should be capable of being taken out for cleaning or repairing. In many distilling apparatuses the distilling column and the rectifying column are in two parts, one beside the other. This overcomes the objection of having a very high column and also prevents the low wines, _i.e._, the weak alcoholic liquor after its first concentration, from passing into the wash as it would do with the continuous column. [Illustration: FIG. 26.--Steam Regulator.] In order that the amount of steam entering the column may be regulated, the column is usually provided with a steam regulator (Fig. 26); whose principle of operation may be easily under stood by referring to Fig. 22. It comprises an upper and a lower chamber _Z Z´_ connected by a central tube _K_ which projects down nearly to the bottom of the lower chamber. A pipe _W_ communicates with the steam chamber _R_ of the column and enters the chamber _Z_ above the level of the water contained therein. In the upper chamber _Z´_, is a float _X_, connected to the differential lever _T_ of a steam valve _T´_ which controls the inlet of steam passing through pipe _S_ to the steam chest _R_. The principle of operation is very simple. When the pressure in the steam chest _R_ becomes too great, steam in the pipe _W_ and chamber _Z_ forces the water therein up in tube _K_, thus lifting the float _X_ and closing the steam entrance valve _T´_. When the pressure of steam is low, the level of the liquid in _Z_ rises and liquid in _Z´_ runs into _Z_, the float _X_ falls opening valve _T´_ and allowing a greater flow of steam. As it is often desirable to change the pressure of steam in the column at various points in the operation, the best regulators are usually provided with means to that end. [Illustration: FIG. 27.--Gauge Glass for Regulatur.] In order to measure the output of the still, there is attached thereto a gauge glass (_J_ in Fig. 22), a diagram of which is shown in Fig. 27. This consists of a jar _A_ connected at its lower end at _b_ by an annular passage _B_ to a chamber _E_ from which proceed the taps _F_. Centrally through the passage _B_ passes a tube _c_ connected at its lower end to the pipe _C_ leading from the condenser. The tube _C c_ projects upward into the jar _A_ and is open at its upper end. Now the opening _b_ is of a certain size and it is obvious that it will carry off a certain amount of liquid when running full or the amount allowed to flow out by the exit tap _F_. If now, more than that quantity of alcohol is produced, the alcohol will rise in the jar _A_ until the rate of inflow and outflow is equal. If, however, the still is producing less than that quantity then the level of liquid in _A_ will gradually drop. Hence, by observing the level of the liquid in _A_ and its constancy or variation in level, it is possible to tell precisely how much alcohol is running per hour and if the rate is steady. The jar _A_ is provided with a cap _G_ whereby an alcoholometer may be inserted into tube _c_ for the purpose of testing the strength of the liquor. The taps _F_ are for the purpose of collecting the first runnings, the pure alcohol and the last runnings or "feints." These principles are also embodied in the apparatus designed by the Vulcan Copper Works Co., of Cincinnati, and illustrated in Fig. 28. The apparatus comprises the still, a wash heater and a condenser. The still is composed of a series of chambers from 12 to 24, the internal construction of which is shown in Fig. 29. Each chamber consists of a peculiarly perforated plate _A_, a drop pipe _B_, a seal _C_, into which the drop pipe from the plate above projects, and a central standard _D_. Returning now to Fig. 28, at the bottom of the column is a manifold _E_, with pipes _F_ and _G_ whereby either exhaust or live steam may be admitted. _H_ designates the discharge or slop valve, controlled by a float _I_ whereby a constant level of slop or spent wash is kept in the bottom chamber. [Illustration: FIG. 28.--Continuous Distilling Apparatus, with External Tubular Condenser. (_To face page 72_)] To the right of the column is seen the slop tester _J_ and hydrometer _L_, whereby the spent wash may be tested to see if the spirit is being properly extracted. The steam pressure is indicated by means of a float _N_ contained within a vessel _M_, a tally weight moving against a scale _K_, showing the pressure of steam entering through pipe _O_ and acting against water contained in vessel _M_. Each chamber is provided with a manhole plate _P_, and a try-cock _Q_, whereby the operation of each chamber may be tested. _R_ is a gage glass to show the level of the slop in the bottom chamber. At the top of the column are three rectifying chambers fitted with boiling pipes and traps _T_, which distribute the ascending vapor and boil out the low wines returned from the wash-heater or fore-warmer. [Illustration: FIG. 29.--Detail of Chamber, Continuous Still.] The heater consists of a shell enclosing a series of tubes extending into an upper and lower chamber. The wash or "beer," is pumped into the lower chamber of the heater, and passes upward through the tubes to the upper chamber from which is it carried by a pipe to the plate _A_ next below the rectifying plates. [Illustration: FIG. 30.--Detail of Perforated Plate _A_.] The vapor from the column passes into the middle compartment of the heater and surrounds the beer tubes. The vapors give their heat to the beer and are thus cooled, the low wines being condensed and flowing back onto the uppermost rectifying plate, while the highly vaporized portions pass out to the condenser. This is of the same general construction as the heater, the vapor being cooled and condensed to liquid by the tubes through which a constant current of cool water is passed. This enters at _U_ and passes out at _V_. These tubular condensers are particularly good as they may be easily cleaned. From the condenser the spirit passes to a discharge box _W_. A portion of the flow passes into a test tube _X_, provided with a hydrometer. A trap _Y_ and an air pipe _Z_ provide means for the escape of gas. As before stated, the form of perforations in the plates of a column through which the vapor pass upward through the beer or wash is particularly important. The steam must be thoroughly diffused through the beer, or else particles of mash are carried up, accumulate around the perforations, baking there and clogging them up. The clogging and eventual stoppage of the perforations prevent the agitation of the mash carried on the plate, and a layer of mash accumulates and bakes on the head, or plate, above. Thus the operating capacity of the still is reduced and a larger quantity and greater pressure of steam is necessary with consequent waste of fuel. [Illustration: FIG. 31.--Detail of Perforated Plate _A_.] It is necessary then that the form of perforation or trap through which the vapor ascends should be such that agitation of the beer shall be enforced in its movement across the plate, and that the steam shall be thoroughly diffused through the beer. In the Vulcan still above referred to, these results are accomplished by forming each perforation with a tongue, as shown in the fragmentary view of a plate, Figs. 30 and 31, the tongues of all the holes being directed towards the periphery of the plate. It is claimed that by this construction the steam is diverted forward and injected into the beer, throwing the beer into vigorous motion, completely diffusing the steam and accelerating the motion of the beer from the seal _C_ to the drop pipe _B_. [Illustration: FIG. 32.--Continuous Distilling Apparatus with Goose Separator. (_To face page 76_)] Fig. 32 illustrates another form of distilling apparatus manufactured by the same company, which is practically the same as the apparatus previously described except that it is provided with a "goose-necked" separator, interposed between the wash-heater and the enclosure. This consists of a series of convoluted tubes contained in a tank of cold water. The vapor from the heater passes into these convolutions. The heavier vapors are condensed therein and returned to the heater from which they descend into the column while the more volatilized vapors pass over into the final condenser. The _U_-bends at the bottoms of each convolution act like so many low wine chambers in the still shown in Fig. 9 the highly heated vapor continually bubbling through the condensed vapor in the _U_ bend and there becoming greatly enriched and concentrated. This apparatus, it is claimed, is applicable to the distillation of grain, molasses or cane juice and will yield 170 or 180 per cent., or the equivalent to 85-90 G. L. or 34-36 Cartier. [Illustration: FIG. 33.--Section of Gillaume's Inclined Column Still.] A distinctly modern type of still, though akin to the still shown in Figs. 19 and 20, is the inclined column of Gillaume, shown in section in Fig. 33 and in full view in Fig. 34. Gillaume in devising this form of apparatus had particularly in mind the distillation of thick washes, and the necessity of compelling a circulation of the wash. [Illustration: FIG. 34.--Gillaume's Inclined Column Still.] The bottom of the inclined column _A_ is divided by lateral extending, upwardly projecting plates or partitions _a_ forming a continuous channel through which the wash passes from side to side and from top to bottom and then out through a regulator. The upper plate of the column has downwardly projecting partitions _b_ which with the partitions _a_ form a series of traps. The steam enters at the bottom of the column into a reservoir, and in order to pass upward is forced beneath each partition _b_ and through the washer contained in the channels of the bottom. When it reaches the upper end of the column it has passed through a continuous series of wash-filled compartments containing a constantly moving current of wash. The vapors from the top of the column pass off to the wash heater or to a concentrator. In Fig. 34 is shown a form of Gillaume still designed to distill all sorts of liquids whether thin or thick. The wash is supplied from an overhead tank to a regulating tank _K_ from which a pipe _k_ leads to a regulating tap _m_. The wash re-ascends into the wash heater _B_ and when heated descends by pipe _F_ into the uppermost compartments of the column _A_. The vapor passes to the condenser _B_, by a pipe _H_, and the spent wash is discharged by a siphon _C_. In addition to the parts above referred to, _a_ designates entrance of wash into heater, _b_ exhaust test tube, _d_ steam entrance tap _G_ alcohol test glass, _G´_ exhaust test glass, _o_ valve for regulating strength of spirit, _O_ steam regulator, _p_ water entrance tap, _r_ exit tap, and _D_ the spent wash extractor. The Gillaume apparatus is particularly valuable for the production of industrial or agricultural alcohol. It is claimed that it is easily understood and operated even by unskilled labor, while it produces a large proportion of alcohol of a high strength. A view of a complete apparatus on a large scale is shown in the Fig. 40 in the chapter on rectification. CHAPTER V. RECTIFICATION. The product of the distillation of alcoholic liquors, which is termed _low wine_, does not usually contain alcohol in sufficient quantity to admit of its being employed for direct consumption. Besides this it always contains substances which have the property of distilling over with the spirit, although their boiling points, when in the pure state, are much higher than that of alcohol. These are all classed under the generic title of _fusel-oil_; owing to their very disagreeable taste and smell, their presence in spirit is extremely objectionable. In order to remove them, the rough products of distillation are submitted to a further process of concentration and purification. Besides fusel-oil, they contain other substances, such as aldehyde, various ethers, etc., the boiling points of which are lower than that of alcohol; these must also be removed, as they impart to the spirit a fiery taste. The whole process is termed _rectification_, and is carried on in a distillatory apparatus. As before stated, the wash as discharged into the still consists of alcohol mixed with water and a variety of impurities from which the alcohol must be separated. In order that the process may be better understood we will assume that a mixture of pure alcohol and water is to be operated on in place of the wash as above referred to. Distillation in this case is intended to deprive the water of its alcohol, the operation theoretically leaving water in one chamber and alcohol in another. This is accomplished by reason of the differences in the boiling points of water and alcohol. The alcohol vaporizes at a lower degree (173° F.) than water (212° F.) Thus the liquid at the end of the operation has been divided into two parts or _fractions_. This, however, is not a clean division for the reason that while in the beginning the vapors contain a large quantity of the more volatile alcohol, at the end they will contain a large portion of the less volatile water. The whole of the alcohol will be separated in this manner, but it will still be mixed with some water and in order to again divide the alcohol from the water the first distillate would have to be redistilled until at last the water is reduced to a minimum or entirely eliminated, if possible. But as it requires less heat to vaporize alcohol than water, so it also requires more cold to condense alcoholic-vapor than water-vapor. If then we pass the mixed vapors into a condensing chamber cooled to a certain temperature low enough to condense water-vapor but not the alcohol-vapor, then the water-vapor will fall down as water while the alcohol-vapor being uncondensed passes on to another chamber where its temperature falls to a point where it in turn condenses into liquid. In intermittent distillation, as by the simple still, the vapors of mixed alcohol and water at first contain a great deal of alcohol and a little water, then more water and less alcohol, and then a great deal of water and hardly any alcohol. It may be asked: "Why not take only the runnings rich in alcohol and leave the others?" The answer to this is that if this be done then _all_ the alcohol is not extracted from the wash and there is just that much loss. The solution of the problem is to get all the alcohol out mixed with the water that is inevitably with it and then redistill this result thus getting out (sifting away) some of the water, and again distill this result, and so on until only pure alcohol is left. This, however, is a very troublesome business and has been abandoned as a means of removing impurities such as water, the ethers, and fusel oil except by makers of whiskey, brandy and other beverage spirits, in favor of continuous distillation and continuous rectification. It will be seen from what has gone before that there are two means of separating alcohol and water; one by an initial difference in heating and by a further difference in cooling or condensing. It is on this foundation that the whole art of fractional distillation or rectification rests. While we have for illustration been considering a mixture of pure alcohol and water, the wash or liquid formed by the fermentation of grain, etc., contains a variety of ingredients of different boiling points, some more volatile than alcohol, some less. The fermented wash consists first of non-volatile or only slightly volatile matters, such as salts, proteins, glycerin, lactic acid, yeast, etc., and second, volatile bodies such as alcohol, water, various ethers, etc., fusel oils and acetic acid. When wash is distilled in the ordinary simple or pot still, the first part to come over consists of the very volatile matters,--more volatile than alcohol even,--that is, the ethers mixed with some alcohol. This is known as the fore-shot or first runnings, and is collected separately. When the spirit coming over possesses no objectionable odor, the second stage has begun. This running would be of the alcohol proper, getting weaker and weaker, however, as the running continues and this would be caught separately as long as it is of sufficient strength. At last would come the weak spirit containing much fusel oil. It is to be understood, however, that there is no defined line between these divisions. They graduate one into the other. The first and last runnings in the old practice were mixed together and distilled with the next charge. When a strong spirit was required, rectification would be repeated several times. It is customary, however, with the improved modern apparatus, to produce at the outset spirit containing but little fusel oil and at least 80 per cent of alcohol. This is then purified and concentrated in the above manner and afterwards reduced with water to the required strength. Another cause of the offensive flavor of the products of distillation is the presence of various acids, which exist in all fermented liquors; they are chiefly tartaric, malic, acetic, and lactic acids. The excessive action of heat upon liquors which have been distilled by an open fire has also a particularly objectionable influence upon the flavor of the products. The first operation in the process of rectification is to neutralize the above-mentioned acids; this is effected by means of milk of lime, which is added to the liquor in quantity depending upon its acidity; the point at which the neutralization is complete is determined by the use of litmus paper. In the subsequent process of distillation, the determination of the exact moments at which to begin and to cease collecting the pure spirit is very difficult to indicate. It must be regulated by the nature of the spirits; some may be pure 20 or 30 minutes after they have attained the desired strength; and some only run pure an hour, or even more, after this point. The product should be tasted frequently, after being diluted with water, or a few drops may be poured into the palm of the hand, and after striking the hands together, it will be known by the odor whether the spirit be of good quality or not; these two means may be applied simultaneously. [Illustration: FIG. 35.--Rectifying Still.] The process of rectification may be carried on in the apparatus shown in Figs. 35 and 36. _A_ is a still which contains the spirit to be rectified; it should be four-fifths full. The condenser _E_ and the cooler _G_ are filled with water. After closing the cocks _L_ and _I_, the contents of the still are heated by steam, which is introduced at first slowly. The vapors of spirit given off pass, by tubes _b_, above each plate _a_, of the series in column _B_, and escape through _C_ and _D_ into the condenser _E_, where they are condensed on reaching the lentils _d d´_, and return in a liquid state through pipe _f_ and connections _g g´_ to the upper plates of the column _B_. In these return pipes the liquid is volatilized, and constantly recharged with alcohol to be again condensed, until the water in the condenser is hot enough to permit the lighter alcoholic vapors to pass into the coil _c c c_, without being reduced to the liquid state. When this is the case, the vapors pass through _F_ into the cooler _G_, where they undergo complete condensation. Great care must be taken that the heat is not so great as to permit any of the vapors to pass over uncondensed or to flow away in a hot state; and also to keep up a constant supply of water in the cooler without producing too low a temperature; the alcoholic products should run out just cold. The highly volatile constituents of the spirit come over first, that which follows becoming gradually purer until it consists of well-flavored alcohol; after this comes a product containing the essential oils. The more impure products are kept apart from the rest and re-distilled with the next charge. Some hours generally elapse before alcohol begins to flow from the cooler. The purest alcohol is obtained while its strength is kept between 92° and 96° Baume, and the operation is complete when the liquid flowing through the vessel marks not more than 3° or 4° Baume; it is better, however, to stop the still when the backing or "faints" indicate 10°, because the product after this point contains much fusel-oil, and is not worth collecting. [Illustration: FIG. 36.--Section of Rectifying Still.] In order to cleanse the apparatus--which should be performed after each working--the still _A_ is emptied of water by opening the cock _Q_. The contents of the condenser are then emptied in like manner by opening the cock _J_, through which they flow upon the plates in the column _B_, and wash out essential oils which remain in them. These two cocks are then closed, and the door _U_ in the still head is removed. The water in the cooler _G_ is then run by means of pipe into the still _A_, so as partially to cover the steam-coil in the latter. After again securing the door _U_, a strong heat is applied, and the water in the still is well boiled, the steam evolved thoroughly cleansing all the different parts of the apparatus; this is continued for 15 or 20 minutes, when the heat is withdrawn and the still left to cool gradually. In the intermittent rectifying still above described the impure products are distilled with the next charge. In the apparatus as perfected and used in large distilleries or rectification plants, the division of the several products composing the phlegm or raw spirit is made at one time and continuously on the principle now to be described. It was stated in the beginning of this chapter that the various impurities in alcohol, the ethers, the water and the fusel oils, have each their own vaporizing point and each their own condensing point. As this is so, they may be separated from each other and from the alcohol on the same principle as we have seen that water is separated from the mixture of pure alcohol and water; that is, by fractionation, as it is termed, or by "sifting out" one body from another. [Illustration: FIG. 37.--Fractional Distilling Apparatus.] Thus in fractional distillation, each condenser or retort in the apparatus shown in Fig. 37, above acts as a sieve or trap, letting pass the most volatile substances but retaining those of a less degree of volatility. By passing the mixed vapor together through a good condensing medium the temperature of which is lower than the boiling point of the less volatile, but not so low as the boiling point of the more volatile the vapors of the less volatile liquid will be condensed, while the more volatile will retain their gaseous form. Thus by having a number of condensing mediums each one slightly lower in temperature than the other, the various vapors with their various points of volatilization will be successively condensed, allowing the passage of the more volatile vapors over to the condenser beyond. If we had mixed gravel and sand and desired to separate the gravel into assorted sizes and get the sand by itself, we would pass the mass through a series of sieves of gradually smaller mesh. The first sieve of course would catch all the largest pebbles, the next in size would let all the second sized gravel through, and so on until the final sieve would have separated the coarse sand from the fine. In this figure of illustration, the coarse pebbles may be taken to represent the water and the fusel oils which are mixed and partly tend to rise with the alcohol, and the alcohol may be represented as the gravel larger than the sand, and the fine sand as the etheric vapors. If this gravel were forced upwardly through a series of sieves gradually growing finer, it would be analogous figuratively to the upward passage of the vapors through a distilling column composed of plates or chambers; the water and fusel oils would be retained in the lower portion of the column and continually sent back there; the alcohol would pass into the upper chambers of the column and the ethers or fore-shots would pass out from the very fine sieve at the top of the column. The vertical chambers above each plate of the rectifying column are to-day used as the separate eliminating chambers referred to above. It has been found in practice that as before stated, each plate of a column contained upon it liquid of a certain temperature and above it vapors of a certain degree of vaporization. That is, in a continuous column fed regularly by condensation from above and supplied with a constant flow of phlegm, each plate carries upon it a liquid of constant composition relative to the boiling point of the fluid on that plate. As many extractions may thus be made from the various plates as there are different liquids to be isolated. Thus by tapping different portions of the column, vapors of different degrees of vaporization are found and may be carried off and the phlegm be thus fractionated. In the case of one column the first runnings or fore-shot would be found in the upper portion of the column to which they would have risen by reason of their degree of volatility. The last runnings or oils, aldehydes, etc., would be found in the lower portion of the column still mixed with the spirit, while upon the plates of the middle portion of the column would be found the vapor of the alcohol freed from the fusel oils and from the,ethers. It is understood, of course, throughout this description that the liquid being treated is not wash but phlegm; that is, the raw spirit containing the fusel oils, ethers, water and alcohol. Fig. 38 represents a simple rectifying apparatus designed for small or medium sized plants, and manufactured by the Vulcan Copper Works Co., of Cincinnati. The still is upright, with a chambered column above it, of the usual type. The chambers are fitted with a vapor boiling pipe and cap and a drop pipe, and each is provided with cocks whereby it may be drained for cleansing. Above the column is a separator, comprising a casing containing a series of tubes. The vapor from the column circulates around the tubes through which passes a current of cool water. The condenser is of the same construction as the separator and is provided with a gage glass and a draw-off cock. The operation is the same as in other simple rectifiers; part of the vapor from the column is condensed in the separator and passes back on to the upper plates, while the more highly vaporized portions pass over into the condenser. [Illustration: FIG. 38.--Rectifying Apparatus with External Tubular Condenser. (_To face page 94_)] The diameter of the still is large relatively to its depth so as to yield an economical and at the same time highly effective distribution of heat through the charge. This also affords an extended boiling area from which the vapor rises evenly and regularly, thus ensuring conditions peculiarly conducive to produce the best fractionating. The floor space required for this still and others of the same character built by this company is very compact and excessive weight on the top floor of the building is dispensed with. We have shown in Figs. 39 and 40 two forms of rectifying apparatus, one a twin column Barbet rectifier and the other a rectifier of the Gillaume type combined with inclined column still. [Illustration: FIG. 39.--Twin Column Barbet Rectifier.] In the twin column apparatus, Fig. 39, the first column or clarifier _A_ receives the raw phlegm and accomplishes the elimination of ethers. The clarified phlegm passes then to the second column where the alcohol is separated from the last runnings or fusel oil. In other words, the phlegm or impure raw alcohol is only raised to such a temperature in the first column as to drive off the very volatile constituents such as the ethers. These therefore pass off at the top of the first column into the condenser _C_, the retrogradation or condensed alcohol being returned to _A_, while the boiling phlegm taken from the middle of the column and still containing the aldehydes, oils, etc., is conducted by a pipe _E_ to the second column _B_ wherein the last runnings or amylic oils, etc., are separated from the purified spirits. The vapors in this column are carried to the condensers _D_ and _F_ and from there to a refrigerator _G_. The fusel oils are extracted from the plates slightly below the center of the column and are carried to an oil concentrating apparatus _H_. In the most complete forms of apparatus used to-day, there is a variation of this construction. The first runnings, middle runnings and the last runnings are each led off from the main column to separate coolers, condensers, etc., and the purified result from each of these columns is in turn led to a trunk rectifier common to all where the product is redistilled and entirely freed from impurities. This gives a very high grade of alcohol by a process practically continuous. At the same time the impurities are not returned to the first or main column to contaminate the vapors therein and add to the amount of fusel oils contained on the lower plates. In construction of this character there is a very large saving in the cost of the fuel and the result is much better in every way. [Illustration: FIG. 40.--Gillaume's Rectifier and Inclined Still.] FIG. 40.--GUILLAUME'S DIRECT DISTILLATION-RECTIFICATION APPARATUS FOR "AGRICULTURAL" DISTILLATIONS. _A_ Distilling Column. _a_ Tank for Wash to be Distilled. _b_ Cold Water Tank. _C_ Rectification Column. _D_ Final Purification Column. _I_ Wash Heater. _K_ Condenser. _K´_ Refrigerator of Ethers. _O_ Refrigerator for high-grade Alcohol and the First Runnings. _Q_ Refrigerator for the Products of the Last Runnings. _R_ Spent Wash Extractor. _r_ Siphon Carrying off Spent Wash. _S_ Steam Regulator. _s_ Tap and Pipe for Carrying Wash to Distilling Column. _U_ Water Regulator. _u_ Taps for the Extraction of Intermediate Impurities. _V_ Receiver Accumulator. _v_ Tap for the Extraction of the Last Runnings. _X_ Test Glass for the High-Grade Alcohol. _Y_ Test Glass for First Runnings. _Y´_ Test Glass for Last Runnings. _Z_ Test Glass for Determining Degree of Exhaustion of Spent Wash. In this apparatus the still proper is of the form heretofore described on page 78. The liquid to be distilled enters at the top of the inclined column _A_ and descends to the base thereof. The alcoholic vapor rises through the column and passes off from the head thereof into the rectifying column. At the head of the column _A_ it has a strength of about 40° to 50° F. The column _C_ is supported upon an accumulating reservoir _V_ which acts to regulate the flow of the phlegm through the rectifying column and prevents too great an exhaustion of the plates of the column. It acts as a reservoir to contain any excess of phlegm or to supply an additional amount of phlegm to the plates when they have become nearly exhausted. The oils or products of the last running accumulate at the base of the column, and are carried off to their special refrigerator _Q_. The alcoholic vapors concentrate while rising in the column and quickly attain a strength of 92° or 94° F. At a height within the column corresponding to the plates whereon alcohol of that strength is to be found, there are provided three taps _u_ whereby the middle runnings or medium grade of alcohol may be drawn off, which have a maximum concentration of 92° and 94° F. Above these middle plates the alcohol vapors are completely separated from the products of the "tail" that is the aldehydes, amylic oils, etc., and at the upper portion of the column there is found the condenser _K_ which separates the products of the head; that is the first runnings from the alcohol which has passed over with such products to the condenser. The alcohol so separated is completely rectified in the column of final purification _D_ and the finished alcohol is cooled in the refrigerator _O_ below the column of final condensation. In this apparatus the gauge glasses which regulate the exit of the various alcohols and mixtures are controlled by taps having verniers or scales whereby they may be very carefully adjusted, to regulate the relative proportion of the various products. This apparatus is able to produce about 75 or 80 per cent. of first-class alcohol, 10 to 15 per cent. of middle class alcohol, and 5 per cent. of ethers and 5 per cent. of fusel oils, the alcohol produced being about 96° Cartier. The alcohol is thus obtained in one single operation and with, it is asserted, only a very small loss in rectification. The apparatus is claimed to be so simple that it may be operated even by unskilled farm labor. It is also claimed that purification by chemical treatment or filtration is unnecessary with the Guillaume apparatus. It may be stated, however, that the Guillaume system has many opponents. The capacity of the rectifying apparatus has a good deal of influence upon both the quantity and the quality of the spirit obtained. Besides being much more difficult to manage, a small apparatus will not yield so large a proportion of spirit as a more capacious one, nor will its products be of equally good flavor. The proportion of alcohol which may be obtained from a successful rectification is very variable; it depends upon the nature of the spirit rectified, the method of extracting the sugar, and the manner of conducting the distillation; it will also be in inverse proportion to the quantity of fusel-oil contained in the raw spirit. The average loss of pure alcohol during the process of rectification is generally estimated at about five per cent. In addition to the rectifying as above described, alcohol may be further purified by filtration through charcoal, by chemical means or by electrolysis. The last two methods have not so far been successful. The chemicals used merely act to disguise the disagreeable taste or smell of the spirit and do not really purify. They but substitute one impurity for another. The agents used are many--sulphuric and nitrate acids, soaps, oils and fats soda, lime and potash have each and all been tried, but with no permanent success. As agents for disguising the taste of new and raw spirits, alcoholic extracts of fruits have also been used. Purification and aging by electricity has been tried many times and in many different forms, but so far has not been commercially practicable. Filtration still remains the best and simplest adjunct to the rectifier. In small plants, a filter bed several feet in thickness of bone black or beachwood or charcoal is used, laid upon a foundation of gravel in a filtering tank. In the larger plants a series of these vats is used, the charcoal being used in lumps varying from 1/4 to 1/2 inch in diameter. Two different views of the purification by charcoal are held--one that the charcoal purifies by chemical means, the other that it is purely a physical filtration agent. After filtration the charcoal must be steamed to recover the spirits retained therein and should be heated to a red heat every now and then to cleanse and regenerate it. CHAPTER VI. MALTING. Wheat, oats, rye, potatoes, and other amalyceous or starchy materials contain starch insoluble in water and to render it soluble, and to change the starch to maltose they must be mashed with a certain small proportion of malt,--or grain in which germination has been artificially induced and then interrupted at a certain stage. This increases the diastase contained in the grain so germinated, and this diastase is able to transform starch into soluble form. Hence, malted grain gives lightness and liquidity to the wash, and prevents the starch falling to the bottom of the mash tub or "back," and also prevents the starch falling to the bottom of the still and consequent burning. While all varieties of grain including rice are suitable for the preparation of malt, barley is preferred to all others, and is most commonly used. =The best barley= for malting is that having the following characteristics; a thin skin; a mealy interior; grains of a uniform size; of the greatest weight; which has been stored for three months. Barley on harvesting has but slight germinating power. The reason for the uniformity in the grains lies in necessity of a uniform steeping of the grain so that the period of germination shall be the same for the whole mass. Like all materials for distillation, the barley should be thoroughly cleaned of impurities--not only dust, seeds and weeds, but fungi and bacteria. This may be partly accomplished in the ordinary fanning mills, usual on farms, but a better machine would be a "tumbling box" of wire mesh. This is inclined, so that grain put in the upper end, will pass downward to the lower, being thrown about as the box or cylinder is rotated. The dust, seeds, etc., fall through the meshes of the wire as do the smaller grains. After this cleaning, the barley should be thoroughly washed. This may be either done in the steeping vat itself--and the water afterwards drawn off--or in special machines. If the barley be allowed to soak in water for a day or two, the later washing will completely cleanse it. This preliminary cleaning is most important as impurities reduce the germinating power of the grain, as well as introduce bacteria inimical to fermentation. Washing in some instances is done by forcing compressed air into the steeping tub, thus violently agitating and swirling the water therein, and washing away the impurities. Another method is by passing the steeped grains along a trough supplied with moving water, the trough being provided with rotary agitators. Any fairly ingenious mechanic could devise a capable cleansing machine. Care being taken that it shall not injure the grains. After cleansing, the barley should be steeped. For this purpose tanks of metal or cement are to be preferred to wood. All vats should be kept thoroughly cleaned by frequent scrubbing with lime water. The barley placed therein should at all times be entirely covered with fresh water to a depth of a few inches, and for the first few hours the grains should be carefully stirred in order that no grain should escape wetting. At the end of that time the still floating grains should be removed. In 36 or 48 hours the grain will usually be sufficiently steeped,--but this varies with weather conditions. The warmer the water the quicker the steeping, and in winter proper steeping may not be accomplished before four or five days. A simple test is to rub the grain strongly between the hands, If it is entirely crushed, and no solid matter is left it has been steeped sufficiently. Barley should be capable of compression lengthwise and the hull should become easily detached. It should be easily bitten, and not crack under the teeth. In order to prevent fermentation in summer, it is well to renew the water a few times during steeping. Over steeping is worse than under steeping. After the barley is in proper condition the vat or tank is opened and the water drained away. The draining should be complete, and therefore the grain should be left to drain about 12 hours. =Germinating.= The grain is now taken to the malting floor. In practice it is well to locate the steeping vat above the malting floor, so that the steeped grain may be run down on to the floor without inconvenience. It is best to first spread the grains out on the floor to a depth of a few inches in order that it may somewhat dry out. This is not necessary when it has not been steeped to a great extent. After 10 or 12 hours of drying, the grain is placed in a heap until warm to the touch, which may occur in from 12 to 24 hours. It is then disposed in a layer from eight inches to 20 inches thick. This is called the "wet couch." The lower the temperature the thicker the couch should be. It should be turned every six or eight hours in this stage. The heat so germinated after 25 or 30 hours produces at the end of each grain a small white rootlet. The grain in the middle of the layer is the first to sprout, as it is the warmest, hence the couched grain should be frequently turned so as to give all the grains a uniform heat, and a uniform germination. At this period the grains beneath the surface are dampish to the touch. The height of the couch is now successively lessened to layers of from six to two inches called "floors," the height of each floor of course depending on the temperature, as before. It is to be understood that the growing grain requires both dampness and air, hence the "floor" should not be thinned so rapidly as to deprive it of moisture, and the barley should be turned at least twice a day to give each grain a proper aeration. During this period the small white rootlets or radicals should be white and shiny. If they begin to fade, it is a sign that they lack water and the grain should be sprinkled. Germination usually requires from a week to ten days, or sometimes two weeks, depending on the previous steeping, the quality of the grain and the temperature. When the fibers or rootlets of the grain are about equal to the length of the grain, germination is complete. It used to be considered that malt was in its best condition in eight or ten days. To-day, however, "long malt" is used,--requiring a germinating period of twenty days, being frequently moistened and turned during this time, and the temperature being kept at 65° F. This malt is very strong in diastase. The effect of germination is to produce a change particularly favorable to mashing. The barley becomes sweetish, the gluten is partially destroyed and what is left is soluble. Thus the fecula or starch is set at liberty and free to be acted on by the yeast used in fermenting. March is the best month in which to malt; and while the malt is best used immediately, it can not be kept in its green state and must be therefore dried for future use. =Drying.= This is accomplished either in the air of a warm, dry room in hot weather, or by means of a drying kiln. In the first process the malt is spread in a thin layer and frequently turned. In the second the grain is spread out in a layer from eight inches to a foot thick on the grain floor of the kiln. Beneath the grain floor a fire is maintained. In the beginning the temperature of the drying floor should be about 85° F., but this is increased gradually to about 104° F. until most of the moisture has been removed. The heat is then raised to from 120° F. to 130° F., thus completely drying the grain. The germinated green or dried barley is called malt. It is of good quality when the grain is round and flowery; when it crumbles easily and when its taste is sweetish and agreeable. Pale malt or that which has been hardly altered from its original color is the best for distillation. Before the malt can be used it should be screened so as to remove the rootlets. Two hundred and twenty lbs. of barley should yield from 275 to 350 lbs. of green malt, about 200 lbs. of air dried malt, and from 175 to 190 lbs. of kiln dried malt. In large plants malting is now so carried on that the steeping germination and drying are all accomplished in one vessel or container, by one continuous operation. This vessel is commonly in the form of a drum of sheet iron, revolving at a very slow speed. Moist air is introduced and the carbonic acid laden air withdrawn. After germination the malt is dried by passing in dry air at the proper temperature. As these systems are only adopted to large distilleries, using expensive machinery, further reference to them is not considered necessary in this volume. Previous to use the malt must be finely ground or crushed either before or after mixing with the materials to be mashed. It is not necessary or advisable that the malt be reduced to flour. The use of malt with other materials in order to form a fermentible mash, will be considered in the chapters on specific mashes. CHAPTER VII. ALCOHOL FROM POTATOES. In certain countries, as for instance Germany and France, potatoes form the greatest source of alcohol, particularly for industrial purposes. With the possible exception of corn and beets they will probably be most used in America. The best potatoes for distilling are those which are most farinaceous when boiled. In other words, those which are "mealy" and most appetizing. These give the largest yield of alcohol per bushel. The best season of the year in which to use potatoes is from October to March, when they germinate. The potatoes should be kept in dry cellars, and at even temperatures, warm enough to prevent freezing and yet not so warm that they will rot or sprout. Diseased potatoes may however be used, if they have not been attacked by dry rot, though they are not so easily worked. Frosted potatoes may be also used, but they must not have been completely frozen. Before being steamed, the potatoes should be washed, either by hand or by a machine, care being taken to remove all stones, clods of earth, and other foreign substances which might impede the subsequent operations. There are three main methods of saccharifying the fecula or starch of the potato. The first and most important by reducing the tubers to a pulp, and malting the entire mass. The second and third, by rasping the potatoes and so separating the fecula or starch grains from the mass, and then making a thin liquor or wash containing this fecula. Originally, in the first process, the washed potatoes were submitted to the action of boiling water, but later cooking by steam at a temperature of 212° F. was used, as being much more convenient to handle and more effective in action. The object of steaming is to break the coating and reduce the contents thereof to a pasty condition, wherein the starch is more effectively acted on by the malt and yeast. Ordinary steaming does not, however, render the pulp sufficiently pasty; some of the starch remains undissolved and is lost, hence in the modern practice, steam is turned into the steaming vat under a pressure of three or four atmosphere (45 to 60 lbs. to the square inch). High pressure steaming will be later described but the simple and older method of mashing and apparatus therefor, used prior to 1870, was as follows: Fig. 41 shows a section of a steaming vat. This consists of a conical wooden tub _H_ provided at its top with a suitable cover _O_ having a trap or door _P_ for putting in the potatoes. This as shown, consists of a hinged lid, having a button _p_ or other fastening means. This lid and cover should be of course steam tight, and it would be better to have it clamped down by a screw clamp than held by a button. Somewhat above the bottom of the vat, a steam inlet pipe _I_ enters, connected at its other end by a coupling _i_ with a suitable steam generator (see Fig. 43), Preferably the outlet of this pipe is screened by a perforated plate _M_ so that it may not be clogged by the pulp. It is also best that a filling piece be placed at the junction of the bottom with the sides in order that there be no sharp corner from which the pulp may not be easily cleaned out. [Illustration: FIG. 41.--Steaming Vat for Potatoes.] The bottom of the vat may either have a discharge door at the side as in Fig. 44 or at the bottom, as in Fig. 41. An under side view of the latter construction is shown in Fig. 42. The bottom of the vat is made in two parts or doors _J K_. These are held closed by a transverse bar _L_ inserted at its end into a stirrup _l´_ and supported at its other end by a button _l_, or other means. While various forms of steam generators may be used, Fig. 43 shows a simple construction well adapted to the needs of a small distillery. _D_ designates the brick work of a furnace, and _A_ the boiler. This is so set that an annular space _E_ surrounds the sides of the boiler, through which the products of combustion must pass. [Illustration: FIG. 42.--Bottom of Steaming Vat.] The head of the boiler is connected by a pipe _B_ and collar _b_ to the steam inlet pipe _I_ of the steaming vat, heretofore described, as by the collars _b i_. A filling tube _C_ enters the boiler and projects nearly to the bottom, and the water outlet-pipe _F_ with cock _f_ leads off from the upper water line. The tube _C_ forms also a safety valve, for if the steam pressure becomes too great in the boiler and connected vat, it will force water up and out through the tube. If, however, the water falls below the level of the lower end of the tube, steam will issue and warn the attendant that water is too low. It would be best however, to provide a steam gauge, whereby the pressure of steam in the boiler and vat could be accurately indicated. [Illustration: FIG. 43.--Steam Generator.] It is to be noted that when steamed the potatoes will swell and occupy more space and that the steam vat should therefore not be much more than two-thirds filled with potatoes. With the steaming vat above shown, the potatoes are delivered mixed with a considerable quantity of water, but a better plan is to have a perforated false bottom to the tub, whereby the condensed water may be carried away, the steamed potatoes remaining behind. [Illustration: FIG. 44.--Potato Steamer and Crusher.] Two hours of steaming should reduce the potatoes to proper condition, which may be tested by introducing a pointed iron rod through a suitable aperture, normally kept closed. If the rod passes freely inward, the potatoes are done and may be discharged into the crusher, shown in Fig. 44. In this Fig. the steaming vat _A_ is shown mounted above the crusher. A pipe _B_ with cock _b_ leads to the steam generator. The steamed potatoes are shoveled out through the door _a_, which is usually held closed by means of the clamps or buttons _a´ a´´_. =The crusher= consists of a hopper _C_ whose bottom fits closely against two adjacent smooth faced rolls _H I_ of iron. These are driven by gears _D E_. The shafts of these gears have cranks _d d_ whereby it may be operated. These gears are unequal so that the rolls shall move at different speeds, and thus one will have a grinding action against the face of the other. A counter weighted scraper _e_ bears against the face of the roll. The crushed potato pulp passes between the rolls and into a bin beneath, having adjustable walls made of boards _F_, sliding in suitable guides _f_, from which the pulp may be shoveled into the mashing tank or "back." The crusher might, however, be arranged to deliver immediately into the mashing tank, if the latter is provided with means for stirring the delivered pulp. The pulp or paste thus made is now placed in a vat, holding about 650 to 850 gals., in which the saccharification takes place. About 2200 lbs. of the crushed potatoes and 155 lbs of broken malt are introduced, and immediately afterwards water is run in at a temperature of about 97° F. to 104° F., the contents being well stirred with a fork meanwhile. The vat is then carefully closed for half an hour, after which boiling water is added until the temperature reaches 140° F., when the whole is left for three or four hours. The process of fermentation is conducted in the same vat. Alternate doses of cold and boiling water are run in upon the mixture, until the quantity is made up to 700 or 775 gallons, according to the size of the vat, and so as finally to bring the temperature to 75° F. or 79° F. Five and a half to six gallons of liquid brewer's yeast are then added, and fermentation speedily sets in. This process complete, the fermented pulp is distilled in the apparatus devised by Cellier-Blumenthal (see Fig. 15) for distilling materials of a pasty nature; the product has a very unpleasant odor and taste. The process above described is the old method of pulping the potatoes by using steam. Under the modern method, however, and with modern apparatus, in preparing potatoes for distillation in large quantities, the steaming of the material is accomplished at one time and under a high steam pressure. The apparatus is also used for the preparation of corn, potatoes and other starch-containing substances. There are many apparatuses which have been devised for the purpose, but the principle on which they work is practically the same in all cases. They comprise a closed tank, fitted with stirrers, agitators, or other means for mixing and comminuting the contents, means for admitting steam under pressure, means for cooling the mixture to the proper mashing temperatures, and means for forcing the steamed material out of the tank. [Illustration: FIG. 45.--Bohn's Steamer and Crusher.] =The Steamer.= One of the earliest forms of steamer was that of Hallefreund devised in 1871, and adapted for working on a large scale. A modified form of the apparatus known as Bohn's steamer and masher is illustrated in Fig. 45. This comprises a steaming cylinder _A_, having a securely closed opening _D_ for the introduction of the potatoes. Centrally through the cylinder passes a hollow shaft _B_, which is rotated by the power pulley _K_. Hollow arms _b_ project radially from the shaft _B_. These act as mixers of the mash and as coolers. The shaft _B_ at one end is connected to a cold water supply pipe _M_ as by a coupling _C_, the supply pipe being provided with a cock. _E_ designates a discharge opening for the mash. A pipe _F_ provides for the entrance of steam into the cylinder. _G_ is a pipe through which malt is put in to be mixed with the pulp. _L_ is a steam gauge and _J_ a safety valve. _H_ designates a water pipe. For the relation of the steamer to other apparatus, see Fig. 1. In operation the potatoes are placed in the cylinder _A_ and submitted to the action of steam at about 46 lbs. to the square inch, and at a temperature of from 266° F. to 275° F. When disintegrated, the steam is blown off, and the potatoes crushed by rotating the stirring shaft. As the pulp must be reduced from 275° F. to 149° F., the mashing temperature, cold water is forced into the stirrer which chills the blades and quickly cools the mass. In the vacuum mash cooker shown in Fig. 1, the steaming cylinder is partly filled with hot water at 140° F. to 150° F. The potatoes to be mashed are fed into the cylinder whole. The steamer is then closed and steam admitted while the mash is stirred until a pressure of 65 pounds is reached, when the dissolution of the starch is complete. The steam is then exhausted and the temperature reduced to 212° F. To reduce this temperature to the proper saccharifying point of 145° F., the hot air is exhausted. Barley malt meal in the proportion of 6 to 10 per cent. is used. This has been previously mixed with cold water in the small grain masher. The malt is admitted to the cylinder and thoroughly mixed with the potato, when the mixture is withdrawn into a drop tub, where it is still further stirred. It is then cooled as described on page 15 and then fermented. While the crushed potatoes are being cooled and stirred, a mixture of green malt with water is prepared in an adjacent vat, and when the pulp in the cylinder has been reduced to 149° F. the malt mixture is introduced into the cylinder through the pipe _G_, and thoroughly mixed with the crushed potatoes. The mass is now left to saccharify; the stirrer being operated at intervals throughout this period. This machine might be readily modified so that the steam should enter through the stirrers, by tubes attached to the arms, then the steam may be shut off and cold water sent into the arms themselves to cool the mash. A variety of steamer used in various forms and modifications in all the larger distilleries, is known as the Henze steamer, Fig. 2. In this, there are no stirrers. The cylinder is conical, and has steam pipes leading to the interior. At the end of its cone-shaped bottom it terminates in a blow-off tube, having in it a grate formed of sharp-edged bars. In operation, steam is introduced at a pressure of one to two atmospheres until the potatoes are cooked. More steam is then suddenly admitted at high pressure and the softened potatoes forced through the grating at the bottom and into the mashing apparatus in a finely divided state. In steaming under pressure it is best that the safety valve be so regulated that the steam will constantly blow off as this action keeps the potatoes in motion and facilitates disintegration. Care should also be taken to see that everything about the apparatus is in good condition, as in working under the high pressures used in the last apparatus there is liability of explosion. Rust should be particularly guarded against. With this apparatus a preparatory mash vat is used into which the contents of the steamers are blown out, malt and water to form milk having been previously let into the mash vat. Blowing out is accomplished in 45 or 50 minutes at 130° F. and about one-sixth of the charge in the steamer is retained in the steamer. The mash in the vat is stirred and cooled and the remainder of the mash blown in raising the temperature to 145° F. when the mash is left to stand from half an hour to an hour. With heavy mashes, rich in sugar, even higher temperatures than 145° F. can be used for saccharifying. The processes of crushing and saccharifying, above referred to, which are almost entirely used to-day, require steam. The following methods provide for the isolation of the fecula or starch, without steam and the production of a wash of a more watery consistency, therefore easier to handle in ordinary stills, and with less liability to burn. Two operations are necessary by this method: First, rasping, or reducing the potatoes to a finely crushed and pulpy condition by means of a machine described in the chapter on Beet Mashing; and second, the separation of the fecula. To this latter end the potato pulp is placed on a sieve, having side walls and net work of horse-hair, which is placed over a suitable tub. Water is run gradually through the pulp and sieve, while the pulp is rubbed up by hand. When the water comes through clear, then all the fecula of the pulp has been washed out, and the refuse left in the sieve can be thrown aside or used as a food for cattle. =For a mashing tub= of say about 32 bushels capacity, the fecula from about 800 lbs. of potatoes is used. This is deposited in the mash tub with sufficient cold water to form a fairly clear paste. About twice as much water as fecula will bring the paste to proper consistency. This mixture should be constantly stirred as otherwise the fecula will sink to the bottom. About 40 gallons of boiling water are then added gradually. The mixture has at first a milky appearance, but at the last becomes entirely clear. This liquid is mashed with about 45 lbs. of malted barley or Indian corn, ground into coarse flour. In ten minutes the mixture will be completely fluidified. It is then left to subside for three or four hours when it will have acquired a sweetish taste and be what is termed as "sweet mash." The fluid is then further diluted by the addition of sufficient water to give about 290 gallons of wash. Two or three pints of good yeast will bring this mixture to a ferment. A less laborious method of accomplishing the same result is that at one time used in English distilleries. In this a double bottom tub is used, something like that shown in Fig. 41, the upper bottom of which is perforated, and raised above the solid lower bottom. A draw-off cock opens out from the space between the two bottoms. Assuming that the tub is of 220 gallons capacity, then from 2 to 20 lbs. of chaff are spread over the perforated bottom and pulp from 800 lbs. of raw potatoes placed on that. This is thoroughly drained for half an hour, through the draw-off cock. The pulp is then stirred while from 90 to 100 gallons of boiling water are added gradually. The mass then thickens into a paste. The paste is mashed with about 65 lbs. of well steeped malt, and the liquid left to subside for three or four hours. It is then drained off through the perforated bottom into a fermenting back or tub. For this amount of material the back should be of about 300 gallons capacity. =The leavings= left in the preparatory tub still contain considerable starch, and after they are well drained they should be mixed with from 50 to 55 gallons of boiling water. The mixture is then agitated and drained off into the fermenting back. The sediment left is again sprinkled with water, this time cold, which is drained off into the back. This completely exhausts the husks left on the upper bottom. By this process 200 lbs. of potatoes should produce something over 12-1/2 gallons of spirit. The objection to the last method described is that the spirit so obtained is unpleasant to taste and smell, but this would probably not be an objection for industrial uses. The only means of obtaining alcohol of good quality from potatoes is to extract the starch separately and then convert it into sugar. This saccharification of the starch may be accomplished by sulphuric acid or by the action of diastase. By the first of these methods the potatoes are disintegrated in such an apparatus as the Bohn steamer described on page 118. A mixture is made of one-third potatoes, two-thirds water, and onetenth part of sulphuric acid. The mixture is steamed for six or eight hours under pressure. The mash is then cooled and the acid neutralized by milk of lime. It is then fermented. By the second and preferable method, dry or wet potato starch is used, which is malted, and the saccharine solution fermented with yeast. The proportions and method for a vat of say 800 gallons capacity are as follows: Two hundred and sixty-five gallons of water are mixed with 1100 lbs. of dry or 1650 lbs. of moist starch. This mixture is well agitated, and 450 gallons of boiling water run in, together with 165 lbs. of malt. The whole is then stirred energetically and left to saccharify for three or four hours. The saccharine solution thus formed must be brought to 6° or 7° Baume, at a temperature of from 71° to 75° F. To this is then added 1-1/100 lbs. of dry yeast for every 220 gallons of "must." Fermentation is soon established and usually occupies about 36 hours. After remaining at rest for 24 hours the "must" is distilled. From each 220 lbs. of starch there should be a yield of about nine gallons of alcohol, at 90° F. The fermentation of the potato mash is carried on as described in Chapter II. For the preparation of malt see Chapter VI. CHAPTER VIII. ALCOHOL FROM GRAIN--CORN, WHEAT, RICE, AND OTHER CEREALS. The different cereals constitute a very important source of alcohol in all countries, particularly of course for use in the manufacture of whiskey and gin. All cereals contain an abundance of starchy substance which under the influence of diastase,--that is, malt,--is converted into fermentible sugar. The quantity of sugar and hence the yield of alcohol differs widely. The following table shows the results obtainable by good workmanship. 220 lbs. Wheat gives 7.0 gallons pure alcohol " " Rye " 6.16 " " " " " Barley " 5.5 " " " " " Oats " 4.8 " " " " " Buckwheat " 5.5 " " " " " Corn (Indian) " 5.5 " " " " " Rice " 7.7 " " " In addition to these there are other raw materials containing starch which are sometimes used, as millet (55 per cent starch), chestnuts (28 per cent.), and horse chestnuts (40 per cent.). The last is very difficult to work however. Rice, wheat, rye, barley and corn are more frequently employed than other grains. Wheat gives a malt which is as rich in diastase as barley. Barley and buckwheat are added to these in some proportions. Oats, owing to their high price, are rarely used. Rice, of all the grain is the most productive to the distillers, but on account of its value as a food is not much used for the production of alcohol, unless damaged. Corn is the cereal most largely used for the production of industrial alcohol. Great care should be exercised in making choice of grain for fermentation where the best results are desired. Wheat should be farinaceous, heavy and dry. Barley should be free from chaff, quite fresh and in large uniform grains of a bright color (see Malting, Chapter VI). Rice should be dull white in color, slightly transparent, without odor, and of a fresh, farinaceous taste. The flour or farinaceous part of grain is composed of starch, gluten, albumen, mucilage, and some sugar. The following table gives the proportions of these substances in the commonest grains. Under certain conditions the albumen or gluten in the grain has the power of converting starch into saccharine matter. This is better effected by an acid such as sulphuric acid, or by a diastase. This latter substance is a principle developed during the germination of all cereals but especially of barley. It has the property of reacting upon starchy matters, converting them first into a gummy substance called dextrine, and then into glucose or grape sugar, see Chapter II. The action of diastase upon starch or flour made into a paste is remarkable, 50 grains of diastase being sufficient to convert 220 lbs. (100 kilogrammes) of starch into glucose. The rapidity of this change depends on the quantity of water employed, and the degree of heat adopted in the operation. TABLE IV. PROPORTIONS OF STARCH, GLUTEN, ETC., IN PRINCIPAL GRAINS. Column A = Grains. Column B = Starch. Column C = Gluten and other Azotized Substances. Column D = Detrine, Glucose and similar Substances. Column E = Fatty Matter. Column F = Cellulose. Column G = Inorganic Salts. (Silica, Phosphates &c.) -----------+-- ----+--------+-------+-----+---------+------ A | B | C | D | E | F | G -----------+-------+--------+-------+------+--------+------ Wheat }| 65.99 | 18.03 | 7.63 | 2.16 | 3.50 | 2.69 (average }| | | | | | of five }| | | | | | varieties)}| | | | | | Rye | 65.65 | 13.50 | 12.00 | 2.15 | 4.10 | 2.60 Barley | 65.43 | 13.96 | 10.00 | 2.76 4.75 | 3.10 Oats | 60.59 | 14.39 | 9.25 | 5.50 7.06 | 3.25 Indian Corn| 67.55 | 12.50 | 4.00 | 8.80 | 5.90 | 1.25 Rice | 89.15 | 7.05 | 1.00 | 0.80 | 1.10 | 0.90 -----------+-------+--------+-------+------+--------+------ Inasmuch as barley germinates very readily, and develops a larger proportion of diastase than any other grain, except wheat, it is generally used as a producer of diastase. Barley germinated according to proper methods is called malt, and its preparation is fully described in Chapter VI. There are many methods of preparing grain for fermentation, but all use at least two of the following operations:--grinding, gelatinizing, steeping, or steaming, mashing saccharifying. =Grinding.= Where cookers or the Henze steamers are not used every form of grain should be crushed or ground into a coarse flour. This is in order that the starchy interior may be easily acted on by the diastase. If the grain is not to be mixed with malt later it must be ground more finely so that it may be thoroughly penetrated by the water. The grains should not be ground except as required, as ground grain is liable to heating and consequent loss of fermentability, and is also liable to become musty, in which condition it loses much of its fermentability. =Steeping.= This operation is best carried on in vats or tanks of iron or cement, for the reason that wood absorbs impurities, which are communicated to the grain, thus lessening its germinative power. Wooden vats should be thoroughly scrubbed after use, and be kept continually whitewashed. The steeping tub should hold about two-thirds more than the amount of ground grain to be steeped. Steeping is affected by pouring on to the crushed grain hot and cold water in such quantity that after 10 minutes or so of brewing the mixture will have a temperature of 75° to 95° F. This warmth makes the water more penetrating. The water should not be poured in all at once, but a little at a time, until the grain is covered to a depth of three or four inches. Care should be taken not to let the temperature get too high, not above 95° F., as a temperature above that point kills the germinating power. The mixture of crushed grain and water is now stirred for 10 minutes and then left to subside for half an hour. It is then stirred again and the mixture left to steep for 30 or 40 hours, depending on the temperature of the atmosphere, the dryness of the grain, and the character of the water. In very warm weather the water should be changed every few hours by running it off through a hole in the bottom of the tub and running in fresh at the top. This prevents fermentation setting in prematurely. When the grain swells, and yields readily between the fingers it has been sufficiently steeped, and the water is run off. This is an old method of gelatinizing grain, but a better is by the use of cookers or high pressure steamers as described for potatoes. =Mashing.= This consists in mixing the coarse flour with malt and then by means of certain operations and mechanisms bringing it to a condition most favorable to fermentation through the action of yeast. The mixing of the raw flour with barley or other malt effects the conversion of the starch of the grain into maltose. The yeast afterwards converts this maltose into sugar. =Saccharifying.= To effect the action of the diastase of the malt on the grain, in the old methods, boiling water must be poured into the vat until the temperature of the mass reaches about 140° to 168° F., the whole being well stirred meanwhile; when this temperature has been reached, the vat is again covered and left to stand for four hours, during which time the temperature should, if possible, be maintained at 140° F., and on no account suffered to fall below 122° F., in order to avoid the inevitable loss of alcohol consequent upon the acidity always produced by so low a temperature. In cold weather the heat should of course be considerably greater than in hot. It should be also remarked that the greater the quantity of water employed, the more complete will be the saccharification, and the shorter the time occupied by the process. Having undergone all the above processes, the wash is next drawn from the mash tub into a cistern, and from this it is pumped into the coolers. When the wash has acquired the correct temperature, viz., from 68° to 78° F., according to the bulk operated upon, it is run down again into the fermenting vats situated on the floor beneath. Ten to twelve pints of liquid or 5-1/2 to 6-1/2]** fraction] lbs. of dry brewer's yeast are then added for every 220 lbs. of grain; the vat is securely covered, and the contents are left to ferment. The process is complete at the end of four or five days, and if conducted under favorable conditions there should be a yield of about 6-1/6 gallons of pure alcohol to every 220 lbs. of grain employed. There are a number of different methods of mashing, having each its advantages, and applicable to particular varieties of grain. We will first consider the mashing of the steeped grain in general by one of the older and simpler processes. The grain to be mashed, which has been ground and steeped as before described, is mixed with malt in the proportion of four to one, or even eight to one. In addition, three or four pounds of chaff to every hundred or so pounds of steeped grain should be used. =Mash.= Water is then run into the mash tub in the proportion of about 600 gallons to each 60 bushels of grain. Its temperature should be between 120° and 150° F. During the entrance of water, the mass is well stirred so as to cause the whole of the grain to be thoroughly soaked and to prevent the formation of lumps. It is best to add the grain to the water gradually and to stir thoroughly. To this mass about 400 gallons of boiling water is gradually added to keep the temperature at about 145° F. During the addition of the boiling water the mash should be continually stirred so that the action of the water shall be uniform. This operation should last about two and one half hours. The vat should be then covered and left to stand from three-quarters to one hour for saccharification. Another method of saccharifying is to turn boiling water gradually into the mash tank until the mixture has acquired a temperature of from 140° to 180° F. The mass is thoroughly stirred and the tub is covered and left to subside for from two to four hours, during which time the temperature should not be allowed to fall below 120° F. A small tub needs more heat than a larger tub, and more heat is required in winter than in summer. A convenient method of regulating the temperature of the mash tank, would be by a coil of pipes on the bottom. This would be connected by a two-way cock to a steam boiler and to a source of cold water. Heat should never be carried over 180° F., and the best temperature is from 145° to 165° F. The greatest effect of the diastase of the malt upon the gelatinized starch is at 131° F. For ungelatinized starch this is not great enough, hence the greater part of the mashing is carried on at the lower temperature and only towards the end should the temperature be raised to the maximum 150° F. Every distiller uses his own judgment as to the amount of the mashing water used, its temperature, the length of time during which the mash rests, and the length of time for saccharification. Saccharification may be recognized by the following signs: The mash loses its first white mealy look, and changes to dark brown. It also becomes thin and easily stirred. The taste is sweet and its odor is like that of fresh bread. Corn and other grain may be mashed conveniently in such an apparatus as that described on page 10, as used for potatoes the steam being introduced under pressure. The water is first placed in the steamer. Steam is introduced into the water and it is brought to a boil. The corn is then introduced gradually, the steam pressure increased to its maximum, and the mass blown out as described in Chapter VII. Hellefreund's apparatus (see page 118) may also be used with ground corn. The corn or grain not previously crushed or ground is introduced into a steamer in the proportion of 200 lbs. of corn to 40 gallons of water. The steamer should have about 100 gallons of steam space for this amount. The mashes described above are thick, more or less troublesome to distil, and only simple stills can be used. By the following method a clear saccharine fluid or wort can be obtained. =A mash vat= is used having a double bottom. The upper bottom is perforated and between the two bottoms is a draw-off pipe and a pipe for the inlet of water. Upon the upper perforated bottom is first placed a layer of between two and three pounds of chaff. Upon this is turned in a mixture of 400 lbs. corn and malt in the proportions of 1/5 malt to 4/5 grain. Eighty-seven gallons of water at a temperature of from 85° to 105° F. is then let in to the bottom, while the mixture is thoroughly agitated for 10 minutes. It is then left to subside for half an hour. After this steeping process, the mass is again agitated while 175 gallons of water at 190° F. are let into the tub while the mass is continually and thoroughly stirred by mechanical stirrers. Brewing lasts for half an hour, and the liquid is then left to stand for seven hours. At the end of this period the grain is covered by clear liquid which is drained off through the draw-off cock into the fermenting back. To the contents left in the steeping tank 135 gallons of boiling water are added as before and the liquid therefrom drawn into the fermenting back. It usually requires three infusions to extract the whole of the saccharine and fermentiscible matters contained in the grain. In some places, it is customary to boil down the liquors from the three mashings until they have acquired a specific gravity of about 1.05, the liquor from a fourth mashing being used to bring the whole to the correct degree for fermentation, the liquors from the third and fourth being boiled down to the same density and then added to the rest. In a large Glasgow distillery, the charge for the mash tubs is 29,120 lbs. of grain together with the proper proportion of malt. Two mashings are employed, about 28,300 gallons of water being required; the first mashing has a temperature of 140° F., and the second that of 176° F. In Dublin the proportion of malt employed is only about one-eighth of the entire charge. One mashing is employed, and the temperature of the water is kept at about 143° F. The subsequent mashings are kept for the next day's brewing. By this process the grain is entirely deprived of all fermentible substances which have been carried away in a state of liquid sugar. The whole operation of preparing and saccharifying grain is to-day carried on in steamers, such as described on page 11, and cooking apparatus such as shown in Fig. 1, or in the Henze high pressure steamers and preparatory mash vats described in Chapter II. In steaming grain without pressure, the finely crushed grain is poured slowly into a vat previously nearly filled with water at a temperature of about 140 degrees F. A little less than half a gallon of water is used for each pound of grain. Care must be taken to stir the mass constantly to prevent lumping. When all the corn is mixed in, steam is allowed to enter and the temperature raised to about 200 degrees F. It should be left at this temperature for an hour, or an hour and a half, when the temperature is reduced to 140° F. when about 10 per cent. of crushed malt is added and the temperature reduced to 68° F. by means of suitable cooling devices. When steam cookers are used, the cylindrical boiler is first filled to the proper degree with water at a temperature of 140° F. The meal is then let in gradually being constantly stirred the while. The boiler is then closed and steam gradually let in while the mass is stirred until a pressure of 60 pounds and a temperature of 300° F. has been reached. The starch then becomes entirely gelatinized, the pressure is relieved, and the temperature reduced to 212° F. and then rapidly brought to 145° F. The malt is added mixed with cold water, at such a stage before the saccharifying temperature is reached that the cold malt and water will bring it to 145° F. The malt is stirred and mixed with the mash for five or ten minutes and the mixed mass let into a drop tub when saccharification is completed. It is then cooled as described. When the Henze steamers are used the grain may be treated in either the whole grain or crushed, as the high pressure to which it is subjected and the "blowing out" act to entirely disintegrate it. In this mode of operation, water is first let into the steamer and brought to a boil by the admission of steam. The grain is then slowly let into the apparatus. The water and grain should fill the steamer about two thirds full. The steamer is left open and steam circulated through the grain and water for about an hour, but without any raising of pressure. This acts to thoroughly cook and soften the grain. When sufficiently softened the steam escape cock in the upper part of the steamer (see Fig. 2) is regulated to allow a partial flow of steam through it and a greater flow of steam is admitted through the lower inlet. This keeps the grain in constant ebullition under a pressure of 30 lbs. or so. After another period of an hour the pressure in the steamer is raised to 60 lbs. at which point it is kept for half an hour, when the maximum steam pressure is applied, and the greater portion of the disintegrated mass blown out into a preparatory mass tub, into which malt has been placed mixed with water. The blowing out should be so performed that the temperature in the mass in the tubs shall not exceed 130° F. The mass is stirred and cooled and then the remainder of the mass in the steamer admitted to the tub which should bring the temperature of the mass up to 145° F. It is kept at this temperature for a period varying from half an hour to one and one-half hours and is then cooled to the proper fermenting temperature. Another method of softening corn so that its starch is easily acted upon by the diastase of the malt is to steep it in a sulphurous acid solution at a temperature of about 120° F. for from fifteen to twenty hours. The mass is then diluted to form a semi-liquid pulp and heated to about 190° F. for an hour or two during which the mass is constantly stirred. The malt is then added, the mass is saccharified, cooled and then fermented. Another method is to place mixed grain and hot water in a cooker of the Bohn variety (Fig. 45). After half an hour of stirring and cooking under ordinary pressure, the steam pressure is raised to 45 lbs. This is kept up for from two to three hours when the grain is reduced to a paste. Concentrated muriatic acid equal to 2-1/2 per cent of the weight of grain is then forced in, under steam pressure. In half an hour the grain will be entirely saccharified and ready for fermenting. CHAPTER IX. ALCOHOL FROM BEETS. =Cultivation.= The beetroot (_Beta vulgaris_), indigenous to Europe, is cultivated in France, Germany, Belgium, Holland, Scandinavia, Austria, Russia, and to a very small extent in England and New Zealand, and to a very large extent in the United States and Canada. There are many varieties. The most important to the sugar-maker is the white Silesian, sometimes regarded as a distinct species (_B. alba_); it shows very little above ground, and penetrates about 12 in.; it has a white flesh, the two chief forms being distinguished by one having a rose-colored skin and purple-ribbed leaves, the other a white skin and green leaves. Both are frequently grown together, and exhibit no marked difference in sugar-yielding qualities. Good sugar-beets possess the following broad characteristics: (1) Regular pear-shaped form and smooth skin; long, tapering, carrot-like roots are considered inferior; (2) white and firm flesh, delicate and uniform structure, and clean sugary flavor; thick-skinned roots are spongy and watery; those with large leaves are generally richer; (3) average weight 1-1/2 to 2-1/2 lbs., neither very large nor very small roots being profitable to the sugar-manufacturer; as a rule, beets weighing more than 3-1/2 lbs. are watery, and poor in sugar; and roots weighing less than 3/4 lb. are either unripe or too woody, and in either case yield comparatively little sugar; the sp. gr. of the expressed juice, usually 1.06 to 1.07, even reaching 1.078 in English-grown roots, indicating over 14 per cent. of crystallizable sugar, is the best proof of quality; juice poor in sugar has a density below 1.060; (4) in well-cultivated soil, the roots grow entirely in the ground, and throw up leaves of moderate size. =Composition of the Roots.= Internally the root is built up of small cells, each filled with a juice consisting of a watery solution of many bodies besides sugar. These include several crystallized salts (mostly of which are present in minute traces only), such as the phosphates, oxalates, malates, and chlorides of potassium, sodium, and calcium, the salts of potash being by far the most important; and several colloid bodies (albuminous [nitrogenous] and pectinous compounds); as well as a substance which rapidly blackens on exposure to the air. The greater part of the sugar in ripe beets is crystallizable, and, when perfectly pure, is identical in composition and properties with crystallized cane-sugar; but it is more difficult to refine this sugar so as to free it from the potash salts, and commercial samples have not nearly so great sweetening power as ordinary cane-sugar. Beets contain no uncrystallizable sugar; the molasses produced in beet-sugar manufactories is the result of changes which cannot be entirely avoided in extracting the crystallizable sugar. =Soil.= The best soil for beets contains a fair proportion of organic matter, is neither too stiff nor too light, and crumbles down into a nice friable loam; it must be capable of being cultivated to a depth of at least 16 in. The subsoil should be thoroughly well drained, and rendered friable by autumn-cultivation and free admission of air. A deep friable turnip-loam, containing fair proportions of clay and lime, appears to be the most eligible land for sugar-beets. Lime is a very desirable element. Well-worked clay-soils, especially calcareous clays, are well adapted, if properly drained and of sufficient depth. Peaty soils and moorlands are quite unsuitable, as well as lands which are too dry, like the thin gravelly soils resting on siliceous gravel sub-soils, or too wet and cold, like many of the thin soils above impervious chalk marl. Speaking generally, the best soils for sugar-beet are precisely those on which other root-crops can be grown to perfection, that is, land which is neither too heavy nor too light, which has a good depth, is readily penetrated by the roots, and naturally contains lime, potash, clay, and sand, as well as organic matter, is such proportions as in good friable clay-loams. An analysis of the soil should be made previous to planting it with the sugar-beet, as the salts presented in solution in the soil will pass into the juice, and greatly interfere with the processes of sugar manufacture. Certain soils may be at once indicated as unsuitable; they are clover-land, recent sheep-pastures, forest-land grubbed during the preceding 15 years, the neighborhood of salt works, volcanic and saline soils of all kinds. The beet requires a certain supply of potash and soda salts in the soil, but if these are present in excess, as in recent forest-land, the juice does not work well, nor give its proper yield of sugar. =Manures.= Sugar-beets should be grown with as little farmyard manure as possible; when dung has to be used, as in the case of very poor soils, it should be applied in autumn, or as early as possible during the winter months. The effect of heavy dressings of animal nitrogenous matters or ammoniacal salts, is to produce abundance of leaves, and big watery roots; the latter are comparatively poor in sugar, and contain potash salts derived from the animal matters, which greatly interfere with the extraction of sugar in a crystallized state. Common salt, and saline manures in general, though useful in moderate doses (224 lbs. to 336 lbs. per acre on light soils), should be avoided on the majority of soils, for sugar-beets grown on soils highly manured with common salt produce juice largely impregnated with salt, which is dreaded by the manufacturer even more than albuminous impurities, and nearly as much as excess of potash salts. If the land is in good condition, containing sufficient available nitrogen to meet the requirements of the crop, neither guano nor sulphate of ammonia should be used. They largely increase the weight of the produce per acre; but heavy crops are generally poor in sugar, and furnish a juice that presents much difficulty to the manufacturer. If the land is very poor, and if farmyard manure cannot be obtained and be applied in autumn, 336 to 448 lbs. of Peruvian guano, or 224 lbs. of sulphate of ammonia, mixed with 224 lbs. of superphosphate of lime, per acre, may be sown broadcast in autumn, and 224 lbs. more of superphosphate may be drilled in with the seed in spring. Superphosphate of lime and bones are excellent for sugar-beets, and never injure the quality of the crop, like the indiscriminate use of ammoniacal manures. On light soils, in which potash is often deficient, the judicious use of potash salts has been found serviceable, but only in conjunction with superphosphate and phosphatic guanos. =Sowing.= The best time for sowing beetroot is the beginning or middle of April. If sown too early, the young plants may be partially injured by frost; if later than the first week in May, the crop may require to be taken up in autumn, before it has had time to get ripe. About 10 to 12 lbs. of seed is required per acre. As regards the width between the plants, generally speaking, the distance between the rows and from plant to plant should not be less than 12 nor greater than 18 in. Should the young plants be caught by a night's frost, and suffer ever so little, it is best to plough them up at once and re-sow, for they are certain to run to seed, and are then practically useless for the manufacture of sugar. Sugar-beets require to be frequently horse- and hand-hoed. As long as the young plants are not injured, the application of the hoe from time to time is attended with great benefit to the crop. It is advisable to gather up the soil round each plant, in order that the head may be completely covered with soil. Champonnois' researches point to the advantage of planting in ridges, by which the supply of air to the roots is greatly facilitated. The conditions best calculated to ensure the roots possessing the characters most desirable from a sugar-maker's point of view are chiefly as follows: (1) Not to sow on freshly-manured land; it is eminently preferable not to manure for the beet crop, but to manure heavily for wheat in the preceding year; (2) not to employ forcing manures, nor to apply manure during growth; (3) to use seed from a variety rich in sugar; (4) to sow early, in lines 16 in. apart, at most, the plants being 10 to 11 in. from each other; there will then be 38,000 beets on an acre, weighing 21 to 28 ounces each, or 52,800 to 70,400 lbs. per acre; (5) to weed the fields as soon as the plants are above ground, to thin out as early as possible, and to weed and hoe often, till the soil is covered with the leaves of the plants; (6) never to remove the leaves during growth; (7) finally, not to take up the roots, if it can be avoided, before they are ripe, the period of which will depend upon the season. Good seed may be raised by the following means: The best roots, which show least above ground, are taken up, replanted in good soil, and allowed to run to seed. This seed is already good; but it may be further improved by sowing it in a well-prepared plot possessing all the most favorable conditions; the resulting plants are sorted, set out in autumn, put into a cellar, and in the spring, before transplanting, those of the greatest density, and which will give seeds of the best quality, are separated. These are transplanted at 20 in. between the rows and 13 in. between the feet, which are covered with about 1-1/2 in. of earth. Finally they are watered with water containing molasses and superphosphate of lime, as recommended by Corenwinder. =Harvesting.= Sugar-beets must be taken up before frost sets in. When the leaves begin to turn yellow and flabby, they have arrived at maturity, and the crop should be watched, that it may not get over-ripe. If the autumn is cold and dry, the crop may be safely left in the ground for seven to ten days longer than is needful, but should the autumn be mild and wet, if the roots are left in the soil, they are apt to throw up fresh leaves, and nothing does so much injury. In watching the ripening of the crop, a good plan is to test the sp. gr. of the expressed juice. A root or two may be taken up at intervals, and reduced to pulp on an ordinary hand-grater, the juice obtained by pressing the pulp through calico, and the density observed by a hydrometer. As long as the gravity of the juice continues to increase, the crop should be left in the land. Good sugar-yielding juice has a sp. gr. of about 1.065, rising to about 1.070. Immature roots, cut across, rapidly change color on the exposed surface, turning red, then brown, and finally almost black. If newly-cut slices turn color on exposure, the ripening is not complete; but if they remain some time unaltered, or turn only slightly reddish, they are sufficiently ripe to be taken up. The crop should be harvested in fine, dry weather. In order that the roots may part with as much moisture as possible, they are left exposed to the air on the ground before being stacked, but not for longer than a few days, and they need to be guarded against direct sunlight. Perhaps the best plan is to cover them loosely with their tops in the field for a couple of days, then trim them, and at once stack them. =Storing.= For storing roots, especial care should be taken to prevent their germinating and throwing out fresh tops, which is best done by selecting a dry place for the storage ground. They may be piled in pyramidal stacks, about six feet broad at base, and seven feet high. At first, the stacks should be thinly covered with earth, that the moisture may readily evaporate; subsequently, when frosty weather sets in, another layer of earth, not exceeding one foot in thickness, may be added. This is essentially the method generally adopted for storing potatoes and beets. [Illustration: FIG. 46.--Stack for Storing Beets.] In continental Europe and Canada, extra precaution is necessitated by the rigorous climate. In S. Russia, the plan shown in Fig. 46 is sometimes used. The beets are disposed completely below the surface of the soil, in a trench dug with sharply sloping sides. At about 15 in. from the bottom, is an openwork floor of reeds, on which the beets are piled to within a few inches of the level of the exterior soil. On the top, and following the apex of the heap, is laid a triangular ridge-piece _a_, for the purpose of facilitating evaporation. The whole is covered with a layer _b_ of straw and fine earth, the thickness of which is varied according to the indications of the thermometer _c_ placed in the center of the mass. Between the floor of the trench and the openwork floor is a space _d_, communicating with two vertical channels leading to the outer air, thus providing ventilation. The outlets of the channels can be opened and closed at will. The Russians also often employ regular cellars, as shown in Fig. 47. The structure consists of two stories, covered with a bed of earth, each furnished with a floor of hurdles or open planking, on which the beets are piled to the depth of about one yard. Lateral passages facilitate ventilation, and openings in the roof permit the heated air to escape. The cost of erecting these cellars is heavy, but there is great saving of labor in storing the beets, as it suffices to simply pile them up on the floors. Moreover, the arrangement permits the examination of the contents beyond the indications of a thermometer; and enables any portion to be removed, even during snowy weather. [Illustration: FIG. 47.--Storage Cellar for Beets.] =Alcohol from Beets.= Beets contain 85 per cent. of water, and about 10 per cent. of cane sugar, the remainder being woody fibre and albumen; cane sugar not being in itself fermentible,--as is grape sugar,--it has to be converted into "inverted sugar" by a ferment as yeast. Either the sugar beets may be mashed or the molasses which remains from the manufacture of beet sugar (as described in Chapter X). The conversion of the sugar into alcohol is effected in several different ways, of which the following are the principal: By rasping the roots and submitting them to pressure, and fermenting the expressed juice. By maceration with water and heat. By direct distillation of the roots. The first two methods are the best as by them the woody fibre of the plant which is non-fermentible is separated from the fermentible juice. In both the first and second processes the beets must first be entirely cleaned of adhering dirt, trash and clods of earth, and then rasped, pulped or sliced by certain machinery. =Cleaning.= Care must be taken in this operation that the beets shall be freed from small stones and adhering hard lumps of earth which would otherwise get into the rasping machinery to the damage and stoppage of the mechanism. There are many forms of cleaners but all are alike in this,--that the beets shall be subjected to the action of water while traveling through or over a perforated casing. The simplest machine, and one easily constructed by any carpenter, comprises an elongated cylinder formed of lathes or strips spaced apart such distance as will allow dirt and stones to pass between them. This is mounted on a central shaft and revolves in a tank of water. It should be slightly inclined so that the potatoes or beets to be washed may feed downward from the open upper end-disk or wheel, to the lower end where they are thrown out. At the upper end is a hopper and at the lower, the end disk has inwardly projecting lips, which as the cylinder revolves lifts the beets up and tumbles them out on to an incline which carries them to the rasping machine. Another form of machine comprises a perforated cylinder of sheet iron, revolving in a tank of water. A better form of cleaner than either of those consists of an inclined trough in which a spiral feeding screw of sheet iron rotates. The beets are fed into the trough at its lower end and are carried upward, slowly, by the feeding screw. Above the trough is a water pipe having a number of outlets by which water may fall on to the beets and into the trough. The water rushing down the inclined trough carries with it all dirt and stones, and by the time the beets have reached the upper end they are entirely cleaned and ready for slicing or rasping. For pressing out the juice, the beets are mashed into a pulp, while for diffusion the beets are sliced. =Rasping.= Fig. 48 shows one form of rasping machine. On a suitable supporting frame is mounted a cylinder _a_ having a diameter of about 24 inches. The cylinder is formed of alternate saw blades and wooden washers holding them a slight distance apart. The saws or teeth are so set on the cylinder as not to slice the beets but to shred them up into a fine pulp. The cylinder rotates at a speed of 800 to 1000 revolutions a minute in front of an inclined table, having a jigger whereby the beets are fed downward against the toothed cylinder. The teeth carry the pulp downward and it falls into a receptacle beneath. [Illustration: FIG. 48.--Beet and Potato Rasp.] It is best to add to this pulp a small portion of sulphuric acid, say two-tenths of one per cent. This prevents by-fermentations. =Pressing.= The pulp obtained from the raspers has now to be expressed. This is either done by platen presses or by roller presses. With platen presses the first pressing may be done by screws, but the final pressing should be accomplished by hydraulic presses. For the hydraulic press, the pulp is placed in woolen sacks, containing 10 to 12 lbs., superposed in the press with their mouths doubled under, and separated by iron plates; about 25 are collected, and the pile is put into a screw-press, called a "preparatory" press, which extracts about 45 to 50 per cent. of the juice. These pressed sacks are piled anew on the movable plate of a powerful hydraulic press, which takes 50 at a charge. Each preparatory press can supply four hydraulic presses, which are ranged around it, so that of the four presses, there will be one charging, one commencing to press, one in full pressure, and one discharging, at the same moment. Motion is communicated to the four hydraulic presses by four pumps mounted on the same bed, and tended by the same workman who directs the pressing. An improvement upon the general form of hydraulic press is that devised by Lalouette, which enables two workmen and one boy to work five presses. These presses turn out about 34,200 lbs. per 24 hours in the first pressing, and 68,400 lbs. in the second. Hydraulic presses are rapidly falling into disuse in the beet-sugar industry, by reason of the superior merits of continuous presses, and the extended adoption of the diffusion system. Continuous presses for beet were suggested by the roller-mills used in the cane-sugar industry. But the conditions in the two cases are widely different; the begass of the cane is solid, and readily parts from the juice; whereas the pulp and juice of the beet have a strong tendency to combine, and the roller-surface must therefore be permeable only by the juice. In Poizot et Druelle's press, the pulp passes between two cylinders, carried by endless cloths. The object is to unite the best features of the hydraulic press. To this end, a first gentle pressing is produced against the first cylinder by the elasticity of the principal cloth on which it is borne. Then, encountering a series of four little rollers, performing the functions of the preparatory press, it is next seized between the second and first cylinders, and deprived of the maximum quantity of juice. [Illustration: FIG. 49.--Dujardin's Roll Press.] Dujardin's roll press is shown in Fig. 49, which is a vertical section of the machine, the side plate being removed. The pulp is forced upward through a pipe _C_ under high pressure. This has a regulating slide valve _D_. The rolls _B B_ revolve towards and nearly in contact with each other, and they are perforated so that the expressed juice may run off through the rolls. These perforations are conical in form with the apex of the cone outward. The cylinders are also covered with a webbing of cloth or horse hair. Below the rolls is block _C´_, which with the outer walls of the chamber, form diverging passages which extend upward, as shown, on either side of the rolls and then downward along the lower faces of the rolls to the point when they contact. The pulp is compressed with great force against and between the rolls, the juice is forced through the perforations and the residue passes upward and outward under the presser bar _E_ in the form of a ribbon which is guided away by the trough _F_. The pressure of the bar _E_ is regulated by screws and the tighter said bar is pressed against the rolls the greater will be the pressure of the pulp behind the bar and against the rolls, and the greater the juice expressed. The rolls revolve very slowly only about seven or eight times a minute but the capacity of the machine is very great, it being capable of pressing the pulp of from 85,000 to 175,000 lbs. of beets daily. The residue from the first pressing should be submitted to a further pressing after being macerated with spent wash. This residue may be fed to cattle. The utmost cleanliness is essential to these processes; all the utensils employed should be washed daily with lime-water to counteract acidity. =Extraction by Maceration and Diffusion.= The object of this process is to extract from the beets by means of water or spent liquor all the sugar which they contain, without the aid of rasping or pressure. Spirit is thus produced at considerably less expense, although it is not of so high a quality as that yielded by the former process. The operation consists in slicing up the beets in a specially constructed slicing machine, into slices of regular thickness, and then allowing the slices to macerate in a series of vats at stated temperatures. It is essential that the knives by which the roots are cut should be so arranged that the roots are divided into slices having a width of 4/10 of an inch and a thickness of 4/100 of an inch, and a variable length; the roots are, of course, well washed before being placed in the hopper of the cutter. When cut, the beets are covered with boiling water in a macerator of wood or iron for one hour, the water should contain 4.4 of sulphuric acid to every 2200 lbs. of beets. After this, the water is drawn off into a second vat in which are placed more beets, and allowed to macerate again for an hour. This is repeated a third time in another vat, and the juice, which has now acquired a density equal to that obtained by rasping, is run off into the fermenting vat. When the first vat is empty it is immediately refilled with boiling water and fresh beets; the juice from this operation is run into the second vat, when the contents of that one are run into the third. To continue the operation, the beets are completely exhausted by being macerated for an hour with a third charge of boiling water (acidulated as in the former case). The exhausted pulp is removed to make room for fresh slices; and the first vat is then charged with juice which has already passed through the second and third vats. After macerating the fresh beets for one hour, the charge is ready for fermentation. In ordinary weather, the juice should now be at the right heat for this process, viz., about 71.1° or 75.2° F., but in very cold weather it may require some re-heating. In Fig. 50 is shown a series of vats for the extraction of the sugar from beets such as is termed a "diffusion battery." [Illustration: FIG. 50.--Diffusion Battery.] The vessels, 1, 2, 3 and 4 are of wood or sheet iron. Each vessel has a bottom sieve and a top sieve between which the beet slices are to be placed. From the bottom of each vessel below the sieve a pipe _D_ runs to the top of the vessel next in order. From the bottom of the last vessel 4 of the series a pipe _C_ runs back to the top of the one first used. Pipes _A_ and _B_ are connected to each vessel for the admission of water and spent wash respectively. A discharge pipe _E_ leads from each vessel to a collecting vat 5. Maceration and diffusion is accomplished as follows: The sliced beets are placed between the sieves in vessel 1 and water or spent wash at a temperature of 185° F. is let in and the beets allowed to macerate for three-quarters of an hour, meanwhile tub 2 is charged with sliced beets. The cock or pipe _D_ between the vessels is opened when the time, three quarters of an hour, has elapsed; hot water or spent wash is admitted by pipes _A_ or _B_ to the vessel 1, which forces the sugar solution therein into vessel 2. When the required amount of fluid has been passed into 2 from 1, the inlet of water into 1 is stopped, and the vessel heated to 185° F. Vessel 3 is charged with beet slices and in three-quarters of an hour vessels 1, 2 and 3 are connected and water or wash admitted into 1, which forces the solution in 1 into 2 and that in 2 into 3 when it is again raised to 185° F. The same operation is repeated as to vessel 4 and in three-quarters of an hour all the vessels are connected, hot water or spent wash is admitted to 1 and the sugar solution drawn off from 4 into the vat. The beets in tub 1 having now been exhausted, the fluid in that vessel is drawn off and the exhausted beets thrown away. 1 is now recharged with beets and the pipe between it and 4 opened. The former operation is repeated except that now vessel 4 becomes 1, and 1 becomes 4. These successive chargings and dischargings are continued; vessel 3 becomes 1 in its turn and so on. =Fermentation.= Before fermentation the juice procured as has been described is brought to about 82° F.; at this temperature it is run off into the fermenting vats. Here it is necessary, as before noted, to add to the juice a small quantity of concentrated sulphuric acid, for the purpose of neutralizing the alkaline salts which it contains, and of rendering it slightly acid in order to hasten the process; this quantity must not exceed 5-1/2 lbs. to every 1220 gallons of juice, or the establishment of fermentation would be hindered instead of promoted. The addition of this acid tends also to prevent the viscous fermentation to which the juice obtained by rasping and pressure is so liable. Although the beet contains albumen, which is in itself a ferment, it is necessary, in order to develop the process, to have recourse to artificial means. A small quantity of brewer's yeast--about 1-3/4 oz. per 22 gallons of juice--is sufficient for this; the yeast must previously be mixed with a little water. An external temperature of about 68° to 78° F. must be carefully maintained. Fermentation lasts for from four to five hours. The fermentation of acidulated beet-juice sets in speedily. The chief obstacle to the process is the mass of thick scum which forms upon the surface of the liquor. This difficulty is sometimes obviated by using several vats and mixing the juice, while in full fermentation, with a fresh quantity. Thus, when three vats are employed, one is set to ferment; at the end of four or six hours, half its contents are run into the second vat and here mixed with fresh juice. The process is arrested, but soon starts again in both vats simultaneously; the first is now allowed to ferment completely, which is effected with much less difficulty than would have been the case had the vat not been divided. Meanwhile the second vat, as soon as the action is at its height, is divided in the same manner, one-half its contents being run into the third. When this method is employed, it is necessary to add a little yeast from time to time when the action becomes sluggish. =Direct Distillation of the Roots.= This process, commonly called "Leplay's method," consists in fermenting the sugar in the slices themselves. The operation is conducted in huge vats, holding as large a quantity of matter as possible, in order that the fermentation may be established more easily. They usually contain about 750 gallons, and a single charge consists of 2200 lbs. of the sliced roots. The slices are placed in porous bags in the vats, containing already about 440 gallons of water acidulated with a little sulphuric acid; and they are kept submerged by means of a perforated cover, which permits the passage of the liquor and of the carbonic acid evolved; the temperature of the mixture should be maintained at about 77° or 80° F. A little yeast is added, and fermentation speedily sets in; it is complete in about 24 hours or more, when the bags are taken out and replaced by fresh ones; fermentation declares itself again almost immediately, and without any addition of yeast. New bags may, indeed, be placed in the same liquor for three or four successive fermentations without adding further yeast or juice. The slices of beets charged with alcohol are now placed in a distilling apparatus of a very simple nature. It consists of a cylindrical column of wood or iron, fitted with a tight cover, which is connected with a coil or worm, kept cool in a vessel of cold water. Inside this column are arranged a row of perforated diaphragms or partitions. The space between the lowest one and the bottom of the cylinder is kept empty to receive the condensed water formed by the steam, which is blown into the bottom of the cylinder in order to heat the contents. Vapors of alcohol are thus disengaged from the undermost slices, and these vapors as they rise through the cylinder vaporize the remaining alcohol, and finally pass out of the top at a considerable strength and are condensed in the worm. When all the contents of the still have been completely exhausted of spirit, the remainder consists of a cooked pulp, which contains all the nutritive constituents of the beet except the sugar. CHAPTER X. ALCOHOL FROM MOLASSES AND SUGAR CANE. Another common source of alcohol is molasses. Molasses is the uncrystallizable syrup which constitutes the residiuum of the manufacture and refining of cane and beet sugar. It is a dense, viscous liquid, varying in color from light yellow to almost black, according to the source from which it is obtained; it tests usually about 40° by Baume's hydrometer. The molasses employed as a source of alcohol must be carefully chosen; the lightest in color is the best, containing most uncrystallized sugar. The manufacture is extensively carried on in France, where the molasses from the beet sugar refineries is chiefly used on account of its low price, that obtained from the cane sugar factories being considerably dearer. The latter is, however, much to be preferred to the former variety as it contains more sugar. Molasses from the beet sugar refineries yields a larger quantity and better quality of spirit than that which comes from the factories. Molasses contains about 50 per cent. of saccharine matter, 24 per cent. of other organic matter, and about 10 per cent. of inorganic salts, chiefly of potash. It is thus a substance rich in matters favorable to fermentation. When the density of molasses has been lowered by dilution with water, fermentation sets in rapidly, more especially if it has been previously rendered acid. As, however, molasses from beet generally exhibits an alkaline reaction, it is found necessary to acidify it after dilution; for this purpose sulphuric acid is employed, in the proportion of about 4-1/2 lbs. of the concentrated acid to 22 gallons of molasses, previously diluted with eight or ten volumes of water. Three processes are thus employed in obtaining alcohol from molasses; dilution, acidification, and fermentation. The latter is hastened by the addition of a natural ferment, such as brewer's yeast. It begins in about eight or ten hours, and lasts upwards of 60. About three gallons of Alcohol may be obtained from one hundred pounds of molasses. =Beet Sugar Molasses.= The first step in the process of rendering the molasses fermentable is to mix the molasses with water, to a certain dilution, in the proportion of two parts of water to one of molasses. This may be done by hand, but preferably it is performed in a vat provided with stirring or agitating mechanism, such as will effectually mix the water with the viscid syrup, and whereby also the wash may be thoroughly agitated and aerated. There are numerous forms of mixing vats, all working however, on the principle shown in Fig. 51. In this, the vat _A_ is provided with a central shaft _C_ carrying radial mixing blades _E_. This shaft is driven by bevel gears _D_, _F_. As the rotation of these blades would merely tend to create a rotary current of molasses and water, and not to mix them, some means should be used for impeding and breaking up this current. To that end the cover is provided with downwardly projecting rods _I_ which create counter currents, and thoroughly intermingle the two liquids. Another and even better form of mixer consists of a tank into the lower portion of which enters a perforated pipe of relatively large diameter. This is provided at the end with an air entrance and a steam injector. The injected steam draws in air and the steam and air are forced under pressure into the vat, thus diluting the contained molasses, agitating it and thoroughly aerating it. [Illustration: FIG. 51.--Mixing Vat.] The molasses as it comes from the sugar house may contain anywhere from 30 to 45 per cent of sugar, and this should be diluted with water to a concentration of 16 to 18 per cent of sugar. The density of the wash after "setting up" is 1.060. It is to be noted that though with improved apparatus a wash as concentrated at 12° or 15° Baume may be worked; yet where simple apparatus is used six degrees or eight degrees is better and much more favorable to rapid and complete fermentation. After setting up, one gallon of strong sulphuric acid and 10 lbs. of sulphate of ammonia are added for each 1000 gallons of wash. This neutralizes the alkaline carbonates in the beet juice which would otherwise retard fermentation, and it assists the yeast to invert the cane sugar as formerly described. The addition of ammonia is in order to give food to the yeast and obtain a vigorous fermentation. The yeast used for fermenting molasses is prepared either from malt or grain and is used as concentrated as possible, and in the proportion of about 2 per cent. The "pitching" temperature of a molasses wash varies with the concentration of the wash, being higher for strongly concentrated solutions than for weak ones. When the wash tests as high as 12° Baume, fermentation begins at about 77° F. and is raised during fermentation to 85° or 90° F. A temperature around 82° F. is best on the average as this is most conducive to the growth of yeast. Where the vats are large and the syrup considerably diluted the temperature rises very quickly and must be moderated by passing a current of cold water through a coil of pipe on the bottom of the vat. In the making of molasses mashes it must be remembered that every gallon of molasses will be diluted with about five gallons of water or other fermented liquid matter, and therefore 50 gallons of molasses wash will require a still capable of working up about 300 gallons. It is possible to distill four or five charges during the day of 12 hours and hence a still of 60 gallons will be capable of distilling the beer or wash made with 50 gallons of molasses. A still with a capacity of 100 gallons operating on wash having a strength of one gallon of molasses to five of water, will produce about 10 gallons of proof spirit from each charge; thus a 100 gallon still will make from 40 to 80 gallons of spirit in a day. With unskilled labor, however, it is impossible to get this rate of production and the best that can be done will be about four charges a day. It may be suggested that in getting estimates on stills it is best to accompany the request with a statement of the character of the mash intended to be treated, the amount of raw materials intended to be used up, the charging capacity required, number of gallons of mash desired to be worked up every 12 hours. =Fermenting Raw Sugar.= This is accomplished by dissolving the sugar in hot water, then diluting it, and then adding a ferment,--fermentation being aided by adding sulphuric acid to the diluted molasses, in the proportion of one-half to one pound of acid to every hundred pounds of pure sugar used. The wash is pitched with compressed yeast in the proportion of 2-1/2[** fraction] to 8 per cent of the weight of the sugar used. The pitching temperature is from 77° to 79° F., and the period of fermentation is 48 hours. =Cane Sugar Molasses.= Besides the molasses of the French beet sugar refineries, large quantities result from the manufacture of cane sugar in Jamaica and the West Indies. This is entirely employed for the distillation of _rum_. As the pure spirit of Jamaica is never made from sugar, but always from molasses and skimmings, it is advisable to notice these two products, and, together with them, the exhausted wash commonly called _dunder_. The molasses proceeding from the West Indian cane sugar contains crystallizable and uncrystallizable sugar, gluten, or albumen, and other organic matters which have escaped separation during the process of defecation and evaporation, together with saline matters and water. It therefore contains in itself all the elements necessary for fermentation, _i.e._, sugar, water, and gluten, which latter substance, acting the part of a ferment, speedily establishes the process under certain conditions. _Skimmings_ comprise the matters separated from the cane juice during the processes of defecation and evaporation. The scum of the clarifiers, precipitators, and evaporators, and the precipitates in both clarifiers and precipitators, together with a proportion of cane sugar mixed with the various scums and precipitates, and the "sweet-liquor" resulting from the washing of the boiling-pans, etc., all become mixed together in the skimming-receiver and are fermented under the name of "skimmings." They also contain the elements necessary for fermentation, and accordingly they very rapidly pass into a state of fermentation when left to themselves; but, in consequence of the glutinous matters being in excess of the sugar, this latter is speedily decomposed, and the second, or acetous fermentation, commences very frequently before the first is far advanced. _Dunder_ is the fermented wash after it has undergone distillation, by which it has been deprived of the alcohol it contained. To be good, it should be light, clear, and slightly bitter; it should be quite free from acidity, and is always best when fresh. As it is discharged from the still, it runs into receivers placed on a lower level, from which it is pumped up when cool into the upper receivers, where it clarifies, and is then drawn down into the fermenting cisterns as required. Well-clarified dunder will keep for six weeks without any injury. Good dunder may be considered to be the liquor, or "wash," as it is termed, deprived by distillation of its alcohol, and much concentrated by the boiling it has been subjected to; whereby the substances it contains, as gluten, gum, oils, etc., have become, from repeated boilings, so concentrated as to render the liquid mass a highly aromatic compound. In this state it contains at least two of the elements necessary for fermentation, so that, on the addition of the third, viz., sugar, that process speedily commences. The first operation is to clarify the mixture of molasses and skimmings previous to fermenting it. This is performed in a leaden receiver holding about 300 or 400 gallons. When the clarification is complete, the clear liquor is run into the fermenting vat, and there mixed with 100 or 200 gallons of water (hot, if possible), and well stirred. The mixture is then left to ferment. The great object that the distiller has in view in conducting the fermentation is to obtain the largest possible amount of spirit that the sugar employed will yield, and to take care that the loss by evaporation or acetification is reduced to a minimum. In order to ensure this, the following course should be adopted. The room in which the process is carried on must be kept as cool as it is possible in a tropical climate; say, 75° to 80° F. Supposing that the fermenting vat has a capacity of 1000 gallons, the proportions of the different liquors run in would be 200 gallons of well-clarified skimmings, 50 gallons of molasses, and 100 gallons of clear dunder; they should be well mixed together. Fermentation speedily sets in, and 50 more gallons of molasses are then to be added, together with 200 gallons of water. When fermentation is thoroughly established, a further 400 gallons of dunder may be run in, and the whole well stirred up. Any scum thrown up during the process is immediately skimmed off. The temperature of the mass rises gradually until about 4° or 5° above that of the room itself. Should it rise too high, the next vat must be set up with more dunder and less water; if it keeps very low, and the action is sluggish, less must be used next time. No fermenting principle besides the gluten contained in the wash is required. The process usually occupies eight or ten days, but it may last much longer. The liquid now becomes clear, and should be immediately subjected to distillation to prevent acetous fermentation. Sugar planters are accustomed to expect one gallon of proof rum for every gallon of molasses employed. On the supposition that ordinary molasses contains 65 parts of sugar, 32 parts of water, and three parts of organic matter and salts, and that, by careful fermentation and distillation, 33 parts of absolute alcohol may be obtained, we may then reckon upon 33 lbs. of spirit, or about four gallons, which is a yield of about 5-2/3[** fraction] gallons of rum, 30 per cent. over-proof, from 100 lbs. of such molasses. The following process is described in Deerr's work on "Sugar and Sugar Cane." "In Mauritius a more complicated process is used; a barrel of about 50 gallons capacity is partly filled with molasses and water of density 1.10 and allowed to spontaneously ferment; sometimes a handful of oats or rice is placed in this preliminary fermentation. When attenuation is nearly complete more molasses is added until the contents of the cask are again of density 1.10 and again allowed to ferment. This process is repeated a third time; the contents of the barrel are then distributed between three or four tanks holding each about 500 gallons of wash of density 1.10 and 12 hours after fermentation has started here, one of these is used to pitch a tank of about 8,000 gallons capacity; a few gallons are left in the pitching tanks which are again filled up with wash of density 1.10 and the process repeated until the attenuations fall off, when a fresh start is made. This process is very similar to what obtains in modern distilleries save that the initial fermentation is adventitious. "In Java and the East generally, a very different procedure is followed. In the first place a material known as Java, or Chinese, yeast is prepared from native formulæ; in Java, pieces of sugar cane are crushed along with certain aromatic herbs, amongst which galanga and garlic are always present, and the resulting extract made into a paste with rice meal; the paste is formed into strips, allowed to dry in the sun and then macerated with water and lemon juice; the pulpy mass obtained after standing for three days is separated from the water and made into small balls, rolled in rice straw and allowed to dry; these balls are known as Raggi or Java yeast. In the next step rice is boiled and spread out in a layer on plantain leaves and sprinkled over with Raggi, then packed in earthenware pots and left to stand for two days, at the end of which period the rice is converted into a semi-liquid mass; this material is termed Tapej and is used to excite fermentation in molasses wash. The wash is set up at a density of 25° Balling and afterwards the process is as usual. In this proceeding the starch in the rice is converted by means of certain micro-organisms _Chlamydomucor oryzae_ into sugar and then forms a suitable habitat for the reproduction of yeasts which are probably present in the Raggi but may find their way into the Tapej from other sources. About 100 lbs. of rice are used to pitch 1,000 gallons of wash." CHAPTER XI. ALCOHOLOMETRY. Alcoholmetry is the name given to a variety of methods of determining the quantity of absolute alcohol contained in spirituous liquors. It will readily be seen that a quick and accurate method of making such determinations is of the very utmost importance to those who are engaged in the liquor traffic, since the value of spirit depends entirely upon the percentage of alcohol which it contains. When alcoholic liquors consist of simple mixtures of alcohol and water, the test is a simple one, the exact percentage being readily deducible from the specific gravity of the liquor, because to a definite specific gravity belongs a definite content of alcohol; this is obtained either by means of the _specific gravity bottle_, or of hydrometers of various kinds, specially constructed. All hydrometers comprise essentially a graduated stem of uniform diameter, a bulb forming a float and a counterpoise or ballast. The hydrometers may either be provided with a scale indicated on the neck or else with weights added to sink the hydrometer to a certain mark. The first instruments are called hydrometers of "constant immersion," the others, of "variable immersion." At the latter end of the last century, a series of arduous experiments were conducted by Sir C. Blagden, at the instance of the British government, with a view to establishing a fixed proportion between the specific gravity of spirituous liquors and the quantity of absolute alcohol contained in them. The result of these experiments, after being carefully verified, led to the construction of a series of tables, reference to which gives at once the percentage of alcohol for any given number of degrees registered by the hydrometer; these tables are invariably sold with the instrument. They are also constructed to show the number of degrees over-or under-proof, corresponding to the hydrometric degrees. Other tables are obtainable which give the specific gravity corresponding to these numbers. The measurement of the percentage of absolute alcohol in spirituous liquors is almost invariably expressed in volume rather than weight, owing to the fact that such liquors are always sold by volume. Nevertheless, the tables referred to above show the percentage of spirit both by volume and weight. [Illustration: FIG. 52.--Syke's Hydrometer.] In the United States the standard liquor, known as _proof spirit_, contains 92.3 per cent. by weight and 94.9 per cent. by volume, of absolute alcohol; it has a specific gravity of .9186 at 60° F. A proof gallon contains by measurement 100 parts of alcohol and 81.5 parts of water. The strength and therefore the value of spirituous liquors is estimated according to the quantity by volume of anhydrous spirit contained in the liquor with reference to this standard. Thus the expression "20 _per cent. overproof_," "20 _per cent. underproof_," means that the liquor contain 20 volumes of water for every 100 volumes over or under this fixed quantity, and that in order to reduce the spirit to _proof_, 20 per cent. of water by volume, must be subtracted or added, as the case may be. Any hydrometer constructed for the measurement of liquids of less density than water may be employed. That known as "Syke's" is most commonly used for alcoholometric purposes. It is shown in Fig. 52 and consists of a spherical brass ball _A_, to which is fixed two stems; the upper one _B_ is also of brass, flat, and about 3-1/2[** fraction] in. in length; it is divided into ten parts, each being subdivided into five, and the whole being numbered as shown in the figure. The lower stem _C_ is conical, and slightly more than an inch long; it terminates in a weighted bulb _D_. A series of circular weights, of the form shown in the figure, accompany the instrument; these are slipped upon the top of the lower stem _C_, and allowed to slip down until they rest upon the bulb _D_. The instrument is used in the following way: It is submerged in the liquor to be tested until the whole of the upper stem is under the surface, and an idea is thus gained of the weight that will be required to _partly_ submerge the stem. This weight is added, and the hydrometer again placed in the liquor. The figure on the scale to which the instrument has sunk when at rest is now observed, and added to the number on the weight used, the sum giving, by reference to the tables, the percentage by volume of absolute alcohol above or below the standard quantity. In exact estimations, the temperature of the liquor tested must be carefully registered, and the necessary corrections made. In Jones's hydrometer, which is an improvement upon Syke's, a small spirit thermometer is attached to the bulb, and by noting the temperature of the liquor at the time of the experiment, and referring to the tables accompanying the instrument, the strength is found at once without the need of calculation. Dica's hydrometer is very similar to Jones's instrument above described. It is of copper, has a stem fitted to receive brass poises, a thermometer, a graduated scale, etc. In Europe, Gay-Lussac's hydrometer and tables are chiefly used for alcoholometric testing. This instrument is precisely similar in construction to those of Twaddle and Baume. On the scale, zero is obtained by placing it in pure distilled water at 59° F., and the highest mark, or 100, by placing it in pure alcohol at the same temperature, the intermediate space being divided into 100 equal divisions, each representing one per cent. of absolute alcohol. The correction for temperature, as in the above cases, is included in the reference tables. Another hydrometer, used in France for alcoholometric determinations, is Cartier's. In form it is precisely similar to Baume's hydrometer. Zero is the same in both instruments, but the point marked 30° in Cartier's is marked 32° in Baume's, the degrees of the latter being thus diminished in the proportion of 15 or 16. Cartier's hydrometer is only used for liquids lighter than water. The alcoholmeter of Tralles is the official instrument for testing alcoholic liquors in the U. S. but the instrument which is most generally used both here and abroad is that of Beaumé. There are two instruments bearing Beaumé's name, one for liquids lighter than water, the other for those which are heavier. All hydrometers, alcoholmeters and saccharometers work on the same principle, though they are each differently graduated for the particular work to be done and the details of the measuring process are slightly different. All these instruments are provided with tables whereby their readings may be corrected and the specific gravity of the liquid determined. The above hydrometric methods can be safely employed only when the spirit tested contains a very small amount of solid matter, since, when such matter is contained in the liquor in quantity, the density alone cannot possibly afford a correct indication of its richness in alcohol. Many methods have been proposed for the estimation of alcohol in liquor, containing saccharine coloring and extractive matters, either in solution or suspension. Undoubtedly the most accurate of these, though at the same time the most tedious, is to subject the liquor to a process of distillation by which a mixture of pure alcohol and water is obtained as the distillate. This mixture is carefully tested with the hydrometer, and the percentage of alcohol in it determined by reference to the tables as above described; from this quantity and the volume of the original liquor employed the percentage by volume of alcohol in that liquor is readily found. The condensing arrangement must be kept perfectly cool, if possible in a refrigerator, as the alcohol in the distillate is very liable to be lost by re-evaporation. When great accuracy is desired, and time is at the operator's disposal, the above method is preferable to all others. It is performed in the following manner: Three hundred parts of the liquor to be examined are placed in a small still, or retort, and exactly one-third of this quantity is distilled over. A graduated glass tube is used as the receiver, in order that the correct volume may be drawn over without error. The alcoholic richness of the distillate is then determined by any of the above methods, and the result is divided by three, which gives at once the percentage of alcohol in the original liquor. The strength at proof may be calculated from this in the ordinary way. If the liquor be acid, it must be neutralized with carbonate of soda before being submitted to distillation. From eight to ten per cent. of common salt must be added, in order to raise the boiling point, so that the whole of the spirit may pass over before it has reached the required measure. In the case of the stronger wines it is advisable to distil over 150 parts and divide by two instead of three. If the liquor be stronger than 25 per cent. by volume of alcohol, or above 52 to 54 per cent. under-proof, an equal volume of water should be added to the liquid in the still, and a quantity distilled over equal to that of the sample tested, when the alcoholic strength of the distillate gives, without calculation, the correct strength required. If the liquor be stronger than 48 to 50 per cent. under-proof, three times its volume of water must be added, and the process must be continued until the volume of the distillate is twice that of the sample originally taken. In each case the proportionate quantity of common salt must be added. For the estimation of alcohol in wines, liquors, etc., the following method may be employed: A measuring flask is filled up to a mark on its neck with the liquor under examination, which is then transferred to a retort; the flask must be carefully rinsed out with distilled water, and the rinsings added to the liquor in the retort. About two-thirds are then drawn over into the same measuring flask, and made up to its previous bulk with distilled water, at the same temperature as that of the sample before distillation. The strength is then determined by means of Syke's hydrometer, and this, if under-proof, deducted from 100, gives the true percentage of proof-spirit in the wine. [Illustration: FIG. 53.--Field's Alcoholometer.] A quick, if not always very exact, method consists in determining the point at which the liquor boils. The boiling point of absolute alcohol being once determined, it is obvious that the more it is diluted with water the nearer will the boiling point of the mixture approach that of water; moreover, it has been proved that the presence of saccharine and other solid matters has but an almost inappreciable effect upon this point. Field's alcoholometer, since improved by Ure, is based upon this principle. It is shown in Fig. 53, and consists, roughly speaking, of a cylindrical vessel _A_, to contain the spirit; this vessel is heated from beneath by a spirit lamp, which fits into the case _B_. A delicate thermometer _C_, the bulb of which is introduced into the spirit, is attached to a scale divided into 100 divisions, of which each represents one degree over-or under-proof. This method is liable to several small sources of error, but when a great many determinations have to be made, and speed is an object rather than extreme accuracy, this instrument becomes exceedingly useful. It does not answer well with spirits _above_ proof, because the variation in their boiling points are so slight as not to be easily observed with accuracy. But for liquors under-proof, and especially for wines, beer, and other fermented liquors, it gives results closely approximating to those obtained by distillation, and quite accurate enough for all ordinary purposes. Strong liquors should therefore be tested with twice their bulk, and commercial spirits with an equal bulk, of water, the result obtained being multiplied by two or three, as the case may be. Another very expeditious, but somewhat rough, method was invented by Geisler. It consists in measuring the tension of the vapor of the spirit, by causing it to raise a column of mercury in a closed tube. The very simple apparatus is shown in Fig. 54. _A_ is a small glass bulb, fitted with a narrow tube and stop-cock. This vessel is completely filled with the spirit, and is then screwed upon a long, narrow tube _B_, bent at one end and containing mercury. This tube is attached to a graduated scale showing the percentage of absolute alcohol above or below proof. To make the test the cock is opened, and the bulb, together with the lower part of the tube, is immersed in boiling water, which gradually raises the spirit to its boiling-point. When this is reached, the vapor forces the mercury up the tube, and, when stationary, the degree on the scale to which it has ascended gives directly the percentage of alcohol. [Illustration: FIG. 54.--Geisler's Apparatus.] Another method, which is not to be relied on for very weak liquors, but which answers well for cordials, wines, and strong ales, is that known as Brande's method. The liquor is poured into a long, narrow glass tube, graduated centesimally, until it is half-filled. About 12 or 15 per cent. of subacetate of lead, or finely powdered litharge, is then added, and the whole is shaken until all the color is destroyed. Powdered anhydrous carbonate of potash is next added until it sinks undissolved in the tube, even after prolonged agitation. The tube is then allowed to rest, when the alcohol is observed to float upon the surface of the water in a well-defined layer. The quantity read off on the scale of the tube and doubled, gives the percentage by volume of alcohol in the original liquid. The whole operation may be performed in about five minutes, and furnishes reliable approximative results. In many cases it is necessary to add the lead salt for the purpose of decolorizing the liquid. For the investigation of the amount of sugar in, or the concentration of the mash, or beer, a specially scaled hydrometer is used which is termed a saccharometer. Sugar possesses a higher degree of specific gravity than water, and hence it follows that the greater the amount of sugar in the mash the higher will be the specific gravity. The less the hydrometer sinks into the fluid the greater the amount of sugar present. Saccharometers are provided with thermometers whereby the reading may be corrected to a standard temperature, usually 59° F. The saccharometer is correct for solutions containing sugar alone but it is only approximately correct for mash liquor which contains a variety of other matters in variable quantities. It is a prime necessity that the distiller should be able to determine if the mash has been completely saccharified by the malt. For this purpose a solution of iodine is used. Iodine gives to starch a blue color. If the starch however, has been completely changed into sugar there will either be no discoloration or the filtered mash liquid which is at first a yellowish red becomes blue, then violet, and at last red. =Determination of the Purity of Alcohols.= While the knowledge of the amount of alcohol contained in a liquid is of great practical utility, this does not give any idea of the impurities present. An alcohol of 100 degrees or an absolute alcohol, may contain numerous impurities which may greatly affect its quality. It is therefore necessary in addition to analyze the purity of the alcohol. In commercial practice there are certain simple processes which will give a basis by which to determine the impurities left after distillation and rectification. These processes are largely empirical. They are based on the perception of the senses and are consequently of an entirely relative degree of precision. Nevertheless, when made by a practical expert, the operation may give very useful preliminary indications. This test is made in a glass of special shape broad at the bottom and narrowing at the top in order to concentrate the aroma of the product. Ordinary brandies are tested undiluted. Commercial alcohols, of about 95 degrees must be diluted with water to a maximum of 30 degrees. Otherwise the burning tang of the alcohol would preclude any delicacy of perception and allow impurities to pass unnoticed. The operation is begun by examination by sense of smell. The glass is half filled with the liquid diluted with one half of pure water. The glass is covered with one hand and shaken violently for a few seconds. Immediately upon uncovering it, the quality of the alcoholic vapors may be ascertained by their odor. For the examination by sense of taste, the operator rinses his mouth for a moment with the liquid itself. The taste of ethyl alcohol is fairly transient;--it disappears quickly allowing the taste of the accompanying foreign matter to be perceived almost immediately afterward. With a little practice this test enables one to distinguish by their flavor the primal origin of alcohols and to judge of their purity. Some professionals succeed by training in arriving at high degree of skill in the art of tasting alcohol as it should be done. In order to determine the purity of alcohol there are besides chemical tests used by the trade. These tests, which consist in characterizing and measuring separately the impurities which alcohol may contain, such as acids, ethers, aldehydes, bases, etc., belong exclusively to analytical chemistry; they are extremely delicate and complicated. We will not venture to touch upon them here. One of the simplest tests for purity is that of Barbet. This is based upon the time taken to discolor a solution of permanganate of potash under the action of the tested alcohol. It is not only very rapid but in general more practical than other tests. It allows the aggregate of the impurities contained in an alcohol to be ascertained in a single operation. The permanganate solution used is very weak (0. gr. 200 of salt), and of a violet-red color. The technique of the proceeding is as follows: 50 cubic centimeters of the alcohol to be tested are placed in a glass vessel the temperature of which is maintained at 64.40°F. 2 cubic centimeters of the permanganate solution are abruptly added and the time noted to within a second. Discoloration is awaited and as soon as it takes place the time is again noted. The total discoloration of the permanganate is not very marked and passes through intermediate stages; therefore it is preferable not to await complete discoloration but to stop at a pale salmon tint, which tint may be comparatively fixed by a sample of colored liquid (say a solution of fuchsine and chromate of potash). The comparative times of discoloration obtained by M. Barbet with various commercial alcohols, are as follows: Pure alcohol 43 min. 30 sec. Extra fine alcohol 5 " 30 " Semi fine alcohol 5 " 10 " Medium flavor alcohol (first running) 5 " 5 " Mediocre alcohol 5 " 11 " Medium flavor alcohol (last running) 2 " 12 " CHAPTER XII. DISTILLING PLANTS: THEIR GENERAL ARRANGEMENT AND EQUIPMENT. When we look at the manufactories of to-day with their complicated machinery, their extensive equipment, their great boilers, and engines and their hundreds of employees, we are liable to forget that good work was turned out by our ancestors, with equipment of extreme simplicity and that to-day while there are, for instance, thousands of wood-working mills, complete in every detail and covering under a multitude of roofs every variety of complicated and perfected wood-working machinery, yet there are many more thousands of small plants, comprising a portable boiler, fed with refuse, a small engine and a few saws which are making money for the owners and doing the work of the world. The reader therefore, must be warned against any feeling of discouragement because of the cost and complicated perfection of elaborate distilling plants. Where the business is to be entered into on a large scale, to take the products from a considerable section of country and turn them into alcohol to compete in the great markets, the best of apparatus and equipment is not too good, but the person contemplating the mere manufacture of alcohol on a small scale, to serve only a small section, must remember that distillation is really a very simple matter, for years practiced with a most rudimentary apparatus and still so practiced in the country districts particularly in the South. This is well illustrated by the fact that an illicit distiller confined in one of the North Carolina penitentiaries for transgressing the revenue laws, was able while in durance, to continue his operations unknown to the prison authorities, his plant consisting of a few buckets, and a still whose body was a tin kettle, a few pieces of pipe and a worm which he had bent himself. This example is not given as encouragement to illicit or "blockade" distilling but merely to show vividly how simple the rudimentary apparatus really is. The simplest regular plants, those of the South for instance, comprise a building of rough lumber some thirty feet by twelve wide, with a wooden floor on which the fermenting vats rest and an earthern floor immediately in front of the still and furnace. This is to permit the fires being drawn when the charge has been exhausted in the boiler. The still is of the fire-heated, intermittent variety, such as described on page 35. It consists of a brick furnace or oven, large enough to burn ordinary cord wood and supporting a copper boiler of fifteen or twenty gallons capacity. On top of this is a copper "head" with the usual goose neck, from which a copper pipe leads to a closed and locked barrel containing raw spirits, this barrel acting on the principle of the condensing chamber shown in the still in Fig. 8. From the upper part of this barrel, which acts as a concentrator, the vapors pass to a copper worm immersed in a tub of cold water. Here the vapors are condensed and pass by a pipe to a small room, containing a locked receiving tank. This room is kept locked and is under the immediate charge of the Government officer in charge of the still, or, in the case of alcohol intended for de-naturing, the alcohol would pass to a locked tank from whence it would be taken and de-natured under the charge of the proper Government officer. The fermenting vats may be six or more in number so as to allow the mash in each tank to be at a different stage of fermentation. A hand pump is used for pumping the contents of any of the tanks into the boiler or the still. A hand pump is also provided for supplying water to the vats and condensers. In connection with the distilling and fermenting building there are small buildings for storing the grain, malt, etc., for the storage of the alcohol and for the keeping of the various books, records, and stamps required by law. Such plants as these are located adjacent to a good clear spring or even a small brook, and preferably in a position convenient to the carriage of materials and the transportation of the whiskey or other liquor produced. The buildings are of the cheapest construction and arranged in the manner which compels the least labor in filling the mash vats and turning the contents into spirits. There are no special mash coolers, no complicated stirrers. The "beer" as the fermented mash is called is stirred by a paddle in the hands of a strong negro and the mash is mixed and fermented by rule of thumb, without the use of any scientific appliances. Primitive, as it is, however, those small plants in certain sections of the country make money for their proprietors and serve a large number of customers. The spirits so produced are low grade, fiery and rough in taste, but the point is that alcohol may be and is so produced. Between these simple beginnings and the elaborate plants of big distilleries there is a wide range, so wide that it is impossible within the limits of this book to go into detail. The makers of distilling apparatus furnish all grades of stills and to those contemplating erecting a plant it is suggested that their best course is to communicate with such manufacturers, giving the circumstances of the case, the particular product to be worked and the capacity desired. The object of this book is to give an understanding of the processes of distillation and of this chapter to give a general idea of the arrangement of a number of typical distilling plants, suitable for various kinds of work. That the simple, direct-heated pot still such as referred to above, used for fifteen hundred years and over, is still used is largely due to the simplicity of its construction and operation, but its capacity is small, and its operating expense relatively heavy. It is still used for making liquors, but for industrial purposes it has been entirely superceded by concentrating and rectifying stills. A simple form of the latter is found in the still shown in Fig. 11 and in the distilling apparatus of Adam (Fig. 9). Originally all stills were heated by direct contact with fire. This was open to a serious objection, namely, that the mash if thick was liable to be scorched. Stirring devices were used by Pistorious but these required constant attention. As a consequence, direct firing gave place to heating by steam, by which not only was scorching of the wash avoided but much greater certainty of operation was attained. The steam may be used to simply heat the boiler, thus taking the place of the direct heat of the fire, but it is far better in every way to admit the steam directly to the mash as in the Coffey still, Fig. 18, and all modern stills. It is possible to apply this principle to all compound stills, but the best results with greatest economy of fuel are, of course, gotten from the plate or column stills especially constructed for steam. In order to get the best results it is necessary that the entry of steam be regulated so that there may be absolute uniformity of flow. A convenient form of regulator is that invented by Savalle, and described on page 70, hut there are a number of other forms on the market each one having its special advantages. It will be seen then that while the simple pot still, fire-heated, may be used, the practical plant for the fermentation of industrial alcohol should have a modern continuous still and rectifier and a boiler for generating the necessary steam for it and for the operations of mashing and fermenting. THE FERMENTING ROOM. The fermenting room has three main requirements for successful commercial distillation. It must allow a uniform temperature to be maintained in the vats; it must have thorough ventilation without any draftiness, and it must be absolutely clean. It should have also plenty of light so that it may be thoroughly inspected. It is true that in the primitive plants all these requisites were violated, but there is no reason for this. The first cost is but little added to by building with these requisites in mind and it is far more profitable in the long run; and it is only by the elimination of the bacteria which are inimical to proper fermentation that the fermenting operation can be performed with any certainty. For the regulation of the temperature reliance may be had on stoves or heaters, or on special mash heaters and coolers by which the temperature of the mash in the tubs may itself be controlled without reference to the temperature of the fermenting room. When, however, no special and adequate-heating means is provided, the walls should be double with an air space between and the doors and windows should either be also double or limited in number. To ensure good ventilation and plenty of space above the vats wherein to work or install suitable vatting machinery, the walls should be at least twelve feet in height. Outlet openings should be formed around the base of the room leading to the outer air and closed by controllable shutters. These are to allow the escape of the carbonic acid gas evolved during fermentation. These should be most carefully constructed, however, to prevent drafts. The walls and floor of the fermenting rooms should be so made that they may be easily washed down and kept clean. Concrete floors are excellent for this purpose and the walls also may be faced with concrete or cement covered with a coating composed of a mixture of asphalt and coal tar. This mixture may be also applied to plaster walls with good results. The fermenting vats, as before stated, are made of wood for small plants, and of iron for larger plants, and are usually from three and a half to four and a half feet in height. After the chief fermenting period, it is necessary that the temperature of the mash be prevented from rising beyond 86° F. and to that end movable cooling tubes, coils and stirrers are used. These consist of parallel frames made up of tubes, preferably of copper, through which cold water is passed and which are moved about in the vat, either vertically or rotatively. There must be space above the vats, therefore, for the introduction and removal of these cooling frames, and for the gearing whereby they are driven. As previously stated, mashes to-day are mostly prepared by steaming and disintegrating in a mash cooker of the type shown in Figs. 1 and 41 or in Henze steamers, from which the mash is blown into the preparatory mash vat, where it is stirred and brought to the proper temperature for fermentation. A convenient arrangement of mash cooker, coolers, pump and vats is shown in Fig. 1. Where Henze steamers are used they are arranged in batteries, the blow-off pipes being connected to the preparatory mash vats. These are preferably provided with water cooled stirrers consisting of a frame of straight and vertical tubes mounted on a tubular arm projecting from a tubular shaft, and rotated in a horizontal plane within the closed mash vats, by suitable gears. The rotation of the arm stirs and automatically mixes the mash while cooling it. Another form of cooler is shown diagrammatically in Fig. 4. Whatever form of cooling apparatus is used, attention should be paid to the ease with which the stirrers or tubes can be kept clean, and to the strength of the apparatus, gears, etc. Concentrated or thick mashes require that the stirrers be of massive construction, capable of being rapidly rotated in the liquid. In preparatory mash vats for use with concentrated mashes, means must also be provided for clearing the mash. These mash cleaners and husk removers usually form part of, or are attached to the vat itself and are driven by gearing from the main shaft carrying power to the mashing room. A good idea of the general arrangement and correlation of the various apparatus of a plant may be gathered from the sectional view of a grain distillery shown in Fig. 55. It will be seen from this that the mashing apparatus, steamers and mixers are located on the several floors of one building and in such relation to each other that the several operations of saccharifying are carried on in a continuous movement of mash towards the fermenting vats. [Illustration: FIG. 55.--Continuous Grain Alcohol Distillery--Barbet's System.] Adjoining the fermenting vat room is a section of the plant given up to the manufacture of pure yeast and this and the fermenting rooms are level with the ground, have solid walls whereby a uniform temperature is obtained, and plenty of space for proper ventilation of the vats. A gallery traverses the room about midway the height of the vats so that convenient access may be had to them. The distilling room is high enough to allow for the setting of the various columns, separators and condensers at their proper heights relative to each other, and should be so arranged as to its several floors or stages that access to the various pipes and apparatus may be easily had. The steam generator for the column is located in an adjacent room. In addition to this there should be a malt house for the preparation of malt, located conveniently to the saccharifying building; an engine and boiler room so placed that power may be conveniently transferred to the mixers, stirrers and pumps and to generate steam for the Henze boilers; while adjacent to the distilling building should be the storage tanks and de-naturing department. [Illustration: FIG. 56.--Grain Distillery. Capacity 2,500 Bushels per day. (_To face page 198_)] Another arrangement of apparatus for a grain distillery with a capacity of 2500 bushels per day is illustrated in Fig. 56. This plant was erected by the Vulcan Copper Works Co., and includes separate stills for gin, alcohol, and rye whiskey, as well as a spirit rectifying column. The milling and grain mixing departments, the yeast room and the fermenting room are arranged on the several floors of one building, in the basement of which is located the vacuum cooker and drop tub and coolers described on page 11 from which the mash is pumped into the fermenting tubs. The second section of the building contains the distilling apparatus, storage tanks, charcoal rectifiers and spirit rectifying apparatus, while the third section of the building comprises the boiler house and engine room. [Illustration: FIG. 57--Small Beet Distillery.] In Fig. 57 is shown a view of a small plant for the distillation of beets, the figure giving a good idea of the arrangement of the diffusion battery in relation to the still and rectifier. The juice from the diffusion battery is pumped into the overhead tanks from which it descends into a dephlegmator and from thence into the still, the vapors from the still passing into the rectifier. The still is a direct, fire-heated still and adjacent to the still is a water heater from which the water passes to the hot water reservoir located above and to one side of the diffusion vats. [Illustration: FIG. 58.--Large Beet Distillery.] A large plant for the distillation of beets is shown in the Section Fig. 58. The beets from the beet silos are carried to suitable washing machines, _A_, see Chapter VII, in which they are thoroughly cleaned of dirt and gravel. From the washers they are lifted by a conveyor _B_ to a distributor _C_ by which they are conveyed to the cutters or slicers. These consist of horizontal apertured plates revolving at a high speed, and carry knives which plane off slices from the beets. These drop through the apertures of the plate and are conveyed to the diffusion batteries, as by a movable chute _D_ oscillated with a jigging motion through suitable gearing. The diffusers _F_ should be arranged so that small trucks may be driven beneath them to receive the spent slices and carry them to the spent beet silos. _U_ indicates a gauging tank into which the juice runs from the diffusers. From thence it passes to coolers (not seen) and thence to the fermentation tanks _G_. _R_ indicates a small engine for driving the beet slicers and _S_ a battery of pumps whereby the wash may be forced up into the reservoir _I_ from which the wash descends into the still _K_. _H_ and _J_ are reservoirs for hot and cold water respectively. From the distilling column _K_ the phlegm or raw spirit passes to the phlegm tank _L_ from which it is drawn as desired into the rectifying column _M_, thence into the coolers and condensers and thence into the alcohol tanks _N_. On the other side of the building as indicated by the chimney is the boiler for generating the motive power for the plant and for supplying the steam necessary for the distilling and rectifying columns and the hot water for the diffusion batteries. The boiler should be very capacious and it would be well to have two, one in reserve. If possible, advantage should be taken of the natural slope of the ground so that the trucks bringing beets from the silo to the washer and carrying the spent beets away may roll downward by their own weight. The silos for the spent beets should be excavated from the ground and the trucks be constructed to tip their contents into these pits. The natural slope of the bottom of these pits should drain away the water and means be provided whereby carts can load with the spent beets to carry them away. The spent liquors should flow off into ponds from which they may be drawn away to fertilize land. A very convenient method of carrying beets from the silos to the washing machine is by means of a narrow canal of rapidly flowing water, flowing between the silos and entering the washing machines. Beets pitched into this stream are carried along by the current to the washers and at the same time undergo a preliminary washing. By laying out a system of channels throughout the beet yard the labor of handling is reduced to a minimum. These channels may be covered by boards on which the beets may be piled. These may be lifted and the beets thereon dumped into the stream. A plant for the distillation of potatoes would be arranged very much after the plan of the grain distillery heretofore described except that it would have to be provided with apparatus for washing the potatoes and removing stones and adhering clods of earth. These washers, as put on the market, comprise a slotted rotating drum, which tumbles the potatoes about and loosens the dirt. When they escape from the drum they enter a washing trough where they are stirred about by revolving blades and acted upon by a swift current of water. The trough should be about two feet long to properly wash the potatoes. They are then lifted by an elevator to the mouth of the Henze pulpers (see Fig. 2) or the vacuum cookers see Fig. 1). It is of advantage that the washing apparatus be so located that the potatoes as they are received may be shoveled into it immediately. The scale for weighing the potatoes as they are brought in should be so located that the manager may attend to the weighing without having to leave the distillery. This and other like details may seem of small moment but it is care in such details which conduces to the success of a plant. As before stated in describing a beet distillery, advantage should be taken of the lay of the land in laying out the plant so that the spent pulp may be easily disposed of, the spent wash carried away, and the finished product conveniently handled. [Illustration: FIG. 59.--Molasses Distillery. Capacity 2,500 gallons per day.] In Fig. 59, is shown a plant for distilling molasses, designed by the Vulcan Copper Works, before referred to, and erected for the Rio Tamposo Sugar Co., of Tamposo, S. L. P., Mexico. The molasses as before explained at page 164 being too concentrated, is first pumped into the steam mixing tank on the ground floor of the distilling building. Here it is diluted and heated, mixed with sulphuric acid and pumped into the long ranges of cooling pipes, located along the fermenting room and built on the principle shown in Fig. 4. Here it is further diluted and yeast is added. From the fermenting tubs the molasses beer is pumped into the beer heater and thence into such a still as is shown in Fig. 32. In addition to this the plant contains a rectifying apparatus for the high wines produced by the beer still, comprising a spirit still, charged from a high wine tank, a rectifying column, separator, and tubular condenser from which the rectified spirit is carried to the storage tanks. Cane sugar distilleries are practically arranged the same as the molasses distillery above described. The cane is crushed between the rolls of cane crushers on the receiving floor and is then strained to remove the "begasse." The clarified juice is then pumped up to the mixing tanks. In these the molasses is mixed with spent wash from other fermentations or with water, after which it is acidified and flows to the fermenting vats. The fermenting house should be provided with means for forcing in filtered air and for ventilating, as molasses wash is very sensitive to change in temperature and very liable to become contaminated by injurious ferments. (See Fig. 60). [Illustration: FIG. 60.--Molasses Fermenting House.] Above each vat should be a cooling coil capable of being lowered into the vat and a water spraying pipe, whereby the mash may be diluted when desired. From the vats, the wash is pumped to the distilling and rectifying columns. In Jamaica the still shown in Fig. 37, is largely used, as also the Coffey still, Fig. 18. It is very often not profitable to distill spirit from molasses or sugar cane directly at the sugar factories, there being no market on the spot and transportation of the spirit in casks being very costly and difficult, not only because of the lack of transporting means but because the tropical climate tends to warp the empty casks. Transportation of the molasses in casks to a distillery is likewise open to objections of cost and the action of the hot sun in fermenting the molasses and bursting the cask. Barbet has suggested a way out of the difficulty. This consists in boiling the molasses in vacuo, and then running it into molds lined with sheets of paper. These are set by dipping in cold water. When set the loaves wrapped in their paper coverings are as easily handled as sugar loaves. There is no dead weight nor any "empties" to be returned as in the case of casks. The molasses is in a most concentrated form and this makes for economy in freight. There is no risk of deterioration and the loaves may be stored in an ordinary warehouse. This method allows the distillery to be located at centers of transportation or at seaports, while the sugar factories are on the plantation. Care should be taken in selecting the site for a distillery that an abundance of pure water may be supplied. The purer the water the better, and where water is not pure, purifying apparatus should be provided. The coolness of the water is a factor which must be taken into consideration. The greater amount of water will be used for cooling, and it follows then that the cooler the water the less of it will have to be used. The horse-power of the engines used in driving the distilling apparatus varies, of course, with the capacity of the still, the average being between 6 H.P. and 30 H.P., for plants having fermenting vats of capacities ranging between two hundred and fifty, and twelve hundred gallons. It must not be forgotten that the coal consumption of a plant depends upon the economy of heating means in the distilling apparatus, the perfection with which the heat of the vapors is used to heat the wash, the perfection of the boiler grates and the method of firing. These latter matters should be obvious to any distiller, but it is in economy in little things that the successful operation of a plant resides. Nothing is more surprising than the difference in the coal consumption of different distilleries. Some use a third more than others. This is caused by poor coal, by poor firing, by poor boilers, by hard water, or by poor distilling equipment. With regard to the latter this word of advice may be given: The greater the number of plates in the distilling column, the less the coal consumed per gallon of alcohol produced. It must, however, be taken into account that a large number of plates in a column means a column of considerable height and that in turn means a correspondingly tall still house and increased first cost. Hence it is more economical to use the best forms of traps on the plates and fewer plates, and the best forms of these traps as pointed out in Chapter III, are those wherein the largest quantity of vapor in a finely divided state may come into contact with the greatest number of liquid particles. In conclusion it may be said that dirt, neglect, carelessness and a too great desire for economy in first cost are all factors in lowering the economical productiveness as well in a distillery as in other manufacturing plants. CHAPTER XIII. DE-NATURED ALCOHOL AND DE-NATURING FORMULÆ The uses of alcohol are very numerous and varied, the principal being, of course, for the production of all alcoholic liquors such as brandy, gin, rum, whiskey, liquors, etc.; that distilled from grain is almost entirely consumed in the manufacture of whiskey, gin, and British brandy. In the arts, strong alcohol is employed by the perfumers and makers of essences for dissolving essential oils, soaps, etc., and for extracting the odor of flowers and plants; by the varnish-makers for dissolving resins; by photographers in the preparation of collodion; by the pharmaceutists in the preparation of tinctures and other valuable medicaments; by chemists in many analytical operations, and in the manufacture of numerous preparations; by instrument makers in the manufacture of delicate thermometers; by the anatomist and naturalist as an antiseptic; and in medicine, both in a concentrated form (rectified spirit), and diluted (proof spirit, brandy, etc.), as a stimulant, tonic, or irritant, and for various applications as a remedy. It is largely consumed in the manufacture of vinegar; and in the form of methylated spirit it is used in lamps for producing heat. It has, in fact, been employed for a multitude of purposes which it is almost impossible to enumerate. The common form of alcohol known as "de-natured spirit" consists of alcohol to which one tenth of its volume of wood alcohol, or other de-naturizing agents has been added, for the purpose of rendering the mixture undrinkable through its offensive odor and taste. Methylated spirit being sold tax free, may be applied by chemical manufacturers, varnish makers, and many others, to a variety of uses, to which, from its greater cost, duty-paid spirit is commercially inapplicable. Its use, however, in the preparation of tinctures, sweet spirits of nitre, etc., has been prohibited by law. It has often been attempted to separate the wood spirit from the alcohol, and thus to obtain pure alcohol from the mixture, but always unsuccessfully, as, although the former boils at a lower temperature than the latter, when boiled they both distil over together, owing probably to the difference of their vapor densities. It is Germany which has led the way in the manufacture and use of "de-natured" alcohol or "spiritus," as it is there known. Germany has no natural gas or oil wells, and gasoline and kerosene are not produced there, hence the necessity of using some other form of liquid fuel. This fuel--in many ways better than any petroleum product--was found in alcohol. The sandy plains of northern Germany, and indeed any agricultural district of that empire, produce abundant crops of potatoes and beets. From the first, alcohol can be so easily manufactured that the processes are within the understanding and ability of any farmer. The second is used in the manufacture of beet sugar,--one of the great German industries, and the crude molasses, from a refuse product,--still contains from 40 to 50 per cent. of sugar, from which alcohol can be made. Under these circumstances and the great demand for liquid fuel for motor carriages and gas engines, alcohol for "de-naturing" came rapidly to the front as one of the most important of agricultural products, as one of the most valuable "crops" which a farmer could raise. Potatoes are chiefly raised. The potatoes are grown by the farmers and manufactured into alcohol in individual farm distilleries and in cooperative distilleries. While England and France were somewhat behind Germany in fostering this industry--yet they both were far ahead of the United States in this matter. De-natured alcohol could be readily gotten in these countries, for industrial purposes, while the United States continued to charge a high internal revenue tax on all but wood alcohol. This prevented the use of alcohol in competition with gasoline or kerosene, and limited its use in arts and manufactures. On June 7, 1906, however, Congress passed the "De-naturing Act," as it is called, which provided in brief that alcohol, which had been mixed with a certain proportion of de-naturing materials sufficient to prevent its use as a beverage should not be taxed. The passage of this Act was alcohol's new day, and is destined to have a wide influence upon the agricultural pursuits of the country. In the matter of small engines and motors alone one estimate places the farm use of these at three hundred thousand with an annual increase of one hundred thousand. This means an economical displacing of horse and muscle power in farm work almost beyond comprehension. If now the farmer can make from surplus or cheaply grown crops the very alcohol which is to furnish the cheaper fuel for his motors, he is placed in a still more independent and commanding position in the industrial race. As an illuminant the untaxed alcohol is bound to introduce some interesting as well as novel conditions. The general estimate of the value of alcohol for lighting gives it about double the power of kerosene, a gallon of alcohol lasting as two gallons of the oil. In Germany, where the use of alcohol in lamps is most fully developed, a mantle is used. Thus in a short time it may be expected that an entirely new industry will spring up to meet the demand for the illuminating lamps embodying the latest approved form of mantle. The adapting of the gasoline motors of automobiles to alcohol fuel will in itself create a vast new manufacturing undertaking. When this is accomplished it is believed that we shall no more be troubled with the malodorous gasoline "auto" and "cycle" burners on our public streets and parkways. De-natured alcohol is simply alcohol which has been so treated, as to spoil it for use as a beverage or medicine, and prevent its use in any manner except for industrial purposes. De-naturing may be accomplished in many ways. In England a mixture suitable for industrial purposes, but unfit for any other use, is made by mixing 90 per cent. of ethyl alcohol (alcohol made from grain, potatoes, beets, etc.), with 10 per cent. of methyl or "wood alcohol." Under the new law the proportion of wood alcohol is cut to five per cent. In Canada "methylated spirits," as it is known, is composed of from 25 per cent. to 50 per cent. of wood alcohol mixed with ethyl alcohol. This proportion of wood alcohol is far more than is required in any other country. In Germany, the de-naturing law passed in 1887 was so framed as to maintain the high revenue tax on alcohol intended for drinking, but to exempt from taxation such as should be de-naturized and used for industrial purposes. De-naturing is accomplished by mixing with the spirit a small proportion of some foreign substance, which, while not injuring its efficiency for technical uses, renders it unfit for consumption as a beverage. The de-naturing substances employed depend upon the use to which the alcohol is to be subsequently applied. They include pyridin, picolin, benzol, toluol, and xylol, wood vinegar, and several other similar products. As a result of this system Germany produced and used last year 100,000,000 gallons of de-natured spirits, as compared with 10,302,630 gallons used in 1886, the last year before the enactment of the present law. The following are some of the other de-naturants used in Germany: Camphor, oil of turpentine, sulphuric ether, animal oil, chloroform, iodoform, ethyl bromide, benzine, castor oil, lye. * * * * * In France the standard mixture consists of: 150 liters of Ethyl alcohol, 15 liters of wood alcohol, 1/2 liter of heavy benzine, 1 gram. Malachite green. An illustration of de-naturing on a large scale is given by the methods and operations of a large London establishment. On the ground floor are four large iron tanks holding about 2500 gallons each. On the next floor are casks of spirit brought under seal from the bonded warehouse. On the third floor are the wood alcohol tanks, and on the fourth floor cans of methylating materials. On the fourth floor the covers to the wood alcohol tanks were removed (these tank covers were flush with that floor) and the contents gauged and tested. The quantity to be put into the tanks on the first floor was run off through pipes connecting with the first-floor tanks and the upper tanks relocked. Then going to the second floor, each cask of the grain spirit was gauged and tested and the tank covers, which were flush with the floor, were removed and the casks of the grain spirit were run into the tanks below. The mixture was then stirred with long-handled wooden paddles and the tank covers replaced, and the material was ready for sale free of tax. The mixture was 10 per cent. wood alcohol and 90 per cent. ethyl alcohol made from molasses, and was what is known as the ordinary methylating spirit used for manufacturing purposes only and used under bond. The completely de-natured spirit is made by adding to the foregoing three-eighths of one per cent. of benzine. This benzine prevents re-distillation. In the United States there are at present two general formulas for de-natured alcohol in use, either one of which may be used by any manufacturer, who can use de-natured alcohol. The first and most common one is made up as follows: Ethyl Alcohol 100 gallons. Methyl " 10 " Benzine 1/2 " Where such a formula as this is required in an aqueous solution the benzine is of course thrown out, giving the solution a milky appearance. In this case the other general formula may be used. Ethyl Alcohol 100 gallons. Methyl " 2 " Pyridine Bases 1/2 " In addition to these two general formulas for de-natured alcohol a number of special formulas have been authorized to be used in the manufacture of certain classes of goods. In order to buy these specially de-natured alcohols it is necessary, of course, to obtain a permit first from your Collector of Internal Revenue, a simple permit to use de-natured alcohol will not suffice. Some of the special formulas are as follows: For use in the manufacture of sulphonmethane. Ethyl Alcohol 100 gallons. Pyridin Bases 1 gallon. Coal Tar Benzol 1 " For use in the manufacture of transparent soap. Ethyl Alcohol 100 gallons. Methyl " 5 " Castor Oil 1 " 36° Be. Caustic Soda Solution 1/2 " For the manufacture of shellac varnishes. Ethyl Alcohol 100 parts by volume Methyl " 5 " " " For the manufacture of smoking and chewing tobacco. Ethyl Alcohol 100 gallons. A mixture made as follows: 1 " Aqueous Solution containing 40% Nicotine 12 gallons Acid Yellow Dye 0.4 lb. Tetrazo Brilliant Blue 12 B Conct. 0.4 lb. Water to make 100 gallons. For the manufacture of photo-engravings. Ethyl Alcohol 100 gallons. Sulphuric Ether 65 lbs. Cadmium Iodide 3 " Ammonium " 3 " For the manufacture of fulminate of mercury. Ethyl Alcohol 100 gallons. Methyl " 3 " Pyridine Bases 1/2 " The next formula may be used for the following purposes: In the manufacture of photographic dry plates. In the manufacture of embalming fluid. In the manufacture of heliotropin. In the manufacture of resin of podophyllum and similar products. In the manufacture of lacquers from soluble cotton. In the manufacture of thermometer and barometer tubes. Ethyl Alcohol 100 gallons. Methyl " 5 " For use in the manufacture of photographic collodian. Ethyl Alcohol 100 gallons. Sulphuric Ether 10 lbs. Cadmium Iodine 10 " For use in the manufacture of pastes and varnishes from soluble cotton. Ethyl Alcohol 100 gallons. Methyl " 2 " Benzol 2 " For use in the purification of rubber. Ethyl Alcohol 100 gallons. Acetone 10 " Petroleum naptha 2 " Petroleum naptha must have a specific gravity of not less than ·650 nor more than ·720 at 60°F. For use in the manufacture of watches. Ethyl Alcohol 100 gallons. Methyl " 5 " Cyanide of Potassium 1-1/2 lbs. Patened Blue B 1/8 oz. (Acid calcium, magnesium, or sodium salt of the disulpho-acids of meta-oxytetraethyldiamidotri-phenyl-carbidrids.) The methyl alcohol must have a specific gravity of not more than ·810 at 60° F. The de-naturing mixture is best prepared by dissolving the cyanide of potassium in a small quantity of water, and then adding this solution to the alcohol, with which the methyl alcohol, containing the dissolved color, has been previously mixed. For the manufacture of celluloid, pyralin and similar products. Ethyl Alcohol 100 parts by volume Methyl " 5 " " " Camphor 7 lbs. Alternative special de-naturant for the manufacture of celluloid, pyralin and similar products. Ethyl Alcohol 100 gallons. Methyl " 2 " Benzol 2 " The strongest alcohol of commerce in the United States is usually 95 per cent. alcohol, and the price varies from $2.30 to $2.50 per gallon, showing that the greater part of the cost is due to the revenue levied by the government. The greater part of the 60,000,000 gallons of alcohol consumed in the United States is used in the manufacture of whiskey and other beverages. The revenue tax prevents the use of alcohol to any great extent in the industries of the country. The bill passed by Congress in 1906, designed to promote the use of untaxed alcohol in the arts and as fuel, took effect January 1, 1907. The first effect of free alcohol would, it was said, supplant the 12,000,000 gallons of wood alcohol which are used in the manufacture of paint, varnishes, shellacs, and other purposes. Another use that is expected of de-natured alcohol is in the manufacture of certain products, such as dyestuffs and chemicals, which can not now be manufactured commercially in this country because of the high cost of alcohol, and which are imported largely from Europe. A very rapid development of the industry of manufacturing chemicals as a result of free alcohol is looked for. In the production of alcohol there is always formed as a by-product a certain amount of fusel oil, which is very useful in manufacturing lacquers which are used on metallic substances, fine hardware, gas fixtures, and similar articles. The industries manufacturing these wares will undoubtedly receive a great stimulus as a result of cheaper fusel oil caused by the increased production of alcohol. =A Safe Fuel.= The use of de-natured alcohol as a fuel has yet to be fully developed. Although alcohol has only about half the heating power of kerosene or gasoline, gallon for gallon, yet it has many valuable properties which may enable it to compete successfully in spite of its lower fuel value. In the first place it is very much safer. Alcohol has a tendency to simply heat the surrounding vapors and produce currents of hot gases which are not usually brought to high enough temperature to inflame articles at a distance. It can be easily diluted with water, and when it is diluted to more than one-half it ceases to be inflammable. Hence it may be readily extinguished; while burning gasoline, by floating on the water, simply spreads its flame when water is applied to it. Although alcohol has far less heating capacity than gasoline, the best experts believe that it will develop a much higher percentage of efficiency in motors than does gasoline. Since gasoline represents only about two per cent. of the petroleum which is refined, its supply is limited and its price must constantly rise in view of the enormous demand made for it for automobiles and gasoline engines in general. This will open a new opportunity for de-natured alcohol. Industrial alcohol is now used in Germany in small portable lamps, which give it all the effects of a mantel burner heated by gas. The expense for alcohol is only about two-thirds as much per candle-power as is the cost of kerosene. Even at 25 or 30 cents a gallon, de-natured alcohol can successfully compete with kerosene as a means of lighting. Objection has been made to the use of alcohol in automobiles and other internal-explosive engines, that it resulted in a corrosion of the metal. This is vigorously denied by the advocate of alcohol fuel and the denial is backed by proofs of the use of alcohol in German engines for a number of years without any bad results. A recent exhibition in Germany gave a good illustration of the broad field in which de-natured alcohol may be used. Here were shown alcohol engines of a large number of different makes, alcohol boat motors as devised for the Russian navy, and motors for threshing, grinding, wood-cutting, and other agricultural purposes. The department of lighting apparatus included a large and varied display of lamps, chandeliers, and street and corridor lights, in which alcohol vapor is burned like gas in a hooded flame covered by a Welsbach mantle. Under such conditions alcohol vapor burns with an incandescent flame which rivals the arc light in brilliancy and requires to be shaded to adopt it to the endurance of the human eye. There has been each year a great improvement in the artistic models and finish of lamps and chandeliers for alcohol lighting. At the beginning they were simple and of rather ordinary appearance, but now they are up to the best standard of modern fixtures for gas and electricity, with which alcohol lighting is now competing with increasing success in that country. Similarly attractive and interesting was the large display of alcohol heating stoves, which, for warming corridors, sleeping rooms, and certain other locations, are highly esteemed. They are made of japanned-iron plate in decorative forms, with concave copper reflectors, are readily portable, and, when provided with chimney connections for the escape of the gases of combustion, furnish a clean, odorless, and convenient heating apparatus. Cooking stoves of all sizes, forms, and capacities, from the complete range, with baking and roasting ovens, broilers, etc., to the simple tea and coffee lamp, were also displayed in endless variety. Enough has been said to give an idea of the capabilities and values of this new form of fuel,--at least, and as far as the United States is concerned. With its advent not only will American genius perfect the machinery for its use, but the American farmer is given a new market for his crops. Distilleries, big and little, are likely to be set up all over the country, and the time is not far distant when the farmer will be able to carry his corn to his local distillery, and either return with the money in his pocket, or with fuel for farm engines, machinery, and perchance his automobile. When our government shall have become as far-sighted as the German government in this matter, every farmer will be able to manufacture his own de-natured spirits. The wisdom of the German system established by the law of 1887 has long ceased to be a question of debate. For every reichsmark of revenue sacrificed by exempting de-natured spirits from taxation the empire and its people have profited ten-fold by the stimulus which has been thereby given to agriculture and the industrial arts. CHAPTER XIV. THE FREE ALCOHOL ACT OF 1906, THE AMENDMENT OF 1907 AND INTERNAL REVENUE REGULATIONS. PUBLIC--NO. 201. An Act for the withdrawal from bond, tax free, of domestic alcohol when rendered unfit for beverage or liquid medicinal uses by mixture with suitable de-naturing materials. _Be it enacted by the Senate and House of Representatives of the United States of America in Congress assembled_, That from and after January first, nineteen hundred and seven, domestic alcohol of such degree of proof as may be prescribed by the Commissioner of Internal Revenue, and approved by the Secretary of the Treasury, may be withdrawn from bond without the payment of internal-revenue tax, for use in the arts and industries, and for fuel, light, and power, provided said alcohol shall have been mixed in the presence and under the direction of an authorized Government officer, after withdrawal from the distillery warehouse, With methyl alcohol or other de-naturing material or materials, or admixture of the same, suitable to the use for which the alcohol is withdrawn, but which destroys its character as a beverage and renders it unfit for liquid medicinal purposes; such de-naturing to be done upon the application of any registered distillery in de-naturing bonded warehouses specially designated or set apart for de-naturing purposes only, and under conditions prescribed by the Commissioner of Internal Revenue with the approval of the Secretary of the Treasury. The character and quantity of the said de-naturing material and the conditions upon which said alcohol may be withdrawn free of tax shall be prescribed by the Commissioner of Internal Revenue, who shall, with the approval of the Secretary of the Treasury, make all necessary regulations for carrying into effect the provisions of this Act. Distillers, manufacturers, dealers and all other persons furnishing, handling or using alcohol withdrawn from bond under the provisions of this Act shall keep such books and records, execute such bonds and render such returns as the Commissioner of Internal Revenue, with the approval of the Secretary of the Treasury, may by regulation require. Such books and records shall be open at all times to the inspection of any internal-revenue officer or agent. SEC. 2. That any person who withdraws alcohol free of tax under the provisions of this Act and regulations made in pursuance thereof, and who removes or conceals same, or is concerned in removing, deposting or concealing same for the purpose of preventing the same from being de-natured under governmental supervision, and any person who uses alcohol withdrawn from bond under the provision of section one of this Act for manufacturing any beverage or liquid medicinal preparation, or knowingly sells any beverage or liquid medicinal preparation made in whole or in part from such alcohol, or knowingly violates any of the provisions of this Act, or who shall recover or attempt to recover by redistillation or by any other process or means, any alcohol rendered unfit for beverage or liquid medicinal purposes under the provisions of this Act, or who knowingly uses, sells, conceals, or otherwise disposes of alcohol so recovered or redistilled, shall on conviction of each offense be fined not more than five thousand dollars, or be imprisoned not more than five years, or both, and shall, in addition, forfeit to the United States all personal property used in connection with his business, together with the buildings and lots or parcels of ground constituting the premises on which said unlawful acts are performed or permitted to be performed: _Provided_, That manufacturers employing processes in which alcohol, used free of tax under the provisions of this Act, is expressed or evaporated from the articles manufactured, shall be permitted to recover such alcohol and to have such alcohol restored to a condition suitable solely for reuse in manufacturing processes under such regulations as the Commissioner of Internal Revenue, with the approval of the Secretary of the Treasury, shall prescribe. SEC. 3. That for the employment of such additional force of chemists, internal-revenue agents, inspectors, deputy collectors, clerks, laborers, and other assistants as the Commissioner of Internal Revenue, with the approval of the Secretary of the Treasury, may deem proper and necessary to the prompt and efficient operation and enforcement of this law, and for the purchase of locks, seals, weighing beams, gauging instruments, and for all necessary expenses incident to the proper execution of this law, the sum of two hundred and fifty thousand dollars, or so much thereof as may be required, is hereby appropriated out of any money in the Treasury not otherwise appropriated, said appropriation to be immediately available. For a period of two years from and after the passage of this Act the force authorized by this section of this Act shall be appointed by the Commissioner of Internal Revenue, with the approval of the Secretary of the Treasury, and without compliance with the conditions prescribed by the Act entitled "An Act to regulate and improve the civil service," approved January sixteenth, eighteen hundred and eighty-three, and amendments thereof and with such compensation as the Commissioner of Internal Revenue may fix, with the approval of the Secretary of the Treasury. SEC. 4. That the Secretary of the Treasury shall make full report to Congress at its next session of all appointments made under the provisions of this Act, and the compensation paid thereunder, and of all regulations prescribed under the provisions hereof, and shall further report what, if any, additional legislation is necessary, in his opinion, to fully safeguard the revenue and to secure a proper enforcement of this Act. Approved June 7, 1906. DE-NATURING REGULATIONS UNDER THE ACT OF JUNE 7, 1906. Under the Act quoted above, the Commissioner of Internal Revenue was empowered to make regulations whereby the law might be carried into effect. In the first place it may be said that those who are permitted by this Act to manufacture de-natured alcohol must be distillers; in other words, those who have regularly licensed and registered distilleries. This does not mean that the plant must be large or costly--as witness the numerous little "stills" to be found throughout the South; but that the still, whatever its size, must be under constant supervision, and regularly licensed to manufacture alcohol. The requirements to this end can be had from the Commissioner of Internal Revenue, Treasury Department, Washington. Pursuant to the law regarding de-naturing, rules and regulations have been drawn up of which the following is a synopsis with extracts where deemed advisable. DE-NATURING BONDED WAREHOUSES. "SEC. 2. The proprietor of any registered distillery may withdraw from his distillery warehouse, free of tax, alcohol of not less than 180 degrees proof or strength, to be de-natured in the manner hereinafter prescribed. A distiller desiring to withdraw alcohol from bond for de-naturing purposes under the provisions of this act shall, at his own expense, provide a de-naturing bonded warehouse, to be situated on and constituting a part of the distillery premises. It shall be separated from the distillery and the distillery bonded warehouse and all other buildings, and no windows or doors or other openings shall be permitted in the walls of the de-naturing bonded warehouse leading into the distillery, the distillery bonded warehouse or other room or building, except as hereinafter provided. It must be constructed in the same manner as distillery bonded warehouses are now constructed, with view to the safe and secure storage of the alcohol removed thereto for de-naturing purposes and the de-naturing agents to be stored therein. It must be approved by the Commission of Internal Revenue. It shall be provided with closed mixing tanks of sufficient capacity. The capacity in wine gallons of each tank must be ascertained and marked thereon in legible letters, and each tank must be supplied with a graduated glass gauge whereon the contents will be at all times correctly indicated. All openings must be so arranged that they can be securely locked. Suitable office accommodation for the officer on duty must be provided. SEC. 3. The de-naturing bonded warehouse shall be used for de-naturing alcohol, and for no other purpose, and nothing shall be stored or kept therein except the alcohol to be de-natured, the materials used as de-naturants, the de-natured product, and the weighing and gauging instruments and other appliances necessary in the work of de-naturing, measuring, and gauging the alcohol and de-naturing materials. These bonded warehouses must be numbered serially in each collection district, and the words "De-naturing bonded warehouse No.--, district of--," must be in plain letters in a conspicuous place on the outside of the building. In case the distiller's bond has been executed before the erection of such warehouse the consent of the sureties to the establishment of the de-naturing warehouse must be secured and entry duly signed made on the bond." DE-NATURING MATERIAL ROOM. "SEC. 4. There shall be provided within the de-naturing bonded warehouse a room to be designated as the de-naturing material room. This room is to be used alone for the storage of de-naturing materials prior to the de-naturing process. It must be perfectly secure, and must be so constructed as to render it impossible for anyone to enter during the absence of the officer in charge without the same being detected. The ceiling, inside walls, and floor of said room must be constructed of brick, stone, or tongue-and-groove planks. If there are windows in the room the same must be secured by gratings or iron bars, and to each window must be affixed solid shutters of wood or iron, constructed in such manner that they may be securely barred and fastened on the inside. The door must be substantial, and must be so constructed that it can be securely locked and fastened. SEC. 5. At least two sets of tanks or receptacles for storing de-naturing material must be provided, and each set of tanks must be of sufficient capacity in the aggregate to hold the de-naturing material which it is estimated the distiller will use for thirty days. A set of tanks shall consist of one or more tanks for storing methyl alcohol, and one or more tanks of smaller capacity for storing other de-naturing materials. The capacity of each tank must be ascertained and marked in legible figures on the outside. The tanks must not be connected with each other, and must be so constructed as to leave at least 18 inches of open space between the top of the tank and ceiling, the bottom of the tank and the floor, and the sides of the tank and walls of the de-naturing material room. Each tank shall be given a number,and this number must be marked upon it. There shall be no opening at the top except such as may be necessary for dumping the de-naturing material into the tank and thoroughly plunging or mixing the same. Said opening must be covered so that it may be locked. Likewise the faucet through which the de-naturing material is drawn must be so arranged that it can be locked. Each tank must be supplied with a graduated glass gauge whereby the contents of the tank will always be shown." CUSTODY OF DE-NATURING BONDED WAREHOUSE. "SEC. 6. The de-naturing bonded warehouse shall be under the control of the collector of the district and shall be in the joint custody of a storekeeper, storekeeper-gauger, or other designated official and the distiller. No one shall be permitted to enter the warehouse except in the presence of said officer, and the warehouse and room shall be kept closed and the doors, exterior and interior, securely locked except when some work incidental to the process of de-naturing and storing material is being carried on. Standard Sleight locks shall be used for locking the de-naturing bonded ware-house and the de-naturing material room, and they shall be sealed in the same manner and with the same kind of seals as distillery bonded warehouses and cistern rooms are now sealed. Miller locks shall be used in securing the faucets and openings of the mixing tanks and the de-naturing material tanks. The officer in charge of the de-naturing bonded warehouse, material room, and tanks shall carry the keys to same, and under no circumstances are said keys to be intrusted to anyone except another officer who is duly authorized to receive them." APPLICATION FOR APPROVAL OF DE-NATURING BONDED WAREHOUSE. "SEC. 7. Whenever a distiller wishes to commence the business of de-naturing alcohol he must make written application to the collector of the district in which the distillery is located for the approval of a de-naturing bonded warehouse. Such application must give the name or names of the person, firm, or corporation operating the distillery, the number of the distillery, the location of the same, the material of which the warehouse is constructed, the size of same, width, length and height, the size of the de-naturing material room therein, and the manner of its construction, the capacity in gallons of each tank to be used for de-naturing alcohol or for holding the de-naturing agents, and the material of which said tanks are constructed. Such application must be accompanied by a diagram correctly representing the warehouse, the mixing tanks, de-naturing material room, and de-naturing material tanks, with all openings and surroundings. It must show the distillery and all the distillery bonded warehouses on the premises, with dimensions of each." Sections 9 and 10 of the regulations deal with the examination and approval of the de-naturing warehouse and plant by the Internal Revenue officers. DE-NATURING WAREHOUSE BOND TO BE GIVEN. "SEC. 11. After receipt of notice of the approval of said warehouse the distiller may withdraw from his distillery warehouse, free of tax, alcohol of not less than 180 degrees proof or strength, and may de-nature same in said de-naturing warehouse in the manner hereinafter indicated, provided he shall first execute a bond in the form prescribed by the Commissioner of Internal Revenue, with at least two sureties, Unless, under the authority contained in an act approved August 13, 1894, a corporation, duly authorized by the Attorney-General of the United States to become a surety on such bond, shall be offered as a sole surety thereon. The bond shall be for a penal sum of not less than double the tax on the alcohol it is estimated the distiller will de-nature during a period of 30 days, and in no case is the distiller to withdraw from bond for de-naturing purposes and have in his de-naturing warehouse in process of de-naturation a quantity of alcohol the tax upon which is in excess of the penal sum of the bond. SEC. 12. If at any time, it should develop that the de-naturing warehouse bond is insufficient the distiller must give additional bond. SEC. 13. The bond herein provided for must be executed before the distiller can withdraw from distillery bonded warehouse, free of tax, alcohol to be de-natured, and if he desires to continue in the business of de-naturing alcohol, said bond must be renewed on the first day of May of each year or before any alcohol is withdrawn from bond for de-naturing purposes. It must be executed in duplicate in accordance with instructions printed thereon. One copy is to be retained by the collector and one copy is to be transmitted to the Commissioner of Internal Revenue." CONDITIONS UNDER WHICH ALCOHOL IS WITHDRAWN. "SEC. 15. Not less than three hundred (300) wine gallons of alcohol can be withdrawn at one time for de-naturing purposes. When a distiller, who is a producer of alcohol of not less than 180 degrees proof and who has given the de-naturing warehouse bond as aforesaid desires to remove alcohol from the distillery bonded warehouse for the purpose of de-naturing, he will himself, or by his duly authorized agent, file with the collector of internal revenue of the district in which the distillery is located, notice to that effect." Upon the receipt of this notice (the form for which is given in the Regulations) the collector for the district will order a gauger to inspect the alcohol so withdrawn, and to gauge the same, and to make report; and directions are given to the official "storekeeper" to permit the transferral of the spirits to the de-naturing warehouse. SPIRITS TRANSFERRED TO BE MARKED. "Upon receipt of the permit by the storekeeper the packages of distilled spirits described in notice of intention to withdraw may be withdrawn from distillery bonded warehouse without the payment of the tax, and may be transferred to the de-naturing bonded warehouse on the distillery premises; but before the removal of said spirits from the distillery bonded warehouse, the gauger, in addition to marking, cutting, and branding the marks usually required on withdrawal of spirits from warehouse, will legibly and durably mark on the head of each package, in letters and figures not less than one-half an inch in length, the number of _proof_ gallons then ascertained, the date of the collector's permit, the object for which the spirits were withdrawn, and his name, title, and district. Such additional marks may be as follows: Withdrawn under permit issued Jan'y. 10, 1907 For De-naturing Purposes Proof gallons, 84 William Williams, U. S. Gauger, 5th Dist. Ky." SPIRITS TRANSFERRED TO DE-NATURING BONDED WAREHOUSE. "SEC. 20. When the packages of spirits are marked and branded in the manner above indicated they shall at once, in the presence and under the supervision of the storekeeper, be transferred to the de-naturing bonded warehouse." RECORD OF SPIRITS RECEIVED IN DE-NATURING BONDED WAREHOUSE. "SEC. 21. The officer in charge of the de-naturing bonded warehouse shall keep a record of the spirits received in said de-naturing bonded warehouse from the distillery bonded warehouse and the spirits delivered to the distiller for de-naturing purposes. Upon the _debit_ side of said record, in columns prepared for the purpose, there shall be entered the date when any distilled spirits were received in de-naturing bonded warehouse, the date of the collector's permit, the date of withdrawal from distillery bonded warehouse, the number of packages received, the serial numbers of the packages, the serial numbers of the distillery warehouse stamps, and the wine and proof gallons. Upon the _credit_ side of said record shall be entered the date when any spirits were delivered to the distiller for de-naturing purposes, the date of the collector's permit for withdrawal, the date of withdrawal from distillery bonded warehouse, the number of packages so delivered, the serial numbers of the packages, the serial numbers of the distillery warehouse stamps, and the wine and proof gallons. Immediately upon the receipt of any distilled spirits in the de-naturing bonded warehouse, and on the same day upon which they are received, the officer must enter said spirits in said record. Likewise, on the same date upon which any spirits are delivered to the distiller for de-naturing purposes, said spirits must be entered on said record. SEC. 22. A balance must be struck in the record described in above section at the end of the month showing the number of packages and quantity in wine and proof gallons of spirits on hand in packages on the first day of the month, the number of packages and quantity in wine and proof gallons received during the month, the number of packages and quantity in wine and proof gallons delivered to the distiller during the month, and the balance on hand in packages and wine and proof gallons at the close of the month." Sections 23 to 25 of the Rules relate to the duties of the Internal Revenue officers in making reports and returns. DE-NATURING AGENTS. COMPLETELY DE-NATURED ALCOHOL. "SEC. 26. Unless otherwise specially provided, the agents used for de-naturing alcohol withdrawn from bond for de-naturing purposes shall consist of methyl alcohol and benzine in the following proportions: To every 100 parts by volume of ethyl alcohol of the desired proof (not less than 180°) there shall be added 10 parts by volume of approved methyl alcohol and one-half of one part by volume of approved benzine; for example, to every 100 gallons of ethyl alcohol (of not less than 180 degrees proof) there shall be added 10 gallons of approved methyl alcohol and one-half gallon of approved benzine. Alcohol thus de-natured shall be classed as completely de-natured alcohol. Methyl alcohol and benzine intended for use as de-naturants must be submitted for chemical test and must conform to the specifications which shall be hereafter duly prescribed." DE-NATURANTS DEPOSITED IN WAREHOUSE. "SEC. 27. As the distiller's business demands, he may bring into the de-naturing bonded warehouse, in such receptacles as he may wish, any authorized de-naturant. Such de-naturants shall at once be deposited in the material room; thereafter they shall be in the custody and under the control of the officer in charge of the warehouse. Before any de-naturant is used it must be dumped into the appropriate tank and after the contents have been thoroughly mixed, a sample of one pint taken therefrom. This sample must be forwarded to the proper officer for analysis. The officer will then securely close and seal the tank. No part of the contents of the tank can be used until the sample has been officially tested and approved, and report of such test made to the officer in charge of the warehouse. If the sample is approved the contents of the tank shall upon the receipt of the report, become an approved de-naturant and the officer shall at once remove the seals and place the tank under Government locks. If the sample does not meet the requirements of the specifications, the officer shall, upon the receipt of the report of non-approval, permit the distiller, provided he desires, to treat or manipulate the proposed de-naturant so as to render it a competent de-naturant. In such case another sample must be submitted for approval. If the distiller does not desire to further treat the de-naturant the officer shall require him immediately to remove the contents of the tank from the premises." RECORD OF DE-NATURANTS RECEIVED. "SEC. 28. The officer shall keep a de-naturing material room record. This record shall show all material entered into and removed from the de-naturing material room. There shall be proper columns on the _debit_ side in which are to be entered the date when any material is received, the name and residence of the person from whom received, the kind of material, the quantity in wine gallons, and, if methyl alcohol, in proof gallons, the date upon which the material was dumped into the tank, the number of the tank, the date upon which sample was forwarded, and the number of the sample, and the result of the official test. On the _credit_ side of said record shall be entered in proper columns the date upon which any material was removed from the de-naturing material room for de-naturing purposes, the kind of material, the number of the tank from which taken, the number of the sample representing the tank and sent for official test, the number of wine gallons, and, if methyl alcohol, the number of proof gallons." MONTHLY RETURNS OF DE-NATURANTS RECEIVED. "SEC. 29. A balance shall be struck in this record at the end of each month whereby shall be shown the quantity of material of each kind on hand in the de-naturing material room on the first day of the month, the quantity received during the month, the quantity rejected and removed from the premises during the month, and the quantity delivered to the distiller for de-naturing purposes during the month, and the quantity on hand at the end of the month. The officer shall, at the end of each month, prepare in duplicate, sign, and forward to the collector of internal revenue a report which shall be a transcript of said record." DISTILLER TO KEEP RECORD OF DE-NATURANTS. "SEC. 30. The distiller shall also keep a record, in which he shall enter the date upon which he deposits any material in the tanks of the de-naturing material room, the name and address of the person from whom said material was received, and the kind and quantity of the material so deposited; also he shall enter in said record the date upon which he receives any material from the de-naturing material room, the kind and quantity of such material so received, and the disposition made of same." NOTICE OF INTENTION TO DE-NATURE SPIRITS. "SEC. 31. The distiller shall, before dumping any spirits or de-naturants into the mixing tank, give notice to the officer in charge of the de-naturing warehouse in proper form in duplicate, and enter in the proper place thereon (in the case of distilled spirits) and in the proper column the number of the packages, the serial numbers of same, the serial number of the warehouse stamps, the contents in wine and proof gallons and the proof as shown by the marks, the date of the withdrawal gauge, and by whom gauged. In case of de-naturing agents he shall enter in the proper place and in the proper columns the number of gallons, the kind of material, and the number of the de-naturing material tank from which same is to be drawn. The contents of the several packages of alcohol, as shown by the withdrawal gauge, shall be accepted as the contents of said packages when dumped for de-naturing purposes unless it should appear from a special showing made by the distiller that there has been an accidental loss since withdrawal from distillery bonded warehouse. Upon receipt of this notice the officer in charge of the de-naturing warehouse shall, in case of the packages of alcohol, inspect same carefully to ascertain whether or not they are the packages described in the distiller's notice. He will then cut out that portion of the warehouse stamp upon which is shown the serial number of the stamp, the name of the distiller, the proof gallons, and the serial number of the package. These slips must be securely fastened to the form whereon the gauging is reported and sent by the officer with his return to the collector." TRANSFER OF DE-NATURANTS TO MIXING TANKS. "SEC. 32. The distiller, unless pipes are used, as herein provided, shall provide suitable gauged receptacles, metal drums being preferred, with which to transfer the de-naturing agents from the material tanks to the mixing tanks. These receptacles must be numbered serially and the number, the capacity in gallons and fractions of a gallon, the name of the distiller, and the number of the de-naturing bonded warehouse marked thereon in durable letters and figures. They shall be used for transferring de-naturing material from the material tanks to the mixing tanks and for no other purpose. The distiller must also provide suitable approved sealed measures of smaller capacity. The gauged receptacles are to be used where the quantity to be transferred amounts to as much as the capacity of the smallest gauged receptacle in the warehouse. The measures are to be used only when the quantity of material to be transferred is less than the capacity of the smallest gauged receptacle. SEC. 33. The distiller may provide metal pipes connecting the material tanks and the mixing tanks and the de-naturant may be transferred to the mixing tanks through these pipes. Such pipes must be supplied with valves, cocks, or faucets, other proper means of controlling the flow of the liquid, and such valves, cocks, or faucets must be so arranged that they can be securely locked, and the locks attached thereto must be kept fastened; the keys to be retained by the officer in charge, except when the de-naturing material is being transferred to the mixing tanks. In the event pipes are used as above provided, the glass gauges affixed to the material tanks must be so graduated that tenths of a gallon will be indicated. Before any material is transferred from a material tank to a mixing tank the officer must note the contents of the material tank as indicated by the glass gauge. He will then permit the de-naturant to flow into the mixing tank until the exact quantity necessary to de-nature the alcohol, as provided by the regulations, has been transferred. This he will ascertain by reading the gauge on the material tank before the liquid has begun to flow and after the flow has been stopped. He should verify the quantity transferred by reading the gauge on the mixing tank before and after the transfer. SEC. 34. The distiller must provide all scales, weighing beams, and other appliances necessary for transferring the de-naturing materials gauging or handling the alcohol, or testing any of the measures, receptacles or gauges used in the warehouse, and also a sufficient number of competent employees for the work." CONTENTS OF MIXING TANK TO BE PLUNGED. "SEC. 35. The exact quantity of distilled spirits contained in the packages covered by the distiller's notice having been ascertained by the officer and the spirits having been dumped into the mixing tank, and the quantities of the several de-naturants prescribed by the regulations having been ascertained by calculation and added as above provided to the alcohol in the mixing tank to be thoroughly and completely plunged and mixed by the distiller or his employees." DRAWING OFF AND GAUGING DE-NATURED PRODUCT. "SEC. 37. The distiller may from time to time as he wishes, in the presence of the officer, draw off from the tank or tanks the de-natured product in quantities of not less than 50 gallons at one time, and the same must at once be gauged, stamped, and branded by the officer and removed from the premises by the distiller." KIND AND CAPACITY OF PACKAGES USED. "SEC. 38. He may use packages of a capacity of not less than five gallons or not more than one hundred and thirty-five (135) gallons, and each package must be filled to its full capacity, such wantage being allowed as may be necessary for expansion. All packages used to contain completely de-natured alcohol must be painted a _light green_, and in no case is a package of any other color to be used." ALCOHOL TO BE IMMEDIATELY DE-NATURED. "SEC. 39. No alcohol withdrawn from distillery warehouse for de-naturing purposes shall be permitted to remain in the de-naturing bonded warehouse until after the close of business on the second day after the said alcohol is withdrawn, but all alcohol so withdrawn must be transferred, dumped, and de-natured before the close of business on said second day." APPLICATION FOR GAUGE OF DE-NATURED ALCOHOL. "SEC. 40. When the process of de-naturing has been completed and the distiller desires to have the de-natured alcohol drawn off into packages and gauged, he shall prepare a request for such gauge on the proper form. The request shall state as accurately as practicable the number of packages to be drawn off and the number of wine and proof gallons contents thereof. This notice shall be directed to the collector of internal revenue, but shall be handed to the officer on duty at the de-naturing bonded warehouse. SEC. 41. If the officer shall find upon examination of the proper record that there should be on hand the quantity of de-natured alcohol covered by said notice, he shall proceed to gauge and stamp the several packages of de-natured alcohol in the manner herein prescribed, and shall make report thereof on the proper form. In no case will the officer gauge and stamp de-natured alcohol the total quantity in wine gallons of which taken together with any remnant that may be left in the de-naturing tank exceeds in wine gallons the sum of the quantity of distilled spirits and de-naturants dumped on that day and any remnant brought over from previous day." HOW DE-NATURED ALCOHOL SHALL BE GAUGED. "SEC. 42. The gauging of de-natured alcohol shall, where it is practicable, be by weight. The officer shall ascertain the tare by actually weighing each package when empty. Then, after each package has been filled in his presence, he shall ascertain the gross weight, and, by applying the tare, the net weight. He shall then ascertain the proof in the usual manner, and by applying the proof to the wine gallons content the proof gallons shall be ascertained. The regulations relating to the gauging of rectified spirits, so far as they apply to apparent proof and apparent proof gallons, shall apply to de-natured spirits. Where it is for any reason not practicable to gauge de-natured alcohol by weight, using the tables that apply in the case of the gauging of distilled spirits, the gauging shall be by rod." Sections 43 to 45 provide for the returns to be made by the Government officials, and the proper marking of the packages containing de-natured alcohol; and Sections 46 to 48 lay down the form of the Government stamps and their use. Section 49 places the mixing tank absolutely in the control of the warehouse officer, and requires if he leaves the warehouse he must close and lock the same. Section 50 deals with records to be kept by warehouse officer. DE-NATURED ALCOHOL TO BE REMOVED FROM WAREHOUSE. "SEC. 51. Not later than the close of business on the day following that upon which the work of drawing off and gauging the de-natured spirits is completed, the distiller must remove said de-natured alcohol from the de-naturing bonded warehouse. He may either remove the alcohol to a building off the distillery premises, where he can dispose of it as the demands of the trade require, or he may dispose of it in stamped packages direct to the trade from the de-naturing bonded warehouse." Sections 52 and 53 relate to records to be kept by the distiller showing de-natured alcohol received and disposed of by him, and the parties to whom the same was sold or delivered. Sections 54 to 57 cover reports and records to be made by officers and collector. Part II of the Regulations relates to dealers in de-natured alcohol, and manufacturers using the same. "SEC. 58. Alcohol de-natured by use of methyl alcohol and benzine as provided in section 26 of these regulations is to be classed as _completely de-natured alcohol_. Alcohol de-natured in any other manner will be classed as _specially de-natured alcohol_." DE-NATURED ALCOHOL NOT TO BE STORED ON CERTAIN PREMISES, AND NOT TO BE USED FOR CERTAIN PURPOSES. "SEC. 59. Neither completely nor specially de-natured alcohol shall be kept or stored on the premises of the following classes of persons, to wit: dealers in wines, fermented liquors or distilled spirits, rectifiers of spirits, manufacturers of and dealers in beverages of any kind, manufacturers of liquid medicinal preparations, or distillers (except as to such de-natured alcohol in stamped packages as is manufactured by themselves), manufacturers of vinegar by the vaporizing process and the use of a still and mash, wort, or wash, and persons who, in the course of business, have or keep distilled spirits, wines, or malt liquors, or other beverages stored on their premises. _Provided_, That druggists are exempt from the above provisions." CAN NOT BE USED IN MANUFACTURING BEVERAGES, ETC. "SEC. 60. Anyone using de-natured alcohol for the manufacture of any beverage or liquid medicinal preparation, or who knowingly sells any beverage or liquid medicinal preparation made in whole or in part from such alcohol, becomes subject to the penalties prescribed in section 2 of the Act of June 7, 1906." Under the language of this law it is held that de-natured alcohol can not be used in the preparation of any article to be used as a component part in the preparation of any beverage or liquid medicinal preparation. A person, firm, or corporation desiring to sell de-natured alcohol, must make application, in proper form, to the district collector on or before the first of July each year, and if the provisions of the law have been violated the permit may be withdrawn (Sections 61 to 65). Sections 66 to 71 relate to the keeping of records by collector, and wholesale and retail dealers. RETAIL DEALERS TO KEEP RECORD. "SEC. 72. Retail dealers in de-natured alcohol shall keep a record, in which they shall enter the date upon which they receive any package or packages of de-natured alcohol, the person from whom received, the serial numbers of the packages, the serial numbers of the de-natured alcohol stamps the wine and proof gallons, and the date upon which packages are opened for retail. The transcript for each month's business as shown by this record must be prepared, signed, and sworn to and forwarded to the collector of internal revenue of the district in which the dealer is located before the 10th of the following month. This transcript must be signed and sworn to by the dealer himself or by his duly authorized agent." LABELS TO BE PLACED ON RETAIL PACKAGES. "SEC. 73. Retail dealers in de-natured alcohol must provide themselves with labels upon which the words "De-Natured Alcohol" have been printed in plain, legible letters. The printing shall be red on white. A label of this character must be affixed by the dealer to the container, whatever it may be, in the case of each sale of de-natured alcohol made by him." STAMPS TO BE DESTROYED WHEN PACKAGE IS EMPTY. "SEC. 74. As soon as the stamped packages of de-natured alcohol are empty the dealer or manufacturer, as the case may be, must thoroughly obliterate and completely destroy all marks, stamps, and brands on the packages. The stamps shall under no circumstances be re-used, and the packages shall not be refilled until _all_ the marks, stamps, and brands shall have been removed and destroyed." MANUFACTURERS USING COMPLETELY DE-NATURED ALCOHOL TO SECURE PERMIT. "SEC. 75. Manufacturers desiring to use completely de-natured alcohol, such as is put upon the market for sale generally, may use such alcohol in their business subject to the following restrictions: A manufacturer using less than an average of 50 gallons of de-natured alcohol per month will not be required to secure permit from the collector or to keep records or make returns showing the alcohol received and used. Manufacturers who use as much as 50 gallons of completely de-natured alcohol a month must procure such alcohol in stamped packages, and before beginning business the manufacturer must make application to the collector of the proper district for permit, in which application he will state the exact location of his place of business, describing the lot or tract of land upon which the plant is located, and must keep the alcohol in a locked room until used. "SEC. 79. As the agents adapted to and adopted for use in complete de-naturation render the alcohol de-natured unfit for use in many industries in which ethyl alcohol, withdrawn free of tax, can be profitably employed, therefore in order to give full scope to the operation of the law, special de-naturants will be authorized when absolutely necessary. Yet the strictest surveillance must be exercised in the handling of alcohol incompletely or specially de-natured." FORMULA FOR SPECIAL DE-NATURANTS TO BE SUBMITTED TO THE COMMISSIONER. "SEC. 80. The Commissioner of Internal Revenue will consider any formula for special de-naturation that may be submitted by any manufacturer in any art or industry and will determine (1) whether or not the manufacture in which it is proposed to use the alcohol belongs to a class in which tax-free alcohol withdrawn under the provisions of this act can be used. (2) whether or not it is practicable to permit the use of the proposed de-naturant and at the same time properly safeguard the revenue. But one special de-naturant will be authorized for the same class of industries, unless it shall be shown that there is good reason for additional special de-naturants." The Commissioner will announce from time to time the formulas of de-naturants that will be permitted in the several classes of industries in which tax-free alcohol can be used. The specially or incompletely de-natured alcohol can only be used by special permission, for which the manufacturer must apply, at the same time giving full details as to business, plant, premises, the special de-naturants desired to be used, and the reason therefor, etc. (Section 81). Section 82 recites the necessary requirements as to storerooms, etc., and Sections 83 to 87 relate to the form of application and the inspection of the plant. Section 88 recites the form of bond necessary to be given by the manufacturer, and Sections 89 to 104 relate to the general requirements as to records, books, affidavits, etc. Sections 105 and 106 rule that the alcohol must be used just as received, and as called for in the permit, and that a manufacturer quitting business may dispose of his specially de-natured alcohol to other manufacturers. PROVISIONS APPLICABLE TO MANUFACTURERS USING EITHER SPECIALLY OR GENERALLY DE-NATURED ALCOHOL. "SEC. 107. Under no circumstances will de-naturers, manufacturers, or dealers, or any other persons, in any manner treat either specially or completely de-natured alcohol by adding anything to it or taking anything from it until it is ready for the use for which it is to be employed. It must go into manufacture or consumption in exactly the same condition that it was when it left the de-naturer. Diluting completely de-natured alcohol will be held to be such manipulation as is forbidden by law. "SEC. 108. Manufacturers using either specially or completely de-natured alcohol must store it in the storeroom set apart for that purpose, the place for deposit named in the bond and application, and nowhere else. Likewise they must deposit recovered alcohol in said storeroom as fast as it is recovered. It will be held to be a breach of the bond and a violation of the law if any alcohol of any kind, character, or description should be found stored at any other place on the premises." The question of special de-naturants is one of great importance to the manufacturer, and should be carefully studied. The distiller who succeeds on a large scale will be he who is most expert in preparing alcohol specially de-natured to suit the requirements of the various arts. Germany has done most in this line, and the German practice should be carefully studied. Parts IV and V of the Rules relate to that portion of the De-Naturing Act, referred to in Section 2 thereof--the recovering, restoring and re-de-naturing of alcohol used by manufacturers employing processes in which the formerly de-natured spirits are? expressed, or evaporated. This not being within the plan of this book, the rules relating thereto are not quoted. Those desirous of acquiring full information as to the rules regulating the operation of distilleries for the manufacture of alcohol and de-natured spirits can procure the same by applying either to the collectors of Internal Revenue for their respective districts or to the Commissioner of Internal Revenue, Washington, D. C. PROPOSED CHANGES IN THE DE-NATURING ACT. The De-naturing Act as passed and the regulations thereunder are undoubtedly too complicated in their character to remain very long in the Statute Books. There has already arisen a cry for simpler regulations which shall place the manufacture of de-natured alcohol on a plane with the practice in Germany, France and other countries which have carried the manufacture and use of alcohol, for industrial purposes to a very high plane. Both in England and America the Excise and Internal Revenue regulations have been of very troublesome character, and the production of spirits has been so carefully guarded, watched and checked that the distiller aside from the high tax he has had to pay has been greatly hampered. In Germany and France, however, things are different. There the manufacture of Industrial Alcohol from farm products has been encouraged and as a consequence the regulations are of very much simpler character. In Germany the number of agricultural or co-operative stills is very large and these stills are practically free from the constant supervision of internal revenue officials. Until the wash passes into the still there is practically no Governmental supervision except as to the proper gauging of the vats and to the proper sealing of all joints or pipes leading from the vats to the still. From that point onward, however, to the final receiver every vessel is locked and sealed and no access to the spirit can be obtained by the distiller. The quantity of spirit distilled and its quality is ascertained by the Revenue Officer from this final receiver and on this spirit so found is computed the vat tax and the distillery tax which have to be paid by the distiller. There are none of the cumbersome regulations regarding the warehouses, storehouses, storekeepers, etc., which are found in our own revenue laws. To provide security against abstraction of wash in the fermenting tanks, reliance is placed upon frequent but uncertain visitations. There is no question but that in the fulness of time our own laws and regulations will be very much simplified for all industrial plants. An attempt has been made to so simplify the laws by Act of Congress No. 230, approved March 2, 1907 and taking effect on September 1, 1907, the text of which is appended, and undoubtedly other acts will follow as the country becomes more and more sensible of the benefits to be derived from free industrial alcohol. The text of the act is as follows: [PUBLIC--NO. 230.] An Act to amend an Act entitled "An Act for the withdrawal from bond tax free of domestic alcohol when rendered unfit for beverage or liquid medicinal uses by mixture with suitable denaturing materials," approved June seventh, nineteen hundred and six. _Be it enacted by the Senate and House of Representatives of the United States of America in Congress Assembled_, That notwithstanding anything contained in the Act entitled "An Act for the withdrawal from bond tax free of domestic alcohol when rendered unfit for beverage or liquid medicinal uses by mixture with suitable de-naturing materials," approved June seventh, nineteen hundred and six, domestic alcohol when suitably denatured may be withdrawn from bond without the payment of internal-revenue tax and used in the manufacture of ether and chloroform and other definite chemical substances where said alcohol is changed into some other chemical substance and does not appear in the finished product as alcohol: _Provided_, That rum of not less than one hundred and fifty degrees proof, may be withdrawn, for de-naturation only, in accordance with the provisions of said Act of June seventh, nineteen hundred and six, and in accordance with the provisions of this Act. SEC. 2. That the Commissioner of Internal Revenue, with the approval of the Secretary of the Treasury, may authorize the establishment of central de-naturing bonded warehouses, other than those at distilleries, to which alcohol of the required proof may be transferred from distilleries or distillery bonded warehouses without the payment of internal-revenue tax, and in which such alcohol may be stored and de-natured. The establishment, operation, and custody of such warehouses shall be under such regulations and upon the execution of such bonds as the Commissioner of Internal Revenue, with the approval of the Secretary of the Treasury, may prescribe. SEC. 3. That alcohol of the required proof may be drawn off, for de-naturation only, from receiving cisterns in the cistern room of any distillery for transfer by pipes direct to any de-naturing bonded warehouse on the distillery premises or to closed metal storage tanks situated in the distillery bonded warehouse, or from such storage tanks to any denaturing bonded warehouse on the distillery premises, and de-natured alcohol may also be transported from the de-naturing bonded warehouse, in such manner and by means of such packages, tanks or tank cars, and on the execution of such bonds, and under such regulations as the Commissioner of Internal Revenue, with the approval of the Secretary of the Treasury, may prescribe. And further, alcohol to be de-natured may be withdrawn without the payment of internal-revenue tax from the distillery bonded warehouse for shipment to central de-naturing plants in such packages, tanks and tank cars, under such regulations, and on the execution of such bonds as may be prescribed by the Commissioner of Internal Revenue, with the approval of the Secretary of the Treasury. SEC. 4. That at distilleries producing alcohol from any substance what ever, for de-naturation only, and having a daily spirit-producing capacity of not exceeding one hundred proof gallons, the use of cisterns or tanks of such size and construction as may be deemed expedient may be permitted in lieu of distillery bonded warehouses, and the production, storage, the manner and process of de-naturing on the distillery premises the alcohol produced, and transportation of such alcohol, and the operation of such distilleries shall be upon the execution of such bonds and under such regulations as the Commissioner of Internal Revenue, with the approval of the Secretary of the Treasury, may prescribe, and such distilleries may by such regulations be exempted from such provisions of the existing laws relating to distilleries as may be deemed expedient by said officials. SEC. 5. That the provisions of this Act shall take effect on September first, nineteen hundred and seven. Approved, March 2, 1907. INDEX. Adam's Still, 38 faults of, 39 operation of, 38 Air necessary to fermentation, 18 cooling for mashes, 15 Alcohol, absolute, 2 as fuel, 221 boiling point of, 2 points of mixture, 2 composition of, 1, 6 contraction in mixtures of, 4 de-natured, 143 determination of purity, 186, 188 estimation of, 179 estimating by Geisler's method, 183 Brand's method, 184 sugar in "Beer", 185 ethyl, 7 methyl, 7 measuring in mixtures, 174, 179 by hydrometers, 176, 178 proof, 175 rectification of, 82, 92 relative amounts in different grains, 126 specific gravity of, 2, 174 strengthening, 31 under proof, 176 wood, 7 Alcoholometer, Cartier's, 178 Field's, 182 Tralle's, 179 Alcoholometry, 174 Alcohols, principal, 6 boiling points of principal, 6 composition of principal, 6 Barbet's still, 93 traps, 68 test for alcoholic purity, 187 Barley best for malting, 103 cleaning, 104 draining after steeping, 105 drying malt from, 108 effect of germination on, 107 germination of, 106 steeping, 105 test of sufficient steeping, 105 washing, 104 Beet-cleaners, 151 -juice, extraction of by maceration and diffusion, 157, 158 pulp, addition of sulphuric acid to, 153, 156, 160 presses, 154, 156 rasp, 152 Beets, alcohol from, 150 cellars for storing, 149 cultivation of, 140 characteristics of good, 140 cleaning, 151 composition of, 141 conditions for cultivating, 142, 144, 145 diffusion battery for, 158 direct distillation of, 161 distilling apparatus for, 162, 200, 201 distilling plant for, 199, 201 Beets, fermenting juice of, 160 harvesting, 146 how to tell when ripe, 147 hydraulic presses for, 153 macerating, 156, 159 manures for, 143 roll press for, 154 soil for growing, 142 sowing, 144, 146 stack for storing, 148 storing in winter, 149 scum forming during fermentation of, 160 transportation of, 203 Boiling over, to prevent in still, 58 points of alcoholic liquors, 2 Carbonic anhydride, to get rid of, 25 Cellar for beets, 149 Cellier-Blumenthal still, 48 Cleaning barley, 103 beets, 150 grain, 104 potatoes, 110, 204 apparatus for, 151 Coal consumption, 208 Coffey's still, 54 Column distillery, 64, 66 rectifying, 51, 87, 94 Condenser, Cellier-Blumenthal's, 48 Coffey's still, 54 and mash heater, 41, 43, 46, 52, 64, 74 Concentration of alcohol by distillation, 31 Continuous distillation, 50 Cooling mashes by air, 15 by water, 17, 133, 196 Corn, mashing, (see Grain). Couch, wet, 106 Covered fermentation, 27 Current still, 59 De-Naturants, formulas for, 211, 214, 216, 219, 254 prescribed in U. S., 211, 220 De-natured alcohol in Canada, 214 England, 214 France, 215 Germany, 211, 214 uses of, 210, 213, 217 in Germany, 217, 222 De-naturing in London establishment, 215 in U. S., Acts regulating, 212, 219, 225, 259 regulations, 229 with benzine, 216 Diastase, 14 proper temperature for action of, 14, 133 Distilling apparatus, 33, 63, 189 Adams', 8 beet, 162 Cellier-Blumenthal's, 48 Coffey's, 54 continuous, 50, 68 current, 59 compound still, 46, 47 fire heated, 47 Corty's, 40 double, 41 Dorn's, 43 Gillaume's, 78 simple, 38, 36, 190 with enricher, 37 Distilling column, 64, 73 plants, 189, 199, 205 Distillation, checking 32 compound, 42, 50 multiple to strengthen alcohol, 31 Dough, luting still with, 34 Dujardin's roll press for beets, 154 Drying, barley, 108 kiln for, 108 Drying rooms, temperature of, 108 Dunder from molasses, 168 Flavor in alcohol, cause of bad, 86 Ferment, too much, 24 Fermentation in general, 9, 18, 27 alcoholic, 22, 23 acetous, 24 foaming, 27 heat necessary for, 19 lactic, 25 loss in, 28 phenomena of, 27 periods of, 26 under cover, 27 viscous, 25 Fermenting apparatus, 28, 194 room, 29, 194 vats, 28, 29, 195 Fire, regulating distilling, 61 Floors for malting barley, 106 "Fractionating", 83 Fusel oil, (see Rectifying). Geisler's apparatus for estimating alcohol, 184 Gelatinizing apparatus, 10 Germinating barley, 106 Grain, alcohol from, 126 composition of, 128 cooling of mashed, 133 distillery for, 197 grinding, 129 infusion of, 131, 135 Grain, mashing in general, 130, 134 mashing, proportions of grain for, 134 under steam pressure, 137 mashes, cooling, 133 regulating temperature of, 133, 138 mash tub, 134 thin mash of, 134, 135 saccharifying, 131, 134 steeping, 129 sulphurous acid, 132 temperature of water, 129 sufficient steeping of, 130 Grains, relative quantities of alcohol from various, 126 Gauge glass, 71 Heat indicator for regulating, 61 necessary for fermentation, 19 Henze steamer, 11, 14 Hydraulic presses for beets, 153 Hydrometers, 176, 177 Indicator for regulating distillery fire, 61 Iodine Test, 185 Lactic fermentation, 25 Lime, neutralizing acid by milk of, 80 Loss of alcohol in fermentation, 28 Malt, 103 drying, 108 grinding dried, 109 kiln, 108 Malting barley, 103 cleaning barley for, 104 couch, 106 floors, 106 germinating barley for, 106 in large plants, 108 steeping barley for, 105 Mash cooling, 15, 16, 17 heating, 52, 74 tub, 122, 123, 124 Mashing in general, 8 grain, 30, 134 cleaning, 104 potatoes, 110, 125 starchy materials, 10 Molasses, alcohol from, 163 acidifying, 164 beet sugar, 164 cane sugar, 168 clarifying cane sugar, 170 composition of " ", 168 dilution of, 167 dunder from cane sugar, 168 fermenting cane sugar, 170, 206 cane sugar in Mauritius, 172 cane sugar in Java, 172 mixing vats for water and, 164, 165 plant for distilling, 205 skimmings from cane sugar, 168 transportation of, 207 washes, setting up, 166 pitching temperature of, 166 Methylated spirits, 211, 212 Neutralizing Acids in rectifying, 86 Pitching the mash, 22 temperature, 22 Potato-alcohol use in Germany, 212 how to obtain good, 138 Potatoes, alcohol from, 110 best for distilling, 110 cleaning, 110, 204 crusher for, 116 Potatoes, crushing and steaming, 111, 117 extraction of starch from separately, 122 isolation of starch from, 122 keeping, 110 mashing, 110, 118, 125 plant for distilling, 204 rasp for pulping, 152 saccharifying by sulphuric acid, 124 starch from, 122 steaming, 111 under high pressure, 11, 118, 121 vat for, 112, 121 steamer and crusher for, 111, 117 vacuum cooker for, 11 "Proof spirit", 175 Rectification, 82, 92 by filtration, 101 Rectifying apparatus, 87 Barbet's, 94 Gillaume, 97, 99 intermittent, 90 Vulcan, 93 Regulating distillery fire, 61 Relative quantities of alcohol in grains, 126 Rice, (see Grains). Saccharification, 8, 10, 14 by sulphuric acid, 138 complete, 185 of grain, signs of, 137 Saccharifying apparatus, 14 Specific gravity of alcohol, 2, 174 calculating, 174 Steam generator, 114 regulator, 69 Steamers, high pressure, 11, 12 Steaming under high pressure, 13 Steaming grain, 136 potatoes, 111 under pressure, 118, 121 vat, 112 Steeping barley, 105 grain, 129 sufficiently, 130 temperature, 130 Stills, (see Distilling Apparatus). Sulphuric acid for saccharifying grain, 138 neutralizing, 86 Sykes' hydrometer, 177 Testing Alcohol for purity, 187 Twin column rectifier, 95 Vacuum cooker, 10, 11 Vulcan rectifying still, 93 stills, 73, 77 traps, 75 Water for distilling, 208 Yeast, 20 brewers, 11 fermentation by, 9, 10 * * * * * ELECTRICAL BOOKS. =THE DISEASES OF ELECTRICAL MACHINERY.= By ERNST SCHULZ. Edited with a preface by Sylvanus P. Thompson. Contents of Chapters: 1, _Continuous Current Machines_; breakdowns in the armature; brushes and brush holders; faults in the field winding; faults in the regulator or starter. 2, _Singlephase and Polyphase Generators_; faults in armature; grounds in generators; connections of different phases; field windings. 3, _Singlephase and Polyphase Induction Motors_; stator faults; rotor faults. 4, _Transformers_; faults in winding; effects of lightning. 5, _Efficiency_; examples of efficiency calculations. 94 pages, 42 illustrations, 12mo., cloth, $1.00. =ELECTRICAL TABLES AND MEMORANDA.= A valuable little reference book for engineers, electricians, motor inspectors and others interested in the electrical science, containing many tables and much valuable information in a very small space, with a number of illustrations, by PROF. SILVANUS THOMPSON. 64mo., roan, gilt edges, 40c. =THE VOLTAIC ACCUMULATOR.= By EMILE REYNIER. Contents: Part 1, Principles, definitions, voltmeters. Part 2, Voltaic accumulators of various types. Part 3, Technology. Part 4, Application of accumulators. 202 pages, 62 illustrations, cloth, $3.00. =THE MERCURIAL AIR PUMP.= By PROF. SILVANUS P. THOMPSON, D. Sc. 37 pages, 43 illustrations, large 8vo., paper, 60c.[++] =THERMO-ELECTRIC REACTIONS AND CURRENTS, BETWEEN METALS IN FUSED SALTS.= By THOMAS ANDREWS, F.R.S. 18 pages, with illustrations and tables, 8vo., paper, 40c.[++] =THE APPLICATION OF ELECTRICITY TO RAILWAY WORKING.= By WILLIAM EDWARD LANGDON. Contents of Chapters: 1, On the construction of a telegraph line. 2, Surveying. 3, Construction. 4, Telegraph instruments and batteries. 5, Block signalling. 6, Single line working. 7, Automatic block signalling. 8, Interlocking. 9, Miscellaneous appliances in connection with block signalling. 10, Train lighting. 11, Electric light and power. 12, Intercommunication in trains. 13, Administration. Appendix. Index. 301 pages, 6 full page plates and 143 engravings and diagrams, 8vo., cloth, $5.00. =ELECTRICAL TESTING OF TELEGRAPH CABLES.= By COL. V. HOSKIAER. Third edition. 12mo., cloth, $1.50. =HARD SOLDERING, A MANUAL OF INSTRUCTION IN.= By H. ROWELL, with a chapter on soft soldering and brazing. 12mo., cloth, 75c. * * * * * JUST OUT. 293 pages, 298 illustrations, 8vo. Cloth, $1.00 net. THE MODEL LIBRARY VOL. I. Consisting of the following four American books, with very complete general index. =The Study of Electricity= and Its Laws for Beginners. =How to Install Electric Bells=, Annunciators and Alarms. =Dry Batteries=, How to Make and Use Them. =Electrical Circuits= and Diagrams. Illustrated and explained. * * * * * 25c. BOOKS. =ELECTRICITY.= The study of, and its laws for beginners, comprising the laws of electric current generation and flow, Ohm's law, galvanism, magnetism, induction, principles of dynamos and motors, wiring, with explanations of simple mathematics as applied to electrical calculations. By N. H. SCHNEIDER. With 55 original illustrations and 6 tables. =DRY BATTERIES.= A practical handbook on the designing, filling and finishing of dry batteries, with tables, for automobiles, gas engine, medical and coil work, electric bells, alarms, telephones, experiments and all purposes requiring a first-rate battery. Fully illustrated with 30 original drawings. =ELECTRICAL CIRCUITS AND DIAGRAMS.= Being a selection of original up-to-date and practical diagrams for installing annunciators, alarms, bells, electric gas lighting, telephones, electric power light and wiring circuits, induction coils, gas engine igniters, dynamos and motors, armature windings. By N. H. SCHNEIDER. =ELECTRIC BELLS AND ALARMS.= How to install them. By N. H. SCHNEIDER. Including batteries, wire and wiring, circuits, pushes, bells, burglar alarms, high and low water alarms, fire alarms, thermostats, annunciators, and the locating and remedying of faults. With 56 original diagrams. =MODERN PRIMARY BATTERIES.= Their construction, use and maintenance, including batteries for telephones, telegraphs, motors, electric lights, induction coils, and for all experimental work. By N. H. SCHNEIDER. 94 pages, 55 illustrations. The best and latest American book on the subject. =EXPERIMENTING WITH INDUCTION COILS.= H. S. NORRIE, author of "Induction Coils and Coil Making." A most instructive little book, full of practical and interesting experiments, fully explained in plain language with numerous hints and suggestions for evening entertainments. Arranged under the following headings: Introduction; The Handling of Ruhmkorff Coil; Experiments with Sparks; Effects in the Vacuum; Induction and Wireless Telegraphy. With 36 original illustrations. [In the press] =SMALL ACCUMULATORS.= How made and used, by P. MARSHALL. Giving full descriptions how to make all the parts; assemble them, charge the cells and run them, with examples of their practical application. Useful receipts and memoranda and a glossary of technical terms. 80 pages, 40 illustrations, paper. = ELECTRIC GAS LIGHTING.= How to install Electric gas igniting apparatus including the jump spark and multiple systems for all purposes. Also the care and selection of suitable batteries, wiring and repairs, by H. S. NORRIE. 101 pages, 57 illustrations, paper. =SIMPLE ELECTRICAL WORKING MODELS.= How to make them and how to use them. With 43 illustrations. =TELEPHONES AND MICROPHONES.= Making and using simple forms of telephones and microphones, with 29 illustrations. =SMALL ELECTRIC MOTORS.= How to make and use them, including design, examples of small motors, and their applications, speed controllers, starters, fuses, etc. 48 illustrations. =ELECTRIC LIGHTING= for amateurs. The installation of electric light on a small scale, construction of lamps and lamp holders, switches, batteries and their connections. With 45 illustrations. =INDUCTION COILS.= A practical handbook on the construction and use of shock and spark coils. With 35 illustrations. =X-RAYS SIMPLY EXPLAINED.= The theory and practical application of Radiography. 10 illustrations and 6 plates. =STATIC ELECTRICITY.= Simple experiments in. A series of instructive and entertaining electrical experiments with simple and inexpensive apparatus. With 51 illustrations. =SIMPLE SCIENTIFIC EXPERIMENTS.= How to perform entertaining and instructive experiments with simple home-made apparatus. With 59 Illustrations. =SMALL ELECTRICAL MEASURING INSTRUMENTS=, describing the making and using of the different instruments fully illustrated. =SMALL DYNAMOS AND MOTORS.= How to make and use them. A practical handbook, by F. E. POWELL. Contents of Chapters: 1. General Considerations. 2. Field Magnets. 3. Armatures. 4. Commutators and Other Details. 5. Tables of Windings. 6. How to Build a Small Machine. 7. Useful Data. 8. Testing and Repairing. 76 pages, fully illustrated with detail drawings. =UNIVERSAL TIME CARD MODEL.= By setting to the desired hour at any one place the movable model will show at a glance the actual time of all the other places in the world. Printed in two colors. CROSS SECTION BOOKS 25c. each. =THE HANDY SKETCHING BOOK.= Size 5×8, scale 8 to 1 in. =THE HANDY SKETCHING PAD.= Size 8×10, scale 8 to 1 in. =ELECTRICIANS' SKETCHING BOOK.= Size 5×8, scale 10 to 1 in. =ELECTRICIANS' SKETCHING PAD.= Size 8×10, scale 10 to 1 in. =PLOTTING PAD.= Size 9×11, scale 16 to 1 in. * * * * * =ELECTRICAL INSTRUMENTS and TESTING.= How to Use the Voltmeter, Ammeter, Galvanometer, Potentiometer, Ohmmeter, the Wheatstone Bridge, and the Standard Portable Testing Sets. BY NORMAN H. SCHNEIDER. Author of "Care and Handling of Electric Plants," "Induction Coils and Coil Making," "Circuits and Diagrams," etc., etc. The aim of the author has been to produce a complete and practical work on this important subject. First describing the various forms of Electrical Testing and Measuring Instruments and their construction. Secondly, their practical application to everyday work with numerous examples worked out. Thirdly, detailing the many tests of insulation resistance, current and e.m.f. that can be made with a voltmeter. Using only formulas in simple algebra and then explaining them in plain language for the benefit of practical men lacking a knowledge of mathematics. During the past ten years the author has made hundreds of tests, which has made him familiar with the subject from the practical standpoint. He has also obtained valuable information and diagrams from the principal manufacturers of Testing Instruments. The apparatus described is modern and in universal use. Most of the diagrams have been specially drawn for this book. The work is divided into XI. chapters as follows: Introduction; Chapters I. and II, The Galvanometer; III, Rheostats; IV, The Voltmeter; V, The Wheatstone Bridge; VI, Forms of Portable Sets; VII, Current Flow and e.m.f.; VIII, The Potentiometer; IX, Condensers; X, Cable Testing; XI, Testing with Voltmeter. =230 pages, 105 illustrations and diagrams, 12mo., cloth, $1.00.= * * * * * EVERYBODY'S BOOK ON ELECTRICITY. PRACTICAL ELECTRICS. A UNIVERSAL HANDY-BOOK ON EVERYDAY ELECTRICAL MATTERS. FIFTH EDITION. CONTENTS. _Alarms._--Doors and Windows; Cisterns, Low Water in Boilers; Time Signals; Clocks. _Batteries._--Making; Cells; Bichromate; Bunsen; Callan's; Copper-oxide; Cruikshank's; Daniel's; Granule carbon; Groves; Insulite; Leclanché; Lime Chromate; Silver Chloride; Smee; Thermo-electric. _Bells._--Annunciator System; Double System; and Telephone; Making; Magnet for; Bobbins or Coils; Trembling; Single Stroke; Continuous Ringing. _Connections. Carbons. Coils._--Induction; Primary; Secondary; Contact-breakers; Resistance. Intensity Coils.--Reel; Primary; Secondary; Core; Contact-breaker; Condenser; Pedestal; Commutator; Connections. _Dynamo-Electric Machines._--Relation of Speed to Power; Field-Magnets; Pole-pieces; Field-magnet Coils; Armature Cores and Coils; Commutator Collectors and Brushes; Relation of size to efficiency; Methods of exciting Field-Magnets; Magneto-Dynamos; Separately excited Dynamos; Shunt Dynamos; Organs of Dynamos as constructed in practice; Field-Magnets; Armatures; Collectors; Brush Dynamo; Second Class; Alternate Currents; Third Class. _Fire Risks._--The Dynamo; Wires; Lamps; Danger to persons. _Measuring._--Non-Registering Instruments; Registering Instruments. _Microphones._--Construction, &c. _Motors._--Application; for Railways. _Phonographs. Photophones. Storage._--Plates. _Terminals._--Charging. _Telephones._--Forms; Circuits and Calls; Transmitter and Switch; Switch for Simplex. 135 PAGES. 126 ILLUSTRATIONS. 8 VO. Cloth, 75 Cents. * * * * * AN AMERICAN BOOK. INDUCTION COILS and COIL MAKING. Second edition thoroughly revised, greatly enlarged and brought up to latest American Practice, BY H. S. NORRIE, (NORMAN H. SCHNEIDER) Considerable space in the new matter is given to the following: Medical and bath coils, gas engine and spark coils, contact breakers, primary and secondary batteries; electric gas lighting; new method of X-ray work, etc. A complete chapter on up-to-date wireless telegraphy; a number of new tables and 25 original illustrations. Great care has been given to the revision to make this book the best American work on the subject. A very complete index, contents, list of illustrations and contents of tables have been added. Contents of Chapters. 1. Construction of coils; sizes of wire; winding; testing; insulation; general remarks; medical and spark coils. 2. Contact breakers. 3. Insulation and cements. 4. Construction of condensers. 5. Experiments. 6. Spectrum analysis. 7. Currents in vacuo; air pumps. 8. Rotating effects. 9. Electric gas lighting; in multiple; in series. 10. Primary batteries for coils; varieties; open circuit cells; closed circuit cells; solutions. 11. Storage or secondary batteries; construction; setting up; charging. 12. Tesla and Hertz effects. 13. Roentgen Radiography. 14. Wireless telegraphy; arrangement of circuits of coil and coherer for sending and receiving messages; coherers; translating devices; air conductors; tables; contents; index. XII + 270 Pages, 79 Illustrations, 5 × 6-1/2 Inches. Cloth. $1.00. * * * * * PRINCIPLES OF ELECTRICAL POWER. (CONTINUOUS CURRENT.) FOR MECHANICAL ENGINEERS. BY A. H. BATE, A.M.I.E.E. The rapid progress that has been made of late years in the application of electricity to industrial purposes, and particularly in the transmission of power by means of the electric motor, has made it imperative for every engineer who wishes to keep up to date to have some knowledge of the way electrical currents are controlled and used for practical purposes. This work is especially written for the practical engineer, mathematics being avoided. Contents of Chapters. 1. The Electric Motor. 2. Magnetic Principles. 3. Electrical Measurements. 4. The Dynamo. 5. Construction of Motor. 6. Governing of Motors. 7. Open and Closed Motors; rating. 8. Motor Starting Switches. 9. Speed Control of Shunt-wound Motors. 10. Series Motor Control. 11. Distribution System. 12. Installing and Connections. 13. Care of Dynamos and Motors. 14. Cost of Plant. 15. Examples of Electric Driving. Horse-power absorbed by various machines, including general engineering and shipyard machines; wood working and printing machinery (arranged in 14 pages of tables). XII + 204 pages, 63 illustrations, 12 mo. cloth. $2.00. * * * * * THE PRACTICAL ENGINEER'S HANDBOOK. TO THE CARE AND MANAGEMENT OF ELECTRIC POWER PLANTS By NORMAN H. SCHNEIDER, _Chief Engineer, "White City," Colingwood, Ohio_. EXTRACTS FROM PREFACE. In revising the first edition of Power Plants the author decided to greatly enlarge it in the hope that it will have a still greater success than the first one. The section on theory is thoroughly revised. A complete chapter on Standard Wiring including new tables and original diagrams added. The National Fire Underwriters' rules condensed and simple explanations given. Direct and alternating current motors have been given a special chapter and modern forms of starting rheostats described at length. The principles of alternators have been considered also transformers and their applications. Modern testing instruments and their use are given a separate chapter. New matter has been added to storage batteries including charging of automobile batteries, 10 new tables, and 137 new illustrations. SYNOPSIS OF CONTENTS OF CHAPTERS. 1. THE ELECTRIC CURRENT; series and multiple connections; resistance of circuits; general explanation of formulas. 2. STANDARD WIRING; wiring formulas and tables; wiring systems; cut-outs; conduits; panel boxes; correct methods of wiring. 3. DIRECT AND ALTERNATING CURRENT GENERATORS; management in the power house; windings; selection of generators. 4. MOTORS AND MOTOR STARTERS; various forms of motors; controllers; care of motors and their diseases; rules for installing. 5. TESTING AND MEASURING INSTRUMENTS; voltmeter testing and connections; instruments used; switchboard instruments. 6. THE STORAGE BATTERY; different kinds; switchboards for charging fixed and movable batteries; management of battery. 7. THE INCANDESCENT LAMP; various methods of testing; life of lamps. 8. ENGINEERING NOTES; belts and pulleys h.p. of belts. Tables. Contents. Index. 290 pages, 203 illustrations. 12mo., cloth, $1.50. Full limp leather, $2.50. * * * * * Design of Dynamos BY SILVANUS P. THOMPSON, D. Sc., B. A., F. R. S. EXTRACTS FROM PREFACE. "The present work is purposely confined to continuous current generators. The calculations and data being expressed in inch measures; but the author has adopted throughout the decimal subdivision of the inch; small lengths being in mils, and small areas of cross-section in sq. mils, or, sometimes, also, in circular mils." CONTENTS OF CHAPTERS. 1. DYNAMO DESIGN AS AN ART. 2. MAGNETIC DATA AND CALCULATIONS. Causes of waste of Power. Coefficients of Dispersion. Calculation of Dispersion. Determination of exciting ampere-turns. Example of Calculation. 3. COPPER CALCULATIONS. Weight of Copper Wire. Electrical resistance of Copper, in cube, strip, rods, etc. Space-factors. Coil Windings; Ends; Insulation; Ventilating; Heating. 4. INSULATING MATERIALS AND THEIR PROPERTIES. A list of materials, including "Armalac," "Vitrite," "Petrifite," "Micanite," "Vulcabeston," "Stabilite," "Megohmite," etc. With tables. 5. ARMATURE WINDING SCHEMES. Lap Windings, Ring Windings, Wave Windings, Series Ring-Windings, Winding Formulæ. Number of circuits. Equalizing connections. COLORED PLATES. 6. ESTIMATION OF LOSSES, HEATING AND PRESSURE-DROP. Copper Losses, Iron Losses, Excitation Losses, Commutator Losses, Losses through sparking. Friction and Windage Losses. Secondary Copper Losses. 7. THE DESIGN OF CONTINUOUS CURRENT DYNAMOS. Working Constants and Trial Values; Flux-densities; Length of Air-gap; Number of Poles; Current Densities; Number of Armature Conductors; Number of Commutator Segments; Size of Armature (Steinmetz coefficient); Assignment of Losses of Energy; Centrifugal Forces; Calculation of Binding Wires; Other procedure in design. Criteria of a good design. Specific utilization of material. 8. EXAMPLES OF DYNAMO DESIGN. 1. Shunt-wound multipolar machine, with slotted drum armature. 2. Over-compounded Multipolar traction generator, with slotted drum armature, with general specifications, tables, dimensions and drawings, fully described. A number of examples of generators are given in each chapter, fully worked out with rules, tables and data. VIII. × 253 pages, 92 illustrations, 10 large folding plates and 4 THREE-COLOR PLATES, 8vo., cloth, $3.50. * * * * * Dynamo-Electric Machinery VOL. I.--CONTINUOUS CURRENT. BY SILVANUS P. THOMPSON, D.Sc., B.A., F.R.S. 7th Edition Revised and Greatly Enlarged. CONTENTS OF CHAPTERS. 1. Introductory. 2. Historical Notes. 3. Physical Theory of Dynamo-Electric Machines. 4. Magnetic Principles; and the Magnetic Properties of Iron. 5. Forms of Field-Magnets. 6. Magnetic Calculations as Applied to Dynamo Machines. 7. Copper Calculations; Coil Windings. 8. Insulating Materials and their Properties. 9. Actions and Reactions in the Armature. 10. Commutation; Conditions of Suppression of Sparking. 11. Elementary Theory of the Dynamo, Magneto and Separately Excited Machines, Self-exciting Machines. 12. Characteristic Curves. 13. The Theory of Armature Winding. 14. Armature Construction. 15. Mechanical Points in Design and Construction. 16. Commutators, Brushes and Brush-Holders. 17. Losses, Heating and Pressure-Drop. 18. The Design of Continuous Current Dynamos. 19. Analysis of Dynamo Design. 20. Examples of Modern Dynamos (Lighting and Traction). 21. Dynamos for Electro-Metallurgy and Electro-Plating. 22. Arc-Lighting Dynamos and Rectifiers. 23. Special Types of Dynamos; Extra High Voltage Machines, Steam-Turbine Machines, Extra Low Speed Machines, Exciters, Double-Current Machines, Three-Wire Machines, Homopolar (Unipolar) Machines, Disk Dynamos. 24. Motor-Generators and Boosters. 25. Continuous-Current Motors. 26. Regulators, Rheostats, Controllers and Starter. 27. Management and Testing of Dynamos. Appendix, Wire Gauge Tables. Index. 996 pages, 573 illustrations, 4 colored plates, 32 large folding plates. 8vo., cloth. $7.50.[++] * * * * * Alternating-Current Machinery BEING VOL. II OF Dynamo-Electric Machinery. BY SILVANUS P. THOMPSON, D.Sc., B.A., F.R.S. Owing to the enormous increase in the use of electrical machinery since the publication of the sixth edition of DYNAMO-ELECTRIC MACHINERY the author has deemed it advisable to divide the work. Vol. I. is devoted to DIRECT CURRENT MACHINERY and this the second part. Vol. II. ALTERNATING CURRENT MACHINERY. Amongst the many new features treated special mention must be made of the number of fine colored plates of windings and the many large folding scale drawings. These two volumes make the most comprehensive and authoritative work on dynamo machinery. The work has been so universally adopted that it has been found necessary to translate it into French and German. CONTENTS OF CHAPTERS. 1. Principles of Alternating Currents. 2. Periodic Functions. 3. Alternators. 4. Induced E.M.F. and Wave-Forms of Alternators. 5. Magnetic Leakage and Armature Reaction. 6. Winding Schemes for Alternators. 7. Design of Alternators. Compounding of Alternators. 8. Examples of Modern Alternators. 9. Steam Turbine Alternators. 10. Synchronous Motors, Motor Generators, Converters. 11. Parallel Running of Alternators. 12. Transformers. 13. Design of Transformers. 14. Induction Motors. 15. Design of Induction Motors. 16. Examples of Induction Motors. 17. Single-Phase Induction Motors. 18. Alternating-Current Commutator Motors. Appendix. The Standardization of Voltages and Frequencies. Complete Index. XX + 848 pages, 546 illustrations, 15 colored plates and 24 large folding plates. 8vo., cloth. $7.50[++]. * * * * * Books for Steam Engineers. =DIAGRAM OF CORLISS ENGINE.= A large engraving giving a longitudinal section of the Corliss engine cylinder, showing relative positions of the piston, steam valves, exhaust valves, and wrist plates when cut-off takes place at 1/4 stroke for each 15 degrees of the circle. With full particulars. Reach-rods and rock shafts. The circle explained. Wrist-plates and eccentrics. Explanation of figures, etc. Printed on heavy paper, size 13 in. × 19 in., =25c.= =THE CORLISS ENGINE= and its Management. A Practical Handbook for young engineers and firemen, (3rd edition) by J. T. HENTHORN. A good little book, containing much useful and practical information. =Illustrated, cloth, $1.00.= =THE FIREMAN'S GUIDE= to the Care and Management of Boilers, by KARL P. DAHLSTROM, M.E., covering the following subjects: Firing and Economy of Fuel; Feed and Water Line: Low Water and Priming: Steam Pressure: Cleaning and Blowing Out; General Directions. A thoroughly practical book. =Cloth, 50c.= =A B C OF THE STEAM ENGINE.= With a description of the automatic shaft governor, with six large scale drawings. A practical handbook for firemen helpers and young engineers, giving a set of detail drawings all numbered and lettered and with names and particulars of all parts of an up-to-date American high speed stationary steam engine. Also a large drawing and full description of the automatic shaft governor. With notes and practical hints. This work will prove of great help to all young men who wish to obtain their engineer's license. =Cloth, price 50c.= =HOW TO RUN ENGINES AND BOILERS.= By E. P. WATSON, (for many years a practical engineer, and a well-known writer in _The Engineer_.) A first-rate book for beginners, firemen and helpers. Commencing from the beginning, showing how to thoroughly overhaul a plant, foundations, lining up machinery, setting valves, vacuum, eccentrics, connection, bearings, fittings, cleaning boilers, water tube boilers, running a plant, and many useful rules, hints and other practical information; many thousands already sold. =160 pages, fully illustrated, cloth, $1.00.= =AMMONIA REFRIGERATION.= By I. I. REDWOOD. A practical work of reference for engineers and others employed in the management of ice and refrigerating machinery. A first-rate book, beginning from the bottom and going carefully through the various processes, stage by stage, with many tables and original illustrations. =Cloth, $1.00.= =MEYER SLIDE VALVE.= Position diagram of cylinder with cutoff at 1/8, 1/4, 3/8 and 1/2 stroke of piston with movable valves, on card 7-1/2 in. × 5-1/2 in. =Price, 25c.= * * * * * AN ELEMENTARY TEXT-BOOK ON STEAM ENGINES AND BOILERS, FOR THE USE OF STUDENTS IN SCHOOLS AND COLLEGES. BY J. H. KINEALY. _Professor of Mechanical Engineering, Washington University._ Illustrated with Diagrams and Numerous Cuts, Showing American Types and Details of Engines and Boilers. This book is written solely as an elementary text-book for the use of beginners and students in engineering, but more specially for the students in the various universities and colleges in this country. No attempt has been made to tell everything about any one particular subject, but the author has endeavored to give the student an idea of elementary thermodynamics, of the action of the steam in the cylinder of the engine, of the motion of the steam valve, of the differences between the various types of engines and boilers, of the generation of heat by combustion, and the conversion of water into steam. Care has been taken not to touch upon the design and proportion of the various parts of engines and boilers for strength; as, in the opinion of the writer, that should come after a general knowledge of the engine and boiler has been obtained. In the derivation of some of the formulæ in thermodynamics, it has been necessary to use the calculus, but the use of all mathematics higher than algebra and geometry has been avoided as much as possible. An earnest endeavor has been made to present the subject in a clear and concise manner, using as few words as possible and avoiding all padding. CONTENTS OF CHAPTERS. Chapter I.--Thermodynamics; First Law of Thermodynamics; Work, Power; Unit of Heat; Mechanical Equivalent; Application of Heat to Bodies; Second Law of Thermodynamics; Specific Heat; Absolute Temperature; Application of Heat to a Perfect Gas; Isothermal Expansion; Adiabatic Expansion; Fusion; Vaporisation; Application of Heat to Water; Superheated Steam. Chapter II.--Theoretical Heat Engine; Cycle; Thermodynamic Efficiency; Perfect Gas Engine; Perfect Steam Engine; Theoretical Diagram of the Real Engine; Clearance; Efficiency * * * * * THE SLIDE VALVE SIMPLY EXPLAINED. By W. J. TENNANT, Asso. M. Inst. Mech. E. The work has been thoroughly revised and enlarged in accordance with the present American Practice. By J. H. KINEALY, D. E., M. Am. Soc. Mech. E. The work is based upon notes and diagrams which were prepared by Mr. Tennant in his lectures to his classes of working engineers and students towards the obtainment of clear _general_ notions upon the Slide Valve, its design, varieties, adjustments and management. They have been revised and considerably added to and in this form the authors believe they will be of considerable value to all engineers and others interested in steam engines. CONTENTS OF CHAPTERS. I. The Simple Slide. II. The Eccentric a Crank. Special Model to give Quantitative Results. III. Advance of the Eccentric. IV. Dead Centre. Order of Cranks. Cushioning and Lead. V. Expansion--Inside and Outside Lap and Lead; Advance affected thereby. Compression. VI. Double-ported and Piston Valves. VII. The Effect of Alterations to Valve and Eccentric. VIII. Note on Link Motions. IX. Note on very early cut-off, and on Reversing Gears in general. The illustrations aim to cover the different kinds of Slide Valves, and the circular diagrams will prove a novel feature. 88 Pages. 41 Illustrations. 12mo. Cloth, $1.00 * * * * * LUBRICANTS, OILS AND GREASES. TREATED THEORETICALLY AND GIVING PRACTICAL INFORMATION REGARDING THEIR COMPOSITION, USES AND MANUFACTURE. _A PRACTICAL GUIDE FOR MANUFACTURERS, ENGINEERS, AND USERS IN GENERAL OF LUBRICANTS._ By ILTYD I. REDWOOD, Associate Member American Society of Mechanical Engineers; Member Society Chemical Industries (England); Author of 'Theoretical and Practical Ammonia Refrigeration,' and a 'Practical Treatise on Mineral Oils and Their By-Products.' CONTENTS. INTRODUCTION.--Lubricants. THEORETICAL. CHAPTER I.--Mineral Oils: American and Russian; Hydrocarbons. CHAPTER II.</sc>--Fatty Oils: Glycerides; Vegetable Oils; Fish Oils. CHAPTER III.</sc>--Mineral Lubricants: Graphite; Plumbago. CHAPTER IV.</sc>--Greases: Compounded; "Set" or Axle; "Boiled" or Cup. CHAPTER V.</sc>--Tests of Oils: Mineral Oils. Tests of Oils: Fatty Oils MANUFACTURE. CHAPTER VI.--Mineral Oil Lubricants: Compounded Oils; De-bloomed Oils. CHAPTER VII.</sc>--Greases: Compounded Greases; "Set" or Axle Greases; Boiled Greases; Engine Greases. APPENDIX.--The Action of Oils on Various Metals. Index. TABLES: I.--Viscosity and Specific Gravity. II.--Atomic Weights. III.--Origin, Tests, Etc. of Oils. IV.--Action of Oils on Metals. LIST OF PLATES: I.--I. I. Redwood's Improved Set Measuring Apparatus II.--Section Grease Kettle. III.--Diagram of Action of Oils on Metals. 8vo. Cloth. $1.50. * * * * * Mechanical Draft. BY J. H. KINEALY, M. Am. Soc. M.E. _Past President American Society Heating and Ventilating Engineers._ PREFACE. In writing this book the author has assumed that those who will use it are familiar with boilers and engine plants, and he has had in mind the practicing engineer who is called upon to design power plants, and who must therefore decide when it is best to use some form of mechanical draft. The arrangement of the book is what the experience of the author in making calculations for mechanical draft installations has shown him is probably the best. And he has tried to arrange the tables in such a way and in such a sequence that they may prove as useful to others as they have to him. CONTENTS OF CHAPTERS. 1. GENERAL DISCUSSION. Introduction; systems of mechanical draft; chimneys v. mechanical draft; mechanical draft and economizers. 2. FORCED DRAFT. Systems; closed fire-room system; closed ashpit system; small fan required; usual pressure; forced draft and economisers; advantages; disadvantages. 3. INDUCED DRAFT. Introduction; temperature of gases; advantages; disadvantages. 4. FUEL AND AIR. Weight of coal to be burned; evaporation per lb. of coal; effect of rate of evaporation; weight of air required; volume of air and gases; volume of gases to handle; leakage; factor of safety. 5. DRAFT. Relation to rate of combustion; resistance of grate; resistance due to economizer; draft required under different conditions. 6. ECONOMIZERS. Effect of adding; ordinary proportion and cost; increase of temperature of feed water. 7. FANS. Type and proportions of fan used; relation between revolution of fan and draft; capacity of fan. 8. PROPORTIONING THE PARTS. Diameter of fan wheel required; speed at which the fan must run; power required to run the fan; size of engine required; steam used by fan engine; choosing the fan for forced draft, for induced draft without economizer, for induced draft with economizer; location of the fan; breeching and up-take; inlet chamber; discharge chimney; by-pass; water for bearings. Appendix. Tables. Index. 156 pages. 13 plates. 16mo. Cloth, $2.00. * * * * * THE AUTHORITY ON THIS SUBJECT. CENTRIFUGAL FANS. A THEORETICAL AND PRACTICAL TREATISE ON Fans for Moving Air In Large Quantities At Comparatively Low Pressures. BY J. H. KINEALY, M. Am. Soc. M.E. Past-President American Society Heating and Ventilating Engineers. The matter in this book was a series of articles written for the _Engineering Review_. The favorable attention which they attracted lead the author to believe that there was a real demand for a book treating in a theoretical as well as a practical way on centrifugal fans. The articles have been thoroughly revised, added to, and made as complete as possible. Contents of Chapters. 1. Flow of Air; Volume of Air Flowing; Pressure Necessary for required velocity. 2. Vortex; Vortex with Radial Flow. 3. Fans; First Type of Fans; Second or Guibal Type of Fans; Third Type of Fans; Modern Type. 4. Fan Wheel; Vanes or Floats; Inlet; Width. 5. Capacity; Blast Area; Effect of Outlet on Capacity; Air per Revolution. 6. Pressure; Work. 7. Horse Power Required to Run a Fan; Engine Required to Run a Fan; Motor Required to Run a Fan; Width of Belt. 8. Efficiency; Air per Horse Power. 9. Exhausters. 10. Housing; Dimensions of Housings; Shaft. 11. Cone Wheels. 12. Disk Fans; Number of Revolutions per Minute; Capacity of a Disk Fan; Horse Power Required. 13. Choosing a Fan. Index. Twenty-two tables have been prepared and they have been arranged in the way, which the experience of the author in designing heating and ventilating plants has shown to be the most convenient. The tables are full and complete, all calculations having been very carefully checked, read and revised. XIV. + 206 pages, 39 diagrams. Full limp leather pocketbook. =Round Corners, gilt edges. $5.00.[++]= * * * * * CHARTS FOR LOW PRESSURE STEAM HEATING for the use of ENGINEERS, ARCHITECTS, CONTRACTORS AND STEAM FITTERS. By J. H. KINEALY, M.E. _M. Am. Soc. M. E., M. Am. Soc. of H. and V. Eng'rs, &c., &c._ The author has long been in the habit of using charts to aid him in his work. Knowing the value of them in saving time, simplifying work and ensuring correct calculations he feels confident that they will be appreciated by engineers, architects and contractors, for whose benefit they have been compiled. Care has been taken to make the charts as clear and as easily understood and, above all, as accurate as possible. They have been based upon theoretical considerations, modified by what is considered to be good practice in this country. CHART 1.--This chart is for determining the number of square feet of heating surface of a low pressure steam heating system, pressure not to exceed 5 lbs. per square inch by the gauge, necessary to supply the heat lost through the various kinds of wall surfaces of rooms. The chart is divided into four parts. CHART 2.--For determining the diameters of the supply and return pipes for a heating system. CHART 3.--For finding the number of square feet of boiler heating surface and the number of square feet of grate surface for a boiler that is to supply steam to a steam heating system. CHART 4.--For determining the area of the cross section of a square flue, or the diameter of a round flue, leading from an indirect radiation heater to the register in a room to be heated. Full details are given for the use of these cards. These four charts are printed on heavy white card-board and bound together with cloth, size 13 in. by 9-1/4 in., $1.00[++]. _These cards are securely packed for mail and sent to any part of the World on receipt of price._ * * * * * Gas Analyst's Manual. By JAQUES ABADY, M. Inst. Mech. E. _(Incorporating F. W. Hartley's "Gas Analyst's Manual" and "Gas Measurement.)"_ EXTRACT FROM PREFACE. The numerous requests received by the Publishers for the late Mr. F. W. Hartley's "Gas Analyst's Manual" and "Gas Measurement" form the justification of the present work, which embodies practically the entire contents of those two volumes. It has been found, however, that their scope was too narrow to comply with modern requirements in various directions, although ample at the time they were written, and so I have ventured to add such extensions as appeared to be necessary in order to meet the demand which exists for a comprehensive work on Gas Apparatus and its use. This large work has been in course of preparation for the past three years by Mr. Jaques Abady, and has been very carefully revised by other experts. Many valuable tables of data have been included, a number of which come from the private note books of the Author, being practically results obtained by him during many years of work as Expert, Gas Engineer and Gas-Works Materials Manufacturer. CONTENTS OF CHAPTERS. 1.--Photometry (58 pages.) 2.--The table photometer and Photometer Room (38 pages.) 3.--Standard of Light (32 pages.) 4.--Calorimetry and Specific Gravity, with a note on Mond Gas (48 pages.) 5.--The Referees' Test for Sulphur and Ammonia in Gas (28 pages.) 6.--Coal Testing (22 pages.) 7.--Testing Enrichment and Purification Materials (33 pages.) 8.--Purity Tests for Gas in the Various Stages of its Manufacture (43 pages.) 9.--Testing Bye-products (35 pages.) 10.--Technical Gas Analysis (63 pages.) 11.--Meter-Testing Apparatus (48 pages.) 12.--Meter and Governor Testing (34 pages.) Appendix. Data, Tables, Formulæ, etc., (38 pages). And very complete Contents, Index and List of Illustrations, and Tables, &c. &c. XV+560 pages, 5-1/2 × 8-1/2 in., 93 illustrations and 9 folding plates. =Bound in Handsome Half Leather - $6.50 [++]= * * * * * The Design and Construction OF OIL ENGINES. WITH FULL DIRECTIONS FOR Erecting, Testing, Installing, Running and Repairing. Including descriptions of American and English KEROSENE OIL ENGINES. By A. H. GOLDINGHAM, M.E. SYNOPSIS OF CONTENTS OF CHAPTERS: 1. Introductory; classification of oil engines; vaporizers; ignition and spraying devices; different cycles of valve movements. 2. On design and construction of oil engines; cylinders; crankshafts; connecting rods; piston and piston rings; fly-wheels; air and exhaust cams, valves and valve boxes; bearings; valve mechanism, gearing and levers; proportions of engine frames; oil-tank and filter; oil supply pipes; different types of oil engines; cylinders made in more than one piece; single cylinder and double cylinder engines; crankpin dimensions; fitting parts; assembling of oil engine; testing water jackets, joints, etc. 3. Testing for leaks, faults, power, efficiency, combustion, compression; defects as shown by indicator; diagrams for setting valves; how to correct faults; indicator fully described; fuel consumption test, etc. 4. Cooling water tanks; capacity of tanks; source of water supply; system of circulation; water pump; exhaust silencers; self starters; utilization of waste heat of exhaust. 5. Oil engines driving dynamo; installation of plant; direct and belt connected; belts; power for electric lighting; loss of power. 6. Oil engines driving air compressors; direct connected and geared; table of pressures; pumping outfits; oil engines driving ice and refrigeration outfits. 7. Full instructions for running different kinds of oil engines. 8. Hints on repairs; adjustment of crank-shaft and connecting rod bearing; testing oil inlet valves and pump, fitting new spur gears, etc. 9. General descriptions with illustrations of American and English oil engines; methods of working; portable oil engines, etc., etc. Index and tables. XIII. + 196 pages, 7-1/2 × 5-1/2, 79 illustrations, cloth, $2.00 * * * * * PRACTICAL HANDBOOK ON GAS ENGINES. _With Instructions for Care and Working of the Same._ By G. LIECKFELD, C.E. TRANSLATED WITH PERMISSION OF THE AUTHOR BY Geo. Richmond, M.E. TO WHICH HAS BEEN ADDED FULL DIRECTIONS FOR THE RUNNING OF OIL ENGINES. CONTENTS. Choosing and installing a gas engine. The construction of good gas engines. Examination as to workmanship. As to running. As to economy. Reliability and durability of gas engines. Cost of installing a gas engine. Proper erection of a gas engine. Construction of the foundation. Arrangement for gas pipes. Rubber bag. Locking devices. Exhaust pipes. Air pipes. Setting up gas engines. Brakes and their use in ascertaining the power of gas engines. Theory of the brake. The Brauer band brake. Arrangement of a brake test. Explanation of the expressions "Brake Power" and "Indicated Power." Comparisons of the results of the brake test and the indicated test. Quantity of work consumed by external friction of the engine. Distribution of heat in a gas engine. Attendance on gas engines. General remarks. Gas engine oil. Cylinder lubricators. Rules as to starting and stopping a gas engine. The cleaning of a gas engine. General observations and specific examination for defects. Different kinds of defectives. The engine refuses to work. Non-starting of the engine. Too much pressure on the gas. Water in the exhaust pot. Difficulty in starting the engine. Clogged slide valve. Leaks in gas pipes. Unexpected stopping of engine. Irregular running. Loss of power. Weak gas mixtures. Late ignition. Cracks in air inlet. Back firing. Knocking and pounding inside of engine. Dangers and precautionary measure in handling gas engines. Examination of gas pipes. Precautions when:-Opening gas valves. Removing piston from cylinder. Examining with light openings of gas engines. Dangers in starting. Dangers in cleaning. Safeguards for fly-wheels. Danger of putting on belts. =Oil Engines.= Gas engines with producer gas. Gasoline and oil engines. The "Hornsby-Akroyd" oil engine. Failure to start. Examination of engine in detail. Vaporizer valve box. Full detailed directions for the management of Oil Engines. Concluding remarks. 120 pages, illustrated, 12mo. cloth. $1.00 * * * * * THE CHEMISTRY OF FIRE AND FIRE PREVENTION. A HANDBOOK FOR INSURANCE SURVEYORS, WORKS MANAGERS, AND ALL INTERESTED IN FIRE RISKS AND THEIR DIMINUTION BY HERBERT INGLE, F.I.C., F.C.S. AND HARRY INGLE, PH.D., B.SC. TECHNOLOGICAL CHEMIST. Contents of Chapters. I. Definition of Fire, Old Theories as to its Nature, Modern Views of Combustion--The Physical and Chemical Properties of the Atmosphere, the Chief Properties of its Constituents--Some Conditions Affecting the Combustion of Substances in Air, the Principle of the Miner's Safety Lamp. II. Explanation of Chemical Terms, Outline of the Atomic Theory. Brief Explanations of the Use of Chemical Formulæ and Equations. III. Methods of Preparations of Oxygen, Brin's Oxygen Manufacture--Heat Measurements, the Calorimeter, Calorific Power of Substances Burning in Air. IV. Coal Gas: Its Preparation, Purification and Composition--Properties of Its Chief Constituents--Reciprocity of Combustion--Gaseous Diffusion--Explosion of Gases--Dust Explosions. V. Fuel: Chemical Composition of Wood, Charcoal, Peat, Lignite, Coal, Coke, Petroleum, Coal Gas--Use of "Atmospheric Burners"--Producer Gas--Water Gas--Dawson Gas. * * * * * CROSS SECTION PAPER. =Scale EIGHT to ONE Inch.= THE HANDY SKETCHING PAD. Printed on one side, in blue ink, all the lines being of equal thickness with useful tables. Size 8 × 10 inches. Price, 25c. each. Per dozen pads, $2.50. THE HANDY SKETCHING BOOK. Made from this paper but printed on both sides. Size of book 5 × 8 inches, stiff board covers. Price, 25c. each; per dozen books, $2.50. =Scale EIGHT to ONE Inch.= A large sheet with heavy inch lines and half inch lines, printed in blue ink. Size of sheet, 17 × 22 inches. Per quire (24 sheets), =Scale TEN to ONE Inch.= Size 17 × 22 inches, printed in blue ink, with heavy inch lines and half inch lines. Per quire (24 sheets), The Electrician's Sketching Book. Made from this paper. Scale 10 to 1 inch. Size of book 5 × 8 inches, with stiff card board covers. Price, 25c. each; per dozen, $2.50. The Electrician's Plotting Pad. Same paper, only printed on one side, size of pad, 8 × 10 inches, 25c; per dozen, $2 50. Any Books and Pads Assorted, per dozen, $2 50. ANY QUANTITY MAILED TO ANY PART OF THE WORLD POST-PAID ON RECEIPT OF PRICE. This paper is _Printed from plates_. Try it and you will find it GOOD, ACCURATE AND CHEAP. SPON & CHAMBERLAIN, NEW YORK, U. S. A. * * * * * 25c. BOOKS. =MODEL BOILER MAKING.= Contains full instructions for designing and making model stationary, marine and locomotive boilers. Fully illustrated with original working drawings. =METAL WORKING TOOLS AND THEIR USES.= A Handbook for Young Engineers and Apprentices. Shows how to use simple tools required in metal working and model making. Illustrated. =SIMPLE MECHANICAL WORKING MODELS.= How to make and use them, including stationary engine locomotive, steamboat, waterwheel, etc. With 34 illustrations. =MODEL STEAMER BUILDING.= A practical handbook on the design and construction of model steamer hulls, and fittings, with 39 scale drawings. =MACHINERY FOR MODEL STEAMERS.= On the design, construction, fitting and erecting of engines and boilers for model steamers, with 44 scale drawings. =THE SLIDE VALVE.= Simply explained for working engineers. Fully illustrated. =THE LOCOMOTIVE=, simply explained. A first introduction to the study of the locomotive engine, their designs, construction and erection, with a short catechism, and 26 illustrations. =THE BEGINNER'S GUIDE TO THE LATHE.= An elementary instruction book on turning in wood and metal. By P. MARSHALL. 76 pages, 75 illustrations. =GAS AND OIL ENGINES.= A practical handbook on, with instructions for care and running. Illustrated. =STANDARD SCREW THREADS.= A Guide to Standard Screw Threads and Twist Drills. (Small sizes.) Illustrated. =STEAM TURBINES.= How to design and build them. A practical handbook for model makers. Contents of Chapters. 1. General Consideration. 2. Pressure Developed by an Impinging Jet; Velocity and Flow of Steam Through Orifices. 3. Method of Designing a Steam Turbine. 4. Complete Designs for DeLaval Steam Turbines; Method of Making Vanes; Shrouding. 5. The Theory of Multiple Stage Turbines. Fully illustrated with detail drawings and tables. =MECHANICAL DRAWING=, simply explained. 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A complete manual for teachers and organizers of woodworking classes. Contents of Chapters: 1. First Year Course. 2. Second Year Course. 3. Third Year Course. 4. Fittings and Furniture. 5. Discipline. 6. Organization and Method. 7. The Instruction of the Physically and Mentally Deficient and Blind. 8. Object Lessons. Fully illustrated with reproductions from photographs, drawings, and facsimile black-board lessons. =158 pages, 12mo., cloth, $1.00 net.= =WOODWORK JOINTS.= How to make and where to use them; including mortise and tenon joints, lap joints, dovetail joints, glue joints and scarfing joints. With a chapter on circular woodwork, revised and enlarged edition, 101 pages, 178 illustrations. =25c.= =THE BEGINNER'S GUIDE TO FRETWORK.= Containing full instructions on the Use of Tools and Materials; and six full size Fretwork designs. With 39 pages and 26 illustrations. =25c.= =VENEERING, MARQUETRY AND INLAY.= A practical instruction book in the art of Decorating Woodwork by these methods. By P. A. WELLS. 79 pages, 37 illustrations. =25c.= =SOFT WOODS AND COLONIAL TIMBERS.= The selection and Uses of Soft Woods and Colonial Timbers. The cultivation, cutting and seasoning. 57 pages, 15 illustrations. =25c.= =HARD WOODS, ENGLISH AND FOREIGN.= A practical description of Hard and Fancy Woods used by the carpenter and cabinet maker. By P. A. WELLS, 79 pages, 19 illustrations, =25c.= * * * * * Spons' Mechanics Own Book =A WORK THAT SHOULD BE IN YOUR BOOKCASE.= The general method of treatment of each subject, is first the raw materials worked upon, its characteristics, variations and suitability; secondly, the tools used, the sharpening and use; thirdly, devoted to typical examples of work to be done, materials, and how to do similar work, etc. THE FOLLOWING ARE THE PRINCIPAL CONTENTS. Mechanical Drawing, (13 pages.) Mechanical Movements, (55 pages.) Casting and Founding in Brass and Bronze, (30 pages.) Forging and Finishing, (46 pages.) Soldering in all its branches, (26 pages.) Sheet Metal Working, (10 pages.) Turning and Turning Lathes, (31 pages.) Carpentry, (224 pages.) Log Huts, Building, Etc., (8 pages.) Cabinet-Making, (36 pages.) Upholstery, (6 pages.) Carving and Fretwork, (13 pages.) Picture Frame Making, (4 pages.) Painting, Graining and Marbling, (28 pages.) Staining, (13 pages.) Gilding, (3 pages.) Polishing, (23 pages.) Varnishing, (4 pages.) Paper Hanging, (4 pages.) Glazing, (7 pages.) Plastering and White Washing, (9 pages.) Lighting, (8 pages.) Foundations and Masonry, (46 pages.) Roofing, (14 pages.) Ventilating and Warming, (13 pages.) Electric Bell and Bell Hanging, Gas Fitting, (8 pages.) Roads and Bridges, Banks, Hedges, Ditches and Drains, Asphalt Cement Floors, Water Supply and Sanitation. Total number of pages 702. Total number illustrations 1,420 Bound in substantial half-extra,--=PRICE BY MAIL ONLY $2.50= We have an 8 page circular giving full contents which will be sent free on application. * * * * * Workshop Receipts. THE MOST COMPLETE Technical Cyclopedia in 5 Vols. =First Series. Principal Contents.=--Bronzes, Cements, Dyeing, Electrometallurgy, Enamels, Etchings, Fireworks, Fluxes, Fulminates, Gilding. Gums, Japanning. Lacquers, Marble Working, Nitro-Glycerine, Photography, Pottery, Varnishes, etc., etc. 420 pages, 108 illustrations, 12mo, cloth, $2.00. =Second Series. Principal Contents.=--Acidimetry, Albumen. Alcohol, Alkaloids, Bitters. Bleaching, Boiler Incrustations, Cleansing, Confectionery, Copying, Disinfectants, Essences. Extracts, Fire-proofing, Glycerine. Gut, Iodine, Ivory Substitutes, Leather, Matches Pigments, Paint, Paper, Parchment, etc., etc. 485 pages, 16 illustrations, 12mo, cloth, $2.00. =Third Series. Principal Contents.=--Alloys, Aluminium, Antimony, Copper, Electrics, Enamels, Glass. Gold, Iron and Steel, Liquors. Lead, Lubricants, Magnesium. Manganese, Mercury, Mica, Nickel, Platinum, Silver, Slag, Tin, Uranium, Zinc, etc., etc. 480 pages, 183 illustrations, 12mo, cloth, $2.00. =Fourth Series. Principal Contents.=--Water-proofing, Packing and Stowing, Embalming and Preserving Leather Polishes, Cooling Air and Water. Pumps and Siphons, Dessicating. Distilling, Emulsifying, Evaporating, Filtering, Percolating and Macerating. Electrotyping, Stereotyping. Book-binding, Straw-plaiting, Musical Instruments, Clock and Watch Mending, Photography, etc., etc. 443 pages, 243 illustrations, 12mo, cloth, $2 00. =Fifth Series. Principal Contents.=--Diamond Cutting, Laboratory Apparatus, Copying, Filtering, Fire-proofing. Magic Lanterns, Metal Work. Percolation, Illuminating Agents, Tobacco Pipes, Taps, Tying and Splicing. Tackle Repairing Books. Netting, Walking Sticks Boat-Building, etc., etc. 440 pages, 373 illustrations, 12mo, cloth, $2.00. =EACH SERIES has its own Contents and Index and is complete in itself.= * * * * * SPONS' ENCYCLOPÆDIA OF THE Industrial Arts, Manufactures AND Commercial Products. EDITED BY G. G. ANDRE, F.G.S., Asso.-M. Inst. C.E. AND C. G. WARNFORD LOCK, F.L.S., F.G.S., M.I.M.M. Assisted by many prominent Manufacturers, Chemists and Scientists. This encyclopedia is written by practical men for practical men. _Raw Materials_ form perhaps its most important feature and are dealt with in a way never before attempted. _Manufacturers_ are discussed in detail from the manufacturing standpoint by manufacturers of acknowledged reputation. Special consideration is given to the utilization of waste, the prevention of nuisance, and the question of adulterations. Technicalities are explained, and bibliographies (English, American, French, German, etc.), are appended to the principal articles. Over 2,000 pages and nearly 2,000 illustrations. We are offering a _Limited_ number of sets of a =SPECIAL THREE VOLUME EDITION HANDSOMELY BOUND IN HALF-MOROCCO, CLOTH-GILT, MARBLED EDGES, $15.00 NET.= A full descriptive circular can be had on application. * * * * * Dubelle's Famous Formulas. KNOWN AS Non Plus Ultra Soda Fountain Requisites of Modern Times. By G. H. DUBELLE. _A practical Receipt Book for Druggists, Chemists, Confectioners and Venders of Soda Water._ SYNOPSIS OF CONTENTS. INTRODUCTION.--Notes on natural fruit juices and improved methods for their preparation. Selecting the fruit. Washing and pressing the fruit. Treating the juice. Natural fruit syrups and mode of preparation. Simple or stock syrups. =FORMULAS.= FRUIT SYRUPS.--Blackberry, black currant, black raspberry, catawba, cherry, concord grape, cranberry, lime, peach, pineapple, plum, quince, raspberry, red current, red orange, scuppernong grape, strawberry, wild grape. NEW IMPROVED ARTIFICIAL FRUIT SYRUPS.--Apple, apricot, banana, bitter orange, blackberry, black currant, cherry, citron, curacoa, grape, groseille, lemon, lime, mandarin, mulberry, nectarine, peach, pear, pineapple, plum, quince, raspberry, red current, strawberry, sweet orange, tangerine, vanilla. FANCY SODA FOUNTAIN SYRUPS.--Ambrosia, capillaire, coca-kina, coca-vanilla, coca-vino, excelsior, imperial, kola-coca, kola-kina, kola-vanilla, kola-vino, nectar, noyean, orgeat, sherbet, syrup of roses, syrup of violets. ARTIFICIAL FRUIT ESSENCES.--Apple, apricot, banana, bergamot, blackberry, black cherry, black currant, blueberry, citron, cranberry, gooseberry, grape, lemon, lime fruit, melon, nectarine, orange, peach, pear, pineapple, plum, quince, raspberry, red currant, strawberry. CONCENTRATED FRUIT PHOSPHATES.--Acid solution of phosphate, strawberry, tangerine, wild cherry.--29. different formulas. NEW MALT PHOSPHATES--36. FOREIGN AND DOMESTIC WINE PHOSPHATES--9. CREAM-FRUIT LACTARTS--28. SOLUBLE FLAVORING EXTRACTS AND ESSENCES--14. NEW MODERN PUNCHES--18. MILK PUNCHES--17. FRUIT PUNCHES--32. FRUIT MEADS--18. NEW FRUIT CHAMPAGNES--17. NEW EGG PHOSPHATES--14. FRUIT JUICE SHAKES--24. EGG PHOSPHATE SHAKES. HOT EGG PHOSPHATE SHAKES. WINE BITTER SHAKES--12. SOLUBLE WINE BITTERS EXTRACTS--12. NEW ITALIAN LEMONADES--18. ICE CREAM SODAS--39. NON-POISONOUS COLORS. FOAM PREPARATIONS. MISCELLANEOUS FORMULAS--26. LATEST NOVELTIES IN SODA FOUNTAIN MIXTURES--7. TONICS.--Beef, iron and cinchona; hypophosphite; beef and coca; beef, wine and iron; beef, wine, iron and cinchona; coca and calisaya. LACTARTS.--Imperial tea; mocha coffee; nectar; Persian sherbert. PUNCHES. EXTRACTS.--Columbia root beer; ginger tonic; soluble hop ale. LEMONADES.--French; Vienna. Egg nogg. Hop ale. Hot tom. Malt wine. Sherry cobbler. Saratoga milk shake. Pancretin and wine. Kola-coco cordial. Iron malt phosphate. Pepsin, wine and iron, etc. =157 Pages, Nearly 500 Formulas. 12mo, Cloth. $1= * * * * * Latest practice, New and original cuts. KATHARINE MELLISH'S COOKERY AND DOMESTIC MANAGEMENT. SYNOPSIS OF CONTENTS. Complete Breakfast Menus, with receipts, pages 1-27. Complete Luncheon Menus, with receipts, pages 28-74. Tea Menus, High Tea Menus, with receipts, pages 75-124. Complete Dinner Menus, with receipts, pages 125-220. Processes:--This chapter is illustrated with exact position of the =cook's hands= during the various operations of preparing, boning birds and joints, trussing fish, joints, poultry, game, hares, rabbits, etc. Larding and icing, etc. Receipts of separate dishes. Stocks and soups of all kinds, broth, gravy, etc. Fish.--To clean, general rules for cooking. Numerous receipts or boiling, baking, stewing, frying fish of all kinds. The preparation and making of gravies, stuffing, forcemeats, purees, garnishes and sauces for all purposes, with many receipts. Entrees.--Their preparation and serving, with receipts. Joints.--Preparation, cooking and serving of, with many receipts. Vegetables.--Preparation and cooking of plain and dressed vegetables of all kinds and how to serve them. Poultry and game.--Preparation, cooking and serving, with receipts. Pastries, pudding and sweet dishes. Cakes, biscuits, bread. Omelets.--With receipts for preparing, cooking and serving. Ices, confectionery, syrups, jams, preserves and preserving, cordials, liqueurs, and aerated drinks. Cookery for invalids, carving, serving, etc., etc., and very complete index and contents. =987 pages, 56 full page colored plates, 439 illus. Size, 7-1/4 in. × 10-1/4 in. × 2-1/2 in. Full waterproof texederm in 1, 3 or 5 vols.= * * * * * Published Weekly, Annual subscription, Subscription 6 months, $1.50 Single numbers, 8c. $3.00 postpaid. " 4 " $1.00 THE MODEL ENGINEER AND ELECTRICIAN. The BEST Paper for Young Engineers, Students, Model Makers, Apprentices, and all interested in Mechanical and Electrical Work. SPECIAL FEATURES. =Practical Articles= by experienced writers on the construction and working of model steam, gas and oil engines; model locomotives and railways; model boilers; model steam and electric launches, and sailing yachts; lathes and metal and wood-working tools; pattern-making; brass and iron founding; forging; model dynamos and motors; electric bells, telephones and batteries; accumulators; electric lighting; influence machines; electrical experiments; motor cycles, &c., &c. =Model Engineers and their Work.=--Illustrated interviews with prominent model engineers, describing their workshops, their methods of working; and some of their models. =Our Beginners' Column.=--A section devoted to elementary instruction on the use of tools; the making of simple apparatus and models, and the carrying out of easy experiments. =Practical Letters from our Readers.=--A correspondence column, wherein readers can describe workshop appliances or methods of their own invention and discuss practical matters of mutual interest. =Amateurs' Supplies.=--Under this heading short descriptions of new tools, apparatus and materials are inserted, thus keeping the reader posted up in the latest improvements. =A System of Queries and Replies=, by which all readers of the journal can obtain information and advice on mechanical or electrical subjects. =Original Working Drawings= and high-class illustrations are a regular feature of the journal. =Prize Competitions= open to all readers, are announced from time to time, on all subjects. =Model Yachting=, Notes, New Books, &c., &c. All subscriptions should be sent to SPON & CHAMBERLAIN, Sole American Agents. 123-125 Liberty Street, New York, U.S.A. * * * * * Transcriber's Notes: The original spelling and minor inconsistencies in the spelling and formatting have been maintained. Inconsistent hyphenation is as in the original if not marked as a misprint. Text in italics has been marked with underscores (_text_) and bold text with egual signs (=text=) Inconsistent smallcap mark-up of the word Fig. in captions has been harmonized to FIG. Missing punctuation in the advertisement at the end of the book has been added. Table A has been re-arranged to fit the line size. Table II and B have been split into two parts. The table below lists all corrections applied to the original text. p. ix: Gay-Lassacs -> Lussac's p. x: for molasses. Transportion -> Transportation p. xii: 30, 31, -> 30, 31 p. 8: Mashes, and Fermentation -> Fermentation. p. 11: Company, of Cincinnati -> Cincinnati, p. 11: illustrated in Fig -> Fig. p. 15: stirrer arms B -> _B_ p. 16: driving shaft F -> _F_ p. 22: This is know -> known p. 26: of the yeast stops -> stops. p. 40: pipes G G G -> _G G G_ p. 40: in the worm, -> worm. p. 57: as the chamber B -> _B_ p. 64: Fig. 22.--Diagramatie -> Diagramatic p. 68: depriving it of its aclohol -> alcohol p. 72: Gauge Glass for Regulatar -> Regulator p. 73: runnings or ".feints." -> "feints." p. 73: Fig. 29 -> 29. p. 80: the column _A_ -> _A_. p. 94: more highly varporized -> vaporized p. 107: being kept at 65°F -> 65° F p. 117: saccharification takes place -> place. p. 138: steam is admitted though -> through p. 145: is required per arce -> acre p. 149: which is varied accroding -> according p. 158: FIF. -> FIG. p. 185: starch a blue color, -> color. p. 186: may contain numerious -> numerous p. 186: processes are largely empirical -> empirical. p. 191: in the still in Fig. 8 -> 8. p. 192: money for their proprieters -> proprietors p. 195: constructed, however, to pervent -> prevent p. 195: After the chief feremnting -> fermenting p. 198: rectifying columns, refrigerators -> refrigerators, p. 198: FIG. 56 -> 55 p. 206: FIG 59. -> FIG. 59. p. 218: 100 gallons -> gallons. p. 218: Ethyl Alcohol--100 gallons. -> Ethyl Alcohol 100 gallons. p. 219: 100 gallons -> gallons. p. 220: and similar products -> products. p. 221: on metallic susbtances -> substances p. 239: used for de-naturign -> de-naturing p. 246: employees for the work. -> work" p. 251: subject to the penalites -> penalties p. 256: de-natured spirits is -> are p. 259: tax free of domestic alchohol -> alcohol p. 272: Prof. Silvanus P. Thomson -> Thompson p. 275: thermostats, annnuciators -> annunciators p. 285: DIGRAM -> DIAGRAM p. 292: "Gas Analyst's Manual -> Manual" p. 292: Mond Gas (48 pages) -> (48 pages.) p. 292: Tables, Formulae -> Formulæ p. 294: "Hornsby-Akroyd' -> "Hornsby-Akroyd" p. 302: Blackberry, black current -> currant p. 302: orange, blackberry, black current -> currant X/ 
21724	----	generously made available by The Internet Archive/Million Book Project.) THE HANDBOOK OF SOAP MANUFACTURE BY W. H. SIMMONS, B.Sc. (LOND.), F.C.S. AND H. A. APPLETON _WITH TWENTY-SEVEN ILLUSTRATIONS_ LONDON SCOTT, GREENWOOD & SON "THE OIL AND COLOUR TRADES JOURNAL" OFFICES 8 BROADWAY, LUDGATE HILL, E.C. 1908 [_All rights reserved_] Transcriber's note: For text: A word surrounded by a cedilla such as ~this~ signifies that the word is bolded in the text. A word surrounded by underscores like _this_ signifies the word is italics in the text. Greek letters are translated into English and are in brackets, e.g. [alpha]. For numbers and equations: Parentheses have been added to clarify fractions. Underscores before bracketed numbers/letters in equations denote a subscript. Footnotes have been moved to the end of the chapter and minor typos have been corrected. PREFACE In the general advance of technical knowledge and research during the last decade, the Soap Industry has not remained stationary. While there has not perhaps been anything of a very revolutionary character, steady progress has still been made in practically all branches, and the aim of the present work is to describe the manufacture of Household and Toilet Soaps as carried out to-day in an up-to-date and well-equipped factory. In the more scientific portions of the book, an acquaintance with the principles of elementary chemistry is assumed, and in this we feel justified, as in these days of strenuous competition, no soap-maker can hope to compete successfully with his rivals unless he has a sound theoretical as well as practical knowledge of the nature of the raw materials he uses, and the reactions taking place in the pan, or at other stages of the manufacture. We also venture to hope that the work may prove useful to Works' Chemists and other Analysts consulted in connection with this Industry. At the same time, in the greater part of the book no chemical knowledge is necessary, the subject being treated in such a way that it is hoped those who are not directly engaged in the manufacture of soap, but who desire a general idea of the subject, will find it of value. In the sections dealing with the composition and analysis of materials, temperatures are expressed in degrees Centigrade, these being now almost invariably used in scientific work. In the rest of the book, however, they are given in degrees Fahrenheit (the degrees Centigrade being also added in brackets), as in the majority of factories these are still used. As regards strengths of solution, in some factories the use of Baumé degrees is preferred, whilst in others Twaddell degrees are the custom, and we have therefore given the two figures in all cases. In the chapter dealing with Oils and Fats, their Saponification Equivalents are given in preference to Saponification Values, as it has been our practice for some years to express our results in this way, as suggested by Allen in _Commercial Organic Analysis_, and all our records, from which most of the figures for the chief oils and fats are taken, are so stated. For the illustrations, the authors are indebted to Messrs. E. Forshaw & Son, Ltd., H. D. Morgan, and W. J. Fraser & Co., Ltd. W. H. S. H. A. A. LONDON, _September_, 1908. CONTENTS PAGE CHAPTER I. INTRODUCTION. 1 Definition of Soap--Properties--Hydrolysis--Detergent Action. CHAPTER II. CONSTITUTION OF OILS AND FATS, AND THEIR SAPONIFICATION 6 Researches of Chevreul and Berthelot--Mixed Glycerides--Modern Theories of Saponification--Hydrolysis accelerated by (1) HEAT OR ELECTRICITY, (2) FERMENTS, Castor-seed Ferment, Steapsin, Emulsin, and (3) CHEMICAL REAGENTS, Sulphuric Acid, Twitchell's Reagent, Hydrochloric Acid, Lime, Magnesia, Zinc Oxide, Soda and Potash. CHAPTER III. RAW MATERIALS USED IN SOAP-MAKING 24 Fats and Oils--Waste Fats--Fatty Acids--Less-known Oils and Fats of Limited Use--Various New Fats and Oils Suggested for Soap-making--Rosin--Alkali (Caustic and Carbonated)--Water--Salt--Soap-stock. CHAPTER IV. BLEACHING AND TREATMENT OF RAW MATERIALS INTENDED FOR SOAP-MAKING 41 Palm Oil--Cotton-seed Oil--Cotton-seed "Foots"--Vegetable Oils--Animal Fats--Bone Fat--Rosin. CHAPTER V. SOAP-MAKING 45 Classification of Soaps--Direct combination of Fatty Acids with Alkali--Cold Process Soaps--Saponification under Increased or Diminished Pressure--Soft Soap--Marine Soap--Hydrated Soaps, Smooth and Marbled--Pasting or Saponification--Graining Out--Boiling on Strength--Fitting--Curd Soaps--Curd Mottled--Blue and Grey Mottled Soaps--Milling Base--Yellow Household Soaps--Resting of Pans and Settling of Soap--Utilisation of Nigres--Transparent soaps--Saponifying Mineral Oil--Electrical Production of Soap. CHAPTER VI. TREATMENT OF SETTLED SOAP 60 Cleansing--Crutching--Liquoring of Soaps--Filling--Neutralising, Colouring and Perfuming--Disinfectant Soaps--Framing--Slabbing--Barring--Open and Close Piling--Drying--Stamping--Cooling. CHAPTER VII. TOILET, TEXTILE AND MISCELLANEOUS SOAPS 77 Toilet Soaps--Cold Process soaps--Settled Boiled Soaps--Remelted Soaps--Milled Soaps--Drying--Milling and Incorporating Colour, Perfume, or Medicament--Perfume--Colouring matter--Neutralising and Superfatting Material--Compressing--Cutting--Stamping--Medicated Soaps--Ether Soap--Floating Soaps--Shaving Soaps--Textile Soaps--Soaps for Woollen, Cotton and Silk Industries--Patent Textile Soaps--Miscellaneous Soaps. CHAPTER VIII. SOAP PERFUMES 95 Essential Oils--Source and Preparation--Properties--Artificial and Synthetic Perfumes. CHAPTER IX. GLYCERINE MANUFACTURE AND PURIFICATION 111 Treatment of Lyes--Evaporation to Crude Glycerine--Distillation--Distilled and Dynamite Glycerine--Chemically Pure Glycerine--Animal Charcoal for Decolorisation--Glycerine obtained by other methods of Saponification--Yield of Glycerine from Fats and Oils. CHAPTER X. ANALYSIS OF RAW MATERIALS, SOAP, AND GLYCERINE 117 Fats and Oils--Alkalies and Alkali Salts--Essential Oils--Soap--Lyes--Crude Glycerine. CHAPTER XI. STATISTICS OF THE SOAP INDUSTRY 140 APPENDIX A. COMPARISON OF DEGREES, TWADDELL AND BAUMÉ, WITH ACTUAL DENSITIES 147 APPENDIX B. COMPARISON OF DIFFERENT THERMOMETRIC SCALES 148 APPENDIX C. TABLE OF THE SPECIFIC GRAVITIES OF SOLUTIONS OF CAUSTIC SODA 149 APPENDIX D. TABLE OF STRENGTH OF CAUSTIC POTASH SOLUTIONS AT 60° F. 151 INDEX 153 CHAPTER I. INTRODUCTION. _Definition of Soap--Properties--Hydrolysis--Detergent Action._ It has been said that the use of soap is a gauge of the civilisation of a nation, but though this may perhaps be in a great measure correct at the present day, the use of soap has not always been co-existent with civilisation, for according to Pliny (_Nat. Hist._, xxviii., 12, 51) soap was first introduced into Rome from Germany, having been discovered by the Gauls, who used the product obtained by mixing goats' tallow and beech ash for giving a bright hue to the hair. In West Central Africa, moreover, the natives, especially the Fanti race, have been accustomed to wash themselves with soap prepared by mixing crude palm oil and water with the ashes of banana and plantain skins. The manufacture of soap seems to have flourished during the eighth century in Italy and Spain, and was introduced into France some five hundred years later, when factories were established at Marseilles for the manufacture of olive-oil soap. Soap does not appear to have been made in England until the fourteenth century, and the first record of soap manufacture in London is in 1524. From this time till the beginning of the nineteenth century the manufacture of soap developed very slowly, being essentially carried on by rule-of-thumb methods, but the classic researches of Chevreul on the constitution of fats at once placed the industry upon a scientific basis, and stimulated by Leblanc's discovery of a process for the commercial manufacture of caustic soda from common salt, the production of soap has advanced by leaps and bounds until it is now one of the most important of British industries. _Definition of Soap_.--The word soap (Latin _sapo_, which is cognate with Latin _sebum_, tallow) appears to have been originally applied to the product obtained by treating tallow with ashes. In its strictly chemical sense it refers to combinations of fatty acids with metallic bases, a definition which includes not only sodium stearate, oleate and palmitate, which form the bulk of the soaps of commerce, but also the linoleates of lead, manganese, etc., used as driers, and various pharmaceutical preparations, _e.g._, mercury oleate (_Hydrargyri oleatum_), zinc oleate and lead plaster, together with a number of other metallic salts of fatty acids. Technically speaking, however, the meaning of the term soap is considerably restricted, being generally limited to the combinations of fatty acids and alkalies, obtained by treating various animal or vegetable fatty matters, or the fatty acids derived therefrom, with soda or potash, the former giving hard soaps, the latter soft soaps. The use of ammonia as an alkali for soap-making purposes has often been attempted, but owing to the ease with which the resultant soap is decomposed, it can scarcely be looked upon as a product of much commercial value. H. Jackson has, however, recently patented (Eng. Pat. 6,712, 1906) the use of ammonium oleate for laundry work. This detergent is prepared in the wash-tub at the time of use, and it is claimed that goods are cleansed by merely immersing them in this solution for a short time and rinsing in fresh water. Neither of the definitions given above includes the sodium and potassium salts of rosin, commonly called rosin soap, for the acid constituents of rosin have been shown to be aromatic, but in view of the analogous properties of these resinates to true soap, they are generally regarded as legitimate constituents of soap, having been used in Great Britain since 1827, and receiving legislative sanction in Holland in 1875. Other definitions of soap have been given, based not upon its composition, but upon its properties, among which may be mentioned that of Kingzett, who says that "Soap, considered commercially, is a body which on treatment with water liberates alkali," and that of Nuttall, who defines soap as "an alkaline or unctuous substance used in washing and cleansing". _Properties of Soap._--Both soda and potash soaps are readily soluble in either alcohol or hot water. In cold water they dissolve more slowly, and owing to slight decomposition, due to hydrolysis (_vide infra_), the solution becomes distinctly turbid. Sodium oleate is peculiar in not undergoing hydrolysis except in very dilute solution and at a low temperature. On cooling a hot soap solution, a jelly of more or less firm consistence results, a property possessed by colloidal bodies, such as starch and gelatine, in contradistinction to substances which under the same conditions deposit crystals, due to diminished solubility of the salt at a lower temperature. Krafft (_Journ. Soc. Chem. Ind._, 1896, 206, 601; 1899, 691; and 1902, 1301) and his collaborators, Wiglow, Strutz and Funcke, have investigated this property of soap solutions very fully, the researches extending over several years. In the light of their more recent work, the molecules, or definite aggregates of molecules, of solutions which become gelatinous on cooling move much more slowly than the molecules in the formation of a crystal, but there is a definite structure, although arranged differently to that of a crystal. In the case of soda soaps the colloidal character increases with the molecular weight of the fatty acids. Soda soaps are insoluble in concentrated caustic lyes, and, for the most part, in strong solutions of sodium chloride, hence the addition of caustic soda or brine to a solution of soda soap causes the soap to separate out and rise to the surface. Addition of brine to a solution of potash soap, on the other hand, merely results in double decomposition, soda soap and potassium chloride being formed, thus:-- C_{17}H_{35}COOK + NaCl = C_{17}H_{35}COONa + KCl potassium sodium sodium potassium stearate chloride stearate chloride The solubility of the different soaps in salt solution varies very considerably. Whilst sodium stearate is insoluble in a 5 per cent. solution of sodium chloride, sodium laurate requires a 17 per cent. solution to precipitate it, and sodium caproate is not thrown out of solution even by a saturated solution. _Hydrolysis of Soap_.--The term "hydrolysis" is applied to any resolution of a body into its constituents where the decomposition is brought about by the action of water, hence when soap is treated with _cold_ water, it is said to undergo hydrolysis, the reaction taking place being represented in its simplest form by the equation:-- 2NaC_{18}H_{35}O_{2} + H_{2}O = NaOH + HNa(C_{18}H_{35}O_{2})_{2} sodium water caustic acid sodium stearate soda stearate The actual reaction which occurs has been the subject of investigation by many chemists, and very diverse conclusions have been arrived at. Chevreul, the pioneer in the modern chemistry of oils and fats, found that a small amount of alkali was liberated, as appears in the above equation, together with the formation of an acid salt, a very minute quantity of free fatty acid remaining in solution. Rotondi (_Journ. Soc. Chem. Ind._, 1885, 601), on the other hand, considered that a neutral soap, on being dissolved in water, was resolved into a basic and an acid salt, the former readily soluble in both hot and cold water, the latter insoluble in cold water, and only slightly soluble in hot water. He appears, however, to have been misled by the fact that sodium oleate is readily soluble in cold water, and his views have been shown to be incorrect by Krafft and Stern (_Ber. d. Chem. Ges._, 1894, 1747 and 1755), who from experiments with pure sodium palmitate and stearate entirely confirm the conclusions arrived at by Chevreul. The extent of dissociation occurring when a soap is dissolved in water depends upon the nature of the fatty acids from which the soap is made, and also on the concentration of the solution. The sodium salts of cocoa-nut fatty acids (capric, caproic and caprylic acids) are by far the most easily hydrolysed, those of oleic acid and the fatty acids from cotton-seed oil being dissociated more readily than those of stearic acid and tallow fatty acids. The decomposition increases with the amount of water employed. The hydrolytic action of water on soap is affected very considerably by the presence of certain substances dissolved in the water, particularly salts of calcium and magnesium. Caustic soda exerts a marked retarding effect on the hydrolysis, as do also ethyl and amyl alcohols and glycerol. _Detergent Action of Soap._--The property possessed by soap of removing dirt is one which it is difficult to satisfactorily explain. Many theories, more or less complicated, have been suggested, but even now the question cannot be regarded as solved. The explanation commonly accepted is that the alkali liberated by hydrolysis attacks any greasy matter on the surface to be cleansed, and, as the fat is dissolved, the particles of dirt are loosened and easily washed off. Berzelius held this view, and considered that the value of a soap depended upon the ease with which it yielded free alkali on solution in water. This theory is considered by Hillyer (_Journ. Amer. Chem. Soc._, 1903, 524), however, to be quite illogical, for, as he points out, the liberated alkali would be far more likely to recombine with the acid or acid salt from which it has been separated, than to saponify a neutral glyceride, while, further, unsaponifiable greasy matter is removed by soap as easily as saponifiable fat, and there can be no question of any chemical action of the free alkali in its case. Yet another argument against the theory is that hydrolysis is greater in cold and dilute solutions, whereas hot concentrated soap solutions are generally regarded as having the best detergent action. Rotondi (_Journ. Soc. Chem. Ind._, 1885, 601) was of the opinion that the basic soap, which he believed to be formed by hydrolysis, was alone responsible for the detergent action of soap, this basic soap dissolving fatty matter by saponification, but, as already pointed out, his theory of the formation of a basic soap is now known to be incorrect, and his conclusions are therefore invalid. Several explanations have been suggested, based on the purely physical properties of soap solutions. Most of these are probably, at any rate in part, correct, and there can be little doubt that the ultimate solution of the problem lies in this direction, and that the detergent action of soap will be found to depend on many of these properties, together with other factors not yet known. Jevons in 1878 in some researches on the "Brownian movement" or "pedesis" of small particles, a movement of the particles which is observed to take place when clay, iron oxide, or other finely divided insoluble matter is suspended in water, found that the pedetic action was considerably increased by soap and sodium silicate, and suggested that to this action of soap might be attributed much of its cleansing power. Alder Wright considered that the alkali liberated by hydrolysis in some way promoted contact of the water with the substance to be cleansed, and Knapp regarded the property of soap solutions themselves to facilitate contact of the water with the dirt, as one of the chief causes of the efficacy of soap as a detergent. Another way in which it has been suggested that soap acts as a cleanser is that the soap itself or the alkali set free by hydrolysis serves as a lubricant, making the dirt less adherent, and thus promoting its removal. The most likely theory yet advanced is that based on the emulsifying power of soap solutions. The fact that these will readily form emulsions with oils has long been known, and the detergent action of soap has frequently been attributed to it, the explanation given being that the alkali set free by the water emulsifies the fatty matter always adhering to dirt, and carries it away in suspension with the other impurities. Experiments by Hillyer (_loc. cit._) show, however, that while N/10 solution of alkali will readily emulsify a cotton-seed oil containing free acidity, no emulsion is produced with an oil from which all the acidity has been removed, or with kerosene, whereas a N/10 solution of sodium oleate will readily give an emulsion with either, thus proving that the emulsification is due to the soap itself, and not to the alkali. Plateau (_Pogg. Ann._, 141, 44) and Quincke (_Wiedmann's. Ann._, 35, 592) have made very complete researches on the emulsification and foaming of liquids and on the formation of bubbles. The former considers that there are two properties of a liquid which play an important part in the phenomenon, (1) it must have considerable viscosity, and (2) its surface tension must be low. Quincke holds similar views, but considers that no pure liquid will foam. Soap solution admirably fulfils Plateau's second condition, its surface tension being only about 40 per cent. of that of water, while its cohesion is also very small; and it is doubtless to this property that its emulsifying power is chiefly due. So far as viscosity is concerned, this can have but little influence, for a 1 per cent. solution of sodium oleate, which has a viscosity very little different from that of pure water, is an excellent emulsifying agent. Hillyer, to whose work reference has already been made, investigated the whole question of detergent action very exhaustively, and, as the result of a very large number of experiments, concludes that the cleansing power of soap is largely or entirely to be explained by the power which it has of emulsifying oily substances, of wetting and penetrating into oily textures, and of lubricating texture and impurities so that these may be removed easily. It is thought that all these properties may be explained by taking into account the low cohesion of the soap solutions, and their strong attraction or affinity to oily matter, which together cause the low surface tension between soap solution and oil. CHAPTER II. CONSTITUTION OF OILS AND FATS, AND THEIR SAPONIFICATION. _Researches of Chevreul and Berthelot--Mixed Glycerides--Modern Theories of Saponification--Hydrolysis accelerated by (1) Heat or Electricity, (2) Ferments; Castor-seed Ferment, Steapsin, Emulsin, and (3) Chemical Reagents; Sulphuric Acid, Twitchell's Reagent, Hydrochloric Acid, Lime, Magnesia, Zinc Oxide, Soda and Potash._ The term oil is of very wide significance, being applied to substances of vastly different natures, both organic and inorganic, but so far as soap-making materials are concerned, it may be restricted almost entirely to the products derived from animal and vegetable sources, though many attempts have been made during the last few years to also utilise mineral oils for the preparation of soap. Fats readily become oils on heating beyond their melting points, and may be regarded as frozen oils. Although Scheele in 1779 discovered that in the preparation of lead plaster glycerol is liberated, soap at that time was regarded as a mere mechanical mixture, and the constitution of oils and fats was not properly understood. It was Chevreul who showed that the manufacture of soap involved a definite chemical decomposition of the oil or fat into fatty acid and glycerol, the fatty acid combining with soda, potash, or other base, to form the soap, and the glycerol remaining free. The reactions with stearin and palmitin (of which tallow chiefly consists) and with olein (found largely in olive and cotton-seed oils) are as follows:-- CH_{2}OOC_{18}H_{35} CH_{2}OH | | CHOOC_{18}H_{35} + 3NaOH = 3NaOOC_{18}H_{35} + CHOH | | CH_{2}OOC_{18}H_{35} CH_{2}OH stearin sodium sodium glycerol hydroxide stearate CH_{2}OOC_{16}H_{31} CH_{2}OH | | CHOOC_{16}H_{31} + 3NaOH = 3NaOOC_{16}H_{31} + CHOH | | CH_{2}OOC_{16}H_{31} CH_{2}OH palmitin sodium sodium glycerol hydroxide palmitate CH_{2}OOC_{18}H_{33} CH_{2}OH | | CHOOC_{18}H_{33} + 3NaOH = 3NaOOC_{18}H_{33} + CHOH | | CH_{2}OOC_{18}H_{33} CH_{2}OH olein sodium sodium glycerol hydroxide oleate Berthelot subsequently confirmed Chevreul's investigations by directly synthesising the fats from fatty acids and glycerol, the method he adopted consisting in heating the fatty acids with glycerol in sealed tubes. Thus, for example:-- 3C_{18}H_{35}O_{2}H + C_{3}H_{5}(OH)_{3} = C_{3}H_{5}(C_{18}H_{35}O_{2})_{3} stearic acid glycerol tristearin Since glycerol is a trihydric alcohol, _i.e._, contains three hydroxyl (OH) groups, the hydrogen atoms of which are displaceable by acid radicles, the above reaction may be supposed to take place in three stages. Thus, we may have:-- (1) C_{18}H_{35}O_{2}H + C_{3}H_{5}(OH)_{3} = C_{3}H_{5}(OH)_{2}C_{18}H_{35}O_{2} + H_{2}O monostearin (2) C_{18}H_{35}O_{2}H + C_{3}H_{5}(OH)_{2}C_{18}H_{35}O_{2} = C_{3}H_{5}(OH)(C_{18}H_{35}O_{2})_{2} + H_{2}O distearin (3) C_{18}H_{35}O_{2}H + C_{3}H_{5}(OH)(C_{18}H_{35}O_{2})_{2} = C_{3}H_{5}(C_{18}H_{35}O_{2})_{3} + H_{2}O tristearin There are two possible forms of monoglyceride and diglyceride, according to the relative position of the acid radicle, these being termed alpha and beta respectively, and represented by the following formulæ, where R denotes the acid radicle:-- _Monoglyceride_:-- CH_{2}OR CH_{2}OH | | (alpha) CHOH and (beta) CHOR | | CH_{2}OH CH_{2}OH _Diglyceride_:-- CH_{2}OR CH_{2}OR | | (alpha) CHOH and (beta) CHOR | | CH_{2}OR CH_{2}OH According to the relative proportions of fatty acid and glycerol used, and the temperature to which they were heated, Berthelot succeeded in preparing mono-, di- and triglycerides of various fatty acids. Practically all the oils and fats used in soap-making consist of mixtures of these compounds of glycerol with fatty acids, which invariably occur in nature in the form of triglycerides. It was formerly considered that the three acid radicles in any naturally occurring glyceride were identical, corresponding to the formula-- CH_{2}OR | CHOR | CH_{2}OR where R denotes the acid radicle. Recent work, however, has shown the existence of several so-called _mixed glycerides_, in which the hydroxyls of the same molecule of glycerol are displaced by two or sometimes three different acid radicles. The first mixed glyceride to be discovered was oleodistearin, C_{3}H_{5}(OC_{18}H_{35}O)(OC_{18}H_{35}O)_{2}, obtained by Heise in 1896 Mkani fat. Hansen has since found that tallow contains oleodipalmitin, from C_{3}H_{5}(OC_{18}H_{35}O)(OC_{16}H_{31}O), stearodipalmitin, C_{3}H_{5}(OC_{18}H_{35}O)(OC_{16}H_{31}O), oleopalmitostearin, C_{3}H_{5}(OC_{18}H_{33}O)(OC_{16}H_{31}O)(OC_{18}H_{35}O) and palmitodistearin, CH(OC_{16}H_{31}O)(OC_{18}H_{35}O)_{2}, the latter of which has also been obtained by Kreis and Hafner from lard, while Holde and Stange have shown that olive oil contains from 1 to 2 per cent. of oleodidaturin, C_{3}H_{5}(OC_{18}H_{33}O)(OC_{17}H_{33}O)_{2}, and Hehner and Mitchell have obtained indications of mixed glycerides in linseed oil (which they consider contains a compound of glycerol with two radicles of linolenic acid and one radicle of oleic acid), also in cod-liver, cod, whale and shark oils. In some cases the fatty acids are combined with other bases than glycerol. As examples may be cited beeswax, containing myricin or myricyl palmitate, and spermaceti, consisting chiefly of cetin or cetyl palmitate, and herein lies the essential difference between fats and waxes, but as these substances are not soap-making materials, though sometimes admixed with soap to accomplish some special object, they do not require further consideration. The principal pure triglycerides, with their formulæ and chief constants, are given in the following table:-- [Transcriber's note: Table split to fit on page better.] --------------------------------------------------------------------- Glyceride. | Formula. | Chief Occurrence. --------------------------------------------------------------------- Butyrin | C_{3}H_{5}(O.C_{4}H_{7}O)_{3} | Butter fat --------------------------------------------------------------------- Isovalerin | C_{3}H_{5}(O.C_{5}H_{9}O)_{3} | Porpoise, dolphin --------------------------------------------------------------------- Caproin | C_{3}H_{5}(O.C_{6}H_{11}O)_{3} | Cocoa-nut and | | palm-nut oils --------------------------------------------------------------------- Caprylin | C_{3}H_{5}(O.C_{8}H_{15}O)_{3} | Do. do. --------------------------------------------------------------------- Caprin | C_{3}H_{5}(O.C_{10}H_{19}O)_{3} | Do. do. --------------------------------------------------------------------- Laurin | C_{3}H_{5}(O.C_{12}H_{23}O)_{3} | Do. do. --------------------------------------------------------------------- Myristin | C_{3}H_{5}(O.C_{14}H_{27}O)_{3} | Nutmeg butter --------------------------------------------------------------------- Palmitin | C_{3}H_{5}(O.C_{16}H_{31}O)_{3} | Palm oil, lard --------------------------------------------------------------------- Stearin | C_{3}H_{5}(O.C_{18}H_{35}O)_{3} | Tallow, lard, | | cacao butter --------------------------------------------------------------------- Olein | C_{3}H_{5}(O.C_{18}H_{33}O)_{3} | Olive and | | almond oils --------------------------------------------------------------------- Ricinolein | C_{3}H_{5}(O.C_{18}H_{33}O_{2})_{3} | Castor oil --------------------------------------------------------------------- --------------------------------------------------------------------- Glyceride. | Melting | Refractive | Saponification | Point, °C. | Index at 60° C. | Equivalent. --------------------------------------------------------------------- Butyrin | Liquid at -60 | 1.42015 | 100.7 --------------------------------------------------------------------- Isovalerin | ... | ... | 114.7 --------------------------------------------------------------------- Caproin | -25 | 1.42715 | 128.7 --------------------------------------------------------------------- Caprylin | -8.3 | 1.43316 | 156.7 --------------------------------------------------------------------- Caprin | 31.1 | 1.43697 | 184.7 --------------------------------------------------------------------- Laurin | 45 | 1.44039 | 212.7 --------------------------------------------------------------------- Myristin | 56.5 | 1.44285 | 240.7 --------------------------------------------------------------------- Palmitin | 63-64 | ... | 268.7 --------------------------------------------------------------------- Stearin | 71.6 | ... | 296.7 --------------------------------------------------------------------- Olein | Solidifies at -6 | ... | 294.7 --------------------------------------------------------------------- Ricinolein | ... | ... | 310.7 --------------------------------------------------------------------- Of the above the most important from a soap-maker's point of view are stearin, palmitin, olein and laurin, as these predominate in the fats and oils generally used in that industry. The presence of stearin and palmitin, which are solid at the ordinary temperature, gives firmness to a fat; the greater the percentage present, the harder the fat and the higher will be the melting point, hence tallows and palm oils are solid, firm fats. Where olein, which is liquid, is the chief constituent, we have softer fats, such as lard, and liquid oils, as almond, olive and cotton-seed. _Stearin_ (Tristearin) can be prepared from tallow by crystallisation from a solution in ether, forming small crystals which have a bright pearly lustre. The melting point of stearin appears to undergo changes and suggests the existence of distinct modifications. When heated to 55° C. stearin liquefies; with increase of temperature it becomes solid, and again becomes liquid at 71.6° C. If this liquid be further heated to 76° C., and allowed to cool, it will not solidify until 55° C. is reached, but if the liquid at 71.6° C. be allowed to cool, solidification will occur at 70° C. _Palmitin_ (Tripalmitin) may be obtained by heating together palmitic acid and glycerol, repeatedly boiling the resulting product with strong alcohol, and allowing it to crystallise. Palmitin exists in scales, which have a peculiar pearly appearance, and are greasy to the touch. After melting and solidifying, palmitin shows no crystalline fracture; when heated to 46° C. it melts to a liquid which becomes solid on further heating, again liquefying when 61.7° C. is reached, and becoming cloudy, with separation of crystalline particles. At 63° C. it is quite clear, and this temperature is taken as the true melting point. It has been suggested that the different changes at the temperatures mentioned are due to varying manipulation, such as rate at which the temperature is raised, and the initial temperature of the mass when previously cool. _Olein_ (Triolein) is an odourless, colourless, tasteless oil, which rapidly absorbs oxygen and becomes rancid. It has been prepared synthetically by heating glycerol and oleic acid together, and may be obtained by submitting olive oil to a low temperature for several days, when the liquid portion may be further deprived of any traces of stearin and palmitin by dissolving in alcohol. Olein may be distilled _in vacuo_ without decomposition taking place. _Laurin_ (Trilaurin) may be prepared synthetically from glycerol and lauric acid. It crystallises in needles, melting at 45°-46° C., which are readily soluble in ether, but only slightly so in cold absolute alcohol. Scheij gives its specific gravity, _d_60°/4° = 0.8944. Laurin is the chief constituent of palm-kernel oil, and also one of the principal components of cocoa-nut oil. _Fatty Acids._--When a fat or oil is saponified with soda or potash, the resulting soap dissolved in hot water, and sufficient dilute sulphuric acid added to decompose the soap, an oily layer gradually rises to the surface of the liquid, which, after clarifying by warming and washing free from mineral acid, is soluble in alcohol and reddens blue litmus paper. This oily layer consists of the "fatty acids" or rather those insoluble in water, acids like acetic, propionic, butyric, caproic, caprylic and capric, which are all more or less readily soluble in water, remaining for the most part dissolved in the aqueous portion. All the acids naturally present in oils and fats, whether free or combined, are monobasic in character, that is to say, contain only one carboxyl--CO.OH group. The more important fatty acids may be classified according to their chemical constitution into five homologous series, having the general formulæ:-- I. Stearic series C_{n}H_{2n+1}COOH II. Oleic series C_{n}H_{2n-1}COOH III. Linolic series C_{n}H_{2n-3}COOH IV. Linolenic series C_{n}H_{2n-5}COOH V. Ricinoleic series C_{n}H_{2n-7}COOH I. _Stearic Series._--The principal acids of this series, together with their melting points and chief sources, are given in the following table:-- ------------------------------------------------------------------------------- Acid. | Formula. | Melting | Found in | | Point, | | | °C. | ------------------------------------------------------------------------------- Acetic | CH_{3}COOH | 17 | Macassar oil. ------------------------------------------------------------------------------ Butyric | C_{3}H_{7}COOH | ... | Butter, Macassar oil. ------------------------------------------------------------------------------ Isovaleric | C_{4}H_{9}COOH | ... | Porpoise and dolphin oils. ------------------------------------------------------------------------------ Caproic | C_{5}H_{11}COOH | ... | Butter, cocoa-nut oil. ------------------------------------------------------------------------------ Caprylic | C_{7}H_{15}COOH | 15 | Butter, cocoa-nut oil, | | | Limburg cheese. ------------------------------------------------------------------------------ Capric | C_{9}H_{19}COOH | 30 | Butter, cocoa-nut oil. ------------------------------------------------------------------------------ Lauric | C_{11}H_{23}COOH | 44 | Cocoa-nut oil, palm-kernel oil. ------------------------------------------------------------------------------ Ficocerylic | C_{12}H_{25}COOH | ... | Pisang wax. ------------------------------------------------------------------------------ Myristic | C_{13}H_{27}COOH | 54 | Nutmeg butter, liver fat, | | | cocoa-nut oil, dika fat, | | | croton oil. ------------------------------------------------------------------------------ Palmitic | C_{15}H_{31}COOH | 62.5 | Palm oil, most animal fats. ------------------------------------------------------------------------------ Daturic | C_{16}H_{33}COOH | | Oil of Datura Stramonium. ------------------------------------------------------------------------------ Stearic | C_{17}H_{35}COOH | 69 | Tallow, lard, most solid | | | animal fats. ------------------------------------------------------------------------------ Arachidic | C_{19}H_{39}COOH | 75 | Arachis or earth-nut oil, | | | rape and mustard-seed oils. ------------------------------------------------------------------------------ Behenic | C_{21}H_{43}COOH | ... | Ben oil, black mustard-seed | | | oil, rape oil. ------------------------------------------------------------------------------ Lignoceric | C_{23}H_{47}COOH | 80.5 | Arachis oil. ------------------------------------------------------------------------------ Carnaubic | C_{23}H_{47}COOH | ... | Carnauba wax. ------------------------------------------------------------------------------ Pisangcerylic | C_{23}H_{47}COOH | ... | Pisang wax. ------------------------------------------------------------------------------ Hyænic | C_{24}H_{49}COOH | ... | Hyæna fat. ------------------------------------------------------------------------------ Cerotic | C_{25}H_{51}COOH | 78 | Beeswax, China wax, spermaceti. ------------------------------------------------------------------------------ Melissic | C_{29}H_{59}COOH | 89 | Beeswax. ------------------------------------------------------------------------------ Psyllostearylic| C_{32}H_{65}COOH | ... | Psylla wax. ------------------------------------------------------------------------------ Theobromic | C_{63}H_{127}COOH | ... | Cacao butter ------------------------------------------------------------------------------ Medullic and margaric acids, which were formerly included in this series, have now been shown to consist of mixtures of stearic and palmitic, and stearic palmitic and oleic acids respectively. The acids of this group are saturated compounds, and will not combine directly with iodine or bromine. The two first are liquid at ordinary temperatures, distil without decomposition, and are miscible with water in all proportions; the next four are more or less soluble in water and distil unchanged in the presence of water, as does also lauric acid, which is almost insoluble in cold water, and only slightly dissolved by boiling water. The higher acids of the series are solid, and are completely insoluble in water. All these acids are soluble in warm alcohol, and on being heated with solid caustic alkali undergo no change. II. _Oleic Series:_-- -------------------------------------------------------------------------- Acid. | Formula. | Melting | Found in | | Point, | | | °C. | -------------------------------------------------------------------------- Tiglic | C_{4}H_{7}COOH | 64.5 | Croton oil. -------------------------------------------------------------------------- Moringic | C_{14}H_{27}COOH | 0 | Ben oil. -------------------------------------------------------------------------- Physetoleic | C_{15}H_{29}COOH | 30 | Sperm oil. -------------------------------------------------------------------------- Hypogæic | C_{15}H_{29}COOH | 33 | Arachis and maize oils. -------------------------------------------------------------------------- Oleic | C_{17}H_{33}COOH | 14 | Most oils and fats. -------------------------------------------------------------------------- Rapic | C_{17}H_{33}COOH | ... | Rape oil. -------------------------------------------------------------------------- Doeglic | C_{18}H_{35}COOH | ... | Bottle-nose oil. -------------------------------------------------------------------------- Erucic | C_{21}H_{41}COOH | 34 | Mustard oils, marine animal | | | oils, rape oil. -------------------------------------------------------------------------- The unsaturated nature of these acids renders their behaviour with various reagents entirely different from that of the preceding series. Thus, they readily combine with bromine or iodine to form addition compounds, and the lower members of the series are at once reduced, on treatment with sodium amalgam in alkaline solution, to the corresponding saturated acids of Series I. Unfortunately, this reaction does not apply to the higher acids such as oleic acid, but as the conversion of the latter into solid acids is a matter of some technical importance from the point of view of the candle-maker, a number of attempts have been made to effect this by other methods. De Wilde and Reychler have shown that by heating oleic acid with 1 per cent. of iodine in autoclaves up to 270°-280° C., about 70 per cent. is converted into stearic acid, and Zürer has devised (German Patent 62,407) a process whereby the oleic acid is first converted by the action of chlorine into the dichloride, which is then reduced with nascent hydrogen. More recently Norman has secured a patent (English Patent 1,515, 1903) for the conversion of unsaturated fatty acids of Series II. into the saturated compounds of Series I., by reduction with hydrogen or water-gas in the presence of finely divided nickel, cobalt or iron. It is claimed that by this method oleic acid is completely transformed into stearic acid, and that the melting point of tallow fatty acids is raised thereby about 12° C. Another method which has been proposed is to run the liquid olein over a series of electrically charged plates, which effects its reduction to stearin. Stearic acid is also formed by treating oleic acid with fuming hydriodic acid in the presence of phosphorus, while other solid acids are obtained by the action of sulphuric acid or zinc chloride on oleic acid. Acids of Series II. may also be converted into saturated acids by heating to 300°C. with solid caustic potash, which decomposes them into acids of the stearic series with liberation of hydrogen. This reaction, with oleic acid, for example, is generally represented by the equation-- C_{18}H_{34}O_{2} + 2KOH = KC_{2}H_{3}O_{2} + KC_{16}H_{31}O_{2} + H_{2}, though it must be really more complex than this indicates, for, as Edmed has pointed out, oxalic acid is also formed in considerable quantity. The process on a commercial scale has now been abandoned. One of the most important properties of this group of acids is the formation of isomeric acids of higher melting point on treatment with nitrous acid, generally termed the _elaidin reaction_. Oleic acid, for example, acted upon by nitrous acid, yields elaidic acid, melting at 45°, and erucic acid gives brassic acid, melting at 60°C. This reaction also occurs with the neutral glycerides of these acids, olein being converted into elaidin, which melts at 32°C. The lead salts of the acids of this series are much more soluble in ether, and the lithium salts more soluble in alcohol than those of the stearic series, upon both of which properties processes have been based for the separation of the solid from the liquid fatty acids. III. _Linolic Series:_-- -------------------------------------------------------------------------- Acid. | Formula. | Melting | Found in | | Point, | | | °C. | -------------------------------------------------------------------------- Elæomargaric | C_{16}H_{29}COOH | ... | Chinese-wood oil. -------------------------------------------------------------------------- Elæostearic | C_{16}H_{29}COOH | 71 | Chinese-wood oil. -------------------------------------------------------------------------- Linolic | C_{17}H_{31}COOH | Fluid | Linseed, cotton-seed and | | | maize oils. -------------------------------------------------------------------------- Tariric | C_{17}H_{31}COOH | 50.5 | Tariri-seed oil. -------------------------------------------------------------------------- Telfairic | C_{17}H_{31}COOH | Fluid | Telfairia oil. -------------------------------------------------------------------------- These acids readily combine with bromine, iodine, or oxygen. They are unaffected by nitrous acid, and their lead salts are soluble in ether. IV. _Linolenic Series:_-- -------------------------------------------------------------------- Acid. | Formula. | Found in -------------------------------------------------------------------- Linolenic | C_{17}H_{29}COOH | Linseed oil. -------------------------------------------------------------------- Isolinolenic | C_{17}H_{29}COOH | Linseed oil. -------------------------------------------------------------------- Jecoric | C_{17}H_{29}COOH | Cod-liver and marine animal oils. -------------------------------------------------------------------- These acids are similar in properties to those of Class III., but combine with six atoms of bromine or iodine, whereas the latter combine with only four atoms. V. _Ricinoleic Series:_-- ----------------------------------------------------------- | | | | | | Acid. | Formula. | Melting | Found in | | | | Point, | | | | | °C. | | |------------|----------------------|---------|-------------| | | | | | | Ricinoleic | C_{17}H_{22}(OH)COOH | 4-5 | Castor oil. | ----------------------------------------------------------- This acid combines with two atoms of bromine or iodine, and is converted by nitrous acid into the isomeric ricinelaidic acid, which melts at 52°-53° C. Pure ricinoleic acid, obtained from castor oil, is optically active, its rotation being [alpha]_{d} +6° 25'. _Hydrolysis or Saponification of Oils and Fats._--The decomposition of a triglyceride, brought about by caustic alkalies in the formation of soap, though generally represented by the equation already given (pp. 6 and 7)-- C_{3}H_{5}(OR) + 3NaOH = C_{3}H_{5}(OH)_{3} + 3RONa, is not by any means such a simple reaction. In the first place, though in this equation no water appears, the presence of the latter is found to be indispensable for saponification to take place; in fact, the water must be regarded as actually decomposing the oil or fat, caustic soda or potash merely acting as a catalytic agent. Further, since in the glycerides there are three acid radicles to be separated from glycerol, their saponification can be supposed to take place in three successive stages, which are the converse of the formation of mono- and diglycerides in the synthesis of triglycerides from fatty acids and glycerine. Thus, the above equation may be regarded as a summary of the following three:-- _ _ | OR | OH (i.) C_{3}H_{5} | OR + NaOH = C_{3}H_{5} | OR + RONa |_OR |_OR _ _ | OH | OH (ii.) C_{3}H_{5} | OR + NaOH = C_{3}H_{5} | OR + RONa |_OR |_OH _ _ | OH | OH (iii.) C_{3}H_{5} | OR + NaOH = C_{3}H_{5} | OH + RONa |_OH |_OH Geitel and Lewkowitsch, who have studied this question from the physical and chemical point of view respectively, are of opinion that when an oil or fat is saponified, these three reactions do actually occur side by side, the soap-pan containing at the same time unsaponified triglyceride, diglyceride, monoglyceride, glycerol and soap. This theory is not accepted, however, by all investigators. Balbiano and Marcusson doubt the validity of Lewkowitsch's conclusions, and Fanto, experimenting on the saponification of olive oil with caustic potash, is unable to detect the intermediate formation of any mono- or diglyceride, and concludes that in homogeneous solution the saponification is practically quadrimolecular. Kreeman, on the other hand, from physico-chemical data, supports the view of Geitel and Lewkowitsch that saponification is bimolecular, and though the evidence seems to favour this theory, the matter cannot be regarded as yet definitely settled. Hydrolysis can be brought about by water alone, if sufficient time is allowed, but as the process is extremely slow, it is customary in practice to accelerate the reaction by the use of various methods, which include (i.) the application of heat or electricity, (ii.) action of enzymes, and (iii.) treatment with chemicals; the accelerating effect of the two latter methods is due to their emulsifying power. The most usual method adopted in the manufacture of soap is to hydrolyse the fat or oil by caustic soda or potash, the fatty acids liberated at the same time combining with the catalyst, _i.e._, soda or potash, to form soap. Hitherto the other processes of hydrolysis have been employed chiefly for the preparation of material for candles, for which purpose complete separation of the glycerol in the first hydrolysis is not essential, since the fatty matter is usually subjected to a second treatment with sulphuric acid to increase the proportion of solid fatty acids. The colour of the resulting fatty acids is also of no importance, as they are always subjected to distillation. During the last few years, however, there has been a growing attempt to first separate the glycerol from the fatty acids, and then convert the latter into soap by treatment with the carbonates of soda or potash, which are of course considerably cheaper than the caustic alkalies, but cannot be used in the actual saponification of a neutral fat. The two processes chiefly used for this purpose are those in which the reaction is brought about by enzymes or by Twitchell's reagent. I. _Application of Heat or Electricity._--Up to temperatures of 150° C. the effect of water on oils and fats is very slight, but by passing superheated steam through fatty matter heated to 200°-300° C. the neutral glycerides are completely decomposed into glycerol and fatty acids according to the equation-- C_{3}H_{5}(OR)_{3} + 3H.OH = C_{3}H_{5}(OH)_{3} + 3ROH. The fatty acids and glycerol formed distil over with the excess of steam, and by arranging a series of condensers, the former, which condense first, are obtained almost alone in the earlier ones, and an aqueous solution of glycerine in the later ones. This method of preparation of fatty acids is extensively used in France for the production of stearine for candle-manufacture, but the resulting product is liable to be dark coloured, and to yield a dark soap. To expose the acids to heat for a minimum of time, and so prevent discoloration, Mannig has patented (Germ. Pat. 160,111) a process whereby steam under a pressure of 8 to 10 atmospheres is projected against a baffle plate mounted in a closed vessel, where it mixes with the fat or oil in the form of a spray, the rate of hydrolysis being thereby, it is claimed, much increased. Simpson (Fr. Pat. 364,587) has attempted to accelerate further the decomposition by subjecting oils or fats to the simultaneous action of heat and electricity. Superheated steam is passed into the oil, in which are immersed the two electrodes connected with a dynamo or battery, the temperature not being allowed to exceed 270° C. II. _Action of Enzymes._--It was discovered by Muntz in 1871 (_Annales de Chemie_, xxii.) that during germination of castor seeds a quantity of fatty acid was developed in the seeds, which he suggested might be due to the decomposition of the oil by the embryo acting as a ferment. Schutzenberger in 1876 showed that when castor seeds are steeped in water, fatty acids and glycerol are liberated, and attributed this to the hydrolytic action of an enzyme present in the seeds. No evidence of the existence of such a ferment was adduced, however, till 1890, when Green (_Roy. Soc. Proc._, 48, 370) definitely proved the presence in the seeds of a ferment capable of splitting up the oil into fatty acid and glycerol. The first experimenters to suggest any industrial application of this enzymic hydrolysis were Connstein, Hoyer and Wartenburg, who (_Berichte_, 1902, 35, pp. 3988-4006) published the results of a lengthy investigation of the whole subject. They found that tallow, cotton-seed, palm, olive, almond, and many other oils, were readily hydrolysed by the castor-seed ferment in the presence of dilute acid, but that cocoa-nut and palm-kernel oils only decomposed with difficulty. The presence of acidity is essential for the hydrolysis to take place, the most suitable strength being one-tenth normal, and the degree of hydrolysis is proportional to the quantity of ferment present. Sulphuric, phosphoric, acetic or butyric acids, or sodium bisulphate, may be used without much influence on the result. Butyric acid is stated to be the best, but in practice is too expensive, and acetic acid is usually adopted. The emulsified mixture should be allowed to stand for twenty-four hours, and the temperature should not exceed 40° C.; at 50° C. the action is weakened, and at 100° C. ceases altogether. Several investigators have since examined the hydrolysing power of various other seeds, notably Braun and Behrendt (_Berichte_, 1903, 36, 1142-1145, 1900-1901, and 3003-3005), who, in addition to confirming Connstein, Hoyer and Wartenburg's work with castor seeds, have made similar experiments with jequirity seeds (_Abrus peccatorius_) containing the enzyme abrin, emulsin from crushed almonds, the leaves of _Arctostaphylos Uva Ursi_, containing the glucoside arbutin, myrosin from black mustard-seed, gold lac (_Cheirantus cheiri_) and crotin from croton seeds. Jequirity seeds were found to have a stronger decomposing action on lanoline and carnauba wax than the castor seed, but only caused decomposition of castor oil after the initial acidity was first neutralised with alkali. Neither emulsin, arbutin nor crotin have any marked hydrolytic action on castor oil, but myrosin is about half as active as castor seeds, except in the presence of potassium myronate, when no decomposition occurs. S. Fokin (_J. russ. phys. chem. Ges._, 35, 831-835, and _Chem. Rev. Fett. u. Harz. Ind._, 1904, 30 _et seq._) has examined the hydrolytic action of a large number of Russian seeds, belonging to some thirty different families, but although more than half of these brought about the hydrolysis of over 10 per cent. of fat, he considers that in only two cases, _viz._, the seeds of _Chelidonium majus_ and _Linaria vulgaris_, is the action due to enzymes, these being the only two seeds for which the yield of fatty acids is proportional to the amount of seed employed, while in many instances hydrolysis was not produced when the seeds were old. The seeds of _Chelidonium majus_ were found to have as great, and possibly greater, enzymic activity than castor seeds, but those of _Linaria_ are much weaker, twenty to thirty parts having only the same lipolytic activity as four to five parts of castor seeds. The high percentage of free acids found in rice oil has led C. A. Brown, jun. (_Journ. Amer. Chem. Soc._, 1903, 25, 948-954), to examine the rice bran, which proves to have considerable enzymic activity, and rapidly effects the hydrolysis of glycerides. The process for the utilisation of enzymic hydrolysis in the separation of fatty acids from glycerine on the industrial scale, as originally devised by Connstein and his collaborators, consisted in rubbing a quantity of the coarsely crushed castor seeds with part of the oil or fat, then adding the rest of the oil, together with acidified water (N/10 acetic acid). The quantities employed were 6-1/2 parts of decorticated castor beans for every 100 parts of oil or fat, and 50 to 60 parts of acetic acid. After stirring until an emulsion is formed, the mixture is allowed to stand for twenty-four hours, during which hydrolysis takes place. The temperature is then raised to 70°-80° C., which destroys the enzyme, and a 25 per cent. solution of sulphuric acid, equal in amount to one-fiftieth of the total quantity of fat originally taken, added to promote separation of the fatty acids. In this way three layers are formed, the one at the top consisting of the clear fatty acids, the middle one an emulsion containing portions of the seeds, fatty acids and glycerine, and the bottom one consisting of the aqueous glycerine. The intermediate layer is difficult to treat satisfactorily; it is generally washed twice with water, the washings being added to glycerine water, and the fatty mixture saponified and the resultant soap utilised. The process has been the subject of a considerable amount of investigation, numerous attempts having been made to actually separate the active fat-splitting constituent of the seeds, or to obtain it in a purer and more concentrated form than is furnished by the seeds themselves. Nicloux (_Comptes Rendus_, 1904, 1112, and _Roy. Soc. Proc._, 1906, 77 B, 454) has shown that the hydrolytic activity of castor seeds is due entirely to the cytoplasm, which it is possible to separate by mechanical means from the aleurone grains and all other cellular matter. This active substance, which he terms "lipaseidine," is considered to be not an enzyme, though it acts as such, following the ordinary laws of enzyme action; its activity is destroyed by contact with water in the absence of oil. This observer has patented (Eng. Pat. 8,304, 1904) the preparation of an "extract" by triturating crushed castor or other seeds with castor oil, filtering the oily extract, and subjecting it to centrifugal force. The deposit consists of aleurone and the active enzymic substance, together with about 80 per cent. of oil, and one part of it will effect nearly complete hydrolysis of 100 parts of oil in twenty-four hours. In a subsequent addition to this patent, the active agent is separated from the aleurone by extraction with benzene and centrifugal force. By the use of such an extract, the quantity of albuminoids brought into contact with the fat is reduced to about 10 per cent. of that in the original seeds, and the middle layer between the glycerine solution and fatty acids is smaller and can be saponified directly for the production of curd soap, while the glycerine solution also is purer. In a further patent Nicloux (Fr. Pat. 349,213, 1904) states that the use of an acid medium is unnecessary, and claims that even better results are obtained by employing a neutral solution of calcium sulphate containing a small amount of magnesium sulphate, the proportion of salts not exceeding 0.5 per cent. of the fat, while in yet another patent, jointly with Urbain (Fr. Pat. 349,942, 1904), it is claimed that the process is accelerated by the removal of acids from the oil or fat to be treated, which may be accomplished by either washing first with acidulated water, then with pure water, or preferably by neutralising with carbonate of soda and removing the resulting soap. Lombard (Fr. Pat. 350,179, 1904) claims that acids act as stimulating agents in the enzymic hydrolysis of oils, and further that a simple method of obtaining the active product is to triturate oil cake with its own weight of water, allow the mixture to undergo spontaneous proteolytic hydrolysis at 40° C. for eight days, and then filter, the filtrate obtained being used in place of water in the enzymic process. Hoyer, who has made a large number of experiments in the attempt to isolate the lipolytic substance from castor seeds, has obtained a product of great activity, which he terms "ferment-oil," by extracting the crushed seeds with a solvent for oils. The Verein Chem. Werke have extended their original patent (addition dated 11th December, 1905, to Fr. Pat. 328,101, Oct., 1902), which now covers the use of vegetable ferments in the presence of water and manganese sulphate or other metallic salt. It is further stated that acetic acid may be added at the beginning of the operation, or use may be made of that formed during the process, though in the latter case hydrolysis is somewhat slower. Experiments have been carried out by Lewkowitsch and Macleod (_Journ. Soc. Chem. Ind._, 1903, 68, and _Proc. Roy. Soc._, 1903, 31) with ferments derived from animal sources, _viz._, lipase from pig's liver, and steapsin from the pig or ox pancreas. The former, although it has been shown by Kastle and Loevenhart (_Amer. Chem. Journ._, 1900, 49) to readily hydrolyse ethyl butyrate, is found to have very little fat-splitting power, but with steapsin more favourable results have been obtained, though the yield of fatty acids in this case is considerably inferior to that given by castor seeds. With cotton-seed oil, 83-86 per cent. of fatty acids were liberated as a maximum after fifty-six days, but with lard only 46 per cent. were produced in the same time. Addition of dilute acid or alkali appeared to exert no influence on the decomposition of the cotton-seed oil, but in the case of the lard, dilute alkali seemed at first to promote hydrolysis, though afterwards to retard it. Fokin (_Chem. Rev. Fett. u. Harz. Ind._, 1904, 118-120 _et seq._) has attempted to utilise the pancreatic juice on a technical scale, but the process proved too slow and too costly to have any practical use. _Rancidity._--The hydrolysing power of enzymes throws a good deal of light on the development of rancidity in oils and fats, which is now generally regarded as due to the oxidation by air in the presence of light and moisture of the free fatty acids contained by the oil or fat. It has long been known that whilst recently rendered animal fats are comparatively free from acidity, freshly prepared vegetable oils invariably contain small quantities of free fatty acid, and there can be no doubt that this must be attributed to the action of enzymes contained in the seeds or fruit from which the oils are expressed, hence the necessity for separating oils and fats from adhering albuminous matters as quickly as possible. _Decomposition of Fats by Bacteria._--Though this subject is not of any practical interest in the preparation of fatty acids for soap-making, it may be mentioned, in passing, that some bacteria readily hydrolyse fats. Schriber (_Arch. f. Hyg._, 41, 328-347) has shown that in the presence of air many bacteria promote hydrolysis, under favourable conditions as to temperature and access of oxygen, the process going beyond the simple splitting up into fatty acid and glycerol, carbon dioxide and water being formed. Under anærobic conditions, however, only a slight primary hydrolysis was found to take place, though according to Rideal (_Journ. Soc. Chem. Ind._, 1903, 69) there is a distinct increase in the amount of free fatty acids in a sewage after passage through a septic tank. Experiments have also been made on this subject by Rahn (_Centralb. Bakteriol_, 1905, 422), who finds that _Penicillium glaucum_ and other penicillia have considerable action on fats, attacking the glycerol and lower fatty acids, though not oleic acid. A motile bacillus, producing a green fluorescent colouring matter, but not identified, had a marked hydrolytic action and decomposed oleic acid. The name "lipobacter" has been proposed by De Kruyff for bacteria which hydrolyse fats. III. _Use of Chemical Reagents._--Among the chief accelerators employed in the hydrolysis of oils are sulphuric acid and Twitchell's reagent (benzene- or naphthalene-stearosulphonic acid), while experiments have also been made with hydrochloric acid (_Journ. Soc. Chem. Ind._, 1903, 67) with fairly satisfactory results, and the use of sulphurous acid, or an alkaline bisulphite as catalyst, has been patented in Germany. To this class belong also the bases, lime, magnesia, zinc oxide, ammonia, soda and potash, though these latter substances differ from the former in that they subsequently combine with the fatty acids liberated to form soaps. _Sulphuric Acid._--The hydrolysing action of concentrated sulphuric acid upon oils and fats has been known since the latter part of the eighteenth century, but was not applied on a practical scale till 1840 when Gwynne patented a process in which sulphuric acid was used to liberate the fatty acids, the latter being subsequently purified by steam distillation. By this method, sulpho-compounds of the glyceride are first formed, which readily emulsify with water, and, on treatment with steam, liberate fatty acids, the glycerol remaining partly in the form of glycero-sulphuric acid. The process has been investigated by Fremy, Geitel, and more recently by Lewkowitsch (_J. Soc. of Arts_, "Cantor Lectures," 1904, 795 _et seq._), who has conducted a series of experiments on the hydrolysis of tallow with 4 per cent. of sulphuric acid of varying strengths, containing from 58 to 90 per cent. sulphuric acid, H_{2}SO_{4}. Acid of 60 per cent. or less appears to be practically useless as a hydrolysing agent, while with 70 per cent. acid only 47.7 per cent. fatty acids were developed after twenty-two hours' steaming, and with 80 and 85 per cent. acid, the maximum of 89.9 per cent. of fatty acids was only reached after fourteen and fifteen hours' steaming respectively. Using 98 per cent. acid, 93 per cent. of fatty acids were obtained after nine hours' steaming, and after another seven hours, only 0.6 per cent. more fatty acids were produced. Further experiments have shown that dilute sulphuric acid has also scarcely any action on cotton-seed, whale, and rape oils. According to Lant Carpenter, some 75 per cent. of solid fatty acids may be obtained from tallow by the sulphuric acid process, owing to the conversion of a considerable quantity of oleic acid into isoleic acid (_vide_ p. 12), but in the process a considerable proportion of black pitch is obtained. C. Dreymann has recently patented (Eng. Pat. 10,466, 1904) two processes whereby the production of any large amount of hydrocarbons is obviated. In the one case, after saponification with sulphuric acid, the liberated fatty acids are washed with water and treated with an oxide, carbonate, or other acid-fixing body, _e.g._, sodium carbonate, prior to distillation. In this way the distillate is much clearer than by the ordinary process, and is almost odourless, while the amount of unsaponifiable matter is only about 1.2 per cent. The second method claimed consists in the conversion of the fatty acids into their methyl esters by treatment with methyl alcohol and hydrochloric acid gas, and purification of the esters by steam distillation, the pure esters being subsequently decomposed with superheated steam, in an autoclave, with or without the addition of an oxide, _e.g._, 0.1 per cent. zinc oxide, to facilitate their decomposition. _Twitchell's Reagent._--In Twitchell's process use is made of the important discovery that aqueous solutions of fatty aromatic sulphuric acids, such as benzene- or naphthalene-stearosulphonic acid, readily dissolve fatty bodies, thereby facilitating their dissociation into fatty acids and glycerol. These compounds are stable at 100° C., and are prepared by treating a mixture of benzene or naphthalene and oleic acid with an excess of sulphuric acid, the following reaction taking place:-- C_{6}H_{6} + C_{18}H_{34}O_{2} + H_{2}SO_{4} = C_{6}H_{4}(SO_{3}H)C_{18}H_{35}O + H_{2}O. On boiling the resultant product with water two layers separate, the lower one consisting of a clear aqueous solution of sulphuric acid and whatever benzene-sulphonic acid has been formed, while the upper layer, which is a viscous oil, contains the benzene-stearosulphonic acid. This, after washing first with hydrochloric acid and then rapidly with petroleum ether, and drying at 100° C. is then ready for use; the addition of a small quantity of this reagent to a mixture of fat (previously purified) and water, agitated by boiling with open steam, effects almost complete separation of the fatty acid from glycerol. The process is generally carried out in two wooden vats, covered with closely fitting lids, furnished with the necessary draw-off cocks, the first vat containing a lead coil and the other a brass steam coil. In the first vat, the fat or oil is prepared by boiling with 1 or 2 per cent. of sulphuric acid (141° Tw. or 60° B.) for one or two hours and allowed to rest, preferably overnight; by this treatment the fat is deprived of any dirt, lime or other impurity present. After withdrawing the acid liquor, the fat or oil is transferred to the other vat, where it is mixed with one-fifth of its bulk of water (condensed or distilled), and open steam applied. As soon as boiling takes place, the requisite amount of reagent is washed into the vat by the aid of a little hot water through a glass funnel, and the whole is boiled continuously for twelve or even twenty-four hours, until the free fatty acids amount to 85-90 per cent. The amount of reagent used varies with the grade of material, the smaller the amount consistent with efficient results, the better the colour of the finished product; with good material, from 1/2 to 3/4 per cent. is sufficient, but for materials of lower grade proportionately more up to 2 per cent. is required. The reaction appears to proceed better with materials containing a fair quantity of free acidity. When the process has proceeded sufficiently far, the boiling is stopped and free steam allowed to fill the vat to obviate any discoloration of the fatty acids by contact with the air, whilst the contents of the vat settle. The settled glycerine water, which should amount in bulk to 50 or 60 per cent. of the fatty matter taken, and have a density of 7-1/2° Tw. (5° B.), is removed to a receptacle for subsequent neutralisation with milk of lime, and, after the separation of sludge, is ready for concentration. The fatty acids remaining in the vat are boiled with a small quantity (0.05 per cent., or 1/10 of the Twitchell reagent requisite) of commercial barium carbonate, previously mixed with a little water; the boiling may be prolonged twenty or thirty minutes, and at the end of that period the contents of the vat are allowed to rest; the water separated should be neutral to methyl-orange indicator. It is claimed that fatty acids so treated are not affected by the air, and may be stored in wooden packages. _Hydrochloric Acid._--Lewkowitsch (_Journ. Soc. Chem. Ind._, 1903, 67) has carried out a number of experiments on the accelerating influence of hydrochloric acid upon the hydrolysis of oils and fats, which show that acid of a specific gravity of 1.16 has a very marked effect on most oils, cocoa-nut, cotton-seed, whale and rape oils, tallow and lard being broken up into fatty acid and glycerol to the extent of some 82-96 per cent. after boiling 100 grams of the oil or fat with 100 c.c. of acid for twenty-four hours. The maximum amount of hydrolysis was attained with cocoa-nut oil, probably owing to its large proportion of the glycerides of volatile fatty acids. Castor oil is abnormal in only undergoing about 20 per cent. hydrolysis, but this is attributed to the different constitution of its fatty acids, and the ready formation of polymerisation products. Experiments were also made as to whether the addition of other catalytic agents aided the action of the hydrochloric acid; mercury, copper sulphate, mercury oxide, zinc, zinc dust, aluminium chloride, nitrobenzene and aniline being tried, in the proportion of 1 per cent. The experiments were made on neutral lard and lard containing 5 per cent. of free fatty acids, but in no case was any appreciable effect produced. So far this process has not been adopted on the practical scale, its chief drawback being the length of time required for saponification. Undoubtedly the hydrolysis would be greatly facilitated if the oil and acid could be made to form a satisfactory emulsion, but although saponin has been tried for the purpose, no means of attaining this object has yet been devised. _Sulphurous Acid or Bisulphite._--The use of these substances has been patented by Stein, Berge and De Roubaix (Germ. Pat. 61,329), the fat being heated in contact with the reagent for about nine hours at 175°-180° C. under a pressure of some 18 atmospheres, but the process does not appear to be of any considerable importance. _Lime._--The use of lime for the saponification of oils and fats was first adopted on the technical scale for the production of candle-making material, by De Milly in 1831. The insoluble lime soap formed is decomposed by sulphuric acid, and the fatty acids steam distilled. The amount of lime theoretically necessary to hydrolyse a given quantity of a triglyceride, ignoring for the moment any catalytic influence, can be readily calculated; thus with stearin the reaction may be represented by the equation:-- CH_{2}OOC_{18}H_{35} CH_{2}OH | | 2CHOOC_{18}H_{35} + 3Ca(OH)_{2} = 3Ca(OOC_{18}H_{35})_{2} + 2CHOH | | CH_{2}OOC_{18}H_{35} CH_{2}OH stearin milk of lime calcium stearate glycerol In this instance, since the molecular weight of stearin is 890 and that of milk of lime is 74, it is at once apparent that for every 1,780 parts of stearin, 222 parts of milk of lime or 168 parts of quick-lime, CaO, would be required. It is found in practice, however, that an excess of 3-5 per cent. above the theoretical quantity of lime is necessary to complete the hydrolysis of a fat when carried on in an open vessel at 100°-105° C., but that if the saponification be conducted under pressure in autoclaves the amount of lime necessary to secure almost perfect hydrolysis is reduced to 2-3 per cent. on the fat, the treatment of fats with 3 per cent. of lime under a pressure of 10 atmospheres producing a yield of 95 per cent. of fatty acids in seven hours. The lower the pressure in the autoclave, the lighter will be the colour of the resultant fatty acids. _Magnesia._--It has been proposed to substitute magnesia for lime in the process of saponification under pressure, but comparative experiments with lime and magnesia, using 3 per cent. of lime and 2.7 per cent. of magnesia (_Journ. Soc. Chem. Ind._, xii., 163), show that saponification by means of magnesia is less complete than with lime, and, moreover, the reaction requires a higher temperature and therefore tends to darken the product. _Zinc Oxide._--The use of zinc oxide as accelerating agent has been suggested by two or three observers. Poullain and Michaud, in 1882, were granted a patent for this process, the quantity of zinc oxide recommended to be added to the oil or fat being 0.2 to 0.5 per cent. Rost, in 1903, obtained a French patent for the saponification of oils and fats by steam under pressure in the presence of finely divided metals or metallic oxides, and specially mentions zinc oxide for the purpose. It has also been proposed to use zinc oxide in conjunction with lime in the autoclave to obviate to some extent the discoloration of the fatty acids. Other catalytic agents have been recommended from time to time, including strontianite, lead oxide, caustic baryta, aluminium hydrate, but none of these is of any practical importance. _Soda and Potash._--Unlike the preceding bases, the soaps formed by soda and potash are soluble in water, and constitute the soap of commerce. These reagents are always used in sufficient quantity to combine with the whole of the fatty acids contained in an oil or fat, though doubtless, by the use of considerably smaller quantities, under pressure, complete resolution of the fatty matter into fatty acids and glycerol could be accomplished. They are, by far, the most important saponifying agents from the point of view of the present work, and their practical use is fully described in Chapter V. CHAPTER III. RAW MATERIALS USED IN SOAP-MAKING. _Fats and Oils--Waste Fats--Fatty Acids--Less-known Oils and Fats of Limited Use--Various New Fats and Oils Suggested for Soap-making--Rosin--Alkali (Caustic and Carbonated)--Water--Salt--Soap-stock._ _Fats and Oils._--All animal and vegetable oils and fats intended for soap-making should be as free as possible from unsaponifiable matter, of a good colour and appearance, and in a sweet, fresh condition. The unsaponifiable matter naturally present as cholesterol, or phytosterol, ranges in the various oils and fats from 0.2 to 2.0 per cent. All oils and fats contain more or less free acidity; but excess of acidity, though it may be due to the decomposition of the glyceride, and does not always denote rancidity, is undesirable in soap-making material. Rancidity of fats and oils is entirely due to oxidation, in addition to free acid, aldehydes and ketones being formed, and it has been proposed to estimate rancidity by determining the amount of these latter produced. It is scarcely necessary to observe how very important it is that the sampling of fats and oils should be efficiently performed, so that the sample submitted to the chemist may be a fairly representative average of the parcel. In the following short description of the materials used, we give, under each heading, figures for typical samples of the qualities most suitable for soap-making. _Tallows._--Most of the imported tallow comes from America, Australia and New Zealand. South American mutton tallow is usually of good quality; South American beef tallow is possessed of a deep yellow colour and rather strong odour, but makes a bright soap of a good body and texture. North American tallows are, as a general rule, much paler in colour than those of South America, but do not compare with them in consistence. Most of the Australasian tallows are of very uniform quality and much in demand. Great Britain produces large quantities of tallow which comes into the market as town and country tallow, or home melt. Owing to the increasing demand for edible fat, much of the rough fat is carefully selected, rendered separately, and the product sold for margarine-making. Consequently the melted tallow for soap-making is of secondary importance to the tallow melter. The following are typical samples of tallow:-- _______________________________________________________________________ | | | | | | | | Acidity | | | | Saponification | (as Oleic | Titre, | | | Equivalent. | Acid) | °C. | | | | Per Cent. | | |_________________________________|________________|___________|________| | | | | | | Australian mutton | 285 | 0.85 | 45 | | Australian mutton | 284.4 | 0.48 | 48.3 | | Australian beef | 284.2 | 1.68 | 43.9 | | Australian beef | 283.6 | 0.85 | 42.6 | | Australian mixed | 285.1 | 3.52 | 44 | | Australian mixed | 284.6 | 1.89 | 43.5 | | South American mutton | 284.5 | 1.11 | 47 | | South American mutton | 285 | 0.90 | 47.4 | | South American beef | 284.7 | 0.81 | 45 | | South American beef | 284 | 0.94 | 44 | | North American mutton | 284.3 | 1.32 | 44 | | North American mutton | 85 | 2.18 | 43.2 | | North American beef, fine | 284.5 | 1.97 | 41.5 | | North American beef, good | 283.8 | 4.30 | 42 | | North American ordinary | 285.2 | 5.07 | 41.75 | | North American prime city | 286 | 1.01 | 41.2 | | Selected English mutton | 283.9 | 1.45 | 47 | | Selected English beef | 284.2 | 2.40 | 44 | | Home-rendered or country tallow | 284.6 | 5.1 | 43 | | Town tallow | 285.3 | 7.4 | 42.5 | |_________________________________|________________|___________|________| Tallow should absorb from 39 to 44 per cent. iodine. _Lard._--Lard is largely imported into this country from the United States of America. The following is a typical sample of American hog's fat offered for soap-making:-- ________________________________________________________ | | | | | | Saponification | Acidity | Titre, | Refractive | | Equivalent. | (as Oleic Acid) | °C. | Index | | | Per Cent. | | at 60° C. | |________________|_________________|________|____________| | | | | | | 286 | 0.5 | 37.5 | 1.4542 | |________________|_________________|________|____________| Lard should absorb 59 to 63 per cent. iodine. _Cocoa-nut Oil._--The best known qualities are Cochin and Ceylon oils, which are prepared in Cochin (Malabar) or the Philippine Islands and Ceylon respectively. The dried kernels of the cocoa-nut are exported to various ports in Europe, and the oil obtained comes on the market as Continental Coprah Oil, with the prefix of the particular country or port where it has been crushed, _e.g._, Belgian, French and Marseilles Coprah Oil. Coprah is also imported into England, and the oil expressed from it is termed English Pressed Coprah. The following are typical examples from bulk:-- _________________________________________________________________________ | | | | | | | | Saponification | Acidity | Titre, | Refractive | | | Equivalent. | (as Oleic Acid) | °C. | Index | | | | Per Cent. | | at 25° C. | |________________|________________|_________________|________|____________| | | | | | | | Cochin oil | 215.5 | 1.5 | 23.5 | 1.4540 | | Cochin oil | 214.3 | 2.6 | 22.1 | 1.4541 | | Ceylon oil | 214.6 | 5.47 | 23 | 1.4535 | | Ceylon oil | 216 | 3.95 | 22.75 | 1.4535 | | Belgian coprah | 214.2 | 1.65 | 23 | 1.4541 | | Belgian coprah | 215 | 2.60 | 22.1 | 1.4540 | | French coprah | 214.2 | 6.55 | 23 | 1.4535 | | French coprah | 214.8 | 7.42 | 22 | 1.4540 | | Pressed coprah | 215.8 | 7.45 | 22.2 | 1.4542 | | Pressed coprah | 216 | 9.41 | 22 | 1.4555 | |________________|________________|_________________|________|____________| Cocoa-nut oil should absorb 8.9 to 9.3 per cent. iodine. _Palm-nut Oil._--The kernels of the palm-tree fruit are exported from the west coast of Africa to Europe, and this oil obtained from them. Typical samples of English and Hamburg oils tested:-- _________________________________________________________ | | | | | | Saponification | Acidity | Titre, | Refractive | | Equivalent. | (as Oleic Acid) | °C. | Index | | | Per Cent. | | at 25° C. | |________________|_________________|________|____________| | | | | | | 225 | 4.4 | 24 | 1.4553 | | 227 | 7.7 | 23.8 | 1.4553 | |________________|_________________|________|____________| Palm-nut oil should absorb 10 to 13 per cent. iodine. _Olive Oil._--The olive is extensively grown in Southern Europe and in portions of Asia and Africa bordering the Mediterranean Sea. The fruit of this tree yields the oil. The free fatty acid content of olive oil varies very considerably. Very fine oils contain less than 1 per cent. acidity; commercial oils may be graded according to their free acidity, _e.g._, under 5 per cent., under 10 per cent., etc., and it entirely depends upon the desired price of the resultant soap as to what grade would be used. The following is a typical sample for use in the production of high-class toilet soap:-- _________________________________________________________ | | | | | | Saponification | Acidity | Titre, | Refractive | | Equivalent. | (as Oleic Acid) | °C. | Index | | | Per Cent. | | at 15° C. | |________________|_________________|________|____________| | | | | | | 288 | 1.8 | 21 | 1.4704 | |________________|_________________|________|____________| Olive oil should absorb 80 to 83 per cent. iodine. _Olive-kernel oil_, more correctly termed _Sulphur olive oil_. The amount of free fatty acids is always high and ranges from 40-70 per cent., and, of course, its glycerol content is proportionately variable. The free acidity increases very rapidly, and is, doubtless, due to the decomposition of the neutral oil by the action of hydrolytic ferment. A representative sample of a parcel tested:-- _______________________________________________ | | | | | Saponification | Acidity | Refractive | | Equivalent. | (as Oleic Acid) | Index | | | Per Cent. | at 20° C. | |________________|_________________|____________| | | | | | 298 | 40.96 | 1.4666 | |________________|_________________|____________| _Palm oil_ is produced from the fruit of palm trees, which abound along the west coast of Africa. Lagos is the best quality, whilst Camaroons, Bonny, Old Calabar and New Calabar oils are in good request for bleaching purposes. Analysis of typical samples of crude palm oil has given:-- _________________________________________________________ | | | | | | Saponification | Acidity | Titre, | Water and | | Equivalent. | (as Oleic Acid) | °C. | Impurities, | | | Per Cent. | | Per Cent. | |________________|_________________|________|_____________| | | | | | | 278 | 10.7 | 45 | 1.6 | | 280 | 31.2 | 44.5 | 2.8 | |________________|_________________|________|_____________| Palm oil should absorb 51 to 56 per cent. iodine. In the lower qualities we have examples of the result of hydrolytic decomposition by enzymes, the free acidity often amounting to 70 per cent. _Cotton-seed Oil._--This oil is expressed from the seeds separated from the "wool" of the various kinds of cotton tree largely cultivated in America and Egypt. In its crude state cotton-seed oil is a dark fluid containing mucilaginous and colouring matter, and is not applicable for soap-making. The following figures are representative of well-refined cotton-seed oils:-- _________________________________________________________________________ | | | | | | | Specific | Saponification | Acidity | Titre, | Refractive | | Gravity | Equivalent. | (as Oleic Acid) | °C. | Index | | at 15° C. | | Per Cent. | | at 20° C. | |___________|________________|_________________|________|____________| | | | | | | | 0.9229 | 290 | 0.24 | 33.6 | 1.4721 | | 0.924 | 299 | 0.39 | 35 | 1.4719 | |___________|________________|_________________|________|____________| Cotton-seed oil should absorb 104 to 110 per cent. iodine. _Cotton-seed Stearine._--The product obtained by pressing the deposit which separates on chilling refined cotton-seed oil. A typical sample tested:-- ___________________________________________ | | | | | Saponification | Acidity | Titre, | | Equivalent. | (as Oleic Acid) | °C. | | | Per Cent. | | |________________|_________________|________| | | | | | 285.1 | 0.05 | 38 | |________________|_________________|________| _Arachis Oil._--The earth-nut or ground-nut, from which arachis oil is obtained, is extensively cultivated in North America, India and Western Africa. Large quantities are exported to Marseilles where the oil is expressed. Arachis oil enters largely into the composition of Marseilles White Soaps. Representative samples of commercial and refined oils tested:-- ______________________________________________________________________ | | | | | | | | | Specific | Saponi- | Acidity | | Refractive | | | Gravity | fication | (as Oleic | Titre, | Index | | | at 15° C. | Equi- | Acid) | °C. | at 20° C. | | | | valent | Per Cent. | | | |____________|___________|___________|___________|________|____________| | | | | | | | | Commercial | 0.9184 | 298 | 2.6 | 28.6 | | | Refined | 0.9205 | 285 | 0.22 | 24.0 | 1.4712 | |____________|___________|___________|___________|________|____________| Arachis oil should absorb 90 to 98 per cent. iodine. _Maize Oil._--America (U.S.) produces very large quantities of maize oil. Typical samples of crude and refined oil gave these figures:-- ______________________________________________________________________ | | | | | | | | | Specific | Saponi- | Acidity | | Refractive | | | Gravity | fication | (as Oleic | Titre, | Index | | | at 15° C. | Equi- | Acid) | °C. | at 20° C. | | | | valent | Per Cent. | | | |____________|___________|___________|___________|________|____________| | | | | | | | | Crude | 0.9246 | 294 | 1.41 | 15 | | | Refined | 0.9248 | 294.1 | 0.40 | 17.2 | 1.4766 | |____________|___________|___________|___________|________|____________| Maize oil should absorb 120 to 128 per cent. iodine. _Sesame Oil._--Sesame oil is very largely pressed in Southern France from the seeds of the sesame plant which is cultivated in the Levant, India, Japan and Western Africa. A fairly representative sample of French expressed oil tested:-- ____________________________________________________________________ | | | | | | | Specific | Saponification | Acidity | Titre, | Refractive | | Gravity | Equivalent. | (as Oleic Acid) | °C. | Index | | at 15° C. | | Per Cent. | | at 20° C. | |___________|________________|_________________|________|____________| | | | | | | | 0.9227 | 295.2 | 1.84 | 22.8 | 1.4731 | |___________|________________|_________________|________|____________| Sesame oil should absorb 108 to 110 per cent. iodine. _Linseed Oil._--Russia, India, and Argentine Republic are the principal countries which extensively grow the flax plant, from the seeds of which linseed oil is pressed. It is used to a limited extent in soft-soap making. A good sample gave on analysis:-- ____________________________________________________________________ | | | | | | | Specific | Saponification | Acidity | Titre, | Refractive | | Gravity | Equivalent. | (as Oleic Acid) | °C. | Index | | at 15° C. | | Per Cent. | | at 15° C. | |___________|________________|_________________|________|____________| | | | | | | | 0.935 | 292 | 1.2 | 20 | 1.4840 | |___________|________________|_________________|________|____________| Linseed oil should absorb 170 to 180 per cent. iodine. _Hemp-seed oil_ is produced from the seeds of the hemp plant which grows in Russia. This oil is used in soft soap-making, more particularly on the Continent. A typical sample gave the following figures:-- __________________________________________________ | | | | | | Specific | Saponification | Titre, | | | Gravity | Equivalent. | °C. | Iodine No. | | at 15° C. | | | | |___________|________________|________|____________| | | | | | | 0.926 | 292.6 | 15.8 | 143 | |___________|________________|________|____________| _Sunflower oil_ is produced largely in Russia. A specimen tested:-- ____________________________________________________________________ | | | | | | | Specific | Saponification | Acidity | Titre, | | | Gravity | Equivalent. | (as Oleic Acid) | °C. | Iodine No. | | at 15° C. | | Per Cent. | | | |___________|________________|_________________|________|____________| | | | | | | | 0.9259 | 290.7 | 0.81 | 17 | 126.2 | |___________|________________|_________________|________|____________| _Castor Oil._--The castor oil plant is really a native of India, but it is also cultivated in the United States (Illinois) and Egypt. A typical commercial sample tested:-- ________________________________________________________________________ | | | | | | | | Saponi- | Acidity | | | Optical | Refractive | | fication | (as Oleic | Titre, | Iodine No. | Rotation | Index | | Equi- | Acid) | °C. | | [alpha]_{D} | at 25° C. | | valent | Per Cent. | | | | | |___________|___________|________|____________|_____________|____________| | | | | | | | | 310 | 1.5 | 2.8 | 84.1 | + 4° 50' | 1.4787 | |___________|___________|________|____________|_____________|____________| _Fish and Marine Animal Oils._--Various oils of this class have, until recently, entered largely into the composition of soft soaps, but a demand has now arisen for soft soaps made from vegetable oils. We quote a few typical analyses of these oils:-- _________________________________________________________________________ | | | | | | | | | Specific | Saponi- | Acidity | | Unsaponi- | | | Gravity | fication | (as Oleic | Titre, | fiable | | | at 15°C. | Equi- | Acid) | °C. | Matter | | | | valent | Per Cent. | | Per Cent. | |__________________|__________|__________|___________|________|___________| | | | | | | | | Pale seal oil | 0.9252 | 289 | 0.947 | 15.5 | 0.8 | | Straw seal oil | 0.9231 | 288 | 4.77 | 15.8 | 1.2 | | Brown seal oil | 0.9253 | 291 | 16.38 | 16.2 | 1.9 | | Whale oil | 0.9163 | 297 | 1.49 | 16.1 | 1.8 | | Dark whale oil | 0.9284 | 303 | 12.60 | 21.8 | 2.4 | | Japan fish oil | 0.9336 | 296 | 4.79 | 26 | 0.67 | | Japan fish oil | 0.9325 | 302 | 10.43 | 28 | 1.55 | | Brown cod oil | 0.9260 | 313 | 14.91 | 21.8 | 1.9 | | Pure herring oil | 0.9353 | 288 | 11.39 | 21.6 | 1.5 | | Kipper oil | 0.9271 | 297 | 5.14 | 22.7 | 3.25 | |__________________|__________|__________|___________|________|___________| _Waste Fats._--Under this classification may be included marrow fat, skin greases, bone fats, animal grease, melted stuff from hotel and restaurant refuse, and similar fatty products. The following is a fair typical selection:-- _______________________________________________________________ | | | | | | | Saponification | Acidity | Titre, | | | Equivalent. | (as Oleic Acid) | °C. | | | | Per Cent. | | |___________________|________________|_________________|________| | | | | | | Marrow fat | 283.3 | 3.6 | 38.7 | | White skin grease | 287.2 | 4.3 | 36.4 | | Pale skin grease | 286.3 | 9.87 | 35.7 | | Pale bone fat | 289.7 | 8.8 | 40.7 | | Brown bone fat | 289.1 | 11.0 | 41 | | Brown bone fat | 292 | 20.5 | 40.2 | | Animal grease | 289.4 | 38.1 | 40.4 | | Melted stuff | 286.3 | 12.8 | 37.7 | |___________________|________________|_________________|________| The materials in the above class require to be carefully examined for the presence of unsaponifiable matter, lime salts and other impurities. _Fatty Acids._--We have already described the various methods of liberating fatty acids by hydrolysis or saponification. Under this heading should also be included stearines produced by submitting distilled fat to hydraulic pressure, the distillates from e from unsaponifiable matter, cocoa-nut oleine, a bye-product from the manufacture of edible cocoa-nut butter and consisting largely of free acids, and palm-nut oleine obtained in a similar manner from palm-nut oil. These are all available for soap-making. LESS-KNOWN OILS AND FATS OF LIMITED USE. _Shea Butter._--Shea butter is extracted from the kernels of the _Bassia Parkii_ and exported from Africa and Eastern India. This fat is somewhat tough and sticky, and the amount of unsaponifiable matter present is sometimes considerable. Samples examined by us gave the following data:-- _______________________________________________________________ | | | | | | Saponification | Acidity | Titre, | Refractive | | Equivalent. | (as Oleic Acid) | °C. | Index | | | Per Cent. | | at 60° C. | |________________|_________________|________|___________________| | | | | | | 313 | 8.2 | 53.2 | 1.4566 | | 303 | 7.33 | 53 | 1.4558 | | | | | 1.4471 (F. Acids) | |________________|_________________|________|___________________| _Mowrah-seed Oil._--The mowrah-seed oil now offered for soap-making is derived from the seeds of _Bassia longifolia_ and _Bassia latifolia_. It is largely exported from India to Belgium, France and England. The following are the results of some analyses made by us:-- _________________________________________________________ | | | | | | Saponification | Acidity | Titre, | Refractive | | Equivalent. | (as Oleic Acid) | °C. | Index | | | Per Cent. | | at 60° C. | |________________|_________________|________|____________| | | | | | | 291 | 10 | 43.4 | 1.4518 | | 291.5 | 7.1 | 42.7 | | | 291.2 | 9.9 | 43.8 | | | 292 | 11.26 | 40.5 | | |________________|_________________|________|____________| _Chinese vegetable tallow_ is the name given to the fat which is found coating the seeds of the "tallow tree" (_Stillingia sebifera_) which is indigenous to China and has been introduced to India where it flourishes. The following is a typical sample:-- _____________________________________ | | | | | Saponification | Acidity | Titre, | | Equivalent | Per Cent. | °C. | |________________|___________|________| | | | | | 280.2 | 5.24 | 52.5 | |________________|___________|________| The seeds of the "tallow tree" yield an oil (stillingia oil) having drying properties. _Borneo Tallow._--The kernels of several species of _Hopea_ (or _Dipterocarpus_), which flourish in the Malayan Archipelago, yield a fat known locally as Tangawang fat. This fat is moulded (by means of bamboo canes) into the form of rolls about 3 inches thick, and exported to Europe as Borneo Tallow. A sample tested by one of us gave the following data:-- ___________________________________________ | | | | | Saponification | Acidity | Titre, | | Equivalent. | (as Oleic Acid) | °C. | | | Per Cent. | | |________________|_________________|________| | | | | | 292 | 36 | 50.8 | |________________|_________________|________| _Kapok oil_ is produced from a tree which is extensively grown in the East and West Indies. The Dutch have placed it on the market and the figures given by Henriques (_Chem. Zeit._, 17, 1283) and Philippe (_Monit. Scient._, 1902, 730), although varying somewhat, show the oil to be similar to cotton-seed oil. VARIOUS NEW FATS AND OILS SUGGESTED FOR SOAP-MAKING. _Carapa_ or _Andiroba oil_, derived from the seeds of a tree (_Carapa Guianensis_) grown in West Indies and tropical America, has been suggested as suitable for soap-making. Deering (_Imperial Institute Journ._, 1898, 313) gives the following figures:-- ____________________________________________ | | | | | Saponification | Acidity | Melting Point | | Equivalent | Per Cent. | of Fatty | | | | Acids, °C. | |________________|___________|_______________| | | | | | 287 | 12 | 89 | |________________|___________|_______________| Another observer (_Rev. Chem. Ind._, 13, 116) gives the setting point of the fatty acids as 56.4° C. _Candle-nut oil_ obtained from the seeds of a tree flourishing in India and also the South Sea Islands. The following figures have been published:-- _____________________________________________________________________________ | | | | | | Saponi- | | | | | fication | Titre,| Iodine No. | Observers.| References. | Equiv- | | | | | alent.[1] | °C. | | | |___________|_______|____________|____________|_______________________________ | | | | | | 299-304.9 | 13 | 136.3-139.3| De Negri |_Chem. Centr._, 1898, p. 493. | 291 | | 163.7 | Lewkowitsch|_Chem. Revue_, 1901, p. 156. | 296 | 12.5 | 152.8 | Kassler |_Farben-Zeitung_, 1903, p. 359. |___________|_______|____________|____________|_______________________________ _Curcas oil_ is produced in Portugal from the seeds of the "purging nut tree," which is similar to the castor oil plant, and is cultivated in Cape Verde Islands and other Portuguese Colonies. The following data have been observed:-- ______________________________________________________________________________ | | | | | | Saponi- | | | | | fication | Titre,| Iodine No. | Observers.| References. | Equiv- | | | | | alent.[2] | °C. | | | |___________|_______|____________|____________|_______________________________ | | | | | | 291.4 | 0.36 | 99.5 | Archbut |_J. S. C. Ind._, 1898, p. 1010. | 290.3 | 4.46 | 98.3 | Lewkowitsch|_Chem. Revue_, 1898, p. 211. | 283.1 | 0.68 | 107.9 | Klein |_Zeits. angew. Chem._, | | | | | 1898, p. 1012. |___________|_______|____________|____________|_______________________________ The titre is quoted by Lewkowitsch as 28.6° C. _Goa butter_ or _Kokum butter_ is a solid fat obtained from the seeds of _Garcinia indica_, which flourishes in India and the East Indies. Crossley and Le Sueur (_Journ. Soc. Chem. Industry_, 1898, p. 993) during an investigation of Indian oils obtained these results:-- _________________________________________ | | | | | Saponification | Acidity | Iodine No. | | Equivalent.[3] | Per Cent. | | |________________|___________|____________| | | | | | 300 | 7.1 | 34.2 | |________________|___________|____________| _Safflower oil_ is extracted from the seeds of the _Carthamus tinctorius_, which, although indigenous to India and the East Indies, is extensively cultivated in Southern Russia (Saratowa) and German East Africa. Its use has been suggested for soft-soap making. The following figures have been published:-- ____________________________________________________________________________ | | | | | | | Saponi | | | | |fication | Iodine | Observers. | References. | | Equiv- | No. | | | |alent.[4]| | | |_________|_________|________|_____________|_________________________________ | | | | | | Average | 295.5 | 141.29 | Crossley and| _J. S. C. Ind._, 1898, p. 992; | of | | | Le Sueur | _J. S. C. Ind._, 1900, p. 104. | Twelve | 287.1 | 141.6 | Shukoff |_Chem. Revue_, 1901, p. 250. | Samples | 289.2 | 130 | Tylaikow |_Chem. Revue_, 1902, p. 106. | | 293.7 | 142.2 | Fendler |_Chem. Zeitung_, 1904, p. 867. |_________|_________|________|_____________|_________________________________ _Maripa fat_ is obtained from the kernels of a palm tree flourishing in the West Indies, but, doubtless, the commercial fat is obtained from other trees of the same family. It resembles cocoa-nut oil and gives the following figures:-- ___________________________________________________________________________ | | | | | | Saponi- | | Melting | | | fication | | Point | | | Equiv- | Iodine | of Fatty | | | alent.[5]| No. | Acids, °C.| Observer. | Reference. |__________|________|___________|___________|_______________________________ | | | | | | 217 | 9.49 | 25 | Bassière |_J. S. C. Ind._, 1903, p. 1137. |__________|________|___________|___________|_______________________________ _Niam fat_, obtained from the seeds of _Lophira alata_, which are found extensively in the Soudan. The fat, as prepared by natives, has been examined by Lewkowitsch, and more recently Edie has published the results of an analysis. The figures are as follows:-- __________________________________________________________________________ | | | | | | Saponi- | | | | | fication | Titre,| Iodine | Observers.| References. | Equiv- | | No. | | | alent.[6] | °C. | | | |___________|_______|________|____________|_______________________________ | | | | | | 295.1 | 78.12 | 42.5 | Lewkowitsch|_J. S. C. Ind._, 1907, p. 1266. | 287.7 | 75.3 | | Edïe. |_Quart. J. Inst. Comm. | | | | | Research in Tropics._ |___________|_______|________|____________|_______________________________ _Cohune-nut oil_ is produced from the nuts of the cohune palm, which flourishes in British Honduras. This oil closely resembles cocoa-nut and palm-nut oils and is stated to saponify readily and yield a soap free from odour. The following figures, obtained in the Laboratory of the Imperial Institute, are recorded in the official _Bulletin_, 1903, p. 25:-- ________________________________________________ | | | | | Saponification | Iodine No. | Melting Point of | | Equivalent. | | Fatty Acids, °C. | |________________|____________|__________________| | | | | | 253.9-255.3 | 12.9-13.6 | 27-30 | |________________|____________|__________________| _Mafoureira_ or _Mafura tallow_ from the nuts of the mafoureira tree, which grows wild in Portuguese East Africa. The following figures are published:-- ______________________________________________________________________________ | | | | | Saponi- | | | | fication | | Iodine | References. | Equi- | | No. | | valent. | | | |_____________|________________|___________|___________________________________ | | Titre, °C. | | | 253.8 | 44-48 | 46.14 | De Negri and Fabris, _Annal. del | | | | Lab. Chim. Delle Gabelle_, | | | | 1891-2, p. 271. | | Acidity | | | | (as Oleic Acid)| | | | Per Cent. | | _Bulletin Imp. Inst._, | 232.8-233.7 | 21.26 | 47.8-55.8 | 1903, p. 27. |_____________|________________|___________|___________________________________ _Pongam oil_, obtained from the beans of the pongam tree, which flourishes in East India, has been suggested as available for the soap industry, but the unsaponifiable matter present would militate against its use. Lewkowitsch (_Analyst_, 1903, pp. 342-44) quotes these results:-- _____________________________________________________________________ | | | | | | | | Saponi- | | | | | | fication | Iodine | Acidity, | Unsaponifiable, | | | Equi- | No. | Per Cent. | Per Cent. | | | valent.[7] | | | | |_________________|____________|________|___________|_________________| | | | | | | | Oil extracted | 315 | 94 | 3.05 | 9.22 | | in laboratory | | | | | | Indian specimen | 306 | 89.4 | 0.5 | 6.96 | |_________________|____________|________|___________|_________________| _Margosa oil_ is obtained from the seeds of _Melia azedarach_, a tree which is found in most parts of India and Burma. Lewkowitsch (_Analyst_, 1903, pp. 342-344) gives these figures:-- __________________________________ | | | | | Saponification | Iodine | Titre, | | Equivalent.[8] | No. | °C. | |________________|________|________| | | | | | 284.9 | 69.6 | 42 | |________________|________|________| _Dika fat_ or _Wild Mango oil_ is obtained from the seed kernels of various kinds of _Irvingia_ by boiling with water. Lemarié (_Bulletin Imp. Inst._, 1903, p. 206) states that this fat is used in the place of cocoa-nut oil in the manufacture of soap. Lewkowitsch (_Analyst_, 1905, p. 395) examined a large sample of dika fat obtained from seeds of _Irvingia bateri_ (South Nigeria) and gives the following data:-- ____________________________________________________ | | | | | | Saponification | Iodine | Titre, | Unsaponifiable, | | Equivalent.[9] | No. | °C. | Per Cent. | |________________|________|________|_________________| | | | | | | 229.4 | 5.2 | 34.8 | 0.73 | |________________|________|________|_________________| _Baobab-seed Oil._--Balland (_Journ. Pharm. Chem._, 1904, p. 529, abstracted in _Journ. Soc. Chem. Ind._, 1905, p. 34) states that the natives of Madagascar extract, by means of boiling water, from the seeds of the baobab tree, a whitish solid oil, free from rancidity, and possessed of an odour similar to Tunisian olive oil. He suggests that it may, with advantage, replace cocoa-nut oil in soap manufacture. _Persimmon-seed Oil._--Lane (_J. S. C. Ind._, 1905, p. 390) gives constants for this oil which he describes as semi-drying, of brownish yellow colour, and having taste and odour like pea-nut (arachis) oil. The following are taken from Lane's figures:-- ___________________________________ | | | | | Saponification | Iodine | Titre, | | Equivalent.[10] | No. | °C. | |_________________|________|________| | | | | | 298.4 | 115.6 | 20.2 | |_________________|________|________| _Wheat oil_, extracted from the wheat germ by means of solvents, has been suggested as applicable for soap-making (H. Snyder, abstr. _J. S. C. Ind._, 1905, p. 1074). The following figures have been published:-- _______________________________________________________________________________ | | | | | | | Saponi- | | | | | | fication | Acidity,| Iodine | Titre, | Observers. | References. | Equiv- | Per | No. | | | | alent.[11]| Cent. | | °C. | | |___________|_________|________|________|_____________|________________________ | | | | | | | 306 | 5.65 | 115.17 | 29.7 | De Negri. | _Chem. Zeit._, 1898 | | | | | | (abstr. _J. S. C. I._, | | | | | | 1898, p. 1155). | 297 | 20 | 115.64 | | Frankforter | _J. Amer. C. Soc._, | | | | | & Harding | 1899, 758-769 (abstr. | | | | | | in _J. S. C. I._, | | | | | | 1899, p. 1030). |___________|_________|________|________|_____________|________________________ _Tangkallah fat_, from the seeds of a tree growing in Java and the neighbouring islands, is suitable for soap-making. Schroeder (_Arch. Pharm._, 1905, 635-640, abstracted in _J. S. C. Ind._, 1906, p. 128) gives these values:-- _______________________________________________________ | | | | | | Saponification | Acidity, | Iodine | Unsaponifiable, | | Equivalent.[12]| Per Cent. | No. | Per Cent. | |________________|___________|________|_________________| | | | | | | 209 | 1.67 | 2.28 | 1.44 | |________________|___________|________|_________________| It is a hard fat, nearly white, possessing neither taste nor characteristic odour and solidifying at about 27° C. _Oil of Inoy-kernel._--(_Bulletin Imp. Inst._, 1906, p. 201). The seeds of Poga oleosa from West Africa yield on extraction an oil which gives the figures quoted below, and is suggested as a soap-maker's material:-- __________________________________ | | | | | Saponification | Iodine | Titre, | | Equivalent. | No. | °C. | |________________|________|________| | | | | | 304 | 89.75 | 22 | |________________|________|________| ROSIN. Rosin is the residuum remaining after distillation of spirits of turpentine from the crude oleo-resin exuded by several species of the pine, which abound in America, particularly in North Carolina, and also flourish in France and Spain. The gigantic forests of the United States consist principally of the long-leaved pine, _Pinus palustris (Australis)_, whilst the French and Spanish oleo-resin is chiefly obtained from _Pinus pinaster_, which is largely cultivated. Rosin is a brittle, tasteless, transparent substance having a smooth shining fracture and melting at about 135° C. (275° F.). The American variety possesses a characteristic aromatic odour, which is lacking in those from France and Spain. It is graded by samples taken out of the top of every barrel, and cut into 7/8 of an inch cubes, which must be uniform in size--the shade of colour of the cube determines its grade and value. The grades are as follows:-- W. W. (Water white.) W. G. (Window glass.) N. (Extra pale.) M. (Pale.) K. (Low pale.) I. (Good No. 1.) H. (No. 1.) G. (Low No. 1.) F. (Good No. 2.) E. (No. 2.) D. (Good strain.) C. (Strain.) B. (Common strain.) A. (Common.) Unsaponifiable matter is present in rosin in varying amounts. Below are a few typical figures taken from a large number of collated determinations:-- ________________________________________________________________ | | | | | | | | Saponification | Total | Free | Iodine | | | Equivalent. | Acid No. | Acid No. | No. | |________________|________________|__________|__________|________| | | | | | | | American W. W. | 330.5 | 169.7 | 119.1 | 126.9 | | American N. | 312.3 | 179.6 | 161.4 | 137.8 | | French | 320.5 | 175 | 168 | 120.7 | | Spanish | 313.4 | 179 | 160 | 129.8 | |________________|________________|__________|__________|________| ALKALI (CAUSTIC AND CARBONATED). The manufacture of alkali was at one time carried on in conjunction with soap-making, but of late years it has become more general for the soap manufacturer to buy his caustic soda or carbonated alkali from the alkali-maker. Although there are some alkali-makers who invoice caustic soda and soda ash in terms of actual percentage of sodium oxide (Na_{2}O), it is the trade custom to buy and sell on what is known as the English degree, which is about 1 per cent. higher than this. The English degree is a survival of the time when the atomic weight of sodium was believed to be twenty-four instead of twenty-three, and, since the error on 76 per cent. Na_{2}O due to this amounts to about 1 per cent., may be obtained by adding this figure to the sodium oxide really present. _Caustic soda_ (sodium hydrate) comes into commerce in a liquid form as 90° Tw. (and even as high as 106° Tw.), and other degrees of dilution, and also in a solid form in various grades as 60°, 70°, 76-77°, 77-78°. These degrees represent the percentage of sodium oxide (Na_{2}O) present plus the 1 per cent. The highest grade, containing as it does more available caustic soda and less impurities, is much more advantageous in use. _Carbonate of soda_ or _soda ash_, 58°, also termed "light ash," and "refined alkali". This is a commercially pure sodium carbonate containing about 0.5 per cent. salt (NaCl). The 58° represents the English degrees and corresponds to 99 per cent. sodium carbonate (Na_{2}CO_{3}). _Soda ash_, 48°, sometimes called "caustic soda ash," often contains besides carbonate of soda, 4 per cent. caustic soda (sodium hydrate), and 10 per cent. salt (sodium chloride), together with water and impurities. The 48 degrees refers to the amount of alkali present in terms of sodium oxide (Na_{2}O), but expressed as English degrees. _Caustic potash_ (potassium hydrate) is offered as a liquid of 50-52° B. (98-103° Tw.) strength, and also in solid form as 75-80° and 88-92°. The degrees in the latter case refer to the percentage of potassium hydrate (KHO) actually present. _Carbonate of Potash._--The standard for refined carbonate of potash is 90-92 per cent. of actual potassium carbonate (K_{2}CO_{3}) present, although it can be obtained testing 95-98 per cent. OTHER MATERIALS. _Water._--Water intended for use in soap-making should be as soft as possible. If the water supply is hard, it should be treated chemically; the softening agents may be lime and soda ash together, soda ash alone, or caustic soda. There are many excellent plants in vogue for water softening, which are based on similar principles and merely vary in mechanical arrangement. The advantages accruing from the softening of hard water intended for steam-raising are sufficiently established and need not be detailed here. _Salt_ (sodium chloride or common salt, NaCl) is a very important material to the soap-maker, and is obtainable in a very pure state. Brine, or a saturated solution of salt, is very convenient in soap-making, and, if the salt used is pure, will contain 26.4 per cent. sodium chloride and have a density of 41.6° Tw. (24.8° B.). The presence of sulphates alters the density, and of course the sodium chloride content. Salt produced during the recovery of glycerine from the spent lyes often contains sulphates, and the density of the brine made from this salt ranges higher than 42° Tw. (25° B.). _Soapstock._--This substance is largely imported from America, where it is produced from the dark-coloured residue, termed mucilage, obtained from the refining of crude cotton-seed oil. Mucilage consists of cotton-seed oil soap, together with the colouring and resinous principles separated during the treatment of the crude oil. The colouring matter is removed by boiling the mucilage with water and graining well with salt; this treatment is repeated several times until the product is free from excess of colour, when it is converted into soap and a nigre settled out from it. Soapstock is sold on a fatty acid basis; the colour is variable. FOOTNOTES: [1] Calculated by us from saponification value. [2] Calculated by us from saponification value. [3] Calculated by us from saponification value. [4] Calculated by us from saponification value. [5] Calculated by us from saponification value. [6] Calculated by us from saponification value. [7] Calculated by us from saponification value. [8] Calculated by us from saponification value. [9] Calculated by us from saponification value. [10] Calculated by us from saponification value. [11] Calculated by us from saponification value. [12] Calculated by us from saponification value. CHAPTER IV. BLEACHING AND TREATMENT OF RAW MATERIALS INTENDED FOR SOAP-MAKING. _Palm Oil--Cotton-seed Oil--Cotton-seed "Foots"--Vegetable Oils--Animal Fats--Bone Fat--Rosin._ Having described the most important and interesting oils and fats used or suggested for use in the manufacture of soap, let us now consider briefly the methods of bleaching and treating the raw materials, prior to their transference to the soap-pan. _Crude Palm Oil._--Of the various methods suggested for bleaching palm oil, the bichromate process originated by Watts is undoubtedly the best. The reaction may be expressed by the following equation, though in practice it is necessary to use twice the amount of acid required by theory:-- K_{2}Cr_{2}O_{7} + 14HCl = 2KCl + Cr_{2}Cl_{6} + 7H_{2}O + 6Cl. 6Cl + 3H_{2}O = 6HCl + 3O. The palm oil, freed from solid impurities by melting and subsidence, is placed in the bleaching tank, and washed with water containing a little hydrochloric acid. Having allowed it to rest, and drawn off the liquor and sediment (chiefly sand), the palm oil is ready for treatment with the bleaching reagent, which consists of potassium bichromate and commercial muriatic acid. For every ton of oil, 22 to 28 lb. potassium bichromate and 45 to 60 lb. acid will be found sufficient to produce a good bleached oil. The best procedure is to act upon the colouring matter of the oil three successive times, using in the first two treatments one-third of the average of the figures just given, and in the final treatment an appropriate quantity which can be easily gauged by the appearance of a cooled sample of the oil. The potassium bichromate is dissolved in hot water and added to the crude palm oil, previously heated to 125° F. (52° C.), the requisite amount of muriatic acid being then run in and the whole well agitated by means of air. The bright red colour of the oil gradually changes to dark brown, and soon becomes green. The action having proceeded for a few minutes, agitation is stopped, and, after allowing to settle, the green liquor is withdrawn. When sufficiently bleached the oil is finally washed (without further heating) with hot water (which may contain salt), to remove the last traces of chrome liquor. If the above operation is carried out carefully, the colouring matter will be completely oxidised. It is important, however, that the temperature should not be allowed to rise above 130° F. (54° C.) during the bleaching of palm oil, otherwise the resultant oil on saponification is apt to yield a soap of a "foxy" colour. The bleached oil retains the characteristic violet odour of the original oil. It has been suggested to use dilute sulphuric acid, or a mixture of this and common salt, in the place of muriatic acid in the above process. _Crude Cotton-seed Oil._--The deep colouring matter of crude cotton-seed oil, together with the mucilaginous and resinous principles, are removed by refining with caustic soda lye. The chief aim of the refiner is to remove these impurities without saponifying any of the neutral oil. The percentage of free fatty acids in the oil will determine the quantity of caustic lye required, which must only be sufficient to remove this acidity. Having determined the amount of free acidity, the quantity of caustic soda lye necessary to neutralise it is diluted with water to 12° or 15° Tw. (8° or 10° B.), and the refining process carried out in three stages. The oil is placed in a suitable tank and heated by means of a closed steam coil to 100° F. (38° C.), a third of the necessary weak caustic soda lye added in a fine stream or by means of a sprinkler, and the whole well agitated with a mechanical agitator or by blowing a current of air through a pipe laid on the bottom of the tank. Prolonged agitation with air has a tendency to oxidise the oil, which increases its specific gravity and refractive index, and will be found in the soap-pan to produce a reddish soap. As the treatment proceeds, the temperature may be carefully raised, by means of the steam coil, to 120° F. (49° C.). The first treatment having proceeded fifteen minutes, the contents of the tank are allowed to rest; the settling should be prolonged as much as possible, say overnight, to allow the impurities to precipitate well, and carry down the least amount of entangled oil. Having withdrawn these coloured "foots," the second portion of the weak caustic soda solution is agitated with the partially refined oil, and, when the latter is sufficiently treated, it is allowed to rest and the settled coloured liquor drawn off as before. The oil is now ready for the final treatment, which is performed in the same manner as the two previous ones. On settling, a clear yellow oil separates. If desired, the oil may be brightened and filtered, after refining to produce a marketable article, but if it is being refined for own use in the soap-house, this may be omitted. The residue or "foots" produced during the refining of crude cotton-seed oil, known in the trade as "mucilage," may be converted into "soapstock" as mentioned in the preceding chapter, or decomposed by a mineral acid and made into "black grease" ready for distillation by superheated steam. _Vegetable Oils._--The other vegetable oils come to the soap-maker's hand in a refined condition; occasionally, however, it is desirable to remove a portion of the free fatty acids, which treatment also causes the colouring matter to be preciptated. This is effected by bringing the oil and a weak solution of caustic lye into intimate contact. Cocoa-nut oil is often treated in this manner. Sometimes it is only necessary to well agitate the oil with 1-1/2 per cent. of its weight of a 12° Tw. (8° B.) solution of caustic soda and allow to settle. The foots are utilised in the soap-pan. _Animal Fats._--Tallows are often greatly improved by the above alkaline treatment at 165° F. (73° C.). It is one of the best methods and possesses advantages over acid processes--the caustic soda removes the free acid and bodies of aldehyde nature, which are most probably the result of oxidation or polymerisation, whereas the neutral fat is not attacked, and further, the alkaline foots can be used in the production of soap. _Bone fat_ often contains calcium (lime) salts, which are very objectionable substances in a soap-pan. These impurities must be removed by a treatment with hydrochloric or sulphuric acid. The former acid is preferable, as the lime salt formed is readily soluble and easily removed. The fat is agitated with a weak solution of acid in a lead-lined tank by blowing in steam, and when the treatment is complete and the waste liquor withdrawn, the last traces of acid are well washed out of the liquid fat with hot water. _Rosin._--Several methods have been suggested for bleaching rosin; in some instances the constitution of the rosin is altered, and in others the cost is too great or the process impracticable. The aim of these processes must necessarily be the elimination of the colouring matter without altering the original properties of the substance. This is best carried out by converting the rosin into a resinate of soda by boiling it with a solution of either caustic soda or carbonated alkali. The process is commenced by heating 37 cwt. of 17° Tw. (11° B.) caustic soda lye, and adding 20 cwt. of rosin, broken into pieces, and continuing the boiling until all the resinate is homogeneous, when an addition of 1-1/2 cwt. of salt is made and the boiling prolonged a little. On resting, the coloured liquor rises to the surface of the resinate, and may be siphoned off (or pumped away through a skimmer pipe) and the resinate further washed with water containing a little salt. The treatment with carbonated alkali is performed in a similar manner. A solution, consisting of 2-3/4 cwt. of soda ash (58°), in about four times its weight of water, is heated and 20 cwt. of rosin, broken into small pieces, added. The whole is heated by means of the open steam coil, and care must be taken to avoid boiling over. Owing to the liberation of CO_{2} gas, frothing takes place. A large number of patents have been granted for the preparation of resinate of soda, and many methods devised to obviate the boiling over. Some suggest mixing the rosin and soda ash (or only a portion of the soda ash) prior to dissolving in water; others saponify in a boiler connected with a trap which returns the resinate to the pan and allows the carbonic-acid gas to escape or to be collected. With due precaution the method can be easily worked in open vessels, and, using the above proportions, there will be sufficient uncombined rosin remaining to allow the resultant product to be pumped into the soap with which it is intended to intermix it, where it will be finally saponified thoroughly. The salt required, which, in the example given, would be 1-1/2 cwt., may be added to the solution prior to the addition of rosin or sprinkled in towards the finish of the boiling. When the whole has been sufficiently boiled and allowed to rest, the liquor containing the colouring matter will float over the resinate, and, after removal, may be replaced by another washing. Many other methods have been suggested for the bleaching, refining and treatment of materials intended for saponification, but the above practical processes are successfully employed. All fats and oils after being melted by the aid of steam must be allowed to thoroughly settle, and the condensed water and impurities withdrawn through a trap arrangement for collecting the fatty matter. The molten settled fatty materials _en route_ to the soap-pan should be passed through sieves sufficiently fine to free them from suspended matter. CHAPTER V. SOAP-MAKING. _Classification of Soaps--Direct Combination of Fatty Acids with Alkali--Cold Process Soaps--Saponification under Increased or Diminished Pressure--Soft Soap--Marine Soap--Hydrated Soaps, Smooth and Marbled--Pasting or Saponification--Graining Out--Boiling on Strength--Fitting--Curd Soaps--Curd Mottled--Blue and Grey Mottled Soaps--Milling Base--Yellow Household Soaps--Resting of Pans and Settling of Soap--Utilisation of Nigres--Transparent Soaps--Saponifying Mineral Oil--Electrical Production of Soap._ Soaps are generally divided into two classes and designated "hard," and "soft," the former being the soda salts, and the latter potash salts, of the fatty acids contained in the material used. According to their methods of manufacture, soaps may, however, be more conveniently classified, thus:-- (A) Direct combination of fatty acids with alkali. (B) Treatment of fat with definite amount of alkali and no separation of waste lye. (C) Treatment of fat with indefinite amount of alkali and no separation of waste lye. (D) Treatment of fat with indefinite amount of alkali and separation of waste lye. (A) _Direct Combination of Fatty Acids with Alkali._--This method consists in the complete saturation of fatty acids with alkali, and permits of the use of the deglycerised products mentioned in chapter ii., section 2, and of carbonated alkalies or caustic soda or potash. Fatty acids are readily saponified with caustic soda or caustic potash of all strengths. The saponification by means of carbonated alkali may be performed in an open vat containing a steam coil, or in a pan provided with a removable agitator. It is usual to take soda ash (58°), amounting to 19 per cent. of the weight of fatty acids to be saponified, and dissolve it in water by the aid of steam until the density of the solution is 53° Tw. (30° B.); then bring to the boil, and, whilst boiling, add the molten fatty acids slowly, but not continuously. Combination takes place immediately with evolution of carbonic acid gas, which causes the contents of the vat or pan to swell, and frequently to boil over. The use of the agitator, or the cessation of the flow of fatty acids, will sometimes tend to prevent the boiling over. It is imperative that the steam should not be checked but boiling continued as vigorously as possible until all the alkali has been absorbed and the gas driven off. The use of air to replace steam in expelling the carbonic acid gas has been patented (Fr. Pat. 333,974, 1903). A better method of procedure, however, is to commence with a solution of 64° Tw. (35° B.) density, made from half the requisite soda ash (9-1/2 per cent.), and when this amount of alkali has all been taken up by the fatty acids (which have been added gradually and with continuous boiling), the remaining quantity of soda ash is added in a dry state, being sprinkled over each further addition of fatty acid. This allows the process to be more easily controlled and boiling over is avoided. It is essential that the boiling by steam should be well maintained throughout the process until all carbonic acid gas has been thoroughly expelled; when that point is reached, the steam may be lessened and the contents of the vat or pan gently boiled "on strength" with a little caustic lye until it ceases to absorb caustic alkali, the soap being finished in the manner described under (D). It is extremely difficult to prevent discoloration of fatty acids, hence the products of saponification in this way do not compare favourably in appearance with those produced from the original neutral oil or fat. (B) _Treatment of Fat with Definite Amount of Alkali and no Separation of Waste Lye._--Cold-process soap is a type of this class, and its method of production is based upon the characteristic property which the glycerides of the lower fatty acids (members of the cocoa-nut-oil class) possess of readily combining with a strong caustic soda solution at a low temperature, and evolving sufficient heat to complete the saponification. Sometimes tallow, lard, cotton-seed oil, palm oil and even castor oil are used in admixture with cocoa-nut oil. The process for such soap is the same as when cocoa-nut oil is employed alone, with the slight alteration in temperature necessary to render the fats liquid, and the amount of caustic lye required will be less. Soaps made of these blends closely resemble, in appearance, milled toilet soaps. In such mixtures the glycerides of the lower fatty acids commence the saponification, and by means of the heat generated induce the other materials, which alone would saponify with difficulty or only with the application of heat, to follow suit. It is necessary to use high grade materials; the oils and fats should be free from excess of acidity, to which many of the defects of cold-process soaps may be traced. Owing to the rapidity with which free acidity is neutralised by caustic soda, granules of soap are formed, which in the presence of strong caustic lye are "grained out" and difficult to remove without increasing the heat; the soap will thus tend to become thick and gritty and sometimes discoloured. The caustic lye should be made from the purest caustic soda, containing as little carbonate as possible; the water used for dissolving or diluting the caustic soda should be soft (_i.e._, free from calcium and magnesium salts), and all the materials carefully freed from particles of dirt and fibre by straining. The temperature, which, of course, must vary with the season, should be as low as is consistent with fluidity, and for cocoa-nut oil alone may be 75° F. (24° C.), but in mixtures containing tallow 100° to 120° F. (38° to 49° C.). The process is generally carried out as follows:-- The fluid cocoa-nut oil is stirred in a suitable vessel with half its weight of 71.4° Tw. (38° B.) caustic soda lye at the same temperature, and, when thoroughly mixed, the pan is covered and allowed to rest. It is imperative that the oils and fats and caustic lye should be intimately incorporated or emulsified. The agitating may be done mechanically, there being several machines specially constructed for the purpose. In one of the latest designs the caustic lye is delivered through a pipe which rotates with the stirring gear, and the whole is driven by means of a motor. The agitation being complete, chemical action takes place with the generation of heat, and finally results in the saponification of the fats. At first the contents of the pan are thin, but in a few hours they become a solid mass. As the process advances the edges of the soap become more transparent, and when the transparency has extended to the whole mass, the soap is ready, after perfuming, to be framed and crutched. The admixture of a little caustic potash with the caustic soda greatly improves the appearance of the resultant product, which is smoother and milder. The glycerine liberated during the saponification is retained in the soap. Although it is possible, with care, to produce neutral soaps of good appearance and firm touch by this method, cold-process soaps are very liable to contain both free alkali and unsaponified fat, and have now fallen considerably into disrepute. _Saponification under Increased or Diminished Pressure._--Soaps made by boiling fats and oils, under pressure and _in vacuo_, with the exact quantity of caustic soda necessary for complete combination, belong also to this class. Amongst the many attempts which have at various times been made to shorten the process of soap-making may be mentioned Haywood's Patent No. 759, 1901, and Jourdan's French Patent No. 339,154, 1903. In the former, saponification is carried out in a steam-jacketed vacuum chamber provided with an elaborate arrangement of stirrers; in the other process fat is allowed to fall in a thin stream into the amount of lye required for saponification, previously placed in the saponification vessel, which is provided with stirring gear. When the quantities have been added, steam is admitted and saponification proceeds. (C) _Treatment of Fat with Indefinite Amount of Alkali and no Separation of Waste Lye._--_Soft soap_ is representative of this class. The vegetable fluid oils (linseed, olive, cotton-seed, maize) are for the most part used in making this soap, though occasionally bone fats and tallow are employed. Rosin is sometimes added, the proportion ranging, according to the grade of soap required, from 5 to 15 per cent. of the fatty matter. The Soft Soap Manufacturers' Convention of Holland stipulate that the materials used in soft-soap making must not contain more than 5 per cent. rosin; it is also interesting to note that a patent has been granted (Eng. Pat. 17,278, 1900) for the manufacture of soft soap from material containing 50 per cent. rosin. Fish or marine animal oils--whale, seal, etc., once largely used as raw material for soft soap, have been superseded by vegetable oils. The materials must be varied according to the season; during hot weather, more body with a less tendency to separate is given by the introduction of oils and fats richer in stearine; these materials also induce "figging". The most important material, however, is the caustic potash lye which should average 40° Tw. (24° B.), _i.e._, if a weak solution is used to commence saponification, a stronger lye must be afterwards employed to avoid excess of water in the soap, and these average 40° Tw. (24° B.). The potash lye must contain carbonates, which help to give transparency to the resultant soap. If the lye is somewhat deficient in carbonates, they may be added in the form of a solution of refined pearl ash (potassium carbonate). Caustic soda lye is sometimes admixed, to the extent of one-fourth, with potash lye to keep the soap firmer during hot weather, but it requires great care, as a slight excess of soda gives soft soap a bad appearance and a tendency to separate. The process is commenced by running fatty matter and weak potash lyes into the pan or copper, and boiling together, whilst the introduction of oil and potash lye is continued. The saponification commences when an emulsion forms, and the lye is then run in more quickly to prevent the mass thickening. Having added sufficient "strength" for complete saponification, the boiling is continued until the soap becomes clear. The condition of the soap is judged by observing the behaviour of a small sample taken from the pan and dropped on glass or iron. If the soap is satisfactory it will set firm, have a short texture and slightly opaque edge, and be quite clear when held towards the light. If the cooled sample draws out in threads, there is an excess of water present. If an opaque edge appears and vanishes, the soap requires more lye. If the sample is turbid and somewhat white, the soap is too alkaline and needs more oil. The glycerine liberated during saponification is contained in the soap and no doubt plays a part in the production of transparency. _Hydrated soaps_, both smooth and marbled, are included in this classification, but are _soda_ soaps. Soap made from cocoa-nut oil and palm-kernel oil will admit of the incorporation of large quantities of a solution of either salt, carbonate of soda, or silicate of soda, without separation, and will retain its firmness. These materials are, therefore, particularly adapted for the manufacture of marine soaps, which often contain as much as 80 per cent. of water, and, being soluble in brine, are capable of use in sea-water. For the same reason, cocoa-nut oil enters largely into the constitution of hydrated soaps, but the desired yield or grade of soap allows of a variation in the choice of materials. Whilst marine soap, for example, is usually made from cocoa-nut oil or palm-kernel oil only, a charge of 2/3 cocoa-nut oil and 1/3 tallow, or even 2/3 tallow and 1/3 cocoa-nut oil, will produce a paste which can carry the solutions of silicate, carbonate, and salt without separation, and yield a smooth, firm soap. The fatty materials, carefully strained and freed from particles of dirt and fibre, are boiled with weak caustic soda lye until combination has taken place. Saponification being complete, the solution of salt is added, then the carbonate of soda solution, and finally the silicate of soda solution, after which the soap is boiled. When thoroughly mixed, steam is shut off, and the soap is ready for framing. The marbled hydrated soap is made from cocoa-nut oil or a mixture of palm-kernel oil and cocoa-nut oil with the aid of caustic soda lye 32-1/2° Tw. (20° B.). As soon as saponification is complete, the brine and carbonate of soda solution are added, and the pan allowed to rest. The soap is then carefully tasted as to its suitability for marbling by taking samples and mixing with the colouring solution (ultramarine mixed with water or silicate of soda solution). If the sample becomes blue throughout, the soap is too alkaline; if the colour is precipitated, the soap is deficient in alkali. The right point has been reached when the marbling is distributed evenly. Having thus ascertained the condition of the pan, and corrected it if necessary, the colour, mixed in water or in silicate of soda solution, is added and the soap framed. (D) _Treatment of Fat with Indefinite Amount of Alkali and Separation of Waste Lye._--This is the most general method of soap-making. The various operations are:-- (_a_) Pasting or saponification. (_b_) Graining out or separation. (_c_) Boiling on strength. And in the case of milling soap base and household soaps, (_d_) Fitting. (_a_) _Pasting or Saponification._--The melted fats and oils are introduced into the soap-pan and boiled by means of open steam with a caustic soda lye 14° to 23.5° Tw. (10° to 15° B.). Whether the fatty matters and alkali are run into the pan simultaneously or separately is immaterial, provided the alkali is not added in sufficient excess to retard the union. The commencement of the saponification is denoted by the formation of an emulsion. Sometimes it is difficult to start the saponification; the presence of soap will often assist this by emulsifying the fat and thus bringing it into intimate contact with the caustic soda solution. When the action has started, caustic soda lye of a greater density, 29° to 33° Tw. (18° to 20° B.), is frequently added, with continued boiling, in small quantities as long as it is being absorbed, which is ascertained by taking out samples from time to time and examining them. There should be no greasiness in the sample, but when pressed between finger and thumb it must be firm and dry. Boiling is continued until the faint caustic taste on applying the cooled sample to the tongue is permanent, when it is ready for "graining out". The pasty mass now consists of the soda salts of the fat (as imperfect soap, probably containing emulsified diglycerides and monoglycerides), together with water, in which is dissolved the glycerine formed by the union of the liberated glyceryl radicle from the fat with the hydroxyl radicle of the caustic soda, and any slight excess of caustic soda and carbonates. The object of the next operation is to separate this water (spent lye) from the soap. (_b_) _Graining Out or Separation._--This is brought about by the use of common salt, in a dry form or in solution as brine, or by caustic soda lye. Whilst the soap is boiling, the salt is spread uniformly over its surface, or brine 40° Tw. (24° B.) is run in, and the whole well boiled together. The soap must be thoroughly boiled after each addition of salt, and care taken that too large a quantity is not added at once. As the soap is gradually thrown out of solution, it loses its smooth transparent appearance, and becomes opaque and granular. When a sample, taken out on a wooden trowel, consists of distinct grains of soap and a liquid portion, which will easily separate, sufficient salt or brine has been added; the boiling is stopped and the spent lye allowed to settle out, whilst the soap remains on the surface as a more or less thick mass. The separated spent lye consists of a solution of common salt, glycerine, and alkaline salts; the preparation of crude glycerine therefrom is considered in chapter ix. The degree of separation of water (spent lye) depends upon the amount of precipitant used. The aim is to obtain a maximum amount of spent lye separated by the use of a minimum quantity of salt. The amount of salt required for "graining out" varies with the raw material used. A tallow soap is the most easily grained, more salt is required for cotton-seed oil soap, whereas soaps made from cocoa-nut and palm-kernel oils require very large amounts of salt to grain out thoroughly. Owing to the solubility in weak brine of these latter soaps, it is preferable to grain them with caustic soda lye. This is effected by adding, during boiling, sufficient caustic lye (32-1/2° Tw., 20° B.) to produce the separation of the granules of soap. The whole is allowed to rest; the separated half-spent lye is withdrawn and may be used for the pasting of fresh materials. After the removal of the settled lye, the grained mass is boiled with sufficient water to dissolve the grain and make it smooth ("close" it), and is now ready for the next operation of "boiling on strength". (_c_) _Boiling on Strength or Clear Boiling._--This is the most important operation and is often termed "making the soap". The object is to harden the soap and to ensure complete saponification. Caustic soda lye (32-1/2° Tw., 20° B.) is gradually added until the soap is again opened or grained, and boiling continued by the use of the dry steam coil. As soon as the caustic soda lye is absorbed, another portion is slowly added, and this is continued until the caustic soda or "strength" remains permanent and the soapy mass, refusing to absorb more, is thrown out of solution and grained. The granular mass will boil steadily, and the boiling should be prolonged, as the last traces of neutral oil are difficult to completely saturate with alkali. Thorough saponification takes place gradually, and the operation cannot be hurried; special care has to be bestowed upon this operation to effect the complete combination of fat and alkali. After resting for several hours, half-spent lye settles to the bottom of the pan. In the case of yellow soaps or milling bases the settled lye is removed to a suitable receptacle and reserved for use in the saponification of other material, and the soap is then ready for the final operation of "fitting". (_d_) _Fitting._--If the operations just described have been properly performed, the fitting should present no difficulty. The soap is boiled with open steam, and water added until the desired degree of closing is attained. As the water is thoroughly intermixed throughout the mass the thick paste gradually becomes reduced to a smooth, thin consistence. Samples are tested from time to time as to their behaviour in dropping off a hot trowel held sideways; the thin layer should drop off in two or three flakes and leave the surface of the trowel clean and dry. The soap is then in a condition to allow the impurities to gravitate. According to the required soap, the fit may be "coarse" ("open") when the flakes drop off the trowel readily, or "fine" ("close") when the flakes only leave the trowel with difficulty. If the dilution with water has been allowed to proceed too far, and too fine a fit is produced, which would be denoted by the layer of soap not leaving the trowel, a little caustic lye or brine may be very carefully added and the whole well boiled until the desired condition is obtained. A good pressure of steam is now applied to the pan, causing the contents to swell as high as possible, this greatly facilitating the settling of impurities; steam is then turned off, the pan covered, and the boil allowed to rest for several days. The art of fitting consists in leaving the contents of the pan in such a condition that, on standing, all the impurities precipitate, and the settled soap, containing the correct amount of water, is clear and bright. The above is a general practical outline of the ordinary soap-boiling process. It may be modified or slightly altered according to the fancy of the individual soap-maker or the particular material it is desired to use. Fats and oils not only vary in the amount of alkali they absorb during saponification, but also differ in the strength of the alkali they require. Tallow and palm oil require lye of a density of 15° to 18° Tw. (10° to 12° B.), but cocoa-nut oil alone would not saponify unless the lye was more concentrated, 33° to 42° Tw. (20° to 25° B.). Cotton-seed oil requires weak lyes for saponification, and, being difficult to saponify alone even with prolonged boiling, is generally mixed with animal fat. When fats are mixed together, however, their varying alkali requirements become modified, and once the saponification is begun with weak lye, other materials are induced to take up alkali of a strength with which alone they would not combine. It is considered the best procedure to commence the pasting or saponification with weak lye. In order to economise tank space, it is the general practice to store strong caustic lye (60° to 70° Tw., 33° to 37° B.) and to dilute it as it is being added to the soap-pan by the simultaneous addition of water. Many manufacturers give all their soap a "brine wash" to remove the last traces of glycerine and free the soap from carbonates. This operation takes place prior to "fitting"; sufficient water is added to the boiling soap to "close" it and then brine is run in to "grain" it. After resting, the liquor is withdrawn. Having described the necessary operations in general, we will now consider their application to the preparation of various kinds of hard soap. _Curd Soaps._--Tallow is largely used in the manufacture of white curd soaps, but cocoa-nut oil sometimes enters into their composition. The first three operations above described, _viz._, pasting, graining out, and boiling on strength, are proceeded with; the clear boiling by means of a closed steam coil is continued until the "head" is boiled out and the soap is free from froth. A sample taken and cooled should be hard. Boiling is then stopped, and, after covering, the pan is allowed to rest for eight to ten hours, when the soap is ready for filling into frames, where it is crutched until perfectly smooth. _Curd mottled_ is usually made from melted kitchen stuff and bone grease. Its preparation is substantially the same as for curd soap, but the clear boiling is not carried so far. The art of curd mottled soap-making lies in the boiling. If boiled too long the mottling will not form properly, and, on the other hand, insufficient boiling will cause the soap to contain an excess of entangled lye. Having boiled it to its correct concentration the pan is allowed to rest about two hours, after which the soap is ready for framing, which should be done expeditiously and the frames covered up. Some lye, containing the impurities from the fats used, remains in the interstices of the curd, unable to sink, and as the soap cools it is enclosed and forms the mottling. The mottling may, therefore, be considered as a crystallisation of the soap, in which the impurity forms the colour. _Blue and Grey Mottled Soaps._--These are silicated or liquored soaps in which the natural mottling, due to the impure materials used in the early days of soap-making, is imitated by artificial mottling, and are, consequently, entirely different to curd mottled soaps. The materials employed in making mottled soap comprise bleached palm oil, tallow, bone fat, cocoa-nut oil, palm-kernel oil, cotton-seed oil, and, in some instances, rosin. The choice of a charge will naturally depend upon the cost; the property of absorbing a large amount of liquor, which is characteristic of soaps made from cocoa-nut oil and palm-kernel oil, is taken advantage of, as are also the physical properties of the various fats and oils, with a view to the crystallisation of the resultant soap and the development of the mottle. The fat is saponified, grained and boiled on strength, as previously described. After withdrawing the half-spent lye, the soap is just closed by boiling with water, and is then ready for the silicate or other saline additions. Soap intended to be liquored with silicate of soda should be distinctly strong in free alkali; the crystalline nature of the soap is increased thereby, and the mottled effect intensified. Some makers, however, fit the soap coarsely and allow a nigre to deposit; then, after removing the nigre, or transferring the settled soap to another copper, containing scraps of mottled soap, get the soap into a condition for mottling, and add the silicate of soda solution. To every 1 cwt. of soap, 28 lb. of silicate of soda solution, 32-1/2° Tw. (20° B.) is added, whilst boiling; the strength of the silicate solution, however, will depend upon the proportion of cocoa-nut oil and palm-kernel oil present in the charge. Many soap-makers use 20° Tw. (13° B.) (cold) silicate solution, whilst others prefer 140° Tw. (59.5° B.), with the gradual addition of water to the soap, kept boiling, until the product is in the correct mottling condition, and others, again, use bleach liquor, soda crystals, pearl ash, and salt, together with silicate solution. Considerable skill and experience is necessary to discern when the soap acquires the correct mottling state. It should drop off the spatula in large thick flakes, take considerable time to set, and the surface should not be glossy. When this mottling condition has been obtained, the colouring matter, which would be ultramarine for the blue mottled and manganese dioxide for the grey mottled soap (3-4 lb. ultramarine or 1-3 lb. manganese dioxide being sufficient for 1 ton of soap), is mixed with a little water and added to the boiling soap--the boiling is continued until all is thoroughly amalgamated, and when the steam is shut off the contents of the pan are ready for cleansing. Mottled soap is run into wooden frames, which, when full, are covered over and allowed to cool very gradually. On cooling slowly, large crystals are produced which result in a distinct bold mottle; if the cooling is too rapid, a small crystal is obtained and the mottle is not distributed, resulting in either a small mottle, or no mottle at all, and merely a general coloration. In fact, the entire art of mottling soap consists in properly balancing the saline solutions and colouring matter, so that the latter is properly distributed throughout the soap, and does not either separate in coloured masses at the bottom of the frame, or uniformly colour the whole mass. A sample of the soap should test 45 per cent. fatty acids, and the amount of salt would range from 1/2 to 1 per cent. Some of the English mottled soaps, especially those made from materials which give a yellow-coloured ground, are bleached by soaking in brine, or pickling in brine containing 2 per cent. of bleach liquor. The resultant soap has a white ground and is firm. The bleach liquor may be made by mixing 1 cwt. bleaching powder with 10 cwts. of soda ash solution (15° Tw., 10° B.), allowing to settle, and using the clear liquid, or by mixing 2 parts soda ash solution with 1 part of bleaching powder solution, both solutions being 30° Tw. (18.8° B.). _Milling-base._--The materials generally used are tallows and cocoa-nut oils of the finest quality. The tallow is thoroughly saponified first, and the graining is performed by the aid of caustic soda lye in preference to salt. The half-spent lyes are withdrawn, and the cocoa-nut oil added to the pan. This is saponified, and when the saponification is complete, "boiling-on-strength" is proceeded with. Special care should be devoted to the "boiling-on-strength" operation--its value in good soap-making cannot be over-rated--and perfect saponification must be ensured. The half-spent lyes are allowed to deposit during the night, and the soap must be carefully examined next morning to ascertain if any alkali has been absorbed. If the caustic taste is permanent the strengthening operation is complete, but should any caustic have been absorbed, further addition of alkali must be made and the boiling continued. These remarks apply equally to all soaps. The soap, when ready, is fitted. Bleached palm oil, olive oil, castor oil and lard are also employed in the production of special milling soap bases, a palm oil soap being specially suitable for the production of a violet-scented toilet soap. _Yellow Household Soaps._ (_a_) _Bar Soaps._--These are made from tallow with an admixture of from 15-25 per cent. rosin. The best quality is known in the South and West of England as Primrose Soap, but is designated in the North of England by such names as Golden Pale, Imperial Pale, Gold Medal Pale, etc. Tallow alone produces a very hard soap of inferior lathering qualities; but rosin combines with alkali to form a soft body, which, although not a soap in the strict sense of the term, is readily soluble in water, and in admixture with the durable tallow soap renders it more soluble in water and thereby increases its lathering properties. The rosin may be added to the soap-pan after a previous partial saponification with soda ash, and removal of colouring matter, and finally saponified with caustic soda lye, or, as is more generally adopted, as a rosin change. The pan is opened with caustic soda lye and saturation of the rosin takes place rapidly; when completely saponified it is grained with salt, and the coloured lye allowed to deposit and finally withdrawn. The four operations already detailed apply to this soap. Cheaper pale soaps may be made from lower grades of tallow and rosin and are generally silicated. (_b_) _Tablet or Washer Type._--A demand has arisen for soap of free lathering qualities, which has become very popular for general household use. This soap is usually made from a mixture of cotton-seed oil, tallow, and cocoa-nut oil, with a varying amount of rosin. The tallow yields firmness and durability whilst the other constituents all assist in the more ready production of a copious lather. As to what amount of rosin can be used to yield a finished soap of sufficient body and satisfactory colour, this naturally depends upon the grade of raw material at the soap-makers' disposal. Those fats and oils which yield firm soaps, will, of course, allow a greater proportion of rosin to be incorporated with them than materials producing soaps of less body. Rosin imparts softness to a soap, and also colour. This is a fitted soap and full details of manufacture have already been given. Cheaper soaps are produced from lower grade materials hardened with alkaline solutions. _Resting of Pans and Settling of Soap._--The fitted soap is allowed to settle from four to six days. The period allowed for resting is influenced, however, not only by the size of the boil, and the season, but also by the composition of the soap, for if the base has been made from firm stock it is liable to cool quicker than a soap produced from soft-bodied materials. On subsidence, the contents of the pan will have divided into the following:-- First. On top, a thin crust of soap, with perhaps a little light coloured fob, which is returned to the pan after the removal of the good soap. Second. The good settled soap, testing 62-63 per cent. fatty acids. The subject of removing and treatment of this layer is fully dealt with in the next chapter. Third. A layer of darker weak soap, termed "nigre," which on an average tests 33 per cent. fatty acids, and, according to the particular fit employed, will amount to from 15-20 per cent. of the total quantity of soap in the pan. The quantity of nigre may vary not only with the amount of water added during finishing, but is also influenced by the amount of caustic alkali remaining in the soap paste prior to fitting. If the free caustic alkali-content is high, the soap will require a large amount of water to attain the desired fit. This water renders the caustic into a lye sufficiently weak to dissolve a quantity of soap, consequently, as the "nigre" is a weak solution of soap together with any excess of alkali (caustic or carbonate) and salt which gravitates during the settling, the quantity is increased. Fourth. A solution containing alkaline salts, mostly carbonates and chlorides, with a little caustic. The amount of the layer is very variable, and doubtless, under certain physical conditions, this liquor has separated from the nigre. _Utilisation of Nigres._--The nigres are boiled and the liquor separated by graining with salt. Nigre may be utilised in various ways. (1) It may be used several times with new materials. This particularly refers to soaps of the "Washer" type. The colour of the nigre will determine the number of times it can be employed. (2) It may be incorporated with a soap of a lower grade than the one from which it was obtained. In this case a system is generally adopted; for example, soap of the best quality is made in a clean pan, the nigre remaining is worked up with fresh material for soap of the next quality, the nigre from that boil, in its turn, is admixed with a charge to produce a batch of third quality, and the deposited nigre from this is again used for a fourth quality soap--the nigre obtained from this latter boil would probably be transferred into the cheapened "washer" or perhaps if it was dark in colour into the brown soap-pan. (3) The nigre may be fitted and produce a soap similar to the original soap from which it was deposited. It is advisable to saponify a little fat with it. (4) Nigres from several boils of the same kind of soap can be collected, boiled, and fitted. The settled portion may be incorporated with a new charging to keep the resultant soap uniform in colour--unless this is done, the difference in colour between boils from new materials alone, and those containing nigre, is very noticeable. The nigre settled from this fitted nigre boil would be utilised in brown soap. (5) According to its colour, and consistence, a nigre may be suitable for the production of disinfectant, or cold-water soaps. (6) Nigre may be bleached by treatment with a 20 per cent. solution of stannous chloride--1 cwt. of this solution (previously heated) is sufficient to bleach 20 tons of nigre. _Transparent Soaps._--The production of transparent soaps has recently been fully studied, from a theoretical point of view, by Richardson (_J. Amer. Chem. Soc._, 1908, pp. 414-20), who concludes that the function of substances inducing transparency, is to produce a jelly and retard crystallisation. The old-fashioned transparent soap is prepared by dissolving, previously dried, genuine yellow soap in alcohol, and allowing the insoluble saline impurities to be deposited and removed. The alcoholic soap solution is then placed in a distillation apparatus, or the pan containing the solution is attached by means of a still head to a condenser, and the alcohol distilled, condensed and regained. The remaining liquid soap, which may be coloured and perfumed, is run into frames and allowed to solidify. The resultant mass is somewhat turbid, but after storage in a room at 95° F. (35° C.) for several months, becomes transparent. The formation of the transparency is sometimes assisted and hastened by the addition of glycerine or a solution of cane-sugar. A patent has been granted to A. Ruch (Fr. Pat. 327,293, 1902) for the manufacture of transparent glycerine soap by heating in a closed vessel fatty acids together with the requisite quantity of alcoholic caustic soda solution necessary for saponification, and cooling the resultant soap. It is also proposed to add sugar solution. Cheaper qualities of transparent soaps are made by the cold process with or without the aid of alcohol and castor oil, and with the assistance of glycerine or cane-sugar. With the continual demand for cheaper production, sugar solution has gradually, in conjunction with castor oil, which produces transparency, superseded the use of alcohol and glycerine. For a small batch, 56 lb. Cochin cocoa-nut oil and 56 lb. sweet edible tallow may be taken, melted at 130° F. (54° C.), and carefully strained into a small steam-jacketed pan. It is imperative that the materials should be of the highest quality and perfectly clean. Twenty-three lb. of pure glycerine and 56 lb. of bright caustic soda solution made from high grade caustic and having a density of 72° Tw. (38° B.) are crutched into the fat; the alcohol, which would be 45 lb. in this example, is then added. The whole must be most intimately incorporated, and the pan covered and allowed to rest for one hour or one and a half hours. Saponification should ensue. To produce a transparent glycerine soap with the aid of castor oil, and with or without the use of alcohol, the following is the procedure:-- Cochin cocoa-nut oil, sweet edible tallow, and castor oil, of each 56 lb. are taken, warmed to 130° F. (54° C.), and carefully strained into the jacketed pan. If it is desired to use glycerine and cane sugar solution, and no alcohol, the glycerine (25 lb.) is now stirred into the fats together with the requisite (83 lb.) caustic soda solution 72° Tw. (38° B.). If it is intended to use alcohol and sugar, and no glycerine, the latter is replaced by 47 lb. of alcohol, and added after the incorporation of the caustic soda lye. The whole being thoroughly crutched, the pan is covered and saponification allowed to proceed for one hour or one and a half hours. Should the saponification for some reason be retarded, a little steam may be very cautiously admitted to the jacket of the pan, the mass well crutched until the reaction commences, and the whole allowed to rest the specified time. Whilst saponification is proceeding, the "sugar solution" is prepared by dissolving 50 lb. cane sugar in 50 lb. water, at 168° F. (76° C.), to which may be added 5 lb. soda crystals, and any necessary colouring matter. The water used for this solution should be as soft as possible, as hard water is liable to produce opaque streaks of lime soap. It is absolutely necessary before proceeding further to ensure that saponification is complete. A greasy, soft feel and the presence of "strength" (caustic) would denote incomplete saponification--this can only be remedied by further heating and crutching. Deficiency of caustic alkali should also be avoided, and, if more lye is required, great care must be exercised in its addition. Saponification being completed, the sugar solution is carefully and gradually crutched into the soap; when the contents of the pan have become a homogeneous and syrupy mass, the crutching is discontinued, and the pan is covered for one hour. The heat of the soap in the pan should not exceed 170° F. (77° C.). Having rested the necessary period, the soap will have a slight froth on the surface, but will be clear underneath and appear dark. Samples may now be withdrawn, cooled, and examined prior to framing. If the process has been successfully performed the soap will be firm and transparent, of uniform colour, and possess only a faintly alkaline taste. If the sample be firm but opaque, more sugar solution is required; this should be added very carefully whilst crutching, an excess being specially guarded against. If the sample be soft, although transparent, and the alkaline taste not too pronounced, the soap evidently contains an excess of water, which may be remedied by the addition of a small quantity of soda ash; too much soda ash (carbonates) must be avoided, lest it should produce efflorescence. Having examined the soap and found it to be correct, or having remedied its defects, the soap in the pan is allowed to cool to 145° F. (63° C.) and perfume added. The soap is now quickly filled into narrow frames and allowed to cool rapidly. The blocks of soap should not be stripped until quite cold throughout, and they should be allowed to stand open for a while before slabbing. When freshly cut into tablets, the soap may appear somewhat turbid, but the brightness comes with the exposure it will receive prior to stamping and wrapping. _Saponifying Mineral Oil._--This sounds somewhat incongruous, as mineral oil is entirely unsaponifiable. Most of the suggestions for this purpose consist of the incorporation of mineral oil, or mineral oil emulsified by aid of Quillaia bark, with a cocoa-nut oil soap, and in all these instances the hydrocarbon merely exists in suspension. G. Reale (Fr. Pat. 321,510, 1902), however, proposes to heat mineral oil together with spermaceti and strong alkali, and states that he transforms the hydrocarbons into alcohols, and these, absorbing oxygen, become fatty acids, which are converted into soap by means of the alkali. In this connection may be quoted the interesting work of Zelinsky (_Russ. Phys. Chem. Ges. Zeits. Angew. Chem._, 1903, 37). He obtained substances, by acting with carbon dioxide upon magnesia compounds of chlorinated fractions of petroleum, which when decomposed by dilute sulphuric acid, yielded various organic acids. One of these acids on heating with glycerine formed tri-octin, which had the properties of a fat. Dr. Engler, in confirmation of the theory of the animal origin of some petroleums, obtained what might be described as petroleum (for it contained almost all the hydrocarbons present in the natural mineral oil) by distilling animal fats and oils under pressure. _Electrical Production of Soap._--Attempts have been made to produce soap electrically by Messrs. Nodon, Brettonneau and Shee (Eng. Pat. 22,129, 1897), and also by Messrs. Merry and Noble (Eng. Pat. 2,372, 1900). In the former patent, a mixture of soda-lye and fat is agitated by electricity at a temperature of 194°-212° F. (90°-100° C.), while in the latter caustic alkali is electrolytically produced from brine, and deposited on wire-netting in the presence of fat, which is thereby saponified. CHAPTER VI. TREATMENT OF SETTLED SOAP. _Cleansing--Crutching--Liquoring of Soaps--Filling--Neutralising, Colouring and Perfuming--Disinfectant Soaps--Framing--Slabbing--Barring--Open and Close Piling--Drying--Stamping--Cooling._ _Cleansing._--After completion of saponification, and allowing the contents of the pan to settle into the various layers, as described in the preceding chapter, the actual soap, forming the second layer, is now transferred to the frames, this being generally termed "cleansing" the soap. The thin crust or layer at the top of the pan is gently removed, and the soap may be either ladled out and conveyed to the frames, or withdrawn by the aid of a pump from above the nigre through a skimmer (Fig. 1), and pipe, attached by means of a swivel joint (Fig. 2) (which allows the skimmer pipe to be raised or lowered at will by means of a winch, Fig. 3), to a pipe fitted in the side of the pan as fully shown in Fig. 4, or the removal may be performed by gravitation through some mechanical device from the side of the copper. [Illustration: FIG. 1.--Skimmer, with flange for attachment to skimmer-pipe.] Every precaution is taken to avoid the presence of nigre in the soap being cleansed. [Illustration: FIG. 2.--Swivel-joint.] The temperature at which soap may be cleansed depends on the particular grade--soaps requiring to be liquored should not be cleansed too hot or a separation will take place, 150° F. (66° C.) may be taken as a suitable temperature for this class of soap; in the case of firm soaps, such as milling base, where cooling is liable to take place in the pan (and thus affect the yield), the temperature may be 165°-170° F. (74°-77° C.). This latter class of soap is generally run direct to the frames and crutched by hand, or, to save manual labour, it may be run into a power-driven crutching pan (neutralising material being added if necessary) and stirred a few times before framing. [Illustration: FIG. 3.--Winch.] [Illustration: FIG. 4.--Soap-boiling pan, showing skimmer pipe, swivel and winch.] [Illustration: FIG. 5.--Hand crutch.] [Illustration: FIG. 6.--Mechanical crutcher.] _Crutching._--This consists of stirring the hot soap in the frames by hand crutches (Fig. 5) until the temperature is sufficiently lowered and the soap begins to assume a "ropiness". Crutching may also be performed mechanically. There are various types of mechanical crutchers, stationary and travelling. They may be cylindrical pans, jacketed or otherwise, in the centre of which is rotated an agitator, consisting of a vertical or horizontal shaft carrying several blades (Fig. 6) or the agitator may take the form of an Archimedean screw working in a cylinder (Fig. 7). [Illustration: FIG. 7.--Mechanical crutcher.] The kind of soap to be crutched, whether thin or stiff, will determine the most suitable type for the purpose. The former class includes "washer" soap which is generally neutralised, and coloured and perfumed, if necessary, in these crutching pans, and in that case they are merely used for mixing the liquids with the hot soap prior to its passage along wooden spouts (Fig. 8) provided with outlets over the frames, in which the crutching is continued by hand. In the case of stiff soaps requiring complete incorporation of liquor, the screw type is preferable, the soap being forced upwards by the screw, and descending between the cylinder and the sides of the pan, while the reverse action can also be brought into play. The completion of crutching is indicated by the smoothness and stiffness of the soap when moved with a trowel, and a portion taken out at this point and cooled should present a rounded appearance. When well mixed the resultant product is emptied directly into wheel-frames placed underneath the outlet of the pan. It is important that the blades or worm of the agitating gear be covered with soap to avoid the occlusion of air and to prevent the soap becoming soft and spongy. [Illustration: FIG. 8.--Wooden soap spout.] _Liquoring of Soaps._--This consists of the addition of various alkaline solutions to soap to produce different qualities, and is best performed in the crutching machines, although it is in some instances carried out in the frames. In the history of soap-making a large number and variety of substances have been suggested for the purpose of accomplishing some real or supposed desirable effect when added to soap. Many of these have had only a very short existence, and others have gradually fallen out of use. Amongst the more practical additions most frequently adopted may be mentioned carbonate of soda, silicate of soda, and pearl ash (impure carbonate of potash). The carbonate of soda may be used in the form of "soda crystals," which, containing 62.9 per cent. of water, dissolves in its own water of crystallisation on heating, and is in that manner added to the hot soap. In the case of weak-bodied soap, this addition gives firmness and tends to increase the detergent qualities. The soda carbonate may also be added to soap as a solution of soda ash (58° alkali) either concentrated, 62° Tw. (34° B.), or of various strengths from 25° Tw. (16° B.) upwards. This solution stiffens and hardens soap, and the addition, which must not be excessive, or efflorescence will occur, is generally made at a temperature of 140° F. (60° C.). Care should always be taken in the choice of solutions for liquoring. Strong soda ash solution with a firm soap will result in a brittle product, whereas the texture of a weak soap would be greatly improved by such addition. A slight addition of a weak solution of pearl ash, 4°-8° Tw. (2.7-5.4° B.), improves the appearance of many soaps intended for household purposes. For yellow soaps, containing a low percentage of fatty acids, solutions of silicate of soda of varying strengths are generally used. It is always advisable to have a test sample made with the soap to ascertain what proportion and what strength of sodium silicate solution is best suited for the grade of soap it is desired to produce. It is important that the soap to be "silicated" should be distinctly alkaline (_i.e._, have a distinct caustic taste), or the resultant soap is liable to become like stone with age. The alkaline silicate of soda (140° Tw., 59.5° B.) is the quality most convenient for yellow soaps; this may be diluted to the desired gravity by boiling with water. For a reduction of 3-4 per cent. fatty acids content, a solution of 6° Tw. (4° B.) (boiling) is most suitable, and if the reduction desired is greater, the density of the silicate solution should be increased; for example, to effect a reduction of 20 per cent. fatty acids content, a solution of 18° Tw. (12° B.) (boiling) would probably be found to answer. In some instances 140° Tw. (59.5° B.) silicate may be added; experiment alone will demonstrate the amount which can be satisfactorily incorporated without the soap becoming "open," but 1/10 of the quantity of soap taken is practically a limit, and it will be found that the temperature should be low; the same quantity of silicate at different temperatures does not produce the same result. Various other strengths of sodium silicate are employed, depending upon the composition and body of the soap base--neutral silicate 75° Tw. (39.4° B.) also finds favour with some soap-makers. Mixtures of soda crystals or soda ash solution with silicate of soda solution are used for a certain grade of soap, which is crutched until smooth and stiff. Glauber's salt (sodium sulphate) produces a good smooth surface when added to soap, but, owing to its tendency to effloresce more quickly than soda carbonate, it is not so much used as formerly. Common salt sometimes forms an ingredient in liquoring mixtures. Potassium chloride and potassium silicate find a limited use for intermixing with soft soaps. It will be readily understood that hard and fast rules cannot be laid down for "liquoring" soap, and the correct solution to be employed can only be ascertained by experiment and experience, but the above suggestions will prove useful as a guide towards good results. A smooth, firm soap of clear, bright, glossy appearance is what should be aimed at. _Filling._--Some low-grade soaps contain filling, which serves no useful purpose beyond the addition of weight. Talc is the most frequently used article of this description. It consists of hydrated silicate of magnesium and, when finely ground, is white and greasy to the touch. The addition of this substance to the hot soap is made by suspending it in silicate of soda solution. Whatever filling material is used, it is important that the appearance of the soap should not be materially altered. _Neutralising, Colouring and Perfuming._--The free caustic alkali in soap, intended for toilet or laundry purposes, is usually neutralised during the cleansing, although some soap manufacturers prefer to accomplish this during the milling operation. Various materials have been recommended for the purpose, those in most general use being sodium bicarbonate, boric acid, cocoa-nut oil, stearic acid, and oleic acid. The best method is the addition of an exact quantity of sodium bicarbonate (acid sodium carbonate), which converts the caustic alkali into carbonate. The reaction may be expressed by the equation:-- NaOH + NaHCO_{3} = Na_{2}CO_{3} + H_{2}O Caustic soda Bicarbonate of soda Carbonate of soda Water Boric acid in aqueous or glycerine solutions, and borax (biborate of soda) are sometimes used, but care is necessary in employing these substances, as any excess is liable to decompose the soap. The addition of cocoa-nut oil is unsatisfactory, the great objection being that complete saponification is difficult to ensure, and, further, there is always the liability of rancidity developing. Stearic and oleic acids are more suitable for the purpose, but oleic acid has the disadvantage that oleates are very liable to go rancid. A large number of other substances have been proposed, and in many instances patented, for neutralising the free caustic alkali. Among these may be mentioned--Alder Wright's method of using an ammoniacal salt, the acid radicle of which neutralises the caustic alkali, ammonia being liberated; the use of sodium and potassium bibasic phosphate (Eng. Pat. 25,357, 1899); a substance formed by treating albumen with formalin (Eng. Pat., 8,582, 1900); wheat glutenin "albuminoses" (albumen after acid or alkaline treatment); malt extract; and egg, milk, or vegetable albumen. The colouring matter used may be of either vegetable or coal-tar origin, and is dissolved in the most suitable medium (lye, water, or fat). The older types of colouring matter--such as cadmium yellow, ochres, vermilion, umbers--have been superseded. In the production of washer household soaps, a small quantity of perfume is sometimes added. _Disinfectant Soaps._--To the soap base, which must be strong to taste, is added from 3 to 4 per cent. of coal-tar derivatives, such as carbolic acid, cresylic acid, creosote, naphthalene, or compounds containing carbolic acid and its homologues. The incorporation is made in the crutching pan, and further crutching may be given by hand in the frames. _Framing._--The object of framing is to allow the soap to solidify into blocks. The frames intended for mottled soaps, which require slow cooling, are constructed of wood, often with a well in the base to allow excess of lye to accumulate--for other soaps, iron frames are in general use. The frame manufactured by H. D. Morgan of Liverpool is shown in Fig. 9. As soon as the frame is filled, or as soon as the crutching in the frame is finished, the soap is smoothed by means of a trowel, leaving in the centre a heap which slopes towards the sides. Next day the top of the soap is straightened or flattened with a wooden mallet, this treatment assisting in the consolidation. [Illustration: FIG. 9.--Soap frame.] [Illustration: FIG. 10.--Slabbing machine.] The length of time the soap should remain in frames is dependent on the quality, quantity, and season or temperature, and varies usually from three to seven days. When the requisite period has elapsed, the sides and ends of the frames are removed, and there remains a solid block of soap weighing from 10 to 15 cwt. according to the size of frame used. The blocks, after scraping and trimming, are ready for cutting into slabs. _Slabbing._--This may be done mechanically by pushing the block of soap through a framework containing pianoforte wires fixed at equi-distances (Fig. 10, which shows a machine designed by E. Forshaw & Son, Ltd.), or the soap may be out by hand by pulling a looped wire through the mass horizontally along lines previously scribed, or, for a standard sized slab, the wire may be a fixture in a box-like arrangement, which is passed along the top of the soap, and the distance of the wire from the top of the box will be the thickness of the slab (Fig. 11). [Illustration: FIG. 11.--Banjo slabber.] All tallow soaps should be slabbed whilst still warm, cut into bars, and open-piled immediately; if this type of soap is cold when slabbed its appearance will be very much altered. _Barring._--The slabs are out transversely into bars by means of the looped wire, or more usually by a machine (Fig. 12), the lower framework of which, containing wires, is drawn through the soap placed on the base-board; the framework is raised, and the bars fall upon the shelf, ready for transference into piles. It has long been the custom in England to cut bars of soap 15 inches long, and weighing 3 lb. each, or 37-1/2 bars of soap to the cwt., but in recent years a demand has arisen for bars of so many various weights that it must be sometimes a difficult matter to know what sizes to stock. In another type of barring machine, portions of the slab, previously cut to size, are pushed against a framework carrying wires, and the bars slide along a table ready for handling (Fig. 13). In cutting machines, through which "washer" household soap is being passed, the bar is pushed at right angles through another frame containing wires, which divides it into tablets; these may be received upon racks and are ready for drying and stamping. It is needless to say that the slabs and tablets are cut with a view to reducing the amount of waste to the lowest possible limit. Such a machine, made by E. Forshaw & Son, Ltd., is shown in Fig. 14. [Illustration: FIG. 12.--Barring machine.] [Illustration: FIG. 13.--Bar-cutting machine.] [Illustration: FIG. 14.--Tablet-cutting machine.] _Open- and Close-piling._--As remarked previously, tallow soaps should be cut whilst warm, and the bars "open-piled," or stacked across each other in such a way that air has free access to each bar for a day. The bar of soap will skin or case-harden, and next day may be "close-piled," or placed in the storage bins, where they should remain for two or three weeks, when they will be in perfect condition for packing into boxes ready for distribution. [Illustration: FIG. 15.--Soap stamp.] _Drying._--"Oil soaps," as soaps of the washer type are termed, do not skin sufficiently by the open-piling treatment, and are generally exposed on racks to a current of hot air in a drying chamber in order to produce the skin, which prevents evaporation of water, and allows of an impression being given by the stamp without the soap adhering to the dies. It is of course understood that heavily liquored soaps are, as a rule, unsuitable for the drying treatment, as the bars become unshapely, and lose water rapidly. _Stamping._--Bar soaps are usually stamped by means of a hand-stamp containing removable or fixed brass letters (Fig. 15), with a certain brand or designation of quality and the name of the manufacturer or vendor, and are now ready for packing into boxes. A very large bulk of the soap trade consists of the household quality in tablet form, readily divided into two cakes. These are stamped in the ordinary box moulds with two dies--top and bottom impressions--the die-plates, being removable, allow the impressions to be changed. This type of mould (Fig. 16) can be adjusted for the compression of tablets of varying thickness, the box preventing the escape of soap. We are indebted to E. Forshaw & Son, Ltd., for this illustration. [Illustration: FIG. 16.--Box mould.] The stamping machine may be worked by hand (Fig. 17) or power driven. Where large quantities of a particular tablet have to be stamped, one of the many automatic mechanical stampers in existence may be employed, the tablets being conveyed to and from the dies by means of endless belts. Such a machine is shown in the accompanying illustration (Fig. 18). If necessary, the soap is transferred to racks and exposed to the air, after which it is ready for wrapping, which is generally performed by manual labour, although in some instances automatic wrapping machines are in use. Cardboard cartons are also used for encasing the wrapped tablets, the object being that these are more conveniently handled by tradesmen and may be advantageously used to form an attractive window display. _Cooling._--Many attempts have been made to shorten the time required for the framing and finishing of soap, by cooling the liquid soap as it leaves the pan. [Illustration: FIG. 17.--Soap-stamping machine, showing box mould.] With milling base, this is successfully accomplished in the Cressonnières' plant, by allowing the hot soap to fall upon the periphery of a revolving drum which can be cooled internally by means of water. [Illustration: FIG. 18.--Automatic stamper.] In the case of household soaps, where the resultant product must be of good appearance and have a firm texture, the difficulty is to produce a bar fit for sale after the cooling has been performed, as soap which has been suddenly chilled lacks the appearance of that treated in the ordinary way. Several patents have been granted for various methods of moulding into bars in tubes, where the hot soap is cooled by being either surrounded by running water in a machine of similar construction to a candle machine, or rotated through a cooling medium; and numerous claims have been made both for mechanical appliances and for methods of removing or discharging the bars after cooling. In many instances these have proved unsatisfactory, owing to fracture of the crystalline structure. Moreover, in passing through some of the devices for solidification after chilling, the soap is churned by means of a worm or screw, and this interferes with the firmness of the finished bar, for, as is well known, soap which has been handled too much, does not regain its former firmness, and its appearance is rendered unsatisfactory. A form of apparatus which is now giving satisfactory results is the Leimdoerfer continuous cooler (Fig. 19). This consists of a fixed charging hopper, A, a portable tank, B, containing tubes, and a detachable box, C, which can be raised or lowered by means of a screw, D. The bottom of the hopper is fitted with holes corresponding with the cooling tubes, _e_, and closed by plugs _c_, attached to a frame _b_, which terminates above in a screw spindle _a_, by means of which the frame and plugs can be raised and lowered so as to permit or stop the outflow of soap into the cooling tubes. The tubes are closed at the bottom by slides _d_, and the box B, in which they are mounted, is carried on a truck running on rails. The charging hopper can be connected with the soap-pan by a pipe, and when the hopper is filled with liquid soap the plugs _c_ are raised and the air in the box C exhausted, thus causing the soap to descend into the cooling tubes. [Illustration: FIG. 19.--Leimdoerfer cooler.] The slides _d_ are closed, the screw D released, and the box B moved away to make room for another. At the end of the rail track is an ejecting device which pushes the cooled soap out of the tubes, and the truck is run back on a side track to the machine for use over again. In this way the apparatus can be worked continuously, the soap being received from the cooling pipes on a suitable arrangement for transport to the press or store room. A similar idea has been made the subject of a patent by Holoubek (Eng. Pat. 24,440, 1904, Fig. 20). The soap is run into frames or moulds having open sides, which are closed by being clamped with screws and pressure plates between cooling tubes through which water circulates. [Illustration: FIG. 20.--Holoubek's cooler.] CHAPTER VII. TOILET, TEXTILE AND MISCELLANEOUS SOAPS. _Toilet Soaps--Cold Process Soaps--Settled Boiled Soaps--Remelted Soaps--Milled Soaps--Drying--Milling and Incorporating Colour, Perfume, or Medicament--Perfume--Colouring Matter--Neutralising and Superfatting Material--Compressing--Cutting--Stamping--Medicated Soaps--Ether Soap--Floating Soaps--Shaving Soaps--Textile Soaps--Soaps for Woollen, Cotton and Silk Industries--Patent Textile Soaps--Miscellaneous Soaps._ _Toilet Soaps._--By the term "toilet soap" is inferred a soap specially adapted for toilet use by reason not only of its good detergent and lathering qualities, but also on account of its freedom from caustic alkali and any other ingredient likely to cause irritation or injury to the skin. Toilet soaps may be simply classified according to their method of preparation into the following four classes:-- (1) Cold process soaps. (2) Settled boiled soaps. (3) Remelted soaps. (4) Milled soaps. Soaps of the first class are of comparatively trifling importance, having been superseded by the other qualities. Details of the "cold process" have already been given on page 46; it is only necessary to add the desired perfume and colouring matter to the soap. The second class consists of good quality settled soaps, direct from the copper, to which have been added, prior to framing, suitable perfume and colouring matter, also, if necessary, dealkalising materials. The third class is represented by soaps made by the old English method of remelting, which are often termed "perfumers'," or "little pan" soaps. The soap-base or mixture of various kinds of soap is remelted in a steam-jacketed pan, or pan provided with steam coils, and agitated. The agitation must not be too vigorous or lengthy, or the soap will become aerated. When all the soap is molten, additions of pearl ash solution are made to give it a finer and smoother texture, render it more transparent, and increase its lathering properties. The necessary colour, in a soluble form, is well incorporated, and lastly the perfume. Owing to volatilisation, much of the perfume is lost when added to hot soap, and it is necessary to add a large quantity to get the desired odour; hence the cheaper essential oils have to be used, so that the perfume of this class of soap is not so delicate as that of milled soaps, although it is quite possible to produce remelted soaps as free from uncombined alkali as a milled toilet soap. Palm-oil soap often forms the basis for yellow and brown toilet soaps of this class. The old-fashioned Brown Windsor soap was originally a curd soap that with age and frequent remelting had acquired a brown tint by oxidation of the fatty acids--the oftener remelted the better the resultant soap. Medicaments are sometimes added to these soaps, _e.g._, camphor, borax, coal-tar, or carbolic. Oatmeal and bran have been recommended in combination with soap for toilet purposes, and a patent (Eng. Pat. 26,396, 1896) has been granted for the use of these substances together with wood-fibre impregnated with boric acid. After cooling in small frames, the soap is slabbed, and cut into blocks, and finally into portions suitable for stamping in a press (hand or steam driven) with a design or lettering on each side. _Milled Toilet Soaps._--Practically all high-class soaps now on the market pass through the French or milling process. This treatment, as its name implies, was first practised by the French who introduced it to this country, and consists briefly of (i.) drying, (ii.) milling and incorporating colour, perfume or medicament, (iii.) compressing, and (iv.) cutting and stamping. The advantages of milled soap over toilet soap produced by other methods are that the former, containing less water and more actual soap, is more economical in use, possesses a better appearance, and more elegant finish, does not shrink or lose its shape, is more uniform in composition, and essential oils and delicate perfumes may be incorporated without fear of loss or deterioration. Only soap made from best quality fats is usually milled, a suitable base being that obtained by saponifying a blend of the finest white tallow with a proportion, not exceeding 25 per cent., of cocoa-nut oil, and prepared as described in Chapter V. The first essential of a milling base is that the saponification should be thorough and complete; if this is not ensured, rancidity is liable to occur and a satisfactory toilet soap cannot be produced. The soap must not be short in texture or brittle and liable to split, but of a firm and somewhat plastic consistency. (i.) _Drying._--The milling-base, after solidification in the frames, contains almost invariably from 28 to 30 per cent. of water, and this quantity must be reduced to rather less than half before the soap can be satisfactorily milled. Cutting the soap into bars or strips and open piling greatly facilitates the drying, which is usually effected by chipping the soap and exposing it on trays to a current of hot air at 95-105° F. (35-40° C.). There are several forms of drying chambers in which the trays of chips are placed upon a series of racks one above another, and warm air circulated through, and Fig. 21 shows a soap drying apparatus with fan made by W. J. Fraser & Co., Ltd., London. The older method of heating the air by allowing it to pass over a pipe or flue through which the products of combustion from a coke or coal fire are proceeding under the floor of the drying chamber to a small shaft, has been superseded by steam heat. The air is either drawn or forced by means of quickly revolving fans through a cylinder placed in a horizontal position and containing steam coils, or passed over steam-pipes laid under the iron grating forming the floor of the chamber. [Illustration: FIG. 21.--Soap-drying apparatus.] It will be readily understood that in the case of a bad conductor of heat, like soap-chippings, it is difficult to evaporate moisture without constantly moving them and exposing fresh surfaces to the action of heat. In the Cressonnières' system, where the shavings of chilled soap are dried by being carried through a heated chamber upon a series of endless bands (the first discharging the contents on to a lower belt which projects at the end, and is moving in the opposite direction, and so on), this is performed by intercepting milling rollers in the system of belts (Eng. Pat. 4,916, 1898) whereby the surfaces exposed to the drying are altered, and it is claimed that the formation of hardened crust is prevented. In the ordinary methods of drying, the chips are frequently moved by hand to assist uniform evaporation. The degree of saturation of the air with moisture must be taken into consideration in regulating the temperature and flow of air through the drying chamber, and for this purpose the use of a hygrometer is advantageous. It is very important that the correct amount of moisture should be left in the soap, not too much, nor too little; the exact point can only be determined by judgment and experience, and depends to a considerable extent upon the nature of the soap, and also on the amount of perfume or medicament to be added, but speaking generally, a range of 11 to 14 per cent. gives good results. If the soap contains less than this amount it is liable to crumble during the milling, will not compress satisfactorily, and the finished tablet may have a tendency to crack and contain gritty particles so objectionable in use. If, on the other hand, the soap is left too moist, it is apt to stick to the rollers and mill with difficulty, and during compression the surface assumes a blistered and sticky appearance. (ii.) _Milling and Incorporation of Colour, Perfume or Medicament._--The object of milling is to render the soap perfectly homogeneous, and to reduce it to a state in which colour, perfume, or any necessary neutralising material or other substance may be thoroughly incorporated. The milling machine consists of smooth granite rollers, fitted with suitable gearing and working in an iron framework (Fig. 22). The rollers are connected in such a manner that they rotate at different speeds, and this increases the efficiency of the milling, and ensures that the action of the rollers is one of rubbing rather than crushing. By means of suitably arranged screws the pressure of the rollers on one another can be adjusted to give the issuing soap any desired thickness; care should be taken that the sheets of soap are not unnecessarily thick or the colour and odour will not be uniform. The soap, in the form of chips, is introduced on to the rollers through a hopper, and after one passage through the mill, from bottom to top, one of the serrated knife edges is applied and the ribbons of the soap are delivered into the top of the hopper where the colour, perfume, and any other desired admixture is added, and the milling operation repeated three or four times. When the incorporation is complete the other scraper is fixed against the top roller and the soap ribbon passed into the receptacle from which it is conveyed to the compressor. A better plan, however, especially in the case of the best grade soaps, where the perfumes added are necessarily more delicate and costly, is to make the addition of the perfume when the colour has been thoroughly mixed throughout the mass. Another method is to mill once and transfer the mass to a rotary mixing machine, fitted with internal blades, of a peculiar form, which revolve in opposite directions one within the other as the mixer is rotated. The perfume, colouring matter, etc., are added and the mixer closed and set in motion, when, after a short time, the soap is reduced to a fine granular condition, with the colour and perfume evenly distributed throughout the whole. By the use of such machines, the loss of perfume by evaporation, which during milling is quite appreciable, is reduced to a minimum, and the delicacy of the aroma is preserved unimpaired. [Illustration: FIG. 22.--Milling machine.] Prolonged milling, especially with a suitable soap base, tends to produce a semi-transparent appearance, which is admired by some, but the increased cost of production by the repeated milling is not accompanied by any real improvement in the soap. _Perfume._--The materials used in perfuming soap will be dealt with fully in the next chapter. The quantity necessary to be added varies considerably with the nature of the essential oils, and also the price at which the soap is intended to be sold. In the cheaper grades of milled soaps the quantity will range from 10-30 fluid ozs. per cwt., and but rarely exceeds 18-20 ozs., whereas in more costly soaps as much as 40-50 fluid ozs. are sometimes added to the cwt. _Colouring Matter._--During recent years an outcry has been made against highly coloured soaps, and the highest class soaps have been manufactured either colourless or at the most with only a very delicate tint. It is obvious that a white soap guarantees the use of only the highest grade oils and fats, and excludes the introduction of any rosin, and, so far, the desire for a white soap is doubtless justified. Many perfumes, however, tend to quickly discolour a soap, hence the advantage of giving it a slight tint. For this purpose a vegetable colouring matter is preferable, and chlorophyll is very suitable. [Illustration: FIG. 23.--Compressor.] A demand still exists for brightly coloured soaps, and this is usually met by the use of coal-tar dyes. The quantity required is of course extremely small, so that no harm or disagreeable result could possibly arise from their use. _Neutralising and Superfatting Material._--If desired, the final neutralisation of free alkali can be carried out during the milling process, any superfatting material being added at the same time. The chief neutralising reagents have already been mentioned in Chapter VI. With regard to superfatting material, the quantity of this should be very small, not exceeding 6-8 ozs. per cwt: The most suitable materials are vaseline, lanoline, or spermaceti. [Illustration: FIG. 24--Hand soap-stamping press.] (iii.) _Compressing._--The next stage is the compression and binding of the soap ribbons into a solid bar suitable for stamping, and the plant used (Fig. 23) for this purpose is substantially the same in all factories. The soap is fed through a hopper into a strong metal conical-shaped tube like a cannon, which tapers towards the nozzle, and in which a single or twin screw is moving, and the soap is thereby forced through a perforated metallic disc, subjected to great pressure, and compressed. The screws must be kept uniformly covered with shavings during compression to obviate air bubbles in the soap. [Illustration: FIG. 25.--Screw press.] The soap finally emerges through the nozzle (to which is attached a cutter of suitable shape and size according to the form it is intended the final tablet to take) as a long, polished, solid bar, which is cut with a knife or wire into lengths of 2 or 3 feet, and if of satisfactory appearance, is ready for cutting and stamping. The nozzle of the plodder is heated by means of a Bunsen burner to about 120° or 130° F. (49°-55° C.) to allow the soap to be easily forced out, and this also imparts a good gloss and finish to the ejected bar--if the nozzle is too hot, however, the soap will be blistered, whereas insufficient heat will result in streaky soap of a poor and dull appearance. (iv.) _Cutting and Stamping._--In cutting the soap into sections for stamping, the cutter should shape it somewhat similar to the required finished tablet. Many manufacturers cut the soap into sections having concave ends, and in stamping, the corners are forced into the concavity, with the result that unsightly markings are produced at each end of the tablet. It is preferable to have a cutter with convex ends, and if the stamping is to be done in a pin mould the shape should be a trifle larger than the exact size of the desired tablet. [Illustration: FIG. 26--Pin mould.] The stamping may be performed by a hand stamper (Fig. 24), a screw press (Fig. 25), or by a steam stamper. The screw press works very satisfactorily for toilet soaps. There are two kinds of moulds in use for milled soaps:-- (_a_) _Pin Moulds_ in which tablets of one size and shape only can be produced (Fig. 25). The edges of the mould meet very exactly, the upper part of the die carries two pins attached to the shoulder, and these are received into two holes in the shoulder of the bottom plate. The superfluous soap is forced out as the dies meet. (_b_) _Band or Collar Moulds._--In this form (Fig, 27) the mould may be adjusted to stamp various sized tablets, say from 2 ozs. to 5-1/3 ozs. and different impressions given by means of removable die plates. The band or collar prevents the soap squeezing out sideways. We are indebted to R. Forehaw & Son, Ltd., for the loan of this illustration. It is usual to moisten the soap or mould with a dilute solution of glycerine if it should have a tendency to stick to the die plates. The soap is then ready for final trimming, wrapping, and boxing. [Illustration: FIG. 27--Band Mould.] MEDICATED SOAPS. The inherent cleansing power of soap renders it invaluable in combating disease, while it also has distinct germicidal properties, a 2 per cent. solution proving fatal to B. coli communis in less than six hours, and even a 1 per cent. solution having a marked action on germs in fifteen minutes. Many makers, however, seek more or less successfully to still further increase the value of soap in this direction by the incorporation of various drugs and chemicals; and the number of medicated soaps on the market is now very large. Such soaps may consist of either hard or soft soaps to which certain medicaments have been added, and can be roughly divided into two classes, (_a_) those which contain a specific for various definite diseases, the intention being that the remedy should be absorbed by the pores of the skin and thus penetrate the system, and (_b_) those impregnated with chemicals intended to act as antiseptics or germicides, or, generally, as disinfectants. The preparation of medicinal soaps appears to have been first taken up in a scientific manner by Unna of Hamburg in 1886, who advocated the use of soap in preference to plasters as a vehicle for the application of certain remedies. Theoretically, he considered a soap-stock made entirely from beef tallow the most suitable for the purpose, but in practice found that the best results were obtained by using a superfatted soap made from a blend of one part of olive oil with eight parts of beef tallow, saponified with a mixture of two parts of soda to one part of potash, sufficient fat being employed to leave an excess of 3 or 4 per cent. unsaponified. Recent researches have shown, however, that even if a superfatted soap-base is beneficial for the preparation of toilet soaps (a point which is open to doubt), it is quite inadmissible for the manufacture of germicidal and disinfectant soaps, the bactericidal efficiency of which is much restricted by the presence of free fat. Many of the medicaments added to soaps require special methods of incorporation therein, as they otherwise react with the soap and decompose it, forming comparatively inert compounds. This applies particularly to salts of mercury, such as _corrosive sublimate_ or mercuric chloride, and _biniodide of mercury_, both of which have very considerable germicidal power, and are consequently frequently added to soaps. If simply mixed with the soap in the mill, reaction very quickly takes place between the mercury salt and the soap, with formation of the insoluble mercury compounds of the fatty acids, a change which can be readily seen to occur in such a soap by the rapid development on keeping, of a dull slaty-green appearance. Numerous processes have been suggested, and in some cases patented, to overcome this difficulty. In the case of corrosive sublimate, Geissler suggested that the soap to which this reagent is to be added should contain an excess of fatty acids, and would thereby be rendered stable. This salt has also been incorporated with milled soap in a dry state in conjunction with ammonio-mercuric chloride, [beta]-naphthol, methyl salicylate, and eucalyptol. It is claimed that these bodies are present in an unchanged condition, and become active when the soap is added to water as in washing. Ehrhardt (Eng. Pat. 2,407, 1898) patented a method of making antiseptic mercury soap by using mercury albuminate--a combination of mercuric chloride and casein, which is soluble in alkali, and added to the soap in an alkaline solution. With biniodide of mercury the interaction can be readily obviated by adding to the biniodide of mercury an equal weight of potassium iodide. This process, devised and patented by J. Thomson in 1886, has been worked since that time with extremely satisfactory results. Strengths of 1/2, 1, and 3 per cent. biniodide are sold, but owing to the readiness with which it is absorbed by the skin a soap containing more than 1/2 per cent. should only be used under medical advice. A similar combination of _bromide of mercury_ with potassium, sodium, or ammonium bromide has recently been patented by Cooke for admixture with liquid, hard, or soft soaps. _Zinc and other Metallic Salts._--At various times salts of metals other than mercury have been added to soap, but, owing to their insolubility in water, their efficiency as medicaments is very trifling or nil. Compounds have been formed of metallic oxides and other salts with oleic said, and mixtures made with vaseline and lanoline, and incorporated with soap, but they have not met with much success. Another chemical commonly added to soap is _Borax_. In view of its alkaline reaction to litmus, turning red litmus blue, this salt is no doubt generally regarded as alkaline, and, as such, without action on soap. On the contrary, however, it is an acid salt containing an excess of boric acid over the soda present, hence when it is added to soap, fatty acids are necessarily liberated, causing the soap to quickly become rancid. As a remedy for this it has been proposed to add sufficient alkali to convert the borax into neutral mono-borate of soda which is then added to the soap. This process is patented and the name "Kastilis" has been given to the neutral salt. The incorporation of borax with the addition of gum tragasol forms the subject of two patents (Eng. Pats. 4,415, 1904; and 25,425, 1905); increased detergent and lasting properties are claimed for the soap. Another patented process (Eng. Pat. 17,218, 1904) consists of coating the borax with a protective layer of fat or wax before adding to the soap with the idea that reaction will not take place until required. _Boric acid_ possesses the defects of borax in a greater degree, and would, of course, simply form sodium borate with liberation of fatty acids, so should never be added to a neutral soap. _Salicylic Acid_ is often recommended for certain skin diseases, and here again the addition of the acid to soap under ordinary conditions results in the formation of sodium salicylate and free fatty acids. To overcome this a process has recently been patented for rubbing the acid up with vaseline before addition to soap, but the simplest way appears to be to add the soda salt of the acid to soap. Amongst the more common milled medicated toilet soaps may be mentioned, in addition to the above:-- _Birch Tar Soap_, containing 5 or 10 per cent. birch tar, which has a characteristic pungent odour and is recommended as a remedy for eczema and psoriasis. _Carbolic Soap._--A toilet soap should not contain more than 3 per cent. of pure phenol, for with larger quantities irritation is likely to be experienced by susceptible skins. _Coal Tar._--These soaps contain, in addition to carbolic acid and its homologues, naphthalene and other hydrocarbons derived from coal, naphthol, bases, etc. Various blends of different fractions of coal tar are used, but the most valuable constituents from a disinfectant point of view are undoubtedly the phenols, or tar acids, though in this case as with carbolic and cresylic soaps, the amount of phenols should not exceed 3 per cent. in a toilet soap. An excess of naphthalene should also be avoided, since, on account of its strong odour, soaps containing much of it are unpopular. The odour of coal tar is considerably modified by and blends well with a perfume containing oils of cassia, lavender, spike, and red thyme. _Formaldehyde._--This substance is one of the most powerful disinfectants known, and it may be readily introduced into soap without undergoing any decomposition, by milling in 2-3 per cent. of formalin, a 40 per cent. aqueous solution of formaldehyde, which is a gas. White soaps containing this chemical retain their whiteness almost indefinitely. New combinations of formaldehyde with other bodies are constantly being brought forward as disinfectants. Among others the compound resulting from heating lanoline with formaldehyde has been patented (Eng. Pat. 7,169, 1898), and is recommended as an antiseptic medicament for incorporation with soap. _Glycerine._--Nearly all soaps contain a small quantity of this body which is not separated in the lyes. In some cases, however, a much larger quantity is desired, up to some 6 or 8 per cent. To mill this in requires great care, otherwise the soap tends to blister during compression. The best way is to dry the soap somewhat further than usual, till it contains say only 9 or 10 per cent. moisture and then mill in the glycerine. _Ichthyol_ or _Ammonium-Ichthyol-Sulphonate_ is prepared by treating with sulphuric acid, and afterwards with ammonia, the hydrocarbon oil containing sulphur obtained by the dry distillation of the fossil remains of fish and sea-animals, which form a bituminous mineral deposit in Germany. This product has been admixed with soap for many years, the quantity generally used being about 5 per cent.; the resultant soap is possessed of a characteristic empyreumatic smell, very dark colour, and is recommended for rosacea and various skin diseases, and also as an anti-rheumatic. Ichthyol has somewhat changed its character during recent years, being now almost completely soluble in water, and stronger in odour than formerly. _Iodine._--A soap containing iodine is sometimes used in scrofulous skin diseases. It should contain some 3 per cent. iodine, while potassium iodide should also be added to render the iodine soluble. _Lysol._--This name is applied to a soap solution of cresol, "Lysol Soap" being simply another form of coal-tar soap. The usual strength is 10 per cent. lysol, and constitutes a patented article (Fr. Pat. 359,061, 1905). _Naphthol._--[beta]-Naphthol, also a coal-tar derivative, is a good germicide, and, incorporated in soap to the extent of 3 per cent. together with sulphur, is recommended for scabies, eczema and many other cutaneous affections. _Sulphur._--Since sulphur is insoluble in water, its action when used in conjunction with soap can be but very slow and slight. Sulphur soaps are, however, very commonly sold, and 10 per cent. is the strength usually advocated, though many so-called sulphur soaps actually contain very little sulphur. They are said to be efficacious for acne and rosacea. Sulphur soaps, when dissolved in water, gradually generate sulphuretted hydrogen, which, although characteristic, makes their use disagreeable and lessens their popular estimation. _Terebene._--The addition of this substance to soap, though imparting a very refreshing and pleasant odour, does not materially increase the disinfectant value of the soap. A suitable strength is 5 per cent. _Thymol._--This furnishes a not unpleasant, and very useful antiseptic soap, recommended especially for the cleansing of ulcerated wounds and restoring the skin to a healthy state. The normal strength is 3 per cent. It is preferable to replace part of the thymol with red thyme oil, the thymene of which imparts a sweeter odour to the soap than if produced with thymol alone. A suitable blend is 2-1/2 per cent. of thymol crystals and 1-1/2 per cent. of a good red thyme oil. Of the vast number of less known proposed additions to toilet soaps, mention may be made in passing of:-- _Fluorides._--These have been somewhat popular during recent years for the disinfection of breweries, etc., and also used to some extent as food preservatives. Of course only neutral fluorides are available for use in soap, acid fluorides and soap being obviously incompatible. In the authors' experience, however, sodium fluoride appears to have little value as a germicide when added to soap, such soaps being found to rapidly become rancid and change colour. _Albumen._--The use of albumen--egg, milk, and vegetable--in soap has been persistently advocated in this country during the past few years. The claims attributed to albumen are, that it neutralises free alkali, causes the soap to yield a more copious lather, and helps to bind it more closely, and a further inducement held out is that it allows more water to be left in the soap without affecting its firmness. Experiments made by the authors did not appear to justify any enthusiasm on the subject, and the use of albumen for soap-making in this country appears to be very slight, however popular it may be on the Continent. Numerous other substances have been proposed for addition to soaps, including yeast, tar from peat (sphagnol), Swedish wood tar, permanganate of potash, perborates and percarbonates of soda and ammonia, chlorine compounds, but none of these has at present come much into favour, and some had only ephemeral existence. Of the many drugs that it has been suggested to admix in soap for use in allaying an irritable condition of the skin, the majority are obviously better applied in the form of ointments, and we need not consider them further. _Ether Soap._--Another form of medicated soap made by a few firms is a liquid ether soap containing mercuric iodide, and intended for surgeons' use. This, as a rule, consists of a soap made from olive oil and potash, dissolved in alcohol and mixed with ether, the mercuric iodide being dissolved in a few drops of water containing an equal weight of potassium iodide, and this solution added to the alcohol-ether soap. _Floating Soaps._--Attempts have been made to produce tablets of soap that will float upon the surface of water, by inserting cork, or floats, or a metallic plate in such a manner that there is an air space between the metal and the soap. The more usual method is to incorporate into hot soap sufficient air, by means of a specially designed self-contained jacketed crutcher, in which two shafts carrying small blades or paddles rotate in opposite directions, to reduce the density of the soap below that of water and so enable the compressed tablet to float. The difference in weight of a tablet of the same size before and after aerating amounts to 10 per cent. Ordinary milling soap is used as a basis for this soap; the settled soap direct from the copper at 170° F. (77° C.) is carefully neutralised with bicarbonate of sodium, oleic or stearic acids, or boro-glyceride, perfumed and aerated. Floating soap, which is usually white (some are of a cream tint), cannot be recommended as economical, whilst its deficiency in lathering properties, owing to occluded air, is a serious drawback to its popularity as a toilet detergent. _Shaving Soaps._--The first essential of a shaving soap, apart from its freedom from caustic alkali or any substance exerting an irritating effect upon the skin, is the quick production of a profuse creamy lather which is lasting. Gum tragacanth is used in some cases to give lasting power or durability, but is not necessary, as this property is readily attained by the use of a suitable proportion of potash soap. The best shaving soaps are mixtures of various proportions of neutral soda and potash soaps, produced by the combination of ordinary milling base with a white potash soap, either melted or milled together. Glycerine is sometimes added, and is more satisfactorily milled in. Every precaution should be taken to ensure thorough saponification of the soaps intended for blending in shaving soap, otherwise there will be a tendency to become discoloured and develop rancidity with age. Shaving soaps are delicately perfumed, and are placed on the market either in the form of sticks which are cut from the bar of soap as it leaves the compressor, or stamped in flat cakes. Shaving creams and pastes are of the same nature as shaving soaps, but usually contain a larger proportion of superfatting material and considerably more water. TEXTILE SOAPS. In the woollen, cloth, and silk textile industries, the use of soap for detergent and emulsifying purposes is necessary in several of the processes, and the following is a brief description of the kinds of soap successfully employed in the various stages. 1. _Woollen Industry._--The scouring of wool is the most important operation--it is the first treatment raw wool is subjected to, and if it is not performed in an efficient manner, gives rise to serious subsequent troubles to manufacturer, dyer, and finisher. The object of scouring wool is to remove the wool-fat and wool perspiration (exuded from the skin of sheep), consisting of cholesterol and isocholesterol, and potassium salts of fatty acids, together with other salts, such as sulphates, chlorides, and phosphates. This is effected by washing in a warm dilute soap solution, containing in the case of low quality wool, a little carbonate of soda; the fatty matter is thereby emulsified and easily removed. Soap, to be suitable for the purpose, must be free from uncombined caustic alkali, unsaponified fat, silicates, and rosin. Wool can be dissolved in a moderately dilute solution of caustic soda, and the presence of this latter in soap, even in small quantities, is therefore liable to injure the fibres and make the resultant fabric possess a harsh "feel," and be devoid of lustre. Unsaponified fat denotes badly made soap--besides reducing the emulsifying power of the liberated alkali, this fat may be absorbed by the fibres and not only induce rancidity but also cause trouble in dyeing. Soaps containing silicates may have a deleterious action upon the fibres, causing them to become damaged and broken. By general consent soaps containing rosin are unsuitable for use by woollen manufacturers, as they produce sticky insoluble lime and magnesia compounds which are deposited upon the fibres, and give rise to unevenness in the dyeing. A neutral olive-oil soft soap is undoubtedly the best for the purpose of wool scouring, as, owing to its ready solubility in water, it quickly penetrates the fibres, is easily washed out, and produces a good "feel" so essential in the best goods, and tends to preserve the lustre and pliability of the fibre. The high price of olive-oil soap, however, renders its use prohibitive for lower class goods, and in such cases no better soap can be suggested than the old-fashioned curd mottled or curd soaps (boiled very dry), as free as possible from uncombined caustic alkali. The raw wool, after this cleansing operation, is oiled with olive oil or oleine, prior to spinning; after spinning and weaving, the fabric, in the form of yarn or cloth, has to be scoured to free it from oil. The soap in most general use for scouring woollen fabrics is neutral oleine-soda soap. Some manufacturers prefer a cheap curd soap, such as is generally termed "second curd," and in cases where lower grades of wools are handled, the user is often willing to have soap containing rosin (owing to its cheapness) and considers a little alkalinity desirable to assist in removing the oil. Another operation in which soap is used, is that of milling or fulling, whereby the fabric is made to shrink and thus becomes more compact and closer in texture. The fabric is thoroughly cleansed, for which purpose the soap should be neutral and free from rosin and silicates, otherwise a harsh feeling or stickiness will be produced. Curd soaps or finely-fitted soaps made from tallow or bleached palm oil, with or without the addition of cocoa-nut oil, give the best results. All traces of soap must be carefully removed if the fabric is to be dyed. The woollen dyer uses soap on the dyed pieces to assist the milling, and finds that a good soap, made from either olive oil, bleached palm oil, or tallow, is preferable, and, although it is generally specified to be free from alkali, a little alkalinity is not of consequence, for the woollen goods are, as a rule, acid after dyeing, and this alkalinity would be instantly neutralised. 2. _Cotton Industry._--Cotton fibres are unacted upon by caustic alkali, so that the soap used in cleaning and preparing cotton goods for dyeing need not be neutral, in fact alkalinity is a distinct advantage in order to assist the cleansing. Any curd soap made from tallow, with or without the addition of a small quantity of cocoa-nut oil, may be advantageously used for removing the natural oil. In cotton dyeing, additions of soap are often made to the bath, and in such cases the soap must be of good odour and neutral, lest the colours should be acted upon and tints altered. Soaps made from olive oil and palm oil are recommended. The same kind of soap is sometimes used for soaping the dyed cotton goods. The calico-printer uses considerable quantities of soap for cleansing the printed-cloths. The soap not only cleanses by helping to remove the gummy and starchy constituents of the adhering printing paste, but also plays an important part in fixing and brightening the colours. Soaps intended for this class of work must be quite neutral (to obviate any possible alteration in colour by the action of free alkali), free from objectionable odour and rosin, and readily soluble in water. These qualities are possessed by olive-oil soaps, either soft or hard. A neutral olive-oil soft soap, owing to its solubility in cold water, may be used for fibres coloured with most delicate dyes, which would be fugitive in hot soap solutions, and this soap is employed for the most expensive work. Olive-oil curd (soda) soaps are in general use; those made from palm oil are also recommended, although they are not so soluble as the olive-oil soaps. Tallow curd soaps are sometimes used, but the difficulty with which they dissolve is a drawback, and renders them somewhat unsuitable. 3. _Silk Industry._--Silk is secured to remove the sericin or silk-glue and adhering matter from the raw silk, producing thereby lustre on the softened fibre and thus preparing it for the dyer. The very best soap for the purpose is an olive-oil soft soap; olive-oil and oleine hard soaps may also be used. The soap is often used in conjunction with carbonate of soda to assist the removal of the sericin, but, whilst carbonates are permissible, it is necessary to avoid an excess of caustic soda. Tallow soaps are so slowly soluble that they are not applicable to the scouring of silk. The dyer of silk requires soap, which is neutral and of a pleasant odour. The preference is given to neutral olive-oil soft soap, but hard soaps (made from olive oil, oleine, or palm oil) are used chiefly on account of cheapness. It is essential, however, that the soap should be free from rosin on account of its frequent use and consequent decomposition in the acid dye bath, when any liberated rosin acids would cling to the silk fibres and produce disagreeable results. _Patent Textile Soaps._--Stockhausen (Eng. Pat. 24,868, 1897) makes special claim for a soap, termed Monopole Soap, to be used in place of Turkey-red oils in the dyeing and printing of cotton goods and finishing of textile fabrics. The soap is prepared by heating the sulphonated oil (obtained on treatment of castor oil with sulphuric acid) with alkali, and it is stated that the product is not precipitated when used in the dye-bath as is ordinary soap, nor is it deposited upon the fibres. Another patent (Eng. Pat. 16,382, 1897), has for its object the obviating of the injurious effects upon wool, of alkali liberated from a solution of soap. It is proposed to accomplish this by sulphonating part of the fat used in making the soap. _Miscellaneous Soaps._--Under this heading may be classed soaps intended for special purposes and consisting essentially of ordinary boiled soap to which additions of various substances have been made. With additions of naphtha, fractions of petroleum, and turpentine, the detergent power of the soap is increased by the action of these substances in removing grease. Amongst the many other additions may be mentioned: ox-gall or derivatives therefrom (for carpet-cleaning soap), alkali sulphides (for use of lead-workers), aniline colours (for home-dyeing soaps), pumice and tripoli (motorists' soaps), pine-needle oil, in some instances together with lanoline (for massage soaps), pearl-ash (for soap intended to remove oil and tar stains), magnesia, rouge, ammonium carbonate, chalk (silversmiths' soap), powdered orris, precipitated chalk, magnesium carbonate (tooth soaps). Soap powders or dry soaps are powdered mixtures of soap, soda ash, or soda crystals, and other chemicals, whilst polishing soaps often contain from 85 to 90 per cent. siliceous matter, and can scarcely be termed soap. CHAPTER VIII. SOAP PERFUMES. _Essential Oils--Source and Preparation--Properties--Artificial and Synthetic Perfumes._ The number of raw materials, both natural and artificial, at the disposal of the perfumer, has increased so enormously during recent years that the scenting of soaps has now become an art requiring very considerable skill, and a thorough knowledge of the products to be handled. Not only does the all-important question of odour come into consideration, but the action of the perfumes on the soap, and on each other, has also to be taken into account. Thus, many essential oils and synthetic perfumes cause the soap to darken rapidly on keeping, _e.g._, clove oil, cassia oil, heliotropin, vanillin. Further, some odoriferous substances, from their chemical nature, are incompatible with soap, and soon decompose any soap to which they are added, while in a few cases, the blending of two unsuitable perfumes results, by mutual reaction, in the effect of each being lost. In the case of oils like bergamot oil, the odour value of which depends chiefly on their ester content, it is very important that these should not be added to soaps containing much free alkali, as these esters are readily decomposed thereby. Some perfumes possess the property of helping the soap to retain other and more delicate odours considerably longer than would otherwise be possible. Such perfumes are known as "fixing agents" or "fixateurs," and among the most important of these may be mentioned musk, both natural and artificial, civet, the oils of Peru balsam, sandalwood, and patchouli, and benzyl benzoate. The natural perfumes employed for addition to soaps are almost entirely of vegetable origin, and consist of essential oils, balsams, and resins, animal perfumes such as musk, civet, and ambergris being reserved principally for the preparation of "extraits". As would be expected with products of such diverse character, the methods employed for the preparation of essential oils vary considerably. Broadly speaking, however, the processes may be divided into three classes--(1) _expression_, used for orange, lemon, and lime oils; (2) _distillation_, employed for otto of rose, geranium, sandalwood, and many other oils; and (3) _extraction_, including _enfleurage_, by which the volatile oil from the flowers is either first absorbed by a neutral fat such as lard, and then extracted therefrom by maceration in alcohol, or directly extracted from the flowers by means of a volatile solvent such as benzene, petroleum ether, or chloroform. The last process undoubtedly furnishes products most nearly resembling the natural floral odours, and is the only one which does not destroy the delicate fragrance of the violet and jasmine. The yield, however, is extremely small, and concrete perfumes prepared in this way are therefore somewhat costly. The essential oils used are derived from upwards of twenty different botanical families, and are obtained from all parts of the world. Thus, from Africa we have geranium and clove oils; from America, bay, bois de rose, Canadian snake root, cedarwood, linaloe, peppermint, petitgrain, and sassafras; from Asia, camphor, cassia, cinnamon, patchouli, sandalwood, star anise, ylang-ylang, and the grass oils, _viz._, citronella, lemongrass, palmarosa, and vetivert; from Australia, eucalyptus; while in Europe there are the citrus oils, bergamot, lemon, and orange, produced by Sicily, aspic, lavender, neroli, petitgrain, and rosemary by France, caraway and clove by Holland, anise by Russia, and otto of rose by Bulgaria. Attempts have been made to classify essential oils either on a botanical basis or according to their chemical composition, but neither method is very satisfactory, and, in describing the chief constituents and properties of the more important oils, we have preferred therefore to arrange them alphabetically, as being simpler for reference. It is a matter of some difficulty to judge the purity of essential oils, not only because of their complex nature, but owing to the very great effect upon their properties produced by growing the plants in different soils and under varying climatic conditions, and still more to the highly scientific methods of adulteration adopted by unscrupulous vendors. The following figures will be found, however, to include all normal oils. _Anise Stell_, or _Star Anise_, from the fruit of Illicium verum, obtained from China. Specific gravity at 15° C., 0.980-0.990; optical rotation, faintly dextro- or lævo-rotatory, +0° 30' to -2°; refractive index at 20° C., 1.553-1.555; solidifying point, 14°-17° C.; solubility in 90 per cent. alcohol, 1 in 3 or 4. The chief constituents of the oil are anethol, methyl chavicol, d-pinene, l-phellandrene, and in older oils, the oxidation products of anethol, _viz._ anisic aldehyde and anisic acid. Since anethol is the most valuable constituent, and the solidifying point of the oil is roughly proportional to its anethol content, oils with a higher solidifying point are the best. _Aspic oil_, from the flowers of Lavandula spica, obtained from France and Spain, and extensively employed in perfuming household and cheap toilet soaps; also frequently found as an adulterant in lavender oil. Specific gravity at 15° C., 0.904-0.913; optical rotation, French, dextro-rotatory up to +4°, rarely up to +7°, Spanish, frequently slightly lævo-rotatory to -2°, or dextro-rotatory up to +7°; esters, calculated as linalyl acetate, 2 to 6 per cent.; most oils are soluble in 65 per cent. alcohol 1 in 4, in no case should more than 2.5 volumes of 70 per cent. alcohol be required for solution. The chief constituents of the oil are: linalol, cineol, borneol, terpineol, geraniol, pinene, camphene and camphor. _Bay oil_, distilled from the leaves of Pimenta acris, and obtained from St. Thomas and other West Indian Islands. It is used to some extent as a perfume for shaving soaps, but chiefly in the Bay Rhum toilet preparation. Specific gravity at 15° C., 0.965-0.980; optical rotation, slightly lævo-rotatory up to -3°; phenols, estimated by absorption with 5 per cent. caustic potash solution, from 45 to 60 per cent.; the oil is generally insoluble in 90 per cent. alcohol, though when freshly distilled it dissolves in its own volume of alcohol of this strength. The oil contains eugenol, myrcene, chavicol, methyl eugenol, methyl chavicol, phellandrene, and citral. _Bergamot oil_, obtained by expression from the fresh peel of the fruit of Citrus Bergamia, and used very largely for the perfuming of toilet soaps. Specific gravity at 15° C., 0.880-0.886; optical rotation, +10° to +20°; esters, calculated as linalyl acetate, 35-40 per cent., and occasionally as high as 42-43 per cent.; frequently soluble in 1.5 parts of 80 per cent. alcohol, or failing that, should dissolve in one volume of 82.5 or 85 per cent. alcohol. When evaporated on the water-bath the oil should not leave more than 5-6 per cent. residue. Among the constituents of this oil are: linalyl acetate, limonene, dipentene, linalol, and bergaptene. _Bitter Almond Oil._--The volatile oil obtained from the fruit of _Amygdalus communis_. Specific gravity at 15° C., 1.045-1.06; optically inactive; refractive index at 20° C., 1.544-1.545; boiling point, 176-177° C.; soluble in 1 or 1.5 volumes of 70 per cent. alcohol. The oil consists almost entirely of benzaldehyde which may be estimated by absorption with a hot saturated solution of sodium bisulphite. The chief impurity is prussic acid, which is not always completely removed. This may be readily detected by adding to a small quantity of the oil two or three drops of caustic soda solution, and a few drops of ferrous sulphate solution containing ferric salt. After thoroughly shaking, acidulate with dilute hydrochloric acid, when a blue coloration will be produced if prussic acid is present. The natural oil may frequently be differentiated from artificial benzaldehyde by the presence of chlorine in the latter. As there is now on the market, however, artificial oil free from chlorine, it is no longer possible, by chemical means, to distinguish with certainty between the natural and the artificial product. To test for chlorine in a sample, a small coil of filter paper, loosely rolled, is saturated with the oil, and burnt in a small porcelain dish, covered with an inverted beaker, the inside of which is moistened with distilled water. When the paper is burnt, the beaker is rinsed with water, filtered, and the filtrate tested for chloride with silver nitrate solution. _Canada snake root oil_, from the root of Asarum canadense. Specific gravity at 15° C., 0.940-0.962; optical rotation, slightly lævo-rotatory up to -4°; refractive index at 20° C., 1.485-1.490; saponification number, 100-115; soluble in 3 or 4 volumes of 70 per cent. alcohol. The principal constituents of the oil are a terpene, asarol alcohol, another alcohol, and methyl eugenol. The oil is too expensive to be used in other than high-class toilet soaps. _Cananga_ or _Kananga oil_, the earlier distillate from the flowers of Cananga odorata, obtained chiefly from the Philippine Islands. Specific gravity at 15° C., 0.910-0.940; optical rotation, -17° to -30°; refractive index at 20° C., 1.4994-1.5024; esters, calculated as linalyl benzoate, 8-15 per cent.; soluble in 1.5 to 2 volumes of 95 per cent. alcohol, but becoming turbid on further addition. The oil is qualitatively similar in composition to Ylang-Ylang oil, and contains linalyl benzoate and acetate, esters of geraniol, cadinene, and methyl ester of p-cresol. _Caraway oil_, distilled from the seeds of Carum carui. Specific gravity at 15° C., 0.907-0.915; optical rotation, +77° to +79°; refractive index at 20° C., 1.485-1.486; soluble in 3 to 8 volumes of 80 per cent. alcohol. The oil should contain 50-60 per cent. of carvone, which is estimated by absorption with a saturated solution of neutral sodium sulphite. The remainder of the oil consists chiefly of limonene. _Cassia oil_, distilled from the leaves of Cinnamomum cassia, and shipped to this country from China in lead receptacles. Specific gravity at 15° C., 1.060-1.068; optical rotation, slightly dextro-rotatory up to +3° 30'; refractive index at 20° C., 1.6014-1.6048; soluble in 3 volumes of 70 per cent. alcohol as a general rule, but occasionally requires 1 to 2 volumes of 80 per cent. alcohol. The value of the oil depends upon its aldehyde content, the chief constituent being cinnamic aldehyde. This is determined by absorption with a hot saturated solution of sodium bisulphite. Three grades are usually offered, the best containing 80-85 per cent. aldehydes, the second quality, 75-80 per cent., and the lowest grade, 70-75 per cent. Other constituents of the oil are cinnamyl acetate and cinnamic acid. This oil gives the characteristic odour to Brown Windsor soap, and is useful for sweetening coal-tar medicated soaps. _Cedarwood oil_, distilled from the wood of Juniperus virginiana. Specific gravity at 15° C., 0.938-0.960; optical rotation, -35° to -45°; refractive index at 20° C., 1.5013-1.5030. The principal constituents are cedrene and cedrol. _Cinnamon oil_, distilled from the bark of Cinnamomum zeylanicum. Specific gravity at 15° C., 1.00-1.035; optical rotation, lævo-rotatory up to -2°; usually soluble in 2 to 3 volumes of 70 per cent. alcohol, but sometimes requires 1 volume of 80 per cent. alcohol for solution; aldehydes, by absorption with sodium bisulphite solution, 55-75 per cent.; and phenols, as measured by absorption with 5 per cent. potash, not exceeding 12 per cent. The value of this oil is not determined entirely by its aldehyde content as is the case with cassia oil, and any oil containing more than 75 per cent. aldehydes must be regarded with suspicion, being probably admixed with either cassia oil or artificial cinnamic aldehyde. The addition of cinnamon leaf oil which has a specific gravity at 15° C. of 1.044-1.065 is detected by causing a material rise in the proportion of phenols. Besides cinnamic aldehyde the oil contains eugenol and phellandrene. _Citronella Oil._--This oil is distilled from two distinct Andropogon grasses, the Lana Batu and the Maha pangiri, the former being the source of the bulk of Ceylon oil, and the latter being cultivated in the Straits Settlements and Java. The oils from these three localities show well-defined chemical differences. _Ceylon Citronella oil_ has the specific gravity at 15° C., 0.900-0.920; optical rotation, lævo-rotatory up to -12°; refractive index at 20° C., 1.480-1.484; soluble in 1 volume of 80 per cent. alcohol; total acetylisable constituents, calculated as geraniol, 54-70 per cent. _Singapore Citronella Oil._--Specific gravity at 15° C., 0.890-0.899; optical rotation, usually slightly lævo-rotatory up to -3°; refractive index at 20° C., 1.467-1.471; soluble in 1 to 1.5 volumes of 80 per cent. alcohol; total acetylisable constituents, calculated as geraniol, 80-90 per cent. _Java Citronella Oil._--Specific gravity at 15° C., 0.890-0.901; optical rotation, -1° to -6°; total acetylisable constituents, calculated as geraniol, 75-90 per cent.; soluble in 1-2 volumes of 80 per cent. alcohol. The chief constituents of the oil are geraniol, citronellal, linalol, borneol, methyl eugenol, camphene, limonene, and dipentene. It is very largely used for perfuming cheap soaps, and also serves as a source for the production of geraniol. _Bois de Rose Femelle oil_, or _Cayenne linaloe oil_, distilled from wood of trees of the Burseraceæ species. Specific gravity at 15° C., 0.874-0.880; optical rotation, -11° 30' to -16°; refractive index at 20° C., 1.4608-1.4630; soluble in 1.5 to 2 volumes of 70 per cent. alcohol. The oil consists almost entirely of linalol, with traces of saponifiable bodies, but appears to be free from methyl heptenone, found by Barbier and Bouveault in Mexican linaloe oil. This oil is distinctly finer in odour than the Mexican product. _Clove oil_, distilled from the unripe blossoms of Eugenia caryophyllata, the chief source of which is East Africa (Zanzibar and Pemba). Specific gravity at 15° C., 1.045-1.061; optical rotation, slightly lævo-rotatory up to -1° 30'; phenols, estimated by absorption with 5 per cent. potash solution, 86-92 per cent.; refractive index at 20° C., 1.5300-1.5360; soluble in 1 to 2 volumes of 70 per cent. alcohol. The principal constituent of the oil is eugenol, together with caryophyllene and acet-eugenol. While within certain limits the value of this oil is determined by its eugenol content, oils containing more than 93 per cent. phenols are usually less satisfactory in odour, the high proportion of phenols being obtained at the expense of the decomposition of some of the sesquiterpene. Oils with less than 88 per cent. phenols will be found somewhat weak in odour. This oil is extensively used in the cheaper toilet soaps and is an important constituent of carnation soaps. As already mentioned, however, it causes the soap to darken in colour somewhat rapidly, and must not therefore be used in any quantity, except in coloured soaps. _Concrete orris oil_, a waxy substance obtained by steam distillation of Florentine orris root. Melting point, 35-45° C., usually 40-45° C.; free acidity, calculated as myristic acid, 50-80 per cent.; ester, calculated as combined myristic acid, 4-10 per cent. The greater part of the product consists of the inodorous myristic acid, the chief odour-bearing constituent being irone. The high price of the oil renders its use only possible in the very best quality soaps. _Eucalyptus Oil._--Though there are some hundred or more different oils belonging to this class, only two are of much importance to the soap-maker. These are:-- (i.) Eucalyptus citriodora. Specific gravity at 15° C., 0.870-0.905; optical rotation, slightly dextro-rotatory up to +2°; soluble in 4-5 volumes of 70 per cent. alcohol. The oil consists almost entirely of citronellic aldehyde, and on absorption with saturated solution of sodium bisulphite should leave very little oil unabsorbed. (ii.) Eucalyptus globulus, the oil used in pharmacy, and containing 50-65 per cent. cineol. Specific gravity at 15° C., 0.910-0.930; optical rotation, +1° to +10°; soluble in 2 to 3 parts of 70 per cent. alcohol; cineol (estimated by combination with phosphoric acid, pressing, decomposing with hot water, and measuring the liberated cineol), not less than 50 per cent. Besides cineol, the oil contains d-pinene, and valeric, butyric, and caproic aldehydes. It is chiefly used in medicated soaps. _Fennel (sweet) oil_, obtained from the fruit of Foeniculum vulgare, grown in Germany, Roumania, and other parts of Europe. Specific gravity at 15° C., 0.965-0.985; optical rotation, +6° to +25°; refractive index at 20° C., 1.515-1.548; usually soluble in 2-6 parts 80 per cent. alcohol, but occasionally requires 1 part of 90 per cent. alcohol. The chief constituents of the oil are anethol, fenchone, d-pinene, and dipentene. _Geranium oils_, distilled from plants of the Pelargonium species. There are three principal kinds of this oil on the market--the African, obtained from Algeria and the neighbourhood, the Bourbon, distilled principally in the Island of Réunion, and the Spanish. The oil is also distilled from plants grown in the South of France, but this oil is not much used by soap-makers. A specially fine article is sold by a few essential oil firms under the name of "Geranium-sur-Rose," which as its name implies, is supposed to be geranium oil distilled over roses. This is particularly suitable for use in high-class soaps. The following are the general properties of these oils. It will be seen that the limits for the figures overlap to a considerable extent. _________________________________________________________________________ | | | | | | | | African. | Bourbon. | Spanish. | French. | |_________________________|___________|___________|___________|___________| | | | | | | | Specific gravity | | | | | | at 15° C. | .890-.900 | .888-.895 | .895-.898 | .897-.900 | | Optical rotation. |-6° to -10°|-9° to -18°|-8° to -11°|-8° to -11°| | Esters, calculated as | 20-27 | 27-32 | 20-27 | 18-23 | | geranyl tiglate | per cent. | per cent. | per cent. | per cent. | | Total alcohols, as | 68-75 | 70-80 | 65-75 | 66-75 | | geraniol. | per cent. | per cent. | per cent. | per cent. | | Solubility in 70 per | | | | | | cent. alcohol. | 1 in 1.5-2| 1 in 1.5-2| 1 in 2-3 | 1 in 1.5-2| |_________________________|___________|___________|___________|___________| The oil contains geraniol and citronellol, both free, and combined with tiglic, valeric, butyric, and acetic acids; also l-menthone. The African and Bourbon varieties are the two most commonly used for soap-perfurmery, the Spanish oil being too costly for extensive use. _Ginger-grass oil_, formerly regarded as an inferior kind of palma-rosa but now stated to be from an entirely different source. Specific gravity at 15° C., 0.889-0.897; optical rotation, +15°. The oil contains a large amount of geraniol, together with di-hydrocumin alcohol, d-phellandrene, d-limonene, dipentene, and l-carvone. _Guaiac wood oil_, distilled from the wood of Bulnesia sarmienti. Specific gravity at 30° C., 0.967-0.975; optical rotation, -4° 30' to -7°; refractive index at 20° C., 1.506-1.507; soluble in 3 to 5 volumes of 70 per cent. alcohol. The principal constituent of the oil is guaiac alcohol, or gusiol. This oil, which has what is generally termed a "tea-rose odour," is occasionally used as an adulterant for otto of rose. _Lavender oil_, distilled from the flowers of Lavandula vera, grown in England, France, Italy and Spain. The English oil is considerably the most expensive, and is seldom, if ever, used in soap. The French and Italian oils are the most common, the Spanish oil being a comparatively new article, of doubtful botanical origin, and more closely resembling aspic oil. English Oil.--Specific gravity at 15° C., 0.883-0.900; optical rotation, -4° to -10°; esters, calculated as linalyl acetate, 5-10 per cent.; soluble in 3 volumes of 70 per cent. alcohol. French and Italian Oils.--Specific gravity at 15° C., 0.885-0.900; optical rotation, -2° to -9°; refractive index at 20° C., 1.459-1.464; esters, calculated as linalyl acetate, 20-40 per cent., occasionally higher; soluble in 1.5-3 volumes of 70 per cent. alcohol. There was at one time a theory that the higher the proportion of ester the better the oil, but this theory has now to a very large extent become discredited, and there is no doubt that some of the finest oils contain less than 30 per cent. of esters. Spanish Oil.--Specific gravity at 15° C., 0.900-0.915; optical rotation, -2° to +7°; esters, calculated as linalyl acetate, 2-6 per cent.; soluble in 1-2 volumes of 70 per cent. alcohol. The chief constituents of lavender oil are linalyl acetate, linalol, geraniol, and linalyl butyrate, while the English oil also contains a distinct amount of cineol. _Lemon oil_, prepared by expressing the peel of the nearly ripe fruit of Citrus limonum, and obtained almost entirely from Sicily and Southern Italy. Specific gravity at 15° C., 0.856-0.860; optical rotation, +58° to +63°; refractive index at 20° C., 1.4730-1.4750; aldehydes (citral), 2.5 to 4 per cent. The principal constituents of the oil are limonene and citral, together with small quantities of pinene, phellandrene, octyl and nonyl aldehydes, citronellal, geraniol, geranyl acetate, and the stearopten, citraptene. _Lemon-grass_ (so-called _verbena_) oil, distilled from the grass Andropogon citratus, which is grown in India and, more recently, in the West Indies. The oils from these two sources differ somewhat in their properties, and also in value, the former being preferred on account of its greater solubility in alcohol. East Indian.--Specific gravity at 15° C., 0.898-0.906; optical rotation, -0° 30' to -6°; aldehydes, by absorption with bisulphite of soda solution, 65 to 78 per cent.; refractive index at 20° C., 1.485-1.487; soluble in 2-3 volumes of 70 per cent. alcohol. West Indian.--Specific gravity at 15° C., 0.886-0.893; optical rotation, faintly lævo-gyrate; refractive index at 20° C., 1.4855-1.4876; soluble in 0.5 volume of 90 per cent. alcohol. _Lime oil_, obtained by expression or distillation of the peel of the fruit of Citrus medica, and produced principally in the West Indies. Expressed Oil.--Specific gravity at 15° C., 0.870-0.885; optical rotation, +38° to +50°. Its most important constituent is citral. Distilled Oil.--This is entirely different in character to the expressed oil. Its specific gravity at 15° C. is 0.854-0.870; optical rotation, +38° to +54°; soluble in 5-8 volumes of 90 per cent. alcohol. _Linaloe oil_, distilled from the wood of trees of the Burseraceæ family, and obtained from Mexico. Specific gravity at 15° C., 0.876-0.892; optical rotation, usually lævo-rotatory, -3° to -13°, but occasionally dextro-rotatory up to +5° 30'; esters, calculated as linalyl acetate, 1-8 per cent.; total alcohols as linalol, determined by acetylation, 54-66 per cent.; soluble in 1-2 volumes of 70 per cent. alcohol. This oil consists mainly of linalol, together with small quantities of methyl heptenone, geraniol, and d-terpineol. _Marjoram oil_, distilled from Origanum majoranoides, and obtained entirely from Cyprus. Specific gravity at 15° C., 0.966; phenols, chiefly carvacrol, estimated by absorption with 5 per cent. caustic potash solution, 80-82 per cent.; soluble in 2-3 volumes of 70 per cent. alcohol. This oil is used in soap occasionally in place of red thyme oil. _Neroli Bigarade oil_, distilled from the fresh blossoms of the bitter orange, Citrus bigaradia. Specific gravity at 15° C., 0.875-0.882; optical rotation, +0° 40' to +10°, and occasionally much higher; refractive index at 20° C., 1.468-1.470; esters, calculated as linalyl acetate, 10-18 per cent.; soluble in 0.75-1.75 volumes of 80 per cent. alcohol, becoming turbid on further addition of alcohol. The chief constituents of the oil are limonene, linalol, linalyl acetate, geraniol, methyl anthranilate, indol, and neroli camphor. _Orange (sweet) oil_, expressed from the peel of Citrus aurantium. Specific gravity at 15° C., 0.849-0.852; optical rotation, +95° to +99°; refractive index at 20° C., 1.4726-1.4732. The oil contains some 90 per cent. limonene, together with nonyl alcohol, d-linalol, d-terpineol, citral, citronellal, decyl aldehyde, and methyl anthranilate. _Palmarosa_, or _East Indian geranium oil_, distilled from Andropogon Schoenanthus, a grass widely grown in India. Specific gravity at 15° C., 0.888-0.895; optical rotation, +1° to -3°; refractive index at 20° C., 1.472-1.476; esters, calculated as linalyl acetate, 7-14 per cent.; total alcohols, as geraniol, 75-93 per cent.; solubility in 70 per cent. alcohol, 1 in 3. The oil consists chiefly of geraniol, free, and combined with acetic and caproic acids, and dipentene. It is largely used in cheap toilet soaps, particularly in rose soaps. It is also a favourite adulterant for otto of rose, and is used as a source of geraniol. _Patchouli oil_, distilled from the leaves of Pogostemon patchouli, a herb grown in India and the Straits Settlements. Specific gravity at 15° C., 0.965-0.990; optical rotation, -45° to -63°; refractive index at 20° C., 1.504-1.511; saponification number, up to 12; sometimes soluble in 0.5 to 1 volume of 90 per cent. alcohol, becoming turbid on further addition. The solubility of the oil in alcohol increases with age. The oil consists to the extent of 97 per cent. of patchouliol and cadinene, which have little influence on its odour, and the bodies responsible for its persistent and characteristic odour have not yet been isolated. _Peppermint oil_, distilled from herbs of the Mentha family, the European and American from Mentha piperita, and the Japanese being generally supposed to be obtained from Mentha arvensis. The locality in which the herb is grown has a considerable influence on the resulting oil, as the following figures show:-- English.--Specific gravity at 15° C., 0.900-0.910; optical rotation, -22° to -33°; total menthol, 55-66 per cent.; free menthol, 50-60 per cent.; soluble in 3-5 volumes of 70 per cent. alcohol. American.--Specific gravity at 15° C., 0.906-0.920; optical rotation, -20° to -33°; total menthol, 50-60 per cent.; free menthol, 40-50 per cent. The Michigan oil is soluble in 3-5 volumes of 70 per cent. alcohol, but the better Wayne County oil usually requires 1-2 volumes of 80 per cent. alcohol, and occasionally 0.5 volume of 90 per cent. alcohol. French.--Specific gravity at 15° C., 0.917-0.925; optical rotation, -6° to -10°; total menthol, 45-55 per cent.; free menthol, 35-45 per cent.; soluble in 1 to 1.5 volumes of 80 per cent. Japanese.--Specific gravity at 25° C., 0.895-0.900; optical rotation, lævo-rotatory up to -43°; solidifies at 17 to 27° C.; total menthol, 70-90 per cent., of which 65-85 per cent. is free; soluble in 3-5 volumes of 70 per cent. alcohol. The dementholised oil is fluid at ordinary temperatures, has a specific gravity of 0.900-0.906 at 15° C., and contains 50-60 per cent. total menthol. Some twenty different constituents have been found in American peppermint oil, including menthol, menthone, menthyl acetate, cineol, amyl alcohol, pinene, l-limonene, phellandrene, dimethyl sulphide, menthyl isovalerianate, isovalerianic aldehyde, acetaldehyde, acetic acid, and isovalerianic acid. _Peru balsam oil_, the oily portion (so-called "cinnamein") obtained from Peru balsam. Specific gravity at 15° C., 1.100-1.107; optical rotation, slightly dextro-rotatory up to +2°; refractive index at 20° C., 1.569 to 1.576; ester, calculated as benzyl benzoate, 80-87 per cent.; soluble in 1 volume of 90 per cent. alcohol. The oil consists chiefly of benzyl benzoate and cinnamate, together with styracin, or cinnamyl cinnamate, and a small quantity of free benzoic and cinnamic acids. _Petitgrain oil_, obtained by distillation of the twigs and unripe fruit of Citrus bigaradia. There are two varieties of the oil, the French and the South American, the former being the more valuable. Specific gravity at 15° C., 0.886-0.900; optical rotation, -3° to +6°; refractive index at 20° C., 1.4604-1.4650; esters, calculated as linalyl acetate, 40-55 per cent., for the best qualities usually above 50 per cent.; soluble as a rule in 2-3 volumes of 70 per cent. alcohol, but occasionally requires 1-2 volumes of 80 per cent. alcohol. Among its constituents are limonene, linalyl acetate, geraniol and geranyl acetate. _Pimento oil_ (allspice), distilled from the fruit of Pimenta officinalis, which is found in the West Indies and Central America. Specific gravity at 15° C., 1.040-1.060; optical rotation, slightly lævo-rotatory up to -4°; refractive index at 20° C., 1.529-1.536; phenols, estimated by absorption with 5 per cent. potash solution, 68-86 per cent.; soluble in 1-2 volumes of 70 per cent. alcohol. The oil contains eugenol, methyl eugenol, cineol, phellandrene, and caryophyllene. _Rose oil (otto of rose)_, distilled from the flowers of Rosa damascena, though occasionally the white roses (Rosa alba) are employed. The principal rose-growing district is in Bulgaria, but a small quantity of rose oil is prepared from roses grown in Anatolia, Asia Minor. An opinion as to the purity of otto of rose can only be arrived at after a very full chemical analysis, supplemented by critical examination of its odour by an expert. The following figures, however, will be found to include most oils which can be regarded as genuine. Specific gravity at 30° C., 0.850-0.858; optical rotation at 30° C., -1° 30' to -3°; refractive index at 20° C., 1.4600-1.4645; saponification value, 7-11; solidifying point, 19-22° C.; iodine number, 187-194; stearopten content, 14-20 per cent.; melting point of stearopten, about 32° C. A large number of constituents have been isolated from otto of rose, many of which are, however, only present in very small quantities. The most important are geraniol, citronellol, phenyl ethyl alcohol, together with nerol, linalol, citral, nonylic aldehyde, eugenol, a sesquiterpene alcohol, and the paraffin stearopten. _Rosemary oil_, distilled from the herb Rosemarinus officinalis, and obtained from France, Dalmatia, and Spain. The herb is also grown in England, but the oil distilled therefrom is rarely met with in commerce. The properties of the oils vary with their source, and also with the parts of the plant distilled, distillation of the stalks as well as the leaves tending to reduce the specific gravity and borneol content, and increase the proportion of the lævo-rotatory constituent (lævo-pinene). The following figures may be taken as limits for pure oils:-- French and Dalmatian.--Specific gravity at 15° C., 0.900-0.916; optical rotation, usually dextro-rotatory, up to +15°, but may occasionally be lævo-rotatory, especially if stalks have been distilled with the leaves; ester, calculated as bornyl acetate, 1-6 per cent.; total borneol, 12-18 per cent.; usually soluble in 1-2 volumes of 82.5 per cent. alcohol. Spanish.--The properties of the Spanish oil are similar to the others, except that it is more frequently lævo-rotatory. Rosemary oil contains pinene, camphene, cineol, borneol, and camphor. _Sandalwood oil_, obtained by distillation of the wood of Santalum album (East Indian), Santalum cygnorum (West Australian), and Amyris balsamifera (West Indian). The oils obtained from these three different sources differ very considerably in value, the East Indian being by far the best. East Indian.--Specific gravity at 15° C., 0.975-0.980; optical rotation, -14° to -20°; refractive index at 20° C., 1.5045-1.5060; santalol, 92-97 per cent.; usually soluble in 4-6 volumes of 70 per cent. alcohol, though, an old oil occasionally is insoluble in 70 per cent. alcohol. West Australian.--Specific gravity at 15° C., 0.950-0.968; optical rotation, +5° to +7°; alcohols, calculated as santalol, 73-75 per cent.; insoluble in 70 per cent. alcohol, but readily dissolves in 1-2 volumes of 80 per cent. alcohol. West Indian.--Specific gravity at 15° C., 0.948-0.967; optical rotation, +13° 30' to +30°; insoluble in 70 per cent. alcohol. In addition to free santalol, the oil contains esters of santalol and santalal. _Sassafras oil_, distilled from the bark of Sassafras officinalis, and obtained chiefly from America. Specific gravity at 15° C., 1.06-1.08; optical rotation, +1° 50' to +4°; refractive index at 20° C., 1.524-1.532; soluble in, 6-10 volumes of 85 per cent. alcohol, frequently soluble in 10-15 volumes of 80 per cent. alcohol. The chief constituents are safrol, pinene, eugenol, camphor, and phellandrene. The removal of safrol, either intentionally or by accident, owing to cooling of the oil and consequent deposition of the safrol, is readily detected by the reduction of the specific gravity below 1.06. _Thyme oil, red and white_, distilled from the green or dried herb, Thymus vulgaris, both French and Spanish oils being met with. These oils are entirely different in character. French.--Specific gravity at 15° C., 0.91-0.933; slightly lævo-rotatory up to -4°, but usually too dark to observe; phenols, by absorption with 10 per cent. aqueous caustic potash, 25-55 per cent.; refractive index at 20° C., 1.490-1.500; soluble in 1-1.5 volumes of 80 per cent. alcohol. Spanish.--Specific gravity at 15° C., 0.955-0.966; optical rotation, slightly lævo-gyrate; phenols, 70-80 per cent.; refractive index at 20° C.; 1.5088-1.5122; soluble in 2-3 volumes of 70 per cent. alcohol. In addition to the phenols, thymol or carvacrol, these oils contain cymene, thymene and pinene. The white thyme oil is produced by rectifying the red oil, which is generally effected at the expense of a considerable reduction in phenol content, and hence in real odour value of the oil. _Verbena Oil._--The oil usually sold under this name is really lemon-grass oil (which see _supra_). The true verbena oil or French verveine is, however, occasionally met with. This is distilled in France from the verbena officinalis, and has the following properties: Specific gravity at 15° C., 0.891-0.898; optical rotation, slightly dextro- or lævo-rotatory; aldehydes, 70-75 per cent.; soluble in 2 volumes of 70 per cent. alcohol. The oil contains citral. _Vetivert oil_, distilled from the grass, Andropogon muricatus, or Cus Cus, and grown in the East Indies. Specific gravity at 15° C., 1.01-1.03; optical rotation, +20° to +26°; saponification number, 15-30; refractive index at 20° C., 1.521-1.524; soluble in 2 volumes of 80 per cent. alcohol. The price of this oil makes its use prohibitive except in the highest class soaps. _Wintergreen Oil._--There are two natural sources of this oil, the Gaultheria procumbens and the Betula lenta. Both oils consist almost entirely of methyl salicylate and are practically identical in properties, the chief difference being that the former has a slight lævo-rotation, while the latter is inactive. Specific gravity at 15° C., 1.180-1.187; optical rotation, Gaultheria oil, up to -1°, Betula oil, inactive; ester as methyl salicylate, at least 98 per cent.; refractive index at 20° C., 1.5354-1.5364; soluble in 2-6 volumes of 70 per cent. alcohol. Besides methyl salicylate, the oil contains triaconitane, an aldehyde or ketone, and an alcohol. _Ylang-ylang oil_, distilled from the flowers of Cananga odorata, the chief sources being the Philippine Islands and Java. Specific gravity at 15° C., 0.924-0.950; optical rotation, -30° to -60°, and occasionally higher; refractive index at 20° C., 1.496-1.512; ester, calculated as linalyl benzoate, 27-45 per cent., occasionally up to 50 per cent.; usually soluble in 1/2 volume of 90 per cent. alcohol. The composition of the oil is qualitatively the same as that of Cananga oil, but it is considerably more expensive and therefore can only be used in the highest grade soaps. _Artificial and Synthetic Perfumes._ During the past few years the constitution of essential oils has been studied by a considerable number of chemists, and the composition of many oils has been so fully determined that very good imitations can often be made at cheaper prices than those of the genuine oils, rendering it possible to produce cheap soaps having perfumes which were formerly only possible in the more expensive article. There is a considerable distinction, however, often lost sight of, between an _artificial_ and a _synthetic_ oil. An artificial oil may be produced by separating various constituents from certain natural oils, and so blending these, with or without the addition of other substances, as to produce a desired odour, the perfume being, at any rate in part, obtained from natural oils. A synthetic perfume, on the other hand, is entirely the product of the chemical laboratory, no natural oil or substance derived therefrom entering into its composition. The following are among the most important bodies of this class:-- _Amyl salicylate_, the ester prepared from amyl alcohol and salicylic acid, sometimes known as "Orchidée" or "Trèfle". This is much used for the production of a clover-scented soap. It has the specific gravity at 15° C., 1.052-1.054; optical rotation, +1° 16' to +1° 40'; refractive index at 20° C., 1.5056; and should contain not less than 97 per cent. ester, calculated as amyl salicylate. _Anisic aldehyde_, or _aubépine_, prepared by oxidation of anethol, and possessing a pleasant, hawthorn odour. This has the specific gravity at 15° C., 1.126; refractive index at 20° C., 1.5693; is optically inactive, and dissolves readily in one volume of 70 per cent. alcohol. _Benzyl Acetate_, the ester obtained from benzyl alcohol and acetic acid. This has a very strong and somewhat coarse, penetrating odour, distinctly resembling jasmine. Its specific gravity at 15° C. is 1.062-1.065; refractive index at 20° C., 1.5020; and it should contain at least 97-98 per cent. ester, calculated as benzyl acetate. _Citral_, the aldehyde occurring largely in lemon-grass and verbena oils, also to a less extent in lemon and orange oils, and possessing an intense lemon-like odour. It has a specific gravity at 15° C., 0.896-0.897, is optically inactive, and should be entirely absorbed by a hot saturated solution of sodium bisulphite. _Citronellal_, an aldehyde possessing the characteristic odour of citronella oil, in which it occurs to the extent of about 20 per cent., and constituting considerably over 90 per cent. of eucalyptus citriodora oil. Its specific gravity at 15° C. is 0.862; refractive index at 20° C., 1.447; optical rotation, +8° to +12°; and it should be entirely absorbed by a hot saturated solution of sodium bisulphite. _Coumarin_, a white crystalline product found in Tonka beans, and prepared synthetically from salicylic acid. It has an odour resembling new-mown hay, and melts at 67° C. _Geraniol_, a cyclic alcohol, occurring largely in geranium, palma-rosa, and citronella oils. Its specific gravity at 15° C. is 0.883-0.885; refractive index at 20° C., 1.4762-1.4770; it is optically inactive, and boils at 218°-225° C. _Heliotropin_, which possesses the characteristic odour of heliotrope, is prepared artificially from safrol. It crystallises in small prisms melting at 86° C. _Hyacinth._--Most of the articles sold under this name are secret blends of the different makers. Styrolene has an odour very much resembling hyacinth, and probably forms the basis of most of these preparations, together with terpineol, and other artificial bodies. The properties of the oil vary considerably for different makes. _Ionone_, a ketone first prepared by Tiemann, and having when diluted a pronounced violet odour. It is prepared by treating a mixture of citral and acetone with barium hydrate, and distilling in vacuo. Two isomeric ketones, [alpha]-ionone and [beta]-ionone, are produced, the article of commerce being usually a mixture of both. The two ketones have the following properties:-- Alpha-ionone.--Specific gravity at 15° C., 0.9338; refractive index at 16.5 C., 1.50048 (Chuit); optically it is inactive. Beta-ionone.--Specific gravity at 15° C., 0.9488; refractive index at 16.8° C., 1.52070 (Chuit); optically it is inactive also. The product is usually sold in 10 or 20 per cent. alcoholic solution ready for use. _Jasmine._--This is one of the few cases in which the artificial oil is probably superior to that obtained from the natural flowers, possibly due to the extreme delicacy of the odour, and its consequent slight decomposition during preparation from the flowers. The chemical composition of the floral perfume has been very exhaustively studied, and the artificial article now on the market may be described as a triumph of synthetical chemistry. Among its constituents are benzyl acetate, linalyl acetate, benzyl alcohol, indol, methyl anthranilate, and a ketone jasmone. _Linalol_, the alcohol forming the greater part of linaloe and bois de rose oils, and found also in lavender, neroli, petitgrain, bergamot, and many other oils. The article has the specific gravity at 15° C., 0.870-0.876; optical rotation, -12° to -14°; refractive index at 20° C., 1.463-1.464; and when estimated by acetylation, yields about 70 per cent. of alcohols. _Linalyl acetate_, or _artificial bergamot oil_, is the ester formed when linalol is treated with acetic anhydride. It possesses a bergamot-like odour, but it is doubtful whether its value is commensurate with its greatly increased price over that of ordinary bergamot oil. It has the specific gravity at 15° C., 0.912. _Musk (Artificial)._--Several forms of this are to be obtained, practically all of which are nitro-derivatives of aromatic hydrocarbons. The original patent of Baur, obtained in 1889, covered the tri-nitro-derivative of tertiary butyl xylene. The melting point of the pure article usually lies between 108° and 112° C., and the solubility in 95 per cent. alcohol ranges from 1 in 120 to 1 in 200, though more soluble forms are also made. An important adulterant, which should always be tested for, is acetanilide (antifebrin), which may be detected by the characteristic isocyanide odour produced when musk containing this substance is boiled with alcoholic potash, and a few drops of chloroform added. Acetanilide also increases the solubility in 95 per cent. alcohol. _Neroli Oil (Artificial)._--Like jasmine oil, the chemistry of neroli oil is now very fully known, and it is therefore possible to prepare an artificial product which is a very good approximation to the natural oil, and many such are now on the market, which, on account of their comparative cheapness, commend themselves to the soap-perfumer. These consist chiefly of linalol, geraniol, linalyl acetate, methyl anthranilate, and citral. _Mirbane Oil_ or _Nitrobenzene._--This is a cheap substitute for oil of bitter almonds, or benzaldehyde, and is a very coarse, irritating perfume, only suitable for use in the very cheapest soaps. It is prepared by the action of a mixture of nitric and sulphuric acids on benzene at a temperature not exceeding 40° C. Its specific gravity is 1.205-1.206; refractive index at 20° C., 1.550; and boiling point, 206° C. _Niobe oil_, or _ethyl benzoate_, the ester obtained from ethyl alcohol and benzoic acid, and having the specific gravity at 15° C., 1.094-1.095; refractive index at 20° C., 1.5167; boiling point, 196.5°-198° C.; soluble in 1.5 volumes of 70 per cent. alcohol. _Oeillet_ is a combination possessed of a sweet carnation-like odour and having as a basis, eugenol or isoeugenol. Its properties vary with the source of supply. _Rose Oil (Artificial)._--Several good and fairly cheap artificial rose oils are now obtainable, consisting chiefly of citronellol, geraniol, linalol, phenyl ethyl alcohol, and citral. In some cases stearopten or other wax is added, to render the oil more similar in appearance to the natural article, but as these are inodorous, no advantage is gained in this way, and there is, further, the inconvenience in cold weather of having to first melt the oil before use. _Safrol_, an ether which is the chief constituent of sassafras oil, and also found in considerable quantity in camphor oil. It is sold as an artificial sassafras oil, and is very much used in perfuming cheap toilet or household soaps. Its specific gravity at 15° C. is 1.103-1.106; refractive index at 20° C., 1.5373; and it dissolves in fifteen volumes of 80 per cent. alcohol. _Santalol_, the alcohol or mixture of alcohols obtained from sandalwood oil. Its specific gravity at 15° C. is 0.9795; optical rotation, -18°; and refractive index at 20° C., 1.507. _Terebene_, a mixture of dipentene and other hydrocarbons prepared from turpentine oil by treatment with concentrated sulphuric acid, is used chiefly in medicated soaps. Its specific gravity at 15° C. is 0.862-0.868; the oil is frequently slightly dextro- or lævo-rotatory; the refractive index at 20° C., 1.470-1.478. _Terpineol_, an alcohol also prepared from turpentine oil by the action of sulphuric acid, terpene hydrate being formed as an intermediate substance. It has a distinctly characteristic lilac odour, and on account of its cheapness is much used in soap perfumery, especially for a lilac or lily soap. Its specific gravity at 15° C. is 0.936-0.940; refractive index at 20° C., 1.4812-1.4835; and boiling point about 210°-212° C. It is optically inactive, and readily soluble in 1.5 volumes of 70 per cent. alcohol. _Vanillin_, a white crystalline solid, melting at 80°-82° C. and prepared by the oxidation of isoeugenol. It has a strong characteristic odour, and occurs, associated with traces of benzoic acid and heliotropin, in the vanilla bean. It can only be used in small quantity in light-coloured soaps, as it quickly tends to darken the colour of the soap. CHAPTER IX. GLYCERINE MANUFACTURE AND PURIFICATION. _Treatment of Lyes--Evaporation to Crude Glycerine--Distillation--Distilled and Dynamite Glycerine--Chemically Pure Glycerine--Animal Charcoal for Decolorisation--Glycerine obtained by other Methods of Saponification--Yield of Glycerine from Fats and Oils._ As pointed out in Chapter II. the fatty acids, which, combined with soda or potash, form soap, occur in nature almost invariably in the form of glycerides, _i.e._, compounds of fatty acids with glycerol, and as the result of saponification of a fat or oil glycerine is set free. In Chapter V. processes of soap-making are described in which (1) the glycerine is retained in the finished soap, and (2) the glycerine is contained in the lyes, in very dilute solution, contaminated with salt and other impurities. These lyes, though now constituting the chief source of profit in the manufacture of cheap soaps, were till early in last century simply run down the drains as waste liquor. Much attention has been devoted to the purification and concentration of glycerine lyes; and elaborate plant of various forms has been devised for the purpose. _Treatment of Lyes._--The spent lyes withdrawn from the soap-pans are cooled, and the soap, which has separated during the cooling, is carefully removed and returned to the soap-house for utilisation in the manufacture of brown soap. Spent lyes may vary in their content of glycerol from 3 to 8 per cent., and this depends not only upon the system adopted in the working of the soap-pans, but also upon the materials used. Although, in these days of pure caustic soda, spent lyes are more free from impurities than formerly, the presence of sulphides and sulphites should be carefully avoided, if it is desired to produce good glycerine. The lyes are transferred to a lead-lined tank of convenient size, and treated with commercial hydrochloric acid and aluminium sulphate, sufficient being added of the former to neutralise the free alkali, and render the liquor faintly acid, and of the latter to completely precipitate the fatty acids. The acid should be run in slowly, and the point when enough has been added, is indicated by blue litmus paper being slightly reddened by the lyes. The whole is then agitated with air, when a sample taken from the tank and filtered should give a clear filtrate. Having obtained this clear solution, agitation is stopped, and the contents of the tank passed through a filter press. The scum, which accumulates on the treatment tank, may be transferred to a perforated box suspended over the tank, and the liquor allowed to drain from it. The filtered liquor is now rendered slightly alkaline by the addition of caustic soda or carbonate, and, after filtering, is ready for evaporation. The acid and alum salt used in the above treatment must be carefully examined for the presence of arsenic, and any deliveries of either article, which contain that impurity, rejected. Lime, bog ore, and various metallic salts, such as ferric chloride, barium chloride, and copper sulphate have been suggested, and in some instances are used instead of aluminium sulphate, but the latter is generally employed. _Evaporation to Crude Glycerine._--The clear treated lyes, being now free from fatty, resinous, and albuminous matter, and consisting practically of an aqueous solution of common salt (sodium chloride) and glycerine, is converted into crude glycerine by concentration, which eliminates the water and causes most of the salt to be deposited. This concentration was originally performed in open pans heated by fire or waste combustible gases. In the bottom of each pan was placed a dish in which the salt deposited, and this dish was lifted out periodically by the aid of an overhead crane and the contents emptied and washed. Concentration was continued until the temperature of the liquor was 300° F. (149° C.), when it was allowed to rest before storing. This liquor on analysis gave 80 per cent. glycerol and from 9 to 10-1/2 per cent. salts (ash); hence the present standard for crude glycerine. Concentration in open pans has now been superseded by evaporation _in vacuo_. The subject of the gradual development of the modern efficient evaporating plant from the vacuum pan, originated and successfully applied by Howard in 1813 in the sugar industry, is too lengthy to detail here, suffice it to say that the multiple effects now in vogue possess distinct advantages--the greatest of these being increased efficiency combined with economy. The present type of evaporator consists of one or more vessels, each fitted with a steam chamber through which are fixed vertical hollow tubes. The steam chamber of the first vessel is heated with direct steam, or with exhaust steam (supplied from the exhaust steam receiver into which passes the waste steam of the factory); the treated lyes circulating through the heated tubes is made to boil at a lower temperature, with the reduced pressure, than is possible by heating in open pans. The vapour given off by the boiling liquor is conveyed through large pipes into the steam chamber of the second vessel, where its latent heat is utilised in producing evaporation, the pressure being further reduced, as this second vessel is under a greater vacuum than No. 1. Thus we get a "double effect," as the plant consisting of two pans is termed. The vapours discharged from the second vessel during boiling are passed through pipes to the steam chamber of the third vessel (in a "triple effect"), and there being condensed, create a partial vacuum in the second vessel. The third vessel may also be heated by means of live steam. The vapours arising from the last vessel of the evaporating plant, or in the case of a "single effect" from the vessel, are conveyed into a condenser and condensed by injection water, which is drawn off by means of the pump employed for maintaining a vacuum of 28 inches in the vessel. In the most recent designs of large evaporative installations, the vapours generated from the last vessel are drawn through a device consisting of a number of tubes enclosed in a casing, and the latent heat raises the temperature of the treated lyes proceeding through the tubes to supply the evaporator. It will thus be observed that the object of multiple effects is to utilise all the available heat in performing the greatest possible amount of work. Special devices are attached to the plant for automatically removing the condensed water from the steam chambers without the loss of useful heat, and as a precaution against splashing over and subsequent loss of glycerine through conveyance to the steam chamber, dash plates and "catch-alls" or "save-alls" of various designs are fitted on each vessel. In working the plant, the liquor in each vessel is kept at a fairly constant level by judicious feeding from one to the other; the first vessel is, of course, charged with treated lyes. As the liquor acquires a density of 42° Tw. (25° B.) salt begins to deposit, and may be withdrawn into one of the many patented appliances, in which it is freed from glycerine, washed and dried ready for use at the soap pans. Difficulty is sometimes experienced with the tubes becoming choked with salt, thereby diminishing and retarding evaporation. It may be necessary to dissolve the encrusted salt with lyes or water, but with careful working the difficulty can be obviated by washing out with weak lyes after each batch of crude glycerine has been run away, or by increasing the circulation. It is claimed that by the use of the revolving heater designed by Lewkowitsch, the salting up of tubes is prevented. The salt having been precipitated and removed, evaporation is continued until a sample taken from the last vessel has a density of 60° Tw. (33.3 B.) at 60° F. (15.5° C.). When this point is reached, the crude glycerine is ready to be withdrawn into a tank, and, after allowing the excess of salt to deposit, may be transferred to the storage tank. The colour of crude glycerine varies from light brown to dark brown, almost black, and depends largely on the materials used for soap-making. The organic matter present in good crude glycerine is small in amount, often less than 1 per cent.; arsenic, sulphides and sulphites should be absent. Crude glycerine is refined in some cases by the producers themselves; others sell it to firms engaged more particularly in the refined glycerine trade. _Distillation._--Crude glycerine is distilled under vacuum with the aid of superheated steam. The still is heated directly with a coal or coke fire, and in this fire space is the superheater, which consists of a coil of pipes through which high pressure steam from the boiler is superheated. The distillation is conducted at a temperature of 356°F. (180° C.). To prevent the deposition and burning of salt on the still-bottom during the distillation, a false bottom is supported about 1 foot from the base of the still. With the same object in view, it has been suggested to rotate the contents with an agitator fixed in the still. Every care is taken that the still does not become overheated; this precaution not only prevents loss of glycerine through carbonisation, but also obviates the production of tarry and other bodies which might affect the colour, taste, and odour of the distilled glycerine. The vacuum to be used will, of course, depend upon the heat of the fire and still, but as a general rule good results are obtained with an 18 inch vacuum. There are quite a large number of designs for still heads, and "catch-alls," having for their object the prevention of loss of glycerine. The distillate passes into a row of condensers, to each of which is attached a receptacle or receiver. It is needless to state that the condensing capacity should be in excess of theoretical requirements. The fractions are of varying strengths and quality; that portion, with a density less than 14° Tw. (19.4° B.), is returned to the treated-lyes tank. The other portion of the distillate is concentrated by means of a dry steam coil in a suitable vessel under a 28 inch vacuum. When sufficiently concentrated the glycerine may be decolorised, if necessary, by treating with 1 per cent. animal charcoal and passing through a filter press, from which it issues as "dynamite glycerine". The residue in the still, consisting of 50-60 per cent. glycerine and varying proportions of various sodium salts--_e.g._ acetate, chloride, sulphate, and combinations with non-volatile organic acids--is generally boiled with water and treated with acid. The tar, which is separated, floats on the surface as the liquor is cooling, and may be removed by ladles, or the whole mixed with waste charcoal, and filtered. The filtrate is then evaporated, when the volatile organic acids are driven off; the concentrated liquor is finally mixed with crude glycerine which is ready for distillation, or it may be distilled separately. _Distilled Glycerine._--This class of commercial glycerine, although of limited use in various other branches of industry, finds its chief outlet in the manufacture of explosives. Specifications are usually given in contracts drawn up between buyers and sellers, to which the product must conform. The chief stipulation for dynamite glycerine is its behaviour in the nitration test. When glycerine is gradually added to a cold mixture of strong nitric and sulphuric acids, it is converted into nitro-glycerine, which separates as an oily layer on the surface of the acid. The more definite and rapid the separation, the more suitable is the glycerine for dynamite-making. Dynamite glycerine should be free from arsenic, lime, chlorides, and fatty acids, the inorganic matter should not amount to more than 0.1 per cent., and a portion diluted and treated with nitrate of silver solution should give no turbidity or discoloration in ten minutes. The specific gravity should be 1.262 at 15° C. (59° F.) and the colour somewhat yellow. _Chemically pure glycerine_ or double distilled glycerine is produced by redistilling "once distilled" glycerine. Every care is taken to avoid all fractions which do not withstand the nitrate of silver test. The distillation is very carefully performed under strict supervision. The distillate is concentrated and after treatment with animal charcoal and filtration should conform to the requirements of the British Pharmacopoeia. These are specified as follows: Specific gravity at 15.5° C., 1.260. It should yield no characteristic reaction with the tests for lead, copper, arsenium, iron, calcium, potassium, sodium, ammonium, chlorides, or sulphates. It should contain no sugars and leave no residue on burning. _Animal Charcoal for Decolorisation._--The application of animal charcoal for decolorising purposes dates back a century, and various are the views that have been propounded to explain its action. Some observers base it upon the physical condition of the so-called carbon present, and no doubt this is an important factor, coupled with the porosity. Others consider that the nitrogen, which is present in all animal charcoal and extremely difficult to remove, is essential to the action. Animal charcoal should be freed from gypsum (sulphate of lime), lest in the burning, sulphur compounds be formed which would pass into the glycerine and contaminate it. The "char" should be well boiled with water, then carbonate of soda or caustic soda added in sufficient quantity to give an alkaline reaction, and again well boiled. The liquor is withdrawn and the charcoal washed until the washings are no longer alkaline. The charcoal is then separated from the liquor and treated with hydrochloric acid; opinions differ as to the amount of acid to be used. Some contend that phosphate of lime plays such an important part in decolorising that it should not be removed, but it has, however, been demonstrated that this substance after exposure to heat has very little decolorising power. Animal charcoal boiled with four times its weight of a mixture consisting of equal parts of commercial hydrochloric acid (free from arsenic) and water for twelve hours, then washed free from acid, dried, and burned in closed vessels gives a product possessed of great decolorising power for use with glycerines. A good animal charcoal will have a dull appearance, and be of a deep colour; it should be used in fine grains and not in the form of a powder. The charcoal from the filter presses is washed free from glycerine (which is returned to the treated lyes), cleansed from foreign substances by the above treatment and revivified by carefully heating in closed vessels for twelve hours. _Glycerine obtained by other Methods of Saponification._--French saponification or "candle crude" glycerine is the result of concentration of "sweet water" produced in the manufacture of stearine and by the autoclave process. It contains 85-90 per cent. glycerol, possesses a specific gravity of 1.240-1.242, and may be readily distinguished from the soap-crude glycerine by the absence of salt (sodium chloride). This glycerine is easily refined by treatment with charcoal. The glycerine water resulting from acid saponification methods requires to be rendered alkaline by the addition of lime--the sludge is separated, and the liquor evaporated to crude. The concentration may be performed in two stages--first to a density of 32° Tw. (20° B.), when the calcium sulphate is allowed to deposit, and the separated liquor concentrated to 48° Tw. (28° B.) glycerine, testing 85 per cent. glycerol and upwards. _Yield of Glycerine from Fats and Oils._--The following represent practicable results which should be obtained from the various materials:-- Tallow 9 per cent. of 80 per cent. Glycerol. Cotton-seed oil 10 " Cocoa-nut oil 12 " Palm-kernel oil 18 " Olive oil 10 " Palm oil 6 " Greases (Bone fats) 6-8 " The materials vary in glycerol content with the methods of preparation; especially is this the case with tallows and greases. Every care should be taken that the raw materials are fresh and they should be carefully examined to ascertain if any decomposition has taken place in the glycerides--this would be denoted by the presence of an excess of free acidity, and the amount of glycerol obtainable from such a fat would be correspondingly reduced. CHAPTER X. ANALYSIS OF RAW MATERIALS, SOAP, AND GLYCERINE. _Fats and Oils--Alkalies and Alkali Salts--Essential Oils--Soap--Lyes--Crude Glycerine._ _Raw Materials._--Average figures have already been given in Chapters III. and VIII. for the more important physical and chemical characteristics of fats and oils, also of essential oils; the following is an outline of the processes usually adopted in their determination. For fuller details, text-books dealing exhaustively with the respective subjects should be consulted. FATS AND OILS. It is very undesirable that any of these materials should be allowed to enter the soap pan without an analysis having first been made, as the oil may not only have become partially hydrolysed, involving a loss of glycerine, or contain albuminous matter rendering the soap liable to develop rancidity, but actual sophistication may have taken place. Thus a sample of tallow recently examined by the authors contained as much as 40 per cent. of an unsaponifiable wax, which would have led to disaster in the soap pan, had the bulk been used without examination. After observing the appearance, colour, and odour of the sample, noting any characteristic feature, the following physical and chemical data should be determined. _Specific Gravity at 15° C._ This may be taken by means of a Westphal balance, or by using a picnometer of either the ordinary gravity bottle shape, with perforated stopper, or the Sprengel U-tube. The picnometer should be calibrated with distilled water at 15° C. The specific gravity of solid fats may be taken at an elevated temperature, preferably that of a boiling water bath. _Free acidity_ is estimated by weighing out from 2 to 5 grammes of the fat or oil, dissolving in neutral alcohol (purified methylated spirit) with gentle heat, and titrating with a standard aqueous or alcoholic solution of caustic soda or potash, using phenol-phthalein as indicator. The contents of the flask are well shaken after each addition of alkali, and the reaction is complete when the slight excess of alkali causes a permanent pink coloration with the indicator. The standard alkali may be N/2, N/5, or N/10. It is usual to calculate the result in terms of oleic acid (1 c.c. N/10 alkali = 0.0282 gramme oleic acid), and express in percentage on the fat or oil. _Example._--1.8976 grammes were taken, and required 5.2 c.c. of N/10 KOH solution for neutralisation. 5.2 × 0.0282 × 100 ------------------ = 7.72 per cent. free fatty acids, 1.8976 expressed as oleic acid. The free acidity is sometimes expressed as _acid value_, which is the amount of KOH in milligrammes necessary to neutralise the free acid in 1 gramme of fat or oil. In the above example:-- 5.2 × 5.61 ---------- = 15.3 acid value. 1.8976 The _saponification equivalent_ is determined by weighing 2-4 grammes of fat or oil into a wide-necked flask (about 250 c.c. capacity), adding 30 c.c. neutral alcohol, and warming under a reflux condenser on a steam or water-bath. When boiling, the flask is disconnected, 50 c.c. of an approximately semi-normal alcoholic potash solution carefully added from a burette, together with a few drops of phenol-phthalein solution, and the boiling under a reflux condenser continued, with frequent agitation, until saponification is complete (usually from 30-60 minutes) which is indicated by the absence of fatty globules. The excess of alkali is titrated with N/1 hydrochloric or sulphuric acid. The value of the approximately N/2 alkali solution is ascertained by taking 50 c.c. together with 30 c.c. neutral alcohol in a similar flask, boiling for the same length of time as the fat, and titrating with N/1 hydrochloric or sulphuric acid. The "saponification equivalent" is the amount of fat or oil in grammes saponified by 1 equivalent or 56.1 grammes of caustic potash. _Example._--1.8976 grammes fat required 18.95 c.c. N/1 acid to neutralise the unabsorbed alkali. Fifty c.c. approximately N/2 alcoholic potash solution required 25.6 c.c. N/ acid.. 25.6 - 18.95 = 6.65 c.c. N/1 KOH required by fat. 1.8976 × 1000 / 6.65 = 285.3 Saponification Equivalent. The result of this test is often expressed as the "Saponification Value," which is the number of milligrammes of KOH required for the saponification of 1 gramme of fat. This may be found by dividing 56,100 by the saponification equivalent or by multiplying the number of c.c. of N/1 alkali absorbed, by 56.1 and dividing by the quantity of fat taken. Thus, in the above example:-- 6.65 × 56.1 / 1.8976 = 196.6 Saponification Value. The _ester_ or _ether value_, or number of milligrammes of KOH required for the saponification of the neutral esters or glycerides in 1 gramme of fat, is represented by the difference between the saponification and acid values. In the example given, the ester value would be 196.6 - 15.3 = 181.3. _Unsaponifiable Matter._--The usual method adopted is to saponify about 5 grammes of the fat or oil with 50 c.c. of approximately N/2 alcoholic potash solution by boiling under a reflux condenser with frequent agitation for about 1 hour. The solution is then evaporated to dryness in a porcelain basin over a steam or water-bath, and the resultant soap dissolved in about 200 c.c. hot water. When sufficiently cool, the soap solution is transferred to a separating funnel, 50 c.c. of ether added, the whole well shaken, and allowed to rest. The ethereal layer is removed to another separator, more ether being added to the aqueous soap solution, and again separated. The two ethereal extracts are then washed with water to deprive them of any soap, separated, transferred to a flask, and the ether distilled off upon a water-bath. The residue, dried in the oven at 100° C. until constant, is the "unsaponifiable matter," which is calculated to per cent. on the oil. In this method, it is very frequently most difficult to obtain a distinct separation of ether and aqueous soap solution--an intermediate layer of emulsion remaining even after prolonged standing, and various expedients have been recommended to overcome this, such as addition of alcohol (when petroleum ether is used), glycerine, more ether, water, or caustic potash solution, or by rotatory agitation. A better plan is to proceed as in the method above described as far as dissolving the resulting soap in 200 c.c. water, and then boil for twenty or thirty minutes. Slightly cool and acidify with dilute sulphuric acid (1 to 3), boil until the fatty acids are clear, wash with hot water free from mineral acid, and dry by filtering through a hot water funnel. Two grammes of the fatty acids are now dissolved in neutral alcohol saturated with some solvent, preferably a light fraction of benzoline, a quantity of the solvent added to take up the unsaponifiable matter, and the whole boiled under a reflux condenser. After cooling, the liquid is titrated with N/2 aqueous KOH solution, using phenol-phthalein as indicator, this figure giving the amount of the total fatty acids present. The whole is then poured into a separating funnel, when separation immediately takes place. The alcoholic layer is withdrawn, the benzoline washed with warm water (about 32° C.) followed by neutral alcohol (previously saturated with the solvent), and transferred to a tared flask, which is attached to a condenser, and the benzoline distilled off. The last traces of solvent remaining in the flask are removed by gently warming in the water-oven, and the flask cooled and weighed, thus giving the amount of unsaponifiable matter. _Constitution of the Unsaponifiable Matter._--Unsaponifiable matter may consist of cholesterol, phytosterol, solid alcohols (cetyl and ceryl alcohols), or hydrocarbons (mineral oil). Cholesterol is frequently found in animal fats, and phytosterol is a very similar substance present in vegetable fats. Solid alcohols occur naturally in sperm oil, but hydrocarbons, which may be generally recognised by the fluorescence or bloom they give to the oil, are not natural constituents of animal or vegetable oils and fats. The presence of cholesterol and phytosterol may be detected by dissolving a small portion of the unsaponifiable matter in acetic anhydride, and adding a drop of the solution to one drop of 50 per cent. sulphuric acid on a spot plate, when a characteristic blood red to violet coloration is produced. It has been proposed to differentiate between cholesterol and phytosterol by their melting points, but it is more reliable to compare the crystalline forms, the former crystallising in laminæ, while the latter forms groups of needle-shaped tufts. Another method is to convert the substance into acetate, and take its melting point, cholesterol acetate melting at 114.3-114.8° C., and phytosterol acetate at 125.6°-137° C. Additional tests for cholesterol have been recently proposed by Lifschütz (_Ber. Deut. Chem. Ges._, 1908, 252-255), and Golodetz (_Chem. Zeit._, 1908, 160). In that due to the former, which depends on the oxidation of cholesterol to oxycholesterol ester and oxycholesterol, a few milligrammes of the substance are dissolved in 2-3 c.c. glacial acetic acid, a little benzoyl peroxide added, and the solution boiled, after which four drops of strong sulphuric acid are added, when a violet-blue or green colour is produced, if cholesterol is present, the violet colour being due to oxycholesterol ester, the green to oxycholesterol. Two tests are suggested by Golodetz (1) the addition of one or two drops of a reagent consisting of five parts of concentrated sulphuric acid and three parts of formaldehyde solution, which colours cholesterol a blackish-brown, and (2) the addition of one drop of 30 per cent. formaldehyde solution to a solution of the substance in trichloracetic acid, when with cholesterol an intense blue coloration is produced. _Water._--From 5 to 20 grammes of the fat or oil are weighed into a tared porcelain or platinum dish, and stirred with a thermometer, whilst being heated over a gas flame at 100° C. until bubbling or cracking has ceased, and reweighed, the loss in weight representing the water. In cases of spurting a little added alcohol will carry the water off quietly. To prevent loss by spurting, Davis (_J. Amer. Chem. Soc._, 23, 487) has suggested that the fat or oil should be added to a previously dried and tared coil of filter paper contained in a stoppered weighing bottle, which is then placed in the oven and dried at 100° C. until constant in weight. Of course, this method is not applicable to oils or fats liable to oxidation on heating. _Dregs, Dirt, Adipose Tissue, Fibre, etc._--From 10 to 15 grammes of the fat are dissolved in petroleum ether with frequent stirring, and passed through a tared filter paper. The residue retained by the filter paper is washed with petroleum ether until free from fat, dried in the water-oven at 100° C. and weighed. If the amount of residue is large, it may be ignited, and the proportion and nature of the ash determined. The amount of impurities may also be estimated by Tate's method, which is performed by weighing 5 grammes of fat into a separating funnel, dissolving in ether, and allowing the whole to stand to enable the water to deposit. After six hours' rest the water is withdrawn, the tube of the separator carefully dried, and the ethereal solution filtered through a dried tared filter paper into a tared flask. Well wash the filter with ether, and carefully dry at 100° C. The ether in the flask is recovered, and the flask dried until all ether is expelled, and its weight is constant. The amount of fat in the flask gives the quantity of actual fat in the sample taken; the loss represents the water and other impurities, and these latter may be obtained from the increase of weight of the filter paper. _Starch_ may be detected by the blue coloration it gives with iodine solution, and confirmed by microscopical examination, or it may be converted into glucose by inversion, and the glucose estimated by means of Fehling's solution. _Iodine Absorption._--This determination shows the amount of iodine absorbed by a fat or oil, and was devised by Hübl, the reagents required being as follows:-- (1) Solution of 25 grammes iodine in 500 c.c. absolute alcohol; (2) solution of 30 grammes mercuric chloride in 500 c.c. absolute alcohol, these two solutions being mixed together and allowed to stand at least twelve hours before use; (3) a freshly prepared 10 per cent. aqueous solution of potassium iodide; and (4) a N/10 solution of sodium thiosulphate, standardised just prior to use by titrating a weighed quantity of resublimed iodine dissolved in potassium iodide solution. In the actual determination, 0.2 to 0.5 gramme of fat or fatty acids is carefully weighed into a well-fitting stoppered 250 c.c. bottle, dissolved in 10 c.c. chloroform, and 25 c.c. of the Hübl reagent added, the stopper being then moistened with potassium iodide solution and placed firmly in the bottle, which is allowed to stand at rest in a dark place for four hours. A blank experiment is also performed, using the same quantities of chloroform and Hübl reagent, and allowing to stand for the same length of time. After the expiration of four hours 20 c.c. of 10 per cent. solution of potassium iodide and 150 c.c. water are added to the contents of the bottle, and the excess of iodine titrated with N/10 sodium thiosulphate solution, the whole being well agitated during the titration, which is finished with starch paste as indicator. The blank experiment is titrated in the same manner, and from the amount of thiosulphate required in the blank experiment is deducted the number of c.c. required by the unabsorbed iodine in the other bottle; this figure multiplied by the iodine equivalent of 1 c.c. of the thiosulphate solution and by 100, dividing the product by the weight of fat taken, gives the "Iodine Number". _Example._--1 c.c. of the N/10 sodium thiosulphate solution is found equal to 0.0126 gramme iodine. 0.3187 gramme of fat taken. Blank requires 48.5 c.c. thiosulphate. Bottle containing oil requires 40.0 c.c. thiosulphate. 48.5 - 40.0 = 8.5, and the iodine absorption of the fat is-- 8.5 × 0.0126 × 100 ------------------ = 33.6. 0.3187 Wijs showed that by the employment of a solution of iodine monochloride in glacial acetic acid reliable iodine figures are obtained in a much shorter time, thirty minutes being sufficient, and this method is now in much more general use than the Hübl. Wijs' iodine reagent is made by dissolving 13 grammes iodine in 1 litre of glacial acetic acid and passing chlorine into the solution until the iodine is all converted into iodine monochloride. The process is carried out in exactly the same way as with the Hübl solution except that the fat is preferably dissolved in carbon tetrachloride instead of in chloroform. _Bromine absorption_ has now been almost entirely superseded by the iodine absorption, although there are several good methods. The gravimetric method of Hehner (_Analyst_, 1895, 49) was employed by one of us for many years with very good results, whilst the bromine-thermal test of Hehner and Mitchell (_Analyst_, 1895, 146) gives rapid and satisfactory results. More recently MacIlhiney (_Jour. Amer. Chem. Soc._, 1899, 1084-1089) drew attention to bromine absorption methods and tried to rewaken interest in them. The _Refractive index_ is sometimes useful for discriminating between various oils and fats, and, in conjunction with other physical and chemical data, affords another means of detecting adulteration. Where a great number of samples have to be tested expeditiously, the Abbé refractometer or the Zeiss butyro-refractometer may be recommended on account of the ease with which they are manipulated. The most usual temperature of observations is 60° C. The _Titre_ or setting point of the fatty acids was devised by Dalican, and is generally accepted in the commercial valuation of solid fats as a gauge of firmness, and in the case of tallow has a considerable bearing on the market value. One ounce of the fat is melted in a shallow porcelain dish, and 30 c.c. of a 25 per cent. caustic soda solution added, together with 50 c.c. of redistilled methylated spirit. The whole is stirred down on the water bath until a pasty soap is obtained, when another 50 c.c. of methylated spirit is added, which redissolves the soap, and the whole again stirred down to a solid soap. This is then dissolved in distilled water, a slight excess of dilute sulphuric acid added to liberate the fatty acids, and the whole warmed until the fatty acids form a clear liquid on the surface. The water beneath the fatty acids is then syphoned off, more distilled water added to wash out any trace of mineral acid remaining, and again syphoned off, this process being repeated until the washings are no longer acid to litmus paper, when the fatty acids are poured on to a dry filter paper, which is inserted in a funnel resting on a beaker, and the latter placed on the water-bath, where it is left until the clear fatty acids have filtered through. About 10-15 grammes of the pure fatty acids are now transferred to a test tube, 6" × 1", warmed until molten, and the tube introduced through a hole in the cork into a flask or wide-mouthed bottle. A very accurate thermometer, graduated into fifths of a degree Centigrade (previously standardised), is immersed in the fatty acids, so that the bulb is as near the centre as possible, and when the fatty acids just begin to solidify at the bottom of the tube, the thermometer is stirred round slowly. The mercury will descend, and stirring is continued until it ceases to fall further, at which point the thermometer is very carefully observed. It will be found that the temperature will rise rapidly and finally remain stationary for a short time, after which it will again begin to drop until the temperature of the room is reached. The maximum point to which the temperature rises is known as the "titre" of the sample. ALKALIES AND ALKALI SALTS. Care should be bestowed upon the sampling of solid caustic soda or potash as the impurities during the solidification always accumulate in the centre of the drum, and an excess of that portion must be avoided or the sample will not be sufficiently representative. The sampling should be performed expeditiously to prevent carbonating, and portions placed in a stoppered bottle. The whole should be slightly broken in a mortar, and bright crystalline portions taken for analysis, using a stoppered weighing bottle. _Caustic Soda and Caustic Potash._--These substances are valued according to the alkali present in the form of caustic (hydrate) and carbonate. About 2 grammes of the sample are dissolved in 50 c.c. distilled water, and titrated with N/1 sulphuric acid, using phenol-phthalein as indicator, the alkalinity so obtained representing all the caustic alkali and one-half the carbonate, which latter is converted into bicarbonate. One c.c. N/1 acid = 0.031 gramme Na_{2}O or 0.040 gramme NaOH and 0.047 gramme K_{2}O, or 0.056 gramme KOH. After this first titration, the second half of the carbonate may be determined in one of two ways, either:-- (1) By adding from 3-5 c.c. of N/10 acid, and well boiling for five minutes to expel carbonic-acid gas, after which the excess of acid is titrated with N/10 soda solution; or (2) After adding two drops of methyl orange solution, N/10 acid is run in until the solution acquires a faint pink tint. In the calculation of the caustic alkali, the number of c.c. of acid required in the second titration, divided by 10, is subtracted from that used in the first, and this difference multiplied by 0.031, or 0.047 gives the amount of Na_{2}O or K_{2}O respectively in the weight of sample taken, whence the percentage may be readily calculated. The proportion of carbonate is calculated by multiplying the amount of N/10 acid required in the second titration by 2, and then by either 0.0031 or 0.0047 to give the amount of carbonate present, expressed as Na_{2}O or K_{2}O respectively. An alternative method is to determine the alkalinity before and after the elimination of carbonate by chloride of barium. About 7-8 grammes of the sample are dissolved in water, and made up to 100 c.c., and the total alkalinity determined by titrating 20 c.c. with N/1 acid, using methyl orange as indicator. To another 20 c.c. is added barium chloride solution (10 per cent.) until it ceases to give a precipitate, the precipitate allowed to settle, and the clear supernatant liquid decanted off, the precipitate transferred to a filter paper and well washed, and the filtrate titrated with N/1 acid, using phenol-phthalein as indicator. The second titration gives the amount of caustic alkali present, and the difference between the two the proportion of carbonate. When methyl orange solution is used as indicator, titrations must be carried out cold. Reference has already been made (p. 39) to the manner in which the alkali percentage is expressed in English degrees in the case of caustic soda. _Chlorides_ are estimated by titrating the neutral solution with N/10 silver nitrate solution, potassium chromate being used as indicator. One c.c. N/10 AgNO_{3} solution = 0.00585 gramme sodium chloride. The amount of acid necessary for exact neutralisation having already been ascertained, it is recommended to use the equivalent quantity of N/10 nitric acid to produce the neutral solution. _Sulphides_ may be tested for, qualitatively, with lead acetate solution. _Aluminates_ are determined gravimetrically in the usual manner; 2 grammes are dissolved in water, rendered acid with HCl, excess of ammonia added, and the gelatinous precipitate of aluminium hydrate collected on a filter paper, washed, burnt, and weighed. * * * * * _Carbonated Alkali (Soda Ash)._--The total or available alkali is, of course, the chief factor to be ascertained, and for this purpose it is convenient to weigh out 3.1 grammes of the sample, dissolve in 50 c.c. water, and titrate with N/1 sulphuric or hydrochloric acid, using methyl orange as indicator. Each c.c. of N/1 acid required represents 1 per cent. Na_{2}O in the sample under examination. A more complete analysis of soda ash would comprise:-- _Insoluble matter_, remaining after 10 grammes are dissolved in warm water. This is washed on to a filter-paper, dried, ignited, and weighed. The filtrate is made up to 200 c.c., and in it may be determined:-- _Caustic soda_, by titrating with N/1 acid the filtrate resulting from the treatment of 20 c.c. (equal to 1 gramme) with barium chloride solution. _Carbonate._--Titrate 20 c.c. with N/1 acid, and deduct the amount of acid required for the Caustic. _Chlorides._--Twenty c.c. are exactly neutralised with nitric acid, titrated with N/10 AgNO_{3} solution, using potassium chromate as indicator. _Sulphates._--Twenty c.c. are acidulated with HCl, and the sulphates precipitated with barium chloride; the precipitate is collected on a filter paper, washed, dried, ignited, and weighed, the result being calculated to Na_{2}SO_{4}. _Sulphides and Sulphites._--The presence of these compounds is denoted by the evolution of sulphuretted hydrogen and sulphurous acid respectively when the sample is acidulated. Sulphides may also be tested for, qualitatively, with lead acetate solution, or test-paper of sodium nitro-prusside. The total quantity of these compounds may be ascertained by acidulating with acetic acid, and titrating with N/10 iodine solution, using starch paste as indicator. One c.c. N/10 iodine solution = 0.0063 gramme Na_{2}SO_{3}. The amount of sulphides may be estimated by titrating the hot soda solution, to which ammonia has been added, with an ammoniacal silver nitrate solution, 1 c.c. of which corresponds to 0.005 gramme Na_{2}S. As the titration proceeds, the precipitate is filtered off, and the addition of ammoniacal silver solution to the filtrate continued until a drop produces only a slight opacity. The presence of chloride, sulphate, hydrate, or carbonate does not interfere with the accuracy of this method. The ammoniacal silver nitrate solution is prepared by dissolving 13.345 grammes of pure silver in pure nitric acid, adding 250 c.c. liquor ammoniæ fortis, and diluting to 1 litre. _Carbonate of Potash (Pearl Ash)._--The total or available alkali may be estimated by taking 6.9 grammes of the sample, and titrating with N/1 acid directly, or adding 100 c.c. N/1 sulphuric acid, boiling for a few minutes, and titrating the excess of acid with N/1 caustic soda solution, using litmus as indicator. In this case each c.c. N/1 acid required, is equivalent, in the absence of Na_{2}CO_{3}, to 1 per cent. K_{2}CO_{3}. Carbonate of potash may be further examined for the following:-- _Moisture._--From 2-3 grammes are heated for thirty minutes in a crucible over a gas flame, and weighed when cold, the loss in weight representing the moisture. _Insoluble residue_, remaining after solution in water, filtering and well washing. _Potassium_ may be determined by precipitation as potassium platino-chloride thus:--Dissolve 0.5 gramme in a small quantity (say 10 c.c.) of water, and carefully acidulate with hydrochloric acid, evaporate the resultant liquor to dryness in a tared platinum basin, and heat the residue gradually to dull redness. Cool in a desicator, weigh, and express the result as "mixed chlorides," _i.e._ chlorides of soda and potash. To the mixed chlorides add 10 c.c. water, and platinic chloride in excess (the quantity may be three times the amount of the mixed chlorides) and evaporate nearly to dryness; add 15 c.c. alcohol and allow to stand three hours covered with a watch-glass, giving the dish a gentle rotatory movement occasionally. The clear liquid is decanted through a tared filter, and the precipitate well washed with alcohol by decantation, and finally transferred to the filter, dried and weighed. From the weight of potassium platino-chloride, K_{2}PtCl_{6}, is calculated the amount of potassium oxide K_{2}O by the use of the factor 94/488.2 or 0.19254. _Chlorides_, determined with N/10 silver nitrate solution, and calculated to KCl. _Sulphates_, estimated as barium sulphate, and calculated to K_{2}SO_{4}. _Sodium Carbonate_, found by deducting the K_{2}CO_{3} corresponding to the actual potassium as determined above, from the total alkali. _Iron_, precipitated with excess of ammonia, filtered, ignited, and weighed as Fe_{2}O_{3}. SODIUM CHLORIDE (COMMON SALT). This should be examined for the following:-- _Actual Chloride_, either titrated with N/10 silver nitrate solution, using neutral potassium chromate solution as indicator, or, preferably, estimated gravimetrically as silver chloride by precipitation with silver nitrate solution, the precipitate transferred to a tared filter paper, washed, dried and weighed. _Insoluble matter_, remaining on dissolving 5 grammes in water, and filtering. This is washed, dried, ignited and weighed. _Moisture._--5 grammes are weighed into a platinum crucible, and heat gently applied. The temperature is gradually increased to a dull red heat, which is maintained for a few minutes, the dish cooled in a desicator, and weighed. _Sulphates_ are estimated by precipitation as barium sulphate and calculated to Na_{2}SO_{4}. _Sodium._--This may be determined by converting the salt into sodium sulphate by the action of concentrated sulphuric acid, igniting to drive off hydrochloric and sulphuric acids, and fusing the mass until constant in weight, weighing finally as Na_{2}SO_{4}. POTASSIUM CHLORIDE. This should be examined, in the same way as sodium chloride, for chloride, insoluble matter, moisture, and sulphate. The potassium may be determined as potassium platino-chloride, as described under carbonate of potash. SILICATES OF SODA AND POTASH. The most important determinations for these are total alkali and silica. _Total alkali_ is estimated by dissolving 2 grammes in distilled water, and titrating when cold, with N/1 acid, using methyl orange as indicator. _Silica_ may be determined by dissolving 1 gramme in distilled water, rendering the solution acid with HCl, and evaporating to complete dryness on the water-bath, after which the residue is moistened with HCl and again evaporated, this operation being repeated a third time. The residue is then heated to about 150° C., extracted with hot dilute HCl, filtered, thoroughly washed, dried, ignited in a tared platinum crucible, and weighed as SiO_{2}. ESSENTIAL OILS. As already stated, these are very liable to adulteration, and an examination of all kinds of oil is desirable, while in the case of the more expensive varieties it should never be omitted. _Specific Gravity._--As with fats and oils, this is usually taken at 15° C., and compared with water at the same temperature. In the case of otto of rose and guaiac wood oil, however, which are solid at this temperature, it is generally observed at 30° C. compared with water at 15° C. The specific gravity is preferably taken in a bottle or U-tube, but if sufficient of the oil is available and a high degree of accuracy is not necessary, it may be taken either with a Westphal balance, or by means of a hydrometer. _Optical Rotation._--For this purpose a special instrument, known as a polarimeter, is required, details of the construction and use of which would be out of place here. Suffice it to mention that temperature plays an important part in the determination of the optical activity of certain essential oils, notably in the case of lemon and orange oils. For these Gildemeister and Hoffmann give the following corrections:-- Lemon oil, below 20° C. subtract 9' for each degree below, above 20° C. add 8' for each degree above. Orange oil, below 20° C. subtract 14' for each degree below, above 20° C. add 13' for each degree above. _Refractive Index._--This figure is occasionally useful, and is best determined with an Abbé refractometer, at 20° C. _Solubility in Alcohol._--This is found by running alcohol of the requisite strength from a burette into a measured volume of the oil with constant agitation, until the oil forms a clear solution with the alcohol. Having noted the quantity of alcohol added, it is well to run in a small further quantity of alcohol, and observe whether any opalescence or cloudiness appears. _Acid_, _ester_, and _saponification values_ are determined exactly as described under fats and oils. Instead of expressing the result as saponification value or number, the percentage of ester, calculated in the form of the most important ester present, may be obtained by multiplying the number of c.c. of N/1 alkali absorbed in the saponification by the molecular weight of the ester. Thus, to find the percentage as linalyl acetate, the number of c.c. absorbed would be multiplied by 0.196 and by 100, and divided by the weight of oil taken. _Alcohols._--For the estimation of these, if the oil contains much ester it must first be saponified with alcoholic potash, to liberate the combined alcohols, and after neutralising the excess of alkali with acid, the oil is washed into a separating funnel with water, separated, dried with anhydrous sodium sulphate, and is then ready for the alcohol determination. If there is only a small quantity of ester present, this preliminary saponification is unnecessary. The alcohols are estimated by conversion into their acetic esters, which are then saponified with standard alcoholic potash, thereby furnishing a measure of the amount of alcohol esterified. Ten c.c. of the oil is placed in a flask with an equal volume of acetic anhydride, and 2 grammes of anhydrous sodium acetate, and gently boiled for an hour to an hour and a half. After cooling, water is added, and the contents of the flask heated on the water-bath for fifteen to thirty minutes, after which they are cooled, transferred to a separating funnel, and washed with a brine solution until the washings cease to give an acid reaction with litmus paper. The oil is now dried with anhydrous sodium sulphate, filtered, and 1-2 grammes weighed into a flask and saponified with alcoholic potash as in the determination of ester or saponification value. The calculation is a little complicated, but an example may perhaps serve to make it clear. A geranium oil containing 26.9 per cent. of ester, calculated as geranyl tiglate, was acetylated, after saponification, to liberate the combined geraniol, and 2.3825 grammes of the acetylated oil required 9.1 c.c. of N/1 alkali for its saponification. Now every 196 grammes of geranyl acetate present in the acetylated oil correspond to 154 grammes of geraniol, so that for every 196 grammes of ester now present in the oil, 42 grammes have been added to its weight, and it is therefore necessary to make a deduction from the weight of oil taken for the final saponification to allow for this, and since each c.c. of N/1 alkali absorbed corresponds to 0.196 gramme of geranyl acetate, the amount to be deducted is found by multiplying the number of c.c. absorbed by 0.042 gramme, the formula for the estimation of total alcohols thus becoming in the example given:-- 9.1 × 0.154 × 100 Per cent. of geraniol = ---------------------- = 70.2 2.3825 - (9.1 × 0.042) The percentage of combined alcohols can be calculated from the amount of ester found, and by subtracting this from the percentage of total alcohols, that of the free alcohols is obtained. In the example quoted, the ester corresponds to 17.6 per cent. geraniol, and this, deducted from the total alcohols, gives 52.6 per cent. free alcohols, calculated as geraniol. This process gives accurate results with geraniol, borneol, and menthol, but with linalol and terpineol the figures obtained are only comparative, a considerable quantity of these alcohols being decomposed during the acetylation. The aldehyde citronellal is converted by acetic anhydride into isopulegol acetate, so that this is also included in the determination of graniol in citronella oil. _Phenols._--These bodies are soluble in alkalies, and may be estimated by measuring 5 c.c. or 10 c.c. of the oil into a Hirschsohn flask (a flask of about 100 c.c. capacity with a long narrow neck holding 10 c.c., graduated in tenths of a c.c.), adding 25 c.c. of a 5 per cent. aqueous caustic potash solution, and warming in the water-bath, then adding another 25 c.c., and after one hour in the water-bath filling the flask with the potash solution until the unabsorbed oil rises into the neck of the flask, the volume of this oil being read off when it has cooled down to the temperature of the laboratory. From the volume of oil dissolved the percentage of phenols is readily calculated. _Aldehydes._--In the estimation of these substances, use is made of their property of combining with sodium bisulphite to form compounds soluble in hot water. From 5-10 c.c. of the oil is measured into a Hirschsohn flask, about 30 c.c. of a hot saturated solution of sodium bisulphite added, and the flask immersed in a boiling water bath, and thoroughly shaken at frequent intervals. Further quantities of the bisulphite solution are gradually added, until, after about one hour, the unabsorbed oil rises into the neck of the flask, where, after cooling, its volume is read off, and the percentage of absorbed oil, or aldehydes, calculated. In the case of lemon oil, where the proportion of aldehydes, though of great importance, is relatively very small, it is necessary to first concentrate the aldehydes before determining them. For this purpose, 100 c.c. of the oil is placed in a Ladenburg fractional distillation flask, and 90 c.c. distilled off under a pressure of not more than 40 mm., and the residue steam distilled. The oil so obtained is separated from the condensed water, measured, dried, and 5 c.c. assayed for aldehydes either by the process already described, or by the following process devised by Burgess (_Analyst_, 1904, 78):-- Five c.c. of the oil are placed in the Hirschsohn flask, about 20 c.c. of a saturated solution of neutral sodium sulphite added, together with a few drops of rosolic acid solution as indicator, and the flask placed in a boiling water-bath and continually agitated. The contents of the flask soon become red owing to the liberation of free alkali by the combination of the aldehyde with part of the sodium sulphite, and this coloration is just discharged by the addition of sufficient 10 per cent. acetic-acid solution. The flask is again placed in the water-bath, the shaking continued, and any further alkali liberated neutralised by more acetic acid, the process being continued in this way until no further red colour is produced. The flask is then filled with the sodium sulphite solution, the volume of the cooled unabsorbed oil read off, and the percentage of aldehydes calculated as before. _Solidifying Point, or Congealing Point._--This is of some importance in the examination of anise and fennel oils, and is also useful in the examination of otto of rose. A suitable apparatus may be made by obtaining three test tubes, of different sizes, which will fit one inside the other, and fixing them together in this way through corks. The innermost tube is then filled with the oil, and a sensitive thermometer, similar to that described under the Titre test for fats, suspended with its bulb completely immersed in the oil. With anise and fennel, the oil is cooled down with constant stirring until it just starts crystallising, when the stirring is interrupted, and the maximum temperature to which the mercury rises noted. This is the solidifying point. In the case of otto of rose, the otto is continually stirred, and the point at which the first crystal is observed is usually regarded as the congealing point. _Melting Point._--This is best determined by melting some of the solid oil, or crystals, and sucking a small quantity up into a capillary tube, which is then attached by a rubber band to the bulb of the thermometer, immersed in a suitable bath (water, glycerine, oil, etc.) and the temperature of the bath gradually raised until the substance in the tube is sufficiently melted to rise to the surface, the temperature at which this takes place being the melting point. The melting point of otto of rose is usually taken in a similar tube to the setting point, and is considered to be the point at which the last crystal disappears. _Iodine Absorption._--In the authors' opinion, this is of some value in conjunction with other data in judging of the purity of otto of rose. It is determined by Hübl's process as described under Fats and Oils, except that only 0.1 to 0.2 gramme is taken, and instead of 10 c.c. of chloroform, 10 c.c. of pure alcohol are added. The rest of the process is identical. SOAP. In the analysis of soap, it is a matter of considerable importance that all the determinations should be made on a uniform and average sample of the soap, otherwise very misleading and unreliable figures are obtained. Soap very rapidly loses its moisture on the surface, while the interior of the bar or cake may be comparatively moist, and the best way is to carefully remove the outer edges and take the portions for analysis from the centre. In the case of a household or unmilled toilet soap, it is imperative that the quantities for analysis should all be weighed out as quickly after each other as possible. _Fatty Acids._--Five grammes of the soap are rapidly weighed into a small beaker, distilled water added, and the beaker heated on the water bath until the soap is dissolved. A slight excess of mineral acid is now added, and the whole heated until the separated fatty acids are perfectly clear, when they are collected on a tared filter paper, well washed with hot water and dried until constant in weight. The result multiplied by 20 gives the percentage of fatty acids in the sample. A quicker method, and one which gives accurate results when care is bestowed upon it, is to proceed in the manner described above as far as the decomposition with mineral acid, and to then add 5 or 10 grammes of stearic acid or beeswax to the contents of the beaker and heat until a clear layer of fatty matter collects upon the acid liquor. Cool the beaker, and when the cake is sufficiently hard, remove it carefully by means of a spatula and dry on a filtering paper, add the portions adhering to the sides of the beaker to the cake, and weigh. The weight, less the amount of stearic acid or beeswax added, multiplied by 20 gives the percentage of fatty acids. Care must be taken that the cake does not contain enclosed water. The results of these methods are returned as fatty acids, but are in reality insoluble fatty acids, the soluble fatty acids being generally disregarded. However in soaps made from cocoa-nut and palm-kernel oils (which contain an appreciable quantity of soluble fatty acids) the acid liquor is shaken with ether, and, after evaporation of the ethereal extract, the amount of fatty matter left is added to the result already obtained as above, or the ether method described below may be advantageously employed. Where the soap under examination contains mineral matter, the separated fatty acids may be dissolved in ether. This is best performed in an elongated, graduated, stoppered tube, the total volume of the ether, after subsidence, carefully read, and an aliquot part taken and evaporated to dryness in a tared flask, which is placed in the oven at 100° C. until the weight is constant. In a complete analysis, the figure for fatty acids should be converted into terms of fatty anhydrides by multiplying by the factor 0.9875. In this test the resin acids contained in the soap are returned as fatty acids, but the former can be estimated, as described later, and deducted from the total. _Total Alkali._--The best method is to incinerate 5 grammes of the soap in a platinum dish, dissolve the residue in water, boil and filter, making the volume of filtrate up to 250 c.c., the solution being reserved for the subsequent determination of salt, silicates, and sulphates, as detailed below. Fifty c.c. of the solution are titrated with N/1 acid, to methyl orange, and the result expressed in terms of Na_{2}O. Number of c.c. required × 0.031 × 100 = per cent. Na_{2}O. The total alkali may also be estimated in the filtrate from the determination of fatty acids, if the acid used for decomposing the soap solution has been measured and its strength known, by titrating back the excess of acid with normal soda solution, when the difference will equal the amount of total alkali in the quantity taken. The total alkali is usually expressed in the case of hard soaps as Na_{2}O, and in soft soaps as K_{2}O. _Free caustic alkali_ is estimated by dissolving 2 grammes of the soap, in neutral pure alcohol, with gentle heat, filtering, well washing the filter with hot neutral spirit, and titrating the filtrate with N/10 acid, to phenol-phthalein. Number of c.c. required × 0.0031 × 50 = per cent. free alkali Na_{2}O, as caustic. _Free Carbonated Alkali._--The residue on the filter paper from the above determination is washed with hot water, and the aqueous filtrate titrated with N/10 acid, using methyl orange as indicator. The result is generally expressed in terms of Na_{2}O. Number of c.c. required × 0.0031 × 50 = per cent. free alkali Na_{2}O, as carbonate. _Free Alkali._--Some analysts determine the alkalinity to phenol-phthalein of the alcoholic soap solution without filtering, and express it as free alkali (caustic, carbonates, or any salt having an alkaline reaction). _Combined Alkali._--The difference between total alkali and free alkali (caustic and carbonate together) represents the alkali combined with fatty acids. This figure may also be directly determined by titrating, with N/2 acid, the alcoholic solution of soap after the free caustic estimation, using lacmoid as indicator. The potash and soda in soaps may be separated by the method described for the estimation of potassium in _Pearl ash_ (page 126). The potassium platino-chloride (K_{2}PtCl_{6}) is calculated to potassium chloride (KCl) by using the factor 0.3052, and this figure deducted from the amount of mixed chlorides found, gives the amount of sodium chloride (NaCl), from which the sodium oxide (Na_{2}O) is obtained by multiplying by 0.52991. The potassium chloride (KCl) is converted into terms of potassium oxide (K_{2}O) by the use of the factor 0.63087. _Salt_ may be determined in 50 c.c. of the filtered aqueous extract of the incinerated soap, by exactly neutralising with normal acid and titrating with N/10 silver nitrate solution, using a neutral solution of potassium chromate as indicator. The final reaction is more distinctly observed if a little bicarbonate of soda is added to the solution. Number of c.c. required × 0.00585 × 100 = per cent. of common salt, NaCl. Chlorides may also be estimated by Volhard's method, the aqueous extract being rendered slightly acid with nitric acid, a measured volume of N/10 silver nitrate solution added, and the excess titrated back with N/10 ammonium thiocyanate solution, using iron alum as indicator. _Silicates._--These are estimated by evaporating 50 c.c. of the filtered extract from the incinerated soap, in a platinum dish with hydrochloric acid twice to complete dryness, heating to 150° C., adding hot water, and filtering through a tared filter paper. The residue is well washed, ignited, and weighed as SiO_{2}, and from this silica is calculated the sodium silicate. _Sulphates_ may be determined in the filtrate from the silica estimation by precipitation with barium chloride solution, and weighing the barium sulphate, after filtering, and burning, expressing the result in terms of Na_{2}SO_{4} by the use of the factor 0.6094. _Moisture._--This is simply estimated by taking a weighed portion in small shavings in a tared dish, and drying in the oven at 105° C. until it ceases to lose weight. From the loss thus found is calculated the moisture percentage. _Free or Uncombined Fat._--This is usually determined by repeated extraction of an aqueous solution of the soap with petroleum ether; the ethereal solution, after washing with water to remove traces of soap, is evaporated to dryness and the residue weighed. A good method, which can be recommended for employment where many determinations have to be performed, is to dissolve 10 grammes of soap in 50 c.c. neutral alcohol and titrate to phenol-phthalein with N/1 acid. Add 3-5 drops HCl and boil to expel carbonic acid, neutralise with alcoholic KOH solution and add exactly 10 c.c. in excess, boil for fifteen minutes under a reflux condenser and titrate with N/1 acid. The difference between this latter figure and the amount required for a blank test with 10 c.c. alcoholic KOH, denotes the amount of alkali absorbed by the uncombined fat. _Examination of the fatty acids_ as a guide to the probable composition of the soap:-- From the data obtained by estimating the "titre," iodine number, and saponification equivalent of the mixed fatty and rosin acids, and the rosin content, a fairly good idea of the constitution of the soap may be deduced. The titre, iodine number, and saponification equivalent are determined in exactly the same manner as described under Fats and Oils. The presence of rosin may be detected by the Liebermann-Storch reaction, which consists in dissolving a small quantity of the fatty acids in acetic anhydride, and adding to a few drops of this solution 1 drop of 50 per cent. sulphuric acid. A violet coloration is produced with rosin acids. The amount of rosin may be estimated by the method devised by Twitchell (_Journ. Soc. Chem. Ind._, 1891, 804) which is carried out thus:-- Two grammes of the mixed fatty and rosin acids are dissolved in 20 c.c. absolute alcohol, and dry hydrochloric acid gas passed through until no more is absorbed, the flask being kept cool by means of cold water to prevent the rosin acids being acted upon. The flask, after disconnecting, is allowed to stand one hour to ensure complete combination, when its contents are transferred to a Philips' beaker, well washed out with water so that the volume is increased about five times, and boiled until the acid solution is clear, a fragment of granulated zinc being added to prevent bumping. The heat is removed, and the liquid allowed to cool, when it is poured into a separator, and the beaker thoroughly rinsed out with ether. After shaking, the acid liquor is withdrawn, and the ethereal layer washed with water until free from acid. Fifty c.c. neutral alcohol are added, and the solution titrated with N/1 KOH or NaOH solution, the percentage of rosin being calculated from its combining weight. Twitchell suggests 346 as the combining weight of rosin, but 330 is a closer approximation. The method may be also carried out gravimetrically, in which case petroleum ether, boiling at 74° C. is used for washing out the beaker into the separator. The acid liquor is run off, and the petroleum ether layer washed first with water and then with a solution of 1/2 gramme KOH and 5 c.c. alcohol in 50 c.c. water, and agitated. The rosin is thus saponified and separated. The resinate solution is withdrawn, acidified, and the resin acids collected, dried and weighed. _Halphen's Reaction._--This is a special test to determine the presence or absence of cotton-seed oil fatty acids in mixtures. Equal parts of the fatty acids, amyl alcohol, and a 1 per cent. solution of sulphur in carbon bisulphide, are heated in a test-tube placed in a water-bath until effervescence ceases, then in boiling brine for one hour or longer when only small quantities are present. The presence of cotton-seed oil is denoted by a pink coloration. The reaction is rendered much more rapid, according to Rupp (_Z. Untersuch. Nahr. Genussm._, 1907, 13, 74), by heating in a stoppered flask. Other bodies which it is occasionally necessary to test for or determine in soap include:-- _Carbolic acid._--Fifty grammes of the soap are dissolved in water and 20 c.c. of 10 per cent. caustic potash added. The solution is treated with an excess of brine, the supernatant liquor separated, and the precipitate washed with brine, the washings being added to the liquor withdrawn. This is then evaporated to a small bulk, placed in a Muter's graduated tube, and acidified with mineral acid. The volume of separated phenols is observed and stated in percentage on the soap taken. Or the alkaline layer may be rendered acid and steam distilled; the distillate is made up to a known volume, and a portion titrated by the Koppeschaar method with standard bromine water. _Glycerine._--Five grammes of soap are dissolved in water, decomposed with dilute sulphuric acid, and the clear fatty acids filtered and washed. The filtrate is neutralised with barium carbonate, evaporated to 50 c.c., and the glycerol estimated by the bichromate method detailed under Crude Glycerine. _Starch_ or _gum_ may be detected by dissolving the soap in alcohol, filtering, and examining the residue on the filter paper. Starch is readily recognised by the blue coloration it gives with a solution of iodine in potassium iodide. _Sugars_ are tested for by means of Fehlings' solution, in the liquor separated from the fatty acids, after first boiling with dilute acid to invert any cane sugar. _Mercury_ will be revealed by a black precipitate produced when sulphuretted hydrogen is added to the liquor separated from the fatty acids, and may be estimated by filtering off this precipitate on a tared Gooch's crucible, which is then dried and weighed. _Borax or borates_ are tested for in the residue insoluble in alcohol. This is dissolved in water, rendered faintly acid with dilute hydrochloric acid, and a strip of turmeric paper immersed for a few minutes in the liquid. This is then dried in the water-oven, when if any boric acid compound is present, a bright reddish-pink stain is produced on the paper, which is turned blue on moistening with dilute alkali. The amount of the boric acid radicle may be determined by incinerating 5-10 grammes of soap, extracting with hot dilute acid, filtering, neutralising this solution to methyl orange, and boiling to expel carbon dioxide. After cooling, sufficient pure neutralised glycerine is added to form one-third of the total volume, and the liquid titrated with N/2 caustic soda solution, using phenol-phthalein as indicator. Each c.c. of N/2 NaOH solution corresponds to 0.031 gramme crystallised boric acid, H_{3}BO_{3} or 0.0477 gramme crystallised borax, Na_{2}B_{4}O_{7}·10H_{2}O. LYES. The amounts of caustic alkali (if any), carbonated alkali, and salt present are determined in the manner already described under Alkali and Alkali Salts. The glycerol content is ascertained by taking 2.5 grammes, adding lead subacetate solution, and filtering without increasing the bulk more than is absolutely necessary; the solution is concentrated to about 25 c.c., and the oxidation with bichromate and sulphuric acid conducted as described in the examination of Crude Glycerine. The solution, after oxidation, is made up to 250 c.c., and titrated against standard ferrous ammonium sulphate solution, the formula for the calculation being:-- {0.25 - 2.5} Per cent. of glycerol = { ---} × 40 { n } where n equals the number of c.c. of oxidised lyes required to oxidise the ferrous ammonium sulphate solution. The estimation of actual glycerol in this is necessarily a matter of considerable importance, and a very large number of processes, which are constantly being added to, have been suggested for the purpose. Hitherto, however, only two methods have been generally adopted, _viz._ the acetin and the bichromate processes. Unfortunately the results obtained by these do not invariably agree, the latter, which includes all oxidisable matter as glycerol, giving sometimes considerably higher results, and it has been suggested that a determination should be made by both methods, and the average of the two results considered the true value. This involves a considerable amount of time and trouble, and it will generally be found sufficient in a works laboratory to determine the glycerol by one method only in the ordinary course, reserving the other process for use as a check in case of dispute or doubt. _Acetin Method._--This consists in converting the glycerol into its ester with acetic acid, the acetic triglyceride, or triacetin being formed. This is then saponified with a known volume of standard alkali, the excess of which is titrated with acid, and the percentage of glycerol calculated from the amount of alkali absorbed. From 1 to 1.5 grammes of the glycerine is weighed into a conical flask of about 150 c.c. capacity, 7 or 8 c.c. of acetic anhydride added, together with about 3 grammes of anhydrous sodium acetate, and the whole boiled on a sand-bath under a reflux condenser for one to one and a half hours, after which it is allowed to cool, 50 c.c. water added, and the ester dissolved by shaking, and gently warming, the reflux condenser still being attached as the acetin is very volatile. The solution is then filtered from a white flocculent precipitate, which contains most of the impurities, into a larger conical flask, of some 500-600 c.c. capacity, and after cooling, rendered just neutral to phenol-phthalein by means of N/2 caustic soda solution, the exact point being reached when the solution acquires a reddish-yellow tint; 25 c.c. of a strong caustic soda solution is then added, and the liquid boiled for about fifteen minutes, the excess of alkali being titrated after cooling, with N/1 or N/2 hydrochloric acid. A blank experiment is carried out simultaneously, with another 25 c.c. of the soda solution, and the difference in the amounts of acid required by the two, furnishes a measure of the alkali required to saponify the acetin formed, and hence the amount of glycerol in the crude glycerine may be calculated. _Example._--1.4367 grammes crude glycerine, after treatment with acetic anhydride, and neutralising, was saponified with 25 c.c. of a 10 per cent. caustic soda solution. The blank experiment required 111.05 c.c. N/1 hydrochloric acid. Flask containing acetin " 75.3 c.c. " " ----- 35.75 c.c. " " Hence, the acetin formed from the glycerol present in 1.4367 grammes of the crude glycerine required 35.75 c.c. N/1 caustic alkali for its saponification, so that the percentage of glycerol may be calculated from the following formula:-- 35.75 × 0.03067 × 100 Per cent. glycerol = --------------------- = 76.3. 1.4367 _Bichromate Method._--This process was originally devised by Hehner (_Journ. Soc. Chem. Ind._, 1889, 4-9), but the modification suggested by Richardson and Jaffe (_ibid._, 1898, 330) is preferred by the authors, and has been practised by them for several years with perfectly satisfactory results. Twenty-five grammes of the crude glycerine are weighed out in a beaker, washed into a 250 c.c. stoppered flask, and made up to the graduation mark with water. Twenty-five c.c. of this solution are then measured from a burette into a small beaker, a slight excess of basic lead acetate solution added to precipitate organic matter, the precipitate allowed to settle, and the supernatant liquid poured through a filter paper into another 250 c.c. flask. The precipitate is washed by decantation until the flask is nearly full, then transferred to the filter, and allowed to drain, a few drops of dilute sulphuric acid being added to precipitate the slight excess of basic lead acetate solution, and the contents of the flask made up with water to 250 c.c. This solution is filtered, 20 c.c. measured from a burette into a conical flask of about 150 c.c. capacity, 25 c.c. of a standard potassium bichromate solution containing 74.86 grammes bichromate per litre added, together with 50 c.c. of 50 per cent. sulphuric acid, and the whole placed in a boiling water-bath for one hour, after which it is allowed to cool, diluted with water to 250 c.c., and this solution run in to 20 c.c. of a 3 per cent. ferrous ammonium sulphate solution until the latter is completely oxidised, as shown by no blue coloration being produced when one drop is brought into contact with one drop of a freshly prepared solution of potassium ferricyanide on a spot-plate. The ferrous ammonium sulphate solution is previously standardised by titration with a potassium bichromate solution of one-tenth the above strength, made by diluting 10 c.c. of the strong solution to 100 c.c. with water. The reaction taking place in the oxidation may be represented by the equation:-- 3C_{3}H_{5}(OH)_{3} + 7K_{2}Cr_{2}O_{7} + 28H_{2}SO_{4} = 9CO_{2} + 40H_{2}O + 7K_{2}SO_{4} + 7Cr_{2}(SO_{4})_{3}. Now the strong potassium bichromate solution above mentioned is of such a strength that 1 c.c. will oxidise 0.01 gramme glycerine, and 20 c.c. of the ferrous ammonium sulphate solution should require about 10 c.c. of the one-tenth strength bichromate in the blank experiment. If it requires more or less than this, then the amount of ferrous ammonium sulphate solution which would require exactly 10 c.c. (corresponding to 0.01 gramme glycerine) is calculated, and the oxidised glycerine solution run into this until oxidation is complete. The formula for the calculation of the percentage of glycerol then becomes:-- {0.25 -(250 × 0.01)} Per cent. of glycerol = { ---------- } × 500, { n } where n equals the number of c.c. of oxidised glycerine solution required to oxidise the ferrous ammonium sulphate solution. Example:-- In the blank experiment 20 c.c. ferrous ammonium sulphate solution required 9.8 c.c. one-tenth strength bichromate solution, so that 20.4 c.c. ferrous solution would equal 10 c.c. bichromate. 20.4 c.c. ferrous solution required 27.8 c.c. of oxidised glycerine solution before it ceased to give a blue coloration with potassium ferricyanide. {0.25 - (250 × 0.01)} Therefore, per cent. of glycerol = { ------------} × 500 { 27.8 } = 80.04 per cent. Other methods have been suggested for the preliminary purification, _e.g._, silver oxide, silver carbonate and lead subacetate, and copper sulphate and caustic potash, but the lead subacetate alone with care gives satisfactory results. Other determinations include those of specific gravity, alkalinity, proportion of salts and chloride, and tests for metals, arsenic, sulphur compounds, sugar, and fatty acids. _Specific gravity_ is determined at 15° C., and may be taken in specific gravity bottle, or with a Westphal balance or hydrometer It usually ranges from 1.3 to 1.31. _Alkalinity_, which is usually sodium carbonate, and may be somewhat considerable if the soap has been grained with caustic alkali, is determined after dilution with water by titrating with N/2 acid, using methyl orange as indicator. _Salts._--These may be determined by gently incinerating 5-6 grammes of the glycerine, extracting the carbonaceous mass with distilled water, filtering, and evaporating the filtrate on the water bath. The dried residue represents the salts in the weight taken. _Chloride of sodium_ (common salt) may be estimated by dissolving the total salts in water, adding potassium chromate, and titrating with N/10 silver nitrate solution. _Copper_, _lead_, _iron_, _magnesium_, and _calcium_ may also be tested for in the salts, by ordinary reactions. _Arsenic_ is best tested for by the Gutzeit method. About 5 c.c. is placed in a test-tube, a few fragments of granulated zinc free from arsenic, and 10 c.c. dilute hydrochloric acid added, and the mouth of the tube covered with a small filter paper, moistened three successive times with an alcoholic solution of mercury bichloride and dried. After thirty minutes the filter paper is examined, when a yellow stain will be observed if arsenic is present. _Sulphates._--These may be precipitated with barium chloride in acid solution, in the usual way, dried, ignited, and weighed. _Sulphites_ give with barium chloride a precipitate soluble in hydrochloric acid. If the precipitate is well washed with hot water, and a few drops of iodine solution together with starch paste added, the presence of sulphites is proved by the gradual disappearance of the blue starch-iodine compound first formed. _Thiosulphates_ are detected by precipitating any sulphite and sulphate with barium chloride, filtering, acidifying, and adding a few drops of potassium permanganate solution, when in the presence of a mere trace of thiosulphate, the solution becomes cloudy. _Sulphides._--Lewkowitsch recommends testing for these by replacing the mercury bichloride with lead acetate paper in the Gutzeit arsenic test. Any sulphide causes a blackening of the lead acetate paper. _Sugars_ may be tested for both before and after inversion, by boiling with Fehlings' solution, when no reduction should take place, if pure. _Fatty acids_ are detected by the turbidity they produce when the diluted glycerine is acidified. CHAPTER XI. STATISTICS OF THE SOAP INDUSTRY. Until the year 1853 the amount of soap produced annually in this country was readily obtainable from the official returns collected for the purpose of levying the duty, and the following figures, taken at intervals of ten years for the half century prior to that date, show the steady development of the industry during that period:-- _______________________________________________________________ | | | | | | | Year. | Manufactured. | Consumed. | Exported. | Duty per Ton. | |_______|_______________|___________|___________|_______________| | | | | | | | | Cwts. | Cwts. | Cwts. | £ | | 1801 | 509,980 | 482,140 | 26,790 | 21 | | 1811 | 678,570 | 651,780 | 26,790 | 21 | | 1821 | 875,000 | 839,290 | 35,710 | 28 | | 1831 | 1,098,210 | 955,360 | 142,850 | 28 | | 1841 | 1,776,790 | 1,517,860 | 258,930 | 14 | | 1851 | 1,937,500 | 1,741,070 | 196,430 | 14 | |_______|_______________|___________|___________|_______________| Since the repeal of the soap duty, the revenue from which had reached about £1,000,000 per annum, no accurate means of gauging the production exists, but it is estimated that it has nearly quadrupled during the last fifty-five years, being now some 7,000,000 or 8,000,000 cwt. per annum. The number of soap manufacturers in the United Kingdom is nearly 300, and the amount of capital invested in the industry is roughly estimated to approach £20,000,000 sterling. Official figures are still available for the amount and value of soap annually imported and exported to and from the United Kingdom, the returns for the last eight years being:-- _Imports._ _________________________________________________________________________ | | | | | | | Household. | Toilet. | Total.[13] | | |_____________________|_____________________|_____________________| | Year. | | | | | | | | | Quantity. | Value. | Quantity. | Value. | Quantity. | Value | |_______|___________|_________|___________|_________|___________|_________| | | | | | | | | | | Cwts. | £ | Cwts. | £ | Cwts. | £ | | 1900 | ... | ... | ... | ... | 191,233 | 244,345 | | 1901 | ... | ... | ... | ... | 302,555 | 315,026 | | 1902 | ... | ... | ... | ... | 361,851 | 429,300 | | 1903 | 273,542 | 284,376 | 25,749 | 98,032 | 462,959 | 499,407 | | 1904 | 254,425 | 268,408 | 17,962 | 81,162 | 383,122 | 438,966 | | 1905 | 274,238 | 279,044 | 19,631 | 98,507 | 473,067 | 500,430 | | 1906 | 309,975 | 311,114 | 18,554 | 101,243 | 399,070 | 468,086 | | 1907 | 228,035 | 263,965 | 18,244 | 99,432 | 504,710 | 545,385 | |_______|___________|_________|___________|_________|___________|_________| Household and toilet soaps were not given separately prior to 1903. The imports during the last three years for which complete figures are obtainable, came from the following sources:-- _Household Soap._ ______________________________________________________________ | | | | | | | 1904. | 1905. | 1906. | |________________________________|_________|_________|_________| | | | | | | | £ | £ | £ | | From Netherlands | 4,315 | 3,620 | 3,368 | | France | 14,339 | 17,783 | 24,747 | | Italy | 24,209 | 18,129 | 32,972 | | United States | 218,740 | 235,612 | 242,294 | | Other Foreign Countries | 6,785 | 3,873 | 7,448 | | |_________|_________|_________| | | | | | | Total from Foreign Countries | 268,388 | 279,017 | 310,829 | | Total from British Possessions | 20 | 27 | 285 | | |_________|_________|_________| | | | | | | Total | 268,408 | 279,044 | 311,114 | |________________________________|_________|_________|_________| _Toilet Soap._ ______________________________________________________________ | | | | | | | 1904. | 1905. | 1906. | |________________________________|_________|_________|_________| | | | | | | | £ | £ | £ | | From Germany | 3,509 | 3,516 | 3,001 | | Netherlands | 5,937 | 5,773 | 5,919 | | Belgium | 1,568 | 1,861 | 3,145 | | France | 7,120 | 7,633 | 5,794 | | Italy | 1,176 | 255 | 1,233 | | United States | 59,863 | 74,516 | 78,382 | | Other Foreign Countries | 166 | 147 | 196 | | |_________|_________|_________| | | | | | | Total from Foreign Countries | 79,339 | 93,701 | 97,670 | | Total from British Possessions | 1,823 | 4,411 | 3,225 | | |_________|_________|_________| | | | | | | Total | 81,162 | 98,112 | 100,895 | |________________________________|_________|_________|_________| _Exports._ The exports from the United Kingdom during the past eight years have been as follows:-- _________________________________________________________________________ | | | | | | | Household. | Toilet. | Total.[14] | | |_______________________|____________________|______________________| |Year.| | | | | | | | | Quantity. | Value. | Quantity.| Value. | Quantity. | Value. | |_____|___________|___________|__________|_________|___________|__________| | | | | | | | | | | Cwts. | £ | Cwts. | £ | Cwts. | £ | | 1900| ... | ... | ... | ... | 874,214 | 939,510| | 1901| ... | ... | ... | ... | 947,485 | 999,524| | 1902| ... | ... | ... | ... | 1,051,624 | 1,126,657| | 1903| 998,995 | 900,814 | 38,372 | 217,928 | 1,057,164 | 1,143,661| | 1904| 1,049,022 | 955,774 | 40,406 | 228,574 | 1,108,174 | 1,208,712| | 1905| 1,167,976 | 1,013,837 | 43,837 | 248,425 | 1,230,310 | 1,284,727| | 1906| 1,131,294 | 1,009,653 | 46,364 | 261,186 | 1,210,598 | 1,309,556| | 1907| 1,114,624 | 1,095,170 | 50,655 | 280,186 | 1,240,805 | 1,459,113| |_____|___________|___________|__________|_________|___________|__________| Household and toilet soaps were not given separately prior to 1903. The exports for the last three years for which complete figures are available, consisted of the following:-- _Household Soap._ +----------------------------------------+----------+----------+-----------+ | | 1904. | 1905. | 1906. | +----------------------------------------+----------+----------+-----------+ | | £ | £ | £ | |To Sweden | 3,027 | 2,911 | 3,677 | | Norway | 4,173 | 3,921 | 6,005 | | Netherlands | 39,420 | 41,197 | 48,601 | | Dutch Possessions in the Indian Seas | 8,586 | 10,293 | 7,746 | | Belgium | 73,996 | 51,583 | 7,729 | | France | 11,741 | 12,222 | 22,907 | | Portuguese East Africa | 28,987 | 42,981 | 40,478 | | Canary Islands | 24,763 | 27,864 | 27,579 | | Italy | 2,842 | 3,187 | 3,962 | | Turkey | 6,974 | 7,858 | 5,897 | | Egypt | 12,110 | 9,467 | 12,035 | | China (exclusive of Hong-Kong and | | | | | Macao) | 49,235 | 114,156 | 89,169 | | United States | 3,885 | 1,975 | 3,924 | | Columbia | 3,601 | 501 | 1,364 | | Ecuador | 3,075 | 3,096 | 6,861 | | Chili | 5,972 | 4,865 | 9,203 | | Brazil | 35,197 | 28,198 | 31,726 | | Argentine Republic | 7,802 | 8,954 | 13,084 | | Other Foreign Countries | 40,058 | 53,914 | 77,687 | | +----------+----------+-----------+ |Total to Foreign Countries | 365,444 | 429,143 | 419,634 | | +---------------------------------+ |To Channel Islands | 5,301 | 8,328 | 7,968 | | Gibraltar | 13,272 | 13,868 | 12,661 | | British West Africa-- | | | | | Gold Coast | 22,598 | 18,513 | 23,423 | | Lagos | 7,751 | 8,032 | 9,518 | | Nigerian Protectorate | 14,942 | 15,299 | 20,951 | | Cape of Good Hope | 158,517 | 143,750 | 136,388 | | Natal | 74,848 | 71,874 | 46,771 | | British India | | | | | Bombay (including Kurachi) | 59,406 | 68,945 | 77,867 | | Madras | 6,364 | 6,697 | 10,355 | | Bengal, Eastern Bengal and Assam. | 26,534 | 23,087 | 22,648 | | Burmah | 26,389 | 35,727 | 37,103 | | Straits Settlements and Dependencies | 26,516 | 32,214 | 39,749 | | Hong-Kong | 14,119 | 15,153 | 15,685 | | British West India Islands | 74,069 | 58,881 | 67,331 | | British Guiana | 12,661 | 12,023 | 11,557 | | Other British Possessions | 47,043 | 52,303 | 50,044 | | +----------+----------+-----------+ |Total to British Possessions | 590,330 | 584,694 | 590,019 | | +----------+----------+-----------+ | Total | 955,774 |1,013,837 |1,009,653 | |----------------------------------------+---------+-----------+-----------+ _Toilet Soap._ ________________________________________________________________ | | | | | | | 1904. | 1905. | 1906. | |__________________________________|_________|_________|_________| | | | | | | | £ | £ | £ | | To Germany | 5,051 | 6,322 | 6,620 | | Belgium | 3,730 | 3,265 | 3,355 | | France | 7,903 | 8,988 | 9,324 | | Portuguese East Africa | 2,215 | 3,973 | 4,658 | | Egypt | 2,302 | 3,350 | 3,525 | | China (exclusive of | | | | | Hong-Kong and Macao) | 3,096 | 3,115 | 3,645 | | Japan (including Formosa) | 3,300 | 4,649 | 3,382 | | United States | 50,043 | 50,668 | 52,124 | | Brazil | 1,879 | 2,241 | 2,292 | | Other Foreign Countries | 22,002 | 26,081 | 29,214 | | |_________|_________|_________| | | | | | | Total to Foreign Countries | 101,521 | 112,652 | 118,139 | | |_________|_________|_________| | | | | | | To Cape of Good Hope | 14,094 | 14,815 | 14,988 | | Natal | 8,897 | 11,913 | 7,280 | | British India-- | | | | | Bombay (including Kurachi) | 24,665 | 24,672 | 28,316 | | Madras | 4,333 | 5,851 | 6,624 | | Bengal, Eastern Bengal | | | | | and Assam | 14,129 | 16,021 | 15,969 | | Burmah | 3,299 | 3,400 | 4,667 | | Straits Settlements and | | | | | Dependencies | 3,590 | 5,092 | 4,798 | | Ceylon and Dependencies | 12,210 | 11,118 | 12,854 | | Australia-- | | | | | Western Australia | 1,549 | 1,394 | 1,137 | | South Australia, (including | | | | | Northern Territory) | 895 | 644 | 637 | | Victoria | 11,989 | 13,614 | 12,774 | | New South Wales | 3,920 | 4,278 | 4,139 | | Queensland | 957 | 1,097 | 1,108 | | Tasmania | 482 | 315 | 547 | | New Zealand | 5,093 | 4,498 | 5,503 | | Canada | 6,382 | 6,196 | 8,185 | | Other British Possessions | 11,069 | 10,855 | 13,521 | | |_________|_________|_________| | | | | | | Total to British Possessions | 127,053 | 135,773 | 143,047 | | |_________|_________|_________| | | | | | | Total | 228,574 | 248,425 | 261,186 | |__________________________________|_________|_________|_________| The following statistics extracted from official consular reports, etc., show the extent of the soap industry in other parts of the world. _United States._--According to the _Oil, Paint and Drug Report_ the total production of soap in the United States during 1905, exclusive of soap products to the value of $1,437,118 made in establishments engaged primarily in the manufacture of other products, reached a value of $68,274,700, made up in the following manner:-- +------------------------------------+--------------+-------------+ | | Quantity. | Value. | +------------------------------------+--------------+-------------+ | | Lbs. | $ | |Hard soaps | ... | 56,878,486 | |Tallow soap | 846,753,798 | 32,610,850 | |Olein soap | 29,363,376 | 1,363,636 | |Foots soap | 85,000,133 | 3,090,312 | |Toilet soaps, including medicated, | | | | shaving, and other special soaps | 130,225,417 | 9,607,276 | |Powdered soaps, sold as such | 120,624,968 | 4,358,682 | |All other soaps | 143,390,957 | 6,097,670 | |Soft soap | 33,613,416 | 667,064 | |Special soap articles | ... | 554,881 | +------------------------------------+--------------+-------------+ _France_.--This country exported common soap during 1906 to the value of £556,000, or £8,000 more than in 1905. The chief centre of the soap industry is Marseilles, which, with about fifty soap factories, produces annually some 3,000,000 cwts. _Germany_ imported in 1905 soap and perfumery to the value of £3,032, that exported amounting to £15,364. In Saxony there are eighty soap factories. _Russia._--There are fifty large soap factories in Russia, the annual output from which is about 2,250,000 cwt. _Roumania._--This country possesses about 230 small and eighteen large soap and candle factories, most of which produce only common soap, there being only one firm--in Bucharest--which makes milled soaps. _Denmark._--In this country there are some 200 small soap factories. _Australia._--According to a Board of Trade report, there were ninety-eight soap and candle factories in Australia in 1905, employing 1,568 hands, and producing 495,036 cwt. of soap. _Queensland._--In 1905 this country contained twenty-one soap and candle works, in which 142 hands were employed, and having an output valued at £86,324. _Hong-Kong._--There are about twenty-four soap factories on this island. _Japan._--A Swiss consular report states that in Japan there are now some fifty soap works, producing about 15,000,000 tablets monthly. _Fiji Islands._--These possess only one soap factory, the output from which is 9 cwt. daily. The following table, compiled from various consular and other official returns, shows the quantity and value of soap imported into different countries and places during the years 1905-7:-- _______________________________________________________________________________ | | | | Household. | Toilet. | Total. |___________________|____________________|____________________ Place and Date. | | | | | | | Quantity.| Value. |Quantity.| Value. |Quantity.| Value. __________________|__________|________|_________|__________|_________|__________ | | | | | | _Europe_-- | | | | | | Cyprus, 1905 | ... | ... | ... | ... | ... | £9,983 Iceland, 1906 | ... | ... | ... | ... | ... | £6,423 Switzerland, | ... | ... | ... | ... |1,702,800| ... 1906 | | | | | kilos. | ... Turkey | ... | ... | ... | ... | About | ... | | | | |1,800,000| ... | | | | | lb. per | | | | | | annum | _Africa_-- | | | | | | Algeria, 1906 | 13,609 |£228,640| ... | ... | ... | ... | tons | | | | | Cape Colony, |15,897,800|£145,000| 427,600 | ... | ... | ... 1906 | lb. | | lb. | | | Gold Coast, 1906| ... | ... | ... | ... | ... | £23,987 Lourenço, | 357,638 | £4,293 | 36,000 | £2,195 | ... | ... Marques, 1906| lb. | | lb. | | | Natal, 1906 |4,263,000 | ... | 9,870 | ... | ... | ... | lb. | | lb. | | | Orange River | 2,382,000| £23,000|1,748 lb.| ... | ... | ... Colony, 1906 | lb. | | | | | Pemba, 1905 | ... | ... | ... | ... | ... | £1,092 Rhodesia, 1906 | 257,600 | ... |2,909 lb.| ... | ... | ... | lb. | | | | | Southern | | | | | | Nigeria, 1905| ... | ... | ... | ... | ... | £11,990 Tangier | ... | ... | ... | ... | ... | £4,554 Transvaal, 1906 | 4,407,000| £81,000| 202,200 | ... | ... | ... | lb. | | lb. | | | Tripoli, 1905 | ... | ... | ... | ... | ... | £6,080 Tunis, 1906 | ... | ... | ... | ... | 1,539 | £23,727 | | | | | tons | Zanzibar, 1906 | ... | ... | ... | ... | ... | £6,102 | | | | | | _America_-- | | | | | | Bahia, 1906 | ... | ... | ... | ... | 1,031 | 606,046 | | | | | tons | milreis Brazil, 1906 | ... | ... | ... | ... | 1,782 | ... | | | | | tons | | | | | |from U.K.| British Guiana, | | | | | | 1906-7 | ... | ... | ... | ... | ... | £13,733 Canada, 1906-7 | ... | ... | ... | ... | ... | $600,999 Columbia, 1906--| | | | | | Cartagena | ... | ... | ... | ... | 65,991 | ... | | | | | tons | Barranquilla | ... | ... | ... | ... | 814,671 | $14,712 | | | | | lb. | Costa Rica, 1906| ... | ... | ... | ... | ... | £1,269 | | | | | | from U.K. | | | | | | Ecuador, 1904 | ... | ... | ... | ... | 759,034 | ... | | | | | kilos. | Granada, 1905 | ... | ... | ... | ... | ... | £3,867 Guatemala, 1906 | ... | £900 | ... | ... | ... | ... Martinique, 1906| 693,269 | £6,955 | ... | ... | ... | ... | kilos. | | | | | Mexico, 1905-6 | ... | £5,982 | ... | ... | ... | ... San Domingo, | ... | ... | ... | ... | 754,587 | 1906 | | | | | lb. | ... St. Vincent, | | | | | | 1905-6 | ... | ... | ... | ... | ... | £1,375 Surinam, 1906 | ... | £3,905 | 1,142 | ... | ... | ... | | | tons | | | Trinidad, 1906-7| ... | ... | ... | ... | ... | £29,967 United States, | | | | | | 1905 | ... |$399,797| ... |$1,071,446| ... |$1,471,243 __________________|__________|________|_________|__________|_________|____________ ________________________________________________________________________________ | | | | Household. | Toilet. | Total |__________________|_________________|________________________ Place and Date. | | | Quan- | | Quan- | | Quantity.| Value.| tity. | Value. | tity | Value. __________________|__________|_______|_______|_________|________|_______________ | | | | | | _Asia_-- | | | | | | Ceylon, 1906 | ... | ... | ... | ... | ... | 423,700 rupees China, 1906 | ... | ... | ... | ... | ... |£216,042 Hangchow, 1906 | ... | ... | ... | ... | ... | £5,888 India, 1906-7 | ... | ... | ... | ... | 183,998| £215,210 | | | | | cwts.| Kiungchow, 1905 | ... | £575 | ... | ... | ... | ... Shanghai, 1905 | ... | ... | ... | ... | ... | £93,256 Smyrna, 1906 | ... | ... | ... | ... |261 tons| ... | | | | | | _Australasia_-- | | | | | | Australia, 1906 | ... | ... |891,117| £65,840 | ... | ... | | | lb. | | | Fiji, 1906 | ... | ... | ... | ... | ... | £1,760 New Zealand, | | | | | | 1905 | ... | ... | ... | ... | ... | £36,843 Philippine | | | | | | Islands, 1905 | ... | ... | ... | ... | ... | £9,137 __________________|__________|_______|_______|_________|________|________ _Exports._ ________________________________________________________________________________ | | | | Household. | Toilet. | Total |___________________|__________________|_____________________ Place and Date. | | | Quan- | | Quan- | | Quantity.| Value. | tity. | Value. | tity. | Value ___________________|__________|________|_______|__________|_______|_____________ | | | | | | _Europe_-- | | | | | | Candia, Crete, | ... | ... | ... | ... | 2,200 | £34,000 1906 | | | | | tons. | Greece | ... | ... | ... | ... | ... | About | | | | | | 500,000 Fr. | | | | | | per annum. Italy, 1907 | 3,992,800| £95,840| ... | ... | ... | ... | kilos. | | | | | Leghorn, 1906 | ... | ... | ... | ... | 1,521 | £37,065 | | | | | tons. | Spain, 1905 | 4,750,996| £98,840| ... | ... | ... | ... | kilos. | | | | | Switzerland, 1906| ... | ... | ... | ... | 77,300| ... | | | | | kilos.| _Africa_-- | | | | | | Cape Colony, 1906| 200 lb. | ... | ... | ... | ... | ... Natal, 1906 |75,225 lb.| ... | ... | ... | ... | ... Seychelles, 1906 | ... | ... | ... | ... |419,329| 129,590 | | | | | kilos.| Rs. _America_-- | | | | | | New Orleans, | ... | ... | ... | ... | ... | £55,534 1906 | | | | | | Perambuco, 1906 | ... | ... | ... | ... | 3,582 |1,087,797,150 | | | | | tons.| rei United States, |44,110,949| ... | ... |$1,042,185| ... | ... 1905 | lb. | | | | | | | | | | | _Asia_-- | | | | | | Japan, 1906 | ... | ... | ... | ... | ... | £83,877 Smyrna, 1906 | ... | ... | ... | ... | 322 | ... | | | | | tons. | ___________________|__________|________|_______|__________|_______|_____________ FOOTNOTES: [13] Including soap powder and soap stock. [14] Including soap powder and soap stock. APPENDIX A. COMPARISON OF DEGREES, TWADDELL AND BAUMÉ, WITH ACTUAL DENSITIES. _______________________________________________ | | | | | | | | Tw. | B. | Density. | Tw. | B. | Density. | |_____|______|__________|_____|______|__________| | | | | | | | | 0 | 0 | 1.000 | 44 | 26.0 | 1.220 | | 1 | 0.7 | 1.005 | 45 | 26.4 | 1.225 | | 2 | 1.4 | 1.010 | 46 | 26.9 | 1.230 | | 3 | 2.1 | 1.015 | 47 | 27.4 | 1.235 | | 4 | 2.7 | 1.020 | 48 | 27.9 | 1.240 | | 5 | 3.4 | 1.025 | 49 | 28.4 | 1.245 | | 6 | 4.1 | 1.030 | 50 | 28.8 | 1.250 | | 7 | 4.7 | 1.035 | 51 | 29.3 | 1.255 | | 8 | 5.4 | 1.040 | 52 | 29.7 | 1.260 | | 9 | 6.0 | 1.045 | 53 | 30.2 | 1.265 | | 10 | 6.7 | 1.050 | 54 | 30.6 | 1.270 | | 11 | 7.4 | 1.055 | 55 | 31.1 | 1.275 | | 12 | 8.0 | 1.060 | 56 | 31.5 | 1.280 | | 13 | 8.7 | 1.065 | 57 | 32.0 | 1.285 | | 14 | 9.4 | 1.070 | 58 | 32.4 | 1.290 | | 15 | 10.0 | 1.075 | 59 | 32.8 | 1.295 | | 16 | 10.6 | 1.080 | 60 | 33.3 | 1.300 | | 17 | 11.2 | 1.085 | 61 | 33.7 | 1.305 | | 18 | 11.9 | 1.090 | 62 | 34.2 | 1.310 | | 19 | 12.4 | 1.095 | 63 | 34.6 | 1.315 | | 20 | 13.0 | 1.100 | 64 | 35.0 | 1.320 | | 21 | 13.6 | 1.105 | 65 | 35.4 | 1.325 | | 22 | 14.2 | 1.110 | 66 | 35.8 | 1.330 | | 23 | 14.9 | 1.115 | 67 | 36.2 | 1.335 | | 24 | 15.4 | 1.120 | 68 | 36.6 | 1.340 | | 25 | 16.0 | 1.125 | 69 | 37.0 | 1.345 | | 26 | 16.5 | 1.130 | 70 | 37.4 | 1.350 | | 27 | 17.1 | 1.135 | 71 | 37.8 | 1.355 | | 28 | 17.7 | 1.140 | 72 | 38.2 | 1.360 | | 29 | 18.3 | 1.145 | 73 | 38.6 | 1.365 | | 30 | 18.8 | 1.150 | 74 | 39.0 | 1.370 | | 31 | 19.3 | 1.155 | 75 | 39.4 | 1.375 | | 32 | 19.8 | 1.160 | 76 | 39.8 | 1.380 | | 33 | 20.3 | 1.165 | 77 | 40.1 | 1.385 | | 34 | 20.9 | 1.170 | 78 | 40.5 | 1.390 | | 35 | 21.4 | 1.175 | 79 | 40.8 | 1.395 | | 36 | 22.0 | 1.180 | 80 | 41.2 | 1.400 | | 37 | 22.5 | 1.185 | 81 | 41.6 | 1.405 | | 38 | 23.0 | 1.190 | 82 | 42.0 | 1.410 | | 39 | 23.5 | 1.195 | 83 | 42.3 | 1.415 | | 40 | 24.0 | 1.200 | 84 | 42.7 | 1.420 | | 41 | 24.5 | 1.205 | 85 | 43.1 | 1.425 | | 42 | 25.0 | 1.210 | 86 | 43.4 | 1.430 | | 43 | 25.5 | 1.215 | 87 | 48.8 | 1.435 | |_____|______|__________|_____|______|__________| _______________________________________________ | | | | | | | | Tw. | B. | Density. | Tw. | B. | Density. | |_____|______|__________|_____|______|__________| | | | | | | | | 88 | 44.1 | 1.440 | 131 | 57.1 | 1.655 | | 89 | 44.4 | 1.445 | 132 | 57.4 | 1.660 | | 90 | 44.8 | 1.450 | 133 | 57.7 | 1.665 | | 91 | 45.1 | 1.455 | 134 | 57.9 | 1.670 | | 92 | 45.4 | 1.460 | 135 | 58.2 | 1.675 | | 93 | 45.8 | 1.465 | 136 | 58.4 | 1.680 | | 94 | 46.1 | 1.470 | 137 | 58.7 | 1.685 | | 95 | 46.4 | 1.475 | 138 | 58.9 | 1.690 | | 96 | 46.8 | 1.480 | 139 | 59.2 | 1.695 | | 97 | 47.1 | 1.485 | 140 | 59.5 | 1.700 | | 98 | 47.4 | 1.490 | 141 | 59.7 | 1.705 | | 99 | 47.8 | 1.495 | 142 | 60.0 | 1.710 | | 100 | 48.1 | 1.500 | 143 | 60.2 | 1.715 | | 101 | 48.4 | 1.505 | 144 | 60.4 | 1.720 | | 102 | 48.7 | 1.510 | 145 | 60.6 | 1.725 | | 103 | 49.0 | 1.515 | 146 | 60.9 | 1.730 | | 104 | 49.4 | 1.520 | 147 | 61.1 | 1.735 | | 105 | 49.7 | 1.525 | 148 | 61.4 | 1.740 | | 106 | 50.0 | 1.530 | 149 | 61.6 | 1.745 | | 107 | 50.3 | 1.535 | 150 | 61.8 | 1.750 | | 108 | 50.6 | 1.540 | 151 | 62.1 | 1.755 | | 109 | 50.9 | 1.545 | 152 | 62.3 | 1.760 | | 110 | 51.2 | 1.550 | 153 | 62.5 | 1.765 | | 111 | 51.5 | 1.555 | 154 | 62.8 | 1.770 | | 112 | 51.8 | 1.560 | 155 | 63.0 | 1.775 | | 113 | 52.1 | 1.565 | 156 | 63.2 | 1.780 | | 114 | 52.4 | 1.570 | 157 | 63.5 | 1.785 | | 115 | 52.7 | 1.575 | 158 | 63.7 | 1.790 | | 116 | 53.0 | 1.580 | 159 | 64.0 | 1.795 | | 117 | 53.3 | 1.585 | 160 | 64.2 | 1.800 | | 118 | 53.6 | 1.590 | 161 | 64.4 | 1.805 | | 119 | 53.9 | 1.595 | 162 | 64.6 | 1.810 | | 120 | 54.1 | 1.600 | 163 | 64.8 | 1.815 | | 121 | 54.4 | 1.605 | 164 | 65.0 | 1.820 | | 122 | 54.7 | 1.610 | 165 | 65.2 | 1.825 | | 123 | 55.0 | 1.615 | 166 | 65.5 | 1.830 | | 124 | 55.2 | 1.620 | 167 | 65.7 | 1.835 | | 125 | 55.5 | 1.625 | 168 | 65.9 | 1.840 | | 126 | 55.8 | 1.630 | 169 | 66.1 | 1.845 | | 127 | 56.0 | 1.635 | 170 | 66.3 | 1.850 | | 128 | 56.3 | 1.640 | 171 | 66.5 | 1.855 | | 129 | 56.6 | 1.645 | 172 | 66.7 | 1.860 | | 130 | 56.9 | 1.650 | 173 | 67.0 | 1.865 | |_____|______|__________|_____|______|__________| (From _The Oil and Colour Trades Journal_ Diary.) APPENDIX B. COMPARISON OF DIFFERENT THERMOMETRIC SCALES. _______________________________________________________________ | | | | | | | | | | Cent. | Fahr. | Cent. | Fahr. | Cent. | Fahr. | Cent. | Fahr. | |_______|_______|_______|_______|_______|_______|_______|_______| | | | | | | | | | | -40 | -40 | 2 | 35.6 | 44 | 111.2 | 86 | 186.8 | | 39 | 38.2 | 3 | 87.4 | 45 | 113 | 87 | 188.6 | | 38 | 36.4 | 4 | 39.2 | 46 | 114.8 | 88 | 190.4 | | 37 | 34.6 | 5 | 41 | 47 | 116.6 | 89 | 192.2 | | 36 | 32.8 | 6 | 42.8 | 48 | 118.4 | 90 | 194 | | 35 | 31 | 7 | 44.6 | 49 | 120.2 | 91 | 195.8 | | 34 | 29.2 | 8 | 46.4 | 50 | 122 | 92 | 197.6 | | 33 | 27.4 | 9 | 48.2 | 51 | 123.8 | 93 | 199.4 | | 32 | 25.6 | 10 | 50 | 52 | 125.6 | 94 | 201.2 | | 31 | 23.8 | 11 | 51.8 | 53 | 127.4 | 95 | 203 | | 30 | 22 | 12 | 58.6 | 54 | 129.2 | 96 | 204.8 | | 29 | 20.2 | 13 | 55.4 | 55 | 131 | 97 | 206.6 | | 28 | 18.4 | 14 | 57.2 | 56 | 132.8 | 98 | 208.4 | | 27 | 16.6 | 15 | 59 | 57 | 134.6 | 99 | 210.2 | | 26 | 14.8 | 16 | 60.8 | 58 | 136.4 | 100 | 212 | | 25 | 13 | 17 | 62.6 | 59 | 138.2 | 101 | 213.8 | | 24 | 11.2 | 18 | 64.4 | 60 | 140 | 102 | 215.6 | | 23 | 9.4 | 19 | 66.2 | 61 | 141.8 | +103 |+217.4 | | 22 | 7.6 | 20 | 68 | 62 | 143.6 | 104 | 219.2 | | 21 | 5.8 | 21 | 69.8 | 63 | 145.4 | 105 | 221 | | 20 | 4 | 22 | 71.6 | 64 | 147.2 | 106 | 222.8 | | 19 | 2.2 | 23 | 73.4 | 65 | 149 | 107 | 224.6 | | 18 | 0.4 | 24 | 75.2 | 66 | 150.8 | 108 | 226.4 | | 17 | +1.4 | 25 | 77 | 67 | 152.6 | 109 | 228.2 | | 16 | 3.2 | 26 | 78.8 | +68 |+154.4 | +110 |+230 | | 15 | 5 | 27 | 80.6 | 69 | 156.2 | 111 | 231.8 | | 14 | 6.8 | 28 | 82.4 | 70 | 158 | 112 | 283.6 | | 13 | 8.6 | 29 | 84.2 | 71 | 159.8 | 113 | 235.4 | | 12 | 10.4 | 30 | 86 | 72 | 161.6 | 114 | 237.2 | | 11 | 12.2 | 31 | 87.8 | 73 | 163.4 | 115 | 239 | | 10 | 14 | +32 | +89.6 | 74 | 165.2 | +116 |+240.8 | | 9 | 15.8 | 33 | 91.4 | 75 | 167 | 117 | 242.6 | | 8 | 17.6 | 34 | 93.2 | 76 | 168.8 | 118 | 244.4 | | 7 | 19.4 | 35 | 95 | 77 | 170.6 | 119 | 246.2 | | 6 | 21.2 | 36 | 96.8 | 78 | 172.4 | 120 | 248 | | 5 | 23 | 37 | 98.6 | 79 | 174.2 | 121 | 249.8 | | -4 | 24.8 | 49 | 100.4 | 80 | 176 | +122 |+251.6 | | 3 | 26.6 | 39 | 102.2 | 81 | 177.8 | 123 | 253.4 | | 2 | 28.4 | 40 | 104 | 82 | 179.6 | 124 | 255.2 | | 1 | 30.2 | 41 | 105.8 | 83 | 181.4 | 125 | 257 | | 0 | 32 | 42 | 107.6 | 84 | 183.2 | 126 | 258.8 | | +1 | 33.8 | 43 | 109.4 | 85 | 185 | 127 | 260.6 | |_______|_______|_______|_______|_______|_______|_______|_______| (From _Soaps_, by G. H. Hurst, published by Scott, Greenwood & Son.) APPENDIX C. TABLE OF THE SPECIFIC GRAVITIES OF SOLUTIONS OF CAUSTIC SODA. _________________________________________________________________________ | | | | | | | | Per cent. by | Lb. of actual NaOH contained | | | | weight of | in 1 gallon of lye made from | | | | | commercial caustic of | | Degrees | Specific |___________________|______________________________| | Twaddell. | gravity. | | | | | | | | | Na_{2}O. | NaOH. | 77 per | 74 per | 70 per | | | | | | cent. | cent. | cent. | |___________|__________|__________|________|_________|_________|__________| | | | | | | | | | 1 | 1.005 | 0.368 | 0.474 | 0.048 | 0.046 | 0.043 | | 2 | 1.010 | 0.742 | 0.957 | 0.097 | 0.092 | 0.087 | | 3 | 1.015 | 1.114 | 1.436 | 0.146 | 0.131 | 0.129 | | 4 | 1.020 | 1.480 | 1.909 | 0.194 | 0.185 | 0.180 | | 5 | 1.025 | 1.834 | 2.365 | 0.243 | 0.231 | 0.219 | | 6 | 1.030 | 2.194 | 2.830 | 0.291 | 0.278 | 0.262 | | 7 | 1.035 | 2.521 | 3.252 | 0.335 | 0.320 | 0.303 | | 8 | 1.040 | 2.964 | 3.746 | 0.389 | 0.371 | 0.350 | | 9 | 1.045 | 3.244 | 4.184 | 0.438 | 0.417 | 0.393 | | 10 | 1.050 | 3.590 | 4.631 | 0.486 | 0.461 | 0.438 | | 11 | 1.055 | 3.943 | 5.086 | 0.536 | 0.510 | 0.483 | | 12 | 1.060 | 4.292 | 5.536 | 0.586 | 0.558 | 0.528 | | 13 | 1.065 | 4.638 | 5.982 | 0.636 | 0.607 | 0.573 | | 14 | 1.070 | 4.972 | 6.413 | 0.680 | 0.653 | 0.617 | | 15 | 1.075 | 5.311 | 6.911 | 0.742 | 0.707 | 0.668 | | 16 | 1.080 | 5.648 | 7.285 | 0.786 | 0.749 | 0.709 | | 17 | 1.085 | 5.981 | 7.715 | 0.836 | 0.798 | 0.755 | | 18 | 1.090 | 6.311 | 8.140 | 0.886 | 0.845 | 0.800 | | 19 | 1.095 | 6.639 | 8.564 | 0.937 | 0.894 | 0.846 | | 20 | 1.100 | 6.954 | 8.970 | 0.986 | 0.941 | 0.890 | | 21 | 1.105 | 7.276 | 9.386 | 1.037 | 0.989 | 0.938 | | 22 | 1.110 | 7.594 | 9.796 | 1.087 | 1.037 | 0.981 | | 23 | 1.115 | 7.910 | 10.203 | 1.137 | 1.123 | 1.026 | | 24 | 1.120 | 8.223 | 10.607 | 1.187 | 1.175 | 1.071 | | 25 | 1.125 | 8.583 | 11.107 | 1.238 | 1.181 | 1.117 | | 26 | 1.130 | 8.893 | 11.471 | 1.296 | 1.237 | 1.170 | | 27 | 1.135 | 9.251 | 11.933 | 1.354 | 1.292 | 1.122 | | 28 | 1.140 | 9.614 | 12.401 | 1.413 | 1.350 | 1.277 | | 29 | 1.145 | 9.965 | 12.844 | 1.470 | 1.413 | 1.337 | | 30 | 1.150 | 10.313 | 13.303 | 1.529 | 1.460 | 1.381 | | 31 | 1.155 | 10.666 | 13.859 | 1.600 | 1.528 | 1.445 | | 32 | 1.160 | 11.008 | 14.190 | 1.646 | 1.541 | 1.456 | | 33 | 1.165 | 11.347 | 14.637 | 1.705 | 1.627 | 1.539 | | 34 | 1.170 | 11.691 | 15.081 | 1.764 | 1.684 | 1.593 | | 35 | 1.175 | 12.025 | 15.512 | 1.822 | 1.739 | 1.645 | | 36 | 1.180 | 12.356 | 16.139 | 1.904 | 1.817 | 1.719 | | 37 | 1.185 | 12.692 | 16.372 | 1.942 | 1.853 | 1.753 | | 38 | 1.190 | 13.016 | 16.794 | 1.998 | 1.887 | 1.804 | | 39 | 1.195 | 13.339 | 17.203 | 2.055 | 1.962 | 1.856 | | 40 | 1.200 | 13.660 | 17.629 | 2.122 | 2.026 | 1.916 | | 41 | 1.205 | 14.058 | 18.133 | 2.185 | 2.085 | 1.973 | | 42 | 1.210 | 14.438 | 18.618 | 2.252 | 2.147 | 2.033 | | 43 | 1.215 | 14.823 | 19.121 | 2.323 | 2.221 | 2.097 | | 44 | 1.220 | 15.124 | 19.613 | 2.392 | 2.280 | 2.161 | | 45 | 1.225 | 15.502 | 19.997 | 2.444 | 2.338 | 2.206 | | 46 | 1.230 | 15.959 | 20.586 | 2.562 | 2.417 | 2.285 | | 47 | 1.235 | 16.299 | 20.996 | 2.593 | 2.475 | 2.341 | | 48 | 1.240 | 16.692 | 21.532 | 2.669 | 2.548 | 2.410 | |___________|__________|__________|________|_________|_________|__________| _________________________________________________________________________ | | | | | | | | Per cent. by | Lb. of actual NaOH contained | | | | weight of | in 1 gallon of lye made from | | | | | commercial caustic of | | Degrees | Specific |___________________|______________________________| | Twaddell. | gravity. | | | | | | | | | Na_{2}O. | NaOH. | 77 per | 74 per | 70 per | | | | | | cent. | cent. | cent. | |___________|__________|__________|________|_________|_________|__________| | | | | | | | | | 49 | 1.245 | 17.060 | 22.008 | 2.739 | 2.615 | 2.474 | | 50 | 1.250 | 17.424 | 22.476 | 2.809 | 2.681 | 2.536 | | 51 | 1.255 | 17.800 | 22.962 | 2.881 | 2.750 | 2.602 | | 52 | 1.260 | 18.166 | 23.433 | 2.952 | 2.818 | 2.666 | | 53 | 1.265 | 18.529 | 23.901 | 3.020 | 2.886 | 2.730 | | 54 | 1.270 | 18.897 | 24.376 | 3.095 | 2.955 | 2.795 | | 55 | 1.275 | 19.255 | 24.858 | 3.171 | 3.027 | 2.863 | | 56 | 1.280 | 19.609 | 25.295 | 3.237 | 3.090 | 2.932 | | 57 | 1.285 | 19.961 | 25.750 | 3.308 | 3.158 | 2.988 | | 58 | 1.290 | 20.318 | 26.210 | 3.381 | 3.227 | 3.053 | | 59 | 1.295 | 20.655 | 26.658 | 3.452 | 3.364 | 3.117 | | 60 | 1.300 | 21.156 | 27.110 | 3.524 | 3.394 | 3.182 | | 61 | 1.305 | 21.405 | 27.611 | 3.603 | 3.439 | 3.253 | | 62 | 1.310 | 21.785 | 28.105 | 3.682 | 3.514 | 3.224 | | 63 | 1.315 | 22.168 | 28.595 | 3.760 | 3.593 | 3.395 | | 64 | 1.320 | 22.556 | 29.161 | 3.849 | 3.674 | 3.475 | | 65 | 1.325 | 22.926 | 29.574 | 3.919 | 3.742 | 3.539 | | 66 | 1.330 | 23.310 | 30.058 | 3.997 | 3.816 | 3.610 | | 67 | 1.335 | 23.670 | 30.535 | 4.072 | 3.891 | 3.681 | | 68 | 1.340 | 24.046 | 31.018 | 4.156 | 3.967 | 3.754 | | 69 | 1.345 | 24.410 | 31.490 | 4.232 | 4.042 | 3.824 | | 70 | 1.350 | 24.765 | 31.948 | 4.312 | 4.116 | 3.894 | | 71 | 1.355 | 25.152 | 32.446 | 4.396 | 4.196 | 3.970 | | 72 | 1.360 | 25.526 | 32.930 | 4.478 | 4.274 | 4.043 | | 73 | 1.365 | 25.901 | 33.415 | 4.561 | 4.354 | 4.109 | | 74 | 1.370 | 26.285 | 33.905 | 4.645 | 4.434 | 4.194 | | 75 | 1.375 | 26.650 | 34.382 | 4.728 | 4.513 | 4.269 | | 76 | 1.380 | 27.021 | 34.855 | 4.810 | 4.592 | 4.344 | | 77 | 1.385 | 27.385 | 35.328 | 4.893 | 4.670 | 4.418 | | 78 | 1.390 | 27.745 | 35.795 | 4.975 | 4.794 | 4.493 | | 79 | 1.395 | 28.110 | 36.258 | 5.058 | 4.828 | 4.567 | | 80 | 1.400 | 28.465 | 36.720 | 5.141 | 4.907 | 4.642 | | 81 | 1.405 | 28.836 | 37.203 | 5.227 | 4.989 | 4.720 | | 82 | 1.410 | 29.203 | 37.674 | 5.312 | 5.071 | 4.797 | | 83 | 1.415 | 29.570 | 38.146 | 5.397 | 5.135 | 4.873 | | 84 | 1.420 | 29.930 | 38.610 | 5.482 | 5.233 | 4.950 | | 85 | 1.425 | 30.285 | 39.071 | 5.567 | 5.314 | 5.027 | | 86 | 1.430 | 30.645 | 39.530 | 5.653 | 5.396 | 5.104 | | 87 | 1.435 | 30.995 | 39.986 | 5.738 | 5.467 | 5.181 | | 88 | 1.440 | 31.349 | 40.435 | 5.823 | 5.558 | 5.258 | | 89 | 1.445 | 31.700 | 40.882 | 5.908 | 5.640 | 5.335 | | 90 | 1.450 | 32.043 | 41.335 | 5.923 | 5.721 | 5.412 | | 91 | 1.455 | 32.460 | 41.875 | 6.093 | 5.816 | 5.502 | | 92 | 1.460 | 32.870 | 42.400 | 6.191 | 5.909 | 5.608 | | 93 | 1.465 | 33.283 | 42.935 | 6.290 | 6.004 | 5.679 | | 94 | 1.470 | 33.695 | 43.467 | 6.389 | 6.009 | 5.769 | | 95 | 1.475 | 34.092 | 43.980 | 6.487 | 6.193 | 5.856 | | 96 | 1.480 | 34.500 | 44.505 | 6.586 | 6.287 | 5.948 | | 97 | 1.485 | 34.899 | 45.013 | 6.685 | 6.381 | 6.035 | | 98 | 1.490 | 35.245 | 45.530 | 6.784 | 6.476 | 6.126 | | 99 | 1.495 | 35.691 | 46.041 | 6.884 | 6.571 | 6.216 | | 100 | 1.500 | 36.081 | 46.545 | 6.982 | 6.665 | 6.303 | |___________|__________|__________|________|_________|_________|__________| (From _Soaps_, by G. H. Hurst, published by Scott, Greenwood & Son.) APPENDIX D. TABLE OF STRENGTH OF CAUSTIC POTASH SOLUTIONS AT 60° F. _______________________________________________ | | | | | | Specific | Degrees | Per cent. | Lb. of KOH | | gravity. | Twaddell. | KOH. | per gal. | |__________|___________|___________|____________| | | | | | | 1.060 | 12 | 5.59 | 0.59 | | 1.110 | 22 | 11.31 | 1.25 | | 1.150 | 30 | 15.48 | 1.77 | | 1.190 | 38 | 19.29 | 2.21 | | 1.230 | 46 | 23.22 | 2.84 | | 1.280 | 56 | 27.87 | 3.56 | | 1.330 | 66 | 31.32 | 4.16 | | 1.360 | 72 | 35.01 | 4.76 | | 1.390 | 78 | 38.59 | 5.36 | | 1.420 | 84 | 40.97 | 5.81 | | 1.440 | 88 | 43.83 | 6.31 | | 1.470 | 94 | 47.16 | 6.93 | | 1.520 | 104 | 51.09 | 7.76 | | 1.600 | 112 | 55.62 | 8.89 | | 1.680 | 136 | 60.98 | 10.24 | | 1.780 | 156 | 67.65 | 12.04 | | 1.880 | 176 | 75.74 | 14.23 | | 2.000 | 200 | 86.22 | 17.24 | |__________|___________|___________|____________| (From _Soaps_, by G. H. Hurst, published by Scott, Greenwood & Son.) THE END. INDEX. A. Acetic Acid, 10 Acid, Acetic, 10 ---- Arachidic, 10 ---- Behenic, 10 ---- Butyric, 10 ---- Capric, 10 ---- Caproic, 10 ---- Caprylic, 10 ---- Carnaubic, 10 ---- Cerotic, 10 ---- Daturic, 10 ---- Doeglic, 11 ---- Elæomargaric, 12 ---- Elæostearic, 12 ---- Erucic, 11 ---- Ficocerylic, 10 ---- Hyænic, 10 ---- Hypogæic, 11 ---- Isolinolenic, 12 ---- Isovaleric, 10 ---- Jecoric, 12 ---- Lauric, 10 ---- Lignoceric, 10 ---- Linolenic, 12 ---- Linolic, 12 ---- Margaric, 10 ---- Medullic, 10 ---- Melissic, 10 ---- Moringic, 11 ---- Myristic, 10 ---- Oleic, 11 ---- Palmitic, 10 ---- Physetoleic, 11 ---- Pisangcerylic, 10 ---- Psyllostearylic, 10 ---- Rapic, 11 ---- Ricinoleic, 13 ---- Saponification, 19-21 ---- Stearic, 10 ---- Tariric, 12 ---- Telfairic, 12 ---- Theobromic, 10 ---- Tiglic, 11 ---- value, 118, 128 Acids, Classification of fatty, 10 ---- Fatty, 9-13 ---- ---- Combination with Alkali, 45, 46 Acids, Fatty, Preparation by acid process, 19-21 ---- ---- ---- by ferment process, 16 ---- ---- ---- by Twitchell's process, 20 ---- Saturated fatty, 11 ---- Unsaturated fatty, 11 Albumen in soap, 90 Alcohols, Estimation of, 128 Aldehydes, Estimation of, 129 Alkali, Caustic and carbonated, 38, 39, 123-126 Alkali in soap, Determination of, 131, 132 Amyl salicylate, 107 Andiroba oil, 32 Animal charcoal, 115 ---- fats, Treatment of, 43 Anise (star) oil, 96 Anisic aldehyde, 108 Arachidic acid, 10 Arachis oil, 28 Artificial perfumes, 107-110 Ash, Soda, 39, 124, 125 Aspic oil, 96 Aqueous saponification, 14 Aubépine, 108 B. Bacteria, Decomposition of fats by, 18 Baobab-seed oil, 36 Bar soap, 54, 55 Barring soap, 68 Bay oil, 97 Behenic acid, 10 Benzyl acetate, 108 Bergamot oil, 97 ---- ---- (artificial), 109 Biniodide soaps, 87 Birch-tar soap, 88 Bitter almond oil, 97 Bleaching palm oil, 41 ---- rosin, 43 Boiling-on-strength, 51 Bois de Rose Femelle oil, 99 Bone-fat, 30 ---- ---- treatment of, 43 Borax in soap, 88 Boric acid in soap, 88 Boric acid in soap, Determination of, 135 Borneo tallow, 32 Brine, 39 Bromine absorption of oils and fats, 122 Brown Windsor soap, 78, 98 Butter goa, 33 ---- kokum, 33 ---- shea, 31 Butyric acid, 10 Butyrin, 8 C. Calico-printer's soap, 93 Cananga oil, 98 Candle-nut oil, 33 Capric acid, 10 Caprin, 8 Caproic acid, 10 Caproin, 8 Caprylic acid, 10 Caprylin, 8 Carapa oil, 32 Caraway oil, 98 Carbolic acid in soap, Determination of, 134 Carbolic soap, 88 Carbonate potash, 39, 125, 126 ---- soda, 39, 124, 125 Carnaubic acid, 10 Cassia oil, 98 Castor oil, 30 Caustic potash, 39, 123 ---- soda, 39, 123 Cayenne linaloe oil, 99 Cedarwood oil, 98 Cerotic acid, 10 Charcoal, Animal, 115 Chinese vegetable tallow, 31 Cholesterol in unsaponified matter, 120 Cinnamon oil, 98 Citral, 108 Citronella oil, 99 Citronellal, 108 Cleansing soap, 60, 61 Close-piling soap, 71 Clove oil, 99 Coal tar soaps, 88 Cocoa-nut oil, 25, 26 Cohune-nut oil, 34 Cold process soap-making, 46, 47 Colouring soap, 66, 80, 82 Compressing soap, 83, 85 Concrete orris oil, 100 Constitution of oils and fats, 6, 7 Conversion of oleic acid into solid acids, 11, 12 Cooling soap, 74, 76 Coprah oil, 25, 26 Cotton-seed oil, 27, 42 ---- ---- Refining, 42 ---- soapstock, 40 ---- stearine, 28 Coumarin, 108 Crude glycerine, 113, 136-139 Crutching soap, 63 Curcas oil, 33 Curd mottled soap, 52, 53 Curd soaps, 52 Cutting and stamping toilet soap, 85 D. Daturic acid, 10 Decolorisation, Glycerine, 115 Decomposition of fats by bacteria, 18 Detergent action of soap, 4, 5 Diglycerides, 7 Dika fat, 36 Disinfectant soaps, 66 Distearine, 7 Distillation, glycerine, 114 Distilled glycerine, 114 Doeglic acid, 11 Double distilled glycerine, 115 Dregs in fats and oils, Determination of, 120, 121 Drying soap, 71, 78-80 Dynamite glycerine, 115 E. Elaidin reaction, 12 Electrical production of soap, 59 Elæomargaric acid, 12 Elæostearic acid, 12 Enzymes, Action of, 15-18 Erucic acid, 11 Essential oils, 96-107 ---- ---- Examination of, 127-130 Ester value, 119, 128 Ether soap, 90 Eucalyptus oil, 100 Evaporation to crude glycerine, 112, 113 F. Fat, Bone, 30 ---- Dika, 36 ---- Maripa, 34 ---- Marrow, 30 ---- Niam, 34 ---- Tangkallah, 37 ---- Treatment of bone, 43 Fats, Decomposition by bacteria of, 18 ---- Treatment of animal, 43 ---- Waste, 30 Fats and oils, Determination of acid value of, 118 ---- ---- ---- of bromine absorption of, 122 ---- ---- ---- of dregs, etc., in, 120, 121 ---- ---- ---- of free acidity of, 117 ---- ---- ---- of iodine absorption of, 121, 122 ---- ---- ---- of saponification ---- ---- ---- equivalents of, 118 ---- ---- ---- of saponification value, 118 ---- ---- ---- of specific gravity of, 117 of titre of, 122, 123 ---- ---- ---- of unsaponifiable matter in, 119 ---- ---- ---- of water in, 120 ---- ---- ---- Yield of glycerine from, 116 Fatty acids, 9-13, 31 ---- ---- Classification of, 10 ---- ---- Direct combination with alkali of, 45, 46 ---- ---- in soap, Determination of, 131 ---- ---- ---- Examination of, 133, 134 ---- ---- Preparation by acid process, 19-21 ---- ---- ---- by ferment process, 16 ---- ---- ---- by Twitchell's process, 20 ---- ---- Saturated, 11 ---- ---- Unsaturated, 11 Fennel oil, 100 Ferment process for preparation of fatty acids, 16 Ferments, action of, 15-18 Ficocerylic acid, 10 Filling soap, 65 Fish oils, 30 "Fitting," 51 Floating soap, 90, 91 Fluorides in soap, 88 Formaldehyde soap, 88 Framing soap, 66 Free alkali in soap, Estimation of, 132 ---- caustic in soap, Neutralising, 66 ---- fat in soap, Determination of, 133 ---- fatty acids, Determination of, 117 G. Geraniol, 108 Geranium oils, 101 Geranium-sur-rose oil, 101 Ginger-grass oil, 101 Glycerides, 7, 8 Glycerine, Chemically pure, 115 ---- Crude, 113, 136-139 ---- decolorisation, 115 ---- distillation, 114 ---- Distilled, 114 ---- dynamite, 115 ---- in soap, Determination of, 134, 135 ---- manufacture, 111-114 ---- saponification, 116 ---- soaps, 89 ---- Yield of, from fats and oils, 116 Glycerol determination, acetin method, 136 ---- ---- bichromate method, 137, 138 ---- in lyes, Estimation of, 135 Goa-butter, 33 "Graining-out," 50 Grease, Animal, 30 ---- Bone, 30 ---- Kitchen, 30 ---- Skin, 30 Guaiac wood oil, 101 H. Halphen's reaction, 134 Heliotropin, 108 Hemp-seed oil, 29 Hyacinth, 108 Hyænic acid, 10 Hydrated soaps, 48, 49 Hydrolysis accelerated by heat and electricity, 14, 15 ---- accelerated by use of chemical reagents, 19-23 ---- accelerated with acid, 19, 21 ---- Enzymic, 15-18 ---- of oils and fats, 13-23 ---- of soap, 3 Hypogæic acid, 11 I. Ichthyol soap, 89 Inoy-kernel oil, 37 Iodine absorption of rose oil, 130 ---- absorption of oils and fats, 121,122: ---- soap, 89 Ionone, 108 Isolinolenic acid, 12 Isovaleric acid, 10 Isovalerin, 8 J. Jasmine, 109 Jecoric acid, 12 K. Kananga oil, 98 Kapok oil, 32 "Kastilis," 88 Kokum butter, 33 L. Lard, 25 Lauric acid, 10 Laurin, 8 Lavender oils, 101 Lemon-grass oil, 102 Lemon oil, 102 Lignoceric acid, 10 Lime oil, 102 ---- saponification, 22 Linaloe oil, 102 Linalol, 109 Linalyl acetate, 109 Linolenic acid, 12 Linolic acid, 12 Linseed oil, 29 Lipase, 18 Liquoring of soaps, 64 Lyes, analysis of, 135 ---- Determination of glycerol in, 135 ---- Evaporation of, 112 ---- Treatment of, 111, 112 Lysol soap, 89 M. Mafura tallow, 35 Magnesia, Hydrolysis by, 22 Maize oil, 28 Margaric acid, 10 Margosa oil, 35 Marine animal oils, 30 ---- soap, 49 Maripa fat, 34 Marjoram oil, 103 Medicated soaps, 86-90 Medullic acid, 10 Melissic acid, 10 Melting point, 130 Mercury soaps, 87 Milled toilet soaps, 78 Milling soap, 80, 81 ---- soap-base, 54, 78 Mineral oil, saponifying, 58, 59 Mirbane oil or nitrobenzene, 109 Mixed glycerides, 8 Monoglycerides, 7 Monostearin, 7 Moringic acid, 11 Mottled soaps, 52, 53 ---- ---- Pickling, 54 Moulds, Soap, 72, 85, 86 Mowrah-seed oil, 31 Musk (artificial), 109 Myristic acid, 8 Myristin, 8 N. Naphthol soap, 89 Neroli Bigarade oil, 103 ---- oil (artificial), 109 Neutralising free caustic in soap, 66, 80 Niam fat, 34 Nigre, 56 Nigres, Utilisation of, 56 Niobe oil or ethyl benzoate, 110 Nitrobenzene, 109 O. Oeillet, 10 Oil, Andiroba, 32 ---- Arachis, 28 ---- Aspic (lavender spike), 96 ---- Baobab-seed, 36 ---- Bay, 97 ---- Bergamot, 97 ---- Bitter almond, 97 ---- Bleaching palm, 41 ---- Bois de Rose Femelle, 99 ---- Cananga, 98 ---- Candle-nut, 33 ---- Carapa, 32 ---- Caraway, 98 ---- Cassia, 98 ---- Castor, 30 ---- Cayenne linaloe, 99 ---- Cedarwood, 98 ---- Cinnamon, 98 ---- Citronella, 99 ---- Clove, 99 ---- Cocoa-nut, 25, 26 ---- Cohune-nut, 34, 35 ---- Concrete orris, 100 ---- Coprah, 25, 26 ---- Cotton-seed, 27, 42 ---- Curcas, 33 ---- Eucalyptus, 100 ---- Fennel, 100 ---- Geranium, 101 ---- Ginger-grass, 101 ---- Guaiac-wood, 101 ---- Hemp-seed, 29 ---- Inoy-kernel, 37 ---- Kananga, 98 ---- Kapok, 32 ---- Lemon, 102 ---- Lemon-grass, 102 ---- Lime, 102 ---- Linaloe, 102 ---- Linseed, 29 ---- Maize, 28 ---- Margosa, 35 ---- Marjoram, 103 ---- Mowrah-seed, 31 ---- Neroli Bigarade, 103 ---- Olive, 26 ---- Olive-kernel, 27 ---- Orange, 163 ---- Palm, 27, 41 ---- Palm-nut, 26 ---- Palmarosa, 103 ---- Patchouli, 103 ---- Peppermint, 103, 104 ---- Persimmon-seed, 36 ---- Peru-balsam, 104 ---- Petit-grain, 104 ---- Pongam, 35 ---- Refining cotton-seed, 42 ---- Rose, 105 ---- Rosemary, 105 ---- Safflower, 33, 34 ---- Sandalwood, 105, 106 ---- Saponifying mineral, 58, 59 ---- Sassafras, 106 ---- Sesame, 28, 29 ---- Star-anise, 96 ---- Sunflower, 29 ---- Thyme, 106 ---- Verbena, 106 ---- Vetivert, 106-107 ---- Wheat, 36 ---- Wild mango, 36 ---- Wintergreen, 107 ---- Ylang-ylang, 107 Oils and fats, Constitution of, 6, 7 ---- ---- Examination of, 117-123 ---- ---- Hydrolysis of, 13-22 ---- Fish and marine animal, 30 ---- Lavender, 101 ---- Refractive Index of, 122 ---- treatment of vegetable, 43 Oleic acid, 11 ---- ---- into solid acids, Conversion of, 11, 12 Olein, 8, 9, 31 ---- Cocoa-nut, 31 ---- Palm-nut, 31 Oleodidaturin, 8 Oleodipalmitin, 8 Oleodistearin, 8 Oleopaimitostearin, 8 Olive-kernel oil, 27 Olive oil, 26 Open-piling soap, 71 Optical rotation, 127 Orange oil, 103 Orchidée, 107 Orris oil, concrete, 100 P. Palm oil, 27, 41 ---- ---- Bleaching, 41 Palmarosa oil, 103 Palmitic acid, 10 Palmitin, 8 Palmitodistearin, 8 Palm-nut oil, 26 Pasting or saponification, 49 Patchouli oil, 103 Patent textile soaps, 94 Pearl-ash, Analysis of, 125, 126 Peppermint oil, 103, 104 Perfumer's soaps, 77, 78 Perfumes, Artificial and synthetic, 107-110 ---- Soap, 95-110 Perfuming soaps, 94 Persimmon seed oil, 36 Peru-balsam oil, 104 Petit-grain oil, 104 Phenols, Determination of, 129 Physetoleic acid, 11 Phytosterol in unsaponifiable matter, 120 Pickling mottled soap, 54 Pisangcerylic acid, 10 Polishing soaps, 94 Pongam oil, 35 Potash, Carbonate, 39, 125, 126 ---- Caustic, 89, 123 Potassium chloride, 126 ---- Determination of, 126, 132 Powders, Soap, 94 Psyllostearylic acid, 10 R. Rancidity, 18, 24 Rapic acid, 11 Refining cotton-seed oil, 42 Refractive index of oils and fats, 122 Remelted soaps, 77, 78 Resinate of soda, 43, 44 Ricinoleic acid, 13 Ricinolein, 8 Rose oil, 105 ---- ---- (artificial), 110 Rosemary oil, 105 Rosin, 37, 38, 43, 44, 55 ---- Bleaching, 43 ---- Determination of, 133, 134 ---- treatment, 43, 44 S. Safflower oil, 33, 34 Safrol, 110 Salt, 39, 126 ---- Determination of, 124, 125, 126, 132 Sandalwood oil, 105, 106 Santalol, 110 Saponification, 13-22, 49 ---- accelerated by heat and electricity, 14, 15 ---- accelerated by use of chemical reagents, 19, 23 ---- accelerated with Twitchell's reagent, 20 ---- Acid, 19, 21 ---- Aqueous, 14 ---- by ferment process, 20 ---- equivalent, 118 ---- Glycerine, 116 ---- Lime, 22 ---- under pressure, 47 ---- value, 118, 128 Saponifying mineral oil, 58, 59 Sassafras oil, 106 Saturated acids, 11 Scouring soaps, 92, 93 Sesame oil, 28, 29 Settled soap, Treatment of, 60-76 Shaving soaps, 91 Shea butter, 31 Silicate of soda in soap, 65 Silicates of soda and potash, 127, 138 Silk scouring soaps, 93 ---- dyer's soap, 93, 94 Slabbing soap, 68 Soap, Albumen in, 90 ---- Analysis of, 130-35 ---- Bar, 54, 55 ---- Barring, 68 ---- -base, Milling, 54, 78 ---- Biniodide, 87 ---- Birch-tar, 88 ---- Borax, 88 ---- Boric acid in, 88 ---- ---- ---- ---- Determination, 135 ---- Carbolic, 88 ---- Classification of, 45 ---- Cleansing, 60, 61 ---- Coal-tar, 88 ---- Cold process, 46, 47 ---- Compressing, 83, 85 ---- Cooling, 74-76 ---- Crutching, 63 ---- Curd, 52 ---- Curd mottled, 53 ---- Definition of, 1, 2 ---- Detergent action of, 4, 5 ---- Determination of carbolic acid in, 134 ---- ---- of fatty acids in, 131 ---- ---- of free alkali in, 132 ---- ---- of free fat in, 133 ---- ---- of glycerine in, 134, 135 ---- ---- of total alkali in, 131 ---- ---- of water in, 133 ---- Drying, 71, 78-80 ---- Electrical production of, 59 ---- Ether, 90 ---- Examination of fatty acids 133, 134 ---- Filling, 65 ---- Fluorides in, 90 ---- formaldehyde, 88 ---- frame, 66 ---- framing, 66 ---- from fatty acids, 45, 46 ---- Glycerine, 89 ---- Hydrated, 48, 49 ---- Hydrolysis of, 3 ---- Ichthyol, 89 ---- Iodine, 89 ---- Lysol, 89 ---- Marine, 49 ---- Milling, 80, 81 ---- Monopole, 94 ---- Mottled, 52, 53 ---- moulds, 72, 85, 86 ---- Naphthol, 89 ---- Neutralising, colouring and perfuming, 66, 80, 82 ---- Open and close piling, 71 ---- perfumes, 95-110 ---- Pickling mottled, 54 ---- powders, 94 ---- Properties of, 2 ---- Salicylic acid, 88 ---- Settling of, 55 ---- Slabbing, 68 ---- Soft, 41 ---- Stamping, 71, 72, 85, 86 ---- Sulphur, 89 ---- Terebene, 90 ---- Thymol, 90 ---- Transparent, 57, 58 ---- Treatment of settled, 60-76 ---- Yellow household, 54, 55 Soap-making, 45-59 ---- ---- Blue and grey mottled, 53 ---- ---- "Boiling-on-strength," 51 ---- ---- Cold process, 46, 47 ---- ---- Combination of fatty acids with alkali, 45, 46 ---- ---- Curd, 52 ---- ---- Curd, Mottled, 53 ---- ---- "Fitting," 51 ---- ---- "Graining-out" or separation, 50 ---- ---- Hydrated, 49 ---- ---- "Pasting" or saponification, 49 ---- ---- Soft, 48 ---- ---- Transparent, 57, 58 ---- ---- under pressure, 47 Soaps, Calico-printer's, 93 ---- Disinfectant, 66 ---- Floating, 90, 91 ---- Liquoring of, 64, 65 ---- Medicated, 86-90 ---- Milled toilet, 78 ---- Miscellaneous, 94 ---- Perfumer's, 77, 78 ---- Polishing, 94 ---- Remelted, 77, 78 ---- Scouring, 92 ---- Shaving, 91 ---- Silicating, 65 ---- Silk dyer's, 93, 94 ---- Textile, 91-94 ---- Toilet, 77, 78 ---- Woollen dyer's, 92 Soap-stock, 40 Soda ash, 39, 124, 125 ---- ---- Caustic, 39, 125 ---- Carbonate, 39, 124, 125 ---- Caustic, 39, 123 ---- Resinate, 43, 44 Soft soap-making, 48 Solidifying-point, 130 Specific gravity, Determination of, 117, 127 Stamping soap, 71, 72, 85, 86 Starch, Detection of, 121, 135 Steapsin, 18 Stearic acid, 10 Stearin, 8, 9 Stearine, Cotton-seed, 28 Stearodipalmitin, 8 Sulphides and sulphites, Determination of, 125 Sulphur soap, 89 Sunflower oil, 29 Superfatting material, 83 Synthetic perfumes, 107-110 T. Table of caustic potash solutions, 151 ---- of caustic soda solutions, 149, 150 ---- of comparative densities, 147 ---- of thermometric equivalents, 148 Tablet soap, 55 Talc, 65 Tallow, 24 ---- Borneo, 32 ---- Chinese vegetable, 31 ---- Mafura, 35 Tangkallah fat, 37 Tariric acid, 12 Telfairic acid, 12 Terebene, 110 ---- soap, 90 Terpineol, 110 Textile soaps, 91-94 ---- ---- Patent, 94 Theobromic acid, 10 Thyme oil, 106 Thymol soap, 90 Tiglic acid, 11 Titre test, 122, 123 Toilet soaps, 77, 78 ---- ---- Compressing, 83, 85 ---- ---- Milled, 78 ---- ---- Milling, 80, 81 ---- ---- Stamping, 85, 86 Transparent soaps, 57, 58 Treatment of animal fats, 43 ---- ---- bone fat, 43 ---- ---- lyes, 111, 112 ---- ---- rosin, 43 ---- ---- settled soap, 60-76 ---- ---- Vegetable oils, 43 Trèfle, 107 Triglycerides, 7, 8 Trilaurin, 9 Triolein, 9 Tripalmitin, 9 Tristearin, 7, 9 Twitchell's process, 22 U. Unsaponifiable matter, Constitution of, 119, 120 ---- ---- Determination of, 119 Unsaturated acids, 11 Utilisation of nigres, 56 V. Vanillin, 110 Vegetable oils, Treatment of, 43 ---- tallow, Chinese, 31 Verbena oil, 106 Vetivert oil, 106 Violet soap, 54 Volhard's method for chloride determination, 132 W. Waste fats, 30 Water, 39 ---- ---- in fats, Determination of, 120 ---- ---- in soap, Determination of, 133 Wheat oil, 36 Wild mango oil, 36 Wintergreen oil, 107 Wool scouring soaps, 92 Woollen dyer's soap, 92 Y. Ylang-ylang oil, 107 Z. Zinc oxide, Hydrolysis by, 22 ---- soap, 87 THE ABERDEEN UNIVERSITY PRESS LIMITED STEVENSON & HOWELL'S SPECIALITIES FOR Soapmakers & Wholesale Perfumers. ESSENTIAL OILS OF GUARANTEED PURITY. Almonds, Bay Leaves, Bergamot, Caraway, Cananga, Camomile, Cascarilla, Cassia, Cedar Wood, Cinnamon, Citronella, Cloves, Coriander, Eucalyptus Globulus, Fennel, Sweet, Geranium -- _Algerian_, _Bourbon_, _East Indian_, _French_, _Spanish_ & _Turkish_, Kuromoji, Lavender, Lemon, Lemon-Grass, Limes, Neroli, Myrbane, Orange Sweet & Bitter, Otto of Rose, Patchouli, Palmarosa, Pimento, Petit-Grain, Rosemary, Sandal Wood, Sage, Sassafras, Spearmint, Thyme, Wintergreen Ylang-Ylang., &c. TOILET SOAP PERFUMES FINEST QUALITY Almond, Bay Rum, Brown Windsor, Cologne, Florida, Frangipanni, Heliotrope, Hyacinth, Lilac, Lily of Valley, Oriental, Parisian, Walnut Leaf, Wood Violet, &c. ARTIFICIAL PERFUMES. Aubepine, Cuir de Russiè, Coumarin, Crategine, Heliotropine, Lilac, Musk, Nerolin, Terpineol, Vanillin, Yara-Yara, &c. SOAP COLOURS, Dark Blue, Rose Pink, Indian Brown, Carbolic Pink & Red, Manchester Yellow. &c. &c. _SPECIALITY_:--RELIABLE CHLORPHYL. STANDARD WORKS SOUTHWARK ST. LONDON. S. E. GLASGOW OFFICE 128, HOPE ST. ___________________________________________________ | | | FASTEST AND STRONGEST | | | | COLOURS FOR SOAP | | | | In all shades, alkali-proof. | | | | OIL SOLUBLE COLOURS FOR | | OIL AND BENZINE SOAPS. | | | | BLACKS | | | | And all colours soluble in Oil, Wax and Turps for | | | | BOOT POLISH. | | | | =============================================== | | | | WILLIAMS BROS. & CO., HOUNSLOW. | |___________________________________________________| TEXTILE SOAPS AND OILS. Handbook on the Preparation, Properties and Analysis of the Soaps and Oils used in Textile Manufacturing, Dyeing and Printing. BY GEORGE H. HURST, F.C.S., Author of "Soaps," "Lubricating Oils, Fats and Greases," etc. CONTENTS. Methods of Making Soaps--Special Textile Soaps--Relation of Soap to Water for Industrial Purposes--Soap Analysis--Fat in Soap--Animal and Vegetable Oils and Fats--Vegetable Soap, Oils and Fats--Glycerine--Textile Oils. Price 5s. net (Post Free, 5s. 4d. Home; 5s. 6d. Abroad). Published by SCOTT, GREENWOOD & SON, 8 BROADWAY, LUDGATE HILL, LONDON, E.C. WILLIAM TULLOCH & CO., 30 George Square, Glasgow, And at 9 Great Tower Street, London, E.C., 14 No. Corridor, Royal Exchange, Manchester. GLYCERINE, CRUDE, DYNAMITE, INDUSTRIAL, CHEMICALLY PURE. All Kinds of Chemicals for Soap and Explosives Makers. NITRATE OF LEAD, FARINAS, STARCHES, GUMS. TWITCHELL PROCESS OF GLYCERINE EXTRACTION. HIGHEST Degree of Decomposition. LOWEST Cost for Installation and Working. BEST Qualities of Fatty Acids, Glycerine, Stearine and Soap. For Samples and information, apply to WM. TULLOCH & CO., 30 GEORGE SQUARE, GLASGOW. General Representatives for United Kingdom and Colonies. SUDFELDT & CO., MELLE (HANOVER, GERMANY). JOSLIN SCHMIDT & CO., CINCINNATI, OHIO, U.S.A. THE CHEMISTRY OF Essential Oils AND Artificial Perfumes. BY ERNEST J. PARRY, B.Sc. (Lond.), F.I.C., F.C.S. 552 Pages. Second Edition, Revised and Enlarged. Demy 8vo. 1908. CONTENTS. Chapters I. ~The General Properties of Essential Oils.~ Physical Properties, Optical Properties, Table of Specific Gravities, Refractive Indices and Rotation.--II. ~Compounds occurring in Essential Oils.~ (I.) 1. TERPENES--Pinene, Camphene, Limonene, Dipentene, Fenchene, Sylvestrene, Carvestrene, Phellandrene, Terpinolene, Terpinene and Thujene. 2. SESQUITERPENES--Cadinene, Caryophellene, Cedrene, Clovene, Humulene, Ledene, Patchoulene, and Sesquiterpene from Oils of Cannabis Indica, Table, b.p., sp.-gr., opt. Rot., etc., of same. (II.) THE CAMPHOR SERIES--Borneol, Isoborneol, Camphor, Fenchyl Alcohol, Fenchone, Thujyl Alcohol, Thujone, Terpineol, Cineol, etc., etc. (III.) THE GERANIOL AND CITRONELLOL GROUP--Coriandrol, Nerolol, Rhodinol, Geraniol, Linalol, Citrenellol, etc., Table, b.p., sp.-gr., Ref. Index, etc. (IV.) BENZENE COMPOUNDS--Cymene, Phenols and their Derivatives, Phenols with Nine Carbon Atoms, Phenols with Ten Carbon Atoms, Alcohols, Aldehydes, Ketones, Acids, etc. (V.) ALIPHATIC COMPOUNDS--Alcohols, Acids, Aldehydes, Sulphur Compounds, etc.--III. ~The Preparation of Essential Oils.~ Expression, Distillation, Extraction, Table of Percentages.--IV. ~The Analysis of Essential Oils.~ Specific Gravity, Sprengel Tube Method, Optical Methods, Melting and Solidifying Points, Boiling Point and Distillation, Quantitative Estimations of Constituents, the Determination of Free Alcohols, Absorption Processes.--V. ~Systematic Study of the Essential Oils.~ Oils of the Gymnosperms, Tabulated Angiosperms. (I.) WOOD OILS.--Cedar Oils, Oils of Turpentine, American Turpentine, French Oil of Turpentine, German, Russian, and Swedish ditto, Table of Activities of same, Juniper Wood Oil. (II.) FRUIT OILS.--Juniper Berry Oil, Fir Cone Oils. (III.) LEAF OILS.--Thuja Oil, Oil of Savin, Cedar Leaf Oil, Pine Needle Oil, Cypress Leaf Oil, Table of Pine Oils (after Schimmel). OILS OF THE ANGIOSPERMS--(I.) MONOCOTYLEDONS. (II.) DICOTYLEDONS: (_a_) MONOCHLAMYDEÆ--(_b_) GAMOPETALÆ--(_c_) POLYPETALÆ--VI. ~Terpeneless Oils.~ Terpeneless Oil of Lemon, Tables of sp.-gr. and Rotn. of several Terpeneless Oils, Terpeneless Oil of Orange, Ditto of Caraway, of Lavender, Table of sp.-gr. and Rotn. of Commercial Samples of Oils.--VII. ~The Chemistry of Artificial Perfumes.~ Vanillin, Coumarin, Heliotropin, Aubepine or Hawthorn, Ionone, Specification of Patents for Preparation of Ionone, for Artificial Violet Oil, Artificial Musk, Specification of Patent of Musk Substitute, Artificial Neroli, Artificial Lilac, Artificial Hyacinth, Artificial Lemon Oil, Artificial Rose Oil, Niobe Oil, Bergamiol, Artificial Jasmin Oil, Artificial Cognac Oil.--~Appendix.~ Table on Constants of the more Important Essential Oils.--~Index.~ Price 12s. 6d. net (Post Free, 13s. Home; 13s. 6d. Abroad). PUBLISHED BY ~SCOTT, GREENWOOD & SON,~ ~8 BROADWAY, LUDGATE HILL, LONDON E.C.~ 
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20917	----	produced from images produced by Core Historical Literature in Agriculture (CHLA), Cornell University) THE CULTIVATION OF THE NATIVE GRAPE, AND MANUFACTURE OF AMERICAN WINES. By GEORGE HUSMANN, OF HERMANN, MISSOURI. GEO. E. WOODWARD, PUBLISHER AND IMPORTER, Art, Architectural and Rural Books, 136 CHAMBERS STREET, NEW YORK. ORANGE JUDD CO., 245 Broadway. Entered according to Act of Congress, in the year 1866, by GEO. E. & F. W. WOODWARD, In the Clerk's Office of the District Court of the United States, for the Southern District of New York. TO THE GRAPE GROWERS OF "OUR COUNTRY, ONE AND INDIVISIBLE," THIS VOLUME IS DEDICATED BY THEIR FRIEND AND FELLOW-LABORER, THE AUTHOR. INDEX. PAGE. INTRODUCTION 9 GRAPE CULTURE. Remarks on its History in America, especially at the West; its Progress and its Future, 13 PROPAGATION OF THE VINE. I.--From Seed 27 II.--By Single Eyes 30 The Propagating House 31 Mode of Operating 32 III.--By Cuttings in Open Air 37 IV.--By Layering 39 V.--By Grafting 40 THE VINEYARD. Location and Soil 43 Preparing the Soil 45 WHAT SHALL WE PLANT? Choice of Varieties 47 The Concord 48 Norton's Virginia 48 Herbemont 49 Delaware 49 Hartford Prolific 49 Clinton 50 PLANTING. Planting. 51 Treatment of the Vine the First Summer 56 Treatment of the Vine the Second Summer 57 Treatment of the Vine the Third Summer 63 Treatment of the Vine the Fourth Summer 69 Training the Vines on Arbors and Walls 71 Other Methods of Training the Vine 75 Diseases of the Vine 78 Insects Injurious to the Grape 80 Birds 84 Frosts 85 Girdling the Vine to Hasten Maturity 86 Manuring the Vine 91 Thinning of the Fruit 91 Renewing Old Vines 92 Pruning Saws 93 Preserving the Fruit 95 Gathering the Fruit to Make Wine 96 VARIETIES OF GRAPES. CLASS I.--VARIETIES MOST GENERALLY USED. Concord (Description) 97 Concord (Plate) 111 Norton's Virginia (Description) 98 Norton's Virginia (Plate) 87 Herbemont (Plate) 99 Herbemont (Description) 101 Hartford Prolific (Description) 101 Hartford Prolific (Plate) 105 Clinton 102 Delaware (Description) 102 Delaware (Plate) 81 CLASS II.--HEALTHY VARIETIES PROMISING WELL. Cynthiana 103 Arkansas 104 Taylor 104 Martha 107 Maxatawney (Description) 107 Maxatawney (Plate) 177 Rogers' Hybrid, No. 1 107 Creveling (Description) 108 Creveling (Plate) 117 North Carolina Seedling 108 Cunningham 109 Rulander 109 Louisiana 110 Alvey 110 Cassady 110 Blood's Black 113 Union Village (Description) 113 Union Village (Plate) 167 Perkins 113 Clara (Description) 114 Clara (Plate) 127 Ive's Seedling 114 CLASS III.--HEALTHY VARIETIES--BUT INFERIOR IN QUALITY. Minor Seedling 116 Mary Ann 119 Northern Muscadine 119 Logan 119 Brown 119 Hyde's Eliza 119 Marion Port 120 Poeschel's Mammoth 120 Cape 120 Dracut Amber 120 Elsinburgh 120 Garber's Albino 121 Franklin 121 Lenoir 121 North America 121 CLASS IV.--VARIETIES OF GOOD QUALITY, BUT SUBJECT TO DISEASE. Catawba 121 Diana 122 Isabella 122 Garrigues 123 Tokalon 123 Anna 123 Allen's Hybrid 123 Cuyahoga 123 Devereux 124 Kingsessing 124 Rogers' Hybrid, No. 15 124 CLASS V.--VARIETIES UNWORTHY OF CULTIVATION. Oporto 124 Massachusetts White 125 WINE MAKING. Gathering the Grapes 131 The Wine Cellar 133 Apparatus for Wine Making.--The Grape Mill and Press 136 Fermenting Vats 137 The Wine Casks 138 Making the Wine 140 After Treatment of the Wine 146 Diseases of the Wine and their Remedies 147 Treatment of flat and Turbid Wine 147 Use of the Husks and Lees 148 Dr. Gall's and Petoil's Method of Wine Making 148 The Must Scale or Saccharometer 150 The Acidimeter and Its Use 151 The Change of the Must, by Fermentation, into Wine 157 Normal Must 161 The Must of American Grapes 162 Wine Making Made Easy 173 STATISTICS. Cost of Establishing A Vineyard 179 Cost of an acre of Concord 179 Cost of an acre of Herbemont 179 Cost of an acre of Norton's Virginia 180 Cost of an acre of Delaware 180 Cost of an acre of Catawba 180 Product 181 Produce Fifth Year 182 Yield of Mr. MICHAEL POESCHEL'S Vineyard 184 New Vineyard of Mr. M. POESCHEL, Planted in 1861; First Partial Crop, 1863; Second Crop, 1864; Third Crop, 1865, 184, 185 Yield of Vineyard of Mr. WILLIAM POESCHEL, 1857, 1858, 1859, 1860 185 Yield of Vineyard of Mr. WILLIAM POESCHEL 1861, 1862, 1863, 1864 186 Yield of Vineyard of Mr. WILLIAM POESCHEL 1865 187 Yield of Delaware Vineyard of JOHN E. MOTTIER 189 INTRODUCTION It is with a great deal of hesitation I undertake to write a book about Grapes, a subject which has been, and still is, elucidated every day; and about which we have already several works, which no doubt are more learned, more elaborate, than anything I may produce. But the subject is of such vast importance, and the area suitable for grape culture so large, the diversity of soil and climate so great, that I may be pardoned if I still think that I could be of some use to the beginner; it is for them, and not for my brethren of the craft more learned than I am, that I write. If they can learn anything from the plain talk of a practical worker, to help them along in the good work, I am well repaid. Another object I have in view is to make grape growing as easy as possible; and I may be pardoned if I say that, in my opinion, it is a defect in all books we have on grape culture, that the manner of preparing the soil, training, etc., are on too costly a plan to be followed by men of little means. If we are first to trench and prepare the soil, at a cost of about $300 per acre, and then pay $200 more for trellis, labor, etc., the poor man, he who must work for a living, can not afford to raise grapes. And yet it is from the ranks of these sturdy sons of toil that I would gain my recruits for that peaceful army whose sword is the pruning-hook; it is from their honest, hard-working hands I expect the grandest results. He who has already wealth enough at command can of course afford to raise grapes with bone-dust, ashes, and all the fertilizers. He can walk around and give his orders, making grape culture an elegant pastime for his leisure hours, as well as a source of profit. But, being one of the first class myself, I had to fight my way up through untold difficulties from the lowest round of the ladder; had to gain what knowledge I possess from dear experience, and can therefore sympathize with those who must commence without means. It is my earnest desire to save _them_ some of the losses which _I_ had to suffer, to lighten their toil by a little plain advice. If I can succeed in this, my object is accomplished. In nearly all our books on grape culture I notice another defect, especially in those published in the East; it is, that they contain a great deal of good advice about grape culture, but very little about wine-making, and the treatment of wine in the cellar. For us here at the West this is an all-important point, and even our Eastern friends, if they continue to plant grapes at the rate they have done for the last few years, will soon glut the market, and will be forced to make them into wine. I shall therefore try to give such simple instructions about wine-making and its management as will enable every one to make a good saleable and drinkable wine, better than nine-tenths of the foreign wines, which are now sold at two to three dollars per bottle. I firmly believe that this continent is destined to be the greatest wine-producing country in the world; and that the time is not far distant when wine, the most wholesome and purest of all stimulating drinks, will be within the reach of the common laborer, and take the place of the noxious and poisonous liquors which are now the curse of so many of our laboring men, and have blighted the happiness of so many homes. Pure light wine I consider the best temperance agent; but as long as bad whisky and brandy continue to be the common drink of its citizens we can not hope to accomplish a thorough reform; for human nature seems to crave and need a stimulant. Let us then try to supply the most innocent and healthy one, the exhilarating juice of the grape. I have also endeavored throughout to give plain facts, to substantiate with plain figures all I assert; and in no case have I allowed fancy to roam in idle speculations which cannot be demonstrated in practice. I do not pretend that my effort is "the most comprehensive and practical essay on the grape," as some of our friends call their productions, but I can claim for it strict adherence to truth and actual results. I have not thought it necessary to give the botanical description of the grape-vine, and the process of hybridizing, etc.; this has already been so well and thoroughly done by my friend FULLER, that I can do no better than refer the scientific reader to his book. I am writing more for the practical farmer, and would rather fill what I think a vacancy, than repeat what has been so well said by others. With these few remarks, which I thought due to the public and myself, I leave it to you, brother-winegrowers, to say whether or not I have accomplished my task. To all and every one who plants a single vine I would extend the hand of good fellowship, for he is a laborer in the great work to cover this glorious land of the free with smiling vineyards, and to make its barren spots flow with noble grape juice, one of the best gifts of an all-bountiful Creator. All hail to you, I greet you from _Free_ Missouri. GRAPE CULTURE REMARKS ON ITS HISTORY IN AMERICA, ESPECIALLY AT THE WEST--ITS PROGRESS AND ITS FUTURE. In an old chronicle, entitled, "The Discovery of America in the Tenth Century," by CHARLES C. PRASTA, published at Stralsund, we find the following legend: "LEIF, son of ERIC the Red, bought BYARNES' vessel, and manned it with thirty-five men, among whom was also a German, TYRKER by name, who had lived a long time with LEIF'S father, who had become very much attached to him in youth. And they left port at Iceland, in the year of our Lord 1000. But, when they had been at sea several days, a tremendous storm arose, whose wild fury made the waves swell mountain high, and threatened to destroy the frail vessel. And the storm continued for several days, and increased in fury, so that even the stoutest heart quaked with fear; they believed that their hour had come, and drifted along at the mercy of wind and waves. Only LEIF, who had lately been converted to CHRIST our Lord, stood calmly at the helm and did not fear; but called on Him who had walked the water and quieted the billows, with firm faith, that He also had power to deliver them, if they but trusted in Him. And, behold! while he still spoke to them of the wonderful deeds of the Lord, the clouds cleared away, the storm lulled; and after a few hours the sea, calmed down, and rocked the tired and exhausted men into a deep and calm sleep. And when they awoke, the next morning, they could hardly trust their eyes. A beautiful country lay before them, green hills, covered with beautiful forests--a majestic stream rolled its billows into the ocean; and they cast the anchor, and thanked the Lord, who had delivered them from death. A delightful country it seemed, full of game, and birds of beautiful plumage; and when they went ashore, they could not resist the temptation to explore it. When they returned, after several hours, TYRKER alone was missing. After waiting some time for his return, LEIF, with twelve of his men, went in search of him. But they had not gone far, when they met him, laden down with grapes. Upon their enquiry, where he had stayed so long, he answered: "I did not go far, when I found the trees all covered with grapes; and as I was born in a country, whose hills are covered with vineyards, it seemed so much like home to me, that I stayed a while and gathered them." They had now a twofold occupation, to cut timber, and gather grapes; with the latter, they loaded the boat. And Leif gave a name to the country, and called it Vinland, or Wineland." So far the tradition. It is said that coming events cast their shadows before them. If this is so, may we not recognize one of those shadows in the old Norman legend of events which transpired more than eight hundred years ago? Is it not the foreshadowing of the destiny of this great continent, to become, in truth and verity, a _Wineland_. Truly, the results of to-day would certainly justify us in the assertion, that there is as much, nay more, truth than fiction in it. Let us take a glance at the first commencement of grape culture, and see what has been the progress in this comparatively new branch of horticulture. From the very first settlement of America, the vine seems to have attracted the attention of the colonists, and it is said that as early as 1564, wine was made from the native grape in Florida. The earliest attempt to establish a vineyard in the British North American Colonies was by the London Company in Virginia, about the year 1620; and by 1630, the prospect seems to have been encouraging enough to warrant the importation of several French vine-dressers, who, it is said, ruined the vines by bad treatment. Wine was also made in Virginia in 1647, and in 1651 premiums were offered for its production. BEVERLY even mentions, that prior to 1722, there were vineyards in that colony, producing seven hundred and fifty gallons per year. In 1664, Colonel RICHARD NICOLL, Governor of New York, granted to PAUL RICHARDS, a privilege of making and selling wine free of all duty, he having been the first to enter upon the cultivation of the vine on a large scale. BEAUCHAMP PLANTAGENET, in his description of the province of New Albion, published in London, in 1648, states "that the English settlers in Uvedale, now Delaware, had vines running on mulberry and sassafras trees; and enumerates four kinds of grapes, namely: Thoulouse Muscat, Sweet Scented, Great Fox, and Thick Grape; the first two, after five months, being boiled and salted and well fined, make a strong red Xeres; the third, a light claret; the fourth, a white grape which creeps on the land, makes a pure, gold colored wine. TENNIS PALE, a Frenchman, out of these four, made eight sorts of excellent wine; and says of the Muscat, after it had been long boiled, that the second draught will intoxicate after four months old; and that here may be gathered and made two hundred tuns in the vintage months, and that the vines with good cultivation will mend." In 1633, WILLIAM PENN attempted to establish a vineyard near Philadelphia, but without success. After some years, however, Mr. TASKER, of Maryland, and Mr. ANTIL, of Shrewsbury, N.J., seem to have succeeded to a certain extent. It seems, however, from an article which Mr. ANTIL wrote of the culture of the grape, and the manufacture of wine, that he cultivated only foreign varieties. In 1796, the French settlers in Illinois made one hundred and ten hogsheads of strong wine from native grapes. At Harmony, near Pittsburgh, a vineyard of ten acres was planted by FREDERIC RAPP, and his associates from Germany; and they continued to cultivate grapes and silk, after their removal to another Harmony in Indiana. In 1790, a Swiss colony was founded, and a fund of ten thousand dollars raised in Jessamine county, Kentucky, for the purpose of establishing a vineyard, but failed, as they attempted to plant the foreign vine. In 1801, they removed to a spot, which they called Vevay, in Switzerland County, Indiana, on the Ohio, forty-five miles below Cincinnati. Here they planted native vines, especially the Cape, or Schuylkill Muscadel, and met with better success. But, after about forty years' experience, they seem to have become discouraged, and their vineyards have now almost disappeared. These were the first crude experiments in American grape culture; and from some cause or another, they seem not to have been encouraging enough to warrant their continuation. But a new impetus was given to this branch of industry, by the introduction of the Catawba, by Major ADLUM, of Georgetown, D.C., who thought, that by so doing, he conferred a greater benefit upon the nation than he would have done, had he paid the national debt. It seems to have been planted first on an extensive scale by NICHOLAS LONGWORTH, near Cincinnati, whom we may justly call one of the founders of American grape culture. He adopted the system of leasing parcels of unimproved land to poor Germans, to plant with vines; for a share, I believe, of one-half of the proceeds. It was his ambition to make the Ohio the Rhine of America, and he has certainly done a good deal to effect it. In 1858, the whole number of acres planted in grapes around Cincinnati, was estimated, by a committee appointed for that purpose, at twelve hundred acres, of which Mr. LONGWORTH owned one hundred and twenty-two and a half acres, under charge of twenty-seven tenants. The annual produce was estimated by the committee at no less than two hundred and forty thousand gallons, worth about as many dollars then. We may safely estimate the number of acres in cultivation there now, at two thousand. Among the principal grape growers there, I will mention Messrs. ROBERT BUCHANAN, author of an excellent work on grape culture, MOTTIER, BOGEN, WERK, REHFUSS, DR. MOSHER, etc. Well do I remember, when I was a boy, some fourteen years old, how often my father would enter into conversation with vintners from the old country, about the feasibility of grape culture in Missouri. He always contended that grapes should succeed well here, as the woods were full of wild grapes, some of very fair quality, and that this would indicate a soil and climate favorable to the vine. They would ridicule the idea, and assert that labor was too high here, even if the vines would succeed, to make it pay; but they could not shake his faith in the ultimate success of grape culture. Alas! he lived only long enough to see the first dawnings of that glorious future which he had so often anticipated, and none entered with more genuine zeal upon the occupation than he, when an untimely death took him from the labor he loved so well, and did not even allow him to taste the first fruits of the vines he had planted and fostered. Had he been spared until now, his most sanguine hopes would be verified. I also well remember the first cultivated grape vine which produced fruit in Hermann. It was an Isabella, planted by a Mr. FUGGER, on the corner of Main and Schiller streets, and trained over an arbor. It produced the first crop in 1845, twenty years ago, and so plentifully did it bear, that several persons were encouraged by this apparent success, to plant vines. In 1846, the first wine was made here, and agreeably surprised all who tried it, by its good quality. The Catawba had during that time, been imported from Cincinnati, and the first partial crop from it, in 1848, was so plentiful, that every body, almost, commenced planting vines, and often in very unfavorable localities. This, of course, had a bad influence on so capricious a variety as the Catawba; rot and mildew appeared, and many became discouraged, because they did not realize what they had anticipated. A number of unfavorable seasons brought grape growing almost to a stand still here. Some of our most enterprising grape growers still persevered, and succeeded by careful treatment, in making even the Catawba pay very handsome returns. It was about this time, that the attention of some of our grape-growers was drawn towards a small, insignificant looking grape, which had been obtained by a Mr. WIEDERSPRECKER from Mr. HEINRICHS, who had brought it from Cincinnati, and, almost at the same time, by Dr. KEHR, who had brought it with him from Virginia. The vine seemed a rough customer, and its fruit very insignificant when compared with the large bunch and berry of the Catawba, but we soon observed that it kept its foliage bright and green when that of the Catawba became sickly and dropped; and also, that no rot or mildew damaged the fruit, when that of the Catawba was nearly destroyed by it. A few tried to propagate it by cuttings, but generally failed to make it grow. They then resorted to grafting and layering, with much better success. After a few years a few bottles of wine were made from it, and found to be very good. But at this time it almost received its death-blow, by a very unfavorable letter from Mr. LONGWORTH, who had been asked his opinion of it, and pronounced it worthless. Of course, with the majority, the fiat of Mr. LONGWORTH, the father of American grape-culture, was conclusive evidence, and they abandoned it. Not all, however; a few persevered, among them Messrs. JACOB ROMMEL, POESCHEL, LANGENDOERFER, GREIN, and myself. We thought Mr. LONGWORTH was human, and might be mistaken; and trusted as much to the evidence of our senses as to his verdict, therefore increased it as fast as we could, and the sequel proved that we were right. After a few years more wine was made from it in larger quantities, found to be much better than the first imperfect samples; and now that despised and condemned grape is _the_ great variety for red wine, equal, if not superior to, the best Burgundy and Port; a wine of which good judges, heavy importers of the best European wines too, will tell you that it has not its equal among all the foreign red wines; which has already saved the lives of thousands of suffering children, men, and women, and therefore one of the greatest blessings an all-merciful God has ever bestowed upon suffering humanity. This despised grape is now the rage, and 500,000 of the plants could have been sold from this place alone the last fall, if they could have been obtained. Need I name it? it is the Norton's Virginia. Truly, "great oaks from little acorns grow!" and I boldly prophecy to-day that the time is not far distant when thousands upon thousands of our hillsides will be covered with its luxuriant foliage, and its purple juice become one of the exports to Europe; provided, always, that we do not grow so fond of it as to drink it all. I think that this is pre-eminently a Missouri grape. Here it seems to have found the soil in which it flourishes best. I have seen it in Ohio, but it does not look there as if it was the same grape. And why should it? They drove it from them and discarded it in its youth; we fostered it, and do you not think, dear reader, there sometimes is gratitude in plants as well as in men? Other States may plant it and succeed with it, too, to a certain extent, but it will cling with the truest devotion to those localities where it was cared for in its youth. Have we not also found, during the late war, that the Germans, the adopted citizens of this great country, clung with a heartier devotion to our noble flag, and shed their blood more freely for it, than thousands upon thousands of native-born Americans? And why? Because here they found protection, equal rights for all, and that freedom which had been the idol of their hearts, and haunted their dreams by night; because they had been oppressed so long they more fully appreciated the blessings of a free government than those who had enjoyed it from their birth. But you may call me fantastical for comparing plants to human beings, and will say, plants have no appreciation of such things. Brother Skeptic, have you, or has any body, divined _all_ the secrets of Nature's workshop? Truly we may say that we have not, and we meet with facts every day which are stranger than fiction. The Concord had as small a beginning with us. In the winter of 1855 a few eyes of its wood were sent me by Mr. JAS. G. SOULARD, of Galena, Ill. I grafted them upon old Catawba vines, and one of them grew. The next year I distributed some of the scions to our vine-growers, who grafted them also. When my vine commenced to bear I was astonished, after what I had heard of the poor quality of the fruit from the East, to find it so fine, and so luxurious and healthy; and we propagated it as fast as possible. Now, scarcely nine years from the time when I received the first scions, hundreds of acres are being planted with it here, and one-third of an acre of it, planted five years ago, has produced for me, in fruit, wine, layers, cuttings, and plants, the round sum of ten thousand dollars during that time. Its wine, if pressed as soon as the grapes are mashed, is eminently one of those which "maketh glad the heart of man," and is evidently destined to become one of the common drinks of our laboring classes. It is light, agreeable to the palate, has a very enlivening and invigorating effect, and can be grown as cheap as good cider. I am satisfied that an acre will, with good cultivation, produce from 1,000 to 1,500 gallons per year. My vines produced this season at the rate of 2,500 gallons to the acre, but this may be called an extra-large crop. I have cited the history of these two varieties in our neighborhood merely as examples of progress. It would lead too far here, to follow the history of all our leading varieties, though many a goodly story might be told of them. Our friends in the East claim as much for the Delaware and others, with which we have not been able to succeed. And here let me say that the sooner we divest ourselves of the idea that one grape should be _the_ grape for this immense country of ours; the sooner we try to adapt the variety to the locality--not the locality to the variety--the sooner we will succeed. The idea is absurd, and unworthy of a thinking people, that one variety should succeed equally well or ill in such a diversity of soil and climate as we have in this broad land of ours. It is in direct conflict with the laws of vegetable physiology, as well as with common sense and experience. In planting our vineyards we should first go to one already established, which we think has the same soil and location, or nearly so, as the one we are going to plant. Of those varieties which succeed there we should plant the largest number, and plant a limited number also of all those varieties which come recommended by good authority. A few seasons will show which variety suits our soil, and what we ought to plant in preference to all others. Thus the Herbemont, the Cynthiana, Delaware, Taylor, Cunningham, Rulander, Martha, and even the Iona, may all find their proper location, where each will richly reward their cultivator; and certainly they are all too good not to be tried. Now, let us see what progress the country at large has made in grape-growing during, say, the last ten years. _Then_, I think I may safely assert, that the vineyards throughout the whole country did not comprise more than three to four thousand acres. _Now_ I think I may safely call them over two millions of acres. _Then_, our whole list embraced about ten varieties, all told, of which only the Catawba and Isabella were considered worthy of general cultivation; _now_ we count our native varieties by the hundreds, and the Catawba and Isabella will soon number among the things which have been. Public taste has become educated, and they are laid aside in disgust, when such varieties as the Herbemont, Delaware, Clara, Allen's Hybrid, Iona, Adirondac, and others can be had. _Then_, grape-growing was confined to only a few small settlements; _now_ there is not a State in the Union, from Maine to California, but has its vineyards; and especially our Western States have entered upon a race which shall excel the other in the good work. Our brethren in Illinois bid fair to outdo us, and vineyards spring up as if by magic, even on the prairies. Nay, grape-culture bids fair to extend into Minnesota, a country which was considered too cold for almost anything except oats, pines, wolves, bears, and specimens of daring humanity encased in triple wool. We begin to find out that we have varieties which will stand almost anything if they are only somewhat protected in winter. It was formerly believed that only certain favored locations and soils in each State would produce good grapes--for instance, sunny hillsides along large streams; now we begin to see that we can grow some varieties of grape on almost any soil. One of the most flourishing vineyards I have ever seen is on one of the islands in the Missouri river, where all the varieties planted there--some six or seven--seemed perfectly at home in the rich, sandy mould, where it needs no trenching to loosen the soil. _Then_, grape-growing, with the varieties then in cultivation, was a problem to be solved; _now_, with the varieties we have proved, it is a certainty that it is one of the most profitable branches of horticulture, paying thousands of dollars to the acre every year. _Then_, wine went begging at a dollar a gallon; _now_ it sells as fast as made at from two dollars to six dollars a gallon. Instead of the only wine then considered fit to drink, we number our wine-producing varieties by the dozen, all better than the Catawba; among the most prominent of which I will name--of varieties producing white wine, the Herbemont, Delaware, Cassidy, Taylor, Rulander, Cunningham, and Louisiana; of light-red wines, the Concord; of dark-red wines, the Norton's Virginia, Cynthiana, Arkansas and Clinton; so that every palate can be suited. And California bids fair to outdo us all; for there, I am told, several kinds of wine are made from the same grape, in the same vineyard, and in fabulous quantities. To cite an example of the increase in planting: in 1854 the whole number of vines grown and sold in Hermann did not exceed two thousand. This season two millions of plants have been grown and sold, and not half enough to meet the demand. It is said that the tone of the press is a fair indication of public sentiment. If this is true what does it prove? Take one of our horticultural periodicals, and nine-tenths of the advertisements will be "Grape-vines for sale," in any quantity and at any price, from five dollars to one hundred dollars per 100, raised North, East, South, and West. Turn to the reading matter, and you can hardly turn over a leaf but the subject of grapes stares you in the face, with a quiet impunity, which plainly says, "The nation is affected with grape fever; and while our readers have grape on the brain there is no fear of overdosing." Why, the best proof I can give my readers that grape fever does exist to an alarming degree, is this very book itself. Were not I and they affected with the disease, I should never have presumed to try their patience. But, fortunately, the remedy is within easy reach. Plant grapes, every one of you who is thus afflicted, until our hillsides are covered with them, and we have made our barren spots blossom as the rose. Truly, the results we have already obtained, are cheering enough. And yet all this has been principally achieved in the last few years, while the nation was involved in one of the most stupendous struggles the world ever saw, while its very existence was endangered, and thousands upon thousands of her patriotic sons poured out their blood like water, and the husbandman left his home; the vintner his vineyard, to fight the battles of his country. What then shall we become now, when peace has smiled once more upon our beloved country; and the thousands of brave arms, who brandished the sword, sabre, or musket, have come home once more; and their weapons have been turned into ploughshares, and their swords into pruning hooks? When all the strong and willing hands will clear our hillsides, and God's sun shines upon _one_ great and united people; greater and more glorious than ever; because now they are _truly free_. Truly the future lies before us, rich in glorious promise; and ere long the words and the prophecy contained in the old legend will become sober truth, and America will be, from the Atlantic to the Pacific _one_ smiling and happy _Wineland_; where each laborer shall sit under his own vine, and none will be too poor to enjoy the purest and most wholesome of all stimulants, good, cheap, native _wine_. Then drunkenness, now the curse of the nation, will disappear, and peace and good will towards all will rule our actions. And we, brother grape growers? Ours is this great and glorious task; let us work unceasingly, with hand, heart, and mind; truly the object is worthy of our best endeavors. Let those who begin to-day, remember how easy their task with the achievements and experiments of others before them, compared with the labors of those who were the pioneers in the cultivation of the vine. PROPAGATION OF THE VINE. I.--FROM SEED. This would seem to be the most natural mode, were not the grape even more liable to sport than almost any other fruit. It is, however, the only method upon which we can depend for obtaining new and more valuable varieties than we already possess, and to which we are already indebted for all the progress made in varieties, a progress which is, indeed, very encouraging; for who would deny that we are to-day immeasurably in advance of what we were ten years ago. Among the innumerable varieties which spring up every day, and which find ready purchasers, just because they _are new_, there are certainly some of decided merit. But those who grow seedlings, should bear in mind, that the list of our varieties is already too large; that it would be better if three-fourths of them were stricken off, and that no new variety should be brought before the public, unless it has some decided superiority over any of the varieties we already have, in quality, productiveness and exemption from disease. It is poor encouragement to the grape growing public, to pay from two to five dollars a vine for a new variety, with some high-sounding name, if, after several years of superior cultivation and faithful trial, they find their costly pet inferior to some variety they already possessed, and of which the plants could be obtained at a cost of from ten to fifty cents each. The grapes from which the seed is to be used, should be fully ripe, and none but well developed, large berries, should be taken. Keep these during the winter, either in the pulp, or in cool, moist sand, so that their vitality may remain unimpaired. The soil upon which your seed-bed is made, should be light, deep and rich, and if it is not so naturally, should be made so with well decomposed leaf-mould. As soon as the weather in spring will permit, dig up the soil to the depth of at least eighteen inches, pulverising it well; then sow the seed in drills, about a foot apart, and about one inch apart in the rows, covering them about three-quarters of an inch deep. It will often be found necessary to shade the young plants when they come up, to prevent the sun from scalding them, but this should not be continued too long, as the plants will become too tender, if protected too long. When the young plants have grown about six inches, they may be supplied with small sticks, to which they will cling readily; the ground should be kept clean and mellow, and a light mulch should be applied, which will keep the soil loose and moist. The young plants should be closely watched, and if any of them show signs of disease, they should at once be pulled up; also those which show a very feeble and delicate growth; for we should only try to grow varieties with good, healthy constitutions. In the Fall, the young plants should be either taken up, and carefully heeled in, or they should be protected by earth, straw, or litter thrown over them. In the Spring, they may be transplanted to their permanent locations; the tops shortened in to six inches, and the roots shortened in to about six inches from the stem. The soil for their reception should be moderately light and rich, and loosened up to the depth of at least eighteen inches. Make a hole about eight inches deep, then throw in soil so as to raise a small mound in the centre of the hole, about two inches high; on this place the young vine, and carefully spread the roots in all directions; then fill up with well pulverized soil, so that the upper eye or bud is even with the surface of the ground; then press the soil down lightly; place a good stake, of about four feet high, with the plant, and allow but one shoot to grow, which should be neatly tied to the stake as it grows. The vines may be planted in rows six feet apart, and three feet apart in the rows, as many of them will prove worthless, and have to be taken out. Allow all the laterals to grow on the young cane, as this will make it short-jointed and stocky. Cultivate the ground well, stirring it freely with plough, cultivator, hoe, and rake, which generally is the best mulch that can be applied. With the proper care and attention, our seedlings will generally grow from three to four feet, and make stout, short-jointed wood this second season. Should any of them look particularly promising, fruit may be obtained a year sooner by taking the wood of it, and grafting strong old vines with it. These grafts will generally bear fruit the next season. The method to be followed will be given in another place. At the end of the second season the vines should be pruned to about three eyes or buds, and the soil hilled up around them so as to cover them up completely. The next spring take off the covering, and when the young shoots appear allow only two to grow. After they have grown about eighteen inches, pinch off the top of the weakest, so as to throw the growth into the strongest shoot, which keep neatly tied to the stake, treating it as the summer before, allowing all the laterals to grow. Cultivate the soil well. At the end of this season's growth the vines should be strong enough to bear the following summer. If they have made from eight to ten feet of stocky growth, the leading cane may be pruned to ten or twelve eyes, and the smaller one to a spur of two eyes. If they will fruit at all, they will show it next summer, when only those promising well should be kept, and the barren and worthless ones discarded. II.--BY SINGLE EYES. As this method is mostly followed only by those who propagate the vine for sale in large quantities, and but to a limited extent by the practical vineyardist, I will give only an outline of the most simple manner, and on the cheapest plan. Those wishing further information will do well to consult "The Grape Culturist," by Mr. A. S. FULLER, in which excellent work they will find full instructions. The principal advantages of this mode of propagation are the following: 1st. The facility with which new and rare kinds can be multiplied, as every well ripened bud almost can be transformed into a plant. 2d. As the plants are started under glass, by bottom heat, it lengthens the season of their growth from one to two months. 3d. Every variety of grape can be propagated by this method with the greatest ease, even those which only grow with the greatest difficulty, or not at all, from cuttings in open ground. As to the merits or demerits of plants grown under glass from single eyes, to those grown from cuttings or layers in open ground, opinions differ very much, and both have their advocates. For my part, I do not see why a plant grown carefully from a single eye should not be as good as one propagated by any other method; a poor plant is not worth having, whether propagated by this or any other method, and, unfortunately, we have too many of them. THE PROPAGATING HOUSE. I will only give a description of a lean-to of the cheapest kind, for which any common hot-bed sash, six feet long, can be used. Choose for a location the south side of a hill, as, by making the house almost entirely underground, a great deal of building material can be saved. Excavate the ground as for a cellar--say five feet deep on the upper side, seven feet wide, and of any length to suit convenience, and the number of plants you wish to grow. Inside of the excavation set posts or scantlings, the upper row to be seven feet long above the ground, and two feet below the ground; the lower row four and one-half feet above the ground, so that the roof will have about two and one-half feet pitch. Upon these nail the rafters, of two-inch planks. Then take boards, say common inch-plank, and set them up behind the posts, one above the other, to prevent the earth from falling in. This will make all the wall that is needed on both sides. On the ends, boards can be nailed to both sides of the posts, and the intervening space tilled with spent tan or saw-dust. Upon the rafters place the sash on the lower side; the upper side may be covered with boards or shingles, where also the ventilating holes can be left, to be closed with trap-doors. The house is to be divided into two compartments--the furnace-room on one end, about eight feet long, and the propagating house, The furnace is below the ground, say four feet long, the flue to be made of brick, and to extend under the whole length of the bench. To make the flue, lay a row of bricks flat and crosswise; on the ends of these place two others on their edges, and across the top lay a row flat, in the same way as the bottom ones were placed. This gives the flue four inches by eight in the clear. The flue should rise rather abruptly from the furnace, say about a foot; it can then be carried fifty feet with, say six to nine inches rise, and still have sufficient draft. Inside of the propagating room we have again two compartments--the propagating bench, nearest to the furnace, and a shelf for the reception of the young plants, after their first transplanting from the cutting-pots or boxes. Make a shelf or table along the whole length of the house; at the lower end it should be about eighteen inches from the glass, and five feet wide. To a house of, say fifty feet, the propagating bench may be, say twelve feet long, and the room below it and around the flue should be inclosed with boards, as it will keep the heat better. MODE OF OPERATING. The wood should be cut from the vines in the fall, as soon as the leaves have dropped. For propagating, use only firm, well-ripened wood of the last season's growth, and about medium thickness. These are to be preferred to either very large or very small ones. The time to commence operating will vary according to climate; here it should be the early part of February. The wood to be used for propagating can be kept in a cool cellar, in sand, or buried in the ground out doors. Take out the cuttings, and cut them up into pieces as represented in Figure 1. [Illustration: FIG. 1.] Throw these into water as they are cut; it will prevent them from becoming dry. It will be found of benefit with hard-wooded varieties to pack them in damp moss for a week or so before they are put into the propagating pots or boxes; it will soften the alburnous matter, and make them strike root more readily. They should then be put into, say six-inch pots, filled to about an inch of the top with pure coarse sand, firmly packed. Place the cuttings, the buds up, about an inch apart, all over the surface of the pot; press down firmly with thumb and forefinger until the bud is even with the surface; sift on sand enough to cover the upper point of the bud about a quarter of an inch deep; press down evenly, using the bottom of another pot for the purpose, and apply water enough to moisten the whole contents of the pot. Instead of the pots, shallow boxes of about six inches deep, can also be used, with a few holes bored in the bottom for drainage. After the pots have been filled with cuttings they are placed in a temperature of from 40° to 45°, where they remain from two to three weeks, water being applied only enough to keep them moist, not wet. As roots are formed at a much lower degree of temperature than leaves, they should not be forced too much at the beginning, or the leaves will appear before we have any roots to support them. But when the cutting has formed its roots first, the foliage, when it does appear, will grow much more rapidly, and without any check. Then remove them to another position, plunging the pots into sand to the depth of, say three inches, and raise the temperature at first to 60° for the first few days, then gradually raise it to 80°. When the buds begin to push, raise the temperature to 90° or 95°, and keep the air moist by frequent waterings, say once a day. The best for this purpose is pure rain-water, but it should be of nearly the same temperature as the air in the house, for, if applied cold, it would surely check the growth of the plants. The young growth should be examined every day, to see if there is any sign of rotting; should this be the case, give a little more air, but admit no sudden cold currents, as they are often fatal. The glass should be whitewashed, to avoid the direct rays of the sun. When the young vines have made a growth of two or three inches shift them into three-inch pots. So far we have used only pure sand, which did not contain much plant food, because the growth was produced from the food stored up in the bud and wood, and what little they obtained from the sand, water, and air. Now, however, our young vines want more substantial food. They should therefore be potted into soil, mixed from rotten sod, leaf-mould, and well-decomposed old barnyard manure. This should be mixed together six months before using; add, before using, one-quarter sand, then mix thoroughly, and sift all through a coarse sieve. In operating, put a quantity of soil on the potting bench, provide a quantity of broken bricks or potsherds for drainage, loosen the plants from the pots by laying them on their side, giving them a sudden jar with the hand, to loosen the sand around them; draw out the plant carefully, holding it with one hand, while with the other you place a piece of the drainage material into the pot; cover it with soil about an inch; then put in the plant, holding it so that the roots spread out naturally; fill in soil around them until the pot is full; press the soil down firmly, but not hard enough to break the roots. When the plants are potted give them water to settle the earth around the roots, and keep the air somewhat confined for a few days, until they have become established, when more air may be given them. Keep the temperature at 85° to 95° during the day, and 70° to 80° during the night. When the plants have made about six inches of growth they can either be placed in another house, or in hot-bed frames, if they are to be kept under glass. The usual manner of keeping them in pots during summer, shifting them into larger and larger sizes, I consider injurious to the free development of the plants, as the roots are distorted and cramped against the sides of the pots, and cannot spread naturally. I prefer shifting them into cold frames, in which beds have been prepared of light, rich soil, into which the young plants can be planted, and kept under whitewashed hot-bed sashes for a while, which, after several weeks, may be removed, and only a light shading substituted in their place, which, after several weeks more, can also be removed. Thus the young plants are gradually hardened, their roots have a chance to spread evenly and naturally, without any cramping; and such plants, although they may not make as tall a growth as those kept under glass all the season, will really stand transplanting into the vineyard much better than those hot-house pets, which may look well enough, but really are, like spoiled and pampered children, but poorly fitted to stand the rough vicissitudes of every-day life. The young plants should be lightly tied to small sticks provided for the purpose, as it will allow free circulation of air, and admit the sun more freely to the roots. In the fall, after their leaves have dropped, they should be carefully taken up, shortened to about a foot of their growth, and they are then ready either to sell, if they are to be disposed of in that way, or for planting into the vineyard. They should, however, be carefully assorted, making three classes of them--the strongest, medium, and the smallest--each to be put separate. The latter generally are not fit to transplant into the vineyard, but they may be heeled in, and grown in beds another year, when they will often make very good plants. Heeling in may be done as shown in Figure 2, laying the vines as close in the rows as they can conveniently be laid, and then fill the trench with well-pulverized soil. They can thus be safely kept during the winter. [Illustration: FIG. 2.] I have only given an outline of the most simple and cheapest mode of growing plants from single eyes, such as even the vineyardist may follow. For descriptions of more extensive and costly buildings, if they desire them, they had better apply to an architect. I have also not given the mode of propagating from green wood, as I do not think, plants thus propagated are desirable. They are apt to be feeble and diseased, and I think, the country at large would be much better off, had not a single plant ever been produced by that method. Plants from single eyes may also be grown in a common hot-bed; but as in this the heat can not be as well regulated at will, I think it, upon the whole, not desirable, as the expense of a propagating house on the cheap plan I have indicated, is but very little more, and will certainly in the long run, pay much better. Of course, close attention and careful watching is the first requisite in all the operations. III.--BY CUTTINGS IN OPEN AIR. This is certainly the easiest and most simple method for the vineyardist; can be followed successfully with the majority of varieties, which have moderately soft wood, and even a part of the hard wood varieties will generally grow, if managed carefully. MODE OF OPERATING. There are several methods, which are followed with more or less success. I will first describe that which I have found most successful, namely, short cuttings, of two or three eyes each, which are made of any sound, well ripened wood, of last season's growth. Prune the vines in the fall or early winter, and make the cuttings as soon as convenient; for if the wood is not kept perfectly fresh and green, the cuttings will fail to grow. Now, cut up all the sound, well-ripened wood into lengths of from two to four eyes each, making them of a uniform length of say eight inches, and prepare them as shown in Figure 3. [Illustration: FIG. 3.] These should be tied into convenient bundles, from 100 to 250 in each, taking care to even the lower ends, and then buried in the ground, making a hole somewhat deeper than the cuttings are long, into which the bundles are set on their lower ends, and soil thrown in between and over them. In spring, as soon as the ground is dry enough, the cutting-bed should be prepared. Choose for this a light, rich soil, which should be well pulverized, to the depth of at least a foot, and if not light enough, it should be made so by adding some leaf mould. Now draw a line along the whole length of the bed; then take a spade and put it down perpendicular along the line or nearly so, moving it a little backwards and forwards, so as to open the cut. Now take the cutting and press it down into the cut thus made, until the upper bud is even with the surface of the soil. The cuttings may be put close in the rows, say an inch apart, and the rows made two feet apart. Press the ground firmly down with your foot along the line of cuttings, so as to pack it closely around the cutting. After the bed is finished, mulch them with straw, or litter, spent tan or saw-dust, say about an inch thick, and if none of these can be had, leaves from the forest may be used for the purpose. This will serve to protect the young leaves from the sun, and will also keep an even moisture during the heat of summer, at the same time keeping the soil loose and porous. If weeds appear, they should be pulled up, and the cuttings, kept clean through the summer. They will generally make a firm, hardy growth of from one to four feet, have become used to all the hardships and changes of the weather; and as they have formed their roots just where they ought to be, about eight inches below the ground, will not suffer so much from transplanting, as either a single eye or a layer, whose roots have to be put much deeper in transplanting, than they were before, and thus, as it were, become acclimated to the lower regions. For these reasons, I think, that a good plant grown from a cutting is preferable to that propagated by any other method. In the Fall, the vines are carefully taken up, assorted and heeled in, in the same manner as described, with single eyes, and cut back to about three inches of their growth. They are then ready for transplanting into the vineyard. IV.--BY LAYERING. This is a very convenient method of increasing such varieties as will not grow readily from cuttings; and vines thus propagated will, if treated right, make very good plants. To layer a vine, shorten in its last season's growth to about one-half; then prepare the ground thoroughly, pulverizing it well; then, early in spring make a small furrow, about an inch deep, then bend the cane down and fasten it firmly in the bottom of the trench, by wooden hooks or pegs, made for the purpose. They may thus be left, until the young shoots have grown, say six inches; then fill up with finely pulverized soil or leaf-mould. The vines will thus strike root generally at every joint. The young shoots may be tied to small sticks, provided for the purpose, and when they have grown about a foot, their tips should be pinched off to make them grow more stocky. In the Fall they are taken up carefully, commencing to dig at the end furthest removed from the vine, and separate each plant between the joints, so that every shoot has a system of roots by itself. They are then either planted immediately, or heeled in as described before. V.--BY GRAFTING. The principal advantages to be gained by this method are: 1st. The facility by which new and rare kinds may be increased, by grafting them on strong stocks of healthy varieties, when they will often grow from ten to twenty feet the first season, producing an abundance of wood to propagate. 2d. The short time in which fruit can be obtained from new and untried varieties, as their grafts will generally bear the next season. 3d. In every vineyard there are, in these days of many varieties, vines which have proved inferior, yet by grafting into them some superior variety, they may be made very valuable. 4th. The facility by which vines can be forced under glass, by grafting on small pieces of roots, and the certainty with which every bud can thus be made to grow. [Illustration: FIG. 4.] The vine, however, does not unite with the same facility as the pear and apple, and, to ensure success, must be grafted under ground, which makes the operation a difficult and disagreeable one. It will therefore hardly become a general practice; but, for the purposes above named, is of sufficient importance, to make it desirable that every vineyardist should be able to perform it. I have generally had the best success in grafting here about the middle of March, in the following manner: Dig away the ground around the vine you wish to graft, until you come to a smooth place to insert your scion; then cut off the vine with a sharp knife, and insert one or two scions, as in common cleft-grafting, taking care to cut the wedge on the scion very thin, with shoulders on both sides, as shown in Figure 4, cutting your scion to two eyes, to better insure success. Great care must be taken to insert the scion properly, as the inner bark or liber of the vine is very thin, and the success of the operation depends upon a perfect junction of the stock and scion. If the vine is strong enough to hold the scion firmly, no further bandage is necessary; if not, it should be wound firmly and evenly with bass bark. Then press the soil firmly on the cut, and fill up the hole with well pulverized earth, to the top of the scion. Examine the stock from time to time, and remove all wild shoots and suckers, which it may throw up, as they will rob the graft of nourishment and enfeeble it. Others prefer to graft in May, when the leaves have expanded, and the most rapid flow of sap has ceased, keeping the scions in a cool place, to prevent the buds from starting. The operation is performed in precisely the same manner, and will be just as successful, I think, but the grafts that have been put in early, have the advantage of several weeks over the others, and the latter will seldom make as strong a growth, or ripen their wood as well as those put in early. Mr. A. S. FULLER performs the operation in the fall, preventing the graft from freezing by inverting a flower-pot over it, and then covering with straw or litter. He claims for this method--1st. That it can be performed at a time when the ground is more dry, and in better condition, and business not so pressing as in spring.--2d. That the scion and stock have more time to unite, and will form their junction completely during the winter, and will therefore start sooner, and make a more rapid growth than in spring. It certainly looks feasible enough, and is well worth trying, as, when the operation succeeds, it must evidently have advantages over any of the other modes. Vines I had grafted in March have sometimes made twenty to thirty feet of growth, and produced a full crop the next season. This will show one the advantage to be derived from it in propagating new and scarce varieties, and in hastening the fruiting of them. Should a seedling, for instance, look very promising in foliage and general appearance, fruit may be obtained from it from one to two seasons sooner by grafting some of the wood on strong stocks, than from the original plant. Hence the vast importance of grafting, even to the practical vineyardist. THE VINEYARD. LOCATION AND SOIL. As the selection of a proper location is of vast importance, and one of the main conditions of success, great care and judgment should be exercised in the choice. Some varieties of grapes may be grown on almost any soil, it is true; but even they will show a vast difference in the quality of the fruit, even if the quantity were satisfactory; on indifferent soil, and in an inferior location. Everybody should grow grapes enough for his own use, who owns an acre of ground, but every one cannot grow them and make the most delicious wine. The best locations are generally on the hillsides, along our larger rivers, water-courses, and lakes, sloping to the East, South, and Southwest, as they are generally more exempt from late spring frosts and early frosts in fall. The location should be sheltered from the cold winds from the north and northwest, but fully exposed to the prevailing winds in summer from the south and southwest. If a hill is chosen at any distance from a large body of water, it should be high and airy, with as gentle a slope as can be obtained. The locations along creeks and smaller water-courses should be particularly avoided, as they are subject to late spring frosts, and are generally damp and moist. The soil should be a dry, calcareous loam, sufficiently deep, say three feet; if possible, draining itself readily. Should this not be the case naturally, it should be done with tiles. I was much struck by the force of a remark made by medical friend last summer, when, in consequence of the continual rains, the ague was very prevalent. It was this: wherever you will find the ague an habitual guest with the inhabitants you need not look for healthy grapevines. Wherever we find stagnant water let us avoid the neighboring hillsides, for they would not be congenial to our grape-vines. But on the bluffs overhanging the banks of our large streams, especially on the northern and western sides, where the vines are sheltered from the north and west winds, and fully exposed to the warm southern winds of our summer days, and where the fogs arising from the water yet give sufficient humidity to the atmosphere, even in the hottest summer days, to refresh the leaf during the night and morning hours; where the soil on the southern and eastern slopes is a mixture of decomposed stone and leaf-mould, and feels like velvet to the feet--there is the paradise for the grape; and the soil is already better prepared for it than the hand of man can ever do. Such locations should be cheap to the grape-grower at _any_ price. We find them very frequently along the northern banks of the Missouri and Mississippi rivers, and they will no doubt become the favored grape regions of the country. The grape grows there with a luxuriance and health which is almost incredible to those living in less favored locations. But the question may be asked here, what shall be done by those who do not live in these favored regions, and yet would like to grow grapes? I answer, let them choose the best location they have, the most free and airy, and let them choose only those sturdy varieties that withstand everything. They cannot grow the most delicate varieties--the Herbemont, the Delaware, the Clara, are not for them; but they can grow the Concord, Hartford Prolific, and Norton's Virginia, and they at least are "very good," although they may not be the "best." There is no excuse for any one in this country why he should not grow his own grapes, for the use of his family at least, if he has any ground to grow them on. PREPARING THE SOIL. In this, the foundation of all grape-growing, the vineyardist must also look to the condition in which he finds the soil. Should it be free of stones, stumps, and other obstructions, the plough and sub-soil plough will be all-sufficient. Should your soil be new, perhaps a piece of wild forest land, have it carefully grubbed, and every tree and stump taken out by the roots. After the ground is cleared take a large breaking-plough, with three yoke of sturdy oxen, and plough as deep as you can, say twelve to fourteen inches. Now follow in the same furrow with an implement we call here a sub-soil stirrer, and which is simply a plough-share of wedge shape, running in the bottom of the furrow, and a strong coulter, running up from it through the beam of the plough, sharp in front, to cut the roots; the depth of the furrow is regulated by a movable wheel running in front, which can be set by a screw. With two yoke of oxen this will loosen the soil to the depth of, say twenty inches, which is sufficient, unless the sub-soil is very tenacious. In land already cultivated, where there are no roots to obstruct, two yoke of oxen or four horses attached to the plough, and one yoke of oxen or a pair of horses or mules to the sub-soil plough, will be sufficient. In stony soil the pick and shovel must take the place of the plough, as it would be impossible to work it thoroughly with the latter; but I think there is no advantage in the common method of trenching or inverting the soil, as is now practiced to a very great extent. If we examine the growth of our native vines we will generally find their roots extending along the surface of the soil. It is unnatural to suppose that the grape, the most sun-loving of all our plants, should be buried with its roots several feet below the surface of the soil, far beyond the reach of sun and air. Therefore, if you can afford it, work your soil deep and thoroughly; it will be labor well invested; is the best preventive against drouth, and also the best drainage in wet weather; but have it in its natural position--not invert it; and do not plant too deep. Should the soil be very poor it may be enriched by manure, ashes, bone-dust, etc.; but it will seldom be found necessary, as most of our soil is rich enough; and it is not advisable to stimulate the growth too much, as it will be rank and unhealthy, and injurious to the quality and flavor of the fruit. Wet spots may be drained by gutters filled with loose stones, or tiles, and then covered with earth. Surface-draining can be done by running a small ditch or furrow every sixth or eighth row, parallel with the hillside, and leading into a main ditch at the end or the middle of the vineyard. Steep hillsides should be terraced or benched; but, as this is very expensive, they should be avoided. WHAT SHALL WE PLANT? CHOICE OF VARIETIES. It is a very difficult matter, in a vast country like ours, where the soil and climate differ so much, to recommend any thing; and I think it a mistake, into which many of our prominent grape-growers have fallen, to recommend _any_ variety, simply because it succeeded well _with them_, for _general_ cultivation. Grape-growing is, perhaps, more than any other branch of horticulture or pomology, dependent upon soil, location and climate, and it will not do to dictate to the inhabitants of a country, in which the "extremes meet," that they should _all_ plant one variety. Yet this has been done by some who _pretend_ to be authorities, and it shows, more than any thing else, that they have more arrogance than knowledge. I, for my part, have seen such widely different results, from the same varieties, under the same treatment, and in vineyards only a few miles apart, but with a different soil and different aspect, that I am reluctant to recommend to my next neighbor, what he shall plant. But, while the task is a difficult one, yet we may lay down certain rules, which can govern us in selection of varieties to a certain extent. We should choose--1st. The variety which has given the most general satisfaction in the State or county in which we live, or the nearest locality to us. 2d--Visit the nearest accessible vineyard in the month of August and September, observe closely which variety has the healthiest foliage and fruit; ripens the most uniformly and perfectly; and either sells best in market, or makes the best wine, and which, at the same time, is of good quality, and productive enough. Your observations, thus taken, will be a better guide than the opinion of the most skillful grape grower a thousand miles off. I will now name a few of the most prominent varieties which should at least be tried by every grape grower. THE CONCORD. This grape seems to have given the most general satisfaction all over the country, and seems to be _the_ "grape for the million." Wherever heard from, it seems to be uniformly healthy and productive. Our Eastern friends complain of its inferior quality; this may be owing partly to their short seasons, and partly to the too early gathering of the fruit. It is one of those varieties which color early, but should hang a long time after coloring, to attain its full perfection. Here it is at least _very_ good; makes an excellent wine, and, if we take into consideration its enormous productiveness, its vigor and adaptability to all soils and climates, we must acknowledge that as yet it stands without a rival, and will be a safe investment almost anywhere. Our long summers bring it to a perfection of which our Eastern friends have no idea, until they try it here. It will do well in almost any soil. NORTON'S VIRGINIA. This, so far, is the leading grape for red wine, and its reputation here and in the entire West is now so fully established, that it would be difficult indeed to persuade our people into the belief, that any other grape could make a better red wine. It is healthy and uniformly productive, and will be safe to plant, I think, in nearly all the Western States. I rather doubt that our Eastern friends will succeed in making a first class wine from it, as I think their summers are too short, to develop all its good qualities. Will succeed in almost any soil, but attains its greatest perfection in southern slopes with somewhat strong soil. HERBEMONT. This is a truly delicious grape, but somewhat tender, and wants a long season to fully ripen its fruit and bring out all its good qualities. Will hardly do much further north than we are here, in Missouri, but is, I think, destined to be one of the leading grapes for the Southern States. If you have a warm, southern exposure, somewhat stony, with limestone foundation, plant the Herbemont, and you will not be disappointed. It is healthy and very productive; more refreshing than the Delaware, and makes an excellent wine. DELAWARE. Is much recommended by Eastern authorities, and where it succeeds, is certainly a fine grape and makes a delicious wine. Here at the West, it has proved a failure in most locations, being subject to leaf-blight, and a feeble grower. There are some locations, however, where it will flourish; and whoever is the fortunate possessor of such a one should not forget to plant it. It seems to flourish best in light, warm, somewhat sandy soil. HARTFORD PROLIFIC. This is immensely productive; of very fair quality here; hardy and healthy; and if planted for early marketing, will give general satisfaction. It hangs well to the bunch, and even makes a very fair wine. Will flourish in almost every soil. CLINTON. Hardy, healthy and productive; will make a fair wine, but is here not equal even to the Concord, and far behind the Norton's Virginia in quality. May be desirable further north. PLANTING. The distance at which the vines may be planted will of course vary somewhat with the growth of the different varieties. The rows may all be six feet apart, as this is the most convenient distance for cultivating, and gives ample space for a horse and man to pass through with plough or cultivator. Slow-growing varieties, such as the Delaware and Catawba, may be planted six feet apart in the rows, making the distance six feet each way; but the Concord, Norton's Virginia, Herbemont, Hartford Prolific, Cunningham, and all the strong growers, will need more room, say ten feet in the rows, so as to give the vines ample room to spread, and allow free circulation of air--one of the first conditions of health in the vines, and quality of the fruit. The next question to be considered is: Shall we plant cuttings or rooted plants? My preference is decidedly for the latter, for the following reasons: Cuttings are uncertain, even of those varieties which grow the most readily; and we cannot expect to have anything like an even growth, such as we can have if the plants are carefully assorted. Some of the cuttings will always fail, and there will be gaps and vacancies which are hard to fill, even if the strongest plants are taken for replanting. Therefore, let us choose plants. But we should not only choose rooted plants, but the best we can get; and these are good one year old, whether grown from cuttings, layers or single eyes. A good plant should have plenty of strong, well-ripened roots; not covered with excrescences and warts, which is always a sign of ill health; but smooth and firm; with well-ripened, short-jointed wood. They should be of uniform size, as they will then make an even stand in the vineyard, when not forced by the propagator into an unnaturally rank growth by artificial manures. This latter consideration, I think, is very important, as we can hardly expect such plants, which have been petted and pampered, and fed on rich diet, to thrive on the every-day fare they will find in the vineyard. Do not take second or third rate plants, if you can help it; they may live and grow, but they will never make the growth which a plant of better quality would make. We may hear of good results sometimes, obtained by planting second-rate plants, but certainly the results would be better if better plants had been chosen. Especially important is the selection of good plants with those varieties which do not propagate and transplant readily, such as the Norton's Virginia, Delaware, and other hard-wood varieties. Better pay double the price you would have to give for inferior plants; the best are the cheapest in the end, as they will make the healthiest vines, and bear sooner. But I would also caution my readers against those who will sell you "extra large layers, for _immediate_ bearing," and whose "plants are better than those whom anybody else may grow," as their advertisements will term it. It is time that this humbug should cease; time that the public in general should know, that they cannot, in nature and reason, expect any fruit from a plant transplanted the same season; and that those who pretend it can be done, without vital injury to the plant, are only seeking to fill their pockets at the cost of their customers. They know well enough themselves that it cannot be done without killing or fatally injuring the plant, yet they will impose upon the credulity of their confiding customers; make them pay from $3 to $5 a piece for a plant, which these good souls will buy, with a vision of a fine crop of grapes before their eyes, plant them, with long tops, on which they may obtain a few sickly bunches of fruit the first season; but if they do the vines will make a feeble growth, not ripen their fruit, and perhaps be winter-killed the next season. It is like laying the burden of a full grown man on the shoulders of a child; what was perhaps no burden at all to the one, will kill the other. Then, again, these "plants, superior to those of every one else." It is the duty of every propagator and nursery-man to raise good plants; he can do it if he tries; it is for his interest as much as for the interest of his customers to raise plants of the best quality; and we have no reason to suppose that we are infinitely superior to our neighbors. While the first is a downright swindle, the latter is the height of arrogance. If we had a good deal less of bombast and self laudation, and more of honesty and fair dealing in the profession, the public would have more confidence in professional men, and would be more likely to practice what we preach. Therefore, if you look around for plants, do not go to those who advertise, "layers for immediate bearing," or "plants of superior quality to all others grown;" but go to men who have honesty and modesty enough to send you a sample of their best plants, if required, and who are not averse to let you see how they grow them. Choose their good, strong healthy, one year old plants, with strong, firm, healthy roots, and let those who wish to be humbugged buy the layers for _immediate_ bearing. You must be content to wait until the third year for the first crop; but, then, if you have treated your plants as you ought to do, you can look for a crop that will make your heart glad to see and gather it. You cannot, in reason and nature expect it sooner. If your ground has been prepared in the Fall, so much the better, and if thrown into ridges, so as to elevate the ground somewhat, where the row is to be, they may be planted in the Fall. The advantages of Fall planting are as follows: The ground will generally work better, as we have better weather in the Fall; and generally more time to spare; the ground can settle among the roots; the roots will have healed and callused over, and the young plant be ready to start with full vigor in spring. [Illustration: FIG. 5.] Mark your ground, laying it off with a line, and put down a small stick or peg, eighteen inches long, wherever a plant is to stand. Dig a hole, about eight to ten inches deep, as shown in Figure 5, in a slanting direction, raising a small mound in the bottom, of well-pulverized, mellow earth; then, having pruned your plant as shown in Figure 6, with its roots and tops shortened in, as shown by the dotted lines, lay it in, resting the lower end on the mound of earth, spread out its roots evenly to all sides, and then fill in among the roots with rich, well-pulverized earth, the upper bud being left above the ground. When planted in the fall, raise a small mound around your vine, so that the water will drain off, and throw a handful of straw or any other mulch on top, to protect it. Of course, the operation should be performed when the ground is dry enough to be light and mellow, and will readily work in among the roots. [Illustration: FIG. 6.] TREATMENT OF THE VINE THE FIRST SUMMER. The first summer after planting nothing is necessary but to keep the ground free from weeds, and mellow, stirring freely with hoe, rake, plough, and cultivator, whenever necessary. Should the vines grow strong they may be tied to the stakes provided in planting, to elevate them somewhat above the ground. Allow all the laterals to grow, as it will make the wood stronger and more stocky. They may even be summer-layered in July, laying down the young cane, and covering the main stem about an inch deep with mellow soil, leaving the ends of the laterals out of the ground. With free-growing kinds, such as the Concord and Hartford Prolific, these will generally root readily, and make very good plants, the laterals making the stems of the layers. With varieties that do not root so readily, as the Delaware and Norton's Virginia, it will seldom be successful, and should not be practiced. The vineyard may thus be made to pay expenses, and furnish the vines for further plantations the first year. They are taken up and divided in the fall, as directed in the chapter for layers. In the fall, prune the vine to three buds, if strong enough, to one or two if it has only made a weak growth. A fair growth is from four to five feet the first summer. During the winter, trellis should be provided for the vines, as we may expect them to grow from twelve to fifteen feet the coming summer. The cheapest and most economical are those of strong upright posts, say four inches in diameter, made of red cedar if it can be had, if not, of any good, durable timber--mulberry, locust, or white oak--and seven feet long, along which No. 10 wire is stretched horizontally. Make the holes for the posts with a post-hole auger, two feet deep; set in the posts, charred on one end, to make them durable. If wire is to be used, one post every sixteen feet will be enough, with a smaller stake between, to serve as a support for the wires. Now stretch your wire, the lowest one about two feet from the ground, the second one eighteen inches above it, and the third eighteen inches above the second. The wires may be fastened to the posts by nails, around which they can be twisted, or by loops of wire driven into the post. Where timber is plenty, laths made of black oak may be made to serve the same purpose; but the posts must then be set much closer, and the wire will be the cheapest and neatest in the end. A good many grape-growers train their vines to stakes, believing it to be cheaper, but I have found it more expensive than trellis made in the above manner, and it is certainly a very slovenly method, compared with the latter. Trellis is much more convenient for tying the vines, the canes can be distributed much more evenly, and the fruit and young wood, not being huddled and crowded together as on stakes, will ripen much more evenly, and be of better quality, as the air and sun have free access to it. TREATMENT OF THE VINE THE SECOND SUMMER. We find the young vine at the commencement of this season pruned to three buds of the last season's growth. From these we may expect from two to three strong shoots or canes. Our first work will be to cultivate the whole ground, say from four to six inches deep, ploughing between the rows, and hoeing around the vines with a two-pronged German hoe, or _karst_. Figure 7 shows one of these implements, of the best form for that purpose. The ground should be completely inverted, but never do it in wet weather, as this will make the ground hard and cloggy. [Illustration: FIG. 7.] Of the young shoots, if there are three, leave only the two strongest, tying the best of them neatly to the trellis with bass, or pawpaw bark, or rye straw. If a Catawba or Delaware, you may let them grow unchecked, tying them along the uppermost wire, when they have grown above it. The Concord, Herbemont, Norton's Virginia, and other strong-growing varieties, I treat in the following manner: When the young shoot has reached the second wire I pinch off its leader. This has the tendency to force the laterals into stronger growth, each forming a medium-sized cane. On these we intend to grow our fruit the coming season, as the buds on these laterals will generally produce more and finer fruit than the buds on the strong canes. Figure 8 will show the manner of training the second summer, with one cane layered, for the purpose of raising plants. This is done as described before; only, as the vine will make a much stronger growth this season than the first, the layering maybe done in June, as soon as the young shoots are strong enough. Figure 9 shows the vine pruned and tied, at the end of the second season. Figure 10 illustrates the manner of training and tying the Catawba or Delaware. [Illustration: FIG. 8. FIG. 9.] [Illustration: FIG. 10.] The above is a combination of the single cane and bow system, and the horizontal arm training, which I first tried on the Concord from sheer necessity; when the results pleased me so much that I have adopted it with all strong-growing varieties. The circumstances which led me to the trial of this method were as follows: In the summer of 1862, when my Concord vines were making their second season's growth, we had, in the beginning of June, the most destructive hail storm I have ever seen here. Every leaf was cut from the vines, and the young succulent shoots were all cut off to about three to three and a half feet above the ground. The vines, being young and vigorous, pushed out the laterals vigorously, each of them making a fair-sized cane. In the fall, when I came to prune them, the main cane was not long enough, and I merely shortened in the laterals to from four to six buds each. On these I had as fine a crop of grapes as I ever saw, fine, large, well-developed bunches and berries, and a great many of them, as each had produced its fruit-bearing shoot. Since that time I have followed this method altogether, and obtained the most satisfactory results. The ground should be kept even and mellow during the summer, and the vines neatly tied to the trellis with bast or straw. There are many other methods of training; for instance, the old bow and stake training, which is followed to a great extent around Cincinnati, and was followed to some extent here. But it crowds the whole mass of fruit and leaves together so closely that mildew and rot will follow almost as a natural consequence, and those who follow it are almost ready to give up grape-culture in despair. Nor is this surprising. With their tenacious adherence to so fickle a variety as the Catawba, and to practices and methods of which experience ought to have taught them the utter impracticability long ago, we need not be surprised that grape-culture is with them a failure. We have a class of grape-growers who never learn, nor ever forget, anything; these we cannot expect should prosper. The grape-grower, of all others, should be a close observer of nature in her various moods, a thinking and a reasoning being; he should be trying and experimenting all the time, and be ready always to throw aside his old methods, should he find that another will more fully meet the wants of his plants. Only thus can he expect to prosper. There is also the arm system, of which we hear so much now-a-days, and which certainly looks very pretty _on paper_. But paper is patient, and while it cannot be denied that it has its advantages, if every spur and shoot could be made to grow just as represented in drawings, with three fine bunches to each shoot; yet, upon applying it practically, we find that vines are stubborn, and some shoots will outgrow others; and before we hardly know how, the whole beautiful system is out of order. It may do to follow in gardens, on arbors and walls, with a few vines, but I do not think that it will ever be successfully followed in vineyard culture for a number of years, as it involves too much labor in tying up, pruning, etc. I think the method described above will more fully meet the wants of the vinyardist than any I have yet seen tried; it is so simple that every intelligent person can soon become familiar with it, and it gives us new, healthy wood for bearing every season. Pruning may be done in the fall, as soon as the leaves have dropped. TREATMENT OF THE VINE THE THIRD SEASON. At the commencement of the third season, we find our vine pruned to two spurs of two eyes each, and four lateral canes, of from four to six eyes each. These are tied firmly to the trellis as shown in Figure 12, for which purpose small twigs of willows (especially the golden willow, of which every grape-grower should plant a supply) are the most convenient. The ground is ploughed and hoed deeply, as described before, taking care, however, not to plough so deep as to cut or tear the roots of the vine. Our vines being tied, ploughed, and hoed, we come to one of the most important and delicate operations to be performed; one of as great--nay, greater--importance than pruning. I mean summer-pruning, or pinching, _i.e._ thumb or finger pruning. Fall-pruning, or cutting back, is but the beginning of the discipline under which we intend to keep our vines; summer-pruning is the continuation, and one is useless, and cannot be followed systematically without the other. Let us look at our vine well, before we begin, and commence near the ground. The time to perform the first summer-pruning is when the young shoots are about six to eight inches long, and when you can see plainly all the small bunches or buttons--the embryo fruit. We commence on the lower two spurs, having two buds each. From these two shoots have started. One of them we intend for a bearing cane next summer; therefore allow it to grow unchecked for the present, tying it, if long enough, to the lowest wire. The other, which we intend for a spur again next fall, we pinch with thumb and finger to just beyond the last bunch or button, taking out the leader between the last bunch and the next leaf, as shown in Figure 11, the cross line indicating where the leader is to be pinched off. We now come to the next spur, on the opposite side, where we also leave one cane to grow unchecked, and pinch off the other. We now go over all the shoots coming from the arms or laterals tied to the trellis, and also pinch them beyond the last bunch. Should any of the buds have pushed out two shoots, we rub off the weakest; we also take off all barren or weak shoots. If any of them are not sufficiently developed we pass them over, and go over the vines again, in a few days after the first pinching. [Illustration: FIG. 11.] This early pinching of the shoot has a tendency to throw all the vigor into the development of the young bunch, and the leaves remaining on the shoot, which now grow with astonishing rapidity. It is a gentle checking, and leading the sap into other channels; not the violent process which is often followed long after the bloom, when the wood has become so hardened that it must be cut with a knife, and by which the plant is robbed of a large quantity of its leaves, to the injury of both fruit and vine. Let any of my readers, who wish to satisfy themselves, summer-prune a vine, according to the method described here, and leave the next vine until after the bloom, and he will plainly perceive the difference. The merit of first having practised this method here, which I consider one of vast importance in grape-culture, belongs to Mr. WILLIAM POESCHEL, of this place, who was led to do so, by observing the rapid development of the young bunches on a shoot which had accidentally been broken beyond the last bunch. Now, there is hardly an intelligent grape-grower here, who does not follow it; and I think it has added more than one-third to the quantity and quality of my crop. It also gives a chance to destroy the small, white worm, a species of leaf-folder, which is very troublesome just at this time, eating the young fruit and leaves, and which makes its web among the tender leaves at the end of the shoot. The bearing branches having all been pinched back, we can leave our vines alone until after the bloom, only tying up the young canes from the spurs, should it become necessary. But do not tie them over the bearing canes, but lead them to the empty space on both sides of the vine; as our object must be to give the fruit all the air and light we can. By the time the grapes have bloomed, the laterals will have pushed from the axils of the leaves on the bearing shoots. Now go over these again, and pinch each lateral back to one leaf, as shown in Figure 12. This will make the leaf which remains grow and expand rapidly, serving at the same time as a conductor of sap to the young bunch opposite, and shading it when it becomes fully developed. The canes from the spurs, which we left unchecked, and which we design to bear fruit the next season, may now also be stopped or pinched, when they are about three feet long, to start their laterals into stronger growth. Pinch off all the tendrils; this is a very busy time for the vine-dresser, and upon his close attendance and diligence now, depends, in a great measure, the value of his crop. Besides, "a stitch in time saves nine," and he can save an incredible amount of labor by doing everything at the proper time. [Illustration: FIG. 12.] In a short time, the laterals on the fruit-bearing branches which have been pinched will throw out suckers again. These are stopped again, leaving one leaf of the young growth. Leave the laterals on the canes intended for next years' fruiting to grow unchecked, tying them neatly with bass, or pawpaw bark, or with rye straw. This is about all that is necessary for this summer, except an occasional tying up of a fruiting branch, should its burden become more than it can bear. But the majority of the branches will be able to sustain their fruit without tying, and the young growth which may yet start from the laterals may be left unchecked, as it will serve to shade the fruit when ripening. Of course, the soil must be kept clean and mellow, as in the former summer. This short pruning is also a partial preventative against mildew and rot, and the last extremely wet season has again shown the importance of letting in light and air to all parts of the vine; as those vineyards, where a strict system of early summer pruning had been followed, did not suffer half as much from rot and mildew as those where the old slovenly method still prevailed. My readers will perceive, that Fall-pruning, or shortening-in the ripened wood of the vine, and summer-pruning, shortening in and thinning out the young growth, have one and all the same object in view, namely, to keep the vine within proper bounds, and concentrate all its energies for a two-fold object, namely, the production and ripening of the most perfect fruit, and the production of strong, healthy wood for the coming season's crop. Both operations are, in fact, only different parts of one and the same system, of which summer-pruning is the preparatory, and fall pruning the finishing part. If we think that a vine is setting more fruit than it is able to bear and ripen perfectly, we have it in our power to thin it, by taking away all imperfect bunches, and feeble shoots. We should allow no more wood to grow than we need for next season's bearing; if we allow three canes to grow where only two are needed, we waste the energies of the vine, which should all be concentrated upon ripening its fruit in the most perfect condition, and producing the necessary wood for next season's bearing, and that of the best and most vigorous quality, but no more. If we prune the vine too long, we over-tax its energies; making it bear more fruit than it can perfect, and the result will be poor, badly-ripened fruit, and small and imperfect wood. If, on the contrary, we prune the vine too short, we will have a rank, excessive growth of wood and leaves, and encourage rot and mildew. Only practice and experience will teach us the exact medium, and the observing vintner will soon find out where he has been wrong, better than he can be taught by a hundred pages of elaborate advice. Different varieties will require different treatment, and it would be foolishness to suppose that two varieties so entirely different, as for instance, the Concord and the Delaware, could be pruned, trained and pinched in the same manner. The first, being a rank and vigorous grower, with long joints, will require much longer pruning than the latter, which is a slow-growing, short-jointed vine. Some varieties, the Taylor for instance, also the Norton, will fruit better if pruned to spurs on old wood, than on the young canes; it will therefore be the best policy for the vintner in pruning these, to retain the old arms or canes, pruning all the healthy, strong shoots they have to two buds, as long as the old arms remain healthy; always, however, growing a young cane to fall back upon, should the old arm become diseased; whereas, the Catawba and Delaware, being only moderate growers, will flourish and bear best when pruned short, and to a cane of last season's growth. The Concord and Herbemont, again, will bear best on the laterals of last season's growth, and should be trained accordingly. Therefore it is, because only a few of the common laborers will take the pains to think and observe closely, that we find among them but few good vine-dressers. At the end of this season, we find our Concords or Herbemonts, with the old fruit-bearing cane, and a spur on each side, from which have grown two canes; one of which was stopped, like all other fruit-bearing branches, and which we now prune to a spur of two eyes; and another, which was stopped at about three feet, and on which the laterals were allowed to grow unchecked. We therefore have one of these canes, with its laterals, on each side of the vine. These laterals are now pruned precisely as the last season, each being cut back to from four to six eyes, and the old cane, which has borne fruit, is cut away altogether. With Norton's Virginia, Taylor, and some others, which will bear more readily on spurs from old wood, the old cane is retained, provided the shoots on it are sound and healthy, with well developed buds; the weak ones are cut away altogether, and the others cut back to two eyes each. One of the canes is pruned, as in the Concord, to be tied to one side of the trellis, the next spring. This closes our summer and fall pruning for the third year. Of the gathering of the fruit, as well for market as for wine, I shall speak in another chapter. TREATMENT OF THE VINE THE FOURTH SUMMER. We may now consider the vine as established, able to bear a full crop, and when tied to the trellis in spring, to present the appearance, as shown in Fig. 13. The operations to be performed are precisely the same as in its third year. [Illustration: FIG. 13.] In addition, I will here remark, that in wet seasons the soil of the vineyard should be stirred as little as possible, as it will bake and clog, and in dry seasons it should be deeply worked and stirred, as this loose surface-soil will retain moisture much better than a hard surface. Should the vines show a decrease in vigor, they may be manured with ashes or compost, or still better, with surface-soil from the woods. This will serve to replenish the soil which may have been washed off and is much more beneficial than stable manure. When the latter is applied, a small trench should be dug just above the vine, the manure laid in, and covered with soil. But an abundance of fresh soil, drawn up well around the vine, is certainly the best of all manures. Where a vine has failed to grow the first season, replant with extra strong vines, as they will find it difficult to catch up with the others; or the vacancy can be filled up the next season, by a layer from a neighboring vine, made in the following manner: Dig a trench from the vine to the empty place, about eight to ten inches deep, and bend into it one of the canes of the vine, left to grow unchecked for that purpose, and pruned to the proper length. Let the end of it come out to the surface of the ground with one or two eyes above it, at the place where the vine is to be, and fill up with good, well pulverized earth. It will strike roots at almost every joint, and grow rapidly, but, as it takes a good deal of nourishment from the parent vine, that must be pruned much shorter the first year. When the layer has become well established, it is cut from the parent vine; generally the second season. Pruning is best done in the fall, but it can be done on mild days all through the winter months, even as late as the middle of March. Fall-pruning will prevent all flow of sap, and the cuttings are also better if made in the fall, and buried in the ground during winter. All the sound, well-ripened wood of last season's growth may be made into cuttings, which may be either planted, as directed in a former chapter, or sold; and are an accession to the product of the vineyard not to be despised, for they will generally defray all expenses of cultivation. TRAINING THE VINES ON ARBORS AND WALLS. This is altogether different from the treatment in vineyards; the first has for its object to grow the most perfect fruit, and to bring the vine, with all its parts, within the easy reach and control of the operator; in the latter, our object is to cover a large space with foliage, for ornament and shade, fruit being but a secondary consideration. However, if the vine is treated judiciously, it will also produce a large quantity of fruit, although not of as good quality as in the vineyard. [Illustration: FIG. 14. FIG. 15.] Our first object must be to grow very strong plants, to cover a very large space. Prepare a border by digging a trench two feet deep and four feet wide. Fill with rich soil, decomposed leaves, burnt bones, ashes, etc. Into this plant the strongest plants you have, pruned as for vineyard planting. Leave but one shoot to grow on them during the first summer, which, if properly treated, will get very strong. Cut back to three buds the coming fall. These will each throw out a strong shoot, which should be tied to the arbor they are designed to cover, as shown in Figure 14, and allowed to grow unchecked. In the fall following cut each shoot back to three buds, as our first object must be to get a good basis for our vines. These will give us nine canes the third summer; and as the vine is now thoroughly established and strong, we can begin to work in good earnest. It will be perceived that the vine has three different sections or principal branches, each with three canes. Cut one of these back to two eyes, and the other two to six or eight buds each, according to the strength of the vine, as shown in Figure 15. The next spring tie these neatly to the trellis, and when the young shoots appear thin out the weakest, and leave the others to grow unchecked. The next fall cut back as indicated by the black cross lines, the weakest to be cut back to one or two eyes, and the stronger ones to three or four, the spurs at the bottom to come in as a reserve, should any of the branches become diseased. Figure 16 shows the manner of pruning. [Illustration: FIG. 16.] In this manner a vine can be made, in course of time, to cover a large space, and get very old. The great vine at Windsor Palace was planted more than sixty years ago, and in 1850 it produced two thousand large bunches of magnificent grapes. The space covered by the branches was one hundred and thirty-eight feet long, and sixteen feet wide, and it had a stem two feet nine inches in circumference. This is one of the largest vines on record. They should, however, be strongly manured to come to full perfection. Other authorities prefer the Thomery system of training, but I think it much more complicated and difficult to follow. Those wishing to follow it will find full directions in DR. GRANT'S and FULLER'S books, which are very explicit on this method. OTHER METHODS OF TRAINING THE VINE. There are many other systems in vogue among vine-dressers in Germany and France, but as our native grapes are so much stronger in growth, and are in this climate so much more subject to mildew and rot, I think these methods, upon the whole, but poorly adapted to the wants of our native grapes, however judicious they may be there. I will only mention a few of them here; one because it is to a great extent followed in Mexico and California, and seems to suit that dry climate and arid soil very well; and the other, because it will often serve as a pretty border to beds in gardens. The first is the so-called buck or stool method of training. The vine is made to form its head--_i.e._, the part from which the branches start--about a foot above the ground, and all the young shoots are allowed to grow, but summer-pruned or checked just beyond the last bunch of grapes. The next spring all of the young shoots are cut back to two eyes, and this system of "spurring in" is kept up, and the vine will in time present the appearance of a bush or miniature tree, producing all its fruit within a foot from the head, and without further support than its own stem. Very old vines trained in this manner often have twenty to twenty-five spurs, and present, with their fruit all hanging in masses around the main trunk, a pleasing but rather odd aspect. This method could not be applied here with any chance of success only to those varieties which are slow growers, and at the same time very hardy. The Delaware would perhaps be the most suitable of all varieties I know for a trial of this method; such strong growers as the Concord and Norton's Virginia could never be kept within the proper bounds, and it would be useless to try it on them. It might be of advantage on poor soil, where there is at the same time a scarcity of timber. Figure 17 shows an old vine pruned after this method. [Illustration: FIG. 17.] The other method of dwarfing the grape is practiced to make a pretty border along walks in gardens, and is as follows: Plant your vines about eight feet apart; treat them the first season as in common vineyard planting, but at the end of the first season cut back to two eyes. Now provide posts, three to three and a half feet long; drive them into the ground about eighteen inches to two feet, which can be easily done if they are pointed at one end, and nail a lath on top of them. This is your trellis for the vines, and should be about eighteen inches above the ground when ready. Now allow both shoots which will start from the two buds to grow unchecked; and when they have grown above the trellis, tie one down to the right, the other to the left, allowing them to ramble at will along it. The next fall they are each cut back to the proper length, to meet the next vine, and in spring tied firmly to the lath, as shown in Figure 18. When the young shoots appear, all below the trellis are rubbed off, but all those above the trellis are summer-pruned or pinched immediately beyond the last bunch of grapes, as in vineyard culture, and the trellis, with its garland of fruit, will present a very pretty appearance throughout the summer. In the fall all of these shoots are pruned to one bud, from which will grow the fruit-bearing shoot for the next season, as shown in Figure 19; and the same treatment is repeated during the summer and fall. [Illustration: FIG. 18. FIG. 19.] DISEASES OF THE VINE. I cannot agree with Mr. FULLER that the diseases of the vine are not formidable in this country. They are so formidable that they threaten to destroy some varieties altogether; and the Catawba, once the glory and pride of the Ohio vineyards, has for the last fifteen years suffered so much from them, that many of the grape-growers who are too narrow-minded to try anything else are about giving up grape-growing in despair. It is very fortunate, therefore, that we have varieties which do not suffer from these diseases, or only in a very slight degree; and my advice to the beginner in grape-culture would be, "not to plant largely of any variety which is subject to disease." Men may talk about sulphuring, and dusting their vines with sulphur through bellows; but I would rather have vines which will bear a good crop without these windy appliances. We can certainly find some varieties for _every_ locality which do not need them, and these we should plant. The mildew is our most formidable disease, and will very often sweep away two-thirds of a crop of Catawbas in a few days. It generally appears here from the first to the fifteenth of June, after abundant rains, and damp, warm weather. It seems to be a parasitic fungus, and sulphur applied by means of a bellows, or dusted over the fruit and vine is said to be a partial remedy. Close and early summer-pruning will do much to prevent it, throwing, as it does, all the strength of the vine into the young fruit, developing it rapidly, and also allowing free circulation of air. In some varieties--for instance, the Delaware--it will only affect the leaves, causing them to blight and drop off, after which the fruit, although it may attain full size, will not ripen nor become sweet, but wither and drop off prematurely. In seasons when the weather is dry and the air pure, it will not appear. It is most prevalent in locations which have a tenacious subsoil, and under-draining will very likely prove a partial preventive, as excess of moisture about the roots is no doubt one of its causes. The gray rot, or so-called grape cholera, generally follows the mildew, and I think that the latter is the principal cause of it, as I have generally found it on berries whose stems have been injured by the mildew. The berry first shows a sort of gray marbling; in a day or two it turns to a grayish-blue color, and finally withers and drops from the bunch. It will continue to affect berries until they begin to color, but only attack a few varieties--the Catawba, To Kalon, Kingsessing, and sometimes the Diana. The spotted, or brown rot, will also attack many of our varieties; it is very destructive to the Isabella and Catawba, and even the Concord is not quite free from it. But it is, after all, not very destructive, and not half as dangerous as the mildew or gray rot. Early and close summer-pruning is a partial preventative against all these diseases, as it will hasten the development of the fruit, allow free circulation of air, and the young leaves which appear on the laterals after pinching seem to be better able to withstand the effects of the mildew, often remaining fresh and green, and shading the fruit, when the first growth of leaves have already dropped. But "an ounce of prevention is better than a pound of cure," and our best preventive is to plant none but healthy varieties. A grape, however good it may be in quality, is not fit for general cultivation if seriously affected with any of these diseases. Nothing can be more discouraging to the grape-grower than to see his vines one day rich in the promise of an abundant crop, and a few days afterwards see two-thirds or three-fourths swept away by disease. It is because I have so often felt this bitter disappointment, that I would warn my readers against planting varieties subject to them. I would save _them_ from the discouragement and bitter losses which I have experienced, when it was out of my power to prevent it. They _can_ prevent it, for the grape-growing of to-day is no longer the same uncertain occupation it was ten years ago. We of to-day have our choice of varieties not subject to disease; let us make it judiciously, and we may be sure of a paying crop every year. INSECTS INJURIOUS TO THE GRAPE. The grape has many enemies of this kind, but if they are closely watched from the beginning their ravages are easily kept within proper bounds. The common gray cut-worm will often eat the young tender shoots of the vine, and draw them into the ground below. Wherever this is perceived the rascal can easily be found by digging for him under some of the loose clods of ground below the vine, and should be destroyed without mercy. [Illustration: FIG. 20. DELAWARE.--_Berries 1/2 diameter_.] Small worms, belonging to the family of leaf-folders, some of them whitish gray, some bluish green, will in spring make their webs among the young, downy leaves at the end of the shoots, eating the young bunches or buttons, and the leaves. These can be destroyed when summer pruning for the first time. Look close for them, as they are very small; yet very destructive if let alone. A small, gray beetle, of about the size and color of a hemp-seed, will often eat a hole into the bud, when it is just swelling, and thus destroy it. He is very shy, and will drop from the vine as soon as you come near him. It is a good plan to spread a newspaper under the vine, and then shake it, when he will drop on the paper and can be caught. Another bug, of about the size of a fly, gray, with round black specks, will sometimes pay us a visit. They will come in swarms, and eat the upper side of the leaves, leaving only the skeletons. They are very destructive, devouring every leaf, as far as they go; they can also be shaken off on a paper or sheet spread under the vine. The thrip, a small, rather three-cornered, whitish-green insect, has of late been very troublesome, as they eat the under side of the leaves of some varieties, especially the Delaware and Norton's Virginia, when the leaf will show rusty specks on the surface, and finally drop off. It has been recommended to go through the vineyard at night, one man carrying a lighted torch, and the other beating the vines, when they will fly into the flame, and be burnt. They are a great annoyance, and have defoliated whole vineyards here last fall. Another leaf-folder makes his appearance about mid-summer, making its web on the leaf, drawing it together, and then devouring his own house. It is a small, greenish, and very active worm, who, if he "smells a rat," will drop out of his web, and descend to the ground in double-quick time. I know of no other plan, than to catch him and crush his web between the finger and thumb. The aphis, or plant louse, often covers the young shoots of the vine, sucking its juices. When a shoot is attacked by them, it will be best to take it off and crush them under your feet, as the shoot is apt to be sickly afterwards, any way. The grape vine sphynx will be found occasionally. It is a large, green worm, with black dots, and very voracious. Fortunately, it is not numerous, and can easily be found and destroyed. There are also several caterpillars--the yellow bear, the hog caterpillar, and the blue caterpillar, which will feed upon the leaves. The only remedy I know against them is hand picking, but they have not as yet been very numerous, nor very destructive. Wasps are sometimes very troublesome when the fruit ripens, stinging the berries and sucking the juice. A great many can be caught by hanging up bottles, with a little molasses, which they will enter, and get stuck in the molasses. BIRDS. These are sometimes very troublesome at the time of ripening, and especially the oriole is a "hard customer," as he will generally dip his bill into every berry; often ruining a fine bunch, or a number of them, in a short time. I have therefore been compelled to wage a war upon some of the feathered tribe, although they are my especial favorites, and I cannot see a bird's nest robbed. However, there are some who do not visit the vineyard, except for the purpose of destroying our grapes, and these can not complain if we "won't stand it any longer," but take the gun, and retaliate on them. The oriole, the red bird, thrush, and cat bird are among the number, and although I would like to spare the latter three, in thankful remembrance of many a gratuitous concert, the first must take his chance of powder and lead, for the little rascal is too aggravating. A few dry bushes, raised above the trellis will serve as their resting place before they commence their work of destruction, where they can be easily killed. FROSTS. Although our winters are seldom severe enough to destroy the hardy varieties, yet they will often fatally injure such half hardy varieties as the Herbemont and Cunningham, and the severe winter of 1863,-'64, killed even the Catawba, down to the snow line, and severely injured the Norton's Virginia, and even the Concord. Fortunately, such winters occur but rarely, and even in localities where the vines are often destroyed by the severe cold in winter, this should deter no one from growing grapes, as, with very little extra labor he can protect them, and bring them safely through the winter. I always cover my tender varieties, in fact, all that I feel not quite safe to leave out, even in severe winters, in the following manner: The vines are properly pruned in the fall; then select a somewhat rainy day, when the canes will bend more easily. One man goes through the rows, and bends the canes to the ground along the trellis, while another follows with the spade, and throws earth enough on them to hold them in their places. Afterwards, I run a plough through the rows, and cover them up completely. In the spring when all danger from frost is over, I take a so-called spading fork, and lift the vines. The entire cost of covering an acre of grape vines and taking them up again in spring, will not exceed $10; surely a trifling expense, if we can thereby ensure a full crop. We have thus a protection against the cold in winter, but I know none against early frosts, in fall, and late spring frosts; and the grape grower should therefore avoid all localities where they are prevalent. The immediate neighborhood of large streams, or lakes, will generally save the grape grower from their disastrous influence; and our summers, here, along the banks of the Missouri river, are in reality full two months longer than they are in the low, small valleys, only four to six miles off. Let the grape grower, in choosing a locality, look well to this, and avoid the hills along these narrow valleys. Either choose a location sufficiently elevated, to be beyond their influence, or, what is better still, choose it on the bluffs above our large streams; where the atmosphere, even in the heat of summer, will never become too dry for the health of the vine. It is a sad spectacle to see the hopes of a whole summer frustrated by one cold night; to see the vines which promised an abundant crop but the day before, browned and wilted beyond all hopes of recovery, and the cheerless prospect before you, that it may occur every spring; or to see the finest crop of grapes, when just ripening, scorched and wilted by just one night's frost, fit for nothing but vinegar. Therefore, look well to this, when you choose the site of your vineyard, and rather pay five times the price for a location free from frost, than for the richest farm along the so-called creek bottoms, or worse still, sloughs of stagnant water. GIRDLING THE VINE TO HASTEN MATURITY. The practice of girdling to induce early ripening is supposed to have been invented by Col. BUCHATT, of Metz, in 1745. He claimed for it that it would also greatly improve the quality of the fruit, as well as hasten maturity. That it accomplishes the latter, cannot be denied; it also seems to increase the size of the berries, but I hardly think the fruit can compare in flavor with a well developed bunch, ripened in the natural way. As it may be of practical value to those who grow grapes for the market, enabling them to supply their customers a week earlier at least, and also make the fruit look better, and be of interest to the amateur cultivator, I will describe the operation for their benefit. [Illustration: FIG. 21 NORTON'S VIRGINIA--_Berries 1/3 diameter._] It can be performed either on wood of the same season's growth, or on that of last year, but in any case only upon such as can be pruned away the next fall. If you desire to affect the fruit of a whole arm or cane, cut away a ring of bark by passing your knife all around it, and making another incision from a quarter to half an inch above the first, taking out the intermediate piece of bark clean, down to the wood. It should be performed immediately after the fruit is set. The bunches of fruit above the incision will become larger, and the fruit ripen and color finely, from a week to ten days before the fruit on the other canes. Of course, the cane thus girdled, cannot be used for the next season, and must be cut away entirely. The result seems to be the consequence of an obstruction to the downward flow of the sap, which then develops the fruit much faster. Ripening can also be hastened by planting against the south side of a wall or board fence, when the reflection of the rays of the sun will create a greater degree of warmth. But nothing can be so absurd and unnatural than the practice of some, who will take away the leaves from the fruit, to hasten its ripening. The leaves are the lungs of the plants; the conductors and elevators of sap; and nothing can be more injurious than to take them away from the fruit at the very time when they are most needed. The consequence of such an unwise course will be the wilting and withering of the bunches, and, should they ripen at all, they will be deficient in flavor. Good fruit must ripen _in the shade_, only thus will it attain its full perfection. Another practice very injurious to the vines is still in practice in some vineyards, and cannot be too strongly condemned. It is the so-called "cutting in" of the young growth in August. Those who practice it, seem to labor under the misapprehension that the young canes, after they have reached the top of the trellis, and are of the proper length and strength for their next year's crop, do not need that part of the young growth beyond these limits any more, and that all the surplus growth is "of evil." Under the influence of this idea they arm themselves with a villainous looking thing called a bill-hook, and cut and slash away at the young growth unmercifully, taking away one-half of the leaves and young wood at one fell swoop. The consequence is a stagnation of sap: the wood they have left, cannot, and ought not to ripen perfectly, and if anything like a cold winter follows, the vines will either be killed entirely, or very much injured at least. The intelligent vine dresser will tie his young canes, away from the bearing wood as much as he can, to give the fruit the fullest ventilation; but when they have reached the top of the trellis, tie them along it and let them ramble as they please. They will thus form a natural roof over the fruit, keep off all injurious dews, and shade the grapes from above. There is nothing more pleasing to the eye than a vineyard in September, with its wealth of dark green foliage above, and its purple clusters of fruit beneath, coyly peeping from under their leafy covering. Such grapes will have an exquisite bloom, and color, as well as thin skin and rich flavor, which those hanging in the scorching rays of the sun can never attain. MANURING THE VINE. As remarked before, this will seldom be necessary, if the vintner is careful enough to guard against washing of the top-soil, and to turn under all leaves, etc., with the plow in the Fall. The best manure is undoubtedly fresh surface soil from the woods. Should the vines, however, show a material decrease in vigor, it may become necessary to use a top-dressing of decomposed leaves, ashes, bone-dust, charcoal, etc. Fresh stable-yard manure I would consider the last, and only to be used when nothing better can be obtained. Turn under with the plow, as soon as the manure is spread. Nothing, I think, is more injurious than the continual drenching with slops, dish-water, etc., which some good souls of housewives are fond of bestowing on their pet grape vines in the garden. It creates a rank, unwholesome growth, and will cause mildew and rot, if anything can. THINNING OF THE FRUIT. This will sometimes be necessary, to more fully develop the bunches. The best thinning is the reduction of the number of bunches at the time of the first summer pruning. If a vine shows more fruit, than the vine dresser thinks it can well ripen, take away all weak and imperfect shoots, and also all the small and imperfect bunches. If the number of bunches on the fruit bearing branches is reduced to two on each, it will be no injury, but make the remaining number of bunches so much more perfect. Thinning out the berries on the bunches, although it will serve to make the remaining berries more perfect and larger, is still a very laborious process, and will hardly be followed to any extent in vineyards, although it can well be practised on the few pet vines of the amateur, and will certainly heighten the beauty of the bunches and berries. RENEWING OLD VINES. Should a vine become old and feeble, it can be renewed by layering. The vine is prepared in the following manner: Prune all the old wood away, leaving but one of the most vigorous of your canes; then dig a trench from the vine along the trellis, say three feet long, eight inches deep; into this bend down the old vine, stump, head and all, fastening it down with a strong hook, if necessary, letting the end of the young cane come out about three eyes above the ground, and fill up with rich, well pulverized soil. The vine will make new roots at every joint, and become vigorous, and, so to say, young, again. Some recommend this process for young vines, the first year after planting; but if good plants have been chosen and planted, it will not be necessary. Feeble and poor plants may need this process, but if plants have good strong roots when planted, (and _only_ such should be planted when they can be obtained), they will not be benefited by it. A FEW NECESSARY IMPROVEMENTS. _Pruning Shears._ These are very handy, and with them the work can be done quicker, and with less labor, as but a slight pressure of the hand will cut a strong vine. Fig. 22 will show the shape of one for heavy pruning. They are made by J. T. HENRY, Hampden, Connecticut, and can be had in almost all hardware stores. The springs should be of brass, as steel springs are very apt to break. A much lighter and smaller kind, with but one spring, is very convenient for gathering grapes, as it will cut the stem easily and smoothly, and not shake the vine, as cutting with the knife will do. They are also handy to clip out unripe and rotten berries, and should be generally used instead of knives. [Illustration: FIG. 22] _Pruning Saws._ It will sometimes be necessary to use these, to cut out old stumps, etc., although, if a vine is well managed, it will seldom be necessary. Fig. 23 will show a kind which is very convenient for the purpose, and will also serve for orchard pruning; the blade is narrow, connected with the handle, and can be turned in any direction. [Illustration: FIG. 23.] GATHERING THE FRUIT FOR MARKET. In this, the vineyardist, of course, only aims at profit, and for that purpose the grapes are often gathered when they are hardly colored--long before they are really ripe--because the public will generally buy them at a high price. Let us hope, however, that better taste will in time prevail, and that even a majority of the public will learn to appreciate the difference between ripe and unripe fruit. I would advise my readers at least to wait until the fruit is fully and evenly colored; for it is our duty to do all we can to correct this vicious leaning towards swallowing unripe fruit, which is so prevalent in this nation, and the producer will not lose anything either, because his fruit will look much better, it will therefore bring the same price which half ripened fruit would have brought, even a week sooner, and will weigh heavier. Every grape will generally color full two weeks before it is fully ripe; and as they are one of the fruits that will not ripen _after_ they are gathered, they will shrivel and look indifferent if gathered before. To ship them to market any distance, they should be packed in low, shallow boxes, say six inches high, so that they will hold about two layers of grapes. Cut the branches carefully, with as long a stem as possible, for more convenient handling, taking care to preserve all the bloom, and clipping out all the unripe berries. They are generally weighed in the basket before packing. Now put a layer of vine leaves on the bottom of the box; then make a layer of grapes, laying them as close as possible; then put a layer of leaves over them; on them put another layer of grapes, filling up evenly; then spread leaves rather thickly over them, and nail on the cover. The box should be perforated with holes, to admit some air. The grapes must be perfectly dry when gathered, and the box should be well filled to prevent shaking and bruising. PRESERVING THE FRUIT. For this purpose, the fruit must be thoroughly ripe. When fully ripe, the stem will turn brown, and shrivel somewhat. The fruit is then carefully gathered, and laid upon a dry floor, or shelves, for a day or two, so that some of the moisture will evaporate. They can then be packed in boxes, in about the same manner as described before, but paper will be better than leaves for this purpose. They are then put away on shelves, in an airy room, which must, however, be free from frost, in an even temperature of from 30° to 40°. They should be examined from time to time, and the decayed berries taken out. They may thus be kept for several months. GATHERING THE FRUIT TO MAKE WINE. For this purpose, the grapes should hang as long as it is safe to allow them; for it will make a very material difference in the quality of the wine, as the water will evaporate, and only the sugar remain; and the flavor or the bouquet will only be fully developed in fully ripened fruit. For gathering, use clean tin or wooden pails; cut the stems as short as possible, and clip or pinch out all unripe or rotten berries, leaving none but fully ripe berries on the bunch. The further process will be described under "wine making." VARIETIES OF GRAPES. I would here, again remark, that I consider the question of "what to plant" as chiefly a local one, for which I do not presume to lay down fixed rules; but which every one must, to a certain extent, determine for himself, by visiting vineyards as nearly similar in soil and location to the one he intends to plant, and then closely observing the habits of the varieties after planting. Only thus can we obtain certain results; not by following blindly in the footsteps of so-called authorities, who may live a hundred, or a thousand miles from us, and whose success with certain varieties, on soil entirely different from ours, under different atmospheric influences, can by no means be taken by us as evidence of our success under other circumstances. CLASS 1.--_Varieties most generally used._ CONCORD. Originated with Mr. E. BULL, of Concord, Mass. This variety seems to be the choice of the majority throughout the country, and however much opinions may differ about its quality, nobody seems to question its hardiness, productiveness, health and value as a market fruit. Here it is of very good quality--and our Eastern brethren have no idea what a really well ripened Missouri grown Concord grape is. It seems to become better the further it is grown West and South; an observation which I think applies with equal force to the Hartford Prolific, Norton's Virginia, Herbemont and others. Bunch large, heavy shouldered--somewhat compact; berries large, round, black, with blue bloom; buttery, sweet and rich _here_, when well ripened; with very thin skin and tender pulp. A strong and vigorous grower; with healthy, hardy foliage; free from mildew, and but slightly subject to rot; succeeds well in almost any soil; and is, so far, the most profitable grape we grow. A fine market fruit, and also makes a fine, light red wine, which is generally preferred to the Catawba. Can be easily grown from cuttings. NORTON'S VIRGINIA, (NORTON'S SEEDLING, VIRGINIA SEEDLING). Originated by DR. N. NORTON, of Richmond, Virginia. This grape has opened a new era in American grape culture, and every successive year but adds to its reputation. While the wine of the Catawba is often compared to Hock, in the wine of Norton's Virginia, we have one of an entirely different character; and it is a conceded fact that the best red wines of Europe are surpassed by the Norton as an astringent, dark red wine, of great body, fine flavor, and superior medical quality. Vine vigorous and hardy, productive; starting a week later in the Spring than the Catawba, yet coloring a week sooner; and will succeed in almost any soil, although producing the richest wine in warm, southern aspects. Bunches medium, compact; berries small, black, sweet and rich; with dark bluish red juice; only moderately juicy. Healthy in all locations, as far as I know, but I doubt its utility in the East, as I do not think the summers warm and long enough. Seems to attain its greatest perfection in Missouri, but is universally esteemed in the West. Very difficult to propagate, as it will hardly grow from cuttings in open air. [Illustration: FIG. 24. HERBEMONT.--_Berries 1/3 diameter._] HERBEMONT (HERBEMONT MADEIRA, WARREN). Origin uncertain. Wherever this noble grape will succeed and fully ripen, it is hard to find a better, for table, as well as for wine. Its home seems to be the South; and I think it will become one of the leading varieties, as soon as the new order of things has been fully established, and free, intelligent labor has taken the place of the drudging, dull toil of the slave. It is particularly fond of warm, southern exposures, with light limestone soil, and it would be useless to plant it on soil retentive of moisture. Bunch long, large shouldered and compact; berry medium, black, with blue bloom--"bags of wine," as Downing fitly calls them; skin thin, sweet flesh, without pulp, juicy and high flavored, never clogs the palate; fine for the table, and makes an excellent wine, which should be pressed immediately after mashing the grapes, when it will be white, and of an exquisite flavor; generally ripens about same time as Catawba. A very vigorous and healthy grower, but tender in rich soils, and should be protected in winter. Extremely productive. HARTFORD PROLIFIC. Raised by Mr. STEEL, of Hartford, Conn.: hardy, vigorous and productive; bunch large, shouldered, rather compact; berry full medium, globular, with a perceptible foxy flavor; skin thick, black, covered with blue bloom; flesh sweet, juicy; much better here than at the East; of very fair quality for its time of ripening; hangs well to the bunch here, although said to drop at the East. For market, this is perhaps as profitable as any variety known, as it ripens very early and uniformly, producing immense crops. I have made wine from it, which, although not of very high character, yet ranks as fair. CLINTON. Origin uncertain; from Western New York; vigorous, hardy and productive; free from disease; bunch medium, long and narrow, generally shouldered, compact; berry medium, roundish oblong, black, covered with bloom; juicy; somewhat acid; colors early, but should hang late to become thoroughly ripe; brisk vinous flavor, but somewhat of the aroma of the frost grape; makes a dark red wine, of good body, and much resembling claret, but not equal to Norton's Virginia, or even the Concord, in my estimation. Although safe and reliable, I think it has lately been over praised as a wine grape, and as it is a very long, straggling grower, it is one of the hardest vines to keep under control. Propagates with the greatest ease. DELAWARE. First disseminated and made known to the public by Mr. A. THOMPSON, of Delaware, Ohio. This is claimed by many to be the best American grape; and although I am inclined to doubt this, and prefer, for my taste, a well ripened Herbemont, it is certainly a very fine fruit. Unfortunately, it is very particular in its choice of soil and location, and it seems as if there are very few locations at the West where it will succeed. Whoever has a location, however, where it will grow vigorously and hold its leaves, will do well to plant it almost exclusively, as it makes a wine of very high character, and is very productive. A light, warm soil seems to be the first requisite, and the bluffs on the north side of the Missouri river seem to be peculiarly adapted to it, while it will not flourish on those on the south side. Bunch small, compact, and generally shouldered; berry below medium, round; skin thin, of a beautiful flesh-color, covered with a lilac bloom; very translucent; pulp sweet and tender, vinous and delicious; wood very firm; short-jointed; somewhat difficult to propagate, though not so much so as Norton's Virginia. Subject in many locations, to leaf-blight, and is _there_ a very slow grower. Fine for the table, and makes an excellent white wine, equal to, if not superior, to the best Rhenish wines, which sells readily at from five to six dollars per gallon. Although I cannot recommend it for general cultivation, it should be tried every where, and planted extensively where it will succeed. Ripens about five days later than Hartford Prolific. CLASS 2.--_Healthy varieties promising well_. CYNTHIANA (RED RIVER). Origin unknown--said to come from Arkansas. This grape promises fair to become a dangerous rival to Norton's Virginia, which variety it resembles so closely in wood and foliage, that it is difficult if not impossible to distinguish it from that variety. The bunch and berry are of the same color as Norton's Virginia, but somewhat larger, and more juicy; sweeter, with not quite as much astringency, and perhaps a few days earlier. Makes an excellent dark red wine, with not as much astringency, but even more delicate aroma, and was pronounced the "best red wine on exhibition," at the last meeting of the State Horticultural Society, where it was in competition with eight samples of the Norton's Virginia. A strong grower, and productive; as difficult to propagate as the Norton. Mr. FULLER evidently has not the true variety, when he calls it worthless, and identical with the Chippewa and Missouri, from both of which it is entirely distinct. ARKANSAS. Closely resembles the foregoing, and will also make an excellent wine of a similar character. I consider both of these varieties as great acquisitions, as they are perfectly healthy, very productive, and will make a wine unsurpassed in merit by any of their class. TAYLOR (BULLITT.) This grape, under proper treatment, has proved very productive with me, and will make a wine of very high quality. The bunches and berries are small, it is true; but not much more so than the Delaware; it also sets its fruit well, and as it is hardy, healthy, and a strong grower, it promises to be one of our leading wine grapes. Bunches small, but compact, shouldered; berry small; white at the East; pale flesh-color here; round, sweet, and without pulp; skin very thin. Requires long pruning on spurs, to bring out its fruitfulness. [Illustration: FIG. 25. HARTFORD PROLIFIC.--_Berries 1/2 diameter._] MARTHA. This new grape, grown from the seed of the Concord, by that enthusiastic and warm-hearted horticulturist, SAMUEL MILLER, of Lebanon, Pa., promises to be one of the greatest acquisitions to our list of really hardy and good grapes, which have lately come before the public. It has fruited with me the last extremely unfavorable season, and has stood the hardest test any grape could be put to, without flinching. Bunch medium, but compact and heavy, shouldered; berry pale yellow, covered with a white bloom; perhaps a trifle smaller than the Concord; round; pulpy, but sweet as honey, with only enough of the foxy aroma to give it character; juicy--very good. I esteem it more highly than any other white grape I have, as it has the healthy habit and vigorous growth of its parent, and promises to make an excellent white wine. Hangs to the bunch well, and will ripen some days before the Concord. MAXATAWNEY. Another very promising white grape--a strong grower, and healthy; may be somewhat too late in the east, but will, I think, be valuable at the West and South. Bunch medium to large---not shouldered; berry above medium; oval; pale yellow, with a slight amber tint on one side; pulp tender, sweet and sprightly; few seeds; fine aroma; quality, best. Ripens about same time as Catawba; seems to be productive. ROGERS' HYBRID, NO. 1. This variety, which is also too late in ripening for the East, to be much esteemed there, fruited with me last season, and more than fulfilled all the expectations I entertained of it. It is the best of Mr. ROGERS' Hybrids, which I have yet tasted; and its productiveness, healthy habit, large berry, and good quality, makes it one of the most desirable of all the grapes we raise here, for the table and market. Bunch medium, loose, shouldered; berry very large, oblong, pale flesh-color; skin thin; pulp tender; few seeds, separating freely from the pulp; sweet, vinous and juicy; quality very good. Ripens about same time as Catawba. It is to be regretted that Mr. ROGERS has not named some of the best of his hybrids, as the numbers give rise to many mistakes, and a great deal of confusion. It would be in the interest of grape-growing if this was avoided, by naming at least the best of them. CREVELING, (CATAWISSA) (BLOOM). This grape, although not quite perhaps so early as has been claimed for it--ripening about five days after Hartford Prolific--is yet of much better quality; and if it only should prove productive enough, will no doubt make an excellent wine. Bunch long, loose, shouldered; berry full medium, black, round, with little bloom; pulp tender; dark juice, sweet and very good--seems to be hardy and healthy. NORTH CAROLINA SEEDLING. Bunch large, shouldered, compact; berry large, oblong, black, with blue bloom; pulpy, but sweet and good; ripens only a few days after Hartford Prolific--very productive, hardy and healthy; strong grower. One of the most showy market grapes we have--not much smaller than Union Village--and as it ripens evenly, and is of very fair quality, is quite a favorite in the market. Makes also a wine of very fair quality. CUNNINGHAM. For the West, and very likely further South, this is a very desirable grape for wine, of the Herbemont class. Bunch compact and heavy, sometimes shouldered; berry rather small, black, without pulp, juicy sweet and good; productive, but somewhat tender; strong grower; should be covered in Winter; makes a very delicious wine, of the Madeira class, which very often remains sweet for a whole year. Ripens late, about a week after the Catawba. RULANDER. Mr. FULLER evidently does not know this grape, as he says it is the same as Logan. The Rulander we have here, is claimed to be a true foreign variety. I am inclined to think, however, that it is either a seedling from foreign seed, raised in the country, or one of the Southern grapes of the Herbemont class. Be this as it may however, it certainly bears no resemblance to the Logan, which is a true Fox, of the Labrusca family. Vine a strong, vigorous, short-jointed grower, with heart-shaped, light green, smooth leaves; very healthy, and more hardy than either the Herbemont or Cunningham. Bunch rather small, very compact, shouldered; berry small, black, without pulp, juicy sweet and delicious; not subject to rot or mildew: makes a delicious, high flavored wine, but not a great deal of it. The wine of this variety is certainly one of the most delicate and valuable ones we have yet made here and on the soil around Hermann, it will, I think, take preference over the Delaware. Ripens a few days later than Concord. LOUISIANA (BURGUNDER). Introduced here by Mr. F. MUENCH, who received it from Mr. THEARD, of Louisiana, where it has been cultivated for some time. Some claim that it is the grape which makes the famous white Burgundy wine of Europe. I am inclined to think it is also a native, grown from foreign seed, like the foregoing, which it closely resembles in foliage and wood; but will, I think, make a wine of still higher quality, perhaps the most delicate white wine we yet have. It can hardly be distinguished from the Rulander in appearance, but has a more sprightly flavor. Ripens at the same time. ALVEY (HAGAR). This nice little grape will certainly make one of the most delicious red wines we have, if it can only be raised in sufficient quantity. It is healthy and moderately productive, but a slow grower. Bunch loose, small, shouldered; berry small, black, without pulp, juicy, sweet and delicious; quality best. Ripens about the same time as the Concord. CASSADY. Bunch medium, very compact, shouldered; berry medium, round, greenish-white, covered with white bloom; thick skin, pulpy, but very sweet, and of fine flavor; makes an excellent white wine; very productive, but somewhat subject to leaf-blight in wet seasons; does not rot or mildew. [Illustration: FIG. 26. CONCORD.--_Berries 1/2 diameter._] BLOOD'S BLACK. Has often been confounded with Mary Ann, as both varieties were disseminated here, by different persons, under the same name. The true Blood's Black is a few days later than Hartford Prolific; bunch heavy and compact, shouldered; berry round, black, full medium, of very fair quality, and an excellent early market grape. The vine is healthy, hardy, and enormously productive. UNION VILLAGE. Perhaps the largest native grape, of fair quality; bunch large, heavy and compact, shouldered; berry very large, oval, black, with blue bloom, pulpy, but juicy, sweet and good. Of better quality here than Isabella; tolerably free from disease, and a splendid market and table fruit. Ripens rather late. PERKINS. For those who do not object to a good deal of foxy flavor, this will be a valuable market grape, on account of its earliness, beautiful color, and great productiveness. Mr. FULLER has evidently not the true variety, as he describes it as a "black grape, sour and worthless." Bunch medium, compact, shouldered; berry full medium, oval, flesh-color, with a beautiful lilac bloom; very sweet, pulpy and foxy. Ripens at same time with Hartford Prolific. Vine a strong grower, healthy and hardy. CLARA. For family use, there is at present no grape here at the West, which is superior to this in quality; and although it will not pay to plant largely, either for market or wine, yet no one who can appreciate a really good grape, should be without a few vines of it at least. Bunch long, rather loose, shouldered; berry medium, pale yellow, translucent, without pulp, sweet, juicy, and of excellent flavor; vine moderately productive and healthy. Ripens with Catawba. IVES' SEEDLING, (IVES' MADEIRA). This variety is recommended so much lately, as a superior grape for red wine, that I will mention it here, although I have not yet fruited it. It was first introduced by Col. WARING, of Hamilton County, Ohio, and is said to be free from rot, healthy and vigorous, and to make an excellent red wine, the must having sold from the press at $4 to $5 per gallon. The following description is from bunches sent me from Ohio last fall: Bunch medium, compact, shouldered; berry rather below medium, black, oblong, juicy, sweet and well flavored; ripens about the time of the Concord. Vine vigorous and healthy; said to propagate with the greatest ease; evidently belonging to the Labrusca species. We have a seedling here of the Norton's Virginia, raised by Mr. F. LANGENDORFER, of this neighborhood, which promises to be a valuable wine grape for this location. It has not yet been named, and the owner says will never receive a name, unless it proves, in some respect, superior to anything we have yet. He has fruited it twice, and made wine from it the last season, which is of a very high character, resembling Madeira, of a brownish-yellow color; splendid flavor, and of great body. The vine is a strong grower, healthy and very productive; bunch long, seldom shouldered, very compact; berry small, black, with blue bloom; only moderately juicy, and ripens a week later than its parent. I am inclined to think that it will be of great value here and further south as a wine grape, although it would ripen too late to suit the climate further north. It may be expected here that I should speak of the Iona, Israella, and Adirondac, as many, and good authorities too, think they will be very valuable. The Iona and Israella have fruited but once with me, last summer, and my experience, therefore, has not been long enough to warrant a decided opinion. As far as it goes, however, it has been decidedly unfavorable. My Iona vine set about twenty five bunches, but mildewed and rotted so badly, that I hardly saved as many berries. It may improve in time, but I hardly think it will do for our soil; whatever it may do for others--and I cannot put it down as "promising well." It is a grape of fine quality, _where it will succeed_. The Israella stood the climate and bad weather bravely, but ripened at least five days later than the Hartford Prolific close by, and was not as good in quality as that grape; in fact, the most insipid and tasteless grape I ever tried. They may both improve, however, upon closer acquaintance, or be better in other locations. Here, I do not feel warranted in praising them, and a description will hardly be needed, as their originator has taken good care to so fully bring their merits, real or imaginary, before the grape-growing community, that it would be superfluous for me to describe them. The Adirondac I saw and much admired at the East, in 1863; and if its originator, Mr. BAILEY, had only been liberal enough to furnish me with a scion of two eyes, for which I offered to pay him at the rate of a dollar per eye, I would, perhaps, be able to report about it. Instead of the scion, he sent me a dried up vine, which had no life in it when I received it, and in consequence of these disadvantages, I have not been able to fruit it yet. It seems to be healthy and vigorous, however; and should the quality of the fruit be the same as at the East, may be a valuable acquisition. On this list I have only mentioned those which have fruited here from four to five years, with very few exceptions, and which have generally, during that time, proved successful. To fully warrant the recommendation of a grape for general cultivation I think, we should have fruited it at least five or six years; and although there are many on this list which I should not hesitate to plant largely, yet I have preferred to be rather a little over cautious than too sanguine. CLASS 3.--_Healthy varieties, but inferior in quality._ MINOR SEEDLING, (VENANGO). This grape has attracted some attention lately--some persons claiming for it superior qualities as a _wine_ grape, even classing it with the Delaware, a statement which I cannot believe. It is a rank Fox, and I can therefore hardly think it will make a wine to suit a fastidious palate. Bunch medium, very compact, sometimes shouldered; berry full medium, pale red, round, sweet, but very pulpy and foxy. Ripens later than Catawba; is very productive, vigorous and healthy--not subject to rot. [Illustration: FIG. 27. CREVELING.--_Berries 1/2 diameter._] MARY ANN. The earliest grape we have--healthy, hardy and productive--but in point of quality, a rather poor Isabella, which it much resembles. Bunch full medium, moderately compact, shouldered; berry medium, oval, black, pulpy, with a good deal of acidity, and strong flavor. Ripens about four to five days before the Hartford Prolific, but is much inferior to that variety in quality. NORTHERN MUSCADINE. Very productive and healthy, but too foxy, and liable to drop from the bunch when ripe. Bunch medium, compact, sometimes shouldered; berry round, brown, sweet, very foxy--pulpy. Ripens about five days later than Hartford Prolific. LOGAN. Ripens about same time with Hartford Prolific--but rather inferior in quality. Bunch long, loose, shouldered; berry medium, oval; resembling Isabella. BROWN. Resembling Isabella, but more free from disease; good grower and productive; will suit those who like the Isabella. HYDE'S ELIZA, (CANBY'S AUGUST). Bunch medium, compact; berry medium, round, black, juicy; rather pleasant, but unproductive, and of little value, where better varieties can be had. MARION PORT. Resembles the foregoing; may, perhaps, make a better wine, but cannot be recommended. POESCHEL'S MAMMOTH. Grown here, from seed of the Mammoth Catawba, by Mr. MICHAEL POESCHEL. Bunch medium, compact, sometimes shouldered; berry very large, round, pale red, pulpy; rather deficient in flavor, but very large; free from disease. Ripens a week later than Catawba. CAPE (ALEXANDER, SCHUYLKILL MUSCADELL). Bunch rather small, compact; berry medium, black, round, pulpy, rather sweet, dark juice. Said to make a good red wine, but my experience has not been favorable. Ripens late--a week after the Catawba. DRACUT AMBER. A Fox Grape, pale red, pulpy, inferior in quality and color to Perkins, which it closely resembles; ripens about same time. ELSINBURGH, (MISSOURI BIRD'S EYE). This old variety was largely disseminated under the latter name, by NICHOLAS LONGWORTH, of Cincinnati. It is a nice little grape; but too unproductive to be of any value here, although it makes a very superior wine. Bunch long and loose, shouldered; berry small, round, black, moderately juicy, with little pulp, sweet and good. Ripens a week before the Catawba. GARBER'S ALBINO. A grape of very fair quality, and rather early, but a shy bearer. Bunch small, rather loose; berry medium, pale yellow, sweet and good. FRANKLIN. A strong grower; said to be very productive; resembling Clinton in foliage and general habit. Bunch small, compact; berry below medium, black, juicy, with a marked frost grape flavor, and hardly worthy of cultivation. LENOIR. Of the Herbemont class, but about a week earlier; of good quality, but too unproductive to be recommended. Bunch medium, compact, shouldered; berry small, round, black, sweet and good. NORTH AMERICA. Early and hardy, but too unproductive, and bunch too small. Bunch small, shouldered; berry round; of very good quality for its season; black, juicy. Ripens as early as Hartford Prolific. CLASS 4.--_Varieties of good quality, but subject to disease._ CATAWBA. This well known grape was brought into notice by Major ADLUM, of Georgetown, D.C., who thought he had, by its introduction, conferred a greater boon upon the American people, than if he had paid the national debt. For the last ten years, it has been so much subject to disease, that it cannot be recommended any longer, except for some peculiar locations. It is said to be healthy in northern Illinois and Iowa, where it will not stand the winter, however, without protection. Bunch large, moderately compact, shouldered; berry medium, red, covered with lilac bloom; juicy, pulpy, sweet, somewhat astringent, of good flavor. A fair grape for the table, and makes a good wine, resembling Hock, but subject to mildew, rot and leaf-blight. DIANA. A seedling of the foregoing, raised by Mrs. DIANA CREHORE. Perhaps one of the most variable of all the grapes, being very fine one season, and very indifferent the next. Bunch large and long, compact, shouldered; berry pale red, round, somewhat pulpy; thick skin; juicy and sweet, with a peculiar flavor, which DR. WARDER very aptly calls "feline;" others call it "delicate." Very productive, but subject to leaf-blight, mildew and rot; although perhaps not so much as the Catawba. Ripens about a week earlier. ISABELLA. Unworthy of cultivation here, but said to be better at the North. Bunch long, loose, shouldered; berry medium, oval, black; tough pulp, with a good deal of acidity, juicy, and a peculiar flavor. Ripens irregularly. Subject to rot and leaf-blight. GARRIGUES. Closely resembling the Isabella, but ripens more evenly, and is of somewhat better quality. TOKALON. Bunch large, loose, shouldered; berry black, large, sweet and buttery; of very good quality, but very much subject to disease. Ripens somewhat later than Catawba. ANNA. Bunch large and loose; berry pale amber, covered with white bloom; sweet, tolerable flavor, but poor bearer, and subject to mildew. Ripens about same time as Catawba. ALLEN'S HYBRID, (ALLEN'S WHITE HYBRID). Bunch large and loose, shouldered; berry medium, nearly round; white, without pulp, juicy and delicious; quality very good, but variable; sometimes best. Said to be a hybrid of Vitis Labrusca and a foreign grape, raised by J. F. ALLEN, Salem, Massachusetts, and is really a fine grape, although too tender and variable for extensive vineyard culture. Ripens about two weeks before Catawba. CUYAHOGA (COLEMAN'S WHITE). Much recommended in Ohio, where it originated, but unworthy of culture here, being a poor grower, a shy bearer and very much subject to leaf-blight. Bunch medium, compact; berry dirty greenish-white; thick skin; pulpy, and insipid. DEVEREAUX. This is, in dry seasons, a really fine grape, but subject to leaf-blight and mildew in hot seasons. Bunch often a foot long, loose, shouldered; berry below medium, round, black, juicy; without pulp, sweet and vinous. Belonging to the Herbemont family; is a strong grower; very productive, and rather tender. May be valuable in well drained soils, and southern climate, as it undoubtedly will make a fine wine. KINGSESSING. Bunch long and loose, large, shouldered; berry medium, round, pale red, with fine lilac bloom; pulpy; of fair quality, but subject to leaf-blight, and mildew. ROGERS' HYBRID, NO. 15. Bunch large, loose, shouldered; berry above medium, red with blue bloom, roundish-oblong, pulpy, with peculiar flavor, sweet and juicy. A showy grape, but not very good in quality, and much subject to mildew and rot. Ripens at the same time with Catawba. CLASS 5.--_Varieties unworthy of cultivation._ OPORTO. Of all the humbugs ever perpetrated upon the grape-growing public, this is one of the most glaring. The vine, although a rank and healthy grower, is unproductive; seldom setting more than half a dozen berries on a bunch, and these are so sour, have such a hard pulp, with such a decided frost-grape taste and flavor, and are so deficient in juice, that no sensible man should think of making them into wine, much less call it, as its disseminator did, "the true port wine grape." MASSACHUSETTS WHITE. This was sent me some eight years ago, by B. M. WATSON, as "the best and hardiest white grape in cultivation," and he charged me the moderate sum of $5 each, for small pot plants, with hardly two eyes of ripened wood. After careful nursing of three years, I had the pleasure of seeing my labors rewarded by a moderate crop of the vilest _red_ Fox Grapes it has ever been my ill luck to try. The foregoing have all been tried by me, and have been characterized and classified as I have found them _here_. The following are varieties I have not fruited yet, although I have them on trial. Varieties highly recommended by good authorities: Telegraph, Black Hawk, Rogers' Hybrids, Nos. 3, 4, 6, 9, 12, 13, 19, 22, 33, Hettie, Lydia, Charlotte, Mottled, Pauline, Wilmington, Cotaction and Miles. There are innumerable other varieties, for which their originators all claim peculiar merits, and some of whom may prove valuable. But all who bring new varieties before the public, should consider that we have already names enough, nay, more than are good for us, and that it is useless to swell the list still more, unless we can do so with a variety, superior in some respects to our best varieties. A new grape, to claim favor at the hands of the public, should be healthy, hardy, a good grower, and productive; and of superior quality, either for the table or for wine. There are some varieties circulated throughout the country as natives, which are really nothing but foreign varieties, or, perhaps, raised from foreign seed. They will not succeed in open air, although now and then they will ripen a bunch. The Brinkle, Canadian Chief, Child's Superb, and El Paso belong to this class. A really good _table_ grape should have a large amount of sugar, but tempered and made more agreeable by a due proportion of acid, as, if the acid is wanting, it will taste insipid; a tender pulp, agreeable flavor, a large amount of juice, a good sized bunch, large berry, small seeds, thin skin, and hang well to the bunch. A good _wine_ grape should have a large amount of sugar, with the acid in due proportion, a distinctive flavor or aroma; though not so strong as to become disagreeable, and for red wines a certain amount of astringency. It is an old vintner's rule, that the varieties with small berries will generally make the best wine, as they are generally richer in sugar, and have more character than varieties with larger berries. [Illustration: FIG. 28. CLARA.--_Berries 1/2 diameter._] WINE-MAKING. GATHERING THE GRAPES. Although I have described the process already, I will here again reiterate that the grapes should be thoroughly _ripe_. This does not simply mean that they are well colored. The Concord generally begins to color here the 5th of August, and we could gather the majority of our grapes, of that variety, for market, by the 15th or 20th of that month; but for wine-making we allow them to hang until the 15th or 20th of September, and sometimes into October. Thus only do we get the full amount of sugar and delicacy of aroma which that grape is capable of developing, as the water evaporates, and the sugar remains; it also loses nearly all the acidity from its pulp; and the latter, which is so tough and hard immediately after coloring, nearly all dissolves and becomes tender. The best evidences of a grape being thoroughly ripe are: 1st. The stem turns brown, and begins to shrivel; 2nd, the berry begins to shrivel around the stem; 3d, thin and transparent skin; 4th, the juice becomes very sweet, and sticks to the finger like honey or molasses, after handling the grapes for some time. It is often the case that some bunches ripen much later on the vines. In such a case, the ripest should be gathered first, and those that are not fully ripe remain on the vines until mature. They will ripen much quicker if the ripest bunches have been removed first. The first implements needed for the gathering are clean wooden and tin pails and sharp knives, or better still, the small shears spoken of in a former part of this work. Each gatherer is provided with a pail, or two may go together, having a pail each, so that one can empty and the other keep filling during the time. If there are a good many unripe berries on the bunches, they may be put into a separate pail, and all that are soft will give an inferior wine. The bunch is cut with as short a stem as possible, as the stem contains a great deal of acid and astringency; every unripe or decayed berry is picked out, so that nothing but perfectly sound, ripe berries remain. [Illustration: FIG. 29.] The next implement that we need is a wooden tub or vat, to carry the grapes to the mill; or the wagon, if the vineyard is any distance from the cellar. This is made of thin boards, half-inch pine lumber generally; 3 feet high inside, 10 inches wide at the bottom, 20 inches wide at the top, being flat on one side, where it is carried on the back, and bound with thin iron hoops. It is carried by two leather-straps running over the shoulders, as shown in Fig. 29, and should contain about eight to ten pails, or a little over two bushels of grapes. The carrier can pass easily through the rows with it to any part of the vineyard, and lean it against a post until full. If the vineyard is close to the cellar or press-house, the grapes can be carried to it directly; if too far, we must provide a long tub or vat, to place on the wagon, into which the grapes are emptied. I will here again repeat that the utmost cleanliness should be observed in _all_ the apparatus; and no tub or vat should be used that is in the least degree mouldy. Everything should be perfectly sweet and clean, and a strict supervision kept up, that the laborers do not drop any crumbs of bread, &c., among the grapes, as this will immediately cause acetous fermentation. The weather should be dry and fair, and the grapes dry when gathered. THE WINE-CELLAR. As the wine-cellar and press-house are generally built together, I will also describe them together. A good cellar should keep about an even temperature in cold and warm weather, and should, therefore, be built sufficiently deep, arched over with stone, well ventilated, and kept dry. Where the ground is hilly, a northern or northwestern slope should be chosen, as it is a great convenience, if the entrance can be made even with the ground. Its size depends, of course, upon the quantity of wine to be stored. I will here give the dimensions of one I am constructing at present, and which is calculated to store from 15,000 to 20,000 gallons of wine. The principal cellar will be 100 feet long, by 18-1/2 feet wide inside, and 12 feet high under the middle of the arch. This will be divided into two compartments; the back one, at the farthest end of the cellar, to be 40 feet, which is destined to keep old wine of former vintages; as it is the deepest below the ground, it will keep the coolest temperature. It is divided from the front compartment by a wall and doors, so that it can be shut off should it become necessary to heat the other, while the must is fermenting. The other compartment will be 60 feet long, and is intended for the new wine, as the temperature will be somewhat higher, and, therefore, better adapted to the fermentation of the must. This will be provided with a stove, so that the air can be warmed, if necessary, during fermentation. This will also be closed by folding doors, 5-1/2 feet wide. There will be about six ventilators, or air-flues, on each side of these two cellars, built in the wall, constructed somewhat like chimneys, commencing at the bottom, whose upper terminus is about two feet above the arch, and closed with a grate and trap-doors, so that they can be closed and opened at will, to admit air and light. Before this principal cellar is an arched entrance, twenty feet long inside, also closed by folding doors, and as wide as the principal cellar. This will be very convenient to store empty casks, and can also be used as a fermenting room in Fall, should it be needed. The arch of the principal cellar will be covered with about six feet of earth; the walls of the cellar to be two feet thick. The press-house will be built above the cellar, over its entire length, and will also be divided into two rooms. The part farthest from the entrance of the cellar, to be 60 feet by 18, will be the press-house proper, with folding doors on both sides, about the middle of the building, and even with the surface ground, so that a wagon can pass in on one side and out on the other. This will contain the grape-mill, wine-presses, apparatus for stemming, and fermenting vats for white or light-colored wine. The other part, 40 feet long, will contain an apparatus for distilling, the casks and vats to store the husks for distilling, and the vats to ferment very dark colored wines on the husks, should it be necessary. It will also be used as a shop, contain a stove, and be floored, so that it will be convenient, in wet and cold weather, to cut cuttings, &c. A large cistern, to be built on one side of the building, so that the necessary water for cleaning casks, &c., will be handy; with a force-pump, will complete the arrangement. I need hardly add here, that the whole cellar should be paved with flags or brick, and well drained, so that it will be perfectly dry. This cellar is destined to hold two rows of casks, five feet long, on each side. For this purpose layers of strong beams are provided, upon which the casks are laid in such a manner that they are about two feet from the ground, fronting to the middle, and at least a foot or eighteen inches of space allowed between them and the wall, so that a man can conveniently pass and examine them. This will leave five and a-half to six feet of space between the two rows, to draw off the wine, move casks, _&c_. This cellar will, at the present rates of work, cost about $6,000. Of course, the cellar, as before remarked, can be built according to the wants of the grape-grower. For merely keeping wine during the first winter, a common house cellar will do; but during the hot days of summer wine will not keep well in it. APPARATUS FOR WINE-MAKING.--THE GRAPE MILL AND PRESS. This mill can be made very simple, of two wooden rollers, fastened in a square frame, running against each other, and turned with a crank and cog-wheel. The rollers should be about nine inches in diameter, and set far enough apart to mash the berries, but not the seeds and stems. A very convenient apparatus, mill and press, is manufactured by Geiss & Brosius, Belleville, Ill., and where the quantity to be made does not exceed 2,000 gallons, it will answer every purpose. The mill has stone rollers, which can be set by screws to the proper distance, with a cutting apparatus on top, for apples in making cider, which can be taken off at will. The press is by itself, and consists of an iron screw, coming up through the platform, with a zinc tube around it to prevent the must from coming in contact with it. The platform has a double bottom, the lower one with grooves; the upper consists simply of boards, with grooves through it to allow the must to run through. These boards are held in their places by wooden pegs, and can be taken off at will. A circular hopper, about a foot in diameter, and made of laths screwed to iron rings, with about a quarter of an inch space between them, encloses the zinc tube. The outer frame is constructed in the same way, is about 2-1/2 feet in diameter, and bound with strong wooden and iron hoops. The mashed grapes are poured into the frame, a close-fitting cover is put on, which is held down by a strong block, and the power is applied by an iron nut just on the top of the screw, with holes in each end to apply strong wooden levers. The apparatus is strong, simple, and convenient, and presses remarkably fast and clean, as the must can run off below, on the outside and also on the inside. The cost of mill and press is about $90, but each can be had separately for $45. If a large amount of grapes are to be pressed, the press should be of much larger dimensions, but may be constructed on the same principle--a strong, large platform, with a strong screw coming through the middle, and a frame made of laths, screwed to a strong wooden frame, through which the must can run off freely, with another frame around the outside of the platform. The must runs off through grooves to the lower side, where it is let off by a spout. It may be large enough to contain a hundred bushels of grapes at a single pressing, for a great deal depends upon the ability of the vintner to press a large amount just at the proper time, when the must has fermented on the husks just as long as he desires it to do. FERMENTING VATS. These should correspond somewhat with the size of the casks we intend to fill; but they are somewhat unhandy if they hold more than, say four hundred gallons. They are made of oak or white pine boards, 1-1/2 inch thick, bound securely by iron hoops, about three feet high, and, say, five feet wide. The bottom and inside must be worked clean and smooth, to facilitate washing. When the must is to ferment a longer time on the husks, as is often the case in red wines, a false bottom should be provided, for the purpose of holding the husks down below the surface of the must. It is made to fit the size of the vat, and perforated with holes, and held in its place by sticks of two inches square, let into the bottom of the vat, and which go through the false bottom. A hole is bored through them, and the bottom held down by means of a peg passed through this hole. The vat is closed by a tight-fitting cover, through which a hole is bored, large enough to admit a tin tube of about an inch in diameter, to let off the gas. The vats are set high enough above the ground to admit drawing off the must through a faucet near the bottom of the vat. For those grapes which are to be pressed immediately we need no false bottoms or covers for the vats. As fermentation generally progresses very rapidly here, and it is not desirable with most of our wines to ferment them on the husks very long, as they generally have astringency enough, operations here are much more simple than in Europe. The must is generally allowed to run into a large funnel, filled with oat straw, and passes through a hose into the casks in the cellar. A hole can be left through the arch for that purpose, as it is much more convenient than to carry the must in buckets from the press into the casks. It is sometimes desirable to stem the grapes, although it is seldom practiced in this country. This can be easily done by passing the bunches rapidly over a grooved board, made somewhat in the form of a common washboard, only the grooves should be round at the bottom and the edges on top. It is seldom desirable here. THE WINE CASKS. These should be made of well-seasoned white oak staves, and can, of course, be of various sizes to meet the wants of the vintner. The best and most convenient size for cellar use I have found to be about 500 gallons. These are sufficiently large to develop the wine fully, and yet can be filled quick enough to not interrupt fermentation. Of course, the vintner must have some of all sizes, even down to the five-gallon keg; but for keeping wine, a cask of 500 gallons takes less room comparatively, and the wine will attain a higher degree of perfection than in smaller casks. The staves to make such a cask should be about 5 feet long, and 1-1/2 to 2 inches thick, and be the very best wood to be had. The cask will, when ready, be about as high as it is long, should be carefully worked and planed inside, to facilitate washing and have a so-called door on one end, 12 inches wide and 18 inches high, which is fastened by means of an iron bolt and screw, and a strong bar of wood. This is to facilitate cleaning; when a cask is empty, the door is taken out, and a man slips into the cask with a broom and brush, and carefully washes off all remnants of lees, etc., which, as the lees of the wine are very slimy and tenacious, cannot be removed by merely pouring in water and shaking it about. It is also much more convenient to let these large casks remain in their places, than to move them about. The casks are bound with strong iron hoops. To prepare the new casks, and also the vats, etc., for the reception of the must, they should be either filled with pure water, and allowed to soak for several days, to draw out the tannin; then emptied, scalded with hot water, and afterwards steamed with, say two or three gallons of boiling wine; or they can be made "wine-green," by putting in about half a bushel of unslaked lime, and pouring in about the same quantity of hot water. After the lime has fallen apart, add about two quarts of water to each pound of lime, put in the bung, and turn the cask about; leaving it lie sometimes on one side, sometimes on the other, so that the lime will come in contact with every part of the cask. Then pour out the lime-water; wash once or twice with warm water, and rinse with a decoction of vine leaves, or with warm wine. Then rinse once more with cold water, and it will be fully prepared to receive the must. This is also to be observed with old casks, which have become, by neglect or otherwise, mouldy, or have a peculiar tang. MAKING THE WINE. As we have our apparatus all prepared now, we can commence the operation itself. This can be done in different ways, according to the class of wine we are about to make. To make white, or light-colored wine, the grapes which were gathered and mashed during the day, can be pressed and put into the cask the following night. To mash them, we place the mill above one of the fermenting vats, mashing them as quick as they are carried or hauled to the press-house. The vat is simply covered with a cloth during the day. If the season has been good, the must will make good wine without the addition of anything else. In poor seasons it will be necessary to add water and sugar, to improve its quality, but I will speak of this method in a separate chapter. In the evening, the must which will run off, is first drawn from the vat, and by some kept separate; but I think, it makes, upon the whole, a better wine, if the pressing is added to it. The husks, or mashed grapes, are then poured upon the press, and pressed until fully dry. To accomplish this the press is opened several times, and the edges of the cake, or "cheese," as some call it, are cut off with an axe or cleaver and put on top, after which they are pressed down again. The casks are then filled with the must; either completely, if it is intended that the must should ferment _above_, as it is called, or _under_, when the cask is not completely filled, so that the husks, which the must will throw up, will remain in the cask. Both methods have their advantages, but I prefer the former, with a very simple contrivance, to exclude the air, and also prevent waste. This is a siphon or tin tube, bent in the form of a double elbow, of which one end fits tightly in the bung hole, and the other empties into a dish of water, to be set on one end of the cask, through which the gas escapes, as shown in Fig. 30. We should, however in pressing, be guided somewhat by the weather. In warm weather fermentation will commence much sooner, and be more violent, than when the weather is cold. Consequently we should press much sooner in warm weather, than when the air is cool. Late in the fall, it is sometimes advisable to leave the must a day longer on the husks, than indicated below. The cellar should be kept at an even temperature of about 60° during the first few weeks, and if it does not naturally attain this temperature, then it should be warmed by a stove, as much of the quality of the wine depends upon a thorough fermentation during the first ten days. [Illustration: FIG. 30.] When violent fermentation has ceased, say after about ten or twelve days, and the must has become quiet, the cask should be closed with a tight bung, and the wine is left until it is clear. In about two to three months it ought to be perfectly clear and fine--is then racked, _i.e._, drawn from the lees, by means of a faucet, and put into clean, sweet casks. It is very important that the casks are "wine-seasoned," that is, have no other tang than of wine. For must, fresh brandy or whiskey casks may be used, but after the wine has fermented, it will not do to use such, as the wine will acquire the smell and taste of the liquor. When a cask has been emptied, it should be carefully cleaned, as before described, by entering at the door, or with smaller casks, by taking out the head. After it is thoroughly cleansed, it may be fumigated slightly, by burning a small piece of sulphured paper, or a nutmeg in it, and then filled. To keep empty casks in good condition they should, after cleaning, be allowed to become thoroughly dry, when they are sulphured, closed tightly, and laid away in the cellar. The operation of sulphuring should be repeated every six weeks. If wanted for use, they are simply rinsed with cold water. [Illustration: FIG. 31.] For racking the wine, we should have: 1st a large brass faucet. 2d. Pails of a peculiar shape, wider at the top, to prevent wastage. 3d. A wooden funnel, as shown in Fig. 31, to hold about six gallons. In racking--first carefully lift the bung of the cask, as the exclusion of air from above would cause a gurgling motion in the cask, if tapped below, which would stir up the lees in the bottom. Then, after having loosened with a hammer the wooden peg, closing the tap hole, let your assistant hold the pail opposite the hole, hold the faucet in your right hand, and with the left, withdraw the plug, inserting the faucet quickly. Drive it in firmly with a hammer, and you are ready for the work. Do not fully open the faucet at first, because the first pailful is generally not quite clear, and should run slowly. You can keep this by itself; and this, and the last from the lees, is generally put into a cask together and allowed to settle again. It will make a good, clear wine after a few weeks. As soon as the wine runs quite clear and limpid, it can be put into the cask destined to receive it, and you can let it run as fast as it can be emptied. When the wine has run off down to the tap hole, the cask may be carefully raised on the other end, one inserting a brick or piece of board under it, while the other lifts gently and slowly. This may be repeated several times, as long as the wine runs clear; and even the somewhat cloudy wine may be put with the first pailful into a separate cask. As soon as it comes thick or muddy, it is time to stop. The lees are emptied out, and will, if distilled, make a fine flavored and very strong brandy. This treatment can be applied to all white and light-colored wines, when it is not desirable to have a certain astringency in the wine. The Catawba, Concord, Herbemont, Delaware, Rulander, Cassady, Taylor, Louisiana, Hartford Prolific, and Cunningham should all be treated in a similar manner. The Concord, although it will, under this treatment, make only a light red wine, of which the color can be changed to dark red by fermenting on the husks, is not desirable if treated in the latter manner; as the peculiar foxy aroma of the grape will be imparted to the must to such a degree, as to make the flavor disagreeable, I shall recur to the subject of flavor in wines in another chapter. To make red wine, the must should be fermented on the husks, as generally the darkest color is desired, and also, a certain astringency, which the wine will acquire principally from the seeds, skins, and stems of the grapes, which contain the tannin. The grapes are mashed, and put into the fermenting vat, of the kind described before, with false bottoms. After the vat is filled about three-fourths the false bottom is put on, the husks are pressed down by it, until they are covered about six inches by the must, and the cover put on. It is seldom desirable here to ferment longer than three days on the husks, if the weather is warm--in a temperature of 60°--two days will often be enough, as the wine will become too rough and astringent by an excessively long fermentation. Only experience will be the proper guide here, and also the individual taste. It will be generally time to press, when the must has changed its sweet taste, and acquired a somewhat rough and bitter one. Where it is desired to make a very dark colored wine, without too much astringency, the grapes should be stemmed, as most of the rough and bitter taste is in the stems; and it can then be fermented on the husks for six or eight days. In this manner the celebrated Burgundy wines are made; also most of the red wines of France and Germany. Many of them are even allowed to go through the whole process of fermentation, and the husks are filled into the cask with the must, through a door, made in the upper side of the cask; and it there remains, until the clear wine is drawn off. This is seldom desirable here, however, as our red wine grapes have sufficient astringency and color without this process. The treatment during fermentation, racking, etc., is precisely the same as with white wine, with only this difference, that the red wine is generally allowed to stay longer on the lees; for our object in making this class of wine is different than in making white, or so-called Schiller or light red wine. In white and light colored wines we desire smoothness and delicacy of bouquet and taste; in dark red wines, we desire astringency and body, as they are to be the so-called stomach or medical wines. It is therefore generally racked but once, in the latter part of February or March, and the white and light colored wines are racked in December or January, as soon as they have become clear--and again in March. We also use no sulphur in fumigating the casks, as it takes away the color to a certain extent. We generally do not use anything, but simply clean the casks well, in racking red wine. I will say a few words in regard to _under_ fermentation. If this method is to be followed, the casks are not filled, but enough space left to allow the wine to ferment, without throwing out lees and husks at the bung. The bung is then covered, by laying a sack filled with sand over it, and when fermentation is over--as well by this as by the other method--the casks are filled with must or wine, kept in a separate cask for the purpose. The casks should always be kept well filled, and must be looked over and filled every two or three weeks, as the wine will continually lose in quantity, by evaporation through the wood of the casks. The casks should be varnished or brushed over with linseed oil, as this will prevent evaporation to some extent. In wine making, and giving the wine its character, we can only be guided by practice and individual taste, as well as the prevailing taste of the consuming public. If the prevailing taste is for light colored, smooth and delicate wines, we can make them so, by pressing immediately, and racking soon, and frequently. If a dark colored, astringent wine is desired, we can ferment on the husks, and leave it on the lees a longer period. There is a medium course, in this as in everything else; and the intelligent vintner will soon find the rules which should guide him, by practice with different varieties. Among the wines to be treated as dark red, I will name Norton's Virginia, Cynthiana, Arkansas, and Clinton, and, I suppose, Ives' Seedling. It would be insulting to these noble wines to class with them the Oporto, which may make a very dark colored liquid, but no _wine_ worth the name, unless an immense quantity of sugar is added, and enough of water to dilute the peculiar vile aroma of that grape. AFTER TREATMENT OF THE WINE. Even if the wine was perfectly fine and clear, when drawn off, it will go through a second fermentation as soon as warm weather sets it--say in May or June. If the wine is clear and fine, however, the fermentation will be less violent, than if it is not so clear, as the lees, which the wine has never entirely deposited; act as they ferment. It is not safe or judicious, therefore, to bottle the wine _before_ this second fermentation is over. As soon as the wine has become perfectly clear and fine again--generally in August or September--it can be bottled. For bottling wine we need: 1st. clean bottles. 2d. good corks, which must first be scalded with hot water, to soften them, and draw out all impurities, and then soaked in cold water. 3d. a small funnel. 4th. a small faucet. 5th. a cork-press, of iron or wood. 6th. a light wooden mallet to drive in the corks. After the faucet has been inserted in the cask, fill your bottles so that there will be about an inch of room between the cork and the wine. Let them stand about five minutes before you drive in the cork, which should always be of rather full size, and made to fit by compressing it with the press at one end. Then drive in the cork with the mallet, and lay the bottles, either in sand on the cellar floor, or on a rack made for that purpose. They should be laid so that the wine covers the cork, to exclude all air. The greater bulk of the wine, however, if yet on hand; can be kept in casks. All the wine to be kept thus, should be racked once in about six months, and the casks kept well filled. Most of our native wines, however, are generally sold after the second racking in March, and a great many even as soon as clear--in January. DISEASES OF THE WINE AND THEIR REMEDIES. These will seldom occur, if the wine has been properly treated. Cases may arise, however, when it will become necessary to rack the wine, or fine it by artificial means. TREATMENT OF FLAT AND TURBID WINE. The cause of this is generally a want of Tannin. If the wine has a peculiar, flat, soft taste, and looks cloudy, this is generally the case. Draw the wine into another cask, which has been well sulphured, and add some pulverized tannin, which can be had in every drug store. The tannin may be dissolved in water--about an ounce to every two hundred gallons of wine--and the wine well stirred, by inserting a stick at the bung. Should it not have become clear after about three weeks, it should be fined. This can be done, by adding about an ounce of powdered gum-arabic to each forty gallons, and stirring the wine well when it has been poured in. Or, take some wine out of the casks--add to each forty gallons which it contains the whites of ten eggs, whipped to foam with the wine taken out--pour in the mixture again--stir up well, and bung up tight. After a week the wine will generally be clear, and should then be drawn off. USE OF THE HUSKS AND LEES. These should be distilled, and will make a very strong, fine flavored brandy. The husks are put into empty barrels or vats--stamped down close, and a cover of clay made over them, to exclude the air. They will thus undergo a fermentation, and be ready for distillation in about a month. They should be taken fresh from the press, however; for if they come into contact with the air, they will soon become sour and mouldy. The lees can be distilled immediately. Good fresh lees, from rather astringent wines are also an excellent remedy when the wine becomes flat, as before described. DR. GALL'S AND PETIOL'S METHOD OF WINE MAKING. The process of wine making before described, however, can only be applied in such seasons, and with such varieties of grapes, that contain all the necessary elements for a good wine in due proportion. For unfavorable seasons, with such varieties of grapes as are deficient in some of the principal ingredients, we must take a different course--follow a different method. To see our way clearly before us in this, let us first examine which are the constituent parts of must or grape juice. A chemical analysis of must, shows the following result: Grape juice contains sugar, water, free acids, tannin, gummy and mucous substances, coloring matter, fragrant or flavoring substances, (aroma bouquet). A good wine should contain all these ingredients in due proportion. If there is an excess of one, and a want of the other, the wine will lose in quality. Must, which contains all of these, in due proportion, we call _normal_ must, and only by determining the amount of sugar and acids in this so-called normal must, can we gain the knowledge how to improve such must, which does not contain the necessary proportion of each. The frequent occurrence of unfavorable seasons in Europe, when the grapes did not ripen fully, and were sadly deficient in sugar, set intelligent men to thinking how this defect could be remedied; and a grape crop, which was almost worthless, from its want of sugar, and its excess of acids, could be made to yield at least a fair article, instead of the sour and unsaleable article generally produced in such seasons. Among the foremost who experimented with this object in view I will here name CHAPTAL, PETIOL; but especially DR. LUDWIG GALL, who has at last reduced the whole science of wine-making to such a mathematical certainty, that we stand amazed only, that so simple a process should not have been discovered long ago. It is the old story of the egg of Columbus; but the poor vintners of Germany, and France, and we here, are none the less deeply indebted to those intelligent and persevering men for the incalculable benefits they have conferred upon us. The production of good wine is thus reduced to a mathematical certainty; although we cannot in a bad season, produce as high flavored and delicate wines, as in the best years, we can now always make a fair article, by following the simple rules laid down by DR. GALL. When this method was first introduced, it was calumniated and despised--called adulteration of wine, and even prohibited by the governments of Europe; but, DR. GALL fearlessly challenged his opponents to have his wines analyzed by the most eminent chemists; which was repeatedly done, and the results showed that they contained nothing but such ingredients which pure wine should contain; and since men like VON BABO, DOBEREINER and others have openly endorsed and recommended gallizing, prejudice is giving way before the light of scientific knowledge. [Illustration: FIG. 32.] But to determine the amount of sugar and acids contained in the must we need a few necessary implements. These are: THE MUST SCALE OR SACCHAROMETER. The most suitable one now in use is the _Oechsle's_ must scale, constructed on the principle that the instrument sinks the deeper into any fluid, the thinner it is, or the less sugar it contains. Fig. 32 shows this instrument, "which is generally made of silver, or German silver, although they are also made of glass. A, represents a hollow cylinder--best made of glass, filled with must to the brim, into which place the must scale B. It is composed of the hollow float _a_, which keeps it suspended in the fluid; of the weight _c_, for holding in a perpendicular position; and of the scale _e_ divided by small lines into from fifty to one hundred degrees. Before the gauge is placed in the must, draw it several times through the mouth, to moisten it--but allow no saliva to adhere to it. When the guage ceases to descend, note the degree to which it has sunk; after which press it down with the finger a few degrees further, and on its standing still again, the line to which the must reaches, indicates its so-called weight, expressed by degrees." The must should be weighed in an entirely fresh state, before it shows any sign of fermentation, and should be free from husks, and pure. This instrument, which is indispensable to every one who intends to make wine, can be obtained in nearly every large town, from the prominent opticians. JACOB BLATTNER, at St. Louis keeps them for sale. The saccharometer will indicate the amount of sugar in the must, and its use is so simple, that every one can soon become familiar with it. The next step in the improvement of wines was to determine the amount of acids the must contained, and this problem has also been successfully solved by the invention of the acidimeter: THE ACIDIMETER AND ITS USE. "The first instrument of this kind which came into general use, was one invented by DR. OTTO, and consists of a glass tube, from ten to twelve inches in length, half an inch in width, and closed at the lower end. Fig. 33 shows OTTO'S Acidimeter. "The tube is filled to the partition line _a_, with tincture of litmus. The must to be examined, before it has begun to ferment is then poured into the tube, until it reaches the line 0. The blue tincture of litmus, which would still be blue, if water had been added, is turned into rose-color by the action of the acids contained in the must. "If a solution of 1,369 per cent, of caustic ammonia is added to this red fluid, and the tube is turned around to effect the necessary mixture, keeping its mouth closed with the thumb, after the addition of more or less of the ammonical fluid, it will change into violet. This tinge indicates the saturation of the acids, and the height of the fluid in the tube now shows the quantity of acid in the must, by whole, half and fourth parts per cent. The lines marked 1, 2, 3, 4, indicate whole per cents.; the short intermediate lines, one-fourth per cents." [Illustration: FIG. 33.] When DR. GALL, shortly before the vintage of 1850, first publicly recommended the dilution of the acids, he was obliged to refer to this instrument, as already known, and everywhere at hand, which was at the same time cheap, and simple in its use. "It is true, however, that if must is examined by this instrument, the quantity of acids contained in it, is really somewhat larger than indicated by the instrument; because the acids contained in the must require for their saturation a weaker solution of ammonia than acetic acid." As however, OTTO'S acidimeter shows about one eighth of the acids less than the must actually contains, and about as much acids combined with earths is removed during fermentation, DR. GALL recommends that the quantity of acids be reduced to 6-1/2, or at most 7 thousandths of OTTO'S acidimeter, and the results have shown that this was about the right proportion; as the wines in which the acids were thus diluted were in favor with all consumers. "The acidimeter referred to was afterwards improved, by making the tube longer and more narrow, and dividing it into tenths of per cents, instead of fourths; thus dividing the whole above 0 into thousandths. But although by this improved acidimeter the quantity of acids could be ascertained with more nicety, there remained one defect, that in often turning the glass tube for mixing the fluids, some of the contents adhered to the thumb in closing its mouth. This defect was remedied in a new acidimeter, invented by Mr. GEISLER, who also invented the new vaporimeter for the determination of the quantity of alcohol contained in wine. It is based on the same principle as OTTO'S, but differs altogether in its construction. It is composed of three parts, all made of glass; the mixing bottle, Fig. 34; the Pipette, Fig. 35; and the burette, Fig 36. Besides, there should be ready three small glasses--one filled with tincture of litmus, the second with a solution of 1,369 per ammonia, and the third with the must or wine to be tested; also, a taller glass, or vessel, having its bottom covered with cotton, in which glass the burette, after it has been filled with the solution of ammonia, is to be placed in an upright position until wanted. [Illustration: FIG. 34.] [Illustration: FIG. 35.] [Illustration: FIG. 36.] "To use this instrument the must and the tincture of litmus, having first received the normal temperature of 14° Reaumer, are brought into the mixing bottle by means of the pipette, which is a hollow tube of glass, open on both ends. To fill it, place its lower end into the tincture or must, apply the mouth to the upper end, and by means of suction fill it with the tincture of litmus to above the line indicated at A. The opening of the top is then quickly closed with the thumb; by alternately raising the thumb, and pressing it down again, so much of the tincture is then allowed to flow back into the glass so as to lower the fluid to the line indicated at A. The remainder is then brought into the bottle, and the last drops forced out by blowing into the pipette. "In filling it with must, raise the fluid in the same way, until it comes up to the line indicated at B, and then empty into the mixing bottle. "The burette consists of two hollow tubes of glass. In filling it, hold the smaller tube with the right hand into the glass containing the solution of ammonia, apply the mouth to the larger one, and by drawing in the fluid the tube is filled exactly to the line indicated at 0 of the tube. "Holding the mixing bottle by the neck between the thumb and forefinger of the left hand, place the smaller tube of the burette into the mouth of the mixing bottle, which must be constantly shaken; let enough of the solution of ammonia be brought drop by drop, into the mixture in the bottle, till the red has been changed into the deep reddish blue of the purple onion. This is the sign of the proper saturation of the acids. To distinguish still better, turn the mixing bottle upside down, by closing its mouth with the thumb, and examine the color of the fluid in the tube-shaped neck of the bottle, and afterwards, should it be required, add another drop of the ammonia. Repeat this until the proper tone of color has been reached, neither red nor blue. After thus fixing the precise point of the saturation of the acids, the burette is held upright, and the quantity of the solution of ammonia consumed is accurately determined,--that is, to what line on the scale the burette has been emptied. The quantity of the solution so used corresponds with the quantity of acids contained in the must--the larger division lines opposite the numbers indicating the thousandths part, and the smaller lines or dots the ten thousandths part. "Until the eye has learned by practice to recognize the points of saturation by the tone of color, it can be proven by means of litmus paper. When the mixture in the bottle begins to turn blue, put in the end of a slip of litmus paper about half an inch deep, and then draw this end through your fingers, moistened with water. So long as the ends of the blue litmus paper become more or less reddened, the acids have not been completely saturated. Only when it remains blue, has the point of saturation been reached. "In examining _red_ must, the method should be modified as follows:--Instead of first filling the pipette with tincture of litmus, fill it with water to the line A, and transfer it into the bottle. After the quantity of must has been added, drop six-thousandths of the solution of ammonia into the mixture, constantly shaking it while dropping, then test it, and so on, until, after every further addition required with litmus paper, it is no longer reddened after having been wiped off." DR. GALL further gives the following directions, as a guide, to distinguish and determine the proportion of acids which a must should contain, to be still agreeable to the palate, and good: "Chemists distinguish the acid contained in the grape as the vinous, malic, grape, citric, tannic, gelatinous and para-citric acids. Whether all these are contained in the must, or which of them, is of small moment for us to know. For the practical wine-maker, it is sufficient to know, with full certainty, that, as the grape ripens, while the proportion of sugar increases, the quantity of acids continually diminishes; and hence, by leaving the grapes on the vines as long as possible, we have a double means of improving their products--the must or wine. "All wines, without exception, to be of good and of agreeable taste, must contain from 4-1/2 to 7 thousandths parts of free acids, and each must containing more than seven thousandths parts of free acids may be considered as having too little water and sugar in proportion to its quantity of acids. "In all wine-growing countries of Germany, for a number of years past, experience has proved that a corresponding addition of sugar and water is the means of converting the sourest must, not only into a good drinkable wine, but also into as good a wine as can be produced in favorable years, _except_ in that peculiar and delicate aroma found only in the must of well-ripened grapes, and which must and will always distinguish the wines made in the best seasons from those made in poor seasons. "The saccharometer and acidimeter, properly used, will give us the exact knowledge of what the must contains, and what it lacks; and we have the means at hand, by adding water, to reduce the acids to their proper proportion; and by adding sugar, to increase the amount of sugar the must should contain; in other words, we can change the poor must of indifferent seasons into the normal must of the best seasons in _everything_, _except_ its bouquet or aroma, thereby converting an unwholesome and disagreeable drink into an agreeable and healthy one." THE CHANGE OF THE MUST, BY FERMENTATION, INTO WINE. Let us glance for a few moments at this wonderful, simple, and yet so complicated process, to give a clearer insight into the functions which man has to perform to assist Nature, and have her work for him, to attain the desired end. I cannot put the matter in a better light for my readers than to quote again from DR. GALL. He says:--"To form a correct opinion of what may and can be done in the manufacture of wine, we must be thoroughly convinced that Nature, in her operations, has other objects in view than merely to serve man as his careful cook and butler. Had the highest object of the Creator, in the creation of the grape, been simply to combine in the juice of the fruit nothing but what is indispensable to the formation of that delicious beverage for the accommodation of man, it might have been still easier done for him by at once filling the berries with wine already made. But in the production of fruits, the first object of all is to provide for the propagation and preservation of the species. Each fruit contains the germ of a new plant, and a quantity of nutritious matter surrounding and developing that germ. The general belief is, that this nutritious matter, and even the peculiar combination in which it is found in the fruit, has been made directly for the immediate use of man. This, however, is a mistake. The nutritious matter of the grape, as in the apple, pear, or any similar product, is designed by Nature only to serve as the first nourishment of the future plant, the germ of which lies in it. There are thousands of fruits of no use whatever, and are even noxious to man, and there are thousands more which, before they can be used, must be divested of certain parts, necessary, indeed, to the nutrition of the future plant, but unfit, in its present state, for the use or nourishment of man. For instance, barley contains starch, mucilaginous sugar, gum, adhesive matter, vegetable albumen, phosphate of lime, oil, fibre and water. All these are necessary to the formation of roots, stalks, leaves, flowers and the new grain; but for the manufacture of beer, the brewer needs only the first three substances. The same rule applies to the grape. "In this use of the grape, all depends upon the judgment of man to select such of its parts as he wishes, and by his skill he adapts and applies them in the best manner for his purposes. In eating the grapes, he throws away the skins and seeds; for raisins, he evaporates the water, retaining only the solid parts, from which, when he uses them, he rejects their seeds. If he manufactures must, he lets the skins remain. In making wine, he sets free the carbonic acid contained in the must, and removes the lees, gum, tartar, and, in short, everything deposited during, and immediately after fermentation, as well as when it is put into casks and bottles. He not only removes from the wine its sediments, but watches the fermentation, and checks it as soon as its vinous fermentation is over, and the formation of vinegar about to begin. He refines his wine by an addition of foreign substances if necessary; he sulphurizes it; and, by one means or another, remedies its distempers. "The manufacture of wine is thus a many-sided art; and he who does not understand it, or knows not how to guide and direct the powers of Nature to his own purposes, may as well give up all hopes of success in it." So far DR. GALL; and to the intelligent and unbiased mind, the truth and force of these remarks will be apparent, without further extending or explaining them. How absurd, then, the blind ravings of those who talk about "natural" wines, and would condemn every addition of sugar and water to the must by man, when Nature has not fully done her part, as adulteration and fraud. Why, there is no such thing as a "natural wine;" for wine--good wine--is the product of art, and a manufacture from beginning to end. Would we not think that parent extremely cruel, as well as foolish, who would have her child without clothing, simply because Nature had allowed it to be born without it? Would not the child suffer and die, because its mother failed to aid Nature in her work, by clothing and feeding it when it is yet unable to feed and clothe itself? And yet, would not that wine-maker act equally foolish who has it within his power to remedy the deficiencies of Nature with such means as she herself supplies in good season, and which ought and would be in the must but for unfavorable circumstances, over which we have no control? Wine thus improved is just as pure as if the sugar and water had naturally been in the grapes in right proportions; just as beneficial to health; and only the fanatical "know-nothing" can call it adulterated. But the prejudices will disappear before the light of science and truth, however much ignorance may clamor against it. GALILEO, when forced to abjure publicly his great discovery of the motion of the earth around the sun as a heresy and lie, murmured between his teeth the celebrated words, "And yet it moves." It _did_ move; and the theory is now an acknowledged truth, with which every schoolboy is familiar. Thus will it be with improved wine-making. It will yet be followed, generally and universally, as sure as the public will learn to distinguish between good and poor wine. Let us now observe for a moment the change which fermentation makes in converting the must into wine. The nitrogeneous compounds--vegetable albumen, gluten--which are contained in the grape, and which are dissolved in the must as completely as the sugar, under certain circumstances turn into the fermenting principle, and so change the must into wine. This change is brought about by the fermenting substance coming into contact with the air, and receiving oxygen from it, in consequence of which it coagulates, and shows itself in the turbid state of must, or young wine. The coagulation of the lees takes place but gradually, and just in the degree the exhausted lees settle. The sugar gradually turns into alcohol. The acids partly remain as tartaric acid, are partly turned into ether, or settle with the lees, chrystallize, and adhere to the bottom of the casks. The etheric oil, or aroma, remains, and develops into bouquet; also the tannin, to a certain degree. The albumen and gluten principally settle, although a small portion of them remains in the wine. The coloring matter and extractive principle remain, but change somewhat by fermentation. Thus it is the must containing a large amount of sugar needs a longer time to become clear than that containing but a small portion of it; therefore, many southern wines retain a certain amount of sugar undecomposed, and they are called _sweet_, or liqueur wines; whereas, wines in which the whole of the sugar has been decomposed are called _sour_ or _dry_ wines. I have thought it necessary to be thus explicit to give my readers an insight into the general principles which should govern us in wine-making. I have quoted freely from the excellent work of DR. GALL. We will now see whether and how we can reduce it to practice. I will try and illustrate this by an example. NORMAL MUST. "Experiments continued for a number of years have proved that, in favorable seasons, grape juice contains, on the average, in 1,000 lbs.: Sugar, 240 lbs. Acids, 6 " Water, 754 " ----- 1,000 " This proportion would constitute what I call a normal must. But now we have an inferior season, and the must contains, instead of the above proportions, as follows: Sugar, 150 lbs. Acids, 9 " Water, 841 " ----- 1,000 " What must we do to bring such must to the condition of a normal must? This is the question thus arising. To solve it, we calculate thus: If, in six pounds of acids in a normal wine, 240 pounds of sugar appear, how much sugar is wanted for nine pounds of acids? Answer, 360 pounds. Our next question is: If, in six pounds of acids in a normal must, 754 pounds of water appear, how much water is required for nine pounds of acids? Answer, 1,131 pounds. As, therefore, the must which we intend to improve by neutralizing its acids, should contain 360 pounds of sugar, nine pounds of acids, and 1,131 pounds of water, but contains already 150 pounds of sugar, 9 pounds of acids, and 841 pounds of water, there remain to be added, 210 pounds of sugar, no acids, and 290 pounds of water. By ameliorating a quantity of 1,000 pounds must by 210 pounds sugar, and 290 pounds water, we obtain 1,500 pounds of must, consisting of the same properties as the normal must, which makes a first-class wine." This is wine-making, according to GALL'S method, in Europe. Now, let us see what we can do with it on American soil, and with American grapes. THE MUST OF AMERICAN GRAPES. If we examine the must of most of our American wine grapes closely, we find that they not only contain an excess of acids in inferior seasons, but also a superabundance of flavor or aroma, and of tannin and coloring matter. Especially of flavor, there is such an abundance that, were the quantity doubled by addition of sugar and water, there would still be an abundance; and with some varieties, such as the Concord, if fermented on the husks, it is so strong as to be disagreeable. We must, therefore, not only ameliorate the acid, but also the flavor and the astringency, of which the tannin is the principal cause. Therefore it is, that to us the knowledge of how to properly gallize our wines is still more important than to the European vintner, and the results which we can realize are yet more important. By a proper management, we can change must, which would otherwise make a disagreeable wine, into one in which everything is in its proper proportion, and which will delight the consumer, to whose fastidious taste if would otherwise have been repugnant. True, we have here a more congenial climate, and the grapes will generally ripen better, so that we can in most seasons produce a drinkable wine. But if we can increase the quantity, and at the same time improve the quality, there is certainly an inducement, which the practical business sense of our people will not fail to appreciate and make use of. There is, however, one difficulty in the way. I do not believe that the acidimeter can yet be obtained in the country, and we must import them direct from the manufacturers, DR. L. C. MARQUART, of Bonn, on the Rhine; or J. DIEHN, Frankfort-on-the-Main. However, this difficulty will soon be overcome; and, indeed, although it is impossible to practice gallizing without a saccharometer, we may get at the surplus of acids with tolerable certainty by the results shown by the saccharometer. To illustrate this, I will give an example: Last year was one of the most unfavorable seasons for the ripening of grapes we have ever had here, and especially the Catawba lost almost nine-tenths of its crop by mildew and rot; it also lost its leaves, and the result was, that the grapes did not ripen well. When gathering my grapes, upon weighing the must, I found that it ranged from 52° to 70°; whereas, in good seasons, Catawba must weighs from 80° to 95°. I now calculated thus: if normal must of Catawba should weigh at least 80°, and the must I have to deal with this season will weigh on an average only 60°, I must add to this must about 1/2 lb. of sugar to bring it up to 80°. But now I had the surplus acid to neutralize yet. To do this, I calculated thus: If, even in a normal Catawba must, or a must of the best seasons, there is yet an excess of acid, I can safely count on there being at least one-third too much acid in a must that weighs but 60°. I, therefore, added to every 100 gallons of must 40 gallons of soft water, in which I had first dissolved 80 lbs. of crushed sugar, which brought the water, when weighed after dissolving the sugar in it, up to 80°. Now, I had yet to add 50 lbs., or half a pound to each gallon of the original must, to bring _this_ up to 80°. I thus pressed, instead of 100 gallons, 150 gallons, from the same quantity of grapes; and the result was a wine, which every one who has tasted it has declared to be excellent Catawba. It has a brilliant pale yellow color, was perfectly clear 1st of January, and sold by me to the first one to whom I offered it, at a price which I have seldom realized for Catawba wine made in the best seasons, without addition of sugar or water. True, it has not as strong an aroma as the Catawba of our best seasons, nor has it as much astringency; but this latter I consider an advantage, and it still has abundant aroma to give it character. Another experiment I made with the Concord satisfied me, without question, that the must of this grape will always gain by an addition of water and sugar. I pressed several casks of the pure juice, which, as the Concord had held its leaves and ripened its fruit very well, contained sugar enough to make a fair wine, namely, 75°. This I generally pressed the day after gathering, and put into separate casks. I then took some must of the same weight, but to which I had added, to every 100 gallons, 50 gallons of water, in which I had diluted sugar until the water weighed 75°, or not quite two pounds of sugar to the gallon of water, pressed also after the expiration of the same time, and otherwise treated in the same manner. Both were treated exactly alike, racked at the same time; and the result is, that every one who tries the two wines, without knowing how they have been treated, prefers the gallized wine to the other--the pure juice of the grape. It is more delicate in flavor, has less acidity, and a more brilliant color than the first, the ungallized must. They are both excellent, but there is a difference in favor of the gallized wine. DR. GALL recommends grape sugar as the best to be used for the purpose. This is made from potato starch; but it is hard to obtain here, and I have found crushed loaf sugar answer every purpose. I think this sugar has the advantage over grape sugar, that it dissolves more readily, and can even be dissolved in cold water, thus simplifying the process very much. It will take about two pounds to the gallon of water to bring this up to 80°, which will make a wine of sufficient body. The average price of sugar was about 22 cents per pound, and the cost of thus producing an additional gallon of wine, counting in labor, interest on capital, etc., will be about 60 cents. When the wine can be sold at from $2 to $3 per gallon, the reader will easily perceive of what immense advantage this method is to the grape-grower, if he can thereby not only improve the quality, but also increase the quantity of the yield. The efforts made by the Commissioner of Patents, and the contributors to the annual reports from the Patent Office, to diffuse a general knowledge of this process, can therefore not be commended too highly. It will help much to bring into general use, among all classes, good, pure, native wines; and as soon as ever the poorer classes can obtain cheap agreeable wines, the use of bad whiskey and brandy will be abandoned more and more, and this nation will become a more temperate people. But this is only the first step. There is a way to still further increase the quantity. DR. GALL and others found, by analyzing the husks of the grape after the juice had been extracted by powerful presses, that they not only still contained a considerable amount of juice, but also a great amount of extracts, or wine-making principles, in many instances sufficient for three times the bulk of the juice already expressed. This fact suggested the question: As there are so many of these valuable properties left, and only sugar and water exhausted, why cannot these be substituted until the others are completely exhausted? It was found that the husks still contained sufficient of acids, tannin, aroma, coloring matter, and gluten. All that remained to be added was water and sugar. It was found that this could be easily done; and the results showed that wine made in this manner was equal, if not superior, to some of that made from the original juice, and was often, by the best judges, preferred to that made from the original must. I have also practiced this method extensively the last season; and the result is, that I have fully doubled the amount of wine of the Norton's Virginia and Concord. I have thus made 2,500 gallons of Concord, where I had but 1,030 gallons of original must; and 2,600 gallons of Norton's Virginia, where I had but 1,300 gallons of must. The wines thus made were kept strictly separate from those made from the original juice, and the result is, that many of them are better, and none inferior, to the original must; and although I have kept a careful diary of wine-making, in which I have noted the process how each cask was made, period of fermentation on the husks, quantity of sugar used, etc., and have not hesitated to show this to every purchaser after he had tasted of the wine, they generally, and with very few exceptions, chose those which had either been gallized in part, or entirely. [Illustration: FIG. 37. UNION VILLAGE.--_Berries 1/3 diameter._] My method in making such wines was very simple. I generally took the same quantity of water, the husks had given original must, or in other words, when I had pressed 100 gallons of juice, I took about 80 gallons of water. To make Concord wine, I added 1-3/4 lbs. of sugar to the gallon, as I calculated upon some sugar remaining in the husks, which were not pressed entirely dry. This increased the quantity, with the juice yet contained in the husks to 100 gallons, and brought the water to 70; calculating that from 5° to 10° still remained in the husks, it would give us a must of about 80°. The grapes, as before remarked, had been gathered during the foregoing day, and were generally pressed in the morning. As soon as possible the husks were turned into the fermenting vat again, all pulled apart and broken, and the water added to them. As the fermentation had been very strong before, it immediately commenced again. I generally allowed them to ferment for twenty-four hours, and then pressed again, but pressed as dry as possible this time. The whole treatment of this must was precisely similar to that of the original. In making Norton's Virginia, I would take, instead of 1-3/4 lbs., 2 lbs. of sugar to the gallon--as it is naturally a wine of greater body than the Concord--and I aimed to come as near to the natural must as possible. I generally fermented this somewhat longer, as a darker color was desired. The time of fermentation must vary, of course, with the state of the atmosphere; in cooler weather, both pressings should remain longer on the husks. The results, in both varieties were wines of excellent flavor, good body, a brilliant color, with enough of tannin or astringency, and sufficient acid--therefore, in every way satisfactory. The experiments, however, were not confined to these alone, but extended over a number of varieties, with good results in every case. Of all varieties tried, however, I found that the Concord would bear the most of gallizing, without losing its own peculiar flavor; and I satisfied myself, that the quantity in this grape can safely be increased _here_, from 100 gallons of must to 250 gallons of wine, and the quality yet be better, than if the must had been left in its normal condition. And it is here again where only experience can teach us _how far_ we can go with a certain variety. It must be clear and apparent to any one who is ever so slightly acquainted with wine-making, how widely different the varieties are in their characteristics and ingredients. We may lay it down as a general rule, however, that our native grapes, with their strong and peculiar flavors, and their superabundance of tannin and coloring matter, will admit of much more gallizing, than the more delicately flavored European kinds. I have thus tried only to give an outline of the necessary operations, as well as the principles lying at the foundation of them. I have also spoken only of facts as I have found them, as I am well aware that this is a field in which I have much to learn yet, and where it but poorly becomes me to act the part of teacher. Those desiring more detailed information, I would refer to the Patent Office Reports of 1859-60, where they will find valuable extracts from the works of DR. GALL; and also to the original works. If we look at the probable effect these methods of improving wines are likely to have upon grape-culture, it is but natural that we should ask the question: Is there anything reprehensible in the practice--any reason why it should not become general? The answer to this is very simple. They contain nothing which the fermented grape juice, in its purest and most perfect state does not also contain. Therefore, they are as pure as any grape juice can be, with the consideration in their favor, that everything is in the right proportion. Therefore, if wine made from pure grape juice can be recommended for general use, surely, the gallized wines can also be recommended. DR. GALL has repeatedly offered to pay a fine for the benefit of the poor, if the most critical chemical analysis could detect anything in them, which was injurious to health, or which pure wines ought not to contain, and his opponents have always failed to show anything of the kind. I know that some of my wine-making friends will blame me for thus "letting the cat out of the bag." They seem to think that it would be better to keep the knowledge we have gained, to ourselves, carefully even hiding the fact that any of our wines have been gallized. But it has always been a deep-seated conviction with me, that knowledge and truth, like God's sun should be the common property of all His children--and that it is the duty of every one not to "hide his light under a bushel," but seek to impart it to all, who could, perhaps, be benefitted by it. And why, in reality, should we seek to keep as a secret a practice which is perfectly right and justifiable? If there is a prejudice against it, (and we know there is), this is not the way to combat it. Only by meeting it openly, and showing the fallacy of it, can we hope to convince the public, that there is nothing wrong about it. Truth and justice need never fear the light--they can only gain additional force from it. I do not even attempt to sell a cask of gallized wine, before the purchaser is made fully acquainted with the fact, that it has been gallized. It is a matter of course, that many, who go to work carelessly and slovenly, will fail to make good wine, in this or any other way. To make a good article, the nature of each variety and its peculiarities must be closely studied--we must have as ripe grapes as we can get, carefully gathered; and we need not think that water and sugar will accomplish _everything_. There is a limit to everything, and to gallizing as well as to anything else. As soon as we pass beyond that limit, an inferior product will be the result. But let us glance a moment at the probable influence this discovery will have on American grape culture. It cannot be otherwise than in the highest degree beneficial; for when we simply look at grape-culture as it was ten years ago, with the simple product of the Catawba as its basis; a variety which would only yield an average of, say 200 gallons to the acre--often very inferior wine--and look at it to-day, with such varieties as the Concord, yielding an average of from 1,000 to 1,500 gallons to the acre, which we can yet easily double by gallizing, thus in reality yielding an average of 2,500 gallons to the acre of uniformly good wine; can we be surprised if everybody talks and thinks of raising grapes? Truly, the time is not far distant--of which we hardly dared to dream ten years ago--and which we _then_ thought we would never live to see; when _every_ American citizen can indulge in a daily glass of that glorious gift of God to man, pure, light wine; and the American nation shall become a really _temperate_ people. And there is room for all. Let every one further the cause of grape-culture. The laborer by producing the grapes and wine; the mechanic by inventions; the law-giver by making laws furthering its culture, and the consumption of it; and _all_ by drinking wine, in wise moderation of course. WINE MAKING MADE EASY. Some of my readers may think I did not look much to this, which I told them was one of the objects of this little work. To vindicate it and myself I will here state, that our object should always be to attain the highest perfection in everything. But, while I am aware that I have generally given the outline of operations on a large scale, I have never for a moment lost sight of the interests of those, who, like myself, are compelled, by bitter necessity, to commence at the lowest round of the ladder. And how could I forget the bitter experience of my first years, when hindered by want of means; but also the feelings of sincere joy, of glad triumph, when I had surmounted one more obstacle, and saw the path open wider before me at every step; and I can, therefore, fully sympathize with the poor laborer, who has nothing but his industrious hands and honest will to commence with. While, therefore, it is most advantageous to follow grape-growing and wine-making with all the conveniences of well prepared soil, substantial trellis, a commodious wine cellar and all its appurtenances; yet, it is also possible to do without most of these conveniencies in the beginning, and yet succeed. If the grape-grower has not capital to spare to buy wire, he can, if he has timber on his land, split laths and nail them to the posts instead of wire. He can layer his plants even the first summer, and thus raise a stock for further planting; or dispose of them, as already mentioned in the beginning of this work. Or he can lease a piece of land from some one who wishes to have a vineyard planted on it, and who will furnish the plants to him, besides the necessary capital for the first year or so. I have contracted with several men without means in this manner, furnished them a small house, the necessary plants, and paid them $150 the first two years, they giving me half the returns of the vineyards, in plants and grapes; and they have become wealthy by such means. One of my tenants has realized over $8,000 for his share the last season, and will very likely realize the same amount next season. And if he cannot afford to build a large cellar in the beginning, he can also do with a small one, even the most common house cellar will do through the winter, if it is only kept free from frost. One of our most successful wine-growers here, commenced his operations with a simple hole in the ground, dug under his house, and his first wine press was merely a large beam, let into a tree, which acted as a lever upon the grapes, with a press-bed, also of his own making. A few weeks ago the same man sold his last year's crop of wine for over $9,000 in cash, and has raised some $2,000 worth more in vines, cuttings, etc. Of course, it is not advisable to keep the wine over summer in an indifferent cellar, but during fermentation and the greater part of winter, it will answer very well, and he can easily dispose of his wine, if good, as soon as clear. Or he can dispose of his grapes at a fair price, to one of his neighbors, or take them to market. But there is another consideration, which I cannot urge too strongly upon my readers, and which will do much to make grape-growing and wine-making easy. It is the forming of grape colonies, of grape-growers' villages. The advantages of such a colony will be easily seen. If each one has a small piece of suitable land, (and he does not need a large one to follow grape-growing), the neighbors can easily assist each other in ploughing and sub-soiling; they will be able to do with fewer work animals, as they can hitch together, and first prepare the soil for one and then for the other; the ravages of birds and insects will hardly be felt; they can join together, and build a large cellar in common, where each one can deliver and store his wine, and of which one perhaps better acquainted with the management of wine than the others, and whom all are willing to trust, can have the management. If there should be no such man among them, an experienced cooper can be hired by all, who can also manufacture the necessary casks. An association of that kind has also, generally, the preference in the market over a single individual, and they are able to obtain a higher price for their products, if they are of good quality. There are thousands upon thousands of acres of the best grape lands yet to be had in the West, especially in Missouri, at a merely nominal price, which would be well adapted for settlements of that kind; where the virgin soil yet waits only the bidding of intelligent labor--of enterprising and industrious men--to bring forth the richest fruits. There is room for all--may it soon be filled with willing hearts to undertake the task. And how much easier for you to-day, men with the active hand and intelligent brain, to commence--with the certainty of success before you--with varieties which will yield a large and sure return _every_ year; with the market open before you, and the experience of those who have commenced, to guide you; with the reputation of American wines established; with double the price per gallon--and ten times the yield--compared with the beginner of only ten years ago, with nothing but uncertainty; uncertainty of yield, uncertainty of quality, of price, and of effecting a sale. It took a brave heart _then_, and an iron will; the determination to succeed,--succeed against _all_ obstacles. And yet, hundreds have commenced thus, and have succeeded. Can _you_ hesitate, when the future is all bright before you, and the thousand and one obstacles have been overcome? If you do, you are not fit to be a grape-grower. Go toil and drudge for so many cents per day, in some factory, and end life as you have begun it. God's free air, the cultivation of one of His noblest gifts, destined to "make glad the heart in this rugged world of ours," is not for you. I may pity you, but I cannot sympathize with nor assist you, except by raising a cheap glass of wine to gladden even _your_ cheerless lot. [Illustration: FIG. 38. MAXATAWNY.--_Berries 1/2 diameter._] STATISTICS. COST OF ESTABLISHING A VINEYARD. In this, of course, allowances must be made for soil, locality, cost of plants, cost of timber, etc., which will vary with the locality. The estimation given here is about what it would cost _here_, with the leading varieties. COST OF AN ACRE OF CONCORD. Preparing ground by ploughing, laying off, etc., $ 50 00 700 first-class yearling plants, to be planted 6�10, $12 per hundred, 84 00 450 posts, 15 feet apart, 10 cents each, 45 00 450 intermediate stakes, 3 " 13 50 600 lbs. No. 12 wire, 16 cents per lb., 96 00 Cost of erecting trellis, 50 00 Attendance, labor, etc., during first year, 50 00 Interest on capital, 20 00 ------ $408 50 The following year the vineyard can be made to pay all expenses, by layering, etc. COST OF AN ACRE OF HERBEMONT. Preparing ground, 50 00 700 first class plants, 6�10, $25 per hundred, 175 00 450 posts, 10 cents each, 45 00 450 stakes, 3 " 13 50 600 lbs. wire, 16 cents per lb., 96 00 Cost of erecting trellis, 50 00 Attendance, labor, during first two years, 125 00 Interest on capital during first two years, 66 00 ------ $620 50 COST OF AN ACRE OF NORTON'S VIRGINIA. Preparation of soil, etc., 50 00 850 plants, first class, to be planted 6�8, $25 per hundred, 212 50 450 posts, 10 cents each, 45 00 450 stakes, 3 " 13 50 600 lbs. No. 12 wire, 16 cents per lb., 96 00 Cost of erecting trellis, 50 00 Attendance, labor, etc., during first two years, 125 00 Interest on capital during first two years, at 6 per cent. per annum, 70 00 ------ $662 00 COST OF AN ACRE OF DELAWARE. Cost of preparing ground, 50 00 1,200 first-class plants, planted 6�6, 400 00 450 posts, 10 cents each, 45 00 450 stakes, 3 " 13 50 600 lbs. No. 12 wire, 16 cents per lb. 96 00 Cost of erecting trellis, 50 00 Cost of cultivation two first years, 125 00 Interest on capital two years, 92 00 ------ $871 50 COST OF AN ACRE OF CATAWBA. Preparing ground, 50 00 Cost of 1,200 plants, 6�6, 45 00 450 posts, 10 cents each, 45 00 450 stakes, 3 " 13 50 600 lbs. wire, 16 cents per lb., 96 00 Cost of erecting trellis, 50 00 Attendance during two years, 125 00 Interest on capital two years, 39 00 ------ $463 50 PRODUCT. The following has been the produce of a vineyard of Catawba, now under my management, since 1849: Bearing Vines Gallons of Yield per season. bearing. Wine. Price. acre. 1849, 1st year, 1,500 750 $1.25 $600 00 1850, 2d " 2,000 150 1.25 95 00 1851, 3d " 2,000 500 1.25 300 00 1852, 4th " 1,800 210 1.25 120 00 1853. 5th " 1,500 580 1.25 500 00 1854, 6th " 2,500 750 1.50 600 00 1855, 7th " 3,000 230 2.00 150 00 1856 8th " 4,000 150 2.00 75 00 1857 9th " 4,000 2,000 1.20 600 00 1858, 10th " 4,000 210 1.20 60 00 1859, 11th " 4,200 1,200 1.20 360 00 1860, 12th " 4,200 1,300 1.25 405 00 1861, 13th " 4,200 150 1.00 37 50 1862, 14th " 4,200 20 2.00 10 00 1863, 15th " 4,200 150 2.00 75 00 1864, 16th " 4,200 150 2.00 75 00 1865, 17th " 4,200 500 2.00 250 00 Which will show the average yield per acre, to have been somewhat over 250 00 Deduct from this cost of labor per year, per acre, 50 00 Interest on capital, 40 00-90 00 Would leave a clear profit, per acre, of 160 00 The poor returns were nearly all occasioned by mildew and rot, with the exception of 1862, when a very destructive hail-storm swept away almost the entire crop; and in 1864, when the vines were all killed down to the snow line by frost the preceding winter. The following is the cost of a vineyard planted by me in May, 1861, containing about 3,000 vines, on 2-1/2 acres of ground. The ground could not be made ready until late in the season, consequently many of the vines failed to grow, and had to be replanted the second season: 1700 Norton's Virginia, $20.00 per hundred, 340 00 400 Concord (small), 25 " 100 00 350 Delaware, 50 " 175 00 150 Herbemont, 25 " 37 50 50 Cunningham, 50 " 25 00 Other varieties assorted, 100 00 Cost of clearing, ploughing, and planting, $50 per acre, 125 00 Putting up trellis, $150 per acre, 375 00 Interest on capital, 100 00 -------- $1,377 50 PRODUCT. For layers and cuttings made 1st year, 339 00 " " 2d " 1200 00 " " 3d " 2500 00 Concord grapes sold, 2,000 lbs., net 16 cents, 320 00 Plants and cuttings fourth year, 4000 00 2,040 lbs. of grapes (Concord), marketed at 24 cents per lb., net 489 60 -------- $8,848 60 PRODUCE FIFTH YEAR. 1,030 gallons Concord at $2.50 $2,575 00 1,300 " Norton's Virginia 4.00 5,200 00 125 " Herbemont 3.00 375 00 30 " Cunningham 4.00 120 00 40 " Delaware 6.00 240 00 10 " Clinton 3.00 30 00 50 " Other Varieties 3.00 150 00 336 " Hartford Prolific Grapes 20 cts. per lb. 67 20 57,000 Plants from cuttings and layers, average price $100 per thousand 5,700 00 --------- $14,457 20 Leaving the product of the first five years $23,305 80 From which deduct expenses for plants, trellis, etc., 1,277 Interest on capital at 5 per cent. 500 Cost of labor 1st. year, 150 2d. " 300 3d. " 400 4th. " 500 5th. " 500 ----- Total Cost $3,627 --------- Leaves clear profit for first five years of $19,679 80 The fourth year, nearly all the fruit buds of the vines had been killed above the snow line, but I made, besides the grapes sold, about $1,500 worth of wine, which was emptied by the rebels in their raid that fall, and consequently lost. The vines were not all in bearing this last season, for reasons already given; and the whole amount of vines bearing, was not more than 2,200--hardly two acres. If my readers will contrast this with the yield of the Catawba vineyard, they will see the difference in yield between varieties suited to the climate and soil, and those unused to it. The last season--although unfavorable to the Catawba--produced an enormous yield of Concord and Norton's Virginia, and cannot be taken as an average crop. I think about 700 gallons of Norton's Virginia, and 1,200 gallons of Concord would be a fair average estimate per year--which the vines can easily produce, and remain healthy and vigorous. YIELD OF MR. MICHAEL POESCHEL's VINEYARD.--CATAWBA. Year after planting. Acres in Vines. Yield. Price. 1847, 2d 5-6 24 gallons 2.00 1848, 3d 3-6 1,000 " 2.00 1849, 4th 2 600 " 1.50 1850, 5th 2 350 " 1.25 1851, 6th 2-1/2 450 " 1.75 1852, 7th 2-1/2 500 " 1.50 1853, 8th 2-1/2 350 " 2.00 1854, 9th 3-1/2 800 " 2.00 1855, 10th 3-1/2 50 " 1.50 1856, 11th 3-1/2 1,000 " 1.25 1857, 12th 6 4,500 " 1.50 1858, 13th 6 1,100 " 1.75 1859, 14th 6 1,500 " 1.50 1860, 15th 6 2,000 " 1.25 1861, 16th 6 250 " 1.00 1862, 17th 6 300 " 1.50 1863, 18th 8 2,000 " 1.15 NEW VINEYARD OF MR. MICHAEL POESCHEL, PLANTED IN 1861, 1863--FIRST PARTIAL CROP. 500 Gallons Norton's Virginia--2 acres, at $3 per gallon $1,500 00 Grapes sold from 1/2 acre of Concords 400 00 Plants from cuttings and layers sold 2,000 00 -------- $3,900 00 1864.--SECOND CROP.--VINES BADLY FROSTED IN WINTER. 2 Acres of Norton's Virginia produced 600 gallons, at $4 50 $2,700 00 2-1/2 Acres of Catawba, produced 400 gallons, at $2 15 850 00 Grapes sold from 1/2 acre of Concord 400 00 Plants sold 1,500 00 -------- $5,450 00 1865--THIRD CROP. 2-3/4 Acres of Norton's Virginia, produced 2,000 gallons at $4 8,000 00 2-1/2 Acres Catawba, produced 450 gallons at $1 75 787 50 1-1/4 Acres Concord, produced 1,000 gallons, at $250 2,500 00 1/2 acre Herbemont produced 400 gallons, at $3 per gallon, 1,200 00 1/2 acre Rulander produced 50 gallons, at $5 250 00 Plants sold, 1,500 00 --------- $14,237 50 This vineyard was trenched at an average cost of $120 dollars to the acre, and most of the vines are planted 5�5, evidently too close. They are trained to wire trellis, as described in a former part of this work, and receive close attention, and the very best cultivation. YIELD OF VINEYARD OF MR. WILLIAM POESCHEL--1857. 1-1/2 acres of Catawba produced 1,050 gallons of wine; sold at 1,402 50 1858. 1-3/4 acres of Catawba produced 250 gallons; sold at $1.10 per gallon, 275 00 1859. 1-3/4 acres Catawba produced 300 gallons; sold at $1.25 per gallon, 375 00 1860. 2 acres of Catawba produced 8,843 lbs. of grapes; sold at 10c. per lb., 884 30 120 gallons of wine, at $1.20 per gallon, 144 00 230 " 0.95 " 218 50 Plants sold, 600 00 -------- $1,846 80 1861. 2 acres of Catawba produced 270 gallons, at $1.05 per gallon, 283 50 Plants sold, 500 00 ------ $783 50 1862. 2 acres Catawba produced 6,718 lbs. of grapes; sold at 9 cents per lb., 604 62 225 gallons of wine, sold at $1.25 per gallon, 281 25 75 " of Norton's Virginia, from about 1-10th of an acre, at $2.75 per gallon, 206 25 Plants sold, 650 00 -------- $1,742 12 1863--2-1/4 ACRES IN ALL. 720 gallons of Catawba, at $1.85 per gallon, 1,332 00 60 " Concord, at $2.00 " 120 00 70 " Herbemont, at $2 " 140 00 40 " Norton's Virginia, $3 " 120 00 Plants sold, 800 00 -------- $2,512 00 1864--2-1/4 ACRES IN BEARING; VINES BADLY FROSTED. 45 gallons Catawba, $2.00 per gallon, 90 00 42 " Concord, 2.50 " 105 00 20 " Norton's Virginia and Delaware mixed, at $5.25 per gallon, 105 00 10 " Norton's Virginia, second class, at $3 30 00 Plants sold, 300 00 ------ $630 00 1865--5 ACRES IN BEARING. 2-1/2 acre Catawba produced 900 galls., at $1.75, 1,575 00 1/2 " Concord " 700 " 2.50, 1,750 00 1 " Norton's Vir. " 600 " 4.00, 2,400 00 1/3 " Delaware " 120 " 5.00, 600 00 1/2 " Herbemont " 350 " 2.50, 875 00 Balance in other varieties, 150 00 Plants sold, 940 00 -------- $8,290 00 This vineyard has one of the best locations for Catawba and Delaware in the neighborhood, and its proprietor one of the most intelligent and industrious cultivators and wine-manufacturers in the vicinity. The following are copied from the report of a special committee appointed by the Cincinnati Horticultural Society, to inquire into the condition of vineyards, and report whether or not grape-growing was still profitable. I regret to say that our Cincinnati friends have not, generally speaking, paid as much attention to the introduction and testing of better varieties--and there are but few vineyards in that neighborhood--where any other variety than the Catawba has been planted to any extent. It is to be hoped that the signal failure of that variety last season will do much to open their eyes to the full importance of the subject, and to abandon the Catawba, which evidently will not pay any longer. But, as we have already said, there are other varieties of grapes being successfully grown in this vicinity, and we have extended our researches to some of those vineyards, and give the results as follows:-- Ives' Seedling is a grape of much promise, not addicted to mildew and rot. Col. WAHRING, of Indian Hill, in this county, has a small vineyard, only two acres in bearing, which made, the past season, 650 gallons of wine. The season previous, only one acre in bearing, yielded 560 gallons. The Colonel makes his account for the past season's business stand as follows:-- 650 gallons of wine, sold at $4.10 per gallon, $2,665 00 Sale of cuttings, 1,500 00 -------- $4,165 00 Deduct cost of taking care of vineyard, 100 00 -------- Leaving net product of vineyard, $4,065 00 Or over $2,000 per acre. Norton's Virginia is another promising grape that is being grown considerably hereabouts. The Messrs. BOGEN have given us their figures for the product of this grape, as follows: 1863--From 1-1/2 acres, first year in bearing, they made 500 gallons, sold at $3 per gallon, $1,500 00 Sale of cuttings, 400 00 Sale of roots from layers, 800 00 -------- $2,700 00 Deduct from this, for cost of culture, 100 00 -------- Leaves net, $2,600 00 Or $1,733 per acre. 1864--Yield of same in wine and cuttings, 2,300 00 Or about $1,500 per acre. Delaware is another grape of very great promise and profit, now being extensively grown throughout the country. The Messrs. BOGEN, from one-third of an acre, first bearing year, give us the following figures for the past season: 87 gallons of wine, sold at $6 per gallon, 522 00 Sold cuttings, 450 00 Sold roots from layers, 2,050 00 -------- $3,022 00 Deduct cost of culture, 22 00 -------- $3,000 00 Or $9,000 per acre. Mr. J. E. MOTTIER gives us, as the result of his Delaware vineyard for the past two years, as follows: 1863--FROM 1-1/2 ACRES. 165 gallons of wine, sold at $5 per gallon, $825 00 Sale of cuttings, 1,630 00 -------- 2,455 00 Deduct expenses, 200 00 -------- Leaving net, $2,255 00 Or $1,504 per acre. 1864--FROM SAME VINEYARD. 200 gallons of wine, at $6 per gallon, $1,200 00 Sold roots from layers, 1,835 00 Sales of cuttings, 2,360 00 --------- 5,395 00 Deduct expenses, 200 00 -------- Leaves net, $5,195 00 Or $3,562 per acre Mr. MOTTIER says he might have obtained a larger yield of wine, but his vineyard being young, he would not allow it to overbear. Your committee, therefore, take pleasure in submitting the foregoing facts, in refutation, in part, of the loose and reckless statements of Mr. YEATMAN, and take this method of entering their protest against the same. (Signed), E. A. THOMPSON. JOHN E. MOTTIER. The foregoing contains some valuable facts, but it would seem to me that our Cincinnati friends have hardly estimated labor and expenses high enough. We cannot begin to cultivate our vineyards at as low an estimate. The following is a rough estimate of the last season's crop around Hermann. It may be rather inaccurate, but it is about as near as I could come to the result. There are now, I suppose, something like 1,000 acres planted in grapes, of which about 400 may be in bearing. Unfortunately, nearly all the old vineyards are planted with the Catawba, which was almost an entire failure this season, the average crop being only about 75 gallons to the acre. Most of the later planting has been done with the Concord and Norton's Virginia, but these vineyards are not bearing yet. Of the Norton's Virginia, the average crop the last season may have been about 600 gallons to the acre; of the Concord, 1,000 gallons per acre. The Herbemont may have yielded about 800 gallons to the acre. Grapes marketed, mostly Concord, 20,000 lbs. average price, 15c. per lb., $3,000 00 Catawba wine made, about 25,000 gallons; average value, $1.50 per gallon, 37,500 00 Norton's Virginia wine made, about 10,000 gallons; average value, $4 per gallon, 40,000 00 Concord wine made, about 5,000 gallons; average value, $2.50 per gallon, 12,500 00 Herbemont wine made, about 1,500 gallons; average value, $3 per gallon, 4,500 00 Other varieties made, about 1,000 gallons; average value, $3 per gallons, 3,000 00 Grape roots, cuttings, etc., grown and sold, 50,000 00 ---------- $150,500 00 I think the above is rather below the real amount; and the value of the crop may come up even as high as $200,000. Although grape culture is followed to a larger extent around Hermann than anywhere in the State, yet there are also a great many grapes grown and wine made around Boonville, in Cooper County; and Augusta, St. Charles County; also, Hannibal, on the Mississippi river; and St. Joseph, on the Missouri; and there is hardly a county in the State now but has some flourishing vineyards. The above facts may serve to give my readers a clearer insight into the cost and profits of grape-growing, and also the comparative varieties. In every case, the figures given can be relied on as actual facts. In our neighboring States, Illinois and Iowa, grape-growing is progressing rapidly. There are already a number of vineyards established in the neighborhood of Alton, Belleville, Mascoutah, Warsaw, and Nauvoo, in Illinois; and in the neighborhood of Burlington and Davenport, in Iowa. I am told that in the neighborhood of Makanda alone, in Jackson County, Illinois, at least 70,000 vines of the Concord will be planted the coming spring. Our sister State, Kansas, is also progressing bravely in the good work; and I do not think that, although our propagators throughout the country have done their best, there will be half the number of vines for sale that are wanted to meet the demand. But, while I am fully aware of the importance of grape-culture _everywhere_, I cannot help but believe that the southwest will take the preference in grape-growing over the eastern and northern States. We have the advantages of longer seasons and a warmer climate, generally of richer soil, of cheaper lands; we can cultivate varieties which cannot be grown by our eastern brethren, and therefore all the chances are on our side. The mountainous regions of Tennessee, Georgia, Arkansas, Texas, and Alabama may, perhaps, rival and even surpass us in the future, but their inhabitants at present are not of the clay from which grape-growers are formed. They still cling to the demon of slavery, and their hatred of northern industrious _freemen_ seems to be stronger than their love of prosperity. Let us hope that a better spirit may prevail, that they will in time begin to see their own interest, and welcome with open arms every one who can assist them in developing the natural advantages of their lands. The grape can only flourish on _free_ soil, and by _free_ intelligent labor. 
33165	----	produced from images generously made available by The Internet Archive.) COAL; AND WHAT WE GET FROM IT. THE ROMANCE OF SCIENCE. COAL AND WHAT WE GET FROM IT. A Romance of Applied Science. EXPANDED FROM THE NOTES OF A LECTURE DELIVERED IN THE THEATRE OF THE LONDON INSTITUTION, JAN. 20th, 1890. BY RAPHAEL MELDOLA, F.R.S., F.I.C., &C., PROFESSOR OF CHEMISTRY IN THE FINSBURY TECHNICAL COLLEGE, CITY AND GUILDS OF LONDON INSTITUTE. PUBLISHED UNDER THE DIRECTION OF THE COMMITTEE OF GENERAL LITERATURE AND EDUCATION APPOINTED BY THE SOCIETY FOR PROMOTING CHRISTIAN KNOWLEDGE. LONDON: SOCIETY FOR PROMOTING CHRISTIAN KNOWLEDGE, NORTHUMBERLAND AVENUE, CHARING CROSS, W.C.; 43, QUEEN VICTORIA STREET, E.C. BRIGHTON: 135, NORTH STREET. NEW YORK: E. & J. B. YOUNG & CO. 1891. TO WILLIAM HENRY PERKIN, PH.D., F.R.S., THE FOUNDER OF THE COAL-TAR COLOUR INDUSTRY, THIS BOOK IS DEDICATED BY THE AUTHOR. PREFACE. This is neither a technical manual, nor a treatise dealing with the history of a particular branch of applied science, but it partakes somewhat of the character of both. It is an attempt--perhaps somewhat bold--to present in a popular form an account of the great industry which has arisen out of the waste from the gas-works. In the strictest sense it is a romance of dirt. To render intelligible the various stages in the evolution of the industry, without assuming any knowledge of chemical science on the part of the general reader, has by no means been an easy task, and I have great misgivings as to the success of my effort. But there is so much misapprehension concerning the history and the mode of production of colouring-matters from coal-tar, that any attempt to strip the industry of its mystery in this, the land of its birth, cannot but find justification. Although the theme is a favourite one with popular lecturers, it is generally treated in a superficial way, leaving the audience only in possession of the bare fact that dyestuffs, &c., have by some means or other been obtained from coal-tar. I have endeavoured to go somewhat beyond this, and to give some notion of the scientific principles underlying the subject. If the reader can follow these pages, in which not a chemical formula appears, with the same interest and with the same desire to know more about the subject that was manifested by the audience at the London Institution, before whom the lecture was delivered, my object will have been accomplished. To the Board of Managers of that Institution my thanks are due for the opportunity which they have afforded me of attempting to extend that popular knowledge of applied science for which there is such a healthy craving in the public mind at the present time. R. M. _6 Brunswick Square, W.C._ CONTENTS. CHAPTER I. Origin of Coal, 9. Coal of various ages, 11. Graphite, 12. Recent Vegetable Deposits, 13. Mode of occurrence of Coal, 13. Structure of Coal, 15. Uses of Coal, 16. Coal a source of Energy, 17. Mechanical Equivalent of Heat, 19. Value of Coal as a Fuel, 20. Small efficiency of Steam-engines, 21. Mechanical value of Coal, 22. Whence Coal derives its Energy, 22. Chemical Composition of Coal, 23. Growth of Plants, 26. Solar Energy, 28. Transformation of Wood into Coal, 30. Destructive Distillation of Coal, 33. Experiments of Becher, 34; of Dean Clayton, 35; of Stephen Hales, 37; of Bishop Watson, 37; of the Earl of Dundonald, 39. Coal-gas introduced by Murdoch, 40. Spread of the new Illuminant, 41. Manufacture of Coal-gas, 42. Quantitative results, 45. Uses of Coke, 47. Goethe's visit to Stauf, 48. Bishop Watson on waste from Coke-ovens, 50. Shale-oil Industry, 50. History of Coal-mining, 57. Introduction of Coal into London, 58. The Coal resources of the United Kingdom, 60. Competition between Electricity and Coal-gas, 62. CHAPTER II. Ammoniacal Liquor of Gas-works, 64. Origin of the Ammonia, 65. Ammonia as a Fertilizer, 65. Other uses of Ammonia, 67. Annual production of Ammonia, 68. Utilization of Coal-tar, 69. The Creosoting of Timber, 70. Early uses of the Light Tar Oils, 71. Discovery of Benzene by Faraday; isolation from Tar Oil by Hofmann and Mansfield, 73. Discovery of Mauve by Perkin, 74. History of Aniline, 75. The Distillation of Coal-tar, 77. Separation of the Hydrocarbons of the Benzene Series, 82. Manufacture of Aniline and Toluidine, 87. History and Manufacture of Magenta, 89. Blue, Violet, and Green Dyes from Magenta, 92. The Triphenylmethane Group, 97. The Azines, 108. Lauth's Violet and Methylene Blue, 111. Aniline Black, 114. Introduction of Azo-dyes, 115. Aniline Yellow, Manchester Brown, and Chrysoïdine, 118. The Indulines, 121. Chronological Summary, 122. CHAPTER III. Natural Sources of Indigo, 124. Syntheses of the Colouring-matter, 126. Carbolic Oil, its treatment and its constituents, 129. Phenol Dyes, 132. Salicylic Acid and its uses, 134. Picric Acid, 136. Naphthalene and its applications, 139. The Albo-carbon Light, 140. Phthalic Acid and the Phthaleïns, 145. Magdala Red, 149. Azo-dyes from the Naphthols, Naphthylamines, and their Sulpho-acids, 150. Naphthol Green, the Oxazines, and the Indophenols, 161. Creosote Oil, 163. The Lucigen Burner, 163. Anthracene Oil, 167. The Discovery of Artificial Alizarin, and its effects on Madder growing, 167. The industrial isolation of Anthracene and its conversion into Colouring-matters, 171. Pitch, and its uses, 176. Patent Fuel, or Briquettes, 178. Coal-tar products in Pharmacy, 178. Aromatic Perfumes, 185. Coal-tar Saccharin, 186. Coal-tar Products in Photography, 188. Coal-tar Products in Biology, 192. Value of the Coal-tar Industry, 194. The Coal-tar Industry in relation to pure Science, 196. Permanence of the Artificial Colouring-matters, 198. Chronological Summary, 200. Addendum, 202. COAL; AND WHAT WE GET FROM IT. CHAPTER I. "Hier [1771] fand sich eine zusammenhängende Ofenreihe, wo Steinkohlen abgeschwefelt und zum Gebrauch bei Eisenwerken tauglich gemacht werden sollten; allein zu gleicher Zeit wollte man Oel und Harz auch zu Gute machen, ja sogar den Russ nicht missen, und so unterlag den vielfachen Absichten alles zusammen."--Goethe, _Wahrheit und Dichtung_, Book X. To get at the origin of the familiar fuel which blazes in our grates with such lavish waste of heat, and pollutes the atmosphere of our towns with its unconsumed particles, we must in imagination travel backwards through the course of time to a very remote period of the world's history. Ages before man, or the species of animals and plants which are contemporaneous with him, had appeared upon the globe, there flourished a vegetation not only remarkable for its luxuriance, but also for the circumstance that it consisted to a preponderating extent of non-flowering or cryptogamic plants. In swampy areas, such as the deltas at the mouths of great rivers, or in shallow lagoons bordering a coast margin, the jungles of ferns and tree-ferns, club-mosses and horse-tails, sedges, grasses, &c., grew and died down year by year, forming a consolidated mass of vegetable matter much in the same way that a peat bed or a mangrove swamp is accumulating organic deposits at the present time. In the course of geological change these beds of compressed vegetation became gradually depressed, so that marine or fresh-water sediment was deposited over them, and then once more the vegetation spread and flourished to furnish another accumulation of vegetable matter, which in its turn became submerged and buried under sediment, and so on in successive alternations of organic and sedimentary deposits. But these conditions of climate, and the distribution of land and water favourable to the accumulation of large deposits of vegetable matter, gradually gave way to a new order of things. The animals and plants adapted to the particular conditions of existence described above gave rise to descendants modified to meet the new conditions of life. Enormous thicknesses of other deposits were laid down over the beds of vegetable remains and their intercalated strata of clay, shale, sandstone, and limestone. The chapter of the earth's history thus sealed up and stowed away among her geological records relates to a period now known as the Carboniferous, because of the prevalence of seams or beds of coal throughout the formation at certain levels. By the slow process of chemical decomposition without access of air, modified also by the mechanical pressure of superincumbent formations, the vegetable deposits accumulated in the manner described have, in the lapse of ages, become transformed into the substance now familiar to us as coal. Although coal is thus essentially a product of Carboniferous age, it must not be concluded that this mineral is found in no other geological formation. The conditions favourable for the deposition of beds of vegetable matter have prevailed again and again, at various periods of geological time and on different parts of the earth, although there is at present no distinct evidence that such a luxuriant growth of vegetation, combined with the other necessary conditions, has ever existed at any other period in the history of the globe. Thus in the very oldest rocks of Canada and the northern States of America, in strata which take us back to the dawn of geological history, there is found abundance of the mineral graphite, the substance from which black-lead pencils are made, which is almost pure carbon. Now most geologists admit that graphite represents the carbon which formed part of the woody tissue of plants that lived during those remote times, so that this mineral represents coal in the ultimate stage of carbonization. In some few instances true coal has been found converted into graphite _in situ_ by the intrusion of veins of volcanic rock (basalt), so that the connection between the two minerals is more than a mere matter of surmise. Then again we have coal of pre-Carboniferous age in the Old Red Sandstone of Scotland, this being of course younger in point of time than the graphite of the Archæan rocks. Coal of post-Carboniferous date is found in beds of Permian age in Bavaria, of Triassic age in Germany, in the Inferior Oolite of Yorkshire belonging to the Jurassic period, and in the Lower Cretaceous deposits of north-western Germany. Coming down to more recent geological periods, we have a coal seam of over thirty feet in thickness in the northern Tyrol of Eocene age; we have brown coal deposits of Oligocene age in Belgium and Austria, and, most remarkable of all, coal has been found of Miocene, that is, mid-Tertiary age, in the Arctic regions of Greenland within a few degrees of the North Pole. Thus the formation of coal appears to have been going on in one area or another ever since vegetable life appeared on the globe, and in the peat bogs, delta jungles, and mangrove swamps of the present time we may be said to have the deposition of potential coal deposits for future ages now going on. Although in some parts of the world coal seams of pre-Carboniferous age often reach the dignity of workable thickness, the coal worked in this country is entirely of Carboniferous date. After the explanation of the mode of formation of coal which has been given, the phenomena presented by a section through any of our coal measures will be readily intelligible (see Fig. 1). We find seams of coal separated by beds of sandstone, limestone, or shale representing the encroachment of the sea and the deposition of marine or estuarine sediment over the beds of vegetable remains. The seams of coal, varying in thickness from a few inches to three or four feet, always rest on a bed of clay, known technically as the "underclay," which represents the soil on which the plants originally grew. In some instances the seams of coal with their thin "partings" of clay reach an aggregate thickness of twenty to thirty feet. In many cases the very roots of the trees are found upright in a fossilized condition in the underclay, and can be traced upwards into the overlying coal beds; or the completely carbonized trunk is found erect in the position in which the tree lived and died (see Fig. 2). [Illustration: FIG. 1.--Section through Carboniferous strata showing seams of coal. Dislocations, or "faults," so common in the Coal Measures, are shown at H, T, and F. Intrusions of igneous rock are shown at D. At B is shown the coalescence of two seams, and at N the local thinning of the seam. The vertical lines indicate the shafts of coal mines.] [Illustration: FIG. 2.--Section showing coal seams and upright trunks attached to roots _in situ_. A', A'', A''', beds of shale. B, coal seams. C, underclay. D, sandstone.] Owing to the chemical and mechanical forces to which the original vegetable deposit has been subjected, the organic structure of coal has for the most part been lost. Occasionally, however, portions of leaves, stems, and the structure of woody fibre can be detected, and thin sections often show the presence of spore-cases of club-mosses in such numbers that certain kinds of coal appear to be entirely composed of such remains. But although coal itself now furnishes but little direct evidence of its vegetable origin, the interstratified clays, shales, and other deposits often abound with fossilized plant remains in every state of preservation, from the most delicate fern frond to the prostrate tree trunk many yards in length. It is from such evidence that our knowledge of the Carboniferous flora has been chiefly derived. Now this carbonized vegetation of a past age, the history of which has been briefly sketched in the foregoing pages, is one of the chief sources of our industrial supremacy as a nation. We use it as fuel for generating the steam which drives our engines, or for the production of heat wherever heat is wanted. In metallurgical operations we consume enormous quantities of coal for extracting metals from their ores, this consumption being especially great in the case of iron smelting. For this last operation some kinds of raw coal are unsuitable, and such coal is converted into coke before being used in the blast furnace. The fact that the iron ore and the coal occur in the same district is another cause of our high rank as a manufacturing nation. It has often been a matter of wonder that iron ore and the material essential for extracting the metal from it should be found associated together, but it is most likely that this combination of circumstances, which has been so fortunate for our industrial prosperity, is not a mere matter of accident, but the result of cause and effect. It is, in fact, probable that the iron ore owes its origin to the reduction and precipitation of iron compounds by the decomposing vegetation of the Carboniferous period, and this would account for the occurrence of the bands of ironstone in the same deposits with the coal. In former times, when the area in the south-east of England known as the Weald was thickly wooded, the towns and villages of this district were the chief centres of the iron manufacture. The ore, which was of a different kind to that found in the coal-fields, was smelted by means of the charcoal obtained from the wood of the Wealden forests, and the manufacture lingered on in Kent, Sussex, and Surrey till late in the last century, the railings round St. Paul's, London, being made from the last of the Sussex iron. When the northern coal-fields came to be extensively worked, and ironstone was found so conveniently at hand, the Wealden iron manufacture declined, and in many places in the district we now find disused furnaces and heaps of buried slag as the last witnesses of an extinct industry. From coal we not only get mechanical work when we burn it to generate heat under a steam boiler, but we also get chemical work out of it when we employ it to reduce a metallic ore, or when we make use of it as a source of carbon in the manufacture of certain chemical products, such as the alkalies. We have therefore in coal a substance which supplies us with the power of doing work, either mechanical, chemical, or some other form, and anything which does this is said to be a source of energy. It is a familiar doctrine of modern science that energy, like matter, is indestructible. The different forms of energy can be converted into one another, such, for example, as chemical energy into heat or electricity, heat into mechanical work or electricity, electricity into heat, and so forth, but the relationship between these convertible forms is fixed and invariable. From a given quantity of chemical energy represented, let us say, by a certain weight of coal, we can get a certain fixed amount of heat and no more. We can employ that heat to work a steam-engine, which we can in turn use as a source of electricity by causing it to drive a dynamo-machine. Then this doctrine of science teaches us that our given weight of coal in burning evolves a quantity of heat which is the equivalent of the chemical energy which it contains, and that this quantity of heat has also its equivalent in mechanical work or in electricity. This great principle--known as the Conservation of Energy--has been gradually established by the joint labours of many philosophers from the time of Newton downwards, and foremost among these must be ranked the late James Prescott Joule, who was the first to measure accurately the exact amount of work corresponding to a given quantity of heat. In measuring heat (as distinguished from temperature) it is customary to take as a unit the quantity necessary to raise a given weight of water from one specified temperature to another. In measuring work, it is customary to take as a unit the amount necessary to raise a certain weight at a specified place to a certain height against the force of gravity at that place. Joule's unit of heat is the quantity necessary to raise one pound of water from 60° to 61° F., and his unit of work is the foot-pound, _i.e._ the quantity necessary to raise a weight of one pound to a height of one foot. Now the quantitative relationship between heat and work measured by Joule is expressed by saying that the mechanical equivalent of heat is about 772 foot-pounds, which means that the quantity of heat that would raise one pound of water 1° F. would, if converted into work, be capable of raising a one-pound weight to a height of 772 feet, or a weight of 772 lbs. to a height of one foot. This mechanical equivalent ought to tell us exactly how much power is obtainable from a certain weight of coal if we measure the quantity of heat given out when it is completely burnt. Thus an average Lancashire coal is said to have a calorific power of 13,890, which means that 1 lb. of such coal on complete combustion would raise 13,890 lbs. of water through a temperature of 1° F., if we could collect all the heat generated and apply it to this purpose. But if we express this quantity of heat in its mechanical equivalent, and suppose that we could get the corresponding quantity of work out of our pound of coal, we should be grievously mistaken. For in the first place, we could not collect all the heat given out, because a great deal is communicated to the products of combustion by which it is absorbed, and locked up in a form that renders it incapable of measurement by our thermometers. In the next place, if we make an allowance for the quantity of heat which thus disappears, even then the corrected calorific power converted into its mechanical equivalent would not express the quantity of work practically obtainable from the coal. In the most perfectly constructed engine the whole amount of heat generated by the combustion of the coal is not available for heating the boiler--a certain quantity is lost by radiation, by heating the material of the furnace, &c., by being carried away by the products of combustion and in other ways. Moreover, some of the coal escapes combustion by being allowed to go away as smoke, or by remaining as cinders. Then again, in the engine itself a good deal of heat is lost through various channels, and much of the working power is frittered away through friction, which reconverts the mechanical power into its equivalent in heat, only this heat is not available for further work, and is thus lost so far as the efficiency of the engine is concerned. These sources of loss are for the most part unavoidable, and are incidental to the necessary imperfections of our mechanism. But even with the most perfectly conceivable constructed engine it has been proved that we can only expect one-sixth of the total energy of the fuel to appear in the form of work, and in a very good steam-engine of the present time we only realize in the form of useful work about one-tenth of the whole quantity of energy contained in the coal. Although steam power is one of the most useful agencies that science has placed at the disposal of man, it is not generally recognized by the uninitiated how wasteful we are of Nature's resources. One of the greatest problems of applied science yet to be solved is the conversion of the energy latent in coal or other fuel into a quantity of useful work approximating to the mechanical equivalent much more closely than has hitherto been accomplished. But although we only get this small fraction of the whole working capability out of coal, the actual amount of energy dormant in this substance cannot but strike us as being prodigious. It has already been said that a pound of coal on complete combustion gives out 13,890 heat units. This quantity of heat corresponds to over 10,000,000 foot-pounds of work. A horse-power may be considered as corresponding to 550 foot-pounds of work per second, or 1,980,000 foot-pounds per hour. Thus our pound of coal contains a store of energy which, if capable of being completely converted into work without loss, would in one hour do the work of about five and a half horses. The strangest tales of necromancy can hardly be so startling as these sober figures when introduced for the first time to those unaccustomed to consider the stupendous powers of Nature. If energy is indestructible, we have a right to inquire in the next place from whence the coal has derived this enormous store. A consideration of the origin of coal, and of its chemical composition, will enable this question to be answered. The origin of coal has already been discussed. Chemically considered, it consists chiefly of carbon together with smaller quantities of hydrogen, oxygen, and nitrogen, and a certain amount of mineral matter which is left as ash when the coal is burnt. The following average analyses of different varieties will give an idea of its chemical composition:-- ------------------------------------------------------------------- Variety of Coal. | Carbon. | Hydrogen. | Oxygen. | Nitrogen. | Ash. -------------------+---------+-----------+---------+-----------+----- S. Staffordshire | 73·4 | 5·0 | 11·7 | 1·7 | 2·3 Newcastle (Caking) | 80·0 | 5·3 | 10·7 | 2·2 | 1·7 Cannel (Wigan) | 81·2 | 5·6 | 7·9 | 2·1 | 2·5 Anthracite (Welsh) | 90·1 | 3·2 | 2·5 | 0·8 | 1·6 --------------------------------------------------------------------- There are in addition to these constituents small quantities of sulphur and a certain variable amount of water (5 to 10 per cent.) in all coals, but the elements which most concern us are those heading the respective columns. From the foregoing analyses, which express the percentage composition, it will be seen that carbon is by far the most important constituent of coal. Carbon is a chemical element which is found in a crystalline form in nature as the diamond, and which forms a most important constituent of all living matter, whether animal or vegetable. Woody fibre contains a large quantity of this element, and the carbon of coal is thus accounted for; it was accumulated during the growth of the plants of the Carboniferous period. Now carbon is one of those elementary substances which are said to be _combustible_, which means that if we heat it in atmospheric air it gives out heat and light, and gradually disappears, or, as we say, burns away. The heat which is given out during combustion represents the chemical energy stored up in the combustible, for combustion is in fact the chemical union of one substance with another with the development of heat and light. When carbon burns in air, therefore, a chemical combination takes place, the air supplying the other substance with which the carbon combines. That other substance is also an element--it is the invisible gas which chemists call oxygen, and which forms one-fifth of the bulk of atmospheric air, the remainder consisting of the gas nitrogen and small quantities of other gases with which we shall have more to do subsequently. When oxygen and carbon unite under the conditions described, the product is an invisible gas known as carbon dioxide, and it is because this gas is invisible that the carbon seems to disappear altogether on combustion. In reality, however, the carbon is not lost, for matter is as indestructible as energy, but it is converted into the dioxide which escapes as gas under ordinary circumstances. If, however, we burn a given weight of carbon with free access of air, and collect the product of combustion and weigh it, we shall find that the product weighs more than the carbon, by an amount which represents the weight of oxygen with which the element has combined. By careful experiment it would be found that one part by weight of carbon would give three and two-third parts by weight of carbon dioxide. If, moreover, we could measure the quantity of heat given out by the complete combustion of one pound of carbon, it would be found that this quantity would raise 14,544 lbs. of water through 1° F., a quantity of heat corresponding to over eleven million foot-pounds of work, or about seven and three-quarters horse-power per hour. Here then is the chief source of the energy of coal--the carbon of the plants which lived on this earth long ages ago has lain buried in the earth, and when we ignite a coal fire this carbon combines with atmospheric oxygen, and restores some of the energy that was stored up at that remote period. But the whole of the energy dormant in coal is not due to the carbon, for this fuel contains another combustible element, hydrogen, which is also a gas when in the free state, and which is one of the constituents of water, the other constituent being oxygen. In fact, there is more latent energy in hydrogen, weight for weight, than there is in carbon, for one pound of hydrogen on complete combustion would give enough heat to raise 62,032 lbs. of water through 1° F. Hydrogen in burning combines with oxygen to form water, so that the products of the complete combustion of coal are carbon dioxide and water. The amount of heat contributed by the hydrogen of coal is, however, comparatively insignificant, because there is only a small percentage of this element present, and we thus come to the conclusion that nearly all the work that is done by our steam-engines of the present time is drawn from the latent energy of the carbon of the fossilized vegetation of the Carboniferous period. The conclusion to which we have now been led leaves us with the question as to the _origin_ of the energy of coal still unanswered. We shall have to go a step further before this part of our story is complete, and we must form some kind of idea of the way in which a plant grows. Carbon being the chief source of energy in coal, we may for the present confine ourselves to this element, of which woody fibre contains about 50 per cent. Consider the enormous gain in weight during the growth of a plant; compare the acorn, weighing a few grains, with the oak, weighing many tons, which arises from it after centuries of growth. If matter is indestructible, and never comes into existence spontaneously, where does all this carbon come from? It is a matter of common knowledge that the carbon of plants is supplied by the atmosphere in the form of carbon dioxide--the gas which has already been referred to as resulting from the combustion of carbon. This gas exists in the atmosphere in small quantity--about four volumes in 10,000 volumes of air; but insignificant as this may appear, it is all important for the life of plants, since it is from this source that they derive their carbon. The origin of the carbon dioxide, which is present as a normal constituent of the atmosphere, does not directly concern us at present, but it is important to bear in mind that this gas is one of the products of the respiration of animals, so that the animal kingdom is one of the sources of plant carbon. The transition from carbon dioxide to woody fibre is brought about in the plant by a series of chemical processes, and through the formation of a number of intermediate products in a manner which is not yet thoroughly understood; but since carbon dioxide consists of carbon and oxygen, and since plants feed upon carbon dioxide, appropriating the carbon and giving off the oxygen as a waste product, it is certain that work of some kind must be performed. This is evident, because it has been explained that when carbon combines with oxygen a great deal of heat is given out, and as this heat is the equivalent of the energy stored in the carbon, it follows from the doctrine of the Conservation of Energy, that in order to separate the carbon from the oxygen again, just the same amount of energy must be supplied as is evolved during the combustion of the carbon. If a pound of carbon in burning to carbon dioxide gives out heat equivalent to eleven million foot-pounds of work, we must apply the same amount of work to the carbon dioxide produced to separate it into its constituents. Neither a plant nor any living thing can create energy any more than it can create matter, and just as the matter composing a living organism is assimilated from external sources, so must we look to an external source for the energy which enables the plant to do this large amount of chemical work. The separation of carbon from oxygen in the plant is effected by means of energy supplied by the sun. The great white hot globe which is the centre of our system, and round which this earth and the planets are moving, is a reservoir from which there is constantly pouring forth into space a prodigious quantity of energy. It must be remembered that the sun is more than a million times greater in bulk than our earth. It has been calculated by Sir William Thomson that every square foot of the sun's surface is radiating energy equivalent to 7000 horse-power in work. On a clear summer day the earth receives from the sun in our latitude energy equal to about 1450 horse-power per acre. To keep up this supply by the combustion of coal, we should have to burn for every square foot of the sun's surface between three and four pounds per second. A small fraction of this solar energy reaches our earth in the form of radiant heat and light, and it is the latter which enables the plant to perform the work of separating the carbon from the oxygen with which it is chemically combined. It is, in fact, well known that the growth of plants--that is, the assimilation of carbon and the liberation of oxygen--only takes place under the influence of light. This function is performed by the leaves which contain the green colouring-matter known as chlorophyll, the presence of which is essential to the course of the chemical changes. If we now sum up the results to which we have been led, it will be seen-- (1) That the chief source of the energy contained in coal is the carbon. (2) That this carbon formed part of the plants which grew during the Carboniferous period. (3) That the carbon thus accumulated was supplied to the plants by the carbon dioxide existing in the atmosphere at that time. (4) That the separation of the carbon from the oxygen was effected in the presence of chlorophyll, by means of the solar energy transmitted to the earth during the Carboniferous period. We thus arrive at the interesting conclusion, that the heat which we get from coal is sunlight in another form. For every pound of coal that we now burn, and for every unit of heat or work that we get from it, an equivalent quantity of sunlight was converted into the latent energy of chemical separation during the time that the coal plant grew. This energy has remained stored up in the earth ever since, and reappears in the form of heat when we cause the coal to undergo combustion. It is related that George Stephenson when asked what force drove his locomotive, replied that it was "bottled-up sunshine," and we now see that he was much nearer the truth in making this answer than he could have been aware of at the time. Before passing on to the consideration of the different products which we get from coal, it will be desirable to discuss a little more fully the nature of the change which occurs during the transformation of wood into coal. Pure woody fibre consists of a substance known to chemists as cellulose, which contains fifty per cent. of carbon, the remainder of the compound being made up of hydrogen and oxygen. It is thus obvious that during the fossilization of the wood some of the other constituents are lost, and the percentage of carbon by this means raised. We can trace this change from wood, through peat, lignite, and the different varieties of coal up to graphite, which is nearly pure carbon. It is in fact possible to construct a series showing the conversion of wood into coal, this series comprising the varieties given in the table on p. 23, as well as younger and older vegetable deposits. The series will be-- I. Woody fibre (cellulose). II. Peat from Dartmoor. III. Lignite, or brown coal, an imperfectly carbonized vegetable deposit of more recent geological age than true coal. IV. Average bituminous coal. V. Cannel coal from Wigan. VI. Anthracite from Wales. VII. Graphite, the oldest carbonaceous mineral. The percentage of the chief elements in the members of this series is-- Carbon. Hydrogen. Oxygen. I. 50·0 6·0 44·0 II. 54·0 5·2 28·2 III. 66·3 5·6 22·8 IV. 77·0 5·0 11·2 V. 81·2 5·6 7·9 VI. 90·1 3·2 2·5 VII. 94-99·5, the remainder being ash. In the above table the increase of carbon and the decrease of oxygen is well brought out; the hydrogen also on the whole decreases, although with some irregularity. The exact course of the chemical change which occurs during the passage of wood into coal is at present involved in obscurity. The oxygen may be eliminated in the form of water or of carbon dioxide or both; some of the carbon is got rid of in the form of marsh gas, a compound of carbon and hydrogen, which forms the chief constituent of the dangerous "fire-damp" of coal mines. Marsh gas is an inflammable gas which becomes explosive when mixed with air and ignited; it often escapes with great violence during the working of coal seams, the jets blowing out from the coal or underclay with a rushing noise, indicative of the high pressure under which the hydrocarbon gas has accumulated. These jets of escaping gas are known amongst miners as "blowers." If the air of a mine contains a sufficient quantity of the gas, and a flame accidentally fires the mixture, there results one of those disastrous explosions with which the history of coal mining has unfortunately only made us too familiar. From the account of coal which has thus far been rendered, it will be seen that as a source of mechanical power, we are far from using it as economically as could be desired; and when we look at our open grates with clouds of unburnt carbon particles escaping up the chimney, and so constructed that only a small fraction of the total heat warms our rooms, it will be seen that the tale of waste is still more deplorable. But we are at present rather concerned with what we actually do get from coal than with what we ought to get from it, and here, when we come to deal with the various material products, we shall have a better account to present. If instead of heating coal in contact with air and allowing it to burn, we heat it in a closed vessel, such as a retort, it undergoes decomposition with the formation of various gaseous, liquid, and solid products. This process of heating an organic compound in a closed vessel without access of air and collecting the products, is called destructive distillation. The tobacco-pipe experiment of our boyhood is our first practical introduction to the destructive distillation of coal. We put some powdered coal into the bowl of the pipe, plaster up the opening with clay and then insert the bowl in a fire, allowing the stem to project from between the bars of the grate. In a few minutes a stream of gas issues from the orifice of the stem; on applying a light it burns with a luminous flame, and we have made coal-gas on a small scale. In the destructive distillation of organic substances, such as wood or coal, there are always produced four things--gas, watery liquid, and viscous products known as tar, while a residue of coke or charcoal is left in the retort. This is a very old observation, and was made so long ago that it becomes interesting as a point in the history of applied science to know who first submitted coal to destructive distillation. According to Dr. Gustav Schultz, we must credit a German with this observation, which was made towards the end of the seventeenth century (about 1680) by a chemist named Johann Joachim Becher. The experiment is described in such a quaint manner that the exact words of the author are worthy of being reproduced, and the passage is here given as translated by Dr. Lunge in his work on _Coal Tar and Ammonia_-- "In Holland they have peat, and in England pit-coals; neither of them is very good for burning, be it in rooms or for smelting. But I have found a way, not merely to burn both kinds into good coal (coke) which not any more smokes nor stinks, but with their flame to smelt equally well as with wood, so that a foot of such coal makes flames 10 feet long. That I have demonstrated with pit-coal at the Hague, and here in England at Mr. Boyles', also at Windsor on the large scale. In this connection it is also noteworthy that, equally as the Swedes make their tar from firwood, I have here in England made from pit-coal a sort of tar which is equal to the Swedish in every way, and for some operations is even superior to it. I have made proof of it on wood and on ropes, and the proof has been found right, so that even the king has seen a specimen of it, which is a great thing in England, and the coal from which the tar has been taken out is better for use than before." This enterprising chemist, moreover, brought his results to a practical issue, for he secured a patent, in conjunction with Henry Serle, in 1681, for "a new way of making pitch and tarre out of pit-coale, never before found out or used by any other." No less interesting is the work of our own clergy during the last century, when many eminent divines appear to have devoted their leisure to experimental science. Thus, about the year 1688 the Rev. John Clayton, D.D., Dean of Kildare, went to examine a ditch two miles from Wigan in Lancashire, the water in which had been stated to "burn like brandy" when a flame was applied to it. The Dean ultimately traced the phenomenon to an escape of inflammable gas from an underlying coal seam, and he followed up the matter experimentally by studying the destructive distillation of Wigan coal in retorts. The results were communicated to the Hon. Robert Boyle, but were not published till after the death of the latter, and long after the death of the author. The following account is taken from the abridged edition of the _Philosophical Transactions_ (1739):-- "At first there came over only phlegm, afterwards a black oil, and then also a spirit arose, which he could noways condense, but it forced the luting, or broke the glasses. Once, when it had forced the lute, coming close to it to try to repair it, he observed that the spirit which issued out caught fire at the flame of the candle, and continued burning with violence as it issued out in a stream, which he blew out and lighted again alternately for several times. He then tried to save some of this spirit. Taking a turbinated receiver, and putting a candle to the pipe of the receiver while the spirit rose, he observed that it caught flame, and continued burning at the end of the pipe, though you could not discern what fed the flame. He then blew it out, and lighted it again several times; after which he fixed a bladder, flatted and void of air, to the pipe of the receiver. The oil and phlegm descended into the receiver, but the spirit, still ascending, blew up the bladder. He then filled a good many bladders with it, and might have filled an inconceivable number more; for the spirit continued to rise for several hours, and filled the bladders almost as fast as a man could have blown them with his mouth; and yet the quantity of coals he distilled was inconsiderable. "He kept this spirit in the bladders a considerable time, and endeavoured several ways to condense it, but in vain. And when he wished to amuse his friends, he would take one of the bladders, and pricking a hole with a pin, and compressing gently the bladder near the flame of a candle till it once took fire, it would then continue flaming till all the spirit was compressed out of the bladder."[1] The Rev. Stephen Hales, D.D., Rector of Farringdon, Hants, was the author of a book entitled _Statical Essays, containing Vegetable Staticks_, printed in 1726-27, and of which the third edition bears the date 1738. At p. 182 of this work, after a previous description of the destructive distillation of all kinds of substances in iron or other retorts, he says-- "By the same means also I found plenty of air [gas] might be obtained from minerals. Half a cubick inch, or 158 grains of Newcastle coal, yielded in distillation 180 cubick inches of air [gas], which arose very fast from the coal, especially while the yellowish fumes ascended." Still later, viz. about 1767, we have the Rev. R. Watson, D.D., Regius Professor of Divinity in the University of Cambridge, and Bishop of Llandaff, interesting himself in chemistry. He wrote a series of _Chemical Essays_, one of which is entitled, _Of Pit Coal_, and in this he describes the production from coal (by destructive distillation) of illuminating gas, ammonia-water, tar, and coke. He further compares the relative quantities of the different products from various kinds of coal, but he appears to have been chiefly interested in the tar, and disregarded the gas and other products. Not the least interesting part of his book is the preface, in which he apologizes for his pursuits in the following words-- "Divines, I hope, will forgive me if I have stolen a few hours, not, I trust, from the duties of my office, but certainly from the studies of my profession, and employed them in the cultivation of natural philosophy. I could plead in my defence, the example of some of the greatest characters that ever adorned either this University or the Church of England." This is quoted from the 5th edition, dated 1789, the essay on coal being in the second of five volumes. As the learned bishop published other works on chemistry, we may suppose that the forgiveness which he asks from his brother divines was duly accorded. None of these preliminary experiments, however, led to any immediate practical result so far as concerns the use of coal-gas as an illuminating agent. Towards the end of the last century the lighting of individual establishments commenced, and the way was thus prepared for the manufacture of the gas on a large scale. One of the earliest pioneers was the ninth Earl of Dundonald, an inventive genius, who in 1782 at Culross Abbey became one of the first practical tar distillers. He secured letters patent in 1781 for making tar, pitch, essential oils, volatile alkali, mineral acids, salts, and cinders from coal. The gas was only a waste product, and, strange as it may appear, the Earl, whose operations were financial failures, did not realize the importance of the gas, the tar and coke being considered the only products of value. Here is the account of the experiments by his son, Admiral Dundonald, the Sailor Earl, quoted from his _Autobiography of a Seaman_:-- "In prosecution of his coal-tar patent, my father went to reside at the family estate of Culross Abbey, the better to superintend the works on his own collieries, as well as others on the adjoining estates of Valleyfield and Kincardine. In addition to these works, an experimental tar-kiln was erected near the Abbey, and here coal-gas became accidentally employed in illumination. Having noticed the inflammable nature of a vapour arising during the distillation of tar, the Earl, by way of experiment, fitted a gun-barrel to the eduction pipe leading from the condenser. On applying fire to the muzzle, a vivid light blazed forth across the waters of the Frith, becoming, as was afterwards ascertained, distinctly visible on the opposite shore." A few years later the foundation of the coal-gas manufacture was laid by William Murdoch, a Scotchman, who must be credited with the practical introduction of this illuminating agent. The idea had about the same time occurred to a Frenchman, Lebon, but in his hands the suggestion did not take a practical form. Murdoch was overseer of some mines in Cornwall, and in 1792 he first lighted his own house at Redruth. He then transferred his services to the great engineering firm of Boulton and Watt at Soho, near Birmingham, where he erected apparatus in 1798, and in the course of a few years the whole of this factory was permanently lighted by gas. From this time the introduction of gas into other factories at Manchester and Halifax was effected by Murdoch and his pupil, Samuel Clegg. From single factories coal-gas at length came into use as a street illuminant, although somewhat tardily. Experiments were made in London at the Lyceum Theatre in 1803, in Golden Lane in 1807, and in Pall Mall two years later. It was fifteen years from the time of Murdoch's first installation at Soho before the streets of London were lighted by gas on a commercial scale. Our grandfathers seem to have had a great dread of gas, and public opposition no doubt had much to do with its exclusion from the metropolis. There were even at that time eminent literary and scientific men who did not hesitate to cast ridicule upon the proposal, and to declare the scheme to be only visionary. But about 1806 there came into this country an energetic German who passed by the name of Winsor, and who is described as an ignorant adventurer, whose real name was Winzler. Whatever his origin, he certainly helped to rouse the public interest in gas lighting. He took out a patent, he gave public lectures, and collected large sums of money for the establishment of gas companies. Most of the capital was, however, squandered in futile experiments, but at length in 1813, Westminster Bridge, and a year later St. Margaret's parish, was successfully lighted. From that period the use of gas extended, but it was some time before the public fears were allayed, for it is related that Samuel Clegg, who undertook the lighting of London Bridge, had at first to light his own lamps, as nobody could be found to undertake this perilous office. Even after gas had come into general use as a street illuminant, it must have found its way but slowly into private houses. In an old play-bill of the Haymarket Theatre, dated 1843--thirty years after the first introduction into the streets--it is announced-- "Among the most important Improvements, is the introduction (for the first time) of Gas as the Medium of Light!" The manufacture of coal-gas, first rendered practicable by the energy and skill of the Scotch engineer Murdoch, is now carried on all over the country on a colossal scale. It is not the province of the present volume to deal with the details of manufacture, but a short description of the process is necessary for the proper understanding of the subsequent portions of the subject (see Fig. 3). The coal is heated in clay cylinders, called retorts, provided with upright exit pipes through which the volatile products escape, and are conducted into water contained in a horizontal pipe termed the "hydraulic main." In the latter the gas is partially cooled, and deposits most of the tar and watery liquor which distil over at the high temperature to which the retorts are heated. The tar and watery liquor are allowed to flow from the hydraulic main into a pit called the "tar well," and the gas then passes through a series of curved pipes exposed to the air, in which it is further cooled, and deposits more of the tar. From this "atmospheric condenser" the gas passes into a series of vessels filled with coke, down which a fine spray of water is constantly being blown. These vessels, known as "scrubbers," serve to remove the last traces of tar, and some of the volatile sulphur compounds which are formed from the small quantity of sulphur present in most coals. The removal of sulphur compounds is a matter of importance, because when gas is burnt these compounds give rise to acid vapours, which are deleterious to health and destructive to property. [Illustration: FIG. 3.--Sectional diagram of gas plant. The retorts and furnace are on the right; the gas rises through the upright pipe T into the hydraulic main B; from there it passes into the atmospheric condensers D, from the lower cistern of which the condensed tar flows into the tar-well, H. Passing up through K, the gas is conducted into the scrubber, O, and from there into the purifier, M. From there it emerges through K' into the purifier, M, and then into the gas-holder for distribution. (From Schultz's _Chemie des Steinkohlentheers_.)] From the scrubbers the gas is sent through another series of vessels packed with trays of lime or oxide of iron, in order to remove sulphuretted hydrogen and other sulphur compounds as completely as possible. A small quantity of carbon dioxide is also removed by these "purifiers," as the presence of this gas impairs the illuminating power of coal-gas. From the purifiers the gas passes into the gas-holders, where it is stored for distribution. It remains only to be stated that the distillation of coal is effected under a pressure somewhat less than that of the atmosphere, the products of distillation being pumped out of the retorts by means of a kind of air-pump, called an exhauster, which is interpolated between the hydraulic main and the condenser, or at some other part of the purifying system. The coke left in the retort is used as fuel for burning under the retorts or for other purposes. The oxide of iron used in the purifiers can be used over and over again for a certain number of times by exposing it to the air, and when it is finally exhausted, the sulphur can be burnt out of it and used for making that most important of all chemical products, sulphuric acid. Thus the small quantity of sulphur present in the original coal (probably in the form of iron pyrites) is rendered available for the manufacture of a useful product. The necessarily brief description of this important industry will suffice for the general reader. Those who desire further information on points of detail will refer to special works. We are here rather concerned with the subsequent fate of the different products, four of which have to be dealt with, viz. the gas, watery liquor, tar, and coke. The first and last of these having already been accounted for--the one as an illuminating agent and the other as fuel--may now be dismissed. No story of applied science is complete unless we can form some idea of the quantities of material used, and the amount of the products obtained. From one ton of Newcastle coal we get about 10,000 cubic feet of gas, 110 to 120 lbs. of tar, 20 to 25 gallons of watery liquor, and about 1500 lbs. of coke. Different coals of course give different quantities, and the latter vary also according to the heat of distillation; but the above estimate will furnish a good basis for forming our ideas with some approach to precision. It has been estimated also that we are now distilling coal at the rate of about ten million tons per annum, so that there is annually produced 100,000 million cubic feet of gas, and about 500,000 tons of tar, besides proportionate quantities of the other products. The great metropolitan companies alone are consuming nearly three million tons annually for the production of gas, a consumption corresponding to about 6000 cubic feet per head of the population. This of course takes no account of the coal used for other manufactures or for domestic purposes, but it is interesting to compare these estimates with the consumption of coal in London about a century ago, before the introduction of gas, when, as Bishop Watson tells us in his work already referred to, the annual consumption was 922,394 tons. The enormous quantity of tar resulting from our gas manufacture furnishes the raw material for the production of a multitude of valuable substances--colouring-matters, medicines, perfumes, flavouring-matters, burning and lubricating oils, &c. Out of this unsavoury waste material of the gas-works, the researches of chemists have enabled a great industry to spring up which is of continually growing importance. It will be the object of the remaining portion of the present volume to set forth the achievements of science in this branch of its application. The foundation of the coal-tar industry was laid in this country--the country where coal was first distilled on a large scale for the production of gas, and where the first of the coal-tar colouring-matters was sent forth into commerce. We are at the present time the largest tar producers in Europe; it has been stated that we produce more than double the whole quantity of tar made in the gas-using countries of Europe; but in spite of this, our manufacture of finished products is by no means in that flourishing condition which might be expected from our natural resources in the way of coal, and the facilities which we possess for manufacturing the raw materials out of it. But we must now take a glance at some of the other uses to which coal is put in order to realize more completely the truth of the statement made some pages back, viz. that this mineral has been the chief source of our industrial prosperity. Great as is the consumption of coal by the gas manufacturer, there is an equal or even a greater demand for the carbonaceous residue left when the coal has been decomposed by destructive distillation or by partial combustion. This residue is coke--the substance left in the retorts after the gas manufacture. There is a great demand for coke for many purposes; it is used in most cases where a cheap smokeless fuel is required; it is burnt in the furnaces of locomotives and other engines, and is very largely consumed by the iron smelter in the blast furnace. To meet these demands a large quantity of coal is converted into coke by being burnt in ovens with an insufficient supply of air for complete combustion, or in suitably constructed close furnaces. The tar and other products have in this country until recently been allowed to escape as waste, but the time is approaching when these must be utilized. It will give an idea of the industrial importance of coke when it is stated, that about twelve million tons of our coal annually undergo conversion into this form of fuel. Chemically considered, coke consists of carbon together with all the mineral constituents of the coal, and small quantities of hydrogen, oxygen, and nitrogen. The amount of carbon varies from 85 to 97, and the ash from 3 to 14 per cent. The conversion of coal into coke is a very venerable branch of manufacture, which was first carried out on a large scale in this country about the middle of the seventeenth century. As an operation it may appear utterly devoid of romance, but as Goethe has described his visit to the earliest of coke-burners, this fragment of history is worth narrating. When the great German philosophical poet was a student at Strassburg (1771), he rode over with some friends to visit the neighbourhood of Saarbrücken where he met an old "coal philosopher" named Stauf, who was there carrying on the industry. This "philosophus per ignem" was manager of some alum works, and the ruling spirit of the "burning hill" of Duttweiler. The hill no doubt owed its designation to the coke ovens at work upon it, and which had been in operation there for some six or seven years before Goethe's visit, _i.e._ since 1764. The coke was wanted for iron smelting, and even at that early period Stauf had the wisdom to condense his volatile products, for we are told that he showed his visitors bitumen, burning-oil, lampblack, and even a cake of sal ammoniac resulting from his operations. Goethe has put upon record his visit to the little haggard old coke-burner, living in his lonely cottage in the forest (_Aus meinem Leben: Wahrheit und Dichtung_, Book X). It is probably Stauf's ovens which are described by the French metallurgist, De Gensanne, in his _Traité de la fonte des Mines par le feu du Charbon de Terre_, published in Paris in 1770. After long years of coke-making, without any regard to the value of the volatile products, we are now beginning to consider the advisability of doing that which has long been done on the Continent. It is not unlikely that Bishop Watson in the last century had heard of the attempt to recover the products from coke ovens, for he gives the following very sound advice in his _Chemical Essays_:-- "Those who are interested in the preparation of coak would do well to remember that every 96 ounces of coal would furnish four ounces at the least of oil, probably six ounces might be obtained; but if we put the product so low as five ounces from 100, and suppose a coak oven to work off only 100 tons of coal in a year, there would be a saving of five tons of oil, which would yield above four tons of tar; the requisite alteration in the structure of the coak ovens, so as to make them a kind of distilling vessels, might be made at a very trifling expense."--5th ed., 1789, vol. ii. p. 351. We have yet to chronicle another chapter in the history of coal philosophy before finishing with this part of the subject. There is a branch of manufacture carried on, especially in Scotland, which results in the production of burning and lubricating oils, and solid paraffin, a wax-like substance which is used for candle-making. The manufacture of candles out of coal will perhaps be a new revelation to many readers of this book. It must be admitted, however, that the term "coal" is here being extended to only partially fossilized vegetation of younger geological age than true coal, and to bituminous shales of various ages. Shale, geologically considered, is hardened mud; it may be looked upon as clay altered by time and pressure. Now if the mud, at the period of its deposition, was much mixed up with vegetable matter, we should have in course of time a mixture of more or less carbonized woody fibre with mineral matter, and this would be called a carbonaceous or bituminous shale. Shales of this kind often contain as much as 80 to 90 per cent. of mineral matter, and seldom more than 20 per cent. of volatile matter, _i.e._ the portion lost on ignition, and consisting chiefly of the carbonaceous constituents. The story of the shale-oil industry is soon told. About the year 1847 oil was "struck" in a coal mine at Alfreton in Derbyshire, and in the hands of Mr. James Young this supply furnished the market with burning-oil for nearly three years. Then the spring became exhausted, and Mr. Young and his associates had to look out for another source of oil. Be it remembered that this happened some nine years before the utilization of the great American petroleum deposits. Many kinds of vegetable matter were submitted to destructive distillation before a substance was found which could be profitably worked, but at length Mr. Young tried a kind of cannel coal which had about that time been introduced for gas making. This substance was called Boghead gas coal or Torbane Hill mineral, from the place where it occurred, which is at Bathgate in Linlithgow. This mineral was found to yield a large amount of paraffin oil and solid paraffin on destructive distillation, and from that time (1850) to this, the industry has been carried on at Bathgate and other parts of Scotland, where similar carbonaceous deposits occur. It may seem a matter of unimportance at the present time whether this Torbane Hill mineral is a true coal or not. About forty years ago, however, the decision of this question involved a costly law-suit in Edinburgh. The proprietor of the estate had granted a lease to a firm, conveying to the latter the right to work coal, limestone, ironstone, and certain other minerals found thereon, but excluding copper and all other minerals not mentioned in the contract. The lessees then found that this particular carbonaceous mineral was of very great value, both on account of the high quality of the gas, and afterwards on account of the paraffin which it furnished by Young's process of distillation. Thereupon the lessor brought an action against the lessees, claiming £10,000 damages, on the ground that the latter had broken the contract by removing a mineral which was not coal. Experts gave evidence on both sides; some declared in favour of the substance being coal, others said it was a bituminous shale, while others called it bituminated clay, or refused to give it a name at all. Judgment was finally given for the defendants, so that in the eye of the law the mineral was considered a true coal. As a matter of fact, it is impossible to draw a hard and fast line between coal and bituminous shale, as the one is connected with the other by a series of intermediate minerals, and the Torbane Hill mineral happens to form one of the links. It contains about 69 per cent. of volatile matter, and leaves 31 per cent. of residue, consisting of 12 parts of carbon and 19 of ash. The manufacture started by Young has developed into an important industry, in spite of the fact that the original Torbane Hill coal has become exhausted, and that enormous natural deposits of petroleum are worked in America, Russia, and elsewhere. There are now some fifteen companies at work in Scotland, representing an aggregate capital of about two and a half million pounds sterling. Bituminous shales of different kinds are distilled at a low red heat in iron retorts, and from the volatile portions there are separated those valuable products which have already been alluded to, viz. burning and lubricating oils, solvent mineral oil, paraffin wax for candles, and ammonia. We may fairly claim these as coal products, although the shales used contain much mineral matter, the carbon averaging about 20 per cent., the hydrogen three per cent., the nitrogen 0·7, and the ash about 67 per cent. The shales worked are approximately of the same age as true coal, _i.e._ Carboniferous. The Scotch companies are distilling about two million tons of shale per annum, this quantity producing about sixty million gallons of crude oil, and giving employment to over 10,000 hands. It is not the province of the present work to enter into the chemical nature of the products of destructive distillation in any greater detail than is necessary to enable the general reader to know something of the recent discoveries in the utilization of these products. We shall, however, have occasion later on to make ourselves acquainted with the names of some of the more important raw materials which are derived from this source, and certain preliminary explanations are indispensable. In the first place then, let us start from the fact that coal--including carbonaceous shale and lignite--when heated in a closed vessel gives gas, tar, coke, and a watery liquor. A clear understanding must be arrived at concerning the manner in which these products arise. There is a widely-spread notion that the substances derived from coal and utilized for industrial purposes are present in the mineral itself, and that the art of the chemist has been exercised in separating the said substances by various processes. This idea must be at once dispelled. It is true that there is a small quantity of water and a certain amount of gas already present in most coals, but these are quite insignificant as compared with the total yield of gas and watery liquor. So also with respect to the tar; it is possible that in some highly bituminous minerals we might dissolve out a small quantity of tarry matter by the use of appropriate solvents, but in the coals mostly used for gas-making not a trace of tar exists ready formed, and still less can it be said that the coal contains coke. All these products are formed _by the chemical decomposition of the coal_ under the influence of heat, and their nature and quantity can be made to vary within certain limits by modifying the temperature of distillation. Having once realized this principle with respect to coal itself, it is easy to extend it to the products of its destructive distillation. The tar, for instance, is a complicated mixture of various substances, among which hydrocarbons--_i.e._ compounds of carbon with hydrogen--largely predominate. The different components of coal-tar can be separated by processes which we shall have to consider subsequently. Of the compounds thus isolated some few are immediately applicable for industrial purposes, but the majority only form the raw materials for the manufacture of other products, such as colouring-matters and medicines. Now these colouring-matters and other finished products no more exist in the tar than the latter exists in the coal. They are produced from the hydrocarbons, &c., present in the tar _by chemical processes_, and bear much about the same relationship to their parent substances that a steam-engine bears to the iron ore out of which its metallic parts are primarily constructed. Just as the mechanical skill of the engineer enables him to construct an engine out of the raw material iron, which is extracted from its ore, and converted into steel by chemical processes, so the skill of the chemist enables him to build up complex colouring-matters, &c., out of the raw materials furnished by tar, which is obtained from coal by chemical decomposition. The illuminating gas which is obtained from coal by destructive distillation consists chiefly of hydrogen and gaseous hydrocarbons, the most abundant of the latter being marsh gas. There are also present in smaller quantities the two oxides of carbon, the monoxide and the dioxide, which are gaseous at ordinary temperatures, together with other impurities. Coal-gas is burnt just as it is delivered from the mains--it is not at present utilized as a source of raw material in the sense that the tar is thus made use of. In some cases gas is used as fuel, as in gas-stoves and gas-engines, and in the so-called "gas-producers," in which the coal, instead of being used as a direct source of heat, is partially burnt in suitable furnaces, and the combustible gas thus arising, consisting chiefly of carbon monoxide, is conveyed to the place where it undergoes complete combustion, and is thus utilized as a source of heat. Summing up the uses of coal thus far considered, we see that this mineral is being consumed as fuel, for the production of coke, for the manufacture of gas, and in many other ways. Lavishly as Nature has provided us with this source of power and wealth, the idea naturally suggests itself whether we are not drawing too liberally upon our capital. The question of coal supply crops up from time to time, and the public mind is periodically agitated about the prospects of its continuance. How long we have been draining our coal resources it is difficult to ascertain. There is some evidence that coal-mining was carried on during the Roman occupation. In the reign of Richard I. there is distinct evidence of coal having been dug in the diocese of Durham. The oldest charters take us back to the early part of the thirteenth century for Scotland, and to the year 1239 for England, when King Henry III. granted a right of sale to the townsmen of Newcastle. With respect to the metropolis, Bishop Watson, on the authority of Anderson's _History of Commerce_, states that coal was introduced as fuel at the beginning of the fourteenth century. In these early days, when it was brought from the north by ships, it was known as "sea-coal":-- "Go; and we'll have a posset for 't soon at night, in faith, at the latter end of a sea-coal fire."--_Merry Wives of Windsor_, Act I., Sc. iv. That the fuel was received at first with disfavour appears from the fact that in the reign of Edward I. the nobility and gentry made a complaint to the king objecting to its use, on the ground of its being a public nuisance. By the middle of the seventeenth century the use of coal was becoming more general in London, chiefly owing to the scarcity of wood; and its effects upon the atmosphere of the town will be inferred from a proclamation issued in the reign of Elizabeth, prohibiting its use during the sitting of Parliament, for fear of injuring the health of the knights of the shire. About 1649 the citizens again petitioned Parliament against the use of this fuel on account of the stench; and about the beginning of that century "the nice dames of London would not come into any house or roome when sea-coales were burned, nor willingly eat of meat that was either sod or roasted with sea-coale fire" (_Stow's Annals_). For many centuries therefore we have been drawing upon our coal supplies, and using up the mineral at an increasing rate. According to a recent estimate by Professor Hull, from the beginning of the present century to 1875 the output has been more than doubled for each successive quarter century. The actual amount of coal raised in the United Kingdom between 1882 and the present time averages annually about 170 million tons, corresponding in money value to about £45,000,000 per annum. In 1860 the amount of coal raised in Great Britain was a little more than 80 million tons, and Professor Hull estimated that at that rate of consumption our supplies of workable coal would hold out for a thousand years. Since then the available stock has been diminished by some 3,650 million tons, and even this deduction, we are told on the same authority, has not materially affected our total supply. The possibility of a coal famine need, therefore, cause no immediate anxiety; but we cannot "eat our loaf and have it too," and sooner or later the continuous drain upon our coal resources must make itself felt. The first effect will probably be an increase in price owing to the greater depth at which the coal will have to be worked. The whole question of our coal supply has, however, recently assumed a new aspect by the discovery (February 1890) of coal at a depth of 1,160 feet at Dover. To quote the words of Mr. W. Whitaker--"It may be indeed that the coal supply of the future will be largely derived from the South-East of England, and some day it may happen, from the exhaustion of our northern coal-fields, that we in the south may be able successfully to perform a task now proverbially unprofitable--_we may carry coal to Newcastle_." The coal-fields of Great Britain and Ireland occupy, in round numbers, an area of 11,860 square miles, or about one-tenth of the whole area of the land surface of the country. Within this area, and down to a depth of 4,000 feet, lie the main deposits of our available wealth. Some idea of the amount of coal underlying this area will be gathered from the table[2] on the next page. This supply, amounting to over 90,000 million tons, refers to the exposed coal-fields and to workable seams, _i.e._ those above one foot in thickness. But in addition to this, we have a large amount of coal at workable depths under formations of later geological age than the Carboniferous, such as the Permian formation of northern and central England. Adding the estimated quantity of coal from this source to that contained in the exposed coal-fields as given above, we arrive at the total available supply. This is estimated to be about 146,454 million tons. To this we may one day have to add the coal under the south-eastern part of England. Amount of coal in millions of tons to depths not exceeding Coal Fields of-- 4,000 feet. South Wales 32,456 Forest of Dean 265 Bristol 4,219 Warwickshire 459 S. Staffordshire, Shropshire, Forest of Wyre and Clee Hills 1,906 Leicestershire 837 North Wales 2,005 Anglesey 5 N. Staffordshire 3,825 Lancashire and Cheshire 5,546 Yorkshire, Derbyshire, and Northumberland 18,172 Black Burton 71 Northumberland and Durham 10,037 Cumberland 405 Scotland 9,844 Ireland 156 It is important to bear in mind, that out of the 170 million tons of coal now being raised annually we only use a small proportion, viz. from 5 to 6 per cent. for gas-making. The largest amount (33 per cent.) is used for iron-smelting,[3] and about 15 per cent. is exported; the remainder is consumed in factories, dwelling-houses, for locomotion, and in the smaller industries. The enormous advancement which has taken place of late years in the industrial applications of electricity has given rise to the belief that coal-gas will in time become superseded as an illuminating agent, and that the supply of tar may in consequence fall off. So far, however, the introduction of electric-lighting has had no appreciable effect upon the consumption of gas, and even when the time of general electric-lighting arrives there will arise as a consequence an increased demand for gas as a fuel in gas engines. Moreover, the use of gas for heating and cooking purposes is likely to go on increasing. Nor must it be forgotten that the quantity of tar produced in gas-works is now greater than is actually required by the colour-manufacturer, and much of this by-product is burnt as fuel, so that if the manufacture of gas were to suffer to any considerable extent there would still be tar enough to meet our requirements at the present rate of consumption of the tar-products. Then again, the value of the tar, coke, and ammoniacal liquor is of such a proportion as compared with the cost of the raw material, coal, that there is a good margin for lowering the price of gas when the competition between the latter and electricity actually comes about. It will not then be only a struggle between the two illuminants, but it will be a question of electricity _versus_ gas, _plus_ tar and ammonia. While the electrician is pushing forward with rapid strides, the chemist is also moving onwards, and every year witnesses the discovery of new tar products, or the utilization of constituents which were formerly of little or no value. Thus if the cost of generating and distributing electricity is being lowered, on the other hand the value of coal tar is likely to go on advancing, and it would be rash to predict which will come out triumphant in the end. But even if electricity were to gain the day it would be worth while to distil coal at the pit's mouth for the sake of the by-products, and there is, moreover, the tar from the coke ovens to fall back upon--a source which even before the use of coal-gas the wise Bishop of Llandaff advised us not to neglect. CHAPTER II. The nature of the products obtained by the destructive distillation of coal varies according to the temperature of distillation, and the age or degree of carbonization of the coal. The watery liquor obtained by the dry distillation of wood is acid, and contains among other things acetic acid, which is sometimes prepared in this way, and from its origin is occasionally spoken of as "wood vinegar." The older the wood, the more complete its degree of conversion into coal, and the smaller the quantity of oxygen it contains, the more alkaline does the watery liquid become. Thus the gas-liquor is distinctly alkaline, and contains a considerable quantity of ammonia, besides other volatile bases. The uses of ammonia are manifold, and nearly our whole supply of this valuable substance is now derived from gas-liquor. The presence of ammonia in this liquor is accounted for when it is known that this compound is a gas composed of nitrogen and hydrogen. It has already been explained that coal contains from one to two per cent. of nitrogen, and during the process of distillation about one-fifth of this nitrogen is converted into ammonia, the remainder being converted partly into other bases, while a small quantity remains in the coke. Ammonia, the "volatile alkali" of the old chemists, and its salts are of importance in pharmacy, but the chief use of this compound is to supply nitrogen for the growth of plants. Plants must have nitrogen in some form or another, and as they cannot assimilate it _directly_ from the atmosphere where it exists in the free state, some suitable nitrogen compound must be supplied to the soil. It is possible that certain leguminous plants may derive their nitrogen from the atmosphere through the intervention of micro-organisms, which appear capable of fixing free nitrogen and of supplying it to the plant upon whose roots they flourish. But this is second-hand nitrogen so far as concerns the plant. It is true also that the atmosphere contains small traces of ammonia and acid oxides of nitrogen, which are dissolved by rain and snow, and thus get washed down into the soil. These are the natural sources of plant nitrogen. But in agricultural operations, where large crops have to be raised as rapidly as possible, some additional source of nitrogen must be supplied, and this is the object of manuring the soil. A manure, chemically considered, is a mixture of substances capable of supplying the necessary nitrogenous and mineral food for the nourishment of the growing plant. The ordinary farm or stable manure contains decomposing nitrogenous organic matter, in which the nitrogen is given off as ammonia, and thus furnishes the soil with which it is mixed with the necessary fertilizer. But the supply of this manure is limited, and we have to fall back upon gas-liquor and native nitrates to meet the existing wants of the agriculturist. Important as is ammonia for the growth of vegetation, it is not in this form that the majority of plants take up their nitrogen. Soluble nitrates are, in most cases, more efficient fertilizers than the salts of ammonia, and the ammonia which is supplied to the soil is converted into nitrates therein before the plant can assimilate the nitrogen. The oxidation of ammonia into nitric acid takes place by virtue of a process called "nitrification," and there is very good reason for believing that this transformation is the work of a micro-organism present in the soil. The gas liquor thus supplies food to a minute organism which converts the ammonia into a form available for the higher plants. Some branches of agriculture--such as the cultivation of the beet for sugar manufacture--are so largely dependent upon an artificial source of nitrogen, that their very existence is bound up with the supply of ammonia salts or other nitrogenous manures. The relationship between the manufacture of beet-sugar and the distillation of coal for the production of gas is thus closer than many readers will have imagined; for while the supply of native guano or nitrate is uncertain, and its freight costly on account of the distance from which it has to be shipped, the sulphate of ammonia from gas-liquor is always at hand, and available for the purposes of fertilization. Then again, there are other products of industrial value which are associated with ammonia, such, for example, as ammonia-alum and caustic soda. This last is one of the most important chemical compounds manufactured on a large scale, and is consumed in enormous quantities for the manufacture of paper and soap, and other purposes. Salts of this alkali are also essential for glass making. Of late years a method for the production of caustic soda has been introduced which depends upon the use of ammonia, and as this process is proving a formidable rival to the older method of alkali manufacture, it may be said that such indispensable articles as paper, soap, and glass are now to some extent dependent upon gas-liquor, and may in course of time become still more intimately connected with the manufacture of coal-gas. But quantitative statements must be given in order to bring home to general readers the actual value of the small percentage of nitrogen present in coal. Thus it has been estimated, that one ton of coal gives enough ammonia to furnish about 30 lbs. of the crude sulphate. The present value of this salt is roughly about £12 per ton. The ten million tons of coal distilled annually for gas making would thus give 133,929 tons of sulphate, equal in money value to £1,607,148, supposing the whole of the ammonia to be sold in this form. To this may be added the ammonia obtained during the distillation of shale and the carbonization of coal for coke, the former source furnishing about 22,000 tons, and the latter about 2500 tons annually. Small as is the legacy of nitrogen bequeathed to us from the Carboniferous period, we see that it sums up to a considerable annual addition to our industrial resources. The three products resulting from the distillation of coal--viz. the gas, ammoniacal-liquor, and coke--having now been made to furnish their tale, we have next to deal with the tar. In the early days of gas manufacture this black, viscid, unsavoury substance was in every sense a waste product. No use had been found for it, and it was burnt, or otherwise disposed of. No demand for the tar existed which could enable the gas manufacturers to get rid of their ever-increasing accumulation. Wood-tar had previously been used as a cheap paint for wood and metal-work, and it was but a natural suggestion that coal-tar should be applied to the same purposes. It was found that the quality of the tar was improved by getting rid of the more volatile portions by boiling it in open pans; but this waste--to say nothing of the danger of fire--was checked by a suggestion made by Accum in 1815, who showed that by boiling down the tar in a still instead of in open pans the volatile portions could be condensed and collected, thus furnishing an oil which could be used by the varnish maker as a substitute for turpentine. A few years later, in 1822, the distillation of tar was carried on at Leith by Drs. Longstaff and Dalston, the "spirit" being used by Mackintosh of Glasgow for dissolving india-rubber for the preparation of that waterproof fabric which to this day bears the name of the original manufacturer. The residue in the still was burnt for lamp-black. Of such little value was the tar at this time that Dr. Longstaff tells us that the gas company gave them the tar on condition that they removed it at their own expense. It appears also that tar was distilled on a large scale near Manchester in 1834, the "spirit" being used for dissolving the residual pitch so as to make a black varnish. But the production of gas went on increasing at a greater rate than the demand for tar for the above-mentioned purposes, and it was not till 1838 that a new branch of industry was inaugurated, which converted the distillation of this material from an insignificant into an important manufacture. In that year a patent was taken out by Bethell for preserving timber by impregnating it with the heavy oil from coal-tar. The use of tar for this purpose had been suggested by Lebon towards the end of the last century, and a patent had been granted in this country in 1836 to Franz Moll for this use of tar-products. But Bethell's process was put into a working form by the great improvements in the apparatus introduced by Bréant and Burt, and to the latter is due the credit of having founded an industry which is still carried on by Messrs. Burt, Bolton and Haywood on a colossal scale. The "pickling" or "creosoting" of timber is effected in an iron cylindrical boiler, into which the timber is run; the cylinder being then closed the air is pumped out, and the air contained in the pores of the wood thus escapes. The creosoting oil, slightly warmed, is then allowed to flow into the boiler, and thus penetrates into the pores of the wood, the complete saturation of which is insured by afterwards pumping air into the cylinder and leaving the timber in the oil for some hours under a pressure of 8 to 10 atmospheres. All timber which is buried underground, or submerged in water, is impregnated with this antiseptic creosote in order to prevent decay. It will be evident that this application of tar-products must from the very commencement have had an enormous influence upon the distillation of tar as a branch of industry. Consider the miles of wooden sleepers over which our railways are laid, and the network of telegraph wires carried all over the country by wooden poles, of which the ends are buried in the earth. Consider also the many subaqueous works which necessitate the use of timber, and we shall gain an idea of the demand for heavy coal-tar oil created by the introduction of Bréant's process. Under the treatment described a cubic foot of wood absorbs about a gallon of oil, and by far the largest quantity of the tar oils is consumed in this way at the present time. Now in the early days of timber-pickling the lighter oils of the tar, which first come over on distillation, and which are too volatile for the purpose of creosoting, were in much about the same industrial position as the tar itself before its application as a timber preservative. The light oil had a limited use as a solvent for waterproofing and varnish making, and a certain quantity was burnt as coal-tar naphtha in specially constructed lamps, the invention of the late Read Holliday of Huddersfield, whose first patent was taken out in 1848 (see Fig. 4). Up to this time, be it remembered, that chemists had not found out what this naphtha contained. But science soon laid hands on the materials furnished by the tar-distiller, and the naphtha was one of the first products which was made to reveal the secret of its hidden treasures to the scientific investigator. From this period science and industry became indissolubly united, and the researches of chemists were carried on hand-in-hand with the technical developments of coal-tar products. [Illustration: FIG. 4.--Read Holliday's lamp for burning light coal-tar oils. The oil is contained in the cistern _c_, from whence it flows down the pipe, when the stopcock is opened, into the burner _a_. Below the burner is a little cup, in which some of the oil is kept burning, and the heat from this flame volatilizes the oil as it flows down the pipe, the vapour thus generated issuing from the jets in the burner and there undergoing ignition. The burner and cup are shown on an enlarged scale at _a_ in the lower figure.] In 1825 Michael Faraday discovered a hydrocarbon in the oil produced by the condensation of "oil gas"--an illuminating gas obtained by the destructive distillation of oleaginous materials. This hydrocarbon was analysed by its illustrious discoverer, and named in accordance with his results "bicarburet of hydrogen." In 1834 the same hydrocarbon was obtained by Mitscherlich by heating benzoic acid with lime, and by Péligot by the dry distillation of calcium benzoate. For this reason the compound was named "benzin" by Mitscherlich, which name was changed into "benzol" by Liebig. In this country the hydrocarbon is known at the present time as benzene. Twenty years after Faraday's discovery, viz. in 1845, Hofmann proved the existence of benzene in the light oils from coal-tar, and in 1848 Hofmann's pupil, Mansfield, isolated considerable quantities of this hydrocarbon from the said light oils by fractional distillation. At the time of these investigations no great demand for benzene existed, but the work of Hofmann and Mansfield prepared the way for its manufacture on a large scale, when, a few years later, the first coal-tar colouring-matter was discovered by our countryman, W. H. Perkin. It is always of interest to trace the influence of scientific discovery upon different branches of industry. As soon as it had been shown that benzene could be obtained from coal-tar, the nitro-derivative of this hydrocarbon--_i.e._ the oily compound produced by the action of nitric acid upon benzene--was introduced as a substitute for bitter almond oil under the name of "essence of mirbane." Nitrobenzene has an odour resembling that of bitter almond oil, and it is still used for certain purposes where the latter can be replaced by its cheaper substitute, such as for the scenting of soap. Although the isolation of benzene from coal-tar gave an impetus to the manufacture of nitrobenzene, no use existed for the latter beyond its very limited application as "essence of mirbane," and the production of this compound was at that time too insignificant to take rank as an important branch of chemical industry. The year 1856 marks an epoch in the history of the utilization of coal-tar products with which the name of Perkin will ever be associated. In the course of some experiments, having for their object the artificial production of quinine, this investigator was led to try the action of oxidizing agents upon a base known as aniline, and he thus obtained a violet colouring matter--the first dye from coal-tar--which was manufactured under a patent granted in 1858, and introduced into commerce under the name of mauve. A brief sketch of the history of aniline will serve to show how Perkin's discovery gave a new value to the light oils from coal-tar and raised the manufacture of nitrobenzene into an important branch of industry. Thirty years before Perkin's experiments the Dutch chemist Unverdorben obtained (1826) a liquid base by the distillation of indigo, which had the property of forming beautifully crystalline salts, and which he named for this reason "crystallin." In 1834 Runge discovered the same base in coal-tar, although its identity was not known to him at the time, and because it gave a bluish colour when acted upon by bleaching-powder, he called it "kyanol." Again in 1840, by distilling a product obtained by the action of caustic alkalies upon indigo, Fritzsche prepared the same base, and gave it the name of aniline, from the Spanish designation of the indigo plant, "anil," derived from the native Indian word, by which name the base is known at the present time. That aniline could be obtained by the reduction of nitrobenzene was shown by Zinin in 1842, who used sulphide of ammonium for reducing the nitrobenzene, and named the resulting base "benzidam." The following year Hofmann showed that crystallin, kyanol, aniline, and benzidam were all one and the same base. Thus when the discovery of mauve opened up a demand for aniline on the large scale, the labours of chemists, from Unverdorben in 1826 to Hofmann in 1843, had prepared the way for the manufacturer. It must be understood that although Runge had discovered aniline in coal-tar, this is not the source of our present supply, for the quantity is too small to make it worth extracting. A mere trace of aniline is present in the tar ready formed; from the time this base was wanted in large quantities it had to be made by nitrating benzene, and then reducing the nitrobenzene. The light oils of tar distillation rejected by the timber-pickling industry now came to the front, imbued with new interest to the technologist as a source of benzene for the manufacture of aniline. The inauguration of this manufacture, like the introduction of steam locomotion, is connected with a sad catastrophe. Mansfield, who first showed manufacturers how to separate benzene and other hydrocarbons from the light oils of coal-tar, and who devised for this purpose apparatus similar in principle to that used on a large scale at the present time (see Fig. 5), met with an accident which resulted in his death. In the upper part of a house in Holborn in February 1856, this pioneer was carrying on his experiments, when the contents of a still boiled over and caught fire. In his endeavours to extinguish the flames he received the injuries which terminated fatally. Applied science no less than pure science has had its martyrs, and among these Mansfield must be ranked. [Illustration: FIG. 5.--Mansfield's still. R the heating burner, A the body of the still with stopcock, _i_, for running out the contents. B the still-head kept in a cistern, C, of hot water or other liquid. The vapour generated by the boiling of the liquid in A, partly condenses in B, from whence the higher boiling-point portion flows back into the still. The uncondensed vapour passes into the condensing-worm, D, which is kept cool by a stream of water, and from thence flows into the receiver S. By opening _m_ in the side-pipe any higher boiling-point oil condensing in the delivery-pipe can be run back into the still.] The operation of tar-distilling is about as unromantic a process as can be imagined, but it must be briefly described before the subsequent developments of the industry can be appreciated properly. It has already been explained that the tar is a complex mixture of many different substances. These various compounds boil at certain definite temperatures, the boiling-point of a chemical compound being an inherent property. If a mixture of substances boiling at different temperatures is heated in a suitable vessel the compounds distil over, broadly speaking, in the order of their boiling-points. The separation by this process is not absolute, because compounds boiling at a certain temperature have a tendency to bring over with them the vapours of other compounds which boil at a higher temperature. But for practical purposes it will be sufficient to consider that the general tendency is for the compounds of low boiling-point to come over first, then the compounds of higher boiling-point, and finally those of the highest boiling-point. This is the principle made use of by the tar-distiller. The tar-still is a large iron pot provided with a still-head from which the vapours boil out into a coil of iron pipe kept cool in a vessel of water (see Fig. 6). The still is heated by a fire beneath it, and the different portions which condense in the iron coil are received in vessels which are changed as the different fractions of the tar come over. The process is what chemists would call a rough fractional distillation. The first fractions are liquid at ordinary temperatures, and the water in the condenser is kept cold; then, as the boiling-point rises, the fraction contains a hydrocarbon which solidifies on cooling, and the water in the condenser is made hot to prevent the choking up of the coil. Every one of these fractions of coal-tar, from the beginning to the end of the process, has its story to tell--all the chief constituents of the tar separated by this means have by chemical science been converted into useful products. [Illustration: FIG. 6.--Sectional diagram of tar-still with arched bottom. The fireplace is at _i_; the hot gases pass over the bridge _k_ and through _g_ into the flues _h_, _h_. The pipe at _c_ is to supply the still with tar; _a_ is the exit pipe connected with the condenser, and _b_ a man-hole for cleaning out the still. The condenser and bottom pipe for drawing off pitch have been omitted to avoid complication.] It is customary at the present time to collect four distinct fractions from the period when the tar begins to boil quietly, _i.e._ from the point when the small quantity of watery liquor which is unavoidably entangled with the tar has distilled over, by which time the temperature in the still is about 110° C. The small fraction that comes over up to this temperature constitutes what the tar-distiller calls "first runnings." From 110° C. to 210° C. there comes over a limpid inflammable liquid known as "light oil," and this is succeeded by a fraction which shows a tendency to solidify on cooling, owing to the separation of a solid crystalline hydrocarbon known as naphthalene. This last fraction, boiling between 210° C. and 240° C., is known as "carbolic oil," because it contains, in addition to the naphthalene, the chief portion of the carbolic acid present in the tar. From 240° C. to 270° C. there comes over another fraction which shows but little tendency to solidify in the condensing coil, and which is known as "heavy oil," or "creosote oil." From 270° C. up to the end of the distillation there distils a fraction which is viscid in consistency, and has a tendency to solidify on cooling owing to the separation of another crystalline hydrocarbon known as anthracene, and which gives the name of "anthracene oil" to this last fraction. When the latter has been collected there remains in the still the black viscid substance known as pitch, which is obtained of any desired consistency by leaving more or less of the anthracene oil mixed with it, or by afterwards mixing it with the heavy oil from previous distillations. The process carried out in the tar-still thus separates the tar into--(1) First runnings, up to 110° C. (2) Light oil, from 110° to 210° C. (3) Carbolic oil, from 210° to 240° C. (4) Creosote oil, from 240° to 270° C. (5) Anthracene oil, from 270° to pitch. (6) Pitch, left in still. It has already been said that coal-tar is a complex mixture of various distinct chemical compounds. Included among the gases, ammoniacal liquor, and tar, the compounds which are known to be formed by the destructive distillation of coal already reach to nearly one hundred and fifty in number. Of the substances present in the tar, about a dozen are utilized as raw materials by the manufacturer, and these are contained in the fractions described above. The first runnings and light oil contain a series of important hydrocarbons, of which the three first members are known to chemists as benzene, toluene, and xylene, the latter being present in three different modifications. The carbolic oil furnishes carbolic acid and naphthalene, and the anthracene oil the hydrocarbon which gives its name to that fraction. Here we have only half a dozen distinct chemical compounds to deal with, and if we confine our attention to these for the present, we shall be enabled to gain a good general idea of what chemistry has done with these raw materials. The products separated during the processes which have to be resorted to for the isolation of these raw materials have also their uses, which will be pointed out incidentally. Beginning with the first runnings and the light oil, from which the hydrocarbons of the benzene series are separated, we have to make ourselves acquainted with the treatment to which these fractions are submitted by the tar-distiller. The light oil is first distilled from an iron still, similar to a tar-still, and the first portions which come over are added to the oily fraction brought over by the water of the first runnings. The separation of the oil from the water in this last fraction is a simple matter, because the hydrocarbons float as a distinct layer on the water, and do not mix with it. We have at this stage, therefore, four products to consider, viz. 1st, the oil from the first runnings; 2nd, the first portions of the light oil; 3rd, the later portions of the light oil; and 4th, the residue in the still. The first and second are mixed together, and the third is washed alternately with alkali and acid to remove acid and basic impurities, and can then be mixed with the first and second products. The total product is then ready for the next operation. The last portion of the light oil which remains in the still is useless as a source of benzene hydrocarbons, and goes into the heavy oil of the later tar fractions. The process of purification is thus far one of fractional distillation combined with chemical washing. In fact, all the processes of purification to which these oils are submitted are essentially of the same character. The principle of fractional distillation has already been explained sufficiently for our present purpose. The process of washing a liquid may appear mysterious to the uninitiated, but in principle it is extremely simple. If we pour some water into a bottle, and then add some liquid which does not mix with the water--say paraffin oil--the two liquids form distinct layers, the one floating on the other. On shaking the bottle so as to mix the contents, the two liquids form a homogeneous mixture at first, but on standing for a short time separation into two layers again takes place. Now if there was present in the paraffin oil some substance soluble in the oil, but more soluble in water, such as alcohol, we should by the operation described wash the alcohol out of the oil, and when the liquids separated into layers after agitation the watery layer would contain the alcohol. By drawing off the oil or the water the former would then be obtained free from alcohol--it would have been "washed." This operation is precisely what the manufacturer does on a large scale with the coal-tar oils. These oils contain certain impurities of which some are of an acid character and dissolve in alkalies, while others are basic and dissolve in acid. The oil is therefore agitated in a suitable vessel provided with mechanical stirring gear with an aqueous solution of caustic soda, and after separation into layers the alkaline solution retaining the acid impurities is drawn off. Then the oil may be washed with water in the same way to remove the lingering traces of alkali, and then with acid--sulphuric acid or oil of vitriol--which dissolves out basic impurities and certain hydrocarbons not belonging to the benzene series which it is desirable to get rid of. A final washing with water removes any acid that may be retained by the oil. The total product containing the benzene hydrocarbons is put through such a series of washing operations as above described, and is then ready for separation into its constituents by another and more perfect process of fractional distillation. This final separation is effected in a piece of apparatus somewhat complicated in structure, but simple in principle. It is a development on a large scale of the apparatus used by Mansfield in his early experiments. The details of construction are not essential to the present treatment of the subject, but it will suffice to say that the vapours of the boiling hydrocarbons ascend through upright columns, in which the compounds of high boiling-point first condense and run back into the still, while the lower boiling-point compounds do not condense in the columns, but pass on into a separate condenser, where they liquefy and are collected. But even with this rectification we do not get a perfect separation--the hydrocarbons are not perfectly pure from a chemical point of view, although they are pure enough for manufacturing purposes. Thus the first fraction consists of benzene containing a small percentage of toluene, then comes over a mixture containing a larger proportion of toluene, then comes a purer toluene mixed with a small percentage of xylene. The boiling-points of the three hydrocarbons are 81° C., 111° C., and 140° C. respectively; but owing to the nature of fractional distillation, a compound of a certain boiling-point always brings over with it a certain quantity of the compound of higher boiling-point, and that is why the rectifying column effects only a partial separation. Of the hydrocarbons thus separated, benzene and toluene are by far the most important; there is but a limited use for the xylenes at present, and these and the hydrocarbons of higher boiling-point belonging to the same series which distil over between 140° and 150° constitute what is known as "solvent naphtha," because it is used for dissolving india-rubber for waterproofing purposes. The hydrocarbons of still higher boiling-point which remain in the still are used as burning naphtha for lamps. If benzene of a higher degree of purity is required--as it is for the manufacture of certain colouring-matters--the fraction containing this hydrocarbon can be again distilled through the rectifying column, and a large proportion of the toluene thus separated from it. Finally, pure benzene can be obtained by submitting the rectified hydrocarbon to a process of refrigeration in a mixture of ice and salt, when the benzene solidifies to a white crystalline solid, while the toluene does not solidify, and can be drained away from the benzene crystals which liquefy at about 5° C. The account rendered by the technologist with respect to the light oils of the tar is thus a pretty good one. Already we see that benzene, toluene, solvent naphtha, and burning naphtha are separated from them. Even the alkaline and acid washings may be made to surrender their contained products, for the first of these contains a certain quantity of carbolic acid, and the acid contains a strongly smelling base called pyridine, for which there is at present no great demand, but which may one day become of importance. The actual quantity of benzene in tar is a little over one per cent. by weight, and of toluene there is somewhat less. The naphthas are present to the extent of about 35 per cent. Now let us consider some of the transformations which benzene and toluene undergo in the hands of the manufacturing chemist. The production of aniline from benzene by acting upon this hydrocarbon with nitric acid, and then reducing the nitrobenzene, has already been referred to. For this purpose we now heat the nitrobenzene with iron dust and a little hydrochloric (muriatic) acid, and then distil over the aniline by means of a current of steam blown through the still. By a similar process toluene is converted into nitrotoluene, and the latter into toluidine. The large quantity of aniline and toluidine now made has opened up a channel for the use of the waste borings from cast-iron. These are ground to a fine powder under heavy mill-stones, and constitute a most valuable reducing agent, known technically as "iron swarf." The metallic iron introduced in this form into the aniline still is converted into an oxide of iron by the action of the nitrobenzene, and this oxide of iron is used by the gas-maker for purifying the gas from sulphur as already described. When the oxide of iron is exhausted, _i.e._ when it has taken up as much sulphur as it can, it goes to the vitriol-maker to be burnt as a source of this acid. Here we have a waste product of the aniline manufacture utilized for the purification of coal-gas, and finally being made to give up the sulphur, which it obtained primarily from the coal, for the production of sulphuric acid, which is consumed in nearly every branch of chemical industry. Nitrotoluene and toluidine each exist in three distinct modifications, so that it is more correct to speak of the nitrotoluenes and the toluidines; but the explanation of these differences belongs to pure chemical theory, and cannot now be attempted in detail. It must suffice to say that many compounds having the same chemical composition differ in their properties, and are said to be "isomeric," the isomerism being regarded as the result of the different order of arrangement of the atoms within the molecule. Consider a homely illustration. A child's box of bricks contains a certain number of wooden blocks, by means of which different structures can be built up. Supposing all the bricks to be employed for every structure erected, the latter must in every case contain all the blocks, and yet the result is different, because in each structure the blocks are arranged in a different way. The bricks represent atoms, and the whole structure represents a molecule; the structures all have the same ultimate composition, and are therefore isomeric. This will serve as a rough analogy, only it must not be understood that the different atoms of the elements composing a molecule are of different sizes and shapes; on this point we are as yet profoundly ignorant. Now as long ago as 1856, at the time when Perkin began making mauve by oxidizing aniline with bichromate of potash, it was observed by Natanson, that when aniline was heated with a certain oxidizing agent a red colouring-matter was produced. The same fact was observed in 1858 by Hofmann, who used the tetrachloride of carbon as an oxidizing agent. These chemists obtained the red colouring-matter as a by-product; it was formed only in small quantity, and was regarded as an impurity. In the same year, 1858, two French manufacturers patented the production of a red dye formed by the action of chromic acid and other oxidizing agents on aniline, the colouring matter thus made being used for dying artificial flowers. Then, a year later, the French chemist Verguin found that the best oxidizing agent was the tetrachloride of tin, and this with many other oxidizing substances was patented by Renard Frères and Franc, and under their patent the manufacture of the aniline red was commenced on a small scale in France. Finally, in 1860, an oxidizing agent was made use of almost simultaneously by two English chemists, Medlock and Nicholson, which gave a far better yield of the red than any of the other materials previously in use, and put the manufacture of the colouring-matter on quite a new basis. The oxidizing material patented by Medlock and Nicholson is arsenic acid, and their process is carried on at the present time on an enormous scale in all the chief colour factories in Europe, the colouring-matter produced by this means being generally known as fuchsine or magenta. In four years the accidental observation of Natanson and Hofmann, made, be it remembered, in the course of abstract scientific investigation, had thus developed into an important branch of manufacture. A demand for aniline on an increased scale sprung up, and the light oils of coal-tar became of still greater importance. The operations of the tar-distiller had to undergo a corresponding increase in magnitude and refinement; the production of nitrobenzene and necessarily of nitric acid had to be increased, and a new branch of manufacture, that of arsenic acid from arsenious acid and nitric acid, was called into existence. Perkin's mauve prepared the way for the manufacture of aniline, and the discovery of a good process for the production of magenta increased this branch of manufacture to a remarkable extent. Still later in the history of the magenta manufacture, attempts were made, with more or less success, to use nitrobenzene itself as an oxidizing agent, and a process was perfected in 1869 by Coupier, which is now in use in many factories. The introduction of magenta into commerce marks an epoch in the history of the coal-tar colour industry--pure chemistry and chemical technology both profited by the discovery. The brilliant red of this colouring-matter is objected to by modern æstheticism, but the dye is still made in large quantities, its value having been greatly increased by a discovery made about the same time by John Holliday and the Baden Aniline and Soda Company, and patented by the latter in 1877. Magenta is the salt of a base now known as rosaniline, and it belongs therefore to the class of basic colouring-matters. The dyes of this kind are as a group less fast, and have a more limited application than those colouring-matters which possess an acid character, so that the discovery above referred to--that magenta could be converted into an acid without destroying its colouring power by acting upon it with very strong sulphuric acid--opened up a new field for the employment of the dye, and greatly extended its usefulness. In this form the colouring-matter is met with under the name of "acid magenta." It must be understood that the production of magenta from aniline by the oxidizing action of arsenic acid or nitrobenzene is the result of chemical change; the colouring-matter is no more present in the aniline than the latter is contained in the benzene. And just in the same way that the colourless aniline oil by chemical transformation gives rise to the intensely colorific magenta, so the latter by further chemical change can be made to give rise to whole series of different colouring-matters, each consisting of definite chemical compounds as distinct in individuality as magenta itself. Thus in 1860, about the time when the arsenic acid process was inaugurated, two French chemists, Messrs. Girard and De Laire, observed that by heating rosaniline for some time with aniline and an aniline salt, blue and violet colouring-matters were produced. This observation formed the starting-point of a new manufacture proceeding from magenta as a raw material. The production of the new colouring-matters was perfected by various investigators, and a magnificent blue was the final result. But here also the dye was of a basic character, and being insoluble in water had only a limited application, as a spirit bath had to be used for dissolving the substance. In 1862, however, an English technologist, the late E. C. Nicholson, found that by the action of strong sulphuric acid the aniline blue could be rendered soluble in water or alkali, and the value of the colouring-matter was enormously increased by this discovery. The basic and slightly soluble spirit blue was by this means converted into acid blues, which are now made in large quantities, and sold under the names of Nicholson's blue, alkali blue, soluble blue, and other trade designations. There is at the present time hardly any other blue which for fastness, facility of dyeing, and beauty can compete with this colouring-matter introduced by Nicholson as the outcome of the work of Girard and De Laire. Other transformations of rosaniline have yet to be chronicled. In 1862 Hofmann found that by acting upon this base--the base of magenta--with the iodide of methyl, violet colouring-matters were produced, and these were for some years extensively employed under the name of Hofmann's violets. And still more remarkable, by the prolonged action of an excess of methyl iodide upon rosaniline, Keisser found that a green colouring-matter was formed. The latter was patented in 1866, and the dye was for some time in use under the name of "iodine green." The statement that technology profited by the introduction of magenta has therefore been justified. It remains to add, that the tar obtained from one ton of Lancashire coal furnishes an amount of aniline capable of giving a little over half a pound of magenta. The colouring power of the latter will be inferred from the fact, that this quantity would dye 375 square yards of white flannel of a full red colour, and if converted into Hofmann violet by methylation, would give enough colour to dye double this surface of flannel of a deep violet shade. It should be stated also, that during the formation of magenta by the arsenic acid process, there are formed small quantities of other colouring-matters which are utilized by the manufacturer. Among these by-products is a basic orange dye, which was isolated by Nicholson, and investigated by Hofmann in 1862. Under the name of "phosphine" this colouring-matter is still used, especially for the dyeing of leather. Even the spent arsenic acid of the magenta-still has its use. The arsenious acid resulting from the reduction of this arsenic acid is generally obtained in the form of a lime salt after the removal of the magenta by the purifying processes to which the crude product is submitted. From the arsenical waste arsenious acid can be recovered, and converted back into arsenic acid by the action of nitric acid. Quite recently the arsenical residue has been used with considerable success in America as an insecticide for the destruction of pests injurious to agricultural crops. Concurrently with these technical developments of coal-tar products, the scientific chemist was carrying on his investigations. The compounds which science had given to commerce were made on a scale that enabled the investigator to obtain his materials in quantities that appeared fabulous in the early days when aniline was regarded as a laboratory curiosity, and magenta had been seen by only a few chemists. The fundamental problem which the modern chemist seeks to solve is in the first place the composition of a compound, _i.e._ the number of the atoms of the different elements which form the molecule, and in the next place the way in which these atoms are combined in the molecule. Reverting to our former analogy, the first thing to be found is how many different blocks enter into the composition of the structure, and the next thing is to ascertain how the blocks are arranged. When this is done, we are said to know the "constitution" or "structure" of the molecule, and in many cases when this is known we can build up or synthesise the compound by combining its different groups of atoms by suitable methods. The coal-tar industry abounds with such triumphs of chemical synthesis; a few of these achievements will be brought to light in the course of the remaining portions of this work. The chemical investigation of magenta was commenced by Hofmann, whose name is inseparably connected with the scientific development of the coal-tar colour industry. In 1862 he showed that magenta was the salt of a base which he isolated, analysed, and named rosaniline. He established the composition of this base and of the violet and blue colouring-matters obtained from it by the processes already described. In 1864 he made the interesting discovery that magenta is not formed by the oxidation of _pure_ aniline, but that a mixture of aniline and toluidine is essential for the production of this colouring-matter. In fact, the aniline oil used by the manufacturer had from the beginning consisted of a mixture of aniline and toluidine, and at the present time "aniline for red" is made by nitrating a mixture of benzene and toluene and reducing the nitro-compounds. From this work of Hofmann's suggestions naturally arose concerning the "constitution" of rosaniline, and new and fruitful lines of work were opened up. Large numbers of chemists of the greatest eminence pursued the inquiry, but the details of their work, although of absorbing interest to the chemist, cannot be discussed in the present volume. The final touch to a long series of investigations was given by two German chemists, Emil and Otto Fischer, who in 1878 proved the constitution of rosaniline by obtaining from it a hydrocarbon, the parent hydrocarbon from which the colouring-matter is derived. The purely scientific discovery of the Fischers threw a flood of light on the chemistry of magenta, and enabled a large number of colouring-matters related to the latter to be classed under one group, having the parent hydrocarbon as a central type. This hydrocarbon, it may be remarked, is known as triphenylmethane, as it is a derivative of methane, or marsh gas. The blues and violets obtained from rosaniline belong to this group, and so also do certain other colouring-matters which had been manufactured before the Fischers' discovery. In order to carry on the story of the utilisation of aniline, it is necessary to know something about these other colouring-matters which are obtained from it. It has been explained that by the methylation of rosaniline Hofmann obtained violet colouring-matters. Now as rosaniline is obtained by the oxidation of a mixture of aniline and toluidine, it seems but natural that if these bases were methylated first and then oxidized a violet dye would be produced. The French chemist Lauth first obtained a violet colouring-matter by this method in 1861. In 1866 this violet dye was manufactured in France by Poirrier, and it is still made in large quantities, being known under the name of "methyl violet." This colouring-matter, and a bluer derivative of it discovered in 1868, gradually displaced the Hofmann violets, chiefly owing to their greater cheapness of production. We are thus introduced to methylated aniline as a source of colouring-matters, and as the compound in question has many different uses in the coal-tar industry, a few words must be devoted to its technology. Aniline, toluidine, and similar bases can be methylated by the action of methyl iodide, but the cost of iodine is too great to enable this process to be used by the manufacturer. Methyl chloride, however, answers equally well, and this compound, which is a liquid of very low boiling point (-23° C.), is prepared on a large scale from the waste material of another industry, viz. the beet-sugar manufacture. It is interesting to see how distinct industries by chemical skill are made to act and react upon one another. Thus the cultivation of the beet, as already explained, is largely dependent on the supply of ammonia from gas-liquor. During the refining of the beet-sugar, a large quantity of uncrystallisable treacle is separated, and this is fermented for the manufacture of alcohol. When the latter is distilled off there remains a spent liquor containing among other things potassium salts and nitrogenous compounds. This waste liquor, called "vinasse," is evaporated down and ignited in order to recover the potash, and during the ignition, ammonia, tar, gas, and other volatile products are given off. Among the volatile products is a base called trimethylamine, which is a derivative of ammonia; the salt formed by combining trimethylamine with hydrochloric acid when heated gives off methyl chloride as a gas which can be condensed by pressure. Here we have a very pretty cycle of chemical transmigration. The nitrogen of the coal plants, stored up in the earth for ages, is restored in the form of ammonia to the crops of growing beet; the nitrogen is made to enter into the composition of the latter plant by the chemico-physiological process going on, and the nitrogenous compounds removed from the plant and heated to the point of decomposition in presence of the potash (which also entered into the composition of the plant), give back their nitrogen partly in the form of a base from which methyl chloride can be obtained. The latter is then made to methylate a product, aniline, derived indirectly from coal-tar. The utilisation of the "vinasse" for this purpose was made known by Camille Vincent of Paris in 1878. The methylation of aniline can obviously be carried out by the foregoing process only when beet-sugar residues are available. There is another method which is more generally used, and which is interesting as bringing in a distinct branch of industry. The same result can, in fact, be arrived at by heating dry aniline hydrochloride, _i.e._ the hydrochloric acid salt of aniline, with methyl alcohol or wood-spirit in strong metallic boilers under great pressure. This is the process carried on in most factories, and it involves the use of pure methyl alcohol, a branch of manufacture which has been called into existence to meet the requirements of the coal-tar colour maker.[4] This alcohol or wood-spirit is obtained by the destructive distillation of wood, and is purified by a series of operations which do not at present concern us. It must be mentioned that the product of the methylation of aniline, which it is the object of the manufacturer to obtain, is an oily liquid called dimethylaniline, which, by virtue of the chemical transformation, is quite different in its properties to the aniline from which it is derived. By a similar operation, using ethyl alcohol, or spirit of wine, diethylaniline can be obtained, and by heating dry aniline hydrochloride with aniline under similar conditions a crystalline base called diphenylamine is also prepared. Now these products--dimethylaniline, diethylaniline, and diphenylamine--are derived from aniline, and they are all sources of colouring-matters. Methyl-violet is obtained by the oxidation of dimethylaniline by means of a gentle oxidizer; a mixture of bases is not necessary as in the case of the magenta formation. Then in 1866 diphenylamine was shown by Girard and De Laire to be capable of yielding a fine blue by heating it with oxalic acid, and this blue, on account of the purity of its shade, is still an article of commerce. It can be made soluble by the action of sulphuric acid in just the same way as the other aniline blue. Furthermore, by acting with excess of methyl chloride on methyl violet, a brilliant green colouring-matter was manufactured in 1878, which was obviously analogous to the iodine green already mentioned, and which for some years held its own as the only good coal-tar green. These are the dyes--methyl violet and green, and diphenylamine blue--which were in commerce before the discovery of the Fischers, and which this discovery enabled chemists to class with magenta, aniline blue, and Hofmann violet in the triphenylmethane group. Later developments bring us into contact with other dyes of the same class, and with the industrial evolution of the purely scientific idea concerning the constitution of the colouring-matters of this group. Benzene and toluene again form the points of departure. By the action of chlorine upon the vapour of boiling toluene there are obtained, according to the extent of the action of the chlorine, three liquids of use to the colour manufacturer. The first of these is benzyl chloride, the second benzal chloride, and the third benzotrichloride or phenyl chloroform. Benzyl chloride, it may be remarked in passing, plays the same part in organic chemistry as methyl chloride, and enables certain compounds to be benzylated, just in the same way that they can be methylated. The bluer shade of methyl violet, introduced in 1868, and still manufactured, is a benzylated derivative. By the action of benzotrichloride on dimethylaniline in the presence of dry zinc chloride, Oscar Doebner obtained in 1878 a brilliant green colouring-matter which was manufactured under the name of "malachite green." It will be remembered that this was about the time when the Fischers were engaged with their investigations. These last chemists, by virtue of their scientific results, were enabled to show that Doebner's green was a member of the triphenylmethane group, and they prepared the same compound by another method which has enabled the manufacturer to dispense with the use of the somewhat expensive and disagreeable benzotrichloride. The Fischers' method consists in heating dimethylaniline with bitter-almond oil and oxidizing the product thus formed, when the green colouring-matter is at once produced. This method brings the technologist into competition with Nature, and we shall see the result. Benzoic aldehyde or bitter-almond oil is one of the oldest known products of the vegetable kingdom, and has from time to time been made the subject of investigation by chemists since the beginning of the century. It arises from the fermentation of a nitrogenous compound found in the almond, and known as amygdalin, the nature of the fermentative change undergone by this substance having been brought to light by Wöhler and Liebig. The discovery of a green dye, requiring for its preparation a vegetable product which was very costly, compelled the manufacturer to seek another source of the oil. Pure chemistry again steps in, and solves the problem. In 1863 it was known to Cahours that benzal chloride, on being heated with water or alkali, gave benzoic aldehyde, and in 1867 Lauth and Grimaux showed that the same compound could be formed by oxidizing benzyl chloride in the presence of water. It was but a step from the laboratory into the factory in this case, and at the present time the aldehyde is made on a large scale by chlorinating boiling toluene beyond the stage of benzyl chloride, and heating the mixture of benzal chloride and benzotrichloride with lime and water under pressure. By this means the first compound is transformed into benzoic aldehyde, and the second into benzoic acid. This last substance is also required by the colour-maker, as it is used in the manufacture of blue by the action of aniline on rosaniline; without some such organic acid the transformation of rosaniline into the blue is very imperfect. Benzoic acid, like the aldehyde, is a natural product which has long been known. It was obtained from gum benzoïn at the beginning of the seventeenth century, and its preparation from this source was described by Scheele in 1755. The same chemist afterwards found it in urine, and from these two sources, the one vegetable and the other animal, the acid was formerly prepared. Its relationship to benzene has already been alluded to in connection with the history of that hydrocarbon. It will be remembered that by heating this acid with lime Mitscherlich obtained benzene in 1834. In one operation, therefore, setting out from toluene, we make these two natural products, the aldehyde and acid, which are easily separable by technical processes. The wants of the technologist have been met, and he has been enabled to compete successfully with Nature, for he can manufacture these products much more cheaply than when he had to depend upon bitter almonds or gum benzoïn. The synthetical bitter-almond oil is chemically identical with that from the plant. Besides its use for the manufacture of colouring-matters, it is employed for flavouring purposes and in perfumery, this being the first instance of a coal-tar perfume which we have had occasion to mention. The odour in this case, it must be remembered, is that of the actual compound which imparts the characteristic taste and smell to the almond; it is not the result of substituting a substance which has a particular odour for another having a similar odour, as is the case with nitrobenzene, which, as already mentioned, is used in large quantities under the name of "essence of mirbane," for imparting an almond-like smell to soap. The introduction of malachite green marks another epoch in the history of the technology of the triphenylmethane colours. The action between benzoic aldehyde and other bases analogous to dimethylaniline was found to be quite general, and the principle was extended to diethylaniline and similarly constituted bases. Various green dyes--some of them acids formed by the action of sulphuric acid on the colour base--are now manufactured, and many other colouring-matters of the same group are synthesised by the benzoic aldehyde process. One other development of this branch of manufacture has yet to be recorded. The new departure was made in 1883 by Caro and Kern, who patented a process for the synthesis of colouring-matters of this group. In this synthesis a gas called phosgene is used, the said gas having been discovered by John Davy in 1811, who gave it its name because it is formed by the direct union of chlorine and carbon monoxide under the influence of sunlight. Caro and Kern's process is the first technical application of Davy's compound. By the action of phosgene on dimethylaniline and analogous bases in the presence of certain compounds which promote the chemical interaction, a number of basic colouring-matters of brilliant shades of violet ("crystal violet") and blue ("Victoria blue," "night blue") are produced, these being all members of the triphenylmethane group. One of these dyes is a fine basic yellow known as "auramine," which is a derivative of diphenylmethane. TAR. (Light oil) | | | | ---------------- -------- | | / Benzyl chloride Benzene Toluene { Benzal chloride } | | | \ Benzotrichloride}<- | | ------------ | Aniline-> Magenta (and Phosphine)<-Toluidine | | / \ | \ | | / \ | \ ---Benzoic acid and<- Dimethylaniline Diphenylamine | \ | Benzoic aldehyde | | | \ | / | | | Aniline Blues: / | | Hofmann Violet Nicholson and / | | and Iodine Green Soluble / | Diph. Blue / | / ------------------------------------------------ / | | | / Crystal Violet, Methyl Violet | / Auramine, & and Green Malachite other Phosgene dyes Green series From benzene and toluene alone about forty distinct colouring-matters of the rosaniline group are sent into commerce. The relationship of those compounds to each other and to their generating substances is not easy to grasp by those to whom the facts are presented for the first time. The scheme on page 107 shows these relationships at a glance. The colouring-matters derived from these two hydrocarbons are far from being exhausted. During the oxidation of aniline for the production of mauve--which colouring-matter, it may be mentioned, is no longer made--a red compound is formed as a by-product. This was isolated by Perkin in 1861, and studied scientifically by Hofmann and Geyger, who established its composition in 1872, the dye being at that time manufactured under the name of "saffranine." It appears to have been first introduced about 1868. The conditions of formation of this dye were at first imperfectly understood, but the problem was attacked by chemists and technologists, and the first point of importance resulting from their work was that saffranine was derived from one of the toluidines present in the commercial aniline. To record the various steps in this chapter of industrial chemistry would take us beyond the scope of the present work. In addition to the chemists named, Caro, Bindschedler, and others contributed to the technology, while the scientific side of the matter was first taken up by Nietzki in 1877, by Otto Witt in 1878, and by Bernthsen in 1886. It is to the work of these chemists, and especially to that of Witt, that we owe our present knowledge of the constitution of this and allied colouring-matters. Space will not admit of our traversing the ground, although to chemists it is a line of investigation full of interest; it will be sufficient to say that by 1886 these investigators had accomplished for these colouring-matters what the Fischers had done for the rosaniline group--they established their constitution, and showed that they were derivatives of diphenylamine, containing two nitrogen atoms joined together in a particular way. The parent-substance from which these compounds are derived is known at the present time as "azine" (French, azote = nitrogen), and the dyes belong accordingly to the azine group. The first coal-tar colouring-matter, Perkin's mauve, is a member of this class. The azine dyes are basic, and mostly of a red or pink shade; they are somewhat fugitive when exposed to light, but possess a certain value on account of their affinity for cotton, and the readiness with which they can be used in admixture with other colouring-matters. Some of the best known are made by oxidizing certain derivatives of aniline or toluidine, in the presence of these or analogous bases. To make this intelligible a little more chemistry is necessary. Aniline is a derivative of benzene in which one atom of hydrogen is replaced by the residue of ammonia. Ammonia is composed of one atom of nitrogen and three atoms of hydrogen; benzene is composed of six atoms of carbon and six of hydrogen. If one atom of hydrogen is supposed to be withdrawn from ammonia, there remains a residue called the amido-group, and if we imagine this group to be substituted for one of the hydrogen atoms in benzene, we have an amido-derivative, _i.e._ amidobenzene or aniline. Similarly, the toluidines are amidotoluenes. If two hydrogen atoms in benzene or toluene are replaced by two amido-groups, we have diamidobenzenes and diamidotoluenes, which are strongly basic substances, capable of existing in several isomeric modifications. Certain of these diamido-compounds when oxidized in the presence of a further quantity of aniline, toluidine, and such amido-compounds, give rise to unstable blue products, which readily become transformed into red dyes of the azine group. Some azine dyes are produced by another method, which is instructive because it brings us into contact with a derivative of dimethylaniline which figures largely in the coal-tar colour industry. By the action of nitrous acid on this base, there is produced a compound known as nitrosodimethylaniline, which was discovered by Baeyer and Caro in 1874, and which contains the residue of nitrous acid in place of one atom of hydrogen. The residue of nitric acid which replaces hydrogen in benzene is the nitro-group, and the compound is nitrobenzene. The analogy with nitrous acid will therefore be sufficiently understood--the residue of this acid is the nitroso-group, and compounds containing this group are nitroso-derivatives. In 1879, Otto Witt found that the nitroso-group in nitrosodimethylaniline acted as an oxidizing group, and enabled this compound to act upon certain diamido-derivatives of benzene and toluene, with the formation of unstable blue compounds, which on heating the solution changed into red colouring-matters of the azine group. This process soon bore fruit industrially, and azines of a red, violet, and blue shade were introduced under the names of neutral red, violet, and blue, Basle blue, &c., some of these surviving at the present time. We have now to turn to another chapter in the history of dimethylaniline. In 1876, Lauth discovered a new colour test for one of the diamidobenzenes. By heating this base with sulphur, and oxidizing the product, a violet colouring-matter was formed, and the same compound was produced by oxidizing the base in an aqueous solution in the presence of sulphuretted hydrogen. Lauth's violet was never manufactured in quantity because the yield is small; but in the hands of Dr. Caro the work of Lauth bore fruit in another direction. Instead of using the diamidobenzene, Caro used its dimethyl-derivative, and by this means obtained a splendid blue dye, which was introduced under the name of "methylene blue." Here again we find scientific research reacting on technology. A few words of chemical explanation will make this manufacture intelligible. By the action of reducing agents on nitro and nitroso-compounds, the nitro and nitroso-group become converted into the amido-group. Thus when nitrobenzene is reduced by iron and an acid we get aniline; similarly when nitrosodimethylaniline is reduced by zinc and an acid we get amidodimethylaniline, and this is the base used in the preparation of methylene blue. By oxidizing this base in the presence of sulphuretted hydrogen, the colouring-matter is formed. Other methods of arriving at the same result were discovered and patented in due course, but the various processes cannot be discussed here. Lauth's violet and methylene blue became the subjects of scientific investigation in 1879 by Koch, and in 1883 a series of brilliant researches were commenced by Bernthsen which extended over several years, and which established the constitution of these compounds. It was shown that they are derivatives of diphenylamine containing sulphur as an essential constituent. The parent-compound is diphenylamine in which sulphur replaces hydrogen, and is therefore known as thiodiphenylamine. It can be prepared by heating diphenylamine with sulphur, and is sometimes called thiazine, because it is somewhat analogous in type to azine. We must therefore credit dimethylaniline with being the industrial generator of the thiazines. The blue is largely used for cotton dyeing, producing on this fibre when properly mordanted an indigo shade. By the action of nitrous acid the blue is converted into a green known as "methylene green." Although the scope of this work admits of our dealing with only a few of the more important groups of colouring-matters, it will already be evident that the chemist has turned benzene and toluene to good account. But great as is the demand for these hydrocarbons for the foregoing purposes, there are other branches of the coal-tar industry which are dependent upon them. It will serve as an answer to those who are continually raising the cry of brilliancy as an offence to æsthetic taste if we consider in the next place a most valuable and important black obtained from aniline. All chemists who studied the action of oxidizing agents, such as chromic acid, on aniline, from Runge in 1834 to Perkin in 1856, observed the formation of greenish or bluish-black compounds. After many attempts to utilize these as colouring-matters, success was achieved by John Lightfoot of Accrington near Manchester in 1863. By using as an oxidizing agent a mixture of potassium chlorate and a copper salt, Lightfoot devised a method for printing and dyeing cotton fabrics, the use of which spread rapidly and created an increased demand for the hydrochloride of aniline, this salt being now manufactured in enormous quantities under the technical designation of "aniline salt." Lightfoot's process was improved for printing purposes by Lauth in 1864, and many different oxidizing mixtures have been subsequently introduced, notably the salts of vanadium, which are far more effective than the salts of copper, and which were first employed by Lightfoot in 1872. In 1875-76 Coquillion and Goppelsröder showed that aniline black is produced when an electric current is made to decompose a solution of an aniline salt, the oxidizing agent here being the nascent oxygen resulting from the electrolysis. In these days when the generation of electricity is so economically effected, this process may become more generally used, and the coal-tar industry may thus be brought into relationship with another branch of applied science. Aniline black is seldom used as a direct colouring-matter; it is generally produced in the fibre by printing on the mixture of aniline salt and oxidizing compounds thickened with starch, &c., and then allowing the oxidation to take place spontaneously in a moist and slightly heated atmosphere. By a similar process, using a dye-bath containing the aniline salt and oxidizing mixture, cotton fibre is easily dyed. The black cannot be used for silk or wool, as the oxidizing materials attack these fibres, but for cotton dyeing and calico printing this colouring-matter has come seriously into competition with the black dyes obtained from logwood and madder. The use of aniline for this purpose, first rendered practicable by Lightfoot, is among the most important of the many wonderful applications of coal-tar products in the tinctorial industry. The year 1863 witnessed the introduction of the first of a new series of colouring-matters which have had an enormous influence both on the art of the dyer as well as in the utilization of tar-products which were formerly of but little value. We can consider the history of some of these colours now, because the earliest of them was produced from aniline. The formation of a yellow compound when nitrous acid acts upon aniline was observed by several chemists prior to the date mentioned. In 1863 the firm of Simpson, Maule and Nicholson manufactured a yellow dye by passing nitrous gas into a solution of aniline in alcohol, and this had a limited application under the name of "aniline yellow." Soon afterwards, viz. in 1866, the firm of Roberts, Dale & Co. of Manchester introduced a brown dye under the name of "Manchester brown"--this compound, which was discovered by Dr. Martius in 1865, having been produced by the action of nitrous acid on one of the diamidobenzenes. Ten years later Caro and Witt discovered an orange colouring-matter belonging to the same class, and the latter introduced the compound into commerce as "chrysoïdine." These three compounds are basic, and the first of them is no longer used as a direct dye because it is fugitive. Chrysoïdine is still used to a large extent, and the brown--now known as "Bismarck brown"--is one of the staple products of the colour manufacturer at the present time. From this fragment of technological history let us now turn to chemical science. The chemist whose name will always be associated with the compounds of this group is the late Dr. Peter Griess of Burton-on-Trent. He commenced his study of the action of nitrous acid on organic bases in 1858, and from that time till the period of his death in 1888, he was constantly contributing to our knowledge of the resulting compounds. In 1866, he and Dr. Martius established the composition of aniline yellow, and the following year Caro and Griess did the same thing for the Manchester brown. In 1877 Hofmann and Witt established the constitution of chrysoïdine, the final outcome of all this work being to show that the three colouring-matters belonged to the same group. The further development of these discoveries has been one of the most prolific sources of new colouring-matters. A brief summary of our present position with respect to this group must now be attempted. When nitrous acid acts upon an amido-derivative of a benzenoid hydrocarbon in the presence of a mineral acid, there is formed a compound in which the amido-group is replaced by a pair of nitrogen atoms joined together in a certain way, which is different to the mode of combination in the azines. This pair of nitrogen atoms is combined on the one hand with the hydrocarbon residue, and on the other with the residue of the mineral acid. The resulting compound is very unstable; its solution decomposes very readily, and generally has to be kept cool by ice. Freezing machines turning out large quantities of ice are kept constantly at work in factories where these produces are made. The latter are known as "diazo-compounds"--Griess's compounds _par excellence_--and they are prepared on a large scale by dissolving a salt of the amido-base, generally the hydrochloride, in water with ice, and adding sodium nitrite. The result is a diazo-salt; aniline, for example, giving diazobenzene chloride, and toluidine diazotoluene chloride. Similarly all amido-derivatives of a benzenoid character can be "diazotised." The importance of this discovery will be seen more fully in the next chapter. At present we are more especially concerned with aniline. The extreme instability of the diazo-salts enables them to combine with the greatest ease with amido-derivatives and with other compounds. The very property which in the early days rendered their investigation so difficult, and which taxed the ingenuity of chemists to the utmost, has now placed these compounds in the front rank as colour generators. When a diazo-salt acts on an amido-derivative there is formed a compound which is more or less unstable, but which readily undergoes transformation under suitable conditions into a stable substance in which two hydrocarbon residues are joined together by the pair of nitrogen atoms. These products are dye-stuffs, known as "azo-colours," and aniline yellow, Bismarck brown, and chrysoïdine are the oldest known technical compounds belonging to the group. The parent substance is "azobenzene," and these three colouring-matters are mono-, di- and triamido-azobenzene respectively. A new phase in the technology of tar-products was entered upon when Witt caused a diazo-salt to act upon diamidobenzene. This was the first industrial application of Griess's discovery. Azobenzene, which was discovered by Mitscherlich in 1834, and azotoluene are now manufactured by reducing nitrobenzene and nitrotoluene with mild reducing agents. These parent compounds are not in themselves colouring-matters, but they are transformed into bases which give rise to a splendid series of azo-dyes, as will be described subsequently. Let it be recorded here that these two compounds are to be added to the list of valuable products obtained from benzene and toluene. And it must also be remembered that the introduction of these azo-colours has necessitated the manufacture on a large scale of sodium nitrite as a source of nitrous acid. Without entering into unnecessary detail it may be stated broadly that this salt is made by fusing Chili saltpetre, which is the nitrate of sodium, with metallic lead, litharge or oxide of lead being obtained as a secondary product. Then again, the manufacture of Bismarck brown requires dinitrobenzene, this being made by the nitration of benzene beyond the stage of nitrobenzene. The brown is made by reducing the dinitrobenzene to diamidobenzene, and then treating a solution of the latter with sodium nitrite and an acid. The azo-colour is formed at once, and no special refrigeration is required in this particular case. It has already been stated that the old aniline yellow of 1863 is no longer used on account of its fugitive character. In 1878 Grässler found that by the action of very strong sulphuric acid this azo-compound could be converted into a sulpho-acid in just the same way that magenta can be converted into acid magenta. Under the name of "acid yellow" this sulpho-acid is now used, not only as a direct yellow colouring-matter, but as a starting-point in the manufacture of other azo-dyes. The use of acid yellow for this last purpose will be dealt with again in the next chapter. There is one other use for aniline yellow which dates from the year of its discovery, when Dale and Caro found that by adding sodium nitrite to aniline hydrochloride and heating the mixture, a blue colouring-matter is produced. The latter was introduced in 1864 under the name of "induline." It was shown subsequently by the scientific researches of several chemists that the blue produced by Dale and Caro's method results from the action of the aniline salt on the aniline yellow, which is formed by the action of the nitrous acid on the aniline and aniline salt. This explanation was proved to be correct in 1872 by Hofmann and Geyger, who prepared the colouring-matter by heating aniline yellow and aniline salt with alcohol as a solvent. These chemists established the composition and gave it the name of "azodiphenyl blue." Later, viz. in 1883, the manufacture was improved by Otto Witt and E. Thomas, and the dye, under the old name of "induline," is now largely manufactured by first preparing aniline yellow and then heating this with aniline and aniline salt. The colouring-matter as formed by this method is basic and insoluble in water; it is made acid and soluble by treatment with sulphuric acid, which converts it into a sulpho-acid. Induline belongs to the sober-tinted colours, and produces a shade somewhat resembling indigo. Closely related thereto is a bluish-grey called "nigrosine," obtained by heating nitrobenzene with aniline, as well as a certain bluish by-product obtained during the formation of magenta, and known as "violaniline." It will be convenient here to pause and reflect upon the great industrial importance of the two coal-tar hydrocarbons upon which we have thus far concentrated our attention. Their uses are by no means exhausted as yet, but they have already been made to account for such a number of valuable products that the reader may find it useful to have the results presented in a collected form. This is given below as a chronological summary-- 1856. Mauve discovered by Perkin; leading to manufacture of aniline. 1860. Arsenic acid process for magenta discovered; leading to manufacture of arsenic acid. 1860. Aniline blue discovered; leading in 1862 to soluble and Nicholson blues. 1861. Methyl violet discovered; manufactured in 1866; leading to a new use of copper salts as oxidizing agents, and to the manufacture of dimethylaniline. 1862. Hofmann violets discovered; leading to manufacture of methyl iodide from iodine, phosphorus, and wood spirit. 1862. Phosphine (chrysaniline) discovered in crude magenta. 1863. Aniline black introduced; leading to a new use for potassium chlorate and copper salts, and to the manufacture of aniline salt. 1863. Aniline yellow introduced, the first azo-colour. 1864. Induline discovered; leading to new use for aniline yellow. 1866. Manchester brown introduced, the second azo-colour; leading to the manufacture of sodium nitrite, and of dinitrobenzene. 1866. Iodine green introduced; leading to further use for methyl iodide. 1866. Diphenylamine blue introduced; leading to manufacture of diphenylamine. 1868. Blue shade of methyl violet introduced; leading to manufacture of benzyl chloride. 1868. Saffranine introduced. 1869. Nitrobenzene process for magenta discovered. 1876. Chrysoïdine introduced, the third azo-colour. 1876. Methylene blue introduced; leading to manufacture of nitrosodimethylaniline. 1877. Acid magenta discovered. 1878. Methyl green introduced; leading to utilization of waste from beet-sugar manufacture. 1878. Malachite green discovered; leading to manufacture of benzoic aldehyde. 1878. Acid yellow discovered; leading to new use for aniline yellow. 1879. Neutral red and allied azines introduced; leading to a new use for nitrosodimethylaniline. 1883. Phosgene colours of rosaniline group introduced; leading to manufacture of phosgene. CHAPTER III. Among the most venerable of natural dye-stuffs is indigo, the substance from which Unverdorben first obtained aniline in 1826. The colouring matter is found in a number of leguminous (see Fig. 7), cruciferous, and other plants, some of which are largely cultivated in India, China, the Malay Archipelago, South America, and the West Indies; while others, such as woad (see Fig. 8), are grown in more temperate European climates. The tinctorial value of these plants was known in India and Egypt long before the Christian era. Egyptian mummy-cloths have been found dyed with indigo. The dye was known to the Greeks and Romans; its use is described by the younger Pliny in his Natural History. Indigo was introduced into Europe about the sixteenth century, but its use was strongly opposed by the woad cultivators, with whose industry the dye came into competition. In France the opposition was strong enough to secure the passing of an act in the time of Henry IV. inflicting the penalty of death upon any person found using the dye. The importance of indigo as an article of commerce is sufficiently known at the present time; more than 8000 tons are produced annually, corresponding in money value to about four million pounds. It is of importance to us as rulers of India to remember that the cultivation and manufacture of indigo is one of the staple industries of that country, from which the European markets derive the greater part of their supply. [Illustration: FIG. 7.--INDIGO PLANT (_Indigofera tinctoria_).] Imagine the industrial revolution which would be caused by the discovery of a process for obtaining indigo synthetically from a coal-tar hydrocarbon, at a price which would compare favourably with that of the natural product. This has not actually been done as yet, but chemists have attempted to compete with Nature in this direction, and the present state of the competition is that the natural product can be cultivated and made more cheaply. Nevertheless the dye can be synthesised from a coal-tar hydrocarbon, and this is one of the greatest achievements of modern chemistry in connection with the tar-products. For more than half a century indigo had been undergoing investigation by chemists, and at length the work culminated in the discovery of a method for producing it artificially. This discovery was the outcome of the labour of Adolf v. Baeyer, who commenced his researches upon the derivatives of indigo in 1866, and who in 1880 secured the first patents for the manufacture of the colouring-matter. It is to the laborious and brilliant investigations of this chemist that we owe nearly all that is at present known about the chemistry of indigo and allied compounds. [Illustration: FIG. 8.--WOAD (_Isatis tinctoria_).] Two methods have been used for the production of artificial indigo--benzal chloride being the starting-point in one of these, and nitrobenzoic aldehyde in the other. The generating hydrocarbon is therefore toluene. By heating benzal chloride with dry sodium acetate there is formed an acid known as cinnamic acid, a fragrant compound which derives its name from cinnamon, because the acid was prepared by the oxidation of oil of cinnamon by Dumas and Peligot in 1834. The acid and its ethers occur also in many balsams, so that we have here another instance of the synthesis of a natural vegetable product from a coal-tar hydrocarbon. The subsequent steps are--(1) the nitration of the acid to produce nitrocinnamic acid; (2) the addition of bromine to form a dibromide of the nitro-acid; (3) the action of alkali on the dibromide to produce what is known as "propiolic acid." The latter, under the influence of mild alkaline reducing agents, is transformed into indigo-blue. The process depending on the use of nitrobenzoic aldehyde is much simpler; but the particular nitro-derivative of the aldehyde which is required is at present difficult to make, and therefore expensive. If the production of this compound could be cheapened, the competition between artificial and natural indigo would assume a much more serious aspect.[5] The light oil of the tar-distiller has now been sufficiently dealt with so far as regards colouring-matters; let us pass on to the next fraction of the tar, the carbolic oil. The important constituents of this portion are carbolic acid and naphthalene. The carbolic oil is in the first place separated into two distinct portions by washing with an alkaline solution. Carbolic acid or phenol belongs to a class of compounds derived from hydrocarbons of the benzene and related series by the substitution of the residue of water for hydrogen. This water-residue is known to chemists as "hydroxyl"--it is water less one atom of hydrogen. Carbolic acid or phenol is hydroxybenzene; and all analogous compounds are spoken of as "phenols." It will be understood in future that a phenol is a hydroxy-derivative of a benzenoid hydrocarbon. Now these phenols are all more or less acid in character by virtue of the hydroxyl-group which they contain. For this reason they dissolve in aqueous alkaline solutions, and are precipitated therefrom by acids. This will enable us to understand the purification of the carbolic oil. The two layers into which this oil separates after washing with alkali are (1) the aqueous alkaline solution of the carbolic acid and other phenols, and (2) the undissolved naphthalene contaminated with oily hydrocarbons and other impurities. Each of these portions has its industrial history. The alkaline solution, on being drawn off and made acid, yields its mixture of phenols in the form of a dark oil from which carbolic acid is separated by a laborious series of fractional distillations. The undissolved hydrocarbon is similarly purified by fractional distillation, and furnishes the solid crystalline naphthalene. The tar from one ton of Lancashire coal yields about 1-1/2 lbs. of carbolic acid, equal to about 1 per cent. by weight of the tar, and about 6-1/4lbs. of naphthalene, so that this last hydrocarbon is one of the chief constituents of the tar, of which it forms from 8 to 10 per cent. by weight. The crude carbolic acid as separated from the alkaline solution is a mixture of several phenolic compounds, and all of these but the carbolic acid itself are gradually removed during the process of purification. Among the compounds associated with the carbolic acid are certain phenols of higher boiling-point, which bear the same relationship to carbolic acid that toluene bears to benzene. That is to say, that while phenol itself is hydroxybenzene, these other compounds, which are called "cresols," are hydroxytoluenes. The cresols form an oily liquid largely used for disinfecting purposes under the designation of "liquid carbolic acid," or "cresylic acid." Carbolic acid is a white crystalline solid possessing strongly antiseptic properties, and is therefore of immense value in all cases where putrefaction or decay has to be arrested. It was discovered in coal-tar by Runge in 1834, and was obtained pure by Laurent in 1840. The gradual establishment of the germ-theory of disease, chiefly due to the labours of Pasteur, has led to a most important application of carbolic acid. Once again we find the coal-tar industry brought into contact with another department of science. Arguing from the view that putrefactive change is brought about by the presence of the germs of micro-organisms ever present in the atmosphere, Sir Joseph Lister proposed that during surgical operations the incised part should be kept under a spray of the germicidal carbolic acid to prevent subsequent mortification. No operation upon portions of the body exposed to the air is at present conducted without this precaution, and many a human life must have been saved by Lister's treatment. To this result the chemist and technologist have contributed, not only by the discovery of the carbolic acid in the tar, but also by the development of the necessary processes for its purification. It should be added that the phenol used must be of the greatest possible purity, and the requirements of the surgeon have been met by chemical and technological skill. From surgery back to colouring-matters, and from these to pharmaceutical preparations and perfumes, are we led in following up the cycles of chemical transformation which these tar-products have undergone in the hands of the technologist, guided by the researches of the chemist. It was observed by Runge in 1834 that crude carbolic acid, on treatment with lime, gave a red, acid colouring-matter which he separated and named "rosolic acid." The observation was followed up, and many other chemists obtained red colouring-matters by the oxidation of crude phenol. In 1859, the colour-giving property of carbolic acid acquired industrial importance from a discovery made by Kolbe and Schmitt in Germany, and by Persoz in France. These chemists found that a good yield of the colouring-matter was obtained by heating phenol with oxalic and sulphuric acids. Under the names of "corallin" and "aurin" the dye-stuff was introduced into commerce, and it is still used for certain purposes, especially for the preparation of coloured lakes for paper-staining. The scientific development of the history of this phenol dye is full of interest, but we can only give it a passing glance. Its interest lies chiefly in the circumstance that it is related to magenta, as was first pointed out by Caro and Wanklyn in 1866. In fact they obtained rosolic acid from magenta by the action of nitrous acid on the latter. We now know that a diazo-salt is first formed under these circumstances, and that the decomposition of this unstable compound in the presence of water gives rise to the rosolic acid. Later researches have shown that by heating rosolic acid with ammonia it is converted into rosaniline. It is also known that the commercial corallin, like the commercial magenta, is a mixture of closely related colouring-matters. The close analogy between magenta and rosolic acid was further shown by Caro in 1866. In the same way that Hofmann found that magenta could not be produced by the oxidation of _pure_ aniline, Caro found that a mixture of phenol and cresol was necessary for the production of rosolic acid when inorganic oxidizers were used. It is indeed this series of investigations upon the phenol dyes--investigations which have been taken part in not only by the chemists named, but also by Graebe, Dale and Schorlemmer, and the Fischers--which led up to the discovery of the constitution of the colouring-matters of the rosaniline group, and, through this, to the far-reaching industrial developments of the discovery as traced in the last chapter. It is evident, from what has been said, that rosolic acid and its related colouring-matters are members of the triphenylmethane group. They are in fact the hydroxylic or acid analogues of the amido-containing or basic dyes of the rosaniline series. In the fragrant blossom of the meadowsweet (_Spiræa ulmaria_) there is contained an acid which is found also as an ether in the oil of wintergreen (_Gautheria procumbens_). This is salicylic acid, a white crystalline compound which has been known to chemists since 1839. In 1860 Kolbe prepared the sodium salt of this acid by passing carbon dioxide gas into phenol in which metallic sodium had been dissolved. It was found subsequently that the same transformation was brought about by heating the dry sodium salt of carbolic acid in an atmosphere of carbon dioxide. This process of Kolbe's is now worked on a manufacturing scale for the preparation of artificial salicylic acid. The acid and its salts and ethers find numerous applications as antiseptics, for the preservation of food, and in pharmacy. Salicylic acid is employed also for the manufacture of certain azo-dyes in a way that it will be very instructive to consider, because the process used may be taken as typical of the general method of preparing such compounds. Solutions of diazo-salts act not only upon amido- and diamido-compounds, as we have seen in the case of aniline yellow and chrysoïdine, but also upon phenols, forming acid azo-colours. This important fact was made known in 1870 by the German chemists Kekulé and Hidegh, but more than six years elapsed before this discovery was taken advantage of by the technologist. Large numbers of these acid azo-dyes are now made from various diazotised amido-compounds combined with different phenols and phenolic acids. The mode of procedure is to diazotise the amido-compound by sodium nitrite and hydrochloric acid in the manner already described, and then add the diazo-salt solution to the phenolic compound dissolved in alkali. The colouring-matter is at once formed. Salicylic acid possesses the characters both of an acid and a phenol. It combines readily with diazo-salts under the circumstances described, and gives rise to azo-dyes, some of which are of technical value. The manufacture of azo-dyes from salicylic acid brings us into contact with certain amidic compounds which figure so largely in the tinctorial industry that they may be conveniently dealt with here. These bases are not azo-compounds themselves, but they are prepared from azo-compounds, viz. from the azobenzene and azotoluene which were spoken about in the last chapter. When these are reduced by acid reducing-agents, they become converted into diamido-bases which are known as benzidine and tolidine respectively. These bases can be diazotised, and as they contain two amido-groups, they form double diazo-salts, _i.e._ tetrazo-salts, which are capable of combining with amido-compounds, or phenols, in the usual way. Thus diazotised benzidine and tolidine combine with salicylic acid to form valuable yellow azo-dyes known as "chrysamines." The dyes of this class obviously contain two azo-groups. Some other uses of carbolic acid must next be considered. Of the colouring-matters derived from coal-tar, none is more widely known than the oldest artificial yellow dye, picric acid. This is a phenol derivative, and was first obtained as long ago as 1771 by Woulfe, by acting upon indigo with nitric acid. Laurent in 1842 was the first to obtain this dye from carbolic acid, from which compound it is still manufactured by acting upon the sulpho-acid with nitric acid. Chemically considered, it is trinitrophenol. It has a very wide application as a dye, and has been used as an explosive agent. A similar colouring-matter was made from cresol in 1869, and introduced under the name of "Victoria yellow," which is dinitro-cresol. Other dyes derived directly or indirectly from phenol will take us back once again to toluene. A new diazotisable diamido-compound was obtained from this last hydrocarbon, and introduced in 1886 by Leonhardt & Co. One of the three isomeric nitrotoluenes furnishes a sulpho-acid which, on treatment with alkali, gives a compound derived from a hydrocarbon known as stilbene, and this, on reduction, is converted into the diamido-compound referred to. The latter, which is a disulpho-acid as well as a diamido-compound, can be diazotised and combined with phenols, &c. The stilbene azo-dyes thus prepared from phenol and salicylic acid, like the chrysamines, are yellow colouring-matters, containing two azo-groups. It is a valuable characteristic of these secondary azo-dyes that they all possess a special affinity for vegetable fibre, and their introduction has exerted a great influence upon the art of cotton-dyeing. We shall have to return to these cotton-dyes again shortly. Before leaving this branch of the subject, the following scheme is presented to show the relationships and inter-relationships of the products thus far dealt with in the present chapter-- Tar | --------------------------------------------------------- | | Light Oil Carbolic Oil / \ /-> Benzal Chloride | / \ / | \ | / \ / | Benzaldehyde | / \ / Cinnamic acid | | Benzene Toluene | Nitrobenzaldehyde | | | Nitrocinnamic acid (+ acetone) | | | | / | | | | / |-----------| Nitrobenzene Nitrotoluene Propiolic acid / | | | | \ | / Phenols Naphthalene | | \ | / | \ | | \ | / | \ | | \ | / | ->Cresols Azobenzene Azotoluene \ Indigo<--/ Phenol | | | Stilbene- | Victoria | | derivative <------------------- yellow | | (Diazotised)\ | \ Benzidine Tolidine Salicylic Picric Corallin \ / acid acid & Aurin (Diazotised) \/ -------------------------------- The existence of naphthalene in coal-tar was made known in 1820 by Garden, who gave it this name because the oils obtained from the tar by distillation went under the general designation of naphtha. The greater portion of the hydrocarbon is contained in the carbolic oil, and is separated and purified in the manner described. A further quantity of impure naphthalene separates out from the next fraction--the creosote oil, and this is similarly washed and purified by distillation. The large quantity of naphthalene existing in tar has already been referred to, but although it is such an important constituent, it was only late in the history of the colour industry that it found any extensive application. In early times it was regarded as a nuisance, and was burnt as fuel, or for the production of a dense soot, which was condensed to form lampblack. It will be remembered that the first of the coal-tar colours made required only the light oils. There are at present only a few direct uses for naphthalene, but one of its applications is sufficiently important to be mentioned. The hydrocarbon is a white crystalline solid melting at 80° C., and boiling at 217° C. Although it has a high boiling-point, it passes readily into vapour at lower temperatures, and the vapour on condensation forms beautiful silvery crystalline scales. This product is "sublimed naphthalene." The vapour of naphthalene burns with a highly luminous flame, and if mixed with coal-gas, it considerably increases the luminosity of the flame. Advantage is taken-of this in the so-called "albo-carbon light," which is the flame of burning coal-gas saturated with naphthalene vapour. The burner is constructed so that the gas passes through a reservoir filled with melted naphthalene kept hot by the flame itself (Fig. 9). [Illustration: FIG. 9.--ALBO-CARBON BURNER.] To appreciate properly the value of those discoveries which have enabled manufacturers to utilize this hydrocarbon, it is only necessary to recall to mind the actual quantity produced in this country. Supposing that ten million tons of coal are used annually for gas-making, and that the 500,000 tons of tar resulting therefrom contain only eight per cent. of naphthalene, there would be available about 40,000 tons of this hydrocarbon annually. Great as have been the recent advancements in the utilization of naphthalene derivatives, there is still a larger quantity of this hydrocarbon produced than is necessary to supply the wants of the colour-manufacturer. From this last statement it will be inferred that naphthalene is now a source of colouring-matters. Let us consider how this has been brought about. The phenols of naphthalene are called naphthols--they bear the same relationship to naphthalene that carbolic acid bears to benzene. Owing to the structure of the naphthalene molecule there are two isomeric naphthols, whereas there is only one phenol. The naphthols--known as alpha- and beta-naphthol, respectively--are now made on a large scale from naphthalene, by heating the latter with sulphuric acid; at a low temperature the alpha sulpho-acid is produced, and at a higher temperature the beta sulpho-acid, and these acids on fusion with caustic soda furnish the corresponding naphthols. Similarly there are two amidonaphthalenes, known as alpha- and beta-naphthylamine respectively. As aniline is to benzene, so are the naphthylamines to naphthalene. The alpha-compound is made in precisely the same way as aniline, viz. by acting upon naphthalene with nitric acid so as to form nitronaphthalene, and then reducing the latter with iron dust and acid. Beta-napthylamine cannot be made in this way; it is prepared from beta-naphthol by heating the latter in presence of ammonia, when the hydroxyl becomes replaced by the amido-group in accordance with a process patented in 1880 by the Baden Aniline Company. The principle thus utilized is the outcome of the scientific work of two Austrian chemists, Merz and Weith. Setting out from the naphthols and naphthylamines we shall be led into industrial developments of the greatest importance. The first naphthalene colour was a yellow dye, discovered by Martius in 1864, and manufactured under the name of "Manchester yellow." It is, chemically speaking, dinitro-alpha-naphthol; but it was not at first made from naphthol, as the latter was not at the time a technical product. It was made from alpha-naphthylamine by the action of nitrous and nitric acids. When a good method for making the naphthol was discovered in 1869, the dye was made from this. The process is just the same as that employed in making picric acid; the naphthol is converted into a sulpho-acid, and this when acted upon by nitric acid, gives the colouring-matter. Manchester yellow is now largely used for colouring soap, but as a dye-stuff it has been improved upon in a manner that will be readily understood. The original colouring-matter being somewhat fugitive, it was found that its sulpho-acid was much faster. This sulpho-acid cannot be made by the direct action of sulphuric acid upon the colouring-matter--as in the case of acid yellow or acid magenta--but by acting upon the naphthol with very strong sulphuric acid, three sulphuric acid residues or sulpho-groups enter the molecule, and then on nitration only two of these are replaced by nitro-groups, and there results a sulpho-acid of dinitro-alpha-naphthol. This was discovered in 1879 by Caro, and introduced as "acid naphthol yellow." It is now one of the standard yellow dyes. The history of another important group of colouring-matters dependent on naphthalene begins with A. v. Baeyer in 1871 and with Caro in 1874. Two products formerly known only as laboratory preparations were called into requisition by this discovery. One of these compounds, phthalic acid, is obtained from naphthalene, and the other, resorcin or resorcinol, is prepared from benzene. Phthalic acid, which was discovered in 1836 by Laurent, is a product of the oxidation of many benzenoid compounds. Chemically considered it is a di-derivative of benzene, _i.e._ two of the hydrogen atoms of benzene are replaced by certain groups of carbon, oxygen, and hydrogen atoms. We have seen how the replacement of hydrogen by an ammonia-residue, amidogen, gives rise to bases such as amidobenzene (aniline), or diamidobenzene. Similarly, the replacement of hydrogen by a water-residue, hydroxyl, gives rise to a phenol. The group of carbon, oxygen, and hydrogen atoms which confers the property of acidity upon an organic compound is a half-molecule of oxalic acid--it is known as the carboxyl group. Thus benzoic acid is the carboxyl-derivative of benzene, and the phthalic acid with which we are now concerned is a dicarboxyl-derivative of benzene. It is related to benzoic acid in the same way that diamidobenzene is related to aniline. Three isomeric phthalic acids are known, but only one of these is of use in the present branch of manufacture. The acid in question, although a derivative of benzene, is most economically prepared by the oxidation of certain derivatives of naphthalene which, when completely broken down by energetic oxidizing agents, furnish the acid. Thus the dinitronaphthol described as Manchester yellow, if heated for some time with dilute nitric acid, furnishes phthalic acid. The latter is made on a large scale by the oxidation of a compound which naphthalene forms with chlorine, and known as naphthalene tetrachloride, because it contains four atoms of chlorine. The other compound, resorcinol, was known to chemistry ten years before it was utilized as a source of colouring-matters. It was originally prepared by fusing certain resins, such as galbanum, asafoetida, &c., with caustic alkali. Soon after its discovery, viz. in 1866, it was shown by Körner to be a derivative of benzene, and from this hint the technical process for the preparation of the compound on a large scale has been developed. Resorcinol is a phenolic derivative of benzene containing two hydroxyl groups; it is therefore related to phenol in the same way that diamidobenzene is related to aniline or phthalic acid to benzoic acid. The relationships can be expressed in a tabular form thus-- Amidobenzene or Aniline. Benzoic acid. Carbolic acid or Phenol. Diamidobenzene. Phthalic acid. Resorcinol. Resorcinol is now made by heating benzene with very strong sulphuric acid so as to convert it into a disulpho-acid, and the sodium salt of the latter is then fused with alkali. As a technical operation it is one of great delicacy and skill, and the manufacture is confined to a few Continental factories. When phthalic acid is heated it loses water, and is transformed into a white, magnificently crystalline substance known as phthalic anhydride, _i.e._ the acid deprived of water. In 1871, A. v. Baeyer, the eminent chemist who subsequently synthesised indigo, published the first of a series of investigations describing the compounds produced by heating phthalic anhydride with phenols. To these compounds he gave the name of "phthaleïns." Baeyer's work, like that of so many other chemists who have contributed to the advancement of the coal-tar colour industry, was of a purely scientific character at first, but it soon led to technological developments. The phthaleïns are all acid compounds possessing more or less tinctorial power. One of the first discovered was produced by heating phthalic anhydride with an acid known as gallic acid, which occurs in vegetable galls, and in the form of tannin in many vegetable extracts which are used by the tanner. The acid is a phenolic derivative of benzoic acid, viz. trihydroxybenzoic acid, and on heating it readily passes into trihydroxybenzene, which is the "pyrogallic acid" or pyrogallol familiar as a photographic developer. The phthaleïn formed from gallic acid and phthalic anhydride really results from the union of the latter with pyrogallol. It is now manufactured under the name of "galleïn," and is largely used for imparting a bluish grey shade to cotton fabrics. By heating galleïn with strong sulphuric acid, it is transformed into another colouring-matter which gives remarkably fast olive-green shades when dyed on cotton fibre with a suitable mordant. This derivative of galleïn is used to a considerable extent under the name of "coeruleïn." These two colouring-matters were the first practical outcome of v. Baeyer's researches. There is another possible development in this direction which chemistry may yet accomplish, and another natural colouring-matter may be threatened, even as the indigo culture was threatened by the later work of the same chemist. There is reason for believing that the colouring-matter of logwood, known to chemists as hæmateïn, is related to or derived in some way from the phthaleïns, and the synthesis of this compound may ultimately be effected. The dye introduced by Caro in 1874 is the brominated phthaleïn of resorcinol. The phthaleïn itself is a yellow dye, and the solutions of its salts show a splendid and most intense greenish yellow fluorescence, for which reason it is called "fluoresceïn." When brominated, the latter furnishes a beautiful red colouring-matter known as "eosin" (Gr. [Greek: eôs], dawn), and the introduction of this gave an industrial impetus to the phthaleïns which led to the discovery of many other related colouring-matters now largely used under various trade designations. About a dozen distinct compounds producing different shades of pink, crimson and red, and all derived from fluoresceïn, are at present in the market, and a few other phthaleïns formed by heating phthalic anhydride with other phenolic compounds instead of resorcinol or pyrogallol (_e.g._ diethylamidophenol), are also of industrial importance. By converting nitrobenzene into a sulpho-acid, reducing to an amido-sulpho-acid, and then fusing with alkali, an amido-phenol is produced, the ethers of which, when heated with phthalic anhydride, give rise to red phthaleïns of most intense colouring power introduced by the Baden Aniline Company as "rhodamines." It remains to point out that the scientific spirit which prompted the investigation of the phthaleïns in the first instance has followed these compounds throughout their technological career. The researches started by v. Baeyer were taken up by various chemists, whose work together with that of the original discoverer has led to the elucidation of the constitution of these colouring-matters. The phthaleïns are members of the triphenylmethane group, and are therefore related to magenta, corallin, malachite green, methyl violet, and the phosgene dyes. It has been said that the phenolic and amidic derivatives of naphthalene, _i.e._ the naphthols and naphthylamines, are of the greatest importance to the colour industry. One of the first uses of alpha-naphthylamine has already been mentioned, viz. for the production of the Manchester yellow, which was afterwards made more advantageously from alpha-naphthol. A red colouring-matter possessing a beautiful fluorescence was afterwards (1869) made from this naphthylamine and introduced as "Magdala red." The latter was discovered by Schiendl of Vienna in 1867. It was prepared in precisely the same way as induline was prepared from aniline yellow. The latter, which is amido-azobenzene, and which is prepared, broadly speaking, by the action of nitrous acid on aniline, has its analogue in amido-azonaphthalene, which is similarly prepared by the action of nitrous acid on naphthylamine. Just as aniline yellow when heated with aniline and an aniline salt gives induline, so amido-azonaphthalene when heated with naphthylamine and a salt of this base gives Magdala red. The latter is, therefore, a naphthalene analogue of induline, as was shown by Hofmann in 1869, and the knowledge of the constitution of the azines which has been gained of late years, enables us to relegate the colouring-matter to this group. This knowledge has also enabled the manufacture to be conducted on more rational principles, viz. by the method employed for the production of the saffranines, as previously sketched. The introduction of azo-dyes, formed by the action of a diazotised amido-compound on a phenol or another amido-compound, marks the period from which the naphthols and naphthylamines rose to the first rank of importance as raw materials for the colour manufacturer. The introduction of chrysoïdine in 1876 was immediately followed by the manufacture of acid azo-dyes obtained by combining diazotised amido-sulpho-acids with phenols of various kinds, or with bases, such as dimethylaniline and diphenylamine. From what has been said in the foregoing portion of this volume, it is evident that all such azo-compounds result from the combination of two things, viz. (1) a diazotised amido-compound, and (2) a phenolic or amidic compound. Either (1) or (2) or both may be a sulpho-acid, and the resulting dye will then also be a sulpho-acid. The first of these colouring-matters derived from the naphthols, was introduced in 1876-77 by Roussin and Poirrier, and by O. N. Witt. They were prepared by converting aniline into a sulpho-acid (sulphanilic acid), diazotising this and combining the diazo-compound with alpha- or beta-naphthol. The compounds formed are brilliant orange dyes, the latter being still largely consumed as "naphthol orange." Other dye-stuffs of a similar nature were introduced by Caro about the same time, and were prepared from the diazotised sulpho-acid of alpha-naphthylamine combined with the naphthols. By this means alpha-naphthol gives what is known as "acid brown," or "fast brown," and beta-naphthol a fine crimson, known as "fast red," or "roccellin." Diazotised compounds combine also with this same sulpho-acid of alpha-naphthylamine (known as naphthionic acid), the first colouring-matter formed in this way having been introduced by Roussin and Poirrier in 1878. It was prepared by diazotising a nitro-derivative of aniline, and acting with the diazo-salt on napthionic acid, and this dye is still used to some extent under the name of "archil substitute." In 1878, the firm of Meister, Lucius & Brüning of Höchst-on-the-Main gave a further impetus to the utilization of naphthalene by discovering two isomeric disulpho-acids of beta-naphthol formed by heating that phenol with sulphuric acid. By combining various diazotised bases with these sulpho-acids, a splendid series of acid azo-dyes ranging in shade from bright orange to claret-red, and to scarlets rivalling cochineal in brilliancy were given to the tinctorial industry. The colouring-matters introduced in 1878 by the Höchst factory under the names of "Ponceaux" of various brands, and "Bordeaux," although to some extent superseded by later discoveries, still occupy an important position. Their discovery not only increased the consumption of beta-naphthol, but also that of the bases which were used for diazotising. These bases are alpha-naphthylamine and those of the aniline series. The intimate relationship which exists between chemical science and technology--a relationship which appears so constantly in the foregoing portions of this work--is well brought out by the discovery under consideration. A little more chemistry will enable this statement to be appreciated. Going back for a moment to the hydrocarbons obtained from light oil, it will be remembered that benzene and toluene have thus far been considered as the only ones of importance to the colour-maker. Until the discovery embodied in the patent specification of 1878, the portions of the light oil boiling above toluene were of no value in the colour industry. Benzene and toluene are related to each other in a way which chemists describe by saying that they are "homologous." This means that they are members of a regularly graduated series, the successive terms of which differ by the same number of atoms of carbon and hydrogen. Thus toluene contains one atom of carbon and two atoms of hydrogen more than benzene. Above toluene are higher homologues, viz. xylene, cumene, &c., which occur in the light oil, the former being related to toluene in the same way that toluene is related to benzene, while cumene again contains one atom of carbon and two atoms of hydrogen more than xylene. This relationship between the members of homologous series is expressed in other terms by saying that the weight of the molecule increases by a constant quantity as we ascend the series. The homology existing among the hydrocarbons extends to all their derivatives. Thus phenol is the lower homologue of the cresols. Also we have the homologous series-- Benzene. Nitrobenzene. Aniline. Toluene. Nitrotoluene. Toluidine. Xylene. Nitroxylene. Xylidine. Cumene. Nitrocumene. Cumidine. The bases of the third column when diazotised and combined with the disulpho-acids of beta-naphthol give a graduated series of dyes beginning with orange and ending with bluish scarlet. Thus it was observed that the toluidine colour was redder than the aniline colour, and it was a natural inference that the xylidine colour would be still redder. At the time of this discovery no azo-colour of a true scarlet shade had been manufactured successfully. A demand for the higher homologues of benzene was thus created, and the higher boiling-point fractions of the light oil, which had been formerly used as solvent naphtha, became of value as sources of colouring-matters. The isolation of coal-tar xylene (which is a mixture of three isomeric hydrocarbons) is easily effected by fractional distillation with a rectifying column, and by nitration and reduction, in the same way as in the manufacture of aniline, xylidine is placed at the disposal of the colour-maker. Xylidine scarlet, although at the time of its introduction the only true azo-scarlet likely to come into competition with cochineal, was still somewhat on the orange side. The cumidine dye would obviously be nearer the desired shade. To meet this want, cumidine had to be made on a large scale, but here practical difficulties interposed themselves. The quantity of cumene in the light oil is but small, and it is associated with other hydrocarbons which are impurities from the present point of view, and from which it is separated only with difficulty. A new source of the base had therefore to be sought, and here again we find chemical science ministering to the wants of the technologist. It was explained in the last chapter that aniline and similar bases can be methylated by heating their dry salts with methyl alcohol under pressure. In this way dimethylaniline is made, and dimethyltoluidine or dimethylxylidine can similarly be prepared. Now it was shown by Hofmann in 1871, that if this operation is conducted at a very high temperature, and under very great pressure, the methyl-alcohol residue, _i.e._ the methyl-group, does not replace the amidic hydrogen or the hydrogen of the ammonia residue, but the methylation takes place in another way, resulting in the formation of a higher homologue of the base started with. For example, by heating aniline salt and pure wood-spirit to a temperature considerably above that necessary for producing dimethylaniline, toluidine is formed. In a similar way, by heating xylidine hydrochloride and methyl alcohol for some time in a closed vessel at about 300° C. cumidine is produced. Hofmann's discovery was thus utilized in 1882, and by its means the base was manufactured, and cumidine scarlet, very similar in shade to cochineal, became an article of commerce. While the development of this branch of the colour industry was taking place by means of the new naphthol disulpho-acids, the cultivation of the fertile field of the azo-dyes was being carried on in other directions. It came to be realized that the fundamental discovery of Griess was capable of being extended to all kinds of amido-compounds. The azo-dyes hitherto introduced had all been derived from amido-compounds containing only one amido-group, and they accordingly contained only one azo-group; they were _primary_ azo-compounds. It was soon found that aniline yellow, which already contains one azo-group as well as an amido-group, could be again diazotised and combined with phenols so as to produce compounds containing two azo-groups, _i.e._ _secondary_ azo-compounds. The sulpho-acid of aniline yellow--Grässler's "acid yellow"--was the first source of azo-dyes of this class. By diazotising this amidoazo-sulpho-acid, and combining it with beta-naphthol, a fine scarlet dye was discovered by Nietzki in 1879, and introduced under the name of "Biebrich scarlet." Two years later a new sulpho-acid of beta-naphthol was discovered by Bayer & Co. of Elberfeld, and this gave rise, when combined with diazotised acid yellow and analogous compounds, to another series of brilliant dyes introduced as "Crocein scarlets." From these beginnings the development of the azo-dyes has been steadily carried on to the present time--year by year new diazotisable amido-compounds or new sulpho-acids of the naphthols and naphthylamines are being discovered, and this branch of the colour industry has already assumed colossal dimensions. An important departure was made in 1884 by Böttiger, who introduced the first secondary azo-colours derived from benzidine. As already explained in connection with salicylic acid, this base and its homologue tolidine form tetrazo-salts, which combine with phenols and amines or their sulpho-acids. One of the first colouring-matters of this group was obtained by combining diazotised benzidine with the sulpho-acid of alpha-naphthylamine (naphthionic acid), and was introduced under the name of "Congo red." Then came the discovery (Pfaff, 1885), that the tetrazo-salts of benzidine and tolidine combine with phenols, amines, &c., in two stages, one of the diazo-groups first combining with one-half of the whole quantity of phenol to form an intermediate compound, which then combines with the other half of the phenol to form the secondary azo-dye. In the hands of the "Actiengesellschaft für Anilinfabrikation" of Berlin this discovery has been utilized for the production of a number of such azo-colours containing two distinct phenols, or amines, or sulpho-acids. Tolidine has been found to give better colouring-matters in most cases than benzidine, and it is scarcely necessary to point out that an increased demand for the nitrotoluene from which this base is made is the necessary consequence of this discovery. It is impossible to attempt to specify by name any of these recent benzidine and tolidine dyes. Their introduction has been the means of finding new uses for the naphthylamines and naphthols and their sulpho-acids, and has thus contributed largely to the utilization of naphthalene. An impetus has been given to the investigation of these sulpho-acids, and chemical science has profited largely thereby. The process by which beta-naphthylamine is prepared from beta-naphthol, already referred to, viz. by heating with ammonia under pressure, has been extended to the sulpho-acids of beta-naphthol, and by this means new beta-naphthylamine sulpho-acids have been prepared, and figure largely in the production of these secondary azo-colours. The latter, as previously stated, possess the most valuable property of dyeing cotton fibre directly, and by their means the art of cotton dyeing has been greatly simplified. The shades given by these colours vary from yellow through orange to bright scarlet, violet, or purple. In addition to benzidine and tolidine, other diazotisable amido-compounds have of late years been pressed into the service of the colour-manufacturer. The derivative of stilbene, already mentioned as being prepared from a sulpho-acid of one of the nitrotoluenes, forms tetrazo-salts, which can be combined with similar or dissimilar phenols, amines, or sulpho-acids, as in the case of benzidine and tolidine. Various shades of red and purple are thus obtained from the diazotised compound, when the latter is combined with the naphthylamines, naphthols, or their sulpho-acids. These, again, are all cotton dyes. The nitro-derivatives of the ethers of phenol and cresol, when reduced in the same way that nitrobenzene and nitrotoluene are reduced to azobenzene and azotoluene, also furnish azo-compounds which, on further reduction, give bases analogous to benzidine and tolidine. Secondary azo-colours derived from these bases and the usual naphthalene derivatives are also manufactured. It is among the secondary azo-dyes that we meet with the first direct dyeing blacks, the importance of which will be realized when it is remembered that the ordinary aniline-black is not adapted for wool dyeing. The azo-blacks are obtained by combining diazotised sulpho-acids of amidoazo-compounds of the benzene or naphthalene series with naphthol sulpho-acids or other naphthalene derivatives. One other series of azo-compounds must be briefly referred to. It has long been known that aniline and toluidine when heated with sulphur evolve sulphuretted hydrogen and give rise to thio-bases, that is, aniline or toluidine in which the hydrogen is partly replaced by sulphur. One of the toluidines treated in this way is transformed into a thiotoluidine which, when diazotised and combined with one of the disulpho-acids of beta-naphthol, forms a red azo-dye, introduced by Dahl & Co. in 1885 as "thiorubin." By modifying the conditions of reaction between the sulphur and the base, it was found in 1887 by Arthur Green, that a complicated thio-derivative of toluidine could be produced which possessed very remarkable properties. The sulpho-acid of the thio-base is a yellow dye, which was named by its discoverer "primuline." Not only is primuline a dye, but it contains an amido-group which can be diazotised. If therefore the fabric dyed with primuline is passed through a nitrite bath, a diazo-salt is formed in the fibre, and on immersing the latter in a second bath containing naphthol or other phenol or an amine, an azo-dye is precipitated in the fibre. By this means there are produced valuable "ingrain colours" of various shades of red, orange, purple, &c. So much for the azo-dyes, one of the most prolific fields of industrial enterprise connected with coal-tar technology. From the introduction of aniline yellow in 1863 to the present time, about 150 distinct compounds of this group have been given to the tinctorial industry. Of these over thirty are cotton dyes containing two azo-groups. Sombre shades, rivalling logwood black, bright yellows, orange-reds, browns, violets, and brilliant scarlets equalling cochineal, have been evolved from the refuse of the gas-works. The artificial colouring-matters have in this last case once again threatened a natural product, and with greater success than the indigo synthesis, for the introduction of the azo-scarlets has caused a marked decline in the cochineal culture. In addition to the azo-colours, there are certain other products which claim naphthalene as a raw material. In 1879 it was found that one of the sulpho-acids of beta-naphthol when treated with nitrous acid readily gave a nitroso-sulpho-acid. A salt of this last acid, containing sodium and iron as metallic bases, was introduced in 1884, under the name of "naphthol green." It is used both as a dye for wool and as a pigment. It may be mentioned here that other nitroso-derivatives of phenols, such as those of resorcinol and the naphthols, under the name of "gambines," are largely used for dyeing purposes, owing to the facility with which they combine with metallic mordants to form coloured salts in the fibre. In this same year, 1879, it was found that by heating nitrosodimethylaniline with beta-naphthol in an appropriate solvent, a violet colouring-matter was formed. This is now manufactured under the name of "new blue," or other designations, and is largely used for producing an indigo-blue shade on cotton prepared with a suitable mordant. The discovery of this colouring-matter gave an impetus to further discoveries in the same direction. It was found that nitrosodimethylaniline reacted in a similar way with other phenolic or with amidic compounds. In 1881 Köchlin introduced an analogous dye-stuff prepared by the action of the same nitroso-compound on gallic acid. Gallocyanin, as it is called, imparts a violet blue shade to mordanted cotton. Other colouring-matters of the same group are in use; some of them, like "new blue," being derivatives of naphthalene. These compounds all belong to a series of which the parent substance is constructed on a type similar to azine; it contains a nitrogen and oxygen atom linking together the hydrocarbon residues, and is therefore known as "oxazine." The researches of Nietzki in 1888 first established the true constitution of the oxazines. Closely related to this group is a colouring-matter introduced by Köchlin and Witt in 1881 under the name of "indophenol." It is prepared in the same way as the azines of the "neutral red" group; viz. by the action of nitrosodimethylaniline on alpha-naphthol, or by oxidizing amidodimethylaniline in the presence of alpha-naphthol. Indophenol belongs to that group of blue compounds formed as intermediate products in the manufacture of azines, as mentioned in connection with "neutral red." But while these intermediate blues resulting from the oxidation of a diamine in the presence of another amine are unstable, and pass readily into red azines, indophenol is stable, and can be used for dyeing and printing in the same way as indigo. The shades which it produces are very similar to this last dye, but for certain practical reasons it has not been able to compete with the natural dye-stuff. The story of naphthalene is summarized in the schemes on pp. 164, 165. Light Oil: Benzene->Disulpho-acid-->Resorcinol.[6] \ \-->Nitrobenzene} } Sulphanilic acid.[7] } Aniline} Amidoazobenzene and sulpho-acid.[7] } } Nitrosodimethylaniline[8] and } } amidodimethylaniline.[8] } Sulpho-acid-->Amidosulpho-acid-->Amidophenol } and ethers.[6] } Azobenzene-->Benzidine.[7] }Toluidines[7] Sulpho-acids.[7] } Amidoazotoluene[7] } and sulpho-acid.[7] } Thiotoluidine and primuline.[7] Toluene-->Nitrotoluenes} Azotoluene-->Tolidine.[7] } Sulpho-acid and Stilbene-derivative.[7] } Sulpho-acids.[7] Xylene->Nitroxylenes->Xylidines[7]} Amidoazoxylene[7] and sulpho-acid.[7] } Cumidine.[7] Carbolic Oil: Phenol-->Nitrophenol and ethers } Azophenol ethers-->Diamidic bases[9] } analogous to benzidine. } Amidophenol[9] and ethers.[9] Cresols-->Nitrocresols and ethers-->Amidocresols[9] and ethers.[9] |>Nitronaphthalene | | | |>[Greek: a]-Naphthylamine[9][10]{Naphthionic acid.[9][10] | {Amidoazonaphthalene | | | {Magdala red. | {Sulpho-acid.[9] | Naphthalene>|>Tetrachloride-->Phthalic acid and anhydride. | | } {Manchester yellow. | }[Greek: a]-Naphthol {Acid naphthol yellow. | } {Sulpho-acids.[10] |>Sulpho-acids} | } {[Greek: b]-Naphthylamine | } { and sulpho-acids.[9][10] | }[Greek: b]-Naphthol{Sulpho-acids & | } { [Greek: b]-naphthylamine | } { sulpho-acids.[9][10] | } {Nitrososulpho-acid and { naphthol green. The fraction of coal-tar succeeding the carbolic oil, viz. the creosote oil, does not at present supply the colour manufacturer with any raw materials beyond the small proportion of naphthalene which separates from it in a very impure condition as "creosote salts." This oil consists of a mixture of the higher homologues of phenol with various hydrocarbons and basic compounds. It is the oil used for creosoting timber in the manner already described; and among its other applications may be mentioned its use as an illuminating agent and as a source of lampblack. In order to burn the oil effectively as a source of light, a specially-constructed burner is used, which is fed by a stream of oil raised from a reservoir at its foot by means of compressed air, which also aids the combustion of the oil. There is produced by this means a great body of lurid flame, which is very serviceable where building or other operations have to be carried on at night (see Fig. 10). For lampblack the oil is simply burnt in iron pans set in ovens, and the sooty smoke conducted into condensing chambers. The creosote oil constitutes more than 30 per cent. by weight of the tar--the time may come when this fraction, like the light oil and carbolic oil, may be found to contain compounds of value to the colour-maker or to other branches of chemical manufacture. [Illustration: FIG. 10.--VERTICAL BURNER FOR HEAVY COAL OIL BY THE LUCIGEN LIGHT CO.] [Illustration: FIG. 11.--THE MADDER PLANT (_Rubia tinctoria_).] The utilization of the next fraction, anthracene oil, is one of the greatest triumphs which applied chemical science can lay claim to since the foundation of the coal-tar colour industry. This discovery dates from 1868, when it was shown by two German chemists, Graebe and Liebermann, that the colouring-matter of madder was derived from the hydrocarbon anthracene. Like indigo, madder may be regarded as one of the most ancient of natural dye-stuffs. It consists of the powdered roots of certain plants of the genus _Rubia_, such as _R. tinctoria_ (see Fig. 11), _R. peregrina_, and _R. munjista_, which were at one time cultivated on an enormous scale in various parts of Europe and Asia. It is estimated that at the time of Graebe and Liebermann's discovery, 70,000 tons of madder were produced annually in the madder-growing countries of the world. At that time we were importing madder into this country at the rate of 15,000 to 16,000 tons per annum, at a cost of £50 per ton. In ten years the importation had fallen to about 1600 tons, and the price to £18 per ton. At the present time the cultivation of madder is practically extinct. There is no better gauge of the practical utility of a scientific discovery than the financial effect. In addition to madder, a more concentrated extract containing the colouring-matter itself was largely used by dyers and cotton printers under the name of "garancin." In 1868 we were importing, in addition to the 15,000 to 16,000 tons of madder, about 2000 tons of this extract annually, at a cost of £150 per ton. By 1878 the importation of garancin had sunk to about 140 tons, and the price had been lowered to £65 per ton. The total value of the imports of madder and garancin in 1868 was over one million pounds sterling; in ten years the value of these same imports had been reduced to about £38,000. Concurrently with this falling off in the demand for the natural colouring-matter, the cultivation of the madder plant had to be abandoned, and the vast tracts of land devoted to this purpose became available for other crops. A change amounting to a revolution was produced in an agricultural industry by a discovery in chemistry. In the persons of two Frenchmen, Messrs. Robiquet and Colin, science laid hands on the colouring-matter of the _Rubia_ in 1826. These chemists isolated two compounds which they named alizarin and purpurin. It is now known that there are at least six distinct colouring-matters in the madder root, all of these being anthracene derivatives. It is known also that the colouring-matters do not exist in the free state in the plant, but in the form of compounds known as glucosides, _i.e._ compounds consisting of the colouring-matter combined with the sugar known as glucose. It may be mentioned incidentally that the colouring-matter of the indigo plant also exists as a glucoside in the plant. During a period of more than forty years from the date of its isolation, alizarin was from time to time submitted to examination by chemists, but its composition was not completely established till 1868, when Graebe and Liebermann, by heating it with zinc-dust, obtained anthracene. This was the discovery which gave the death-blow to the madder culture, and converted the last fraction of the tar-oil from a waste product into a material of the greatest value. The large quantity of madder consumed for tinctorial purposes is indicative of the value of this dye-stuff. It produces shades of red, purple, violet, black, or deep brown, according to the mordant with which the fabric is impregnated. The colours obtained by the use of madder are among the fastest of dyes, the brilliant "Turkey red" being one of the most familiar shades. The discovery of the parent hydrocarbon of this colouring-matter which had been in use for so many ages--a colouring-matter capable of furnishing both in dyeing and printing many distinct shades, all possessed of great fastness--was obviously a step towards the realization of an industrial triumph, viz. the chemical synthesis of alizarin. Within a year of their original observation, this had been accomplished by Graebe and Liebermann, and almost simultaneously by W. H. Perkin in this country. From that time the anthracene, which had previously been burnt or used as lubricating grease, rose in value to an extraordinary extent. In two years a material which could have been bought for a few shillings the ton, rose at the touch of chemical magic to more than two hundred times its former value. Anthracene is a white crystalline hydrocarbon, having a bluish fluorescence, melting at 213° C. and boiling above 360° C. It was discovered in coal-tar by Dumas and Laurent in 1832, and its composition was determined by Fritzsche in 1857. It separates in the form of crystals from the anthracene oil on cooling, and is removed by filtration. The adhering oil is got rid of by submitting the crystals to great pressure in hydraulic presses. Further purification is effected by powdering the crude anthracene cake and washing with solvent naphtha, _i.e._ the mixture of the higher homologues of benzene left after the rectification of the light oil. Another coal-tar product, viz. the pyridine base referred to in the last chapter, has been recently employed for washing anthracene with great success. It is used either by itself or mixed with the solvent naphtha. The anthracene by washing with these solvents is freed from more soluble impurities, and may then contain from 30 to 80 per cent. of the pure hydrocarbon. The washing liquid, which is recovered by distillation, contains, among other impurities dissolved out of the crude anthracene, a hydrocarbon isomeric with the latter, and known as phenanthrene, for which there is at present but little use, but which may one day be turned to good account. The actual amount of anthracene contained in coal-tar corresponds to about 1/2 lb. per ton of coal distilled, _i.e._ from 1/4 to 1/2 per cent. by weight of the tar. Owing to the great value of alizarin and the large quantity of this colouring-matter annually consumed, anthracene is now by far the most important of the coal-tar hydrocarbons. Alizarin, purpurin, and the other colouring-matters of madder are hydroxyl derivatives of a compound derived from anthracene by the replacement of two atoms of hydrogen by two atoms of oxygen. These oxygen derivatives of benzenoid hydrocarbons form a special group of compounds known as quinones. Thus there is quinone itself, or benzoquinone, which is benzene with two atoms of oxygen replacing two atoms of hydrogen. There are also isomeric quinones of the naphthalene series known as naphthaquinones. A dihydroxyl derivative of one of the latter is in use under the somewhat misappropriate name of "alizarin black." With this exception no other quinone derivative is used in the colour industry till we come to the hydrocarbons of the anthracene oil. Phenanthrene forms a quinone which has been utilized as a source of colouring-matters, but these are comparatively unimportant. The quinone with which we are at present concerned is anthraquinone. The latter is prepared by oxidizing the anthracene--previously reduced by sublimation to the condition of a very finely-divided crystalline powder--with sulphuric acid and potassium dichromate. The quinone is purified, converted into a sulpho-acid, and the sodium salt of the latter on fusion with alkali gives alizarin, which is dihydroxy-anthraquinone. It is of interest to note that in this case a monosulpho-acid gives a dihydroxy-derivative. During the process of fusion potassium chlorate is added, by which means the yield of alizarin is considerably increased. In the original process of Graebe and Liebermann, dibromanthraquinone was fused with alkali; but this method was soon improved upon by the discovery of the sulpho-acid by Caro and Perkin in 1869, and from this period the manufacture of artificial alizarin became commercially successful. In addition to alizarin, other anthracene derivatives are of industrial importance. The purpurin, discovered among the colouring-matters of madder in 1826, is a trihydroxy-anthraquinone; it can be prepared by the oxidation of alizarin, as shown by De Lalande in 1874. Isomeric compounds known as "flavopurpurin" and "anthrapurpurin" are also made from the disulpho-acids of anthraquinone by fusion with alkali and potassium chlorate. These two disulpho-acids are obtained simultaneously with the monosulpho-acid by the action of fuming sulphuric acid on the quinone, and are separated by the fractional crystallization of their sodium salts from the monosulpho-acid (which gives alizarin) and from each other. The purpurins give somewhat yellower shades than alizarin. Another trihydroxy-anthraquinone, although not obtained directly from anthracene, must be claimed as a tar-product. It is prepared by heating gallic acid with benzoic and sulphuric acids, or with phthalic anhydride and zinc chloride, and is a brown dye known as "anthragallol" or "anthracene-brown." The anthracene derivative is in this process built up synthetically. A sulpho-acid of alizarin has been introduced for wool dyeing under the name of alizarin carmine, and a nitro-alizarin under the name of alizarin orange. The latter on heating with glycerin and sulphuric acid is transformed into a remarkably fast colouring-matter known as alizarin blue, which is used for dyeing and printing. By heating alizarin blue with strong sulphuric acid, it is converted into alizarin green. The great industry arising out of the laboratory work of two German chemists has influenced other branches of chemical manufacture, and has reacted upon the coal-tar colour industry itself. A new application for caustic soda and potassium chlorate necessitated an increased production of these materials. The first demand for fuming sulphuric acid on a large scale was created by the alizarin manufacture in 1873, when it was found that an acid of this strength gave better results in the preparation of sulpho-acids from anthraquinone. The introduction of this acid into commerce no doubt exerted a marked influence on the production of other valuable sulpho-acids, such as acid magenta in 1877, acid yellow in 1878, and acid naphthol yellow in 1879. The introduction of artificial alizarin has also simplified the art of colour printing on cotton fabrics to such an extent that other colouring-matters, also derived from coal-tar, are largely used in combination with the alizarin to produce parti-coloured designs. The manufacture of one coal-tar colouring-matter has thus assisted in the consumption of others. Artificial alizarin is used in the form of a paste, which consists of the colouring-matter precipitated from its alkaline solution by acid, and mixed with water so as to form a mixture containing from 10 to 20 per cent. of alizarin. The magnitude of the industry will be gathered from the estimate that the whole quantity of anthracene annually made into alizarin corresponds to a daily production of about 65 tons of 10 per cent. paste, of which only about one-eighth is made in this country, the remainder being manufactured on the Continent. The total production of alizarin corresponds in money value to about £2,000,000 per annum. One pound of dry alizarin has the tinctorial power of 90 pounds of madder. Seeing therefore that the raw material anthracene was at one time a waste product, and that the quantity of alizarin produced in the factory corresponds to nearly five pounds of 20 per cent. paste for one pound of anthracene, it is not surprising that the artificial has been enabled to compete successfully with the natural product. The industrial history of anthracene is thus summarized. (See opposite.) Anthracene | Anthraquinone | | } Sulpho-acid (Alizarin carmine) |->Monosulpho-acid-->Alizarin----------} Purpurin | } Nitro-alizarin-->Alizarin blue |->[Greek: a]-Disulpho-acid-->Flavopurpurin | | | |->[Greek: b]-Disulpho-acid-->Anthrapurpurin | Alizarin green. The black, viscid residue left in the tar-still after the removal of the anthracene oil is the substance known familiarly as pitch. From the latter, after removal of all the volatile constituents, there is prepared asphalte, which is a solution of the pitchy residue in the heavy tar-oils from which all the materials used in the colour industry have been removed. Asphalte is used for varnish-making, in the construction of hard pavements, and for other purposes. A considerable quantity of pitch is used in an industry which originated in France in 1832, and which is still carried out on a large scale in that country, and to a smaller extent in this and other tar-producing countries. The industry in question is the manufacture of fuel from coal-dust by moulding the latter in suitable machines with pitch so as to form the cakes known as "briquettes" or "patent fuel." By this means two waste materials are disposed of in a useful way--the pitch and the finely-divided coal, which could not conveniently be used as fuel by itself. From two to three million tons of this artificial fuel are being made annually here and on the Continent. The various constituents of coal-tar have now been made to tell their story, so far as relates to the colouring-matters which they furnish. If the descriptive details are devoid of romance to the general reader, the results achieved in the short period of thirty-five years, dating from the discovery of mauve by Perkin, will assuredly be regarded as falling but little short of the marvellous. Although the most striking developments are naturally connected with the colouring-matters, whose history has been sketched in the foregoing pages, and whose introduction has revolutionized the whole art of dyeing, there are other directions in which the coal-tar industry has in recent times been undergoing extension. Certain tar-products are now rendering good service in pharmacy. Salicylic acid and its salts have long been used in medicine. By distilling a mixture of the dry lime salts of benzoic and acetic acids there is obtained a compound known to chemists as acetophenone, which is used for inducing sleep under the name of hypnone. The acetyl-derivative of aniline and of methylaniline are febrifuges known as "antifebrine" and "exalgine." Ethers of salicylic acid and its homologues, prepared from these acids and phenol, naphthols, &c., are in use as antiseptics under the general designation of "salols." In 1881 there was introduced into medicine the first of a group of antipyretics derived from coal-tar bases of the pyridine series. It has already been explained that this base is removed from the light oil by washing with acid. Chemically considered, it is benzene containing one atom of nitrogen in place of a group consisting of an atom of carbon and an atom of hydrogen. The quantity of pyridine present in coal-tar is very small, and no use has as yet been found for it excepting as a solvent for washing anthracene or for rendering the alcohol used for manufacturing purposes undrinkable, as is done in this country by mixing in crude wood-spirit so as to form methylated spirit. The salts of pyridine were shown by McKendrick and Dewar to act as febrifuges in 1881, but they have not hitherto found their way into pharmacy. The chief interest of the base for us centres in the fact that it is the type of a group of bases related to each other in the same way as the coal-tar hydrocarbons. Thus in coal-tar, in addition to pyridine, there is another base known as quinoline, which is related to pyridine in the same way that naphthalene is related to benzene. Similarly there is a coal-tar base known as acridine, which is found associated with the anthracene, and which is related to quinoline in the same way that anthracene is related to naphthalene. The three hydrocarbons are comparable with the three bases, which may be regarded as derived from them in the same manner that pyridine is derived from benzene-- Benzene ... ... ... Pyridine Naphthalene ... ... Quinoline Anthracene ... ... ... Acridine Some of these bases and their homologues are found in the evil-smelling oil produced by the destructive distillation of bones (Dippel's oil, or bone oil), and the group is frequently spoken of as the pyridine group. The colouring-matter described as phosphine, obtained as a by-product in the manufacture of magenta (p. 94), is a derivative of acridine, and a yellow colouring-matter discovered by Rudolph in 1881, and obtained by heating the acetyl derivative of aniline with zinc chloride, is a derivative of a homologue of quinoline. This dye-stuff, known as "flavaniline," is no longer made; but it is interesting as having led to the discovery of the constitution of phosphine by O. Fischer and Körner in 1884. The antipyretic medicines which we have first to consider are derivatives of quinoline. This base was discovered in coal-tar by Runge in 1834, and was obtained by Gerhardt in 1842 by distilling cinchonine, one of the cinchona alkaloïds, with alkali. Now it is of interest to note that the quinoline of coal-tar is of no more use to the technologist than the aniline; these bases are not contained in the tar in sufficient quantity to enable them to be separated and purified with economical advantage. If the colour industry had to depend upon this source of aniline only, its development would have been impossible. But as chemistry enabled the manufacturer to obtain aniline in quantity from benzene, so science has placed quinoline at his disposal. This important discovery was made in 1880 by the Dutch chemist Skraup, who found that by heating aniline with sulphuric acid and glycerin in the presence of nitrobenzene, quinoline is produced. The nitrobenzene acts only as an oxidizing agent; the amido-group of the aniline is converted into a group containing carbon, hydrogen, and nitrogen, _i.e._ the pyridine group. The discovery of Skraup's method formed the starting-point of a series of syntheses, which resulted in the formation of many products of technical value. In all these syntheses the fundamental change is the same, viz. the conversion of an amidic into a pyridine group. We may speak of the amido-group as being "pyridised" in such processes. Thus alizarin blue, which is formed by heating nitro-alizarin with glycerin and sulphuric acid, results from the pyridisation of the nitro-group. By an analogous method Doebner and v. Miller prepared a homologue of quinoline (quinaldine) in 1881, by the action of sulphuric acid and a certain modification of aldehyde known as paraldehyde on aniline. Quinoline and its homologue quinaldine have been utilized as sources of colouring-matters. A green dye-stuff, known as quinoline green, was formerly made by the same method as that employed for producing the phosgene colours by Caro and Kern's process (p. 106). The phthaleïn of quinaldine was introduced by E. Jacobsen in 1882 under the name of quinoline yellow, a colouring-matter which forms a soluble sulpho-acid by the action of sulphuric acid. To return to coal-tar pharmaceutical preparations. At the present time seven distinct derivatives of quinoline, all formed by pyridising the amido-group in aniline, amido-phenols, &c., are known in medicine under such names as kairine, kairoline, thalline, and thermifugine. The mode of preparation of these compounds cannot be entered into here, Kairine, the first of the artificial alkaloïds, is a derivative of hydroxy-quinoline, which was discovered in 1881 by Otto Fischer. All these quinoline derivatives have the property of lowering the temperature of the body in certain kinds of fevers, and may therefore be considered as the first artificial products coming into competition with the natural alkaloïd, quinine. There is reason for believing that the latter alkaloïd, the most valuable of all febrifuges, is related to the quinoline bases, so that if its synthesis is accomplished--as may certainly be anticipated--we shall have to look to coal-tar as a source of the raw materials. Another valuable artificial alkaloïd, discovered in 1883 by Ludwig Knorr, claims aniline as a point of departure. When aniline and analogous bases are diazotised, and the diazo-salts reduced in the cold with a very gentle reducing agent, such as stannous chloride, there are formed certain basic compounds, containing one atom of nitrogen and one atom of hydrogen more than the original base. These bases were discovered in 1876 by Emil Fischer, and they are known as hydrazines, the particular compound thus obtained from aniline being phenylhydrazine. By the action of this base on a certain compound ether derived from acetic acid, which is known as aceto-acetic ether, there is formed a product termed "pyrazole," and this on methylation gives the alkaloïd in question, which is now well known in pharmacy under the name of "antipyrine." While dealing with this first industrial application of a hydrazine, it must be mentioned that the original process by which Fischer prepared these bases was improved upon by Victor Meyer and Lecco in 1883, who discovered the use of a cold solution of stannous chloride for reducing the diazo-chloride to the hydrazine. By this method the manufacture of phenylhydrazine and other hydrazines is effected on a large scale--all kinds of amido-compounds and their sulpho-acids can be diazotised and reduced to their hydrazines. Out of this discovery has arisen the manufacture of a new class of colouring-matters related to the azo-dyes. The hydrazines combine with quinones and analogous compounds with the elimination of water, the oxygen coming from the quinone, and the hydrogen from the hydrazine. The resulting products are coloured compounds very similar in properties to the azo-dyes, and one of these was introduced in 1885 by Ziegler, under the name of "tartrazine." The latter is obtained by the action of a sulpho-acid of phenylhydrazine on dioxytartaric acid, and is a yellow dye, which is of special interest on account of its extraordinary fastness towards light. Another direction in which coal-tar products have been utilized is in the formation of certain aromatic compounds which occur in the vegetable kingdom. Thus the artificial production of bitter-almond oil from toluene has already been explained. By heating phenol with caustic alkali and chloroform, the aldehyde of salicylic acid, _i.e._ salicylic aldehyde, is formed, and this, on heating with dry sodium acetate and acetic anhydride, passes into _coumarin_, the fragrant crystalline substance which is contained in the Tonka bean and the sweet-scented woodruff. Furthermore, the familiar flavour and scent of the vanilla bean, which is due to a crystalline substance known as vanillin, can be obtained from coal-tar without the use of the plant. The researches of Tiemann and Haarman having shown that vanillin is a derivative of benzene containing the aldehyde group, one hydroxyl- and one methoxy-group, the synthesis of this compound soon followed (Ulrich, 1884). The starting-point in this synthesis is nitrobenzoic aldehyde, so that here again we begin with toluene as a raw material. A mixture of vanillin and benzoic aldehyde when attenuated to a state of extreme dilution in a spirituous solvent, gives the perfume known as "heliotrope." Not the least romantic chapter of coal-tar chemistry is this production of fragrant perfumes from the evil-smelling tar. Be it remembered that these products--which Nature elaborates by obscure physiological processes in the living plant--are no more contained in the tar than are the hundreds of colouring-matters which have been prepared from this same source. It is by chemical skill that these compounds have been built up from their elemental groups; and the artificial products, as in the case of indigo and alizarin, are chemically identical with those obtained from the plant. Among the late achievements in the synthesis of vegetable products from coal-tar compounds is that of juglone, a crystalline substance found in walnut-shell. It was shown by Bernthsen in 1884 that this compound was hydroxy-naphthaquinone, and in 1887 its synthesis from naphthalene was accomplished by this same chemist in conjunction with Dr. Semper. Another recent development in the present branch of chemistry brings a coal-tar product into competition with sugar. In 1879 Dr. Fahlberg discovered a certain derivative of toluene which possessed an intensely sweet taste. By 1884 the manufacture of this product had been improved to a sufficient extent to enable it to be introduced into commerce as a flavouring material in cases where sweetness is wanted without the use of sugar, such as in the food of diabetic patients. Under the name of "saccharin," Fahlberg thus gave to commerce a substance having more than three hundred times the sweetening power of cane-sugar--a substance not only possessed of an intense taste, but not acted upon by ferments, and possessing distinctly antiseptic properties. The future of coal-tar saccharin has yet to be developed; but its advantages are so numerous that it cannot fail to become sooner or later one of the most important of coal-tar products. In cases where sweetening is required without the possibility of the subsequent formation of alcohol by fermentation, saccharin has been used with great success, especially in the manufacture of aërated waters. Its value in medicine has been recognized by its recent admission into the Pharmacopoeia. The remarkable achievements of modern chemistry in connection with coal-tar products do not end with the formation of colouring-matters, medicines, and perfumes. The introduction of the beautiful dyes has had an influence in other directions, and has led to results quite unsuspected until the restless spirit of investigation opened out new fields for their application. A few of these secondary uses are sufficiently important to be chronicled here. In sanitary engineering, for example, the intense colouring power of fluoresceïn is frequently made use of to test the soundness of drains, or to find out whether a well receives drainage from insanitary sources. In photography also coal-tar colouring-matters are playing an important part by virtue of a certain property which some of these compounds possess. The ordinary photographic plate is, as is well known, much more sensitive to blue and violet than to yellow or red, so that in photographing coloured objects the picture gives a false impression of colour intensity, the violets and blues impressing themselves too strongly, and the yellows and reds too feebly. It was discovered by Dr. H. W. Vogel in 1873 that if the sensitive film is slightly tinted with certain colouring-matters, the sensitiveness for yellow and red can be much increased, so that the picture is a more natural representation of the object. Plates thus dyed are said to be "isochromatic" or "orthochromatic," and by their use paintings or other coloured objects can be photographed with much better results than by the use of ordinary plates. The boon thus conferred upon photographic art is therefore to be attributed to coal-tar chemistry. Among the numerous colouring-matters which have been experimented with, the most effective special sensitizers are erythrosin, one of the phthaleïns, quinoline red, a compound related to the same group, and cyanin, a fugitive blue colouring-matter obtained from quinoline in 1860 by Greville Williams. In yet another way has photography become indebted to the tar chemist. Two important developers now in common use are coal-tar products, viz. hydroquinone and eikonogen. The history of these compounds is worthy of narration as showing how a product when once given by chemistry to the world may become applicable in quite unexpected directions. Chloroform is a case in point. This compound was discovered by Liebig in 1831, but its use as an anæsthetic did not come about till seventeen years after its discovery. It was Sir James Simpson who in 1848 first showed the value of chloroform in surgical operations. A similar story can be told with respect to these photographic developers. Towards the middle of the last century a French chemist, the Count de la Garaye, noticed a crystalline substance deposited from the extract of Peruvian bark, then, as now, used in medicine. This substance was the lime salt of an acid to which Vauquelin in 1806 gave the name of quinic acid (_acide quinique_). In 1838 Woskresensky, by oxidizing quinic acid with sulphuric acid and oxide of manganese, obtained a crystalline substance which he called quinoyl. The name was changed to quinone by Wöhler, and, as we have already seen (p. 172), the term has now become generic, indicating a group of similarly constituted oxygen derivatives of hydrocarbons. Hydroquinone was obtained by Caventou and Pelletier by heating quinic acid, but these chemists did not recognize its true nature. It was the illustrious Wöhler who in 1844 first prepared the compound in a state of purity, and established its relationship to quinone. This relationship, as the name given by Wöhler indicates, is that of the nature of a hydrogenised quinone. The compound is readily prepared by the action of sulphurous acid or any other reducing agent on the quinone. It has long been known in photography, that a developer must be of the nature of a reducing agent, either inorganic or organic, and many hydroxylic and amidic derivatives of hydrocarbons come under this category. Thus, pyrogallol, which has already been referred to as a trihydroxybenzene (p. 146), when dissolved in alkali rapidly absorbs oxygen--it is a strong reducing agent, and is thus of value as a developer. But although pyrogallol is a benzene derivative, and could if necessary be prepared synthetically, it can hardly be claimed as a tar product, as it is generally made from gallic acid. Now hydroquinone when dissolved in alkali also acts as a reducing agent, and in this we have the first application of a true coal-tar product as a photographic developer. Its use for this purpose was suggested by Captain Abney in 1880, and it was found to possess certain advantages which caused it to become generally adopted. As soon as a practical use is found for a chemical product its manufacture follows as a matter of course. In the case of hydroquinone, the original source, quinic acid, was obviously out of question, for economical reasons. In 1877, however, Nietzki worked out a very good process for the preparation of quinone from aniline by oxidation with sulphuric acid and bichromate of soda in the cold. This placed the production of quinone on a manufacturing basis, so that when a demand for hydroquinone sprung up, the wants of the photographer were met by the technologist. Eikonogen is another organic reducing agent, discovered by the writer in 1880, and introduced as a developer by Dr. Andresen in 1889. It is an amido-derivative of a sulpho-acid of beta-naphthol, so that naphthalene is the generating hydrocarbon of this substance. The thio-derivative of toluidine described as "primuline" (p. 160), has recently been found by its discoverer to possess a most remarkable property which enables this compound to be used for the photographic reproduction of designs in azo-colours. Diazotised primuline, as already explained, combines in the usual way with amines and phenols to form azo-dyes. Under the influence of light, however, the diazotised primuline is decomposed with the loss of nitrogen, and the formation of a product which does not possess the properties of a diazo-compound. The product of photochemical decomposition no longer forms azo-colours with amines or phenols. If, therefore, a fabric is dyed with primuline, then diazotised by immersion in a nitrite bath, and exposed under a photographic negative, those portions of the surface to which the light penetrates lose the power of giving a colour with amines or phenols. The design can thus be developed by dipping the fabric into a solution of naphthol, naphthylamine, &c. By this discovery another point of contact has been established between photography and coal-tar products. Nor is this the only instance of its kind, for it has also been observed that a diazo-sulpho-acid of one of the xylenes does not combine with phenols to form azo-dyes excepting under the influence of light. A fabric can therefore be impregnated with the mixture of diazo-sulpho-acid and naphthol, and exposed under a design, when the azo-colour is developed only on those portions of the surface which are acted upon by light. The last indirect application of coal-tar colouring-matters to which attention must be called is one of great importance in biology. The use of these dyes as stains for sections of animal and vegetable tissue has long been familiar to microscopists. Owing to the different affinities of the various components of the tissue for the different colouring-matters, these components are capable of being differentiated and distinguished by microscopical analysis. Furthermore, the almost invisible organisms which in recent times have been shown to play such an important part in diseases, have in many cases a special affinity for particular colouring-matters, and their presence has been revealed by this means. The micro-organism of tubercle, for example, was in this way found by Koch to be readily stained by methylene blue, and its detection was thus rendered possible with certainty. Many of the dyes referred to in the previous pages have rendered service in a similar way. To the pure utilitarian such an application of coal-tar products will no doubt compensate for any defects which they may be supposed to possess from the æsthetic point of view.[11] From a small beginning there has thus developed in a period of five-and-thirty years an enormous industry, the actual value of which at the present time it is very difficult to estimate. We shall not be far out if we put down the value of the coal-tar colouring-matters produced annually in this country and on the Continent at £5,000,000 sterling. The products which half a century or so ago were made in the laboratory with great difficulty, and only in very small quantities, are now turned out by the hundredweight and the ton.[12] To achieve these results the most profound chemical knowledge has been combined with the highest technological skill. The outcome has been to place at the service of man, from the waste products of the gas-manufacturer, a series of colouring-matters which can compete with the natural dyes, and which in many cases have displaced the latter. From this source we have also been provided with explosives such as picric acid; with perfumes and flavouring materials like bitter-almond oil and vanillin; with a sweetening principle like saccharin--compared with which the product of the sugar-cane is but feeble; with dyes which tint the photographic film, and enable the most delicate gradations of shade to be reproduced; with developers such as hydroquinone and eikonogen; with disinfectants which contribute to the healthiness of our towns; with potent medicines which rival the natural alkaloïds; and with stains which reveal the innermost structure of the tissues of living things, or which bring to light the hidden source of disease. Surely if ever a romance was woven out of prosaic material it has been this industrial development of modern chemistry. But although the results are striking enough when thus summed up, and although the industrial importance of all this work will be conceded by those who have the welfare of the country in mind, the paths which the pioneers have had to beat out can unfortunately be followed but by the few. It is not given to our science to strike the public mind at once with the magnitude of its achievements, as is the case with the great works of the engineer. Nevertheless the scientific skill which enables a Forth Bridge to be constructed for the use of the travelling public of this age--marvellous as it may appear to the uninstructed--is equalled, if not surpassed, by the mastery of the intricate atomic groupings which has enabled the chemist to build up the colouring-matters of the madder and indigo plants. A great industry needs no excuse for its existence provided that it supplies something of use to man, and finds employment for many hands. The coal-tar industry fulfils these conditions, as will be gathered from the foregoing pages. If any further justification is required from a more exalted standpoint than that of pure utilitarianism it can be supplied. It is well known to all who have traced the results of applying any scientific discovery to industrial purposes, that the practical application invariably reacts upon the pure science to the lasting benefit of both. In no department of applied science is this truth more forcibly illustrated than in the branch of technology of which I have here attempted to give a popular account. The pure theory of chemical structure--the guiding spirit of the modern science--has been advanced enormously by means of the materials supplied by and resulting from the coal-tar industry. The fundamental notion of the structure of the benzene molecule marks an epoch in the history of chemical theory of which the importance cannot be too highly estimated. This idea occurred, as by inspiration, to August Kekulé of Bonn in the year 1865, and its introduction has been marked by a quarter century of activity in research such as the science of chemistry has never experienced at any previous period of its history. The theory of the atomic structure of the benzene molecule has been extended and applied to all analogous compounds, and it is in coal-tar that we have the most prolific source of the compounds of this class. It was scarcely to be wondered at that an idea which has been so prolific as a stimulator of original investigation should have exerted a marked influence on the manufacture of tar-products. All the brilliant syntheses of colouring-matters effected of late years are living witnesses of the fertility of Kekulé's conception. In the spring of 1890 there was held in Berlin a jubilee meeting commemorating the twenty-fifth anniversary of the benzene theory. At that meeting the representative of the German coal-tar colour industry publicly declared that the prosperity of Germany in this branch of manufacture was primarily due to this theoretical notion. But if the development of the industry has been thus advanced by the theory, it is no less true that the latter has been helped forward by the industry. The verification of a chemical theory necessitates investigations for which supplies of the requisite materials must be forthcoming. Inasmuch as the very materials wanted were separated from coal-tar and purified on a large scale for manufacturing purposes, the science was not long kept waiting. The laborious series of operations which the chemist working on a laboratory scale had to go through in order to obtain raw materials, could be dispensed with when products which were at one time regarded as rare curiosities became available by the hundredweight. It is perhaps not too much to say that the advancement of chemical theory in the direction started by Kekulé has been accelerated by a century owing to the circumstance that coal-tar products have become the property of the technologist. In other words, we might have had to wait till 1965 to reach our present state of knowledge concerning the theory of benzenoid compounds if the coal-tar industry had not been in existence. And this is not the only way in which the industry has helped the science, for in the course of manufacture many new compounds and many new chemical transformations have been incidentally discovered, which have thrown great light on chemical theory. From the higher standpoint of pure science, the industry has therefore deservedly won a most exalted position. With respect to the value of the coal-tar dyes as tinctorial agents, there is a certain amount of misconception which it is desirable to remove. There is a widely-spread idea that these colours are fugitive--that they rub off, that they fade on exposure to light, that they wash out, and, in short, that they are in every way inferior to the old wood or vegetable dyes. These charges are unfounded. One of the best refutations is, that two of the oldest and fastest of natural colouring-matters, viz. alizarin and indigo, are coal-tar products. There are some coal-tar dyes which are not fast to light, and there are many vegetable dyes which are equally fugitive. If there are natural colouring-matters which are fast and which are æsthetically orthodox, these are rivalled by tar-products which fulfil the same conditions. Such dyes as aniline black, alizarin blue, anthracene brown, tartrazine, some of the azo-reds and naphthol green resist the influence of light as well as, if not better than, any natural colouring-matter. The artificial yellow dyes are as a whole faster than the natural yellows. There are at the present time some three hundred coal-tar colouring-matters made, and about one-tenth of that number of natural dyes are in use. Of the latter only ten--let us say 33 per cent.--are really fast. Of the artificial dyes, thirty are extremely fast, and thirty fast enough for all practical requirements, so that the fast natural colours have been largely outnumbered by the artificial ones. If Nature has been beaten, however, this has been rendered possible only by taking advantage of Nature's own resources--by studying the chemical properties of atoms, and giving scope to the play of the internal forces which they inherently possess-- "Yet Nature is made better by no mean, But Nature makes that mean: so, o'er that art, Which, you say, adds to Nature, is an art That Nature makes." The story told in this chapter is chronologically summarized below-- 1820. Naphthalene discovered in coal-tar by Garden. 1832. Anthracene discovered in coal-tar by Dumas and Laurent. 1834. Phenol discovered in coal-tar by Runge. 1842. Picric acid prepared from phenol by Laurent; manufactured in Manchester in 1862. 1845. Benzidine discovered by Zinin. 1859. Corallin and aurin discovered by Kolbe and Schmitt and by Persoz; leading to manufacture from oxalic acid and phenol. 1860. Synthesis of salicylic acid by Kolbe. 1864. Manchester yellow discovered by Martius, leading to manufacture of alpha-naphthylamine and then to alpha-naphthol. 1867. Magdala red discovered by Schiendl. 1868. Synthesis of alizarin by Graebe and Liebermann, leading to the utilization of anthracene, caustic soda, potassium chlorate and bichromate, and calling into existence the manufacture of fuming sulphuric acid. 1870. Galleïn, the first of the phthaleïns, discovered by A. v. Baeyer, followed in 1871 by coeruleïn, and in 1874 by the eosin dyes (Caro). These discoveries necessitated the manufacture of phthalic acid and resorcinol. 1873. Orthochromatic photography discovered by Vogel. 1876. Azo-dyes from the naphthols introduced by Roussin and Poirrier and Witt, leading to the manufacture of the naphthols, sulphanilic acid, &c. 1877. Preparation of quinone from aniline by Nietzki, utilized in photography in 1880 for manufacture of hydroquinone. 1878. Disulpho-acids of beta-naphthol introduced by Meister, Lucius, and Brüning, leading to azo-dyes from aniline, toluidine, xylidine, and cumidine. 1879. Acid naphthol yellow introduced by Caro. " Biebrich scarlet, the first secondary azo-colour, introduced by Nietzki. " Nitroso-sulpho acid of beta-naphthol discovered by the writer; followed in 1883 by naphthol green (O. Hoffmann), and in 1889 by eikonogen (Andresen). " Beta-naphthol violet, the first of the oxazines, discovered by the writer; followed in 1881 by gallocyanin. " Coal-tar saccharin discovered by Fahlberg; manufacture made practicable in 1884. 1880. Synthesis of indigo by A. v. Baeyer. " Quinoline synthesised by Skraup's process. 1881. Kairine introduced by O. Fischer, the first artificial febrifuge. " Indophenol discovered by Köchlin and Witt. " Azo-dyes from new sulpho-acid of beta-naphthol introduced by Bayer & Co. 1883. Antipyrine introduced by L. Knorr, leading to manufacture of phenylhydrazine. 1884. Congo red, the first secondary azo-colour from benzidine, introduced by Böttiger. Beginning of manufacture of cotton azo-dyes, and leading to the production of benzidine and tolidine on a large scale. 1885. Secondary azo-dyes from benzidine and tolidine containing two dissimilar amines, phenols, &c., introduced by Pfaff. " Tartrazine discovered by Ziegler; manufacture of sulpho-acid of phenylhydrazine and of dioxytartaric acid. 1885. Thiorubin introduced by Dahl & Co., leading to manufacture of thiotoluidine; followed by primuline, discovered by A. G. Green in 1887. 1886. Secondary azo-dyes of stilbene series introduced by Leonhardt & Co. ADDENDUM. By passing steam over red-hot carbon, a mixture of carbon monoxide and hydrogen is formed. This mixture of inflammable gases is known as "water-gas," and in the preparation of the gas on a large scale, coke is used as a source of carbon. If, therefore, water-gas became generally used, another use for coke would be added to those already referred to (p. 47). With reference to the consumption of coal in London (p. 46), it appears from the Report of a Committee of the Corporation of London, issued at the end of 1890, that the present rate of consumption in the Metropolis is 9,709,000 tons per annum. This corresponds to 26,600 tons per diem. It has been proved by experiment, that when coal is burnt in an open grate, from one to three per cent. of the coal escapes in the form of unburnt solid particles, or "soot," and about 10 per cent. is lost in the form of volatile compounds of carbon. It has been estimated that the total amount of coal annually wasted by imperfect combustion in this country is 45,000,000 tons, corresponding to about £12,000,000, taking the value of coal at the pit's mouth. Taking the unconsumed solid particles at the very lowest estimate of 1 per cent., it will be seen that, in London alone, we are sending forth carbonaceous and tarry matter into the atmosphere at the rate of about 266 tons daily; and volatile carbon compounds at the daily rate of 2660 tons (see p. 32). At the price of coal in London this means that, in solid combustibles alone, we are absolutely squandering about £10,000 annually, to say nothing of the damage caused by the presence of this sooty pall. Such facts as these require no comment; they speak for themselves in sombre gloom, and in the sickliness of our town vegetation--they give a new meaning to the term "in darkest London," and they plead eloquently for science and legislation to show us "the way out." INDEX. Accum, condensation of tar-oils, 69 Acetic acid, 64 Acetophenone, 178 Acid brown, 151 Acid greens, 106 Acid magenta, 92 Acid naphthol yellow, 143 Acid yellow, 120 Acridine, 180 Air, composition of, 24 Albo-carbon light, 140 Alizarin black, 172 Alizarin blue, 174 Alizarin carmine, 174 Alizarin green, 174 Alizarin orange, 174 Alkali blue, 93 Amidodimethylaniline, 112 Ammonia in gas-liquor, 64 Ammonia, origin in gas-liquor, 65 Analyses of coal, 23 Aniline black, 114 Aniline, history, 75 Aniline, manufacture, 87 Aniline yellow, 116 Annual production of ammonia, 68 Anthracene, 171 Anthracene brown, 174 Anthracene oil, 81, 167 Anthragallol, 174 Anthrapurpurin, 174 Anthraquinone, 173 Antifebrine, 179 Antipyrine, 183 Archil substitute, 151 Arctic coal, 12 Arsenic acid process, 90 Arsenic acid, recovery, 94 Artificial alizarin, 173 Artificial purpurin, 173 Asphalte, 176 Auramine, 106 Aurin, 132 Azines, 109 Azo-blacks, 159 Azo-colours, 118 Azo-dyes for cotton, 158 Azobenzene, 119 Azo-dyes from salicylic acid, 135 Azotoluene, 119 Baeyer, A. v., indigo, 127 Baeyer, A. v., phthaleïns, 146 Basle blue, 111 Becher, early experiments, 34 Beet-sugar cultivation, 67 Benzal chloride, 102 Benzaldehyde, 103 Benzene, discovery, 73 Benzene, final purification, 86 Benzene in tar-oil, 73 Benzene theory, 196 Benzidam, 75 Benzidine, 136 Benzoic acid, manufacture, 104 Benzotrichloride, 102 Benzyl chloride, 102 Bernthsen, methylene blue, 113 Bethell, timber preserving, 70 Biebrich scarlet, 156 Biology, dyes used in, 192 Bismarck brown, 116 Bitter-almond oil, 103 Bone oil, 180 Böttiger, Congo-red, 157 Bréant, timber pickling, 70 Briquettes, 178 Burning naphtha, 86 Calorific value of carbon, 25 Calorific value of coal, 20 Carbolic acid, 129 Carbolic oil, 23, 80, 129 Carbon dioxide, 24 Carboniferous period, 11 Caro and Kern, phosgene dyes, 106 Caro and Wanklyn, rosolic acid, 133 Caro, fluoresceïn and eosin, 147 Caro, methylene blue, 112 Chemical washing, 83 Chlorophyll, 29 Chrysamines, 136 Chrysoïdine, 116 Cinnamic acid, 128 Clayton, Dean, distils coal, 35 Clegg, Samuel, gas-engineer, 40 Coal, amount raised, 59 Coal-fields of United Kingdom, 60 Coal-gas, composition, 56 Coal-gas, manufacture, 42 Coal-mining, history, 57 Coal, origin, 9 Coal, supply, 59 Coeruleïn, 147 Coke, composition of, 48 Coke from gas-retorts, 45 Coke-oven tar, 49 Coke, uses of, 47 Combustion, 23 Composition of coal, 23 Congo red, 157 Conservation of energy, 18 Constitution of molecules, 95 Corallin, 132 Cotton dyes, 137 Coumarin, 185 Coupier's process, 91 Creosote oil, 163 Creosoting of timber, 70 Cresols, 131 Cresylic acid, 131 Cretaceous coal, 12 Crocein scarlets, 156 Crystal violet, 106 Cumidine, 155 Cyanin, 188 Dale and Caro, induline, 120 Destructive distillation, 33 Diazo-compounds, 116 Diazotype, 191 Dimethylaniline, 100 Dinitrobenzene, 120 Diphenylamine, 101 Diphenylamine blue, 101 Distillation, fractional, 78 Doebner, malachite green, 102 Dover, coal under, 60 Dumas and Laurent, anthracene, 171 Dundonald, Earl, early experiments, 39 Eikonogen, 189 Electricity as an illuminating agent, 62 Eocene coal, 12 Eosin, 147 Erythrosin, 188 Essence of mirbane, 74 Exalgine, 179 Fahlberg, saccharin, 186 Faraday, discovers benzene, 73 Fast red, 151 Fertilization by ammonia, 66 Fire-damp, 32 First runnings, 80 Fischer, E. and O., rosaniline, 97 Fischer, hydrazines, 183 Fischer, malachite green, 103 Flavaniline, 180 Flavopurpurin, 174 Fluoresceïn, 147 Foot-pound, 19 Fractional distillation, 78 Fritzsche, aniline, 75 Galleïn, 146 Gallic acid, 146 Gallocyanin, 162 Gambines, 161 Garancin, 168 Garden, naphthalene, 139 Gas producers, 57 Gas, quantity obtained from coal, 45 Girard and De Laire, rosaniline blues, 92 Glucosides, 169 Goethe, visit to coke-burner, 48 Græbe and Liebermann, alizarin, 170 Graphite, 12 Grässler, acid yellow, 120 Green, A. G., primuline, 160 Griess, diazo-compounds, 116 Hales, Rev. Stephen, distils coal, 37 Hofmann, benzene in tar-oil, 73 Hofmann, red from aniline, 89 Hofmann's violets, 93 Homologous series, 152 Horse-power, 22 Hull, Prof., coal supply, 59 Hydrazines, 183 Hydrocarbons of benzene series, 82 Hydrogen, calorific value, 25 Hydroquinone, 189 Hypnone, 179 Indigo plants, 124 Indigo, syntheses, 126 Indophenol, 162 Indulines, 121 Ingrain colours, 160 Iodine green, 94 Iron smelting, 16 Iron swarf, 87 Isochromatic plates, 188 Isomerism, 88 Joule, mechanical equivalent of heat, 19 Juglone, 186 Jurassic coal, 12 Kairine, 182 Kekulé, benzene theory, 196 Kekulé and Hidegh, azo-dyes, 135 Koch, tubercle, 193 Köchlin, gallocyanin, 162 Köchlin and Witt, indophenol, 162 Kolbe, salicylic acid, 134 Kolbe and Schmitt, phenol dye, 132 Kyanol, 75 Lampblack, 139, 166 Laurent, phenol, 131 Laurent, phthalic acid, 143 Laurent, picric acid, 136 Lauth, methyl violet, 98 Lauth's violet, 111 Leonhardt & Co., stilbene dyes, 137 Lightfoot, aniline black, 114 Light oil, 80 Light oils, early uses, 71 Lister, antiseptic surgery, 131 London, coal introduced, 58 London, illuminated by gas, 40 Lucigen burner, 163 Madder, 168 Magdala red, 149 Magenta, history, 89 Malachite green, 102 Manchester brown, 116 Manchester yellow, 142 Mansfield, isolation of benzene, 73 Mansfield's still, 77 Manures, 66 Marsh gas, 32 Mauve, discovery, 74 Mechanical value of coal, 22 Medlock, magenta process, 90 Methyl chloride, 99 Methylene green, 113 Methyl green, 101 Methyl violet, 98 Mirbane, essence, 74 Murdoch, introduces coal-gas, 40 Naphthalene, annual production, 141 Naphthalene in carbolic oil, 130 Naphthionic acid, 151 Naphthol green, 161 Naphthol orange, 151 Naphthols, 141 Naphthylamines, 142 Natanson, aniline red, 89 Neutral red, 111 Neutral violet, 111 New blue, 161 Nicholson blue, 93 Nicholson, magenta process, 90 Nietzki, azines, 109 Nietzki, Biebrich scarlet, 156 Nietzki, quinone, 191 Night blue, 106 Nigrosine, 121 Nitrification, 66 Nitrobenzene process, 91 Nitrosodimethylaniline, 111 Non-Carboniferous coal, 11 Number of compounds in tar, 81 Old Red Sandstone, coal in, 12 Oligocene brown coal, 12 Orthochromatic plates, 188 Oxazines, 162 Oxide of iron for gas purifying, 44 Paraffin oil and wax, 50 Patent fuel, 178 Perfumes, 185 Perkin, alizarin, 170 Perkin, discovers mauve, 74 Permanence of dyes, 198 Permian coal, 12 Persoz, phenol dye, 132 Pharmaceutical preparations, 178 Phenanthrene, 172 Phenols, 129 Phosgene dyes, 106 Phosphine, 94, 180 Photographic developers, 189 Phthaleïns, 146 Phthalic acid, 143 Picric acid, 136 Pitch, 81, 176 Plants, growth of, 26 Ponceaux, 151 Primary azo-dyes, 156 Primuline, 160 Propiolic acid, 128 Purpurin, 169 Pyrazole, 183 Pyridine, 87 Pyridine bases, 179 Pyrogallol, 146 Quinaldine, 182 Quinic acid, 189 Quinoline, 180 Quinoline green, 182 Quinoline red, 188 Quinoline yellow, 182 Quinones, 172 Read Holliday's lamp, 72 Rectification of hydrocarbons, 84 Resorcinol, 145 Rhodamines, 148 Roccellin, 151 Roman coal-mining, 57 Rosaniline blues, 92 Rosaniline from rosolic acid, 133 Rosolic acid, 132 Runge, kyanol, 75 Runge, phenol in tar, 131 Saccharin, 186 Saffranine, 108 Salicylic acid, 134 Salicylic aldehyde, 185 Salols, 179 Schiendl, Magdala red, 149 Scotland, shale-oil industry, 53 Sea coal, 58 Secondary azo-dyes, 156 Shale, nature of, 51 Shale-oil industry, 50 Skraup, quinoline, 181 Sodium nitrite, 119 Solar energy, 28 Soluble blue, 93 Solvent naphtha, 86 Steam-engines, 20 Stilbene azo-dyes, 137 Structure of coal, 15 Sulphanilic acid, 150 Sulphuric acid, 45 Sunlight, source of energy in coal, 30 Surgery, antiseptic, 131 Tar distilling, 77 Tar, first utilization, 69 Tar from coke-ovens, 49 Tar, quantity obtained from coal, 45 Tartrazine, 184 Tertiary coal, 12 Thalline, 182 Thermifugine, 182 Thiazines, 113 Thiodiphenylamine, 113 Thiorubin, 160 Timber pickling, 70 Tolidine, 136 Toluene from tar, 81 Torbane Hill coal, 52 Transformation of wood into coal, 31 Triassic coal, 12 Trimethylamine, 99 Trinitrophenol, 136 Triphenylmethane, 97 Tubercle bacillus, 193 Turkey red, 170 Underclay, 13 Unverdorben, crystallin, 75 Uses of coal, 16 Vanillin, 185 Vegetable deposits, recent, 13 Verguin, red from aniline, 90 Victoria blue, 106 Victoria yellow, 137 Vinasse, 99 Vincent, methyl chloride, 100 Violaniline, 121 Wasteful use of coal, 32, 203 Water, composition of, 25 Water gas, 203 Watson, Bishop, coke-oven tar, 50 Watson, Bishop, distils coal, 37 Wealden iron industry, 17 Whitaker, W., coal in S.-E. England, 60 Winsor, promotes introduction of gas, 41 Witt, azines, 109 Witt, chrysoïdine, 116 Witt, naphthol orange, 150 Wood vinegar, 64 Woody fibre, 26 Woulfe, picric acid, 136 Xylenes from tar, 81 Xylidine scarlet, 153 Young, James, burning-oil, 51 Ziegler, tartrazine, 184 Zinin, benzidam, 75 THE END. _Richard Clay & Sons, Limited, London & Bungay._ Footnotes: [1] "An experiment concerning the Spirit of Coals," _Phil. Trans._ (abridged), vol. viii. p. 295. [2] _Report of the Coal Commissioners_ (1866-71), vol. i. [3] In a paper read before the Royal Statistical Society by Mr. Price-Williams in 1889, this author points out that, owing to the introduction of the Bessemer process and other economical improvements, the amount of coal used in the iron and steel manufacture had fallen in 1867 to about sixteen and a half per cent. of the total quantity raised. [4] This remark does not apply to Great Britain; our Excise regulations have practically killed those branches of manufacture requiring the use of pure wood-spirit. [5] Since the above was written, new synthetical processes for the production of indigo have been made known in Germany by Karl Heumann. Of the commercial aspect of these discoveries it is of course impossible at present to form an opinion. [6] With phthalic anhydride gives fluoresceïn and dyes of eosin and rhodamin series. [7] Diazotised and combined with naphthylamines, naphthols, or their sulpho-acids give azo-dyes. [8] With naphthols give oxazines and indophenol. [9] Diazotised and combined with phenols, amines, or sulpho-acids to form azo-dyes. [10] Combined with diazotised amido-compounds to form azo-dyes. 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44276	----	THE TOILET OF FLORA. Illustration: _FRONTISPIECE. The Graces._ THE TOILET OF FLORA; OR, A COLLECTION OF THE MOST SIMPLE AND APPROVED METHODS OF PREPARING BATHS, PERFUMES, ESSENCES, AND POMATUMS, SWEET-SCENTED POWDERS, WATERS. WITH RECEIPTS for COSMETICS of every Kind, that can smooth and brighten the SKIN, give Force to BEAUTY, and take off the Appearance of OLD AGE and DECAY. By Pierre-Joseph Buc'hoz _FOR THE USE OF THE LADIES._ A NEW EDITION, IMPROVED. LONDON, Printed for J. MURRAY, No. 32, Fleet-street; and W. NICOLL, St. Paul's Church Yard. M DCC LXXIX. ADVERTISEMENT. The chief Intention of this Performance is to point out, and explain to the Fair Sex, the Methods by which they may preserve and add to their Charms; and by which many natural Blemishes and Imperfections may be remedied or concealed. The same Share of Grace and Attractions is not possessed by all of them; but while the Improvement of their Persons is the indispensable Duty of those who have been little favoured by Nature, it should not be neglected even by the few who have received the largest Proportion of her Gifts. The same Art which will communicate to the former the Power of pleasing, will enable the latter to extend the Empire of their Beauty. It is possible to remove, or, at least, to cover the Defects of the one Class, and to give Force and Lustre to the Perfections of the other. The Author, however, though in general he has framed his Work for the Advantage of the Ladies, has not entirely confined it to them. The Virtues of Plants and Vegetables, beside the Service they furnish for the Toilet, have their Use in Articles of Luxury. He has thence been induced to address himself also to the Perfumer: and his Publication, he flatters himself, while it comprizes a very perfect Collection of the Methods which tend to improve Beauty, to repair the Wastes of Fatigue, and to avert the Marks of Age or Decline, includes likewise a full Account of whatever relates to domestic Oeconomy and Expence. Uncommon Pains have been taken to improve the present Edition, which contains a System of the Cosmetic Art, infinitely superior to any that has hitherto appeared; and it has likewise uniformly rendered the various Prescriptions not only compatible with, but subservient to, the Preservation, and even the Improvement of Health; an Object of the greatest Importance in a Work of this Kind. CONTENTS. No. Page. 1. An Aromatic Bath 1 2. A Cosmetic Bath 2 3. An Emollient Bath for the Feet ib. 4. An Aromatic Bath for the Feet 3 5. An excellent Preservative Balsam against the Plague ib. 6. An excellent Cosmetic for the Face 5 7. A curious Perfume ib. 8. Perfumed Chaplets and Medals 6 9. Receipt to thicken the Hair, and make it grow again on a bald part ib. 10. An approved Depilatory Fluid 7 11. A Powder to prevent Baldness 8 12. To quicken the Growth of Hair ib. 13. A compound Oil for the same Intention ib. 14. A Fluid to make the Hair grow 9 15. A Liniment of the same Kind ib. 16. To change the Colour of the Hair 10 17. Simple Means of producing the same Effect ib. 18. To change the Hair or Beard black 11 19. A Fluid to dye the Hair of a flaxen Colour 12 20. A perfumed Basket 13 21. Natural Cosmetics ib. 22. A remedy for Corns on the Feet 14 23. A Coral Stick for the Teeth 14 24. A Receipt to clean the Teeth, and make the Flesh grow close to the Root of the Enamel 15 25, 26, 27. Receipts to strengthen the Gums and fasten loose Teeth 15, 16 28. For rotten Teeth 17 29. A Liquid Remedy for decayed Teeth ib. 30. A Powder to clean the Teeth 18 31. A Remedy for sore Gums and loose Teeth ib. 32. An approved Receipt against that troublesome Complaint, called the Teeth set on Edge ib. 33. A Liquid for cleansing the Teeth 19 34. A sure Preservative from the Tooth Ache, and Defluxions on the Gums or Teeth ib. 35, 36, 37, 38, 39. Methods to make the Teeth beautifully white 20-22 40. A Powder to cleanse the Teeth 22 41. Mr. Rae's Receipt for making a Powder for the like Purpose 23 42. Another ib. 43. An efficacious Tooth-Powder 24 44. A Powder to cleanse the Teeth ib. 45. A Tincture to strengthen the Gums, and prevent the Scurvy 25 46. Mr. Baumé's Manner of preparing the Roots for cleaning the Teeth ib. 47. Manner of preparing Sponges for the Teeth 28 48. Rule for the Preservation of the Teeth and Gums 29 49. For stopping the Decay of Teeth 31 WATERS. 50. The Celestial Water 32 51, 52. Receipts to make the genuine Hungary-Water 35, 36 53, 54. Directions for making Lavender-Water 37, 38 55, 56. ----Rose-Water 39-41 57, 58. ----Orange-Flower Water 42, 43 59. Magisterial Balm-Water 46 60. Compound Balm-Water, commonly called Eau de Carmes 49 61. Sweet Honey-Water 50 62. Sweet-scented Water 52 63. German sweet-scented Water 53 64. Imperial Water 56 65, 66. Odoriferous Water 57 67. The Ladies Water 58 68. A beautifying Wash 59 69. A Cosmetic Water ib. 70. An excellent Cosmetic ib. 71. Venice Water highly esteemed 60 72. A Balsamic Water ib. 73. Angelic Water, of a most agreeable scent 61 74. Nosegay or Toilet Water 62 75. Spirit of Guaiacum 63 76. The Divine Cordial ib. 77. Compound Cypress Water 65 78. Imperial Water 66 79. All Flower Water 68 80. A curious Water known by the Name of the Spring Nosegay 69 81. A Cosmetic Water, that prevents Pits after the Small-Pox 71 82. A Cooling Wash ib. 83, 84. An excellent Water to clear the Skin, and take away Pimples 72 85. Venetian Water to clear a Sun-burnt Complexion 73 86. A Water for Pimples in the Face 74 87. A Fluid to clear a tanned Skin ib. 88. A Fluid to whiten the Skin ib. 89. A Beautifying Wash 75 90. A Water that tinges the Cheeks a beautiful Carnation Hue 76 91. A Cosmetic Water 77 92. A Water, christened, the Fountain of Youth ib. 93. A Water that preserves the Complexion 78 94. A Water that gives a Gloss to the Skin 80 95. A Preservative from Tanning ib. 96, 97, 98. Certain Means of removing Freckles 81, 82 99, 100. A Water to prevent Freckles, or Blotches in the Face 82, 83 101, 102. A Water to improve the Complexion 83 103, 104. A Cosmetic Water 84, 85 105. A simple Balsamic Water, which removes Wrinkles 85 106. A Water to change the Eye-brows black 86 107. To remove Worms in the Face 86 108. The Duchess de la Vrilliere's Mouth-Water 87 109. Another Water for the Teeth, called Spirituous Vulnerary Water 88 110. Receipt to make Vulnerary Water 89 111, 112, 113, 114. Waters for the Gums 90-92 115. A simple Depilatory 92 116. Prepared Sponges for the Face ib. 117. Spirit of Roses 93 118. Inflammable Spirits of all Kinds of Flowers 97 ESSENCES. 119, 120. Method of extracting Essences from Flowers 98-101 121. Essence of Ambergrise 102 122. A Remedy for St. Anthony's Fire, or Erysipelatous Eruptions on the Face 103 FLOWERS. 123. Manner of drying Flowers, so as to preserve their natural Colours ib. 124, 125. Different Methods of preserving Flowers 106-108 126. Another Method of preserving Flowers a long while, in their natural Shape and Colour. 109 GLOVES. 127. White Gloves scented with Jasmine after the Italian Manner 110 128. Gloves scented without the Flowers 111 129. White Gloves scented with Ketmia or Musky Seed 112 130. To colour Gloves a curious French Yellow 113 131, 132. Curious Perfumes in Gloves 114 133, 134. Excellent Receipts to clear a tanned Complexion 115 BREATH. 135, 136. Receipts to sweeten the Breath 115, 116 OILS. 137, 138. Cosmetic Oils 116 139. Oil of Wheat 117 140. Compound Oil, or Essence of Fennel ib. 141. Oil of Tuberoses and Jasmine 118 142. An Oil scented with Flowers for the Hair 119 ESSENTIAL OILS, or QUINTESSENCES. 143. Essential Oil, commonly called Quintessence of Lavender 121 144. To make Essence of Cinnamon 122 145. To make Quintessence of Cloves 123 146. A Cosmetic Juice 125 VIRGIN's MILK. 147. A safe and approved Cosmetic ib. 148, 149. Others, very easily made 126, 127 150. A Liniment to destroy Vermin 127 LOTIONS. 151. A Lotion to strengthen the Gums, and sweeten the Breath 128 152. Another Lotion to fasten the Teeth, and sweeten the Breath 130 153. An admirable Lotion for the Complexion 131 154. An admirable Varnish for the Skin 132 155. A Liniment to destroy Nits 133 156. A Liniment to change the Beard and Hair black ib. 157, 158. Depilatory Liniment 134, 135 159, 160. Excellent Lip-Salves 135, 136 NAILS. 161. A Liniment to promote the Growth and Regeneration of Nails 136 162, 163. Remedies for Whitlows; a Disorder that frequently affects the Fingers 137, 138 PERFUMES. 164. Scented Tablets or Pastils 138 165. A pleasant Perfume 139 166. Common perfumed Powder 141 167. A Cassolette ib. 168. To perfume a whole House, and purify the Air ib. 169. A Perfume for scenting Powder ib. PASTILS. 170, 171. Excellent Compositions to perfume a Room 143, 144 172. Fragrant Pastils made use of by way of Fumigation 145 173. Pastils of Roses 146 PASTES. 174. Paste of dried Almonds to cleanse the Skin ib. 175. Soft Almond Paste 147 176. Paste for the Hands 148 177, 178, 179, 180, 181, 182. Pastes for the Hands 148-152 POMATUMS. 183. Cold Cream, or Pomatum for the Complexion 152 184, 185. Cucumber Pomatums 154, 155 186. Lavender Pomatum 156 187, 188, 189. Lip-Salves 158, 159 190. A Yellow Lip-Salve 160 191, 192, 193, 194, 195. Scarlet Lip-Salves 161, 164 196. White Pomatum 164 197. Red Pomatum 165 198. A Pomatum to remove Redness, or Pimples in the Face 166 199. A Pomatum for Wrinkles 167 200, 201. For the same Intention 167, 168 202. Pomatum for a red or pimpled Face 168 203. A Pomatum for the Skin 169 204. Pomatum to make the Hair grow on a Bald Part, and thicken the Hair 170 205. Another Pomatum for the Hair 171 206. Manner of scenting Pomatums for the Hair 172 207. Orange-Flower Pomatum 173 208. Sultana Pomatum 174 209, 210. Sweet smelling Perfumes 174-176 POWDERS. 211. Orange-Flower Powder 177 212. Jonquil Powder 178 213, 214. Coarse Violet Powders 179, 180 215. Jasmine Powder 181 216. Ambrette Powder ib. 217, 218. Cyprus Powders 182, 183 219. Perfumed Powder 183 220. The White Powder that enters into the Composition of the Delightful Perfume 184 221. Prepared Powder ib. 222. A Powder to nourish the Hair 185 223. Common Powder 186 224. White Powder ib. 225, 226. Grey Powders 187 227. Flaxen-coloured Powder 188 228. Bean Flour ib. 229, 230. To sweeten the Breath 188, 189 231. A Remedy for scorbutic Gums 189 232. A Remedy for moist Feet ib. FLEAS. 233, 234, 235, 236. Certain Methods of destroying Fleas 190, 19 WRINKLES. 237. A Secret to take away Wrinkles 191 CARMINES. 238, 239. Rouges for the Face 192, 193 240. The Turkish method of preparing Carmine 193 241. A Liquid Rouge that exactly imitates Nature 194 242. An Oil that possesses the same Property 195 SWEET SCENTED BAGS. 243. A sweet-scented Bag to wear in the Pocket 196 244. Bags to scent Linen ib. 245. An agreeable sweet-scented Composition 197 246. Manner of making various sorts of these little Bags or Sachels ib. WASH-BALLS. 247. White Soap 199 248. Honey Soap ib. 249. A perfumed Soap 200 250. A Fine Scented Wash-ball 201 251. A Wash-ball, an excellent Cosmetic for the Face and Hands 202 252. Bologna Wash-balls 203 253. Another excellent Wash-ball for the Complexion 204 254. Seraglio Wash-balls 205 255. An Hepatic Salt, to preserve the Complexion 206 EYE-BROWS. 256. To change the Eye-brows black 207 MARKS OF THE SKIN. 257, 258. To efface Spots or Marks of the Mother, on any Part of the Body 208 259. To take away Marks, and fill up the Cavities left after the Small-Pox 209 COMPLEXION. 260. Certain Methods to improve the Complexion 210 261. The Montpellier Toilet ib. 262. Sweet-scented Troches to correct a bad Breath 212 263. A curious Varnish for the Face 213 WARTS. 264, 265, 266, 267, 268. Medicines to Cure Warts 215 VINEGARS. 269. Distilled Vinegar 216 270. Distilled Lavender Vinegar 217 271. Vinegar of the Four Thieves 219 EYES. 272, 273, 274. For Watery Eyes 220, 221 275. An excellent Ophthalmic Lotion 221 276. An Ophthalmic Poultice 222 277. A Poultice for inflamed Eyes ib. 278. Sir Hans Sloane's Eye Salve 223 279. An Ophthalmic Fomentation ib. 280. A simple Remedy to strengthen the Sight 224 SUPPLEMENT. USEFUL RECEIPTS. 281. To take Iron Mould out of Linen 225 282. Stains of Oil ib. 283. Scowering Balls 226 284. Stains of Coomb ib. 285. Stains of Urine 227 286. Stains on Cloth of whatever Colour ib. 287. Spots of Ink ib. 288. Spots of Pitch and Turpentine 228 289. Spots of Oil on Satin and other Stuffs, and on Paper ib. 290. Spots on Silk 229 291. Balls to take out Stains ib. 292. To clean Gold and Silver Lace 229 293. To restore its original Lustre to Tapestry ib. 294. To clean Turkey Carpets 230 295. To refresh Tapestry Carpets, Hangings, or Chairs ib. 296. To take Wax out of Silk or Camblet 231 297. To take Wax out of Velvet of all Colours except Crimson 232 298. To wash Gold or Silver Work on Linen, or any other Stuff, so as to look like new ib. 299. To take Spots out of Silk or Woollen Stuff 233 300. To take Stains of Oil out of Cloth ib. 301. To take Stains out of White Cloth 234 302. To take Stains out of Crimson Velvet, and other coloured Velvets ib. 303. A Soap that takes out all Manner of Spots and Stains 235 304. Another Method to take Spots or Stains out of White Silk or Crimson Velvet 236 305. A Receipt to clean Gloves without wetting ib. 306. To colour Gloves 237 307. To wash Point Lace 238 308. To clean Point Lace without washing ib. 309. To wash black and white Sarcenet ib. 310. A Soap to take out all Kinds of Stains 239 311. An expeditious Method to take Stains out of Scarlet, or Velvet of any other Colour 240 DIFFERENT WAYS OF PREPARING SNUFF. 312. Method of making Snuff 240 313. Method of cleansing Snuff in order to scent it 241 314, 315. Methods of scenting Snuff 243, 244 316, 317. Perfumed Snuff 245, 246 318. Snuff after the Maltese Fashion 246 319. The Genuine Maltese Snuff ib. 320. Italian Snuff 247 321. Snuff scented after the Spanish Manner ib. 322. Method of colouring Snuff Red or Yellow 249 323, 324, 325, 326. Herb Snuffs 250, 251 THE TOILET OF FLORA. 1. _An Aromatic Bath._ Boil, for the space of two or three minutes, in a sufficient quantity of river-water, one or more of the following plants; viz. Laurel, Thyme, Rosemary, Wild Thyme, Sweet-Marjoram, Bastard-Marjoram, Lavender, Southernwood, Wormwood, Sage, Pennyroyal, Sweet-Basil Balm, Wild Mint, Hyssop, Clove-july-flowers, Anise, Fennel, or any other herbs that have an agreeable scent. Having strained off the liquor from the herbs, add to it a little Brandy, or camphorated Spirits of Wine. This is an excellent bath to strengthen the limbs; it removes pains proceeding from cold, and promotes perspiration. 2. _A Cosmetic Bath._ Take two pounds of Barley or Bean-meal, eight pounds of Bran, and a few handfuls of Borrage Leaves. Boil these ingredients in a sufficient quantity of spring water. Nothing cleanses and softens the skin like this bath. 3. _An Emollient Bath for the Feet._ Boil, in water, a pound of Bran, with a few Marsh-mallow Roots, and two or three handfuls of Mallow Leaves. 4. _An Aromatic Bath for the Feet._ Take four handfuls of Pennyroyal, Sage, and Rosemary, three handfuls of Angelica, and four ounces of Juniper Berries; boil these ingredients in a sufficient quantity of water, and strain off the liquor for use. 5. _An excellent Preservative Balsam against the Plague._ Scrape fine twelve Scorzonera and Goatsbread Roots; simmer them over a gentle fire in three quarts of Lisbon or French White Wine, in a vessel closely covered, to prevent the too great evaporation of the vinous spirit. When the roots are sufficiently boiled, strain off the liquor through a linen strainer with a gentle pressure: then add to it the Juice of twelve Lemons, with Cloves, Ginger, Cardamom Seeds, and Aloes Wood, grossly powdered, of each half an ounce; and about one ounce of each of the following herbs, viz. fresh Leaves of Rue, Elder, Bramble, and Sage; boil all together over a gentle fire, till one quart is wasted away; strain the liquor off immediately through a strong linen bag, and keep it in an earthen or glass vessel close stopped. Drink every morning fasting, for nine days together, half a pint of this Balsam, by which means you will be able to resist the malignancy of the Atmosphere, though you even visit infected persons. The same end may be promoted by washing the mouth and nostrils with Vinegar; and by holding to the nose a bit of Camphire, slightly wrapped in muslin; or by frequently chewing a piece of Gum Myrrh. 6. _An excellent Cosmetic for the Face._ Take a pound of levigated Hartshorn, two pounds of Rice Powder, half a pound of Ceruss, Powder of dried Bones, Frankincense, Gum Mastic, and Gum Arabic, of each two ounces. Dissolve the whole in a sufficient quantity of Rose-water, and wash the face with this fluid. 7. _A curious Perfume._ Boil, in two quarts of Rose-water, an ounce of Storax, and two ounces of Gum Benjamin; to which add, tied up in a piece of gauze or thin muslin, six Cloves bruised, half a drachm of Labdanum, as much Calamus Aromaticus, and a little Lemon-peel. Cover the vessel up close, and keep the ingredients boiling a great while: strain off the liquor without strong pressure, and let it stand till it deposit the sediment, which keep for use in a box. 8. _Perfumed Chaplets and Medals._ Take Marechal Powder, and make it into a paste with Mucilage of Gum Tragacanth and Arabic, prepared with All-flower-water (the receipt for which is contained in this book.) The mould into which it is put must be rubbed with a little Essence of Jassmine, or of any other sweet-scented herb, to prevent the Paste from sticking. This Paste in colour resembles Coffee. 9. _Receipt to thicken the Hair, and make it grow on a bald part._ Take Roots of a Maiden Vine, Roots of Hemp, and Cores of soft Cabbages, of each two handfuls; dry and burn them; afterwards make a lye with the ashes. The head is to be washed with this lye three days successively, the part having been previously well rubbed with Honey. 10. _An approved Depilatory, or a Fluid for taking off the Hair._ Take Polypody of the Oak, cut into very small pieces; put them into a glass vessel, and pour on them as much Lisbon, or French White Wine, as will rise about an inch above the ingredients: digest in balneo Mariæ (or a bath of hot water) for twenty-four hours; then distil off the liquor by the heat of boiling water, till the whole has come over the helm. A linen cloth wetted with this fluid, may be applied to the part on which the hair grows, and kept on it all night; repeating the application periodically till the hair falls off. The distilled water of the Leaves and Roots of Celandine, applied in the same manner, has the like effect. 11. _A Powder to prevent Baldness._ Powder your head with powdered Parsley Seed, at night, once in three or four months, and the hair will never fall off. 12. _To quicken the Growth of Hair._ Dip the teeth of your comb every morning in the expressed Juice of Nettles, and comb the hair the wrong way. This expedient will surprisingly quicken the growth of the hair. Some, after having shaved the head, foment it with a decoction of Wormwood, Southernwood, Sage, Betony, Vervain, Marjoram, Myrtle, Roses, Dill, Rosemary, or Misletoe. 13. _A compound Oil for the same Intention._ Take half a pound of green Southernwood bruised, boil it in a pint and a half of Sweet Oil, and half a pint of Red Wine; when sufficiently boiled, remove it from the fire, and strain off the liquor through a linen bag: repeat this operation three times with fresh Southernwood. The last time add to the strained liquor two ounces of Bears-grease. This oil quickly makes the hair shoot out. 14. _A Fluid to make the Hair grow._ Take the tops of Hemp as soon as the plant begins to appear above ground, and infuse them four and twenty hours in water. Dip the teeth of the comb in this fluid, and it will certainly quicken the growth of the hair. 15. _A Liniment of the same Kind._ Take six drachms of Labdanum, two ounces of Bears-grease, half an ounce of Honey, three drachms of powdered Southernwood, a drachm and a half of Ashes of Calamus Aromaticus Roots, three drachms of Balsam of Peru, and a little Oil of Sweet Almonds. Mix into a liniment. 16. _To change the Colour of the Hair._ First wash your head with spring-water, then dip your comb in Oil of Tartar, and comb yourself in the Sun: repeat this operation three times a day, and at the end of eight days at most the hair will turn black. If you are desirous of giving the hair a fine scent, moisten it with Oil of Benjamin. 17. _Simple Means of producing the same Effect._ The Leaves of the Wild Vine change the hairs black, and prevent their falling off. Burnt Cork; Roots of the Holm-oak, and Caper-tree; Barks of Willow, Walnut-tree and Pomegranate; Leaves of Artichoaks, the Mulberry-tree, Fig-tree, Rasberry-bush Shells of Beans; Gall and Cypress-nuts; Leaves of Myrtle; green Shells of Walnuts; Ivy-berries, Cockle, and red Beet-seeds, Poppy-flowers, Alum, and most preparations of Lead. These ingredients may be boiled in Rain-water, Wine or Vinegar, with the addition of some cephalic Plant, as Sage, Marjoram, Balm, Betony, Clove-july-flowers, Laurel, &c. &c. 18. _To change the Hair or Beard black._ Take Oil of Costus and Myrtle, of each an ounce and a half; mix them well in a leaden mortar; adding liquid Pitch, expressed Juice of Walnut Leaves and Laudanum, of each half an ounce; Gall-nuts, Black-lead, and Frankincense, of each a drachm; and a sufficient quantity of Mucilage of Gum Arabic made with a decoction of Gall Nuts. Rub the head and chin with this mixture, after they have been shaved. 19. _A Fluid to die the Hair of a flaxen Colour._ Take a quart of Lye prepared from the Ashes of Vine Twigs; Briony, Celandine Roots, and Turmeric, of each half an ounce; Saffron and Lily Roots, of each two drachms; Flowers of Mullein, Yellow Stechas, Broom, and St. John's-wort, of each a drachm; boil these ingredients together, and strain off the Liquor clear. Frequently wash the hair with this fluid, and in a little time it will change to a beautiful flaxen colour. 20. _A perfumed Basket._ Place a layer of perfumed Cotton extremely thin and even on a piece of Taffety stretched in a frame; strew on it some Violet Powder, and then some Cypress Powder; cover the whole with another piece of Taffety: nothing more remains to complete the work, but to quilt it, and cut it of the size of the basket, trimming the edges with ribband. 21. _Natural Cosmetics._ The Juice that issues from the Birch-Tree, when wounded with an auger in spring, is detersive and excellent to clear the complexion: the same virtue is attributed to its distilled water. Some people recommend Strawberry-water; others the decoction of Orpiment, and some Frog-spawn-water. 22. _A remedy for Corns on the Feet._ Roast a Clove of Garlic, or an Onion, on a live coal or in hot ashes; apply it to the corn, and fasten it on with a piece of cloth. This softens the corn to such a degree, as to loosen and wholly remove it in two or three days. Foment the corn every other night in warm water, after which renew the application. The same intention will be yet more effectually answered by applying to the corn a bit of the plaster of Diachylon with the Gums, spread on a small piece of linen; removing it occasionally to foment the corn with warm water, and pare off the softened part with a penknife. 23. _A Coral Stick for the Teeth._ Make a stiff Paste with Tooth Powder and a sufficient quantity of Mucilage of Gum Tragacanth: form with this Paste little cylindrical Rollers, the thickness of a large goose quill, and about three inches in length. Dry them in the shade. The method of using this stick is to rub it against the teeth, which become cleaner in proportion as it wastes. 24. _A receipt to clean the Teeth and Gums, and make the Flesh grow close to the Root of the Enamel._ Take an ounce of Myrrh in fine powder, two spoonfuls of the best white Honey, and a little green Sage in fine powder; mix them well together, and rub the teeth and gums with a little of this Balsam every night and morning. 25. _Ditto, to strengthen the Gums and fasten loose Teeth._ Dissolve an ounce of Myrrh as much as possible in half a pint of Red Wine and the same quantity of Oil of Almonds: Wash the mouth with this fluid every morning. This is also an excellent remedy against worms in the teeth. 26. _Another._ Dissolve a drachm of Cachoe (an Indian perfume) in a quart of Red Wine, and use it for washing the mouth. 27. _Or rather._ Bruise Tobacco Roots in a mortar, and rub the teeth and gums with a linen cloth dipped in the Juice. You may also put some Tobacco bruised between the fingers into the hollow of the tooth. Or take the green Leaves of a Plum-tree, or of Rosemary, and boil them in Lees of Wine or Vinegar; gargle the mouth with the Wine as hot as you can bear it, and repeat it frequently. 28. _For rotten Teeth._ Make a balsam with a sufficient quantity of Honey, two scruples of Myrrh in fine powder, a scruple of Gum Juniper, and ten grains of Roch Alum. Frequently apply this mixture to the decayed tooth. 29. _A liquid Remedy for decayed Teeth._ Take a pint of the Juice of the Wild Gourd, a quarter of a pound of Mulberry Bark, and Pellitory of Spain, each three ounces; Roch Alum, Sal Gem, and Borax, of each half an ounce. Put these ingredients into a glass vessel, and distill in a sand heat to dryness; take of this liquor and Brandy, each an equal part, and wash the mouth with them warm. This mixture removes all putridity, and cleanses away dead flesh. 30. _A Powder to clean the Teeth._ Take Dragon's Blood and Cinnamon, of each one ounce and a half, Burnt Alum, or Cream of Tartar, one ounce; beat all together into a very fine powder, and rub a little on the teeth every other day. 31. _A Remedy for sore Gums and loose Teeth._ Boil Oak Leaves in spring-water, and add to the decoction a few drops of Spirit of Sulphur. Gargle the mouth with a little of this liquor every morning while necessary. 32. _An approved Receipt against that troublesome Complaint, called the Teeth set on Edge._ Purslain, Sorrel, Sweet or Bitter Almonds, Walnuts, or burnt Bread, chewed, will certainly remove this disagreeable sensation. 33. _A Liquid for cleansing the Teeth._ Take Lemon Juice, two ounces, Burnt Alum and Salt, of each six grains; boil them together about a minute in a glazed pipkin, and then strain through a linen cloth. The method of application is to wrap a bit of clean rag round the end of a stick, dipping it in the Liquid, and rub it gently against the teeth. You must be careful not to have too much of the Liquid on the rag, for fear it should excoriate the gums or inside of the mouth. This application ought not to be used above once every two or three months. 34. _A sure Preservative from the Tooth Ache, and Defluxions on the Gums or Teeth._ After having washed your mouth with water, as cleanliness and indeed health requires, you should every morning rince the mouth with a tea spoonful of Lavender-Water mixed with an equal quantity of warm or cold water, whichever you like best, to diminish its activity. This simple and innocent remedy is a certain preservative, the success of which has been confirmed by long experience. 35. _A Method to make the Teeth beautifully white._ Take Gum Tragacanth, one ounce; Pumice-stone, two drachms; Gum Arabic, half an ounce; and Crystals of Tartar, finely powdered, one ounce; dissolve the Gums in Rose-water, and adding to it the powder, form the whole into little sticks, which are to be dried slowly in the shade, and afterwards kept for use. 36. _Or,_ Take dried Leaves of Hyssop, Wild Thyme, and Mint, of each half an ounce; Roch Alum, prepared Hartshorn, and Salt, of each a drachm; calcine these ingredients together in a pot placed on burning coals; when sufficiently calcined, add of Pepper and Mastic, each half a drachm, and of Myrrh a scruple; reduce the whole into a fine powder, and make them into a proper consistence with Storax dissolved in Rose-water. Rub the teeth with a small bit of this Mixture every morning, and afterwards wash the mouth with warm Wine. 37. _Or,_ Dip a piece of clean rag in Vinegar of Squills, and rub the teeth and gums with it. This not only whitens, but fastens and strengthens the roots of the teeth, and corrects an offensive breath. 38. _Or,_ Take Rose-water, Syrup of Violets, clarified Honey, and Plantain-water, of each half an ounce; Spirit of Vitriol one ounce; mix them together. Rub the teeth with a linen rag moistened in this Liquor, and then rince the mouth with equal parts of Rose and Plantain-water. 39. _Or,_ Rub them well with Nettle or Tobacco Ashes, or rather with Vine Ashes mixed with a little Honey. 40. _A Powder to cleanse the Teeth._ Take prepared Coral and Dragons-blood, of each an ounce; Cinnamon and Cloves, of each six drachms; Cuttle-bone, and calcined Egg-shells, of each half an ounce; Sea Salt decrepitated, a drachm, all in fine powder: mix them in a marble mortar. 41. _The following was communicated by Mr. Rae, Surgeon Dentist, in the Adelphi, London._ Take of Cuttlefish-bone, and the finest prepared Chalk, each half an ounce; Peruvian Bark, and Florentine Iris Root, each two drachms: reduce the whole into a fine Powder, and mix them. This may be coloured with a little Rose Pink, and scented with a few drops of Oil of Cinnamon. 42. _Or,_ Take Pumice-stone prepared, Sealed Earth, and Red Coral prepared, of each an ounce; Dragons-blood, half an ounce; Cream of Tartar, an ounce and a half; Cinnamon, a quarter of an ounce; and Cloves, a scruple: beat the whole together into a Powder. This Powder serves to cleanse, whiten, and preserve the Teeth; and prevents the accidents that arise from the collection of Tartar or any other foulness about them. 43. _An efficacious Tooth-Powder._ Take Myrrh, Roch Allum, Dragon's Blood, and Cream of Tartar, of each half an ounce; Musk, two grains; and make them into a very fine powder. This, though simple, is an efficacious dentifrice; but nothing of this kind should be applied too frequently to the teeth for fear of hurting the enamel. 44. _A Powder to cleanse the Teeth._ Take Pumice-Stone and Cuttle-fish Bone, of each half an ounce; Tartar vitriolated, and Mastich, of each a drachm; Oil of Rhodium four drops: mix all into a fine powder. 45. _A Tincture to strengthen the Gums and prevent the Scurvy._ Take an ounce of Peruvian Bark grossly powdered, infuse it a fortnight or longer in half a pint of Brandy. Gargle the mouth every night or morning, with a tea spoonful of this Tincture diluted with an equal quantity of Rose-water. 46. _Manner of preparing the Roots for cleaning the Teeth, according to Mr. Baumè._ The roots that are used to clean the teeth are formed at both ends like little brushes; and in all probability were substituted in the room of Tooth-brushes, on account of their being softer to the gums and more convenient. They are used in the following manner; one of the ends is moistened with a little water, dipped into the Tooth-Powder, and then rubbed against the teeth till they look white. Fibrous and woody Roots are best formed into little brushes, and on this account deserve a preference to others. The Roots are deprived of their juicy parts by boiling them several times in a large quantity of fresh Water. When Lucern Roots are used, those of two years growth are chosen, about the thickness of one's little finger; such as are thicker, unsound or worm-eaten, being rejected. They are cut into pieces about six inches long, and, as we have just observed, are boiled in water till all the juicy parts are extracted. Being then taken out, they are left to drain; after which each end of the roots is slit with a penknife into the form of a little brush, and they are slowly dried to prevent their splitting. In the same manner are prepared Liquorice Roots. Marsh-mallow Roots are prepared in an easier way; but, on account of the mucilage they contain, they become very brittle when dry. Such as are large and very even are made choice of, and rasped with a knife to remove the outer bark. They are dyed red by infusing them in the same dye as is used to colour spunges. When the Roots have remained twenty-four hours in the dye, they are taken out, slowly dried, and varnished with two or three coats of a strong Mucilage of Gum Tragacanth, each being suffered to dry before another is laid on. The whole is afterwards repeatedly anointed with Friars Balsam, in order to form a varnish less susceptible of moisture. Lucern and Liquorice Roots are dyed and varnished in the same manner: those of Marsh-mallows, from the loss of their Mucilage, considerably diminish in thickness during the time they stand in infusion. 47. _Manner of preparing Sponges for the Teeth_ For this purpose very thin sponges are made choice of, which are to be washed in several waters; squeezing them with the hands, to loosen and force away the little shells that adhere to their internal surface. Being afterwards dried, they are neatly cut into the shape of balls about the size of small eggs; and when they have undergone this preparation, they are dyed in the following manner. Take Brazil Wood rasped, four ounces; Cochineal bruised, three drachms; Roch Alum, half an ounce; Water, four pints: put them into a proper vessel, and boil till one half of the Liquor is consumed. Then strain the decoction through a piece of linen, and pour it hot upon the sponges, which are to be left in infusion twelve hours; at the expiration of which time, they are to be repeatedly washed in fresh water, as long as any colour proceeds from them. Being dried, they are afterwards dipped in Spirit of Wine, aromatized with Essential Oil of Cinnamon, Cloves, Lavender, &c. The sponges are then fit for use, and when dried by squeezing, are kept in a wide-mouthed glass-bottle well corked. 48. _Rules for the Preservation of the Teeth and Gums._ The teeth are bones thinly covered with a fine enamel, which is more or less strong in different persons. When this enamel is wasted, either by a scorbutic humour or any external cause, the tooth cannot long remain sound, and must therefore be cleaned, but with great caution. For this purpose the best instrument is a small piece of wood, like a butcher's skewer, rendered soft at the end. It is generally to be used alone; only once in a fortnight dip it into a few grains of gunpowder, which has previously been bruised. This will remove every spot and blemish, and give your Teeth an inconceivable whiteness. It is almost needless to say, that the mouth must be well washed after this operation; for besides the necessity of so doing, the salt-petre, &c. used in the composition of Gunpowder, would, if it remained, prove injurious to the gums, &c. but has not, nor can have, any bad effect in so short a time. It is necessary to observe, that very near the gums of people whose teeth are otherwise good, there is apt to grow a crust, both within and without, which, if neglected, separates the gums from the fangs of the teeth; and the latter being by this means left bare, are frequently destroyed. This crust must therefore be carefully scraped off. 49. _For stopping the Decay of Teeth._ Take of Bole Armenian the quantity of a large nutmeg, a like quantity of Roch Alum, two penny-worth of Cochineal bruised, and a small handful of the Chips of Lignum Vitæ; simmer them with four ounces of Honey in a new pipkin, for a little time, well stirring them all the while, till the ingredients are mixed. In using it, take a large skewer, on the end of which is tied a piece of linen rag; dip the rag in the medicine, and rub the teeth and gums with it. The longer you abstain from spitting, after the use of the remedy, the better. Wash the mouth well at least once every day, particularly after meals, first rubbing the teeth with salt upon the end of your finger. Teeth much decayed, or useless, should be drawn, if the operation can be performed with safety. The reader will find several other receipts for the Teeth, under the article of Waters. WATERS. 50. _The Celestial Water._ Take the best Cinnamon, Nutmegs, Ginger, Zedoary, Galangals, and White-Pepper, of each an ounce; six Lemon-peels, pared thin; two handfuls of Damascene Grapes; as much Jujebs; a handful of Pith of Dwarf-Elder; four handfuls of Juniper-berries perfectly ripe; Fennel-Seeds, Flowers of Sweet Basil, St. John's-wort, Rosemary, Marjoram, Pennyroyal, Stechas, Musk Roses, Rue, Scabious, Centaury, Fumitory, and Agrimony, of each a handful; Spikenard, Aloes-Wood, Grains of Paradise, Calamus Aromaticus, Mace, Gum Olibanum, and Yellow Sanders, of each two ounces; Hepatic Aloes, fine Amber and Rhubarb, of each two drachms. All these drugs being procured good in their kind, beat in a mortar those that ought to be pulverized, and put the whole, thoroughly mixed together, into a large strong glass alembic; pouring as much genuine brandy upon them as will rise at least three fingers breadth above the ingredients. Then having well closed the mouth of the alembic, bury the vessel fifteen days in warm horse-dung, and afterwards distil the Tincture in balneo Mariæ, the water almost boiling hot. When you perceive the water in the receiver change its colour, instantly stop the process, and separate the phlegm from the spirit, by another distillation conducted in the same manner. The liquor thus obtained is the genuine Celestial Water. _Note_, when you perceive this second water begin to lose its transparency, and incline to a reddish colour, put it by in a strong glass bottle closely stopped, and dissolve in the residue half a pound of the best Treacle, with as much Venice Turpentine and fresh Oil of Almonds. Place the alembic in a sand heat, and urge the fire to the first degree, to have the genuine Balsamic Oil, which ought to be of the consistence of clarified Honey. If a person rubs himself in the morning with this water on the forehead, eyelids, back of the head, and nape of the neck, it renders him quick and easy of conception, strengthens the memory, enlivens the spirits, and greatly comforts the sight. By putting a few drops with a bit of cotton up the nostrils, it becomes a sovereign cephalic, and cleanses the brain of all superfluous cold and catarrhal humours. If a table spoonful is drank every third day, it tends to preserve the body in vigour. It is an excellent remedy against asthmatic complaints, and corrects an offensive breath. 51. _A Receipt to make the genuine Hungary-Water._ Put into an alembic a pound and a half of fresh pickt Rosemary Flowers; Pennyroyal and Marjoram Flowers, of each half a pound; three quarts of good Coniac Brandy; having close stopped the mouth of the alembic to prevent the Spirit from evaporating, bury it twenty-eight hours in horse-dung to digest, and then distil off the Spirit in a water-bath. A drachm of Hungary-Water diluted with Spring-Water, may be taken once or twice a week in the morning fasting. It is also used by way of embrocation to bathe the face and limbs, or any part affected with pains, or debility. This remedy recruits the strength, dispells gloominess and strengthens the sight. It must always be used cold, whether taken inwardly as a medicine, or applied externally. 52. _Another Receipt to make Hungary-Water._ Fill a glass or stone cucurbit half full of fresh gathered Rosemary-tops picked in their prime; pour on them as much Spirit of Wine as will thoroughly soak them. Put the vessel in a water-bath, and having closely luted on the head and receiver, leave it to digest on a gentle fire for three days; at the expiration of which period unlute the vessel, and pour back into the cucurbit whatever liquor you find in the receiver. Then lute your cucurbit again, and encrease the fire so as to cause the Spirit to rise fast over the helm. When about two thirds of the liquor are drawn off, remove the fire, and let the vessel stand to cool; you will find in the receiver an excellent Hungary-Water, which is to be kept in a glass bottle closely stopped. Hungary-water must be drawn off with a brisk fire, or the Spirit of Wine will come over the helm, very little impregnated with the essence of Rosemary. 53. _Directions for making Lavender-Water._ Fill a glass or earthen body two thirds full of Lavender Flowers and then fill up the vessel with Brandy or Melasses Spirits. Let the Flowers stand in infusion eight days, or less if straitened for time; then distil off the Spirit, in a water-bath with a brisk fire, at first in large drops or even a small stream, that the Essential Oil of the Flowers may rise with the Spirit. But as this cannot be done without the phlegm coming over the helm at the same time, the Spirit must be rectified. The first distillation being finished, unlute the still, throw away what remains in the body, and, fill it with fresh Flowers of Lavender, in the proportion of two pounds of Lavender Flowers to one pint of Spirit; pour the Spirit already distilled according to the foregoing directions, on the Lavender Flowers, and distil a second time in a vapour-bath. 54. _Another Method._ Take fresh or dried Lavender Flowers, sprinkle them with White Wine, Brandy, Melasses Spirit, or Rose-water; let them stand in infusion for some days, and then distil off the Spirit. The distilled water will be more odoriferous, if the Flowers are dried in the sun in a glass bottle close stopped, and White Wine afterwards poured upon them. If you would have speedily, without the trouble of distillation, a water impregnated with the flavour of Lavender, put two or three drops of Oil of Spike, and a lump of Sugar, into a pint of clear Water, or Spirit of Wine, and shake them well together in a glass phial, with a narrow neck. This Water, though not distilled, is very fragrant. 55. _To make Rose-Water._ To make an excellent Rose-water, let the Flowers be gathered two or three hours after sun-rising in very fine weather; beat them in a marble mortar into a paste, and leave them in the mortar soaking in their juice, for five or six hours; then put the mass into a coarse canvas bag, and press out the Juice; to every quart of which add a pound of fresh Damask Roses, and let them stand in infusion for twenty-four hours. Then put the whole into a glass alembic, lute on a head and receiver, and place it on a sand heat. Distil at first with a gentle fire, which is to be encreased gradually till the drops follow each other as quick as possible; draw off the water as long as it continues to run clear, then put out the fire, and let the alembic stand till cold. The distilled water at first will have very little fragrancy, but after being exposed to the heat of the sun about eight days, in a bottle lightly stopped with a bit of paper, it acquires an admirable scent. 56. _Or,_ Infuse in ten or twenty pints of Juice of Damask Roses, expressed in the manner above described, a proportionable quantity of Damask Rose Leaves gathered with the usual precautions. After standing in infusion twenty-four hours, pour the whole into a short-necked alembic, distil in a sand heat, and draw off as much as possible, taking care not to leave the residuum quite dry, for fear the distilled water should have an empyreumatic or still-burnt flavour. After emptying the alembic, pour the distilled water a second time into it, and add a good quantity of fresh picked Damask Roses. Lute it well, placing it again in a sand heat, and repeat the distillation. But content yourself this time with a little more than half the water you put back into the alembic. To impress on Rose-water the utmost degree of fragrancy of which it is susceptible, it is necessary to expose it to the genial warmth of the sun. Rose-water is an excellent lotion for the eyes, if used every morning, and makes a part in all collyriums prescribed for inflammations of these parts; it is also proper in many other complaints. 57. _To make Orange-Flower Water._ Having gathered (two hours before sun-rise, in fine weather) a quantity of Orange-Flowers, pluck them leaf by leaf, and throw away the stalks and stems: fill a tin cucurbit two thirds full of these picked Flowers; lute on a low bolt-head, not above two inches higher than the cucurbit; place it in balneo Mariæ, or a water-bath, and distill with a strong fire. You run no risk from pressing forward the distillation with violence, the water-bath effectually preventing the Flowers from being burnt. In this method you pay no regard to the quantity, but the quality of the water drawn off. If nine pounds of Orange Flowers were put into the still, be satisfied with three or four quarts of fragrant water; however, you may continue your distillation, and save even the last droppings of the still, which have some small fragrancy. During the operation, be careful to change the water in the refrigeratory vessel as often as it becomes hot. Its being kept cool prevents the distilled water from having an empyreumatic or burnt smell, and keeps the quintessence of the Flowers more intimately united with its phlegm. 58. _Another Method._ Take four pounds of unpicked Orange Flowers, bruise them in a marble mortar, and pour on them nine quarts of clear Water. Distil in a cold still, and draw off five or six quarts, which will be exquisitely fragrant. If you are desirous of having it still higher flavoured, draw off at first full seven quarts, unlute the still and throw away the residuum; empty back the water already distilled, and add to it two pounds of fresh Orange Flowers bruised. Again luting the still, repeat the distillation, and draw of five or six quarts. Then stop, being careful not to draw off too much water, lest the Flowers should become dry and burn too. The use of Orange-Flower Water is very extensive. It is high in esteem for its aromatic perfume; and is used with success for hysteric complaints. Waters from all kinds of Flowers are made in the same manner as Orange-Flower and Rose-water; but waters from dried odoriferous plants, such as Thyme, Hyssop, Marjoram and Wormwood, are made as follows. Fill two thirds of a large stone jar with the tops of the plant you propose to distil; boil, in a sufficient quantity of water, some twigs or tops of the same plant; and when one half of the water has evaporated, pour the remainder into a jar over the flowers, and let them stand to infuse three or four days; then distil them in a common or cold still. Care, however, must be taken not to distil to dryness, lest you risque the bottom of the vessel; to prevent which accident, the best way is never to draw off more than two thirds of the liquor put into the still. If you be desirous that the distilled water should acquire a higher flavour, after the first distillation unlute the still, throw out what remains at the bottom, and fill it half full of fresh tops of the plant, pouring on them the water already distilled; repeat the distillation, and this second time the water drawn off will be highly odoriferous. If the plant contains a large portion of Essential Oil, it will not fail to float on the top of the liquor contained in the receiver, and may be separated by the usual method. 59. _Magisterial Balm-Water._ Take half a pound of Cinnamon, six ounces of Cardamon-seeds, and the same quantity of green Aniseeds; Cloves, four ounces; Coriander-seeds, eight ounces: beat these spices in a marble mortar, and putting them afterwards into a stone jar, add the Yellow Rind of eight Lemons, a pound of Juniper-berries bruised, twelve handfuls of Balm gathered in its prime, six handfuls of Rosemary-tops, as much Sage, Hyssop, and Angelica, Sweet Marjoram and Thyme, of each six handfuls; Wormwood a handful; cut the herbs very small, putting them into the jar with the spices, and pour on four gallons of Brandy or Melasses Spirits. When they have stood in infusion eight days, empty the ingredients and liquor into an alembic of a common height, and distil in a water-bath. At first draw off ten quarts, which are to be thrown again into the alembic, continue the same degree of fire for some time, then gradually lessen it till the aromatic spirit comes off in quick drops. Continue your distillation in this manner till you perceived the phlegm rise, which is easily known by the weakness of the Spirit, and when the process is ended, expose the aromatic spirit which has been drawn off to the rays of the sun, in a glass bottle, stopped only with a loose paper cork, to give the fiery particles an opportunity of evaporating. What remains in the body of the still is not to be considered as wholly useless. After evaporating it to dryness, burn the residuum of the plants and aromatics; and when the whole mass is reduced to ashes, throw them into a vessel of boiling water, in which let them remain two or three minutes on the fire. Then remove the vessel, and let the water stand till cold, when it is to be filtered through blotting paper: The water, which appears limpid, is to be set on the fire again, and wholly evaporated. At the bottom of the vessel, which ought to be a new-glazed earthen pot, will remain a pure white fixed salt, which may be dissolved in the Magisterial Balm-water. This water is highly esteemed, and has even acquired a reputation equal to that of Hungary-water, (the receipt for preparing which has been already given) and in particular cases is preferable. 60. _Compound Balm-Water, commonly called Eau de Carmes._ Take of the fresh Leaves of Balm, a quarter of a pound; Yellow Rind of Lemons, two ounces; Nutmegs and Coriander-seeds, of each one ounce; Cloves, Cinnamon, and Angelica Root, of each half an ounce: having pounded the spices and seeds; and bruised the leaves and roots, put them with a quart of Brandy into a glass cucurbit, of which stop the mouth, and set it in a warm place, where let it remain two or three days. Then add a pint of simple Balm-water, and shake the whole well together; after which distil in a vapour bath till the ingredients are left almost dry; and preserve the water thus obtained, in bottles well stopped. This water has been long famous at Paris and London, and carried thence to most parts of Europe. It has the reputation of being a cordial of very extraordinary virtues, and not only of availing in all lowness of spirits, but even in apoplexies. It is also much esteemed in cases of the gout in the stomach; whence the Carmelite Friars, who originally were in possession of the secret, have reaped great benefit from the sale of this water. 61. _Sweet Honey-Water._ Take of good French Brandy, a gallon; of the best Virgin Honey and Coriander-seeds, each a pound; Cloves, an ounce and half; Nutmegs, an ounce; Gum Benjamin and Storax, of each an ounce; Vanilloes No. 4; the Yellow Rind of three large Lemons: bruise the Spices and Benjamin, cut the Vanilloes into small pieces, put all into a cucurbit, and pour the Brandy on them. After they have digested forty-eight hours, distil off the Spirit in a retort with a gentle heat. To a gallon of this water, add of Damask Rose-water and Orange Flower-water, of each a pint and a half; Musk and Ambergrise, of each five grains; first grind the Musk and Ambergrise with some of the water, and afterwards put all into a large matrass, shake them well together, and let them circulate three days and nights in a gentle heat. Then, letting the water cool, filtre and keep it for use, in a bottle well stopped. It is an antiparalytic, smooths the skin, and gives one of the most agreeable scents imaginable. Forty or sixty drops put into a pint of clear water, are sufficient to wash the hands and face. 62. _Sweet-scented Water._ Take Orange Flower-water and Rose-water, of each an equal quantity; put them into a large wide-mouthed glass, and strew upon the surface gently as much Jasmine Flowers as will cover it; then tie the mouth of the glass so carefully that the Flowers be not shook down to the bottom. Repeat the process, letting each quantity of the Flowers remain five or six days, until the water is strongly scented with them. Then dissolve Ambergrise and Musk, of each a scruple, in a few ounces of the water, which filtre and put to the rest. This water may also be made by putting the whole into a retort with a sufficient quantity of Jasmine Flowers, and drawing it off in a vapour bath into a receiver well luted. This is an excellent perfume, and taken inwardly, is of service in some nervous cases and languors. 63. _German sweet-scented Water._ Begin with infusing for eight days in two quarts of Vinegar, two handfuls of Lavender Flowers, as many Provence Roses picked from the stalks, Wild Roses, and Elder Flowers. While they stand in infusion prepare a simple odoriferous water as follows: Put into a glass body the Yellow Rind of three Lemons, sweet Marjoram, Lilies of the Valley and Lavender Flowers, of each two handfuls; pour on them a pint of double distilled Rose-water, and a quart of Spring-water. Lute on a bolt-head, place the alembic in a sand heat, fix on a receiver, and leave matters in this state two days, then light a fire under it and distil quick. When you have drawn off a quart, stop your distillation, and keep this simple odoriferous water for the following use. Take wild Thyme, sweet Marjoram, sweet Basil, and Thyme, of each a handful; Florentine Orrice and Cinnamon, of each half an ounce; Cloves, Mace, purified Storax, and Benjamin, of each three drachms; Labdanum, two drachms; Aspalathum, half an ounce; Socotrine Aloes, half a drachm; put all these ingredients, thoroughly bruised, into a stone jar, and add to them the Vinegar infusion, the distilled odoriferous water, and a quart of Frontiniac, Mountain, or Cowslip Wine. Stir them well together, and leave the whole to digest for fifteen days, at the expiration of which time, empty the infusion into a glass body, large enough to contain a sixth part more liquor; lute on the head, place it in a sand heat, and begin your distillation with a very gentle fire, increasing it gradually. It sometimes happens that the phlegm of the Vinegar comes over the helm first; when that is the case, set it aside as useless. As soon as the Spirit begins to rise, which you will directly perceive by its aromatic flavour, fix a receiver on the beak of the alembic, and distil off about three pints. Keep this by itself as the most spirituous part of your preparation; and continue to draw off the remainder as long as it runs clear. The German sweet-scented Water is penetrating and incisive, admirably revives the vital spirits, removes headaches, comforts the heart, is excellent against unwholesome air, and of course a preservative from contagion. 64. _Imperial Water._ Take five quarts of Brandy, in which dissolve an ounce of Frankincense, Mastic, Benjamin, and Gum Arabic; add half an ounce of Cloves and Nutmegs; an ounce and a half of Pine-nut Kernels, and sweet Almonds; with three grains of Musk. Bruise these ingredients in a marble mortar, distil in a vapour bath, and keep the water that is drawn off in a glass bottle, close stopped. This water takes away wrinkles, and renders the skin extremely delicate; it also whitens the Teeth, and abates the tooth-ache, sweetens the breath, and strengthens the gums. Foreign ladies prize it highly. 65. _Odoriferous Water._ Take sweet Basil, Mint, sweet Marjoram, Florentine Orrice-root, Hyssop, Balm, Savory, Lavender, and Rosemary, of each a handful; Cloves, Cinnamon, and Nutmegs, of each half an ounce; three or four Lemons, cut in thick slices; infuse them three days in a good quantity of Rose-water; distil in a water bath with a gentle fire, and add to the distilled water a scruple of Musk. 66. _Or,_ Take sweet Marjoram, Thyme, Lavender, Rosemary, Pennyroyal-buds, red Roses, Violet-flowers, Clove-july-flowers, Savory, and Orange-peels, of each equal parts; infuse in White Wine till they entirely sink to the bottom of the Wine; then distil in an alembic, two or three times. Keep the Water in bottles well corked; and preserve the residuum as a perfume. 67. _The Ladies Water._ Take two handfuls and a half of Red Roses; Rosemary Flowers, Lavender, and Spikenard, of each a handful; Thyme, Chamomile Flowers, Sage of Virtue, Pennyroyal, and Marjoram, of each a handful; infuse in White Wine twenty-four hours; then put the whole into an alembic; sprinkle it with good White Wine, and throw on it a powder, composed of an ounce and a half of choice Cloves, Gum Benjamin, and Storax, strained, each two drachms. The distilled Water is to be kept in a bottle well stopped. 68. _A beautifying Wash._ Take equal parts of White Tansey, and Rhubarb Water, and to every half pint add two drachms of Sal Ammoniac. This fluid is applied with a feather or hair pencil, three or four times a day, to pimples or tetters, on any part of the body. 69. _A Cosmetic Water._ Wash the face with the tears that issue from the Vine, during the months of May and June. 70. _An Excellent Cosmetic._ Pimpernel Water is so sovereign a beautifier of the complexion, that it ought always to have a place on a Lady's toilet. 71. _Venice Water, highly esteemed._ In the month of May, take two quarts of Cow's Milk, which pour into a bottle with eight Lemons and four Oranges, sliced; add an ounce of Sugar Candy, and half an ounce of Borax; distil in a water bath or sand heat. This water is counterfeited at Bagdat in Persia, in the following manner. Take twelve Lemons peeled and sliced, twelve new-laid Eggs, six Sheeps Trotters, four ounces of Sugar Candy, a large slice of Melon, and another of Pompion, with two drachms of Borax; distil in a large glass alembic with a leaden head. 72. _A Balsamic Water._ Take a pound of Venice Turpentine; Oil of Bays, Galbanum, Gum Arabic, Ivy Gum, Frankincense, Myrrh, Hepatic Aloes, Aloes-wood, Galangals, Cloves, Comfrey, Cinnamon, Nutmegs, Zedoary, Ginger, and White Dittany, each three ounces; Borax, four ounces; Musk, a drachm; Ambergrise, a scruple; after bruising such of the ingredients as are capable of being powdered, infuse the whole in six quarts of Brandy; and distil it. The Balsamic Water drawn off will be good to strengthen the limbs, and cause that beauty and vigour which so much delights the eye. 73. _Angelic Water, of a most agreeable Scent._ Put into a large alembic the following ingredients, Benjamin, four ounces; Storax, two ounces; Yellow Sanders, an ounce; Cloves, two drachms; two or three bits of Florentine Orrice, half the Peel of a Lemon, two Nutmegs, half an ounce of Cinnamon, two quarts of Rose-water, a pint of Orange Flower-water, and a pint of Magisterial Balm-water. Put the whole into an alembic well luted; distil in a water bath; and what you draw off will prove an exquisite Angelic Water. 74. _Nosegay or Toilet Water._ Take Honey-water, an ounce; Eau sans Pareille, two ounces; Jasmine-water, not quite five drachms; Clove-water, and Violet-water, of each half an ounce; Cyprus-water, sweet Calamus-water, and Lavender-water, of each two drachms; Spirit of Neroli or Oranges ten drops; mix all these Waters together, and keep the mixture in a vial close corked. This water has a delightful scent; but its use is only for the toilet. 75. _Spirit of Guaiacum._ Spirit of Guaiacum is prepared by infusing two ounces of Guaiacum Shavings in a quart of Brandy, ten or twelve days, shaking the vessel now and then. The Tincture is then filtred through paper, and used to gargle the mouth in the same manner as the Vulnerary-water. 76. _The Divine Cordial._ To make this, take, in the beginning of the month of March, two ounces of the Roots of the true Acorus, Betony, Florentine Orrice-roots, Cyprus, Gentian, and sweet Scabious; an ounce of Cinnamon, and as much Yellow Sanders; two drachms of Mace; an ounce of Juniper-berries; and six drachms of Coriander-seeds; beat these ingredients, in a mortar, to a coarse powder, and add thereto the outer Peel of six fine China Oranges; put them all into a large vessel, with a gallon and a half of Spirit of Wine; shake them well, and then cork the vessel tight till the season for Flowers. When these are in full vigour, add half a handful of the following: viz. Violets, Hyacinths, Jonquils, Wall Flowers, Red, Damask, White, and Musk Roses, Clove-july-flowers, Orange Flowers, Jasmine, Tuberoses, Rosemary, Sage, Thyme, Lavender, sweet Marjoram, Broom, Elder, St. John's-wort, Marigold, Chamomile, Lilies of the Valley, Narcissuses, Honeysuckle, Borage, and Bugloss. Three seasons are required to procure all these Flowers in perfection; Spring, Summer, and Autumn. Every time you gather any of these Flowers, add them immediately to the infusion, mixing them thoroughly with the other ingredients; and three days after you have put in the last Flowers, put the whole into a glass cucurbit, lute on the head carefully, place it in a water bath over a slow fire, keep the receiver cool, and draw off five quarts of Spirit, which will prove of a rare quality. As a medicine, it is far more efficacious than Balm-water; and for its fine scent, one of the best perfumes. 77. _Compound Cyprus Water._ Take a gallon of Spirit of Jasmine, infuse in it half an ounce of Florentine Orrice grossly powdered, a quarter of an ounce of bruised Angelica-seeds, three scraped Nutmegs, three ounces of White Musk-roses bruised, a drachm of Spirit of Orange, and fifteen drops of Essence of Ambergrise. If it is not the season for Roses, when you make this Water, put instead of them a pint of Rose-water scented with Musk, and if that cannot be procured, use common Rose-water; draw off the Spirit in a water bath, and in a stream like a thread; taking care to place the receiver in cold water, that the Spirit may cool as fast as possible and thereby the better preserve its perfume. 78. _Imperial Water._ Put into a gallon of Brandy, a quarter of a pound of picked Violets, an ounce of Florentine Orrice, a quarter of a pound of Double Jonquils, two ounces of picked Orange Flowers, two Ounces of White Musk-roses, three ounces of Tuberoses, a drachm of Mace, half a drachm of Cloves, an ounce of Quintessence of Bergamot, and an ounce of Quintessence of Oranges. All the Flowers must be gathered in their proper season. Observe to put into the Brandy at the same time with the Violets, the Orrice, Mace, and Cloves, in gross powder, then add the different Flowers as they come in season, remembering not to add the quintessences, till after the Tuberoses, which are the last Flower. Every time you put in a fresh Flower, shake the vessel, and cork it very tight. Eight days after the Tuberoses have been infused, put the whole into a glass body, lute on the head carefully, and place under the receiver an earthen vessel filled with cold water, that the Spirit may cool as fast as it comes over, by which means its scent will be the better preserved. You may draw off two quarts of a rectified Spirit, that will give perfect satisfaction to the most delicate judge. 79. _All Flower Water._ Pour into a large vessel five quarts of strong Spirit of Wine, and infuse in it the following Flowers, as they come in season: Violets, Hyacinths, and Wall Flowers, of each a quarter of a pound; single and double Jonquils, of each two ounces; a quarter of a pound of Lilies of the Valley, and the same quantity of Spanish Jasmine; half an ounce of Rosemary Flowers; an ounce of Elder Flowers; two ounces of Wild, Damask, and White Roses, bruised; three ounces of Orange Flowers; a quarter of a pound of Clove-july-flowers, Syringo Blossoms, Tuberoses, and Tops of Mint in Flower; and thirty drops of Quintessence of Musk-seed. The latter, however, need not be added till the time of distillation, which must not be till three days after the last Flowers have been infused. Perform the operation in a water bath, and having carefully luted the head and receiver, which must be placed in a tub of cold water, to preserve the scent, draw off about three quarts and a pint with a moderate fire, then change the receiver, fix on another, and draw off another pint, which, though of an inferior quality, is well worth preserving. 80. _A curious Water, known by the Name of the Spring Nosegay._ Take six ounces of Hyacinths, a quarter of a pound of picked Violets, the same quantity of Wall Flowers picked, and Jonquils; an ounce of Florentine Orrice bruised; half an ounce of Mace grossly powdered; and two ounces of Quintessense of Orange. Put the whole (the Jonquils, Wall Flowers, and Lilies of the Valley excepted) about the end of March, into a glass body, with a gallon of strong Spirit of Wine; bruise the Hyacinths, Violets, Orrice, and Mace; and towards the end of April, add the Jonquils, when in their perfection, that is to say, when full blown. A few days after, put in the Wall Flowers, the Petals only; then add the Lilies of the Valley, carefully picked, and shake all the ingredients well: Eight days after having put in this last Flower, empty the infusion into an alembic, lute on a head and receiver, which must be placed in cold water, and distil in a water bath, with a gentle fire. From the above quantity three quarts of excellent Spirit may be drawn off, that justly deserves the appellation of the Spring Nosegay. 81. _A Cosmetic Water, of great Use to prevent Pits after the Small-Pox._ Dissolve an ounce and a half of Salt in a pint of Mint-water; boil them together, and skim the Liquor. This is a very useful Wash for the face after the Small-Pox, in order to clear away the scabs, allay the itching, and remove the redness. 82. _A Cooling Wash._ Infuse in a sufficient quantity of clear Water, some Bran, Yolks of Eggs, and a grain or two of Ambergrise, for three or four hours; then distil the Water, which will prove an excellent Cosmetic, and clear the skin surprisingly. It is of service to keep it in the sun eight or ten days, in a bottle well corked. The distilled Waters of Melons, Bean Flowers, the Wild-Vine, green or unripe Barley, and the Water that is found in vesicles on the leaves of the elm-tree, may also be used for the same intention. 83. _An excellent Water to clear the Skin, and take away Pimple_s. Take two quarts of Water, in which a quantity of Horse-beans has been boiled till quite soft; put it into an alembic, and add two handfuls of Pimpernel, the same quantity of White Tansy, a pound of Veal minced small, six new-laid Eggs, and a pint of White-Wine Vinegar; distil this mixture in a water-bath, and it will afford an excellent Lotion to remove all eruptions on the face, if washed with it every night and morning. 84. _Another._ Knead a Loaf with three pounds of Wheaten Flour, a pound of Bean Flour, and Goats Milk, with Mild Yeast or Leaven. Bake it in an oven, scoop out the crumb, and soak it thoroughly in new Goats Milk and six Whites of Eggs; add an ounce of calcined Egg-shells. Mix all well together, and distil in a sand heat. You will obtain an excellent cosmetic water, by washing with which every day, the face will become smooth and clear. 85. _Venetian Water to clear a Sun-burnt Complexion._ Take a pint of Cow's Milk, or, in the month of May, a pint of the Water that distils from the Vine when wounded, eight Lemons and four Seville Oranges cut in thin slices, two ounces of Sugar Candy, half an ounce of Borax in fine powder, and four Narcissus Roots beaten to a paste; distil these ingredients in a vapour-bath. Rectify the distilled Liquor by the same method, and keep it in a bottle closely corked. 86. _A Water for Pimples in the Face._ Boil together a handful of the herbs Patience, and Pimpernel in Water; and wash yourself every day with the decoction. 87. _A Fluid to clear a tanned Skin._ Take unripe Grapes, soak them in Water, sprinkle them with Alum and Salt, then Wrap them up in paper, and roast them in hot ashes; squeeze out the Juice, and wash the face with it every morning, it will soon remove the Tan. 88. _A Fluid to whiten the Skin._ Take equal parts of the Roots of Centaury and the White Vine, a pint of Cow's Milk, and the crumb of a Wheaten Loaf; distil in a glass alembic. The distilled Water, for use, must be mixed with an equal quantity of Hungary Water: it then admirably clears the complexion. The distilled Waters of Fennel, and White Lilies, with a little Gum Mastic, will produce the same effect. 89. _A Beautifying Wash._ Put into a cucurbit five pints of French Brandy; add to it a pound and a half of Crumb of Bread, three ounces of Plum-tree-gum, two ounces of Litharge of Silver in fine powder, and four ounces of sweet Almonds. The ingredients are to be beat together into a paste, and left to digest in the Spirit eight days; then distil in a vapour-bath, and wash the face and hands with the water thus obtained. It must be suffered to dry on the skin without being wiped off, and the complexion will presently become clear and glossy. 90. _A distilled Water that tinges the Cheeks a beautiful Carnation Hue._ Take two quarts of White Wine Vinegar, three ounces of Isinglass, two ounces of bruised Nutmegs, and six ounces of Honey; distil with a gentle fire, and add to the distilled Water a small quantity of Red Sanders, in order to colour it. Before the Tincture is used, a Lady should wash herself with Elder-flower Water, and then the cheeks will become of a fine lively vermillion, that cannot be distinguished from the natural bloom of youth. 91. _A Cosmetic Water._ Take three Aron Roots minced small, three Melons of a middling size, three Cucumbers, four new laid Eggs, a slice of a Pumkin, two Lemons, a pint of Whey, a gallon of Rose-water, a quart of Water-lily-water, a pint of Plantain, as much White Tansy-water, and half an ounce of Borax. Distil the whole together in a vapour-bath. 92. _A Water, christened, The Fountain of Youth._ Take an ounce of Sulphur Vivum; Olibanum and Myrrh, each two ounces; six drachms of Amber; a quart of Rose-water; distil the whole in a vapour-bath, and wash yourself with the Water every night going to rest: the next morning wash yourself with weak Barley-water, and your complexion will have a youthful air. It is asserted also that the distilled Water of green Pine-apples takes away wrinkles, and gives the complexion an air of youth. 93. _A Water to preserve the Complexion._ Mix together Water-lily Water, Bean-flower Water, Melon Water, Cucumber Water, and Lemon Juice, of each an ounce; to which add, of Bryony, Wild Succory, White Lilies, Borrage and Bean Flowers, each a handful. Take seven or eight White Pigeons, pick them, and cut off their heads and pinions, mince the rest of them small, and put them into an alembic with the other ingredients. To these add four ounces of Sugar Candy in powder, as much Camphor, and the Crumb of three small Wheaten Loaves, each weighing about half a pound; digest the whole eighteen or twenty days in an alembic, then distil, and keep the Water that is drawn off in proper vessels for use. Before washing with it, carefully observe to cleanse the face with the following composition. Take a quarter of a pound of the Crumb of Rye Bread hot from the oven, the Whites of four new laid Eggs, and a pint of White Wine Vinegar; beat the whole well together, and strain through a linen rag. The use of these two preparations perfectly cleanses and clears the skin, preserves its freshness, and prevents wrinkles. 94. _A Water that gives a Gloss to the Skin._ Take a handful of Bean, Elder, and Bugloss Flowers, a small Pigeon clean drawn, the Juice of two Lemons, four ounces of Salt, and five ounces of Camphor; distil them in a vapour-bath; add to the distilled Water a few grains of Musk, and expose it to the sun for the space of a month, observing to take the vessel within doors every night. The way to use this Water, is to dip the corner of a fine napkin in it, and gently rub the face. 95. _A Preservative from Tanning._ Infuse in clean Water for three days a pound of Lupines, then take them out, and boil them in a copper vessel with five quarts of fresh Water. When the Lupines are boiled tender, and the Water grows rather ropy, press out the Liquor, and keep it for use. Whenever you are under a necessity of exposing yourself to the sun, wash the face and neck with this preparation. The Oil of unripe Olives, in which a small quantity of Gum Mastic has been dissolved, possesses the same virtue. 96. _To remove Freckles._ Take Houseleek, and Celandine, of each an equal quantity; distil in a sand heat, and wash with the distilled Water. 97. _Or,_ Apply the Juice of Onions to the part affected. 98. _Or,_ Boil Ivy Leaves in Wine, and foment the face with the decoction. 99. _A Water to prevent Freckles, or Blotches in the Face._ Take Wild Cucumber-roots and Narcissus-roots, of each an equal quantity; dry them in the shade, and reduce them to a very fine powder, putting them afterwards into strong French Brandy, with which wash the face, till it begins to itch; and then wash it with cold water. This method must be repeated every day till a perfect cure is obtained, which will soon happen, for this water has a slight caustic property, and of course must remove all spots on the skin. 100. _Or,_ Take a handful of fresh Wood-ashes, boil them in a pint of clear Water, till one half is wasted away, then pour off the Liquor as long as it runs clear; boil it again a little while, and filter it through coarse paper. 101. _A Water to improve the Complexion._ Take Snakeweed-roots and Narcissus-roots, of each an equal quantity; a pint of Cow's Milk, and the Crumb of a Wheaten Loaf; distil these ingredients in a glass alembic. This Water should be mixed with an equal quantity of Hungary-water. 102. _Or,_ Take Chick Peas, French Beans, and Garden Beans, of each four ounces; peel off their skins, powder them, and infuse in a quart of White Wine; add the Gall of an Ox, and the Whites of fifteen new laid Eggs. Mix the ingredients thoroughly, distil in a glass alembic with a sand heat; and wash the face with the distilled Water, as occasion requires. 103. _A Cosmetic Water._ Take a pound and a half of fine Wheaten Bread, four ounces of Peach Kernels, the same quantity of the four Cold Seeds, viz. Gourd-seed, Cucumber-seed, Melon-seed, and Lettuce-seed; the Whites of twelve new laid Eggs, the Juice of four Lemons, three ounces of Sugar Candy, a gallon of Goat's Milk; mix the whole together, and distil in a vapour-bath. To every two quarts of the distilled Water, add a quarter of a pint of Spirit of Cherries. 104. _Or,_ Take six Aron Roots minced small, six ounces of Bran, four ounces and a half of Myrrh in powder, three pints of Milk, and the same quantity of Wine; distil according to the rules of art; and to the distilled Water add a small bit of Alum. 105. _A simple Balsamic Water, which removes Wrinkles._ Take Barley-water, strained through a piece of fine linen cloth, and drop into it a few drops of Balm of Gilead; shake the bottle for several hours, until the Balsam is entirely incorporated with the Water, which is known by the turbid milky appearance of the Mixture. This greatly improves the complexion, and preserves the bloom of youth. If used only once a day, it takes away wrinkles, and gives the skin a surprising lustre. Before this fluid is used, the face should be washed clean with rain water. 106. _A Water to change the Eye-brows black._ First wash your eyebrows with a decoction of Gall Nuts; then wet them with a pencil or little brush dipped in a solution of Green Vitriol, in which a little Gum Arabic has been dissolved, and when dry, they will appear of a beautiful black colour. 107. _To remove Worms in the Face._ Make use of the distilled Waters of the Whites of Eggs, Bean Flowers, Water Lilies, White Lilies, Melon Seeds, Iris Roots, Solomon's Seal, White Roses, or crumb of Wheaten Bread, either mixed together, or separately, with the addition of the White of a new-laid Egg. 108. _The Duchess de la Vrilliere's Mouth-Water._ Take Cinnamon, two ounces; Cloves, six drachms; Water Cresses, six ounces; fresh Lemon Peel, an ounce and a half; Red Rose Leaves, an ounce; Scurvy Grass, half a pound; Spirit of Wine, three pints. Bruise the Spices, cut the Water Cresses and Scurvy Grass small, and macerate the whole in Spirit of Wine, in a bottle well corked, during twenty-four hours; then distil to dryness in a vapour-bath, and afterwards rectify the distilled Water, by repeating the same process. This Water strengthens the gums, prevents the scurvy, and cures aphthæ, or little ulcerations in the mouth. It is used to gargle the mouth with, either by itself, or diluted with water, as occasion may require. 109. _Another Water for the Teeth, called Spirituous Vulnerary Water._ For this intention are commonly used Spirituous Waters, that are no ways disagreeable; waters proper to strengthen and fortify the gums, as Spirituous Vulnerary Water tinctured with Cochineal, or Seed Lac; Guaiacum Water, or the Duchess de la Vrilliere's Water above described. To tinge Vulnerary Water, put any quantity into a glass matrass, and infuse in it some bruised Cochineal; then filter the Vulnerary Water, and use it to gargle the mouth, after which the teeth are to be cleaned with Tooth Powder. This, when found too strong, may be lowered by the addition of Spring Water. 110. _Receipt to make Vulnerary Water._ Take fresh gathered Leaves of Sage, Angelica, Wormwood, Savory, Fennel, and spiked Mint, of each four ounces; Leaves of Hyssop, Balm, Sweet Basil, Rue, Thyme, Marjoram, Rosemary, Origanum, Calamint, and Wild Thyme, fresh gathered, of each four ounces; the same quantity of Lavender Flowers, and a gallon of rectified Spirit of Wine. Cut the Herbs small, infuse them ten or twelve hours in Spirit of Wine, and then distil in a vapour-bath. Preserve the Spirit drawn off, in a bottle well corked. 111. _A Water for the Gums._ Take of the best Cinnamon, an ounce; Cloves, three drachms; the Yellow Peel of two Lemons; Red Rose Leaves, half an ounce; Water Cresses, half a pound; Scurvy Grass, four ounces; rectified Spirit of Wine, three gallons: bruise the Spices, and infuse the whole a sufficient time in the Spirit in a glass vessel; then distil off the Spirit for use, in a vapour-bath. 112. _Another, prepared by Infusion._ Take two drachms of Cinnamon, finely powdered; half a drachm of Cloves, in fine powder; and half an ounce of Roch Alum; pour on them three gallons of boiling Water; when cold, add six ounces of Plantain Water, half an ounce of Orange-flower Water, a quarter of an ounce of Essence of Lemons, and a gill and a half of rectified Spirit of Wine; let the whole stand together in digestion four and twenty hours, then filter through paper, and reserve the clear water for use. 113. _Or,_ Take Mace, Cinnamon, Cloves, Pellitory of Spain, and Terra Sigillata, or Sealed Earth, of each half an ounce; beat the whole together in a mortar, and infuse it a month in a quart of Spirit of Wine. Strain off the Spirit, and add eight ounces of Spirit of Scurvy Grass. Drop six or seven drops in a glass of very clear Water, and rince the mouth; afterwards rubbing the gums with conserve of Hips acidulated with five or six drops of Spirit of Vitriol. 114. _Another Water for the Gums._ Take of the best Cinnamon, an ounce; Cloves, three drachms; the Peel of two Lemons; half an ounce of Red Rose Leaves; half a pound of Water Cresses, four ounces of Scurvy Grass, and three gallons of rectified Spirit of Wine. Bruise the Spices, and let the whole stand in digestion in a glass vessel twenty-four hours; then distil in a vapour-bath. 115. _A simple Depilatory._ Oil of Walnuts frequently rubbed on a child's forehead, will prevent the hair from growing on that part. 116. _Prepared Sponges for the Face._ Steep in Water some time the finest and thinnest Sponges you can pick out; wash them well, dry them, and soak them in Brandy a whole day; then squeeze the Brandy out, and dry them again. Lastly, dip them in Orange-flower Water, and let them remain in it eleven or twelve hours. When squeezed, and thoroughly dried, they are fit for use. 117. _Spirit of Roses._ To make the inflammable Spirit of Roses, take twenty pounds of Damask Roses, beat them to a Paste, in a marble mortar; put this Paste, layer by layer, with sea salt, into a large stone jar, or two jars, if one is not large enough to contain the whole quantity; that is to say, sprinkle every layer of the Paste about half an inch thick with Salt; and press the layers of Roses as close together as possible. Cork the jar with a waxed cork, cover the upper-most end of the cork, and the edges of the mouth of the jar, with wax also, and place it six weeks, or two months, in a vault, or some other cool place. At the expiration of this period, open the jar; if it exhales a strong vinous smell, the fermentation has arrived at its proper height; but if you do not perceive such an odour, throw into the jar a little Yeast, and stop it close in the same manner as before. A strong fermentation having been excited, take five or six pounds of your fermented Rose Paste, put it into a common cucurbit, and distil it with a very gentle fire in a vapour-bath. When you have drawn off as much water as you can, unlute the alembic; throw away what remains in the cucurbit, take five or six pounds more of the fermented Paste of Roses, and put it into the cucurbit, with the Water already drawn; distil in a vapour-bath with such a degree of fire, as will cause the distilled Water to run off in a middling sized stream. When you can draw off no more, empty the cucurbit, fill it again with fresh fermented Paste of Roses, and pour on it all the distilled Water that the preceding distillations have produced. Distil as before; and repeat these operations, till you have used all your fermented Paste of Roses. Every time you open the jar, be careful to cork it close, otherwise the most spirituous particles will evaporate. After the last distillation, you will have obtained a very fine scented Water, but not very spirituous, because loaded with a considerable quantity of phlegm; and it must therefore be rectified. For this purpose make choice of a very long necked glass matrass of a reasonable size, fill it about three parts full with your unrectified Spirit of Roses; fit on a bolt-head, and receiver; lute the joints carefully, and distil in a vapour-bath with a very slow fire. When you have drawn off about a tenth part of what was put into the matrass, let the vessel cool, and set apart the Spirit that is found in the receiver. What remains in the matrass must not be thrown away as useless, for it is a Rose-water far superior to what is prepared according to the usual method. After the first rectification of a part of the Spirit, repeat the same operation with another part, till the whole is rectified, and then rectify them all together once more. After this last operation, you will obtain a highly penetrating and inflammable Spirit of Roses. The phlegmatic part that remains in the matrass may be added to that procured from the preceding rectifications, and the whole kept for use in a cellar or other cool place in a bottle, well corked. The scent of inflammable Spirit of Roses is extremely sweet; if only two drops of it are mixed with a glass of Water, they impart to the Water so high a perfume, that it exceeds the very best Rose-water. 118. _Inflammable Spirits of all Kinds of Flowers._ To distil an inflammable Spirit from Flowers of all kinds, the preceding method must be used; as also to procure one from all kinds of vegetables. Only observe that in plants, and dried flowers, as Thyme, Betony, Mint, Stechas, Violets, and Jasmine, the Seeds must be bruised with the Flowers and Roots; as they also must with the Flowers of the Tuberose Lily, Angelica, Iris; in odoriferous Fruits, as Oranges, Lemons, Citrons, &c. add the Rind of those Fruits to the Flowers; and to the Flowers of Elder, Juniper, Lily of the Valley, and Acacia, &c. add the Berries well moistened; whether green or dry is of no signification. ESSENCES. 119. _Method of extracting Essences from Flowers._ Procure a wooden box lined with tin, that the wood may not communicate any disagreeable flavour to the Flowers, nor imbibe the Essence. Make several straining frames to fit the Box, each about two inches thick, and drive in them a number of hooks, on which fix a piece of callicoe stretched tight. The utmost care is requisite, to have the straining cloths perfectly clean and dry before they are used. After having caused the cloths to imbibe as much Oil of Ben as possible, squeeze them a little, then stretch and fix them on the hooks of the frames; put one frame thus completed at the bottom of the box, and upon its cloth strow equally those flowers, the essence of which you intend to extract; cover them with another frame, on the cloth of which you are to strow more flowers, and continue to act in the same manner till the box is quite filled. The frames being each about two inches thick, the flowers undergo very little pressure, though they lye between the cloths. At the expiration of twelve hours, apply fresh flowers in the same manner, and continue so to do for some days. When you think the scent powerful enough, take the cloths from the frames, fold them in four, roll them up, and tie them tight with a piece of whip-cord, to prevent their stretching out too much, then put them into a press, and squeeze out the oil. The press must be lined with tin, that the wood may not imbibe any part of the oil. Place underneath a very clean earthen or glass vessel to receive the essence, which is to be kept in bottles nicely corked. The essence of one kind of flower only, can be made in a box at the same time, for the scent of one would impair that of another. For the same reason, the cloths that have been used to extract the essence of any particular flower, cannot be used to extract the essence of another, till washed clean in a strong lye, and thoroughly dried in the open air. This method is of great use to obtain the scent of flowers which afford no Essential Oil by distillation, such as Tuberoses, Jasmine, and several others. 120. _Or,_ Take any flowers you please, and put them in a large jar, layer by layer, mixed with Salt, as directed for inflammable Spirit of Roses, till the jar is quite full; then cork it tight, and let it stand in a cellar, or some other cool place, for forty days; at the expiration of which time, empty the whole into a sieve, or straining cloth, stretched over the mouth of a glazed earthen or stone pan, to receive the essence that drains from the flowers upon squeezing them gently. Afterwards put the essence into a glass bottle, which must not be filled above two thirds; cork it tight, and expose it to the heat of the sun in fine weather, five and twenty or thirty days, to purify the essence, a single drop of which will be capable of scenting a quart of Water or any other Liquid. 121. _Essence of Ambergrise._ Take of Ambergrise a quarter of an ounce; the same quantity of Sugar Candy; Musk, half a drachm; and Civet, two grains; rub them together, and put the mixture into a Phial: pour upon it a quarter of a pint of tartarised Spirit of Wine, stop close the Phial, which set in a gentle sand heat for four or five days, and then decant the clear Tincture for use. This makes the best of perfumes; the least touch of it leaves its scent upon any thing a great time; and in constitutions where such sweets are not offensive to the head, nothing can be a more immediate Cordial. 122. _A Remedy for St. Anthony's Fire or Erysipelatous Eruptions on the Face._ Take Narcissus Roots, an ounce; fresh Nettle-seeds, half an ounce; beat them together into a soft Paste with a sufficient quantity of White Wine Vinegar, and anoint the eruptions therewith every night; or, bathe the part affected with the Juice of Cresses. FLOWERS. 123. _Manner of drying Flowers, so as to preserve their natural Colours._ Take fine White Sand, wash it repeatedly, till it contains not the least earth or salt, then dry it for use. When thoroughly dry, fill a glass or stone jar half full of Sand, in which stick the Flowers in their natural situation, and afterwards cover them gently with the same, about the eighth part of an inch above the Flower. Place the glass in the sun, or, if in winter-time, in a room where a constant fire is kept, till the Flower is perfectly dried. Then remove the Sand with the utmost precaution, and clean the Leaves with a feather brush. Particular Flowers lose in some measure their natural lively colours, but this may be helped by the assistance of art. Roses and other Flowers of a delicate colour, recover their natural lustre by being exposed to a moderate vapour of Brimstone; but Crimson or Scarlet Flowers, by being exposed to the vapour of a solution of Tin in Spirit of Nitre. The vapour of a solution of Filings of Steel in Spirit of Vitriol, restores to the Leaves and Stalk, their primitive green colour. This method succeeds perfectly well in single Flowers. There are some difficulties with respect to Pinks, Carnations, and other double Flowers; to succeed with them, split the cup on each side, and when the Flower is quire dry, glue it together with Gum-water; or prick the cup in different parts with a large pin. As to the scent, which is in great measure lost in drying, it may be restored, by dropping into the middle of the Flower a drop of its Essential Oil; for instance, a drop of Oil of Roses on a Rose, Oil of Cloves on a Clove-july-flower, Oil of Jasmine on a Jasmine Flower. 124. _A Secret to preserve Flowers._ Fill an earthen, copper, or wooden vessel half full of sifted Sand, then fill it up to the brim with clear Spring Water, and stir the Sand well with a stick in order to detach the earthy particles. When the Sand has thoroughly settled, pour off the turbid Water by inclination, add fresh Water, and continue to wash the Sand, till all the Water that floats on its surface remains perfectly clear. The Sand being thus cleansed, expose it to the heat of the sun a sufficient time, to exhale entirely its humidity. Prepare for every Flower an earthen or tin vessel of a proper size, make choice of the finest, most perfect, and driest Flowers of their respective kinds, and be careful to leave the stalks of a good length. Place them upright in the vessel, with one hand as lightly as possible, about two or three inches below the rims, so as not to touch the sides, or each other; and with the other hand gradually pour on them the Sand till the stalk is quite covered; then lightly cover the Flower itself, separating the Leaves a little. The Tulip requires a farther operation. The triangular top that rises out of the middle of the cup, must be cut off, by which means the Leaves of the Flower will adhere better to the Stalk. When the vessel is filled with Flowers, leave it a month or two exposed to the rays of the sun; and the Flowers when taken out, though dry, will be very little inferior in beauty to new-blown Flowers, but will have lost their scent. 125. _Another Secret to preserve Flowers._ Take the finest River Sand you can get, after having sifted it several times through a fine sieve, throw it into a glass vessel full of clear Water, and rub it a good while between your fingers to render it still finer; then pour off the Water by inclination, and dry the Sand in the sun. The Sand being thus prepared, bury the Flowers gently in it with their Leaves and Stalk, disposing them in such a manner that their form may not be in the least injured. After having thus kept Flowers some time, till their humid particles are entirely evaporated, take them out, and inclose them in bottles, well corked; secure them from all changes of the atmosphere, but let them enjoy a temperate warmth; for if the heat is too great, the colours fade; and if not kept sufficiently warm, the humidity of the Flowers will not wholly evaporate. 126. _Another Method of preserving Flowers a long while, in their natural Shape and Colour._ Take the finest River Sand, divested of whatever impurities it may contain; then dry it in the sun or a stove, sift it through a sieve, and only make use of the finest part. Procure a Tin Box, or a Wooden Box lined with Tin, of any size you think proper, cover the bottom of the Box three or four inches deep with prepared Sand, and stick in it the Stalks of the Flowers in rows, but in such a manner that none of the Flowers may touch each other, afterwards filling the vacuities between the Stalks with Sand. Then spread the Sand all round the Flowers, which cover with a layer about two or three inches thick. Put this Box in a place exposed to the sun, or in some warm situation, for the space of a month. With respect to Tulips, the pistil that rises in the middle, and contains the Seed, must be dexterously cut out, and the empty space filled with Sand: too many Flowers should not be put into the same Box, nor should the Box be too large. GLOVES. 127. _White Gloves Scented With Jasmine after the Italian manner._ Take half an ounce of White Wax; dissolve it over a gentle fire in two ounces of Oil of Ben. Dress your skins with this Liquid, dry them on lines, and clean them well with the purest water; when they are dried and properly stretched, make them up into gloves, which are to have the Jasmine Flowers applied to them eight days according to the usual method; then bring them into shape, and fold them smooth. This manner of working them up, communicates to the gloves the property of retaining the scent of the Flowers much better than those that are drest otherwise, and likewise imparts to them the virtue of preserving the hands and arms delicately soft and white. 128. _Gloves scented without Flowers._ Take an ounce of Liquid Storax, an ounce of Rose-wood, the same quantity of Florentine Orrice, and half an ounce of Yellow Sanders. Beat the three last articles into a very fine powder, and add to it the Storax, with the earths that you use to dye your gloves, and a little Gum Arabic. Then take an equal quantity of Rose and Orange Flower Water, to temper this composition which you lay on your gloves; when they are dry, rub them well, and fold them up; then dress them afresh with a little Gum Water, in which has been dissolved some powder of Florentine Orrice; hang them up to dry, and afterwards bring them into form, and fold them up as fit for use. 129. _White Gloves scented with Ketmia or Musk Seed._ Take an ounce of Yellow Sanders, an ounce of Florentine Orrice, an ounce of Gum Benjamin, two ounces of Rose-wood, and a drachm of Storax; reduce the whole to fine powder, with as much Ceruss as you choose. Mix them with Rose-water, and dress your gloves with the mixture as neatly as you can for the first coat; then rub them well, and open them when they are thoroughly dry. Use the same for the second coat, with the addition of a little Gum Arabic. For the third coat, levigate on a marble, eight grains of Ketmia Seed, four grains of Civet, a little Oil of Ben, and a very little Gum Tragacanth, dissolved in Rose-water; add to this composition a quarter of a pint of Orange Flower Water; after having applied this third coat to your gloves, bring them into form, before they get thoroughly dry. 130. _To colour Gloves a curious French Yellow._ Take Chalk and Wood Ashes, of each an equal quantity, and make a strong Lye of them; then strain off the clear Liquor, and simmer it over the fire with a little Turmeric in powder, and a very little Saffron, till it becomes pretty thick; after which set the liquor by to cool, and it is fit for use. 131. _An excellent Perfume for Gloves._ Take Ambergrise, a drachm; the same quantity of Civet; and of Orange Flower Butter, a quarter of an ounce; mix these ingredients well, and rub them into the gloves with fine Cotton Wool, pressing the perfume into them. 132. _Or,_ Take of Essence of Roses, half an ounce; Oil of Cloves and Mace, of each a drachm; Frankincense, a quarter of an ounce; mix them, and lay them in papers between your gloves. Being hard pressed, the gloves will take the scent in twenty-four hours, and afterwards hardly ever lose it. 133. _An excellent Receipt to clear a tanned Complexion._ At night going to rest, bathe the face with the Juice of Strawberries, and let it lie on the part all night, and in the morning wash yourself with Chervil Water. The skin will soon become fair and smooth. 134. _Or,_ Wash yourself with the Mucilage of Linseed, Fleawort, Gum Tragacanth, or Juice of Purslain mixed with the White of an Egg. BREATH. 135. _To sweeten the Breath._ At night, going to bed, chew about the quantity of a small Nut of fine Myrrh. 136. _Or,_ Chew every night and morning a Clove, a piece of Florentine Orrice-root, about the size of a small bean, or the same quantity of Burnt Alum. OILS. 137. _A Cosmetic Oil._ Take a quarter of a pint of Oil of Sweet Almonds, fresh drawn; two ounces of Oil of Tartar per Deliquium; and four drops of Oil of Rhodium: mix the whole together, and make use of it to cleanse and soften the skin. 138. _Another Cosmetic Oil._ Take a pint of Cream, infuse in it a few Water Lilies, Bean Flowers, and Roses; simmer the whole together in a vapour-bath, and keep the Oil that proceeds from it in a vial, which is to be left for some time exposed to the evening dews. 139. _Oil of Wheat._ This Oil is extracted by an Iron Press, in the same manner as Oil of Almonds. It is excellent for Chaps in either the lips or hands, tetterous eruptions, and rigidity of the skin. 140. _Compound Oil, or Essence of Fennel._ Take five pints of the best French Brandy, and the same quantity of White-Wine; three quarters of a pound of bruised Fennel Seeds, and half an ounce of Liquorice Root sliced and bruised. Put the whole into an alembic, close the mouth with Parchment, and set it in a hot house, or in hot ashes, two days; then distil off the Liquor with an uniform middling fire. What remains after the distillation of the Essence, and is called the White Drops, is only fit to wash the hands with. 141. _To make Oil of Tuberoses and Jasmine._ Bruise a little the Tuberoses or Jasmine Flowers in a marble mortar with a wooden pestle; put them into a proper vessel, with a sufficient quantity of Oil of Olives, and let them stand in the sun in a close stopped vessel twelve or fifteen days to infuse; at the expiration of which time, squeeze the Oil from the Flowers. Let the Oil stand in the sun to settle, then pour it clear off the dregs. This Oil is very fragrant, and well impregnated with the Essential Oil of these Flowers. Infuse a fresh parcel of Flowers, newly gathered, in the same Oil, and proceed as before: repeat this operation twelve or fourteen times, or even oftener if necessary, till the Oil is fully impregnated with the flavour of the Flowers. Some people use Oil of Ben instead of Sallad Oil, which in our opinion is preferable, being infinitely less apt to grow rancid. The Oils of Tuberoses, and Jasmine Flowers are of use for the Toilet on account of their fragrancy. There are cases in which they may be successfully used externally by way of friction, to comfort and strengthen the nerves, and brace up the skin when too much relaxed. 142. _An Oil scented with Flowers for the Hair._ Sallad Oil, Oil of Sweet Almonds, and Oil of Nuts, are the only ones used for scenting the hair. Blanch your Almonds in Hot Water, and when dry, reduce them to powder; sift them through a fine sieve, strewing a thin layer of Almond-powder, and one of Flowers, over the bottom of the Box lined with Tin. When the box is full, leave them in this situation about twelve hours; then throw away the Flowers, and add fresh ones in the same manner as before, repeating the operation every day for eight successive days. When the Almond-powder is thoroughly impregnated with the scent of the Flower made choice of, put it into a new clean Linen Cloth, and with an Iron Press extract the Oil, which will be strongly scented with the fragrant perfume of the Flower. ESSENTIAL OILS, OR QUINTESSENCES. 143. _Essential Oil, commonly called Quintessence of Lavender._ Fill a cucurbit two thirds full with unwashed Lavender Flowers, pour upon them as much clear Water as will float about two inches above the Flowers. Fit to the cucurbit a head with a short neck, and lute on the refrigeratory vessel. Distil in the common manner with a fire of such a degree of strength as will cause the distilled water to run off in a thick thread. The phlegm and spirit will come over in a considerable quantity, and the Essential Oil, with which Lavender greatly abounds, will soon appear floating on the surface of the Water in the receiver; which is to be separated according to the rules of art. As soon as you perceive that no more Oil drops into the receiver, which generally happens to be the case a good while before the phlegm is entirely drawn off, finish your distillation. If you want a larger quantity of Quintessence, empty the still, put fresh Flowers, and adding the phlegm and spirit drawn off by the former distillation, instead of so much common Water, distil as before, till you have obtained a sufficient quantity. This Quintessence possesses great medicinal virtues, and is particularly serviceable in vapourish and hysteric disorders. 144. _To make Essence of Cinnamon._ Take half a pound of Cinnamon, reduce it in a mortar to an impalpable powder, put it into a very long necked matrass, pour on it as much highly rectified Spirit of Wine as will cover the powder about an inch. Stop the matrass with a found cork coated with bees-wax, and expose it to the sun for a whole month, observing to shake it well twice a day. At the expiration of the month, uncork the matrass, using the utmost precaution not to disturb the sediment; and gently pour off the Tincture into a clean vial. 145. _To make Quintessence of Cloves._ Take a pound of Cloves, beat them in a mortar, put them into a glass vessel, and pour on them a gallon of hot but not boiling water, cork the bottle close with a waxed cork, placed in a warm place, and let the Cloves infuse three weeks or a month; then empty the contents of the bottle into a middling sized still, fit on a low head with a short neck, and distil in the common manner, with a fire of such a degree of fierceness as to make the distilled Water run off in a stream, resembling a thick thread. The Quintessence will come over with the Spirit, mixed with a large quantity of Phlegm; but being heavier than either of those substances, will be found precipitated to the bottom of the receiver. Separate it in the usual manner, and keep it for use in a vial closely corked. Then unlute your still, and throw in the spirituous Water that remains after the separation of the Quintessence; distil it a second time, and you will obtain a small quantity more, which may be added to the former. 146. _A Cosmetic Juice._ Make a hole in a Lemon, fill it with Sugar Candy, and close it nicely with leaf Gold applied over the Rind that was cut out; then roast the Lemon in hot ashes. When desirous of using the Juice, squeeze out a little through the hole, and wash the face with a napkin wetted with it. This Juice greatly cleanses the skin, and brightens the complexion. VIRGIN's MILK. 147. _A safe and approved Cosmetic._ Take equal parts of Gum Benjamin, and Storax, and dissolve them in a sufficient quantity of Spirit of Wine. The spirit will then become a reddish Tincture, and exhale a very fragrant smell. Some people add a little Balm of Gilead. Drop a few Drops into a glass of clear Water, and the Water, by stirring, will instantly become milky. Ladies use it successfully to clear the complexion, for which purpose nothing is better, or indeed so innocent and safe. 148. _Another, very easily made._ Beat a quantity of Houseleek in a marble mortar, squeeze out the Juice and clarify it. When you want to use it, pour a few drops of rectified Spirit on the Juice, and it will instantly turn milky. It is a very efficacious remedy for a pimpled face, and preserves the skin soft and smooth. 149. _Another._ Take a half-gallon bottle, pour into it a quart of Spirit of Wine, and a pint of clear Brandy; then add a quarter of a pound of the finest Gum Benjamin, two ounces of Storax, half an ounce of Cinnamon, two drachms of Cloves, and a Nutmeg, all bruised, and four drops of Quintessence of Egyptian Ketmia. Carefully cork the bottle, and expose it to the sun a month; but take it within doors in rainy weather. At the month's end, gently draw off the clear Tincture; and you will have a fragrant Milk, which is used by pouring a few drops on a wet napkin. 150. _A Liniment to destroy Vermin._ Take an ounce of Vinegar, the same quantity of Stavesacre, half an ounce of Honey, and half an ounce of Sulphur; mix into the consistence of a soft liniment, with two ounces of Sallad Oil. LOTIONS. 151. _A Lotion to strengthen the Gums, and sweeten the Breath._ Take Mountain Wine, and the distilled Water of Bramble Leaves, of each a pint; half an ounce of Cinnamon; a quarter of an ounce of Cloves; the same quantity of Seville Orange-peel; Gum Lacque and Burnt Alum, of each a drachm, all in fine powder. Having added two ounces of fine Honey, put the whole into a glass bottle, and let them infuse on hot ashes the space of four days. On the fifth day squeeze the Liquor through a thick linen cloth, and preserve it in a bottle, well corked. When the gums are relaxed, and want bracing, take a spoonful of this Liquid, and pour it into a glass. First use one half to rince the mouth; and after retaining it a little, spirt it out. Use the remainder in the same way, rubbing the gums with one of your fingers; and afterwards rince the mouth with warm-water. Repeat the operation every morning, or twice a day, if occasion requires. To render this remedy more efficacious, add to the whole quantity of the Lotion half a pint of Cinnamon Water, distilled from White Wine. The eastern nations, to procure a sweet breath, to render the teeth beautifully white, and fasten the gums, frequently chew boiled Chio Turpentine, or Gum Mastic. The Indians who live beyond the Ganges chew it all day long, and are so used to this habit, that they cannot without difficulty refrain from it. The Spirituous Water of Guaiacum possesses the property of giving ease in the tooth-ache, and fastening the teeth in their sockets. The mouth is to be gargled with a quantity mixed in a glass of clear Water. 152. _Another Lotion to fasten the Teeth and sweeten the Breath._ Pour three pints of Water into an earthen or stone jar, dip in it four different times a red hot poker, and then immediately add an ounce of bruised Cinnamon, six grains of Burnt Alum, an ounce of powdered Pomegranate Bark, three ounces of fine Honey; of Vulnerary Water, Rue Water, and Myrtle Water, each a quarter of a pint; and of Brandy, half a pint. The whole being well mixed, tie a wet bladder over the mouth of the jar, and let it stand in the sun, or any warm place, for twenty-four hours; then strain off the Liquor through a thick linen cloth, or strong straining bag. Add to it two ounces of Spirit of Scurvy-grass, and keep it in a bottle, well corked. It is used in the same manner as the preceding Lotion. 153. _An admirable Lotion for the Complexion._ After having washed the face with Soap and Water, wash yourself with the following lixivium. Take clear Lees prepared from Vine Ashes, and to every pound of it, add an ounce of calcined Tartar, two drachms of Gum Sandarach, and as much Gum Juniper. Let this Lotion dry on the face without wiping it off, and afterwards wash yourself with Imperial Water. 154. _An admirable Varnish for the Skin._ Take equal parts of Lemon Juice, and Whites of new laid Eggs, beat them well together in a glazed earthen pan, which put on a slow fire, and keep the mixture constantly stirring with a wooden spatula, till it has acquired the consistence of soft butter. Keep it for use, and at the time of applying it, add a few drops of any Essence you like best. Before the face is rubbed with this varnish, it will be proper to wash with the distilled Water of rice. This is one of the best methods of rendering the complexion fair, and the skin smooth, soft, and shining. 155. _A Liniment to destroy Nits._ Take Oil of Bays, Oil of Sweet Almonds, and old Hogs Lard, of each two ounces, powdered Stavesacre, and Tansy Juice, of each half an ounce; Aloes, and Myrrh, of each a quarter of an ounce, the smaller Centaury and Salt of Sulphur, of each a drachm; mix the whole into a liniment. Before you use it, wash the hair with Vinegar. 156. _A Liniment to change the Beard and Hair black._ Take Oil of Costus, and Oil of Myrrh, of each an ounce and a half; mix them well in a leaden mortar, adding of Tar, the expressed Juice of Walnut Leaves, and Gum Labdanum, each half an ounce; Gall Nuts in fine powder, and Black Lead, of each a drachm and a half; the same quantity of Frankincense; and a sufficient quantity of Mucilage of Gum Arabic, prepared with a decoction of Gall Nuts. Apply it to the head and chin after being clean shaved. 157. _A Depilatory Liniment._ Take a quarter of a pound of Quick-lime, an ounce and a half of Orpiment, an ounce of Florentine Orrice, half an ounce of Sulphur, the same quantity of Nitre, and a pound or pint of a Lixivium made of Bean-stalk Ashes; boil the whole to a proper consistence, which may be known by dipping a wet feather into it. It is boiled enough when the feathery part of the quill easily separates from the other. Then add half an ounce of Oil of Lavender, or any aromatic Essence, and mix into a Liniment, with which if you rub the hair that grows on any part of the body, it will immediately drop off. When the hair is removed, foment the part with Oil of Sweet Almonds, or Oil of Roses. 158. _Another._ Take a quarter of a pound of Gum Ivy dissolved in Vinegar, a drachm of Orpiment, a drachm of Ant Eggs, and two drachms of Gum Arabic dissolved in Juice of Henbane, in which half an ounce of Quick-lime has been boiled. Make the whole into a liniment with a sufficient quantity of Fowls Grease, and apply a little to the part where you would wish to destroy the Hair, after being clean shaved. 159. _An excellent Lip-Salve._ Take an ounce of Myrrh, as much Litharge in fine powder, four ounces of Honey, two ounces of Bees-wax, and six ounces of Oil of Roses; mix them over a slow fire. Those who are inclined may add a few drops of Oil of Rhodium, and some Leaf Gold. 160. _Or,_ Take Armenian Bole, Myrrh, and Ceruss in fine powder, of each an ounce; mix with a sufficient quantity of Goose-grease into a proper consistence. It presently cures chaps in any part of the body. 161. _A Liniment to promote the Growth and Regeneration of the Nails._ Take two drachms of Orpiment, a drachm of Manna, the same quantity of Aloes and Frankincense, and six drachms of White Wax. Make them into a liniment, which apply to the part with a thumb-stall. NAILS. 162. _A certain Remedy for Whitlows; a Disorder that frequently affects the Fingers._ Take Pellitory of the Wall, cut as small as possible, and mix it with a proportionable Quantity of Hog's Lard; wrap it up in several papers, one over the other, and place it in warm ashes, which though not hot enough to burn the paper, yet retain sufficient heat to roast the Pellitory of the Wall, and incorporate it thoroughly with the Lard. Then spread this Liniment on a piece of brown paper, wrap it round the Whitlow, and apply a fresh dressing, at least twice a day. That it may give the speedier relief, spread the ointment thick. 163. _Another._ Take Vine Ashes, with which make a strong Lee; and in this, warmed, let the finger soak a good while. To keep up an equal degree of warmth, every minute pour into the vessel a little more hot lees. Repeat this operation two or three times, and you will speedily find the good effect of it. PERFUMES. 164. _Scented Tables or Pastils._ Beat into a fine powder, and sift through a hair sieve, a pound of the Marc or Residuum left in the still, after making Angelic Water; then put it into a mortar, with a handful of fresh-gathered Rose Leaves, and a small porringer full of Gum Tragacanth softened with Rose Water. Beat the whole into a Paste; roll it out on a dresser with a rolling-pin, and cut it into Lozenges with a knife. To form scented Pastils, roll up bits of this Paste in the shape of a cone, that they may stand upright, and set them by to dry. These kind of Pastils are lighted in the same manner as a candle. They consume entirely away; and, while burning, exhale a fragrant smoke. 165. _A pleasant Perfume._ Take a drachm of Musk, four Cloves, four ounces of Lavender-seed, a drachm and a half of Civet, and half a drachm of Ambergrise; heat your pestle and mortar, and rub the Musk, Cloves, and Lavender-seeds together, with a lump of Loaf Sugar and a wine-glass full of Angelic or Rose-water. Take a handful of powder, and incorporate it well with this mixture, then sift it through a sieve; add two or three pounds more powder, or even a larger quantity, till the perfume is brought to a proper degree of strength. As to the Civet, put it on the end of a hot pestle, and rub it well with a handful of powder; after which add, by little and little, six pounds of powder; then sift the whole through a hair sieve to incorporate it with the other perfumed powder. The Ambergrise must be well rubbed in the mortar; and by degrees two pounds of powder, either white or grey, must be added to it, till the Ambergrise is thoroughly incorporated with the powder; then sift through a hair sieve, and mix all the three powders together. This perfume is to be kept in a Leather Bag, the seams of which are well sewed with waxed thread. 166. _Common perfumed Powder._ Take Florentine Orrice, a pound, dried Rose Leaves, a pound; Gum Benjamin, two ounces; Storax, an ounce; Yellow Sanders, an ounce and a half; Cloves, two drachms; and a little Lemon Peel; reduce the whole to a fine powder, and mix with it twenty pounds of Starch, or rather of grey or white powder; incorporate them well, and sift them through a lawn sieve. 167. _A Cassolette._ Incorporate the Powders of Florentine Orrice, Storax, Benjamin and other aromatics, with Orange-flower Water; and put this Paste into a little Silver or Copper Box lined with Tin. When you have a mind to use this perfume, set the Box on a gentle fire, or on hot ashes, and it will exhale a most delightful odour. 168. _To perfume a House, and purify the Air._ Take a root of Angelica, dry it in an oven, or before the fire, then bruise it well and infuse it four or five days in White Wine Vinegar. When you use it, lay it upon a brick made red hot, and repeat the operation several times. 169. _A Perfume to scent Powder._ Take a drachm of Musk, four ounces of Lavender Seeds, a drachm and a half of Civet, and half a drachm of Ambergrise. Beat the whole together into powder, and sift through a hair sieve. Keep this perfume in a box that shuts very close, to scent powder with, according to your fancy. PASTILS. 170. _An excellent Composition to perfume a Room agreeably._ Take four ounces of Gum Benjamin, two ounces of Storax, and a quarter of an ounce of Aloes-wood. When these ingredients have been well bruised, simmer them about half an hour over a slow fire, in a glazed earthen pipkin, with as much Rose-water as will cover them, and then strain off the liquor for use. Dry the Residuum or Marc, and pulverize it in a warm mortar with a pound of Charcoal. Dissolve some Gum Tragacanth in the reserved Liquor, then add to your powder a drachm of fine Oriental Musk dissolved in a little Rose-water, and form the whole into a Paste, of which make pastils about the length and thickness of the little finger, narrower at top than at bottom, that they may stand firm and upright. When they are thoroughly dry, light them at the narrow end, and let them burn till they are wholly consumed. While burning they afford an exquisite perfume. To render the perfume still higher, add six grains of Ambergrise. 171. _Or,_ Pulverize together two ounces of Gum Benjamin, half an ounce of Storax, a drachm of Aloes-wood, twenty grains of fine Civet, a little Sea Coal, and Loaf Sugar; boil the whole in a sufficient quantity of Rose-water, to the consistence of a stiff paste. If you are desirous of having your pastils higher flavoured, add twelve grains of Ambergrise just before you take the composition off the fire; and the ingredients being thoroughly mixed, form them into pastils. 172. _Fragrant Pastils made use of by way of Fumigation._ Take the purest Labdanum and Gum Benjamin, of each two ounces; Storax and dry Balsam of Peru, of each three quarters of an ounce; choice Myrrh, half a drachm; Gum Tacamahac, a quarter of an ounce; Olibanum, a drachm; Liquid Balsam of Peru, half an ounce; Ambergrise, a quarter of an ounce; Musk and Civet, of each a scruple; Essential Oil of Rhodium, thirty drops; Essential Oils of Orange-flowers, Lemons, and Bergamot, of each four drops; Gum Lacque, in fine powder, two ounces and a half; Cascarilla, Aloes-wood, Rose-wood, St. Lucia-wood, Yellow Sanders, and Cinnamon, all powdered, of each a drachm. With the assistance of a vapour-bath reduce them to a mass, which form into pastils in the usual way. 173. _Pastils of Roses._ Pulverize a pound of the Marc or Residuum left in the still after making Angelica Water; likewise a large handful of Roses; and with a sufficient quantity of Gum Tragacanth dissolved in Rose-water, beat them into a stiff paste, which is to be rolled out upon a marble with a rolling-pin, and cut into Lozenges, or formed into pastils. If you have a mind to ornament them, cover them with Leaf Gold or Silver. PASTES. 174. _Paste of dried Almonds to cleanse the Skin._ Beat any quantity you please, of Sweet and Bitter Almonds in a marble mortar, and while beating, pour on them a little Vinegar in a small stream to prevent their turning oily: then add two drachms of Storax in fine powder, two ounces of White Honey, and two Yolks of Eggs boiled hard; mix the whole into a paste. 175. _Soft Almond Paste._ Blanch in warm water any quantity of Bitter Almonds, leave them to grow dry, and then beat them in a marble mortar with a little Milk, to form them into a paste. To prevent their turning oily, afterwards add the Crumb of a light White Loaf soaked in Milk. Beat it with the Almonds till they are incorporated into an uniform mass; then put the whole into a kettle, with some fresh Milk, and let them simmer over a gentle fire; keeping the composition stirring, till it is boiled into a soft paste. 176. _Paste for the Hands._ Take Sweet Almonds, half a pound; White Wine Vinegar, Brandy, and Spring Water, of each two quarts; two ounces of Crumb of Bread, and the Yolks of two Eggs. Blanch and beat the Almonds, moistening them with the Vinegar; add the Crumb of Bread soaked in the Brandy, and mix it with the Almonds and Yolks of Egg, by repeated Trituration. Then pour in the Water, and simmer the whole over a slow fire, keeping the composition continually stirring, till it has acquired a proper consistence. 177. _Or,_ Take Bitter and Sweet Almonds blanched, of each two ounces; Pine-nuts, and the four Cold Seeds, of each an ounce; beat the whole together in a marble mortar with the Yolks of two Eggs, and the Crumb of a small Wheaten Loaf. Moisten the mass with White Wine Vinegar, put it into a deep pan, simmer it over a slow fire, and when the paste ceases sticking to the pan, it is sufficiently boiled. 178. _Or,_ Take blanched Almonds, a pound; Pine-nuts, four ounces; beat them together into a paste with the addition of two ounces of Loaf Sugar, an ounce of the finest Honey, the same quantity of Bean Flower, and half a gill of Brandy. This paste may be scented with the Essences of Cloves, Lemons, Bergamot, Jasmine, Rhodium, Orange Flowers, &c. or with a few grains of Musk, Civet, or a few drops of Essence of Ambergrise, for persons who have no aversion to those perfumes. 179. _Or,_ Beat half a pound of blanched Almonds, with half an ounce of Yellow Sanders, half an ounce of Florentine Orrice, and an ounce of Calamus Aromaticus, in fine powder; pour on them gradually an ounce of Rose-water, and then add half a Pippin sliced small, a quarter of a pound of stale Crumb of White Bread sifted fine, and knead the whole into a paste with two ounces of Gum Tragacanth dissolved in Rose-water. 180. _Or,_ Beat some peeled apples (having first taken out the Cores) in a marble mortar, with Rose-water, and White Wine, of each equal parts. Add some Crumb of Bread, blanched Almonds, and a little White Soap; and simmer the whole over a slow fire till it acquires a proper consistence. 181. _Or,_ Infuse some blanched Almonds, two or three hours, in Goat's or Cow's Milk, and beat them into a paste. Strain the infusion through a linen cloth with a strong pressure, and add to the strained Liquor half a pound of the Crumb of White Bread, a quarter of a pound of Borax, and as much Burnt Roch Alum. Simmer the whole together, and when almost boiled enough, add an ounce of Spermaceti. Stir the composition well with a spatula to prevent it from burning to the bottom of the pan; and let it simmer but very gently. 182. _Or,_ Dry, before the fire, half a pound of Bitter Almonds blanched, then beat them in a marble mortar as fine as possible, and add a little boiled Milk to prevent the Almonds from turning oily. Beat in the same manner the Crumb of two French Bricks, with four Yolks of Eggs boiled hard, and with the addition of some fresh Milk knead them into a paste, which incorporate with that of the Almonds. POMATUMS. 183. _Cold Cream, or Pomatum for the Complexion._ Take White Wax and Spermaceti, of each a drachm; Oil of Sweet Almonds, two ounces; Spring Water, an ounce and a half; melt the Wax and Spermaceti together in the Oil of Almonds, in a glazed earthen pipkin, over hot ashes, or in a vapour-bath; pour the solution into a marble mortar, and stir it about with a wooden pestle, till it grow cold, and seem quite smooth; then mix the Water gradually, and keep stirring, till the whole is incorporated. This pomatum becomes extremely white and light by the agitation, and very much resembles cream, from its similitude to which it has obtained its name. This pomatum is an excellent cosmetic, and renders the skin supple and smooth. Some add a little Balm of Gilead to heighten its virtue; and it is sometimes scented, by using Rose-water or Orange-flower Water in the preparation, instead of Spring-water, or with a few drops of any Essence, as fancy directs. It is also very good to prevent marks in the face from the Small-pox; in which last case, a little powder of Saffron, or some desiccative powder, such as Flowers of Zinc or French Chalk, is usually added. Keep it for use in a large gallypot tied over with a bladder. 184. _Cucumber Pomatum._ Take Hog's Lard, a pound; ripe Melons, and Cucumbers, of each three pounds, Verjuice, half a pint; two pippins pared, and a pint of Cow's Milk. Slice the Melons, Cucumbers, and Apples, having first pared them; bruise them in the Verjuice, and, together with the Milk and Hog's Lard, put them into an alembic. Let them infuse in a vapour-bath eight or ten hours; then squeeze out the Liquor through a straining cloth while the mixture is hot, and expose it to the cold air, or set it in a cool place to congeal. Afterwards pour off the watery part that subsides, and wash it in several Waters, till the last remains perfectly clear. Melt the pomatum again in a vapour-bath several times, to separate from it all its humid particles, and every extraneous substance; otherwise it will soon grow rancid. Keep it for use in a gallypot tied over with a bladder. 185. _Or,_ A more simple Cucumber Pomatum may be made by simmering together Hog's Lard and pared Cucumbers cut in thin slices. With respect to the rest of the process, follow the method laid down for preparing Lip-salve; and keep this pomatum in the same manner as the former. Both these pomatums are good Cosmetics; they soften the skin, and preserve it cool and smooth. 186. _Lavender Pomatum._ Take two pounds and a half of Hog's Lard, ten pounds of Lavender Flowers, and a quarter of a pound of Virgin's Wax; put two pounds of picked Lavender Flowers into a proper vessel with the Hog's Lard, and knead them with your hands into as uniform a paste as possible. Put this mixture into a pewter, tin, or stone pot, and cork it tight; place the vessel in a vapour-bath, and let it stand six hours; at the expiration of which time, strain the mixture through a coarse linen cloth, with the assistance of a press. Throw away the Lavender Flowers as useless, pour the melted Lard back into the same pot, and add four pounds of fresh Lavender Flowers. Stir the Lard and Flowers together while the Lard is in a liquid state, in order to mix them thoroughly; and repeat the former process. Continue to act in this manner till the whole quantity of Lavender Flowers is used. Then set in a cool place the pomatum separated from the Lavender Flowers, that it may congeal; pour off the brown aqueous juice extracted from them; and wash the Pomatum in several waters, stirring it with a wooden spatula, to separate any remaining watery particles, till the last water remains perfectly colourless. Then melt the Pomatum in a vapour-bath, and keep it in that state about an hour, in a vessel well corked; leaving it afterwards to congeal. Repeat this last operation till the aqueous particles are entirely extracted when the Wax must be added, and the Pomatum having been again melted, in a vapour-bath, in a vessel closely corked, be suffered to congeal as before. When properly prepared, fill it into gallypots, and tye the mouths over with wet bladders, to prevent the air from penetrating. This Pomatum is extremely fragrant, but is used only for dressing the hair. In the same manner are prepared, Orange-flower Pomatum, Jasmine Pomatum, and all Pomatums made of odoriferous flowers. Common Pomatum scented with the essences of any such flowers, may be used as a good succedaneum. 187. LIP-SALVES. Take three ounces of Oil of Almonds, three quarters of an ounce of Spermaceti, and a quarter of an ounce of Virgin's Wax; melt them together over a slow fire, mixing with them a little of the powder of Alkanet Root. Keep stirring till cold, and then add a few drops of Oil of Rhodium. 188. _Or,_ Take prepared Tutty and Oil of Eggs, of each equal parts; mix, and apply them to the lips, after washing the latter with Barley or Plantain Water. 189. _Or,_ Place over a chafing-dish of coals, in a glazed earthen pan, a quarter of a pound of the best fresh Butter, and an ounce of Virgin's Wax; melt them together; when thoroughly melted, throw in the Stones of half a bunch of ripe Black Grapes, with some Alkanet Roots a little bruised. Simmer these ingredient together for a quarter of an hour; afterwards strain the mixture through a fine linen cloth; and pour into your pomatum, which must be again set on the fire, a spoonful of Orange-flower Water. Having let them simmer together a little while, take the pan off the fire, and keep the pomatum stirring till it become quite cold. It will keep a long while, and is a perfect cure for chapped lips. 190. _A Yellow Lip-Salve._ Take Yellow Bee's Wax, two ounces and a half; Oil of Sweet Almonds, a quarter of a pint; melt the Wax in the Oil, and let the mixture stand till it become cold, when it acquires a pretty stiff consistence. Scrape it into a marble mortar, and rub it with a wooden pestle, to render it perfectly smooth. Keep it for use in a gallypot, closely covered. It is emollient and lenient; of course good for chaps in the lips, hands, or nipples; and preserves the skin soft and smooth. A Crust of Bread applied hot, is an efficacious remedy for pimples that rise on the lips, in consequence of having drank out of a glass after an uncleanly person. 191. _A Scarlet Lip-Salve._ Take Hog's Lard washed in Rose-water, half a pound; Red Roses and Damask Roses bruised, a quarter of a pound; knead them together and let them lie in that state two days. Then melt the Hog's Lard, and strain it from the Roses. Add a fresh quantity of the latter, knead them in the Hog's Lard, and let them lie together two days as before; then gently simmer the mixture in a vapour-bath. Press out the Lard, and keep it for use in the same manner as other Lip-salves. 192. _Or,_ Take an ounce of Oil of Sweet Almonds cold drawn, a drachm of fresh Mutton Suet, and a little bruised Alkanet Root; simmer the whole together. Instead of Oil of Sweet Almonds you may use Oil of Jasmine, or the Oil of any other Flower, if you choose the Lip-salve should have a fragrant scent. 193. _Or,_ Take Oil of Violets, and the expressed Juice of Mallows, of each an ounce and a half; Goose Grease and Veal Marrow, of each a quarter of an ounce; Gum Tragacanth, a drachm and a half; melt the whole over a gentle fire. 194. _Or,_ Take half a pound of fresh Butter, a quarter of a pound of Bee's Wax, four or five ounces of cleansed Black Grapes, and about an ounce of bruised Alkanet Root; simmer them together over a slow fire till the Wax is wholly dissolved, and the mixture become of a bright red colour; then strain, and set it by for use. 195. _Or,_ Take Deer or Goat's Suet, six ounces; Hog's Lard, four ounces: cut them into little bits, and wash them five or six different times in White Wine; then by hard pressure squeeze out every drop of the Wine. Melt the fats in a new-glazed earthen pan with half an ounce of Orrice Roots cut in thin slices, a grated Nutmeg, two or three Pippins pared and sliced thin, a pint of Rose-water, an ounce of Bee's Wax, and half an ounce of bruised Cloves. Simmer the whole over a slow fire about half an hour; then strain through a linen cloth into a pan half full of clean Water. Let the pomatum remain in the pan till cold, then wash it well, and beat it in a marble mortar with two ounces of White Wax, till they be thoroughly incorporated. Apply a little to the lips every night going to rest; and rub it upon the hands every night and morning. 196. _White Pomatum._ Take an ounce of Florentine Orrice-root, half an ounce of Calamus Aromaticus, and as much Gum Benjamin, a quarter of an ounce of Rose-wood, and a quarter of an ounce of Cloves. Bruise the whole into a gross powder, tie it up in a piece of linen, and simmer it in a vapour-bath, with two pounds and a half of Hog's Lard well washed; add a couple of Pippins pared and cut into small bits, four ounces of Rose-water, and two ounces of Orange-flower Water. After the ingredients have simmered together a little while, strain off the Liquor gently, and let the Pomatum stand till cold; then put it by for use in the same manner as other pomatums. 197. _Red Pomatum_ Is made by adding to the above more or less Alkanet Root bruised, according to the depth of colour you would wish to impart. Simmer the Pomatum and Alkanet together, stirring the mixture with a wooden spatula, till the Pomatum is sufficiently tinged; then strain it from the Roots, and set it by for use. 198. _A Pomatum to remove Redness, or Pimples in the Face._ Steep in clear Water a pound of a Boar's Cheek till it becomes tolerably white, drain it quite dry, and put it into a new-glazed earthen pan with two or three pared Pippins quartered, an ounce and a half of the four Cold Seeds bruised, and a slice of Veal about the size of the palm of one's hand. Boil the whole together in a vapour-bath for four hours, then with a strong cloth squeeze out your pomatum into an earthen dish placed upon hot ashes; adding to it an ounce of White Wax, and an ounce of Oil of Sweet Almonds. Stir the pomatum well with a spatula till it become cold. 199. _A Pomatum for Wrinkles._ Take Juice of White Lily Roots and fine Honey, of each two ounces; melted White Wax, an ounce; incorporate the whole together, and make a pomatum. It should be applied every night, and not be wiped off till the next morning. 200. _Another for the same Intention._ Take six new-laid Eggs, boil them hard, take out the Yolks, and fill the cavities with Myrrh, and powdered Sugar Candy, of each equal parts. Join the Whites together neatly, and set them on a plate before the fire; mixing the Liquor that exsudes from them with an ounce of Hog's Lard. This pomatum must be applied in the morning, and be suffered to dry upon the skin, which is afterwards to be wiped with a clean fine napkin. 201. _Or,_ Take half an ounce of Sallad Oil, an ounce of Oil of Tartar, half an ounce of Mucilage of Quince Seeds, three quarters of an ounce of Ceruss, thirty grains of Borax, and the same quantity of Sal Gem. Stir the whole together for some time in a little earthen dish, with a wooden spatula, and apply it in the same manner as the former composition. 202. _Pomatum for a red or pimpled Face._ Take two pared Apples, Celery, and Fennel, of each a handful; and Barley Meal, a quarter of an ounce. Simmer the whole together a quarter of an hour in a gill of Rose-water; then add an ounce of fine Barley Meal, the Whites of four new-laid Eggs, and an ounce of Deer's Suet. Strain through a canvas bag into a dish that contains a little Rose-water; wash the pomatum well in the Rose-water, and afterwards beat it in a mortar perfectly smooth. This pomatum is to be applied frequently through the day, to remove the redness of the face, pimples, and even freckles; but to answer the last mentioned purpose, it must be continued till they are entirely effaced. To prevent their return, the person must avoid the intense heat of the sun, and hot drying winds for some time. 203. _A Pomatum for the Skin._ Take Oil of White Poppy Seeds, and of the four Cold Seeds, of each a gill; Spermaceti, three quarters of an ounce; White Wax, an ounce: mix them into a pomatum according to the rules of art. A great quantity of a substance resembling Butter is extracted from the Cocoa Tree, which is excellent to mollify and nourish the skin, and has long been used for this purpose amongst the Spanish Creolian women. 204. _Pomatum to make the Hair grow in a bald Part, and thicken the Hair._ Take Hen's Fat, Oil of Hempseed, and Honey, of each a quarter of a pound; melt them together in an earthen pipkin, and keep the mixture stirring with a wooden spatula, till cold. This pomatum, to obtain the desired effect, must be rubbed on the part eight days successively. 205. _Another Pomatum for the Hair._ Cut into small pieces a sufficient quantity of Hog's Cheek, steep it eight or ten days in clean Water, which be careful to change three times a day, and every time the Water is changed, stir it well with a spatula to make the flesh white. Drain the flesh dry, and putting it into a new earthen pipkin, with a pint of Rose-water, and a Lemon stuck with Cloves, simmer them over the fire till the skum looks reddish. Skim this off, and removing the pipkin from the fire, strain the Liquor. When it has cooled, take off the fat; beat it well with cold Water, which change two or three times as occasion may require; the last time using Rose-water instead of common Water. Drain the Pomatum dry, and scent it with Violets, Tuberoses, Orange Flowers, Jasmine, Jonquils a la Reine, &c. in the following manner. 206. _Manner of Scenting Pomatums for the Hair._ Spread your Pomatum about an inch thick upon several dishes or plates, strewing the flowers you make choice of on one dish, and covering them with another. Change the Flowers for fresh ones every twelve hours, and continue to pursue this method for ten or twelve days; mixing the pomatum well, and spreading it out every time that fresh Flowers are added. It will soon acquire a fragrant scent, and may be used in what manner you think proper. It is good for almost every cosmetic purpose, but more particularly for the hair, which it nourishes, strengthens, preserves, and thickens. 207. _Orange-Flower Pomatum._ Take two pounds and a half of Hog's Lard, and three pounds of Orange Flowers; mix them together in a marble mortar; then put the mixture into an earthen vessel with some Water, and place it in a vapour-bath, where let it stand till the Lard is melted, and floats above the Flowers. When it has stood till cold, pour away the Water, and simmer in the usual manner, with three pounds of fresh Orange Flowers. Repeat the same operation twice more with two pounds of Orange Flowers each time; and the last time, while the mixture stands in infusion, add a gill of Orange-flower Water. Strain through a hair sieve held over an earthen dish; drain off the Water thoroughly when cold, and keep the Pomatum in a dry place, in a gallypot close tied over with a bladder. In the same manner are prepared Jasmine, Jonquil, Tuberose, Lavender Pomatums, and all pomatums scented with Flowers. 208. _Sultana Pomatum._ This pomatum is made of Balsam of Mecca, Spermaceti, and Oil of Sweet Almonds cold drawn. It clears and preserves the complexion, and is of use for red pimpled faces. 209. _A sweet smelling Perfume._ Take a pound of fresh-gathered Orange Flowers, of common Roses, Lavender Seeds, and Musk Roses, each half a pound; of Sweet Marjoram Leaves, and Clove-july-flowers picked, each a quarter of a pound; of Thyme, three ounces; of Myrtle Leaves, and Melilot Stalks stripped of their Leaves, each two ounces; of Rosemary Leaves, and Cloves bruised, each an ounce; of Bay Leaves, half an ounce. Let these ingredients be mixed in a large pan covered with parchment, and be exposed to the heat of the sun during the whole summer; for the first month stirring them every other day with a stick, and taking them within doors in rainy weather. Towards the end of the season, they will afford an excellent composition for a perfume; which may be rendered yet more fragrant, by adding a little scented Cypress-powder, mixed with coarse Violet-powder. 210. _Another for the same Purpose._ Take Orange Flowers, a pound; common Roses picked without the Yellow Pedicles, a pound; Clove-july-flowers picked with the White End of their Leaves cut off, half a pound; Marjoram, and Myrtle Leaves picked, of each half a pound; Musk Roses, Thyme, Lavender, Rosemary, Sage, Chamomile, Melilot, Hyssop, Sweet Basil, and Balm, of each two ounces; fifteen or twenty Bay Leaves, two or three handfuls of Jasmine, as many little Green Oranges, and half a pound of Salt. Put them in a proper vessel, and leave them together a whole month, carefully observing to stir the mixture well twice a day with a wooden spatula or spoon. At the month's end, add twelve ounces of Florentine Orrice-root in fine powder, and the same quantity of powdered Benjamin; of Cloves, and Cinnamon finely powdered, each two ounces; Mace, Storax, Calamus Aromaticus, all in fine powder, and Cypress-powder, of each an ounce; Yellow Sanders and Cyprus or Sweet Flag, of each three quarters of an ounce. Mix the whole thoroughly, by stirring, and you will have a very fragrant perfume. POWDERS. 211. _Orange-Flower Powder._ Put half a pound of Orange Flowers into a box that contains twelve pounds and a half of powdered Starch; mix them well with the Starch, and stir the mixture at intervals, to prevent the Flowers from heating. At the expiration of twenty-four hours, remove the old flowers, and mix with the Starch the same quantity of fresh Orange Flowers. Continue acting in this manner for three days together, and if you think the perfume not sufficiently strong, add fresh Flowers once or twice more. The box must be kept close shut, as well after as during the operation. 212. _Jonquil Powder._ Take of Starch Powder and Jonquil Flowers, in the same proportion as in the preceding article; strew the Flowers among the Powder, and at the expiration of twenty hours, sift it through a coarse sieve. Then throw away the Flowers, and add to the Powder the same quantity of fresh Flowers. Continue this method four or five days, observing never to touch the Powder while the Flowers lie mixed with it; and the former will hence acquire a very agreeable perfume. In the same manner are prepared, Hyacinth, Musk Rose, and Damask Rose Powders, &c. 213. _Coarse Violet Powder._ Beat separately into coarse Powder the following ingredients, viz. half a pound of dried Orange Flowers; of Lemon-peel dried, Yellow Sanders, Musk Roses, and Gum Benjamin, each a quarter of a pound; Lavender Tops dried, three ounces; of Rose Wood, Calamus Aromaticus, and Storax, each two ounces; an ounce of Sweet Marjoram, half an ounce of Cloves, two pounds of Florentine Orrice-root, and a pound of dried Provence Roses; mix the whole together. When you want to fill bags with this powder, mix a drachm of Musk and half a drachm of Civet, with a little Mucilage of Gum Tragacanth made with Angelic Water, and a little Sweet-scented Water, and rub the inside of the bag over with the composition, before you fill it with the Violet Powder. 214. _Another coarse Violet Powder._ Mix together a pound of Florentine Orrice-roots, half a pound of dried Orange Flowers, a quarter of a pound of Yellow Sanders; of Coriander Seeds, Sweet Flag, and of the Marc or Residuum left after making Angelic Water, each two ounces; an ounce and a half of Calamus Aromaticus, and an ounce of Cloves; bruise the whole into a coarse Powder, and keep it for use in a jar, close stopped. 215. _Jasmine Powder._ Powder French Chalk, sift it through a fine sieve, put it in a box, and strew on it a quantity of Jasmine Flowers; shut down the lid close, and add fresh Flowers every four and twenty hours. When the Powder is well impregnated with the scent of Jasmine, rub together a few grains of Civet, Ambergrise, and a little white Sugar Candy, and mix them with the Powder. 216. _Ambrette Powder._ Take six ounces of Bean Flour, and the same quantity of worm-eaten Wood, four ounces of Cyprus Wood, two ounces of Yellow Sanders, two ounces of Gum Benjamin, an ounce and a half of Storax, a quarter of an ounce of Calamus. Aromaticus, and as much Labdanum; beat the whole into a very fine powder, and sift it through a lawn sieve. Add four grains of Ambergrise, and half an ounce of Mahaleb or Musk Seeds; mix them with the rest of the powder, and keep the whole in a bottle close stopped for use. You may put any quantity you please of this Perfume into common powder, to give it an agreeable flavour. 217. _Cyprus Powder._ Fill a linen bag with Oak Moss, steep it in water, which change frequently, and afterwards dry the Moss in the sun. Beat it to powder, and sprinkle it with Rose-water; then dry it again, sift it through a fine sieve, and mix with it a small quantity of any of the preceding powders. 218. _Another Cyprus Powder more fragrant._ Wash Oak Moss several times in pure water and dry it thoroughly; then sprinkle over it Orange Flower and Rose-water, and spread it thin upon a hurdle to dry. Afterwards place under it a chafing-dish, in which burn some Storax and Benjamin. Repeat this operation till the Moss becomes well perfumed; then beat it to fine powder, and to every pound add a quarter of an ounce of Musk, and as much Civet. 219. _Perfumed Powder._ Take a pound of Florentine Orrice-root, two ounces of Gum Benjamin, a pound of dried Roses, an ounce of Storax, an ounce and a half of Yellow Sanders, a quarter of an ounce of Cloves, and a small quantity of Lemon-peel; beat the whole together into fine powder, and then add twenty pounds of Starch-powder. Sift through a lawn sieve; and colour the powder according to your fancy. 220. _The White Powder that enters into the Composition of the Delightful Perfume._ Take a pound of Florentine Orrice-root, twelve Cuttle-fish Bones, eight pounds of Starch, and a handful of Sheep or Bullock's Bones calcined to whiteness; beat the whole into a powder, and sift it through a fine hair sieve. 221. _Prepared Powder._ Pour a quart of Brandy, or an ounce of highly rectified Spirit of Wine, on a pound or a pound and a half of Starch, mix them together; then dry the Starch, beat it to powder, and sift it through a fine lawn sieve. If you please you may add a little powder of Florentine Orrice-root. 222. _A Powder to nourish the Hair._ Take Roots of the Sweet Flag, Calamus Aromaticus, and Red Roses dried, of each an ounce and a half; Gum Benjamin, an ounce; Aloes Wood, three quarters of an ounce; Red Coral prepared, and Amber prepared, of each half an ounce; Bean Flour, a quarter of a pound, Florentine Orrice-roots, half a pound; mix the whole together, then beat into a fine powder, and add to it five grains of Musk, and the same quantity of Civet. This powder greatly promotes the regeneration of the hair, and strengthens and nourishes its roots. The property of enlivening the imagination, and helping the memory is also attributed to it. 223. _Common Powder._ The best Starch dried is generally the basis of all Hair-powders: as are, sometimes, worm-eaten or rotten Wood, dried Bones, or Bones calcined to whiteness, which are sifted through a fine hair sieve after they have been beaten to powder. This kind of Powder readily takes any scent, particularly that of Florentine Orrice, a root which naturally possesses a violet smell. Of these Roots, the whitest and soundest are made choice of; they are to be powdered as fine as possible, and this can only be done during the summer. 224. _White Powder._ Take four pounds of Starch, half a pound of Florentine Orrice-root, six Cuttle-fish Bones; Ox Bones and Sheeps Bones calcined to whiteness, of each half a handful; beat the whole together, and sift the Powder through a very fine sieve. 225. _Grey Powder._ To the Residuum of the preceding add a little Starch and Wood-ashes in fine powder; rub them together in a mortar some time, and then sift through a fine hair sieve. 226. _Another._ Take the Marc or Residuum of the White Powder, mix with it a little Starch, Yellow Ochre, and Wood-ashes or Baker's Coals to colour it. Beat the whole well in a mortar, then sift it through a hair sieve. Beat the coarser parts over again, and sift a second time; repeating these operations till all the composition has passed through the sieve. 227. _Flaxen coloured Powder._ Add to the White Powder a very little Yellow Ochre. The White Powder may be tinged of any colour, by adding ingredients of the colour you fancy. 228. _Bean Flour._ Grind any quantity of Beans, and sift the Meal through a very fine lawn sieve. It will take no other scent than that of Florentine Orrice. 229. _To sweeten the Breath._ Roll up a little ball of Gum Tragacanth, scent it with some odoriferous Essence or Oil, and hold it in the mouth. A little Musk may be added to the ball while rolling up, where that perfume is not disagreeable. 230. _Or,_ After having eat Garlic or Onions, chew a little raw Parsley. It will infallibly take away their offensive smell. 231. _A Remedy for scorbutic Gums._ Bruise Cinquefoil in a marble mortar, squeeze out the juice, warm it over the fire, and rub the Gums with it every night and morning. 232. _A Remedy for Moist Feet._ Take twenty pounds of Lee made of the Ashes of the Bay Tree, three handfuls of Bay Leaves, a handful of Sweet Flag, with the same quantity of Calamus Aromaticus, and Dittany of Crete; boil the whole together for some time, then strain off the liquor, and add two quarts of Wine. Steep your feet in this bath an hour every day, and in a short time they will no longer exhale a disagreeable smell. FLEAS. 233. _A certain Method of destroying Fleas._ Sprinkle the room with a decoction of Arsmart, Bitter Apple, Briar Leaves, or Cabbage Leaves; or smoke it with burnt Thyme or Pennyroyal. 234. _Or,_ Put Tansy Leaves about different parts of the bed, viz. under the matrass, or between the blankets. 235. _Or,_ Rub the bed-posts well with a strong decoction of Elder Leaves. 236. _Or,_ Mercurial Ointment, or a fumigation of Pennyroyal Leaves, or of Brimstone, infallibly destroys Fleas; as likewise do the fresh Leaves of Pennyroyal, tied up in a bag, and laid upon the bed. WRINKLES. 237. _A Secret to take away Wrinkles._ Heat an Iron Shovel red hot, throw on it some Powder of Myrrh, and receive the smoke on your face, covering the head with a napkin to prevent its being dissipated. Repeat this operation three times, then heat the Shovel again, and when fiery hot pour on it a mouthful of White Wine. Receive the vapour of the Wine also on your face, and repeat it three times. Continue this method every night and morning as long as you find occasion. CARMINES. 238. _A Rouge for the Face._ Alkanet Root strikes a beautiful red when mixed with Oils or Pomatums. A Scarlet or Rose-coloured Ribband wetted with Water or Brandy, gives the Cheeks, if rubbed with it, a beautiful bloom that can hardly be distinguished from the natural colour. Others only use a Red Sponge, which tinges the cheeks of a fine carnation colour. 239. _Another._ Alum, beat them together into a coarse powder, and boil in a sufficient quantity of Red Wine, till two thirds of the Liquor are consumed. When this decoction has stood till cold, rub a little on the cheeks with a bit of cotton. 240. _The Turkish Method of preparing Carmine._ Infuse, during three or four days, in a large jar filled with White Wine Vinegar, a pound of Brazil Wood Shavings of Fernambuca, having first beaten them to a coarse powder; afterwards boil them together half an hour; then strain off the Liquor through a coarse linen cloth, set it again upon the fire, and having dissolved half a pound of Alum in White Wine Vinegar, mix both Liquors together, and stir the mixture well with a spatula. The scum that rises is the Carmine; skim it off carefully, and dry it for use. Carmine may also be made with Cochineal, or Red Sanders, instead Brazil Wood. 241. _A Liquid Rouge that exactly imitates Nature._ Take a pint of good Brandy, and infuse in it half an ounce of Gum Benjamin, an ounce of Red Sanders, and half an ounce of Brazil Wood, both in coarse powder; with half an ounce of Roch Alum. Cork the bottle tight, shake it well every day, and at the expiration of twelve days the Liquor will be fit for use. Touch the cheeks lightly with this Tincture, and it will scarcely be possible to perceive that rouge has been laid on, it will so nearly resemble the natural bloom. 242. _An Oil that possesses the same Property._ Take ten pounds of Sweet Almonds, an ounce of Red Sanders in powder, and an ounce of bruised Cloves; pour on them a gill of White Wine, and three quarters of a gill of Rose-water; stir them well every day. At the end of eight or nine days, squeeze the paste in a press in the same manner as when you mean to extract Oil of Almonds. SWEET-SCENTED BAGS. 243. _A Sweet-Scented Bag to wear in the Pocket._ Take thin Persian, and make it into little bags about four inches wide, in the form of an oblong square. Rub the inside lightly with a little Civet, then fill them with coarse powder a la Marechale, or any other odoriferous Powder you choose; to which add a few Cloves, with a little Yellow Sanders beaten small, and sew up the mouths of the bags. 244. _Bags to Scent Linen._ Take Rose Leaves dried in the shade, Cloves beat to a gross powder, and Mace, scraped; mix them together, and put the composition into little bags. 245. _An agreeable Sweet-Scented Composition._ Take Florentine Orrice, a pound and a half; Rose Wood, six ounces; Calamus Aromaticus, half a pound; Yellow Sanders, a quarter of a pound; Gum Benjamin, five ounces; Cloves, half an ounce; and Cinnamon, an ounce: beat the whole into powder, and fill your bags with it. 246. _Ingredients for various Sorts of these little Bags or Satchels._ For this purpose may be used different parts of the Aromatic Plants; as Leaves of Southernwood, Dragon-wort, Balm, Mint both garden and wild, Dittany, Ground-ivy, Bay, Hyssop, Lovage, Sweet Marjoram, Origanum, Pennyroyal, Thyme, Rosemary, Savory, Scordium, and Wild Thyme. The Flowers of the Orange, Lemon, Lime, and Citron Tree, Saffron, Lavender, Roses, Lily of the Valley, Clove-july-flower, Wall-flower, Jonquil, and Mace. Fruits, as Aniseeds, &c. The Rinds of Lemons, Oranges, &c. Small green Oranges, Juniper-berries, Nutmegs, and Cloves. Roots of Acorus, Bohemian Angelica, Oriental Costus, Sweet Flag, Orrice, Zedoary, &c. The Woods of Rhodium, Juniper, Cassia, St. Lucia, Sanders, &c. Gums, as Frankincense, Myrrh, Storax, Benjamin, Labdanum, Ambergrise, and Amber. Barks, as Canella Alba, Cinnamon, &c. Care must be taken that all these ingredients are perfectly dry, and kept in a dry place. To prevent their turning black, add a little common Salt. When you choose to have any particular Flower predominant, a greater quantity of that plant must be used in proportion to the other ingredients. WASH-BALLS. 247. _White Soap._ This soap is made with one part of the Lees of Spanish Pot-ash and Quick-lime, to two parts of Oil of Olives or Oil of Almonds. 248. _Honey Soap._ Take four ounces of White Soap, and as much Honey, half an ounce of Salt of Tartar, and two or three drachms of the distilled Water of Fumitory; mix the whole together. This Soap cleanses the skin well, and renders it delicately white and smooth. It is also used advantageously, to efface the marks of burns and scalds. 249. _A perfumed Soap._ Take four ounces of Marsh-mallow Roots skinned and dried in the shade, powder them, and add an ounce of Starch, the same quantity of Wheaten Flour, six drachms of fresh Pine-nut Kernels, two ounces of blanched Almonds, an ounce and a half of Orange Kernels husked, two ounces of Oil of Tartar, the same quantity of Oil of Sweet Almonds, and thirty grains of Musk: thoroughly incorporate the whole, and add to every ounce, half an ounce of Florentine Orrice-root in fine powder. Then steep half a pound of fresh Marsh-mallow Roots bruised in the distilled Water of Mallows, or Orange Flowers, for twelve hours, and forcibly squeezing out the liquor, make, with this mucilage, and the preceding Powders and Oils, a stiff Paste, which is to be dried in the shade, and formed into round balls. Nothing exceeds this Soap for smoothing the skin, or rendering the hands delicately white. 250. _Fine scented Wash-ball._ Take of the best White Soap, half a pound, and shave it into thin slices with a knife; then take two ounces and a half of Florentine Orrice, three quarters of an ounce of Calamus Aromaticus, and the same quantity of Elder Flowers; of Cloves, and dried Rose Leaves, each half an ounce; Coriander-seeds, Lavender, and Bay Leaves, of each a drachm, with three drachms of Storax. Reduce the whole to fine powder, which knead into a Paste with the Soap; adding a few grains of Musk or Ambergrise. When you make this Paste into Wash-balls, soften it with a little Oil of Almonds to render the composition more lenient. Too much cannot be said in favour of this Wash-ball, with regard to its cleansing and cosmetic property. 251. _A Wash-ball, an excellent Cosmetic for the Face and Hands._ Take a pound of Florentine Orrice, a quarter of a pound of Storax, two ounces of Yellow Sanders, half an ounce of Cloves, as much fine Cinnamon, a Nutmeg, and twelve grains of Ambergrise; beat the whole into very fine powder and sift them through a lawn sieve, all except the Ambergrise, which is to be added afterwards. Then take two pounds of the finest White Soap, shaved small, and infuse it in three pints of Brandy, four or five days. When it is dissolved, add a little Orange Flower-water, and knead the whole into a very stiff Paste with the best Starch finely powdered. Then mix the Ambergrise, with a little Gum Tragacanth liquefied in sweet-scented Water. Of this Paste make Wash-balls; dry them in the shade, and polish them with a Paste-board or Lignum Vitæ cup. 252. _Bologna Wash-balls._ Take a pound of Italian Soap cut in small bits, and a quarter of a pound of Lime; pour on them two quarts of Brandy, let them ferment together twenty-four hours, then spread the mass on a sheet of filtring paper to dry. When quite dry, beat it in a marble mortar, with half an ounce of St. Lucia Wood, an ounce and a half of Yellow Sanders, half an ounce of Orrice-root, and as much Calamus Aromaticus, all finely powdered. Knead the whole into a Paste with Whites of Eggs, and a quarter of a pound of Gum Tragacanth dissolved in Rose-water, and then form it into Wash-balls according to the usual method. 253. _An excellent Wash-ball for the Complexion._ Take two ounces of Venetian Soap; dissolve it in two ounces of Lemon Juice, an ounce of Oil of Bitter Almonds, and the same quantity of Oil of Tartar. Mix the whole together, and stir the mixture till it acquires the consistence of a thick Paste. 254. _Seraglio Wash-balls._ Take a pound of Florentine Orrice-roots, a quarter of a pound of Gum Benjamin, two ounces of Storax, two ounces of Yellow Sanders, half an ounce of Cloves, a drachm of Cinnamon, a little Lemon-peel, an ounce of St. Lucia Wood, and one Nutmeg. Reduce the whole to fine powder; then take about two pounds or White Soap shaved thin, steep it with the above Powder in three pints of Brandy, four or five days. Afterwards kneading the mass with a sufficient quantity of Starch, and adding to it the Whites of Eggs, with Gum Tragacanth dissolved in some odoriferous Water, form the Paste into Wash-balls of what size you please. A few grains of Musk or Civet, or a little Essential Oil of Lavender, Bergamot, Roses, Cloves, Clove-july-flowers, Jasmine, Cinnamon, in short, any that best pleases the fancy of the person who prepares these Wash-balls, may be incorporated with the Paste while forming into a mass. 255. _A Hepatic Salt, to preserve the Complexion._ Take Roots of Agrimony, two pounds; Roots of Succory and Scorzonera, of each a pound; Bitter Costus and Turmeric, of each half a pound; Calamus Aromaticus and Rhapontic, of each a quarter of a pound; Wormwood, Southernwood, Sweet Maudlin, Harts-tongue, Fluellin, Liverwort, Fumitory, and Dodder of Thyme, of each three ounces; calcine the whole in a reverberatory furnace, and add Ashes of Rhubarb and Cassia Lignea of each an ounce and a half. Make a lee with these Ashes in a decoction of the Flowers of Liverwort, and extract the Salt according to art. This Salt causes the bile to flow freely, removes obstructions, cures the jaundice, takes away a sallow complexion, and imparts to the skin the ruddy vermillion bloom of health. Its dose is from twenty-four to thirty-six grains, in any convenient vehicle. EYE-BROWS. 256. _To change the Eye-brows black._ Rub them frequently with ripe Elder-berries. Some use burnt Cork, or Cloves burnt in the candle; others prefer the Black of Frankincense, Rosin, and Mastic. This Black will not melt nor come off by sweating. MARKS OF THE SKIN. 257. _To efface Spots or Marks of the Mother, on any Part of the Body._ Steep in Vinegar of Roses, or strong White Wine Vinegar, Borrage Roots stripped of their small adhering fibres, and let them stand to infuse twelve or fourteen hours. Bathe the part affected frequently with this Infusion, and in time the marks will totally disappear. 258. _Or,_ Take, towards the end of the month of May, the Roots and Leaves of the herb Bennet; distil them with a sufficient quantity of Water in an alembic, and frequently foment the marks with the distilled Water. 259. _To take away Marks, and fill up the Cavities left after the Small-Pox._ Take Oil of the four larger Cold Seeds, Oil of Eggs, and Oil of Sweet Almonds, of each half an ounce; Plantain and Nightshade Water, of each three quarters of an ounce; Litharge and Ceruss finely powdered and washed in Rose-water, of each a drachm. Put the Litharge and Ceruss into a brass pot, and incorporate them over a fire, with the Oils, adding the latter gradually, and stirring the mixture all the while. Then add by degrees also the Nightshade and Plantain Water, and thus form a Liniment, with which anoint the face of the patient as soon as the scabs of the Small-pox begin to scale off; and repeat the application as occasion may require. COMPLEXION. 260. _Certain Methods to improve the Complexion._ Brown ladies should frequently bathe themselves, and wash their faces with a few drops of Spirit of Wine, sometimes with Virgin's Milk, and the distilled Waters of Pimpernel, White Tansy, Bean Flowers, &c. These detersive penetrating applications, by degrees remove the kind of varnish that covers the skin, and thus render more free the perspiration, which is the only real cosmetic. 261. _The Montpellier Toilet._ For this purpose a new light-woven linen cloth must be procured, and cut of a proper size to make a toilet. The first step you take must be to wash the cloth perfectly clean in several different Waters, then spread it out to dry, and afterwards steep it twenty-four hours in Sweet-scented Water, viz. half Angelic, and half Rose-water. On removing the cloth out of the water, gently squeeze it, and hang it up to dry in the open air. Then lay on it the following composition. Take dried Orange Flowers, Roots of Elecampane, and Florentine Orrice, of each half a pound; of Yellow Sanders, four ounces; of the Marc or Residuum of Angelic Water, two ounces; of Rose-wood and Sweet Flag, each an ounce; of Gum Labdanum, Calamus Aromaticus, and Cloves, each half an ounce; of Cinnamon, two drachms; beat all these ingredients into powder, and make them into a Paste with Mucilage of Gum Tragacanth dissolved in Angelic Water. Rub this Paste hard on both sides of your cloth, leaving on it the little bits that may adhere, because they render the surface more smooth. Afterwards hang up the cloth, and when half dry, again rub both sides, with a sponge wetted with Angelic Water, to render the cloth yet more smooth; after which dry it thoroughly, and fold it up. This cloth is generally lined with taffety, and covered with sattin, and is never enclosed within more than two pieces of some kind of thin silk, as Taffety, &c. 262. _Sweet-scented Troches to correct a bad Breath._ Take Frankincense, a scruple; Ambergrise, fifteen grains; Musk, seven grains: Oil of Lemons, six drops; double refined Sugar, an ounce. Form these ingredients into little Troches with Mucilage of Gum Arabic, made with Cinnamon Water. Hold one or two in the mouth as often occasion requires. 263. _A curious Varnish for the Face._ Fill into a bottle three quarters of a pint of good Brandy, infusing in it an ounce of Gum Sandarach, and half an ounce of Gum Benjamin. Frequently shake the bottle till the Gums are wholly dissolved, and then let it stand to settle. Apply this varnish after having washed the face clean, and it will give the skin the finest lustre imaginable. WARTS. 264. _A Medicine to cure Warts._ Take the Leaves of Campanula, bruise them, and rub them upon the warts. Repeat this operation three or four times, if they prove obstinate; and they will afterwards soon waste away without leaving the least mark behind. This plant perhaps is not to be met with every where, but Botanists have described it by the following marks. Its leaves, say they, resemble those of the Blue Bell Flower, or Ivy, are stringy, composed of five lobes, without down, are small at the end, and have a loose flabby stalk. 265. _Another._ Take the inner Rind of a Lemon, steep it four and twenty hours in distilled Vinegar, and apply it to the warts. It must not be left on the part above three hours at a time, and is to be applied afresh every day. 266. _Or,_ Divide a Red Onion, and rub the warts well with it. 267. _Or,_ Anoint the warts with the milky Juice of the herb Mercury several times, and they will gradually waste away. 268. _Another safe and experienced Method._ Rub the warts with a pared Pippin, and a few days afterwards they will be found to disappear. VINEGARS. 269. _Distilled Vinegar._ Fill a stone cucurbit about three parts and a half full of White Wine Vinegar; place the vessel in a furnace so contrived as to contain three parts of the height of the cucurbit; mould the openings that remain between the sides and the upper part of the vessel with clay tempered with water; lute the vessel, fix on a receiver, and begin your distillation with a moderate fire, which is to be increased by degrees till about five sixths of the Vinegar are drawn off, which is called Distilled Vinegar. A small quantity of acid Liquor still remains in the cucurbit of the consistence of Honey, which if you think proper may be dried hard by the assistance of a vapour-bath. The Vinegar distilled from this substance is infinitely more acid, than that which was drawn off by the first process. To rectify distilled Vinegar, put it into a clean vessel, setting it in the same degree of fire as at first to separate more phlegm, and in every thing proceed as before, till the bottom is almost dry. Neither the fire nor distillation however must be urged too far, for fear of giving an empyreumatic flavour to that which is already distilled. Distilled Vinegar is used externally, mixed with Water, to wash the face: it is cooling, and takes away the troublesome little pimples that sometimes affect this part. 270. _Distilled Lavender Vinegar._ Put into a stone cucurbit any quantity of fresh-gathered Lavender Flowers picked clean from the Stalks; pour on them as much distilled Vinegar as is requisite to make the Flowers float; distil in a vapour-bath, and draw off about three fourths of the Vinegar. In the same manner are prepared the Vinegars from all other vegetable substances. Compound Vinegars are made by mixing several aromatic substances together; observing only to bruise all hard woody ingredients, and to let them infuse a sufficient time in the Vinegar before you proceed to distillation. Lavender Vinegar is of use for the Toilet; it is cooling, and when applied to the face, braces up the relaxed fibres of the skin. 271. _Vinegar of the Four Thieves._ Take of the tops of Sea and Roman Wormwood, Rosemary, Sage, Mint and Rue, of each an ounce and a half; Lavender Flowers two ounces, Calamus Aromaticus, Cinnamon, Cloves, Nutmeg, and Garlic, of each a quarter of an ounce; Camphire, half an ounce; Red Wine Vinegar, a gallon. Choose all the foregoing ingredients dry, except the Garlic and Camphire; beat them into gross powder, and cut the Garlic into thin slices; put the whole into a matrass; pour the Vinegar on them, and digest the mixture in the sun, or in a gentle sand-heat, for three weeks or a month. Then strain off the Vinegar by expression, filter it through paper, and add the Camphire dissolved in a little rectified Spirit of Wine. Keep it for use in a bottle, tightly corked. The Vinegar of the Four Thieves is antipestilential, and is used successfully as a preservative against contagious disorders. The hands and face are washed with it every day; the room fumigated with it, as are also the clothes, in order to secure the person from infection. EYES. 272. _To cure watery Eyes._ Prepare a decoction with the Leaves of Betony, Fennel Roots, and a little fine Frankincense, which use as an Eye-water. 273. _Or,_ Frequently bathe the Eyes with a decoction of Chervil. 274. _Or,_ Drop into the Eyes now and then a little Juice of Rue, mixed with clarified Honey. 275. _An excellent Ophthalmic Lotion._ Take White Vitriol and Bay Salt, of each an ounce; decrepitate them together, and when the detonation is over, pour on them, in an earthen pan, a pint of boiling Water or Rose-water. Stir them together, and let them stand some hours. A variously coloured skin will be formed on the surface, which carefully skim off, and put the clear liquor into a bottle for use. This was communicated to the author as a great secret; and indeed he has found it by experience very safely to cool and repel those sharp humours that sometimes fall upon the Eyes, and to clear the latter of beginning films and specks. If too sharp, it may be diluted with a little Rose-water. 276. _An Ophthalmic Poultice._ Take half a pint of Alum Curd, and mix with it a sufficient quantity of Red Rose Leaves powdered, to give it a proper consistence. This is an excellent application for sore moist eyes, and admirably cools and represses defluxions. 277. _A Poultice for inflamed Eyes._ Take half a pint of a decoction of Linseed in Water, and as much Flour of Linseed as is sufficient to make it of a proper consistence. This Poultice is preferable to a Bread and Milk Poultice for inflamed Eyes, as it will not grow sour and acrid. 278. _Sir Hans Sloane's Eye Salve._ Take prepared Tutty, one ounce; prepared Bloodstone, two scruples; Aloes in fine powder, twelve grains; mix them well together in a marble mortar, with as much Viper's Fat as is requisite to bring the whole to the consistence of a soft salve. It is to be applied with a hair pencil, the eyes winking or a little opened. It has cured many whose eyes were covered with opake films and scabs, left by preceding disorders of those parts. 279. _An Ophthalmic Fomentation._ Take three quarters of an ounce of White Poppy Heads bruised with their Seeds, and boil them in Milk and Water, of each half a pint, till one half is wasted away; then dissolve in the strained Liquor a scruple of Sugar of Lead. This is an excellent application for moist, or inflamed Eyes. 280. _A Simple Remedy to strengthen the Sight._ Snuff up the Juice of Eyebright, and drop a little into the eyes. It not only clears and strengthen the sight, but takes off all specks, films, mists, or suffusions. Herb Snuffs are also excellent to strengthen and preserve the sight; various Receipts for making which will afterwards be given. SUPPLEMENT. Manner of taking out all Kinds of SPOTS and STAINS from LINEN and STUFFS; and various other useful Receipts. 281. _To take Iron Mould out of Linen._ Hold the Iron Mould over the Fume of Boiling Water for some time, then pour on the spot a little Juice of Sorrel and a little Salt, and when the cloth has thoroughly imbibed the Juice, wash it in Lee. 282. _To take out Stains of Oil._ Take Windsor Soap shaved thin, put it into a bottle half full of Lee, throw in the size of a Nut of Sal Armoniac, a little Cabbage Juice, two Yolks of new-laid Eggs, and Ox-gall at discretion, and lastly an ounce of powdered Tartar: then cork the bottle, and expose it to the heat of the noon-day sun four days, at the expiration of which time it becomes fit for use. Pour this Liquor on the stains, and rub it well on both sides of the cloth; then wash the stains with clear Water, or rather with the following soap, and when the cloth is dry, they will no longer appear. 283. _Scowering Balls._ Take soft Soap, or Fuller's Earth; mix it with Vine Ashes sifted through a fine sieve, and with powdered Chalk, Alum, and Tartar, of each equal parts; form the mass into balls, which dry in the shade. Their use is to rub on spots and stains, washing the spotted part afterwards in clear Water. 284. _To take out Stains of Coomb._ Put Butter on the stain, and rub it well with a piece of brown paper laid on a heated silver spoon; then wash the whole in the same manner as directed for spots of Wax. 285. _To take out Stains of Urine._ Wash the stained place well with boiled Urine, and afterwards wash it in clear Water. 286. _To take out Stains on Cloth of whatever Colour._ Take half a pound of Honey, the size of a Nut of Sal Armoniac, and the Yolk of an Egg; mix them together, and put a little of this mixture on the stain, letting it remain till dry. Then wash the cloth with fair Water, and the stains will disappear. Water impregnated with mineral Alkaline Salt or Soda, Ox-gall, and Black Soap, is also very good to take out spots of grease. 287. _To take out Spots of Ink._ As soon as the accident happens, wet the place with Juice of Sorrel, or Lemon, or with Vinegar, and the best hard White Soap. 288. _To take out Spots of Pitch and Turpentine._ Pour a good deal of Sallad Oil on the stained place, and let it dry on it four and twenty hours; then rub the inside of the cloth with the Scowering Ball and warm Water. 289. _To take out Spots of Oil on Sattin and other Stuffs, and on Paper._ If the spot be not of long standing, take the Ashes of Sheep's Trotters calcined, and apply them hot both under and upon the spot. Lay on it something heavy, letting it remain all night; and if in the morning the spot is not entirely effaced, renew the application repeatedly till it wholly disappear. 290. _To take out Spots on Silk._ Rub the Spots with Spirit of Turpentine; this Spirit exhaling, carries off with it the Oil that causes the Spot. 291. _Balls to take out Stains._ Take an ounce of Quick-lime, half a pound of Soap, and a quarter of a pound of White Clay; moisten the whole with Water, and make it into little balls, with which rub the stains, and afterwards wash them with fair water. 292. _To clean Gold and Silver Lace._ Take the Gall of an Ox and of a Pike, mixed well together in fair Water, and rub the gold or silver with this composition. 293. _To restore to Tapestry its original Lustre._ Shake well, and thoroughly clean the tapestry; then rub it twice over with Chalk, which, after remaining seven or eight hours each time, is to be brushed off with a hard brush; the tapestry being likewise well beaten with a stick, and shaked. 294. _To clean Turkey Carpets._ To revive the colour of a Turkey Carpet, beat it well with a stick, till the dust is all got out; then with Lemon or Sorrel Juice take out the spots of ink, if the carpet be stained with any; wash it in cold Water, and afterwards shake out all the Water from the threads of the carpet. When it is thoroughly dry, rub it all over with the Crumb of a hot Wheaten Loaf; and if the weather is very fine, hang it out in the open air a night or two. 295. _To refresh Tapestry, Carpets, Hangings, or Chairs._ Beat the dust out of them on a dry day as clean as possible, and brush them well with a dry brush. Afterwards rub them well over with a good lather of Castile Soap, laid on with a brush. Wash off the froth with common Water; then wash the tapestry, &c. with Alum Water. When the cloth is dry, you will find most of the colours restored. Those that are yet too faint, touch up with a pencil dipped in suitable colours, and indeed you may run over the whole piece in the same manner with water colours, mixed with weak gum water, and, if well done, it will cause the tapestry, &c. to look at a distance like new. 296. _To take Wax out of Silk or Camblet._ Take Soft Soap, rub it well on the spots of wax, dry it in the sun till it grows very hot, then wash the spotted part with cold Water, and the wax will be entirely taken out. 297. _To take Wax out of Velvet of all Colours except Crimson._ Take a Crummy Wheaten Loaf, cut it in two, toast it before the fire, and while very hot, apply it to the part spotted with wax. Then apply another piece of toasted Bread hot as before, and continue to repeat this application till the wax is entirely taken out. 298. _To wash Gold or Silver Work on Linen, or any other Stuff, so as to look like new._ Take a pound of Ox-gall; Honey and Soap, of each three ounces; Florentine Orrice in fine powder, three ounces; mix the whole in a glass vessel into a Paste, and expose it to the sun during ten days; then make a decoction of Bran, and strain it clear. Plaster over with your bitter Paste, the places you want to clean, and afterwards wash off the Paste with the Bran-water, till the latter is no longer tinged. Then wipe with a clean linen cloth the places you have washed; cover them with a clean napkin, dry them in the sun, press and glaze, and the work will look as well as when new. 299. _To take Spots out of Silken or Woollen Stuffs._ Take a sufficient quantity of the finest Starch, wet it in an earthen pipkin with Brandy, rub a little on the spots, let it dry on them, and then brush it off; repeat this operation till the spots are wholly taken out. You must be careful to beat and brush well the place on which the Starch was applied. 300. _To take Stains of Oil out of Cloth._ Take Oil of Tartar, pour a little on the spot, immediately wash the place with warm Water, and two or three times after with cold Water, and the spot will entirely disappear. 301. _To take Stains out of White Cloth._ Boil an ounce of Alum in a gallon and a half of Water, for half an hour, then add a piece of White Soap, and half a ounce more of Alum, and after it has stood in cold infusion two days, wash with this mixture stains in any kind of white cloth. 302. _To take Stains out of Crimson Velvet, and coloured Velvets._ Take a quart of strong Lee made with Vine Ashes, dissolve in it half an ounce of Alum; and when the mixture has settled, strain it through a linen cloth. Then take half a drachm of soft Soap, and the same quantity of Castile Soap, a drachm of Alum, half a drachm of Crude Sal Armoniac, a scruple of common Salt, a little Loaf Sugar, Juice of Celandine, and the Gall of a Calf; mix the whole well, and strain off the Liquor. When you want to use it, take a little Brazil Wood Shavings with some Scarlet Flocks, boil them in this Liquor, and when strained off, it will be very good to take spots or stains out of crimson velvet or cloth. For velvets or cloths of other colours, you dye your Liquor of the proper colour, by boiling in it some Flocks of the same colour as the cloth you intend to clean. 303. _A Soap that takes out all manner of Spots and Stains._ Take the Yolks of six Eggs, half a table spoonful of bruised Salt, and a pound of Venetian Soap; mix the whole together with the Juice of Beet-roots, and form it into round balls, that are to be dried in the shade. The method of using this Soap is to wet with fair Water the stained part of the cloth, and rub both sides of it well with this Soap; then wash the cloth in Water, and the stain will no longer appear. 304. _Another Method to take Spots or Stains out of White Silk or Crimson Velvet._ First soak the place well with Brandy or Spirit of Wine, then rub it over with the White of a new-laid Egg, and dry it in the sun. Wash it briskly in cold Water, rubbing the place where the spot is, hard between the fingers; and repeat this operation a second and even a third time, if it has not previously succeeded. 305. _A Receipt to clean Gloves without wetting._ Lay the Gloves upon a clean board; and mix together Fuller's Earth and Powder of Alum very dry, which lay over them on both sides with a moderately stiff brush. Then sweep off the Powder, sprinkle them well with Bran and Whiting, and dust them thoroughly. If not very greasy, this will render them as clean as when new; but if they are extremely greasy, rub them with stale Crumb of Bread, and Powder of burnt Bones, then pass them over with a woollen Cloth dipped in Fuller's Earth or Alum Powder. 306. _To colour Gloves._ If you want to colour them of a dark colour, take Spanish Brown and Black Earth; if lighter, Yellow Ochre and Whiting, and so of the rest; mix the colour with Size of a moderate strength, then wet the Gloves over with the Colour, and hang them to dry gradually. Beat out the superfluous Colour, smooth them over with a sleeking stick, and reduce them to a proper size. 307. _To wash Point Lace._ Draw the Lace pretty tight in a frame, then with a lather of Castile Soap a little warm, rub it over gently by means of a fine brush. When you perceive it clean on one side, turn it, and rub the other in the same manner; then throw over the Lace some Alum-water, taking off the Suds, and with some thin Starch go over the wrong side of the Lace; iron it on the same side when dry, and raise the flowers with a bodkin. 308. _To clean Point Lace without washing._ Fix the lace in a frame, and rub it with Crumb of stale Bread, which afterwards dust out. 309. _To wash black and white Sarcenet._ Lay the silk smooth upon a board, spread a little Soap over the dirty places, make a lather with Castile Soap, and with a fine brush dipped in it, pass over the silk the right way, viz. lengthways, and continue so to do till that side is sufficiently scowered. Then turn the silk, scower the other side in the same manner, and put the silk into boiling Water, where it must lie some time; afterwards rince it in thin Gum Water; if white silk, add a little Smalt. This being done, fold the silk, clapping or pressing out the water with your hands on a dry Carpet, till it become tolerably dry; if white, dry it over the Smoak of Brimstone till ready for smoothing, which is to be done on the right side with an Iron moderately hot. 310. _A Soap to take out all Kinds of Stains._ Boil a handful of Strawberries or Strawberry Leaves in a quart of Water and a pint of Vinegar, adding two pounds of Castile Soap; and half a pound of Chalk in fine powder; boil them together till the water has evaporated. When you use it, wet the place with the sharpest Vinegar or Verjuice, and rub it over with this Soap; dry it afterwards before the fire or in the sun. 311. _An expeditious Method to take Stains out of Scarlet, or Velvet of any other Colour._ Take Soapwort, when bruised strain out its Juice, and add to it a small quantity of black Soap. Wash the Stain with this Liquor, suffering it to dry between whiles; and by this means, in a day or two the Spots will disappear. DIFFERENT WAYS OF PREPARING SNUFF. 312. _Method of making Snuff._ First strip off the Stalks and large fibres of the Tobacco, then spread the Leaves on a mat or carpet to dry in the sun, afterwards rub them in a mortar, and sift the powder through a coarse or fine sieve, according to the degree of fineness you would have your snuff; or grind the Tobacco Leaves, prepared in the manner before directed, in a snuff-mill, either into a gross or fine powder, according as you press close or ease the mill-stone. 313. _Method of cleansing Snuff in order to scent it._ Fix a thick linen cloth in a little tub that has a hole in the bottom, stopped with a plug that can easily be taken out, to let the water run off when wanted. This cloth must cover the whole inside of the tub, and be fastened all round the rim. Put your Snuff in it, and pour on the Water. When it has been steeped twenty-four hours, let the Water run out, and pour on fresh; repeat this operation three times, if you would have the Snuff thoroughly cleansed, and every time squeeze the Snuff hard in the cloth, to discharge the Water entirely from it. Then place your Snuff on an ozier hurdle covered with a thick linen cloth, and let it dry in the sun; when it is thoroughly dry, put it again into the tub, with a sufficient quantity of Angelic, Orange Flower, or Rose-water. At the expiration of twenty-four hours take the Snuff out of the water, and dry it as before, frequently stirring it about, and sprinkling it with the same sweet-scented Water as was used at first. The whole of this preparation is absolutely necessary to render Snuff fit to receive the scent of Flowers. If the Snuff is not required to be of a very excellent quality, and you are unwilling to waste more of it than can possibly be avoided, wash it only once, and slightly cleanse it. This purgation may the better suffice, if while drying in the sun, you take care to knead the Snuff into a cake several times, and often sprinkle it with some sweet-scented Water. 314. _Method of scenting Snuff._ The Flowers that most readily communicate their flavour to Snuff are Orange Flowers, Jasmine, Musk Roses, and Tuberoses. You must procure a box lined with dry white paper; in this strow your Snuff on the bottom about the thickness of an inch, over which place a thin layer of Flowers, then another layer of Snuff, and continue to lay your Flowers and Snuff alternately in this manner, until the box is full. After they have lain together four and twenty hours, sift your Snuff through a sieve to separate it from the Flowers, which are to be thrown away, and fresh ones applied in their room in the former method. Continue to do this till the Snuff is sufficiently scented; then put it into a canister, which keep close stopped. 315. _Or,_ Put your Flowers that are placed over each layer of the Snuff, between two pieces of white paper pricked full of holes with a large pin, and sift through a sieve the Snuff that may happen to get between the papers. To scent the Snuff perfectly it is necessary to renew the Flowers four or five times. This method is the least troublesome of the two. A very agreeable scented Snuff may be made with Roses, by taking Rose-buds, stripping off the green cup, and pistil that rises in the middle, and fixing in its place a Clove; being careful not to separate the Leaves that are closed together. The Rose-buds thus prepared, are to be exposed to the heat of the sun a whole month, inclosed in a glass well stopped, and are then fit for use. To make Snuff scented with a thousand Flowers, take a number of different Flowers, and mix them together, proportioning the quantity of each Flower, to the degree of its perfume, so that the flavour of no one particular Flower may be predominant. 316. _Perfumed Snuff._ Take some Snuff, and rub it in your hands with a little Civet, opening the body of the Civet still more by rubbing it in your hands with fresh Snuff; and when you have mixed it perfectly with the Snuff, put them into a canister. Snuff is flavoured with other perfumes in the same way. 317. _Or,_ Perfume your Snuff by mixing it well with the hands, in a heated iron or brass mortar, besmeared with a few grains of Ambergrise. 318. _Snuff after the Maltese Fashion._ Perfume with Ambergrise, in the manner already described, some Snuff previously scented with Orange Flowers. Then grind in a mortar a little Sugar with about ten grains of Civet, and mix by little and little with about a pound of the foregoing Snuff. 319. _The Genuine Maltese Snuff._ Take Roots of Liquorice, and Roots of the Rose-bush, peel off their outer skin, dry them, powder them, and sift the powder through a fine sieve, then scent them according to your fancy, or in the same manner as French Snuff, adding a little White Wine, Brandy, or a very little Spirit of Wine, and rubbing the Snuff well between your hands. 320. _Italian Snuff._ Put into a mortar, or other convenient vessel, a quantity of Snuff already scented with some Flower, pour on it a little White Wine, and add, if agreeable, some Essence of Ambergrise, Musk, or any other Perfume you like best; stir the Snuff and rub it well between your hands. Scent Snuff in this manner with any particular flavour, and put the different scented Snuffs in separate boxes, which are to be marked, to prevent mistakes. 321. _Snuff scented after the Spanish Manner._ Take a lump of double-refined Sugar, rub it in a mortar with twenty grains of Musk; add by little and little a pound of Snuff, and grind the whole with ten grains of Civet, rubbing it afterwards well between your hands. Seville Snuff is scented with twenty grains of Vanilloes only. Keep your Snuff in canisters closely stopped, to prevent the scent from exhaling. As Spanish Snuff is very fine and of a reddish colour, to imitate it nicely, take the best Dutch Snuff, well cleansed, granulated, and coloured red; beat it fine, and sift it through a very fine lawn sieve. After it has been cleansed according to the foregoing directions, it is fit to take any scent whatever. There is no risk in using a sieve that retains the scent of any Flower, to perfume your Snuff with the flavour of Musk, Ambergrise, or any other Perfume. On the contrary, the Snuff receives the Perfume the more readily, and preserves its flavour the longer on that account. 322. _Method of dying Snuff Red or Yellow._ Take the size of a nut or two of Yellow or Red Ochre, and to temper the colour mix with it a little White Chalk. Grind these colours on a marble, with a little less than half an ounce of Oil of Sweet Almonds, and moisten with as much Water as the colour will take up, till it becomes a smooth Paste. Then mix it with a thin Mucilage of Gum Tragacanth to a proper consistence, and put it into an earthen dish, stirring into it about a pint more of Water. Afterwards take any quantity of cleansed Snuff you please, throw it upon the colour, and rub it well between your hands. When the Paste is thoroughly tinged with the colour, leave it till next morning to settle, then spread it thin on a cloth to dry, and place it in the sun, stirring it about every now and then that it may dry equally. When dry, gum it with a very thin Mucilage of Gum Tragacanth made with some sweet-scented Water. To gum the Snuff as equally as possible, wet the palms of your hands with this Gum Water, and rub the Snuff well between them. Afterwards dry it in the sun, and sift the colour that does not adhere to it through a very fine sieve. The Snuff is then properly prepared to receive any flavour you choose. 323. _Herb Snuff._ Take Sweet Marjoram, Marum Syriacum Leaves, and Lavender Flowers dried, of each half an ounce, Asarabacca Leaves, a drachm. Rub them all into a powder. 324. _Or,_ Take Betony Leaves and Marjoram, of each half an ounce; Asarabacca Leaves, a drachm. Beat them together into a powder. 325. _Or,_ Take Marjoram, Rosemary Flowers, Betony, and Flowers of Lilies of the Valley, of each a quarter of an ounce; Nutmegs, a drachm and a half; Volatile Salt, forty drops. Powder, and keep the mixture in a phial, close stopped. 326. _Or,_ Take Flowers of Lavender, and Clove-july-flowers, of each a quarter of an ounce; Lilies of the Valley, Tiel-tree Flowers, Flowers of Sage, Betony, Rosemary, and Tops of Marjoram, of each half a drachm; Cinnamon, Aloes-wood, Yellow Sanders, and White Helebore-root, of each a drachm; Oil of Nutmegs and Oil of Lemons, of each three drops; mix them into a powder. A pinch or two of any of these Snuffs may be taken night and morning medicinally, or at any time for pleasure. Used externally, they are serviceable for weak eyes and many disorders of the organs of sight and hearing. They also relieve headaches, giddiness, palsies, lethargies, besides a variety of other complaints; and are, though agreeable and simple, far superior to what is sold under the name of Herb Snuff. FINIS. Transcriber's Notes. There were large number of printing errors in this publication. The following words have been changed: Eition is now edition To it is now it to Receips is now receipts Cassolete is now cassolette Whitloes is now whitlows With with was repeated and amended Fisrt is now first Aftewards is now afterwards Died is now dyed Magisterail magisterial Gont is now gout Agrreeable is now agreeable Viguor is now vigour Suprisingly is now surprisingly Chich is now chick Squeese is now squeeze Quantiiy is now quantity Aud is now and Cloaths is now clothes Und is now and Plantane is now plantain 
34114	----	Soap-Making Manual A practical handbook on the raw materials, their manipulation, analysis and control in the modern soap plant. By _E. G. Thomssen, Ph. D._ ILLUSTRATED NEW YORK D. VAN NOSTRAND COMPANY EIGHT WARREN STREET 1922 COPYRIGHT 1922 BY D. VAN NOSTRAND COMPANY Printed in the United States of America * * * * * Transcriber's note: This is a series of articles collected into a book. There are differences in spelling and punctuation in the different chapters (e.g. cocoanut in one chapter and coconut in another). These differences were left in the text as they appeared. For Text: A word surrounded by a tilde such as ~this~ signifies that the word is bolded in the text. A word surrounded by underscores like _this_ signifies the word is italics in the text. For numbers and equations: Parentheses have been added to clarify fractions. Underscores before bracketed numbers in equations denote a subscript. Minor typos have been corrected and footnotes moved to the end of the chapters. * * * * * PREFATORY NOTE. The material contained in this work appeared several years ago in serial form in the American Perfumer and Essential Oil Review. Owing to the numerous requests received, it has been decided to now place before those interested, these articles in book form. While it is true that the works pertaining to the soapmaking industry are reasonably plentiful, books are quite rare, however, which, in a brief volume, will clearly outline the processes employed together with the necessary methods of analyses from a purely practical standpoint. In the work presented the author has attempted to briefly, clearly, and fully explain the manufacture of soap in such language that it might be understood by all those interested in this industry. In many cases the smaller plants find it necessary to dispense with the services of a chemist, so that it is necessary for the soapmaker to make his own tests. The tests outlined, therefore, are given as simple as possible to meet this condition. The formulae submitted are authentic, and in many cases are now being used in soapmaking. In taking up the industry for survey it has been thought desirable to first mention and describe the raw materials used; second, to outline the processes of manufacture; third, to classify the methods and illustrate by formulae the composition of various soaps together with their mode of manufacture; fourth, to enumerate the various methods of glycerine recovery, including the processes of saponification, and, fifth, to give the most important analytical methods which are of value to control the process of manufacture and to determine the purity and fitness of the raw material entering into it. It is not the intention of the author to go into great detail in this work, nor to outline to any great extent the theoretical side of the subject, but rather to make the work as brief as possible, keeping the practical side of the subject before him and not going into concise descriptions of machinery as is very usual in works on this subject. Illustrations are merely added to show typical kinds of machinery used. The author wishes to take this opportunity of thanking Messrs. L. S. Levy and E. W. Drew for the reading of proof, and Mr. C. W. Aiken of the Houchin-Aiken Co., for his aid in making the illustrations a success, as well as others who have contributed in the compiling of the formulae for various soaps. He trusts that this work may prove of value to those engaged in soap manufacture. E. G. T. January, 1922 TABLE OF CONTENTS. CHAPTER I. Page. RAW MATERIALS USED IN SOAP MAKING 1-30 1. Soap Defined 1 2. Oils and Fats 1-2 3. Saponification Defined 2-3 4. Fats and Oils Used in Soap Manufacture 3-4 Fullers' Earth Process for Bleaching Tallow 4-6 Method for Further Improvement of Color in Tallow 6 Vegetable Oils 6-9 Chrome Bleaching of Palm Oil 9-12 Air Bleaching of Palm Oil 12-16 5. Rancidity of Oils and Fats 16-18 Prevention of Rancidity 18 6. Chemical Constants of Oils and Fats 18-19 7. Oil Hardening or Hydrogenating 19-21 8. Grease 21-22 9. Rosin (Colophony, Yellow Rosin, Resina) 22-23 10. Rosin Saponification 23-24 11. Naphthenic Acids 24-25 12. Alkalis 25-26 Caustic Soda 26 Caustic Potash 26-28 Sodium Carbonate (Soda Ash) 28-29 Potassium Carbonate 29 13. Additional Material Used in Soap Making 29-30 CHAPTER II. CONSTRUCTION AND EQUIPMENT OF A SOAP PLANT 31-34 CHAPTER III. CLASSIFICATION OF SOAP MAKING METHODS 35-46 1. Full Boiled Soaps 36-42 2. Cold Process 43-44 3. Carbonate Saponification 45-46 CHAPTER IV. CLASSIFICATION OF SOAPS 47-104 1. Laundry Soap 48 Semi-Boiled Laundry Soap 49-50 Settled Rosin Soap 50-54 2. Chip Soap 54-55 Cold Made Chip Soap 55-56 Unfilled Chip Soap 56 3. Soap Powders 56-59 Light Powders 60-61 4. Scouring Powders 61 5. Scouring Soap 61-62 6. Floating Soap 62-65 7. Toilet Soap 65-68 Cheaper Toilet Soaps 68-69 Run and Glued-up Soaps 69-71 Curd Soap 71-72 Cold Made Toilet Soaps 72-73 Perfuming and Coloring Toilet Soaps 73-75 Coloring Soap 75-76 8. Medicinal Soaps 76-77 Sulphur Soaps 77 Tar Soap 77 Soaps Containing Phenols 77-78 Peroxide Soap 78 Mercury Soaps 78 Less Important Medicinal Soaps 78-79 9. Castile Soap 79-81 10. Eschweger Soap 81-82 11. Transparent Soap 82-84 Cold Made Transparent Soap 84-87 12. Shaving Soaps 87-90 Shaving Powder 90 Shaving Cream 90-93 13. Pumice or Sand Soaps 93-94 14. Liquid Soaps 94-95 15. Use of Hardened Oils in Toilet Soaps 96-98 16. Textile Soaps 98 Scouring and Fulling Soaps for Wool 98-100 Wool Thrower's Soap 100-101 Worsted Finishing Soaps 101 Soaps Used in the Silk Industry 101-103 Soaps Used for Cotton Goods 103-104 17. Sulphonated Oils 104-105 CHAPTER V. GLYCERINE RECOVERY 105-126 1. Methods of Saponification 105-106 Recovery of Glycerine from Spent Lye 106-113 Twitchell Process 113-118 Autoclave Saponification 118 Lime Saponification 118-120 Acid Saponification 120-121 Aqueous Saponification 121 Splitting Fats with Ferments 121-123 Krebitz Process 123-125 2. Distillation of Fatty Acids 125-126 CHAPTER VI. ANALYTICAL METHODS 127-164 1. Analysis of Oils and Fats 128 Free Fatty Acids 128-130 Moisture 130 Titer 130-132 Determination of Unsaponifiable Matter 132-133 Test for Color of Soap 133-134 Testing of Alkalis Used in Soap Making 134-137 2. Soap Analysis 137-138 Moisture 138-139 Free Alkali or Acid 139-142 Insoluble Matter 143 Starch and Gelatine 143-144 Total Fatty and Resin Acids 144 Determination of Rosin 144-147 Total Alkali 147-148 Unsaponifiable Matter 148 Silica and Silicates 148-149 Glycerine in Soap 149-150 Sugar in Soap 150 3. Glycerine Analysis 150-151 Sampling 151 Analysis 151-154 Acetin Process for the Determination of Glycerol 155-156 The Method 156-159 Ways of Calculating Actual Glycerol Contents 159-160 Bichromate Process for Glycerol Determination Reagents Required 160-161 The Method 161-162 Sampling Crude Glycerine 162-164 CHAPTER VII STANDARD METHODS FOR THE SAMPLING AND ANALYSIS OF COMMERCIAL FATS AND OILS 165-195 1. Scope, Applicability and Limitations of the Methods 165-166 Scope 165 Applicability 166 Limitations 166 Sampling 166-169 Tank Cars 166-167 Barrels, Tierces, Casks, Drums, and Other Packages 168 2. Analysis 169-183 Sample 169 Moisture and Volatile Matter 170-172 Insoluble Impurities 172-173 Soluble Mineral Matter 173 Free Fatty Acids 174 Titer 174-175 Unsaponifiable Matter 176-177 Iodine Number-Wijs Method 177-181 Saponification Number (Koettstorfer Number) 181 Melting Point 181-182 Cloud Test 182-184 3. Notes of the Above Methods 184-196 Sampling 183 Moisture and Volatile Matter 184-187 Insoluble Impurities 187 Soluble Mineral Matter 187-188 Free Fatty Acid 188-189 Titer 189 Unsaponified Matter 190-193 Melting Point 193-196 Plant and Machinery 198-219 Illustrations of Machinery and Layouts of the Plant of a Modern Soap Making Establishment 198-219 Appendix 219-237 Useful Tables Index 239 CHAPTER I Raw Materials Used in Soap Making. Soap is ordinarily thought of as the common cleansing agent well known to everyone. In a general and strictly chemical sense this term is applied to the salts of the non-volatile fatty acids. These salts are not only those formed by the alkali metals, sodium and potassium, but also those formed by the heavy metals and alkaline earths. Thus we have the insoluble soaps of lime and magnesia formed when we attempt to wash in "hard water"; again aluminum soaps are used extensively in polishing materials and to thicken lubricating oils; ammonia or "benzine" soaps are employed among the dry cleaners. Commonly, however, when we speak of soap we limit it to the sodium or potassium salt of a higher fatty acid. It is very generally known that soap is made by combining a fat or oil with a water solution of sodium hydroxide (caustic soda lye), or potassium hydroxide (caustic potash). Sodium soaps are always harder than potassium soaps, provided the same fat or oil is used in both cases. The detergent properties of soap are due to the fact that it acts as an alkali regulator, that is, when water comes into contact with soap, it undergoes what is called hydrolytic dissociation. This means that it is broken down by water into other substances. Just what these substances are is subject to controversy, though it is presumed caustic alkali and the acid alkali salt of the fatty acids are formed. OILS AND FATS. There is no sharp distinction between fat and oil. By "oil" the layman has the impression of a liquid which at warm temperature will flow as a slippery, lubricating, viscous fluid; by "fat" he understands a greasy, solid substance unctuous to the touch. It thus becomes necessary to differentiate the oils and fats used in the manufacture of soap. Inasmuch as a soap is the alkali salt of a fatty acid, the oil or fat from which soap is made must have as a constituent part, these fatty acids. Hydrocarbon oils or paraffines, included in the term "oil," are thus useless in the process of soap-making, as far as entering into chemical combination with the caustic alkalis is concerned. The oils and fats which form soap are those which are a combination of fatty acids and glycerine, the glycerine being obtained as a by-product to the soap-making industry. NATURE OF A FAT OR OIL USED IN SOAP MANUFACTURE. Glycerine, being a trihydric alcohol, has three atoms of hydrogen which are replaceable by three univalent radicals of the higher members of the fatty acids, _e. g._, OH OR C_{3} H_{5} OH + 3 ROH = C_{3} H_{5} OR + 3 H_{2}O OH OR Glycerine plus 3 Fatty Alcohols equals Fat or Oil plus 3 Water. Thus three fatty acid radicals combine with one glycerine to form a true neutral oil or fat which are called triglycerides. The fatty acids which most commonly enter into combination of fats and oils are lauric, myristic, palmitic, stearic and oleic acids and form the neutral oils or triglycerides derived from these, _e. g._, stearin, palmatin, olein. Mono and diglycerides are also present in fats. SAPONIFICATION DEFINED. When a fat or oil enters into chemical combination with one of the caustic hydrates in the presence of water, the process is called "saponification" and the new compounds formed are soap and glycerine, thus: OR OH C_{3}H_{5} OR + 3 NaOH = C_{3}H_{5} OH + 3 NaOR OR OH Fat or Oil plus 3 Sodium Hydrate equals Glycerine plus 3 Soap. It is by this reaction almost all of the soap used today is made. There are also other means of saponification, as, the hydrolysis of an oil or fat by the action of hydrochloric or sulfuric acid, by autoclave and by ferments or enzymes. By these latter processes the fatty acids and glycerine are obtained directly, no soap being formed. FATS AND OILS USED IN SOAP MANUFACTURE. The various and most important oils and fats used in the manufacture of soap are, tallow, cocoanut oil, palm oil, olive oil, poppy oil, sesame oil, soya bean oil, cotton-seed oil, corn oil and the various greases. Besides these the fatty acids, stearic, red oil (oleic acid) are more or less extensively used. These oils, fats and fatty acids, while they vary from time to time and to some extent as to their color, odor and consistency, can readily be distinguished by various physical and chemical constants. Much can be learned by one, who through continued acquaintance with these oils has thoroughly familiarized himself with the indications of a good or bad oil, by taste, smell, feel and appearance. It is, however, not well for the manufacturer in purchasing to depend entirely upon these simpler tests. Since he is interested in the yield of glycerine, the largest possible yield of soap per pound of soap stock and the general body and appearance of the finished product, the chemical tests upon which these depend should be made. Those especially important are the acid value, percentage unsaponifiable matter and titer test. A short description of the various oils and fats mentioned is sufficient for their use in the soap industry. _Tallow_ is the name given to the fat extracted from the solid fat or "suet" of cattle, sheep or horses. The quality varies greatly, depending upon the seasons of the year, the food and age of the animal and the method of rendering. It comes to the market under the distinction of edible and inedible, a further distinction being made in commerce as beef tallow, mutton tallow or horse tallow. The better quality is white and bleaches whiter upon exposure to air and light, though it usually has a yellowish tint, a well defined grain and a clean odor. It consists chiefly of stearin, palmitin and olein. Tallow is by far the most extensively used and important fat in the making of soap. In the manufacture of soaps for toilet purposes, it is usually necessary to produce as white a product as possible. In order to do this it often is necessary to bleach the tallow before saponification. The method usually employed is the Fuller's Earth process. FULLER'S EARTH PROCESS FOR BLEACHING TALLOW. From one to two tons of tallow are melted out into the bleaching tank. This tank is jacketed, made of iron and provided with a good agitator designed to stir up sediment or a coil provided with tangential downward opening perforations and a draw-off cock at the bottom. The coil is the far simpler arrangement, more cleanly and less likely to cause trouble. By this arrangement compressed air which is really essential in the utilization of the press (see later) is utilized for agitation. A dry steam coil in an ordinary tank may be employed in place of a jacketed tank, which lessens the cost of installation. The tallow in the bleaching tank is heated to 180° F. (82° C.) and ten pounds of dry salt per ton of fat used added and thoroughly mixed by agitation. This addition coagulates any albumen and dehydrates the fat. The whole mass is allowed to settle over night where possible, or for at least five hours. Any brine which has separated is drawn off from the bottom and the temperature of the fat is then raised to 160° F. (71° C). Five per cent. of the weight of the tallow operated upon, of dry Fuller's earth is now added and the whole mass agitated from twenty to thirty minutes. The new bleached fat, containing the Fuller's earth is pumped directly to a previously heated filter press and the issuing clear oil run directly to the soap kettle. One of the difficulties experienced in the process is the heating of the press to a temperature sufficient to prevent solidification of the fat without raising the press to too great a temperature. To overcome this the first plate is heated by wet steam. Air delivered from a blower and heated by passage through a series of coils raised to a high temperature by external application of heat (super-heated steam) is then substituted for the steam. The moisture produced by the condensation of the steam is vaporized by the hot air and carried on gradually to each succeeding plate where it again condenses and vaporizes. In this way the small quantity of water is carried through the entire press, raising its temperature to 80°-100° C. This temperature is subsequently maintained by the passage of hot air. By this method of heating the poor conductivity of hot air is overcome through the intermediary action of a liquid vapor and the latent heat of steam is utilized to obtain the initial rise in temperature. To heat a small press economically where conditions are such that a large output is not required the entire press may be encased in a small wooden house which can be heated by steam coils. The cake in the press is heated for some time after the filtration is complete to assist drainage. After such treatment the cake should contain approximately 15 per cent. fat and 25 per cent. water. The cake is now removed from the press and transferred to a small tank where it is treated with sufficient caustic soda to convert the fat content into soap. Saturated brine is then added to salt out the soap, the Fuller's earth is allowed to settle to the bottom of the tank and the soap which solidifies after a short time is skimmed off to be used in a cheap soap where color is not important. The liquor underneath may also be run off without disturbing the sediment to be used in graining a similar cheap soap. The waste Fuller's earth contains about 0.1 to 0.3 per cent. of fat. METHOD FOR FURTHER IMPROVEMENT OF COLOR. A further improvement of the color of the tallow may be obtained by freeing it from a portion of its free fatty acids, either with or without previous Fuller's earth bleaching. To carry out this process the melted fat is allowed to settle and as much water as possible taken off. The temperature is then raised to 160° F. with dry steam and enough saturated solution of soda ash added to remove 0.5 per cent. of the free fatty acids, while agitating the mass thoroughly mechanically or by air. The agitation is continued ten minutes, the whole allowed to settle for two hours and the foots drawn off. The soap thus formed entangles a large proportion of the impurities of the fat. VEGETABLE OILS. _Cocoanut Oil_, as the name implies, is obtained from the fruit of the cocoanut palm. This oil is a solid, white fat at ordinary temperature, having a bland taste and a characteristic odor. It is rarely adulterated and is very readily saponified. In recent years the price of this oil has increased materially because cocoanut oil is now being used extensively for edible purposes, especially in the making of oleomargarine. Present indications are that shortly very little high grade oil will be employed for soap manufacture since the demand for oleomargarine is constantly increasing and since new methods of refining the oil for this purpose are constantly being devised. The oil is found in the market under three different grades: (1) Cochin cocoanut oil, the choicest oil comes from Cochin (Malabar). This product, being more carefully cultivated and refined than the other grades, is whiter, cleaner and contains a smaller percentage of free acid. (2) Ceylon cocoanut oil, coming chiefly from Ceylon, is usually of a yellowish tint and more acrid in odor than Cochin oil. (3) Continental cocoanut oil (Copra, Freudenberg) is obtained from the dried kernels, the copra, which are shipped to Europe in large quantities, where the oil is extracted. These dried kernels yield 60 to 70 per cent oil. This product is generally superior to the Ceylon oil and may be used as a very satisfactory substitute for Cochin oil, in soap manufacture, provided it is low in free acid and of good color. The writer has employed it satisfactorily in the whitest and finest of toilet soaps without being able to distinguish any disadvantage to the Cochin oil. Since continental oil is usually cheaper than Cochin oil, it is advisable to use it, as occasion permits. Cocoanut oil is used extensively in toilet soap making, usually in connection with tallow. When used alone the soap made from this oil forms a lather, which comes up rapidly but which is fluffy and dries quickly. A pure tallow soap lathers very much slower but produces a more lasting lather. Thus the advantage of using cocoanut oil in soap is seen. It is further used in making a cocoanut oil soap by the cold process also for "fake" or filled soaps. The fatty acid content readily starts the saponification which takes place easily with a strong lye (25°-35° B.). Where large quantities of the oil are saponified care must be exercised as the soap formed suddenly rises or puffs up and may boil over. Cocoanut oil soap takes up large quantities of water, cases having been cited where a 500 per cent. yield has been obtained. This water of course dries out again upon exposure to the air. The soap is harsh to the skin, develops rancidity and darkens readily. _Palm Kernel Oil_, which is obtained from the kernels of the palm tree of West Africa, is used in soap making to replace cocoanut oil where the lower price warrants its use. It resembles cocoanut oil in respect to saponification and in forming a very similar soap. Kernel oil is white in color, has a pleasant nutty odor when fresh, but rapidly develops free acid, which runs to a high percentage. _Palm Oil_ is produced from the fruit of the several species of the palm tree on the western coast of Africa generally, but also in the Philippines. The fresh oil has a deep orange yellow tint not destroyed by saponification, a sweetish taste and an odor of orris root or violet which is also imparted to soap made from it. The methods by which the natives obtain the oil are crude and depend upon a fermentation, or putrefaction. Large quantities are said to be wasted because of this fact. The oil contains impurities in the form of fermentable fibre and albuminous matter, and consequently develops free fatty acid rapidly. Samples tested for free acid have been found to have hydrolized completely and one seldom obtains an oil with low acid content. Because of this high percentage of free fatty acid, the glycerine yield is small, though the neutral oil should produce approximately 12 per cent. glycerine. Some writers claim that glycerine exists in the free state in palm oil. The writer has washed large quantities of the oil and analyzed the wash water for glycerine. The results showed that the amount present did not merit its recovery. Most soap makers do not attempt to recover the glycerine from this oil, when used alone for soap manufacture. There are several grades of palm oil in commerce, but in toilet soap making it is advisable to utilize only Lagos palm oil, which is the best grade. Where it is desired to maintain the color of the soap this oil produces, a small quantity of the lower or "brass" grade of palm oil may be used, as the soap made from the better grades of oil gradually bleaches and loses its orange yellow color. Palm oil produces a crumbly soap which cannot readily be milled and is termed "short." When used with tallow and cocoanut oil, or 20 to 25 per cent. cocoanut oil, it produces a very satisfactory toilet soap. In the saponification of palm oil it is not advisable to combine it with tallow in the kettle, as the two do not readily mix. Since the finished soap has conveyed to it the orange color of the oil, the oil is bleached before saponification. Oxidation readily destroys the coloring matter, while heat and light assist materially. The methods generally employed are by the use of oxygen developed by bichromates and hydrochloric acid and the direct bleaching through the agency of the oxygen of the air. CHROME BLEACHING OF PALM OIL. The chrome process of bleaching palm oil is more rapid and the oxygen thus derived being more active will bleach oils which air alone cannot. It depends upon the reaction: Na_{2}Cr_{2}O_{7} + 8HCl = Cr_{2}Cl_{6} + 2NaCl + 7O. in which the oxygen is the active principle. In practice it is found necessary to use an excess of acid over that theoretically indicated. For the best results an oil should be chosen containing under 2 per cent. impurities and a low percentage of free fatty acids. Lagos oil is best adapted to these requirements. The oil is melted by open steam from a jet introduced through the bung, the melted oil and condensed water running to the store tank through two sieves (about 1/8 inch mesh) to remove the fibrous material and gross impurities. The oil thus obtained contains fine earthy and fibrous material and vegetable albuminous matter which should be removed, as far as possible, since chemicals are wasted in their oxidation and they retard the bleaching. This is best done by boiling the oil for one hour with wet steam and 10 per cent. solution of common salt (2 per cent. dry salt on weight of oil used) in a lead-lined or wooden tank. After settling over night the brine and impurities are removed by running from a cock at the bottom of the vat and the oil is run out into the bleaching tank through an oil cock, situated about seven inches from the bottom. The bleaching tank is a lead-lined iron tank of the approximate dimensions of 4 feet deep, 4 feet long and 3-1/2 feet wide, holding about 1-1/2 tons. The charge is one ton. A leaden outlet pipe is fixed at the bottom, to which is attached a rubber tube closed by a screw clip. A plug also is fitted into the lead outlet pipe from above. Seven inches above the lower outlet is affixed another tap through which the oil is drawn off. The tank is further equipped with a wet steam coil and a coil arranged to allow thorough air agitation, both coils being of lead. A good arrangement is to use one coil to deliver either air or steam. These coils should extend as nearly as possible over the entire bottom of the tank and have a number of small downward perforations, so as to spread the agitation throughout the mass. The temperature of the oil is reduced by passing in air to 110° F. and 40 pounds of fine common salt per ton added through a sieve. About one-half of the acid (40 pounds of concentrated commercial hydrochloric acid) is now poured in and this is followed by the sodium bichromate in concentrated solution, previously prepared in a small lead vat or earthen vessel by dissolving 17 pounds of bichromate in 45 pounds commercial hydrochloric acid. This solution should be added slowly and should occupy three hours, the whole mass being thoroughly agitated with air during the addition and for one hour after the last of the bleaching mixture has been introduced. The whole mixture is now allowed to settle for one hour and the exhausted chrome liquors are then run off from the lower pipe to a waste tank. About 40 gallons of water are now run into the bleached oil and the temperature raised by open steam to 150° to 160° F. The mass is then allowed to settle over night. One such wash is sufficient to remove the spent chrome liquor completely, provided ample time is allowed for settling. A number of washings given successively with short periods of settling do not remove the chrome liquors effectually. The success of the operation depends entirely upon the completeness of settling. The wash water is drawn off as before and the clear oil run to storage tanks or to the soap kettle through the upper oil cock. The waste liquors are boiled with wet steam and the oil skimmed from the surface, after which the liquors are run out through an oil trap. By following the above instructions carefully it is possible to bleach one ton of palm oil with 17 pounds of bichromate of soda and 85 pounds hydrochloric acid. The spent liquors should be a bright green color. Should they be of a yellow or brownish shade insufficient acid has been allowed and more must be added to render the whole of the oxygen available. If low grade oils are being treated more chrome will be necessary, the amount being best judged by conducting the operation as usual and after the addition of the bichromate, removing a sample of the oil, washing the sample and noting the color of a rapidly cooled sample. A little practice will enable the operator to judge the correspondence between the color to be removed and the amount of bleaching mixture to be added. To obtain success with this process the method of working given must be adhered to even in the _smallest detail_. This applies to the temperature at which each operation is carried out particularly. AIR BLEACHING OF PALM OIL. The method of conducting this process is identical with the chrome process to the point where the hydrochloric acid is to be added to the oil. In this method no acid or chrome is necessary, as the active bleaching agent is the oxygen of the air. The equipment is similar to that of the former process, except that a wooden tank in which no iron is exposed will suffice to bleach the oil in. The process depends in rapidity upon the amount of air blown through the oil and its even distribution. Iron should not be present or exposed to the oil during bleaching, as it retards the process considerably. After the impurities have been removed, as outlined under the chrome process, the temperature of the oil is raised by open steam to boiling. The steam is then shut off and air allowed to blow through the oil until it is completely bleached, the temperature being maintained above 150° F. by occasionally passing in steam. Usually a ton of oil is readily and completely bleached after the air has been passed through it for 18 to 20 hours, provided the oil is thoroughly agitated by a sufficient flow of air. If the oil has been allowed to settle over night, it is advisable to run off the condensed water and impurities by the lower cock before agitating again the second day. When the oil has been bleached to the desired color, which can be determined by removing a sample and cooling, the mass is allowed to settle, the water run off to a waste tank from which any oil carried along may be skimmed off and the supernatant clear oil run to the storage or soap kettle. In bleaching by this process, while the process consumes more time and is not as efficient in bleaching the lower grade oils, the cost of bleaching is less and with a good oil success is more probable, as there is no possibility of any of the chrome liquors being present in the oil. These give the bleached oil a green tint when the chrome method is improperly conducted and they are not removed. Instead of blowing the air through it, the heater oil may be brought into contact with the air, either by a paddle wheel arrangement, which, in constantly turning, brings the oil into contact with the air, or by pumping the heated oil into an elevated vessel, pierced with numerous fine holes from which the oil continuously flows back into the vessel from which the oil is pumped. While in these methods air, light and heat act simultaneously in the bleaching of the oil, the equipment required is too cumbersome to be practical. Recent investigations[1] in bleaching palm oil by oxygen have shown that not only the coloring matter but the oil itself was affected. In bleaching palm oil for 30 hours with air the free fatty acid content rose and titer decreased considerably. _Olive Oil_, which comes from the fruit of the olive trees, varies greatly in quality, according to the method by which it is obtained and according to the tree bearing the fruit. Three hundred varieties are known in Italy alone. Since the larger portion of olive oil is used for edible purposes, a lower grade, denatured oil, denatured because of the tariff, is used for soap manufacture in this country. The oil varies in color from pale green to golden yellow. The percentage of free acid in this oil varies greatly, though the oil does not turn rancid easily. It is used mainly in the manufacture of white castile soap. Olive oil foots, which is the oil extracted by solvents after the better oil is expressed, finds its use in soap making mostly in textile soaps for washing and dyeing silks and in the production of green castile soaps. Other oils, as poppy seed oil, sesame oil, cottonseed oil, rape oil, peanut (arachis) oil, are used as adulterants for olive oil, also as substitutes in the manufacture of castile soap, since they are cheaper than olive oil. _Cottonseed Oil_ is largely used in the manufacture of floating and laundry soaps. It may be used for toilet soaps where a white color is not desired, as yellow spots appear on a finished soap in which it has been used after having been in stock a short time. _Corn Oil and Soya Bean Oil_ are also used to a slight extent in the manufacture of toilet soaps, although the oils form a soap of very little body. Their soaps also spot yellow on aging. Corn oil finds its greatest use in the manufacture of soap for washing automobiles. It is further employed for the manufacture of cheap liquid soaps. _Fatty Acids_ are also used extensively in soap manufacture. While the soap manufacturer prefers to use a neutral oil or fat, since from these the by-product glycerine is obtained, circumstances arise where it is an advantage to use the free fatty acids. Red oil (oleic acid, elaine) and stearic acid are the two fatty acids most generally bought for soap making. In plants using the Twitchell process, which consists in splitting the neutral fats and oils into fatty acids and glycerine by dilute sulphuric acid and producing their final separation by the use of so-called aromatic sulphonic acids, these fatty acids consisting of a mixture of oleic, stearic, palmitic acids, etc., are used directly after having been purified by distillation, the glycerine being obtained from evaporating the wash water. Oleic acid (red oil) and stearic acid are obtained usually by the saponification of oils, fats and greases by acid, lime or water under pressure or Twitchelling. The fatty acids thus are freed from their combination with glycerine and solidify upon cooling, after which they are separated from the water and pressed at a higher or lower temperature. The oleic acid, being liquid at ordinary temperature, together with some stearic and palmitic acid, is thus pressed out. These latter acids are usually separated by distillation, combined with the press cake further purified and sold as stearic acid. The red oil, sometimes called saponified red oil, is often semi-solid, resembling a soft tallow, due to the presence of stearic acid. The distilled oils are usually clear, varying in color from light to a deep brown. Stearic acid, which reaches the trade in slab form, varies in quality from a soft brown, greasy, crumbly solid of unpleasant odor to a snow white, wax-like, hard, odorless mass. The quality of stearic acid is best judged by the melting point, since the presence of any oleic acid lowers this. The melting point of the varieties used in soap manufacture usually ranges from 128° to 132° F. Red oil is used in the manufacture of textile soaps, replacing olive oil foots soap for this purpose, chlorophyll being used to color the soap green. Stearic acid, being the hard firm fatty acid, may be used in small quantities to give a better grade of soap body and finish. In adding this substance it should always be done in the crutcher, as it will not mix in the kettle. It finds its largest use for soap, however, in the manufacture of shaving soaps and shaving creams, since it produces the non-drying creamy lather so greatly desired for this purpose. Both red oil and stearic acid being fatty acids, readily unite with the alkali carbonates, carbon dioxide being formed in the reaction and this method is extensively used in the formation of soap from them. RANCIDITY OF OILS AND FATS. Rancidity in neutral oils and fats is one of the problems the soap manufacturer has to contend with. The mere saying that an oil is rancid is no indication of its being high in free acid. The two terms rancidity and acidity are usually allied. Formerly, the acidity of a fat was looked upon as the direct measure of its rancidity. This idea is still prevalent in practice and cannot be too often stated as incorrect. Fats and oils may be _acid_, or _rancid_, or _acid and rancid_. In an acid fat there has been a hydrolysis of the fat and it has developed a rather high percentage of free acid. A rancid fat is one in which have been developed compounds of an odoriferous nature. An acid and rancid fat is one in which both free acid and organic compounds of the well known disagreeable odors have been produced. It cannot be definitely stated just how this rancidity takes place, any more than just what are the chemical products causing rancidity. The only conclusion that one may draw is that the fats are first hydrolyzed or split up into glycerine and free fatty acids. This is followed by an oxidation of the products thus formed. Moisture, air, light, enzymes (organized ferments) and bacteria are all given as causes of rancidity. It seems very probable that the initial splitting of the fats is caused by enzymes, which are present in the seeds and fruits of the vegetable oils and tissue of animal fats, in the presence of moisture. Lewkowitsch strongly emphasizes this point and he is substantiated in his idea by other authorities. Others hold that bacteria or micro-organisms are the cause of this hydrolysis, citing the fact that they have isolated various micro-organisms from various fats and oils. The acceptance of the bacterial action would explain the various methods of preservation of oils and fats by the use of antiseptic preparations. It cannot, however, be accepted as a certainty that bacteria cause the rancidity of fats. The action of enzymes is a more probable explanation. The hydrolysis of fats and oils is accelerated when they are allowed to remain for some time in the presence of organic non-fats. Thus, palm oil, lower grades of olive oil, and tallow, which has been in contact with the animal tissue for a long time, all contain other nitrogenous matter and exhibit a larger percentage of free fatty acid than the oils and fats not containing such impurities. Granting this initial splitting of the fat into free fatty acids and glycerine, this is not a sufficient explanation. The products thus formed must be acted upon by air and light. It is by the action of these agents that there is a further action upon the products, and from this oxidation we ascertain by taste and smell (chemical means are still unable to define rancidity) whether or not a fat is rancid. While some authorities have presumed to isolate some of these products causing rancidity, we can only assume the presence of the various possible compounds produced by the action of air and light which include oxy fatty acids, lactones, alcohols, esters, aldehydes and other products. The soap manufacturer is interested in rancidity to the extent of the effect upon the finished soap. Rancid fats form darker soaps than fats in the neutral state, and very often carry with them the disagreeable odor of a rancid oil. Further, a rancid fat or oil is usually high in free acid. It is by no means true, however, that rancidity is a measure for acidity, for as has already been pointed out, an oil may be rancid and not high in free acid. The percentage of free fatty acid is of even greater importance in the soap industry. The amount of glycerine yield is dependent upon the percentage of free fatty acid and is one of the criterions of a good fat or oil for soap stock. PREVENTION OF RANCIDITY. Since moisture, air, light and enzymes, produced by the presence of organic impurities, are necessary for the rancidity of a fat or oil, the methods of preventing rancidity are given. Complete dryness, complete purification of fats and oils and storage without access of air or light are desirable. Simple as these means may seem, they can only be approximated in practice. The most difficult problem is the removal of the last trace of moisture. Impurities may be lessened very often by the use of greater care. In storing it is well to store in closed barrels or closed iron tanks away from light, as it has been observed that oils and fats in closed receptacles become rancid less rapidly than those in open ones, even though this method of storing is only partially attained. Preservatives are also used, but only in edible products, where their effectiveness is an open question. CHEMICAL CONSTANTS OF OILS AND FATS. Besides the various physical properties of oils and fats, such as color, specific gravity, melting point, solubility, etc., they may be distinguished chemically by a number of chemical constants. These are the iodine number, the acetyl value, saponification number, Reichert-Meissl number for volatile acids, Hehner number for insoluble acids. These constants, while they vary somewhat with any particular oil or fat, are more applicable to the edible products and are criterions where any adulteration of fat or oil is suspected. The methods of carrying out the analyses of oils and fats to obtain these constants are given in the various texts[2] on oils and fats, and inasmuch as they are not of great importance to the soap industry they are merely mentioned here. OIL HARDENING OR HYDROGENATING. It is very well known that oils and fats vary in consistency and hardness, depending upon the glycerides forming same. Olein, a combination of oleic acid and glycerine, as well as oleic acid itself largely forms the liquid portion of oils and fats. Oleic acid (C_{18}H_{34}O_{2}) is an unsaturated acid and differs from stearic acid (C_{18}H_{36}O_{2}), the acid forming the hard firm portion of oils and fats, by containing two atoms of hydrogen less in the molecule. Theoretically it should be a simple matter to introduce two atoms of hydrogen into oleic acid or olein, and by this mere addition convert liquid oleic acid and olein into solid stearic acid and stearine. For years this was attempted and all attempts to apply the well known methods of reduction (addition of hydrogen) in organic chemistry, such as treatment with tin and acid, sodium amalgam, etc., were unsuccessful. In recent years, however, it has been discovered that in the presence of a catalyzer, nickel in finely divided form or the oxides of nickel are usually employed, the process of hydrogenating an oil is readily attained upon a practical basis. The introduction of hardened oils has opened a new source of raw material for the soap manufacturer in that it is now possible to use oils in soap making which were formerly discarded because of their undesirable odors. Thus fish or train oils which had up to the time of oil hydrogenating resisted all attempts of being permanently deodorized, can now be employed very satisfactorily for soap manufacture. A Japanese chemist, Tsujimoto[3] has shown that fish oils contain an unsaturated acid of the composition C_{18}H_{28}O_{2}, for which he proposed the name clupanodonic acid. By the catalytic hardening of train oils this acid passes to stearic acid and the problem of deodorizing these oils is solved.[4] At first the introduction of hardened oils for soap manufacture met with numerous objections, due to the continual failures of obtaining a satisfactory product by the use of same. Various attempts have now shown that these oils, particularly hardened train oils, produce extraordinarily useful materials for soap making. These replace expensive tallow and other high melting oils. It is of course impossible to employ hardened oils alone, as a soap so hard would thus be obtained that it would be difficultly soluble in water and possess very little lathering quality. By the addition of 20-25% of tallow oil or some other oil forming a soft soap a very suitable soap for household use may be obtained. Ribot[5] discusses this matter fully. Hardened oils readily saponify, may be perfumed without any objections and do not impart any fishy odor to an article washed with same. Meyerheim[6] states that through the use of hydrogenated oils the hardness of soap is extraordinarily raised, so that soap made from hardened cottonseed oil is twelve times as hard as the soap made from ordinary cottonseed oil. This soap is also said to no longer spot yellow upon aging, and as a consequence of its hardness, is able to contain a considerably higher content of rosin through which lathering power and odor may be improved. Hardened oils can easily be used for toilet soap bases, provided they are not added in too great a percentage. The use of hardened oils is not yet general, but there is little doubt that the introduction of this process goes a long way toward solving the problem of cheaper soap material for the soap making industry. GREASE. Grease varies so greatly in composition and consistency that it can hardly be classed as a distinctive oil or fat. It is obtained from refuse, bones, hides, etc., and while it contains the same constituents as tallow, the olein content is considerably greater, which causes it to be more liquid in composition. Grease differs in color from an off-white to a dark brown. The better qualities are employed in the manufacture of laundry and chip soap, while the poorer qualities are only fit for the cheapest of soaps used in scrubbing floors and such purposes. There is usually found in grease a considerable amount of gluey matter, lime and water. The percentage of free fatty acid is generally high. The darker grades of grease are bleached before being used. This is done by adding a small quantity of sodium nitrate to the melted grease and agitating, then removing the excess saltpeter by decomposing with sulphuric acid. A better method of refining, however, is by distillation. The chrome bleach is also applicable. ROSIN (COLOPHONY, YELLOW ROSIN, RESINA). Rosin is the residue which remains after the distillation of turpentine from the various species of pines. The chief source of supply is in the States of Georgia North and South Carolina. It is a transparent, amber colored hard pulverizable resin. The better grades are light in color and known as water white (w. w.) and window glass (w. g.). These are obtained from a tree which has been tapped for the first year. As the same trees are tapped from year to year, the product becomes deeper and darker in color until it becomes almost black. The constituents of rosin are chiefly (80-90%) abietic acid or its anhydride together with pinic and sylvic acids. Its specific gravity is 1.07-1.08, melting point about 152.5 C., and it is soluble in alcohol, ether, benzine, carbon disulfide, oils, alkalis and acetic acid. The main use of rosin, outside of the production of varnishes, is in the production of laundry soaps, although a slight percentage acts as a binder and fixative for perfumes in toilet soaps and adds to their detergent properties. Since it is mainly composed of acids, it readily unites with alkaline carbonates, though the saponification is not quite complete and the last portion must be completed through the use of caustic hydrates, unless an excess of 10% carbonate over the theoretical amount is used. A lye of 20° B. is best adapted to the saponification of rosin when caustic hydrates are employed for this purpose, since weak lyes cause frothing. While it is sometimes considered that rosin is an adulterant for soap, this is hardly justifiable, as it adds to the cleansing properties of soap. Soaps containing rosin are of the well known yellowish color common to ordinary laundry soaps. The price of rosin has so risen in the last few years that it presents a problem of cost to the soap manufacturer considering the price at which laundry soaps are sold. ROSIN SAPONIFICATION. As has been stated, rosin may be saponified by the use of alkaline carbonates. On account of the possibility of the soap frothing over, the kettle in which the operation takes place should be set flush with the floor, which ought to be constructed of cement. The kettle itself is an open one with round bottom, equipped with an open steam coil and skimmer pipe, and the open portion is protected by a semi-circular rail. A powerful grid, having a 3-inch mesh, covers one-half of the kettle, the sharp edges protruding upwards. The staves from the rosin casks are removed at the edge of the kettle, the rosin placed on the grid and beaten through with a hammer to break it up into small pieces. To saponify a ton of rosin there are required 200 lbs. soda ash, 1,600 lbs. water and 100 lbs. salt. Half the water is run into the kettle, boiled, and then the soda ash and half the salt added. The rosin is now added through the grid and the mixture thoroughly boiled. As carbon dioxide is evolved by the reaction the boiling is continued for one hour to remove any excess of this gas. A portion of the salt is gradually added to grain the soap well and to keep the mass in such condition as to favor the evolution of gas. The remainder of the water is added to close the soap and boiling continued for one or two hours longer. At this point the kettle must be carefully watched or it will boil over through the further escape of carbon dioxide being hindered. The mass, being in a frothy condition, will rapidly settle by controlling the flow of steam. The remaining salt is then scattered in and the soap allowed to settle for two hours or longer. The lyes are then drained off the top. If the rosin soap is required for toilet soaps, it is grained a second time. The soap is now boiled with the water caused by the condensation of the steam, which changes it to a half grained soap suitable for pumping. A soap thus made contains free soda ash 0.15% or less, free rosin about 15%. The mass is then pumped to the kettle containing the soap to which it is to be added at the proper stage. The time consumed in thus saponifying rosin is about five hours. NAPHTHENIC ACIDS. The naphtha or crude petroleum of the various provinces in Europe, as Russia, Galacia, Alsace and Roumania yield a series of bodies of acid character upon refining which are designated under the general name of naphthenic acids. These acids are retained in solution in the alkaline lyes during the distillation of the naphtha in the form of alkaline naphthenates. Upon adding dilute sulphuric acid to these lyes the naphthenates are decomposed and the naphthenic acids float to the surface in an oily layer of characteristic disagreeable odor and varying from yellow to brown in color[7]. In Russia particularly large quantities of these acids are employed in the manufacture of soap. The soaps formed from naphthenic acids have recently been investigated[8] and found to resemble the soaps made from cocoanut oil and palm kernel oil, in that they are difficult to salt out and dissociate very slightly with water. The latter property makes them valuable in textile industries when a mild soap is required as a detergent, e. g., in the silk industry. These soaps also possess a high solvent power for mineral oils and emulsify very readily. The mean molecular weight of naphthenic acids themselves is very near that of the fatty acids contained in cocoanut oil, and like those of cocoanut oil a portion of the separated acids are volatile with steam. The iodine number indicates a small content of unsaturated acids. That naphthenic acids are a valuable soap material is now recognized, but except in Russia the soap is not manufactured to any extent at the present time. ALKALIS. The common alkali metals which enter into the formation of soap are sodium and potassium. The hydroxides of these metals are usually used, except in the so called carbonate saponification of free fatty acids in which case sodium and potassium carbonate are used. A water solution of the caustic alkalis is known as lye, and it is as lyes of various strengths that they are added to oils and fats to form soap. The density or weight of a lye is considerably greater than that of water, depending upon the amount of alkali dissolved, and its weight is usually determined by a hydrometer. This instrument is graduated by a standardized scale, and while all hydrometers should read alike in a liquid of known specific gravity, this is generally not the case, so that it is advisable to check a new hydrometer for accurate work against one of known accuracy. In this country the Baumé scale has been adopted, while in England a different graduation known as the Twaddle scale is used. The strength of a lye or any solution is determined by the distance the instrument sinks into the solution, and we speak of the strength of a solution as so many degrees Baumé or Twaddle which are read to the point where the meniscus of the lye comes on the graduated scale. Hydrometers are graduated differently for liquids of different weights. In the testing of lyes one which is graduated from 0° to 50° B. is usually employed. _Caustic soda_ is received by the consumer in iron drums weighing approximately 700 lbs. each. The various grades are designated as 60, 70, 74, 76 and 77%. These percentages refer to the percentage of sodium oxide (Na_{2}O) in 100 parts of pure caustic soda formed by the combination of 77-1/2 parts of sodium oxide and 22-1/2 parts of water, 77-1/2% being chemically pure caustic soda. There are generally impurities present in commercial caustic soda. These consist of sodium carbonate, sodium chloride or common salt and sometimes lime. It is manufactured by treating sodium carbonate in an iron vessel with calcium hydroxide or slaked lime, or by electrolysis of common salt. The latter process has yet been unable to compete with the former in price. Formerly all the caustic soda used in soap making was imported, and it was only through the American manufacturer using a similar container to that used by foreign manufacturers that they were able to introduce their product. This prejudice has now been entirely overcome and most of the caustic soda used in this country is manufactured here. CAUSTIC POTASH. The output of the salts containing potassium is controlled almost entirely by Germany. Formerly the chief source of supply of potassium compounds was from the burned ashes of plants, but about fifty years ago the inexhaustible salt mines of Stassfurt, Germany, were discovered. The salt there mined contains, besides the chlorides and sulphates of sodium, magnesium, calcium and other salts, considerable quantities of potassium chloride, and the Stassfurt mines at present are practically the entire source of all potassium compounds, in spite of the fact that other localities have been sought to produce these compounds on a commercial basis, especially by the United States government. After separating the potassium chloride from the magnesium chloride and other substances found in Stassfurt salts the methods of manufacture of caustic potash are identical to those of caustic soda. In this case, however, domestic electrolytic caustic potash may be purchased cheaper than the imported product and it gives results equal to those obtained by the use of the imported article, opinions to the contrary among soap makers being many. Most of the caustic potash in the United States is manufactured at Niagara Falls by the Niagara Alkali Co., and the Hooker Electrochemical Co., chlorine being obtained as a by-product. The latter concern employs the Townsend Cell, for the manufacture of electrolytic potash, and are said to have a capacity for making 64 tons of alkali daily. Since the molecular weight of caustic potash (56) is greater than that of caustic soda (40) more potash is required to saponify a pound of fat. The resulting potash soap is correspondingly heavier than a soda soap. When salt is added to a potassium soap double decomposition occurs, the potassium soap being transformed to a sodium soap and the potassium uniting with the chlorine to form potassium chloride. This was one of the earliest methods of making a hard soap, especially in Germany, where potash was derived from leeching ashes of burned wood and plants. SODIUM CARBONATE (SODA ASH). While carbonate of soda is widely distributed in nature the source of supply is entirely dependent upon the manufactured product. Its uses are many, but it is especially important to the soap industry in the so called carbonate saponification of free fatty acids, as a constituent of soap powders, in the neutralization of glycerine lyes and as a filler for laundry soaps. The old French Le Blanc soda process, which consists in treating common salt with sulphuric acid and reducing the sodium sulphate (salt cake) thus formed with carbon in the form of charcoal or coke to sodium sulphide, which when treated with calcium carbonate yields a mixture of calcium sulphide and sodium carbonate (black ash) from which the carbonate is dissolved by water, has been replaced by the more recent Solvay ammonia soda process. Even though there is a considerable loss of salt and the by-product calcium chloride produced by this process is only partially used up as a drying agent, and for refrigerating purposes, the Le Blanc process cannot compete with the Solvay process, so that the time is not far distant when the former will be considered a chemical curiosity. In the Solvay method of manufacture sodium chloride (common salt) and ammonium bicarbonate are mixed in solution. Double decomposition occurs with the formation of ammonium chloride and sodium bicarbonate. The latter salt is comparatively difficultly soluble in water and crystallizes out, the ammonium chloride remaining in solution. When the sodium bicarbonate is heated it yields sodium carbonate, carbon dioxide and water; the carbon dioxide is passed into ammonia which is set free from the ammonium chloride obtained as above by treatment with lime (calcium oxide) calcium chloride being the by-product. Sal soda or washing soda is obtained by recrystallizing a solution of soda ash in water. Large crystals of sal soda containing but 37% sodium carbonate are formed. POTASSIUM CARBONATE. Potassium carbonate is not extensively used in the manufacture of soap. It may be used in the forming of soft soaps by uniting it with free fatty acids. The methods of manufacture are the same as for sodium carbonate, although a much larger quantity of potassium carbonate than carbonate of soda is obtained from burned plant ashes. Purified potassium carbonate is known as _pearl ash_. ADDITIONAL MATERIAL USED IN SOAP MAKING. Water is indispensable to the soap manufacturer. In the soap factory _hard_ water is often the cause of much trouble. Water, which is the best solvent known, in passing through the crevices of rocks dissolves some of the constituents of these, and the water is known as hard. This hardness is of two kinds, _temporary_ and _permanent_. Temporarily hard water is formed by water, which contains carbonic acid, dissolving a portion of calcium carbonate or carbonate of lime. Upon boiling, the carbonic acid is driven from the water and the carbonate, being insoluble in carbon dioxide free water, is deposited. This is the cause of boiler scale, and to check this a small amount of sal ammoniac may be added to the water, which converts the carbonate into soluble calcium chloride and volatile ammonium carbonate. Permanent hardness is caused by calcium sulphate which is soluble in 400 parts of water and cannot be removed by boiling. The presence of these salts in water form insoluble lime soaps which act as inert bodies as far as their value for the common use of soap is concerned. Where the percentage of lime in water is large this should be removed. A method generally used is to add about 5% of 20° B. sodium silicate to the hard water. This precipitates the lime and the water is then sufficiently pure to use. _Salt_, known as sodium chloride, is used to a large extent in soap making for "salting out" the soap during saponification, as well as graining soaps. Soap ordinarily soluble in water is insoluble in a salt solution, use of which is made by adding salt to the soap which goes into solution and throws any soap dissolved in the lyes out of solution. Salt may contain magnesium and calcium chlorides, which of course are undesirable in large amounts. The products on the market, however, are satisfactory, thus no detail is necessary. _Filling materials_ used are sodium silicate, or water glass, talc, silex, pumice, starch, borax, tripoli, etc. Besides these other materials are used in the refining of the oils and fats, and glycerine recovery, such as Fuller's earth, bichromates of soda or potash, sulphate of alumina, sulphuric and hydrochloric acids and alcohol. A lengthy description of these substances is not given, as their modes of use are detailed elsewhere. FOOTNOTES: [1] Seifensieder Zeit, 1913, 40, p. 687, 724, 740. [2] Official Methods, see Bull. 107, A. O. A. C., U. S. Dept. Agricult. [3] Journ. Coll. of Engin. Tokyo Imper. Univ. (1906), p. 1. Abs. Chem. Revue f. d. Fett-u. Harz, Ind. 16, p. 84; 20, p. 8. [4] Meyerheim--Fort. der Chem., Physik. und Physik. Chem. (1913), 8. 6, p. 293-307. [5] Seifs. Ztg. (1913), 40, p. 142. [6] Loc. cit. [7] Les Matieres Graisses (1914), 7, 69, p. 3367. [8] Zeit. f. Angew. Chem. (1914), 27, 1, p. 2-4. CHAPTER II Construction and Equipment of a Soap Plant. No fixed plan for the construction and equipment of a soap plant can be given. The specifications for a soap factory to be erected or remodeled must suit the particular cases. Very often a building which was constructed for a purpose other than soap manufacture must be adapted for the production of soap. In either case it is a question of engineering and architecture, together with the knowledge obtained in practice and the final decision as to the arrangement is best solved by a conference with those skilled in each of these branches. An ideal soap plant is one in which the process of soap making, from the melting out of the stock to the packing and shipping of the finished product, moves downward from floor to floor, since by this method it is possible to utilize gravitation rather than pumping liquid fats and fluid soaps. Convenience and economy are obtained by such an arrangement. The various machinery and other equipment for soap manufacture are well known to those connected with this industry. It varies, of course, depending upon the kind of soap to be manufactured, and full descriptions of the necessary machinery are best given in the catalogs issued by the manufacturers of such equipment, who in this country are most reliable. To know just what equipment is necessary can very easily be described by a brief outline of the process various soaps undergo to produce the finished article. After the saponification has taken place in the _soap kettle_ the molten soap is run directly into the soap _frames_, which consist of an oblong compartment, holding anywhere from 400 to 1,200 pounds, with removable steel sides and mounted upon trucks, in which it solidifies. In most cases it is advisable to first run the soap into a _crutcher_ or mixer which produces a more homogeneous mass than if this operation is omitted. Color and perfume may also be added at this point, although when a better grade of perfume is added it must be remembered that there is considerable loss due to volatilization of same. When a _drying machine_ is employed the molten soap is run directly upon the rollers of this machine, later adding about 1.0% zinc oxide to the soap from which it passes continuously through the drying chamber and is emitted in chip form ready for milling. After the soap has been framed, it is allowed to cool and solidify, which takes several days, and then the sides of the frame are stripped off. The large solid cake is cut with wires by hand or by a _slabber_ into slabs of any desired size. These slabs are further divided into smaller divisions by the _cutting table_. In non-milled soaps (laundry soaps, floating soaps, etc.), these are pressed at this stage, usually by automatic presses, after a thin hard film has been formed over the cake by allowing it to dry slightly. In making these soaps they are not touched by hand at any time during the operation, the pressing, wrapping and packing all being done by machinery. For a milled soap the large slabs are cut into narrow oblong shapes by means of the cutting table to readily pass into the feeder of the _chipper_, the chips being spread upon _trays_ and dried in a _dry house_ until the moisture content is approximately 15%. The process of milling is accomplished by passing the dried soap chips through a _soap mill_, which is a machine consisting of usually three or four contiguous, smooth, granite rollers operated by a system of gears and set far enough apart to allow the soap to pass from a hopper to the first roller, from which it is constantly conveyed to each succeeding roller as a thin film, and finally scraped from the last roller to fall into the _milling box_ in thin ribbon form. These mills are often operated in tandem, which necessitates less handling of soap by the operator. The object of milling is to give the soap a glossy, smooth finish and to blend it into a homogeneous mass. The perfume, color, medication or any other material desired are added to the dried soap chips prior to milling. Some manufacturers use an _amalgamator_ to distribute these uniformly through the soap, which eliminates at least one milling. When a white soap is being put through the mill, it is advisable to add from 0.5% to 1% of a good, fine quality of zinc oxide to the soap, if this substance has not been previously added. This serves to remove the yellowish cast and any translucency occasioned by plodding. Too great a quantity of this compound added, later exhibits itself by imparting to the soap a dead white appearance. Inasmuch as the milling process is one upon which the appearance of a finished cake of toilet soap largely depends, it should be carefully done. The number of times a soap should be milled depends upon the character of a soap being worked. It should of course be the object to mill with as high a percentage of moisture as possible. Should the soap become too dry it is advisable to add water directly, rather than wet soap, since water can more easily be distributed through the mass. As a general statement it may be said it is better policy to overmill a soap, rather than not mill it often enough. After the soap has been thoroughly milled it is ready for plodding. A _plodder_ is so constructed as to take the soap ribbons fed into the hopper by means of a worm screw and continuously force it under great pressure through a jacketed cylinder through which cold water circulates in the rear to compensate the heat produced by friction and hot water at the front, to soften and polish the soap which passes out in solid form in bars of any shape and size depending upon the form of the _shaping plate_ through which it is emitted. The bars run upon a _roller board_, are cut into the required length by a special _cake cutting table_, allowed to dry slightly and pressed either automatically or by a foot power _press_ in any suitable soap _die_. The finished cake is then ready for wrapping and after due time in stock reaches the consumer. Besides the various apparatus mentioned above there are many other parts for the full equipment of a modern soap plant, such as remelters, pumps, mixers, special tanks, power equipment, etc. As has been stated, however, practical experience will aid in judging the practicability as to installation of these. The various methods of powdering soap are, however, not generally known. Where a coarse powder is to be produced, such as is used for common washing powders, no great difficulty is experienced with the well known Blanchard mill. In grinding soap to an impalpable powder the difficulties increase. The methods adapted in pulverizing soaps are by means of disintegrators, pebble mills and chaser mills. The disintegrator grinds by the principle of attrition, that is, the material is reduced by the particles being caused to beat against each other at great velocity; a pebble mill crushes the substance by rubbing it between hard pebbles in a slowly revolving cylinder; the chaser mill first grinds the material and then floats it as a very fine powder above a curb of fixed height. The last method is particularly adapted for the finest of powder (140 mesh and over). CHAPTER III Classification of Soap-Making Methods. In the saponification of fats and oils to form soap through the agency of caustic alkalis, as has been stated, the sodium or potassium salts of the mixed fatty acids are formed. Sodium soaps are usually termed hard soaps, and potassium soaps soft. There are, however, a great many varieties of soaps the appearance and properties of which depend upon their method of manufacture and the oils or fats used therein. The various methods adopted in soap making may be thus classified: 1. Boiling the fats and oils in open kettles by open steam with indefinite quantities of caustic alkali solutions until the finished soap is obtained; ordinarily named _full boiled soaps_. These may be sub-divided into (a) hard soaps with sodium hydrate as a base, in which the glycerine is recovered from the spent lyes; (b) hard soaps with soda as a base, in which the glycerine remains in the soap, e. g., marine cocoanut oil soaps; (c) soft potash soaps, in which the glycerine is retained by the soap. 2. Combining the required amount of lye for complete saponification of a fat therewith, heating slightly with dry heat and then allowing the saponification to complete itself. This is known as the _cold process_. 3. Utilizing the fatty acid, instead of the neutral fat, and combining it directly with caustic alkali or carbonate, which is incorrectly termed _carbonate saponification_, since it is merely neutralizing the free fatty acid and thus is not a saponification in the true sense of the word. No glycerine is directly obtained by this method, as it is usually previously removed in the clearage of the fat by either the Twitchell or autoclave saponification method. In the methods thus outlined the one most generally employed is the full boiled process to form a sodium soap. This method of making soap requires close attention and a knowledge which can only be obtained by constant practice. The stock, strength of lyes, heat, amount of salt or brine added, time of settling, etc., are all influencing factors. The principles involved in this process are briefly these: The fat is partly saponified with weak lyes (usually those obtained from a previous boiling in the strengthening change are used), and salt is added to grain the soap. The mass is then allowed to settle into two layers. The upper layer is partly saponified fat; the lower layer, or spent lye, is a solution of salt, glycerine, and contains any albuminous matter or any other impurity contained in the fat. This is known as the _killing_ or glycerine change. Strong lyes are now added and the fat entirely saponified, which is termed the _strengthening change_. The mass is then allowed to settle and the fluid soap run off above the "nigre." This operation is called the finish or _finishing_ change. The method may be more fully illustrated by a concrete example of the method of manufacture of a tallow base: Charge-- Tallow 88 per cent. Cocoanut oil 10 per cent. Rosin w. w. 2 per cent. Amount charge 10 tons About five tons of tallow and one ton of cocoanut oil are pumped or run into the soap kettle and brought to a boil with wet steam until it briskly comes through the hot fat. The caustic soda (strengthening lyes from former boilings may be used here) is gradually added by the distributing pipe, any tendency to thicken being checked by the introduction of small quantities of brine ("salt pickle"). If the lye is added too rapidly the soap assumes a granular appearance, indicating that the addition of same must be discontinued. Water should then be added and the mass boiled through until it again closes. When the addition of the proper amount of caustic soda is nearing its completion the soap gradually thins. The steam is now cut down to about one turn of the valve, and brine is rapidly added or salt shoveled in. In ten to fifteen minutes the steam again breaks through and, from the appearance of the soap, it can be seen whether sufficient brine has been added. A sample taken out by means of a long wooden paddle should show the soap in fine grains with the lyes running from it clear. The steam is then shut off and the soap allowed to settle from one and one-half to two hours. In all settlings the longer time this operation is permitted to continue, the better will the subsequent operations proceed. The mixture now consists of a partly saponified layer of fat above the spent lyes. The lyes are drawn off until soap makes its appearance at the exit pipe. The valve is then closed and the soap blown back into the kettle by steam. The lyes thus obtained are known as _spent lyes_, from which the glycerine is recovered. They should show an alkalinity of approximately 0.5 per cent. if the operation is carefully carried out. The remaining tallow is now added and the above operations repeated. After the spent lyes have been drawn off, the soap is closed with water and the proper percentage of rosin soap previously formed, or rosin itself is added to the mass in the kettle. More lye is then allowed to flow in until the mixture is up to "strength." This is usually tested by the "bite" on the tongue of a small cooled sample. After boiling until the steam comes through, the mass is grained with salt as before and allowed to settle one and one-half to three hours. These lyes, known as _strengthening lyes_ are run to storage to be used subsequently with fresh fat to take up the caustic soda contained therein. The soap is now ready for finishing and is first boiled through and tried for strength. A drop of phenolphthalein (1 per cent. phenolphthalein in 98 per cent. alcohol) is allowed to drop on the molten soap taken up on a trowel. The red color should be instantly produced and develop to a full deep crimson in a few seconds, or more lye must be added until this condition is realized. Should it flash a deep crimson immediately it is on the strong side. This cannot be conveniently remedied; it can only serve as a guide for the next boil, but in any case it is not of any serious consequence, unless it is too strong. With the steam on, the soap is now examined with a trowel which must be thoroughly heated by working it about under the surface of the hot soap. The appearance of the soap as it runs from the face of the trowel indicates its condition. It is not possible to absolutely describe the effect, which can only be properly judged by practice, yet the following points may serve as a guide. The indications to be noticed are the shape and size of the flakes of soap as the sample on the trowel breaks up and runs from the hot iron surface, when the latter is turned in a vertical position, as well as the condition of the iron surface from which the soap flakes have fallen. A closed soap will run slowly into a homogeneous sheet, leaving the trowel's surface covered with a thin layer of transparent soap; a grained mass will run rapidly down in tiny grains, about one-half an inch in diameter or less, leaving the hot trowel absolutely dry. The object of the finish is to separate the soaps of the lower fatty acids from those of the higher, and both from excess of liquid. A point midway between "open" and "closed" is required to arrive at this point. Having arrived at the above condition, the soap is allowed to settle anywhere from one to three days and then run off through the skimmer pipes to the nigre and framed or pumped to the tank feeding the drying machine. The stock thus obtained should be fairly white, depending upon the grade of tallow used and slightly alkaline to an alcoholic phenolphthalein solution. If removed at exactly the neutral point or with a content of free fat the soap will sooner or later develop rancidity. The soap thus obtained is an ordinary tallow base, and the one by far greatest used in the manufacture of toilet soaps. The percentage of cocoanut oil indicated is not fixed and may readily be varied, while in fine toilet soap the rosin is usually eliminated. In the manufacture of full boiled soda soaps in which no glycerine is obtained as a by-product, it being retained in the soap itself, the soap formed is known as a "run" soap. The process is used most extensively in the manufacture of marine soaps by which the method may be best illustrated. This soap is known as marine soap because of its property of readily forming a lather with salt water and is mostly consumed aboard vessels. Marine soaps are manufactured by first placing in the kettle a calculated amount of lye of 25 deg. to 35 deg. B., depending upon the amount of moisture desired in the finished soaps, plus a slight excess required to saponify a known weight of cocoanut oil. With open steam on, the cocoanut oil is then gradually added, care being taken that the soap does not froth over. Saponification takes place readily and when the oil is entirely saponified the finished soap is put through the process known as running. This consists in constantly pumping the mass from the skimmer pipe back into the top of the kettle, the object being to prevent any settling of the nigre or lye from the soap, as well as producing a homogeneous mass. It is customary to begin the saponification in the morning, which should be completed by noon. The soap is then run for about three hours and framed the next morning. After having remained in the frame the time required to solidify and cool, the soap is slabbed and cut into cakes. This process is difficult to carry out properly, and one not greatly employed, although large quantities of marine soap are purchased by the government for use in the navy and must fulfill certain specifications required by the purchasing department. In making potash soaps it is practically impossible to obtain any glycerine directly because of the pasty consistency of the soap, and no graining is possible because the addition of salt to a soft soap, as already explained, would form a soda soap. Large quantities of soft soaps are required for the textile industries who desire mostly a strong potash soap, and the large number of automobiles in use at the present time has opened a field for the use of a soft soap for washing these. A soap for this purpose must be neutral so as not to affect the varnish or paint of automobiles. A suitable soap for textile purposes may be made as follows: Red oil 80 parts House grease 20 parts Caustic soda lye, 36 degs. B. 3 parts Carbonate of potash 5-1/2 parts Caustic potash 23-1/4 parts Olive oil, corn oil, soya bean oil, olive oil foots or cottonseed oil may replace any of the above oils. A large quantity of cottonseed oil will cause the soap to fig. To carry out the process, the caustic potash and carbonate of potash are dissolved and placed in the kettle together with the soda lye, and the oils added. This is most satisfactorily accomplished by being finished the day before the boiling is begun. The next day the boiling is begun and water added to bring the soap up to the desired percentage of fatty acid, due allowance being made for the water formed by the condensation of the open steam in boiling. Care must be taken that the soap in the kettle does not swell and run over during the saponification. A good procedure is to use open steam for a period of about two hours, then close the valve and allow the saponification to continue without boiling, and repeat this until it is entirely saponified. After the saponification has been completed the soap is briskly boiled all day and the proper corrections made; that is, if too alkaline, more oil is added, and if free fat is present, more potash. About 2 per cent. carbonate of potash is the proper amount for a soap containing 50 per cent. fatty acid. The soap is sampled by allowing it to drop on a clean, cold glass surface. In so doing, the soap should not slide or slip over the glass surface when pressed thereon, but should adhere to the glass, or it is too alkaline. A sample worked between the fingers showing too much stringiness should have more strong potash and oil added. A sample taken out in a pail and allowed to cool over night will serve as a guide as to the body of the soap in the kettle. When the soap has thus been properly finished it is run into barrels. For an automobile soap the following is a good working formula: Corn oil 1,000 parts Potash lye, 31-1/2 degs. B. 697 parts Proceed as in the directions just given for textile soap in placing charge in the kettle. When the kettle is boiling up well, shut off the steam and the saponification will complete itself. The soap may be run into the barrels the next day. A heavy soap with a smaller percentage of fat may be made as follows: Corn oil 1,000 parts Potash lye, 24-1/2 degs. B. 900 parts Boil until the soap bunches, and shovel the finished soap into barrels. Upon standing it will clear up. By the addition of more water the yield of soap per pound of oil may be run up to 300 per cent. After soft soaps have been allowed to stand for some time the phenomenon known as "figging" often occurs. This term is applied to a crystalline-like formation, causing spots of a star-like shape throughout the soap. This is undoubtedly due to the stearine content of the soap crystallizing out as it cools, and forming these peculiarly-shaped spots. It more generally occurs in the winter and may be produced artificially by adding a small quantity of soda to the potash lye before saponification. The oils usually employed in the manufacture of potash soaps are cottonseed oil, corn oil, soya bean oil, olive oil foots, red oil, cocoanut oil, grease and the various train oils. The usual percentage yield is from 225 per cent. to 300 per cent., based upon the weight of oil used. In calculating the weight of a soft soap it is to be remembered that since potassium has a higher molecular weight (56) than sodium (40), the corresponding soap formed is that much greater in weight when compared with a sodium soap. Rosin may be added to soft soaps as a cheapening agent. COLD PROCESS. The cold process for manufacturing soap is the simplest method of soap making, and the equipment required is small when compared to the other methods. All the more expensive equipment that is necessary is a crutcher, a tank to hold the lye, frames, a slabber or cutting table, and a press. Yet, in spite of the simplicity of thus making soap, the disadvantages are numerous for the production of a good piece of soap. The greatest difficulty is to obtain a thorough combination of oil or fat and lye so that there will not be an excess of one or the other in the finished soap. At its best there is either a considerable excess of free fat which later exhibits itself in producing rancidity or uncombined caustic, which produces an unpleasant effect on the skin when the soap is consumed for washing. The latter objection, of course, can only be applied to toilet soaps. Cocoanut oil is used very largely in the manufacture of cold-made soaps as it is well adapted for this purpose, although it is by no means true that other oils may not be employed. Since by this process of manufacture no impurity contained in the fat or oil is removed in the making of the soap, it is necessary that in order to obtain a fine finished product, any impurity contained in these may be removed if present, or that the fats be as pure as can be obtained. If inedible tallow is used for cold-made soap, it is advisable to bleach it by the Fuller's Earth Process. The carrying out of this method is best illustrated by an example of a cold-made cocoanut oil soap. Charge: Cochin cocoanut oil 846 parts Lye (soda), 35 degs. B. 470 parts Water 24 parts The oil is run into the crutcher and the temperature of the oil raised to 100 degs. F. by dry steam. The lye and water are at room temperature. After all the oil is in the crutcher, the lye and water are slowly added to prevent any graining of the soap. Toward the end the lye may be added more rapidly. When all the lye is in, the mass is crutched for about three hours, or until upon stopping the crutcher a finger drawn over the surface of the soap leaves an impression. If this condition is not realized, the soap must be mixed until such is the case. Having arrived at this point, the mixture is dropped into a frame which should remain uncovered. The heat produced by the further spontaneous saponification will cause the soap to rise in the middle of the frame. After having set for some days it is ready to be slabbed and cut into cakes. A potash soap may be made by the cold process just as readily as a soda soap. Soaps of this type may be made by either of these formulae in a crutcher: Olive oil foots 600 Potash lye, 18 degs. B. hot, 20 degs. B. cold 660 or Corn oil 800 Rosin 200 Potash lye, 27 degs. B. 790 Water 340 Heat the oils to 190 degs. F., add the lye and crutch until the soap begins to bunch, when it is ready to be run into barrels where the saponification will be completed. Semi-boiled soaps differ from those made by the cold process in temperature. In making semi-boiled soaps the fats are usually heated to 140° F. The addition of the lye raises the temperature to 180°--200° F. when saponification takes place. CARBONATE SAPONIFICATION. The method of the formation of soap by the utilization of the fatty acid directly, from which the glycerine has already been removed by some method of saponification other than with caustic soda, and neutralizing this with alkali, is becoming increasingly popular. The glycerine is more easily recovered from a previous cleavage of the fats or oils, but a soap made from the mixed fatty acids thus obtained is seldom white in color and retains an unpleasant odor. Since soda ash or sodium carbonate is cheaper than caustic soda and readily unites with a fatty acid, it is used as the alkali in the carbonate saponification. The process is similar to that already given under Rosin Saponification. About 19 per cent. by weight of the fatty acids employed of 58 per cent. soda ash is dissolved in water until it has a density of 30 degs. B., and the solution is run into the kettle, which is usually equipped with a removable agitator. The fatty acids, previously melted, are then slowly added while the mixture is boiled with open steam and agitated with the stirring device. The fatty acids instantly unite with the carbonate and rise in the kettle, due to the generation of carbon dioxide, and care must be exercised to prevent boiling over. After all the fatty acid has been added, and the mass is boiled through the saponification must be completed with caustic soda, as there is as yet no practical method known which will split a fat entirely into fatty acid and glycerine. Thus about 10 per cent. of the fatty acids are true neutral fats and require caustic soda for their saponification. This is then added and the soap completed, as in full-boiled soaps. In carrying out this method upon a large scale, large sue\Neanderthal\doroteer\Neanderthal\Josephine\ quantities of carbon dioxide are formed during the boiling of the soap, which replaces a quantity of the air contained therein. The kettle room should therefore be well ventilated, allowing for a large inflow of fresh air from out of doors. CHAPTER IV Classification of Soaps. In considering the many different varieties of soaps, their classification is purely an arbitrary one. No definite plan can be outlined for any particular brand to be manufactured nor can any very sharp distinction be drawn between the many soaps of different properties which are designated by various names. It is really a question to what use a soap is to be put, and at what price it may be sold. There is, of course, a difference in the appearance, form and color, and then there are soaps of special kinds, such as floating soaps, transparent soaps, liquid soaps, etc., yet in the ultimate sense they are closely allied, because they are all the same chemical compound, varying only in their being a potash or soda soap, and in the fatty acids which enter into combination with these alkalis. Thus we can take a combination of tallow and cocoanut oil and make a great many presumably different soaps by combining these substances with caustic soda, by different methods of manufacture and by incorporating various other ingredients, as air, to form a floating soap, alcohol to make a transparent soap, dyestuffs to give a different color, etc., but essentially it is the same definite compound. The manufacturer can best judge the brand of soaps he desires to manufacture, and much of his success depends upon the name, package, shape, color or perfume of a cake of soap. It is the consumer whom he must please and many of the large selling brands upon the market today owe their success to the above mentioned details. The great majority of consumers of soap know very little concerning soap, except the fact that it washes or has a pleasant odor or looks pretty, and the manufacturer of soap must study these phases of the subject even more carefully than the making of the soap itself. For a matter of convenience we will classify soap under three general divisions: I. Laundry soaps, including chip soaps, soap powders and scouring soaps. II. Toilet soaps, including floating soap, castile soap, liquid soap, shaving soap, etc. III. Textile soaps. LAUNDRY SOAP. The most popular household soap is laundry soap. A tremendous amount of this soap is consumed each day in this country, and it is by far manufactured in larger quantities than any other soap. It is also a soap which must be sold cheaper than any other soap that enters the home. The consumers of laundry soap have been educated to use a full boiled settled rosin soap and to make a good article at a price this method should be carried out, as it is the one most advisable to use. The composition of the fats entering into the soap depends upon the market price of these, and it is not advisable to keep to one formula in the manufacture of laundry soap, but rather to adjust the various fatty ingredients to obtain the desired results with the cheapest material that can be purchased. It is impossible to use a good grade of fats and make a profit upon laundry soap at the price at which it must be retailed. The manufacturer of this grade of soap must look to the by-product, glycerine, for his profit and he is fortunate indeed if he realizes the entire benefit of this and still produces a superior piece of laundry soap. SEMI-BOILED LAUNDRY SOAPS. It is advantageous at times to make a laundry soap by a method other than the full boiled settled soap procedure as previously outlined. This is especially the condition in making a naphtha soap, in which is incorporated naphtha, which is very volatile and some of the well known manufacturers of this class of soap have adopted this process entirely. A laundry soap containing rosin cannot be advantageously made by the cold process, as the soap thus made grains during saponification and drops a portion of the lye and filling materials. By making a semi-boiled soap this objection is overcome. The half boiled process differs from the cold process by uniting the fats and alkalis at a higher temperature. To carry out this process the following formulae have been found by experience to give satisfactory results. I. lbs. Tallow 100 Rosin 60 Soda Lye, 36° B. 80 II. Tallow 100 Rosin 60 Silicate of Soda 25 Soda Lye, 36° B. 85 III. Tallow 100 Rosin 100 Lye, 36° B. 105 Silicate of Soda 25 Sal Soda Solution 20 In any of these formulas the sodium silicate (40° B.) may be increased to the same proportion as the fats used. By so doing, however, twenty pounds of 36° B. lye must be added for every hundred pounds of silicate additional to that indicated or in other words, for every pound of silicate added 20 per cent. by weight of 36° B. lye must be put into the mixture. The rosin may also be replaced by a previously made rosin soap. To make a semi-boiled soap, using any of the above formulae, first melt the rosin with all or part of the fat, as rosin when melted alone readily decomposes. When the mixture is at 150° F. run it into the crutcher and add the lye. Turn on sufficient dry steam to keep the temperature of the soap at about 150° F. in the winter or 130° F. in summer. After the mass has been mixed for half an hour, by continuously crutching the soap it will at first thicken, then grain and it may again become thick before it becomes smooth. When the mass is perfectly smooth and homogeneous drop into a frame and crutch in the frame by hand to prevent streaking. After standing the required length of time the soap is finished into cakes as usual. SETTLED ROSIN SOAP. Settled rosin soaps are made from tallow, grease, cottonseed oil, bleached palm oils of the lower grades, corn oil, soya bean oil, arachis oil, distilled garbage grease, cottonseed foots or fatty acids together with an addition of rosin, varying from 24 per cent. to 60 per cent. of the fatty acids which should titer from 28 to 35. A titer lower than 28 will prevent the finished kettle of soap from being capable of later taking up the filling materials. As has already been stated under hardened oils, these being very much higher in titer allow a greater percentage of rosin to be added. Thus hardened fish oils and cottonseed oil are gradually being more extensively employed in soaps of this character. The procedure of handling the kettle is similar to that given under full boiled soap. The stock is steamed out into a settling tank and allowed to settle over night, after which it is pumped into the soap kettle. Having stocked the kettle, open steam is turned on and 10°-12° B. lye is run in, while using a steam pressure of ninety to one hundred pounds in order to prevent too great a quantity of condensation of the steam, the water thus being formed weakening the lye. If a steam pressure of fifty to sixty pounds is available, a stronger lye (20° B.) should be added. Care must be taken not to allow the lye to flow in too rapidly or the soap will not grain. The saponification is only attained by prolonged boiling with sufficient lye of proper strength. When saponification has taken place, the mass begins to clear and a sample taken out with a paddle and cooled should show a slight pink with a 1 per cent. alcoholic phenolphthalein solution. It may be stated here that in using this indicator or any other to test the alkalinity of soap, the soap should always be cooled and firm, as whenever water is present, the dissociation of the soap thereby will always react alkaline. When this state is reached the mass is ready for graining, which is accomplished by distributing salt brine or pickle or spreading dry salt over the surface of the soap. The kettle is then thoroughly boiled until the mass shows a soft curd and the lye drops clearly from a sample taken out with a trowel or paddle. The steam is then shut off and the soap allowed to settle over night. The lyes are then run off to the spent lye tank for glycerine recovery. In saponifying a freshly stocked kettle it is apt to bunch. To prevent this salt is added at various times to approximately one per cent. of the fat used. If, by any possibility the soap has bunched, this condition may be remedied by the addition of more strong lye and boiling until it is taken up. To work a kettle to its full capacity it is advisable to make two "killing" changes. First add about 75 per cent. of the fat and grain as directed. Run off the spent lyes and then add the remainder of the stock and repeat the process. When the spent lye has been run to storage, the open steam is again turned on and 18° B. lye gradually allowed to run in. The rosin is now broken up and put into the kettle, or a previously made rosin soap is pumped in. Lye is then added until the soap has a sharp taste after about three hours of continuous boiling, or when the soap is in the closed state. More lye should then be run into the kettle to grain the soap well, the grain not being too small. Then allow the soap to settle over night and draw off the strengthening lye. The next day again boil up the kettle and add water until the soap thins out and rises or swells high in the kettle. A sample taken out at this stage upon a hot trowel should run off in large flakes. The surface of the soap should be bright and shiny. If the sample clings to the trowel, a slight addition of lye will remedy this defect. The kettle is then allowed to rest, to drop the nigre and to cool for some time, depending upon the size of the kettle. The proper temperature is such that after having been pumped to the crutcher and the filling materials having been added, a thermometer placed into the mass should indicate 128°-135° F. after the crutcher has run from ten to fifteen minutes. The filling material may consist of from 7-9 per cent. of sal soda solution, 36°-37° B. warm or just enough to close up the soap and make it rise high in the center of a screw crutcher and make it cling close to a warm trowel. Other fillers such as outlined below are added at this point. An addition of from 2-3 per cent. of a special mineral oil for this purpose will impart a finish to the soap and 3-5 per cent. starch added prevents the soap from cracking in the frames. Other filling material as silicate of soda, borax, talc or silex are used. After the filling material has been thoroughly crutched through the soap it is framed, and, after being several days in the frame to solidify and cool the soap is ready for slabbing, pressing and wrapping. In order to more definitely illustrate the composition of the mixture of fats and oils entering into the formation of a laundry soap a typical formula may be given for such a soap containing 40 per cent. rosin added to the amount of fats used: lbs. Grease 7,000 Tallow 4,000 Corn Oil 7,000 Cottonseed Oil 3,000 Rosin 8,400 The following have been found to be satisfactory filling materials and are calculated upon the basis of a 1,400-pound frame of soap. I. lbs. Sodium Silicate, 38°-40° B. 100 Mineral Oil 25 Sal Soda Solution, 36° B. 80 Borax 1 II. Sal Soda Solution, 36° B. 80 Mineral Oil 25 Sodium Silicate 60 III. Soda Ash 10 Sal Soda 55 Sodium Silicate 115 Mineral Oil 40 Brine (Saturated Solution) 10 Sodium Silicate, 38°-40° B. 100 IV. Sodium Silicate 100 Silex or Talc 200 Soda Ash 50 V. Sal Soda Solution, 36° B. 90 Sodium Silicate 50-60 Mineral Oil 25 Borax Solution, 25° B. (hot) 15 CHIP SOAP. Chip soap is used extensively in laundries but is also used largely in other branches. It may be made either as a settled soap or by the cold made process. To make a full boiled settled chip soap, proceed as directed under settled laundry soap. The kettle is stocked with light grease or a mixture of grease with corn oil or other cheap oils. For this kind of soap the rosin is eliminated. Chip soap may be filled as well as laundry soap. This is done in the crutcher and the following adulterations are suitable. lbs. Settled Soap 700 Soda Ash 35 Sodium Silicate 215 or Settled Soap 700 Silicate of Soda 560 Soda Ash 18 Carbonate of Potash, 26° B. 50 The cheapest method of drying is by running this soap through a drying machine and this is the procedure usually carried out for making dried chip soap. COLD MADE CHIP SOAPS. To make chip soaps by the cold process a sweet tallow of low percentage of free fatty acid should be employed. The tallow is heated to 120° to 135° F. and the lye run in slowly at first and then the silicate of soda is added. The mass is then mixed until a finger drawn through the soap leaves a slight impression, then dropped into frames or barrels. Soaps containing a small percentage of fat should be well covered in the frame for twenty-four hours to retain their heat and insure proper saponification. The following formulae are suitable: I. lbs. Tallow 1,200 Soda Lye, 35° B. 850 Sodium Silicate 750 II. Tallow 475 Ceylon Cocoanut Oil 100 Soda Lye, 37° B. 325 Potash Lye, 37° B. 56 III. Tallow 500 Soda Lye, 37-1/2° B. 297 Sodium Silicate 416 Potash Lye, 37-1/2° B. 37-1/2 IV. Tallow 450 Soda Lye, 37-1/2° B. 255 Sodium Silicate 450 Potash Lye, 37-1/2° B. 50 V. Tallow 450 Soda Lye, 35° B. 470 Sodium Silicate 650 VI. Tallow 420 Sodium Silicate 600 Soda Lye, 37-12° B. 270 UNFILLED CHIP SOAP. A very good grade of chip soap is made by employing no filling material whatsoever, but unfortunately the price of this soap has been cut to such an extent that these can not compete with a filled chip. A number of the best soaps of this kind are made from a settled soap using a light grease with corn oil. A soap of this nature is made as follows. lbs. Settled Soap 800 Sal Soda Solution, 36°-37° B. 252 Soda Ash 182 If this soap is run into frames it may be stripped and chipped in two days. SOAP POWDERS. Soap powders have become so great a convenience as a general cleansing agent that to eliminate them from the household necessities would mean much unnecessary energy and work to the great number of consumers of this product. They may be manufactured so cheaply and still be efficient, that their use has almost become universal for cleansing and scouring purposes. The uses to which soap and scouring powders are adapted are too well known to enter into a description of their employment. Since they offer a greater profit to the manufacturer than ordinary household soap, many brands are extensively advertised. Numerous combinations for soap powders might be cited and it is a simple matter to vary the ingredients as to fat content and manufacture a powder of this sort as low as a cent a pound. Many substances are incorporated with soap, such as salt, soda ash, tripoli, crushed volcanic deposits, ground feldspar, infusorial earth of various kinds, silex, etc. In addition to these various fillers, compounds with true cleansing and bleaching properties, in addition to soap, are added, such as the salts of ammonium (sal ammoniac, carbonate of ammonia), sodium perborate and the peroxides of various metals. The public, however, have been accustomed to receive a large package of soap or scouring powder for a small amount of money and it is a difficult matter for the manufacturer to add more expensive substances of this nature to his product, to increase its efficiency, without raising the price or decreasing the size of the package. In manufacturing soap powders, the dried soap chips might be mixed with the filler and alkali and then pulverized. This method is not extensively employed nevertheless. The process which is the most economical is one whereby the ingredients are mixed in a specially adapted mixer for heavy material until dry and then run directly to the crusher and pulverizer, after which it is automatically packed, sealed and boxed. Another method of procedure is to run out the mixture from the crutcher to the frames, which are stripped before the soap cools, and is cut up at once, for if it hardens it could not be cut with wires. It is better, however, to run the mixture into sheets upon a specially constructed floor and break up the mass when cool. Formulae for soap powders which have been found to be suitable for running dry in the mixer follow: I Soda ash, 58 per cent. 42 lbs. Silica 220 " Settled soap (usually cottonseed). 25 " Salt 10 " II Soap (settled cottonseed) 40 lbs. Soda ash, 58 per cent. 60 " III Settled soap 100 lbs. Soda ash, 58 per cent. 400 " Fillers in varying proportions may replace the soda ash in the above formulae. It is of course understood that the soap has been previously made and run as molten soap into the crutcher. The following soap powders will not dry up in the crutcher upon running, but are of the class which may be framed or run on the floor to solidify: I Soap 850 lbs. Filler 400 " Sal soda solution, 20 degs. B 170 " II Soap 650 lbs. Filler 550 " Sal soda solution, 20 degs. B. 340 " III Soap 80 lbs. Filler 550 " Sal soda solution 170 " IV Soap (settled tallow) 800 lbs. Filler 400 " Sal soda solution 170 " Water 100 " V First saponify 100 parts house grease and 100 parts ordinary grease and make a run soap. Then use in crutcher either: Soap 400 lbs. Filler 575 " Hot water 60 " or Soap 200 lbs. Hot water 200 " Filler 625 " It would be a simple matter to write numerous additional formulae, but the above are typical. The manufacturer must judge for himself just what filling material to use. The filler indicated in the above formulae is therefore left open. A few formulae for more expensive powders than those given recently appeared among others in the "Seifensieder Zeitung"[9]: I Powdered soap 90 lbs. Sodium perborate 10 " The perborate should be added when the powder is perfectly dry or it loses its bleaching properties. II Soap powder, 20 per cent. fat. Cocoanut oil fatty acids 25 lbs. Olein 25 " Bone fat 70 " Soda lye, 30 degs. B. 90 " Water 150 " Ammonium carbonate 125 " III Soap powder, 10 per cent. fat. Cocoanut oil fatty acids 20 lbs. Olein 10 " Bone fat 20 " Soda lye, 30 degs. B. 30 " Water 175 " Ammonium carbonate 175 " LIGHT OR FLUFFY POWDERS. Light or fluffy powders containing 35-45% moisture can be made in two ways. The first method requiring a minimum equipment is to mix the powder and sal soda in a mixer, allow it to stand in frames for a week to crystallize or spread it on the floor for a few hours to dry and then grinding it. The continuous method finishes the powder in a few minutes and with a minimum amount of labor. By this process the various ingredients, soap, soda ash solution, etc., are measured, run by gravity into the mixer, mixed and the molten mass run over the crystallizer or chilling rolls thru which either cold water or brine is pumped. From the roll the powder is scraped off clean by a knife, passes to a screen which sends the tailings to a grinder, falls into a storage bin from whence it is weighed and packed by an automatic weighing machine into cartons made up in most cases by another machine. Due to the large percentage of moisture contained in these soap powders the carton is generally wrapped in wax paper to aid in the prevention of the escape of moisture. SCOURING POWDERS. Scouring powders are very similar to soap powders and differ only in the filler used. We have already considered these fillers under scouring soap, from which they do not differ materially. They are usually insoluble in water to aid in scouring. The mixer used for substances of this kind in incorporating the soap and alkali must be of strong construction. SCOURING SOAP. Scouring soaps resemble soap powders very closely in their composition, in that they are a combination of soap and filling material. Since more lather is required from a scouring soap than in soap powders, a cocoanut oil soap is generally used. The usual filling material used is silex. The greatest difficulty in the manufacture of scouring soap is the cracking of the finished cake. This is usually due to the incorporation of too great an amount of filler, or too high a percentage of moisture. In manufacturing these soaps the cocoanut oil is saponified in the crutcher with 38 degs. B. lye, or previously saponified as a run soap, as already described under "Marine Soaps." To twenty-five parts of soap are added a percentage of 38 degs. B. sal soda or soda ash solution, together with a small quantity of salt brine. To this mixture in the crutcher seventy-five parts of silex are then added, and a sufficient amount of hot water to make the mass flow readily. Care must be exercised to not add too great a quantity of water or the mass will crack when it cools. The mass is then framed and cut before it sets, or poured into molds and allowed to set. While silex is the most extensively used filler for scouring soaps, it is feasible to incorporate other substances of like character, although it is to be remembered that the consumer is accustomed to a white cake, such as silex produces. Any other material used to replace silex should also be as fine as this product. FLOATING SOAP. Floating soap occupies a position midway between laundry and toilet soap. Since it is not highly perfumed and a large piece of soap may be purchased for small cost, as is the case with laundry soap, it is readily adaptable to general household use. Floating soap differs from ordinary soap in having air crutched into it which causes the soap to float in water. This is often advantageous, especially as a bath soap, and undoubtedly the largest selling brand of soap on the American market today is a floating soap. In the manufacture of floating soap a high proportion of cocoanut oil is necessary. A most suitable composition is one part cocoanut oil to one part of tallow. This is an expensive stock for the highest grade of soap and is usually cheapened by the use of cottonseed or various other liquid oils. Thus it is possible to obtain a floating soap from a kettle stocked with 30 per cent. cocoanut oil, 15 per cent. cottonseed oil and 55 per cent. tallow. With this quality of soap, however, there is a possibility of sweating and rancidity, and of the soap being too soft and being poor in color. The process of manufacture is to boil the soap in an ordinary soap kettle, after which air is worked into the hot soap by a specially constructed crutcher, after which the soap is framed, slabbed, cut into cakes and pressed. Concerning the boiling of the soap, the saponification must be carefully carried out, as the high proportion of cocoanut oil may cause a violent reaction in the kettle causing it to boil over. The method of procedure is the same as for a settled soap up to the finishing. When the mass is finally settled after the finish, the soap should be more on the "open" side, and the object should be to get as long a piece of goods as possible. Due to its high melting point, a much harder crust forms on the surface of a floating soap and in a greater proportion than on a settled soap during the settling. In a large kettle, in fact, it has been found impossible to break through this crust by the ordinary procedure to admit the skimmer pipe. Much of the success of the subsequent operations depends upon the completeness of the settling, and in order to overcome the difficulties occasioned by the formation of the crust everything possible should be done in the way of covering the kettle completely to enable this period of settling to continue as long as possible. When the soap is finished it is run into a specially constructed U-shape crutcher, a Strunz crutcher is best adapted to this purpose, although a rapidly revolving upright screw crutcher has been found to give satisfaction upon a smaller scale, and a sufficient quantity of air beaten into the soap to make it light enough to float. Care must be taken not to run the crutcher too rapidly or the soap will be entirely too fobby. During this operation the mass of soap increases in bulk, and after it has been established how much air must be put into the soap to satisfy the requirements, this increase in bulk is a criterion to estimate when this process is completed. It is of course understood that the longer the crutching continues the greater quantity of air is incorporated and the increase of volume must be established for a particular composition by sampling, cooling the sample rapidly and seeing if it floats in water. If the beating is continued too long an interval of time, the finished soap is too spongy and useless. The temperature of the mass during crutching is most important. This must never exceed 158 degrees F. At 159 degrees F. the operation is not very successful, yet the thermometer may indicate 140 degrees F. without interfering with this operation. If, however, the temperature drops too low, trouble is liable to be met with, by the soap solidifying too quickly in the frames. When the crutching is completed, the soap is allowed to drop into frames through the valve at the bottom of the crutcher and rapidly crutched by the hand in the frames to prevent large air spaces and then allowed to cool. It is an improvement to jolt the frames as they are drawn away as this tends to make the larger air bubbles float to the surface and thus reduce the quantity of waste. When the soap has cooled, the frame is stripped and the soap slabbed as usual. At this point a layer of considerable depth of spongy soap will be found to have formed. This of course must be cut away and returned to the kettle. The last few slabs are also often rejected, inasmuch as the weight of the soap above them has forced out so much of the air that the soap no longer floats. As a fair average it may be estimated that not more than 50 to 60 per cent. of the soap in the kettle will come out as finished cakes. the remaining 40 to 50 per cent. being constituted by the heavy crust in the kettle, the spongy tops, the bottom slabs and scrapings. This soap is of course reboiled and consequently not lost, but the actual cakes obtained are produced at a cost of practically double labor. It is advisable to add a small quantity of soap blue color to the mass while crutching to neutralize the yellowish tint a floating soap is liable to have. Some manufacturers add a percentage of carbonate of soda, about 3 per cent., to prevent the soap from shrinking. Floating soap may also be loaded with sodium silicate to the extent of about 5 per cent. TOILET SOAP. It is not a simple matter to differentiate between toilet soaps and various other soaps, because numerous soaps are adaptable to toilet purposes. While some soaps of this variety are manufactured by the cold made or semi-boiled process, and not milled, the consumer has become accustomed to a milled soap for general toilet use. The toilet base most extensively employed is a tallow and cocoanut base made as a full boiled settled soap. The manufacture of this base has already been outlined and really needs no further comment except that it is to be remembered that a suitable toilet soap should contain no great excess of free alkali which is injurious to the skin. Cochin cocoanut oil is preferable to the Ceylon cocoanut oil or palm kernel oil, to use in conjunction with the tallow, which should be a good grade and color if a white piece of goods is desired. The percentage of cocoanut oil may be anywhere from 10 to 25 per cent., depending upon the kind of lather required, it being remembered that cocoanut oil increases the lathering power of the soap. In addition to a tallow base, numerous other oils are used in the manufacture of toilet soaps, especially palm oil, palm kernel oil, olive oil and olive oil foots, and to a much less extent arachis or peanut oil, sesame oil and poppy seed oil, oils of the class of cottonseed, corn and soya bean oils are not adapted to manufacturing a milled soap, as they form yellow spots in a finished cake of soap which has been kept a short time. Palm oil, especially the Lagos oil, is much used in making a palm base. As has already been stated, the oil is bleached before saponification. A palm base has a yellowish color, a sweetish odor, and a small quantity added to a tallow base naturally aids the perfume. It is especially good for a violet soap. The peculiarity of a palm oil base is that this oil makes a short soap. By the addition of some tallow or twenty to twenty-five per cent. of cocoanut oil, or both, this objection is overcome. It is a good plan in using a straight palm base to add a proportion of yellow color to hold the yellowish tint of this soap, as a soap made from this oil continues bleaching upon exposure to air and light. Olive oil and olive oil foots are used most extensively in the manufacture of castile soaps. The peculiarity of an olive oil soap is that it makes a very slimy lather, and like palm oil gives the soap a characteristic odor. An olive oil soap is usually considered to be a very neutral soap and may readily be superfatted. Much olive oil soap is used in bars or slabs as an unmilled soap and it is often made by the cold process. Peanut oil or sesame and poppy seed oil often replaces olive oil, as they form a similar soap to olive oil. In the manufacture of a toilet soap it is hardly practical to lay down a definite plan for the various bases to be made. From the combination of tallow, palm oil, cocoanut oil, palm kernel oil, olive oil and olive oil foots, a great many bases of different proportions might be given. The simplest method is to make a tallow base, a palm base and an olive oil base. Then from these it is an easy matter to weigh out any proportion of these soap bases and obtain the proper mixture in the mill. If, however, as is often the case, a large quantity of soap base of certain proportions of these, four or even more of these fats and oils is required, it is not only more economical to stock the kettle with the correct proportion of these oils, but a more thorough mixture is thus obtained by saponifying these in the kettle. In view of the fact that it is really a question for the manufacturer to decide for himself what combination of oils he desires for a particular soap we will simply outline a few typical toilet soap bases in their simplest combination. It is understood that these soaps are suitable for milled soaps and are to be made as fully boiled settled soaps. Palm kernel oil may be substituted for cocoanut oil in all cases. TALLOW BASE. Tallow 75-90 parts Cocoanut oil 25-10 parts PALM BASE. Bleached Lagos palm oil 75-80 parts Cocoanut oil 25-20 parts or Tallow 30 parts Palm oil 60 parts Cocoanut oil 10 parts OLIVE OIL BASE (WHITE). Olive oil 75-90 parts Cocoanut oil 25-10 parts or Olive oil 40 parts Tallow 40 parts Cocoanut 20 parts Where a green olive oil base is desired, olive oil foots are substituted for the olive oil. Peanut oil may replace the olive oil or part of it, the same being true of sesame oil and poppy seed oil. PALM AND OLIVE BASE. Palm oil 50 parts Olive oil 30 parts Cocoanut oil 20 parts or Palm oil 20 parts Olive oil 10 parts Tallow 50 parts Cocoanut oil 20 parts CHEAPER TOILET SOAPS. It is often necessary to manufacture a cheaper grade of soap for toilet purposes to meet the demand of a certain class of trade as well as for export. To accomplish this it is of course necessary to produce a very inferior product and run down the percentage of fatty acids contained in the soaps by the addition of fillers or to use cheaper oils in manufacturing. The most simple method of filling a soap is to load it at the mill with some substance much less expensive than the soap itself. Many of the cheaper toilet soaps, however, are not milled and it is, therefore, necessary to follow out some other procedure. Milled soaps, as has just been stated, are loaded at the mill. The consumers of cheaper toilet soaps in this country are accustomed to a milled soap and this grade of soap for home consumption is very often filled with numerous substances, but most generally by adding starch and talc. The addition of such materials of course later exhibit themselves by imparting to the cake of soap a dead appearance. Talc is more readily detected in the soap than starch by washing with it, as talc is insoluble and imparts a roughness to the soap, like sand or pumice, as the soap wears down. It may readily be added to 20 per cent. by weight. Starch is to be preferred to talc, in loading a soap, as it is not so readily noticeable in washing. It leaves the cake itself absolutely smooth although the lather formed is more shiny. This substance may be employed to as high a percentage as one-third the weight of the soap. It is, of course, possible to cheapen the best soap base by this method and the price may be further lowered by using the less expensive oils and fats to make the soap base. RUN AND GLUED UP SOAPS. A very cheap grade of soap may be made by making a run soap and adding the filler e. g. sodium silicate in the kettle during saponification. The percentage of fatty acids may be brought down to 10 per cent., although of course a soap of this type shrinks a whole lot upon exposure. In making a "glued up" soap the procedure is the same for making the soap itself as with a settled soap, except that the soap is finished "curd" and later filled in the crutcher. The percentage of fatty acids in a soap of this type is seldom below 50 per cent. The method of "gluing up" a soap is best illustrated by a typical soap of this character in which the kettle is charged with the following stock. Bleached palm oil 5 parts Distilled grease 2 " Cotton oil foots stock, 63% fatty acid 1 " Rosin 4 " The palm oil is first run into the kettle, saponified and washed to extract any glycerine, then the rest of the fats and finally the rosin. The soap is then finished and settled as with a boiled settled soap. To assure success it is absolutely necessary that the soap settle as long a period as possible, or until the temperature is about 150 degs. F. The ideal temperature for carrying out the "gluing up" process is 140 degs. F., as at a lower temperature than this the soap is liable to cool too quickly and not be thoroughly glued up. A higher temperature than 150 degs. F. causes delay in that the soap does not properly take the filler at a higher temperature and the soap must be kept in the crutcher until the temperature drops to the right point. The soap is run into the crutcher and the percentage of fatty acids run down to 50-55 per cent. with one of the following mixtures: Sodium silicate, 59-1/2° B. 1 part Potassium carbonate, 51° B. 1 " or Sodium silicate, 59-1/2° B. 1 part Potassium carbonate, 51° B. 1 " Sodium sulfate, 28° B. 1 " From 230 to 300 pounds of either of these mixtures are required for a crutcher holding 2,600 pounds of soap. The crutching is continued until the mass is well "spiked," that is to say, a freshly broken surface of the soap, as the crutcher blade is jerked away, stands up like shattered sheets in triangular form [Transcriber's note: three triangles]), which retain their shape perfectly. When this condition is realized the soap is run into frames which are carefully crutched by hand to remove any air spaces. The surface of the soap is then smoothed down and heaped up in the center. After standing a day to contract, the surface is again leveled and a snugly-fitting board placed on the top of the soap upon which a weight is placed or upon which the workman treads and stamps until the surface is flat, thus assuring the further removal of air spaces. The soap remains in the frame from six to eight days and is then slabbed, barred and pressed by the usual method employed for soaps thus handled without milling. In a soap of this nature no hard and fast rule can be laid down as to the quantity of solution to be used for "gluing up" or the strength of the solution. In a soap of the type described the most satisfactory appearing cake will be obtained from a soap containing 58 per cent. fatty acids. That is to say, about 8 per cent. to 10 per cent. filling solution is added per hundred pounds of soap. The filling solutions given are very satisfactory. Carbonate of soda should be avoided in connection with sodium silicate as the property of efflorescing on the surface of the finished cake after a short time will prove detrimental. To assure successful gluing up it is advisable to experiment upon a small scale to determine the exact extent to which the filling solution should be diluted. Various proportions of water are added to a certain quantity of the filled soap. After the soap has been filled in a small receptacle a sample is taken and rubbed between the fingers. If the freshly exposed surface is smooth and glossy, the filling solution is weak enough, if rough it is too strong. It is of course understood that the temperature must be correct, 140 degs. to 150 degs. F., or the soap will be rough. By this means the operator can readily judge the correct strength of his filling solution. When properly carried out a perfectly satisfactory soap is obtained. CURD SOAP. The object of a soap which is finished "curd" or grained, is to obtain a harder piece of goods from low titer fat or to increase the percentage of fatty acids in the finished soap. This is still another method of producing a cheap grade of soap as by its adoption the cheaper oils and fats may be used to obtain a firm piece of soap. A typical charge for curd soap is: Red oil 63 parts Tallow 10 " Rosin 27 " Cotton seed foots may be employed in place of red oil and a tallow of too high titer is not suitable for this kind of soap. The red oil and tallow are first saponified with 15 degs. B. lye, boiler pressure 80-90 pounds, 18 degs. B. lye for lower steam pressure, and two washings given to extract the glycerine. The rosin is added at the strengthening change and at the finish the soap is "pitched," that is to say, the soap is settled over night only. The next day the lyes are drawn off and a portion of the nigre pumped to another kettle which prevents later streaking of the soap. The soap is then boiled with 18 degs. B. lye as with another strengthening change under closed steam. Salt brine or "pickle," 15 degs. B. is then added and the mass boiled with closed steam until the brine reaches a density of 18 degs. B. and the kettle pumped the next day. A soap of this type requires either hand or power crutching to assure homogeneity and prevention of streaks. To obviate any air spaces it is advisable to place over the top of the frame a tightly-fitted board which is heavily weighted down. This soap is also pressed without any milling. COLD MADE TOILET SOAPS. Comparatively little toilet soap is made by the cold or semi-boiled processes. While these are the simplest methods of manufacturing soaps the drawbacks of using them are numerous and only in a few cases are they very extensively employed. To make a toilet soap by the cold process a combination of good grade tallow and cocoanut oil is required. It requires 50 per cent. by weight of 36 degs. B. lye to saponify a given weight of tallow and 50 per cent. of 38 degs. B. lye for cocoanut oil. The lyes are used full strength or may be reduced slightly with water and the method of procedure is the same as already given in the general directions for cold made soaps. Cold made soaps are readily filled with sodium silicate which is added at the same time the stock is put into the crutcher. In adding the silicate it is necessary to add additional lye to that required for saponifying the fats, about 20 per cent. of 36 degs. B. lye is the proper amount. There is of course a certain amount of shrinking due to the addition of this filler and the finished cake is exceedingly hard, yet the author has seen a good looking cake of cheap soap made from as high a proportion as 420 parts of tallow to 600 parts of silicate. Cold made soaps are usually pressed without milling, although it is readily feasible to mill a cold made soap provided it is not a filled soap such as has just been described. PERFUMING AND COLORING TOILET SOAPS. Equally important as the soap itself or even to a greater extent is the perfume of a toilet soap. A prominent manufacturer recently made the statement, which is often the truth, that it makes no difference to the public what kind of soap you give them, as long as you put plenty of odor into it. The perfuming of soaps is an art in itself and a subject to be treated by one versed in this particular branch. We can only take into account the importance of the perfume as related to toilet soap not only, but the necessity of adding a certain proportion of the cheaper products of odoriferous nature to laundry soap to cover and disguise the odor of even this type of soap. The price of a cake of toilet soap to a great extent depends upon the perfume, and the manufacturer should aim to give the best possible perfume for a certain price. He should not allow his personal likes or dislikes to enter into the judgment of whether an odor is good or not, but submit it to a number of persons to obtain the concensus of opinion. In giving or selling a piece of soap to the consumer, it is second nature for him to smell it, and in the great majority of cases his opinion is formed not from any quality the soap itself may have during use, but from the odor. This only emphasizes the fact that the perfume must be pleasing, not to one person, but to the majority, and many brands owe their popularity to nothing more than the enticing perfume. Perfuming of soap is closely allied to the soap making industry, but as stated a branch in itself. It is, therefore, not our purpose to give numerous formulae of how to perfume a soap, but rather to advise to go for information to some one who thoroughly understands the characteristics of the numerous essential oils and synthetics and give positive information for the particular odor desired. Under no circumstances is it advisable to purchase a perfume already compounded, but since all perfumes are a blend of several or many essential oils and synthetics, it is a more positive assurance of obtaining what is desired, by purchasing the straight oils and blending or mixing them as one desires. The perfume is added to a milled soap just before the milling process in the proper proportion per hundred pounds of soap. In cold made or unmilled soaps it is added in the crutcher while the soap is still hot. By this method, of course, a proportion of the perfume is lost due to its being more or less volatile. COLORING SOAP. While much toilet soap is white or natural in color, many soaps are also artificially colored. The soap colors used for this purpose are mostly aniline dyestuffs. The price of these dyestuffs is no criterion as to their quality, as the price is usually regulated by the addition of some inert, water soluble substance like common salt or sugar. The main properties that a dyestuff suitable for producing a colored soap should have are fastness to light and to alkali. They should further be of such a type that the color does not come off and stain a wash cloth or the hands when the soap is used and should be soluble in water. Under no circumstances is it advisable to add these in such a quantity that the lather produced in the soap is colored. It is customary to first dissolve the dye in hot water as a standardized solution. This can then be measured out in a graduate and added to the soap the same time as the perfume is put in. About one part of color to fifty parts of water is the proper proportion to obtain a perfect solution, though this is by no means fixed. In making up a solution thus it is an improvement to add to the same about one-half of one per cent. of an alkali either as the hydroxide or carbonate. Then, if there is any possibility of change of color due to alkalinity of the soap, it will exhibit itself before the color is added. A particularly difficult shade to obtain is a purple, as there is up to the present time no purplish aniline color known which is fast to light. Very good results in soap may be obtained by mixing a fast blue, as ultramarine or cobalt blue, with a red as rhodamine or eosine. Inasmuch as the colors for soap have been carefully tested by most of the dyestuff manufacturers, and their information, usually reliable, is open to any one desiring to know about a color for soap, it is better to depend upon their experience with colors after having satisfied one's self that a color is what it is represented for a particular shade, than to experiment with the numerous colors one's self. MEDICINAL SOAPS. Soap is often used for the conveyance of various medicants, antiseptics or other material presumably beneficial for treatment of skin diseases. While soap is an ideal medium for the carrying of such materials, it is an unfortunate condition that when incorporated with the soap, all but a very few of the numerous substances thus employed lose their medicinal properties and effectiveness for curing skin disorders, as well as any antiseptic value the substance may have. Soap is of such a nature chemically that many of the substances used for skin troubles are either entirely decomposed or altered to such an extent so as to impair their therapeutic value. Thus many of the claims made for various medicated soaps fall flat, and really have no more antiseptic or therapeutic merit than ordinary soap which in itself has certain germicidal and cleaning value. In medicating a soap the material used for this purpose is usually added at the mill. A tallow and cocoanut oil base is best adapted for a soap of this type. The public have been educated more or less to the use of colored soap to accentuate its medicinal value, and green is undoubtedly the most popular shade. This inference, however, is by no means true for all soaps of this character. Possibly the best method of arranging these soaps is briefly to outline some medicinal soaps. SULPHUR SOAPS. The best known sulphur soaps contain anywhere from one to 20 per cent. of flowers of sulphur. Other soaps contain either organic or inorganic sulphur compounds. TAR SOAP. The tar used in the manufacturing of tar soap is obtained by the destructive distillation of wood, the pine tar being the most extensively employed. While the different wood tars contain numerous aromatic compounds, such as phenols, phenyl oxides, terpenes and organic acids, these are present in such a slight proportion so as to render their effectiveness practically useless. It has, therefore, been tried to use these various compounds contained in the tar themselves to make tar soap really effective, yet tar is so cheap a substance that it is usually the substance used for medicating a tar soap. About 10 per cent. of tar is usually added to the soap with 2 ounces of lamp black per hundred pounds of soap. SOAPS CONTAINING PHENOLS. Phenol (Carbolic Acid) is most extensively used in soaps of this kind, which are called carbolic soaps. Carbolic soaps are generally colored green and contain from 1 to 5 per cent. phenol crystals. The cresols are also extensively used for making soaps named carbolic. These substances impart more odor to the soap and really have more disinfecting powers than phenol when incorporated with soap. Other soaps, containing the phenol group, which are well known are resorcinol soap, salol soap, thymol soap, naphthol soap, etc. From one to five per cent of the compound after which the soap is named is usually incorporated with the soap. PEROXIDE SOAP. Hydrogen peroxide in itself is an excellent disinfectant. It loses all its medicinal value, however, when added to the soap. To overcome this objection various metallic peroxides are added to the soap, as sodium peroxide, zinc peroxide and barium peroxide. These generate hydrogen peroxide by the addition of water. Sodium perborate is also used in peroxide soaps, as this substance is decomposed by water into hydrogen peroxide and sodium metaborate. MERCURY SOAPS. Mercuric chloride (corrosive sublimate) is most extensively used for the production of mercury soaps. Because of its extremely poisonous properties care should be taken in using it. Since it really eventually loses any antiseptic value in the soap through forming an insoluble mercury soap it might better be omitted entirely. LESS IMPORTANT MEDICINAL SOAPS. While the above mentioned soaps are probably the best known medicated soaps, there are numerous other soaps which may be classed under these kinds of soaps. Thus we have cold cream soap, which can be made by adding Russian Mineral Oil, 1 to 5 per cent., to the soap; witch hazel soap, made by the addition of extract of witch hazel; iodine soap, made by adding iodine or iodoform; formaldehyde soap, made by adding formaldehyde; tannin soaps, made by adding tannin. In fact, there have been incorporated in soap so great a number of substances that the list might be greatly enlarged. Medicated soaps are not only used in solid form, but in powder, paste and liquid soap as well. The only difference in a soap like those just referred to is that the medicant is incorporated with these forms of soaps as convenience directs. CASTILE SOAP. A pure castile soap should be made from olive oil. This, however, is not always the case, as a number of oils as well as tallow are used to adulterate this oil to cheapen it, and there are even some soaps called castile which contain no olive oil at all. Most of the pure castile soap used in this country is imported, as it is a difficult matter for the American manufacturer to compete with the pure imported castile soap, since both labor and oil itself are so much cheaper in the vicinities of Europe where this oil is produced, that this advantage is more than compensated by the carrying and custom charges by importing the castile soap. Castile soap may be made either by the full boiled or cold process. There are numerous grades of olive oil, and those used for soap making are denatured to lower the duty charges. Olive oil makes a hard white soap, usually sold in bars, and olive oil foots a green soap, due to the coloring matter contained in this oil. To make a boiled castile soap, a composition of 10 per cent. Cochin cocoanut oil and 90 per cent. olive oil may be used. To cheapen this, peanut oil (Arachis oil) may entirely replace the olive oil, or about 20 per cent. of corn or soya bean oil may be added. The oils are saponified as usual in making a settled soap and to prevent rancidity the soap is boiled near the finish for some time in the closed state with sufficient excess of alkali to give it a sharp taste, then grained with lye, the lye drawn off, closed with water and then grained with salt. This process is repeated until the desired strength is reached. The last graining should not be too great, and on the last change the soap should not be thinned out, as it will contain too great a quantity of water when slabbed. In making a cold castile soap the usual method is pursued as already directed under cold made soap. When the soap is taken from the crutcher it is advisable, however, to keep the soap in the frame well covered to assure complete saponification. Some manufacturers use very small frames which are placed into compartments, well insulated to retain heat. Several formulae for cold made castile soaps, follow. It may be noted that some of these contain practically no olive oil. I Olive oil 2030 Palm kernel 674 Soda lye, 35 per cent. B. 1506 II Olive oil 2030 Cochin cocoanut oil 674 Soda lye, 36 per cent. B. 1523 Sodium Silicate 82 III Palm kernel oil 1578 Tallow 940 Olive oil 7 Sodium silicate, 20 per cent. 190 Soda lye, 36 per cent. B. 1507 IV Olive oil (yellow) 1000 Soda lye, 37 per cent. B. 500 V Olive oil 90 or Palm kernel } 10 Cochin or cocoanut oil } 10 Lye, 37 per cent. B. 51 If any of the soaps containing a high proportion of cocoanut oil are boiled the soap will float. It is therefore necessary to keep the temperature as low as possible. ESCHWEGER SOAP (BLUE MOTTLED). Eschweger soap is a colored mottled or marbled soap made to a very slight extent in this country. Inasmuch as it has been introduced to the export trade, it is made for this purpose by some manufacturers. A high percentage of cocoanut oil is usually used together with tallow and grease. About one-third of each is a typical formula. In a soap of this character the fact that cocoanut oil soap takes up a large quantity of water and salts of various kinds and is difficult to salt out is made use of. The tallow and grease are first saponified as usual, then the cocoanut oil is pumped and saponified. When the saponification is nearly completed either silicate or carbonate of soda or common salt are added to make the soap "short" so as to form the mottle. The finishing of a soap of this type can only be gained by practice and it is rather difficult to explain the exact appearance of the kettle at this stage. The surface of the soap should be bright and lustrous with the steam escaping in numerous places in rose-like formation. A sample on the trowel should have a slight sharpness to the tongue and be plastic. When the soap slides from the trowel it should break short. When the soap has reached this stage the desired coloring matter, usually ultramarine, is added to the soap either in the kettle or crutcher and the soap framed. The yield is 200-215 pounds per hundred pounds of stock. Several modifications of this general method for Eschweger soap are used by adopting the half boiled or cold process. TRANSPARENT SOAP. Transparent soap is really not a most desirable soap for toilet purposes, as it contains an excess of free alkali. It has, nevertheless, met with public approval because of the fact it is novel in being transparent. Except for this fact very little merit can be claimed for a soap of this kind. The transparency of soap is generally due to the presence of alcohol, sugar or glycerine in the soap when it is made. It is very essential in a soap of this character, where lightness and clearness of color are desired, that the material for making the soap be carefully selected as to color and purity. The perfumes also play an important part in the color of the soap and many of the tinctures, balsams and infusions used in perfuming soap may eventually cause trouble by spotting. If the soap is artificially colored, which is almost always the case, the dyestuffs used for this purpose should have careful attention and only those should be used which are known to resist the action of alkalis. Where rosin is used this product must be of the better grade. Distilled water is always preferable for use in transparent soap. The government permits the use of a specially denatured alcohol. This alcohol is not taxed and consists of grain (ethyl) alcohol denatured with 5 per cent. wood (methyl) alcohol. Some soapmakers prefer to use a more expensive refined methyl alcohol, but outside of adding to the cost of the soap, there is no particular advantage. The glycerine should be chemically pure. As to the oils and fats these should be low in acid and of good color. Under no circumstances should the crutcher or kettle in which the soap is made be rusty or unclean in any way. For a light soap enameled utensils are to be preferred. To obtain transparency in soap the following general methods may be given. 1. Where the transparency is due to sugar. 2. Where alcohol and glycerine produce transparency. 3. Where (1) or (2) is supplemented by the use of castor oil. 4. Where transparency depends upon the percentage of fatty acid in a soap and the number of times the soap is milled. Under the first method at least 25 per cent. of the charge should be cocoanut oil, the other constituent being tallow or any fat or oil capable of giving a sufficiently hard soap. The soap is boiled and finished as usual, then run to the crutcher to be mixed with a strong cane sugar solution, containing 10-20 per cent. sugar of the weight of the soap. The sugar is dissolved in its own weight of water and the solution heated to 175 degs. F. before being very slowly added to the soap. As the water evaporates, soaps of this type show spots due to the sugar thus being thrown out of solution. Transparent soap made under the second method may be saponified as usual and consist of any good toilet base. The soap is run to the crutcher and mixed with 95 per cent. alcohol in the proportion of one part alcohol to two parts of fatty acid contained in the soap together with glycerine in the same proportion. By the third method castor oil alone may be used to make the soap or added to any of the above bases up to 33-1/3 per cent. of the charge. If castor oil only is used, but 2 per cent. or 3 per cent. of sugar is required. In the last method a combination of 80 per cent. tallow, very low in free acid, 20 per cent. cocoanut oil and 5 per cent. W. W. rosin is a suitable charge. The saponification and finishing is carried out as with a full boiled soap. The soap is then placed into a jacketed vessel, provided with dry-steam coils, by which the excess water is evaporated from the soap until it contains 73 per cent. fatty acids. When the thick mass reaches this stage it is framed and when cool is suitable for obtaining a semi transparency which now depends upon the number of times the soap is milled, it being, of course, inferred that no solid matter of any sort be added to the soap. COLD MADE TRANSPARENT SOAP. While transparent soaps may be made by the above general methods they are usually made by the semi-boiled or cold process. By this process a more satisfactory soap is obtained and it is more simple to carry out. A detailed description of this method is best and most easily given by using a typical formula. Charge: Tallow 193-1/2 lbs. Cochin Cocoanut Oil 169-1/2 " Castor Oil 89-1/2 " Soda Ash 7-3/4 " Soda Lye, 36 degs. B. 256 " Sugar (Cane) 198 " Alcohol 126 " Water (Distilled) 80 " To proceed, first place into a crutcher or jacketed kettle the oils and fat and heat to 140 degs. F. Then add the soda ash dissolved in about 30 pounds of the water, after which the lye is added and the mass stirred until a finger or stick run over the surface leaves an imprint. Where the soap has reached this stage, it is well covered and allowed to stand about two hours or until it bulges in the center, after which the rest of the water which should contain no lime or other mineral substance and which is preferably distilled water, is added. The sugar is then slowly shoveled in while the mass is stirring and finally the alcohol is poured in. The heat is then increased to 160 degs. F. by dry steam and the soap crutched until dissolved. Under no circumstances should any soap be allowed to remain above the surface of the mass on the sides of the mixer. This crutching operation consumes about one hour, and when finished the soap should stand in the vessel about half an hour when a small sample is taken out to cool. This sample should be clear and show an excess of alkali. If it is not clear more alcohol is added, if not of sufficient strength more lye put in until the desired condition is reached. The perfume and color are now added. The soap is then framed and allowed to set after which it is cut, allowed to dry slightly and then pressed. To obtain a polished cake transparent soaps are often planed before pressing and after pressing polished with a soft cloth, dampened with alcohol. Instead of framing this soap, it is sometimes "tubed," that is to say, the soap from the crutcher is run into specially constructed tubes of a shape near that of the desired cake and allowed to cool, after which it is cut and pressed. All scraps are returned to the crutcher, but in so doing the soap is slightly darkened in color. It is advisable to expose a finished cake of transparent soap to the air for some time as by so doing it becomes clearer. Other formulae for cold made transparent soaps made as just outlined follow: I. Bleached Tallow 134 lbs. Cochin Cocoanut Oil 88 " Castor Oil 20 " W. W. Rosin 7 " Cane Sugar 64 " Water 32 " Glycerine 34 " Soda Lye, 38 degs. B. 135 " Alcohol 16 gal. II. Tallow 211 lbs. Cochin Cocoanut Oil 185 " Castor Oil 97-1/2 " Soda Ash 8-1/2 " Water 106 " Soda Lye, 38 degs. B. 279 " Sugar 216 " Alcohol 137 " III. Castor Oil 60 lbs. Cochin Cocoanut Oil 195 " Tallow 120 " Alcohol 115 " Sugar 90 " Water 53 " Glycerine 53 " Soda Lye, 38 degs. B. 205-1/2 " IV. Tallow 100 lbs. Cochin Cocoanut Oil 100 " Castor Oil 60 " Glycerine 20 " Rosin, W. W. 20 " Sugar 40 " Water 50 " Soda Lye, 36 degs. B. 164 " Alcohol 8 gal. V. Tallow 174 lbs. Cocoanut Oil 114 " Soda Lye, 38 degs. B. 170 " Sugar 80 " Water 72 " Alcohol 16 gal. Rosin may be added in this formula up to 20 per cent. of fats used and the tallow cut down correspondingly. SHAVING SOAPS. The requirements of a shaving soap are somewhat different than those of other soaps. To be a good shaving soap the lather produced therefrom must be heavy, creamy, but not gummy, and remain moist when formed on the face. The soap itself should be of a soft consistency so as to readily adhere to the face when used in stick form. It should furthermore be neutral or nearly so to prevent the alkali from smarting during shaving. Shaving soap is made in the form of a stick, and a tablet for use in the shaving mug. Some shavers prefer to have the soap as a powder or cream, which are claimed to be more convenient methods of shaving. While a liquid shaving soap is not as well known because it has not yet become popular, some soap for shaving is made in this form. Formerly shaving soap was extensively made from a charge of about 80 parts tallow and 20 parts cocoanut oil as a boiled settled soap, but either making the strengthening change with potash lye or using potash lye in saponifying the stock and graining with salt. Soaps for shaving made in this manner are very unsatisfactory, as they do not produce a sufficiently thick or lasting lather and discolor very materially upon ageing. Potassium stearate forms an ideal lather for shaving, but readily hardens and hence needs some of the softer oils, or glycerine incorporated with it to form a satisfactory soap for shaving. The selection of materials for making a shaving soap is important. The tallow used should be white and of high titer. Cochin cocoanut oil is to be preferred to the other kinds, and the alkalis should be the best for technical use that can be purchased--76 per cent. caustic soda and 88-92 per cent. caustic potash are suitable. By the use of stearic acid it is a simple matter to reach the neutral point which can be carefully approximated. The following are shaving soap formulae which have been found to give good satisfaction: I. lbs. Tallow 360 Stearic acid 40 Soda lye, 41° B. 147 Potash lye, 34° B. 87 Water 32 Gum tragacanth 1 II. lbs. Tallow 282 Cocoanut oil 60 Stearic acid 50 Bayberry wax 18 Soda lye, 41° B. 147 Potash lye, 34° B. 90 Water 32 III. lbs. Tallow 400 Cocoanut oil 176 Stearic acid 415 Caustic soda, 40° B. 182 Caustic potash, 38° B. 108 To proceed, first run into the crutcher the tallow, cocoanut oil and bayberry wax when used, and bring the temperature of the mass up to 140°-160° F. by dry steam. Then add the caustic soda lye and keep on heat with occasional mixing until it is all taken up. When this stage is reached gradually add all but about 5 per cent. of the potash lye, and complete the saponification. This point having been reached, the heat is turned off; the crutcher is run and the stearic acid, previously melted by dry steam in a lead-lined or enameled vessel, is run in in a continuous stream and the crutching continued for fifteen minutes to half an hour. Samples are taken at this time, cooled and tested by alcoholic phenolphthalein solution. If too alkaline more stearic acid is added, if too acid more potash lye from that previously reserved. After each addition of lye or stearic acid the mass is crutched from 10 to 15 minutes longer, another sample is taken, cooled and again tested. When the phenolphthalein shows a very light pink after several minutes, the soap is practically neutral, although at this point one can better judge by dissolving a sample in hot neutralized alcohol made by putting into the alcohol a few drops of phenolphthalein, and then adding weak alkali drop by drop from a burette until a slight pink, not yellow, tint is obtained, and noting the color of the solution. The solution should show a very light pink when the soap is properly neutralized. When this stage is arrived at the gum tragacanth, previously softened in water, is crutched in if it is to be added. The soap is then framed, stripped in three or four days, dried and milled. The formulae as given are for shaving sticks, and do not readily press unless thoroughly dried. A more satisfactory result is obtained by adding at the mill 25 per cent. of white tallow base to obtain a satisfactory mug soap. SHAVING POWDER. Shaving powder differs from the soaps just described in being pulverized, usually adding up to 5 per cent. starch to prevent caking. Any of the above soaps, dried bone dry, with or without the addition of tallow base make a satisfactory powder for shaving. SHAVING CREAM. Shaving cream is now a very popular shaving medium due to the rapidity and convenience with which one can shave by the use of this product. Formerly shaving cream was made from the liquid oils like olive oil and a soft fat like lard, together with cocoanut oil. Now, however, most of the popular shaving creams are made from stearic acid and cocoanut oil, as a far superior product is obtained by the use of these substances. By using these a more satisfactory cream is obtained, and it is far more convenient to make. The lather also produced therefrom is more suitable for shaving, being thick, creamy and remaining moist. A few typical formulae for shaving creams of this type are as follows: I. lbs. Cochin cocoanut oil 26 Stearic acid 165 Caustic potash lye, 50° B. 69 Glycerine C. P. 76 Water 38 II. lbs. Cochin cocoanut oil 18 Stearic acid 73 Caustic potash lye, 39° B. 54 Glycerine 33 Water 27 III. lbs. Cochin cocoanut oil 18 Stearic acid 73 Caustic potash lye, 39° B. 54 Glycerine 20 Water 40 and lbs. Stearic acid 60 Glycerine C. P. 85 Water 165 Sodium carbonate 50 Borax 1 To make a shaving cream by Formula I or II, the cocoanut oil and glycerine are first put into a suitable mixing apparatus or crutcher, and heated to 120° F. A part or all the potash lye is then added and the cocoanut oil saponified. The rest of the potash lye and the water are then added, and with the mixer running the stearic acid, previously melted in a lead-lined or enameled vessel, is then poured in in a stream and the mass stirred until smooth, care being exercised not to aerate it too much. The cream is then tested for alkalinity, the best method being by that described under shaving soap, in which the sample is dissolved in alcohol. Because of the large quantity of water present, phenolphthalein is unsatisfactory, as dissociation of the soap may show a pink indication in spite of the fact the mass is on the acid side. For a quick method of testing the bite on the tongue is a satisfactory criterion. If a cooled sample bites the tongue more stearic acid is added until there is a 3% excess of this. When the proper neutralization has taken place the cream is perfumed and framed in a special frame, or it may be allowed to cool in the mixer and perfumed the next day. When cool the cream is strained, or put through an ointment mill, after which it is ready to fill into tubes. The procedure for the first part of Formula III is the same as that just given. The second part of the formula is made the same as a vanishing cream for toilet purposes. To make this, first melt the stearic acid as already directed. Dissolve the sodium carbonate and borax in water and when dissolved add the glycerine and stir. Then heat this solution to about 100°-120° F. and while stirring in a suitable mixing machine into which this solution has been poured after being heated, or better still in which it has been heated by dry steam, add the stearic acid. Continue mixing until smooth and then allow to cool, or run into frames to cool. When the shaving cream and vanishing cream are both cool, they are mixed in the proportion of one of the former to two of the latter. It is claimed that in thus making a shaving cream a smoother product is obtained, although it may be said that the vanishing cream is merely a soft soap and the ultimate result is the same as though the various ingredients were added in one operation, rather than making two separate products and then mixing them, thereby considerably increasing the cost of manufacture. PUMICE OR SAND SOAPS. Pumice and sand are at times added to soap to aid in the removal of dirt in cleansing the hands. In some cases these soaps are made in the form of a cake, in others they are sold in cans in the form of a paste. A hand paste is usually made by merely dissolving ordinary tallow base in two or three times its weight of hot water and mixing in the desired quantity of pumice or sand and in some instances adding a little glycerine to keep it soft or a solvent of some kind for grease. It may also be made by directly incorporating any of these in a potash soap. A cold made or semi-boiled cocoanut or palm kernel oil soap is the base used to add the pumice or sand to in making a cake soap of this sort. The following formulae serve as a guide for these soaps. I. Palm Kernel or Ceylon Cocoanut Oil 705 lbs. Pumice (Powdered) 281 " Soda Lye, 38° B. 378 " II. Cocoanut Oil 100 " Soda Lye, 38° B. 55 " Water 6 " Silver Sand (fine) 60 " To proceed place the oil in a crutcher and heat to 140° F. Sift in the pumice and mix thoroughly. The lye is then added which causes a curdling of the grain. The stirring is continued until the grain closes and the soap is smooth, after which the desired perfume is added and the soap dropped into a frame and crutched by hand. When the soap is set, it is slabbed, cut into cakes, dried slightly and pressed. LIQUID SOAPS. Liquid soaps are merely solutions of a potash soap, usually cocoanut oil soap, although corn oil is used to make a cheap soap. One of the difficulties encountered in liquid soap is to keep it clear. At a low temperature a sediment is often formed, but this can be overcome by the use of sugar and filtering the soap through a filter press at a low temperature. In order to prevent the soap from freezing, it is necessary to lower the freezing point by the addition of glycerine or alcohol. To make liquid soap by any of the formulae given below, the oil is first run into a jacketed kettle with a stirring device, and heated to about 120° F. The potash lye is then added and the oil saponified. When the saponification takes place, especially when cocoanut oil is used, the mass swells rapidly and may foam over the sides of the kettle unless water is used to check this, or a kettle of about four to five times the capacity of the total charge of soap is used. When the saponification has occurred, the sugar, borax and glycerine are added, the water run in and the mixture stirred until the soap is thoroughly dissolved. Heat aids materially in dissolving the soap. The soap is then allowed to cool and if color or perfume is to be added this is stirred in, after which the soap is cooled and filtered or else run directly into barrels. Tallow is not suitable for making a clear liquid soap since it is too high in stearine which when formed into the stearate makes an opaque solution. The formulae herewith given have been found to give good practical results. I. lbs. Cocoanut oil 130 Caustic potash lye, 28° B. 135 Sugar 72 Borax 2 Water 267 II. lbs. Corn oil 130 Caustic potash lye, 26° B. 135 Sugar 72 Borax 2 Water 267 III. lbs. Cocoanut oil 100 Caustic potash lye, 28° B. 102 Glycerine 100 Sugar 70 Water 833 Formulae I and II contain about 20 per cent. fatty acids. It is possible, of course, to either increase or decrease the percentage of fatty acid by varying the amount of water. The water used in making liquid soaps, of course, should be soft, for hard water forms insoluble soaps which precipitate and cause a sediment. USE OF HARDENED OILS IN TOILET SOAPS. While the introduction of the hydrogenation of oils is a decided advance in the production of suitable cheaper oils for soap making, comparatively little hardened oil is employed for soap making in America up to the present time. In Europe, however, considerable advance has been made by the use of such oils for manufacturing soap therefrom and a number of plants turn out large quantities of hydrogenated oils for soap making as well as for edible purposes. Recently a company has been formed in this country for hardening oils and it is very probable that the future will see this material extensively used in our own country, as these appear to be the one present hope of the soap manufacturer as a check on the ever increasing cost of fats and oils now used in making soap. It is an unfortunate condition that hydrogenated oils produced abroad are sold under names which give absolutely no indication as to the oil which has been hardened. The softer and cheaper oils like fish oil, linseed oil, cottonseed oil, etc., are generally hardened for soap manufacture to different degrees of hardness. While it is impossible to definitely state just what products as Candelite, Talgol, Krutolin or several other coined names of hardened oils are, various investigators have experimented with them as to their adaptability for producing toilet soaps and found that suitable toilet soaps may be made from them. While many objections were at first met with concerning soaps made from these products, as to their unsatisfactory saponification, the poor lathering quality of the soaps and their odor and consequent difficulty in perfuming, the results of most investigators along these lines indicate that these in many cases were due to prejudice against or unfamiliarity with handling oils of this type for soap making. In manufacturing soap from hardened oils it is usually necessary to incorporate with the charge lard, tallow, tallow oil or some other soft oil of this nature. Satisfactory bases for toilet soaps, made as boiled settled soap by the use of Talgol (undoubtedly hardened fish oil), are said to be made by the formulae[10] below. I. Tallow 45 parts Talgol 40 " Cocoanut Oil 15 " II. Cocoanut Oil (Ceylon) 6 " Tallow 12 " Talgol, Extra 12 " The method of boiling a soap of this type does not differ materially from that of making settled tallow soap base. The soap itself has a different odor than a straight tallow base, but is said to make a very satisfactory soap for milling and to be of good appearance. Satisfactory transparent soaps are made from the hardened oil Candelite, which replaces the tallow in transparent soap formulae such as have already been given in the section under "Transparent Soaps." The method of manufacturing a soap by the use of this product varies in no way from the usual method employed for making these soaps. Since hydrogenated oils are high in stearine, their use in shaving soaps is a decided advantage. It has previously been pointed out that potassium stearate forms an ideal lather for shaving, and in the hydrogenating process the olein is converted to stearine. Thus a hardened oil is advantageous in a shaving soap. As an example of a cold made soap for shaving the following may be taken.[11] Talgol Extra 50 lbs. Cocoanut Oil 10 " Lard 10 " Soda Lye, 38° B. 20 " Potash Lye, 37° B. 21 " This soap may be made in a crutcher by the method generally used in making soap by the cold process. TEXTILE SOAPS. Soap is a very important product to every branch of the textile industry. For woolen fabrics it is used for scouring, fulling and throwing the wool; in the silk industry it is necessary for degumming the raw silk, as well as for dyeing; in the cotton mills it is used to finish cotton cloth and to some extent in bleaching; it is, furthermore, employed in a number of ways in the manufacture of linen. Large quantities of soap are thus consumed in an industry of so great an extent and the requirements necessitate different soaps for the different operations. We will, therefore, consider these in detail. SCOURING AND FULLING SOAPS FOR WOOL. The soaps used to scour wool and for fulling the woven cloth are usually made as cheaply as possible. They are, however, generally pure soaps, as filling material such as sodium silicate does not readily rinse out of the wool and if used at all must be added very sparingly. Both cold made and boiled settled soaps are made for this purpose. The soap is generally sold in barrels, hence is run directly to these from the crutcher or soap kettle. As cold made soaps the following serve for wool scouring or fulling. I. Palm Oil 200 lbs. Bone Grease 460 " Soda Lye, 36° B. 357 " Water 113 " Soda Ash 50 " Citronella 2 " II. Palm Oil (Calabar, unbleached) 155 " House Grease 360 " Soda Lye, 36° B. 324 " Water 268 " Sodium Silicate 83 " III. House Grease 185 " Palm Oil (unbleached) 309 " Soda Lye, 36° B. 309 " Water 391 " Soda Ash 70 " Sodium Silicate 60 " Corn Starch 10 " These soaps are made in a crutcher by the usual process for cold-made soaps, crutched until smooth, dropped into a barrel and crutched by hand the next day or just before cooling. As a settled soap for these operations the following charge is typical: Palm Oil 34 parts Cottonseed foots or its equivalent in fatty acids 33 " Rosin 10 " House Grease 23 " The method of boiling such a soap is the same as for any settled soap up to the strengthening change. When this stage is reached, sufficient lye is added to strengthen the kettle strongly. It is then boiled down with closed steam on salt brine or "pickle" until a sample of the lye taken from the bottom stands at 16°-22° B. The soap is then run into barrels and after standing therein for a day is hand crutched until cool to prevent streaking of the soap. Besides a soap of this type a settled tallow chip soap is used. WOOL THROWER'S SOAP. Soaps for wool throwing are sometimes made from olive oil foots but these are often objected to because of the sulphur-like odor conveyed to the cloth due to the method by which this oil is extracted with carbon disulphide. A potash soap hardened somewhat with soda is also used. As a formula for a suitable soap of this type this may be given. Olive Oil Foots 12 parts Corn Oil 46 " House Grease 20 " Soda Lye, 36° B. 3 " Potassium Carbonate (dry) 5-3/4 " Potassium Hydrate (solid) 23 " This soap is made as a "run" soap by the general directions already given for a soap thus made. The kettle is boiled with open and closed steam, adding water very slowly and aiming to obtain a 220-225 per cent. yield or fatty acid content of the finished soap of 46 per cent. When the soap is finished a sample cooled on a plate of glass should be neither slippery or short, but should string slightly. The finished soap is run directly into barrels. A soap for wool throwing by the semi-boiled process may be made from olive oil foots in a crutcher thus: Olive Oil Foots 600 lbs. Potash Lye, 20° B. 660 " The oil is heated to 180° F., the lye added and the mass stirred until it bunches, when it is dropped into barrels. WORSTED FINISHING SOAPS. For the finishing of worsted cloth soaps high in cocoanut oil or palm kernel oil are preferred. These soaps are finished very neutral, being made as settled soaps, but given an extra wash change after strengthening strongly. They are then finished as usual and run into barrels. If framed too hot, the high percentage of cocoanut oil causes mottling, which is prevented by crutching by hand until the temperature of the soap is 140°-145° F. Some typical charges, all of which are saponified with soda lye, follow: I. Palm Kernel Oil 60 parts Corn Oil 40 " II. Palm Kernel Oil 30 " Red Oil (single pressed) 70 " III. Red Oil 33-1/3 " Corn Oil 33-1/3 " Cocoanut Oil or Palm Kernel Oil 33-1/3 " SOAPS USED IN THE SILK INDUSTRY. Soap is used to a very large extent in silk mills, both for degumming the raw silk and in silk dyeing. Raw silk consists of the true silk fibre known as fibroin and a gummy coating, sericin, which dulls the lustre of the silk unless removed. For this purpose a slightly alkaline olive oil foots soap is best adapted, although palm oil and peanut oil soaps are sometimes used, as well as soaps made from a combination of house grease to the extent of 30 per cent., together with red oil or straight olein soaps, both of which are artificially colored green. In using house grease, if 30 per cent. is exceeded in combination with red oil, the titer is raised to such an extent that the soap does not readily rinse from the silk nor dissolve readily. They are also not advisable because they impart a disagreeable odor to the silk. To make a soap for this purpose from olive oil foots it is made as a settled soap, care being taken to thoroughly boil the mass on the saponification change in the closed state to assure proper saponification. The kettle is usually grained with lye and given a good wash change to remove the excess strength. The change previous to the finish should not be too heavy or too large a nigre results. The lighter the grain is, the better the finished kettle is. A yield of 150 per cent. is usually obtained. This soap is generally run to a frame, slabbed upon cooling and packed directly into wooden cases. For silk dyeing the above soap is suitable, although any well-made soap of good odor and not rancid is useable. While soap alone is often used in the bath for silk dyeing, certain dyestuffs require the addition of acetic or sulphuric acid, which sets free the fatty acids. If these be of bad odor it is taken up by the silk and is difficult to remove. The most generally used soaps are the just mentioned olive foots soap or a soap made from a good grade red oil. Both kinds are extensively used. SOAPS USED FOR COTTON GOODS. In the manufacture of cotton goods, as compared to the wool and silk industries, very much less soap is used and it is only applied to the finished fabric either to clean the cloth preparatory to dyeing or to aid in dyeing with certain colors. It is also used in calico printing. For cleansing the cloth ordinary chip soap is suitable although a more alkaline soap finished as a curd soap is an advantage in that the free alkali contained therein aids in removing the dirt and has no harmful effect on the cotton. For dyeing cotton goods or to brighten certain colors after dyeing an olive oil foots soap is most generally employed. In calico printing soap is used to wash and clear the cloth after printing. A soap for this purpose should be easily soluble in water and contain no free alkali, rosin or filler. The best soaps for use in calico printing are either an olive oil foots soap or an olein soap. SULPHONATED OILS. While sulphonated oils are not used to any great extent in the manufacture of soap, they are used very largely in the dyeing and printing of turkey and alizarine reds on cotton as well as other colors. Just what action these oils have is not known. Turkey red oil or sulphonated castor oil is the best known sulphonated oil. The process of making these oils is simple. The equipment necessary is a wooden tank or barrel of suitable capacity, approximately two and a half times the amount of oil to be treated. There are furthermore required other tanks or vessels to hold the solutions used such as caustic soda, ammonia and acid. The tank to be used for the preparation of sulphonated oil should be provided with a valve at the bottom of the tank and a gauge to measure the quantity of liquid therein. The process is carried out as follows: Three hundred pounds of castor oil are placed in the tank and 80 pounds at 66 deg. B. sulphuric acid are weighed out in another vessel. The acid is run into the tank containing the oil in a very thin stream while the oil is well stirred. At no time should the temperature exceed 40 deg. C. This operation should consume at least an hour and stirring should be continued half an hour longer to insure the thorough mixing of the oil with the acid. The mass is then allowed to settle for 24 hours, after which 40 gallons of water are added and the mixture stirred until it has a uniform creamy color indicating no dark streaks. This mixing process should be carefully carried out and when completed allowed to settle 36 hours. At this point the mass will have separated into two layers, the lower layer consisting of a water solution of acid and the upper layer of oil. The former is run out through the valve located at the bottom of the tank. Another wash may now be given or dispensed with as desired. In this wash the addition of salt or sodium sulphate at the rate of 1-1/2 pounds per gallon of water is advisable. A 24 deg. B. caustic soda solution is prepared and added slowly to the acidified oil with constant stirring. The mass first turns creamy, then becomes streaked, increasing in streaks as the caustic solution is poured in, and finally becomes clear and transparent. Water is now added to bring the volume to 75 gallons. The oil is now milky in appearance, but the addition of a little more soda solution restores the transparency. In some cases ammonia is used in addition to caustic soda in neutralizing the oil. Three-fourths of the amount of caustic soda required to complete the neutralization is first added and then the neutralization is completed with a one to one liquid ammonia and water solution. FOOTNOTES: [9] Seifensieder Ztg., 40, 47, 1266 (1913). [10] Seifensieder Ztg. (1913), p. 334 and 338. " " (1912), p. 1229 and 1257. [11] Seifensieder Ztg. (1912), p. 954. CHAPTER V Glycerine Recovery. The recovery of glycerine is very closely allied with the soap-making industry, because glycerine is the very valuable by-product obtained in the saponification of oils and fats. No soap plant is, therefore, fully equipped unless it has some method whereby the glycerine is recovered and the importance of recovering this product cannot be too strongly emphasized. It has already been pointed out that neutral fats or the glycerides are a combination of fatty acid with glycerine. These are split apart in the process of saponification. While by the term _saponification_ as used in soap making it is inferred that this is the combination of caustic alkalis with the fatty acids to form soap, this term is by no means limited to this method of saponification, as there are various other methods of saponifying a fat. The chemical definition of saponification is the conversion of an ester, of which glycerides are merely a certain type, into an alcohol and an acid or a salt of this acid. Thus, if we use caustic alkali as our saponifying agent for a fat or oil, we obtain the sodium or potassium salt of the higher fatty acids or soap and the alcohol, glycerine. On the other hand, if we use a mineral acid as the saponifying agent, we obtain the fatty acids themselves in addition to glycerine. While the former is by far the most generally employed for making soap, other processes consist in saponifying the fats by some method other than caustic alkalis and then converting the fatty acids into soap by either neutralizing them with sodium or potassium carbonate or hydrate. It is important to again point out here that fats and oils develop free fatty acid of themselves and that the development of this acid represents a loss in glycerine. The selection of an oil or fat for soap making should therefore to a large extent be judged as to its adaptability by the free fatty acid content, as the higher this content is, the greater is the loss in the glycerine eventually obtained. Glycerine often represents the only profit to a soap manufacturer. It is indeed necessary to determine the percentage of free fatty acid before purchasing a lot of stock to be made into soap. In taking up the question of glycerine recovery we will consider the various methods thus: 1. Where the glycerine is obtained from spent lye by saponifying the fats or oils with caustic alkali. 2. Where the glycerine is obtained by saponifying the fats or oils by some other method than the above, of which there are the following: (a) Twitchell process. (b) Saponification by lime in autoclave. (c) Saponification by acid. (d) Saponification by water in autoclave. (e) Fermentative (Enzymes). (f) Krebitz process. RECOVERY OF GLYCERINE FROM SPENT LYE. The spent lye obtained from the glycerine changes in making soap varies greatly, the quality depending upon the stock saponified and the soap maker's care in handling the operation. No two lyes run exactly alike as to proportion of the various ingredients, although they are all similar in containing the same substances either in solution or suspension. Spent lye is a water solution of mainly glycerine, free alkali either as caustic alkali or carbonate and salt, including sodium sulfate, but furthermore contains some soap and albuminous matter either in solution or suspension. Upon standing in the storage tank the greater part of the soap usually separates when the lye cools. In order to assure the greatest economical yield of glycerine by saponifying a fat with caustic soda it is necessary to obtain a proportion of three parts of water to every part of fat made into soap. Test runs have shown that this is the proper proportion and that it is not economical to greatly exceed this amount, and if a much less proportion is used the full yield of glycerine is not obtained. The spent lyes contain varying amounts of glycerine, the first change being richest in glycerine content, and this being reduced in the subsequent changes. If the lyes always run high in glycerine it is an indication that it is not all being obtained. The usual percentage is from 0.5% to 5% or even more, although the average is somewhere around 2% to 3%. The lye as it comes from the kettle should not contain any more than 0.5% to 0.6% of free alkali calculated as sodium carbonate, Na_{2}CO_{3}. If the proportion is higher than this, it shows that the saponification has been conducted with too high a proportion of alkali, a condition which should be corrected in the kettle room. An excess of free alkali does not interfere to any great extent with the successful recovery of the glycerine, but is a waste of both alkali and the acid used in neutralizing this. It is, therefore, more economical to run a strong lye over fresh stock and neutralize the alkali thus, rather than treating the lye for glycerine recovery. Before the spent lye can be run into the evaporator it is necessary to remove the albuminous impurities and soap and to neutralize the excess alkali to between exactly neutral and 0.02% alkalinity. The lye should never be fed into the evaporator in the acid condition. In order to treat the spent lyes for evaporation, they are first allowed to cool in the storage tank, after which any soap which may have separated is skimmed off and returned to the soap kettle. This lye is then pumped to the treatment tank, an ordinary tank equipped with some method of agitating the liquor, either by a mechanical stirrer, steam blower or compressed air, until it is about two feet from the top. After the lye has been skimmed off it is thoroughly agitated and a sample taken. The amount of lye in the tank is then calculated. Spent lye is about 1.09 times heavier than water, or weighs about 9 pounds to the gallon. While the sample is being tested for alkalinity it is advisable to add sulfate of alumina, which may be dissolving while the sample is being titrated. This substance should be added in the proportion of anywhere from 6 to 14 pounds per thousand pounds of lye, depending upon the amount of impurities contained therein. For a clean lye six pounds per thousand is sufficient, but for an impure lye a greater quantity is necessary. The sulfate of alumina used should be free from arsenic and sulfides and should contain a minimum amount of grit (silica), as grit reduces the life of the pump valves. This may be estimated with sufficient accuracy by rubbing the filtered-off portions, insoluble in water between the fingers and a plate of glass. The object of adding the sulfate of alumina is to transform the soap contained in the lye into the insoluble aluminum soaps, and at the same time to coagulate the albuminous impurities. It must be remembered that the sulfate of alumina is added only for the fresh lye put into the tank. Thus if there were 10,000 pounds of lye in the treating tank when the fresh lye was run in, and 50,000 pounds when the tank is filled, adding nine pounds of sulfate of alumina per thousand of lye, only 360 pounds would be added or enough for 40,000 pounds. Sulfate of alumina neutralizes one-third of its weight of caustic. To determine the alkali in the sample, 10 cubic centimeters are pipetted into a beaker, a little distilled water added, then 3 or 4 drops of phenolphthalein indicator. From a burette, quarter normal (N/4) sulfuric acid is added until the pink color is just discharged. When this point is reached 4 to 5 c. c. more of acid are added and the solution is boiled to expel the carbon dioxide. Should the solution turn pink, it is necessary to add more acid. After having boiled for 3 to 4 minutes, N/4 caustic soda is added until the pink color just returns and the amount of caustic soda used is read on the burette. The difference between the number of cubic centimeters of N/4 sulfuric acid and N/4 caustic soda gives the amount of alkali in the sample. By using a 10 c. c. sample and N/4 sulfuric acid and N/4 caustic soda each c. c. obtained by the difference of these two solutions is equal to one-tenth of one per cent. (0.1%) of the total alkali in the lye. As an example, say we first used 7.7 c. c. of N/4 sulfuric acid to just discharge the pink, then added 4 c. c. more, or 11.7 c. c. in total. After boiling it required 5.3 c. c. to bring back a slight pink, the total alkalinity would be 11.7 c. c. - 5.3 c. c. = 6.4 c. c., or 0.64% total alkali in the lye in terms of caustic soda. If there were 40,000 pounds of lye to be treated then we should have to neutralize: 40,000 � .0064 = 256 lbs. alkali. Since sulfate of alumina neutralizes one-third of its weight in caustic, and there are say 9 lbs. of this added per thousand pounds of lye we would add 40,000 � 9 = 360 lbs. of sulfate of alumina. This would neutralize 360 � 1/3 = 120 lbs of alkali. There are then 256 - 120 = 136 lbs. of alkali still to be neutralized. If 60° B. sulfuric acid is used it requires about 1.54 lbs. of acid to one pound of caustic. Therefore to neutralize the caustic soda remaining it requires: 136 � 1.54 = 209.44 lbs. 60° B. sulfuric acid to neutralize the total alkali in the 40,000 pounds of spent lye. The acid is added and the lye well stirred, after which another sample is taken and again titrated as before. From this titration the amount of acid to be added is again calculated and more acid is added if necessary. Should too much acid have been added, caustic soda solution is added until the lye is between exactly neutral and 0.02% alkaline. The filtered lyes at this stage have a slight yellowish cast. To be sure that the lyes are treated correctly the precipitation test is advisable. To carry this out filter about 50 c. c. of the treated lye and divide into two portions in a test tube. To one portion add ammonia drop by drop. If a cloudiness develops upon shaking, more alkali is added to the lye in the tank. To the other portion add a few drops of 1 to 5 sulfuric acid and shake the test tube. If a precipitate develops or the solution clouds, more acid is needed. When the lyes are treated right no cloudiness should develop either upon adding ammonia or the dilute acid. The properly treated lye is then run through the filter press while slightly warm and the filtered lye is fed to the evaporator from the filtered lye tank. The lye coming from the filter press should be clear and have a slight yellowish cast. As the pressure increases it is necessary to clean the press or some of the press cake will pass through the cloths. Where sodium silicate is used as a filler, the silicate scrap should never be returned to the soap kettle until the glycerine lyes have been withdrawn. This practice of some soapmakers is to be strongly censured, as it causes decided difficulty in filtering the lye, since during the treatment of the lye, free silicic acid in colloidal form is produced by the decomposition of the sodium silicate by acid. This often prevents filtering the treated lye even at excess pressure and at its best retards the filtering. As to the filter press cake, this may be best thrown away in a small factory. Where, however, the output of glycerine is very large it pays to recover both the fatty acids and alumina in the press cakes. In some cases, especially when the lyes are very dirty and the total residue in the crude glycerine runs high, for which there is a penalty usually attached, a double filtration of the lye is advisable. This is carried out by first making the lye slightly acid in reaction by the addition of alum and acid, then filtering. This filtered lye is then neutralized to the proper point with caustic, as already described, and passed through the filter press again. While in the method of treating the lyes as given sulfuric acid is used for neutralizing, some operators prefer to use hydrochloric acid, as this forms sodium chloride or common salt, whereas sulfuric acid forms sodium sulfate, having 3/5 the graining power of salt, which eventually renders the salt useless for graining the soap, as the percentage of sodium sulfate increases in the salt. When the salt contains 25 per cent. sodium sulfate it is advisable to throw it away. Sulfuric acid, however, is considerably cheaper than hydrochloric and this more than compensates the necessity of having to eventually reject the recovered salt. It may here also be mentioned that recovered salt contains 5-7 per cent. glycerine which should be washed out in the evaporator before it is thrown away. The following tables give the approximate theoretical amounts of acids of various strengths required to neutralize one pound of caustic soda: For 1 pound of caustic soda-- 3.25 lbs. 18° B. hydrochloric (muriatic) acid are required. 2.92 " 20° B. " " " " " 2.58 " 22° B. " " " " " For 1 pound of caustic soda-- 1.93 lbs. 50° B. sulphuric acid are required. 1.54 " 60° B. " " " " 1.28 " 66° B. " " " " It is, of course, feasible to neutralize the spent lye without first determining the causticity by titrating a sample and this is often the case. The operator under such conditions first adds the sulfate of alumina, then the acid, using litmus paper as his indicator. Comparatively, this method of treatment is much slower and not as positive, as the amount of acid or alkali to be added is at all times uncertain, for in the foaming of the lyes their action on litmus is misleading. After the lye has been filtered to the filtered lye tank it is fed to the evaporator, the method of operation of which varies somewhat with different styles or makes. When it first enters the evaporator the lye is about 11°-12° B. After boiling the density will gradually rise to 27° B. and remain at this gravity for some time and during which time most of the salt is dropped out in the salt filter. As the lye concentrates the gravity gradually rises to 28°-30° B., which is half crude glycerine and contains about 60 per cent. glycerine. Some operators carry the evaporation to this point and accumulate a quantity of half crude before going on to crude. After half crude is obtained the temperature on the evaporator increases, the vacuum increases and the pressure on the condensation drain goes up (using the same amount of live steam). As the liquor grows heavier the amount of evaporation is less, and less steam is required necessitating the regulation of the steam pressure on the drum. When a temperature of 210° F. on the evaporator, with 26 or more inches vacuum on the pump is arrived at, the crude stage has been reached and the liquor now contains about 80 per cent. glycerine in which shape it is usually sold by soap manufacturers. A greater concentration requires more intricate apparatus. After settling a day in the crude tank it is drummed. Crude glycerine (about 80 per cent. glycerol) free from salt is 33° B., or has a specific gravity of 1.3. A sample boiled in an open dish boils at a temperature of 155° C. or over. TWITCHELL PROCESS. The Twitchell process of saponification consists of causing an almost complete cleavage of fats and oils by the use of the Twitchell reagent or saponifier, a sulfo-aromatic compound. This is made by the action of concentrated sulfuric acid upon a solution of oleic acid or stearic acid in an aromatic hydrocarbon. From 0.5 per cent. to 3 per cent. of the reagent is added and saponification takes place from 12-48 hours by heating in a current of live steam. The reaction is usually accelerated by the presence of a few per cent. of free fatty acids as a starter. Recently the Twitchell double reagent has been introduced through which it is claimed that better colored fatty acids are obtained and the glycerine is free from ash. The advantages claimed for the Twitchell process as outlined by Joslin[12] are as follows: 1. All the glycerine is separated from the stock before entering the kettle, preventing loss of glycerine in the soap and removing glycerine from spent lye. 2. The liquors contain 15-20 per cent. glycerine whereas spent lyes contain but 3-5 per cent. necessitating less evaporation and consequently being more economical in steam, labor and time. 3. No salt is obtained in the liquors which makes the evaporation cheaper and removes the cause of corrosion of the evaporator; also saves the glycerine retained by the salt. 4. The glycerine liquors are purer and thus the treatment of the lyes is cheaper and simpler and the evaporation less difficult. 5. The glycerine can readily be evaporated to 90 per cent. crude rather than 80 per cent. crude, thus saving drums, labor in handling and freight. The glycerine furthermore receives a higher rating and price, being known as saponification crude which develops no glycols in refining it. 6. The fatty acids obtained by the Twitchell saponifier may be converted into soap by carbonates, thus saving cost in alkali. 7. There is a decrease in the odor of many strong smelling stocks. 8. The glycerine may be obtained from half boiled and cold made soaps as well as soft (potash) soaps. While the advantages thus outlined are of decided value in the employment of the Twitchell process, the one great disadvantage is that the fatty acids obtained are rather dark in color and are not satisfactorily employed for the making of a soap where whiteness of color is desired. To carry out the process the previously heated oil or fat to be saponified is run into a lead lined tank. As greases and tallow often contain impurities a preliminary treatment with sulfuric acid is necessary. For a grease 1.25 per cent. of half water and half 66° B. sulfuric acid is the approximate amount. The undiluted 66° B. acid should never be added directly, as the grease would be charred by this. The grease should be agitated by steam after the required percentage of acid, calculated on the weight of the grease, has been added. The wash lye coming off should be 7°-10° B. on a good clean grease or 15°-22° B. on cotton oil or a poor grease. As has been stated the grease is heated before the acid is added or the condensation of the steam necessitates the addition of more acid. After having boiled for 1-2 hours the grease is allowed to settle for 12 hours and run off through a swivel pipe. After the grease has been washed, as just explained, and settled, it is pumped into a covered wooden tank containing an open brass coil. Some of the second lye from a previous run is usually left in this tank and the grease pumped into this. The amount of this lye should be about one-third to one-half the weight of the grease so that there is about 60 per cent. by weight of grease in the tank after 24 hours boiling. Where occasions arise when there is no second lye about 50 per cent. by weight of distilled water to the amount of grease is run into the tank to replace the lye. The saponifier is then added through a glass or granite ware funnel after the contents of the tank have been brought to a boil. If the boiling is to be continued 48 hours, 1 per cent. of saponifier is added. For 24 hours boiling add 1.5 per cent. The boiling is continued for 24-48 hours allowing 18 inches for boiling room or the grease will boil over. After boiling has continued the required length of time the mass is settled and the glycerine water is drawn off to the treatment tank. Should a permanent emulsion have formed, due to adding too great an amount of saponifier, a little sulfuric acid (0.1 per cent.-0.3 per cent.) will readily break this. During the time this is being done the space between the grease and the cover on the tank is kept filled with steam as contact with the air darkens the fatty acids. To the grease remaining in the tank distilled water (condensed water from steam coils) to one-half its volume is added and the boiling continued 12-24 hours. The grease is then settled and the clear grease run off through a swivel pipe. A layer of emulsion usually forms between the clear grease and lye so that it may easily be determined when the grease has all been run off. To prevent discoloration of the fatty acids it is necessary to neutralize the lye with barium carbonate. The amount of this to be added depends upon the percentage of saponifier used. About 1/10 the weight of saponifier is the right amount. The barium carbonate is added through the funnel at the top of the tank mixed with a little water and the lye tested until it is neutral to methyl orange indicator. When the fatty acids are thus treated they will not darken upon exposure to the air when run off. Fresh grease is now pumped into the lye or water remaining in the tank and the process repeated. The glycerine water or first lye is run to the treatment tank, the fat skimmed off and neutralized with lime until it shows pink with phenolphthalein, after having been thoroughly boiled with steam. About 0.25 per cent. lime is the proper amount to add. The mixture is then allowed to settle and the supernatant mixture drawn off and run to the glycerine evaporator feed tank. The lime which holds considerable glycerine is filtered and the liquor added to the other. The evaporation is carried out in two stages. The glycerine water is first evaporated to about 60 per cent. glycerol, then dropped into a settling tank to settle out the calcium sulfate. The clear liquor is then evaporated to crude (about 90 per cent. glycerine) and the sediment filtered and also evaporated to crude. As to the amount of saponifier to use on various stocks, this is best determined by experiment as to how high a percentage gives dark colored fatty acids. For good stock such as clean tallow, prime cottonseed oil, corn oil, cocoanut oil and stock of this kind 0.75 per cent. saponifier is sufficient. For poorer grades of tallow, house grease, poor cottonseed oil, etc., 1 per cent. saponifier is required and for poorer grade greases higher percentages. The percentage of fatty acids developed varies in various stocks, and also varies with the care that the operation is carried out, but is usually between 85 per cent.-95 per cent. Due to the water taken up in the saponification process there is a yield of about 103 pounds of fatty acids and glycerine for 100 pounds of fat. The Twitchell reagent has undoubtedly caused a decided advance in the saponification of fats and oils and has been of great value to the soap manufacturer, because with a small expenditure it is possible to compete with the much more expensive equipment necessary for autoclave saponification. The drawback, however, has been that the reagent imparted a dark color to the fatty acids obtained, due to decomposition products forming when the reagent is made, and hence is not suitable for use in soaps where whiteness of color is desired. There have recently been two new reagents introduced which act as catalyzers in splitting fats, just as the Twitchell reagent acts, but the fatty acids produced by the cleavage are of good color. The saponification, furthermore, takes place more rapidly. These are the Pfeilring reagent and Kontact reagent. The Pfeilring reagent is very similar to the Twitchell reagent, being made from hydrogenated castor oil and naphthalene by sulfonation with concentrated sulfuric acid. It is manufactured in Germany and is being extensively used in that country with good success. The Kontact or Petroff reagent, discovered by Petroff in Russia, is made from sulfonated mineral oils. Until very recently it has only been manufactured in Europe, but now that it has been found possible to obtain the proper mineral constituent from American petroleum, it is being manufactured in this country, and it is very probable that it will replace the Twitchell reagent because of the advantages derived by using it, as compared to the old Twitchell reagent. The method and equipment necessary for employing either the Pfeilring or Kontact reagents is exactly the same as in using the Twitchell process. AUTOCLAVE SAPONIFICATION. While the introduction of the Twitchell process to a great extent replaced the autoclave method of saponification for obtaining fatty acids for soap making, the autoclave method is also used. This process consists in heating the previously purified fat or oil in the presence of lime and water, or water only, for several hours, which causes a splitting of the glycerides into fatty acids and glycerine. The advantage of autoclave saponification over the Twitchell process is that a greater cleavage of the fats and oils results in less time and at a slightly less expense. The glycerine thus obtained is also purer and of better color than that obtained by Twitchelling the fats. An autoclave or digestor consists of a strongly constructed, closed cylindrical tank, usually made of copper, and is so built as to resist internal pressure. The digestor is usually 3 to 5 feet in diameter and from 18 to 25 feet high. It may be set up horizontally or vertically and is covered with an asbestos jacket to retain the heat. Various inlets and outlets for the fats, steam, etc., as well as a pressure gauge and safety valve are also a necessary part of the equipment. LIME SAPONIFICATION. The saponification in an autoclave is usually carried out by introducing the fats into the autoclave with a percentage of lime, magnesia or zinc oxide, together with water. If the fats contain any great amount of impurities, it is first necessary to purify them either by a treatment with weak sulfuric acid, as described under the Twitchell process, or by boiling them up with brine and settling out the impurities from the hot fat. To charge the autoclave a partial vacuum is created therein by condensation of steam just before running the purified oil in from an elevated tank. The required quantity of unslaked lime, 2 to 4 per cent. of the weight of the fat, is run in with the molten fat, together with 30 per cent. to 50 per cent. of water. While 8.7 per cent. lime is theoretically required, practice has shown that 2 per cent. to 4 per cent. is sufficient. The digestor, having been charged and adjusted, steam is turned on and a pressure of 8 to 10 atmospheres maintained thereon for a period of six to ten hours. Samples of the fat are taken at various intervals and the percentage of free fatty acids determined. When the saponification is completed the contents of the autoclave are removed, usually by blowing out the digestor into a wooden settling tank, or by first running off the glycerine water and then blowing out the lime, soap and fatty acids. The mass discharged from the digestor separates into two layers, the upper consisting of a mixture of lime soap or "rock" and fatty acids, and the lower layer contains the glycerine or "sweet" water. The glycerine water is first run off through a clearing tank or oil separator, if this has not been done directly from the autoclave, and the mass remaining washed once or twice more with water to remove any glycerine still retained by the lime soap. The calculated amount of sulfuric acid to decompose the lime "rock" is then added, and the mass agitated until the fatty acids contained therein are entirely set free. Another small wash is then given and the wash water added to the glycerine water already run off. The glycerine water is neutralized with lime, filtered and concentrated as in the Twitchell process. Due to the difficulties of working the autoclave saponification with lime, decomposing the large amount of lime soap obtained and dealing with much gypsum formed thereby which collects as a sediment and necessitates cleaning the tanks, other substances are used to replace lime. Magnesia, about 2 per cent. of the weight of the fat, is used and gives better results than lime. One-half to 1 per cent. of zinc oxide of the weight of the fat is even better adapted and is now being extensively employed for this purpose. In using zinc oxide it is possible to recover the zinc salts and use them over again in the digestor, which makes the process as cheap to work as with lime, with far more satisfactory results. ACID SAPONIFICATION. While it is possible to saponify fats and oils in an autoclave with the addition of acid to the fat, unless a specially-constructed digestor is built, the action of the acid on the metal from which the autoclave is constructed prohibits its use. The acid saponification is therefore carried out by another method. The method of procedure for acid saponification, therefore, is to first purify the fats with dilute acid as already described. The purified, hot or warm, dry fat is then run to a specially-built acidifier or a lead-lined tank and from 4 per cent. to 6 per cent. of concentrated sulfuric acid added to the fat, depending upon its character, the degree of saponification required, temperature and time of saponification. A temperature of 110 degrees C. is maintained and the mass mixed from four to six hours. The tank is then allowed to settle out the tar formed during the saponification, and the fatty acids run off to another tank and boiled up about three times with one-third the amount of water. The water thus obtained contains the glycerine, and after neutralization is concentrated. AQUEOUS SAPONIFICATION. While lime or a similar substance is ordinarily used to aid in splitting fats in an autoclave, the old water process is still used. This is a convenient, though slower and more dangerous method, of producing the hydrolysis of the glyceride, as well as the simplest in that fatty acids and glycerine in a water solution are obtained. The method consists in merely charging the autoclave with fats and adding about 30 per cent. to 40 per cent. of their weight of water, depending on the amount of free fatty acid and subjecting the charge to a pressure of 150 to 300 pounds, until the splitting has taken place. This is a much higher pressure than when lime is used and therefore a very strong autoclave is required. Since fatty acids and pure glycerine water are obtained no subsequent treatment of the finished charge is necessary except separating the glycerine water and giving the fatty acids a wash with water to remove all the glycerine from them. SPLITTING FATS WITH FERMENTS. In discussing the causes of rancidity of oils and fats it was pointed out that the initial splitting of these is due to enzymes, organized ferments. In the seeds of the castor oil plant, especially in the protoplasm of the seed, the enzyme which has the property of causing hydrolysis of the glycerides is found. The ferment from the seeds of the castor oil plant is now extracted and used upon a commercial basis for splitting fats. The equipment necessary to carry out this method of saponification is a round, iron, lead-lined tank with a conical bottom, preferably about twice as long as it is wide. Open and closed steam coils are also necessary in the tank. The oils are first heated and run into this tank. The right temperature to heat these to is about 1 degree to 2 degrees above their solidification point. For liquid oils 23 degrees C. is the proper heat as under 20 degrees C. the cleavage takes place slowly. Fats titering 44 degrees C. or above must be brought down in titer by mixing with them oils of a lower titer as the ferment or enzyme is killed at about 45 degrees C. and thus loses its power of splitting. It is also necessary to have the fat in the liquid state or the ferment does not act. The proper temperature must be maintained with dry steam. It is, of course, necessary to add water, which may be any kind desired, condensed, water from steam coils, well, city, etc. From 30 per cent. to 40 per cent., on the average 35 per cent. of water is added, as the amount necessary is regulated so as to not dilute the glycerine water unnecessarily. To increase the hydrolysis a catalyzer, some neutral salt, usually manganese sulfate is added in the proportion of 0.15 per cent. appears to vary directly as the saponification number of the fat or oil. The approximate percentages of fermentive substance to be added to various oils and fats follow: Cocoanut oil 8 % Palm Kernel oil 8 % Cottonseed oil 6-7 % Linseed oil 4-5 % Tallow oil 8-10% The oil, water, manganese sulfate and ferment having been placed in the tank in the order named, the mixture is agitated with air for about a quarter of an hour to form an even emulsion, in which state the mass is kept by stirring occasionally with air while the saponification is taking place. A temperature is maintained a degree or two above the titer point of the fat with closed steam which may be aided by covering the tank for a period of 24 to 48 hours. The splitting takes place rapidly at first, then proceeds more slowly. In 24 hours 80 per cent. of the fats are split and in 48 hours 85 per cent. to 90 per cent. When the cleavage has reached the desired point the mass is heated to 80 degrees-85 degrees C. with live or indirect steam while stirring with air. Then 0.1 per cent.-0.15 per cent of concentrated sulfuric acid diluted with water is added to break the emulsion. When the emulsion is broken the glycerine water is allowed to settle out and drawn off. The glycerine water contains 12 per cent. to 25 per cent. glycerine and contains manganese sulfate, sulfuric acid and albuminous matter. Through neutralization with lime at boiling temperature and filtration the impurities can almost all be removed after which the glycerine water may be fed to the evaporator. Should it be desired to overcome the trouble due to the gypsum formed in the glycerine, the lime treatment may be combined with a previous treatment of the glycerine water with barium hydrate to remove the sulfuric acid, then later oxalic acid to precipitate the lime. The fatty acids obtained by splitting with ferments are of very good color and adaptable for soap making. KREBITZ PROCESS. The Krebitz process which has been used to some extent in Europe is based upon the conversion of the fat or oil into lime soap which is transformed into the soda soap by the addition of sodium carbonate. To carry out the process a convenient batch of, say, 10,000 pounds of fat or oil, is run into a shallow kettle containing 1,200 to 1,400 pounds of lime previously slaked with 3,700 to 4,500 pounds of water. The mass is slowly heated with live steam to almost boiling until an emulsion is obtained. The tank is then covered and allowed to stand about 12 hours. The lime soap thus formed is dropped from the tank into the hopper of a mill, finely ground and conveyed to a leeching tank. The glycerine is washed out and the glycerine water run to a tank for evaporation. The soap is then further washed and these washings are run to other tanks to be used over again to wash a fresh batch of soap. About 150,000 pounds of water will wash the soap made from 10,000 pounds of fat which makes between 15,000 and 16,000 pounds of soap. The first wash contains approximately 10 per cent. glycerine and under ordinary circumstances this only need be evaporated for glycerine recovery. After extracting the glycerine the soap is slowly introduced into a boiling solution of sodium carbonate or soda ash and boiled until the soda has replaced the lime. This is indicated by the disappearance of the small lumps of lime soap. Caustic soda is then added to saponify the fat not converted by the lime saponification. The soap is then salted out and allowed to settle out the calcium carbonate. This drops to the bottom of the kettle as a heavy sludge entangling about 10 per cent. of the soap. A portion of this soap may be recovered by agitating the sludge with heat and water, pumping the soap off the top and filtering the remaining sludge. While the soap thus obtained is very good, the percentage of glycerine recovered is greatly increased and the cost of alkali as carbonate is less. The disadvantages are many. Large quantities of lime are required; it is difficult to recover the soap from the lime sludge; the operations are numerous prior to the soap making proper and rather complicated apparatus is required. DISTILLATION OF FATTY ACIDS. The fatty acids obtained by various methods of saponification may be further improved by distillation. In order to carry out this distillation, two methods may be pursued, first, the continuous method, whereby the fatty acids are continually distilled for five to six days, and, second, the two phase method, whereby the distillation continues for 16 to 20 hours, after which the residue is drawn off, treated with acid, and its distillate added to a fresh charge of fatty acids. The latter method is by far the best, since the advantages derived by thus proceeding more than compensate the necessity of cleaning the still. Better colored fatty acids are obtained; less unsaponifiable matter is contained therein; there is no accumulation of impurities; the amount of neutral fat is lessened because the treatment of the tar with acid causes a cleavage of the neutral fat and the candle tar or pitch obtained is harder and better and thus more valuable. The stills are usually built of copper, which are heated by both direct fire and superheated steam. Distillation under vacuum is advisable. To begin the distilling operation, the still is first filled with dry hot fatty acids to the proper level. Superheated steam is then admitted and the condenser is first heated to prevent the freezing of the fatty acids, passing over into same. When the temperature reaches 230 deg. C. the distillation begins. At the beginning, the fatty acids flow from the condenser, an intense green color, due to the formation of copper soaps produced by the action of the fatty acids on the copper still. This color may easily be removed by treating with dilute acid to decompose the copper soaps. In vacuum distillation, the operation is begun without the use of vacuum. Vacuum is introduced only when the distillation has proceeded for a time and the introduction of this must be carefully regulated, else the rapid influence of vacuum will cause the contents of the still to overflow. When distillation has begun a constant level of fatty acids is retained therein by opening the feeding valve to same, and the heat is so regulated as to produce the desired rate of distillation. As soon as the distillate flows darker and slower, the feeding valve to the still is shut off and the distillation continued until most of the contents of the still are distilled off, which is indicated by a rise in the temperature. Distillation is then discontinued, the still shut down, and in about an hour the contents are sufficiently cool to be emptied. The residue is run off into a proper receiving vessel, treated with dilute acid and used in the distillation of tar. In the distillation of tar the same method as the above is followed, only distillation proceeds at a higher temperature. The first portion and last portion of the distillate from tar are so dark that it is necessary to add them to a fresh charge of fatty acids. By a well conducted distillation of tar about 50 per cent. of the fatty acids from the tar can be used to mix with the distilled fatty acids. The residue of this operation called stearine pitch or candle tar consists of a hard, brittle, dark substance. Elastic pitch only results where distillation has been kept constant for several days without interrupting the process, and re-distilling the tar. In a good distillation the distillation loss is 0.5 to 1.5% and loss in pitch 1.5%. Fatty acids which are not acidified deliver about 3% of pitch. Very impure fats yield even a higher percentage in spite of acidifying. For a long time it was found impossible to find any use for stearine pitch, but in recent years a use has been found for same in the electrical installation of cables. FOOTNOTES: [12] Journ. Ind. Eng. Chem. (1909), I, p. 654. CHAPTER VI Analytical Methods. While it is possible to attain a certain amount of efficiency in determining the worth of the raw material entering into the manufacture of soap through organoleptic methods, these are by no means accurate. It is, therefore, necessary to revert to chemical methods to correctly determine the selection of fats, oil or other substances used in soap making, as well as standardizing a particular soap manufactured and to properly regulate the glycerine recovered. It is not our purpose to cover in detail the numerous analytical processes which may be employed in the examination of fats and oils, alkalis, soap and glycerine, as these are fully and accurately covered in various texts, but rather to give briefly the necessary tests which ought to be carried out in factories where large amounts of soap are made. Occasion often arises where it is impossible to employ a chemist, yet it is possible to have this work done by a competent person or to have someone instruct himself as just how to carry out the more simple analyses, which is not a very difficult matter. The various standard solutions necessary to carrying out the simpler titrations can readily be purchased from dealers in chemical apparatus and it does not take extraordinary intelligence for anyone to operate a burette, yet in many soap plants in this country absolutely no attention is paid to the examining of raw material, though many thousand pounds are handled annually, which, if they were more carefully examined would result in the saving of much more money than it costs to examine them or have them at least occasionally analyzed. ANALYSIS OF FATS AND OILS. In order to arrive at proper results in the analysis of a fat or oil, it is necessary to have a proper sample. To obtain this a sample of several of the packages of oil or fat is taken and these mixed or molten together into a composite sample which is used in making the tests. If the oil or fat is solid, a tester is used in taking the sample from the package and if they are liquid, it is a simple matter to draw off a uniform sample from each package and from these to form a composite sample. In purchasing an oil or fat for soap making, the manufacturer is usually interested in the amount of free fatty acid contained therein, of moisture, the titer, the percentage of unsaponifiable matter and to previously determine the color of soap which will be obtained where color is an object. DETERMINATION OF FREE FATTY ACIDS. Since the free fatty acid content of a fat or oil represents a loss of glycerine, the greater the percentage of free fatty acid, the less glycerine is contained in the fat or oil, it is advisable to purchase a fat or oil with the lower free acid, other properties and the price being the same. While the mean molecular weight of the mixed free fatty acids varies with the same and different oils or fats and should be determined for any particular analysis for accuracy, the free fatty acid is usually expressed as oleic acid, which has a molecular weight of 282. To carry out the analysis 5 to 20 grams of the fat are weighed out into an Erlenmeyer flask and 50 cubic centimeters of carefully neutralized alcohol are added. In order to neutralize the alcohol add a few drops of phenolphthalein solution to same and add a weak caustic soda solution drop by drop until a very faint pink color is obtained upon shaking or stirring the alcohol thoroughly. The mixture of fat and neutralized alcohol is then heated to boiling and titrated with tenth normal alkali solution, using phenolphthalein as an indicator. As only the free fatty acids are readily soluble in the alcohol and the fat itself only slightly mixes with it, the flask should be well agitated toward the end of the titration. When a faint pink color remains after thoroughly agitating the flask the end point is reached. In order to calculate the percentage of free fatty acid as oleic acid, multiply the number of cubic centimeters of tenth normal alkali used as read on the burette by 0.0282 and divide by the number of grams of fat taken for the determination and multiply by 100. When dark colored oils or fats are being titrated it is often difficult to obtain a good end point with phenolphthalein. In such cases about 2 cubic centimeters of a 2 per cent. alcoholic solution of Alkali Blue 6 B is recommended. Another method of directly determining the free fatty acid content of tallow or grease upon which this determination is most often made is to weigh out into an Erlenmeyer flask exactly 5.645 grams of a sample of tallow or grease. Add about 75 cubic centimeters of neutralized alcohol. Heat until it boils, then titrate with tenth normal alkali and divide the reading by 2, which gives the percentage of free fatty acid as oleic. If a fifth normal caustic solution is used, the reading on the burette gives the percentage of free fatty acid directly. This method, while it eliminates the necessity of calculation, is troublesome in that it is difficult to obtain the exact weight of fat. MOISTURE. To calculate the amount of moisture contained in a fat or oil 5 to 10 grams are weighed into a flat bottom dish, together with a known amount of clean, dry sand, if it is so desired. The dish is then heated over a water bath, or at a temperature of 100-110 degs. C., until it no longer loses weight upon drying and reweighing the dish. One hour should elapse between the time the dish is put on the water bath and the time it is taken off to reweigh. The difference between the weight of the dish is put on the water bath and the time it is taken off when it reaches a constant weight is moisture. This difference divided by the original weight of the fat or oil � 100 gives the percentage of moisture. When highly unsaturated fats or oils are being analyzed for moisture, an error may be introduced either by the absorption of oxygen, which is accelerated at higher temperature, or by the formation of volatile fatty acids. The former causes an increase in weight, the latter causes a decrease. To obviate this, the above operation of drying should be carried out in the presence of some inert gas like hydrogen, carbon dioxide, or nitrogen. TITER. The titer of a fat or oil is really an indication of the amount of stearic acid contained therein. The titer, expressed in degrees Centigrade, is the solidification point of the fatty acids of an oil or fat. In order to carry out the operation a Centigrade thermometer graduated in one or two-tenths of a degree is necessary. A thermometer graduated between 10 degs. centigrade to 60 degs. centigrade is best adapted and the graduations should be clear cut and distinct. To make the determination about 30 grams of fat are roughly weighed in a metal dish and 30-40 cubic centimeters of a 30 per cent. (36 degs. Baumé) solution of sodium hydroxide, together with 30-40 cubic centimeters of alcohol, denatured alcohol will do, are added and the mass heated until saponified. Heat over a low flame or over an asbestos plate until the soap thus formed is dry, constantly stirring the contents of the dish to prevent burning. The dried soap is then dissolved in about 1000 cubic centimeters of water, being certain that all the alcohol has been expelled by boiling the soap solution for about half an hour. When the soap is in solution add sufficient sulphuric acid to decompose the soap, approximately 100 cubic centimeters of 25 degs. Baumé sulphuric acid, and boil until the fatty acids form a clear layer on top of the liquid. A few pieces of pumice stone put into the mixture will prevent the bumping caused by boiling. Siphon off the water from the bottom of the dish and wash the fatty acids with boiling water until free from sulphuric acid. Collect the fatty acids in a small casserole or beaker and dry them over a steam bath or drying oven at 110 degs. Centigrade. When the fatty acids are dry, cool them to about 10 degs. above the titer expected and transfer them to a titer tube or short test tube which is firmly supported by a cork in the opening of a salt mouth bottle. Hang the thermometer by a cord from above the supported tube so it reaches close to the bottom when in the titer tube containing the fatty acids and so that it may be used as a stirrer. Stir the mass rather slowly, closely noting the temperature. The temperature will gradually fall during the stirring operation and finally remain stationary for half a minute or so then rise from 0.1 to 0.5 degs. The highest point to which the mercury rises after having been stationary is taken as the reading of the titer. DETERMINATION OF UNSAPONIFIABLE MATTER. In order to determine the unsaponifiable matter in fats and oils they are first saponified, then the unsaponifiable, which consists mainly of hydrocarbons and the higher alcohols cholesterol or phytosterol, is extracted with ether or petroleum ether, the ether evaporated and the residue weighed as unsaponifiable. To carry out the process first saponify about 5 grams of fat or oil with an excess of alcoholic potassium hydrate, 20-30 cubic centimeters of a 1 to 10 solution of potassium hydroxide in alcohol until the alcohol is evaporated over a steam bath. Wash the soap thus formed into a separatory funnel of 200 cubic centimeters capacity with 80-100 cubic centimeters water. Then add about 60 cubic centimeters of ether, petroleum ether or 86 degs. gasoline and thoroughly shake the funnel to extract the unsaponifiable. Should the two layers not separate readily, add a few cubic centimeters of alcohol, which will readily cause them to separate. Draw off the watery solution from beneath and wash the ether with water containing a few drops of sodium hydrate and run to another dish. Pour the watery solution into the funnel again and repeat the extraction once or twice more or until the ether shows no discoloration. Combine the ether extractions into the funnel and wash with water until no alkaline reaction is obtained from the wash water. Run the ether extract to a weighed dish, evaporate and dry rapidly in a drying oven. As some of the hydrocarbons are readily volatile at 100 degs. Centigrade, the drying should not be carried on any longer than necessary. The residue is then weighed and the original weight of fat taken divided into the weight of the residue � 100 gives the percentage unsaponifiable. TEST FOR COLOR OF SOAP. It is often desirable to determine the color of the finished soap by a rapid determination before it is made into soap. It often happens, especially with the tallows, that a dark colored sample produces a light colored soap, whereas a bleached light colored tallow produces a soap off shade. To rapidly determine whether the color easily washes out of the tallow with lye, 100 cubic centimeters of tallow are saponified in an enameled or iron dish with 100 cubic centimeters of 21 degs. Baumé soda lye and 100 cubic centimeters of denatured alcohol. Continue heating over a wire gauze until all the alcohol is expelled and then add 50 cubic centimeters of the 21 degs. Baumé lye to grain the soap. Allow the lyes to settle and with an inverted pipette draw off the lyes into a test tube or bottle. Close the soap with 100 cubic centimeters of hot water and when closed again grain with 50 cubic centimeters of the lye by just bringing to a boil over an open flame. Again allow the lyes to settle and put aside a sample of the lye for comparison. Repeat the process of closing, graining and settling and take a sample of lye. If the lye is still discolored repeat the above operations again or until the lye is colorless. Ordinarily all the color will come out with the third lye. The soap thus obtained contains considerable water which makes it appear white. The soap is, therefore, dried to about 15 per cent. moisture and examined for color. The color thus obtained is a very good criterion as to what may be expected in the soap kettle. By making the above analyses of fats or oils the main properties as to their adaptability for being made into soap are determined. In some cases, especially where adulteration or mixtures of oils are suspected, it is necessary to further analyze same. The methods of carrying out these analyses are fully covered by various texts on fats and oils and we will not go into details regarding the method of procedure in carrying these out. TESTING OF ALKALIS USED IN SOAP MAKING. The alkalis entering into the manufacture of soap such as caustic soda or sodium hydroxide, caustic potash or potassium hydrate, carbonate of soda or sodium carbonate, carbonate of potash or potassium carbonate usually contain impurities which do not enter into combination with the fats or fatty acids to form soap. It is out of the question to use chemically pure alkalis in soap making, hence it is often necessary to determine the alkalinity of an alkali. It may again be pointed out that in saponifying a neutral fat or oil only caustic soda or potash are efficient and the carbonate contained in these only combines to a more or less extent with any free fatty acids contained in the oils or fats. Caustic soda or potash or lyes made from these alkalis upon exposure to the air are gradually converted into sodium or potassium carbonate by the action of the carbon dioxide contained in the air. While the amount of carbonate thus formed is not very great and is greatest upon the surface, all lyes as well as caustic alkalis contain some carbonate. This carbonate introduces an error in the analysis of caustic alkalis when accuracy is required and thus in the analysis of caustic soda or potash it is necessary to remove the carbonate when the true alkalinity as sodium hydroxide or potassium hydroxide is desired. This may be done by titration in alcohol which has been neutralized. In order to determine the alkalinity of any of the above mentioned alkalis, it is first necessary to obtain a representative sample of the substance to be analyzed. To do this take small samples from various portions of the package and combine them into a composite sample. Caustic potash and soda are hygroscopic and samples should be weighed at once or kept in a well stoppered bottle. Sodium or potassium carbonate can be weighed more easily as they do not rapidly absorb moisture from the air. To weigh the caustic soda or potash place about five grams on a watch glass on a balance and weigh as rapidly as possible. Wash into a 500 cubic centimeter volumetric flask and bring to the mark with distilled water. Pipette off 50 cubic centimeters into a 200 cubic centimeter beaker, dilute slightly with distilled water, add a few drops of methyl orange indicator and titrate with normal acid. For the carbonates about 1 gram may be weighed, washed into a 400 cubic centimeter beaker, diluted with distilled water, methyl orange indicator added and titrated with normal acid. It is advisable to use methyl orange indicator in these titrations as phenolphthalein is affected by the carbon dioxide generated when an acid reacts with a carbonate and does not give the proper end point, unless the solution is boiled to expel the carbon dioxide. Litmus may also be used as the indicator, but here again it is necessary to boil as carbon dioxide also affects this substance. As an aid to the action of these common indicators the following table may be helpful: _Color in _Color in _Indicator._ Acid Alkaline _Action of Solution._ Solution._ CO_{2}._ Methyl orange Red Yellow Very slightly acid Phenolphthalein Colorless Red Acid Litmus Red Blue Acid It may be further stated that methyl orange at the neutral point is orange in color. To calculate the percentage of effective alkali from the above titrations, it must be first pointed out that in the case of caustic potash or soda aliquot portions are taken. This is done to reduce the error necessarily involved by weighing, as the absorption of water is decided. Thus we had, say, exactly 5 grams which weighed 5.05 grams by the time it was balanced. This was dissolved in 500 cubic centimeters of water and 50 cubic centimeters or one tenth of the amount of the solution was taken, or in each 50 cubic centimeters there were 0.505 grams of the sample. We thus reduced the error of weighing by one tenth provided other conditions introduce no error. In the case of the carbonates the weight is taken directly. One cubic centimeter of a normal acid solution is the equivalent of: Grams. Sodium Carbonate, Na_{2}CO_{3} 0.05305 Sodium Hydroxide, NaOH 0.04006 Sodium Oxide, Na_{2}O 0.02905 Carbonate K_{2}CO_{3} 0.06908 Potassium Hydroxide, KOH 0.05616 Potassium Oxide, K_{2}O 0.04715 Hence to arrive at the alkalinity we multiply the number of cubic centimeters, read on the burette, by the factor opposite the terms in which we desire to express the alkalinity, divide the weight in grams thus obtained by the original weight taken, and multiply the result by 100, which gives the percentage of alkali in the proper terms. For example, say, we took the 0.505 grams of caustic potash as explained above and required 8.7 cubic centimeter normal acid to neutralize the solution, then 8.7 � .05616 = .4886 grams KOH in sample .4886 ----- � 100 = 96.73% KOH in sample. .505 Caustic potash often contains some caustic soda, and while it is possible to express the results in terms of KOH, regardless of any trouble that may be caused by this mixture in soap making, an error is introduced in the results, not all the alkali being caustic potash. In such cases it is advisable to consult a book on analysis as the analysis is far more complicated than those given we will not consider it. The presence of carbonates, as already stated, also causes an error. To overcome this the alkali is titrated in absolute alcohol, filtering off the insoluble carbonate. The soluble portion is caustic hydrate and may be titrated as such. The carbonate remaining on the filter paper is dissolved in water and titrated as carbonate. SOAP ANALYSIS. To obtain a sample of a cake of soap for analysis is a rather difficult matter as the moisture content of the outer and inner layer varies considerably. To overcome this difficulty a borer or sampler may be run right through the cake of soap, or slices may be cut from various parts of the cake, or the cake may be cut and run through a meat chopper several times and mixed. A sufficient amount of a homogeneous sample obtained by any of these methods is preserved for the entire analysis by keeping the soap in a securely stoppered bottle. The more important determinations of soap are moisture, free alkali, or fatty acid, combined alkali and total fatty matter. Besides these it is often necessary to determine insoluble matter, glycerine, unsaponifiable matter, rosin and sugar. MOISTURE. The analysis of soap for moisture, at its best, is most unsatisfactory, for by heating it is impossible to drive off all the water, and on the other hand volatile oils driven off by heat are a part of the loss represented as moisture. The usual method of determining moisture is to weigh 2 to 3 grams of finely shaved soap on a watch glass and heat in an oven at 105 degrees C. for 2 to 3 hours. The loss in weight is represented as water, although it is really impossible to drive off all the water in this way. To overcome the difficulties just mentioned either the Smith or Fahrion method may be used. Allen recommends Smith's method which is said to be truthful to within 0.25 per cent. Fahrion's method, according to the author, gives reliable results to within 0.5 per cent. Both are more rapid than the above manipulation. To carry out the method of Smith, 5 to 10 grams of finely ground soap are heated over a sand bath with a small Bunsen flame beneath it, in a large porcelain crucible. The heating takes 20 to 30 minutes, or until no further evidence is present of water being driven off. This may be tested by the fogging of a cold piece of glass held over the crucible immediately upon removing the burner. When no fog appears the soap is considered dry. Any lumps of soap may be broken up by a small glass rod, weighed with the crucible, and with a roughened end to more easily separate the lumps. Should the soap burn, this can readily be detected by the odor, which, of course, renders the analysis useless. The loss in weight is moisture. By Fahrion's method[13], 2 to 4 grams of soap are weighed in a platinum crucible and about three times its weight of oleic acid, which has been heated at 120 degrees C. until all the water is driven off and preserved from moisture, is added and reweighed. The dish is then cautiously heated with a small flame until all the water is driven off and all the soap is dissolved. Care must be exercised not to heat too highly or the oleic acid will decompose. The moment the water is all driven off a clear solution is formed, provided no fillers are present in the soap. The dish is then cooled in a dessicator and reweighed. The loss in weight of acid plus soap is moisture and is calculated on the weight of soap taken. This determination takes about fifteen minutes. FREE ALKALI OR ACID. (_a_) _Alcoholic Method._ Test a freshly cut surface of the soap with a few drops of an alcoholic phenolphthalein solution. If it does not turn red it may be assumed free fat is present; should a red color appear, free alkali is present. In any case dissolve 2 to 5 grams of soap in 100 cubic centimeters of neutralized alcohol and heat to boiling until in solution. Filter off the undissolved portion containing carbonate, etc., and wash with alcohol. Add phenolphthalein to the filtrate and titrate with N/10 acid and calculate the per cent. of free alkali as sodium or potassium hydroxide. Should the filtrate be acid instead of alkaline, titrate with N/10 alkali and calculate the percentage of free fatty acid as oleic acid. The insoluble portion remaining on the filter paper is washed with water until all the carbonate is dissolved. The washings are then titrated with N/10 sulfuric acid and expressed as sodium or potassium carbonate. Should borates or silicates be present it is possible to express in terms of these. If borax is present the carbon dioxide is boiled off after neutralizing exactly to methyl orange; cool, add mannite and phenolphthalein and titrate the boric acid with standard alkali. (_b_) _Bosshard and Huggenberg Method._[14] In using the alcoholic method for the determination of the free alkali or fat in soap there is a possibility of both free fat and free alkali being present. Upon boiling in an alcoholic solution the fat will be saponified, thus introducing an error in the analysis. The method of Bosshard and Huggenberg overcomes this objection. Their method is briefly as follows: _Reagents._ 1. N/10 hydrochloric acid to standardize N/10 alcoholic sodium hydroxide. 2. Approximately N/10 alcoholic sodium hydroxide to fix and control the N/40 stearic acid. 3. N/40 stearic acid. Preparation: About 7.1 grams of stearic acid are dissolved in one liter of absolute alcohol, the solution filtered, the strength determined by titration against N/10 NaOH and then protected in a well stoppered bottle, or better still connected directly to the burette. 4. A 10 per cent. solution of barium chloride. Preparation: 100 grams of barium chloride are dissolved in one liter of distilled water and filtered. The neutrality of the solution should be proven as it must be neutral. 5. [Greek: alpha] naptholphthalein indicator according to Sorenson. Preparation: 0.1 gram of [Greek: alpha] naphtholphthalein is dissolved in 150 cubic centimeters of alcohol and 100 cubic centimeters of water. For every 10 cubic centimeters of liquid use at least 12 drops of indicator. 6. Phenolphthalein solution 1 gram to 100 cubic centimeter 96 per cent. alcohol. 7. Solvent, 50 per cent. alcohol neutralized. MANIPULATION. First--Determine the strength of the N/10 alcoholic sodium hydroxide in terms of N/10 hydrochloric acid and calculate the factor, e. g.: 10 c.c. N/10 alcoholic NaOH = 9.95 N/10 HCl} 10 c.c. N/10 alcoholic NaOH = 9.96 N/10 HCl} 9.96 The alcoholic N/10 NaOH has a factor of 0.996. Second--Control the N/40 stearic acid with the above alkali to obtain its factor, e. g.: 40 c.c. N/40 alcoholic stearic acid = 10.18 c.c. N/10 NaOH } 40 c.c. N/40 alcoholic stearic acid = } 10.2 10.22 c.c. N/10 NaOH } 10.2 � F N/10 NaOH (0.996) = Factor N/40 stearic acid Therefore Factor N/40 stearic acid = 1.016. Third--About 5 grams of soap are weighed and dissolved in 100 cubic centimeters of 50 per cent. neutralized alcohol in a 250 cubic centimeter Erlenmeyer flask over a water bath and connected with a reflux condensor. When completely dissolved, which takes but a few moments, it is cooled by allowing a stream of running water to run over the outside of the flask. Fourth--The soap is precipitated with 15 to 20 cubic centimeters of the 10 per cent. barium chloride solution. Fifth--After the addition of 2 to 5 cubic centimeters of [Greek: alpha] naphtholphthalein solution the solution is titrated with N/40 alcoholic stearic acid. [Greek: alpha] naphtholphthalein is red with an excess of stearic acid. To mark the color changes it is advisable to first run a few blanks until the eye has become accustomed to the change in the indicator in the same way. The change from green to red can then be carefully observed. Let us presume 5 grams of soap were taken for the analysis and 20 cubic centimeters of N/40 stearic acid were required for the titration then to calculate the amount of NaOH since the stearic factor is 1.016. 20 � 1.016 = 20.32 N/40 stearic acid really required. 1 cubic centimeter N/40 stearic acid = 0.02 per cent. NaOH for 5 grams soap. [Greek: Delta] 20.32 cubic centimeters N/40 stearic acid = 0.02 � 20.32 per cent. NaOH for 5 grams soap. Hence the soap contains 0.4064 per cent. NaOH. It is necessary, however, to make a correction by this method. When the free alkali amounts to over 0.1 per cent. the correction is + 0.01, and when the free alkali exceeds 0.4 per cent. the correction is + 0.04, hence in the above case we multiply 0.004064 by 0.04, add this amount to 0.004064 and multiply by 100 to obtain the true percentage. Should the alkalinity have been near 0.1 per cent. we would have multiplied by 0.01 and added this. If carbonate is also present in the soap, another 5 grams of soap is dissolved in 100 cubic centimeters of 50 per cent. alcohol and the solution titrated directly after cooling with N/40 stearic acid, using [Greek: alpha] naphtholphthalein or phenolphthalein as an indicator, without the addition of barium chloride. From the difference of the two titrations the alkali present as carbonate is determined. If the decomposed soap solution is colorless with phenolphthalein, free fatty acids are present, which may be quickly determined with alcoholic N/10 sodium hydroxide. INSOLUBLE MATTER. The insoluble matter in soap may consist of organic or inorganic substances. Among the organic substances which are usually present in soap are oat meal, bran, sawdust, etc., while among the common inorganic or mineral compounds are pumice, silex, clay, talc, zinc oxide, infusorial earth, sand or other material used as fillers. To determine insoluble matter, 5 grams of soap are dissolved in 75 cubic centimeters of hot water. The solution is filtered through a weighed gooch crucible or filter paper. The residue remaining on the filter is washed with hot water until all the soap is removed, is then dried to constant weight at 105 degrees C. and weighed. From the difference in weight of the gooch or filter paper and the dried residue remaining thereon after filtering and drying, the total percentage of insoluble matter may easily be calculated. By igniting the residue and reweighing the amount of insoluble mineral matter can be readily determined. STARCH AND GELATINE. Should starch or gelatine be present in soap it is necessary to extract 5 grams of the soap with 100 cubic centimeters of 95 per cent. neutralized alcohol in a Soxhlet extractor until the residue on the extraction thimble is in a powder form. If necessary the apparatus should be disconnected and any lumps crushed, as these may contain soap. The residue remaining on the thimble consists of all substances present in soap, insoluble in alcohol. This is dried and weighed so that any percentage of impurities not actually determined can be found by difference. Starch and gelatine are separated from carbonate, sulfate and borate by dissolving the latter out through a filter with cold water. The starch and gelatine thus remaining can be determined by known methods, starch by the method of direct hydrolysis[15] and gelatine by Kjeldahling and calculating the corresponding amount of gelatine from the percentage of nitrogen (17.9%) therein.[16] TOTAL FATTY AND RESIN ACIDS. To the filtrate from the insoluble matter add 40 cubic centimeters of half normal sulfuric acid, all the acid being added at once. Boil, stir thoroughly for some minutes and keep warm on a water bath until the fatty acids have collected as a clear layer on the surface. Cool by placing the beaker in ice and syphon off the acid water through a filter. Should the fatty acids not readily congeal a weighed amount of dried bleached bees-wax or stearic acid may be added to the hot mixture. This fuses with the hot mass and forms a firm cake of fatty acids upon cooling. Without removing the fatty acids from the beaker, add about 300 cubic centimeters of hot water, cool, syphon off the water through the same filter used before and wash again. Repeat washing, cooling and syphoning processes until the wash water is no longer acid. When this stage is reached, dissolve any fatty acid which may have remained on the filter with hot 95 per cent. alcohol into the beaker containing the fatty acids. Evaporate the alcohol and dry the beaker to constant weight over a water bath. The fatty acids thus obtained represent the combined fatty acids, uncombined fat and hydrocarbons. DETERMINATION OF ROSIN. If resin acids are present, this may be determined by the Liebermann-Storch reaction. To carry out this test shake 2 cubic centimeters of the fatty acids with 5 cubic centimeters of acetic anhydride; warm slightly; cool; draw off the anhydride and add 1:1 sulfuric acid. A violet color, which is not permanent, indicates the presence of rosin in the soap. The cholesterol in linseed or fish oil, which of course may be present in the soap, also give this reaction. Should resin acids be present, these may be separated by the Twitchell method, which depends upon the difference in the behavior of the fatty and resin acids when converted into their ethyl esters through the action of hydrochloric acid. This may be carried out as follows: Three grams of the dried mixed acids are dissolved in 25 cubic centimeters of absolute alcohol in a 100 cubic centimeter stoppered flask; the flask placed in cold water and shaken. To this cooled solution 25 cubic centimeters of absolute alcohol saturated with dry hydrochloric acid is added. The flask is shaken occasionally and the action allowed to continue for twenty minutes, then 10 grams of dry granular zinc chloride are added, the flask shaken and again allowed to stand for twenty minutes. The contents of the flask are then poured into 200 cubic centimeters of water in a 500 cubic centimeter beaker and the flask rinsed out with alcohol. A small strip of zinc is placed in the beaker and the alcohol evaporated. The beaker is then cooled and transferred to a separatory funnel, washing out the beaker with 50 cubic centimeters of gasoline (boiling below 80 degrees C.) and extracting by shaking the funnel well. Draw off the acid solution after allowing to separate and wash the gasoline with water until free from hydrochloric acid. Draw off the gasoline solution and evaporate the gasoline. Dissolve the residue in neutral alcohol and titrate with standard alkali using phenolphthalein as an indicator. One cubic centimeter of normal alkali equals 0.346 grams of rosin. The rosin may be gravimetrically determined by washing the gasoline extract with water, it not being necessary to wash absolutely free from acid, then adding 0.5 gram of potassium hydroxide and 5 cubic centimeters of alcohol in 50 cubic centimeters of water. Upon shaking the resin acids are rapidly saponified and extracted by the dilute alkaline solution as rosin soaps, while the ethyl esters remain in solution in the gasoline. Draw off the soap solution, wash the gasoline solution again with dilute alkali and unite the alkaline solutions. Decompose the alkaline soap solution with an excess of hydrochloric acid and weigh the resin acids liberated as in the determination of total fatty acids. According to Lewkowitsch, the results obtained by the volumetric method which assumes a combining weight of 346 for resin acids, are very likely to be high. On the other hand those obtained by the gravimetric method are too low. Leiste and Stiepel[17] have devised a simpler method for the determination of rosin. They make use of the fact that the resin acids as sodium soaps are soluble in acetone and particularly acetone containing two per cent. water, while the fatty acid soaps are soluble in this solvent to the extent of only about 2 per cent. First of all it is necessary to show that the sample to be analyzed contains a mixture of resin and fatty acids. This may be done by the Liebermann-Storch reaction already described. Glycerine interferes with the method. Two grams of fatty acids or 3 grams of soap are weighed in a nickel crucible and dissolved in 15-20 cubic centimeters of alcohol. The solution is then neutralized with alcoholic sodium hydroxide, using phenolphthalein as an indicator. The mass is concentrated by heat over an asbestos plate until a slight film forms over it. Then about 10 grams of sharp, granular, ignited sand are stirred in by means of a spatula, the alcohol further evaporated, the mixture being constantly stirred and then thoroughly dried in a drying oven. The solvent for the cooled mass is acetone containing 2 per cent. water. It is obtained from acetone dried by ignited sodium sulfate and adding 2 per cent. water by volume. One hundred cubic centimeters of this solvent are sufficient for extracting the above. The extraction of the rosin soap is conducted by adding 10 cubic centimeters of acetone eight times, rubbing the mass thoroughly with a spatula and decanting. The decanted portions are combined in a beaker and the suspended fatty soaps allowed to separate. The mixture is then filtered into a previously weighed flask and washed several times with the acetone remaining. The solution of rosin soap should show no separation of solid matter after having evaporated to half the volume and allowing to cool. If a separation should occur another filtration and the slightest possible washing is necessary. To complete the analysis, the acetone is completely evaporated and the mass dried to constant weight in a drying oven. The weight found gives the weight of the rosin soap. In conducting the determination, it is important to dry the mixture of soap and sand thoroughly. In dealing with potash soaps it is necessary to separate the fatty acids from these and use them as acetone dissolves too great a quantity of a potash soap. TOTAL ALKALI. In the filtrate remaining after having washed the fatty acids in the determination of total fatty and resin acids all the alkali present as soap, as carbonate and as hydroxide remains in solution as sulfate. Upon titrating this solution with half normal alkali the difference between the half normal acid used in decomposing the soap and alkali used in titrating the excess of acid gives the amount of total alkali in the soap. By deducting the amount of free alkali present as carbonate or hydroxide previously found the amount of combined alkali in the soap may be calculated. To quickly determine total alkali in soap a weighed portion of the soap may be ignited to a white ash and the ash titrated for alkalinity using methyl orange as an indicator. UNSAPONIFIED MATTER. Dissolve 5 grams of soap in 50 cubic centimeters of 50 per cent. alcohol. Should any free fatty acids be present neutralize them with standard alkali. Wash into a separatory funnel with 50 per cent. alcohol and extract with 100 cubic centimeters of gasoline, boiling at 50 degrees to 60 degrees C. Wash the gasoline with water, draw off the watery layer. Run the gasoline into a weighed dish, evaporate the alcohol, dry and weigh the residue as unsaponified matter. The residue contains any hydrocarbon oils or fats not converted into soap. SILICA AND SILICATES. The insoluble silicates, sand, etc., are present in the ignited residue in the determination of insoluble matter. Sodium silicate, extensively used as a filler, however, will only show itself in forming a pasty liquid. Where it is desired to determine sodium silicate, 10 grams of soap are ashed by ignition, hydrochloric acid added to the ash in excess and evaporated to dryness. More hydrochloric acid is then added and the mass is again evaporated until dry; then cooled; moistened with hydrochloric acid; dissolved in water; filtered; washed; the filtrate evaporated to dryness and again taken up with hydrochloric acid and water; filtered and washed. The precipitates are then combined and ignited. Silicon dioxide (SiO_{2}) is thus formed, which can be calculated to sodium silicate (Na_{2}Si_{4}O_{9}). Should other metals than alkali metals be suspected present the filtrate from the silica determinations should be examined. GLYCERINE IN SOAP. To determine the amount of glycerine contained in soap dissolve 25 grams in hot water, add a slight excess of sulfuric acid and keep hot until the fatty acids form as a clear layer on top. Cool the mass and remove the fatty acids. Filter the acid solution into a 25 cubic centimeter graduated flask; bring to the mark with water and determine the glycerine by the bichromate method as described under glycerine analysis. When sugar is present the bichromate would be reduced by the sugar, hence this method is not applicable. In this case remove the fatty acids as before, neutralize an aliquot portion with milk of lime, evaporate to 10 cubic centimeters, add 2 grams of sand and milk of lime containing about 2 grams of calcium hydroxide and evaporate almost to dryness. Treat the moist residue with 5 cubic centimeters of 96 per cent. alcohol, rub the whole mass into a paste, then constantly stirring, heat on a water bath and decant into a 250 cubic centimeter graduated flask. Repeat the washing with 5 cubic centimeters of alcohol five or six times, each time pouring the washings into the flask; cool the flask to room temperature and fill to the mark with 96 per cent. alcohol, agitate the flask until well mixed and filter through a dry filter paper. Take 200 cubic centimeters of the nitrate and evaporate to a syrupy consistency over a safety water bath. Wash the liquor into a stoppered flask with 20 cubic centimeters of absolute alcohol, add 30 cubic centimeters of absolute ether 10 cubic centimeters at a time, shaking well after each addition and let stand until clear. Pour off the solution through a filter into a weighed dish and wash out the flask with a mixture of three parts absolute ether and two parts absolute alcohol. Evaporate to a syrup, dry for one hour at the temperature of boiling water, weigh, ignite and weigh again. The loss is glycerine. This multiplied by 5/4 gives the total loss for the aliquot portion taken. The glycerine may also be determined by the acetin or bichromate methods after driving off the alcohol and ether if so desired. SUGAR IN SOAP. To determine sugar in soap, usually present in transparent soaps, decompose a soap solution of 5 grams of soap dissolved in 100 cubic centimeters of hot water with an excess of hydrochloric acid and separate the fatty acids as usual. Filter the acid solution into a graduated flask and make up to the mark. Take an aliquot containing approximately 1 per cent. of reducing sugar and determine the amount of sugar by the Soxhlet method.[18] GLYCERINE ANALYSIS. The methods of analyzing glycerine varied so greatly due to the fact that glycerine contained impurities which acted so much like glycerine as to introduce serious errors in the determinations of crude glycerine. This led to the appointment of committees in the United States and Europe to investigate the methods of glycerine analysis. An international committee met after their investigations and decided the acetin method should control the buying and selling of glycerine, but the more convenient bichromate method in a standardized form might be used in factory control and other technical purposes. The following are the methods of analysis and sampling as suggested by the international committee: SAMPLING. The most satisfactory method available for sampling crude glycerine liable to contain suspended matter, or which is liable to deposit salt on settling, is to have the glycerine sampled by a mutually approved sampler as soon as possible after it is filled into drums, but in any case before any separation of salt has taken place. In such cases he shall sample with a sectional sampler (see appendix) then seal the drums, brand them with a number for identification, and keep a record of the brand number. The presence of any visible salt or other suspended matter is to be noted by the sampler, and a report of the same made in his certificate, together with the temperature of the glycerine. Each drum must be sampled. Glycerine which has deposited salt or other solid matter cannot be accurately sampled from the drums, but an approximate sample can be obtained by means of the sectional sampler, which will allow a complete vertical section of the glycerine to be taken including any deposit. ANALYSIS. 1. _Determination of Free Caustic Alkali._--Put 20 grams of the sample into a 100 cc. flask, dilute with approximately 50 cc. of freshly boiled distilled water, add an excess of neutral barium chloride solution, 1 cc. of phenolphthalein solution, make up to the mark and mix. Allow the precipitate to settle, draw off 50 cc. of the clear liquid and titrate with normal acid (_N_/1). Calculate the percentage of Na_{2}O existing as caustic alkali. 2. _Determination of Ash and Total Alkalinity._--Weigh 2 to 5 grams of the sample in a platinum dish, burn off the glycerine over a luminous Argand burner or other source of heat,[19] giving a low temperature, to avoid volatilization and the formation of sulphides. When the mass is charred to the point that water will not be colored by soluble organic matter, lixiviate with hot distilled water, filter, wash and ignite the residue in the platinum dish. Return the filtrate and washings to the dish, evaporate the water, and carefully ignite without fusion. Weigh the ash. Dissolve the ash in distilled water and titrate total alkalinity, using as indicator methyl orange cold or litmus boiling. 3. _Determination of Alkali Present as Carbonate._--Take 10 grams of the sample, dilute with 50 cc. distilled water, add sufficient _N_/1 acid to neutralize the total alkali found at (2), boil under a reflux condenser for 15 to 20 minutes, wash down the condenser tube with distilled water, free from carbon dioxide, and then titrate back with _N_/1 NaOH, using phenolphthalein as indicator. Calculate the percentage of Na_{2}O. Deduct the Na_{2}O found in (1). The difference is the percentage of Na_{2}O existing as carbonate. 4. _Alkali Combined with Organic Acids._--The sum of the percentages of Na_{2}O found at (1) and (3) deducted from the percentage found at (2) is a measure of the Na_{2}O or other alkali combined with organic acids. 5. _Determination of Acidity._--Take 10 grams of the sample, dilute with 50 cc. distilled water free from carbon dioxide, and titrate with _N_/1 NaOH and phenolphthalein. Express in terms of Na_{2}O required to neutralize 100 grams. 6. _Determination of Total Residue at 160° C._--For this determination the crude glycerine should be slightly alkaline with Na_{2}CO_{3} not exceeding 0.2 per cent. Na_{2}O, in order to prevent loss of organic acids. To avoid the formation of polyglycerols this alkalinity must not be exceeded. Ten grams of the sample are put into a 100 cc. flask, diluted with water and the calculated quantity of _N_/1 HCl or Na_{2}CO_{3} added to give the required degree of alkalinity. The flask is filled to 100 cc., the contents mixed, and 10 cc. measured into a weighed Petrie or similar dish 2.5 in. in diameter and 0.5 in. deep, which should have a flat bottom. In the case of crude glycerine abnormally high in organic residue a smaller amount should be taken, so that the weight of the organic residue does not materially exceed 30 to 40 milligrams. The dish is placed on a water bath (the top of the 160° oven acts equally well) until most of the water has evaporated. From this point the evaporation is effected in the oven. Satisfactory results are obtained in an oven[20] measuring 12 ins. cube, having an iron plate 0.75 in. thick lying on the bottom to distribute the heat. Strips of asbestos millboard are placed on a shelf half way up the oven. On these strips the dish containing the glycerine is placed. If the temperature of the oven has been adjusted to 160° C. with the door closed, a temperature of 130° to 140° can be readily maintained with the door partially open, and the glycerine, or most of it, should be evaporated off at this temperature. When only a slight vapor is seen to come off, the dish is removed and allowed to cool. An addition of 0.5 to 1.0 cc. of water is made, and by a rotary motion the residue brought wholly or nearly into solution. The dish is then allowed to remain on a water bath or top of the oven until the excess water has evaporated and the residue is in such a condition that on returning to the oven at 160° C. it will not spurt. The time taken up to this point cannot be given definitely, nor is it important. Usually two or three hours are required. From this point, however, the schedule of time must be strictly adhered to. The dish is allowed to remain in the oven, the temperature of which is carefully maintained at 160° C. for one hour, when it is removed, cooled, the residue treated with water, and the water evaporated as before. The residue is then subjected to a second baking of one hour, after which the dish is allowed to cool in a desiccator over sulphuric acid and weighed. The treatment with water, etc., is repeated until a constant loss of 1 to 1.5 mg. per hour is obtained. In the case of acid glycerine a correction must be made for the alkali added 1 cc. _N_/1 alkali represents an addition of 0.03 gram. In the case of alkaline crudes a correction should be made for the acid added. Deduct the increase in weight due to the conversion of the NaOH and Na_{2}CO_{3} to NaCl. The corrected weight multiplied by 100 gives the percentage of _total residue at 160° C._ This residue is taken for the determination of the non-volatile acetylizable impurities (see acetin method). 7. _Organic residue._--Subtract the ash from the total residue at 160° C. Report as organic residue at 160° C. (it should be noted that alkaline salts of fatty acids are converted to carbonates on ignition and that the CO_{3} thus derived is not included in the organic residue). ACETIN PROCESS FOR THE DETERMINATION OF GLYCEROL. This process is the one agreed upon at a conference of delegates from the British, French, German and American committees, and has been confirmed by each of the above committees as giving results nearer to the truth than the bichromate method on crudes in general. It is the process to be used (if applicable) whenever only one method is employed. On pure glycerines the results are identical with those obtained by the bichromate process. For the application of this method the crude glycerine should not contain over 60 per cent. water. REAGENTS REQUIRED. (_A_) _Best Acetic Anhydride._--This should be carefully selected. A good sample must not require more than 0.1 cc. normal NaOH for saponification of the impurities when a blank is run on 7.5 cc. Only a slight color should develop during digestion of the blank. The anhydride may be tested for strength by the following method: Into a weighed stoppered vessel, containing 10 to 20 cc. of water, run about 2 cc. of the anhydride, replace the stopper and weigh. Let stand with occasional shaking, for several hours, to permit the hydrolysis of all the anhydride; then dilute to about 200 cc., add phenolphthalein and titrate with _N_/1 NaOH. This gives the total acidity due to free acetic acid and acid formed from the anhydride. It is worthy of note that in the presence of much free anhydride a compound is formed with phenolphthalein, soluble in alkali and acetic acid, but insoluble in neutral solutions. If a turbidity is noticed toward the end of the neutralization it is an indication that the anhydride is incompletely hydrolyzed and inasmuch as the indicator is withdrawn from the solution, results may be incorrect. Into a stoppered weighing bottle containing a known weight of recently distilled aniline (from 10 to 20 cc.) measure about 2 cc. of the sample, stopper, mix, cool and weigh. Wash the contents into about 200 cc. of cold water, and titrate the acidity as before. This yields the acidity due to the original, preformed, acetic acid plus one-half the acid due to anhydride (the other half having formed acetanilide); subtract the second result from the first (both calculated to 100 grams) and double the result, obtaining the cc. _N_/1 NaOH per 100 grams of the sample. 1 cc. _N_/NaOH equals 0.0510 anhydride. (_B_) _Pure Fused Sodium Acetate._--The purchased salt is again completely fused in a platinum, silica or nickel dish, avoiding charring, powdered quickly and kept in a stoppered bottle or desiccator. It is most important that the sodium acetate be anhydrous. (_C_) _A Solution of Caustic Soda for Neutralizing, of about N_/1 _Strength, Free from Carbonate._--This can be readily made by dissolving pure sodium hydroxide in its own weight of water (preferably water free from carbon dioxide) and allowing to settle until clear, or filtering through an asbestos or paper filter. The clear solution is diluted with water free from carbon dioxide to the strength required. (_D_) _N_/1 _Caustic Soda Free from Carbonate._--Prepared as above and carefully standardized. Some caustic soda solutions show a marked diminution in strength after being boiled; such solutions should be rejected. (_E_) _N_/1 _Acid._--Carefully standardized. (_F_) _Phenolphthalein Solution._--0.5 per cent. phenolphthalein in alcohol and neutralized. THE METHOD. In a narrow-mouthed flask (preferably round-bottomed), capacity about 120 cc., which has been thoroughly cleaned and dried, weigh accurately and as rapidly as possible 1.25 to 1.5 grams of the glycerine. A Grethan or Lunge pipette will be found convenient. Add about 3 grams of the anhydrous sodium acetate, then 7.5 cc. of the acetic anhydride, and connect the flask with an upright Liebig condenser. For convenience the inner tube of this condenser should not be over 50 cm. long and 9 to 10 mm. inside diameter. The flask is connected to the condenser by either a ground glass joint (preferably) or a rubber stopper. If a rubber stopper is used it should have had a preliminary treatment with hot acetic anhydride vapor. Heat the contents and keep just boiling for one hour, taking precautions to prevent the salts drying on the sides of the flask. Allow the flask to cool somewhat, and through the condenser tube add 50 cc. of distilled water free from carbon dioxide at a temperature of about 80° C., taking care that the flask is not loosened from the condenser. The object of cooling is to avoid any sudden rush of vapors from the flask on adding water, and to avoid breaking the flask. Time is saved by adding the water before the contents of the flask solidify, but the contents may be allowed to solidify and the test proceeded with the next day without detriment, bearing in mind that the anhydride in excess is much more effectively hydrolyzed in hot than in cold water. The contents of the flask may be warmed to, but must not exceed, 80° C., until the solution is complete, except a few dark flocks representing organic impurities in the crude. By giving the flask a rotary motion, solution is more quickly effected. Cool the flask and contents without loosening from the condenser. When quite cold wash down the inside of the condenser tube, detach the flask, wash off the stopper or ground glass connection into the flask, and filter the contents through an acid-washed filter into a Jena glass flask of about 1 litre capacity. Wash thoroughly with cold distilled water free from carbon dioxide. Add 2 cc. of phenolphthalein solution (_F_), then run in caustic soda solution (_C_) or (_D_) until a faint pinkish yellow color appears throughout the solution. This neutralization must be done most carefully; the alkali should be run down the sides of the flask, the contents of which are kept rapidly swirling with occasional agitation or change of motion until the solution is nearly neutralized, as indicated by the slower disappearance of the color developed locally by the alkali running into the mixture. When this point is reached the sides of the flask are washed down with carbon dioxide-free water and the alkali subsequently added drop by drop, mixing after each drop until the desired tint is obtained. Now run in from a burette 50 cc. or a calculated excess of _N_/1 NaOH (_D_) and note carefully the exact amount. Boil gently for 15 minutes, the flask being fitted with a glass tube acting as a partial condenser. Cool as quickly as possible and titrate the excess of NaOH with _N_/1 acid (_E_) until the pinkish yellow or chosen end-point color just remains.[21] A further addition of the indicator at this point will cause an increase of the pink color; this must be neglected, and the first end-point taken. From the _N_/1 NaOH consumed calculate the percentage of glycerol (including acetylizable impurities) after making the correction for the blank test described below. 1 cc. _N_/1 NaOH = 0.03069 gram glycerol. The coefficient of expansion for normal solutions is 0.00033 per cc. for each degree centigrade. A correction should be made on this account if necessary. _Blank Test._--As the acetic anhydride and sodium acetate may contain impurities which affect the result, it is necessary to make a blank test, using the same quantities of acetic anhydride, sodium acetate and water as in the analysis. It is not necessary to filter the solution of the melt in this case, but sufficient time must be allowed for the hydrolysis of the anhydride before proceeding with the neutralization. After neutralization it is not necessary to add more than 10 cc. of the _N_/1 alkali (_D_), as this represents the excess usually present after the saponification of the average soap lye crude. In determining the acid equivalent of the _N_/1 NaOH, however, the entire amount taken in the analysis, 50 cc., should be titrated after dilution with 300 cc. water free from carbon dioxide and without boiling. _Determination of the Glycerol Value of the Acetylizable Impurities._--The total residue at 160° C. is dissolved in 1 or 2 cc. of water, washed into the acetylizing flask and evaporated to dryness. Then add anhydrous sodium acetate and acetic anhydride in the usual amounts and proceed as described in the regular analysis. After correcting for the blank, calculate the result to glycerol. WAYS OF CALCULATING ACTUAL GLYCEROL CONTENT. (1) Determine the apparent percentage of glycerol in the sample by the acetin process as described. The result will include acetylizable impurities if any are present. (2) Determine the total residue at 160° C. (3) Determine the acetin value of the residue at (2) in terms of glycerol. (4) Deduct the result found at (3) from the percentage obtained at (1) and report this corrected figure as glycerol. If volatile acetylizable impurities are present these are included in this figure. Trimethyleneglycol is more volatile than glycerine and can therefore be concentrated by fractional distillation. An approximation to the quantity can be obtained from the spread between the acetin and bichromate results on such distillates. The spread multiplied by 1.736 will give the glycol. BICHROMATE PROCESS FOR GLYCEROL DETERMINATION. REAGENTS REQUIRED. (_A_) _Pure potassium bichromate_ powdered and dried in air free from dust or organic vapors, at 110° to 120° C. This is taken as the standard. (_B_) _Dilute Bichromate Solution._--7.4564 grams of the above bichromate are dissolved in distilled water and the solution made up to one liter at 15.5° C. (_C_) _Ferrous Ammonium Sulphate._--It is never safe to assume this salt to be constant in composition and it must be standardized against the bichromate as follows: dissolve 3.7282 grams of bichromate (_A_) in 50 cc. of water. Add 50 cc. of 50 per cent. sulphuric acid (by volume), and to the cold undiluted solution add from a weighing bottle a moderate excess of the ferrous ammonium sulphate, and titrate back with the dilute bichromate (_B_). Calculate the value of the ferrous salt in terms of bichromate. (_D_) _Silver Carbonate._--This is prepared as required for each test from 140 cc. of 0.5 per cent. silver sulphate solution by precipitation, with about 4.9 cc. _N_/1 sodium carbonate solution (a little less than the calculated quantity of _N_/1 sodium carbonate should be used as an excess to prevent rapid settling). Settle, decant and wash one by decantation. (_E_) _Subacetate of Lead._--Boil a 10 per cent. solution of pure lead acetate with an excess of litharge for one hour, keeping the volume constant, and filter while hot. Disregard any precipitate which subsequently forms. Preserve out of contact with carbon dioxide. (_F_) _Potassium Ferricyanide._--A very dilute, freshly prepared solution containing about 0.1 per cent. THE METHOD. Weigh 20 grams of the glycerine, dilute to 250 cc. and take 25 cc. Add the silver carbonate, allow to stand, with occasional agitation, for about 10 minutes, and add a slight excess (about 5 cc. in most cases) of the basic lead acetate (_E_), allow to stand a few minutes, dilute with distilled water to 100 cc., and then add 0.15 cc. to compensate for the volume of the precipitate, mix thoroughly, filter through an air-dry filter into a suitable narrow-mouthed vessel, rejecting the first 10 cc., and return the filtrate if not clear and bright. Test a portion of the filtrate with a little basic lead acetate, which should produce no further precipitate (in the great majority of cases 5 cc. are ample, but occasionally a crude will be found requiring more, and in this case another aliquot of 25 cc. of the dilute glycerine should be taken and purified with 6 cc. of the basic acetate). Care must be taken to avoid a marked excess of basic acetate. Measure off 25 cc. of the clear filtrate into a flask or beaker (previously cleaned with potassium bichromate and sulphuric acid). Add 12 drops of sulphuric acid (1: 4) to precipitate the small excess of lead as sulphate. Add 3.7282 grams of the powdered potassium bichromate (_A_). Rinse down the bichromate with 25 cc. of water and let stand with occasional shaking until all the bichromate is dissolved (no reduction will take place in the cold). Now add 50 cc. of 50 per cent. sulphuric acid (by volume) and immerse the vessel in boiling water for two hours and keep protected from dust and organic vapors, such as alcohol, till the titration is completed. Add from a weighing bottle a slight excess of the ferrous ammonium sulphate (_C_), making spot tests on a porcelain plate with the potassium ferricyanide (_F_). Titrate back with the dilute bichromate. From the amount of bichromate reduced calculate the percentage of glycerol. 1 gram glycerol = 7.4564 grams bichromate. 1 gram bichromate = 0.13411 gram glycerol. The percentage of glycerol obtained above includes any oxidizable impurities present after the purification. A correction for the non-volatile impurities may be made by running a bichromate test on the residue at 160° C. NOTES. (1) It is important that the concentration of acid in the oxidation mixture and the time of oxidation should be strictly adhered to. (2) Before the bichromate is added to the glycerine solution it is essential that the slight excess of lead be precipitated with sulphuric acid, as stipulated. (3) For crudes practically free from chlorides the quantity of silver carbonate may be reduced to one-fifth and the basic lead acetate to 0.5 cc. (4) It is sometimes advisable to add a little potassium sulphate to insure a clear filtrate. SAMPLING CRUDE GLYCERINE. The usual method of sampling crude glycerine hitherto has been by means of a glass tube, which is slowly lowered into the drum with the object of taking as nearly as possible a vertical section of the glycerine contained in the drum. This method has been found unsatisfactory, owing to the fact that in cold climates glycerine runs into the tube very slowly, so that, owing to the time occupied, it is impossible to take a complete section of the crude. Another objection to the glass tube is that it fails to take anything approaching a correct proportion of any settled salt contained in the drum. The sampler which is illustrated herewith has been devised with the object of overcoming the objections to the glass tube as far as possible. It consists of two brass tubes, one fitting closely inside the other. A number of ports are cut out in each tube in such a way that when the ports are opened a continuous slot is formed which enables a complete section to be taken throughout the entire length of the drum. By this arrangement the glycerine fills into the sampler almost instantaneously. There are a number of ports cut at the bottom of the sampler which render it possible to take a proportion of the salt at the bottom of the drum. The instrument is so constructed that all the ports, including the bottom ones, can be closed simultaneously by the simple action of turning the handle at the top; a pointer is arranged which indicates on a dial when the sampler is open or closed. In samplers of larger section (1 in.) it is possible to arrange a third motion whereby the bottom ports only are open for emptying, but in samplers of smaller dimensions (5/8 in.) this third motion must be dispensed with, otherwise the dimensions of the ports have to be so small that the sampler would not be efficient. In using the sampler it is introduced into the drum with the ports closed, and when it has touched the bottom, the ports are opened for a second or two, then closed and withdrawn, and the sample discharged into the receiving vessel by opening the ports. When the drum contains salt which has deposited, the ports must be opened before the sampler is pushed through the salt, thus enabling a portion to be included in the sample. It is, however, almost impossible to obtain a correct proportion of salt after it has settled in the drum and it is therefore recommended that the drum be sampled before any salt has deposited. A sampler 1 in. in diameter withdraws approximately 10 oz. from a 110-gal. drum. A sampler 5/8 in. in diameter will withdraw about 5 oz. FOOTNOTES: [13] Zeit. Angew. Chem. 19, 385 (1906). [14] Zeit. Angew. Chem. 27, 11-20 (1914). [15] Bull. 107, Bur. Chem. U. S. Dept. Agriculture. [16] Richards and Gies, Am. J. Physiol. (1902) 7, 129. [17] Seifensieder Ztg. (1913) No. 46. [18] Bull 107, Bur. Chem. U. S. Dept. Agriculture. [19] Carbon is readily burned off completely, without loss of chlorides, in a gas-heated muffle furnace adjusted to a dull red heat. [20] An electric oven suitable for this work, which is readily adjusted to 160 degs. C., has been made for Mr. Low and the chairman, by the Apparatus and Specialty Company, Lansing, Mich. Its size is 9-1/2 � 10 � 16 inches, and capacity 8 Petrie dishes. It gives a strong draft at constant temperature. [21] A precipitate at this point is an indication of the presence of iron or alumina, and high results will be obtained unless a correction is made as described below. CHAPTER VII Standard Methods for the Sampling and Analysis of Commercial Fats and Oils[22] The following report of the _Committee on Analysis of Commercial Fats and Oils_ of the _Division of Industrial Chemists and Chemical Engineers_ of the American Chemical Society was adopted April 14, 1919, by unanimous vote: W. D. RICHARDSON, _Chairman_, Swift and Co., Chicago, Ill. R. W. BAILEY, Stillwell and Gladding, New York City. W. J. GASCOYNE, W. J. Gascoyne and Co., Baltimore, Md. I. KATZ,[A] Wilson and Co., Chicago, Ill. A. LOWENSTEIN,[A] Morris and Co., Chicago, Ill. H. J. MORRISON, Proctor and Gamble Co., Ivorydale, Ohio. J. R. POWELL, Armour Soap Works, Chicago, Ill. R. J. QUINN,[A] Midland Chemical Co., Argo, Ill. PAUL RUDNICK, Armour and Co., Chicago, Ill. L. M. TOLMAN, Wilson and Co., Chicago, Ill. E. TWITCHELL,[A] Emery Candle Co., Cincinnati, Ohio. J. J. VOLLERTSEN, Morris and Co., Chicago, Ill. [Note A: Resigned.] Scope, Applicability and Limitations of the Methods. SCOPE. These methods are intended to aid in determining the commercial valuation of fats and fatty oils in their purchase and sale, based on the fundamental assumption commonly recognized in the trade, namely, that the product is true to name and is not adulterated. For methods for determining the identity of oils and fats, the absence of adulterants therein and for specific tests used in particular industries, the chemist is referred to standard works on the analysis of fats and oils. APPLICABILITY. The methods are applicable in commercial transactions involving fats and fatty oils used in the soap, candle and tanning industries, to edible fats and oils and to fats and fatty oils intended for lubricating and burning purposes. The methods are applicable to the raw oils used in the varnish and paint industry with the exceptions noted under limitations, but special methods have not been included. LIMITATIONS. The methods have not been developed with special reference to waxes (beeswax, carnauba wax, wool wax, etc.) although some of them may be found applicable to these substances. The Committee considers the Wijs method superior to the Hanus method for the determination of iodine number of linseed oil as well as other oils, although the Hanus method has been considered standard for this work for some time and has been adopted by the American Society for Testing Materials and in various specifications. It has been customary to use the Hübl method for the determination of iodine value of tung oil (China wood oil) but the Committee's work indicates that the Wijs method is satisfactory for this determination. Sampling. TANK CARS. 1. SAMPLING WHILE LOADING--Sample shall be taken at discharge of pipe where it enters tank car dome. The total sample taken shall be not less than 50 lbs. and shall be a composite of small samples of about 1 pound each, taken at regular intervals during the entire period of loading. The sample thus obtained is thoroughly mixed and uniform 3-lb. portions placed in air-tight 3-lb. metal containers. At least three such samples shall be put up, one for the buyer, one for the seller, and the third to be sent to a referee chemist in case of dispute. All samples are to be promptly and correctly labeled and sealed. 2. SAMPLING FROM CAR ON TRACK[23]--(_a_) _When contents are solid._[24] In this case the sample is taken by means of a large tryer measuring about 2 in. across and about 1-1/2 times the depth of the car in length. Several tryerfuls are taken vertically and obliquely toward the ends of the car until 50 lbs. are accumulated, when the sample is softened, mixed and handled as under (1). In case the contents of the tank car have assumed a very hard condition, as in Winter weather, so that it is impossible to insert the tryer, and it becomes necessary to soften the contents of the car by means of the closed steam coil (in nearly all tank cars the closed steam coil leaks) or by means of open steam in order to draw a proper sample, suitable arrangements must be made between buyer and seller for the sampling of the car after it is sufficiently softened, due consideration being given to the possible presence of water in the material in the car as received and also to the possible addition of water during the steaming. The Committee knows of no direct method for sampling a hard-frozen tank car of tallow in a satisfactory manner. (_b_) _When contents are liquid._ The sample taken is to be a 50-lb. composite made up of numerous small samples taken from the top, bottom and intermediate points by means of a bottle or metal container with removable stopper or top. This device attached to a suitable pole is lowered to the various desired depths, when the stopper or top is removed and the container allowed to fill. The 50-lb. sample thus obtained is handled as under (1). In place of the device described above, any sampler capable of taking a sample from the top, bottom, and center, or from a section through car, may be used. (_c_) _When contents are in semi-solid condition, or when stearine has separated from liquid portions._ In this case, a combination of (_a_) and (_b_) may be used or by agreement of the parties the whole may be melted and procedure (_b_) followed. BARRELS, TIERCES, CASKS, DRUMS, AND OTHER PACKAGES. All packages shall be sampled, unless by special agreement the parties arrange to sample a lesser number; but in any case not less than 10 per cent of the total number shall be sampled. The total sample taken shall be at least 20 lbs. in weight for each 100 barrels, or equivalent. 1. BARRELS, TIERCES AND CASKS--(_a_) _When contents are solid._ The small samples shall be taken by a tryer through the bunghole or through a special hole bored in the head or side for the purpose, with a 1-in. or larger auger. Care should be taken to avoid and eliminate all borings and chips from the sample. The tryer is inserted in such a way as to reach the head of the barrel, tierce, or cask. The large sample is softened, mixed and handled according to TANK CARS (1). (_b_) _When contents are liquid._ In this case use is made of a glass tube with constricted lower end. This is inserted slowly and allowed to fill with the liquid, when the upper end is closed and the tube withdrawn, the contents being allowed to drain into the sample container. After the entire sample is taken it is thoroughly mixed and handled according to TANK CARS (1). (_c_) _When contents are semi-solid._ In this case the tryer or a glass tube with larger outlet is used, depending on the degree of fluidity. (_d_) _Very hard materials, such as natural and artificial stearines._ By preference the barrels are stripped and samples obtained by breaking up contents of at least 10 per cent of the packages. This procedure is to be followed also in the case of cakes shipped in sacks. When shipped in the form of small pieces in sacks they can be sampled by grab sampling and quartering. In all cases the final procedure is as outlined under TANK CARS (1). 2. DRUMS--Samples are to be taken as under (1), use being made of the bunghole. The tryer or tube should be sufficiently long to reach to the ends of the drum. 3. OTHER PACKAGES--Tubs, pails and other small packages not mentioned above are to be sampled by tryer or tube (depending on fluidity) as outlined above, the tryer or tube being inserted diagonally whenever possible. 4. MIXED LOTS AND PACKAGES--When lots of tallow or other fats are received in packages of various shapes and sizes, and especially wherein the fat itself is of variable composition, such must be left to the judgment of the sampler. If variable, the contents of each package should be mixed as thoroughly as possible and the amount of the individual samples taken made proportional to the sizes of the packages. Analysis. SAMPLE. The sample must be representative and at least three pounds in weight and taken in accordance with the STANDARD METHODS FOR THE SAMPLING OF COMMERCIAL FATS AND OILS. It must be kept in an air-tight container, in a dark, cool place. Soften the sample if necessary by means of a gentle heat, taking care not to melt it. When sufficiently softened, mix the sample thoroughly by means of a mechanical egg beater or other equally effective mechanical mixer. MOISTURE AND VOLATILE MATTER. APPARATUS: _Vacuum Oven_--The Committee Standard Oven. DESCRIPTION--The Standard F. A. C. Vacuum Oven has been designed with the idea of affording a simple and compact vacuum oven which will give as uniform temperatures as possible on the shelf. As the figure shows, it consists of an iron casting of rectangular sections with hinged front door made tight by means of a gasket and which can be lowered on opening the oven so as to form a shelf on which samples may be rested. The oven contains but one shelf which is heated from above as well as below by means of resistance coils. Several thermometer holes are provided in order to ascertain definitely the temperature at different points on the shelf. In a vacuum oven where the heating is done almost entirely by radiation it is difficult to maintain uniform temperatures at all points, but the F. A. C. oven accomplishes this rather better than most vacuum ovens. Larger ovens containing more than one shelf have been tried by the Committee, but have been found to be lacking in temperature uniformity and means of control. The entire oven is supported by means of a 4-in. standard pipe which screws into the base of the oven and which in turn is supported by being screwed into a blind flange of suitable diameter which rests on the floor or work table. _Moisture Dish_--A shallow, glass dish, lipped, beaker form, approximately 6 to 7 cm. diameter and 4 cm. deep, shall be standard. DETERMINATION--Weigh out 5 grams (= 0.2 g. of the prepared sample) into a moisture dish. Dry to constant weight in _vacuo_ at a uniform temperature, not less than 15° C. nor more than 20° C. above the boiling point of water at the working pressure, which must not exceed 100 mm. of mercury.[25] Constant weight is attained when successive dryings for 1-hr. periods show an additional loss of not more that 0.05 per cent. Report loss in weight as MOISTURE AND VOLATILE MATTER.[26] [Illustration: STANDARD VACUUM OVEN] The vacuum-oven method cannot be considered accurate in the case of fats of the coconut oil group containing free acid and the Committee recommends that it be used only for oils of this group when they contain less than 1 per cent free acid. In the case of oils of this group containing more than 1 per cent free acid, recourse should be had temporarily to the routine control method for moisture and volatile matter[27] until the Committee develops a more satisfactory method. The air-oven method cannot be considered even approximately accurate in the case of the drying and semi-drying oils and those of the coconut oil group. Therefore, in the case of such oils as cottonseed oil, maize oil (corn oil), soy bean oil, linseed oil, coconut oil, palm kernel oil, etc., the vacuum-oven method should always be used, except in the case of fats of the coconut group containing more than 1 per cent free acid, as noted above. INSOLUBLE IMPURITIES. Dissolve the residue from the moisture and volatile matter determination by heating it on a steam bath with 50 cc. of kerosene. Filter the solution through a Gooch crucible properly prepared with asbestos,[28] wash the insoluble matter five times with 10-cc. portions of hot kerosene, and finally wash the residual kerosene out thoroughly with petroleum ether. Dry the crucible and contents to constant weight, as in the determination of moisture and volatile matter and report results as INSOLUBLE IMPURITIES. SOLUBLE MINERAL MATTER. Place the combined kerosene filtrate and kerosene washings from the insoluble impurities determination in a platinum dish. Place in this an ashless filter paper folded in the form of a cone, apex up. Light the apex of the cone, whereupon the bulk of the kerosene burns quietly. Ash the residue in a muffle, to constant weight, taking care that the decomposition of alkaline earth carbonates is complete, and report the result as SOLUBLE MINERAL MATTER.[29] When the percentage of soluble mineral matter amounts to more than 0.1 per cent, multiply the percentage by 10 and add this amount to the percentage of free fatty acids as determined.[30] FREE FATTY ACIDS. The ALCOHOL[31] used shall be approximately 95 per cent ethyl alcohol, freshly distilled from sodium hydroxide, which with phenolphthalein gives a definite and distinct end-point. DETERMINATION--Weigh 1 to 15 g. of the prepared sample into an Erlenmeyer flask, using the smaller quantity in the case of dark-colored, high acid fats. Add 50 to 100 cc. hot, neutral alcohol, and titrate with _N_/2, _N_/4 or _N_/10 sodium hydroxide depending on the fatty acid content, using phenolphthalein as indicator. Calculate to oleic acid, except that in the case of palm oil the results may also be expressed in terms of palmitic acid, clearly indicating the two methods of calculation in the report. In the case of coconut and palm kernel oils, calculate to and report in terms of lauric acid in addition to oleic acid, clearly indicating the two methods of calculation in the report. In the case of fats or greases containing more than 0.1 per cent of soluble mineral matter, add to the percentages of free fatty acids as determined 10 times the percentage of bases in the soluble mineral matter as determined.[30] This addition gives the equivalent of fatty acids combined with the soluble mineral matter. TITER. STANDARD THERMOMETER--The thermometer is graduated at zero and in tenth degrees from 10° C. to 65° C., with one auxiliary reservoir at the upper end and another between the zero mark and the 10° mark. The cavity in the capillary tube between the zero mark and the 10° mark is at least 1 cm. below the 10° mark, the 10° mark is about 3 or 4 cm. above the bulb, the length of the thermometer being about 37 cm. over all. The thermometer has been annealed for 75 hrs. at 450° C. and the bulb is of Jena normal 16''' glass, or its equivalent, moderately thin, so that the thermometer will be quick-acting. The bulb is about 3 cm. long and 6 mm. in diameter. The stem of the thermometer is 6 mm. in diameter and made of the best thermometer tubing, with scale etched on the stem, the graduation is clear-cut and distinct, but quite fine. The thermometer must be certified by the U. S. Bureau of Standards. GLYCEROL CAUSTIC SOLUTION--Dissolve 250 g. potassium hydroxide in 1900 cc. dynamite glycerin with the aid of heat. DETERMINATION--Heat 75 cc. of the glycerol-caustic solution to 150° C. and add 50 g. of the melted fat. Stir the mixture well and continue heating until the melt is homogeneous, at no time allowing the temperature to exceed 150° C. Allow to cool somewhat and carefully add 50 cc. 30 per cent sulfuric acid. Now add hot water and heat until the fatty acids separate out perfectly clear. Draw off the acid water and wash the fatty acids with hot water until free from mineral acid, then filter and heat to 130° C. as rapidly as possible while stirring. Transfer the fatty acids, when cooled somewhat, to a 1-in. by 4-in. titer tube, placed in a 16-oz. salt-mouth bottle of clear glass, fitted with a cork that is perforated so as to hold the tube rigidly when in position. Suspend the titer thermometer so that it can be used as a stirrer and stir the fatty acids slowly (about 100 revolutions per minute) until the mercury remains stationary for 30 seconds. Allow the thermometer to hang quietly with the bulb in the center of the tube and report the highest point to which the mercury rises as the titer of the fatty acids. The titer should be made at about 20° C. for all fats having a titer above 30° C. and at 10° C. below the titer for all other fats. Any convenient means may be used for obtaining a temperature of 10° below the titer of the various fats. The committee recommends first of all a chill room for this purpose; second, an artificially chilled small chamber with glass window; third, immersion of the salt-mouth bottle in water or other liquid of the desired temperature. UNSAPONIFIABLE MATTER. EXTRACTION CYLINDER--The cylinder shall be glass-stoppered, graduated at 40 cc., 80 cc. and 130 cc., and of the following dimensions: diameter about 1-3/8 in., height about 12 in. PETROLEUM ETHER--Redistilled petroleum ether, boiling under 75° C., shall be used. A blank must be made by evaporating 250 cc. with about 0.25 g. of stearine or other hard fat (previously brought to constant weight by heating) and drying as in the actual determination. The blank must not exceed a few milligrams. DETERMINATION--Weigh 5 g. (±0.20 g.) of the prepared sample into a 200-cc. Erlenmeyer flask, add 30 cc. of redistilled 95 per cent (approximately) ethyl alcohol and 5 cc. of 50 per cent aqueous potassium hydroxide, and boil the mixture for one hour under a reflux condenser. Transfer to the extraction cylinder and wash to the 40-cc. mark with redistilled 95 per cent ethyl alcohol. Complete the transfer, first with warm, then with cold water, till the total volume amounts to 80 cc. Cool the cylinder and contents to room temperature and add 50 cc. of petroleum ether. Shake _vigorously_ for one minute and allow to settle until both layers are clear, when the volume of the upper layer should be about 40 cc. Draw off the petroleum ether layer as closely as possible by means of a slender glass siphon into a separatory funnel of 500 cc. capacity. Repeat extraction at least four more times, using 50 cc. of petroleum ether each time. More extractions than five are necessary where the unsaponifiable matter runs high, say over 5 per cent, and also in some cases where it is lower than 5 per cent, but is extracted with difficulty. Wash the combined extracts in a separatory funnel three times with 25-cc. portions of 10 per cent alcohol, shaking vigorously each time. Transfer the petroleum ether extract to a wide-mouth tared flask or beaker, and evaporate the petroleum ether on a steam bath in an air current. Dry as in the method for MOISTURE AND VOLATILE MATTER. Any blank must be deducted from the weight before calculating unsaponifiable matter. Test the final residue for solubility in 50 cc. petroleum ether at room temperature. Filter and wash free from the insoluble residue, if any, evaporate and dry in the same manner as before. The Committee wishes to emphasize the necessity of thorough and vigorous shaking in order to secure accurate results. The two phases must be brought into the most intimate contact possible, otherwise low and disagreeing results may be obtained. IODINE NUMBER--WIJS METHOD. PREPARATION OF REAGENTS--_Wijs Iodine Solution_--Dissolve 13.0 g. of resublimed iodine in one liter of C. P. glacial acetic acid and pass in washed and dried chlorine gas until the original thiosulfate titration of the solution is not quite doubled. The solution is then preserved in amber glass-stoppered bottles, sealed with paraffin until ready for use. Mark the date on which the solution is prepared on the bottle or bottles and do not use Wijs solution which is more than 30 days old. There should be no more than a slight excess of iodine, and no excess of chlorine. When the solution is made from iodine and chlorine, this point can be ascertained by not quite doubling the titration.[32] The glacial acetic acid used for preparation of the Wijs solution should be of 99.0 to 99.5 per cent strength. In case of glacial acetic acids of somewhat lower strength, the Committee recommends freezing and centrifuging or draining as a means of purification. _N_/10 _Sodium Thiosulfate Solution_--Dissolve 24.8 g. of C. P. sodium thiosulfate in recently boiled distilled water and dilute with the same to one liter at the temperature at which the titrations are to be made. _Starch Paste_--Boil 1 g. of starch in 200 cc. of distilled water for 10 min. and cool to room temperature. An improved starch solution may be prepared by autoclaving 2 g. of starch and 6 g. of boric acid dissolved in 200 cc. water at 15 lbs. pressure for 15 min. This solution has good keeping qualities. _Potassium Iodide Solution_--Dissolve 150 g. of potassium iodide in water and make up to one liter. _N_/10 _Potassium Bichromate_--Dissolve 4.903 g. of C. P. potassium bichromate in water and make the volume up to one liter at the temperature at which titrations are to be made. The Committee calls attention to the fact that occasionally potassium bichromate is found containing sodium bichromate, although this is of rare occurrence. If the analyst suspects that he is dealing with an impure potassium bichromate, the purity can be ascertained by titration against re-sublimed iodine. However, this is unnecessary in the great majority of cases. _Standardization of the Sodium Thiosulfate Solution_--Place 40 cc. of the potassium bichromate solution, to which has been added 10 cc. of the solution of potassium iodide, in a glass-stoppered flask. Add to this 5 cc. of strong hydro-chloric acid. Dilute with 100 cc. of water, and allow the _N_/10 sodium thiosulfate to flow slowly into the flask until the yellow color of the liquid has almost disappeared. Add a few drops of the starch paste, and with constant shaking continue to add the _N_/10 sodium thiosulfate solution until the blue color just disappears. DETERMINATION--Weigh accurately from 0.10 to 0.50 g. (depending on the iodine number) of the melted and filtered sample into a clean, dry, 16-oz. glass-stoppered bottle containing 15-20 cc. of carbon tetrachloride or chloroform. Add 25 cc. of iodine solution from a pipette, allowing to drain for a definite time. The excess of iodine should be from 50 per cent to 60 per cent of the amount added, that is, from 100 per cent to 150 per cent of the amount absorbed. Moisten the stopper with a 15 per cent potassium iodide solution to prevent loss of iodine or chlorine but guard against an amount sufficient to run down inside the bottle. Let the bottle stand in a dark place for 1/2 hr. at a uniform temperature. At the end of that time add 20 cc. of 15 per cent potassium iodide solution and 100 cc. of distilled water. Titrate the iodine with _N_/10 sodium thiosulfate solution which is added gradually, with constant shaking, until the yellow color of the solution has almost disappeared. Add a few drops of starch paste and continue titration until the blue color has entirely disappeared. Toward the end of the reaction stopper the bottle and shake violently so that any iodine remaining in solution in the tetrachloride or chloroform may be taken up by the potassium iodide solution. Conduct two determinations on blanks which must be run in the same manner as the sample except that no fat is used in the blanks. Slight variations in temperature quite appreciably affect the titer of the iodine solution, as acetic acid has a high coefficient of expansion. It is, therefore, essential that the blanks and determinations on the sample be made at the same time. The number of cc. of standard thiosulfate solution required by the blank, less the amount used in the determination, gives the thiosulfate equivalent of the iodine absorbed by the amount of sample used in the determination. Calculate to centigrams of iodine absorbed by 1 g. of sample (= per cent iodine absorbed). DETERMINATION, TUNG OIL--Tung oil shows an erratic behavior with most iodine reagents and this is particularly noticeable in the case of the Hanus reagent which is entirely unsuitable for determining the iodine number of this oil since extremely high and irregular results are obtained. The Hübl solution shows a progressive absorption up to 24 hrs. and probably for a longer time but the period required is entirely too long for a chemical determination. The Wijs solution gives good results if the following precautions are observed: Weigh out 0.15 ± 0.05 g., use an excess of 55 ± 3 per cent Wijs solution. Conduct the absorption at a temperature of 20-25° C. for 1 hr. In other respects follow the instructions detailed above. SAPONIFICATION NUMBER (KOETTSTORFER NUMBER). PREPARATION OF REAGENTS. _N/2 Hydrochloric Acid_--Carefully standardized. _Alcoholic Potassium Hydroxide Solution_--Dissolve 40 g. of pure potassium hydroxide in one liter of 95 per cent redistilled alcohol (by volume). The alcohol should be redistilled from potassium hydroxide over which it has been standing for some time, or with which it has been boiled for some time, using a reflux condenser. The solution must be clear and the potassium hydroxide free from carbonates. DETERMINATION--Weigh accurate about 5 g. of the filtered sample into a 250 to 300 cc. Erlenmeyer flask. Pipette 50 cc. of the alcoholic potassium hydroxide solution into the flask, allowing the pipette to drain for a definite time. Connect the flask with an air condenser and boil until the fat is completely saponified (about 30 minutes). Cool and titrate with the _N_/2 hydrochloric acid, using phenolphthalein as an indicator. Calculate the Koettstorfer number (mg. of potassium hydroxide required to saponify 1 g. of fat). Conduct 2 or 3 blank determinations, using the same pipette and draining for the same length of time as above. MELTING POINT. APPARATUS--_Capillary tubes_ made from 5 mm. inside diameter thin-walled glass tubing drawn out to 1 mm. inside diameter. Length of capillary part of tubes to be about 5 cm. Length of tube over all 8 cm. _Standard thermometer_ graduated in tenths of a degree. _600 cc. beaker._ DETERMINATION--The sample should be clear when melted and entirely free from moisture, or incorrect results will be obtained. Melt and thoroughly mix the sample. Dip three of the capillary tubes above described in the oil so that the fat in the tube stands about 1 cm. in height. Now fuse the capillary end carefully by means of a small blast flame and allow to cool. These tubes are placed in a refrigerator over night at a temperature of from 40 to 50° F. They are then fastened by means of a rubber band or other suitable means to the bulb of a thermometer graduated in tenths of a degree. The thermometer is suspended in a beaker of water (which is agitated by air or other suitable means) so that the bottom of the bulb of the thermometer is immersed to a depth of about 3 cm. The temperature of the water is increased gradually at the rate of about 1° per minute. The point at which the sample becomes opalescent is first noted and the heating continued until the contents of the tube becomes uniformly transparent. The latter temperature is reported as the melting point. Before finally melting to a perfectly clear fluid, the sample becomes opalescent and usually appears clear at the top, bottom, and sides before becoming clear at the center. The heating is continued until the contents of the tube become uniformly clear and transparent. This temperature is reported as the melting point.[33] It is usually only a fraction of a degree above the opalescent point noted. The thermometer should be read to the nearest 1/2° C., and in addition this temperature may be reported to the nearest degree Fahrenheit if desired. CLOUD TEST. PRECAUTIONS--(1) The oil must be perfectly dry, because the presence of moisture will produce a turbidity before the clouding point is reached. (2) The oil must be heated to 150° C. over a free flame, immediately before making the test. (3) There must not be too much discrepancy between the temperature of the bath and the clouding point of the oil. An oil that will cloud at the temperature of hydrant water should be tested in a bath of that temperature. An oil that will cloud in a mixture of ice and water should be tested in such a bath. An oil that will not cloud in a bath of ice and water must be tested in a bath of salt, ice, and water. DETERMINATION--The oil is heated in a porcelain casserole over a free flame to 150° C., stirring with the thermometer. As soon as it can be done with safety, the oil is transferred to a 4 oz. oil bottle, which must be perfectly dry. One and one-half ounces of the oil are sufficient for the test. A dry centigrade thermometer is placed in the oil, and the bottle is then cooled by immersion in a suitable bath. The oil is constantly stirred with the thermometer, taking care not to remove the thermometer from the oil at any time during the test, so as to avoid stirring air bubbles into the oil. The bottle is frequently removed from the bath for a few moments. The oil must not be allowed to chill on the sides and bottom of the bottle. This is effected by constant and vigorous stirring with the thermometer. As soon as the first permanent cloud shows in the body of the oil, the temperature at which this cloud occurs is noted. With care, results concordant to within 1/2° C. can be obtained by this method. A Fahrenheit thermometer is sometimes used because it has become customary to report results in degrees Fahrenheit. The oil must be tested within a short time after heating to 150° C. and a re-test must always be preceded by reheating to that temperature. The cloud point should be approached as quickly as possible, yet not so fast that the oil is frozen on the sides or bottom of the bottle before the cloud test is reached. Notes on the Above Methods. SAMPLING. The standard size of sample adopted by the committee is at least 3 lbs. in weight. The committee realizes that this amount is larger than any samples usually furnished even when representing shipments of from 20,000 to 60,000 lbs. but it believes that the requirement of a larger sample is desirable and will work toward uniform and more concordant results in analysis. It will probably continue to be the custom of the trade to submit smaller buyers' samples than required by the committee, but these are to be considered only as samples for inspection and not for analysis. The standard analytical sample must consist of 3 lbs. or more. The reasons for keeping samples in a dark, cool place are obvious. This is to prevent any increase in rancidity and any undue increase in free fatty acids. In the case of many fats the committee has found in its co-operative analytical work that free acid tends to increase very rapidly. This tendency is minimized by low temperatures. MOISTURE AND VOLATILE MATTER. After careful consideration the committee has decided that moisture is best determined in a vacuum oven of the design which accompanies the above report. Numerous results on check samples have confirmed the committee's conclusions. The oven recommended by the committee is constructed on the basis of well-known principles and it is hoped that this type will be adopted generally by chemists who are called upon to analyze fats and oils. The experiments of the committee indicate that it is a most difficult matter to design a vacuum oven which will produce uniform temperatures throughout; and one of the principal ideas in the design adopted is uniformity of temperature over the entire single shelf. This idea has not quite been realized in practice but, nevertheless, the present design approaches much closer to the ideal than other vacuum ovens commonly used. In the drawing the essential dimensions are those between the heating units and the shelf and the length and breadth of the outer casting. The standard Fat Analysis Committee Oven (F. A. C. Oven) can be furnished by Messrs. E. H. Sargent & Company, 125 West Lake street, Chicago. The committee realizes that for routine work a quicker method is desirable and has added one such method and has also stated the conditions under which comparable results can be obtained by means of the ordinary well-ventilated air oven held at 105 to 110° C. However, in accordance with a fundamental principle adopted by the committee at its first meeting, only one standard method is adopted and declared official for each determination. The committee realizes that in the case of all methods for determining moisture by means of loss on heating there may be a loss due to volatile matter (especially fatty acids) other than water. The title of the determination MOISTURE AND VOLATILE MATTER indicates this idea, but any considerable error from this source may occur only in the case of high acid fats and oils and particularly those containing lower fatty acids such as coconut and palm kernel oil. In the case of extracted greases which have not been properly purified, some of the solvent may also be included in the moisture and volatile matter determination, but inasmuch as the solvent, usually a petroleum product, can only be considered as foreign matter, for commercial purposes, it is entirely proper to include it with the moisture. The committee has also considered the various distillation methods for the determination of moisture in fats and oils, but since according to the fundamental principles which it was endeavoring to follow it could only standardize one method, it was decided that the most desirable one on the whole was the vacuum-oven method as given. There are cases wherein a chemist may find it desirable to check a moisture determination or investigate the moisture content of a fat or oil further by means of one of the distillation methods. However, in co-operative work the distillation method in various types of apparatus has not yielded satisfactory results. The difficulties appear to be connected with a proper choice of solvent and particularly with the tendency of drops of water to adhere to various parts of the glass apparatus instead of passing on to the measuring device. When working on coconut oil containing a high percentage of free fatty acids, concordant results could not be obtained by the various members of the committee when working with identical samples, solvents and apparatus. On the other hand, the committee found by individual work, co-operative work and collaborative work by several members of the committee in one laboratory, that the old, well-known direct heating method (which the committee has designated the hot plate method) yielded very satisfactory results on all sorts of fats and oils including emulsions such as butter and oleomargarine and even on coconut oil samples containing 15 to 20 per cent free fatty acids and 5 to 6 per cent of moisture. Unfortunately, this method depends altogether on the operator's skill and while the method may be taught to any person whether a chemist or not so that he can obtain excellent results with it, it is difficult to give a sufficiently, complete description of it so that any chemist anywhere after reading the description could follow it successfully. The method is undoubtedly worthy of much confidence in careful hands. It is quick, accurate and reliable. It is probably the best single method for the determination of moisture in all sorts of samples for routine laboratory work. On account of this fact the committee desires to announce its willingness to instruct any person in the proper use of the method who desires to become acquainted with it and who will visit any committee member's laboratory. INSOLUBLE IMPURITIES. This determination, the title for which was adopted after careful consideration, determines the impurities which have generally been known as dirt, suspended matter, suspended solids, foreign solids, foreign matter, etc., in the past. The first solvent recommended by the committee is hot kerosene to be followed by petroleum ether kept at ordinary room temperature. Petroleum ether, cold or only slightly warm, is not a good fat and metallic soap solvent, whereas hot kerosene dissolves these substances readily, and for this reason the committee has recommended the double solvent method so as to exclude metallic soaps which are determined below as soluble mineral matter. SOLUBLE MINERAL MATTER. Soluble mineral matter represents mineral matter combined with fatty acids in the form of soaps in solution in the fat or oil. Formerly, this mineral matter was often determined in combination by weighing the separated metallic soap or by weighing it in conjunction with the insoluble impurities. Since the soaps present consist mostly of lime soap, it has been customary to calculate the lime present therein by taking 0.1 the weight of the total metallic soaps. The standard method as given above is direct and involves no calculation. The routine method given in the note has been placed among the methods for the reason that it is used in some laboratories, but has not been adopted as a standard method in view of the fact that the committee has made it a rule to adopt only one standard method. It should be pointed out, however, that the method cannot be considered accurate for the reason that insoluble impurities may vary from sample to sample to a considerable extent and the error due to the presence of large particles of insoluble impurities is thus transferred to the soluble mineral matter. The committee has found one type of grease (naphtha bone grease) which shows most unusual characteristics. The type sample contains 4.3 per cent soluble mineral matter by the committee method which would be equivalent to 43.0 per cent free fatty acid. The kerosene and gasoline filtrate was particularly clear, nevertheless the ash was found to contain 36.43 per cent P_{2}O_{5} equivalent to 79.60 per cent of Ca_{3}(PO_{4})_{2} and 9.63 per cent of Fe_{2}O_{3}. The method, therefore, determines the soluble mineral matter in this case satisfactorily but the factor 10 is not applicable for calculating the fatty acids combined therewith. It is necessary, therefore, in order to determine the fatty acids combined with soluble mineral matter in the original sample to determine the actual bases in the soluble mineral matter as obtained by ashing the kerosene and gasoline filtrate. To the bases so determined the factor 10 can then be applied. FREE FATTY ACID. The fatty acid method adopted is sufficiently accurate for commercial purposes. In many routine laboratories the fat or oil is measured and not weighed, but the committee recommends weighing the sample in all cases. For scientific purposes the result is often expressed as "acid number," meaning the number of milligrams of KOH required to neutralize the free acids in one gram of fat, but the commercial practice has been, and is, to express the fatty acids as oleic acid or in the case of palm oil, as palmitic acid, in some instances. The committee sees no objection to the continuation of this custom so long as the analytical report clearly indicates how the free acid is expressed. For a more exact expression of the free acid in a given fat, the committee recommends that the ratio of acid number to saponification number be used. This method of expressing results is subject to error when unsaponifiable fatty matter is present, since the result expresses the ratio of free fatty acid to total saponifiable fatty matter present. TITER. At the present time the prices of glycerol and caustic potash are abnormally high, but the committee has considered that the methods adopted are for normal times and normal prices. For routine work during the period of high prices the following method may be used for preparing the fatty acids and is recommended by the committee: Fifty grams of fat are saponified with 60 cc. of a solution of 2 parts of methyl alcohol to 1 of 50 per cent NaOH. The soap is dried, pulverized and dissolved in 1000 cc. of water in a porcelain dish and then decomposed with 25 cc. of 75 per cent sulphuric acid. The fatty acids are boiled until clear oil is formed and then collected and settled in a 150-cc. beaker and filtered into a 50-cc. beaker. They are then heated to 130° C. as rapidly as possible with stirring, and transferred, after they have cooled somewhat, to the usual 1-in. by 4-in. titer tube. The method of taking the titer, including handling the thermometer, to be followed is the same as that described in the standard method. Even at present high prices many laboratories are using the glycerol-caustic potash method for preparing the fatty acids, figuring that the saving of time more than compensates for the extra cost of the reagents. Caustic soda cannot be substituted for caustic potash in the glycerol method. UNSAPONIFIABLE MATTER. The committee has considered unsaponifiable matter to include those substances frequently found dissolved in fats and oils which are not saponified by the caustic alkalies and which at the same time are soluble in the ordinary fat solvents. The term includes such substances as the higher alcohols, such as cholesterol which is found in animal fats, phytosterol found in some vegetable fats, paraffin and petroleum oils, etc. UNSAPONIFIABLE MATTER should not be confused in the lay mind with INSOLUBLE IMPURITIES OR SOLUBLE MINERAL MATTER. The method adopted by the committee has been selected only after the most careful consideration of other methods, such as the dry extraction method and the wet method making use of the separatory funnel. At first consideration the dry extraction process would seem to offer the best basis for an unsaponifiable matter method, but in practice it has been found absolutely impossible for different analysts to obtain agreeing results when using any of the dry extraction methods proposed. Therefore, this method had to be abandoned after numerous trials, although several members of the committee strongly favored it in the beginning. IODINE NUMBER--The iodine number adopted by the committee is that determined by the well-known Wijs method. This method was adopted after careful comparison with the Hanus and Hübl methods. The Hübl method was eliminated from consideration almost at the beginning of the committee's work for the reason that the time required for complete absorption of the iodine is unnecessarily long and, in fact, even after absorption has gone on over night, it is apparently not complete. In the case of the Hanus and Wijs methods complete absorption takes place in from 15 minutes to an hour, depending on conditions. Formerly, many chemists thought the Hanus solution rather easier to prepare than the Wijs solution, but the experience of the committee was that the Wijs solution was no more difficult to prepare than the Hanus. Furthermore, absorption of iodine from the Wijs solution appeared to take place with greater promptness and certainty than from the Hanus and was complete in a shorter time. Results by the Wijs method were also in better agreement in the case of oils showing high iodine absorption than with the Hanus solution and showed a slightly higher iodine absorption for the same length of time. However, the difference was not great. The committee investigated the question of substitution since it has been suggested that in case of the Wijs solution substitution of iodine in the organic molecule might occur, and found no evidence of this in the time required for the determination, namely, 1/2 hr., or even for a somewhat longer period. One member of the committee felt that it was not desirable to introduce the Wijs method into these standard methods since the Hanus method was already standardized by the Association of Official Agricultural Chemists, but the committee felt that it must follow the principle established at the commencement of its work, namely, that of adopting the method which appeared to be the best from all standpoints, taking into consideration accuracy, convenience, simplicity, time, expense, etc., without allowing precedent to have the deciding vote. IODINE NUMBER, TUNG OIL--The committee has made an extensive study of the application of the Wijs method to the determination of iodine value in the case of tung oil with the result that it recommends the method for this oil but has thought it desirable to limit the conditions under which the determination is conducted rather narrowly, although reasonably good results are obtained by the committee method without making use of the special limitations. The co-operative work of the committee and the special investigations conducted by individual members bring out the following points: _Influence of Temperature_--From 16° C. to 30° C. there is a moderate increase in the absorption, but above 30° the increase is rather rapid so that it was thought best to limit the temperature in the case of tung oil to 20° to 25° C. _Influence of Time_--The absorption increases with the time but apparently complete absorption, so far as unsaturated bonds are concerned, occurs well within one hour's time. Consequently, one hour was set as the practical limit. _Influence of Excess_--The excess of iodine solution also tends to increase the iodine number, hence the Committee thought it necessary to limit the excess rather rigidly to 55 ± 3 per cent, although with greater latitude results were reasonably good. _Influence of Age of Solution_--Old solutions tend to give low results although up to 2 mo. no great differences were observed. Nevertheless, it was thought best to limit the age of the solution to 30 days--long enough for all practical purposes. _Amount of Sample_--As a practical amount of sample to be weighed out the Committee decided on 0.15 g. with a tolerance of 0.05 g. in either direction according to preference. In other words, the amount of sample to be taken for the determination to be from 0.1 to 0.2 g. in the discretion of the analyst. The Committee's study of the Hübl method which has been adopted by the Society for Testing Materials in the case of tung oil indicates that this method when applied to tung oil is subject to the same influences as the Wijs method and it has the additional very serious disadvantage of requiring a long period of time for absorption which cannot be considered reasonable for a modern analytical method. When using the Hübl solution, the absorption is not complete in the case of tung oil at 3, 7, 18 or even 24 hrs. The Hanus method in the case of tung oil gives very high and erratic results, as high as 180 to 240 in ordinary cases for an oil whose true iodine number is about 165. MELTING POINT. A melting point is the temperature at which a solid substance assumes the liquid condition. If the solid is a pure substance in the crystalline condition the melting point is sharp and well defined for any given pressure. With increased pressure the melting point is lowered or raised, depending on whether the substance contracts or expands in melting. The lowering or raising of the melting point with pressure is very slight and ordinarily is not taken into consideration. Melting-point determinations are commonly carried out under ordinary atmospheric pressures without correction. The general effect of soluble impurities is to lower the melting point, and this holds true whether the impurity has a higher or lower melting point than the pure substance (solvent). Thus if a small amount of stearic acid be added to liquid palmitic acid and the solution frozen, the melting point of this solid will be lower than that of palmitic acid. Likewise the melting point of stearic acid is lowered by the addition of a small amount of palmitic acid. A eutectic mixture results when two components solidify simultaneously at a definite temperature. Such a mixture has a constant melting point and because of this and also because both solid and liquid phases have the same composition, eutectic mixtures were formerly looked upon as compounds. The phenomenon of double melting points has been observed in the case of a number of glycerides. Such a glyceride when placed in the usual capillary tube and subjected to increasing temperature quickly resolidifies only to melt again and remain melted at a still higher temperature. This phenomenon has not yet been sufficiently investigated to afford a satisfactory explanation. Non-crystalline substances such as glass, sealing wax and various other waxes and wax mixtures, and most colloidal substances do not exhibit a sharp melting point, but under the application of heat first soften very gradually and at a considerably higher temperature melt sufficiently to flow. This phenomenon of melting through a long range of temperature may be due to the amorphous nature of the substance or to the fact that it consists of a very large number of components of many different melting points. The fats and oils of natural origin, that is, the animal and vegetable fats and oils, consist of mixtures of glycerides and, generally speaking, of a considerable number of such components. These components are crystalline and when separated in the pure state have definite melting points, although some exhibit the phenomenon of double melting point. For the most part the naturally occurring glycerides are mixed glycerides. In the natural fats and oils there are present also certain higher alcohols, of which cholesterol is characteristic of the animal fats and oils and phytosterol of many of the vegetable fats and oils. In addition to the crystalline glycerides and the higher alcohols present in neutral fats, there are in fats of lower grade, fatty acids, which are crystalline, and also various non-crystalline impurities of an unsaponifiable nature, and the presence of these impurities tends to lower the melting point. They also tend to induce undercooling and when the liquid fat or oil is being chilled for purposes of solidification or in determination of titer. The presence of water, especially when this is thoroughly mixed or emulsified with a fat or oil, also influences the melting point to a marked extent, causing the mixture to melt through a longer range of temperatures than would be the case if the water were absent. This is particularly true of emulsified fats and oils, such as butter and oleomargarine, both of which contain, besides water, the solids naturally present in milk or cream and including casein, milk sugar, and salts. The melting-point method recommended by the Committee is not applicable to such emulsions or other watery mixtures and the Committee has found it impossible to devise an accurate method for making softening-point or melting-point determinations on products of this nature. Not only the amount of water present but also the fineness of its particles, that is, its state of subdivision and distribution, in a fat or oil influences the softening point or melting point and causes it to vary widely in different samples. As a consequence of the foregoing facts, natural fats and oils do not exhibit a definite melting point, composed as they are of mixtures of various crystalline glycerides, higher alcohols, fatty acids, and non-crystalline substances. Therefore, the term melting point when applied to them requires further definition. They exhibit first a lower melting point (the melting point of the lowest melting component) or what might be called the softening point and following this the fat softens through a shorter or longer range of temperature to the final melting point at which temperature the fat is entirely liquid. This is the melting point determined by the Committee's melting-point method. The range between the softening point and the final melting point varies greatly with the different fats and oils depending on their chemical components, the water associated with them, emulsification, etc. In the case of coconut oil the range between softening point and final melting point is rather short; in the case of butter, long. Various methods have been devised to determine the so-called melting point of fats and oils. Most of these methods, however, determine, not the melting point, but the softening point or the flow point of the fat and the great difficulty has been in the past to devise a method which would determine even this point with reasonable accuracy and so that results could be easily duplicated. It has been the aim of the Committee to devise a simple method for the determination of the melting point of fats and oils, but it should be understood that the term melting point in the scientific sense is not applicable to natural fats and oils. FOOTNOTES: [22] Approved by the Supervisory Committee on Standard Methods of Analysis of the American Chemical Society. [23] Live steam must not be turned into tank cars or coils before samples are drawn, since there is no certain way of telling when coils are free from leaks. [24] If there is water present under the solid material this must be noted and estimated separately. [25] Boiling point of water at reduced pressures. Pressure Boiling Point Boiling Point Boiling Point Mm. Hg. to 1° C. +15° C. +20° C. 100 52° C. 67° C. 72° C. 90 50 65 70 80 47 62 67 70 45 60 65 60 42 57 62 50 38 53 58 40 34 49 54 [26] Results comparable to those of the Standard Method may be obtained on most fats and oils by drying 5-g. portions of the sample, prepared and weighed as above, to constant weight in a well-constructed and well-ventilated air oven held uniformly at a temperature of 105° to 110° C. The thermometer bulb should be close to the sample. The definition of constant weight is the same as for the Standard Method. [27] The following method is suggested by the Committee for routine control work: Weigh out 5- to 25-g. portions of prepared sample into a glass or aluminum (_Caution_: Aluminum soap may be formed) beaker or casserole and heat on a heavy asbestos board over burner or hot plate, taking care that the temperature of the sample does not go above 130° C. at any time. During the heating rotate the vessel gently on the board by hand to avoid sputtering or too rapid evolution of moisture. The proper length of time of heating is judged by absence of rising bubbles of steam, by the absence of foam or by other signs known to the operator. Avoid overheating of sample as indicated by smoking or darkening. Cool in desiccator and weigh. By co-operative work in several laboratories, the Committee has demonstrated that this method can be used and satisfactory results obtained on coconut oil even when a considerable percentage of free fatty acids is present, and the method is recommended for this purpose. Unfortunately on account of the very great personal factor involved, the Committee cannot establish this method as a preferred method. Nevertheless, after an operator has learned the technique of the method, it gives perfectly satisfactory results for ordinary oils and fats, butter, oleomargarine and coconut oil, and deserves more recognition than it has heretofore received. [28] For routine control work, filter paper is sometimes more convenient than the prepared Gooch crucible, but must be very carefully washed, especially around the rim, to remove the last traces of fat. [29] For routine work, an ash may be run on the original fat, and the soluble mineral matter obtained by deducting the ash on the insoluble impurities from this. In this case the Gooch crucible should be prepared with an ignited asbestos mat so that the impurities may be ashed directly after being weighed. In all cases ignition should be to constant weight so as to insure complete decomposition of carbonates. [30] See note on Soluble Mineral Matter following these methods. When the ash contains phosphates the factor 10 cannot be applied, but the bases consisting of calcium oxide, etc., must be determined, and the factor 10 applied to them. [31] For routine work methyl or denatured ethyl alcohol of approximately 95 per cent strength may be used. With these reagents the end-point is not sharp. [32] P. C. McIlhiney, _J. Am. Chem. Soc._, 29 (1917), 1222, gives the following details for the preparation of the iodine monochloride solution: The preparation of the iodine monochloride solution presents no great difficulty, but it must be done with care and accuracy in order to obtain satisfactory results. There must be in the solution no sensible excess either of iodine or more particularly of chlorine, over that required to form the monochloride. This condition is most satisfactorily attained by dissolving in the whole of the acetic acid to be used the requisite quantity of iodine, using a gentle heat to assist the solution, if it is found necessary, setting aside a small portion of this solution, while pure and dry chlorine is passed into the remainder until the halogen content of the whole solution is doubled. Ordinarily it will be found that by passing the chlorine into the main part of the solution until the characteristic color of free iodine has just been discharged there will be a slight excess of chlorine which is corrected by the addition of the requisite amount of the unchlorinated portion until all free chlorine has been destroyed. A slight excess of iodine does little or no harm, but excess of chlorine must be avoided. [33] The melting point of oils may be determined in general according to the above procedure, taking into consideration the lower temperature required. PLANT AND MACHINERY Illustrations of machinery and layouts of the plant of a modern soap-making establishment. [Illustration: HOIST, LYE TANK, ETC.] [Illustration: MELTING-OUT TROUGH] [Illustration: LAUNDRY SOAP PLANT] [Illustration: DRYING RACK] [Illustration: SOAP KETTLE] [Illustration: REMELTER] [Illustration: CRUTCHER (Cross Section)] [Illustration: HORIZONTAL CRUTCHER] [Illustration: CRUTCHER] [Illustration: WRAPPING MACHINE (LAUNDRY SOAP)] [Illustration: SLABBER] [Illustration: CUTTING TABLE] [Illustration: AUTOMATIC POWER CUTTING TABLE] [Illustration: AUTOMATIC PRESS (LAUNDRY)] [Illustration: CUTTING TABLE (HAND)] [Illustration: CARTON WRAPPING MACHINE] [Illustration: DRYING RACKS] [Illustration: SOAP POWDER BOX] [Illustration: SCOURING SOAP PRESS] [Illustration: FRAME] [Illustration: SOAP POWDER EQUIPMENT] [Illustration: FLUFFY SOAP POWDER EQUIPMENT] [Illustration: SOAP POWDER MIXER] [Illustration: SOAP POWDER MILL] [Illustration: TOILET SOAP EQUIPMENT] [Illustration: TOILET SOAP DRYER] [Illustration: MILLING BOX] [Illustration: AMALGAMATOR] [Illustration: TOILET SOAP MILL] [Illustration: TOILET SOAP MILL] [Illustration: CHIPPER] [Illustration: PLODDER] [Illustration: HORIZONTAL CHIPPER] [Illustration: AMALGAMATOR (IMPROVED)] [Illustration: PRESS (LETTERING ON 4 SIDES OF CAKE)] [Illustration: Press (Foot)] [Illustration: Press (Foot)] [Illustration: PLODDER] [Illustration: AUTOMATIC PRESS (TOILET)] [Illustration: MULTIPLE CAKE CUTTER] [Illustration: CAKE CUTTER] [Illustration: CHIPPER] [Illustration: GLYCERINE DISTILLING PLANT] [Illustration: CRUDE GLYCERINE PLANT] [Illustration: H-A FATTY ACID DISTILLING PLANT] Appendix Tables marked * are taken from the German Year Book for Soap Industry. (U. S. BUREAU OF STANDARDS) THE METRIC SYSTEM. The fundamental unit of the metric system is the meter (the unit of length). From this the units of mass (gram) and capacity (liter) are derived. All other units are the decimal sub-divisions or multiples of these. These three units are simply related, so that for all practical purposes the volume of one kilogram of water (one liter) is equal to one cubic decimeter. ============================================================ | Prefixes. Meaning. | Units. ________________________________________|___________________ | Milli- = one thousandth 1-1000 .001 | Centi- = one hundredth 1-100 .01 | Meter for length. Deci- = one tenth 1-10 .1 | Unit = one 1. | Gram for mass. Deka- = ten 10-1 10. | Hecto- = one hundred 100-1 100. | Liter for capacity. Kilo- = one thousand 1000-1 1000. | ============================================================ The metric terms are formed by combining the words "Meter," "Gram" and "Liter" with the six numerical prefixes. LENGTH 10 milli-meters mm = 1 centi-meter c m 10 centi-meters = 1 deci-meter d m 10 deci-meters = 1 meter (about 40 inches) m 10 meters = 1 deka-meter d k m 10 deka-meters = 1 hecto-meter h m 10 hecto-meters = 1 kilo-meter (about 5/8 mile) k m MASS. 10 milli-grams. m g = 1 centi-gram c g 10 centi-grams = 1 deci-gram d g 10 deci-grams = 1 gram (about 15 grains) g 10 grams = 1 deka-gram d k g 10 Deka-grams = 1 hecto-gram h g 10 hecto-grams = 1 kilo-gram (about 2 pounds) k g CAPACITY. 10 milli-liters. m l = 1 centi-liter c l 10 centi-liters = 1 deci-liter d l 10 deci-liters = 1 liter (about 1 quart) l 10 liters = 1 deka-liter d k l 10 deka-liters = 1 hecto-liter (about a barrel) h l 10 hecto-liters = 1 kilo-liter k l The square and cubic units are the squares and cubes of the linear units. The ordinary unit of land area is the Hectare (about 2-1/2 acres). U.S. BUREAU OF STANDARDS TABLE OF METRIC EQUIVALENTS Meter = 39.37 inches. Legal Equivalent Adopted by Act of Congress July 28, 1866. LENGTH. Centimeter = 0.3937 inch Meter = 3.28 feet Meter = 1.094 yards Kilometer = 0.621 statute mile Kilometer = 0.5396 nautical mile Inch = 2.540 centimeters Foot = 0.305 meter Yard = 0.914 meter Statute mile = 1.61 kilometers Nautical mile = 1.853 kilometers AREA. Sq. centimeter = 0.155 sq. inch Sq. meter = 10.76 sq. feet Sq. meter = 1.196 sq. yards Hectare = 2.47 acres Sq. kilometer = 0.386 sq. mile Sq. inch = 6.45 sq. centimeters Sq. foot = 0.0929 sq. meter Sq. yard = 0.836 sq. meter Acre = 0.405 hectare Sq. mile = 2.59 sq. kilometers WEIGHT. Gram = 15.43 grains Gram = 0.772 U. S. apoth. scruple Gram = 0.2572 U. S. apoth. dram Gram = 0.0353 avoir. ounce Gram = 0.03215 troy ounce Kilogram = 2.205 avoir. pounds Kilogram = 2.679 troy pounds Metric ton = 0.984 gross or long ton Metric ton = 1.102 short or net tons Grain = 0.064 gram U. S. apoth. scruple = 1.296 grams U. S. apoth. dram = 3.89 grams Avoir. ounce = 28.35 grams Troy ounce = 31.10 grams Avoir. pound = 0.4536 kilogram Troy pound = 0.373 kilogram Gross or long ton = 1.016 metric tons Short or net ton = 0.907 metric ton VOLUME. Cu. centimeter = 0.0610 cu. inch Cu. meter = 35.3 cu. feet Cu. meter = 1.308 cu. yards Cu. inch = 16.39 cu. centimeters Cu. foot = 0.283 cu. meter Cu. yard = 0.765 cu. meter CAPACITY. Millimeter = 0.0338 U. S. liq. ounce Millimeter = 0.2705 U. S. apoth. dram Liter = 1.057 U. S. liq. quarts Liter = 0.2642 U. S. liq. gallon Liter = 0.908 U. S. dry quart Dekaliter = 1.135 U. S. pecks Hectoliter = 2.838 U. S. bushels U. S. liq. ounce = 29.57 millimeters U. S. apoth. dram = 3.70 millimeters U. S. liq. quarts = 0.946 liter U. S. dry quarts = 1.101 liters U. S. liq. gallon = 3.785 liters U. S. peck = 0.881 dekaliter U. S. bushel = 0.3524 hectoliter AVOIRDUPOIS WEIGHT. 1 pound = 16 ounces = 256 drams 1 ounce = 16 " TROY (APOTHECARIES') WEIGHT (U. S.) 1 pound = 12 ounces = 96 drams = 288 scruples = 5,760 grains 1 ounce = 8 drams = 24 scruples = 480 grains 1 dram = 3 scruples = 60 grains 1 scruple = 20 grains WINE (APOTHECARIES) LIQUID MEASURE (U. S.) 1 gallon = 8 pints = 128 fl. ozs. = 1,024 fl. drams = 61,440 minims 1 pint = 16 fl. ozs. = 128 fl. drams = 7,689 minims 1 fl. oz. = 8 fl. drams = 480 minims 1 fl. dram = 60 minims _To find diameter of a circle_ multiply circumference by .31831. _To find circumference of a circle_, multiply diameter by 3.1416. _To find area of a circle_, multiply square of diameter by .7854. _To find surface of a ball_, multiply square of diameter by 3.1416. _To find side of an equal square_, multiply diameter by .8862. _To find cubic inches in a ball_, multiply cube of diameter by .5236. _Doubling the diameter of a pipe_, increases its capacity four times. _One cubic foot of anthracite coal_ weighs about 53 lbs. _One cubic foot of bituminous coal_ weighs from 47 to 50 pounds. _A gallon of water_ (U. S. standard) weighs 8-1/3 pounds and contains 231 cubic inches. _A cubic foot of water_ contains 7-1/2 gallons, 1728 cubic inches and weighs 62-1/2 pounds. _To find the number of pounds of water a cylindrical_ tank contains, square the diameter, multiply by .785 and then by the height in feet. This gives the number of cubic feet which multiplied by 62-1/2 gives the capacity in pounds of water. Divide by 7-1/2 and this gives the capacity in gallons. _A horse-power_ is equivalent to raising 33,000 pounds 1 foot per minute, or 550 pounds 1 foot per second. _The friction of water in pipes_ is as the square of velocity. The capacity of pipes is as the square of their diameters; thus, doubling the diameter of a pipe increases its capacity four times. _To find the diameter of a pump cylinder_ to move a given quantity of water per minute (100 feet of piston being the standard of speed), divide the number of gallons by 4, then extract the square root, and the product will be the diameter in inches of the pump cylinder. _To find the horse-power necessary to elevate water_ to a given height, multiply the weight of the water elevated per minute in pounds by the height in feet, and divide the product by 33,000 (an allowance should be added for water friction, and a further allowance for loss in steam cylinder, say from 20 to 30 per cent). _To compute the capacity of pumping engines_, multiply the area of water piston, in inches, by the distance it travels, in inches, in a given time. Deduct 3 per cent for slip and rod displacement. The product divided by 231 gives the number of gallons in time named. _To find the velocity in feet per minute_ necessary to discharge a given volume of water in a given time, multiply the number of cubic feet of water by 144 and divide the product by the area of the pipe in inches. _To find the area of a required pipe_, the volume and velocity of water being given, multiply the number of cubic feet of water by 144 and divide the product by the velocity in feet per minute. The area being found, the diameter can be learned by using any table giving the "area of circles" and finding the nearest area, opposite to which will be found the diameter to correspond. Physical and Chemical Constants of Fixed Oils and Fats. (FROM LEWKOWITSCH AND OTHER AUTHORITIES.) ______________________________________________________________________________ | | | | | | Specific |Specific | Melting- |Solidifying- | | gravity | gravity | point. | point. | | at 15°C. | at 100°C.| C. | C. | _______________________|____________|__________|_____________|_______________| | | | | | Linseed oil | 0.931-0.938| 0.880 | -16° to -26°| -16° | Hemp-seed oil | 0.925-0.931| | | -27° | Walnut oil | 0.925-0.926| 0.871 | | -27° | Poppy-seed oil | 0.924-0.927| 0.873 | | -18° | Sunflower oil | 0.924-0.926| 0.919 | | -17° | Fir-seed oil | 0.925-0.928| | | -27° to -30° | Maize oil | 0.921-0.926| | | -10° to -15° | Cotton-seed oil | 0.922-0.930| 0.867 | | 12° | Sesame oil | 0.923-0.924| 0.871 | | -5° | Rape-seed oil | 0.914-0.917| 0.863 | | -2° to -10° | Black mustard oil | 0.916-0.920| | | -17.5° | Croton oil | 0.942-0.955| | | -16° | Castor oil | 0.960-0.966| 0.910 | | -12° to -18° | Apricot-kernel oil | 0.915-0.919| | | -14° | Almond oil | | 0.915-0.920| | | -10° to -20° | Peanut (arachis) oil | 0.916-0.920| 0.867 | | -3° to -7° | Olive oil | 0.914-0.917| 0.862 | | 2° | Menhaden oil | 0.927-0.933| | | -4° | Cod-liver oil | 0.922-0.927| 0.874 | | 0° to -10° | Seal oil | 0.924-0.929| 0.873 | | 3° | Whale oil | 0.920-0.930| 0.872 | | -2° | Dolphin oil | 0.917-0.918| | | 5° to -3° | Porpoise oil | 0.926 | 0.871 | | -16° | Neat's-foot oil | 0.914-0.916| 0.861 | | 0° to 1.5° | Cotton-seed stearine | 0.919-0.923| 0.867 | 40° | 31° to 32.5° | Palm oil | 0.921-0.925| 0.856 | 27° to 42° | | Cacao butter | 0.950-0.952| 0.858 | 30° to 33° | 25° to 26° | Cocoa-nut oil | 0.925-0.926| 0.873 | 20° to 26° | 16° to 20° | Myrtle wax | 0.995 | 0.875 | 40° to 44° | 39° to 43° | Japan wax | 0.970-0.980| 0.875 | 51° to 54.5°| 46° | Lard | 0.931-0.938| 0.861 | 41° to 46° | 29° | Bone fat | 0.914-0.916| | 21° to 22° | 15° to 17° | Tallow | 0.943-0.952| 0.860 | 42° to 46° | 35° to 37° | Butter fat | 0.927-0.936| 0.866 | 29.5° to 33°| 19° to 20° | Oleomargarine | 0.924-0.930| 0.859 | | | Sperm oil | 0.875-0.884| 0.833 | | -25° | Bottle-nose oil | 0.879-0.880| 0.827 | | | Carnauba wax | 0.990-0.999| 0.842 | 84° to 85° | 80° to 81° | Wool-fat | 0.973 | 0.901 | 39° to 42° | 30° to 30.2° | Beeswax | 0.958-0.969| 0.822 | 62° to 64° | 60.5° to 62° | Spermaceti | 0.960 | 0.812 | 43.5° to 49°| 43.4° to 44.2°| Chinese wax | 0.970 | 0.810 | 80.5° to 81°| 80.5° to 81° | Tung (Chinese wood oil)| 0.936-0.942| | | below -17° | Soya-bean oil | 0.924-0.927| | | 8° to 15° | _______________________|____________|__________|_____________|_______________| Physical and Chemical Constants of Fixed Oils and Fats. (FROM LEWKOWITSCH AND OTHER AUTHORITIES.) Column Headings: A: Saponification value. B: Maumené test. C: Iodine value. D: Hehner value. E: Reichert value. ______________________________________________________________________________ | | | | | | | [A] | [B] | [C] | [D] | [E] | ___________________|_____________|_____________|____________|_________|______| | | | | | | Linseed oil | 190-195 | 104°-111° | 175-190 | | | Hemp-seed oil | 190-193 | 95°-96° | 148 | | | Walnut oil | 195 | 96°-101° | 144-147 | | | Poppy-seed oil | 195 | 86°-88° | 134-141 | 95.38 | | Sunflower oil | 193-194 | 72°-75° | 120-129 | 95 | | Fir-seed oil | 191.3 | 98°-99° | 118.9-120 | | | Maize oil | 188-193 | 56°-60.5° | 117-125 | 89-95.7 | 2.5 | Cotton-seed oil | 191-195 | 68°-77° | 104-110 | 96-17 | | Sesame oil | 189-193 | 64°-68° | 105-109 | 95.8 | 0.35 | Rape-seed oil | 170-178 | 51°-60° | 95-105 | 95 | | Black mustard oil | 174-174.6 | 43°-44° | 96-110 | 95.05 | | Croton oil | 210.3-215 | | 101.7-104 | 89 | 13.5 | Castor oil | 178-186 | 46°-47° | 83.4-85.9 | | 1.4 | Apricot-kernel oil | 192.2-193.1 | 42.5°-46° | 100-107 | | | Almond oil | 190.5-195.4 | 51°-54° | 93-97 | 96.2 | | Peanut (arachis) | | | | | | oil | 190-197 | 45°-49° | 85-98 | 95.86 | | Olive oil | 191-196 | 41.5°-45.5° | 80.6-84.5 | 95.43 | 0.3 | Menhaden oil | 189.3-192 | 123°-128° | 140-170 | | 1.2 | Cod-liver oil | 182-187 | 102°-103° | 154-180 | 95.3 | | Seal oil | 190-196 | 92° | 127-140 | 94.2 | 0.22 | Whale-oil | 188-193 | 91°-92° | 110-136 | 93.5 | 2.04 | Dolphin {Body oil | 197.3 | | 99.5 | 93.07 | 5.6 | oil {Jaw oil | 200 | | 32.8 | 66.28 |65.92 | Porpoise {Body oil | 216-218.8 | 50° | 119.4 | |23.45 | oil {Jaw oil | 253.7 | | 49.6 | 68.41 |65.8 | Neat's-foot oil | 194.3 | 47°-48.5° | 69.3-70.4 | | | Cotton-seed | | | | | | stearine. | 194.6-195.1 | 48° | 88.7-92.8 | 96.3 | | Palm oil | 196.3-202 | | 53-57 | 95.6 | 0.5 | Cacao butter | 192.2-193.5 | | 32-41 | 94.59 | 1.6 | Cocoa-nut oil | 250-253 | | 8.5-9.3 | 88.6 | 3.7 | Myrtle wax | 205.7-211.7 | | 2.9 | | | Japan wax | 220-222.4 | | 4.2-8.5 | 90.6 | | Lard | 195.3-196.6 | 27°-32° | 57-70 | 96 | | Bone fat | 190.9 | | 46.3-49.6 | | | Tallow | 195-198 | | 36-47 | 95.6 | 0.25 | Butter fat | 221.5-227 | | 26-35 | 87.5 |28.78 | Oleomargarine | 194-203.7 | | 55.3-60 | 95-96 | 2.6 | Sperm oil | 132.5-147 | 47°-51° | 84 | | 1.3 | Bottle-nose oil | 126-134 | 41°-47° | 77.4-82 | | 1.4 | Carnauba wax | 80-84 | | 13.5 | | | Wool-fat | 98.2-102.4 | | 25-28 | | | Beeswax | 91-96 | | 8.3-11 | | | Spermaceti | 128 | | | | | Chinese wax | 63 | | | | | Tung (Chinese | | | | | | wood oil) | 193 | | 150-165 | | | Soya-bean oil | 190.6-192.9 | 59°-61° | 121.3-124 | 95.5 | | ___________________|_____________|_____________|____________|_________|______| *Temperature Correction Table for Hehner's Concentrated Bichromate Solution for Glycerine Analysis __________________________________________ | | A | f | Temperature | Corrected Volume | Logarithm | 1 c.c. | ____________|__________________|__________ | | 11° C | 0.9980 ccm | 99913 12° " | 0.9985 " | 99935 13° " | 0.9990 " | 99956 14° " | 0.9995 " | 99978 15° " | 1.0000 " | 00000 16° " | 1.0005 " | 00022 17° " | 1.0010 " | 00043 18° " | 1.0015 " | 00065 19° " | 1.0020 " | 00087 20° " | 1.0025 " | 00108 21° " | 1.0030 " | 00130 22° " | 1.0035 " | 00152 23° " | 1.0040 " | 00173 ____________|__________________|__________ *Table of Important Fatty Acids _______________________________________________________________________________ | | | | | | | | Boiling Point | | | | |______________________| |Neutral- | | Mol. | | | Melt- |ization Name | Formula | Wt. | Ordinary | 100 mm | ing |value | | | Pressure | Pressure | Pt. | Mg. KOH ___________|___________________|______|__________|___________|_______|__________ | | | | | | Butyric | C_{4}H_{8}O_{2} | 88 | 162.3 | | |637.5 Caproic | C_{6}H_{12}O_{2} | 116 | 199.7 | | |483.6 Caprylic | C_{8}H_{16}O_{2} | 144 | 236-237 | | 16.5 |389.6 Capric | C_{10}H_{20}O_{2} | 172 | 268-270 | 199.5-200 | 31.3 |326.2 Lauric | C_{12}H_{24}O_{2} | 200 | | 225 | 43.6 |280.5 Myristic | C_{14}H_{28}O_{2} | 228 | | 250.5 | 53.8 |246.1 Palmitic | C_{16}H_{32}O_{2} | 256 | | 268.5 | 62 |219.1 Stearic | C_{18}H_{36}O_{2} | 284 | | 291 | 69.2 |197.5 Arachidic | C_{20}H_{40}O_{2} | 302 | | | 75 |185.8 Behenic | C_{22}H_{44}O_{2} | 330 | | | 77-78 |170.0 Cerotic | C_{27}H_{54}O_{2} | 400 | | | 78 |140.25 Melissic | C_{30}H_{60}O_{2} | 442 | | | 90 |126.5 Oleic | C_{18}H_{34}O_{2} | 282 | | 185.5-286 | 14 |198.9 Erucic | C_{22}H_{42}O_{2} | 338 | | | 33-34 |165.9 Linolic | C_{18}H_{32}O_{2} | 280 | | | |200.4 Linolenic | C_{18}H_{30}O_{2} | 278 | | | |201.5 Ricinoleic | C_{18}H_{34}O_{3} | 298 | | | |181.6 ___________|___________________|______|__________|___________|_______|__________ *Comparison of Thermometer Scales n Degree Celsius = 4/5n Degree Reaumur = 32 + 9/5n Degree Fahrenheit n Degree Reaumur = 5/4n Degree Celsius = 32 + 9/4n Degree Fahrenheit n Degree Fahrenheit = 5/9 (n - 32) Degree Celsius = 4/9 (n - 32) Deg. R ============================================================================= C. R. F. | C. R. F. | C. R. F. | C. R. F. --------------------|------------------|------------------|------------------ -20 -16 -4 | 20 16 68 | 60 48 140 | 100 80 212 -19 -15.2 -2.2 | 21 16.8 69.8 | 61 48.8 141.8 | 101 80.8 213.8 -18 -14.4 -0.4 | 22 17.6 71.6 | 62 49.6 143.6 | 102 81.6 215.6 -17 -13.6 1.4 | 23 18.4 73.4 | 63 50.4 145.4 | 103 82.4 217.4 -16 -12.8 3.2 | 24 19.2 75.2 | 64 51.2 147.2 | 104 83.2 219.2| | | | -15 -12 5 | 25 20 77 | 65 52 149 | 105 84 221 -14 -11.2 6.8 | 26 20.8 78.8 | 66 52.8 150.8 | 106 84.8 222.8 -13 -10.4 8.6 | 27 21.6 80.6 | 67 53.6 152.6 | 107 85.6 224.6 -12 -9.6 10.4 | 28 22.4 82.4 | 68 54.4 154.4 | 108 86.4 226.4 -11 -8.8 12.2 | 29 23.2 84.2 | 69 55.2 156.2 | 109 87.2 228.2 | | | -10 -8 14 | 30 24 86 | 70 56 158 | 110 88 230 -9 -7.2 15.8 | 31 24.8 87.8 | 71 56.8 159.8 | 111 88.8 231.8 -8 -6.4 17.6 | 32 25.6 89.6 | 72 57.6 161.6 | 112 89.6 233.6 -7 -5.6 19.4 | 33 26.4 91.4 | 73 58.4 163.4 | 113 90.4 235.4 -6 -4.8 21.2 | 34 27.2 93.2 | 74 59.2 165.2 | 114 91.2 237.2 | | | -5 -4 23 | 35 28 95 | 75 60 167 | 115 92 239 -4 -3.2 24.8 | 36 28.8 96.8 | 76 60.8 168.8 | 116 92.8 240.8 -3 -2.4 26.6 | 37 29.6 98.6 | 77 61.6 170.6 | 117 93.6 242.6 -2 -1.6 28.4 | 38 30.4 100.4 | 78 62.4 172.4 | 118 94.4 244.4 -1 -0.8 30.2 | 39 31.2 102.2 | 79 63.2 174.2 | 119 95.2 246.2 | | | 0 0 32 | 40 32 104 | 80 64 176 | 120 96 248 1 0.8 33.8 | 41 32.8 105.8 | 81 64.8 177.8 | 121 96.8 249.8 2 1.6 35.6 | 42 33.6 107.6 | 82 65.6 179.6 | 122 97.6 252.6 3 2.4 37.4 | 43 34.4 109.4 | 83 66.4 181.4 | 123 98.4 253.4 4 3.2 39.2 | 44 35.2 111.2 | 84 67.2 183.2 | 124 99.2 255.2 | | | 5 4 41 | 45 36 113 | 85 68 185 | 125 100 257 6 4.8 42.8 | 46 36.8 114.8 | 86 68.8 186.8 | 126 100.8 258.8 7 5.6 44.6 | 47 37.6 116.6 | 87 69.6 188.6 | 127 101.6 260.6 8 6.4 46.4 | 48 38.4 118.4 | 88 70.4 190.4 | 128 102.4 262.4 9 7.2 48.2 | 49 39.2 120.2 | 89 71.2 192.2 | 129 103.2 264.2 | | | 10 8 50 | 50 40 122 | 90 72 194 | 130 104 266 11 8.8 51.8 | 51 40.8 123.8 | 91 72.8 195.8 | 131 104.8 267.8 12 9.6 53.6 | 52 41.6 125.6 | 92 73.6 197.6 | 132 105.6 269.6 13 10.4 55.4 | 53 42.4 127.4 | 93 74.4 199.4 | 133 106.4 271.4 14 11.2 57.2 | 54 43.2 129.2 | 94 75.2 201.2 | 134 107.2 273.2 | | | 15 12 59 | 55 44 131 | 95 76 203 | 135 108 275 16 12.8 60.8 | 56 44.8 132.8 | 96 76.8 204.8 | 136 108.8 276.8 17 13.6 62.6 | 57 45.6 134.6 | 97 77.6 206.6 | 137 109.6 278.6 18 14.4 64.4 | 58 46.4 136.4 | 98 78.4 208.4 | 138 110.4 280.4 19 15.2 66.2 | 59 47.2 138.2 | 99 79.2 210.2 | 139 111.2 282.2 =============================================================================== *Quantities of Alkali Required for Saponification of Fats of Average Molecular Weight 670 (Cocoanut Oil, Palmkernel Oil) _________________________________________________ | | | | Liters Alkali | Liters Alkali | | Solution | Solution | Kilos | Sp. Gr. 1.1 | Sp. Gr. 1.2 | ______|_____________________|___________________| | | | | | | NaOH | KOH | NaOH | KOH | ______|__________|__________|_________|_________| | | | | | 1000 | 1875.83 | 1902.99 | 844.67 | 930.35 | 2000 | 3751.66 | 3805.97 | 1689.35 | 1860.70 | 3000 | 5627.50 | 5708.96 | 2534.02 | 2791.04 | 4000 | 7508.33 | 7611.94 | 3378.69 | 3721.39 | 5000 | 9379.16 | 9514.93 | 4223.37 | 4651.74 | 6000 | 11254.99 | 11417.91 | 5068.04 | 5582.09 | 7000 | 13130.82 | 13320.90 | 5912.71 | 6512.44 | 8000 | 15006.66 | 15223.88 | 6757.38 | 7442.78 | 9000 | 16882.49 | 17126.87 | 7602.06 | 8373.13 | 10000 | 18758.32 | 19029.85 | 8446.73 | 9303.48 | ______|__________|__________|_________|_________| ______________________________________________ | | | Liters Alkali | Liters Alkali | Solution | Solution Kilos | Sp. Gr. 1.3 | Sp. Gr. 1.355 ______|___________________|___________________ | | | | | NaOH | KOH | NaOH | KOH ______|_________|_________|_________|_________ | | | | 1000 | 510.27 | 622.71 | 409.61 | 517.97 2000 | 1020.54 | 1245.41 | 819.21 | 1035.95 3000 | 1530.81 | 1868.12 | 1228.82 | 1553.92 4000 | 2041.01 | 2490.83 | 1638.43 | 2071.90 5000 | 2551.35 | 3113.54 | 2048.04 | 2589.87 6000 | 3061.61 | 3736.24 | 2457.65 | 3107.84 7000 | 3571.88 | 4358.95 | 2867.26 | 3625.82 8000 | 4082.15 | 4981.66 | 3276.86 | 4143.79 9000 | 4592.42 | 5604.36 | 3886.47 | 4661.77 10000 | 5102.69 | 6227.02 | 4096.08 | 5179.74 ______|_________|_________|_________|_________ *Quantities of Alkali Required for Saponification of Fats of Average Molecular Weight 860 (Tallow, Cottonseed Oil, Olive Oil, Etc.) _________________________________________________ | | | | Liters Alkali | Liters Alkali | | Solution | Solution | Kilos | Sp. Gr. 1.1 | Sp. Gr. 1.2 | ______|_____________________|___________________| | | | | | | NaOH | KOH | NaOH | KOH | ______|__________|__________|_________|_________| | | | | | 1000 | 1461.40 | 1482.56 | 658.05 | 724.81 | 2000 | 2922.81 | 2965.12 | 1316.12 | 1449.61 | 3000 | 4384.21 | 4447.67 | 1974.18 | 2174.42 | 4000 | 5845.62 | 5930.23 | 2632.24 | 2899.22 | 5000 | 7307.02 | 7412.79 | 3290.80 | 3624.03 | 6000 | 8768.42 | 8895.85 | 3948.35 | 4348.84 | 7000 | 10229.83 | 10377.91 | 4606.41 | 5073.64 | 8000 | 11691.23 | 11860.45 | 5264.47 | 5798.45 | 9000 | 13152.64 | 13343.02 | 5922.53 | 6523.25 | 10000 | 14614.04 | 14825.58 | 6580.59 | 7248.06 | ______|__________|__________|_________|_________| ______________________________________________ | | | Liters Alkali | Liters Alkali | Solution | Solution Kilos | Sp. Gr. 1.3 | Sp. Gr. 1.355 ______|___________________|___________________ | | | | | NaOH | KOH | NaOH | KOH ______|_________|_________|_________|_________ | | | | 1000 | 397.54 | 485.13 | 319.11 | 403.54 2000 | 795.07 | 970.27 | 638.23 | 807.08 3000 | 1192.61 | 1455.40 | 957.34 | 1210.61 4000 | 1590.14 | 1940.53 | 1276.45 | 1614.15 5000 | 1987.68 | 2425.67 | 1595.57 | 2017.69 6000 | 2385.21 | 2910.80 | 1914.68 | 2421.23 7000 | 2782.75 | 3395.93 | 2233.79 | 2824.77 8000 | 3180.28 | 3881.06 | 2552.90 | 3228.30 9000 | 3577.82 | 4366.20 | 2872.02 | 3631.84 10000 | 3975.35 | 4851.33 | 3191.13 | 4035.38 ______|_________|_________|_________|_________ DENSITY AND STRENGTH OF SULPHURIC ACID (SIDERSKY). Column Headings: A: Degrees Twaddell B: Sp. Gr. at 15° C. C: % of pure acid (H_{2}SO_{4}). D: Equivalent (in cc.) of a kilo of pure acid. E: Equivalent (in cc.) of a liter of pure acid. ========================================= [A] [B] [C] [D] [E] _________________________________________ 1 1.007 1.9 52.620 96.930 3 1.014 2.8 35.710 66.450 4 1.022 3.8 25.650 47.230 6 1.029 4.8 20.410 37.582 8 1.037 5.8 16.670 30.690 9 1.045 6.8 14.085 25.938 10 1.052 7.8 12.198 22.460 12 1.062 8.8 10.755 19.803 13 1.067 9.8 9.524 17.540 15 1.075 10.9 8.547 15.740 17 1.083 11.9 7.752 14.278 18 1.091 13.0 7.042 12.969 20 1.100 14.1 6.452 11.882 22 1.108 15.2 5.953 10.962 23 1.116 16.2 5.526 10.177 25 1.125 17.3 5.405 9.954 27 1.134 18.5 4.76 8.770 29 1.142 19.6 4.465 8.223 30 1.152 20.8 4.184 7.723 32 1.162 22.2 3.876 7.138 34 1.171 23.3 3.663 6.745 36 1.180 24.5 3.541 6.521 38 1.190 25.8 3.258 5.999 40 1.200 27.1 3.077 5.666 42 1.210 28.4 2.907 5.353 44 1.220 29.6 2.770 5.102 46 1.231 31.0 2.618 4.865 48 1.241 32.2 2.500 4.604 50 1.252 33.4 2.392 4.406 53 1.263 34.7 2.283 4.205 55 1.274 36.0 2.179 4.012 57 1.285 37.4 2.079 3.829 60 1.297 38.8 1.988 3.661 62 1.308 40.2 1.905 3.508 64 1.320 41.6 1.821 3.354 66 1.332 43.0 1.745 3.214 69 1.345 44.4 1.665 3.085 71 1.357 45.5 1.621 2.985 74 1.370 46.9 1.558 2.869 77 1.383 48.3 1.497 2.757 80 1.397 49.8 1.436 2.646 82 1.410 51.2 1.386 2.551 85 1.424 52.6 1.335 2.459 88 1.438 54.0 1.287 2.370 91 1.453 55.4 1.237 2.270 94 1.468 56.9 1.195 2.200 97 1.483 58.3 1.156 2.130 100 1.498 59.6 1.116 2.050 103 1.514 61.0 1.080 1.980 106 1.530 62.5 1.045 1.930 108 1.540 64.0 1.010 1.860 113 1.563 65.5 0.975 1.800 116 1.580 67.0 0.950 1.740 120 1.597 68.6 0.917 1.690 123 1.615 70.0 0.888 1.630 127 1.634 71.6 0.855 1.570 130 1.652 73.2 0.845 1.520 134 1.671 74.7 0.800 1.470 138 1.691 76.4 0.774 1.430 142 1.711 78.1 0.749 1.390 146 1.732 79.9 0.722 1.320 151 1.753 81.7 0.705 1.280 155 1.774 84.1 0.672 1.235 160 1.798 86.5 0.639 1.190 164 1.819 89.7 0.609 1.120 168 1.842 100.0 0.544 1.000 *Densities of Potassium Carbonate Solutions at 15 C (Gerlach) ======================= | | | Per cent | Sp. Gr. | of pure | | K_{2}CO_{3} | ________|_____________| | | 1.00914 | 1 | 1.01829 | 2 | 1.02743 | 3 | 1.03658 | 4 | 1.04572 | 5 | 1.05513 | 6 | 1.06454 | 7 | 1.07396 | 8 | 1.08337 | 9 | 1.09278 | 10 | 1.10258 | 11 | 1.11238 | 12 | 1.12219 | 13 | 1.13199 | 14 | 1.14179 | 15 | 1.15200 | 16 | 1.16222 | 17 | 1.17243 | 18 | 1.18265 | 19 | 1.19286 | 20 | 1.20344 | 21 | 1.21402 | 22 | 1.22459 | 23 | 1.23517 | 24 | 1.24575 | 25 | 1.25681 | 26 | 1.26787 | 27 | 1.27893 | 28 | 1.28999 | 29 | 1.30105 | 30 | 1.31261 | 31 | 1.32417 | 32 | 1.33573 | 33 | 1.34729 | 34 | 1.35885 | 35 | 1.37082 | 36 | 1.38279 | 37 | 1.39476 | 38 | 1.40673 | 39 | 1.41870 | 40 | 1.43104 | 41 | 1.44338 | 42 | 1.45573 | 43 | 1.46807 | 44 | 1.48041 | 45 | 1.49314 | 46 | 1.50588 | 47 | 1.51861 | 48 | 1.53135 | 49 | 1.54408 | 50 | 1.55728 | 51 | 1.57048 | 52 | 1.57079 | 53.024 | ________|_____________| *Constants of Certain Fatty Acids and Triglycerides ========================================================= | | | | | | Per cent Yield Triglycerides | Mol. Wt. | Mol. Wt. |__________________ of | of Fatty | of Tri- | | | of Fatty | glycerides | Fatty | Glycerine | | | Acid | ______________|__________|____________|_______|___________ | | | | Stearic Acid | 284 | 890 | 95.73 | 10.34 Oleic Acid | 282 | 884 | 95.70 | 10.41 Margaric Acid | 270 | 848 | 95.52 | 10.85 Palmitic Acid | 256 | 806 | 95.28 | 11.42 Myristic Acid | 228 | 722 | 94.47 | 12.74 Lauric Acid | 200 | 638 | 94.04 | 14.42 Capric Acid | 172 | 594 | 93.14 | 15.48 Caproic Acid | 116 | 386 | 90.16 | 23.83 Butyric Acid | 88 | 302 | 87.41 | 30.46 ______________|__________|____________|_______|___________ PERCENTAGES OF SOLID CAUSTIC SODA AND CAUSTIC POTASH IN CAUSTIC LYES ACCORDING TO BAUME SCALE. Degrees % % Baumé. NaOH KOH 1 0.61 0.90 2 0.93 1.70 3 2.00 2.60 4 2.71 3.50 5 3.35 4.50 6 4.00 5.60 7 4.556 6.286 8 5.29 7.40 9 5.87 8.20 10 6.55 9.20 11 7.31 10.10 12 8.00 10.90 13 8.68 12.00 14 9.42 12.90 15 10.06 13.80 16 10.97 14.80 17 11.84 15.70 18 12.64 16.50 19 13.55 17.60 20 14.37 18.60 21 15.13 19.50 22 15.91 20.50 23 16.77 21.40 24 17.67 22.50 25 18.58 23.30 26 19.58 24.20 27 20.59 25.10 28 21.42 26.10 29 22.64 27.00 30 23.67 28.00 31 24.81 28.90 32 25.80 29.80 33 26.83 30.70 34 27.80 31.80 35 28.83 32.70 36 29.93 33.70 37 31.22 34.90 38 32.47 35.90 39 33.69 36.90 40 34.96 37.80 41 36.25 38.90 42 37.53 39.90 43 38.80 40.90 44 39.99 42.10 45 41.41 43.40 46 42.83 44.60 47 44.38 45.80 48 46.15 47.10 49 47.58 48.25 50 49.02 49.40 GLYCERINE CONTENT OF MORE COMMON OILS AND FATS USED IN SOAP MAKING. Kind. Theoretical Average Free % Pure Yield Yield of Pure Fatty Acid in Glycerine Soap Lye Glycerine of Commercial in Commercial 80% Crude Neutral Oil Oil. Oil. Glycerine. or Fat. Beef Tallow 10.7 5 10.2 12.75 Bone Grease 10.5 20-50 5.2- 8.4 6.5-10.5 Castor Oil 9.8 0.5-10 8.8- 9.8 11.0-12.45 Cocoanut Oil 13.9 3-5 13.2-13.5 16.5-16.9 Cocoanut Oil Off 15-40 8.3-11.8 10.37-14.75 Corn Oil 10.4 1-10 9.3-10.3 11.62-12.9 Cottonseed Oil 10.6 Trace 10.6 13.25 Hog Grease 10.6 0.5-1 10.5-10.6 13.12-13.25 Horse Grease 10.6 1-3 10.5-10.6 13.12-13.25 Olive Oil 10.3 2-25 7.7-10.2 9.62-12.75 Olive Foots 30-60 4-7 5-8.75 Palm Oil 11.0 10-50 5.5-10 6.87-12.5 Palmkernel Oil 13.3 4-8 12.2-12.8 15.25-16 Peanut Oil 10.4 5-20 8.3-9.9 10.37-12.37 Soya Bean Oil 10.4 2 10.2 12.75 Train Oil 10.0 2-20 8-9.8 10.0-12.25 Vegetable Tallow 10.9 1-3 10.5-10.8 13.12-13.5 *Table of Specific Gravities of Pure Commercial Glycerine with Corresponding Percentage of Water. Temperature 15 C. ------------------+------------------ Sp. Gr. % Water | Sp. Gr. % Water 1.262 0 | 1.160 38 1.261 1 | 1.157 39 1.258 2 | 1.155 40 1.255 3 | 1.152 41 1.2515 4 | 1.149 42 1.250 5 | 1.1464 43 1.2467 6 | 1.1437 44 1.2450 7 | 1.141 45 1.243 8 | 1.1377 46 1.241 9 | 1.1353 47 1.237 10 | 1.1326 48 1.235 11 | 1.1304 49 1.2324 12 | 1.127 50 1.229 13 | 1.125 51 1.2265 14 | 1.1224 52 1.2245 15 | 1.1204 53 1.2225 16 | 1.117 54 1.2185 17 | 1.114 55 1.2174 18 | 1.112 56 1.2142 19 | 1.109 57 1.211 20 | 1.106 58 1.207 21 | 1.103 59 1.203 22 | 1.1006 60 1.2004 23 | 1.088 65 1.198 24 | 1.075 70 1.195 25 | 1.0623 75 1.1923 26 | 1.049 80 1.189 27 | 1.0365 85 1.188 28 | 1.0243 90 1.1846 29 | 1.0218 91 1.182 30 | 1.0192 92 1.179 31 | 1.0168 93 1.176 32 | 1.0147 94 1.1734 33 | 1.0125 95 1.171 34 | 1.01 96 1.168 35 | 1.0074 97 1.165 36 | 1.0053 98 1.163 37 | 1.0026 99 ------------------+------------------ Table of Percentage, Specific Gravity and Beaume Degree of Pure Glycerine Solutions =========+===========+===========++=========+===========+=========== Per cent |Sp. Gr. |Degree ||Per cent |Sp. Gr. |Degree Water |Champion |Beaume ||Water |Champion |Beaume |and Pellet |(Berthelot)|| |and Pellet |(Berthelot) =========+===========+===========++=========+===========+=========== 0 | 1.2640 | 31.2 || 11.0 | 1.2350 | 28.6 0.5 | 1.2625 | 31.0 || 11.5 | 1.2335 | 28.4 1.0 | 1.2612 | 30.9 || 12.0 | 1.2322 | 28.3 1.5 | 1.2600 | 30.8 || 12.5 | 1.2307 | 28.2 2.0 | 1.2585 | 30.7 || 13.0 | 1.2295 | 28.0 2.5 | 1.2575 | 30.6 || 13.5 | 1.2280 | 27.8 3.0 | 1.2560 | 30.4 || 14.0 | 1.2270 | 27.7 3.5 | 1.2545 | 30.3 || 14.5 | 1.2255 | 27.6 4.0 | 1.2532 | 30.2 || 15.0 | 1.2242 | 27.4 4.5 | 1.2520 | 30.1 || 15.5 | 1.2230 | 27.3 5.0 | 1.2505 | 30.0 || 16.0 | 1.2217 | 27.2 5.5 | 1.2490 | 29.9 || 16.5 | 1.2202 | 27.0 6.0 | 1.2480 | 29.8 || 17.0 | 1.2190 | 26.9 6.5 | 1.2465 | 29.7 || 17.5 | 1.2177 | 26.8 7.0 | 1.2455 | 29.6 || 18.0 | 1.2165 | 26.7 7.5 | 1.2440 | 29.5 || 18.5 | 1.2150 | 26.5 8.0 | 1.2427 | 29.3 || 19.0 | 1.2137 | 26.4 8.5 | 1.2412 | 29.2 || 19.5 | 1.2125 | 26.3 9.0 | 1.2400 | 29.0 || 20.0 | 1.2112 | 26.2 9.5 | 1.2390 | 28.9 || 20.5 | 1.2100 | 26.0 10.0 | 1.2375 | 28.8 || 21.0 | 1.2085 | 25.0 10.5 | 1.2362 | 28.7 || | | =========+===========+===========++=========+===========+=========== *Table of Specific Gravities of Pure Glycerine Solutions with Corresponding Beaume Degree and Percent Water --------+--------+-------+---------+--------+-------- Per cent| Sp. Gr.| Degree| Percent | Sp. Gr.| Degree Water | | Beaume| Water | | Beaume --------+--------+-------+---------+--------+-------- | | | | | 0.0 | 1.2640 | 31.2 | 1.0 | 1.2612 | 30.9 0.5 | 1.2625 | 31.0 | 1.5 | 1.2600 | 30.8 2.0 | 1.2585 | 30.7 | 12.0 | 1.2322 | 28.3 2.5 | 1.2575 | 30.6 | 12.5 | 1.2307 | 28.2 3.0 | 1.2560 | 30.4 | 13.0 | 1.2295 | 28.0 3.5 | 1.2545 | 30.3 | 13.5 | 1.2280 | 27.8 4.0 | 1.2532 | 30.2 | 14.0 | 1.2270 | 27.7 4.5 | 1.2520 | 30.1 | 14.5 | 1.2255 | 27.6 5.0 | 1.2505 | 30.0 | 15.0 | 1.2242 | 27.4 5.5 | 1.2490 | 29.9 | 15.5 | 1.2230 | 27.3 6.0 | 1.2480 | 29.8 | 16.0 | 1.2217 | 27.2 6.5 | 1.2465 | 29.7 | 16.5 | 1.2202 | 27.0 7.0 | 1.2455 | 29.6 | 17.0 | 1.2190 | 26.9 7.5 | 1.2440 | 29.5 | 17.5 | 1.2177 | 26.8 8.0 | 1.2427 | 29.3 | 18.0 | 1.2165 | 26.7 8.5 | 1.2412 | 29.2 | 18.5 | 1.2150 | 26.5 9.0 | 1.2400 | 29.0 | 19.0 | 1.2137 | 26.4 9.5 | 1.2390 | 28.9 | 19.5 | 1.2125 | 26.3 10.0 | 1.2375 | 28.8 | 20.0 | 1.2112 | 26.2 10.5 | 1.2362 | 28.7 | 20.5 | 1.2100 | 26.0 11.0 | 1.2350 | 28.6 | 21.0 | 1.2085 | 25.9 11.5 | 1.2335 | 28.4 | | | --------+--------+-------+---------+--------+-------- INDEX A Acetin process for the determination of glycerol, 155. Acid, Clupanodonic, 20. Acid, Hydrochloric, 111. Acid, Lauric, 2. Acid, Myristic, 2. Acid, Napthenic, 24. Acid, Oleic, 15, 19. Acid, Palmitic, 2. Acid, Pinic, 22. Acid, Resin, 144. Acid, Stearic, 15, 19. Acid, Sulfuric, 112. Acid, Sylvic, 22. Acid saponification, 120. Air bleaching of palm oil, 12. Albuminous matter, Removal from tallow, 6. Alcohol, Denatured, 82. Alcoholic method for free alkali in soap, 139. Alkali Blue 6 B, indicator, 129. Alkali, Total, determination of in soap, 147. Alkalis, 25. Alkalis used in soap making, Testing of, 134. Amalgamator, 33. Analysis, Glycerine, International, 150. Analysis, Soap, 137. Analysis, Standard methods for fats and oils, 165-196. Aqueous saponification, 121. Arachis oil, 79. Autoclave saponification, 118. Automobile soaps, 41. B Barrels, sampling, 168. Baumé scale, 25. Bayberry wax, Use in shaving soap, 89. Bichromate Process for glycerol determination, 160. Bleaching, Fullers' earth process for tallow, 4. Bleaching palm oil by bichromate method, 9. Bleaching palm oil by air, 12. Bosshard & Huggenberg method for determination of free alkali, 140. Bunching of soap, 52. C Candelite, 96. Candle tar, 125. Carbolic soap, 77. Carbon Dioxide, Formation of in carbonate saponification, 45. Carbonate, potassium, 29. Carbonate, saponification, 35, 45. Carbonate, sodium, 28. Castile soap, 79. Castor oil ferment, 121. Castor oil, Use of in transparent soaps, 83. Caustic potash, 26. Caustic potash, Electrolytic, 27. Caustic soda, 26. Changes in soap-making, 36. Chemist, Importance of, 127. Chipper, Soap, 32. Chip soap, 54. Chip soap, Cold made, 55. Chip soap, Unfilled, 56. Chrome bleaching of palm oil, 9. Cloud test for oil, Standard method, 182-183. Clupanodonic acid, 20. Cocoanut oil, 6. Cold cream soap, 78. Cold made chip soaps, 55. Cold made toilet soaps, 72. Cold made transparent soaps, 84. Cold process, 35, 43. Colophony, 22. Coloring soap, 75. Copra, 7. Corn oil, 14. Corrosive sublimate, 78. Cotton goods. Soaps used for, 103. Cottonseed oil, 14. Cream, Shaving, 90. Crude glycerine, 113. Crutcher, 32. Curd soap, 71. Cutting table, 32. D Determination of free fatty acid, 128. Determination of unsaponifiable matter, 132. Distillation of fatty acids, 125. Drying machine, 32. E Enzymes, 17. Eschweger soap, 81. Examination of fats and oils, 128. F Fahrion's method for moisture, 138. Fats and oils, Examination of, 128. Fats and oils used in soap manufacture, 3. Fatty acids, 14. Fatty acids, Distillation of, 125. Ferments, Splitting fats with, 121. Fillers for laundry soaps, 53. Fillers for soap powders, 58. Finishing change, 36. Fish oils, 20. Floating soap, 62. Formaldehyde soap, 78. Frames, 31. Free alkali in soap, Determination of, 139. Free fatty acid, Determination of, 128. Free fatty acids, Extraction from tallow, 6. Free fatty acid, Standard method of dilu., 174. Note on method, 188-189. Full boiled soaps, 35. Fullers' earth bleaching of tallow, 4. G Glycerides, 2. Glycerine, 2. Glycerine analysis, 150. Glycerine change, 36. Glycerine, Crude, 113. Glycerine in spent lyes, Recovery of, 106. Glycerine in soap, Determination of, 149. Glycerine, Sampling crude, 162. Glycerine soaps, 83. Glycerol content, Ways of calculating actual, 159. Glycerol determination, Acetin process, 155. Glycerol determination, Bichromate process for, 160. Graining soap, 30. Grease, 21. Grease, Bleaching, 21. Grinding soap, 34. H Hand Paste, 93. Hard water, 29. Hardened oils in toilet soap, Use of, 96. Hydrocarbon oils, 2. Hydrogenating oils, 19. Hydrolysis of fats and oils, 17. Hydrolytic dissociation of soap, 1. Hydrometers, 25. I Indicators, Action, 135-6. Insoluble impurities in fatty oils, Determination of (standard method), 172. Note on method, 187. Insoluble matter in soap, determination of, 143. International committee on glycerine analysis, 150. Iodine manufacturing oil, 191. Iodine member Wijs method, Standard, 177-181. Note on method, 191. Iodine soap, 78. J Joslin, ref., 113. K "Killing" change, 36. Koettstorfer number (Standard method), 181-182. Kontakt reagent, 117. Krebitz Process, 123. Krutolin, 96. L Leiste & Stiepel method for rosin in soap, 146. Liebermann, Storch reaction, 144. Light powders, 60. Laundry soap, 48. LeBlanc Process, 28. Lewkowitsch, ref., 17, 146. Lime saponification, 118. Lime, Use in Krebitz Process, 123. Lime, Use in treatment of glycerine water, 116. Liquid medicinal soaps, 79. Liquid soaps, 94. Lyes, Spent, 37. M Magnesia, Use in autoclave saponification, 120. Manganese sulfate, Use of as catalyzer in fermentative cleavage of fats, 122. Marine soaps, 39. Medicinal soaps, 76. Medicinal soaps, Less important, 78. Medicinal soaps, Therapeutic value of, 76. Melting point of fat or oil, Standard method, 193. Mercury soaps, 78. Metallic soaps, 1. Methyl orange, indicator, 136. Meyerheim, ref., 21. Mill soap, 32. Moisture in soap, Determination of, 138, 130. Moisture and volatile matter in fats and oils, Standard method for detm. of, 170. Note on method, 184-185. Mottle in soap, 81. Mug shaving soap, 90. N Naphtha, Incorporation in soap, 49. Naphthenic acids, 24. Nigre, 36. Normal acids, Equivalent in alkalis, 136. O Oils and fats, 1. Oils and fats, Chemical constants, 18. Oils and fats, Distinction, 1. Oils and fats, Preserving, 18. Oils and fat, Nature of used in soap manufacture, 2. Oils and fats, Rancidity of, 16. Oil hardening, 19. Oleic acid, 15, 19. Olein, 2, 19. Olive oil, 14. Olive oil foots, 14. Organoleptic methods, 127. P Palmatin, 2. Palm kernel oil, 8. Palmitic acid, 2. Palm oil, 8. Palm oil, air bleaching, 12. Palm oil, Chrome bleaching of, 9. Palm oil soap, 66. Pearl ash, 29. Perfuming and coloring toilet soaps, 73. Peroxide soap, 78. Petroff reagent, 117. Pfeilring reagent, 117. Phenol, 77. Phenolphthalein, indicator, 38. Phenolphthalein, Using as indicator, 51. Phenols, Soaps containing, 77. Pinic acid, 22. Plodder, 33. Potash from wood ash, 27. Potassium carbonate, 29. Powders, Light, 60. Powders, Scouring, 61. Powders, Shaving, 90. Powders, Soap, 56. Precipitation test for treated spent lyes, 110. Prevention of rancidity, 18. Pumice or sand soaps, 93. Purple shade in soap, 75. R Rancidity of oils and fats, 16. Rancidity, Prevention, 18. Recovery of glycerine from spent lye, 106. Red oil, 15. Red oil, Saponified, 15. Resin acids, Total fatty and, Determination of in soap, 144. Ribot, ref., 20. Rosin, 22. Rosin, Determination of in soap, 144. Rosin saponification, 23. Run and glued up soaps, 69. Run soaps, 39. S Sal soda, 29. Salt, 30. Salting out, 30. Salt "pickle," 37. Sampling crude glycerine, 162. Sampling for standard method, 166. Note on, 184. Sampling oils and fats, 128. Sampling soap, 137. Saponification by ferments, 121. Saponification, Acid, 120. Saponification, Aqueous, 121. Saponification, Autoclave, 118. Saponification, Carbonate, 45. Saponification defined, 2, 105. Saponification, Lime, 118. Saponification number, 181-182. Saponification, Rosin, 23. Saponification, Various methods, 105. Scouring and fulling soaps for wool, 98. Scouring powders, 61. Scouring soap, 61. Semi-boiled laundry soaps, 49. Semi-boiled process, 44. Shaving cream, 90. Shaving powder, 90. Shaving soaps, 87. Silica and silicates, Determination of in soap, 148. Silk dyeing, 102. Silk industry, Soaps used in, 101. Slabber, 32. Smith method for moisture in soap, 138. Soap analysis, 137. Soap, Automobile, 41. Soap, Carbolic, 71. Soap, Castile, 79. Soap, Chip, 54. Soap Chip, cold made, 55. Soap, Chip, unfilled, 56. Soap, Cold cream, 78. Soap, Coloring, 75. Soap containing phenols, 77. Soap, Curd, 71. Soap, Defined, 1. Soap, Determination insoluble matter, 143. Soap, Determining glycerine in, 149. Soap, Eschweger, 81. Soap, Floating, 62. Soap, Formaldehyde, 78. Soap for wool, Scouring and fulling, 98. Soap, Full boiled, 35. Soap, Iodine, 78. Soap kettle, 31. Soap, Laundry, 48. Soap, Liquid, 94. Soap lye crude glycerine, 113. Soap, Marine, 39. Soap, Medicinal, 76. Soap, Medicinal, less important, 78. Soap, Mercury, 78. Soap, Metallic, 1. Soap, Peroxide, 78. Soap powders, 56. Soap, Pumice or sand, 93. Soap, Rosin settled, 50. Soap, Run and glued up, 69. Soap, Scouring, 61. Soap, Semi-boiled laundry, 49. Soap, Shaving, 87. Soap, Sulphur, 77. Soap, Tannin, 78. Soap, Tar, 77. Soap, Test for color of, 133. Soap, Textile, 98. Soap, Toilet, 65. Soap, Toilet cheaper, 68. Soap, Toilet, cold made, 72. Soap, Toilet perfuming and coloring, 73. Soap, Transparent, 82. Soap, Transparent, cold made, 84. Soap used for cotton goods, 103. Soap used in the silk industry, 101. Soap, Witch hazel, 78. Soap, Wool thrower's, 100. Soap, Worsted finishing, 101. Soda ash, 28. Sodium carbonate, 28. Sodium perborate, Use of in soap powders, 57. Soft soaps, 40. Soluble mineral matter detm. of in fats and oils, 173. Note on method, 187-188. Solvay process, 28. Soya bean oil, 14. Spent lye, Recovery of glycerine from, 106. Spent lyes, 37. Spent lyes, Treatment of for glycerine recovery, 107. Splitting fats with ferments, 121. Standard methods of analysis for fats and oils, 165-196. Starch and gelatine, Determination in soap, 143. Stearic acid, 15, 19. Stearin, 2, 19. Strengthening change, 36. Strengthening lyes, 38. Strunz crutcher, 63. Sugar in soap, Determination of, 150. Sugar, Use in transparent soap, 83. Sulfate of alumina, Use of in spent lyes, 108. Sulphonated oils, 104. Sulphur soaps, 77. Sweating of soap, 62. Sweet water, 119. Sylvic acid, 22. T Talgol, 96. Tallow, 4. Tallow, Fullers' earth bleaching of, 4. Tallow, Improving color by extraction of free fatty acid, 6. Tannin soap, 78. Tar soap, 77. Test for color of soap, 133. Testing of alkalis used in soap making, 134. Textile soaps, 98. Titer, 130. Tank cars, Sampling, 166. Tierces, Sampling, 168. Titer, Standard method, 175. Titer, Note on, 189. Tung oil, Note one iodine, number of, 180. Toilet soap, 65. Toilet soaps, Cheaper, 68. Toilet soap, Use of hardened oils in, 96. Total alkali, Determination of in soap, 147. Total fatty and resin acids, Determination of in soap, 144. Train oils, 20. Transparent soap, 82. Transparent soap, Cold made, 84. Troweling soap, 52. Tsujimoto, ref., 20. Tubes for transparent soap, 85. Turkey red oil, 104. Twaddle scale, 25. Twitchell method for rosin, 145. Twitchell process, 113. Twitchell process, Advantages, 113. U Unsaponifiable matter, Determination of in oils and fats, 132. Unsaponifiable matter, Determination of in soap, 148. Unsaponifiable matter, determination of by standard method, 176. V Vacuum Oven, Standard, 176. Vegetable oils, 6. W Water, 29. Water, Hard, 29. Witch hazel soap, 78. Wool thrower's soap, 100. Worsted finishing soaps, 101. Z Zinc oxide, Use of in autoclave saponification, 120. Zinc oxide, Use of in soap, 33. LITERATURE OF THE CHEMICAL INDUSTRIES On our shelves is the most complete stock of technical, industrial, engineering and scientific books in the United States. The technical literature of every trade is well represented, as is also the literature relating to the various sciences, both the books useful for reference as well as those fitted for students' use as textbooks. A large number of these we publish and for an ever increasing number we are the sole agents. ALL INQUIRIES MADE OF US ARE CHEERFULLY AND CAREFULLY ANSWERED AND COMPLETE CATALOGS AS WELL AS SPECIAL LISTS SENT FREE ON REQUEST D. VAN NOSTRAND COMPANY _Publishers and Booksellers_ 8 WARREN STREET NEW YORK The Soap-Maker's Book Shelf A list of standard books relating to soapmaking and allied industries. Published and For Sale by D. VAN NOSTRAND COMPANY _Publishers and Booksellers_ 8 WARREN STREET NEW YORK ~Askinson, George W.~ Perfumes and Cosmetics. Their preparation and manufacture. Fourth Edition, translated from the German, and revised with additions by W. L. Dudley. 32 illustrations. 6-1/4 � 9-1/2. Cloth. 354 pp. New York, 1915. ~$5.00~ ~Chalmers, T. W.~ The Production and Treatment of Vegetable Oils. Including chapters on the refining of oils, the hydrogenation of oils, the generation of hydrogen, soap making, the recovery and refining of glycerine, and the splitting of oils. 95 illustrations, 9 folding plates. 8 � 11-1/2. Cloth. 163 pp. London, 1919. ~$7.50~ ~Deite, C.~ Manual of Toilet Soap-Making. Comprising toilet soaps, medicated soaps, and other specialties. Second Revised Edition. 85 illustrations. 6-1/2 � 10. Cloth. 356 pp. London, 1920. ~$7.50~ ~Ellis, Carleton G.~ The Hydrogenation of Oils, Catalyzers and Catalysis and the Generation of Hydrogen and Oxygen. Second Edition, thoroughly revised and enlarged. 240 illustrations. 6-1/4 � 9-1/2. Cloth. 767 pp. N. Y., 1919. ~$7.50~ ~Fischer, M. H.~ Soaps and Proteins, Their Colloid Chemistry in Theory and Practice. With the collaboration of G. D. McLaughlin and M. O. Hooker. 114 illustrations. 6 � 9-1/4. Cloth. 281 pp. New York, 1921. ~$4.00~ ~Holde, D.~ The Examination of Hydrocarbon Oils, and of the Saponifiable Fats and Waxes. Translated from the Fourth German Edition by Edward Mueller. 115 illustrations. 6-1/4 � 9-1/4. Cloth. 499 pp. N. Y., 1915. ~Net, $5.00~ ~Hurst, G. H~. Soaps. A practical manual of the manufacture of domestic, toilet and other soaps. Second Edition. 66 illustrations. 6 � 8-3/4. Cloth. 385 pp. London, 1907. ~$6.00~ ~Hurst, George H., and Simmons, W. H.~ Textile Soaps and Oils. A handbook on the preparation, properties, and analysis of the soaps and oils and in textile manufacturing, dyeing and printing. Third Edition, revised. 12 illustrations. 5-1/2 � 8-3/4. Cloth. 212 pp. London, 1921. ~$4.00~ ~Koller, T. Cosmetics.~ A handbook of the manufacture, employment, and testing of all cosmetic materials and cosmetic specialties, with numerous recipes. Translated from the German. Third Edition. 5 � 7-1/2. Cloth. 264 pp. London, 1920. ~$3.50~ ~Koppe, S. W. Glycerine.~ Its introduction, Uses and Examination. For chemists, perfumers, soapmakers, pharmacists, and explosives technologists. 7 illustrations. 5-1/4 � 7-1/2. Cloth. 260 pp. New York, 1915. ~$3.50~ ~Lamborn, L. L.~ Modern Soaps, Candles, and Glycerin. A practical manual of modern methods of utilization of fats and oils in the manufacture of soaps and candles, and the recovery of glycerin. 228 illustrations. 6-1/2 � 9-1/4. Cloth. 708 pp. N. Y., 1906. ~$10.00~ ~Murray, B. L.~ Standards and Tests for Reagent Chemicals. 6 � 9. Cloth. 400 pp. New York, 1920. ~$3.00~ ~Parry, Ernest J.~ The Chemistry of Essential Oils and Artificial Perfumes. Vol. I, Monographs on Essential Oils. Fourth Edition, revised and enlarged. 51 illustrations. 6-1/4 � 10. Cloth. 557 pp. London, 1921. ~$9.00~ Vol. II. Constituents of Essential Oils, Synthetic Perfumes and Isolated Aromatics, and the Analysis of Essential Oils. Third Edition, revised and enlarged. Illustrated. 351 pp. London, 1919. ~$7.00~ ~Partington, J. R.~ The Alkali Industry. 63 illustrations. 5-1/2 � 8-1/2. Cloth. 318 pp. London, 1918. ~$3.00~ ~Rogers, Allen.~ Industrial Chemistry. A manual for the student and manufacturer. Third Edition, thoroughly revised and enlarged. 377 illustrations. 6-1/2 � 9-3/4. Flexible fabrikoid. 1255 pp. New York, 1920. ~$7.50~ ~Scott, Wilfred W.~ (Editor). Standard Methods of Chemical Analysis. A manual of analytical methods and general reference for the analytical chemist and for the advanced student. Second Edition, revised, with additional tables. 142 illustrations, 3 color plates. 7 � 9-1/4. Cloth. 900 pp. N. Y., 1917. ~$7.50~ ~Simmons, W. H.~ Fats, Waxes and Essential Oils. ~In Press.~ ~Simmons, William H.~ Soap. Its composition, manufacture and properties. 11 illustrations. 4-3/4 � 7-1/4. Cloth. 133 pp. London, 1916. ~$1.00~ ~Simmons, W. H., and Appleton, H. A.~ The Handbook of Soap Manufacture. 27 illustrations. 6 � 9. Cloth. 166 pp. London, 1908. ~$4.00~ ~Van Nostrand's Chemical Annual.~ Edited by John C. Olsen. A handbook of useful data for analytical manufacturing and investigating chemists and chemical students. Fourth Issue, enlarged. 5 � 7-1/2. Flexible fabrikoid. 785 pp. New York, 1918. ~$3.00~ ~Watt, A.~ Art of Soapmaking. A practical handbook of the manufacture of hard and soft soaps, toilet soaps, etc. Seventh Edition, revised and enlarged. 43 illustrations. 5-1/4 � 7-1/2. Cloth. 323 pp. London, 1918. ~$4.00~ ~Wright, C. R. A.~ Animal and Vegetable Fixed Oils, Fats, Butters, and Waxes: Their Preparation and Properties, and the Manufacture Therefrom of Candles, Soaps, and Other Products. Third Edition, revised and greatly enlarged by C. Ainsworth Mitchell. 185 illustrations, 3 plates. 6 � 9. Cloth. 953 pp. London, 1921. ~$16.50~ 
37420	----	+------------------------------------------------------------------+ | TRANSCRIBER'S NOTES | | | | * Where the original work uses text in italics or bold face, this| | e-text uses _text_ and =text=, respectively. Small caps in the | | original work are represented here in all capitals. Subscripts | | are represented as _{subscript}. | | * Footnotes have been moved to directly below the paragraph or | | table to which they belong. | | * Several tables have been split, transposed or otherwise re- | | arranged to make them fit within the available width. | | | | More Transcriber's Notes will be found at the end of this text. | +------------------------------------------------------------------+ PAINT TECHNOLOGY AND TESTS Published by the McGraw-Hill Book Company New York Successors to the Book Departments of the McGraw Publishing Company Hill Publishing Company Publishers of Books for Electrical World The Engineering and Mining Journal Engineering Record American Machinist Electric Railway Journal Coal Age Metallurgical and Chemical Engineering Power PAINT TECHNOLOGY AND TESTS. BY HENRY A. GARDNER _Assistant Director, The Institute of Industrial Research, Washington, D. C._ _Director, Scientific Section, Paint Manufacturers' Association of the United States, etc._ McGRAW-HILL BOOK COMPANY 239 WEST 39TH STREET, NEW YORK 6 BOUVERIE STREET, LONDON, E.C. 1911 _Copyright, 1911, by the_ MCGRAW-HILL BOOK COMPANY THE·PLIMPTON·PRESS·NORWOOD·MASS·U·S·A TO MY MOTHER PREFACE A few years ago the producer and consumer of paints possessed comparatively little knowledge of the relative durability of various pigments and oils. There existed in some cases a prejudice for a few standard products, that often held the user in bondage, discouraging investigation and exciting suspicion whenever discoveries were made, that brought forth new materials. Such conditions indicated to the more progressive, the need of positive information regarding the value of various painting materials, and the advisability of having the questions at issue determined in a practical manner. The desire that such work should be instituted, resulted in the creation of a Scientific Section, the scope of which was to make investigations to determine the relative merits of different types of paint, and to enlighten the industry on various technical problems. Paint exposure tests of an extensive nature were started in various sections of the country where climatic conditions vary. This field work was supplemented in the laboratory by a series of important researches into the properties of pigments, oils, and other raw products entering into the manufacture of protective coatings. The results of the work were published in bulletin form and given wide distribution. The demand for these bulletins early exhausted the original impress, and a general summary therefore forms a part of this volume. The purpose of the book is primarily to serve as a reference work for grinders, painters, engineers, and students; matter of an important nature to each being presented. Without repetition of the matter found in other books, two chapters on raw products have been included, and they present in condensed form a summary of information that will prove of aid to one who desires to become conversant with painting materials with a view to continuing tests such as are outlined herein. In other chapters there has been compiled considerable matter from lectures and technical articles presented by the writer before various colleges, engineering societies, and painters' associations. The writer wishes to gratefully acknowledge the untiring efforts of the members of the Educational Bureau of the Paint Manufacturers' Association, whose early endeavors made possible many of the tests described in this volume. Kind acknowledgment is also made to members of the International Association of Master House Painters and Decorators of the United States and Canada, who stood always ready to aid in investigations which promised to bring new light into their art and craft. HENRY A. GARDNER. WASHINGTON, October, 1911. CONTENTS CHAPTER PAGE I PAINT OILS AND THINNERS 1 II A STUDY OF DRIERS AND THEIR EFFECT 21 III PAINT PIGMENTS AND THEIR PROPERTIES 42 IV PHYSICAL LABORATORY PAINT TESTS 70 V THE THEORY AND PRACTICE OF SCIENTIFIC PAINT MAKING 93 VI THE SCOPE OF PRACTICAL PAINT TESTS 105 VII CONDITIONS NOTED AT INSPECTION OF TESTS 114 VIII RESULTS OF ATLANTIC CITY TESTS 124 IX RESULTS OF PITTSBURG TESTS 135 X A LABORATORY STUDY OF TEST PANELS 149 XI ADDITIONAL TESTS AT ATLANTIC CITY AND PITTSBURG 174 XII NORTH DAKOTA PAINT TESTS 182 XIII TENNESSEE PAINT TESTS 201 XIV WASHINGTON PAINT TESTS 207 XV CEMENT AND CONCRETE PAINT TESTS 214 XVI STRUCTURAL STEEL PAINT TESTS 220 XVII THE SANITARY VALUE OF WALL PAINTS 252 PAINT TECHNOLOGY CHAPTER I PAINT OILS AND THINNERS =Constants and Characteristics of Oils and Their Effect upon Drying.= An attempt has been made to give in this chapter a brief summary of the most important characteristics of those oils finding application in the paint and varnish industry. For methods of oil analysis, the reader is referred to standard works on this subject; the analytical constants herein being given only for comparative purposes. It is well known that one of the most desirable features of a paint oil is the ability to set up in a short period to a hard surface that will not take dust. This drying property is dependent upon the chemical nature of the oil. If it is an unsaturated compound, like linseed oil, rapid absorption of oxygen will cause the film to dry rapidly and become hard. If the oil be of a fully satisfied nature, like mineral oil, oxygen cannot be taken up to any great extent and drying will not take place. The various animal and vegetable oils differ in their power of oxygen absorption to a lesser or greater extent. This difference is referred to by the chemist in terms of the iodine value. The iodine value of linseed oil is approximately 190, meaning that one gram of the oil will take up 190 centigrams of iodine. Oils with high iodine values have good drying powers, while those with low iodine values are, as a rule, very slow drying in nature. For a description of the working and drying properties of various oils used in paints, see Chapter XIV. The oxygen absorption of various oils and mixtures is shown in Chapter II. =Linseed Oil.= The seed of the flax plant which is extensively grown in North Dakota, Argentine Republic and Russia, contains approximately 36% of oil which may be obtained by grinding, heating, and expression. Ripe native seed generally produces a pale oil of little odor; the oil from Argentine seed often having a greenish tint and an odor resembling sorghum. While filtering, pressing and ageing will remove considerable of the ("foots") mucilaginous matter, phosphates, silica, etc., from the oil, the better grades which are intended for varnish making are often refined with sulphuric acid. A light colored oil which may be heated without "breaking" results from this treatment, but such oils are apt to contain considerable free fatty acid, unless they are washed with alkali subsequent to the sulphuric acid treatment. On account of its rapid drying properties and general adaptability for all classes of paints and varnishes, linseed oil has never been supplanted by any other oil. Chemically it consists of the glycerides of linoleic, oleic, and isolinoleic acid, its constitution being responsible for its very high iodine value. [Illustration: Field of Flax in bloom in North Dakota] Boiled linseed oil, a heavier and darker product, is made by heating the raw oil in open kettles to high temperatures, generally with the addition of metallic driers such as litharge, and black manganese. The resinates of lead and manganese are often added to oil heated at a lower temperature, to obtain a boiled oil of lighter color. [Illustration: New type of Flax Harvester which pulls plant up by the roots, thus preventing infection of soil] [Illustration: Modern Concrete Elevators for storing Flaxseed] [Illustration: View of Linseed Oil Factory showing hydraulic press, tanks, etc.] [Illustration: _Photographs courtesy of Spencer Kellogg Sons_ Flaxseed Crushers] [Illustration: Filter Presses for removing extraneous matter from linseed oil] [Illustration: Linseed Cake from Oil Press] [Illustration: Glycine Hispida Mammoth soya bean plants] [Illustration: _Photographs courtesy of David Fairchild, Plant Explorer, U. S. Dept. of Agriculture_ Glycine Hispida Soya bean plants under cultivation at Arlington, Va.] By blowing air through linseed oil that has been heated to approximately 200 degrees Fahrenheit, either with or without drier, heavy bodied oils are obtained, which find special application in varnishes and technical paints. As the viscosity of these oils increase, the iodine values decrease, and a slight rise in saponification value and specific gravity is observed. The following analyses of various types of linseed oil were recently made by the writer: ===========+========+========+=========+========+=========+========= |Pure Raw| Boiled | Boiled | Blown | Litho. | Old |Linseed | L. O. | L. O. | L. O. | L. O. |Treated | Oil | (Lino- | (Resin- | | | Oil | | leate) | ate) | | | -----------+--------+--------+---------+--------+---------+--------- Color | Amber | Dark | Reddish | Pale | Dark | Amber | Clear | Brown | Brown | | Brown | Clear | | | | | | Sp. Gr. at | .933 | .941 | .930 | .968 | .970 | .943 15° C. | | | | | | |Average | | | | | Iodine No. | 180 | 172 | 176 | 133 | 102 | 172 | | | | | | Saponifi- | 191 | 187 | 186 | 189 | 199 | 197 cation No. | | | | | | | | | | | | Free Fatty | 3.2 | 2.7 | 2.2 | 2.8 | 2.7 | 6.9 Acid | | | | | | | | | | | | Unsaponi- | 1.4 | -- | -- | -- | -- | 1.8 fiable | | | | | | | | | | | | Maumene | 111 | -- | -- | -- | -- | 96 | | | | | | Moisture | .2% | -- | -- | -- | -- | none ===========+========+========+=========+========+=========+========= [Illustration: Glycine Hispida Mammoth soya bean plant] [Illustration: Glycine Hispida Soya bean plant, showing nitrogen gathering tubercles on roots] =Soya Bean Oil.= The soya plant which is extensively cultivated in Asia produces a seed bearing up to 22% and over of a golden colored oil having a peculiar leguminous odor. The oil, which probably consists of the glycerides of oleic, linoleic, and palmitic acids, is secured by crushing, steaming and pressing the seed. There are several varieties of the plant, and they are said to be the best annual legume for forage, the straw and fruit being rich in nitrogen and very fattening as a cattle food. Soya may be grown in nearly any country and is a great carrier of nitrogen to land deficient in this element. Although the oil has been used abroad for many years for soap-making purposes, its use as a drying oil is comparatively recent; being introduced into the paint industry of the United States during the year 1909, when linseed oil started on its phenomenal rise in price. The oil has given fair service in some paints when mixed with upwards of 75% of pure linseed oil. It is of a semi-drying nature, but may be made to dry rapidly when mixed with manganese and lead linoleate driers. By compounding it under heat with tung oil and rosin, a substitute for linseed oil is produced, which some claim to be quite valuable. Table I gives the constants of several samples of soya oil examined by the writer. Table II shows the iodine value of mixtures of soya and linseed oils. Table III shows the results of drying experiments on soya oils containing different percentages of lead and manganese driers. TABLE I CHEMICAL CHARACTERISTICS OF SOYA BEAN OIL =======+==========+===========+============+==========+=========== Sample | Specific | Acid No. | Saponifi- | Iodine |Per cent. No. | gravity | | cation | No. | of foots | | | No. | | -------+----------+-----------+------------+----------+----------- 1 | 0.9233 | 1.87 | 188.4 | 127.8 | 3.81 2 | 0.9240 | 1.92 | 188.3 | 127.2 | -- 3 | 0.9231 | 1.90 | 187.8 | 131.7 | -- 4 | 0.9233 | 1.91 | 188.4 | 129.8 | -- 5 | -- | -- | -- | 130.0 | -- 6 | -- | -- | -- | 132.6 | -- 7 | -- | -- | -- | 136.0 | -- Average| 0.9234 | 1.90 | 188.2 | 130.7 | -- =======+==========+===========+============+==========+=========== TABLE II IODINE VALUES OF LINSEED OIL AND MIXED OILS ==============+============+============+============+============ | | Soya | Soya | Soya Sample No. | Straight |25 per cent.|50 per cent.|75 per cent. | linseed | Linseed | Linseed | Linseed | |75 per cent.|50 per cent.|25 per cent. --------------+------------+------------+------------+------------ 1 | 190.3 | 175.2 | 160.7 | 140.4 2 | 189.5 | 175.9 | 161.7 | 140.8 3 | 188.0 | 175.4 | 160.3 | 139.0 --------------+------------+------------+------------+------------ Average | 189.3 | 175.5 | 160.9 | 140.4 ==============+============+============+============+============ TABLE III SOYA BEAN OIL AND LEAD DRIER =========+==========+====+====+====+====+====+====+====+==== Per cent.| | | | | | | | | PbO | |0.05|0.10|0.30|0.50|0.70|1.00|1.30|1.60 ---------+----------+----+----+----+----+----+----+----+---- | { 1 day | -- |0.07|0.63|1.34|1.05|1.53|0.93|1.35 | { 3 days| -- |0.07|3.52|4.31|2.75|4.86|4.82|4.12 Per ct. | { 5 days| -- |0.09|5.04|6.06|6.09|6.75|6.66|5.52 gain | { 12 days| -- | -- |6.88|7.54|7.43|7.76|7.32|6.47 | { 15 days| -- | -- |8.84|8.93|8.59|8.81|8.44|7.46 | { 20 days|0.05|0.20|9.02|9.08|8.90|9.03|8.65|7.83 ---------+----------+----+----+----+----+----+----+----+---- SOYA BEAN OIL AND MANGANESE DRIER -----------------+----------+----+----+----+----+---- Per cent. MnO_{2}| |0.01|0.05|0.15|0.26|0.30 -----------------+----------+----+----+----+----+---- | { 1 day | -- | -- |0.02|0.02|0.01 Per ct. gain | { 10 days| -- |5.06|6.48|6.10|5.97 | { 20 days|0.05|9.07|8.80|6.78|6.51 -----------------+----------+----+----+----+----+---- SOYA BEAN OIL, MANGANESE AND LEAD DRIER -------------+----------+----+----+---- Per cent. PbO| |0.20|0.30|0.50 -------------+----------+----+----+---- MnO_{2} | |0.05|0.15|0.25 -------------+----------+----+----+---- | { 1 day |3.04|3.77|3.74 Per ct. gain | { 8 days|5.96|6.43|6.47 | { 12 days|6.33|6.78|6.67 =============+==========+====+====+==== =Tung Oil.= There are grown in China and Japan many varieties of the "aleurites cordata," popularly known as the tung tree. This tree bears great quantities of large sized nuts containing as high as 40% of an oil which yields itself in a viscous yellow form upon heating and crushing of the fruit. The raw oil, which chemically consists of the glycerides of oleic, oleo-margaric, and probably isomeric acids, is distinguished by its rapid drying properties. When spread in a thin layer it produces a hard film with an opaque frosted surface, often showing a tendency to wrinkle. Treated tung oil will dry to a clear, water-shedding, elastic film. This oil is made by heating the raw tung oil at a comparatively low temperature with other oils and a metallic drier such as litharge. [Illustration: _Photographs courtesy of David Fairchild_ Aleurites Cordata (Chinese Wood Oil) Barrel Factory at Cooperage Shop] [Illustration: _Photographs courtesy of David Fairchild_ Aleurites Fordii (Chinese Wood Oil) Fruit from trees at the end of fourth year] The affinity of tung oil for rosin has resulted in the production of a series of moderate-priced varnishes most suitable for use in floor and deck paints or wherever great hardness is required. These varnishes are also finding application in the manufacture of concrete, steel, and flat wall paints; being especially suitable for the above purposes when compounded with kauri gum japan. [Illustration: Aleurites Fordii Flowering specimen of the Chinese Wood Oil tree, thirty feet high and three feet in diameter, on banks of Yangtse River, Western Szechuan, China. Opium Poppy in the foreground] [Illustration: Aleurites Cordata Wood Oil tree at Riverside, California, planted in 1907. Photograph taken in 1910, when tree had borne fifty fruits] During the boiling of raw tung oil the temperature must not exceed much over 400 degrees Fahrenheit. Otherwise a peculiar "hamming" will take place, the whole mass becoming solid and of no further value as a varnish or paint vehicle. Some peculiar internal disturbance or rearrangement of the molecules is evidently effected by heat, and although the reaction is not clearly understood, it has been ascribed to auto-polymerization. Scott has stated that the phenomenon of gelatinization is due to the exposure of the surface of the oil to the air, and that boiling in vacuo obviates such results. The lusterless surface produced when tung oil varnishes are dried in vitiated air would tend to confirm the conclusion that the oil is very subject to atmospheric influences. Lumbang Oil, which is obtained from a tropical species of Tung, is very similar in appearance and properties to Linseed Oil. CONSTANTS OF TUNG OILS =====+=========+============+==============+========== | Sp. Gr. | Iodine No. |Saponification| Acid No. | | | No. | -----+---------+------------+--------------+---------- No. 1| .944 | 166 | 188 | 3.6 No. 2| .940 | 164 | 184 | 1.8 =====+=========+============+==============+========== [Illustration: _Photographs courtesy Alpin I. Dunn_ Menhaden Net drying in the Sun] [Illustration: Transporting Menhaden from net to deck of boat, in swinging basket] [Illustration: A big catch of Menhaden made off Narragansett Bay] =Menhaden Oil.= Of all the marine-animal oils, such as seal, herring, sardine, whale, and menhaden, the latter is the most valuable. It is produced by steam digestion and pressure of the menhaden or "piogey" fish, which are caught in great quantities off the Atlantic Coast. Prompt cooking and treatment of the fish results in a light-colored oil having very little odor, the residue left in the presses being of great value as a fertilizer. Although several grades of oil termed crude, brown, light, etc., are produced, the most satisfactory for use in paint is that grade termed "light winter pressed." This oil is of a pale straw color and has a high iodine number which is responsible for its rapid drying value. It contains less of the stearates that precipitate from crude oil, but sufficient to render its film water-shedding and elastic. The presence of too great a quantity of stearates is apt to result in a very soft film, and the use of hard driers, such as the metallic tungates, is therefore advisable with menhaden oil. When mixed with linseed oil paints the odor of menhaden oil is sometimes noticeable, but it disappears entirely after such paints are applied. Its use with linseed oil in technical paints exposed to the salty air of the Coast has given good results, often preventing "checking" and "chalking." The following constants were determined on samples of menhaden oil received in the writer's laboratory: ========+==========+==========+==============+========== | Sp. Gr. | Iodine |Saponification| Acid | | Value | Number | Number --------+----------+----------+--------------+---------- Light | .927 | 175.8 | 187.9 | 7.55 Medium | .925 | 178.7 | 187.6 | 6.19 Dark | .927 | 178.0 | 187.3 | 7.19 ========+==========+==========+==============+========== =Whale Oil.= While ordinary whale oil is too dark and odorous to ever come into extensive use as a paint oil, it is probable that the refined oil will be utilized in the manufacture of certain technical paints. Whale oil is boiled from chopped whale blubber, the first trying being the lightest in color, while the later tryings, as well as the product made from bones, are of darker color and of very bad odor. Oil of mirbane is often used to mask this odor. The oil contains large quantities of stearin and palmitin, as well as wax-like constituents which are apt to be thrown out of solution in very cold weather, or when the oil is mixed with other oils. The refined oil, when ground with lead and zinc pigments and mixed with equal parts of linseed oil and treated tung oil, dries to an elastic and soft film. Experiments are being made to utilize whale oil in the linoleum industry. The analyses of samples of whale oil tested by the writer are as follows: =============+=========+========+==============+============ | Sp. Gr. | Iodine |Saponification| Free Fatty | | Value | Number | Acid -------------+---------+--------+--------------+------------ Light Refined| .924 | 148 | 190.2 | 1.2 Dark Yellow | .920 | 142 | 187 | 7.0 Dark Brown | .910 | 140 | 184 | 18.0 =============+=========+========+==============+============ =Sunflower Oil.= Sunflower oil is produced largely in Russia and Hungary, finding favor in those countries as an edible oil. The ripe seeds of the sunflower plant contain over 30% of oil which is very pale in color and of a pleasant smell. It has been found that sunflowers may be grown to advantage in dry parts of the United States, and if suitable yields are obtained from a few experimental acres now being cultivated, the industry may receive encouragement in this country. The oil should be well suited for varnish making, and although the iodine number is not very high, it dries quite rapidly. [Illustration: Russian Sunflower Seeds] CONSTANTS OF SUNFLOWER OIL ========+============+================+====== Sp. Gr. | Iodine No. | Saponification | Acid | | No. | No. --------+------------+----------------+------ .929 | 128 | 188 | 4 ========+============+================+====== =Cottonseed Oil.= This oil is expressed from the seed of the cotton plant, varying in color according to the time of its pressing and degree of refinement. Being edible as well as highly suited for soap making, very little of it comes into the market as a paint oil. It contains large quantities of stearin and has a low iodine value, making it a slow drying oil. Some samples are extremely light in color and contain less mucilaginous matter and foots than is present in ordinary varieties. CONSTANTS OF COTTONSEED OIL ========+============+================+====== Sp. Gr. | Iodine No. | Saponification | Acid | | No. | No. --------+------------+----------------+------ .922 | 106 | 190 | 2.4 ========+============+================+====== =Corn Oil.= As a by-product in the manufacture of starch and alcoholic liquids, this material comes into the market having a golden yellow color, and an odor resembling fermented grain. It has a lower drying value than cottonseed oil, and its use in the paint industry will probably be limited to color grinding, where an oil with a semi-drying value is often desired. Like cottonseed oil, it belongs more properly to the soap oil class. It contains glycerides of linoleic and especially palmitic acid. ANALYSIS OF CORN OIL ========+============+================+===== Sp. Gr. | Iodine No. | Saponification | Acid | | No. | No. --------+------------+----------------+----- .925 | 118 | 191 | 9.5 ========+============+================+===== =Rosin Oil.= By the dry distillation of rosin, there is yielded a series of heavy dark oils consisting principally of hydrocarbons, resinous bodies, and free acid. These oils vary in their saponification number from 10 to 60, while their unsaponifiable value averages about 80. Of the grades termed first, second, third, and fourth run, the latter two are superior for use in paints, as a rule containing less free acid than the preliminary runs. Treatment with steam and alkali serve to neutralize the acid nature of the oils and to remove impurities. Refined oils are lighter in color and are often blown and bodied to fairly rapid drying products, especially when treated with manganese driers. Rosin oils are seldom used with lead pigments, on account of the presence of sulphur in the oils, which would result in darkening. Rosin oil paints work very smoothly, even when they are curdled, producing glossy surfaces. The rapid checking of rosin oil paints on wooden surfaces bars the use of this oil for such purposes. ANALYSES OF ROSIN OILS ==+=========+============+================+====== | Sp. Gr. | Iodine | Saponification | Acid | | Value | No. | No. --+---------+------------+----------------+------ A | .966 | 41 | 27 | 16.7 B | .99 | 48 | 38 | 10.0 ==+=========+============+================+====== =Hydrocarbon Oils.= Several grades of neutral or mineral oils, varying somewhat in gravity, color, and quality, are produced as the last distillate in the refining of petroleum. These oils when mixed with drying oils and strong driers find application in the manufacture of some freight-car, barn, and other paints which sell at a low price. A small percentage of mineral oil is said to be valuable in structural steel paints, acting as a preventative of hard drying and thus keeping the film soft and elastic. Streaking and sweating is apt to ensue if any great quantity is used. Mineral oils have a characteristic bloom, showing a greenish fluorescence when examined by transmitted light. This bloom is due to the presence of some strongly fluorescent material which is shown up with intensity when mineral oils are exposed to ultraviolet rays such as emanate from an enclosed arc light. Outerbridge[1] first proposed this test for mineral oils, and he has worked out a "fluorescent scale," by which very small percentages of hydrocarbon oils may be detected in other oils. Several types of so-called debloomed oil have been placed upon the market, and although such oils appear under ordinary light conditions to be free from bloom, they fluoresce quite strongly when given the Outerbridge test. [1] Alexander E. Outerbridge, Jr.: "A Novel Method of Detecting Mineral Oil and Resin Oil in Other Oils." Proc. 14th Annual Meet., Amer. Soc. for Testing Mater., Atlantic City, N.J., June 28, 1911. [Illustration: View of Stills Where Petroleum Paint Thinners are Manufactured (Waverly)] ANALYSIS OF DEBLOOMED MINERAL PAINT OIL[2] ========+============+================+===== Sp. Gr. | Iodine No. | Saponification | Acid | | No. | No. --------+------------+----------------+----- .92 | 12 | 4 | 0 ========+============+================+===== [2] Oil of mirbane present, probably as a deblooming agent, or to mask the odor. =Pine Oil.= This oil is produced by the redistillation of the heavy, high boiling point fractions resulting from the steam distillation of wood turpentine. It is a heavy straw-colored oil, and should be of some use in the paint and varnish industry, where a high boiling point solvent with an oxidizing principle is desired. It will probably find application in the manufacture of Baking Japans, Asphalt Paints and Enamels. Its oxidizing and solvent values are very high. It has a distinctive sweet pine smell, which makes it popular in the manufacture of turpentine substitutes from petroleum spirits. The writer has examined samples of this material, and the following appear to be of the best grade: CONSTANTS OF PINE OILS ==========================+======================+==================== | No. 1 | No. 2 --------------------------+----------------------+-------------------- Color |Straw Color |Light Yellow Specific Gravity at 15° C.|.934 |.936 Boiling Point |192° C. |202° C. Distillation |95% distils between |95% distils between | 192-270° C. | 202-280° C. Residue on Evaporation |14.34% |14.60% Polymerization Test |3-2/3% unpolymerized |2-1/2% unpolymerized | at end of 1/2 hour | at end of 1/2 hour Flash-Point |72° C. |76° C. Spot Test |Leaves no grease spot |Same as Pine Oil No. |but only evaporates |1. |completely in 24 hours| ==========================+======================+==================== =Turpentine.= By direct fire or steam distillation of the sap drippings collected in pockets cut into pine trees, there is obtained the turpentine of commerce. It consists largely of pinene and isomeric terpenes, and has the property of attracting oxygen, with the formation of peroxides which stimulate the drying of oils. It is a high-grade solvent for various gums, and is therefore used in the manufacture of many lacquers as well as for thinning down oil-gum varnishes. REQUISITE CONSTANTS OF PURE GUM TURPENTINE Color Water White Specific Gravity at 15° C. .862-.875 Boiling Point About 156° C. Distillation 95% should distil between 153 and 165° C. Residue on Evaporation Not over 2% Polymerization Not over 5% should remain unpolymerized at end of half hour Flash-Point Over 40.5° C. Spot Test No grease spot should remain when dropped on paper and allowed to evaporate Water None =Wood Turpentine.= High-grade wood turpentine is now produced by the steam distillation of finely cut fat pine wood. The lower-grade qualities are often produced from the destructive distillation of sawdust, stumpage, etc., and these products, on account of their content of formaldehyde, are objectionable in odor. In the steam distillation process, however, a high quality product is obtained by cutting out the heavy fractions and redistilling the lower and purer fractions. It has a high oxidizing value, causing the rapid drying of paints and varnishes to which it has been added. Its solvent value is often greater than that of gum turpentine. When properly refined it has a sweet smell and is to be highly recommended. Analyses of samples of pure wood turpentine which have come to the writer for examination follow: ======================+==========================+==================== | No. 1 | No. 2 ----------------------+--------------------------+-------------------- Sp. Gr. at 15° C. |.862 |.862 Boiling Point |158° C. |162° C. Distillation: 95% | | distils between |158 and 185° C. |162 and 177° C. Residue on Evaporation|1.03% |3.06% Polymerization Test |4.1% remains unpolymerized|0.1 cc. out of 6 cc. |at end of 1/2 | unpolymerized = |hour | 1.66% Spot Test |No grease spot on |No grease spot on | evaporation | evaporation Odor |Excellent |Not objectionable Color |Water White |Water White Flash Point | |47.6° C. ======================+==========================+==================== =Petroleum Spirits.= There are produced from Texas crude oil which has an asphaltum base, and Pennsylvania crude oil which has a paraffin base, high boiling-point petroleum spirits which have come into wide use as paint and varnish thinners. When such materials have the proper evaporating value, high flash-point and freedom from sulphur, they are to be highly recommended as paint thinners. The following shows the analyses of a few of these materials examined in the writer's laboratory: PETROLEUM SPIRITS =======================+=============+============+============== | Texas Base | California | Penna. Base | | Base | -----------------------+-------------+------------+-------------- Color | Water White | White | Water White Specific Gravity | .811 | .79 | .81 Boiling Point | 156° C. | 138° C. | 146° C. Flash-Point | 44° C. | 40.5° C. | 43° C. Residue on Evaporation | .2 | .15 | .12 =======================+=============+============+============== =Benzol.= "Solvent naphtha" or 160-degree benzol is a product obtained from the distillation of coal tar, differing from benzine, a product obtained from the distillation of petroleum. It is a valuable thinner to use in the reduction of paints for the priming of resinous lumber and refractory woods such as cypress and yellow pitch pine. The penetrating and solvent values of benzol are high, and it often furnishes a unison between paint and wood, that is a prime foundation to subsequent coatings, preventing the usual scaling and sap exudations which often appear on a painted surface. Because of the great solvent action of benzol, it should never be used in second and third coatings. The writer has successfully painted inferior grades of cypress with a paint containing benzol in the priming coat. =Benzine.= Benzine is seldom used in paints on account of its rapid evaporation, which is apt to cause pinholing of films and other surface defects. In paints of the dipping type where rapid evaporation is essential, benzine finds its widest application. CHAPTER II A STUDY OF DRIERS AND THEIR EFFECT The proper drying of oils and their behavior with various siccatives in varying quantity is an interesting problem, and obviously of considerable importance from a practical standpoint. Unfortunately there is a decided scarcity of reliable literature dealing with the subject for the guidance of those concerned in the manufacture or application of siccative products. Furthermore, when the problem is investigated, it is not difficult to see why this is so. =Uniform Conditions.= At a glance it is evident that a decided obstacle in experimentation on the drying properties of oils is the difficulty in obtaining identical conditions for comparative purposes. Inasmuch as a multitude of factors, such as uniformity and homogeneity of the driers and the oils themselves, intensity and source of light, temperature, uniformity of application, and many others, play a decisive part in the siccative tendencies of oils, the resources and ingenuity of the chemist engaged in the research are severely taxed. =Oxygen Absorption.= It is a well-known fact that linseed oil, when applied to a clean surface, such as a glass plate, will undergo oxidation and take up oxygen to the extent of about 16%, forming a hard, elastic, non-sticky product which has been called linoxyn. This material, unlike the oil from which it has been formed, is insoluble in most solvents. Other oils, such as cottonseed, hemp, rape, olive, etc., are more fully satisfied in nature and have not the power to absorb the amount of oxygen taken up by linseed oil. In carrying out the following tests, on the drying of oils, a quantity of pure linseed oil of the following analysis was secured: Specific gravity at 15° C. 0.934 Acid number 5 Saponification number 191-1/2 Iodine number 188 This oil was distributed into a number of 8-oz. oil sample bottles, and to a series of these bottles was added varying quantities of a very concentrated drier made by boiling oil to 400 degrees Fahrenheit in an open kettle, with the subsequent addition of lead oxide. The amount of drier added to each bottle varied according to the percentage desired; being calculated on the lead content of the drier, which was very accurately determined by analysis. There was secured in this manner a series of oils containing varying amounts of lead oxide, and from this lot was selected a certain number of samples which would be representative and typical of paint vehicles now found in the market. Another series of tests were made by combining with a large number of samples of pure linseed oil as used above, various percentages of a manganese drier made by boiling oil at 400° F. and incorporating therewith manganese dioxide. Still another series of tests were made upon a number of oils into which were incorporated various small quantities of lead oxide and manganese oxide together, using the standard driers made in the above manner, all of which were carefully analyzed to determine their contents. In view of the errors in manipulation that could occur where so many tests were made, it was not deemed advisable, in carrying out the tests, to use glass plates on which only a minute quantity of oil could be maintained. A much better solution of the difficulty presented itself in using a series of small, round, crimped-edge tin plates, about three inches in diameter, such as are used for lids of friction-top cans. With paints it is impossible to secure films as thin as those presented by layers of oil on glass, nor would it be desirable to secure films of this same relative thickness. For this reason an endeavor was made to conduct the following tests with films of the same relative thickness as that possessed by the average coating of paint. The drying of the films did not take place in the same short period, nor in the same ratio, as with the thin layer that is secured by flowing oil upon glass. The results, however, are more practical, and of greater value to the manufacturer. The cans were carefully numbered in consecutive order, corresponding to the numbers on the various samples of oil. A very small quantity of oil was placed in each of the can covers, which were previously weighed, and allowed to distribute itself over the bottom surface thereof. Reweighing of the covers gave the amount of oil which was taken for each test. The test samples in the covers were all placed in a large box with glass sides, having a series of perforated shelves. In the side of this box is an opening through which a tube was passed, carrying a continual current of air washed and dried in sulphuric acid. Oxidation of the oil films commenced at once, and the amount of oxygen absorbed was determined at suitable periods by weighing, the increase in weight giving this factor. This test was kept up for a period of twenty days. A test was also made in the same manner with a current of damp air passing into the box, to observe the relative oxidation under such conditions. A chart of the results obtained has been made (Table VI), to show the effect of the various driers. =Results of Tests.= The following outline will present to the mind of the reader the most salient points which have been gleaned from these experiments, and which should give the manufacturer definite knowledge as to the best percentage of oxides to use either in boiled oil, paints or varnishes. In the case of lead oxide, an increase in the percentage of lead oxide in the oil causes a relative increase in the oxygen absorption, but when a very large percentage of lead has been added, the film of oil dries to a leathery skin. In the case of manganese oxide, the increase in oxygen absorption on the first day is much more pronounced than is the case with lead oxides. Furthermore, the oxidation of manganese oils seems to be relative to the increase in manganese up to a certain period, when the reverse of this law seems to take place, and beyond a certain definite percentage of manganese, added percentages seem to be of no value. It was furthermore observed that the films dry to a more brittle and harder skin than is the case when lead oxide is used. The oxygen absorption with oils high in manganese has been noticed to be excessive, and the film of oil becomes surface-coated, drying beneath in a very slow manner; a condition that often leads to checking. The critical percentage where the amount of manganese appears to give the greatest efficiency seems to be 0.02%. This critical percentage, as it may be termed, should not be exceeded, and any added amount of manganese has the effect of making the film much more brittle and causes the so-called "burning up" of the paint. The loading of paint with drier and the bad result therefrom may be explained to some extent from the above results. TABLE VI--LINSEED OIL AND MnO_{2} (MANGANESE) DRIER--TEST NO. 1 =========+=========+====+====+====+====+====+====+====+====+==== Per cent.| |0.02|0.05|0.15|0.25|0.35|0.45|0.55|0.70|1.00 MnO_{2} | | | | | | | | | | ---------+---------+----+----+----+----+----+----+----+----+---- |{ 1 day |0.08|0.11|0.16| -- |3.21|3.46|3.27|3.01|2.76 |{ 2 days|0.16|5.88|4.48| -- |3.63|4.01|3.70|3.51|3.18 |{ 3 days|0.21|6.79|4.61| -- |3.83|4.31| -- |3.91| -- |{ 4 days| -- | -- |4.64| -- | -- | -- | -- | -- | -- |{ 5 days|3.01|6.84| -- | -- |4.13|4.68|4.19|3.91|3.99 |{ 6 days|8.00| -- |4.88| -- |4.37| -- |4.51|4.32|4.13 Per |{ 7 days|8.58|6.92|4.90| -- |4.48| -- |4.61|4.52|4.23 cent. |{ 8 days|9.06| -- |5.03| -- |4.55|5.23|4.77|4.62|4.44 gain |{ 9 days| -- | -- |5.12| -- |4.63|5.40|4.94|4.79|4.51 |{ 10 days|9.07|6.89|5.18| -- |4.81|5.47| -- |4.98|4.73 |{ 11 days|9.15|7.03| -- | -- | -- | -- | -- | -- | -- |{ 12 days| -- | -- | -- | -- |4.98| -- |5.45|5.33|5.22 |{ 13 days|9.22|7.17| -- | -- |5.25|6.00|5.60|5.42|5.33 |{ 14 days|9.25|7.18|5.55| -- | -- | -- | -- | -- | -- |{ 20 days| -- |7.21|5.81| -- |5.84|6.70|5.94|5.84|5.77 =========+=========+====+====+====+====+====+====+====+====+==== TABLE VII--LINSEED OIL AND MnO_{2} (MANGANESE) DRIER--TEST NO. 2 (CHECK) =========+=========+====+====+====+====+====+====+====+====+==== Per cent.| |0.02|0.05|0.15|0.25|0.35|0.45|0.55|0.70|1.00 MnO_{2} | | | | | | | | | | ---------+---------+----+----+----+----+----+----+----+----+---- |{ 1 day | -- |3.12|4.42|3.86| -- |3.19|2.98|3.27|2.56 |{ 2 days| -- |6.15|4.73| -- | -- |3.51|3.28|3.70|2.96 |{ 3 days|0.28|6.29| -- |4.12|3.72| -- |3.39|3.71|3.15 |{ 4 days|3.83|6.32|4.75|4.21|3.87|3.61|3.58|4.05|3.43 Per |{ 5 days|6.64| -- |4.84|4.23|3.94|3.73|3.65|4.21|3.56 cent. |{ 6 days|8.61| -- |4.87| -- |4.08|3.81|3.78|4.35|3.73 gain |{ 7 days|9.07|6.35|5.00|4.41|4.18|3.91|3.85|4.54|3.87 |{ 9 days|9.25|6.39|5.16| -- |4.44|4.11|4.21|4.63|4.26 |{ 11 days| -- | -- | -- |4.63|4.59|4.36|4.31|5.07|4.46 |{ 16 days| -- |6.43|5.30|4.91|4.83|4.72|4.71|5.40|4.87 =========+=========+====+====+====+====+====+====+====+====+==== TABLE VIII--LINSEED OIL AND PbO (LEAD) DRIER =====+=====+=====+=====+=====+=====+======+======+=====+======+=====+====+==== Per | | | | | | | | | | | | cent.| | 0.00| 0.05| 0.10| 0.30| 0.50 | 0.70 | 1.00| 1.30 | 1.60|1.30|1.60 PbO | | | | | | | | | | | | -----+-----+-----+-----+-----+-----+------+------+-----+------+-----+----+---- |{ 1 |0.042|0.049|0.092|0.058| 0.066| 0.062|0.062| 0.079|0.039|0.14|0.72 |{day | | | | | | | | | | | |{ 2 |0.098|0.104|0.153|0.116| 0.158| -- |0.194| 4.83 |4.79 |5.27|6.11 |{days| | | | | | | | | | | |{ 3 |0.128|0.159|0.170|0.137| 0.279| 0.185|7.11 | 8.60 |5.35 |7.89|8.28 |{days| | | | | | | | | | | |{ 4 |0.164|0.214|0.206|0.178| -- | 4.07 |7.39 | 9.55 |8.53 |7.93|8.68 |{days| | | | | | | | | | | |{ 5 |0.176| -- |0.306| -- | 0.340| 7.60 |7.47 | 9.87 |8.78 |8.18| -- |{days| | | | | | | | | | | Per |{ 6 |0.188|0.231| -- |0.243| 0.472| 9.36 |7.64 |10.01 |9.00 |8.24|9.09 cent.|{days| | | | | | | | | | | gain |{ 7 |0.206|0.251| -- |0.253| 1.080|10.06 | -- |10.14 | -- | -- | -- |{days| | | | | | | | | | | |{ 8 |0.212|0.253| -- |0.280| 4.80 |10.38 |7.70 |10.22 |9.05 | -- | -- |{days| | | | | | | | | | | |{ 9 |0.226|0.291|0.306|0.331| 7.36 |10.41 |7.73 |10.23 |9.07 | -- | -- |{days| | | | | | | | | | | |{13 |0.327|0.428|0.510|0.674|11.01 |10.67 |7.91 |10.48 |9.29 |8.62| -- |{days| | | | | | | | | | | |{15 |0.466|0.455|0.650|2.41 |11.05 | -- |7.92 |10.50 |9.30 | -- | -- |{days| | | | | | | | | | | |{20 |0.521|1.08 |1.78 |8.76 |11.25 |10.67 |7.98 |10.52 |9.36 | -- | -- |{days| | | | | | | | | | | =====+=====+=====+=====+=====+=====+======+======+=====+======+=====+====+==== TABLE IX--LINSEED OIL AND PbO (LEAD) AND MnO_{2} (MANGANESE)--COMBINATION DRIER =================+========+=====+=====+======+======+====+=====+==== Per cent. PbO | | 0.1 | 0.3 | 0.5 | 0.7 |0.9 | 1.1 |1.4 -----------------+--------+-----+-----+------+------+----+-----+---- Per cent. MnO_{2}| |.005 |.015 | 0.025| 0.35 |0.45| 0.55|0.7 -----------------+--------+-----+-----+------+------+----+-----+---- |{ 1 day |0.026|0.061| 0.055| 0.022|0.16| 0.11|3.06 |{ 2 days|0.094|0.087| 0.143| 0.16 |5.21| 6.28|3.37 |{ 3 days|0.118| -- | 0.17 | 4.23 |7.63| 8.31|3.74 |{ 4 days| -- |0.11 | 0.23 | 7.36 |8.87| 9.20|4.02 |{ 5 days|0.120|0.12 | 0.29 | 9.04 |9.13| 9.37|4.17 Per cent. gain |{ 6 days|0.17 |0.13 | 1.44 | 9.88 |9.26| 9.51|4.34 |{ 7 days|0.21 |0.18 | 4.65 |10.11 |9.28| -- |4.45 |{11 days|0.30 |0.26 |10.03 |10.35 |9.61| 9.85|5.11 |{12 days| -- | -- | -- |10.45 |9.66| -- | -- |{13 days|0.35 |0.54 |10.37 |10.51 |9.67|10.03|5.33 |{18 days|0.49 |3.43 |10.38 |10.62 |9.68| -- |5.73 =================+========+=====+=====+======+======+====+=====+==== In the same way with lead driers, excessive amounts of lead oxide seem to have no beneficial effects on the drying of an oil, and when the percentage which seems to be the most beneficial, namely 0.5% lead oxide, is exceeded, the film is apt to become brittle. Oils containing lead oxide driers are less influenced in their drying tendencies by conditions of moisture in the atmosphere than oils containing manganese, but frequently, however, the former dry much better in a dry atmosphere. As a general rule, varnishes rich in manganese dry more quickly in a dry atmosphere, while those containing small quantities dry more quickly in a damp atmosphere. =Volatile Products Formed.= It was furthermore noticed in these tests that sulphuric acid, placed in dishes on the bottom of the large box in which the samples of oil were drying, was discolored and turned brown after several days, showing that the acid had taken up some material of a volatile nature that was a product of the oxidation. Another curious feature of these tests was the development of a peculiar aromatic odor which was given off by the oils upon drying in dry air. When the oils were dried in moist air, a rank odor resembling propionic acid was observed, and this led the observer to believe that a reaction was effected by the absorbed oxygen, that caused the glycerin combined with the linoleic acid as linolein to split up into evil-smelling compounds. It has been suggested that the oxygen first attacks the glycerin, transforming it into carbonic acid, water, and other volatile compounds, which are eliminated before the oil is dried to linoxyn. Toch,[3] however, has shown that the drying of linseed oil gives off only very small percentages of carbon dioxide. Mulder has observed that in the process of linseed oil being oxidized, glycerin is set free, which becomes oxidized to formic, acetic, and other acids, while the acid radicals are converted by oxygen into the anhydrides, from which they pass by further oxidation into linoxyn. [3] Toch: The Chem. and Tech. of Mixed Paints, p. 89. D. Van Vostand Co., N. Y. =Auto-Oxidation of Oil.= The theory of auto-oxidation of linseed oil has been very ably treated by Blackler, whose experiments indicated that during the drying process the slow absorption of oxygen was, at a critical period, followed by a rapid absorption, which he attributes to the presence of peroxides. The materials produced by this peroxide formation may act as catalyzers and accelerate the formation of more peroxide. Lead and manganese oxides may also be oxidized to peroxides by the action of oxygen, and in this event might act as very active catalyzing agents or carriers of oxygen. Blackler's statement, that the presence of driers do not increase, but have a tendency to decrease the initial velocity of oxygen absorption, has been confirmed by these experiments, but it has been noticed throughout the tests that the driers have an accelerative action at a later period. =Effect of Metals on Drying of Oils.= Some most interesting results were secured by dipping extremely fine copper gauze into linseed oil, and then suspending the gauze in the air. The adhesion of the oil to the copper caused the formation of films between the network, and remarkable drying action was observed. The copper or any superficial coating of copper oxide which may have been present on the metal, undoubtedly affected the result to some extent. It has been found that metallic lead is even more efficient than copper in this respect, but this may be due to the action of free acid in the linseed oil, forming lead linoleates, products that greatly accelerate drying. Another interesting experiment was made by immersing pieces of gauze cloth in linseed oil. After the excess oil had been removed, by pressing, the cloth was again weighed to determine the amount of oil used for the experiment. The increase in oxygen absorption in this case was very rapid, and the result obtained confirmed the results in the other experiments. In order to secure a more evenly distributed state of the oil, tests were conducted by saturating pieces of stiff blotting papers, and, after exposure, weighing as usual. =Influence of Light.= The influence of light on the drying of oils is unquestionably a potent one. The practical painter knows that a certain varnish will dry quicker when exposed to the light than when in the dark. Chevreul was one of the first pioneers in this field of research to observe the effects of colored lights on drying, and he claimed that oil exposed under white glass dried more rapidly than when exposed under red glass, which eliminates all light of short wave lengths. Genthe obtained interesting results in the drying of oil submitted to the effect of the mercury lamp. Oxidation without driers was effected probably through the formation of peroxides. In commenting on this subject, Blackler[4] gives a description of the use of the Uveol Lamp, which is similar to the mercury lamp, but has, instead of a glass casing which cuts off the valuable rays, a fused-quartz casing which allows their passage. [4] M. B. Blackler: "The Use and Abuse of Driers," P. and V. Society, London, Sept. 9, 1909. =Driers in Boiled Oil.= In the boiling of linseed oil, by certain processes the oil is heated to 250° F. and manganese resinate is incorporated therein. It goes into solution quite rapidly. In other processes the oil is heated to 400° F. or over, and manganese as an oxide is boiled into the oil. Although it is unsafe to say that a small percentage of rosin, such as would be introduced by the use of resinate driers, is not harmful, yet it appears that this process should give a good oil, inasmuch as it has been found that no matter whether the manganese is added to the oil, as a resinate, borate or oxide, practically the same drying effect is noticed in every case where the percentage of manganese is the same. It is the opinion of some, however, that the resinate driers are not as well suited for durability as oxide driers. However, if a boiled oil is found to contain on analysis a small percentage of rosin less than 0.5% or a percentage only sufficient to combine with the metal present, it should not be suspected of adulteration. Practical tests should be made with such oil along with an oil made with an oxide drier, before pronouncing on their relative values. Inasmuch as the addition of certain driers to linseed oil lessens the durability of the film, it is more practical to use the smallest amount of drier that will serve the purpose desired, that is, set the oil up to a hard condition which will not take dust and which will stand abrasion. The results of this investigation would indicate that when lead or manganese linoleates are used, the most efficient drying is shown with 0.5% lead or with 0.02% manganese, or with a combination of 0.5% lead and 0.02% manganese. Until more definite results have been obtained with the _tungates_, which will probably prove of exceptional interest as driers, the above driers will probably be used to the greatest extent. =Co-operative Drying Tests.= A series of important drying tests made by members of a special committee[5] appointed by the American Society for Testing Materials, of which the writer was chairman, is herewith shown: [5] Sub-Committee C of Committee D-1, on Testing Paint Vehicles. Proc. Amer. Soc. for Test. Mater., 1911. "At the January meeting of Committee D-1, a sub-committee consisting of the following members was appointed to investigate paint vehicles: G. B. Heckel, Glenn H. Pickard, Allen Rogers, A. H. Sabin, H. A. Gardner, _Chairman_. "At a subsequent meeting of the sub-committee it was determined to start the investigations with a series of tests on certain drying, semi-drying, and non-drying oils, determining their drying values, rate of oxygen absorption, etc., when spread out in thin films. A quantity of the following oils was selected for the tests and subsequently secured from sources known to be reliable: Lead and manganese linoleate drier.[6] Lithographic linseed oil. Boiled linseed oil (resinate type). Boiled linseed oil (linoleate type). Blown linseed oil (containing drier while being blown). Heavy mineral oil. Rosin oil. Soya bean oil. Corn oil. Cottonseed oil. Sunflower oil. Menhaden oil. Chinese wood oil, raw. Chinese wood oil, treated. Perilla oil.[7] Lumbang oil.[7] Dry rosin 20%, boiled in 80% linseed oil. [6] The drier used, upon analysis, showed the presence of 4.36% PbO and 2.51% MnO_{2}. [7] The lumbang and perilla oils were imported and arrived subsequent to the starting of the tests. They were therefore not included in the tests. "Four-ounce sample bottles of each oil were sent to the Committee members, with the request to proceed with the tests along the lines agreed upon at the Committee meeting. The instructions for making these tests are outlined as follows: (_a_) A series of small glass plates, approximately 5 by 7 ins., are to be prepared by each member of the Committee. These plates are to be thoroughly cleaned and carefully numbered and weighed upon a chemical balance. The oils to be used for the tests are to be numbered corresponding to the plates. A test of each oil is to be made by painting it upon the surface of a glass plate with a camel's-hair brush, subsequently weighing the plate and the oil. These tests are to be exposed under constant conditions of temperature, if possible, for three weeks' time, making weighings of each plate every day for six days and then every other day for twelve days. (_b_) Another series of tests shall be made, in which 80% of raw linseed oil is to be combined with each of the above oils named. Previous to making any of the tests, _there should be added to each oil, or to each combination, 5% of a drier containing lead and manganese_. The drier to be used is of the standard grade submitted, together with the oil samples. The results of the tests are to be charted and submitted at the end of the tests, so that they may be compared with the results obtained by each member of the Committee. (_c_) If possible, the oils and mixture of oils used in the above tests are to be ground with pure silica and painted out upon sized paper, three-coat work, the films to be stripped and tested for strength upon a paint filmometer, at two periods two months apart." The drying of oils to a firm surface when spread in a thin layer is accompanied by an increase in weight, due to the absorption of oxygen. The percentage of oxygen absorbed often affords a criterion of the drying of the oil under examination, and this factor, together with data regarding the appearance of the oil film, should be taken into consideration when judging the value of an oil or oil mixture. Conditions of light, air, temperature, etc., often cause great variations in the drying of oils and the percentage of oxygen absorbed, as shown by the results obtained in the following tests. Although it was impossible in these tests to have the conditions under which each experimenter worked parallel in nature, the tests afford nevertheless considerable information for guiding future work of a similar nature. An examination of the results obtained showed generally that the greatest increase in weight occurred during the period in which the oil dried up to a firm film. This occurred in most cases within 48 hours. After this period a slight increase in weight was often noticed, and then a more or less steady decline, varying with the oil examined. Had the oil tests been continued for a greater length of time, a much greater loss might have been observed. It was impossible to include in the tests the oil-silica film work, on account of lack of time. It is believed, however, that these tests should be conducted, as they would throw much light on the elasticity and strength given to paint films by various oils. TABLE I.--(_a_) BOILED LINSEED OIL (RESINATE TYPE) 100 PER CENT. ----------------+------------+-----------+-----------+-------------- Observer. | Gardner | Sabin | Pickard | { Rogers } | | | | { North } ----------------+------------+-----------+-----------+-------------- Wt. of Oil for | 0.1997 | 0.6242 | 0.5027 | 0.6024 Test, grams | | | | -----------+----+------------+-----------+-----------+-------------- | 1 | 11.9 | 14.42 | 10.21 | 13.69 | 2 | 12.5 | 13.37 | 10.00 | 13.01 | 3 | 12.7 | 12.53 | 9.57 | 12.50 | 4 | 13.1 | 11.7 | 9.65 | 12.29 | 5 | 12.8 | 11.03 | 8.99 | 12.00 | 6 | 12.7 | -- | -- | 12.25 | 7 | -- | 10.17 | 8.57 | -- | 8 | 12.7 | 10.34 | -- | 11.64 | 9 | -- | 10.12 | 8.93 | -- Percentage | 10 | 12.6 | 10.00 | -- | 10.73 Increase | 11 | -- | -- | 8.81 | -- in Weight, | 12 | 12.8 | 9.69 | -- | 10.68 in Days. | 13 | -- | -- | 9.31 | -- | 14 | 12.8 | -- | -- | 11.18 | 15 | -- | 9.04 | 9.43 | -- | 16 | 12.7 | -- | -- | 10.68 | 17 | -- | 8.68 | -- | -- | 18 | 12.9 | -- | 9.11 | -- | 19 | -- | 8.13 | -- | -- -----------+----+------------+-----------+-----------+-------------- Remarks. |Dried to | | |Tacky at end |firm, smooth| | |of 1st day. |film in 2 | | |Nearly dry, |days | | |end of 2d day. | | | |Perfectly dry, | | | |end of 10th | | | |day. ----------------+------------+-----------+-----------+-------------- (_b_) BOILED LINSEED OIL (RESINATE TYPE) 20 PER CENT. RAW LINSEED OIL 80 PER CENT. ----------------+------------+-----------+-----------+-------------- Observer. | Gardner | Sabin | Pickard | { Rogers } | | | | { North } ----------------+------------+-----------+-----------+-------------- Wt. of Oil for | 0.1933 | 0.3660 | 0.4640 | -- Test, grams | | | | -----------+----+------------+-----------+-----------+-------------- | 1 | 13.6 | 0.57 | 12.48 | -- | 2 | 14.7 | 1.66 | 11.92 | -- | 3 | 14.9 | 10.50 | 11.49 | -- | 4 | 14.9 | 13.30 | 11.10 | -- | 5 | 14.8 | -- | 10.84 | -- | 6 | 14.8 | -- | -- | -- | 7 | -- | 12.51 | 9.48 | -- | 8 | 14.8 | -- | -- | -- | 9 | -- | 11.40 | 7.41 | -- Percentage | 10 | 14.8 | -- | -- | -- Increase | 11 | -- | -- | 7.56 | -- in Weight, | 12 | 14.7 | 10.20 | -- | -- in Days. | 13 | -- | -- | 8.36 | -- | 14 | 14.5 | -- | -- | -- | 15 | -- | 9.84 | 8.54 | -- | 16 | 14.7 | -- | -- | -- | 17 | -- | -- | -- | -- | 18 | 14.7 | -- | 8.51 | -- | 19 | -- | -- | -- | -- -----------+----+------------+-----------+-----------+-------------- Remarks. |Dried to | | | |firm, smooth| | | |film in 2 | | | |days. | | | ----------------+------------+-----------+-----------+-------------- TABLE II.--(_a_) BOILED LINSEED OIL (LINOLEATE TYPE) 100 PER CENT. ----------------+------------+-----------+-----------+--------------- Observer. | Gardner | Sabin | Pickard | { Rogers } | | | | { North } ----------------+------------+-----------+-----------+--------------- Wt. of Oil for | 0.1226 | 0.5384 | 0.5696 | 0.3306 Test, grams | | | | -----------+----+------------+-----------+-----------+-------------- | 1 | 10.9 | 14.34 | 10.25 | 12.09 | 2 | 12.2 | 13.26 | 10.41 | 11.33 | 3 | 12.7 | 12.18 | 10.22 | 10.94 | 4 | 12.5 | 11.29 | 10.16 | 11.10 | 5 | 12.8 | 10.75 | 9.90 | 10.86 | 6 | 12.2 | -- | -- | 11.25 | 7 | -- | 9.88 | 9.60 | -- | 8 | 12.2 | 10.25 | -- | 10.87 | 9 | -- | 10.01 | 9.72 | -- Percentage | 10 | 12.4 | 9.91 | -- | 9.72 Increase | 11 | -- | -- | 9.48 | -- in Weight, | 12 | 12.1 | 9.60 | -- | 10.02 in Days. | 13 | -- | -- | 9.97 | -- | 14 | 12. | -- | -- | 10.62 | 15 | -- | 9.12 | 10.36 | -- | 16 | 12.1 | -- | -- | 10.46 | 17 | -- | 8.37 | -- | -- | 18 | 12.1 | -- | 9.59 | -- | 19 | -- | 8.30 | -- | -- -----------+----+------------+-----------+-----------+-------------- Remarks. |Dried firmly| | |Tacky at end |with smooth,| | |of 1st day. |even film in| | |Slightly |2 days. | | |tacky, end 2d | | | |day. Dry, but | | | |curled, end of | | | |10th day. ----------------+------------+-----------+-----------+-------------- (_b_) BOILED LINSEED OIL (LINOLEATE TYPE) 20 PER CENT. RAW LINSEED OIL 80 PER CENT. ----------------+------------+-----------+-----------+-------------- Observer. | Gardner | Sabin | Pickard | { Rogers } | | | | { North } ----------------+------------+-----------+-----------+-------------- Wt. of Oil for | 0.1843 | 0.5790 | 0.4653 | -- Test, grams | | | | -----------+----+------------+-----------+-----------+-------------- | 1 | 11.8 | 10.14 | 12.40 | -- | 2 | 13.9 | 15.71 | 11.90 | -- | 3 | 15.1 | 13.29 | 11.50 | -- | 4 | 15.2 | 12.12 | 11.11 | -- | 5 | 15.0 | 11.43 | 10.90 | -- | 6 | 14.6 | -- | -- | -- | 7 | -- | 10.05 | 9.37 | -- | 8 | 14.6 | 10.26 | -- | -- | 9 | -- | 9.55 | 8.53 | -- Percentage | 10 | 14.5 | 9.32 | -- | -- Increase | 11 | -- | -- | 7.48 | -- in Weight, | 12 | 14.4 | 8.84 | -- | -- in Days. | 13 | -- | -- | 8.43 | -- | 14 | 14.4 | -- | -- | -- | 15 | -- | 8.46 | 8.02 | -- | 16 | 14.6 | -- | -- | -- | 17 | -- | 7.68 | -- | -- | 18 | 14.7 | -- | 7.27 | -- | 19 | -- | 7.55 | -- | -- -----------+----+------------+-----------+-----------+-------------- Remarks. |Dried with | | | |smooth film | | | |in 2 days. | | | ----------------+------------+-----------+-----------+-------------- TABLE III.--(_a_) LITHOGRAPHIC LINSEED OIL 100 PER CENT. ----------------+------------+-----------+-----------+--------------- Observer. | Gardner | Sabin | Pickard | { Rogers } | | | | { North } ----------------+------------+-----------+-----------+-------------- Wt. of Oil for | 0.4011 | 0.8733 | 0.8812 | 2.7318 Test, grams | | | | -----------+----+------------+-----------+-----------+------------- | 1 | 6.9 | 0.87 | 3.60 | .051 | 2 | 8.5 | 3.85 | 5.10 | .051 | 3 | 8.9 | 5.14 | 5.00 | .051 | 4 | 8.9 | 6.07 | 6.78 | .041 | 5 | 8.7 | 6.40 | 6.97 | .081 | 6 | 8.0 | -- | -- | .169 | 7 | -- | 6.84 | 7.38 | -- | 8 | 8.0 | 7.22 | -- | .19 | 9 | -- | 7.36 | 7.42 | -- Percentage | 10 | 8.0 | 7.57 | -- | .752 Increase | 11 | -- | -- | 7.44 | -- in Weight, | 12 | 8.0 | 7.75 | -- | 1.184 in Days. | 13 | -- | -- | 8.01 | -- | 14 | 8.4 | -- | -- | 1.641 | 15 | -- | 7.98 | 8.03 | -- | 16 | 8.4 | -- | -- | 2.00 | 17 | -- | 7.83 | -- | -- | 18 | 8.3 | -- | 7.99 | -- | 19 | -- | 7.80 | -- | -- -----------+----+------------+-----------+-----------+-------------- Remarks. |Dried to | | |Remained |glossy, firm| | |sticky to 10 |film, | | |days, and even |slightly | | |at end of 38 |crinkled in | | |days was |2 days. Oil | | |slightly |made very | | |tacky. |thick film | | | |on account | | | |of heavy | | | |body. | | | ----------------+------------+-----------+-----------+-------------- (_b_) LITHOGRAPHIC LINSEED OIL 20 PER CENT. RAW LINSEED OIL 80 PER CENT. ----------------+------------+-----------+----------- Observer. | Gardner | Sabin | Pickard | | | ----------------+------------+-----------+----------- Wt. of Oil for | 0.1300 | 0.7750 | 0.6538 Test, grams | | | -----------+----+------------+-----------+----------- | 1 | 10.2 | 11.35 | 9.94 | 2 | 11.3 | 11.48 | 10.41 | 3 | 11.9 | 10.93 | 10.39 | 4 | 12.0 | 10.77 | 10.35 | 5 | 11.8 | 10.25 | 9.93 | 6 | 11.8 | -- | -- | 7 | -- | 9.51 | 9.54 | 8 | 11.8 | 9.93 | -- | 9 | -- | 9.80 | 9.36 Percentage | 10 | 11.8 | 9.68 | -- Increase | 11 | -- | -- | 8.99 in Weight, | 12 | 11.8 | 9.65 | -- in Days. | 13 | -- | -- | 9.61 | 14 | 11.8 | -- | -- | 15 | -- | 9.51 | 9.70 | 16 | 11.9 | -- | -- | 17 | -- | 9.07 | -- | 18 | 11.9 | -- | 9.13 | 19 | -- | 8.67 | -- -----------+----+------------+-----------+----------- Remarks. |Dried to | | |firm, glossy| | |film in 2 | | |days. | | ----------------+------------+-----------+----------- TABLE IV.--(_A_) BLOWN LINSEED OIL 100 PER CENT. ----------------+------------+-----------+-----------+-------------- Observer. | Gardner | Sabin | Pickard | { Rogers } | | | | { North } ----------------+------------+-----------+-----------+-------------- Wt. of Oil for | 0.2105 | 0.8394 | 0.8457 | 1.0398 Test, grams | | | | -----------+----+------------+-----------+-----------+-------------- | 1 | 8.5 | 9.30 | 5.07 | 4.41 | 2 | 10.2 | 8.97 | 6.16 | 4.91 | 3 | 10.2 | 5.30 | 6.48 | 5.22 | 4 | 10.2 | 9.30 | 6.94 | 5.62 | 5 | 10.0 | 8.99 | 6.73 | 5.73 | 6 | 9.9 | -- | -- | 6.06 | 7 | -- | 8.49 | 6.99 | -- | 8 | 9.8 | 8.89 | -- | 6.43 | 9 | -- | 8.73 | 6.89 | -- Percentage | 10 | 9.8 | 8.89 | -- | 6.18 Increase | 11 | -- | -- | 7.11 | -- in Weight, | 12 | 9.7 | 8.73 | -- | 6.51 in Days. | 13 | -- | -- | 7.60 | -- | 14 | 9.8 | -- | -- | 6.95 | 15 | -- | 8.52 | 7.95 | -- | 16 | 9.8 | -- | -- | 7.00 | 17 | -- | 8.07 | -- | -- | 18 | 9.9 | -- | 7.86 | -- | 19 | -- | 7.74 | -- | -- -----------+----+------------+-----------+-----------+-------------- Remarks. |Ropiness of | | |Formed skin, |oil made | | |end 1st day. |very thick | | |Slightly |film, but | | |tacky end 2nd; |dried in | | |dry, but |less than 2 | | |curled, end of |days to | | |10th day. |smooth film.| | | |Films | | | |exhibited | | | |ridges. | | | ----------------+------------+-----------+-----------+-------------- (_b_)BLOWN LINSEED OIL 20 PER CENT. RAW LINSEED OIL 80 PER CENT. ----------------+------------+-----------+----------- Observer. | Gardner | Sabin | Pickard | | | ----------------+------------+-----------+----------- Wt. of Oil for | 0.0774 | 0.5329 | 0.6218 Test, grams | | | -----------+----+------------+-----------+----------- | 1 | 10.4 | 11.82 | 10.71 | 2 | 12.8 | 12.76 | -- | 3 | 13.1 | 10.98 | -- | 4 | 12.9 | 10.39 | -- | 5 | 12.1 | 9.81 | -- | 6 | 11.9 | -- | -- | 7 | -- | 8.69 | -- | 8 | 12.0 | 9.15 | -- | 9 | -- | 8.91 | -- Percentage | 10 | 11.8 | 8.97 | -- Increase | 11 | -- | -- | -- in Weight, | 12 | 11.8 | 8.67 | -- in Days. | 13 | -- | -- | -- | 14 | 11.7 | -- | -- | 15 | -- | 8.22 | -- | 16 | 11.6 | -- | -- | 17 | -- | 7.63 | -- | 18 | 11.8 | -- | -- | 19 | -- | 7.32 | -- -----------+----+------------+-----------+----------- Remarks. |Dried to | |Glass broke. |very glossy | | |film in 2 | | |days. | | ----------------+------------+-----------+----------- TABLE V.--(_a_) MINERAL OIL 100 PER CENT. ----------------+------------+-----------+-----------+-------------- Observer. | Gardner | Sabin | Pickard | { Rogers } | | | | { North } ----------------+------------+-----------+-----------+-------------- Wt. of Oil for | 0.1632 | -- | -- | 0.1975 Test, grams | | | | -----------+----+------------+-----------+-----------+-------------- | 1 | [8]12.5 | -- | -- | [8] 8.12 | 2 | [8]14.2 | -- | -- | [8]16.22 | 3 | [8]16.7 | -- | -- | [8]21.23 | 4 | [8]19.4 | -- | -- | [8]25.58 | 5 | [8]19.4 | -- | -- | [8]28.41 | 6 | [8]19.5 | -- | -- | [8]28.92 | 7 | -- | -- | -- | -- | 8 | [8]19.5 | -- | -- | [8]35.25 | 9 | -- | -- | -- | -- Percentage | 10 | [8]19.5 | -- | -- | [8]35.76 Increase | 11 | -- | -- | -- | -- in Weight, | 12 | [8]19.3 | -- | -- | [8]43.86 in Days. | 13 | -- | -- | -- | -- | 14 | [8]19.4 | -- | -- | [8]45.28 | 15 | -- | -- | -- | -- | 16 | [8]19.5 | -- | -- | [8]48.08 | 17 | -- | -- | -- | -- | 18 | [8]19.5 | -- | -- | -- | 19 | -- | -- | -- | -- -----------+----+------------+-----------+-----------+-------------- Remarks. |Oil lost in |Broken be- |Broken be- |Remained oily |weight |fore weigh-|fore weigh-|during entire |throughout |ings were |ings were |test. |test on ac- |made. |made. | |count of | | | |presence of | | | |volatiles. | | | |No drying | | | |action ob- | | | |served. Film| | | |wet at end | | | |of test. | | | ----------------+------------+-----------+-----------+-------------- [8] Lost in weight throughout test. (_b_) MINERAL OIL 20 PER CENT. RAW LINSEED OIL 80 PER CENT. ----------------+------------+-----------+-----------+-------------- Observer. | Gardner | Sabin | Pickard | { Rogers } | | | | { North } ----------------+------------+-----------+-----------+-------------- Wt. of Oil for | 0.1884 | 0.5663 | 0.405 | 0.2598 Test, grams | | | | -----------+----+------------+-----------+-----------+-------------- | 1 | 6.4 | 11.51 | [9]9.66 | [9]6.69 | 2 | 6.8 | 8.21 | [9]8.92 | [9]5.06 | 3 | 7.2 | 6.51 | [9]6.82 | [9]2.88 | 4 | 7.8 | 5.19 | [9]6.03 | [9]1.52 | 5 | 8.1 | 4.36 | [9]4.68 | [9]1.29 | 6 | 7.9 | -- | -- | [9]1.68 | 7 | -- | 2.72 | [9]2.64 | -- | 8 | 7.9 | 3.12 | -- |[10]2.07 | 9 | -- | 2.82 |[10]0.30 | -- Percentage | 10 | 8.1 | 2.59 | -- |[10]0.08 Increase | 11 | -- | -- |[10]0.56 | -- in Weight, | 12 | 7.8 | 2.35 | -- |[10]0.93 in Days. | 13 | -- | -- |[10]0.04 | -- | 14 | 7.8 | -- | -- |[10]0.54 | 15 | -- | 1.36 |[10]0.14 | -- | 16 | 7.8 | -- | -- | -- | 17 | -- | 0.53 | -- | -- | 18 | 7.8 | -- |[10]0.86 | -- | 19 | -- |[10]0.14 | -- | -- -----------+----+------------+-----------+-----------+-------------- Remarks. |Fair drying | | |Sticky, end of |observed end| | |1st day; |of 2d day. | | |tacky, end of |Film tacky | | |2d day and end |until end | | |of 38 days. |8th day; | | | |after that, | | | |fairly firm | | | |film shown. | | | ----------------+------------+-----------+-----------+-------------- [9] Gained in weight throughout test. [10] Lost in weight throughout test. TABLE VI.--(_a_) SOYA BEAN OIL 100 PER CENT. ----------------+------------+-----------+-----------+-------------- Observer. | Gardner | Sabin | Pickard | { Rogers } | | | | { North } ----------------+------------+-----------+-----------+-------------- Wt. of Oil for | 0.1377 | 0.3972 | 0.4366 | 0.3564 Test, grams | | | | -----------+----+------------+-----------+-----------+-------------- | 1 | 7.5 | 9.79 | 9.87 | 8.25 | 2 | 8.4 | 9.69 | 9.87 | 7.58 | 3 | 9.5 | 8.56 | 9.35 | 7.02 | 4 | 12.8 | 7.60 | 8.66 | 6.74 | 5 | 12.9 | 7.09 | 8.13 | 6.46 | 6 | 12.7 | -- | -- | 6.74 | 7 | -- | 6.00 | 6.44 | -- | 8 | 12.6 | 6.22 | -- | 6.46 | 9 | -- | 6.00 | 4.88 | -- Percentage | 10 | 12.5 | 5.54 | -- | 5.40 Increase | 11 | -- | -- | 4.26 | -- in Weight, | 12 | 12.4 | 5.36 | -- | 5.59 in Days. | 13 | -- | -- | 4.99 | -- | 14 | 12.3 | -- | -- | 5.80 | 15 | -- | 4.73 | 4.94 | -- | 16 | 12.3 | -- | -- | 5.67 | 17 | -- | 4.23 | -- | -- | 18 | 12.3 | -- | 4.94 | -- | 19 | -- | 3.70 | -- | -- -----------+----+------------+-----------+-----------+-------------- Remarks. |Film tacky | | |Sticky, end of |until 3d | | |1st day; |day. Clear | | |tacky, end of |and fairly | | |2d day; |firm after | | |slightly |4th day. | | |tacky, end of | | | |10th and 38th | | | |days. ----------------+------------+-----------+-----------+-------------- (_b_) SOYA BEAN OIL 20 PER CENT. RAW LINSEED OIL 80 PER CENT. ----------------+------------+-----------+-----------+-------------- Observer. | Gardner | Sabin | Pickard | { Rogers } | | | | { North } ----------------+------------+-----------+-----------+-------------- Wt. of Oil for | 0.2218 | 0.2877 | 0.4581 | 0.2249 Test, grams | | | | -----------+----+------------+-----------+-----------+-------------- | 1 | 11.5 | 12.78 | 13.16 | 11.74 | 2 | 11.8 | 12.78 | 12.64 | 12.27 | 3 | 12.5 | 11.74 | 11.84 | 10.38 | 4 | 13.9 | 12.23 | 11.50 | 9.43 | 5 | 14.0 | 10.60 | 11.01 | 9.66 | 6 | 14.0 | -- | -- | 9.75 | 7 | -- | 9.35 | 9.15 | -- | 8 | 14.1 | 10.08 | -- | 10.29 | 9 | -- | 9.76 | 7.29 | -- Percentage | 10 | 14.1 | 9.59 | -- | 9.08 Increase | 11 | -- | -- | 6.61 | -- in Weight, | 12 | 13.8 | 9.59 | -- | 8.18 in Days. | 13 | -- | -- | 7.43 | -- | 14 | 13.6 | -- | -- | 8.95 | 15 | -- | 9.00 | 6.96 | -- | 16 | 13.6 | -- | -- | -- | 17 | -- | 8.09 | -- | -- | 18 | 13.6 | -- | 6.66 | -- | 19 | -- | 8.00 | -- | -- -----------+----+------------+-----------+-----------+-------------- Remarks. |Clear, firm | | |Tacky at end |film ob- | | |of 1st and 2d |served at | | |days. Dry, end |end of 2d | | |10th day. |day. | | | ----------------+------------+-----------+-----------+-------------- TABLE VII.--(_a_) ROSIN OIL 100 PER CENT. ----------------+------------+-----------+-----------+-------------- Observer. | Gardner | Sabin | Pickard | { Rogers } | | | | { North } ----------------+------------+-----------+-----------+-------------- Wt. of Oil for | 0.2590 | -- | -- | 0.4822 Test, grams | | | | -----------+----+------------+-----------+-----------+-------------- | 1 | 1.5 | -- | -- | 2.24 | 2 | 1.5 | -- | -- | 2.53 | 3 | 1.8 | -- | -- | 2.32 | 4 | 3.0 | -- | -- | 1.27 | 5 | 5.2 | -- | -- | 1.06 | 6 | 4.9 | -- | -- | 0.66 | 7 | -- | -- | -- | -- | 8 | 4.8 | -- | -- | 0.24 | 9 | -- | -- | -- | -- Percentage | 10 | 4.8 | -- | -- | 0.78 Increase | 11 | -- | -- | -- | -- in Weight, | 12 | 4.8 | -- | -- | 0.68 in Days. | 13 | -- | -- | -- | -- | 14 | 4.8 | -- | -- | 0.41 | 15 | -- | -- | -- | -- | 16 | 4.8 | -- | -- | 0.39 | 17 | -- | -- | -- | -- | 18 | 4.8 | -- | -- | -- | 19 | -- | -- | -- | -- -----------+----+------------+-----------+-----------+-------------- Remarks. |Tacky | |Too much |Oily on 1st |throughout | |on. Showed |and 2d days. |test. | |constantly |Tacky, end of | | |increasing |10 and 38 | | |loss owing |days. | | |to the fact| | | | that it | | | |did not dry| | | |and ran off| | | |glass. | ----------------+------------+-----------+-----------+-------------- TABLE VII.--(_b_) ROSIN OIL 20 PER CENT. RAW LINSEED OIL 80 PER CENT. ----------------+------------+-----------+-----------+-------------- Observer. | Gardner | Sabin | Pickard | { Rogers } | | | | { North } ----------------+------------+-----------+-----------+-------------- Wt. of Oil for | 0.1636 | 0.7105 | 0.4016 | 0.3263 Test, grams | | | | -----------+----+------------+-----------+-----------+-------------- | 1 | 7.4 | 6.64 | 12.21 | 11.48 | 2 | 7.8 | 6.40 | 11.45 | 12.02 | 3 | 8.5 | 6.05 | 11.13 | 10.60 | 4 | 8.5 | 5.63 | 10.53 | 10.26 | 5 | 8.4 | 5.23 | 10.13 | 10.42 | 6 | 8.1 | -- | -- | 10.42 | 7 | -- | 4.42 | 8.8 | -- | 8 | 8.0 | 4.92 | -- | 10.95 | 9 | -- | 4.83 | 8.12 | -- Percentage | 10 | 8.0 | 4.57 | -- | 9.96 Increase | 11 | -- | -- | 7.45 | -- in Weight, | 12 | 8.0 | 4.68 | -- | 9.53 in Days. | 13 | -- | -- | 8.27 | -- | 14 | 7.9 | -- | -- | 9.96 | 15 | -- | 4.13 | 8.52 | -- | 16 | 7.9 | -- | -- | -- | 17 | -- | 3.81 | -- | -- | 18 | 8.2 | -- | 8.62 | -- | 19 | -- | 3.43 | -- | -- -----------+----+------------+-----------+-----------+-------------- Remarks. |Film dried | | |Oily at end of |up nicely | | |1st and 2d |during 3d | | |days. Slightly |day, but re-| | |tacky, end of |mained | | |10th day. |slightly | | | |soft. | | | ----------------+------------+-----------+-----------+-------------- TABLE VIII.--(_a_) CORN OIL 100 PER CENT. ----------------+------------+-----------+-----------+-------------- Observer. | Gardner | Sabin | Pickard | { Rogers } | | | | { North } ----------------+------------+-----------+-----------+-------------- Wt. of Oil for | 0.0574 | 0.5858 | 0.4981 | 0.3300 Test, grams | | | | -----------+----+------------+-----------+-----------+-------------- | 1 | 1.9 |[11]0.22 | 1.22 | 4.63 | 2 | 4.2 | 7.03 | 5.86 | 7.27 | 3 | 4.6 | 8.79 | 7.27 | 7.14 | 4 | 4.8 | 7.43 |[12]11.35 | 6.99 | 5 | 7.5 | 7.17 | 11.35 | 6.69 | 6 | 7.1 | -- | -- | 6.93 | 7 | -- | 5.85 | 11.37 | -- | 8 | 7.1 | 6.02 | -- | 6.84 | 9 | -- | 5.84 | 6.26 | -- Percentage | 10 | 7.1 | 5.58 | -- | 5.11 Increase | 11 | -- | -- | 4.97 | -- in Weight, | 12 | 7.2 | 5.38 | -- | 5.17 in Days. | 13 | -- | -- | 5.62 | -- | 14 | 7.1 | -- | -- | 5.38 | 15 | -- | 4.78 | 5.34 | -- | 16 | 7.0 | -- | -- | 5.17 | 17 | -- | 4.15 | -- | -- | 18 | 6.9 | -- | 5.34 | -- | 19 | -- | 3.63 | -- | -- -----------+----+------------+-----------+-----------+-------------- Remarks. |Film soft | | | |and sticky | | | |throughout | | | |test. Very | | | |soapy in | | | |appearance. | | | ----------------+------------+-----------+-----------+-------------- [11] Lost in weight throughout test. [12] Moth got in. (_b_) CORN OIL 20 PER CENT. RAW LINSEED OIL 80 PER CENT. ----------------+------------+-----------+-----------+-------------- Observer. | Gardner | Sabin | Pickard | { Rogers } | | | | { North } ----------------+------------+-----------+-----------+-------------- Wt. of Oil for | 0.1664 | 0.5469 | 0.3716 | 0.1711 Test, grams | | | | -----------+----+------------+-----------+-----------+-------------- | 1 | 7.5 | 13.01 | 13.81 | 11.87 | 2 | 8.4 | 12.41 | 12.92 | 11.69 | 3 | 8.6 | -- | 12.16 | 9.78 | 4 | 10.2 | 11.13 | 11.71 | 8.33 | 5 | 10.4 | 11.52 | 11.11 | 8.50 | 6 | 10.6 | -- | -- | 8.62 | 7 | -- | 11.22 | 9.23 | -- | 8 | 10.5 | 10.98 | -- | 9.61 | 9 | -- | 10.38 | 8.29 | -- Percentage | 10 | 10.3 | 9.64 | -- | 8.16 Increase | 11 | -- | -- | 7.24 | -- in Weight, | 12 | 10.3 | 9.07 | -- | 7.00 in Days. | 13 | -- | -- | 8.42 | -- | 14 | 10.3 | -- | -- | 8.28 | 15 | -- | 8.38 | 8.26 | -- | 16 | 10.2 | -- | -- | -- | 17 | -- | 8.77 | -- | -- | 18 | 10.0 | -- | 7.94 | -- | 19 | -- | -- | -- | -- -----------+----+------------+-----------+-----------+-------------- Remarks. |Film tacky | | |Tacky, end of |at end of | | |1st and 2d |test. | | |days. Dry, end | | | |10th day. ----------------+------------+-----------+-----------+-------------- TABLE IX.--(_a_) COTTON SEED OIL 100 PER CENT. ----------------+------------+-----------+-----------+-------------- Observer. | Gardner | Sabin | Pickard | { Rogers } | | | | { North } ----------------+------------+-----------+-----------+-------------- Wt. of Oil for | 0.2026 | 0.7247 | 0.4135 | 0.3583 Test, grams | | | | -----------+----+------------+-----------+-----------+-------------- | 1 | 4.5 | 8.03 | 7.04 | 6.67 | 2 | 4.8 | 7.48 | 7.16 | 5.61 | 3 | 4.8 | 6.68 | 6.62 | 4.85 | 4 | 5.1 | 6.00 | 6.24 | 4.65 | 5 | 8.6 | 5.65 | 5.78 | 4.37 | 6 | 8.7 | -- | -- | 4.71 | 7 | -- | 4.85 | 3.72 | -- | 8 | 8.1 | 5.09 | -- | 4.57 | 9 | -- | 4.95 | 2.08 | -- Percentage | 10 | 7.9 | 4.80 | -- | 2.97 Increase | 11 | -- | -- | 1.72 | -- in Weight, | 12 | 8.0 | -- | -- | 3.11 in Days. | 13 | -- | -- | 2.52 | -- | 14 | 8.0 | -- | -- | 3.39 | 15 | -- | -- | 2.35 | -- | 16 | 8.1 | -- | -- | 3.39 | 17 | -- | -- | -- | -- | 18 | 8.0 | -- | 2.32 | -- | 19 | -- | -- | -- | -- -----------+----+------------+-----------+-----------+-------------- Remarks. |Film showed | | |Slightly |very little | | |tacky, end |hardening | | |10th and 38th |and remained| | |days. |soft and | | | |tacky. | | | ----------------+------------+-----------+-----------+-------------- (_b_) COTTON SEED OIL 20 PER CENT. RAW LINSEED OIL 80 PER CENT. ----------------+------------+-----------+-----------+-------------- Observer. | Gardner | Sabin | Pickard | { Rogers } | | | | { North } ----------------+------------+-----------+-----------+-------------- Wt. of Oil for | 0.1516 | 0.9498 | 0.6160 | 0.2553 Test, grams | | | | -----------+----+------------+-----------+-----------+-------------- | 1 | 8.5 | 11.00 | 10.94 | 11.83 | 2 | 8.7 | 11.15 | 10.81 | 11.83 | 3 | 9.1 | 10.58 | 10.51 | 10.15 | 4 | 10.8 | 10.17 | 10.37 | 9.29 | 5 | 11.9 | 9.82 | 9.87 | 9.29 | 6 | 11.8 | -- | -- | 9.45 | 7 | -- | 9.02 | 8.93 | -- | 8 | 11.9 | 9.42 | -- | 10.00 | 9 | -- | 9.35 | 8.90 | -- Percentage | 10 | 11.9 | 9.27 | -- | 8.95 Increase | 11 | -- | -- | 8.70 | -- in Weight, | 12 | 11.8 | 9.32 | -- | 8.06 in Days. | 13 | -- | -- | 9.29 | -- | 14 | 11.8 | -- | -- | 8.61 | 15 | -- | 8.81 | 9.63 | -- | 16 | 11.8 | -- | -- | -- | 17 | -- | 8.24 | -- | -- | 18 | 10.7 | -- | 8.47 | -- | 19 | -- | 7.92 | -- | -- -----------+----+------------+-----------+-----------+-------------- Remarks. |Fair drying | | |Tacky on 1st |observed at | | |and 2d days. |end of 4th | | |Dry on 10th |day. Film | | |day. |slightly | | | |tacky at end| | | |of test. | | | ----------------+------------+-----------+-----------+-------------- TABLE X.--(_a_) SUN FLOWER OIL 100 PER CENT. ----------------+------------+-----------+-----------+-------------- Observer. | Gardner | Sabin | Pickard | { Rogers } | | | | { North } ----------------+------------+-----------+-----------+-------------- Wt. of Oil for | 0.1414 | 0.6292 | 0.5837 | 0.2540 Test, grams | | | | -----------+----+------------+-----------+-----------+-------------- | 1 | 6.3 | 9.69 | 7.85 | 8.39 | 2 | 8.2 | 9.42 | 7.73 | 6.94 | 3 | 11.5 | 7.99 | 7.45 | 6.21 | 4 | 11.6 | 7.43 | 7.02 | 6.13 | 5 | 11.5 | 7.04 | 6.36 | 5.81 | 6 | 11.5 | -- | -- | 6.01 | 7 | -- | 6.12 | 5.16 | -- | 8 | 11.3 | 6.45 | -- | 6.09 | 9 | -- | 6.12 | 4.57 | -- Percentage | 10 | 11.3 | 5.92 | -- | 4.81 Increase | 11 | -- | -- | 4.20 | -- in Weight, | 12 | 11.3 | 5.69 | -- | 4.73 in Days. | 13 | -- | -- | 4.54 | -- | 14 | 11.3 | -- | -- | 4.81 | 15 | -- | 5.24 | 4.61 | -- | 16 | 11.2 | -- | -- | 5.01 | 17 | -- | 4.57 | -- | -- | 18 | 11.0 | -- | 4.30 | -- | 19 | -- | 4.26 | -- | -- -----------+----+------------+-----------+-----------+-------------- Remarks. |Film fairly | | |Sticky, end |firm, end of| | |1st day; |3d day. | | |tacky, end 2d | | | |day; slightly | | | |tacky, end | | | |10th day. ----------------+------------+-----------+-----------+-------------- TABLE X.--(_b_) SUN FLOWER OIL 20 PER CENT. RAW LINSEED OIL 80 PER CENT. ----------------+------------+-----------+-----------+-------------- Observer. | Gardner | Sabin | Pickard | { Rogers } | | | | { North } ----------------+------------+-----------+-----------+-------------- Wt. of Oil for | 0.1600 | 0.5030 | 0.4470 | 0.2261 Test, grams | | | | -----------+----+------------+-----------+-----------+-------------- | 1 | 9.5 | 14.21 | 12.62 | 11.54 | 2 | 11.0 | 14.21 | 12.02 | 11.85 | 3 | 11.1 | 12.66 | 11.48 | 9.92 | 4 | 11.3 | 14.01 | 11.65 | 9.13 | 5 | 11.4 | 11.59 | 10.25 | 8.95 | 6 | 10.9 | -- | -- | 9.04 | 7 | -- | 10.24 | 8.14 | -- | 8 | 10.8 | 10.63 | -- | 9.52 | 9 | -- | 10.34 | 6.26 | -- Percentage | 10 | 10.8 | 10.34 | -- | 8.55 Increase | 11 | -- | -- | 5.54 | -- in Weight, | 12 | 10.8 | 10.27 | -- | 7.67 in Days. | 13 | -- | -- | 6.22 | -- | 14 | 10.6 | -- | -- | 8.20 | 15 | -- | 11.33 | 5.82 | -- | 16 | 10.6 | -- | -- | -- | 17 | -- | 10.73 | -- | -- | 18 | 10.9 | -- | 5.35 | -- | 19 | -- | 10.30 | -- | -- -----------+----+------------+-----------+-----------+-------------- Remarks. |Good firm, | | |Dry on 1st, 2d |glossy film | | |and 10th days. |shown at end| | | |of 2d day. | | | ----------------+------------+-----------+-----------+-------------- TABLE XI.--(_a_) MENHADEN OIL 100 PER CENT. ----------------+------------+-----------+-----------+-------------- Observer. | Gardner | Sabin | Pickard | { Rogers } | | | | { North } ----------------+------------+-----------+-----------+-------------- Wt. of Oil for | 0.1944 | 0.5282 | 0.7005 | 0.3150 Test, grams | | | | -----------+----+------------+-----------+-----------+-------------- | 1 | 7.7 | 12.47 | 10.79 | 11.27 | 2 | 8.1 | 12.17 | 10.98 | 10.16 | 3 | 8.9 | 11.70 | 10.85 | 9.72 | 4 | 10.1 | 11.47 | 10.90 | 9.97 | 5 | 9.8 | 11.13 | 10.57 | 9.94 | 6 | 9.8 | -- | -- | 10.27 | 7 | -- | 10.28 | 9.27 | -- | 8 | 9.8 | 11.20 | -- | 10.36 | 9 | -- | 11.15 | 8.48 | -- Percentage | 10 | 9.8 | 11.02 | -- | 8.80 Increase | 11 | -- | -- | 8.27 | -- in Weight, | 12 | 9.8 | 11.37 | -- | 9.22 in Days. | 13 | -- | -- | 8.91 | -- | 14 | 9.6 | -- | -- | 9.40 | 15 | -- | 10.85 | 8.75 | -- | 16 | 9.6 | -- | -- | 9.31 | 17 | -- | 10.34 | -- | -- | 18 | 9.6 | -- | 9.21 | -- | 19 | -- | 9.90 | -- | -- -----------+----+------------+-----------+-----------+-------------- Remarks. |Good drying | | |Sticky, end |during 2d | | |1st day. |day. Fairly | | |Slightly |firm film. | | |sticky, end 2d | | | |and 10th days. ----------------+------------+-----------+-----------+-------------- (_b_) MENHADEN OIL 20 PER CENT. RAW LINSEED OIL 80 PER CENT. ----------------+------------+-----------+-----------+-------------- Observer. | Gardner | Sabin | Pickard | { Rogers } | | | | { North } ----------------+------------+-----------+-----------+-------------- Wt. of Oil for | 0.2448 | 0.4959 | 0.4201 | 0.2456 Test, grams | | | | -----------+----+------------+-----------+-----------+-------------- | 1 | 8.5 | 14.11 | 13.19 | 10.99 | 2 | 10.4 | 13.47 | 12.88 | 11.28 | 3 | 12.2 | 12.68 | 12.23 | 9.56 | 4 | 12.9 | 12.04 | 11.81 | 8.90 | 5 | 12.9 | 11.59 | 11.17 | 8.72 | 6 | 12.9 | -- | -- | 8.72 | 7 | -- | 10.44 | 9.50 | -- | 8 | 12.9 | 11.09 | -- | 9.34 | 9 | -- | 11.04 | 8.48 | -- Percentage | 10 | 12.9 | 10.74 | -- | 8.40 Increase | 11 | -- | -- | 7.77 | -- in Weight, | 12 | 12.9 | 10.90 | -- | 7.37 in Days. | 13 | -- | -- | 8.33 | -- | 14 | 12.8 | -- | -- | 8.11 | 15 | -- | 10.18 | 8.24 | -- | 16 | 12.7 | -- | -- | -- | 17 | -- | 9.48 | -- | -- | 18 | 12.9 | -- | 8.12 | -- | 19 | -- | 8.93 | -- | -- -----------+----+------------+-----------+-----------+-------------- Remarks. |Good firm, | | |Nearly dry on |elastic film| | |1st and 2d |shown after | | |days. |2d day. | | | ----------------+------------+-----------+-----------+-------------- TABLE XII.--(_a_) RAW CHINESE WOOD OIL 100 PER CENT. ----------------+------------+-----------+-----------+-------------- Observer. | Gardner | Sabin | Pickard | { Rogers } | | | | { North } ----------------+------------+-----------+-----------+-------------- Wt. of Oil for | 0.2266 | 0.5545 | 0.4933 | 0.4036 Test, grams | | | | -----------+----+------------+-----------+-----------+-------------- | 1 | 4.1 | -- | 0.59 | 0.54 | 2 | 11.2 | -- | 2.09 | 2.80 | 3 | 14.9 | 11.02 | 5.13 | 5.10 | 4 | 14.4 | 11.53 | 7.56 | 6.00 | 5 | 14.4 | 11.03 | 8.68 | 6.27 | 6 | 14.2 | -- | -- | 7.09 | 7 | -- | 10.53 | 10.11 | -- | 8 | 14.2 | 10.74 | -- | 8.39 | 9 | -- | 10.47 | 9.65 | -- Percentage | 10 | 14.2 | 10.27 | -- | 8.01 Increase | 11 | -- | -- | 9.43 | -- in Weight, | 12 | 14.2 | 10.22 | -- | 8.55 in Days. | 13 | -- | -- | 9.77 | -- | 14 | 14.2 | -- | -- | 9.13 | 15 | -- | 9.80 | 9.73 | -- | 16 | 14.2 | -- | -- | 9.27 | 17 | -- | 9.25 | -- | -- | 18 | 14.5 | -- | 9.33 | -- | 19 | -- | 8.86 | -- | -- -----------+----+------------+-----------+-----------+-------------- Remarks. |Film crys- | | |Sticky, end of |tallized and| | |1st and 2d |remained | | |days; dry but |soft until | | |drawn, end of |3d day. Hard| | |10th day. |but opaque | | | |film shown | | | |after 4th | | | |day. | | | ----------------+------------+-----------+-----------+-------------- (_b_) RAW CHINESE WOOD OIL 20 PER CENT. RAW LINSEED OIL 80 PER CENT. ----------------+------------+-----------+-----------+-------------- Observer. | Gardner | Sabin | Pickard | { Rogers } | | | | { North } ----------------+------------+-----------+-----------+-------------- Wt. of Oil for | 0.2087 | 0.2967 | 0.3683 | 0.2285 Test, grams | | | | -----------+----+------------+-----------+-----------+-------------- | 1 | 9.0 | 14.46 | 14.37 | 11.99 | 2 | 12.1 | 13.11 | 13.66 | 11.90 | 3 | 12.9 | 11.72 | 13.11 | 10.14 | 4 | 12.8 | 10.68 | 12.41 | 9.30 | 5 | 12.8 | 9.77 | 11.78 | 9.08 | 6 | 12.8 | -- | -- | 9.30 | 7 | -- | 8.66 | 10.51 | -- | 8 | 12.7 | 8.86 | -- | 9.70 | 9 | -- | 8.80 | 8.72 | -- Percentage | 10 | 12.6 | 8.49 | -- | 8.90 Increase | 11 | -- | -- | 7.0 | -- in Weight, | 12 | 12.6 | 8.15 | -- | 7.34 in Days. | 13 | -- | -- | 8.82 | -- | 14 | 12.5 | -- | -- | 7.78 | 15 | -- | 8.05 | 8.39 | -- | 16 | 12.5 | -- | -- | -- | 17 | -- | 7.41 | -- | -- | 18 | 12.7 | -- | 7.98 | -- | 19 | -- | 7.04 | -- | -- -----------+----+------------+-----------+-----------+-------------- Remarks. |Clear and | | |Dry at end of |firm film | | |1st day. |shown after | | | |3d day. | | | ----------------+------------+-----------+-----------+-------------- TABLE XIII.--(_a_) CHINESE WOOD OIL (TREATED) 100 PER CENT. ----------------+------------+-----------+-----------+-------------- Observer. | Gardner | Sabin | Pickard | { Rogers } | | | | { North } ----------------+------------+-----------+-----------+-------------- Wt. of Oil for | 0.1678 | 0.4159 | 0.2934 | 0.3937 Test, grams | | | | -----------+----+------------+-----------+-----------+-------------- | 1 |[13]38.0 |[13]19.06 |[13]0.92 | 3.53 | 2 |[13]30.0 |[13]20.16 |[13]0.41 | 3.58 | 3 |[13]28.0 |[13]20.47 | 0.72 | 3.25 | 4 |[13]28.0 |[13]20.47 | 0.79 | 3.25 | 5 |[13]28.0 |[13]20.80 | 0.13 | 3.33 | 6 |[13]28.0 | -- | -- | 2.93 | 7 | -- |[13]21.09 | 0.22 | -- | 8 |[13]28.0 |[13]20.87 | -- | 2.55 | 9 | -- |[13]20.98 | 0.46 | -- Percentage | 10 | 27.5 |[13]20.78 | -- | 3.40 Increase | 11 | -- | -- | 0.44 | -- in Weight, | 12 |[13]26.0 |[13]20.70 | -- | 3.23 in Days. | 13 | -- | -- | 0.43 | -- | 14 |[13]26.0 | -- | -- | 2.61 | 15 | -- |[13]20.97 | 0.42 | -- | 16 |[13]26.0 | -- | -- | 2.48 | 17 | -- |[13]21.22 | -- | -- | 18 |[13]26.2 | -- | 0.43 | -- | 19 | -- |[13]21.11 | -- | -- -----------+----+------------+-----------+-----------+-------------- Remarks. |Loss ob- | | |Dry at end of |served due | | |1st day. |to presence | | | |of vola- | | | |tiles. Firm,| | | |clear film | | | |shown at end| | | |of 1st day. | | | ----------------+------------+-----------+-----------+-------------- [13] Lost in weight throughout test. TABLE XIII.--(_b_) CHINESE WOOD OIL (TREATED) 20 PER CENT. RAW LINSEED OIL 80 PER CENT. ----------------+------------+-----------+-----------+-------------- Observer. | Gardner | Sabin | Pickard | { Rogers } | | | | { North } ----------------+------------+-----------+-----------+-------------- Wt. of Oil for | 0.1638 | 0.6572 | 0.4892 | 0.2644 Test, grams | | | | -----------+----+------------+-----------+-----------+-------------- | 1 | 8.4 | 9.25 | 8.93 | 3.21 | 2 | 9.4 | 8.07 | 8.71 | 3.48 | 3 | 9.8 | 7.36 | 8.44 | 2.15 | 4 | 9.7 | 6.75 | 8.16 | 1.58 | 5 | 9.9 | 6.25 | 7.95 | 1.56 | 6 | 9.9 | -- | -- | 1.77 | 7 | -- | 5.49 | 6.75 | -- | 8 | 10.0 | 5.87 | -- | 2.30 | 9 | -- | 5.70 | 5.99 | -- Percentage | 10 | 9.6 | 5.67 | -- | 1.62 Increase | 11 | -- | -- | 5.50 | -- in Weight, | 12 | 9.5 | 4.37 | -- | 0.86 in Days. | 13 | -- | -- | 6.40 | -- | 14 | 9.5 | -- | -- | 1.50 | 15 | -- | 5.15 | 6.01 | -- | 16 | 9.5 | -- | -- | -- | 17 | -- | 4.69 | -- | -- | 18 | 9.6 | -- | 5.87 | -- | 19 | -- | 4.17 | -- | -- -----------+----+------------+-----------+-----------+-------------- Remarks. |Clear and | | |Dry at end of |hard film | | |1st day. |shown during| | | |2d day. | | | ----------------+------------+-----------+-----------+--------------- TABLE XIV.--(_a_) 20 PER CENT. DRY ROSIN IN 80 PER CENT. LINSEED OIL 100 PER CENT. ----------------+------------+-----------+-----------+-------------- Observer. | Gardner | Sabin | Pickard | { Rogers } | | | | { North } ----------------+------------+-----------+-----------+-------------- Wt. of Oil for | 0.2030 | -- | 0.5185 | 0.2554 Test, grams | | | | -----------+----+------------+-----------+-----------+-------------- | 1 | 12.0 | -- | 3.76 | 1.80 | 2 | 14.1 | -- | 8.76 | 11.78 | 3 | 14.8 | -- | 9.20 | 12.17 | 4 | 14.2 | -- | 9.20 | 12.29 | 5 | 14.5 | -- | 8.49 | 12.02 | 6 | 14.0 | -- | -- | 12.49 | 7 | -- | -- | 9.07 | -- | 8 | 14.1 | -- | -- | 13.15 | 9 | -- | -- | 9.01 | -- Percentage | 10 | 14.1 | -- | -- | 11.85 Increase | 11 | -- | -- | 9.09 | -- in Weight, | 12 | 14.0 | -- | -- | 11.78 in Days. | 13 | -- | -- | 10.50 | -- | 14 | 14.0 | -- | -- | 12.69 | 15 | -- | -- | 10.16 | -- | 16 | 14.0 | -- | -- | 12.83 | 17 | -- | -- | -- | -- | 18 | 14.1 | -- | 10.18 | -- | 19 | -- | -- | -- | -- -----------+----+------------+-----------+-----------+-------------- Remarks. |Rapid drying| | |Oily, end 1st |observed. | | |and 2d days; |Hard film | | |slightly |shown during| | |tacky, end |2d day. | | |10th day. ----------------+------------+-----------+-----------+--------------- (_b_) 20 PER CENT. DRY ROSIN IN 80 PER CENT. LINSEED OIL 20 PER CENT. RAW LINSEED OIL 80 PER CENT. ----------------+------------+-----------+-----------+-------------- Observer. | Gardner | Sabin | Pickard | { Rogers } | | | | { North } ----------------+------------+-----------+-----------+-------------- Wt. of Oil for | 0.1500 | 0.7105 | 0.4568 | -- Test, grams | | | | -----------+----+------------+-----------+-----------+-------------- | 1 | 10.9 | 14.19 | 12.86 | -- | 2 | 13.5 | 13.17 | 12.73 | -- | 3 | 13.6 | 11.84 | 12.13 | -- | 4 | 13.0 | 11.46 | 12.02 | -- | 5 | 13.0 | 10.87 | 11.30 | -- | 6 | 13.0 | -- | -- | -- | 7 | -- | 9.80 | 10.95 | -- | 8 | 13.1 | 10.33 | -- | -- | 9 | -- | 10.40 | 11.21 | -- Percentage | 10 | 13.1 | 10.04 | -- | -- Increase | 11 | -- | -- | 10.53 | -- in Weight, | 12 | 13.0 | 10.35 | -- | -- in Days. | 13 | -- | -- | 11.21 | -- | 14 | 12.9 | -- | -- | -- | 15 | -- | 9.64 | 10.88 | -- | 16 | 13.0 | -- | -- | -- | 17 | -- | 8.98 | -- | -- | 18 | 13.2 | -- | 11.43 | -- | 19 | -- | 8.62 | -- | -- -----------+----+------------+-----------+-----------+-------------- Remarks. |Clear, hard | | | |film after | | | |2d day. | | | ----------------+------------+-----------+-----------+-------------- TABLE XV.--(_a_) RAW LINSEED OIL 100 PER CENT.[14] ----------------+-----------+----------- Observer. | Sabin | Pickard | | ----------------+-----------+----------- Wt. of Oil for | 0.5274 | 0.5326 Test, grams | | -----------+----+-----------+----------- | 1 | 0.26 | 12.42 | 2 | 0.51 | 12.39 | 3 | 0.11 | 11.88 | 4 | 2.35 | 11.83 | 5 | 9.14 | 11.08 | 6 | -- | -- | 7 | 14.48 | 10.29 | 8 | 14.48 | -- | 9 | 14.18 | 9.56 Percentage | 10 | 13.86 | -- Increase | 11 | -- | 9.85 in Weight, | 12 | 13.00 | -- in Days. | 13 | -- | 10.30 | 14 | -- | -- | 15 | 12.23 | 10.12 | 16 | -- | -- | 17 | 11.66 | -- | 18 | -- | 10.78 | 19 | 11.07 | -- -----------+----+-----------+----------- Remarks. | | ----------------+-----------+----------- [14] The test of this oil was made without the addition of 5 per cent. of drier, the quantity used in all the other tests. (_b_) DRIER 100 PER CENT. ----------------+-------------- Observer. | { Rogers } | { North } ----------------+-------------- Wt. of Oil for | 0.3445 Test, grams | -----------+----+-------------- | 1 | 48.95 | 2 | 48.53 | 3 | 48.68 | 4 | 48.68 | 5 | 48.48 | 6 | 48.26 | 7 | -- | 8 | 48.43 | 9 | -- Percentage | 10 | 48.89 Increase | 11 | -- in Weight, | 12 | 48.22 in Days. | 13 | -- | 14 | 48.22 | 15 | -- | 16 | -- | 17 | -- | 18 | -- | 19 | -- -----------+----+-------------- Remarks. | Dry at end of | 1st day. ----------------+-------------- CHAPTER III PAINT PIGMENTS AND THEIR PROPERTIES For the student of paint technology, who is not already acquainted with the chemistry and physics of the various raw pigments which are largely used in the manufacture of paints, the writer advises a careful reading of this chapter, in which the matter has been condensed as much as possible. In order to more thoroughly acquaint the reader with the physical constitution of the pigments under consideration, there has been included photomicrographs, which show to advantage the structure of each.[15] [15] The author gratefully acknowledges the assistance of Dr. J. A. Schaeffer in the preparation of the photomicrographs shown in this chapter. [Illustration: By Polarized Light By Transmitted Light Basic Carbonate-White Lead] =Basic Carbonate-White Lead.= This pigment is made by stacking clay pots containing dilute acetic acid and lead buckles, in tiers, and covering them with tan bark. Fermentation of the tan bark, with subsequent formation of carbon dioxide acting on the acetate of lead formed within the pots, produces basic carbonate of lead. After complete corrosion, the white lead is ground, floated, and dried. Corroded white lead has a specific gravity of 6.8 and contains about 85% lead oxide and 15% of carbon dioxide and water. Its opaque nature and excellent body renders it extremely valuable as a constituent of paints. Checking and chalking progress rapidly when the pigment is used alone. The various sized particles, both large and small, resulting from the corrosion process, are prominently shown in the photomicrograph. [Illustration: Crystals of Cerussite in Old Dutch Process White Lead. (Greatly magnified)] [Illustration: White Lead (Quick Process)] On account of its alkaline nature, this pigment acts upon the saponifiable oil in which it is ground, forming lead soaps which accelerate chalking of white lead--the greatest evil attending its use. Solubility in carbonic acid of the atmosphere and decay in the presence of sodium chloride may be active causes of the rapid chalking of this pigment at the seashore. Checking in some climates appears to proceed rapidly on white lead paints, in a deep hexagonal form, leaving a series of rough crests and cracks. This checking is secondary to the chalking which takes place. [Illustration: Corrosion cylinders used for making Quick Process White Lead] [Illustration: Lead Melting Pots] =White Lead (Quick Process).= By acting on atomized metallic lead, contained within large revolving wooden cylinders, with dilute acetic acid and carbon dioxide, the quick-process white lead is produced. Its value is equal to the Dutch-process white lead, and it is considered by some as possessing greater spreading value. [Illustration: Sheet iron box luted at bottom with water. Atomized lead, blown into box with steam, falls to bottom and becomes hydrated (Mild Process)] [Illustration: _Photographs courtesy of Stowe Neal_ View of agitation tanks for making Mild Process Lead] [Illustration: Steam Jected Pans for Drying White Lead] =White Lead (Mild Process).= The Mild Process of manufacturing white lead consists of first melting the pig lead and converting it into the finest kind of lead powder, then mixing thoroughly with air and water. The lead takes up water and oxygen and forms a basic hydroxide of lead. Carbon dioxide gas is next pumped slowly through the cylinders which contain the basic hydroxide of lead. The result is basic carbonate of lead--the dry white lead of commerce. The process is called "Mild" because it is the mildest process possible for the manufacture of white lead. It is the only method in practical operation which does not require the use of acids, alkalis or other chemicals, every trace of which should be removed from the finished product by expensive purifying processes. The failure of such washing and purifying means a product of inferior quality, which necessarily reduces the durability of any paint in which it is used. =Basic Sulphate-White Lead (Sublimed White Lead).= By the action of the oxygen of the air on the fume produced by the roasting and subsequent volatilization of galena, this fine, white, amorphous pigment is made. On analysis, its composition shows approximately 75% of lead sulphate, 20% of lead oxide, and 5% of zinc oxide. It has a specific gravity of 6.2. Possessed of extreme stability, it finds wide use as a constituent of paints and as a base for tinting colors. The photomicrograph of this pigment shows its extremely fine, amorphous nature with complete absence of crystals. In fineness it closely approaches zinc oxide. On account of its non-poisonous properties it is replacing corroded lead in many places. Unified paints containing sublimed white lead are of great value, showing upon long exposure very little decay. [Illustration: View of Furnace for Making Sublimed White Lead] [Illustration: View of Goosenecks Used for Collecting Sublimed White Lead Fume] [Illustration: Bag Room Where Sublimed White Lead is Deposited _Photographs courtesy of Picher Lead Co._] [Illustration: Sublimed White Lead] [Illustration: View of largest Zinc Oxide Works in America, at Hazards, Pa.] =Sublimed Blue Lead.= Sublimed blue lead is made by burning coarsely broken lumps of galena, admixed with bituminous coal, in a special form of furnace. The fumes which are volatilized from this mixture are very complex in their chemical make-up, and in color are white, blue, and black. After being drawn through the cooling pipes by the suction of huge fans, whereby the fumes are cooled, the pigment is deposited in bags. This pigment is bluish black in color, and has been highly recommended for use on iron and steel. Its composition runs approximately as follows: Lead sulphate 50% Lead oxide 35% Lead sulphide 5% Lead sulphite 5% Zinc oxide 2% Carbon 3% [Illustration: View of Zinc Oxide Furnaces] [Illustration: _Photographs courtesy Geo. B. Heckel and N. J. Zinc Co._ View of Zinc Oxide Fume Pipes with electrically driven Suction Fans] The color of the pigment is largely due to the carbon and the lead sulphide. Its specific gravity is 6.4, and it grinds in 10% of oil to a stiff paste, 100 lbs. of which may be thinned with about 26 lbs. of oil to working consistency. Paint manufacturers use it in mixture with iron oxide and other pigments for the production of paints for metal surfaces. Wood and others have found it of great value for this purpose. It has a tendency to chalk, but this may be overcome by admixture with other pigments such as zinc oxide and iron oxide. Lane has found it to be very durable when admixed with lampblack. [Illustration: View of Bag Room receiving Zinc Oxide] =Zinc Oxide.= This extremely white and fine pigment is prepared by the roasting and sublimation of franklinite, zincite, and other zinc-bearing ores largely found in New Jersey. Its purity approaches in most instances 99.5 or more. It has a specific gravity of 5.2. On account of its stability, whiteness, and opacity, it is invaluable as a pigment when a constituent in a combination formula. Its extreme hardness renders it less resistant to temperature changes, when used alone. Under the microscope the fineness and structure of the particles are clearly evident. The French-process zinc oxide produced in America by the sublimation and oxidation of spelter is the purest made, and superior to imported grades which often contain ultramarine blue as a whitening agent. [Illustration: Zinc Oxide] [Illustration: Zinc Lead White] [Illustration: Zinc Lead. By transmitted light (_The Pigment shows black_)] [Illustration: Lithopone] [Illustration: Magnesium Silicate (Asbestine)] =Zinc Lead White.= This extremely fine pigment, consisting of about equal parts of zinc oxide and lead sulphate, results from the reduction, volatilization and subsequent oxidation of sulphur-bearing lead and zinc ores. It has a specific gravity of 4.4. Its slightly yellowish tint bars it from being used alone very extensively, but when mixed with white lead, zinc oxide and inert pigments, or used as a base for colored paints, it is of considerable value. The magnification of the particles shows the peculiar way in which the pigment agglomerates, and the characteristics of a fine, uniform pigment. [Illustration: Asbestine Mine at Easton, Pa.] [Illustration: American Barytes. Transmitted light (_The Pigment shows black_)] [Illustration: German Barytes. Mag. 250 Diam. (_The Pigment shows white_)] =Lithopone.= Lithopone, probably the whitest of pigments, results from the double decomposition of zinc sulphate and barium sulphide, thereby forming a molecular combination of zinc sulphide and barium sulphate. The peculiar property which it possesses, of darkening under the actinic rays of the sun, makes it essential that it be combined with other, more stable pigments to prolong its life when exposed to weather. Lithopone contains approximately 70% barium sulphate, 25 to 28% zinc sulphide, and as high as 5% of zinc oxide. Its specific gravity is about 4.25. It is excellently suited for interior use in the manufacture of enamels and wall finishes. When properly mixed with other pigments, such as zinc oxide and calcium carbonate, fair results are obtained as a pigment for outside work. Lead pigments are never used with lithopone, as lead sulphide results, giving a black appearance. Its characteristic flocculent, non-crystalline nature is plainly evident when examined under the microscope. [Illustration: By Polarized Light By Transmitted Light Barium Sulphate (Barytes)] =Magnesium Silicate (Asbestine and Talcose).= This pigment comes in two forms: as asbestine and as talcose (talc, etc.). The former is very fibrous in nature and is a very stable pigment to use in the manufacture of paint, on account of its inert nature and tendency to hold up heavier pigments, and prevent settling. It also has the property of strengthening a paint coat in which it is used. The talcose variety is very tabular in form. Both varieties are transparent in oil, and very inert. They have a gravity of about 2.7 and grind in about 32% of oil. [Illustration: Barium Carbonate. Mag. 250 Diam. (_The Pigment shows white_)] [Illustration: Barium Sulphate (Blanc Fixe)] [Illustration: Calcium Carbonate (Whiting)] [Illustration: Calcium Carbonate. By transmitted light (_The Pigment shows black_)] [Illustration: Calcium Sulphate. By transmitted light (_The Pigment shows black_)] [Illustration: Calcium Sulfate] [Illustration: Calcium Sulphate (Gypsum)] [Illustration: Silica (Silex)] [Illustration: Silex. Mag. 250 Diam. (_The Pigment shows white_)] [Illustration: China Clay. By transmitted light (_The Pigment shows black_)] =Barium Sulphate (Barytes).= By grinding the crude ore, treating with acid to remove the iron, and finally washing, floating, and drying, there is produced the commercial form of this valuable pigment. It is used in large quantity as a base upon which to precipitate colors, and also together with other white pigments in the manufacture of ready-mixed paints. It renders the paint coating more resistant to abrasion, and gives to the paint certain very important brushing qualities. It is a very stable pigment, not being materially affected by either acid or alkali, and can be used with the most delicate colors. In oil it is transparent and must be mixed with opaque pigments when used in ready-mixed paints. It is generally used with lighter pigments, such as asbestine, in order to prevent settling. Under the microscope, both by polarized and transmitted light, the sharp angles of the particles appear distinctly, with no tendency to mass into a compact form. Although transparent in oil, it is valuable in moderate percentage in a ready-mixed paint. =Barium Sulphate (Blanc Fixe).= Blanc fixe is the precipitated form of barium sulphate, resulting from the action of soluble barium salts on soluble sulphates. The specific gravity (4.2) of this compound is lower than that of barytes. Possessing greater opacity in oil, it is of more value as a paint pigment for some purposes. It comes in for its greatest use as a base on which to precipitate lake colors. The very fine particles show a slight tendency to agglomerate. =Calcium Carbonate (Whiting).= The natural form of calcium carbonate, prepared from chalk, has a much higher specific gravity (2.74) than that of the artificial form (2.5) prepared by the precipitation of calcium carbonate. The latter, however, possesses greater hiding properties. Both grades find a wide use in distemper work and in the manufacture of putty. It is often used in small percentage in many ready-mixed paints. The photomicrograph of the pigment shows the presence of many large particles. =Calcium Sulphate (Gypsum).= The mineral gypsum, consisting of calcium sulphate and about 21% of water of combination, is sometimes used as a paint pigment after grinding and dehydration. Being slightly soluble in water it has a tendency to pass into solution when exposed to atmospheric agencies. It lacks hiding power in oil. Its specific gravity is 2.3. As in the case of all pigments prepared directly from mineral substances, the many-sized and shaped particles appear clearly when enlarged. Partially and wholly dehydrated forms of gypsum are also used in paint. =Silica (Silex.)= This white pigment possesses great tooth and spreading properties. It is of use as a wood filler and as a constituent in combination paints. It wears especially well when used in combination with zinc oxide and white lead. Its purity often approaches 97%. The particles when enlarged are seen to have sharp angles and are not uniform in size, which accounts for its marked tooth and properties. [Illustration: Aluminum Silicate (China Clay)] [Illustration: Ochre] [Illustration: Raw Burnt Sienna] [Illustration: Raw Burnt Umber] =Aluminum Silicate (China Clay).= China clay, or aluminum silicate, is a permanent and valuable white pigment showing very little hiding power in oil. It is found widely distributed in granitic formations. It is very stable, with a gravity of 2.6. Particles are found in many shapes and sizes, showing sharp and definite angles. =Ochre.= Ochre is a hydrated ferric oxide permeating a clay base, largely used as a tinting material. It has a specific gravity of about 3.5, and a decidedly golden yellow color. A good quality should contain 20% or over of iron oxide. The particles of this pigment are flocculent and very uniform in appearance. =Sienna.= Sienna, like umber, is essentially a silicate of iron and alumina, containing manganic oxide. It contains, however, a lower percentage of the latter than in the case of umbers. The photomicrograph of the burnt variety shows clearly the fine condition of the pigment, while large particles are shown in the raw variety. =Umber.= Umber, another naturally occurring pigment, consists of iron and aluminum silicates, containing varying proportions of manganic oxide, its color and tone varying according to the percentage of the latter. The raw variety is drab in color, which in burning changes to reddish brown. A marked percentage of large-sized particles exist in this pigment. =Indian Red.= Indian red is the term applied to natural hematite ore pigments and to those produced by the roasting of copperas (iron sulphate). They generally contain 95% or more of iron oxide, with varying percentages of silica. The pigment is heavier (specific gravity 5.2) than that of Metallic Brown. The crystalline, mineral-like structure of the particles differ greatly from the amorphous particles of Metallic Brown. =Metallic Brown.= The natural hydrated iron oxide or carbonate as mined largely in Pennsylvania, yields, when roasted, a sesquioxide of iron known as Metallic Brown. It contains a high percentage of alumina and silica, and has a characteristic brown color with a gravity of 3.1. It finds wide application as a pigment for protective purposes. The particles when enlarged show the usual appearance of a natural compound which has been roasted and ground. ==========+=====+===========+==========+=============+=======+========= No. Name |Iron | Calc. | Alumina | Insoluble | Color | |Oxide| Sulph. | | |(Silica| +-----+-----------+(CaSO_{4})|(Al_{2}O_{3})| and | | FeO |Fe_{2}O_{3}| | | Sili- | | | | | | cates)| ----------+-----+-----------+----------+-------------+-------+--------- | % | % | % | % | % | 0 Bright | 0.71| 96.52 | -- | -- | .30 |Bright Red | | | | | |Scarlet 1 Bright | .71| 95.92 | -- | -- | .30 |Scarlet Red | | | | | |Tone 2 Indian | .57| 96.00 | .78 | 1.40 | .90 |Indian Red | | | | | |Red, | | | | | |Medium | | | | | |Shade 3 Indian | 0.29| 97.82 | .85 | -- | .52 |Indian Red | | | | | |Red, | | | | | |Dark | | | | | |Shade 4 Indian | 0.28| 95.72 | 1.21 | 1.26 | .58 |Indian Red | | | | | |Red, | | | | | |Light | | | | | |Shade 5 Persian| 4.53| 62.25 | 1.75 | -- | 27.64 |Rich, Gulf | | | | | |Medium Mix | | | | | |Red 7 Native | 0.85| 89.00 | -- | 0.91 | 6.09 |Medium Red | | | | | |Red, Oxide | | | | | |Brownish | | | | | |Tone 8 Special| 0.57| 43.87 | 50.88 | 2.03 | 1.30 |Scarlet Red | | | | | |Tone 10 Red | 1.44| 60.25 | .78 | 5.41 | 15.78 |Brownish- Oxide | | | | | |Red 11 Vene- | .30| 34.08 | 52.60 | 2.20 | 3.39 |Bright tian | | | | | |Red- Red | | | | | |Brown 12 B. | 0.58| 67.68 | -- | 2.48 | 1.97 |Dark Red Oxide | | | | | |Brown 13 Vene- | 0.29| 25.92 | 58.62 | 2.16 | 1.42 |Medium tian | | | | | |Red Red | | | | | |Tone 14 Vene- | 0.57| 35.36 | .99 | 12.06 | 47.97 |Brown tian | | | | | | Red | | | | | | 15 Metal- | 2.59| 64.00 | .63 | 5.82 | 23.42 |Rich lic | | | | | |Brown Brown | | | | | | 16 Crimson| 0.57| 66.24 | 1.77 | 3.60 | 25.63 |Rich Oxide | | | | | |Dark | | | | | |Red 17 Red | 2.30| 80.39 | .37 | .03 | 9.63 |Medium Oxide | | | | | |Brown 18 Red | 0.57| 61.28 | .97 | 2.68 | 15.94 |Light Oxide | | | | | |Choco- | | | | | |late | | | | | |Brown 20 Red | 7.78| 46.72 | 1.70 | 7.64 | 20.38 |Dark Oxide | | | | | |Reddish | | | | | |Brown 23 Special| 0.58| 72.48 | -- | 8.80 | 4.48 |Deep French | | | | | |Choco- Oxide | | | | | |late | | | | | |Brown 24 Mica- | 2.02| 86.27 | -- | 2.04 | 9.50 |Dark ceous | | | | | |Gray Black | | | | | |Tone Oxide | | | | | | 25 Black |33.12| 57.12 | -- | 1.44 | -- |Jet Oxide | | | | | |Black 26 Red | 0.57| 84.16 | 5.00 | 2.00 | .63 |Deep Oxide | | | | | |Red 27 Special| 0.57| 38.40 | 55.62 | 2.12 | 1.53 |Medium Red | | | | | |Red 28 Oxide C| -- | 30.40 | .94 | 13.60 | 42.30 |Brown ==========+=====+===========+==========+=============+=======+========= =Analysis of Iron Oxide Pigments.= Because of the great consideration now being given to iron oxide paints, the writer secured a series of oxides widely used in this country, and has determined the most important constituents of each. =Basic Lead Chromate (American Vermilion).= By boiling white lead with chromate of soda and subsequently treating with small quantities of sulphuric acid, American vermilion, or basic lead chromate, is prepared. It contains 98% of lead compounds, frequently free chromates, and has a gravity of 6.8. The particles appear granular and large, frequently assuming a square structure. =Red Lead.= By the continued oxidation of litharge in reverberatory furnaces, red lead is produced as a brilliant red pigment with a specific gravity of 8.7. The pigment particles appear to be of many sizes, showing a slight tendency to form a compact mass. =Paranitraniline Red.= Paranitraniline red, a very bright red material largely used in tinting paints, is prepared by diazotizing paranitraniline in hydrochloric acid by means of sodium nitrite in the cold. This compound is rendered insoluble when precipitated directly on barytes, by acting on it with an alkaline solution of beta naphthol. It is the most stable and permanent bright red organic pigment which the paint manufacturer uses. The particles of this pigment appear in various sizes, due, no doubt, to a massing of the particles in the precipitation process. =Chrome Yellow.= The neutral chromate of lead, made from either the nitrate or acetate of lead and chromate of soda, finds wide use as a tinting pigment. When precipitated on a white pigment base, various trade names are given to it. The microscope shows clearly the physical character of this pigment. =Zinc Chromate.= This pigment is made either from zinc salts and bichromate of potash or zinc oxide heated with chrome salts, frequently in the presence of acid. Like the rest of the chromate pigments, it is a very slow-drying material, often requiring over a week to set up, unless considerable drier is added. In spite of the impurities which it carries, it has shown itself to be one of the most inhibitive pigments known and has demonstrated its value in even small percentages in paints for iron and steel. It dries to a hard adherent film that tends to protect metal from corrosion. [Illustration: Indian Red] [Illustration: Metallic Brown] [Illustration: Basic Lead Chromate (American Vermilion)] [Illustration: Red Lead] [Illustration: Paranitraniline] [Illustration: Chrome Yellow] =Prussian Blue.= On oxidizing the precipitate resulting from the interaction of solutions of prussiate of potash and copperas (iron sulphate), Prussian blue as used in the paint trade is prepared. It has a specific gravity of 1.9. The pigment shows an amorphous structure, the particles varying greatly in size. =Ultramarine Blue.= This bright blue pigment is prepared by burning silica, china clay, soda ash and sulphur in pots or furnaces. It has a specific gravity of 2.4. It is of little value as a paint pigment on account of its sulphur content, which causes darkening when mixed with lead pigments, and corrosion when applied to iron or steel. The darkness of the photograph is due to the massing of the pigment particles. =Chrome Green.= Chrome green is prepared as a paint pigment from nitrate of lead, Chinese blue, and bichromate of soda. It has a gravity of 4 and is liable to contain slight traces of lead salts. The particles when magnified appear very fine and flocculent. This color is often precipitated on pigments, such as barytes, which do not reduce its tone. =Bone Black.= By grinding the carbonaceous matter resulting from the charring of bones, in iron retorts, the pigment bone black is prepared. It contains about 15% of carbon and 85% of calcium phosphate. It has a gravity of 2.7. Comparatively large particles of charred bone can be seen scattered throughout the mass, resulting from the difficulty of grinding to a uniform size. =Carbon Black.= This form of very pure carbon results from the combustion of gas. Its gravity, 1.09, is lower than that of lampblack, which shows a gravity of 1.8. It is used in much the same way and for the same purposes as lampblack. In physical appearance it shows great similarity to the particles of lampblack. =Lampblack.= This pigment, made from the combustion of oils, consists very often of more than 99% carbon. It has wonderful tinting value. The particles show a fine, fibrous structure with a tendency toward agglomeration. They differ greatly in physical appearance from those of either graphite or bone black, being exceedingly more uniform than the latter. [Illustration: Zinc Chromate] [Illustration: Prussian Blue] [Illustration: Ultramarine Blue] [Illustration: Chrome Green] [Illustration: Bone Black] [Illustration: Carbon Black] =Graphite.= Graphite, both in the natural and artificial form, contains impurities such as silica, iron oxide and alumina, but the natural form has a much greater percentage of these foreign materials, in some cases as high as 40%. Graphite is usually mixed with other pigments, such as red lead and sublimed blue lead, thus serving better as a paint coating. The difference in physical appearance of the various carbon pigments is interesting, as each pigment has characteristics of its own. In graphite we find a great tendency toward agglomeration or massing of particles. =Mineral Black.= Mineral black is a pigment made by grinding a black form of slate. It contains a comparatively low percentage of carbon and consequently has low tinting value. It finds use as an inert pigment in compounded paints, especially for machine fillers. The pigment has a flocculent appearance, the particles showing a strong tendency to mass. Photomicrographs of two combination paint pigments are here given, to show the various pigments as they appear under the microscope, when in combination. PERCENTAGES OF OIL REQUIRED FOR GRINDING VARIOUS DRY PIGMENTS INTO AVERAGE PASTE FORM White lead (corroded) 9% White lead (sublimed) 10% Zinc lead (American) 12% French process zinc oxide 17% American process zinc oxide 16% Blanc fixe 30% Barytes (natural) 9% Paris white (whiting) 20% Terra alba (gypsum) 22% Floated silica or Silex 26% Kaolin (China clay) 28% Asbestine 32% Blue, ultramarine 27% Blue, Chinese or Prussian 50% Black, gas carbon 82% Black, lamp 72% Black, drop 60% Black, bone 50% Brown, mineral 24% Brown, vandyke 50% Chrome yellow, lemon 23% Chrome yellow, medium 30% Chrome yellow, orange 20% Chrome yellow, dark orange 15% Chrome green, Chem. pure light 21% Chrome green, Chem. pure extra dark 25% Chrome green, 25%, color light 13% Chrome green, 25%, color extra dark 17% Graphite (pure) 40% Indian red, (98%) 20% Ochre, yellow, American 26% Ochre, yellow, French 28% Ochre, golden 28% Red, Venetian 23% Red, Oxide 25% Red, Tuscan 27% Red, Turkey 28% Red, lead 12% Red, lake 55% Sienna, Italian, raw 52% Sienna, Italian, burnt 45% Sienna, American, burnt 38% Sienna, American, raw 40% Ultramarine green 28% Umber, Turkey, raw 48% Umber, Turkey, burnt 47% Umber, American, burnt 36% Umber, American, raw 38% Verona green (terra verte or green earth) 32% Vermilion, English (quicksilver) 14% Vermilion, American (chrome red) 16% Paris green, American 23% Zinc chromate (permanent yellow) 15% [Illustration: Lampblack] [Illustration: Graphite] [Illustration: Mineral Black] [Illustration: Asbestine and Whiting] [Illustration: Silica and Asbestine] CHAPTER IV PHYSICAL LABORATORY PAINT TESTS For the paint chemist who desires to familiarize himself with the more recent analytical methods worked out in American laboratories, reference may be had to treatises on the analysis of paints, by Gardner and Schaeffer,[16] and Holley and Ladd.[17] Analytical methods are not included in this chapter, the writer's desire being to treat the subject from the standpoint of the physical properties of painting materials. The work outlined herein is of a nature that affords a wide field of research, and a brief study will doubtless suggest similar work to the student of paint. [16] The Analysis of Paints and Painting Materials. McGraw-Hill Book Co., New York, 1910. [17] Mixed Paints, Color Pigments and Varnishes. John Wiley & Sons, New York, 1908. =Preparation of Paint Films.= The study of paint films is one that has become of vital importance, and is receiving at the present time great attention. Among the many methods which have been suggested and attempted for securing paint films, a few already well known may be mentioned. By painting upon zinc and eating away the zinc with acid: The objection to this method is very evident, namely, the action of the acid upon the paint coating, which is likely to be very severe. Another method has been to spread paraffin on a glass plate, and painting upon this surface. When the paint is dried, the paraffin is melted off and thus the film is obtained. This method is open to objections, in that the paraffin surface is not a comparable one upon which to paint, and also that the complete removal of the paraffin is not assured. Another method consists in covering a piece of glass with tin foil, painting out the film upon the foil, and after drying properly, to remove the sheet of foil with its coating of paint and immerse in a bath of mercury which, by amalgamation of the tin, leaves the paint film. We now come to a method worked out in our laboratories, which can be recommended as being not only simple but efficient and practical. It has been found that a size from noodle glue, when painted upon ordinary fair-quality paper, makes a surface from which the paint may be subsequently stripped. The paint is applied in the ordinary way to the paper, which is held during the operation by thumb tacks, and allowed to dry. The paint may be separated by immersion in water kept at about 50 degrees Centigrade. By this method large films may be obtained, but it has been found very unhandy to work with films exceeding an area of eight inches square. When the film of paint has been detached from the sized paper through the dissolving of the noodle glue, the paint film is then immersed in a fresh solution of water, in order to remove whatever excess of noodle glue there may be remaining. A glass rod is then introduced into the bath, in which the paint film is floated upon the glass rod, which is then hung up to dry in a suitable container to prevent the accumulation of dust, etc. [Illustration: Bottles Showing Relative Permeability of Films by Amount of Whiting Formed Within] =The Permeability of Paint Films.= A series of tests were made to determine the water-excluding values of various combinations of painting pigments ground in pure linseed oil. White pine boards, six inches long, four inches wide, and one inch thick, were carefully prepared and numbered and given three coats of a white paint formula of the corresponding number. After drying, the boards were carefully weighed and immersed in a tub of water for three weeks. After removal, the surfaces of the boards were dried with blotting paper and the boards weighed. The gain in weight, corresponding to the amount of water penetrating through the pores of the wood, was observed. The boards were again immersed and at the end of two months the following results were obtained: Grammes of water Formula absorbed No. through paint 1. Soya bean oil 120 2. Linseed oil 102 3. Calcium sulphate 93 4. Barytes 88 5. Asbestine 74 6. Corroded white lead 59 { Basic carb.--White lead 25% } { Basic sulph.--White lead 20% } 7. { Zinc oxide 25% } 58 { Calcium sulphate 25% } { Calcium carbonate 5% } 8. Sublimed white lead 56 9. Zinc oxide 56 { Zinc lead white 30% } 10. { Zinc oxide 40% } 42 { Basic carb.--White lead 20% } { Calcium carbonate 10% } 11. { Basic carb.--White lead 50% } 42 { Zinc oxide 50% } { Basic carb.--White lead 38% } 12. { Zinc oxide 48% } 38 { Silica 14% } The test boards were then exposed, with their content of water, to the action of the sun's rays. Blistering of the painted surfaces took place in many cases, caused by the rapid withdrawal of the water and its consequent action on the paint film. The tests seem to indicate that a mixture of white lead and zinc oxide, with or without a small percentage of the inert pigments, is not as subject to the action of the water as the single pigment paints. In order, however, to corroborate these tests, it occurred to the writer to develop a more visible means of demonstrating the passage of moisture through paint films. [Illustration: Bell Jar Apparatus for Testing Permeability of Paint Films Paint films sealed over mouths of Bottles containing Lime Water. Carbonic Acid Gas generated under Bell Jar passes through Plate Films and precipitates Calcium Carbonate] Another series of white pine boards were therefore soaked in a solution of iron sulphate for several hours. After removal, the surface of each board was dried and coated with one coat of the paints previously tested. After thorough drying for forty-eight hours, there was placed on the surface of each board a few drops of a solution of potassium ferrocyanide. This solution has the effect of producing a blue coloration with iron sulphate, and in every case when it was placed on a paint of considerable porosity, the solution penetrated through and formed a blue coloration beneath the paint. The results corroborated the original tests referred to above. A series of sheets or films of paints were then prepared according to the method referred to on page 71. These films were placed over glass dialyzing cups, allowing the inner surfaces to sag so as to hold a small amount of dilute ammonium chloride solution. Distilled water was placed on the reverse side of the dialyzing apparatus and the tests started. At the end of six days the distilled water in each test was examined and the following results obtained: Test No. 1 (corroded white lead and asbestine film) allowed the passage of 0.002 gm. ammonium chloride. Test No. 2 (corroded white lead and zinc oxide film) allowed the passage of 0.0003 gm. ammonium chloride. Tests were also made with dilute solutions of other salts such as ferric chloride, having a dilute solution of potassium sulpho-cyanide on the reverse side of the apparatus. In the latter case the formation of a pink color, characteristic upon the mingling of these solutions, was obtained in a few hours. =Film-Testing Machine.= A film-testing apparatus, termed a "filmometer" by its originator, Mr. R. S. Perry, was constructed, with the following features: A graduated upright tube is fixed by means of sealing wax to two metallic plates which carry an evenly bored hole, exactly under the hole in the upright tube. This hole measures exactly one square centimeter in area, and is circular. The upright tube is graduated into lineal centimeters and is called the pressure tube. [Illustration: Gardner Accelerated Test Box] [Illustration: Perry Film Testing Machine] Attached to the lower end of this pressure tube, close to the metallic plates which serve as carriers for the paint film to be tested, is a side-neck, which is inclined at an angle of 45 degrees to the pressure tube, and serves the purpose of introducing the mercury, as will be described later. Immediately under the openings in the metallic plates which carry the film are arranged two pieces of iron inclined at a 90-degree angle, so arranged that when the pressure of mercury is applied and causes rupture of the film, the falling mercury shall be caught between these two insulated plates and cause contact. These two plates are connected up by wire with a pair of magnets, thence to an electric bell, and from there to storage batteries which supply the current. A film of paint is tested in the following manner: A piece of film one inch square is cut out and placed between the two metallic plates which hold the film immediately under the pressure tube. Mercury is run in from a burette through the side-neck and applies pressure upon the film by gravity. As the mercury is run in it rises of course in the tubes until this pressure becomes so great as to finally break the film. At this point the mercury will run out, and, falling upon the two insulated iron plates immediately below, will cause contact and close the circuit which rings an electric bell, which is a signal for the operator to shut off the inflow of mercury through the side-neck from the burette. The pressure tube is also supplied with a piston which is made of a piece of thin iron wire having a disc attached to its lower end. As the mercury rises in the pressure tube this iron wire is pushed up, being very delicately counterpoised over a wheel. Upon the breaking of the film the mercury runs out, but upon falling upon the two iron plates underneath causes contact to be made, which causes the current to run through the pair of magnets before mentioned, which, becoming electrified, attract the piston in the pressure tube, giving a reading for the maximum height of the column of mercury. [Illustration: Diagram of Perry Filmometer] The supply of mercury being shut off, the operator is now in a position to determine the total sum of both the elasticity and ductility of the paint film, and also the pressure at which the film broke. The breaking pressure of course is read directly upon the pressure column, which is divided into centimeters as has been described above, the piston indicating the maximum height of the mercury column. What may be termed the elasticity of the film can now be calculated. As is perfectly evident, the film in stretching does so by distending from a flat surface to a curved or cup-like surface. If the pressure tube is calibrated in cubic centimeters reckoned from a flat surface where the film was introduced, the stretch of the paint film in distending from a flat surface to a curved surface may be determined. The cubic contents of the pressure tube and side-arm become increased, owing to the cup-like shape the paint film takes on. By subtracting the amount of mercury indicated by the piston in the pressure tube from the amount of mercury delivered from the burette, the amount contained in the distended paint film is obtained, which serves as a measure of elasticity. The temperature is a most important point to consider in running daily tests upon the filmometer. The tests made by the writer were conducted at 70 degrees Fahrenheit throughout. [Illustration: Gardner-de Horvath film testing apparatus] =Gardner-de Horvath Filmometer.= Another type of filmometer which gives very concordant results was recently devised by the writer and de Horvath. This apparatus is shown above. It consists of a three-necked Wolff bottle having provision at one of its necks for exhausting the air from the bottle. The reverse neck is provided with a gauged glass tube dipping into a porcelain crucible containing mercury, thus acting as a manometer. The middle neck is fitted to accommodate two ground glass plates. Both these plates are provided with a central orifice one millimeter in diameter. Between the plates is placed a small section of paint film. The plates may be pressed together or clamped together and placed over the middle neck of the bottle, a close contact being made with Canada balsam. As the air is exhausted from the bottle, the mercury in the tube will rise and continue in its ascent until the film, which is exposed to atmospheric pressure, has offered it maximum resistance, which is shown by the breaking point. This point is observed on the manometer and the result expressed in centimeters of mercury. =Table of Film Testing Results.= By means of the Perry film-testing apparatus, described in the above, interesting results have been obtained, which are embodied in the following table: COMPARATIVE STRENGTHS OF FILMS AS OBTAINED BY THE BREAKING MACHINE ============================+=========+==========+===========+======== |No. Coats| Pressure | Thickness | Stretch ----------------------------+---------+----------+-----------+-------- 1. Zinc oxide | 3 | 33.2 | 0028 | .30 2. Zinc lead | 3 | 32.7 | 0034 | .35 3. Asbestine | 3 | 28.0 | 0045 | .15 4. Sublimed white lead | 3 | 17.9 | 0024 | .38 5. Barytes | 3 | 13.3 | 0042 | .33 6. Lithopone | 3 | 13.1 | 0024 | .49 7. Whiting | 3 | 13.0 | 0033 | .32 8. Quick process white lead| 3 | 11.3 | 0025 | .38 9. Gypsum | 3 | 10.8 | 0039 | .29 10. China clay | 3 | 10.8 | 0035 | .16 11. Silex | 3 | 9.6 | 0032 | .32 12. Blanc fixe | 3 | 8.5 | 0030 | .28 13. Corroded white lead | 3 | 7.3 | 0020 | .33 14. Barium carbonate | 3 | 7.2 | 0028 | .16 ============================+=========+==========+===========+======== By means of this machine it is possible to obtain very valuable information concerning the effect of age upon a paint as influencing its strength and elasticity. These are two vital qualities in a paint, as it is through its strength that a paint resists abrasion, cracking, peeling, and blistering. That elasticity is a vital qualification of a paint may easily be seen through the checking of oil paintings, which, as Ostwalt has pointed out, is due to the unequal coefficients of expansion between the ground and the paint. This is particularly noticeable in the alligatoring of many enamels which contain large percentages of zinc. Curves have been prepared having pressure as an abscissa and elasticity as ordinate. These curves show remarkable differences in different pigments. For instance, in the case of white lead, the curve takes a steep upward trend when it apparently reaches a maximum, the curve then flattening out and finally taking another steep upward trend just before breaking. This may be construed as follows: That under low pressures the white lead film is perfectly elastic, when a maximum is obtained, beyond which elasticity does not extend. This point is the maximum point of the upward trend. From here on pressure may be applied without any increase in stretch, this being represented by the flat part of the curve, while the steep upward trend just before breaking shows where the paint begins to tear, finally culminating in breaking. In the case of asbestine, however, the curve is more of a straight line up to the breaking point, which would go to prove that elasticity is proportionate to pressure in the case of this pigment. =Moisture Absorption.= The structure of certain pigments is such that when they are ground in linseed oil and painted out, films are produced which are very water-resistant. This action is possibly due to the filling of the voids in the oil, thus making a compact and water-resistant film. Pigments which are coarse and which present an angular crystalline structure, often produce films which contain a relatively large number of voids and are less waterproof. Certain pigments are chemically active and tend to produce, when ground in oil, metallic soaps which act for a time more or less as varnish gums, in keeping out moisture. Later on, however, such films are apt to break down and admit moisture in quantity. The tests herein described were designed by the author to determine the water-excluding value of a number of typical pigments when ground in linseed oil and painted out into films. Unfortunately, no method has been devised by which films of the same gauge could be prepared. The variations in the thickness of the films used in these experiments, however, are not very great. [Illustration: Apparatus for Determining Excluding Properties of Paint Films] A series of small glass bottles with wide mouths, holding about two ounces, were half filled with concentrated sulphuric acid, and paint films were tightly sealed over the mouths of the bottles with Canada balsam. The bottles were then carefully labeled, numbered, and accurately weighed upon chemical balances. Later they were exposed under a large glass bell jar containing air saturated with moisture and kept at a constant temperature. The bottles were removed from the receptacle every week and reweighed. The increase in weight, due to the amount of moisture which had penetrated through the films, and absorbed by the sulphuric acid, owing to its hygroscopic nature, was thus determined. In another series of bottles, lumps of calcium chloride were substituted for the sulphuric acid. The results obtained from these tests correspond to those of the former tests, and led to the conclusion that the porosity of linseed oil films varied when different pigments were used in the oil. MOISTURE EXPERIMENTS Figures Given Express Percentage Gain in Weight, e.g., Water Absorbed ==========================+=========+=========+========= | 7 days | 21 days | 49 days --------------------------+---------+---------+--------- White lead and zinc oxide | 0.043% | 0.115% | 0.266% Zinc lead white | 0.049 | 0.130 | 0.284 Red lead | 0.049 | 0.130 | 0.295 Sublimed white lead | 0.049 | 0.128 | 0.292 Zinc chromate | 0.064 | 0.176 | 0.417 Zinc oxide | 0.065 | 0.172 | 0.391 Barytes | 0.074 | 0.202 | 0.466 Willow charcoal | 0.077 | 0.236 | 0.694 Lithopone | 0.083 | 0.228 | 0.550 Chinese blue | 0.092 | 0.276 | 0.671 Natural graphite | 0.104 | 0.350 | 0.951 Ultramarine | 0.119 | 0.336 | 0.814 ==========================+=========+=========+========= Another series of tests was started, in which were used films prepared from various oils and varnishes made especially for the test from different gums. The results of this series are very interesting, as they indicate that certain gums are more powerful than others in making oils resistant to moisture. The reader should study with care the data on treated Chinese wood oil, most excellent results having been obtained when it was used in the proper percentage. EXCLUDING TESTS ON OIL VEHICLES AND VARNISHES SHOWING PERCENTAGE OF MOISTURE ABSORBED AT VARIOUS PERIODS ===================================+=========+=========+========= | 6 days | 18 days | 24 days -----------------------------------+---------+---------+--------- Linseed oil, 100% | .233 | .686 | .895 Soya bean oil, 100% | .340 | 1.06 | 1.39 Linseed oil, 80% } | .250 | .755 | .987 Soya bean oil, 20%} | | | Linseed oil, 60% } | .289 | .857 | 1.125 Soya bean oil, 40% } | | | Linseed oil, 40% } | .355 | 1.05 | 1.39 Soya bean oil, 60%} | | | Linseed oil, 20% } | .260 | .789 | 1.03 Soya bean oil, 80% } | | | China wood oil treated, 100% | .130 | .297 | .375 Linseed oil, 80% } | .182 | .559 | .728 China wood oil treated, 20%} | | | Linseed oil, 60% } | .173 | .540 | .708 China wood oil treated, 40% } | | | Linseed oil, 40% } | .119 | .348 | .450 China wood oil treated, 60%} | | | Linseed oil, 20% } | .127 | .375 | .494 China wood oil treated, 80% } | | | Kauri gum, 33% } | | | Linseed oil, 33%} | .061 | .191 | .302 Turpentine, 33% } | | | Kauri gum, 25% } | | | Linseed oil, 50% } | .096 | .266 | .346 Turpentine, 25% } | | | Kauri gum, 20% } | | | Linseed oil, 60%} | .122 | .367 | .449 Turpentine, 20% } | | | Kauri gum, 15% } | | | Linseed oil, 70% } | .187 | .421 | .601 Turpentine, 15% } | | | Congo copal gum, 20% } | | | Linseed oil, 50% } | .228 | -- | -- Turpentine, 30% } | | | Sierra Leone copal, 20% } | | | Linseed oil, 50% } | .099 | -- | -- Turpentine, 30% } | | | Zanzibar gum, 20% } | | | Linseed oil, 50% } | .082 | -- | -- Turpentine, 30% } | | | Amimi gum, 20% } | | | Linseed oil, 50% } | .080 | -- | -- Turpentine, 30% } | | | Boiled linseed oil (linoleate type)| .210 | -- | -- Collodion solution (6 oz.), 80% } | .201 | -- | -- Boiled linseed oil, 20% } | | | ===================================+=========+=========+========= [Illustration: Microscopic view of section of cedar] [Illustration: Microscopic view of section of maple] [Illustration: Microscopic view of section of white pine] [Illustration: Gardner photomicroscope in position against painted surface] [Illustration: Inside White on White Pine] =Use of the Microscope.= 4. The microscope is a necessary adjunct of every well-ordered paint laboratory, as has been recognized throughout the whole paint industry. The writer has attempted to collect certain data which may materially assist those manufacturers who employ this instrument to judge of the quality of their raw and finished products. The fineness of grinding considerably affects the quality of the paint, and this can be easily controlled through the intelligent use of the microscope. This instrument may also be used to detect certain adulterations. Appended is a table giving the fineness of grinding of the various pigments, together with their characteristics under the microscope. In this table measurements are given both in millimeters and in inches, in order to accommodate itself to the use of those chemists employing a millimeter stage micrometer, or those employing the English or inch system. Although it is not yet certain that any and all combinations of pigments may be detected under the microscope the writer is working toward a method which will allow a manipulator to judge of the composition of the paint under observation. In order to properly prepare a paint for microscopic examination, the following method is recommended: A microscopic turn-table is a convenient accessory of the microscope, and its use is to be recommended. A glass slide being placed in position upon the turn-table, a very small amount of either the pigment rubbed up in oil, or the paint, is applied to the slide; a small drop of Canada balsam is then applied by means of a glass rod dipped in a solution of balsam in xylol, and dropped upon the slide. The rod is then used to thoroughly incorporate the pigment with the balsam, and a cleaned cover glass is dropped over the whole and pressed down tightly, so that a small amount of balsam will exude from under the edges and thus firmly seal the glass. In order to make permanent slides it has been found advisable to rim the cover glass with balsam and even follow this up with some suitable black varnish, the slide being then carefully labeled and placed in the collection. Following is a table of the characteristics of the fourteen chief pigments: TABLE OF THE SIZE OF PARTICLES OF THE CHIEF PIGMENTS WITH THEIR CHARACTERISTICS UNDER THE MICROSCOPE ===+===================+======================+======================= | | Diameter in | Diameter in | | Millimeters | Inches | +-------+-------+------+-------+------+-------- No.|Name | Small | Aver. |Large | Small | Aver.| Large ---+-------------------+-------+-------+------+-------+------+-------- 1|Asbestine |.002 | -- |.12 |.00015 | -- |.049 2|China clay |.003 | -- |.065 |.00009 | -- |.025 3|Barium carbonate |.00076 |.0055 |.0172 |.00003 |.00024|.0011 4|Blanc fixe |.00073 |.0037 |.0073 |.00003 |.00014|.0003 5|Silex |.0037 |.0092 |.03 |.00014 |.00036|.0012 6|Gypsum |.0037 |.011 |.05 |.00014 |.00044|.0022 7|Amer.-Paris white |.0015 |.0050 |.04 |.00006 |.00022|.0018 8|Barytes |.0015 |.0092 |.05 |.00006 |.00036|.0021 9|Zinc lead |.00037 |.0018 |.0037 |.000014|.00007|.00014 10|Sublimed white lead|.00037 |.0018 |.0037 |.000014|.00007|.00014 11|Lithopone |.00076 |.0018 | -- |.00003 |.00007| -- 12|Zinc oxide |.00046 |.0018 |.00037|.00002 |.00007|.00014 13|Quick Pro. lead |.00061 |.0030 |.0048 |.00002 |.00012|.00018 14|Dutch Pro. lead |.00061 |.0018 |.0066 |.00002 |.00007|.00026 ===+===================+=======+=======+======+=======+======+======== =Film Sectioning and Deductions to be Drawn Therefrom.= 5. Investigations were undertaken into the innermost structure of paint films as revealed under the microscope. Up to the present time, work has been done upon barytes, asbestine, blanc fixe, and white lead, painted upon wood, and a combination paint upon wood. The films, the preparation of which has been described in the foregoing, were sectioned and prepared for microscopic examination in the following manner: A solidifying dish was partly filled with low melting-point paraffin which was allowed to harden, when a small piece of paint was thrown upon it and then more paraffin poured over it. After hardening, sections were obtained of the paint film by means of a microtome. [Illustration: Section Barytes Film] A view of these sections of paint films under the microscope gave to the operator a better idea of the structure of a paint than had ever been afforded heretofore. It was easy to perceive the relative position of the pigment particles and the three coats. The penetration of one coat into another was easily discernible, and measurements were made upon the sections in order to determine the average thickness of coat and its general appearance. Sections were also made of Inside and Outside White upon wood. These sections revealed under the microscope the thickness of the coats and also the penetration of the priming coat into the wood. Appended is a table giving microscopic measurements. PAINT SECTION MEASUREMENTS UNDER MICROSCOPE ======================+=============+===========+====== | |Millimeters|Inches ----------------------+-------------+-----------+------ Barytes |3 coats (sum)| .1068 |.00421 |Single coat | .0356 |.00140 | | | Inside. White on wood |3 coats (sum)| .1624 |.00639 |Outside coat | .0230 |.00091 |Next coat | .0443 |.00175 Field in photographs |Next coat | .0620 |.00245 |Penetration | .0294 |.00116 White lead |Inside | .0215 |.00085 |Middle | .0405 |.00159 |Outside | .0184 |.00073 |3 coats (sum)| .0811 |.00319 Asbestine |3 coats (sum)| .1840 |.00725 | | | Blanc fixe |3 coats (sum)| .1068 |.0042 |Single coat | .0356 |.00014 | | | Outside. White on wood|Outside coat | .1329 |.00523 |Inside | .1845 |.00727 |Penetration | .0737 |.00290 ======================+=============+===========+====== =Polar Micro-Examinations and Photomicrographs.= By Polar Micro-Examination is meant the examination of pigments under polarized light. A polarizing apparatus, though not an essential in the hands of the paint chemist, is nevertheless much to be desired, for by its help deductions may be drawn as to the contents of a paint, which by other means might not be possible. The polarizing apparatus as marketed by most manufacturers of the microscope is attached in the following manner: The diaphragm immediately under the sub-stage container is swung out and opened to its widest limit, allowing the insertion of the polarizer. This polarizer carries one of the pair of Nicols prisms and is countersunk to allow of the introduction of gypsum or selenite plates. The analyzer fits over the eyepiece on the tube. The use of polarized light upon paint is valuable on account of its action upon crystalline substances. The re-enforcing pigments, such as Asbestine, China Clay, Gypsum, Silex, Barytes, etc., are crystalline and consequently act upon the polarized light. In most cases these pigments are used in ready-mixed paints in small amounts, varying between 5 and 25%. When a slide containing a small amount--for example, less than 3%--of these crystalline pigments is examined under the microscope by ordinary transmitted light, they will often escape observation, owing to the small amount in which they are present. However, in the case of polarized light, this could hardly happen. [Illustration: Microscopic View of Barytes under Polarized Light] A slide of paint containing these re-enforcing pigments is prepared in the usual manner. On examining this under the microscope and using the polarizing apparatus, the crystalline pigments are at once detected by revolving the analyzer. At one position of the analyzer, one sees an ordinary field, as with transmitted light, but if one revolves the analyzer, the field gradually becomes darker until total darkness is obtained throughout, except in such places where crystalline substances are present, when the crystal is shown up with beautiful distinctness. Photomicrographs of various single pigments and pigment combinations are shown under Chapter III. =Effect of Pigments on Oil.= Certain pigments have the property of acting upon the linseed oil in which they are ground, forming metallic linoleates which accelerate the drying of oil. This is especially true of lead and zinc pigments. The inert crystalline pigments, when ground in linseed oil and painted out, distribute the oil so as to allow a great surface to be exposed to the air. Thus by physical action, and possibly catalytic or contact action, these inert pigments stimulate the drying of oil paints in which they are ground. Lead and zinc paints, of course, have the greatest drying values on account of the added effect of the linoleates formed, as outlined above. The writer has made a series of tests in which the action of various pigments upon linseed oil is shown. The tests were made in the following manner: Five grams of each of a series of commonly used paint pigments, including those of inert crystalline nature as well as the more valuable amorphous pigments which are considered more or less chemically active, were ground separately in an agate mortar, with 5 grams of raw linseed oil. The ground paste in each case was placed in a marked glass beaker, and allowed to stand in a dustless section of the laboratory for one month. The oil-pigment paste from each beaker was then separately extracted with benzine to remove the linseed oil from the pigment. The benzine solutions of oil were then heated to remove the benzine and the residue of oil burned to ash in crucibles. The ash from each test was weighed, and if it ran above the percentage of ash determined on a blank sample of linseed oil (namely, .003%), the ash was analyzed qualitatively for metallic constituents. The following table of results shows the percentage increase in ash, as well as the constituents of ash on the various samples tested: TABLE OF RESULTS ===============================+==============+======================== | Per cent. of | | Ash in Oil | Pigment in Oil |Extracted from|Analysis of Ash | Oil-Pigment | | Paste | -------------------------------+--------------+------------------------ Raw linseed oil without pigment| 0.003 | -- Barytes | 0.003 | -- Blanc fixe | 0.003 | -- Silica | 0.003 | -- Asbestine | 0.005 | -- China clay | 0.007 | -- Whiting | 0.008 | -- Chrome yellow | 0.025 |Lead oxide (PbO) Lithopone | 0.031 |Zinc oxide (ZnO) Prussian blue | 0.032 |Iron oxide (Fe_{2}O_{3}) Sublimed white lead | 0.033 |Lead oxide (PbO) Zinc oxide | 0.105 |Zinc oxide (ZnO) Corroded white lead | 0.116 |Lead oxide (PbO) Red lead | 0.2112 |Lead oxide (PbO) ===============================+==============+======================== Observation of these results shows that pigments such as Barytes, Blanc Fixe, and Silica have no chemical action on the linseed oil. The results on Asbestine and China Clay also are negative, the extremely slight increase in amount of ash from these samples probably being due to traces carried over mechanically into the oil mixture; the last named pigments being more fluffy and difficult to separate from oil. Slight action seemed to be apparent in the case of whiting, a pigment somewhat alkaline in nature. A longer test might have shown this pigment to have possessed still greater action. Corroded white lead showed considerable action, resulting in the formation of lead linoleate or some other organic compound. Zinc oxide and lithopone, the latter pigment containing 30% of zinc sulphide, both indicated action on the oil. Chrome yellow (chromate of lead) showed some action, as did also Prussian blue, the ash from the last named pigment showing a heavy percentage of iron oxide. Red Lead showed a most astounding gain in these tests, chemical action of the pigment on the oil being apparent soon after the tests were started, as shown by the formation of a hard cake with the linseed oil. The Raw Linseed Oil which was used in these tests had an acid value of 1.84%, which is very low. The neutralization of this free fatty acid by some of the alkaline pigments used, may account for part of the increased percentage of ash, but in most cases the pigments, and more especially the basic pigments, had a direct saponifying action upon the glycerides of the oil. CHAPTER V THE THEORY AND PRACTICE OF SCIENTIFIC PAINT MAKING =Laws of Paint Making.= To secure a proper comprehension of the composition of paints, and to be able to interpret the functions of their various constituents, requires an understanding of the general physical principles involved. The modern grinder has accepted the Law of Minimum Voids, and upon this law he bases the design of paint formulæ, aiming toward the production of what have been properly termed Scientifically Prepared Paints. Perry's formulation of the Law of Minimum Voids in a paint coating, and the analogy which he has drawn between a scientifically prepared paint and a well-proportioned concrete, was the result of genuine scientific thought following observation and experimentation. It must be admitted that analogies are not always safe to draw conclusions from, but it surely is no fallacy in reasoning to draw analogies between these two materials, when they resemble each other in so many ways. To carry out processes of reasoning, and to formulate laws from such close analogies, is certainly a step in the right direction. A graphic summary of the analogies between a properly proportioned concrete and a paint, are shown on next page. Although this table graphically summarizes the principles involved, the matter is presented with greater clearness in the following: Law No. 1--The law of minimum voids to be observed in constructing a paint formula--this law having already been accepted as mathematically correct and technically proved in the technology of concrete and cement. Corollary--The requisite thickness of a paint film together with the utmost attainable strength and impermeability can best be obtained by a properly proportioned blend of pigments of three or more determinate sizes. AN EXHIBITION OF CERTAIN ANALOGIES GOVERNING THE MANUFACTURE OF CONCRETE AND OF PAINT 1 Concrete aggregate = solids + vehicle|Paint aggregate = solids + vehicle | 2 Solids = coarse + medium + fine |Solids = coarse + medium + fine (stone) (gravel) (sand) | {pulverized }{precipi-} |(pig- {cryst'lline}{tated }(fume) |(ments {(etc.) } | 3 Vehicle = |Vehicle = = reactive binder + evapor'g thinner |= reactive binder+evaporating thinner { cement and com- } (excess water) | (linseed oil) (volatiles) { bining water } | | 4 Solids + compacting = |Solids + compacting = (tamping) | (brushing) = elimination of accidental voids + | = elimination of accidental voids + + proper adhesive contact | + proper adhesive contact | 5 Vehicle + reaction = hydrosilicates, |Vehicle + reaction = linoxyn etc. | (setting) | (drying) | 6 Solids + vehicle + |Solids + vehicle + + lubrication + chemical reaction = | + lubrication + chemical reaction = = final product { solidified binder+}| = final product {solidified binder+} { + solids }| {+ solids } | 7 Final product = concrete |Final product = paint coating { shearing }| { strength } (of max. strength { tensile }| (of maximum { impermeability } { crushing, etc. }| { durability } * * * * * If we assume for both paint and concrete proper lubrication proper proportion of vehicle and solids Then the _essential difference_ between a thin film of Concrete and Paint is Cement Binder Linoxyn Binder _Disadvantages_ Non-elastic and hence an impracticable |Slowly perishable from oxidation by binder for a film to protect non- |the air. similar structural surfaces. | _Advantages_ Durable and with the qualities of a |Semi-elastic and therefore a practic- natural mineral. |able binder for a film to protect |structural surfaces. Postulate (def. Webster's Dictionary--A self-evident problem) Postulate No. 1--The organic linoxyn or semi-elastic binder of the paint vehicle (unlike the cement binder) is perishable and its purity, strength and protection from attack means life to the paint coating, and hence the _life_ of the oil is the _life_ of the paint. Postulate No. 2--The inorganic or powdered mineral solids of a paint coating will crumble unless held together by the binder, but the imperishable pigments must be so ground and blended in the binder that they will protect the binder and present the greatest possible solid front to the atmospheric attack. * * * * * A paint, to secure the greatest protection and life for the linoxyn, together with the durable qualities of cement, _Therefore_ Should expose to air decay within limits of physical strength |within limits required for elasticity, The greatest amount of pigm't material |etc. The least amount of exposed |linoxyn (which is) | or Durable and with the inert qualities of|Considering the linoxyn present be- natural mineral |tween pigment particles as the void |or point of attack, | Then |the minimum exposure of linoxyn or minimum voids obtainable by proportioned pigments of different particle sizes. Law No. 2--The law of the flat arch in paint coatings--i.e., the fact that in studying the fundamental physical principles governing the strength and durability of a paint coating it is necessary to regard the coating as consisting of a series of flat arches, in which the pigment particles of largest characteristic size serve as the piers or supports for the flat arches of which the continuous film is composed. Corollary A--The strength and durability of a paint coating is determined by the strength and durability of the piers or supports (which consist of the characteristic pigment particles of the largest size). Corollary B--Owing to their inherent strength and durability the pigment particles of largest characteristic size which serve as supports for the paint coating should consist, in part at least, of chemically inert pigments, such as natural crystalline barium sulphate, calcium carbonate, magnesium silicate, etc. Corollary C--It follows directly that the thickness of a paint coating is determined by the particles of pigments having the largest characteristic size, even if that pigment be present only in moderate percentage. Upon this principle depends the comparatively great thickness of film and moderate spreading rate of paints composed of such pigments as basic carbonate--white lead, red lead, barytes, etc., and the strongly contrasted thinness of film and high spreading rate of paints composed of the sublimated pigments such as lamp black, zinc oxide, basic sulphate--white lead, zinc-lead white, leaded zinc, etc. In commenting upon the announced laws set forth above, Heckel says: "The recognition of these laws was an exercise of pure deduction. Paint manufacturers before Mr. Perry's announcement were producing paints containing three or more pigments with particles of varying characteristic sizes; but their procedure was based largely on empirical knowledge, the result of accumulated experience, due to a conscientious endeavor to produce the highest type of paints for economic service. In the absence of any law to govern or to limit the use of the reinforcing pigments, inexperienced manufacturers had brought upon the market paints which were badly proportioned as to the several pigments, or burdened beyond the limits of effectiveness with reinforcing pigments. To all paint manufacturers Perry rendered a substantial service in deducing for them the laws set forth in his address. In the results following a recognition of these laws there was nothing new or startling, but Perry was the first to give the principles from which it can be determined in advance whether a paint formula will prove to be physically good or bad in practice. [Illustration: Series of Paint Chasers, Mixers, and Grinders] [Illustration: Overhead Churn Mixer] [Illustration: Battery of Paint Mixers and Grinders of Modern Underdriven Type] [Illustration: _Photographs courtesy of Ernest Heath_ View showing Shrinkage in Bulk of Paint Pigment after being ground in Oil. Filled Barrel on Right with the Oil forms one-third Barrel Paste as shown in Barrel on Left] [Illustration: View showing careful Dressing of Bull Stone Mill from Grinder] "As has been before stated, he was not the first to recognize the law governing minimum voids, but by that scientific use of the imagination which Tyndall so highly commends, he recognized, as by inspiration, the fundamental similarity existing between a film composed of solid particles cemented together by a semi-solid homogeneous menstruum and a layer of concrete composed of solid particles cemented together by a solid homogeneous medium. His application of the law permits the paint manufacturers to design a paint formula with full knowledge of the controlling conditions, so that it shall produce a coating neither too thick, and therefore uneconomical and subject to excessive internal strains, nor too thin, and thus weak and inefficient for protection. That Mr. Perry's contention was well-founded, other paint technologists have since demonstrated; notably Mr. Wirt Tassin, in his microscopic studies of paint films in situ, and Prof. G. W. Thompson who, in his address to the Penna. Association of Master Painters at Reading, said:--"I want to agree with Mr. Perry * * * where he says that a pigment should be made up of particles of different sizes. Mr. Perry also draws a further parallel between paint and concrete where he refers to the form of the reinforcing pigment particles and suggests that in paint coatings as in concrete a field can be found for the chemically inert pigments with rod-like or hair-like structure, to strengthen the film, just as the steel rods and iron mesh are used to reinforce concrete in structural work--a suggestion which, since the first publication of the address, has been widely accepted as a practical aid in the manufacture of good paints."" =Use of Inert Pigments.= There seems to be no reasonable doubt as to the efficiency of a small amount of inert pigments in paint, and the writer has often compared the manufacture of paint of the above type to the making of various alloys wherein zinc, copper, and other metals are added to gold in order to make a product possessed of greater durability, etc. [Illustration: Batteries of Color Grinding Mills] There has been considerable inquiry as to just what is meant by the statement that "a moderate percentage of inert pigments, combined with properly adjusted mixtures of white lead and zinc oxide, have given wonderful service in all the tests." The writer has been asked to define what "moderate" means. A "moderate percentage of inert pigments" should be defined as that amount of natural crystalline pigments that will, when mixed with white lead and zinc oxide, not materially detract from the hiding power of white lead and zinc oxide. It is possible to mix a certain percentage of these crystalline pigments with white lead and zinc oxide, and, by thorough grinding, incorporate them in such a manner that the mixture will show nearly as good a hiding power as the straight white lead and zinc oxide. When certain limits have been reached, however, and these limits must be determined by the manufacturer and painter in making practical tests, the further addition of inert pigments lowers the hiding power of the paint and therefore lowers the value of the paint. These remarks do not apply to artificial crystalline pigments, such as precipitated whiting, which possess greater hiding values than the natural pigments. =Perry's Principles of Paint Making.= Parts of the original paper[18] in which Perry so clearly set forth the principles from which the preceding laws were formed, follow: [18] Physical Characteristics of a Paint Coating. R. S. Perry. Michigan Chapter, Amer. Institute of Architects, 1907. =Sealing Quality or Imperviousness of the Coating.= "It has been emphasized that for durability and protection, the strength and imperviousness of a paint coating are vital factors. The protective value of the paint coating of course ceases with its chalking or disintegration, but, while it is true that the protecting or final life of the coating ceases with this disintegration, it is also true that a paint coating has always during its true life more or less porosity from the nature of the linoxin or oxidized linseed oil. Therefore during its protecting life the degree of its imperviousness influences its resistance to attack upon its own life and its protection of the underlying materials. The more impervious the paint coating without loss of strength, the slower the oxidation or disintegration of the paint coating itself and the greater protection to the underlying material. "A coating of linseed oil alone is not only weak, but the simplest and crudest experiments will show its porosity and this porosity increases rapidly with progressive oxidation, the porosity of course definitely hastening the over-oxidation or chalking. In proportion, therefore, to our success in filling the voids in the linseed oil film with proper pigment materials, we will in that degree succeed in excluding agencies of decay, not only from the mass of the paint coating itself, but also from the surface to be protected. These conditions are exactly parallel in the requirements and performance of the best-made concrete, and Taylor & Thompson in their work on concrete have clearly stated that to obtain imperviousness there must be freedom from voids, and that to obtain these conditions, the materials used must have at least three determining sizes. [Illustration: Equal Volume (One Cubic Centimetre) of Each Size of Shot Taken. Note that the Smaller Shot Cover more than Half as much again as the Larger Shot and the Voids are Smaller.] [Illustration: Diagram Illustrating Two Determining Sizes of Solid Particles in Concrete] [Illustration: Diagram Illustrating Three Determining Sizes of Solid Particles in Concrete] "'It is a fact that with particles of different sizes as against uniform size the densest mixture can be obtained. This is so evident as to require no proof.' It follows that the least density and hence the largest percentage of voids occur when the grains are all of the same size, and it is shown that the most voids occur in a mass of large particles. The least voids occur when the voids between the large particles are filled with smaller particles and when these smaller voids between the smaller particles are in turn filled with still finer particles. In other words--particles with three determining sizes will fill up a given space more completely than particles of two determining sizes and very much more completely than particles of one size. =Elasticity and Strength.= "The paint coating here again is governed by many of the laws which govern the similar material, i.e., concrete. We find, by again referring to Taylor & Thompson, on Concrete, page 275, that tests at the Watertown Arsenal on concrete convinced the investigators that the ultimate strength of a concrete is identical with the shearing strength of particles of stone making up the aggregate. "This means that in its ultimate form the good concrete will crack or shear through the broken rock contained therein, and resistance to shearing is directly proportionate to the strength of the broken rock chosen for the mixture. The film of semi-liquid linseed oil when fresh is extremely weak, but as it hardens, its characteristics and physical properties will obviously be those qualities which are a composite of the qualities of the solid particles and of the semi-solid linolein incorporated together in the paint coating. These physical properties of the suspended and incorporated pigments profoundly modify the film in this respect. "The dried vehicle, linoxin, is notable for its elasticity, and it is weak in crushing and tensile strength, and in hardness or resistance to surface wear. The fact that it is a semi-solid furnishes an opportunity to modify and improve those characteristics of a solid in which it is deficient. The semi-solid, rubber-like linoxin between the coarser particles of the pigment obviously uses these coarser particles as supporting points. The medium sized particles of the second group of alteration products serve the same purpose as the broken rock in concrete. The coarser particles absolutely do not, and can not, serve the purpose of stiffening or of reinforcing or modifying the consistency and qualities of the semi-solid linoxin, for a number of reasons, one of which may be mentioned, namely, that particles of the first, or coarse, class have a determining size which is a large fraction--a heavy percentage--of the total thickness of coating, and are in some instances thicker in diameter than the thickness of an oil coating not reinforced with the fine or fire group. "We must think of the coarser particles as piers. The mixture of linoxin with the other two groups of particles in the spaces between these coarser particles, or piers, is the true paint body and consists of flat reinforced arches which have the extra support of falsework, in the shape of the structural material on which the coating rests. Asbestine pulp, a natural product and one of our most important natural reinforcing pigments, serves not only in the coarse group as supporting particles for the linoxin arch, but also because of its peculiar properties serves the more important purposes of reinforcement. It retains, no matter how finely ground, its peculiar needle-like, or rod-like, form of particles, and obviously serves the purpose of reinforcing the flat arch of linoxin, exactly as iron bars or iron netting serve in reinforced concrete arches. The medium sized particles of the second group of pigments produced by chemical alteration or precipitation, serve the purpose of the broken rock in concrete, and together with the coarser supporting particles and the finest reinforcing particles, give minimum voids and a maximum imperviousness to agencies of internal decay. "It goes without saying that the pigments of any one group contain particles of dimensions which fall into the other two groups, but no one pigment supplies the correct proportion of each of the three required dimensions, and each pigment has so large a percentage of approximate dimensions as to bar it from exclusive use in the other two groups. Given similar homogeneous coatings under identical conditions, we recognize the law that elasticity will vary directly with thickness. Direct deduction from this law teaches us that of two paint coatings equal in wear, in strength, opaqueness, and in all other qualities except thickness, we should choose the thinner coating. Therefore if we have two paint coatings fulfilling every requirement, the first compounded with pigments giving a thicker coating and the second with pigments yielding a thinner coating, we must choose the second formula and obtain the thinner coating. =Adhesive Power.= "The adhesion of the linoxin to the coarse group of particles and to the underlying material is vital to the life of the paint coating. If the coating parts from the surface beneath, we have scaling or peeling. It is universally admitted that this will result from use of zinc oxide as the sole pigment. We have only to conceive of our flat arch of reinforced linoxin and leave out our points of support, to realize that this is the inevitable result if the coating be subject to extreme exposure, although good results may be obtained from zinc oxide used alone, as, for instance, in interior house painting where extreme changes of temperature and exposure are avoided. "Three major lines of force hold our linoxin in place--adhesion toward the underneath surface, adhesion to the coarse particles, and cohesion within the linoxin itself. These lines must be represented by a flat arch of linoxin with a downward pointing magnet therefrom, to represent adhesion to the surface. Magnets on each side of the arch pointing toward the supporting coarse particles, and two magnets within the arch and pointing toward each other, or to the centre of the arch, these latter to represent the force of cohesion." CHAPTER VI THE SCOPE OF PRACTICAL PAINT TESTS =The Pigment Contention.= During the year 1906 officials of the North Dakota Agricultural Experiment Station examined a number of paints on sale in the northwestern States. The presence of large quantities of inert pigments as well as water, in some of these paints, prompted agitation for State laws requiring the formula-labeling of paints. Certain paints made of white opaque pigments such as white lead and zinc oxide were exempted from the statute. The white opaque pigments used in these paints were believed by certain manufacturers as well as by many prominent paint authorities of high standing to be benefited in their wearing value by the addition of small percentages of inert crystalline pigments, such as barytes, silica, China clay, etc. Laboratory experiments had already determined that these inert crystalline pigments had a certain definite action in increasing the life of paints, but it had become evident that they should be used with discretion, in moderation, and with a proper understanding of their limitations, if the best results were to be obtained. The addition of very large quantities of such pigments was not indulged in by discriminating manufacturers, but the exact percentage to use was a matter of great doubt, even to the most experienced. In order to determine just what percentage of crystalline pigments, admixed with white opaque paint pigments, would give the best service and results, it seemed imperative that practical paint tests should be made. A series of paint tests on commercial brands of paint had already been started at the Fargo Agricultural College, and, at the suggestion of the Paint Manufacturers' Association of the United States, another series of practical paint tests were instituted, and carried out under the supervision of Dr. E. F. Ladd, Director of the North Dakota Experiment Station. =Test Fences to Solve the Problem.= It was apparent that the pigment question could be solved only through field tests made on a comprehensive basis and placed under the control of scientific and technical societies of renown, so that they might be fair and unbiased from every standpoint. In order to secure a comparison of the wearing of different paint formulas in various sections of the country and under differing climatic conditions, another series of tests was started in the East soon after the North Dakota tests had been started. Simultaneously fences were erected at Atlantic City, N. J., and Pittsburg, Pa. The site of the Atlantic City fence is a strip of land running due north from Atlantic and Savannah Avenues and within a short distance from the Atlantic Ocean, the exposure being a severe one. The site of the Pittsburg fence is back of the athletic field of the Carnegie Technical Schools, the fence running east and west and being exposed to the heavily charged sooty atmosphere coming from the many industrial plants near by. =Construction of Framework of Fences.= At these two locations framework fences were built, upon which were placed a series of painted panels. Heavy yellow pine posts six inches square were set in the ground about six feet apart and to the depth of about four feet, upon a concrete base. The posts were solidly tamped and then braced at the top with supplementary studding braces two inches thick. Connecting the posts was a line of studding six inches by two inches, forming a solid framework, the bottom of which was approximately fifteen inches from the ground. The bottoms and tops of the fences were protected by heavy boards two inches thick, so that the moisture and rain might be prevented from working itself up into the wood. The whole fence was sheathed with twelve-inch planed white pine, thus forming a solid background for the test panels. =Lumber for Panels.= The lumber for the test panels was most carefully selected, being of three grades--white pine, yellow pine, and cypress. A large amount of each grade of lumber was secured, and after the best portion had been made up into panels, the panels were inspected by an expert lumber classer; nearly 40% being rejected on account of the presence of knots or sappy places which appeared upon the surface. Each of the panels finally passed upon as suitable for the test was branded with a hot iron with consecutive numbers running from 1 to 186. The grade of wood used for each panel was indicated by an abbreviated mark--W for white pine, C for cypress, and Y for yellow pine. In order that a record of each panel might be kept on file, previous to the application of paint to the panels, a complete series of photographs was taken of the panels in sets of four. This work seemed advisable so that the future failure of paint on any one panel, which might be thought due to faulty wood, could be either verified or refuted by a reference to the series of photographs made of the bare panels. [Illustration: View of Atlantic City Test Fence] =Construction of Panels.= The panels were constructed of Dutch weather boarding, tongued and grooved together in strips of three pieces and capped at the top with a weather strip, forming a finished surface three feet long and fifteen and a half inches high. They were firmly braced together at their backs and nailed in such a manner that no portion of the nails would appear on the surface of the panel, thus preventing the staining of the panel from rust. The construction of the framework of the fences at Atlantic City and Pittsburg was of such a nature that they would each accommodate 560 panels of this type. =Starting of Tests.= On account of the lateness of the season, it was found necessary to do the painting of the tests within a building, so that each formula might be subjected to fair and equal conditions of application, thus excluding the blowing of dust or rain upon the painted surfaces, which would have taken place had the panels been painted upon the fence. The painting of the panels began in January, 1908, the temperature within the buildings in which the work was done averaging 50 degrees Fahrenheit throughout the work. It was decided to test each formula in three colors, in duplicate, and on each grade of wood, exposing the duplicates on either side of the fence. Thus for one paint formula there were required 18 panels, or 6 painted in each color and on 3 grades of wood. =Paints for Tests.= The mixed paints received for the tests were in quart cans, having been especially prepared from the formulas submitted to manufacturers by the technical committee in charge of the work. They were properly labeled with their number and color, in each case. The formulas decided upon for the test are described later. The various white leads and other single pigment paints which were used were received in kegs weighing 12-1/2 pounds each, having been bought in the open market and then given a formula number. The formulas of the paints designed for both the Atlantic City and Pittsburg tests, as well as the numbers of the panels upon which the paints were applied, are shown on pages 131-133-145. The analysis of one of the combination paints applied is herewith given, to show the correct method of stating the composition of a paint. FORMULA NO. 20, ATLANTIC CITY TEST FENCE Percentage Composition ===================+=======+=======+=======+======= |Pigment|Vehicle| Total | -------------------+-------+-------+-------+------- Corroded white lead| 67.01 | -- | 42.84 | Zinc oxide | 19.89 | -- | 12.71 | Asbestine | 3.86 | -- | 2.47 | Calcium carbonate | 9.24 | -- | 5.91 | Raw oil | -- | 94.30 | 34.02 | Japan drier | -- | 3.89 | 1.40 | Turpentine | -- | 1.81 | 0.65 | -------------------+-------+-------+-------+------- |100.00 |100.00 |100.00 | ===================+=======+=======+=======+======= =Brushes.= Heavy 7-O round bristle brushes were used for the priming coat so that the paint might be well worked into the wood, while for the second and third coats three-inch chisel edge brushes were used. These brushes were, of course, washed several times with turpentine after painting each panel, so that pigments from one paint could not be carried over into a paint containing other pigments. [Illustration: Cypress Panels] =Shellacking Panels.= The shellacking of any bad places of minor nature which may have been present on the surfaces of some of the panels, was done with the highest grade orange shellac. It was thought advisable to determine whether shellacking over the priming coat of paint or on the bare wood previous to the application of the priming coat, was the better method. Panels Nos. 1 to 8 in each test were therefore shellacked over the priming coat, while on all other panels the shellacking was done directly on the bare wood previous to the application of the priming coat of paint. =Application of Paints.= In order to determine just how much paint was applied to each panel and to reckon the spreading rate therefrom, careful weighings were made during the application of every paint. This was carried out by placing a quart can of paint as received, upon a laboratory balance, the gross weight being taken and recorded. The can was shaken and its contents transferred to a quart-size enameled cup where with the aid of a paddle it was broken up into a mixture of even consistency. A portion of this paint was then transferred to two small sample cans carefully numbered with the formula number, for future reference and analysis. The reduction of the paint was then made. The brush used on the priming coat was placed with the pot and the paint on the balance and the weight taken by the official weigher. The pot was then given to the painter who applied the priming coat to one panel. The brush, pot, and paint were then handed back to the official weigher and the difference in weight recorded. From these data could be reckoned the spreading rate of the formula applied. The drying of the panels was noted every few hours and observations made to determine whether the paints were penetrating properly into the surface of the wood. A period of eight days was allowed between each coat in order that thoroughly hard setting might take place. During the application of the second coat of paint to the panels, fresh cans of paint were used in every case so that fresh reductions could be made of the proper consistency. Full data were also recorded on the ease of application, working, and nature of drying shown, as well as appearance presented by each paint after each coat had been applied. New packages of paint were also used for the third coat, and, as a rule, the paint was applied without reduction or with full oil reduction, turpentine being eliminated in nearly every case for the third coat work. =Reductions.= The single pigment paints, such as white leads, were reduced by the so-called ounce system, each ounce of oil added to 12-1/2 ounces of paste pigment representing one gallon of vehicle to one hundred pounds of lead. A complete report of the reductions, spreading rates, etc., used in the tests would take up three or four hundred pages of printed matter. The reductions shown on the following formulas are, however, fairly representative of the reductions used on the combination and single pigment paints. REDUCTIONS ON FORMULA NO. 2 _White and Yellow_ 1st Coat Condition when opened--good. Consistency when broken up--heavy. Reduction recommended by manufacturer--none. Reduction used--3 pints raw oil, 1 pint turps, 1 gallon paint. Consistency after reducing--good, stiff. Working--fair. Drying--fair on pines; cypress--poor. Penetration, pines--good; cypress--poor. 2nd Coat Consistency when broken up--heavy. Reduction used--1-1/2 pints turpentine, 1 pint boiled oil. Consistency after reducing--good. Working--good. Hiding--medium. Drying on pines--good; cypress--poor. One-half pint japan added to gallon of paint. Penetration--fair. 3rd Coat Reduction used--1-1/2 pints oil, 1/2 pint turpentine. _Reductions for Lead Pastes_ Calculated on 100 lb. keg. Formulas Nos. 37-38. (Corroded White Lead.) 1st Coat 6-1/2 gallons oil, 1/2 gallon turpentine, 1 pint turpentine japan. 2nd Coat 3-1/2 gallons oil, 1 gallon turpentine, 1 pint japan. 3rd Coat 3 gallons oil, 1 pint turpentine, 1/2 pint japan. =Hiding Power of Paints.= When the priming coat had thoroughly dried on each panel, the painter carefully stencilled a black Geneva cross over the priming coat with lampblack in oil. The object of this black cross was to make a determination of the comparative opacity or hiding power of the different paints applied. It is well known that various pigments when ground in oil differ in their hiding power in direct proportion to the difference in the refractive indices of the pigments and oils used, those containing high percentages of pigments such as white lead and zinc oxide being superior in hiding power. After the second and third coat of paint had been applied to each panel, there was evident a remarkable difference in the hiding power, as the black cross showed through in some cases quite clearly, while in other cases it was almost completely hidden. The hiding power of a paint is one of the properties which the master painter looks upon as most essential, but it should, of course, be accompanied in a satisfactory paint by good spreading power and longevity. =Actinic Light Tests.= After the drying of all the paints, it was decided that it would be of extreme interest to conduct a test on the resistance of certain paints to actinic light. It is well known that the ultraviolet or chemical rays of the sun are most energetic in causing chemical reactions that result in the early decay of certain types of paint. It was thought that the disintegrating effect of these rays, as well as their effect in the bleaching out of colors, might be prevented by placing upon certain panels small orange colored glass slides which would prevent the passing of these rays to the painted surface. The slides used were five inches long and three inches wide and were placed upon the middle board of certain panels, with picture framing, putty, and galvanized iron tacks. The preservation of the underlying surface from the sun's rays would, it was thought, prevent the deterioration of the paint, and at the same time preserve its original color so that it might be compared to the color of the exposed portion at the time of inspection. =Supervision of Tests.= The Atlantic City tests were under the constant supervision of Committee E of the American Society for Testing Materials, this committee having accepted the inspection of the fence. A representative was constantly present throughout the work in order to see that each formula received fair treatment. The actual painting work was under the supervision of the writer, together with a master painter representing George Butler who was chosen by the Master Painters' Association of Philadelphia as the official painter of the Atlantic City test fence. Mr. J. B. Campbell of Chicago also acted as an official of the Paint Manufacturers' Association in the application of the formulas to both the Atlantic City and Pittsburg fences. At Pittsburg the fence was placed directly under the supervision and control of the Carnegie Technical Schools, who chose for the fence work a committee of their technical force. Drs. James and Schaeffer of this institution were present throughout most of the work and were constantly represented during the test. The Pittsburg Master Painters' Association appointed a committee consisting of Messrs. Dewar, Rapp, and Cluley, for the actual painting work, and they were represented with the writer throughout the tests. Great interest was exhibited in the work by the committees in charge, and the skill of the practical painters, combined with the care of the inspectors, made the treatment of each formula fair and satisfactory. CHAPTER VII CONDITIONS NOTED AT INSPECTION OF TESTS =Inspection of Atlantic City Tests.= During the month of March, just one year after the placing of the painted panels on the Atlantic City fence, an inspection was made jointly by a committee representing the Master Painters' Association of Pennsylvania, the Scientific Section of the Paint Manufacturers' Association of the United States, and certain members of sub-Committee E of the American Society for Testing Materials. =Methods Used at Inspection.= One of the most important tests made when inspecting paint is the determination of the chalking taking place.[19] There was developed during the inspection of the Atlantic City panels a new method for determining the comparative chalking of the various paints. It was thought desirable to secure a method, if possible, that would show results which might be photographed and even tabulated in percentage form, if desired. The apparatus for the new test consisted of a small strip of black felt three inches wide by five inches long, placed across a small block of wood which would fit in the palm of the inspector's hand. This outfit resembled a blackboard eraser and was used in a similar way. By holding the apparatus firmly against the panel and drawing it half-way across the panel in a straight line toward the operator, there was obtained on the black cloth a white mark proportional in intensity to the amount of chalking which had taken place on the given area. When a series of these cloths were made, they were assembled and photographed for comparison. It should be noted that the above chalking test is useful only where the painted panels under examination have been exposed over a period of one to two years, during which period the chalking of paints has been shown to be greatest and the chalked surface of a fairly adherent nature. Where longer exposures have been made and where rains have removed from the painted panels a considerable amount of the chalked pigment which has formed, such a test would not be fairly representative of the amount of chalking which had taken place. [19] Mr. Macgregor of the Picher Lead Co. has just developed a new test to determine the relative imperviousness of paints which have begun to chalk. He draws a mark about two inches long upon the painted surface with a fountain pen. The ink mark will spread rapidly to a wide area if the chalking is of a bad order. If the chalking is slight and the film in good condition, the ink mark will not spread. [Illustration: Series of Black Felt Cloths used in making the Chalk Tests on the Various Formulas. Numbers over Cloths represent Panels] [Illustration: CHALKING.--Type of Decay Exhibited by Improperly Made Paint (magnified view)] [Illustration: CHECKING.--Type of Decay Exhibited by Improperly Made Paint (magnified view)] [Illustration: BLISTERING.--Type of Decay Exhibited by Improperly Made Paint (magnified view)] [Illustration: CRACKING.--Type of Decay Exhibited by Improperly Made Paint (magnified view)] [Illustration: GENERAL DISINTEGRATION.--Type of Decay Exhibited by Improperly Made Paint (magnified view)] [Illustration: SCALING.--Type of Decay Exhibited by Improperly Made Paint (magnified view)] =Gloss.= The gloss of the various panels was a condition which was also reported upon, the middle board of each panel being washed with a wet sponge one day before the inspection so that any surface dirt might be removed. By looking at a panel from the side, a day after the washing, the inspector was enabled to get a fair idea of the degree of gloss exhibited by each formula. =Hiding Power.= The hiding power of each paint was determined, as before described, by observing the degree to which the stencilled lampblack cross on the priming coat was visible through the second and third coats. Single pigment paints such as white lead possessed very great hiding power and obscured the black cross almost completely, while the cross was quite visible through paints containing high percentages of crystalline pigments. =Checking.= The checking of each panel was determined by examining with a small high-power hand glass magnifying fifteen diameters. It is well known that examinations with such a hand glass will not determine whether so-called fine matt checking is taking place, but it will determine whether checking has appeared to any marked extent. Fine matt checking is the first sign of the decomposition of a paint, and is preliminary to the visible checking seen by the naked eye, which is often followed by alligatoring. Examination of some formulas disclosed this so-called alligatoring and even the exposed wood between the fissured surface which had developed from what were at first fine hair checks. It is, in the opinion of the writer, possible to predict with a fair degree of accuracy by examination of a painted surface, one year after exposure, how the paint will wear in the future and what its appearance will be at the end of another year. =Hardness.= The hardness of each panel could not be determined with any degree of accuracy, but the inspectors were able to roughly determine this condition by very close inspection. From practical experience of the wearing of white lead and zinc oxide, and the comparative hardness of these two pigments, zinc oxide was selected as the maximum for hardness and termed number 10, while white lead was selected as the minimum and termed number 1. The varying degrees of hardness exhibited by the formulas were recorded in terms from one to ten. This comparison of course was only an approximate one. =General Condition.= The so-called general conditions of the panels was, as a rule, the consensus of the judgment held by the various inspectors, with due regard to such properties as chalking, checking, gloss, hiding power, color maintenance, condition of surface, etc. CHAPTER VIII RESULTS OF ATLANTIC CITY TESTS =Results on Various Woods.= On the Atlantic City Fence all the tests made on yellow pine and cypress were found to be in an unsatisfactory condition for a report, for in every case the sap and small knots contained in such wood had a very bad effect upon the paint, causing peeling and scaling. The white pine panels were in very much better condition, and it was therefore decided to make the inspection entirely from the white pine panels and in the future to remove the yellow pine and the cypress panels from the fence and from the test. The Committee advised that all future tests be made on white pine, as it is obviously unfair to use anything but the highest grade wood for a paint test in which the desire is to determine the comparative wearing value of pigments. NOTE.--Recent tests have shown that Cypress may be successfully painted when the priming coat of paint is thinned with Benzol (Solvent Naphtha). [Illustration: Panels on Atlantic City Fence Two Lower Sets of Panels are painted with Lithopone Paints. Rapid Failure shown] [Illustration: Panels on Atlantic City Fence] [Illustration: Panels on Atlantic City Fence Two Lower Sets of Panels are Painted with Combination Pigment Paints. Excellent Results shown] =Paints Containing Lithopone.= One of the most striking exhibitions of paint disintegration in the whole test was the failure of nearly all the lithopone formulas tested. At the time these formulas were suggested for the test, various European technical journals had advocated the use of lithopone in large percentage for paints to be used on exterior surfaces. Good results had been obtained in the northwestern section of Europe, with this pigment in certain mixtures, and the object of these lithopone tests at Atlantic City and Pittsburg was to determine whether satisfactory paints could be made of this pigment for exposure in this country. Failure of the tests, however, in nearly every case except where zinc oxide and whiting were mixed with the lithopone, indicated that pigments such as zinc and whiting are necessary in order to prevent the decomposition of lithopone pigment paints. The decay of lithopone paints after they are applied seems to start with rapid oxidation of the linseed oil, and this oxidation seems to continue in a progressive and even accelerated way; after six months' exposure the surface of the paint being chalked to a great extent and showing rapid decomposition of the binder or vehicle. Inasmuch as lithopone is really an inert pigment, this rapid decomposition of its vehicle cannot be explained in the same way as the decomposition of the vehicle of pure white lead paints, where the alkaline nature of the lead is probably responsible for the formation of easily destroyed compounds. As complete failure had taken place in nearly every case where lithopone had been used, it was decided to condemn the lithopone panels on the fence, consisting of formulas 21 to 27, including panels 151 to 164 in white, panels 131 to 144 in yellow, and 109 to 122 in gray. These lithopone tests were later on replaced by new tests in 1909, which will be reported upon later in this book. =General Results.= From these tests, the inspectors reached the unanimous conclusion that a paint made from any mixture of more than one white opaque pigment, either when used alone or in combination with small percentages of inert pigments, is far superior to any one single pigment paint. It was found that the straight white lead paints failed in every case, and this failure was so marked as to make it a conclusive demonstration of the unfitness of white lead along the Atlantic coast, when used without other pigments. Paints made with large percentages of white lead, however, gave excellent results. Gypsum was found unsafe to use in any large proportion in a paint, because of its solubility and liability to percolate through the coating of linoxyn or dried film, thus destroying the surface of the paint. Whiting, or calcium carbonate, demonstrated that it could be used in moderate percentage with some efficiency, but it was evident that any great excess of this pigment must also be avoided on account of its tendency towards rapid chalking. Magnesium silicate, aluminum silicate, and silica are three inert pigments which proved to be of great value in strengthening and reinforcing paints, especially when they were used in small percentage. In the same way, black fixe and barytes, or barium sulphate, also appeared to be useful in strengthening a paint. As these two last named pigments are chemically the same but physically different, the use of both in a paint formula is considered advantageous, because of the differences in size and form of their particles. =Color Tests.= It was the unanimous conclusion of all the inspectors that panels of all formulas which were tinted either gray or yellow were showing far superior wear and less chalking and checking than those which were painted in plain white. The reinforcing action of the tinting materials must be credited for this lengthening of the wear of such paints. Formulas 5, 6, 9, and 16, for instance, in the gray, were in most excellent condition, and in these formulas were used ochre, umber, bone-black, carbon-black, Venetian red and other inert bases. On the yellow panels, formulas 5, 6, 9, and 16 were also in very superior condition, and in these formulas chrome yellow and inert pigments were also used. Some of the color tests included the priming of boards with white lead, zinc oxide, sublimed white lead, lithopone, and other single pigment paints. Over these priming coats was placed a high grade brilliant paranitraniline red. Fairly good results were obtained in every case, but especially when lithopone or zinc oxide was used as a priming base. These pigments seemed to have no effect upon the constitution of the para red. Prussian blue, a colored pigment largely used, but one liable to react with certain paint pigments, was admixed with various paints applied to certain panels. This color was found in some cases to have faded materially, especially when mixed with alkaline pigments such as white lead. Sublimed white lead and zinc oxide, which are more inert in nature, did not have such action on Prussian blue, and the tinted bases of these pigments stood up in a remarkable manner. The greens which were tested were all in very good condition, with absence of fading, and showing only slight mildew. =Condensed Results of Inspection.= The results of inspection as obtained by the fence committee[20] having in charge the inspection of the test, have been condensed into table form, and are presented on pages 130-131. [20] R. S. Perry, Director Scientific Section, Paint Manufacturers' Association of the U. S.; George Butler, Official Painter, representing Master House Painters' & Decorators' Association, H. A. Gardner, Asst. Director. =Second Annual Inspection of the Atlantic City Test Fence.= After the original paints which had been applied to the Atlantic City Fence had been exposed for over two years, another inspection was made by a committee representing the Master Painters' Association of Philadelphia and the Scientific Section of the Paint Manufacturers' Association of the United States. A digest of the report of this committee[21] follows: [21] George Butler, Official Painter Atlantic City Test Fence, representing Philadelphia Master Painters' Association; Charles Macnichol, Master Painter; Henry A. Gardner, Director Scientific Section, Paint Manufacturers' Association of the U. S. "The painted panels were all carefully inspected by the inspectors in the usual manner. With the aid of high-power magnifying glasses, checking was determined. The degree of chalking exhibited by the various paints was ascertained by rubbing a piece of black cloth across the surface of each paint. Close observance was made to determine scaling, peeling, cracking, gloss, color, and the other factors to be considered when examining a painted surface. From these observations it was possible for the inspectors to state whether a panel exhibited general good condition, general fair condition, or general poor condition. CHART OF RESULTS--FIRST INSPECTION--ATLANTIC CITY TEST FENCE ==============================+=================================+ Formula | INERT PIGMENTS | No. |---------------------------------| |Carbonate |Calcium | |Lead |Carbonate | | |Zinc | |Calcium | | |Oxide | |Sulphate | | | |Sublimed | | |Magnesium | | | |White | | |Silicate | | | |Lead | | | |Barium | | | | |Zinc | | | |Sulphate | | | | |Lead | | | | |Silica | | | | |White | | | | | |Blanc| | | | | | | | | | |Fixe | --+------+------+------+------+-----+-----+-----+----+----+-----+ | % | % | % | % | % | % | % | % | % | % | 1| 30.0 | 70.0 | | | | | | | | | 2| 50.0 | 50.0 | | | | | | | | | 3| 20.0 | 50.0 | 20.0 | |10.0 | | | | | | 4| 48.5 | 48.5 | | | 3.0 | | | | | | 5| 22.0 | 50.0 | | | 2.0 | |26.0 | | | | 6| | 64.0 | | | | | |36.0| | | 7| 37.0 | 63.0 | | | | | | | | | 8| 38.0 | 48.0 | | | | | | |14.0| | 9| | 73.0 | | | | | 2.0 | |25.0| | 10| 44.0 | 46.0 | | | 5.0 | | 5.0 | | | | 11| 50.0 | 50.0 | | | | | | | | | 12| 60.0 | 34.0 | | | 6% Inert Pigments | 13| | 27.0 | 60.0 | | 3.0 | |10.0 | | | | 14| 25.0 | 25.0 | 20.0 | | 5.0 |25.0 | | | | | 15| 20.0 | 40.0 | | 30.0 |10.0 | | | | | | 16| 33.0 | 33.0 | | | | | |34.0| | | 17| 40.0 | 40.0 | | | | | 3.0 |13.0| | 4.0 | 18| 75.0 | 25.0 | | | | | | | | | 19| | 25.0 | 75.0 | | | | | | | | 20| 67.0 | 19.5 | | |10.0 | | 3.5 | | | | 33| 15.0 | 30.0 | 25.0 | | | | | |30.0| | 34| 38.95| 33.58| 4.81| |19.48| | 3.18| | | | 35| 37.51| 25.87| 7.84| |20.36| | 8.42| | | | 36|100.0 | | | | | | | | | | 37|100.0 | | | | | | | | | | 38|100.0 | | | | | | | | | | 39| | | |100.0 | | | | | | | 40| | |100.0 | | | | | | | | 45| |100.0 | | | | | | | | | 46| | 61.0 | | | | | |39.0| | | 47| |100.0 | | | | | | | | | ==+======+======+======+======+=====+=====+=====+====+====+=====+ ======================+==========+======+=========+======+ Formula |Panel |Hiding|Color |Hard- | No. |No. |Power | | ness | |First | |Condi-| | | | |Coat | | tion | | | | | |Second | | | | | | | |Coat | | | | | | | | |Third | | | | | | | | |Coat | | | | | | | | | |Aver-| | | | | | | | | | age | | | | | | --+---+----+----+-----+---+------+------+---------+------+ | | | | | | | | | | 1|610| 987| 664| 754| 1|Good |Good |Excellent| 8 | 2|913|1066| 948| 976| 3|Good |Good |Good | 5 | 3|912| 914| 786| 871| 5|Good |Fair |Good | 4 | 4|759| 939|1047| 915| 7|Good |Good |Good | 5 | 5|714|1000| 709| 808| 9|Good |Weak |Good | 8-1/2| 6|928|1189| 863| 993| 11|Fairly|Weak |Good | 8 | | | | | | |Good | | | | 7|763| 972| 891| 875| 13|Good |Good |Off Color| 7 | 8|786| 910| 767| 821| 15|Good |Good |Good | 8-1/2| 9|716|1081| 812| 870| 17|Fair |Poor |Good | 9 | 10|861|1014| 862| 912| 19|Good |Fair |Good | 5 | 11|822| 959| 918| 900| 21|Good |Good |Excellent| 7-1/2| 12|862| 965| 734| 854| 23|Good |Medium|Good | 4 | 13|916|1031|1121| 1073| 25|Good |Good |Good | 4 | 14|564| 806| 785| 718| 27|Bad |Medium|Good | 5 | 15|935|1044|1359| 1113| 29|Good |Medium|Good | 8-1/2| 16|799| 903| 994| 899| 31|Fair |Fair |Good | 7-1/2| 17|806|1016| 884| 902| 33|Good |Fair |Good | 4 | 18|788|1257| 973| 1006|145|Good |Good |Excellent| 3 | 19|700|1183|1400| 1094|147|Good |Good |Excellent| 2 | 20|776|1063| 877| 905|149|Good |Good |Good | 5 | 33|512| 836| 689| 679|176| |Fair | | | 34|523| 800| 810| 711|175|Good |Medium|Good | 4 | 35|450| 893| 724| 689|180|Good |Good |Good | 4 | 36|408| 711| 861| 660|181|Bad |Good |Good | 1 | 37|524|1065| 828| 806|182|Bad |Good |Good | 1 | 38|555| 888| 794| 746|177|Bad |Good |Good | 1 | 39|550| 941| 916| 802|178|Good |Fair |Good | 6 | 40|643| 810| 998| 817|168|Good |Good |Good | 2 | 45|850| | | |170|Fair |Fair |Good | 9 | 46|783| | | |169|Fair |Good |Good | 9 | 47|730| | | |172| |Good |Good |10 | ==+===+====+====+=====+===+======+======+=========+======+ ==============+===========+===========+=============================== Formula | | | No. | | | |Checking |Chalking |Gloss |Remarks --+-----------+-----------+-----------+------------------------------- | | | | 1| |Very Slight|High |Like rubbed varnish work. 2|Hard Matt |Moderate |Med. High | 3| |Medium |Slight | 4| |Very Slight|Med. High | 5| |Slight |High |Hard surface. 6|Matt | |Good |Surface rough. 7| |Slight |High | 8| |Slight |High | 9|Heavy Matt |Medium |High |Peeling started. 10| |Some | Med. High | 11|Med. Matt |Some |Med. High |Some washing and discoloration. 12|Heavy Matt |Bad |Medium | 13| |Medium |Fair | 14|Evident |Some |Medium |Dead, spongy, surface. White | | | |incrustations. 15|Coarse Matt|Slight |High | 16|Bad |Slight |Good |White incrustations. 17| |Some |Fair | 18|Hard Matt |Moderate |Medium | 19|Hard Matt |Slight |Very Little| 20| |Very Little|Medium | 33| | |Good |Rough surface. 34|Evident |Slight |Egg Shell | 35|Matt | |Egg Shell | 36|Very |Bad |Egg Shell |Same as 177, but |Apparent | | |checking not so bad. 37|Very |Bad |Egg Shell |Same as 177 but wood |Apparent | | |shows more plainly. 38|Bad |Bad |Egg Shell |Cracking and perishing evident. 39| |Some |Good | 40| |Consider- |Egg Shell | | |able | | 45|Very Evi- | |High | |dent | | | 46|Some | |Good | 47|Apparent | |Good |Indication of scaling. ==+===========+===========+===========+=============================== "An inspection of the white lead paints on the fence indicated in every instance a rough, chalked, and disintegrated surface that seemed to be well worn, in some cases nearly to the wood. The strongly oxidizing air of the seacoast is probably responsible for the early decay of this pigment. "It was observed that the combination type of paint showed better hiding power than white lead, over the black crosses placed on the priming coat of each panel, as a hiding power test. [Illustration: Front of Fence showing Present Rearrangement of Panels] TESTS INAUGURATED IN 1907 CHART OF RESULTS OF SECOND ANNUAL INSPECTION OF ATLANTIC CITY TEST FENCE, MAY, 1910 =========================================================+ FORMULAS | --+------------------------+-----------------------------+ F | | INERT PIGMENTS | o | +-----------------------------+ r |Basic Carbonate |Calcium | m |White Lead |Carbonate | u | |Zinc Oxide | |Calcium | l | | |Basic | |Sulphate | a | | |Sulphate | | |Magnesium | | | |White Lead| | |Silicate | N | | | |Zinc | | | |Barium | u | | | |Lead | | | |Sulphate | m | | | |White| | | | |Silica | b | | | --+ | | | | | |Blanc| e | | | | | | | | | | Fixe| r | | | | | | | | | --+ | --+------+------+------+---+-----+--+----+-----+-----+---+ | % | % | % | %| % | %| % | % | % | %| 1| 30 | 70 | -- | --| -- |--|-- |-- |-- | --| 2| 50 | 50 | -- | --| -- |--|-- |-- |-- | --| 3| 20 | 50 | 20 | --|10 |--|-- |-- |-- | --| 4| 48.5 | 48.5 | -- | --| 3.0 |--|-- |-- |-- | --| 5| 22 | 50 | -- | --| 2 |--|26 |-- |-- | --| 6| -- | 64 | -- | --| -- |--|-- |36 |-- | --| 7| 37 | 63 | -- | --| -- |--|-- |-- |-- | --| 8| 38 | 48 | -- | --| -- |--|-- |-- |14 | --| 9| -- | 73 | -- | --| 2 |--|-- |-- |25 | --| 10| 44 | 46 | -- | --| 5 |--| 5 |-- |-- | --| 11| 50 | 50 | -- | --| -- |--|-- |-- |-- | --| 12| 60 | 34 | -- | --| -- | 6% Inert Pigment | --| 13| -- | 27 | 60 | --| 3 |--|10 |-- |-- | --| 14| 25 | 25 | 20 | --| 5 |25|-- |-- |-- | --| 15| 20 | 40 | -- | 30|10 |--|-- |-- |-- | --| 16| 33 | 33 | -- | --| -- |--|-- |34 |-- | --| 17| 40 | 40 | -- | --| -- |--| 3 |13 |-- | 4| 18| 75 | 25 | -- | --| -- |--|-- |-- |-- | --| 19| -- | 25 | 75 | --| -- |--|-- |-- |-- | --| 20| 67.0 | 19.5 | -- | --|10.0 |--| 3.5|-- |-- | --| 33| 15 | 30 | 25 | --| -- |--|-- |-- |30 | --| 34| 38.95| 33.58| 4.81| --|19.48|--|-- | 1.59| 1.59| --| 35| 37.51| 25.87| 7.84| --|20.36|--|-- | 4.21| 4.21| --| 36|100 | -- | -- | --|-- |--|-- |-- |-- | --| 37|100 | -- | -- | --|-- |--|-- |-- |-- | --| 38|100 | -- | -- | --| -- |--|-- |-- |-- | --| 39| -- | -- | -- |100| -- |--|-- |-- |-- | --| 40| -- | -- |100 | --| -- |--|-- |-- |-- | --| 45| -- | 90 | -- | --|10 |--|-- |-- |-- | --| 46| -- | 61 | -- | --| -- |--|-- |39 |-- | --| 47| -- |100 | -- | --| -- |--|-- |-- |-- | --| ==+======+======+======+===+=====+==+====+=====+=====+===+ ==+========================================+=== F | | o | | r | | P m | | a u | | n l | | e a | | l | REPORT OF INSPECTION | N +-----------+------------+------+--------+ N u | | |GENE- | | u m | | |RAL | | m b | | |CON- | | b e | | |DI- | | e r |CHALKING |CHECKING |TION |REMARKS | r --+-----------+------------+------+--------+--- 1|Very slight|Very slight |Good |-- | 1 2|Medium |Slight |Very |-- | 3 | | |good | | 3|Medium |Slight |Good |-- | 5 4|Very slight|Slight |Good |-- | 7 5|Slight |Slight |Good |-- | 9 6|Very slight|Slight |Good |-- | 11 7|Medium |Slight |Good |-- | 13 8|Slight |Very slight |Good |-- | 15 9|Very bad |Deep, with |Poor |-- | 17 | |scaling | | | 10|Heavy |Deep |Medium|-- | 19 11|Medium |Medium |Fair |-- | 21 12|Medium |Deep |Fair |-- | 23 13|Medium |Slight |Very |-- | 25 | | |good | | 14|Medium |Lateral |Fair |-- | 27 15|Slight |Visible with|Poor |-- | 29 | |naked eye | | | 16|Slight |Slight |Good |-- | 31 17|Medium |Slight |Good |-- | 33 18|Medium |Slight |Very |-- |145 | | |good | | 19|Consider- |Deep |Good |-- |147 |able | | | | 20|Medium |Slight |Good |-- |149 33|Medium |Slight |Very |-- |176 | | |good | | 34|Slight |Slight |Good |-- |175 | |lateral | | | 35|Slight |Lateral |Good |-- |180 36|Consider- |Heavy |Fair |Rough |181 |able | | |surface | 37|Consider- |Heavy and |Poor |Rough |182 |able |deep | |surface | 38|More than |Very deep |Poor |-- |177 |Panel no. | | | | |182 | | | | 39|Consider- |Very slight |Good |-- |178 |able | | | | 40|Heavy |Slight |Good |-- |168 45|Slight |Slight |Good |-- |170 46|Slight |Medium |Fair |-- |169 47|None |Very deep |Poor |-- |172 ==+===========+============+======+========+=== "There are no pigments possessing greater hiding properties when first used than white leads, but the lack of hiding power on the white lead panels after two years' exposure was caused by the chalking away of the lead. The superior hiding power of the composite paints was due to the action of the other pigments in these combination paints in preventing the lead from chalking away. "The Committee finds that the addition of a reasonable percentage of zinc oxide to white lead increases its durability and retards its chalking, renders it whiter, and forms a surface that presents a much better repainting condition. The combinations of white lead and zinc oxide on the Atlantic City Test Fence were in general good condition throughout. "Corroded white lead, sublimed white lead, zinc oxide, and zinc lead are the standard white opaque pigments. They were all tested on the Atlantic City Fence and it was found that to use any one alone results in inferior protection to the wood. Barium sulphate, silica, asbestine, china clay, and calcium carbonate are the standard crystalline pigments. In the past, the overloading of paints with these crystalline or inert pigments has been the cause of the prejudice that painters have had against their use. It has been established beyond controversy, however, that the use of these pigments, in moderate percentage, combined with any of the standard opaque white pigments, such as white leads, zinc oxide, etc., undoubtedly results in better service from every standpoint and forms the most satisfactory white paint for general outside use. Some of the most perfect painted surfaces on the fence were those made on the above basis as reference to the charted report will show." CHAPTER IX RESULTS OF PITTSBURG TESTS The First Annual Inspection of the Pittsburg Test Fence took place during May, 1909, a little over one year after the painted panels had been placed in position. The inspectors found that in Pittsburg a heavy deposit of soot had formed on the panels, and they considered it therefore inadvisable to make a detailed report of the inspection until the second year of the exposure. The general results of the Pittsburg inspection as reported by the three committees[22] having supervision over the work, is, however, given herewith. [22] J. H. James, Chairman Test Fence Committee, Carnegie Technical Schools. A. C. Rapp, Chairman Fence Committee, Pittsburg Branch Pennsylvania State Association of Master Painters. R. S. Perry, Director Scientific Section, Paint Manufacturers' Association of the U. S.; H. A. Gardner, Asst. Director. [Illustration: Pittsburg Test Fence] During the inspection of the Pittsburg tests it was decided to condemn the lithopone panels on the fence, which consisted of formulas 21 to 27, including panels 151 to 164 in white, 131 to 144 in yellow, 109 to 122 in gray. Almost complete failure had taken place in every case where lithopone had been used. These lithopone tests were later on replaced by new tests which are described later in this book. "=Wood Most Valuable for Test.= As on the Atlantic City Fence, the white pine panels afforded the best results and gives the best indication of the comparative wearing of the paints and affords no unfair condition, such as other woods might offer, to interfere with the test. "=Condition of Cypress.= Cypress showed inferior conditions, except that it was more pronounced and more discoloration of the panels was noticed on this grade of wood, which seems to be extremely greasy in nature and difficult to properly prime, even when the paint used upon this wood contains a large percentage of volatile diluent. "=Removal of Lithopone Panels.= The Joint Committees confirmed the previous recommendation to remove all the lithopone formulas, and they decided to remove the cypress and the yellow pine panels in every formula except in the white paints. "It was decided to reassemble all the white pine panels and group them together for purposes of comparison, and in place of the panels condemned and removed, to substitute a series of new formulas, to further widen the scope of the tests. "=Ultimate Value of Mixed Paints.= The results of the inspection conclusively show that a mixture of more than one prime white pigment, whether this mixture be alone or in combination with a small percentage of inert pigment, produces a paint far superior to a paint manufactured from one pigment alone. "As a general statement of the comparative wearing of the paints, it might be said that the composite formulas are less advanced toward destruction than the paints made from single pigments such as lithopones, white leads and zinc oxides. It is not to be understood from this statement that it is the opinion of the committee that all of the composite formulas are of equal value or that all of them are to be recommended, but it is meant that the higher types, as evidenced by the appearance of the panels, are in the above relation to the single pigment paints. [Illustration: Panels on Pittsburg Test Fence] "=Lithopone Destroyed Rapidly at Pittsburg.= It was evident some time ago that the formulas containing large percentages of lithopone were rapidly failing, and their appearance was very much the same as those formulas of a similar type at Atlantic City. There seems, however, to be some difference in the way these formulas broke down; those on the Pittsburg Fence having shown the quicker destruction, possibly due to the action of the acid gases in the air upon the paint coating. This further confirms the statement that paint compositions containing such heavy percentages of lithopone and intended for outside use must be designed with relation to the particular uses of the product and to the climate in which they are to be used. It will also be necessary to consider more carefully the vehicle of the paints which are to be made of this pigment. "=Possible Value of Excluding Vehicle for Lithopone.= It was the belief of the committee that much better paints containing lithopone could be designed by varying the percentages of the materials contained in the formulas, and it was suggested that a less penetrable vehicle, made more on the line of a varnish, and not as easily affected as straight linoxyn, should be experimented with in connection with these lithopone formulas. "The success of certain European countries in using lithopone as a pigment, even in a very high percentage, may be due to the use of a special vehicle, and, if it is found in future tests that this material, which has been reported as well suited in Northern European climates, may be benefited and made of service by the addition of special oils and special vehicles, then this test would be of great value to the whole paint trade at large. "Preliminary inspections were made on October 6th and later on December 12th, 1908, and a marked difference was observed at the two inspections in the wearing of the various formulas. "The lapse of the two months between these inspections gave opportunity during which cold weather caused contraction of the paint film which had been previously subjected to the hot summer sun, and caused marked chalking of the white lead formulas. On October 6th this chalking was just commencing, while in the December inspection it was well advanced, and at the annual inspection, had proceeded to such an extent that the pigment had been washed from the panels representing those paints which had started early chalking. "Panel 177, representing Zinc Lead, was found to be extremely dark in color throughout the coating and was more on the order of a grayish tint. It resisted all attempts to wash it down to a white surface. The panel, however, in other respects, was in fairly good condition. "=Condition of Corroded White Lead Panels.= Panel 174, representing Type B Pure Basic Carbonate-White Lead, was very badly perished and discolored, and an examination of the surface showed very bad checking. Long continued washing with a sponge removed a discolored surface and showed but a rather thin coating. Panel 175, representing Type C Pure Basic Carbonate-White Lead, showed most marked checking and was in very much the same condition as 174 and 176. Panel 176, representing Type A Pure Basic Carbonate-White Lead, was in the same condition as the Type B and C Basic Carbonate-White Leads. "=Condition of Sublimed White Lead.= Panel 178, representing Sublimed White Lead (Basic Sulphate-White Lead,) was chalking, and the paint coat was somewhat disintegrated. The chalking present on this formula, however, showed that the disintegration of the paint coat had not taken place for several months after the Basic Carbonate-White Leads. This panel maintained good color, not being acted upon by sulphur gases. "=Blackening of Corroded White Lead.= The black and gray formation on all the Basic Carbonate-White Lead panels was probably due to the action of sulphur gases which are present in the district immediate to Pittsburg, and which may cause the formation of black sulphide of lead. "Possibly a general conclusion from all these panels might be described as a perishing of the paint coating, with the formation of sulphide of lead which to a certain extent protects the coating beneath it, but the perishing has proceeded to such an extent that the unaltered paint coating left is but a slight protection to the wood, being extremely thin. "The committee resolved that the detailed observations of the panels could not be made and that they would not be justified in making detailed comparisons between the various formulas, giving the gloss, hardness, general condition, checking, etc. Precision in this work at such a time was impossible, and it was decided that a further period would have to elapse before such a detailed comparison could be made between the various blended or composite formulas on the fence. "=Report on Colors.= It was resolved that at the next inspection of the Pittsburg Fence, portions of the original samples of the original paints used for the yellows and grays should be on hand, previously painted out on small panels for comparison for the deterioration of the colors on these same panels on the fence. "An examination of the combination formula grays by the committee led to the general conclusion that those grays which did not contain a very large percentage of white lead were superior in their maintenance of tone and tint and general condition to any of the other grays upon the fence. However, the presence of umber, ochre, and red oxide in some of the grays which showed to the best advantage may account for their permanence of tone. Some of these grays were the so-called warm grays and were much darker in tone and tint than the ordinary drab which is generally applied. "The straight pure Basic Carbonate-White Lead paints were not painted out in grays or yellow, the test upon this material being only in white. "On Panels 120 and 126, which represent formulas 6 and 9 respectively, the grays are in most excellent condition, and it will be found, by reference to formulas 6 and 9, that there is an absence of white lead in their composition. These formulas, however, contained a small percentage of umber and ochre. Formulas 5 and 16 contained over 20% White Lead and the gray of these formulas maintained their blue tone very well. These formulas were tinted solely with lampblack. "An inspection of Panel 138, which represents Formula 15, showed good maintenance of color in the gray, and was in much better condition as regards permanence of color than the other grays containing white lead. "A study of the yellow panels on the fence led to the unanimous conclusion that a liberal amount of Basic Carbonate-White Lead seemed to have a beneficial result in preserving the bright tone of the chrome yellow in tints so strong as those used on the fence. It was noted that Panel 108, which represents Formula 28, and in which zinc yellow was used, showed great permanence of tone and tint. Unfortunately this zinc chromate was added to a formula containing a large percentage of lithopone, and the destruction of the lithopone to a great extent affected the value of this test. [Illustration: Whiteness of Sublimed White Lead Darkness of Corroded White Lead On Pittsburg Test Fence] "=Maintenance of Para Reds.= A study of the paranitraniline or azo reds painted over the various pigments as priming coats demonstrated that the reds on this fence are in better condition than the reds at Atlantic City. As is well known, para red is manufactured by precipitation in an acid solution and is best maintained under acid conditions. The acidity of the Pittsburg atmosphere, caused by the large amount of acid gases which are being poured into the air, day in and day out, and which are constantly condensing on the surface of structures, may account for the better preservation of these reds. "It was noted that the para reds which were applied to panels prime coated with white lead seemed to be brightening in color and seemed to be gradually working over toward a lightening which may in the future show a pinkish tint. "=Report on Greens.= The bronze green is in most excellent condition and shows an absence of the mildew appearance which was observed at Atlantic City. "The chrome green is standing up exceedingly well, there being practically no change whatsoever in the color since it was exposed. "=Best Base for Blues.= An inspection of the blues showed that those which gave the greatest permanence and the least amount of fading were applied in combination with either Sublimed White Lead (Basic Sulphate-White Lead), or zinc oxide, while those blues which were applied in combination with Basic Carbonate-White Lead showed marked failure and were completely bleached out, due, of course, to the alkaline nature of the corroded white lead; Prussian blues being transformed by alkalies to a white compound. "=Superior Value of Composite Formulas.= Some of the mixed leads, or so-called graded leads, which are combinations of white leads with other high-grade pigments and containing some inert pigments, were not deteriorated so far as the white lead formulas, and the general conclusion was that they were upward of six months behind the deterioration of the straight white leads, and this was confirmed by the presence of moderate chalking, showing an excellent repainting surface and a better thickness and condition of the paint coating. "The same conclusions which were reached at Atlantic City, as to the best method of shellacking, obtained also on the Pittsburg Fence, namely, that application of the shellac to the wood previous to the first coat is the better method. "=Analysis of Paints.= At the time of the painting of the fence a sample of each paint was placed in small friction top cans, carefully labeled, and sent to the Carnegie Technical Schools' laboratory for analysis. The analyses of these paints were made by members of the Test Fence Committee, representing the schools, and appear in this bulletin. The results obtained conform very closely to the formulas which were applied to the fence, a variance of only one or two per cent. being shown in the amount of the different pigments." =Second Annual Inspection of Pittsburg Test Fence.= The second annual inspection of the Pittsburg Test Fence was made on Thursday, May 7th, 1910. The panels in Pittsburg after having weathered for over two years presented an appearance which allowed the making of a detailed inspection, this having been found impossible during the first annual inspection. The inspection party[23] included those master painters who represented the Pittsburg Master Painters' Association, who were in charge of the application of the paints in 1907, 1908, and 1909, together with the test fence committee from the faculty of the Carnegie Technical Schools, and representatives of the Scientific Section. A summary of the report issued by this committee follows: [23] A. C. Rapp, Chairman, Test Fence Committee, Pittsburg Branch, Master Painters' Association; John Dewar, member Fence Committee, Pittsburg Branch, Pennsylvania State Association of Master Painters; J. H. James, Chairman, Carnegie Technical Schools' Test Fence Committee; John A. Schaeffer, member Test Fence Committee, Carnegie Technical Schools; Henry A. Gardner, Director Scientific Section, Paint Manufacturers' Association of the U. S. "Two of the members of the inspection party have been impressed with the lumber lottery existing in some field tests, which have been conducted, and feel that when the object of a test is to determine the relative value of paints, such tests should be conducted on a standard grade of wood, such as white pine. The use of cypress, pitch pine, and other faulty woods, is often the cause of the failure of a paint, which on good wood would show up well. For this reason, only the white pine panels painted with white paints were considered in the inspection, the yellow pine panels and cypress panels having been thrown out of the test at last year's inspection. "Checking, cracking, and alligatoring on the painted surfaces were determined by using a magnifying glass. The degree of chalking existing was decided upon by using small pieces of black felt cloth, rubbing them against the surface of the panel; the degree of whiteness removed upon the cloth being indicative of the amount of chalking taking place. General condition was decided upon after carefully weighing the opinion of each member of the inspection party, as regards the general characteristics shown by each paint, such as checking, chalking, scaling, condition for repainting, hiding power, etc. The results have been charted and presented in this manner:[24] [24] An endeavor was made to use uniform terms in reporting on each formula. In some cases it was necessary to bring out more forcibly the condition by the insertion of qualifying remarks. [Illustration: Panel on Left Painted with Single Pigment Paint; Panel on Right Painted with Combination Pigment Paint. Photograph taken after Two Years' Exposure on Pittsburg Test Fence] "=Conclusions Reached from the Test.= The primary object of the test made at Pittsburg was to determine whether a combination paint, made of two or more pigments, would be equal or superior to single pigment paints. After one year's exposure, the combination type of paint proved more durable than the single pigment paints. "It was early apparent that the combination type of paints, that is, those paints made of more than one pigment, indicated in most cases very excellent wear, with a minimum of blackness and a general good condition of surface. TESTS INAUGURATED IN 1907 CHART OF RESULTS OF SECOND ANNUAL INSPECTION OF PITTSBURG TEST FENCE, MAY, 1910 =========================================================+ FORMULAS | --+------------------------+-----------------------------+ F | | INERT PIGMENTS | o | +-----------------------------+ r |Basic Carbonate |Calcium | m |Wh. L'd |Carbonate | u | |Zinc Oxide | |Calcium | l | | |Basic | |Sulphate | a | | |Sulphate | | |Magnesium | | | |Wh. L'd | | |Silicate | N | | | |Zinc | | | |Barium | u | | | |Lead | | | |Sulphate | m | | | |White| | | | |Silica | b | | | --+ | | | | | |Blanc| e | | | | | | | | | | Fixe| r | | | | | | | | | --+ | --+------+------+------+---+-----+--+----+-----+-----+---+ | % | % | % | %| % | %| % | % | % | % | 1| 30 | 70 | -- | --|-- |--|-- |-- |-- |-- | 2| 50 | 50 | -- | --|-- |--|-- |-- |-- |-- | 3| 20 | 50 | 20 | --|10 |--|-- |-- |-- |-- | 4| 48.5 | 48.5 | -- | --| 3.0 |--|-- |-- |-- |-- | 5| 22 | 50 | -- | --| 2 |--|26 |-- |-- |-- | 6| -- | 64 | -- | --|-- |--|-- |36 |-- |-- | 7| 37 | 63 | -- | --|-- |--|-- |-- |-- |-- | 8| 38 | 48 | -- | --|-- |--|-- |-- |14 |-- | 9| -- | 73 | -- | --| 2 |--|-- |-- |25 |-- | 10| 44 | 46 | -- | --| 5 |--| 5 |-- |-- |-- | 11| 50 | 50 | -- | --|-- |--|-- |-- |-- |-- | 12| 60 | 34 | -- | --|-- | 6% Inert Pigment | 13| -- | 27 | 60 | --| 3 |--|10 |-- |-- |-- | 14| 25 | 25 | 20 | --| 5 |25|-- |-- |-- |-- | 15| 20 | 40 | -- | 30|10 |--|-- |-- |-- |-- | 16| 33 | 33 | -- | --|-- |--|-- |34 |-- |-- | 17| 40 | 40 | -- | --|-- |--| 3 |13 |-- | 4 | 18| 75 | 25 | -- | --|-- |--|-- |-- |-- |-- | 19| -- | 25 | 75 | --|-- |--|-- |-- |-- |-- | 20| 67.0 | 19.5 | -- | --|10.0 |--| 3.5|-- |-- |-- | 33| 15 | 30 | 25 | --|-- |--|-- |-- |30 |-- | 34| 38.95| 33.58| 4.81| --|19.48|--|-- | 1.59| 1.59|-- | 35| 37.51| 25.87| 7.84| --|20.36|--|-- | 4.21| 4.21|-- | 36|100 | -- | -- | --|-- |--|-- |-- |-- |-- | 37|100 | -- | -- | --|-- |--|-- |-- |-- |-- | 38|100 | -- | -- | --|-- |--|-- |-- |-- |-- | 39| -- | -- | -- |100|-- |--|-- |-- |-- |-- | 40| -- | -- |100 | --|-- |--|-- |-- |-- |-- | 45| -- | 90 |-- | --|10 |--|-- |-- |-- |-- | 46| -- | 61 |-- | --|-- |--|-- |-- |39 |-- | 47| -- |100 |-- | --|-- |--|-- |-- |-- |-- | ==+======+======+======+===+=====+==+====+=====+=====+===+ ==+========================================+=== F | | o | | r | | P m | | a u | | n l | | e a | | l | REPORT OF INSPECTION | N +-----------+------------+------+--------+ N u | | |GENE- | | u m | | |RAL | | m b | | |CON- | | b e | | |DI- | | e r |CHALKING |CHECKING |TION |REMARKS | r --+-----------+------------+------+--------+--- 1|Slight |None |Good |Slight | 2 | | | |scaling;| | | | |fairly | | | | |white | | | | |surface | 2|Medium |Very slight |Fair |Panels | 4 | | | |quite | | | | |dark and| | | | |some | | | | |scaling | 3|Consider- |None |Good |Fairly | 6 |able | | |white | 4|Consider- |Lateral and |Fair |White | 8 |able |irregular | |surface | 5|Medium |Very |Very |Extreme-| 10 | |slight |good |ly white| | | | |surface | 6|Very slight|Very bad; |Poor |Black | 12 | |rough sur- | |surface | | |face | | | 7|Slight |Slight |Good |Medium | 14 | | | |white | | | | |surface | 8|Slight |Slight |Good |White | 16 | | | |surface;| | | | |slight | | | | |scaling | 9|None |Deep; |Very |Film | 18 | |peeling in |poor |brittle | | |places | |and sur-| | | | |face | | | | |dark | 10|Medium |Slight la- |Good |Surface | 20 | |teral in | |very | | |places | |white | 11|Consider- |Deep matt |Fair |Consi- | 22 |able |checking | |derable | | | | |scaling;| | | | |forma- | | | | |tion of | | | | |black | | | | |coating | | | | |shat- | | | | |tered | | | | |off | 12|Medium |Slight |Fairly|Surface | 24 | | |good |white | 13| Medium |None |Excel-|Very | 26 | | |lent |white | 14|Consider- |Medium |Fair |Panel | 28 |able | | |fairly | | | | |white | 15|Slight |Medium |Good |Surface | 30 | | | |quite | | | | |dark | 16|Medium |Very slight |Good |Quite | 32 | | | |white | 17|Consider- |Slight, |Fair |Surface | 34 |able |along | |fairly | | |lateral | |white | | |lines | | | 18|Medium |Slight, with|Good |Surface | 36 | |some scaling| |has be- | | | | |come | | | | |quite | | | | |dark | 19|Consider- |None |Excel-|No black| 38 |able | |lent |coating;| | | | |surface | | | | |very | | | | |white, | | | | |due to | | | | |inert- | | | | |ness of | | | | |pigment | | | | |or pro- | | | | |gressive| | | | |chalking| 20|Medium |Medium |Good | | 40 33|Heavy |None |Fair |White |168 | | | |surface | 34|Consider- |Very slight |Good |Surface |172 |able | | |is very | | | | |white; | | | | |progres-| | | | |sive | | | | |chalking| | | | |may have| | | | |prevent-| | | | |ed for- | | | | |mation | | | | |of black| | | | |coating | 35|Bad |None |Good |Very |173 | | | |white; | | | | |no black| | | | |coating | | | | |evident | 36|Bad |Bad |Fair |Surface |174 | | | |is dead | | | | |black; | | | | |shatter-| | | | |ed in | | | | |places | 37|Extremely |Medium |Fair |Very |175 |bad | | |black | | | | |surface | | | | |and | | | | |mottled | | | | |in | | | | |places | 38|Very bad |Very bad, |Poor |Black |176 |and quite |with scaling| |surface | |dusty | | |is loose| | | | |and | | | | |shatter-| | | | |ed | 39|Consider- |Slight |Good |Panel |177 |able | | |surface | | | | |quite | | | | |white | 40|Very bad |Slight |Good |Surface |178 | | | |very | | | | |white, | | | | |possibly| | | | |due to | | | | |progres-| | | | |sive | | | | |chalking| | | | |or in- | | | | |ertness | | | | |of pig- | | | | |ment | 45|Slight |Considerable|Fair |White |169 | | | |surface | 46|Slight |Slight |Fair |Consi- |170 | | | |derable | | | | |scaling | | | | |present;| | | | |surface | | | | |fairly | | | | |white | 47|Bad |Bad |Bad |Bad con-|171 | | | |dition | | | | |through-| | | | |out | ==+===========+============+======+========+=== [Illustration: Middle white panel is painted with a combination pigment formula Middle white panel is painted with pure Corroded White Lead Notice Difference in Color after Two Years' Wear] "=Recommendation.= On account of the peculiar conditions which obtain in and around Pittsburg, as exemplified by these tests, the committee finds, as a result thereof, that the best white paint for general exterior use is made of white lead combined with zinc oxide and a moderate percentage of inert pigments, such as silica, asbestine, or barytes. "=Some Peculiar Conditions Affecting the Tests.= The inspectors were most impressed during the inspection by the blackness exhibited to such a high degree by certain panels, and the fair degree of whiteness by others. It is well known that in Pittsburg nearly all paints become darkened by the deposition on their surface of carbon particles emanating from the combustion of soft coal. Certain of the paints, however, presented fairly white surfaces, and it would thus appear that the extreme darkness shown by other paints was due to their composition. Corroded white lead when used alone was uniformly covered by black particles, and the higher the percentage of corroded white lead in a paint the darker was the surface. It was at first thought that this darkness was due to the softness of the white lead pigment or to its roughened surface, in causing adherence of soot particles. Sublimed white lead, however, which is also a soft pigment, chalked even more progressively than corroded white lead, but its surface was not rough, and presented a very white appearance. Scrapings from the different panels are being taken, and after a careful analysis the findings from the investigations will be reported by a member of the Inspection Committee." A. C. RAPP. _Chairman Test Fence Committee, Pittsburg Branch, Master Painters' Association_ JOHN DEWAR. _Member Fence Committee, Pittsburg Branch, Penna. State Association of Master Painters_ J. H. JAMES. _Chairman Carnegie Technical Schools' Fence Committee_ J. A. SCHAEFFER. _Instructor in Chemical Practice, Carnegie Technical Schools Pittsburg, Pa._ H. A. GARDNER. _Director Scientific Section, Paint Mfrs. Asso. of U. S._ _May 31, 1910_ PITTSBURG TEST FENCE COMPARATIVE SPREADING RATES OF WHITE PAINT ON WHITE PINE PANELS _Average Spreading Rate 266 Square Feet_ =======+===========+===========+===========+==========+============== Formula|First Coat |Second Coat|Third Coat | Average |Spreading Rate Number | (sq. ft.) |(sq. feet) | (sq. ft.) |Spreading | Rate | | | | Rate | 3-Coat Work | | | |(sq. feet)| (sq. feet) -------+-----------+-----------+-----------+----------+-------------- 1 | 759 | 1020 | 768 | 849 | 283 2 | 694 | 975 | 1229 | 966 | 322 3 | 743 | 873 | 770 | 795 | 265 4 | 537 | 987 | 1019 | 848 | 283 5 | 509 | 896 | 886 | 764 | 255 6 | 765 | 1045 | 994 | 935 | 312 7 | 734 | 922 | 996 | 884 | 295 8 | 565 | 862 | 854 | 760 | 253 9 | 622 | 926 | 1160 | 903 | 301 10 | 610 | 1013 | 1070 | 900 | 300 11 | 651 | 933 | 1010 | 865 | 288 12 | 675 | 1027 | 623 | 775 | 258 13 | 663 | 892 | 981 | 845 | 282 14 | 498 | 785 | 807 | 697 | 232 15 | 688 | 1000 | 984 | 891 | 297 16 | 669 | 880 | 860 | 803 | 268 17 | 635 | 982 | 1077 | 900 | 300 18 | 636 | 959 | 1031 | 875 | 292 19 | 626 | 1076 | 1037 | 913 | 304 20 | 591 | 1015 | 929 | 845 | 282 21 | 595 | 948 | 910 | 818 | 273 22 | 617 | 868 | 810 | 765 | 255 23 | 549 | 1002 | 986 | 846 | 282 24 | 539 | 918 | 783 | 747 | 249 25 | 530 | 929 | 850 | 770 | 257 26 | 532 | 916 | 1011 | 820 | 273 27 | 520 | 850 | 656 | 675 | 225 33 | 600 | 1340 | 810 | 917 | 306 34 | 471 | 743 | 690 | 635 | 212 35 | 402 | 598 | 645 | 548 | 183 36 | 398 | 668 | 838 | 635 | 212 37 | 579 | 653 | 838 | 690 | 230 38 | 463 | 615 | 704 | 594 | 198 39 | 474 | 954 | 849 | 759 | 253 40 | 446 | 815 | 871 | 711 | 237 45 | 527 | 841 | 916 | 761 | 254 46 | 605 | 740 | 818 | 721 | 240 47 | 735 | 961 | 993 | 896 | 299 =======+===========+===========+===========+==========+============== CHAPTER X A LABORATORY STUDY OF TEST PANELS =Panel Sections for Laboratory Test.= In order to make a laboratory study of the painted panels on the Atlantic City and Pittsburg fences, it was thought advisable to remove small sections from representative areas and transfer them to the laboratory for such work. The fences were visited by the official inspection committees soon after the first annual inspection, and the panels were carefully looked over. Upon each was marked out a representative portion, care being exercised to select areas where previous inspections had not disturbed the surface of the film in any manner. The inspectors then placed the number of the panel upon the areas which had been marked off, as well as their initials. The marked sections were sawed out, wrapped in tissue paper, and then transferred to the laboratory where they were placed upon models of the respective fences from which they had been removed. The illustration shows the model test fences set up together. It is very apparent that the Pittsburg panels are much the darker in color, due to the soot, and in some cases lead sulphide formed upon their surfaces. This difference was undoubtedly due to the atmospheric conditions prevailing where the tests were made. One would be led to suppose that a paint film exposed to an atmosphere such as is found in Pittsburg would show deterioration more rapidly than one exposed in Atlantic City. In all the tests and experiments, however, the Atlantic City panels appeared broken down to a much greater extent; though it is true that the Pittsburg panels had darkened considerably and presented a rather mottled appearance. The deposit of soot on the Pittsburg panel seemed to act as a preservative coating for the film beneath, and prevented marked disintegration. [Illustration: Sections of Atlantic City and Pittsburg Fences Arranged for Laboratory Examination] [Illustration: Sections of Atlantic City and Pittsburg Fences] [Illustration: Upper set of tests made on Panels from Atlantic City Fence Lower set of tests made on Panels from Pittsburg Fence Figures at left indicate Formula Number Figures at right indicate Degree of Chalking] [Illustration: Color Standard used in Comparison of Panel Section] =Chalking Test.= Small strips of black felt, about one inch square, were firmly attached to a block of wood, and by a clamp having the same pressure in each case, the wood with its surface of black felt was fixed to the panel. This apparatus, which resembles a blackboard eraser, is firmly drawn across the panel in one direction for a certain definite distance, during which time it gathers all the chalked surface presented by the painted wood. Upon detaching the apparatus from the panel it is observed that the black cloth becomes whitened to an extent proportionate to the chalking that has taken place on the given area. After each one of the panels had been treated in the same manner by the same operator, the black cloths were assembled on one large board and photographed. A definite standard of chalking was made up, and the operator was enabled to put down opposite the report on each panel the degree of chalking which had taken place, No. 1 representing the least amount and No. 10 the greatest amount of chalking. =Degree of Whiteness Shown by Panels.= It was a very simple matter to gauge the whiteness of the various panels, by comparing them with a series of standard boards painted with three coats of white paint. Florence Brand, New Jersey zinc oxide, was used as the standard for whiteness and termed "No. 1." In making "No. 2" standard, to the zinc oxide was added .01% of lampblack. By adding .02% of lampblack to the zinc, standard "No. 3" was obtained, and so on, increasing the amount of lampblack in each case by .01%. These standards were run up to "No. 30," and the various panels on the different fences compared with them. The degrees of whiteness are recorded in progressive numbers, No. 1 being the standard for whiteness and No. 30 the darkest. The Atlantic City panels ranged from 3 to 8 in the scale of whiteness, while the Pittsburg panels required the use of the entire range of standards. =Resistance to Abrasion.= The apparatus used for determining the abrasion resistance of a paint was made of a glass tube about six feet long, having an internal bore of 7/8 inch. This was supported in an upright position over a dish which held the panel under test at an angle of 45 degrees. The abrasive material consisted of No. 00 emery, which was dropped into the tube through a funnel having a bore of 5 mm. When the emery reached the bottom of the long tube it scattered itself so as to strike a surface on the panel about an inch in diameter. The emery was constantly poured in until the paint coating had worn away, showing the bare wood. The weight in pounds of emery powder required to show the disruption of the coating is recorded and reported as the measure of the "abrasion resist." The panel requiring the greatest weight of emery to cause abrasion is evidently the most resistant to abrasion. Paint is often subjected to serious abrasion, through the blowing of sand, especially at the seashore, and to withstand such action should contain a proportion of pigments especially resistant to abrasion, such as silica, zinc oxide, asbestine, and barytes. [Illustration: Apparatus for Determining the Abrasion Resistance of Paints] [Illustration: Formula No. 1, A. C.] [Illustration: Formula No. 2, A. C.] [Illustration: Formula No. 3, A. C.] [Illustration: Formula No. 4, A. C.] [Illustration: Formula No. 5, A. C.] [Illustration: Formula No. 6, A. C.] NOTE: The author wishes to acknowledge the assistance of Dr. J. A. Schaeffer in the preparation of the photomicrographs herewith shown. [Illustration: Formula No. 7, A. C.] [Illustration: Formula No. 8, A. C.] [Illustration: Formula No. 9, A. C.] [Illustration: Formula No. 10, A. C.] [Illustration: Formula No. 11, A. C.] [Illustration: Formula No. 12, A. C.] [Illustration: Formula No. 13, A. C.] [Illustration: Formula No. 14, A. C.] [Illustration: Formula No. 15, A. C.] [Illustration: Formula No. 16, A. C.] [Illustration: Formula No. 17, A. C.] [Illustration: Formula No. 18, A. C.] [Illustration: Formula No. 19, A. C.] [Illustration: Formula No. 20, A. C.] [Illustration: Formula No. 33, A. C.] [Illustration: Formula No. 34, A. C.] [Illustration: Formula No. 35, A. C.] [Illustration: Formula No. 36, A. C.] [Illustration: Formula No. 37, A. C.] [Illustration: Formula No. 38, A. C.] [Illustration: Formula No. 39, A. C.] [Illustration: Formula No. 40, A. C.] [Illustration: Formula No. 45, A. C.] [Illustration: Formula No. 46, A. C.] [Illustration: Formula No. 47, A. C.] =Making Photomicrographs.= The photomicrographs which are herewith shown were made in the following manner: A part of a panel was placed upon the stage of the microscope and held firmly in place with clips. By varying the adjustment and carefully running over the field the condition of the surface was readily given, using the same eye-piece and objective throughout the tests, and obtaining a magnification of thirty-three. Great care was exercised to secure an average field showing the general and typical appearance of every panel. Little difficulty was experienced in so doing, as the laboratory panels gave very representative surfaces of the large panels on the fence. The instrument was then inclined horizontally and the eye-piece was fitted into the camera nose. In the back of the bellows of the camera was placed the ground glass for focusing. To secure illumination the light from an electric arc lamp was reflected from a mirror directly upon the painted surface of the panel, which in turn was reflected through the camera on to the ground glass. The plate-holder was then put in position and six-second exposures were made, afterward developing and printing. =Checking and Cracking.= What was termed "fine matt checking" at the First Annual Inspection was not visible at the time to certain members of the Inspection Committee, but it is an established fact that the checking was an existing condition, as the photomicrographs have shown. This checking has a very peculiar characteristic in that the lines are very narrow and hair-like, being somewhat interlaced and peculiarly forked. That this hair matt checking is a preliminary condition which afterwards develops into matt checking and into marked or heavy checking seems to be indicated. It appears from an examination of the photomicrographs of the paint films that a paint coating closely resembles the surface of the earth, and is subject to the same basic laws that have caused the various geodetic changes in the earth's crust. Observation of a dried pond or lake bed will disclose types of fissuring and cracking similar to those shown by dried paint coatings in which the oil has been fully oxidized, and especially in the case of paints containing pigments which act upon the oil to produce compounds brittle in nature. At Atlantic City the panels were all clean and free from dirt, presenting continuous exposure of the films, and thus maintaining conditions for active checking. At Pittsburg, soon after the panels began to chalk, the large amount of dust and black soot in the atmosphere completely covered the panels with a very thick, resistant coating of carbon, which acted as a seal or protector, preventing disintegration to a great extent. This coating was extremely hard to remove, and photomicrographs, before and after removal of this coating by rubbing with a damp cloth, failed to reveal marked checking on any of the formulas except those made of strictly pure basic carbonate-white lead. The checking, even on these, was not as marked as at Atlantic City. It is presumed that after the chalking had taken place and the chalked pigment had been washed from the panels, the gradually increasing coat of carbon and lead sulphide had protected the panels from checking, or possibly the atmosphere of Pittsburg, which in other respects had deteriorated the panels to a greater extent than at Atlantic City, did not have the extreme action in causing checking that the Atlantic City atmosphere seemed to have effected. [Illustration: Combination Formula No. 1, Pittsburg BEFORE WASHING Mottled surface due to external coating of impurities.] [Illustration: AFTER WASHING] [Illustration: Formula No. 4, Pittsburg BEFORE WASHING] [Illustration: AFTER WASHING] [Illustration: Formula No. 38, Pittsburg Basic Carbonate--White Lead Panels on Fence BEFORE WASHING Checking evident even through the outer covering of foreign matter.] [Illustration: AFTER WASHING] [Illustration: Formula No. 36, Pittsburg Basic Carbonate--White Lead Panels on Fence BEFORE WASHING Peculiar network-like checking appearing through outer coat of impurities.] [Illustration: AFTER WASHING] [Illustration: Formula No. 40, Pittsburg] [Illustration: Formula No. 45, Pittsburg] =Results on Combination Pigment Paints.= It will be noticed that the checking on most of the combination pigment paints made of lead, zinc, and inert pigments, was moderate, and in many cases of a fine order. It has been observed that the percentage of zinc oxide in a paint is not always a criterion upon which future checking may be judged. Nor could it be said that the checking is dependent upon the percentage of basic carbonate-white lead added to the paint. However, it appears that scientific blending of the various pigments, with regard to their physical properties in oil, such as their strength and elastic limit, develops the greatest resistance to both cracking and checking. Elasticity is vital, but strength must be combined therewith in order to prevent disruptions of the paint coating. Paint films made of certain inert pigments, when tested on the filmometer, were relatively high in strength, but relatively low in elasticity. Such pigments, when used in large percentage, form coatings which are hard and apt to crack. The use, however, of these pigments in moderate percentages seems very beneficial in overcoming the effect of using an excessive percentage of white lead, or of zinc oxide. =Results on White Lead Paints.= The maximum checking was observed on the basic carbonate-white lead panels, the size of the checks in some cases being several times larger than those on the other panels. On some of the basic carbonate-white leads the checking was of a very peculiar nature, consisting of very broad fissures in the paint coating, disclosing the wood surfaces beneath. The type of checking existing was also distinct in its structure, being hexagonal in shape. One of the most marked features shown by the basic carbonate-white lead films was the extreme roughness of their surfaces. This roughness is most likely due to the excessive chalking which had taken place. =Results on Silica and Barytes Paints.= The checking of paints very high in silica resolved itself into fine hair-like lines which are generally lateral to each other, and indicate a cracked appearance. The checking of paints containing very high percentages of barytes was also of a distinct nature, being generally forked in appearance and of no definite striation. =Surface Condition of Fume Pigment Paints.= The panels painted with basic sulphate-white lead (sublimed white lead) showed complete absence of checking. This was also true of the panels painted with zinc lead. These are both fume products and are extremely fine in their physical size, which may account for this condition. Although zinc oxide is made in a similar manner, it gives a much harder paint coating than either of the afore-mentioned pigments, and presents a surface which develops considerable checking, generally of a medium order. The past theories regarding zinc oxide, in which it has been maintained that zinc oxide gives the maximum checking, are evidently incorrect, as the checking found on the zinc oxide panels was not as marked or deep as the checking on the basic carbonate-white lead panels; in fact, the checking might be more in the line of a cracking, possibly due to the brittle nature of the coating composed of straight zinc. This is especially true of zinc paints containing insufficient oil. =The Importance of the Physical Nature of Pigments.= It appears that very fine grinding of materials, chosen for their characteristic fineness, with the absence of any unfavorable physical condition or chemical sensitiveness, are important factors in the making of a paint to resist cracking or checking. The purity of the essential materials, as well as the scientific compounding of these materials, with due regard to the law of minimum voids, are great factors which enhance the qualities of paints, greater, perhaps, than the variation of percentages of the various pigments which go to make up a paint. CHAPTER XI ADDITIONAL TESTS AT ATLANTIC CITY AND PITTSBURG A series of new test panels to take the place of those panels which were condemned and subsequently removed from the Atlantic City and Pittsburg fences, were painted and exposed during June, 1909. These new test panels are of white pine, this wood having been selected by the joint inspection committee as offering the best condition for future tests. The method used in painting these panels was the same as in the previous tests, together with the adoption of certain refinements in the reductions, application, etc. Thirty-six formulas were selected with careful regard to the percentage of components, including several paints containing lithopone combined with whiting and zinc oxide,[25] two pigments which gave promise of supporting the lithopone for outside use. Some of these lithopone paints contained special vehicles which it was thought would prevent the destructive action which lithopone seems to have upon linseed oil. In order to obtain a criterion of the value of the new formulas applied, as against the wearing of straight white leads, the original white leads used in the previous tests were included, and other brands were added. Each formula was painted out in white, yellow, and gray, upon panels of white pine wood arranged in sequence upon the fence, and properly identified. The customary opacity test, in the form of a small black square, was stencilled over the priming coat of each panel, as in the former tests. The composition of the vehicle in all the new tests was standard, using pure linseed oil with a small percentage of turpentine drier. The tints used in each formula were secured at the time of application by the use of standard colors, lampblack, and medium chrome yellow, using an approximate amount for each formula. [25] A brief study of the theory of solutions (See Cushman and Gardner on "Corrosion and Preservation of Iron and Steel"), involving the modes of iron formation, will be invaluable to the student who is inquiring into the cause of the peculiar fogging of lithopone, with the idea in view of correcting this evil by physical or chemical treatment. Inasmuch as our observations thus far have led us to believe that the fogging of lithopone takes place in the presence of moisture, with the contributory and necessary action of chemically active rays from the sun or other source, it is fair to assume that under these conditions the insoluble molecule of zinc sulphide and barium sulphate reverts by intricate molecular disturbance and ionization back to the soluble barium sulphide and zinc sulphate from which the lithopone is formed by metathesis. If this be true, then the acid nature of these soluble salts is no doubt combated and overcome at the moment of formation by the basic nature of zinc oxide and calcium carbonate, which tend to ionize to an alkaline reaction. The value of zinc oxide and calcium carbonate in lithopone paints as detergents of blackness, has been demonstrated at both Atlantic City and Pittsburg." H. A. G. [Illustration: Section of Fence Showing New Panels Recently Placed] [Illustration: Appearance of 1909 Tests] An inspection of these new tests was made during June, 1910, and the results of the inspection are shown on pages 178 to 181. The results of the inspection prove that it is unsafe to use lithopone in a paint containing white lead of any type, early darkening and failure being shown in every case where such a combination existed. The formulas in the new test, which were properly balanced and which had a low percentage of lithopone combined with zinc oxide and whiting, presented in some cases very good surfaces. A rough, sandy surface, however, was shown where lithopone was used in any great quantity. TESTS INAUGURATED IN 1909 RESULTS OF INSPECTION OF ATLANTIC CITY TEST FENCE, MAY, 1910 ===============================================+ FORMULAS | --+-----------------------+--------------------+ F | | | o | | | r |Basic Carbonate | | m |White Lead | | u | |Zinc Oxide | | l | | |Basic Sulphate | | a | | |White Lead | INERT PIGMENTS | | | | |Precipi- +--------------------+ N | | | |tated |Calcium Carbonate | u | | | |White Lead | |Silica | m | | | | |Zinc | | |Asbestine | b | | | | |Lead | | | |China Clay| e | | | | | |Li- | | | | |Barytes| r | | | | | |tho-| | | | | |Blanc| | | | | | -pone| | | | | +-Fixe| --+----+--+---+---+---+---+--+---+--+--+--+----+ | % | %| %| %| %| %| %| %| %| %| %| % | 1| -- |--| 45| --| --| 40|15| --|--|--|--| -- | 2| -- |--| 45| --| --| 40|--| 15|--|--|--| -- | 3| -- |45| --| --| --| 45|10| --|--|--|--| -- | 4| -- |--| 45| --| --| 45|10| --|--|--|--| -- | 5| -- |40| --| --| --| 40|20| --|--|--|--| -- | 6| -- |--| 45| --| --| 35|--| --|20|--|--| -- | 7| 50 |--| --| --| 36| --|--| --| 2| 8| 4| -- | 8| -- |--| 50| --| --| 36|--| --| 2| 8| 4| -- | 9| -- |--| 50| --| --| 36|--| --| 2|--|12| -- | 10| -- |36| 50| --| --| --|--| --| 2| 8| 4| -- | 11| 28 |55| --| --| --| --|--| --| 3|--| 7| 7 | 12| -- |55| 28| --| --| --|--| --| 3|--| 7| 7 | 13| -- |60| --| --| --| 30|10| --|--|--|--| -- | 14| -- |30| 30| --| --| 30|10| --|--|--|--| -- | 15| -- |--| 60| --| --| 30|--| --|10|--|--| -- | 16| -- |--| --| --| --|100|--| --|--|--|--| -- | 17| -- |--| --| --| --|100|--| --|--|--|--| -- | 18| 33 |33| --| --| --| --|--| 17|--|17|--| -- | 19| 34 |33| --| --| --| --|--| 33|--|--|--| -- | 20| 34 |33| --| --| --| --|--| --|--|33|--| -- | 21|100 |--| --| --| --| --|--| --|--|--|--| -- | |[26]| | | | | | | | | | | | 22|100 |--| --| --| --| --|--| --|--|--|--| -- | 23|100 |--| --| --| --| --|--| --|--|--|--| -- | 24| -- |--|100| --| --| --|--| --|--|--|--| -- | 25| -- |--| --| --|100| --|--| --|--|--|--| -- | 26| -- |--| --|100| --| --|--| --|--|--|--| -- | 27|100 |--| --| --| --| --|--| --|--|--|--| -- | 28|100 |--| --| --| --| --|--| --|--|--|--| -- | 29| 24 |45| 13| --| --| --|--| --|18|--|--| -- | 30| 45 |--| --| --| --| 40|15| --|--|--|--| -- | 31| 45 |--| --| --| --| 40|--| 15|--|--|--| -- | 32| 45 |--| --| --| --| 35|--| --|20|--|--| -- | 33| 50 |--| --| --| --| 36|--| --| 2|--|12| -- | 34| 75 |--| 25| --| --| --|--| --|--|--|--| -- | 35| 50 |--| 50| --| --| --|--| --|--|--|--| -- | 36| -- |--| --| --| --| --|--|100|--|--|--| -- | ==+====+==+===+===+===+===+==+===+==+==+==+====+ [26] This pigment on analysis proved to be zinc lead. ==+===============================================+== F | | o | | r | | P m | | a u | | n l | | e a | | l | | N | | N u | | u m | REPORT OF INSPECTION | m b |---------+---------+----------------+----------+ b e |CHALKING |CHECKING |GENERAL |REMARKS | e r | | |CONDITION | | r --+---------+---------+----------------+----------+-- 1|None |None |Rough surface, | | 1 | | |but fair for re-| | | | |painting | | 2|None |None |Fair; rough sur-| | 2 | | |face and slight-| | | | |ly dark | | 3|Very |Very |Good; very white| | 3 |slight |slight |surface | | 4|None |None |Rough surface | | 4 | | |and slightly | | | | |dark | | 5|Very |Very |Good; very white| | 5 |slight |slight |surface | | 6|None |None |Rough surface; | | 6 | | |dark | | 7|None |Very |Good | | 7 | |slight | | | | |lateral | | | | |checking | | | 8|Heavy |Slight |Excellent; very | | 8 | | |white | | 9|Heavy |Some |Excellent; very | | 9 | | |white | | 10|None |Slight |Good | |10 11|None |Slight |Good; slightly | |11 | | |dark | | 12|None |Slight |Good | |12 | |lateral | | | 13|Very |Consider-|Fair | |13 |slight |able | | | | |lateral | | | | |running | | | | |along | | | | |grain of | | | | |wood | | | 14|Very |Consider-|Fair | |14 |slight |able | | | | |lateral | | | | |running | | | | |along | | | | |grain of | | | | |wood | | | 15|Heavy |Slight |Fair | |15 | |lateral | | | | |checking | | | 16|Heavy |Consider-|Dark color; | |16 | |able |rough surface | | 17|Consider-|Medium |Better than No. | |17 |able | |16; not as rough| | | | |or dark | | 18|Very |None |Good | |18 |slight | | | | 19|Very |Slight |Good | |19 |slight | | | | 20|Very |None |Good | |20 |slight | | | | 21|Slight |Slight |Fair; rough | |21 | | |surface | | 22|Very |Lateral |Fairly good | |22 |slight |cracking | | | 23|Medium |Lateral |Fair | |23 | |cracking | | | 24|Slight |Slight |Good for | |24 | |cracking |repainting | | 25|Medium |None |Good surface | |25 26|Heavy |Slight |Fair; surface | |26 | |cracking |rough & dark | | 27|Heavy |Lateral |Fair | |27 | |cracking | | | 28|Medium |Consider-|Poor; very | |28 | |able |rough, dark | | | | |surface | | 29|Slight |None |Good | |29 30|Heavy |Heavy |Poor | |30 | |checking | | | | |and alli-| | | | |gatoring | | | 31|None |Alliga- |Rough surface; | |31 | |toring |dark | | 32|Slight |Medium |Dark and rough | |32 | | |surface | | 33|Consider-|Slight |Poor; dark | |33 |able | |surface | | 34|None |None |Fair; dark | |34 | | |surface | | 35|None |Slight |Fair; rough | |35 | | |surface | | 36|Extremely|Medium |Fair |Vehicle |36 |bad | | |disinte- | | | | |grated; | | | | |spotted in| | | | |places | ==+=========+=========+================+==========+== TESTS INAUGURATED IN 1909 RESULTS OF INSPECTION OF PITTSBURG TEST FENCE, MAY, 1910 ===============================================+ FORMULAS | --+-----------------------+--------------------+ F | | | o | | | r |Basic Carbonate | | m |White Lead | | u | |Zinc Oxide | | l | | |Basic Sulphate | | a | | |White Lead | INERT PIGMENT | | | | |Precipi- +--------------------+ N | | | |tated |Calcium Carbonate | u | | | |White Lead | |Silica | m | | | | |Zinc | | |Asbestine | b | | | | |Lead | | | |China Clay| e | | | | | |Li- | | | | |Barytes| r | | | | | |tho-| | | | | |Blanc| | | | | | -pone| | | | | --Fixe| --+----+--+---+---+---+---+--+---+--+--+--+----+ | % | %| %| %| %| %| %| %| %| %| %| % | 1| -- |--| 45| --| --| 40|15| --|--|--|--| -- | 2| -- |--| 45| --| --| 40|--| 15|--|--|--| -- | 3| -- |45| --| --| --| 45|10| --|--|--|--| -- | 4| -- |--| 45| --| --| 45|10| --|--|--|--| -- | 5| -- |40| --| --| --| 40|20| --|--|--|--| -- | 6| -- |--| 45| --| --| 35|--| --|20|--|--| -- | 7| 50 |--| --| --| 36| --|--| --| 2| 8| 4| -- | 8| -- |--| 50| --| --| 36|--| --| 2| 8| 4| -- | 9| -- |--| 50| --| --| 36|--| --| 2|--|12| -- | 10| -- |36| 50| --| --| --|--| --| 2| 8| 4| -- | 11| 28 |55| --| --| --| --|--| --| 3|--| 7| 7 | 12| -- |55| 28| --| --| --|--| --| 3|--| 7| 7 | 13| -- |60| --| --| --| 30|10| --|--|--|--| -- | 14| -- |30| 30| --| --| 30|10| --|--|--|--| -- | 15| -- |--| 60| --| --| 30|--| --|10|--|--| -- | 16| -- |--| --| --| --|100|--| --|--|--|--| -- | 17| -- |--| --| --| --|100|--| --|--|--|--| -- | 18| 33 |33| --| --| --| --|--| 17|--|17|--| -- | 19| 34 |33| --| --| --| --|--| 33|--|--|--| -- | 20| 34 |33| --| --| --| --|--| --|--|33|--| -- | 21|100 |--| --| --| --| --|--| --|--|--|--| -- | 22|100 |--| --| --| --| --|--| --|--|--|--| -- | |[27]| | | | | | | | | | | | 23|100 |--| --| --| --| --|--| --|--|--|--| -- | 24| -- |--|100| --| --| --|--| --|--|--|--| -- | 25| -- |--| --| --|100| --|--| --|--|--|--| -- | 26| -- |--| --|100| --| --|--| --|--|--|--| -- | 27|100 |--| --| --| --| --|--| --|--|--|--| -- | 28|100 |--| --| --| --| --|--| --|--|--|--| -- | 29| 24 |45| 13| --| --| --|--| --|18|--|--| -- | 30| 45 |--| --| --| --| 40|15| --|--|--|--| -- | 31| 45 |--| --| --| --| 40|--| 15|--|--|--| -- | 32| 45 |--| --| --| --| 35|--| --|20|--|--| -- | 33| 50 |--| --| --| --| 36|--| --| 2|--|12| -- | 34| 75 |--| 25| --| --| --|--| --|--|--|--| -- | 35| 50 |--| 50| --| --| --|--| --|--|--|--| -- | 36| -- |--| --| --| --| --|--|100|--|--|--| -- | ==+====+==+===+===+===+===+==+===+==+==+==+====+ [27] This pigment on analysis proved to be zinc lead. ==+===============================================+== F | | o | | r | | P m | | a u | | n l | | e a | | l | | N | | n u | | u m | REPORT OF INSPECTION | m b +---------+---------+----------------+----------+ b e |CHALKING |CHECKING |GENERAL |REMARKS | e r | | |CONDITION | | r --+---------+---------+----------------+----------+-- | | | | | 1|Consider-|Slight |Fair |Dark in | 1 |able | | |places. | | | | |Diffused | 2|Slight |Bad |Fair |Dark in | 2 | | | |places | 3|Medium |None |Good |Darkening | 3 | | | |shown in | | | | |places | 4|Consider-|None |Good |Medium | 4 |able | | |dark | 5|Slight |None |Good |No exces- | 5 | | | |sive dark-| | | | |ness | 6|Medium |Slight |Good |Surface | 6 | | | |fairly | | | | |white | 7|Medium |None |Excellent |Whitest | 7 | | | |surface of| | | | |new tests | 8|Extremely|Slight |Fair |Surface | 8 |bad | | |darkening | 9|Extremely|Slight |Fair |Not as bad| 9 |bad | | |as No. 8 | 10|Slight |None |Good |Excellent |10 | | | |surface; | | | | |very white| 11|Slight |None |Excellent |Surface |11 | | | |fairly | | | | |white; | | | | |thin soot | 12|Medium |None |Good |Surface |12 | | | |white | 13|Medium |Very bad |Fair |Slight |13 | |in spots | |darkening | 14|Heavy |Consider-|Fair |Slight |14 | |able | |darkening | 15|Extremely|Slight |Fair |Fairly |15 |bad | | |white | 16|Extremely|Advanced |Bad |Surface |16 |bad |and deep | |rough with| | | | |consider- | | | | |able dis- | | | | |integra- | | | | |tion and | | | | |much dark-| | | | |ness | 17|Not as |Less ad- |Fair |Not as |17 |bad as |vanced | |dark as | |No. 16 |than No. | |No. 16; | | |16 | |slightly | | | | |mottled in| | | | |places; | | | | |buff color| 18|Very |Practi- |Fair |Surface |18 |slight |cally | |white | | |none | | | 19|Very |None |Good |Surface |19 |slight | | |fairly | | | | |white | 20|None |None |Good |Surface |20 | | | |fairly | | | | |white | 21|Slight |Slight |Fair |Surface |21 | | | |very rough| | | | |and dark | 22|Medium |Slight |Fair |Surface |22 | | | |fairly | | | | |white | 23|Slight |Bad |Fair |Surface |23 | | | |rough and | | | | |darkest on| | | | |fence | 24|Bad |None |Good |Surface |24 | | | |white | 25|Slight |None |Good |Fairly |25 | | | |white | | | | |surface | 26|Medium |Slight |Fair |Rough and |26 | | | |very dark;| | | | |chalking | | | | |is dis- | | | | |rupting | | | | |black | | | | |coating | 27|Medium |Slight |Good |Surface |27 | | | |fairly | | | | |white | 28|Medium |Deep; |Poor |Surface |28 | |evident | |rough and | | |without | |very dark | | |glass | | | 29|Slight |Slight |Good |Very white|29 | | | |surface | 30|None |Slight |Fair |Color dark|30 31|Very |Advanced |Fair |Color very|31 |slight | | |dark | 32|Extremely|Consider-|Fair |Color very|32 |slight |able | |dark; | | | | |rough | | | | |surface | 33|Extremely|Slight |Fair |Surface |33 |slight | | |dark and | | | | |rough | 34|Slight |Deep |Fair |Surface |34 | | | |medium | | | | |dark | 35|Consider-|Slight |Fair |Surface |35 |able | | |medium | | | | |dark | 36|Extremely|None |Fair |Vehicle |36 |bad | | |disinte- | | | | |grated, | | | | |leaving | | | | |very | | | | |white, | | | | |chalked | | | | |surface of| | | | |pigment | ==+=========+=========+================+==========+== CHAPTER XII NORTH DAKOTA PAINT TESTS An inspection of the original test fence, erected and painted by the North Dakota Agricultural College, on the grounds of the agricultural Experiment Station at Fargo, was made by the inspection committee[28] representing the Paint Manufacturers' Association of the United States, on the 19th and 20th of November, 1909. The fence was erected in 1906 and painted with commercial paints, procured in the open market. The east side of the fence was built of soft pine and cedar weather-boarding, such as is almost universally used on houses in that locality, presenting a very good surface for test purposes, while the west side was built largely of flat trimmed boards of hard pitch pine which, unfortunately, contained knots, pitch pockets, and uneven surfaces, causing to a greater or lesser extent cracking, scaling, and bad general results on all paints applied thereto. [28] Henry A. Gardner, Director Scientific Section, Educational Bureau, Paint Manufacturers' Association of U. S.; George Butler, Master Painter; Charles Macnichol, Master Painter. The fences built in 1907 and 1908 at the suggestion of the Paint Manufacturers' Association, were inspected on the 20th, 21st, and 22nd of November, 1909, and the detailed results of the inspection of all these fences follow in this report. The same general conclusions as to the woods represented in the 1906 fence also apply to the 1907 and 1908 fences, and because of the general bad quality of wood used on the western exposure of all fences, the detailed reports were made only from an examination of the eastern side of the fences, both on cedar and soft pine. The following general summary of the inspection and its results applies to all the test fences on the grounds of the college and is the unanimous conclusion drawn by the inspectors from this work: [Illustration: North Dakota Test Fences] [Illustration: Typical Sample of Hard Pine Trim Board Showing Knot and Sappy Grain] [Illustration: Test No. 13--1906 Fence Complete Disintegration and Failure of Cheap Paint] "Non-absorbent woods, difficult to penetrate, such as those on the west side of the fences, would undoubtedly have given much better results had they been painted with paints properly reduced to suit the nature of the wood. This treatment seems to have been overlooked in the North Dakota tests, and the painting of the hard pine boards was done with the same consistency of mixtures and the same reductions as upon soft pine. Scaling of course resulted. One of the chief purposes of the fences, however, was to study the different types of wood, and compliance with this desire resulted in the bad conditions herein noted. It has been shown in many other field tests that adherence of paints to hard wood surfaces can be obtained only by causing the priming coat to become amalgamated with the woody fibre, by the use of a large percentage of volatile diluent turpentine, benzole, asphaltum spirits, etc., to secure penetration. If such treatment is omitted, failure soon results, as was evidenced by the uniformly bad conditions presented by the paints on the hard pine panels. [Illustration: Pine Weatherboarding Showing Knots and Grain] [Illustration: Condition of Lumber Affecting Paint, West Side 1906 Fence] [Illustration: Hail-stone Abrasions on House Repainting Tests] [Illustration: Hail-stone Effect, West Side of 1907 Test Fence] "During July, 1908, a violent hailstorm occurred in Fargo, and left its impression on nearly every wooden structure; in many cases deep dents being made into the wood. The west side of the test fences, which received the most injury from this storm, was covered with these dents over almost its entire surface, causing cracks in the form of concentric rings to appear on the abraded paint coatings. The bad condition of the wood, improper method of applying priming coat, combined with the hailstorm effect on the painted surfaces on the west side of the fences, were undoubtedly responsible for the universal failure of the paints thereon, and, for these reasons, the west side was eliminated from the detailed inspection, only general observations of these tests being made. These general observations, however, showed that paints Nos. 6 and 8 on the 1906 fence, and paints Nos. 8, 10, and 13 on the 1907 fence, proved the most satisfactory on the western exposure.[29] [29] These formulas were the same as those respectively numbered on the Atlantic City and Pittsburg fences. [Illustration: Peculiar Crystallization Effect on Section 41. New Special Fence Paint Applied During Cold Weather] "Ochre was tried out as a priming coat on several formulas, but it was found to be most unsatisfactory, affecting the subsequent coats of paint and causing early failure, as evidenced by broad checking, discoloration, and general bad condition. These conditions also apply to those panels on the 1908 fence coated with shellac as a primer. "The colored formulas in every case showed a great superiority over the same paints in white untinted, and demonstrated that a percentage of color has a wonderful influence on the preservation of the paint coating, reducing chalking, checking, and general disintegration. This condition is probably due to the reinforcing value of the color pigments used. "It is safe to state that the combination formulas tinted yellow were of better appearance than the corroded white leads tinted yellow, the latter appearing quite dark in many cases. "The wearing of the paints made solely from white lead and zinc oxide seemed to indicate that a percentage of a third pigment, of an inert nature, would have been beneficial. "The high-type mixtures of pigments containing lead and zinc, with moderate percentages of inert pigments, on good wood, were in most excellent general condition; in fact, much superior to the single pigment paints. Their surface exhibited only minor checking and moderate chalking with good maintenance of color, and presenting surfaces well adapted to repainting. "The sublimed white lead was in fair condition, with very little checking, and offering a fair repainting surface. The corroded white lead was somewhat whiter than the sublimed white lead, but a careful observation of the surface of the corroded lead revealed deep checking. "It was clearly demonstrated, however, that in climates of the North Dakota type, white lead alone is not entirely satisfactory. The addition of zinc oxide to white lead forms paint that has proved much superior to the white lead alone. "It was conclusively demonstrated that mixtures of white lead and zinc oxide, properly blended with moderate percentages of reinforcing pigments, such as asbestine, barytes, silica and calcium carbonate, are most satisfactory from every standpoint, and are superior to mixtures of prime white pigments not reinforced with inert pigments. "The white leads painted out on the 1908 fence exhibited different degrees of checking, the mild-process lead and sublimed white lead which presented the best surfaces, being free from checking, while the old-process leads seemed to show very deep and marked checking, even after one year's wear. [Illustration: Corroded White Lead Sublimed White Lead Condition of Two White Leads on Two Grades of Wood] [Illustration: Photomicrographic Apparatus and Method of Use] CONDENSED REPORT OF INSPECTION OF "1906" TEST FENCE FARGO, N. D., NOV. 19-23, 1909 _No gloss shown by any of the paints. Formulas in white on white pine only included here, on east side of fence_ ==+=========================================================================++ T| FORMULAS || e+--------------------------------------------+----------------------------++ s| PIGMENT | VEHICLE || t+--------------------------------------------+----------------------------++ |Corroded |Linseed Oil || N|White Lead | |Turp. and Drier || o| |Sublimed | | |Japan Drier || .| |White Lead | | | |Water || | | |Zinc Oxide | | | | |Benzine || | | | |Calcium | | | | |Drier || | | | |Carbonate | | | | | |Vola-|| | | | | |Silica and | | | | | |tile || | | | | |Silicates | | | | | |Oil || | | | | | |Barium Sulphate | | | | | | || | | | | | | |Magnesium | | | | | | || | | | | | | |Silicate | | | | | | || | | | | | | | |Clay and | | | | | | || | | | | | | | |Silica | | | | | | || | | | | | | | | |Bary-| | | | | | || | | | | | | | | |tes | | | | | | || | | | | | | | | |and | | | | | | || | | | | | | | | |Sili-| | | | | | || | | | | | | | | |cate | | | | | | || --+-----+-----+----+----+---+----+---+---+-----+----+----+--+----+----+-----++ | % | % | % | % | %| % | %| %| % | % | % | %| % | % | % || 1|100 | -- | -- | -- | --| -- | --| --| -- | -- | -- |--| -- | -- | -- || 2| -- |100 | -- | -- | --| -- | --| --| -- | -- | -- |--| -- | -- | -- || 3| 50 | -- |50 | -- | --| -- | --| --| -- |90 |10 |--| -- | -- | -- || 4| -- | 60 |40 | -- | --| -- | --| --| -- |90 | -- |10| -- | -- | -- || 5| 28.7| -- |71.3| -- | --| -- | --| --| -- |93 | 7 |--| -- | -- | -- || 6| 40.2| -- |50.3| 4.1|5.4| -- | --| --| -- |90.7| 9.3|--| -- | -- | -- || 7| 21.9| 21.9|45.8|10.4| --| -- | --| --| -- |89.6| 9.7|--| 0.7| -- | -- || 8| 44.1| -- |46.0| 4.6| --| -- |5.3| --| -- |86.0|12.6|--| 1.4| -- | -- || 9| In gray only No report. || 10| 13.9| -- |34.9|26.8| --| -- | --| --| 24.4|72.2| -- |--|24.0| 3.8| -- || 11| 55.0| -- |15.2| -- | --| -- | --| --| 29.8| Test not finished || 12| -- | 5.1|25.0| -- | --| -- | --| --| 69.9| -- | -- |--| -- | -- | -- || 13| -- | -- |31.3|45.4| --|22.8| --|0.5| -- |57.2| -- |--|16.1|26.7| -- || 14| 34.8| 5.4|59.2| -- | --| -- | --| --| -- |86.0|13.7|--| 0.3| -- | -- || 15| -- | -- |64 | -- | --|36 | --| --| -- |98 | -- |--| -- | -- | 2 || ==+=====+=====+====+====+===+====+===+===+=====+====+====+==+====+====+=====++ ==+============================================== | REPORT OF CONDITION +--------+-----------+-------+-------+--------- T| | | | | e| | | | | s| | | | | t| | | | | | | | | | N| | | | |CONDITION o|CHALKING|CHECKING |HIDING |COLOR |FOR RE- .| | |POWER | |PAINTING --+--------+-----------+-------+-------+--------- 1|Very bad|Extremely |Good |Good |Only fair | |deep | | | 2|Bad |Very slight|Good |Light |Fair | | | |yellow-| | | | |ish | | | | |tint | 3|Medium |Fine matt--|Good |Fair |Fair to | |deep in | | |good | |places | | | 4|Medium |Surface |Good |Good |Fair | |checking, | | | | |very slight| | | 5|Slight |Quite deep |Medium |Good |Poor. | | | | |Coating | | | | |wrinkled | | | | |and hard 6|Medium |Slight |Good |Good |Good | |surface | | | | |checking | | | 7|Medium |Surface |Fair |Good |Slight | |checking | | |shelling | |with slight| | |from wood | |cracking | | | 8|Medium |Very slight| Good |Good |Good 9| | | | | 10|Slight |Very bad | Bad condition throughout. 11| | | | | 12|Medium |Medium |Defici-|Good |Shelling | | |ent | |from wood 13| Worst looking surface in North Dakota tests. 14|Medium |Slight |Fair |Good |Good | |surface | | | | |checking | | | | |and peeling| | | 15|Slight |Lateral |Good |Good |Hard film | |cracking | | | | |quite deep | | | ==+========+===========+=======+=======+========= CONDENSED REPORT OF INSPECTION OF "1907" TEST FENCE FARGO, NORTH DAKOTA, NOV. 19-23, 1909 ===+========================================================================== T | FORMULAS e +-------------------------------------------+------------------------------ s | PIGMENT | VEHICLE t +-------------------------------------------+------------------------------ |Corroded White Lead |Linseed Oil N | |Sublimed White Lead | |Turpentine o | | |Zinc Oxide | |Drier . | | | |Calcium Carbonate | | |Turpentine | | | | |Aluminum and | | |and | | | | |Magnesium Silicate | | |Japan | | | | | |Barytes | | | |Water | | | | | | |Silica | | | | |Turpentine | | | | | | | |Inert | | | | |and Benzine | | | | | | | | |Magnesium | | | | |Japan Drier | | | | | | | | |Silicate | | | | | |Drier | | | | | | | | | |Calcium| | | | | | |Vola- | | | | | | | | | |Sul- | | | | | | |tile | | | | | | | | | |phate | | | | | | |Oil | | | | | | | | | | |Zinc| | | | | | | |[B] | | | | | | | | | | |Lead| | | | | | | | ---+----+---+----+---+--+--+----+--+---+--+----+----+----+--+----+--+--+--+--- 1| 30 | --|70 |-- |--|--| -- |--|-- |--| -- |93 | 7 |--| -- |--|--|--|-- 2| 50 | --|50 |-- |--|--| -- |--|-- |--| -- |86 | -- |10| 4 |--|--|--|-- 3| 20 | 20|50 |10 |--|--| -- |--|-- |--| -- |90 | -- |--| -- |10|--|--|-- 4|48.5| --|48.5| 3 |--|--| -- |--|-- |--| -- |83 | -- |--| -- |17|--|--|-- 5| 22 | --|50 | 2 |26|--| -- |--|-- |--| -- |90 | -- |--| -- |--|10|--|-- 6| -- | --|64 |-- |--|36| -- |--|-- |--| -- |98 | -- |--| -- |--|--| 2|-- 7| 37 | --|63 |-- |--|--| -- |--|-- |--| -- |85 |13 |--| 2 |--|--|--|-- 8| 38 | --|48 |-- |--|--|14 |--|-- |--| -- |91 | 9 |--| -- |--|--|--|-- 9| -- | --|73 | 2 |--|--|25 |--|-- |--| -- |66 |-- |--|12 |22|--|--|-- 10| 44 | --|46 | 5 |--|--| -- |--|-- |--| -- |86.0|12.5|--| 1.5|--|--|--|-- 11| 50 | --|50 |-- |--|--| -- |--| 5 |--| -- |78 |22 |--| -- |--|--|--|-- 12| 60 | --|34 |-- |--|--| -- | 6|-- |--| -- |91 | 7 |--| 2 |--|--|--|-- 13| -- | 60|27 | 3 |--|--| -- |--|10 |--| -- |90 | -- |--| -- |--|10|--|-- 14| 25 | 20|25 | 5 |--|--| -- |--|-- |25| -- |90 | -- | 6| -- |--|--|--| 4 15| -- | 20|40 |10 |--|--| -- |--|-- |--| 30 |90 | -- | 8| 2 |--|--|--|-- 16| 33 | --|33 |-- |--|34| -- |--|-- |--| -- |90 | -- |10| -- |--|--|--|-- 17|100 |(Type A)|-- |--|--| -- |--|-- |--| -- | -- | -- |--| -- |--|--|--|-- 18|100 |( " B)|-- |--|--| -- |--|-- |--| -- | -- | -- |--| -- |--|--|--|-- 19|100 |( " C)|-- |--|--| -- |--|-- |--| -- | 10 gal. oil |--|--|--|-- | | | | | | | | | | | reduction | | | | 20| -- |100| -- |-- |--|--| -- |--|-- |--| -- | -- | -- |--| -- |--|--|--|-- 21| -- | --|100 |-- |--|--| -- |--|-- |--| -- | -- | -- |--| -- |--|--|--|-- 22| -- | --| -- |-- |--|--| -- |--|-- |--|100 | -- | -- |--| -- |--|--|--|-- 23|100 |(Type C)|-- |--|--| -- |--|-- |--| -- | 5-1/2 gal. oil reduction for | | | | | | | | | | | | priming 24| 37.|7. |25. |20.|--|--|8.42| (Michigan Seal | -- |--| -- |--|--|--|-- | 51 |84 |87 |36 | | | | White Lead) | | | | | | | 25| 38.|4. |33. |19.|--|--|3.18|(Railway White| -- | -- |--| -- |--|--|--|-- | 95 |81 |58 |48 | | | | Lead) | | | | | | | | 200|15. | --|-- | 1.|--|--| -- |--| 1.|--|43. |32. | 4. |--| 1. |--|--|--|-- |625 | | |875| | | | |250| |750 |250 |000 | |250 | | | | ===+====+===+====+===+==+==+====+==+===+==+===+====+=====+==+====+==+==+==+=== [B] = Benzine ===+=========+========================================= T | | REPORT OF CONDITION e | +------------+------+------+-------------- s | | | | | t | | | | | | | | | | N | | | | | o | | | | | . | | | | | |CHALKING |CHECKING |HIDING|COLOR |CONDITION FOR | | |POWER | |REPAINTING ---+---------+------------+------+------+-------------- 1|Medium |Considerable|Fair |Fair |Poor surface; | |with lateral| | |too hard | |cracking | | | 2|Medium |Considerable|Good |Fair |Rather poor | |with lateral| | | | |cracking | | | 3|Bad |Medium-- |Good |Good |Fair | |scaling some| | | 4|Medium |Considerable|Good |Good |Medium | |with lateral| | | | |cracking | | | 5|Slight |Slight |Good |Good |Good 6|Medium |Considerable|Medium|Medium|Fair 7|Consider-|Present; |Fair |Fair |Poor |able |long cracks | | | 8|Slight |Surface |Good |Good |Fair | |checking | | | 9|Not |Considerable|Medium|Good |Medium |evident |with lateral| | | | |cracking | | | 10|Medium |Very slight |Good |Good |Good 11|Slight |Lateral |Fair |Fair |Fair | |cracking | | | 12|Consider-|Present with|Fair |Fair |Not very good |able |slight | | | | |cracking and| | | | |scaling | | | 13|Medium |Surface |Good |Good |Good | |checking | | | | |only | | | 14|Consider-|Considerable|Medium|Fair |Medium; some |able |with lateral| | |washing shown | |cracking | | | 15|Medium |Medium |Good |Good |Medium 16|Medium |Slight; some|Fair |Good |Medium | |shelling | | | 17|Bad |Alligator- |Good |Fair |Poor | |ing; deep | | | | |checking | | | 18|Bad |Alligator- |Fair |Fair |Poor | |ing; deep | | | | |checking | | | 19|Bad |Deep |Good |Fair |Poor 20|Consider-|Slight |Good |Fair |Fair |able | | | | 21|Not |Consider- |Fair |Good |Poor |evident |able; slight| | | | |cracking; | | | | |scaling | | | 22|Medium |Lateral |Good |Good |Fair | |cracking; | | | | |split | | | 23|Bad |Medium deep |Good |Good |Fair 24|Consider-|Slight; |Fair |Good |Good |able |lateral | | | | |cracking | | | 25|Consider-|Some; |Fair |Good |Excellent |able |lateral | | | | |cracking | | | 200|Medium |Bad cracking|Good |Good |Fair ===+=========+============+======+======+============== "As before stated, the committee believes that a serious mistake was made on the test fence in painting out the leads and other formulas on the various woods without any special attention to reduction to suit the nature of the wood, thus accounting largely for the difference of the wearing of the paints on the different woods. "The reduction of the white leads especially was to be criticised in these tests, in many cases too much oil and not sufficient turpentine being present to cause penetration. "The application of paint to cedar was satisfactory in most all cases, and this wood showed much better results than the other woods upon the fences. The exudation of resinous pitch on the hard pine was extremely serious, in some cases coming through the paint in large streaks, causing bad results. "It is to be regretted that the house repainting tests which were conducted are of no special value, inasmuch as no information is on file as to the composition of the old paints originally on the houses before the application of the test paints. Imperfections in the old coating, such as excessive chalking, deep checking, scaling, rosin exudations, etc., affected the subsequent coats in such a manner as to prevent any knowledge of where the new and old paint troubles began. The committee, therefore, omitted a detailed inspection of such tests. "Examination of the three houses which were painted over new wood showed results which correspond with the results obtained from the fence tests. That is, they showed the ultimate value of high type mixtures of several pigments over one pigment alone. These tests seem to indicate that very good results can be secured from most of the paints sold in North Dakota. If the consumer or householder would exercise more care in the selection of wood and preparation of surfaces, with due regard to the proper reduction for various coats, more satisfactory results would be obtained. "From an examination of certain paints on the 1908 fence containing petroleum spirits, it would appear that this paint thinner is of value, and in the face of conditions such as are presented by the present scarcity of turpentine, the use of petroleum spirits in moderate quantity would be justified." NORTH DAKOTA TESTS [Illustration: 1. Formula No. 21, Section 31, on 1907 Fence] [Illustration: 2. Section 80, on 1908 Fence] [Illustration: 3. Formula No. 6, Section 9, on 1907 Fence] [Illustration: 4. Formula No. 2, Section 3, on 1907 Fence] [Illustration: 5. Formula No. 1, Section 1, on 1907 Fence] [Illustration: 6. Formula No. 14, Section 21, on 1907 Fence] [Illustration: 7. Formula No. 13, Panel 19, on 1907 Fence] [Illustration: 8. Formula No. 19, Panel 28. Broad, Deep Checking on Corroded White Lead on 1907 Fence] [Illustration: 9. Formula No. 24, Panel 36, on 1907 Fence. Good Condition. Surface Checking Only] [Illustration: 10. Formula No. 25, Section 37, on 1907 Fence. Good Condition. Surface Checking Only] [Illustration: 11. Formula No. 8, Panel 12, on 1907 Fence] [Illustration: 12. Formula No. 10, Panel 15, on 1907 Fence] [Illustration: 13. Panel No. 34, Formula 23, on 1907 Fence. Deep Checking on Corroded White Lead] [Illustration: 14. Test No. 13 on 1906 Fence. White Spots Show Paint Left on Wood. Balance of Paint Split and Disintegrated from Surface] [Illustration: 15. Test No. 6 on 1906 Fence. Surface Checking Only] [Illustration: 16. Test No. 2, 1906 Fence. Sublimed White Lead] [Illustration: 17. Cracks in Test No. 15 on 1906 Fence] [Illustration: 18. Effect of Cracking on Hard Pine, Causing Splitting of Painting Coating] [Illustration: 19. Formula No. 22, Section 23, 1907 Fence. Cracks in Paint Coating, Caused by Cracks in Wood; Coating Otherwise in Good Condition] [Illustration: 20. Test No. 8, on 1906 Fence. Surface Checking Only] [Illustration: 21. Combination Cracking and Checking on Section 69, on 1908 Fence] [Illustration: 22. Cracks in Paint Coating, Caused by Cracking of Hard Pine Wood] [Illustration: 23. Section 65 on 1908 Fence. Showing Early Breakdown of Corroded White Lead] CHAPTER XIII TENNESSEE PAINT TESTS =Location and Object of Tests.= On September 15, 1910, the erection of a wooden test fence was completed on the State Fair Grounds at Nashville, Tenn. Upon this fence were exposed forty-two samples of white paint, the object of the test being to determine whether the combination type of formula is superior to the single pigment type in the southern plateau, of which Nashville is the centre. =Construction of Tests.= The construction and outline of these tests differ somewhat from those conducted at Atlantic City and elsewhere by the Scientific Section. The fence frame is 150 feet long, being made of 6-inch bevelled girders supported three feet from the ground by 4-inch posts set six feet apart. Upon this girder were placed a series of forty-two test panels supported at top and bottom with weather strips and braces. The test panels used were 40 inches high, 30 inches wide, and one inch thick, being made of the highest grade white pine, tongued and grooved together, and protected on the edges by weather strips projecting from the surface of the panels. Each panel was painted on both sides with the same paint, thus giving an eastern and western exposure, the fence running north and south. The formulas used in the test vary in their percentage composition, being made up in some cases of single pigments, and again with combinations of the opaque white pigments, with and without certain percentages of the crystalline or inert pigments. The paints were applied under the supervision of prominent master painters and a committee representing the Scientific Section and other technical organizations. Other field tests have shown that the sap and knots in hard-grained woods, such as yellow pine, cypress, etc., have been the cause of the failure of even the best paints, and that all tests should be conducted upon soft woods, such as white pine and poplar, if definite results are to be obtained. Paints tinted with ochre, chrome yellow, lampblack, iron oxide, etc., have shown on the other field tests which have been conducted at Atlantic City, Pittsburg, and Fargo the value of these pigments in giving to the paints increased wearing properties. On the Southern Test Fence, therefore, all the formulas were ground in white only and placed upon white pine so as to make the test primarily one to determine the value of the various white pigments upon good wood. [Illustration: Tennessee Test Fences] =Oil and Thinner Tests.= Upon one series of panels on the fence was placed one of the formulas which had given universal satisfaction on the various test fences in the past, and this formula was made up with various oils other than linseed oil, in order to determine the value of these oils as painting materials. For instance, the vehicle part of the one formula referred to is made up of 50% linseed oil and 50% soya bean oil, and again 50% linseed oil and 50% rosin oil, etc., an effort being made to test out a few of the available semi-drying oils. The same formula referred to was ground in pure linseed oil and subjected to a series of tests where it has been thinned for application as priming and second coats with a series of wood turpentines obtained from the United States Forest Products Laboratory at Madison, Wis. These turpentines were made from southern pine stumps and sawdust, and they vary greatly in their properties. Some were objectionable in odor, while others were of excellent quality, having an odor almost equal to that of pure gum spirits. [Illustration: Views of Fence] One product under test on the Southern Test Fence is pine oil, a high boiling point product obtained from the manufacture of wood turpentine from sawdust. This oil has a boiling point of over 210 degrees Centigrade as against the 150 degrees of ordinary gum spirits. It is almost water white and has the same penetrating qualities as the pure gum spirits; when mixed with 50% linseed oil forming a paint oil of extremely light color, that produces a semi-flat paint of great whiteness. =Reductions and Application.= Formulas No. 1 to No. 37 were all ground in pure refined linseed oil. They were made in the form of semi-paste and then thinned down with sufficient refined linseed oil so that each would have a relative viscosity. To each formula was then added a sufficient amount of pure lead and manganese linoleate drier to give proper drying qualities. On thinning for the priming coat, one pint of turpentine was added to each gallon of paint. For the second coat, one-half pint turpentine and one-half pint refined linseed oil were added to each gallon. For the third coat work, reduction was made with one pint of refined linseed oil. In the case of formulas 31 to 37, reductions were the same, except that a series of specially prepared wood turpentines were used in place of the pure gum spirits used in formulas 1 to 31. Formulas 38 to 41, as will be shown, were ground in equal parts of the oils tested. These formulas, however, were all thinned for application with pure gum spirits of turpentine, and the respective vehicle in which they were ground. No inspection of the Tennessee Test Fence has yet been made. The formulas tested are as follows: FORMULAS FOR SOUTHERN TEST FENCE VEHICLE: _Bleached Linseed Oil with Lead and Manganese Linoleate Drier_. Formula No. 1 [30]Corroded white lead 100% 2 [30]Sublimed white lead 100% 3 Zinc oxide XX 100% 4 Zinc lead white 100% 5 Leaded zinc 65%, corroded white lead 35% 6 [30]Corroded white lead 100% 7 [30]Corroded white lead 100% [30] Corroded White Lead is the Basic Carbonate of Lead. Sublimed White Lead is the Basic Sulphate of Lead. No. 8 Corroded white lead 85% Zinc oxide 15% ---- 100% No. 9 Corroded white lead 65% Zinc oxide 35% ---- 100% No. 10 Corroded white lead 50% Zinc oxide 50% ---- 100% No. 11 Corroded white lead 40% Zinc oxide 60% ---- 100% No. 12 Corroded white lead 30% Zinc oxide 70% ---- 100% No. 13 Corroded white lead 45% Zinc oxide 45% Silica 10% ---- 100% No. 14 Corroded white lead 45% Zinc oxide 45% Asbestine 10% ---- 100% No. 15 Corroded white lead 45% Zinc oxide 45% China clay 10% ---- 100% No. 16 Corroded white lead 45% Zinc oxide 45% Barytes 10% ---- 100% No. 17 Corroded white lead 45% Zinc oxide 40% Silica 15% ---- 100% No. 18 Corroded white lead 45% Zinc oxide 40% Asbestine 15% ---- 100% No. 19 Corroded white lead 45% Zinc oxide 40% Barytes 15% ---- 100% No. 20 Sublimed white lead 45% Zinc oxide 40% Silica 15% ---- 100% No. 21 Sublimed white lead 45% Zinc oxide 40% Asbestine 15% ---- 100% No. 22 Sublimed white lead 45% Zinc oxide 40% Barytes 15% ---- 100% No. 23 Zinc oxide 90% Calcium carbonate 10% ---- 100% No. 24 Sublimed white lead 40% Zinc oxide 45% Calcium carbonate 15% ---- 100% No. 25 Corroded white lead 35% Zinc oxide 50% Silica 15% ---- 100% No. 26 Corroded white lead 20% Sublimed white lead 30% Zinc oxide 40% Asbestine 10% ---- 100% No. 27 Corroded white lead 20% Sublimed white lead 20% Zinc oxide 40% Barytes 10% Asbestine 10% ---- 100% No. 28 Corroded white lead 20% Sublimed white lead 20% Zinc oxide 40% Calcium carbonate 10% Silica 10% ---- 100% No. 29 Sublimed white lead 20% Corroded white lead 20% Zinc oxide 30% Barytes 10% Asbestine 10% Calcium carbonate 10% ---- 100% No. 30 Corroded white lead 33% Zinc oxide 33% Barytes 33% ---- 99% No. 31 Corroded white lead 45% Zinc oxide 45% Asbestine 5% Calcium carbonate 5% ---- 100% Formula No. 32. Same as No. 31 but thinned with wood turpentine No. 1. 33. Same as No. 31 but thinned with wood turpentine No. 2. 34. Same as No. 31 but thinned with wood turpentine No. 3. 35. Same as No. 31 but thinned with wood turpentine No. 4. 36. Same as No. 31 but thinned with wood turpentine No. 5. 37. Same as No. 31 but thinned with high-boiling-point petroleum spirits (turpentine substitute). 38. Same as No. 31 but ground in 50% raw linseed oil, 50% soya bean oil. 39. Same as No. 31 but ground in 50% raw linseed oil, 50% corn oil. 40. Same as No. 31 but ground in 50% raw linseed oil, 50% cotton seed oil. 41. Same as No. 31 but ground in 50% raw linseed oil, 50% rosin oil. 42. Same as No. 31 but ground in 50% raw linseed oil, 50% pine oil. CHAPTER XIV WASHINGTON PAINT TESTS The new vehicle test fence at Washington is fully described in the writer's paper[31] as presented before the American Society for Testing Materials, as follows: [31] The Practical Testing of Drying and Semi-Drying Paint Oils, by Henry A. Gardner. Paper presented at Fourteenth Annual Meeting, Amer. Soc. for Test. Mater., Atlantic City, N.J., June, 1911. "The high price attained by linseed oil during the past two years of over a dollar a gallon, together with the unusual scarcity of this valuable oil, has led many investigators into the field of research, with a view of discovering some mixture of other oils to partly replace linseed oil. Many valuable contributions to oil technology have resulted, but the makers and users of paints have wisely demanded specific and authoritative information as to the practical value of proposed mixtures before adopting them. The Institute of Industrial Research, at the request of the Paint Manufacturers' Association of the United States, has recently started a series of practical paint vehicle tests designed to decide the question at issue. "Forty-eight white-pine panels have been placed upon a test frame on the grounds of the new laboratory building of the Institute, at Washington, D. C. They are painted with a standard white pigment formula reduced with a different oil formula for every panel. White-pine panels were selected for the test on account of the good painting surface which this type of lumber presents; the grade selected was free from knots or pitch pockets--defects which often ruin a paint test. Each panel was constructed of four tongued-and-grooved planed boards, 22 inches long, 1 inch thick, and 9 inches wide. The boards were leaded together and capped at the sides with weather strips, making the finished panels about 2 feet wide and 3 feet high. The fence upon which the panels were placed was constructed of 4-inch squared yellow pine with open framework, allowing the panels a resting place upon which they were finally secured with sherardized screws. "Before erecting the panels, they were carefully painted in a paint laboratory especially fitted out for the tests. The work was done during the months of April and May, the temperature averaging from 60 degrees to 90 degrees Fahrenheit. This precaution was taken in order that the paint in each case might become thoroughly dry and hard before exposure, so that there would be no accumulation of dust or effect from exposure during the drying period. The actual painting of each panel was done personally by Mr. Charles Macnichol, master painter, of Washington, D. C., who has had a wide experience in the practical application and testing of paints. [Illustration: View of Panels on Washington Test Fence] "The viscous nature of several of the oils tested precluded the possibility of grinding each oil formula with the white pigment base selected; great heating of the paint mills and a paste of insufficient fineness was the result of an early attempt at this method. It was decided, therefore, to grind the standard pigment formula to a thick paste in the minimum amount of raw linseed oil. Subsequently a weighed amount of the white pigment base was thinned with the oil formula to be tested, to a standard viscosity, judged by the experienced master painter in charge of the practical application of the formulas as sufficiently heavy for third-coat work. When making the reductions with oil mixtures, an allowance was made for the amount of linseed oil already contained in the ground white pigment base. "During the application of the first coat an equal amount of turpentine was added to each formula, in the proportion of one-half pint to a gallon of paint; in the application of the second coat there was added to each formula a like amount of an equal mixture of turpentine and the oil formula under test. The third coat was applied without the addition of thinners of any kind. "It is well known that the time of drying and the condition of the dried film of any oil or mixture of drying or semi-drying oils will vary widely. It is for the purpose of causing oils to set up to a hard film in a short time that metallic driers in the form of salts of manganese and lead, soluble in oil, are added to a paint. Some oils require a large amount of drier, while others require only a very small amount. Those which require a large amount are apt, upon exposure, to be burned up by the drier, resulting in the formation of a powdered and disintegrated film. To add various types of drier or even differing amounts of a drier to the oils under test, seemed very unfair from every standpoint, and it was therefore decided to eliminate the drier question entirely, so as not to vitiate the results by bringing in a factor of this nature. The plan of omitting driers proved successful in the Atlantic City steel-panel paint tests, erected three years ago by the writer under the supervision of Committee A-5 of this Society. "The systematic methods which are necessary when making paint tests were carefully followed. A standard weighed amount of white pigment paste was placed in a clean paint cup and thinned to the proper consistency with a weighed amount of the oil under test. Proper reductions were made, as before stated. Weighings of the paint, cup, and brush were made before and after application to the panel, in order to determine the quantity of paint used and the spreading power. A period of fifteen days was allowed between the application of successive coats, in order to give each formula sufficient time to dry thoroughly. Although several of the formulas remained tacky for over a week, all dried thoroughly in the time allotted. (Oils which when used alone have slow drying properties, have been found to yield good firm films when used with drying pigments such as lead and zinc.) The backs and edges of each panel were painted with two coats of the paint used on the face of the panel, so as to prevent the admission of moisture. After erection, the panels were numbered with aluminum figures pressed into the surface. Frequent inspections will be made, and at the proper time reports will be issued giving the results of the tests. "During the painting of the panels considerable interesting data were collected, of which the following is a brief résumé: "The hiding power of a paint is one of its most important requisites. It was found in the tests that some oils had the effect of lessening, while others had the effect of increasing the hiding power of the standard pigment formula. This may be due in part to the varying refractive indices of the oils used, as well as to the difference in the quantity of oil required in each test. Some oils were very viscous, while others were very light. "The stiff working of heavy-bodied, blown, or heat-oxidized oils, produced films which in some cases gave a very glossy surface, even on the priming coat. Some of these resembled varnished work when finished. It will be of importance to watch these tests carefully for any signs of early breakdown, which might come from too thick a film. The treated Chinese wood oil paints worked rather stiff but produced very smooth films. The rosin oil paints became slightly lumpy on standing, but worked out to a smooth finish somewhat yellowish in color. The marine animal oils, especially the menhaden oil mixtures, dried to a film slightly flatter than straight linseed oil. Any odor which was present in the paints made from the animal oils seemed to disappear a few hours after application. The cotton seed and corn oil mixtures made the slowest drying paints, but at the end of the second week of the drying period they set up rapidly to firm films. Soya bean and perilla oils behaved like straight linseed oil, the former being a little slower and the latter slightly more rapid in drying properties. The perilla oil was made from one of the first importations into this country, and was dark in appearance. It made, however, a very easy-working and hard-drying paint. "The oils used in the tests were obtained from reliable sources. After they were received, they were carefully analyzed. The results of the analyses appear in Table 1. TABLE 1. ANALYSES OF OILS USED IN THE VEHICLE TESTS ===================================+=========+=========+========+======== |Specific |Saponifi-|Iodine | Acid |Gravity | cation |Number |Number | | Number | | -----------------------------------+---------+---------+--------+-------- Raw linseed oil |0.931 | 188 | 186 | 2.0 Boiled linseed oil (linoleate type)|0.941 | 187 | 172 | 2.7 Boiled linseed oil (resinate type) |0.930 | 186 | 176 | 2.2 Blown linseed oil |0.968 | 189 | 133 | 2.8 Lithographic linseed oil |0.970 | 199 | 102 | 2.7 Soya bean oil |0.924 | 189 | 129 | 2.3 Menhaden oil |0.932 | 187 | 158 | 3.9 Perilla oil |0.94 | 188 | 180 | 2.0 Chinese wood oil (raw) |0.944 | 183 | 166 | 3.8 Chinese wood oil (treated)[32] |0.898[32]| 128[32]| 104[32]| 6.8[32] Corn oil |0.925 | 191 | 118 | 9.5 Cottonseed oil |0.921 | 193 | 105 | 3.6 Rosin oil |0.966 | 27 | 41 |16.7 Whale oil |0.924 | 191 | 148 | -- Neutral petroleum oil[33] |0.916 | 6 | 12 | -- ===================================+=========+=========+========+======== [32] Low constants due to presence of over 40% of volatile matter, largely petroleum spirits. [33] This oil contained over 20% of petroleum spirits. "The pigment formula selected for the tests had the following composition: Basic carbonate-white lead 20% Sublimed white lead 30% Zinc oxide 35% Magnesium silicate 10% Barytes 5% 100 lbs. of pigment base ground to a stiff paste in 16 lbs. of linseed oil. "While this pigment formula was not selected as being superior to certain other formulas, it is of a type that has given very fair service in paint tests throughout the country, and will no doubt serve admirably for the purpose designed in these tests. "The vehicle formulas in the finished paints are as follows: No. 1 Raw linseed oil 100% No. 2[34] Soya bean oil 100% [34] Dry pigment formula in soya bean oil. No. 3[35] Menhaden oil 100% [35] Dry pigment formula in menhaden oil. No. 4 Raw linseed oil 25% Boiled linseed oil (resinate) 75% No. 5 Raw linseed oil 25% Boiled linseed oil (linoleate) 75% No. 6 Raw linseed oil 50% Boiled linseed oil (resinate) 50% No. 7 Raw linseed oil 50% Boiled linseed oil (linoleate) 50% No. 8 Raw linseed oil 50% Blown linseed oil 50% No. 9 Raw linseed oil 50% Litho. linseed oil 50% No. 10 Raw linseed oil 50% Soya bean oil 50% No. 11 Raw linseed oil 50% Menhaden oil 50% No. 12 Raw linseed oil 50% Perilla oil 50% No. 13 Raw linseed oil 50% Treated wood oil 50% No. 14 Raw linseed oil 50% Corn oil 50% No. 15 Raw linseed oil 50% Cottonseed oil 50% No. 16 Raw linseed oil 50% Rosin oil 50% No. 17 Raw linseed oil 50% Whale oil 50% No. 18 Raw linseed oil 75% Soya bean oil 25% No. 19 Raw linseed oil 75% Menhaden oil 25% No. 20 Raw linseed oil 75% Perilla oil 25% No. 21 Raw linseed oil 75% Treated wood oil 25% No. 22 Raw linseed oil 75% Corn oil 25% No. 23 Raw linseed oil 75% Cottonseed oil 25% No. 24 Raw linseed oil 75% Rosin oil 25% No. 25 Raw linseed oil 50% Soya bean oil 25% Menhaden oil 25% No. 26 Raw linseed oil 50% Soya bean oil 25% Treated wood oil 25% No. 27 Blown linseed oil 50% Soya bean oil 50% No. 28 Raw linseed oil 25% Soya bean oil 25% Menhaden oil 25% Treated wood oil 25% No. 29 Raw linseed oil 25% Soya bean oil 25% Menhaden oil 25% Corn oil 25% No. 30 Raw linseed oil 25% Soya bean oil 25% Menhaden oil 25% Cottonseed oil 25% No. 31 Raw linseed oil 25% Soya bean oil 25% Menhaden oil 25% Rosin oil 25% No. 32 Raw linseed oil 25% Soya bean oil 25% Treated wood oil 25% Rosin oil 25% No. 33 Raw linseed oil 20% Soya bean oil 20% Treated wood oil 20% Menhaden oil 20% Cottonseed oil 20% No. 34 Raw linseed oil 20% Soya bean oil 20% Treated wood oil 20% Menhaden oil 20% Rosin oil 20% No. 35 Raw linseed oil 40% Soya bean oil 20% Corn oil 20% Cottonseed oil 20% No. 36 Whale oil 33% Treated wood oil 33% Raw linseed oil 33% No. 37 Raw linseed oil 25% L. O.[36] 75% No. 38 Raw linseed oil 50% Raw Chinese wood oil 50% No. 39 Raw linseed oil 75% Reducing oil[37] 25% No. 40 Raw linseed oil 50% Soya bean oil 35% Neutral petroleum oil 15% No. 41 Raw linseed oil 50% Soya bean oil 25% Neutral petroleum oil 15% Tungate drier 10% No. 42 Linseed oil 25% Soya bean oil 37% Neutral petroleum oil 23% Tungate drier 15% No. 43 Raw linseed oil 25% Soya bean oil 37% Whale oil 19% Tungate drier 19% [36] Mixture of boiled tung and soya bean oil, thinned with petroleum and turpentine. [37] 25% raw linseed oil. 73% petroleum oil. 2% drier--lead and manganese linoleate." No. 44 Special test on white base of the following composition, in pure linseed oil: Asbestine 10% Corroded white lead 20% Sublimed white lead 30% Zinc oxide 40% Upper board of panel reduced with straight turpentine on priming coat. Second board of panel reduced with wood turpentine on priming coat. Third board of panel reduced with pine oil on priming coat. Bottom board of panel reduced with petroleum spirits on priming coat. No. 45 Same pigment formula as No. 44, reduced with: Pine oil 50% Linseed oil 50% No. 46 Special test of white base of the following composition, in pure linseed oil: Corroded white lead 20% Sublimed white lead 30% Zinc oxide 35% Asbestine 15% No. 47 Cypress panel unpainted. No. 48 Cypress panel painted with formula No. 1, thinned with benzol on the priming coat. CHAPTER XV CEMENT AND CONCRETE PAINT TESTS =Damp-proofing and Waterproofing.= The decoration and preservation of cement and concrete is a subject which is being given the careful consideration of many technologists on account of the wide usage of cement for structural purposes, and the necessity of properly guarding it against the destructive effects of moisture. To obtain with various paints decorative effects, and, at the same time, provide a high degree of damp-proofing, is a process quite distinct from that of water-proofing cement and concrete superstructures. The use, in small percentage, of stearic acid solutions, aluminum stearate, marine animal soaps, and other lime-reacting materials, as a component of concrete while it is being mixed, has been in practice for some time, the resulting mixture being used largely upon base-work subjected to water under high pressure. Although some of the materials used for such purposes actually do give to the concrete a high power of water resistance, the degree of waterproofing to be obtained through the use of many such compounds varies to a wide extent, often interfering with the lime-silica reactions, and ultimately affecting the strength of the finished concrete. =Decorative and Preservative Coatings.= The necessity of obtaining suitable paint coatings for cement and concrete surfaces suggested to the writer a series of tests on paints designed to prevent the destructive action of the lime which, by seepage and other physical action, is brought to the surface, causing saponification of some oil coatings, as well as destruction of color. The tests referred to were carried out during 1908, and although great advances have been made since that time in the preparation of concrete paints, the tests have, nevertheless, afforded information of a valuable nature as indicating the proper methods to follow in the painting of cement, as well as suitable materials to use in the manufacture of cement paints. The tests, moreover, show the comparative durability of a number of paints typical of those prominent in the market at the time the tests were started. [Illustration: View of Concrete Paint Test Panels] =Acid Reacting Compounds.= A series of acid reacting washes were included in the tests, having been designed as prime coaters for use previous to the application of oil paints. The application of many of these washes has the effect of neutralizing the lime within cement and concrete surfaces, and often precipitate insoluble lime compounds which aid in filling up the outer voids, thus presenting a surface more suitable to receive oil coatings. To the writer who has since made a careful study of the painting of concrete, it would seem advisable for painters to avoid, when possible, the use of these lime neutralizing washes, as some of them have more or less disintegrating and weakening influences upon concrete. Recent laboratory experiments, however, have indicated that zinc sulphate, an acid reacting material used for many years as a wash for concrete surfaces by Macnichol, actually has a strengthening effect upon cement and concrete surfaces. The more successful coatings of to-day, however, are those which may be placed directly upon the cement and concrete surfaces without the aid of such washes. Several fairly successful paints of this type have recently appeared in the market; some of them being made of acid rosins compounded with vegetable oils. Probably one of the first mixtures of this sort was the so-called suction varnish which the master painter has for years used as a prime coating on plastered walls previous to painting. These suction varnishes generally contain a high percentage of rosin, a material having an exceptionally high acid value and thus lending itself successfully to the neutralization of free lime. It has been claimed, however, by certain practical painters that the lime-rosin compounds formed when such paints are applied to the exterior of buildings, are of a brittle nature and subject to early failure. If this is true, it would seem advisable to use in a concrete paint an oil of a relatively unsaponifiable nature, which would withstand successfully the action of the lime, and, at the same time, prevent disruption of the coating and failure of the color used in the paint. =Outline of Tests.= The tests referred to as carried out by the writer were made on a brick wall forty feet long, surface-coated with a four-inch coating of Portland cement mortar made of one part of Portland cement and three parts of sharp, clean sand. After the cement had hardened for three days, the solutions under test were applied. In many of the tests outlined above, one-coat, as well as two-coat work, was used on different sections of the test surfaces. It was shown that the two-coat work gave far better results than with the one-coat work, and the writer would recommend for the painting of concrete at least two-coat work. Whenever paints containing Prussian blue or chrome green are applied to concrete surfaces, immediate whitening in the case of the blue, and yellowing in the case of the green, will take place, if any degree of action has been exerted by the lime within the concrete. For this reason, green is an especially delicate color to test and should be utilized for this purpose. The materials used, and the results shown at an inspection made after two years' exposure, are given herewith. =Test No. 1.= Concrete primed with a 25% solution of zinc sulphate crystals dissolved in water. A wide brush was used for the application, and the spreading rate was approximately 200 square feet per gallon. Second and third coated on the second day with No. 119 blue paint of the following composition: NO. 119 BLUE PAINT Sublimed white lead 50% Zinc oxide 35% Silica and barytes 12% Prussian blue 3% Ground in linseed oil, turpentine and drier. This panel, after three years' exposure, is in good condition. Slight checking observed. =Test No. 2.= Concrete primed with a 20% solution of (alum) (aluminum sulphate). Second and third coated with No. 119 blue. In similar condition to Test No. 1. =Test No. 3.= Concrete primed with zinc sulphate followed by two coats of para red. PARA RED FORMULA Blanc fixe 60% Whiting 25% Zinc oxide 3% Paranitraniline lake 12% Ground in linseed oil, turpentine and drier. Panel in fair condition with exception of slight crazing. Characteristic dullness of color after exposure shown. Bright red color restored upon washing. =Test No. 4.= Concrete primed with an 8% solution of stearic acid and rosin dissolved in benzine. Second and third coated with No. 119 blue. This panel is not in as good condition as Tests Nos. 1 and 2, and would indicate the inferiority of the priming liquid used. Color failing in spots and checking observed. =Test No. 5.= Concrete primed with mixture used in Test No. 4, and then given two coats of para red. Test is in about the same condition as No. 4. =Test No. 6.= Concrete primed with a 10% mixture of acid calcium phosphate, followed with two coats of No. 119 blue. The acid phosphate solution evidently had a neutralizing effect upon the lime in the concrete, as the paint is in fair condition. =Test No. 7.= Concrete primed with one coat of a soap emulsion of the following composition, then painted with two coats of No. 119 blue. Water 85% Linseed oil 12% Alkali 3% Very poor results obtained. Destruction of color and peeling resulted. =Test No. 8.= Concrete primed with one coat of white paint of the following composition: PRIMER Zinc oxide 25% Silica 35% Corroded white lead 20% Gypsum 15% Whiting, etc. 5% Ground in a vehicle of linseed oil and containing 35% of volatile hydrocarbon spirits and drier. This coat was followed by one of the following composition, tinted blue: Zinc oxide 60% Gypsum 20% Silica 20% Ground in linseed oil with 12% of turpentine and drier. Fair results shown during first year, but a breakdown occurred during the second year, and cracking and scaling resulted. =Test No. 9.= This test was a duplicate of No. 8 with the addition of 5% of zinc sulphate solution emulsified into the primer. Slightly superior to Test No. 8. =Test No. 10.= Primed with a white paste paint thinned with turpentine. Second coated with same paint tinted blue. FORMULA OF PASTE Zinc oxide 40% Whiting 30% Silica 20% Alumina and gypsum 10% Ground in 16% of linseed oil vehicle. Scaling and peeling due to lack of binder and use of saponifiable oil resulted during the first six months' exposure. Entire destruction of coating at end of two years. =Test No. 11.= Primed with a white mixture, and second coated with the same mixture tinted blue. FORMULA OF MIXTURE Whiting 30% Silica 30% Zinc oxide 40% Stirred into a 5% solution of glue in water, until a fairly thick paste was obtained. Much chalking was shown, and a bleaching of color. It is evident that this mixture would not serve to keep moisture out. =Test No. 12 A.= Primed with a 5% solution of soluble nitrated cotton and paraffin dissolved in equal parts of amyl acetate and benzine. Second coated with No. 119 blue. Not very good results were obtained, chalking and slight scaling resulting. =Test No. 12 B.= Primed with a heavy varnish containing Chinese wood oil and kauri gum. Second coated with No. 119 blue. Fair results obtained. =Tests Nos. 13, 14, 15, and 16.= Primed with a solution made by dissolving 10 parts of sodium oxalate in 100 parts of water. Second and third coated with linseed oil paints in red, brown, blue, and green. Very good results shown at end of test. =Test No. 20, Special.= Primed and second coated with a green paint containing zinc oxide and barytes, ground in an oil having a low saponification value. Very slow drying was shown. Excellent results. No failure of color. Extremely glossy, waterproof surface presented. CHAPTER XVI STRUCTURAL STEEL PAINT TESTS =The Necessity of Protective Coatings.= Most painters have in the past considered of minor importance the painting of iron and steel; any paint that would properly hide the surface of the metal being accepted without much question. The demand, however, for structural steel for office buildings, factories, steel cars, railroad equipment, etc., has doubled the output of structural paints, and created a demand for painters having a knowledge of the proper materials to use in the painting of steel, so that its life may be preserved, and its strength maintained. Such knowledge is as important to the painter as a knowledge of how to properly select materials for the painting of wood, and how to temper these materials to suit the various conditions met with. =The Cause of Rust.= Everyone is familiar with the appearance of rust, but few actually understand what causes rust. No attempt will be made here to present even an outline of the many theories advanced to explain the phenomenon of the rusting of iron, for the subject is as diverse as it is interesting. A brief résumé, however, will be given of the now generally accepted theory that explains the subject. This theory is called the electrolytic theory. "Auto-electrolysis" is the term used to define the peculiar tendency of iron to be transformed from a metal possessing a hard lustrous surface, high tensile strength, and other useful properties, to a crumbling oxide that falls to the ground and again becomes part of the earth from which it was originally taken by man. [Illustration: A Side View of Steel Test Fences] This "going back to nature" is more readily accomplished by most of the steel produced to-day than by the old hand-made irons produced many years ago. It seems to be a curious fact that the more quickly a product or an article is fashioned by man, the more quickly it tends to return again to its original oxidized condition. Some manufacturers of steel, however, through an understanding of the causes of rust, have progressed in the manufacture of slow rusting materials, either by the elimination, or by the proper distribution of impurities. When iron is brought into contact with moisture, currents of electricity flow over the surface of the iron between points that are relatively pure and points that contain impurities. These currents stimulate the natural tendency of the iron to go into solution, and the solution proceeds with vigor at the positive points. The air which the water contains oxidizes the iron which has gone into solution, and precipitates the familiar brown iron rust. Thus water, which acts as an acid, and air, which acts as an oxidizer, have combined together to accomplish the downfall of the metal. [Illustration: Three Photomicrographs of Corroding Steel] =Inhibition and Stimulation of Rust.= It is obvious that if means could be devised to stop the solution pressure of iron and make it resistant to the flow of surface electric currents, rust could be prevented. Such methods have been devised, and to better illustrate how they operate, an analogy may be drawn between iron in water and shellac in alcohol. It is common knowledge that when shellac is placed in alcohol, the shellac will force itself into solution in the alcohol, and form a clear, transparent lacquer. If, however, there should be mixed with the alcohol a quantity of water, it would be found that the shellac could no longer go into solution, and it would remain in its original condition. In the same way, if there be placed in water a small quantity of material, such as soluble chromates, or an alkaline substance like caustic soda or lime, it will be found that iron will no longer have a tendency to go into solution in this treated water, but will stay bright and clean. These materials which prevent the rusting of iron have been called by Cushman, who first advanced these explanations, "rust inhibitors," or materials which inhibit rusting. The paint maker, realizing the importance of these rust inhibitors, is incorporating them into paints designed for the protection of iron and steel, and the success which paints of this type have met with from a practical standpoint is a justification of what was first called the "electrolytic theory," which suggested their use. By placing small, brightly polished steel plates into a mush of paint pigment and water, a determination may be made of the pigment's effect upon the metal. Some pigments, under such conditions, cause rapid corrosion of the steel plates. Such pigments are stimulators of corrosion, on account of acid impurities which they contain, or because of their effect in stimulating galvanic currents. Many carbonaceous pigments are of this type. Other pigments have the effect of keeping bright the steel plates and preventing rust. Such pigments are of the inhibitive type, and their action is to check or retard the solution pressure of the iron. =The Effects of Moisture.= It might occur to the reader that although paint pigments, when mixed up with water and brought into contact with the surface of steel, might show either an inhibitive or stimulative action, that it is by no means certain that the same tendency will be exhibited by pigments when they are properly mixed with linseed oil and laid out as a film upon the surface of steel. In answer to this, it may be well to state that almost no material used by mankind is absolutely dry. Linseed oil, as it is pressed from the seed, comes from the cells, carrying with it a certain small definite percentage of water, and it is quite certain that even the best linseed oil that goes into use is not theoretically dry. Everyone knows, of course, that oil and water do not readily mix and are, in fact, more or less repellent to each other. It is, however, true that, in spite of this, oils can carry quite a percentage of water, without the admixture being apparent to the eye. In addition to this, careful experiments have proved very conclusively that linseed oil films, even after they have oxidized and hardened, have the power to a certain extent of absorbing water from the atmosphere. It is, therefore, safe to say that no linseed oil film in a paint coating is dry all the time. As a matter of fact, there is abundant evidence to show that in rainy weather, and, in fact, when the humidity in the air is high, paint films have absorbed water. As the sun comes out and warms the paint coating, and the humidity content of the atmosphere falls, this water to a large extent evaporates out of the film, only to be taken up again when the weather conditions change. This action may be likened to a breathing of the paint film, that is to say, an indrawing of water under humid conditions, followed by an exhaling of water under dry conditions. With these facts in mind, it must be apparent that pigments laid out in intimate contact with the surface of steel are subjected at all times either more or less to the reactions produced by water contact. Furthermore, as it is a property of water to become saturated with the gases of the atmosphere, such as oxygen, carbonic and sulphurous acids, and other impurities, there is present in a protective paint film at all times the elements necessary to carry on the corrosive process and reactions. An outline of Cushman's original research work, upon which has been based the classification of pigments as inhibitors, stimulators, and inerts, is clearly presented in his report[38] as Chairman of Committee U of the American Society for Testing Materials, of which the following is an excerpt: [38] Page 73, 1910 Proceedings of the American Society for Testing Materials. [Illustration: Ferroxyl Tests on Painted Steel Surfaces. Upper Row Painted with Stimulative Paints--Lower Row with Inhibitive Paints.] [Illustration: Water Test on Plates Painted--Except in Center Spot. Left Hand Plates Painted with Stimulative Paints, Right Hand Plates Painted with Inhibitive Paints.] [Illustration: View of Steel Plates Painted with Stimulative Paints, after Immersion in Ferroxyl Jelly.] "Three years ago the suggestion was made in a paper presented before the Tenth Annual Meeting of this Society that the various types of substances used as pigments in protective coatings might exert a stimulative or an inhibitive action on the rate and tendency to corrosion of the underlying metal. It was further suggested on a theoretical ground that slightly soluble chromates should exert a protective action when employed as pigments by maintaining the surface of the iron in a passive condition in case water and oxygen penetrated the paint film. In view also of the well-known fact that alkalies inhibit while acids stimulate the corrosion of iron, it was suggested that the action of more or less pure pigments on iron in the presence of water should be thoroughly investigated. Two years ago this Committee invited the co-operation of Committee D-1 (then known as Committee E) in the investigation, and a special sub-committee representing the two main committees was appointed. "The methods and results of the water-pigment tests have previously been reported and published, and need not be given in detail. Briefly, the method consisted in immersing samples of steel in water suspensions of the various pigments and blowing air through the containers for definite periods of time, the corrosion being measured by the loss in weight sustained by the test pieces. About fifty pigments which are in more or less common use for painting steel were purchased in the open market and distributed among a number of the members of the Committee, who agreed to carry out the work. Each investigator worked independently of the others, except that the same general method was followed; the time of exposure to the corroding action, however, varied in the different experiments. When the results were compared and analyzed by the sub-committee, it was felt that the general agreement of the results obtained by the several investigators was striking and merited further and more systematic work. As a result of these tests the sub-committee tentatively divided the pigments into inhibitors, stimulators, and indeterminates. The word 'indeterminate' was selected after considerable discussion, because the words 'neutral' or 'inert' already possess a special meaning as applied to paint technology. The Committee takes this occasion to emphatically state that in adopting this tentative classification, the words 'inhibitive' and 'stimulative' as used by them up to the present time apply only to the results obtained in the water tests, and the inference that the results obtained have decided which class the pigment will fall into when made into a paint with the usual vehicles and used as a protective coating on iron and steel, is not justified. In order to make this point quite clear, it has been agreed by the Committee to qualify the classification so as to speak of the various materials tested as 'water stimulative' or 'water inhibitive.'" [Illustration: Apparatus for Testing the Inhibitive Value of Pigments] =Importance of Field Tests.= Although the laboratory accelerated tests for the determination of the relative value of structural steel paints afford information of some import, there seems to be a general opinion that the best method to follow, if information of a reliable character is to be obtained, is to make actual field exposure tests upon large surfaces. The results of the above described water-pigment tests suggested the erection of a series of steel panels on which to test out the same pigments under practical service conditions. The Paint Manufacturers' Association of the United States erected and painted the panels, the work being under the constant supervision of the writer, and the inspection of the work under Committee U of the American Society for Testing Materials. A brief résumé of the work[39] is herewith presented. [39] Page 181, "Corrosion and Preservation of Iron and Steel"--Cushman and Gardner--McGraw-Hill Book Co., New York City. =Pickling and Preparation of Plates.= The three types of metal[40] selected for the test were rolled to billets, the middle of which were selected, and worked up into plates 24 inches wide, 36 inches high, and 1/8 inch in diameter--approximately 11 gauge. A number of plates of each of the metals selected, in all 450, were pickled in 10% sulphuric acid, kept at 180 to 200 degrees Fahrenheit, in order to remove the mill-scale. The plates were then washed in water, and later in 10% solution of caustic soda. Finally the plates were again washed in water and wiped dry. They were then packed in boxes containing dry lime, in order to prevent superficial corrosion. By this method the plates were secured in perfect condition, the surfaces being smooth and free from scale. Upon these pickled plates paints were applied with a definite spreading rate of 900 square feet per gallon. The unpickled plates, coated with mill-scale, were painted with the same paints, but without adopting any special spreading rate, thus following more closely the ordinary method of painting structural steel. A few extra plates of special Bessemer steel and Swedish charcoal iron were also included in the test, some of which were painted, while others were exposed without any protective coating. Plates of the three types of metal already mentioned were also exposed unpainted, both in the black and pickled condition. [40] Bessemer Steel, Open Hearth Steel, and Pure Iron. [Illustration: Front View of Steel Test Fences] =Fence Erection and Preparation for Work.= The fences which were erected for the holding of the plates were constructed of yellow pine, the posts being set deeply in the ground and properly braced. The framework of the fence was open, with a ledge upon the lateral girders, upon which the plates might rest, and to which the plates were secured by the use of steel buttons. After the framework had been erected, painted, and made ready for the placement of the panels, a small shed was built upon the ground, and the materials for the field test placed therein. The steel plates were unpacked from the boxes in which they were shipped, brushed off, and stacked up ready for painting. Small benches were erected, and the accessories of the work, such as cans, brushes, pots, balances, etc., were placed in position. =Methods Followed in Painting Plates.= A frame resting upon the workbench served to hold the plates in a lateral position while being painted, room being allowed beneath the plate for the operator to place his hands in order to lift the plates from the under surface after the painting had been finished. A pickled plate having been placed upon the framework everything was in readiness for the work. The specific gravity and weight per gallon of the paint to be applied was determined, and the amount, in grams, to be applied to each individual panel was calculated according to the following formula: Spreading rate Sq. ft. in plate Grams paint in gal. 900 sq. ft. : 6 :: 5400 : x The reciprocal of _x_ being the number of grams of paint to be applied to the panels. An enamel cup was then filled with the paint and a brush well stirred within. The cup, paint, and brush were placed upon the balances and accurately weighed in grams. After most of the paint had been applied to the panel, cross-brushing of the panel was continued until the pot with brush and paint exactly counterbalanced the deducted weight. The painted panel was then set in a rack, in a horizontal position to dry. A period of eight days elapsed between the drying of each coat. The greatest care was taken in the painting of the edges of the plates, and the racks for containing the plates after they were painted were so constructed that the paint would not be abraded while sliding the plates back and forth. The working properties of each paint, and the appearance of the surface of each plate after painting, were carefully noted and included in the report. No reductions were made to any of the paints applied except in three cases, where the viscosity was so great that it was necessary to add a small amount of pure spirits of turpentine. The amount of paint was proportionately increased in such cases, so that the evaporation of the turpentine would leave upon the plate the amount of paint originally intended. The appearance of the completed series of test panels is shown on page 221. =Vehicles Used and Reasons for Avoidance of Japan Driers.= The pigments used were selected with the view to securing as nearly as possible purity and strength, and as already noted, were out of the same lots used in making the preliminary laboratory tests on inhibitives. They were ground in a vehicle composed of two parts of raw linseed oil and one part of pure boiled oil. Paint is generally caused to dry rapidly by the use of japan or driers. These materials contain a large amount of metallic oxides which might have some effect in either exciting or retarding corrosion. To prevent the introduction of such a factor, these materials were not used in the test. The boiled oil, with its small percentages of metallic oxides, was sufficient, however, to cause the paints to dry in a short time after they were spread. =Testing Effect of Various Prime Coats.= Some of the special tests made included a series of plates prime-coated with different inhibitive pigments, and these tests were designed to determine which pigments offer the best results for such work. These plates were all second-coated with the same paint. It is the opinion of the authors that any good excluding paint may be used whether it be inhibitive in action or not, provided the contact coat is inhibitive. If, however, both coats can be designed so as to have the maximum possible value from both these points of view, the best results would, of course, accrue. The only way such data can be obtained is by careful observation of the results of exposure tests. =Combination Formulas Tested.= By selecting a series of pigments which in the water tests showed inhibitive tendencies, and properly combining these pigments into a paint, it was thought possible that a more or less inhibitive paint would be produced. If this proved to be the case, it would follow that the selection and introduction into a paint of the stimulative pigments would inevitably produce a paint unfit for use on iron or steel. =Data on Application of Paints.= The recorded data on the application of the paint to the panels is voluminous. There is presented herewith, however, the data on two of the paints. NO. 2, QUICK PROCESS WHITE LEAD: Sp. Gr. of pigment 6.78 Lbs. to gallon oil 20.34 Sp. Gr. of paint as received 2.47 Wt. of paint per gallon 20.56 Grams to panel 62 Condition of paint Good Working properties Works easy Drying 24 hrs. all coats 1 coat Oct. 26 T 60 B 29.94 W. fair 2 coat Nov. 3 T 54 B 30.23 W. clear 3 coat Nov. 7 T 52 B 29.66 W. cloudy NO. 9, ORANGE MINERAL (AMERICAN): Sp. Gr. of pigment 8.97 Lbs. to gallon oil 26.91 Sp. Gr. of paint as received 2.97 Wt. of paint per gallon 24.74 Grams to panel 74.7 Condition of paint Good Working properties Smooth--no brush marks Drying Good 1 coat Oct. 28 T 58 B 30.01 W. cloudy 2 coat Nov. 4 T 65 B 29.61 W. cloudy 3 coat Nov. 9 T 58 B 29.91 W. clear =Composition of Paints.= The following table gives data regarding the composition, etc., of paints applied to the steel panels. =Results of Inspection.= The results of an inspection of the steel test plates, made by Sub-committee D representing Committee D-1 of the American Society for Testing Materials, is herewith presented: "On Wednesday, June 28, 1911, the second inspection of the Atlantic City Steel Test Panels, erected in October, 1908, was made by Sub-committee D of Committee D-1, this Committee having agreed to report upon the condition of the painted surfaces, leaving any report on the comparative corrosion of the various types of metal used in the test to Committee A-5 on the corrosion of iron. ===+=========================+=======+=======+======+=======+========= | | | | | |Grams | | | | | |Paint | | |Wt. of | Sp. |Wt. of |to Panel | Name | Sp. |Pigment| Gr. | Paint |at 900 | | Gr. |to Gal.| of | per |Sq. ft. Pigment |of Pig-|of oil |Paint | Gal. |spreading No.| | ment | Lbs. |Rec'd | Lbs. |rate ---+-------------------------+-------+-------+------+-------+--------- 1|Dutch process white lead | 6.83 | 20.49 | 2.45 | 20.49 | 61.0 2|Quick process white lead | 6.78 | 20.34 | 2.47 | 20.34 | 62.0 3|Zinc oxide | 5.56 | 16.68 | 2.12 | 16.68 | 59.0 4|Sublimed white lead | 6.45 | 19.17 | 2.36 | 19.17 | 59.0 5|Sublimed blue lead | 6.39 | 19.17 | 2.42 | 19.17 | 61.0 6|Lithopone | 4.26 | 12.78 | 1.80 | 12.78 | 45.3 7|Zinc lead white | 4.42 | 13.26 | 1.96 | 13.26 | 49.4 9|American orange mineral | 8.97 | 26.91 | 2.97 | 26.91 | 74.7 10|Red lead | 8.70 | 26.10 | 2.93 | 26.10 | 73.6 12|Bright red oxide | 5.26 | 15.78 | 2.05 | 15.78 | 60.0 14|Venetian red | 3.1 | 9.30 | 1.52 | 9.30 | 38.0 15|Prince's metallic brown | 3.17 | 9.51 | 1.50 | 9.51 | 37.7 16|Natural graphite | 2.60 | 7.80 | 1.37 | 7.80 | 34.4 17|Acheson graphite | 2.21 | 6.63 | 1.22 | 6.63 | 30.8 19| {Lampblack | | 1.82}| | 1.82 | | {Barytes | 1.82 | 8.92}| 1.60 | 8.92 | 40.2 20|Willow charcoal | 1.49 | 4.47 | 1.08 | 4.47 | 27.0 21| {Gas carbon black | 1.85 | 1.39}| 1.67 | 1.39 | | {Natural barytes | | 10.03}| | 10.03 | 50.7 24|French yellow ochre | 2.94 | 8.82 | 1.46 | 8.82 | 37.0 27|Natural barytes | 4.46 | 13.38 | 1.83 | 13.38 | 46.0 28|Precipitated barytes | 4.23 | 12.69 | 1.84 | 12.69 | 46.0 |(blanc fixe) | | | | | 29|Calcium carbonate | 5.48 | 8.22 | 1.37 | 8.22 | 34.5 |(whiting) | | | | | 30|Calcium carbonate | 2.56 | 7.68 | 1.35 | 7.68 | 34.0 |precipitated | | | | | 31|Calcium sulphate (gypsum)| 2.33 | 6.99 | 1.25 | 6.99 | 31.4 32|China clay (kaolin) | 2.67 | 8.01 | 1.34 | 8.01 | 34.0 33|Asbestine (silicate of | 2.75 | 8.25 | 1.38 | 8.25 | 34.7 |magnesium) | | | | | 34|American vermilion | 6.83 | 20.49 | | 20.49 | 64.5 |(chrome scarlet) | | | | | 36|Medium chrome yellow | 5.88 | 17.64 | | 17.64 | 67.1 39|Zinc chromate | 3.57 | 10.71 | 1.57 | 10.71 | 39.2 40|Zinc and barium chromate | 3.45 | 10.35 | 1.58 | 10.35 | 40.0 41|Chrome green (blue tone) | 4.44 | 13.32 | 1.94 | 13.32 | 49.0 44|Prussian blue | 1.96 | 5.88 | | 5.88 | 30.0 45|Prussian blue | 1.93 | 5.79 | | 5.79 | 34.5 48|Ultramarine blue | 2.40 | 7.20 | 1.29 | 7.20 | 32.5 49|Zinc and lead chromate | 4.76 | 14.28 | 1.92 | 14.28 | 48.3 51|Magnetic black oxide | | 15.00 | 1.92 | 15 | 48.3 | | | | | | | _Composite Paints_ | | | | | | | | | | | 111|Brown } Made from pig- | | 10.82 | 1.30 | 10.82 | 32.7 222|Black } ments that were | | 10.86 | 1.30 | 10.86 | 32.8 333|White } inhibitive in the| | 14.52 | 1.74 | 14.52 | 43.8 444|Green } water test | | 12.77 | 1.53 | 12.77 | 38.6 | | | | | | 555|Black } Made from pig- | | 9.37 | 1.125| 9.37 | 28. 666|Brown } ments that were | | 11.74 | 1.41 | 11.74 | 35.5 777|White } stimulative in | | 14.55 | 1.75 | 14.55 | 44. 888|Green } the water test | | 14.57 | 1.75 | 14.57 | 14.57 ===+=========================+=======+=======+======+=======+========= "According to the amount of rust apparent on the painted surfaces of the panels, as well as the degree of checking, chalking, scaling, cracking, peeling, loss of color, and other signs of paint failure shown, ratings were given each panel. The system of rating which took into consideration all the above conditions, was similar to the system used at the first inspection during 1910, when 0 (zero) recorded the worst results and 10 (ten) the best results. "In Table No. 1 there is shown the rating accorded by each inspector to each panel, as well as an average for each panel. TABLE NO. 1.--SECOND INSPECTION OF STEEL PAINT TEST PANELS AT ATLANTIC CITY, N. J., BY SUB-COMMITTEE D OF COMMITTEE D-1 =======+========================+======+======+=======+=======+======= | | | | H. A. | | Panel | |W. H. |P. H. |Gardner| C. | No. | Pigment |Walker|Walker|Chair- |Chapman|Average | | | | man | | -------+------------------------+------+------+-------+-------+------- 1 |Dutch process white lead| 2 | 3 | 3 | 5 | 3.7 2 |Quick process white lead| 4 | 4 | 3 | 6 | 4.2 3 |Zinc oxide (XX) | 1 | 1-1/2| 1 | 2-1/2| 1.5 4 |Sublimed white lead | 9 | 9-1/2| 9 | 8-1/2| 9.0 5 |Sublimed blue lead | 9 | 9-1/2| 9-1/2| 7-1/2| 8.8 6 |Lithopone | 2 | 1-1/2| 2 | 3-1/2| 2.2 7 |Zinc lead white | 3 | 4 | 5 | 7 | 4.7 9 |Orange mineral | 9 | 9 | 9 | 6-1/2| 8.3 10 |Red lead | 9 | 9 | 9 | 6-1/2| 8.3 12 |Bright red oxide | 8-1/2| 9 | 8 | 7 | 8.1 14 |Venetian red | 7 | 9 | 7 | 9 | 8.0 15 |Prince's metallic brown | 5 | 7-1/2| 6 | 8 | 6.3 16 |Natural graphite | 6 | 8 | 4 | 9-1/2| 6.8 17 |Artificial graphite | 5 | 7-1/2| 4 | 7 | 5.9 19 |Lampblack | 5 | 7-1/2| 5 | 8 | 6.3 20 |Willow charcoal | 9 | 8-1/2| 9 | 9 | 8.8 21 |Carbon black | 7 | 8-1/2| 5 | 8-1/2| 7.2 24 |Yellow ochre (French) | 5 | 7 | 2 | 8 | 5.5 27 |Barytes (natural) | 1 | 1 | 1 | 0 | 0.7 28 |Barytes (precipitated) | 2 | 1-1/2| 2 | 2 | 1.8 29 |Calcium carbonate | 0 | 0 | 0 | 0 | 0.0 |(whiting) | | | | | 30 |Calcium carbonate (pre- | 0 | 0 | 0 | 0 | 0.0 |cipitated) | | | | | 31 |Calcium sulphate | 1 | 1 | 1 | 3 | 1.7 |(gypsum) | | | | | 32 |China clay (kaolin) | 6 | 6 | 7 | 6-1/2| 6.3 33 |Asbestine (magnes. sili-| 5 | 4-1/2| 6 | 5 | 5.1 |cate) | | | | | 34 |American vermilion |10 |10 | 10 | 10 | 10.0 36 |Lead chromate | 7 | 7-1/2| 8-1/2| 8 | 7.7 39 |Zinc chromate | 9 | 9 | 10 | 9-1/2| 9.5 40 |Zinc and barium chromate| 9 | 9-1/2| 10 | 9-1/2| 9.5 41 |Chrome green (blue tone)|10 |10 | 10 | 9-1/2| 9.8 44 |Prussian blue, W. S | 9 | 9-1/2| 9-1/2| 9 | 9.0 45 |Prussian blue, W. I | 8 | 9-1/2| 8-1/2| 8-1/2| 8.5 48 |Ultramarine blue | 0 | 0 | 0 | 0 | 0.0 49 |Zinc and lead chromate |10 | 9-1/2| 10 | 9-1/2| 9.7 51 |Magnetic black oxide | 9 | 9-1/2| 10 | 9-1/2| 9.5 111 |Brown composite paint | 7 | 9 | 9 | 9 | 8.5 222 |Black composite paint | 9 | 9 | 9 | 8-1/2| 8.8 3333 |White composite paint | 4 | 4 | 7 | 3 | 4.5 444 |Green composite paint | 5 | 7 | 7 | 8 | 6.7 555 |Black composite paint | 9 | 9 | 6 | 9 | 8.2 666 |Brown composite paint | 8 | 8 | 6 | 9 | 7.7 777 |White composite paint | 7 |10 | 5 | 7 | 7.2 888 |Green composite paint | 7 | 8 | 8 | 9 | 8.0 2000 |1 coat zinc chromate }| 8 | 8-1/2| 8 | 8 | 8.1 |1 coat iron oxide ex- }| | | | | |cluder }| | | | | 3000 |1 coat lead chromate | 7 | 8 | 7 | 7-1/2| 7.3 4000 |1 coat red lead }| 7 | 8-1/2| 8 | 7-1/2| 7.7 |1 coat iron oxide ex- }| | | | | |cluder }| | | | | 100 |Straight carbon black | 5 | 8-1/2| 4 | 8-1/2| 6.5 |paint with turps and | | | | | |drier | | | | | 90 |Straight lampblack paint| 5 | 7 | 3 | 8 | 5.7 |with turps and drier | | | | | 5555 |Coal tar paint over red | 4 | 8 | 2 | 7 | 5.2 |lead | | | | | 1000 |Chrome resinate in oil | 1 | 0 | 0 | 2 | 0.7 |(1 coat) | | | | | 1 plate|3 coats boiled linseed | 1 | 0 | 1 | 4 | 1.5 |oil | | | | | =======+========================+======+======+=======+=======+======= "In Table No. 2 there is shown the rating obtained by those panels which were considered by the committee as meriting from 8 to 10, and having given the best all-round service. TABLE NO. 2.--ANALYSIS OF AVERAGES. GRADE OF EXCELLENCE FROM 8 TO 10 =====+=============================================+======= Plate| Pigment |Average -----+---------------------------------------------+------- 34 | American vermilion (basic chromate of lead) | 10.0 41 | Chrome green | 9.8 49 | Lead and zinc chromate | 9.7 39 | Zinc chromate | 9.5 40 | Zinc and barium chromate | 9.5 51 | Black oxide of iron | 9.5 4 | Sublimed white lead | 9.0 44 | Prussian blue | 9.0 5 | Sublimed blue lead | 8.8 20 | Willow charcoal | 8.8 222 | Composite paint | 8.8 45 | Prussian blue | 8.5 111 | Composite formula | 8.5 9 | Orange mineral | 8.3 10 | Red lead | 8.3 555 | Composite paint | 8.2 12 | Bright red oxide of iron | 8.1 2000 | 1 coat zinc chromate; 1 coat iron oxide | 8.1 14 | Venetian red | 8.0 888 | Composite paint | 8.0 =====+=============================================+======= =Comparison of Results.= It is of interest to compare with Table 2 of the above report, Table 2 of the 1910 report of Committee U of the American Society for Testing Materials. Both charts show the highly inhibitive pigments to be in the lead. COMMITTEE U REPORT 1910 TABLE II.--ANALYSIS OF AVERAGES. GRADE OF EXCELLENCE FROM 8 TO 10 (_Only resistance to corrosion was considered, and only pigments which were common to both tests are included_) ===+====================================+======= No.| Pigment |Average ---+------------------------------------+------- 34 | American vermilion (chrome scarlet)| 9.8 41 | Chrome green (blue tone) | 9.7 40 | Zinc and barium chromate | 9.7 5 | Sublimed blue lead | 9.6 4 | Sublimed white lead | 9.5 49 | Zinc and lead chromate | 9.5 39 | Zinc chromate | 9.4 12 | Bright red oxide | 9.3 44 | Prussian blue (water stimulative) | 9.2 16 | Natural graphite | 9.1 9 | Orange mineral (American) | 9.0 36 | Medium chrome yellow | 9.0 2 | White lead (quick process) | 8.9 20 | Willow charcoal | 8.8 45 | Prussian blue (water inhibitive) | 8.8 1 | White lead (Dutch process) | 8.7 10 | Red lead | 8.7 7 | Zinc lead white | 8.0 ===+====================================+======= The writer has recently made a careful inspection of the panels painted with single pigment paints, and has made the following brief summary of the characteristic appearance of each. =Panel No. 1--Dutch Process White Lead.= The excessive chalking which took place began to disappear at the end of a year, being washed away by the rains and carried away by the winds, so that there was left upon the surface but a thin coating of pigment, insufficient to give good protection. Slight corrosion was apparent beneath the film. =Panel No. 2--Quick Process White Lead.= In the same condition as Panel No. 1. =Panel No. 3--Zinc Oxide.= Panel covered with thin lateral streaks of rust, due to the admittance of moisture in cracks caused by brittleness of film. Result doubtless due to insufficient amount of oil used with pigment. Removal of film shows steel very bright except where cracks have formed. =Panel No. 4--Sublimed White Lead.= Although sublimed white lead chalked very heavily, the chalked pigment seemed to be tenacious and adhered to the plate, presenting an excellent surface with absence of rust. Film of good color and quite elastic. =Panel No. 5--Sublimed Blue Lead.= In same condition as Panel No. 4, but color has slightly faded. =Panel No. 6--Lithopones.= Lithopone was early destroyed, as is usual with this pigment when used alone on exterior surfaces. It became rough and discolored, presenting a very blotchy appearance and disclosed the formation of rust working through the film. =Panel No. 7--Zinc Lead White.= In general good condition with the exception of the color, which is slightly dark. Medium chalking was apparent but only very slight corrosion appeared. =Panel No. 9--Orange Mineral.= In excellent condition, showing a good firm surface with no checking or corrosion apparent. Shortly after exposure the film became covered with a white coating of carbonate of lead, which indicates action of the red lead with the carbonic acid of the atmosphere. Removal of this white coating with water discloses the brilliant color of the unaffected portion of the red lead. =Panel No. 10--Red Lead.= In same condition as Panel No. 9. =Panel No. 12--Bright Red Iron Oxide.= In general good condition. Film intact and unfading in color. =Panel No. 14--Venetian Red.= Similar to Panel No. 12, but slight corrosion apparent beneath, in localized spots, and film showing slight wart-like formations. =Panel No. 15--Prince's Metallic Brown.= Similar to Panel No. 14. =Panel No. 16--Natural Graphite.= Deeply pitted in spots, showing bulbous eruptions, indicating the stimulative nature of this pigment. =Panel No. 17--Artificial Graphite.= In same condition as Panel No. 16. =Panel No. 19--Lampblack and Barytes.= Although the film seems to be intact, there are apparent abrasions of the surface showing stimulative corrosion effects of a pronounced nature. =Panel No. 21--Carbon Black and Barytes.= In same condition as Panel No. 19. [Illustration: Corrosion Pits on Graphite Panel] [Illustration: Rust on Stripped Graphite Film] [Illustration: Section of Wire Painted with a Stimulative Carbonaceous Paint] [Illustration: Corroded and Pitted Surface of Plate Painted with Stimulative Paint] The longevity of lampblack and carbon black paint films when applied to wood has been attributed to the slow drying nature of these pigments when mixed with oil. It is assumed that they have the property of keeping the oil in a semi-drying condition, which will not disintegrate as early as when the oil is thoroughly dried to linoxyn. If this is true, it would seem advisable to use with hard-drying pigments, a proportion of some oil that is semi-drying in nature or one which will leave a film not too hard. Soya bean oil, wood oil, and fish oil present themselves as candidates for such use. How they will work in practice, however, is a question not yet determined. On the other hand, it is well known that these pigments require enormous quantities of oil in order to grind to a working consistency, and it is possible that the life of such coatings is due rather to the property of these pigments, of taking up large quantities of oil, than to their effect upon the slow drying of oil. Excessive oil carrying, however, should be avoided, as shown by the early failure and pitting of those carbon black and lampblack paints ground with very large quantities of oil, as is the usual practice. When these carbon and lampblack pigments were ground with barytes (which is a heavy pigment and requires only about 9 pounds of oil to 100 pounds of pigment, as against 175 pounds of oil to 100 pounds of lampblack), it was found that the lampblack and carbon black paints were reinforced and made more suitable for actual practice. The stimulative nature of these black pigments, however, asserted itself in both cases, and large pittings and eruptions were evident at the end of a year. Carbon black, lampblack, graphite, or any other good conductor of electricity should never be placed next to the surface of iron. They are good as top-coatings, but not as prime-coaters. Some pigments are stimulators of corrosion, because they contain water-soluble impurities that hasten the rusting, while others, like graphite, hasten it simply because, being good conductors, they stimulate surface electrolysis. =Panel No. 20--Willow Charcoal.= In excellent condition throughout. Presence of small quantities of potash may be responsible for the inhibitive nature of this black pigment. =Panel No. 24--Ochre.= While the film seems intact, it has a very mottled appearance and examination shows eruptions of rust through the film, in several places. =Panel No. 27--Natural Barytes.= Within a year the film became pin-holed, and corrosion was apparent. At the end of three years very little of the pigment was left upon the plate, having chalked and scaled off. Barytes has proved its usefulness as a constituent of a combination type of paint, but it should not be used alone. =Panel No. 28--Blanc Fixe.= In the same condition as Panel No. 27, but slightly more chalking and disintegration was shown. [Illustration: Panel Painted with Blanc Fixe. Right Side Stripped of Paint to Show Corrosion] [Illustration: Scaled Whiting Films Chemically Active Pigments and Their Effect After Eighteen Months' Wear] [Illustration: Plate Showing Effect of Chemically Active Pigments on Oil after One Year's Wear] =Panel No. 29--Whiting.= Plates coated with calcium carbonate or whiting in oil presented a very fair appearance at the start of the test, but they soon began to chalk and disintegrate. It is well known that whiting, being alkaline, has the property of acting on oil and causing its early disintegration by saponification. As a matter of fact, six months after the whiting plates were exposed, crumbling of the surface appeared, and twelve months was sufficient for the total destruction of the paint. At this time the rusted surface of the plates which had been painted with calcium carbonate, seemed not to rust as fast as those plates which were exposed without paint coatings, and the rust which had formed appeared to be of an even, fine texture. On the lower left-hand corner of these plates had been lettered the figures "29" and "30," using lampblack in oil. One of the most remarkable things which appears on the fence to-day is the perfect condition of these lampblack letters over their priming coat of calcium carbonate, standing out in clear relief against the rusted metal. This test would suggest, therefore, that if the surface of metal is properly protected with a pigment which is slightly alkaline or inhibitive in nature, and then topped with a good weather-resisting material, such as lampblack, graphite or carbon black, good results would be obtained. Further tests will be made to determine the value of this suggestion. =Panel No. 30--Precipitated Calcium Carbonate.= Showed more rapid destruction than Panel No. 29. [Illustration: Corrosion Adhering to Film Stripped from Panel Painted with Gypsum (Calcium Sulphate)] =Panel No. 31--Calcium Sulphate.= Under the paint film of gypsum, rust soon appeared, showing that the film was not a good excluder of moisture. Although the film remained intact, rusting progressed throughout the test and considerably darkened the color of the paint. =Panel No. 32--China Clay.= This pigment gave excellent service for eighteen months. Afterwards indications of corrosion were shown, and apparent breakdown of the film was indicated. [Illustration: China Clay Asbestine Gypsum] =Panel No. 33--Asbestine.= In the same condition as Panel No. 32. [Illustration: Excellent Surface shown by American Vermilion after nearly Four Years' Exposure] =Panel No. 34--American Vermilion.= This pigment has given perfect protection to the plates. The film is strong and elastic, and upon removal reveals the bright steel. No chalking, checking, discoloration, or other signs of paint failure are shown. It would appear that the inhibitive characteristics of this pigment are pronounced, and it promises to give efficient service for several years more. =Panel No. 36--Lead Chromate.= This panel is in generally fair condition, but slight checking is shown. [Illustration: Perfect Condition of Plate Painted with Zinc Chromate; One Half Stripped. (_Negative cracked_)] =Panel No. 39--Zinc Chromate.= This panel is in condition similar to Panel No. 34, presenting a perfect appearance, with decided maintenance of color, elasticity of film, and freedom from any bad characteristics. It has proved to be one of the highest type rust inhibitive pigments. =Panel No. 40--Zinc-and-Barium-Chromate.= Although the color of this pigment is not very pleasing, it has proved itself to be the equal of zinc chromate in its protective value. =Panel No. 41--Chrome Green.= In excellent condition. Presents an appearance similar to Panels Nos. 34 and 39. Its surface is perfect and will doubtless give service for many years. =Panel No. 44--Prussian Blue.= This panel stands forth as the most wonderful moisture-excluder in the whole test, its surface presenting an appearance similar to a varnished plate, even after three years' exposure. Action between the pigment and the oil, resulting in the formation of iron linoleate, may account for this property. =Panel No. 45--Prussian Blue.= In same condition as Panel No. 44. =Panel No. 48--Ultramarine Blue.= Soon after this test was exposed, early vehicle decay and excessive chalking were observed. The admittance of moisture may have caused the formation of acid with the sulphur content of the pigment, which would account for the rapid corrosion which followed. It is of a pronounced stimulative type. The effect of stimulative under-coatings is well shown on some special plates on the fence, which when received were not pickled before painting, but had upon their surfaces the ordinary coating of mill scale. Over this had been stencilled in a triangular form the trade mark of the manufacturer. The stencilling material was made of ultramarine blue. When these plates were painted with some of the special paints, and exposed, the stimulative nature of the ultramarine blue began to assert itself, and within a short time, wherever the stencil marks were located, signs of rust began to appear through the coatings of top paint which had been applied. Corrosion under these stencil marks became so great that the trade mark was plainly outlined in letters of rust. This would seem to be final proof that pigments of a stimulative nature should never be used for the priming of iron and steel. =Panel No. 49--Zinc-Lead Chromate.= In excellent condition throughout, with a smooth surface and showing no corrosion. Stands in the same class as Panels Nos. 34 and 39. [Illustration: Effect of Stimulative Paint. Manufacturer's Trade Mark Stencilled on Bare Metal in Triangular Form, showing Through Subsequent Paint Coating] =Panel No. 51--Black Magnetic Oxide of Iron.= In excellent condition. CHAPTER XVII THE SANITARY VALUE OF WALL PAINTS =Decoration and Sanitation.= The proper decoration of the interior of dwellings and public buildings has become of even greater importance than the protection and decoration of exteriors. There is, moreover, an increasing demand for harmonious effects and the production of more sanitary conditions than have prevailed in the past. Up until a few years ago a great variety of wall papers of more or less pleasing appearance were almost exclusively used for the decoration of walls in the interior of buildings, and their application was commonly considered the most effective means of wall decoration. There seems to be no question, however, that the use of wall paper is steadily decreasing, and that the art of interior decoration is undergoing a transition to the almost universal use of paint. Modern progress demands the maintenance of sanitary conditions for the benefit of the public welfare, and there is no doubt that from the standpoint of sanitation and hygiene, properly painted wall surfaces are far superior to papered walls. There is an abundance of evidence which shows that dust germs may easily be harbored, and thus disease transmitted from wall paper. In the tenement houses, which are common to the larger cities, and to a lesser extent in the dwellings found in smaller communities, where tenants are more or less transient, the continued maintenance of sanitary conditions presents a difficult problem. Infectious and epidemic illnesses generally leave behind bacilli of different types, which may find a culture medium in the fibrous and porous surfaces presented by wall paper, backed up as they invariably must be by starch, casein, or other organic pastes. Occasionally the restrictions of local boards of health provide in such events for proper fumigation, but too often no precautions are taken to destroy the disease germs which are caught in the dust which collects on wall paper. As a rule, both tenant and landlord are oblivious to all conditions which cannot be readily seen or detected. Burning sulphur, one of the most effective means of fumigation, will generally cause bleaching and consequent fading of the delicate colors used in printing the designs upon wall paper. Washing of the paper with antiseptic solutions will destroy its adhesiveness to the plaster and often cause bulging and general destruction. [Illustration: Heavy Colonies of Bacteria Developing in Agar Jelly Treated with Washings from Wall Paper Practically no Development of Bacterial Colonies in Agar Jelly Treated with Washings from Sanitary Wall Paint] =Hospital Practice.= In hospitals, where it is necessary to maintain sanitary conditions, the walls are invariably painted, and requirements should demand the use of paints which can be washed frequently, so that there will be no possibility of uncleanliness. Inquiry made of a prominent surgeon[41] connected with one of the large metropolitan hospitals substantiated the writer's findings regarding the greater sanitary value of wall paints, and brought forth the information that in hospitals under construction provision had been made for the finishing of walls so that a hard, non-absorbent, and washable surface might be obtained. The same authority stated that the common practice, in apartments and tenements, of covering the old wall paper over with a layer of new each time a tenant moved in, should be condemned, and that from a hygienic standpoint the use of sanitary wall paints should be advocated in all dwellings as well as public buildings. [41] Dr. F. F. Gwyer, Cornell Uni. Med. Col., New York City. If such conditions are maintained in hospitals, where special attention is paid to sanitation, it would appear that similar precautions should be equally as necessary in public buildings and in dwellings--wherever, in fact, people congregate or live. =Sanitary Wall Paints.= There have recently appeared in trade a number of wall paints composed of non-poisonous pigments ground in paint vehicles having valuable waterproofing and binding properties, and of a nature to produce the flat or semi-flat finish that has become so popular. Such paints produce a sanitary, waterproof surface, which permits of frequent washing. By their use it is possible to secure a more permanent and a wider range of tints than can be obtained with wall paper, as they are produced in a myriad of shades, tints and solid colors, from which any desired combination may be selected. On the border or on the body of walls decorated with such paints, attractive stencil designs, which bring out in relief the color combinations, may be applied. For the decoration of chambers and living rooms, delicate French grays, light buffs, cream tints and ivory whites may be used, while in the library and other rooms richer and more solid colors, such as greens, reds, and blues, may be harmoniously combined. =Defects of Wall Paper.= It recently occurred to the writer to investigate the conditions which obtain in many apartment houses in the larger cities. Inspection of a number of such places, in which wall paper had been exclusively used on the walls, showed generally bad conditions; bulging of the surfaces, caused by dampness in the walls, which had loosened up the binder, as well as peeling and dropping of the paper from the ceilings, were frequently observed. In many cases a shabby appearance was shown, accompanied by an odor which suggested decomposition of the paste binder used on the paper. The writer was impressed with the fact that such conditions could easily be avoided by the very simple expedient of using properly manufactured wall paints, which are so easily made dustproof and waterproof. Samples of wall paper, which had been applied to plastered walls for a year or more, were obtained, and examination under the microscope showed a most uncleanly surface. Cultures were made of these samples, and bacilli of different types were developed in the culture medium in a short time. =Experimental Evidence.= That the above conditions could not have existed, had proper wall paints been used, seemed doubtless, and suggested a carefully conducted experiment to prove the relative sanitary values of wall paper and wall paints. A large sheet of fibre board, such as is occasionally used to replace plastered walls, was painted on one side with a high-grade wall paint, three-coat work. A similar sheet was papered on one side with a clean, new wall paper. These test panels were placed where unsanitary conditions, such as dampness, foul odors, and a scarcity of air were present. After a short period of exposure, the panels were taken to the bacteriological laboratory and a small section of the painted surface, about two inches square, as well as a small section of the papered surface of similar size, were removed and used for making cultures. In each case the surface of the section under test was washed with 100 c.c. of distilled, sterilized water. The washings which dripped from the surface were collected in a graduated flask. One c.c. of the washings was used in each case, admixed with bouillon and again with agar-agar. The enormous development of bacteria in the bouillon, treated with the washings from the wall-papered surface, was sufficient evidence to convince one of the greater sanitary value of the wall paint, the washings from which gave a culture practically free from bacteria. The colonies of bacteria shown in the petri-dish test made of the washings from wall paper further supports these findings. It will be noticed that the tests made from the washings of the wall paint show practical absence of bacteria, and was clear, as was the bouillon-solution test of the paint. The washings from the wall paper showed active development of bacteria, both in the bouillon and agar tests. [Illustration: DEVELOPMENT OF BACTERIA IN BOUILLON SOLUTIONS Note Practical Freedom of Bacteria in Clear Bouillon Solution Treated with Washings from Sanitary Wall Paint Note Milky Appearance of Solution Due to Heavy Development of Bacteria in Bouillon Treated with Washings from Wall Paper] _From the Conservation Standpoint_: It would be of interest to sum up in figures the acreage and cordage of wood that annually is transformed into pulp for the manufacture of wall paper. Unfortunately, there are no available statistics on this subject. It is clear, however, that from the standpoint of conservation the use of wall paints should take precedence over the use of wall paper. INDEX PAGE Abrasion, apparatus for determining resistance to, 153 Acid reacting compounds, 215 Actinic light tests, 112 Adhesive power of Paint Coating, 104 Aluminum Silicate, 62 American Vermilion, 64 Analogies of Paint and Concrete manufacture, 94 Analyses of Averages in Atlantic City steel paint test, 235, 236 Corn Oil, 16 Cottonseed Oil, 15 Debloomed Mineral Paint Oil, 18 Iron Oxide Pigments, table, 63 Linseed Oil, 7 Menhaden Oil, 14 Oils used in Washington tests, 211 Petroleum Spirits, 20 Rosin Oil, 16 Soya Bean Oil, 8 Sunflower Oil, 15 Tung Oil, 12 Whale Oil, 14 Wood Turpentine, 19 Asbestine, 55 Atlantic City fence tests, 107 steel paint tests, 228-235 Checking, 122 Gloss, 122 Hiding power, 122 inspection of, 114 Methods used, 114 Results, 124 Auto-electrolysis, 220 Bacteria in wall paper, 256 Barium Sulphate, 55 Barytes, 55 and Silica Paints in Pittsburg tests, 172 Basic Carbonate-White Lead, 42 Benzine, 20 Benzol, 20 Blanc Fixe, 60 Blue Lead, Sublimed, 47 Blue Paint for concrete wall, formula, 215 Blue paints in Pittsburg tests, 142 Boiled Linseed Oil, 2 Driers in, 28 Bone Black, 66 Calcium Carbonate, 60 Calcium Sulphate, 60 Carbon Black, 66 Cause of rust in steel work, 220 Chalking test for laboratory, 149 Checking and cracking in Pittsburg tests, 166 Checking, in Atlantic City tests, 122 China Clay, 62 Chrome Green, 66 Chrome Yellow, 64 Coatings for cement and concrete, 214 Colored formulas in North Dakota tests, 190 Colors, report of, in Pittsburg tests, 139 Combination formulas in inhibitive paints, 231 Composite formulas in North Dakota tests, 190 in Pittsburg tests, 142 Composition of paints, in steel test, 232 Conclusion from Pittsburg tests, 144 Concrete primer formula, 218 Constants of Pine Oil, 18 Pure Gum Turpentine, 19 Co-operative tests of Driers, 29-41 Corn Oil, 16 Cottonseed Oil, 15 Damp-proofing and Waterproofing, 214 Decay of Lithopone paints, 124 Decomposition of Paint, 122 Driers, Co-operative tests of, 29-41 in Boiled Oil, 28 Tests of Manganese, Lead and Combination, tables, 24-25 Drying Properties of Oil, 1, 26, 27 Elasticity and Strength of Paint Coating, 102 Fence tests of paints, 105 Supervision of, 112 Film sectioning, 87 Film testing results, table, 80 Filmometers, 74-79 Formula for Blue Paint for concrete wall, 215 Concrete primer, 218 Para Red Paint for concrete wall, 217 Formulas of Atlantic City fence test, 108 Tennessee tests, 202, 204 Washington tests, 208, 211 Fume Pigments Paints in Pittsburg tests, 173 General results of Atlantic City tests, 128 Gloss, in Atlantic City tests, 122 Graphite, 66 Green paints in Pittsburg tests, 142 Grinding Pigments, 87 Gums as moisture resisters, 84 Gypsum, 60 Hailstorm, effects of in North Dakota tests, 185 Hospital, painting practice, 254 House paint tests in North Dakota, 196 Hydrocarbon Oils, 16 Imperviousness of paint coating, 100 Indian Red, 62 Inert Pigments, use of, 99 Inhibition of rust, 222 Iodine Values of Linseed and Mixed Oils, table, 8 Iron Oxide Paints, 64 Japan driers in tests on steel, 231 Laboratory tests, panels for, 149 Lampblack, 66 Laws of Paint Making, 93 Lime action on paint, 214 Linoxyn, 21 Linseed Oil, boiled, 2 Chemical action of pigments upon, 91 Table of Analyses of Various Types of, 7 tests of Driers with, 24, 25 Lithopone, 53 paint in Pittsburg tests, 136 tests at Atlantic City, 124 Lumbang Oil, 12 Magnesium Silicate, 55 Manufacturing Barytes, 55 Blue Lead, 47 Bone Black, 66 Paint Pigments, 42-68 White Lead, 42 Menhaden Oil, 12 Constants of, table, 14 Metallic Brown, 62 Microscope, use of in paint laboratory, 86 Microscopic examination of paint, preparation for, 86 measurements of paint sections, 89 Mineral Black, 68 Oils, 17 Moisture Absorption, tests in, 84 experiments with various Pigments, 83 North Dakota Paints tests, 182 test fence, 105 report of, table, 193-195 Ochre, 62 Oil and Thinner tests, 202 Oil, Corn, 16 Cottonseed, 15 Effects of Pigments on, 90 Linseed, 1 Linseed, Analyses of Various Types of, table, 7 Linseed, Iodine Values of, table, 8 Linseed, Tests of Driers with, 24, 25 Lumbang, 12 Menhaden, 12 Menhaden, Constants of, table, 14 Perilla, 21 Pine, 18 Rosin, 16 Soya Bean, and Driers, table, 9 Soya Bean, 7 Chemical Characteristics of, table, 8 Sunflower, 14 Tung, 9 Whale, 14 Oils, Constants and Characteristics of, 1 Drying properties of, 1, 26 Hydrocarbon, 16 In Washington paint tests, 210 Iodine Value of Linseed and Mixed, table, 8 Mineral, 17 Moisture resistance of, 84 Oxygen Absorbing qualities, 21 Outline of tests of paints on concrete walls, 216 Oxygen Absorption in Oils, 21 Paint Coating, Adhesive power of, 104 Elasticity and Strength of, 102 imperviousness of, 100 decomposition of, 122 films, action of water upon, 223 permeability of, 71 Testing machine, 74 preparation of, 70 in Hospitals, 254 making, Laws of, 93 Perry's Principles of, 100 pigments, 42-69 pigments, properties of, 42 preparation for microscopic examination of, 86 tests at North Dakota Experiment Station, 105 at Washington, 207-213 supervisors of, 113 woods used on, 124, 135 Painting steel plates for tests, 230 Paints for cement and concrete surfaces, 214 composition of in steel test, 233 hiding power of, 111 sanitary value of, 252 Panels for laboratory tests, 149 Para Red formula for concrete wall, 217 Paranitraniline paints in Pittsburg tests, 140 Paranitraniline Red, 64 Perilla Oil, 21 Perry's analogies of paint and concrete manufacture, 99 principles of Paint Making, 100 Petroleum Spirits, 20 Photomicrographs, 89, 165 Pigment contention, the, 105 grinding, 87 Pigments, 42-69 as stimulators of rust, 223 Chemical action of upon Linseed Oil, table, 91 Effects of on Oil, 90 inert, use of, 99 moisture experiments with, table, 83 percentages of Oil required for grinding, 68 re-enforcing, 89 report of results of steel paint tests, 236-251 Water resistance of, 81 Pine Oil, 18 Pittsburg fence tests, 107 Polar Micro-Examinations and Photomicrographs, 89 Primer for concrete, 218 Properties of Paint Pigments, 42 Prussian Blue, 66 Red Lead, 64 Reductions used in fence tests, 111 Re-enforcing Pigments, 89 Results of new test at Atlantic City test fence in 1910, table, 178-181 Pittsburg tests, 135 steel test plates, 232 Rosin Oil, 16 Rust, cause of in steel work, 220 inhibition of, 222 stimulation of, 223 Sanitary value of paints, 252 wall paints, 254 Sienna, 62 Silex, 60 Silica, 60 Silica and Barytes Paints in Pittsburg tests, 172 Solvent Naphtha, 20 Soya Bean Oil and Driers, table, 9 Chemical Characteristics of, table, 8 Steel Paint test, rating report, 234 reports on pigments used, 236-251 Steel paint, result of tests at Atlantic City, 234, 235 Steel, preparation of for paint tests, 228 water contact and paint, 224 Structural steel paint tests, 220 Sublimed Blue Lead, 47 Sublimated White Lead, 46 Suction varnish, 215 Sunflower Oil, 14 Constants of, table, 15 Supervisors of paint tests, 113 Table Analysis of Averages in Atlantic City Steel Paint test, 235, 236 Analyses of Corn Oil, 16 Analyses of Debloomed Mineral Paint Oil, 18 Analysis of Iron Oxide Pigments, 63 Analyses of Oils used in Washington tests, 211 Analyses of Petroleum Spirits, 20 Analyses of Rosin Oil, 16 Analyses of various types of Linseed Oil, 7 Analyses of wood Turpentine, 19 Atlantic City test fence formula, 108 Chemical Characteristics of Soya Bean Oil, 8 Comparative spreading rates of White Paint in Pittsburg tests, 148 Composition of Blue Lead, 49 Composition of paints in Atlantic City Steel test, 233 Constants of Cottonseed Oil, table, 15 Constants of Menhaden Oil, 14 Constants of Pine Oil, 18 Constants of Sunflower Oil, 15 Constants of Whale Oil, 14 Co-operative drying tests, 32-41 Excluding tests for moisture absorbed, 84 Fineness for grinding pigments, 87 Formulas in Tennessee tests, 204 Iodine Value of Linseed Oil and Mixed Oils, 84 Moisture experiments with various pigments, 83 Paint section measurements under microscope, 89 Percentages of Oil required for grinding various dry pigments, 68 Permeability of Paints, 72 Ratings of Atlantic City Steel Paint test, 234 Report of North Dakota test fence, 193-195 Results of Atlantic City test fence, 130, 131 Results of new tests at Atlantic City test fence in 1910, 178-181 Results of second annual inspection Atlantic City test fence, 133 Results of second annual inspection in Pittsburg tests, 145 Showing action of various pigments upon Linseed Oil, 91 Soya Bean Oil and Driers, 9 Tests of Linseed Oil and Manganese, Lead and Combination Driers, 24, 25 Talcose, 55 Tennessee Paint tests, 201-206 Test Fences in Paint Experiments, 105 at Atlantic City, 114-134 at Pittsburg, 135-148 at Washington, 207-213 Cement and concrete, 214 in Tennessee, 201-206 laboratory, chalking, 149 North Dakota, 182 of Oil and Thinners, 202 of various pigments in steel paint, 236-251 panel sections for, 149 Structural steel paints, 220 Water pigment, 226 Thinner, Wood Turpentine as a, 202 Tung Oil, 9 Tung Varnishes, 11 Turpentine, 18 Ultramarine Blue, 66 Umber, 62 Varnishes from Tung Oil, 11 Vermilion, American, 64 Wall paints, 252 Wall paper, defects of, 255 Washington Paint tests, 207-213 Water, action of upon paint films, 223 contact with steel and paint, 224 resistance of Pigments, 81 tests, 226 Water-pigment tests, 226 Waterproofing and damp-proofing, 214 Whale Oil, 14 White Lead, Basic Carbonate, 42 Basic Sulphate, 46 Mild Process, 46 Quick Process, 45 in Pittsburg tests, 139 in North Dakota tests, 190 Paints, checking in Pittsburg tests, 172 processes of manufacture of, 43-46 Whiting, 60 Wood Turpentine, 19 experiments with as a thinner, 202 Woods used in paint tests, 124, 135 Zinc Chromate, 64 Zinc Lead White, 51 Zinc Oxide, 51 +------------------------------------------------------------------+ | TRANSCRIBER'S NOTES: | | | | * Page 25, Table VIII: the table header row contains duplicate | | values which may be a typographical error. | | * Pages 86 and 87: two section titles are followed by numbers | | without any obvious reason. These have not been deleted. | | * The original spelling (including hyphenation) has been | | preserved, except as indicated below. Some minor inconsisten- | | cies and typographical errors have been corrected silently. | | * Changes made to the text: | | * Page 26: 'as discolored and turned brown' changed to 'was | | discolored and turned brown'. | | * Page 87, table 3rd row: '0.00067--' changed to '0.00067'. | | * Page 94, exposition: some elements re-arranged for better | | readability. | | * Page 124: the note at the bottom of the page has been moved | | to directly underneath the first paragraph. | | * Page 130: 'MacNichol' changed to 'Macnichol' as elsewhere. | | * Page 137 (caption): 'Pittsburgh' changed to 'Pittsburg' as | | elsewhere in text (and in illustration itself). | | * Page 142: 'prussian blues' changed to 'Prussian blues'. | | * Page 177: 'pages 174 to 177' changed to 'pages 178 to 181'. | | * Page 211: one footnote anchor changed from '*' to '[32]' as | | others in row. | | * Page 230, formula: '4500' changed to '5400'. | | * Page 234, table: row for Panel No. 2000: '}' inserted for | | combined rows. | | * Index: changed to agree with text: 'determinating' to | | 'determining', 'Derbloomed' to 'Debloomed', 'Filometers' to | | 'Filmometers', 'Parilla Oil' to 'Perilla Oil'. 'Grinding | | Pigments' moved to proper alphabetic location. | | | +------------------------------------------------------------------+ 
16378	----	Transcriber's note: Footnotes moved to end of text The Art OF PERFUMERY, AND METHOD OF OBTAINING THE ODORS OF PLANTS. [Illustration: DRYING HOUSE FOR HERBS.] From the rafters of the roof of the Drying House are suspended in bunches all the herbs that the grower cultivates. To accelerate the desiccation of rose leaves and other petals, the Drying House is fitted up with large cupboards, which are slightly warmed with a convolving flue, heated from a fire below. The flower buds are placed upon trays made of canvas stretched upon a frame rack, being not less than twelve feet long by four feet wide. When charged they are placed on shelves in the warm cupboards till dry. THE ART OF PERFUMERY, AND METHOD OF OBTAINING THE ODORS OF PLANTS, WITH INSTRUCTIONS FOR THE MANUFACTURE OF PERFUMES FOR THE HANDKERCHIEF, SCENTED POWDERS, ODOROUS VINEGARS, DENTIFRICES, POMATUMS, COSMETIQUES, PERFUMED SOAP, ETC. WITH AN APPENDIX ON THE COLORS OF FLOWERS, ARTIFICIAL FRUIT ESSENCES, ETC. ETC. [Illustration] BY G.W. SEPTIMUS PIESSE, AUTHOR OF THE "ODORS OF FLOWERS," ETC. ETC. * * * * * PHILADELPHIA: LINDSAY AND BLAKISTON. 1857. PRINTED BY C. SHERMAN & SON, 19 St. James Street. Preface. By universal consent, the physical faculties of man have been divided into five senses,--seeing, hearing, touching, tasting, and smelling. It is of matter pertaining to the faculty of Smelling that this book mainly treats. Of the five senses, that of smelling is the least valued, and, as a consequence, is the least tutored; but we must not conclude from this, our own act, that it is of insignificant importance to our welfare and happiness. By neglecting to tutor the olfactory nerve, we are constantly led to breathe impure air, and thus poison the body by neglecting the warning given at the gate of the lungs. Persons who use perfumes are more sensitive to the presence of a vitiated atmosphere than those who consider the faculty of smelling as an almost useless gift. In the early ages of the world the use of perfumes was in constant practice, and it had the high sanction of Scriptural authority. The patrons of perfumery have always been considered the most civilized and refined people of the earth. If refinement consists in knowing how to enjoy the faculties which we possess, then must we learn not only how to distinguish the harmony of color and form, in order to please the sight, the melody of sweet sounds to delight the ear; the comfort of appropriate fabrics to cover the body, and to please the touch, but the smelling faculty must be shown how to gratify itself with the odoriferous products of the garden and the forest. Pathologically considered, the use of perfumes is in the highest degree prophylactic; the refreshing qualities of the citrine odors to an invalid is well known. Health has often been restored when life and death trembled in the balance, by the mere sprinkling of essence of cedrat in a sick chamber. The commercial value of flowers is of no mean importance to the wealth of nations. But, vast as is the consumption of perfumes by the people under the rule of the British Empire, little has been done in England towards the establishment of flower-farms, or the production of the raw odorous substances in demand by the manufacturing perfumers of Britain; consequently nearly the whole are the produce of foreign countries. However, I have every hope that ere long the subject will attract the attention of the Society of Arts, and favorable results will doubtless follow. Much of the waste land in England, and especially in Ireland, could be very profitably employed if cultivated with odor-bearing plants. The climate of some of the British colonies especially fits them for the production of odors from flowers that require elevated temperature to bring them to perfection. But for the lamented death of Mr. Charles Piesse,[A] Colonial Secretary for Western Australia, I have every reason to believe that flower-farms would have been established in that colony long ere the publication of this work. Though thus personally frustrated in adapting a new and useful description of labor to British enterprise, I am no less sanguine of the final result in other hands. Mr. Kemble, of Jamaica, has recently sent to England some fine samples of Oil of Behn. The Moringa, from which it is produced, has been successfully cultivated by him. The Oil of Behn, being a perfectly inodorous fat oil, is a valuable agent for extracting the odors of flowers by the maceration process. At no distant period I hope to see, either at the Crystal Palace, Sydenham, at the Royal Botanical Gardens, Kew, or elsewhere, a place to illustrate the commercial use of flowers--eye-lectures on the methods of obtaining the odors of plants and their various uses. The horticulturists of England, being generally unacquainted with the methods of economizing the scents from the flowers they cultivate, entirely lose what would be a very profitable source of income. For many ages copper ore was thrown over the cliffs into the sea by the Cornish miners working the tin streams; how much wealth was thus cast away by ignorance we know not, but there is a perfect parallel between the old miners and the modern gardeners. Many readers of the "Gardeners' Chronicle" and of the "Annals of Pharmacy and Chemistry" will recognize in the following pages much matter that has already passed under their eyes. To be of the service intended, such matter must however have a book form; I have therefore collected from the above-mentioned periodicals all that I considered might be useful to the reader. To Sir Wm. Hooker, Dr. Lindley, Mr. W. Dickinson, and Mr. W. Bastick, I respectfully tender my thanks for the assistance they have so freely given whenever I have had occasion to seek their advice. Contents. PREFACE SECTION I. INTRODUCTION AND HISTORY. Perfumes in use from the Earliest Periods--Origin lost in the Depth of its Antiquity--Possibly derived from Religious Observances--Incense or Frankincense burned in Honor of the Divinities--Early Christians put to Death for refusing to offer Incense to Idols--Use of perfumes by the Greeks and Romans--Pliny and Seneca observe that some of the luxurious People scent themselves Three Times a Day--Use of Incense in the Romish Church--Scriptural Authority for the use of Perfume--Composition of the Holy Perfume--The Prophet's Simile--St. Ephræm's Will--Fragrant Tapers--Constantine provides fragrant Oil to burn at the Altars--Frangipanni--Trade in the East in Perfume Drugs--The Art of Perfumery of little Distinction in England--Solly's admirable Remarks on Trade Secrets--British Horticulturists neglect to collect the Fragrance of the Flowers they cultivate--The South of France the principal Seat of the Art--England noted for Lavender--Some Plants yield more than one Perfume--Odor of Plants owing to a peculiar Principle known as Essential Oil or Otto SECTION II. Consumption of Perfumery--Methods of obtaining the Odors:--Expression, Distillation, Maceration, Absorption SECTION III. Steam-Still--Macerating Pan--Ottos exhibited at the Crystal Palace of 1851--SIMPLE EXTRACTS:--Allspice, Almond, Artificial Otto of Almonds, Anise, Balm, Balsams, Bay, Bergamot, Benzoin, Caraway, Cascarilla, Cassia, Cassie, Cedar, Cedrat, Cinnamon, Citron, Citronella, Clove, Dill, Eglantine or Sweet Brier, Elder, Fennel, Flag, Geranium, Heliotrope, Honeysuckle, Hovenia, Jasmine, Jonquil, Laurel, Lavender, Lemon-grass, Lilac, Lily, Mace, Magnolia, Marjoram, Meadow-sweet, Melissa, Mignonette, Miribane, Mint, Myrtle, Neroli, Nutmeg, Olibanum, Orange, Orris, Palm, Patchouly, Sweet Pea (Theory of Odors), Pineapple, Pink, Rhodium (Rose yields two Odors), Rosemary, Sage, Santal, Sassafras, Spike, Storax, Syringa, Thyme, Tonquin, Tuberose, Vanilla, Verbena or Vervain, Violet, Vitivert, Volkameria, Wallflower, Winter-green--Duty on Essential Oils--Quantity imported--Statistics, &c. SECTION IV. ANIMAL PERFUMES. Ambergris--Civet--Musk SECTION V. SMELLING SALTS:--Ammonia, Preston Salts, Inexhaustible Salts, Eau de Luce, Sal Volatile ACETIC ACID AND ITS USE IN PERFUMERY.--Aromatic Vinegar, Henry's Vinegar, Vinaigre à la Rose, Four Thieves' Vinegar, Hygienic Vinegar, Violet Vinegar, Toilet Vinegar, Vinaigre de Cologne SECTION VI. BOUQUETS AND NOSEGAYS. Proposed Use of the Term "Otto" to denote the odoriferous Principle of Plants COMPOUND ODORS:--The Alhambra Perfume--The Bosphorus Bouquet--Bouquet d'Amour--Bouquet des Fleurs du Val d'Andorre--Buckingham Palace Bouquet--Délices--The Court Nosegay--Eau de Chypre--The Empress Eugenie's Nosegay--Esterhazy--Ess Bouquet--Eau de Cologne. (French and English Spirit.) Flowers of Erin--Royal Hunt Bouquet--Extract of Flowers--The Guards' Bouquet--Italian Nosegay--English Jockey Club--French Jockey Club. (Difference of the Odor of English and French Perfumes due to the Spirit of Grape and Corn Spirit.) A Japanese Perfume--The Kew Garden Nosegay--Millefleurs--Millefleurs et Lavender--Delcroix's Lavender--Marechale--Mousselaine--Bouquet de Montpellier--Caprice de la Mode--May Flowers--Neptune, or Naval Nosegay--Bouquet of all Nations--Isle of Wight Bouquet--Bouquet du Roi--Bouquet de la Reine Victoria--Rondeletia. (Odors properly blended produce new Fragrances.) Bouquet Royal--Suave--Spring Flowers--Tulip Nosegay--The Wood Violet--Windsor Castle Bouquet--Yacht Club Nosegay SECTION VII. The ancient Perfumes were only odoriferous Gums--Abstaining from the Use of Perfumes a Sign of Humiliation--The Vase at Alnwick Castle--Sachet Powders--Sachet au Chypre--Sachet à la Frangipanne--Heliotrope Sachet--Lavender Sachet--Sachet à la Maréchale--Mousselaine--Millefleur--Portugal Sachet--Patchouly Sachet--Pot Pourri--Olla Podrida--Rose Sachet--Santal-wood Sachet--Sachet (without a name)--Vervain Sachet--Vitivert--Violet Sachet--Perfumed Leather--Russia Leather--Peau d'Espagne--Perfumed Letter Paper--Perfumed Book-markers--Cassolettes, and Printaniers Pastils--The Censer--Vase in the British Museum--Method of using the Censer--Incense for Altar Service--Yellow Pastils--Dr. Paris's Pastils--Perfumer's Pastils--Piesse's Pastils--Fumigation--The Perfume Lamp--Incandescent Platinum--Eau à Bruler--Eau pour Bruler--Fumigating Paper--Perfuming Spills--Odoriferous Lighters SECTION VIII. PERFUMED SOAP. Perfumed Soap--Ancient Origin of Soap--Early Records of the Soap Trade in England--Perfumers not Soap Makers--Remelting--Primary Soaps--Curd Soap--Oil Soap--Castile Soap--Marine Soap--Yellow Soap--Palm Soap--Excise Duty on Soap--Fig Soft Soap--Naples Soft Soap--The remelting Process--Soap cutting--Soap stamping--Scented Soaps Almond Soap--Camphor Soap--Honey Soap--White Windsor Soap--Brown Windsor Soap--Sand Soap--Fuller's Earth Soap--Scenting Soaps Hot--Scenting Soaps Cold--Colored Soaps:--Red, Green, Blue, Brown Soaps--Otto of Rose Soap--Tonquin Musk Soap--Orange-Flower Soap--Santal-wood Soap--Spermaceti Soap--Citron Soap--Frangipanne Soap--Patchouly Soap--Soft or Potash Soaps--Saponaceous Cream of Almonds--Soap Powders--Rypophagon Soap--Ambrosial Cream--Transparent soft Soap--Transparent hard Soap--Medicated Soaps--Juniper Tar Soap--Iodine Soap--Sulphur Soap--Bromine Soap--Creosote Soap--Mercurial Soap--Croton Oil Soap--Their Use in Cutaneous Diseases SECTION IX. EMULSINES. Form Emulsions or Milks when mixed with Water--Prone to Change--Amandine--Olivine--Honey and Almond Paste--Pure Almond Paste--Almond Meal--Pistachio Nut Meal--Jasmine Emulsion--Violet Emulsion SECTION X. MILKS OR EMULSIONS. Liebig's notice of Almond Milk--Milk of Roses--Milk of Almonds--Milk of Elder--Milk of Dandelion--Milk of Cucumber--Essence of Cucumber--Milk of Pistachio Nuts--Lait Virginal--Extract of Elder Flowers SECTION XI. COLD CREAM. Manipulation--Cold Cream of Almonds--Violet Cold Cream--Imitation Violet Cold Cream--Cold Cream of various Flowers--Camphor Cold Cream--Cucumber Cold Cream--Piver's Pomade of Cucumber--Pomade Divine--Almond Balls--Camphor Balls--Camphor Paste--Glycerine Balsam--Rose Lip Salve--White Lip Salve--Common Lip Salve SECTION XII. POMADES AND OILS. Pomatum, as its name implies, originally made with Apples--Scentless Grease--Enfleurage and Maceration process--Acacia, or Cassie Pomade--Benzoin Pomade and Oil--Vanilla Oil and Pomade--Pomade called Bear's Grease--Circassian Cream--Balsam of Flowers--Crystallized Oils--Castor Oil Pomatum--Balsam of Neroli--Marrow Cream--Marrow Pomatum--Violet Pomatum--Pomade Double, Millefleurs--Pomade à la Heliotrope--Huile Antique--Philocome--Pomade Hongroise--Hard or Stick Pomatums--Black and Brown Cosmetique SECTION XIII. HAIR DYES AND DEPILATORIES. Painting the Face universal among the Women of Egypt--Kohhl, the Smoke of Gum Labdanum, used by the Girls of Greece to color the Lashes and Sockets of the Eye--Turkish Hair Dye--Rastikopetra Dye--Litharge Dye--Silver Dye--Hair Dyes, with Mordant--Inodorous Dye--Brown and Black Hair Dye--Liquid Lead Dye--Depilatory, Rusma SECTION XIV. ABSORBENT POWDERS. Violet Powder--Rose Face Powder--Perle Powder--Liquid Blanc for Theatrical Use--Calcined Talc--Rouge and Red Paints--Bloom of Roses--Carmine Toilet Rouge--Carthamus Flowers--Pink Saucers--Crépon Rouge SECTION XV. TOOTH POWDERS AND MOUTH WASHES. Mialhi's Tooth Powder--Camphorated Chalk--Quinine Tooth Powder--Prepared Charcoal--Peruvian Bark Powder--Homoeopathic Chalk--Cuttle-Fish Powder--Borax and Myrrh--Farina Piesse's Dentifrice--Rose Tooth Powder--Opiate Paste--Violet Mouth Wash--Eau Botot--Botanic Styptic--Tincture of Myrrh and Borax--Myrrh with Eau de Cologne--Camphorated Eau de Cologne SECTION XVI. HAIR WASHES. Rosemary Hair Wash--Athenian Water--Vegetable or Botanic Hair Wash--Astringent Extract of Roses and Rosemary--Saponaceous Wash--Egg Julep--Bandolines--Rose and Almond Bandoline Contents of Appendix. Manufacture of Glycerine Test for Alcohol in Essential Oils Detection of Poppy and other drying Oils in Almond and Olive Oil Coloring matter of Volatile Oils Artificial Preparation of Otto of Cinnamon Detection of Spike Oil and Turpentine in Lavender Oil The Orange Flower Waters of Commerce Concentrated Elder Water ARNALL on Spirits of Wine Purification of Spirits by Filtration COBB on Otto of Lemons BASTICK on Benzoic Acid On the Coloring matters of Flowers Bleaching Bees' Wax Chemical Examination of Naples Soap Manufacture of Soap How to Ascertain the Commercial Value of Soap On the Natural Fats Perfumes as Preventives of Mouldiness BASTICK on Fusel Oil BASTICK'S Pine Apple Flavor WAGNER'S Essence of Quince Preparation of Rum-ether Artificial Fruit essences Volatile Oil of Gaultheria Application of Chemistry to Perfumery Correspondence from the Journal of the Society of Arts Quantities of Ottos yielded by various Plants French and English Weights and Measures compared Illustrations. Drying House, Mitcham, Surrey, (Frontispiece.) Smelling, from the Dresden Gallery, (Vignette.) Pipette, to draw off small Portions of Otto from Water Tap Funnel for separating Ottos from Waters, and Spirits from Oil The Almond Styrax Benzoin Cassie Buds The Clove The Jasmine The Orange The Patchouly Plant Santal-Wood Tonquin Vanilla Vitivert Civet Cat Musk Pod Musk Deer The Censer Perfume Lamp Slab Soap Gauge Barring Gauge Squaring Gauge Soap Scoops Soap Press Moulds Soap Plane Oil Runner THE ART OF PERFUMERY. INTRODUCTION AND HISTORY. SECTION I. "By Nature's swift and secret working hand The garden glows, and fills the liberal air With lavish odors. There let me draw Ethereal soul, there drink reviving gales, Profusely breathing from the spicy groves And vales of fragrance."--THOMSON. Among the numerous gratifications derived from the cultivation of flowers, that of rearing them for the sake of their perfumes stands pre-eminent. It is proved from the oldest records, that perfumes have been in use from the earliest periods. The origin of this, like that of many other arts, is lost in the depth of its antiquity; though it had its rise, no doubt, in religious observances. Among the nations of antiquity, an offering of perfumes was regarded as a token of the most profound respect and homage. Incense, or Frankincense, which exudes by incision and dries as a gum, from _Arbor-thurifera_, was formerly burnt in the temples of all religions, in honor of the divinities that were there adored. Many of the primitive Christians were put to death because they would not offer incense to idols. "Of the use of these luxuries by the Greeks, and afterwards by the Romans, Pliny and Seneca gives much information respecting perfume drugs, the method of collecting them, and the prices at which they sold. Oils and powder perfumery were most lavishly used, for even three times a day did some of the luxurious people anoint and scent themselves, carrying their precious perfumes with them to the baths in costly and elegant boxes called NARTHECIA." In the Romish Church incense is used in many ceremonies, and particularly at the solemn funerals of the hierarchy, and other personages of exalted rank. Pliny makes a note of the tree from which frankincense is procured, and certain passages in his works indicate that dried flowers were used in his time by way of perfume, and that they were, as now, mixed with spices, a compound which the modern perfumer calls _pot-pourri_, used for scenting apartments, and generally placed in some ornamental Vase. It was not uncommon among the Egyptian ladies to carry about the person a little pouch of odoriferous gums, as is the case to the present day among the Chinese, and to wear beads made of scented wood. The "bdellium" mentioned by Moses in Genesis is a perfuming gum, resembling frankincense, if not identical with it. Several passages in Exodus prove the use of perfumes at a very early period among the Hebrews. In the thirtieth chapter of Exodus the Lord said unto Moses: "1. And thou shalt make an altar to burn incense upon; of Shittim wood shalt thou make it." "7. And Aaron shall burn thereon sweet incense every morning; when he dresseth the lamps he shall burn incense upon it." "34. Take unto thee sweet spices, stacte, and onycha, and galbanum; these sweet spices with pure frankincense: of each shall there be a like weight." "35. And thou shalt make it a perfume, a confection after the art of the apothecary, tempered together pure and holy." "36. And thou shalt beat some of it very small, and put of it before the testimony in the tabernacle of the congregation, where I will meet with thee; it shall be unto you most holy." "37. And as for the perfume which thou shalt make, ye shall not make to yourselves according to the composition thereof; it shall be unto thee holy for the Lord." "38. Whosoever shall make like unto that to smell thereto, shall even be cut off from his people." "It was from this religious custom, of employing incense in the ancient temples, that the royal prophet drew that beautiful simile of his, when he petitioned that his prayers might ascend before the Lord like incense, Luke 1:10. It was while all the multitude was praying without, at the hour of incense, that there appeared to Zachary an angel of the Lord, standing on the right side of the altar of incense. That the nations attached a meaning not only of personal reverence, but also of religious homage, to an offering of incense, is demonstrable from the instance of the Magi, who, having fallen down to adore the new-born Jesus, and recognized his Divinity, presented Him with gold, myrrh and frankincense. The primitive Christians imitated the example of the Jews, and adopted the use of incense at the celebration of the Liturgy. St. Ephræm, a father of the Syriac Church, directed in his will that no aromatic perfumes should be bestowed upon him at his funeral, but that the spices should rather be given to the sanctuary. The use of incense in all the Oriental churches is perpetual, and almost daily; nor do any of them ever celebrate their Liturgy without it, unless compelled by necessity. The Coptic, as well as other Eastern Christians, observe the same ceremonial as the Latin Church in incensing their altar, the sacred vessels, and ecclesiastical personages."--DR. ROCK'S _Hierurgia_. Perfumes were used in the Church service, not only under the form of incense, but also mixed in the oil and wax for the lamps and lights commanded to be burned in the house of the Lord. The brilliancy and fragrance which were often shed around a martyr's sepulchre, at the celebration of his festival, by multitudes of lamps and tapers, fed with aromatics, have been noticed by St. Paulinus:-- "With crowded lamps are these bright altars crowned, And waxen tapers, shedding perfume round From fragrant wicks, beam calm a scented ray, To gladden night, and joy e'en radiant day." DR. ROCK'S _Hierurgia_. Constantine the Great provided fragrant oils, to be burned at the altars of the greater churches in Rome; and St. Paulinus, of Nola, a writer of the end of the fourth and beginning of the fifth century, tells us how, in his times, wax tapers were made for church use, so as to shed fragrance as they burned:-- "Lumina cerates adolentur odora papyris." A perfume in common use, even to this day, was the invention of one of the earliest of the Roman nobles, named Frangipani, and still bears his name; it is a powder, or sachet, composed of every known spice, in equal proportions, to which is added ground iris or orris root, in weight equal to the whole, with one per cent. of musk or civet. A liquid of the same name, invented by his grandson Mercutio Frangipani, is also in common use, prepared by digesting the Frangipane powder in rectified spirits, which dissolves out the fragrant principles. This has the merit of being the most lasting perfume made. "The trade for the East in perfume-drugs caused many a vessel to spread its sails to the Red Sea, and many a camel to plod over that tract which gave to Greece and Syria their importance as markets, and vitality to the rocky city of Petra. Southern Italy was not long ere it occupied itself in ministering to the luxury of the wealthy, by manufacturing scented unguents and perfumes. So numerous were the UNGUENTARII, or perfumers, that they are said to have filled the great street of ancient Capua."--HOFMANN. As an art, in England, perfumery has attained little or no distinction. This has arisen from those who follow it as a trade, maintaining a mysterious secrecy about their processes. No manufacture can ever become great or important to the community that is carried on under a veil of mystery. "On the subject of trade mystery I will only observe, that I am convinced that it would be far more to the interest of manufacturers if they were more willing to profit by the experience of others, and less fearful and jealous of the supposed secrets of their craft. It is a great mistake to think that a successful manufacturer is one who has carefully preserved the secrets of his trade, or that peculiar modes of effecting simple things, processes unknown in other factories, and mysteries beyond the comprehension of the vulgar, are in any way essential to skill as a manufacturer, or to success as a trader."--PROFESSOR SOLLY. If the horticulturists of England were instructed how to collect the odors of flowers, a new branch of manufacture would spring up to vie with our neighbors' skill in it across the Channel. Of our five senses, that of SMELLING has been treated with comparative indifference. However, as knowledge progresses, the various faculties with which the Creator has thought proper in his wisdom to endow man will become developed, and the faculty of Smelling will meet with its share of tuition as well as Sight, Hearing, Touch, and Taste. Flowers yield perfumes in all climates, but those growing in the warmer latitudes are most prolific in their odor, while those from the colder are the sweetest. Hooker, in his travels in Iceland, speaks of the delightful fragrance of the flowers in the valley of Skardsheidi; we know that winter-green, violets, and primroses are found here, and the wild thyme, in great abundance. Mr. Louis Piesse, in company with Captain Sturt, exploring the wild regions of South Australia, writes: "The rains have clothed the earth with a green as beautiful as a Shropshire meadow in May, and with flowers, too, as sweet as an English violet; the pure white anemone resembles it in scent. The Yellow Wattle, when in flower, is splendid, and emits a most fragrant odor." Though many of the finest perfumes come from the East Indies, Ceylon, Mexico, and Peru, the South of Europe is the only real garden of utility to the perfumer. Grasse and Nice are the principal seats of the art; from their geographical position, the grower, within comparatively short distances, has at command that change of climate best fitted to bring to perfection the plants required for his trade. On the seacoast his Cassiæ grows without fear of frost, one night of which would destroy all the plants for a season; while, nearer the Alps, his violets are found sweeter than if grown in the warmer situations, where the orange tree and mignionette bloom to perfection. England can claim the superiority in the growth of lavender and peppermint; the essential oils extracted from these plants grown at Mitcham, in Surrey, realize eight times the price in the market of those produced in France or elsewhere, and are fully worth the difference for delicacy of odor. The odors of plants reside in different parts of them, sometimes in the roots, as in the iris and vitivert; the stem or wood, in cedar and sandal; the leaves, in mint, patchouly, and thyme; the flower, in the roses and violets; the seeds in the Tonquin bean and caraway; the bark, in cinnamon, &c. Some plants yield more than one odor, which are quite distinct and characteristic. The orange tree, for instance, gives three--from the leaves one called _petit grain_; from the flowers we procure _neroli_; and from the rind of the fruit, essential oil of orange, _essence of Portugal_. On this account, perhaps, this tree is the most valuable of all to the operative perfumer. The fragrance or odor of plants is owing, in nearly all cases, to a perfectly volatile oil, either contained in small vessels, or sacs within them, or generated from time to time, during their life, as when in blossom. Some few exude, by incision, odoriferous gums, as benzoin, olibanum, myrrh, &c.; others give, by the same act, what are called balsams, which appear to be mixtures of an odorous oil and an inodorous gum. Some of these balsams are procured in the country to which the plant is indigenous by boiling it in water for a time, straining, and then boiling again, or evaporating it down till it assumes the consistency of treacle. In this latter way is balsam of Peru procured from the _Myroxylon peruiferum_, and the balsam of Tolu from the _Myroxylon toluiferum_. Though their odors are agreeable, they are not much applied in perfumery for handkerchief use, but by some they are mixed with soap, and in England they are valued more for their medicinal properties than for their fragrance. SECTION II. "Were not summer's distillations left A liquid prisoner, pent in walls of glass, Beauty's effect with beauty were bereft, Nor it, nor no remembrance what it was; But flowers distilled, though they with winter meet, Leese but their show, their substance still lives sweet." SHAKSPEARE. The extensive flower farms in the neighborhood of Nice, Grasse, Montpellier, and Cannes, in France, at Adrianople (Turkey in Asia), at Broussa and Uslak (Turkey in Asia), and at Mitcham, in England, in a measure indicate the commercial importance of that branch of chemistry called perfumery. British India and Europe consume annually, at the very lowest estimate, 150,000 gallons of perfumed spirits, under various titles, such as eau de Cologne, essence of lavender, esprit de rose, &c. The art of perfumery does not, however, confine itself to the production of scents for the handkerchief and bath, but extends to imparting odor to inodorous bodies, such as soap, oil, starch, and grease, which are consumed at the toilette of fashion. Some idea of the commercial importance of this art may be formed, when we state that one of the large perfumers of Grasse and Paris employs annually 80,000 lbs. of orange flowers, 60,000 lbs. of cassia flowers, 54,000 lbs. of rose-leaves, 32,000 lbs. of jasmine blossoms, 32,000 lbs. of violets, 20,000 lbs. of tubereuse, 16,000 lbs. of lilac, besides rosemary, mint, lemon, citron, thyme, and other odorous plants in large proportion. In fact, the quantity of odoriferous substances used in this way is far beyond the conception of those even used to abstract statistics. To the chemical philosopher, the study of perfumery opens a book as yet unread; for the practical perfumer, on his laboratory shelves, exhibits many rare essential oils, such as essential oil of the flower of the _Acacia farnesiana_, essential oil of violets, tubereuse, jasmine, and others, the compositions of which have yet to be determined. The exquisite pleasure derived from smelling fragrant flowers would almost instinctively induce man to attempt to separate the odoriferous principle from them, so as to have the perfume when the season denies the flowers. Thus we find the alchemists of old, torturing the plants in every way their invention could devise for this end; and it is on their experiments that the whole art of perfumery has been reared. Without recapitulating those facts which may be found diffused through nearly all the old authors on medical botany, chemistry, pharmacy, and works of this character, from the time of Paracelsus to Celnart, we may state at once the mode of operation adopted by the practical perfumer of the present day for preparing the various extracts or essences, waters, oils, pomades, &c., used in his calling. The processes are divided into four distinct operations; viz.-- 1. _Expression_; 2. _Distillation_; 3. _Maceration_; 4. _Absorption_. 1. _Expression_ is only adopted where the plant is very prolific in its volatile or essential oil,--_i.e._ its odor; such, for instance, as is found in the pellicle or outer peel of the orange, lemon, and citron, and a few others. In these cases, the parts of the plant containing the odoriferous principle are put sometimes in a cloth bag, and at others by themselves into a press, and by mere mechanical force it is squeezed out. The press is an iron vessel of immense strength, varying in size from six inches in diameter, and twelve deep, and upwards, to contain one hundred weight or more; it has a small aperture at the bottom to allow the expressed material to run for collection; in the interior is placed a perforated false bottom, and on this the substance to be squeezed is placed, covered with an iron plate fitting the interior; this is connected with a powerful screw, which, being turned, forces the substance so closely together, that the little vessels containing the essential oils are burst, and it thus escapes. The common tincture press is indeed a model of such an instrument. The oils which are thus collected are contaminated with watery extracts, which exudes at the same time, and from which it has to be separated; this it does by itself in a measure, by standing in a quiet place, and it is then poured off and strained. [Illustration: Pipette to draw off small portions of otto from water.] 2. _Distillation._--The plant, or part of it, which contains the odoriferous principle, is placed in an iron, copper, or glass pan, varying in size from that capable of holding from one to twenty gallons, and covered with water; to the pan a dome-shaped lid is fitted, terminating with a pipe, which is twisted corkscrew fashion, and fixed in a bucket, with the end peeping out like a tap in a barrel. The water in the still--for such is the name of the apparatus--is made to boil; and having no other exit, the steam must pass through the coiled pipe; which, being surrounded with cold water in the bucket, condenses the vapor before it can arrive at the tap. With the steam, the volatile oils--_i.e._ perfume--rises, and is liquefied at the same time. The liquids which thus run over, on standing for a time, separate into two portions, and are finally divided with a funnel having a stopcock in the narrow part of it. By this process, the majority of the volatile or essential oils are procured. In some few instances alcohol--_i.e._ rectified spirit of wine--is placed upon the odorous materials in lieu of water, which, on being distilled, comes away with the perfuming substance dissolved in it. But this process is now nearly obsolete, as it is found more beneficial to draw the oil or essence first with water, and afterwards to dissolve it in the spirit. The low temperature at which spirit boils, compared with water, causes a great loss of essential oil, the heat not being sufficient to disengage it from the plant, especially where seeds such as cloves or caraway are employed. It so happens, however, that the finest odors, the _recherché_ as the Parisians say, cannot be procured by this method; then recourse is had to the next process. [Illustration: Tap funnel for separating ottos from water and spirits from oil.] 3. _Maceration._--Of all the processes for procuring the perfumes of flowers, this is the most important to the perfumer, and is the least understood in England; as this operation yields not only the most exquisite essences indirectly, but also nearly all those fine pomades known here as "French pomatums," so much admired for the strength of fragrance, together with "French oils" equally perfumed. The operation is conducted thus:--For what is called pomade, a certain quantity of purified mutton or deer suet is put into a clean metal or porcelain pan, this being melted by a steam heat; the kind of flowers required for the odor wanted are carefully picked and put into the liquid fat, and allowed to remain from twelve to forty-eight hours; the fat has a particular affinity or attraction for the oil of flowers, and thus, as it were, draws it out of them, and becomes itself, by their aid, highly perfumed; the fat is strained from the spent flowers, and fresh are added four or five times over, till the pomade is of the required strength; these various strengths of pomatums are noted by the French makers as Nos. 6, 12, 18, and 24, the higher numerals indicating the amount of fragrance in them. For perfumed oils the same operation is followed; but, in lieu of suet, fine olive oil or oil of ben, derived from the ben nuts of the Levant, is used, and the same results are obtained. These oils are called "Huile Antique" of such and such a flower. When neither of the foregoing processes gives satisfactory results, the method of procedure adopted is by,-- 4. _Absorption_, or _Enfleurage._--The odors of some flowers are so delicate and volatile, that the heat required in the previously named processes would greatly modify, if not entirely spoil them; this process is, therefore, conducted cold, thus:--Square frames, about three inches deep, with a glass bottom, say two feet wide and three feet long, are procured; over the glass a layer of fat is spread, about half an inch thick, with a kind of plaster knife or spatula; into this the flower buds are stuck, cup downwards, and ranged completely over it, and there left from twelve to seventy-two hours. Some houses, such as that of Messrs. Pilar and Sons; Pascal Brothers; H. Herman, and a few others, have 3000 such frames at work during the season; as they are filled, they are piled one over the other, the flowers are changed so long as the plants continue to bloom, which now and then exceeds two or three months. For oils of the same plants, coarse linen cloths are imbued with the finest olive oil or oil of ben, and stretched upon a frame made of iron; on these the flowers are laid and suffered to remain a few days. This operation is repeated several times, after which the cloths are subjected to great pressure, to remove the now perfumed oil. As we cannot give any general rule for working, without misleading the reader, we prefer explaining the process required for each when we come to speak of the individual flower or plant. SECTION III. Whenever a Still is named, or an article is said to be distilled or "drawn," it must be understood to be done so by steam apparatus, as this is the only mode which can be adopted for obtaining anything like a delicate odor; the old plan of having the fire immediately under the still, conveying an empyreumatic or burnt smell to the result, has become obsolete in every well-regulated perfumatory. The steam-still differs from the one described only in the lower part, or pan, which is made double, so as to allow steam from a boiler to circulate round the pan for the purpose of boiling the contents, instead of the direct fire. In macerating, the heat is applied in the same way, or by a contrivance like the common glue-pot, as made use of nowadays. This description of apparatus will be found very useful for experiments which we will suggest by-and-by. The perfumes for the handkerchief, as found in the shops of Paris and London, are either simple or compound; the former are called extracts, _extraits_, _esprits_, or essences, and the latter _bouquets_ and nosegays, which are mixtures of the extracts so compounded in quantity that no one flower or odor can be discovered as predominating over another; and when made of the delicate-scented flowers carefully blended, they produce an exquisite sensation on the olfactory nerve, and are therefore much prized by all who can afford to purchase them. We shall first explain the mode for obtaining the simple extracts of flowers. This will be followed by the process for preparing ambergris, musk, and civet, substances, which, though of animal origin, are of the utmost importance as forming a large part in the most approved bouquets; and we shall conclude this department of the art with recipes for all the fashionable bouquets and nosegays, the value of which, we doubt not, will be estimated according to the labor bestowed upon their analysis. In order to render the work more easy of consultation, we have adopted the alphabetical arrangement in preference to a more scientific classification. Among the collection of ottos of the East India Company at the Exhibition of 1851, were several hitherto unknown in this country, and possessing much interest. It is to be regretted, that no person having any practical knowledge of perfumery was placed on the jury of Class IV or XXIX. Had such been the case, the desires of the exhibitors would probably have been realized, and European perfumers benefited by the introduction of new odors from the East. Some of the ottos sent by a native perfumer of Benares were deemed worthy of honorable mention. Such as _Chumeylee_, _Beyla_, _Begla_, _Moteya_, and many others from the Moluccas, but without any information respecting them. We are not going to speak of, perhaps, more than a tithe of the plants that have a perfume--only those will be mentioned that are used by the operative perfumer, and such as are imitated by him in consequence of there being a demand for the article, which circumstances prevent him from obtaining in its genuine state. The first that comes under our notice is-- ALLSPICE.--The odoriferous principle of allspice, commonly called pimento, is obtained by distilling the dried fruit, before it is quite ripe, of the _Eugenia pimenta_ and _Myrtus pimenta_ with water. It is thus procured as an essential oil; it is but little used in perfumery, and when so, only in combination with other spice oils; for scenting soap it is, however, very agreeable, and much resembles the smell of cloves, and deserves more attention than it has hitherto received. Mixed in the proportion of two ounces of oil of allspice with one gallon of rectified spirit of wine, it forms what may be termed extract of allspice, which extract will be found very useful in the manufacture of low-priced bouquets. ALMONDS. "Mark well the flow'ring almonds in the wood; If od'rous blooms the bearing branches load, The glebe will answer to the sylvan reign, Great heats will follow, and large crops of grain." VIRGIL. This perfume has been much esteemed for many ages. It may be procured by distilling the leaves of any of the laurel tribe, and the kernels of stone fruit; for trade purposes, it is obtained from the bitter almonds, and exists in the skin or pellicle that covers the seed after it is shelled. In the ordinary way, the almonds are put into the press for the purpose of obtaining the mild or fat oil from the nut; the cake which is left after this process is then mixed with salt and water, and allowed to remain together for about twenty-four hours prior to distillation. The reason for moistening the cake is well understood to the practical chemist, and although we are not treating the subject of perfumery in a chemical sense, but only in a practical way, it may not be inappropriate here to observe, that the essential oil of almonds does not exist ready formed to any extent in the nut, but that it is produced by a species of fermentation, from the amygdalin and emulsine contained in the almonds, together with the water that is added. Analogous substances exist in laurel leaves, and hence the same course is to be pursued when they are distilled. Some manufacturers put the moistened cake into a bag of coarse cloth, or spread it upon a sieve, and then force the stream through it; in either case, the essential oil of the almond rises with the watery vapor, and is condensed in the still-worm. In this concentrated form, the odor of almonds is far from agreeable; but when diluted with spirit, in the proportion of about one and a half ounce of the oil to a gallon of spirit or alcohol, it is very pleasant. [Illustration: Almond.] The essential oil of almonds, enters into combination with soap, cold cream, and many other materials prepared by the perfumer; for which see their respective titles. Fourteen pounds of the cake yield about one ounce of essential oil. In experiments with this substance, it must be carefully remembered that it is exceedingly _poisonous_, and, therefore, great caution is necessary in its admixture with substances used as a cosmetic, otherwise dangerous results may ensue. _Artificial Otto of Almonds._--Five or six years ago, Mr. Mansfield, of Weybridge, took out a patent for the manufacture of otto of almonds from benzole. (Benzole is obtained from tar oil.) His apparatus, according to the Report of the juries of the 1851 Exhibition, consists of a large glass tube in the form of a coil, which at the upper end divides into two tubes; each of which is provided with a funnel. A stream of nitric acid flows slowly into one of the funnels, and benzole into the other. The two substances meet at the point of union of the tubes, and a combination ensues with the evolution of heat. As the newly formed compound flows down through the coil it becomes cool, and is collected at the lower extremity; it then requires to be washed with water, and lastly with a dilute solution of carbonate of soda, to render it fit for use. Nitro-benzole, which is the chemical name for this artificial otto of almonds, has a different odor to the true otto of almonds, but it can nevertheless be used for perfuming soap. Mr. Mansfield writes to me under date of January 3d, 1855:--"In 1851, Messrs. Gosnell, of Three King Court, began to make this perfume under my license; latterly I withdrew the license from them by their consent, and since then it is not made that I am aware of." It is, however, quite common in Paris. ANISE.--The odorous principle is procured by distilling the seeds of the plant _Pimpinella anisum_; the product is the oil of aniseed of commerce. As it congeals at a temperature of about 50° Fahr., it is frequently adulterated with a little spermaceti, to give a certain solidity to it, whereby other cheaper essential oils can be added to it with less chance of detection. As the oil of aniseed is quite soluble in spirit, and the spermaceti insoluble, the fraud is easily detected. This perfume is exceedingly strong, and is, therefore, well adapted for mixing with soap and for scenting pomatums, but does not do nicely in compounds for handkerchief use. BALM, oil of Balm, called also oil of Melissa, is obtained by distilling the leaves of the _Melissa officinalis_ with water; it comes from the still tap with the condensed steam or water, from which it is separated with the tap funnel. But it is very little used in perfumery, if we except its combination in _Aqua di Argento_. BALSAM.--Under this title there are two or three substances used in perfumery, such as balsam of Peru, balsam of Tolu, and balsam of storax (also called liquid amber). The first-named, is procured from the _Myroxylon peruiferum_; it exudes from the tree when wounded, and is also obtained by boiling down the bark and branches in water. The latter is the most common method for procuring it. It has a strong odor, like benzoin. Balsam of Tolu flows from the _Toluifera balsammum_. It resembles common resin (rosin); with the least warmth, however, it runs to a liquid, like brown treacle. The smell of it is particularly agreeable, and being soluble in alcohol makes a good basis for a bouquet, giving in this respect a permanence of odor to a perfume which the simple solution of an oil would not possess. For this purpose all these balsams are very useful, though not so much used as they might be. "ULEX has found that balsam of Tolu is frequently adulterated with common resin. To detect this adulteration he pours sulphuric acid on the balsam, and heats the mixture, when the balsam dissolves to a cherry-red fluid, without evolving sulphurous acid, but with the escape of benzoic or cinnamic acid, if no common resin is present. On the contrary, the balsam foams, blackens, and much sulphurous acid is set free, if it is adulterated with common resin."--_Archives der Pharmacie_. Balsam of storax, commonly called gum styrax, is obtained in the same manner, and possessing similar properties, with a slight variation of odor, is applicable in the same manner as the above. They are all imported from South America, Chili, and Mexico, where the trees that produce them are indigenous. BAY, oil of sweet Bay, also termed essential oil of laurel-berries, is a very fragrant substance, procured by distillation from the berries of the bay laurel. Though very pleasant, it is not much used. BERGAMOT.--This most useful perfume is procured from the _Citrus Bergamia_, by expression from the peel of the fruit. It has a soft sweet odor, too well known to need description here. When new and good it has a greenish-yellow tint, but loses its greenness by age, especially if kept in imperfectly corked bottles. It then becomes cloudy from the deposit of resinous matter, produced by the contact of the air, and acquires a turpentine smell. It is best preserved in well-stoppered bottles, kept in a cool cellar, and in the dark; light, especially the direct sunshine, quickly deteriorates its odor. This observation may be applied, indeed, to all perfumes, except rose, which is not so spoiled. When bergamot is mixed with other essential oils it greatly adds to their richness, and gives a sweetness to spice oils attainable by no other means, and such compounds are much used in the most highly scented soaps. Mixed with rectified spirit in the proportions of about four ounces of bergamot to a gallon, it forms what is called "extract of bergamot," and in this state is used for the handkerchief. Though well covered with extract of orris and other matters, it is the leading ingredient in Bayley and Blew's Ess. Bouquet (see BOUQUETS). [Illustration: Styrax Benzoin.] BENZOIN, also called Benjamin.--This is a very useful substance to perfumers. It exudes from the _Styrax benzoin_ by wounding the tree, and drying, becomes a hard gum-resin. It is principally imported from Borneo, Java, Sumatra, and Siam. The best kind comes from the latter place, and used to be called Amygdaloides, because of its being interspersed with several white spots, which resemble broken almonds. When heated, these white specks rise as a smoke, which is easily condensed upon paper. The material thus separated from the benzoin is called flowers of benzoin in commerce, and by chemists is termed benzoic acid. It has all, or nearly all, the odor of the resin from which it is derived. The extract, or tincture of benzoin, forms a good basis for a bouquet.[B] Like balsam of Tolu, it gives permanence and body to a perfume made with an essential oil in spirit. The principal consumption of benzoin is in the manufacture of pastilles (see PASTILLES), and for the preparation of fictitious vanilla pomade (see POMATUMS). CARAWAY.--This odoriferous principle is drawn by distillation from the seeds of the _Carum carui_. It has a very pleasant smell, quite familiar enough without description. It is well adapted to perfume soap, for which it is much used in England, though rarely if ever on the continent; when dissolved in spirit it may be used in combination with oil of lavender and bergamot for the manufacture of cheap essences, in a similar way to cloves (see CLOVES). If caraway seeds are ground, they are well adapted for mixing to form sachet powder (see SACHETS). CASCARILLA.--The bark is used in the formation of pastilles, and also enters into the composition known as _Eau à Bruler_, for perfuming apartments, to which we refer. The bark alone of this plant is used by the manufacturing perfumer, and that only in the fabrication of pastilles. The _Cascarilla gratissimus_ is however so fragrant, that according to Burnett its leaves are gathered by the Koras of the Cape of Good Hope as a perfume, and both the _C. fragrans_ and _C. fragilis_ are odoriferous. It behooves perfumers, therefore, who are on the look out for novelties, to obtain these leaves and ascertain the result of their distillation. Messrs. Herring and Co., some years ago, drew the oil of cascarilla, but it was only offered to the trade as a curiosity. CASSIA.--The essential oil of cassia is procured by distilling the outer bark of the _Cinnamomum cassia_. 1 cwt. of bark yields rather more than three quarters of a pound of oil; it has a pale yellow color; in smell it much resembles cinnamon, although very inferior to it. It is principally used for perfuming soap, especially what is called "military soap," as it is more aromatic or spicy than flowery in odor; it therefore finds no place for handkerchief use. CASSIE.-- "The short narcissus and fair daffodil, Pansies to please the sight, and _cassie_ sweet to swell." DRYDEN'S _Virgil_. This is one of those fine odors which enters into the composition of the best handkerchief bouquets. [Illustration: Flower-buds of the Acacia Farnesiana.] When smelled at alone, it has an intense violet odor, and is rather sickly sweet. It is procured by maceration from the _Acacia farnesiana_. The purified fat is melted, into which the flowers are thrown and left to digest for several hours; the spent flowers are removed, and fresh are added, eight or ten times, until sufficient richness of perfume is obtained. As many flowers are used as the grease will cover, when they are put into it, in a liquid state. After being strained, and the pomade has been kept at a heat sufficient only to retain its liquidity, all impurities will subside by standing for a few days. Finally cooled, it is the cassie pomade of commerce. The _Huile de Cassie_, or fat oil of cassie, is prepared in a similar manner, substituting the oil of Egyptian ben nut, olive oil, or almond oil, in place of suet. Both these preparations are obviously only a solution of the true essential oil of cassie flowers in the neutral fatty body. Europe may shortly be expecting to import a similar scented pomade from South Australia, derived from the Wattle, a plant that belongs to the same genus as the _A. farnesiana_, and which grows most luxuriantly in Australia. Mutton fat being cheap, and the wattle plentiful, a profitable trade may be anticipated in curing the flowers, &c. To prepare the extract of cassie, take six pounds of No. 24 (best quality) cassie pomade, and place upon it one gallon of the best rectified spirit, as sent out by Bowerbank, of Bishopsgate. After it has digested for three weeks or a month, at a summer heat, it is fit to draw from the pomatum, and, if good, has a beautiful green color and rich flowery smell of the cassie blossom. All extracts made by this process--_maceration_, or, as it may be called, cold _infusion_, give a more natural smell of the flowers to the result, than by merely dissolving the essential oil (procured by distillation) in the spirit; moreover, where the odor of the flower exists in only very minute quantities, as in the present instance, and with violet, jasmine, &c., it is the only practical mode of proceeding. In this, and all other similar cases, the pomatum must be cut up into very small pieces, after the domestic manner of "chopping suet," prior to its being infused in the alcohol. The action of the mixture is simply a change of place in the odoriferous matter, which leaves the fat body by the superior attraction, or affinity, as the chemists say, of the spirits of wine, in which it freely dissolves. The major part of the extract can be poured or drawn off the pomatum without trouble, but it still retains a portion in the interstices, which requires time to drain away, and this must be assisted by placing the pomatum in a large funnel, supported by a bottle, in order to collect the remainder. Finally, all the pomatum, which is now called _washed pomatum_, is to be put into a tin, which tin must be set into hot water, for the purpose of melting its contents; when the pomatum thus becomes liquefied, any extract that is still in it rises to the surface, and can be skimmed off, or when the pomatum becomes cold it can be poured from it. The washed pomatum is preserved for use in the manufacture of dressing for the hair, for which purpose it is exceedingly well adapted, on account of the purity of the grease from which it was originally prepared, but more particularly on account of a certain portion of odor which it still retains; and were it not used up in this way, it would be advisable to put it for a second infusion in spirit, and thus a weaker extract could be made serviceable for lower priced articles. I cannot leave cassie without recommending it more especially to the notice of perfumers and druggists, as an article well adapted for the purpose of the manufacture of essences for the handkerchief and pomades for the hair. When diluted with other odors, it imparts to the whole such a true flowery fragrance, that it is the admiration of all who smell it, and has not a little contributed to the great sale which certain proprietary articles have attained. We caution the inexperienced not to confound cassie with cassia, which has a totally different odor. See ACACIA POMADE. CEDAR WOOD now and then finds a place in a perfumer's warehouse; when ground, it does well to form a body for sachet powder. Slips of cedar wood are sold as matches for lighting lamps, because while burning an agreeable odor is evolved; some people use it also, in this condition, distributed among clothes in drawers to "prevent moth." On distillation it yields an essential oil that is exceedingly fragrant. Messrs. Rigge and Co., of London, use it extensively for scenting soap. LEBANON CEDAR WOOD. (_For the Handkerchief._) Otto of cedar, 1 oz. Rectified spirit, 1 pint. Esprit rose trip, 1/4 pint. The tincture smells agreeably of the wood, from which it can readily be made. Its crimson color, however, prohibits it from being used for the handkerchief. It forms an excellent tincture for the teeth, and is the basis of the celebrated French dentifrice "eau Botot." CEDRAT.--This perfume is procured from the rind of the citron fruit (_Citrus medica_), both by distillation and expression; it has a very beautiful lemony odor, and is much admired. It is principally used in the manufacture of essences for the handkerchief, being too expensive for perfuming grease or soap. What is called extract of cedrat is made by dissolving two ounces of the above essential oil of citron in one pint of spirits, to which some perfumers add half an ounce of bergamot. CINNAMON.--Several species of the plant _Laurus cinnamomum_ yield the cinnamon and cassia of commerce. Its name is said to be derived from _China Amomum_, the bark being one of the most valued spices of the East. Perfumers use both the bark and the oil, which is obtained by distillation from it. The ground bark enters into the composition of some pastilles, tooth powders, and sachets. The essential oil of cinnamon is principally brought to this country from Ceylon; it is exceedingly powerful, and must be used sparingly. In such compounds as cloves answer, so will cinnamon. CITRON.--On distilling the flowers of the _Citrus medica_, a very fragrant oil is procured, which is a species of neroli, and is principally consumed by the manufacturers of eau de Cologne. CITRONELLA.--Under this name there is an oil in the market, chiefly derived from Ceylon and the East Indies; its true origin we are unable to decide; in odor it somewhat resembles citron fruit, but is very inferior. Probably it is procured from one of the grasses of the _Andropogon_ genus. Being cheap, it is extensively used for perfuming soap. What is now extensively sold as "honey" soap, is a fine yellow soap slightly perfumed with this oil. Some few use it for scenting grease, but it is not much admired in that way. CLOVES.--Every part of the clove plant (_Caryophyllus aromaticus_) abounds with aromatic oil, but it is most fragrant and plentiful in the unexpanded flower-bud, which are the cloves of commerce. Cloves have been brought into the European market for more than 2000 years. The plant is a native of the Moluccas and other islands in the China seas. "The average annual crop of cloves," says Burnett, "is, from each tree, 2 or 2-1/2 lbs., but a fine tree has been known to yield 125 lbs. of this spice in a single season, and as 5000 cloves only weigh one pound, there must have been at least 625,000 flowers upon this single tree." [Illustration: Clove.] The oil of cloves may be obtained by expression from the fresh flower-buds, but the usual method of procuring it is by distillation, which is carried on to a very great extent in this country. Few essential oils have a more extensive use in perfumery than that of cloves; it combines well with grease, soap, and spirit, and, as will be seen in the recipes for the various bouquets given hereafter, it forms a leading feature in some of the most popular handkerchief essences, Rondeletia, the Guard's Bouquet, &c., and will be found where least expected. For essence of cloves, dissolve oil of cloves in the proportion of two ounces of oil to one gallon of spirit. DILL.--Perfumers are now and then asked for "dill water;" it is, however, more a druggist's article than a perfumer's, as it is more used for its medicinal qualities than for its odor, which by the way, is rather pleasant than otherwise. Some ladies use a mixture of half dill water and half rose water, as a simple cosmetic, "to clear the complexion." The oil of dill is procured by submitting the crushed fruit of dill (_Anethum graveolens_) with water to distillation. The oil floats on the surface of the distillate, from which it is separated by the funnel in the usual manner; after the separation of the oil, the "water" is fit for sale. Oil of dill may be used with advantage, if in small proportions, and mixed with other oils, for perfuming soap. EGLANTINE, or SWEET BRIAR, notwithstanding what the poet Robert Noyes says-- "In fragrance yields, Surpassing citron groves or spicy fields," does not find a place in the perfumer's "scent-room" except in name. This, like many other sweet-scented plants, does not repay the labor of collecting its odor. The fragrant part of this plant is destroyed more or less under every treatment that it is put to, and hence it is discarded. As, however, the article is in demand by the public, a species of fraud is practised upon them, by imitating it thus:-- IMITATION EGLANTINE, OR ESSENCE OF SWEET BRIAR. Spirituous extract of French rose pomatum, 1 pint. " " cassie, 1/4 " " " fleur d'orange, 1/4 " Esprit de rose, 1/4 " Oil of neroli, 1/2 drachm. Oil of lemon grass (verbena oil), 1/2 " ELDER (_Sambucus nigra_).--The only preparation of this plant for its odorous quality used by the perfumer, is elder-flower water. To prepare it, take nine pounds of elder-flowers, free from stalk, and introduce it to the still with four gallons of water; the first three gallons that come over is all that need be preserved for use; one ounce of rectified spirit should be added to each gallon of "water" distilled, and when bottled it is ready for sale. Other preparations of elder flowers are made, such as milk of elder, extract of elder, &c., which will be found in their proper place under Cosmetics. Two or three new materials made from this flower will also be given hereafter, which are likely to meet with a very large sale on account of the reputed cooling qualities of the ingredients; of these we would call attention more particularly to cold cream of elder-flowers, and to elder oil for the hair. The preparations of elder-flowers, if made according to the Pharmacopoeias, are perfectly useless, as the forms therein given show an utter want of knowledge of the properties of the materials employed. FENNEL (_Foeniculum vulgare_).--Dried fennel herb, when ground, enters into the composition of some sachet powders. The oil of fennel, in conjunction with other aromatic oils, may be used for perfuming soap. It is procurable by distillation. FLAG (SWEET) (_Acorus calamus_).--The roots, or rhizome, of the sweet flag, yield by distillation a pleasant-smelling oil; 1 cwt. of the rhizome will thus yield one pound of oil. It can be used according to the pleasure of the manufacturer in scenting grease, soap, or for extracts, but requires other sweet oils with it to hide its origin. GERANIUM (_Pelargonium odoratissimum_, rose-leaf geranium).--The leaves of this plant yield by distillation a very agreeable rosy-smelling oil, so much resembling real otto of rose, that it is used very extensively for the adulteration of that valuable oil, and is grown very largely for that express purpose. It is principally cultivated in the south of France, and in Turkey (by the rose-growers). In the department of Seine-et-Oise, at Montfort-Lamaury, in France, hundreds of acres of it may be seen growing. 1 cwt. of leaves will yield about two ounces of essential oil. Used to adulterate otto of rose, it is in its turn itself adulterated with ginger grass oil (_Andropogon_), and thus formerly was very difficult to procure genuine; on account of the increased cultivation of the plant, it is now, however, easily procured pure. Some samples are greenish-colored, others nearly white, but we prefer that of a brownish tint. When dissolved in rectified spirit, in the proportion of about six ounces to the gallon, it forms the "extract of rose-leaf geranium" of the shops. A word or two is necessary about the oil of geranium, as much confusion is created respecting it, in consequence of there being an oil under the name of geranium, but which in reality is derived from the _Andropogon nardus_, cultivated in the Moluccas. This said andropogon (geranium!) oil can be used to adulterate the true geranium, and hence we suppose its nomenclature in the drug markets. The genuine rose-leaf geranium oil fetches about 6_s._ per ounce, while the andropogon oil is not worth more than that sum per pound. And we may observe here, that the perfuming essential oils are best purchased through the wholesale perfumers, as from the nature of their trade they have a better knowledge and means of obtaining the real article than the drug-broker. On account of the pleasing odor of the true oil of rose-leaf geranium, it is a valuable article for perfuming many materials, and appears to give the public great satisfaction. HELIOTROPE.--Either by maceration or enfleurage with clarified fat, we may obtain this fine odor from the flowers of the _Heliotrope Peruvianum_ or _H. grandiflorum_. Exquisite as the odor of this plant is, at present it is not applied to use by the manufacturing perfumer. This we think rather a singular fact, especially as the perfume is powerful and the flowers abundant. We should like to hear of some experiments being tried with this plant for procuring its odor in this country, and for that purpose now suggest the mode of operation which would most likely lead to successful results. For a small trial in the first instance, which can be managed by any person having the run of a garden, we will say, procure an ordinary glue-pot now in common use, which melts the material by the boiling of water; it is in fact a water-bath, in chemical parlance--one capable of holding a pound or more of melted fat. At the season when the flowers are in bloom, obtain half a pound of fine mutton suet, melt the suet and strain it through a close hair-sieve, allow the liquefied fat, as it falls from the sieve, to drop into cold spring water; this operation granulates and washes the blood and membrane from it. In order to start with a perfectly inodorous grease, the melting and granulation process may be repeated three or four times; finally, remelt the fat and cast it into a pan to free it from adhering water. Now put the clarified suet into the macerating pot, and place it in such a position near the fire of the greenhouse, or elsewhere that will keep it warm enough to be liquid; into the fat throw as many flowers as you can, and there let them remain for twenty-four hours; at this time strain the fat from the spent flowers and add fresh ones; repeat this operation for a week: we expect at the last straining the fat will have become very highly perfumed, and when cold may be justly termed _Pomade à la Heliotrope_. The cold pomade being chopped up, like suet for a pudding, is now to be put into a wide-mouthed bottle, and covered with spirits as highly rectified as can be obtained, and left to digest for a week or more; the spirit then strained off will be highly perfumed; in reality it will be _extract of Heliotrope_, a delightful perfume for the handkerchief. The rationale of the operation is simple enough: the fat body has a strong affinity or attraction for the odorous body, or essential oil of the flowers, and it therefore absorbs it by contact, and becomes itself perfumed. In the second operation, the spirit has a much greater attraction for the fragrant principle than the fatty matter; the former, therefore, becomes perfumed at the expense of the latter. The same experiment may be repeated with almond oil substituted for the fat. The experiment here hinted at, may be varied with any flowers that there are to spare; indeed, by having the macerating bath larger than was mentioned above, an excellent _millefleur_ pomade and essence might be produced from every conservatory in the kingdom, and thus we may receive another enjoyment from the cultivation of flowers beyond their beauty of form and color. We hope that those of our readers who feel inclined to try experiments of this nature will not be deterred by saying, "they are not worth the trouble." It must be remembered, that very fine essences realize in the London perfumery warehouses 16_s._ per pint of 16 ounces, and that fine _flowery-scented_ pomades fetch the same sum per pound. If the experiments are successful they should be published, as then we may hope to establish a new and important manufacture in this country. But we are digressing. The odor of heliotrope resembles a mixture of almonds and vanilla, and is well imitated thus:-- EXTRACT OF HELIOTROPE. Spirituous extract of vanilla, 1/2 pint. " " French rose pomatum, 1/4 " " " orange-flower pomatum, 2 oz. " " ambergris, 1 oz. Essential oil of almonds, 5 drops. A preparation made in this manner under the name of _Extract de Heliotrope_ is that which is sold in the shops of Paris and London, and is really a very nice perfume, passing well with the public for a genuine extract of heliotrope. HONEYSUCKLE or WOODBINE:-- "Copious of flower the woodbine, pale and wan, But well compensating her sickly looks With never-cloying odors." What the poet Cowper here says is quite true; nevertheless, it is a flower that is not used in practical perfumery, though there is no reason for abandoning it. The experiments suggested for obtaining the odor of Heliotrope and Millefleur (thousand flowers) are also applicable to this, as also to Hawthorn. A good IMITATION OF HONEYSUCKLE is made thus:-- Spirituous extract of rose pomatum, 1 pint. " " violet " 1 " " " tubereuse " 1 " Extract of vanilla, 1/4 " " Tolu, 1/4 " Otto neroli, 10 drops. " almonds, 5 " The prime cost of a perfume made in this manner would probably be too high to meet the demand of a retail druggist; in such cases it may be diluted with rectified spirit to the extent "to make it pay," and will yet be a nice perfume. The formula generally given herein for odors is in anticipation that when bottled they will retail for at least eighteen-pence the fluid ounce! which is the average price put on the finest perfumery by the manufacturers of London and Paris. HOVENIA.--A perfume under this name is sold to a limited extent, but if it did not smell better than the plant _Hovenia dulcis_ or _H. inequalis_, a native of Japan, it would not sell at all. The article in the market is made thus:-- Rectified spirit, 1 quart. Rose-water, 1/2 pint. Otto lemons, 1/2 oz. Otto of rose, 1 drachm. " cloves, 1/2 " " neroli, 10 drops. First dissolve the ottos in the spirit, then add the rose-water. After filtration it is ready for sale. When compounds of this kind do not become bright by passing through blotting-paper, the addition of a little carbonate of magnesia prior to filtering effectually clears them. The water in the above recipe is only added in order that the article produced may be retailed at a moderate price, and would, of course, be better without that "universal friend." JASMINE.-- "Luxuriant above all, The jasmine throwing wide her elegant sweets." This flower is one of the most prized by the perfumer. Its odor is delicate and sweet, and so peculiar that it is without comparison, and as such cannot be imitated. When the flowers of the _Jasminum odoratissimum_ are distilled, repeatedly using the water of distillation over fresh flowers, the essential oil of jasmine may be procured. It is, however, exceedingly rare, on account of the enormous cost of production. There was a fine sample of six ounces exhibited in the Tunisian department of the Crystal Palace, the price of which was 9_l._ the fluid ounce! The plant is the Yasmyn of the Arabs, from which our name is derived. In the perfumer's laboratory, the method of obtaining the odor is by absorption, or, as the French term it, _enfleurage_; that is, by spreading a mixture of pure lard and suet on a glass tray, and sticking the fresh-gathered flowers all over it, leaving them to stand a day or so, and repeating the operation with fresh flowers--the grease absorbs the odor. Finally, the pomade is scraped off the glass or slate, melted at as low a temperature as possible, and strained. Oils strongly impregnated with the fragrance are also prepared much in the same way. Layers of cotton wool, previously steeped in oil of ben (obtained by pressure from the blanched nuts of the _Moringa oleifera_) are covered with jasmine flowers, which is repeated several times; finally, the cotton or linen cloths which some perfumers use, are squeezed under a press. The jasmine oil thus produced is the _Huile antique au jasmin_ of the French houses. The "extract of jasmine" is prepared by pouring rectified spirit on the jasmine pomade or oil, and allowing them to remain together for a fortnight at a summer heat. The best quality extract requires two pounds of pomatum to every quart of spirit. The same can be done with the oil of jasmine. If the pomade is used, it must be cut up fine previously to being put into the spirit; if the oil is used, it must be shaken well together every two or more hours, otherwise, on account of its specific gravity, the oil separates, and but little surface is exposed to the spirit. After the extract is strained off, the "washed" pomatum or oil is still useful, if remelted, in the composition of pomatum for the hair, and gives more satisfaction to a customer than any of the "creams and balms," &c. &c., made up and scented with essential oils; the one smells of the flower, the other "a nondescript." [Illustration: Jasmine.] The extract of jasmine enters into the composition of a great many of the most approved handkerchief perfumes sold by the English and French perfumers. Extract of jasmine is sold for the handkerchief often pure, but is one of those scents which, though very gratifying at first, becomes what people call "sickly" after exposure to the oxidizing influence of the air, but if judiciously mixed with other perfumes of an opposite character is sure to please the most fastidious customer. JONQUIL.--The scent of the jonquil is very beautiful; for perfumery purposes it is however but little cultivated in comparison with jasmine and tubereuse. It is prepared exactly as jasmine. The Parisian perfumers sell a mixture which they call "extract of jonquil." The plant, however, only plays the part of a godfather to the offspring, giving it its name. The so-called jonquil is made thus:-- Spirituous extract of jasmine pomade, 1 pint. " " tubereuse " 1 " " " fleur d'orange, 1/2 " Extract of vanilla, 2 fluid ounces. LAUREL.--By distillation from the berries of the _Laurus nobilis_, and from the leaves of the _Laurus cerasus_, an oil and perfumed water are procurable of a very beautiful and fragrant character. Commercially, however, it is disregarded, as from the similarity of odor to the oil distilled from the bitter almond, it is rarely, if ever, used by the perfumer, the latter being more economical. LAVENDER.--The climate of England appears to be better adapted for the perfect development of this fine old favorite perfume than any other on the globe. "The ancients," says Burnett, "employed the flowers and the leaves to aromatize their baths, and to give a sweet scent to water in which they washed; hence the generic name of the plant, _Lavandula_." Lavender is grown to an enormous extent at Mitcham, in Surrey, which is the seat of its production, in a commercial point of view. Very large quantities are also grown in France, but the fine odor of the British produce realizes in the market four times the price of that of Continental growth. Burnett says that the oil of _Lavandula spica_ is more pleasant than that derived from the other species, but this statement must not mislead the purchaser to buy the French spike lavender, as it is not worth a tenth of that derived from the _Lavandulæ veræ_. Half-a-hundred weight of good lavender flowers yield, by distillation, from 14 to 16 oz. of essential oil. All the inferior descriptions of oil of lavender are used for perfuming soaps and greases; but the best, that obtained from the Mitcham lavender, is entirely used in the manufacture of what is called lavender water, but which, more properly, should be called essence or extract of lavender, to be in keeping with the nomenclature of other essences prepared with spirit. The number of formulæ published for making a liquid perfume of lavender is almost endless, but the whole of them may be resolved into essence of lavender, simple; essence of lavender, compound; and lavender water. There are two methods of making essence of lavender:--1. By distilling a mixture of essential oil of lavender and rectified spirit; and the other--2. By merely mixing the oil and the spirit together. The first process yields the finest quality: it is that which is adopted by the firm of Smyth and Nephew, whose reputation for this article is such that it gives a good character in foreign markets, especially India, to all products of lavender of English manufacture. Lavender essence, that which is made by the still, is quite white, while that by mixture only always has a yellowish tint, which by age becomes darker and resinous. SMYTH'S LAVENDER. To produce a very fine distillate, take-- Otto of English Lavender, 4 oz. Rectified spirit (60 over proof), 5 pints. Rose-water, 1 pint. Mix and distil five pints for sale. Such essence of lavender is expensive, but at 10_s._ a pint of 14 oz! there _is_ a margin for profit. It not being convenient to the general dealer to sell distilled lavender essence, the following form, by mixture, will produce a first-rate article, and nearly as white as the above. ESSENCE OF LAVENDER. Otto of lavender, 3-1/2 oz. Rectified spirit, 2 quarts. The perfumer's retail price for such quality is 8_s._ per pint of 14 oz. Many perfumers and druggists in making lavender water or essence, use a small portion of bergamot, with an idea of improving its quality--a very erroneous opinion; moreover, such lavender quickly discolors. LAVENDER WATER.--Take: English oil of lavender, 4 oz. Spirit, 3 quarts. Rose-water, 1 pint. Filter as above, and it is ready for sale. COMMON LAVENDER WATER.--Same form as the above, substituting French lavender for the British. Recipes for Rondeletia, Lavender Bouquet, and other lavender compounds, will be given when we come to speak of compound perfumes, which will be reserved until we have finished explaining the method of making the simple essences. LEMON.--This fine perfume is abstracted from the _Citrus limonum_, by expression, from the rind of the fruit. The otto of lemons in the market is principally from Messina, where there are hundreds of acres of "lemon groves." Otto of lemons, like all the ottos of the Citrus family, is rapidly prone to oxidation when in contact with air and exposure to light; a high temperature is also detrimental, and as such is the case it should be preserved in a cool cellar. Most of the samples from the gas-heated shelves of the druggists' shops, are as much like essence of turpentine, to the smell, as that of lemons; rancid oil of lemons may, in a great measure, be purified by agitation with warm water and final decantation. When new and good, lemon otto may be freely used in combination with rosemary, cloves, and caraway, for perfuming powders for the nursery. From its rapid oxidation, it should not be used for perfuming grease, as it assists rather than otherwise all fats to turn rancid; hence pomatums so perfumed will not keep well. In the manufacture of other compound perfumes, it should be dissolved in spirit, in the proportion of six to eight ounces of oil to one gallon of spirit. There is a large consumption of otto of lemons in the manufacture of Eau de Cologne; that Farina uses it is easily discovered by adding a few drops of Liq. Ammoniæ fort. to half an ounce of his Eau de Cologne, the smell of the lemon is thereby brought out in a remarkable manner. Perhaps it is not out of place here to remark, that in attempts to discover the composition of certain perfumes, we are greatly assisted by the use of strong Liq. Ammoniæ. Certain of the essential oils combining with the Ammonia, allow those which do not do so, if present in the compound, to be smelt. LEMON GRASS.--According to Pereira, the otto in the market under this name is derived from the _Andropogon schoenanthus_ a species of grass which grows abundantly in India. It is cultivated to a large extent in Ceylon and in the Moluccas purposely for the otto, which from the plant is easily procured by distillation. Lemon grass otto, or, as it is sometimes called, oil of verbena, on account of its similarity of odor to that favorite plant, is imported into this country in old English porter and stout bottles. It is very powerful, well adapted for perfuming soaps and greases, but its principal consumption is in the manufacture of artificial essence of verbena. From its comparatively low price, great strength, and fine perfume (when diluted), the lemon grass otto may be much more used than at present, with considerable advantage to the retail shopkeeper. LILAC.--The fragrance of the flowers of this ornamental shrub is well known. The essence of lilac is obtained either by the process of maceration, or enfleurage with grease, and afterwards treating the pomatum thus formed with rectified spirit, in the same manner as previously described for cassie; the odor so much resembles tubereuse, as to be frequently used to adulterate the latter, the demand for tubereuse being at all times greater than the supply. A beautiful IMITATION OF ESSENCE OF WHITE LILAC may be compounded thus:-- Spirituous extract from tubereuse pomade, 1 pint. " of orange-flower pomade, 1/4 " Otto of almonds, 3 drops. Extract of civet, 1/2 oz. The civet is only used to give permanence to the perfume of the handkerchief. LILY.--The manufacturing perfumer rejects the advice of the inspired writer, to "consider the lilies of the field." Rich as they are in odor, they are not cultivated for their perfume. If lilies are thrown into oil of sweet almonds, or ben oil, they impart to it their sweet smell; but to obtain anything like fragrance, the infusion must be repeated a dozen times with the same oil, using fresh flowers for each infusion, after standing a day or so. The oil being shaken with an equal quantity of spirit for a week, gives up its odor to the alcohol, and thus extract of lilies _may_ be made. But how it _is_ made is thus:-- IMITATION "LILY OF THE VALLEY." Extract of tubereuse, 1/2 pint. " jasmine, 1 oz. " fleur d'orange, 2 oz. " vanilla, 3 oz. " cassie, 1/4 pint. " rose, 1/4 " Otto of almonds, 3 drops. Keep this mixture together for a month, and then bottle it for sale. It is a perfume that is very much admired. MACE.--Ground mace is used in the manufacture of some of those scented powders called Sachets. A strong-smelling essential oil may be procured from it by distillation, but it is rarely used. MAGNOLIA.--The perfume of this flower is superb; practically, however, it is of little use to the manufacturer, the large size of the blossoms and their comparative scarcity prevents their being used, but a very excellent imitation of its odor is made as under, and is that which is found in the perfumers' shops of London and Paris. IMITATION "ESSENCE OF MAGNOLIA." Spirituous extract of orange-flower pomatum, 1 pint. " " rose pomatum, 2 pints. " " tubereuse pomatum, 1/2 pint. " " violet pomatum, 1/2 " Essential oil of citron, 3 drs. " " almonds, 10 drops. MARJORAM.--The otto procured by distilling _Origanum majorana_, commonly called oil of oringeat by the French, is exceedingly powerful, and in this respect resembles all the ottos from the different species of thyme, of which the marjoram is one. One hundred weight of the dry herb yields about ten ounces of the otto. Oringeat oil is extensively used for perfuming soap, but more in France than in England. It is the chief ingredient used by Gelle Frères, of Paris, for scenting their "Tablet Monstre Soap," so common in the London shops. MEADOW SWEET.--A sweet-smelling otto can be produced by distilling the _Spiræa ulmaria_, but it is not used by perfumers. MELISSA. See BALM. MIGNONETTE.--But for the exquisite odor of this little flower, it would scarcely be known otherwise than as a weed. Sweet as it is in its natural state, and prolific in odor, we are not able to maintain its characteristic smell as an essence. Like many others, during separation from the plant, the fragrance is more or less modified; though not perfect, it still reminds the sense of the odor of the flowers. To give it that sweetness which it appears to want, a certain quantity of violet is added to bring it up to the market odor. As this plant is so very prolific in odor, we think something might be done with it in England, especially as it flourishes as well in this country as in France; and we desire to see Flower Farms and organized Perfumatories established in the British Isles, for the extraction of essences and the manufacture of pomade and oils, of such flowers as are indigenous, or that thrive in the open fields of our country. Besides opening up a new field of enterprise and good investment for capital, it would give healthy employment to many women and children. Open air employment for the young is of no little consideration to maintain the stamina of the future generation; for it cannot be denied that our factory system and confined cities are prejudicial to the physical condition of the human family. To return from our digression. The essence of mignonette, or, as it is more often sold under the name of Extrait de Rézéda, is prepared by infusing the rézéda pomade in rectified spirit, in the proportion of one pound of pomade to one pint of spirit, allowing them to digest together for a fortnight, when the essence is filtered off the pomade. One ounce of extrait d'ambré is added to every pint. This is done to give permanence to the odor upon the handkerchief, and does not in any way alter its odor. MIRIBANE.--The French name for artificial essence of almond (see ALMOND). MINT.--All the _Menthidæ_ yield fragrant ottos by distillation. The otto of the spear-mint (_M. viridis_) is exceedingly powerful, and very valuable for perfuming soap, in conjunction with other perfumes. Perfumers use the ottos of the mint in the manufacture of mouth-washes and dental liquids. The leading ingredient in the celebrated "eau Botot" is oil of peppermint in alcohol. A good imitation may be made thus:-- EAU DE BOTOT. Tincture of cedar wood, 1 pint. " myrrh, 1 oz. Oil of peppermint, 1/2 dr. " spear mint, 1/4 dr. " cloves, 10 drops. " roses, 10 " Modifications of this formula can be readily suggested, but the main object is to retain the mint ottos, as they have more power than any other aromatic to overcome the smell of tobacco. Mouth-washes, it must be remembered, are as much used for rinsing the mouth after smoking as for a dentifrice. MYRTLE.--A very fragrant otto may be procured by distilling both flowers and leaves of the common myrtle; one hundred-weight will yield about five ounces of the volatile oil. The demand for essence of myrtle being very limited, the odor as found in the perfumers' shops is very rarely a genuine article, but it is imitated thus:-- IMITATION ESSENCE OF MYRTLE. Extract of vanilla, 1/2 pint. " roses 1 " Extract of fleur d'orange, 1/2 pint. " tubereuse, 1/2 " " jasmine, 2 oz. Mix and allow to stand for a fortnight: it is then fit for bottling, and is a perfume that gives a great deal of satisfaction. Myrtle-flower water is sold in France under the name of eau d'ange, and may be prepared like rose, elder, or other flower waters. NEROLI, OR ORANGE-FLOWER.--Two distinct odors are procurable from the orange-blossom, varying according to the methods adopted for procuring them. This difference of perfume from the same flower is a great advantage to the manufacturer. This curious fact is worthy of inquiry by the chemical philosopher. It is not peculiar to the orange-flower, but applies to many others, especially rose--probably to all flowers. When orange-flowers are treated by the maceration process, that is, by infusion in a fatty body, we procure orange-flower pomatum, its strength and quality being regulated by the number of infusions of the flower made in the same grease. By digesting this orange-flower pomatum in rectified spirits in the proportions of from six pounds to eight pounds of pomade to a gallon of spirit, for about a fortnight at a summer heat, we obtain the extrait de fleur d'orange, or extract of orange-flowers, a handkerchief perfume surpassed by none. In this state its odor resembles the original so much, that with closed eyes the best judge could not distinguish the scent of the extract from that of the flower. The peculiar flowery odor of this extract renders it valuable to perfumers, not only to sell in a pure state, but slightly modified with other _extraits_ passes for "sweet pea," "magnolia," &c., which it slightly resembles in fragrance. [Illustration: Orange.] Now, when orange-flowers are distilled with water, we procure the otto of the blossom, which is known commercially as oil of neroli. The neroli procured from the flowers of the Citrus aurantium is considered to be the finest quality, and is called "neroli petale." The next quality, "neroli bigarade," is derived from the blossoms of the _Citrus bigaradia_, or Seville orange. Another quality, which is considered inferior to the preceding, is the neroli petit grain, obtained by distilling the leaves and the young unripe fruit of the different species of the citrus. The "petale" and "bigarade" neroli are used to an enormous extent in the manufacture of eau de Cologne and other handkerchief perfumes. The petit grain is mainly consumed for scenting soap. To form the esprit de neroli, dissolve 1-1/2 oz. of neroli petale in one gallon of rectified spirits. Although very agreeable, and extensively used in the manufacture of bouquets, it has no relation to the flowery odor of the extrait de fleur d'orange, as derived from the same flowers by maceration; in fact, it has as different an odor as though obtained from another plant, yet in theory both these _extraits_ are but alcoholic solutions of the otto of the flower. The water used for distillation in procuring the neroli, when well freed from the oil, is imported into this country under the name of eau de fleur d'orange, and may be used, like elder-flower and rose-water, for the skin, and as an eye lotion. It is remarkable for its fine fragrance, and it is astonishing that it is not more used, being moderate in price. (See _Syringa_.) NUTMEG.--The beautiful odor of the nutmeg is familiar to all. Though an otto can be drawn from them of a very fragrant character, it is rarely used in perfumery. The ground nuts are, however, used advantageously in the combinations of scented powders used for scent bags.--See "Sachet's Powders." OLIBANUM is a gum resin, used to a limited extent in this country, in the manufacture of incense and pastilles. It is chiefly interesting as being one of those odoriferous bodies of which frequent mention is made in the Holy volume.[C] "It is believed," says Burnett, "to have been one of the ingredients in the sweet incense of the Jews; and it is still burnt as incense in the Greek and Romish churches, where the diffusion of such odors round the altar forms a part of the prescribed religious service." Olibanum is partially soluble in alcohol, and, like most of the balsams, probably owes its perfume to a peculiar odoriferous body, associated with the benzoic acid it contains. For making the tincture or extract of olibanum, take 1 pound of the gum to 1 gallon of the spirit. ORANGE.--Under the title "Neroli" we have already spoken of the odoriferous principle of the orange-blossom. We have now to speak of what is known in the market as Essence of Orange, or, as it is more frequently termed, Essence of Portugal,--a name, however, which we cannot admit in a classified list of the "odors of plants." The otto of orange-peel, or odoriferous principle of the orange fruit, is procured by expression and by distillation. The peel is rasped in order to crush the little vessels or sacs that imprison the otto. Its abundance in the peel is shown by pinching a piece near the flame of a candle; the otto that spirts out ignites with a brilliant illumination. It has many uses in perfumery, and from its refreshing fragrance finds many admirers. It is the leading ingredient in what is sold as "Lisbon Water" and "Eau de Portugal." The following is a very useful form for preparing LISBON WATER. Rectified spirit (not less than 60 over proof), 1 gallon. Otto of orange peel, 3 oz. " lemon peel, 3 oz. " rose 1/4 oz. This is a form for EAU DE PORTUGAL. Rectified spirit (60 over proof), 1 gallon. Essential oil of orange peel, 6 oz. " lemon peel, 1 oz. " lemon grass, 1/4 oz. " bergamot, 1 oz. " otto of rose, 1/4 oz. It should be noted that these perfumes are never to be filled into wet bottles, for if in any way damp from water, a minute portion of the ottos are separated, which gives an opalescent appearance to the mixture. Indeed, all bottles should be _spirit rinsed_ prior to being filled with any perfume, but especially with those containing essences of orange or lemon peel. ORRIS, properly IRIS.--The dried rhizome of _Iris florentina_ has a very pleasant odor, which, for the want of a better comparison, is said to resemble the smell of violets; it is, however, exceedingly derogatory to the charming aroma of that modest flower when such invidious comparisons are made. Nevertheless the perfume of iris root is good, and well worthy of the place it has obtained as a perfuming substance. The powder of orris root is very extensively used in the manufacture of sachet powders, tooth-powder, &c. It fathers that celebrated "oriental herb" known as "Odonto." For tincture of orris, or, as the perfumers call it, EXTRACT OF ORRIS, Take orris root, crushed, 7 lbs. Rectified spirits, 1 gallon. After standing together for about a fortnight, the extract is fit to take off. It requires considerable time to drain away, and, to prevent loss, the remainder of the orris should be placed in the tincture press. This extract enters into the composition of many of the most celebrated bouquets, such as "Jockey Club," and others, but is never sold alone, because its odor, although grateful, is not sufficiently good to stand public opinion upon its own merits; but in combination its value is very great; possessing little aroma itself, yet it has the power of strengthening the odor of other fragrant bodies; like the flint and steel, which though comparatively incombustible, readily fire inflammable bodies. PALM.--The odor of palm oil--the fat oil of commerce--is due to a fragrant principle which it contains. By infusion in alcohol, the odoriferous body is dissolved, and resembles, to a certain extent, the tincture of orris, or of extract of violet, but is very indifferent, and is not likely to be brought into use, though several attempts have been made to render it of service when the cultivation of the violets have failed from bad seasons. PATCHOULY.--_Pogostemon patchouly_ (LINDLEY), _Plectranthus crassifolius_ (BURNETT), is an herb that grows extensively in India and China. It somewhat resembles our garden sage in its growth and form, but the leaves are not so fleshy. [Illustration: Patchouly.] The odor of patchouly is due to an otto contained in the leaves and stems, and is readily procured by distillation. 1 cwt. of good herb will yield about 28 oz. of the essential oil, which is of a dark brown color, and of a density about the same as that of oil of sandal wood, which it resembles in its physical character. Its odor is the most powerful of any derived from the botanic kingdom; hence, if mixed in the proportion of measure for measure, it completely covers the smell of all other bodies. EXTRACT OF PATCHOULY. Rectified spirit, 1 gallon. Otto of patchouly, 1-1/4 oz. " rose, 1/4 oz. The essence of patchouly thus made is that which is found in the perfumers' shops of Paris and London. Although few perfumes have had such a fashionable run, yet when smelled at in its pure state, it is far from agreeable, having a kind of mossy or musty odor, analogous to Lycopodium, or, as some say, it smells of "old coats." The characteristic smell of Chinese or Indian ink is due to some admixture of this herb. The origin of the use of patchouly as a perfume in Europe is curious. A few years ago real Indian shawls bore an extravagant price, and purchasers could always distinguish them by their odor; in fact, they were perfumed with patchouly. The French manufacturers had for some time successfully imitated the Indian fabric, but could not impart the odor. At length they discovered the secret, and began to import the plant to perfume articles of their make, and thus palm off homespun shawls as real Indian! From this origin the perfumers have brought it into use. Patchouly herb is extensively used for scenting drawers in which linen is kept; for this purpose it is best to powder the leaves and put them into muslin sacks, covered with silk, after the manner of the old-fashioned lavender-bag. In this state it is very efficacious in preventing the clothes from being attacked by moths. Several combinations of patchouly will be given in the recipes for "bouquets and nosegays." PEA (SWEET).--A very fine odor may be abstracted from the flowers of the chick-vetch by maceration in any fatty body, and then digesting the pomade produced in spirit. It is, however, rarely manufactured, because a very close IMITATION OF THE ESSENCE OF SWEET PEA. can be prepared thus:-- Extract of tuberose, 1/2 pint. " fleur d'orange, 1/2 " " rose from pomatum, 1/2 " " vanilla, 1 oz. Scents, like sounds, appear to influence the olfactory nerve in certain definite degrees. There is, as it were, an octave of odors like an octave in music; certain odors coincide, like the keys of an instrument. Such as almond, heliotrope, vanilla, and orange-blossoms blend together, each producing different degrees of a nearly similar impression. Again, we have citron, lemon, orange-peel, and verbena, forming a higher octave of smells, which blend in a similar manner. The metaphor is completed by what we are pleased to call semi-odors, such as rose and rose geranium for the half note; petty grain, neroli, a black key, followed by fleur d'orange. Then we have patchouli, sandal-wood, and vitivert, and many others running into each other. From the odors already known we may produce, by uniting them in proper proportion, the smell of almost any flower, except jasmine. The odor of some flowers resembles others so nearly that we are almost induced to believe them to be the same thing, or, at least, if not evolved from the plant as such, to become so by the action of the air-oxidation. It is known that some actually are identical in composition, although produced from totally different plants, such as camphor, turpentine, rosemary. Hence we may presume that chemistry will sooner or later produce one from the other, for with many it is merely an atom of water or an atom of oxygen that causes the difference. It would be a grand thing to produce otto of roses from oil of rosemary, or from the rose geranium oil, and theory indicates its possibility. The essential oil of almonds in a bottle that contains a good deal of air-oxygen, and but a very little of the oil, spontaneously passes into another odoriferous body, benzoic acid; which is seen in crystals to form over the dry parts of the flask. This is a natural illustration of this idea. In giving the recipe for "sweet pea" as above, we form it with the impression that its odor resembles the orange-blossom, which similarity is approached nearer by the addition of the rose and tuberose. The vanilla is used merely to give permanence to the scent on the handkerchief, and this latter body is chosen in preference to extract of musk or ambergris, which would answer the same purpose of giving permanence to the more volatile ingredients; because the vanilla strikes the same key of the olfactory nerve as the orange-blossom, and thus no new idea of a different scent is brought about as the perfume dies off from the handkerchief. When perfumes are not mixed upon this principle, then we hear that such and such a perfume becomes "sickly" or "faint" after they have been on the handkerchief a short time. PINE-APPLE.--Both Dr. Hoffman and Dr. Lyon Playfair have fallen into some error in their inferences with regard to the application of this odor in perfumery. After various practical experiments conducted in a large perfumatory, we have come to the conclusion that it cannot be so applied, simply because when the essence of pine-apple is smelled at, the vapor produces an involuntary action of the larynx, producing cough, when exceedingly dilute. Even in the infinitesimal portions it still produces disagreeable irritation of the air-pipes, which, if prolonged, such as is expected if used upon a handkerchief, is followed by intense headache. It is obvious, therefore, that the legitimate use of the essence of pine-apple (butyric ether) cannot be adapted with benefit to the manufacturing perfumer, although invaluable to the confectioner as a flavoring material. What we have here said refers to the artificial essence of pine-apple, or butyrate of ethyloxide, which, if very much diluted with alcohol, resembles the smell of pine-apple, and hence its name; but how far the same observations are applicable to the true essential oil from the fruit or epidermis of the pine-apple, remains to be seen _when_ we procure it. As the West Indian pine-apples are now coming freely into the market, the day is probably not distant when demonstrative experiments can be tried; but hitherto it must be remembered our experiments have only been performed with a body _resembling in smell_ the true essential oil of the fruit. The physical action of all ethers upon the human body is quite sufficient to prevent their application in perfumery, however useful in confectionary, which it is understood has to deal with another of the senses,--not of smell, but of taste. The commercial "essence of pine-apple," or "pine-apple oil," and "jargonelle pear-oil," are admitted only to be _labelled_ such, but really are certain organic acid ethers. For the present, then, perfumers must only look on these bodies as so many lines in the "Poetry of Science," which, for the present, are without practical application in his art. PINK.--_Dianthus Caryophyllus._--The clove pink emits a most fragrant odor, "especially at night," says Darwin. "The lavish pink that scents the garden round," is not, however, at present applied in perfumery, except in name. IMITATION ESSENCE OF CLOVE PINK. Esprit rose, 1/2 pint. " fleur d'orange, 1/4 " " " de cassie, 1/4 " " vanilla, 2 oz. Oil of cloves, 10 drops. It is remarkable how very much this mixture resembles the odor of the flower, and the public never doubt its being the "real thing." RHODIUM.--When rose-wood, the lignum of the _Convolvulus scoparius_, is distilled, a sweet-smelling oil is procured, resembling in some slight degree the fragrance of the rose, and hence its name. At one time, that is, prior to the cultivation of the rose-leaf geranium, the distillates from rose-wood and from the root of the _Genista canariensis_ (Canary-rose-wood), were principally drawn for the adulteration of real otto of roses, but as the geranium oil answers so much better, the oil of rhodium has fallen into disuse, hence its comparative scarcity in the market at the present day, though our grandfathers knew it well. One cwt. of wood yields about three ounces of oil. Ground rose-wood is valuable as a basis in the manufacture of sachet powders for perfuming the wardrobe. The French have given the name jacaranda to rose-wood, under the idea that the plant called jacaranda by the Brazilians yields it, which is not the case; "the same word has perhaps been the origin of palisander--palixander, badly written."--_Burnett_. ROSE.-- "Go, crop the gay rose's vermeil bloom, And waft its spoils, a sweet perfume, In incense to the skies." OGILVIE. This queen of the garden loses not its diadem in the perfuming world. The oil of roses, or, as it is commonly called, the otto, or attar, of roses, is procured (contrary to so many opposite statements) simply by distilling the roses with water. The otto, or attar, of rose of commerce is derived from the _Rosa centifolia provincialis_. Very extensive rose farms exist at Adrianople (Turkey in Europe); at Broussa, now famous as the residence of Abd-el-Kader; and at Uslak (Turkey in Asia); also at Ghazepore, in India. The cultivators in Turkey are principally the Christian inhabitants of the low countries of the Balkan, between Selimno, and Carloya, as far as Philippopolis, in Bulgaria, about 200 miles from Constantinople. In good seasons, this district yields 75,000 ounces; but in bad seasons only 20,000 to 30,000 ounces of attar are obtained. It is estimated that it requires at least 2000 rose blooms to yield one drachm of otto. The otto slightly varies in odor from different districts; many places furnish an otto which solidifies more readily than others, and, therefore, this is not a sure guide of purity, though many consider it such. That which was exhibited in the Crystal Palace of 1851, as "from Ghazepore," in India, obtained the prize. "Attar of roses, made in Cashmere, is considered superior to any other; a circumstance not surprising, as, according to Hugel, the flower is here produced of surpassing fragrance as well as beauty. A large quantity of rose-water twice distilled is allowed to run off into an open vessel, placed over night in a cool running stream, and in the morning the oil is found floating on the surface in minute specks, which are taken off very carefully by means of a blade of sword-lily. When cool it is of a dark green color, and as hard as resin, not becoming liquid at a temperature about that of boiling water. Between 500 and 600 pounds' weight of leaves is required to produce one ounce of the attar."--_Indian Encyclopædia._ Pure otto of roses, from its cloying sweetness, has not many admirers; when diluted, however, there is nothing to equal it in odor, especially if mixed in soap, to form rose soap, or in pure spirit, to form the esprit de rose. The soap not allowing the perfume to evaporate very fast, we cannot be surfeited with the smell of the otto. The finest preparation of rose as an odor is made at Grasse, in France. Here the flowers are not treated for the otto, but are subjected to the process of maceration in fat, or in oil, as described under jasmine, heliotrope, &c. The rose pomade thus made, if digested in alcohol, say 8 lbs. of No. 24 Pomade to one gallon of spirit, yields an esprit de rose of the first order, very superior to that which is made by the addition of otto to spirit. It is difficult to account for this difference, but it is sufficiently characteristic to form a distinct odor. See the article on fleur d'orange and neroli (pp. 77, 78), which have similar qualities, previously described. The esprit de rose made from the French rose pomade is never sold retail by the perfumer; he reserves this to form part of his _recherche_ bouquets. Some wholesale druggists have, however, been selling it now for some time to country practitioners, for them to form extemporaneous rose-water, which it does to great perfection. Roses are cultivated to a large extent in England, near Mitcham, in Surrey, for perfumers' use, to make rose-water. In the season when successive crops can be got, which is about the end of June, or the early part of July, they are gathered as soon as the dew is off, and sent to town in sacks. When they arrive, they are immediately spread out upon a cool floor: otherwise, if left in a heap, they heat to such an extent, in two or three hours, as to be quite spoiled. There is no organic matter which so rapidly absorbs oxygen, and becomes heated spontaneously, as a mass of freshly gathered roses. To preserve these roses, the London perfumers immediately pickle them; for this purpose, the leaves are separated from the stalks, and to every bushel of flowers, equal to about six pounds' weight, one pound of common salt is thoroughly rubbed in. The salt absorbs the water existing in the petals, and rapidly becomes brine, reducing the whole to a pasty mass, which is finally stowed away in casks. In this way they will keep almost any length of time, without the fragrance being seriously injured. A good rose-water can be prepared by distilling 12 lbs. of pickled roses, and 2-1/2 gallons of water. "Draw" off two gallons; the product will be the double-distilled rose-water of the shops. The rose-water that is imported from the South of France is, however, very superior in odor to any that can be produced here. As it is a residuary product of the distillation of roses for procuring the attar, it has a richness of aroma which appears to be inimitable with English-grown roses. There are four modifications of essence of rose for the handkerchief, which are the _ne plus ultra_ of the perfumer's art. They are,--esprit de rose triple, essence of white of roses, essence of tea rose, and essence of moss rose. The following are the recipes for their formation:-- ESPRIT DE ROSE TRIPLE. Rectified alcohol, 1 gallon. Otto of rose, 3 oz. Mix at a summer heat; in the course of a quarter of an hour the whole of the otto is dissolved, and is then ready for bottling and sale. In the winter season beautiful crystals of the otto--if it is good--appear disseminated through the esprit. ESSENCE OF MOSS ROSE. Spirituous extract from French Rose pomatum, 1 quart. Esprit de rose triple, 1 pint. Extracts fleur d'orange pomatum, 1 " " of ambergris, 1/2 " " musk, 4 oz. Allow the ingredients to remain together for a fortnight; then filter, if requisite, and it is ready for sale. ESSENCE OF WHITE ROSE. Esprit de rose from pomatum, 1 quart. " " triple, 1 " " violette, 1 " Extracts of jasmine 1 pint. " patchouly, 1/2 " ESSENCE OF TEA ROSE. Esprit de rose pomade, 1 pint. " " triple, 1 " Extract of rose-leaf geranium, 1 " " sandal-wood, 1/2 " " neroli, 1/4 " " orris, 1/4 " ROSEMARY.-- "There's rosemary, that's for remembrance." SHAKSPEARE. By distilling the _Rosmarinus officinalis_ a thin limpid otto is procured, having the characteristic odor of the plant, which is more aromatic than sweet. One cwt. of the fresh herb yields about twenty-four ounces of oil. Otto of rosemary is very extensively used in perfumery, especially in combination with other ottos for scenting soap. Eau de Cologne cannot be made without it, and in the once famous "Hungary water" it is the leading ingredient. The following is the composition of HUNGARY WATER. Rectified alcohol, 1 gallon. Otto of English rosemary, 2 oz. " lemon-peel, 1 oz. " balm (_Melissa_), 1 oz. " mint, 1/2 drachm. Esprit de rose, 1 pint. Extract of fleur d'orange, 1 " It is put up for sale in a similar way to eau de Cologne, and is said to take its name from one of the queens of Hungary, who is reported to have derived great benefit from a bath containing it, at the age of seventy-five years. There is no doubt that clergymen and orators, while speaking for any time, would derive great benefit from perfuming their handkerchief with Hungary water or eau de Cologne, as the rosemary they contain excites the mind to vigorous action, sufficient of the stimulant being inhaled by occasionally wiping the face with the handkerchief wetted with these "waters." Shakspeare giving us the key, we can understand how it is that such perfumes containing rosemary are universally said to be "so refreshing!" SAGE.--A powerful-scenting otto can be procured by distillation from any of the _Salvieæ_. It is rarely used, but is nevertheless very valuable in combination for scenting soap. Dried sage-leaves, ground, will compound well for sachets. SANTAL.--_Santalum album_. "The santal tree perfumes, when riven, The axe that laid it low." CAMERON. This is an old favorite with the lovers of scent; it is the wood that possesses the odor. The finest santal-wood grows in the island of Timor, and the Santal-wood Islands, where it is extensively cultivated for the Chinese market. In the religious ceremonies of the Brahmins, Hindoos, and Chinese, santal-wood is burned, by way of incense, to an extent almost beyond belief. The _Santala_ grew plentifully in China, but the continued offerings to the Buddahs have almost exterminated the plant from the Celestial Empire; and such is the demand, that it is about to be cultivated in Western Australia, in the expectation of a profitable return, which we doubt not will be realized; England alone would consume tenfold the quantity it does were its price within the range of other perfuming substances. The otto which exists in the santal-wood is readily procured by distillation; 1 cwt. of good wood will yield about 30 ounces of otto. [Illustration: Santal-wood.] The white ant, which is so common in India and China, eating into every organic matter that it comes across, appears to have no relish for santal-wood; hence it is frequently made into caskets, jewel-boxes, deed-cases, &c. This quality, together with its fragrance, renders it a valuable article to the cabinet-makers of the East. The otto of santal is remarkably dense, and is above all others oleaginous in its appearance, and, when good, is of a dark straw color. When dissolved in spirit, it enters into the composition of a great many of the old-fashioned bouquets, such as "Marechale," and others, the formulæ of which will be given hereafter. Perfumers thus make what is called EXTRAIT DE BOIS DE SANTAL. Rectified spirits, 7 pints. Esprit de rose, 1 pint. Essential oil, _i.e._ otto, of santal, 3 oz. All those EXTRACTS, made by dissolving the otto in alcohol, are nearly white, or at least only slightly tinted by the color of the oil used. When a perfumer has to impart a delicate _odeur_ to a lady's _mouchoir_, which in some instances costs "no end of money," and is an object, at any cost, to retain unsullied, it behooves his reputation to sell an article that will not stain a delicate white fabric. Now, when a perfume is made in a direct manner from any wood or herb, as tinctures are made, that is, by infusion in alcohol, there is obtained, besides the odoriferous substance, a solution of coloring and extractive matter, which is exceedingly detrimental to its fragrance, besides seriously staining any cambric handkerchief that it may be used upon; and for this reason this latter method should never be adopted, except for use upon silk handkerchiefs. The odor of santal assimilates well with rose; and hence, prior to the cultivation of rose-leaf geranium, it was used to adulterate otto of roses; but is now but seldom used for that purpose. By a "phonetic" error, santal is often printed "sandal," and "sandel." SASSAFRAS.--Some of the perfumers of Germany use a tincture of the wood of the _Laurus sassafras_ in the manufacture of hair-washes and other nostrums; but as, in our opinion, it has rather a "physicky" smell than flowery, we cannot recommend the German recipes. The _Eau Athenienne_, notwithstanding, has some reputation as a hair-water, but is little else than a weak tincture of sassafras. SPIKE.--French oil of lavender, which is procured from the _Lavandula spica_, is generally called oil of spike. (See Lavender.) STORAX and TOLU are used in perfumery in the same way as benzoin, namely, by solution in spirit as a tincture. An ounce of tincture of storax, tolu, or benzoin, being added to a pound of any very volatile perfume, gives a degree of permanence to it, and makes it last longer on the handkerchief than it otherwise would: thus, when any perfume is made by the solution of an otto in spirit, it is usual to add to it a small portion of a substance which is less volatile, such as extract of musk, extract of vanilla, ambergris, storax, tolu, orris, vitivert, or benzoin; the manufacturer using his judgment and discretion as to which of these materials are to be employed, choosing, of course, those which are most compatible with the odor he is making. The power which these bodies have of "fixing" a volatile substance, renders them valuable to the perfumer, independent of their aroma, which is due in many cases to benzoic acid, slightly modified by an esential oil peculiar to each substance, and which is taken up by the alcohol, together with a portion of resin. When the perfume is put upon a handkerchief, the most volatile bodies disappear first: thus, after the alcohol has evaporated, the odor of the ottos appear stronger; if it contains any resinous body, the ottos are held in solution, as it were, by the resin, and thus retained on the fabric. Supposing a perfume to be made of otto only, without any "fixing" substance, then, as the perfume "dies away," the olfactory nerve, if tutored, will detect its composition, for it spontaneously analyzes itself, no two ottos having the same volatility: thus, make a mixture of rose, jasmine, and patchouly; the jasmine predominates first, then the rose, and, lastly, the patchouly, which will be found hours after the others have disappeared. SYRINGA.--The flowers of the _Philadelphus coronarius_, or common garden syringa, have an intense odor resembling the orange-blossom; so much so, that in America the plant is often termed "mock orange." A great deal of the pomatum sold as pommade surfin, à la fleur d'orange, by the manufacturers of Cannes, is nothing more than fine suet perfumed with syringa blossoms by the maceration process. Fine syringa pomade could be made in England at a quarter the cost of what is paid for the so-called orange pomatum. THYME.--All the different species of thyme, but more particularly the lemon thyme, the _Thymus serpyllum_, as well as the marjorams, origanum, &c., yield by distillation fragrant ottos, that are extensively used by manufacturing perfumers for scenting soaps; though well adapted for this purpose, they do not answer at all in any other combinations. Both in grease and in spirit all these ottos impart an herby smell (very naturally) rather than a flowery one, and, as a consequence, they are not considered _recherché_. When any of these herbs are dried and ground, they usefully enter into the composition of sachet powders. TONQUIN, or TONKA.--The seeds of the _Dipterix odorata_ are the tonquin or _coumarouma_ beans of commerce. When fresh they are exceedingly fragrant, having an intense odor of newly made hay. The _Anthoxanthum odoratum_, or sweet-smelling vernal grass, to which new hay owes its odor, probably yields identically the same fragrant principle, and it is remarkable that both tonquin beans and vernal grass, while actually growing, are nearly scentless, but become rapidly aromatic when severed from the parent stock. Chemically considered, tonquin beans are very interesting, containing, when fresh, a fragrant volatile otto (to which their odor is principally due), benzoic acid, a fat oil and a neutral principal--_Coumarin_. In perfumery they are valuable, as, when ground, they form with other bodies an excellent and permanent sachet, and by infusion in spirit, the tincture or extract of tonquin enters into a thousand of the compound essences; but on account of its great strength it must be used with caution, otherwise people say your perfume is "snuffy," owing to the predominance of the odor and its well-known use in the boxes of those who indulge in the titillating dust. [Illustration: Tonquin.] EXTRACT OF TONQUIN. Tonquin beans, 1 lb. Rectified spirit, 1 gallon. Digest for a month at a summer heat. Even after this maceration they are still useful when dried and ground in those compounds known as POT POURRI, OLLA PODRIA, &c. The extract of tonquin, like extract of orris and extract of vanilla, is never sold pure, but is only used in the manufacture of compound perfumes. It is the leading ingredient in _Bouquet du Champ_--The field Bouquet--the great resemblance of which to the odor of the hay-field, renders it a favorite to the lovers of the pastoral. TUBEROSE.--One of the most exquisite odors with which we are acquainted is obtained by _enfleurage_ from the tuberose flower. It is, as it were, a nosegay in itself, and reminds one of that delightful perfume observed in a well-stocked flower-garden at evening close; consequently it is much in demand by the perfumers for compounding sweet essences. EXTRACT OF TUBEROSE. Eight pounds of No. 24 tuberose pomatum, cut up very fine, is to be placed into 1 gallon of the best rectified spirit. After standing for three weeks or a month at summer heat, and with frequent agitation, it is fit to draw off, and being strained through cotton wool, is ready either for sale or use in the manufacture of bouquets. This essence of tuberose, like that of jasmine, is exceedingly volatile, and if sold in its pure state quickly "flies off" the handkerchief; it is therefore necessary to add some fixing ingredient, and for this purpose it is best to use one ounce of extract of orris, or half an ounce of extract of vanilla, to every pint of tuberose. VANILLA.--The pod or bean of the _Vanilla planifolia_ yields a perfume of rare excellence. When good, and if kept for some time, it becomes covered with an efflorescence of needle crystals possessing properties similar to benzoic acid, but differing from it in composition. Few objects are more beautiful to look upon than this, when viewed by a microscope with the aid of polarized light. [Illustration: Vanilla.] EXTRACT OF VANILLA. Vanilla pods, 1/2 lb. Rectified spirit, 1 gallon. Slit the pods from end to end, so as to lay open the interior, then cut them up in lengths of about a quarter of an inch, macerate with occasional agitation for about a month; the tincture thus formed will only require straining through cotton to be ready for any use that is required. In this state it is rarely sold for a perfume, but is consumed in the manufacture of compound odors, bouquets, or nosegays, as they are called. Extract of Vanilla is also used largely in the manufacture of hair-washes, which are readily made by mixing the extract of vanilla with either rose, orange, elder, or rosemary water, and afterwards filtering. We need scarcely mention, that vanilla is greatly used by cooks and confectioners for flavoring. VERBENA, or VERVAINE.--The scented species of this plant, the lemon verbena, _Aloysia citriodora_ (Hooker), gives one of the finest perfumes with which we are acquainted; it is well known as yielding a delightful fragrance by merely drawing the hand over the plant; some of the little vessels or sacks containing the otto must be crushed in this act, as there is little or no odor by merely smelling at the plant. The otto, which can be extracted from the leaves by distillation with water, on account of its high price, is scarcely, if ever, used by the manufacturing perfumer, but it is most successfully imitated by mixing the otto of lemon grass, _Andropogon schoenanthus_, with rectified spirit, the odor of which resembles the former to a nicety. The following is a good form for making the EXTRACT OF VERBENA. Rectified spirit, 1 pint. Otto of lemon grass, 3 drachms. " lemon peel, 2 oz. " orange peel, 1/2 oz. After standing together for a few hours and then filtering, it is fit for sale. Another mixture of this kind, presumed by the public to be made from the same plant, but of a finer quality, is composed thus--it is sold under the title EXTRAIT DE VERVEINE. Rectified spirit, 1 pint. Otto of orange peel, 1 oz. " lemon peel, 2 oz. " citron, 1 drachm. " lemon grass, 2-1/2 drachms. Extrait de fleur d'orange, 7 oz. " " tubereuse, 7 oz. Esprit de rose, 1/2 pint. This mixture is exceedingly refreshing, and is one of the most elegant perfumes that is made. Being white, it does not stain the handkerchief. It is best when sold fresh made, as by age the citrine oils oxidize, and the perfume acquires an ethereal odor, and then customers say "it is sour." The vervaine thus prepared enters into the composition of a great many of the favorite bouquets that are sold under the title "Court Bouquet," and others which are mixtures of violet, rose, and jasmine, with verbena or vervaine in different proportions. In these preparations, as also in Eau de Portugal, and in fact where any of the citrine ottos are used, a much finer product is obtained by using grape spirit or brandy in preference to the English corn spirit as a solvent for them. Nor do they deteriorate so quickly in French spirit as in English. Whether this be due to the oil of wine (oeanthic ether) or not we cannot say, but think it is so. VIOLET.-- "The forward violet thus did I chide: Sweet thief, whence didst thou steal thy sweet that smells, If not from my love's breath?" The perfume exhaled by the _Viola odorata_ is so universally admired, that to speak in its favor would be more than superfluous. The demand for the "essence of violets" is far greater than the manufacturing perfumers are at present able to supply, and as a consequence, it is difficult to procure the genuine article through the ordinary sources of trade. Real violet is, however, sold by many of the retail perfumers of the West End of London, but at a price that prohibits its use except by the affluent or extravagant votaries of fashion. The violet farms from whence the flowers are procured to make this perfume are very extensive at Nice and Grasse, also in the neighborhood of Florence. The true smelling principle or otto of violets has never yet been isolated: a very concentrated solution in alcohol impresses the olfactory nerve with the idea of the presence of hydrocyanic acid, which is probably a true impression. Burnett says that the plant _Viola tricolor_ (heart's ease), when bruised, smells like peach kernels, and doubtless, therefore, contains prussic acid. The flowers of the heart's ease are scentless, but the plant evidently contains a principle which in other species of the Viola, is eliminated as the "sweet that smells" so beautifully alluded to by Shakspeare. For commercial purposes, the odor of the violet is procured in combination with spirit, oil, or suet, precisely according to the methods previously described for obtaining the aroma of some other flowers before mentioned, such as those for cassie, jasmine, orange-flower, namely, by maceration, or by _enfleurage_, the former method being principally adopted, followed by, when "essence" is required, digesting the pomade in rectified alcohol. Good essence of violets, thus made, is of a beautiful green color, and, though of a rich deep tint, has no power to stain a white fabric, and its odor is perfectly natural. The essence of violet, as prepared for retail sale, is thus made, according to the quality and strength of the pomade:--Take from six to eight pounds of the violet pomade, chop it up fine, and place it into one gallon of perfectly clean (free from fusel oil) rectified spirit, allow it to digest for three weeks or a month, then strain off the essence, and to every pint thereof add three ounces of tincture of orris root, and three ounces of esprit de cassie; it is then fit for sale. We have often seen displayed for sale in druggists' shops plain tincture of orris root, done up in nice bottles, with labels upon them inferring the contents to be "Extract of Violet;" customers thus once "taken in" are not likely to be so a second time. A good IMITATION ESSENCE OF VIOLETS is best prepared thus-- Spirituous extract of cassie pomade, 1 pint. Esprit de rose, from pomade, 1/2 " Tincture of orris, 1/2 " Spirituous extract of tuberose pomade, 1/2 " Otto of almonds, 3 drops. After filtration it is fit for bottling. In this mixture, it is the extract of cassie which has the leading smell, but modified by the rose and tuberose becomes very much like the violet. Moreover, it has a green color, like the extract of violet; and as the eye influences the judgment by the sense of taste, so it does with the sense of smell. Extract of violet enters largely into the composition of several of the most popular bouquets, such as extract of spring flowers and many others. VITIVERT, or Kus-Kus, is the rhizome of an Indian grass. In the neighborhood of Calcutta, and in the city, this material has an extensive use by being manufactured into awnings, blinds, and sun-shades, called Tatty. During the hot seasons an attendant sprinkles water over them; this operation cools the apartment by the evaporation of the water, and, at the same time, perfumes the atmosphere, in a very agreeable manner, with the odoriferous principle of the vitivert. It has a smell between the aromatic or spicy odor and that of flowers--if such a distinction can be admitted. We classify it with orris root, not that it has any odor resembling it, but because it has a like effect in use in perfumery, and because it is prepared as a tincture for obtaining its odor. About four pounds of the dried vitivert, as it is imported, being cut small and set to steep in a gallon of rectified spirits for a fortnight, produces the ESSENCE OF VITIVERT of the shops. In this state it is rarely used as a perfume, although it is occasionally asked for by those who, perhaps, have learnt to admire its odor by their previous residence in "the Eastern clime." The extract, essence, or tincture of vitivert, enters into the composition of several of the much-admired and old bouquets manufactured in the early days of perfumery in England, such as "_Mousselaine des Indies_," for which preparation M. Delcroix, in the zenith of his fame, created quite a _furor_ in the fashionable world. [Illustration: Vitivert.] Essence of vitivert is also made by dissolving 2 oz. of otto of vitivert in 1 gallon of spirit; this preparation is stronger than the tincture, as above. MARECHALE and BOUQUET DU ROI, perfumes which have also "had their day," owe much of their peculiarity to the vitivert contained in them. Bundles of vitivert are sold for perfuming linen and preventing moth, and, when ground, is used to manufacture certain sachet powders. Otto of vitivert is procurable by distillation; a hundred-weight of vitivert yields about 14 oz. of otto, which in appearance very much resembles otto of santal. I have placed a sample of it in the museum at Kew. VOLKAMERIA.--An exquisite perfume is sold under this name, presumed, of course, to be derived from the _Volkameria inermis_ (LINDLEY). Whether it has a smell resembling the flower of that plant, or whether the plant blooms at all, we are unable to say. It is a native of India, and seems to be little known even in the botanic gardens of this country; however, the plant has a name, and that's enough for the versatile Parisian perfumer, and if the mixture he makes "takes" with the fashionable world--the plant which christens it has a fine perfume for a certainty! ESSENCE OF VOLKAMERIA. Esprit de violette, 1 pint. " tubereuse, 1 " " jasmine, 1/4 " " rose, 1/2 " Essence de muse, 2 oz. WALLFLOWER (_Cherianthus_).--Exquisite as is the odor of this flower, it is not used in perfumery, though no doubt it might be, and very successfully too, were the plant cultivated for that purpose. To this flower we would direct particular attention, as one well adapted for experiments to obtain its odoriferous principle in this country, our climate being good for its production. The mode for obtaining its odor has been indicated when we spoke of heliotrope, page 60. And if it answers on the small scale, there is little doubt of success in the large way, and there is no fear but that the scent of the old English wallflower will meet with a demand. An IMITATION ESSENCE OF WALLFLOWER can be compounded thus:-- Extract fleur d'orange, 1 pint. " vanilla, 1/2 " Esprit de rose, 1 " Extract of orris, 1/2 " " cassie, 1/2 " Essential oil of almonds, 5 drops. Allow this mixture to be made up for two or three weeks prior to putting it up for sale. WINTER GREEN (_Trientalis Europoea_).--A perfuming otto can be procured by distilling the leaves of this plant: it is principally consumed in the perfuming of soaps. Upon the strength of the name of this odorous plant a very nice handkerchief perfume is made. ICELAND WINTER GREEN. Esprit de rose, 1 pint. Essence of lavender, 1/4 " Extract of neroli, 1/2 " " vanilla, 1/4 " " vitivert, 1/4 " " cassie, 1/2 " " ambergris, 1/4 " We have now described all the important odoriferous bodies which are used by the manufacturing perfumer, as derived from the botanic kingdom; it may be understood that where an odoriferous material is unnoticed, it has no qualities peculiar enough to be remarked on, and that the methods adopted for preparing its essence, extract, water, or oil, are analogous to those that have been already noticed, that is, by the processes of _maceration_, _absorption_, or _enfleurage_ for flowers, by _tincturation_ for roots, and by _distillation_ for seeds, modified under certain circumstances. There are, however, three other important derivative odors--ambergris, civet, and musk--which, being from the animal kingdom, are treated separately from plant odors, in order, it is considered, to render the whole matter less confused to manufacturers who may refer to them. Ammonia and acetic acid, holding an indefinite position in the order we have laid down, may also come in here without much criticism, being considered as primitive odors. On terminating our remarks relating to the simple preparations of the odors of plants, and before we speak of perfumes of an animal origin, or of those compound _odors_ sold as bouquets, nosegays, &c., it may probably be interesting to give a few facts and statistics, showing the consumption, in England, of the several substances previously named. QUANTITIES OF ESSENTIAL OILS, OR OTTOS, PAYING 1_S._ PER POUND DUTY, ENTERED FOR HOME CONSUMPTION IN THE YEAR 1852. lbs. Otto of bergamot, 28,574 " caraway, 3,602 " cassia, 6,163 " cloves, 595 Otto of lavender, 12,776 " lemon, 67,348 " peppermint, 16,059 " roses, 1,268 " spearmint, 163 " thyme, 11,418 " lemon grass, } " citronella, } 47,380 And other ottos not otherwise described, } ------- Total essential oils or ottos imported in one year, 195,346 at the duty of 1_s._ per pound, yield a revenue annually of 9,766_l._ 16_s._ It would appear by the above return that our consumption of otto of cloves was exceedingly small; whereas it is probably ten times that amount. The fact is, several of the English wholesale druggists are very large distillers of this otto, leaving little or no room for the sale and importation of foreign distilled otto of cloves. Again, otto of caraway, the English production of that article is quite equal to the foreign; also, otto of lavender, which is drawn in this country probably to the extent of 6000 lbs. annually. There were also passed through the Custom House for home consumption, in 1852-- Pomatums, procured by enfleurage, maceration, &c., commonly called "French Pomatums," average value of 6_s._ per pound, and paying a duty of 1_s._ per pound, valued by the importers at £1,306 Perfumery not otherwise described; value £1,920 Number of bottles of eau de Cologne, paying a duty of 1_s._ each,[D] 19,777 Revenue from eau de Cologne manufactured out of England, say 20,000 flacons at 8_d._ = 8,000_l._ annually. The total revenue derived from various sources, even upon this low scale of duties, from the substances with which "Britannia perfumes her pocket handkerchief," cannot be estimated at less than 40,000_l._ per annum. This, of course, includes the duty upon the spirits used in the home manufacture of perfumery. SECTION IV. PERFUMES OF ANIMAL ORIGIN. In the previous articles we have only spoken of the odors of plants; we now enter upon those materials used in perfumery of an animal origin. The first under our notice is-- AMBERGRIS.--This substance is found in the sea, floating near the islands of Sumatra, Molucca, and Madagascar; also on the coasts of America, Brazil, China, Japan, and the Coromandel. The western coast of Ireland is often found to yield large pieces of this substance. The shores of the counties of Sligo, Mayo, Kerry, and the isles of Arran, are the principal places where it has been found. In the "Philosophical Transactions" there is an account of a lump found on the beach of the first-mentioned county, in the year 1691, which weighed 52 oz., and was bought on the spot for 20_l._, but which afterwards was sold in London for more than 100_l._ (Philos. Trans. No. 227, p. 509). We are quite within limit in stating that many volumes concerning the origin of ambergris have been written, but the question respecting it is still at issue. It is found in the stomachs of the most voracious fishes, these animals swallowing, at particular times, everything they happen to meet with. It has been particularly found in the intestines of the spermaceti whale, and most commonly in sickly fish, whence it is supposed to be the cause or effect of the disease. Some authors, and among them Robert Boyle, consider it to be of vegetable production, and analogous to amber; hence its name amber-_gris_ (gray) gray amber. It is not, however, within the province of this work to discuss upon the various theories about its production, which could probably be satisfactorily explained if our modern appliances were brought to bear upon the subject. The field is open to any scientific enthusiast; all recent authors who mention it, merely quoting the facts known more than a century ago. A modern compiler, speaking of ambergris, says, "It smells like dried cow-dung." Never having smelled this latter substance, we cannot say whether the simile be correct; but we certainly consider that its perfume is most incredibly overrated; nor can we forget that HOMBERG found that "a vessel in which he had made a long digestion of the human fæces had acquired a very strong and perfect smell of ambergris, insomuch that any one would have thought that a great quantity of essence of ambergris had been made in it. The perfume (_odor!_) was so strong that the vessel was obliged to be moved out of the laboratory." (Mem. Acad. Paris, 1711.) Nevertheless, as ambergris is extensively used as a perfume, in deference to those who admire its odor, we presume that it has to many an agreeable smell. Like bodies of this kind undergoing a slow decomposition and possessing little volatility, it, when mixed with other very fleeting scents, gives permanence to them on the handkerchief, and for this quality the perfumer esteems it much. ESSENCE OF AMBERGRIS Is only kept for mixing; when retailed it has to be sweetened up to the public nose; it is then called after the Parisian name EXTRAIT D'AMBRE. Esprit de rose triple, 1/2 pint. Extract of ambergris, 1 " Essence of musk, 1/4 " Extract of vanilla, 2 ounces. This perfume has such a lasting odor, that a handkerchief being well perfumed with it, will still retain an odor even after it has been washed. The fact is, that both musk and ambergris contain a substance which clings pertinaciously to woven fabrics, and not being soluble in weak alkaline lyes, is still found upon the material after passing through the lavatory ordeal. Powdered ambergris is used in the manufacture of cassolettes--little ivory or bone boxes perforated--which are made to contain a paste of strong-smelling substances, to carry in the pocket or reticule; also in the making of peau d'Espagne, or Spanish skin, used for perfuming writing paper and envelopes, and which will be described hereafter. [Illustration: Civet Cat.] CIVET.--This substance is secreted by the _Viverra civetta_, or civet cat. It is formed in a large double glandular receptacle between the anus and the pudendum of the creature. Like many other substances of Oriental origin, it was first brought to this country by the Dutch. When the civet cats are kept in a state of confinement, which at one time was common in Amsterdam, they are placed in strong cages, so constructed as to prevent the animal from turning round and biting the person employed in collecting the secreted substance. This operation is said to be performed twice a week, and is done by scraping out the civet with a small spoon: about a drachm at a time is thus obtained. A good deal of the civet now brought to European markets is from Calicut, capital of the province of Malabar, and from Bassora on the Euphrates. In its pure state, civet has, to nearly all persons, a most disgusting odor; but when diluted to an infinitesimal portion, its perfume is agreeable. It is difficult to ascertain the reason why the same substance, modified only by the quantity of matter presented to the nose, should produce an opposite effect on the olfactory nerve; but such is the case with nearly all odorous bodies, especially with ottos, which, if smelled at, are far from nice, and in some cases, positively nasty--such as otto of neroli, otto of thyme, otto of patchouly; but if diluted with a thousand times its volume of oil, spirit, &c., then their fragrance is delightful. Otto of rose to many has a sickly odor, but when eliminated in the homeopathic quantities as it rises from a single rose-bloom, who is it that will not admit that "the rose is sweet?" The odor of civet is best imparted, not by actual contact, but by being placed in the neighborhood of absorbent materials. Thus, when spread upon leather, which, being covered with silk and placed in a writing-desk, perfumes the paper and envelopes delightfully, and so much so, that they retain the odor after passing through the post. EXTRACT OF CIVET is prepared by rubbing in a mortar one ounce of civet with an ounce of orris-root powder, or any other similar material that will assist to break up or divide the civet; and then placing the whole into a gallon of rectified spirits; after macerating for a month, it is fit to strain off. It is principally used as a "fixing" ingredient, in mixing essences of delicate odor. The French perfumers use the extract of civet more than English manufacturers, who seem to prefer extract of musk. From a quarter of a pint to half a pint is the utmost that ought to be mixed with a gallon of any other perfume. CASTOR is a secretion of the _Castor fiber_, or beaver, very similar to civet. Though we have often heard of its being used in perfumery, we do not personally know that such is the case. MUSK.--This extraordinary substance, like civet, is an animal secretion; it is contained in excretory follicles about the navel of the male animal. In the perfumery trade these little bags are called "pods," and as imported it is called "pod musk." When the musk is separated from the skin or sack in which it is contained, it is then called "grain musk." The musk deer (_Moschus moschatus_) is an inhabitant of the great mountain range which belts the north of India, and branches out into Siberia, Thibet, and China. And it is also found in the Altaic range, near Lake Baikal, and in some other mountain ranges, but always on the borders of the line of perpetual snow. It is from the male animal only that the musk is produced. [Illustration: Musk Pod, actual size.] It formerly was held in high repute as a medicine, and is still so among Eastern nations. The musk from Boutan, Tonquin, and Thibet, is most esteemed, that from Bengal is inferior, and from Russia is of still lower quality. The strength and the quantity produced by a single animal varies with the season of the year and the age of the animal. A single musk pod usually contains from two to three drachms of grain musk. Musk is imported into England from China, in caddies of from 50 to 100 ounces each. When adulterated with the animal's blood, which is often the case, it forms into lumps or clots; it is sometimes also mixed with a dark, friable earth. Those pods in which little pieces of lead are discovered, as a general rule, yield the finest quality of musk; upon this rule, we presume that the best musk is the most worthy of adulteration. Musk is remarkable for the diffusiveness and subtlety of its scent; everything in its vicinity soon becomes affected by it, and long retains its odor, although not in actual contact with it. It is a fashion of the present day for people to say "that they do not like musk;" but, nevertheless, from great experience in one of the largest manufacturing perfumatories in Europe, we are of opinion that the public taste for musk is as great as any perfumer desires. Those substances containing it always take the preference in ready sale--so long as the vendor takes care to assure his customer "that there is no musk in it." [Illustration: The Musk Deer.] The perfumer uses musk principally in the scenting of soap, sachet powder, and in mixing for liquid perfumery. The just reputation of Paris's original Windsor soap is due, in the main, to its delightful odor. The soap is, doubtless, of the finest quality, but its perfume stamps it among the _élite_--its fragrance it owes to musk. The alkaline reaction of soap is favorable to the development of the odoriferous principle of musk. If, however, a strong solution of potass be poured on to grain musk, ammonia is developed instead of the true musk smell. EXTRACT OF MUSK. Grain musk, 2 oz. Rectified spirit, 1 gallon. After standing for one month, at a summer temperature, it is fit to draw off. Such an extract is that which is used for mixing in other perfumes. That extract of musk which is prepared for retail sale, is prepared thus:-- EXTRAIT DE MUSC. Extract of musk (as above), 1 pint. " ambergris, 1/2 " " rose triple, 1/4 " Mix and filter it; it is then fit for bottling. This preparation is sweeter than pure extract of musk made according to our first formula, and is also more profitable to the vendor. It will be seen hereafter that the original extract of musk is principally used for a fixing ingredient in other perfumes, to give permanence to a volatile odor; customers requiring, in a general way, that which is incompatible, namely, that a perfume shall be strong to smell, _i.e._ very volatile, and that it shall remain upon the handkerchief for a long period, _ergo_, not volatile! Small portions of extract of musk, mixed with esprit de rose, violet, tuberose, and others, do, in a measure, attain this object; that is, after the violet, &c., has evaporated, the handkerchief still retains an odor, which, although not that of the original smell, yet gives satisfaction, because it is pleasant to the nasal organ. SECTION V. AMMONIA.--Under the various titles of "Smelling Salts," "Preston Salts," "Inexhaustible Salts," "Eau de Luce," "Sal Volatile," ammonia, mixed with other odoriferous bodies, has been very extensively consumed as material for gratifying the olfactory nerve. The perfumer uses liq. amm. fortis, that is, strong liquid ammonia, and the sesqui-carbonate of ammonia, for preparing the various "salts" that he sells. These materials he does not attempt to make; in fact, it is quite out of his province so to do, but he procures them ready for his hand through some manufacturing chemist. The best preparation for smelling-bottles is what is termed INEXHAUSTIBLE SALTS, which is prepared thus:-- Liquid ammonia, 1 pint. Otto of rosemary, 1 drachm. " English lavender, 1 " " bergamot, 1/2 " " cloves, 1/2 " Mix the whole together with agitation in a very strong and well-stoppered bottle. This mixture is used by filling the smelling-bottles with any porous absorbent material, such as asbestos, or, what is better, sponge cuttings, that have been well beaten, washed, and dried. These cuttings can be procured at a nominal price from any of the sponge-dealers, being the trimming or roots of the Turkey sponge, which are cut off before the merchants send it into the retail market. After the bottles are filled with the sponge, it is thoroughly saturated with the scented ammonia, but no more is poured in than the sponge will retain, when the bottles are inverted; as, if by any chance the ammonia runs out and is spilt over certain colored fabrics, it causes a stain. When such an accident happens, the person who sold it is invariably blamed. When the sponge is saturated properly, it will retain the ammoniacal odor longer than any other material; hence, we presume, bottles filled in this way are called "inexhaustible," which name, however, they do not sustain more than two or three months with any credit; the warm hand soon dissipates the ammonia under any circumstances, and they require to be refilled. For transparent colored bottles, instead of sponge, the perfumers use what they call insoluble crystal salts (sulphate of potass). The bottles being filled with crystals, are covered either with the liquid ammonia, scented as above, or with alcoholic ammonia. The necks of the bottles are filled with a piece of white cotton; otherwise, when inverted, from the non-absorbent quality of the crystals, the ammonia runs out, and causes complaints to be made. The crystals are prettier in colored bottles than the sponge; but in plain bottles the sponge appears quite as handsome, and, as before observed, it holds the ammonia better than any other material. Perfumers sell also what is called WHITE SMELLING SALTS, and PRESTON SALTS. The White Smelling Salt is the sesqui-carbonate of ammonia in powder, with which is mixed any perfuming otto that is thought fit,--lavender otto giving, as a general rule, the most satisfaction. PRESTON SALTS, which is the cheapest of all the ammoniacal compounds, is composed of some easily decomposable salt of ammonia and lime, such as equal parts of muriate of ammonia, or of sesqui-carbonate of ammonia, and of fresh-slaked lime. When the bottles are filled with this compound, rammed in very hard, a drop or two of some cheap otto is poured on the top prior to corking. For this purpose otto of French lavender, or otto of bergamot, answers very well. We need scarcely mention that the corks are dipped into melted sealing-wax, or brushed over with liquid wax, that is, red or black wax dissolved in alcohol, to which a small portion of ether is added. The only other compound of ammonia that is sold in the perfumery trade is Eau de Luce, though properly it belongs to the druggist. When correctly made--which is very rarely the case--it retains the remarkable odor of oil of amber, which renders it characteristic. EAU DE LUCE. Tincture of benzoin: or, } " balsam of Peru, } 1 oz. Otto of lavender, 10 drops. Oil of amber, 5 " Liquor ammonia, 2 oz. If requisite, strain through cotton wool, but it must not be filtered, as it should have the appearance of a milk-white emulsion. ACETIC ACID AND ITS USE IN PERFUMERY.--The pungency of the odor of vinegar naturally brought it into the earliest use in the art of perfumery. The acetic acid, evolved by distilling acetate of copper (verdigris), is the true "aromatic" vinegar of the old alchemists. The modern aromatic vinegar is the concentrated acetic acid aromatized with various ottos, camphor, &c., thus-- AROMATIC VINEGAR. Concentrated acetic acid, 8 oz. Otto of English lavender, 2 drachms. " " rosemary, 1 drachm. " cloves, 1 " " camphor, 1 oz. First dissolve the bruised camphor in the acetic acid, then add the perfumes; after remaining together for a few days, with occasional agitation, it is to be strained, and is then ready for use. Several forms for the preparation of this substance have been published, almost all of which, however, appear to complicate and mystify a process that is all simplicity. The most popular article of this kind is-- HENRY'S VINEGAR. Dried leaves of rosemary, rue, wormwood, sage, mint, and lavender flowers, each, 1/2 oz. Bruised nutmeg, cloves, angelica root, and camphor, each, 1/4 oz. Alcohol (rectified), 4 oz. Concentrated acetic acid, 16 oz. Macerate the materials for a day in the spirit; then add the acid, and digest for a week longer, at a temperature of about 14° C. or 15° C. Finally, press out the new aromatized acid, and filter it. As this mixture must not go into the ordinary metallic tincture press, for the obvious reason of the chemical action that would ensue, it is best to drain as much of the liquor away as we can, by means of a common funnel, and then to save the residue from the interstices of the herbs, by tying them up in a linen cloth, and subjecting them to pressure by means of an ordinary lemon-squeezer, or similar device. VINAIGRE A LA ROSE. Concentrated acetic acid, 1 oz. Otto of roses, 1/2 drachm. Well shaken together. It is obvious that vinegars differently perfumed may be made in a similar manner to the above, by using other ottos in place of the otto of roses. All these concentrated vinegars are used in the same way as perfumed ammonia, that is, by pouring three or four drachms into an ornamental "smelling" bottle, previously filled with crystals of sulphate of potash, which forms the "sel de vinaigre" of the shops; or upon sponge into little silver boxes, called vinaigrettes, from their French origin. The use of these vinegars had their origin in the presumption of keeping those who carried them from the effects of infectious disease, doubtless springing out of the story of the "four thieves' vinegar," which is thus rendered in Lewis's Dispensatory: "It is said that during the plague at Marseilles, four persons, by the use of this preservative, attended, unhurt, multitudes of those that were affected; that under the color of these services, they robbed both the sick and the dead; and that being afterwards apprehended, one of them saved himself from the gallows by disclosing the composition of the prophylactic (a very likely story!!), which was as follows:-- VINAIGRE DES QUATRE VOLEURS, OR FOUR THIEVES' VINEGAR. Take fresh tops of common wormwood, Roman wormwood, rosemary, sage, mint, and rue, of each, 3/4 oz. Lavender flowers, 1 oz. Garlic, calamus aromaticus, cinnamon, cloves, and nutmeg, each, 1 drachm. Camphor, 1/2 oz. Alcohol or brandy, 1 oz. Strong vinegar, 4 pints. Digest all the materials, except the camphor and spirit, in a closely covered vessel for a fortnight, at a summer heat; then express and filter the vinaigre produced, and add the camphor previously dissolved in the brandy or spirit." A very similar and quite as effective a preparation may be made by dissolving the odorous principle of the plants indicated in a mixture of alcohol and acetic acid. Such preparations, however, are more within the province of the druggist than perfumer. There are, however, several preparations of vinegar which are sold to some extent for mixing with the water for lavatory purposes and the bath, their vendors endeavoring to place them in competition with Eau de Cologne, but with little avail. Among them may be enumerated-- HYGIENIC OR PREVENTIVE VINEGAR. Brandy, 1 pint. Otto of cloves, 1 drachm. " lavender, 1 " " marjoram, 1/2 drachm. Gum benzoin, 1 oz. Macerate these together for a few hours, then add-- Brown vinegar, 2 pints. and strain or filter, if requisite, to be bright. TOILET VINEGAR (_à la Violette_). Extract of cassie, 1/2 pint. " orris, 1/4 " Esprit de rose, triple, 1/4 " White wine vinegar, 2 pints. TOILET VINEGAR (_à la Rose_). Dried rose-leaves, 4 oz. Esprit de rose, triple, 1/2 pint. White wine vinegar, 2 pints. Macerate in a close vessel for a fortnight, then filter and bottle for sale. VINAIGRE DE COLOGNE. To eau de Cologne, 1 pint, Add, strong acetic acid, 1/2 oz. Filter if necessary. Without unnecessarily repeating similar formulæ, it will be obvious to the reader that vinegar of any flower may be prepared in a similar way to those above noticed; thus, for vinaigre à la jasmine, or for vinaigre à la fleur d'orange, we have only to substitute the esprit de jasmine, or the esprit de fleur d'orange, in place of the Eau de Cologne, to produce orange-flower or jasmine vinegars; however, these latter articles are not in demand, and our only reason for explaining how such preparations may be made, is in order to suggest the methods of procedure to any one desirous of making them leading articles in their trade. We perhaps may observe, _en passant_, that where economy in the production of any of the toilet vinegars is a matter of consideration, they have only to be diluted with rose-water down to the profitable strength required. Any of the perfumed vinegars that are required to produce opalescence, when mixed with water, must contain some gum-resin, like the hygienic vinegar, as above. Either myrrh, benzoin, storax, or tolu, answer equally well. SECTION VI. BOUQUETS AND NOSEGAYS. In the previous articles we have endeavored to explain the mode of preparing the primitive perfumes--the original odors of plants. It will have been observed, that while the majority can be obtained under the form of otto or essential oil, there are others which hitherto have not been isolated, but exist only in solution in alcohol, or in a fatty body. Of the latter are included all that are most prized, with the exception of otto of rose--that diamond among the odoriferous gems. Practically, we have no essential oils or ottos of Jasmine, Vanilla, Acacia, Tuberose, Cassie, Syringa, Violets, and others. What we know of these odors is derived from esprits, obtained from oils or fats, in which the several flowers have been repeatedly infused, and afterwards infusing such fats or oils in alcohol. Undoubtedly, these odors are the most generally pleasing, while those made from the essential oils (_i.e._ otto), dissolved in spirit, are of a secondary character. The simple odors, when isolated, are called ESSENTIAL OILS or OTTOS; when dissolved or existing in solution in alcohol, by the English they are termed ESSENCES, and by the French EXTRAITS or ESPRITS; a few exceptions prove this rule. Essential oil of orange-peel, and of lemon-peel, are frequently termed in the trade "Essence" of orange and "Essence" of lemons, instead of essential oil or otto of lemons, &c. The sooner the correct nomenclature is used in perfumery, as well as in the allied arts, the better, and the fewer blunders will be made in the dispensatory. It appears to the writer, that if the nomenclature of these substances were revised, it would be serviceable; and he would suggest that, as a significant, brief, and comprehensive term, Otto be used as a prefix to denote that such and such a body is the odoriferous principle of the plant. We should then have otto of lavender instead of essential oil of lavender, &c. &c. In this work it will be seen that the writer has generally used the word OTTO in place of "essential oil," in accordance with his views. Where there exists a solution of an essential oil in a fat oil, the necessity of some such significant distinction is rendered obvious, for commercially such articles are still called "oils"--oil of jasmine, oil of roses, &c. It cannot be expected that the public will use the words "fat" oil and "essential" oil, to distinguish these differences of composition. There are several good reasons why the odoriferous principle of plants should not be denominated oils. In the first place, it is a bad principle to give any class of substances the same signification as those belonging to another. Surely, there are enough distinguishing qualities in their composition, their physical character, and chemical reaction, to warrant the application of a significant name to that large class of substances known as the aroma of plants! When the chemical nomenclature was last revised, the organic bodies were little dealt with. We know that we owe this universal "oil" to the old alchemist, much in the same way as "spirit" has been used, but a little consideration quickly indicates the folly of its continued use. We can no longer call otto of rosemary, or otto of nutmegs, essential oil of rosemary or nutmegs, with any more propriety than we can term sulphuric acid "oil" of vitriol. All the chemical works speak of the odoriferous bodies as "essential" or "volatile" oils, and of the greasy bodies as "fat" or "unctuous" oils. Oils, properly so called, unite with salifiable bases and form soap; whereas the essential or volatile oils, _i.e._ what we would please to call the ottos, do no such thing. On the contrary, they unite with acids in the majority of instances. The word oil must hereafter be confined to those bodies to which its literal meaning refers--fat, unctuous, inodorous (when pure), greasy substances--and can no longer be applied to those odoriferous materials which possess qualities diametrically opposite to oil. We have grappled with "spirit," and fixed its meaning in a chemical sense; we have no longer "spirit" of salt, or "spirit" of hartshorn. Let us no longer have almond oil "essential," almond oil "unctuous," and the like. It remains only for us to complete the branch of perfumery which relates to odors for the handkerchief, by giving the formulæ for preparing the most favorite "bouquets" and "nosegays." These, as before stated, are but mixtures of the simple ottos in spirit, which, properly blended, produce an agreeable and characteristic odor,--an effect upon the smelling nerve similar to that which music or the mixture of harmonious sounds produces upon the nerve of hearing, that of pleasure. THE ALHAMBRA PERFUME. Extract of tubereuse, 1 pint. " geranium, 1/2 " " acacia, 1/4 " " fleur d'orange, 1/4 " " civet, 1/4 " THE BOSPHORUS BOUQUET. Extract of acacia, 1 pint. " jasmine, } " rose triple, } of each, 1/2 " " fleur d'orange, } " tubereuse, } " civet, 1/4 " Otto of almonds, 10 drops. BOUQUET D'AMOUR. Esprit de rose, } " jasmine, } from pomade, of each, 1 pint. " violette, } " cassie, } Extract of musk, } of each, 1/2 " " ambergris, } Mix and filter. BOUQUET DES FLEURS DU VAL D'ANDORRE. Extrait de jasmine, } " rose, } from pomade, of each, 1 pint. " violette, } " tuberose, } Extract of orris, 1 " Otto of geranium, 1/4 oz. BUCKINGHAM PALACE BOUQUET. Extrait de fleur d'orange,} " cassie, } from pomade, of each, 1 pint. " jasmine, } " rose, } Extract of orris, } of each, 1/2 " " ambergris, } Otto of neroli, 1/2 drachm. " lavender, 1/2 " " rose, 1 " BOUQUET DE CAROLINE; ALSO CALLED BOUQUET DES DELICES. Extrait de rose, } " violette, } from pomade, of each, 1 pint. " tuberose, } Extract of orris, } of each, 1/2 " " ambergris, } Otto of bergamot, } " Limette, } of each, 1/4 oz. " cedret, } THE COURT NOSEGAY. Extrait de rose, } " violette, } of each, 1 pint. " jasmine, } Esprit de rose triple, 1 " Extract of musk, } of each, 1 oz. " ambergris, } Otto of lemon, } of each, 1/2 oz. " bergamot, } " neroli, 1 drachm. EAU DE CHYPRE. This is an old-fashioned French perfume, presumed to be derived from the _Cyperus esculentus_ by some, and by others to be so named after the Island of Cyprus; the article sold, however, is made thus-- Extract of musk, 1 pint. " ambergris, } " vanilla, } of each, 1/2 " " tonquin bean, } " orris, } Esprit de rose triple, 2 pints. The mixture thus formed is one of the most lasting odors that can be made. EMPRESS EUGENIE'S NOSEGAY. Extract of musk, } " vanilla, } of each, 1/4 pint. " tonquin, } " neroli, } " geranium, } " rose triple, } of each, 1/2 " " santal, } ESTERHAZY BOUQUET. Extrait de fleur d'orange (from pomade), 1 pint. Esprit de rose triple, 1 " Extract of vitivert, } " vanilla, } of each, 2 " " orris, } " tonquin, } Esprit de neroli, 1 " Extract of ambergris, 1/2 " Otto of santal, 1/2 drachm. " cloves, 1/2 " Notwithstanding the complex mixture here given, it is the vitivert that gives this bouquet its peculiar character. Few perfumes have excited greater _furor_ while in fashion. ESS BOUQUET. The reputation of this perfume has given rise to numerous imitations of the original article, more particularly on the continent. In many of the shops in Germany and in France will be seen bottles labelled in close imitation of those sent out by Bayley and Co., Cockspur Street, London, who are, in truth, the original makers. Esprit de rose triple, 1 pint. Extract of ambergris, 2 oz. " orris, 8 " Otto of lemons, 1/4 " " bergamot, 1 " The name "Ess" bouquet, which appears to puzzle some folk, is but a mere contraction of "essence" of bouquet. EAU DE COLOGNE. (_La première qualité._) Spirit (from grape), 60 over proof, 6 gallons. Otto of neroli, _Petale_, 3 oz. " " _Bigarade_, 1 " " rosemary, 2 " " orange-peel, 5 " " citron-peel, 5 " " bergamot-peel, 2 " Mix with agitation; then allow it to stand for a few days perfectly quiet, before bottling. EAU DE COLOGNE. (_La deuxième qualité._) Spirit (from corn), 6 gallons. Otto of neroli, _Petit-grain_, 2 oz. " " _Petale_, 1/2 " " rosemary, 2 " " orange-peel, } " lemon, } of each, 4 " " bergamot, } Although Eau de Cologne was originally introduced to the public as a sort of "cure-all," a regular "elixir of life," it now takes its place, not as a pharmaceutical product, but among perfumery. Of its remedial qualities we can say nothing, such matter being irrelevant to the purpose of this book. Considered, however, as a perfume, with the public taste it ranks very high; and although it is exceedingly volatile and evanescent, yet it has that excellent quality which is called "refreshing." Whether this be due to the rosemary or to the spirit, we cannot say, but think something may be attributed to both. One important thing relating to Eau de Cologne must not, however, pass unnoticed, and that is, the quality of the spirit used in its manufacture. The utter impossibility of making brandy with English spirit in any way to resemble the real Cognac, is well known. It is equally impossible to make Eau de Cologne with English spirit, to resemble the original article. To speak of the "purity" of French spirit, or of the "impurity" of English spirit, is equally absurd. The fact is, that spirit derived from grapes, and spirit obtained from corn, have each so distinct and characteristic an aroma, that the one cannot be mistaken for the other. The odor of grape spirit is said to be due to the oeanthic ether which it contains. The English spirit, on the other hand, owes its odor to fusel oil. So powerful is the oeanthic ether in the French spirit, that notwithstanding the addition to it of such intensely odoriferous substances as the ottos of neroli, rosemary, and others, it still gives a characteristic perfume to the products made containing it, and hence the difficulty of preparing Eau de Cologne with any spirit destitute of this substance. Although very fine Eau de Cologne is often made by merely mixing the ingredients as indicated in the recipe as above, yet it is better, first, to mix all the citrine ottos with spirit, and then to distil the mixture, afterwards adding to the distillate the rosemary and nerolies, such process being the one adopted by the most popular house at Cologne. A great many forms for the manufacture of Eau de Cologne have been published, the authors of some of the recipes evidently having no knowledge, in a practical sense, of what they were putting by theory on paper; other venturers, to show their lore, have searched out all the aromatics of Lindley's Botany, and would persuade us to use absinthe, hyssop, anise, juniper, marjoram, caraway, fennel, cumin, cardamom, cinnamon, nutmeg, serpolet, angelica, cloves, lavender, camphor, balm, peppermint, galanga, lemon thyme, &c. &c. &c. All these, however, are but hum--! Where it is a mere matter of profit, and the formula that we have given is too expensive to produce the article required, it is better to dilute the said Cologne with a weak spirit, or with rose-water, rather than otherwise alter its form; because, although weak, the true aroma of the original article is retained. The recipe of the second quality of Eau de Cologne is given, to show that a very decent article can be produced with English spirit. FLOWERS OF ERIN. Extract of white rose (see WHITE ROSE), 1 pint. " vanilla, 1 oz. ROYAL HUNT BOUQUET. Esprit de rose triple, 1 pint. " neroli, } " acacia, } " fleur d'orange, } of each 1/4 " " musk, } " orris, } " tonquin, 1/2 " Otto of citron 2 drachms. BOUQUET DE FLORA; OTHERWISE, EXTRACT OF FLOWERS. Esprit de rose,} " tubereuse, } from pomade, of each, 1 pint. " violette, } Extract of benzoin, 1-1/2 oz. Otto of bergamot, 2 " " lemon, } " orange, } of each, 1/2 " THE GUARDS' BOUQUET. Esprit de rose, 2 pints. " neroli, 1/2 pint. Extract of vanilla, 2 oz. " orris, 2 " " musk, 1/4 pint. Otto of cloves, 1/2 drachm. FLEUR D'ITALIE; OR ITALIAN NOSEGAY. Esprit de rose, from pomade, 2 pints. " rose triple, 1 pint. " jasmine, } " violette, } from pomade, each, 1 " Extract of cassie, 1/2 " " musk, } " ambergris, } of each, 2 oz. JOCKEY CLUB BOUQUET. (_English formula._) Extract of orris root, 2 pints. Esprit de rose, triple, 1 pint. " rose de pomade, 1 " Extrait de cassie, } " tubereuse, } de pomade, of each 1/2 " " ambergris, } 1/2 " Otto of bergamot, 1/2 oz. JOCKEY CLUB BOUQUET. (_French formula._) Esprit de rose, de pomade, 1 pint. " tubereuse, 1 " " cassie, 1/2 " " jasmine, 1/4 " Extract of civet, 3 oz. Independently of the materials employed being different to the original English recipe, it must be remembered that all the French perfumes are made of brandy, _i.e._ grape spirit; whereas the English perfumes are made with corn spirit, which alone modifies their odor. Though good for some mixtures, yet for others the grape spirit is very objectionable, on account of the predominance of its own aroma. We have spoken of the difference in the odor between the English and French spirit; the marked distinction of British and Parisian perfumes made according to the same recipes is entirely due to the different spirits employed. Owing to the strong "bouquet," as the French say, of their spirit in comparison with ours, the continental perfumers claim a superiority in the quality of their perfumes. Now, although we candidly admit that _some_ odors are better when prepared with grape spirit than with that from corn spirit, yet there are others which are undoubtedly the best when prepared with spirit derived from the latter source. Musk, ambergris, civet, violet, tubereuse, and jasmine, if we require to retain their true aroma when in solution in alcohol, must be made with the British spirit. All the citrine odors, verveine, vulnerary waters, Eau de Cologne, Eau de Portugal, Eau d'Arquebuzade, and lavender, can alone be brought to perfection by using the French spirit in their manufacture. If extract of jasmine, or extract of violet, &c., be made with the French or brandy spirit, the true characteristic odor of the flower is lost to the olfactory nerve--so completely does the oeanthic ether of the grape spirit hide the flowery aroma of the otto of violet in solution with it. This solves the paradox that English extract of violet and its compounds, "spring flowers," &c., is at all times in demand on the Continent, although the very flowers with which we make it are grown there. On the contrary, if an English perfumer attempts to make Eau de Portugal, &c., to bear any comparison as a fine odor to that made by Lubin, of Paris, without using grape spirit, his attempts will prove a failure. True, he makes Eau de Portugal even with English corn spirit, but judges of the article--and they alone can stamp its merit--discover instantly the same difference as the connoisseur finds out between "Patent British" and foreign brandy. Perhaps it may not be out of place here to observe that what is sold in this country as British brandy is in truth grape spirit, that is, foreign brandy very largely diluted with English spirit! By this scheme, a real semblance to the foreign brandy flavor is maintained; the difference in duty upon English and foreign spirit enables the makers of the "capsuled" article to undersell those who vend the unsophisticated Cognac. Some chemists, not being very deep in the "tricks of trade," have thought that some flavoring, or that oeanthic ether, was used to impart to British spirit the Cognac aroma. An article is even in the market called "Essence of Cognac," but which is nothing more than very badly made butyric ether. On the Continent a great deal of spirit is procured by the fermentation of the molasses from beet-root; this, of course, finds its way into the market, and is often mixed with the grape spirit; so, also, in England we have spirit from potatoes, which is mixed in the corn spirit. These adulterations, if we may so term it, modify the relative odors of the primitive alcohols. A JAPANESE PERFUME. Extract of rose triple, } " vitivert, } " patchouly, } of each, 1/2 pint. " cedar, } " santal, } " vervaine, 1/4 " KEW GARDEN NOSEGAY. Esprit de neroli (_Petale_), 1 pint. " cassie, } " tubereuse, } from pomade, of each, 1/2 " " jasmine, } " geranium, 1/2 " " musk, } of each, 3 oz. " ambergris, } EAU DES MILLEFLEURS. Esprit de rose triple, 1 pint. " rose de pomade,} " tubereuse, } " jasmine, } from pomade, of each, 1/2 " " fleur d'orange,} " cassie, } " violette, } Extract of cedar, 1/4 " Extract of vanilla, } " ambergris, } of each, 2 oz. " musk, } Otto of almonds, } " neroli, } of each, 10 drops. " cloves, } " bergamot, 1 oz. These ingredients are to remain together for at least a fortnight, then filtered prior to sale. MILLEFLEURS ET LAVENDER. Essence of lavender (_Mitcham_), 1/2 pint. Eau des millefleurs, 1 " DECROIX'S MILLEFLOWER LAVENDER. Spirits from grape, 1 pint. French otto of lavender, 1 oz. Extract of ambergris, 2 oz. The original "lavender aux millefleurs" is that of Delcroix; its peculiar odor is due to the French otto of lavender, which, although some folks like it, is very inferior to the English otto of lavender; hence the formula first given is far superior to that by the inventor, and has almost superseded the original preparations. There are several other compounds or bouquets of which lavender is the leading ingredient, and from which they take their name, such as lavender and ambergris, lavender and musk, lavender and maréchale, &c., all of which are composed of fine spirituous essences of lavender, with about 15 per cent. of any of the other ingredients. BOUQUET DU MARECHALE. Esprit de rose triple, } } of each, 1 pint. Extrait de fleur d'orange, } " vitivert, } " vanilla, } " orris, } of each, 1/2 " " tonquin, } Esprit de neroli, } Extract of musk, } of each, 1/4 pint. " ambergris, } Otto of cloves, } of each, 1/2 drachm. " santal, } EAU DE MOUSSELAINE. Bouquet maréchale, 1 pint. Extrait de cassie, } " jasmine, } from pomade, of each, 1/2 " " tubereuse,} " rose, } Otto of santal, 2 drachms. BOUQUET DE MONTPELLIER. Extrait de tubereuse, 1 pint. " rose de pomade, 1 " " rose triple, 1 " Extract of musk, } of each, 1/4 " " ambergris, } Otto of cloves, 1-1/2 drachm. " bergarmot, 1/2 oz. CAPRICE DE LA MODE. Extrait de jasmine, } " tubereuse, } of each, 1/2 pint. " cassie, } " fleur d'orange, } Otto of almonds, 10 drops. " nutmegs, 10 " Extract of civet, 1/4 pint. MAY FLOWERS. Extract of rose (de pomade), } " jasmine, } of each, 1/2 pint. " fleur d'orange, } " cassie, } " vanilla, 1 " Otto of almonds, 1/4 drachm. NEPTUNE, OR NAVAL NOSEGAY. Extrait de rose, triple, } " santal, } of each, 1/2 pint. " vitivert, } " patchouly, } " verbena, 1/8 " BOUQUET OF ALL NATIONS. Countries wherein the Odors are produced. TURKEY, Esprit de rose triple, 1/2 pint. AFRICA, Extract of jasmine, 1/2 " ENGLAND, " lavender, 1/4 " FRANCE, " tubereuse, 1/2 " SOUTH AMERICA, " vanilla, 1/4 " TIMOR, " santal, 1/4 " ITALY, " violet, 1 " HINDOOSTAN, " patchouly, 1/4 " CEYLON, Otto of citronella, 1 drachm. SARDINIA, " lemons, 1/4 oz. TONQUIN, Extract of musk, 1/4 pint. ISLE OF WIGHT BOUQUET. Extract of orris, 1/2 pint. " vitivert, 1/4 " " santal, 1 " " rose, 1/2 " BOUQUET DU ROI. Extract of jasmine, } " violet, } from pomade, of each, 1 pint. " rose } " vanilla, } of each, 1/4 pint. " vitivert, } " musk, } of each, 1 oz. " ambergris, } Otto of bergamot, 1 oz. " cloves, 1 drachm. BOUQUET DE LA REINE. Esprit de rose, } from pomade, of each, 1 pint. Extrait de violette, } " tubereuse, 1/2 " " fleur d'orange, 1/4 " Otto of bergamot, 1/4 oz. RONDELETIA. The perfume bearing the above name is undoubtedly one of the most gratifying to the smelling nerve that has ever been made. Its inventors, Messrs. Hannay and Dietrichsen, have probably taken the _name_ of this odor from the _Rondeletia_, the _Chyn-len_ of the Chinese; or from the R. odorata of the West Indies, which has a sweet odor. We have before observed that there is a similarity of effect upon the olfactory nerve produced by certain odors, although derived from totally different sources: that, for instance, otto of almonds may be mixed with extract of violet in such proportion that, although the odor is increased, yet the character peculiar to the violet is not destroyed. Again: there are certain odors which, on being mixed in due proportion, produce a new aroma, perfectly distinct and peculiar to itself. This effect is exemplified by comparison with the influence of certain colors when mixed, upon the nerve of vision: such, for instance, as when yellow and blue are mixed, the result we call green; or when blue and red are united, the compound color is known as puce or violet. Now when the odor of lavender and odor of cloves are mixed, they produce a new fragrance, _i.e._ Rondeletia! It is such combinations that constitute in reality "a new perfume," which, though often advertised, is very rarely attained. Jasmine and patchouly produce a novel aroma, and many others in like manner; proportion and relative strength, when so mixed, must of course be studied, and the substances used accordingly. If the same quantity of any given otto be dissolved in a like proportion of spirit, and the solution be mixed in equal proportions, the strongest odor is instantly indicated by covering or hiding the presence of the other. In this way we discover that patchouly, lavender, neroli, and verbena are the most potent of the vegetable odors, and that violet, tubereuse, and jasmine are the most delicate. Many persons will at first consider that we are asking too much, when we express a desire to have the same deference paid to the olfactory nerve, as to the other nerves that influence our physical pleasures and pains. By tutoring the olfactory nerve, it is capable of perceiving matter in the atmosphere of the most subtle nature: not only that which is pleasant, but also such as are unhealthful. If an unpleasant odor is a warning to seek a purer atmosphere, surely it is worth while to cultivate that power which enables us to act up to that warning for the general benefit of health. To return, however, to Rondeletia: it will be seen by the annexed formulæ, that, besides the main ingredients to which it owes its peculiar character--that is, cloves and lavender--it contains musk, vanilla, &c. These substances are used in these as in nearly all other bouquets for the sole purpose of fixing the more volatile odors to the handkerchief. ESSENCE OF RONDELETIA. Spirit (brandy 60 o.p.), 1 gallon. Otto of lavender, 2 oz. " cloves, 1 oz. " roses, 3 drachms. " bergamot, 1 oz. Extract of musk, } " vanilla, } each, 1/4 pint. " ambergris, } The mixture must be made at least a month before it is fit for sale. Very excellent Rondeletia may also be made with English spirit. BOUQUET ROYAL. Extract of rose (from pomade), 1 pint. Esprit de rose, triple, 1/2 " Extract of jasmine, } from pomade, each, 1/2 " " violet, } " verbena, } each, 2-1/2 oz. " cassie, } Otto of lemons, } each, 1/4 oz. " bergamot, } Extract of musk, } each, 1 oz. " ambergris, } SUAVE. Extract of tubereuse, } " jasmine, } from pomade, each, 1 pint. " cassie, } " rose, } " vanilla, 5 oz. " musk, } each, 2 oz. " ambergris, } Otto of bergamot, 1/4 oz. " cloves, 1 drachm. SPRING FLOWERS. Extract of rose, } from pomade, each, 1 pint. " violet, } " rose, triple, 2-1/2 oz. " cassie, 2-1/2 oz. Otto of bergamot, 2 drachms. Extract of ambergris, 1 oz. The just reputation of this perfume places it in the first rank of the very best mixtures that have ever been made by any manufacturing perfumer. Its odor is truly flowery, but peculiar to itself. Being unlike any other aroma it cannot well be imitated, chiefly because there is nothing that we are acquainted with that at all resembles the odor of the esprit de rose, as derived from macerating rose pomade in spirit, to which, and to the extract of violet, nicely counterpoised, so that neither odor predominates, the peculiar character of "Spring Flowers" is due; the little ambergris that is present gives permanence to the odor upon the handkerchief, although from the very nature of the ingredients it may be said to be a fleeting odor. "Spring Flowers" is an Englishman's invention, but there is scarcely a perfumer in Europe that does not attempt an imitation. TULIP NOSEGAY. Nearly all the tulip tribe, although beautiful to the eye, are inodorous. The variety called the Duc Van Thol, however, yields an exquisite perfume, but it is not used by the manufacturer for the purpose of extracting its odor. He, however, borrows its poetical name, and makes an excellent imitation thus:-- Extract of tubereuse, } from pomade each, 1 pint. " violet, } " rose, 1/2 " " orris, 3 oz. Otto of almonds, 3 drops. VIOLETTE DES BOIS. Under the head Violet, we have already explained the method of preparing the extract or essence of that modest flower. The Parisian perfumers sell a mixture of violet, which is very beautiful, under the title of the Violet des Bois, or the Wood Violet, which is made thus:-- Extract of violet, 1 pint. " orris, 3 oz. " cassie, 3 oz. " rose (from pomade) 3 oz. Otto of almonds, 3 drops. This mixture, in a general way, gives more satisfaction to the customer than the pure violet. WINDSOR CASTLE BOUQUET. Alcohol, 1 pint. Otto of neroli, } " rose, } each, 1/4 oz. " lavender, } " bergamot, } " cloves, 8 drops. Extract of orris, 1 pint. " jasmine, } each, 1/4 " " cassie, } " musk, } each, 2-1/2 oz. " ambergris, } YACHT CLUB BOUQUET. Extract of santal, 1 pint. " neroli, 1 " " jasmine, } each, 1/2 " " rose triple, } " vanilla, 1/4 " Flowers of benzoin, 1/4 oz. We have now completed the branch of the Art of Perfumery which relates to handkerchief perfumes, or wet perfumery. Although we have rather too much encroached upon the space of this work in giving the composition of so many bouquets, yet there are many left unnoticed which are popular. Those that are given are noted more particularly for the peculiar character of their odor, and are selected from more than a thousand recipes that have been practically tried. Those readers who require to know anything about the simple extracts of flowers are referred to them under their respective alphabetical titles. SECTION VII. The previous articles have exclusively treated of Wet Perfumes; the present matter relates, to Dry Perfumes,--sachet powders, tablets, pastilles, fumigation by the aid of heat of volatile odorous resins, &c. &c. The perfumes used by the ancients were, undoubtedly, nothing more than the odoriferous gums which naturally exude from various trees and shrubs indigenous to the Eastern hemisphere: that they were very extensively used and much valued, we have only to read the Scriptures for proofs:--"Who is this that cometh ... perfumed with myrrh and frankincense, with all the powders of the merchant?" (Song of Solomon, 3:6.) Abstaining from the use of perfume in Eastern countries is considered as a sign of humiliation:--"The Lord will take away the tablets, and it shall come to pass that instead of a sweet smell there shall be a stink." (Exod. 35:22; Isaiah 3:20, 24.) The word tablets in this passage means perfume boxes, curiously inlaid, made of metal, wood, and ivory. Some of these boxes may have been made in the shape of buildings, which would explain the word _palaces_, in Psalm 14:8:--"All thy garments smell of myrrh, and aloes, and cassia, out of the ivory palaces, whereby they have made thee glad." From what is said in Matt. 2:11, it would appear that perfumes were considered among the most valuable gifts which man could bestow;--"And when they (the wise men) had opened their treasures, they presented unto him (Christ) gifts; gold, and frankincense, and myrrh." As far as we are able to learn, all the perfumes used by the Egyptians and Persians during the early period of the world were _dry_ perfumes, consisting of spikenard (_Nardostachys jatamansi_), myrrh, olibanum, and other gum-resins, nearly all of which are still in use by the manufacturers of odors. Among the curiosities shown at Alnwick Castle is a vase that was taken from an Egyptian catacomb. It is full of a mixture of gum-resin, &c., which evolve a pleasant odor to the present day, although probably 3000 years old. We have no doubt that the original use of this vase and its contents were for perfuming apartments, in the same way that pot pourri is now used. SACHET POWDERS. The French and English perfumers concoct a great variety of these substances, which being put into silk bags, or ornamental envelopes, find a ready sale, being both good to smell and economical as a means of imparting an agreeable odor to linen and clothes as they lie in drawers. The following formula shows their composition. Every material is either to be ground in a mill, or powdered in a mortar, and afterwards sifted. SACHET AU CYPRE. Ground rose-wood, 1 lb. " cedar-wood, 1 lb. " santal-wood, 1 lb. Otto of rhodium, or otto of rose, 3 drachms. Mix and sift; it is then fit for sale. SACHET A LA FRANGIPANNE. Orris-root powder, 3 lbs. Vitivert powder, 1/4 lb. Santal-wood powder, 1/4 lb. Otto of neroli, } " rose, } of each, 1 drachm. " santal, } Musk-pods, ground, 1 oz. The name of this sachet has been handed down to us as being derived from a Roman of the noble family of Frangipani. Mutio Frangipani was an alchemist, evidently of some repute, as we have another article called rosolis, or ros-solis, _sun-dew_, an aromatic spirituous liquor, used as a stomachic, of which he is said to be the inventor, composed of wine, in which is steeped coriander, fennel, anise, and musk. HELIOTROPE SACHET. Powdered orris, 2 lbs. Rose leaves, ground, 1 lb. Tonquin beans, ground, 1/2 lb. Vanilla beans, 1/4 lb. Grain musk, 1/4 oz. Otto of almonds, 5 drops. Well mixed by sifting in a coarse sieve, it is fit for sale. It is one of the best sachets made, and is so perfectly _au naturel_ in its odor to the flower from which it derives its name, that no person unacquainted with its composition would, for an instant, believe it to be any other than the "real thing." LAVENDER SACHET. Lavender flowers, ground, 1 lb. Gum benzoin, in powder, 1/4 lb. Otto of lavender, 1/4 oz. SACHET A LA MARECHALE. Powder of santal-wood, 1/2 lb. " orris-root, 1/2 lb. Rose-leaves, ground, 1/4 lb. Cloves, ground, 1/4 lb. Cassia-bark, 1/4 lb. Grain musk, 1/2 drachm. SACHET A LA MOUSSELAINE. Vitivert, in powder, 1 lb. Santal-wood, } Orris, } each, 1/2 lb. Black-currant leaves (_casse_), 1/2 lb. Benzoin, in powder, 1/4 lb. Otto of thyme, 5 drops. " roses, 1/2 drachm. MILLEFLEUR SACHET. Lavender-flowers, ground, } Orris, } each, 1 lb. Rose-leaves, } Benzoin, } Tonquin, } Vanilla, } each, 1/4 lb. Santal, } Musk and civet, 2 drachms. Cloves, ground, 1/4 lb. Cinnamon, } each, 2 oz. Allspice, } PORTUGAL SACHET. Dried orange-peel, 1 lb. " lemon-peel, 1/2 lb. " orris-root, 1/2 lb. Otto of orange-peel, 1 oz. " neroli, 1/4 drachm. " lemon-grass, 1/4 " PATCHOULY SACHET. Patchouly herb, ground, 1 lb. Otto of patchouly, 1/4 drachm. Patchouly herb is often sold in its natural state, as imported, tied up in bundles of half a pound each. POT POURRI. This is a mixture of dried flowers and spices _not_ ground. Dried lavender, 1 lb. Whole rose-leaves, 1 lb. Crushed orris (coarse), 1/2 lb. Broken cloves, } " cinnamon, } each, 2 oz. " allspice, } Table salt, 1 lb. We need scarcely observe that the salt is only used to increase the bulk and weight of the product, in order to sell it cheap. OLLA PODRIDA. This is a similar preparation to pot pourri. No regular form can be given for it, as it is generally made, or "knocked up," with the refuse and spent materials derived from other processes in the manufacture of perfumery; such as the spent vanilla after the manufacture of tincture or extract of vanilla, or of the grain musk from the extract of musk, orris from the tincture, tonquin beans, after tincturation, &c. &c., mixed up with rose-leaves, lavender, or any odoriferous herbs. ROSE SACHET. Rose heels or leaves, 1 lb. Santal-wood, ground, 1/2 lb. Otto of roses, 1/4 oz. SANTAL-WOOD SACHET. This is a good and economical sachet, and simply consists of the ground wood. Santal-wood is to be purchased from some of the wholesale drysalters; the drug-grinders are the people to reduce it to powder for you--any attempt to do so at home will be found unavailable, on account of its toughness. SACHET (_without a name_). Dried thyme, } " lemon thyme, } of each, 1/4 lb. " mint, } " marjoram, } " lavender, 1/2 lb. " rose heels, 1 lb. Ground cloves, 2 oz. Allspice, 2 oz. Musk in grain, 1 drachm. VERVAIN SACHET. Lemon-peel, dried and ground, 1 lb. " thyme, 1/4 lb. Otto of lemon-grass, 1 drachm. " " peel, 1/2 oz. " bergamot, 1 oz. VITIVERT SACHET. The fibrous roots of the _Anthoxanthum muricatum_ being ground, constitute the sachet, bearing the name as above, derived from the Tamool name, _vittie vayer_, and by the Parisian _vetiver_. Its odor resembles myrrh. Vitivert is more often sold tied up in bunches, as imported from India, than ground, and is used for the prevention of moth, rather than as a perfume. VIOLET SACHET. Black-currant leaves (_casse_), 1 lb. Rose heels or leaves, 1 lb. Orris-root powder, 2 lbs. Otto of almonds, 1/4 drachm. Grain musk, 1 " Gum benzoin, in powder, 1/2 lb. Well mix the ingredients by sifting; keep them together for a week in a glass or porcelain jar before offering for sale. There are many other sachets manufactured besides those already given, but for actual trade purposes there is no advantage in keeping a greater variety than those named. There are, however, many other substances used in a similar way; the most popular is the PEAU D'ESPAGNE. Peau d'Espagne, or Spanish skin, is nothing more than highly perfumed leather. Good sound pieces of wash leather are to be steeped in a mixture of ottos, in which are dissolved some odoriferous gum-resins, thus:--Otto of neroli, otto of rose, santal, of each half an ounce; otto of lavender, verbena, bergamot, of each a quarter of an ounce; otto of cloves and cinnamon, of each two drachms; with any others thought fit. In this mixture dissolve about two ounces of gum benzoin; now place the skin to steep in it for a day or so, then hang it over a line to dry. A paste is now to be made by rubbing in a mortar one drachm of civet with one drachm of grain musk, and enough solution of gum acacia or gum tragacantha to give it a spreading consistence; a little of any of the ottos that may be left from the steep stirred in with the civet, &c., greatly assists in making the whole of an equal body; the skin being cut up into pieces of about four inches square are then to be spread over, plaster fashion, with the last-named compost; two pieces being put together, having the civet plaster inside them, are then to be placed between sheets of paper, weighed or pressed, and left to dry thus for a week; finally, each double skin, now called peau d'Espagne, is to be enveloped in some pretty silk or satin, and finished off to the taste of the vender. Skin or leather thus prepared evolves a pleasant odor for years, and hence they are frequently called "the inexhaustible sachet." Being flat, they are much used for perfuming writing-paper. The lasting odor of Russia leather is familiar to all and pleasing to many; its perfume is due to the aromatic saunders-wood with which it is tanned, and to the empyreumatic oil of the bark of the birch tree, with which it is curried. The odor of Russia leather is, however, not _recherché_ enough to be considered as a perfume; but, nevertheless, leather can be impregnated by steeping in the various ottos with any sweet scent, and which it retains to a remarkable degree, especially with otto of santal or lemon-grass (_Verbena_). In this manner the odor of the peau d'Espagne can be greatly varied, and gives great satisfaction, on account of the permanence of its perfume. PERFUMED LETTER-PAPER. If a piece of peau d'Espagne be placed in contact with paper, the latter absorbs sufficient odor to be considered as "perfumed;" it is obvious that paper for writing upon must not be touched with any of the odorous tinctures or ottos, on account of such matters interfering with the fluidity of the ink and action of the pen; therefore, by the process of infection, as it were, alone can writing paper be perfumed to advantage. Besides the sachets mentioned there are many other substances applied as dry perfumes, such as scented wadding, used for quilting into all sorts of articles adapted for use in a lady's boudoir. Pincushions, jewel cases, and the like are lined with it. Cotton, so perfumed, is simply steeped in some strong essence of musk, &c. PERFUMED BOOK-MARKERS. We have seen that leather can be impregnated with odoriferous substances, in the manufacture of peau d'Espagne; just so is card-board treated prior to being made up into book-marks. In finishing them for sale, taste alone dictates their design; some are ornamented with beads, others with embroidery. CASSOLETTES AND PRINTANIERS. Cassolettes and Printaniers are little ivory boxes, of various designs, perforated in order to allow the escape of the odors contained therein. The paste used for filling these "ivory palaces whereby we are made glad," is composed of equal parts of grain musk, ambergris, seeds of the vanilla-pod, otto of roses, and orris powder, with enough gum acacia, or gum tragacantha, to work the whole together into a paste. These things are now principally used for perfuming the pocket or reticule, much in the same way that ornamental silver and gold vinagrettes are used. PASTILS. There is no doubt whatever that the origin of the use of pastils, or pastilles, as they are more often called, from the French, has been derived from the use of incense at the altars of the temples during the religious services:--"According to the custom of the priest's office, his lot (Zacharias') was to burn incense when he went into the temple of the Lord." (Luke 1:9.) "And thou shalt make an altar to burn incense.... And Aaron shall burn thereon sweet incense every morning when he dresseth the lamps, and at even when he lighteth the lamps he shall burn incense upon it." (Exodus 30.) An analogous practice is in use to the present day in the Roman Catholic churches, but, instead of being consumed upon an altar, the incense is burned in a censer, as doubtless many of our readers have seen. "As soon as the signal was given by the chief priest the incense was kindled, the holy place was filled with perfume, and the congregation without joined in prayers." (_Carpenters Temple service of the Hebrews._) THE CENSER. "On the walls of every temple in Egypt, from Meröe to Memphis, the censer is depicted smoking before the presiding deity of the place; on the walls of the tombs glow in bright colors the preparation of spices and perfumes." In the British Museum there is a vase (No. 2595) the body of which is intended to contain a lamp, the sides being perforated to admit the heat from the flame to act upon the projecting tubes; which are intended to contain ottos of flowers placed in the small vases at the end of the tubes; the heat volatilizes the ottos, and quickly perfumes an apartment. This vase or censer is from an Egyptian catacomb. [Illustration: The Censer.] The Censer, as used in the "holy places," is made either of brass, German silver, or the precious metals; its form somewhat resembles a saucer and an inverted cup, which latter is perforated, to allow the escape of the perfume. In the outer saucer is placed an inner one of copper, which can be taken out and filled with ignited charcoal. When in use, the ignited carbon is placed in the censer, and is then covered with the incense; the heat rapidly volatilizes it in visible fumes. The effect is assisted by the incense-bearer swinging the censer, attached to three long chains, in the air. The manner of swinging the censer varies slightly in the churches in Rome, in France, and in England, some holding it above the head. At LA MADELEINE the method is always to give the censer a full swing at the greatest length of the chains with the right hand, and to catch it up short with the left hand. Several samples of "incense prepared for altar service," as sent out by Mr. Martin, of Liverpool, appear to be nothing more than gum olibanum, of indifferent quality, and not at all like the composition as especially commanded by God, the form for which is given in full in Exodus. The pastils of the moderns are really but a very slight modification of the incense of the ancients. For many years they were called Osselets of Cyprus. In the old books on pharmacy a certain mixture of the then known gum-resins was called Suffitus, which being thrown upon hot ashes produced a vapor which was considered to be salutary in many diseases. It is under the same impression that pastils are now used, or at least to cover the _mal odeur_ of the sick-chamber. There is not much variety in the formula of the pastils that are now in use; we have first the INDIAN, OR YELLOW PASTILS. Santal-wood, in powder, 1 lb. Gum benzoin, 1-1/2 lb. " Tolu, 1/4 lb. Otto of santal, } " cassia, } each, 3 drachms. " cloves, } Nitrate of potass, 1-1/2 oz. Mucilage of tragacantha, q.s. to make the whole into a stiff paste. The benzoin, santal-wood, and Tolu, are to be powdered and mixed by sifting them, adding the ottos. The nitre being dissolved in the mucilage, is then added. After well beating in a mortar, the pastils are formed in shape with a pastil mould, and gradually dried. The Chinese josticks are of a similar composition, but contain no Tolu. Josticks are burned as incense in the temples of the Buddahs in the Celestial Empire, and to such an extent as to greatly enhance the value of santal-wood. DR. PARIS'S PASTILS. Benzoin, } Cascarilla, } of each, 1/4 lb. Myrrh, 1-1/4 oz. Charcoal, 1-1/2 lb. Otto of nutmegs, } of each, " cloves, } 3/4 oz. Nitre, 2 oz. Mix as in the preceding. PERFUMER'S PASTILS. Well-burned charcoal, 1 lb. Benzoin, 3/4 lb. Tolu, } Vanilla pods, } of each, 1/4 lb. Cloves, } Otto of santal, } " neroli, } of each, 2 dr. Nitre, 1-1/2 oz. Mucilage tragacantha, _q.s._ PIESSE'S PASTILS. Willow charcoal, 1/2 lb. Benzoic acid, 6 oz. Otto of thyme, } " caraway, } " rose, } of each, 1/2 dr. " lavender,} " cloves, } " santal, } Prior to mixing, dissolve 3/4 oz. nitre in half a pint of distilled or ordinary rose water; with this solution thoroughly wet the charcoal, and then allow it to dry in a warm place. When the thus nitrated charcoal is quite dry, pour over it the mixed ottos, and stir in the flowers of benzoin. When well mixed by sifting (the sieve is a better tool for mixing powders than the pestle and mortar), it is finally beaten up in a mortar, with enough mucilage to bind the whole together, and the less that is used the better. A great variety of formulæ have been published for the manufacture of pastils; nine-tenths of them contain some woods or bark, or aromatic seeds. Now, when such substances are burned, the chemist knows that if the ligneous fibre contained in them undergoes combustion--the slow combustion--materials are produced which have far from a pleasant odor; in fact, the smell of burning wood predominates over the volatilized aromatic ingredients; it is for this reason alone that charcoal is used in lieu of other substances. The use of charcoal in a pastil is merely for burning, producing, during its combustion, the heat required to quickly volatilize the perfuming material with which it is surrounded. The product of the combustion of charcoal is inodorous, and therefore does not in any way interfere with the fragrance of the pastil. Such is, however, not the case with any ingredients that may be used that are not in themselves perfectly volatile by the aid of a small increment of heat. If combustion takes place, which is always the case with all the aromatic woods that are introduced into pastils, we have, besides the volatilized otto which the wood contains, all the compounds naturally produced by the slow burning of ligneous matter, spoiling the true odor of the other ingredients volatilized. There are, it is true, certain kinds of fumigation adopted occasionally where these products are the materials sought. By such fumigation, as when brown paper is allowed to smoulder (undergo slow combustion) in a room for the purpose of covering bad smells. By the quick combustion of tobacco, that is, combustion with flame, there is no odor developed, but by its slow combustion, according to the method adopted by those who indulge in "the weed," the familiar aroma, "the cloud," is generated, and did not exist ready formed in the tobacco. Now a well-made pastil should not develope any odor of its own, but simply volatilize that fragrant matter, whatever it be, used in its manufacture. We think that the fourth formula given above carries out that object. It does not follow that the formulæ that are here given produce at all times the odor that is most approved; it is evident that in pastils, as with other perfumes, a great deal depends upon taste. Many persons very much object to the aroma of benzoin, while they greatly admire the fumes of cascarilla. THE PERFUME LAMP. Shortly after the discovery of the peculiar property of spongy platinum remaining incandescent in the vapor of alcohol, the late Mr. I. Deck, of Cambridge, made a very ingenious application of it for the purpose of perfuming apartments. An ordinary spirit lamp is filled with Eau de Cologne, and "trimmed" with a wick in the usual manner. Over the centre of the wick, and standing about the eighth of an inch above it, a small ball of spongy platinum is placed, maintained in its position by being fixed to a thin glass rod, which is inserted into the wick. [Illustration: Perfume Lamp.] Thus arranged, the lamp is to be lighted and allowed to burn until the platinum becomes red hot; the flame may then be blown out, nevertheless the platinum remains incandescent for an indefinite period. The proximity of a red-hot ball to a material of the physical quality of Eau de Cologne, diffused over a surface of cotton wick, as a matter of course causes its rapid evaporation, and as a consequence the diffusion of odor. Instead of the lamp being charged with Eau de Cologne, we may use Eau de Portugal, vervaine, or any other spirituous essence. Several perfumers make a particular mixture for this purpose, which is called EAU A BRULER. Eau de Cologne, 1 pint. Tincture of benzoin, 2 oz. " vanilla, 1 oz. Otto of thyme, } " mint, } of each, 1/2 drachm. " nutmeg, } Another form, called EAU POUR BRULER. Rectified spirit, 1 pint. Benzoic acid, 1/2 oz. Otto of thyme, } of each, 1 drachm. " caraway, } " bergamot, 2 oz. Persons who are in the habit of using the perfume lamps will, however frequently observe that, whatever difference there may be in the composition of the fluid introduced into the lamp, there is a degree of similarity in the odor of the result when the platinum is in action. This arises from the fact, that so long as there is the vapor of alcohol, mixed with oxygen-air, passing over red-hot platinum, certain definite products always result, namely, acetic acid, aldehyde, and acetal, which are formed more or less and impart a peculiar and rather agreeable fragrance to the vapor, but which overpowers any other odor that is present. FUMIGATING PAPER. There are two modes of preparing this article:-- 1. Take sheets of light cartridge paper, and dip them into a solution of alum--say, alum, one ounce; water, one pint. After they are thoroughly moistened, let them be well dried; upon one side of this paper spread a mixture of equal parts of gum benzoin, olibanum, and either balm of Tolu or Peruvian balsam, or the benzoin may be used alone. To spread the gum, &c., it is necessary that they be melted in an earthenware vessel and poured thinly over the paper, finally smoothing the surface with a hot spatula. When required for use, slips of this paper are held over a candle or lamp, in order to evaporate the odorous matter, but not to ignite it. The alum in the paper prevents it a to certain extent from burning. 2. Sheets of good light paper are to be steeped in a solution of saltpetre, in the proportions of two ounces of the salt to one pint of water, to be afterwards thoroughly dried. Any of the odoriferous gums, as myrrh, olibanum, benzoin, &c., are to be dissolved to saturation in rectified spirit, and with a brush spread upon one side of the paper, which, being hung up, rapidly dries. Slips of this paper are to be rolled up as spills, to be ignited, and then to be blown out. The nitre in the paper causes a continuance of slow combustion, diffusing during that time the agreeable perfume of the odoriferous gums. If two of these sheets of paper be pressed together before the surface is dry, they will join and become as one. When cut into slips, they form what are called Odoriferous Lighters, or Perfumed Spills. SECTION VIII. PERFUMED SOAP. The word soap, or sope, from the Greek _sapo_, first occurs in the works of Pliny and Galen. Pliny informs us that soap was first discovered by the Gauls, that it was composed of tallow and ashes, and that the German soap was reckoned the best. According to Sismondi, the French historian, a soapmaker was included in the retinue of Charlemagne. At Pompeii (overwhelmed by an eruption of Vesuvius A.D. 79), a soap-boiler's shop with soap in it was discovered during some excavations made there not many years ago. (_Starke's Letters from Italy._) From these statements it is evident that the manufacture of soap is of very ancient origin; indeed, Jeremiah figuratively mentions it--"For though thou wash thee with natron, and take thee much soap, yet thine iniquity is marked before me." (Jer. 2:22.) Mr. Wilson says that the earliest record of the soap trade in England is to be found in a pamphlet in the British Museum, printed in 1641, entitled "A short Account of the Soap Business." It speaks more particularly about the duty, which was then levied for the first time, and concerning certain patents which were granted to persons, chiefly Popish recusants, for some pretended new invention of white soap, "which in truth was not so." Sufficient is said here to prove that at that time soap-making was no inconsiderable art. It would be out of place here to enter into the details of soap-making, because perfumers do not manufacture that substance, but are merely "remelters," to use a trade term. The dyer purchases his dye-stuffs from the drysalters already fabricated, and these are merely modified under his hands to the various purposes he requires; so with the perfumer, he purchases the various soaps in their raw state from the soap-makers, these he mixes by remelting, scents and colors according to the article to be produced. The primary soaps are divided into hard and soft soaps: the hard soaps contain soda as the base; those which are soft are prepared with potash. These are again divisible into varieties, according to the fatty matter employed in their manufacture, also according to the proportion of alkali. The most important of these to the perfumer is what is termed curd soap, as it forms the basis of all the highly-scented soaps. CURD SOAP is a nearly neutral soap, of pure soda and fine tallow. OIL SOAP, as made in England, is an uncolored combination of olive oil and soda, hard, close grain, and contains but little water in combination. CASTILE SOAP, as imported from Spain, is a similar combination, but is colored by protosulphate of iron. The solution of the salt being added to the soap after it is manufactured, from the presence of alkali, decomposition of the salt takes place, and protoxide of iron is diffused through the soap of its well-known black color, giving the familiar marbled appearance to it. When the soap is cut up into bars, and exposed to the air, the protoxide passes by absorption of oxygen into peroxide; hence, a section of a bar of Castile soap shows the outer edge red-marbled, while the interior is black-marbled. Some Castile soap is not artificially colored, but a similar appearance is produced by the use of a barilla or soda containing sulphuret of the alkaline base, and at other times from the presence of an iron salt. MARINE SOAP is a cocoanut-oil soap, of soda containing a great excess of alkali, and much water combination. YELLOW SOAP is a soda soap, of tallow, resin, of lard, &c. &c. PALM SOAP is a soda soap of palm oil, retaining the peculiar odor and color of the oil unchanged. The odoriferous principle of palm oil resembling that from orris-root, can be dissolved out of it by tincturation with alcohol; like ottos generally, it remains intact in the presence of an alkali, hence, soap made of palm oil retains the odor of the oil. The public require a soap that will not shrink and change shape after they purchase it. It must make a profuse lather during the act of washing. It must not leave the skin rough after using it. It must be either quite inodorous or have a pleasant aroma. None of the above soaps possess all these qualities in union, and, therefore, to produce such an article is the object of the perfumer in his remelting process. Prior to the removal of the excise duty upon soap, in 1853, it was a commercial impossibility for a perfumer to _manufacture_ soap, because the law did not allow less than one ton of soap to be made at a time. This law, which, with certain modifications had been in force since the reign of Charles I, confined the actual manufacture of that article to the hands of a few capitalists. Such law, however, was but of little importance to the perfumer, as a soap-boiling plant and apparatus is not very compatible with a laboratory of flowers; yet, in some exceptional instances, these excise regulations interfered with him; such, for instance, as that in making soft soap of lard and potash, known, when perfumed, as _Crême d'Amande_; or unscented, as a Saponaceous Cream, which has, in consequence of that law, been entirely thrown into the hands of our continental neighbors. FIG SOFT SOAP is a combination of oils, principally olive oil of the commonest kind, with potash. NAPLES SOFT SOAP is a fish oil (mixed with Lucca oil) and potash, colored brown for the London shavers, retaining, when pure, its unsophisticated "fishy" odor. The above soaps constitute the real body or base of all the fancy scented soaps as made by the perfumers, which are mixed and remelted according to the following formula:-- The remelting process is exceedingly simple. The bar soap is first cut up into thin slabs, by pressing them against a wire fixed upon the working bench. This cutting wire (piano wire is the kind) is made taut upon the bench, by being attached to two screws. These screws regulate the height of the wire from the bench, and hence the thickness of the slabs from the bars. The soap is cut up into thin slabs, because it would be next to impossible to melt a bar whole, on account of soap being one of the worst conductors of heat. The melting pan is an iron vessel, of various sizes, capable of holding from 28 lbs. to 3 cwt., heated by a steam jacket, or by a water-bath. The soap is put into the pan by degrees, or what is in the vernacular called "rounds," that is, the thin slabs are placed perpendicularly all round the side of the pan; a few ounces of water are at the same time introduced, the steam of which assists the melting. The pan being covered up, in about half an hour the soap will have "run down." Another round is then introduced, and so continued every half hour until the whole "melting" is finished. The more water a soap contains, the easier is it melted; hence a round of marine soap, or of new yellow soap, will run down in half the time that it requires for old soap. When different soaps are being remelted to form one kind when finished, the various sorts are to be inserted into the pan in alternate rounds, but each round must consist only of one kind, to insure uniformity of condition. As the soap melts, in order to mix it, and to break up lumps, &c., it is from time to time "_crutched_." The "crutch" is an instrument or tool for stirring up the soap; its name is indicative of its form, a long handle with a short cross--an inverted 'T', curved to fit the curve of the pan. When the soaps are all melted, it is then colored, if so required, and then the perfume is added, the whole being thoroughly incorporated with the crutch. [Illustration: Frame and Slab Gauge.] The soap is then turned into the "frame." The frame is a box made in sections, in order that it can be taken to pieces, so that the soap can be cut up when cold; the sections or "lifts" are frequently made of the width of the intended bar of soap. [Illustration: Barring Gauge.] Two or three days after the soap has been in the frame, it is cool enough to cut into slabs of the size of the lifts or sections of the frame; these slabs are set up edgeways to cool for a day or two more; it is then barred by means of a wire. The lifts of the frame regulate the widths of the bars; the gauge regulates their breadth. The density of the soap being pretty well known, the gauges are made so that the soap-cutter can cut up the bars either into fours, sixes, or eights; that is, either into squares of four, six, or eight to the pound weight. Latterly, various mechanical arrangements have been introduced for soap-cutting, which in very large establishments, such as those at Marseilles in France, are great economisers of labor; but in England the "wire" is still used. [Illustration: Squaring Gauge.] [Illustration: Soap Scoop.] For making tablet shapes the soap is first cut into squares, and is then put into a mould, and finally under a press--a modification of an ordinary die or coin press. Balls are cut by hand, with the aid of a little tool called a "scoop," made of brass or ivory, being, in fact, a ring-shaped knife. Balls are also made in the press with a mould of appropriate form. The grotesque form and fruit shape are also obtained by the press and appropriate moulds. The fruit-shaped soaps, after leaving the mould, are dipped into melted wax, and are then colored according to artificial fruit-makers' rules. [Illustration: Soap Press.] [Illustration: Moulds.] The "variegated" colored soaps are produced by adding the various colors, such as smalt and vermilion, previously mixed with water, to the soap in a melted state; these colors are but slightly crutched in, hence the streaky appearance or party color of the soap; this kind is also termed "marbled" soap. ALMOND SOAP. This soap, by some persons "supposed" to be made of "sweet almond oil," and by others to be a mystic combination of sweet and bitter almonds, is in reality constituted thus:-- Finest curd soap, 1 cwt. " oil soap, 14 lbs. " marine, 14 lbs. Otto of almonds, 1-1/2 lb. " cloves, 1/4 lb. " caraway, 1/2 lb. By the time that half the curd soap is melted, the marine soap is to be added; when this is well crutched, then add the oil soap, and finish with the remaining curd. When the whole is well melted, and just before turning it into the frame, crutch in the mixed perfume. Some of the soap "houses" endeavored to use Mirabane or artificial essence of almonds (see ALMOND) for perfuming soap, it being far cheaper than the true otto of almonds; but the application has proved so unsatisfactory in practice, that it has been abandoned by Messrs. Gibbs, Pineau (of Paris), Gosnell, and others who used it. CAMPHOR SOAP. Curd soap, 28 lbs. Otto of rosemary, 1-1/4 lb. Camphor, 1-1/4 lb. Reduce the camphor to powder by rubbing it in a mortar with the addition of an ounce or more of almond oil, then sift it. When the soap is melted and ready to turn out, add the camphor and rosemary, using the crutch for mixing. HONEY SOAP. Best yellow soap, 1 cwt. Fig soft soap, 14 lbs. Otto of citronella, 1-1/2 lb. WHITE WINDSOR SOAP. Curd soap, 1 cwt. Marine soap, 21 lbs. Oil soap, 14 lbs. Otto of caraway, 1-1/2 lbs. " thyme, } " rosemary, } of each 1/2 lb. " cassia,} " cloves,} of each 1/4 lb. BROWN WINDSOR SOAP. Curd soap, 3/4 cwt. Marine soap, 1/4 " Yellow soap, 1/4 " Oil soap, 1/4 " Brown coloring (caramel), 1/2 pint. Otto of caraway, } " cloves, } " thyme, } each, 1/2 lb. " cassia, } " petit grain, } " French lavender, } SAND SOAP. Curd soap, 7 lbs. Marine soap, 7 lbs. Sifted silver sand, 28 lbs. Otto of thyme, } " cassia, } " caraway, } each, 2 oz. " French lavender, } FULLER'S EARTH SOAP. Curd soap, 10-1/2 lbs. Marine soap, 3-1/2 lbs. Fuller's earth (baked), 14 lbs. Otto of French lavender, 2 oz. " origanum, 1 oz. The above forms are indicative of the method adopted for perfuming soaps while hot or melted. All the very highly scented soaps are, however, perfumed cold, in order to avoid the loss of scent, 20 per cent. of perfume being evaporated by the hot process. The variously named soaps, from the sublime "Sultana" to the ridiculous "Turtle's Marrow," we cannot of course be expected to notice; the reader may, however, rest assured that he has lost nothing by their omission. The receipts given produce only the finest quality of the article named. Where cheap soaps are required, not much acumen is necessary to discern that by omitting the expensive perfumes, or lessening the quantity, the object desired is attained. Still lower qualities of scented soap are made by using greater proportions of yellow soap, and employing a very common curd, omitting the oil soap altogether. SCENTING SOAPS HOT. In the previous remarks, the methods explained of scenting soap involved the necessity of melting it. The high temperature of the soap under these circumstances involves the obvious loss of a great deal of perfume by evaporation. With very highly scented soaps, and with perfume of an expensive character, the loss of ottos is too great to be borne in a commercial sense; hence the adoption of the plan of SCENTING SOAPS COLD. This method is exceedingly convenient and economical for scenting small batches, involving merely mechanical labor, the tools required being simply an ordinary carpenter's plane, and a good marble mortar, and lignum vitæ pestle. The woodwork of the plane must be fashioned at each end, so that when placed over the mortar it remains firm and not easily moved by the parallel pressure of the soap against its projecting blade. To commence operations, we take first 7 lbs., 14 lbs., or 21 lbs. of the bars of the soap that it is intended to perfume. The plane is now laid upside down across the top of the mortar. Things being thus arranged, the whole of the soap is to be pushed across the plane until it is all reduced into fine shavings. Like the French "Charbonnier," who does not saw the wood, but woods the saw, so it will be perceived that in this process we do not plane the soap, but that we soap the plane, the shavings of which fall lightly into the mortar as quickly as produced. [Illustration: Soaping the Plane.] Soap, as generally received from the maker, is the proper condition for thus working; but if it has been in stock any time it becomes too hard, and must have from one to three ounces of distilled water sprinkled in the shaving for every pound of soap employed, and must lay for at least twenty-four hours to be absorbed before the perfume is added. When it is determined what size the cakes of soap are to be, what they are to sell for, and what it is intended they should cost, then the maker can measure out his perfume. In a general way, soaps scented in this way retail from 4_s._ to 10_s._ per pound, bearing about 100 per cent. profit, which is not too much considering their limited sale. The soap being in a proper physical condition with regard to moisture, &c., is now to have the perfume well stirred into it. The pestle is then set to work for the process of incorporation. After a couple of hours of "warm exercise," the soap is generally expected to be free from streaks, and to be of one uniform consistency. For perfuming soap in large portions by the cold process, instead of using the pestle and mortar as an incorporator, it is more convenient and economical to employ a mill similar in construction to a cake chocolate-mill, or a flake cocoa-mill; any mechanical apparatus that answers for mixing paste and crushing lumps will serve pretty well for blending soap together. Before going into the mill, the soap is to be reduced to shavings, and have the scent and color stirred in; after leaving it, the flakes or ribands of soap are to be finally bound together by the pestle and mortar into one solid mass; it is then weighed out in quantities for the tablets required, and moulded by the hand into egg-shaped masses; each piece being left in this condition, separately laid in rows on a sheet of white paper, dries sufficiently in a day or so to be fit for the press, which is the same as that previously mentioned. It is usual, before placing the cakes of soap in the press, to dust them over with a little starch-powder, or else to very slightly oil the mould; either of these plans prevents the soap from adhering to the letters or embossed work of the mould--a condition essential for turning out a clean well-struck tablet. The body of all the fine soaps mentioned below should consist of the finest and whitest curd soap, or of a soap previously melted and colored to the required shade, thus:-- ROSE-COLORED SOAP is curd soap stained with vermilion, ground in water, thoroughly incorporated when the soap is melted, and not very hot. GREEN SOAP is a mixture of palm oil soap and curd soap, to which is added powdered smalt ground with water. BLUE SOAP, curd soap colored with smalt. BROWN SOAP, curd soap with caramel, _i.e._ burnt sugar. The intensity of color varies, of course, with the quantity of coloring. Some kinds of soap become colored or tinted to a sufficient extent by the mere addition of the ottos used for scenting, such as "spermaceti soap," "lemon soap," &c., which become of a beautiful pale lemon color by the mere mixing of the perfume with the curd soap. OTTO OF ROSE SOAP. (_To retail at 10s. per pound_.) Curd soap (previously colored with vermilion), 4-1/2 lbs. Otto of rose, 1 oz. Spirituous extract of musk, 2 oz. Otto of santal, 1/4 oz. " geranium, 1/4 oz. Mix the perfumes, stir them in the soap shavings, and beat together. TONQUIN MUSK SOAP. Pale brown-colored curd soap, 5 lbs. Grain musk, 1/4 oz. Otto of bergamot, 1 oz. Rub the musk with the bergamot, then add it to the soap, and beat up. ORANGE-FLOWER SOAP. Curd soap, 7 lbs. Otto of neroli, 3-1/2 oz. SANTAL-WOOD SOAP. Curd soap, 7 lbs. Otto of santal, 7 oz. " bergamot, 2 oz. SPERMACETI SOAP. Curd soap, 14 lbs. Otto of bergamot, 2-1/2 lbs. " lemon, 1/2 lb. CITRON SOAP. Curd soap, 6 lbs. Otto of citron, 3/4 lb. " verbena (lemon-grass), 1/2 oz. " bergamot, 4 oz. " lemon, 2 oz. One of the best of fancy soaps that is made. FRANGIPANNE SOAP. Curd soap (previously colored light brown), 7 lbs. Civet, 1/4 oz. Otto of neroli, 1/2 oz. " santal, 1-1/2 oz. " rose, 1/4 oz. " vitivert, 1/2 oz. Rub the civet with the various ottos, mix, and beat in the usual manner. PATCHOULY SOAP. Curd soap, 4-1/2 lbs. Otto of patchouly, 1 oz. " santal, } " vitivert, } of each, 1/4 oz. SAPONACEOUS CREAM OF ALMONDS. The preparation sold under this title is a potash soft soap of lard. It has a beautiful pearly appearance, and has met with extensive demand as a shaving soap. Being also used in the manufacture of EMULSINES, it is an article of no inconsiderable consumption by the perfumer. It is made thus:-- Clarified lard, 7 lbs. Potash of lye (containing 26 per cent. of caustic potash), 3-3/4 lbs. Rectified spirit, 3 oz. Otto of almonds, 2 drachms. _Manipulation_.--Melt the lard in a porcelain vessel by a salt-water bath, or by a steam heat under 15 lbs. pressure; then run in the lye, _very slowly_, agitating the whole time; when about half the lye is in, the mixture begins to curdle; it will, however, become so firm that it cannot be stirred. The crême is then finished, but is not pearly; it will, however, assume that appearance by long trituration in a mortar, gradually adding the alcohol, in which has been dissolved the perfume. SOAP POWDERS. These preparations are sold sometimes as a dentifrice and at others for shaving; they are made by reducing the soap into shavings by a plane, then thoroughly drying them in a warm situation, afterwards grinding in a mill, then perfuming with any otto desired. RYPOPHAGON SOAP. Best yellow soap, } Fig soft soap, } equal parts melted together. Perfume with anise and citronella. AMBROSIAL CREAM. Color the grease very strongly with alkanet root, then proceed as for the manufacture of saponaceous cream. The cream colored in this way has a blue tint; when it is required of a purple color we have merely to stain the white saponaceous cream with a mixture of vermilion and smalt to the shade desired. Perfume with otto of oringeat. TRANSPARENT SOFT SOAP. Solution caustic potash (_Lond. Ph_.), 6 lbs. Olive oil, 1 lb. Perfume to taste. Before commencing to make the soap, reduce the potash lye to one half its bulk by continued boiling. Now proceed as for the manufacture of saponaceous cream. After standing a few days, pour off the waste liquor. TRANSPARENT HARD SOAP. Reduce the soap to shavings, and dry them as much as possible, then dissolve in alcohol, using as little spirit as will effect the solution, then color and perfume as desired, and cast the product in appropriate moulds; finally dry in a warm situation. Until the Legislature allows spirit to be used for manufacturing purposes, free of duty, we cannot compete with our neighbors in this article. JUNIPER TAR SOAP. This soap is made from the tar of the wood of the _Juniperus communis_, by dissolving it in a fixed vegetable oil, such as almond or olive oil, or in fine tallow, and forming a soap by means of a weak soda lye, after the customary manner. This yields a moderately firm and clear soap, which may be readily used by application to parts affected with eruptions at night, mixed with a little water, and carefully washed off the following morning. This soap has lately been much used for eruptive disorders, particularly on the Continent, and with varying degrees of success. It is thought that the efficient element in its composition is a rather less impure hydrocarburet than that known in Paris under the name _huile de cade_. On account of its ready miscibility with water, it possesses great advantage over the common tar ointment. MEDICATED SOAPS. Six years ago I began making a series of medicated soaps, such as SULPHUR SOAP, IODINE SOAP, BROMINE SOAP, CREOSOTE SOAP, MERCURIAL SOAP, CROTON OIL SOAP, and many others. These soaps are prepared by adding the medicant to curd soap, and then making in a tablet form for use. For sulphur soap, the curd soap may be melted, and flowers of sulphur added while the soap is in a soft condition. For antimony soap and mercurial soap, the low oxides of the metals employed may also be mixed in the curd soap in a melted state. Iodine, bromine, creosote soap, and others containing very volatile substances, are best prepared cold by shaving up the curd soap in a mortar, and mixing the medicant with it by long beating. In certain cutaneous diseases the author has reason to believe that they will prove of infinite service as auxiliaries to the general treatment. It is obvious that the absorbent vessels of the skin are very active during the lavoratory process; such soap must not, therefore, be used except by the special advice of a medical man. Probably these soaps will be found useful for internal application. The precedent of the use of Castile soap (containing oxide of iron) renders it likely that when prejudice has passed away, such soaps will find a place in the pharmacopoeias. The discovery of the solubility, under certain conditions, of the active alkaloids, quinine, morphia, &c., in oil, by Mr. W. Bastick, greatly favors the supposition of analogous compounds in soap. SECTION IX. EMULSINES. From soaps proper we now pass to those compounds used as substitutes for soap, which are classed together under one general title as above, for the reason that all cosmetiques herein embraced have the property of forming emulsions with water. Chemically considered, they are an exceedingly interesting class of compounds, and are well worthy of study. Being prone to decomposition, as might be expected from their composition, they should be made only in small portions, or, at least, only in quantities to meet a ready sale. While in stock they should be kept as cool as possible, and free from a damp atmosphere. AMANDINE. Fine almond oil, 7 lbs. Simple syrup,[E] 4 oz. White soft soap, or saponaceous cream, _i.e._ } Crême d'Amande, } 1 oz. Otto of almonds, 1 oz. " bergamot, 1 oz. " cloves, 1/2 oz. Rub the syrup with the soft soap until the mixture is homogeneous, then rub in the oil by degrees; the perfume having been previously mixed with the oil. [Illustration: Oil-Runner in Emulsine Process.] In the manufacture of amandine (and olivine) the difficulty is to get in the quantity of oil indicated, without which it does not assume that transparent jelly appearance which good amandine should have. To attain this end, the oil is put into "a runner," that is, a tin or glass vessel, at the bottom of which is a small faucet and spigot, or tap. The oil being put into this vessel is allowed to run slowly into the mortar in which the amandine is being made, just as fast as the maker finds that he can incorporate it with the paste of soap and syrup; and so long as this takes place, the result will always have a jelly texture to the hand. If, however, the oil be put into the mortar quicker than the workman can blend it with the paste, then the paste becomes "oiled," and may be considered as "done for," unless, indeed, the whole process be gone through again, starting off with fresh syrup and soap, using up the greasy mass as if it were pure oil. This liability to "go off," increases as the amandine nears the finish; hence extra caution and plenty of "elbow grease" must be used during the addition of the last two pounds of oil. If the oil be not perfectly fresh, or if the temperature of the atmosphere be above the average of summer heat, it will be almost impossible to get the whole of the oil given in the formula into combination; when the mass becomes bright and of a crystalline lustre, it will be well to stop the further addition of oil to it. This and similar compounds should be potted as quickly as made, and the lids of the pots banded either with strips of tin-foil or paper, to exclude air. When the amandine is filled into the jars, the top or face of it is marked or ornamented with a tool made to the size of half the diameter of the interior of the jar, in a similar way to a saw; a piece of lead or tortoise-shell, being serrated with an angular file, or piece of an "old saw," will do very well; place the marker on the amandine, and turn the jar gently round. OLIVINE. Gum acacia, in powder, 2 oz. Honey, 6 oz. Yolk of eggs, in number, 5. White soft soap, 3 oz. Olive oil, 2 lbs. Green oil, 1 oz. Otto of bergamot, 1 oz. " lemon, 1 oz. " cloves, 1/2 oz. " thyme and cassia, each, 1/2 drachm. Rub the gum and honey together until incorporated, then add the soap and egg. Having mixed the green oil and perfumes with the olive oil, the mixture is to be placed in the runner, and the process followed exactly as indicated for amandine. HONEY AND ALMOND PASTE. (_Pâte d'Amande au Miel_.) Bitter almonds, blanched and ground, 1/2 lb. Honey, 1 lb. Yolk of eggs, in number, 8. Almond oil, 1 lb. Otto of bergamot, 1/4 oz. " cloves, 1/4 oz. Rub the eggs and honey together first, then gradually add the oil, and finally the ground almonds and the perfume. ALMOND PASTE. Bitter almonds, blanched and ground, 1-1/2 lb. Rose-water, 1-1/2 pint. Alcohol (60 o.p.), 16 oz. Otto of bergamot, 3 oz. Place the ground almonds and one pint of the rose-water into a stewpan; with a slow and steady heat, cook the almonds until their granular texture assumes a pasty form, constantly stirring the mixture during the whole time, otherwise the almonds quickly burn to the bottom of the pan, and impart to the whole an empyreumatic odor. The large quantity of otto of almonds which is volatilized during the process, renders it essential that the operator should avoid the vapor as much as possible. When the almonds are nearly cooked, the remaining water is to be added; finally the paste is put into a mortar, and well rubbed with the pestle; then the perfume and spirit are added. Before potting this paste, as well as honey paste, it should be passed through a medium fine sieve, to insure uniformity of texture, especially as almonds do not grind kindly. Other pastes, such as _Pâte de Pistache_, _Pâte de Cocos_, _Pâte de Guimauve_, are prepared in so similar a manner to the above that it is unnecessary to say more about them here, than that they must not be confounded with preparations bearing a similar name made by confectioners. ALMOND MEAL. Ground almonds, 1 lb. Wheat flour, 1 lb. Orris-root powder, 1/4 lb. Otto of lemon, 1/2 oz. " almonds, 1/4 drachm. PISTACHIO NUT MEAL, OR ANY OTHER NUT. Pistachio nuts (decorticated as almonds } are bleached), } 1 lb. Orris powder, 1 lb. Otto of neroli, 1 drachm. " lemons, 1/2 oz. Other meals, such as perfumed oatmeal, perfumed bran, &c., are occasionally in demand, and are prepared as the foregoing. All the preceding preparations are used in the lavatory process as substitutes for soap, and to "render the skin pliant, soft, and fair!" EMULSIN AU JASMIN. Saponaceous cream, 1 oz. Simple syrup, 1-1/2 oz. Almond oil, 1 lb. Best jasmine oil, 1/2 lb. EMULSIN A LE VIOLETTE. Saponaceous cream, 1 oz. Syrup of violets, 1-1/2 oz. Best violet oil, 1-1/2 lb. Emulsin of other odors can be prepared with tubereuse, rose, or cassie (acacia) oil (prepared by enfleurage or maceration). For the methods of mixing the ingredients, see "Amandine," p. 195. On account of the high price of the French oils, these preparations are expensive, but they are undoubtedly the most exquisite of cosmetiques. SECTION X. MILK, OR EMULSIONS. In the perfumery trade, few articles meet with a more ready sale than that class of cosmetiques denominated milks. It has long been known that nearly all the seeds of plants which are called nuts, when decorticated and freed from their pellicle, on being reduced to a pulpy mass, and rubbed with about four times their weight of water, produce fluid which has every analogy to cow's milk. The milky appearance of these emulsions is due to the minute mechanical division of the oil derived from the nuts being diffused through the water. All these emulsions possess great chemical interest on account of their rapid decomposition, and the products emanating from their fermentation, especially that made with sweet almonds and pistachios (_Pistachia vera_). In the manufacture of various milks for sale, careful manipulation is of the utmost importance, otherwise these emulsions "will not keep;" hence more loss than profit. "Transformation takes place in the elements of vegetable caseine (existing in seeds) from _the very moment_ that sweet almonds are converted into almond-milk."--LIEBIG. This accounts for the difficulty many persons find in making milk of almonds that does not spontaneously divide, a day or so after its manufacture. MILK OF ROSES. Valencia almonds (blanched), 1/2 lb. Rose-water, 1 quart. Alcohol (60 o.p.), 1/4 pint. Otto of rose, 1 drachm. White wax, spermaceti, oil soap, each, 1/2 oz. _Manipulation_.--Shave up the soap, and place it in a vessel that can be heated by steam or water-bath; add to it two or three ounces of rose-water. When the soap is perfectly melted, add the wax and spermaceti, without dividing them more than is necessary to obtain the correct weight; this insures their melting slowly, and allows time for their partial saponification by the fluid soap; occasional stirring is necessary. While this is going on, blanch the almonds, carefully excluding every particle that is in the least way damaged. Now proceed to beat up the almonds in a scrupulously clean mortar, allowing the rose-water to trickle into the mass by degrees; the runner, as used for the oil in the manufacture of olivine, is very convenient for this purpose. When the emulsion of almonds is thus finished, it is to be strained, _without pressure_, through clean _washed_ muslin (_new_ muslin often contains starch, flour, gum, or dextrine). The previously-formed saponaceous mixture is now to be placed in the mortar, and the ready-formed emulsion in the runner; the soapy compound and the emulsion is then carefully blended together. As the last of the emulsion runs into the mortar, the spirit, in which the otto of roses has been dissolved, is to take its place, and to be _gradually_ trickled into the other ingredients. A too sudden addition of the spirit frequently coagulates the milk and causes it to be curdled; as it is, the temperature of the mixture rises, and every means must be taken to keep it down; the constant agitation and cold mortar effecting that object pretty well. Finally, the now formed milk of roses is to be strained. The almond residue may be washed with a few ounces of fresh rose-water, in order to prevent any loss in bulk to the whole given quantity. The newly-formed milk should be placed into a bottle having a tap in it about a quarter of an inch from the bottom. After standing perfectly quiet for twenty-four hours it is fit to bottle. All the above precautions being taken, the milk of roses will keep any time without precipitate or creamy supernatation. These directions apply to all the other forms of milk now given. MILK OF ALMONDS. Bitter almonds (blanched), 10 oz. Distilled (or rose) water, 1 quart. Alcohol (60 o.p.), 3/4 pint.[F] Otto of almonds, 1/2 drachm. " bergamot, 2 drachms. Wax, spermaceti, } Almond oil, curd soap, } each, 1/2 oz. MILK OF ELDER. Sweet almonds, 4 oz. Elder-flower water, 1 pint. Alcohol (60 o.p.), 8 oz. Oil of elder flowers, prepared by maceration, 1/2 oz. Wax, sperm, soap, each, 1/2 oz. MILK OF DANDELION. Sweet almonds, 4 oz. Rose-water, 1 pint. Expressed juice of dandelion root, 1 oz. Esprit tubereuse, 8 oz. Green oil, wax, } Curd soap, } each 1/2 oz. Let the juice of the dandelion be perfectly fresh pressed; as it is in itself an emulsion, it may be put into the mortar after the almonds are broken up, and stirred with the water and spirit in the usual manner. MILK OF CUCUMBER. Sweet almonds, 4 oz. Expressed juice of cucumbers, 1 pint. Spirit (60 o.p.), 8 oz. Essence of cucumbers, 1/4 pint. Green oil, wax, } Curd soap, } each 1/2 oz. Raise the juice of the cucumbers to the boiling point for half a minute, cool it as quickly as possible, then strain through fine muslin; proceed to manipulate in the usual manner. ESSENCE OF CUCUMBERS. Break up in a mortar 28 lbs. of good fresh cucumbers; with the pulp produced mix 2 pints rectified spirit (sp. gr. .837), and allow the mixture to stand for a day and night; then distil the whole, and draw off a pint and a half. The distillation may be continued so as to obtain another pint fit for ulterior purposes. CREME DE PISTACHE. (_Milk of Pistachio Nuts_.) Pistachio nuts, 3 oz. Orange-flower water, 3-1/4 pints. Esprit neroli, 3/4 pint. Palm soap, } Green oil, wax, } each, 1 oz. Spermaceti, } LAIT VIRGINAL. Rose-water, 1 quart. Tincture benzoin, 1/2 oz. Add the water very slowly to the tincture; by so doing an opalescent milky fluid is produced, which will retain its consistency for many years; by reversing this operation, pouring the tincture into the water, a cloudy precipitate of the resinous matter ensues, which does not again become readily suspended in the water. EXTRACT OF ELDER FLOWERS. Elder-flower water, 1 quart. Tincture benzoin, 1 oz. Manipulate as for virgin's milk. Similar compounds may, of course, be made with orange-flower and other waters. SECTION XI. COLD CREAM. GALEN, the celebrated physician of Pergamos, in Asia, but who distinguished himself at Athens, Alexandria, and Rome, about 1700 years ago, was the inventor of that peculiar unguent, a mixture of grease and water, which is now distinguished as cold cream in perfumery, and as _Ceratum Galeni_ in Pharmacy. The modern formula for cold cream is, however, quite a different thing to that given in the works of Galen in point of odor and quality, although substantially the same--grease and water. In perfumery there are several kinds of cold cream, distinguished by their odor, such as that of camphor, almond, violet, roses, &c. Cold cream, as made by English perfumers, bears a high reputation, not only at home, but throughout Europe; the quantity exported, and which can only be reckoned by jars in hundreds of dozens, and the repeated announcements that may be seen in the shops on the Continent, in Germany, France, and Italy, of "Cold Crême Anglaise," is good proof of the estimation in which it is held. ROSE COLD CREAM. Almond oil, 1 lb. Rose-water, 1 lb. White wax, } spermaceti, } each, 1 oz. Otto of roses, 1/2 drachm. _Manipulation_.--Into a well-glazed thick porcelain vessel, which should be deep in preference to shallow, and capable of holding twice the quantity of cream that is to be made, place the wax and sperm; now put the jar into a boiling bath of water; when these materials are melted, add the oil, and again subject the whole to heat until the flocks of wax and sperm are liquefied; now remove the jar and contents, and set it under a runner containing the rose-water: the runner may be a tin can, with a small tap at the bottom, the same as used for the manufacture of milk of roses. A stirrer must be provided, made of lancewood, flat, and perforated with holes the size of a sixpence, resembling in form a large palette-knife. As soon as the rose-water is set running, the cream must be kept agitated until the whole of the water has passed into it; now and then the flow of water must be stopped, and the cream which sets at the sides of the jar scraped down, and incorporated with that which remains fluid. When the whole of the water has been incorporated, the cream will be cool enough to pour into the jars for sale; at that time the otto of rose is to be added. The reason for the perfume being put in at the last moment is obvious--the heat and subsequent agitation would cause unnecessary loss by evaporation. Cold cream made in this way sets quite firmly in the jars into which it is poured, and retains "a face" resembling pure wax, although one-half is water retained in the interstices of the cream. When the pots are well glazed, it will keep good for one or two years. If desired for exportation to the East or West Indies, it should always be sent out in stoppered bottles. COLD CREAM OF ALMONDS Is prepared precisely as the above; but in place of otto of roses otto of almonds is used. VIOLET COLD CREAM. Huile violette, 1 lb. Rose-water, 1 lb. Wax and spermaceti, each, 1 oz. Otto of almonds, 5 drops. VIOLET COLD CREAM. IMITATION. Almond oil, 3/4 lb. Huile cassie, 1/4 lb. Rose-water, 1 lb. Sperm and wax, 1 oz. Otto of almonds, 1/4 drachm. This is an elegant and economical preparation, generally admired. TUBEREUSE, JASMINE, AND FLEUR D'ORANGE COLD CREAMS. Are prepared in similar manner to violet (first form); they are all very exquisite preparations, but as they _cost_ more than rose cold cream, perfumers are not much inclined to introduce them in lieu of the latter. CAMPHOR COLD CREAM. (_Otherwise Camphor Ice_.) Almond oil, 1 lb. Rose-water, 1 lb. Wax and Spermaceti, 1 oz. Camphor, 2 oz. Otto of rosemary, 1 drachm. Melt the camphor, wax, and sperm, in the oil, then manipulate as for cold cream of roses. CUCUMBER COLD CREAM. (_Crême de Concombre_.) Almond oil, 1 lb. Green oil, 1 oz. Juice of cucumber, 1 lb. Wax and sperm, each, 1 oz. Otto of neroli, 1/4 drachm. The cucumber juice is readily obtained by subjecting the fruit to pressure in the ordinary tincture press. It must be raised to a temperature high enough to coagulate the small portion of albumen which it contains, and then strained through fine linen, as the heat is detrimental to the odor on account of the great volatility of the otto of cucumber. The following method may be adopted with advantage:--Slice the fruit very fine with a cucumber-cutter, and place them in the oil; after remaining together for twenty-four hours, repeat the operation, using fresh fruit in the strained oil; no warmth is necessary, or at most, not more than a summer heat; then proceed to make the cold cream in the usual manner, using the almond oil thus odorized, the rose-water, and other ingredients in the regular way, perfuming, if necessary, with a little neroli. Another and commoner preparation of cucumber is found among the Parisians, which is lard simply scented with the juice from the fruit, thus:--The lard is liquefied by heat in a vessel subject to a water-bath; the cucumber juice is then stirred well into it; the vessel containing the ingredients is now placed in a quiet situation to cool. The lard will rise to the surface, and when cold must be removed from the fluid juice; the same manipulation being repeated as often as required, according to the strength of odor of the fruit desired in the grease. PIVERS' POMADE OF CUCUMBER. Benzoinated lard, 6 lbs. Spermaceti, 2 lbs. Essence of cucumbers, 1 lb. Melt the stearine with the lard, then keep it constantly in motion while it cools, now beat the grease in a mortar, gradually adding the essence of cucumbers; continue to beat the whole until the spirit is evaporated, and the pomade is beautifully white. _Melons_ and other similar fruit will scent grease treated in the same way. (See "Essence of Cucumbers," p. 204.) POMADE DIVINE. Among the thousand and one quack nostrums, pomade divine, like James's powder, has obtained a reputation far above the most sanguine expectations of its concoctors. This article strictly belongs to the druggist, being sold as a remedial agent; nevertheless, what _is_ sold is almost always vended by the perfumer. It is prepared thus:-- Spermaceti, 1/4 lb. Lard, 1/2 lb. Almond oil, 3/4 lb. Gum benzoin, 1/4 lb. Vanilla beans, 1-1/2 oz. Digest the whole in a vessel heated by a water-bath at a temperature not exceeding 90° C. After five or six hours it is fit to strain, and may be poured into the bottles for sale. (Must be _stamped_ if its medicinal qualities are stated.) ALMOND BALLS. Purified suet, 1 lb. White wax, 1/2 lb. Otto of almonds, 1 drachm. " cloves, 1/4 drachm. CAMPHOR BALLS. Purified suet, 1 lb. White wax, 1/2 lb. Camphor, 1/4 lb. Otto of French lavender or rosemary, 1/2 oz. Both the above articles are sold either white or colored with alkanet root. When thoroughly melted, the material is cast in a mould; ounce gallipots with smooth bottoms answer very well for casting in. Some venders use only large pill-boxes. CAMPHOR PASTE. Sweet almond oil, 1/2 lb. Purified lard, 1/4 lb. Wax and spermaceti, } Camphor, } each, 1 oz. GLYCERINE BALSAM. White wax, } Spermaceti, } each, 1 oz. Almond oil, 1/2 lb. Glycerine, 2 oz. Otto of roses, 1/4 drachm. Of the remedial action of any of the above preparations we cannot here discuss; in giving the formulæ, it is enough for us that they are sold by perfumers. ROSE LIP SALVE. Almond oil, 1/2 lb. Spermaceti and wax, each, 2 oz. Alkanet root, 2 oz. Otto of roses, 1/4 drachm. Place the wax, sperm, and oil on to the alkanet root in a vessel heated by steam or water-bath; after the materials are melted, they must digest on the alkanet to extract its color for at least four or five hours; finally, strain through fine muslin, then add the perfume just before it cools. WHITE LIP SALVE. Almond oil, 1/4 lb. Wax and Spermaceti, each, 1 oz. Otto of almonds, 1/2 drachm. " geranium, 1/4 " After lip salve is poured into the pots and got cold, a red-hot iron must be held over them for a minute or so, in order that the heat radiated from the irons may melt the surface of the salve and give it an even face. COMMON LIP SALVE Is made simply of equal parts of lard and suet, colored with alkanet root, and perfumed with an ounce of bergamot to every pound of salve. SECTION XII. POMADES AND OILS. The name of pomatum is derived from _pomum_, an apple, because it was originally made by macerating over-ripe apples in grease. If an apple be stuck all over with spice, such as cloves, then exposed to the air for a few days, and afterwards macerated in purified melted lard, or any other fatty matter, the grease will become perfumed. Repeating the operation with the same grease several times, produces real "pomatum." According to a recipe published more than a century ago the form given is:--"Kid's grease, an orange sliced, pippins, a glass of rose-water, and half a glass of white wine, boiled and strained, and at last sprinkled with oil of sweet almonds." The author, Dr. Quincy, observes, that "the apple is of no significance at all in the recipe," and, like many authors of the present day, concludes that the reader is as well acquainted with the subject as the writer, and therefore considers that the weights or bulk of the materials in his recipe are, likewise, of no significance. According to ancient writers, unguent, pomatum, ointment, are synonymous titles for medicated and perfumed greases. Among biblical interpreters, the significant word is mostly rendered "ointment;" thus we have in Prov. 27:9, "Ointment and perfume rejoice the heart;" in Eccles. 9:8, "Let thy head lack no ointment." Perfumers, acting upon their own or Dr. Quincy's advice, pay no regard to the apples in the preparation of pomatum, but make it by perfuming lard or suet, or a mixture of wax, spermaceti, and oil, or some of them or all blended, to produce a particular result, according to the name that it bears. The most important thing to consider in the manufacture of pomatum, &c., is to start off with a _perfectly inodorous_ grease, whatever that grease may be. Inodorous lard is obtained thus:--Take, say 28 lbs. of _perfectly fresh_ lard, place it in a well-glazed vessel, that can be submitted to the heat of a boiling salt-water bath, or by steam under a slight pressure; when the lard is melted, add to it one ounce of powdered alum and two ounces of table salt; maintain the heat for some time, in fact till a scum rises, consisting in a great measure of coagulated proteine compounds, membrane, &c., which must be skimmed off; when the liquid grease appears of a uniform nature it is allowed to grow cold. The lard is now to be washed. This is done in small portions at a time, and is a work of much labor, which, however, is amply repaid by the result. About a pound of the grease is now placed on a slate slab a little on the incline, a supply of good water being set to trickle over it; the surface of the grease is then constantly renewed by an operative working a muller over it, precisely as a color-maker grinds paints in oil. In this way the water removes any traces of alum or salt, also the last traces of nitrogenous matter. Finally, the grease, when the whole is washed in this way, is remelted, the heat being maintained enough to drive off any adhering water. When cold it is finished. Although purifying grease in this way is troublesome, and takes a good deal of time, yet unless done so, it is totally unfit for perfuming with flowers, because a bad grease will cost more in perfume to cover its _mal odeur_ than the expense of thus deodorizing it. Moreover, if lard be used that "smells of the pig," it is next to impossible to impart to it any delicate odor; and if strongly perfumed by the addition of ottos, the unpurified grease will not keep, but quickly becomes rancid. Under any circumstances, therefore, grease that is not _perfectly inodorous_ is a very expensive material to use in the manufacture of pomades. In the South and flower-growing countries, where the fine pomades are made by ENFLEURAGE, or by MACERATION[G] (see pp. 37, 38), the purification of grease for the purpose of these manufactures is of sufficient importance to become a separate trade. The purification of beef and mutton suet is in a great measure the same as that for lard: the greater solidity of suets requires a mechanical arrangement for washing them of a more powerful nature than can be applied by hand labor. Mr. Ewen, who is undoubtedly the best fat-purifier in London, employs a stone roller rotating upon a circular slab; motion is given to the roller by an axle which passes through the centre of the slab, or rather stone bed, upon which the suet is placed; being higher in the centre than at the sides, the stream of water flows away after it has once passed over the suet; in other respects the treatment is the same as for lard. These greases used by perfumers have a general title of "body," tantamount to the French nomenclature of _corps_; thus we have pomades of hard corps (suet), pomades of soft corps (lard). For making _extraits_, such as extrait de violette, jasmin, the pomades of hard corps are to be preferred; but when scented pomade is to be used in fabrication of unguents for the hair, pomades of soft corps are the most useful. The method of perfuming grease by the direct process with flowers having already been described under the respective names of the flowers that impart the odor thereto, it remains now only to describe those compounds that are made from them, together with such incidental matter connected with this branch of perfumery as has not been previously mentioned. ACACIA POMADE, commonly called CASSIE POMATUM, is made with a purified body-grease, by maceration with the little round yellow buds of the _Acacia Farnesiana_. Black currant leaves, and which the French term _cassie_, have an odor very much resembling cassie (acacia), and are used extensively for adulterating the true acacia pomades and oils. The near similarity of name, their analogous odor (although the plants have no botanical connection), together with the word _cassia_, a familiar perfume in England, has produced generally confused ideas in this country as to the true origin of the odor now under discussion. Cassie, casse, cassia, it will be understood now, are three distinct substances; and in order to render the matter more perspicuous in future, the materials will always be denominated ACACIA, if prepared from the _Acacia Farnesiana_; CASSE, when from _black currant_; and CASSIA, if derived from the bark of the _Cinnamomum Cassia_. BENZOIN POMADE AND OIL. Benzoic acid is perfectly soluble in hot grease. Half an ounce of benzoic acid being dissolved in half a pint of hot olive or almond oil, deposits on cooling beautiful acicular crystals, similar to the crystals that effloresce from vanilla beans; a portion of the acid, however, remains dissolved in the oil at the ordinary temperature, and imparts to it the peculiar aroma of benzoin; upon this idea is based the principle of perfuming grease with gum benzoin by the direct process, that is, by macerating powdered gum benzoin in melted suet or lard for a few hours, at a temperature of about 80° C. to 90° C. Nearly all the gum-resins give up their odoriferous principle to fatty bodies, when treated in the same way; this fact becoming generally known, will probably give rise to the preparation of some new remedial ointments, such as _Unguentum myrrhæ_, _Unguentum assafoetida_, and the like. TONQUIN POMADE, and TONQUIN OIL, are prepared by macerating the ground Tonquin beans in either melted fat or warm oil, from twelve to twenty-eight hours, in the proportion of Tonquin beans, 1/2 lb. Fat or oil, 4 lbs. Strain through fine muslin; when cold, the grease will have a fine odor of the beans. VANILLA OIL AND POMADE. Vanilla pods, 1/4 lb. Fat or oil, 4 lbs. Macerate at a temperature of 25° C. for three or four days; finally strain. These pomatums and oils, together with the French pomades and huiles already described, constitute the foundation of the preparations of all the best hair greases sold by perfumers. Inferior scented pomatums and oils are prepared by perfuming lard, suet, wax, oil, &c., with various ottos; the results, however, in many instances more expensive than the foregoing, are actually inferior in their odor or bouquet--for grease, however slightly perfumed by maceration or enfleurage with flowers, is far more agreeable to the olfactory nerve than when scented by ottos. The undermentioned greases have obtained great popularity, mainly because their perfume is lasting and flowery. POMADE CALLED BEAR'S GREASE. The most popular and "original" bears' grease is made thus:-- Huile de rose, } " fleur d'orange, } " acacia, } of each, 1/2 lb. " tubereuse and jasmin,} Almond oil, 10 lbs. Lard, 12 lbs. Acacia pomade, 2 lbs. Otto of bergamot, 4 oz. " cloves, 2 oz. Melt the solid greases and oils together by a water-bath, then add the ottos. Bears' grease thus prepared is just hard enough to "set" in the pots at a summer heat. In very warm weather, or if required for exportation to the East or West Indies, it is necessary to use in part French pomatums instead of oils, or more lard and less almond oil. CIRCASSIAN CREAM. Purified lard, 1 lb. Benzoin suet, 1 lb. French rose pomatum, 1/2 lb. Almond oil, colored with alkanet, 2 lbs. Otto of rose, 1/4 oz. BALSAM OF FLOWERS. French rose pomatum, 12 oz. " violet pomatum, 12 oz. Almond oil, 2 lbs. Otto of bergamot, 1/4 oz. CRYSTALLIZED OIL. (_First quality_). Huile de rose, 1 lb. " tubereuse, 1 lb. " fleur d'orange, 1/2 lb. Spermaceti, 8 oz. CRYSTALLIZED OIL. (_Second quality_.) Almond, 2-1/2 lbs. Spermaceti, 1/2 lb. Otto of lemon, 3 oz. Melt the spermaceti in a vessel heated by a water-bath, then add the oils; continue the heat until all flocks disappear; let the jars into which it is poured be warm; cool as slowly as possible, to insure good crystals; if cooled rapidly, the mass congeals without the appearance of crystals. This preparation has a very nice appearance, and so far sells well; but its continued use for anointing the hair renders the head scurfy; indeed, the crystals of sperm may be combed out of the hair in flakes after it has been used a week or two. CASTOR OIL POMATUM. Tubereuse pomatum, 1 lb. Castor oil, 1/2 lb. Almond oil, 1/2 lb. Otto of bergamot, 1 oz. BALSAM OF NEROLI. French rose pomatum, 1/2 lb. " jasmine pomatum, 1/2 lb. Almond oil, 3/4 lb. Otto of neroli, 1 drachm. MARROW CREAM. Purified lard, 1 lb. Almond oil, 1 lb. Palm oil, 1 oz. Otto of cloves, 1/2 drachm. " bergamot, 1/2 oz. " lemon, 1-1/2 oz. MARROW POMATUM. Purified lard, 4 lbs. " suet, 2 lbs. Otto of lemon, 1 oz. " bergamot, 1/2 oz. " cloves, 3 drachms. Melt the greases, then beat them up with a whisk or flat wooden spatula for half an hour or more; as the grease cools, minute vesicles of air are inclosed by the pomatum, which not only increase the bulk of the mixtures, but impart a peculiar mechanical aggregation, rendering the pomatum light and spongy; in this state it is obvious that it fills out more profitably than otherwise. COMMON VIOLET POMATUM. Purified lard, 1 lb. _Washed_ acacia pomatum, 6 oz. " rose pomatum, 4 oz. Manipulate as for marrow pomatum. In all the cheap preparations for the hair, the manufacturing perfumers used the washed French pomatums and the washed French oils for making their greases. Washed pomatums and washed oils are those greases that originally have been the best pomatums and huiles prepared by enfleurage and by maceration with the flowers; which pomades and huiles have been subject to digestion in alcohol for the manufacture of essences for the handkerchief. After the spirit has been on the pomatums, &c., it is poured off; the residue is then called _washed_ pomatum, and still retain an odor strong enough for the manufacture of most hair greases. For pomatums of other odors it is only necessary to substitute rose, jasmine, tubereuse, and others, in place of the acacia pomatum in the above formulæ. POMADE DOUBLE, MILLEFLEURS. Rose, jasmine, fleur d'orange, violet, tubereuse, &c., are all made in winter, with two-thirds best French pomatum, one-third best French oils; in summer, equal parts. POMADE A LA HELIOTROPE. French rose pomade, 1 lb. Vanilla oil, 1/2 lb. Huile de jasmine, 4 oz. " tubereuse, 2 oz. " fleur d'orange, 2 oz. Otto of almonds, 6 drops. " cloves, 3 drops. HUILE ANTIQUE. (_A la Heliotrope_.) Same as the above, substituting rose oil for the pomade. PHILOCOME. The name of this preparation, which is a compound of Greek and Latin, signifying "a friend to the hair," was first introduced by the Parisian perfumers; and a very good name it is, for Philocome is undoubtedly one of the best unguents for the hair that is made. PHILOCOME. (_First quality_.) White wax, 10 oz. Fresh rose-oil, 1 lb. " acacia oil, 1/2 lb. " jasmine oil, 1/2 lb. " fleur d'orange oil, 1 lb. " tubereuse oil, 1 lb. Melt the wax in the huiles by a water-bath, at the lowest possible temperature. Stir the mixture as it cools; do not pour out the Philocome until it is nearly cool enough to set; let the jars, bottles, or pots into which it is filled for sale be slightly warmed, or at least of the same temperature as the Philocome, otherwise the bottles chill the material as it is poured in, and make it appear of an uneven texture. PHILOCOME. (_Second quality_.) White wax, 5 oz. Almond oil, 2 lbs. Otto of bergamot, 1 oz. " lemon, 1/2 oz. " lavender, 2 drachms. " cloves, 1 drachm. FLUID PHILOCOME. Take 1 ounce of wax to 1 pound of oil. POMMADE HONGROISE. (_For the Moustache_.) Lead plaster, 1 lb. Acacia huile, 2 oz. Otto of roses, 2 drachms. " cloves, 1 drachm. " almonds, 1 drachm. Color to the tint required with ground amber and sienna in oil; mix the ingredients by first melting the plaster in a vessel in boiling water. Lead plaster is made with oxide of lead boiled with olive oil: it is best to procure it ready made from the wholesale druggists. HARD OR STICK POMATUMS. Purified suet, 1 lb. White wax, 1 lb. Jasmine pomatum, 1/2 lb. Tubereuse pomatum, 1/2 lb. Otto of rose, 1 drachm. ANOTHER FORM,--_cheaper_. Suet, 1 lb. Wax, 1/2 lb. Otto of bergamot, 1 oz. " cassia, 1 drachm. The above recipes produce WHITE BATONS. BROWN and BLACK BATONS are also in demand. They are made in the same way as the above, but colored with lamp-black or umber ground in oil. Such colors are best purchased ready ground at an artist's colorman's. BLACK AND BROWN COSMETIQUE. Such as is sold by RIMMEL, is prepared with a nicely-scented soap strongly colored with lamp-black or with umber. The soap is melted, and the coloring added while the soap is soft; when cold it is cut up in oblong pieces. It is used as a temporary dye for the moustache, applied with a small brush and water. SECTION XIII. HAIR DYES AND DEPILATORY. By way of personal adornment, few practices are of more ancient origin than that of painting the face, dyeing the hair, and blackening the eyebrows and eyelashes. It is a practice universal among the women of the higher and middle classes in Egypt, and very common among those of the lower orders, to blacken the edge of the eyelids, both above and below the eye, with a black powder, which they term _kohhl_. The kohhl is applied with a small probe of wood, ivory, or silver, tapering towards the end, but blunt. This is moistened sometimes with rose-water, then dipped in the powder, and drawn along the edges of the eyelids. It is thought to give a very soft expression to the eye, the size of which, in appearance, it enlarges; to which circumstances probably Jeremiah refers when he writes, "Though thou rentest thy face (or thine eyes) with painting, in vain shalt thou make thyself fair."--_Jer._ 4:30. See also LANE'S _Modern Egyptians_, vol. i, p. 41, et seq. A singular custom is observable both among Moorish and Arab females--that of ornamenting the face between the eyes with clusters of bluish spots or other small devices, and which, being stained, become permanent. The chin is also spotted in a similar manner, and a narrow blue line extends from the point of it, and is continued down the throat. The eyelashes, eyebrows, and also the tips and extremities of the eyelids, are colored black. The soles, and sometimes other parts of the feet, as high as the ankles, the palms of the hands, and the nails, are dyed with a yellowish-red, with the leaves of a plant called Henna (_Lawsonia inermis_), the leaf of which somewhat resembles the myrtle, and is dried for the purposes above mentioned. The back of the hand is also often colored and ornamented in this way with different devices. On holidays they paint their cheeks of a red brick color, a narrow red line being also drawn down the temples. In Greece, "for coloring the lashes and sockets of the eye they throw incense or gum labdanum on some coals of fire, intercept the smoke which ascends with a plate, and collect the soot. This I saw applied. A girl, sitting cross-legged as usual on a sofa, and closing one of her eyes, took the two lashes between the forefinger and thumb of her left hand, pulled them forward, and then, thrusting in at the external corner a sort of bodkin or probe which had been immersed in the soot, and withdrawing it, the particles previously adhering to the probe remained within the eyelashes."--CHANDLER'S _Travels in Greece._ Dr. Shaw states that among other curiosities that were taken out of the tombs at Sahara relating to Egyptian women, he saw a joint of the common reeds, which contained one of these bodkins and an ounce or more of this powder. In England the same practice is adopted by many persons that have gray hair; but instead of using the black material in the form of a powder, it is employed as a crayon, the color being mixed with a greasy body, such as the brown and black stick pomatums, described in the previous article. TURKISH HAIR DYE. In Constantinople there are some persons, particularly Armenians, who devote themselves to the preparation of cosmetics, and obtain large sums of money from those desirous of learning this art. Amongst these cosmetics is a black dye for the hair, which, according to Landerer, is prepared in the following manner:-- Finely pulverized galls are kneaded with a little oil to a paste, which is roasted in an iron pan until the oil vapors cease to evolve, upon which the residue is triturated with water into a paste, and heated again to dryness. At the same time a metallic mixture, which is brought from Egypt to the commercial marts of the East, and which is termed in Turkish _Rastiko-petra_, or _Rastik-Yuzi_, is employed for this purpose. This metal, which looks like dross, is by some Armenians intentionally fused, and consists of iron and copper. It obtains its name from its use for the coloration of the hair, and particularly the eyebrows--for _rastik_ means eyebrows, and _yuzi_ stone. The fine powder of this metal is as intimately mixed as possible with the moistened gall-mass into a paste, which is preserved in a damp place, by which it acquires the blackening property. In some cases this mass is mixed with, the powder of odorous substances which are used in the seraglio as perfumes, and called _harsi_, that is, pleasant odor; and of these the principal ingredient is ambergris. To blacken the hair a little of this dye is triturated in the hand or between the fingers, with which the hair or beard is well rubbed. After a few days the hair becomes very beautifully black, and it is a real pleasure to see such fine black beards as are met with in the East among the Turks who use this black dye. Another and important advantage in the use of this dye consists therein, that the hair remains soft, pliant, and for a long time black, when it has been once dyed with this substance. That the coloring properties of this dye are to be chiefly ascribed to the pyrogallic acid, which can be found by treating the mass with water, may be with certainty assumed. LITHARGE HAIR DYE. Powdered litharge, 2 lbs. Quicklime, 1/2 lb. Calcined magnesia, 1/2 lb. Slake the lime, using as little water as possible to make it disintegrate, then mix the whole by a sieve. ANOTHER WAY. Slaked lime, 3 lbs. White lead in powder, 2 lbs. Litharge, 1 lb. Mix by sifting, bottle, and well cork. _Directions_ to be sold with the above.--"Mix the powder with enough water to form a thick creamy fluid; with the aid of a small brush; completely cover the hair to be dyed with this mixture; to dye a light brown, allow it to remain on the hair four hours; dark brown, eight hours; black, twelve hours. As the dye does not act unless it is moist, it is necessary to keep it so by wearing an oiled silk, india-rubber, or other waterproof cap. "After the hair is dyed, the refuse must be thoroughly washed from the head with plain water; when dry, the hair must be oiled." SIMPLE SILVER DYE. (_Otherwise "Vegetable Dye._") Nitrate of silver, 1 oz. Rose-water, 1 pint. Before using this dye it is necessary to free the hair from grease by washing it with soda or pearlash and water. The hair must be quite dry prior to applying the dye, which is best laid on with an old tooth-brush. This dye does not "strike" for several hours. It needs scarcely be observed that its effects are more rapidly produced by exposing the hair to sunshine and air. HAIR DYE, WITH MORDANT. (_Brown._) Nitrate of silver, 1 oz., blue bottles. Rose-water, 9 oz. " _The mordant_.--Sulphuret of potassium, 1 oz., white bottles. " Water, 8 oz. " HAIR DYE, WITH MORDANT. (_Black._) Nitrate of silver, 1 oz., blue bottles. Water, 6 oz. " _The mordant_.--Sulphuret of potassium, 1 oz., white bottles. " Water, 6 oz. " The mordant is to be applied to the hair first; when dry, the silver solution. Great care must be taken that the sulphuret is fresh made, or at least, well preserved in closed bottles, otherwise, instead of the mordant acting to make to make the hair black, it will tend to impart a _yellow_ hue. When the mordant is good, it has a very disagreeable odor, and although this is the quickest and best dye, its unpleasant smell has given rise to the INODOROUS DYE. _Blue bottles._--Dissolve the nitrate of silver in the water as in the above, then add liquid ammonia by degrees until the mixture becomes cloudy from the precipitate of the oxide of silver, continue to add ammonia in small portions until the fluid again becomes bright from the oxide of silver being redissolved. _White bottles_.--Pour half a pint of boiling rose-water upon three ounces of powdered gall-nuts; when cold, strain and bottle. This forms the mordant, and is used in the same way as the first-named dye, like the sulphuret mordant. It is not so good a dye as the previous one. FRENCH BROWN DYE. _Blue Bottles_.--Saturated solution of sulphate of copper; to this add ammonia enough to precipitate the oxide of copper and redissolve it (as with the silver in the above), producing the azure liquid. _White Bottles_.--_Mordant_.--Saturated solution of prussiate of potass. Artificial hair, for the manufacture of perukes, is dyed in the same manner as wool. There are in the market several other hair dyes, but all of them are but modifications of the above, possessing no marked advantage. LEAD DYE. Liquid hair dye, not to blacken the skin, may be thus prepared:--Dissolve in one ounce of liquor potassæ as much freshly-precipitated oxide of lead as it will take up, and dilute the resulting clear solution with three ounces of distilled water. Care must be taken not to wet the skin unnecessarily with it. QUICK DEPILATORY OR RUSMA. (_For removing hair._) As the ladies of this country consider the growth of hair upon the upper lip, upon the arms, and on the back of the neck, to be detrimental to beauty, those who are troubled with such physical indications of good health and vital stamina have long had recourse to rusma or depilatory for removing it. This or analogous preparations were introduced into this country from the East, rusma having been in use in the harems of Asia for many ages. Best lime slaked, 3 lb. Orpiment, in powder, 1/2 lbs. Mix the material by means of a drum sieve; preserve the same for sale in well-corked or stoppered bottles. _Directions_ to be sold with the above. Mix the depilatory powder with enough water to render it of a creamy consistency; lay it upon the hair for about five minutes, or until its caustic action upon the skin renders it necessary to be removed; a similar process to shaving is then to be gone through, but instead of using a razor, operate with an ivory or bone paper-knife; then wash the part with plenty of water, and apply a little cold cream. The precise time to leave depilatory upon the part to be depilated cannot be given, because there is a physical difference in the nature of hair. "Raven tresses" require more time than "flaxen locks;" the sensitiveness of the skin has also to be considered. A small feather is a very good test for its action. A few readers will, perhaps, be disappointed in finding that I have only given one formula for depilatory. The receipts might easily have been increased in number, but not in quality. The use of arsenical compounds is objectionable, but it undoubtedly increases the depilating action of the compounds. A few compilers of "Receipt Books," "Supplements to Pharmacopoeias," and others, add to the lime "charcoal powder," "carbonate of potass," "starch," &c.; but what action have these materials--chemically--upon hair? The simplest depilatory is moistened quicklime, but it is less energetic than the mixture recommended above; it answers very well for tanners and fellmongers, with whom time is no object. SECTION XIV. ABSORBENT POWDERS. A lady's toilet-table is incomplete without a box of some absorbent powder; indeed, from our earliest infancy, powder is used for drying the skin with the greatest benefit; no wonder that its use is continued in advanced years, if, by slight modifications in its composition, it can be employed not only as an absorbent, but as a means of "personal adornment." We are quite within limits in stating that many ton-weights of such powders are used in this country annually. They are principally composed of various starches, prepared from wheat, potatoes, and various nuts, mixed more or less with powdered talc--of Haüy, steatite (soap-stone), French chalk, oxide of bismuth, and oxide of zinc, &c. The most popular is what is termed VIOLET POWDER. Wheat starch, 12 lbs. Orris-root powder, 2 lbs. Otto of lemon, 1/2 oz. " bergamot, 3/4 oz. " cloves, 2 drachms. ROSE FACE POWDER. Wheat starch, 7 lbs. Rose Pink, 1/2 drachm. Otto of rose, 2 drachms. " santal, 2 " PLAIN OR UNSCENTED HAIR POWDER Is pure wheat starch. FACE POWDER. Starch, 1 lb. Oxide of Bismuth, 4 oz. PERLE POWDER. French chalk, 1 lb. Oxide of bismuth, 1 oz. Oxide of zinc, 1 oz. BLANC DE PERLE Is pure oxide of bismuth in powder. FRENCH BLANC Is levigated talc passed through a silk sieve. This is the best face powder made, particularly as it does not discolor from emanation of the skin or impure atmosphere. LIQUID BLANC (FOR THEATRICAL USE). The use of a white paint by actresses and dancers, is absolutely necessary; great exertion produces a florid complexion, which is incompatible with certain scenic effects, and requires a cosmetic to subdue it. Madame V----, during her stage career, has probably consumed more than half a hundredweight of oxide of bismuth, prepared thus:-- Rose or orange-flower water, 1 pint. Oxide of bismuth, 4 oz. Mixed by long trituration. CALCINED TALC Is also extensively used as a toilet powder, and is sold under various names; it is not so unctuous as the ordinary kind. ROUGE AND RED PAINTS. These preparations are in demand, not only for theatrical use, but by private individuals. Various shades of color are made, to suit the complexions of the blonde and brunette. One of the best kind is that termed BLOOM OF ROSES. Strong liquid ammonia, 1/2 oz. Finest carmine, 1/4 oz. Rose-water, 1 pint. Esprit de rose (triple), 1/2 oz. Place the carmine into a pint bottle, and pour on it the ammonia; allow them to remain together, with occasional agitation, for two days; then add the rose-water and esprit, and well mix. Place the bottle in a quiet situation for a week; any precipitate of impurities from the carmine will subside; the supernatant "Bloom of Roses" is then to be bottled for sale. If the carmine was perfectly pure there would be no precipitate; nearly all the carmine purchased from the makers is more or less sophisticated, its enormous price being a premium to its adulteration. Carmine cannot be manufactured _profitably_ on a small scale for commercial purposes; four or five manufacturers supply the whole of Europe! M. Titard, Rue Grenier St. Lazare, Paris, produces, without doubt, the finest article; singular enough, however, the principal operative in the establishment is an old Englishman. "The preparation of the finest carmine is still a mystery, because, on the one hand, its consumption being very limited, few persons are engaged in its manufacture, and, upon the other, the raw material being costly, extensive experiments on it cannot be conveniently made."--DR. URE. In the _Encyclopédie Roret_ will be found no less than a dozen recipes for preparing carmine; the number of formulæ will convince the most superficial reader that the true form is yet withheld. Analysis has taught us its exact composition; but a certain dexterity of manipulation and proper temperature are indispensable to complete success. Most of the recipes given by Dr. Ure, and others, are from this source; but as they possess no practical value we refrain from reprinting them. TOILET ROUGES. Are prepared of different shades by mixing fine carmine with talc powder, in different proportions, say, one drachm of carmine to two ounces of talc, or one of carmine to three of talc, and so on. These rouges are sold in powder, and also in cake or china pots; for the latter the rouge is mixed with a minute portion of solution of gum tragacanth. M. Titard prepares a great variety of rouges. In some instances the coloring-matter of the cochineal is spread upon thick paper and dried very gradually; it then assumes a beautiful green tint. This curious optical effect is also observed in "pink saucers." What is known as Chinese book rouge is evidently made in the same way, and has been imported into this country for many years. When the bronze green cards are moistened with a piece of damp cotton wool, and applied to the lips or cheeks, the color assumes a beautiful rosy hue. Common sorts of rouge, called "theatre rouge," are made from the Brazil-wood lake; another kind is derived from the safflower (_Carthamus tinctorius_); from this plant also is made PINK SAUCERS. The safflower is washed in water until the yellow coloring-matter is removed; the carthamine or color principle is then dissolved out by a weak solution of carbonate of soda; the coloring is then precipitated into the saucers by the addition of sulphuric acid to the solution. Cotton wool and crape being colored in the same way are used for the same purpose, the former being sold as Spanish wool, the latter as Crépon rouge. SECTION XV. TOOTH POWDERS AND MOUTH WASHES. TOOTH powders, regarded as a means merely of cleansing the teeth, are most commonly placed among cosmetics; but this should not be, as they assist greatly in preserving a healthy and regular condition of the dental machinery, and so aid in perfecting as much as possible the act of mastication. In this manner, they may be considered as most useful, although it is true, subordinate medicinal agents. By a careful and prudent use of them, some of the most frequent causes of early loss of the teeth may be prevented; these are, the deposition of tartar, the swelling of the gums, and an undue acidity of the saliva. The effect resulting from accumulation of the tartar is well known to most persons, and it has been distinctly shown that swelling of the substance of the gums will hasten the expulsion of the teeth from their sockets; and the action of the saliva, if unduly acid, is known to be at least injurious, if not destructive. Now, the daily employment of a tooth powder sufficiently hard, so as to exert a tolerable degree of friction upon the teeth, without, at the same time, injuring the enamel of the teeth, will, in most cases, almost always prevent the tartar accumulating in such a degree as to cause subsequent injury to the teeth; and a flaccid, spongy, relaxed condition of the gums may be prevented or overcome by adding to such a tooth powder, some tonic and astringent ingredient. A tooth powder containing charcoal and cinchona bark, will accomplish these results in most cases, and therefore dentists generally recommend such. Still, there are objections to the use of charcoal; it is too hard and resisting, its color is objectionable, and it is perfectly insoluble by the saliva, it is apt to become lodged between the teeth, and there to collect decomposing animal and vegetable matter around such particles as may be fixed in this position. Cinchona bark, too, is often stringy, and has a bitter, disagreeable taste. M. Mialhe highly recommends the following formula:-- MIALHE'S TOOTH POWDER. Sugar of milk, one thousand parts; lake, ten parts; pure tannin, fifteen parts; oil of mint, oil of aniseed, and oil of orange flowers, so much as to impart an agreeable flavor to the composition. His directions for the preparation of this tooth powder, are, to rub well the lake with the tannin, and gradually add the sugar of milk, previously powdered and sifted; and lastly, the essential oils are to be carefully mixed with the powdered substances. Experience has convinced him of the efficacy of this tooth powder, the habitual employment of which, will suffice to preserve the gums and teeth in a healthy state. For those who are troubled with excessive relaxation and sponginess of the gums, he recommends the following astringent preparation:-- MIALHE'S DENTIFRICE. Alcohol, one thousand parts; genuine kino, one hundred parts; rhatany root, one hundred parts; tincture of balsam of tolu, two parts; tincture of gum benzoin, two parts; essential oil of canella, two parts; essential oil of mint, two parts; essential oil of aniseed, one part. The kino and the rhatany root are to be macerated in the alcohol for seven or eight days; and after filtration, the other articles are to be added. A teaspoonful of this preparation mixed in three or four spoonfuls of water, should be used to rinse the mouth, after the use of the tooth powder. CAMPHORATED CHALK. Precipitated chalk, 1 lb. Powdered orris-root, 1/2 lb. Powdered camphor, 1/4 lb. Reduce the camphor to powder by rubbing it in a mortar with a little spirit, then sift the whole well together. On account of the volatility of camphor, the powder should always be sold in bottles, or at least in boxes lined with tinfoil. QUININE TOOTH POWDER. Precipitated chalk, 1 lb. Starch Powder, 1/2 lb. Orris powder, 1/2 lb. Sulphate of quinine, 1 drachm. After sifting, it is ready for sale. PREPARED CHARCOAL. Fresh-made charcoal in fine powder, 7 lbs. Prepared chalk, 1 lb. Orris-root, 1 lb. Catechu, 1/2 lb. Cassia bark, 1/2 lb. Myrrh, 1/4 lb. Sift. PERUVIAN BARK POWDER. Peruvian bark in powder, 1/2 lb. Bole Ammoniac, 1 lb. Orris powder, 1 lb. Cassia bark, 1/2 lb. Powdered myrrh, 1/2 lb. Precipitated chalk, 1/2 lb. Otto of cloves, 3/4 oz. HOMOEOPATHIC CHALK. Precipitated chalk, 1 lb. Powder orris, 1 oz. " starch, 1 oz. CUTTLE FISH POWDER. Powdered cuttle-fish, 1/2 lb. Precipitated chalk, 1 lb. Powder orris, 1/2 lb. Otto of lemons, 1 oz. " neroli, 1/2 drachm. BORAX AND MYRRH TOOTH POWDER. Precipitated chalk, 1 lb. Borax powder, 1/2 lb. Myrrh powder, 1/4 lb. Orris, 1/4 lb. FARINA PIESSE'S POWDER. Precipitated chalk, 2 lbs. Orris-root, 2 lbs. Rose pink, 1 drachm. Very fine powdered sugar, 1/2 lb. Otto of neroli, 1/2 drachm. " lemons, 1/4 oz. " bergamot, 1/4 oz. " orange-peel, 1/4 oz. " rosemary, 1 drachm. ROSE TOOTH POWDER. Precipitated chalk, 1 lb. Orris, 1/2 lb. Rose pink, 2 drachms. Otto of rose, 1 drachm. " santal, 1/4 drachm. OPIATE TOOTH PASTE. Honey, 1/2 lb. Chalk, 1/2 lb. Orris, 1/2 lb. Rose Pink, 2 drachms. Otto of cloves, } " nutmeg, } each, 1/2 drachm. " rose, } Simple syrup, enough to form a paste. MOUTH WASHES. VIOLET MOUTH WASH. Tincture of orris, 1/2 pint. Esprit de rose, 1/2 pint. Spirit, 1/2 pint. Otto of almonds, 5 drops. EAU BOTOT. Tincture of cedar wood, 1 pint. " myrrh, 1/4 pint. " rhatany, 1/4 pint. Otto of peppermint, 5 drops. All these tinctures should be made with grape spirit, or at least with pale unsweetened brandy. BOTANIC STYPTIC. Rectified spirit, 1 quart. Rhatany root, } Gum myrrh, } of each, 2 oz. Whole cloves, } Macerate for fourteen days, and strain. TINCTURE OF MYRRH AND BORAX. Spirits of wine, 1 quart. Borax, } Honey, } of each, 1 oz. Gum myrrh, 1 oz. Red sanders wood, 1 oz. Rub the honey and borax well together in a mortar, then gradually add the spirit, which should not be stronger than .920, _i.e._ proof spirit, the myrrh, and sanders wood, and macerate for fourteen days. TINCTURE OF MYRRH WITH EAU DE COLOGNE. Eau de Cologne, 1 quart. Gum myrrh, 1 oz. Macerate for fourteen days, and filter. CAMPHORATED EAU DE COLOGNE. Eau de Cologne, 1 quart. Camphor, 5 oz. SECTION XVI. HAIR WASHES. ROSEMARY WATER. Rosemary free from stalk, 10 lbs. Water, 12 gallons. Draw off by distillation ten gallons for use in perfumery manufacture. ROSEMARY HAIR WASH. Rosemary water, 1 gallon. Rectified spirit, 1/2 pint. Pearlash, 1 oz. Tinted with brown coloring. ATHENIAN WATER. Rose-water, 1 gallon. Alcohol, 1 pint. Sassafras wood, 1/4 lb. Pearlash, 1 oz. Boil the wood in the rose-water in a glass vessel; then, when cold, add the pearlash and spirit. VEGETABLE OR BOTANIC EXTRACT. Rose-water, } Rectified spirits, } of each, 2 quarts. Extrait de fleur d'orange, } " jasmin, } " acacia, } of each, 1/4 pint. " rose, } " tubereuse, } Extract of vanilla, 1/2 pint. This is a very beautifully-scented hair wash. It retails at a price commensurate with its cost. ASTRINGENT EXTRACT OF ROSES AND ROSEMARY. Rosemary water, 2 quarts. Esprit de rose, 1/2 pint. Rectified spirit, 1-1/2 pint. Extract of vanilla, 1 quart. Magnesia to clear it, 2 oz. Filter through paper. SAPONACEOUS WASH. Rectified spirit, 1 pint. Rose-water, 1 gallon. Extract of rondeletia, 1/2 pint. Transparent soap, 1/2 oz. Hay saffron, 1/2 drachm. Shave up the soap very fine; boil it and the saffron in a quart of the rose-water; when dissolved, add the remainder of the water, then the spirit, finally the rondeletia, which is used by way of perfume. After standing for two or three days, it is fit for bottling. By transmitted light it is transparent, but by reflected light the liquid has a pearly and singular wavy appearance when shaken. A similar preparation is called Egg Julep. BANDOLINES. Various preparations are used to assist in dressing the hair in any particular form. Some persons use for that purpose a hard pomatum containing wax, made up into rolls, called thence _Baton Fixeteur._ The little "feathers" of hair, with which some ladies are troubled, are by the aid of these batons made to lie down smooth. For their formula, see p. 224, 225. The liquid bandolines are principally of a gummy nature, being made either with Iceland moss, or linseed and water variously perfumed, also by boiling quince-seed with water. Perfumers, however, chiefly make bandoline from gum tragacanth, which exudes from a shrub of that name which grows plentifully in Greece and Turkey. ROSE BANDOLINE. Gum tragacanth, 6 oz. Rose-water, 1 gallon. Otto of roses, 1/2 oz. Steep the gum in the water for a day or so. As it swells and forms a thick gelatinous mass, it must from time to time be well agitated. After about forty-eight hours' maceration it is then to be squeezed through a coarse clean linen cloth, and again left to stand for a few days, and passed through a linen cloth a second time, to insure uniformity of consistency; when this is the case, the otto of rose is to be thoroughly incorporated. The cheap bandoline is made without the otto; for colored bandoline, it is to be tinted with ammoniacal solution of carmine, i.e. _Bloom of Roses_. See p. 236. ALMOND BANDOLINE Is made precisely as the above, scenting with a quarter of an ounce of otto of almonds in place of the roses. "Nor the sweet smell Of different flowers in odor and in hue Can make me any longer story tell." Shakspeare. [Illustration] APPENDIX. * * * * * MANUFACTURE OF GLYCERINE. Glycerine is generally made on the large scale, on the one hand, by directly saponifying oil with the oxide of lead, or, on the other, from the "waste liquor" of soap manufacturers. To obtain glycerine by means of the first of these methods is the reverse of simple, and at the same time somewhat expensive; and by means of the second process, the difficulty of entirely separating the saline matters of the waste liquor renders it next to impossible to procure a perfectly pure result. To meet both these difficulties, and to meet the steadily increasing demand for glycerine, Dr. Campbell Morfit recommends the following process, which, he asserts, he has found, by experience, to combine the desirable advantages of economy as regards time, trouble, and expense. One hundred pounds of oil, tallow, lard, or stearin are to be placed in a clean iron-bound barrel, and melted by the direct application of a current of steam. Whilst still fluid and warm, add to it fifteen pounds of lime, previously slaked, and made into a milky mixture with two and a half gallons of water; then cover the vessel, and continue the steaming for several hours, or until the saponification shall be completed. This may be known when a sample of the soap when cold gives a smooth and bright surface on being scraped with the finger-nail, and at the same time, breaks with a crackling noise. By this process the fat or oil is decomposed, its acids uniting with the lime to form insoluble lime-soap, while the eliminated glycerine remains in solution in the water along with the excess of the lime. After it has been sufficiently boiled, it is allowed to cool and to settle, and it is then to be strained. The strained liquid contains only the glycerine and excess of lime, and requires to be carefully concentrated by heated steam. During evaporation, a portion of the lime is deposited, on account of its lesser solubility in hot than in cold water. The residue is removed by treating the evaporated liquid with a current of carbonic acid gas, boiling by heated steam to convert a soluble bicarbonate of lime that may have been formed into insoluble neutral carbonate, decanting or straining off the clear supernatant liquid from the precipitated carbonate of lime, and evaporating still further, as before, if necessary, so as to drive off any excess of water. As nothing fixed or injurious is employed in this process, glycerine, prepared in this manner, may be depended upon for its almost absolute purity. M. Jahn's process is as follows:-- Take of finely-powdered litharge five pounds, and olive oil nine pounds. Boil them together over a gentle fire, constantly stirring, with the addition occasionally of a small quantity of warm water, until the compound has the consistence of plaster. Jahn boils this plaster for half an hour with an equal weight of water, keeping it at the same time constantly stirred. When cold, he pours off the supernatant fluid, and repeats the boiling three times at least with a fresh portion of water. The sweet fluids which result are mixed, and evaporated to six pounds, and sulphuretted hydrogen conducted through them as long as sulphuret of lead is precipitated. The liquid filtered from the sulphuret of lead is to be reduced to a thin syrupy consistence by evaporation. To remove the brown coloring matter, it must be treated with purified animal charcoal. However, this agent does not prevent the glycerine becoming slightly colored upon further evaporation. It possesses also still a slight smell and taste of lead plaster, which may be removed by diluting it with water, and by digestion with animal charcoal, and some fresh burnt-wood charcoal. After filtration, this liquid must be evaporated until it has acquired a specific gravity of 1.21, when it will be found to be free from smell, and of a pale yellow color. For the preparation of glycerine, distilled water is necessary, to prevent it being contaminated with the impurities of common water. Jahn obtained, by this method, from the above quantity of lead plaster, upwards of seven ounces of glycerine.--_Archives der Pharmacie_. * * * * * TEST FOR ALCOHOL IN ESSENTIAL OILS. J.J. Bernoulli recommends for this purpose acetate of potash. When to an ethereal oil, contaminated with alcohol, dry acetate of potash is added, this salt dissolves in the alcohol, and forms a solution from which the volatile oil separates. If the oil be free from alcohol, this salt remains dry therein. Wittstein, who speaks highly of this test, has suggested the following method of applying it as the best:--In a dry test-tube, about half an inch in diameter, and five or six inches long, put no more than eight grains of powdered dry acetate of potash; then fill the tube two-thirds full with the essential oil to be examined. The contents of the tube must be well stirred with a glass rod, taking care not to allow the salt to rise above the oil; afterwards set aside for a short time. If the salt be found at the bottom of the tube dry, it is evident that the oil contains no spirit. Oftentimes, instead of the dry salt, beneath the oil is found a clear syrupy fluid, which is a solution of the salt in the spirit, with which the oil was mixed. When the oil contains only a little spirit, a small portion of the solid salt will be found under the syrupy solution. Many essential oils frequently contain a trace of water, which does not materially interfere with this test, because, although the acetate of potash becomes moist thereby, it still retains its pulverent form. A still more certain result may be obtained by distillation in a water-bath. All the essential oils which have a higher boiling-point than spirit, remain in the retort, whilst the spirit passes into the receiver with only a trace of the oil, where the alcohol may be recognized by the smell and taste. Should, however, a doubt exist, add to the distillate a little acetate of potash and strong sulphuric acid, and heat the mixture in a test-tube to the boiling-point, when the characteristic odor of acetic ether will be manifest, if any alcohol be present. * * * * * DETECTION OF POPPY AND OTHER DRYING OILS IN ALMOND AND OLIVE OILS. It is known that the olein of the drying oils may be distinguished from the olein of those oils which remain greasy in the air by the first not being convertible into elaidic acid, consequently it does not become solid. Professor Wimmer has recently proposed a convenient method for the formation of elaidin, which is applicable for the purpose of detecting the adulteration of almond and olive oils with drying oils. He produces nitrous acid by treating iron filings in a glass bottle with nitric acid. The vapor of nitrous acid is conducted through a glass tube into water, upon which the oil to be tested is placed. If the oil of almonds or olives contains only a small quantity of poppy oil when thus treated, it is entirely converted into crystallized elaidin, whilst the poppy oil swims on the top in drops. * * * * * COLORING MATTER OF VOLATILE OILS. BY G.E. SACHSSE. It is well known that most ethereal oils are colorless; however, there are a great number colored, some of which are blue, some green, and some yellow. Up to the present time the question has not been decided, whether it is the necessary property of ethereal oils to have a color, or whether their color is not due to the presence of some coloring matter which can be removed. It is most probable that their color arises from the presence of a foreign substance, as the colored ethereal oils can at first, by careful distillation, be obtained colorless, whilst later the colored portion passes over. Subsequent appearances lead to the solution of the question, and are certain evidence that ethereal oils, when they are colored, owe their color to peculiar substances which, by certain conditions, may be communicated from one oil to another. When a mixture of oils of wormwood, lemons, and cloves is subjected to distillation, the previously green-colored oil of wormwood passes over, at the commencement, colorless, while, towards the end of the distillation, after the receiver has been frequently charged, the oil of cloves distils over in very dense drops of a dark green color. It therefore appears that the green coloring matter of the oil of wormwood has been transferred to the oil of cloves.--_Zeitschrift für Pharmacie._ * * * * * ARTIFICIAL PREPARATION OF OIL OF CINNAMON. BY A. STRECKER. Some years since, Strecker has shown that styrone, which is obtained when styracine is treated with potash, is the alcohol of cinnamic acid. Wolff has converted this alcohol by oxidizing agents into cinnamic acid. The author has now proved that under the same conditions by which ordinary alcohol affords aldehyde, styrone affords the aldehyde of cinnamic acid, that is, oil of cinnamon. It is only necessary to moisten platinum black with styrone, and let it remain in the air some days, when by means of the bisulphite of potash the aldehyde double compound may be obtained in crystals, which should be washed in ether. By the addition of diluted sulphuric acid, the aldehyde of cinnamic acid is afterwards procured pure. These crystals also dissolve in nitric acid, and then form after a few moments crystals of the nitrate of the hyduret of cinnamyle. The conversion of styrone into the hyduret of cinnamyle by the action of the platinum black is shown by the following equation: C_{18}H_{10}O_{2} + 2 O = C_{18}H_{8}O_{2} + 2 HO.--_Comptes Rendus._ * * * * * DETECTION OF SPIKE OIL AND TURPENTINE IN LAVENDER OIL BY DR. J. GASTELL. There are two kinds of lavender oil known in commerce; one, which is very dear, and is obtained from the flowers of the _Lavandula vera_; the other is much cheaper, and is prepared from the flowers of the _Lavandula spica_. The latter is generally termed oil of spike. In the south of France, whether the oil be distilled from the flowers of the _Lavandula vera_ or _Lavandula spica_, it is named oil of lavender. By the distillation of the whole plant or only the stalk and the leaves, a small quantity of oil is obtained, which is rich in camphor, and is there called oil of spike. Pure oil of lavender should have a specific gravity from .876 to .880, and be completely soluble in five parts of alcohol of a specific gravity of .894. A greater specific gravity shows that it is mixed with oil of spike; and a less solubility, that it contains oil of turpentine. * * * * * DIFFERENT ORANGE-FLOWER WATERS FOUND IN COMMERCE BY M. LEGUAY. There are three sorts of orange-flower waters found in commerce. The first is distilled from the flowers; the second is made with distilled water and neroli; and the third is distilled from the leaves, the stems, and the young unripe fruit of the orange tree. The first may be easily distinguished by the addition of a few drops of sulphuric acid to some of the water in a tube; a fine rose color is almost immediately produced. The second also gives the same color when it is freshly prepared; but after a certain time, two or three months at the farthest, this color is no longer produced, and the aroma disappears completely. The third is not discolored by the addition of the sulphuric acid; it has scarcely any odor, and that rather an odor of the lemon plant than of orange-flowers.--_Bulletin de la Société Pharmaceutique d'Indre et Loire._ * * * * * A FORMULA FOR CONCENTRATED ELDER-FLOWER WATER. Krembs recommends the following process for making a concentrated elder-flower water, from which he states the ordinary water can be extemporaneously prepared, of excellent quality, and of uniform strength:--2 lbs. of the flowers are to be distilled with water until that which passes into the receiver has lost nearly all perfume. This will generally happen when from 15 to 18 pounds have passed over. To the distillate, 2 lbs. of alcohol are to be added, and the mixture distilled until about 5 lbs. are collected. This liquor contains all the odor of the flowers. To make the ordinary water, 2 ounces of the concentrated water are to be added to 10 ounces of distilled water.--_Buchner's Report._ * * * * * PRACTICAL REMARKS ON SPIRIT OF WINE. BY THOMAS ARNALL. The strength of spirit of wine is, by law, regulated by proof spirit (sp. gr. .920) as a standard; and accordingly as it is either stronger or weaker than the above, it is called so much per cent. above or below proof. The term _per cent._ is used in this instance in a rather peculiar sense. Thus, spirit of wine at 56 per cent. overproof, signifies that 100 gallons of it are equal to 156 gallons of proof spirit; while a spirit at 20 per cent. underproof, signifies that 100 gallons are equal to 80 gallons at proof. The rectified spirit of the Pharmacopoeia is 56 per cent. overproof, and may be reduced to proof by strictly adhering to the directions there given, viz., to mix five measures with three of water. The result, however, will not be eight measures of proof spirit; in consequence of the _contraction_ which ensues, there will be a deficiency of about [Symbol: oz.]iv in each gallon. This must be borne in mind in preparing tinctures. During a long series of experiments on the preparation of ethers, it appeared a desideratum to find a ready method of ascertaining how much spirit of any density would be equal to one chemical equivalent of absolute alcohol. By a modification of a rule employed by the Excise, this question may be easily solved. The Excise rule is as follows:-- To reduce from any given strength to any required strength, _add_ the _overproof_ per centage _to_ 100, or _subtract_ the _underproof_ per centage _from_ 100. Multiply the result by the quantity of spirit, and divide the product by the number obtained by _adding_ the _required_ per centage overproof, or _subtracting_ the _required_ per centage underproof, to or from 100, as the case may be. The result will give the measure of the spirit at the strength required. Thus, suppose you wished to reduce 10 gallons of spirit, at 54 overproof, down to proof, add 54 to 100 = 154; multiply by the quantity, 10 gallons (154 × 10) = 1540. The required strength being proof, of course there is nothing either to add to or take from 100; therefore, 1540 divided by 100 = 15.4 gallons at proof; showing that 10 gallons must be made to measure 15 gallons, 3 pints, 4 fl. oz., by the addition of water. To ascertain what quantity of spirit of any given strength will contain one equivalent of absolute alcohol. Add the overproof per centage of the given spirit to 100, as before; and with the number thus obtained divide 4062.183. The result gives in gallons the quantity equal to four equivalents (46 × 4). _Example._--How much spirit at 54 per cent. overproof is equal to 1 equivalent of absolute alcohol? Here, 54 + 100 = 154 and 4062.183 = 26.3778 galls., or 26 galls. 3 pts. -------- 154 which, divided by 4, gives 6 gallons, 4 pints, 15 oz. Suppose the spirit to be 60 overproof,-- 4062.183 {one-fourth of which is equal then ---------- = 25.388 gallons, {to 6 gallons, 2 pints, (100 + 60) {15-1/2 oz. This rule is founded on the following data. As a gallon of water weighs 10 lbs., it is obvious that the specific gravity of any liquid multiplied by 10 will give the weight of one gallon. The specific gravity of absolute alcohol is 0.793811; hence, the weight of one gallon will be 7.93811 lbs., and its strength is estimated at 75.25 overproof. 4 equivalents of alcohol = 46 × 4 = 184, and 23.17936 gallons × 7.93811 lbs. per gallon, also = 184.0003094. Hence it appears that 23.17936 gallons of absolute alcohol are equal to 4 equivalents. By adding the overproof per centage (75.25) to 100, and multiplying by the quantity (23.17936 gallons) we get the constant number 4062.183. The rule might have been calculated so as to show _at once_ the equivalent, without dividing by 4; but it would have required several more places of decimals; it will give the required quantity to a fraction of a fluid drachm. * * * * * PURIFICATION OF SPIRITS BY FILTRATION. BY MR. W. SCHAEFFER. Instead of resorting to repeated distillations for effecting the purification of spirits, Mr. Schaeffer proposes the use of a filter. In a suitable vessel, the form of which is not material, a filtering bed is constructed in the following manner:--On a false perforated bottom, covered with woollen or other fabric, a layer of about six inches of well-washed and very clean river sand is placed; next about twelve inches of granular charcoal, preferring that made from birch; on the charcoal is placed a layer of about one inch of wheat, boiled to such an extent as to cause it to swell as large as possible, and so that it will readily crush between the fingers. Above this is laid about ten inches of charcoal, then about one inch of broken oyster shells, and then about two inches more of charcoal, over which is placed a layer of woollen or other fabric, and over it a perforated partition, on to which the spirit to be filtered is poured; the filter is kept covered, and in order that the spirit may flow freely into the compartment of the filter below the filtering materials, a tube connects such lower compartment with the upper compartment of the filter, so that the air may pass freely between the lower and upper compartments of the filter. On each, of the several strata above described, it is desirable to place a layer of filtering paper. The charcoal suitable for the above purpose is not such as is obtained in the ordinary mode of preparation. It is placed in a retort or oven, and heated to a red heat until the blue flame has passed off, and the flame become red. The charcoal is then cooled in water, in which carbonate of potash has previously been dissolved, in the proportion of two ounces of carbonate to fifty gallons of water. The charcoal being deprived of the water is then reduced to a granular state, in which condition it is ready for use. * * * * * ON ESSENTIAL OIL OR OTTO OF LEMONS. BY JOHN S. COBB. (_Read before the Chemical Discussion Society._) I have recently made some experiments with oil of lemons, of which the following is a short account:-- Being constantly annoyed by the deposit and alteration in my essence of lemons, I have tried various methods of remedying the inconvenience. I first tried redistilling it, but besides the loss consequent on distilling small quantities, the flavor is thereby impaired. As the oil became brighter when heated, I anticipated that all its precipitable matter would be thrown down at a low temperature, and I applied a freezing mixture, keeping the oil at zero for some hours. No such change, however, took place. The plan which I ultimately decided upon as the best which I had arrived at, was to shake up the oil with a little boiling water, and to leave the water in the bottle; a mucilaginous preparation forms on the top of the water, and acquires a certain tenacity, so that the oil may be poured off to nearly the last, without disturbing the deposit. Perhaps cold water would answer equally well, were it carefully agitated with the oil and allowed some time to settle. A consideration of its origin and constitution, indeed, strengthens this opinion; for although lemon otto is obtained both by distillation and expression, that which is usually found in commerce is prepared by removing the "flavedo" of lemons with a rasp, and afterwards expressing it in a hair sack, allowing the filtrate to stand, that it may deposit some of its impurities, decanting and filtering. Thus obtained it still contains a certain amount of mucilaginous matter, which undergoes spontaneous decomposition, and thus (acting, in short, as a ferment) accelerates a similar change in the oil itself. If this view of its decomposition be a correct one, we evidently, in removing this matter by means of the water, get rid of a great source of alteration, and attain the same result as we should by distillation, without its waste or deterioration in flavor. I am, however, aware that some consider the deposit to be modified resin.[H] Some curious experiments of Saussure have shown that volatile oils absorb oxygen immediately they have been drawn from the plant, and are partially converted into a resin, which remains dissolved in the remainder of the essence. He remarked that this property of absorbing oxygen gradually increases, until a maximum is attained, and again diminishes after a certain lapse of time. In the oil of lavender this maximum remained only seven days, during each of which it absorbed seven times its volume of oxygen. In the oil of lemons the maximum was not attained until at the end of a month; it then lasted twenty-six days; during each of which it absorbed twice its volume of oxygen. The oil of turpentine did not attain the maximum for five months, it then remained for one month, during which time it absorbed daily its own volume of oxygen. It is the resin formed by the absorption of oxygen, and remaining dissolved in the essence, which destroys its original flavor. The oil of lemons presents a very great analogy with that of oil of turpentine, so far as regards its transformations, and its power of rotating a ray of polarized light. Authorities differ as regards this latter property. Pereira states that the oil of turpentine obtained by distillation with water, from American turpentine, has a molecular power of right-handed rotation, while the French oil of turpentine had a left-handed rotation. Oil of lemons rotates a ray of light to the right, but in France a distilled oil of lemons, sold as scouring drops for removing spots of grease, possesses quite the opposite power of rotation, and has lost all the original peculiar flavor of the oil. Oil of lemons combines with hydrochloric acid to form an artificial camphor, just in the same manner as does oil of turpentine, but its atom is only one half that of the oil of turpentine. The artificial camphor of oil of lemons is represented by the formula, C_{10}H_{8}HCl; the artificial camphor of oil of turpentine by C_{20}H_{16}HCl. According to M. Biot, the camphor formed by the oil of lemons does not exercise any action on polarized light, whilst the oil of lemons itself rotates a ray to the right. The camphor from oil of turpentine, on the contrary, does exercise on the polarized ray the same power as the oil possessed while in its isolated state, of rotating to the left. These molecular properties establish an essential difference between the oils of turpentine and lemons, and may serve to detect adulteration and fraud. It is also a curious fact, that from the decomposition of these artificial camphors by lime, volatile oils may be obtained by distillation, isomeric with the original oils from which the camphors were formed; but in neither case has the new product any action on polarized light. In conclusion, I would recommend that this oil, as well as all other essential oils, be kept in a cool, dark place, where no very great changes of temperature occur. * * * * * BENZOIC ACID, AND TESTS FOR ITS PURITY. BY W. BASTICK. Dr. Mohr's process for obtaining benzoic acid, which is adopted by the Prussian Pharmacopoeia, unquestionably has the reputation of being the best. According to this process, coarsely-powdered gum benzoin is to be strewed on the flat bottom of a round iron pot which has a diameter of nine inches, and a height of about two inches. On the surface of the pot is spread a piece of filtering paper, which is fastened to its rim by starch paste. A cylinder of very thick paper is attached by means of a string to the top of the iron pot. Heat is then applied by placing the pot on a plate covered with sand, over the mouth of a furnace. It must remain exposed to a gentle fire from four to six hours. Mohr usually obtains about an ounce and a half of benzoic acid from twelve ounces of gum benzoin by the first sublimation. As the gum is not exhausted by the first operation, it may be bruised when cold and again submitted to the action of heat, when a fresh portion of benzoic acid will sublime from it. This acid thus obtained, is not perfectly pure and white, and Mohr states that it is a question, in a medicinal and perfumery point of view, whether it is so valuable when perfectly pure, as when it contains a small portion of a fragrant volatile oil, which rises with it from the gum in the process of sublimation. The London Pharmacopoeia directs that it shall be prepared by sublimation, and does not prescribe that it shall be free from this oil, to which it principally owes its agreeable odor. By the second sublimation the whole of the benzoic acid is not volatilized. What remains in the resin may be separated by boiling it with caustic lime, and precipitating the acid from the resulting benzoate of lime with hydrochloric acid. Benzoic acid can be obtained also in the wet way, and the resin yields a greater product in this process than in the former; yet it has a less perfumery value, because it is free from the volatile oil which, as above stated, gives it its peculiar odor. The wet method devised by Scheele is as follows:--Make one ounce of freshly-burnt lime into a milk with from four to six ounces of hot water. To the milk of lime, four ounces of powdered benzoin and thirty ounces of water are to be added, and the mixture boiled for half an hour, and stirred during this operation, and afterwards strained through linen. The residue must be a second time boiled with twenty ounces of water and strained, and a third time with ten ounces; the fluid products must be mixed and evaporated to one-fourth of their volume, and sufficient hydrochloric acid added to render them slightly acid. When quite cold, the crystals are to be separated from the fluid by means of a linen strainer, upon which they are to be washed with cold water, and pressed, and then dissolved in hot distilled water, from which the crystals separate on cooling. When hydrochloric acid is added to a cold concentrated solution of the salts of benzoic acid, it is precipitated as a white powder. If the solution of the salts of this acid is too dilute and warm, none or only a portion of the benzoic acid will be separated. However, the weaker the solution is, and the more slowly it is cooled, the larger will be the crystals of this acid. In the preparation of this acid in the wet way, lime is to be preferred to every other base, because it forms insoluble combinations with the resinous constituents of the benzoin, and because it prevents the gum-resin from conglomerating into an adhesive mass, and also because an excess of this base is but slightly soluble. Stoltze has recommended a method by which all the acid can be removed from the benzoin:--The resin is to be dissolved in spirit, to which is to be added a watery solution of carbonate of soda, decomposed previously by alcohol. The spirit is to be removed by distillation, and the remaining watery solution, from which the resin has been separated by filtration, treated with dilute sulphuric acid, to precipitate the benzoic acid. This method gives the greatest quantity of acid, but is attended with a sacrifice of time and alcohol, which renders it in an economical point of view inferior to the above process of Scheele. It is so far valuable, that the total acid contents of the resin can be determined by it. Dr. Gregory considers the following process for obtaining benzoic acid the most productive. Dissolve benzoin in strong alcohol, by the aid of heat, and add to the solution, whilst hot, hydrochloric acid, in sufficient quantity to precipitate the resin. When the mixture is distilled, the benzoic acid passes over in the form of benzoic ether. Distillation must be continued as long as any ether passes over. Water added towards the end of the operation will facilitate the expulsion of the ether from the retort. When the ether ceases to pass over, the hot water in the retort is filtered, which deposits benzoic acid on cooling. The benzoic ether and all the distilled liquids are now treated with caustic potash until the ether is decomposed, and the solution is heated to boiling, and super-saturated with hydrochloric acid, which afterwards, on cooling, deposits, in crystals, benzoic acid. Benzoic acid, as it exists in the resin, is the natural production of the plant from which the resin is derived. It may also be produced artificially. Abel found that when cumole (C_{18}H_{12}) was treated with nitric acid, so dilute that no red vapors were evolved for several days, this hydro-carbon was converted into benzoic acid. Guckelberger has, by the oxidation of casein with peroxide of manganese and sulphuric acid, obtained as one of the products benzoic acid. Albumen, fibrin, and gelatin yielded similar results when treated as above. Wöhler has detected benzoic acid in Canadian castor, along with salicin. It is also formed by the oxidation of the volatile oil of bitter almonds. Benzoate of potash results when chloride of benzoyle is treated with caustic potash. Benzoic acid in the animal economy is converted into hippuric acid, which may by the action of acids, be reconverted into benzoic acid. Benzoic acid should be completely volatile, without leaving any ash or being carbonized when heated. When dissolved in warm water, to which a little nitric acid has been added, nitrate of silver and chloride of barium should produce no precipitates. Oxalate of potash should give no turbidity to an ammoniacal solution of this acid. When heated with an excess of caustic potash it should evolve no smell of ammonia, otherwise, it has been adulterated with sal ammoniac. In spirit, benzoic acid is easily soluble, and requires 200 parts of cold and 20 parts of boiling water to dissolve one part of it. * * * * * ON THE COLORING-MATTERS OF FLOWERS. BY FREMY AND CLOEZ. Chemists possess only a very incomplete knowledge of the coloring matters of flowers. Their investigation involves difficulties which cannot be mistaken. The matters which color flowers are uncrystallized; they frequently change by the action of the reagents employed for their preparation; and, also, very brilliantly-colored flowers owe their color to very small quantities of coloring matter. On the nature of the coloring matters of flowers several opinions have been expressed. Some observers have assumed that flowers owe their color to only two coloring matters, one of which is termed anthocyan, and the other anthoxanthine. Others will find a relation between the green coloring of leaves, the chlorophylle, and the coloring matters of flowers. They support their opinion generally on the results of the elementary analysis of those different bodies; but all chemists know that chlorophylle has not yet been prepared in a pure condition. Probably, it retains various quantities of fatty and albuminous bodies. Further, the coloring matters of flowers are scarcely known, so that it is impossible to establish relations supported by the necessarily uncertain composition of impure bodies. Some time since the blue color of flowers was ascribed to the presence of indigo; but Chevreul has shown, in a certain way, that the blue substance of flowers is always reddened by acids; and that with indigo it is quite different, which, as is known, retains its blue color even when the strongest acids are allowed to act on it. It is thus seen that the coloring matters of flowers have heretofore only in a superficial manner been examined, and that it is important to again undertake their complete examination, as these bodies are interesting to the chemist, because they are employed as reagents in the laboratory for the recognition of alkalies; and by an improved knowledge of them the florist might find the way by which he could give to cultivated flowers various colors. We have believed that before undertaking their elementary analysis, methods must be carefully sought for which can be followed for the obtainment of the coloring matters of flowers, and that it should be proved whether these substances are to be considered as independent bodies, or whether they proceed from one and the same matter, which is changed in various ways by the juices of the plant. We now publish the results of our first investigations. _Blue Coloring Matter of Flowers (Cyanine)._--The blue coloring matter of flowers we propose to call cyanine. To obtain this substance we treat the petals of _Centauria cyanus_, _Viola odorata_, or _Iris pseudacorus_, with boiling alcohol, by which the flowers are decolorized; and the liquid acquires immediately a fine blue color. If the coloring matter is allowed to remain some time in contact with alcohol, it is perceived that the blue of the liquid gradually disappears, and soon a yellow brown coloration takes its place. The coloring matter has in this case suffered an actual reduction by the prolonged action of the alcohol, but it will again assume its original color when the alcohol is allowed to evaporate in the air. Nevertheless, the alcohol must not be allowed to remain in contact too long with the coloring matter, because the alcoholic extract will not then again assume its blue coloration by the action of oxygen. The residue remaining from the evaporation of the alcohol is treated with water, which separates a fatty and resinous substance. The watery solution which contains the coloring matter is then precipitated by neutral acetate of lead. The precipitate, which possesses a beautiful green color, can be washed with plenty of water, and then decomposed with sulphuretted hydrogen; the coloring matter passes into the watery solution, which is carefully evaporated in a water-bath; the residue is again dissolved in absolute alcohol; and lastly, the alcoholic solution is mixed with ether, which precipitates the cyanine in the form of blue flocks. Cyanine is uncrystallizable, soluble in water and alcohol, insoluble in ether; acids, and acid salts color it immediately red; by alkalies it is, as known, colored green. Cyanine appears to behave as an acid, at least it forms with lime, baryta, strontia, oxide of lead, &c., green compounds insoluble in water. Bodies absorbing oxygen, as sulphurous acid, phosphorous acid, and alcohols, decolorize it; under the influence of oxygen its color is restored. We must here mention that Moroz has prepared a beautiful blue substance from _Centauria cyanus_ by treatment with absolute alcohol. _Rose-red Coloring Matter._--We have employed alcohol to extract the substance which colors rose-red certain dahlias, roses, poeonias, &c. For the procuration of this coloring matter the method pursued is exactly as that for the preparation of cyanine. By an attentive comparison of the properties of this coloring matter with those of cyanine, we have found that the rose-red coloring matter is the same as the blue, or at least results from a modification of the same independent principle. It appears in the rose-red modification, when the juice of the plant, with which it exists in contact, possesses an acid reaction. We have always observed this acid reaction in the juices of plants with red or rose-red coloration, while the blue juices of plants have always exhibited an alkaline reaction. We have exposed most of the rose-red or red-colored flowers which are cultivated in the Paris Museum to the influence of alkalies, and have seen that they first become blue and then green by their action. It is often perceived that certain rose-red flowers, as those of the _Mallow_, and in particular those of the _Hibiscus Syriacus_, acquire by fading a blue and then a green coloration, which change, as we have found, depends on the decomposition of an organic nitrogenous substance, which is found very frequently in the petals. This body generates as it decomposes ammonia, which communicates to the flowers the blue or green color. By action of weak acids, the petals can be restored to their rose-red color. The alteration of color of certain rose-red flowers can also be observed when the petals are very rapidly dried, for example, in _vacuo_, by which it cannot be easily assumed that a nitrogenous body has undergone decomposition to the evolution of ammonia. But, before all things, it must be mentioned that in this case the modification of color passes into violet, and never arrives at green; and, further, that it is always accompanied with the evolution of carbonic acid, which we have detected by a direct experiment. Petals which were before rose-red, and have become violet by slight drying, evolve carbonic acid, and on that account it may be assumed that the rose-red color is produced in the petals by this carbonic acid, and that by its expulsion the petals assume the blue color, by which the flowers with neutral juices are characterized. We believe that we are able to speak with certainty that flowers with a rose-red, violet, or blue color, owe their coloration to one and the same substance, but which is modified in various ways by the influence of the juices of plants. Scarlet-red flowers also contain cyanine reddened by an acid, but in such cases this substance is mixed with a yellow coloring matter which we will now describe. _Yellow Coloring Matter._--The simplest experiments show that no analogy exists between the substance which colors flowers yellow and that of which we have already spoken. The agents which generate so easily with cyanine, the rose-red, violet, or green coloration, cannot in any case impart these colors to the yellow substance obtained from flowers. By the examination of the various yellow-colored flowers, we have ascertained that they owe their coloration to two substances, which differ from one another in their properties, and appear not to be derived from the same independent principle. One is completely insoluble in water, which we have termed xanthine, a name which Runge has given to a yellow matter from madder. As this name has not been accepted in science, we have employed it to denote one of the coloring matters of yellow flowers. The other substance is very soluble in water, and is by us termed xantheine. _Xanthine, or the Yellow Coloring Matter insoluble in water._--We have prepared this coloring matter from many yellow flowers, but chiefly from _Helianthus annuus_. To obtain it we treat the flowers with boiling absolute alcohol, which dissolves the coloring matter in the heat, and by cooling almost completely allows it again to precipitate. The yellow deposit which is obtained in this way, is not pure xanthine, as it contains a rather considerable quantity of oil. To separate this oil we have recourse to a moderate saponification; thus, we heat the yellow precipitate with a small quantity of alkali to saponify the fatty body mixed with the xanthine, which even contains the xanthine dissolved. As the coloring matter is soluble in the soap solution, we do not treat the mass with water, but decompose it with an acid which isolates the xanthine and the fatty acids resulting from the saponification. This precipitate we treat with cold alcohol, which leaves behind the fatty acids, and dissolves the xanthine. This substance is a fine yellow color, insoluble in water, but soluble in alcohol and ether, which are thereby colored golden yellow. It appears to be uncrystallizable, and possesses the general properties of resins. Xanthine, in combination with cyanine, modified by the various juices of plants, communicates in variable proportions orange-yellow, scarlet-red, and red colors to flowers. _Xantheine, or the Coloring Matter soluble in water._--By the preparation of the substance which colors yellow certain dahlias, it is at once perceived that it has no analogy to xanthine. The latter is as known insoluble in water, while the coloring matter under consideration is readily soluble in water. To obtain the xanthine we treat the petals of yellow flowering dahlias with alcohol, which quickly dissolves the yellow coloring matter, besides the fat and resin. The solution is evaporated to dryness, and the residue treated with water, whereby the fat and resin are separated. The water is again evaporated to dryness, and the residue treated with absolute alcohol. The resulting solution diluted with water is mixed with neutral acetate of lead, which precipitates the coloring matters. The lead precipitate is then decomposed with sulphuric acid, upon which the xantheine which remains dissolved in the water is purified by alcohol. Xantheine is soluble in water, alcohol, and ether, but crystallizes from none of these solutions. Alkalies color it intensely brown. Its power of coloration is considerable. It dyes various fabrics of a yellow tone, which is without brilliancy. Acids again destroy the brown coloration produced by alkalies. Xantheine combines with most metallic bases, and forms therewith yellow or brown insoluble lakes. The facts here related agree with all which has been previously observed regarding the coloring matters of flowers. It is known that blue flowers can become red, and even white, where their coloring matter is destroyed, but never yellow--and _vice versâ_. These three coloring matters can generate the colors either alone or by admixture, which are seen in flowers; but whether they are the only matters which color flowers, we are at present unable to determine.--_Journal de Pharmacie._ * * * * * IMPROVED PROCESS FOR BLEACHING BEES'-WAX AND THE FATTY ACIDS. BY MR. G.F. WILSON. This improved process consists of two parts:--1st, the application of highly-heated steam to heat the fatty matters under treatment, by which means the requisite heat for melting these substances is obtained, and at the same time the atmosphere is thereby excluded; the heated steam so applied in its passage off, carries with it the offensive smells given off by the fatty matters, and being made to traverse a pipe or passage up or along which gaseous chlorine is allowed to flow, a complete disinfection of the offensive products is thereby effected. 2dly, the treating of bees'-wax in a mixture of hard acid fat and bees'-wax, with compounds of chlorine and oxygen, preferring to employ that disengaged from chlorate of potash by treating it with sulphuric acid. For this purpose, Mr. Wilson takes at the rate, say, of a ton of yellow bees'-wax, and melts and boils it up with free steam for about half an hour. It is then allowed to stand a short time, and is then decanted into another vessel provided with a steam-pipe to emit free steam; about 20 lbs. of chlorate of potash is added, and the steam turned on; 80 lbs. of sulphuric acid, diluted with a like weight of water, is then gradually added. The matters are allowed to stand for a short time, and are then decanted into another vessel, and again boiled up with free steam, and treated with a like quantity of diluted sulphuric acid. The bees'-wax is then decanted into a receiver, and is ready for use. The bees'-wax may, before undergoing these processes, be combined and boiled up with a hard fatty acid, and then treated as above described. * * * * * CHEMICAL EXAMINATION OF NAPLES SOAP. A. Faiszt has submitted this celebrated shaving soap to analysis. He states that it is made by saponifying mutton fat with lime, and then separating the fatty acids from the soap thus formed, by means of a mineral acid. These fatty acids are afterwards combined with ordinary caustic potash to produce the Naples soap. He found that 100 parts of this soap contained Parts. Fatty acids, 57.14 Potash combined with the fatty acids, 10.39 Sulphate of potash, chloride of potassium, with a trace of carbonate of potash, 4.22 Silica, &c., 0.46 Water, 27.68 ----- 99.89 _Gewerbeblatt aus Wurttemberg._ * * * * * MANUFACTURE OF SOAP. The removal of the duty from soap, and the consequent emancipation of this branch of industry from the tender mercies of the Excise, has given a fresh impetus to the manufacture of this important article of daily use, and enabled some processes to be practically carried out in England, which, previous to the removal of the duty, could not be adopted in this part of her Majesty's dominions. It will doubtless appear strange to those unacquainted with the circumstances, that owing to the mode of levying the duty by admeasurement, and not by actual weight, the maker of a particular kind of soap was debarred the privilege of manufacturing in this country. Fortunately for him, the manufacture of soap being free from all Excise restrictions in Ireland, he was enabled to carry out his process in the sister kingdom, whence it was exported to England, and admitted here on payment of the Customs' duty, which was the same as the Excise duty on its manufacture here. All this roundabout method of doing business is now done away with, and no restriction now exists to mar the peace of the soap manufacturer. Amongst various new processes lately introduced is that of Mr. H.C. Jennings, which is practically carried out in the following manner:-- Combine 1000 lbs. of stearic or margaric acid, as free from elaine or oleine as possible, or palmatine, or any vegetable or animal stearine or margarine, at the temperature of 212° Fahr., with a solution of bicarbonate of potash or soda, specific gravity 1500. Constantly stir or mix until an intimate combination is obtained, and that the elements will not part when tried upon glass or any other similar substance. When the mass is cooled down to about 60° Fahr. add one pound per cent. of liquor ammoniæ, specific gravity 880, and one pound per cent. of strongest solution of caustic potash; these are to be added gradually, and fully mixed or stirred until perfectly combined. Dissolve 15 to 18 pounds per cent. of common resin of commerce, by boiling it with a solution of subcarbonate of potash and common soda of commerce, in equal parts, as much as will give the solution a specific gravity of about 1800, when boiling hot. Mix these perfectly with the above-mentioned stearic or margaric acids, and carbonated alkali; then add a strong solution of caustic potash or soda, until a perfect saponification is produced. The dose of caustic alkali will much depend upon the purity of the stearine or margarine employed. The separation is now effected by using common salt, or sulphate of soda, &c., as is known and practised by soap manufacturers. If the soap intended to be produced is to be colorless, no resin must be employed, and a larger dose of liquor ammoniæ and caustic alkali must be used, according to the dryness of the stearine matters to be operated upon. * * * * * A SIMPLE AND CERTAIN METHOD TO DETERMINE THE COMMERCIAL VALUE OF SOAP. BY DR. ALEXANDER MÜLLER. In consequence of the ceremonious process by which the fatty acids are determined in one portion of the soap, and the alkali by the incineration of another, I consider the following method is not unworthy of publication, because it appears to afford quicker and more correct results by reason of the greater simplicity of the manipulation. It is available principally for soda soaps, which are the most common; but it may be also employed with corresponding alterations for soaps which have other bases. A piece of soap weighing two or three grammes is dissolved in a tared beaker glass of about 160 cubic centimetres capacity with 80 to 100 cubic centimetres of water, by heat, in a water-bath, and then three or four times the quantity of diluted sulphuric acid or as much as is necessary to decompose the soap, added from a burette. When, after repeated agitation, the fatty acids have separated in a transparent clear stratum from the aqueous solution, it is allowed to cool, and then the contents of the beaker glass are placed in a moistened filter, which has been previously dried at 212° Fahr. and weighed. The contents of the filter are washed until their acid reaction disappears. In the meanwhile the beaker glass is placed in a steam-bath, so that, it being already dry, may support the washed and partly dry filter, which is laid on the mouth of the glass as if it were in the funnel. The fatty acids soon pass through the paper, and for the most part flow ultimately to the bottom of the beaker glass; the increase of weight of which, after cooling, and the subtraction of the weight of the filter, gives the quantity of fatty acids present in the soap. A second drying and weighing is not necessary, if on the cold sides of the interior of the glass no damp is to be observed, which is occasioned by a trace of water still present. If the quantity of oxide of iron added to marble the soap is considerable, it may be easily found by incinerating the filter and determining the weight of the residue. The fluid runs from the fatty acids on the filter, which, with the washings, has been preserved in a sufficiently large beaker glass, is colored with tincture of litmus, and decomposed with a test alkaline solution until the blue color appears. The difference of the quantity of alkali required to neutralize the sulphuric acid, and the quantity of sulphuric acid used in the first instance, allows a calculation to be made as to the quantity of effective alkali in the soap, for example:-- 23.86 grms. of soap (partly cocoa-nut oil soap). 17.95 " fatty acids with filter. 04.44 " filter. ----- 13.51 grms. of hydrates of fatty acids = 56.62 per cent. 28.00 cub. cent. of the diluted sulphuric acid applied for the decomposition of the soap, of which 100 cub. cent. represent 2982 grms. of carbonate of soda. 17.55 cub. cent. of alkaline fluid, which were used for the saturation of the above acid, and of which 100 cub. cent. saturate an equal quantity of that acid. ---- 10.45 cub. cent. of the sulphuric necessary for the alkali contained in the soap, representing 0.1823 grms. of soda = 7.64 per cent. A determination of the alkali as a sulphate afforded in another portion of soap 9.57 per cent. of soda, because the sulphate of soda and chloride of sodium present in the soap gave up their alkali. The alkaline fluid applied by me was a saccharine solution of lime, which can be naturally replaced by a solution of soda, and must be if the chloride of sodium and sulphate of soda mixed with the soap shall be determined in the following way:-- The fluid again exactly neutralized with alkali is evaporated to dryness, and the residue gently heated to redness. As in the above manipulation, the fluid was not heated to the boiling point, the original chloride of sodium and sulphate of soda are contained in the weighed residue, besides the soda of the soap and that which has been added with the sulphuric acid, forming sulphate of soda. A second exposure to a red heat with sulphuric acid converts the whole residue into sulphate of soda, and from the increase of weight, by a comparison of the equivalents of NaCl and NaO, SO_{3} the quantity of the former may be decided. According to the equivalents which Kopp furnished in 1850, the increase of weight to the chloride of sodium is as 1:4.68. The original sulphate of soda must be, lastly, found by the subtraction of the same salt formed plus the calculated chloride of sodium from the first heated residue. In practice, it is seldom necessary to proceed with the determination of the chloride of sodium and sulphate of soda, except with stirred and cocoa-nut oil soaps; certainly less of the truth is seen if, after the above determination of the fatty acids and the effective alkali, the absent per centage of water is introduced in the calculation, than if the water is reckoned, which is never completely evolved from soap, even technically prepared at 302° Fahr., and another determination made of the fatty acids or alkali _en bloc_ the fatty acids, or even the alkaline contents. The method here given partakes of the usual imperfections, that the fatty acids as well as the unsaponified soap are equally estimated, and the mixed hydrate or carbonate of the alkali as well as the combined alkali. The presence of the carbonate can be easily recognized by the foaming of the soap solution, upon the addition of the sulphuric acid. These imperfections, however, are of little importance. It must be granted that the minutely correct determination of the constitution of soap must be always yielded up to those who are technically conversant with this department of chemistry, the estimation of free alkali and unchanged fat excluded in, at least, by certain ages of the soap. Further, a considerable excess of one or another ingredient soon betrays itself by a corresponding departure in the soap of the characteristic properties of a good product, and a small excess can be judged sufficiently exact from the proportion of the alkali, which, supposing soda present, should not amount to more than 13 per cent. with a pure cocoa-nut oil soap, not less than 11.5 per cent. with a tallow soap; but with palm oil and mixed soaps the one or the other limit approximates.--_Journal für Praktische Chemie._ * * * * * ON THE NATURAL FATS. BY DR. CHARLES LÖWIG. The fats which exist in nature can be divided into the general and the special; the former exist in almost all plants and parts of plants; the latter includes only some vegetable substances, as _laurostearine_, _myristicine_, and _palmatine_. The consistence of fats of the general kind depend upon the proportions of margarine, stearine, and oleine contained in them. The former preponderate in the solid fats (butter, lard, and tallow); and the latter in the fluid ones or oils. According as an oil contains oleic acid or olinic acid, it is termed a fatty or drying oil. To the class of fatty oils belong olive, almond, hazel-nut, beech, rape oils, &c.; to that of drying oils, linseed, nut, hemp, poppy, grape-seed, oils, &c.; which are used for varnishes. In the vegetable kingdom the fats are chiefly in the seeds and in their coverings, seldom in the perispemium (poppy), and in the fleshy substance surrounding the seed (olive). The fat in the seed is mostly enclosed in cells with a proteine compound. In the animal kingdom certain parts of the body are quite filled with fat-cells, particularly under the skin (_Paniculus adiposus_), in the cavities of the abdomen, in the so-called _omentum_, in the kidneys and the tubulated canals of the bones. Fat is also enclosed in cells (fatty globules) in milk. It is established, without a doubt, that a greater portion of the fat which exists in the animal kingdom originates from the vegetable kingdom, for it is introduced into the body cotemporaneously with the proteine compounds of that kingdom. A portion of the fat as well as wax is formed in the animal organismus, as shown by a number of observations, and in most cases it is unquestionable that the non-nitrogenous nutriments, as starch, serve for the formation of fat by a process of deoxidation; nevertheless, the formation of fat in the animal body appears only to take place when the substances containing starch enter the body simultaneously with fat. If the fat existing in the animal body is contained in cellular tissue, its separation may be simply effected by placing the incised tissue in hot water. The cells burst and the fat collects itself on the surface of the water. If vegetable substances contain fat in large quantity, as, for example, seeds, it may be obtained by expression. The dried seeds are bruised and expressed between either cold or hot metallic plates. Olives are laid in heaps before expression; when they begin to ferment, they can be completely expressed. If animal and vegetable substances contain only a little fat, it must be extracted by ether. In the pure condition the fats are mostly odorless and tasteless; when they possess an odor, it arises mostly from the presence of small quantities of volatile fatty acids, as butyric acid, capric acid, &c.; which becomes free through the decomposition of their oxide of glycyl combinations. This ensues by the presence of water and air through a kind of fermentation, and as it appears, by the presence of a nitrogenous substance. The fats are insoluble in water, and, with the exception of castor oil, are taken up by cold alcohol in very small quantities, however, more in proportion as they contain oleine. In boiling alcohol they are dissolved, but are, for the most part, again separated on cooling, particularly those rich in stearine. All fats are taken up by ether but those containing stearine in the smallest quantity. Their specific gravities fluctuate between .91 and .93. When heated, fats assume a dark color, and boil between 482° and 572° Fahr., but the boiling-point continuously rises, while an uninterrupted decomposition proceeds. From oxide of glycyl ensues acroline; oleic acid affords a fatty acid, and among the decomposition products of fats containing stearine and margarine are found pure margaric acid, and, at the same time, some hydro-carbons are formed. When exposed quickly to a high temperature, fats are completely decomposed. (Oil gas.) In closed vessels the pure fats undergo no change, but, placed in thin layers in the air, the fats containing oleine and oline rapidly absorb oxygen under the strong evolution of heat, which will inflame porous bodies, as cotton wool. The purer the fats are the more quickly their oxidation results. When the fats contain slimy materials, these latter can be destroyed with a little oxide of lead and water. (Preparation for the application of varnishes.) The action of nitric acid, nitrous acid, chlorine, sulphuric acid, &c., on fats is the same as that of these bodies on the fatty acids. The fatty oils dissolve sulphur in the heat which is again partly precipitated on cooling. When sulphur is heated with fatty oils, namely, with linseed oil, it dissolves by degrees, and a thick dark mass is formed, the so-called balsam of sulphur. By raising the heat, a violent reaction ensues under the evolution of sulphuretted hydrogen, and, at the same time, an oil resembling oil of garlic volatilizes. This oil begins to boil at 160° Fahr., but its boiling-point rises continually. * * * * * PERFUMES AS PREVENTIVES OF MOULDINESS. An interesting paper on this subject has been published by Dr. Macculloch. We presume our readers are aware that mouldiness is occasioned by the growth of minute vegetables. Ink, paste, leather, and seeds, are the substances that most frequently suffer from it. The effect of cloves in preserving ink is well known; any of the essential oils answer equally well. Leather may be kept free from mould by the same substances. Thus Russian leather, which is perfumed with the tar of birch, never becomes mouldy; indeed it prevents it from occurring in other bodies. A few drops of any essential oil are sufficient also to keep books entirely free from it. For harness, oil of turpentine is recommended. Bookbinders, in general, employ alum for preserving their paste; but mould frequently forms on it. Shoemakers' resin is sometimes also used for the same purpose; but it is less effectual than oil of turpentine. The best preventives, however, are the essential oils, even in small quantity, as those of peppermint, anise, or cassia, by which paste may be kept almost any length of time; indeed, it has, in this way, been preserved for years. The paste recommended by Dr. Macculloch is made in the usual way, with flour, some brown sugar, and a little corrosive sublimate; the sugar keeping it flexible when dry, and the sublimate preventing it from fermenting, and from being attacked by insects. After it is made, a few drops of any of the essential oils are added. Paste made in this way dries when exposed to the air, and may be used merely by wetting it. If required to be kept always ready for use, it ought to be put into covered pots. Seeds may also be preserved by the essential oils; and this is of great consequence, when they are to be sent to a distance. Of course moisture must be excluded as much as possible, as the oils or ottos prevent only the bad effects of mould. * * * * * FUSEL OIL. BY W. BASTICK. This organic compound was first discovered by Scheele, as one of the distillation products of the wort obtained from the fermentation of potatoes. It has been subsequently examined by Pelletier, Dumas, Cahours, and others. It is generally now termed the hydrate of the oxide of amyl, from amyl being supposed to be its base or radical, as cyanogen is regarded to be the radical of another series of compounds. It passes over towards the termination of the distillation process in a white turbid fluid, which consists of a watery and alcoholic solution of the fusel oil. The crude oil, consisting of about one-half of its weight of alcohol and water, may be purified, being shaken with water and redistilled, with the previous addition of chloride of calcium. When the temperature of the contents of retort reaches 296° Fahr., pure fusel oil distils over. Fusel oil is a colorless oily fluid, which possesses at first not an unagreeable odor, but at last is very disgusting, producing oppression at the chest and exciting cough. It has a sharp hot taste, and burns with a white blue flame. It boils at 296° Fahr., and at temperature of -4° Fahr. it becomes solid, and forms crystals. Its specific gravity at 59° Fahr. is 0.8124, and its formula C_{10}H_{12}O_{2}. On paper it produces a greasy stain, which disappears by heat, and when exposed to the action of the air it acquires an acid reaction. Fusel oil is slightly soluble in water, to which it imparts its odor; and soluble in all proportions in alcohol, ether, volatile and fixed oils, and acetic acid. It dissolves phosphorus, sulphur, and iodine without any noticeable change, and also mixes with caustic soda and potash. It rapidly absorbs hydrochloric acid, with the disengagement of heat. When mixed with concentrated sulphuric acid, the mixture becomes of a violet-red color, and bisulphate of amyloxide is formed. Nitric acid and chlorine decompose it. By its distillation with anhydrous phosphoric acid, a fluid, oily combination of hydrogen and carbon results. By oxidation with bichromate of potash and sulphuric acid, fusel oil yields valerianic acid, which is used in medicine, and apple-oil, employed as a flavoring ingredient in confectionery. * * * * * ESSENCE OF PINE-APPLE. BY W. BASTICK. The above essence is, as already known, butyric ether more or less diluted with alcohol; to obtain which pure, on the large scale and economically, the following process is recommended:-- Dissolve 6 lbs. of sugar and half an ounce of tartaric acid, in 26 lbs. of boiling water. Let the solution stand for several days; then add 8 ounces of putrid cheese broken up with 3 lbs. of skimmed and curdled sour milk and 3 lbs. of levigated chalk. The mixture should be kept and stirred daily in a warm place, at the temperature of about 92° Fahr., as long as gas is evolved, which is generally the case for five or six weeks. The liquid thus obtained, is mixed with an equal volume of cold water, and 8 lbs. of crystallized carbonate of soda, previously dissolved in water, added. It is then filtered from the precipitated carbonate of lime; the filtrate is to be evaporated down to 10 lbs., when 5-1/2 lbs. of sulphuric acid, previously diluted with an equal weight of water, are to be carefully added. The butyric acid, which separates on the surface of the liquid as a dark-colored oil, is to be removed, and the rest of the liquid distilled; the distillate is now neutralized with carbonate of soda, and the butyric acid separated as before, with sulphuric acid. The whole of the crude acid is to be rectified with the addition of an ounce of sulphuric acid to every pound. The distillate is then saturated with fused chloride of calcium, and redistilled. The product will be about 28 ounces of pure butyric acid. To prepare the butyric acid or essence of pine-apple, from this acid proceed as follows:--Mix, by weight, three parts of butyric acid with six parts of alcohol, and two parts of sulphuric acid in a retort, and submit the whole, with a sufficient heat, to a gentle distillation, until the fluid which passes over ceases to emit a fruity odor. By treating the distillate with chloride of calcium, and by its redistillation, the pure ether may be obtained. The boiling-point of butyric ether is 238° Fahr. Its specific gravity, 0.904, and its formula, C_{12}H_{12}O_{4}, or C_{4}H_{5}O + C_{8}H_{7}O_{3}. Bensch's process, above described, for the production of butyric acid, affords a remarkable exemplification of the extraordinary transformations that organic bodies undergo in contact with ferment, or by catalytic action. When cane sugar is treated with tartaric acid, especially under the influence of heat, it is converted into grape sugar. This grape sugar, in the presence of decomposing nitrogenous substances, such as cheese, is transformed in the first instance into lactic acid, which combines with the lime of the chalk. The acid of the lactate of lime, thus produced, is by the further influence of the ferment changed into butyric acid. Hence, butyrate of lime is the final result of the catalytic action in the process we have here recommended. * * * * * PREPARATION OF CRUDE PELARGONATE OF ETHYL-OXIDE (ESSENCE OF QUINCE.) BY DR. R. WAGNER. It has been believed, until the most recent period, that the peel of quinces contains oenanthylate of ethyl-oxide. New researches, however, have led to the supposition that the odorous principle of quinces is derived from the ether of pelargonic acid. In my last research on the action of nitric acid on oil of rue, I found that besides the fatty acids, which Gerhardt had already discovered, pelargonic acid is formed. This process may be advantageously employed for the preparation of crude pelargonate of ethyl-oxide, which, on account of its extremely agreeable odor, may be applied as a fruit essence equally with those prepared by Dobereiner, Hofmann, and Fehling. For the preparation of the liquid, which can be named the essence of quince, oil of rue is treated with double its quantity of very diluted nitric acid, and the mixture heated until it begins to boil. After some time two layers are to be observed in the liquid: the upper one is brownish, and the lower one consists of the products of the oxidation of oil of rue and the excess of nitric acid. The lower layer is freed from the greater part of its nitric acid by evaporation in a chloride of zinc bath. The white flocks frequently found in the acid liquid, which are probably fatty acids, are separated by filtration. The filtrate is mixed with spirit, and long digested in a gentle heat, by which a fluid is formed, which has the agreeable odor of quince in the highest degree, and may be purified by distillation. The spirituous solution of pelargonic ether may also be profitably prepared from oleic acid, according to Gottlieb's method.--_Journal für Praktische Chemie._ * * * * * PREPARATION OF RUM-ETHER. Take of black oxide of manganese, of sulphuric acid, each twelve pounds; of alcohol, twenty-six pounds; of strong acetic acid, ten pounds. Mix, and distil twelve pints. The ether, as above prepared, is an article of commerce in Austria, being the body to which rum owes its peculiar flavor.--_Austrian Journal of Pharmacy._ * * * * * ARTIFICIAL FRUIT ESSENCES. BY FEHLING. _Pine-apple Oil_ is a solution of one part of butyric ether, in eight or ten parts of alcohol. For the preparation of this ether, pure butyric acid must be first obtained by the fermentation of sugar, according to the method of Bensch. One pound of this acid is dissolved in one pound of strong alcohol, and mixed with from a quarter to half an ounce of sulphuric acid; the mixture is heated for some minutes, whereby the butyric ether separates as a light stratum. The whole is mixed with half its volume of water, and the upper stratum then removed; the heavy fluid is distilled, by which more butyric ether is obtained. The distillate and the removed oily liquid are shaken with a little water, the lighter portion of the liquid removed, which at last, by being shaken with water and a little soda, is freed from adhering acid. For the preparation of the essence of pine-apple, one pound of this ether is dissolved in 8 or 10 pounds of alcohol. 20 or 25 drops of this solution is sufficient to give to one pound of sugar a strong taste of pine-apple, if a little citric or tartaric acid has been added. _Pear-oil._--This is an alcoholic solution of acetate of amyloxide, and acetate of ethyloxide. For its preparation, one pound of glacial acetic acid is added to an equal weight of fusel-oil (which has been prepared by being washed with soda and water, and then distilled at a temperature between 254° and 284° Fahr.), and mixed with half a pound of sulphuric acid. The mixture is digested for some hours at a temperature of 254°, by which means acetate of amyloxide separates, particularly on the addition of some water. The crude acetate of amyloxide obtained by separation, and by the distillation of the liquid to which the water has been added, is finally purified by being washed with soda and water. Fifteen parts of acetate of amyloxide are dissolved with half a part of acetic ether in 100 or 120 parts of alcohol; this is the essence of pear, which, when employed to flavor sugar or syrup, to which a little citric or tartaric acid has been added, affords the flavor of bergamot pears, and a fruity, refreshing taste. _Apple-oil_ is an alcoholic solution of valerianate of amyloxide. It is obtained impure, as a by product, when for the preparation of valerianic acid, fusel-oil is distilled with bichromate of potash and sulphuric acid. It is better prepared in the following manner:--For the preparation of valerianic acid, 1 part of fusel-oil is mixed gradually with 3 parts of sulphuric acid, and 2 parts of water added. A solution of 2-1/4 parts of bichromate of potash, with 4-1/2 parts of water, is heated in a tubulated retort, and into this fluid the former mixture is gradually poured, so that the ebullition is not too rapid. The distillate is saturated with carbonate of soda, and warmed, when a solution of 3 parts of crystallized carbonate of soda, 2 parts of strong sulphuric acid, diluted with an equal quantity of water, are added. The valerianic acid separates as an oily stratum. One part, by weight, of pure fusel-oil is carefully mixed with an equal weight of sulphuric acid. The cold solution is added to 1-1/4 parts of the above valerianic acid; the mixture is warmed for some minutes (not too long or too much) in a water-bath, and then mixed with a little water, by which means the impure valerianate of amyloxide separates, which is washed with water and carbonate of soda. For use as an essence of apples, one part of this valerianate of amyloxide is dissolved in 6 or 8 parts of alcohol. * * * * * VOLATILE OIL OF GAULTHERIA PROCUMBENS. BY W. BASTICK. The chemical history of this oil is one of great importance and interest, affording, as it does, one of the examples where the progress of modern chemistry has succeeded in producing artificially a complex organic body, previously only known as the result of vital force. This volatile oil is obtained from the winter-green, an American shrub of the heath family, by distillation. When this plant is distilled, at first an oil passes over which consists of C_{10}H_{8}, but when the temperature reaches 464° Fahr., a pure oil distils into the receiver. Therefore the essential oil of this plant, like many others, consists of two portions--one a hydro-carbon, and the other an oxygenated compound; this latter is the chief constituent of the oil, and that which is of so much chemical interest, from the fact that it has been artificially prepared. It is termed, when thus prepared, the spiroylate of the oxide of methyl, and is obtained when two parts of wood spirit, one and a half parts of spiroylic acid, and one part of sulphuric acid are distilled together. It is a colorless liquid, of an agreeable aromatic odor and taste; it dissolves slightly in water, but in all proportions in ether and alcohol; it boils between 411° and 435° Fahr., and has a specific gravity of 1.173. This compound expels carbonic acid from its combinations, and forms a series of salts, which contain one atom of base and one atom of spiroylate of the oxide of methyl. It behaves therefore as a conjugate acid. Its formula is C_{14}H_{5}O_{5} + C_{2}H_{3}O. The spiroylic acid may be separated from the natural oil by treating it with a concentrated solution of caustic potash at a temperature of 113° Fahr., when wood spirit is formed and evaporates, and the solution contains the spiroylate of potash, from which, when decomposed with sulphuric acid, the spiroylic acid separates and subsides in the fluid. Spiroylic acid is also formed by the oxidation of spiroyligenic acid, and when saligenin, salicin, courmacin, or indigo, is heated with caustic potash. * * * * * ON THE APPLICATION OF ORGANIC CHEMISTRY TO PERFUMERY. BY DR. A.W. HOFMANN, _Professor to the Royal College of Chemistry, London_. Cahours' excellent researches concerning the essential oil of _Gaultheria procumbens_ (a North American plant of the natural order of the Ericinæ of Jussieu), which admits of so many applications in perfumery,[I] have opened a new field in this branch of industry. The introduction of this oil among compound ethers must necessarily direct the attention of perfumers[J] towards this important branch of compounds, the number of which is daily increasing by the labors of those who apply themselves to organic chemistry. The striking similarity of the smell of these ethers to that of fruit had not escaped the observation of chemistry; however, it was reserved to practical men to discover by which choice and combinations it might be possible to imitate the scent of peculiar fruits to such a nicety, that makes it probable that the scent of the fruit is owing to a natural combination identical to that produced by art; so much so, as to enable the chemist to produce from fruits the said combinations, provided he could have at his disposal a sufficient quantity to operate upon. The manufacture of artificial aromatic oils for the purpose of perfumery[K] is, of course, a recent branch of industry; nevertheless, it has already fallen into the hands of several distillers, who produce sufficient quantity to supply the trade; a fact, which has not escaped the observation of the Jury at the London Exhibition. In visiting the stalls of English and French perfumers at the Crystal Palace, we found a great variety of these chemical perfumes, the applications of which were at the same time practically illustrated by confectionery flavored by them. However, as most of the samples of the oils sent to the Exhibition were but small, I was prevented, in many cases, from making an accurate analysis of them. The largest samples were those of a compound labelled "pear-oil," which, by analysis, I discovered to be an alcoholic solution of pure acetate of amyloxide. Not having sufficient quantity to purify it for combustion, I dissolved it with potash, by which free fusel-oil was separated, and determined the acetic acid in the form of a silver salt. 0.3080 gram. of silver salt = 0.1997 gram. of silver. The per centage of silver in acetate of silver is, according to Theory, 64.68 Experiment, 64.55 The acetate of amyloxide, which, according to the usual way of preparing it, represents one part sulphuric acid, one part fusel-oil, and two parts of acetate of potash, had a striking smell of fruit, but it acquired the pleasant flavor of the jargonelle pear only after having been diluted with six times its volume of spirit of wine. Upon further inquiry I learned that considerable quantities of this oil are manufactured by some distillers,--from fifteen to twenty pounds weekly,--and sold to confectioners, who employ it chiefly in flavoring pear-drops, which are nothing else but barley-sugar, flavored with this oil. I found, besides the pear-oil, also an _apple-oil_, which, according to my analysis, is nothing but valerianate of amyloxide. Every one must recollect the insupportable smell of rotten apples which fills the laboratory whilst making valerianic acid. By operating upon this raw distillate produced with diluted potash, valerianic acid is removed, and an ether remains behind, which, diluted in five or six times its volume of spirits of wine, is possessed of the most pleasant flavor of apples. The essential oil[L] most abundant in the Exhibition was the pine-apple oil, which, as you well know, is nothing else but the butyrate of ethyloxide. Even in this combination, like in the former, the pleasant flavor or scent is only attained by diluting the ether with alcohol. The butyric ether which is employed in Germany to flavor bad rum, is employed in England to flavor an acidulated drink called pine-apple ale. For this purpose they generally do not employ pure butyric acid, but a product obtained by saponification of butter, and subsequent distillation of the soap with concentrated sulphuric acid and alcohol; which product contains, besides the butyric ether, other ethers, but nevertheless can be used for flavoring spirits. The sample I analyzed was purer, and appeared to have been made with pure butyric ether. Decomposed with potash and changed into silver salt, it gave 0.4404 gram. of silver salt = 0.2437 gram. of silver. The per centage of silver in the butyrate of silver is according to Theory, 55.38 Experiment, 55.33 Both English and French exhibitors have also sent samples of cognac-oil and grape-oil, which are employed to flavor the common sorts of brandy. As these samples were very small, I was prevented from making an accurate analysis. However, I am certain that the grape-oil is a combination of amyl, diluted with much alcohol; since, when acted upon with concentrated sulphuric acid, and the oil freed from alcohol by washing it with water, it gave amylsulphuric acid, which was identified by the analysis of the salt of barytes. 1.2690 gram. of amylsulphate of barytes gave 0.5825 gram. of sulphate of barytes. This corresponds to 45.82 per cent. of sulphate of barytes. Amylsulphate of barytes, crystallized with two equivalents of water, contains, according to the analysis of Cahours and Kekule, 45.95 per cent. of sulphate of barytes. It is curious to find here a body, which, on account of its noxious smell, is removed with great care from spirituous liquors, to be applied under a different form for the purpose of imparting to them a pleasant flavor. I must needs here also mention the artificial oil of bitter almonds. When Mitscherlich, in the year 1834, discovered the nitrobenzol, he would not have dreamed that this product would be manufactured for the purpose of perfumery, and, after twenty years, appear in fine labelled samples at the London Exhibition. It is true that, even at the time of the discovery of nitrobenzol, he pointed out the striking similarity of its smell to that of the oil of bitter almonds. However, at that time, the only known sources for obtaining this body were the compressed gases and the distillation of benzoic acid, consequently the enormity of its price banished any idea of employing benzol as a substitute for oil of bitter almonds. However, in the year 1845, I succeeded by means of the anilin-reaction in ascertaining the existence of benzol in common coal-tar oil; and, in the year 1849, C.B. Mansfield proved, by careful experiments, that benzol can be won without difficulty in great quantity from coal-tar oil. In his essay, which contains many interesting details about the practical use of benzol, he speaks likewise of the possibility of soon obtaining the sweet-scented nitrobenzol in great quantity. The Exhibition has proved that his observation has not been left unnoticed by the perfumers. Among French perfumeries we have found, under the name of artificial oil of bitter almonds, and under the still more poetical name of "essence de mirbane," several samples of essential oils, which are no more nor less than nitrobenzol. I was not able to obtain accurate details about the extent of this branch of manufacture, which seems to be of some importance. In London, this article is manufactured with success. The apparatus employed is that of Mansfield, which is very simple. It consists of a large glass worm, the upper extremity of which divides in two branches or tubes, which are provided with funnels. Through one of these funnels passes a stream of concentrated nitric acid; the other is destined as a receiver of benzol, which, for this purpose, requires not to be quite pure; at the angle from where the two tubes branch out, the two bodies meet together, and instantly the chemical combination takes place, which cools sufficiently by passing through the glass worm. The product is afterwards washed with water, and some diluted solution of carbonate of soda; it is then ready for use. Notwithstanding the great physical similarity between nitrobenzol and oil of bitter almonds, there is yet a slight _difference in smell which can be detected by an experienced nose_.[M] However, nitrobenzol is very useful in scenting soap, and might be employed with great advantage by confectioners and cooks, particularly on account of its safety, being entirely free from prussic acid. There were, besides the above, several other artificial oils; they all, however, were more or less complicated, and in so small quantities, that it was impossible to ascertain their exact nature, and it was doubtful whether they had the same origin as the former. The application of organic chemistry to perfumery is quite new; it is probable that the study of all the ethers or ethereal combinations already known, and of those which the ingenuity of the chemist is daily discovering, will enlarge the sphere of their practical applications. The capryl-ethers lately discovered by Bouis are remarkable for their aromatic smells (the acetate of capryloxide is possessed of the most intense and pleasant smell), and they promise a large harvest to the manufacturers of perfumes.--_Annalen der Chemie._ * * * * * CORRESPONDENCE FROM THE "JOURNAL OF THE SOCIETY OF ARTS."[N] CHEMISTRY AND PERFUMERY. SIR, When such periodicals as "Household Words" and the "Family Herald" contain scientific matters, treated in a manner to popularize science, all real lovers of philosophy must feel gratified; a little fiction, a little metaphor, is expected, and is accepted with the good intention with which it is given, in such popular prints; but when the "Journal of the Society of Arts" reprints quotations from such sources, without modifying or correcting their expressions, it conveys to its readers a tissue of fiction rather too flimsy to bear a truthful analysis.[O] In the article on Chemistry and Perfumery, in No. 47, you quote that "some of the most delicate perfumes are now made by chemical artifice, and not, as of old, by distilling them from flowers." Now, sir, this statement conveys to the public a very erroneous idea; because the substances afterwards spoken of are named essences of fruit, and not essences of flowers, and the essences of fruits named in your article never are, and never can be, used in perfumery. This assertion is based on practical experience. The artificial essences of fruits are ethers: when poured upon a handkerchief, and held up to the nose, they act, as is well known, like chloroform. Dare a perfumer sell a bottle of such a preparation to an "unprotected female?" Again, you quote that "the drainings of cow-houses are the main source to which the manufacturer applies for the production of his most delicate and admired perfumes." Shade of Munchausen! must I refute this by calling your attention to the fact that in the south of France more than 80,000 persons are employed, directly and indirectly, in the cultivation of flowers, and in the extraction of their odors for the use of perfumers? that Italy cultivates flowers for the same purpose to an extent employing land as extensive as the whole of some English counties? that tracts of flower-farms exist in the Balkan, in Turkey, more extensive than the whole of Yorkshire? Our own flower-farms at Mitcham, in Surrey, need not be mentioned in comparison, although important. These, sir, are the main sources of perfumes. There are other sources at Thibet, Tonquin, and in the West Indies; but enough has been said, I hope, to refute the cow-house story. This story is founded on the fact that Benzoic acid _can be_ obtained from the draining of stables, and that Benzoic acid has rather a pleasant odor. Some of the largest wholesale perfumers use five or six pounds of gum benzoin per annum, but none use the benzoic acid. The lozenge-makers consume the most of this article when prepared for commercial purposes; as also the fruit essences. Those of your readers interested in what _really is used_ in perfumery, are referred to the last six numbers of the "Annals of Pharmacy and Practical Chemistry," article "Perfumery." Your obedient servant, SEPTIMUS PIESSE. CHEMISTRY AND PERFUMERY.[P] SIR, The discussion about chemistry and perfumery, in reality amounts to this: Mr. Septimus Piesse confines the term "perfumery" to such things as Eau de Cologne, &c.; perfumed soaps, groceries, &c., he does not appear to class as "perfumery." Now the artificial scents are as yet chiefly used for the latter substances, which in common language, and, I should say, in a perfumer's nomenclature also, would be included in perfumery. The authority for cows' urine being used for perfumery is to be found in a little French work called, I believe, "La Chimie de l'Odorat" in which a full description is given of the collection of fresh urine and its application to this purpose. I need scarcely say, that it is the benzoic acid of the urine which is the odoriferous principle. Your obedient servant, A PERFUMER. [When benzoic acid is prepared by any of the wet processes, it is _free from the fragrant volatile oil_ which accompanies it when prepared by sublimation from the resin, and to which oil the acid of commerce owes its peculiar odor. This fact completely nullifies the above assertion.--SEPTIMUS PIESSE.] CHEMISTRY AND PERFUMERY.[Q] Sir, If the author of the Letter on Chemistry and Perfumery, published in No. 50 of your Journal, and intended as a reply to mine--though none was needed--which appeared in No. 49, really be a perfumer, as his signature implies, he would know that I could not, though ever so inclined, "confine the term perfumery" to various odoriferous substances, and exclude scented soaps; because he would be aware that one-third of the returns of every manufacturing perfumer is derived from perfumed soap. I do however emphatically exclude from the term perfumery, "groceries, &c.," the _et cætera_ meaning, I presume, "confectionery," because perfumery has to do with one of the senses, SMELLING, while groceries, &c., are distinguishable by another, TASTE; and had not our physical faculties clearly made the distinction, commerce and manufactures would have defined them: I therefore repeat, that the artificial essences of fruits are not used in perfumery, as stated in No. 47, from the quoted authorities. If any man can deny this assertion, let him now do so, "or forever after hold his peace," at least upon this subject. The "Journal of the Society of Arts" is not a medium of mere controversy. If a statement be made in error, let truth correct it, which, if gain-sayed, it should be done, not under the veil of an anonymous correspondent, but with a name to support the assertion. Science has to deal with tangible facts and figures, to the political alone belongs the anonymous ink-spiller. I am, sir, yours faithfully, SEPTIMUS PIESSE. 42 Chapel Street, Edgware Road. [If the word _flavor_ had been used by the various authors who have written upon this subject, in place of the word _perfume_, the dissemination of an erroneous idea would have been prevented: the word perfume, applied to pear-oil, pine-apple oil, &c., implies, and the general tenor of the remarks of the writers leads the reader to infer, that these substances are used by perfumers, who not only do not, but cannot use them in their trade. But for _flavoring_ nectar, lozenges, sweetmeats, &c., these ethers, or oils as the writers term them, are extensively used, and quite in accordance with assertions of Hoffman, Playfair, Fehling, and Bastick. However, the glorious achievements of modern chemistry have not lost anything by this misapplication of a trade term.--SEPTIMUS PIESSE.] * * * * * OTTOS FROM PLANTS. QUANTITIES OF OTTOS, OTHERWISE ESSENTIAL OILS, YIELDED BY VARIOUS PLANTS. Pounds Of otto. Orange-peel, 10 yield about 1 oz. Dry marjoram herb, 20 " 3 oz. Fresh " " 100 " 3 oz. " Peppermint, 100 " 3 to 4 oz. Dry " 25 " 3 to 4 oz. " Origanum, 25 " 2 to 3 oz. " Thyme, 20 " 1 to 1-1/2 oz. " Calamus, 25 " 3 to 4 oz. Anise-seed, 25 " 9 to 12 oz. Caraway, 25 " 16 oz. Cloves, 1 " 2-1/2 oz. Cinnamon, 25 " 3 oz. Cassia, 25 " 3 oz. Cedar-wood, 28 " 4 oz. Mace, 2 " 3 oz. Nutmegs, 2 " 3 to 4 oz. Fresh balm herb, 60 " 1 to 1-1/2 oz. Cake of bitter almond, 14 " 1 oz. Sweet flag root, 112 " 16 oz. Geranium leaves, 112 " 2 oz. Lavender flowers, 112 " 30 to 32 oz. Myrtle leaves, 112 " 5 oz. Patchouly herb, 112 " 28 oz. Province rose blossom, 112 " 1-1/2 to 2 drachms. Rhodium-wood, 112 " 3 to 4 oz. Santal-wood, 112 " 30 oz. Vitivert or kus-kus-root, 112 " 15 oz. * * * * * WEIGHTS AND MEASURES. FRENCH WEIGHTS AND MEASURES COMPARED WITH ENGLISH. _____________________________________________________________ | |Imperial | |Troy |Kilo- |Lbs. | |Litres. |Gallons. |Grammes. |Grains. |grammes. |Avoird. | | 1, | 0.22010 | 1, | 15.434 | 1, | 2.20486 | | 2, | 0.44019 | 2, | 30.868 | 2, | 4.40971 | | 3, | 0.66029 | 3, | 46.302 | 3, | 6.61457 | | 4, | 0.88039 | 4, | 61.736 | 4, | 8.81943 | | 5, | 1.10048 | 5, | 77.170 | 5, | 11.02429 | | 6, | 1.32058 | 6, | 92.604 | 6, | 13.22914 | | 7, | 1.54068 | 7, | 108.038 | 7, | 15.43400 | | 8, | 1.76077 | 8, | 123.472 | 8, | 17.63886 | | 9, | 1.98087 | 9, | 138.906 | 9, | 19.84371 | ------------------------------------------------------------- ENGLISH WEIGHTS AND MEASURES COMPARED WITH FRENCH. _____________________________________________________________ |Imp. | |Troy | |Lbs. |Kilo- | |Gallons. |Litres. |Grains. |Grammes. |Avoird. |grammes. | | 1, | 4.54346 | 1, | 0.06479 | 1, | 0.45354 | | 2, | 9.08692 | 2, | 0.12958 | 2, | 0.90709 | | 3, | 13.63038 | 3, | 0.19438 | 3, | 1.36063 | | 4, | 18.17384 | 4, | 0.25917 | 4, | 1.81418 | | 5, | 22.71730 | 5, | 0.32396 | 5, | 2.26772 | | 6, | 27.26076 | 6, | 0.38875 | 6, | 2.72126 | | 7, | 31.80422 | 7, | 0.45354 | 7, | 3.17481 | | 8, | 36.34768 | 8, | 0.51834 | 8, | 3.62835 | | 9, | 40.89114 | 9, | 0.58313 | 9, | 4.08190 | ------------------------------------------------------------- FOOTNOTES: [A] Brother of the Author. [B] See Appendix, "Benzoic Acid." [C] See "Incense." [D] The duty on eau de Cologne is now, according to the last tariff, 8_d._ per flacon of 4 oz., or 20_s._ per gallon. [E] Simple syrup consists of 3 lbs. of loaf sugar, boiled for a minute in one pint, imperial, of distilled water. [F] The imperial measure only is recognized among perfumers. [G] Annals of Pharmacy, vol. ii, pp. 168, 169. [H] The deposit is nearly insoluble in water, is acid and astringent to the taste, gives an acid reaction with litmus. Spirit of wine dissolves out a small portion, which, on evaporation, leaves a thick oleo-resinous substance, having a rancid smell. Ether leaves a pleasant-smelling resin, somewhat resembling camphor. The remainder is nearly insoluble in liq. ammoniæ, liq. potassæ, more soluble in nitric acid, and well deserves to be further examined. [I] Qy. Confectionery? [J] Qy. Confectioners? [K] Confectionery. [L] The writer means ether! [M] See "Almond." [N] No. 49. [O] If our Correspondent had carefully read the article he so fiercely attacks, he would have seen that the authorities were Dr. Lyon Playfair's Lecture, and Professsor Fehling, in the "Wurtemberg Journal of Industry."--ED. [P] No. 50. [Q] No. 52. 
46953	----	Transcriber's Note: #################### This e-text is based on the 1882 edition. The original spelling, as well as the use of punctuation and quotation marks, have been retained. The following errors have been corrected: # p. xi: 'Sauturnes' --> 'Sauternes' # p. 52: 'which ne declares' --> 'which he declares' # p. 154: 'its owes' --> 'it owes' # p. 204: 'Bonaporte' --> 'Bonaparte' # p. 220: 'histriographer' --> 'historiographer' # p. 229: 'Reputatiou' --> 'Reputation' # p. 256: 'Saint-Poray' --> 'Saint-Péray' # Footnote 412: 'tho gas' --> 'the gas' The caret symbol (^) characterises subsequent superscript text; [oe] is the symbol for the oe-ligature. [asterism] depicts a corresponding typographical symbol. The following text variations have been marked by special characters: Italic: underscores (_italic_) Bold: equals signs (=bold=) Small caps: forward slashes (/small caps/) Underlined: tildes (~underlined~) [Illustration: A SUPPER UNDER THE REGENCY.] A HISTORY OF CHAMPAGNE WITH NOTES ON THE OTHER SPARKLING WINES OF FRANCE. BY HENRY VIZETELLY, CHEVALIER OF THE ORDER OF FRANZ-JOSEF, AUTHOR OF 'THE WINES OF THE WORLD CHARACTERISED AND CLASSED,' 'FACTS ABOUT PORT AND MADEIRA,' 'FACTS ABOUT CHAMPAGNE AND OTHER SPARKLING WINES,' 'FACTS ABOUT SHERRY,' ETC. [Illustration] ILLUSTRATED WITH 350 ENGRAVINGS. LONDON: _VIZETELLY & CO., 42 CATHERINE STREET, STRAND. SCRIBNER & WELFORD, NEW YORK._ 1882. LONDON: ROBSON AND SONS, PRINTERS, PANCRAS ROAD, N.W. PREFACE. The present is the first instance in which the history of any wine has been traced with the same degree of minuteness as the history of the still and sparkling wines of the Champagne has been traced in the following pages. And not only have the author's investigations extended over a very wide range, as will be seen by the references contained in the footnotes to this volume, but during the past ten years he has paid frequent visits to the Champagne--to its vineyards and vendangeoirs, and to the establishments of the chief manufacturers of sparkling wine, the preparation of which he has witnessed in all its phases. Visits have, moreover, been made to various other localities where sparkling wines are produced, and more or less interesting information gathered regarding the latter. In the pursuit of his researches, the author's position as wine juror at the Vienna and Paris Exhibitions opened up to him many sources of information inaccessible to others less favourably circumstanced, and these his general knowledge of wine, acquired during many years' careful study, enabled him to turn to advantageous account. The numerous illustrations scattered throughout the present volume have been derived from every available source that suggested itself. Ancient /MSS./, early-printed books, pictures and pieces of sculpture, engravings and caricatures, all of greater or less rarity, have been laid under contribution; and in addition, nearly two hundred original sketches have been made under the author's immediate superintendence, with the object of illustrating the principal localities and their more picturesque features, and depicting all matters of interest connected with the growth and manipulation of the various sparkling wines which are here described. In the preparation of this work, and more particularly the historical portions of it, the author has been largely assisted by his nephew, Mr. Montague Vizetelly, to whom he tenders his warmest acknowledgments for the valuable services rendered by him. It should be stated that portions of the volume, relating to the vintaging and manufacture of sparkling wines generally, have been previously published under the title of _Facts about Champagne and other Sparkling Wines_, but they have been subjected to considerable extension and revision before being permitted to reappear in their present form. St. Leonards-on-Sea, February 1882. CONTENTS. /Part I./ I. /Early Renown of the Champagne Wines./ PAGE The vine in Gaul--Domitian's edict to uproot it--Plantation of vineyards under Probus--Early vineyards of the Champagne--Ravages by the Northern tribes repulsed for a time by the Consul Jovinus--St. Remi and the baptism of Clovis--St. Remi's vineyards--Simultaneous progress of Christianity and the cultivation of the vine--The vine a favourite subject of ornament in the churches of the Champagne--The culture of the vine interrupted, only to be renewed with increased ardour--Early distinction between 'Vins de la Rivière' and 'Vins de la Montagne'--A prelate's counsel respecting the proper wine to drink--The Champagne desolated by war--Pope Urban II., a former Canon of Reims Cathedral--His partiality for the wine of Ay--Bequests of vineyards to religious establishments--Critical ecclesiastical topers--The wine of the Champagne causes poets to sing and rejoice--'La Bataille des Vins'--Wines of Auviller and Espernai le Bacheler 1 II. /The Wines of the Champagne from the Fourteenth to the Seventeenth Century./ Coronations at Reims and their attendant banquets--Wine flows profusely at these entertainments--The wine-trade of Reims--Presents of wine from the Reims municipality--Cultivation of the vineyards abandoned after the battle of Poitiers--Octroi levied on wine at Reims--Coronation of Charles V.--Extension of the Champagne vineyards--Abundance of wine--Visit to Reims of the royal sot Wenceslaus of Bohemia--The Etape aux Vins at Reims--Increased consumption of beer during the English occupation of the city--The Maid of Orleans at Reims--The vineyards and wine-trade alike suffer--Louis XI. is crowned at Reims--Fresh taxes upon wine followed by the Mique-Maque revolt--The Rémois the victims of pillaging foes and extortionate defenders--The Champagne vineyards attacked by noxious insects--Coronation of Louis XII.--François Premier, the Emperor Charles V., Bluff King Hal, and Leo the Magnificent all partial to the wine of Ay--Mary Queen of Scots at Reims--State kept by the opulent and libertine Cardinal of Lorraine--Brusquet, the Court Fool--Decrease in the production of wine around Reims--Gifts of wine to newly-crowned monarchs--New restrictions on vine cultivation--The wine of the Champagne crowned at the same time as Louis XIII.--Regulation price for wine established at Reims--Imposts levied on the vineyards by the Frondeurs--The country ravaged around Reims--Sufferings of the peasantry--Presents of wine to Marshal Turenne and Charles II. of England--Perfection of the Champagne wines during the reign of Louis XIV.--St. Evremond's high opinion of them--Other contemporary testimony in their favour--The Archbishop of Reims's niggardly gift to James II. of England--A poet killed by Champagne--Offerings by the Rémois to Louis XIV. on his visit to their city 12 III. /Invention and Development of Sparkling Champagne./ The ancients acquainted with sparkling wines--Tendency of Champagne wines to effervesce noted at an early period--Obscurity enveloping the discovery of what we now know as sparkling Champagne--The Royal Abbey of Hautvillers--Legend of its foundation by St. Nivard and St. Berchier--Its territorial possessions and vineyards--The monks the great viticulturists of the Middle Ages--Dom Perignon--He marries wines differing in character--His discovery of sparkling white wine--He is the first to use corks to bottles--His secret for clearing the wine revealed only to his successors Frère Philippe and Dom Grossart--Result of Dom Perignon's discoveries--The wine of Hautvillers sold at 1000 livres the queue--Dom Perignon's memorial in the Abbey-Church--Wine flavoured with peaches--The effervescence ascribed to drugs, to the period of the moon, and to the action of the sap in the vine--The fame of sparkling wine rapidly spreads--The Vin de Perignon makes its appearance at the Court of the Grand Monarque--Is welcomed by the young courtiers--It figures at the suppers of Anet and Chantilly, and at the orgies of the Temple and the Palais Royal--The rapturous strophes of Chaulieu and Rousseau--Frederick William I. and the Berlin Academicians--Augustus the Strong and the page who pilfered his Champagne--Horror of the old-fashioned _gourmets_ at the innovation--Bertin du Rocheret and the Marshal d'Artagnan--System of wine-making in the Champagne early in the eighteenth century--Bottling of the wine in flasks--Icing Champagne with the corks loosened 34 IV. /The Battle of the Wines./ Temporary check to the popularity of sparkling Champagne--Doctors disagree--The champions of Champagne and Burgundy--Péna and his patient--A young Burgundian student attacks the wine of Reims--The Faculty of Reims in arms--A local Old Parr cited as an example in favour of the wines of the Champagne--Salins of Beaune and Le Pescheur of Reims engage warmly in the dispute--A pelting with pamphlets--Burgundy sounds a war-note--The Sapphics of Benigné Grenan--An asp beneath the flowers--The gauntlet picked up--Carols from a coffin--Champagne extolled as superior to all other wines--It inspires the heart and stirs the brain--The apotheosis of Champagne foam--Burgundy, an invalid, seeks a prescription--Impartially appreciative drinkers of both wines--Bold Burgundian and stout Rémois, each a jolly tippling fellow--Canon Maucroix's parallel between Burgundy and Demosthenes and Champagne and Cicero--Champagne a panacea for gout and stone--Final decision in favour of Champagne by the medical faculty of Paris--Pluche's opinion on the controversy--Champagne a lively wit and Burgundy a solid understanding--Champagne commands double the price of the best Burgundy--Zealots reconciled at table 47 V. /Progress and Popularity of Sparkling Champagne./ Sparkling Champagne intoxicates the Regent d'Orléans and the _roués_ of the Palais Royal--It is drunk by Peter the Great at Reims--A horse trained on Champagne and biscuits--Decree of Louis XV. regarding the transport of Champagne--Wine for the _petits cabinets du Roi_--The _petits soupers_ and Champagne orgies of the royal household--A bibulous royal mistress--The Well-Beloved at Reims--Frederick the Great, George II., Stanislas Leczinski, and Marshal Saxe all drink Champagne--Voltaire sings the praises of the effervescing wine of Ay--The Commander Descartes and Lebatteux extol the charms of sparkling Champagne--Bertin du Rocheret and his balsamic molecules--The Bacchanalian poet Panard chants the inspiring effects of the vintages of the Marne--Marmontel is jointly inspired by Mademoiselle de Navarre and the wine of Avenay--The Abbé de l'Attaignant and his fair hostesses--Breakages of bottles in the manufacturers' cellars--Attempts to obviate them--The early sparkling wines merely _crémant_--_Saute bouchon_ and _demi-mousseux_--Prices of Champagne in the eighteenth century--Preference given to light acid wines for sparkling Champagne--Lingering relics of prejudice against _vin mousseux_--The secret addition of sugar--Originally the wine not cleared in bottle--Its transfer to other bottles necessary--Adoption of the present method of ridding the wine of its deposit--The vine-cultivators the last to profit by the popularity of sparkling Champagne--Marie Antoinette welcomed to Reims--Reception and coronation of Louis XVI. at Reims--'The crown, it hurts me!'--Oppressive dues and tithes of the _ancien régime_--The Fermiers Généraux and their hôtel at Reims--Champagne under the Revolution--Napoleon at Epernay--Champagne included in the equipment of his satraps--The Allies in the Champagne--Drunkenness and pillaging--Appreciation of Champagne by the invading troops--The beneficial results which followed--Universal popularity of Champagne--The wine a favourite with kings and potentates--Its traces to be met with everywhere 57 VI. /Champagne in England./ The strong and foaming wine of the Champagne forbidden his troops by Henry V.--The English carrying off wine when evacuating Reims on the approach of Jeanne Darc--A legend of the siege of Epernay--Henry VIII. and his vineyard at Ay--Louis XIV.'s present of Champagne to Charles II.--The courtiers of the Merry Monarch retain the taste for French wine acquired in exile--St. Evremond makes the Champagne flute the glass of fashion--Still Champagne quaffed by the beaux of the Mall and the rakes of the Mulberry Gardens--It inspires the poets and dramatists of the Restoration--Is drank by James II. and William III.--The advent of sparkling Champagne in England--Farquhar's _Love and a Bottle_--Mockmode the Country Squire and the witty liquor--Champagne the source of wit--Port-wine and war combine against it, but it helps Marlborough's downfall--Coffin's poetical invitation to the English on the return of peace--A fraternity of chemical operators who draw Champagne from an apple--The influence of Champagne in the Augustan age of English literature--Extolled by Gay and Prior--Shenstone's verses at an inn--Renders Vanbrugh's comedies lighter than his edifices--Swift preaches temperance in Champagne to Bolingbroke--Champagne the most fashionable wine of the eighteenth century--Bertin du Rocheret sends it in cask and bottle to the King's wine-merchant--Champagne at Vauxhall in Horace Walpole's day--Old Q. gets Champagne from M. de Puissieux--Lady Mary's Champagne and chicken--Champagne plays its part at masquerades and bacchanalian suppers--Becomes the beverage of the ultra-fashionables above and below stairs--Figures in the comedies of Foote, Garrick, Coleman, and Holcroft--Champagne and real pain--Sir Edward Barry's learned remarks on Champagne--Pitt and Dundas drunk on Jenkinson's Champagne--Fox and the Champagne from Brooks's--Champagne smuggled from Jersey--Grown in England--Experiences of a traveller in the Champagne trade in England at the close of the century--Sillery the favourite wine--Nelson and the 'fair Emma' under the influence of Champagne--The Prince Regent's partiality for Champagne punch--Brummell's Champagne blacking--The Duke of Clarence overcome by Champagne--Curran and Canning on the wine--Henderson's praise of Sillery--Tom Moore's summer fête inspired by Pink Champagne--Scott's Muse dips her wing in Champagne--Byron's sparkling metaphors--A joint-stock poem in praise of Pink Champagne--The wheels of social life in England oiled by Champagne--It flows at public banquets and inaugurations--Plays its part in the City, on the Turf, and in the theatrical world--Imparts a charm to the dinners of Belgravia and the suppers of Bohemia--Champagne the ladies' wine _par excellence_--Its influence as a matrimonial agent--'O the wildfire wine of France!' 83 /Part II./ I. /The Champagne Vinelands--The Vineyards of the River./ The vinelands in the neighbourhood of Epernay--Viticultural area of the Champagne--A visit to the vineyards of 'golden plants'--The Dizy vineyards--Antiquity of the Ay vineyards--St. Tresain and the wine-growers of Ay--The Ay vintage of 1871--The Mareuil vineyards and their produce--Avernay; its vineyards, wines, and ancient abbey--The vineyards of Mutigny and Cumières--Damery and 'la belle hôtesse' of Henri Quatre--Adrienne Lecouvreur and the Maréchal de Saxe's matrimonial schemes--Pilgrimage to Hautvillers--Remains of the Royal Abbey of St. Peter--The ancient church--Its quaint decorations and monuments--The view from the heights of Hautvillers--The abbey vineyards and wine-cellars in the days of Dom Perignon--The vinelands of the Côte d'Epernay--Pierry and its vineyard cellars--The Moussy, Vinay, and Ablois St. Martin vineyards--The Côte d'Avize--Chavot, Monthelon, Grauves, and Cuis--The vineyards of Cramant and Avize, and their light delicate white wines--The Oger and Le Mesnil vineyards--Vertus and its picturesque ancient remains--Its vineyards planted with Burgundy grapes from Beaune--The red wine of Vertus a favourite beverage of William III. of England 117 II. /The Champagne Vinelands--The Vineyards of the Mountain./ The wine of Sillery--Origin of its renown--The Maréchale d'Estrées a successful Marchande de Vin--The Marquis de Sillery the greatest wine-farmer in the Champagne--Cossack appreciation of the Sillery produce--The route from Reims to Sillery--Henri Quatre and the Taissy wines--Failure of the Jacquesson system of vine cultivation--Château of Sillery--Wine-making at M. Fortel's--Sillery sec--The vintage at Verzenay and the vendangeoirs--Renown of the Verzenay wine--The Verzy vineyards--Edward III. at the Abbey of St. Basle--Excursion from Reims to Bouzy--The herring procession at St. Remi--Rilly, Chigny, and Ludes--The Knights Templars' 'pot' of wine--Mailly and the view over the Champagne plains--Wine-making at Mailly--The village in the wood--Château and park of Louvois, Louis le Grand's War Minister--The vineyards of Bouzy--Its church-steeple, and the lottery of the great gold ingot--Pressing grapes at the Werlé vendangeoir--Still red Bouzy--Ambonnay--A pattern peasant vine-proprietor--The Ambonnay vintage--The vineyards of Ville-Dommange and Sacy, Hermonville and St. Thierry--The still red wine of the latter 130 III. /The Vines of the Champagne and the System of Cultivation./ A combination of circumstances essential to the production of good Champagne--Varieties of vines cultivated in the Champagne vineyards--Different classes of vine-proprietors--Cost of cultivation--The soil of the vineyards--Period and system of planting the vines--The operation of 'provenage'--The 'taille' or pruning, the 'bêchage' or digging--Fixing the vine-stakes--Great cost of the latter--Manuring and shortening back the vines--The summer hoeing around the plants--Removal of the stakes after the vintage--Precautions adopted against spring frosts--The Guyot system of roofing the vines with matting--Forms a shelter from rain, hail, and frost, and aids the ripening of the grapes--Various pests that prey upon the Champagne vines--Destruction caused by the Eumolpe, the Chabot, the Bêche, the Cochylus, and the Pyrale--Attempts made to check the ravages of the latter with the electric light 140 IV. /The Vintage in the Champagne./ Period of the Champagne vintage--Vintagers summoned by beat of drum--Early morning the best time for plucking the grapes--Excitement in the neighbouring villages at vintage-time--Vintagers at work--Mules employed to convey the gathered grapes down the steeper slopes--The fruit carefully examined before being taken to the wine-press--Arrival of the grapes at the vendangeoir--They are subjected to three squeezes, and then to the 'rébêche'--The must is pumped into casks and left to ferment--Only a few of the vine-proprietors in the Champagne press their own grapes--The prices the grapes command--Air of jollity throughout the district during the vintage--Every one is interested in it, and profits by it--Vintagers' fête on St. Vincent's-day--Endless philandering between the sturdy sons of toil and the sunburnt daughters of labour 148 V. /The Preparation of Champagne./ The treatment of Champagne after it comes from the wine-press--The racking and blending of the wine--The proportions of red and white vintages composing the 'cuvée'--Deficiency and excess of effervescence--Strength and form of Champagne bottles--The 'tirage' or bottling of the wine--The process of gas-making commences--Details of the origin and development of the effervescent properties of Champagne--The inevitable breakage of bottles which ensues--This remedied by transferring the wine to a lower temperature--The wine stacked in piles--Formation of sediment--Bottles placed 'sur pointe' and daily shaken to detach the deposit--Effect of this occupation on those incessantly engaged in it--The present system originated by a workman of Madame Clicquot's--'Claws' and 'masks'--Champagne cellars--Their construction and aspect--Raw recruits for the 'Regiment de Champagne'--Transforming the 'vin brut' into Champagne--Disgorging and liqueuring the wine--The composition of the liqueur--Variation in the quantity added to suit diverse national tastes--The corking, stringing, wiring, and amalgamating--The wine's agitated existence comes to an end--The bottles have their toilettes made--Champagne sets out on its beneficial pilgrimage round the world 154 VI. /Reims and its Champagne Establishments./ The city of Reims--Its historical associations--The Cathedral--Its western front one of the most splendid conceptions of the thirteenth century--The sovereigns crowned within its walls--Present aspect of the ancient archiepiscopal city--The woollen manufactures and other industries of Reims--The city undermined with the cellars of the great Champagne firms--Reims hotels--Gothic house in the Rue du Bourg St. Denis--Renaissance house in the Rue de Vesle--Church of St. Jacques: its gateway and quaint weathercock--The Rue des Tapissiers and the Chapter Court--The long tapers used at religious processions--The Place des Marchés and its ancient houses--The Hôtel de Ville--Statue of Louis XIII.--The Rues de la Prison and du Temple--Messrs. Werlé & Co., successors to the Veuve Clicquot-Ponsardin--Their offices and cellars on the site of a former Commanderie of the Templars--Origin of the celebrity of Madame Clicquot's wines--M. Werlé and his son--Remains of the Commanderie--The forty-five cellars of the Clicquot-Werlé establishment--Our tour of inspection through them--Ingenious dosing machine--An explosion and its consequences--M. Werlé's gallery of paintings--Madame Clicquot's Renaissance house and its picturesque bas-reliefs--The Werlé vineyards and vendangeoirs 168 VII. /Reims and its Champagne Establishments/ (_continued_). The house of Louis Roederer founded by a plodding German named Schreider--The central and other establishments of the firm--Ancient house in the Rue des Elus--The gloomy-looking Rue des Deux Anges and prison-like aspect of its houses--Inside their courts the scene changes--Handsome Renaissance house and garden, a former abode of the canons of the Cathedral--The Place Royale--The Hôtel des Fermes and the statue of the 'wise, virtuous, and magnanimous Louis XV.'--Birthplace of Colbert in the Rue de Cérès--Quaint Adam and Eve gateway in the Rue de l'Arbalète--Heidsieck & Co.'s central establishment in the Rue de Sedan--Their famous 'Monopole' brand--The firm founded in the last century--Their extensive cellars inside and outside Reims--The matured wines shipped by them--The Boulevard du Temple--M. Ernest Irroy's cellars, vineyards, and vendangeoirs--Recognition by the Reims Agricultural Association of his plantations of vines--His wines and their popularity at the best London clubs--Various Champagne firms located in this quarter of Reims--The Rue du Tambour and the famous House of the Musicians--The Counts de la Marck assumed former occupants of the latter--The Brotherhood of Minstrels of Reims--Périnet & Fils' establishment in the Rue St. Hilaire--Their cellars of three stories in solid masonry--Their soft, light, and delicate wines--A rare still Verzenay--The firm's high-class Extra Sec 179 VIII. /Reims and its Champagne Establishments/ (_continued_). La Prison de Bonne Semaine--Mary Queen of Scots at Reims--Messrs. Pommery & Greno's offices--A fine collection of faïence--The Rue des Anglais a former refuge of English Catholics--Remains of the old University of Reims--Ancient tower and grotto--The handsome castellated Pommery establishment--The spacious cellier and huge carved cuvée tuns--The descent to the cellars--Their great extent--These lofty subterranean chambers originally quarries, and subsequently places of refuge of the early Christians and the Protestants--Madame Pommery's splendid cuvées of 1868 and 1874--Messrs. de St. Marceaux & Co.'s new establishment in the Avenue de Sillery--Its garden-court and circular shaft--Animated scene in the large packing hall--Lowering bottled wine to the cellars--Great depth and extent of these cellars--Messrs. de St. Marceaux & Co.'s various wines--The establishment of Veuve Morelle & Co., successors to Max Sutaine--The latter's 'Essai sur le Vin de Champagne'--The Sutaine family formerly of some note at Reims--Morelle & Co.'s cellars well adapted to the development of sparkling wines--The various brands of the house--The Porte Dieu-Lumière 188 IX. /Epernay./ The connection of Epernay with the production of wine of remote date--The town repeatedly burnt and plundered--Hugh the Great carries off all the wine of the neighbourhood--Vineyards belonging to the Abbey of St. Martin in the eleventh, twelfth, and thirteenth centuries--Abbot Gilles orders the demolition of a wine-press which infringes the abbey's feudal rights--Bequests of vineyards in the fifteenth century--Francis I. bestows Epernay on Claude Duke of Guise in 1544--The Eschevins send a present of wine to their new seigneur--Wine levied for the king's camp at Rethel and the strongholds of the province by the Duc de Longueville--Epernay sacked and fired on the approach of Charles V.--The Charles-Fontaine vendangeoir at Avenay--Destruction of the immense pressoirs of the Abbey of St. Martin--The handsome Renaissance entrance to the church of Epernay--Plantation of the 'terre de siége' with vines in 1550--Money and wine levied on Epernay by Condé and the Duke of Guise--Henri Quatre lays siege to Epernay--Death of Maréchal Biron--Desperate battle amongst the vineyards--Triple talent of the 'bon Roy Henri' for drinking, fighting, and love-making--Verses addressed by him to his 'belle hôtesse' Anne du Puy--The Epernay Town Council make gifts of wine to various functionaries to secure their good-will--Presents of wine to Turenne at the coronation of Louis XIV.--Petition to Louvois to withdraw the Epernay garrison that the vintage may be gathered in--The Duke and Duchess of Orleans at Epernay--Louis XIV. partakes of the local vintage at the maison abbatiale on his way to the army of the Rhine--Increased reputation of the wine of Epernay at the end of the seventeenth century--Numerous offerings of it to the Marquis de Puisieux, Governor of the town--The Old Pretender presented at Epernay with twenty-four bottles of the best--Sparkling wine sent to the Marquis de Puisieux at Sillery, and also to his nephew--Further gifts to the Prince de Turenne--The vintage destroyed by frost in 1740--The Epernay slopes at this epoch said to produce the most delicious wine in Europe--Vines planted where houses had formerly stood--The development of the trade in sparkling wine--A 'tirage' of fifty thousand bottles in 1787--Arthur Young drinks Champagne at Epernay at forty sous the bottle--It is surmised that Louis XVI., on his return from Varennes, is inspired by Champagne at Epernay--Napoleon and his family enjoy the hospitality of Jean Remi Moët--King Jerome of Westphalia's true prophecy with regard to the Russians and Champagne--Disgraceful conduct of the Prussians and Russians at Epernay in 1814--The Mayor offers them the free run of his cellars--Charles X., Louis Philippe, and Napoleon III. accept the 'vin d'honneur' at Epernay--The town occupied by German troops during the war of 1870-1 195 X. /The Champagne Establishments of Epernay and Pierry./ Early records of the Moët family at Reims and Epernay--Jean Remi Moët, the founder of the commerce in Champagne wines--Extracts from old account-books of the Moëts--Jean Remi Moët receives the Emperor Napoleon, the Empress Josephine, and the King of Westphalia--The firm of Moët & Chandon constituted--Their establishment in the Rue du Commerce--The delivery and washing of new bottles--The numerous vineyards and vendangeoirs of the firm--Their cuvée made in vats of 12,000 gallons--The bottling of the wine--A subterranean city, with miles of streets, cross-roads, open spaces, tramways, and stations--The ancient entrance to these vaults--Tablet commemorative of the visit of Napoleon I.--The original vaults known as Siberia--Scene in the packing-hall--Messrs. Moët & Chandon's large and complete staff--The famous 'Star' brand of the firm--Perrier-Jouët's château, offices, and cellars--Classification of the wine of the house--The establishment of Messrs. Pol Roger & Co.--Their large stock of the fine 1874 vintage--The preparations for the tirage--Their vast fireproof cellier and its temperature--Their lofty and capacious cellars--Pierry becomes a wine-growing district consequent upon Dom Perignon's discovery--Esteem in which the growths of the Clos St. Pierre were held--Cazotte, author of _Le Diable Amoureux_, and guillotined for planning the escape of Louis XVI. from France, a resident at Pierry--His contest with the Abbot of Hautvillers with reference to the abbey tithes of wine--The Château of Pierry--Its owner demands to have it searched to prove that he is not a forestaller of corn--The vineyards and Champagne establishment of Gé-Dufaut & Co.--The reserves of old wines in the cellars of this firm--Honours secured by them at Vienna and Paris 205 XI. /Some Champagne Establishments at Ay and Mareuil./ The _bourgade_ of Ay and its eighteenth-century château--Gambling propensities of a former owner, Balthazar Constance Dangé-Dorçay-- Appreciation of the Ay vintage by Sigismund of Bohemia, Leo X., Charles V., Francis I., and Henry VIII.--Bertin du Rocheret celebrates this partiality in triolets--Estimation of the Ay wine in the reigns of Charles IX. and Henri III.--Is a favoured drink with the leaders of the League, and with Henri IV., Catherine de Medicis, and the courtiers of that epoch--The 'Vendangeoir d'Henri Quatre' at Ay--The King's pride in his title of Seigneur d'Ay and Gonesse--Dominicus Baudius punningly suggests that the 'Vin d'Ay' should be called 'Vinum Dei'--The merits of the wine sung by poets and extolled by wits--The Ay wine in its palmy days evidently not sparkling--Arthur Young's visit to Ay in 1787--The establishment of Deutz & Geldermann--Drawing off the cuvée there--Mode of excavating cellars in the Champagne--The firm's new cellars, vineyards, and vendangeoir--M. Duminy's cellars and wines--The house founded in 1814--The new model Duminy establishment--Picturesque old house at Ay--Messrs. Pfungst Frères & Co.'s cellars--Their finely-matured dry Champagnes--The old church of Ay and its numerous decorations of grapes and vine-leaves--The sculptured figure above the Renaissance doorway--The Montebello establishment at Mareuil--The château formerly the property of the Dukes of Orleans--A titled Champagne firm--The brilliant career of Marshal Lannes--A promenade through the Montebello establishment--The press-house, the cuvée-vat, the packing-room, the offices, and the cellars--Portraits and relics at the château--The establishment of Bruch-Foucher & Co.--The handsome carved gigantic cuvée-tun--The cellars and their lofty shafts--The wines of the firm 217 XII. /Champagne Establishments at Avize and Rilly./ Avize the centre of the white grape district--Its situation and aspect--The establishment of Giesler & Co.--The tirage and the cuvée--Vin Brut in racks and on tables--The packing-hall, the extensive cellars, and the disgorging cellier--Bottle stores and bottle-washing machines--Messrs. Giesler's wine-presses at Avize and vendangeoir at Bouzy--Their vineyards and their purchases of grapes--Reputation of the Giesler brand--The establishment of M. Charles de Cazanove--A tame young boar--Boar-hunting in the Champagne--M. de Cazanove's commodious cellars and carefully-selected wines--Vineyards owned by him and his family--Reputation of his wines in Paris and their growing popularity in England--Interesting view of the Avize and Cramant vineyards from M. de Cazanove's terraced garden--The vintaging of the white grapes in the Champagne--Roper Frères' establishment at Rilly-la-Montagne--Their cellars penetrated by roots of trees--Some samples of fine old Champagnes--The principal Châlons establishments--Poem on Champagne by M. Amaury de Cazanove 229 XIII. /Sport in the Champagne./ The Champagne forests the resort of the wild-boar--Departure of a hunting-party in the early morning to a boar-hunt--Rousing the boar from his lair--Commencement of the attack--Chasing the boar--His course is checked by a bullet--The dogs rush on in full pursuit--The boar turns and stands at bay--A skilful marksman advances and gives him the _coup de grâce_--Hunting the wild-boar on horseback in the Champagne--An exciting day's sport with M. d'Honnincton's boar-hounds--The 'sonnerie du sanglier' and the 'vue'--The horns sound in chorus 'The boar has taken soil'--The boar leaves the stream, and a spirited chase ensues--Brought to bay, he seeks the water again--Deathly struggle between the boar and a full pack of hounds--The fatal shot is at length fired, and the 'hallali' is sounded--As many as fifteen wild-boars sometimes killed at a single meet--The vagaries of some tame young boars--Hounds of all kinds used for hunting the wild-boar in the Champagne--Damage done by boars to the vineyards and the crops--Varieties of game common to the Champagne 235 /Part III./ I. /Sparkling Saumur and Sparkling Sauternes./ The sparkling wines of the Loire often palmed off as Champagne--The finer qualities improve with age--Anjou the cradle of the Plantagenet kings--Saumur and its dominating feudal Château and antique Hôtel de Ville--Its sinister Rue des Payens and steep tortuous Grande Rue--The vineyards of the Coteau of Saumur--Abandoned stone-quarries converted into dwellings--The vintage in progress--Old-fashioned pressoirs--The making of the wine--Touraine the favourite residence of the earlier French monarchs--After a night's carouse at the epoch of the Renaissance--The Vouvray vineyards--Balzac's picture of La Vallée Coquette--The village of Vouvray and the Château of Moncontour--Vernou, with its reminiscences of Sully and Pépin-le-Bref--The vineyards around Saumur--Remarkable ancient Dolmens--Ackerman-Laurance's establishment at Saint-Florent--Their extensive cellars, ancient and modern--Treatment of the newly-vintaged wine--The cuvée--Proportions of wine from black and white grapes--The bottling and disgorging of the wine and finishing operations--The Château of Varrains and the establishment of M. Louis Duvau aîné--His cellars a succession of gloomy galleries--The disgorging of the wine accomplished in a melodramatic-looking cave--M. Duvau's vineyard--His sparkling Saumur of various ages--Marked superiority of the more matured samples--M. E. Normandin's sparkling Sauternes manufactory at Châteauneuf--Angoulême and its ancient fortifications--Vin de Colombar--M. Normandin's sparkling Sauternes cuvée--His cellars near Châteauneuf--Recognition accorded to the wine at the Concours Régional d'Angoulême 241 II. /The Sparkling Wines of Burgundy, the Jura, and the South of France./ Sparkling wines of the Côte d'Or at the Paris Exhibition of 1878--Chambertin, Romanée, and Vougeot--Burgundy wines and vines formerly presents from princes--Vintaging sparkling Burgundies--Their after-treatment in the cellars--Excess of breakage--Similarity of proceeding to that followed in the Champagne--Principal manufacturers of sparkling Burgundies--Sparkling wines of Tonnerre, the birthplace of the Chevalier d'Eon--The Vin d'Arbanne of Bar-sur-Aube--Death there of the Bastard de Bourbon--Madame de la Motte's ostentatious display and arrest there--Sparkling wines of the Beaujolais--The Mont-Brouilly vineyards--Ancient reputation of the wines of the Jura--The Vin Jaune of Arbois beloved of Henri Quatre--Rhymes by him in its honour--Lons-le-Saulnier--Vineyards yielding the sparkling Jura wines--Their vintaging and subsequent treatment--Their high alcoholic strength and general drawbacks--Sparkling wines of Auvergne, Guienne, Dauphiné, and Languedoc--Sparkling Saint-Péray the Champagne of the South--Valence, with its reminiscences of Pius VI. and Napoleon I.--The 'Horns of Crussol' on the banks of the Rhône--Vintage scene at Saint-Péray--The vines and vineyards producing sparkling wine--Manipulation of sparkling Saint-Péray--Its abundance of natural sugar--The cellars of M. de Saint-Prix, and samples of his wines--Sparkling Côte-Rotie, Château-Grillé, and Hermitage--Annual production and principal markets of sparkling Saint-Péray--Clairette de Die--The Porte Rouge of Die Cathedral--How the Die wine is made--The sparkling white and rose-coloured muscatels of Die--Sparkling wines of Vercheny and Lagrasse--Barnave and the royal flight to Varennes--Narbonne formerly a miniature Rome, now noted merely for its wine and honey--Fête of the Black Virgin at Limoux--Preference given to the new wine over the miraculous water--Blanquette of Limoux, and how it is made--Characteristics of this overrated wine 251 III. /Facts and Notes respecting Sparkling Wines./ Dry and sweet Champagnes--Their sparkling properties--Form of Champagne glasses--Style of sparkling wines consumed in different countries--The colour and alcoholic strength of Champagne--Champagne approved of by the faculty--Its use in nervous derangements--The icing of Champagne--Scarcity of grand vintages in the Champagne--The quality of the wine has little influence on the price--Prices realised by the Ay and Verzenay crus in grand years--Suggestions for laying down Champagnes of grand vintages--The improvement they develop after a few years--The wine of 1874--The proper kind of cellar in which to lay down Champagne--Advantages of Burrow's patent slider wine-bins--Increase in the consumption of Champagne--Tabular statement of stocks, exports, and home consumption from 1844-5 to 1877-8--When to serve Champagne at a dinner-party--Charles Dickens's dictum that its proper place is at a ball--Advantageous effect of Champagne at an ordinary British dinner-party 258 [Illustration] [Illustration: A HISTORY OF CHAMPAGNE] WITH NOTES ON OTHER SPARKLING WINES. PART I. I. /Early Renown of the Champagne Wines./ The vine in Gaul--Domitian's edict to uproot it--Plantation of vineyards under Probus--Early vineyards of the Champagne--Ravages by the Northern tribes repulsed for a time by the Consul Jovinus--St. Remi and the baptism of Clovis--St. Remi's vineyards--Simultaneous progress of Christianity and the cultivation of the vine--The vine a favourite subject of ornament in the churches of the Champagne--The culture of the vine interrupted, only to be renewed with increased ardour--Early distinction between 'Vins de la Rivière' and 'Vins de la Montagne'--A prelate's counsel respecting the proper wine to drink--The Champagne desolated by war--Pope Urban II., a former Canon of Reims Cathedral--His partiality for the wine of Ay--Bequests of vineyards to religious establishments--Critical ecclesiastical topers--The wine of the Champagne causes poets to sing and rejoice--'La Bataille des Vins'--Wines of Auviller and Espernai le Bacheler. [Illustration] Although the date of the introduction of the vine into France is lost in the mists of antiquity, and though the wines of Marseilles, Narbonne, and Vienne were celebrated by Roman writers prior to the Christian era, many centuries elapsed before a vintage was gathered within the limits of the ancient province of Champagne. Whilst the vine and olive throve in the sunny soil of the Narbonnese Gaul, the frigid climate of the as yet uncultivated North forbade the production of either wine or oil.[1] The 'forest of the Marne,' now renowned for the vintage it yields, was then indeed a dark and gloomy wood, the haunt of the wolf and wild boar, the stag and the auroch; and the tall barbarians of Gallia Comata, who manned the walls of Reims on the approach of Cæsar, were fain to quaff defiance to the Roman power in mead and ale.[2] Though Reims became under the Roman dominion one of the capitals of Belgic Gaul, and acquired an importance to which numerous relics in the shape of temples, triumphal arches, baths, arenas, military roads, &c., amply testify; and though the Gauls were especially distinguished by their quick adoption of Roman customs, it appears certain that during the sway of the twelve Cæsars the inhabitants of the present Champagne district were forced to draw the wine, with which their amphoræ were filled and their pateræ replenished, from extraneous sources. The vintages of which Pliny and Columella have written were confined to Gallia Narboniensis, though the culture of the vine had doubtless made some progress in Aquitaine and on the banks of the Saône, when the stern edict of the fly-catching madman Domitian, issued on the plea that the plant of Bacchus usurped space which would be better filled by that of Ceres, led (/A.D./ 92) to its total uprooting throughout the Gallic territory. [Illustration] For nearly two hundred years this strange edict remained in force, during which period all the wine consumed in the Gallo-Roman dominions was imported from abroad. Six generations of men, to whom the cheerful toil of the vine-dresser was but an hereditary tale, and the joys of the vintage a half-forgotten tradition, had passed away when, in 282, the Emperor Probus, a gardener's son, once more granted permission to cultivate the vine, and even exercised his legions in the laying-out and planting of vineyards in Gaul.[3] The culture was eagerly resumed, and, as with the advancement of agriculture and the clearance of forests the climate had gradually improved, the inhabitants of the more northern regions sought to emulate their southern neighbours in the production of wine. This concession of Probus was hailed with rejoicing; and some antiquaries maintain that the triumphal arch at Reims, known as the Gate of Mars, was erected during his reign as a token of gratitude for this permission to replant the vine.[4] [Illustration] [Illustration: THE GATE OF MARS AT REIMS.] By the fourth century the banks of the Marne and the Moselle were clothed with vineyards, which became objects of envy and desire to the yellow-haired tribes of Germany,[5] and led in no small degree to the predatory incursions into the territory of Reims so severely repulsed by Julian the Apostate and the Consul Jovinus, who had aided Julian to ascend the throne of the Cæsars, and had combatted for him against the Persians. Julian assembled his forces at Reims in 356, before advancing against the Alemanni, who had established themselves in Alsace and Lorraine; and ten years later the Consul Jovinus, after surprising some of the same nation bathing their large limbs, combing their long and flaxen hair, and 'swallowing huge draughts of rich and delicious wine,'[6] on the banks of the Moselle, fought a desperate and successful battle, lasting an entire summer's day, on the Catalaunian plains near Châlons, with their comrades, whom the prospect of similar indulgence had tempted to enter the Champagne. Valerian came to Reims in 367 to congratulate Jovinus; and the Emperor and the Consul (whose tomb is to-day preserved in Reims Cathedral) fought their battles o'er again over their cups in the palace reared by the latter on the spot occupied in later years by the church of St. Nicaise. The check administered by Jovinus was but temporary, while the attraction continued permanent. For nearly half a century, it is true, the vineyards of the Champagne throve amidst an era of quiet and prosperity such as had seldom blessed the frontier provinces of Gaul.[7] But when, in 406, the Vandals spread the flame of war from the banks of the Rhine to the Alps, the Pyrenees, and the ocean, Reims was sacked, its fields ravaged, its bishop cut down at the altar, and its inhabitants slain or made captive; and the same scene of desolation was repeated when the hostile myriads of Attila swept across north-western France in 451. [Illustration: TOMB OF THE CONSUL JOVINUS, PRESERVED IN REIMS CATHEDRAL.] Happier times were, however, in store for Reims and its bishops and its vineyards, the connection between the two last being far more intimate than might be supposed. When Clovis and his Frankish host passed through Reims by the road still known as the Grande Barberie, on his way to attack Syagrius in 486, there was no doubt a little pillaging, and the famous golden vase which one of the monarch's followers carried off from the episcopal residence was not left unfilled by its new owner. But after Syagrius had been crushed at Soissons, and the theft avenged by a blow from the king's battle-axe, Clovis not only restored the stolen vase, and made a treaty with the bishop St. Remi or Remigius, son of Emilius, Count of Laon, but eventually became a convert to Christianity, and accepted baptism at his hands. Secular history has celebrated the fight of Tolbiac--the invocation addressed by the despairing Frank to the God of the Christians; the sudden rallying of his fainting troops, and the last desperate charge which swept away for ever the power of the Alemanni as a nation. Saintly legends have enlarged upon the piety of Queen Clotilda; the ability of St. Remi; the pomp and ceremony which marked the baptism of Clovis at Reims in December 496; the memorable injunction of the bishop to his royal convert to adore the cross he had burnt, and burn the idols he had hitherto adored; and the miracle of the Sainte Ampoule, a vial of holy oil said to have been brought direct from heaven by a snow-white dove in honour of the occasion. A pigeon, however, has always been a favourite item in the conjuror's paraphernalia from the days of Apolonius of Tyana and Mahomet down to those of Houdin and Dr. Lynn; and modern scepticism has suggested that the celestial regions were none other than the episcopal dovecot. Whether or not the oil was holy, we may be certain that the wine which flowed freely in honour of the Frankish monarch's conversion was ambrosial; that the fierce warriors who had conquered at Soissons and Tolbiac wetted their long moustaches in the choicest growths that had ripened on the surrounding hills; and that the Counts and Leudes, and, judging from national habits, the King himself, got royally drunk upon a _cuvée réservée_ from the vineyard which St. Remi had planted with his own hands on his hereditary estate near Laon, or the one which the slave Melanius cultivated for him just without the walls of Reims. [Illustration] For the saint was not only a converter of kings, but, what is of more moment to us, a cultivator of vineyards and an appreciator of their produce. Amongst the many miracles which monkish chroniclers have ascribed to him is one commemorated by a bas-relief on the north doorway of Reims Cathedral, representing him in the house of one of his relatives, named Celia, making the sign of the cross over an empty cask, which, as a matter of course, immediately became filled with wine. That St. Remi possessed such an ample stock of wine of his own as to have been under no necessity to repeat this miracle in the episcopal palace is evident from the will penned by him during his last illness in 530, as this shows his viticultural and other possessions to have been sufficiently extensive to have contented a bishop even of the most pluralistic proclivities.[8] It is curious to note the connection between the spread of viticulture and that of Christianity--a connection apparently incongruous, and yet evident enough, when it is remembered that wine is necessary for the celebration of the most solemn sacrament of the Church. Christianity became the established religion of the Roman Empire about the first decade of the fourth century, and Paganism was prohibited by Theodosius at its close; and it is during this period that we find the culture of the grape spreading throughout Gaul, and St. Martin of Tours preaching the Gospel and planting a vineyard coevally. Chapters and religious houses especially applied themselves to the cultivation of the vine, and hence the origin of many famous vineyards, not only of the Champagne but of France. The old monkish architects, too, showed their appreciation of the vine by continually introducing sculptured festoons of vine-leaves, intermingled with massy clusters of grapes, into the decorations of the churches built by them. The church of St. Remi, for instance, commenced in the middle of the seventh century, and touched up by succeeding builders till it has been compared to a school of progressive architecture, furnishes an example of this in the mouldings of its principal doorway; and Reims Cathedral offers several instances of a similar character. [Illustration] [Illustration: FROM THE NORTH DOORWAY OF REIMS CATHEDRAL.] Amidst the anarchy and confusion which marked the feeble sway of the long-haired Merovingian kings, whom the warlike Franks were wont to hoist upon their bucklers when investing them with the sovereign power, we find France relapsing into a state of barbarism; and though the Salic law enacted severe penalties for pulling up a vine-stock, the prospect of being liable at any moment to a writ of ejectment, enforced by the aid of a battle-axe, must have gone far to damp spontaneous ardour as regards experimental viticulture. The tenants of the Church, in which category the bulk of the vine-growers of Reims and Epernay were to be classed, were best off; but neither the threats of bishops nor the vengeance of saints could restrain acts of sacrilege and pillage. During the latter half of the sixth century Reims, Epernay, and the surrounding district were ravaged several times by the contending armies of Austrasia and Neustria; and Chilperic of Soissons, on capturing the latter town in 562, put such heavy taxes on the vines and the serfs that in three years the inhabitants had deserted the country. Matters improved, however, during the more peaceful days of the ensuing century, which witnessed the foundation of numerous abbeys, including those of Epernay, Hautvillers, and Avenay; and the planting of fresh vineyards in the ecclesiastical domains by Bishop Romulfe and his successor St. Sonnace, the latter, who died in 637, bequeathing to the church of St. Remi a vineyard at Villers, and to the monastery of St. Pierre les Dames one situate at Germaine, in the Mountain of Reims.[9] The sculptured saint on the exterior of Reims Cathedral, with his feet resting upon a pedestal wreathed with vine-leaves and bunches of grapes, may possibly have been intended for one of these numerous wine-growing prelates. [Illustration: FROM THE NORTH DOORWAY OF REIMS CATHEDRAL.] The mighty figure of Charlemagne, overshadowing the whole of Europe at the commencement of the ninth century, appears in connection with Reims, where, begirt with paladins and peers, he entertained the ill-used Pope Leo III. right royally during the 'festes de Noel' of 805. The monarch who is said to have clothed the steep heights of Rudesheim with vines was not indifferent to good wine; and the vintages of the Champagne doubtless mantled in the magic goblet of Huon de Bordeaux, and brimmed the horns which Roland, Oliver, Doolin de Mayence, Renaud of Montauban, and Ogier the Dane, drained before girding on their swords and starting on their deeds of high emprise--the slaughter of Saracens, the rescue of captive damsels, and the discomfiture of felon knights--told in the fables of Turpin and the 'chansons de geste.' That the cultivation of the grape, and above all the making of wine, had been steadily progressing, is clear from the fact that the distinction between the 'Vins de la Rivière de Marne' and the 'Vins de la Montagne de Reims' dates from the ninth century.[10] This era is, moreover, marked by the inauguration of that long series of coronations which helped to spread the popularity of the Champagne wines throughout France by the agency of the nobles and prelates taking part in the ceremony. Sumptuous festivities marked the coronation of Charlemagne's son Louis in 816; and the officiating Archbishop Ebbon may have helped to furnish the feast with some of the produce from the vineyard he had planted at Mont Ebbon, generally identified with the existing Montebon, near Mardeuil. It is of this vineyard that Pardulus, Bishop of Laon, speaks in a letter addressed by him to Ebbon's successor, the virtuous Hincmar, who assumed the crozier in 845, proffering him counsels as to the best method of sustaining his failing health. After telling him to avoid eating fish on the same day that it is caught, insisting that salted meat is more wholesome than fresh, and recommending bacon and beans cooked in fat as an excellent digestive, he proceeds: 'You must make use of a wine which is neither too strong nor too weak--prefer, to those produced on the summit of the mountain or the bottom of the valley, one that is grown on the slopes of the hills, as towards Epernay, at Mont Ebbon; towards Chaumuzy, at Rouvesy; towards Reims, at Mersy and Chaumery.' The Champagne vineyards suffered grievously from the internal convulsions which marked the period when the sceptre of France was swayed by the feeble hands of the dregs of the Carlovingian race. The Normans, who threatened Reims and sacked Epernay in 882, swept over them like devouring locusts; and their annals during the following century are written in letters of blood and flame. Times were indeed bad for the peaceful vine-dressers in the tenth century, when castles were springing up in every direction; when might made right, and the rule of the strong hand alone prevailed; and when the firm belief that the end of the world was to come in the year 1000 led men to live only for the present, and seek to get as much out of their fellow-creatures as they possibly could. Such natural calamities as that of 919, when the wine-crop entirely failed in the neighbourhood of Reims, were bad enough; but the continual incursions of the Hungarians, whose arrows struck down the peasant at the plough and the priest at the altar, and the memory of whose pitiless deeds yet survives in the term 'ogre;' the desperate contest waged for ten years by Heribert of Vermandois to secure the bishopric of Reims for his infant son, during which hardly a foot of the disputed territory remained unstained by blood; the repeated invasions of Otho of Germany; and the struggle between Hugh Capet and Charles of Lorraine for the titular crown of France,--left traces harder to be effaced. Reims underwent four sieges in about sixty years; and Epernay, that most hapless of towns, was sacked at least half a score of times, and twice burnt, one of the most conscientiously executed pillagings being that performed in 947 by Hugh the Great, who, as it was vintage-time, completely ravaged the whole country, and carried off all the wine.[11] Under the rule of the Capetian race matters improved as regarded foreign foes, though the archbishops had in the early part of the eleventh century to abandon Epernay, Vertus, Fismes, and their dependencies to the family of Robert of Vermandois, who had assumed the title of Counts of Champagne, to be held by them as fiefs. The fame of the schools of Reims, where future popes and embryo emperors met as class-mates; the festive gatherings which marked the coronation of Henry I. and Philip I.; the great ecclesiastical council held by Leo IX., which procured for the city the nickname of 'little Rome;' and the growing importance of the Champagne fairs, the great meeting-places throughout the Middle Ages of the merchants of Spain, Italy, and the Low Countries,--favoured the prosperity of the district and the production of its wine. Urban II., a native of Châtillon, who wore the triple crown from 1088 to the close of the century, was, prior to his elevation to the chair of St. Peter, a canon of Reims, under the name of Eudes or Odo, and, tippling there in company with his fellow-clerics, acquired a taste for the wine of Ay, which he preferred to all others in the world.[12] Pilgrims to Rome found penance light and pardon easily obtained when they bore with them across the Alps, in addition to staff and scrip, a huge 'leathern bottel' of that beloved vintage which warmed the pontiff's heart and whetted his wit for the delivery of those soul-stirring orations at Placentia and Clermont, wherein he appealed to the chivalry of Western Europe to hasten to the rescue of the Holy Sepulchre from the hands of the infidel. The result of these appeals was felt by the vine-cultivators of the Champagne in more ways than one, and their case recalls that of the petard-hoisted engineer. The virtuous, the speculative, and the enthusiastic who followed Peter the Hermit and Walter the Penniless to the plains of Asia Minor suffered at the hands of the vicious, the prudent, and the practical, who remained at home and passed their time in pillaging the estates of their absent neighbours. The abbatial vineyards suffered like the others; and the monks of St. Thierry, in making peace with Gerard de la Roche and Alberic Malet in 1138, complained bitterly of wine violently extorted during two years from growers on the ecclesiastical estate and of a levy made upon their vineyard.[13] The efforts of Henry of France, a warlike prelate, who built fortresses and attacked those of the robber-nobles, and of Louis VII., who avenged the wrongs of the church of Reims on the Counts of Roucy, served to improve matters; and we may be sure that whenever the monks did get hold of a repentant or dying sinner, they made him pay pretty dearly for peace with them and Heaven. Colin Musset, the early Champenois poet, thought that the best use to which money could be put was to spend it in good wine.[14] Churchmen, however, managed to secure the desired commodity without any such outlay, for numerous charters of the twelfth and thirteenth centuries show lords, sick or about starting for the crusades, making large gifts to abbeys and monasteries; and many a strip of fair and fertile vineland was thus added, thanks to a judicious pressure on the conscience, to the already extensive possessions of the two great monasteries of Reims, St. Remi and St. Nicaise, and also to that of St. Thierry. The Templars, too, whose reputation as wine-bibbers was only inferior to that of the monks, if we may credit the adage which runs, 'Boire en templier, c'est boire à plein gosier; Boire en cordelier, c'est vuider le cellier,' and who, prior to the catastrophe of 1313, had a commandery at Reims, possessed either vineyards, or _droits de vinage_, at numerous spots, including Epernay, Hermonville, Ludes, and Verzy; while the separate community of these 'Red Monks' installed at Orilly had estates at Ay, Damery, and Mareuil. The hospital of St. Mary at Reims also reckoned amongst its possessions vineyards at Moussy, bequeathed by Canon Pontius and Tebaldus Papelenticus. The wine, which in 1215 the treasurer of the chapter of Reims Cathedral obtained from that body an acknowledgment of his right to on the anniversaries of the deaths of Bishops Ebalus and Radulf, and that to which the sub-treasurer and carpenter were severally entitled, was no doubt in part derived from the vineyard planted in 1206 by Canon Giles at the Porte Mars and bequeathed by him to the chapter, and the one which Canon John de Brie had purchased at Mareuil and had similarly bequeathed.[15] Although papal bulls and archiepiscopal warrants had forbidden the levying of the _droit de vinage_ on wine vintaged by religious communities, in 1252 Pope Innocent IV. had to reprove the barons for interfering with the monastic vintages in the neighbourhood of Reims, and to threaten them with excommunication if they repeated their offence.[16] [Illustration: VINE-DRESSERS--THIRTEENTH CENTURY (From a window of Chartres Cathedral).] These ecclesiastical topers, as a rule, were sufficiently critical of the quality of the liquor meted out to them, and an agreement respecting the dietary of the Abbey of St. Remi, at Reims, drawn up in 1218 between the Abbot Peter and a deputation of six monks representing the rest of the brethren, provides that the wine procured for the latter should be improved by two-thirds of the produce of the Clos de Marigny being set apart for their exclusive use. Ten years later, to put a stop to further complaints on the part of these worthy rivals of Rabelais' Frère Jean des Entonnoirs, Abbot Peter was fain to agree that two hundred hogsheads of wine should be annually brought from Marigny to the abbey to quench the thirst of his droughty flock, and that if the spot in question failed to yield the required amount the deficiency should be made up from his own private and particular vineyards at Sacy, Villers-Aleran, Chigny, and Hermonville.[17] We can readily picture these 'jolly fat friars Sitting round the great roaring fires With their strong wines;' or the cellarer quietly chuckling to himself as he loosened the spiggot of the choicest casks-- 'Between this cask and the abbot's lips Many have been the sips and slips; Many have been the draughts of wine, On their way to his, that have stopped at mine.' [Illustration: GATEWAY OF THE CHAPTER COURT AT REIMS.] The monks were in the habit of throwing open their monasteries to all comers, under pretext of letting them taste the wine they had for sale, until, in 1233, an ecclesiastical council at Beziers prohibited this practice on account of the scandal it created. Petrarch has accused the popes of his day of persisting in staying at Avignon when they could have returned to Rome, simply on account of the goodness of the wines they found there. Some similar reasons may have led to the selection of Reims, during the twelfth century, as a place for holding great ecclesiastical councils presided over by the sovereign pontiff in person; and no doubt 'Bibimus papaliter' was the motto of Calixtus, Innocent, and Eugenius when the labours of the day were done, and they and their cardinals could chorus, _apropos_ of those of the morrow, 'Bonum vinum acuit ingenium Venite potemus.' [Illustration] The kings of France may have preferred the wines of the Orleanais and the Isle of France, and the monarchs of England have been content to vary the vintages of their patrimony of Guienne with an occasional draught of Rhenish; but the wines of the river Marne certainly found favour at Troyes, where the Counts of Champagne, to whom Epernay had been ceded as a fief, held a court little inferior in state to that of a sovereign prince. The native vintage mantled in the goblets and beakers that graced the board where they sat at meat amidst their knights and barons, whilst minstrels sang and jongleurs tumbled and glee-maidens danced at the lower end of the hall. It fired the fancy of the poet Count Thibault, to whom tradition has ascribed the introduction of the Cyprus grape into France on his return from the Crusades,[18] and helped the flow of the amorous strains which he addressed to Blanche of Castille. Nor was he the only versifier of the time who could exclaim, with his compatriot Colin Musset, that 'good wine caused him to sing and rejoice.'[19] Other local songsters, such as Doete de Troyes, Eustache le Noble, and Guillaume de Machault, sought inspiration at their native Helicon, and were equally ready with Colin Musset to appreciate a gift of 'barrelled wine, Cold, strong, and fine, To drink in hot weather,'[20] in return for their rhymes. It was this wine that the gigantic John Lord of Joinville, Seneschal of Champagne under Thibault, and chronicler of the Seventh Crusade, was in the habit of consuming warm and undiluted, by the advice of his physicians, on account, as he himself mentions, of his 'large head and cold stomach;' a practice which seems to have scandalised that pious and ascetic monarch St. Louis, who was careful to temper his own potations with water. The king was most likely not unacquainted with the wine, as a roll of the expenses incurred at his coronation at Reims, in 1226, shows that 991 livres were spent in wine on that occasion, when, in consequence of the vacancy of the archiepiscopal see, the crown was placed upon his head by Jacques de Bazoche, Bishop of Soissons. [Illustration] Henry of Andelys, a compatriot of the engineer Brunel, who flourished, if a poet can be said to flourish, in the latter half of the thirteenth century, has extolled the wines of Epernay and Hautvillers, and mentioned that of Reims, in his poem entitled the 'Bataille des Vins.' He informs us at the outset that 'the great King Philip Augustus,' whom state records prove to have had a score of vineyards in different parts of France,[21] was very fond of 'good white wine.' Anxious to make a choice of the best, he issued invitations to all the most renowned _crûs_, French and foreign, and forty-six different vintages responded to this appeal; amongst them Hautvillers and Epernay, described as 'vin d'Auviler' and 'vin d'Espernai le Bacheler.' The king's chaplain, an English priest, makes a preliminary examination, resulting in the summary rejection of many competitors, till at length, as Argenteuil--'clear as oil'--and Pierrefitte are disputing as to their respective merits, Epernay and Hautvillers simultaneously exclaim, 'Argenteuil, thou wishest to degrade all the wines at this table. By God, thou playest too much the part of constable. We excel Châlons and Reims, remove gout from the loins, and support all kings.'[22] But lo, up jumps the 'vin d'Ausois,' the 'Osey' of so many of our English mediæval poets, with the reproach, 'Epernay, thou art too disloyal; thou hast not the right of speaking in court;'[23] and enumerates the blessings which he and his demoiselle 'la Mosele' confer upon the Germans.[24] La Rochelle in turn reproves Ausois, and extols the strength of his own wines, and those of Angoulême, Bordeaux, Saintes, and Poitou, and boasts of the welcome accorded to them in the northern states of Europe, including England, to which the districts he mentions then belonged.[25] [Illustration: VINTAGERS OF THE THIRTEENTH CENTURY (From a /MS./ of the Dialogues de St. Grégoire).] The vintages of the then little kingdom of France put in a counter-claim for finesse and flavour as opposed to strength, and maintain that they do not harm those who drink them. The dispute becomes general, and the wines, heated with argument, exhale a perfume of 'balsam and amber,' till the hall where they are met resembles a terrestial paradise. The chaplain, after conscientiously tasting the whole of them, formally excommunicated with bell, book, and candle all the beer brewed in England and Flanders, and then went incontinently to bed, and slept for three days and three nights without intermission. The king thereupon made an examination himself, and named the wine of Cyprus pope, and that of Aquilat[26] cardinal, and created of the remainder three kings, five counts, and twelve peers, the names of which, unfortunately, have not been preserved. [Illustration] II. /The Wines of the Champagne from the Fourteenth to the Seventeenth Century./ Coronations at Reims and their attendant banquets--Wine flows profusely at these entertainments--The wine-trade of Reims--Presents of wine from the Reims municipality--Cultivation of the vineyards abandoned after the battle of Poitiers--Octroi levied on wine at Reims--Coronation of Charles V.--Extension of the Champagne vineyards--Abundance of wine--Visit to Reims of the royal sot Wenceslaus of Bohemia--The Etape aux Vins at Reims--Increased consumption of beer during the English occupation of the city--The Maid of Orleans at Reims--The vineyards and wine-trade alike suffer--Louis XI. is crowned at Reims--Fresh taxes upon wine followed by the Mique-Maque revolt--The Rémois the victims of pillaging foes and extortionate defenders--The Champagne vineyards attacked by noxious insects--Coronation of Louis XII.--François Premier, the Emperor Charles V., Bluff King Hal, and Leo the Magnificent all partial to the wine of Ay--Mary Queen of Scots at Reims--State kept by the opulent and libertine Cardinal of Lorraine--Brusquet, the Court Fool--Decrease in the production of wine around Reims--Gifts of wine to newly-crowned monarchs--New restrictions on vine cultivation--The wine of the Champagne crowned at the same time as Louis XIII.--Regulation price for wine established at Reims--Imposts levied on the vineyards by the Frondeurs--The country ravaged around Reims--Sufferings of the peasantry--Presents of wine to Marshal Turenne and Charles II. of England--Perfection of the Champagne wines during the reign of Louis XIV.--St. Evremond's high opinion of them--Other contemporary testimony in their favour--The Archbishop of Reims's niggardly gift to James II. of England--A poet killed by Champagne--Offerings by the Rémois to Louis XIV. on his visit to their city. [Illustration] The coronations at Reims served, as already remarked, to attract within the walls of the old episcopal city all that was great, magnificent, and noble in France. The newly-crowned king, with that extensive retinue which marked the monarch of the Middle Ages; the great vassals of the crown scarcely less profusely attended; the constable, the secular and ecclesiastical peers, and the host of knights and nobles who assisted on the occasion, were wont at the conclusion of the ceremony to hold high revelry in the spacious temporary banqueting-hall reared near the cathedral. It is to be regretted that the _menus_ of these banquets have not been handed down to us in their entirety; but a few fragmentary excerpts show that from a comparatively early period there was no lack of wine, at any rate. A remonstrance addressed to Philip the Fair, after his coronation in 1286, by the archbishop and burghers, asks that they may be relieved of a certain proportion of the sum levied on them for the cost of the ceremony, on the ground that there still remained over for the king's use no less than seven score tuns of wine from the banquet. Some idea may be formed of the quantity of wine brought regularly into the city from the circumstance of the king having Reims surrounded by walls in 1294, and levying a duty on the wine imported to pay for them, and by the value attached to the 'rouage'[27] of the Mairie St. Martin, claimed by the chapter of Reims Cathedral in 1300. [Illustration: REIMS CATHEDRAL, WEST FRONT.] At the coronation of Charles IV., in 1322, wine flowed in rivers. Amongst the unconsumed provisions returned by the king's pantler, Pelvau dou Val, to the burghers, 'vin de Biaune et de Rivière'--that is, of Beaune and of the Marne--figures for a value of 384 livres 5 sols 2 deniers.[28] The arrangements of the coronation had been intrusted to the minister of finances, Pierre Remi, who certainly played the part of the unjust steward. In the first place, he made the cost of the ceremony amount to 21,000 livres, whereas none of his predecessors had spent more than 7,000 livres. His opening move had been to seize upon the greater part of the corn and all the ovens in Reims 'for the king's use,' and to sell bread to the townsfolk and visitors at his own price for a fortnight prior to the coronation. After the ceremony he appropriated in like manner all the plate and napery, and all the cooking utensils and kitchen furniture, together with whatever had been left over, in the shape of wine, wax, fish, bullocks, pigs, and similar trifles. The wine thus taken was estimated at 1500 livres, part of which he sold to two bourgeois of Reims, and kept the rest, together with forty-four out of the fifty muids, or hogsheads, of salt provided.[29] Retributive justice overtook him, for the chronicler of his ill-doings chuckles over the fact that he was hanged as high as Haman on a gibbet he had himself erected at Paris. Things went off better at the coronation of King Philip, in 1328, when the total amount expended in the three hundred poinçons of the wine of Beaune, St. Pourçain, and the Marne consumed was 1675 livres 2 sols 3 deniers.[30] Part of this flowed through the mouth of the great bronze stag before which criminals condemned by the archiepiscopal court used to be exposed, but which at coronation times was placed in the Parvis Notre Dame, and spouted forth the 'claré dou cerf,' for the preparation of which the town records show that the grocer O. la Lale received 16 livres.[31] [Illustration] The importance of the wine-trade of Reims at the commencement of the fourteenth century is evidenced by the fact of there being at this epoch _courtiers de vin_, or wine-brokers, the right of appointing whom rested with the eschevins--a right which, vainly assailed by the archbishop in 1323, was confirmed to the municipal power by several royal decrees.[32] The burghers of Reims were fully cognisant of the merits of their wine, and certainly spared no trouble to make others acquainted with them. When the eschevins dined with the archbishop in August 1340 they contributed thirty-two pots of wine as their share of the repast, in addition to sundry partridges, capons, and rabbits. All visitors to the town on business, and all persons of distinction passing through it, were regaled with an offering of from two to four gallons from the cellars of Jehan de la Lobe, or Petit Jehannin, or Raulin d'Escry, or Baudouin le Boutellier, or Remi Cauchois, the principal tavern-keepers. The provost of Laon, the bailli and the receveur of Vermandois, the eschevins of Châlons, the Bishop of Coustances, Monseigneur Thibaut de Bar, Monseigneur Jacques la Vache (the queen's physician), the Archdeacon of Reims, and the 'two lords of the parliament deputed by the king to examine the walls,' were a few of the recipients of this hospitality, which was also extended to such inferior personages as a varlet of Verdun and the varlet of the eschevins of Abbeville. [Illustration: THE BATTLE OF CRÉCY (From a /MS./ of Froissart's Chronicles).] Two 'flasks,' purchased for threepence-halfpenny from Petit Jehannin, served to warm the eloquence of Maistre Baudouin de Loingnis when he pleaded for the town on the subject of the fortifications in 1345; and when, in 1340, the Archbishop of Narbonne, the Bishop of Poitiers, and sundry other dignitaries passed through Reims with heavy hearts on their way to St. Omer, to negotiate a truce with Edward of England after the fatal battle of Sluys, the municipality expended five shillings and threepence in a poinçon of wine to cheer them on their way. There was probably plenty to spare, since on the outbreak of hostilities with England the town-crier had received one penny for making proclamation that no one should remove any wine from the town during the continuance of the contest. The advent of a messenger of Monseigneur Guillaume Pinson, who brought 'closed letters' to the eschevins informing them of the invasion of King Edward, does not seem to have spoilt the digestion of those worthy gentlemen, since they partook of their annual gift of wine and their presentation lamb at Easter 1346; but there were sore hearts in the old city when one Jenvier returned from Amiens with the tidings that their best and bravest had fallen under the banner of John de Vienne, their warlike prelate, on the field of Crécy. Perhaps to the state of depression that followed is due the fact that there are no records of festivities at the coronation of King John the Good in 1350, though we find the citizens seeking two years later to propitiate the evil genius of France, Charles the Bad of Navarre, by the gift of a queue of wine costing five crowns. During the frightful anarchy prevailing after the battle of Poitiers, when the victorious English and the disbanded forces of France made common cause against the hapless peasants, the fields and vineyards of Reims remained uncultivated for three years,[33] and the people of the archbishopric would have perished of hunger had they not been able to get food and wine from Hainault. Despite the prohibitions of the regent, the nobles pillaged the country around Reims and ravaged the vineyards from June to August 1358, and the havoc they wrought exceeded even that accomplished during the Jacquerie. Nor were matters improved by the advent of the English king, Edward III., when, on the wet St. Andrew's-day of 1359, he sat down before the town with his host, which starved and shivered throughout the bitter and tempestuous winter, despite the comfort derived from the 'three thousand vessels of wine' captured by Eustace Dabreticourt in 'the town of Achery, on the river of Esne.'[34] But the Rémois stood firm behind the fortifications reared by Gaucher de Châtillon till the following spring, when the victor of Crécy drew off his baffled forces, consoling them with the promise of bringing them back during the ensuing vintage, and made a reluctant peace at Bretigny.[35] [Illustration: ANCIENT TOWER BELONGING TO THE FORTIFICATIONS OF REIMS.] Yet, though plague and famine in turn almost depopulated the city, the importance of its vineyards augmented from this time forward. In 1361 the citizens, who had already been in the habit of granting 'aides' to the king out of the dues levied on the wine sold in the town, obtained leave to impose an _octroi_ on wine, in order to maintain their fortifications. Henceforward the connection between the wines and the walls of Reims became permanent. The _octroi_ was from time to time renewed or modified in various ways by different monarchs; but their decrees always commenced with a preliminary flourish concerning the necessity of keeping the walls of so important a city in good order, and the admirable opportunity afforded of so doing by the ever-increasing prosperity of the trade in wine. Conspicuous amongst the few existing fragments of the circuit of walls and towers with which Reims was formerly begirt is the tower of which a view is here given.[36] The Rémois, although willing enough to tax themselves for the defence of their city, submitted the reverse of cheerfully to the preliminary levies of provisions, wines, meats, and other things necessary, made by the king's 'maistres d'hôtel' for the coronation of Charles V., which took place on the 19th May 1364, at a cost to the town of 7712 livres 15 sols 5 deniers parisis.[37] The citizens had, however, something to gaze at for their money, if that were any consolation. The king and his queen (Jeanne de Bourbon) were accompanied by King Peter of Cyprus; Wenceslaus, King of Bohemia and Duke of Brabant; the Dukes of Burgundy and Anjou; the Counts of Eu, Dampmartin, Tancarville, and Vaudemont, and many other prelates and lords, who did full justice to the good cheer provided for the great feasts and solemnities taking place during the five days of the royal sojourn.[38] The crown, borne by Philip of Burgundy, the king's youngest brother, having been placed upon Charles's head by the Archbishop Jean de Craon, that prelate proceeded to smear the royal breast and brow with what the irreverent Republicans of the eighteenth century designated 'sacred pomatum,' from the Sainte Ampoule presented to him by the Bishop of Laon, amidst the enthusiastic applause of nobles and prelates.[39] [Illustration: CORONATION OF CHARLES V. AT REIMS (From a /MS./ Histoire de Charles V.).] The great planting of vines in the Champagne district plainly dates from the last quarter of the fourteenth century, at which epoch large exports of wine to the provinces of Hainault and Flanders, and especially to the ports of Sluys, are noted. In a list of the revenues of the archbishopric of Reims, drawn up by Richard Pique towards 1375, are included patches of vineland and annual payments of wine from almost every village and hamlet within twenty miles of Reims; though it is only fair to mention that many of the places enumerated produce to-day wines of very ordinary character, which, although they have a local habitation, have certainly failed to secure themselves a name.[40] A general return of church property made to the Bailli of Vermandois, the king's representative in 1384, at a time when Charles VI. was busily engaged in confiscating whatever he could lay hands on, shows that the religious establishments of Reims were equally well endowed with vineyards. These were mostly situate to the north-east and south-west of Reims, or in the immediate vicinity of the city; and according to their owners, whose object was of course to offer as few temptations as possible to the monarch, they frequently cost more to dress than they brought in.[41] In the return furnished by the archbishop in the following year, he complains that, owing to the great plantation of vines throughout the district, the right of licensing the brewing of ale and beer had failed to bring him in any revenue for the past three years. This prelate, by the way, seems to have loved his liquor like many of his predecessors, judging from the inventory made after his death, in 1389, of the contents of his cellars.[42] All this abundance of wine was not without its fruits; and we find the clerk of Troyes asserting that liars swarm in Picardy as drunkards do in Champagne, where a man not worth a rap will drink wine every day;[43] and a boast in the chanson of the Comte de Brie to the effect that the province abounded in wheat, wine, fodder, and litter.[44] Under these circumstances it is not at all surprising that that renowned vinous soaker, King Wenceslaus (surnamed the Drunkard) of Bohemia, found ample opportunities for self-indulgence when he visited Reims to confer with Charles VI. on the subject of the schism of the popes of Avignon, then desolating the Church--certainly a very fit subject for a drunkard and a madman to put their heads together about. No sooner had the illustrious visitor alighted at the Abbey of St. Remi--to-day the Hôtel Dieu--where quarters had been assigned him, than he expressed a wish to taste the wine of the district, with the quality of which he had long been acquainted. The wine was brought, and tasted again and again in such conscientious style that when the Dukes of Bourbon and Berri came to escort him to dinner with the king they found him dead-drunk and utterly unfit to treat of affairs of State, still less those of the Church. The same kind of thing went on daily--the 'same old drunk,' as the nigger expressed it, lasting week after week; and the French monarch, who must have surely had a lucid interval, resolved to profit by his guest's weakness. Accordingly he gave special orders to the cup-bearers, at a grand banquet at which matters were to be finally settled, to be particularly attentive in filling the Bohemian king's goblet. This they did so frequently that the royal sot, overcome by wine, yielded during the discussion following the repast whatever was asked of him; whilst his host probably returned special thanks to St. Archideclin, the supposed bridegroom of the marriage of Cana, whom the piety of the Middle Ages had transformed into a saint and created the especial patron of all appertaining to the cellar. This triumph of wine over diplomacy occurred in 1397.[45] A charter of Charles VI., dated July 1412, which gave the municipal authorities of Reims the sole right of appointing sworn wine-brokers, expressly mentions that the trade of the town was chiefly based upon the wine grown in the environs.[46] The wine, the charter states, when stored in the cellars of the town, was customarily sold by brokers, who of their own authority were in the habit of levying a commission of twopence, and even more, per piece, selling it to the person who offered them most, and taking money from both buyer and seller. To remedy this state of things, from which it was asserted the trade had begun to suffer, it was decreed that every broker should take an oath, before the Captain of Reims and the eschevins, to act honestly and without favour, and not to receive more than one penny commission. In the case of his receiving more, both he and the seller of the wine were to forfeit two-pence-halfpenny to the town. [Illustration: CHURCH OF ST. REMI, REIMS.] The sales of wine mainly took place at the Etape aux Vins, where most of the wine-merchants were established, the busiest time being during the three great annual fairs, when no duties were levied. The old Etape aux Vins is now the Rue de l'Etape, jocularly styled the Rue de Rivoli of Reims, on account of the arcades formed by the projecting upper floors of its fifteenth-and sixteenth-century houses, which rest upon wooden and stone pillars. To-day the casino and the principal restaurants of the city are installed here; still the locality retains much the same aspect as it presented in the days when Remi Cauchois and Huet Hurtaut stood here and chaffered with the peasants who had brought their casks of wine on creaking wains into the city; when S. de Laval glided in search of a customer among the long-gowned fur-capped merchants of the Low Countries; when bargains were closed by a God's-penny and wetted with a stoup of Petit Jehannin's best; and when files of wine-laden wagons rolled forth from the northern gates of the city to gladden the thirsty souls of Hainault and Flanders. Some of the wine had, however, a nobler destination. An order of payment addressed by the town council to the receiver, and dated March 23, 1419, commands him to pay Jacques le Vigneron the sum of 78 livres 12 sols for six queues of 'vin blanc et clairet,' presented to the fierce Duke of Burgundy, Jean sans Peur, at the high price of about 11_s._ each.[47] Nor did his son Philip, the self-styled 'Prince of the best wines in Christendom,' disdain to draw bridle in order to receive eleven poinçons of 'vin claret' when hastening, 'Bloody with spurring, fiery red with speed,' through Reims to avenge his father's murder at the Bridge of Montereau.[48] The devastating results of the terrible struggle for supremacy waged between the Armagnacs and Burgundians, and of the invasion of Henry V. of England, are evidenced in the facts that when, in fear and trembling, the Reims council resolved to allow Duke Philip to enter the town in 1425, at the head of four thousand horse, they could only offer him one queue of Beaune, one queue of red, and one queue of white wine; and to the duchess the following year one queue of Beaune and one of French wine; and that wine sent to l'Isle Adam, at the siege of Nesle, cost as much as 19 livres, or nearly 16_s._, the queue. [Illustration: RUE DE L'ETAPE, REIMS.] [Illustration] Reims had passed under the sway of England by the Treaty of Troyes in 1420, the Earl of Salisbury becoming governor of the Champagne. The scarcity of wine, and the liking of the new possessors for their national beverage, is shown by a prohibition issued by the town council in 1427 against using wheat for making beer; and a statement of Gobin Persin, that he had sold more treacle--a famous medicinal remedy in the Middle Ages--during the past half year than in the four years previous, owing to people complaining that they were swollen up from drinking malt liquor. The English, however, at their abrupt departure from the city on the arrival of Charles and the Maid of Orleans, proved their partiality for the wine of Reims by carrying off as many wagonloads of it as they could manage to lay their hands on. [Illustration: JEANNE DARC'S FIRST INTERVIEW WITH CHARLES VII. (From a tapestry of the fifteenth century).] The gallant knights and patriot nobles who followed the Maid of Orleans to Reims, and witnessed the coronation of Charles VII. in 1429, despised, of course, the drink of their island foes, and moistened throats grown hoarse with shouting 'Vive le roi' with the choice vintage of the neighbouring slopes, freely drawn forth from the most secret recesses of the cellars of the town in honour of the glorious day. And no doubt Dame Alice, widow of Raulin Marieu, and hostess of the Asne royé (the Striped Ass), put a pot of the very best before the father of 'Jehane la Pucelle,' and did not forget, either, to score it down in the little bill of twenty-four livres which she was paid out of the _deniers communs_ for the old fellow's entertainment.[49] For the next ten years, however, the note of war resounded through the country, the hill-sides bristled with lances in lieu of vine-stakes, and instead of money spent for wine for presentation to guests of a pacific disposition, the archives of the town display a long list of sums expended in the purchase of arms, artillery, and ammunition, for the especial accommodation of less pleasant visitors, in repairing fortifications, and in payments to men charged with watching day and night for the coming of the foe. The excesses of the licentious followers of Potton de Xaintrailles and Lahire were worse than those of the English and Burgundians, spite of the four hundred and five livres which had been paid to men-at-arms and archers from the neighbouring garrisons, 'engaged by the city of Reims to guard the surrounding country, in order that the wine might be vintaged and brought into the said city and the vineyards dressed,'[50] and bitter were the complaints addressed in 1433 to the king on the falling off of the wine trade which had resulted therefrom. The ravages of the terrible 'Escorcheurs' led, in 1436, to fresh complaints and to an additional duty on each queue of 'wine of Beaune, of the Marne, and of other foreign districts' sold wholesale at Reims, the receipts to be spent in warlike preparations and on the fortifications. Some of this went to Lahire as a recompense for defending the district from 'the great routs and companies' that sought to invade it, he having, presumably on the principle of setting a thief to catch a thief, been made Bailli of Vermandois. In troublous times like these it was necessary to secure the good will of men in power and authority, and hence the town records comprise numerous offerings of money, fine linen cloths, and wine given to various nobles 'out of grace and courtesy' for their good will and 'good and agreeable services, pleasures, and love.' Madame Katherine de France (the widow of Henry V.), the Chancellor of France, the Constable Richemont, Lahire (Bailli of Vermandois), the bastard Dunois, the Archbishop of Narbonne, the Count de Vendôme, and many other nobles and dignitaries, were in turn recipients of such gifts; and the visit of King Charles the Victorious, in 1440, was celebrated by their profuse distribution.[51] [Illustration: CULTIVATION OF THE VINE AND VINTAGING IN THE FIFTEENTH CENTURY (From a /MS./ of the Propriétaire des Choses).] Despite the complete expulsion of the English from France, a depression in trade still continued; and in 1451 the lieutenant of the town was sent to court to complain that, owing to the exactions of the farmers of the revenue, merchants would no longer come to Reims to buy wine. Louis XI., who was crowned at Reims on 15th August 1461, entered the city in great pomp, accompanied by Philip, Duke of Burgundy, and his son the Count of Charolais, afterwards Charles the Bold; the Duke of Bourbon, the Duke of Cleves, and his brother the Lord of Ravenstein, all three nephews of Duke Philip; the Counts of St. Pol, Angoulême, Eu, Vendôme, Nassau, and Grandpré; Messire Philip of Savoy, and many others,--'all so richly dressed that it was a noble sight to see,' remarks Enguerrand de Monstrelet. Prior to being crowned, the king handed his sword to Duke Philip, and requested the latter to bestow upon him the honour of knighthood, which the duke did, and afterwards gave the accolade to several other persons of distinction. The coronation, with its accompaniment of 'many beautiful mysteries and ceremonies,' was performed by Archbishop Jean Juvénal des Ursins, assisted by the Cardinal of Constance, the Patriarch of Antioch, a papal legate, four archbishops, seventeen bishops, and six abbots. At its close the twelve peers of France[52] dined at the king's table; and after the table was cleared the Duke of Burgundy knelt and did homage for Burgundy, Flanders, and Artois, other lords following his example. [Illustration: THE PEERS OF FRANCE PRESENT AT THE CORONATION OF LOUIS XI. AT REIMS (From painted-glass windows in Evreux Cathedral).] Louis XI., on his accession, found himself in presence of an exhausted treasury, and cast about for an expedient to fill it. The wine he drunk at his coronation at Reims may have suggested the dues which, only a month afterwards, he decreed should be levied on this commodity, in conjunction with an impost on salt. The inhabitants of the archiepiscopal city found it impossible to believe in such a return for their wonted hospitality, and the vine-growers assailed the collectors furiously. The affair resulted in a general outbreak, known as the Mique-Maque, and in the final hanging, branding, mutilating, and banishing of a number of individuals, half of whom, it may fairly be presumed, were innocent. The wars between France and Burgundy were also severely felt by the Rémois, whose territory was ravaged by the followers of Charles the Bold after Montlhery, and who suffered almost as much at the hands of their friends as at those of their foes. The garrison put into the town shared amongst themselves the country for a circuit of eight leagues, the meanest archer having a couple of villages, whence he exacted, at pleasure, corn, wood, provisions, and wine, the latter in such profusion that the surplus was sold in the streets, the smallest allowance for each lance being a queue, valued at ten livres, monthly. In 1470 and the following years large subsidies of wine were, moreover, despatched from time to time to the king's army in the field; a cartload being judiciously sent to General Gaillard, 'as he is well disposed towards us, and it is necessary to cultivate such people.' Complaints made in 1489 set forth that in consequence of the _octroi_ of the river Aisne, which had been established six years previously, the merchants of Liège, Mezières, and Rethel, instead of coming to Reims to buy wine, were obtaining their supplies from Orleans. The landing of Henry VII. of England, in 1495, spread new alarms throughout the Champagne, and orders were given for all the vine-stakes within a radius of two leagues of Reims to be pulled up, so that the enemy might be prevented from cooking provisions or filling up the moats of the fortifications with them. Pillaging foes and extortionate defenders were bad enough, but the vine-growers had yet other enemies, to wit, certain noxious little insects, which were in the habit of feeding on the young buds, though there is no record that they were ever so troublesome at Reims as they were in other parts of the Champagne, notably at Troyes, where on the Friday after Pentecost 1516 they were formally and solemnly enjoined by Maître Jean Milon to depart within six days from the vineyards of Villenauxe, under pain of anathema and malediction.[53] A century and a half later these insects renewed their ravages, and were exorcised anew by the rural dean of Sézanne, on the order of the Bishop of Troyes. [Illustration: CULTURE OF THE VINE--SIXTEENTH CENTURY (From a /MS./ Calendar).] [Illustration: TREADING GRAPES--SIXTEENTH CENTURY (From a /MS./ Calendar).] [Illustration: BUTLER OF THE SIXTEENTH CENTURY (Facsimile of a woodcut in the Cosmographie Universelle, 1549).] [Illustration: CORONATION OF LOUIS XII. AT REIMS (From a painting on wood of the fifteenth century).] The close of the fifteenth century witnessed another coronation, that of the so-styled 'Father of his People,' Louis XII., celebrated with all due splendour in May 1498. The six ecclesiastical peers--principal among whom was the Cardinal Archbishop of Reims, Guillaume Briconnet, in rochet and stole, mitre and crozier; and the six representatives of the secular peerages, Burgundy, Normandy, Aquitaine, Flanders, Toulouse, and Champagne--solemnly invested their sovereign with sword, spurs, ring, orb, sceptre, crown, and all the other outward symbols of royalty; whilst the vaulted roof rang with the acclamations of the people assembled in the nave, and the triumphant peals from the heralds' silver trumpets, on the banneroles of which was emblazoned the monarch's favourite badge, the hedgehog. Trumpet-blowing and shouting being both provocative of thirst, peers and people did ample justice to the wine freely provided for all comers on this occasion. [Illustration: DOORWAY IN THE ARCHIEPISCOPAL PALACE AT REIMS.] Francis I. was crowned at Reims in January 1515; and on the occasion of his visiting the city sixteen years afterwards, twenty poinçons of wine were offered to him and sixty to his suite, so that this bibulous monarch had a good opportunity of comparing various growths of the Mountain and the River with the wine from his own vineyards at Ay; and possibly the Emperor Charles V. did his best to institute similar comparisons on his self-invited incursion into the district in 1544. For not only did these two great rivals, but also our own Bluff King Harry and the magnificent Leo X., have each their special commissioner stationed at Ay to secure for them the finest vintages of that favoured spot, the renown of which thenceforward has never paled. The wine despatched for their consumption was most likely sent direct from the vineyards in carefully-sealed casks; but the bulk of the river growths came to Reims for sale, and helped to swell the importance of the town as an emporium of the wine-trade. When Mary Queen of Scots came to Reims, a mere child, in 1550, four poinçons of good wine, with a dozen peacocks and as many turkeys, were presented to her. There are no records, however, of any further offerings to her when, as the widowed queen of Francis II., she visited Reims at Eastertide in 1561, and again during the summer of the same year, shortly before her final departure from France. On these occasions she was the guest, by turns, of her aunt Renée de Lorraine, at the convent of St. Pierre les Dames,--to-day a woollen factory,--and of her uncle, the 'opulent and libertine' Charles de Lorraine, Cardinal and Archbishop of Reims, at the handsome archiepiscopal palace, where this powerful prelate resided in unwonted state. As the rhyme goes-- 'Bishop and abbot and prior were there, Many a monk and many a friar, Many a knight and many a squire, With a great many more of lesser degree Who served the Lord Primate on bended knee. Never, I ween, Was a prouder seen, Read of in books, or dreamt of in dreams, Than the Cardinal Lord Archbishop of Reims.' Brusquet, the court fool of Henry II., Francis II., and Charles IX., was a great favourite with this princely prelate, and accompanied him several times on his embassies to foreign states. Brusquet's wit was much appreciated by the cardinal, and has been highly extolled by Brantome; but most of the specimens handed down to us will not bear repetition, much less translation, from their coarseness. When the cardinal was at Brussels in 1559, negotiating the peace of Cateau Cambresis with Philip II., Brusquet one day at dessert jumped on to the table, and rolled along the whole length, wrapping himself up like a mummy in the cloth, with all the knives, forks, and spoons, as he went, and rolling over at the further end. The emperor, Charles V., who was the host, was so delighted that he told him to keep the plate himself. Brusquet had great dread of being drowned, and objected one day to go in a boat with the cardinal. 'Do you think any harm can happen to you with me, the pope's best friend?' said the latter. 'I know that the pope has power over earth, heaven, and purgatory,' said Brusquet; 'but I never heard that his dominion extended over water.' It is not unlikely that the effigy forming one of the corbels beneath the chapter court gateway, and representing a fool in the puffed and slashed shoes and bombasted hose of the Renaissance, with his bauble in his hand, may be intended for Brusquet; for in the Middle Ages the ecclesiastical councils had forbidden dignitaries of the Church to have fools of their own.[54] [Illustration: CHIMNEYPIECE IN THE BANQUETING HALL OF THE ARCHIEPISCOPAL PALACE AT REIMS.] It was in the grand hall of the archiepiscopal palace of Reims--an apartment which is very little changed from the days when Charles Cardinal de Lorraine entertained Henry II., Francis II., and Charles IX. in succession--that the coronation banquets at this epoch used to take place. Of the richness and beauty of the internal decorations of this interesting edifice some idea may be gained from the accompanying illustrations. [Illustration: CORBELS, FROM THE CHAPTER COURT GATEWAY, REIMS.] The stock of wine at Reims at the period of Mary's first visit must have been very low, owing to the continued requisitions of it for armies in the field, for 'German reiters at Attigny,' and 'Italian lansquenets at Voulzy;' and no doubt its production subsequently decreased to some extent from the orders issued to the surrounding villagers to destroy all their ladders and vats lest they should fall into the hands of the enemy, at the epoch of the threatened approach of the German Emperor in 1552. At the coronation of Francis II. in 1559, and at that of Charles IX. (the future instigator of the massacre of St. Bartholomew) two years later, the citizens of Reims presented the newly-crowned monarchs with the customary gifts of Burgundy and Champagne wines.[55] In the latter instance, however, the gift met with an unexpected return, inasmuch as the king, after the fashion of Domitian, issued an edict in 1566, ordering that vines should only occupy one-third of the area of a canton, and that the remaining two-thirds should be arable and pasture land. When the forehead of Henry III., the last of the treacherous race of Valois, was touched with the holy oil by the Cardinal de Guise, the wine of Reims for the first time was alone used to furnish forth the attendant banquet, and the appreciative king modified his brother's edict to a simple recommendation to the governors of provinces to see that the planting of vines did not lead to a neglect of other labours. During this reign the wine of Ay reached the acme of renown, and came to be described as 'the ordinary drink of kings and princes.'[56] [Illustration: VIGNERON OF THE SIXTEENTH CENTURY (Facsimile of a woodcut of the period).] In the troubles which followed the death of Henry III., when the east of France was laid desolate in turn by Huguenots and Leaguers, Germans and Spaniards; when Reims became a chief stronghold of the Catholics, who formed a kind of Republic there, and the remaining towns and villages of the district changed masters almost daily, the foragers of the party of Henry of Navarre and that of the League caused great tribulation amongst the vine-dressers and husbandmen of the Montagne and of the Marne. In 1589 very little wine could be vintaged around Reims 'through the affluence of enemies,' dolefully remarks a local analist.[57] After the battle of Ivry, Reims submitted to the king, but many of the surrounding districts, Epernay among the number, still sided with his opponents. Epernay fell, however, in 1592, after a cruel siege; and in the autumn of the same year the leaders of the respective parties met at the church of St. Tresain, at Avenay, and agreed to a truce during the ensuing harvest, in order that the crops of corn and wine might be gathered in--a truce known as the Trève des Moissons. The yield turned out to be of very good quality, the new wine fetching from 40 to 70 livres the queue.[58] The system of cultivation prevailing in the French vineyards at this epoch must have been peculiar, since the staple agricultural authority of the day states that, to have an abundant crop and good wine, all that was necessary was for the vine-dresser to wear a garland of ivy, and for crushed acorns and ground vetches to be put in the hole at the time of planting the vine-shoots; that, moreover, grapes without stones could be obtained by taking out the pith of the young plant, and wrapping the end in wet paper, or sticking it in an onion when planting; that to get grapes in spring a vine-shoot should be grafted on a cherry-tree; and that wine could be made purgative by watering the roots of the vine with a laxative, or inserting some in a cleft branch.[59] [Illustration: Church of St. Jacques. The Cathedral. Mont de la Pompelle. Church of St. Remi. Tower of St. Victor. Porte de Vesle. Porte de Dieu Lumière. Porte de Flèchambault. THE CITY OF REIMS IN 1635 (From an engraving of the period).] In the seventeenth century the still wine of the province of Champagne was destined, like the setting sun, to gleam with well-nigh unparalleled radiance up to the moment of its almost total eclipse. Continual care and untiring industry had resulted in the production of a wine which seems to have been renowned beyond all others for a delicate yet well-developed flavour peculiarly its own, but of which the wonderful revolution effected by the invention of sparkling wine has left but few traces. In 1604 the yield was so abundant that the vintagers were at their wits' end for vessels to contain their wine; but three years later so poor a vintage took place as had not been known within the memory of man. During the winter the cold was so intense that wine froze not only in the cellars, but at table close to the fire, and by the ensuing spring it had grown so scarce that the veriest rubbish fetched 80 livres the queue at Reims.[60] In 1610, at the banquet following the coronation of Louis XIII., the only wine served was that of Reims, at 175 livres, or about 7_l._, the queue; and the future _raffinés_ of the Place Royale who assisted at that ceremony were by no means the men to forget or neglect an approved vintage after once tasting it. Champagne, it has been said, was crowned at the same time with the king, and of the two made a better monarch. Five years later a complaint, addressed to the king on the subject of the _fermiers des aides_ trying to levy duties on goods sold at the fairs, asserted it was notorious that the chief commerce of Reims consisted of wines. According to the police ordinances of 1627, the price of these was fixed three times a year, namely, at Martinmas, Mid-Lent, and Midsummer; and tavern-keepers were bound to have a tablet inscribed with the regulation price fixed outside their houses, and were not allowed to sell at a higher rate, under a penalty of 12 livres for the first, and 24 livres for the second offence. Moreover, to encourage the production of the locality, they were strictly forbidden to sell in their taverns any other wine than that of the 'cru du pays et de huit lieues es environs,' under pain of confiscation and a fine, the amount of which was arbitrary. The vine-dressers too, in the same ordinances, were enjoined to kill and burn all vine-slugs and other vermin, which during 1621 and the two succeeding years had caused much damage.[61] [Illustration] [Illustration] This rule must have been perforce relaxed during the troubles of the Fronde, when for two years the troops of the Marshal du Plessis Praslin lived as in a conquered country, indulging in drinking carousals in the wine-shops of the towns, or marching in detachments from village to village throughout the district, in order to prevent all those who neglected to pay the contributions imposed from working in their vineyards; when their leader, on the refusal of the Rémois to supply him with money, ravaged the vineyards of the plains of les Moineaux and Sacy; and when Erlach's foreigners at Verzy sacked the whole of the Montagne from March until July 1650. As a consequence, people in the following year were existing on herbs, roots, snails, blood, bread made of bran, cats, dogs, &c., or dying by hundreds through eating bread made of unripe wheat harvested in June; the ruin of the citizens being completed, according to an eyewitness, at the epoch of dressing the vines, owing to the lack of men to do the work.[62] A contemporary writer, however, asserts that the vineyards still continued 'to cover the mountains and to encircle the town of Reims like a crown of verdure;' and that their produce not only supplied all local wants, but, transported beyond the frontier, caused the gold of the Indies to flow in return into the town, and spread its reputation afar.[63] [Illustration: A BETROTHAL BANQUET IN THE SEVENTEENTH CENTURY.] Such was the repute of the Champagne wines when Louis XIV. was crowned at Reims in 1654, that all the great lords present on the occasion were exceedingly anxious to partake of them, and no doubt regarded with envious eyes the huge basket containing a hundred bottles of the best which the deputies from Epernay had brought with them as a present to the gallant Turenne. He at least was no stranger to the merits of the wine, for the records of Epernay show that many a caque had found its way to his tent during the two preceding years, when he was defending the Champagne against Condé and his Spanish allies. In the same year (1654), the Procureur de l'Echevinage speaks of the chief trade of Reims as consisting in the sale of wine, of which the inhabitants collect large quantities, both from the Montagne de Reims and the Rivière de Marne, through the merchants who make this their special trade--a trade sorely interrupted by the incursions of Montal and his Spaniards in 1657 and 1658. Guy Patin too, writing in 1666, mentions the fact of Louis XIV. making a present to Charles II. of England of two hundred pièces of excellent wine--Champagne, Burgundy, and Hermitage; and three years later is fain himself to exclaim, 'Vive le pain de Gonesse, vive le bon vin de Paris, de Bourgogne, de Champagne!' whilst Tavernier the traveller did his best to spread the fame of the Champagne wine by presenting specimens to all the sovereigns whom he had the honour of saluting during his journeyings abroad.[64] It was about the eighth decade of this century, when the renown of the Grand Monarque was yet at its apogee, and when for many years the soil of the province had not been profaned by the foot of an invader, that the still wine of the Champagne attained its final point of perfection. The Roi Soleil himself, we are assured by St. Simon, never drank any other wine in his life till about 1692, when his physician, the austere Fagon, condemned his debilitated stomach to well-watered Burgundy, so old that it was almost tasteless, and the king consoled himself with laughing at the wry faces pulled by foreign nobles who sought and obtained the honour of tasting his especial tipple.[65] An anonymous Mémoire[66] written early in the ensuing century (1718) states that, although their red wine had long before been made with greater care and cleanliness than any other wine in the kingdom, the Champenois had only studied to produce a _gray_, and indeed almost white, wine, within the preceding fifty years. This would place about 1670 the first introduction of the new colourless wine, obtained by gathering grapes of the black variety with the utmost care at early dawn, and ceasing the vintage at nine or ten in the morning, unless the day were cloudy. Despite these precautions a rosy tinge--compared to that lent by a dying sunset to the waters of a clear stream--was often communicated to the wine, and led to the term 'partridge's eye' being applied to it. St. Evremond, the epicurean Frenchman--who emigrated to the gay court of Charles II. at Whitehall to escape the gloomy cell designed for him in the Bastille--and the mentor of the Count de Grammont, writing from London about 1674, to his brother 'profès dans l'ordre des coteaux,'[67] the Count d'Olonne, then undergoing on his part a species of exile at Orleans for having suffered his tongue to wag a little too freely at court, says: 'Do not spare any expense to get Champagne wines, even if you are at two hundred leagues from Paris. Those of Burgundy have lost their credit amongst men of taste, and barely retain a remnant of their former reputation amongst dealers. There is no province which furnishes excellent wines for all seasons but Champagne. It supplies us with the wines of Ay, Avenay, and Hautvillers, up to the spring; Taissy, Sillery, Verzenai, for the rest of the year.'[68] 'The wines of the Champagne,' elsewhere remarks this renowned _gourmet_, 'are the best. Do not keep those of Ay too long; do not begin those of Reims too soon. Cold weather preserves the spirit of the River wines, hot removes the _goût de terroir_ from those of the Mountain.' Writing also in 1701, he alludes to the care with which the Sillery wines were made forty years before. Such a distinction of seasons would imply that wine, instead of being kept, was drunk within a few months of its manufacture; though this, except in the case of wine made as 'tocane,' which could not be kept, would appear to be a matter rather of taste than necessity. This custom of drinking it before fermentation was achieved, and also the natural tendency of the wine of this particular region to effervesce--a tendency since taken such signal advantage of by the manufacturers of sparkling Champagne--are treated of in a work of the period,[69] the author of which, after noting the excellence of certain growths of Burgundy, goes on to say that, 'If the vintage in the Champagne is a successful one, it is thither that the shrewd and dainty hasten. There is not,' continues he, 'in the world a drink more noble and more delicious; and it is now become so highly fashionable that, with the exception of those growths drawn from that fertile and agreeable district which we call in general parlance that of Reims, and particularly from St. Thierry, Verzenay, Ay, and different spots of the Mountain, all others are looked upon by the dainty as little better than poor stuff and trash, which they will not even hear spoken of.' He extols the admirable _sève_ of the Reims wine, its delicious flavour, and its perfume, which with ludicrous hyperbole he pronounces capable of bringing the dead to life. Burgundy and Champagne, he says, are both good, but the first rank belongs to the latter, 'when it has not that tartness which some debauchees esteem so highly, when it clears itself promptly, and only works as much as the natural strength of the wine allows; for it does not do to trust so much to that kind of wine which is always in a fury, and boils without intermission in its vessel.' Such wine, he maintains, is quite done for by the time Easter is over, and only retains of its former fire a crude tartness very unpleasant and very indigestible, which is apt to affect the chest of those who drink it. He recommends that Champagne should be drunk at least six months after the end of the year, and that the grayest wines should always be chosen as going down more smoothly and clogging the stomach less, since, however good the red wine may be as regards body, from its longer _cuvaison_, it is never so delicate, nor does it digest so promptly, as the others. He concludes, therefore, that it is better to drink old wine, or at any rate what then passed as old wine, as long as one can, in order not to have to turn too soon to the new ones, 'which are veritable head-splitters, and from their potency capable of deranging the strongest constitutions.' Above all, he urges abstinence from such 'artificial mummeries' as the use of ice, 'the most pernicious of all inventions' and the enemy of wine, though at that time, he admits, very fashionable, especially amongst certain 'obstreperous voluptuaries,' 'who maintain that the wine of Reims is never more delicious than when it is drunk with ice, and that this admirable beverage derives especial charms from this fatal novelty.' Ice, he holds, not only dispels the spirit and diminishes the flavour, _sève_, and colour of the wine, but is most pernicious and deadly to the drinker, causing 'colics, shiverings, horrible convulsions, and sudden weakness, so that frequently death has crowned the most magnificent debauches, and turned a place of joy and mirth into a sepulchre.' Wherefore let all drinkers of Champagne _frappé_ beware. Here we have ample proof of the popularity of the wines of the Champagne, a popularity erroneously said to be due in some measure to the fact that both the Chancellor le Tellier, father of Louvois, and Colbert, the energetic comptroller-general of the state finances, and son of a wool-merchant of Reims, possessed large vineyards in the province.[70] Lafontaine, who was born in the neighbourhood, declared his preference for Reims above all cities, on account of the Sainte Ampoule, its good wine, and the abundance of other charming objects;[71] and Boileau, writing in 1674, depicts an ignorant churchman, whose library consisted of a score of well-filled hogsheads, as being fully aware of the particular vineyard at Reims over which the community he belonged to held a mortgage.[72] James II. of England was particularly partial to the wine of the Champagne. When the quinquennial assembly of the clergy was held in 1700, at the Château of St. Germain-en-Laye, where he was residing, Charles Maurice le Tellier, brother to Louvois and Archbishop of Reims, who presided, 'kept a grand table, and had some Champagne wine that was highly praised. The King of England, who rarely drank any other, heard of it, and sent to ask some of the archbishop, who sent him six bottles. Some time afterwards the king, who found the wine very good, sent to beg him to send some more. The archbishop, more avaricious of his wine than of his money, answered curtly that his wine was not mad, and therefore did not run about the streets, and did not send him any.'[73] Du Chesne, who, when Fagon became medical attendant to Louis XIV., succeeded him as physician to the 'fils de France,' and who died at Versailles in 1707, aged ninety-one, in perfect health, ascribed his longevity to his habit of eating a salad every night at supper, and drinking only Champagne, a _régime_ which he recommended to all.[74] The wine was nevertheless the indirect cause of the death of the poet Santeuil, who, although a canon of St. Victor, was very much fonder of Champagne and of sundry other good things than he ought to have been. A wit and a _bon vivant_, he was a great favourite of the Duc de Bourbon, son of the Prince de Condé, whom he accompanied in the summer of 1697 to Dijon. 'One evening at supper the duke amused himself with plying Santeuil with Champagne, and going on from joke to joke, he thought it funny to empty his snuff-box into a goblet of wine, and make Santeuil drink it, in order to see what would happen. He was pretty soon enlightened. Vomiting and fever ensued, and within forty-eight hours the unhappy wretch died in the torments of the damned, but filled with the sentiments of great penitence, with which he received the sacraments and edified the company, who, though little given to be edified, disapproved of _such a cruel experiment_.'[75] Of course nothing was done, or even said, to the duke. 'Sire,' said the president of a deputation bringing specimens of the various productions of Reims to the Grand Monarque when he visited the city in 1666, 'we offer you our wine, our pears, our gingerbread, our biscuits, and our hearts;' and Louis, who was a noted lover of the good things of this life, answered, turning to his suite, 'There, gentlemen, that is just the kind of speech I like.' To this day Reims manufactures by the myriad the crisp finger-shaped sponge-cakes called 'biscuits de Reims,' which the French delight to dip in their wine; juvenile France still eagerly devours its _pain d'épice_, and the city sends forth far and wide the baked pears which have obtained so enviable a reputation. But the production of such wine as that offered to the king has long since almost ceased, while its fame has been eclipsed tenfold by wine of a far more delicious kind, the origin and rise of which has now to be recounted. This is the sparkling wine of Champagne, which has been fitly compared to one of those younger sons of good family, who, after a brilliant and rapid career, achieve a position far eclipsing that of their elder brethren, whose fame becomes merged in theirs.[76] [Illustration] III. /Invention and Development of Sparkling Champagne./ The ancients acquainted with sparkling wines--Tendency of Champagne wines to effervesce noted at an early period--Obscurity enveloping the discovery of what we now know as sparkling Champagne--The Royal Abbey of Hautvillers--Legend of its foundation by St. Nivard and St. Berchier--Its territorial possessions and vineyards--The monks the great viticulturists of the Middle Ages--Dom Perignon--He marries wines differing in character--His discovery of sparkling white wine--He is the first to use corks to bottles--His secret for clearing the wine revealed only to his successors Frère Philippe and Dom Grossart--Result of Dom Perignon's discoveries--The wine of Hautvillers sold at 1000 livres the queue--Dom Perignon's memorial in the Abbey-Church--Wine flavoured with peaches--The effervescence ascribed to drugs, to the period of the moon, and to the action of the sap in the vine--The fame of sparkling wine rapidly spreads--The Vin de Perignon makes its appearance at the Court of the Grand Monarque--Is welcomed by the young courtiers--It figures at the suppers of Anet and Chantilly, and at the orgies of the Temple and the Palais Royal--The rapturous strophes of Chaulieu and Rousseau--Frederick William I. and the Berlin Academicians--Augustus the Strong and the page who pilfered his Champagne--Horror of the old-fashioned _gourmets_ at the innovation--Bertin du Rocheret and the Marshal d'Artagnan--System of wine-making in the Champagne early in the eighteenth century--Bottling of the wine in flasks--Icing Champagne with the corks loosened. A sybarite of our day has remarked that the life of the ancient Greeks would have approached the perfection of earthly existence had they only been acquainted with sparkling Champagne. As, however, amongst the nations of antiquity the newly-made wine was sometimes allowed to continue its fermentation in close vessels, it may be conceived that when freshly drawn it occasionally possessed a certain degree of briskness from the retained carbonic acid gas.[77] Virgil's expression, 'Ille impiger hausit Spumantem pateram,'[78] demonstrates that the Romans--whose _patera_, by the way, closely resembled the modern champagne-glass--were familiar with frothy and sparkling wines, although they do not seem to have intentionally sought the means of preserving them in this condition.[79] [Illustration] [Illustration] The early vintagers of the Champagne can hardly have helped noting the natural tendency of their wine to effervesce, the difficulty of entirely overcoming which is exemplified in the precautions invariably taken for the production of Sillery sec; indeed tradition claims for certain growths of the Marne, from a period of remote antiquity, a disposition to froth and sparkle.[80] Local writers profess to recognise in the property ascribed by Henry of Andelys to the wine of Chalons, of causing both the stomach and the heels to swell,[81] a reference to this peculiarity.[82] The learned Baccius, physician to Pope Sixtus V., writing at the close of the sixteenth century of the wines of France, mentions those 'which bubble out of the glass, and which flatter the smell as much as the taste,'[83] though he does not refer to any wine of the Champagne by name. An anonymous author, some eighty years later,[84] condemns the growing partiality for the 'great _vert_ which certain debauchees esteem so highly' in Champagne wines, and denounces 'that kind of wine which is always in a fury, and which boils without ceasing in its vessel.' Still he seems to refer to wine in casks, which lost these tumultuous properties after Easter. Necessity being the mother of invention, the inhabitants of the province had in the sixteenth century already devised and put in practice a method of allaying fermentation, and obtaining a settled wine within four-and-twenty hours, by filling a vessel with 'small chips of the wood called in French _sayette_,' and pouring the wine over them.[85] With all this, a conscientious writer candidly acknowledges that, despite minute and painstaking researches, he cannot tell when what is now known as sparkling Champagne first made its appearance. The most ancient references to it of a positive character that he could discover are contained in the poems of Grenan and Coffin, printed in 1711 and 1712; yet its invention certainly dates prior to that epoch,[86] and earlier poets have also praised it. It seems most probable that the tendency to effervescence already noted became even more marked in the strong-bodied gray and 'partridge-eye' wines, first made from red grapes about 1670, than in the yellowish wine previously produced, like that of Ay, from white grapes,[87] and recommended, from its deficiency in body, to be drunk off within the year.[88] These new wines, when in a quasi-effervescent state prior to the month of March, offered a novel attraction to palates dulled by the potent vintages of Burgundy and Southern France;[89] and their reputation quickly spread, though some old _gourmets_ might have complained, with St. Evremond, of the taste introduced by _faux delicats_.[90] They must have been merely _cremant_ wines--for glass-bottle making was in its infancy, and corks as yet unknown[91]--and doubtless resembled the present wines of Condrieu, which sparkle in the glass on being poured out, during their first and second years, but with age acquire the characteristics of a full-bodied still wine. The difficulty of regulating their effervescence in those pre-scientific days must have led to frequent and serious disappointments. The hour, however, came, and with it the man. [Illustration: GATEWAY OF THE ABBEY OF HAUTVILLERS.] [Illustration: THE CHURCH OF HAUTVILLERS, WITH THE REMAINS OF THE ABBEY.] In the year 1670, among the sunny vineyard slopes rising from the poplar-fringed Marne, there stood in all its pride the famous royal Abbey of St. Peter at Hautvillers. Its foundation, of remote antiquity, was hallowed by saintly legend. Tradition said that about the middle of the seventh century St. Nivard, Bishop of Reims, and his godson, St. Berchier, were seeking a suitable spot for the erection of a monastery on the banks of the river. The way was long, the day was warm, and the saints but mortal. Weary and faint, they sat down to rest at a spot identified by tradition with a vineyard at Dizy, to-day belonging to Messrs. Bollinger, but at that time forming part of the forest of the Marne. St. Nivard fell asleep, with his head in St. Berchier's lap, when the one in a dream, and the other with waking eyes, saw a snow-white dove--the same, firm believers in miracles suggested, which had brought down the holy oil for the anointment of Clovis at his coronation at Reims--flutter through the wood, and finally alight afar off on the stump of a tree. Such an omen could no more be neglected by a seventh-century saint than a slate full of scribble by a nineteenth-century spiritualist, and accordingly the site thus miraculously indicated was forthwith decided upon. Plans for the edifice were duly drawn out and approved of, and the abbey rose in stately majesty, the high altar at which St. Berchier was solemnly invested with the symbols of abbatial dignity being erected upon the precise spot occupied by the tree on which the snow-white dove had alighted.[92] As time rolled on and pious donations poured in, the abbey waxed in importance, although it was sacked by the Normans when they ravaged the Champagne, and was twice destroyed by fire--once in 1098, and again in 1440--when each time it rose ph[oe]nix-like from its ashes. [Illustration] [Illustration] In 1670 the abbey was, as we have said, in all its glory. True, it had been somewhat damaged a century previously by the Huguenots, who had fired the church, driven out the monks, sacked the wine-cellars, burnt the archives, and committed sundry other depredations inherent to civil and religious warfare; but the liberal contributions of the faithful, including Queen Marie de Medicis, had helped to efface all traces of their visit. The abbey boasted many precious relics rescued from the Reformers' fury, the most important being the body of St. Helena, the mother of Constantine the Great, which had been in its possession since 844, and attracted numerous pilgrims. The hierarchical status of the abbey was high; for no less than nine archbishops had passed forth through its stately portal to the see of Reims, and twenty-two abbots, including the venerable Peter of Cluny, to various distinguished monasteries. Its territorial possessions were extensive; for its abbot was lord of Hautvillers, Cumières, Cormoyeux, Bomery, and Dizy la Rivière, and had all manner of rights of _fourmage_, and _huchage_, _vinage_, and _pressoir banal_, and the like,[93] to the benefit of the monks and the misfortune of their numerous dependents. Its revenues were ample, and no small portion was derived from the tithes of fair and fertile vinelands extending for miles around, and from the vineyards which the monks themselves cultivated in the immediate neighbourhood of the abbey. [Illustration] It should be remembered that for a lengthy period--not only in France, but in other countries--the choicest wines were those produced in vineyards belonging to the Church, and that the _vinum theologium_ was justly held superior to all others. The rich chapters and monasteries were more studious of the quality than of the quantity of their vintages; their land was tilled with particular care, and the learning, of which in the Middle Ages they were almost the sole depositaries, combined with opportunities of observation enjoyed by the members of these fraternities by reason of their retired pursuits, made them acquainted at a very early period with the best methods of controlling the fermentation of the grape and ameliorating its produce.[94] To the monks of Bèze we owe Chambertin, the favourite wine of the first Napoleon; to the Cistercians of Citaulx the perfection of that Clos Vougeot which passing regiments saluted _tambour battant_; and the Benedictines of Hautvillers were equally regardful of the renown of their wines and vineyards. In 1636 they cultivated one hundred arpents themselves,[95] their possessions including the vineyards now known as Les Quartiers and Les Prières at Hautvillers, and Les Barillets, Sainte Hélène, and Cotes-à-bras at Cumières, the last named of which still retains a high reputation. [Illustration] Over these vineyards there presided in 1670 a worthy Benedictine named Dom Perignon, who was destined to gain for the abbey a more world-wide fame than the devoutest of its monks or the proudest of its abbots. His position was an onerous one, for the reputation of the wine was considerable, and it was necessary to maintain it. Henry of Andelys had sung its praises as early as the thirteenth century; and St. Evremond, though absent from France for nearly half a score years, wrote of it in terms proving that he had preserved a lively recollection of its merits. Dom Perignon was born at Sainte Ménehould in 1638, and had been elected to the post of procureur of the abbey about 1668, on account of the purity of his taste and the soundness of his head. He proved himself fully equal to the momentous task, devotion to which does not seem to have shortened his days, since he died at the ripe old age of seventy-seven. It was Dom Perignon's duty to superintend the abbey vineyards, supervise the making of the wine, and see after the tithes, paid either in wine or grapes[96] by the neighbouring cultivators to their seignorial lord the abbot. The wine which thus came into his charge was naturally of various qualities; and having noted that one kind of soil imparted fragrance and another generosity, while the produce of others was deficient in both of these attributes, Dom Perignon, in the spirit of a true Benedictine, hit upon the happy idea of 'marrying,' or blending, the produce of different vineyards together,[97] a practice which is to-day very generally followed by the manufacturers of Champagne. Such was the perfection of Dom Perignon's skill and the delicacy of his palate, that in his later years, when blind from age, he used to have the grapes of the different districts brought to him, and, recognising each kind by its flavour, would say, 'You must marry the wine of this vineyard with that of such another.'[98] [Illustration] But the crowning glory of the Benedictine's long and useful life remains to be told. He succeeded in obtaining for the first time in the Champagne a perfectly white wine from black grapes, that hitherto made having been gray, or of a pale-straw colour.[99] Moreover, by some happy accident, or by a series of experimental researches--for the exact facts of the discovery are lost for ever--he hit upon a method of regulating the tendency of the wines of this region to effervesce, and by paying regard to the epoch of bottling, finally succeeded in producing a perfectly sparkling wine, that burst forth from the bottle and overflowed the glass, and was twice as dainty to the palate, and twice as exhilarating in its effects, as the ordinary wine of the Champagne. A correlative result of his investigations was the present system of corking bottles, a wisp of tow dipped in oil being the sole stopper in use prior to his time.[100] To him, too, we owe not only sparkling Champagne itself, but the proper kind of glass to drink it out of. The tall, thin, tapering _flute_ was adopted, if not invented, by him, in order, as he said, that he might watch the dance of the sparkling atoms.[101] The exact date of Dom Perignon's discovery of sparkling wine seems to be wrapped in much the same obscurity as are the various attendant circumstances. It was certainly prior to the close of the seventeenth century; as the author of an anonymous treatise, printed at Reims in 1718, remarked that for more than twenty years past the taste of the French had inclined towards sparkling wines, which they had 'frantically adored,' though during the last three years they had grown a little out of conceit with them.[102] This would place it at 1697, at the latest. [Illustration] To Dom Perignon the abbey's well-stocked cellar was a far cheerfuller place than the cell. Nothing delighted him more than 'To come down among this brotherhood Dwelling for ever underground, Silent, contemplative, round, and sound; Each one old and brown with mould, But filled to the lips with the ardour of youth, With the latent power and love of truth, And with virtues fervent and manifold.' Ever busy among his vats and presses, barrels and bottles, Perignon found out a method of clearing wine, so as to preserve it perfectly limpid and free from all deposit, without being obliged, like all who sought to rival him in its production, to _dépoter_ the bottles--that is, to decant their contents into fresh ones.[103] This secret, which helped to maintain the high reputation of the wine of Hautvillers when the manufacture of sparkling Champagne had extended throughout the district, he guarded even better than he was able to guard the apple of his eye. At his death, in 1715, he revealed it only to his successor, Frère Philippe, who, after holding sway over vat and vineyard for fifty years, died in 1765, imparting it with his latest breath to Frère André Lemaire. Revoked perforce from his functions by the French Revolution, he in turn, before his death about 1795, communicated it to Dom Grossart, who exults over the fact that whilst the greatest Champagne merchants were obliged to _dépoter_, the monks of Hautvillers had never done so.[104] Dom Grossart, who had counted the Moëts amongst his customers, died in his turn without making any sign, so that the secret of Perignon perished with him. Prior to that event, however, the present system of _dégorgeage_ was discovered, and eventually _dépotage_ was no longer practised.[105] The material result of Dom Perignon's labours was such that one of the presses of the abbey bore this inscription: 'M. de Fourville, abbot of this abbey, had me constructed in the year 1694, and that same year sold his wine at a thousand livres the queue.'[106] Their moral effect was so complete that his name became identified with the wine of the abbey. People asked for the wine of Perignon, till they forgot that he was a man and not a vineyard,[107] and within a year of his death his name figures amongst a list of the wine-producing slopes of the Champagne.[108] His reputation has outlasted the walls within which he carried on his labours, and his merits are thus recorded, in conventual Latin of the period, on a black-marble slab still to be seen within the altar-steps of the abbey-church of Hautvillers.[109] [Illustration: D . O . M . HIC JACET DOM. PETRUS PERIGNON HUJUS MÑRII PER ANNOS QUADGINTA SEPTEM CELLERARIUS QUI RE FAMILLIARI SUMMA CUM LAUDE ADMINISTRATA VIRTUTIBUS PLENUS PATERNO QUE JMPRIMIS IN PAUPERIS AMORE OBIIT ÆTATIS 77^o. ANNO 1715 REQUISCAT IN PACE AMEN] The anonymous _Mémoire_ of 1718 gives, with an amount of preliminary flourish which would imply a doubt as to the accuracy of the statement made, the secret mode said to have been employed by Dom Perignon to improve his wine, and to have been confided by him a few days before his death to 'a person worthy enough of belief,' by whom it was in turn communicated to the writer. According to this, a pound of sugar-candy was dissolved in a _chopine_ of wine, to which was then added five or six stoned peaches, four sous' worth of powdered cinnamon, a grated nutmeg, and a _demi septier_ of burnt brandy; and the whole, after being well mixed, was strained through fine linen into a _pièce_ of wine immediately after fermentation had ceased, with the result of imparting to it a dainty and delicate flavour. Dom Grossart, however, in his letter to M. Dherbès, distinctly declares that 'we never did put sugar into our wine.'[110] This _collature_, in which peaches play a part, was probably made use of by some wine-growers; and the peach-like flavour extolled by St. Evremond in the wine of Ay may have been due to it, or to the practice then and long afterwards followed of putting peach-leaves in the hot water with which the barrels were washed out, under the idea that this improved the flavour of the wine.[111] Opinions were widely divided as to the cause of the effervescence in the wines of Hautvillers, for the connection between sugar and fermentation was then undreamt of, although Van Helmont had recognised the existence of carbonic acid gas in fermenting wine as early as 1624. Some thought it due to the addition of drugs, and sought to obtain it by putting not only alum and spirits of wine, but positive nastinesses, into their wine.[112] Others ascribed it to the greenness of the wine, because most of that which effervesced was extremely raw; and others again believed that it was influenced by the age of the moon at the epoch of bottling. Experience undoubtedly showed that wine bottled between the vintage and the month of May was certain to effervesce, and that no time was more favourable for this operation than the end of the second quarter of the moon of March. Nevertheless, as the wines, especially those of the Mountain of Reims, were not usually matured at this epoch, it was recommended, in order to secure a ripe and exquisite sparkling wine, to defer the bottling until the ascent of the sap in the vine between the tenth and fourteenth day of the moon of August; whereas, to insure a _non mousseux_ wine, the bottling ought to take place in October or November.[113] The fame of the new wine, known indifferently as _vin de Perignon_, _flacon pétillant_, _flacon mousseux_, _vin sautant_, _vin mousseux_, _saute bouchon_, &c., and even anathematised as _vin du diable_--for the present term, _vin de Champagne_, was confined as yet to the still or quasi-still growths--quickly spread. Never, indeed, was a discovery more opportune. At the moment of its introduction the glory of France was on the wane; Colbert, Louvois, and Luxembourg were dead; the Treaty of Ryswick had been signed; famine and deficit reared their threatening heads, and lo, Providence offered this new consolation for all outward and inward ills. With the King it could only find scant favour. The once brilliant Louis was now a bigoted and almost isolated invalid. His debilitated stomach, ruined by long indulgence, could scarcely even support the old Burgundy--so old that it was almost tasteless--which Fagon had prescribed as his sole beverage some years before;[114] and the popping of sparkling Champagne corks would have scandalised the quiet _tête-à-tête_ repasts which he was wont to partake of with the pious Madame de Maintenon.[115] [Illustration] [Illustration] But the men who were to be the future _roués_ of the Regency were in the flower of youthful manhood in 1698, and the recommendation of Comus had with them more weight than the warnings of Æsculapius. At the joyous suppers of Anet, where the Duc de Vendôme laid aside the laurels of Mars to wreathe his brows with the ivy of Bacchus; at the Temple, where his brother, the Grand Prior, nightly revived the most scandalous features of the orgies of ancient Rome; at the Palais Royal, where the future Regent was inaugurating that long series of _petits soupers_ which were ultimately to cost the lives of himself and his favourite daughter; and at Chantilly, where the Prince de Conti sought successfully to reproduce a younger and brighter Versailles, the pear-shaped flasks, 'ten inches high, including the four or five of the neck,'[116] stamped with the arms of the noble hosts, and secured with Spanish wax,[117] were an indispensable adjunct to the festivities of the table. A story is told of the Marquis de Sillery, who had turned his sword into a pruning-knife, and applied himself to the cultivation of the paternal vineyards, having first introduced the sparkling wine bearing his name at one of the Anet suppers, when, at a given signal, a dozen of blooming young damsels, scantily draped in the guise of Bacchanals, entered the room, bearing apparently baskets of flowers in their hands, but which, on being placed before the guests, proved to be flower-enwreathed bottles of the new sparkling wine.[118] If ever a beverage was intended for the pleasures of society, it was certainly this one, which it was said Nature had made especially for the French,[119] who found in its discovery a compensation for the victories of Marlborough. Chaulieu, the poetic abbé, and the favourite of both the Vendômes, hailed this new product of his native province in rapturous strophes. In an invitation to supper addressed to his friend, the Marquis de la Fare, in 1701, he describes how 'Of fivescore clear glasses the number and brightness Make up for of dishes the absence and lightness, And the foam, sparkling pure, Of fresh delicate wine For Fortune's frail lure Blots out all regret in this memory of mine.'[120] In a letter to St. Evremond, he mentions sundry wonderful things that should happen 'if the Muses were as fond of the wine of Champagne as the poet who writes this to you;' and, in one to the Marquis de Dangeau, jestingly remarks that 'St. Maur's harsher muse All flight will refuse, Unless you sustain Her wings with Champagne.'[121] Replying to an invitation to Sonning's house at Neuilly on July 20, 1707, he says that when he comes it will be wonderful to see how the Champagne will be drained from the tall glasses known as _flutes_.[122] That the Champagne he extols was a sparkling wine is established in a poetical epistle to Madame D., in answer to her complaint that the wine he had sent her did not froth as when they supped together, and in this he also speaks of its newness. His brother-rhymster, Jean Baptiste Rousseau, who must not be confounded with the philosophic Jean Jacques, invited Chaulieu to join him at Neuilly, in mingling the water of Hippocrene with the wine of Hautvillers,[123] and announced to the Champagne-loving Marquis d'Ussé, _apropos_ of the latter's favourite source of inspiration, that even 'Ph[oe]bus will no more go climbing For water up Helicon's mount, But admit, as a source of good rhyming, Champagne excels Hippocrene's fount.'[124] Such general attention did the subject attract that Frederick William II. of Prussia actually proposed to the Academy of Arts and Sciences at Berlin the question, 'Why does Champagne foam?' for solution. The Academicians, with unexpected sharpness, petitioned the King for a supply of the beverage in question on which to experiment. But the parsimonious monarch was equal to the occasion, and a solitary dozen of the wine was all he would consent to furnish them with. His ally, Augustus the Strong of Saxony, was the hero of a ludicrous adventure connected with sparkling Champagne. At a banquet given to him at Dresden, a page, who had surreptitiously appropriated a bottle of this costly beverage, and hidden it in the breast of his coat, had to approach the King. The heat and motion combined had imparted briskness to the wine, out popped the cork, and the embroidered garments and flowing periwig of Mr. Carlyle's 'Man of Sin' were drenched with the foaming liquid. The page fell on his knees and roared for mercy, and the King, as soon as he recovered from his bursts of laughter, freely forgave him his offence. The success of Dom Perignon's wine caused a revolution in the wine-production of the province, and gave rise to numerous imitations, despite the outcry raised against sparkling wine by many _gourmets_, and even by the wine-merchants themselves, who complained that they had to pander to what they regarded as a depraved taste. The elder Bertin du Rocheret, father of the _lieutenant criminel_ and a notable dealer in wine, was much opposed to it.[125] Marshal de Montesquiou d'Artagnan, the gallant assailant of Denain, had ordered some wine of him, and he writes in reply, on November 11, 1711: 'I have chosen three poinçons of the best wine of Pierry at 400 francs the queue, not to be drawn off as _mousseux_--that would be too great a pity. Also a poinçon to be drawn off as _mousseux_ at 250 francs the queue; or, if you will only go as far as 180 francs, it will froth just as well, or better. Also a poinçon of _tocane_ of Ay to be drunk this winter--that is to say, it should be drunk by Shrovetide--at 300 francs the queue: this wine is very fine.'[126] On the 27th December 1712 the Marshal writes: 'With regard to my wine being made _mousseux_, many prefer that it should be so; and I should not be vexed, provided it does not in any way depreciate its quality.' On the 18th October of the following year the stern _laudator temporis acti_ describes how the bottling has been carried out, 'in order that your wines might be _mousseux_, without which I should not have done it, and perhaps you would have found it better, but it would not have had the merit of being _mousseux_, which in my opinion is the merit of a poor wine, and only proper to beer, chocolate, and whipped cream. Good Champagne should be clear and fine, should sparkle in the glass, and should flatter the palate, as it never does when it is _mousseux_, but has a smack of fermentation; hence it is only _mousseux_ because it is working.' The converted Marshal replies on October 25th: 'I was in the wrong to ask you to bottle my wine so that it might be _mousseux_; it is a fashion that prevails everywhere, especially amongst young people. For my own part, I care very little about it; but I wish the wine to be clear and fine, and to have a strong Champagne bouquet.' In the following December Bertin, in answer to the Marshal's request for three quartaux of wine, says: 'Will you kindly let me know at what date you propose to drink this wine? If it is to be drunk as _mousseux_, I shall not agree with you.' The allusion to the time of year at which the wine was to be drunk throws a light upon a practice of the day, confirmed by other passages in this correspondence. Much of the wine made was drunk as _vin bourru_ fined, but not racked off, at the beginning of the year, or as _tocane_, which was apt to go off if kept beyond Shrovetide. This speedy consumption and the careful choice made of the grapes intended for _vin mousseux_ militated against the formation in the bottles of that deposit, which, up to the commencement of the present century, when the system of _dégorgeage_ was introduced, could only be remedied by _dépotage_,[127] though, as we have seen, the Abbey of Hautvillers had a secret method, carefully guarded, of checking its formation.[128] It is singular that the presence of a natural _liqueur_--the consequence of a complete but not excessive ripeness of the grape, and at present considered one of the highest qualities of the wine--was, at the commencement of the eighteenth century, regarded as a disease. The _Mémoire_ of 1718 states that when the wine has any liqueur, however good it may otherwise be, it is not esteemed, and recommends the owner to get rid of this 'bad quality' forthwith by putting a pint of new milk warm from the cow into each _pièce_, stirring it well, letting it rest three days, and then racking the wine off. At this epoch the wine of the Champagne seems to have been preferred perfectly dry.[129] In June 1716 the Marshal d'Artagnan reproached Bertin du Rocheret for sending him Hautvillers wine of the preceding vintage which had turned out _liquoreuse_. However, in August he felt forced to write that it had become excellent, and similar experiences seem to have soon removed all prejudices against this liqueur character. Bertin, in 1725, speaks of it as one of the qualities of wine, and charges for it in proportion; and six years later remarks that the English are as mad for liqueur and colour in their wines as the French.[130] [Illustration] [Illustration] IV. /The Battle of the Wines./ Temporary check to the popularity of Sparkling Champagne--Doctors disagree--The champions of Champagne and Burgundy--Péna and his patient--A young Burgundian student attacks the Wine of Reims--The Faculty of Reims in arms--A local Old Parr cited as an example in favour of the Wines of the Champagne--Salins of Beaune and Le Pescheur of Reims engage warmly in the dispute--A pelting with pamphlets--Burgundy sounds a war-note--The Sapphics of Benigné Grenan--An asp beneath the flowers--The gauntlet picked up--Carols from a Coffin--Champagne extolled as superior to all other wines--It inspires the heart and stirs the brain--The apotheosis of Champagne foam--Burgundy, an invalid, seeks a prescription--Impartially appreciative drinkers of both wines--Bold Burgundian and stout Rémois, each a jolly tippling fellow--Canon Maucroix's parallel between Burgundy and Demosthenes and Champagne and Cicero--Champagne a panacea for gout and stone--Final decision in favour of Champagne by the medical faculty of Paris--Pluche's opinion on the controversy--Champagne a lively wit and Burgundy a solid understanding--Champagne commands double the price of the best Burgundy--Zealots reconciled at table. By a strange fatality the popularity of the sparkling wine of the Champagne, which had helped to dissipate the gloom hanging over court and capital during the last twenty years of the reign of Louis Quatorze,[131] began to wane the year preceding that monarch's death.[132] Dom Perignon too, as though stricken to the heart by this, forthwith drooped and died. The inhabitants of the province once more turned their attention to their red wines, which continued to enjoy a high reputation during the first half of the century,[133] despite the sweeping assertion that they were somewhat dry, rather flat, and possessed a strong flinty flavour,[134] the _goût de terroir_ alluded to by St. Evremond. [Illustration] These red wines were not only sent to Paris in large quantities by way of the Marne,[135] but commanded an important export trade, those of the Mountain, which were better able to bear the journey than the growths of the River, gracing the best-appointed tables of London, Amsterdam, Copenhagen, and the North,[136] and especially of Flanders, where they were usually sold as Burgundy.[137] It must not be lost sight of that the yield of white sparkling wine from the _crûs d'élite_ was for a long time comparatively small, especially when contrasted with that of to-day.[138] At a later period the manufacture of _vin mousseux_ increased, notably in the districts south of the Marne,[139] and drove out almost entirely the still red wine; the place of the latter being supplied, as regards Holland, Belgium, and Northern France, by the growths of Bordeaux, which were found to keep better in damp climates.[140] [Illustration] One cause of this falling off in the popularity of the sparkling wine arose from the great battle which raged for many years respecting the relative merits of Champagne and Burgundy. It was waged in the schools, and not in the field; for the combatants were neither dashing soldiers, brilliant courtiers, nor even gay young students, but potent, grave, and reverend physicians--the wigged, capped, and gowned pedants of the Diaphorus type whom Molière so piteously pilloried. The only blood shed was that of the grape, excepting when some enthusiastic Sangrado was impelled by a too conscientious practical examination into the qualities of the vintage he championed to a more than ordinary reckless use of the lancet. The contending armies couched pens instead of lances, and marshalled arguments in array in place of squadrons. They hurled pamphlets and theses at each others' heads in lieu of bombshells, and kept up withal a running fire of versification, so that the rumble of hexameters replaced that of artillery. [Illustration] National pride, and perhaps a smack of envy at the growing popularity of the still red wines of the Champagne, had, as far back as 1652, led a hot-headed young Burgundian, one Daniel Arbinet, to select as the subject of a thesis, maintained by him before the schools of Paris, the proposition that the wine of Beaune was more delicious and more wholesome than any other wine,[141] the remaining vintages of the universe being pretty roughly handled in the thesis in question. The Champenois contented themselves for the time being with cultivating their vineyards and improving their wines, till in 1677, when these latter had acquired yet more renown, M. de Révélois of Reims boldly rushed into print with the assertion that the wine of Reims was the most wholesome of all.[142] Though the first to write in its favour, he was not the first doctor of eminence who had expressed an opinion favourable to the wine of Champagne. Péna, a leading Parisian physician of the seventeenth century, was once consulted by a stranger. 'Where do you come from?' he inquired. 'I am a native of Saumur.' 'A native of Saumur. What bread do you eat?' 'Bread from the Belle Cave.' 'A native of Saumur, and you eat bread from the Belle Cave. What meat do you get?' 'Mutton fed at Chardonnet.' 'A native of Saumur, eating bread from the Belle Cave and mutton fed at Chardonnet. What wine do you drink?' 'Wine from the Côteaux.'[143] 'What! You are a native of Saumur; you eat bread from the Belle Cave, and mutton fed at Chardonnet, and drink the wine of the Côteaux, and you come here to consult me! Go along; there can be nothing the matter with you!'[144] Burgundy remained silent in turn for nearly twenty years, when, lo, in 1696--probably just about the time when the popping of Dom Perignon's corks began to make some noise in the world--a yet more opinionated young champion of the Côte d'Or, Mathieu Fournier, a medical student, hard pressed for the subject of his inaugural thesis, and in the firm faith that 'None but a clever dialectician Can hope to become a good physician, And that logic plays an important part In the mystery of the healing art,' propounded the theory that the wines of Reims irritated the nerves, and caused a predisposition to catarrh, gout, and other disorders, owing to which Fagon, the King's physician, had forbidden them to his royal master.[145] [Illustration: LOUIS XIV. (From a portrait of the time).] Shocked at these scandalous assertions, the entire Faculty of Medicine at the Reims University rose in arms in defence of their native vintage. Its periwigged professors put their learned heads together to discuss the all-important question, 'Is the wine of Reims more agreeable and more wholesome than the wine of Burgundy?' and in 1700 Giles Culotteau embodied their combined opinions in a pamphlet published under that title.[146] After extolling the liquid purity, the excellent brightness, the divine flavour, the paradisiacal perfume, and the great durability of the wines of Ay, Pierry, Verzy, Sillery, Hautvillers, &c., as superior to those of any growth of Burgundy, he instanced the case of a local Old Parr named Pierre Pieton, a _vigneron_ of Hautvillers, who had married at the age of 110, and reached that of 118 without infirmity, as a convincing proof of the material advantages reaped from their consumption. [Illustration] [Illustration: ANCIENT TOWER OF REIMS UNIVERSITY.] Salins, the _doyen_ of the Faculty of Medicine of Beaune, was intrusted with the task of replying, and in 1704 bitterly assailed Culotteau's thesis in a 'Defence of the Wine of Burgundy against the Wine of Champagne,' which ran to five editions in four years. M. le Pescheur, a doctor of Reims, vigorously attacked each of these editions in succession, maintaining amongst other things that the wine of Reims owed its renown to the many virtues discovered in it by the great lords who had accompanied Louis XIV. to his coronation; and that if the King, on the advice of his doctors, had renounced its use, his courtiers had certainly not. He also asserted that England, Germany, and the North of Europe consumed far more Champagne than they did Burgundy, and that it would be transported without risk to the end of the world, Tavernier having taken it to Persia, and another traveller to Siam and Surinam. [Illustration] [Illustration] The partisanship quickly spread throughout the country, and the respective admirers of Burgundy and Champagne pitilessly pelted each other in prose and verse; for the two camps had their troubadours, who, like those of old, excited the courage and ardour of the combatants. The first to sound the warlike trumpet was Benigné Grenan, professor at the college of Harcourt, who, with the rich vintage of his native province bubbling at fever-heat through his veins, sought in 1711 to crush Champagne by means of Latin sapphics, a sample of which has been thus translated: 'Lift to the skies thy foaming wine, That cheers the heart, that charms the eye; Exalt its fragrance, gift divine, Champagne, from thee the wise must fly! A poison lurks those charms below, An asp beneath the flowers is hid; In vain thy sparkling fountains flow When wisdom has their lymph forbid. 'Tis, but when cloyed with purer fair We can with such a traitress flirt; So following Beaune with reverent air, Let Reims appear but at dessert.'[147] The gauntlet thus contemptuously thrown down was promptly and indignantly picked up by the Rector of the University of Beauvais, the learned Dr. Charles Coffin, a native of Buzancy, near Reims, who in the quiet retirement of the Picardian _Alma Mater_ had evidently not forgotten to keep up his acquaintance with the vintage of his native province. The Latin poem he produced in reply, under the title of _Campania vindicata_,[148] had nothing in common with his lugubriously sepulchral name, as may be seen by the following somewhat freely translated extracts from it. After invoking the aid of a bottle of the enlivening liquor whose praises he is about to sing, he exclaims: 'As the vine, although lowly in aspect, outshines The stateliest trees by the produce it bears, So midst all earth's list of rich generous wines, Our Reims the bright crown of preëminence wears. The Massica, erst sang by Horace of old, To Sillery now must abandon the field; Falernian, nor Chian, could ne'er be so bold To rival the nectar Ay's sunny slopes yield. As bright as the goblet it sparklingly fills With diamonds in fusion, it foaming exhales An odour ambrosial, the nostril that thrills, Foretelling the flavour delicious it veils. At first with false fury the foam-bells arise, And creamily bubbling spread over the brim, Till equally swiftly their petulance dies In a purity that makes e'en crystal seem dim.'[149] [Illustration] Praising the flavour of this nectar, which he declares is in every way worthy of its appearance, he stoutly defends the wine from the charge of unwholesomeness adduced against it by Grenan: 'Despite the tongue of malice, No poison in thy chalice Was ever found, Champagne! Simplicity most loyal Was e'er thy boast right royal, And this thy wines retain. No harm lurks in the fire That helps thee to inspire The heart and spur the brain.'[150] [Illustration] So far from causing inconvenience, he claims for Champagne the property of keeping off both gout and gravel, neither of which, he says, is known in Reims and its neighbourhood, and continues: 'When on the fruit-piled board, Thy cups, with nectar stored, Commence their genial reign, The wisest, sternest faces Of mirth display the traces, And to rejoice are fain. As laughter's silv'ry ripple Greets every glass we tipple. Away fly grief and pain.'[151] The jovial old rector with the sepulchral appellation then proceeds, according to the most approved method of warfare, to carry the campaign into the enemy's territory. He admits the nutritive and strengthening properties of Burgundy, but demands what it possesses beyond these, which are shared in common with it by many other vintages. He then prophesies, with the return of peace,[152] the advent of the English to buy the wine of Reims; and concludes by wishing that all who dispute the merits of Champagne may find nothing to drink but the sour cider of Normandy or the acrid vintage of Ivri. The citizens of Reims, thoroughly alive to the importance of the controversy, were enchanted with this production; they did not, however, crown the poet with laurel, but more wisely and appropriately despatched to him four dozen of their best red and gray wines, by the aid of which he continued to tipple and to sing. Grenan, resuming the offensive in turn, at once addressed an epistle in Latin verse, in favour of Burgundy against Champagne, to Fagon, the King's physician.[153] Complaining that the latter wine lays claim unjustly to the first rank, he allows it certain qualities--brilliancy, purity, limpidity, a subtle savour that touches the most blunted palate, and an aroma so delicious that it is impossible to resist its attractions. But he objects to its pretensions. 'Its vinous flood, with swelling pride In foaming wavelets welling up, Pours forth its bright and sparkling tide, Bubbling and glittering in the cup.'[154] He goes on to accuse the Champenois poet of being unduly inspired by this wine, the effects of which he finds apparent in his inflated style and his attempts to place Champagne in the first rank, and make all other vintages its subjects; and he reiterates his allegations that, unlike Burgundy, it affects both the head and the stomach, and is bound to produce gout and gravel in its systematic imbibers. He concludes by begging Fagon to pronounce in his favour, as having proved the virtues of Burgundy on the King himself, whose strength had been sustained by it. The retort was sharp and to the point, taking the form of a twofold epigram from an anonymous hand: 'To the doctor to go On behalf of your wine Is, as far as I know, Of its sickness a sign. Your cause and your wine Must be equally weak, Since to check their decline A prescription you seek.'[155] Nor was the poet of the funereal cognomen backward in stepping into the field; for he published a metrical decree, supposed to be issued by the faculty of the island of Cos in the fourth year of the ninety-first Olympiad,[156] in which, though a verdict is nominally given in favour of Burgundy, Grenan's pleas on behalf of this wine are treated with withering sarcasm. But whilst these enthusiastic partisans thus belaboured one another, there were not wanting impartial spirits who could recognise that there were merits on both sides. Bellechaume, in an ode jointly addressed to the two combatants,[157] adjures them to live at peace on Parnassus, and, remembering that Horace praised both Falernian and Massica, to jointly animate their muse with Champagne and Burgundy: 'To learn the difference between The wine of Reims and that of Beaune, The fairest plan would be, I ween, To drink them both, not one alone.'[158] Another equally judicious versifier called also on the Burgundian champion[159] to cease the futile contest, since 'Bold Burgundian ever glories With stout Remois to get mellow; Each well filled with vinous lore is Each a jolly tippling fellow.'[160] And the learned Canon Maucroix of Reims exhibited a similar conciliatory spirit in the ingenious parallel which he drew between the two greatest orators of antiquity and the wines of the Marne and the Côte d'Or. 'In the wine of Burgundy,' he observes, 'there is more strength and vigour; it does not play with its man so much, it overthrows him more suddenly,--that is Demosthenes. The wine of Champagne is subtler and more delicate; it amuses more and for a longer time, but in the end it does not produce less effect,--that is Cicero.'[161] [Illustration: REMAINS OF THE GATE OF BACCHUS, NEAR REIMS UNIVERSITY.] The national disasters which marked the close of the reign of Louis XIV. diverted public attention in some degree from the nugatory contest;[162] and though Fontenelle sought to prove that a glass of Champagne was better than a bottle of Burgundy,[163] the impartially appreciative agreed with Panard that 'Old Burgundy and young Champagne At table boast an equal reign.'[164] But the doctors continued to disagree, and new generations of them still went on wrangling over the vexed questions of supremacy and salubrity. In 1739 Jean François carried the war into the enemy's camp by maintaining at Paris that Burgundy caused gout; and a little later Robert Linguet declared the wine of Reims to be as healthy as it was agreeable. In 1777 Xavier, Regent of the Faculty of Medicine at the Reims University, affirmed that not only did the once vilified _vin mousseux_ share with the other wines of the Champagne the absence of the tartarous particles which in many red wines are productive of gout and gravel, but that the gas it contained caused it to act as a dissolvent upon stone in the human body, and was also invaluable, from its antiseptic qualities, in treating putrid fevers.[165] Further, the appropriately named Champagne Dufresnay established, to his own satisfaction and that of his colleagues, that the wine was superior to any other growth, native or foreign.[166] At length, in 1778, when the bones of the original disputants were dust, and their lancets rust, on the occasion of a thesis being defended before the Faculty of Medicine of Paris, a verdict was formally pronounced by this body in favour of the wine of the Champagne.[167] [Illustration] [Illustration] V. /Progress and Popularity of Sparkling Champagne./ Sparkling Champagne intoxicates the Regent d'Orléans and the _roués_ of the Palais Royal--It is drunk by Peter the Great at Reims--A horse trained on Champagne and biscuits--Decree of Louis XV. regarding the transport of Champagne--Wine for the _petits cabinets du Roi_--The _petits soupers_ and Champagne orgies of the royal household--A bibulous royal mistress--The Well-Beloved at Reims--Frederick the Great, George II., Stanislas Leczinski, and Marshal Saxe all drink Champagne--Voltaire sings the praises of the effervescing wine of Ay--The Commander Descartes and Lebatteux extol the charms of sparkling Champagne--Bertin du Rocheret and his balsamic molecules--The Bacchanalian poet Panard chants the inspiring effects of the vintages of the Marne--Marmontel is jointly inspired by Mademoiselle de Navarre and the wine of Avenay--The Abbé de l'Attaignant and his fair hostesses--Breakages of bottles in the manufacturers' cellars--Attempts to obviate them--The early sparkling wines merely _crémant_--_Saute bouchon_ and _demi-mousseux_--Prices of Champagne in the eighteenth century--Preference given to light acid wines for sparkling Champagne--Lingering relics of prejudice against _vin mousseux_--The secret addition of sugar--Originally the wine not cleared in bottle--Its transfer to other bottles necessary--Adoption of the present method of ridding the wine of its deposit--The vine-cultivators the last to profit by the popularity of sparkling Champagne--Marie Antoinette welcomed to Reims--Reception and coronation of Louis XVI. at Reims--'The crown, it hurts me!'--Oppressive dues and tithes of the _ancien régime_--The Fermiers Généraux and their hôtel at Reims--Champagne under the Revolution--Napoleon at Epernay--Champagne included in the equipment of his satraps--The Allies in the Champagne--Drunkenness and pillaging--Appreciation of Champagne by the invading troops--The beneficial results which followed--Universal popularity of Champagne--The wine a favourite with kings and potentates--Its traces to be met with everywhere. [Illustration] Whilst doctors went on shaking their periwigged heads, and debating whether sparkling Champagne did or did not injure the nerves and produce gout, the timid might hearken to their counsels, but there were plenty of spirits bold enough to let the corks pop gaily, regardless of all consequences. The wine continued in high favour with the _viveurs_ of the capital, and especially with the brilliant band of titled scoundrels who formed the Court of Philippe le Débonnaire. 'When my son gets drunk,' wrote, on the 13th August 1716, the Princess Charlotte Elizabeth of Bavaria, the Regent's mother, 'it is not with strong drinks or spirituous liquors, but pure wine of Champagne;'[168] and as the pupil of the Abbé Dubois very seldom went to bed sober,[169] he must have consumed a fair amount of the fluid in question in the course of his career. Even his boon companion, the Duke de Richelieu, is forced to admit that there was a great deal more drunkenness about him than was becoming in a Regent of France; and that, as he could not support wine so well as his guests, he often rose from the table drunk, or with his wits wool-gathering. 'Two bottles of Champagne,' remarks the duke in his _Chronique_, 'had this effect upon him.' Desirous, seemingly, that such enjoyments should not be confined to himself alone, he abolished in 1719 sundry dues on wine in general, whilst his famous, or rather infamous, suppers conduced to the vogue of that sparkling Champagne which was an indispensable accompaniment of those _décolleté_ repasts. It unloosed the tongues and waistcoats of the _roués_ of the Palais Royal, the Nocés, Broglios, Birons, Brancas, and Canillacs; it lent an additional sparkle to the bright eyes of Mesdames de Parabère and de Sabran, and inspired the scathing remark from the lips of one of those fair frail ones, that 'God, after having made man, took up a little mud, and used it to form the souls of princes and lackeys.' It played its part, too, at the memorable repast at which the Regent and his favourite daughter so scandalised their hostess, the Duchess of Burgundy, and at the fatal orgie shared by the same pair on the terrace of Meudon. [Illustration: THE REGENT D'ORLÉANS (From the picture by Santerre).] The example set in such high quarters could not fail to be followed. Champagne fired the sallies of the wits and versifiers whom the Duchess of Maine gathered around her at Sceaux, and stimulated the madness which seized upon the whole of Paris at the bidding of the financier Law. It frothed, too, in the goblets which Bertin du Rocheret had the honour of filling with his own hand for Peter the Great, on the passage of the Northern Colossus through Reims in June 1717; and its consumption was increased by a decree of 1728, which especially provided that people proceeding to their country seats might take with them for their own use a certain quantity of this wine free of duty. A curious purpose to which the wine was applied appeared from a wager laid by the Count de Saillans--one of the most famous horsemen of his day, and already distinguished by similar feats--to the effect that he would ride a single horse from the gate of Versailles to the Hôtel des Invalides within an hour. His wife, fearing the dangerous descent from Sèvres towards Paris, prevailed on the King to prohibit him from riding in person; but a valet, whose neck was of course of no moment, was allowed to act as his deputy in essaying the feat. The horse selected was carefully fed for some days beforehand on biscuits and Champagne. Crowds assembled to witness the attempt, which was made on May 9, 1725, and resulted in the valet's coming in two and a half minutes behind time. Whether this was due to the badness of the roads, as was alleged, or to the singular _régime_ adopted for the animal selected, remains a moot question.[170] Champagne won equal favour in the eyes of Louis XV., as in those of the curious compound of embodied vices who had watched over the welfare of the kingdom during his minority, though it is true that at a comparatively early age--in the year 1731--he had, on representations that over-production of wine was lowering its value, prohibited the planting of fresh vineyards without his permission under a penalty of 3000 francs, and had renewed this prohibition the year following.[171] [Illustration: LOUIS XV. WHEN YOUNG (From a picture of the epoch).] [Illustration: A FRENCH COUNTRY INN OF THE EIGHTEENTH CENTURY (From the 'Routes de France').] The royal repasts at La Muette, Marly, and Choissy were, however, enlivened with wine from the Champagne; for we find Bertin du Rocheret in 1738 despatching thirty pieces of the still wine to M. de Castagnet for the _petits cabinets du Roi_,[172] and the eldest of the fair sisters La Nesle, Madame de Mailly, the 'Queen of Choissy' and _maîtresse en titre_, in 1740 reforming the cellar management, and suppressing the _petits soupers_ and Champagne orgies of the royal household.[173] Her conduct in this respect seems, however, not to have been dictated by motives of virtue, but rather by the conviction that the wine was too precious to be consumed by inferiors. We are assured that the countess loved wine, and above all that of Champagne, and that she could hold her own against the stoutest toper. 'She has been reproached with having imparted this taste to the King, but it is probable that his Majesty was naturally inclined that way.'[174] [Illustration: UN PETIT SOUPER OF THE EIGHTEENTH CENTURY (From the collection of the 'Chansons de Laborde').] When, in 1741, the 'Well-Beloved' passed through Reims, Dom Chatelain, after rejoicing over the year's vintage having been a very fine one, adds that it was drunk to a considerable extent and with the greatest joy in the world during the ten days that the King remained in the city. 'It was no longer a question,' he exclaims exultingly, 'of sending for Burgundy or Laon wine.' Three years later, when traversing the Champagne, on his way to Metz, he again halted at Reims; and after hearing mass, 'retired to the Archevêché, where the Corps de la Ville presented his Majesty with the wines of the town, which he ordered to be taken to his apartments.'[175] Wine was also presented to the Prince de Soubise, Governor of the Champagne; the Duke de Villeroy, M. d'Argenson, and the Count de Joyeuse; whilst, for the benefit of the populace, four fountains of the same fluid flowed at the corners of the Place de l'Hôtel de Ville.[176] In like manner, at the inauguration of that 'brazen lie,' the statue of this same Louis XV., in 1767, wine flowed in rivers from the different fountains of the city.[177] The satyr-like sovereign of France was by no means the only monarch of his time who appreciated sparkling Champagne. Frederick the Great has praised its consoling powers in the doggerel which Voltaire was engaged to turn into poetry; and George II. of England at St. James's, and Stanislas Leczinski of Poland at Nancy, both quaffed of the same vintage of Ay despatched in 1754 from the cellars of Bertin du Rocheret. Marshal Saxe, during his sojourn in 1745 at Brussels, where he held a quasi-royal court, of which Mademoiselle de Navarre was the bright particular star, drew an ample supply of Champagne from the cellars of that lady's father, Claude Hevin de Navarre of Avenay, who had established himself as a wine merchant in the Belgian capital.[178] Despite, too, the continued outcry of some connoisseurs,[179] the _vin mousseux_ became the universal source of inspiration for the cabaret-haunting poets of that graceless witty epoch.[180] Voltaire, all unmoved by the excellent still Champagne with which he and the Duke de Richelieu had been regaled at Epernay by Bertin du Rocheret in May 1735, persisted in singing the praises of the effervescing wine of Ay, in the sparkling foam of which he professed to find the type of the French nation:[181] 'Chloris and Eglé, with their snowy hands, Pour out a wine of Ay, whose prisoned foam, Tightly compressed within its crystal home, Drives out the cork; 'midst laughter's joyous sound It flies, against the ceiling to rebound. The sparkling foam of this refreshing wine The brilliant image of us French does shine.' The Commander Descartes seems not to have been afraid to extol the charms of the sparkling wine to the younger Bertin du Rocheret, as stern a decrier of its merits as his father had previously been. In a letter dated December 1735, asking for 'one or two dozen bottles of sparkling white wine, neither _vert_ nor _liquoreux_, "I should like," he says, "some Of that delectable white wine Which foams and sparkles in the glass, And seldom mortal lips does pass; But cheers, at festivals divine, The gods to whom it owes its birth, Or else the great, our gods on earth."'[182] Amongst other versifiers of this epoch enamoured with the merits of the wine may be cited Charles Lebatteux, professor of rhetoric at Reims University, who in 1739 composed an ode, 'In Civitatem Remensam,' containing the following invocation to Bacchus: ''Tis not on the icy-topped mountains of Thrace, Or those of Rhodope, thy favours I trace-- Not there to invoke thee I'd roam. No! Reims sees thee reign sovereign lord o'er her hills; There I offer my vows, and the nectar that thrills To my soul I will seek close at home. Whether Venus-like rising midst foam sparkling white, Or wrapped in a mantle of rose rich and bright, Thou seekest my senses to fire, Come aid me to sing, for my Muse is full fain To owe on this day each melodious strain To the fervour 'tis thine to inspire.'[183] Bertin du Rocheret, who by no means shared his friend Voltaire's admiration for the sparkling vintage of Ay, sang the praises of the still wine of the Champagne after the following fashion in 1741: 'No, such blockheads do not sip Of that most delicious wine; Soul of love and fellowship, Sweet as truly 'tis benign. No, their palate, spoilt and worn, Craves adult'rate juice to drain; Poison raw which we should scorn, Beverage fit for frantic brain. Let us, therefore, hold as fools Such as now feign to despise Those _balsamic molecules_ Horace used to sing and prize. No, such blockheads do not sip Of that most delicious wine; Soul of joy and fellowship, Sweet as truly 'tis benign. Of that wine, so purely white, Which the sternest mood makes pass, And which sparkles yet more bright In your eyes than in my glass. Drink, then, drink; I pledge you, dear, In the nectar old we prize; Sparkling in our glasses clear, But more brightly in your eyes.'[184] [Illustration] Marmontel, the author of _Bélisaire_ and editor of the _Mercure de France_, found inspiration in his youthful days in the sparkling wine of Champagne. He describes, in somewhat fatuous style, the results of an invitation he received from Mademoiselle de Navarre to pass some months with her in 1746 at Avenay, where her father owned several vineyards, and where, she added, 'It will be very unfortunate if with me and some excellent vin de Champagne you do not produce good verses.' He tells how, in stormy weather, she insisted, on account of her fear of lightning, on dining in the cellars, where, 'in the midst of fifty thousand bottles of Champagne, it was difficult not to lose one's head;' and how he was accustomed to read to her the verses thus jointly inspired when seated together on a wooded hillock, rising amidst the vineyards of Avenay.[185] The foregoing in some degree recalls the circumstances under which Gluck, whose fame began to be established about this epoch, was accustomed to seek his musical inspirations. The celebrated composer of _Orpheus_ and _Iphegenia in Aulis_ was wont, when desirous of a visit from the 'divine afflatus,' to seat himself in the midst of a flowery meadow with a couple of bottles of Champagne by his side. By the time these were emptied, the air he was in search of was discovered and written down. The lively and good-humoured Abbé de l'Attaignant, whose occupations as a canon of Reims Cathedral seem to have allowed him an infinite quantity of spare time to devote to versifying, addressed some rather indifferent rhymes to Madame de Blagny on the cork of a bottle of Champagne exploding in her hand;[186] and in some lines to Madame de Boulogne, on her pouring out Champagne for him at table, he maintains that the nectar poured out by Ganymede to Jupiter at his repasts must yield to this vintage.[187] That boon convivialist Panard--who flourished at the same epoch, and was one of the chief songsters of the original Caveau, and a man of whom it was said that, 'when set running, the tide of song flowed on till the cask was empty'--has not neglected sparkling Champagne in his Bacchanalian compositions. The 'La Fontaine of Vaudeville,' as Marmontel dubbed him, does not hesitate to admit that he preferred the popping of Champagne corks to the martial strains of drum and trumpet.[188] The wine, moreover, furnishes him with frequent illustrations for his code of careless philosophy. 'Doctor for vintner vials fills Most carefully, with lymph of wells. Champagne, that grew on Nanterre's hills, Vintner in turn to doctor sells. So still we find, as on we jog Throughout the world, 'tis dog bite dog.'[189] Elsewhere Panard gives expression to the Bacchanalian sentiment, which he seems to have made his rule of life, in the following terms: 'Let's quit this vain world, with its pleasures that cloy, A destiny tranquil and sweet to enjoy: Descend to my cellar, and there taste the charms Of Champagne and Beaune; Our pleasure will there be without the alarms Of any joy queller; For the _ennui_ that often mounts up to the throne Will never descend to the cellar.'[190] The poet appears to have rivalled one of the characters in his piece, _Les Festes Sincères_ (represented on the 5th October 1744 on the occasion of the King's convalescence), who, after describing how wine was freely proffered to all comers, said that he had contented himself with thirty glasses, 'half Burgundy and half Champagne.' In a piece of verse entitled 'La Charme du Vaudeville à Table,' Panard sketches in glowing colours the inspiriting effect of sparkling Champagne upon such a joyous company of periwigged beaux and patched and powdered beauties as we may imagine to be assembled at the hospitable board of some rich financier of the epoch. ''Tis then some joyous guest A flask, filled with the best Of Reims or Ay, securely sealed, holds up; He deftly cuts the string, Aloft the cork takes wing; The rest with eager eyes Thrust glasses t'wards the prize, And watch the nectar foaming o'er the cup. They sip, they drink, they laugh, And then anew they quaff Their bumpers, crowned above the brim with foam That gives to laughter birth, And makes fresh bursts of mirth. Its spirit and its fire Unto the brain aspire, And rouse the wit of which this is the home.'[191] [Illustration] To its praise he also devotes a poetic _tour de force_, the concluding verses of which may thus be rendered: 'Thanks to the bowl That cheers my soul, No care can make me shrink. The foam divine Of this gray wine,[192] I think, When it I drain, Gives to each vein A link. Source of pure joy, Without alloy, Come, dear one, fain I'd drink! Divine Champagne, All grief and pain In thee I gladly sink. All ills agree Away from thee To slink. Sweet to the nose As new-blown rose Or pink. With gifts that ease And charms that please, Come, dear one, fain I'd drink!'[193] Despite the success achieved by the _vin mousseux_, merchants, owing to the excessive breakage of the bottles--of the cause of which and of the means of stopping it they were equally ignorant--often saw their hopes of fortune fly away with the splintered fragments of the shattered glass.[194] The following passages from the /MS./ notes of the founder of one of the first houses of Reims, written in 1770, would imply some knowledge of the fact that a _liquoreux_ wine was likely to lead to a destructive _casse_, and also that the importance of the trade in sparkling Champagne was far greater during the first half of the eighteenth century than is usually supposed.[195] The /MS./ in question says: 'In 1746 I bottled 6000 bottles of a very _liquoreux_ wine; I had only 120 bottles of it left. In 1747 there was less _liqueur_; the breakage amounted to one-third of the whole. In 1748 it was more vinous and less _liquoreux_; the breakage was only a sixth. In 1759 it was more _rond_, and the breakage was only a tenth. In 1766 the wine of Jacquelet was very _rond_; the breakage was only a twentieth.'[196] The writer then proceeds to recommend, as a means of preventing breakage, that the wine should not be bottled till the _liqueur_ had almost disappeared, and that, if necessary, fermentation should be checked by well beating the wine. But as at that epoch there was really no means of effectually testing this disappearance, and as the beating theory was an utterly fallacious one, the followers of his precepts remained with the sad alternative of producing in too many instances either _mousses folles_ and their inevitable accompaniment of disastrous breakage, or wine so mature as to be incapable of continuing its fermentation in bottle, and producing _mousse_ at all.[197] It is therefore evident that much of the sparkling wine drunk at the commencement of the last century was what we should call _crémant_, or, as it was then styled, _sablant_,[198] as otherwise the breakage would have been something frightful. Bertin du Rocheret plainly indicates after 1730 a difference between the fiercely frothing kinds, to which the term _saute bouchon_ or pop-cork was applied, and wine that was merely _mousseux_.[199] The price of the former is the highest, ranging up to 3 livres 6 sols, whilst that of the _bon mousseux_ does not exceed 50 sols, the difference in the two being no doubt based to a certain extent on the loss by breakage.[200] Hence, too, a partiality for weak sour growths for making _vin mousseux_, as, although science could give no reason, experience showed that with these the breakage would be less than with those of a saccharine nature.[201] Thus Bertin writes in 1744 that the vineyards of Avize, planted for the most part in 1715, and almost entirely with white grapes, only produced a thin wine, with a tartness that caused it to be one of the least esteemed in the district; but that 'since the mania for the _saute bouchon_, that abominable beverage, which has become yet more loathsome from an insupportable acidity,' the Avize wines had increased in value eightfold.[202] To this acidity the Abbé Bignon refers in a poem of 1741, in which, protesting against the partiality for violently effervescing wines, he says: 'Your palate is a cripple Worn out by fiery tipple, Or else it would prefer juice Of grapes to fizzing verjuice.'[203] This serves to explain the preference so long accorded by _gourmets_ to the finer _non mousseux_ wines, full of aroma and flavour, and often sugary and _liquoreux_, but looked upon by the general public up to the close of the eighteenth century as inferior to those which were sharp, strong, and even sourish, but which effervesced well.[204] Lingering relics of prejudice against sparkling wine existed as late as 1782, when that conscientious observer, Legrand d'Aussy, remarked that since it had been known that sparkling wines were green wines bottled in spring, when the universal revolution of Nature causes them to enter into fermentation, they had not been so much esteemed, the _gourmets_ of that day preferring those which did not sparkle.[205] It was not till the close of the eighteenth century that any attempt was openly made to improve sparkling Champagne by the addition of sugar.[206] Science then came forward to prove that such an addition was not contrary to the nature of wine, and that fermentation converted the saccharine particles of the must into alcohol, and increased the vinosity.[207] Several growers began to profit by this discovery of Chaptal, though, as a rule, those who followed his recommendations in secret were loudest in asserting that Providence alone had rendered their wine better than that of their neighbours.[208] M. Nicolas Perrier of Epernay, an ex-monk of Prémontré, pointed out, at the beginning of the present century, that up to that period sugar was only regarded as a means of rendering the wine more pleasant to drink, and had always been added after fermentation, and as late as possible. This practice was favoured by the tyrannical routine reigning among the peasants of not tasting the wine till December or January, when in 1800 a decisive experience confirmed the value of the new discoveries. Numerous demands for wine during the vintage led to anticipations of a brisk and speedy sale, and sugar was thereupon added at the time of the first fermentation, merely with the view, however, of bringing the wine more forward for the buyer to taste. The result went beyond the expectations entertained; and at Ay wines of the second class, commonly called _vins de vignerons_, rose to a price previously unheard of.[209] The present system of clearing the wine in bottles was not practised formerly. People were then not so particular about its perfect limpidity; besides which the wine consumed at the beginning of the year[210] had not time to deposit, and that bottled as _mousseux_, owing to its being originally made from carefully-selected grapes, formed very little sediment in the flask.[211] The method of _collage_ employed at the Abbey of Hautvillers is said to have preserved the wines from this evil. Whether this method transpired, or other people discovered it, is unknown; but certainly Bertin du Rocheret transmitted it, or something very similar, in July 1752 to his correspondent in London, who bottled Champagne wines regularly every year.[212] The necessity of ridding the wine of the deposit which deprived it of its limpidity was, however, recognised later on. At first no other method suggested itself, excepting to _dépoter_ it--that is, to decant it into another bottle; a plan fraught, in the case of sparkling wines, with several disadvantages. At the commencement of the present century, however, the system of _dégorgeage_ was substituted.[213] As at first practised, each bottle was held neck downwards, and either shaken or tapped at the bottom to detach the sediment, the operation being constantly repeated until the deposit had settled in the neck, when it was driven out by the force of the explosion which followed upon the removal of the cork. Somewhat later the plan now followed of placing the bottles in sloping racks and turning them every day was adopted, to the great saving of time and labour. Its discovery has been popularly attributed to Madame Clicquot; but the fact is the suggestion emanated from a person in her employ named Müller. The idea is said to have simultaneously occurred to a workman in Marizet's house of the name of Thommassin. Although the advent of such a delectable beverage as sparkling Champagne proved of much benefit to the world in general, and the wine-merchants of Reims and Epernay in particular, those most immediately concerned in its production had little or no reason to rejoice over its renown. The hapless peasants, from whose patches of vineyard it was to a great extent derived, were the last to profit by its popularity. Bidet, writing in 1759, foreshadows the misery which marked the last thirty years of the _ancien régime_.[214] Speaking of the important trade in wine carried on by the city of Reims, he urges that this would in reality be benefited by the old decrees, prohibiting the planting of new vineyards in the Champagne, being enforced to the letter. Extensive plantations of vines in land suitable for the growth of corn had doubled and even tripled the value of arable land, and caused a rise in the price of wheat. Manure, so necessary to bring these new plantations into bearing, and wood, owing to the demand for vine-stakes, barrel-staves, &c., had risen to thrice their former value. Recent epidemics had cost the lives of a large number of vine-dressers, and public _corvées_ occupied the survivors a great part of the year, and hence a considerable increase in the cost of cultivation, landowners having to pay high wages to labourers from a distance. 'Putting together all these excessive charges, with the crushing dues levied in addition upon vine-land as well as upon the sale and transport of wine, the result will infallibly be that the more profitable the wine-trade formerly was to Reims and to the vineyards of the environs, the more it will languish in the end, till it becomes a burden to all the vineyard owners.' Happily these gloomy forebodings have since been completely falsified. [Illustration: THE ARMS OF REIMS ON THE PORTE DE PARIS.] Reims accorded an enthusiastic welcome to the youthful and ill-fated Marie Antoinette, on her passage through the city on May 12, 1770, shortly after her arrival in France;[215] and five years subsequently the Rémois were regaled with the splendours of a coronation, when the young King, Louis XVI., and his radiant Queen passed beneath the elaborately wrought escutcheon surmounting the Porte de Paris, expressly forged by a blacksmith of Reims in honour of the occasion,[216] and received from the hands of the Lieutenant des Habitans the three silver keys of the city.[217] The King was crowned on the 11th June by the Cardinal Archbishop of Reims, Charles Antoine de la Roche Aymon, a prelate who had previously baptised, confirmed, and married him, when the six lay peers were represented by Monsieur (the Count of Provence), the Count d'Artois, the Dukes of Orleans, Chartres, and Bourbon, and the Prince de Condé. The royal train was borne by the Prince de Lambesq; the Marshal de Clermont Tonnerre officiated as Constable; and the sceptre, crown, and hand of justice were carried respectively by the Marshals de Contades, de Broglie, and de Nicolai.[218] How the ill-fated King exclaimed, as the crown of Charlemagne was placed upon his brow, 'It hurts me,' even as Henri III. had cried, under the same circumstances, 'It pricks me,' and how his natural benevolence led him to slur over that portion of the coronation oath in which he ought to have bound himself to exterminate all heretics, are matters of history. An innovation to be noted is, that at the banquet at the archiepiscopal palace, after the ceremony, the youthful sovereign did _not_ sit alone in solitary state beneath a canopy of purple velvet, ornamented with golden fleurs de lis, with his table encumbered by the great gold _nef_, the crown and the sceptres, the Constable, sword in hand, close by him, and the Grand Echanson and Ecuyer Tranchant tasting his wine and cutting his food,[219] circumstances under which 'the roast must be without savour and the Ai without bouquet.'[220] The King on this occasion admitted his brothers to his board; and the ecclesiastical peers, the lay peers, the ambassadors, and the great officers of the crown formed, as usual, four groups at the remaining tables, whilst the Queen and her ladies witnessed the gustatory exploits from a gallery. [Illustration: LOUIS XVI. TAKING THE CORONATION OATH AT REIMS (From a painting by Moreau).] The frightful oppression of _tailles_, _aides_, _corvées_, _gabelles_, and other dues that crushed the hapless peasant in the pre-Revolutionary era, weighed with especial severity upon the _vigneron_. In virtue of the _droit de gros_, the officers could at any hour make an inventory of his wine, decree how much he might consume himself, and tax him for the remainder.[221] The _fermiers généraux_, who farmed the taxes of the province, became his sleeping partners, and had their share in his crop.[222] In a vineyard at Epernay, upon four pieces of wine, the average produce of an arpent, and valued at 600 francs, the _ferme_ levied first 30 francs, and then when the pieces were sold 75 francs more.[223] The ecclesiastical tithe was also a heavy burden, at Hautvillers the eleventh of the wine being taken as _dismes_, at Dizy the twelfth, and at Pierry the twentieth.[224] The result was one continuous struggle of trickery on the part of the grower, and cunning on that of the officers.[225] The visits of the latter were paid almost daily, and their registers recorded every drop of wine in the cellars of the inhabitants.[226] [Illustration] But the wine had by no means acquitted all its dues. The merchant buying it had to pay another 75 francs to the _ferme_ before despatching it to the consumer. When he did despatch it, the _ferme_ strictly prescribed the route it was to take, any deviation from this being punished by confiscation; and it had to pay at almost every step. Transport by water was excessively onerous from constantly recurring tolls, and by land whole days were lost in undergoing examinations and verifications and making payments.[227] The commissionnaire charged with the conveyance of Bertin du Rocheret's wine to Calais from Epernay had from 70 to 75 francs per poinçon. Despite all these drawbacks, the export trade must have been considerable, for we are told that prior to the Revolution the profits on supplying two or three abbeys of Flanders were sufficient to enable a wine-merchant of Reims to live in good style.[228] On arriving at the town where it was to be drunk, the wine was subject to a fresh series of charges--_octroi_, _droit de détail_, _le billot_, _le cinquième en sus l'impôt_, _jaugeage_, _courtage_, _gourmettage_, &c.--frequently ranging up to 60 or 70 francs.[229] All this really affected the grower; for if the retail consumer, inhibited by high prices, could not buy, the former was unable to sell. At this epoch vine-grower and pauper were synonymous terms.[230] In certain districts of the Champagne the inhabitants actually threw their wine into the river to avoid paying the duties, and the Provincial Assembly declared that 'in the greater part of the province the slightest increase in duty would cause all the husbandmen to abandon the soil.'[231] It is scarcely to be wondered at that under such a system of excessive taxation the _fermiers généraux_, who all made good bargains with the State, should have amassed immense fortunes, whilst denying themselves no kind of luxury and enjoyment. They built themselves princely hotels, rivalled the nobility and even the Court in the splendour of their entertainments, grasped at money for the sensual gratification it would purchase, and loved pleasure for its own sake, and women for their beauty and _complaisance_. The _fermiers généraux_ of the province of Champagne had their bureaux, known as the Hôtel des Fermes, at Reims, and, after the town-hall, this was the handsomest civil edifice in the city. Erected in 1756 from designs by Legendre, it occupies to-day the principal side of the Place Royale. On the pediment of the façade is a bas-relief of Mercury, the god of commerce, in company with Penelope and the youthful Pan, surrounding whom are children engaged with the vintage and with bales of wool, typical of the staple trades of the capital of the Champagne. [Illustration: BAS-RELIEF ON THE ANCIENT HÔTEL DES FERMES AT REIMS.] [Illustration: L'ACCORD FRATERNEL (From a print published at the commencement of the Revolution).] The revolutionary epoch presents a wide gap in the written history of sparkling Champagne which no one seems to have taken the trouble of filling, though this hiatus can be to some extent bridged over by a glance at the caricatures of the period. It is evident from these that Champagne continued to be the fashionable wine _par excellence_. We can comprehend it was _de rigueur_ to 'fouetter le Champagne'[232] at the epicurean repasts held at the _petits maisons_ of the rich _fermiers généraux_, and that the _talons rouges_ of the Court of Louis Seize were not averse to the payment of 3 livres 10 sols for a bottle of this delightful beverage[233] when regaling some fair _émule_ of Sophie Arnould or Mademoiselle Guimard in the _coulisses_. One evening Mademoiselle Laguerre appeared on the stage as Iphigenia unmistakably intoxicated. 'Ah,' interjected the lively Sophie, 'this is not Iphigenia in Tauris, but Iphigenia in Champagne.' A proof of the aristocratic status of the wine is furnished by a print entitled _L'Accord Fraternel_, published at the very outset of the revolutionary movement, when it was fondly hoped that the Three Orders of the States General would unite in bringing about a harmonious solution to the evils by which France was sorely beset. In this the burly well-fed representative of the clergy holds out a bumper of Burgundy; the peasant--not one of the lean scraggy labourers, with neither shirt nor sabots,[234] prowling about half naked and hunger-stricken in quest of roots and nettle-tops, but a regular stage peasant in white stockings and pumps--grips a tumbler well filled with _vin du pays_; while the nobleman, elaborately arrayed in full military costume, with sword, cockade, and tie-wig all complete, delicately poises between his finger and thumb a tall _flute_ charged with sparkling Champagne. Moreover, we can plainly trace the exhilarating influence of the wine upon the 'feather-headed young ensigns' at the memorable banquet given to the officers of the Régiment de Flandre by the Gardes du Corps at Versailles, on the 2d Oct. 1789.[235] [Illustration: MIRABEAU TONNEAU (From a sketch by Camille Desmoulins).] Conspicuous amongst the titled topers of this period was the Viscount de Mirabeau--the younger brother of the celebrated orator and a fervent Royalist--nicknamed Mirabeau Tonneau, or Barrel Mirabeau, 'on account of his rotundity, and the quantity of strong liquor he contains.'[236] In a caricature dated 'An 1^{er} de la liberté,' and ascribed to Camille Desmoulins,[237] with whom the viscount long waged a paper war, his physical and bibacious attributes are very happily hit off. His body is a barrel; his arms, pitchers; his thighs, rundlets; and his legs inverted Champagne flasks; whilst in his left hand he holds a foam-crowned _flute_, and in his right another of those flasks, two of which he was credited with emptying at each repast.[238] [Illustration: LE NOUVEAU PRESSOIR DU CLERGÉ, 1789 (From a caricature of the epoch).] We have seen that the origin of many of the most famous _crûs_ of France was due to monkish labours, and that at Reims, as elsewhere, a large proportion of the ecclesiastical revenue was derived, either directly or indirectly, from the vineyards of the district. This was happily hit off in _Le Nouveau Pressoir du Clergé_, or _New Wine-Press for the Clergy_, published in 1789. A man of the people and a representative of the Third Estate, the latter in the famous slouched hat and short cloak, are working the levers of a press, under the influence of which a full-faced abbé is rapidly disgorging a shower of gold. A yet more portly ecclesiastic, worthy to be the Archbishop of Reims himself, is being led forward, in fear and trembling, to undergo a like operation; whilst in the background a couple of his compeers, reduced to the leanness of church-rats, are making off with gesticulations of despair. [Illustration: HENRI QUATRE AND LOUIS SEIZE. 'Ventre St. Gris! Is this my grandson Louis?' (Facsimile of a woodcut of the time.)] The chief personal traits of Louis Seize, as depicted in numerous contemporary memoirs, seem to have been a passion for making locks and a gross and inordinate appetite. High feeding usually implies deep drinking, and one may suppose that a wine so highly esteemed at Court as Champagne was not neglected by the royal gourmand. Still there seems to have been nothing in the unfortunate monarch's career to justify the cruel caricature wherein he is shown with the ears and hoofs of a swine wallowing in a wine-vat, with bottles, flasks, pitchers, cups, goblets, glasses, and _flûtes_ of every variety scattered around him; whilst Henri Quatre, who has just crossed the Styx on a visit to earth, exclaims in amazement, 'Ventre St. Gris! is this my grandson Louis?' In another caricature, entitled 'Le Gourmand,' and said to represent an incident in the flight of the royal family from Paris, Louis XVI. is shown seated at table--surrounded by stringed flasks of Champagne, with the customary tall glasses--engaged in devouring a plump capon. His Majesty is evidently annoyed at being interrupted in the middle of his repast, but it is difficult to divine who the intruder is intended for. He can scarcely be one of the commissioners despatched by the National Assembly to secure the king's return to Paris, as the German hussars drawn up in the doorway are inconsistent with this supposition. The female figure before the looking-glass is of course intended for Marie Antoinette, whilst the ungainly young cub in the background is meant for the Dauphin in an evident tantrum with his nurse.[239] As to the pamphleteers, who advocated the Rights of Man and aspersed Marie Antoinette; the poets, who addressed their countless airy trifles to Phyllis and Chloe; the penniless disciples of Boucher and Greuze; and the incipient demagogues, briefless advocates, unbeneficed abbés, discontented bourgeois, whose eloquence was to shatter the throne of the Bourbons, they were fain for the time being to content themselves with the _petit bleu_ of Argenteuil or Suresnes, consumed in company with Manon or Margot, in one of the dingy smoky _cabarets_ which the _café_ was so soon in a great measure to replace. When, however, their day did come, we may be sure they denied themselves no luxury, and sparkling Champagne would certainly have graced Danton's luxurious repasts, and may possibly have played its part at the last repast of the condemned Girondins. In '93, we find Champagne of 1779--the still wine, of course--announced for sale at Lemoine's shop in the Palais Royal; while a delectable compound, styled _crême de fleur d'orange grillée au vin de Champagne_, was obtainable at Théron's in the Rue St. Martin.[240] The sparkling wine can scarcely have failed to figure on the _carte_ of the sumptuous repasts furnished by the _restaurateurs_, Méot and Beauvillers, to the _de facto_ rulers of France,[241] although in 1795 the price of wine generally in Paris had increased tenfold.[242] Ex-_procureurs_ of the defunct Parliament carefully hoarded all that remained of the Champagne formerly lavished upon them by their ex-clients;[243] whilst the latter had to content themselves with tea at London and beer at Coblenz.[244] [Illustration] Although details respecting the progress of the Champagne wine-trade at home and abroad at the outset of the present century are somewhat scanty, we readily gather that the great popularity of the sparkling wine throughout Europe dates from an event which, at the time of its occurrence, the short-sighted Champenois looked upon as most disastrous. This was the Allied invasion of 1814-15. Consumption, so far as the foreign market was concerned, had been grievously interrupted by the great upset in all commercial matters consequent upon the wars of the Revolution and the Empire. It appears that the white wines of Champagne were sent to Paris, Normandy, Italy, and, 'when circumstances permitted of it,' to England, Holland, Sweden, Denmark, Russia, Spain, Portugal, and 'beyond the seas.' But the trade had suffered greatly during the wars with Austria and Russia in 1806 and 1807; and in the following years the consumption of white wine had fallen considerably, and a large number of wine-merchants had found themselves unable to meet their engagements.[245] The wine which Napoleon I. preferred is said to have been Chambertin; still, his intimacy with the Moëts of Epernay could scarcely fail to have led to a supply of the best sparkling Champagne from the cellars he had deigned to visit in person. His satraps, who travelled with the retinue of sovereign princes, included the wine in their equipment wherever they went, and the popping of its mimic artillery echoed in their tents the thunder of their victorious cannon. But comparatively few foreign guests met at their tables; and as their foes had on their side few victories to celebrate in a similar style, the knowledge of sparkling Champagne outside France was confined to the comparatively small number of persons of wealth and position able to pay an extravagant price for it. At length the fatal year, 1814, arrived, and the Allies swarmed across the frontier after the 'nations' fight' at Leipzig. The Champagne lying directly on the way to Paris saw some hard fighting and pitiless plundering. The Prussians of Baron von Tromberg got most consumedly drunk at Epernay. The Cossacks ravaged Rilly, Taissy, and the other villages of the Mountain; and not being able to carry off all the wine they found at Sillery, 'added to their atrocities,' in the words of an anonymous local chronicler,[246] by staving in the barrels and flooding the cellars. The Russians, under the renegade St. Priest, seized on Reims, whetted their thirst with salt herrings till the retail price of these dainties rose from 5 liards a pair to 3 sous apiece, and then set to work to quench it with Champagne to such an extent that when Napoleon suddenly swooped down upon the city like his own emblematic eagle, a large number of them, especially among the officers, were neither in a condition to fight nor fly.[247] The immense body of foreign troops who remained quartered in the east of France after the downfall of the Empire continued to pay unabated devotion to the _dive bouteille_. Tradition has especially distinguished the Russians, and relates how the Cossacks used to pour Champagne into buckets, and share it with their horses. But the walking sand-beds of North Germany, the swag-bellied warriors of Baden and Bavaria, and the stanch topers of Saxony and Swabia must of a surety have distinguished themselves. The votaries of Gambrinus, the beer king, strove whether they could empty as many bottles of Champagne at a sitting as they could flagons filled with the amber-hued beverage of their native province; while the inhabitants of those districts where the grape ripens sought to institute exhaustive comparisons between the vintages they gathered at home and the growths of the favoured region in which they now found themselves. [Illustration: LES RUSSES À PARIS (From a coloured print of the time).] The Berliner was fain to acknowledge the superiority of the foam engendered by Champagne over that crowning his favourite _weissbier_, his own beloved _kuhle blonde_, and the beer-topers of Munich and Dresden to give the preference to the exhilaration produced by quaffing the wine of Reims and Epernay over that due to the consumption of _bockbier_. The Nassauer and the Rhinelander had to admit certain intrinsic merits in the vintages produced on the slopes of the Marne, and found to be lacking in those grown on the banks of the Rhine, the Ahr, the Main, and the Moselle. The Austrian recognised the superiority of the wines of the Mountain over those of Voslau or the Luttenberg; and the Magyar had to allow that the _crûs_ of the River possessed a special charm which Nature had denied to his imperial Tokay. Even the red-coated officers who followed 'Milord Vilainton' to the great review at Mont Aimé, near Epernay, proved faithless to that palladium of the British mess-table, their beloved 'black strop.' Claret might in their eyes be only fit for boys and Frenchmen, and Port the sole drink for men; but they were forced to hail Champagne as being, as old Baudius had already phrased it, 'a wine for gods.' [Illustration: LE DÎNER DE MILORD GOGO, 1816 (After a coloured print of the time).] The officers of the Allied armies quartered in Paris after the Hundred Days supplemented the charms of the Palais Royal--then in the very apogee of its vogue as the true centre of Parisian life, with its cafés, restaurants, theatres, gambling-houses, and Galeries de Bois--with an abundance of sparkling Champagne. Royalty itself set the example by indicating a marked preference for the wine, Louis Dixhuit, according to a statement made by Wellington to Rogers, drinking nothing else at dinner. To celebrate the victories of Leipsic and Waterloo or a successful assault on the bank at Frascati's, to console for the loss of a _grosse mise_ at No. 113 or of a comrade transfixed beneath a lamp in the Rue Montpensier by a Bonapartist sword-blade, to win the smiles of some fickle Aspasia of the Palais Royal Camp des Tartares or to blot out the recollection of her infidelity, to wash down one of the Homeric repasts in which the English prototypes of the 'Fudge Family Abroad' indulged, the wine was indispensable; until, as a modern writer has put it, 'Waterloo was avenged at last by the _gros bataillons_ of the bankers at _roulette_ and _trente et quarante_, and by the sale to the invaders of many thousand bottles of rubbishing Champagne at twelve francs the flask.'[248] The rancorous enmity prevailing between the officers of Bonapartist proclivities placed on half-pay and the returned _émigrés_ who had accepted commissions from Louis XVIII., resulted, as is well known, in numerous hostile meetings. Captain Gronow has dwelt upon the bellicose exploits of a gigantic Irish officer in the _gardes du corps_, named Warren, who, when 'excited by Champagne and brandy,'[249] was prepared to defy an army; and he tells us that at Tortoni's there was a room set apart for such quarrelsome gentlemen, where, after these meetings, they indulged in riotous Champagne breakfasts.[250] At home, the British Government were being twitted on their parsimony in limiting the supply of Champagne for the table of the exiled Emperor at St. Helena to a single bottle per diem, a circumstance which led Sir Walter Scott to protest against the conduct of Lord Bathurst and Sir Hudson Lowe in denying the captive 'even the solace of intoxication.' As is not unfrequently the case, out of evil came good. The assembled nations had drunk of a charmed fountain, and it had excited a thirst which could not be quenched. The Russians had become acquainted with Champagne, which Talleyrand had styled '_le vin civilisateur par excellence_,' and to love this wine was with them a very decided step towards a liberal education. Millions of bottles, specially fortified to the pitch of strength and sweetness suited for a hyperborean climate, were annually despatched to the great northern empire from the house of Clicquot; and later on the travellers of rival firms, eager to secure a portion of this patronage, traversed the dominions of the autocrat throughout their length and breadth, and poured their wines in wanton profusion down the throats of one and all of those from whom there appeared a prospect of securing custom. [Illustration] From this influx of sparkling wine into the frozen empire of the Czar the acceptance of civilisation--of rather a superficial character, it is true--may be said to date. Had Peter the Great only preferred Champagne to corn-brandy, the country would have been Europeanised long ago. As it is, the wine has to-day become a recognised necessity in higher class Russian society, and scandal even asserts that whenever it is given at a dinner-party, the host is careful to throw the windows open, in order that the popping of the corks may announce the fact to his neighbours. Abroad the Russians are more reserved in their manners; and though ranking amongst the best customers of the Parisian _restaurateurs_ for high-class wines, it is only now and then that some excited Calmuck is to be seen flooding the glasses of his companions with Champagne in a public dining-room. The Russians, it should be noted, have sought, and not unsuccessfully, to produce sparkling wines of their own, more especially in the country of the Don Cossacks and near the Axis. [Illustration] Béranger might exclaim, with a poet's license, that he preferred a Turkish invasion to seeing the wines of the Champagne profaned by the descendants of the Alemanni;[251] but the merchants of Reims and Epernay were of a different opinion. _Les militaires_ have always affected Champagne; and a military aristocracy like that of the Fatherland, in the cruel days when peace forbade any more free quarters and requisitions, became as large purchasers of the wine as their somewhat scanty revenues allowed of. Their example was followed to a considerable extent by the self-made members of that plutocratic class which modern speculation has caused to spring into life in Germany. Advantage was speedily taken of this taste by their own countrymen, who aimed at supplanting Champagne by sparkling wines grown on native slopes. Nay more, the Germans, as a military nation, felt bound to carry the war into the enemy's territory, and hence it is that many important houses at Reims and Epernay are of German origin. Across the Rhine patriotism has had to yield to popularity, and the stanchest native topers have been forced to acknowledge, after due comparison in smoky _wein stuben_ and gloomy _keller_, that, though the sparkling wines of the Rhine and the Moselle are in their own way most excellent, there is but one _Champagner-wein_, with Reims for its Mecca and Epernay for its Medina. [Illustration] Of England we shall elsewhere speak at length; but the speculative trade of her colonies, with its sharp bargains, dead smashes, and large profits could hardly be carried on without the wheels of the car of Commerce and the tongues of her votaries being oiled with Champagne. The Swiss have only proved the truth of the proverb that imitation is the sincerest form of flattery by producing tolerable replicas of Champagne at Neufchâtel, Vevay, and Sion. Northern, or, to speak by the map, Scandinavian, Europe takes its fair share of the genuine article; and although the economic Belgian is apt to accept sparkling Saumur and Vouvray as a substitute, both he and his neighbour, the Dutchman, can to the full appreciate the superiority of the produce of the Marne over that of the Loire. The Italian and the Spaniard may affect to outwardly despise a liquor which they profess not to be able to recognise as wine at all; but the former has to allow, _per Bacco_, that it excels in its particular way his extolled Lacryma Christi, while the latter does not carry his proverbial sobriety so far as to exclude the wine from repasts in the upper circles of Peninsular society. Moreover, of recent years they have both commenced making sparkling wines of their own. The Austrian also produces sparkling wines from native vintages, notably at Voslau, Graz, and Marburg; still this has not in any way lessened his admiration for, or his consumption of, Champagne. The Greek is ready enough to 'dash down yon cup of Samian wine,' provided there be a goblet of Champagne close at hand to replace it with; and boyards and magnates of the debateable ground of Eastern Europe not only imbibe the sparkling wines of the Marne ostentatiously and approvingly, but several of them have essayed the manufacture of _vin mousseux_ on their own estates. The East, the early home of the vine, and the first region to impart civilisation, is perhaps the last to receive its reflux in the shape of sparkling wine. But, the prohibition of the Prophet notwithstanding, Champagne is to be purchased on the banks of the Golden Horn, and has been imported extensively into Egypt in company with _opéra-bouffe_, French _figurantes_, stock-jobbing, and sundry other matters of foreign extraction under the _régime_ of the late Khedive. The land of Iran has beheld with wonderment its sovereign freely quaffing the fizzing beverage of the Franks in place of the wine of Shiraz. The East Indies consume Champagne in abundance; for it figures not only on the proverbially hospitable tables of the merchants and officials of Calcutta, Bombay, and Madras, but at the symposia of most of the rajahs, princes, nawabs, and other native rulers. The almond-eyed inhabitant of 'far Cathay,' reluctant to abandon that strange civilisation so diametrically opposed in all its details to our own, continues to drink his native vintages, warm and out of porcelain cups, and to regard the sparkling drink of the Fanquis as a veritable 'devils' elixir.' But his utterly differing neighbour, the Japanese, so eager to welcome everything European, has gladly greeted the advent of Champagne, and freely yielded to its fascination. Turning to the undiscovered continent, we find sable sovereigns ruling at the mouths of the unexplored rivers of Equatorial Africa fully acquainted with Champagne, though disposed, from the native coarseness of their taste, to rank it as inferior to rum; whilst the Arab, filled with wonderment at the marvels of European civilisation which meet his eye at Algiers, bears back with him to the _douar_, wrapped up in the folds of his burnous, a couple of bottles of the wondrous effervescing drink of the Feringhees as a testimony, even as Othere brought the walrus-tooth to Alfred. One enthusiastic Algerian colonist has gone so far as to prophesy the advent of the day when the products of the native vineyards shall eclipse Champagne.[252] Let us hope, however, in the interest of Algerian digestions, that this day is as yet far distant. [Illustration] With respect to the consumption of Champagne in the Western world, the United States' exceeds that of any European country, England and France alone excepted, despite the competition of sparkling Catawba and of a certain diabolical imitation, the raw material of which, it is asserted, is furnished not by the grapes of the Carolinas, the peaches of New Jersey, or the apples of Vermont, but by the oil-wells of Pennsylvania--in fact, petroleum Champagne. The _cabinet particulier_ seems to be an institution as firmly established in the leading cities of the States as in Paris; and rumour says that drinking from a Champagne-glass touched by a fair one's lips has replaced the New England pastime of eating the same piece of maple-candy till mouths meet. As regards the South American Republics, the popping of musketry at each fresh _pronunciamento_ is certain to be succeeded by that of Champagne-corks in honour of the success of one or the other of the contending parties. In Europe Champagne has continued to be, from the days of Paulmier and Venner downwards, the drink of kings, princes, and great lords as they described it. Take a list of the potentates of the present century, and the majority of them will be found to have evinced at some time or other a partiality for the wine. Louis XVIII. drank nothing else at table. The late ruler of Prussia, Frederick William IV., had such a penchant for Champagne of a particular manufacture, that he obtained the cognomen of King Clicquot. The predecessor of Pio Nono, Gregory XVI., rivalled him in this appreciation, and, terrible to relate, so did the Commander of the Faithful, Abdul Medjid. The latter might, however, have pleaded the excuse put forward by Abd-el-Kader, that although the Prophet had forbidden wine, yet Champagne came into the category of aerated waters, concerning which he had said nothing, a remark justifying the title given to this wit-inspiring beverage of being 'the father of _bons mots_.' Prince Bismarck, in the stormy period of his youth, was in the barbarous habit of imbibing Champagne mixed with porter; but at present he judiciously alternates it with old Port. Marshal MacMahon and the King of the Belgians are said to drink the pink variety of the _vin mousseux_ by preference. [Illustration: 'SOUS LA TONNELLE' (From a print of the time of the Restoration).] [Illustration] [Illustration] [Illustration] [Illustration: 'AU BEAU SEXE!'] Naturally, in France as elsewhere, the sparkling vintage of the Marne maintains its claims to be reckoned the wine of beauty and fashion, and more especially in beauty's gayer hours. A glass of Champagne and a _biscuit de Reims_ has been a refection which, though often verbally declined, was in the end pretty sure to be accepted from the days of the _merveilleuses_ and _incroyables_, through those of the _lionnes_, down to the present epoch of the _cocodettes de la haute gomme_. Neither at ceremonial banquets nor at ordinary dinner-parties among our neighbours does Champagne hold, however, so prominent a place as amongst ourselves, owing to the great variety of other wines--all capable of appreciation by trained palates--entering into the composition of these festive repasts. In fact, a _repas de noces_ is the only occasion on which Champagne flows in France with anything like the freedom to which we are accustomed; and then it is that its exhilarating effect is marked, as some portly old boy rises with twinkling eye to propose the health of the bride, or of that _beau sexe_ to which he feels bound to profess himself deeply devoted. At such open-air gatherings as the races at Longchamps and Chantilly, the _buffet_ will be besieged by a succession of frail fair ones in the most elaborate _toilettes de courses_, seeking to nerve themselves to witness a coming struggle, or to console themselves for the defeat of the horse backed by their favoured admirer. And, when writing of this wine, it is altogether impossible to omit a reference to those _tête-à-tête_ repasts _en cabinet particulier_, of which it is the indispensable adjunct. Its mollifying influence on the feminine heart on occasions such as these has been happily hit off by Charles Monselet in his _Polichinelle au Restaurant_: [Illustration] '/Polichinelle au Restaurant./ I. In a cabinet of Vachette, Pomponnette Listens to the pressing lover; Who, before they've done their soup, Cock-a-hoop, Dares his passion to discover. II. Elbows resting on the cloth, Partly wrath-- So much do his words astound-- Resolute she to resist Being kissed, Draws her mantle closer round. III. Whilst in vain his cause he pressed, A third guest, Who in ice-pail by them slumbered, Rears above his wat'ry bed Silver head And long neck with ice encumbered. IV. 'Tis Champagne, who murmurs low, "Don't you know That when once you set me flowing, This fair rebel to Love's dart In her heart Soon will find soft passion glowing? V. This, if you will list to me, You shall see; Cease to swear by flames and fire, Cast aside each angry thought, As you ought, And at once cut through my wire, VI. For I am the King Champagne, And I reign Over e'en the sternest lasses, When midst maddening song and shout I gush out, Flooding goblets, bumpers, glasses. VII. As thus spoke the generous wine, Its benign Influence her heart 'gan soften. Who seeks such a cause to gain, To Champagne His success finds owing often.'[253] [Illustration] VI. /Champagne in England./ The strong and foaming wine of the Champagne forbidden his troops by Henry V.--The English carrying off wine when evacuating Reims on the approach of Jeanne Darc--A legend of the siege of Epernay--Henry VIII. and his vineyard at Ay--Louis XIV.'s present of Champagne to Charles II.--The courtiers of the Merry Monarch retain the taste for French wine acquired in exile--St. Evremond makes the Champagne flute the glass of fashion--Still Champagne quaffed by the beaux of the Mall and the rakes of the Mulberry Gardens--It inspires the poets and dramatists of the Restoration--Is drank by James II. and William III.--The advent of sparkling Champagne in England--Farquhar's _Love and a Bottle_--Mockmode the Country Squire and the witty liquor--Champagne the source of wit--Port-wine and war combine against it, but it helps Marlborough's downfall--Coffin's poetical invitation to the English on the return of peace--A fraternity of chemical operators who draw Champagne from an apple--The influence of Champagne in the Augustan age of English literature--Extolled by Gay and Prior--Shenstone's verses at an inn--Renders Vanbrugh's comedies lighter than his edifices--Swift preaches temperance in Champagne to Bolingbroke--Champagne the most fashionable wine of the eighteenth century--Bertin du Rocheret sends it in cask and bottle to the King's wine-merchant--Champagne at Vauxhall in Horace Walpole's day--Old Q. gets Champagne from M. de Puissieux--Lady Mary's Champagne and chicken--Champagne plays its part at masquerades and bacchanalian suppers--Becomes the beverage of the ultra-fashionables above and below stairs--Figures in the comedies of Foote, Garrick, Coleman, and Holcroft--Champagne and real pain--Sir Edward Barry's learned remarks on Champagne--Pitt and Dundas drunk on Jenkinson's Champagne--Fox and the Champagne from Brooks's--Champagne smuggled from Jersey--Grown in England--Experiences of a traveller in the Champagne trade in England at the close of the century--Sillery the favourite wine--Nelson and the 'fair Emma' under the influence of Champagne--The Prince Regent's partiality for Champagne punch--Brummell's Champagne blacking--The Duke of Clarence overcome by Champagne--Curran and Canning on the wine--Henderson's praise of Sillery--Tom Moore's summer fête inspired by Pink Champagne--Scott's Muse dips her wing in Champagne--Byron's sparkling metaphors--A joint-stock poem in praise of Pink Champagne--The wheels of social life in England oiled by Champagne--It flows at public banquets and inaugurations--Plays its part in the City, on the Turf, and in the theatrical world--Imparts a charm to the dinners of Belgravia and the suppers of Bohemia--Champagne the ladies' wine _par excellence_--Its influence as a matrimonial agent--'O the wildfire wine of France!' [Illustration] So great a favourite as Champagne now is with all classes in England, the earliest notice of it in connection with our history nevertheless represents it in a somewhat inimical light. For, according to an Italian writer of the fifteenth century, 'the strong and foaming wine of Champagne was found so injurious that Henry V. was obliged, after the battle of Agincourt, to forbid its use in his army, excepting when tempered with water.'[254] Although this may be the earliest mention of the wine of the Champagne by name in association with our own countrymen, opportunities had been previously afforded to them of becoming acquainted with its assumed objectionable qualities. The prelates who crossed 'the streak of silver sea' with Thurstan of York to attend the ecclesiastical councils held at 'little Rome,' as Reims was styled in the twelfth century, and the knights and nobles who swelled the train of Henry II. when he did homage to Philip Augustus at the latter's coronation, may be regarded as exceptionally fortunate, or unfortunate, in this respect, since the bulk of the English wine-drinkers of that day had to content themselves with the annual shipments of Anjou and Poitevin wines from Nantes and La Rochelle.[255] But the stout men-at-arms and death-dealing archers who followed the third Edward to the gates of Reims in the days when ''Twas merry, 'twas merry in France to go, A yeoman stout with a bended bow, To venge the King on his mortal foe, And to quaff the Gascon wine,' no doubt found consolation for some of the hardships they endured during their wet and weary watches in the bitter winter of 1365 in the familiarity they acquired with the vintages of the Mountain and the Marne. [Illustration] And, their sovereign's prohibition notwithstanding, there is every reason to believe that the heroes of Agincourt drank pottle-deep of the forbidden beverage. The grim Earl of Salisbury bore no love to the burghers of Reims;[256] but there is little likelihood that his aversion extended to the wine of the province he ruled as governor, and the garrisons of its various strongholds over which the red cross of St. George triumphantly floated revelled on the best of 'the white wyne and the rede.' In the days of hot fighting and keen foraging which marked the close of Bedford's regency, there is ample evidence to show that our countrymen had acquired and retained a very decided taste for these growths. When Charles VII. entered Reims in triumph, with Jeanne Darc by his side and the chivalry of France around him, the retreating English garrison bore forth with them on the opposite side of the city a string of wains piled high with casks of wine, the pillage of the burghers' cellars.[257] Tradition tells, too, how the English, besieged in the town of Epernay, had gathered there great store of wine, and how this suggested to their captain a cunning stratagem. Having caused a number of wagons to be laden with casks of wine, he despatched them with a feeble escort through the gate furthest from the beleaguering forces, as though destined to Chalons as a place of safety. The French commander marked this, and as soon as the convoy was well clear of the walls, a body of horse came spurring after it in hot haste. The wagon-train halted; there was a brief attempt to turn the laden vehicles homewards, and then, seeing the hopelessness of this, the escort galloped back into the town, and down swooped the Frenchmen on their prize. The ride had been sharp; the day was hot, and the road dusty. So a score of the captured casks were quickly broached; and as the generous fluid flowed freely down the throats of the captors, it soon began to produce an effect. Some of them, overcome by the heat and the wine, loosened their armour, and stretched themselves at length on the ground; whilst others, grouped around some fast emptying barrel, continued to quaff from their helmets and other improvised drinking vessels confusion to the 'island bull-dogs.' When lo, the gate of the town flew open; an English trumpet rang out its note of defiance; and, with lances levelled, the flower of the garrison poured forth like a living avalanche upon the startled Frenchmen. Before they could make ready to fight or fly, the foe was upon them, and their blood was soon mingling on the dusty highway with the pools of wine which had gushed forth from the abandoned casks. Hardly one escaped the slaughter; but local tradition chuckles grimly as it notes that in revenge thereof every man of the garrison was put to the edge of the sword on the subsequent capture of the town by the French.[258] [Illustration] At the close of the fruitless struggle against the growing power of Charles the Victorious, we were fain to fall back, as of old, upon the strong wines of south-western France, the vintages of Bergerac, Gaillac, and Rabestens, shipped to us from the banks of the Garonne,[259] and the luscious malmseys of the Archipelago, to which were subsequently added the growths of southern Spain. The taste of the wine of the Champagne must have been almost forgotten amongst us when the growing fame of the vineyards of Ay attracted the notice of Bluff King Hal. Most likely he and Francis I. swore eternal good fellowship at the Field of the Cloth of Gold over a beaker of this regal liquor. Once alive to its merits, the King, whose ambassadors, _pace_ John Styles, seem to have had standing orders to keep an equally sharp look out for wines or wives likely to suit the royal fancy, neglected no opportunity of securing it in perfection. Like his contemporaries, Charles V., Francis I., and Leo X., he stationed a commissioner at Ay intrusted with the onerous duty of selecting a certain number of casks of the best growths, and despatching them, carefully sealed, to the cellars of Whitehall, Greenwich, and Richmond. The example set by the monarch was, however, too costly a one to be followed by his subjects, and the very name of Champagne probably remained unknown to them for years to come. The poets and dramatists of the Elizabethan era, who have left us so accurate a picture of the manners of their day, and make such frequent allusions to the wines in vogue, do not even mention Champagne; Gervase Markham preserves a like silence in his _Modern Housewife_,[260] while the passages in Surflet's _Maison Rustique_ extolling the wine of Ay are merely translations from the original French edition.[261] And though Venner speaks of these wines as excelling all others, he is careful to attribute their consumption to the King and the nobles of France.[262] The captive Queen of Scots, whose consumption of wine elicited dire lament from one of her lordly jailers,[263] may have missed at Fotheringay the vintage she had tasted in early life when enjoying the hospitality of her uncle, Cardinal Charles of Lorraine, at Reims; but to the half-hearted pedant, her son, the name of Epernay recalled no convivial associations--it was merely the title of a part of his slaughtered mother's appanage. Spanish influence and Spanish wine ruled supreme at his Court; and though Rhenish crowned the goblets of many of the high-souled cavaliers who rallied round King Charles and Henrietta Maria, the bulk of the English nation remained faithful, till the close of the Commonwealth, to their old favourites of the south of Spain and the fragrant produce of the Canaries. [Illustration] All this was altered when 'the King enjoyed his own again;' for the Restoration made Champagne--that is, the still red wine of the province--the most fashionable, if not the most popular, wine in England. At the Court of Louis XIV. the future Merry Monarch and his faithful followers had acquired a taste for the wines of France, and they brought back this taste,[264] together with sundry others of a far more reprehensible character, with them to England. One of the first and most acceptable gifts of Louis to his brother-sovereign on the latter's recall was 'two hundred hogsheads of excellent wine--Champagne, Burgundy, and Hermitage.'[265] Returning home more French than the French themselves, the late exiles ruminated on the flesh-pots of Egypt, and sighed; and we can readily picture a gallant who had seen hot service under Condé or Turenne exclaiming to his friend and fellow-soldier: 'Ah, Courtine, must we be always idle? Must we never see our glorious days again? When shall we be rolling in the lands of milk and honey, encamped in large luxuriant vineyards, where the loaded vines cluster about our tents, drink the rich juice just pressed from the plump grape?'[266] And that friend replying: 'Ah, Beaugard, those days have been; but now we must resolve to content ourselves at an humble rate. Methinks it is not unpleasant to consider how I have seen thee in a large pavilion drowning the heat of the day in Champagne wines--sparkling sweet as those charming beauties whose dear remembrance every glass recorded--with half a dozen honest fellows more.'[267] Demand created supply, until, in 1667, a few years after the Restoration, France furnished two-fifths of the amount of wine consumed in the kingdom;[268] and the taste of the royal sybarite for the light-coloured wines of the Marne seems to be hinted at in Malagene's exclamation: 'I have discovered a treasure of pale wine.... I assure you 'tis the same the King drinks of.'[269] St. Evremond, who, though not precisely cast by Nature from 'the mould of form,' fulfilled for many years the duties of arbiter elegantiarum at Charles's graceless Court, decidedly did his best to render the Champagne _flûte_ 'the glass of fashion.' Ever ready to speak in praise of the wines of Ay, Avenay, and Reims,[270] the mentor of the Count de Grammont strove by example as well as by precept to win converts to his creed. In verse he declares that the beauties of the country fail to console him for the absence of Champagne; regrets that the season of the wines of the Marne is over, and that the yield of those of the Mountain had failed; and shudders at the prospect of being obliged to have recourse to the Loire, to Bordeaux, or to Cahors for the wine he will have to drink.[271] [Illustration] The lively Frenchman found plenty of native writers to reëcho him. Champagne sparkles in all the plays of the Restoration, and seems the fitting inspiration of their matchless briskness of dialogue. The Millamours and Bellairs, the Carelesses and Rangers, the Sir Joskin Jolleys and Sir Fopling Flutters, the _beaux_ of the Mall and the rakes of the Mulberry and New Spring Gardens, the gay frequenters of the Folly on the Thames and the _habitués_ of Pontack's Ordinary, whom the contemporary dramatists transferred bodily to the stage of the King's or the Duke's, are constantly tossing off bumpers of it. Their lives would seem to have been one continuous round of love-making and Champagne-drinking, to judge from the following 'catch,' sung by four merry gentlemen at a period when, according to Redding, ten thousand tuns of French wine were annually pouring into England: 'The pleasures of love and the joys of good wine, To perfect our happiness, wisely we join; We to Beauty all day Give the sovereign sway, And her favourite nymphs devoutly obey. At the plays we are constantly making our court, And when they are ended we follow the sport To the Mall and the Park, Where we love till 'tis dark; Then sparkling Champaign[272] Puts an end to their reign; It quickly recovers Poor languishing lovers; Makes us frolic and gay, and drowns all our sorrow; But, alas, we relapse again on the morrow.'[273] [Illustration] We learn, indeed, that under the influence of 'powerful Champaign, as they call it, a spark can no more refrain running into love than a drunken country vicar can avoid disputing of religion when his patron's ale grows stronger than his reason.'[274] Probably it was owing to this quality of inspiring a tendency to amativeness that ladies were sometimes expected to join in such potations. 'She's no mistress of mine That drinks not her wine, Or frowns at my friends' drinking motions; If my heart thou wouldst gain, Drink thy flask of Champaign; 'Twill serve thee for paint and love-potions,'[275] is the sentiment enunciated in chorus by four half-fuddled topers in the New Spring Gardens. At the Mulberry Gardens we find that 'Jack Wildish sent for a dozen more Champaign, and a brace of such girls as we should have made honourable love to in any other place.'[276] With such manners and customs can we wonder at one gentleman complaining how another 'came where I was last night roaring drunk; swore--d--him!--he had been with my Lord Such-a-one, and had swallowed three quarts of Champaign for his share;'[277] or have any call to feel surprised that such boon companions should 'come, as the sparks do, to a playhouse too full of Champaign, venting very much noise and very little wit'?[278] Champagne remains ignored in such books as the _Mystery of Vintners_;[279] but although technical works may be silent, the poets vie with the dramatists in extolling its exhilarating effects--effects surely perceptible in the witty, careless, graceful verse with which the epoch abounds. John Oldham--who, after passing his early years as a schoolmaster, was lured into becoming, in the words of his biographer, 'at once a votary of Bacchus and Venus' by the patronage of Rochester, Dorset, and Sedley in 1681, and who realised the fable of the pot of brass and the pot of earthenware by dying from the effects of the company he kept two years later--has given a list of the wines in vogue in his day: 'Let wealthy merchants, when they dine, Run o'er their witty names of wine: Their chests of Florence and their Mont Alchine, Their Mants, Champaigns, Chablees, Frontiniacks tell; Their aums of Hock, of Backrag [Bacharach] and Mosell.'[280] He gives the wines of our 'sweet enemy' a high position, too, in his _Dithyrambick, spoken by a Drunkard_, who is made to exclaim, 'Were France the next, this round Bordeau shall swallow, Champaign, Langou [L'Anjou], and Burgundy shall follow.'[281] Butler makes the hero of his immortal satire prepared to follow the old Roman fashion with regard to his lady's name, and to 'Drink ev'ry letter on't in stum, And make it brisk Champaign become;'[282] and speaks of routed forces having 'Recovered many a desperate campaign With Bordeaux, Burgundy, and Champaign.'[283] And Sir Charles Sedley, in an apologue written towards the close of the century, tells how a doctor of his day was sorely troubled by the unreasonable lives led by his patients, until 'One day he called 'em all together, And, one by one, he asked 'em whether It were not better by good diet To keep the blood and humours quiet, With toast and ale to cool their brains Than nightly fire 'em with Champains.'[284] In 1679 the peculiar ideas of political economy then prevailing led to a formal prohibition of the importation of French wines, and the consequent substitution in their place of those of Portugal. One can imagine the consternation of the 'beaux' and 'sparks' at this fatal decree, and the satisfaction of the few vintners whose cellars chanced to be well stored with the forbidden vintages of France--with 'The Claret smooth, red as the lips we press In sparkling fancy while we drain the bowl; The mellow-tasted Burgundy, and, quick As is the wit it gives, the gay Champagne.'[285] But, Port wine and prohibitions notwithstanding, men of fashion of that epoch were not entirely obliged to abandon their favourite potations, since five thousand hogsheads of French wine were surreptitiously landed on the south-west coast of England in a single year.[286] Fortunately, too, for them, the Government came to the conclusion that it was for the time being futile to fight against popular tastes, and in 1685 the obnoxious prohibition was removed, with the result that, two years later, the imports of French wine were registered as fifteen thousand tuns--that is, sixty thousand hogsheads.[287] [Illustration] On the outbreak of hostilities with France in 1689, the import of French wines received a serious check, and as they vanished from the revenue returns, so Champagne began to disappear from the social board and the literature of the day. Strange to say, however, it was not only the favourite wine of William III., but of his dethroned father-in-law, James II. The red wines of the province of Champagne had always found a ready sale in Flanders and the Low Countries,[288] and quickened the minds of the stout seamen who fought against Blake and Rupert. The variety produced from the Beaune grape at Vertus was the one patronised by Macaulay's pet hero, the hook-nosed Dutchman,[289] whilst the exile of St. Germain seems to have been more catholic in his tastes.[290] Eagerly must the _gourmets_ of the day, when, 'if we did not love the French, we coveted their wines,'[291] have hailed the return of a peace which permitted them not only to indulge in their old favourites, but to welcome a new attraction in the shape of sparkling Champagne. The term 'sparkling' as applied to wine did not at the outset necessarily mean effervescing, as in one of Farquhar's comedies we find Roebuck comparing himself to 'a bumper of Claret, smiling and sparkling.'[292] Towards the close of the century, however, we meet with sure proof of the advent of the delectable beverage with which the worthy cellarer of Hautvillers was the first to endow droughty humanity. The contemporary dramatists were ever on the alert to shoot Folly as she flew. The stage was really the mirror of that time, and those who wrote for it seized on every passing whim, fashion, or fancy of the day. The introduction of a new wine was certainly not to be missed by them, and the recently discovered _vin mousseux_ of Dom Perignon is plainly referred to in Farquhar's aptly-named comedy, _Love and a Bottle_, produced in 1698, just after the Peace of Ryswick had allowed the reopening of trade with France. The second scene of act ii. represents the lodgings of Mockmode, the country squire, who aims at being 'a beau,' and who is discovered in close confabulation with his landlady, the Widow Bullfinch: '_Mock._ But what's most modish for beverage now? For I suppose the fashion of that always alters with the clothes. _W. Bull._ The tailors are the best judges of that; but Champaign, I suppose. _Mock._ Is Champaign a tailor? Methinks it were a fitter name for a wig-maker. I think they call my wig a campaign. _W. Bull._ You're clear out, sir--clear out. Champaign is a fine liquor, which all great beaux drink to make 'em witty. _Mock._ Witty! O, by the universe, I must be witty! I'll drink nothing else; I never was witty in my life. Here, Club, bring us a bottle of what d'ye call it--the witty liquor.' The Widow having retired, Club, Mockmode's servant, reënters with a bottle and glasses. '_Mock._ Is that the witty liquor? Come, fill the glasses.... But where's the wit now, Club? Have you found it? _Club._ Egad, master, I think 'tis a very good jest. _Mock._ What? _Club._ Why, drinking. You'll find, master, that this same gentleman in the straw doublet, this same Will o' the Wisp, is a wit at the bottom. Here, here, master, how it puns and quibbles in the glass![293] _Mock._ By the universe, now I have it; the wit lies in the jingling! All wit consists most in jingling. Hear how the glasses rhyme to one another.... I fancy this same wine is all sold at Will's Coffee-house.' Here we have a palpable hit at the source of inspiration indulged in by many of the wits and rhymesters who gathered round 'glorious John Dryden' within the hallowed walls of that famous rendezvous. And likely enough, when they 'were all at supper, all in good humour, Champaign was the word, and wit flew about the room like a pack of losing cards.'[294] Farquhar seems, above all others, to have hailed the new wine with pleasure. We all remember the 'red Burgundy' which saves Mirabel from his perilous position in the cut-throats' den; but the flighty hero of the _Inconstant_ is equally enthusiastic over sparkling wine when he exclaims: 'Give me the plump Venetian, brisk and sanguine, that smiles upon me like the glowing sun, and meets my lips like sparkling wine, her person shining as the glass, and spirit like the foaming liquor.'[295] The benignant influence of the beverage is, moreover, referred to by Farquhar in his epilogue to the _Constant Couple_, where, in alluding to the critics, it is said that 'To coffee some retreat to save their pockets, Others, more generous, damn the play at Locket's; But there, I hope, the author's fears are vain, Malice ne'er spoke in generous Champain.'[296] Further, he makes Benjamin Wouldbe exclaim: 'Show me that proud stoick that can bear success and Champain; philosophy can support us in hard fortune, but who can have patience in prosperity?'[297] Farquhar shows his usual keen observation of the minutest features of the life of his day in his allusion to the flask--the pear-shaped _flacon_ in which Champagne made its _entrée_ into fashionable life.[298] Archer, in his ditty on 'trifles,' thus warbles: 'A flask of Champaign, people think it A trifle, or something as bad; But if you'll contrive how to drink it, You'll find it no trifle, egad!'[299] Congreve, in evident reference to the still wine, thus writes to Mr. Porter, husband of the celebrated actress, from Calais, August 11, 1700: 'Here is admirable Champaign for twelvepence a quart, as good Burgundy for fifteenpence; and yet I have virtue enough to resolve to leave this place to-morrow for St. Omers, where the same wine is half as dear again, and may be not quite so good.'[300] Champagne suffered like other French wines from the War of Succession and the Methuen Treaty, by which the Government strove to pour Port wine down the throats of the people. The poets and satirists, supported by Dean Aldrich, 'the Apostle of Bacchus;' the miserly Dr. Ratcliffe, who ascribed all diseases to the lack of French wines, and imputed the badness of the vintages he was wont to place upon his table to the difficulty he experienced in obtaining them; the jovial Portman Seymour; the rich 'smell-feast' Pereira and General Churchill, Marlborough's brother, together with a host of 'bottle companions,' lawyers, and physicians, united to fight against this attempt.[301] They would drink their old favourites, in spite of treaties, and would praise them as they deserved; and means were found to gratify their wishes. According to official returns, the nominal importation of French wines fell in 1701 to a trifle over two thousand tons; and though this quantity was only once exceeded up to 1786, the influence of a steady demand, a short sea-passage, an extensive coast-line, and a ridiculously inefficient preventive service in aid of the high duty need to be taken into consideration. The contraband traders of the beginning of the century smuggled French wine into England, just as they continued to do at a later period into Scotland and Ireland, when the taste for ardent spirits which sprang up in the Georgian era rendered the surreptitious import of 'Nantz' and 'Geneva' the more profitable transaction as regarded England. Farquhar throws light on one method pursued when Colonel Standard hands Alderman Smuggler his pocket-book, which he had dropped, with the remark: 'It contains an account of some secret practices in your merchandising, amongst the rest, the counterpart of an agreement with a correspondent at Bordeaux about transporting French wine in Spanish casks.'[302] That the Champenois were themselves aware of the appreciation in which their wine was held in England is shown by a passage in Coffin's _Campania vindicata_. Writing in 1712, the year before the ratification of the Treaty of Utrecht, he calls on the Britons in presence of returning peace to cross the seas, and instead of lavishing their wealth to pleasure blood-stained Mars, to fill their ships with the treasures of the Remois Bacchus, and bear home these precious spoils instead of fatal trophies.[303] Addison, referring to one source whence French wines were derived, remarks: 'There is in this City a certain fraternity of Chymical Operators who work underground, in holes, caverns, and dark retirements, to conceal their mysteries from the eyes and observation of mankind. These subterraneous Philosophers are daily employed in the Transmigration of Liquors, and, by the power of Magical Drugs and Incantations, raise under the streets of _London_ the choicest products of the hills and valleys of _France_. They can squeeze _Bourdeaux_ out of a _Sloe_, and draw _Champagne_ from an _Apple_.'[304] He tells us that 'the person who appeared against them was a Merchant, who had by him a great magazine of wines, that he had laid in before the war: but these Gentlemen (as he said) had so vitiated the nation's palate, that no man could believe his to be _French_, because it did not taste like what they sold for such.' For the defence it was urged that 'they were under a necessity of making Claret if they would keep open their doors, it being the nature of Mankind to love everything that is Prohibited.'[305] The enquiry, 'And where would your beaux have Champaign to toast their mistresses were it not for the merchant?'[306] is from a panegyrist of the more legitimate school of trade. Altogether it is tolerably certain that Champagne--genuine or fictitious, from grape or gooseberry--played a more important part in the conviviality of the early portion of the eighteenth century than might be supposed from the imports of the epoch, whilst there is little doubt but that it helped to inspire some of the finest productions of the Augustan age of English literature. Gay places it first amongst the wines offered to a party of guests entering a tavern, making the drawer exclaim: 'Name, sirs, the wine that most invites your taste, Champaign or Burgundy, or Florence pure, Or Hock antique, or Lisbon new or old, Bourdeaux, or neat French wine, or Alicant.'[307] This reference to Champagne most likely relates to the still wine; but it is probably the sparkling variety which is alluded to in the verses which Gay addressed to Pope on the completion of the _Iliad_ in 1720, and wherein he represents General Wilkinson thus apostrophising as the ship conveying the poet passes Greenwich: 'Come in, my friends, here shall ye dine and lie; And here shall breakfast and shall dine again, And sup and breakfast on (if ye comply), For I have still some dozens of Champaign.'[308] Witty Mat Prior, poet and diplomatist, was always ready to manifest his contempt for the heavy fluid with which the Methuen treaty deluged our island in place of the light fresh-tasting wines of France that had cheered and inspired his earlier sallies. Writing whilst in custody on a charge of treason between 1715 and 1717, and referring to the mind under the name of Alma, he tells us how 'By nerves about our palate placed, She likewise judges of the taste, Else (dismal thought!) our warlike men Might drink thick Port for fine Champagne.'[309] He likewise inculcates a lesson of philosophy, especially suited to his own situation at that moment, when he remarks of fortune: 'I know we must both fortunes try, And bear our evils, wet or dry. Yet, let the goddess smile or frown, Bread we shall eat, or white or brown; And in a cottage or a court Drink fine Champagne or muddled Port.'[310] There were many, no doubt, ready to emulate the hero of one of his minor pieces, and 'from this world to retreat As full of Champagne as an egg's full of meat.'[311] Shenstone gives expression to much the same sentiment as Prior when he found 'his warmest welcome at an inn,' and wrote on the window-pane at Henley: ''Tis here with boundless power I reign, And every health which I begin Converts dull Port to bright Champagne; Such freedom crowns it at an inn.'[312] [Illustration] Vanbrugh, whose writings were of a decidedly lighter character than the edifices he erected, probably had recourse to Champagne to assist him in the composition of the former, and neglected it when planning the designs for the latter. These, indeed, would seem to have been conceived under the influence of some such 'heavy muddy stuff' as the 'Norfolk nog,' which Lady Headpiece reproaches her husband for allowing their son and heir to indulge in, saying: 'Well, I wonder, Sir Francis, you will encourage that lad to swill such beastly lubberly liquor. If it were Burgundy or Champaign, something might be said for't; they'd perhaps give him some art and spirit.'[313] Swift has given in his _Journal to Stella_ extensive information as to the wines in vogue in London in 1710-13. He seems for his own part to have been, as far as nature permitted him, an accommodating toper, indulging, in addition to Champagne, in Tokay, Portugal, Florence, Burgundy, Hermitage, 'Irish wine,' _i.e._ Claret, 'right French wine,' Congreve's 'nasty white wine' that gave him the heartburn, and Sir William Read's 'admirable punch.' He acknowledges that the more fashionable beverages of the day were not to his taste. 'I love,' writes he, 'white Portugal wine better than Claret, Champaign, or Burgundy. I have a sad vulgar appetite.'[314] Still, while observing due moderation, he did not entirely shun the lighter potations with which the table of the luxurious and licentious St. John was so freely supplied. On one occasion he writes: 'I dined to-day by appointment with Lord Bolingbroke; but they fell to drinking so many Spanish healths in Champaign, that I stole away to the ladies and drank tea till eight.'[315] And on another we find him refusing to allow his host to 'drink one drop of Champaign or Burgundy without water.'[316] Our countrymen do not appear to have taken heed of the controversy regarding the respective merits of Champagne and Burgundy, but thankfully accepted the goods that the gods and the sunny soil of France provided them. The accusation, however, banded about by the partisans of these rival vintages, of their tendency to produce gout, had apparently been accepted as gospel truth over here in the first decade of the century. Thus the Dean notes that he 'dined with Mr. Secretary St. John, and staid till seven, but would not drink his Champaign and Burgundy, for fear of the gout.'[317] When suffering from a rheumatic pain he displays commendable caution at dinner with Mr. Domville, only drinking 'three or four glasses of Champaign by perfect teasing,'[318] for fear of aggravating his suffering. He is prompt, however, to acknowledge himself mistaken: 'I find myself disordered with a pain all round the small of my back, which I imputed to Champaign I had drunk, but find it to have been only my new cold.'[319] The Dean does not appear to have been the only sufferer, for we find him writing: 'I called this evening to see Mr. Secretary, who had been very ill with the gravel and pains in his back, by Burgundy and Champaign, added to the sitting up all night at business; I found him drinking tea, while the rest were at Champaign, and was very glad of it.'[320] Even Pope, the perforcedly abstemious, was lured into similar excesses by the young Earl of Warwick and Colley Cibber, during his visits to London, whilst engaged on his translation of the _Iliad_, and writes to Congreve, 'I sit up till two o'clock over Burgundy and Champagne.'[321] A proof of the popularity of French wines at this period is found in the fact that in 1713, the year of the Peace of Utrecht, the registered imports, despite high duties, reached 2551 tuns, an amount not exceeded till 1786. The Treaty of Commerce, with which Bolingbroke (whose partiality to Champagne we have seen) and M. de Torcy sought to supplement that of Peace, having fallen through, the tavern-keepers put such a price on these wines that it was only members of the fashionable world who could afford to have what was termed 'a good Champagne stomach.'[322] Their vogue is confirmed by the order given to her servant by a lady aspiring to take a leading position in the _beau monde_ to 'go to Mr. Mixture, the wine-merchant, and order him to send in twelve dozen of his best Champaign, twelve dozen of Burgundy, and twelve dozen of Hermitage,'[323] as the entire stock for her cellar. 'Good wine' was indeed, in those days, 'a gentleman.' [Illustration: 'GOOD WINE A GENTLEMAN.'] The unvarying rule that the fashions set by the most select are inevitably aped by the most degraded, so far as lies in their power, is exemplified in the Tavern Scene of Hogarth's _Rake's Progress_, where the table at which the hero and his _inamoratas_ are seated is set out with the tall wine-glasses wherein 'Champaign goes briskly round.'[324] [Illustration: TAVERN SCENE FROM 'THE RAKE'S PROGRESS.'] The Jacobites, faithful to their traditional ally, continued to toast 'the King over the water' by passing glasses charged with the sparkling wine of France across a bowl filled to the brim with the pure element. The middle classes clung to their beer, or at most indulged in Port and punch; whilst the lower orders seem to have become seized with that insane passion for ardent spirits which Hogarth satirised in his 'Gin Lane,' and hailed with glee Sir Robert Walpole's 'attempt, Superior to Canary or Champagne, Geneva salutiferous to enhance.'[325] [Illustration: 'THE KING OVER THE WATER.'] [Illustration] The registered imports of the wines of France--though figures in this respect are, we admit, exceedingly deceptive--show a continuous falling off, which reached its lowest ebb in 1746, during war time; and we may be certain that when, after supper, 'Champagne was the word for two whole hours by Shrewsbury clock,'[326] it was at the cost of a pretty penny. Although the recorded imports of French wines show but little improvement with the return of peace in 1748, we gather from other sources that the Champagne of 1749 met with a ready market over here, and find Bertin du Rocheret writing exultingly to his friend, the Marquis de Calvières, that the Champenois were making the English pay the cost of the war. The voluminous correspondence of Bertin du Rocheret gives some curious information as to the manner in which the Champagne trade was carried on with England during the second quarter of the eighteenth century. From 1725 to 1754 he was in constant communication with Mr. James Chabane, who seems to have been the Court wine-merchant, and to whom he despatched at first ten, but during the latter portion of their transactions seldom more than four, pièces of wine annually during the winter months.[327] As regards the particular vintage consumed in England, a preference evidently existed for that of Ay, though it really appears as if Bertin was wont to introduce under this name the then far cheaper growths of Avize. Such, at any rate, seems to have been the case with the parcel of wine divided, in 1754, between King George in London and King Stanislas at Nancy. Referring to the wines of Hautvillers and Sillery, Bertin writes to Chabane in 1731, that a year's notice must be given in advance to obtain them. A _liquoreux_ wine was then preferred, as in 1732 he remarks, respecting the yield of the preceding year, that the English are as mad after _liqueur_ as the French; and it is evident that the taste continued, as in 1744 he announces the departure for London of eleven poinçons _liquoreux_. Not only was Chabane accustomed to bottle these wines, but while doing so was able to insure to them a semi-sparkling character. With this view Bertin tells him, in 1731, that he must not keep them in cask after the three _sèves_, or motions of the sap of April, June, or August, except in the case of a pièce from 'the _clos_' reserved 'for the supply of the Court,' and intended to be drunk as still wine. Some wine despatched in 1754 is recommended to be bottled during the first quarter of the moon.[328] In addition to the wine thus sent in casks, Bertin was also accustomed to send his correspondent a certain quantity in bottles. In 1725 he quotes for him 'flacons blancs mousseux liqueur,' at from 30 to 50 sols, and 'ambrés non-mousseux sablant,' at 25 sols. These flasks were all despatched to Dunkirk or into Holland, whence they were smuggled to their ultimate destination, for the introduction of wine in bottles into England was rigidly prohibited until the close of 1745, when it was legalised by Act of Parliament.[329] Horace Walpole, who deals with men rather than manners, with sayings rather than doings, and whose forte is epigram and not description, has little to tell us about the drinking customs of his day. The strictly temperate regimen that marked his later years, and rendered him unfit for mere convivial gatherings, extended to his writings, and he seldom permits his pen to expatiate on those pleasures in which he sought no share. Even in his letters from Reims, written in 1739, when he was doing the grand tour, he omits all mention of the wine for which that city is famed. Still he incidentally furnishes a few instances of the esteem in which Champagne was held by the upper classes in the middle of the eighteenth century. In a letter to George Montague, dated June 23, 1750, he describes how Lord Granby joined his party at Vauxhall whilst suffering considerably under the influence of the Champagne he had consumed at 'Jenny's Whim,' a noted tavern at Chelsea; and writing to Sir Horace Mann, a year later, he says that the then chief subjects of conversation in London were the two Miss Gunnings and an extravagant dinner at White's. [Illustration: SCENE AT VAUXHALL GARDENS (From an engraving after a drawing by Gravelot).] 'The dinner was a frolic of seven young men, who bespoke it to the utmost extent of expense; one article was a tart made of duke cherries, from a hothouse; and another, that they tasted but one glass out of each bottle of Champagne. The bill of fare has got into print, and with good people has produced the apprehension of another earthquake.'[330] The Earl of March, afterwards 'Old Q,' in a letter to Walpole's friend, George Selwyn, in November 1766, writes: 'I have not yet received some Champaign that Monsieur de Prissieux has sent me.'[331] And we find Horace Walpole's fair foe, that eighteenth-century exemplar of strong-minded womanhood, Lady Mary Wortley Montague, whose letters indicate a _penchant_ for Burgundy, acknowledging in verse the exhilarating effects of Champagne. Of the _beaux_ of 1721 she says that 'They sigh, not from the heart but from the brain, Vapours of vanity and strong Champagne.'[332] Better known by far are her oft-quoted lines, 'But when the long hours of the public are past, And we meet with Champagne and a chicken at last, May every fond pleasure that moment endear, Be banished afar both discretion and fear,'[333] which drew from Byron the terror-stricken comment, 'What say you to such a supper with such a woman?'[334] [Illustration] [Illustration] During the third quarter of the eighteenth century a cloud dims the lustre of Champagne. It was then looked upon by a vast majority as only a fit accompaniment to masquerades, ridottos, ultra-fashionable dinners, and Bacchanalian suppers. 'The Champaign made some eyes sparkle that nothing else could brighten,'[335] says the contemporary account of one of those scenes of shameless revelry held under the title of masquerades at the Pantheon, and the orgies that, under the auspices of Mrs. Cornelys, disgraced Carlisle House were mainly inspired by the consumption of the same wine. The citizens of the Georgian era, who had lost the tastes of their fathers, hated French wines simply because they were French; and the hundred thousand gallons imported on an average annually from 1750 to 1786 were entirely consumed amongst the upper or the dissipated classes. Though smuggling was still looked upon as patriotic, if not loyal, those engaged in it had discovered that, thanks to the combined effects of duty and demand, Nantes brandy and Hollands gin paid better. What, indeed, is to be thought of the taste of an era that produced poets whose muse sought inspiration in punch, and who had the sublime audacity to extol the rum of the West Indies above the produce of 'Marne's flowery banks'?[336] Only a few of the higher-class men, however, engaged in literature and art seem to have retained a preference for French wine. The accounts of the Literary Club established by Sir Joshua Reynolds show the average consumption at each sitting to have been half a bottle of Port and a bottle of Claret per head. Johnson drank Port mixed with sugar from about 1752 to 1764; became a total abstainer until 1781, and then seems to have given the preference to Madeira. [Illustration: THE LITERARY CLUB.] In contemporaneous comedy we are pretty sure to find the mirror held up to fashion, if not to Nature; and turning to the playwrights of that day, it is easy to cull a few confirmatory excerpts. Thus we have Sterling, the ambitious British merchant, in order to do honour to his noble guests, preparing to 'give them such a glass of Champaign as they never drank in their lives; no, not at a duke's table.'[337] While Lord Minikin, the peer of fashion, makes his entrance on the stage, exclaiming: 'O my head! I must absolutely change my wine-merchant; I cannot taste his Champaigne without disordering myself for a week.'[338] On Miss Tittup inquiring if his depression is due to losses at cards, he replies, 'No, faith, our Champaigne was not good yesterday.'[339] Jessamy, his lordship's valet, profits of course by so aristocratic an example; and when speaking of his exploits at the masquerade, says, 'I was in tip-top spirits, and had drunk a little too freely of the Champaigne, I believe.'[340] With Philip the butler, 'Burgundy is the word,' and from the choicest vintages of his master's cellar he places on the table 'Claret, Burgundy, and Champaign; and a bottle of Tokay for the ladies;'[341] while Port is characterised by the Duke's servant as 'only fit for a dram.'[342] Mrs. Circuit presses the guests at a clandestinely-given repast to 'taste the Champagne;' and her husband, the Sergeant, is surprised on his return home to find that they have been so indulging: 'Delicate eating, in truth; and the wine [_Drinks_] Champagne, as I live! Must have t'other glass ... delicate white wine, indeed! I like it better every glass.'[343] Such is his comment. The effects of the wine are characterised in the following fashion by Garrick, when Sparkish, entering, according to the stage directions, 'fuddled,' declares that 'when a man has wit, and a great deal of it, Champaign gives it a double edge, and nothing can withstand it; 'tis a lighted match to gunpowder; the mine is sprung, and the poor devils are tossed heels uppermost in an instant.'[344] [Illustration: LORD MINIKIN.] We greet, too, what was perhaps the first appearance of a joke now grown venerable in its antiquity in a farce of Foote's, the scene of which is laid at Bath. He introduces us to a party of pseudo-invalids devoting their whole time and attention to conviviality, recruiting their debilitated stomachs with turtle and venison, and alternating Bath waters with the choicest vintages, so that the hero Racket is fain to observe to one of them, 'My dear Sir Kit, how often has Dr. Carawitchet told you that your rich food and Champaigne would produce nothing but poor health and real pain?'[345] And how many gentlemen in difficulties have not since followed the example set by Harry Dornton in the spunging-house, and ordered, as a consolation, 'a bottle of Champagne and two rummers'![346] Turning from fancy to fact, we find Sir Edward Barry furnishing some particulars respecting the Champagne wines consumed in England during the latter half of the last century.[347] He informs us at the outset that 'the wines of Champaign and Burgundy are made with more care than any other French wines; and the vaults in which the former are preserved are better than any other in France. These wines, from their finer texture and peculiar flavour, cannot be adulterated without the fraud being easily discovered, and are therefore generally imported pure, or by proper care may be certainly procured in that state.' His remarks evidently refer to the still wines, as he proceeds to explain that 'the Champaign River Wines are more delicate and pale than those which are distinguished from them by the name of Mountain gray Wines,' the latter being more durable and better suited for exportation, whilst the former, if allowed to remain too long in the cask, acquire a taste from the wood, although keeping in flasks from four to six years without harm. Referring to the taste of the day, he explains that 'among the River Wines the Auvillers and Epernay are most esteemed, and among the Mountain Wines the Selery and St. Thyery, and in general such as are of the colour of a partridge's eye. These are likewise distinguished for their peculiar grateful pungency and balsamic softness, which is owing to the refined saline principle which prevails more in them than in the Burgundy Wines, on which account they are less apt to affect the head, communicate a milder heat, and more freely pervade and pass through the vessels of the body.... To drink Champaign Wines in the greatest perfection, the flask should be taken from the vault a quarter of an hour before it is drunk, and immersed in ice-water, with the cork so loose in it as is sufficient to give a free passage to the air, and yet prevent too great an evaporation of its spirituous parts.' [Illustration: HIGH LIVING AT BATH (After Rowlandson, in the _New Bath Guide_).] The foregoing practice still obtains with Sillery, classed by Barry as the first of the Mountain growths, and in the highest favour in England throughout the remainder of the century. Regarding sparkling wine, of which he was evidently no admirer, he adds: 'For some years the French and English have been particularly fond of the sparkling frothy Champaigns. The former have almost entirely quitted that depraved taste, nor does it now so much prevail here. They used to mix some ingredients to give them that quality; but this is unnecessary, as they are too apt spontaneously to run into that state; but whoever chooses to have such Wines may be assured that they will acquire it by bottling them any time after the vintage before the month of the next May; and the most sure rule to prevent that disposition is not to bottle them before the November following. This rule has been confirmed by repeated experiments.' On the signature of the Treaty of Peace with France in 1783, it had been stipulated that a Treaty of Commerce should likewise be concluded; and in 1786, under the auspices of Pitt, a treaty of this character was made, the first article providing that 'The wines of France imported directly from France into Great Britain shall in no case pay any higher duties than those which the wines of Portugal now pay.' Pitt, spite of his well known _penchant_ for Port, had yet a sneaking liking for Champagne, arising no doubt from his early familiarity with the wine when he went to Reims to study, after leaving the University of Cambridge. It was with Champagne that he was primed on the memorable occasion when he, Lord Chancellor Thurlow, and Mr. Secretary Dundas galloped after dusk through an open turnpike-gate without paying toll, and only just missed receiving the contents of a loaded blunderbuss, which the turnpike man, fancying they were highwaymen, fired after them. The party had been dining with the President of the Board of Trade at Addiscombe, and a rhymester of the epoch commemorated the incident in the following lines: 'How as Pitt wandered darkling o'er the plain, His reason drowned in Jenkinson's Champagne, A rustic's hand, but righteous fate withstood, Had shed a premier's for a robber's blood.' [Illustration: DUNDAS AND PITT AS SILENUS AND BACCHUS (After Gilray).] [Illustration: WILLIAM PITT (After Gilray).] Tickell has noted the appreciation of Brooks' Champagne shown by Pitt's great rival in the lines addressed to Sheridan, and purporting to be an invitation to supper from Fox. The illustrious member for Westminster promises his guest that 'Derby shall send, if not his plate, his cooks, And know I've bought the best Champaign from Brooks.'[348] Brooks' Club enjoyed a high reputation for its Champagne, and we find Fighting Fitzgerald emptying three bottles there without assistance, the same evening on which he bullied the members into electing him.[349] The year after the Treaty of Commerce was signed, we have an anonymous writer remarking[350] that in time of peace the English drew large quantities of wine from Bordeaux and Nantes, and that the other French wines they were in the habit of consuming were those of Mantes, Burgundy, and Champagne, shipped respectively from Rouen, Dunkirk, and Calais. Arthur Young, writing at the same time, remarks, _apropos_ of Champagne, that the trade with England 'used to be directly from Epernay; but now the wine is sent to Calais, Boulogne, Montreuil, and Guernsey, in order to be passed into England they suppose here by smuggling. This may explain our Champagne not being so good as formerly.'[351] It is to be hoped that neither Arthur Young nor other connoisseurs of Champagne had been enticed into drinking as the genuine article any of the produce of the vineyard which the Hon. Charles Hamilton had planted with the Auvernat grape near Cobham, in Surrey, and which was said to yield a wine 'resembling Champagne.'[352] The reduction of duty consequent upon the treaty as a matter of course largely increased the importation of French wine. Respecting the taste for Champagne then prevailing in England, and the price the wine commanded, a few interesting particulars are afforded by the early correspondence and account-books of Messrs. Moët & Chandon of Epernay, which we have courteously been permitted to inspect. From these we find that in October 1788 the Chevalier Colebrook, writing in French to the firm from Bath, asks that seventy-two bottles of Champagne may be sent to his friend, the Hon. John Butler of Molesworth-street, Dublin, 'who, if content with the wine, will become a very good customer, being rich, keeping a good house, and receiving many amateurs of _vin de Champagne_.' The writer is no doubt the 'M. Collebrock' to whom the firm shortly afterwards forward fifty bottles of '_vin non mousseux_, 1783,' on his own account. Messrs. Carbonnell, Moody, & Walker, predecessors of the well-known existing firm of Carbonnell & Co., London, in a letter dated November 1788, and also written in French, say: 'If you can supply us with some Champagne of a very good body, not too much charged with liqueur, but with an excellent flavour, and not at all _moussu_, we beg you to send two ten dozen baskets. Also, if you have any dry Champagne of very good flavour, solidity, and excellent body, send two baskets of the same size.' The taste of the day was evidently for a full-bodied non-sparkling wine; and this is confirmed by Jeanson, Messrs. Moët's traveller in England, who writes from London in May 1790: 'How the taste of this country has altered within the last ten years! Almost everywhere they ask for a dry wine; but they want a wine so vinous and so strong, that there is hardly anything but Sillery that will satisfy them.' Additional confirmation is found in a letter, written from London in May 1799 to Messrs. Moët, by a Mr. John Motteux, complaining of delay in the delivery of a parcel of wine said to have been sent off by way of Havre, and very likely destined to be surreptitiously introduced into England _viâ_ Guernsey. He asks for a further supply of Sillery, if its safe arrival can be guaranteed, and remarks, 'There is nothing to be compared to Sillery when it is genuine; it must not have the least sweetness nor _mousse_.'[353] During the great French war, patriotism and increased duties might have been expected to check the import of French wines; yet, if statistics are worth anything, the reverse would appear to have been the case. The registered imports, which from 1770 to 1786 had fluctuated between 80,000 and 125,000 gallons, rose during the last fourteen years of the century to an average of 550,000 gallons per annum. In those fighting, rollicking, hard-drinking times, when it was a sacred social duty to toast 'great George our King' on every possible occasion, Champagne continued to be 'the wine of fashion.' The sparkling variety was terribly costly, no doubt, and was often doled out, as Mr. Walker relates, 'like drops of blood.'[354] But whilst the stanch admirers of Port might profess to despise Champagne as effeminate, and the 'loyal volunteers' condemn it as the produce of a foeman's soil, there were plenty to sing in honour of 'The Fair of Britain's Isle:' 'Fill, fill the glass, to beauty charge, And banish care from every breast; In brisk Champaign we'll quick discharge, A toast shall give the wine a zest.'[355] Indeed, the greatest of England's naval heroes was not insensible to the attractions of this gift from 'our sweet enemy France.' In October 1800 Nelson, together with Sir William and Lady Hamilton, was a guest of Mr. Elliot, the British Resident at Dresden. At dinner Lady Hamilton drank more Champagne than the narrator of this little incident imagined it was possible for a woman to consume, and inspired thereby, insisted on favouring the company with her imitations of classical statuary. Nelson thereupon got uproarious, and went on emptying bumper after bumper of the same fluid in honour of the fair Emma, and swearing that she was superior to Siddons. The host kept striving 'to prevent the further effusion of Champagne,' but did not succeed till Sir William in his turn had astonished all present with a display of his social talents. The grave diplomatist lay down on his back, with his arms and legs in the air, and in this position bounded all round the room like a ball, with his stars and ribbons flying around him.[356] If we may give credit to Tom Moore, 'the best wigged prince in Christendom,' who was subsequently to 'd---- Madeira as gouty,' and bring Sherry into fashion, preferred stronger potations than those produced on the banks of the Marne. In one of the poet's political skits the Prince is introduced soliloquising _à la_ Jemmy Thompson-- 'O Roman Punch! O potent Curaçoa! O Maraschino! Maraschino O! Delicious drams'[357]-- and describing his favourite luncheon as 'good mutton cutlets and strong curaçoa.'[358] Nevertheless, the First Gentleman in Europe did consume Champagne; but it was concentrated in the form of punch, especially devised for him, and indulged in by him in company with Barrymore, Hanger, and their fellows.[359] His sometime model and subsequent victim, poor Brummell, is said to have put the wine to a still more ignoble use. One day a youthful beau approached the great master in the arts of dress and deportment, and said, 'Permit me to ask you where you get your blacking?' 'Ah,' replied Brummell, gazing complacently at his boots, 'my blacking positively ruins me. I will tell you in confidence it is made with the finest Champagne.'[360] Probably the great dandy was merely quizzing his interlocutor, though such an act of extravagance would have been a pull on even the longest purse in those days, 'your bottle of Champagne in the year 1814 costing you a guinea.'[361] [Illustration: THE PRINCE REGENT (After Gilray).] As to the Prince Regent's brothers, we know that the Duke of York was such a powerful toper, that 'six bottles of Claret after dinner scarce made a perceptible change in his countenance,'[362] and remember the Duke of Clarence making his appearance at the table of the Royal household at Windsor, and getting so helplessly drunk on Champagne as to be utterly incapable of keeping his promise to open the ball that evening with his sister Mary.[363] Two prominent orators of that day are credited with _mots_ upon Champagne. Curran said, _apropos_ of the rapid but transient intoxication produced by this wine, that 'Champagne made a runaway rap at a man's head;' while Canning maintained that any man who said he really liked dry Champagne simply lied. After Waterloo, although a few _gourmets_ continued to prefer the still wine, sparkling Champagne became the almost universally accepted variety. Nevertheless, Henderson, while noting that 'by Champagne wine is usually understood a sparkling or frothy liquor,' gives the foremost place to the wine of Sillery, which, he remarks, 'has always been in much request in England, probably on account of its superior strength and durable quality.' He extols the Ay wine as 'an exquisite liquor, lighter and sweeter than the Sillery, and accompanied by a delicate flavour and aroma somewhat analogous to that of the pine-apple.'[364] The poets of the first half of the present century have hardly done justice to Champagne. Tom Moore, the most Anacreontic of them all, although ready, like his Grecian prototype, to 'pledge the universe in wine,' the merits of which he was continually chanting in the abstract, has seldom been so invidious as to particularise any especial vintage. Champagne, the wine of all others best fitted to inspire his bright and sparkling lyrics, has received but scant attention in his earlier productions. Bob Fudge, writing from Paris in 1818, is made to speak approvingly of Beaune and Chambertin, but only mentions Champagne as a vehicle in which to _sauter_ kidneys;[365] and in the _Sceptic_ it is simply brought in to point a moral respecting the senses: 'Habit so mars them, that the Russian swain Will sigh for train-oil while he sips Champagne.'[366] In two instances only the poet who sang in such lively numbers of woman and wine pointedly refers to the vintage of the Champagne. One is when he says: 'If ever you've seen a party Relieved from the presence of Ned, How instantly joyous and hearty They've grown when the damper was fled. You may guess what a gay piece of work, What delight to Champagne it must be, To get rid of its bore of a cork, And come sparkling to you, love, and me.'[367] And his description of a summer _fête_ is indeed 'a mere terrestrial strain Inspired by naught but pink Champagne;'[368] such as might be penned 'While as the sparkling juice of France High in the crystal brimmers flowed, Each sunset ray, that mixed by chance With the wine's diamond, showed How sunbeams may be taught to dance;'[369] with the final result that 'Thus did Fancy and Champagne Work on the sight their dazzling spells, Till nymphs that looked at noonday plain Now brightened in the gloom to belles.'[370] Moore's Diary, however, proves that if he did not care to praise the wine in verse, it was not for want of opportunities of becoming acquainted with it. Witness his 'odd dinner in a borrowed room' at Horace Twiss's in Chancery-lane, with the strangely incongruous accompaniments of 'Champagne, pewter spoons, and old Lady Cork.'[371] As to that most convivial of songsters, Captain Charles Morris, poet-laureate of the Ancient Society of Beefsteaks, he labours under a similar reproach. Though he has filled several hundred octavo pages of his _Lyra Urbanica_ with verses in praise of wine, the liquor with which he crowns 'the mantling goblet,' 'the fancy-stirring bowl,' or 'the soul-subliming cup,' usually figures under some such fanciful designation as 'the inspiring juice,' 'the cordial of life,' or 'Bacchus' balm.' Champagne he evidently ignores as a beverage of Gallic origin, utterly unfitted for the praise of so true a Briton as himself; and the only vintage which he does condescend to mention with approbation is the favourite one of our beef-eating, hard-drinking, frog-hating forefathers, 'old Oporto' from 'the stout Lusitanian vine.' [Illustration: CAPTAIN CHARLES MORRIS (After Gilray).] Strange as it may seem, the manlier Muse of Scott used at times to dip her wing into the Champagne cup, although she has failed to express any verbal gratitude to this source of inspiration. 'In truth,' says his biographer, 'he liked no wines except sparkling Champaign and Claret; but even as to this last he was no connoisseur, and sincerely preferred a tumbler of whisky-toddy to the most precious liquid ruby that ever flowed in the cup of a prince. He rarely took any other potation when alone with his family; but at the Sunday board he circulated the Champaign briskly during dinner, and considered a pint of Claret each man's fair share afterwards.'[372] Scott himself, wearied with a round of London festivities, is impelled to write, 'I begin to tire of my gaieties. I wish for a sheep's head and whisky-toddy against all the French cookery and Champaign in the world.'[373] Lockhart, in his _Life of Scott_, notes the excellent flavour of some Champagne sent to Abbotsford by a French admirer of the Northern Wizard in return for a set of his works, and more than once incidentally refers to the presence of the wine at Scott's table on festive gatherings. Byron, who furnished in the course of his career a practical exemplification of the maxim that 'Comus all allows Champaign, dice, music, or your neighbour's spouse,'[374] did the vintage of the Marne justice in his verses. In _Don Juan_ he shows himself not insensible to the charms of 'Champagne with foaming whirls As white as Cleopatra's melted pearls.'[375] The wine, moreover, furnishes two striking comparisons in that poem--one when he observes that 'The evaporation of a joyous day Is like the last glass of Champagne, without The foam which made its virgin bumper gay;'[376] and the other, where, in his sketch of Lady Adeline Amundeville, he rejects the trite metaphor of the snow-covered volcano in favour of 'a bottle of Champagne Frozen into a very vinous ice, Which leaves few drops of that immortal rain; Yet in the very centre, past all price, About a liquid glassful will remain; And this is stronger than the strongest grape Could e'er express in its expanded shape: 'Tis the whole spirit brought to a quintessence; And thus the chilliest aspects may concentre A hidden nectar under a cold presence.'[377] Although we find Henderson remarking, in 1822, that 'the pink Champagne is less in request than the colourless, and has in fact nothing to entitle it to the preference,' yet wine of this tint continued to reappear from time to time, securing a transitory popularity from its attractive appearance, which caused it to be likened to the dying reflection of the setting sun on a clear stream. An interesting incident in connection with its advent on one of these occasions at the table of Rogers, the banker-poet, has been recorded by Mr. R. A. Tracy Gould of the American Bar. He was dining, it seems, in company with Tom Moore and John Kenyon, with Rogers at St. James's-place, when their host, who had recently received through the French Ambassador a present of a case of pink Champagne from Louis Philippe, had the first bottle of it produced at the end of the dinner. The saucer-shaped Champagne glasses were then just coming into use, and pink Champagne, which was a revived novelty in England at that moment, looked singularly beautiful in them, crowned with its snow-white foam. Kenyon, who, as Gould remarks, was nothing if not declamatory, held up his glass, and apostrophised it as follows: 'Lily on liquid roses floating! So floats yon foam o'er pink Champagne! Fain would I join such pleasant boating, And prove that ruby main, And float away on wine!' This being vociferously applauded, after a few minutes' pause he added the second verse: 'Those seas are dangerous, graybeards swear, Whose sea-beach is the goblet's brim; And here it is they drown dull Care-- But what care we for him? So we but float on wine!' On being desired to continue, Kenyon declared that he had done his part, and that it was now the turn of some one else. Moore and Rogers both claimed exemption, as being on the 'retired list' of the Parnassian army, and peremptorily demanded a contribution from the Transatlantic guest, Tracy Gould, who thereupon, with 'great diffidence,' as he tells us, delivered himself of the third and fourth stanzas: 'Gray Time shall pause and smooth his wrinkles, Bright garlands round his scythe shall twine; While sands from out his glass he sprinkles, To fill it up with wine-- With rosy sparkling wine! Thus hours shall pass which no man reckons, 'Mongst us, who, glad with mirth divine, Heed not the shadowy hand that beckons Across the sea of wine-- Of billowy gushing wine!' Kenyon then added another stanza, which suggested a final verse to the American: 'And though 'tis true they cross in pain, Who sober cross the Stygian ferry, Yet only make our Styx Champagne, And we shall cross right merry, Floating away on wine!' 'Old Charon's self shall make him mellow, Then gaily row his bark from shore; While we and every jolly fellow Hear unconcerned the oar That dips itself in wine!' By this time the inspiration and the Champagne were alike exhausted. The history of Champagne in England during the latter half of the present century may be briefly summed up in the assertion of the ever-growing popularity of the wine, and the high repute attained by certain brands, which it would be invidious to particularise. Its success in oiling the wheels of social life is so great and so universally acknowledged that its eclipse would almost threaten a collapse of our social system. We cannot open a railway, launch a vessel, inaugurate a public edifice, start a newspaper, entertain a distinguished foreigner, invite a leading politician to favour us with his views on things in general, celebrate an anniversary, or specially appeal on behalf of a benevolent institution without a banquet, and hence without the aid of Champagne, which, at the present day, is the obligatory adjunct of all such repasts. When the Municipality of London welcome the Khan of Kamschatka to our shores and to the Guildhall, Champagne flows in the proverbial buckets full. When the Master and Wardens of the Coalscuttle-Makers' Company bid the Livery to one of their periodical feasts, scandal says that even this measure is exceeded. When Sir Fusby Guttleton gives one of his noted 'little spreads' at Greenwich, are not torrents of iced 'dry' needed to quench the thirst excited by the devilled bait? Aware, too, of the unloosening effect the wine exercises upon the strings of both heart and purse, Pomposo, as chairman at the annual festival of the Decayed Muffinmongers' Asylum, is careful to see that the glasses of the guests have been well charged with it before he commences his stirring appeal on behalf of that deserving institution. Does Ingenioso wish to introduce to the notice of the British public a new heating-power or lighting-apparatus or ice-making machinery, he straightway issues cards for a private view to critics and cognoscenti, and is careful that these shall observe the merits of his invention through the medium of a glass--bubbling over with Champagne. So it is at the openings of the latest extension of the Mugby Junction Railway and of the Palatial Hotel, at the private view of the Amicable Afghans, or Tinto's new picture, or any one of Crotchet's manifold inventions. If the bidding, too, flags at a sale of shorthorns or thoroughbreds, at a wink from the auctioneer the Champagne-corks are set a-popping, and advance promptly follows advance in responsive echoes. Not less important is the part that Champagne plays in the City. Capel Crash, the great financier, literally _floats_ the concerns he deigns to 'promote' by its agency. When Consol, the millionaire, makes one of a set for rigging the market, and the 'ring' thus formed has reaped the reward of their ingenuity, does he not entertain his intimate friends with the story and with the choicest Champagne? The amount of business, moreover, transacted by the aid of the wine is incalculable. Bargains in stocks and shares, tea and sugar, cotton and corn, hemp and iron, hides and tallow, broadcloth and shoddy, are clinched by its agency. On the other hand, many a bit of sharp practice has been forgiven, many a hard bargain has been forgotten, many a smouldering resentment has been quenched for ever, and many an enmity healed and a friendship cemented, over a bottle of Champagne. [Illustration: 'I say, old fellow, how do you go to the Derby this year?' 'O, the old way--hamper-and-four.' (From a drawing by John Leech in 'Punch.')] [Illustration: AT THE DERBY (From a drawing by John Leech in 'Punch.')] The Turf is said to be our national pastime, and no one will deny the close connection existing between sport and Champagne. From the highest to the lowest of that wonderful agglomeration of individuals interested in equine matters, it is recognised as the only standard 'tipple.' Champagne goes down to the Derby in its hamper-and-four, like other pertinacious patrons of the race, and its all but ubiquitous presence on the course is warmly welcomed by thousands of thirsty visitors of very various grades. At Ascot, does H. R. H. the Prince of Wales seek to congratulate the Marquis of Hartington on his success, it is by wishing him further success in a glass of sparkling wine. Does Mr. William Kurr, welsher, desire to make the acquaintance of Mr. Druscovitch, detective, he seeks an introduction from Mr. Meiklejohn over a bottle of 'fiz.' Does the favourite horse win--quick, fill high the bowl with sparkling wine, to celebrate his triumph; does he lose, the same vintage will serve to drown our sorrows and obliterate the recollection of our losses. How many cunning _coups_, how many clever combinations, have there not been worked out in all their details over a bottle of 'Cham.' in quiet hotel-parlours at Doncaster or Newmarket! How many bets have been laid and paid in the same medium! How many a jockey has been bought, and how many a race has been sold, owing to the moral as well as physical obliquity of vision which the ingurgitation of the wine has induced! Nor should the existence of Champagne Stakes be forgotten. There are now several races of this name at different meetings; but the oldest is that established at Doncaster in 1828, and taking its title from the fact of the owner of the winner having to present six dozen of Champagne to the Doncaster Club. [Illustration: _Jones_: 'I say, Brown, things are deuced bad in the City.' _Brown_: 'Then I'm deuced glad I'm at Epsom.' (From a drawing by John Leech in 'Punch.')] [Illustration] [Illustration: AT THE STAR AND GARTER, RICHMOND.] Look, too, at the influence exercised by the wine on the British drama, or rather on what to-day passes as such. Plagioso the playwright freely opens a bottle of Champagne with the object of stimulating the wit of his friend and collaborateur in the task of adapting Messrs. Meilhac & Halévy's latest production to the London stage. Adverse critics, moreover, are said to be mollified by the subjugating influence of the wine; while authors, enraged at the way in which their pieces have been 'cut,' are similarly soothed; squabbles too between rival _artistes_ as to parts and lengths are satisfactorily arranged in the managerial sanctum over a bottle of fiz. Does Lord Nortiboy wish to smooth over a tiff with the tow-haired young lady who is making ducks and drakes of his money at the Gynarchic Theatre, and whose partiality for sparkling wine is notorious, a dinner at Richmond and floods of 'Cham' for herself and friends is the plan that naturally suggests itself. Should the enterprising lessees of the Chansonnette Theatre determine to celebrate the thousand and first night of the run of _Their Girls_, a Champagne supper is recognised as the fit and proper method of doing so. Supper is the favourite meal of the profession, and Champagne is of course the best of all wine to take at that repast. On the stage itself it has often proved of very serious service. Robust tragedians and prima donnas in good training may indulge in stout, as more 'mellering to the organ;' but by the judicious administration of Champagne many a nervous _débutant_ has been encouraged to conquer 'stage fright' and to face the footlights, many a jaded _tragédienne_ enabled to rally her fainting energies in the last act, and to carry her audience with her in a final outburst of pathos or passion. Statesmen no longer prime themselves with Port before strolling down to the House, till they get into the condition of the two members, one of whom averred that he could not see any Speaker in the chair, whilst the other gravely accounted for the phenomenon of this disappearance by asserting that, for his part, he saw a couple. Perhaps it is to be regretted that the records of the 'tea-room' do not vouch for a larger consumption of Champagne, as then perhaps the reporters overnight and their readers the nest morning might escape the wearisome reiteration of purposeless recrimination and threadbare platitudes. Such should certainly be the case, since the power of the wine as an incentive to brisk and sparkling conversation has been universally acknowledged in social life. [Illustration: 'Now, George, my boy, there's a glass of Champagne for you. Don't get such stuff at school, eh?' 'H'm! Awfully sweet. Very good sort for ladies. But I've arrived at a time of life when I confess I like my wine dry.' (From a drawing by John Leech in 'Punch.')] To the dinners of Bloomsbury and Belgravia, as well as the suppers of Bohemia, Champagne imparts a charm peculiarly its own by placing all there present _en rapport_. The modern mind may well look back with shuddering horror to that dreary period when Champagne, if given at all, was doled out at dinner-parties 'like drops of blood.' No wonder the ladies used to fly from the table and the gentlemen to slide underneath it. And, speaking of the ladies, is not Champagne their wine _par excellence_? How would the fragile products of modern civilisation be able to outdo the most robust of their ancestresses--whose highest saltatory feats were the execution of the slow and stately minuet, the formal quadrille with its frequent rests, or at most the romping country dance--by whirling almost uninterruptedly in the mazes of the giddy waltz from nine in the evening until five in the morning, without the sustaining power the sparkling fluid affords them? Has it not on their tongues an influence equal to that which it exercises on their swiftly-flying feet, inspiring pretty prattle, sparkling repartee, enchanting smiles, and silvery laughter? Old Bertin du Rocheret was quite right when he invited his fair friends to continue drinking 'De ce nectar délicieux, Qui pétille dans vos beaux yeux Mieux qu'il ne brille dans mon verre.' Since these lines were penned, many thousands of bright eyes have so borrowed an additional lustre. [Illustration] [Illustration] It would certainly be going too far to suggest that flirtation and Champagne must have been introduced simultaneously, yet the former can only have attained perfection since the advent of the latter. Only consider what a failure a picnic or a garden-or water-party, or any other kind of entertainment to which that much-abused term _fête champêtre_ is applied, and where flirtation would be, without Champagne! As a matrimonial agent, Champagne's achievements outdo those of the cleverest of man[oe]uvring mammas. It was solely those two extra glasses at supper which emboldened young Impey Cue of the Foreign Office to summon up sufficient courage to propose in the conservatory to Miss Yellowboy, the great heiress; and Impey Cue now lords it at Yellowboy Park as though to the manor born. Nor must the part it plays on the eventful day when the fatal knot is firmly tied be overlooked. It has been cynically remarked that it is a painful spectacle even for the most hardened to witness the consigning of a victim to the doom matrimonial; and that it becomes all the more painful when, under the futile pretext of festivity, bewildered fathers, harassed mothers, sorrowing sisters, envious cousins, bored connections, and pitying friends, arrayed in their best attire, meet at an abnormally early hour round the miscalled social board. Still, fancy what a wedding breakfast would be without the accompaniment of Champagne! [Illustration: THE SOCIAL TREADMILL--THE WEDDING BREAKFAST (From a drawing by John Leech in 'Punch').] [Illustration: COMING OF AGE (Drawn by R. Caldecott).] With mamma in tears and papa in the fidgets, the bride half-way towards hysterics, and the bridegroom wishing from the bottom of his heart that the crowded dining-room would suddenly transform itself into a securely-locked first-class coupé speeding onwards in the direction of Dover, the task of those speakers on whom devolves the duty of descanting upon 'the happy occasion which has brought us together' is of a surety no easy one. And it would be still more uphill work were it not for the amount of cheerful inspiration fortunately to be drawn from the familiar foil-topped bottles. By and by, when the more serious speeches have been duly stammered through, and the jovial bachelor--a middle-aged one by preference--rises to propose 'the health of the bridesmaids,' bursts of laughter from the men and responsive titters, bubbling up like the sparkling atoms in the wine which has inspired them, from the lips of the damsels in question and their compeers, prove beyond question that Champagne has done its duty in dissipating the gloom originally prevailing. A wedding, too, is the customary precursor of other family gatherings at which the vintage of the Marne plays the same enlivening part. There are, for instance, christenings where godfathers bring as their offerings masterpieces of the silversmith's craft, and the infant's health is quaffed by turns in 'Sherry in silver, Hock in gold, and glassed Champagne;' for the wine of mirth is out of place in metal, however precious, and needs the purest crystal to exhibit all its finer qualities. There are also coming-of-age banquets, whereat young Hopeful is enabled to stumble and stutter through a series of jerky and disjointed phrases of thanks--commonplace as they may be, which never fail to awaken the tenderest emotions in the heart of the maternal author of his being--by the aid of sundry glasses of the sparkling wine of the Marne. 'O the wildfire wine of France! Quick with fantasies florescent, Rapturously effervescent, How its atoms leap and dance! Floric fount of love and laughter, Where its emanations rise All the difficulty dies From the now and the hereafter. Through the happy golden haze Time's gray cheek is bright with dimples, And his laugh more lightly wimples Than the sea's on summer days. Tongue and throat it makes to tingle, Beats the blood from heart to vein, And ascending to the brain, Bids the spirit forth and mingle With a world no longer grim, But serene and sweet and spacious, Where the girls are fair and gracious, And the Cupids light of limb. Soul and sense are all untethered! Who would be an angel when, Clement king of gods and men, He can soar so grandly, feathered With thy plumage, O Champagne? Bottled gladness! thou magician! Silver-bearded! mist Elysian! Ecstasy of sun and rain! Swift and subtle, glad and glorious, O the wildfire wine of France! How its atoms frisk and dance, Over Fate and Time victorious!' [Illustration] [Illustration: MAP OF THE CHAMPAGNE VINEYARDS, _Reduced, by permission, from the larger Map_. Drawn by /M. J. Lignier/, Staff-Captain, For Messrs. MÖET & CHANDON, of Epernay. The purple tint indicates the Vineyards. The yellow, the Woods and Forests. The green, the Meadows. The blue, the Ponds and Lakes. The figures indicate the altitudes in metres above the level of the sea. /Scale in Metres/: (_2000 Metres are equal to 1-1/4 Miles._)] [Illustration: THE VINEYARDS AND ABBEY OF HAUTVILLERS.] PART II. I. /The Champagne Vinelands--The Vineyards of the River./ The vinelands in the neighbourhood of Epernay--Viticultural area of the Champagne--A visit to the vineyards of 'golden plants'--The Dizy vineyards--Antiquity of the Ay vineyards--St. Tresain and the wine-growers of Ay--The Ay vintage of 1871--The Mareuil vineyards and their produce--Avernay; its vineyards, wines, and ancient abbey--The vineyards of Mutigny and Cumières--Damery and 'la belle hôtesse' of Henri Quatre--Adrienne Lecouvreur and the Maréchal de Saxe's matrimonial schemes--Pilgrimage to Hautvillers--Remains of the Royal Abbey of St. Peter--The ancient church--Its quaint decorations and monuments--The view from the heights of Hautvillers--The abbey vineyards and wine-cellars in the days of Dom Perignon--The vinelands of the Côte d'Epernay--Pierry and its vineyard cellars--The Moussy, Vinay, and Ablois St. Martin vineyards--The Côte d'Avize--Chavot, Monthelon, Grauves, and Cuis--The vineyards of Cramant and Avize, and their light delicate white wines--The Oger and Le Mesnil vineyards--Vertus and its picturesque ancient remains--Its vineyards planted with Burgundy grapes from Beaune--The red wine of Vertus a favourite beverage of William III. of England. [Illustration: CHÂTEAU DE BOURSAULT.] With the exception of certain famous vineyards of the Rhône, the vinelands of the Champagne may, perhaps, be classed among the most picturesque of the more notable vine-districts of France. Between Paris and Epernay, even, the banks of the Marne present a series of scenes of quiet beauty. The undulating ground is everywhere cultivated like a garden. Handsome châteaux and charming country houses peep out from amid luxuriant foliage. Picturesque antiquated villages line the river's bank or climb the hill-sides, and after leaving La Ferté-sous-Jouarre, the cradle of the Condés, all the more favoured situations commence to be covered with vines. This is especially the case in the vicinity of Château-Thierry--the birthplace of La Fontaine--where the view is shut in on all sides by vine-clad slopes, which the spring frosts seldom spare. Hence merely one good vintage out of four gladdens the hearts of the peasant proprietors, who find eager purchasers for their produce among the lower-class manufacturers of Champagne. In the same way the _petit vin de Chierry_, dexterously prepared and judiciously mingled with other growths, often figures as 'Fleur de Sillery' or 'Ay Mousseux.' In reality it is not until we have passed the ornate modern Gothic château of Boursault, erected in her declining years by the wealthy Veuve Clicquot, by far the shrewdest manipulator of the sparkling products of Ay and Bouzy of her day, and the many towers and turrets of which, rising above umbrageous trees, crown the loftiest height within eyeshot of Epernay, that we find ourselves in that charmed circle of vineyards whence Champagne--the wine, not merely of princes, as it has been somewhat obsequiously termed, but essentially the _vin de société_--is derived. The vinelands in the vicinity of Epernay, and consequently near the Marne, are commonly known as the 'Vineyards of the River,' whilst those covering the slopes in the neighbourhood of Reims are termed the 'Vineyards of the Mountain.' The Vineyards of the River comprise three distinct divisions--first, those lining the right bank of the Marne and enjoying a southern and south-eastern aspect, among which are Ay, Hautvillers, Cumières, Dizy, and Mareuil; secondly, the Côte d'Epernay on the left bank of the river, of which Pierry, Moussy, and Vinay form part; and thirdly, the Côte d'Avize (the region _par excellence_ of white grapes), which stretches towards the south-east, and includes the vinelands of Cramant, Avize, Oger, Le Mesnil, and Vertus. The entire vineyard area is upwards of 40,000 acres.[378] The Champagne vineyards most widely celebrated abroad are those of Ay and Sillery, although the last named are really the smallest in the Champagne district. Ay, distant only a few minutes by rail from Epernay, is in the immediate centre of the Vinelands of the River, having Mareuil and Avenay on the east, and Dizy, Hautvillers, and Cumières on the west; while Sillery lies at the foot of the so-called Mountain of Reims, and within an hour's drive of the old cathedral city. It was on one of those occasional sunshiny days in the early part of October[379] when we first visited Ay--the vineyard of 'golden plants,' the unique _premier cru_ of the Wines of the River--and the various adjacent vinelands. The road lay between two rows of closely-planted poplar-trees reaching almost to the village of Dizy, whose quaint gray church-tower, with its gabled roof, is dominated by the neighbouring vine-clad slopes, which extend from Avenay to Venteuil, some few miles beyond Hautvillers, the cradle, so to speak, of the _vin mousseux_ of the Champagne. The vineyards of Dizy, the upper soil of which is largely mixed with loose stones, have chiefly a southern or western aspect, and, excepting in the case of the precipitous height suggestively styled 'Grimpe Chat,' their incline is generally a gentle one. In these vineyards, which rank among the _premiers crus_ of the Champagne, a quantity of wine from white grapes is regularly made. From Dizy the road runs immediately at the base of vine-clad slopes, broken up occasionally by a conical peak detaching itself from the mass, and tinted from base to summit with richly-variegated hues, among which deep purple, yellow, green, gray, and crimson by turns predominate. On our right hand we pass a vineyard called Le Léon, which tradition asserts to be the one whence Pope Leo the Magnificent, the patron of Michael Angelo, Raffaelle, and Da Vinci, drew his supply of Ay wine. The village of Ay lies immediately before us at the foot of the slopes of vines, with the tapering spire of its ancient church rising above the neighbouring hills and cutting sharply against the bright blue sky. The vineyards, which spread themselves over a calcareous declivity, have mostly a full southern aspect, and the predominating vines are those known as golden plants, the fruit of which is of a deep purple colour. After these comes the _plant vert doré_, and then a moderate proportion of the _plant gris_, white varieties of grapes being no longer cultivated as formerly.[380] [Illustration: DIZY AND ITS VINEYARD SLOPES.] The Ay vineyards are mentioned in a charter of Edmund of Lancaster, son of our Henry II. and guardian of Jehanne, heiress of Henri le Gros, Count of Champagne, dated 1276, and confirming the right of the Abbey of Avenay to four hogsheads of wine from the _terroir_ of Ay.[381] If faith, however, may be placed in monkish legends, their existence dates back to the sixth century, at which epoch St. Tresain, the patron saint of Avenay and a contemporary of St. Remi, emigrated to the Champagne from Scotland. Having given away all he possessed in charity, he became perforce a swineherd at Mutigny, a village on the summit of the hill overlooking Ay, Mareuil, and Avenay. One day the vine-growers of Ay, hearing that St. Remi was at Ville-en-Selve, sought him out, and clamorously accused St. Tresain of neglecting to look after his pigs, which had devastated the vineyards on the slopes, and so caused great loss to the community. When called upon for his defence, St. Tresain acknowledged that he was wont to listen in the church-porch to the celebration of mass, and to forget on these occasions all such sublunary matters as swine. St. Remi, finding him so deeply religious, not only forgave him his negligence and relieved him from his porcine charge for the future, but appointed him parish priest of Mareuil and Mutigny, the inhabitants of which, it is to be hoped, received more attention from him than his pigs had done. St. Tresain, although his promotion was brought about by the complaint of the men of Ay, retorted on the latter in a vindictive and unsaintly spirit, for he ill-naturedly cursed them, and declared that after thirty years of age not one of them or their posterity should prosper temporally or spiritually--a prophecy which, if it affected the vine-growers of that epoch, has proved harmless enough in the case of their descendants.[382] At Ay we visited the pressoir of the principal producer of _vin brut_, who, although the owner of merely five hectares, or about twelve and a half acres of vines, expected to make as many as 1500 pièces of wine that year, mainly of course from grapes purchased from other growers.[383] On our way from Ay to Mareuil, along the lengthy Rue de Châlons, we looked in at the little auberge at the corner of the Boulevard du Sud, and found a crowd of coopers and others connected in some way with the vintage, taking their cheerful glasses round. The walls of the room were appropriately enough decorated with capering bacchanals squeezing bunches of purple grapes and flourishing their thyrsi about in a very tipsy fashion. All the talk--and there was an abundance of it--had reference to the yield of this particular vintage and the high rate the Ay wine had realised. Eight hundred francs the pièce of 200 litres, equal to 44 gallons, appeared to be the price fixed by the agents of the great Champagne houses, and at this figure the bulk of the vintage was disposed of before a single grape passed through the winepress.[384] [Illustration] The Mareuil vinelands, which include the vineyard bequeathed some six hundred years ago by Canon John de Brie to the chapter of Reims cathedral, and possibly those vineyards bestowed in 1208 on the Abbey of Avenay by Alain de Jouvincourt, cover the slopes of two coteaux, the first a continuation of the Côte d'Ay, and the second a detached spur, known as the Mont de Fourche, overlooking the Marne canal. Owing to the steepness of the slopes and to the roads through the vineyards being impracticable for carts, the grapes were being conveyed to the press-houses in baskets slung across the backs of mules and donkeys, most of which, on account of their known partiality for the ripe fruit, were muzzled while thus employed. The wine yielded by the Mareuil vineyards possesses body and vinosity, and while of course regarded as inferior to that of Ay, found a ready market the year of our visit at from five to six hundred francs the pièce. Prior to the French Revolution, the produce of the winepresses of the Seigneurs of Mareuil and the Abbess of Avenay were almost as renowned as the best growths of Ay. The reputation of the wine was then shared by the inhabitants of the village; the popular local diction, 'Les gens d'Ay, les messieurs de Mareuil, et les crottés d'Avenay,' referring to the days when the first was inhabited by enriched wine-growers, the second by people of some position, and the third merely by peasants, simply from its being cut off, in a great measure, from outside intercourse through the badness of its approaches. It was not until after 1776, when the _seigneurie_ of Louvois was purchased from the Marquis de Souvré by Madame Adelaïde, aunt of Louis XVI., that the road from Epernay to Louvois, which passes through Mareuil and Avenay, was, if not constructed, at any rate rendered practicable, in order to facilitate the visits of the princess to her new acquisition. These roads exist, though no traces remain of the ancient fort of Mareuil on the bank of the Marne, taken from the English in 1359 by Gaucher de Chatillon, captain of Reims, and alternately occupied by Leaguers and Royalists during the War of Religion in the sixteenth century. Nor does there seem any chance of identifying either the 'vineyard called la Gibaudelle, lying next the vineyard of Oudet, surnamed Leclerc,' in the territory of Mareuil, which Guillaume de Lafors and Marguerite his wife bestowed upon the Abbey of Avenay in 1273, or those from which, in the fourteenth century, Archbishop Richard Pique of Reims used to draw ten muids or hogsheads of wine annually for 'droits de vinage.' [Illustration: AVENAY AS SEEN FROM THE RAILWAY.] The vineyards of Avenay also date prior to the thirteenth century, mention being frequently made of them in the charters of that epoch.[385] Their best wine, which Saint Evremond extolled so highly, is vintaged to-day up the slopes of Mont Hurlé. Avenay itself is a tumbledown little village situated in the direction of Reims, and the year of our visit we found the yield from its vineyards had been scarcely more than the third of an average one, and that the wine produced at the first pressure of the grapes had been sold for 500 francs the pièce. We tasted there some very fair still red wine, made from the same grapes as Champagne, remarkably deep in colour, full of body, and possessing that slight sweet bitterish flavour which characterises certain of the better-class growths of the South of France. Although at Avenay vineyards cover the slopes as of yore, when Marmontel used to wander amongst them in company with his inamorata Mademoiselle Hévin de Navarre, no traces remain of the ancient royal abbey--founded by St. Bertha in 660, on the martyrdom of her husband, St. Gombert, one of the early Christian missionaries to Scotland--where Charles V. took up his quarters when invading Champagne in 1544, and where the deputies of the Leaguers of Reims and of the Royalists of Châlons met in October 1592 to settle the terms of the 'Traité des Vendanges,' securing to both parties liberty to gather in the vintage unmolested.[386] The villagers still point out the house where Henri Quatre slept, and the window from which he harangued the populace during the visit paid by him to Madame Françoise de la Marck, the Abbess of Avenay,[387] in August of the same year. This, by the way, does not seem to have been the only occasion when the spot was honoured by the presence of Royalty; for a tradition, which, although unsupported by any documentary evidence, appears to be worthy of credence, is current to the effect that Marie Antoinette paid a visit to the Abbey of Avenay during her sojourn at Louvois as the guest of Madame Adelaïde in 1786. The spring which, according to the legend, gushed forth when St. Bertha, in imitation of Moses, struck the rock with her distaff, is still shown to travellers; and scandal has gone so far as to say that recourse is sometimes had to it to eke out the native vintage. On leaving Avenay we ascended the hills to Mutigny, and wound round thence to Cumières, on the banks of the Marne, finding the vintage in full operation all throughout the route. The vineyards of Cumières--classed as a second cru--yield a wine which, though celebrated in the verses of Eustache Deschamps, a famous and prolific Champenois poet of the fourteenth century, varies to-day considerably in quality, the best coming from the 'Côtes-à-bras,' the property of the Abbey of Hautvillers in Dom Perignon's day. The Cumières vineyards join those of Hautvillers on the one side and Damery on the other, the latter a cosy little river-side village, where the _bon Roi Henri_ sought relaxation from the turmoils of war in the society of the fair Anne du Pay, _sa belle hôtesse_, as the gallant Béarnais was wont to style her. Damery also claims to be the birthplace of Adrienne Lecouvreur, the celebrated actress of the Regency, and mistress of the Maréchal de Saxe, who coaxed her out of her 30,000_l._ of savings to enable him to prosecute his suit with the obese Anna Iwanowna, niece of Peter the Great, which, had he only been successful, would have secured the future hero of Fontenoy the coveted dukedom of Courland. From Cumières can be distinguished far away on the horizon the ruined tower of the _bourg_ of Châtillon, the birthplace of Pope Urban II., preacher of the first Crusade, and a devotee of the wine of Ay.[388] It was during the budding spring-time when we made our formal pilgrimage to Hautvillers across the swollen waters of the Marne at Epernay. Our way lay for a time along a straight level poplar-bordered road, with verdant meadows on either hand; then diverged sharply to the left, and we commenced ascending the vine-clad hills, on a narrow plateau of which the church and abbey remains are picturesquely perched. The closely-planted vines extend along the undulating slopes to the summit of the plateau, and wooded heights rise up beyond, affording shelter from the bleak winds that sweep over here from the north. Spite of the reputation which the wine of Hautvillers enjoyed a couple of centuries ago, and its association with the origin of _vin mousseux_, the vineyards to-day appear to have been relegated to the rank of a second cru, their produce ordinarily commanding less than two-thirds of the price obtained for the Ay and Verzenay growths.[389] The church of Hautvillers and the remains of the abbey are situated at the farther extremity of the village, at the end of its one long street, named, pertinently enough, the Rue de Bacchus. Time, the iconoclasts of the great Revolution, and the quieter, yet far more destructive, labours of the Bande Noire, have spared but little of the royal abbey of St. Peter, where Dom Perignon lighted upon his happy discovery of the effervescent quality of Champagne. The quaint old church, scraps of which date back to the twelfth century, the remnants of the cloisters, and one of the abbey's ancient gateways, are all that remain to testify to the grandeur of its past, when it was the proud boast of the brotherhood that it had given nine archbishops to the see of Reims, and two-and-twenty abbots to various celebrated monasteries. [Illustration: FOUNTAIN AT A CAFÉ IN THE RUE DE BACCHUS, HAUTVILLERS.] Passing through an unpretentious gateway, we find ourselves in a spacious courtyard, bounded by buildings somewhat complex in character. On our right rises the tower of the church with the remains of the old cloisters, now walled-in and lighted by small square windows, and propped up by heavy buttresses. To the left stands the residence of the bailiff, and beyond it an eighteenth-century château on the site of the abbot's house. Formerly the abbey precincts were bounded on this side by a picturesque gateway-tower leading to the vineyards, and known as the 'Porte des Pressoirs,' from its contiguity to the winepresses. The court is enclosed on its remaining sides by huge barn-like buildings, stables, and cart-sheds; while roaming about are numerous live stock, indicating that what remains of the once-famous royal abbey of St. Peter has degenerated into an ordinary farm. To-day the abbey buildings and certain of its lands are the property of M. Paul Chandon de Brialles, of the firm of Moët & Chandon, the great Champagne manufacturers of Epernay, who maintains them as a farm, keeping some six-and-thirty cows there, with the object of securing the necessary manure for the numerous vineyards which the firm own hereabouts. [Illustration: THE PORTE DES PRESSOIRS, ABBEY OF HAUTVILLERS (Destroyed by fire in 1879).] [Illustration: REMAINS OF CLOISTERS, ABBEY OF HAUTVILLERS.] The dilapidated cloisters, littered with old casks, farm implements, and the like, preserve ample traces of their former architectural character, changed as they are since the days when the sandalled feet of the worthy cellarer resounded through the echoing arches as he paced to and fro, meditating upon coming vintages and future marryings of wines. Vine-leaves and bunches of grapes decorate some of the more ancient columns inside the church, and grotesque mediæval monsters, such as monkish architects habitually delighted in, entwine themselves around the capitals of others. The stalls of the choir are elaborately carved with cherubs' heads, medallions and figures of saints, cupids supporting shields, and free and graceful arabesques of the epoch of the Renaissance. In the chancel, close by the altar-steps, are a couple of black-marble slabs, with Latin inscriptions of dubious orthography, the one to Johannes Royer, who died in 1527, and the other, which has been already cited in detail, setting forth the virtues and merits of Dom Petrus Perignon, the discoverer of the effervescing qualities of Champagne. In the central aisle a similar slab marks the resting-place of Dom Thedoricus Ruynart--obit 1709--an ancestor of the Reims Ruinarts; and little square stones interspersed among the tiles with which the side aisles of the church are paved record the deaths of other members of the Benedictine brotherhood during the seventeenth and eighteenth centuries. Several large pictures grace the walls of the church, the most interesting one representing St. Nivard, Bishop of Reims, and his friend, St. Berchier, designating to some mediæval architect the site which the contemplated Abbey of St. Peter is to occupy, as set forth in the legend already related. [Illustration: FROM THE ABBEY CHURCH, HAUTVILLERS.] [Illustration: FROM THE ABBEY CHURCH, HAUTVILLERS.] At a short distance from the abbey farm, Messrs. Moët & Chandon have erected a tower, whence a splendid view, extending over the vineyards of Cumières, Hautvillers, Dizy, and Ay, with those lying on the opposite bank of the river, is to be obtained. Gazing from here, it is easy to imagine the scene presented in the days when the Abbey of St. Peter still reared its stately walls, when Louis Chaumejan de Tourille wore the abbatial insignia, and Dom Perignon displayed with equal pride as the badge of his office the key of the abbey cellars. Over these slopes on a dewy autumn morning the latter's eyes, ere sealed in blindness, must have often wandered, and an unctuous chuckle must have welled up from between his lips as he marked the grapes steadily advancing towards maturity. We can fancy him pausing from time to time 'To breathe an ejaculatory prayer And a benediction on the vines,' although in those halcyon days there was neither oïdium nor phylloxera to be dreaded, and an extra taper or so to St. Vincent, the patron of vine-dressers, sufficed to secure the crop from ordinary accidents of flood and field. When the epoch of the vintage arrived, and the slopes were all alive with bands of vintagers engaged in stripping the ripened purple bunches from the vines, and carefully transporting them to the winepress, one can picture Dom Perignon smiling contentedly at the report of the gray-haired bailiff that no such crop had been garnered for years before. And when the must began to gush forth as the stalwart bare-armed peasants tugged at the levers of the huge press on which M. de Tourille had placed the glorifying inscription elsewhere cited, with what satisfaction must Perignon have recognised a foreshadowing of that divine aroma which lends so exquisite a charm to the choice vintages of the Champagne! Later on we can imagine him entering the abbey cellar, stored with the results of his careful labours, as a 'sacred place, With a thoughtful, solemn, and reverent pace,' and softly chanting to himself, as he draws off a flagon of the best and choicest vintage which the gloomy vaults contain: 'Ah, how the streamlet laughs and sings! What a delicious fragrance springs From the deep flagon as it fills, As of hyacinths and daffodils!' The vineyards of the Côte d'Epernay, on the southern bank of the Marne, extend eastward from beyond Boursault, on whose wooded height stands the fine château built by Madame Clicquot, and in which her granddaughter, the Comtesse de Mortemart, to-day resides. They then follow the course of the river, and, after winding round behind Epernay, diverge towards the south-west. Amongst them are the slopes of Pierry, Mardeuil, Moussy, Vinay, Ablois, and Chouilly, the last named situate somewhat apart from the rest to the east of Epernay, and yielding a light wine, qualified as slightly purgative. The vines of the Côte d'Epernay produce only black grapes, and many of the vineyards are of great antiquity, the one known as the Closet, near Epernay, having been bequeathed under that name by a canon of Laon named Parchasius to the neighbouring Abbey of St. Martin six and a half centuries ago. [Illustration: THE VILLAGE OF PIERRY.] [Illustration: VINEYARD WINE-CELLARS AT PIERRY.] A short drive along the high-road leading from Epernay to Orleans brings us to the village of Pierry, cosily nestling amongst groves of poplars in the valley of the Cubry, with some half-score of châteaux of the last century, belonging to well-to-do wine-growers of the neighbourhood, screened from the road by umbrageous gardens. Vines mount the slopes that rise around, the higher summits being crowned with forest, while here and there some pleasant village shelters itself under the brow of a lofty hill. Near Pierry many cellars have been excavated in the chalky soil, to the flints so prevalent in which the village is said to owe its name. The entrances to these cellars are closed by iron gateways, and on the skirts of the vineyards we come upon whole rows of them picturesquely overgrown with ivy, and suggestive in appearance of catacombs. Early in the last century the wine vintaged here in the Clos St. Pierre, belonging to an abbey of this name at Châlons, acquired a high reputation through the care bestowed upon it by Brother Jean Oudart, whose renown almost rivalled that of Dom Perignon himself; and to-day the Pierry vineyards, producing exclusively black grapes, hold a high rank among the second-class crus of the Marne.[390] Crossing the Sourdon, a little stream which, after bubbling up in the midst of huge rocks in the forest of Epernay, rushes down the hills, and then changes its name to the Cubry, we soon reach Moussy, where vineyards have been in existence for something like eight centuries; for we find enumerated in the list of bequests made to the hospital of St. Mary at Reims in the eleventh and twelfth centuries sundry 'vineas in Moiseio' devised by such long-forgotten notabilities as Pontius, priest and canon, Tebaldus Papilenticus, Johannes de Germania, and Macela, wife of Pepinus. Spite, however, of their long pedigree and advantageous southern aspect, the Moussy vineyards rank to-day merely as a second cru. Continuing to skirt the vine-clad slopes we come to Vinay, noted for an ancient grotto[391]--the former comfortless abode of some rheumatic anchorite--and a pretended miraculous spring to which fever-stricken pilgrims to-day credulously resort. The water may possibly merit its renown; but the wine here produced is very inferior, due no doubt to the class of vines, the meunier being the leading variety cultivated. At Ablois St. Martin, once a fief of Mary Queen of Scots, and picturesquely perched partway up a slope in the midst of hills covered with vines and crowned with forest trees, the Côte d'Epernay ends, and the produce becomes of a choicer character. As the Côte d'Avize lies to the south-east, to reach it we have to retrace our steps to Pierry, and follow the road which there branches off, leaving on our right hand the vineyards of Chavot, Monthelon, and Grauves, now of no particular note, although of undoubted antiquity, Blanche of Castille, Countess of Champagne, having endowed the Abbey of Argensolles, on its foundation in 1224, with sundry strips of vineland, including one at Grauves, possibly the vineyard of Les Roualles, which yields a wine not unlike certain growths of the Mountain of Reims. After passing through Cuis, where the slopes, planted with both black and white varieties of vines, are extremely abrupt, and where Simon la Bole, man-at-arms of Epernay, and his wife Basile gave, in 1210, 'four hogsheads of _vinage_ to be taken annually' to Hugo, Abbot of St. Martin at Epernay, we eventually reach Cramant, one of the grand _premiers crus_ of the Champagne. From the vineyards around this picturesque little village, and extending along the somewhat precipitous Côte de Saran--a prominent object, on which is M. Moët's handsome château--there is vintaged a wine from white grapes, especially remarkable for lightness and delicacy and the richness of its bouquet, and an admixture of which is essential to every first-class Champagne _cuvée_. From Cramant the road runs direct to Avize, a large thriving village, lying at the foot of vineyard slopes, where numerous Champagne firms have established themselves. Its prosperity dates from the commencement of the last century (1715), when the Count de Lhery, its feudal lord, cleared away the remains of its ancient ramparts, filled up the moat, and planted the ground with vines, the produce of which proved admirably suited for the sparkling wines then coming into vogue. Prior to this the Avize wine, made almost entirely from white grapes, fetched only from 25 to 30 francs the queue; but being found well adapted for the manufacture of the strongly-effervescent wine known as _saute-bouchon_, it soon commanded as much as 300 francs, and the arpent of vineyard rose in value from 250 to 2000 francs.[392] To-day the light delicate wine of Avize is classed, like that of Cramant, as a _premier cru_, and it is the same with the wine of Oger,[393] lying a little to the south, while the neighbouring growths of Le Mesnil hold a slightly inferior rank. The latter village and its gray Gothic church lie under the hill in the midst of vines that almost climb the forest-crowned summit. The stony soil hereabouts is said to be better adapted to the cultivation of white than of black grapes; besides which, the wines of Le Mesnil are remarkable for their effervescent properties. [Illustration: LE MESNIL AND ITS VINEYARDS.] [Illustration: VIEW OF VERTUS.] Vertus forms the southern limit of the Côte d'Avize, and the vineyard slopes subsiding at their base into a broad expanse of fertile fields, and crested as usual with dense forest, rise up behind the picturesque old town, which is mentioned in a letter of the Emperor Louis and a charter of Charles the Bald in the ninth century. It was once strongly fortified, though a dilapidated gateway is all that to-day remains of the ancient ramparts, which failed to secure it in 1380, when the English, under the 'Comte de Bouquingouan,' presumably Buckingham, burnt the whole of the town except the Abbey of St. Martin, and elicited from the native poet, Eustache Deschamps, _dit_ Morel, 'huissier d'armes' to Charles VI. and castellan of Fismes, a lamentation, wherein he fails not to mention the high renown of the local vintage.[394] [Illustration: OLD HOUSES AT VERTUS.] Vertus can still boast a curious old church of the eleventh century, with solid Romanesque towers, elaborate mouldings, and richly ornamented capitals; also a picturesque promenade, shaded with centenarian trees, together with several quaint old houses, including one with a florid Gothic window surrounded by a border of grapes and vine-leaves, and another with a quaintly projecting corner turret, dominated by a conical roof. The Vertus vineyards are mentioned in a charter of the Abbey of Ste. Marie, dated 1151. They were originally planted with vines from Beaune in Burgundy, and in the fourteenth century yielded a red wine held in high repute, of pleasant flavour, and rich in perfume,[395] but which would appear to have been imbued with those purgative properties[396] traceable in other growths of the Champagne. The red wine of Vertus formed the favourite beverage of William III. of England, and was long in high repute. To-day, however, the growers find it more profitable to make white instead of red wine from their crops of black grapes, the former commanding a good price for conversion into _vin mousseux_, from being in the opinion of some manufacturers especially valuable for binding a _cuvée_ together. The Vertus growths rank among the second-class Champagne crus.[397] [Illustration: SILLERY AND ITS VINEYARDS.] II. /The Champagne Vinelands--The Vineyards of the Mountain./ The wine of Sillery--Origin of its renown--The Maréchale d'Estrées a successful Marchande de Vin--The Marquis de Sillery the greatest wine-farmer in the Champagne--Cossack appreciation of the Sillery produce--The route from Reims to Sillery--Henri Quatre and the Taissy wines--Failure of the Jacquesson system of vine cultivation--Château of Sillery--Wine-making at M. Fortel's--Sillery sec--The vintage at Verzenay and the vendangeoirs--Renown of the Verzenay wine--The Verzy vineyards--Edward III. at the Abbey of St. Basle--Excursion from Reims to Bouzy--The herring procession at St. Remi--Rilly, Chigny, and Ludes--The Knights Templars' 'pot' of wine--Mailly and the view over the Champagne plains--Wine-making at Mailly--The village in the wood--Château and park of Louvois, Louis le Grand's War Minister--The vineyards of Bouzy--Its church-steeple, and the lottery of the great gold ingot--Pressing grapes at the Werlé vendangeoir--Still red Bouzy--Ambonnay--A pattern peasant vine-proprietor--The Ambonnay vintage--The vineyards of Ville-Dommange and Sacy, Hermonville and St. Thierry--The still red wine of the latter. [Illustration: TOWER AND GATEWAY OF THE CHÂTEAU DE SILLERY.] The vineyards of the Mountain of Reims may be divided into two zones, one of which, known as the Basse Montagne, is situate north-west of Reims, and comprises the vineyards of St. Thierry, Marsilly, Hermonville, and others; whilst the more important zone lies to the south of the old cathedral city, and includes the better-known crus of Sillery, Verzy, Verzenay, Mailly, Ludes, Chigny, and Rilly. The vinelands of Bouzy and Ambonnay are also reckoned within it, though situate somewhat apart on a southern slope of the Mountain some few miles from the Marne. The smallest of the Champagne vineyards are those of Sillery, and yet no wine of the Marne enjoys a greater renown, due originally to the intelligence and energy of the family of the Brularts, Marquises of Sillery and Puisieux, to whom the estate originally belonged, and who seem to have devoted great attention to viticulture from certainly the middle of the seventeenth century. The reputation of the still wine of Sillery, 'the highest manifestation of the divinity of Bacchus in all France,' was firmly established at this epoch. 'As to M. de Puyzieux,' writes St. Evremond to his friend Lord Galloway in August 1701, 'he acts wisely to fall in with the bad taste now in fashion concerning Champagne in order to sell his own the better;' but at the same time he counsels his correspondent to get the marquis to make him 'a little barrel after the fashion in which it was made forty years before, prior to the existing depravation of taste.'[398] The marquis here referred to was Roger Brulart, Governor of Epernay, who was himself a joyous _bon vivant_, and died from over-indulgence in the good things provided at a dinner given by the Chartreux in 1719.[399] He was succeeded by his nephew, Louis Philogène Brulart, Marquis de Sillery et de Puisieux, to whom, in 1727, on the occasion of his marriage with Mademoiselle de Souvré, granddaughter of Louvois, the Sieurs Quatresous and Chertemps presented at his château of Sillery, on behalf of the town of Epernay, a basket of one hundred flasks of wine.[400] He died in 1771, leaving an only daughter, Adelaïde Félicité Brulart de Sillery, married, in 1744, to Louis César le Tellier, Maréchal Duc d'Estrées. The wine attained its apogee under the fostering care of the Maréchale d'Estrées, to whom not only this cru, but those of Mailly, Verzy, and Verzenay belonged, and who concentrated their joint produce in the capacious cellars of her château, afterwards sending it forth with her own guarantee, under the general name of Sillery, which, like Aaron's serpent, thus swallowed up the others. The Maréchale's social position enabled her to secure for her wines the recognition they really merited, being made with the utmost care and a rare intelligence, shown by the removal of every unripe, rotten, or imperfect grape from the bunches before pressing, so that the _Vin de la Maréchale_, as it was styled, became famous throughout Europe.[401] This lady is not to be confounded with that other Maréchale d'Estrées mentioned by St. Simon, noted for her exquisite and magnificent although rare entertainments, and so sordid that when her daughter, who was covered with jewels, fell down at a ball, her first cry was, not like Shylock's, 'My daughter!' but 'My diamonds!' as, rushing forward, she strove to pick up, not the fallen dancer, but her scattered gems. Later owners of the famous Sillery cru did their best to sustain its reputation, and Arthur Young, who stopped here in 1787, speaks of the Marquis de Sillery as 'the greatest wine-farmer in the Champagne,' having on his own hands 180 arpents of vines, and cellar-room for a couple of hundred pièces of wine.[402] Among more recent appreciation of the merits of Sillery sec may be mentioned the Cossacks, who pillaged the district in 1814, and who, not being able to carry off all the wine from the cellar of the Count de Valence at Sillery, stove in some thirty pièces of the best, and set the place afloat.[403] The drive from Reims to Sillery has nothing attractive about it. A long, straight, level road bordered by trees intersects a broad tract of open country, skirted on the right by the Petite Montagne of Reims, with antiquated villages nestled among the dense woodland. After crossing the Châlons line of railway--near where one of the new forts constructed for the defence of Reims rises up behind the villages and vineyards of Cernay and Nogent l'Abbesse--the country becomes more undulating. Poplars border the broad Marne canal, and a low fringe of foliage marks the course of the languid river Vesle, on the banks of which is Taissy, famous in the old days for its wines, great favourites with Sully, and which almost lured Henri Quatre from his allegiance to the vintages of Ay and Arbois that he loved so well.[404] To the left rises Mont de la Pompelle, where the first Christians of Reims suffered martyrdom, and where, in 1658, the Spaniards under Montal, when attempting to ravage the vineyards of the district, were repulsed with terrible slaughter by the Rémois militia, led on by Grandpré. A quarter of a century ago the low ground on our right near Sillery was planted with vines by the late M. Jacquesson, the then owner of the Sillery estate, and a large Champagne manufacturer at Châlons, who was anxious to resuscitate the ancient reputation of the domain. Under the advice of Dr. Guyot, the well-known writer on viticulture, he planted the vines in deep trenches, which led to the vineyards being punningly termed Jacquesson's _celery_ beds. To shield the vines from hailstorms prevalent in the district, and the more dangerous spring frosts, so fatal to vines planted in low-lying situations, long rolls of straw-matting were stored close at hand with which to roof them over when needful. These precautions were scarcely needed, however; the vines languished through moisture at the roots, and eventually were mostly rooted up. [Illustration: HENRI QUATRE.] [Illustration: CHÂTEAU DE SILLERY.] After again crossing the railway we pass the trim restored turrets of the famous château of Sillery, with its gateways, moats, and drawbridges, flanked by trees and floral _parterres_. It was here that the stout squire Laurent Pichiet kept watch and ward over the 'forte maison de Sillery' on behalf of the Archbishop of Reims at the close of the fourteenth century, that the Maréchale d'Estrées carried on her successful business as a _marchande de vins_, and that the pragmatic and pedantic Comtesse de Genlis, governess of the Orleans princes, spent, as she tells us, the happiest days of her life. The few thriving vineyards of Sillery cover a gentle eminence which rises out of the plain, and present on the one side an eastern and on the other a western aspect. They have fallen somewhat from their high estate since the days when old Coffin of Beauvais University sang their praises in Latin: 'Let Horace the charms of old Massica own, And the praise of Falernian sound; Such wines, although famous, must bow to that grown On Sillery's fortunate ground.'[405] To-day the Vicomte de Brimont and M. Fortel of Reims, the latter of whom cultivates some forty acres of vines, yielding ordinarily about 300 hogsheads, are the only wine-growers at Sillery. Before pressing his grapes--of course for sparkling wine--M. Fortel has them thrown into a trough, at the bottom of which are a couple of grooved cylinders, each about eight inches in diameter, and revolving in contrary directions, the effect of which, when set in motion, is to disengage the grapes partially from their stalks. Grapes and stalks are then placed under the press, which is on the old cider-press principle, and the must runs into a reservoir beneath, whence it is pumped into large vats, each holding from 250 to 500 gallons. Here it remains from six to eight hours, and is then run off into casks, the spigots of which are merely laid lightly over the holes, and in the course of twelve days the wine begins to ferment. It now rests until the end of the year, when it is drawn off into new casks and delivered to the buyer, invariably one or other of the great Champagne houses, who willingly pay an exceptionally high price for it. The second and third pressures of the grapes yield an inferior wine, and from the husks and stalks _eau-de-vie_, worth about five shillings a gallon, is distilled. The wine known as Sillery sec is a full, dry, pleasant-flavoured, and somewhat spirituous amber-coloured wine. Very little of it is made nowadays, and most that is comes from the adjacent vineyards of Verzenay and Mailly, and is principally reserved by the growers for their own consumption. One of these candidly admitted that the old reputation of the wine had exploded, and that better white Bordeaux and Burgundy wines were to be obtained for less money. In making dry Sillery, which locally is esteemed as a valuable tonic, it is essential that the grapes should be subjected to only slight pressure; while to have it in perfection it is equally essential that the wine should be kept for ten years in the wood according to some, and eight years in bottle according to others, to which circumstance its high price is in all probability to be attributed. In course of time it forms a deposit, and has the disadvantage common to all the finer still wines of the Champagne district of not travelling well. Beyond Sillery the vineyards of Verzenay unfold themselves, spreading over the extensive slopes and stretching to the summit of the steep height to the right, where a windmill or two are perched. Everywhere the vintagers are busy detaching the grapes with their little hook-shaped _serpettes_, the women all wearing projecting close-fitting bonnets, as though needlessly careful of their anything but blonde complexions. Long carts laden with baskets of grapes block the narrow roads, and donkeys, duly muzzled, with panniers slung across their backs, toil up and down the steeper slopes. Half-way up the principal hill, backed by a dense wood and furrowed with deep trenches, whence soil has been removed for manuring the vineyards, is the village of Verzenay--where in the Middle Ages the Archbishop of Reims had a fief--overlooking a veritable sea of vines. Rising up in front of the old gray cottages, encompassed by orchards or gardens, are the white walls and long red roofs of the vendangeoirs belonging to the great Champagne houses--Moët & Chandon, Clicquot, G. H. Mumm, Roederer, Deutz & Geldermann, and others--all teeming with bustle and excitement, and with the vines almost reaching to their very doors. Messrs. Moët & Chandon have as many as eight presses in full work, and own no less than 120 acres of vines on the neighbouring slopes, besides the Clos de Romont--in the direction of Sillery, and yielding a wine of the Sillery type--belonging to M. Raoul Chandon. Verzenay ranks as a _premier cru_, and for three years in succession--1872, 3, and 4--its wines fetched a higher price than either those of Ay or Bouzy. In 1873 the _vin brut_ commanded the exceptionally large sum of 1050 francs the hogshead of 44 gallons. All the inhabitants of Verzenay are vine-proprietors, and several million francs are annually received by them for the produce of their vineyards from the manufacturers of Champagne. The wine of Verzenay, remarkable for its body and vinosity, has always been held in high repute,[406] which is apparently more than can be said of the probity of the inhabitants, for, according to an old Champagne saying, 'Whenever at Verzenay "Stop thief" is cried every one takes to his heels.' [Illustration: THE VINEYARDS OF VERZENAY.] [Illustration: DEVICE ABOVE ENTRANCE TO VENDANGEOIR AT VERZENAY.] Just over the Mountain of Reims is the village of Verzy, the vine-growers of which distinguished themselves in the fifteenth century by their resistance to the officials sent to levy the 'aide en gros' of two sols per queue, imposed by Louis XI. on all wine made within a radius of four miles of Reims. The Verzy vineyards--ranked to-day as a second cru--date at least from the days of the Knights Templars, when the Commanderie of Reims had 'two vineyards near the abbey' here. They adjoin those of Verzenay, and are almost exclusively planted with white grapes, the only instance of the kind to be met with in the district. In the Clos St. Basse, however--taking its name from the Abbey of St. Basle, of which the village was a dependency, and where Edward III. of England had his head-quarters during the siege of Reims--black grapes alone are grown, and its produce is almost on a par with the wines of Verzenay. Immediately prior to the Revolution, one-fourth of the inhabitants of Verzy were landholders, each cultivating about five arpents of vines, and obtaining therefrom, on an average, twenty poinçons, out of which the abbey exacted one and three-quarters for 'droits de dimes et de banalité de pressoir.' Southwards of Verzy are the third-class crus of Villers-Marmery and Trépail, the former of which was of some repute in the Middle Ages. [Illustration: PORTION OF FRIEZE OF OLD HOUSE, RUE DU BARBATRE, REIMS.] We made several excursions to the vineyards of Bouzy, driving out of Reims along the ancient Rue du Barbâtre and past the quaint old church of St. Remi, one of the sights of the Champagne capital, and notable, among other things, for its magnificent ancient stained-glass windows, and the handsome modern tomb of the popular Rémois saint. It was here in the Middle Ages that that piece of priestly mummery, the procession of the herrings, used to take place at dusk on the Wednesday before Easter. Preceded by a cross, the canons of the church marched in double file up the aisles, each trailing a cord after him, with a herring attached. Every one's object was to tread on the herring in front of him, and prevent his own herring from being trodden upon by the canon who followed behind--a difficult enough proceeding, which, if it did not edify, certainly afforded much amusement to the lookers-on. [Illustration: ANCIENT WELL, RUE DU BARBATRE, REIMS.] After crossing the canal and the river Vesle, and leaving the gray antiquated-looking village of Cormontreuil on our left, we traversed a wide stretch of cultivated country streaked with patches of woodland, with occasional windmills dotting the distant heights, and villages nestling among the trees up the mountain-sides and in the quiet hollows. Soon a few vineyards occupying the lower slopes, and thronged by bands of vintagers, came in sight, and the country too grew more picturesque. We passed successively on our right hand Rilly, a former fief of the Archbishop of Reims, and noted for its capital red wine; then Chigny, where the Abbot of St. Remi had a vineyard as early as the commencement of the thirteenth century; and afterwards Ludes,--all three of them situated more or less up the mountain, with vines in every direction, relieved by a dark background of forest-trees. In the old days, the Knights Templars of the Commanderie of Reims had the right of _vinage_ at Ludes, and exacted their modest 'pot' (about half a gallon) per pièce on all the wine the village produced. On our left hand is Mailly, the vineyards of which join those of Verzenay, and, though classed only as a second cru, yielding a wine noted for _finesse_ and bouquet, identified by some as the vintage which was recommended in the ninth century to Bishop Hincmar of Reims by his _confrère_, Pardulus of Laon. From the wooded knolls hereabouts a view is gained of the broad plains of the Champagne, dotted with white villages and scattered homesteads among the poplars and the limes, the winding Vesle glittering in the sunlight, and the dark towers of Notre Dame de Reims, with all their rich Gothic fretwork, rising majestically above the distant city. At one vendangeoir we visited, at Mailly, between 350 and 400 pièces of wine were being made at the rate of some thirty pièces during the long day of twenty hours, five men being engaged in working the old-fashioned press, closely resembling a cider-press, and applying its pressure longitudinally. This ancient press doubtless differs but little from the one which the chapter of Reims Cathedral possessed at Mailly in 1384. As soon as the must was expressed it was emptied into large vats, holding about 450 gallons, and in these it remained for several days before being drawn off into casks. Of the above thirty pièces, twenty resulting from the first pressure were of the finest quality, while four produced by the second pressure were partly reserved to replace what the first might lose during fermentation, the residue serving for second-class Champagne. The six pièces which came from the final pressure, after being mixed with common wine of the district, were converted into Champagne of an inferior quality. [Illustration: THE VINEYARDS OF BOUZY.] We now crossed the mountain, sighting Ville-en-Selve--the village in the wood--among the distant trees, and eventually reached Louvois, whence the Grand Monarque's domineering war minister derived his marquisate, and where his château, a plain but capacious edifice, may still be seen nestled in a picturesque and fertile valley, and surrounded by lordly pleasure-grounds. Château and park are to-day the property of M. Frédéric Chandon, who has bestowed much care on the restoration of the former. Soon after we left Louvois the vineyards of Bouzy appeared in sight, with the prosperous-looking little village rising out of the plain at the foot of the vine-clad slopes stretching to Ambonnay, and the glittering Marne streaking the hazy distance. The commodious new church is said to have been indebted for its spire to the lucky gainer--who chanced to be a native of Bouzy--of the great gold ingot lottery prize, value 16,000_l._, drawn in Paris some years ago. The Bouzy vineyards occupy a series of gentle inclines, and have the advantage of a full southern aspect. The soil, which is of the customary calcareous formation, has a marked ruddy tinge, indicative of the presence of iron, to which the wine is in some degree indebted for its distinguishing characteristics--its delicacy, spirituousness, and pleasant bouquet. Vintagers were passing slowly in between the vines, and carts laden with grapes came rolling over the dusty roads. The mountain which rises behind the vineyards is scored up its sides and fringed with foliage at its summit, and a small stone bridge crosses the deep ravine formed by the swift-descending winter torrents. [Illustration: THE VENDANGEOIR OF M. WERLÉ AT BOUZY.] The principal vineyard proprietors at Bouzy, which ranks, of course, as a _premier cru_, are M. Werlé, M. Irroy, and Messrs. Moët & Chandon, the first and last of whom have capacious vendangeoirs here, M. Irroy's pressing-house being in the neighbouring village of Ambonnay. M. Werlé possesses at Bouzy from forty to fifty acres of the finest vines, forming a considerable proportion of the entire vineyard area. At the Clicquot-Werlé vendangeoir, containing as many as eight presses, about 1000 pièces of wine are made annually. At the time of our visit, grapes gathered that morning were in course of delivery, the big basketfuls being measured off in caques--wooden receptacles holding two-and-twenty gallons--while the florid-faced foreman ticked them off with a piece of chalk on the head of an adjacent cask. As soon as the contents of some half-hundred or so of these baskets had been emptied on to the floor of the press, the grapes undetached from their stalks were smoothed compactly down, and a moderate pressure was applied to them by turning a huge wheel, which caused the screw of the press to act--a gradual squeeze rather than a powerful one, and given all at once, coaxing out, it was said, the finer qualities of the fruit. The operation was repeated as many as six times; the yield from the three first pressures being reserved for conversion into Champagne, while the result of the fourth squeeze would be applied to replenishing the loss, averaging 7-1/2 per cent, sustained by the must during fermentation. Whatever comes from the fifth pressure is sold to make an inferior Champagne. The grapes are subsequently well raked about, and then subjected to a couple of final squeezes, known as the _rébêche_, and yielding a sort of _piquette_, given to the workmen employed at the pressoir to drink. The small quantity of still red Bouzy wine made by M. Werlé at the same vendangeoir only claims to be regarded as a wine of especial mark in good years. The grapes, before being placed beneath the press, are allowed to remain in a vat for as many as eight days. The must undergoes a long fermentation, and after being drawn off into casks is left undisturbed for a couple of years. In bottle--where, by the way, it invariably deposits a sediment, which is indeed the case with all the wines of the Champagne, still or sparkling--it will outlive, we were told, any Burgundy. Still red Bouzy has a marked and agreeable bouquet and a most delicate flavour, is deliciously smooth to the palate, and to all appearances is as light as a wine of Bordeaux, while in reality it is quite as strong as Burgundy, to the finer crus of which it bears a slight resemblance. It was, we learnt, very susceptible to travelling, a mere journey to Paris being, it was said, sufficient to sicken it, and impart such a shock to its delicate constitution that it was unlikely to recover from it. To attain perfection, this wine, which is what the French term a _vin vif_, penetrating into the remotest corners of the organ of taste, requires to be kept a couple of years in wood and half a dozen or more years in bottle. [Illustration: THE AMBONNAY VINEYARDS.] From Bouzy it was only a short distance along the base of the vine-slopes to Ambonnay, where there are merely two or three hundred acres of vines, and where we found the vintage almost over. The village is girt with fir-trees, and surrounded with rising ground fringed either with solid belts or slender strips of foliage. An occasional windmill cuts against the horizon, which is bounded here and there by scattered trees. Inquiring for the largest vine-proprietor, we were directed to an open porte-cochère, and on entering the large court encountered half a dozen labouring men engaged in various farming occupations. Addressing one whom we took to be the foreman, he referred us to a wiry little old man, in shirt-sleeves and sabots, absorbed in the refreshing pursuit of turning over a big heap of rich manure with a fork. He proved to be M. Oury, the owner of we forget how many acres of vines, and a remarkably intelligent peasant, considering what dunderheads the French peasants as a rule are, who had raised himself to the position of a large vine-proprietor. Doffing his sabots and donning a clean blouse, he conducted us into his little salon, a freshly-painted apartment about eight feet square, of which the huge fireplace occupied fully one-third, and submitted patiently to our catechising. At Ambonnay, as at Bouzy, they had that year, M. Oury said, only half an average crop; the caque of grapes had, moreover, sold for exactly the same price at both places, and the wine had realised about 800 francs the pièce. Each hectare (2-1/2 acres) of vines had yielded 45 caques of grapes, weighing some 2-3/4 tons, which produced 6-1/2 pièces, equal to 286 gallons of wine, or at the rate of 110 gallons per acre. Here the grapes were pressed four times, the yield from the second pressure being used principally to make good the loss which the first sustained during its fermentation. As the squeezes given were powerful ones, all the best qualities of the grapes were by this time extracted, and the yield from the third and fourth pressures would not command more than eighty francs the pièce. The vintagers who came from a distance received either a franc and a half per day and their food, consisting of three meals, or two francs and a half without food, the children being paid thirty sous. M. Oury further informed us that every year vineyards came into the market, and found ready purchasers at from fifteen to twenty thousand francs the hectare, equal to an average price of 300_l._ the acre, which, although Ambonnay is classed merely as a second cru, has since risen in particular instances to upwards of 600_l._ per acre. Owing to the properties being divided into such infinitesimal portions, they were not always bought up by the large Champagne houses, who objected to be embarrassed with the cultivation of such tiny plots, preferring rather to buy the produce from their owners. There are other vineyards of lesser note in the neighbourhood of Reims producing very fair wines, which enter more or less into the composition of Champagne, and almost all of which can boast of a pedigree extending back at least to the Middle Ages. Noticeable among these are Ville-Dommange and Sacy, south-west of Reims. At Sacy the Abbey of St. Remi had a vineyard in 1218; and in the return of church property made in 1384, the doyen of the Cathedral is credited with 'rentes de vin' and about six _jours_ of vineland here, the Convent of Clermares at Reims owning a piece of 'vigne gonesse.' North-west of the city the best-known vineyards are those of Hermonville--mentioned likewise at the beginning of the thirteenth century, and in the return which we have just quoted--and St. Thierry, where the Black Prince took up his quarters during the siege of Reims, and where Gerard de la Roche wrought such havoc amongst the vines in the twelfth century, to the great indignation of their monkish owners. The still red wine of St. Thierry, which recalls the growths of the Médoc by its tannin, and those of the Côte d'Or by its vinosity, is to-day almost a thing of the past, it being found here, as elsewhere, more profitable to press the grapes for sparkling in preference to still wine. [Illustration: LABOURERS AT WORK IN THE EARLY SPRING IN M. ERNEST IRROY'S BOUZY VINEYARDS.] III. /The Vines of the Champagne and the System of Cultivation./ A combination of circumstances essential to the production of good Champagne--Varieties of vines cultivated in the Champagne vineyards--Different classes of vine-proprietors--Cost of cultivation--The soil of the vineyards--Period and system of planting the vines--The operation of 'provenage'--The 'taille' or pruning, the 'bêchage' or digging--Fixing the vine-stakes--Great cost of the latter--Manuring and shortening back the vines--The summer hoeing around the plants--Removal of the stakes after the vintage--Precautions adopted against spring frosts--The Guyot system of roofing the vines with matting--Forms a shelter from rain, hail, and frost, and aids the ripening of the grapes--Various pests that prey upon the Champagne vines--Destruction caused by the Eumolpe, the Chabot, the Bêche, the Cochylus, and the Pyrale--Attempts made to check the ravages of the latter with the electric light. [Illustration: CARRYING MANURE TO THE VINEYARDS.] Good Champagne does not rain down from the clouds, or gush out from the rocks, but is the result of incessant labour, patient skill, minute precaution, and careful observation. In the first place, the soil imparts to the natural wine a special quality which it has been found impossible to imitate in any other quarter of the globe. To the wine of Ay it lends a flavour of peaches, and to that of Avenay the savour of strawberries; the vintage of Hautvillers, though somewhat fallen from its former high estate, is yet marked by an unmistakably nutty taste; while that of Pierry smacks of the locally-abounding flint, the well-known _pierre à fusil_ flavour. So, on the principle that a little leaven leavens the whole lump, the produce of grapes grown in the more favoured vineyards is added in definite proportions, in order to secure certain special characteristics, as well as to maintain a fixed standard of excellence. While it is admitted that climate is not without its influence in imparting a delicate sweetness and aroma, combined with finesse and lightness, to the wine, some authorities maintain that to the careful selection of the vines best suited to the soil and temperature of the district the excellence of genuine Champagne is mainly to be ascribed. Four descriptions of vines are chiefly cultivated in the Champagne, three of them yielding black grapes, and all belonging to the pineau variety, from which the grand Burgundy wines are produced, and so styled from the clusters taking the conical form of the pine. The first is the franc pineau, the plant doré of Ay, with its closely-jointed shoots and small leaves, producing squat bunches of small round grapes, with thickish skins of a bluish-black tint, and sweet and refined in flavour. The next is the plant vert doré, with its leaves of vivid green, more robust and more productive than the former, but yielding a less generous wine, and the berries of which, growing in compact pyramidal bunches, are dark and oval, very thin-skinned, and remarkably sweet and juicy. The third variety, extensively planted in the vineyards of Verzy and Verzenay, is the plant gris, or burot, as it is styled in the Côte d'Or, a somewhat delicate vine, whose fruit has a brownish tinge, and yields a light and perfumed wine. The remaining species is a white grape known as the épinette, a variety of the pineau blanc, and supposed by some to be identical with the chardonnet of Burgundy, which yields the famous wine of Montrachet. It is met with all along the Côte d'Avize, notably at Cramant, the delicate and elegant wine of which ranks immediately after that of Ay and Verzenay. The épinette is a prolific bearer, and its round transparent golden berries, which hang in somewhat straggling clusters amongst its dark-green leaves, are both juicy and sweet. It ripens, however, much later than either of the black varieties. [Illustration: TYPES OF THE CHAMPAGNE VINES IN BEARING.] There are several other species of vines cultivated in the Champagne vineyards, notably the common meunier, or miller, prevalent in the valley of Epernay, which bears black grapes, and takes its name from the young leaves appearing to have been sprinkled with flour. This variety being more hardy than the franc pineau is replacing the latter on the lower parts of the slopes, which are the most exposed to frosts--a regrettable circumstance, as it impairs the quality of the wine. There are also the black and white gouais; the meslier, a prolific white variety yielding a wine of fair quality; the black and white gamais, the leading grape in the Mâconnais, and chiefly found in some of the Vertus vineyards; together with the tourlon, the marmot, the cohéras, the plant doux, and half a score of others. The land in the Champagne, as in other parts of France, is minutely subdivided, and it has been estimated that the 40,000 acres of vines are divided amongst no less than 16,000 proprietors. A few of the principal Champagne firms are large owners of vineyards; and as the value of the soil has more than quadrupled within the last thirty years, even the smallest peasant proprietors have cause for congratulation.[407] These latter cultivate their vineyards themselves; while the larger landowners employ labourers, termed _forains_ when coming from a distance and working by the week for their lodging, food, and from 20 to 30 francs wages, or _tâcherons_ when paid by the job. The last-mentioned class usually contract to cultivate and dress an arpent of vines, exclusive of the vintage, at from 8_l._ to 12_l._ per annum. In the Champagne the old rule holds good--poor soil, rich product, grand wine in moderate quantity. The soil of the vineyards is chalk, with a mixture of silica and light clay, combined with a varying proportion of oxide of iron. Many of the best have a substratum of stones and sand, and a thin superstratum of vegetable earth. The ruddier the soil, and consequently the more impregnated with ferruginous earth, the better suited it is found to the cultivation of black grapes; whilst the gray or yellowish soils, such as abound in the Côte d'Avize, are preferable for the white varieties. [Illustration: MANURING THE NEWLY-PLANTED YOUNG VINES.] The vines are almost invariably planted on rising ground, the lower slopes, which seldom escape the spring frosts, producing the best wines. The vines are placed very close together, there often being as many as six within a square yard, and the result is that they reciprocally impoverish each other. Planting takes place between November and April, the vine-growers of the River being usually in advance of those of the Mountain in this operation. Plants two or three years old and raised in nurseries are usually made use of. These are placed either in holes or trenches. The roots have a little earth sprinkled over them, to which a liberal supply of manure or compost is added, and the holes having been filled up and trodden, the vines are pruned down to a couple of buds above the ground. [Illustration: VINE PREPARED FOR 'PROVINAGE.'] In the course of two or three years they are ready for the operation of 'provinage,' or layering, a method of multiplication universally practised in the Champagne. This consists in burying in a trench, from six to eight inches deep dug on one side of the plant, two or more of the principal shoots, left when the vine was pruned for this especial purpose. The whole of the two-years'-old wood is thus buried, and the ends of the shoots of one-year-old, which are left above ground, are cut down to the second bud. The shoots thus laid underground are dressed with a light manure, and in course of time take root and form new vines, which bear during their second year. This operation is performed simultaneously with the 'bêchage' in the early spring, and is annually repeated until the vine is five years old, the plants thus being in a state of continual progression; a system which accounts for the juvenescent aspect of the Champagne vineyards, where none of the wood of the vines showing above ground is more than three years old. [Illustration: PLAN OF 'PROVINAGE À L'ÉCART' IN A NEWLY-PLANTED VINEYARD.] The two principal plans adopted in provining are styled the 'écart' and the 'avance.' In the first, which is usually followed in newly-planted vineyards, the two shoots are carried forward to the right and left--so as to form the two base points of an equilateral triangle, of which the point of departure is the summit--and are maintained in this position by the aid of wooden or iron pegs. In the 'provinage à l'avance' both shoots are carried forward in the same direction, and sometimes a variation embodying the two systems is employed. [Illustration: PROVINAGE À L'ÉCART.] [Illustration: PROVINAGE À L'AVANCE.] When the vine has attained its fifth year it is allowed to rest for a couple of years, and then the provining is resumed, the shoots being dispersed in any direction throughout the vineyard, so as to fill up vacancies. The plants remain in this condition henceforward, merely requiring to be renewed from time to time by judicious provining. For instance, it is sometimes found necessary to bend one of the shoots round into a circle, so that its end may issue from the ground at the point occupied by the parent stock. The system of provinage is sometimes carried to excess in the Champagne, with a view of increasing the yield of wine, which suffers, however, in quality. The network of roots, too, renders the various operations of cultivation difficult and dangerous, as they are liable to be injured by the short-handled hoe in universal use among the Champenois vine-dressers. [Illustration: TRIPLE 'PROVINAGE' TO REPLACE THE PARENT STOCK.] Viticulturists inclined to make experiments have tried the system of arranging the vines in transverse and longitudinal lines, quincunxes, &c., or have replaced their vine-stakes with iron wires supported by wooden pickets. Some of these experiments have proved successful, although none of them are as yet in general use. [Illustration: VINE DRESSER'S HOE.] [Illustration: VINE PRIOR TO THE FEBRUARY PRUNING, SHOWING THE EXTENT OF ROOT.] The first operation of importance carried out during the year in the vineyards is the 'taille,' or pruning, which takes place in February, and consists in cutting away the superfluous shoots, simply leaving one--or, if it is intended to multiply by provinage, two--on each stock. This is followed about March or April by the 'bêchage,' or 'hoyerie'--that is, the digging round the roots of the vine--with which is combined the provinage. A trench being opened, as already noted, and the vine laid bare to the roots, it is bent down so that, on filling up the trench with earth and manure, the stock is entirely covered and only the new wood appears above ground. This new wood is then shortened back, and the stakes intended for the support of the vines are fixed in the ground. These stakes are set up in the spring of the year by men or women, the former of whom force them into the ground by pressing against them with their chest, which is protected with a shield of wood. The women use a mallet, or have recourse to a special appliance, in working which the foot plays the principal part. The latter method is the least fatiguing, and in some localities is practised by the men. An expert labourer will set up as many as 5000 stakes in the course of the day. When of oak these stakes cost sixty francs the thousand; and as the close system of plantation followed in the Champagne renders the employment of no less than 24,000 stakes necessary on every acre of land, the cost per acre of propping up the vines amounts to upwards of 57_l._, or more than treble what it is in the Médoc and quadruple what it is in Burgundy. The stakes last only some fifteen years, and their renewal forms a serious item in the vine-grower's budget. [Illustration: VINES IN FEBRUARY AFTER THE 'TAILLE.'] [Illustration: THE 'BÊCHAGE' OF THE VINES.] [Illustration: PUTTING STAKES TO THE VINES IN THE SPRING.] [Illustration: APPARATUS FOR FIXING VINE-STAKES.] [Illustration: UNSTACKING THE VINE-STAKES.] [Illustration: NEWLY-STAKED VINES AFTER THE 'BÊCHAGE.'] [Illustration: VINES IN AUTUMN AFTER THE VINTAGE.] In May or June, after the vines have been hoed around their roots, they are secured to the stakes, and their tops are broken off at a shoot to prevent them from growing above the regulation height, which is ordinarily from 30 to 33 inches. They are liberally manured with a kind of compost formed of the loose friable soil termed 'cendre'--dug out from the sides of the hills, and of supposed volcanic origin--mixed with animal and vegetable refuse. The vines are shortened back while in flower, and in the course of the summer the ground is hoed a second and a third time, the object being, first, to destroy the superficial roots of the vines and force the plants to live solely on their deep roots; and secondly, to remove all pernicious weeds from round about them. After the third hoeing, which takes place in the middle of August, the vines are left to themselves until the period of the vintage, excepting that some growers remove a portion of the leaves in order that the grapes may receive the full benefit of the sun, and raise up those bunches that rest upon the ground. The vintage over, the stakes supporting the vines are pulled up later in the autumn and stacked in compact masses, styled 'moyères,' with their ends out of the ground, or else 'en chevalet,' the vine, which is left curled up in a heap, remaining undisturbed until the winter, when the earth around it is loosened. In the month of February following the vine is pruned and subsequently sunk into the earth, as already described, so as to leave only the new wood above ground. Owing to the vines being planted so closely together they naturally starve one another, and numbers of them perish. Whenever this is the case, or the stems chance to get broken during the vintage, their places are filled up by provining. [Illustration: STACKING STAKES 'EN CHEVALET.'] [Illustration: STACKING STAKES IN A 'MOYÈRE.'] The vignerons of the Champagne regard the numerous stakes which support the vines as affording some protection against the white frosts of the spring. To guard against the dreaded effects of these frosts, which invariably occur between early dawn and sunrise, and the loss arising from which is estimated to amount annually to 25 per cent, some of the cultivators place heaps of hay, fagots, dead leaves, &c., about twenty yards apart, taking care to keep them moderately damp. When a frost is feared the heaps on the side of a vineyard whence the wind blows are set light to, whereupon the dense smoke which rises spreads horizontally over the vines, producing the same result as an actual cloud, intercepting the rays of the sun, warming the atmosphere, and converting the frost into dew. Among other methods adopted to shield the vines from frosts is the joining of branches of broom together in the form of a fan, and afterwards fastening them to the end of a pole, which is placed obliquely in the ground, so that the fan may incline over the vine and protect it from the sun's rays. A single labourer can plant, it is said, as many as eight thousand of these fans in the ground during a long day. [Illustration: UNROLLING MATTING FOR ROOFING THE VINES WITH.] Dr. Guyot's system of roofing the vines with straw matting, to protect them alike against frosts and hailstorms, is very generally followed in low situations in the Champagne, the value of the wine admitting of so considerable an expense being incurred. This matting, which is made about a foot and a half in width, and in rolls of great length, is fastened either with twine or wire to the vine-stakes; and it is estimated that half a dozen men can fix nearly 11,000 yards of it, or sufficient to roof over 2-1/2 acres of vines, during an ordinary day. To carry out the system properly, a double row of tall and short stakes connected with iron wires has to be provided. The matting can then be used as a shelter to the young vines in spring, as a south wall to aid the ripening of the grapes in summer, and as a protection against rain and autumn frosts. [Illustration: MATTING ARRANGED TO AID THE RIPENING OF THE GRAPES.] [Illustration: MATTING ARRANGED TO PROTECT THE VINES AGAINST AUTUMN FROSTS.] Owing to the system of cultivation by rejuvenescence, and the constant replenishing of the soil by well-compounded manures, the Champenois wine-growers entertain great hopes that their vineyards will escape the ravages of the phylloxera vastatrix. They certainly deserve such an immunity, for, according to Dr. Plonquet of Ay, they are already the prey of no less than fifteen varieties of insects, which feed upon the leaves, stalks, roots, or fruit of the vines. One of the most destructive of these is the eumolpe, gribouri, or écrivain as it is popularly styled, from the traces it leaves upon the vine-leaves bearing some resemblance to lines of writing. It is a species of beetle, the larvæ of which pass the winter amongst the roots of the vine, and in the spring attack the young leaves and buds, their ravages often proving fatal to the plant. Then there is the chabot, which has caused great destruction at Verzy and Verzenay; the attelabe, cunche, or bêche, which rolls up the leaves of the vine like cigars, and seems to be identical with the hurebet or urbec of the Middle Ages; and the cochylis, teigne, or vintage-worm, which develops into a white-and-black butterfly, producing in the course of the year two generations of larvæ, having the form of small red caterpillars, one of which attacks the blossoms of the vine, while the second pierces and destroys the grapes themselves. The list of foes further comprises the altise, a kind of beetle allied to the gribouri; the liset or coupe-bourgeon, a tiny worm assailing the first sprouting shoots; and the hanneton or cockchafer. [Illustration: MATTING ARRANGED TO KEEP OFF RAIN OR HAIL.] [Illustration: THE PYRALE.] The greatest havoc, however, appears to be wrought by the pyrale, a species of caterpillar, which feeds on the young leaves, flowers, and shoots until the vine is left completely bare. The larva of this insect, after passing the winter either in the crevices of the stakes or in the cracks in the bark of the vine, emerges in the spring, devours leaves, buds, and shoots indifferently, and eventually becomes transformed into a small yellow-and-brown butterfly, which deposits its eggs amongst the bunches of grapes in July. Between 1850 and 1860 the vineyards of Ay were devastated by the pyrale, which, like the locusts of Scripture, spared no green thing; and all the efforts made to rid them of this scourge proved ineffectual until the wet and cold weather of 1860 put a stop to the insect's ravages.[408] More recently it was discovered that its attacks could be checked by sulphurous acid, or by scalding the stakes and the vine-stocks with boiling water during the winter. Nevertheless, it appeared impossible to check its destructiveness at Ay, where it made its reappearance in 1879, and caused an immense amount of damage. On this occasion an ingenious gentleman, M. Testulat Gaspar, was seized with the idea of combating the pyrale by means of the electric light. His theory was, that on a powerful light being exhibited in a central position at midnight amongst the vineyards, with a number of tin reflectors distributed in every direction around, the butterflies, roused from slumber, would wing their way in myriads towards the latter, when their flight could be arrested by sheets of muslin stretched between poles, smeared with honey and baited with a dash of Champagne liqueur. The theory was put to the test in August 1879, amongst the vineyards between Dizy and Ay, where the pyrale was committing the greatest ravages. The light was turned on, and the butterflies rose 'in millions;' but they failed to flock to the reflectors, and the honey-smeared muslin proved quite useless to secure the few which came in contact with it. [Illustration: A VINTAGE SCENE IN THE CHAMPAGNE.] IV. /The Vintage in the Champagne./ Period of the Champagne vintage--Vintagers summoned by beat of drum--Early morning the best time for plucking the grapes--Excitement in the neighbouring villages at vintage-time--Vintagers at work--Mules employed to convey the gathered grapes down the steeper slopes--The fruit carefully examined before being taken to the wine-press--Arrival of the grapes at the vendangeoir--They are subjected to three squeezes, and then to the 'rébêche'--The must is pumped into casks and left to ferment--Only a few of the vine-proprietors in the Champagne press their own grapes--The prices the grapes command--Air of jollity throughout the district during the vintage--Every one is interested in it, and profits by it--Vintagers' fête on St. Vincent's-day--Endless philandering between the sturdy sons of toil and the sunburnt daughters of labour. [Illustration: WINE-PRESS IN THE CHAMPAGNE.] When the weather has been exceedingly propitious, the vintage in the Champagne commences as early as the third week in September, and in good average years the pickers set to work during the first week of October. If, however, the summer has been an indifferent one, and only an inferior vintage is looked forward to, it is scarcely before the latter half of October that the gathering of the grapes is proceeded with. There is no vintage-ban in the Champagne, as in Burgundy and other parts of France; but, as a rule, the growers of Ay and of the neighbouring slopes commence operations a week or more earlier than those of the Mountain of Reims, whilst around Cramant and Avize, the white-grape region, the vintagers usually set to work when in the other districts they have nearly finished. [Illustration: THE CHAMPAGNE VINTAGE IN THE NEIGHBOURHOOD OF EPERNAY.] The pleasantest season of the year to visit the Champagne is certainly during the vintage. When this is about to commence, the vintagers--some of whom come from Sainte Menehould, forty miles distant, while others hail from as far as Lorraine--are summoned at daybreak by beat of drum in the market-places of the villages adjacent to the vineyards, and then and there a price is made for the day's labour. This, as we have already explained, is generally either a franc and a half, with food consisting of three meals, or two francs and a half, rising on exceptional occasions to three francs, without food, children being paid a franc and a half. The rate of wage satisfactorily arranged, the gangs start off to the vineyards, headed by their overseers. The picking ordinarily commences with daylight, and the vintagers assert that the grapes gathered at sunrise always produce the lightest and most limpid wine. Moreover by plucking the grapes when the early morning sun is upon them, they are believed to yield a fourth more juice. Later on in the day, too, spite of all precautions, it is impossible to prevent some of the detached grapes from partially fermenting, which frequently suffices to give a slight excess of colour to the must, a thing especially to be avoided in a high-class Champagne. When the grapes have to be transported in open baskets for some distance to the press-house, jolting along the road either in carts or on the backs of mules, and exposed to the torrid rays of a bright autumnal sun, the juice expressed from the fruit, however dexterously the latter may be squeezed in the press, is occasionally of a positive purple tinge, and consequently useless for conversion into Champagne. [Illustration] At vintage-time everywhere is bustle and excitement; every one is big with the business in hand. In these ordinarily quiet little villages nestling amidst vine clad hollows, or perched half-way up a slope tinted from base to summit with richly-variegated hues, there is a perpetual pattering of sabots and a rattling and bumping of wheels over the roughly-paved streets. The majority of the inhabitants are afoot: the feeble feminine half, baskets on arm, thread their way with the juveniles through the rows of vines planted half-way up the mountain, and all aglow with their autumnal glories of green and purple, crimson and yellow; while the sturdy masculine portion are mostly passing to and fro between the press-houses and the wine-shops. Carts piled up with baskets, or crowded with peasants from a distance on their way to the vineyards, jostle the low railway-trucks laden with brand-new casks, and the somewhat rickety cabriolets of the agents of the big Champagne houses, who are reduced to clinch their final bargain for a hundred or more pièces of the peerless wine of Ay or Bouzy, Verzy or Verzenay, beside the reeking wine-press. Dotting the steep slopes like a swarm of huge ants are a crowd of men, women, and children, the men, in blue blouses or stripped to their shirt-sleeves, being for the most part engaged in carrying the baskets to and fro and loading the carts; whilst the women, in closely-fitting neat white caps, or wearing old-fashioned unbleached straw-bonnets of the contemned coalscuttle type, resembling the 'sun-bonnet' of the Midland counties, together with the children, are intent on stripping the vines of their luscious-looking fruit. They detach the grapes with scissors or hooked knives, technically termed 'serpettes,' and in some vineyards proceed to remove all damaged, decayed, or unripe fruit from the bunches before placing them in the baskets which they carry on their arms, and the contents of which they empty from time to time into a larger basket resembling an ass's pannier in shape, numbers of these being dispersed about the vineyard for the purpose, and invariably in the shade. When filled the baskets are carried by a couple of men to the roadside, along which dwarf stones carved with initials, and indicating the boundaries of the respective properties, are encountered every eight or ten yards, into such narrow strips are the vineyards divided. Large carts with railed open sides are continually passing backwards and forwards to pick these baskets up; and when one has secured its load it is driven slowly to the neighbouring pressoir, so that the grapes may not be in the least degree shaken, such is the care observed throughout every stage of the process of Champagne manufacture. When the vineyard slopes are very steep--as, for instance, at Mareuil--and the paths do not admit of the approach of carts, mules, equipped with panniers and duly muzzled, are employed to convey the gathered fruit to the press-house. [Illustration] [Illustration] In many vineyards the grapes are inspected in bulk instead of in detail before being sent to the wine-press. The hand-baskets, when filled, are brought to a particular spot, where their contents are minutely examined by some half-dozen men and women, who pluck off the bruised, rotten, and unripe berries, and fling them aside into a separate basket. In other vineyards we came upon parties of girls, congregated round a wicker sieve perched on the top of a large tub by the roadside, engaged in sorting the grapes, pruning away the diseased stalks, and picking off all the doubtful berries. The latter were let fall through the interstices of the sieve, while the sound fruit was deposited in large baskets standing beside the sorters, and which, as soon as they were filled, were conveyed to the pressoir. When the proprietor is of an economic turn he usually has the refuse grapes pressed for wine for home consumption. Spite of the minute examination to which the grapes are subjected, a sharp eye will frequently discover in the heart of what looks like a regular and well-grown bunch a grape that is absolutely rotten, and capable of infecting its companions when the whole are heaped up together in the wine-press. [Illustration: ARRIVAL OF THE GRAPES AT THE PRESS-HOUSE.] [Illustration: THE VINTAGE IN THE CHAMPAGNE: A WINE-PRESS AT WORK.] Carts laden with grapes are continually arriving at the pressoirs, discharging their loads and driving off for fresh ones. The piled-up baskets, marked with the names of the vineyard-owners whose grapes they contain, are temporarily stored under a shed in a cool place, and are brought into the pressoir from time to time as required. In the district of the River the grapes are weighed, while in that of the Mountain they are measured, before being emptied on to the floor of the press. In some places the latter is of the old-fashioned type, resembling the ordinary cider-press; but usually powerful presses of modern invention, worked by a large fly-wheel requiring four sturdy men to turn it, are employed. The grapes are spread over the floor of the press in a compact mass, and in some rare cases are lightly trodden by a couple of men with their naked feet before being subjected to mechanical pressure, which is again and again repeated, only the first squeeze giving a high-class wine, and the second and third a relatively inferior one. After three pressures the grapes are usually worked about with peels, and subjected to a final squeeze known as the 'rébêche,' which produces a sort of _piquette_, given to the workmen to drink, but in many instances forming the habitual, and indeed only, beverage of the economically-inclined peasant proprietor. The must filters through a wicker basket into the reservoir beneath, whence, after remaining a certain time to allow of its ridding itself of the grosser lees, it is pumped through a gutta-percha tube into the casks. The wooden stoppers of the bungholes, instead of being fixed tightly in the apertures, are simply laid over them, and after the lapse of ten or twelve days fermentation usually commences, and during its progress the must, which is originally of a pale-pink tint, fades to a light-straw colour. The wine usually remains undisturbed until Christmas, when it is drawn off into fresh casks and delivered to the purchaser. One peculiarity of the Champagne district is that, contrary to the prevailing practice in the other wine-producing regions of France, where the owner of even a single acre of vines will crush his grapes himself, only a limited number of vine-proprietors press their own grapes. The large Champagne houses, possessing vineyards, always have their pressoirs in the neighbourhood, and other large vine-proprietors press the grapes they grow; but the multitude of small cultivators invariably sell the produce of their vineyards to one or other of the former at a certain rate, either by weight or else by caque, a measure estimated to hold sixty kilogrammes (equal to 132 lb. avoirdupois) of grapes. The price which the fruit fetches varies of course according to the quality of the vintage and the requirements of the manufacturers; but the average may be taken at about 80 centimes per kilogramme, equivalent to rather more than 3-1/2_d._ per lb.[409] [Illustration] If in the Champagne the picturesque rejoicings immortalised in the Italian vintage scenes of Léopold Robert are lacking, and if the grapes, instead of being trodden to the blithe accompaniment of flute and fiddle, as in some parts of France, are pressed in more quiet fashion, a pleasant air of jollity nevertheless pervades the district at the season of the vintage. Every one participates in the interest which this excites. It influences the takings of all the artificers and all the tradespeople, and brings grist to the mill of the baker and the bootmaker, as well as to the café and cabaret. The contending interests of capital and labour are, moreover, singularly satisfied, the vintagers being content at getting their two francs and a half a day, and the men at the pressoirs their three francs and their food; the vineyard proprietor reaping the return of the time, care, and money expended upon his patch of vines, and the Champagne manufacturer acquiring raw material on sufficiently satisfactory terms, the which, when duly guaranteed by his name and brand, will bring to him both fame and fortune. Should the vintage be a scanty one, the plethoric _commissionnaires-en-vins_ will wipe their perspiring foreheads with satisfaction when they have at last secured the full number of hogsheads they had been instructed to buy--at a high figure maybe; still this is no disadvantage to them, as their commission mounts up the higher. And even the thickest-skulled among the small vine-proprietors, who make all their calculations on their fingers, see at a glance that, although the crop may be no more than half an average one, they are gainers, thanks to the ill-disguised anxiety of the agents to secure all the wine they require, which has the effect of sending prices up to nearly double those of ordinary years, and this with only half the work in the vineyard and at the winepress to be done. [Illustration] The vintage in the Champagne comes to a close without any of those festivals which still linger in the department of the Gironde. On the 22d of January, the fête of St. Vincent, the patron saint of vine-growers, it is customary, however, for one of the proprietors in each village to pay for a mass and give a breakfast to his relatives and friends, at which he presents a bouquet to one of the guests, who, in his turn, is expected to pay for the mass and give the breakfast the year following. On the same day the proprietors entertain their workpeople, who, after having eaten and drunk their fill, wind up the day with song and dance, leading to no end of innocent philandering between the sturdy sons of toil and the sunburnt daughters of labour. On these occasions the famous vintage song is sometimes heard: 'Vendangeons et vive la France, Le monde un jour avec nous trinquera.' [Illustration] [Illustration: THE DISGORGING, LIQUEURING, CORKING, STRINGING, AND WIRING OF CHAMPAGNE.] V. /The Preparation of Champagne./ The treatment of Champagne after it comes from the wine-press--The racking and blending of the wine--The proportions of red and white vintages composing the 'cuvée'--Deficiency and excess of effervescence--Strength and form of Champagne bottles--The 'tirage' or bottling of the wine--The process of gas-making commences--Details of the origin and development of the effervescent properties of Champagne--The inevitable breakage of bottles which ensues--This remedied by transferring the wine to a lower temperature--The wine stacked in piles--Formation of sediment--Bottles placed 'sur pointe' and daily shaken to detach the deposit--Effect of this occupation on those incessantly engaged in it--The present system originated by a workman of Madame Clicquot's--'Claws' and 'masks'--Champagne cellars--Their construction and aspect--Raw recruits for the 'Regiment de Champagne'--Transforming the 'vin brut' into Champagne--Disgorging and liqueuring the wine--The composition of the liqueur--Variation in the quantity added to suit diverse national tastes--The corking, stringing, wiring, and amalgamating--The wine's agitated existence comes to an end--The bottles have their toilettes made--Champagne sets out on its beneficial pilgrimage round the world. [Illustration] The special characteristic of Champagne is that its manufacture only commences where that of other wines ordinarily ends. No one would recognise in the still brut fluid--which, after being duly racked and fined, has somewhat the taste and colour of an acrid Rhine wine, with a more or less pronounced bitter flavour--that exhilarating essence which is capable of raising the most depressed spirits, and imparting gaiety to the dismallest gatherings. Much as Champagne may stand indebted to Nature, soil, climate, and species of vine, the sparkling fluid has contracted a far greater debt towards man, to whose incessant labour, patient skill, and minute precautions it owes that combination of qualities which causes it to be so highly prized. In the preceding chapter we left the newly-expressed must flowing direct from the press into capacious reservoirs, whence it is drawn off into large vats, where it clears itself by depositing its mucous lees, usually within twenty-four hours. It is then transferred to new or perfectly clean casks, holding some forty gallons each, in which a sulphur match has been previously burnt. These casks are not filled quite up to the bunghole, which is generally covered with a vine-leaf kept in its place by a piece of tile. The bulk of the newly-made wine is left to repose at the vendangeoirs until the commencement of the following year; still, when the vintage is over, numbers of long narrow carts laden with casks of newly-expressed must may be seen rolling along the dusty highways, bound for those towns and villages in the department of the Marne where the manufacture of Champagne is carried on, and where the leading firms have their establishments. Chief amongst these is the cathedral city of Reims, after which comes the rising town of Epernay, stretching to the very verge of the river; then Ay, nestling between the vine-clad slopes and the Marne canal, with the neighbouring village of Mareuil; next Pierry; and finally Avize, in the centre of the white-grape district southwards of Epernay. Châlons, owing to its distance from the vineyards, does not usually draw its supply of wine until the new year. In the vast celliers of the manufacturers' establishments, where a temperature of about 60 to 70 degrees Fahrenheit usually prevails, the wine undergoes its first fermentation, entailing a loss of about 7-1/2 per cent, and lasting from a fortnight to a month, according as to whether the wine be _mou_--that is, rich in sugar--or the reverse. In the former case fermentation naturally lasts much longer than when the wine is _vert_ or green. This active fermentation is converted into latent fermentation by transferring the wine to a cooler cellar, as it is essential it should retain a certain proportion of its natural saccharine to insure its future effervescence. The casks have previously been completely filled, and their bungholes tightly stopped, a necessary precaution to guard the wine from absorbing oxygen, the effect of which would be to turn it yellow, and cause it to lose some of its lightness and perfume. After being racked and fined--an operation generally performed about the third week in December--the produce of the different vineyards is ready for mixing together in accordance with the traditional theories of the various manufacturers; and should the vintage have been an indifferent one, a certain proportion of old reserved wine of a good year enters into the blend. The mixing is usually effected in gigantic vats holding at times as many as 12,000 gallons each, and having fan-shaped appliances inside, which, on being worked by handles, insure a complete amalgamation of the wine. This process of marrying wine on a gigantic scale is technically known as making the _cuvée_. Usually four-fifths of wine obtained from black grapes, and now of a pale-pink hue, are tempered by one-fifth of the juice of white ones. It is necessary that the first should comprise a more or less powerful dash of the finer growths both of the Mountain of Reims and of the River; while, as regards the latter, one or other of the delicate vintages of the Côte d'Avize is essential to the perfect _cuvée_. The aim is to combine and develop the special qualities of the respective crus, body and vinosity being secured by the red vintages of Bouzy and Verzenay, softness and roundness by those of Ay and Dizy, and lightness, delicacy, and effervescence by the white growths of Avize and Cramant. The proportions are never absolute, but vary according to the manufacturer's style of wine and the taste of the countries which form his principal markets. In the opinion of some clever amalgamators, a blend comprising one-third of the vintages of Sillery, Verzenay, and Bouzy, one-third of those of Mareuil, Ay, and Dizy, and the remaining third composed of the produce of Pierry, Cramant, and Avize, constitutes the wine of Champagne _par excellence_. Others not less expert declare that a simple mixture of the Ay, Pierry, and Cramant vintages furnishes a perfect wine. As when this blending takes place the wine is only imperfectly fermented and exceedingly crude, the reader may imagine the delicacy and discrimination of palate requisite to judge of the flavour, finesse, and bouquet which the _cuvée_ is likely eventually to develop. These, however, are not the only matters to be considered. There is, above everything, the effervescence, which depends upon the quantity of carbonic acid gas the wine already contains, and the further quantity it is likely to develop, which depends upon the amount of its natural saccharine. After the bottling, if the gas be present in excess, there will be a shattering of bottles and a flooding of cellars; while, on the other hand, if there be a paucity, the corks will refuse to pop, and the wine to sparkle aright in the glass. The amount of saccharine in the _cuvée_ has therefore to be accurately ascertained by means of a glucometer; and should it fail to reach the required standard, as is the case at times when the season has been wet and cold and the vintage a poor one, the deficiency is made up by the addition of the purest sugar-candy. If, on the other hand, there be an excess of saccharine, the only thing to be done is to defer the final blending and bottling of the wine until the superfluous saccharine matter has been absorbed by fermentation in the cask. [Illustration] The _cuvée_ completed, the blended wine, which in its present condition gives to the uninitiated palate no promise of the exquisite delicacy and aroma it is destined to develop, is drawn off again into casks for further treatment. This comprises fining with some gelatinous substance, usually isinglass, made into a jelly and strained through a 'tammy;' while, as a precaution against ropiness and other maladies, liquid tannin, derived from nut-galls, catechu, or grape husks and pips, is at the same time frequently added to supply the place of the natural tannin, which has departed from the wine with its reddish hue at the epoch of its first fermentation. If at the expiration of a month the wine has not become perfectly clear and limpid, it is racked off the lees, and the operation of fining is repeated. [Illustration] The operation of bottling the wine next ensues, when the scriptural advice not to put new wine into old bottles is rigorously followed. For the tremendous pressure of the gas engendered during the subsequent fermentation of the wine is such that the bottle becomes weakened, and can never be safely trusted again.[410] It is because of this pressure that the Champagne bottle is one of the strongest made, as indicated by its weight, which is almost a couple of pounds. To insure this unusual strength, it is necessary that the sides should be of equal thickness and the bottom of a uniform solidity throughout, in order that no particular expansion may ensue from sudden changes of temperature. The neck must, moreover, be perfectly round and widen gradually towards the shoulder. In addition--and this is of the utmost consequence--the inside ought to be perfectly smooth, as a rough interior causes the gas to make efforts to escape, and thus renders an explosion imminent. The composition of the glass, too, is not without its importance, as on one occasion a manufactory established for the production of glass by a new process turned out Champagne bottles charged with alkaline sulphurets, and the consequence was that an entire _cuvée_ was ruined by their use, through the reciprocal action of the wine and these sulphurets. The acids of the former disengaged hydrosulphuric acid, and instead of Champagne the result was a new species of mineral water. Most of the bottles used for Champagne come from the factories of Loivre (which supplies the largest quantity), Folembray, Vauxrot, and Quiquengrogne, and they cost on the average from 28 to 33 francs the hundred.[411] They are generally tested by a practised hand, who, by knocking them sharply together, professes to be able to tell, from the sound that they give, the substance of the glass and its temper, though occasionally a special machine, subjecting them to hydraulic pressure, is had recourse to. [Illustration] The operation of washing, which takes place immediately preceding the bottling of the wine, is invariably performed by women, who at the larger establishments accomplish it with the aid of machines, provided at times with a revolving brush, although small glass beads are generally used by preference. Each bottle after being washed is minutely examined, to make certain of its perfect purity, and is then placed neck downwards in a tall basket to drain. [Illustration: MACHINE FOR FIXING THE AGRAFES.] With the different Champagne houses the mode of bottling the wine, which may take place any time between April and August, varies in some measure, still the _tirage_, as this operation is called, is ordinarily effected as follows: The wine, after a preliminary test as to its fitness for bottling, is emptied from the casks into vats or tuns of varying capacity in the _salle du tirage_. From these it flows through pipes into oblong reservoirs, each provided with a row of syphon-taps, on to which the bottles are slipped, and from which the wine ceases to flow directly the bottles become filled. Men or lads remove the full bottles, replacing them by empty ones, while other hands convey them to the corkers, whose guillotine machines are incessantly in motion. Speed in the process is of much importance, as during a single day the wine may undergo a notable change. From the corkers the bottles are passed on to the _agrafeurs_, who secure the corks by means of an iron clip termed an agrafe; and they are afterwards conveyed either to a spacious room above-ground known as a cellier or to a cool vault underground, according to the number of atmospheres which the wine may indicate. [Illustration] With reference to these atmospheres, it should be explained that air compressed to half its volume acquires twice its ordinary force, and to a quarter of its volume quadruple this force--hence the phrase of two, four, or more atmospheres. The exact degree of pressure is readily ascertained by means of a manometer, an instrument resembling a pressure-gauge, with a hollow screw at the base, which is driven through the cork of the bottle. A pressure of 5-3/4 atmospheres constitutes what is styled a 'grand mousseux,' and the wine exhibiting it may be safely conveyed to the coolest subterranean depths, for no doubt need be entertained as to its future effervescent properties. Should the pressure, however, scarcely exceed four atmospheres, it is advisable to keep the wine in a cellier above-ground, that it may more rapidly acquire the requisite sparkling qualities. If fewer than four atmospheres are indicated, it would be necessary to pour the wine back into the casks again, and add a certain amount of cane-sugar to it; but such an eventuality very rarely happens, thanks to the scientific formulas and apparatus, which enable the degree of pressure the wine will show to be determined beforehand to a nicety. Still mistakes are sometimes made, and there are instances where charcoal fires have had to be lighted in the cellars to encourage the latent effervescence to develop itself.[412] [Illustration: THE TIRAGE OR BOTTLING OF CHAMPAGNE.] The bottles are first placed in a horizontal position, the side to be kept uppermost being indicated by a daub of whitewash, and are stacked in rows of varying length and depth, one above the other, to about the height of a man, with narrow laths between them. Thus they will spend the summer, providing all goes well; but in about three weeks' time the process of gas-making inside the bottles is at its height, and a period of considerable anxiety to the Champagne manufacturer ensues, through his dread lest an undue number of them should burst from the expansion of the carbonic acid gas generated in the wine. The glucometer notwithstanding, it is impossible to check a certain amount of breakage, especially when a hot season has caused the grapes, and consequently the raw wine, to be sweeter than usual. Moreover, when once _casse_ or breakage sets in on a large scale, the temperature of the cellar is raised by the volume of carbonic acid gas let loose, which is not without its effect on the remaining bottles. Not only does the increased temperature unduly accelerate fermentation, but the mere shock of one bottle exploding often starts such of its neighbours as are predisposed that way, in addition to the direct havoc wrought by the heavier fragments of flying glass. The only remedy is the instant removal of the wine to a lower temperature whenever this is practicable. [Illustration] A manufacturer of the pre-scientific days of the last century relates how one year, when the wine was rich and strong, he only preserved 120 out of 6000 bottles; and it is not long since that 120,000 out of 200,000 were destroyed in the cellars of a well-known Champagne firm. M. Mauméné, moreover, relates that in 1850 he was called in to consult about the checking of a _casse_, which had already reached 96 per cent.[413] Over-knowing purchasers affect to select a wine which has exploded in the largest proportion in the cellars, as being well up to the mark as regards its effervescence, and are in the habit of making inquiries as to its performances in this direction. [Illustration] It is evident that, in spite of the teachings of science, the bursting of Champagne bottles has not yet been reduced to a minimum, for whereas in some cellars it averages 7 and 8 per cent, and rises to 15 when the pressure is unusually strong, in others it rarely exceeds 2-1/2 or 3. The period between May and September is that in which the greatest destruction takes place. In the month of October, the first and severest breakage being over, the newly-bottled wine is definitively stacked in the cellars in piles from two to half a dozen bottles deep, from six to seven feet high, and frequently a hundred feet or upwards in length. Usually the bottles remain in their horizontal position, in which they gradually develop two essential qualities, that of effervescing well and that of travelling satisfactorily, for about eighteen or twenty months, though some firms, who pride themselves upon shipping perfectly matured wines, leave them thus for double this space of time. During this period the temperature to which the wine is exposed is, as far as practicable, carefully regulated; for the risk of breakage, though greatly diminished, is never entirely at an end. [Illustration] [Illustration] By this time the fermentation is over; but in the interval, commencing from a few days after the bottling of the wine, a loose dark-brown sediment has been forming, which has now settled on the lower side of the bottle, and to get rid of which is a delicate and tedious task. As the time approaches for preparing the wine for shipment, the bottles are placed _sur pointe_, as it is termed--that is to say, slantingly in racks with their necks downwards, the inclination being increased from time to time to one more abrupt.[414] The object of this change in their position is to cause the sediment to leave the side of the bottle where it has gathered. Afterwards it becomes necessary to twist and turn it and coagulate it, as it were, until it forms a kind of muddy ball, and eventually to get it well down into the neck of the bottle, so that it may be finally expelled with a bang when the temporary cork is removed and the proper one adjusted. To accomplish this the bottles are sharply turned in one direction every day for at least a month or six weeks, the time being indefinitely extended until the sediment shows a disposition to settle near the cork. The younger the wine the longer the period necessary for the bottles to be shaken, new wine often requiring as much as three months. Only a thoroughly practised hand can give the right amount of revolution and the requisite degree of slope; and in some of the cellars men were pointed out to us who had acquired such dexterity as to be able at a pinch to shake with their two hands as many as 50,000 bottles in a single day, whilst 30,000 to 40,000 is by no means an uncommon performance. [Illustration] Some of these men have spent thirty or forty years of their lives engaged in this perpetual task. Fancy being entombed all alone day after day in vaults which are invariably dark and gloomy, and often cold and dank, and being obliged to twist sixty to seventy of these bottles every minute throughout the day of ten hours! Why, the treadmill and the crank, with their periodical respites, must be pastime compared to this maddeningly monotonous occupation, which combines hard labour, with the wrist, at any rate, with next to solitary confinement. One can understand these men becoming gloomy and taciturn, and affirming that they sometimes see devils hovering over the bottle-racks and frantically shaking the bottles beside them, or else grinning at them as they pursue their humdrum task. Still it may be taken for granted that the men who reach this stage are accustomed to drink freely of raw spirits, as an antidote to the damp to which they are exposed, and merely pay the penalty of their over-indulgence. [Illustration] In former times the bottles used to be placed with their heads downwards on tables pierced with holes, from which they had to be removed and agitated. At a still earlier date the process was more or less successfully accomplished by holding the bottles upside down by the neck, tapping them at the bottom to detach the sediment, and then, after shaking them well up, laying them on their sides until the operation was repeated. In 1818, however, a man named Müller, in the employment of Madame Clicquot, suggested that the bottles should remain in the tables whilst being shaken, and further that the holes should be cut obliquely, so that they might recline at varying angles. His suggestions were privately adopted by Madame Clicquot; but eventually the improved plan got wind, and the system which he initiated now prevails throughout the Champagne.[415] [Illustration] When the bottles have gone through their regular course of shaking, they are examined before a lighted candle to ascertain whether the deposit has all fallen on to the cork, and the wine has become perfectly clear. Sometimes it happens that, twist these men never so wisely, the deposit, instead of becoming flaky or granular, refuses to stir, and takes the shape of a bunch of threads technically called a 'claw,' or an adherent membrane styled a 'mask.' When this is the case an attempt is made to start it by tapping the part to which it adheres with a piece of iron, the result being frequently the sudden explosion of the bottle in the workman's hands. By way of precaution, therefore, the operator protects his face with a wire mask, or by gigantic wire spectacles, which give to him a ghoul-like aspect. Frequently it is found impossible to detach the 'mask' from the side of the bottle, and in this case the only thing that remains is to pour the wine back again into the cask, with the view of mixing it in some future _cuvée_.[416] [Illustration] The cellars of the Champagne manufacturers are very varied in character. The wine that has been grown on the chalky hills is left to develop itself in vaults burrowed out of the calcareous strata which underlie the entire district. In excavating these cellars the sides and roofs are frequently worked smooth and regular as finished masonry. The larger ones are composed of a number of spacious and lofty galleries, sometimes parallel with each other, but often ramifying in various directions, and evidently constructed on no definite plan. They are of one, two, and, in rare instances, of three stories, and now and then consist of a series of parallel galleries communicating with each other, lined with masonry, and with their stone walls and vaulted roofs resembling the crypt of some conventual building. Others of ancient date are less regular in their form, being merely so many narrow, low, winding corridors, varied, perhaps, by recesses hewn roughly out of the chalk, and resembling the brigands' cave of melodrama; while a certain number of the larger cellars at Reims are simply abandoned quarries, the broad and lofty arches of which are suggestive of the nave and aisles of some Gothic church. In these varied vaults, lighted by solitary lamps in front of metal reflectors, or by the flickering tallow candles which we carry in our hands, we pass rows of casks filled with last year's vintage or reserved wine of former years, and piles after piles of bottles of _vin brut_ in seemingly endless sequence--squares, so to speak, of raw recruits for the historically famous 'Regiment de Champagne'[417]--awaiting their turn to be thoroughly drilled and disciplined. These are varied by bottles reposing neck downwards in racks at different degrees of inclination, according to the progress their education has attained. Reports caused by exploding bottles now and then assail the ear, and as the echo dies away it becomes mingled with the rush of the escaping wine, cascading down the pile, and finding its way across the sloping sides of the floor to the narrow gutter in the centre. The dampness of the floor and the shattered fragments of glass strewn about show the frequency of this kind of accident. [Illustration: DETACHING THE 'MASK' FROM THE SIDES OF THE BOTTLES.] In these subterranean galleries we frequently come upon parties of workmen engaged in transforming the perfected _vin brut_ into Champagne. Viewed at a distance while occupied in their monotonous task, they present in the semi-obscurity a series of picturesque Rembrandt-like studies. One of the end figures in each group is engaged in the important process of _dégorgement_, which is performed when the deposit, of which we have already spoken, has satisfactorily settled in the neck of the bottle. Baskets full of bottles with their necks downwards are placed beside the operator, who stands before a cask set on end, and having a large oval opening in front. This nimble-fingered manipulator seizes a bottle, raises it for a moment before the light to test the clearness of the wine and the subsidence of the deposit; holds it horizontally in his left hand, with the neck directed towards the opening already mentioned; and with a jerk of the steel hook which he holds in his right hand loosens the agrafe securing the cork. Bang goes the latter, and with it flies out the sediment and a small glassful or so of wine, further flow being checked by the workman's finger, which also serves to remove any sediment yet remaining in the bottle's neck. Like many other clever tricks, this looks very easy when adroitly performed, though a novice would probably allow the bottle to empty itself by the time he discovered that the cork was out. Yet such is the dexterity acquired by practice that the average amount of wine, foam, and deposit ejected by this operation does not exceed one-fourteenth of the contents of the bottle. Occasionally a bottle bursts in the _dégorgeur's_ hand, and his face is sometimes scarred from such explosions. The sediment removed, the _dégorgeur_ slips a temporary cork into the bottle, or places the latter in a machine provided with fixed gutta-percha corks and springs for securing the bottles firmly in their places. The wine is now ready for the important operation of the _dosage_, upon the nature and amount of which the character of perfected Champagne, whether it be dry or sweet, light or strong, very much depends.[418] [Illustration] Different manufacturers have different recipes for the composition of this syrup, all more or less complex in character, and varying with the quality of the wine and the country for which it is intended; but the genuine liqueur consists of nothing but old wine of the best quality, to which a certain amount of sugar-candy and perhaps a dash of the finest cognac spirit has been added.[419] The saccharine addition varies according to the market for which the wine is destined: thus the high-class English buyer demands a dry Champagne, the Russian a wine sweet and strong as 'ladies' grog,' and the Frenchman and German a sweet light wine. To the extra-dry Champagnes a modicum dose is added, while the so-called '_brut_' wines receive no more than from one to three per cent of liqueur.[420] [Illustration] In establishments wedded to old-fashioned usages the dose is administered with a tin can or ladle; but more generally an ingenious machine which regulates the percentage of liqueur to a nicety is employed. The bottle being usually nearly full when passed to the _doseur_, he, when a heavy percentage of liqueur has to be administered, is constrained, under the old system, to pour out some of the wine to make room for it, and this surplus in many cases is afterwards transformed into the well-known _tisane de Champagne_. As soon as the _dosage_ is accomplished, the bottle is passed to another workman known as the _égaliseur_, who fills it up with pure wine, frequently with a part of that which has been poured out by the _doseur_, to the requisite level for corking. In the event of a pink Champagne being required, the wine thus added will be red, although manufacturers of questionable reputation sometimes employ the solution of elderberries, known as _teinte de Fismes_, to impart that once-favourite roseate hue which has been compared to the glow of fading sunlight on a crystal stream. [Illustration: THE DOSEUR.] [Illustration: THE CORKER.] [Illustration: THE METTEUR DE FIL.] [Illustration: DOSING MACHINE.] [Illustration: CORKING MACHINE.] The _égaliseur_ in his turn hands the bottle to the corker, who places it under a machine furnished with a pair of claws (so as to compress the cork to a size sufficiently small to allow it to enter the neck of the bottle) and a suspended weight, which in falling drives it home. These corks, principally obtained from Catalonia and Andalucia, are bound to possess a close and regular fibre and perfect elasticity. They form no unimportant item in the Champagne manufacturer's budget, costing upwards of twopence each, and are delivered in huge sacks resembling hop-pockets. Previous to being used they are either boiled in wine or soaked in a solution of tartar, or else they have been steamed by the cork merchants, in order to prevent their imparting a bad flavour to the wine, and to hinder any leakage. They are commonly handed warm to the corker, who dips them into a small vessel of wine before making use of them. Some firms, however, prepare their corks by subjecting them to cold-water _douches_ a day or two beforehand. The _ficeleur_ receives the bottle from the corker, and with a twist of the fingers secures the cork with string, at the same time rounding its hitherto flat top, at a rate which allows from a thousand to twelve hundred bottles to pass through his hands in course of the day. The _metteur de fil_ next affixes the wire with like celerity;[421] and then the final operation is performed by a workman seizing a couple of bottles by the neck and whirling them round his head, as though engaged in the Indian-club exercise, in order to secure a perfect amalgamation of the wine and the liqueur. [Illustration] The final manipulation accomplished, the agitated course of existence through which the wine has been passing at last comes to an end, and the bottles are conveyed to another part of the establishment, where they repose for several days, or even weeks, in order that the mutual action of the wine and the liqueur upon each other may be complete. When the time arrives for despatching them, they are confided to feminine hands to have their dainty toilettes made, and are tastefully labelled, and are either capsuled, or else have their corks and necks imbedded in sealing-wax or swathed in gold or silver foil, whereby they are rendered presentable at the best-appointed tables. All that now remains is to wrap them up in coloured tissue-paper, to slip them into straw envelopes, or encircle them with wisps of straw, and pack them either in cases or baskets for despatch to all quarters of the civilised globe. [Illustration] It is thus that Champagne sets out on its beneficial pilgrimage to promote the spread of mirth and light-heartedness, to drive away dull care and foment good-fellowship, to comfort the sick and cheer the sound. Wherever civilisation penetrates, Champagne sooner or later is sure to follow; and if Queen Victoria's morning drum beats round the world, its beat is certain to be echoed before the day is over by the popping of Champagne corks. Nowadays the exhilarating wine graces not merely princely but middle-class dinner-tables, and is the needful adjunct at every _petit souper_, as well as the stimulant to the wildest revels in all the gayer capitals of the world. It gives a flush to beauty at garden-parties and picnics, sustains the energies of the votaries of Terpsichore until the hour of dawn, and imparts to many a young gallant the necessary courage to declare his passion. It enlivens the dullest of _réunions_, brings smiles to the lips of the sternest cynics, softens the most irascible tempers, and loosens the most taciturn tongues. The grim Berliner and the gay Viennese both acknowledge the exhilarating influence of the wine. Champagne sparkles in crystal goblets in the great capital of the North, and the Moslem wipes its creamy foam from his beard beneath the very shadow of the mosque of St. Sophia; for the Prophet has only forbidden the use of wine, and of a surety--Allah be praised!--this strangely-sparkling delicious liquor, which gives to the true believer a foretaste of the joys of Paradise, cannot be wine. At the diamond-fields of South Africa and the diggings of Australia the brawny miner who has hit upon a big bit of crystallised carbon, or a nugget of virgin ore, strolls to the 'saloon' and shouts for Champagne. The mild Hindoo imbibes it quietly, but approvingly, as he watches the evolutions of the Nautch girls, and his partiality for the wine has already enriched the Anglo-Bengalee vocabulary and London slang with the word 'simkin.' It is transported on camel-backs across the deserts of Central Asia, and in frail canoes up the mighty Amazon. The two-sworded Daimio calls for it in the tea-gardens of Yokohama, and the New Yorker, when not rinsing his stomach by libations of iced water, imbibes it freely at Delmonico's. Wherever the Romans died they left traces behind them in their quaint funeral urns; wherever the civilised man of the nineteenth century has set his foot--at the base of the Pyramids and at the summit of the Cordilleras, in the mangrove swamps of Ashantee and the gulches of the Great Lone Land, in the wilds of the Amoor and on the desert isles of the Pacific--he has left traces of his presence in the shape of the empty bottles that were once full of the sparkling vintage of the Marne. They are strewn broadcast over the face of the globe, literally from Indus to the Pole. The crews of the Alert and the Discovery left them on the ice-bound verge of the paleocrystic sea; the French expeditionary columns have scattered them within the limits of the Great Sahara. In the lodges of the red man they are found playing the part of a great medicine, and in the huts of the negro they assume all the importance due to a big fetish. Stanley, arriving fainting and exhausted at the mouth of the Congo, hailed with joy the foil-tipped flask that the hospitable merchants who answered his appeal for succour had despatched; and as he quaffed its contents, recalled how he and Livingstone, when thousands of miles from any other European, had emptied a bottle of sparkling Champagne together on the night of their memorable meeting at Ujiji. And when, after the battle of Ulundi, the victorious British troops occupied Cetewayo's kraal, they found within the sable potentate's private chamber several empty Champagne bottles, the contents of which, it is to be presumed, he had quaffed the night before to the success of his followers. In the Transvaal too, during the negotiations for an armistice, Sir Evelyn Wood regaled the Boer delegates with Champagne. On a subsequent occasion, the latter were unable to return the compliment, excusing themselves by suggestively remarking, 'We don't take such things with us when we go to fight.' [Illustration] [Illustration: RENAISSANCE HOUSE AT REIMS, IN WHICH MADAME CLICQUOT RESIDED.] VI. /Reims and its Champagne Establishments./ The city of Reims--Its historical associations--The Cathedral--Its western front one of the most splendid conceptions of the thirteenth century--The sovereigns crowned within its walls--Present aspect of the ancient archiepiscopal city--The woollen manufactures and other industries of Reims--The city undermined with the cellars of the great Champagne firms--Reims hotels--Gothic house in the Rue du Bourg St. Denis--Renaissance house in the Rue de Vesle--Church of St. Jacques: its gateway and quaint weathercock--The Rue des Tapissiers and the Chapter Court--The long tapers used at religious processions--The Place des Marchés and its ancient houses--The Hôtel de Ville--Statue of Louis XIII.--The Rues de la Prison and du Temple--Messrs. Werlé & Co., successors to the Veuve Clicquot-Ponsardin--Their offices and cellars on the site of a former Commanderie of the Templars--Origin of the celebrity of Madame Clicquot's wines--M. Werlé and his son--Remains of the Commanderie--The forty-five cellars of the Clicquot-Werlé establishment--Our tour of inspection through them--Ingenious dosing machine--An explosion and its consequences--M. Werlé's gallery of paintings--Madame Clicquot's Renaissance house and its picturesque bas-reliefs--The Werlé vineyards and vendangeoirs. [Illustration: HEAD OF BACCHUS IN THE COURTYARD OF THE HÔTEL DU LION D'OR.] The ancient city of Reims is pleasantly situate in a spacious natural basin, surrounded by calcareous hills, for the most part planted with vines. It is fertile in historical associations, rich in archæological treasures, and at the same time able to claim the respect more readily accorded in the nineteenth century to a busy and prosperous commercial centre. Indeed, its historical, archæological, and commercial importance is in advance of its actual political situation, for administratively it only ranks as a simple subprefecture in the department of the Marne. The student of history can hardly afford to neglect a city so intimately associated with the story of monarchy in France, and one which has witnessed the coronations of a long series of sovereigns, beginning with Clovis and ending with Charles X. From the day when the 'proud Sicamber' bent his neck at the adjuration of St. Remi, and vowed to adore that which he had burnt and to burn that which he had adored, down to the time when the future exile of Holyrood had his forehead touched by Jean Baptiste Antoine de Latil with the remnant of the 'sacred pomatum' so miraculously saved from revolutionary hands, few of the titular rulers of the country have failed to honour it with their presence. As the Durocortorum of Cæsar, the residence of Charlemagne, the seat of the great Ecclesiastical Councils of the twelfth century, the stronghold of the League, and the scene of one of the first Napoleon's most brilliant feats of arms during the campaign of 1813-14, it has also earned for itself a conspicuous place in history. To Englishmen it is, perhaps, most noteworthy as having successfully checked the victorious advance of the third Edward after Cressy, and witnessed the apogee of that meteoric career, which began in the inn-yard at Domremi and ended in the market-place at Rouen, the career of Jeanne la Pucelle. Nor must it be forgotten that Reims sheltered the childhood of Mary Stuart, and saw the heralds of England hurl solemn defiance at Henri II. in the Abbey of St. Remi, at the command of Mary Tudor. [Illustration: GENERAL VIEW OF REIMS, 1880.] To the archæologist as to the ordinary sightseer, the chief attractions presented by Reims consist in its numerous ecclesiastical edifices, some still serving the purpose for which they were originally erected, others long since converted to secular usages. Most conspicuous among them is the cathedral church of Notre Dame, the stately basilica in which the sovereigns of France were wont to be crowned. This superb monument of Gothic architecture was commenced in 1210, upon the plans of Robert de Coucy, by Archbishop Alberic de Humbert. It was completed at the commencement of the fourteenth century, and though the original design was somewhat modified--owing, it is said, to the contributions of the faithful not coming in with sufficient rapidity--it remains a marvel of strength, admirably combined with grace. The exterior is extremely fine; and the western face, with its elaborately ornate portal, has been described as 'one of the most splendid conceptions of the thirteenth century.'[422] Amidst the almost bewildering multiplicity of ornament, the triple porch, surmounted by a group representing the Coronation of the Virgin, the great rose window, flanked by colossal effigies of David and Goliath, and the range of statues known as the Gallery of the Kings, running across the façade near its summit, are conspicuous. The interior, although fine, and containing many objects of interest, is less impressive, while the plundered treasury can still boast of many quaint and curious relics of bygone times. But the chief interest centres in the fact of the surrounding walls having witnessed so many scenes of stately pomp and pageantry. St. Louis, Philip the Fair, Philip of Valois, the unfortunate John the Good, Charles the Simple, and Charles the Victorious, with Joan of Arc, standard in hand, by his side; the wily Louis XI., Louis the Father of his People, the magnificent Francis I., and his scarcely less magnificent son, the young husband of Mary Queen of Scots; the savage Charles IX., Henri III., with his protest that the crown hurt him, Louis the Just, the Roi Soleil himself, Louis the Well-Beloved, the hapless Louis Seize, and Charles X., have all knelt here in turns whilst the crown was placed on their heads, the sword girded to their sides, and the oriflamme waved above them. Many of the most famous cities of the Middle Ages are mere fossilised representatives of former grandeur, but with Reims the case is otherwise. If somewhat fallen from its former high estate, politically speaking--though it should be remembered that Troyes was the titular capital of the Champagne when the province was ruled by independent Counts--its material prosperity has augmented. Round the nucleus of narrow and often tortuous streets, representing the old archiepiscopal city--the 'Little Rome' of the twelfth century--a network of spacious thoroughfares and broad boulevards has spread itself, and the life and movement of a busy manufacturing population are not lacking. In addition to the wine trade, which of course employs, both directly and indirectly, a large number of hands, Reims is one of the most important seats of the woollen manufacture in France, and the industrial element forms a very important factor amongst its inhabitants. In addition to the flannels, merinoes, blankets, trouserings, shawls, &c., that are annually produced, to the value of from thirty to forty million of francs, there is also a considerable production of gingerbread, biscuits, and dried pears, enjoying a wide-spread reputation. The cellars of the great Champagne manufacturers of Reims are scattered in all directions over the historical old city. They undermine its narrowest and most insignificant streets, its broad and handsome boulevards, and on the eastern side extend beyond its more distant outskirts. In whichever direction we may elect to proceed when visiting the principal Champagne establishments, our starting-point will necessarily be the vicinity of the Cathedral, for it is here that all the hotels are situated. Facing the great western doorway of the ancient Gothic edifice is the Hôtel Lion d'Or, formerly the Hôtel Petit Moulinet, where the allied sovereigns sojourned on their way to Paris in 1814, and Napoleon rested on his flight after the battle of Waterloo. Close by is the Hôtel Maison Rouge, with the commemorative tablet on its renovated façade setting forth that in the year 1429, at the coronation of Charles VII. in this hostelry, then named the Striped Ass, the father and mother of Jeanne Darc were lodged at the expense of the city council. Almost facing is the newly-erected Grand Hôtel, and on the north-western side of the Cathedral is the Hôtel de Commerce, the resort, as its name implies, of most of the commercial travellers frequenting the capital of the Champagne. The visitor to Reims, be his object business or pleasure, is bound to put up at one or other of these four hostelries, and hence the starting-point of his peregrinations is necessarily the same. [Illustration: GOTHIC DOORWAY IN THE RUE DU BOURG ST. DENIS, REIMS.] Proceeding along the Rue Tronçon Ducoudray, we reached the Rue de Vesle, where the Palais de Justice and the new theatre are situated. In the adjacent Rue du Bourg St. Denis is an old house--the ground-floor of which is a wine-shop styled Buvette du Théâtre--notable for its antique Gothic doorway, containing, within the upper portion of the arch, the bas-relief of a man fighting with a bear. There is a tradition that on this spot formerly stood a hospital dedicated to St. Hubert, and intended for the reception of persons wounded when hunting, or who might have chanced to be bitten by mad dogs. In the Rue de Vesle is another old house with an ornamental frieze surmounting its façade, which looks on to one of the entrances of the Church of St. Jacques. This edifice, originally erected at the close of the twelfth century, is hemmed in on all sides by venerable-looking buildings, while above them rises its tapering steeple, surmounted by a mediæval weathercock in the form of an angel. The interior of the church presents a curious jumble of architectural styles from early Gothic to late Renaissance. One noteworthy object of art which it contains is a life-size crucifix carved by Pierre Jacques, a Remois sculptor of the days of the Good King Henri, and from an anatomical point of view a perfect _chef-d'[oe]uvre_. [Illustration: FRIEZE OF OLD HOUSE IN THE RUE DE VESLE, REIMS.] [Illustration: GATEWAY OF THE CHURCH OF ST. JACQUES, REIMS.] [Illustration: WEATHERCOCK OF THE CHURCH OF ST. JACQUES.] The Rue de Vesle merges into the Rue des Tapissiers, where in former times the carpet manufacturers of Reims had their warehouses. In the fourteenth and fifteenth centuries the carpets of Reims were as famous in France as those of Aubusson are to-day, but subsequently they began to decline. Half-way up this street--where, by the way, in 1694 the first numbers of the _Gazette de France_, the oldest existing French newspaper, were printed, the news being duly forwarded from Paris--we pass the ancient gateway leading to the chapter-court of the Cathedral. Within the court a weekly market of small wares is now held; but in the days when the archbishops, dukes, and peers of Reims wielded sovereign sway in the capital of the Champagne, this open space was a _champ clos_, where trials by battle took place. The surrounding buildings comprised residences for various ecclesiastics connected with the Cathedral, together with a small farm whence these epicurean priests derived their supply of fresh milk and fatted capons. According to ancient custom, the inhabitants of the houses facing the chapter-gateway were required to keep their doors and windows open on days of religious processions, the tapers carried by the clergy on these occasions being of such immoderate length that it was necessary to incline them, and run them into the doors and windows of the houses opposite when the bearers passed under the archway. [Illustration: GOTHIC HOUSE IN THE MARKET-PLACE, REIMS.] At the end of the Rue des Tapissiers is the handsome Place Royale, connected with the Place des Marchés by a broad rectangular street lined with lofty edifices in the modern Parisian style of architecture. A break ensues in this range of massive-looking buildings as we enter the ancient Place des Marchés, the forum of Roman Reims, and to-day bordered more or less by houses of a mediæval character, remarkably well preserved. Principal among these is a Gothic timber-house of the fifteenth century, with its projecting upper stories supported by elaborately-carved corbels, and its entire façade enriched with mouldings and finials, and with columns and capitals overlaid with sculptured ornaments. [Illustration: STATUE OF LOUIS XIII. ON THE HÔTEL DE VILLE, REIMS.] Some little distance beyond the Place des Marchés is the Place de l'Hôtel de Ville, which derives all its interest from the handsome-looking edifice in the florid Italian style of the early part of the seventeenth century which gives it its name. The façade of this building is profusely decorated with Ionic, Doric, and Corinthian columns, and on the pediment above the principal entrance is a bas-relief equestrian statue of Louis XIII., whom the Latin inscription beneath fulsomely characterises as 'the just, the pious, the victorious, the clement, the beloved of his people, the terror of his enemies, and the delight of the world,' and to whom 'the senate and inhabitants of Reims have raised this imperishable trophy.' Some century and a half later, however, the imperishable trophy got hurled down and shattered into fragments by the populace, and its vacant place was only filled by the present statue in the year 1818. To the right of the Place is the Chambre des Notaires of Reims, raised on the site of the ancient _présidial_, or court of justice, where the city magistrates used to be elected during the Middle Ages, and to which a chapel and a prison were attached. The latter building evidently gave its name to the adjoining Rue de la Prison, the gloomy-looking houses of which--of a more massive character than the gabled structures of the market-place and the Rue de l'Etape--with their formidably-barred windows, possible relics of the religious wars, seem to frown, as it were, upon the passer-by. In a narrow tortuous street leading from this thoroughfare Messrs. Werlé & Co., the successors of the famous Veuve Clicquot-Ponsardin, have their offices and cellars, on the site of a former Commanderie of the Templars; and strangers passing by this quiet spot would scarcely imagine that under their feet hundreds of busy hands are incessantly at work, disgorging, dosing, shaking, corking, storing, wiring, labelling, capsuling, waxing, tinfoiling, and packing hundreds of thousands of bottles of Champagne destined for all parts of the civilised world. The house of Clicquot, established in the year 1798 by the husband of La Veuve Clicquot-Ponsardin, who died in 1866, in her 89th year, was indebted for much of the celebrity of its wine to the lucky accident of the Russians occupying Reims in 1814 and 1815, and freely requisitioning the sweet Champagne stored in the widow's capacious cellars. Madame Clicquot's wines were slightly known in Russia prior to this date; but the officers of the invading army, on their return home, proclaimed their merits throughout the length and breadth of the Muscovite Empire, and the fortune of the house was made. Madame Clicquot, as every one knows, amassed enormous wealth, and succeeded in marrying both her daughter and granddaughter to counts of the _ancien régime_. The present head of the firm is M. Werlé, who comes of an old Lorraine family although born in the ancient free imperial town of Wetzlar on the Lahn, where Goethe lays the scene of his 'Sorrows of Werther,' the leading incidents of which really occurred there. M. Werlé entered the establishment which he has done so much to raise to its existing position so far back as the year 1821. His care and skill, exercised for nearly two-thirds of a century, have largely contributed to obtain for the Clicquot brand that high repute which it enjoys to-day all over the world. M. Werlé, who has long been naturalised in France, was for many years Mayor of Reims and President of its Chamber of Commerce, as well as one of the deputies of the Marne to the Corps Législatif. He enjoys the reputation of being the richest man in Reims, and, like his late partner, Madame Clicquot, he has also secured brilliant alliances for his children, his son, M. Alfred Werlé, having married the daughter of the Duc de Montebello, while his daughter espoused the son of M. Magne, Minister of Finance under the Second Empire. [Illustration: HEADS OF PH[OE]BUS AND BACCHUS.] Half-way down the narrow Rue du Temple is an ancient gateway, on which may be traced the half-effaced sculptured heads of Ph[oe]bus and Bacchus. Immediately in front is a green _porte-cochère_ forming the entrance to the Clicquot-Werlé establishment, and conducting to a spacious trim-kept courtyard, set off with a few trees, with some extensive stabling and cart-sheds on the left, and on the right hand the entrance to the cellars. Facing us is an unpretending-looking edifice, where the firm has its counting-houses, with a little corner tower surmounted by a characteristic weathercock consisting of a figure of Bacchus seated astride a cask beneath a vine-branch, and holding up a bottle in one hand and a goblet in the other. The old Remois Commanderie of the Knights Templars existed until the epoch of the Great Revolution, and today a few fragments of the ancient buildings remain adjacent to the 'celliers' of the establishment, which are reached through a pair of folding-doors and down a flight of stone steps. The date of the foundation of this Commanderie is uncertain, but it is known that a Templar's church occupied a portion of the site in 1170. In 1311 both the church and the Commanderie passed into possession of the Order of St. John of Jerusalem, which held them until the epoch of the Revolution. Formerly the _échevins_ of Reims used to be elected in the ancient hall of the Commanderie, which at one period was a sanctuary for debtors, and also for criminals. Early in the present century the buildings were sold and demolished. [Illustration: THE CLICQUOT-WERLÉ ESTABLISHMENT AT REIMS.] [Illustration] [Illustration: Arms of the Dauphins of France. Arms of the Knight of Malta. DEVICES FROM THE COMMANDERIE AT REIMS.] After being furnished with lighted candles, we set out on our tour of inspection of the Clicquot-Werlé establishment, entering first of all the vast cellar of St. Paul, where the thousands of bottles requiring to be daily shaken are reposing necks downward on the large perforated tables which crowd the apartment. It is a peculiarity that each of the Clicquot-Werlé cellars--forty-five in number, and the smallest among them a vast apartment--has its special name. In the adjoining cellar of St. Matthew other bottles are similarly arranged, and here wine in cask is likewise stored. We pass rows of huge tuns, each holding its twelve or thirteen hundred gallons of fine reserved wine designed for blending with more youthful growths; next, are threading our way between seemingly endless piles of hogsheads filled with later vintages, and anon are passing smaller casks containing the syrup with which the _vin préparé_ is dosed. At intervals we come upon some square opening in the floor through which bottles of wine are being hauled up from the cellars beneath in readiness to receive their requisite adornment before being packed in baskets or cases, according to the country to which they are destined to be despatched. To Russia the Clicquot Champagne is sent in cases containing sixty bottles, while the cases for China contain as many as double that number. [Illustration: REMAINS OF THE COMMANDERIE AT REIMS.] The ample cellarage which the house possesses has enabled M. Werlé to make many experiments which firms with less space at their command would find it difficult to carry out on the same satisfactory scale. Such, for instance, is the system of racks in which the bottles repose while the wine undergoes its diurnal shaking. Instead of these racks being, as is commonly the case, at almost upright angles, they are perfectly horizontal, which, in M. Werlé's opinion, offers a material advantage, inasmuch as the bottles are all in readiness for disgorging at the same time, instead of the lower ones being ready before those above, as is the case when the ancient system is followed, owing to the uppermost bottles getting less shaken than the others. After performing the round of the celliers we descend into the _caves_, a complete labyrinth of gloomy underground corridors excavated in the bed of chalk which underlies the city, and roofed and walled with solid masonry, more or less blackened by age. In one of these cellars we catch sight of rows of workpeople engaged in the operation of dosing, corking, securing, and shaking the bottles of wine which have just left the hands of the _dégorgeur_ by the dim light of half-a-dozen tallow-candles. The latest invention for liqueuring the wine is being employed. Formerly, to prevent the carbonic acid gas escaping from the bottles while the process of liqueuring was going on, it was necessary to press a gutta-percha ball connected with the machine, in order to force the escaping gas back. The new machine, however, renders this unnecessary, the gas, by its own power and composition, forcing itself back into the wine. In the adjoining cellar of St. Charles are stacks of bottles awaiting the manipulation of the _dégorgeur_; while in that of St. Ferdinand men are engaged in examining other bottles before lighted candles, to make certain that the sediment is thoroughly dislodged, and the wine perfectly clear before the disgorgement is effected. Here, too, the corking, wiring, and stringing of the newly-disgorged wine are going on. Another flight of steps leads to the second tier of cellars, where the moisture trickles down the dank dingy walls, and save the dim light thrown out by the candles we carried, and by some other far-off flickering taper, stuck in a cleft stick, to direct the workmen, who with dexterous turns of their wrists, give a twist to the bottles, all is darkness. On every side bottles are reposing in various attitudes, the majority in huge square piles on their sides, others in racks slightly tilted; others, again, almost standing on their heads, while some, which through overinflation have come to grief, litter the floor and crunch beneath our feet. Tablets are hung against each stack of wine indicating its age, and from time to time a bottle is held up before the light to show us how the sediment commences to form, or to explain how it eventually works its way down the neck of the bottle, and finally settles on the cork. Suddenly we are startled by a loud report, resembling a pistol-shot, which reverberates through the vaulted chamber, as a bottle close at hand explodes, dashing out its heavy bottom as neatly as though it had been cut by a diamond, and dislocating the necks and pounding-in the sides of its immediate neighbours. The wine trickles down, and eventually finds its way along the sloping sides of the slippery floor to the narrow gutter in the centre. [Illustration: MADAME VEUVE CLICQUOT AT EIGHTY YEARS OF AGE (From the painting by Léon Coignet).] Ventilating shafts pass from one tier of cellars to the other, enabling the temperature in a certain measure to be regulated, and thereby obviate an excess of breakage. M. Werlé estimates that the loss in this respect during the first eighteen months of a cuvée amounts to 7 per cent, but subsequently is considerably less. In 1862 one Champagne manufacturer lost as much as 45 per cent of his wine by breakages. The Clicquot cuvée is made in the cave of St. William, where 120 hogsheads of wine are hauled up by means of a crane, and discharged into the vat daily as long as the operation lasts. The tirage, or bottling of the wine, ordinarily commences in the middle of May, and occupies fully a month. M. Werlé's private residence is close to the establishment in the Rue du Temple, and here he has collected a small gallery of high-class modern paintings by French and other artists, including Meissonier's 'Card-players,' Delaroche's 'Beatrice Cenci on her way to Execution,' Fleury's 'Charles V. picking up the brush of Titian,' various works by the brothers Scheffer, Knaus's highly-characteristic _genre_ picture, 'His Highness on a Journey,' and several fine portraits, among which is one of Madame Clicquot, painted by Léon Coignet, when she was eighty years of age, and another of M. Werlé by the same artist, regarded as a _chef-d'[oe]uvre_. Before her father's death Madame Clicquot used to reside in the Rue de Marc, some short distance from the cellars in which her whole existence centred, in a handsome Renaissance house, said to have had some connection with the row of palaces that at one time lined the neighbouring and then fashionable Rue du Tambour. This, however, is extremely doubtful. A number of interesting and well-preserved bas-reliefs decorate one of the façades of the house looking on to the court. The figures are of the period of François Premier and his son Henri II., who inaugurated his reign with a comforting edict for the Protestants, ordaining that blasphemers were to have their tongues pierced with red-hot irons, and heretics to be burnt alive, and who had the ill-luck to lose his eye and life through a lance-thrust of the Comte de Montgomerie, captain of his Scotch guards, whilst jousting with him at a tournament held in honour of the marriage of his daughter Isabelle with the gloomy widower of Queen Mary of England, of sanguinary fame. [Illustration] [Illustration] [Illustration] The first of these bas-reliefs represents two soldiers of the Swiss guard, the next a Turk and Slav tilting at each other, and then comes a scroll entwined round a thistle, and inscribed with this enigmatical motto: 'Giane le sur ou rien.' In the third bas-relief a couple of passionate Italians are winding up a gambling dispute with a hand-to-hand combat, in the course of which table and cards have got canted over; the fourth presents us with two French knights, armed _cap-à-pie_, engaged in a tourney; while in the fifth and last a couple of German lansquenets essay their gladiatorial skill with their long and dangerous weapons. Several years back a tablet was discovered in one of the cellars of the house, inscribed 'Ci-gist vénérable religieux maistre Pierre Derclé, docteur en théologie, jadis prieur de céans. Priez Dieu pour luy. 1486,' which would almost indicate that the house had originally a religious character, although the warlike spirit of the bas-reliefs decorating it renders any such supposition with regard to the existing building untenable. We should mention that the spaces above the _porte cochère_, and the window by its side, are occupied by four medallions, which present that curious mingling of classic and contemporary styles for which the epoch of the Renaissance was remarkable. [Illustration: MEDALLIONS FROM MADAME CLICQUOT'S HOUSE.] The Messrs. Werlé own numerous acres of vineyards, comprising the very finest situations in the well-known districts of Verzenay, Bouzy, Le Mesnil, and Oger, at all of which places they have vendangeoirs or pressing-houses of their own. Their establishment at Verzenay contains seven presses, that at Bouzy eight, at Le Mesnil six, and at Oger two, in addition to which grapes are pressed under their own supervision at Ay, Avize, and Cramant, in vendangeoirs belonging to their friends. Since the death of Madame Clicquot the legal style of the firm has been 'Werlé & Co., successors to Veuve Clicquot-Ponsardin,' the mark, of which M. Werlé and his son are the sole proprietors, still remaining 'Veuve Clicquot-Ponsardin,' while the corks of the bottles are branded with the words 'V. Clicquot-P. Werlé,' encircling the figure of a comet. The style of the wine--light, delicate, elegant, and fragrant--is familiar to all connoisseurs of Champagne. What, however, is not equally well known is that within the last few years the firm, in obedience to the prevailing taste, have introduced a perfectly dry wine of corresponding quality to the richer wine which made the fortune of the house, and gave enduring fame to the Clicquot brand. [Illustration] [Illustration: THE PLACE ROYALE AT REIMS.] VII. /Reims and its Champagne Establishments/ _(continued)_. The house of Louis Roederer founded by a plodding German named Schreider--The central and other establishments of the firm--Ancient house in the Rue des Elus--The gloomy-looking Rue des Deux Anges and prison-like aspect of its houses--Inside their courts the scene changes--Handsome Renaissance house and garden, a former abode of the canons of the Cathedral--The Place Royale--The Hôtel des Fermes and the statue of the 'wise, virtuous, and magnanimous Louis XV.'--Birthplace of Colbert in the Rue de Cérès--Quaint Adam and Eve gateway in the Rue de l'Arbalète--Heidsieck & Co.'s central establishment in the Rue de Sedan--Their famous 'Monopole' brand--The firm founded in the last century--Their extensive cellars inside and outside Reims--The matured wines shipped by them--The Boulevard du Temple--M. Ernest Irroy's cellars, vineyards, and vendangeoirs--Recognition by the Reims Agricultural Association of his plantations of vines--His wines and their popularity at the best London clubs--Various Champagne firms located in this quarter of Reims--The Rue du Tambour and the famous House of the Musicians--The Counts de la Marck assumed former occupants of the latter--The Brotherhood of Minstrels of Reims--Périnet & Fils' establishment in the Rue St. Hilaire--Their cellars of three stories in solid masonry--Their soft, light, and delicate wines--A rare still Verzenay--The firm's high-class Extra Sec. [Illustration] The house of Louis Roederer, originally founded by a plodding German named Schreider, was content to pursue the sleepy tenor of its way for some years--until indeed it suddenly felt prompted to lay siege to the Muscovite connection of La Veuve Clicquot-Ponsardin, and secure a market for its wine at Moscow and St. Petersburg. It next opened up the United States, and finally introduced its brand into England. The house possesses cellars in various parts of Reims, and has its offices in one of the oldest quarters of the city--namely, the Rue des Elus, or ancient Rue des Juifs, where the old synagogue formerly stood, and the records of which date as far back as 1103. At the corner of this street, and abutting on the Place des Marchés, is a curious old house, the overhanging upper stories of which are supported by huge massive carved brackets, decorated with figures more or less quaint in design. M. Louis Roederer's offices in the Rue des Elus are at the farther end of a courtyard, beyond which is found a second court, where carts laden with cases of Champagne seem to indicate that some portion of the shipping business of the house is here carried on. Several requests made by us for permission to visit M. Louis Roederer's establishments having been refused, it is only of their external appearance that we are competent to speak. One of them, in the Boulevard du Temple, is distinguished by a rather imposing façade, and has a carved head of Bacchus surmounting its _porte-cochère_; while the principal establishment, a picturesque range of buildings of considerable extent, is situated in the neighbouring Rue de la Justice. [Illustration: OLD HOUSE AT THE CORNER OF THE RUE DES ÉLUS AND THE PLACE DES MARCHÉS, REIMS.] Leading from the Rue des Elus into the Rue de Vesle is a gloomy-looking ancient street known as the Rue des Deux Anges, all the houses of which have their windows secured by iron gratings, and their massive doors thickly studded with huge nails. These prison-like façades, which in all probability refer to the epoch of the religious wars, succeed each other in lugubrious monotony along either side of the way; but gain admittance to their inner courts, and quite a different scene presents itself. In one notable instance, looking on to a pleasant little flower-garden, we found a small but charming Renaissance house, with its windows ornamented with elaborate mouldings, and surmounted by graceful sculptured heads, while at one corner there rose up a tower with a sun-dial displayed on its front. In this and in an adjoining house the canons of the cathedral were accustomed to reside in the days when something like four-fifths of the city were the property of the Church. [Illustration: RENAISSANCE HOUSE IN THE RUE DES DEUX ANGES, REIMS.] Proceeding along the Rue de Vesle and the neighbouring Rue des Tapissiers, we find ourselves once more in the Place Royale, the principal side of which is occupied by the once notable Hôtel des Fermes, where, in the days of the _ancien régime_, the farmers-general of the Champagne were accustomed to receive the revenues of the province. A bronze statue rises in the centre of the Place, which from its Roman costume and martial bearing might be taken for some hero of antiquity, did not the inscription on the pedestal apprise us that it is intended for the 'wise, virtuous, and magnanimous Louis XV.,' a misuse of terms which has caused a Transatlantic Republican to characterise the monument as a brazen lie. Leading out of the Place Royale is the Rue de Cérès, in which there is a modernised sixteenth-century house claiming to be the birthplace, on the 29th August 1619, of Jean Baptiste Colbert, son of a Reims wool-merchant, and the famous minister who did so much to consolidate the finances of the State which the royal voluptuary, masquerading at Reims in Roman garb, afterwards made such dreadful havoc of. [Illustration: HEADS SURMOUNTING THE PRINCIPAL WINDOWS OF THE RENAISSANCE HOUSE IN THE RUE DES DEUX ANGES.] [Illustration: JEAN BAPTISTE COLBERT (From a portrait of the time).] We again cross the Place des Marchés, at the farther end of which, on the left-hand side, is the Rue de l'Arbalète, notable for a curious Renaissance gateway, with its pediment supported by two life-size figures, which the Rémois, for no very sufficient reason, have popularly christened Adam and Eve. Beyond the Place des Marchés and the Place de l'Hôtel de Ville, and at no great distance from the Clicquot-Werlé establishment, is the narrow winding Rue de Sedan, where the old-established firm of Heidsieck & Co., which has secured a high-class reputation in both eastern and western hemispheres for its famous Monopole and Dry Monopole brands, has its central offices. The original firm dates back to 1785, when France was struggling with those financial difficulties that a few years later culminated in that great social upheaving which kept Europe in a state of turmoil for more than a quarter of a century. Among the archives of the firm is a patent, bearing the signature of the Minister of the Prussian Royal Household, appointing Heidsieck & Co. purveyors of Champagne to Frederick William III. The Champagne-drinking Hohenzollern _par excellence_, however, was the son and successor of the preceding, who, from habitual over-indulgence in the exhilarating sparkling beverage during the last few years of his reign, acquired the _sobriquet_ of King Clicquot. [Illustration: ADAM AND EVE GATEWAY, RUE DE L'ARBALÈTE, REIMS.] On passing through the large _porte-cochère_ giving entrance to Messrs. Heidsieck's principal establishment, one finds oneself in a small courtyard, with the surrounding buildings overgrown with ivy and venerable vines. On the left is a dwelling-house enriched with elaborate mouldings and cornices, and at the farther end of the court is the entrance to the cellars, surmounted by a sun-dial bearing the date 1829. The latter, however, is no criterion of the age of the buildings themselves, as these were occupied by the firm at its foundation, towards the close of the last century. We are first conducted into an antiquated-looking low cellier, the roof of which is sustained with rude timber supports, and here bottles of wine are being labelled and packed, although this is but a mere adjunct to the adjacent spacious packing-room, provided with its loading platform and communicating directly with the public road. At the time of our visit this hall was gaily decorated with flags and inscriptions, the day before having been the fête of St. Jean, when the firm entertain the people in their employ with a banquet and a ball, at which the choicest wine of the house liberally flows. From the packing-room we descend into the cellars, which, like all the more ancient vaults in Reims, have been constructed on no regular plan. Here we thread our way between piles after piles of bottles, many of which, having passed through the hands of the disgorger, are awaiting their customary adornment. The lower tier of cellars is mostly stored with _vin sur pointe_, and bottles with their necks downward are encountered in endless monotony along a score or more of long galleries. The only variation in our lengthened promenade is when we come upon some solitary workman engaged in his monotonous task of shaking his 30,000 or 40,000 bottles per diem. The disgorging at Messrs. Heidsieck's takes place, in accordance with the good old rule, in the cellars underground, where we noticed large stocks of wine three and five years old, the former in the first stage of _sur pointe_, and the latter awaiting shipment. It is a specialty of the house to ship only matured wine, which is necessarily of a higher character than the ordinary youthful growths, for a few years have a wonderful influence in developing the finer qualities of Champagne. At the time of our visit, in the spring of 1877, when the English market was being glutted with the crude full-bodied wine of 1874, Messrs. Heidsieck were continuing to ship wines of 1870 and 1872, beautifully rounded by keeping, and of fine flavour and great delicacy of perfume. Of these thoroughly matured wines the firm had fully a year's consumption on hand. Messrs. Heidsieck & Co. have a handsome modern establishment in the Rue Coquebert--a comparatively new quarter of the city, where Champagne establishments are the rule--the courtyard of which, alive with workmen at the time of our visit, is broad and spacious, while the surrounding buildings are light and airy, and the cellars lofty, regular, and well ventilated. In a large cellier here, where the tuns are ranged side by side between the rows of iron columns supporting the roof, the firm make their cuvée. Here, too, the bottling of their wine takes place, and considerable stocks of high-class reserve wines and more youthful growths are stored ready for removal when required by the central establishment. The bulk of Messrs. Heidsieck's reserve wines, however, repose in the outskirts of Reims, near the Porte Dieu-Lumière, in one of the numerous abandoned chalk quarries, which of late years the Champagne manufacturers have discovered are capable of being transformed into admirable cellars. In addition to shipping a rich and a dry variety of the Monopole brand, of which they are sole proprietors, Messrs. Heidsieck export to this country a rich and a dry Grand Vin Royal. It is, however, to their famous Monopole wine, and especially to the dry variety, which must necessarily comprise the finest growths, that the firm owe their principal celebrity. Few large manufacturing towns like Reims--which is one of the most important of those engaged in the woollen manufacture in France--can boast of such fine promenades and such handsome boulevards as the capital of the Champagne. As the ancient fortifications of the city were from time to time razed, their site was levelled and generally planted with trees, so that the older quarters of Reims are almost encircled by broad and handsome thoroughfares, separating the city, as it were, from its outlying suburbs. In or close to the broad Boulevard du Temple, which takes its name from its proximity to the site of the ancient Commanderie of the Templars, various Champagne manufacturers, including M. Louis Roederer, M. Ernest Irroy, and M. Charles Heidsieck, have their establishments; while but a few paces off, in the neighbouring Rue Coquebert, are the large and handsome premises of Messrs. Krug & Co. [Illustration: M. ERNEST IRROY'S ESTABLISHMENT AT REIMS.] The offices of M. Ernest Irroy, who is known in Reims not merely as a large Champagne grower and shipper, but also as a distinguished amateur of the fine arts, taking a leading part in originating local exhibitions and the like, are attached to his private residence, a handsome mansion flanked by a large and charming garden in the Boulevard du Temple. The laying out of this sylvan oasis is due to M. Varé, the head gardener of the city of Paris, who contributed so largely to the picturesque embellishment of the Bois de Boulogne. M. Irroy's establishment, which comprises a considerable range of buildings grouped around two courtyards, is immediately adjacent, although its principal entrance is in the Rue de la Justice. The vast celliers, covering an area of upwards of 3000 square yards, and either stocked with wine in cask or used for packing and similar purposes, afford the requisite space for carrying on a most extensive business. The cellars beneath comprise three stories, two of which are solidly roofed and lined with masonry, while the lowermost one is excavated in the chalk. They are admirably constructed on a symmetrical plan, and their total surface is very little short of 7000 square yards. Spite of the great depth to which these cellars descend, they are perfectly dry, the ventilation is good, and their temperature moreover is remarkably cool, one result of which is that M. Irroy's loss from breakage never exceeds four per cent per annum. M. Irroy holds a high position as a vineyard proprietor in the Champagne, his vines covering an area of nearly ninety acres. At Mareuil and Avenay he owns some twenty-five acres, at Verzenay and Verzy about fifteen, and at Ambonnay and Bouzy close upon fifty acres. His father and his uncle, whose properties he inherited or purchased, commenced some thirty years ago to plant vines on certain slopes of Bouzy possessing a southern aspect, and he has followed their example with such success both at Bouzy and Ambonnay, that the Reims Agricultural Association in 1873 conferred upon him a silver-gilt medal for his plantations of vines, and in 1880 presented him with a _coupe d'honneur_. M. Irroy owns vendangeoirs at Verzenay, Avenay, and Ambonnay; and at Bouzy, where his largest vineyards are, he has built some excellent cottages for his labourers. He has also constructed a substantial bridge over the ravine which, formed by winter torrents from the hills, intersects the principal vineyard slopes of Bouzy. M. Ernest Irroy's wines, prepared with scrupulous care and rare intelligence, have been known in England for some years past, and are steadily increasing in popularity. They are emphatically connoisseurs' wines. The best West-end clubs, such as White's, Arthur's, the old Carlton, and the like, lay down the cuvées of this house in good years as they lay down their vintage ports and finer clarets, and drink them, not in a crude state, but when they are in perfection--that is, in five to ten years' time. M. Irroy exports to the British colonies and to the United States the same fine wines which he ships to England. Several well-known Champagne firms have their establishments in this quarter of Reims. In addition to those already mentioned, we may instance G. H. Mumm & Co., who are located in the Rue Andrieux, only a short distance from the grand triumphal arch known as the Gate of Mars, by far the most important Roman remain of which the Champagne can boast. Within a stone's throw of this arch there formerly stood the ancient château of the Archbishops of Reims, demolished close upon three centuries ago. In the Rue de Mars, a winding ill-paved thoroughfare leading from the Gate of Mars to the Place de l'Hôtel de Ville, Jules Mumm & Co., an offshoot from the once famous firm of P. A. Mumm & Co., are installed; while in a massive and somewhat pretentious-looking house, dating back to the time of Louis Quatorze, in a corner of the Place de l'Hôtel de Ville, Ruinart Père et Fils, who claim to rank as the oldest existing Champagne establishment, have their offices. The late Vicomte de Brimont, the recent head of the firm, was a collateral descendant of the Dom Ruinart, whose remains repose nigh to those of the illustrious Dom Perignon in the abbey church of Hautvillers. From the Place de l'Hôtel de Ville we proceed through the narrow Rue du Tambour, originally a Roman thoroughfare, and during the Middle Ages the locality where the nobility of Reims principally had their abodes. Half-way up this street stands the famous House of the Musicians, one of the most interesting architectural relics of which the capital of the Champagne can boast. It evidently dates from the early part of the fourteenth century, but by whom it was erected is unknown. Some ascribe it to the Knights Templars, others to the Counts of Champagne, while others suppose it to have been the residence of the famous Counts de la Marck, who in later times diverged into three separate branches, the first furnishing Dukes of Cleves and Jülich to Germany, and Dukes of Nevers and Counts of Eu to France; while the second became Dukes of Bouillon and Princes of Sedan, titles which passed to the Turennes when Henri de la Tour d'Auvergne, Vicomte de Turenne, married the surviving heiress of the house. The third branch comprised the Barons of Lumain, allied to the Hohenzollerns. Their most famous member slew Louis de Bourbon, Archbishop of Liège, and flung his body into the Meuse; and subsequently became celebrated as the Wild Boar of the Ardennes, of whom all readers of _Quentin Durward_ will retain a lively recollection. [Illustration: THE HOUSE OF THE MUSICIANS IN THE RUE DU TAMBOUR, REIMS.] To return, however, to the House of the Musicians. A probable conjecture ascribes the origin of the quaint mediæval structure to the Brotherhood of Minstrels of Reims, who in the thirteenth century enjoyed a considerable reputation, not merely in the Champagne, but throughout the North of France. The house takes its present name from five seated statues of musicians, larger than life-size, occupying the Gothic niches between the first-floor windows, and resting upon brackets ornamented with grotesque heads. It is thought that the partially-damaged figure on the left-hand side was originally playing a drum and a species of clarionet. The next one evidently has the remnants of a harp in his raised hands. The third or central figure is supposed merely to have held a hawk upon his wrist; whilst the fourth seeks to extract harmony from a dilapidated bagpipe; and the fifth, with crossed legs, strums complacently away upon the fiddle. The ground-floor of the quaint old tenement is to-day an oil and colour shop, the front of which is covered with chequers in all the tints of the rainbow. Leading from the Rue du Tambour is the Rue de la Belle Image, thus named from a handsome statuette of the Virgin, which formerly decorated a corner niche; and beyond is the Rue St. Hilaire, where Messrs. Barnett et Fils, trading under the designation of Périnet et Fils, and the only English house engaged in the manufacture of Champagne, have an establishment which is certainly as perfect as any to be found in Reims. Above-ground are several large store-rooms, where vintage-casks and the various utensils common to a Champagne establishment are kept; and a capacious cellier, upwards of one hundred and fifty feet in length, with its roof resting on massive timber supports. Here new wine is stored preparatory to being blended and bottled; and in the huge tun, holding nearly three thousand gallons, standing at the further end, the firm make their cuvée; while adjacent is a room where stocks of corks and labels, metal foil, and the like are kept. [Illustration: MESSRS. PÉRINET ET FILS' ESTABLISHMENT IN THE RUE ST. HILAIRE, REIMS.] Underneath this building there are three stories of cellars--an exceedingly rare thing anywhere in the Champagne--all constructed in solid masonry on a uniform plan, each story comprising two wide galleries, running parallel with each other and connected by means of transverse passages. Spite of the great depth to which these cellars descend, they are perfectly dry; the ventilation, too, is excellent; and their different temperatures render them especially suitable for the storage of Champagne, the temperature of the lowest cellar being 6° Centigrade (43° Fahrenheit), or one degree Centigrade below the cellar immediately above, which in its turn is two degrees below the uppermost of all. The advantage of this is that, when the wine develops an excess of effervescence, any undue proportion of breakages can be checked by removing the bottles to a lower cellar, and consequently into a lower temperature. The first cellars we enter are closely stacked with wine in bottle, which is gradually clearing itself by the formation of a deposit; while in an adjoining cellar on the same level the operations of disgorging, liqueuring, and corking are going on. At the end of this gallery is a spacious compartment, where a large stock of _pure Champagne_ cognac of grand vintages is stored for cask and liqueur use. In the cellars immediately beneath, bottles of wine repose in solid stacks ready for the _dégorgeur_; while others rest in racks, in order that they may undergo their daily shaking. In the lowest cellars reserved wine in cask is stored, as it best retains its natural freshness and purity in a very cool place. All air is carefully excluded from the casks; any ullage is immediately replaced; and, as evaporation is continually going on, the casks are examined every fortnight, when any deficiency is at once replenished. At Messrs. Périnet et Fils', as at all the first-class establishments, the _vin brut_ is a _mélange_ comprising the produce of some of the best vineyards, and has every possible attention paid to it during its progressive stages of development. From the second tier of cellars at Messrs. Périnet et Fils' a gallery extends, under the Rue St. Hilaire, to some extensive vaults excavated beneath an adjacent building, in which the Reims Military Club is installed. These vaults, arranged in two separate stories, are eight in number, and in them we found a quarter of a million bottles of _vin brut_, reposing either in solid stacks or _sur pointe_, the latter going through their daily shaking in order to fit them for the operation of _dégorgement_. On the whole the cellars of Périnet et Fils, including the six long galleries already described, suffice for the storage of a million bottles of Champagne. [Illustration: THE CELLIER AND CELLARS OF MESSRS. PÉRINET ET FILS.] Before leaving the establishment Champagnes of different years were shown to us, all of them soft, light, and delicate, and with that fine flavour and full perfume which the best growths of the Marne alone exhibit. Among several curiosities submitted to us was a still Verzenay of the year 1857, one of the most delicate wines it was ever our fortune to taste. Light in body, rich in colour, of a singularly novel and refined flavour, and with a magnificent yet indefinable bouquet, the wine was in every respect perfect. Not only was the year of the vintage a grand one, but the wine must have been made with the greatest possible care, and from the most perfect grapes, for so delicate a growth to have retained its flavour in such perfection, and preserved its brilliant ruby colour for such a length of time. From the samples shown to us of Périnet et Fils' Champagne, we were prepared to find that at some recent tastings in London, the particulars of which have been made public, their Extra Sec took the first place at each of the three severe competitions to which it was subjected. [Illustration: GROTTO BENEATH THE OLD FORTIFICATIONS OF REIMS.] VIII. /Reims and its Champagne Establishments/ _(continued)_. La Prison de Bonne Semaine--Mary Queen of Scots at Reims--Messrs. Pommery & Greno's offices--A fine collection of faïence--The Rue des Anglais a former refuge of English Catholics--Remains of the old University of Reims--Ancient tower and grotto--The handsome castellated Pommery establishment--The spacious cellier and huge carved cuvée tuns--The descent to the cellars--Their great extent--These lofty subterranean chambers originally quarries, and subsequently places of refuge of the early Christians and the Protestants--Madame Pommery's splendid cuvées of 1868 and 1874--Messrs. de St. Marceaux & Co.'s new establishment in the Avenue de Sillery--Its garden-court and circular shaft--Animated scene in the large packing hall--Lowering bottled wine to the cellars--Great depth and extent of these cellars--Messrs. de St. Marceaux & Co.'s various wines--The establishment of Veuve Morelle & Co., successors to Max Sutaine--The latter's 'Essai sur le Vin de Champagne'--The Sutaine family formerly of some note at Reims--Morelle & Co.'s cellars well adapted to the development of sparkling wines--The various brands of the house--The Porte Dieu-Lumière. [Illustration: HEAD OVERSEER AT POMMERY AND GRENO'S.] Nigh the cathedral of Reims, and in the rear of the archiepiscopal palace, there runs a short narrow street known as the Rue Vauthier le Noir, and frequently mentioned in old works relating to the present capital of the Champagne. The discovery of various pillars and statues, together with a handsome Gallo-Roman altar, whilst digging some foundations in 1837, points to the fact that a Pagan temple formerly occupied the site. The street is supposed to have taken its name, however, from some celebrated gaoler, for in mediæval times here stood 'la prison de bonne semaine.' On the site of this prison a château was subsequently built, which tradition has erroneously fixed upon as the residence of the beautiful and luckless Mary Queen of Scots, in the days when her uncle, Cardinal Charles de Lorraine, was Lord Archbishop of Reims. Temple, prison, and palace have alike disappeared, and where they stood there now rises midway between court and garden a handsome mansion, the residence of Madame Pommery, head of the well-known firm of Pommery & Greno. To the left of the courtyard, which is entered through a monumental gateway, are some old buildings, let into the walls of which are a couple of sculptured escutcheons, the one comprising the arms of France, and the other those of the Cardinal de Lorraine. On the right-hand side of the courtyard are the Pommery offices, together with the manager's sanctum, replete with artistic curiosities, the walls being completely covered with remarkable specimens of faïence, including Rouen, Gien, Palissy, Delft, and majolica, collected in the majority of instances by Madame Pommery in the villages around Reims. Here we were received by M. Vasnier, who at once volunteered to accompany us to the cellars of the firm outside the city. Messrs. Pommery & Greno originally carried on business in the Rue Vauthier le Noir, where there are extensive cellars, but their rapidly-increasing connection long since compelled them to emigrate beyond the walls of Reims. [Illustration: OLD COATS OF ARMS IN THE COURTYARD OF MADAME POMMERY'S RESIDENCE.] In close proximity to the Rue Vauthier le Noir is the Rue des Anglais, so named from the English Catholic refugees, who, flying from the persecutions of our so-called Good Queen Bess, here took up their abode and established a college and a seminary. They rapidly acquired great influence in Reims, and one of their number, William Gifford, was even elected archbishop. At the end of this street, nigh to Madame Pommery's, there stands an old house erected late in the fifteenth century, with a corner tower and rather handsome Renaissance window, which formerly belonged to some of the clergy of the cathedral, and subsequently became the 'Bureau Général de la Loterie de France,' an institution abolished by the National Convention in 1793. [Illustration: OLD HOUSE IN THE RUE DES ANGLAIS, REIMS.] The Rue des Anglais conducts into the Rue de l'Université, where a few remnants of the old University, founded by Cardinal Charles de Lorraine (1538-74), formerly attracted attention, notably a conical-capped corner tower, the sculptured ornaments at the base of which had crumbled into dust beneath the corroding tooth of Time.[423] From the Rue de l'Université our way lies along the Boulevard du Temple to the Porte Gerbert, about a mile beyond which there rises up the curious castellated structure in which the Pommery establishment is installed, with its tall towers commanding a view of the whole of Reims and its environs. As we drive up the Avenue Gerbert we espy on the right an isolated crumbling tower, a remnant of the ancient fortifications of Reims,[424] while close at hand, and under the old city-walls, is a grotto, to which an ancient origin is likewise ascribed. In another minute we reach the open iron gates of Messrs. Pommery's establishment, flanked by a picturesque porter's lodge; and proceeding up a broad drive, we alight under a Gothic portico at the entrance to the spacious and lofty cellier. Iron girders support the roof of this vast hall, 180 feet in length and 90 feet in width, without the aid of a single column. At one end is the office and tasting-room, provided with a telegraphic apparatus and telephone, by means of which communication is carried on with the Reims bureaux. Stacked up on every side of the cellier, and often in eight tiers when empty, are rows upon rows of casks, 6000 of which contain wine of the costly vintage of 1880 sufficient for a million and a half bottles of Champagne. The temperature of this hall is carefully regulated; the windows are high up near the roof, and the sun's rays are rigidly excluded, so that a pleasant coolness pervades the building. On the left-hand side stand two huge tuns, with the monogram P. and G., surmounting the arms of Reims, carved on their heads. These are capable of containing 5500 gallons of wine, and in them the firm make their cuvée. A platform, access to which is gained by a staircase in a side aisle, runs round one of these _foudres_; and when the wine, which has been hoisted up in casks and poured through a metal trough into the _foudre_, is being blended, boys stand on this platform and, by means of a handle protruding above the cask, work the paddle-wheels placed inside, thereby securing the complete amalgamation of the wine. Adjoining are the chains and lifts worked by steam, by means of which wine is raised and lowered from and to the cellars beneath, one lift raising or lowering eight casks, whether full or empty, in the space of a minute. [Illustration: THE POMMERY AND GRENO ESTABLISHMENT IN THE OUTSKIRTS OF REIMS.] At the farther end of the hall a Gothic door, decorated with ornamental ironwork, leads to the long broad flight of steps, 116 in number, and nearly twelve feet in width, conducting to the suite of lofty subterranean chambers, where bottles of _vin brut_ repose in their hundreds of thousands in slanting racks or solid piles, passing leisurely through those stages of development necessary to fit them for the _dégorgeur_. Altogether there are 130 large shafts, 90 feet in depth and 60 feet square at their base, which were originally quarries, and are now connected by spacious galleries. This side of Reims abounds with similar chalk quarries, commonly believed to have served as places of refuge for the Protestants at the time of the League and after the revocation of the Edict of Nantes; and it is even conjectured that the early Christians--the followers of St. Sixtus and St. Sinicus--here hid themselves from their persecutors. Since the cellars within the city have no longer sufficed for the storage of the immense stocks required through the development of the Champagne trade, these vast subterranean galleries have been successfully utilised by various firms. Messrs. Pommery, after filling up the chambers above the water level, proceeded to excavate the connecting tunnels, shore up the cracking arches, and repair the flaws in the chalk with masonry, finally converting these abandoned quarries into magnificent cellars for the storage of Champagne. No less than 60,000_l._ was spent upon them and the castellated structure aboveground. Several millions of bottles of Champagne can be stored in these capacious vaults, the area of which is nearly 450,000 square feet. [Illustration: INTERIOR OF MESSRS. POMMERY AND GRENO'S CELLIER.] Madame Pommery made a great mark with her splendid cuvées of 1868 and 1874, the result being that her brand has become widely popular, and that it invariably realises exceptionally high prices. On leaving Messrs. Pommery's we retrace our steps down the Avenue Gerbert, bordered on either side with rows of plane-trees, until we reach the treeless Avenue de Sillery, where Messrs. de St. Marceaux & Co.'s new and capacious establishment is installed. Simple and without pretension, the establishment, which covers an area of upwards of 18,000 feet, is distinguished for its perfect appropriateness to the industry for which it was designed. The principal block of building is flanked by two advanced wings enclosing a garden-court, set off with flowers and shrubs, and from the centre of which rises a circular shaft, covered in with glass, and admitting light and air to the cellars below. In the building to the left the wine is received on its arrival from the vineyard, and here are ranged large quantities of casks replete with the choice crus of Verzenay, Ay, Cramant, and Bouzy, while thousands of bottles ready for labelling are stacked in massive piles at the end of the packing-hall in the corresponding wing of the establishment. Here, too, a tribe of workpeople are arraying the bottles with gold and silver headdresses, and robing them in pink paper, while others are filling, securing, marking, and addressing the cases or baskets destined to Hong-Kong, San Francisco, Yokohama, Bombay, London, New York, St. Petersburg, Berlin, or Paris. [Illustration: THE PACKING-HALL OF MESSRS. DE ST. MARCEAUX AT REIMS.] The wine in cask, stored in the left-hand wing, after having been duly blended in an enormous vat, is drawn off into bottles, which are then lowered down a shaft to the second tier of cellars by means of an endless chain, on to which the baskets of bottles are swiftly hooked. The workman engaged in this duty, in order to guard against his falling down the shaft, has a leather belt strapped round his waist, by means of which he is secured to an adjoining iron column. We descended into the lower cellars down a flight of ninety-three broad steps--a depth equal to the height of an ordinary six-storied house--and found no less than four-and-twenty galleries excavated in the chalk, devoid of masonry supports, and containing upwards of a million bottles of Champagne. These galleries vary in length, but are of uniform breadth, and allow either for a couple of racks with wine _sur pointe_, or stacks of bottles, in four row's on either side, with ample passage-room down the centre. The upper range of cellars comprises two large arched galleries of considerable breadth, one of which contains wine in wood and wine _sur pointe_, while the other is stocked with bottles of wine heads downward, ready to be delivered into the hands of the _dégorgeur_. MM. de St. Marceaux & Co. have the honour of supplying the King of the Belgians, the President of the French Republic, and several German potentates with an exceedingly delicate Champagne known as the Royal St. Marceaux. The same wine is popular in Russia and other parts of Europe, just as the Dry Royal of the firm is much esteemed in the United States. The brand of the house most appreciated in this country is its Carte d'Or, a very dry wine, the extra superior quality of the firm, which secured the first place at a recent Champagne competition in England. Some little distance beyond the remnants of the ancient fortifications of Reims, skirting the Butte de St. Nicaise, is the establishment of Veuve Morelle & Co., successors to Veuve Max Sutaine & Co. This house was founded in 1823 by the late M. Maxime Sutaine, who, like several other notabilities in the Reims wine trade, was as familiar with art and science as with the special industry to which he had devoted himself. An amateur painter of no mean skill, he showed himself thoroughly at home in the biographical and critical notices on artists and art in his native province which he produced. His name, however, is chiefly identified in literature with his _Essai sur le Vin de Champagne_.[425] This work may be regarded as the first attempt to collect the scattered materials relating to the history of Champagne wine, and to deal with them in a critical spirit. Though necessarily imperfect, its value is undoubtedly great, and it has been frequently quoted from in the present volume. The family of Sutaine long held an honourable position at Reims, the name of one of M. Max Sutaine's immediate ancestors, who filled the position of lieutenant of the city in 1765, appearing on the bronze slab at the base of the statue of Louis XV. in the Place Royale, erected during that year. [Illustration: THE CELLARS OF MAX SUTAINE AND CO. IN THE CHEMIN DE LA PROCESSION, REIMS.] The cellars of the firm of Veuve Morelle & Co., successors to Max Sutaine & Co., are very extensive; and while more than usually picturesque in appearance, are in every respect admirably adapted for the rearing and development of the delicate wines of the Champagne. These cellars, hewn out of the chalk, are of great depth. The firm has been careful to adhere to the good traditions of its predecessors in the composition of its cuvées, and at the same time to avoid those errors which experience and the resources of modern science have made manifest. Its rule is only to send out wines of a good cru, and never before they are thoroughly matured, thereby avoiding the shipment of young wines. The chief kinds bearing the brand of Max Sutaine & Co. are Vin Brut (of great years), Extra Dry, Creaming Sillery, and Bouzy for England, Sillery Sec for Russia, and Verzenay and Cabinet for Germany and Belgium. It should be mentioned that of late years the abandoned quarries, so numerous on this side of the city, have been largely utilised by the Reims Champagne manufacturers as cellars for the storage of their wines. Beyond the firms that have been already alluded to as possessing cellars in this direction, there remain to be enumerated Messrs. Kunkelmann & Co., Ruinart Père et Fils, the Goulets, Jules Champion, Théophile Roederer, &c. The cellars of several of the last named are immediately outside the Porte Dieu-Lumière, near which is a seventeenth-century house having let into its face a curious bas-relief, of evidently much earlier date, the subject of which has been a source of considerable perplexity to local antiquaries. A like cloud enshrouds the origin of the name of Dieu-Lumière, bestowed upon the fortified gate formerly standing here, and originally erected during the fourteenth century, when, the circle of the ramparts having been carried round the Bourg de St. Remi so as to unite it to the old city, the Porte St. Nicaise was walled up.[426] Like the other portals of Reims, it has no lack of historical associations. Its vaulted roof resounded with the trampling of barbed war-steeds when, on the 16th July 1429, Charles the Victorious swept beneath it into the city, with Joan of Arc by his side and the steel-clad chivalry of France at his back.[427] The year 1583 saw its keys handed to the Duc de Guise, and the green flag of the League, with its device 'Auspice Christo,' hoisted above it; and twenty-three years later, as Henri Quatre rode through it amidst shouts of welcome, the jesting remark, 'I had no idea I was so well beloved at Reims,' was the only attempt at revenge made by the easy-going Béarnais on the population who had so long flouted his authority. Rebuilt in 1620, it witnessed the triumphant return of Grandpré's cavalry and the Rémois militia, after their victory over Montal and his Spaniards at La Pompelle in 1657, and the successful assault of the renegade Saint Priest, whose Cossacks entered the walls at this point in 1814, and gave way to the most brutal excesses. Nor must it be forgotten that Marie Louise passed through this gate _en route_ for Paris, on which occasion its summit was crowned with elaborate allegorical devices supported by cupids weaving garlands of flowers; or that for several centuries the relics of St. Timotheus and his companions were annually carried through it on Whit-Monday by the clergy of Reims, escorted by a procession of pilgrims, to the scene of the martyrdom of these early Christians at La Pompelle. [Illustration: BAS-RELIEF NEAR THE PORTE DIEU-LUMIÈRE.] [Illustration] IX. /Epernay./ The connection of Epernay with the production of wine of remote date--The town repeatedly burnt and plundered--Hugh the Great carries off all the wine of the neighbourhood--Vineyards belonging to the Abbey of St. Martin in the eleventh, twelfth, and thirteenth centuries--Abbot Gilles orders the demolition of a wine-press which infringes the abbey's feudal rights--Bequests of vineyards in the fifteenth century--Francis I. bestows Epernay on Claude Duke of Guise in 1544--The Eschevins send a present of wine to their new seigneur--Wine levied for the king's camp at Rethel and the strongholds of the province by the Duc de Longueville--Epernay sacked and fired on the approach of Charles V.--The Charles-Fontaine vendangeoir at Avenay--Destruction of the immense pressoirs of the Abbey of St. Martin--The handsome Renaissance entrance to the church of Epernay--Plantation of the 'terre de siége' with vines in 1550--Money and wine levied on Epernay by Condé and the Duke of Guise--Henri Quatre lays siege to Epernay--Death of Maréchal Biron--Desperate battle amongst the vineyards--Triple talent of the 'bon Roy Henri' for drinking, fighting, and love-making--Verses addressed by him to his 'belle hôtesse' Anne du Puy--The Epernay Town Council make gifts of wine to various functionaries to secure their good-will--Presents of wine to Turenne at the coronation of Louis XIV.--Petition to Louvois to withdraw the Epernay garrison that the vintage may be gathered in--The Duke and Duchess of Orleans at Epernay--Louis XIV. partakes of the local vintage at the maison abbatiale on his way to the army of the Rhine--Increased reputation of the wine of Epernay at the end of the seventeenth century--Numerous offerings of it to the Marquis de Puisieux, Governor of the town--The Old Pretender presented at Epernay with twenty-four bottles of the best--Sparkling wine sent to the Marquis de Puisieux at Sillery, and also to his nephew--Further gifts to the Prince de Turenne--The vintage destroyed by frost in 1740--The Epernay slopes at this epoch said to produce the most delicious wine in Europe--Vines planted where houses had formerly stood--The development of the trade in sparkling wine--A 'tirage' of fifty thousand bottles in 1787--Arthur Young drinks Champagne at Epernay at forty sous the bottle--It is surmised that Louis XVI., on his return from Varennes, is inspired by Champagne at Epernay--Napoleon and his family enjoy the hospitality of Jean Remi Moët--King Jerome of Westphalia's true prophecy with regard to the Russians and Champagne--Disgraceful conduct of the Prussians and Russians at Epernay in 1814--The Mayor offers them the free run of his cellars--Charles X., Louis Philippe, and Napoleon III. accept the 'vin d'honneur' at Epernay--The town occupied by German troops during the war of 1870-1. [Illustration] If Reims be the titular capital of the Champagne wine-trade, Epernay can boast of containing the establishments of some of the most eminent firms engaged therein. Its connection with the production of the wines of Champagne is of the remotest. The vineyards stretching for miles around the ancient Sparnacum claim indeed an antiquity far exceeding that of any existing portion of the town itself, which, despite the remote date of its foundation, and the fact that it was a place of considerable importance as early as 445, presents a thoroughly modern aspect. Unlike Reims--so rich in the remains of antiquity--it possesses no mementoes of the days when its lord Eulogius gave it to St. Remi,[428] and he in turn bequeathed it to the Church. [Illustration] The reason is simple, for the history of Epernay may be briefly summed up in the words--fire, pestilence, and pillage. From the days when misfortune first overtook it, after the division of the Frankish monarchy on the death of Clovis, it has been burnt down on half a dozen occasions, repeatedly depopulated by the plague, and captured and sacked times out of number. The contending sovereigns of Austrasia and Neustria alternately obtained forcible possession of it, and the rival counts of Paris and Vermandois snatched it repeatedly from each other's hold, like hungry dogs contending for a bone; whilst the Normans, the Hungarians, the vassals of Charles of Lorraine, and the followers of Otho of Germany added their quota to the work of destruction during the long period of anarchy preceding the establishment of the Capetian race upon the throne of France. The founder of the said race, Hugh the Great, distinguished himself in 947 by plundering the town of Epernay, ravaging the surrounding country, and profiting by the fact that it was vintage-time to carry off all the wine of the neighbourhood.[429] Even during the epoch of comparative tranquillity which prevailed up to the English invasion, Epernay became from time to time the prey of robber knights like Thomas de Marlé and rebellious nobles like Count John of Soissons; and at the commencement of the thirteenth century Count Thibault of Champagne was fain to burn it, in order to prevent it from serving as a rallying-place for the lords who had risen against Queen Blanche and her infant son Louis IX. After the battle of Poitiers it was pillaged by the partisans of Charles the Bad of Navarre; Edward the Black Prince entered it twice as a conqueror; and John of Gaunt exacted a heavy tribute from it. In the struggles which followed the death of Henry V. of England it was again taken and re-taken, partially burnt and utterly ruined, remaining for three years absolutely depopulated after the unwelcome visit paid it by the Duke of Burgundy in 1432. Yet during all these ravages the vineyards clothing the slopes around the town were gradually developed, chiefly by the fostering care of the good fathers of the Abbey of St. Martin. The charter of foundation of this abbey, which was endowed in 1032, makes mention of vineyards amongst its possessions, and they are also spoken of in the confirmation of donations and privileges granted by Pope Eugenius III. in 1145. Count Henry of Champagne in 1179 gave the canons of the abbey the hospital of Epernay, with the fields and vineyards belonging to it; and twenty years later, Abbot Guy purchased from Abbot Noah, of the monastery of the Chapelle aux Planches, near Troyes, the fields, vineyards, house, barn, and garden adjoining the 'ruisseau du Cotheau' at Epernay for 110 livres. In 1203, Parchasius, a canon of Laon, left by will to the abbey the 'vigne du Clozet,' which is still celebrated for the excellence of its products, at Epernay; and in 1217, Abbot Theodoric gave the 'terres de la Croix Boson' at Mardeuil to sundry of the inhabitants of that village, on the condition of planting them with vines and paying a yearly rent of fourteen hogsheads of wine obtained therefrom as vinage. Tithes of wine at Oger, Cuis, Cramant, Monthelon, &c., and the vineyards of Genselin, Beaumont, and Montfelix also figure amongst the possessions of the abbey in the thirteenth century.[430] A certain proportion of the tithes of the 'fields, meadows, and vineyards' owned by the abbey at Epernay was assigned to the dependent priory in the faubourg of Igny-le-Jard by Abbot Richard de Cuys in 1365. The cultivation of the grape seems to have been carried on in even the most distant of the numerous possessions of the abbey, which drew 'rentes de vin' from Chatillon and Dormans; and in 1373 we find Abbot Gilles de Baronne compelling an unfortunate inhabitant of Romains, near Fismes, to demolish forthwith a wine-press he had dared to erect to the prejudice of the 'droits seigneuriaux et bannaux' which the abbey had over that village. The military orders had their share, too; for the Commandery of the Temple at Reims owned at Epernay at the commencement of the fourteenth century a house and some vineyards, still bearing the name of 'Les Tempières.' In 1419, Philippe le Maître and his wife left to the curé of Epernay a little vineyard at Montebon to pay for a yearly mass; and at a somewhat later date, Isabelle la Linotte bequeathed to the abbey the vineyard De la Ronce at Mardeuil.[431] [Illustration: FRANCIS I. (From a portrait of the time).] Indeed, the history of Epernay is most intimately connected with that of its wine, which figures throughout its records as a constant attraction to friends and foes. After the final expulsion of the English, the town gradually recovered its prosperity, and became an appanage of the Dukes of Orleans. At the commencement of the sixteenth century we find Francis I.--to whom it had reverted on the death of Louise of Savoy--presenting it to Claude, Duke of Guise, and the eschevins resolving in 1544 that their new seigneur should be offered 'twenty poinçons of the best wine that can be found in the cellars of the district, and that after the vintage twenty more of the new crop shall be sent to him.'[432] A levy of one hundred poinçons had already been demanded of them for the camp formed by the King at Rethel two years before; and the various strongholds of the province had been freely supplied with wine exacted from Epernay by the Duke de Longueville, lieutenant-governor of the Champagne. [Illustration: THE EMPEROR CHARLES V. (From a portrait of the time).] [Illustration] On the advance of Charles V. in 1544, the Dauphin, afterwards Henri II., following the example successfully set by Anne de Montmorency in Provence, pitilessly sacked the entire district of the Marne, in order that the enemy might find nothing to live on, and stored the product, which included an enormous quantity of wine, in Epernay. The Emperor advanced, meeting with but little opposition, and having taken up his quarters in the Abbey of Avenay, amused himself with building the vendangeoir known as Charles-Fontaine on the adjacent slope, as a testimony of his intention to make, if possible, a permanent sojourn in a province, the vinous products of which he so highly esteemed.[433] But whilst the illustrious patron of Titian and his 'swarthy grave commanders' were snugly tippling the choicest vintages contained in the abbey cellars, and his followers camped outside Epernay were waiting for the hour when they should revel at pleasure on the wine stored in the town, their hopes vanished literally in smoke. For Francis, fearing the town would be unable to hold out, had sent word to Captain Sery to burn it, and destroy the accumulated store of provisions, in order to prevent them falling into the hands of the enemy. This was accordingly done on the 3d September, and amongst the property consumed were the immense pressoirs of the Abbey of St. Martin. In this conflagration the church of Epernay was no doubt also destroyed, as the handsome Renaissance doorway--the sole ancient portion of the existing edifice--was evidently erected in the latter half of the sixteenth century. The misfortunes of the town did not cease with this calamity, for a great pestilence seems to have marked the return of the inhabitants to their ruined dwellings at the epoch of the following vintage.[434] Five years later, six arpents of the 'terre de siege' where the Spaniards had encamped were planted with vines by the Count de Nanteuil-le-Haudouin, and received the name of the Vineyard de la Plante.[435] [Illustration: MARIE STUART, QUEEN OF SCOTS.] [Illustration: RENAISSANCE DOORWAY TO THE CHURCH OF EPERNAY.] [Illustration: ATTACK ON THE HUGUENOTS AT EPERNAY.] As a matter of course, the hapless fate of the town pursued it during the religious wars of the sixteenth century. In 1567 the Huguenots, under Condé, seized on Epernay--then a portion of the appanage of the unfortunate Marie Stuart of Scotland--and exacted a ransom of 10,500 livres, towards which the Abbey of St. Martin contributed 3451 livres, partly in money and partly in wine, calculated at no more than eleven livres the queue. A higher price appears to have ruled on the recapture of the town by the Duke of Guise the same year, when the levy made consisted of 500 pièces of wine, estimated at twenty-four livres the queue.[436] Guise was driven out by the inhabitants in 1588; but after one fruitless assault, the Leaguers under Rosné succeeded in obtaining forcible possession of Epernay four years later. On Henri Quatre laying siege in turn to Epernay in 1592, the vineyards around the town were again literally watered with blood. One notable episode of this siege was the death of Maréchal Biron, the most devoted of Henri's adherents. On the 27th July the King and Biron were returning on horseback from Damery to the camp. As they advanced up the road leading from Mardeuil to the faubourg of Igny, the wind blew off Henri's hat, adorned with the famous white plume, and Biron, picking it up, jestingly placed it upon his own head. At this moment the white plume unluckily caught the eye of Petit, the master gunner of Epernay, and he at once pointed a cannon at it from the Tour Saint Antoine. 'For the Béarnais!' he exclaimed, as he fired; and the ball carried away the head of the Maréchal, to whom Henri was speaking, and upon whose shoulder the King's hand was actually resting. 'Ah, mordieu, the dog has bitten the Béarnais!' cried the exulting gunner, believing it was the King who had fallen, and alluding to the name of the cannon, which was known as the 'Dog of Orleans,' from its having been captured from the English at the siege of that city, and bearing on its breech the figure of a dog.[437] [Illustration] [Illustration: HENRI QUATRE BEFORE EPERNAY.] The death of Maréchal Biron, and the fact that Henri was devoting quite as much attention to his 'belle hôtesse' at Damery, the fair Présidente Anne du Puy, as he was to the siege, encouraged St. Paul, who commanded at Reims for the League, to despatch a strong body of Walloon pikemen and musketeers to the relief of the beleaguered town. They approached by the hollow road leading from the Faubourg des Ponts Neufs to the slope of the Vignes des Capinets, and passing between the vineyards Dure Epine and Gouttes d'Or. Attacked by the Royalists, they drew up in good order in the latter spot, and prepared to defend themselves with all the stubborn valour of their race, their dense array of pikes bristling amongst the bright green leaves--for it was the close of summer, and the vines were in all the glory of their luxuriant foliage. Vainly for a long time the Royalists assailed them. Attack after attack was repulsed, till the 'golden drops' were turned to drops of gore; and it was not until the white plume of King Henri came dashing on in the forefront of his choicest cavalry that the Walloons were finally broken and routed, after inflicting upon their assailants a far greater loss than they themselves sustained. The vineyard thus baptised in blood was thenceforward known as the Vigne des Sièges.[438] [Illustration] [Illustration] Though data may be lacking to connect the 'bon Roi Henri' directly with the wine of Epernay, there can be no doubt that the sovereign whose triple talent for drinking, fighting, and love-making has been handed down to us in song[439] found a fair opportunity of exercising all three of these attributes during the siege. Of fighting, as we have seen, he had plenty, and, Anacreon-like, he seems to have blended love and wine together.[440] He who, when a new-born babe, had his lips wetted in the old castle of Pau by stout Antoine de Bourbon with a cup of the generous wine of the South, and who gloried in the title of the Sieur d'Ay, was not likely to neglect the nectar vintaged on the slopes around Epernay. And probably the recollection of the raven-haired, black-eyed, bronze-skinned Bernais peasant-girls, whom tradition vows he used to woo when in the first flush of youthful manhood beneath the trellised vines of Jurançon and Gan, served by contrast to heighten the fairer charms of the blonde Anne du Puy, in whose honour he is reported to have sung: 'Morning bright, Thy pure light I rejoice when I see; The fair dove Whom I love So, is rosy like thee. She is fair, None so rare, With a waist matched by none; By my hand It is spanned, And eyes bright as the sun. Wet with new Fallen dew, The rose sparkles less bright; Freer from spot Ermine's not, Nor is lily more white. Fair Dupuis, All agree, On ambrosia is fed; From her lip When I sip Nectar's perfume is shed.'[441] At the outset of the seventeenth century Epernay had its full share in the troubles that marked the early part of the reign of Louis XIII., being taken in turn by Condé, by the Count de Soissons, acting for the malcontent nobles leagued against Richelieu in 1634, and by the King's forces the year following. The peaceful records are, however, plentiful and interesting. In 1631 we find the town council deciding to present 'six caques of white wine, the best that can be found,' to M. de Vignolles, and the same to M. d'Elbenne; and two years later protesting to the 'treasurers of France' their inability to pay 70,000 livres, demanded towards the maintenance of the army, owing to the all but total failure of the wine crop. The council were fully aware of the merits of their vintage, and of the advantages of appealing to the heart by way of the stomach. Six 'feuillettes' of the best wine were ordered to be sent in September 1636 to M. de Vaubecourt, and one to his secretary, 'to retain their good-will towards the town,' and induce the former to use his influence with a committee appointed by the King for repaying loans and advances, and also towards getting rid of the garrison. A little later the Marquis de Senneterre received a queue of wine to withdraw his troops from the town. The Maréchal de Chatillon, M. de Vaubecourt, M. de Belfonds, and the Count d'Estaing were in frequent receipt of such gifts; and it is noteworthy that amongst them figure 'two caques of wine in bottles,' sent to each of the two first at Sainte Ménéhoulde in 1639.[442] [Illustration] The successful efforts of Turenne against his great rival Condé during the wars of the Fronde were encouraged by frequent presents of the wine of Epernay. As the brother of the Duc de Bouillon, to whom the town of Epernay had been given in 1643 in exchange for Sedan, and as the protector of the district against the Spaniards, he received numerous tokens of the citizens' good-will. In September 1652 twelve caques of wine were sent to him, with the result that he at once ordered his soldiers to repair the broken bridge across the Marne. In the following January a chevreuil and two caques, and in June wine, fowls, and game, were presented to him. In June 1654 it was resolved that a deputation should be sent to the coronation of Louis XIV. at Reims, 'to render the homage due to the King,' and to present 'a caque of wine in bottles' to M. de Turenne, which helped no doubt to spread the fame of the Epernay wine amongst the nobility present on that occasion. The same social lever was applied in 1660 to the 'traitant général' of the so-called 'don gratuit' exacted on the occasion of the King's marriage, two feuillettes being proffered in order to get him to reduce the assessment. Representations made to an eschevin of Paris, despatched to Epernay in 1662 to see if there was any store of grain in the town that could be sold to benefit the starving poor of the capital, to the effect that the district was a wine-growing and not a corn country; and the despatch of a deputation in August 1666 to Louvois, to request that the garrison might be withdrawn to allow of the vintage being gathered in--the inhabitants of the surrounding country having fled to avoid sheltering soldiers,--serve to show the importance of the Epernay wine-trade. In 1671, on the passage of the Duke and Duchess of Orleans from Châlons, fruit and sweetmeats were presented to them, and wine to the lords of their suite, at a cost of 211 livres 7 sols; and two years later, Louis XIV. partook of the local vintage during his sojourn at the 'maison abbatiale,' when on his way to the army of the Rhine. Towards the close of this century the wine grew in repute, and was eagerly sought after. In November 1677 two caques were sent to 'a person who enjoys some credit,' and who was willing to accord his protection to the town in the matter of quartering troops upon it; and the following January twelve more caques were despatched to this 'unknown,' who may have been Louvois himself. As to Roger Brulart, Marquis de Puisieux et de Sillery and Governor of Epernay, a joyous companion, if we may credit St. Simon, his appreciation of the local vintage is borne ample testimony to. In 1677 six caques of 'the best' were sent to him by the town council; but by 1691 he must have become used to larger offerings, as in September a letter was addressed to him begging him to be satisfied with the like amount, as 'the inhabitants could not manage more,' and could only promise, with regard to three caques still due, that they would 'make an effort' to supply them the following year. Wise in their generation, they sent at the same time 'twelve bottles of the best wine' to his intendant, and a similar gift to his secretary; but the following year they were forced to write again that it would be impossible to supply the wine promised unless he obtained a permission to levy it.[443] The Old Pretender, or, as he is styled in the local records, 'Jacques Stuart III., roy d'Angleterre,' arrived at Epernay in September 1712, and was presented with 'twenty-four bottles of the best;' whilst the Marquis de Puisieux, who accompanied him, was satisfied with nothing less than a 'carteau,' or quarter-cask. And when the latter announced his intention of paying a visit in the autumn of 1719 to Maître Adam Bertin du Rocheret, conseiller du roy and ex-president of the Grenier-à-sel at Epernay, a resolution was passed to offer him wine on his arrival, and to send 'a hundred _flasks_ of the best' to his château of Sillery. The use of the word 'flaçons' clearly implies that the discoveries of Dom Perignon were being acted upon at Epernay, and that the gift in question was one of sparkling wine. [Illustration: JAMES EDWARD FRANCIS STUART, THE OLD PRETENDER.] In June 1722 the Sieurs Quatresous and Chertemps, despatched to congratulate the marquis's nephew and successor, Louis Philogène Brulart, on his appointment to the governorship of the town and his marriage with Mademoiselle de Souvré, granddaughter of Louvois, took with them a similar offering. At the coronation of Louis XV., in October, deputies were sent to compliment the Prince de Turenne, representative of his father the Duc de Bouillon, seigneur d'Epernay, and to present him with 'game, trout, and other fish,' and 'a basket of a hundred flasks of the best.' In August 1725 the bourgeois were drawn up under arms, and four dozen bottles were got ready, on the passage through the town of the Duke of Orleans, son of the late Regent, on his way to espouse, as the King's proxy, Marie Leczinska. This was, however, a sad year for the wine-growers, for ten months of incessant rain, beginning in April, not only ruined the at first promising crop entirely, but caused floods which wrought some havoc. The terrible hail-storm of 1730, which devastated the vineyards of Reims, fortunately spared those of Epernay; but a frost in October 1740 destroyed the vintage, and led to a dearness of provisions which pressed even on the most well-to-do.[444] For the next three-quarters of a century Epernay continued quietly to profit by the yield of 'the slopes laden with vines producing the most delicious wines in Europe,' to quote the expression of Stapart, who in 1749 notes the importance of the trade in wine carried on, not only with Paris, but with foreign countries; though at the same time complaining of the decreasing size of the town, and the fact of vineyards being planted where houses had formerly stood.[445] The only events of importance were from time to time an unusually good or an uncommonly bad crop, or--as the manufacture of _vin mousseux_ gradually swallowed up that of still wine--a disastrous _casse_, like the memorable one of 1776, varied by an occasional royal visit or so. By 1780, Max Sutaine notes that a single manufacturer would turn out from five to six thousand bottles of sparkling Champagne, and exults over the fact that seven years later an enterprising firm risked a _tirage_ of fifty thousand, though people at the time regarded this as something prodigious, and wondered where an outlet would be found.[446] Very likely a bottle of this identical _tirage_ was 'the excellent _vin mousseux_' with which Arthur Young regaled himself, at a cost of forty sous, on the 7th July of the same year, at that 'very good inn' the Hôtel de Rohan, at Epernay.[447] At this same inn the hapless Louis XVI. stopped to dine on his return from the intercepted flight to Varennes; and when we recall his timid nature, we may fairly surmise that it was Champagne which inspired him, amidst the insults of the mob, to remind the authorities that his ancestor, Henri Quatre, had entered the town in a very different fashion, and by implication to assert that he might yet do the same.[448] The Emperor Napoleon, the Empress Josephine, the King of Westphalia, and the other members of the Bonaparte dynasty, who from time to time visited Epernay and partook of the hospitality of Jean Remi Moët, showed a healthy appreciation of its vintage. Indeed King Jerome, in giving an order for six thousand bottles _premier cru_, remarked with a strange foresight that he would have taken more, only he was afraid that it would be the Russians after all who would come and drink it. Sure enough the eventful year 1814 witnessed the arrival at Epernay of a host of self-invited guests, all equally appreciative of the merits of Champagne, and gifted with an almost unlimited power of consumption, but entertaining insuperable objections to pay for what they consumed. The Prussians and Russians who came hither in February and March misconducted themselves in a very sad manner, burning and pillaging houses, insulting and maltreating the inhabitants, requisitioning all the wine they could lay hands on, and drinking in a manner recalling the Bacchic exploits of Gargantua and Pantagruel. The mayor, Jean Remi Moët, moved by the state of affairs, offered the invaders the free run of his cellars rather than that they should pillage those of others, doubtless under the idea that the reputation his house would thus acquire abroad would soon enable him to retrieve the temporary loss--a proviso happily and amply realised. Beyond the facts that Epernay has profited, and continues to profit, by the ever-increasing development of the taste for sparkling wine; that Charles X., Louis Philippe, and Napoleon III. have successively favoured it with their presence, and accepted the _vin d'honneur_ offered on such occasions; and that during the war of 1870-1 the town, in common with the rest of the province of Champagne, was occupied by the German invading army, there is nothing more to be said respecting its history. [Illustration: THE RUE DU COMMERCE (FAUBOURG DE LA FOLIE), EPERNAY.] [Illustration: THE PACKING-HALL AT MESSRS. MOËT AND CHANDON'S, EPERNAY.] X. /The Champagne Establishments of Epernay and Pierry./ Early records of the Moët family at Reims and Epernay--Jean Remi Moët, the founder of the commerce in Champagne wines--Extracts from old account-books of the Moëts--Jean Remi Moët receives the Emperor Napoleon, the Empress Josephine, and the King of Westphalia--The firm of Moët & Chandon constituted--Their establishment in the Rue du Commerce--The delivery and washing of new bottles--The numerous vineyards and vendangeoirs of the firm--Their cuvée made in vats of 12,000 gallons--The bottling of the wine--A subterranean city, with miles of streets, cross-roads, open spaces, tramways, and stations--The ancient entrance to these vaults--Tablet commemorative of the visit of Napoleon I.--The original vaults known as Siberia--Scene in the packing-hall--Messrs. Moët & Chandon's large and complete staff--The famous 'Star' brand of the firm--Perrier-Jouët's château, offices, and cellars--Classification of the wine of the house--The establishment of Messrs. Pol Roger & Co.--Their large stock of the fine 1874 vintage--The preparations for the tirage--Their vast fireproof cellier and its temperature--Their lofty and capacious cellars--Pierry becomes a wine-growing district consequent upon Dom Perignon's discovery--Esteem in which the growths of the Clos St. Pierre were held--Cazotte, author of _Le Diable Amoureux_, and guillotined for planning the escape of Louis XVI. from France, a resident at Pierry--His contest with the Abbot of Hautvillers with reference to the abbey tithes of wine--The Château of Pierry--Its owner demands to have it searched to prove that he is not a forestaller of corn--The vineyards and Champagne establishment of Gé-Dufaut & Co.--The reserves of old wines in the cellars of this firm--Honours secured by them at Vienna and Paris. [Illustration] Those magnates of the Champagne trade, Messrs. Moët & Chandon, whose famous 'Star' brand is familiar in every part of the civilised globe, and whose half-score miles of cellars contain as many million bottles of Champagne as there are millions of inhabitants in most of the secondary European States, have their head-quarters at Epernay in a spacious château--in that street of châteaux named the Rue du Commerce, but commonly known as the Faubourg de la Folie--which is approached through handsome iron gates, and has beautiful gardens in the rear extending in the direction of the River Marne. The existing firm dates from the year 1833, but the family of Moët--conjectured to have originally come from the Low Countries--had already been associated with the Champagne wine trade for well-nigh a century previously. If the Moëts came from Holland they must have established themselves in the Champagne at a very early date, for the annals of Reims record that in the fourteenth century Jehan Moët de Mennemont, _escuier_, held a fief at Attigny from the Archbishop Richard Pique, and that in the following century Jean and Nicolas Moët were _échevins_ of the city. A Moët was present in that capacity at the coronation of Charles VII. in 1429, when Joan of Arc stood erect by the principal altar of the cathedral with her sacred banner in her hand; and for having contributed to repulse an attempt on the part of the English to prevent the entrance of the Royal party into the city, the Moëts were subsequently ennobled by the same monarch. A mural tablet in the church of St. Remi records the death of D. G. Moët, Grand Prior, in 1554; and nine years later we find Nicol Moët claiming exemption at Epernay for the payment of _tailles_ on the ground of his being a noble. An old commercial book preserved in the family archives shows that in the year 1743--at the epoch when the rashness of the Duc de Grammont saved the English army under George II. from being cut to pieces at Dettingen--a descendant of the foregoing, one Claude Louis Nicolas Moët, who owned considerable vineyard property in the vicinity of Epernay, decided upon embarking in the wine trade. It is his son, however, Jean Remi Moët, born in 1758, who may be looked upon as the veritable founder of the present commerce in Champagne wines, which, thanks to his efforts, received a wonderful impulse, so that instead of the consumption of the vintages of the Marne being limited as heretofore to the privileged few, it spread all over the civilised world. [Illustration: JEAN REMI MOËT.] At Messrs. Moët & Chandon's we had the opportunity of inspecting some of the old account-books of the firm, and more particularly those recording the transactions of Jean Remi Moët and his father. The first sales of sparkling wine, on May 23d, 1743, comprised 301 bottles of the vintage of 1741 to Pierre Joly, wine-merchant, _bon des douze chez le Roi_, whatever that may mean, at Paris; 120 bottles to Pierre Gabriel Baudoin, also _bon des douze_, at Paris; and a similar quantity to the Sieur Compoin, keeping the 'hotellerie ditte la pestitte Escurie,' Rue du Port-Maillart, at Nantes in Brittany. The entry specifies that the wine for Nantes is to be left at Choisy-le-Roi, and taken by land to Orleans by the carters of that town, who are to be found at the Ecu d'Orléans, Porte St. Michel, Paris, the carriage as far as Choisy being 4 livres 10 deniers (about 4 francs) for the two half-baskets, and to Paris 3 livres 15 deniers the basket. Between 1750 and '60 parcels of wine were despatched to Warsaw, Vienna, Berlin, Königsberg, Dantzig, Stettin, Brussels, and Amsterdam; but one found no mention of any sales to England till the year 1788, when the customers of the firm included 'Milord' Farnham, of London, and Messrs. Felix Calvert & Sylvin, who had a couple of sample-bottles sent to them, for which they were charged five shillings. In the same year Messrs. Carbonnell, Moody, & Walker (predecessors of the well-known existing firm of Carbonnell & Co.) wrote in French for two baskets, of ten dozens each, of _vin de Champagne_ 'of good body, not too charged with liqueur, but of excellent taste, and not at all sparkling.' The Chevalier Colebrook, writing from Bath, also requests that 72 bottles of Champagne may be sent to his friend the Hon. John Butler, Molesworth-street, Dublin, 'who, if contented with the wine, will become a good customer, he being rich, keeping a good house, and receiving many amateurs of _vin de Champagne_.' Shortly afterwards the Chevalier himself receives 50 bottles of still wine, vintage 1783. In 1789 120 bottles of Champagne, vintage 1788, are supplied to 'Milord' Findlater, of London; and in 1790 the customers of the house include Power & Michel, of 44 Lamb-street, London, and Manning, of the St. Alban Tavern, the latter of whom is supplied on March 30th with 130 bottles of Champagne at three livres, or two 'schillings,' per bottle; while a month later Mr. Lockart, banker, of 36 Pall Mall, is debited with 360 bottles, vintage 1788, at three shillings. In this same year M. Moët despatches a traveller to England named Jeanson, and his letters, some two hundred in number, are all preserved in the archives of the house. On the 17th May 1790 he writes from London as follows: 'As yet I have only gone on preparatory and often useless errands. I have distributed samples of which I have no news. Patience is necessary, and I endeavour to provide myself with it. How the taste of this country has changed since ten years ago! Almost everywhere they ask for dry wine, but at the same time require it so vinous and so strong that there is scarcely any other than the wine of Sillery which can satisfy them.... To-morrow I dine five miles from here, at M. Macnamara's. We shall uncork four bottles of our wine, which will probably be all right.' In May 1792 Jean Remi Moët is married, and thenceforward assumes the full management of the house. On December 20 of the year following, when the Reign of Terror was fairly inaugurated, we find the accounts in the ledger opened to this or the other 'citoyen.' The orthodox Republican formula, however, did not long continue, and 'sieur' and 'monsieur' resumed their accustomed places, showing that Jean Remi Moët had no sympathy with the Jacobin faction of the day. In 1805 he became Mayor of Epernay, and between this time and the fall of the Empire received Napoleon several times at his residence, as well as the Empress Josephine and the King of Westphalia. The Emperor, after recapturing Reims from the Allies, came on to Epernay, on which occasion he presented M. Moët with the Cross of the Legion of Honour. In 1830 the latter was arbitrarily dismissed from his mayoralty by Charles X., but was speedily reinstated by Louis Philippe, though he did not retain his office for long, his advanced age compelling him to retire from active life in the course of 1833. At this epoch the firm, which since 1807 had been known as Moët & Co., was remodelled under the style of Moët & Chandon, the two partners being M. Victor Moët, son of the outgoing partner, and M. P. G. Chandon, the descendant of an old ennobled family of the Mâconnais, who had married M. Jean Remi Moët's eldest daughter. The descendants of these gentlemen are to-day (1880) at the head of the business, the partners being, on the one hand, M. Victor Moët-Romont and M. C. J. V. Auban Moët-Romont; and on the other, MM. Paul and Raoul Chandon de Briailles. Facing Messrs. Moët & Chandon's offices at Epernay is a range of comparatively new buildings, with its white façade ornamented with the well-known monogram M. & C., surmounted by the familiar star. It is here that the business of blending and bottling the wine is carried on. Passing through the arched gateway, access is obtained to a spacious courtyard, where carts laden with bottles are being expeditiously lightened of their fragile contents by the busy hands of numerous workmen. Another gateway on the left leads into the spacious bottle-washing room, which from the middle of May until the middle of July presents a scene of extraordinary animation. Bottle-washing apparatus, supplied by a steam-engine with 20,000 gallons of water per diem, are ranged in fifteen rows down the entire length of this hall, and nearly 200 women strive to excel each other in diligence and celerity in their management, a practised hand washing from 900 to 1000 bottles in the course of the day. To the right of this _salle de rinçage_, as it is styled, bottles are stacked in their tens of thousands, and lads furnished with barrows, known as _diables_, hurry to and fro, conveying these to the washers, or removing the clean bottles to the adjacent courtyard, where they are allowed to drain prior to being taken to the _salle de tirage_ or bottling-room. Before, however, the washing of bottles on this gigantic scale commences, the 'marrying' or blending of the wine is accomplished in a vast apartment, 250 feet in length and 100 feet broad, during the early spring. The casks of newly-vintaged wine, which have been stowed away during the winter months in the extensive range of cellars hewn out of the chalk underlying Epernay, where they have slowly fermented, are mixed together in due proportion in huge vats, each holding upwards of 12,000 gallons. Some of this wine is the growth of Messrs. Moët & Chandon's own vineyards, of which they possess as many as 900 acres (giving constant employment to 800 labourers and vinedressers) at Ay, Avenay, Bouzy, Cramant, Champillon, Chouilly, Dizy, Epernay, Grauves, Hautvillers, Le Mesnil, Moussy, Pierry, Saran, St. Martin, Verzy, and Verzenay, and the average annual cost of cultivating which is about £40 per acre. At Ay the firm own 210 acres of vineyards; at Cramant and Chouilly, nearly 180 acres; at Verzy and Verzenay, 120 acres; at Pierry and Grauves, upwards of 100 acres; at Hautvillers, 90 acres; at Le Mesnil, 80 acres; at Epernay, nearly 60 acres; and at Bouzy, 55 acres. Messrs. Moët & Chandon, moreover, possess vendangeoirs, or pressing-houses, at Ay, Bouzy, Cramant, Epernay, Hautvillers, Le Mesnil, Pierry, Saran, and Verzenay, in which the large number of 40 presses are installed. At these vendangeoirs no less than 5450 pièces of fine white wine, sufficient for 1,360,000 bottles of Champagne, are annually made--that is, 1200 pièces at Ay, 1100 at Cramant and Saran, 800 at Verzy and Verzenay, and smaller quantities at the remaining establishments. All these establishments have their celliers and their cellars, together with cottages for the accommodation of the numerous vinedressers in the employment of the firm. [Illustration: WASHING BOTTLES AT MESSRS. MOËT AND CHANDON'S, EPERNAY.] Extensive as are the vineyards owned by Messrs. Moët & Chandon, the yield from them is utterly inadequate to the enormous demand which the great Epernay firm are annually called upon to supply, and large purchases have to be made by their agents from the growers throughout the Champagne. The wine thus secured, as well as that grown by the firm, is duly mixed together in such proportions as will insure lightness with the requisite vinosity, and fragrance combined with effervescence, a thorough amalgamation being effected by stirring up the wine with long poles provided with fan-shaped ends. If the vintage be indifferent in quality, the firm have scores of huge tuns filled with the yield of more favoured seasons to fall back upon to insure any deficiencies of character and flavour being supplied. [Illustration: MESSRS. MOËT AND CHANDON'S VENDANGEOIR AT BOUZY.] The casks of wine to be blended are raised from the cellars, half a dozen at a time, by means of a lift provided with an endless chain, and worked by the steam-engine of which we have already spoken. They are emptied, through traps in the floor of the room above, into the huge vats which, standing upon a raised platform, reach almost to the ceiling. From these vats the fluid is allowed to flow through hose into rows of casks stationed below. Before being bottled the wine reposes for a certain time; is next duly racked and again blended; and is eventually conveyed through silver-plated pipes into oblong reservoirs, each fitted with a dozen syphon-taps, so arranged that directly the bottle slipped on to one of them becomes full the wine ceases to flow. Upwards of 200 workpeople are employed in the _salle de tirage_ at Messrs. Moët & Chandon's, which, while the operation of bottling is going on, presents a scene of bewildering activity. Men and lads are gathered round the syphon-taps, briskly removing the bottles as they become filled, and supplanting them by empty ones. Other lads hasten to transport the filled bottles on trucks to the corkers, whose so-called 'guillotine' machines send the corks home with a sudden thud. The corks being secured with _agrafes_, the bottles are placed in large flat baskets called _manettes_, and wheeled away on trucks, the quarts being deposited in the cellars by means of lifts, while the pints slide down an inclined plane by the aid of an endless chain, which raises the trucks with the empty baskets at the same time the full ones make their descent into the cellars. What with the incessant thud of the corking-machines, the continual rolling of iron-wheeled trucks over the concrete floor, the rattling and creaking of the machinery working the lifts, the occasional sharp report of a bursting bottle, and the loudly-shouted orders of the foremen, who display the national partiality for making a noise to perfection, the din becomes at times all but unbearable. The number of bottles filled in the course of the day naturally varies, still Messrs. Moët & Chandon reckon that during the month of June a daily average of 100,000 are taken in the morning from the stacks in the _salle de rinçage_, washed, dried, filled, corked, wired, lowered into the cellars, and carefully arranged in symmetrical order. This represents a total of two and a half million bottles during that month alone. The bottles on being lowered into the cellars, either by means of the incline or the lifts, are placed in a horizontal position, and, with their uppermost side daubed with white chalk, are stacked in layers from two to half a dozen bottles deep, with narrow oak laths between. The stacks are usually about 6 or 7 feet high, and 100 feet and upwards in length. Whilst the wine is thus reposing in a temperature of about 55° Fahrenheit, fermentation sets in, and the ensuing month is one of much anxiety. Thanks, however, to the care bestowed, Messrs. Moët & Chandon's annual loss from bottles bursting rarely exceeds three per cent, though fifteen was once regarded as a respectable and satisfactory average. The broken glass is a perquisite of the workmen, the money arising from its sale, which at the last distribution amounted to no less than 20,000 francs, being divided amongst them every couple of years. [Illustration: BOTTLING CHAMPAGNE AT MESSRS. MOËT AND CHANDON'S, EPERNAY.] The usual entrance to Messrs. Moët & Chandon's Epernay cellars--which, burrowed out in all directions, are of the aggregate length of nearly seven miles, and have usually between 10,000,000 and 12,000,000 bottles and 20,000 casks of wine stored therein--is through a wide and imposing portal, and down a long and broad flight of steps. It is, however, by the ancient and less imposing entrance, through which more than one crowned head has condescended to pass, that we set forth on our lengthened tour through these intricate underground galleries--this subterranean city, with its miles of streets, cross-roads, open spaces, tramways, and stations devoted solely to Champagne. A gilt inscription on a black-marble tablet testifies that 'on the 26th July 1807, Napoleon the Great, Emperor of the French, King of Italy, and Protector of the Confederation of the Rhine, honoured commerce by visiting the cellars of Jean Remi Moët, Mayor of Epernay, President of the Canton, and Member of the General Council of the Department,' within three weeks of the signature of the treaty of Tilsit. Passing down the flight of steep slippery steps traversed by the victor of Eylau and Jena, access is gained to the upper range of vaults, brilliantly illuminated by the glare of gas, or dimly lighted by the flickering flame of tallow-candles, upwards of 60,000 lb. of which are annually consumed. Here group after group of the small army of 350 workmen employed in these subterranean galleries are encountered, engaged in the process of transforming the _vin brut_ into Champagne. At Messrs. Moët & Chandon's, the all-important operation of liqueuring the wine is effected by aid of machines of the latest construction, which regulate the quantity administered to the utmost nicety. The corks are branded by being pressed against steel dies heated by gas by women, who can turn out 3000 per day apiece, the quantity of string used to secure them amounting to nearly ten tons in the course of the year. [Illustration: TABLET COMMEMORATIVE OF THE VISIT OF NAPOLEON I.] There is another and a lower depth of cellars to be explored, to which access is gained by trap-holes in the floor--through which the barrels and baskets of wine are raised and lowered--and by flights of steps. From the foot of the latter there extends an endless vista of lofty and spacious passages hewn out of the chalk, the walls of which, smooth as finished masonry, are lined with thousands of casks of raw wine, varied at intervals by gigantic vats. Miles of long, dark-brown, dampish-looking galleries stretch away to the right and left, devoid of the picturesque festoons of fungi which decorate the London Dock vaults, yet exhibiting a sufficient degree of mouldiness to give them an air of respectable antiquity. These multitudinous galleries, lit up by petroleum-lamps, are mostly lined with wine in bottles stacked in compact masses to a height of six or seven feet, only room enough for a single person to pass being left. Millions of bottles are thus arranged, the majority on their side, in huge piles, with tablets hung up against each stack to note its age and quality; and the rest, which are undergoing daily evolutions at the hands of the twister, in racks at various angles of inclination. These cellars contain nearly 11,000 racks, and as many as 600,000 bottles are commonly twisted here daily. [Illustration] The way runs on between regiments of bottles of the same size and shape, save where at intervals pints take the place of quarts; and the visitor, gazing into the black depths of the transverse passages to the right and left, becomes conscious of a feeling that if his guide were suddenly to desert him, he would feel as hopelessly lost as in the catacombs of Rome. There are two galleries, each 650 feet in length, containing about 650,000 bottles, and connected by 32 transverse galleries, with an aggregate length of 4000 feet, in which nearly 1,500,000 bottles are stored. There are, further, eight galleries, each 500 feet in length, and proportionably stocked; also the extensive new vaults, excavated some five or six years back, in the rear of the then existing cellarage, and a considerable number of smaller vaults. The different depths and varying degrees of moisture afford a choice of temperature of which the experienced owners know how to take advantage. The original vaults, wherein more than a century ago the first bottles of Champagne made by the infant firm were stowed away, bear the name of Siberia, on account of their exceeding coldness. This section consists of several roughly-excavated low winding galleries, resembling natural caverns, and affording a striking contrast to the broad, lofty, and regular-shaped corridors of more recent date. When the proper period arrives for the bottles to emerge once more into the upper air, they are conveyed to the packing-room, a spacious hall 180 feet long and 60 feet broad. In front of its three large double doors wagons are drawn up ready to receive their loads. The 70 men and women employed here easily foil, label, wrap, and pack up some 10,000 bottles a day. Cases and baskets are stacked in different parts of this vast hall, at one end of which numerous trusses of straw used in the packing are piled. Seated at tables ranged along one side of the apartment women are busily occupied in pasting on labels or encasing the necks of bottles in gold or silver foil, whilst elsewhere men, seated on three-legged stools in front of smoking caldrons of molten sealing-wax of a deep green hue, are coating the necks of other bottles by plunging them into the boiling fluid. When labelled and decorated with either wax or foil, the bottles pass on to other women, who swathe them in pink tissue-paper and set them aside for the packers, by whom, after being deftly wrapped round with straw, they are consigned to baskets or cases, to secure which last no less than 10,000 lb. of nails are annually used. England and Russia are partial to gold foil, pink paper, and wooden cases holding a dozen or a couple of dozen bottles of the exhilarating fluid, whereas other nations prefer waxed necks, disdain pink paper, and insist on being supplied in wicker baskets containing fifty bottles each. Some idea of the complex character of so vast an establishment as that of Messrs. Moët & Chandon may be gathered from a mere enumeration of their staff, which, in addition to twenty clerks and 350 cellarmen proper, includes numerous agrafe-makers and corkcutters, packers and carters, wheelwrights and saddlers, carpenters, masons, slaters and tilers, tinmen, firemen, needlewomen, &c., while the inventory of objects used by this formidable array of workpeople comprises no fewer than 1500 distinct heads. A medical man attached to the establishment gives gratuitous advice to all those employed, and a chemist dispenses drugs and medicines without charge. While suffering from illness the men receive half-pay, but should they be laid up by an accident met with in the course of their work full salary is invariably awarded to them. As may be supposed, so vast an establishment as this is not without a provision for those past work, and all the old hands receive liberal pensions from the firm upon retiring. It is needless to particularise Messrs. Moët & Chandon's wines, which are familiar to all drinkers of Champagne. Still it may be mentioned that the great Epernay firm, with the view of meeting the requirements of the time, have lately commenced shipping a high-class _vin brut_, or natural Champagne, possessing great vinosity, combined with remarkable delicacy of flavour. To this fine dry wine the name of 'Brut Impérial' has been given by the house. Moët & Chandon's famous 'Star' brand is known in all societies, figures equally at clubs and mess-tables, at garden-parties and picnics, dinners and _soirées_, and has its place in hotel _cartes_ all over the world. One of the best proofs of the wine's universal popularity is found in the circumstance that as many as a thousand visitors from all parts of the world come annually to Epernay and make the tour of Messrs. Moët & Chandon's spacious cellars. A little beyond Messrs. Moët & Chandon's, in the broad Rue du Commerce, we encounter a heavy, ornate, pretentious-looking château, the residence of the late M. Perrier-Jouët, presenting a striking contrast to the almost mean-looking premises opposite, where the business of the firm is carried on. On the left-hand side of a courtyard surrounded by low buildings, which serve as celliers, store-houses, packing-rooms, and the like, are the offices; and from an inner courtyard, where piles of bottles are stacked under open sheds, the cellars themselves are reached. Previous to descending into these we passed through the various buildings, in one of which a party of men were engaged in disgorging and preparing wine for shipment. In another we noticed one of those heavy beam presses for pressing the grapes which the more intelligent manufacturers regard as obsolete, while in a third was the cuvée vat, holding no more than 2200 gallons. In making their cuvée the firm commonly mix one part of old wine to three parts of new. An indifferent vintage, however, necessitates the admixture of a larger proportion of the older growth. The cellars, like all the more ancient ones at Epernay, are somewhat straggling and irregular; still they are remarkably cool, and on the lower floor remarkably damp as well. This, however, would appear to be no disadvantage, as the breakage in them is calculated never to exceed 2-1/2 per cent. The firm have no less than five qualities of wine, and at one of the recent Champagne competitions at London, where the experts engaged had no means of identifying the brands submitted to their judgment, Messrs. Perrier-Jouët's First Quality got classed below a cheaper wine of their neighbours, Messrs. Pol Roger & Co., and very considerably below the Extra Sec of Messrs. Périnet et fils, and inferior even to a wine of De Venoge's, the great Epernay manufacturer of common-class Champagne. Champagne establishments, combined with the handsome residences of the manufacturers, line both sides of the long imposing Rue du Commerce at Epernay. On the left hand is a succession of fine châteaux, commencing with one belonging to M. Auban Moët, whose terraced gardens overlook the valley of the Marne, and command views of the vine-clad heights of Cumières, Hautvillers, Ay, and Mareuil, and the more distant slopes of Ambonnay and Bouzy; while on the other side of the famous Epernay thoroughfare we encounter beyond the establishments of Messrs. Moët & Chandon and Perrier-Jouët the ornate monumental façade which the firm of Piper & Co.--of whom Messrs. Kunkelmann & Co. are to-day the successors--raised some years since above their extensive cellars. In a side street at the farther end of the Rue du Commerce stands a château of red brick, overlooking on the one side an extensive pleasure-garden, and on the other a spacious courtyard, bounded by celliers, stables, and bottle-sheds, all of modern construction and on a most extensive scale. These form the establishment of Messrs. Pol Roger & Co., settled for many years at Epernay, and known throughout the Champagne for their large purchases at the epoch of the vintage. From the knowledge they possess of the best crus, and their relations with the leading vineyard proprietors, they are enabled whenever the wine is good to acquire large stocks of it. Having bottled a considerable quantity of the fine wine of 1874, they resolved to profit by the exceptional quality of this vintage to commence shipping Champagne to England, where their agents, Messrs. Reuss, Lauteren, & Co., have successfully introduced the new brand. Passing through a large open gateway, we enter the vast courtyard of the establishment, which, with arriving and departing carts--the first loaded with wine in cask or with new bottles, and the others with cases of Champagne--presents rather an animated scene. Under a roof projecting from the wall of the vast cellier on the right hand a tribe of 'Sparnaciennes'--as the feminine inhabitants of Epernay are termed--are occupied in washing bottles in readiness for the coming tirage. The surrounding buildings, most substantially constructed, are not destitute of architectural pretensions. The extensive cellier, the area of which is 23,589 square feet, is understood to be the largest single construction of the kind in the Champagne district. Built entirely of iron, stone, and brick, its framework is a perfect marvel of lightness. The roof, consisting of rows of brick arches, is covered above with a layer of Portland cement, in order to keep it cool in summer and protect it against the winter cold, two most desirable objects in connection with the manipulation of Champagne. Here an endless chain of a new pattern enables wine in bottle to be lowered and raised with great rapidity to or from the cellars beneath--lofty and capacious excavations of two stories, the lower one of which is reached by a flight of no less than 170 steps. [Illustration: COURTYARD OF MESSRS. POL ROGER AND CO.'S ESTABLISHMENT AT EPERNAY.] Less than a couple of miles southward of Epernay, on the high-road to Troyes, is the village of Pierry, which, unlike most of the Champagne villages, is one of those happy spots with little or no history. Up to the close of the seventeenth century it was an insignificant hamlet; but at that epoch--when Dom Perignon's discovery gave such an impetus to the viticultural industry of the Marne--the waste land lying around it was broken up and planted with vines, and a number of rich strangers, chiefly from Epernay, built themselves houses and vendangeoirs here, and contributed to the erection of the church. The Benedictines of St.-Pierre-aux-Monts at Châlons, who continued to be the titular seigneurs of Pierry up to the period of the Revolution, were not behindhand in attention to their vines, and during the early part of the eighteenth century the wine vintaged in their Clos St. Pierre, under the fostering care of Brother Jean Oudart--whose renown almost equalled that of Perignon himself--was very highly esteemed.[449] During the eighteenth century Pierry continued to be a favourite residence of well-to-do landowners,[450] and was further embellished by the construction of numerous handsome châteaux, the most interesting, from a historic point of view, being that formerly belonging to Cazotte.[451] It was here that the ex-Commissary General of the navy composed the greater part of his works, and elaborated that futile scheme for the escape of Louis XVI. after Varennes, which was to conduct its author to the scaffold.[452] The visionary dreamer, to whom we owe the _Diable Amoureux_, appears at Pierry in the triple character of a practical viticulturist, a village Hampden withstanding with dauntless breast that little tyrant of the surrounding vineyards--the Abbot of Hautvillers,[453] and a local legislator put forward in the proprietarial interest at the outbreak of that Revolution[454] which he appears to have foreseen, if not to have directly prophesied, as he has been credited with doing.[455] Amongst the most imposing of the remaining Pierry châteaux is the one situate in that part of the village known as Corrigot, and now in the occupation of Messrs. Gé-Dufaut & Co. Its grandiose aspect, various courts, charming garden, fine trees, and clear lake justify this firm in adopting, in combination with an anchor, the title Château de Pierry as the brand of their wine. Prior to the Revolution the château belonged to M. de Papillon de Sannois, a fermier-général of that period. The municipal records of Pierry contain a petition addressed by him to the authorities in 1791, at a time when a panic prevailed respecting the forestallers of corn, begging them to institute a formal search throughout his residence, in order to give the lie to the rumours accusing him of having bought up and stored away a considerable quantity of wheat. The municipality accepted his invitation, and the result was a certificate to the effect that the total amount of wheat and oats stored there only represented three months' consumption for the household. Messrs. Gé-Dufaut & Co. are the owners of vineyards both in Pierry and the neighbouring parts, and for upwards of thirty years the firm have been engaged in preparing and shipping Champagnes. Their cellars, excavated in the mingled stone, chalk, and earth which form the prevailing soil of the district, extend beneath the vineyards belonging to the firm, and are walled and vaulted throughout. The circumstance of their being on one level, slightly below the celliers of the establishment, is a great convenience as regards the various manipulations which the wine has to undergo. Considerable reserves of old wines of the best years are stored in these vaults. The cultivation of the vineyards owned by the firm, and the pressing, maturing, and general cellar management of their wines are under the personal superintendence of the various partners, with a highly satisfactory result, as is proved by the first-class medal secured by the firm at the Vienna Exhibition of 1873, and the gold medal awarded to them at the Paris Exhibition of 1878. Messrs. Gé-Dufaut & Co. ship their wines to Europe, America, and India, and more especially to England, where their dry, natural, and unalcoholised Champagne has acquired a deserved reputation. The firm, moreover, are the officially appointed furnishers of Champagne to the Courts of Italy and Spain. [Illustration: CHÂTEAU OF PIERRY, THE PROPERTY OF MESSRS. GÉ-DUFAUT AND CO.] [Illustration] [Illustration: VIEW OF AY FROM THE BANKS OF THE MARNE CANAL.] XI. /Some Champagne Establishments at Ay and Mareuil./ The _bourgade_ of Ay and its eighteenth-century château--Gambling propensities of a former owner, Balthazar Constance Dangé-Dorçay--Appreciation of the Ay vintage by Sigismund of Bohemia, Leo X., Charles V., Francis I., and Henry VIII.--Bertin du Rocheret celebrates this partiality in triolets--Estimation of the Ay wine in the reigns of Charles IX. and Henri III.--Is a favoured drink with the leaders of the League, and with Henri IV., Catherine de Medicis, and the courtiers of that epoch--The 'Vendangeoir d'Henri Quatre' at Ay--The King's pride in his title of Seigneur d'Ay and Gonesse--Dominicus Baudius punningly suggests that the 'Vin d'Ay' should be called 'Vinum Dei'--The merits of the wine sung by poets and extolled by wits--The Ay wine in its palmy days evidently not sparkling--Arthur Young's visit to Ay in 1787--The establishment of Deutz & Geldermann--Drawing off the cuvée there--Mode of excavating cellars in the Champagne--The firm's new cellars, vineyards, and vendangeoir--M. Duminy's cellars and wines--The house founded in 1814--The new model Duminy establishment--Picturesque old house at Ay--Messrs. Pfungst Frères & Co.'s cellars--Their finely-matured dry Champagnes--The old church of Ay and its numerous decorations of grapes and vine-leaves--The sculptured figure above the Renaissance doorway--The Montebello establishment at Mareuil--The château formerly the property of the Dukes of Orleans--A titled Champagne firm--The brilliant career of Marshal Lannes--A promenade through the Montebello establishment--The press-house, the cuvée-vat, the packing-room, the offices, and the cellars--Portraits and relics at the château--The establishment of Bruch-Foucher & Co.--The handsome carved gigantic cuvée-tun--The cellars and their lofty shafts--The wines of the firm. [Illustration: FIGURE ABOVE THE DOORWAY OF AY CHURCH.] The historic _bourgade_ of Ay is within a short walk of the station on the line of railway connecting Epernay with Reims. The road lies across the light bridge spanning the Marne canal, the tall trees fringing which hide for a time the clustering houses; still we catch sight of the steeple of the antique church, relieved by a background of vine-covered slopes, and of an eighteenth-century château rising above a mass of foliage. Perched half-way up the slope, covered with 'golden plants,' which rises in the rear of the village, the château, with its long façade of windows, commands the valley of the Marne for miles; and from the stately-terraced walk, planted with ancient lime-trees, geometrically clipped in the fashion of the last century, a splendid view of the distant vineyards of Avize, Cramant, Epernay, and Chouilly is obtained. The château formed one of a quartette of seignorial residences which, at the commencement of the present century, belonged to Balthazar Constance Dangé-Dorçay, whose ancestors had been lords of Chouilly under the _ancien régime_. Dorçay had inherited from an aunt the châteaux of Ay, Mareuil, Boursault, and Chouilly, together with a large patrimony in land and money; but a mania for gambling brought him to utter ruin, and he dispossessed himself of money, lands, and châteaux in succession, and was reduced, in his old age, to earn a meagre pittance as a violin-player at the Paris Opera-house. The old château of Boursault, which still exists contiguous to the stately edifice raised by Madame Clicquot on the summit of the hill, was risked and lost on a single game at cards by this pertinacious gamester, whose pressing pecuniary difficulties compelled him to sell the remaining châteaux one by one. That of Ay was purchased by M. Froc de la Boulaye, and by him bequeathed to his cousin the Count de Mareuil, whose son is to-day a partner in the Champagne house of Ayala & Co. The wine of Ay, from an early date, has found equal favour in the eyes of poets and princes. Eustache Deschamps sang its praises in the fourteenth century, and was echoed a hundred years later by the anonymous author of the _Eglogue sur le Retour de Bacchus_.[456] Sigismund of Bohemia, the betrayer of John Huss, on visiting France in 1410, desired to pass through Ay in order to taste the wine at the place of its production.[457] Leo X., Charles V., Francis III., and our own Henry VIII., each had a house in or near Ay; 'for amongst all the great affairs of state which these princes had to unravel, supplying themselves with this vintage was not the least of their cares.'[458] Malicious tongues have asserted that they were somewhat suspicious of the honesty of the wine-growers of the district, and, in order to secure a genuine article, deemed it needful to have a commissioner or agent resident on the spot, to superintend the making of the wine set apart for their own consumption.[459] Tradition still points out, on the right of the road from Dizy to Ay, a vineyard called Le Léon, as the one whence the Pope derived his wine, though no traces remain of the vendangeoir built by the Emperor in a coppice above Ay during the siege of Epernay in 1544, and still standing in 1727.[460] The president Bertin du Rocheret has celebrated the partiality of a couple of these potentates for the wine of Ay in some triolets addressed to M. de Senécé, and published in the _Mercure_ in 1728: 'Ay produces the best wine-- I call the world to witness this; Though you may for Reims opine, Ay produces the best wine. It ranks the first, and the most fine St. Evremond has said it is. Ay produces the best wine-- I call the world to witness this. Charles the Fifth was well aware Of this--far better than his friend Adrian in the papal chair; Charles the Fifth was well aware Of this, and so, to get his share, Sought in France his days to end. Charles the Fifth was well aware Of this--far better than his friend. Lest some fraud the juice should mix, And his table thus disgrace, He would his own vintage fix, Lest some fraud the juice should mix. Leo, fearing the like tricks, Bought in Ay a pressing-place, Lest some fraud the juice should mix, And his table thus disgrace.'[461] The wine of Ay ranked at the court of Charles IX. as 'a very pleasant and noble wine;'[462] and even that bigoted uprooter of vines and heresy had a vendangeoir in this stronghold of Protestantism,[463] which the Catholics of the Champagne marched against, singing-- 'Parpaillot d'Ay, T'es bien misérable, T'as quitté ton Di Pour servir le diable; Tu n'auras ni chien, ni chat, Pour te chanter Libera, Et tu mourras mau-chrétien, Toi qu'a maudit Saint Trézain.'[464] [Illustration: HENRI III. (From a painting of the period).] In the reign of Henri III. the wines of Ay--'claret and yellowish, subtile, fine, and in taste very pleasing to the palate, ... yet therewithal such wines as the Greeks call Oligophora, and as will not admit the mixture of much water'[465]--were 'eagerly sought after for the use of kings, princes, and great lords.'[466] At a time when the bulk of the vintage of Burgundy was denounced as rough, sour, and harsh; and that of Bordeaux stigmatised as thick and black; and when good and bad years were allowed to have a considerable influence upon the growths of the Isle of France, the Orleannais, and Anjou, it was admitted that 'the wines of Ay do, for the most part, hold the first and principal place, ... and are, in all good and evil years, found better than any others.'[467] The kings and princes of the day made the wines of Ay their ordinary drink.[468] They flowed freely in the scandalous orgies with which the French Heliogabalus and his _mignons_ alternated their pious flagellations and solemn processions, and mantled in the beakers over which the chiefs of the League sat in dark and solemn conclave; they were quaffed by the Béarnais to the bright eyes of the fair De Saulve, and cheered the nightly vigils of Catherine de Medicis and Ruggieri; they sharpened the biting wit of Chicot, and spurred the plotting spirit of Francis of Anjou. Guise and Crillon, Joyeuse and D'Epernon, Mayenne and D'Aubigné made common cause in recognising their merits; Quelus and Maugiron may have quaffed a goblet before setting forth on their fatal journey to the Barrière Saint Antoine; and a cup, filled by the fair hands of the Duchess de Montpensier, may have fired the brain and nerved the arm of the regicide Jacques Clément. [Illustration: OLD HOUSE AT AY, KNOWN AS THE VENDANGEOIR OF HENRI QUATRE.] Henri Quatre boasted the merits of his vineyard at Prepaton, near Vendôme, when he was only King of Navarre,[469] and delighted in the wine of Arbois.[470] At Ay, within a few yards of the church, there is a quaint old timber house traditionally known as the 'vendangeoir d'Henri Quatre,' with obliterated carved escutcheons on the pillars of its doorway. In this dilapidated yet interesting structure we have a mute but certain testimony to the King's appreciation of the wine of Ay, if not a confirmation of the truth of the assertion that Henri was as proud of his title of Seigneur d'Ay as of that of King of France.[471] Giving an audience to the Spanish ambassador, and irritated at the long list of titles appended by the punctilious hidalgo to his royal master's name, he exclaimed: 'You will say to his Highness Philip, King of Spain and the Indies, Castille, Leon, Arragon, Murcia, and the Balearic Isles, that Henri, Sieur of Ay and of Gonesse ...,' being the places producing the best wine and the whitest bread in France.[472] When encamped at Damery, during the siege of Epernay, this favourite beverage, and the smiles of the fair Anne Dudey, Présidente du Puy, helped to relieve the tedium of campaigning; for, as Bertin du Rocheret has sung, 'Our great Henry, king benign, With it cheered his "belle hôtesse." When at Damery he'd dine, Our great Henry, king benign, Chose it for his favourite wine; And for bread, that of Gonesse Our great Henry, king benign, With it cheered his "belle hôtesse."'[473] With the vintage of Ay in such universal esteem, it is scarcely to be wondered at that Dominicus Baudius, professor of eloquence at the University of Leyden and historiographer to the States of the Netherlands, should, in the fulness of his admiration, have declared to his friend the Président du Thou that instead of _vin d'Ay_ it ought to be called _vinum Dei_.[474] Olivier de Serres, the French Tusser, praises this divine liquor.[475] The anonymous author of the _Hercule Guepin_, a poem penned at the commencement of the seventeenth century in honour of the wine of Orleans, is forced to acknowledge the merits of that of Ay;[476] and that indefatigable commentator, the Abbé de Marolles, in a note to his edition of Martial, classes the growths of Ay, Avenay, and Epernay amongst the best that France produced. 'Vive le bon vin d'Ay!' exclaims Guy Patin enthusiastically; and that strange compound of the wit and the philosopher, St. Evremond, has extolled its qualities in prose and verse.[477] 'If you ask me which wine of all others I prefer,' he writes from London to the Count d'Olonne, about 1671, 'without yielding to tastes introduced by people of sham daintiness, I will answer that good wine of Ay is the most natural of all wines, the most healthy, the best purified from all earth smack; of a most exquisite charm, through the peach flavour which is peculiar to it; and is, in my opinion, the finest of all flavours.'[478] It is improbable that the wine of Ay of Francis I., or of Henri Quatre, was _mousseux_, for had it been so history would have mentioned it. In good years the still wine of Ay has a bouquet and perfume sufficient to account for its ancient reputation. Neither was the wine St. Evremond preferred sparkling, though his reference to the taste introduced by sham _gourmets_ points probably to the custom of drinking the wine before its fermentation was completed, or else to the practice of icing it. When once, however, the introduction of _vin mousseux_ added a new charm to the pleasures of the table, the poets who sang the praises of the foaming nectar seem one and all to have celebrated it as the 'pétillant Ay,' and to have chosen, perhaps for euphonistic reasons, that spot as its birthplace.[479] The material results were equally satisfactory; for Arthur Young mentions that when, on July 8, 1787, he visited 'Ay, a village not far out on the road to Reims very famous for its wines,' he was provided with a letter for M. Lasnier, who had 60,000 bottles in his cellar, whilst M. Dorsé had from 30,000 to 40,000.[480] A century ago the foregoing were no doubt considered large stocks, but to-day the very smallest of the Ay firms would think itself poorly provided if its cellars contained under quadruple this quantity. The largest Champagne establishment at Ay is that of Messrs. Deutz & Geldermann, whose extra dry 'Gold Lack' and 'Cabinet' Champagnes have long been favourably known in England, through the energetic exertions of their agents, Messrs. J. R. Parkington & Co., of Crutched Friars. The Ay firm have their offices in a massive-looking corner-house at the further extremity of the town, in the direction of the steep hills sheltering it on the north. This forms their central establishment, and here are spacious celliers for disgorging and finishing off the wine, a large packing-hall, and rooms where bales of corks and other accessories of the trade are stored, the operations of making the cuvées and bottling being accomplished in an establishment some little distance off. On proceeding thither, we find an elegant château with a charming terraced garden, lying at the very foot of the vine-clad slopes, and on the opposite side of the road some large celliers where wine in wood is stored, and where the cuvées of the firm, consisting usually of upwards of 50,000 gallons each, are made in a vat of gigantic proportions, furnished with a raised platform at one end for the accommodation of the workman who agitates the customary paddles. When the wine is completely blended it is drawn off into casks disposed for the purpose in the cellar below, as shown in the accompanying engraving, and after being fined it rests for about a month to clear itself. To each of these casks of newly-blended wine a portion of old wine is added separately, and at the moment of bottling the whole is newly amalgamated. [Illustration: DRAWING OFF THE CUVÉE AT DEUTZ AND GELDERMANN'S, AY.] Adjoining M. Deutz's château is the principal entrance to the extensive cellars of the firm, to which, at our visit in 1877, considerable additions were being made. In excavating these cellars in the chalk a uniform system is pursued. The workmen commence by rounding off the roof of the gallery, and then proceed to work gradually downwards, extracting the chalk, whenever practicable, in blocks suitable for building purposes, which, being worth from three to four shillings the square yard, help to reduce the cost of the excavation. When any serious flaws present themselves in the sides or roof of the galleries, they are invariably made good with masonry. This splendid range of cellars now comprises eight long and lofty galleries no less than seventeen feet wide, and the same number of feet in height, and of the aggregate length of 2200 yards. These spacious vaults, which run parallel with each other, and communicate by means of cross passages, underlie the street, the château, the garden, and the vineyard slopes beyond, and possess the great advantage of being always dry. They are capable, we were informed, of containing several million bottles of Champagne, in addition to a large quantity of wine in cask. Messrs. Deutz & Geldermann possess vineyards at Ay, and own a large vendangeoir at Verzenay, where in good years they usually press 500 pièces of wine. They, moreover, make large purchases of grapes at Bouzy, Cramant, Le Mesnil, Pierry, &c., and invariably have these pressed under their own superintendence. Beyond large shipments to England, where their wine is deservedly held in high estimation, Messrs. Deutz & Geldermann transact a considerable business with other countries, and more especially with Germany, in which country their brand has been for years one of the most popular, while to-day it is the favourite at numerous regimental messes and the principal hotels. Within a hundred yards of the open space, surrounded by houses of different epochs and considerable diversity of design, where the Ay market-hall stands, and in one of those narrow winding streets common to the town, an escutcheon, with a bunch of grapes for device, surmounting a lofty gateway, attracts attention. Beyond, a trim courtyard, girt round with orange-trees in bright green boxes, and clipped in orthodox fashion, affords access to the handsome residence and offices of M. Duminy, well known in England and America as a shipper of high-class Champagnes, and whose Parisian connection is extensive. On the right-hand side of the courtyard is the packing-room; and through the cellars, which have an entrance here, one can reach the celliers in an adjoining street, where the cuvée is made and the bottling of the wine accomplished. [Illustration: THE EXCAVATION OF DEUTZ AND GELDERMANN'S NEW CELLARS AT AY.] M. Duminy's cellars are remarkably old, and consequently of somewhat irregular construction, being at times rather low and narrow, as well as on different levels. In addition, however, to these venerable vaults, packed with wines of 1874 and '78, M. Duminy has a new and extensive establishment on the outskirts of Ay, as well as various subterranean adjuncts in the town itself. This new establishment, which stands under the vineclad slope, and merely a stone's throw from the railway line to Reims, consists of a large ornamental building looking on to a spacious courtyard ordinarily alive with busy workpeople. In addition to the pavilion already erected, it is intended to construct one of similar design, and to connect the two with a monumental tower. The requisite land has already been purchased, the architectural plans are prepared, and the work is now in active progress. [Illustration] Entering the courtyard of which we have spoken, we notice the new offices of the firm on the left hand, and extending along the wall beyond is a long zinc-roofed shed, crowded with baskets filled with newly-purchased Champagne bottles. On the opposite side of the courtyard is a building in which the operation of bottle-washing is carried on. The pavilion in the rear of the courtyard is of somewhat monumental proportions, and is ornamented with dressings of white stone and red brick. Entering through the principal doorway, we find ourselves in a vast cellier, where the packing operations are carried on, and where are a couple of huge tuns in which the cuvées of the house are made. A stone staircase conducts to an upper cellier, where several hundred casks of _vin brut_ are stored, and for the raising or lowering of which lifts are provided at stated distances. In an apartment above this second cellier straw envelopes for bottles and other accessories employed in the trade are kept. [Illustration: M. DUMINY'S NEW ESTABLISHMENT AT AY.] The cellars extend, not merely beneath this large building and the courtyard in front, but run under the adjacent mountain-slope. They comprise four galleries on the same level, vaulted and faced with brick or stone, each gallery being about 500 feet in length and upwards of twelve feet in width and height. Eight transverse passages connect these galleries with each other, and numerous lifts communicate with the cellier and the courtyard above. The galleries that run under the vineyard slope are ventilated by shafts no less than 120 feet in height. M. Duminy has already provided room here for a million bottles of sparkling wine; and it is estimated that, when the establishment is completed, two and a half millions of bottles can be stored here in addition to the stock contained in the old cellars possessed by M. Duminy in the town. During its two-thirds of a century of existence the house has invariably confined itself to first-class wines, taking particular pride in shipping fully-matured growths. Besides its own large reserve of these, it holds considerable stocks long since disposed of, and now merely awaiting the purchasers' orders to be shipped. [Illustration] A few paces beyond M. Duminy's we come upon an antiquated, decrepit-looking timber house, with its ancient gable bulging over as though the tough oak brackets on which it rests were at last grown weary of supporting their unwieldy burden. Judging from the quaint carved devices on the timbers at the lower portions of this building, one may imagine it to have been the residence of an individual of some importance in the days when the principal European potentates had their commissioners installed at Ay to secure them the finest vintages. The house evidently dates back to this or to an earlier epoch. [Illustration: ANCIENT TIMBER HOUSE AT AY.] The cellars of Messrs. Pfungst Frères et Cie. are situated some little distance from the vineyard owned by them at Ay. The firm lay themselves out exclusively for the shipment of high-class Champagne, and the excellent growths of this district necessarily form an important element in their carefully-composed cuvées. A considerable portion of their stock consists of reserves of old wine of grand years; and a variety of samples of finely-matured Champagnes were submitted to our judgment. All of these wines were of superior quality, combining delicacy and fragrance with dryness, the latter being their especial feature. In addition to their business with England, where the brand of the firm is rapidly increasing in popularity among connoisseurs of matured wines, Messrs. Pfungst Frères ship largely to India and the United States. [Illustration: CAPITALS AND MOULDINGS IN AY CHURCH.] On the northern side of the town stands the handsome Gothic church of Ay, dating from about the middle of the fifteenth century. The existing building replaced the edifice erected some two hundred years previously, and traces of which are still to be seen in the present transept. The stone tower, which is in striking contrast with the other portions of the structure, bears the date 1541 on its western face. This tower and the interior of the church were greatly damaged by the fire--traditionally ascribed to lightning--which occurred at the close of the sixteenth century, and the former had to be strengthened by filling up the arched windows and by the addition of buttresses. The bell, whose terrible tocsin used to warn good citizens that the _patrie_ was in danger in the days of the Revolution, when the church was converted into a Temple of Reason, had previously swung in the abbey of Hautvillers, and may have summoned the vintagers to labour as well as the faithful to prayer. From 1867 to 1877 extensive interior repairs and restorations, costing upwards of 6000_l._, greatly transformed the interior of the church. Care was, however, taken to preserve the numerous bits of mediæval and Renaissance sculpture with which both the interior and exterior of the edifice were studded. In many of the ornamental mouldings, as well as the capitals of the columns, grape-laden vine-branches had been freely introduced, as if to indicate the honour in which the vine, the material source of all the prosperity enjoyed by the little town, was held both by mediæval and later architects; and these appear all to have been scrupulously restored. One of the most characteristic decorations of this character is the sculptured figure of a boy bearing a basket of grapes upon his head, which surmounts the handsome Renaissance doorway. [Illustration: MOULDINGS FROM AY CHURCH.] Within half an hour's walk of Ay, in an easterly direction, is the village of Mareuil, a long straight street of straggling houses, bounded by trees and garden-plots, with vine-clad hills rising abruptly behind on the one side, and the Marne canal flowing placidly by on the other. The archaic church, a mixture of the Romanesque and Early Gothic, stands at the farther end of the village, and some little distance on this side of it is a massive-looking eighteenth-century building, spacious enough to accommodate a regiment of horse, but conventual rather than barrack-like in aspect, from the paucity of windows looking on to the road. A broad gateway leads into a spacious courtyard, to the left of which stands a grand château; while on the right there rises an ornate round tower of three stories, from the gallery on the summit of which a fine view over the valley of the Marne is obtained. The buildings, enclosing the court on three sides, comprise press-houses, celliers, and packing-rooms, an antiquated sun-dial marking the hour on the blank space above the vines that climb beside the entrance gateway. The more ancient of these tenements formed the vendangeoir of the Dukes of Orleans at the time they owned the château of Mareuil, purchased in 1830 by the Duke de Montebello, son of the famous Marshal Lannes, and minister and ambassador of Louis Philippe and Napoleon III. The acquisition of this property, to which were attached some important vineyards, led, several years later, to the duke's founding, in conjunction with his brothers, the Marquis and General Count de Montebello, a Champagne firm, whose brand speedily acquired a notable popularity. To-day the business is carried on by their sons and heirs, for all the original partners in the house have followed their valiant father to the grave. Struck down by an Austrian cannon-ball in the zenith of his fame, the career of Marshal Lannes, brief as it was, furnishes one of the most brilliant pages in French military annals. Joining the army of Italy as a volunteer in 1796, he was made a colonel on the battle-field in the gorges of Millesimo, when Augereau's bold advance opened Piedmont to the French. He fought at Bassano and Lodi, took part in the assault of Pavia and the siege of Mantua, and at Arcola, when Napoleon dashed flag in hand upon the bridge, Lannes was seriously wounded whilst shielding his general from danger. He afterwards distinguished himself in Egypt, and led the van of the French army across the Alps, displaying his accustomed bravery both at Montebello and Marengo. At Austerlitz, where he commanded the right wing of the army, he greatly contributed to the victory; and at Jena, Friedland, and Eylau his valour was again conspicuous. Sent to Spain, he defeated the Spaniards at Tudela, and took part in the operations against Saragossa. Wounded at the battle of Essling, when the Archduke Charles inflicted upon Napoleon I. the first serious repulse he had met with on the field of battle, the valiant Lannes expired a few days afterwards in the Emperor's arms. [Illustration: THE MONTEBELLO ESTABLISHMENT AT MAREUIL.] We were met at Mareuil, on the occasion of our visit, by Count Alfred Ferdinand de Montebello, the present manager of the house, and conducted by him over the establishment. In the press-house, to the left of the courtyard, were two of the ponderous presses used in the Champagne, for, like all other large firms, the house makes its own wine. Grapes grown in the Mareuil vineyards arrive here in baskets slung over the backs of mules, muzzled, so that while awaiting their loads they may not devour the fruit within reach. In a cellier adjoining the press-house stands a large vat, capable of holding fifty pièces of wine, with a crane beside it for hauling up the casks when the cuvée is made. Here the tirage likewise takes place; and in the range of buildings roofed with glass, in the rear of the tower, the bottled wine is labelled, capped with foil, and packed in cases for transmission to Paris, England, and other places abroad. A double flight of steps, decorated with lamps and vases, leads to the handsome offices of the firm, situated on the first-floor of the tower; while above is an apartment with a panelled ceiling, gracefully decorated with groups of Cupids engaged in the vintage and the various operations which the famous wines of the Mountain and the River undergo during their conversion into Champagne. On the ground-floor of the tower a low doorway conducts to the spacious cellars, which, owing to the proximity of the Marne, are all on the same level as well as constructed in masonry. The older vaults, where the Marquis de Pange, a former owner of the château, stored the wine which he used to sell to the Champagne manufacturers, are somewhat low and tortuous compared with the broad and lofty galleries of more recent date, which have been constructed as the growing connection of the firm obliged them to increase their stocks. Spite, however, of numerous additions, portions of their reserves have to be stored in other cellars in Mareuil. Considerable stocks of each of the four qualities of wine supplied by the firm are being got ready for disgorgement, including Cartes Noires and Bleues, with the refined Carte Blanche and the delicate Crêmant, which challenge comparison with brands of the highest repute. [Illustration: CHÂTEAU OF MAREUIL, BELONGING TO THE DUKE OF MONTEBELLO.] In the adjacent château, the gardens of which slope down to the Marne canal, there are various interesting portraits, with one or two relics of the distinguished founder of the Montebello family, notably Marshal Lannes's gold-embroidered velvet saddle trappings, his portrait and that of Marshal Gerard, as well as one of Napoleon I., by David, with a handsome clock and candelabra of Egyptian design, a bust of Augustus Cæsar, and a portrait of the Regent d'Orleans. [Illustration: GENERAL VIEW OF AVIZE.] XII. /Champagne Establishments at Avize and Rilly./ Avize the centre of the white grape district--Its situation and aspect--The establishment of Giesler & Co.--The tirage and the cuvée--Vin Brut in racks and on tables--The packing-hall, the extensive cellars, and the disgorging cellier--Bottle stores and bottle-washing machines--Messrs. Giesler's wine-presses at Avize and vendangeoir at Bouzy--Their vineyards and their purchases of grapes--Reputation of the Giesler brand--The establishment of M. Charles de Cazanove--A tame young boar--Boar-hunting in the Champagne--M. de Cazanove's commodious cellars and carefully-selected wines--Vineyards owned by him and his family--Reputation of his wines in Paris and their growing popularity in England--Interesting view of the Avize and Cramant vineyards from M. de Cazanove's terraced garden--The vintaging of the white grapes in the Champagne--Roper Frères' establishment at Rilly-la-Montagne--Their cellars penetrated by roots of trees--Some samples of fine old Champagnes--The principal Châlons establishments--Poem on Champagne by M. Amaury de Cazanove. [Illustration: DOORWAY OF AVIZE CHURCH.] Avize, situated in the heart of the Champagne white grape district, may be reached from Epernay by road through Pierry and Cramant, or by the Châlons Railway to Oiry Junction, between which station and Romilly there runs a local line, jocularly termed the _chemin de fer de famille_, from the general disregard displayed by the officials for anything approaching to punctuality. Avize can scarcely be styled a town, and yet its growing proportions are beyond those of an ordinary village. It lies pleasantly nestled among the vines, sheltered by bold ridges on the north-west, with the monotonous plains of La Champagne pouilleuse, unsuited to the cultivation of the vine, stretching away eastward in the direction of Châlons. Avize cannot pretend to the same antiquity as its neighbour Vertus, and lacks the many picturesque vestiges of which the latter can boast. Its church dates back only to the fifteenth century, although the principal doorway in the Romanesque style evidently belongs to a much earlier epoch. There is a general air of trim prosperity about the place, and the villagers have that well-to-do appearance common to the inhabitants of the French wine districts. Only at vintage-time, however, are there any particular outdoor signs of activity, although half a score of Champagne firms have their establishments here, giving employment to the bulk of the population, and sending forth their two or three million bottles of the sparkling wine of the Marne annually. [Illustration: MAKING THE CUVÉE AT MESSRS. GIESLER'S, AT AVIZE.] Proceeding along the straight level road leading from the station to the village, we encounter on our right hand the premises of Messrs. Giesler & Co., the reputation of whose brand is universal. When M. Giesler quitted the firm of P. A. Mumm, Giesler, & Co., at Reims, in 1838, he removed to Avize, and founded the present extensive establishment. Entering through a large open gateway, we find ourselves within a spacious courtyard, with a handsome dwelling-house in the rear, and all the signs of a Champagne business of magnitude apparent. A spiral staircase conducts to the counting-house on the first story of a range of buildings on the left hand, the ground floor of which is divided into celliers. Passing through a door by the side of this staircase, we enter a large hall where the operation of bottling the wine is going on. Four tuns, each holding five ordinary pièces of wine, and raised upon large blocks of wood, are standing here, and communicating with them are bottling syphons of the type commonly employed in the Champagne. Messrs. Giesler do not usually consign the newly-bottled wine at once to the cellars, but retain it above-ground for about a fortnight, in order that it may develop its effervescent qualities more perfectly. We find many thousands of these bottles stacked horizontally in the adjoining celliers, in one of which stands the great cuvée tun, wherein some fifty hogsheads of the finest Champagne growths are blended together at one time, two hundred hogsheads being thus mingled daily while the cuvées are in progress. The casks of wine having been hoisted from the cellars to the first floor by a crane, and run on to a trough, their bungs are removed, and the wine flows through an aperture in the floor into the huge tun beneath, its amalgamation being accomplished by the customary fan-shaped appliances, set in motion by the turning of a wheel. In an adjacent room is the machine used for mixing the liqueur which Messrs. Giesler add so sparingly to their light and fragrant wines. There are a couple of floors above these celliers, the uppermost of which is used as a general store, while in the one beneath many thousands of bottles of _vin brut_ repose _sur pointe_, either in racks or on tables, as at the Clicquot-Werlé establishment. This latter system requires ample space, for as the workman who shakes the bottles is only able to use one hand, the operation of dislodging the sediment necessarily occupies a much longer time than is requisite when the bottles rest in racks. The buildings on the opposite side of the courtyard comprise a large packing-hall, celliers where the wine is finished off, and rooms where corks and suchlike things are stored. Here, too, is the entrance to the cellars, of which there are three tiers, all lofty and well-ventilated galleries, very regular in their construction, and faced with either stone or brick. In these extensive vaults are casks of fine reserved wines for blending with youthful vintages, and bottles of _vin brut_, built up in solid stacks, that may be reckoned by their hundreds of thousands. At Messrs. Giesler's the disgorging of the wine is accomplished in a small cellier partially underground, and the temperature of which is very cool and equable. The _dégorgeurs_, isolated from the rest of the workpeople, are carrying on their operations here by candlelight. So soon as the sediment is removed, the bottles are raised in baskets to the cellier above, where the liqueuring, recorking, stringing, and wiring are successively accomplished. By pursuing this plan the loss sustained by the disgorgement is believed to be reduced to a minimum. Extensive as these premises are, they are still insufficient for the requirements of the firm; and across the road is a spacious building where new bottles are stored, and the washing of the bottles in preparation for the tirage takes place. By the aid of the machinery provided sixteen women, assisted by a couple of men, commonly wash some fifteen or sixteen thousand bottles in the course of a day. Here, too, stands one of the two large presses with which, at the epoch of the vintage, a hundred pièces of wine are pressed every four-and-twenty hours. The remaining press is installed in a cellier at the farther end of the garden on the other side of the road. Messrs. Giesler possess additional presses at their vendangeoir at Bouzy, and during the vintage have the command of presses at Ay, Verzenay, Vertus, Le Mesnil, &c.; it being a rule of theirs always to press the grapes within a few hours after they are gathered, to obviate their becoming bruised by their own weight and imparting a dark colour to the wine, a contingency difficult to guard against in seasons when the fruit is over-ripe. The firm own vineyards at Avize, and have agreements with vine-proprietors at Ay, Bouzy, Verzenay, and elsewhere, to purchase their crops regularly every year. Messrs. Giesler's brand has secured its existing high repute solely through the fine quality of the wines shipped by the house--wines which are known and appreciated by all real connoisseurs of Champagne. From Messrs. Giesler's it is merely a short walk to the establishment of M. Charles de Cazanove, situated in the principal street of Avize. On entering the court we encountered a tame young boar engaged in the lively pursuit of chasing some terrified hens; while a trio of boar-hounds, basking on the sunny flagstones, contemplated his proceedings with lazy indifference. Boars abound in the woods hereabouts, and hunting them is a favourite pastime with the residents; and the young boar we had noticed proved to be one of the recent captures of the sons of M. de Cazanove, who are among the warmest partisans of the exciting sport. The house of M. Charles de Cazanove was established in 1843, by its present proprietor, on the foundation of a business which had been in existence since 1811. Compared with the monumental grandeur of some of the great Reims and Epernay establishments, the premises present a simple and modest aspect; nevertheless, they are capacious and commodious, besides which, the growing business of the house has led to the acquisition of additional cellarage in other parts of Avize. More important than all, however, is the quality of the wine with which these cellars are stocked; and, following the rule observed by Champagne firms of the highest repute, it has been a leading principle with M. de Cazanove always to rely upon the choicer growths--those light, delicate, and fragrant wines of the Marne which throw out the true aroma of the flower of the vine. M. de Cazanove, who is distinguished for his knowledge of viticulture, occupies an influential position at Avize, being Vice-President of the Horticultural Society of the Marne, and a member of the committee charged with guarding the Champagne vineyards against the invasion of the phylloxera. His own vines include only those fine varieties to which the crus of the Marne owe their great renown. He possesses an excellent vineyard at Grauves, near Avize; and his mother-in-law, Madame Poultier of Pierry, is one of the principal vine-growers of the district. M. de Cazanove's wines are much appreciated in Paris, where his business is very extensive. His shipments to England are also considerable; but from the circumstance of some of his principal customers importing the wine under special brands of their own, the brand of the house is not so widely known as we should have anticipated. [Illustration: VINEYARDS OF AVIZE AND CRAMANT, FROM THE GARDEN OF M. C. DE CAZANOVE.] From M. de Cazanove's terraced garden in the rear of his establishment a fine view is obtained of one of the most famous viticultural districts of the Champagne, yielding wines of remarkable delicacy and exquisite bouquet. On the left hand rises up the mountain of Avize, its summit fringed with dense woods, where in winter the wild-boar has his lair. In front stretch the long vine-clad slopes of Cramant, with orchards at their base, and the housetops of the village and the spire of the quaint old church just peeping over the brow of the hill. To the right towers the bold forest-crowned height of Saran, with M. Moët's château perched half-way up its north-eastern slope; and fading away in the hazy distance are the monotonous plains of the Champagne. We have already explained that the wines of Avize and Cramant rank as _premiers crus_ of the white grape district, and that every Champagne manufacturer of repute mingles one or the other in his cuvée. The white grapes are usually gathered a fortnight or three weeks later than the black varieties, but in other respects the vintaging of them is the same. The grapes undergo the customary minute examination by the _éplucheuses_, and all unripe, damaged, and rotten berries being thrown aside, the fruit is conveyed with due care to the press-houses in the large baskets known as _paniers mannequins_. The pressing takes place under exactly the same conditions as the pressing of the black grapes; the must, too, is drawn off into hogsheads to ferment, and by the end of the year, when the active fermentation has terminated, the wine is usually clear and limpid. At Rilly-la-Montagne, on the line of railway between Reims and Epernay, Roper Frères & Cie., late of Epernay, have their establishment. Starting from the latter place, we pass Ay and Avenay, and then the little village of Germaine in the midst of the forest, and nigh the summit of the mountain of Reims, with its 'Rendezvous des Chasseurs' in immediate proximity to the station. Finally we arrive at Rilly, which, spite of its isolated situation, has about it that aspect of prosperity common to the more favourable wine districts of France. This is scarcely surprising, when the quality of its wines is taken into consideration. The still red wine of Rilly has long enjoyed a high local reputation, and to-day the Rilly growths are much sought after for conversion into Champagne. White wine of 1874, from black grapes, fetched, we are informed, as much as 600 to 700 francs the pièce; while the finer qualities from white grapes realised from 300 to 400 francs. Messrs. Roper Frères & Cie. are the owners of some productive vineyards situated on the high-road to Chigny and Ludes. The establishment of Roper Frères is adjacent to a handsome modern house standing back from the road in a large and pleasant garden, bounded by vineyards on two of its sides. In the celliers all the conveniences pertaining to a modern Champagne establishment are to be found, while extending beneath the garden are the extensive cellars of the firm, comprising two stories of long and spacious galleries excavated in the chalk, their walls and roofs being supported whenever necessary by masonry. A curious feature about these cellars is that the roots of the larger trees in the garden above have penetrated the roof of the upper story, and hang pendent overhead like innumerable stalactites. Here, after the comparatively new wine of 1874 had been shown to us--including samples of the vin brut or natural Champagne of which the firm make a specialty at a moderate price--some choice old Champagnes were brought forth, including the fine vintages of 1865, 1857, and 1846. The latter wine had of course preserved very little of its effervescence, still its flavour was exceedingly fine, being soft and delicate to a degree. At the Vienna Exhibition of 1873, and the London Exhibition of 1874, the collection of Champagnes exhibited by Roper Frères met with favourable recognition from the international juries. Our tour through the Champagne vineyards and wine-cellars here comes to an end. It is true there are important establishments at Châlons, notably those of the Perriers, Freminet et Fils, Dagonet et Fils, and Jacquard Frères. As, however, any description of these would be little else than a recapitulation of something we have already said, we content ourselves with merely notifying their existence, and close the present chapter with a poem on Champagne, from the pen of M. Amaury de Cazanove of Avize: ODE AU CHAMPAGNE. Pour ta beauté, pour ta gloire, ô Patrie, Nous t'adorons ... surtout pour tes malheurs! Oublions-les.... Avec idolâtrie, Chantons ton ciel, tes femmes et tes fleurs. France, nous chanterons tes femmes et tes roses; France, nous chanterons tes vins, autre trésor; Qu'on voie, ouvrant tes lèvres longtemps closes, Un fier sourire étinceler encor! Nectar qu'aux dieux jadis versait Hébé la blonde! O noir Falerne! ô Massique vermeil! Pauvres vins du vieux temps oubliés à la ronde ... Car le Champagne a fait le tour du monde En conquérant, à nos drapeaux pareil; Il rit, léger, sous la mousse qui tremble, Et semble Dans le cristal un rayon de soleil. 'Je suis le sang des coteaux de Bourgogne!' Dit celui-là baron à parchemin, Grand assommeur qui vous met sans vergogne Son casque au front, si lourd le lendemain.... 'C'est moi l'exquis Bordeaux, je sens la violette; Mes rubis, le gourmet goutte à goutte les boit, Et mon parfum délicat se complète Par ta saveur, aile d'un perdreau froid.' Messeigneurs les Grand Vins, s'il faut qu'on vous réponde; Bordeaux, Bourgogne, écoutez un conseil: Vantez un peu moins fort vos vertus à la ronde.... Car le Champagne a fait le tour du monde En conquérant, à nos drapeaux pareil; Il rit, léger, sous la mousse qui tremble, Et semble Dans le cristal un rayon de soleil. Car le Champagne est le vrai vin de France; C'est notre c[oe]ur pétillant dans nos yeux, Se relevant plus haut sous la souffrance; C'est dans sa fleur l'esprit de nos aïeux; Le souffle de bravoure aimable, qui tressaille Sous le vent de l'épée aux plumes des cimiers; C'est le galant défi de la bataille: 'A vous, Messieurs les Anglais, les premiers!' Certain buveur de bière en vain ricane et gronde; Aux cauchemars de ses nuits sans sommeil Dieu livre ses remords! ... Nous chantons à la ronde Que le Champagne a fait le tour du monde En conquérant, à nos drapeaux pareil; Il rit, léger, sous la mousse qui tremble, Et semble Dans le cristal un rayon de soleil.[481] Avize, 8 Juillet 1877. [Illustration] [Illustration: THE BOAR TAKES SOIL.] XIII. /Sport in the Champagne./ The Champagne forests the resort of the wild-boar--Departure of a hunting-party in the early morning to a boar-hunt--Rousing the boar from his lair--Commencement of the attack--Chasing the boar--His course is checked by a bullet--The dogs rush on in full pursuit--The boar turns and stands at bay--A skilful marksman advances and gives him the _coup de grâce_--Hunting the wild-boar on horseback in the Champagne--An exciting day's sport with M. d'Honnincton's boar-hounds--The 'sonnerie du sanglier' and the 'vue'--The horns sound in chorus 'The boar has taken soil'--The boar leaves the stream, and a spirited chase ensues--Brought to bay, he seeks the water again--Deathly struggle between the boar and a full pack of hounds--The fatal shot is at length fired, and the 'hallali' is sounded--As many as fifteen wild-boars sometimes killed at a single meet--The vagaries of some tame young boars--Hounds of all kinds used for hunting the wild-boar in the Champagne--Damage done by boars to the vineyards and the crops--Varieties of game common to the Champagne. The Champagne does not merely comprise vineyards producing some of the finest wine in the world. In parts it is covered by vast and luxuriant forests, where the pleasures of the chase are not lacking to the Champenois, who as a rule are eager in the pursuit of sport. In winter these forests are the resort of wild-boar, who haunt by preference the woods around Reims, journeying thither, it is said, by night from the famous forest of the Ardennes--the scene of Rosalind's wanderings and Touchstone's eccentricities, as set forth in _As You Like It_; and whose gloomy depths and tangled glens shelter not merely boars, but wolves as well. [Illustration] In the villages of the Champagne on a cold winter's morning, with it snowing or blowing, you are frequently awake before daylight by the noise of barking dogs, of horns sounding the departure, and of some vehicle rolling heavily over the stones. A party of sportsmen is proceeding to the meet. Jokes and laughter enliven the journey, but every one becomes silent and serious upon reaching the place of rendezvous, for the object of the gathering is the excitable and perilous boar-hunt. In the Champagne it is no longer the fashion, as in Burgundy, 'With javelin's point a churlish swine to gore.' The more certain rifle is the weapon usually employed, and these arms are now examined and carefully loaded. Meanwhile the reports of the keepers are attentively listened to. They have beaten the wood, each on his own side, accompanied by a bloodhound, and they inform the hunters what they have seen or found. Great experience is necessary to accomplish the _rembuchement_, as this tour of inspection is termed, in a satisfactory manner; and with some it is a veritable science. Eventually, after a discussion among the more experienced ones, it is decided to follow the scent which appears to be freshest; whereupon the dogs are brought up coupled, and let loose upon the trail. The attack now begins. There are always two or three _piqueurs_ who follow the dogs, exciting them with their voices, and making all the noise possible, as long as the game has not been roused from its lair. Meanwhile the marksmen place themselves at the posts indicated by the president of the hunt, the most experienced being assigned the best spots, whilst those whose habit it is never to harm the boar go of their own accord 'up wind'--that is, to bad places--thus causing the animal to 'refuse,' and to pass within range of guns that rarely let him escape unhurt. At first the dogs raise a somewhat distant cry--perhaps one has followed a wrong scent--and some of the huntsmen remark in a low tone to themselves that after all they would have done better to have stopped at home, and turned out of their beds at a less unseasonable hour; then, at least, they would not be standing with frozen feet in the snow, and with colds in the head in perspective. But suddenly there comes a cry of 'Vlô!'--the Champenois expression for designating the boar--'Attention!' 'Look out!' Then the report of a couple of shots, and finally the howling of the pack of dogs. Snow and cold are at once forgotten. Each man grasps his rifle and waits for the boar to pass by. The branches of the underwood creak and break; there is a noise as of a squadron of cavalry dashing into a wood; then, all of a sudden, a black mass is caught sight of approaching. But the boar is a cunning fellow; he has seen the sportsman who is in wait for him, or has scented his presence, and will pass out of range. Now that luck has betrayed the latter, he has to content himself with the _rôle_ of a spectator. So far as one can judge by the barking of the dogs, the boar is directing his course to where an experienced marksman is posted--one who is not about to fire his first difficult shot. Observe him: he is perfectly motionless, for the least movement might betray his presence; his eyes alone dart right and left in quest of the foe. Here comes the boar, passing like a cannon-ball along the line, and there is scarcely time to catch a glimpse of him between the reports of two shots, which succeed each other with the rapidity of lightning. The boar is by no means an animal easy to knock over. The forest roads are never more than ten to fifteen paces broad; and as there are marksmen both on the right and left, it is necessary to reserve your fire until the animal has crossed the road and is plunging again into cover. In addition to this, there are only two spots where a mortal wound can be inflicted upon the boar--either behind the shoulder or in the neck. Hit elsewhere, he will lose but little blood, and the only effect of the wound will be to render him more savage. He will rip up a dog or two, perhaps, and then rush off far away, without showing any further sign of injury. Boars carrying several bullets in their bodies, but rejoicing in capital health, as well as others covered with cicatrices, are frequently killed. Firing too high is a common fault with many marksmen, arising from the fact that in winter the boar's bristles are very long and thick, and that each one stands on end at the sight of an enemy, thus making the animal look much higher on his legs than he really is. But to return to our description of the hunt. The boar has just been hit by one of those rare marksmen, every bullet of whose rifle goes straight to its intended billet. Although struck, the animal continues his onward course, a couple of drops of blood which have tinged the snow with red showing unmistakably that he has not been missed. The dogs who follow him closely hesitate for a minute as they reach the roadway, but the leader has espied the spot where the boar was wounded; he sniffs the blood, and darts off again, followed by the pack, who have full confidence in his discernment. The dogs are torn and wounded by the thorns and briers which continually obstruct their path, for the boar rushes through the thickest and most inaccessible cover, in hopes of retarding the progress of his pursuers; but the hounds divine that their prey is near, and the most tired among them recover all their energy. Suddenly a great silence succeeds the furious yelping and baying of a short time ago. The boar is about to turn at bay. His strength is becoming exhausted, and feeling that he is doomed to die, he has faced round, with his back towards some inaccessible thicket, so as not to be taken in the rear, and confronts his pursuers, determined to die bravely and to sell his life dearly. It is no longer the baying of a pack in full cry that now rends the air, but isolated yelpings and plaintive howlings, such as watch-dogs give vent to when strangers are wandering round the house they protect. Then comes the crowning feat of the hunt, and the most difficult to accomplish. The most intrepid marksman advances towards the dogs, his hunting-knife and rifle alike ready, the former to be made use of should the latter not suffice. He has need of great prudence and great coolness to accomplish his task, for directly the boar hears his approach he will unhesitatingly dash upon him. He must await the animal's onslaught with a firm heart and steady hand, and only fire when sure of his aim. Often, however, the hunter is bothered by the dogs, which surround the boar on all sides, hang on to him from behind, and excite his fury. The position may become critical, and many a sportsman who has counted too much upon his nerve has found himself compelled to climb a tree, whence he has been able to 'bowl over' the enemy, without incurring any danger. It is needless to add that when discovered in this position he has felt very much ashamed at having resorted to such an expedient. In the Champagne the wild boar is almost invariably pursued on foot, the minute subdivision of the land into different holdings and consequent limitation of the right of sport rendering it very difficult to follow the animal on horseback. M. Roederer, it is true, started a pack of hounds in the Forest of Reims; but at his death there were not sufficient lovers of the chase to keep up this style of sport, and every one fell into the habit of knocking over a wild-boar in the same prosaic fashion as a simple rabbit. However, some few years back, a rich landowner from Brittany, the Vicomte d'Honnincton, having had an opportunity of sport in the Champagne, and having seen that large game abounded, installed himself near the fine Forêt de la Traconne, in the neighbourhood of Sézanne, and resumed the chase of the wild-boar on horseback. The great success he met with induced him to take up his quarters in this district, and his pack, composed of a cross between the English staghound and the Artois hound, has become justly famous. In the month of December 1878, an exciting day's sport was had with M. d'Honnincton's boar-hounds. The presence of herds of wild-boar having been noted in the neighbouring woods between Epernay and Montmort, M. d'Honnincton was soon to the fore with his pack, and all the sportsmen for miles around were summoned. The meet was at the Château de la Charmoye, a regular hunters' rendezvous, belonging to the Vicomte de Bouthylliers, and situate in the heart of the woodland. During breakfast one of the huntsmen came to announce that a huge _solitaire_ had passed the night at a short distance from the château. Everything, therefore, promised well for sport. The guests mounted in haste, each one equipped in true French style, with an immense hunting-horn round his body and a light gun or a pistol attached to the saddle. The lively strains of the horn had begun to sound on every side, and the hounds were being uncoupled, when the boar, disturbed by all this noise, majestically traversed the main avenue of the château, and pushed on towards a group of ladies assembled to witness the departure of the sportsmen. A finer start would have been impossible. The hounds dashed towards their prey as soon as they caught sight of him at full cry, and the _sonnerie du sanglier_ and the _vue_ were blazed forth by the horns on every side. The hunt commenced. The greatest difficulty and the object of all was to hinder the boar from plunging into the thick of the forest, where, in the dense cover, he would have gained a considerable advance upon the dogs. Thanks to the activity of the huntsmen, who cut off his retreat on this side, it was possible to drive him towards the plain of Montmort; and from this moment the sport was as fine as can be imagined, it being easy to note the minor details of the hunt even from a distance. The boar made his way with difficulty over the ground saturated by rain, and the eagerness of the hounds increased in proportion as they gained upon him. A broadish rivulet with very steep banks was reached. The boar tried to clear it at a bound, but fell into mid-stream. The sportsmen all came up at this moment, and with their horns began to sound in chorus 'The boar has taken soil;' the hounds plunged in and began to swim after the boar, and the scene became a truly exciting one. At length the boar succeeded in quitting the stream; but frightened by the horsemen whom he saw on the opposite shore, he recrossed it a second and then a third time, amidst the hounds, who were assailing him on every side, and each time met with the same difficulty in ascending the bank. It may be readily understood that he was getting exhausted by his efforts, and began to appear done up. He recovered his vigour, however, and soon gained ground on the hounds. He had still two or three miles to cover in order to regain the forest, and it was necessary at all costs to prevent him from accomplishing this. Then ensued a wild hunt, a mad steeplechase over fields, hedges, brooks, ditches; the horses in several places sank over their hocks, and were covered with foam, but whip and spur restored energy to the least ardent. The boar was gasping, but still kept on, and the steam from his body, which quite surrounded him and caused him to resemble a four-legged demon, could be plainly perceived from a distance. In this style the hunt swept through the little village of Lucy, with all the dogs of the place howling, the women and children shrieking, and the men arming themselves with spades and pitchforks. But the boar not losing courage on this account, and despising these primitive weapons, did not stop, and drew nearer and nearer to the wood. The hounds were getting tired, and the most experienced sportsmen began to despair somewhat of a successful day, when suddenly the beast plunged into a pond situate close to the forest, halted, rolled several times in the mud, and rose completely covered in steam and mire. It is all over: the animal is at bay, and cannot go any further. This is the interesting moment. The boar pulls himself together, feeling that he is to die, and, up to his belly in water, he bravely awaits the pack. With his eye glowing with rage, his bristles erect, he utters grunts of defiance. The fifty dogs throw themselves on to him without a moment's hesitation; but four or five are sent rolling into the middle of the water, never more to rise. The struggle which follows is terrible; the boar's tusks tell at every blow, and the water becomes literally red with blood. At length the foremost sportsmen come up, and it is high time they do. Seven dogs are already lying on their backs, with their legs in the air, and almost all bear marks of the boar's terrible tusks. The first who is ready alights from his steed, and boldly advances into the water; for it would be imprudent to fire at the boar from the edge of the pond, and thereby run the risk of wounding him, and rendering him still more furious, or even of killing one of the dogs, by whom he is surrounded. An interval of solemn silence ensues; the horns only wait for the shot to be fired to sound the _hallali_. The dogs make way in order to let the sportsman advance; the boar draws back a little, and then making a bound recovers all his strength for a rush upon his enemy. Woe to the man who misses him! the boar will give him no quarter. But the sportsman waits for him very quietly, and when he is only two paces from him plants a bullet between his eyes, which lays him dead. The notes of the _hallali_ awake the echoes: never had a hunt been crowned by finer results. The setting sun lighted up the scene, which transpired just below the Château de Montmort, scarcely half a mile off, and the ladies assembled on the terrace of the old château of Sully waved their handkerchiefs in congratulation to the fortunate sportsmen. The foregoing narrative furnishes a good idea of the ordinary method of hunting the wild-boar on horseback in the Champagne, a method which, though offering at times varying details, arising from the size of the animal pursued and the number and strength of the hounds engaged in the chase, presents, on the whole, a general resemblance to the description just given. Some years back boars were far from numerous in the Champagne, hiding themselves, moreover, in inaccessible positions far away in the woods, so that it was necessary to cover a larger extent of ground in order to sight a recent trail. Latterly, however, these animals have multiplied considerably, each sow having seven or eight young ones at a litter, and littering three times a year. In the forests around Reims and Epernay twelve, and even fifteen, boars have been killed during a single hunt. It not unfrequently happens that a herd of fifty, and even a hundred, boars are encountered together, when a veritable massacre often ensues, if the hunting-party only comprises a sufficient number of guns. The victims include at times some sows with young grice, which the hunters frequently try to bring up. One of these little animals, who had been named 'Snow' from having been captured one day when the snow was on the ground, followed his owner about everywhere like the most faithful poodle. His master would often take him into the wood and simulate a hunt with his dogs. Snow, however, possessed vices as well as virtues, and one of his habits was an extremely disagreeable one. Like the rest of his species, he was very fond of rolling himself in the mire, and, on returning home, would proceed to clean himself by rubbing unconcernedly against the dresses of the ladies of the house. One Sunday his master had taken him out for a walk, and as they returned home they passed the church, which the ladies of the locality, arrayed in their richest attire, were just leaving. During his walk Snow had taken two or three mud-baths, and, on meeting the fair devotees of Avize, he thought the occasion a propitious one for cleansing himself. He at once put the idea into practice, employing the silk dresses of the ladies for the purpose. The children who accompanied them were greatly terrified, and rushed shrieking into the adjoining houses, pursued by the gambolling boar, who seemed to greatly enjoy the panic he had caused. As La Fontaine has remarked, 'Rien que la mort n'était capable D'expier son forfait.' So, after such an offence, poor Snow was sentenced to undergo capital punishment, and expiated by death his want of regard for the silk attire of the fair sex. Another boar named 'Scotsman,' and belonging to the same sportsman, was also an amusing fellow. He would stretch himself out in the sun of an afternoon as majestically as the Sultan on his divan, whilst a hen with whom he had contracted a tender friendship kindly relieved him of his parasites. A gentleman of the same district owns two enormous sows, which follow him like greyhounds whenever he rides out. When a friend asks him to step indoors and to refresh or rest himself, he replies: 'I must beg you to excuse me; I have with me _Catherine_ and _Rigolette_, who might inconvenience you.' The friend looks round to see who these interesting young people may be, and his surprise may be imagined when two big swine familiarly place their forepaws upon his shoulders. Several sportsmen of the Champagne possess packs of hounds, and the true boar-hound, the 'dog of black St. Hubert breed,' is really a magnificent animal, with his long pendant ears, his open chest, and broad-backed body. Hounds of the La Vendée and Poitou breeds are also used at boar-hunts. Dogs, though they may be of excellent race, require, however, skilful training before they will hunt the boar. It is necessary they should see several boars killed ere they will venture to tackle this formidable enemy, of which the dog is instinctively afraid. House-dogs, curs, and terriers will at times pursue the boar admirably, and prolong his standing for hours without approaching within range of the beast's tusks, whilst animals of a higher spirit will allow themselves to be ripped up alive, or, if they escape, will not dare to again approach their foe after a first repulse. Since boars became so numerous in the Champagne they have done considerable damage to the crops, a corn or potato field being soon devastated by them. At harvest-time a watch has often to be set for them by night. A few years ago, at the moment of the vintage, people were even compelled to light large fires near the vineyards to scare away these dangerous neighbours. The shooting season in the Champagne extends from the commencement of September till the end of February; but boar-hunting is often prolonged until the first of May, and occasionally _battues_ are organised during the summer. Other four-footed game tenanting the forests of the Champagne are the roe-deer, in tolerable quantity; a few fallow-deer and stags and wolves, which latter are still numerous, spite of the warfare carried on against them. The roe-deer is hunted, like the boar, with hounds; but this easy sport, which does not possess the attraction of danger, is quite neglected when boars are numerous. The forests also give shelter to hares in abundance, martins, wild-cats, and foxes, the latter being rigorously destroyed on account of their depredations. They are stifled by smoke in their holes, or else poisoned or taken in traps. Sportsmen are so numerous in every little village of the Marne, the shooting license only costing five-and-twenty francs, that feathered game has become very rare. The most remarkable specimen is the caimpetière, or small bustard, which exists only in the Champagne and Algeria, and the flesh of which is highly esteemed. Partridges and hares would have entirely disappeared from the plains were it not for the shelter which the vineyards afford them, for woe to him who ventures to shoot among the vines! The vine is as sacred to the Champenois as the mistletoe was to their Gallic forefathers. Great severity is shown in respect to trespassers at the epoch when the vines are sprouting, for each broken bud represents a bunch of grapes, which its owner hoped might realise its weight in gold. [Illustration] [Illustration: THE VINEYARDS OF THE COTEAU DE SAUMUR.] PART III. I. /Sparkling Saumur and Sparkling Sauternes./ The sparkling wines of the Loire often palmed off as Champagne--The finer qualities improve with age--Anjou the cradle of the Plantagenet kings--Saumur and its dominating feudal Château and antique Hôtel de Ville--Its sinister Rue des Payens and steep tortuous Grande Rue--The vineyards of the Coteau of Saumur--Abandoned stone-quarries converted into dwellings--The vintage in progress--Old-fashioned pressoirs--The making of the wine--Touraine the favourite residence of the earlier French monarchs--After a night's carouse at the epoch of the Renaissance--The Vouvray vineyards--Balzac's picture of La Vallée Coquette--The village of Vouvray and the Château of Moncontour--Vernou, with its reminiscences of Sully and Pépin-le-Bref--The vineyards around Saumur--Remarkable ancient Dolmens--Ackerman-Laurance's establishment at Saint-Florent--Their extensive cellars, ancient and modern--Treatment of the newly-vintaged wine--The cuvée--Proportions of wine from black and white grapes--The bottling and disgorging of the wine and finishing operations--The Château of Varrains and the establishment of M. Louis Duvau aîné--His cellars a succession of gloomy galleries--The disgorging of the wine accomplished in a melodramatic-looking cave--M. Duvau's vineyard--His sparkling Saumur of various ages--Marked superiority of the more matured samples--M. E. Normandin's sparkling Sauternes manufactory at Châteauneuf--Angoulême and its ancient fortifications--Vin de Colombar--M. Normandin's sparkling Sauternes cuvée--His cellars near Châteauneuf--Recognition accorded to the wine at the Concours Régional d'Angoulême. [Illustration] After the Champagne, Anjou is the French province which ranks next in importance for its production of sparkling wines. Vintaged on the banks of the Loire, these are largely consigned to the English and other markets, labelled Crême de Bouzy, Sillery and Ay Mousseux, Cartes Noires and Blanches, and the like; while their corks are branded with the names of phantom firms, supposed to be located at Reims and Epernay. As a rule, these wines come from around Saumur; but they are not necessarily the worse on that account, for the district produces capital sparkling wines, the finer qualities of which improve greatly by being kept for a few years. One curious thing shown to us at Saumur was the album of a manufacturer of sparkling wines containing examples of the many hundred labels ticketed with which his produce had for years past been sold. Not one of these labels assigned to the wines the name of their real maker or their true birthplace, but introduced them under the auspices of mythical dukes and counts, as being manufactured at châteaux which are so many 'castles in Spain,' and as coming from Ay, Bouzy, Châlons, Epernay, Reims, and Verzenay, but never by any chance from Saumur. Being produced from robuster growths than the sparkling wines of the Department of the Marne, sparkling Saumur will always lack that excessive lightness which is the crowning grace of fine Champagne; still, it has only to be kept for a few years, instead of being drunk shortly after its arrival from the wine-merchant, for its quality to become greatly improved and its intrinsic value to be considerably enhanced. We have drunk sparkling Saumur that had been in bottle for nearly twenty years, and found the wine not only remarkably delicate, but, singular to say, with plenty of effervescence. [Illustration: STATUE OF RICHARD C[OE]UR DE LION AT FONTEVRAULT.] To an Englishman Anjou is one of the most interesting of the ancient provinces of France. It was the cradle of the Plantagenet kings, and only ten miles from Saumur still repose the bones of Henry, the first Plantagenet, and Richard of the Lion Heart, beneath their elaborate coloured and gilt effigies, in the so-called Cimetière des Rois of the historic Abbey of Fontevrault. The famous vineyards of the Coteau de Saumur, eastward of the town and bordering the Loire, extend as far as here, and include the communes of Dampierre, Souzay, Varrains, Chacé, Parnay, Turquant, and Montsoreau, the last-named within three miles of Fontevrault, and chiefly remarkable through its seigneur of ill-fame, Jean de Chambes, who instigated his wife to lure Bussy d'Amboise to an assignation in order that he might the more surely poignard him. Saumur is picturesquely placed at the foot of this bold range of heights, near where the little river Thouet runs into the broad and rapid Loire. A massive-looking old château, perched on the summit of an isolated crag, stands out grandly against the clear sky and dominates the town, the older houses of which crouch at the foot of the lofty hill and climb its steepest sides. The restored antique Hôtel de Ville, in the Pointed style, with its elegant windows, graceful belfry, and florid wrought-iron balconies, stands back from the quay bordering the Loire. In the rear is the Rue des Payens, whither the last of the Huguenots of this 'metropolis of Protestantism,' as it was formerly styled, retired, converting their houses into so many fortresses to guard against being surprised by their Catholic adversaries. Adjacent is the steep tortuous Grande Rue, of which Balzac--himself a Tourangeau--has given such a graphic picture in his _Eugénie Grandet_, the scene of which is laid at Saumur. To-day, however, only a few of its ancient carved-timber houses, quaint overhanging corner turrets, and fantastically studded massive oak doors, have escaped demolition. The vineyards of the Coteau de Saumur, yielding the finest wines, are reached by the road skirting the river, the opposite low banks of which are fringed with willows and endless rows of poplars, which at the time of our visit were already golden with the fading tints of autumn. Numerous fantastic windmills crown the heights, the summit of which is covered with vines, varied by dense patches of woodland. Here, as elsewhere along the banks of the Loire, the many abandoned quarries along the face of the hill have been turned by the peasants into cosy dwellings by simply walling-up the entrances, while leaving, of course, the necessary apertures for doors and windows. Dampierre, the first village reached, has many of these cave-dwellings, and numbers of its houses are picturesquely perched up the sides of the slope. The holiday costumes of the peasant women encountered in the neighbourhood of Saumur are exceedingly quaint, their elaborate and varied headdresses being counterparts of _coiffures_ in vogue so far back as three and four centuries ago. [Illustration: PEASANT WOMEN OF THE ENVIRONS OF SAUMUR.] Quitting the banks of the river, we ascend a steep tortuous road, shut in on either side by high stone walls--for hereabouts all the best vineyards are scrupulously enclosed--and finally reach the summit of the heights, whence a view is gained over what the Saumurois proudly style the grand valley of the Loire. Everywhere around the vintage is going on. The vines are planted rather more than a yard apart, and those yielding black grapes are trained, as a rule, up tall stakes, although some few are trained espalier fashion. Women dexterously detach the bunches with pruning-knives and throw them into the _seilles_--small squat buckets with wooden handles--the contents of which are emptied from time to time into baskets--the counterpart of the chiffonnier's _hotte_, and coated with pitch inside so as to close all the crevices of the wickerwork--which the _portes-bastes_ carry slung to their backs. When white wine is being made from black grapes for sparkling Saumur, the grapes are conveyed in these baskets to the underground pressoirs in the neighbouring villages before their skins get at all broken, in order that the wine may be as pale as possible in colour. The black grape yielding the best wine in the Saumur district is the breton, said to be the same as the carbinet-sauvignon, the leading variety in the grand vineyards of the Médoc. Other species of black grapes cultivated around Saumur are the varennes, yielding a soft and insipid wine of no kind of value, and the liverdun, or large gamay, the prevalent grape in the Mâconnais, and the same which in the days of Philippe-le-Hardi the _parlements_ of Metz and Dijon interdicted the planting and cultivation of. The prevalent white grapes are the large and small pineau blanc, the bunches of the former being of an intermediate size, broad and pyramidal in shape, and with the berries close together. These have fine skins, are oblong in shape, and of a transparent yellowish-green hue tinged with red, are very sweet and juicy, and as a rule ripen late. As for the small pineau, the bunches are less compact, the berries are round and of a golden tint, are finer as well as sweeter in flavour, and ripen somewhat earlier than the fruit of the larger variety. We noticed as we drove through the villages of Champigny and Varrains--the former celebrated for its fine red wines, and more especially its cru of the Clos des Cordeliers--that hardly any of the houses had windows looking on to the narrow street, but that all were provided with low openings for shooting the grapes into the cellar, where, when making red wine, they are trodden, but when making white wine, whether from black or white grapes, they are invariably pressed. Each of the houses had its ponderous porte-cochère and low narrow portal leading into the large enclosed yard at its side, and over the high blank walls vines were frequently trained, pleasantly varying their dull gray monotony. The grapes on being shot into the openings just mentioned fall through a kind of tunnel into a reservoir adjacent to the heavy press, which is invariably of wood and of the old-fashioned cumbersome type. They are forthwith placed beneath the press and usually subjected to five separate squeezes, the must from the first three being reserved for sparkling wine, while that from the two latter, owing to its being more or less deeply tinted, only serves for table-wine. The must is at once run off into casks, in order that it may not ferment on the grape-skins and imbibe any portion of their colouring matter. Active fermentation speedily sets in, and lasts for a fortnight or three weeks, according to whether the temperature chances to be high or low. The vintaging of the white grapes takes place about a fortnight later than the black grapes, and is commonly a compound operation, the best and ripest bunches being first of all gathered just as the berries begin to get shrivelled and show symptoms of approaching rottenness. It is these selected grapes that yield the best wine. The second gathering, which follows shortly after the first, includes all the grapes remaining on the vines, and yields a wine perceptibly inferior in quality. The grapes on their arrival at the press-house are generally pressed immediately, and the must is run off into tuns to ferment. At the commencement these tuns are filled up every three or four days to replace the fermenting must which has flowed over; afterwards any waste is made good at the interval of a week, and then once a fortnight, the bungholes of the casks being securely closed towards the end of the year, by which time the first fermentation is over. It should be noted that the Saumur sparkling wine manufacturers draw considerable supplies of the white wine, required to impart lightness and effervescence to their _vin préparé_, from the Vouvray vineyards. Vouvray borders the Loire a few miles from the pleasant city of Tours, which awakens sinister recollections of truculent Louis XI., shut up in his fortified castle of Plessis-lez-Tours, around which Scott has thrown the halo of his genius in his novel of _Quentin Durward_. A succession of vineyard slopes stretch from one to another of the many historic châteaux along this portion of the Loire, the romantic associations of which render the Touraine one of the most interesting provinces of France. Near Tours, besides the vineyards of Saint-Cyr are those of Joué and Saint-Avertin; the two last situate on the opposite bank of the Cher, where the little town of Joué, perched on the summit of a hill in the midst of vineyards, looks over a vast plain known by the country-people as the Landes de Charlemagne, the scene, according to local tradition, of Charles Martel's great victory over the Saracens. The Saint-Avertin vineyards extend towards the east, stretching almost to the forest of Larçay, on the borders of the Cher, where Paul Louis Courier, the famous vigneron pamphleteer of the Restoration, noted alike for his raillery, wit, and satire, fell beneath the balls of an assassin. A noticeable cru in the neighbourhood of Tours is that of Cinq Mars, the ruined château of which survives as a memorial of the vengeance of Cardinal Richelieu, who, after having sent its owner to the scaffold, commanded its massive walls and towers to be razed '_à hauteur d'infamie_,' as we see them now. Touraine, from its central position, its pleasant air, and its fertile soil, was ever a favourite residence of the earlier French monarchs, and down to the days of the Bourbons the seat of government continually vacillated between the banks of the Seine and those of the Loire. The vintages that ripen along the river have had their day of court favour too; for if Henri of Andelys sneeringly describes the wine of Tours as turning sour, in his famous poem of the _Bataille des Vins_, the sweet white wines of Anjou were greatly esteemed throughout the Middle Ages, and, with those of Orleans, were highly appreciated in Paris down to the seventeenth century. The cult of the 'dive Bouteille' and the fashion of Pantagruelic repasts have always found favour in the fat and fertile 'garden of France;' and the spectacle of citizens, courtiers, and monks staggering fraternally along, 'waggling their heads,' as Rabelais describes them, after a night of it at the tavern, was no uncommon one in the streets of its old historic towns during the period of the Renaissance. [Illustration: TAVERN ROYSTERERS AT EARLY MORNING IN THE TOURAINE.] On proceeding to Vouvray from Tours, we skirt a succession of poplar-fringed meadows, stretching eastward in the direction of Amboise along the right bank of the Loire; and after a time a curve in the river discloses to view a range of vine-clad heights, extending some distance beyond the village of Vouvray. Our route lies past the picturesque ruins of the abbey of Marmoûtier, immortalised in the piquant pages of the _Contes Drôlatiques_, and the Château des Roches--one of the most celebrated castles of the Loire--the numerous excavations in the soft limestone ridge on which they are perched being converted as usual into houses, magazines, and wine-cellars. We proceed through the village of Rochecorbon, and along a road winding among the spurs of the Vouvray range, past hamlets, half of whose inhabitants live in these primitive dwellings hollowed out of the cliff, and finally enter the charming Vallé Coquette, hemmed in on all sides with vine-clad slopes. Here a picturesque old house, half château, half homestead, was pointed out to us as a favourite place of sojourn of Balzac, who held the wine of Vouvray in high esteem, and who speaks of this rocky ridge as 'inhabited by a population of vine-dressers, their houses of several stories being hollowed out in the face of the cliff, and connected by dangerous staircases hewn in the soft stone. Smoke curls from most of the chimneys which peep above the green crest of vines, while the blows of the cooper's hammer resound in several of the cellars. A young girl trips to her garden over the roofs of these primitive dwellings, and an old woman, tranquilly seated on a ledge of projecting rock, supported solely by straggling roots of ivy spreading itself over the disjointed stones, leisurely turns her spinning-wheel, regardless of her dangerous position.' The foregoing picture, sketched by the author of _La Comédie Humaine_ forty years ago, has scarcely changed at the present day. At the point where the village of Vouvray climbs half-way up the vine-crested ridge the rapid-winding Cise throws itself into the Loire, and on crossing the bridge that spans the tributary stream we discern on the western horizon, far beyond the verdant islets studding the swollen Loire, the tall campaniles of Tours Cathedral, which seem to rise out of the water like a couple of Venetian towers. Vouvray is a trim little place, clustered round about with numerous pleasant villas in the midst of charming gardens. The modern château of Moncontour here dominates the slope, and its terraced gardens, with their fantastically-clipped trees and geometric parterres, rise tier above tier up the face of the picturesque height that overlooks the broad fertile valley, with its gardens, cultivated fields, patches of woodland, and wide stretches of green pasture which, fringed with willows and poplars, border the swollen waters of the Loire. Where the river Brenne empties itself into the Cise the Coteau de Vouvray slopes off towards the north, and there rise up the vine-clad heights of Vernou, yielding a similar but inferior wine to that of Vouvray. The village of Vernou is nestled under the hill, and near the porch of its quaint little church a venerable elm-tree is pointed out as having been planted by Sully, Henry IV.'s able Minister. Here, too, an ancient wall, pierced with curious arched windows, and forming part of a modern building, is regarded by popular tradition as belonging to the palace in which Pépin-le-Bref, father of Charlemagne, lived at Vernou. The communes of Dampierre, Souzay, and Parnay, in the neighbourhood of Saumur, produce still red wines rivalling those of Champigny, besides which all the finest white wines are vintaged hereabouts--in the Perrière, the Poilleux, and the Clos Morain vineyards, and in the Rotissans vineyard at Turquant. Wines of very fair quality are also grown on the more favourable slopes extending southwards along the valley of the Thouet, and comprised in the communes of Varrains, Chacé, St. Cyr-en-Bourg, and Brézé. The whole of this district, by the way, abounds with interesting archæological remains. While visiting the vineyards of Varrains and Chacé we came upon a couple of dolmens--vestiges of the ancient Celtic population of the valley of the Loire singularly abundant hereabouts. Brézé, the marquisate of which formerly belonged to Louis XVI.'s famous grand master of the ceremonies--immortalised by the rebuff he received from Mirabeau--boasts a noble château on the site of an ancient fortress, in connection with which there are contemporary excavations in the neighbouring limestone, designed for a garrison of 500 or 600 men. Beyond the vineyards of Saint-Florent, westward of Saumur and on the banks of the Thouet, is an extensive plateau, partially overgrown with vines, where may be traced the remains of a Roman camp. Moreover, in the southern environs of Saumur, in the midst of vineyards producing exclusively white wines, is one of the most remarkable dolmens known. This imposing structure, perfect in all respects save that one of the four enormous stones which roof it in has been split in two, and requires to be supported, is no less than 65 feet in length, 23 feet in width, and 10 feet high. [Illustration: DOLMEN AT BAGNEUX, NEAR SAUMUR.] At Saint-Florent, the pleasant little suburb of Saumur, skirting the river Thouet, and sheltered by steep hills formed of soft limestone, which offers great facilities for the excavation of extensive cellars, the largest manufacturer of Saumur sparkling wines has his establishment. Externally this offers but little to strike the eye. A couple of pleasant country houses, half hidden by spreading foliage, stand at the two extremities of a spacious and well-kept garden, beyond which one catches a glimpse of some outbuildings sheltered by the vine-crowned cliff, in which a labyrinth of gloomy galleries has been hollowed out. Here M. Ackerman-Laurance, the extent of whose business ranks him as second among the sparkling wine manufacturers of the world, stores something like 10,000 casks and several million bottles of wine. At the commencement of the present century, in the days when, as Balzac relates in his _Eugénie Grandet_, the Belgians bought up entire vintages of Saumur wine, then largely in demand with them for sacramental purposes, the founder of the Saint-Florent house commenced to deal in the ordinary still wines of the district. Nearly half a century ago he was led to attempt the manufacture of sparkling wines, but his efforts to bring them into notice failed; and he was on the point of abandoning his enterprise, when an order for one hundred cases revived his hopes, and led to the foundation of the present vast establishment. As already mentioned, for many miles all the heights along the Loire have been more or less excavated for stone for building purposes, so that every one hereabouts who grows wine or deals in it has any amount of cellar accommodation ready to hand. It was the vast extent of the galleries which M. Ackerman _père_ discovered already excavated at Saint-Florent that induced him to settle there in preference to Saumur. Extensive, however, as the original vaults were, considerable additional excavations have from time to time been found necessary; and to-day the firm is still further increasing the area of its cellars, which already comprise three principal avenues, each the third of a mile long, and no fewer than sixty transverse galleries, the total length of which is several miles. One great advantage is that the whole are on the ordinary level. Ranged against the black uneven walls of the more tortuous ancient vaults which give access to these labyrinthine corridors are thousands of casks of wine--some in single rows, others in triple tiers--forming the reserve stock of the establishment. As may be supposed, a powerful vinous odour permeates these vaults, in which the fumes of wine have been accumulating for the best part of a century. After passing beneath a massive stone arch which separates the old cellars from the new, a series of broad and regularly proportioned galleries are reached, having bottles stacked in their tens of thousands on either side. Overhead the roof is perforated at regular intervals with circular shafts, affording both light and ventilation, and enabling the temperature to be regulated to a nicety. In these lateral and transverse galleries millions of bottles of wine in various stages of preparation are stacked. [Illustration: THE CELLARS OF M. ACKERMAN-LAURANCE AT SAINT-FLORENT. LABELLING AND PACKING SPARKLING SAUMUR.] We have explained that in the Champagne it is the custom for the manufacturers of sparkling wine to purchase considerable quantities of grapes from the surrounding growers, and to press these themselves, or have them pressed under their own superintendence. At Saumur only those firms possessing vineyards make their own _vin brut_, the bulk of the wine used for conversion into sparkling wine being purchased from the neighbouring growers. On the newly-expressed must arriving at M. Ackerman-Laurance's cellars it is allowed to rest until the commencement of the ensuing year, when half of it is mixed with wine in stock belonging to last year's vintage, and the remaining half is reserved for mingling with the must of the ensuing vintage. The blending is accomplished in a couple of colossal vats hewn out of the rock, and coated on the inside with cement. Each of these vats is provided with 200 paddles for thoroughly mixing the wine, and with five pipes for drawing it off when the amalgamation is complete. Usually the cuvée will embrace 1600 hogsheads, or 80,000 gallons of wine, almost sufficient for half a million bottles. A fourth of this quantity can be mixed in each vat at a single operation, and this mixing is repeated again and again until the last gallon run off is of precisely the same type as the first. For the finer qualities of sparkling Saumur the proportion of wine from the black grapes to that from white is generally at the rate of three or four to one. For the inferior qualities more wine from white than from black grapes is invariably used. Only in the wine from white grapes is the effervescent principle retained to any particular extent; but, on the other hand, the wine from black grapes imparts both quality and vinous character to the blend. The blending having been satisfactorily accomplished, the wine is stored in casks, never perfectly filled, yet with their bungholes tightly closed, and slowly continues its fermentation, eating up its sugar, purging itself, and letting fall its lees. Three months later it is fined. It is rarely kept in the wood for more than a year, though sometimes the superior qualities remain for a couple of years in cask. Occasionally it is even bottled in the spring following the vintage; still, as a rule, the bottling of sparkling Saumur takes place during the ensuing summer months, when the temperature is at the highest, as this insures to it a greater degree of effervescence. At the time of bottling its saccharine strength is raised to a given degree by the addition of the finest sugar-candy, and henceforward the wine is subjected to precisely the same treatment as is pursued with regard to Champagne. It is in a broad but sombre gallery of the more ancient vaults--the roughly-hewn walls of which are black from the combined action of alcohol and carbonic acid gas--that the processes of disgorging the wine of its sediment, adding the syrup, filling up the bottles with wine to replace that which gushes out when the disgorging operation is performed, together with the re-corking, stringing, and wiring of the bottles, are carried on. The one or two adjacent shafts impart very little light, but a couple of resplendent metal reflectors, which at a distance one might fancy to be some dragon's flaming eyes, combined with the lamps placed near the people at work, effectually illuminate the spot. [Illustration: THE CELLARS OF M. LOUIS DUVAU AÎNÉ AT THE CHÂTEAU OF VARRAINS.] Another considerable manufacturer of sparkling Saumur is M. Louis Duvau aîné, owner of the château of Varrains, in the village of the same name, at no great distance from the Coteau de Saumur. His cellars adjoin the château, a picturesque but somewhat neglected structure of the last century, with sculptured medallions in high relief above the lower windows, and florid vases surmounting the mansards in the roof. In front is a large rambling court shaded with acacia and lime trees, and surrounded by outbuildings, prominent among which is a picturesque dovecot, massive at the base as a martello tower, and having an elegant open stone lantern springing from its bell-shaped roof. The cellars are entered down a steep incline under a low stone arch, the masonry above which is overgrown with ivy in large clusters and straggling creeping plants. We soon come upon a deep recess to the right, wherein stands a unique cumbersome screw-press, needing ten or a dozen men to work the unwieldy capstan which sets the juice flowing from the crushed grapes into the adjacent shallow trough. On our left hand are a couple of ancient reservoirs, formed out of huge blocks of stone, with the entrance to a long vaulted cellar filled with wine in cask. We advance slowly in the uncertain light along a succession of gloomy galleries, with moisture oozing from their blackened walls and roofs, picking our way between bottles of wine stacked in huge square piles and rows of casks raised in tiers. Suddenly a broad flood of light shooting down a lofty shaft throws a Rembrandtish effect across a spacious and most melodramatic-looking cave, roughly hewn out of the rock, and towards which seven dimly-lighted galleries converge. On all sides a scene of bustling animation presents itself. From one gallery men keep arriving with baskets of wine ready for the disgorger; while along another bottles of wine duly dosed with syrup are being borne off to be decorated with metal foil and their distinctive labels. Groups of workmen are busily engaged disgorging, dosing, and re-corking the newly-arrived bottles of wine; corks fly out with a succession of loud reports, suggestive of the irregular fire of a party of skirmishers; a fizzing, spurting, and spluttering of the wine next ensues, and is followed by the incessant clicking of the various apparatus employed in the corking and wiring of the bottles. Gradual inclines conduct to the two lower tiers of galleries, for the cellars of M. Duvau consist of as many as three stories. Down below there is naturally less light, and the temperature, too, is sensibly colder. Advantage is taken of this latter circumstance to remove the newly-bottled wine to these lower vaults whenever an excessive development of carbonic acid threatens the bursting of an undue proportion of bottles, a casualty which among the Saumur sparkling wine manufacturers ranges far higher than with the manufacturers of Champagne. For the economy of time and labour, a lift, raised and lowered by means of a capstan worked by horses, is employed to transfer the bottles of wine from one tier of cellars to another. [Illustration] The demand for sparkling Saumur is evidently on the increase, for M. Duvau, at the time of our visit, was excavating extensive additional cellarage. The subsoil at Varrains being largely composed of marl, which is much softer than the tufa of the Saint-Florent coteau, necessitated the roofs of the new galleries being worked in a particular form in order to avoid having recourse to either brickwork or masonry. Tons of this excavated marl were being spread over the soil of M. Duvau's vineyard in the rear of the château, greatly, it was said, to the benefit of the vines, whose grapes were all of the black variety; indeed, scarcely any wine is vintaged from white grapes in the commune of Varrains. At M. Duvau's we went through a complete scale of sparkling Saumurs, commencing with the younger and less matured samples, and ascending step by step to wines a dozen and more years old. Every year seemed to produce an improvement in the wine, the older varieties gaining greatly in delicacy and softening very perceptibly in flavour. Finding that sparkling wines were being made in most of the wine-producing districts of France, where the growths were sufficiently light and of the requisite quality, Messrs. E. Normandin & Co. conceived the idea of laying the famous Bordeaux district under contribution for a similar purpose, and, aided by a staff of experienced workmen from Epernay, they have succeeded in producing a sparkling Sauternes. Sauternes, as is well known, is one of the finest of white wines, soft, delicate, and of beautiful flavour, and its transformation into a sparkling wine has been very successfully accomplished. Messrs. Normandin's head-quarters are in the thriving little town of Châteauneuf, in the pleasant valley of the Charente, and within fifteen miles of Angoulême, a famous old French town, encompassed by ancient ramparts and crumbling corner-towers; and which, dominated by the lofty belfry of its restored semi-Byzantine cathedral, rising in a series of open arcades, spreads itself picturesquely out along a precipitous height, watered at its base by the rivers Anguienne and Charente. Between Angoulême and Châteauneuf vineyard plots dotted over with walnut-trees, or simple rows of vines divided by strips of ripening maize, and broken up at intervals by bright green pastures, line both banks of the river Charente. The surrounding country is undulating and picturesque. Poplars and elms fringe the roadsides, divide the larger fields and vineyards, and screen the cosy-looking red-roofed farmhouses, which present to the eyes of the passing tourist a succession of pictures of quiet rural prosperity. Châteauneuf communicates with the Sauternes district by rail, so that supplies of wine from there are readily obtainable. Vin de Colombar--a famous white growth which English and Dutch cruisers used to ascend the Charente to obtain cargoes of when the Jerez wines were shut out from England by the Spanish War of Succession--vintaged principally at Montignac-le-Coq, also enters largely into Messrs. Normandin & Co.'s sparkling Sauternes cuvée. This colombar grape is simply the semillon--one of the leading varieties of the Sauternes district--transported to the Charente. The remarkably cool cellars where the firm store their wine, whether in wood or bottle, have been formed from some vast subterranean galleries whence centuries ago stone was quarried, and which are situated about a quarter of an hour's drive from Châteauneuf, in the midst of vineyards and cornfields. The wine is invariably bottled in a cellier at the head establishment, but it is in these cellars where it goes through the course of careful treatment similar to that pursued with regard to Champagne. [Illustration] In order that the delicate flavour of the wine may be preserved, the liqueur is prepared with the finest old Sauternes, without any addition of spirit, and the dose is administered with the most improved modern appliance, constructed of silver, and provided with crystal taps. At the Concours Régional d'Angoulême of 1877, the jury, after recording that they had satisfied themselves by the aid of a chemical analysis that the samples of sparkling Sauternes submitted to their judgment were free from any foreign ingredient, awarded to Messrs. Normandin & Co. the only gold medal given in the Group of Alimentary Products. Encouraged, no doubt, by the success obtained by Messrs. Normandin & Co. with their sparkling Sauternes, the house of Lermat-Robert & Co., of Bordeaux, introduced a few years ago a sparkling Barsac, samples of which were submitted to the jury at the Paris Exhibition of 1878. [Illustration] [Illustration: VINTAGER OF THE CÔTE D'OR.] [Illustration: VINTAGER OF THE JURA.] II. /The Sparkling Wines of Burgundy, the Jura, and the South of France./ Sparkling wines of the Côte d'Or at the Paris Exhibition of 1878--Chambertin, Romanée, and Vougeot--Burgundy wines and vines formerly presents from princes--Vintaging sparkling Burgundies--Their after-treatment in the cellars--Excess of breakage--Similarity of proceeding to that followed in the Champagne--Principal manufacturers of sparkling Burgundies--Sparkling wines of Tonnerre, the birthplace of the Chevalier d'Eon--The Vin d'Arbanne of Bar-sur-Aube--Death there of the Bastard de Bourbon--Madame de la Motte's ostentatious display and arrest there--Sparkling wines of the Beaujolais--The Mont-Brouilly vineyards--Ancient reputation of the wines of the Jura--The Vin Jaune of Arbois beloved of Henri Quatre--Rhymes by him in its honour--Lons-le-Saulnier--Vineyards yielding the sparkling Jura wines--Their vintaging and subsequent treatment--Their high alcoholic strength and general drawbacks--Sparkling wines of Auvergne, Guienne, Dauphiné, and Languedoc--Sparkling Saint-Péray the Champagne of the South--Valence, with its reminiscences of Pius VI. and Napoleon I.--The 'Horns of Crussol' on the banks of the Rhône--Vintage scene at Saint-Péray--The vines and vineyards producing sparkling wine--Manipulation of sparkling Saint-Péray--Its abundance of natural sugar--The cellars of M. de Saint-Prix, and samples of his wines--Sparkling Côte-Rotie, Château-Grillé, and Hermitage--Annual production and principal markets of sparkling Saint-Péray--Clairette de Die--The Porte Rouge of Die Cathedral--How the Die wine is made--The sparkling white and rose-coloured muscatels of Die--Sparkling wines of Vercheny and Lagrasse--Barnave and the royal flight to Varennes--Narbonne formerly a miniature Rome, now noted merely for its wine and honey--Fête of the Black Virgin at Limoux--Preference given to the new wine over the miraculous water--Blanquette of Limoux, and how it is made--Characteristics of this overrated wine. [Illustration] Sparkling wines are made to a considerable extent in Burgundy, notably at Beaune, Nuits, and Dijon; and though as a rule heavier and more potent than the subtile and delicate-flavoured wines of the Marne, still some of the higher qualities, both of the red and white varieties, exhibit a degree of refinement which those familiar only with the commoner kinds can scarcely form an idea of. At the Paris Exhibition of 1878 we tasted, among a large collection of the sparkling wines of the Côte d'Or, samples of Chambertin, Romanée, and Vougeot, of the highest order. Although red wines, they had the merit of being deficient in that body which forms such an objectionable feature in sparkling wines of a deep shade of colour. M. Regnier, the exhibitor of sparkling red Vougeot, sent, moreover, a white sparkling wine, from the species of grape known locally as the clos blanc de Vougeot. These wines, as well as the Chambertin, came from the Côte de Nuits, the growths of which are generally considered of too vigorous a type for successful conversion into sparkling wine, preference being usually given to the produce of the Côte de Beaune. Among the sparkling Burgundies from the last-named district were samples from Savigny, Chassagne, and Meursault, all famous for their fine white wines. Burgundy ranks as one of the oldest viticultural regions of Central Europe, and for centuries its wines have been held in the highest renown. In the Middle Ages both the wines and vines of this favoured province passed as presents from one royal personage to another, just as grand _cordons_ are exchanged between them nowadays. The fabrication of sparkling wine, however, dates no further back than some sixty years or so. The system of procedure is much the same as in the Champagne, and, as there, the wine is mainly the produce of the pineau noir and pineau blanc varieties of grape. At the vintage, in order to avoid bruising the ripened fruit and to guard against premature fermentation, the grapes are conveyed to the pressoirs in baskets, instead of the large oval vats termed _balonges_, common to the district. They are placed beneath the press as soon as possible, and for superior sparkling wines only the juice resulting from the first pressure, and known as the _mère goutte_, or mother drop, is employed. For the ordinary wines, that expressed at the second squeezing of the fruit is mingled with the other. The must is at once run off into casks, which have been previously sulphured, to check, in a measure, the ardour of the first fermentation, and lighten the colour of the newly-made wine. Towards the end of October, when this first fermentation is over, the wine is removed to the cellars, or to some other cool place, and in December it is racked into other casks. In the April following it is again racked, to insure its being perfectly clear at the epoch of bottling in the month of May. The sulphuring of the original casks having had the effect of slightly checking the fermentation and retaining a certain amount of saccharine in the wine, it is only on exceptional occasions that the latter is artificially sweetened previous to being bottled. A fortnight after the tirage the wine commonly attains the stage known as _grand mousseux_, and by the end of September the breakage will have amounted to between 5 and 8 per cent, which necessitates the taking down the stacks of bottles and piling them up anew. The wine as a rule remains in the cellars for fully a couple of years from the time of bottling until it is shipped. Posing the bottles _sur pointe_, agitating them daily, together with the disgorging and liqueuring of the wine, are accomplished precisely as in the Champagne. Among the principal manufacturers of sparkling Burgundies are Messrs. André & Voillot, of Beaune, whose sparkling white Romanée, Nuits, and Volnay are well and favourably known in England; M. Louis Latour, also of Beaune, and equally noted for his sparkling red Volnay, Nuits, and Chambertin, as for his sparkling white varieties; Messrs. Maire et Fils, likewise of Beaune; M. Labouré-Goutard and Messrs. Geisweiller et Fils, of Nuits; Messrs. Marey & Liger-Belair, of Nuits and Vosne; and M. Regnier, of Dijon. In the department of the Yonne--that is, in Lower Burgundy--sparkling wines somewhat alcoholic in character have been made for the last half century at Tonnerre, where the Chevalier d'Eon, that enigma of his epoch, was born. The Tonnerre vineyards are of high antiquity, and for sparkling wines the produce of the black and white pineau and the white morillon varieties of grape is had recourse to. The vintaging is accomplished with great care, and only the juice which flows from the first pressure is employed. This is run off immediately into casks, which are hermetically closed when the fermentation has subsided. The after-treatment of the wine is the same as in the Champagne. Sparkling wines are likewise made at Epineuil, a village in the neighbourhood of Tonnerre, and at Chablis, so famous for its white wines, about ten miles distant. An effervescing wine known as the Vin d'Arbanne is made at Bar-sur-Aube, some fifty miles north-east of Tonnerre, on the borders of Burgundy, but actually in the province of Champagne, although far beyond the limits to which the famed viticultural district extends. It was at Bar-sur-Aube where the Bastard de Bourbon, chief of the sanguinary gang of _écorcheurs_ (flayers), was sewn up in a sack and flung over the parapet of the old stone bridge into the river beneath, by order of Charles VII.; and here, too, Madame de la Motte, of Diamond Necklace notoriety, was married, and in after years made a parade of the ill-gotten wealth she had acquired by successfully fooling that infatuated libertine the Cardinal Prince de Rohan, until her ostentatious display was cut short by her arrest. This Vin d'Arbanne is produced from pineaux and white gamay grapes, which, after being gathered with care at the moment the dew falls, are forthwith pressed. The wine is left on its lees until the following February, when it is racked and fined, the bottling taking place when the moon is at the full in March. Red and white sparkling wines are made to a small extent at Saint-Lager, in the Beaujolais, from wine vintaged in the Mont-Brouilly vineyards, one of the best known of the Beaujolais crus. Mont-Brouilly is a lofty hill near the village of Cercie, and is covered from base to summit on all its sides with vines of the gamay species, rarely trained at all, but left to trail along the ground at their own sweet will. At the vintage, as we witnessed it, men and women--young, middle-aged, and old--accompanied by troops of children, were roaming all over the slopes dexterously nipping off the bunches of grapes with their thumb and finger nails, and flinging them into the little wooden tubs with which they were provided. The pressing of the grapes and the after-treatment of the wine destined to become sparkling are the same in the Beaujolais as in Upper and Lower Burgundy. The red, straw, and yellow wines of the Jura have long had a high reputation in the East of France, and the _Vin Jaune_ of Arbois, an ancient fortified town on the banks of the Cuisance, besieged and sacked in turn by Charles of Amboise, Henri IV., and Louis XIV., was one of the favourite beverages of the tippling Béarnais who styled himself Seigneur of Ay and Gonesse, and who acquired his liking for it while sojourning during the siege of Arbois at the old Château des Arsures. In one of Henri Quatre's letters to his minister Sully we find him observing, 'I send you two bottles of Vin d'Arbois, for I know you do not detest it.' A couple of other bottles of the same wine are said to have cemented the king's reconciliation with Mayenne, the leader of the League; and the lover of La Belle Gabrielle is moreover credited with having composed at his mistress's table some doggrel rhymes in honour of the famous Jura cru: 'Come, little page, serve us aright, The crown is often heavy to bear; So fill up my goblet large and light Whenever you find a vacancy there. This wine is surely no Christian wight, And yet you never complaint will hear That it's not baptised with water clear. Down my throat I pour The old Arbois; And now, my lords, let us our voices raise, And sing of Silenus and Bacchus the praise!' In more modern times the Jura, not content with the fame of the historic yellow wines of Arbois and the deservedly-esteemed straw wines of Château-Châlon, has produced large quantities of sparkling wine, the original manufacture of which commenced as far back as a century ago. To-day the principal seats of the manufacture are at Arbois and Lons-le-Saulnier, the latter town the capital of the department, and one of the most ancient towns of France. Originally founded by the Gauls on the banks of the Vallière, in a little valley bordered by lofty hills, which are to-day covered with vines, it was girded round with fortifications by the Romans. Subsequently the Huns and the Vandals pillaged it; then the French and the Burgundians repeatedly contested its possession, and it was only definitively acquired by France during the reign of Louis XIV. Rouget de l'Isle, the famous author of the 'Marseillaise,' was born at Lons-le-Saulnier, and here also Marshal Ney assembled and harangued his troops before marching to join Napoleon, whom he had promised Louis XVIII. to bring back to Paris in an iron cage. The vineyards whence the principal supplies for these sparkling wines are derived are grouped at varying distances around Lons-le-Saulnier at L'Etoile, Quintigny, Salins, Arbois, St. Laurent-la-Roche, and Pupillin, with the Jura chain of mountains rising up grandly on the east. The best vineyards at L'Etoile--which lies some couple of miles from Lons-le-Saulnier, surrounded by hills, planted from base to summit with vines--are La Vigne Blanche, Montmorin, and Montgenest. At Quintigny, the wines of which are less potent than those of Arbois, and only retain their effervescent properties for a couple of years, the Paridis, Prémelan, and Montmorin vineyards are held in most repute, while at Pupillin, where a soft agreeable wine is vintaged, the principal vineyards are the Faille and the Clos. The vines cultivated for the production of sparkling wines are chiefly the savagnin, or white pineau, the melon of Poligny, and the poulsard, a black variety of grape held locally in much esteem. At the vintage, which commences towards the end of October and lasts until the middle of the following month, all the rotten or unripe grapes are carefully set aside, and the sound ones only submitted to the action of a screw-press. After the must has flowed for about half an hour, the grapes are newly collected under the press and the screw again applied. The produce of this double operation is poured into a vat termed a _sapine_, where it remains until bubbles are seen escaping through the _chapeau_ that forms on the surface of the liquid. The must is then drawn off--sometimes after being fined--into casks, which the majority of wine-growers previously impregnate with the fumes of sulphur. When in cask the wine is treated in one of two ways; either the casks are kept constantly filled to the bunghole, causing the foam which rises to the surface during the fermentation to flow over, and thereby leave the wine comparatively clear, or else the casks are not completely filled, in which case the wine requires to be racked several times before it is in a condition for fining. This latter operation is effected about the commencement of February, and a second fining follows if the first one fails to render the wine perfectly clear. At the bottling, which invariably takes place in April, the Jura wines rarely require any addition of sugar to insure an ample effervescence. Subsequently they are treated in exactly the same manner as the vintages of the Marne are treated by the great Champagne manufacturers. In addition to white sparkling wine, a pink variety, with natural effervescent properties, is made by mixing with the savagnin and melon grapes a certain proportion of the poulsard species, from which the best red wines of the Jura are produced. One of the principal sparkling wine establishments at Lons-le-Saulnier is that of M. Auguste Devaux, founded in the year 1860. He manufactures both sweet and dry wines, which are sold largely in France and elsewhere on the Continent, and have lately been introduced into England. Their alcoholic strength is equivalent to from 25° to 26° of proof spirit, being largely above the dry sparkling wines of the Champagne, which the Jura manufacturers regard as a positive advantage rather than a decided drawback, which it most undoubtedly is. Besides being too spirituous, the sparkling wines of the Jura are deficient in refinement and delicacy. The commoner kinds, indeed, frequently have a pronounced unpleasant flavour, due to the nature of the soil, to careless vinification, or to the inferior quality of liqueur with which the wines have been dosed. Out of some fifty samples of all ages and varieties which in my capacity of juror I tasted at the Paris Exhibition of 1878, I cannot call to mind one that a real connoisseur of sparkling wines would care to admit to his table. Sparkling wines are made after a fashion in several of the southern provinces of France--in Auvergne, at Clermont-Ferrand, under the shadow of the lofty Puy de Dôme; in Guienne, at Astaffort, the scene of a bloody engagement during the Wars of Religion, in which the Protestant army was cut to pieces when about to cross the Garonne; at Nérac, where frail Marguerite de Valois kept her dissolute Court, and Catherine de Médicis brought her flying squadron of fascinating maids-of-honour to gain over the Huguenot leaders to the Catholic cause; and at Cahors, the Divina, or divine fountain of the Celts, and the birthplace of Pope John XXII., of Clement Marot, the early French poet, and of Léon Gambetta; in Dauphiné, at Die, Saint-Chef, Saint-Péray, and Largentière--so named after some abandoned silver mines--and where the vines are cultivated against low walls rising in a series of terraces from the base to the summit of the lofty hills; and in Languedoc, at Brioude, where St. Vincent, the patron saint of the vine-dressers, suffered martyrdom, and where it is the practice to expose the must of the future sparkling wine for several nights to the dew in order to rid it of its reddish colour; also at Linardie, and, more southward still, at Limoux, whence comes the well-known effervescing Blanquette. Principal among the foregoing is the excellent wine of Saint-Péray, commonly characterised as the Champagne of the South of France. The Saint-Péray vineyards border the Rhone some ten miles below the Hermitage coteau--the vines of which are to-day well-nigh destroyed by the phylloxera--but are on the opposite bank of the river. Our visit to Saint-Péray was made from Valence, in which dull southern city we had loitered in order to glance at the vast Hôtel du Gouvernement--where octogenarian Pius VI., after being spirited away a prisoner from Rome and hurried over the Alps in a litter by order of the French Directory, drew his last breath while silently gazing across the rushing river at the view he so much admired--and to discover the house in the Grande Rue, numbered 4, in an attic of which history records that Napoleon I., when a sub-lieutenant of artillery in garrison at Valence, resided, and which he quitted owing three and a half francs to his pastrycook. We crossed the Rhone over one of its hundred flimsy suspension-bridges, on the majority of which a notice warns you neither to smoke nor run, and were soon skirting the base of a lofty, bare, precipitous rock, with the 'horns of Crussol,' as the peasants term two tall pointed gables of a ruined feudal château, perched at the dizzy edge, and having a perpendicular fall of some five or six hundred feet below. The château, which formerly belonged to the Dukes of Uzès, recognised by virtue of the extent of their domains as _premiers pairs de France_, was not originally erected in close proximity to any such formidable precipice. The crag on which it stands had, it seems, been blasted from time to time for the sake of the stone, until on one unlucky occasion, when too heavy a charge of powder was employed, the entire side of the rock, together with a considerable portion of the château itself, were sent flying into the air. The authorities, professing to regard what remained of the edifice as an historical monument of the Middle Ages, hereupon stepped in and prohibited the quarry being worked for the future. [Illustration: CONVEYING GRAPES TO THE PRESS AT SAINT-PÉRAY.] Passing beneath the cliff, one wound round to the left and dived into a picturesque wooded dell at the entrance to a mountain pass, then crossed the rocky bed of a dried-up stream, and drove along an avenue of mulberry-trees, which in a few minutes conducted us to Saint-Péray, where one found the vintage in full operation. Carts laden with tubs filled with white and purple grapes, around which wasps without number swarmed, were arriving from all points of the environs and crowding the narrow streets. Any quantity of grapes were seemingly to be had for the asking, for all the pretty girls in the place were gorging themselves with the luscious-looking fruit. In the coopers' yards brand-new casks were ranged in rows in readiness for the newly-made wine, and through open doorways, and in all manner of dim recesses, one caught sight of sturdy men energetically trampling the gushing grapes under their bare feet, and of huge creaking winepresses reeking with the purple juice. It was chiefly common red wine, of an excellent flavour, however, that was being made in these nooks and corners, the sparkling white wine known as Saint-Péray being manufactured in larger establishments, and on more scientific principles. It is from a white species of grape known as the petite and grosse rousette--the same which yields the white Hermitage--that the Champagne of the south is produced; and the vineyards where they are cultivated occupy all the more favourable slopes immediately outside the village, the most noted being the Coteau-Gaillard, Solignacs, Thioulet, and Hungary. Although there is a close similarity between the manufacture of Champagne and the effervescing wine of Saint-Péray, there are still one or two noteworthy variations. For a wine to be sparkling it is requisite that it should ferment in the bottle, a result obtained by bottling it while it contains a certain undeveloped proportion of alcohol and carbonic acid, represented by so much sugar, of which they are the component parts. This ingredient has frequently to be added to the Champagne wines to render them sparkling, but the wine of Saint-Péray in its natural state contains so much sugar that any addition would be deleterious. This excess of saccharine enables the manufacturer to dispense with some of the operations necessary to the fabrication of Champagne, which, after fermenting in the cask, requires a second fermentation to be provoked in the bottle, whereas the Saint-Péray wine ferments only once, being bottled immediately it comes from the wine-press. The deposit in the wine after being impelled towards the neck of the bottle is got rid of by following the same system as is pursued in the Champagne, but no liqueur whatever is subsequently added to the wine. On the other hand, it is a common practice to reduce the over-sweetness of sparkling Saint-Péray in years when the grapes are more than usually ripe by mixing with it some old dry white wine. At Saint-Péray we visited the cellars of M. de Saint-Prix, one of the principal wine-growers of the district. The samples of effervescing wine which he produced for us to taste were of a pale golden colour, of a slightly nutty flavour, and with a decided suggestion of the spirituous essence known to be concentrated in the wine, one glass of which will go quite as far towards elevating a person as three glasses of Champagne. Keeping the wine for a few years is said materially to improve its quality, to the sacrifice, however, of its effervescing properties. M. de Saint-Prix informed us that he manufactured every year a certain quantity of sparkling Côte-Rotie, Château-Grillé, and Hermitage. The principal markets for the Saint-Péray sparkling wines--the production of which falls considerably short of a million bottles per annum--are England, Germany, Russia, Holland, and Belgium. [Illustration] The other side of the Rhone is fruitful in minor sparkling wines, chief among which is the so-called Clairette de Die, made at the town of that name, a place of some splendour, as existing antiquities show, in the days of the Roman dominion in Gaul. Later on, Die was the scene of constant struggles for supremacy between its counts and bishops, one of the latter being massacred by the populace in front of the cathedral doorway--ever since known by the sinister appellation of the Porte Rouge--and Catholics and Huguenots alike devastated the town in the troublesome times of the Reformation. Clairette de Die is made principally from the blanquette or malvoisie variety of grape, which, after the stalks have been removed, is both trodden with the feet and pressed. The must is run off immediately into casks, and four-and-twenty hours later it is racked into other casks, a similar operation being performed every two or three days for the period of a couple of months, when, the fermentation having subsided, the wine is fined and usually bottled in the following March. Newly-made Clairette de Die is a sweet sparkling wine, but it loses its natural effervescence after a couple of years, unless it has been treated in the same manner as Champagne, which is rarely the case. The wine enjoys a reputation altogether beyond its merits. In addition to the well-known Clairette, some of the wine-growers of Die make sparkling white and rose-coloured muscatels of superior quality, which retain their effervescing properties for several years. A sparkling wine is also made some ten miles from Die, on the road to Saillans, in a district bounded on the one side by the waters of the Drôme, and on the other by strange mountains with helmet-shaped crests. The centre of production is a locality called Vercheny, composed of several hamlets, one of which, named Le Temple, was the original home of the family of Barnave. The impressionable young deputy to the National Assembly formed one of the trio sent to bring back the French royal family from Varennes after their flight from Paris. It will be remembered how, under the influence of Marie Antoinette and Madame Elizabeth, Barnave became transformed during the journey into a faithful partisan of their unhappy cause, and that he eventually paid the penalty of his devotion with his life. In the extreme south of France, and almost under the shadow of the Pyrenees, a sparkling wine of some repute is made at a place called Lagrasse, about five-and-twenty miles westward of Narbonne, the once-famous Mediterranean city, the maritime rival of Marseilles, and in its palmy days, prior to the Christian era, a miniature Rome, with its capitol, its curia, its decemvirs, its consuls, its prætors, its questors, its censors, and its ediles, and which boasted of being the birthplace of three Roman Emperors. To-day Narbonne has to content itself with the humble renown derived from its delicious honey and its characterless full-bodied wines. Limoux, so celebrated for its Blanquette, lies a long way farther to the west, behind the Corbières range of mountains that join on to the Pyrenees, and the jagged peaks, deep barren gorges, and scarred sides of which have been witness of many a desperate struggle during the century and a half when they formed the boundary between France and Spain. We arrived at Limoux just too late for the famous _fête_ of the Black Virgin, which lasts three weeks, and attracts crowds of southern pilgrims to the chapel of Our Lady of Marseilles, perched on a little hill some short distance from the town, with a fountain half-way up, whose water issues drop by drop, and has the credit of possessing unheard-of virtues. The majority of pilgrims, however, exhibit a decided preference for the new-made wine over the miraculous water, and for one-and-twenty days something like a carnival of inebriety prevails at Limoux. Blanquette de Limoux derives its name from the species of grape it is produced from, and which we believe to be identical with the malvoisie, or malmsey. Its long-shaped berries grow in huge bunches, and dry readily on the stalks. The fruit is gathered as tenderly as possible, care being taken that it shall not be in the slightest degree bruised, and is then spread out upon a floor to admit of whatever sugar it contains becoming perfect. The bad grapes having been carefully picked out, and the seeds extracted from the remaining fruit, the latter is now trodden, and the must, after being filtered through a strainer, is placed in casks, where it remains fermenting for about a week, during which time any overflow is daily replenished by other must reserved for the purpose. The wine is again clarified, and placed in fresh casks with the bungholes only lightly closed until all sensible fermentation has ceased, when they are securely fastened up. The bottling takes place in the month of March, and the wine is subsequently treated much after the same fashion as sparkling Saint-Péray, excepting that it is generally found necessary to repeat the operation of _dégorgement_ three, if not as many as four, times. Blanquette de Limoux is a pale white wine, the saccharine properties of which have become completely transformed into carbonic acid gas and alcohol. It is consequently both dry and spirituous, deficient in delicacy, and altogether proves a great disappointment. At its best it may, perhaps, rank with sparkling Saint-Péray, but unquestionably not with an average Champagne. [Illustration: PREPARING THE CHAMPAGNE LIQUEUR.] III. /Facts and Notes respecting Sparkling Wines./ Dry and sweet Champagnes--Their sparkling properties--Form of Champagne glasses--Style of sparkling wines consumed in different countries--The colour and alcoholic strength of Champagne--Champagne approved of by the faculty--Its use in nervous derangements--The icing of Champagne--Scarcity of grand vintages in the Champagne--The quality of the wine has little influence on the price--Prices realised by the Ay and Verzenay crus in grand years--Suggestions for laying down Champagnes of grand vintages--The improvement they develop after a few years--The wine of 1874--The proper kind of cellar in which to lay down Champagne--Advantages of Burrow's patent slider wine-bins--Increase in the consumption of Champagne--Tabular statement of stocks, exports, and home consumption from 1844-5 to 1877-8--When to serve Champagne at a dinner-party--Charles Dickens's dictum that its proper place is at a ball--Advantageous effect of Champagne at an ordinary British dinner-party. [Illustration] In selecting a sparkling wine, one fact should be borne in mind--that just as, according to Sam Weller, it is the seasoning which makes the pie mutton, beef, or veal, so it is the liqueur which renders the wine dry or sweet, light or strong. A really palatable dry Champagne, emitting the fragrant bouquet which distinguishes all wines of fine quality, free from added spirit, is obliged to be made of the very best _vin brut_, to which necessarily an exceedingly small percentage of liqueur will be added. On the other hand, a sweet Champagne can be produced from the most ordinary raw wine--the Yankees even claim to have evolved it from petroleum--as the amount of liqueur it receives completely masks its original character and flavour. This excess of syrup, it should be remarked, contributes materially to the wine's explosive force and temporary effervescence; but shortly after the bottle has been uncorked the wine becomes disagreeably flat. A fine dry wine, indebted as it is for its sparkling properties to the natural sweetness of the grape, does not exhibit the same sudden turbulent effervescence. It continues to sparkle, however, for a long time after being poured into the glass, owing to the carbonic acid having been absorbed by the wine itself instead of being accumulated in the vacant space between the liquid and the cork, as is the case with wines that have been highly liqueured. Even when its carbonic acid gas is exhausted, a good Champagne will preserve its fine flavour, which the effervescence will have assisted to conceal. Champagne, it should be noted, sparkles best in tall tapering glasses; still these have their disadvantages, promoting, as they do, an excess of froth when the wine is poured into them, and almost preventing any bouquet which the wine possesses from being recognised. Manufacturers of Champagne and other sparkling wines prepare them dry or sweet, light or strong, according to the markets for which they are designed. The sweet wines go to Russia and Germany--the sweet-toothed Muscovite regarding M. Louis Roederer's syrupy product as the _beau-idéal_ of Champagne, and the Germans demanding wines with twenty or more per cent of liqueur, or nearly quadruple the quantity that is contained in the average Champagnes shipped to England. France consumes light and moderately sweet wines; the United States gives a preference to the intermediate qualities; China, India, and other hot countries stipulate for light dry wines; while the very strong ones go to Australia, the Cape, and other places where gold and diamonds and suchlike trifles are from time to time 'prospected.' Not merely the driest, but the very best, wines of the best manufacturers, and commanding of course the highest prices, are invariably reserved for the English market. Foreigners cannot understand the marked preference shown in England for exceedingly dry sparkling wines. They do not consider that as a rule they are drunk during dinner with the _plats_, and not at dessert, with all kinds of sweets, fruits, and ices, as is almost invariably the case abroad. Good Champagne is usually of a pale straw colour, but with nothing of a yellow tinge about it. When its tint is pinkish, this is owing to a portion of the colouring matter having been extracted from the skins of the grapes--a contingency which every pains are taken to avoid, although, since the success achieved by the wine of 1874, slightly pink wines are likely to be the fashion. The positive pink or rose-coloured Champagnes, such as were in fashion some thirty years ago, are simply tinted with a small quantity of deep-red wine. The alcoholic strength of the drier wines ranges from eighteen degrees of proof spirit upwards, or slightly above the ordinary Bordeaux, and under all the better-class Rhine wines. Champagnes, when loaded with a highly alcoholised liqueur, will, however, at times mark as many as thirty degrees of proof spirit. The lighter and drier the sparkling wine, the more wholesome it is, the saccharine element in conjunction with alcohol being not only difficult of digestion, but generally detrimental to health. The faculty are agreed that fine dry Champagnes, consumed in moderation, are among the safest wines that can be partaken of. Any intoxicating effects are rapid but exceedingly transient, and arise from the alcohol suspended in the carbonic acid being applied rapidly and extensively to the surface of the stomach. 'Champagne,' said Curran, 'simply gives a runaway rap at a man's head.' Dr. Druitt, equally distinguished by his studies upon wine and his standing as a physician, pronounces good Champagne to be 'a true stimulant to body and mind alike--rapid, volatile, transitory, and harmless. Amongst the maladies that are benefited by it,' remarks he, 'is the true neuralgia--intermitting fits of excruciating pain running along certain nerves, without inflammation of the affected part, often a consequence of malaria, or of some other low and exhausting causes. To enumerate the cases in which Champagne is of service would be to give a whole nosology. Who does not know the misery, the helplessness of that abominable ailment influenza, whether a severe cold or the genuine epidemic? Let the faculty dispute about the best remedy if they please; but a sensible man with a bottle of Champagne will beat them all. Moreover, whenever there is pain, with exhaustion and lowness, then Dr. Champagne should be had up. There is something excitant in the wine--doubly so in the sparkling wine, which, the moment it touches the lips, sends an electric telegram of comfort to every remote nerve. Nothing comforts and rests the stomach better, or is a greater antidote to nausea.' Champagne of fine quality should never be mixed with ice or iced water; neither should it be iced to the extent Champagnes ordinarily are; for, in the first place, the natural lightness of the wine is such as not to admit of its being diluted without utterly spoiling it, and in the next, excessive cold destroys alike the fragrant bouquet of the wine and its delicate vinous flavour. Really good Champagne should not be iced below a temperature of fifty degrees Fahr.; whereas exceedingly sweet wines will bear icing down almost to freezing point, and be rendered more palatable by the process. The above remarks apply to all sorts of sparkling wine. In the Champagne, what may be termed a really grand vintage commonly occurs only once, and never more than twice, in ten years. During the same period, however, there will generally be one or two other tolerably good vintages. In grand years the crop, besides being of superior quality, is usually abundant, and as a consequence the price of the raw wine is scarcely higher than usual. Apparently from this circumstance the sparkling wine of grand vintages does not command an enhanced value, as is the case with other fine wines. It is only when speculators recklessly outbid each other for the grapes or the _vin brut_, or when stocks are low and the _vin brut_ is really scarce, that the price of Champagne appears to rise. That superior quality does not involve enhanced price is proved by the amounts paid for the Ay and Verzenay crus in years of grand vintages. During the present century these appear to have been 1802, '06, '11, '18, '22, '25, '34, '42, '46, '57, '65, '68, and '74--that is, thirteen grand vintages in eighty years. Other good vintages, although not equal to the foregoing, occurred in the years 1815, '32, '39, '52, '54, '58, '62, '64, and '70. Confining ourselves to the grand years, we find that the Ay wine of 1834, owing to the crop being plentiful as well as good, only realised from 110 to 140 francs the pièce of 44 gallons, although for two years previously this had fetched them 150 to 200 francs. In 1842 the price ranged from 120 to 150 francs, whereas the vastly inferior wine of the year before had commanded from 210 to 275 francs. In 1846, the crop being a small one, the price of the wine rose, and in 1857 the pièce fetched as much as from 480 to 500 francs; still this was merely a trifle higher than it had realised the two preceding years. In 1865 the price was 380 to 400 francs, and in 1868 about the same, whereas the indifferent vintages of 1871, '72, and '73--the latter eventually proved to be of execrable quality--realised from 500 to 1000 francs the pièce. It was very similar with the wine of Verzenay. In 1834 the price of the pièce ranged from 280 to 325 francs, or about the average of the three preceding years. In 1846, the crop being scarce, the price rose considerably; while in 1857, when the crop was plentiful, it fell to 500 francs, or from 5 to 20 per cent below that of the two previous years, when the yield was both inferior and less abundant. In 1865 the price rose 33 per cent above that of the year before; still, although Verzenay wine of 1865 and 1868 fetched from 420 to 450 francs the pièce, and that of 1874 as much as 900 francs, the greatly inferior vintages of 1872-73 commanded 900 and 1030 francs the pièce. Subsequently the price of the wine fell to 350 and 450 francs the pièce, to rise again, however, in 1878 to 900 francs, which was followed by a fall the following year to 250 francs. In 1880, when the yield was no more than the quarter of an average one, and the quality was as yet undetermined, the Ay and Verzenay wines commanded the high price of 1500 francs and upwards the pièce. Exceptionally high prices were also realised for the wines of the neighbouring localities. Consumers of Champagne, if wise, would profit by the circumstance that quality has not the effect of causing a rise in prices, and if they were bent upon drinking their favourite wine in perfection, as one meets with it at the dinner-tables of the principal manufacturers, who only put old wine of grand vintages before their guests, they would lay down Champagnes of good years in the same way as the choicer vintages of port, burgundy, and bordeaux are laid down. The Champagne of 1874 was a wine of this description, with all its finer vinous qualities well developed, and consequently needing age to attain not merely the roundness, but the refinement, of flavour pertaining to a high-class sparkling wine. Instead of being drunk a few months after it was shipped in the spring and summer of 1877, as was the fate of much of the wine in question, it needed being kept for three years at the very least to become even moderately round and perfect. In the Champagne one had many opportunities of tasting the grander vintages that had arrived at ten, twelve, or fifteen years of age, and had thereby attained supreme excellence. It is true their effervescence had moderated materially, but their bouquet and flavour were perfect, and their softness and delicacy something marvellous. A great wine like that of 1874 will go on improving for ten years, providing it is only laid down under proper conditions. These are, first, an exceedingly cool but perfectly dry cellar, the temperature of which should be as low as from 50° to 55° Fahr., or even lower if this is practicable. The cellar, too, should be neither over dark nor light, scrupulously clean, and sufficiently well ventilated for the air to be continuously pure. It is requisite that the bottles should rest on their sides, to prevent the corks shrinking, and thus allowing both the carbonic acid and the wine itself to escape. For laying down Champagne or any kind of sparkling wine, an iron wine-bin is by far the best; and the patent 'slider' bins made by Messrs. W. & J. Burrow, of Malvern, are better adapted to the purpose than any other. In these the bottles rest on horizontal parallel bars of wrought-iron, securely riveted into strong wrought-iron uprights, both at the back and in front. They are especially adapted for laying down Champagne, as they admit of the air circulating freely around the bottles, thus conducing to the preservation of the metal foil round their necks, and keeping the temperature of the wine both cool and equable. From the subjoined table it will be seen that the consumption of Champagne has more than quadrupled since the year 1844-5, a period of six-and-thirty years. A curious fact to note is the immense increase in the exports of the wine during the three years following the Franco-German war, during which contest both the exports and home consumption of Champagne naturally fell off very considerably. No reliable information is available as to the actual quantity of Champagne consumed yearly in England, but this may be taken in round numbers at about four millions of bottles. The consumption of the wine in the United States varies from rather more than a million and a half to nearly two million bottles annually. OFFICIAL RETURN BY THE CHAMBER OF COMMERCE AT REIMS OF THE TRADE IN CHAMPAGNE WINES FROM APRIL 1844 TO APRIL 1881. +-----------+--------------+------------+-------------+-------------+ |Years--from| | Number of | Number of | Total | | April |Manufacturers'| Bottles |Bottles sold | Number of | | to April. | Stocks. | exported. | in France. |Bottles sold.| +-----------+--------------+------------+-------------+-------------+ | 1844-45 | 23,285,218 | 4,380,214 | 2,255,438 | 6,635,652 | | 1845-46 | 22,847,971 | 4,505,308 | 2,510,605 | 7,015,913 | | 1846-47 | 18,815,367 | 4,711,915 | 2,355,366 | 7,067,281 | | 1847-48 | 23,122,994 | 4,859,625 | 2,092,571 | 6,952,196 | | 1848-49 | 21,290,185 | 5,686,484 | 1,473,966 | 7,160,450 | | 1849-50 | 20,499,192 | 5,001,044 | 1,705,735 | 6,706,779 | | 1850-51 | 20,444,915 | 5,866,971 | 2,122,569 | 7,989,540 | | 1851-52 | 21,905,479 | 5,957,552 | 2,162,880 | 8,120,432 | | 1852-53 | 19,376,967 | 6,355,574 | 2,385,217 | 8,740,790 | | 1853-54 | 17,757,769 | 7,878,320 | 2,528,719 | 10,407,039 | | 1854-55 | 20,922,959 | 5,895,773 | 2,452,743 | 9,348,516 | | 1855-56 | 15,957,141 | 7,137,001 | 2,562,039 | 9,699,040 | | 1856-57 | 15,228,294 | 8,490,198 | 2,468,818 | 10,959,016 | | 1857-58 | 21,628,778 | 7,368,310 | 2,421,454 | 9,789,764 | | 1858-59 | 28,328,251 | 7,666,633 | 2,805,416 | 10,472,049 | | 1859-60 | 35,648,124 | 8,265,395 | 3,039,621 | 11,305,016 | | 1860-61 | 30,235,260 | 8,488,223 | 2,697,508 | 11,185,731 | | 1861-62 | 30,254,291 | 6,904,915 | 2,592,875 | 9,497,790 | | 1862-63 | 28,013,189 | 7,937,836 | 2,767,371 | 10,705,207 | | 1863-64 | 28,466,975 | 9,851,138 | 2,934,996 | 12,786,134 | | 1864-65 | 33,298,672 | 9,101,441 | 2,801,626 | 11,903,067 | | 1865-66 | 34,175,429 | 10,413,455 | 2,782,777 | 13,196,132 | | 1866-67 | 37,608,716 | 10,283,886 | 3,218,343 | 13,502,229 | | 1867-68 | 37,969,219 | 10,876,585 | 2,924,268 | 13,800,853 | | 1868-69 | 32,490,881 | 12,810,194 | 3,104,496 | 15,914,690 | | 1869-70 | 39,272,562 | 13,858,839 | 3,628,461 | 17,487,300 | | 1870-71 | 39,984,003 | 7,544,323 | 1,633,941 | 9,178,264 | | 1871-72 | 40,099,243 | 17,001,124 | 3,367,537 | 20,368,661 | | 1872-73 | 45,329,490 | 18,917,779 | 3,464,059 | 22,381,838 | | 1873-74 | 46,573,974 | 18,106,310 | 2,491,759 | 20,598,069 | | 1874-75 | 52,733,674 | 15,318,345 | 3,517,182 | 18,835,527 | | 1875-76 | 64,658,767 | 16,705,719 | 2,439,762 | 19,145,481 | | 1876-77 | 71,398,726 | 15,882,964 | 3,127,991 | 19,010,955 | | 1877-78 | 70,183,863 | 15,711,651 | 2,450,983 | 18,162,634 | | 1878-79 | 65,813,194 | 14,844,181 | 2,596,356 | 17,440,537 | | 1879-80 | 68,540,668 | 16,524,593 | 2,665,561 | 19,190,154 | | 1880-81 | 54,505,964 | 18,220,980 | 2,330,924 | 20,551,904 | +-----------+--------------+------------+-------------+-------------+ Distinguished gourmets are scarcely agreed as to the proper moment when Champagne should be introduced at the dinner-table. Dyspeptic Mr. Walker, of 'The Original,' laid it down that Champagne ought to be introduced very early at the banquet, without any regard whatever to the viands it may chance to accompany. 'Give Champagne,' he says, 'at the beginning of dinner, as its exhilarating qualities serve to start the guests, after which they will seldom flag. No other wine produces an equal effect in increasing the success of a party--it invariably turns the balance to the favourable side. When Champagne goes rightly, nothing can well go wrong.' These precepts are sound enough; still all dinner-parties are not necessarily glacial, and the guests are not invariably mutes. Before Champagne can be properly introduced at a formal dinner, the conventional glass of sherry or madeira should supplement the soup, a white French or a Rhine wine accompany the fish, and a single glass of bordeaux prepare the way with the first _entrée_ for the sparkling wine, which, for the first round or two, should be served briskly and liberally. A wine introduced thus early at the repast should of course be dry, or, at any rate, moderately so. We certainly do not approve of Mr. Charles Dickens's dictum that Champagne's proper place is not at the dinner-table, but solely at a ball. 'A cavalier,' he said, 'may appropriately offer at propitious intervals a glass now and then to his danceress. There it takes its fitting rank and position amongst feathers, gauzes, lace, embroidery, ribbons, white-satin shoes, and eau-de-Cologne, for Champagne is simply one of the elegant extras of life.' This is all very well; still the advantageous effect of sparkling wine at an ordinary British dinner-party, composed as it frequently is of people brought indiscriminately together in accordance with the exigencies of the hostess's visiting-list, cannot be gainsaid. After the preliminary glowering at each other, _more Britannico_, in the drawing-room, everybody regards it as a relief to be summoned to the repast, which, however, commences as chillily as the soup and as stolidly as the salmon. The soul of the hostess is heavy with the anxiety of prospective dishes, the brow of the host is clouded with the reflection that our rulers are bent upon adding an extra penny to the income-tax. Placed between a young lady just out and a dowager of grimly Gorgonesque aspect, you hesitate how to open a conversation. Your first attempts are singularly ineffectual, only eliciting a dropping fire of monosyllables. You envy the placidly languid young gentleman opposite, limp as his fast-fading camellia, and seated next to Belle Breloques, who is certain, in racing parlance, to make the running for him. But even that damsel seems preoccupied with her fan, and, despite her _aplomb_, hesitates to break the icy silence. The two City friends of the host are lost in mute speculation as to the future price of indigo or Ionian Bank shares, while their wives seem to be mentally summarising the exact cost of each other's toilettes. Their daughters, or somebody else's daughters, are desperately jerking out monosyllabic responses to feeble remarks concerning the weather, the theatres, operatic _débutantes_, the people in the Row, æstheticism, and kindred topics from a couple of F.O. men. Little Snapshot, the wit, on the other side of the Gorgon, has tried to lead up to a story, but has found himself, as it were, frozen in the bud. When lo! the butler softly sibillates in your ear the magic word 'Champagne,' and as it flows, creaming and frothing, into your glass, a change comes over the spirit of your vision. The hostess brightens, the host coruscates. The young lady on your right suddenly develops into a charming girl, with becoming appreciation of your pet topics and an astounding aptness for repartee. The Gorgon thaws, and implores Mr. Snapshot, whose jests are popping as briskly as the corks, not to be so dreadfully funny, or he will positively kill her. Belle Breloques can always talk, and now her tongue rattles faster then ever, till the languid one arouses himself like a giant refreshed, and gives her as good as he gets. The City men expatiate in cabalistic language on the merits of some mysterious speculation, the prospective returns from which increase with each fresh bottle. One of their wives is discussing church decoration with a hitherto silent curate, and the other is jabbering botany to a red-faced warrior. The juniors are in full swing, and ripples of silvery laughter rise in accompaniment to the beaded bubbles all round the table. Gradually, as people drift off from generalities to their own particular line--gastronomy, politics, art, sport, fashion, literature, church matters, theatricals, speculation, scandal, dress, and the like--the scraps of sentences that the ear catches flying about the table present a mosaic somewhat resembling the following: 'Forster should have sent him to Kilmainham--to see that dear delightful Mr. Irving in--ten-inch armour-plating, but could not steer in a sea-way, so--sat down in the saddle and rammed his spurs into--Petsy Prettitoes and half a dozen girls from the Cruralia, who were--ordained last week by the Bishop of London, when his lordship--said there was no doubt who best deserved the vacant Garter, and declared--a dividend of seven per cent for the--comet year with a bouquet--of sunflowers and lilies on satin, which you should--cover with a light crust--of stiff clay, with a rasper on the further side as--the third story of the hotel overlooking--the Euphrates Valley Railway, which would lead to--the loveliest bit of landscape in the Academy--with the finest hair in the world, and eyes like--a boiled cod's head and shoulders--cut low at the neck, with a gold shoulder-strap, and--nothing else to speak of before the House except the Bill for--her photographs, which are in all the shop-windows, beside Mrs. Langtry's--who never ought to have allowed Bismarck to--assist at the consecration of--the Henley course--so the Duke started at once for Aldershot, and reviewed--the two best novels of the season--cut up with tomatoes and a dash of garlic--and was positive he saw them dining together at Richmond on--fourteen brace of birds and five hares in--the loveliest set of embroidered vestments and an altar-cloth worked for--a Conservative majority, which will drive the Government to--take a couple of stalls at Her Majesty's to hear _Carmen_--who gave him the last galop, but he--blundered at his first fence and fell--to seventy-two and a half, whilst the preference shares were--all ordered on foreign service and--heard nothing from the Irish members but--Oscar Wilde's poems bound in red morocco--with a white-satin train and--plenty of body and a good colour--all through riding every morning in--a private box on the upper tier--and that is why Gladstone at once gave orders--for them to be actually shut up together--in the strong room of the Bank of England, with a reserve fund of bullion--from the music in the first act of _Patience_--equal to that of Job when he said--well, only half a glass, then, since you are so pressing.' And all this is due to Champagne, that great unloosener not merely of tongues, but, better still, of purse-strings, as is well known to the secretaries of those charitable institutions which set the exhilarating wine flowing earliest at their anniversary dinners. [Illustration] [Illustration] APPENDIX. THE PRINCIPAL CHAMPAGNE AND OTHER FRENCH SPARKLING WINE BRANDS. [asterism] In this list, whenever a manufacturer has various qualities, the higher qualities are always placed first. The lowest qualities are omitted altogether. CHAMPAGNES. Firms and Wholesale Brands. Qualities. On side of Corks. Agents. AYALA & Co., [Illustration] Extra (Dry) Extra. /Ay/ First (Dry) Première. Ayala & Co., 59 & [Illustration] Second. 60 Great Tower-street, London Runk & Unger, 50 Park-place, New York BINET FILS & Co., [Illustration] Dry Elite Dry Elite. /Reims/ First First quality. Rutherford & Browne, 5 Water-lane, London BOLLINGER, J., [Illustration] Very Dry Extra Very Dry Extra /Ay/ quality. L. Mentzendorf, 6 Dry Extra Dry Extra Idol-lane, quality. London E. & J. Burke, 40 Beaver-street, New York BRUCH-FOUCHER & Co., [Illustration] Carte d'Or. /Mareuil/ First. L. Ehrmann, 34 Great Second. Tower-street, London CLICQUOT-PONSARDIN, [Illustration] Dry England. /Vve., Reims/ Rich " (WERLE & Co.) Fenwick, Parrot, & Co., 124 Fenchurch-street, London Schmidt Bros., New York DE CAZANOVE, C., [Illustration] Vin Monarque Extra. /Avise/ First. J. R. Hunter & Co., Second. 46 Fenchurch-street, London DEUTZ & GELDERMANN, [Illustration] Gold Lack Gold Lack. /Ay/ (Extra Dry J. R. Parkington & and Dry) Co., Crutched Cabinet (Extra Cabinet. Friars, London Dry and Dry) DUCHATEL-OHAUS, [Illustration] Carte Blanche /Reims/ (Dry and Woellworth & Co., Rich). 70 Mark-lane, Verzenay (do.). London Sillery (do.). DUMINY & Co., [Illustration] Extra Maison fondée en /Ay/ 1814. Fickus, Courtenay, & [Illustration] First " Co., St. Dunstan's-buildings, St. Dunstan's-hill, London Anthony Oechs, 51 Warren-street, New York ERNEST IRROY, [Illustration] Carte d'Or, Carte d'Or, Sec. /Reims/ Dry Cuddeford & Smith, Carte d'Or Carte d'Or. 66 Mark-lane, London F. O. de Luze & Co., 18 South William-street, New York FARRE, CHARLES, [Illustration] Cabinet (Grand Cabinet (Grand /Reims/. Vin) Vin). Hornblower & Co., [Illustration] Carte Blanche Carte Blanche. 50 Mark-lane, Carte Noire Carte Noire. London Gilmor & Gibson, Baltimore Mel & Sons, San Francisco Hogg, Robinson, & Co., Melbourne FISSE, THIRION, & [Illustration] Cachet d'Or Cachet d'Or. Co., /Reims/ (Extra Dry Stallard & Smith, and Medium 25 Philpot-lane, Dry) London Carte Blanche Carte Blanche. (Dry, Medium Dry, and Rich) Carte Noire Carte Noire. (Dry and Medium Dry) GÉ-DUFAUT & Co., [Illustration] Vin de Réserve. /Pierry/ Vin de Cabinet. L. Rosenheim & Sons, Bouzy, 1^{er} 7 Union-court, Cru. Old Broad-street, Fleur de London Sillery. GIBERT, GUSTAVE, [Illustration] Vin du Roi /Reims/ (Extra Dry, Cock, Russell, & Co., Dry, or 23 Rood-lane, Rich). London Hays & Co., 40 [Illustration] Extra (Extra Day-street, Dry, Dry, New York or Rich). GIESLER & Co., [Illustration] Extra Extra. /Avize/ Superior F. Giesler & Co., India India. 32 Fenchurch-street, First. London Purdy & Nicholas, [Illustration] 43 Beaver-street Second. New York HEIDSIECK & Co., [Illustration] Dry Monopole. /Reims/. Monopole (Rich). Theodor Satow & Co., Dry Vin 141 Fenchurch-street, Royal. London Grand Vin Schmidt & Peters, Royal (Rich). 20 Beaver-street, New York KRUG & Co., [Illustration] Carte Carte Blanche, /Reims/ Blanche England. Inglis & Cunningham, Private Private Cuvée, 60 Mark-lane, Cuvée England. London A. Rocherau & Co., New York MAX. SUTAINE & Co., [Illustration] Creaming Sillery /Reims/ (Extra Dry). (VEUVE MORELLE & Co.) H. Schultz, 71 Great Creaming Sillery. Tower-st., London Knoepfel & Co., 60 Bouzy (Dry). Liberty-street, Sparkling Sillery. New York MOËT & CHANDON, [Illustration] Brut Imperial, England. /Epernay/ Impérial Simon & Dale, Creaming Creaming, " Old Trinity House, 5 Water-lane, Extra Extra London, Agents for Superior Superior, " Gt. Britain and Extra Dry White Dry, " the Colonies Sillery Renauld, François, White Dry " " , " & Co., 23 Sillery Beaver-street, First England. New York J. Hope & Co., [Illustration] Second. Montreal MONTEBELLO, DUC DE, [Illustration] Cuvée Extra Cuvée Extra. /Mareuil/ Carte Reserve. John Hopkins & Co., Blanche 26 Crutched Friars, London Coyle & Turner, 31 Lower Ormond Quay, Dublin MUMM (G. H.) & Co., [Illustration] Vin Brut /Reims/ Extra. W. J. & T. Welch, Carte Carte Blanche. 10 Corn Exchange Blanche Chambers, Extra Dry Extra Dry. Seething-lane, Extra Extra Quality. London F. de Bary & Co., 41 Warren-street, New York MUMM, JULES, & Co., [Illustration] Extra Dry. /Reims/ Dry. J. Mumm & Co., 3 Mark-lane, London PÉRINET & FILS, [Illustration] Cuvée Réservée Cuvée /Reims/ (Extra Dry) Réservée. J. Barnett & Son, White Dry White Dry 36 Mark-lane, Sillery Sillery. London Wood, Pollard, & Co., Boston, U.S. Hooper & Donaldson, San Francisco PERRIER-JOUËT & Co., [Illustration] Cuvée de Réserve Extra. /Epernay/. Pale Dry A. Boursot & Co., Creaming. 9 Hart-st., First. Crutched Friars, London PFUNGST FRÈRES [Illustration] Carte d'Or Carte d'Or. & Cie., /Ay/, (Dry, Extra /Epernay/ Dry, & Brut). J. L. Pfungst & Co., Sillery Crêmant Sillery 23 Crutched (Extra Dry and Crêmant Friars, London Brut) Carte Noire Carte Noire. (Dry, Extra Dry, and Brut) Cordon Blanc Cordon Blanc. (Full, Dry, & Extra Dry) PIPER (H.) & Co., [Illustration] Très-Sec Kunkelmann /Reims/ (Extra Dry) & Co. (KUNKELMANN & Co.) Sec (Very " " Newton & Rivière, Dry) 33 Great Carte Blanche " " Tower-street, (Rich) London John Osborn, Son, & Co., New York POL ROGER & Co., [Illustration] Vin Réservé. /Epernay/ Reuss, Lauteren & Co., 39 Crutched Friars, London POMMERY, VEUVE, [Illustration] Extra Sec Veuve Pommery. /Reims/ (Vin Brut) (POMMERY & GRENO) A. Hubinet, 24 Mark-lane, London Charles Graef, [Illustration] Sec. 65 Broad-street, New York ROEDERER, LOUIS, [Illustration] Carte Blanche Reims, Carte /Reims/ Blanche, Gt. Grainger & Son, 108 Britain. Fenchurch-street, London ROEDERER, THÉOPHILE, [Illustration] Crystal Special & Co. (Maison Champagne, Cuvée. fondée en 1864), Special Cuvée /Reims/ Extra Reserve Reserve Cuvée. J. Ashburner, Cuvée Biart, & Co., 150 Carte Blanche, Carte Blanche. Fenchurch-street, Ex. London Carte Noire, Carte Noire. First Verzenay Verzenay. ROPER FRÈRES & Co., [Illustration] Vin Brut, Vin Brut. /Rilly-la-Montagne/ or Natural 24 Crutched Champagne Friars, London First (Extra Dry) Extra Dry. Do. (Medium Dry) Medium Dry. Second. Crême de Bouzy. RUINART, PÈRE [Illustration] Carte Anglaise. ET FILS, Dry Pale Crêmant. /Reims/ Ex. Dry Ruinart, Père Sparkling. et Fils, 22 St. Carte Blanche, Swithin's-lane, First. London DE SAINT-MARCEAUX [Illustration] Vin Brut Vin Brut. & Co., /Reims/ Carte d'Or Very Dry. (C. ARNOULD (Extra Dry) & HEIDELBERGER) Bouzy Nonpareil Vin Sec. Groves & Co., (Dry) 5 Mark-lane, Carte Blanche London (Medium). Hermann Bätjer & _For America Bro., only_. New York [Illustration] Dry Royal Dry. Extra Dry Extra Dry. Second (Medium) SAUMUR AND SAUTERNES. _Firms and Wholesale _Brands._ _Qualities._ _On side of Corks._ Agents._ ACKERMAN-LAURANCE, [Illustration] Carte d'Or Carte d'Or. /St. Florent, Carte Rose Carte Rose. Saumur/ Carte Bleue Carte Bleue. J. N. Bishop, Carte Noire Carte Noire. 41 Crutched Friars, London D. McDougall jun. & Co., St. George's-place, Glasgow DUVAU, LOUIS, [Illustration] Carte d'Or, /Aîné, Château Ex. Sup. de Varrains,/ Carte d'Argent, near /Saumur/ Ex. Jolivet & Canney, Carte Blanche, 3 Idol-lane, Sup. London Carte Rose, Ord. LORRAIN, JULES, [Illustration] Carte d'Or. /Château Carte Blanche. de la Côte, Carte Rose. Varrains/, Carte Bleue. near /Saumur/ J. Lorrain, 73 Great Tower-st., London ROUSTEAUX, A., [Illustration] Extra. /St. Florent, Saumur/ Cock, Russell, & Co., 63 Great Tower-street, London I. H. Smith's Sons, [Illustration] First. Peck Slip, New York NORMANDIN (E.) [Illustration] Sparkling Sauternes & Co., (Extra Dry and Dry). /Châteauneuf-sur-Charente/ P. A. Maignen, 22 Great Tower-street, London BURGUNDIES. _Firms and Wholesale _Brands._ _Qualities._ _On side of Corks._ Agents._ ANDRÉ & VOILLOT, [Illustration] Romanée (White). /Beaune/ Nuits (do.). Cock, Russell, Volnay (do.). & Co., Saint-Péray. 63 Great Pink and Tower-street, Red Wines. London P. W. Engs & Sons, 131 Front-street, New York LATOUR, LOUIS, [Illustration] Romanée (White). /Beaune/ Nuits (White Reuss, Lauteren, and Red). & Co., Volnay (do.). 39 Crutched Saint-Péray Friars, London (White). Chambertin (Red). LIGER-BELAIR, [Illustration] Carte d'Or COMTE, (White). /Nuits & Carte Vôsne/ Verte (do.). Fenwick, Parrot, Carte Noire & Co., 124 (Red and Fenchurch-street, White). London Carte Blanche (Red). MOËT AND CHANDON'S BRUT IMPÉRIAL DRY CHAMPAGNE. FACSIMILE OF LABEL. [Illustration] BRAND ON CORK. [Illustration] ALSO EXTRA SUPERIOR WHITE DRY SILLERY AND FIRST QUALITY CHAMPAGNES. CHAMPAGNE. PÉRINET & FILS, REIMS. [Illustration: Sectional View of a portion of the Caves in the Rue St. Hilaire.] DEUTZ & GELDERMANN'S 'GOLD LACK.' ================ MORNING POST. 'A Wine for Princes and Senators. The district of Ay has become probably the most celebrated in the ancient province of Champagne for its grapes, and among the noted brands of that famed region not one has gained a greater popularity in this country than that of Deutz & Geldermann. The Wine of this well-known firm is invariably met with on every important occasion; and it is noticed that Deutz & Geldermann's "Gold Lack" was specially selected for the banquet given by the Royal Naval Club at Portsmouth to H.R.H. the Prince of Wales; and some proof of its excellence may be gathered from the fact that this brand was drunk on a former visit of the Prince to the club two years since. Deutz & Geldermann's "Gold Lack" was one of the Champagnes supplied at the late Ministerial Whitebait Dinner at the Trafalgar.' WORLD. 'Deutz & Geldermann's "Gold Lack" is now being preferred by many connoisseurs, and we can bear testimony to its excellence of quality.' --------------- Deutz & Geldermann's 'Gold Lack' Champagne is shipped Brut, Extra Dry, and Medium Dry; and may be obtained of all Wine Merchants. --------------- /Wholesale Agents/: J. R. PARKINGTON & Co. 24 CRUTCHED FRIARS, LONDON, E.C. CHAMPAGNE. DEUX MÉDAILLES D'OR. [Illustration: PRO FIDE FIDES] CH^{ES.} DE CAZANOVE, AVIZE (/Champagne/). ================ VIN MONARQUE. Facsimiles of Medallion [Illustration: CH DE CAZANOVE AVIZE marne VIN MONARQUE] And Label of Extra Quality. [Illustration: PRO FIDE FIDES CH^{ES.} DE CAZANOVE AVIZE, (Champagne.) _Wholesale Agents for the United Kingdom, J. R. HUNTER & Co., 46 Fenchurch Street, London._] ROPER FRÈRES & CO.'S CHAMPAGNE. --------------- First Quality, Extra Dry at 48/- First Quality, Medium Dry at 48/- --------------- _For Luncheons and Wedding Breakfasts, Regimental Messes and Ball Suppers._ --------------- MORNING POST. 'The great feature of all entertainments, public banquets, &c., is ~Champagne~; but the high prices of really good wine naturally deter many a householder of moderate means from indulging in this luxury. /Roper Frères & Co/. are shipping ~a first quality Champagne at =48s.= per dozen~. At this price, it cannot be denied that the acme of cheapness is arrived at.' --------------- SPECIAL NOTICE. _All Wine Merchants can, ~if requested~, supply ROPER FRÈRES & Co.'s CHAMPAGNE at the above Prices; and the Public are therefore cautioned not to allow other Brands at similar prices to be substituted._ In 2 vols. square 8vo, price 32s. in handsome binding, AMERICA REVISITED. _From the Bay of New York to the Gulf of Mexico, and from Lake Michigan to the Pacific._ By GEORGE AUGUSTUS SALA, AUTHOR OF 'TWICE ROUND THE CLOCK,' 'PARIS HERSELF AGAIN,' &c. Illustrated with nearly 400 Engravings, many of them from Sketches by the Author. --------------- In crown 8vo, cloth gilt, SIDE-LIGHTS ON ENGLISH SOCIETY; OR _SKETCHES FROM LIFE, SOCIAL & SATIRICAL_. By the late E. C. GRENVILLE MURRAY. 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About. /DR. CLAUDE/; or Love rendered Desperate. By Hector Malot. 2 vols. /The Three Red Knights./ By Paul Féval. &c. &c. &c. --------------- THE SENSATIONAL NOVELS OF EMILE GABORIAU, _THE FAVOURITE READING OF PRINCE BISMARCK_. Price 1s. each, in ornamental covers. IN PERIL OF HIS LIFE. THE LEROUGE CASE. LECOQ THE DETECTIVE. 2 vols. OTHER PEOPLE'S MONEY. DOSSIER No. 113. THE MYSTERY OF ORCIVAL. Other Volumes are in progress. --------------- _London: VIZETELLY & Co., 42 Catherine Street, Strand._ MR. HENRY VIZETELLY'S POPULAR BOOKS ON WINE. =============== 'Mr. Vizetelly discourses brightly and discriminatingly on crus and bouquets and the different European vineyards, most of which he has evidently visited.'--_Times_. 'Mr. Henry Vizetelly's books about different wines have an importance and a value far greater than will be assigned them by those who look merely at the price at which they are published.'--_Sunday Times_. --------------- Price 1s. 6d. ornamental cover; or 2s. 6d. in elegant cloth binding, FACTS ABOUT PORT AND MADEIRA, With Notes on the Wines Vintaged around Lisbon, and the Wines of Teneriffe, GLEANED DURING A TOUR IN THE AUTUMN OF 1877. By HENRY VIZETELLY, /Wine Juror for Great Britain at the Vienna and Paris Exhibitions of 1873 and 1878/. _With One Hundred Illustrations from Original Sketches and Photographs._ --------------- ALSO BY THE SAME AUTHOR, Price 1s. 6d. ornamental cover; or 2s. 6d. in elegant cloth binding, FACTS ABOUT CHAMPAGNE, AND OTHER SPARKLING WINES, COLLECTED DURING NUMEROUS VISITS TO THE CHAMPAGNE AND OTHER VITICULTURAL DISTRICTS OF FRANCE, AND THE PRINCIPAL REMAINING WINE-PRODUCING COUNTRIES OF EUROPE. _With One Hundred and Twelve Engravings from Original Sketches and Photographs._ --------------- Price 1s. ornamental cover; or 1s. 6d. cloth gilt, FACTS ABOUT SHERRY, GLEANED IN THE VINEYARDS AND BODEGAS OF THE JEREZ, SEVILLE, MOGUER, AND MONTILLA DISTRICTS. _Illustrated with numerous Engravings from Original Sketches._ --------------- Price 1s. ornamental cover; or 1s. 6d. cloth gilt, THE WINES OF THE WORLD, CHARACTERISED AND CLASSED; /With some Particulars respecting the Beers of Europe/. --------------- _London: VIZETELLY & Co., 42 Catherine Street, Strand._ FOOTNOTES: [Footnote 1: Diodorus.] [Footnote 2: Idem.] [Footnote 3: Max Sutaine's _Essai sur le Vin de Champagne_.] [Footnote 4: This arch is said to have been called after the God of War from the circumstance of a temple dedicated to Mars being in the immediate neighbourhood. The sculptures still remaining under the arcades have reference to the months of the year, to Romulus and Remus, and to Jupiter and Leda. Reims formerly abounded with monuments of the Roman domination. According to M. Brunette, an architect of the city, who made its Roman remains his especial study, a vast and magnificent palace formerly stood nigh the spot now known as the Trois Piliers; while on the right of the road leading to the town were the arenas, together with a temple, among the ruins of which various sculptures, vases, and medals were found, and almost immediately opposite, on the site of the present cemetery, an immense theatre, circus, and xystos for athletic exercises. Then came a vast circular space, in the centre of which arose a grand triumphal arch giving entrance into the city. The road led straight to the Forum,--the Place des Marchés of to-day,--and along it were a basilica, a market, and an exedra, now replaced by the Hôtel de Ville. The Forum, bordered by monumental buildings, was of gigantic proportions, extending on the one side from half way down the Rue Colbert to the Place Royale, and on the other from near the Marché à la Laine, parallel with the Rue de Vesle, up to the middle of the Rue des Elus, where it terminated in a vast amphitheatre used for public competitions. Other buildings of less importance were situated here and there: the thermæ along the Rue du Cloître; a palace or a temple on the site of the archiepiscopal palace; another temple at the extremity of the Rue Vauthier le Noir, in the ruins of which a bas-relief and some small antique statues were discovered; a third temple in the Rue du Couchant, in which a votive altar was found. Four triumphal arches were erected at the four gates of the town: one dedicated to Mars; another to Ceres, on the same site as the gate of to-day; a third to Bacchus, in the present Rue de l'Université, in front of the Lycée; and the fourth to Venus, in the Rue de Vesle. Outside the walls, following the Rue du Barbâtre, the road was dotted with numerous graves according to the Roman custom; while on the site of the church of St. Remi there arose a temple and a palace, and on that of St. Nicaise a vast edifice which M. Brunette supposed to be the palace of the Consul Jovinus.] [Footnote 5: Henderson's _History of Ancient and Modern Wines_.] [Footnote 6: Gibbon's _Decline and Fall of the Roman Empire_.] [Footnote 7: Gibbon's _Decline and Fall of the Roman Empire_.] [Footnote 8: According to this document, published in Marlot's _Histoire de Reims_, he leaves to Bishop Lupus the vineyard cultivated by the vine-dresser Enias; to his nephew Agricola, the vineyard planted by Mellaricus at Laon, and also the one cultivated by Bebrimodus; to his nephew Agathimerus, a vineyard he had himself planted at Vindonisæ, and kept up by the labour of his own episcopal hands; to Hilaire the deaconess, the vines adjoining her own vineyard, cultivated by Catusio, and also those at Talpusciaco; and to the priests and deacons of Reims, his vineyard in the suburbs of that city, and the vine-dresser Melanius who cultivated it. The will is also noteworthy for its mention of a locality destined to attain a high celebrity in connection with the wine of Champagne, namely, the town of Sparnacus or Epernay, which a lord named Eulogius, condemned to death for high treason in 499 and saved at the bishop's intercession, had bestowed upon his benefactor, and which the latter left in turn to the church of Reims. To this church he also left estates in the Vosges and beyond the Rhine, on condition of furnishing pitch every year to the religious houses founded by himself or his predecessors to mend their wine-vessels, a trace of the old Roman custom of pitching vessels used for storing wine.] [Footnote 9: Marlot's _Histoire de Reims_.] [Footnote 10: Henderson's _History of Ancient and Modern Wines_.] [Footnote 11: Victor Fievet's _Histoire d'Epernay_.] [Footnote 12: Bertin du Rocheret's _Mélanges_.] [Footnote 13: Varin's _Archives Administratives de Reims_.] [Footnote 14: 'Bien met l'argent qui en bon vin l'emploie.' _Poems of Colin Musset_, 1190 to 1220.] [Footnote 15: Varin's _Archives Administratives de Reims_.] [Footnote 16: Ibid.] [Footnote 17: Ibid.] [Footnote 18: J. Gondry du Jardinet's _Agréable Visite aux Grands Crûs de France_.] [Footnote 19: 'Chanter me fait bon vin et rejouir.'] [Footnote 20: 'Le vin en tonel, Froit et fort et finandel, Pour boivre à la grant chaleur.'] [Footnote 21: Legrand d'Aussy's _Vie Privée des Français_.] [Footnote 22: 'Espernai dist et Auviler, Argenteuil, trop veus aviler Très-tos les vins de ceste table. Par Dieu, trop t'es fait conestable. Nous passons Chaalons et Reims, Nous ostons la goûte des reins, Nous estaignons totes les rois.' ] [Footnote 23: 'Espernai, trop es desloiaus; Tu n'as droit de parler en cour.' ] [Footnote 24: The 'vin d'Ausois,' or 'vin d'Aussai' (for it is spelt both ways in the poem), is not, as might be supposed, the wine of Auxois, an ancient district of Burgundy now comprised in the arrondissements of Sémur (Côte d'Or) and Avallon (Yonne), and still enjoying a reputation for its viticultural products. MM. J. B. B. de Roquefort and Gigault de la Bedollière, in their notes on Henri d'Andelys' poem, have clearly identified it with the wine of Alsace, that province having been known under the names in question during the Middle Ages. This explains its connection in the present instance with the Moselle.] [Footnote 25: An incidental proof that the English taste for strong wine was an early one. As late as the close of the sixteenth century the Bordeaux wines are described in the _Maison Rustique_ as 'thick, black, and strong.'] [Footnote 26: Probably either Aquila in the Abruzzi, or Aquiliea near Friuli.] [Footnote 27: The 'rouage' was a duty of 2 sous on each cart and 4 sous on each wagon laden with wine purchased by foreign merchants and taken out of the town. It was only one of many dues.] [Footnote 28: The old livre was about equal to the present franc; the sol was the twentieth part of a livre; and the denier the twelfth part of a sol, or about 1/24_d._ English.] [Footnote 29: Varin's _Archives Administratives de Reims_.] [Footnote 30: The Beaune cost 28 livres the tun of two queues; the St. Pourçain, a wine of the Bourbonnais, very highly esteemed in the Middle Ages, 12 livres the queue; and the wine of the district, white and red, 6 to 10 livres the queue of two poinçons. A poinçon, or demi-queue, of Reims was about 48 old English, or 40 imperial, gallons; while the demi-queue of Burgundy was over 45 imperial gallons.] [Footnote 31: Varin's _Archives Administratives de Reims_.] [Footnote 32: A few examples of the retail price of wine throughout the century at Reims may here be noted. For instance, a judgment of 1303 provided that all tavern-keepers selling wine at a higher rate than six deniers, or about a farthing per lot, the rate fixed by ancient custom, were to pay a fine of twenty-two sous. The lot or pot, for the two terms are indifferently used, was about the third of an old English gallon, four pots making a septier, and thirty-six septiers a poinçon or demi-queue, equal to about forty-eight gallons. The queue was therefore about ninety-six gallons at Reims, but at Epernay not more than eighty-five gallons. Not only had every district its separate measures,--those of Paris, for instance, differing widely from those of Reims,--but there were actually different measures used in the various lay and ecclesiastical jurisdictions into which Reims was divided. In the accounts of the Echevinage, wine, chiefly for presents to persons of distinction, makes a continual appearance. In 1335 it is noted that 'the presents of this year were made in wine at 16 deniers and 20 deniers the pot,' or about 2-1/4_d._ English per gallon. In 1337-8 prices ranged from 3/4_d._ to 4-1/2_d._ English per gallon, showing a variety in quality; and in 1345 large quantities were purchased at the first-mentioned rate, five quarts of white wine fetching 2_d._ English. In 1352 from a 1_d._ to 2-1/4_d._ was paid per gallon, and five crowns for two queues. In 1363 the citizens, a hot-headed turbulent lot, who were always squabbling with their spiritual and temporal superior and assailing his officers, when not assaulting each other or pulling their neighbours' houses down, successfully resisted the pretensions of the archbishop to regulate the price of wine when the cheapest was worth 12 deniers per pot, or 1-1/2_d._ per gallon. The dispute continued, and in 1367 a royal commission was issued to the bailli of Vermandois, the king's representative, to inquire into the right of the burghers to sell wine by retail at 16 deniers, as they desired. The report of the bailli was that a queue of old French wine being worth about 20 livres, or 16_s._ 8_d._, and wine of Beaune and other better and stronger wines being sold in the town at higher rates, French wine might be sold as high as 3-1/2d. English per gallon, and Beaune at 4-1/2_d._ The great increase in production, and consequent fall in price, is shown by the wine found in Archbishop Richard Pique's cellar in 1389 being valued, on an average, at only 1_s._ 6_d._ per queue.] [Footnote 33: Froissart's _Chronicles_.] [Footnote 34: Idem.] [Footnote 35: Idem.] [Footnote 36: What with one kind of assessment being adopted for wine sold wholesale and another for that disposed of by retail, with one class of dues being levied on wine for export and another on that for home consumption, and with the fact of certain duties being in some cases payable by the buyer and in others by the seller, any attempt to summarise this section of the story of the wines of Reims would be impossible. The difficulty is increased when it is remembered that in the Middle Ages Reims was divided into districts, under the separate jurisdictions of the eschevins, the archbishop, the chapter of the cathedral, the Abbeys of St. Remi and St. Nicaise, and the Priory of St. Maurice, in several of which widely varying measures were employed down to the sixteenth century, and between which there were continual squabbles as to the rights of vinage, rouage, tonnieu, &c.] [Footnote 37: Varin's _Archives Administratives de Reims_.] [Footnote 38: Froissart's _Chronicles_.] [Footnote 39: Baron Taylor's _Reims; la Ville de Sacres_.] [Footnote 40: Amongst the better known are Chamery, where the archbishop had a house, vineyard, and garden, let for 3_s._ per annum, about five _jours_ of vineyard and two _jours_ of very good vineland; Mareuil, whence he drew ten hogsheads of wine annually; Rilly, Verzenay, Sillery, Attigny, &c. The _jour_ cost from 5 to 8 livres per annum for cultivation, and the stakes for the vines 4 sols, or 2_d._, a hundred.] [Footnote 41: The chapter of the Cathedral, the church of Notre Dame, the abbeys of St. Remi and St. Nicaise, had vineyards or 'droits de vin' at Hermonville, Rounay les Reims, Montigny, Serzy, Villers Aleran, Maineux devant Reims, Mersy, Sapiecourt, Sacy en la Montagne, Flory en la Montagne, Prouilly, Germigny, Saulx, Bremont, Merfaud, Trois Pins, Joucheri sur Vesle, Villers aux Neux, &c.; the last named also possessing a piece of 'vingne gonesse' at 'a place called Mont Valoys in the territory of Reims.'] [Footnote 42: At his château at the Porte Mars were forty-four queues of red and white wine, nineteen of new red and white wine, and four of old wine, valued, on an average, at 36 sols or 1_s._ 6_d._ the queue; at Courville there were fifty queues of new wine (valued at 30 sols the queue), twenty of old wine (worth nothing), and four 'cuves' for wine-making; and at Viellarcy, eighteen tuns of new wine, valued at 60 sols or 2_s._ 6_d._ per tun. To take charge of all these, Jehan le Breton, the defunct prelate's assistant butler, was retained by the executors for half a year, at the wages of 74 sols or 3_s._ 2_d._ At the funeral feast there were consumed three queues of the best wine in the cellars, valued at 2_s._ 7-1/2_d._ per queue, three others at 1_s._ 3_d._, and five pots of Beaune at 1-2/3_d._ English per pot, showing it to have been four times as valuable as native growths.] [Footnote 43: 'En Picardie sont li bourdeur, Et en Champagne li buveur.... Telz n'a vaillant un Angevin Qui chascun jor viant boire vin.' ] [Footnote 44: 'Champagne est la forme de tout bien De blé, de vin, de foin, et de litière.' ] [Footnote 45: Mss. de Rogier, Max Sutaine's _Essai sur le Vin de Champagne_, &c.] [Footnote 46: This wine, no doubt, came from a considerable distance round, for we find P. de la Place, a mercer of Reims, seeking in 1409 to recover the value of five queues and two poinçons 'of wine from the cru of the town of Espernay, on the river of Esparnay,' delivered at Reims to J. Crohin of Hainault, the origin of the same being certified by S. de Laval, a sworn wine-broker, 'who knows and understands the wines of the country around Reims.'] [Footnote 47: Varin's _Archives Administratives de Reims_.] [Footnote 48: Max Sutaine's _Essai sur le Vin de Champagne_.] [Footnote 49: Varin's _Archives Administratives de Reims_. The Hôtel de la Maison Rouge occupies to-day the site of the old hostelry at which the parents of Jeanne Darc were housed.] [Footnote 50: Varin's _Archives Administratives de Reims_.] [Footnote 51: The cost of the wine thus presented seems to have averaged from 2-1/4_d._ to 3_d._ per gallon. In 1477 a queue of old wine was valued at no less than 30_s._] [Footnote 52: The twelve peers of France first appear at the coronation of Philip Augustus. There were six lay peers and six ecclesiastical peers: Duke of Burgundy. " Normandy. " Guienne or Aquitaine. Count of Toulouse. " Flanders. " Champagne. Archbishop Duke of Reims. Bishop Duke of Laon. " " Langres. Bishop Count of Beauvais. " " Chalons. " " Noyon. As the titles of the lay peers grew extinct, and their fiefs lapsed to the crown, it became customary for them to be represented by some great nobles at the coronations of the kings of France.] [Footnote 53: The following is the full text of this singular sentence. The injunction at the end, respecting the payment of tithes without fraud, shows that even in a matter like this the Church did not lose sight of its own interests. 'In the name of the Lord, amen. Having seen the prayer or petition on behalf of the inhabitants of Villenauxe, of the diocese of Troyes, made before us, official of Troyes, sitting in judgment upon the _bruhecs_ or _éruches_, or other similar animals, which, according to the evidence of persons worthy of belief and as confirmed by public rumour, have ravaged for a certain number of years, and this year also, the fruit of the vines of this locality, to the great loss of those who inhabit it and of the persons of the neighbourhood,--petition that we warn the above-named animals, and that, using the means at the Church's disposition, we force them to retire from the territory of the said place. Having seen and attentively examined the motives of the prayer or petition above mentioned, and also the answers and allegations furnished in favour of the said _éruches_ or other animals by the councillors chosen by us for that purpose; having heard also on the whole our promoter, and seeing the particular report, furnished at our command by a notary of the said Court of Troyes, on the damage caused by the said animals amongst the vines of the locality of Villenauxe already named; though it would seem that to such damage one can bring no remedy except through the aid of God; however, taking into consideration the humble, frequent, and pressing complaint of the above-mentioned inhabitants; having regard, especially, to the ardour with which, to efface their past great faults, they lately gave, at our invitation, the edifying spectacle of solemn prayers; considering that, as the mercy of God does not drive away the sinners who return to Him with humility, neither should His Church refuse, to those who run to her, succour or consolation,--We, the official above named, no matter how novel the case may be, yielding to the earnestness of these prayers, following in the footsteps of our predecessors presiding at our tribunal, having God before our eyes and full of belief in His mercy and love, after having taken counsel in the proper quarter, we deliver sentence in the following terms: 'In the name and in virtue of the omnipotence of God, of the Father, the Son, and the Holy Ghost; of the blessed Mary, mother of our Lord Jesus Christ; of the authority of the holy apostles Peter and Paul; and of that with which we ourselves are invested in this affair, we charge by this act the above-named animals--_bruches_, _éruches_, or of any other name by which they may be called--to retire (under penalty of malediction and anathema, within the six days which follow this warning and in accordance with our sentence) from the vines and from the said locality of Villenauxe, and never more to cause, in time to come, any damage, either in this spot or in any other part of the diocese of Troyes; that if, the six days passed, the said animals have not fully obeyed our command, the seventh day, in virtue of the power and authority above mentioned, we pronounce against them by this writing anathema and malediction! Ordering, however, and formally directing the said inhabitants of Villenauxe, no matter of what rank, class, or condition they may be, so as to merit the better from God, all-powerful dispensator of all good and deliverer from all evil, to be released from such a great plague; ordering and directing them to deliver themselves up in concert to good works and pious prayers; to pay, moreover, the tithe without fraud and according to the custom recognised in the locality; and to abstain with care from blaspheming and all other sins, especially from public scandals.--Signed, /N. Hupperoye/, Secretary.'] [Footnote 54: It has been asserted that the Champagne, and notably the town of Troyes, enjoyed the dubious honour of furnishing fools to the court of France. There is certainly a letter of Charles V. to the notables of Troyes, asking them, 'according to custom,' for a fool to replace one named Grand Jehan de Troyes, whom he had had buried in the church of St. Germain l'Auxerrois, and who has been immortalised by Rabelais. But Brusquet was a Provençal; Triboulet, his predecessor, immortalised by Victor Hugo in the 'Roi s'amuse,' a native of Blois; Chicot the Jester, the fool of Henry III., and the favourite hero of Dumas, a Gascon; and Guillaume, his successor, a Norman.] [Footnote 55: The wine of Reims provided at the coronation of Francis II., in 1559, cost from 11_s._ 8_d._ to 15_s._ 10_d._ per queue of ninety-six gallons, and the Burgundy 16_s._ 8_d._ per queue, which, allowing for the cost of transport, would put them about on an equality. At the coronation of Charles IX., in 1561, Reims wine cost from 23_s._ 4_d._ to 28_s._ _4d._; and at that of Henry III., in 1575, from 45_s._ to 62_s._ 6_d._ per queue,--a sufficient proof of the rapidly-increasing estimation in which the wine was held.] [Footnote 56: Paulmier's treatise _De Vino et Pomaceo_ (Paris, 1588).] [Footnote 57: Jehan Pussot's _Mémorial du Temps_.] [Footnote 58: Ibid. Many details respecting the yield of the vines and vineyards of the Mountain and the River are preserved in this _Mémorial_, which extends from 1569 to 1625, and the author of which was a celebrated builder of Reims. During the last thirty years of the century the vines seem to have suffered greatly from frost and wet. Sometimes the wine was so bad that it was sold, as towards the end of 1579, at 5_s._ 6_d._ the queue; at others it was so scarce that it rose, as at the vintage of 1587, to 126_s._ 8_d._ the queue. At the vintage of 1579 the grapes froze on the vines, and were carried to the press in sacks. At the commencement of the vintage the new wine fetched from 12_s._ to 16_s._ the queue, but it turned out so bad that by Christmas it was sold at 5_s._ 6_d._] [Footnote 59: _Maison Rustique_ (1574).] [Footnote 60: Jehan Pussot's _Mémorial du Temps_.] [Footnote 61: During the first twenty-five years of the century Pussot shows the new wine to have averaged from about 23_s._ to 46_s._ the queue, according to quality. In 1600 and 1611 it was as low as 16_s._, and in 1604 fetched from merely 12_s._ to 32_s._ On the other hand, in 1607, it fetched from 57_s._ to 95_s._, and in 1609 from 79_s._ to 95_s._] [Footnote 62: Feillet's _La Misère aux temps de la Fronde_.] [Footnote 63: Dom Guillaume Marlot's _Histoire de Reims_.] [Footnote 64: Pluche's _Spectacle de la Nature_.] [Footnote 65: St. Simon's _Mémoires_.] [Footnote 66: _Mémoire sur la manière de cultiver la vigne et de faire le vin en Champagne._] [Footnote 67: Lavardin, Bishop of Le Mans, and himself a great _gourmet_, was one day at dinner with St. Evremond, and began to rally the latter on the delicacy of himself and his friends the Marquis de Bois Dauphin and the Comte d'Olonne. 'These gentlemen,' said the prelate, 'in seeking refinement in everything carry it to extremes. They can only eat Normandy veal; their partridges must come from Auvergne, and their rabbits from La Roche Guyon, or from Versin; they are not less particular as to fruit; and as to wine, they can only drink that of the good _coteaux_ of Ay, Hautvillers, and Avenay.' St. Evremond having repeated the story, he, the marquis, and the count were nicknamed 'the three coteaux.' Hence Boileau, in one of his satires, describes an epicurean guest as 'profès dans l'ordre des coteaux.'] [Footnote 68: St. Evremond's Works (London, 1714).] [Footnote 69: _L'Art de bien traiter ... mis en lumière_, par L. S. R. (Paris, 1674).] [Footnote 70: Brossette's notes to Boileau's Works (1716). Bertin du Rocheret, in correcting this error in the _Mercure_ of January 1728, points out that neither the family of Colbert nor that of Le Tellier ever owned a single vinestock of the River, and that their holdings on the Mountain were very insignificant.] [Footnote 71: 'Il n'est cité que je préfère à Reims, C'est l'ornement et l'honneur de la France; Car sans conter l'ampoule et les bons vins, Charmants objets y sont en abondance.' _Les Rémois._ ] [Footnote 72: 'Sur quelle vigne à Reims nous avons hypothèque; Vingt muids, rangés chez moi, font ma bibliothèque.' _Le Lutrin_, chant iv. 1674.] [Footnote 73: St. Simon's _Mémoires_.] [Footnote 74: Ibid.] [Footnote 75: Ibid.] [Footnote 76: Max Sutaine's _Essai sur le Vin de Champagne_, 1845.] [Footnote 77: Henderson's _History of Ancient and Modern Wines_.] [Footnote 78: _Æneid_, i. 738.] [Footnote 79: Henderson's _History of Ancient and Modern Wines_.] [Footnote 80: Max Sutaine's _Essai sur le Vin de Champagne_.] [Footnote 81: --------'Petars de Chaalons, Qui le ventre enfle et les talons.' ] [Footnote 82: Louis Perrier's _Mémoire sur le Vin de Champagne_, 1865.] [Footnote 83: _De Naturali Vinorum Historiâ._ Rome, 1596.] [Footnote 84: _L'Art de bien traiter_, &c.] [Footnote 85: _Maison Rustique_, 1574.] [Footnote 86: Max Sutaine's _Essai sur le Vin de Champagne_.] [Footnote 87: Pluche's _Spectacle de la Nature_.] [Footnote 88: Idem and _Maison Rustique_, 1582. M. Louis Perrier, in his _Mémoire sur le Vin de Champagne_, says that the Ay wines yield but little _mousse_.] [Footnote 89: Max Sutaine's _Essai sur le Vin de Champagne_.] [Footnote 90: St. Evremond's letter to the Comte d'Olonne, already noticed. In another epistle to Lord Galloway, dated 29th August 1701, he observes: 'As to M. de Puisieux (Roger Brulart, Marquis de Puisieux et de Sillery and Governor of Epernay), in my opinion he acts very wisely in falling in with the bad taste now in fashion as regards Champagne wine, in order the better to sell his own. I could never have thought that the wines of Reims could have been changed into wines of Anjou, from their colour and their harshness (_verdeur_). There ought to be a harshness (_vert_) in the wine of Reims, but a harshness with a colour, which turns into a sprightly tartness (_sêve_) when it is ripe; ... and it is not to be drunk till the end of July.... The wines of Sillery and Roncières used to be kept two years, and they were admirable, but for the first four months they were nothing but verjuice. Let M. de Puisieux make a little barrel (_cuve_) after the fashion in which it was made forty years ago, before this depravity of taste, and send it to you.' St. Evremond's Works, English edition of 1728.] [Footnote 91: Max Sutaine's _Essai sur le Vin de Champagne_.] [Footnote 92: Dom Guillaume Harlot's _Histoire de Reims_.] [Footnote 93: Ibid.] [Footnote 94: Henderson's _History of Ancient and Modern Wines_.] [Footnote 95: Letter of Dom Grossart to M. Dherbès of Ay. The measurement of the arpent varied from an acre to an acre and a half.] [Footnote 96: Varin's _Archives Administratives de Reims_.] [Footnote 97: Pluche's _Spectacle de la Nature_.] [Footnote 98: Letter of Dom Grossart to M. Dherbès of Ay.] [Footnote 99: Ibid.] [Footnote 100: Ibid.] [Footnote 101: Bertall's _La Vigne_. Paris, 1878.] [Footnote 102: _Mémoire sur la Manière de cultiver la Vigne et de faire le Vin en Champagne._ This work is believed to have been written by Jean Godinot, a canon of Reims, born in 1662. Godinot was at the same time a conscientious Churchman, a skilled viticulturist, and a clever merchant, who enriched himself by disposing of the wine from his vineyards at Bouzy, Taissy, and Verzenay, and distributed his gains amongst the poor. He died in 1747, after publishing an enlarged edition of the _Mémoire_ in 1722, in which the phrase 'for the last three years' becomes 'the last seven or eight years.' Godinot's friend Pluche used the _Mémoire_ as the basis for the section 'Wine' in his _Spectacle de la Nature_.] [Footnote 103: Letter of Dom Grossart to M. Dherbès of Ay.] [Footnote 104: Ibid.] [Footnote 105: Louis Perrier's _Mémoire sur le Vin de Champagne_.] [Footnote 106: Letter of M. le Pescheur, 1706.] [Footnote 107: Pluche's _Spectacle de la Nature_.] [Footnote 108: In Brossette's notes to his edition of Boileau's Works of 1716.] [Footnote 109: The inscription above given is an exact transcript from the black-marble slab, and any errors in orthography are due either to the original author or to the mason who incised it.] [Footnote 110: The following account of Dom Perignon and his discoveries is contained in a letter dated 25th October 1821, and addressed from Montier-en-Der, Haute Marne, to M. Dherbès of Ay, by Dom Grossart, the last procureur of the Abbey of Hautvillers. Dom Grossart, who had fled from France during the troublous times of the Revolution, was at the date of the letter in his seventy-fourth year. 'You know, sir, that it was the famous Dom Perignon, who was procureur of Hautvillers for forty-seven years, and who died in 1715, who discovered the secret of making sparkling and non-sparkling white wine, and the means of clearing it without being obliged to _dépoter_ the bottles, as is done by our great wine-merchants rather twice than once, and by us never. Before his time one only knew how to make straw-coloured or gray wine. In bottling wine, instead of corks of cork-wood, only tow was made use of, and this species of stopper was saturated with oil. It was in the marriage of our wines that their goodness consisted; and this Dom Perignon towards the end of his days became blind. He had instructed in his secret of fining the wines (_de coller les vins_) a certain Brother Philip, who was for fifty years at the head of the wines of Hautvillers, and who was held in such consideration by M. Le Tellier, Archbishop of Reims, that when this brother went to Reims he made him come and sit at table with him. When the vintage drew near, he (Dom Perignon) said to this brother, "Go and bring me some grapes from the Prières, the Côtes-à-bras, the Barillets, the Quartiers, the Clos Sainte Hélène," &c. Without being told from which vineyard these grapes came, he mentioned it, and added, "the wine of such a vineyard must be married with that of such another," and never made a mistake. To this Brother Philip succeeded a Brother André Lemaire, who was for nearly forty years at the head of the cellars of Hautvillers, that is to say, until the Revolution.... This brother being very ill, and believing himself on the point of death, confided to me the secret of clarifying the wines, for neither prior nor procureur nor monk ever knew it. I declare to you, sir, that we never did put sugar in our wines; you can attest this when you find yourself in company where it is spoken of. Monsieur Moët, who has become one of the _gros bonnets_ of Champagne since 1794, when I used to sell him plenty of little baskets, will not tell you that I put sugar in our wines. I make use of it at present upon some white wines which are vintaged in certain _crûs_ of our wine district. This may have led to the error. 'As it costs much to _dépoter_, I am greatly surprised that no wine-merchant has as yet taken steps to learn the secret of clearing the wine without having to _dépoter_ the bottles when once the wine has been put into them.'] [Footnote 111: Louis Perrier's _Mémoire sur le Vin de Champagne_.] [Footnote 112: _Mémoire_ of 1718.] [Footnote 113: Ibid. Pluche, in his _Spectacle de la Nature_, 1732, also says: 'If the wine be drawn off towards the end of March, when the sap begins to rise in the vine, it will froth to such a degree as to whiten like milk, to the very bottom of the glass, the moment it is poured out. Wine will sometimes acquire this quality if it be drawn off during the ascent of the sap in August, which makes it evident that the froth is occasioned by the operation of the air and sap, which then act with vigour in the wood of the vine, and likewise in the liquor it produced. This violent ebulition, which is so agreeable to some persons, is thought by connoisseurs to be inconsistent with the goodness of the wine, since the greenest may be made to whiten into a froth, and the most perfect wines seldom discover this quality.' In an article in the _Journal de Verdun_ of November 1726, the following passage occurs: 'A wine merchant of Anjou having written some time back to a celebrated magistrate in Champagne, Bertin du Rocheret, begging him to forward the secret of making _vin mousseux_ during the vintage, the magistrate answered, "That _vin mousseux_ was not made during the vintage; that there was no special soil for it; that the Anjou wines were suitable, since poor wine froths as well as the most excellent, frothing being a property of thin poor wine. That to make wine froth, it was necessary to draw it off as clear as could be done from the lees, if it had not been already racked; to bottle it on a fine clear day in January or February, or in March at the latest; three or four months afterwards the wine will be found effervescent, especially if it has some tartness and a little strength. When the wine works (like the vine) your wine will effervesce more than usual; a taste of vintage and of fermentation will be found in it." The excellent wines of Ay and our good Champagne wines do not froth, or very slightly; they content themselves with sparkling in the glass.'] [Footnote 114: St. Simon's _Mémoires_.] [Footnote 115: Ibid.] [Footnote 116: _Mémoire_ of 1718.] [Footnote 117: Ibid.] [Footnote 118: Antony Réal's _Ce qu'il y a dans une Bouteille de Vin_.] [Footnote 119: Legrand d'Aussy's _Vie Privée des Français_.] [Footnote 120: 'Là le nombre et l'éclat de cent verres bien nets Répare par les yeux la disette des mets; Et la mousse petillante D'un vin délicat et frais D'une fortune brillante Cache à mon souvenir les fragiles attraits.' ] [Footnote 121: 'Quant à la muse de St. Maur Que moins de douceur accompagne. Il lui faut du vin de Champagne Pour lui faire prendre l'essor.' ] [Footnote 122: 'Alors, grand' merveille, sera De voir flûter vin de Champagne.' ] [Footnote 123: 'Sur ce rivage emaillé, Où Neuillé borde la Seine, Reviens au vin d'Hautvillé Mêler les eaux d'Hypocrène.' ] [Footnote 124: 'Phébus adonc va se désabuser De son amour pour la docte fontaine, Et connoîtra que pour bon vers puiser Vin champenois vaut mieux qu'eau d'Hippocrène.' ] [Footnote 125: The father, Adam Bertin du Rocheret, was born in 1662, and died in 1736; his son, Philippe Valentin, the _lieutenant criminel_ at Epernay, was born in 1693, and died in 1762. Both owned vineyards at Epernay, Ay, and Pierry, and were engaged in the wine-trade, and both left a voluminous mass of correspondence, &c., extracts from which have been given by M. Louis Perrier in his _Mémoire sur le Vin de Champagne_. The Marshal was an old customer. At the foot of a letter of his of the 20th December 1705, asking for 'two quartaux of the most excellent vin de Champagne, and a pièce of good for ordinary drinking,' Bertin has written, 'I will send you, as soon as the river, which is strongly flooded, becomes navigable, the wine you ask for, and you will be pleased with it; but as the best new wine is not of a quality to be drunk in all its goodness by the spring, I should think that fifty flasks of old wine, the most exquisite in the kingdom that I can furnish you with, together with fifty other good ones, will suit you instead of one of the two caques.'] [Footnote 126: _Tocane_ was a light wine obtained, like the best Tokay, from the juice allowed to drain from grapes slightly trodden, but not pressed. It had a flavour of _verdeur_, which was regarded as one of its chief merits, and would not keep more than six months. Though at one time very popular, and largely produced in Champagne, it is now no longer made. The wine of Ay enjoyed a high reputation as _tocane_.] [Footnote 127: Louis Perrier's _Mémoire sur le Vin de Champagne_.] [Footnote 128: Letter of Dom Grossart.] [Footnote 129: Louis Perrier's _Mémoire sur le Vin de Champagne_.] [Footnote 130: Ample details of the systems of viticulture and wine-making pursued in the Champagne at the commencement of the eighteenth century are to be found in the anonymous _Mémoire_ published in 1718. These are reproduced to a great extent in the _Spectacle de la Nature_ of Noel Antoine Pluche, a native of Reims, who composed this work (published in 1732) for the benefit of the son of Lord Stafford, to whom he was tutor. The Abbé Pluche, after being professor of humanity and rhetoric at the University of Reims, was about to enter into holy orders, but being denounced as an opponent of the Bull Unigenitus, abandoned all ideas of preferment, and devoted himself to private tuition and the composition of his great work, the _Spectacle de la Nature_. This last is a perfect encyclopædia, in the form of a series of dialogues, recalling those in Mrs. Barbauld's _Evenings at Home_, the interlocutors being the Count, the Countess, the Chevalier, and the Prior; and the style may be best judged from the following extracts from the contemporary translation of Mr. Samuel Humphries. In Dialogue XIII. on 'Vines,' the Count remarks that, after studying the methods of viticulture followed in different provinces, he 'could not discover any to be ranked in Competition with those Precautions that have been taken by the Inhabitants of Champaign' in the production of their wine. By 'a long Course of Experience' they had 'acquired the proper Method of tinging it with the Complexion of a Cherry, or the Eye of a Partridge. They could likewise brighten it into the whitest Hue, or deepen it into a perfect Red.' In the succeeding Dialogue on 'Wines,' the Count states that 'Vines vary in their Qualities. Some are planted in a very light and strong Soil, and they yield a bright and fragrant Wine; others are placed in a more nourishing Tract of Land, and they produce a Wine of a greater Body. The reasonable Combination of these different Fruits will produce an exquisite Liquor, that will have all the Advantages of a sufficient Body, a Delicacy of Flavour, a Fragrancy of Scent, and a Liveliness of Colour, and which may be Kept for several Years without the least Alteration. It was the Knowledge of those Effects that result from intermixing the Grapes of three or four Vines of different Qualities, which improved the celebrated Wines of Sillery, Ai, and Hautvillers to the Perfection they have now acquired. Father Parignon, a Benedictine of Hautvillers on the Marne, was the first who made any successful Attempt to intermix the Grapes of the different Vines in this manner, and the Wine of Perignon d'Hautvillers bore the greatest Estimation amongst us till the Practise of this Method became more extensive.' The Count notes that white wines from white grapes being deficient in strength, and apt to grow yellow and degenerate before the next return of summer, had gone out of repute, except for some medicinal prescriptions, whilst 'the grey Wine, which has so bright an Eye and resembles the Complexion of Crystal, is produced by the blackest Grapes.' 'The Wine of a black Grape may be tinged with any Colour we think proper; those who desire to have it perfectly White have recourse to the following Method. The People employed in the Vintage begin their Labours at an early Hour in the Morning; and when they have selected the finest Grapes, they lay them gently in their Baskets, in order to be carried out of the Vineyard; or they place them in large Panniers, without pressing them in the least or wiping off the dewy Moisture or the azure Dye that covers them. Dews and exhaling Mists greatly contribute to the Whiteness of the Wine. 'Tis customary to cover the Baskets with wet Cloths in a hot Sunshine, because the Liquor will be apt to assume a red Tincture if the Grapes should happen to be heated. These Baskets are then placed on the Backs of such Animals as are of a gentle Nature, and carry their Burdens with an easy Motion to the Cellar, where the Grapes continue covered in a cool Air. When the Warmth of the Sun proves moderate, the Labours of the Vintage are not discontinued till Eleven in the Morning; but a glowing Heat makes it necessary for them to cease at Nine.' Yet even these precautions were liable to fail, since 'the Heat of the Sun and the Shocks of the Carriages are sometimes so violent, and produce such strong Effects upon the exterior Coat of the Grapes, that the Fluids contained in that Coat, and which are then in Motion, mix themselves with the Juice of the Pulp at the first Pressing; in consequence of which, the Extraction of a Wine perfectly white is rendered impracticable, and its Colour will resemble the Eye of a Partridge, or perhaps some deeper Hue. The Quality of the Wine is still the same; but it must be either entirely White or Red, in order to prove agreeable to the Taste and Mode which now prevail.' The Count describes the two pressings and five cuttings, the latter term derived from the squaring of the mass of grapes with the cutting peel, and the system of 'glewing' this wine, 'the weight of an _ecu d'or_' of 'Fish Glew, which the Dutch import amongst us from Archangel,' being added to each _pièce_, with the addition sometimes of a pint of spirits of wine or brandy. He then explains the method practised of drawing off the wine without disturbing the barrels, by the aid of a tube and a gigantic pair of bellows. The vessels were connected by the former, and the wine then driven from one to the other by the pressure of air pumped in by means of the latter. A sulphur-match was burnt in the empty vessels, so that it might 'receive a Steam of Spirits capable of promoting the natural Fire and bright Complexion of the Liquor.' Noting that the wines should be again 'glewed' eight days before they are bottled, Pluche says: 'The Month of March is the usual Season for glewing the most tender Wines, such as those of Ai, Epernai, Hautvilliers, and Pieri, whose chief Consumption is in France; but this Operation should not be performed on such strong Wines as those of Sillery, Verzenai, and other Mountain Wines of Reims, till they are twelve Months old, at which Time they are capable of supporting themselves for several Years. When these Wines are bottled off before they have exhaled their impetuous Particles, they burst a Number of Bottles, and are less perfect in their Qualities. The proper Method of bottling Wine consists in leaving the Space of a Finger's Breadth between the Cork and the Liquor, and in binding the Cork down with Packthread; it will also be proper to seal the Mouths of the Bottles with Wax, to prevent Mistakes and Impositions. The Bottles should likewise be reclined on one Side, because if they are placed in an upright Position, the Corks will grow dry in a few Months for want of Moisture, and shrink from their first Dimensions. In Consequence of which a Passage will be opened to the external Air, which will then impart an Acidity to the Wine, and form a white Flower on the Surface, which will be an Evidence of its Corruption.' The _Mémoire_ of 1718 also points out the necessity of leaving a space between the cork and the wine, saying that without this, when the wine began to work at the different seasons of the year, it would break a large number of bottles; and that even despite this precaution large numbers are broken, especially when the wine is a little green. The ordinary bottles for Champagne, styled _flacons_, or flasks, held 'a _pinte de Paris_, less half a glass,' and cost from 12 to 15 francs the hundred; and as wood abounded in the province, several glass-works were established there for their manufacture. As the bottling of the wine, especially in the early years, was mostly to order, many customers had their flasks stamped with their arms, at a cost of about 30 per cent more. The corks--'solid, even, and not worm-eaten'--cost from 50 to 60 sols per hundred. Wire was as yet quite unknown. The cost of bottling a poinçon of wine in 1712 was: for 200 bottles, 30 livres; 200 corks, 3 livres; 2 baskets and packing, 8 livres; bottling, string, and sealing, 3 livres; total, 44 livres, or say 36 shillings. It would appear from the _Mémoire_ that the pernicious practice of icing still Champagne, already noticed, continued in vogue as regards sparkling wine. The wine was recommended to be taken out of the cellar half an hour before it was intended it should be drunk, and put into a bucket of water with two or three pounds of ice. The bottle had to be previously uncorked, and the cork lightly replaced, otherwise it was believed there was danger of the bottle breaking. A short half an hour in the ice was said to bring out the goodness of the wine. Bertin du Rocheret counselled the use of ice to develop the real merits of a vinous wine of Ay.] [Footnote 131: Max Sutaine's _Essai sur le Vin de Champagne_.] [Footnote 132: _Mémoires_ of 1718 and 1722.] [Footnote 133: Ibid.] [Footnote 134: Max Sutaine's _Essai sur le Vin de Champagne_.] [Footnote 135: _Mémoire_ of 1718. The perils to which it was exposed during this transit are pointed at in a letter to the elder Bertin from a customer in Paris in 1689: 'I thought it better to wait before giving you any news of the wine you sent me until it was fit to drink. I tapped it yesterday, and found it poor. I can hardly believe but that the boatmen did not fall-to upon it whenever they had need, and took great care to fill it up again, for it could not have been fuller than they delivered it.'] [Footnote 136: Pluche's _Spectacle de la Nature_, 1732.] [Footnote 137: _Mémoire_ of 1718.] [Footnote 138: Louis Perrier's _Mémoire sur le Vin de Champagne_. In the _Mémoire_ of 1718, Ay, Epernay, Hautvillers, and Cumières are alone classed as _Vins de Rivière_; Pierry, Fleury, Damery, and Venteuil being reckoned only as _Petite Rivière_; and there being no mention of Avize and the neighbouring vineyards.] [Footnote 139: As at Vertus, where the red wine, so highly esteemed by William III. of England, was replaced by sparkling wine.] [Footnote 140: Max Sutaine's _Essai sur le Vin de Champagne_.] [Footnote 141: _Ergo vinum Belnense potuum est suavissimus, ita et saluberrimus._] [Footnote 142: _An vinum Remense sit omnium saluberrimum._] [Footnote 143: Of Ay, Avenay, and Hautvillers (note of Tallemant's editor).] [Footnote 144: Tallemant des Réaux's _Historiettes_.] [Footnote 145: Champagne has been accused of producing not only gout, but stone, gravel, and rheumatism. As to the first-named complaint, Bertin du Rocheret disposes of it by noting, in a list compiled by him of all the deaths of any moment at Epernay, from 1644 downwards, the decease, at the age of seventy-five, on January 1, 1733, of Jeanne Maillard, 'the only person in the district ever attacked by the gout.' His brother-in-law, Dr. Jacques de Reims, in a letter to Helvetius in 1730, asserts that this complaint is only known by name in the Champagne; and that, as regards the stone, not more than ten people were affected therewith within a radius of ten leagues. He maintained that the _non-mousseux_ white wine of the Champagne, drunk at maturity and tempered with water, was the best of all beverages for preserving general health; and the eminent Dr. Camille Falconnet held the same opinion. Arthur Young, moreover, furnishes spontaneous testimony with regard to rheumatism. Extolling the sparkling wine of Reims in 1787, he says, 'I suppose fixed air is good for the rheumatism; I had some writhes of it before I entered Champagne, but the _vin mousseux_ has absolutely banished it;' and on reaching Ove, he regrets that 'the _vin de Champagne_, which is forty sous at Reims, is three livres here, and execrably bad; so there is an end of my physic for the rheumatism' (_Travels in France in 1787-9_).] [Footnote 146: _An vinum Remense Burgundico suavius et salubrius._] [Footnote 147: In his ode entitled _Vinum Burgundum_, the passage aspersing the wines of Reims runs as follows: 'Nam suum Rhemi licet usque Bacchum Jactitent: æstu petulans jocoso Hic quidam fervet cyathis, et aura Limpidus acri. Vellicat nares avidas; venenum At latet: multos facies fefellit, Hic tamen spargat modico secundam Munere mensam.' The French version, by M. de Bellechaume, entitled an 'Ode au Vin de Bourgogne,' and published in his _Recueil des Poésies latines et françaises sur les Vins de Champagne et de Bourgogne_, Paris 1712, is as follows: 'Vante, Champagne ambitieuse, L'odeur et l'éclat de ton vin, Dont la sève pernicieuse Dans ce brillant cache un venin, Tu dois toute ta gloire en France, A cette agréable apparence, Qui nous attire et nous séduit; Qu'à Beaune ta liqueur soumise Dans les repas ne soit admise, Que sagement avec le fruit.' M. de la Monnoye, himself a Burgundian, has rendered this passage somewhat differently in an edition published the same year at Dijon: 'Jusqu'aux cieux le Champagne élève De son vin pétillant la riante liqueur, On sait qu'il brille aux yeux, qu'il chatouille le c[oe]ur, Qu'il pique l'odorat d'une agréable sève. Mais craignons un poison couvert, L'aspic est sous les fleurs, que seulement par grâce; Quand Beaune aura primé, Reims occupant la place, Vienne légèrement amuser le dessert.' ] [Footnote 148: _Campania vindicata; sive laus vini Remensis a poeta Burgundo eleganter quidam, sed immerito culpati._ Offerebat civitati Remensi Carolus Coffin. Anno Domini /MDCCXII/.] [Footnote 149: 'Quantum superbas vitis, humi licet Prorepat, anteit fructibus arbores Tantum, orbe quæ toto premuntur Vina super generosiora Remense surgit. Cedite, Massica Cantata Flacco Silleriis; neque Chio remixtum certet audax Collibus Aïacis Falernum. Cernis micanti concolor ut vitro Latex in auras, gemmeus aspici, Scintellet exultim; utque dulces Naribus illecebras propinet. Succi latentis proditor halitus Ut spuma motu lactea turbido Crystallinum lætis referre Mox oculis properet nitorem.' La Monnoye renders this as follows: 'Autant que, sans porter sa tête dans les cieux, La vigne par son fruit est au-dessus du chêne; Autant, sans affecter une gloire trop vaine, Reims surpasse les vins les plus délicieux. Qu'Horace du Falerne entonne les louanges Que de son vieux Massique il vante les attraits; Tous ces vins fameux n'égaleront jamais Du charmant Silleri les heureux vendanges. Aussi pur que la verre ou la main l'a versé, Les yeux les plus perçants l'en distinguent à peine; Qu'il est doux de sentir l'ambre de son haleine Et de prévoir le goût par l'odeur annoncé, D'abord à petits bonds une mousse argentine Etincelle, petille et bout de toutes parts, Un éclat plus tranquille offre ensuite aux regards D'un liquide miroir la glace cristalline.' ] [Footnote 150: 'Non hæc malignus quidlibet obstrepat Livor; nocentes dissimulant dolos Leni veneno. Vina certant Inguenuos retinere Gentis Campana mores. Non stomacho movent Ægro tumultum; non gravidum caput Fulagine infestant opacâ.' Bellechaume renders these lines in the Recueil as follows: 'Il n'a point, quoiqu'on insinue De poison parmi ses douceurs, Et de sa province ingénue La Champagne a gardé les m[oe]urs. Il n'excite point de tempête Dans les estomacs languissants; Son feu léger monte à la tête, Eveille et réjouit les sens.' La Monnoye gives them thus: 'Taisez-vous envieux dont la langue cruelle Veut qu'ici sous les fleurs se cache le venin; Connaissez la Champagne, et respectez un vin Qui des m[oe]urs du climat est l'image fidèle. Non, ce jus qu'à grand tort vous osez outrager De images fâcheux ne trouble point la tête, Jamais dans l'estomac n'excite de tempête; Il est tendre, il est net, délicat et léger.' ] [Footnote 151: 'Ergo ut secundis (parcere nam decet Karo liquori) se comitem addidit Mensis renidens Testa; frontem, Arbitra lætitiæ, resolvit Austeriorum. Tune cyathos juvat Siccare molles: tunc hilaris jocos Conviva fundit liberales; Tunc procul alterius valere.' Bellechaume has rendered this: 'Sitôt que sur de riches tables De ce nectar avec le fruit On sert les coupes délectables, De joie il s'élève un doux bruit; On voit, même sur le visage Du plus sévère et du plus sage, Un air joyeux et plus serein: Le ris, l'entretien se reveille; Il n'est plus de liqueur pareille A cet élixir souverain.' La Monnoye's version is as follows: 'Vers la fin du repas, à l'approche du fruit, (Car on doit ménager une liqueur si fine), Aussitôt que parait la bouteille divine, Des Grâces à l'instant l'aimable ch[oe]ur la suit Parmi les conviés, s'élève un doux murmure; Le plus stoïque alors se deride le front.' ] [Footnote 152: That of Utrecht, concluded the following year, 1713.] [Footnote 153: _Ad clarissimum virum Guidonem-Crescentium Fagon regi a secretoribus consiliis, archiatrorum comitem; ut suam Burgundo vino prestantiam adversus Campanum vinum asserat._] [Footnote 154: The original lines and the translation, published by Bellechaume the same year in his _Recueil_, prove, as do the extracts already quoted from Coffin, that a sparkling wine was meant. The former run thus-- 'Hinc inversa scyphis tumet, fremitque; Spumasque agglomerat furore mixtas Æstuans, levis, inquies proterva;' Bellechaume's translation is as above-- 'Enflés du même orgueil tous ses vins bondissants N'élèvent que des flots écumeux frémissants Leur liqueur furieuse, inconstante et légère Etincelle, petille, et bout dans la fougère.' ] [Footnote 155: These epigrams and their translation are given anonymously, as follows, in Bellechaume's _Recueil_: 'Quid medicos testa implores Burgunda? Laboras Nemo velit medicam poscere sanus opem. Cur fugis ad doctum, Burgundica testa, Fagonem? Arte valet multa, sed nimis ægra jaces.' 'A ce que je me persuade Sur la qualité des bons vins, Grenan, ta cause est bien malade, Tu consultes les médecins. Quand on s'adresse au médecin C'est qu'on éprouve une souffrance; Bourgogne, vous n'êtes pas sain Puisqu'il vous faut une ordonnance.' ] [Footnote 156: _Decretum medica apud insulam Coon facultatis super poetica lite Campanum inter et Burgundum vinum ortâ post editum a poeta Burgundo libellum supplicem._ By several writers this poem has been ascribed to Grenan; but M. Philibert Milsaud, in his _Procés poétique touchant les Vins de Bourgogne et de Champagne_ (Paris, 1866), clearly shows that, although in favour of Burgundy, the judgment is an ironical one, and that the signature C. C. R. stands for Carolus Coffin Remensis.] [Footnote 157: _Ode à Messieurs Coffin et Grenan, Professeurs de Belles Lettres, sur leurs Combats poétiques au sujet des Vins de Bourgogne et de Champagne_, in Bellechaume's _Recueil_.] [Footnote 158: 'Pour connaître la différence Du nectar de Beaune et de Reims, Il faut mettre votre science A bien goûter de ces deux vins.' ] [Footnote 159: In an anonymous letter addressed to Grenan on February 1712, and published in the _Recueil_.] [Footnote 160: 'Un franc Bourguignon se fait gloire D'être avec un Remois à boire; Ils sont tous deux bons connaisseurs, Et ne sont pas moins bons buveurs.' ] [Footnote 161: _Les Célébrités du Vin de Champagne._ Epernay, 1880. Maucroix died in his ninetieth year in 1708.] [Footnote 162: Henderson's _History of Ancient and Modern Wines_.] [Footnote 163: In the _Journal des Savants_.] [Footnote 164: 'Vieux Bourguignon, jeune Champagne Font l'agrément de nos festins.' From _La Critique_, an opera of Panard's, produced in 1742. ] [Footnote 165: 'With what vivacity,' he exclaims, with a strange blending of poetry and science, 'does this divine liquid burst forth in sparkling foam-bells! And what an agreeable impression it produces upon the olfactory organs! What a delicious sensation it creates upon the delicate fibres of the palate! ... It is fixed air which, by its impetuous motion, forms and raises up that foam, the whiteness of which, rivalling that of milk, soon offers to our astonished eye the lustre of the most transparent crystal. It is this same air that, by its expansion and the effervescence it produces, develops the action of the vinous spirit of which it is the vehicle, in order that the _papillæ_ of the nerves may more promptly receive the delicious impression.... Vainly calumny spreads the report on all sides that the sparkle of our wines is injurious; vainly it asserts that they have only a hurtful fire and a worthless flavour. Incapable of hiding under an insidious appearance a perfidious venom, they will always present a faithful image of the ingenuousness of their native province.'] [Footnote 166: Max Sutaine's _Essai sur le Vin de Champagne_.] [Footnote 167: Henderson's _History of Ancient and Modern Wines_. Pluche, in his _Spectacle de la Nature_, notices the controversy regarding the respective merits of the wines of the Marne and the Côte d'Or in the following terms: _'Count_: If we will be determined by the finest palates, the Champaign wine is much preferable to Burgundy. _Prior_: It is a sufficient honour for Champaign to be admitted to the same degree of estimation with Burgundy; and it may very well dispense with the priority. I always thought Burgundy had some similitude with a solid understanding, which affects us with lasting impressions, and that Champaign resembles a lively wit, which glitters more upon the imagination, but which is not always serviceable to its possessor. _Count_: If you had made the froth of some Champaign wines and the sallies of a sprightly wit your parallel, I should have thought it unexceptionable; and several pleasant remarks might be made on this sprightliness without solidity. But such a Champaign wine as that of Sillery unites all the vigour of Burgundy, with an agreeable flavour peculiar to itself. _Prior_: I prefer useful qualities to those that are merely agreeable. Burgundy seems to be a more salutary wine than Champaign, and will always be triumphant for that reason. Its colour alone declares it to be a wine of a good body, and I must confess I am apt to be diffident of all dazzling appearances. _Count_: People believe that this deep colour, so esteemed in Burgundy wines, is an indication of their wholesomeness; but it is observable in the grossest wines, and results from an intermixture of the husky parts of the grape. Wine, in proportion to the quantity of these particles blended with it, will be less qualified for digestion. The gout, therefore, and the stone, with which the inhabitants of wine-countries are so frequently afflicted, are distempers hardly known either at Reims or on the banks of the Marne, where the wines are very moderately coloured.... Wines may be made almost as white in Burgundy as they are in Champaign, though not so good; and, on the other hand, the Champenois press a wine as red as the Burgundy growth, and the merchants sell it either as the best species of Burgundy to the wine-conners, who are the first people that are deceived in it, or as red Champaign to the connoisseurs, who prefer it to any other wine. If we may judge of the merit of wines by the price, we shall certainly assign the preference to Champaign, since the finest species of this wine is sold in the vaults of Sillery and Epernai for six, seven, or eight hundred livres, when the same quality of the best Burgundy may be purchased for three hundred. _Countess_: Let me entreat you, gentlemen, to leave this controversy undecided. The equal pretensions that are formed by these two great provinces promote an emulation which is advantageous to us. The partisans for Burgundy and Champaign form two factions in the State; but their contests are very entertaining, and their encounters not at all dangerous. It is very usual to see the zealots of one party maintaining a correspondence with those of the other; they frequently associate together without any reserve, and those who were advocates for Burgundy at the beginning of the entertainment are generally reconciled to Champaign before the appearance of the dessert.'] [Footnote 168: _Letters, &c._ Hamburg and Paris, 1788. The translator adds, as a note, 'People do not any longer get drunk on Champagne.'] [Footnote 169: _Mémoires du Duc de St. Simon._] [Footnote 170: _Journal de Barbier._] [Footnote 171: A curious proof of the popularity of sparkling Champagne, and of the singular system of provincial government into which France was broken up during the reign of Louis XV., is found in a decree of the Council of State, dated May 25, 1728. The decree in question begins by setting forth that, by the _Ordonnance des aides de Normandie_, wine was forbidden to be brought into Rouen or its suburbs in bottles, jugs, or any less vessels than hogsheads and barrels--with the exception of _vin de liqueur_ packed in boxes--under pain of confiscation and one hundred livres' fine, and that carriers were prohibited from conveying wine in bottles in the province without leave from the _fermier des aides_. Nevertheless, petitions had been presented by the _maire_ and _échevins_ of Reims, stating 'that the trade in the gray wines of Champagne had considerably increased for some years past, through the precautions taken at the place of production to bottle them during the first moon of the month of March following the vintage, in order to render them _mousseux_; that those who make use of the gray wine of Champagne prefer that which is _mousseux_ to that which is not; and that this gray wine cannot be transported in casks into the interior of the kingdom or to foreign countries without totally losing its qualities,'--a statement probably intentionally overdrawn, since Bertin du Rocheret used to export it in casks to England. Yet the _fermiers des aides de Normandie_ claimed to prohibit the transport of wines in bottle; and if their pretension held good, the trade in the gray wine of Champagne would be destroyed. 'Shifting the cause, as a lawyer knows how,' the decree recapitulates the plea of the _fermiers_ that the transport of wine in bottles offered facilities for defrauding the revenue, since a carrier with a load could easily leave some of it _en route_ with innkeepers, and these in turn could hide bottles holding a _pinte de Paris_ from the officers in chests, cupboards, &c., and sell them subsequently, to the detriment of the _droits de détail_. The foregoing duly rehearsed, there follows the decree permitting 'to be sent in bottles into the province of Normandy, for the consumption of the said province, gray wine of Champagne in baskets, which must not hold less than one hundred bottles,' but prohibiting the introduction in bottles of any other growth or quality, under the penalty of confiscation and one hundred livres' fine. Permission is also given to pass gray and red wine of Champagne, or of any other _cru_ or quality, in baskets of fifty or one hundred bottles for conveyance into other provinces, or for shipment to foreign parts by the ports of Rouen, Caen, Dieppe, and Havre. The wagoners, however, in all cases are to have certificates signed and countersigned by all manner of authorities, and are only to enter the province by certain specified routes. All wine, too, is to pay the _droit de détail_, except in the case of people not continuously residing in the province, who may be going to their estates, or those bound for the eaux de Forges, a celebrated watering-place, both of whom may take a certain quantity in bottle with them for their own consumption free of duty.] [Footnote 172: 'To be drunk as _nouveau_ or bottled,' says M. Louis Perrier in his _Mémoire sur le Vin de Champagne_.] [Footnote 173: D'Argenson's _Mémoires_.] [Footnote 174: Bois-Jourdain's _Mélanges Historiques_. The editor of the _Journal de Barbier_ observes in a note to a passage referring to the King's suppers at La Muette with Madame de Mailly, under the date of November 1737: 'These suppers were drinking bouts. It was there that the King acquired a taste for Champagne.'] [Footnote 175: Clauteau's _Relation de ce qui s'est passé au Passage du Roi_. Reims, 1744.] [Footnote 176: Ibid.] [Footnote 177: Varin's _Archives Administratives de Reims_.] [Footnote 178: Louis Paris' _Histoire de l'Abbaye d'Avenay_.] [Footnote 179: Amongst these may be cited the Abbé Bignon, who, in a letter to Bertin du Rocheret dated January 1734, says: 'The less the wine is _mousseux_ and glittering, and the more, on the contrary, it shows at the outset of what you style _liqueur_, and I, in chemical terms, should rather call balsamic parts, the better I shall think of it.'] [Footnote 180: Louis Perrier's _Mémoire sur le Vin de Champagne_.] [Footnote 181: 'Chloris, Eglé me versent de leur main D'un vin d'Ay dont la mousse pressée, De la bouteille avec force élancée, Comme un éclair fait voler son bouchon. Il part, on rit; il frappe le plafond: De ce vin frais l'écume pétillante De nos Français est l'image brillante.' ] [Footnote 182: 'De ce vin blanc délicieux Qui mousse et brille dans le verre, Dont les mortels ne boivent guères; Et qu'on ne sert jamais qu'à la table des dieux Ou des grands, pour en parler mieux, Qui sont les seuls dieux de la terre.' ] [Footnote 183: Desaulx, a canon of Reims Cathedral, rendered Lebatteux's ode as follows: 'Ce n'est point sur les monts de Rhodope et de Thrace Que j'irai t'invoquer; ces monts couverts de glace, Sont-ils propres à tes faveurs? Non, Reims te voit régner bien plus sur ses collines; Là je t'offre mes v[oe]ux; de nos côtes voisines Embrases moi de tes ardeurs. Soit que d'un lait mousseux l'écume pétillante, Soit qu'un rouge vermeil, par sa couleur brillante, T'annonce à mes regards surpris, Viens, anime mes vers; ma muse impatiente Veut devoir en ce jour les accords qu'elle enfante A la force de tes esprits.' ] [Footnote 184: 'Non, telles gens ne boivent pas De cette sève délectable, L'âme et l'amour de nos repas, Aussi bienfaisante qu'aimable. Leur palais corrompu, gâté, Ne veut que du vin frelaté, De ce poison vert, apprêté, Pour des cervelles frénétiques. Si, tenons-nous pour hérétiques Ceux qui rejettent la bonté De ces _corpusculs balsamiques_ Que jadis Horace a chantés. Non, telles gens ne boivent pas De cette sève délectable, L'âme et l'honneur de nos repas, Aussi bienfaisante qu'aimable. De ce vin blanc délicieux, Qui désarme la plus sévère; Qui pétille dans vos beaux yeux Mieux qu'il ne brille dans mon verre. Buvons, buvons à qui mieux mieux, Je vous livre une douce guerre; Buvons, buvons de ce vin vieux, De ce nectar délicieux, Qui pétille dans vos beaux yeux Mieux qu'il ne brille dans mon verre.' The above was set to music by M. Dormel, organist of St. Geneviève.] [Footnote 185: Marmontel's _Mémoires d'un Père pour l'instruction de ses Enfants_. M. Louis Paris, in his _Histoire de l'Abbaye d'Avenay_, identifies this spot as one known indifferently as Le Fay or Feuilly. He furnishes some interesting details respecting Mademoiselle de Navarre, who, after being the mistress of Marshal Saxe, married the Chevalier de Mirabeau, brother to the _Ami des Hommes_ and uncle of the celebrated orator, and then goes on to say: 'In the seventeenth and eighteenth centuries the wines of Avenay shared with those of Hautvillers the glory of rivalling the best of Ay. "_Avenay, les bons raisins_," was the popular saying inscribed on the banner of its _chevaliers de l'Arquebuse_ (a corps of local sharpshooters). La Bruyère, St. Evremond, Boileau himself, Coulanges, L'Atteignant, and many others had celebrated the tender and delicate wines of our vineyards; and that of Madame l'Abbesse especially had acquired such a reputation, that several great families, strangers to the locality, thought it the right thing to have a _vendangeoir_ at Avenay, and to pass part of the autumn in the renowned Val d'Or.'] [Footnote 186: 'Vois ce nectar charmant Sauter sous ces beaux doigts; Et partir à l'instant; Je crois bien que l'amour en ferait tout autant. Et quoi sous ces beaux doigts Bouchon a donc sauté pour la première fois? Croyez-vous que l'amour Leur fit un pareil tour?' ] [Footnote 187: 'Le jus que verse Ganimède A Jupiter dans ses repas A ce vin de Champagne cède, Et nous sommes mieux ici bas.' From the edition of his _Poesies_ published in 1757. ] [Footnote 188: 'Et quand je décoiffe un flacon Le liège qui pette Me fait entendre un plus beau son Que tambour et trompette.' Panard's _[OE]uvres_, Paris, 1763. ] [Footnote 189: 'Diaphorus au marchand de vin Vend bien cher un extrait de rivière; Le marchand vend au médecin Du Champagne arrivé de Nanterre, Ce qui prouve encor ce refrain-ci A trompeur, trompeur et demi.' ] [Footnote 190: 'Pour jouir d'un destin plus tranquille et plus doux De ce bruyant séjour, amis, éloignons nous, Allons, dans mon cellier, du Champagne et du Beaune Goûter les doux appas. Les plaisirs n'y sont pas troublés par l'embarras, Et le funeste ennui qui monte jusqu'au trône Dans les caveaux ne descend pas.' ] [Footnote 191: 'C'est alors qu'un joyeux convive, Saississant un flacon scellé, Qui de Reims ou d'Ai tient la liqueur captive, Fait sauter jusqu'à la solive Le liège deficellé; Tout le cercle attentif porte un regard avide Sur cet objet qui les ravit; Ils présentent leur verre vide, Le nectar pétillant aussitôt les remplit. On boit, on goûte, on applaudit, On redouble et par l'assemblée La mousse Champenoise à plein verre est sablée. De là naissent les ris, les transports éclatans, La sève et tout son feu, jusqu'au cerveau montants, Font naître des débats, des querelles polies Qui réveillent l'esprit de tous les assistants.' ] [Footnote 192: An allusion to the _vin gris_ of the Champagne.] [Footnote 193: 'Grâce à la liqueur Qui lave mon c[oe]ur, Nul souci ne me consume. De ce vin gris Que je chéris L'écume, Lorsque j'en boi Quel feu chez moi S'allume! Nectar enchanteur, Tu fais mon bonheur; Viens, mon cher ami! Que j't'hume! Champagne divin, Du plus noir chagrin Tu dissipes l'amertume. Tu sais mûrir, Tu sais guérir Le rhume. Quel goût flatteur Ta douce odeur Parfume! Pour tant de bienfaits Et pour tant d'attraits; Viens, mon cher ami! Que j't'hume!' ] [Footnote 194: Max Sutaine's _Essai sur le Vin de Champagne_.] [Footnote 195: M. Sutaine observes that in 1780 a merchant of Epernay bottled 6000 bottles, and that the importance of this _tirage_ was noted as something remarkable; and this statement has been repeated by every other writer on Champagne. Yet here is a _tirage_ of 6000 bottles taking place thirty-four years previously. The extent of the bottled-wine trade is confirmed by Arthur Young, who in 1787 visited Ay, where M. Lasnier had 60,000 bottles in his cellar, and M. Dorsé from 30,000 to 40,000. Marmontel in 1716 mentions Henin de Navarre's cellars at Avenay as containing 50,000 bottles of Champagne.] [Footnote 196: E. J. Maumené's _Traité du Travail des Vins_, 1874.] [Footnote 197: Ibid. The _casse_ of 1776 has never been forgotten at Epernay; and M. Perrier, in a letter of August 1801, mentions a recent one at Avize amounting to 85 per cent. That of 1842 flooded the cellars throughout the Champagne. Even in 1850 M. Maumené mentions a _casse_ in a Reims cellar which had reached 98 per cent at his visit, and was still continuing.] [Footnote 198: Max Sutaine's _Essai sur le Vin de Champagne_. The Abbé Bignon confirms this in a letter of December 20, 1736, to Bertin du Rocheret, respecting wine received from him. 'The wine sealed with a cipher in red wax,' he observes, 'seemed to me very delicate, but having as yet some _liqueur_ which time may get rid of, though after that I am afraid there will not remain much strength. Another, also sealed with red wax, but with a coat-of-arms, seems to have more quality and vinosity, though also very delicate and very light, both _sablant_ perfectly, though they cannot be called _mousseux_. As to that which is sealed with black, the people who esteem foam would bestow the most magnificent eulogies upon it. It would be difficult to find any that carries this beautiful perfection further. Three spoonfuls at the bottom of the glass is surmounted with the strongest foam to the very brim; on the other hand, I found in it a furious _vert_, and not much vinosity.'] [Footnote 199: In 1734 he speaks of his _mousseux sablant_, and forwards to the Marquis de Polignac both _mousseux_ and _petillant_. In 1736 he offers M. Véron de Bussy his choice of _demi-mousseux_, _bon mousseux_, and _saute bouchon_; and the following year distinguishes his Ay _mousseux_ from his _saute bouchon_.] [Footnote 200: Respecting the price of sparkling Champagne during the first half of the eighteenth century, a few instances from the correspondence of Bertin du Rocheret may here he quoted. In 1716 he offers Marshal d'Artagnan 1500 bottles at 35 sols, cash down, and taken at Epernay. In 1725 he offers _flacons blancs mousseux liqueur_ at from 30 to 50 sols, and _ambrés non mousseux, sablant_, at 25 sols. Ten years later _saute bouchon_ is quoted by him at 40 and 45 sols, and in 1736 at 3 livres, _demi-mousseux_ ranging from 36 to 40 sols, and _bon mousseux_ from 45 to 50 sols. The following year _saute bouchon_ fetched 3 livres 6 sols, and _mousseux_ 42 sols. In 1736 he insisted upon his _flacons_ holding a _pinte_; and a royal decree of March 8, 1755, which regulated the weight and capacity of sparkling-wine bottles, required these to weigh 25 ounces, and to hold a _pinte de Paris_, or about 1.64 imperial pint. They were, moreover, to be tied crosswise on the top of the cork, with a string of three strands well twisted. Their cost was 15 livres per hundred in 1734 and 1738, and from 17 to 19 livres in 1754.] [Footnote 201: Louis Perrier's _Mémoire sur le Vin de Champagne_.] [Footnote 202: It would appear from Bidet that the wines of the Mountain had not been transformed into _vin mousseux_ as late as 1752, as, in his book on wine published during that year, he only includes in the list of places producing sparkling wine Ay, Avenay, Mareuil, Dizy, Hautvillers, Epernay, Pierry, Cramant, Avize, and Le Mesnil.] [Footnote 203: 'Votre palais, usé, perclus Par liqueur inflammable, Préfère de mousseux verjus Au nectar véritable.' ] [Footnote 204: Louis Perrier's _Mémoire sur le Vin de Champagne_. In the thesis in favour of Champagne, written by Dr. Xavier of Reims in 1777, the acidulous character of the wine is confirmed by the author, who naïvely remarks that it is as efficacious in preventing putrefaction as are other acids. He also compares it to acidulated waters.] [Footnote 205: Legrand d'Aussy's _Vie privée des Français_, 1782.] [Footnote 206: Louis Perrier's _Mémoire sur le Vin de Champagne_. The pretended secret of Dom Perignon, quoted from the _Mémoire_ of 1718, and mentioning the addition of sugar to the wine of Hautvillers, is flatly contradicted by Dom Grossart's letter to M. Dherbès (see page 41 _ante_). But it is probable that the suggestion thus made public was acted upon, though at first only timidly.] [Footnote 207: Chaptal's _Art de faire du Vin_. As Minister of the Interior, he forwarded the results of his experiments to the _préfets_, with the recommendation to spread them throughout their departments.] [Footnote 208: Louis Perrier's _Mémoire sur le Vin de Champagne_.] [Footnote 209: Letter of M. Nicolas Perrier to M. Cadet-Devaux, dated August 1801.] [Footnote 210: As _bourru_, _tocane_, and _en nouveau_.] [Footnote 211: Louis Perrier's _Mémoire sur le Vin de Champagne_.] [Footnote 212: The letter in which he mentions this is extant, but the secret which was enclosed in it is missing.] [Footnote 213: Dom Grossart, who had retired to Montier-en-Der in 1790, was unacquainted with this plan when he wrote to M. Dherbès in 1821, although it had been practised for twenty years past.] [Footnote 214: In a /MS./ quoted in Varin's _Archives Administratives de Reims_.] [Footnote 215: The gifts presented by the municipality on this occasion included flowers, pears, and gingerbread, Reims being as famed for the latter as for its wines. The guild of gingerbread-makers at Reims was established in the sixteenth century, and from that time forward was engaged in continual squabbles with the bakers and pastrycooks of the city, who could not be brought to understand that they had not the right to make gingerbread. Countless reams of paper were scribbled over by the lawyers of the two contending interests; but though the Bailli of Reims on several occasions pronounced a formal verdict, to the effect that no one but a sworn and accepted gingerbread-maker should have act or part in the making of the indigestible delicacy, the contumacious bakers continued to treat his edicts as naught. Eventually a royal edict of 1776, which suppressed the privileges of the majority of the guilds in France, deprived the Reims gingerbread-makers for ever of the right of figuring with swords by their sides and three-cornered hats on their heads at all local ceremonies, civil or religious, and threw their trade open to all. It was at the close of Louis XIV.'s reign that the _pain d'épice_ of Reims reached the summit of its renown. At the coronation of his successor, the _échevins_ of Reims presented the monarch with several baskets of it; and when Maria Leczinska passed through Reims in January 1725, the notables offered her twelve wicker baskets, covered with damask and ornamented with ribbons, containing fresh and dried pears, conserves, preserved lemons, almond-cakes, and a new kind of gingerbread, which received the name of _nonnette à la Reine_.] [Footnote 216: This escutcheon shows the arms of Reims, which at first consisted of _rinçeaux_ or branches; subsequently a cross and a crozier, placed saltire-wise, and a sainte Ampoule, were added. When the government of the city passed from the archbishop, the entwined olive-branches and chief strewn with fleurs de lis were adopted, the old motto, 'Dieu en soit garde,' being retained. The iron gates of the Porte de Paris were removed to their present position in 1843, to allow of the passage of the canal.] [Footnote 217: From the days of Charles VIII. to those of Louis XIV., it was customary on these occasions for the keys to be presented by a young girl styled the Pucelle de Reims; and J. M. C. Leber, in his work _Des Cérémonies du Sacre_, is of opinion that this custom arose in some way from the visit of Joan of Arc. Louis XV. was the first who received them from the lieutenant.] [Footnote 218: Baron Taylor's _Reims, la Ville de Sacres_.] [Footnote 219: N. Menin's _Traité du Sacre et Couronnement des Rois_.] [Footnote 220: P. Tarbé's _Reims, ses Rues et ses Monuments_.] [Footnote 221: H. Taine's _L'Ancien Régime_.] [Footnote 222: Ibid.] [Footnote 223: Arthur Young's _Travels in France in 1787-9_.] [Footnote 224: Ibid. Another grievance alleged against the monasteries was the presence of the innumerable fishponds belonging to them scattered throughout the country. The _Cahier des Plaintes, Doléances, et Remontrances du Tiers Etat du Baillage de Reims_, on the Assembly of the States General under Louis XVI., ask that 'all fishponds situate outside woods and, above all, those which lie close to vineyards, may be suppressed, as hurtful to agriculture.'] [Footnote 225: H. Taine's _L'Ancien Régime_.] [Footnote 226: Instructions of local _directeurs des aides_, quoted from the _Archives Nationales_ by Taine.] [Footnote 227: H. Taine's _L'Ancien Régime_.] [Footnote 228: _Les Célébrités du Vin de Champagne_, Epernay, 1880.] [Footnote 229: H. Taine's _L'Ancien Régime_. At Rethel a poinçon of the _jauge de Reims_ paid 50 to 60 francs for the _droit de détail_ alone.] [Footnote 230: Arthur Young's _Travels in France in 1787-9_.] [Footnote 231: H. Taine's _L'Ancien Régime_.] [Footnote 232: Crebillon the younger's _Les Bijoux Indiscrets_.] [Footnote 233: A /MS./ account of the wine culture of Poligny in the Jura states that in 1774 attempts were made to imitate the gray and pink wines of the Champagne, then selling at 3 livres 10 sous the bottle.] [Footnote 234: Erckmann-Chatrian's _Histoire d'un Paysan_.] [Footnote 235: 'Suppose Champagne flowing,' says Carlyle, when describing this banquet in his _French Revolution_.] [Footnote 236: Carlyle's _French Revolution_.] [Footnote 237: The date 'An 1^{er} de la liberté' may possibly refer to the 'Year One' of the Republican calendar (1792), in which Mirabeau fell in a duel at Fribourg. But an earlier edition of the same caricature seems to have been published, according to De Goncourt in the _Journal de la Mode et du Goût_, in May 1790.] [Footnote 238: 'Malgré les calembours, les brocards, les dictons, Je veux à mes repas vuider mes deux flacons,' are the lines assigned to him in _Le Vicomte de Barjoleau, ou le Souper des Noirs_, a two-act comedy of the epoch.] [Footnote 239: [Illustration: LE GOURMAND: AN INCIDENT OF LOUIS XVI.'S FLIGHT FROM PARIS (From a caricature of the period).] This caricature, which is neither signed nor dated, is simply entitled 'Le Gourmand;' though Jaime, in his _Histoire de la Caricature_, states that it represents Louis XVI. at Varennes. According to Carlyle, however, the king reached Varennes at eleven o'clock at night, was at once arrested in his carriage, and taken to Procureur Sausse's house. Here he 'demands refreshments, as is written; gets bread-and-cheese, with a bottle of Burgundy, and remarks that it is the best Burgundy he ever drunk.' At six o'clock the following morning he left Varennes, escorted by ten thousand National Guards. Very likely there may have been a story current at the time to the effect that the arrest was due to the king's halting to gratify his appetite. Or the caricature may represent some incident that occurred, during his return to Paris, as he passed through the Champagne district, and halted at the Hôtel de Rohan at Epernay.] [Footnote 240: De Goncourt's _Société Française pendant la Révolution_.] [Footnote 241: Ibid.] [Footnote 242: St. Aubin's _Expédition de Don Quichotte_.] [Footnote 243: _Aux voleurs! aux voleurs!_ quoted by De Goncourt.] [Footnote 244: _Lettres du Père Duchêne_, quoted by De Goncourt.] [Footnote 245: _Les Célébrités du Vin de Champagne_, Epernay, 1880.] [Footnote 246: _Journal de ce qui s'est passé d'intéressant à Reims en 1814._] [Footnote 247: Ibid.] [Footnote 248: G. A. Sala's _Paris Herself Again_.] [Footnote 249: Gronow's _Celebrities of London and Paris_, 1865.] [Footnote 250: Gronow's _Reminiscences_, 1862.] [Footnote 251: 'J'aime mieux les Turcs en campagne Que de voir nos vins de Champagne Profanés par des Allemands.' Béranger's _Chansons_. ] [Footnote 252: 'Rôtis sur la haute montagne Tout flamme et miel, le Médéah, Le Mascara, le Milianah Feront pâlir le gai Champagne.' _Poésies_ de J. Boese, de Blidah. ] [Footnote 253: 'Il a conduit Pomponnette Chez Vachette, Dans le cabinet vingt-deux; Et là, même avant la bisque, Il se risque A lui déclarer ses feux. Elle demeure accoudée, Obsédée, Résolue à résister, Inexorable et charmante Dans sa mante, Qu'elle ne veut pas quitter. Un troisième personnage, A la nage Dans un seau d'argent orné, Se soulève sur la hanche, Tête blanche, Cou de glace environné. C'est le Champagne; il susurre: "Chose sûre! Quand mon bouchon partira, Tout à l'heure, cette belle Si rebelle Mollement s'apaisera. Bientôt tu verras, te dis-je, Ce prodige Cesse d'invoquer l'enfer; Ton courroux est trop facile; Imbécile, Arrache mon fil de fer! Car je suis maître Champagne, Qu'accompagne Le délire aux cent couplets; Je dompte les plus sévères. A moi, verres, Coupes, flûtes et cornets!" Aussi dit le vin superbe, Moins acerbe, La femme se sent capter. C'est une cause que gagne Le Champagne; Son bouchon vient de sauter.' _Le Parfait Vigneron_, Paris, 1870.] [Footnote 254: Titi Livii Foro-Juliensis _Vita Henrici Quinti_. The author was a _protégé_ of Duke Humphrey of Gloucester.] [Footnote 255: Francisque Michel's _Histoire du Commerce et de la Navigation à Bordeaux_. It was not till the marriage of Henry III. with Eleanor of Aquitaine that we began to import Guienne wine from Bordeaux.] [Footnote 256: Varin's _Archives Administratives de Reims_.] [Footnote 257: Ibid.] [Footnote 258: Victor Fiévet's _Histoire d'Epernay_.] [Footnote 259: Francisque Michel's _Histoire du Commerce et de la Navigation à Bordeaux_.] [Footnote 260: Published in 1615.] [Footnote 261: That of 1574. Surflet's translation appeared in 1600.] [Footnote 262: Venner's _Via recta ad longam Vitam_, 1628.] [Footnote 263: Writing to Sir Walter Mildmay in 1569, the Earl of Shrewsbury, who had charge of the royal prisoner, complains that his regular allowance of wine duty free is not enough. 'The expenses I have to bear this year on account of the Queen of the Scots are so considerable as to compel me to beg you will kindly consider them. In fact, two butts of wine a month hardly serve for our ordinary use; and besides this, I have to supply what is required by the Princess for her baths and similar uses.'] [Footnote 264: Clarendon's _Memoirs_.] [Footnote 265: Letter of Guy Patin, 1660.] [Footnote 266: Otway's _Soldier's Fortune_, act iv. sc. 1, 1681.] [Footnote 267: Ibid.] [Footnote 268: Redding's _History and Description of Modern Wines_.] [Footnote 269: Otway's _Friendship in Fashion_, 1678.] [Footnote 270: 'Nous parler toujours des vins D'Ay, d'Avenet, et de Reims.' _[OE]uvres de Saint-Evremond._ ] [Footnote 271: 'Perdre le goût de l'huitre et du vin de Champagne Pour revoir la leur d'un débile soleil Et l'humide beauté d'une verte campagne, N'est pas à mon avis un bonheur sans pareil, La faveur de la Marne, hélas, est terminée, Et notre montagne de Reims, Qui fournit tant d'excellens vins, A peu favorisé nostre goût cette année. O triste et pitoyable sort! Faut-il avoir recours aux rives de la Loire, Ou pour le mieux au fameux port, Dont Chapelle nous fait l'histoire! Faut-il se contenter de boire Comme tous les peuples du Nord? Non, non, quelle heureuse nouvelle! Monsieur de Bonrepaus arrive, il est icy, Le Champagne pour lui tousjours se renouvelle, Fuyez, Loire, Bordeaux! fuyez, Cahors, aussy!' _[OE]uvres de Saint-Evremond: Sur la Verdure qu'on met aux cheminées en Angleterre._ In these verses we trace the custom, elsewhere spoken of, of drinking the Marne wines when new. St. Evremond himself, in a passage of his prose works, says that the wines of Ay should not be kept too long, or those of Reims drunk too soon.] [Footnote 272: Sparkling is not used here in the modern sense of effervescing: see page 90.] [Footnote 273: Sir George Etherege's _Man of the Mode, or Sir Fopling Flutter_, act iv. sc. 1, 1676.] [Footnote 274: Otway's _Friendship in Fashion_, act ii. sc. 1, 1678.] [Footnote 275: Etherege's _She wou'd if she cou'd_, act iv. sc. 2, 1668.] [Footnote 276: Sir Charles Sedley's _Mulberry Garden_, act ii. sc. 2, 1668.] [Footnote 277: Otway's _Friendship in Fashion_, act i. sc. 1, 1678.] [Footnote 278: Shadwell's _Virtuoso_, act ii. sc. 2, 1676.] [Footnote 279: By Dr. Charleton, and published as late as 1692.] [Footnote 280: Oldham's _Paraphrases from Horace_, book i. ode xxxi., 1684.] [Footnote 281: Oldham's _Works_, &c., 1684.] [Footnote 282: Butler's _Hudibras_, part ii. canto i., 1664. Stum is unfermented wine; and the term brisk applied to Champagne is here employed not to denote effervescence, but to indicate the contrast between the thick immature fluid and the clear carefully-made wines of the Champagne.] [Footnote 283: Butler's _Hudibras_, part iii. canto iii., 1678.] [Footnote 284: Sedley's _The Doctor and his Patients_. No date, but Sedley died in 1701.] [Footnote 285: Thomson's Poems.] [Footnote 286: Cyrus Redding's evidence before the Parliamentary Committee on the Wine-Duties, 1851.] [Footnote 287: Redding's _French Wines_.] [Footnote 288: Varin's _Archives Administratives de Reims_.] [Footnote 289: Louis Perrier's _Mémoire sur le Vin de Champagne_.] [Footnote 290: St. Simon's _Mémoires_.] [Footnote 291: Redding's _French Wines_.] [Footnote 292: Farquhar's _Love and a Bottle_, act ii. sc. 2, 1698.] [Footnote 293: An evident allusion to its effervescence; whilst the words 'straw doublet' most likely refer to the covering of the flask.] [Footnote 294: Cibber's _Love makes a Man_, act i. sc. 1, 1700.] [Footnote 295: Farquhar's _The Inconstant, or the Way to win Him_, act i. scene 2, 1703.] [Footnote 296: Epilogue to the _Constant Couple, or a Trip to the Jubilee_ of Farquhar, spoken by Wilks in 1700. Locket's tavern, which stood on the site now occupied by Drummond's bank at Charing Cross, was especially famous for its Champagne. In the _Quack Vintners_, a satire against Brooke and Hilliers, published in 1712, we read: 'May Locket still his ancient fame maintain For Ortland dainties and for rich Champaign, Where new-made lords their native clay refine, And into noble blood turn noble wine.' ] [Footnote 297: Farquhar's _Twin Rivals_, act v. sc. 1, 1705.] [Footnote 298: Several other writers, who speak of 'bottles' of other wines, use the word 'flask' when referring to Champagne.] [Footnote 299: Farquhar's _Beaux' Stratagem_, act iii. sc. 3, 1706.] [Footnote 300: _Memoir_, prefixed to Leigh Hunt's edition of Congreve's works.] [Footnote 301: Cunninghame's _History of Britain from the Revolution to the Hanover Succession_.] [Footnote 302: Farquhar's _The Constant Couple, or a Trip to the Jubilee_, act v. sc. 1, 1700. M. Francisque Michel, in his _Histoire du Commerce et de la Navigation à Bordeaux_, clearly establishes that from the beginning to the middle of the eighteenth century all the best growths of the Médoc were bought and shipped for England. It was not until after 1755 that any went to Paris.] [Footnote 303: 'Vos, ô Britanni (f[oe]dera nam sinunt Inc[oe]pta pacis) dissociabilem Tranate pontum. Quid cruento Perdere opes juvat usque Marte. Lætis Remensam quam satius fuit Stipare Bacchum navibus; et domum Anferre funestis trophæis Exuvias pretiosiores!' Coffin's _Campania vindicata_, 1712. The force of the reference to England is better understood when it is mentioned that no other nation is alluded to as purchasing the wines of the Champagne.] [Footnote 304: A practice not lost sight of at a later date, to judge from Borachio's observation, 'I turn Alicant into Burgundy and sour cider into Champagne of the first growth of France.' Jephson's _Two Strings to your Bow_, act i. sc. 2.] [Footnote 305: _The Tatler_, No. 131, Feb. 9, 1709.] [Footnote 306: Mrs. Centlivre's _A Bold Stroke for a Wife_, act v. sc. 1, 1718.] [Footnote 307: Gay's poem _On Wine_, published in 1708.] [Footnote 308: Gay's _Welcome from Greece_.] [Footnote 309: Prior's _Alma, or the Progress of the Mind_.] [Footnote 310: Prior's _Alma, or the Progress of the Mind_.] [Footnote 311: Prior's _Bibo and Charon_.] [Footnote 312: Shenstone's _Verses written at a Tavern at Henley_.] [Footnote 313: Vanbrugh's _Journey to London_, act i. sc. 2. Left unfinished at his death in 1726.] [Footnote 314: Swift's _Journal to Stella_, March 12, 1712-13.] [Footnote 315: Ibid. Feb. 20, 1712-13.] [Footnote 316: Ibid. April 9, 1711.] [Footnote 317: Ibid. March 18, 1710.] [Footnote 318: Ibid. March 29, 1711-12.] [Footnote 319: Ibid. Dec. 21, 1711.] [Footnote 320: Ibid. April 7, 1711.] [Footnote 321: Letter to Mr. Congreve, April 7, 1715.] [Footnote 322: Mrs. Centlivre's _A Bold Stroke for a Wife_, act i. sc. 1, 1718.] [Footnote 323: Fielding's _The Miser_, 1732.] [Footnote 324: _The Rake's Progress, or the Humours of Drury Lane_: a poem published in 1735, to accompany a set of prints pirated from Hogarth's.] [Footnote 325: Blunt's _Geneva_: a poem dedicated to Sir R. Walpole, 1729.] [Footnote 326: Hoadley's _Suspicious Husband_, act iv. sc. 1, 1747.] [Footnote 327: This wine, though sometimes sent by way of Dunkirk, was usually forwarded _viâ_ Calais, by the intermediary of a Sieur Labertauche, a commission-agent at that port, the cost of transport from Epernay to Calais being from 70 to 75 livres per queue. A _bobillon_ of wine was sent with each lot of casks for filling up. Moreover, from 1731 Bertin annually despatches a certain quantity of cream of tartar, destined to cure the ropiness to which all white wines were especially subject before the discovery that tannin destroys the principle engendering this disease.] [Footnote 328: Chabane appears to have been fully cognisant of the method of _collage_ and _soutirage_ (fining and racking) practised in the Champagne; and Bertin, in one of his letters dated July 1752, mentions the enclosure of a receipt for a kind of _collage_, by following which all necessity to _dépoter_ the bottles is obviated. This enclosure is unfortunately lost.] [Footnote 329: Ms. correspondence of Bertin du Rocheret, quoted by M. Louis Perrier in his _Mémoire sur le Vin de Champagne_. M. Perrier states that the prohibition was removed by an act of the 1st Nov. 1745; and a letter of Bertin to Chabane, the following year, bears this out. It is therefore singular to find the following entry in Bubb Doddington's _Diary_, under the date of Feb. 1, 1753: 'Went to the House to vote for liberty to import Champaign in bottles. Lord Hillsborough moved it; Mr. Fox seconded it. We lost the Motion. Ayes, 74; Noes, 141.'] [Footnote 330: Letter to Sir Horace Mann, June 18, 1751.] [Footnote 331: Jesse's _Selwyn and his Contemporaries_. It is very probable that the name printed as Prissieux is really Puissieux, a title of the Sillery family.] [Footnote 332: Lady Mary Wortley Montague's _Letter from Arthur Grey, the Footman, to Mrs. Murray_. Written in the autumn of 1721.] [Footnote 333: Lady M. W. Montague's _The Lover_. This is generally designated 'a ballad to Mr. Congreve,' but is headed in Lady Mary's note-book, 'To Molly,' and, as Mr. Moy Thomas has suggested, was probably addressed to Lord Hervey, Pope's 'Lord Fanny.'] [Footnote 334: Note to his _Letter on Bowles_.] [Footnote 335: _Westminster Magazine_, 1774.] [Footnote 336: Grainger's _The Sugar Cane_, 1764.] [Footnote 337: Coleman and Garrick's _Clandestine Marriage_, act i. sc. 2, 1766.] [Footnote 338: Garrick's _Bon Ton, or High Life above Stairs_, act i. sc. 2, 1775.] [Footnote 339: Ibid.] [Footnote 340: Ibid. act ii. sc. 1.] [Footnote 341: Townley's _High Life below Stairs_, act ii. sc. 1, 1759.] [Footnote 342: So in Mrs. Cowley's _Which is the Man?_ Burgundy is extolled and 'vile Port' denounced; and in Cumberland's _The Fashionable Lover_ (1772) a sneer is levelled at a 'paltry Port-drinking club.' Burgundy, too, is in favour in Holcroft's _The Road to Ruin_, 1792.] [Footnote 343: Foote's _The Lame Lover_, act iii. sc. 1, 1770.] [Footnote 344: Garrick's _The Country Girl_, act v. sc. 1.] [Footnote 345: Foote's _The Fair Maid of Bath_, act i. sc. 1, 1771.] [Footnote 346: Holcroft's _The Road to Ruin_, act iv. sc. 2, 1792.] [Footnote 347: Sir Edward Barry's _Observations, Historical, Critical, and Medical, on the Wines of the Ancients, and the analogy between them and Modern Wines_, 1775.] [Footnote 348: Tickell's _Poems_.] [Footnote 349: Timbs' _Clubs and Club Life_.] [Footnote 350: In the _Encyclopédie Méthodique_.] [Footnote 351: Arthur Young's _Travels in France in the Years 1787-9_.] [Footnote 352: Sheen's _Wine and other fermented Liquors_.] [Footnote 353: Amongst other English customers of the firm in 1788, 1789, and 1790 were 'Milords' Farnham and Findlater, the latter of whom was supplied with 120 bottles of the vintage of 1788; Manning, of the St. Alban's Tavern, London, who ordered 130 bottles of vin de Champagne, at 3 livres or 2_s._ the bottle, to be delivered in the autumn by M. Caurette; Messrs. Felix Calvert & Sylvin, who took two sample bottles at 5_s._; and Mr. Lockhart, banker, of 36 Pall Mall, who in 1790 paid 3_s._ per bottle for 360 bottles of the vintage of 1788. The high rate of exchange in our favour is shown by the 54_l._ covering this transaction being taken as 1495 livres 7 sols 9 deniers, or about 28 livres per pound sterling.] [Footnote 354: Walker's _The Original_.] [Footnote 355: 'The Fair of Britain's Isle' (_Convivial Songster_, 1807).] [Footnote 356: _Diary of Mrs. Colonel St. George, written during her Sojourn amongst the German Courts in 1799 and 1800._] [Footnote 357: Moore's _The Twopenny Post-bag_, 1813.] [Footnote 358: Moore's _Parody of a Celebrated Letter_.] [Footnote 359: The compound known as 'the Regent's Punch' was made out of 3 bottles of Champagne, 2 of Madeira, 1 of hock, 1 of curaçoa, 1 quart of brandy, 1 pint of rum, and 2 bottles of seltzer-water, flavoured with 4 lbs. bloom raisins, Seville oranges, lemons, white sugar-candy, and diluted with iced green tea instead of water (Tovey's _British and Foreign Spirits_).] [Footnote 360: Captain Gronow's _Reminiscences_.] [Footnote 361: Ibid.] [Footnote 362: Prince Puckler Muskau's _Letters_.] [Footnote 363: Miss Burney's _Memoirs_.] [Footnote 364: Henderson's _History of Ancient and Modern Wines_, 1824. Henderson, who appears to have visited the Champagne in 1822, remarks of the remaining _crûs_ of the province: 'The wines of the neighbouring territories of Mareuil and Dizy are of similar quality to those of Ay, and are often sold as such. Those of Hautvillers, on the other hand, which formerly equalled, if not surpassed, the growths just named, have been declining in repute since the suppression of the monastery, to which the principal vineyard belonged.'] [Footnote 365: Moore's _The Fudge Family Abroad_, 1818.] [Footnote 366: Moore's _The Sceptic_.] [Footnote 367: Moore's _Illustration of a Bore_.] [Footnote 368: Moore's _The Summer Fête_, 1831.] [Footnote 369: Ibid.] [Footnote 370: Ibid.] [Footnote 371: Moore's _Diary_, June 1819.] [Footnote 372: Lockhart's _Life of Sir Walter Scott_.] [Footnote 373: Scott's _Diary_, November 15, 1826.] [Footnote 374: Byron's _English Bards and Scotch Reviewers_, 1808.] [Footnote 375: Byron's _Don Juan_, canto xv. stanza lxv., 1821.] [Footnote 376: Ibid. canto xvi. stanza ix.] [Footnote 377: Ibid. canto xiii. stanzas xxxvii., xxxviii.] [Footnote 378: According to recent statistics issued by the Chamber of Commerce of Reims, the department of the Marne contains 16,500 hectares of vineyards (40,755 acres), of which 2465 hectares are situated in the district of Vitry-le-François; 555 hectares in that of Châlons; 700 in that of Sainte Menehould; 7624 in that of Reims; and 5587 in the Epernay district, where the finest qualities of Champagne are grown. The value of the wine produced annually in these districts exceeds 60,000,000 francs (nearly 2-1/2 millions sterling). During the last thirty years, the value of these vineyards has increased fourfold. The 'population vigneronne' of the department is 16,093 inhabitants.] [Footnote 379: In the year 1871.] [Footnote 380: The blending of black and white grapes together, although its advantages had been recognised in the _Maison Rustique_ of 1574, appears not to have been successfully carried out at Ay till the days of Dom Perignon. 'Formerly,' remarks Pluche, 'it was very difficult to preserve the wine of Ay longer than one year. When the juice of the white grapes, whose quantity was very great in that vineyard, began to assume a yellowish hue, it became predominant, and created a change in all the wine; but ever since the white grapes have been disused, the Marne wines may be easily kept for the space of four or five years' (_Spectacle de la Nature_, 1732).] [Footnote 381: From time immemorial the vineyards of Ay and Dizy paid tithes to the Abbey of Hautvillers, the former a sixtieth and the latter an eleventh of their produce. These dues were, by a decree of 1670, levied at the gate of Ay. In 1772, Tirant de Flavigny, a large wine-grower, who farmed, amongst other vineyards, 'Les Quartiers' at Hautvillers, insisted on leaving the tithe of grapes at the foot of the vine for collection by the abbey tithe-collectors. The Abbot Alexandre Ange de Talleyrand Périgord refused to accept them, and insisted in turn that the whole of the grapes should either be brought to the gate of Hautvillers or converted into wine in the vineyard, and the eleventh part of this wine handed to his representative. From a _procès verbal_ drawn up by the Mayor of Ay, it seems that the inhabitants were willing to pay a monetary commutation, as was the prevailing custom, or to leave the abbot's share of grapes in the vineyards; but objected to the tithe being taken, usually with considerable delay, on each basket, whereby the remaining grapes were bruised, and the possibility of bright white wine being made from them rendered exceedingly doubtful. It was not till 1787 that it was finally settled that the tithes should be paid in money at the rate of so much per arpent, and it is plain that the abbot's chief object was to throw as much difficulty as he could in the way of rival makers of fine wines.] [Footnote 382: This curse is alluded to in the following verse from a sixteenth-century ballad written against the men of Ay: 'Tu n'auras ni chien ni chat Pour te chanter _Libera_, Et tu mourras mau-chrétien, Toi qu'a maudit Saint Trézain.' The fountain of St. Tresain, which enjoys the reputation of curing diseases, and in the water of which it is pretended stolen food cannot be cooked, still exists at Mareuil.] [Footnote 383: The yield from the Ay vineyards averages five pièces, or 220 gallons per acre. Arthur Young, writing in 1787, estimated that the arpent (rather more than the acre) produced from two to six pièces of wine, or an average of four pièces, two of which sold for 200 livres, one for 150 livres, and one for 50 livres. He valued the arpent of vines at from 3000 to 6000 livres. Henderson, in his _History of Ancient and Modern Wines_, says that in 1822 there were a thousand arpents on the hill immediately behind the village of Ay valued at from 10,000 to 12,000 francs the arpent, and that one plot had shortly before fetched 15,000 francs per arpent.] [Footnote 384: In 1873, two years later, the price mounted as high as 1000 francs; while in 1880, owing to the yield being far below an average one and the quality promising to be exceedingly good, the wine was bought up before the grapes were pressed at prices ranging from 1100 to 1400 francs the pièce.] [Footnote 385: In one of these, dated 1243, mention is made of the 'vinea parva' belonging to the Abbey of Avenay, and of the 'vineam Warneri in loco qui dicetur Monswarins,' perhaps the existing clos Warigny. In another of Philip the Fair, dated 1300, and confirming the abbey in the possession of property purchased from Jeanne de Sapigneul, we read of 'unam vineam dictam la grant vigne domine Aelidis sitam en Perrelles' and 'unam vineam dictam a la Perriere.' In charters of the fourteenth century vineyards are mentioned at Avenay and Mutigny, under the titles of Les Perches, Haut-Bonnet, Praëlles, Les Foissets, Fond de Bonnet, Berard, Chassant, &c. One sold to the abbey in 1334 by Guillaume de Valenciennes was at a spot then, as now, styled Plantelles. In 1336 the justices at Château-Thierry confirmed the Abbess, Madame Clémence, in the 'droit de ban vin'--that is, the right of selling her wine before any one else in the territory of Avenay. This was again confirmed in 1344 by the Bailly of Sézanne, who held that she alone had the right of selling during the month after Christmas, the month after Easter, and the month after Pentecost. Amongst other records is one noting the condemnation of Perresson Legris, clerk, of Avenay, who was sentenced in 1460 by the Bailly of Epernay to a fine of 60 sols, for selling his wine during the month after Christmas without permission of the Dames d'Avenay. The charters of the fifteenth century also abound in references to vineyards, or 'droits de vinage,' appertaining to the abbey at Les Coutures, Champ Bernard, Auches, Bois de Brousse, Thonnay, &c., in the territory of Avenay, and Les Charmières, Torchamp, Saussaye, &c., at Mutigny.] [Footnote 386: In 1668, an epoch at which the wines of Avenay had acquired a high reputation, the abbey owned 43 arpents of vineland at Avenay, Mutigny, and Mareuil, yielding the preceding year 200 poinçons of wine, the sale of which produced 6000 livres. It also had 13 pressoirs banaux, which were farmed for 50 poinçons of wine, and tithes of wine at Mareuil amounting to 14 poinçons and 460 livres in money, and at Ambonnay amounting to 3 poinçons, the total of 67 poinçons fetching 1206 livres. The valet who looked after the vines had 50 livres per annum, and the cooper who looked after the wines, 40 livres. The total cost of stakes, manure, culture, pruning, wine-making, and casks was 2700 livres per annum. Ten pièces of wine 'of the best of the abbey, and worth 300 livres,' were annually given away in caques and bottles to 'persons of quality and friends of the house, and travellers of condition who pass;' whilst 120 poinçons, valued at 3000 livres, were consumed at the abbey itself. The abbey was partially destroyed by fire in 1754; and its destruction was completed during the Revolution, at which epoch its vineyards yielded a net revenue of 2500 livres.] [Footnote 387: In addition to Madame de la Marck, who was connected, by the marriage of one of her brothers to a princess of the house of Bourbon, with Henri Quatre, and to whose influence with that monarch the execution of the 'Traité des Vendanges' was mainly due, the roll of the Abbesses of Avenay comprises several illustrious personages, amongst them St. Bertha; Bertha II., daughter of the Emperor Lothaire; the ex-Empress Teutberga; Bénédicte de Gonzague, daughter of the Duke de Nevers, and sister of the Princess Palatine, who took such an active part during the troubles of the Fronde; and ladies of the illustrious families of Saulx Tavannes, Craon, Levis, Beauvillers, Brulart de Sillery, Boufflers, &c. M. Louis Paris, in his _Histoire de l'Abbaye d'Avenay_, gives some curious instances of the exercise of the 'haut et basse justice' possessed by these ladies. In 1587, under the rule of Madame de la Marck, we find the Bailly of Avenay, acting as 'first magistrate of Madame l'Abbesse,' sentencing one man and four women 'to be hung, strangled, and burnt, and the goods belonging to them confiscated to the profit of the Lady Justiciary,' for the crime of sorcery. In 1645 we find a 'sentence of the Bailly of Avenay against Simeon Delacoste, accused and convicted of the crime of homicide committed upon the person of Jean Bernier, and for this condemned to be hung and strangled by the executioner on a gallows erected in the public market-place, with confiscation of 300 livres, to be levied on his goods, to the profit of the Lady Justiciary.' When the criminal could not be caught, as was the case with Nicholas Thimot, vine-grower at Avenay in 1555, the sentence ran that he should 'be hung in effigy, and his goods confiscated to the profit of Madame.'] [Footnote 388: The following lines, quoted by M. Philibert Milsand in his _Procès poétique touchant les Vins de Bourgogne et de Champagne_, may be taken as referring either to the wine or the scenery: 'Si quis in hoc mundo vult vivere corde jocoso, Vadat Cumerias sumere delicias.' ] [Footnote 389: In Arthur Young's time (1787-9) an arpent of vineyard at Hautvillers, valued at 4000 livres, yielded from two to four pièces, or hogsheads, of wine, which sold from 700 to 900 livres the queue (two pièces). This is more than the wine would ordinarily realise to-day, although in years of scarcity it has fetched 700 francs the pièce, and in 1880 as much as 1000 francs.] [Footnote 390: Cazotte, ex-Commissary-General of the Navy and author of the _Diable Amoureux_, who was guillotined as a Royalist in 1792, had a magnificently fitted mansion at Pierry. He distinguished himself by his opposition to the pretensions of the Abbey of Hautvillers, which in 1775 claimed the right of taking tithes at Pierry not only in the vineyards, but on the wine in the cellars. Cazotte argued that unless the monks chose to take their due proportion of grapes left for them at the foot of each vine, all they were entitled to was a monetary commutation of the tithe; for the wine being usually made of grapes from a dozen different sources, many of them beyond their domain, it would be impossible to ascertain the proportion that was their due. The Parliament of Paris decided, however, that the abbey might take the fortieth of the wine a month after it was barrelled, unless the vine-growers preferred to give them the fortieth part of all the grapes brought to the press. The fact was that the monks really wished to check the practice of mixing grapes from different districts at the press, for fear wine equal to their own should result from this plan, first satisfactorily put in practice by Dom Perignon. Arthur Young mentions that an arpent of vines at Pierry was valued at 2000 livres, half the price the same extent commanded at Hautvillers.] [Footnote 391: M. Armand Bourgeois, in his work on _Le Sourdon et sa Vallée_, mentions a local tradition to the effect that Saint Remi, who from his will is shown to have owned vinelands of some extent in a part of this district still known as the Evêché, installed a hermit in this said grotto of the Pierre de Saint Mamert to supervise his vineyards.] [Footnote 392: Bertin du Rocheret writes thus in 1744, and adds that the aspect of Avize had at that epoch become entirely changed by the numerous fine 'maisons de vendange' erected there.] [Footnote 393: In 1205 Gilbert Belon conferred an annual gift on the Abbey of St. Martin of seven hogsheads of _vinage_ derived from the vineyards of Oger.] [Footnote 394: 'Je fus jadis de terre vertueuse Nez de Virtuz, pais renommé, Où il avait ville très gracieuse, Dont li bon vin sont en maints lieux nommés.' Eustache Deschamps' poem on the Burning of Vertus. ] [Footnote 395: 'Quant vient de si noble racine Come du droit plan de Beaune, Qui ne porte pas couleur jaune Mais vermeille, franche, plaisant, Qui fait tout autre odeur taisant, Quand elle est aportée en place.' Deschamps' _La Charte des Bons Enfans de Vertus_. ] [Footnote 396: 'Si vous alez au benefice Mieulx vous vauldra que ung clistère.'--Ibid. ] [Footnote 397: In 1880 the Vertus wine realised the remarkably high price of from 1200 to 1400 francs the pièce.] [Footnote 398: St. Evremond's _Letters_ (London, 1728).] [Footnote 399: St. Simon's _Mémoires_.] [Footnote 400: Bertin du Rocheret's /MS./ extracts from the _Registre des Assemblées du peuple de la ville d'Epernay_.] [Footnote 401: Henderson's _History of Ancient and Modern Wines_.] [Footnote 402: Arthur Young's _Travels in France in 1787-8-9_.] [Footnote 403: Anonymous _Journal de ce qui s'est passé d'intéressant à Reims en 1814_.] [Footnote 404: Dom Chatelain, in his /MS./ notes on the _History of Reims_, relates that Henri Quatre, being one day at Sully's, asked the Minister for some breakfast, and after drinking a glass or two of wine, exclaimed, 'Ventre Saint Gris, this is a grand wine; it beats mine of Ay and all others. I should like to know where it comes from.' ''Tis my friend Taissy,' answered Sully, 'who sends it to me.' 'Then I must be introduced to him,' said the King; which was accordingly done. The wines of Taissy had a high reputation as late as the eighteenth century. They were classed by St. Evremond and Brossette, the commentator of Boileau, amongst the best vintages of the Champagne, and their reputation was maintained by the care bestowed by the Abbé Godinot on the vineyards which he owned here.] [Footnote 405: 'Qu'Horace du Falerne entonne les louanges, Que de son vieux Massique il vante les attraits; Tous ces vins si fameux n'égaleront jamais Du charmant Sillery les heureuses vendanges!' Translation by Le Monnoye in the _Recueil des Poésies Latines et Françaises_, &c., Paris, 1712.] [Footnote 406: The wine of Verzenay, like that of Bouzy, owes much of its reputation to the example set in the eighteenth century by the Abbé Godinot, author of the _Mémoire_ on the cultivation of the grape and the manufacture of wine in the Champagne, published in 1711. He owned extensive vineyards at Verzenay and Bouzy, and his prolonged investigations as to the species of vines and composts best suited to the district led to a complete revolution in the system of culture and mode of pressing the fruit. Bertin du Rocheret praises 'the excellent wine of Verzenay' served at the banquets celebrating the conclusion of the assembly of the Etats de Vitry, held at Châlons in 1744.] [Footnote 407: The value in 1880 of a hectare of vines, equivalent to nearly two and a half acres, was as follows: At Verzy, Verzenay, and Sillery, 35 to 38,000 francs. " Bouzy and Ambonnay, 38 " 40,000 " " Ay and Dizy, 40 " 45,000 " " Hautvillers, 20 " 22,000 " " Pierry, 18,000 " " Cramant and Avize, 38 " 40,000 " " Le Mesnil, 22 " 25,000 " ] [Footnote 408: This was far from being the first appearance of the pest in this district. From 1779 to 1785 similar ravages drove the vignerons to despair; but the weather during the last-named year suddenly turning wet and cold, just at the epoch of the butterflies emerging from their chrysalids, the evil disappeared as though by enchantment, an event duly acknowledged by parochial rejoicings and religious processions. In 1816 similar ravages took place; and from 1820 to 1830 the pyrale also caused great devastation. In the year 1613, Jehan Pussot, the local chronicler of Reims, notes that a large proportion of the vines were destroyed by 'a great concourse of worms,' which attacked those plants which the frost had spared. This would establish that either the pyrale or the cochylis was known to the Champenois viticulturists at the commencement of the seventeenth century.] [Footnote 409: In 1873, in all the higher-class vineyards, as much as two francs and a quarter per kilogramme (11_d._ per lb.) were paid, being more than treble the average price. And yet the vintage was a most unsatisfactory one, owing to the deficiency of sun and abundance of wet throughout the summer. The market, however, was in great need of wine, and the fruit while still ungathered was bought up at most exorbitant prices by the _spéculateurs_ who supply the _vin brut_ to the Champagne manufacturers. In 1874 the grapes of the Mountain sold from at 55 to 160 francs the caque, according to the crus; and those of the Côte d'Avize at from 1 f. 25 c. to 2 f. per kilogramme. In 1875, on the other hand, grapes could be obtained at Verzenay, Verzy, Ambonnay, and Bouzy at from 45 to 55 francs the caque; and at Vertus, Le Mesnil, Oger, Grauves, Cramant, and Avize, at from 40 to 70 centimes the kilogramme. By far the highest price secured by the growers for their grapes was in 1880, when the produce of the grand crus of the Mountain fetched as much as 220 f. the caque, equal to nearly 3 f. 60 c. the kilogramme, or about 1_s._ 5_d._ per lb. It was, as usual, scarcity rather than quality that caused this unprecedented rise in price.] [Footnote 410: M. Mauméné relates in his _Traité du Travail des Vins_ that on one occasion, when, as an experiment, 3000 first-class bottles, which had already been used, were employed anew, only fifteen or sixteen of the whole number resisted the pressure. Moreover, if much broken glass is remelted down and used in the manufacture, the bottles do not turn out well, the second fusion of silicates never having the same cohesion as the first. The glass-works of Sèvres and Bercy, which melt down most of the broken glass collected in Paris, have never been able to supply bottles strong enough for sparkling wines.] [Footnote 411: Loivre is about seven miles from Reims on the road to Laon.] [Footnote 412: It is calculated that wine, the grape sugar in which yields ten per cent of alcohol, according to the average in Champagne, would, if bottled immediately after pressing, produce enough carbonic acid gas to develop a pressure of thirty-two atmospheres. But such a pressure is never developed, as the wine is not bottled directly it leaves the press; besides which no bottle could stand it. From four to six atmospheres insure a lively explosion and a brisk creamy foam. It is necessary, therefore, that fermentation should have been carried on till at least three-fourths of the sugar have been converted into alcohol and carbonic acid gas before the wine is drawn off for bottling, for even the very best bottles burst under a pressure of eight atmospheres. A few words on the origin and development of the effervescent properties of Champagne will not be out of place here. These are due, as already explained, to the presence of a large quantity of carbonic acid gas, the evolution of which has been prevented by the bottling of the wine prior to the end of the alcoholic fermentation. The source of carbonic acid gas exists in all wines, and they may be all rendered sparkling by the same method of treatment. Still, no effervescent wine can compare with the finest growths of the Champagne, for these possess the especial property of retaining a large portion of their sugar during, and even after, fermentation; besides which, the soil imparts a native bouquet that no other wine can match. Carbonic acid gas is one of the two products of the fermentation of grape sugar, the other being alcohol. In wine fermented in casks it rises to the surface, and escapes through the bunghole left open for the purpose. The case is different with wine fermenting in bottles tightly secured by corks. Part of the gas developed rises into the chamber or vacant space left in the bottle, where, mingling with the atmospheric air, it exercises a constantly increasing pressure on the surface of the wine. This pressure at length becomes so strong as to keep all the gas subsequently formed dissolved in the wine itself, which it saturates, as it were, and thereby converts into sparkling wine. Upon the bottle being opened, the gas accumulated in the chamber rushes into the air, producing a slight explosion, or pop, and freeing from pressure the gas which had remained dissolved in the wine, and which in turn escapes in the shape of numberless tiny bubbles, forming the foam so pleasing to the eye on rising to the surface. Sometimes on opening a bottle of Champagne the pop is loud, but the effervescence feeble and transitory; and, on the other hand, there is merely a slight explosion, and yet the wine froths and sparkles vigorously and continuously. The two bottles may contain the same quantity of gas, but in the one there is more in the chamber and less dissolved in the wine, and hence the loud pop and slight sparkle; while in the other the pressure is low, and the explosion consequently slighter, but there is more gas in the wine itself, and the effervescence is proportionately greater and more lasting. In the former case the wine has received the addition of, or has contained from the outset, some matter calculated to diminish its power of dissolving carbonic acid gas, and is unsuitable for making good sparkling wine. The nature of the effervescence is one of the best tests of the quality of the wine. Gas naturally dissolved does not all escape at once on the removal of the pressure, but, on the contrary, about two-thirds of it are retained by the viscidity of the wine. The better and more natural the wine, the more intimately the carbonic acid gas remains dissolved in it, and the finer its bubbles. The form of the glass out of which Champagne is drunk has an influence on its effervescence. The wine sparkles far better in a glass terminating in a point, like the old-fashioned _flûte_, or the modern goblet or patera, with a hollow stem, than in one with a rounded bottom. The reason is that any point formed around the liquid, as instanced in the pointed bottoms of these glasses, or in the liquid, as may be proved by putting the end of a pointed glass rod into the wine, favours the disengagement of the gas. Powder of any kind presents a number of tiny points, and hence the dropping of a little powdered sugar into Champagne excites effervescence. Porous bodies like bread-crumbs produce the same effect. Even dust has a similar action; and the wine will froth better in a badly-wiped glass than in one perfectly clean, though it would hardly do to put forward such an excuse as this for using dirty goblets. The lively pop of the cork is less esteemed in England than in certain circles in France, where many hosts would be sadly disappointed if the wine they put before their guests did not go off with a loud bang, causing the ladies to scream and the gentlemen to laugh. A brisk foam, too, is absolutely necessary for the prestige of the wine, and 'grand mousseux' is a quality much sought after by the general public on the other side of the Channel. It is not rare to meet with wines of a high class in which the removal of the cork produces a loud explosion; but unfortunately the brisk report and sharp but transitory rush of foam are features easily imparted by artificial means. The ordinary white wines of Lorraine and other provinces receive a certain addition of spirit and liqueur, and are then artificially charged with carbonic acid gas obtained from carbonate of lime, chalk, and similar materials, after the fashion in which soda-water is made. These wines, sold as Champagne, eject their corks with a loud pop, but three-fourths of the carbonic acid gas escape at the same time, and the wine soon becomes flat and dead; whereas a naturally sparkling wine of good quality left open for three hours and then recorked will be found fresh and drinkable the next day. Both the explosion and the subsequent effervescence are aided by a high temperature, which assists the development of the gas. Cold has the opposite effect, and iced wine neither pops nor sparkles. It, however, retains, if genuine, the whole of the carbonic acid gas held dissolved, which is not the case with the imitations spoken of. Were it not that the question has been seriously started on more than one occasion, and only solved to the satisfaction of the questioner by a chemico-anatomical explanation, it would hardly be worth while touching upon the supposed hurtfulness of the carbonic acid gas contained in sparkling wines. The fact of accidents frequently occurring in breweries, distilleries, wine-presses, &c., from the accumulation of this gas, to breathe which for a few seconds is mortal, has led some people to wonder how Champagne, whilst containing so large a proportion of it, can be swallowed with impunity. The gas, however, which produces fatal results when inhaled into the lungs, by depriving the blood of the oxygen which it should find there, has in the stomach a beneficial effect, serving to promote digestion. In drinking Champagne it is conveyed direct to this latter region, so that no danger whatever exists, any more than in the mineral waters.--Mainly condensed from E. J. Mauméné's _Traité du Travail des Vins_.] [Footnote 413: For a long time the most erroneous ideas as to the cause of such breakage and the means of preventing it prevailed. Tasting, which was most relied on for ascertaining how far fermentation had gone, could not be depended upon with accuracy, though the rule of thumb laid down by some makers was that the time to bottle with the least risk of breakage was when the sweet taste had disappeared, and vinous flavour developed itself. The aerometers subsequently introduced failed to answer the purpose, because the saccharine matter was not the only thing capable of influencing them. The result usually was either the bottling of a must so full of effervescence as to break the bottles, or of wine already completely fermented and incapable of effervescing at all.] [Footnote 414: In some establishments tables made after the same fashion replace the racks, whilst another plan of coaxing the sediment down towards the cork is to stack the bottles at the outset in double rows, with their necks inclining downwards, laths placed between each layer maintaining them in their position. This method effects a great economy of time and space, the bottles requiring on an average only a few days on the racks prior to shipment to thoroughly complete the operation.] [Footnote 415: As the real origin of this system is a matter which has excited no small amount of controversy, and as several claimants to the honour of its discovery have had their names put forward by different writers, the following extracts from a letter from M. Alfred Werlé, of the house founded by Madame Clicquot, may serve to render honour where it is really due: 'Already, in 1806 (I am unable to speak of an earlier period with absolute certainty), the bottles were placed on tables, like to-day, with their heads downwards; each bottle being taken out of its hole, raised in the air, and shaken with the hand, so as to cause the cream of tartar and the deposit it contained to fall upon the cork, the holes being round, and the bottles placed straight downwards. This lasted till 1818, when a man named Müller, an employé of Madame Clicquot, suggested to her that the bottles should be left in the table whilst being shaken, and that the holes should be cut obliquely, so that the bottles might remain inclined. He maintained that one would thus obtain a wine of far greater limpidity. The trial was made, and every day, with a view of keeping this new process a secret, Müller and Madame Clicquot shut themselves up alone in the cellars, and shook the bottles unperceived. In 1821 Müller was assisted by a workman named Mathieu Binder; and in 1823 or 1824, Madame Clicquot having purchased from M. Morizet a _cuvée_ of wine which was shaken and prepared in this merchant's cellars, one of his employés named Thomassin became acquainted with the new method, and resolved to practise it; since when it gradually spread, and eventually was generally adopted. M. Werlé senior recollects perfectly well that when he arrived at Madame Clicquot's in 1821 it was only at her establishment that the bottles were shaken in this manner. The practice of shaking the bottles was a very old one, and no more invented by Müller than by Thomassin; but the former certainly effected great improvements by employing the system of oblique holes, and shaking the bottles in the table and not in the air.'] [Footnote 416: M. Mauméné has pointed out that if a solution of tannin or alum has been added to the _cuvée_ at the time of fining, the deposit is certain to be granular and non-adherent. But he justly remarks that these solutions, especially the latter, though doing good to the wine, have a precisely opposite effect upon the human stomach that consumes it.] [Footnote 417: The Regiment de Champagne was one of the most famous of the _vieux corps_, and claimed to be the second oldest regiment in the French army.] [Footnote 418: The system of dosing the wine does not appear to have been practised prior to the present century.] [Footnote 419: The high favour in which sugar-candy is held for mixing with this Champagne liqueur dates from the latter part of the last century, when there was a perfect mania for everything in a crystallised form, as being the height of condensation and purity. The competition between the first houses of Reims and Epernay to secure the largest and finest crystals was very keen, and it was considered disgraceful for any firm of standing to make use of sugar-candy of a yellow tinge or in small crystals. Latterly it has been demonstrated that these expensive crystals contain more water and less saccharine matter than an equal weight of loaf-sugar, and that they sometimes contain a glutinous element capable of imparting an insipid flavour to the wine.--Mauméné's _Traité du Travail des Vins_.] [Footnote 420: Instances have been known of additions of 25 and even 30 per cent of liqueur, though the average may be taken to be for Germany and France, 15 to 18 per cent; America, 10 to 15 per cent; England, 2 to 6 per cent.] [Footnote 421: The corrosive action of rust upon the wire has led to several attempts to replace it, and some Champagne houses have adopted more or less ingenious appliances of metal, &c. Tinned iron wire has been found to resist rust, but is too expensive; whilst an experiment with galvanised wire resulted in serious illness amongst the workmen handling it, owing to the poisonous fumes evolved by the zinc when acted upon by the acids of the wine.] [Footnote 422: M. Viollet-le-Duc, _Dictionnaire raisonné de l'Architecture du Vme au XVIme Siècle_.] [Footnote 423: An engraving of this tower, removed while the present work was passing through the press, will be found on p. 50.] [Footnote 424: See the engraving on p. 16.] [Footnote 425: Read before the Academy of Reims in February 1845, printed by them in their Transactions, and subsequently republished in volume form.] [Footnote 426: It is generally supposed that the gate took its name from a hospital standing a short distance without the walls, and destined for the reception either of lepers or of pilgrims arriving after nightfall. The prevalent opinion is that it bore the inscription _Dei merito_, translated as Dieu le mérite, which became corrupted into Dieu-Lumière. Under Louis XI. it certainly figures as Di Merito.] [Footnote 427: A curious old engraving copied from an ancient tapestry represents the entry of the royal procession into Reims through the Porte Dieu-Lumière. Joan of Arc, beside the king and in company with the Dukes of Bourbon and Alençon, bears the banner of France; whilst her father and mother are seen arriving with the king's baggage by another road.] [Footnote 428: /A.D./ 499.] [Footnote 429: Victor Fievet's _Histoire d'Epernay_.] [Footnote 430: M. A. Nicaise's _Epernay et l'Abbaye de St. Martin_.] [Footnote 431: Ibid.] [Footnote 432: Victor Fievet's _Histoire d'Epernay_. In December 1540, when the eschevins fixed the 'vinage,' the queue of wine was valued at eight to nine livres.] [Footnote 433: The partiality of Charles V. for the wine of Ay has been elsewhere spoken of. The vendangeoir mentioned was in existence in 1726.] [Footnote 434: Victor Fievet's _Histoire d'Epernay_.] [Footnote 435: M. A. Nicaise's _Epernay et l'Abbaye de St. Martin_.] [Footnote 436: Ibid.] [Footnote 437: The thoroughfare at Epernay known as the Rempart de la Tour Biron commemorates the above event.] [Footnote 438: Victor Fievet's _Histoire d'Epernay_.] [Footnote 439: 'Ce diable à quatre A le triple talent De boire et de battre, Et d'être vert-galant.' ] [Footnote 440: 'On lui verse le vin de la côte voisine, Pétillant, savoureux qui soudain l'illumine D'étincelants rayons de joie et de gaîté; Redevenant poëte, il chante la beauté Qui l'aide à conquérir doucement la Champagne.' M. Camille Blondiot's _Henri IV. au Siège d'Epernay_. ] [Footnote 441: 'Viens aurore, Je t'implore, Je suis gai quand je te voi; La bergère Qui m'est chère Est vermeille comme toi. Elle est blonde, Sans seconde, Elle a la taille à la main; Sa prunelle Etincelle Comme l'astre du matin. De rosée, Arrosée, La rose a moins de fraîcheur; Une hermine Est moins fine, Le lis a moins de blancheur. D'ambroisie, Bien choisie, Dupuis se nourrit à part; Et sa bouche Quand j'y touche Me parfume de nectar.' ] [Footnote 442: From the _Extrait du Registre et Papiers des Assemblés du Peuple de la Ville d'Epernay_, preserved in the /MSS./ of Bertin du Rocheret.] [Footnote 443: Bertin du Rocheret's /MSS./] [Footnote 444: Ibid.] [Footnote 445: _Mémoire concernant la Ville d'Epernay_, by Maître François Stapart, notaire au bailliage, published in 1749.] [Footnote 446: Max Sutaine's _Essai sur le Vin de Champagne_.] [Footnote 447: Arthur Young's _Travels in France in the Years 1787-8-9_.] [Footnote 448: Victor Fievet's _Histoire d'Epernay_. In the list of expenses incurred on the passage of Louis XVI. and his family, four hundred livres are set down to 'the Sieur Memmie Cousin, innkeeper and merchant at Epernay, for the dinner of the king, the queen, and the royal family, as well as for an indemnity for the furniture broken at the said Cousin's.' As regards the price of the wines of the River during the Revolutionary epoch, an old account-book of Messrs. Moët & Chandon shows that in 1797 the firm paid for the white wine of Epernay and Avize 200 francs, for that of Chouilly 180 francs, and for that of Pierry and Cramant 150 francs per pièce; whilst that of Ay cost from 565 to 600 francs the queue. Bottles in 1790 only cost 16 livres 10 sols the hundred.] [Footnote 449: The Clos St. Pierre is now the property of M. Charles Porquet, and the ancient seignorial residence of the monks of St. Pierre, at Pierry, is occupied by M. Papelart. Both these gentlemen are wine-merchants.] [Footnote 450: Cazotte, writing in October 1791, speaks of the village as peopled with 'gros propriétaires;' and in November, that it had 'thirty-two households of well-to-do people.' Amongst its inhabitants were the Marquis Tirant de Flavigny, Dubois de Livry, Quatresols de la Motte, De Lastre d'Aubigny, De Lantage, &c., most of whose residences are still extant. In October 1792 several accusations were made against soldiers for picking and eating grapes in the vineyards of Pierry and Moussy, belonging to Cazotte, De la Motte, De Lantage, D'Aubigny, &c.] [Footnote 451: Part of it now serves as the 'maison communale' and school-house of the village.] [Footnote 452: Arrested at Pierry in August 1792, in consequence of the discovery, on the sacking of the Tuileries, of a new plan of escape for the royal family, sent by him to his friend Ponteau, secretary of the Civil List, Cazotte was brought to Paris and immured, in company with his daughter Elizabeth, in the prison of the Abbaye. Arraigned before the self-constituted tribunal presided over by the butcher Maillard, on the night of the 3d September, the fatal words 'To La Force,' equivalent to a sentence of death, were pronounced; and Cazotte was about to fall beneath the sabres already raised against him, when Elizabeth covered his body with her own, and by her heroic appeals induced the assassins to forego their prey. She even had the courage to drink with them to the Republic, and with her father was escorted home in triumph. A few days later, however, he was rearrested, condemned to death by the Revolutionary Tribunal, and on the 25th September ascended the scaffold, from whence he cried with a firm voice to the multitude, 'I die as I have lived, faithful to God and my king.' Under date of the 10 Prairial An II. (1793), the citizen Bourbon was appointed by the municipality of Pierry to cultivate the vineyards 'du gillotiné (_sic_) Cazotte.'] [Footnote 453: In 1775 the Abbot of Hautvillers, as _décimateur_ of Pierry, claimed to take tithe of a fortieth of all wines in the cellars of the village. This claim being rejected by the baillage of Epernay in 1777, he appealed to the Parliament of Paris. Cazotte undertook the case of his fellow-proprietors, pleading that the abbey, which, according to strict law, was bound to take the tithe in the shape of grapes left at the foot of each vine, had long since replaced this by a monetary commutation; and that the inhabitants of Pierry, like the other wine-growers of the Champagne, being 'obliged, in order to obtain perfection in their wines, to mix the grapes of several crus and different tithings, it would be impossible to tithe the wine itself.' He also argued that the question had been settled by a decision on the same point in favour of the inhabitants of Ay and Dizy. However, the monks obtained a decree from parliament authorising them to take the fortieth of the vintage a month after the wines had been barrelled, unless the wine-growers preferred 'to pay the tithe at the wine-press, in form of the fortieth load of grapes free from all mixture.' The inhabitants appealed in 1780, pleading the impossibility of this plan of tithing at the press, on account of the expense and of the difficulty of sorting out the grapes from those brought from Moussy, Vinay, Monthelon, Cuis, Epernay, and other districts in which they had also vineyards. The Revolution cut the Gordian knot of this affair, which really arose from the wish of the monks to hinder as much as possible that plan of mixing grapes from different sources, to which the perfection of their own wine was due.] [Footnote 454: In January 1790 the inhabitants of Pierry unanimously elected Cazotte their first mayor under the new _régime_. A decree signed by him in this capacity, and dated April 11, 1790, fixes the price for a day's work in the vineyards at 12 sols. In 1793 the municipality of the adjoining district of Moussy fixed the day's hire of the vintager at 25 sous, of horses employed in the vintage at 7 livres 10 sous, and of asses at 5 livres. As regards the price of the local cru, amongst the items of the accounts of the syndic of Moussy for the years 1787-8 is the following: 'For thirteen bottles of stringed wine (vin fisselé) sent to Paris to the procureur of the community (Failly lawsuit), 13 livres.' The community were then engaged in a lawsuit with the Count de Failly respecting a wood. During the Revolutionary epoch it was decreed by the municipality of Pierry that a vineyard known as les Rennes should, on account of the resemblance to les Reines, be in future styled les Sans-culottes. It has since resumed its old name.] [Footnote 455: The story of Cazotte prophesying not only his own fate, but that of the king and queen, Condorcet, Bailly, Malesherbes, Nicolai, the Duchess de Grammont, and others who perished during the Terror, at a dinner given at an Academician's in 1788, has been proved to be a mere invention on the part of La Harpe. Nevertheless there seems but little doubt that he distinctly foresaw many coming evils; and a native of Pierry, M. Armand Bourgeois, asserts that his maternal grandfather was one day at Cazotte's house in the village, when the entire company were completely upset by their host's prophecies of a coming revolution.] [Footnote 456: P. Jannet's _Recueil des Poésies françaises des 15me et 16me Siècles_.] [Footnote 457: Louis Perrier's _Mémoire sur le Vin de Champagne_.] [Footnote 458: St. Evremond's _Letters_, &c. (London, 1714).] [Footnote 459: Max Sutaine's _Essai sur le Vin de Champagne_.] [Footnote 460: Bertin du Rocheret's /MSS./ _Histoire d'Epernay_.] [Footnote 461: 'Ay produit les meilleurs vins-- J'en prends à témoin tout le monde; Mais vous préférez ceux de Reims, Ay produit les meilleurs vins. Ce sont les premiers, les plus fins, Et Saint Evremont me seconde. Ay produit les meilleurs vins-- J'en prends à témoin tout le monde. Charles Quint s'y connoissoit bien Il en faisoit la différence; Et mieux que son maître Adrien, Charles Quint s'y connoissoit bien, Pour en boire, il ne tint a rien Qu'il ne vînt demeurer en France. Charles Quint s'y connoissoit bien Il en faisoit la différence. Pour qu'on ne pût le mélanger, Et que sa table fût complète, Lui même faisoit vendanger, Pour qu'on ne pût le mélanger. Léon craignant même danger, D'un pressoir d'Ay fit emplète, Pour qu'on ne pût le mélanger, Et que sa table fût complète.' The Adrien mentioned in the second verse was Pope Adrian VI., who had been the Emperor's preceptor, and who by his influence obtained the tiara on the death of Leo X. Unlike his predecessor, he was very simple in his habits.] [Footnote 462: _Maison Rustique_, edition of 1574.] [Footnote 463: Louis Perrier's _Mémoire sur le Vin de Champagne_.] [Footnote 464: An allusion to the curse pronounced by St. Tresain against the men of Ay.] [Footnote 465: _Maison Rustique_ (1582), translated by Richard Surflet (London, 1600).] [Footnote 466: Ibid.] [Footnote 467: Ibid.] [Footnote 468: Paulmier's treatise, _De Vino et Pomaceo_ (1588).] [Footnote 469: _Maison Rustique_ (1582).] [Footnote 470: Legrand d'Aussy's _Vie privée des Français_.] [Footnote 471: Louis Perrier's _Mémoire sur le Vin de Champagne_.] [Footnote 472: _Recueil des Poésies latines et françaises sur le Vin de Champagne_ (Paris, 1712). Gonesse, a village of the department of Seine-et-Oise, about ten miles to the north of Paris, had a high reputation for its bread for several centuries.] [Footnote 473: 'Notre bon roi, le grand Henry, En régaloit sa belle hôtesse, Quand il couchoit à Damery, Notre bon roi, le grand Henry, C'étoit-là son jus favori; Et son pain, celui de Gonesse, Notre bon roi, le grand Henry, En régaloit sa belle hôtesse.' Published in the _Mercure_ of January 1728. Henry was accustomed to speak of the Présidente as his 'belle hôtesse.'] [Footnote 474: Circa 1590.] [Footnote 475: _Théâtre de l'Agriculture et Mesnage des Champs_ (1600).] [Footnote 476: Published at Orleans, 1605. As regards the price of the newly-made wine of Ay at this epoch, Jehan Pussot says that, in 1604, it fetched from 25 to 45 livres; in 1605, from 60 livres upwards; and in 1609, from 100 to 120 livres, at the epoch of the vintage.] [Footnote 477: Chaulieu says that St. Evremond 'Ne chante dans ses vers heureux Que l'inconstance et la Tocane'-- Tocane being usually made of the wine of Ay.] [Footnote 478: St. Evremond's _Works_ (London, 1714).] [Footnote 479: Chaulieu extols the Tocane of Ay, and some verses of Voltaire have been quoted on p. 61.] [Footnote 480: Arthur Young's _Travels in France in the Years 1787-8-9_.] [Footnote 481: CHAMPAGNE. Less for thy grace and glory, land of ours, Than for thy dolour, dear, Let the grief go; and here-- Here's to thy skies, thy women, and thy flowers! France, take the toast, thy women and thy roses; France, to thy wine, more wealth unto thy store! And let the lips a grievous memory closes Smile their proud smile once more! Swarthy Falernian, Massica the Red, Were ye the nectars poured At the great gods' broad board? No, poor old wines, all but in name long dead, Nectar's Champagne--the sparkling soul of mirth, That, bubbling o'er with laughing gas, Flashes gay sunbeams in the glass, And like our flag goes proudly round the earth. 'I am the blood Burgundian sunshine makes; A fine old feudal knight, Of bluff and boisterous might, Whose casque feels--ah, so heavy when one wakes!' 'And I, the dainty Bordeaux, violets' Perfume, and whose rare rubies gourmets prize; My subtile savour gets In partridge wings its daintiest allies.' Ah, potent chiefs, Bordeaux and Burgundy, If we must answer make, This sober counsel take: Messeigneurs, sing your worth less haughtily, For 'tis Champagne, the sparkling soul of mirth, That, bubbling o'er with laughing gas, Flashes gay sunbeams in the glass, And like our flag goes proudly round the earth. Ay, 'tis the true, the typic wine of France; Ay, 'tis our heart that sparkles in our eyes, And higher beats for every dire mischance. It was the wit that made our fathers wise, That made their valour gallant, gay, When plumes were stirred by winds of waving swords, And chivalry's defiance spoke the words: 'A vous, Messieurs les Anglais, les premiers!' Let the dull beer-apostle till he's hoarse Vent his small spleen and spite-- Fate fill his sleepless night With nightmares of invincible remorse! We sing Champagne, the sparkling soul of mirth, That, bubbling o'er with laughing gas, Flashes gay sunbeams in the glass, And like our flag goes proudly round the earth. ] 
19985	----	Note: Project Gutenberg also has an HTML version of this file which includes the original illustrations and in which the index is linked to the corresponding pages. See 19985-h.htm or 19985-h.zip: (http://www.gutenberg.net/dirs/1/9/9/8/19985/19985-h/19985-h.htm) or (http://www.gutenberg.net/dirs/1/9/9/8/19985/19985-h.zip) Transcriber's note: Obvious printer's errors have been corrected, and the original spelling has been retained. Page numbers have been included to allow the reader to use the index. Page numbers of pages previously only containing illustration (and now empty) are not shown. Illustrations placed in the middle of paragraphes have been moved, thus, their page numbers have changed. The illustration index has been corrected to match the new position of the illustrations. In chemical formulas a subscripted number is shown by an underscore followed by the number within curly brackets. Thus the formula for water is given as H_{2}O. Text enclosed by pound signs (#) was in bold face. Additional notes are at the end of the text. THE DYEING OF WOOLLEN FABRICS by FRANKLIN BEECH Practical Colourist and Chemist; Author of "The Dyeing of Cotton Fabrics," Etc, With Thirty-Three Illustrations London Scott, Greenwood & Son 8 Broadway, Ludgate Hill, E.C. Canada: The Copp Clark Co., Ltd., Toronto United States: D. Van Nostrand Co., New York 1902 [All rights remain with Scott, Greenwood & Son.] PREFACE. (p. iii) In this little book the author has endeavoured to supply the dyer of woollen fabrics with a conveniently arranged handbook dealing with the various branches of the wool dyeing industry, and trusts that it will be found to meet the want which undoubtedly exists for such a book. The text on which the book is based is expressed in the title "The Dyeing of Woollen Fabrics," and in enlarging upon it the author has endeavoured to describe clearly and in some detail the various processes and operations generally, pointing out the principles involved and illustrating these by numerous recipes, showing the applications of a great variety of dyes in the production of the one thousand and one tints and shades the wool dyer is called upon to produce on the fabrics with which he is working. In pursuance of this plan nothing is said of the composition and properties of the various dyes, mordants, chemicals, etc., which are used. This is information every wool dyer should possess, but the author believes it is better dealt with in books devoted to Chemistry proper. _May, 1902._ CONTENTS. (p. v) CHAPTER I. Page THE WOOL FIBRE-- Structure, Composition and Properties...................... 1 CHAPTER II. PROCESSES PREPARATORY TO DYEING-- Scouring and Bleaching of Wool............................ 15 CHAPTER III. DYEING MACHINERY AND DYEING MANIPULATIONS-- Loose Wool Dyeing, Yarn Dyeing and Piece Dyeing Machinery................................................. 40 CHAPTER IV. THE PRINCIPLES AND PRACTICE OF WOOL DYEING-- Properties of Wool -- Methods of Wool Dyeing -- Groups of Dyes --Dyeing with the Direct Dyes -- Dyeing with Basic Dyes -- Dyeing with Acid Dyes -- Dyeing with Mordant Dyes -- Level Dyeing -- Blacks on Wool -- Reds on Wool -- Mordanting of Wool -- Orange Shades on Wool -- Yellow Shades on Wool -- Green Shades on Wool -- Blue Shades on Wool -- Violet Shades on Wool -- Brown Shades on Wool -- Mode Colours on Wool.................... 59 CHAPTER V. DYEING UNION (MIXED COTTON AND WOOL) FABRICS............... 168 CHAPTER VI. DYEING OF GLORIA........................................... 188 CHAPTER VII. (p. vi) OPERATIONS FOLLOWING DYEING-- Washing--Soaping--Drying................................. 197 CHAPTER VIII. EXPERIMENTAL DYEING AND COMPARATIVE DYE TESTING............ 211 CHAPTER IX. TESTING OF THE COLOUR OF DYED FABRICS...................... 218 INDEX...................................................... 225 LIST OF ILLUSTRATIONS. (p. vii) Fig. Page 1. Microscopical Sketch of Wool Fibre....................... 2 2. Kempy Wool Fibres........................................ 3 3. Sectional View of Wool Fibre............................. 4 4. Wool Fibres Showing Action of Alkalies.................. 10 5. Wool Fibres Showing Action of Acids..................... 11 6. Wool Washing Machine.................................... 20 7. Wool Cloth Washing Machine.............................. 28 8. Woollen Cloth Washing Machine........................... 29 9. Sulphur Bleach House.................................... 29 10. Dyeing Tubs and Vat..................................... 41 11. Section of Dye Vat...................................... 42 12. Delahunty's Dyeing Machine.............................. 44 13. Obermaier Dyeing Machine................................ 44 14. Holliday's Yarn Dyeing Machine.......................... 47 15. Klauder-Weldon Yarn Dyeing Machine...................... 47 16. Dyeing Jiggers for Cloth................................ 51 17. Dyeing Jiggers for Cloth................................ 53 18. Jig Winch Dyeing Machine................................ 53 19. Cloth Dyeing Machine.................................... 54 20. Plush Fabric Dyeing Machine............................. 55 21. Dye Beck for Cloth...................................... 56 22. Hawking Machine......................................... 57 23. Indigo Dye Vat for Cloth............................... 149 24. Squeezing Rollers...................................... 199 25. Yarn Washing Machine................................... 201 26. Cloth Washing Machine.................................. 202 (p. viii) 27. Cloth Washing Machine.................................. 204 28. Soaping and Washing Machine............................ 205 29. Hydro-extractor........................................ 206 30. Hydro-extractor........................................ 207 31. Yarn Drying Apparatus.................................. 208 32. Cloth Drying Machine................................... 208 33. Experimental Dye Apparatus............................. 212 CHAPTER I. (p. 001) THE WOOL FIBRE. Wool is one of the most important textile fibres used in the manufacture of woven fabrics of all kinds. It belongs to the group of animal fibres of which three kinds are met with in nature, and used in the manufacture of textile fibres; two of these are derived from quadruped animals, such as the sheep, goat, etc., while the third class comprises the products of certain insects, _e.g._, silk. The skin of all animals is covered with more or less of a fibrous coat, which serves as a sort of protecting coat from the weather to the skin underneath. Two different kinds of fibres are found on animals; one is a stiff kind of fibre varying in length very much and called hairy fibres, these sometimes grow to a great length. The other class of animal fibres are the woolly fibres, short, elastic and soft; they are the most esteemed for the manufacture of textile fabrics, it is only when the hairy fibres are long that they are serviceable for this particular purpose. There is a slight difference in the structure of the two kinds of fibre, woolly fibres having a more scaly structure than hairy fibres; the latter also differ in being more cylindrical in form. #Wool.#--By far the most important of the animal fibres is wool, the fibre of the domestic sheep. Other animals, the llama or alpaca, the Angora and Cashmere goats also yield fibres of a similar character, which are imported under the name of wools. There are many (p. 002) varieties of wools Which are yielded by the various breeds of sheep, but they may be roughly divided into two kinds, according to the length of "staple," as it is called. In the long-stapled wools the fibres average from 7-1/2 to 9-1/2 inches in length, while the short-stapled wools vary from 1 to 2 inches long. The diameter varies very considerably from 0.00033 to 0.0018 of an inch. [Illustration: Fig. 1.--Wool Fibre under the Microscope.] Two varieties of thread are spun from wool, one is known as "worsted," the other as "woollen" yarns; from these yarns two kinds of cloths are woven, distinguished as worsted and woollen cloths; the former are in general not subjected to any milling or felting process, while the latter invariably are. #Physical Properties.#--When seen under the microscope the wool fibres show a rod-like structure covered with broad scales, the edges of which project from the body of the fibre, and all point in one direction. Fig. 1 shows typical wool fibres as viewed under the microscope; the sketch shows very well the scales. The shape of the scales varies in different breeds of wool. The (p. 003) outer scales enclose inner medullary cells, which often contain pigment matter. A transversed section of the wool fibre shows the presence of a large number of cells. Sometimes wool fibres are occasionally met with which have a peculiar white horny appearance; these do not felt or dye well. They are known as "kempy" fibres. See figure 2. The microscope shows that they are largely devoid of structure, and are formed of very horny, impenetrable tissue, which is difficult to treat in the milling or dyeing process. [Illustration: Fig. 2.--Kempy Wool Fibres.] The curly or twisted character of the fibre is caused by the unequal contraction of the outer scales, and depends in a great measure upon the hygroscopic nature of the wool. It may be entirely removed for the time by wetting the wool in hot water, then drying it in a stretched condition, or the curl may be artificially induced by unequal drying, a fact which is turned to practical account in the curling of feathers and of hair. The amount of curl in different varieties of wool is very variable, being as a rule greatest in the finer qualities, and diminishing as the fibre becomes coarser. The diameter of the wool fibre varies (p. 004) from 1/2000 to 1/5000 of an inch, and the number of curls from about 30 per cent. In fine wool as little as 1 or 2 per cent. in the thicker fibres. Elasticity and strength are properties which, in common with silk, wool possesses in a greater degree than the vegetable fibres. When submitted to strain the wool fibre exhibits a remarkable strength, and when the breaking point is reached the fracture always takes place at the juncture of two rings of the outer scales, the embedded edges of the lower layer being pulled out of their seat. The scales themselves are never broken. [Illustration: Fig. 3.--Wool Fibre showing Medullary Centre.] When first formed the cells are more or less of a spherical shape, and contain a nucleus surrounded by the ultimate photoplasmic substance. Those cells which constitute the core or central portion of the fibre retain to some extent this original globular form and pulpy condition. Surrounding this central portion or medulla, as it has been called (see fig. 3), and forming the main bulk of the fibre, there is a comparatively thick layer of partially flattened cells, which are also elongated in the direction of the length of the fibre, and outside this again there is a thinner stratum which may be compared to the bark of a tree. This outer covering differs materially from the (p. 005) rest of the fibre in its physical structure, but is, probably, nearly identical with it, though possibly not entirely so, in chemical composition. It consists of a series of flattened horny scales, each being probably an aggregation of many cells. The scales, which have been compared to the scales of a fish or to slates on a housetop, overlap each other, the free edges protruding more or less from the fibre, while the lower or covered edges are embedded and held in the inner layer of cells. The free edges always point away from the root of the fibre, just as do the bracts of a fir cone. When viewing a section of a wool fibre there is, of course, no sharp line of division between the three portions above described, but the change from the central spherical cells to the elongated cellular portion, and from these again to the flattened horny scales, is quite gradual, so that the separation into zones, though well marked, is very indefinite in respect of boundaries. The scaly structure of wool is of great importance in regard to what is known as felting property. When woollen fabrics are worked in boiling water, especially in the presence of soap, they shrink in length and breadth, but become thicker in substance, while there is a greater amalgamation of the fibres of the fabric together to form a more compact and dense cloth; this is due to the scaly structure of the wool fibres enabling them to become entangled and closely united together. In the manufacture of felt hats this is a property of very great value. #Variations in Physical Structure.#--Wool fibres vary somewhat amongst themselves; fibres from different breeds of sheep, or even from different parts of the same animal, vary greatly, not only in thickness, length, etc., but also in actual structure. A typical wool fibre, such as may be obtained a good merino or Southdown fleece, will possess the typical structure described above, but frequently the type is departed from to such an extent that the central core of (p. 006) globular cells is entirely absent. Also the serrated character of the outermost layer of cells reaches a much higher state of development in some samples of wool than in others. Wool is a much more hygroscopic fibre than cotton or any of the other vegetable fibres, usually it contains about 18 per cent. of water, but much depends upon the atmospheric conditions that prevail. This water is contained in the wool in two forms: (1) as water of hydration amounting to about 81 per cent., and (2) as hygroscopic water. Experiments have shown that when a piece of dried wool is exposed to an atmosphere saturated with water vapour it will absorb 50 per cent. of its weight; cotton under the same conditions will take up 23 per cent.; flax, 27·5 per cent.; jute, 28·5 per cent., and silk, 36·5 per cent. Heated to about 100° C. it parts with nearly the whole of its water and becomes hard, horny and brittle, exposed to the air, the dry wool again absorbs water and is restored to its former condition. When heated to 100° C. wool becomes somewhat plastic, so that whatever form is then imparted to it it will retain when it becomes cold, this property is very useful in certain processes of finishing wool fabrics, making hats, etc. #Chemical Composition.#--In the natural or raw state each wool fibre is surrounded by a considerable amount of foreign matter, so that in treating of its chemical constitution it is necessary to distinguish between pure wool and the raw fibre. The incrusting substance is technically known as "Yolk," or "Suint," and is principally composed of a kind of natural soap, consisting of the potash salts of certain fatty acids, together with some fats which are incapable of saponification. The amount of yolk present upon different samples of wool varies greatly, the finer varieties containing, as a rule, a larger proportion than the coarser, and less valuable sorts. The variation in the relative amount of pure fibres and yolk is (p. 007) well shown in the following analyses which, however, do not by any means represent extreme cases. ANALYSES OF RAW MERINO WOOL. DRIED AT 100° C. No. 1. No. 2. Moisture 6·26 10·4 Yolk 47·30 27·0 Pure Wool 30·31 59·5 Dirt 11·13 3·1 ------ ------ 100·00 100·00 Yolk consists very largely of two complex substances which have been termed wool perspiration and wool fat. The former is composed of the potash salts of fatty acids, principally oleic and stearic acids; the latter of the neutral carbohydrate, cholesterine, with other similar bodies. The wool perspiration may be removed by a simple washing with water, and on the Continent forms a valuable source of potash salts, since the ash after ignition contains 70 to 90 per cent. of potassium carbonate. The wool fat is insoluble in water, but dissolves readily in ether, benzene, carbon disulphide, etc. It is also removed from the wool by a treatment with alkali, and it is not easy to explain the action in the case, since the wool fat is not a glyceride, and will not form a soap, but is probably emulsified by the wool perspiration. #Chemical Composition of the Pure Fibre.#--The following analyses of purified and dried wool fibre indicate its percentage composition:-- Mulder. Bowman. Carbon 50·5 per cent. 50·8 per cent. Hydrogen 6·8 " 7·2 " Nitrogen 16·8 " 18·5 " Oxygen 20·5 " 21·2 " Sulphur 5·4 " 2·3 " ----- ----- 100·0 100·0 It is sometimes stated that wool fibre consists of a definite (p. 008) substance, keratine, but this view cannot now be admitted, since wool appears to be composed of a mixture or combination of several very complex substances. It is possible and even probable that the outer epidermal scales have a somewhat different composition to the bulk of the fibre, but whether that is the case or not is not known with any degree of certainty, this much can be asserted, that wool is not a simple definite chemical compound. Sulphur is by far the most variable constituent of wool, sometimes as little as 1·5 and occasionally as much as 5 per cent. being found. It appears to be always present in two different forms, one portion being in very feeble combination and easily removed by alkalies, the remainder, which, according to Knecht, amounts to about 30 per cent. of the total sulphur, cannot be removed without complete disintegration of the fibre. This latter portion does not give a black coloration with plumbite of soda. The amount of ash left on incinerating dry wool varies from 1 to 2 per cent., and some have considered this inorganic matter as an essential constituent. It consists principally of salts of potassium, calcium and aluminum, with, of course, sulphur. The chemical composition of the wool fibre is evidently of a most complicated nature; judging from its behaviour in dyeing it is evident that it may contain two bodies, one of a basic character which enables it to combine with the azo and acid series of dyes, the other possessing acid characters enabling it to combine with the basic dyes of the magenta and auramine type. Dr. Knecht has isolated from the wool fibre by extraction with alkalies and precipitation with acids a substance to which the name of lanuginic acid has been given. It is soluble in hot water, precipitates both acid and basic colouring matters in the form of coloured lakes. It yields precipitates with alum, stannous (p. 009) chloride, chrome alum, silver nitrate, iron salts, copper sulphate. It appears to be an albuminoid body. From its behaviour with the dyes, and with tannic acid and metallic salts, it would appear that lanuginic acid contains both acidic and basic groups. It contains all the elements, carbon, hydrogen, oxygen, nitrogen and sulphur, found in wool. If wool is dyed in a dilute solution of Magenta (hydrochloride of rosaniline), the whole of the base (rosaniline) is taken up, and the whole of the acid (HCl) left in the bath, not, however, in the free state, but probably as NH_{4}Cl, the ammonia being derived from the wool itself. A further proof of the acid nature of lanuginic acid is that wool may be dyed a fine magenta colour in a colourless solution of rosaniline base; for since rosaniline base is colourless, and it only forms a colour when combined with acids, the fibre has evidently acted the part of an acid in the combination. #Chemical Properties. Action of Alkalies.#--Alkalies have a powerful action on wool, varying, of course, with the nature of the alkali, strength of solution and temperature at which the action takes place. An ammoniacal solution of copper hydroxide (Schweizer's reagent), has comparatively little action in the cold, but when hot it dissolves wool fairly readily. The caustic alkalies; sodium hydroxide, NaOH, or potassium hydroxide KOH, have a most deleterious action on wool. Even when very dilute and used in the cold they act destructively, and leave the fibre with a harsh feel and very tender, they cannot therefore be used for scouring or cleansing wool. Hot solutions, even if weak, have a solvent action on the wool fibre, producing a liquid of a soapy character from which the wool is precipitated out on adding acids. This action of alkalies has an important bearing on the scouring of wool, for if this operation be not carried out with due care there (p. 010) is in consequence great liability to impair the lustre and strength of this fibre. From microscopical examination this effect of alkalies is seen to be due to the fact that they tend to disintegrate the fibre, loosen and open the scales, this is shown by contrasting the two fibres A and B shown in figure 4, A being a normal wool fibre, B one strongly treated with an alkali. The alkaline carbonates have but little action on wool, none if used dilute and at temperatures below 120° F. [Illustration: Fig. 4.--Showing the Effects of Scouring Agents on the Wool Fibre. A. Unscoured Fibre. B. Badly Scoured Fibre.] Soap has practically no action on wool, and is therefore an excellent scouring material for wool. The carbonate of ammonia is the best and has the least action of the alkaline carbonates, those of potash and soda if used too strong or too hot have a tendency to turn the wool yellow, the carbonate of potash leaves the wool softer and more lustrous than the carbonate of soda. The influence of scouring agents on wool will be discussed in the chapter on cleansing wool fabrics in more detail. Caustic or quick-lime has a similar injurious action on the wool fibre as the caustic alkalies. #Action of Acids.#--Acids when dilute have but little influence on (p. 011) the wool fibre, their tendency is to cause a separation of the scales (see fig. 5) of the wool and so make it feel harsher. Strong acids have a disintegrating action on the wool fibre. There is a very considerable difference between the action of acids on wool and on cotton, and this difference of action is taken advantage of in the woollen industry to separate cotton from wool by the process commonly known as "carbonising," which consists in treating the fabric with a weak solution of hydrochloric acid or some other acid, then drying it; the cotton is disintegrated and falls away in the form of a powder, while the wool is not affected, sulphuric acid is used very largely in dyeing wool with the acid- and azo-colouring matters. [Illustration: Fig. 5.--Wool Fibre Heated with Acid.] Nitric acid affects wool in a very similar manner to the acids named above when used in a dilute form; if strong it gives a deep yellow colour and acts somewhat destructively on the fibre. Sulphurous acid (sulphur dioxide) has no effect on the actual fibre, but exercises a bleaching action on the yellow colouring matter which the wool contains, it is therefore largely used for bleaching (p. 012) wool, being applied either in the form of gas or in solution in water; the method will be found described in another chapter. Wool absorbs sulphur dioxide in large amount, and if present is liable to retard any subsequent dyeing processes. #Action of Other Substances.#--Chlorine and the hypochlorites have an energetic action on wool, and although they exert a bleaching action they cannot well be used for bleaching wool. Hot solutions bring about a slight oxidation of the fibre, which causes it to have a greater affinity for colouring matters; advantage is taken of this fact in the printing of delaines and woollen fabrics, while the woollen dyer would occasionally find the treatment of service. A paper by Mr. E. Lodge, in the _Journal of the Society of Dyers and Colourists_, 1892 (p. 41), may be consulted with advantage on this subject. Wool treated with chlorine loses its felting property, and hence becomes unshrinkable, a fact of which advantage is taken in preparing unshrinkable woollen fabrics. When wool is boiled with solutions of metallic salts, such as the sulphate of iron, chrome, aluminium and copper, the chlorides of tin, copper and iron, the acetates of the same metals, as well as with some other salts, decomposition of the salt occurs and a deposit of the metallic oxide on the wool is obtained with the production of an acid salt which remains in solution. In some cases this action is favourably influenced by the presence of some organic acid or organic salt, as, for examples, oxalic acid and cream of tartar (potassium tartrate), along with the metallic salt. On this fact depends the process of mordanting wool with potassium bichromate, alum, alumina sulphate, ferrous sulphate, copper sulphate, etc. The exact nature of the action which occurs is not properly understood, but there is reason for thinking that the wool fibre has the capacity of assimilating both the acid and the basic constituents of the salt employed. Excessive treatment with many metallic salts tends to make the (p. 013) wool harsh to the feel, partly owing to the scales being opened out and partly owing to the feel naturally imparted by the absorbed metallic salt. The normal salts of the alkaline metals, such as sodium chloride, potassium sulphate, sodium sulphate, etc., have no action whatever on the wool fibre. Wool has a strong affinity for many colouring matters. For some of the natural colours, turmeric, saffron, anotta, etc., and for the neutral and basic coal-tar colours it has a direct affinity, and will combine with them from their aqueous solutions. Wool is of a very permeable character, so that it is readily penetrated by dye liquors; in the case of wool fabrics much depends, however, upon the amount of felting to which the fabric has been subjected. If wool be boiled in water for a considerable time it will be observed that it loses much of its beautiful lustre, feels harsher to the touch, and also becomes felted and matted together. This has to be carefully guarded against in all dyeing operations, where the handling or moving of the yarns is apt to produce this unfortunate effect. After prolonged boiling the fibre shows signs of slight decomposition, from the traces of sulphuretted hydrogen and ammonia gases which it evolves. When wool is dried at 212° F. it assumes a husky, harsh feel, and its strength is perceptibly impaired. According to Dr. Bowman, the wool fibre really undergoes a slight chemical change at this temperature, which becomes more obvious at 230° F., while at about 260° F. the fibre begins to disintegrate. According to the researches of Persoz, however, temperatures ranging from 260° F. to 380° F. can be employed without any harm to the wool, if it has previously been soaked in a 10 per cent. solution of glycerine. When wool is heated to 212° F. (100° Cent.) it becomes quite (p. 014) pliant and plastic and may be moulded into almost any shape, which it still retains when cold. This fact is of much interest in the processes of finishing various goods, of embossing velvet where designs are stamped on the woven fabric while hot, and in the crabbing and steaming of woollen goods, making hats, etc. CHAPTER II. (p. 015) PROCESSES PREPARATORY TO DYEING, SCOURING AND BLEACHING OF WOOL. Wool scouring takes place at two stages in the process of manufacture into cloth. First, in the raw state, to free the wool from the large amount of grease and dirt it naturally contains; second, after being manufactured into cloth, it is again scoured to free it from the oil that has been added to the scoured raw wool to enable it to spin easily. This oiling is generally known as wool batching, and before the spun yarns or woven fabrics can be dyed it is necessary to remove it. Raw wool is a very impure substance, containing comparatively little wool fibre, rarely more than 50 to 60 per cent. in the cleanest fleeces, while it may be as low as 25 per cent. in the dirtiest. First there is a small quantity of dirt; there is what is called the suint, a kind of soapy matter, which can be removed by washing in hot water. This soap has for its base potash, while its acids are numerous and complex. The wool contains a fatty-like substance of the nature of wax, called cholesterine, and this imparts to the fatty matter, which be extracted from the wool fibre, very peculiar properties. Besides these there are several other bodies of minor importance, all of which have to be removed from the wool before it can be manufactured into cloth. Marker and Schulz give the following analysis of a good sample of (p. 016) raw wool:-- Moisture 23·48 per cent. Wool fat 7·17 " Wool soap (suint), soluble in water 21·13 " Soluble in alcohol 0·35 " Soluble in ether 0·29 " Soluble in dilute hydrochloric acid 1·45 " Wool fibre 43·20 " Dirt 2·93 " ------ 100·00 Two principles underlie the methods which are in use for this purpose. The first principle and the one on which the oldest method is based is the abstraction of the whole of the grease, etc., from the wool by means of an alkaline or soapy liquor at one operation. This cannot nowadays be considered a scientific method. Although it extracts the grease, etc., from the wool, and leaves the latter in a good condition for after processes, yet with it one might almost say that the whole of the soap or alkali used, as well as the wool grease itself, is lost as a waste product; whereas any good process should aim at obtaining the wool grease for use in some form or another. The second principle which underlies all the most recent methods for extracting the grease from the wool, consists in treating the fibre with some solvent like benzol, carbon bisulphide, petroleum spirit, carbon tetrachloride, etc., which dissolves out the cholesterine and any other free fatty matter which is in the wool fibre, leaving the latter in such a condition that by washing with water the rest of the impurities in the wool can be extracted. By distilling off and recondensing the solvent can be recovered for future use, while the wool fat can also be obtained in a condition to use for various purposes. This is rather a more scientific method than the old one, but it has not as yet come into extensive use. #Wool Scouring. Old Methods.#--In the early days of wool scouring (p. 017) this operation was done in a very primitive fashion, generally in a few tubs, which could be heated by steam or otherwise, and in which wool was worked by means of hand forks. These primitive processes are still in use in some small works, especially where the wool is dyed in the loose condition, but in all the large works machinery has been adopted, which machinery has been brought to a high state of perfection, and does its work very well, and without much attendant manual labour. The alkaline substances used in this process of scouring demand some notice. These comprise soda ash, soda crystals, caustic soda, silicate of soda, potash, caustic potash, soaps of various kinds, stale urine, ammoniacal compounds. Which of these may be used in any particular case depends upon a variety of reasons. Potash is the best alkaline agent to use. It agrees better with the fibre than any other, leaving it soft and elastic. Ammonia is the next best, but it does not take out the grease as well as the potash. Soda does not suit as well as potash, as it has a tendency to leave the fibre harsh in feel and somewhat brittle, yet on account of its being so much cheaper it is the most largely used. The use of silicate of soda cannot be recommended, as it has a great tendency to leave the fibre hard, which may be ascribed to the deposition of silica on the fibre. The caustic alkalies cannot be used as they have too solvent an action on the fibre. The carbonates, therefore, in the form of soda ash or potash, or pearl ash, are used, or better still, soap is used as it has a greater solvent action on the fatty matter of the wool than have the alkalies, and in this respect a potash soap is better than a soda soap. The character of the wool determines the alkali to be used; fine, long-stapled wools, which are usually very free from grease in excess, should always be treated with potash, or a potash soap, which will (p. 018) remove the whole of the grease from the wool, leaving the latter in a fine, soft, silky condition. Short-stapled wools can be treated with soap and a little soda ash, but too much of the latter is to be avoided. Coarse and greasy wools may be scoured with soap and soda ash, or other alkali which is almost necessary to remove the large amount of grease these wools contain. Practically the only alkaline products now in use are the various hard and soft soaps, and the carbonates of soda and potash in their various forms of soda ash, soda crystals, potashes, pearl ash, etc. Ammonia and its compounds are rarely used, while stale urine, which acts in virtue of the ammonia it contains has practically gone out of use. #Hand-Scouring.#--Wool scouring by hand is easily done and requires few appliances, simple tubs or vats of sufficient capacity in which steam pipes are placed, so that the scouring liquors can be heated up. The best temperatures to use are about 130° to 140° F., and it is not advisable to exceed the latter, as there is then some risk that the alkali may act on the fibre too strongly. The strength of the scouring liquor necessarily varies with the kind of wool being treated, and with the kind of alkaline product used; if soft, fine wools are being treated, then the liquor may be made with 1 to 2 lb. of soap to 10 gallons of water (if a mixture of soap and alkali is used, then it may contain from 1/4 to 1/2 lb. soda ash, and 1/2 lb. to 1 lb. of soap). For coarse, greasy wools these quantities may be increased by about one-half. The best plan of scouring by hand is to treat the wool in a tub with a scouring liquor for about half an hour, then to squeeze out the surplus liquor and to treat again in a new liquor for half an hour; this liquor may be used for a new batch of wool. The wool is often put into nets, and these are lifted up and down in the liquor so as to cause it to penetrate to every part of the wool. It is not advisable to work the wool about too much, otherwise (p. 019) felting might ensue and this must be avoided. The felting of the wool is one of the troubles of the wool-scourer and is often difficult to avoid, it is mostly brought about by excessive working of the wool during the process, and by the use of too high a temperature in the scouring bath. The remedies are obvious to the practical man, as little handling of the wool as possible, and at as low a temperature as possible. Still it is necessary to see that the scouring liquor penetrates to every part of the wool which is being treated. To ensure this, care must be taken not to scour too much at one time, so that the wool is loosely placed in the scouring tub, if placed loose in the latter, the workmen can by means of forks work it to and fro while in process of treatment. After the wool has been through these scouring liquors it is thrown on a scray to drain, and is next placed in cisterns which have perforated false bottoms. In these cisterns it is washed with cold water two or three times, the water being run off from the wool between each washing; it is then spread out in a room to dry. As a rule, a man can wash from 500 lb. to 600 lb. of wool in a day by this method. Another plan which is sometimes adopted so as to avoid handling the wool as much as possible, and thus prevent felting, is to place the wool in cages having perforated sides which will hold about 1 cwt. of wool. They are lowered by means of cranes into the washing liquors, and the wool in them is then worked for a quarter of an hour, when the cages and their contents are lifted out and the surplus liquor allowed to drain off. They are then lowered into the next bath, treated or worked in this, again lifted out and dropped into the wash waters. There is by this plan a saving of handling, and more wool can be got through in the same time, but it requires two men to work it. These hand processes are only in use in small works, having been (p. 020) replaced in all large works by mechanical methods described below. #Machine Scouring.#--Wool-scouring machinery has been brought to a high state of perfection by the successive efforts of many inventors, and by their means wool washing has been much simplified and improved. Wool-washing machinery is made by several firms, among whom may be mentioned Messrs. J. & W. McNaught, and John Petrie, Junior, Limited, both of Rochdale. [Illustration: Fig. 6.--Wool-washing Machine.] Fig. 6 shows one form of wool-washing machine. It consists of a long trough which contains the scouring liquor. In this machine the wool enters at the left-hand end, and is seized by a fork or rake and carried forward by it a short distance, then another rake seizes it and carries it further forward to another rake, and this to the last rake of the machine, which draws it out of the machine to a pair of squeezing rollers which press out the surplus liquor, and from these rollers the scoured wool passes to a travelling band for delivery from the machine. Sometimes the wool is not entered into the trough direct, but is put on a travelling apron which opens it and delivers it in a more open form into the trough. The movement of the forks causes some degree of agitation in the scouring liquor which facilitates the penetration of the liquor through the wool, and thus brings about a better scouring. After the wool has passed through the machine it is taken and run once more through the machine. Some scourers use the same liquor, but it is better to use fresh liquors, after which it is washed in the same machine with water two or three times. With a single machine there is some time and labour lost in transferring the wool from one end to the other between the separate treatments, and in large works where a great deal of wool is scoured it is usual to place three or four of these machines end to end. The first is filled with strong scouring liquor, the second with (p. 022) a weaker liquor, while the third and fourth contains wash waters, and the wool is gradually passed by the action of the machine through the series without requiring any manual aid. Between each machine it is passed through squeezing rollers as before, and finally emerges thoroughly scoured. A good plan of working in connection with such a series of machines is to have four as above, two washing machines and two soaping machines, the soap liquor is run through these in a continuous stream, entering in at the delivery end of the second soaper and passing out at the entering end of the first soaper. The wool as it first enters the machine comes into contact with rather dirty soap liquor, but this suffices to rid it of a good deal of loose dirt; as it passes along the machine it comes in contact with cleaner and fresher soap liquor, which gradually takes all grease and dirt out of it, and, finally, when it passes out it comes in contact with fresh liquor, which removes out the last traces of dirt and grease. In the same way it passes through the washers, being treated at the last with clean water. By this plan the scouring is better done, while there is some saving of soap liquor and wash water, for of these rather less is required than by the usual system. These are matters of consideration for wool scourers. The wool-washing liquors after using should be stored in tanks to be treated for recovery of the grease which they contain. The temperature of the scouring liquors should be about 100° F., certainly not more than 120° F., high temperatures are very liable to bring about felting, while tending to increase the harshness of the wool, particularly when soda is the agent used. By this method all the wool fat, suint, etc., of the wool find their way into the soap liquors. These were formerly thrown away, but they are generally treated with acid and the fat of the soap and wool recovered, under the name of wool grease or Yorkshire grease. (_Vide_ G. H. Hurst, (p. 023) "Yorkshire Grease," _Jour. Soc. Chem. Ind._, February, 1889.) The wool fat consists largely of a peculiar fat-like body known as cholesterine. This, however, is unsaponifiable, and cannot be made into soap; at the same time when it gets into, as it does, the recovered wool grease it spoils the latter for soap-making purposes. Cholesterine has some properties which make it valuable for other purposes; it is a stable body not prone to decomposition, it is capable of absorbing a large quantity of water, and it is on these accounts useful for medicinal purposes in the production of ointments, and it might be useful in candle-making. When it gets into recovered grease it cannot be extracted from it in an economical manner. The wool suint consists largely of the potash soaps of oleic and stearic acids. These two fatty acids find their way into the recovered wool grease but the potash salts are lost, while they would be valuable for various purposes if they could be recovered. Another form of wool-washing machine has a frame carrying a number of forks arranged transversely to the machine. The forks are by suitable gearing given a motion which consists of the following cycle of movements. The forks are driven forwards in the trough of the machine, carrying the wool along with them, they are then lifted out, carried back, and again allowed to drop into the machine, when they are ready to go forward again. Thus the forks continually push the wool from one end of the machine to the other. It is a common plan to have three machines placed end to end, so that the wool passes from one to the other; in a set of this kind the first machine should have a capacity of 1,500 gallons or thereabouts, the second 1,000 gallons, and the third 750 gallons. #Wool Scouring by Solvents.#--Of late years processes have been (p. 024) invented for the scouring of wool, either raw or spun by means of solvents, like carbon bisulphide, benzol, petroleum spirit, etc. Such processes are in a sense rather more scientific than the alkali processes, for whereas in the latter the grease, etc., of the wool and the oil used in batching it are practically lost for further use, and therefore wasted, being thrown away very often, although they may be partially recovered from the used scouring liquors, in the solvent processes the grease and oil may be recovered for future use for some purpose or other. The great objection to these processes is the danger that attends their use, owing to the inflammable character of the solvents. Several other objections may be raised, some of which are mechanical, and due to the want of proper machinery for carrying out the processes. There are many ways in which solvents may be applied, some are the subject of patents. It is not possible to describe the details of all these, but two of the most recent will be mentioned. In Singer's process, which was described in detail by Mr. Watson Smith some time ago before the Society of Dyers and Colourists, carbon bisulphide is used. The raw wool is placed between two endless bands of wire, and it is carried through a series of troughs containing bisulphide of carbon; during its passage through the troughs the solvent takes out the grease, and loosens the other constituents of the wool. After going through the bisulphide the wool is dried and passed through water which completes the process. The carbon bisulphide that has been used is placed in steam-heated stills, distilled off from the grease, condensed in suitable condensers, and used over again. In this process, with care, there is very little loss of solvent. The grease which is recovered can be used for various purposes, one of which is the manufacture of ointments, pomades, etc. The disadvantages of bisulphide are: (1) It tends after some time (p. 025) to cause the wool to acquire a yellow cast, due to the free sulphur which it contains, and which being left in the wool gradually causes it to turn yellow. By using redistilled bisulphide this defect may be avoided. (2) Another defect is the evil odour of the solvent. This, however, is less with redistilled bisulphide than with the ordinary quality, and with suitable apparatus is not insuperable. (3) Another defect is the volatility and inflammability of carbon bisulphide. On the other hand, bisulphide possesses the very great advantage of being at once heavier than, and insoluble in, water, and it can be, therefore, stored under water very much more safely than can any of the other solvents which are used. Burnell's machine has two troughs filled with benzoline. In these are arranged a large central roller round which are some smaller rollers. The wool passes round the large roller and is subjected to a number of squeezings in passing the smaller rollers. A current of the benzoline is continually passing through the machine. The whole is enclosed in a hood to avoid loss of solvent as far as possible. After passing through the benzoline trough the wool passes through a similar trough filled with water. Benzoline is better than carbon bisulphide in that there is no tendency on the part of the wool to turn yellow after its use, on the other hand it is more inflammable, and when it does take fire is more dangerous, and being lighter than water is not so readily and safely stored. Another feature is that it is not so completely volatile at steam temperatures, so that a little may be left in the grease and thus tend to deteriorate it. Coal-tar benzol, the quality known as 90's, would be better to use. The solvent processes are well worth the attention of wool scourers, all that is required for their proper development being the production and use of suitable machinery. After the raw wool has been scoured it is batched, _i.e._, it is (p. 026) mixed with a quantity of oil for the purpose of lubricating the wool to enable it more easily to stand the friction to which it is subjected in the subsequent processes of spinning and weaving by giving it greater pliability. For this purpose various kinds of oil are used. Olive oil is the principal favourite, the variety mostly used being Gallipoli oil. Ground-nut oil is also extensively employed, and is cheaper than olive. Oleic acid a by-product of the candle industry, is extensively used under the name of cloth oil, there is also used oleine, or wool oil, obtained by the distillation of Yorkshire grease. So far as merely oiling the wool is concerned there is not much to choose between these different oils, olive perhaps works the best and agrees best with the wool. Mineral oils have been and can be used either alone or mixed with the oils above mentioned, and so far as lubricating the wool is concerned do very well and are much cheaper than the fatty oils named above. The following are some analyses of various oils used as cloth oils which the author has had occasion to analyse. 1. 2. 3. 4. Specific gravity at 60° F. 0·9031 0·9091 0·6909 0·8904 Free fatty acid 55·02 64·42 51·52 68·05 Unsaponifiable oil 34·56 9·95 32·80 9·52 Saponifiable oil 10·32 25·32 15·68 12·43 ------ ------ ------ ------ 100·00 100·00 100·00 100·00 Nos. 1 and 2 are prepared from Yorkshire grease. The unsaponifiable matter in these is purely natural, it will be seen it varies within wide limits. Nos. 3 and 4 are made from the oleic acid of the candle factories, and the unsaponifiable matter is due to their containing mineral oil which has been added to them. So far as regards the object for which the wool is oiled, the mineral oils will answer almost as well as the fatty oils and with most (p. 027) satisfactory results from an economical point of view, for they are much cheaper. But this is not the only point to be considered. The oil has to be got out of the wool before the latter can be dyed. Now while the fatty oils can be easily removed, by treatment with soap, and they can be recovered along with the fat of the soap, mineral oils cannot be entirely removed from the wool, what remains in will interfere very much with the satisfactory dyeing of the wool, and what is got out finding its way into the covered wool grease, spoils this for soap making and other uses, so that on the whole what is gained in lessened cost of oiling is lost by the increased liability to defects in dyeing and consequently depreciation in value of the wool, and to decrease in value of the recovered grease. The amount of oil used varies from 7 per cent. with the best wools to 15 per cent. with shoddy wools. The scouring agents generally used are the same as those used in loose wool scouring, namely, carbonate of soda for coarse woollen yarns, soap and soda for medium yarns, and soap and ammonia for fine yarns. Prior to treating the yarns it is best to allow them to steep in hot water at about 170° F. for twenty minutes, then to allow them to cool. The actual scouring is often done in large wooden tubs, across which rods can be put on which to hang the hanks of yarn, and in which are placed steam pipes for heating up the bath. The best temperature to treat the yarn at is about 150° F.; too high a temperature must be avoided, as with increased heat the tendency to felt is materially augmented, and felting must be avoided. The hanks are treated for about twenty minutes in the liquor, and are then wrung out, drained, and again treated in new scouring liquor for the same length of time. After rinsing in cold water they are dried and finished. When the oiled wool has been spun into yarns, whether worsted or (p. 028) woollen, and passes into the hands of the dyer, it is necessary to remove from it all the oil before any dyeing operations can be satisfactorily carried out. This oil is removed by the use of soap and weak alkaline liquors, using these at about 110° to 120° F. The most common way is to have the liquor in a rectangular wooden tank, and hang the hank of yarn in by sticks resting on the edges of the tank; from time to time the hanks are turned over until all the oil has been washed out, then they are wrung out and passed into a tank of clean water to wash out the soap, after which the yarn is ready for dyeing. When the yarn is of such a character that it is liable to curl up, shrink and become entangled, it is necessary that it be stretched while it is being treated with the soap liquor; this is effected by a stretching apparatus consisting of two sets of rollers connected together by a screw attachment, so that the distance between the two sets of rollers can be varied. The hanks are hung between each pair of rollers, and can be stretched tightly as may be required. For pressing out the surplus liquor from the hanks of yarn a pair of squeezing rollers is used. #Scouring Woollen Piece Goods.#--Very often before weaving the yarns are not scoured to remove the oil they contain, as the weaving is more conveniently done with oily yarn than with a scoured yarn. Before dyeing the oil must be taken out of the pieces, and this can be conveniently done by scouring in a washing machine such as is shown in figures 7 and 8, using soap and soda liquors as before, and following up with a good rinse with water. [Illustration: Fig. 7.--Cloth-washing Machine.] The soap liquors used in scouring yarns and pieces become charged with oil, and they should be kept, and the oil recovered from them together with the fatty matter of the soap, by treatment with sulphuric acid. By subjecting the grease or fatty matter so obtained to a boil with caustic soda soap is obtained which may be again used in scouring (p. 029) wool. [Illustration: Fig. 8.--Cloth-washing Machine.] #Bleaching Wool.#--The wool fibre has to be treated very differently from cotton fibre. It will not stand the action of as powerful bleaching agents, and, consequently, weaker ones must be used. This is a decided disadvantage, for whereas with cotton the colouring matter is effectually destroyed, so that the bleached cotton never regains its original colour, the same is not the case with wool, especially with sulphur-bleached wool, here the colouring matter of the fibre is, as it were, only hidden, and will under certain circumstances return. The two materials chiefly used for bleaching wool are sulphur and peroxide of hydrogen. [Illustration: Fig. 9.--Sulphur Bleach House.] #Sulphur Bleaching.#--Bleaching wool by sulphur is a comparatively (p. 030) simple process. A sulphur house is built, the usual size being 12 feet high by 12 feet broad, and about 17 feet long. Brick is the most suitable material. The house should have well-fitting windows on two sides, and good tight doors at the ends (see fig. 9). Some houses have a (p. 031) small furnace at each corner for burning the sulphur, two of these furnaces are fitted with hoods, so that the sulphur gases can be conveyed to the upper part of the chamber, but a better plan, and one mostly adopted where the chamber is used for bleaching pieces, is to construct a false perforated bottom above the real bottom of the chamber, the sulphur being burnt in the space between the two floors. If yarn is being bleached the hanks are hung on wooden rods or poles in (p. 032) the chamber, while with pieces an arrangement is constructed so that the pieces which are stitched together are passed in a continuous manner through the chamber. When all is ready the chamber doors are closed, and the furnaces are heated, some sulphur thrown upon them, which burning evolves sulphur dioxide gas, sulphurous acid, and this acting upon the wool bleaches it. The great thing is to cause a thorough circulation of the gas through every part of the chamber, so that the yarn or pieces are entirely exposed in every part to the bleaching action of the gas. This is effected by causing the gas to pass into the chamber at several points, and, seeing that it passes upwards, to the ventilator in the roof of the chamber. Generally speaking, a certain quantity of sulphur depending upon the quantity of goods being treated is placed in the chamber and allowed to burn itself out; the quantity used being about 6 to 8 per cent. of the weight of the goods. After the sulphuring the goods are simply rinsed in water and dried. Sulphur bleaching is not an effective process, the colouring matter is not actually destroyed, having only entered into a chemical combination with the sulphur dioxide to form a colourless compound, and it only requires that the wool be treated with some material which will destroy this combination to bring the colour back again in all its original strength; washing in weak alkalies or in soap and water will do this. Another defect of the process lies in sulphur being volatilised in the free form, and settling upon the wool causes it to turn yellow, and this yellow colour cannot be got rid of. The goods must be thoroughly rinsed with water after the bleaching, the object being to rid the wool of traces of sulphuric acid, which it often contains, and which if left in would in time cause the disintegration of the wool. Sometimes the wool is washed in a little weak ammonia or soda (p. 033) liquor, but this is not advisable, as there is too much tendency for the colour of the wool to come back again, owing to the neutralising of the sulphur dioxide by the alkali. Instead of using the gas, the sulphur dioxide may be applied in the form of a solution in water. The goods are then simply steeped for some hours in a solution of the gas in water until they are bleached, then they are rinsed in water and dried. In this method it is important that the solution of the gas be freshly made, otherwise it is liable to contain but little sulphurous acid, and plenty of sulphuric acid which has no bleaching properties, but, on the other hand, is liable to lead to damage of the goods if it be not washed out afterwards. A better method of utilising the bleaching action of sulphur in a liquid form is to prepare a bath of bisulphite of soda, and acidify it with hydrochloric acid, then to enter the wool, stirring well for some time, and allowing it to steep for some hours, next to expose to the air for a while, and rinse as before. It is better to allow the wool to steep for about an hour in a simple bath of bisulphite, then enter into a weak hydrochloric acid bath for a few hours. The acid liberates sulphur dioxide in a nascent condition, which then exerts a more powerful bleaching action than if it were already free. Even with liquid bleaching the bleach is not any more perfect than it is with the gas bleaching; the colour is liable to come back again on being washed with soap or alkali, although there is a freedom from the defect of yellow stains being produced. Goods properly bleached will stand exposure to air for some considerable time, but those imperfectly bleached exhibit a tendency to regain their yellow colour on exposure to air. One fault which is sometimes met with in sulphur bleaching is a want of softness in (p. 034) the wool, the process seeming to render the fibre harsh. Washing in a little weak soft soap or in weak soda will remedy this and restore the suppleness of the wool; at the same time care must be taken that the alkaline treatment is not too strong, or otherwise the bleaching effect of the sulphur will be neutralised as pointed out above. #Bleaching Wool by Peroxide of Hydrogen.#--During recent years there has come into use for bleaching the animal fibres peroxide of hydrogen, or, as the French call it, oxygenated water. This body is a near relation to water, being composed of the same two elements, oxygen and hydrogen; in different proportions in water these elements are combined in the proportion of 1 part of hydrogen to 8 parts of oxygen, while in the peroxide the proportions are 1 of hydrogen to 16 of oxygen. These proportions are by weight, and are expressed by the chemical formulæ for water H_{2}O, and for hydrogen peroxide H_{2}O_{2}. Water, as is well known, is a very stable body, and although it can be decomposed, yet it requires some considerable power to effect it. Now the extra quantity of oxygen which may be considered to have been introduced into water to convert it into peroxide has also introduced an element of instability, the extra quantity of oxygen being ever ready to combine with some other body for which it has a greater affinity than for the water. This property can be utilised in the bleaching industry with great advantage, true bleaching being essentially a process of oxidation. The colouring matter of the fibre, which has to be destroyed so that the fibre shall appear white, is best destroyed by oxidation, but the process must not be carried out too strongly, otherwise the oxidation will not be confined to the colouring matter, but will extend to the fibre itself and disintegrate it, with the result that the fibre will become tendered and be rendered useless. Peroxide of hydrogen is a weak oxidiser, and therefore, although (p. 035) strong enough to destroy the colouring matter of the fibre is not strong enough to decompose the fibre itself. Hydrogen peroxide is sold as a water-white liquid, without any odour or taste. Its strength is measured by the quantity of oxygen which is evolved when one volume of the liquid is treated with potassium permanganate; the most common strength is 10 volume peroxide, but 30 and 40 volume peroxide is made. On keeping it loses its oxygen, so that it is always advisable to use a supply up as quickly as possible. Articles of all kinds can be bleached by simply placing them in a weak solution of the peroxide, leaving them there for a short time, then taking out and exposing to the air for some time. The best plan of applying peroxide of hydrogen is the following: Prepare the bleaching bath by mixing 1 part of peroxide with 4 parts of water. The strength can be varied; for those goods that only require a very slight bleach the proportions may be 1 to 12, while for dark goods the proportions first given may be used. This bath must be used in either a wooden or earthenware vessel. Metals of all kinds must be avoided, as they lead to a decomposition of the peroxide, and therefore a loss of material. To the bath so prepared just enough ammonia should be added to make it alkaline, a condition that may be ascertained by using a red litmus paper, which must just turn blue. Into the bath so prepared the well-scoured goods are entered and worked well, so that they become thoroughly saturated. They are then lightly wrung and exposed to the air for some hours, but must not be allowed to get dry, because only so long as they are moist is the bleaching going on; if they get dry the goods should be re-entered into the bath and again exposed to the air. If one treatment is not sufficient the process should be repeated. The peroxide bath is not exhausted, and only requires new material to (p. 036) be added to it in sufficient quantity to enable the goods to be readily and easily worked in the liquor. Any degree of whiteness may be obtained with a sufficient number of workings. No further treatment is necessary. It is found in practice that an alkaline bath gives the best results. Another plan of preparing the bleaching bath is to prepare a bath with peroxide and water as before, then add to a sufficient quantity of a solution of silicate of soda 4 parts of water to 1 of silicate of soda at 100° Tw., to make the bath alkaline. Into this bath the goods are entered and are then exposed to the air as before, after which they may be passed through a weak bath of sulphurous acid, being next well washed in water and dried. The advantage of bleaching with peroxide is that, as it leaves only water in the goods as the result of action, there is no danger of their becoming tendered by an after development of acid due to defective washing, as is the case with the sulphur bleach. The goods never alter in colour afterwards, because there is nothing left in that will change colour. Some bleachers add a little magnesia to the bath, but this is not at all necessary. #Bleaching with Peroxide of Soda.#--Peroxide of soda has come to the front of late for bleaching wool. With it a stronger bleaching bath can be made, while the product itself is more stable than peroxide of hydrogen, only it is needful to keep it in tightly closed metal vessels, free from any possibility of coming in contact with water or organic matter of any kind, or accidents may happen. In order to bleach 100 lb. of wool, a bath of water is prepared, and to this is added 6 lb. of sulphuric acid and then slowly 4 lb. of peroxide of sodium in small quantities at a time. Make the bath slightly alkaline by adding ammonia. Heat the bath to 150° F., enter the wool and allow to remain five to six hours, then rinse well and dry. If the (p. 037) colour does not come out sufficiently white repeat the process. THE CHLORINATION OF WOOL. The employment of chlorine in wool dyeing and wool printing has of late years received an impetus in directions previously little thought of. The addition of a little chlorine to the decoction of logwood has been recommended as increasing the dyeing power of the wool. Treating the wool with chlorine has a material influence in increasing its capacity for taking dye-stuffs, and although but little attention has been paid to this circumstance by wool dyers, yet among wool printers it has come largely into use, and enables them to produce fuller and faster shades than would otherwise be possible. The method involves the treatment of the wool first with an acid, then with a solution of a hypochlorite. The staple becomes soft and supple and assumes a silky character; in dyeing it shows a greater affinity for the dyes than it did previously. Although not deteriorated in strength, it almost entirely loses its felting properties. On account of this feature the process cannot be adopted for wool which has to be fulled, but it is of service where felting of the goods is to be avoided, for worsteds, underwear, woollen and half woollen hosiery, etc., in which the felting property that occurs on washing is rather objectionable. By the chloring of the wool the intensity of the shade dyed is increased to such a degree that when dyeing with Acid black, Naphthol black, Naphthol green, Nigrosine, Fast blue, Water blue, and some others dyed in an acid bath, but little more than half the dye used on unchlored wool is required, while with Induline, more even and intense shades are obtained than is otherwise possible. The operation of chlorination can be done either in one or two (p. 038) baths. The choice depends upon circumstances and the judgment of the dyer. The process by the two-bath method, with subsequent dyeing in the second or separate bath is (for 100 lb. of wool), as follows. The first bath contains, for light cloths, yarn, etc., from 3 to 4 lb. sulphuric acid, 168° Tw., and for heavier cloths and felt, where the penetration and equalisation of the colour is difficult, from 8 lb. to 10 lb. of acid. Generally speaking, a temperature of 170° to 175° F. is sufficient, although for heavy wool and for wool with poor dyeing qualities it is well to use the bath at the boil. The treatment lasts for half an hour, in which time the acid is almost completely absorbed. The second bath contains a clear solution of 10 lb. bleaching powder, which solution is prepared as follows. Dry bleaching powder of the best quality is stirred in a wooden vat with 70 gallons of water, the mass is allowed to stand, the clear, supernatant liquor is run into the vat and the sediment stirred up and again allowed to settle, the clear liquor being run off as before, and 5 gallons more water is run in. The clear liquors of these three treatments are then mixed together to form the chloring bath. Special care should be taken that no undissolved particles of the bleaching powder should be left in, for if these settle on the wool they result in too great a development of chlorine, which injures the wool. The goods after being in the acid bath are entered in this chlorine bath at a temperature of 70° F., which is then raised to the boil. If the acid bath has been strong, or been used at the boil, it is perhaps best to rinse the goods before entering into the chlorine bath. The hypochlorous acid disappears so completely from this bath that it may at once be used as the dye-bath, for which purpose it is only necessary to lift the goods, add the required amount of dye-stuff, re-enter the goods and work until the bath is exhausted, which generally happens when acid dyes are used. If a separate dye-bath be preferred, this is (p. 039) made and used as is ordinarily done. To perform all the operations in one bath the acid bath is made with from 3 to 4 lb. sulphuric acid, and the wool is treated therein for thirty minutes at 170° F., until all the acid has been absorbed. Then the bath is allowed to cool down to 70° or 80° F., the clear bleaching powder solution is added, the goods are re-entered, and the bath is heated to the boil. When all the chlorine has disappeared add the dye-stuff, and dye as directed above. In printing on wool the chlorination of the wool is a most important preliminary operation. For this purpose the cloth is passed for fifteen minutes at 170° F. through a bath containing 3/4 oz. sulphuric acid per gallon of water. Then it is passed through a cold bath of 3/4 oz. bleaching powder per gallon of water, after which the cloth is rinsed and dried and is then ready for printing. Another method of chloring the wool is to pass the goods through a bath made with 100 gallons of water, 2 gallons hydrochloric acid and 2 gallons bleaching powder solution of 16° Tw. As some chlorine is given off it is best to use this in a well-ventilated place. CHAPTER III. (p. 040) DYEING MACHINERY AND DYEING MANIPULATIONS. Wool is dyed in a variety of forms, raw, loose wool; partly manufactured fibre in the form of slubbing or sliver; spun fibres or yarns, in hanks or skeins and in warps, and lastly in the form of woven pieces. These different forms necessitate the employment of different forms of machinery and different modes of handling, it is evident to the least unobservant that it would be quite impossible to subject slubbing or sliver to the same treatment as yarn or cloth, otherwise the slubbing would be destroyed and rendered valueless. In the early days all dyeing was done by hand in the simplest possible contrivances, but during the last quarter of a century there has been a great development in the quantity of dyeing that has been done, and this has really necessitated the application of machinery, for hand work could not possibly cope with the amount of dyeing now done. Consequently there has been devised during the past two decades a great variety of machines for dyeing every description of textile fabrics, some have not been found a practical success for a variety of reasons and have gone out of use, others have been successful and are in use in dye-works. #Hand Dyeing.#--Dyeing by hand is carried on in the simplest possible appliances, much depends upon whether the work can be done at the ordinary temperature or at the boil. Figure 10 shows round and oval tubs and a rectangular vat much in use in dye-houses. These are (p. 041) made of wood, but copper dye-vats are also made, these may be used for all kinds of material--loose fibre, yarns or cloth. In the case of loose fibre this is stirred about either with poles or with rakes, care being taken to turn every part over and over and open out the masses of fibre as much as possible in order to avoid matting or clotting together. In the case of yarns or skeins, these are hung on sticks resting on the edges of the tub or vat. These sticks are best made of hickory, but ash or beech or any hard wood that can be worked smooth and which does not swell much when treated with water may be used. The usual method of working is to hang the skein on the stick, spreading it out as much as possible, then immerse the yarn in the liquor, lift it up and down two or three times to fully wet out the yarn, then turn the yarn over on the stick and repeat the dipping processes, then allow to steep in the dye-liquor. This is done with all the batch of yarn that is to be dyed at a time. When all the yarn has been entered into the dye-bath, the first stickful is lifted out, the yarn turned over and re-entered in the dye-liquor; this operation is carried out with all the sticks of yarn until the wool has become dyed of the required depth. In the case of long rectangular vats it is customary for two men, one on each side of the vat, to turn the yarns, each man taking charge of the yarn which is nearest to him. [Illustration: Fig. 10.--Dyeing-tubs and Vat.] Woven goods may be dyed in the tub or vat, the pieces being drawn in and out by poles, but the results are not altogether satisfactory, (p. 042) and it is preferable to use machines for dyeing piece goods. [Illustration: Fig. 11.--Dye-vat with Steam-pipe.] Plain tubs or vats, such as those shown in figure 10, are used for dyeing and otherwise treating goods in the cold, or at a lukewarm heat, when the supply of hot water can be drawn from a separate boiler. When, however, it is necessary to work at the boil, then the vat must be fitted with a steam coil. This is best laid along the bottom in a serpentine form. Above the pipe should be an open lattice-work bottom, which, while it permits the free circulation of boiling water in the vat, prevents the material being dyed from coming in contact with the steam pipe. This is important if uniform shades are to be dyed, for any excessive heating of any portion of the bath leads to stains being produced on the material in that part of the bath. Figure 11 shows a vat fitted with a steam pipe. That portion (p. 043) of the steam pipe which passes down at the end of the vat is in a small compartment boxed off from the main body of the vat, so that no part of the material which is being dyed can come in contact with it. A closed steam coil will, on the whole, give the best results, as then no weakening of the dye-liquor can take place through dilution by the condensation of the steam. Many dye-vats are, however, fitted with perforated, or as they are called, open steam coils, in which case there is, perhaps, better circulation of the liquor in the dye-vat, but as some of the steam must condense there is a little dilution of it. DYEING MACHINES. Dye-tubs and vats, such as those described above, have been largely superseded by machines in which the handling or working of the materials being dyed is effected by mechanical means. There have been a large number of dyeing machines invented, some of these have not been found to be very practical, and so they have gone out of use. Space will not admit of a detailed account of every kind of machine, but only of those which are in constant use in dye-works. #Dyeing Loose or Raw Wool and Cotton.#--Few machines have been designed for this purpose, and about the only successful one is _Delahunty's Dyeing Machine._--This is illustrated in figure 12. It consists of a drum made of lattice work which can revolve inside an outer wooden casing. The interior of the revolving drum is fitted with hooks or fingers, whose action is to keep the material open. One segment of the drum is made to open so that the loose cotton or wool to be dyed can be inserted. By suitable gearing the drum can be revolved, and the dye-liquor, which is in the lower half of the wooden casing, penetrates through the lattice work of the drum, and dyes (p. 044) the material contained in it. The construction of the machine is well shown in the drawing, while the mode of working is obvious from it and the description just given. The machine is very successful, and well adapted for dyeing loose or raw wool and cotton. The material may be scoured, bleached, dyed or otherwise treated in this machine. [Illustration: Fig. 12.--Delahunty's Dyeing Machine.] The Obermaier Machine, presently to be described, may also be used for dyeing loose cotton or wool. [Illustration: Fig. 13.--Obermaier Dyeing Machine.] #Dyeing Slubbing, Sliver or Carded Wool.#--It is found in practice that the dyeing of loose wool is not altogether satisfactory, the impurities they naturally contain interfere with the purity of the (p. 045) shade they will take. Then again the dyes and mordants used in dyeing them are found to have some action on the wire of the carding engine through which they are passed; at any rate, a card does not last as long when working dyed wools as when used on undyed cotton or wool fibres. Yet for the production of certain fancy yarns for weaving some special classes of fabrics it is desirable to dye the wool before it is spun into thread. The best plan is undoubtedly to dye the fibre after it has been carded and partly spun into what is known as slubbing, or sliver. All the impurities have been removed, the wool fibres are laid straight, and so it becomes much easier to dye. On the other hand, as it is necessary to keep the sliver or slubbing straight and level, no working about in the dye-liquors can be allowed to take place, and so such must be dyed in specially constructed machines, and one of the best of these is the _Obermaier Dyeing Machine_, which is illustrated in figure 13.--In (p. 046) the Obermaier apparatus dye-vat, A, is placed a cage consisting of an inner perforated metal cylinder, C, and an outer perforated metal cylinder, D; between these two is placed the material to be dyed. C is in contact with the suction end of a centrifugal pump, P, the delivery end of which discharges into the dye-vat A. The working of the machine is as follows: the slubbing or sliver is placed in the space between C and D rather tightly, so that it will not move about. Then the inner cage is placed in the dye-vat as shown. The vat is filled with the dye-liquor, which can be heated up by a steam pipe. The pump is set in motion, the dye-liquor is drawn from A to C, and in so doing passes through the material packed in B and dyes it. The circulation of the liquor is carried on as long as experience shows to be necessary. The dye-liquor is run off, hot water is run in to wash the dyed material, and the pump is kept running for some time to ensure thorough rinsing, then the water is run off, and by keeping the pump running and air going through a certain amount of drying can be effected. This machine works very well, and with a little experience constant results can (p. 047) be obtained. The slubbing or sliver may be scoured, bleached, rinsed, dyed, washed, soaped, or otherwise treated without removing it from the machine, which is a most decided advantage. [Illustration: Fig. 14.--Read Holliday's Yarn-dyeing Machine.] #Yarn Dyeing Machines.#--In figure 14 is given an illustration of a machine for dyeing yarn in the hank form, made by Messrs. Read Holliday & Sons, of Huddersfield. The illustration gives a very good idea of the machine. It consists of a wooden dye-vat, which can be heated by steam pipes in the usual way. Extending over the vat are a number of reels or bobbins, these are best made of wood or enamelled iron. These reels are in connection with suitable gearing, so that they can be revolved. There is also an arrangement by means of which the reels can be lifted bodily in and out of the dye-vat for the purpose of taking on and off the hanks of yarn. A reel will hold about 2 lb. of yarn. The working of the machine is simple. The vat is filled with the requisite dye-liquor. The reels which are lifted out of the vat are then charged with the yarn, which has been previously wetted out. They are then set in revolution and dropped into the dye-vat, and kept there until it is seen that the yarn has acquired the desired shade. The reels are lifted out and the hanks removed when the machine is ready for another lot of yarn. There are several makers of hank-dyeing machines of this type, and as a rule they work very well. The only source of trouble is a slight tendency for the yarn on one reel if hung loosely of becoming entangled with the yarn on other reels. This is to some extent obviated by hanging in the bottom of the hank a roller, which acts as a weight and keeps the yarn stretched and so prevents it flying about. To some makes of these machines a hank wringer is attached. [Illustration: Fig. 15.--Klauder-Weldon Dyeing Machine.] _Klauder-Weldon Hank-dyeing Machine._--This is illustrated in (p. 048) figure 15, which shows the latest form. It consists of a half-cylindrical dye-vat built of wood. On a central axis is built two discs or rod carriers, which can revolve in the dye-vat, the revolution being given by suitable gearing which is shown at the side of the machine. On the outer edge of the discs are clips for carrying rods on which one end of the hanks of yarn is hung, while the other end is placed on a similar rod carrier near the axle. The revolution of the discs carries the yarn through the dye-liquor contained in the lower semi-cylindrical part of the machine previously alluded to. (p. 049) At a certain point in every revolution of the discs the rods carrying the yarns are turned a little; this causes the yarn to move on the rods, and this motion helps to bring about greater evenness of dyeing. The most modern form of this machine is provided with an arrangement by means of which the whole batch of yarn can be lifted out of the dye-liquor. Arrangements are made by which from time to time fresh quantities of dyes can be added if required to bring up the dyed yarn to any desired shade. This machine works well and gives good results. Beyond the necessary labour in charging and discharging, and a little attention from time to time as the operation proceeds, to see if the dyeing is coming up to shade, the machine requires little attention. Many other forms of hank-dyeing machine have been devised. There is Corron's, in which an ordinary rectangular dye-vat is used. Round this is a framework which carries a lifting and falling arrangement that travels to and fro along the vat. The hanks of yarn are hung on rods of a special construction designed to open them out in a manner as nearly approaching hand work as is possible. The machine works in this way. The lifting arrangement is at one end of the vat, the hanks are hung on the rods and placed in the vat. Then the lifter is set in motion and moves along the vat; as it does so it lifts up each rod full of yarn, turns it over, opening out the yarn in so doing, then it drops it again in the vat. When it has travelled to the end of the vat it returns, packing up the rods of yarn in so doing, and this motion is kept up until the dyeing is completed. This machine is very ingenious. A type of machine which has been made by several makers consists of an ordinary rectangular dye-vat surrounded with a framework carrying a number of sets of endless chains, the links of which carry fingers. The hanks of yarn are hung on rods at one end of which is a tooth (p. 050) wheel that when in position fits into a rack on the side of the vat. The action of the machine is this, the hanks are hung on the rods and placed at the entrance end of the vat, by the moving of the chains it is carried along the vat and at the same time revolves, thus turning over the yarn, which hangs in the dye-liquor; when it reaches the opposite end of the vat, the rod full of yarn is lifted out, carried upwards and then towards the other end of the vat when it is again dropped into the dye-vat to go through the same cycle of movements which is continued until the yarn is properly dyed. #Piece Dyeing Machines.#--Wherever it is possible it is far more preferable to dye textile fabrics in the form of woven pieces rather than in the yarn from which they are woven. During the process of weaving it is quite impossible to avoid the material getting dirty and somewhat greasy, and the operations of scouring necessary to remove this dirt and grease has an impairing action on the colour if dyed yarns have been used in weaving it. This is avoided when the pieces are woven first and dyed afterwards, and this can always be done when the cloths are dyed in one colour only. Of course when the goods are fancy goods containing several colours they have to be woven from dyed yarns. The most common form of machine in which pieces are dyed is the jigger, commonly called the jig, this is shown in figure 16. It consists of a dye-vessel made long, sufficiently so to take the piece full width, wide at the top, narrow at the bottom. At the top on each side is placed a large winding roller on which the cloth is wound. At the bottom of the jig is placed a guide roller round which passes the cloth. In some makes of jigs there are two guide rollers at the bottom and one at the top as shown in the illustration, so that the cloth passes several times through the dye-liquor. In working the cloth is first wound on one of the rollers then threaded through the guide (p. 051) rollers and attached to the other winding roller. When this is done dye-liquor is run into the jig, and the gearing set in motion, and the cloth wound from the full on to the empty roller. With the object of keeping the piece tight a heavy press roller is arranged to bear on the cloth on the full roller. When all the cloth has passed from one roller to the other it is said to have been given "one end". The direction of motion is now changed and the cloth sent in the opposite direction through the jig and the piece has now received another "end". This alternation from one roller to the other is continued as long as is deemed necessary, much depending on the depth of colour which is being dyed, some pale shades may only take two or three ends, deeper shades may take more. When dyeing wool with acid colours which are all absorbed from the dye-liquor, or the bath is exhausted, it is a good plan to run the pieces several ends so as to ensure thorough fixation of the dye on the cloth. [Illustration: Fig. 16.--Dye-jiggers.] It is not advisable in working these jigs to add the whole of the dye to the liquor at the commencement, but only a part of it, then when one end is given another portion of the dye may be added, such (p. 052) portions being always in the form of solution. Adding dyes in powder form inevitably leads to the production of colour specks on the finished goods. The reason for thus adding the dye-stuff in portions is that with some dyes the affinity for the fibre is so great that if all were added at once it would be absorbed before the cloth had been given one end, and, further, the cloth would be very deep at the front end while it would shade off to no colour at the other end. By adding the dye in portions this difficulty is overcome and more level shades are obtained, but it is met with in all cases of jigger dyeing. It is most common in dyeing wool with basic dyes like Magenta, Auramine, (p. 053) Methyl Violet or Brilliant Green, and with acid dyes like Acid Green, Formyl Violets, Azo Scarlet or Acid Yellow. [Illustration: Fig. 17.--Dye-jigger in Section.] Some attempts have been made to make jiggers automatic in their reversing action, but they have not been successful owing to the greatly varying conditions of length of pieces, their thickness, etc., which have to be dyed, and it is next to impossible to make all allowances for such varying conditions. [Illustration: Fig. 18.--Wince Dye Beck.] In figure 17 is shown the jig in section, when the working of the machine can be more easily traced. #The Jig Wince or Wince Dye Beck.#--This dyeing machine is very largely used, particularly in the dyeing of woollen cloths. It is made by many makers, and varies somewhat in form accordingly. Figures 18 to 21 show three forms by different makers. In any make the jig wince or wince dye beck consists of a large rectangular, or in some cases (p. 054) semi-cylindrical, dye-vat. Probably the best shape would be to have a vat with one straight side at the front, and one curved side at the back. [Illustration: Fig. 19.--Wince Dye Beck.] In some a small guide roller is fitted at the bottom, under which the pieces to be dyed pass. Steam pipes are provided for heating the dye-liquors. The beck should be fitted with a false bottom, made of wood, perforated with holes, or of wooden lattice work, and under which the steam pipes are placed. The object being to prevent the pieces from coming in contact with the steam pipes, and so (p. 055) preventing the production of stains. Above the dye-vat and towards the back is the wince, a revolving skeleton wheel, which draws the pieces out of the dye-vat at the front, and delivers them into it again at the back. The construction of this wince is well shown in the drawings. The wince will take the pieces full breadth, but often they are somewhat folded, and so several pieces, four, five or six, can be dealt with at one time. In this case a guide rail is provided in the front part of the machine. In this rail are pegs which serve to keep the pieces of cloth separate, and so prevent entanglements. The pieces are stitched end to end so as to form an endless band. When running through the vat they fall down in folds at the back part of the beck, and are drawn out from the bottom and up in the front. Each part thus remains for some time in the dye-liquor, during which it necessarily takes up the dye. [Illustration: Fig. 20.--Plush Fabric Dyeing Machine.] Figures 18 and 19 show forms of these wince dyeing machines, constructed of wood, and very largely used in the dyeing of woollen cloths. They are serviceable forms, and give very good results, being suitable for all dyes. Figure 20 is a form of machine better adapted than the preceding (p. 056) for the dyeing of plush fabrics. In this kind of cloth it is important that the pile should not be interfered with in any way, and experience has shown that the winces of the form shown in figures 18 and 19 are rather apt to spoil the pile; further, of course, plush fabrics are dyed full breadth or open. In the wince now shown all troubles are (p. 057) avoided, and plush fabrics can be satisfactorily dyed in them. [Illustration: Fig. 21.--Copper Cased Dye Beck. Mather & Platt.] Figure 21 shows a dye-bath built of iron, cased with copper, suitable for dyeing most colours on woollen cloths. [Illustration: Fig. 22.--Read Holliday's Hawking Machine.] In the jig and wince dyeing machines the pieces necessarily are for a part of the time, longer in the case of the jigger than in that of the wince, out of the dye-liquor and exposed to the air. In the case of some dyes, indigo especially, this is not desirable, and yet it is advisable to run the cloth open for some time in the liquor so as to get thoroughly impregnated with the dye-liquor. The so-called hawking machine, figure 22, is an illustration of Read Holliday's hawking machine, made by Messrs. Read Holliday & Sons, of Huddersfield. There is the dye-vat as usual; in this is suspended the drawing mechanism, whose construction is well shown in the drawing. This is a pair of rollers driven by suitable gearing, between which the cloth passes, and by which it is drawn through the machine. A small roller ensures the cloth properly leaving the large rollers, (p. 058) then there is a lattice-work arrangement over the pieces are drawn. In actual work the whole of this arrangement is below the surface of the dye-liquor in the vat. The piece to be dyed is threaded through the machine the ends stitched together, then the arrangement is lowered into the dye-vat and set in motion, whereby the cloth is drawn continuously in the open form through the dye-liquor, this being done as long as experience shows to be necessary. This hawking machine will be found useful in dyeing indigo on wool, in mordanting and dyeing wool with the Alizarine series of dyes. CHAPTER IV. (p. 059) THE PRINCIPLES AND PRACTICE OF WOOL DYEING. The various methods which are used in dyeing wool have, of course, underlying them certain principles on which they are based, and on the observance of which much of the success of the process depends. Sometimes these principles are overlooked by dyers, with the result that they do not get good results from their work. It must be obvious to any person with any technical knowledge that all processes of dyeing either wool or silk, or cotton or any other fibre, must take into consideration the properties of the fibre on the one hand, and that of the dye-stuff on the other. Wool must be treated differently from cotton, a process of dyeing which gives good results with the latter fibre would lead to nothing but disastrous effects with wool or silk; on the other hand, processes are used in the dyeing of wool which could not be possibly used for cotton on account of the very different properties of the fibre. A few words as to the properties of wool as far as they relate to the methods of dyeing may be of use. Wool has the property of resisting the action of acids in a great degree, so that it may be treated with even strong acids with impunity. On the other hand, alkalies and alkaline solutions have strong action on it; the caustic alkalies rapidly dissolve wool, and their use must be avoided in all cases of dyeing this fibre. The carbonates of the alkalies have not so strong an action, and therefore may be used in moderation; nevertheless, (p. 060) too strong solutions of these should not be used. Soap has no disintegrating action on wool, and soap solutions may be used whenever necessary for cleansing or dyeing wool. Ammonia has no action on wool, and it may be used in place of soap if desired. There is one feature of wool that must be alluded to here, and that is its felting property. When wool is boiled with water and is handled a good deal, the fibres clot or felt together into a firm coherent mass. This should be avoided as much as possible, and when wool is cleansed and dyed in the loose condition it is absolutely necessary that every care be taken to avoid felting. This condition is much influenced by the temperature and the condition of the bath in which the wool is being treated, too high a temperature or too prolonged a treatment tends to increase the felting, therefore in dyeing wool prolonged treatment at the boil must be avoided. Further, the condition of the bath has some influence on this point; it is found that an alkaline bath tends to considerably increase the felting properties of the wool, and on this account dyers invariably avoid the use of both the caustic and carbonated alkalies. Strong soap liquors have also some influence in the direction of increasing the felting, therefore soap should not be used if it can possibly be done without. Ammonia has not so strong a felting action as the other alkalies. Acids, on the other hand, exert a retarding action on the felting of the wool, and this is a matter of some interest and importance in the dyeing of wool, as an acid condition of the bath is necessary for dyeing by far the great majority of colouring matters on this fibre. Alkaline salts, such as Glauber's salt and common salt, exert little or no influence on this felting property, and can be added to dye-baths with impunity, and in many cases with good effect, so far as the quality of dyeing is concerned. So far as the properties of the wool are concerned, it is seen (p. 061) that an acid condition of the dye-bath will work better than an alkaline condition, and wherever it is possible to use acids such should be added. What has been said in regard to wool is equally true of all fibres derived from animals in the same way as wool is, such as horse-hair, fur of rabbits, hares and other animals, although, of course, there are some minor differences between different furs in their resistance to the action of acids and alkalies. The next feature that influences the methods of dyeing wool is the varying properties of the dye-stuffs, or colouring matters. It is obvious that those which, like Magenta or Saffranine, have a strong affinity for the wool fibre must be dyed differently from those which, like Alizarine and Gambine, have no direct affinity for the wool fibre, and, further, which require the aid of mordants before they can be dyed, and on the character of which mordants the colour that is fixed on the fibre depends. The dye-stuffs, independently of the question whether they be derived from natural sources or be of artificial origin, may be roughly divided into five groups, some of which may also be subdivided again as will be shown later on. These groups may be named the (1) Neutral, (2) Basic, (3) Acid, (4) Mordant, and (5) Indigo dye-stuffs. The first two classes are practically dyed in the same way; but as there is a great difference in the chemical composition of the colouring matters comprised in them, it will be best to consider them separately. _First Method_.--This method is used in applying the now large and increasing group of azo dye-stuffs, which are characterised by being able to dye unmordanted cotton from a simple boiling bath. The dye-stuffs that are applied by the method now to be described include such as Benzopurpurine, Chrysamine, Chrysophenine, Titan red, Titan yellow, Benzo brown, Diamine red, Diamine brown, Diamine blue, (p. 062) Congo blue, Congo red, etc. The dyeing is done in a bath at the boil. If the bath contained only the dye-stuffs there would be a liability for the dyeing to be uneven, to prevent which a saline compound, such as salt, is added. Taking it all round, salt is the best body to add as it suits all colours very well indeed. Then come Glauber's salts; borax and phosphate of soda can also be used, but, owing to their slight alkaline properties, they are not so good as the neutral salts, like the two first named. When these colouring matters are dyed on cotton some of them dye best in a bath containing potash or soda, but these bodies, for reasons previously pointed out, are not available in wool dyeing, and should never be used. Wool dyes best in a slightly acid bath, and this may be taken advantage of in dyeing the yellows and blues of this group by adding a small quantity of acetic acid. The reds, as a rule, are affected by acids, and, therefore, it is not possible to use an acid bath with Benzopurpurine, Congo red, with the possible exception of the Titan reds and scarlets, Diamine scarlet, Benzo fast scarlet, Purpuramine, which are faster to acetic acid than the other reds of this class of dye-stuffs. Probably the best plan of dyeing these colours is to first heat the bath to about 160° F., then enter the goods, and turn over two or three times to ensure that they are thoroughly impregnated with dye-liquor. The bath is now raised to the boil, and, steam being turned off, the goods are handled without further steam until the desired shade is obtained. Another plan is to enter the goods when the bath is at about 150° F., and, after raising to the boil, to work for half to one hour at that heat; but the plan first described gives rather better results, and is far preferable. The dye-baths, as a rule, are not completely exhausted, except when very pale shades are being dyed; in no case is it necessary to throw the dye-bath away, but simply to add the required amount of dye-stuff for a new batch; (p. 063) with those colouring matters which are not entirely exhausted from the bath a smaller amount, generally about three-fourths only, is required to be added, with about one-third the quantity of salt which was added to the first bath. Of course it is not advisable to keep the same bath or liquor in work always, but after about twenty or thirty batches of goods are dyed to throw it away and start a fresh liquor. As a rule it will be found that these dye-stuffs are more thoroughly taken up from the bath than is the case in dyeing cotton; thus often with the same amount of dye-stuff in proportion to the material used the wool will dye rather a deeper shade than will cotton. In some cases, especially with the blues and violets, the shade is greatly different on wool from what it is on cotton, being generally redder and much stronger. (See the chapter on Union Dyeing.) While the shades are somewhat faster to light on wool than they are on cotton, they are no faster to soaping and in some cases not so fast. What may be the function of the salt, or other such added substance, is not very clear, probably it plays the same part as to similar bodies in dyeing the basic dye-stuffs. The dye-stuffs which are referred to above are all derived from coal-tar, and in the recipes which follow many examples of their use will be found. There are but few natural dye-stuffs that have any direct affinity for wool. Turmeric, saffron, anotta, are about the only representatives, and these are not of much importance in wool dyeing by themselves, although they are sometimes used in conjunction with other natural dye-stuffs, when they are applied by a process which is adapted more especially for the other dye-stuff which is used. _Second Method_.--The method of wool dyeing now being dealt with does not differ essentially from that described above, but as it is applied to quite a different class of dye-stuffs it is thought better to consider it as a second method. The dye-stuffs made use of in (p. 064) this method are what are called the basic coal-tar colours, and it may be remarked in passing that there are no natural colouring matters having the same properties. These dye-stuffs are derived from a number of so-called colour bases, such as Rosaniline, Pararosaniline, Methylrosaniline, Phenyl-rosaniline, and Auramine base. Many of these are colourless bodies containing the Amidogen group NH_{2}, which imparts to them basic properties enabling them to combine with solids to form salts, and these salts have a strong colouring power. They form the commercial dye-stuffs Magenta, Saffranine, Thioflavine T, Auramine, Benzoflavine, Brilliant green, Methyl violet, etc., and these are salts (usually the hydrochloride) of colour bases. All these basic dye-stuffs have strong affinity for the wool fibre, and will immediately combine with it, dyeing it in colours which resist washing, etc., to a considerable extent, although there are great differences between the various members of the group in this respect. It has been shown that what takes place in dying wool with these colouring matters is that the colour base combines with the fibre the acid of the dye-stuff remaining in the dye-liquor. Although it is possible to dye wool with the basic dyes from a plain bath containing water only, yet the results are not satisfactory, especially when working on a large scale; and for dyeing pale shades especially, the affinity of the dye-stuff for the fibre is so great that the first portions of the goods which are entered into the dye-bath have a great tendency to absorb all the dye-stuff, or the larger proportion of it, so that uneven dyeing is the result, one end of the piece of cloth being darker than the other end. This defect is particularly accentuated when pale tints are being dyed, the colouring matter being completely absorbed before all the goods are entered into the bath, but it may be remedied by adding the dye-stuff to the bath in small quantities at intervals during the process of dyeing. The (p. 065) best and most satisfactory method, however, is to add to the bath 10 per cent. of the weight of the wool of Glauber's salt, or some other neutral alkaline salt, which addition almost entirely prevents any defect of uneven dyeing. How these assistant mordants act is somewhat uncertain, the explanation generally given is that they exert a slightly solvent action on the dye-stuff, and so prevent it from going upon the fibre too readily. This is scarcely an adequate explanation, but in want of a better it will have to stand. The affinity of the basic dyes for wool increases with increase of temperature. This is a property that has an important bearing on the method of dyeing, and to any person who pays some attention to theory in its practical applications it indicates the most rational method of working, which is to enter the goods into the bath cold, or, at the most, at a hand heat, then, after working a short time to get the goods thoroughly impregnated with the dye-stuff, to gradually raise the temperature to the boil and work for from half an hour to an hour longer, even if before this time the dye-bath be exhausted. The reason for giving a fair length of time in the bath is to get the colour properly fixed on the fibre. The combination of the dye-stuff and the fibre is a chemical one, and, as stated above, the dye-stuff has to be decomposed so that the base may combine with the essential constituent of the wool fibre, while it is obvious that this decomposition and then the union of the colour base with the wool must take time, and as it is effected more easily and completely at the boiling point, it is advisable to work the goods in the bath so as to fully insure that they are given the necessary time for the chemical change to take place. The dye-bath is generally completely exhausted of colour, but if fairly clean it need not be thrown away, but used for another batch of wool by simply adding more Glauber's salt and dye-stuff. After a (p. 066) time the bath gets too dirty to used, when it may be thrown away, and a new dye-liquor made up. In dyeing for pale shades it is best to add the dye-stuff in small quantities at intervals during the process of dyeing, and to run the goods quickly through the bath, so as not to give the dye-stuff too much opportunity to become absorbed by a portion of the goods only. Working according to the hints given above, the dyeing of wool with the basic coal-tar colours may be carried out in a very satisfactory manner. _Third Method_.--This method consists in dyeing the wool in a bath containing the dye-stuff, a little acid (usually sulphuric) with the addition of Glauber's salt, or some other alkaline salt, the essential feature or principle being that the bath is an acid one. This method is applicable to the large group of azo dye-stuffs derived from coal tar, and also to the acid dyes prepared from the basic coal-tar colours by the process of sulphonation. It is also used to apply indigo carmine to wool, probably the only good example of a natural dye-stuff applied by this process. Most of the natural colouring matters, such as logwood and fustic, belong to another group of dye-stuffs. The simple azo dyes are combinations of two or more organic bases, united together by a peculiar and characteristic group of nitrogen atoms. Such azo colours are, however, insoluble in water, and therefore they cannot be used in dyeing and textile colouring, although the firm of Messrs. Read Holliday & Sons years ago patented a process whereby these insoluble azo colours could be developed on the cotton fibre direct, and thus fabrics made from that fibre could be dyed in fast colours. When these insoluble azo colours are treated with sulphuric acid they are converted into sulpho acids, undergoing what is called sulphonation, an operation of the greatest (p. 067) importance and value in the preparation of dye-stuffs. The preparation of indigo extract or indigo carmine from indigo is also a case of sulphonation. The sulpho-acids of the azo colours, of the basic dyes, and of indigo are usually insoluble in water, although there are great differences in their properties in this respect. They will combine with bases such as soda, calcium and potash to form salts which are soluble in water, and it is usually in the form of sodium salts that these azo and acid dye-stuffs are sold to the dyer and calico printer. It is this power of combination with bases that makes them of value in wool dyeing. As Knecht and other authorities have pointed out, the wool fibre contains a basic principle capable of combining with acid bodies, and in wool dyeing with the colouring matters under discussion, this combination occurs between the sulpho-acid of the dye-stuff and the basic principle of the wool fibre. This points to the fact that the dye-stuffs of this class do not combine with the wool in the form in which they are supplied to the dyer as sodium salts, which is shown by a property that many if not all of them possess, of not dyeing the wool fibre in a neutral bath. If a piece of wool be immersed in a solution of, say, a scarlet or indigo extract, which is neutral it is not dyed. The dye-liquor may penetrate thoroughly throughout the fabric, but if the piece of wool be lifted out, and allowed to drain, nearly all the liquor will drain away, and leave the wool nearly if not quite white, showing that the dye-stuff in the form in which it is sold has no affinity for the wool fibre. If now a few drops of sulphuric acid be added to the dye-liquor the wool will become dyed. The sulphuric acid liberates the free sulpho-acid of the dye-stuff, and this is now in a form to combine with the wool fibre, which it does. This is the fundamental principle underlying the acid method for dyeing wool with the acid group of colouring matters. The practical application of the principle laid down above is a (p. 068) matter of simplicity compared with the other methods of dyeing. The composition of the bath is given above. It is best to enter the wool at from 150° to 160° F. and then to raise the temperature slowly to the boil. This method of proceeding gives time for the free colour acid of the dye to be liberated from the dye-stuff on the one hand, and for its combination with the wool fibre on the other. In dyeing pale tints with acid dye-stuffs it is a good plan not to add the acid until after the goods have been entered into the bath and worked for a short time to enable them to become impregnated with the dye-liquor; the acid may be then added, and the dyeing may be finished as usual. By this plan of working more even dyeings can be obtained than by simply entering the goods direct into an acidified dye-liquor. Any kind of acid may be employed, but generally sulphuric acid is used, partly because it is cheap, and partly because it is the commonest acid known. Acetic acid is also used in many cases. _Fourth Method_.--We now come to the fourth method of dyeing wool. Strictly, perhaps, it is not a single method, but a group of methods, which are used to supply a certain class of dye-stuffs to the wool fibre; but as the governing principle depends upon the peculiar property of the dye-stuffs now to be noticed, which underlies all the variations of the process of dyeing, it has been thought better to speak of the fourth method rather than to subdivide further, in which case the fundamental principle might be lost sight of. The class of dye-stuffs included in the fourth group was named by Bancroft the "adjective" group, because they require the aid of a second body, named the mordant, to properly develop and to fix the colour of the dye-stuff on the wool. It is sometimes known as the "mordant dye-stuff" class, and this is perhaps its best name. This (p. 069) group of colouring matters comprises dye-stuffs of both natural and artificial origin, the latter of which are getting very numerous and valuable, and bid fair to displace the natural members of the group. With but few exceptions the adjective dye-stuffs are not colouring matters of themselves, _i.e._, they will not dye wool or other fibres by themselves. Some are coloured bodies, such as fustic, logwood, Persian berries, Anthracene yellow, etc., but many are not so, and some possess but little colour, which, moreover, gives no clue to the colours that can be developed therefrom. All the colouring matters of this class possess either a distinctively acid character, or belong to the class of phenols, which, while not being true acids, still possess weak acid functions that enable them to combine with bases like acids. These bodies have the property of combining with bases and metallic oxides, such as soda, potash, iron, alumina, chrome, tin, nickel, cobalt, etc., forming a series of salts. Those of soda and potash are usually soluble in water, while those of the other metals are insoluble, and are usually of strong colour. It is on this property of forming these insoluble coloured bodies, colour lakes, as they are called, that the value of the adjective dye-stuffs in dyeing depends. The group of adjective colouring matters may be subdivided into two divisions, not depending upon any differences in the mode of application, but upon certain differences in the results they give. Perhaps the best example of an adjective dye-stuff is Alizarine. This body has a faint red colour, but of itself possesses absolutely no colouring power. When, however, it is brought into combination with such metallic oxide as alumina, iron and chrome, then it forms coloured bodies, the colour of which varies with the metal with which it is in union, thus with alumina, it is a bright red; with iron, a dark violet, almost black; with chrome, a deep red; with tin, a (p. 070) scarlet; and so on. This is a representative of the true adjective dyes, which comprise most of the so-called Alizarine dye-stuffs, and logwood, fustic, and most of the natural dye-stuffs. Another division of the group includes a few colouring matters of recent introduction, like Azo green, Alizarine yellow, Galloflavine, Anthracene yellow, Flavazol, etc., which, while forming insoluble colour lakes with metallic oxides, do not give different colours with different metals. This class of dye-stuffs, owing to their forming these insoluble colours, gives really fast colours, capable of resisting lengthened exposure to light and air, and resisting washing, acids and alkalies. Of course there are differences between the various members of the group in this respect, and even the resisting power of an individual member depends a good deal on the metal with which it is combined, and the care with which the process of dyeing has been carried out. In the dyeing of these adjective dye-stuffs, upon the various fibres, and on wool in any particular, the object is to bring about in any convenient way the formation on the fibre of the metallic combination of the colouring principle and the mordant, and it is obvious that if a satisfactory result is to be obtained, then this must be done in a very thorough manner. There are three ways in which this combination of colouring principle and mordant may be brought about in dyeing wool with these bodies, we may either mordant the wool first, and then apply the dye-stuff, or we may impregnate the wool with the dye-stuff first, and then fix or develop the colour afterwards, or, lastly, we may carry on both operations in one process. Each of these methods will now be discussed, and their relative advantages pointed out. The mordanting method is one of the most generally useful. It consists in first causing a combination of the metal with the wool fibre. (p. 071) This is carried out by boiling the wool in a solution of the metal, such as bichromate of potash, chrome alum or chrome fluoride when chrome is to be used as a mordant, with alum or sulphate of alumina when alumina is required to be deposited on the fibre, and with copperas when iron is to be the mordant. It is best to add a little oxalic acid, cream of tartar, or tartaric acid to the mordanting bath, which addition helps in the decomposition of the metallic salt by the wool fibre, and the deposition of the metallic oxide on the wool. With bichromate of potash, sulphuric acid is often used, much depending upon the character of the mordant required. Some dye-stuffs, such as logwood for blacks, work best when the wool is mordanted with chromic acid, which is effected when sulphuric acid is the assistant mordant. Other dye-stuffs, such as fustic, Persian berries and Alizarine yellow, are best dyed on a basic chrome mordant, which is effected when tartar or oxalic acid is the assistant mordant used, or when some other form of chrome compound than bichrome is employed. The actual mordanting is done by boiling the wool in a bath of the mordant, the quantity of which should be varied according to the particular mordant that is being employed and to the quantity of dye-stuffs which is to be used. It is obvious that for a fixing deep shade of, say, Alizarine on the wool, a larger quantity of mordant will be required than to fix a pale shade; sometimes this point is overlooked and the same amount of mordant employed for pale or deep shades. The best plan of carrying out the mordanting is to enter the wool in the cold bath or at a hand heat, and then raise to the boil and continue the boiling for one hour; of course the goods should be kept turned over during the process to facilitate the even mordanting of the wool. A great deal of the success of dyeing with the dye-stuffs now under consideration depends upon the efficiency with which the (p. 072) mordanting has been carried out. If this is at all unevenly done then no amount of care in the succeeding dyeing process will lead to the development of an even dyeing. After the mordanting is finished the goods should be rinsed with water, but it is not necessary to dry them. The next stage in the process is the actual dyeing operations, which is done by immersing the mordanted wool in a bath of the dye-stuff or mixture of dye-stuffs. The fundamental principle is to bring about the combination between the colouring principle of the dye-stuff and the metallic oxide which has been deposited on the wool in the previous mordanting process. As neither of these bodies, however, is very energetic it follows that the action must be a slow one, and, therefore, time is a highly important factor in the dyeing of wool by the mordanting process. The combination between the dye-stuff and the mordant is influenced also by temperature, and is most active at the boiling point of water. It is, therefore, needful to conduct this operation at that temperature, but it would be a wrong way to introduce the mordanted material into a boiling bath of the dye-stuff; nothing would conduce to uneven dyeing so much as that course. The best method of working, which, moreover, is most particularly applicable to the series of Alizarine dye-stuffs, is to enter the goods in a cold bath of the dye-stuff, and to work them for a short time to get them thoroughly impregnated, a condition which is essential if even dyeing is the goal aimed at, then to raise the temperature of the bath gradually to the boil, the goods being in the meantime well worked. The dyeing is continued for from one to one and a half hours at the boil. It is important in dyeing by this process, especially when using Alizarine, to keep the temperature of the bath as uniform as possible, and the goods well worked. Alizarine, and some other members of (p. 073) this class, are rather sensitive to heat, and if a dye-vat be hot at the bottom and cold at the top uneven dyeing is sure to be the result; this is due to the greater affinity of the Alizarine for the mordant at the high than at the low temperature, and thus more is fixed on to the wool. The remedy for this is to so construct the heating arrangements of the vat that the temperature shall be as uniform as possible, while the goods should be kept continually turned over, and every portion of them brought into intimate contact with the dye-liquor. The continuance of the dyeing operations for one and a half to two hours after the vat has reached the boil is necessary to properly develop and fix the colour on the fibre; a short boil leaves the goods of a poor shade, without any solidity about it, and the colour is loose, while a longer boil brings up a solid shade and a fast colour. Although it is not absolutely necessary to add any acid to the dye-bath during the dyeing operations, yet as the Alizarines and most of this class of dye-stuffs dye better in a slightly acid bath it is advisable to add a small quantity of acetic acid, say about one pint to every 100 lb. of goods; this serves to correct any alkalinity of the water, which may be due to its containing any lime. Dye-stuffs of the acid class, such as indigo extract, Cloth red, Acid magenta, etc., may be used along with the Alizarine dye-stuffs, in which case the addition of acid to the dye-bath becomes necessary, but too great an excess of acid should be avoided, as it interferes somewhat with the dyeing of the mordant dyes. This is by far the best and most generally used method of applying these mordant dyes. It is not a costly process, being indeed economical, as it only requires just the right amounts of drugs and dye-stuffs, and there is the minimum loss of material in the mordanting and dye-baths. Shades can be brought up with the greatest ease, although it is well in the dyeing to add rather less dye-stuff than is (p. 074) actually required, and to add more when it is seen how the shade is coming up. The labour is the most important item in the mordanting and dyeing method. The proportions of material used to the weight of the wool are: Of bichromate of potash, 3 per cent. for full shades, and 1 per cent. for pale shades; of fluoride of chrome, the same quantities; of acetate of chrome, according to the strength of the solution used; of alum, 10 to 20 per cent.; of sulphate of alumina, 5 to 10 per cent.; of copperas, 5 to 10 per cent.; of tartar, 1-1/2 to 2-1/2 per cent.; of oxalic acid, 1 to 1-1/2 per cent.; of sulphuric acid, 1 per cent.; of argol, 2-1/2 to 5 per cent.; of tartaric acid, 1 to 1-1/2 per cent.; but of course in an article like this it is impossible to give definite quantities. _Second Method_. #Stuffing and Saddening.#--This method consists in first treating the wool with a solution of the dye-stuff, and then with a solution of the mordant required to develop and fix the colour. This method is more particularly applicable to such dye-stuffs as camwood, cutch, logwood, madder, fustic, etc., the colouring principles of which have some affinity for the wool fibre and will directly combine with it. It is not suitable for the application of the Alizarine colours. The saddening may be and is commonly done in the same bath, that is, after the wool has been stuffed it is lifted, the mordant--copperas, bluestone, bichrome, or alum--is added, and the wool is re-entered into the bath. This cannot be considered a good method of working; the shades obtained are full and deep and fairly fast, but there is usually a considerable loss of colouring matter, as the wool in no case abstracts the whole of the dye-stuff from the bath; what excess is left combines with the mordant when the latter is added, forming an insoluble colour lake, which falls down to the bottom of the dye-vat and is wasted, or it may go upon the wool in (p. 075) a loose, unfixed form, and cause it to rub badly and come off in milling. Then it is rather difficult to dye to shade, much of the result depending on conditions over which the dyer has little control. Working as he does with dye-stuffs of unknown colouring power, which may vary from time to time with every fresh batch of material, it is evident that, although the same quantities may be used at all times, at one time a deeper shade may be obtained than at another, and as it is impossible to see what is going to be the result, and if by mischance the shade does not come deep enough it cannot well be rectified by adding a quantity of dye-wood to the bath, because the mordant in the latter will prevent the colouring matter from being properly extracted, and only a part of that which is extracted is fixed on the wool, the rest being thrown away in the dye-bath, and partly on the particles of wood themselves, when logwood, camwood, etc., are used in the form of chips or powder. Dyers being well aware of this, are in the habit when mistakes occur of bringing up to shade with soluble dye-stuffs--archil, indigo extract, and such like. This method, as stated above, is very wasteful, not only of dye-stuffs, but of mordants. In no case does the wool absorb the whole of the colouring matter from the bath, the unabsorbed portion goes down to the bottom of the bath when the mordant is added, so that when the dyeing is finished, the dye-bath is charged with a large quantity of colouring matter in an unusable form which has to be thrown away, thus at once adding to the pollution of the river into which it is run, and to the cost of the process of dyeing. As attention is being directed more and more to the question of the prevention of pollution of rivers, and as the waste liquors from dye-works add to the apparent pollution to a very considerable extent, dyers will have to develop other modes of dyeing than that of stuffing and saddening in one bath. The principle of dyeing by stuffing and saddening may be carried (p. 076) out by the use of two separate baths; in fact, it is done in the case of dyeing a cutch brown from cutch and bichromate of potash. The goods are first treated in a bath of the dye-wood for a short time, then rinsed, and the colour is developed by padding into a saddening bath of the mordant. By this method the baths, which are never quite exhausted, can be retained for future use, only requiring about 1/2 to 3/4 of the original quantities to be added for each succeeding batch of the goods, in fact, in some cases, as in cutch, old baths work better than new ones. The advantage attached to this method of working is that arising from economy of dye-stuff and mordant, and the reduction of the pollution of the stream on which the works are situated. The disadvantages are that the cost of labour is increased by there being two baths instead of one, and that the shades obtained are not always so full as with the one-bath method. This, of course, can be remedied by running the goods through the baths again, which, however, adds to the cost of the process, but there is this much to be said, the shade can be better brought up than by the one-bath process. In some cases the methods of mordanting, dyeing and saddening are combined together in the dyeing of wool, thus, for instance, a brown can be dyed by first mordanting with bichrome, then dyeing with camwood and saddening in the same bath with copperas. The shades obtained are fairly fast and will stand milling. The disadvantages of this process are the same as those attached to the dyeing and saddening in one bath. Now we come to the last method of dyeing wool with mordant and colours, that in which the operation is carried out in one bath. This can only be done in those cases where the colour lake that is formed is somewhat soluble in dye-liquors, which usually have slightly acid properties; or where the affinity between the two bodies (colouring matter and (p. 077) mordant) is too great. This method can be carried out in, for instance, dyeing a cochineal scarlet with tin crystals, a yellow from fustic and alum, a black from logwood and copperas and bluestone, a red from madder and bichrome, and the dyeing of the Alizarine colours by the use of chrome fluoride, etc. The shades obtained are usually not so deep as those got by the mordanting and dyeing process, but are frequently nearly so. In some cases, as in dyeing with fustic or logwood, it gives rather brighter colours, due to the fact that the tanning matters present in the dye-stuffs is not fixed on the wool, as is the case with the mordanting method, but is retained in the dye-bath. For dyeing with logwood and copperas or bluestone the process is not a good one, as it does not give as full shades as by the ordinary process. For dyeing with the Alizarine colours, using chrome fluoride as the mordant, it can be applied with fair success. There are advantages in the saving of time and labour and in the amount of steam required, all of which are important items in dyeing. It is rather troublesome to match off by this process, but it can be done. For light shades the process will be found very useful, as these cost less than by any other process. The dye-baths may be retained for future use, although in process of time they become too dirty for use, when they must be thrown away. #Level Dyeing.#--The first condition for successful dyeing is that the fibres to be treated are absolutely clean. A careful washing is not enough for this purpose. Cleanliness is undoubtedly the condition which the fibre must possess to enable the dye to hold on and not to come off the fibre, this latter causes a loss of dye-stuff, soils the whites, and gives rise to trouble between the dyer and finisher; it is also the condition for making the dye go on the wool evenly. The (p. 078) washing must be done at the boil, so that the fibre is well wetted out and all the air bubbles adhering to it are driven out. But this is not enough; it must be accompanied by a scouring operation, not only in the case of fibres of which the dyer does not know whether they have been scoured, but also when they have already been scoured and bleached. The kind of scouring that the fibres receive in this case need only be of a comparatively light character, but it must never be omitted, even for dark shades, as the traces of grease which the fibre contains are the causes of nearly irremediable stains in the dyeing operations. Even in dyeing black wool it is of the greatest importance to have the fibre suitably scoured. The fatty matters which the fibre contains may belong to the components of the fibre itself and be natural matters, but in the case of wool yarns and cloths they are mostly dressing oils, from which the dyer cannot be too anxious to free the wool before dyeing. Some practical methods of preparatory treatment of the fibres before dyeing may therefore be described here with advantage. Cotton is boiled off at actual boiling heat for two hours, with 8 per cent. of its weight of carbonate of soda and a little soft soap, which treatment is sufficient for dark colours. For light colours it is necessary that the cotton be bleached. Wool is scoured with soda and soap in the proportion of 10 lb. soda and 2 lb. Marseilles soap for 100 lb. wool. Silk is scoured by boiling for one and a half hours in a boiling bath with 30 per cent. of its weight of soap. For light colours a second boiling should be given, with 15 per cent. The careful cleaning of wool previous to dyeing is of exceptional importance. Raw wool is cleaned with carbonate of soda and ammonia. For 50 lb. wool to be cleaned 6 lb. carbonate of soda and 1-1/2 lb. (p. 079) ammonia are added to a bath of 150 gallons water. The wool is laid down in it for twenty minutes at 35° C., taken up, squeezed, treated for fifteen minutes in another bath, with 5 lb. carbonate of soda and then rinsed. The first bath must be renewed as often as possible, because it contains all the impurities. In the case of woollen yarn 30 lb. require two tubs of 40 gallons capacity. The first tub is to contain 35 gallons water and 2 lb. ammonia at 10° Be. After working the skeins for three minutes in it they are left to stand for fifteen minutes, then wrung out, and the operation is repeated in the second tub. Finally, the yarn is rinsed several times in soft water. Woollen piece goods are treated in a large wooden tub at 40° C. with 4 lb. carbonate of soda and 2 lb. carbonate of ammonia for 80 lb. material. The pieces are moved about for twenty minutes, laid down in the bath overnight, again turned for ten minutes and hydro-extracted. They may also be handled for forty minutes in a bath of 2 oz. ammonia for 100 lb. wool at 60° C., and then for twenty minutes in clear water at 60° C. After wetting or preparatory treatment, it will be best to proceed immediately to dyeing; if the fibres be left in a heap for too long a time, there is danger that they may become heated, or at least that the moisture may be irregularly distributed by the occurrence of partial drying, causing an uneven fixation of the colour in the first stages of dyeing. The first two conditions of successful dyeing are, therefore, a suitable wetting out and scouring. The dyer, however, must not be less careful to see that the dye-bath is what it ought to be. Whenever possible the dye-stuff must be dissolved separately, or at least the bath not entered before the dye-stuff is well dissolved. Artificial dye-stuffs require particular attention to this point, because the presence of undissolved particles is the cause of (p. 080) irregularities, such as streaks, or, at least, specks. The solution is mostly made hot as follows: After pouring water at 180° F. upon the dye-stuff, stir gently, strain through flannel or through a very fine sieve, and pour more water upon the residue until nothing more is dissolved. As is well known, the artificial dye-stuffs often contain insoluble matter, resins, etc. It is therefore advisable to use only soft water for this operation. The solutions of artificial dye-stuffs are ordinarily made at the rate of 1 to 5 lb. per 10 gallons of water, 2 lb. being the proportion mostly employed. This depends more or less on the solubility of the dye-stuff. Old solutions sometimes contain crystals of the dye-stuff which have separated out. These should be redissolved by heating before the solution is used. But it is best to make only such a quantity of solution as will suffice for immediate requirements. With paste colours care should be taken to keep them in closed vessels in such a manner that they will not become hard by evaporation, and they should not be kept in any place where they are likely to freeze in winter time. In such an event it is not an uncommon circumstance for the casks or other vessels containing them to burst, with a consequent loss of dye-stuff. Before any of the paste is withdrawn from the cask, it is advisable to stir well up with a wooden stirrer. In adding dye-stuff during the actual dyeing operation, it is advisable to add the dye-stuff to the bath in two or three portions, always taking out the goods before adding each lot of dye-stuff, and stirring up the contents of the bath before re-entering the goods. Another important condition of obtaining a level dyeing is to proceed slowly, beginning with a weak bath at a moderate temperature, and rising gradually to a boil. If necessary to retard the dyeing from the commencement, then an assistant mordant is added to the dye-bath, in the shape of soda crystals or phosphate of soda for the benzidine (p. 081) colours on cotton; bisulphate of soda or Glauber's salt in dyeing with azo colours or acid colours on wool; or tartar may be used in most cases with good effect, causing the wool to have a softer feel. Finally, the evenness of the dyeing is much increased by the frequent turning over of the material in the dye-bath, so managing this in the case of wool as to avoid felting. When dyeing with a mordant, the dyer should see that the mordanting operation is thoroughly well done, for as much care is required for the mordanting as for the actual dyeing; in fact, if anything, the mordanting should be done with rather more care, as if it be at all defective no amount of care in the following dyeing operations will ensure a level dyeing. Chrome mordanted wool should be dyed without delay, as it is rather sensitive to light, especially the yellow sort, which gradually changes into the green sort of chromed wool. One peculiarity of dyed wool is that it will continue to take up colour after it is removed from the dye-bath, especially if it contains any of the hot dye-liquor, therefore it is very desirable to wash the wool as soon as possible after its removal from the dye-bath. It is best, however, not to take the wool out of the hot bath, but to leave it in until the bath becomes cool, and then to take it out, by this means the colour becomes deeper and more solid looking, and is faster on the wool. One cause of irregular dyeing may be mentioned, as it is occasionally met with, namely, the presence of foreign fibres in the goods, cotton in wool fabrics, and even of different varieties of the same fibre. All dyers know that dead or immature cotton will not dye up properly, a fact or defect more especially met with in indigo dyeing than probably in any other colour. Then wools from different breeds of sheep vary considerably in their dyeing power. Fine wools take up more colour (p. 082) than coarse, and, consequently, even from the same bath, will come out a deeper shade; if a fabric, therefore, contains the two kinds of cotton, or the two kinds of wool, they will not dye up evenly. In the preceding sections brief notes have been given about the principal methods of dyeing wool, with some indications of the dyes which can be used under each method. In the succeeding sections will be given a number of recipes showing how, and with what dye-stuffs, various colours, shades and tints can be dyed upon wool. It will be understood that these recipes are applicable to all kinds of woollen fabrics, loose wool, slubbing, yarns in any form, woven worsted or woollen cloths, felts of any kind, etc., all these different forms require handling in a different way; it would not do, for instance, to treat a quantity of slubbing in the same way as a piece of worsted cloth, while hanks of yarn require a different mode of handling to a quantity of hat bodies. The different kinds of woollen fabrics require to be dealt with in different kinds of machines, and this has already been dealt with in the chapter on Dyeing Machinery and Dyeing Manipulations. To describe and illustrate the application of all the various woollen dye-stuffs, whether of natural or artificial origin, and to show the great variety of shades, etc., which can be obtained with them, either all one or in combination, would require not one, but many volumes of the size that this present work is intended to be. Therefore, it becomes necessary to make a selection from the best-known and most used of the various dyes, and illustrate their application by a number of recipes, all of which, unless otherwise stated, are intended to be for 100 lb. weight of woollen material of any kind. It may also be pointed out that, as a rule, the recipes may be applied to the dyeing of fabrics made with other animal fibres than the wool of the sheep, as, for alpaca, cashmere, camel-hair, hare or rabbit fur, etc., (p. 083) inasmuch, as, with the exception of silk, all animal fibres practically possess the same dyeing properties. It will be convenient to point out here that a very large proportion of the shades dyed on wool and other fabrics are obtained, not by the use of a single dye-stuff, although this should always be done, whenever possible, but by the combination of two or more dye-stuffs together in various proportions. It is truly astonishing what a great range of shades can thus be dyed by using two or three dyes suitably mixed together, and one of the things which go to making a successful dyer and colourist is the grasping of this fact by careful observation, and working accordingly. Dyers will find much assistance in acquiring a knowledge of colour and colour mixing from the two little books on _Colour_, by Mr. George H. Hurst, and the _Science of Colour Mixing_, by Mr. David Paterson, both issued by Messrs. Scott, Greenwood & Co., the publishers of the present work. #Black on Wool.#--Until within a comparatively recent time black was dyed on wool solely by the use of logwood, combined with a few other natural dye-stuffs, such as fustic, indigo, etc., but of late the researches of colour chemists have resulted in the production of a large number of black dyes obtained from various coal-tar products. These have come largely into use, but still, so far they have not been able to entirely displace logwood, chiefly on the score of greater cost, the use of the natural dye still remaining the cheapest way of producing a black on wool; although the blacks yielded by some of the coal-tar black dyes are superior to it in point of intensity of colour and fastness to scouring, acids and light, as well as being easier to dye. Blacks may be obtained from logwood by several methods, either by previous mordanting of the wool or by the stuffing and saddening methods, or by the one-bath process. The following recipes will (p. 084) show how these various methods are carried out in practice:-- _Chrome Logwood Black_.--The wool is first mordanted by boiling for one and a half hours with 3 lb. bichromate of potash and 1 lb. of sulphuric acid, working well the whole of the time. It is not advisable to exceed the amounts of either the bichromate or the acid here given, these quantities will result in a full bloomy black being obtained, but any excess gives rise to greyish dull blacks, which are undesirable. After mordanting rinse well with water, when the goods will be quite ready for the dye-bath. The dyeing is done in a bath made from a decoction of 40 lb. of good logwood. It is perhaps preferable to start cold or only lukewarm, raise to the boil and work for one hour, then lift, rinse well, and pass into a boiling bath made from 1 lb. of bichromate of potash and 1/4 lb. of sulphuric acid for half an hour. This extra chrome bath fixes any colouring matter which may have been absorbed by the wool but not properly fixed by the mordant already on, it leads to fuller shades which are faster to rubbing and milling. The mordanting bath may be kept standing and used again for fresh lots of wool, in which case it is only necessary to add 2-1/2 lb. of bichromate of potash and 1 lb. sulphuric acid to the bath for each additional lot of wool that is being dealt with. Old mordant baths work rather better than new ones, but the use cannot be prolonged indefinitely, there comes a time when the bath gets too dirty to use and then it must be thrown away. During the operation the bichromate of potash becomes more or less decomposed and there is formed on the wool fibre a deposit of chromic acid and chromic oxide, this deposit forms the mordant that in the subsequent dye-bath combines with and fixes the colouring matter, the hæmatoxylin of the logwood, and develops the black on the wool. In place of sulphuric acid, hydrochloric acid can be used with (p. 085) some advantage as regards the proportion of bichromate decomposed, and therefore an increase in the amount of chromium oxide deposited on the wool. This gives a deep blue black, somewhat wanting in bloom. The following recipe gives a much bloomier black, but is rather more expensive to dye. _Chrome Logwood Black_.--Mordant by boiling in a bath containing 3 lb. bichromate of potash and 7 lb. tartar. Dye and otherwise treat as in the last recipe; 4 lb. of tartaric acid used in place of the tartar, gives rather brighter and bloomier shades. The use of so-called tartar substitutes is not to be recommended, they give no better results than does sulphuric acid and are much dearer to use. A somewhat greener shade of black than is yielded by either of the above two recipes is the following:-- _Chrome Logwood Black_.--Mordant the wool in a bath containing 4 lb. oxalic acid and 3 lb. bichromate of potash, afterwards dyeing as in the first recipe. All the above recipes give blacks of a bluish tone, which on the whole have a good bloomy and solid appearance. Often what is called a jet black is wanted, this can be obtained by following the recipe given below. _Chrome Logwood Jet Black_.--Mordant the wool by any of the methods given above. The dyeing is done in a bath made from 40 lb. logwood and 5 lb. fustic, working as described in the first recipe. Using these properties a good jet black is obtained, which is quite satisfactory on the score of solidity and fastness. It is not advisable to exceed the quantity of fustic here given, or otherwise the black will have a tendency to assume a greenish tone that is not at all desirable. This greening becomes more marked when from 7-1/2 to 10 lb. of fustic is used, or if alum be added to the mordant along with the bichromate of potash. Chrome blacks are the best blacks which can be obtained from (p. 086) logwood. They have, however, a tendency to turn green on exposure to the weather, which tendency seems to be most prevalent in those blacks in which sulphuric acid has been used as the acid constituent of the mordanting bath. The greening may be reduced to a minimum by adding to the dye-bath about 1 to 2 lb. of Alizarine. Another plan which has been followed is to give the wool a bottom with 5 to 6 lb. of camwood or peachwood, then mordanting and dyeing us usual. _Logwood Black on Wool_.--Boil first for one hour with a decoction of 8 lb. camwood, then lay down for fifty minutes in a boiling bath of 3 lb. bichromate of potash, 1 lb. alum, 1 lb. tartar. It is a good plan to allow the goods to hang overnight. The dye-bath is prepared with 45 lb. logwood, 8 lb. fustic, 4 lb. sumac. Dye one hour at the boil, wash and dry. _Indigo Black_.--This is sometimes called woaded black, and has an excellent reputation as a fast black. It is dyed by first giving the wool a medium blue bottom in the indigo vat by the method of vat dyeing, which will be described later on, and then dyeing by either the second or third recipe given above. The use of sulphuric acid is rather to be avoided in dyeing an indigo vat with chrome and logwood, as the chromic acid set free during the process is likely to attack and by destroying the indigo to materially reduce the intensity of the blue bottom. Or, after blueing in the vat, the black may be dyed or topped on by the process with copperas, which will be described below. _Iron Logwood Black_.--Mordant the wool by boiling one and a half to two hours in a bath made with 5 lb. copperas, 2 lb. bluestone, 2 lb. alum, and 10 lb. argol. The dyeing is done in a bath of 50 lb. logwood. It is not advisable to use more argol than is here given, for (p. 087) although a little excess will not materially affect the beauty or brilliancy of the resulting shade, yet such excess is wasteful, and makes the dyeing cost more than it otherwise would. On the other hand, too little will cause the shade to become greyish in tone and wanting in solidity. The copper sulphate (bluestone) added increases the fastness of the finished black to light, the best proportions to add are from 2 lb. to 4 lb. for 100 lb. of wool. The shade obtained in the above recipe is of a bluish-violet hue, if a jet black be wanted, add 5 lb. of fustic to the dye-bath. Another and very common method of working is the "stuffing and saddening" process, given in the next recipe. _Iron Logwood Black_.--Make a bath of 50 lb. logwood, 6 lb. fustic, and 1 lb. sumac. Work the wool in this for one hour at the boil, lift, allow the bath to become cool, then add 6 lb. of copperas (ferrous sulphate) and 2 lb. bluestone; re-enter the wool, raise the temperature to the boil, and work half an hour, then lift, wash and dry. On the whole the first method is the most economical and yields the best blacks, fastest to rubbing. The iron-copper-logwood blacks are not so fast to acids as the chrome-logwood blacks, but they are rather faster to light and air, and equally so to scouring and milling. One-bath methods of dyeing blacks are sometimes preferred by wool dyers. Of these the following is an example. _Logwood Black_.--Make a dye-bath with 50 lb. logwood, 5 lb. fustic, 6 lb. copperas, 2 lb. copper sulphate, and 4 lb. oxalic acid. Enter the goods and work at the boil to shade. The oxalic acid is added for the purpose of retaining the logwood-iron-copper black lake, which is formed on mixing the various ingredients together in solution. On boiling the wool in the liquor the fibre gradually extracts out the dye matter and becomes dyed. The use of some of the so-called (p. 088) "direct blacks" (_noir reduit_, Bonsor's black) is based on the same principle. These dyes are mixtures of logwood, fustic or other dye-stuff with copperas, bluestone and oxalic acid, and only require adding to water to make the dye-bath. This method of working enables logwood to be used in conjunction with dihydroxynaphthalene and some other coal-tar derivatives to obtain blacks of good solidity and much faster to light, air, acids and scouring than the ordinary logwood blacks. Another recipe for a one-bath logwood black, using the extracts in place of the dye-wood itself, is the following:-- _Logwood Black_.--Prepare a dye-bath with 12 lb. logwood extract, 2 lb. fustic extract, 6 lb. copperas, 4 lb. bluestone, 3 lb. oxalic acid, 2 lb. tartar. Boil the goods in this for one hour. Some dyers use the dye-woods and prepare from them a decoction by boiling in water; in some respects this is the most economical plan, only the dyer has to get rid of the spent dye-wood from which the colouring matter has been extracted, and this is not always an easy matter. Some dyeing machines (Smithson's) have been devised which contain as one of their features a dye-wood extractor, in which the extraction of the colouring matter of the wood proceeds at the same time as the dyeing. Good results are got with such machines, although they leave something to be desired. Many dyers use the dye-wood extracts which are now made on a large scale. These are for the dyer much more convenient to use, although naturally rather more costly. They are approximately five times the strength of the dye-wood, but they vary very greatly in this respect. Logwood blacks can be readily distinguished from nearly all other blacks, in that by treatment with moderately strong hydrochloric acid they turn a bright red. No other natural dye-stuff is used in the dyeing of black than these here given. Of late years many black dyes derived from coal tar have been (p. 089) placed on the market. Among these may be enumerated the Acid Blacks of Messrs. Bead Holliday & Sons; the Naphthol and Naphthylamine Blacks of Leopold Cassella & Co.; the Victoria Blacks of the Farbenfabriken vorm, Fr. Bayer & Co.; the Wool Blacks of the Actiengesellschaft für Anilin Fabrikation; the Azo Blacks of the Farbwerke vorm, Meister, Lucius & Bruning; and one or two other blacks. These blacks are dyed very simply, as will be seen from the recipes given below, showing their application in the production of blacks of a great variety of tone. None of them dye a true jet black, but generally a bluish black or a violet black, but the tone may be readily changed to a jet or dead black by the addition of a little orange, yellow or green dye-stuff. They give blacks of a very solid appearance and very bright in tone, and have the advantage over the logwood blacks of leaving the wool more supple and less liable to be felted. Moreover, as a rule they are faster to acids, alkalies and milling than are the logwood blacks, and as regards fastness to light they excel that dye-stuff. Unfortunately they are more costly to use, which tells against their entirely displacing logwood in dyeing blacks on wool. Still, year by year their use is increasing, and as their price becomes less their employment will yet further extend. They may be combined with logwood, as they will dye with equal facility on mordanted and unmordanted wool. _Violet Black on Wool_.--Make the dye-bath with 4 lb. Acid Black B, or Acid Black B B, 3 lb. sulphuric acid, and 10 lb. Glauber's salt. Work at the boil for one hour. The B brand of these blacks gives shades slightly redder in tone than the B B. The blacks are quite fast to light and acids, but not to soaping. _Blue Black on Wool_.--Dye as in the last recipe, but use Acid (p. 090) Black S. This dye-stuff produces bluer shades of black than either B or B B, and they are faster to soaping. _Jet Black on Wool_.--Make the dye-bath with 4-1/2 lb. Acid Black S, 1/2 lb. Fast Yellow F Y, 3 lb. sulphuric acid, and 10 lb. Glauber's salt. This shows how, by the addition of a little yellow dye-stuff, the blue shade may be changed to a full jet black. _Blue Black on Wool_.--The dye-bath is made with 4-1/2 lb. Naphthol Black B (or 6 lb. Naphthol Black 3 B), 4 lb. sulphuric acid, and 10 lb. Glauber's salt. Work at the boil for one hour, then lift, wash and dry. The Naphthol Blacks have long been used in wool dyeing, and give excellent results, the 3 B brand dyeing much bluer shades than the B brand. There is also a 4 R brand giving violet blacks. These blacks are quite fast to acids and alkalies, are fast to light, and resist washing very well, the B brand being the fastest. The following recipe shows how a full jet shade can be obtained for these blacks:-- _Jet Black on Wool_.--Prepare the dye-bath with 4-1/2 lb, Naphthol Black B, 1 lb. Naphthol Green B, 1/4 lb. Indian Yellow, 4 lb. sulphuric acid, and 10 lb. Glauber's salt. _Blue Black on Wool_.--Make the dye-bath with 5 lb. Anthracite Black B, 10 lb. Glauber's salt, and 5 lb. bisulphate of soda, working at the boil for one hour. Anthracite Black does not require a bath so acid as do some other coal-tar blacks. The shade obtained is a full blue black, which is fast to acids; alkalies turn it a little bluer, and soaping causes some loss of colour. _Violet Black on Wool_.--Make the dye-bath with 5 lb. Anthracite Black R, and 10 lb. bisulphate of soda. The black thus obtained is a good one, fairly fast to acids, alkalies and soaping. _Dead Black on Wool_.--Make the dye-bath with 6 lb. Anthracite Black R, 1 lb. Anthracene Yellow C, and 10 lb. bisulphate of soda. Work at (p. 091) the boil for one hour, then lift, add 3 lb. fluoride of chrome and work again at the boil for twenty minutes. This black is a very fine one, and is very fast. _Violet Black on Wool_.--Make the dye-bath with 4 lb. Naphthylamine Black D, 10 lb. Glauber's salt, and 5 lb. acetic acid. This black is pretty fast to acids, alkalies and light, but is somewhat loose to soaping, and, therefore, cannot be used for black goods that have to be strongly milled. Naphthylamine Black 4 B dyes somewhat bluer shades than the B brand. _Blue Black on Wool_.--Prepare the dye-bath with 6 lb. Victoria Blue Black, 20 lb. Glauber's salt, and 1-1/2 lb. acetic acid, working at the boil for one hour. A fine blue black, is obtained which is quite fast to acids, washing and light. _Greenish Black on Wool_.--The dye-bath is made with 3 lb. Victoria Black Blue, 2 lb. Fast Yellow F Y, 20 lb. Glauber's, salt, and 1/1-2 lb. acetic acid. The dyeing is done at the boil and takes about an hour. This shade has a good full tone, and is fast. _Jet Black on Wool_.--Make the dye-bath with 4 lb. Victoria Black B, 1/2 lb. Fast Yellow F Y, 10 lb. Glauber's salt, and 2 lb. sulphuric acid, working at the boil for one hour. A very fine shade is thus obtained, which is fast to acids, alkalies and soaping. By omitting the Fast Yellow a blue black is obtained, while by using Acid Green instead a greener tone is given to the black. In place of the Victoria Black B the two other brands, 5 G, and G, of these blacks may be used. These give equally fast blacks of a deeper and more jet black. _Black on Wool_.--Prepare a bath with 5 lb. acetic acid, 9° Tw.; enter the wool for one hour, then lift and add 5lb. Naphthol Black 3 B, and 1/4 lb. Indian Yellow. Re-enter the goods and boil for one hour, wash and dry. Many of the black dyes--Naphthol Black, Naphthylamine Blacks, (p. 092) Naphthyl Blue Black N, Acid Black B, etc.--are capable of slowly dyeing wool from neutral baths, that is, containing only Glauber's salt, or rather more quickly if a little acetic acid be present. Such dyes are very useful for dyeing heavily milled or felted fabrics, such as hat bodies for instance, as then the dye possesses greater penetrative properties and passes more into the substance of the fabric, which is, therefore, better dyed through. Also they are suitable for dyeing half-wool fabrics as will be seen on referring to the chapter dealing with the dyeing of union or cotton-wool fabrics. It is quite possible to dye a black on wool by using a combination of acid and azo dye-stuffs, and below is given a recipe illustrating this method; it is one, however, rarely adopted. _Blue-Black on Wool_.--Prepare the dye-bath with 10 lb. Glauber's salt, 2 lb. Patent Blue, 6 oz. Brilliant Orange, 4 oz. Amaranth, 4 oz. Acid Violet N, 4 lb. sulphuric acid. Enter the goods at about 150° F., raise to the boil and work to shade; lift, wash and dry. It may be of interest to note that by using a mixture of Azo Rubine and Acid green good blacks can be got. There is a range of Acid and Azo dyes which are capable of dyeing from the usual acid baths on to wool, and yet can be developed and fixed on the fibre to good, full blacks. Types of such dyes are Anthracene Chrome Black F F, Diamond Black F, Chrome Patent Black D G and D G G, Fast Chrome Black, etc. Generally the blacks dyed on wool with these dyes are very fine, have a full, bloomy appearance, and are very fast. They are much used in dyeing hat bodies and fine cloths which have to be very fast to the weather. The method of application will be gleaned from the recipes given below. _Black_.--Prepare a dye-bath with 5 lb. Chromotrop S, 1/4 lb. Azo (p. 093) Yellow, 50 lb. Glauber's salt. Work for one and a half hours at the boil, then add 4 lb. sulphuric acid. Work at the boil for another half hour, then lift. Add to the same dye-bath 3 lb. bichromate of potash. Re-enter the goods and work at the boil for half an hour, then lift, rinse and dry. _Jet Black_.--Mordant the wool by boiling for one hour in a bath made from 4 lb. bichromate of potash and 3 lb. of tartar. Then rinse, and dye in a bath containing 3-1/2 lb. Diamond Black, 1-1/4 lb. Alizarine Cyanine R R R double, and 1 lb. Gambine Yellow, working at the boil for from one to one and a half hours. _Diamond Black on Wool_.--Mordant by boiling for one hour with 3 lb. bichromate of potash, 1 lb. oxalic acid. Wash and dry in a bath made with 2 lb. Diamond Black, 2 lb. acetic acid. Work at 120° F. for one hour, then heat to boil, and work until the dye is fully fixed. Lift, wash and dry. A more common method of using the Diamond Black is given in the following recipe. _Diamond Black_.--Prepare a dye-bath with 10 lb. Glauber's salt, 2-1/2 lb. Diamond Black, 1/2 lb. Diamond Green. Boil for an hour, then pass through a fresh bath of 2 lb. bichromate of potash for three-quarters of an hour at the boil; wash and dry. This gives a fine jet shade of black, quite fast to a strong milling, and to light, alkalies and acids. Diamond Black by itself gives bluish shades. This dye is much used in the hat-dyeing trade. _Violet Black_.--Mordant the wool by boiling for one and a half hours in a bath made with 3 lb. fluoride of chrome and 1 lb. oxalic acid, then rinse and dye in a bath containing 25 lb. Alizarine Cyanine Black G, 5 lb. acetate of ammonia, and 1 lb. acetic acid, working at the boil for one and a half hours. A fine full shade is obtained (p. 094) which is quite fast to acids, milling and light. _Brown Black_.--Mordant the wool as in the last recipe, then dye in a new bath 25 lb. Alizarine Cyanine Black G, 3 lb. Anthracene Brown, 5 lb. acetate of ammonia, and 1 lb. acetic acid, working at the boil for one to one and a half hours. _Jet Black_.--Mordant as in either of the above recipes, then dye in a bath containing 20 lb. Alizarine Black S W, and 2 lb. acetic acid. This black possesses a great degree of resistance to acid, alkali, milling and light, and is one of the best blacks at the disposal of the dyer. _Reddish Black on Wool_.--Prepare the dye-bath containing 5 lb. Chromotrop 2 B, 10 lb. Glauber's salt, and 4 lb. sulphuric acid, work at the boil for one hour, then lift. Add to the same bath 3 lb. bichromate of potash and 1 lb. sulphuric acid, and work half an hour longer. _Blue Black_.--Make the dye-bath with 6 lb. Chromotrop 10 B and 4 lb. sulphuric acid; dye, and develop the black by adding to the same bath 3 lb. bichromate of potash and 1 lb. sulphuric acid. _Jet Black_.--Prepare the dye-bath with 5-1/2 lb. Chromotrop S, 1/4 lb. Alizarine Yellow G G W, 10 lb. Glauber's salt, and 4 lb. sulphuric acid. Slowly raise to the boil and work for one hour, then add to the same dye-bath 3 lb. bichromate of potash, and 1 lb. sulphuric acid, working at the boil for one hour. These are but a few examples of how the Chromotrops (one of the most interesting series of dye-stuffs at the service of the dyer) may be used to dye blacks. They of themselves dye brilliant reds, from bright scarlet (2 R), crimson (6 B), and purple (8 B and 10 B), to maroon and clarets (S and S B). These being turned black on being chromed, give various shades--blue blacks, violet blacks, and jet blacks, which have the merit of being fast to acids, strong milling, and light in a great degree. The blue and violet blacks may be converted to jet (p. 095) shades by adding to the dye-bath some yellow dye-stuff, such as Azo Yellow, Alizarine Yellow, or Gambine Yellow, which will resist the action of the bichrome in the developing bath. Chromotrop blacks while so very fast have the disadvantage of being expensive, but by combining them with logwood it is possible to obtain blacks that have a great degree of resistance to light, acids and milling. They are in this respect much superior to pure logwood blacks, while the cost is not prohibitive. The following recipe will serve as an example of how these two dye-stuffs may be combined:-- _Jet Black_.--Make a bath with 2 lb. Chromotrop S, 15 lb. Glauber's salt, and 5 lb. hydrochloric acid. Work in this bath for one hour, then add 2-1/2 lb. bichromate of potash, and work again for half an hour, at the boil. Lift, rinse and dye in a new bath containing 25 lb. logwood, 1 lb. fustic extract and 1/4 lb. sulphuric acid, working at the boil for an hour. _Violet Black on Wool_.--Dye the wool in the Chromotrop bath, and develop as in the last recipe. The final dye-bath is made with 6 lb. logwood, 8 oz. Patent Blue B, and 4 lb. sulphuric acid. By using logwood alone blue blacks can be dyed, by increasing the proportion of fustic a greener tone can be obtained, while by the use of a larger proportion of Chromotrop a redder tone of black is the result. _Jet Black_.--Make the dye-bath with 20 lb. Glauber's salt, and 6 lb. Nyanza Black; when obtained is a good one and of solid appearance. Alkalies turn it red, but it is fast to dilute acid and soaping. _Black_.--Prepare the dye-bath with 10 lb. Glauber's salt, 5 lb. oxalate of ammonia, 5 lb. acetic acid and 6 lb. Anthracene Chrome Black F. Work at the boil for three-quarters of an hour, or until (p. 096) the bath is exhausted of dye-stuff, then add 1-1/2 lb. bichromate of potash and 2 lb. hydrochloric acid to the same bath and work for half an hour longer. The Anthracene Chrome Blacks, of which there are three brands, F, 5 B and F E, are excellent dyes, producing very fine blacks, and owing to the slowness of dyeing and great penetrative properties are very suitable for dyeing hat felts and other closely woven fabrics. The 5 B dyes more bluish shades than the F, while the F E brand gives full black. By combining these with Anthracene Yellow B N, Anthracene Acid Brown G, or other similar dyes, jet blacks can be got as per the following recipe:-- _Jet Black_.--Make the dye-bath with 6 lb. Anthracene Chrome Black F E, 5 oz. Anthracene Yellow B N, 10 lb. Glauber's salt, 2 lb. oxalate of ammonia and 5 lb. acetic acid, after dyeing, and the dye-bath, is exhausted of colour, add 1-1/2 lb. bichromate of potash and 3 lb. hydrochloric acid, and boil again for half an hour. Finish in the usual way. One of the reasons for adding the oxalate of ammonia, is to precipitate out any lime which may be in the water in such a form that it will not react with the dye-stuff. _Fast Black_.--Mordant the yarn with copperas (sulphate of iron). Dye in a bath with 5 lb. Gambine Y, 2 lb. Acid Mauve, 2 lb. bisulphate of soda. Proceed as described for full green. _Blue Black_.--3-1/2 lb. Naphthylamine Black S, 10 lb. Glauber's salt, and 5 lb. acetic acid; to fully exhaust the dye-bath add 8 lb. bisulphate of soda. _Jet Black_.--5 lb. Naphthylamine Black S, 1/4 lb. Fast Acid Green B N, 10 lb. Glauber's salt, and 5 lb. acetic acid, adding 8 lb. bisulphate of soda to exhaust the bath. _Blue Black_.--Give a deep blue bottom in the indigo vat and dye with 2 lb. Anthracite Black B, 10 lb. Glauber's salt and 2 lb. acetic acid. #Greys on Wool.#--The dyeing of greys follows very naturally after (p. 097) the dyeing of blacks, for from a broad point of view greys are simply light blacks, and any dye-stuffs that will dye black will if used in smaller proportions give greys. There is a great variety of tone among greys: reddish greys, bluish greys, greenish greys, and so on. They may be dyed in a considerable variety of ways from a large number of dye-stuffs, both natural and artificial. Of these two classes the latter gives the best result as far as regards brightness of tone, and as regards other properties the greys obtained from the artificial coal-tar colours are fully equal to those from natural dyes. A large number of recipes are in use by dyers for the production of greys, so many that it becomes almost an impossibility to do more than give a mere fraction of them here. However, a number of representative recipes will be given, covering all classes of dye-stuffs capable of being used for the purpose, and thus forming a guide to the methods of dyeing and the proportions of dye-stuffs to be used. _Light Grey_.--Dye at the boil for three-quarters of an hour, in a bath containing 1 lb. perchloride of tin, 3 lb. alum, 3 oz. indigo extract, and 2 oz. cochineal. _Slate Grey_.--Mordant by boiling with 4 lb. alum and 1 lb. argol, then dye with 6 lb. logwood, 6 oz. cudbear and 3 oz. indigo extract. _Slate Grey_.--Another method is to boil the wool with 10 lb. logwood, 2 lb. Glauber's salt and 1 lb. sulphuric acid for three-quarters of an hour, then lift, add 1 lb. copperas, and re-enter the wool, working at the boil for three-quarters of an hour, then lift, wash and dry. _Reddish Grey_.--Boil for an hour with 10 lb. fustic, 11 lb. cutch, 1/2 lb. bichromate of potash and 1-1/2 lb. copperas. _Pearl Grey_.--Give a light blue ground in the indigo vat, then dye in a new bath with 2 lb. muriate of tin and 3/4 lb. cochineal, working at the boil to shade. _Silver Grey_.--Prepare a bath with 3/4 lb. tannic acid; work for (p. 098) an hour in a warm bath, then sadden with 3 lb. nitrate of iron to shade, then lift, wash and dry. _Pearl Grey_.--Prepare a bath with 3 lb. fluoride of chrome and 4 lb. Alizarine Bordeaux B. Enter into the bath when cold, then heat to the boil and work for one and a half hours, then lift, wash and dry. _Silver Grey_.--The dye-bath is made with 3 lb. fluoride of chrome and 6-1/2 oz. Alizarine Cyanine G G, the dyeing being done as in the last recipe. _Greenish Grey_.--A good shade is dyed with 3 lb. fluoride of chrome, 4 oz. Alizarine Bordeaux B, and 4 oz. Diamond Flavine G, working as given in the above recipe. _Grey_.--Give a pale blue bottom with an indigo vat, then dye in a bath containing 1 lb. fluoride of chrome, 1/2 oz. Diamine Fast Red F, and 3/4 oz. Anthracene Yellow C; work at the boil for one hour, lift, wash, and dry. _Dark Grey_.--A very fine dark grey, almost approaching a black is obtained by the following plan: bottom the wool with a medium blue by means of the indigo vat, dye in a bath containing 1 lb. fluoride of chrome, 3 oz. Diamine Fast Red F, and 3 oz. Anthracene Yellow C. _Slate Grey_.--A good slate grey of a slightly greenish tone can be dyed in a bath of 5 lb. acetate of ammonia, 3/4 lb. Acid Blue 4 S, and 1/4 lb. Titan Brown R, working at the boil to shade. _Pale Slate Grey_.--The dyeing is done in a bath made with 5 lb. acetate of ammonia, 5 oz. Acid Blue 4 S, and 1-1/2 oz. Titan Brown R, working at the boil for one hour. _Silver Grey_.--A very nice shade is dyed with 3 oz. Acid Blue 4 S, 1/4 oz. Titan Red, and 5 oz. acetate of ammonia. _Silver Grey_.--A shade similar to the last is dyed in a bath containing 10 lb. Glauber's salt, 5 lb. bisulphate of soda, and 3/4 oz. Anthracite Black R. By adding a little Thiocarmine R the (p. 099) shade can be turned bluer in tone, while the addition of a little Milling Yellow O, or Titan Yellow, turns it to the green side. _Pearl Grey_.--Make the dye-bath with 10 lb. Glauber's salt, 5 lb. acetic acid, and 3/4 lb. Naphthylamine Black D. This gives fine shades of pearl grey. _Bluish Grey_.--Mordant the wool by boiling in a bath made with 2 lb. bichromate of potash, 1 lb. tartar, and 1 lb. sulphuric acid. Dye in a bath containing 2 oz. Diamine Black (or 3/4 oz. Diamond Black and 1-1/2 oz. Alizarine Cyanine R), working at the boil for an hour and a half. _Grey_.--This can be dyed with 3 oz. Nyanza Black B, and 10 lb. Glauber's salt, working at the boil. _Reddish Grey_.--A good full shade is dyed with 1-1/2 oz. Cyanole extra, 1/4 oz. Orange extra, 3/4 oz. Archil Substitute N, 10 lb. Glauber's salt and 3 lb. sulphuric acid. _Slate Grey_.--The dye-bath is made with 3 oz. Cyanole extra, 1/2 oz. Archil Substitute N, 3/4 oz. Orange extra, 10 lb. Glauber's salt and 2 lb. sulphuric acid. _Bright Pearl Grey_.--Prepare a dye-bath with 3/4 oz. Patent Blue, 1/2 oz. Acid Violet N, 3/4 oz. Orange G, 10 lb. Glauber's salt and 2 lb. sulphuric acid. _Stone Grey on Wool_.--The dye-bath is made with 1/2 oz. Chromotrop 2 R, 3/4 oz. Cyanole extra, 1-1/2 oz. Fast Acid Blue R, 3/4 oz. Acid Yellow, 20 lb. Glauber's salt, 3 lb. acetic acid. Enter at 80° F., then warm slowly and work to shade, lift, wash and dry. These recipes will probably be sufficient to show the lines on which greys may be obtained in wool dyeing. It may be added that from the Acid Blacks B, B B, and S, good greys of a violet tone may be obtained, using from 1/2 to 3/4 oz. dye-stuff. The Naphthol Blacks will also be found useful in the same way, while the greys from Anthracene Chrome Blacks and the Alizarine blacks are very good and fast. #Red Shades on Wool.#--The number of red shades that may be dyed (p. 100) on wool is infinite. They range over every variety of tint of red, from the palest blush-rose to the deepest crimson, and from the most brilliant pink to the dullest grenat shade. It is quite impossible here to describe the dyeing of every imaginable shade of red, while the great variety of red dye-stuffs, both natural and artificial, adds to the difficulty of dealing in the space at command with all the various methods and dyes that may be used in the dyeing of reds on wool. The methods that may be adopted for dyeing red shades on wool are many and various, depending not only on the particular dye-stuff used, but often on the particular shade that is being dyed. One method, which will yield a pale and useful tint with a particular dye-stuff, would fail if a full shade were necessary. The greater number of red shades are now dyed by means of the artificial dye-stuffs, as these are much easier to dye than are the natural dyes, and they give, on the whole, more even and brilliant shades, while as regards fastness to milling, acids, and light they are fully equal, and in most cases superior, to the natural dyes. #The Direct Red Dyes.#--Of this group of red dye-stuffs, Benzopurpurine, Titan Scarlet, Diamine Fast Red F, and Benzo Fast Red are types; many of them have been found to be very serviceable in wool dyeing. They may be dyed either from plain baths containing common salt or Glauber's salt, or from baths containing common salt or Glauber's salt and a little acetic acid. Alkaline or soap baths do not work well as a rule, and must be avoided in wool dyeing. Generally the dye-bath is exhausted of colour, and full shades are easily obtained, while these reds are in general remarkable for the evenness and uniformity of tint which can be (p. 101) produced. The reds so dyed are, on the whole, fairly fast to soaping, and can be used for dyeing goods that have to be milled, while their resistance to light and air is fairly good. Benzopurpurine and Diamine Red are more or less affected by acids, but the Titan Red and some of the more modern reds, Diamine Brilliant Scarlet, Benzo Fast Scarlets, are all fast to acids. The fastness to washing and light of some of them, Benzo Fast Red, Diamine Fast Red F, Titan Red, is much increased by adding, after the wool has been dyed, 3 per cent. of fluoride of chromium to the dye-bath, and working a little longer. The dyeing with these colours is done at the boil, and the goods may be entered direct into the boiling bath without fear of uneven shades being produced. This bath may be kept as a standing one, simply adding as each lot is dyed the necessary quantity of dye-stuff, a little fresh water to bring the bath up to its original volume, and a corresponding quantity of the salt originally added. The wool can then be entered and dyed. In place of using salt or Glauber's salt, acetate of ammonia is an excellent assistant for this class of dyes. The following are some recipes for dyeing various shades of red on wool with this class of dyes. _Scarlet_.--The dye-bath is made with 3 lb. Titan Scarlet C B, and 10 lb. acetate of ammonia. This gives a good bright shade of scarlet, which is fast to acids and soaping, although not fast to light. _Scarlet_.--Dye in a bath made with 3 lb. Diamine Scarlet B and 10 lb. Glauber's salt. This yields a light shade, not so fast to acids as the last, but equally fast to soaping and light. _Scarlet_.--Make the dye-bath with 3 lb. Benzopurpurine 4 B, and 10 lb. Glauber's salt. This also gives a good shade of Scarlet fast to soaping. It is turned dark blue by acids, and is not fast to (p. 102) light. It is very largely used on underwear goods, but is not so satisfactory for this as the Titan Scarlet C B, or Benzo Fast Scarlet B S. _Scarlet_.--The dye-bath may be made with 3 lb. Brilliant Congo G, 10 lb. Glauber's salt and 2 lb. acetate of ammonia. This gives a satisfactory shade of scarlet. _Bright Scarlet_.--The dye-bath prepared with 2 lb. Geranine G, 5 lb. sulphate of soda, 5 lb. acetate of ammonia. Work at the boil for one hour, then wash and dry. _Dark Crimson_.--Prepare a dye-bath with 1-1/2 lb. Chrysophenine, 1-1/2 lb. Hessian Violet, 25 lb. salt. Heat to 150° F., enter the goods, heat to boil and dye boiling for one hour, take out, rinse and wash. _Scarlet_.--A brilliant shade of scarlet can be dyed in a bath of 3 lb. Benzo Fast Red, 1 lb. Chrysophenine, 10 lb. Glauber's salt and 2 lb. acetic acid. _Fast Red_.--Dye the wool in a bath boiling, containing 1 lb. Diamine Fast Red F, 10 lb. Glauber's salt, and 2 lb. acetic acid, until the bath is exhausted, then add 3 lb. fluoride of Chrome and work half an hour longer at the boil. _Bordeaux_.--Dye with 3 lb. Diamine Bordeaux, and 10 lb. Glauber's salt. _Pink_.--Dye with 2 lb. Diamine Rose B D, 10 lb. Glauber's salt and 1 lb. acetic acid. The basic red dyes are not very numerous, and comprise Magenta, Saffranine, Acridine Reds, Acridine Scarlets, Rhoduline Reds, Rhodamine and Neutral Beds. For successful dyeing they require a perfectly neutral bath. This bath should contain 10 per cent. of Glauber's salt, and is started cold and not too strong; when all the material has been entered the steam may be turned on and the temperature slowly raised, the material being turned over and over. The operation is continued only until the bath has been exhausted of colour, when it is stopped, and the wool taken out, and washed (p. 103) and dried. The liquor in the dye-baths may be allowed to cool down, and then it may be used for making the dye-bath for a second lot of goods, or it may be run away. It is best not to add the dye to the bath all at once, but in several portions as the work proceeds. The affinity of the wool for the basic dyes is usually so strong that if all were added to the dye-bath at the start, then the first portion of the goods entered might take up all, or nearly all, the colour, leaving but little for the last portion; the consequence being that the goods are dyed of an uneven colour, deeper in some parts than others. This defect is remedied by adding the dye in portions, entering the goods rather quickly, working cold, or by adding a little acetic acid and plenty of Glauber's salt. Notwithstanding all these precautions it is quite possible for the shades to come up somewhat uneven. These remarks are applicable not only to the basic reds but to the whole range of basic dyes, hence this class of dye-stuffs is but little used in the dyeing of wool. _Crimson_.--Make the dye-bath with 2 lb. Magenta, and 15 lb. Glauber's salt, working as described above. This gives a fine crimson shade which, however, is not fast to soaping or to light. The quantity of dye-stuff given above should not be exceeded or the shades may come up bronzy, this may be avoided if a trace of acetic acid is added to the dye-bath. _Crimson_.--Dye with 2-1/2 lb. of Saffranine and 15 lb. Glauber's salt. This dyes a fine Crimson shade. _Deep Red_.--Use 3 lb. Rhoduline Red and 10 lb. Glauber's salt. _Scarlet_.--The dye-bath is made with 1 lb. Saffranine Prima, 1 lb. Auramine, and 10 lb. Glauber's salt. The goods are entered into the dye-bath at about 120° F., and well worked about, then the temperature is raised slowly. When the dye-bath is exhausted the goods are lifted, washed and dried. There are no pure basic scarlets, and the above and similar combinations of a basic red and a basic yellow are the (p. 104) only ways in which a scarlet can be dyed on wool with basic coal-tar colours. The basic colours are, in general, the hydrochlorides of some colour base, and in the process of dyeing the acid constituent of the wool fibre unites with the colour base, while the hydrochloric acid which is liberated passes into the dye-bath. The acid reds are a very large group of red dyes, of somewhat varied chemical composition, which all have the property of dyeing from baths containing Glauber's salt and sulphuric acid or acetic acid, the usual proportions being 10 per cent. of the former, and 2 to 5 per cent. of the acid. Some are best dyed from a bath containing bisulphate of soda. The dyeing should be started cold, or at a lukewarm heat, then steam should be turned on and the temperature raised to the boil, at which it is maintained for an hour; this boiling serving to more intimately fix the dye-stuff on the woollen fibre. The Eosine reds, of which Eosine in its various brands, Rose Bengale, Phloxine, Saffrosine and Erythrosine, are examples, are best dyed upon wool from a bath containing Glauber's salt and a little acetic acid. They do not require a very acid bath, hence the reason of using acetic acid. The method of dyeing is that given above as for basic reds, namely, enter into cold, or at most lukewarm bath, and raise the heat slowly, continuing the work until the shade required has been obtained. It is a good plan to start work in a neutral bath, and then when the material has become thoroughly impregnated with the dye-liquor to add the acetic acid. The shades obtained from these Eosine reds are remarkable for their brilliance, but unfortunately their fastness to light, washing, etc., is but slight, although it may be increased by treating the dyed wool in a bath of alum or acetate of lead. Some of the acid reds, _e.g._, Acid Magenta, Acid Violet, belong (p. 105) to the group of sulphonated basic dyes. The vast majority belong to the group of azo dyes, which can be employed to dye from palest pinks to the deepest crimson reds. Some dye very brilliant shades, others only yield dull reds. Some dye shades remarkable for their fastness to all agencies, soap, acids, alkalies, light and air; others dye shades which may be fast to soap, but loose to acids and light. Generally even shades are readily obtained on any kind of woollen fabric. It is practically impossible to name all the acid reds that are known and that may be used, but a fairly representative series of recipes will be given. _Ponceau_.--Wet out, then prepare a bath with 2 lb. Ponceau R, 10 lb. Glauber's salt, 2 lb. sulphuric acid. Enter the wool in the cold, bring to a boil and work to shade, wash and dry. _Crushed Strawberry_.--Prepare a bath containing 10 lb. Glauber's salt, 4 oz. Scarlet R S, 9 oz. Indigo extract, 2 oz. Orange Y, 4 oz. sulphuric acid. Enter wool at 160° F., give four turns, raise temperature slowly to a boil, and turn to shade, lift and wash. _Scarlet_.--Prepare a dye-bath with 2 lb. Azo cochineal, 10 lb. Glauber's salt, 4 lb. sulphuric acid. Work at the boil until the full shade is obtained, then lift, wash and dry. _Terra Cotta Red_.--The dye-bath is made from 2-1/2 lb. Fast Acid Magenta B, 2-1/2 lb. Fast Yellow F Y, 10 lb. Glauber's salt, 2 lb. sulphuric acid. Work at the boil to shade. _Fast Scarlet_.--Prepare a dye-bath with 3 lb. Glauber's salt, 1-1/4 lb. sulphuric acid, 2-1/2 lb. Brilliant Scarlet 4 R. Work at the boil for one and a half hours. _Scarlet_.--Make the dye-bath with 2 lb. Scarlet 2 R J, 10 lb. Glauber's salt and 2 lb. sulphuric acid. The goods may be entered at about 150° F., and the temperature raised at the boil and maintained at that heat for one hour, then the goods are lifted, rinsed and dried. The method given in the above recipes is that usually followed (p. 106) with the acid colours. When closely woven or thick goods are being dyed, where it is desired that the colour should penetrate well into the substance of the goods, the following modification of working may be adopted:-- The dye-bath is made up with the dye-stuff and Glauber's salt only, and the goods are worked in this at the boil until they are thoroughly impregnated with the dye-stuff liquor, then the acid is added in small quantities at a time, and the dyeing is continued for one hour to fix the colouring matter on the wool fibre. The goods may then be lifted out, washed and dried. _Scarlet_.--Make the dye-bath with 2 lb. Scarlet F R, 10 lb. Glauber's salt and 2 lb. sulphuric acid. In place of scarlet F R, the F 2 R or F 3 R brands may be used, the latter giving the reddest shades. _Scarlet_.--Make the dye-bath with 2 lb. Scarlet O O, 10 lb. Glauber's salt and 2 lb. sulphuric acid. Scarlet O dyes a yellower shade of scarlet, while scarlets O O and O O O dye slightly redder shades. _Scarlet_.--The dye-bath is made with 3 lb. Brilliant Ponceau 2 R, 10 lb. Glauber's salt and 10 lb. bisulphate of soda. This gives a brilliant shade of scarlet. Brilliant Ponceau G, used in the same way, gives a much yellower tone of scarlet, the R gives a slightly yellower tone, while the 3 and 4 R brands dye redder shades. _Bluish Red_.--The dye-bath is made with 2 lb. Brilliant Croceine B, 10 lb. Glauber's salt, and 10 lb. bisulphate of soda. Brilliant croceine B B and the brand M dye redder shades of scarlet. _Red_.--Make the dye-bath with 3 lb. Milling Red R, 20 lb. Glauber's salt, and 5 lb. acetic acid. This is a good bright shade, and is quite fast to soaping and milling. _Deep Scarlet_.--Dye with 3 lb. Chromotrop R, 10 lb. Glauber's (p. 107) salt, and 2 lb. sulphuric acid. This scarlet is very fast to milling, acid and light. _Red_.--Make the dye-bath with 2 lb. Victoria Scarlet R, 1 lb. Victoria Rubine O, 10 lb. Glauber's salt, and 4 lb. sulphuric acid. A fine deep scarlet red is obtained. _Scarlet_.--Dye with 2 lb. Brilliant Orseille C, 10 lb. Glauber's salt, and 3 lb. sulphuric acid. This gives a bright bluish shade of scarlet. _Red_.--Dye with 1 lb. Emin Red and 5 lb. bisulphate of soda. _Scarlet_.--Make the dye-bath with 3 lb. Croceine Scarlet 3 R, 10 lb. Glauber's salt, and 2 lb. sulphuric acid. _Fawn Red_.--Make the dye-bath with 1-1/2 oz. Cyanole, 1-1/2 oz. Orange extra, 2-1/2 oz. Archil Substitute N, 10 lb. Glauber's salt, and 2 lb. sulphuric acid. This gives a nice light tint of fawn red, of a somewhat bluish tone. _Deep Fawn Red_.--A very deep shade of fawn red is dyed with 4-1/2 oz. Cyanole, 2-1/4 lb. Orange extra, 1-1/4 lb. Archil Substitute N, 10 lb. Glauber's salt, and 2 lb. sulphuric acid. The same dye-stuffs are used as in the last, but the result is a deeper shade, of a yellow tone. _Crushed Strawberry Red_.--Use 4 oz. Chromotrop 2 R, 2 oz. Cyanine B, 1 oz. Azo yellow, 10 lb. Glauber's salt, and 2 lb. sulphuric acid. _Pale Lilac Rose_.--Dye with 1 oz. Chromotrop 2 R, 1/2 oz. Cyanine B, 1/2 oz. Azo yellow, 10 lb. Glauber's salt, and 2 lb. sulphuric acid. _Deep Fawn_.--Dye with 3-1/4 oz. Chromotrop 2 R, 1-1/2 oz. Orange G, 2 oz. Cyanine B, 4 oz. Fast Acid Blue R, 10 lb. acetic acid, and 20 lb. Glauber's salt. _Crimson_.--Make the dye-bath with 3 lb. Titan Red 6 B, 20 lb. salt, with a little acetic acid, and work at the boil. This gives a fine shade of crimson, fast to acids and capable of standing milling very well. _Deep Crimson_.--A bright and deep crimson is dyed with 4 lb. Fast (p. 108) Acid Magenta B, 10 lb. Glauber's salt, and 3 lb. sulphuric acid, working at the boil. _Pale Crimson_.--Make the dye-bath with 2 lb. Fast Acid Magenta B, 10 lb. Glauber's salt, and 2 lb. sulphuric acid, working at the boil. Level shades are readily obtained, and the dye is fast to washing. _Deep Crimson_.--Make the dye-bath with 4 lb. Azo Fuchsine G, 10 lb. Glauber's salt, and 2 lb. sulphuric acid. This gives a very deep shade of crimson, of a bluish tone. _Bluish Crimson_.--Use in the dye-bath 2 lb. Azo Fuchsine G, 10 lb. Glauber's salt, and 2 lb. sulphuric acid. _Pale Bluish Crimson_.--Use in the dye-bath 1 lb. Azo Fuchsine G, 10 lb. Glauber's salt, and 2 lb. sulphuric acid. This gives a very bright shade of pale crimson. The B brand of the Azo Fuchsines gives slightly bluer shades than the above. _Deep Crimson_.--A very solid crimson is dyed in a bath containing 3 lb. Azo Red A, 2 oz. Orange extra, 2 oz. Cyanole extra, 10 lb. Glauber's salt, and 2 lb. sulphuric acid. Work at the boil. _Bright Crimson_.--A fine bluish crimson can be dyed on wool with 4 lb. Azo Red A, 10 lb. Glauber's salt, and 10 lb. bisulphate of soda. Work at the boil. _Deep Crimson_.--A good shade can be dyed with 6 lb. Amaranth, 10 lb. Glauber's salt, and 10 lb. bisulphate of soda, working at the boil. _Brilliant Pale Bluish Crimson_.--A really brilliant shade, bordering on a violet red, is dyed in a bath containing 1-1/2 lb. Fast Acid Violet R, 10 lb. Glauber's salt, and 2 lb. sulphuric acid. _Bluish Crimson_.--Make the dye-bath with 3 lb. Croceine Scarlet, 10 lb. Glauber's salt, and 2 lb. sulphuric acid. This gives a good full shade of a bluish tone and very bright. _Bluish Crimson_.--Dye with 3 lb. Chromotrop 6 B, 10 lb. Glauber's salt, and 3 lb. sulphuric acid. This gives a fine tint, (p. 109) very fast to acids, milling and light. _Purple_.--Make the dye-bath with 3 lb. Chromotrop 10 B, 10 lb. Glauber's salt, and 3 lb. sulphuric acid. The Chromotrops are remarkable for the fulness of the shades they dye, the brightness of their tint, and their fastness to acids, washing and light. _Purple_.--Use 4 lb. Azo Fuchsine B, 10 lb. Glauber's salt, and 2 lb. sulphuric acid. _Bluish Purple_.--A very dark shade of purple is dyed with 4 lb. Azo Acid Violet 4 R, 10 lb. Glauber's salt, and 2 lb. sulphuric acid. #Bordeaux Reds#.--These are shades that lie intermediately between the scarlets and the crimsons. They are in general duller than the scarlets, and have a more solid and fuller look; while they are less blue in tone than the crimson. They can be obtained from a large variety of dye-stuffs, and the recipes given below may be regarded as typical examples. _Bright Bordeaux Red_.--Make the dye-bath with 1 lb. Azo Bordeaux, 10 lb. Glauber's salt, and 2 lb. sulphuric acid, working at the boil to shade. This is a very bright shade, of a somewhat bluish tone. _Cherry Red_.--Make the dye-bath with 2-1/2 lb. Fast Acid Magenta B, 2-1/2 lb. Fast Yellow, 10 lb. Glauber's salt, and 2 lb. sulphuric acid. This gives a fine deep shade. _Bright Cherry Red_.--A very yellow shade of red, fast to milling, is dyed by making a dye-bath with 1-1/2 lb. Anthracene Yellow C, 3 lb. Diamine Fast Red F, 10 lb. Glauber's salt, 5 lb. acetate of soda, and 2 lb. bisulphate of soda. Work at the boil for one hour, then lift, add 3 lb. fluoride of chrome, re-enter the wool and work half an hour longer; wash and dry. _Deep Bordeaux Red_.--The dye-bath is made with 4 lb. Diamine Fast Red F, 5 lb. acetate of soda, and 3 lb. bisulphate of soda. Work (p. 110) at the boil for one hour, then lift, add to the bath 3 lb. fluoride of chrome, re-enter the goods and work again for half an hour; lift, wash and dry. _Bright Cherry Red_.--Make a dye-bath with 4 lb. Benzo Fast Red, 10 lb. Glauber's salt, and 2 lb. acetic acid. Work at the boil for one hour, then lift, add 3 lb. fluoride of chrome, re-enter the goods and work for half an hour longer; wash and dry. _Cherry Red_.--Make the dye-bath with 2 lb. Azo Fuchsine G, 1-1/2 lb. Fast Yellow, 10 lb. Glauber's salt, and 2 lb. sulphuric acid. Work at the boil for one hour. _Bluish Bordeaux Red_.--For a very fast shade use 8 oz. Fast Acid Violet R, 8 oz. Orange G, 3/4 oz. Patent Blue B, 10 lb. Glauber's salt, and 2 lb. sulphuric acid. Work at the boil for one hour. _Bright Bordeaux Red_.--A good bright and fast shade of red is dyed with 3-1/2 lb. Emin Red and 7 lb. bisulphate of soda. Work at the boil for one hour, then lift, add 3 lb. fluoride of chrome, work for three-quarters of an hour, then lift, wash and dry. _Bordeaux Red_.--Use 3 lb. Titan Scarlet D, 1/4 lb. Titan Brown O, and 20 lb. salt. Work at the boil for one hour, then lift, wash and dry. #Claret Reds.#--Claret reds are very useful shades and are great favourites of the dress-loving public. They are dark reds of a yellow tone, and can be dyed upon wool in a variety of ways, of which the following recipes just indicate a few. _Claret_.--Make the dye-bath with 4 lb. Milling red R, 10 lb. Glauber's salt, and 4 lb. sulphuric acid. _Claret_.--Use 4 lb. Archil Substitute N, 10 lb. Glauber's salt, and 2 lb. sulphuric acid. _Claret_.--Make the dye-bath with 2 lb. Bordeaux B L, 10 lb. Glauber's salt, and 2 lb. sulphuric acid. _Claret_.--A deep shade is dyed with 2-1/2 lb. Victoria Scarlet R, (p. 111) 2 lb. Victoria Rubine O, 1 oz. Cyanine Scarlet R, 2 lb. Victoria Rubine O, 1 oz. Cyanine B, 10 lb. Glauber's salt, and 2 lb. sulphuric acid. _Claret_.--A fine deep shade is dyed with 2 lb. Azo Red A, 1/4 lb. Orange extra, 1/4 lb. Cyanole, 10 lb. Glauber's salt, and 2 lb. sulphuric acid. #Maroon Reds.#--From clarets to maroons is not a wide interval, they are both dark shade reds, the former tending to a yellow tone, the latter to a more bluish shade of red. A few recipes will be given to show some of the best methods of dyeing maroons. _Maroon_.--Use 6 lb. Amaranth B, 10 lb. Glauber's salt, and 2 lb. sulphuric acid. This gives a fine bright shade. _Deep Maroon_.--Make the dye-bath with 4-1/2 lb. Fast Acid Violet 10 B, 80 lb. Glauber's salt, and 3 lb. sulphuric acid. This gives a fine blue shade of maroon of great depth. _Maroon_.--The dye-bath is made with 3 lb. Azo acid violet 4 R, 1 lb. Fast Yellow S, 1-1/2 oz. Fast Green Bluish, 10 lb. Glauber's salt, and 2 lb. sulphuric acid. _Deep Maroon_.--Make the dye-bath with 2 lb. Acid Magenta, 1/2 lb. Orange O, 1/2 lb. Patent Blue V, 10 lb. Glauber's salt, and 2 lb. sulphuric acid. _Deep Maroon_.--Make a dye-bath with 3 lb. Azo Acid Rubine, 1-1/2 oz. Acid Black B B, 10 lb. Glauber's salt, and 2 lb. sulphuric acid. _Maroon_.--The dye-bath is made with 3 lb. Milling Red B, 1-1/2 oz. Naphthol Black 4 R, 10 lb. Glauber's salt, and 3 lb. sulphuric acid. _Deep Maroon_.--Make the dye-bath with 1-1/2 lb. Victoria Scarlet R, 13 oz. Victoria Rubine O, 1/2 lb. Victoria Yellow, 2 lb. Keton Blue G, 10 lb. Glauber's salt, and 3 lb. sulphuric acid. _Bright Red_.--A good shade is dyed with 4 lb. Lanafuchsine S G, and 10 lb. bisulphate of soda. Lanafuchsine S B dyes somewhat bluer shades. _Fast Red_.--Dye with 4 lb. Milling Red B, 10 lb. Glauber's salt, (p. 112) and 2 lb. sulphuric acid. _Bright Scarlet_.--Dye with 3 lb. Brilliant Cochineal 2 R, 10 lb. Glauber's salt, and 3 lb. sulphuric acid. _Deep Scarlet_.--Dye with 3 lb. Brilliant Ponceau 4 R, 10 lb. Glauber's salt, and 2 lb. sulphuric acid. #Pinks.#--_Pink_.--Use 1-1/2 oz. Erythesine D, and 5 lb. acetic acid. These two pinks are very much alike and are very bright. _Bluish Pink_.--Use 1-1/2 oz. Rose Bengale and 5 lb. acetic acid. _Pink_.--Make the dye-bath with 3 oz. Azo Cochineal, 10 lb. Glauber's salt, and 2 lb. sulphuric acid. _Bluish Pink_.--Make the dye-bath with 3/4 to 1 oz. Fast Acid Violet R and a little Orange G, 10 lb. Glauber's salt, and 2 lb. sulphuric acid. _Pink_.--By using 1-1/2 oz. Fast Acid Violet R, 3/4 oz. Orange G, 10 lb. Glauber's salt, and 2 lb. sulphuric acid, a good full pink is obtained. _Bluish Pink_.--Use 2 oz. Fast Acid Violet R, 10 lb. Glauber's salt, and 2 lb. sulphuric acid. Many of the other acid reds may be used for dyeing pinks if from 2 to 4 oz. of dye-stuff be used. _Pink_.--Use in the dye-bath 1-1/2 oz. Diamine Fast Red F, 5 lb. acetate of soda, and 3 lb. bisulphate of soda. _Coral Red_.--Make the dye-bath with 1/2 lb. Diamine Scarlet B, 10 lb. Glauber's salt, and 1 lb. acetic acid. _Dark Cherry Red_.--The dye-bath is made with 2-1/2 lb. Orange G G, 1 lb. Brilliant Orseille C, 3/4 oz. Cyanole extra, 10 lb. Glauber's salt, and 2 lb. sulphuric acid. _Deep Crimson_.--Use in the dye-bath 4 lb. Brilliant Orseille C, 1-1/2 oz. Cyanole extra, 3 oz. Orange G G, 10 lb. Glauber's salt, and 2 lb. sulphuric acid. _Scarlet_.--Make the dye-bath with 4 lb. Lanafuchsine S G, and 10 lb. bisulphate of soda. Work at the boil to shade. _Crimson_.--Make the dye-bath with 4 lb. Lanafuchsine S B, and (p. 113) 10 lb. bisulphate of soda. Work at the boil to shade. The Lanafuchsines, of which there are three brands, S G, S B, and 6 B, dye very good level shades of red from scarlet to crimson, which are of good fastness to milling, acids and light. _Salmon_.--Use 1/2 lb. Rhodamine B, 1/4 oz. Naphthol Yellow S, 10 lb. Glauber's salt, and 2 lb. acetic acid. _Rose Red_.--Use 1/4 lb. Lanafuchsine S B, 3 oz. Lanafuchsine S G, 10 lb. Glauber's salt, and 1 lb. sulphuric acid. _Salmon Red_.--Use 1-1/2 oz. Lanafuchsine S G, 1/4 oz. Fast Yellow S, 10 lb. Glauber's salt, and 1/2 lb. sulphuric acid. _Deep Crimson_.--The dye-bath is made with 2 lb. Naphthol Red C, 9 oz. Acid Magenta, 3/4 oz. Cyanole extra, 10 lb. Glauber's salt, and 2 lb. sulphuric acid. _Purple Red_.--Dye with 2-1/2 lb. Naphthol Red C, 3/4 lb. Acid Magenta, 1 oz. Cyanole extra, 10 lb. Glauber's salt, and 2 lb. sulphuric acid. _Bordeaux Red_.--Dye with 4 lb. Lanafuchsine S B, 1 oz. Orange extra, 10 lb. Glauber's salt, and 2 lb. sulphuric acid. _Fawn Red_.--Dye with 1/4 lb. Orange G G, 3 oz. Lanafuchsine S B, 1/2 oz. Cyanole extra, 10 lb. Glauber's salt, and 2 lb. sulphuric acid. _Salmon_.--Prepare the dye-bath with 1/4 oz. Fast Acid Violet R, 1/2 oz. Orange G, 10 lb. Glauber's salt, 1 lb. sulphuric acid. Work at the boil to shade. The mordant reds are fairly numerous, and include both natural and artificial red dye-stuffs. The principle or property on which the application of this group of dye-stuffs to the dyeing of textile fabrics depends is that they are of an acid character and combine with metallic oxides, like those of iron, aluminium, or chromium to form insoluble coloured bodies, or "colour lakes" as they are called. The shade or tint of these colour lakes depends, firstly, upon the (p. 114) dye-stuff, and, secondly, upon the metallic oxide. Thus Alizarine with alumina gives a scarlet, with chrome a dark red, and with iron a dull violet. Alumina and chrome are the metallic mordants most commonly used in the dyeing of reds; sometimes tin is used, but never iron. The coal-tar colour makers have placed at the service of dyers a great variety of mordant dyes, which may be classified somewhat roughly into groups, according to their chemical composition. The first group is called phenolic colours. These contain the group, or radical OH, hydroxyl, once or oftener. It is to the presence of this group that they owe their acid character and the property of combination with metallic oxides. To this group of dye-stuffs belong such dyes as Alizarine, Alizarine Cyanine, Anthragallol, Gambine, Coerulein, and some others. The natural red dye-stuffs, Cochineal, Brazil-wood, madder, etc., probably belong to this class. None of these are essentially dyes of themselves, and used alone will not dye any fibre, it is only when they are brought into combination with the mordant that they will dye the wool fibre. The next group may be called hydroxy-azo dyes, and are quite of modern introduction. They are azo dyes, one of whose constituents is a body like salicylic acid, amido-benzoic acid, dihydroxy-naphthalene-sulpho acid, which contain the group OH, hydroxyl with carboxyl COOH. The first group imparts phenolic characters, while the second gives true acid properties, and both of these acting together cause the dyes to be able to form colour lakes with metallic oxides. There is one point of difference between the two groups of dyes, the phenolic dyes are as a rule not dyes of themselves, some of them are practically free from colour, and it is only when brought into combination with the metallic oxide or mordant that they form a colour and dye a fibre. On the (p. 115) other hand the azo mordants are in general colouring matters, and can be used to dye wool without the aid of a mordant, the latter only serving to make the colour faster to light, acids, milling, etc., and it often has no material effect on the shade or tone of colour being dyed. Alizarine Yellow G G, Gambine Yellow, Anthracene Yellow, Chrome Violet, are examples of such dyes. There are, however, some dyes (such as the Chromotrops, Azofuchsine, Anthracene Acid Browns, etc.) on which the mordant has a marked effect. The methods adopted in practice for the application of this class of dyes are many and varied. The mordants used are alum, alumina sulphate, acetate of chrome, chrome alum, fluoride of chrome, ferrous sulphate and tin chloride, while, in addition, along with these true mordanting materials, assistant mordants are used, such as argol, tartar, tartaric acid, lactic acid, lignorosine, oxalic acid and sulphuric acid. The mordanting may be done either before or after the dyeing, the first plan being that commonly adopted with the phenolic colours, while the second method may be used and is the best to use with azo-mordant dyes. Sometimes the mordanting and dyeing may be done in one bath, but this method is one which leads to a loss of colouring matter and often to the production of colours which are loose to rubbing, and cannot, therefore, be recommended. #Mordanting.#--This operation is carried out in the same way in all cases. The goods are entered into the bath at a temperature of about 150° F. The heat is raised to the boil, and is then maintained for one and a half hours, after which the mordanted wool is lifted and well rinsed, when it is ready for the dye-bath. As mordanting materials bichromate of potash and fluoride of chrome are chiefly used when chrome mordants are required, sometimes chrome alum. With these (p. 116) are used sulphuric acid, oxalic acid, cream of tartar or argol, lactic acid, etc. Which of these are used depends entirely on the results which are to be got and the dye-stuff to be used, more particularly is this the case when bichromate of potash is the mordanting material. When sulphuric acid is used as the assistant along with the bichrome, then there is formed on the wool fibre a deposit of chromic acid and chromium oxide, and this exerts an oxidising effect on the colouring matter or dye-stuff, which in some cases, as the Alizarine Blue, Alizarine Yellow, etc., leads to a destructive effect, and, therefore, the production of weak shades, so that it is not possible always to use an oxidising mordant. When tartar, argol, oxalic acid, lactic acids and other assistants of an organic nature are used, then a different effect is obtained, the bichromate is completely decomposed, and a deposit of chromium oxide formed on the wool. This does not exert any action on the colouring matter, and hence this mordant is known as the non-oxidising mordant. It may be pointed out that when wool is mordanted with potassium or sodium bichromate and sulphuric acid (oxidising mordant) it has a deep yellow colour, while when mordanted with bichromate or other chrome salt, and the organic assistants enumerated above (non-oxidising mordant), it has a green colour, and one sign of a well-mordanted wool is when it has a good bright tone free from yellowness. Of the organic assistants tartar is undoubtedly the best in general use, and, although slow in its action, leaves a good deposit of oxide of chrome on the wool in a suitable condition to develop the best results on dyeing. Argols are only an impure tartar. They can only be used when dark shades are to be dyed. Oxalic acid does not work as well as tartar, and there is not so much chrome oxide deposited on the wool, while there is a slight tendency for a small proportion of this to be in the form of chromic acid. Of late years lactic acid and (p. 117) lignorosine have been added to the list of assistant mordants; both these give excellent results, they lead to a more complete and more uniform decomposition of the bichromate, and therefore the mordanting baths are more completely exhausted, so that rather less bichromate is required; the shades which are obtained are in general fuller and brighter. Examples of the use of these assistants will be found among the recipes given below. With fluoride of chrome either oxalic acid or tartar is used, and a deposit of chromium oxide is formed on the wool, the general effect being the same as when bichromate of potash is used with oxalic acid or tartar. Alumina is applied either in the form of alum or of sulphate of alumina, argol or tartar being used as the assistant, oxide of alumina being deposited on the fibre. When ferrous sulphate (copperas) is used then tartar is almost invariably used as the assistant mordant, oxalic acid only rarely. The dyeing with mordant dyes must be done in a special way and with great care, if uniform, level shades and fast colours are to be obtained. The dye-bath must be started cold, and the wool be entered and worked for twenty to thirty minutes, the object being to cause the dye-stuffs to penetrate well into the substance of the fibre, then the temperature is slowly raised to the boil, not less than three-quarters of an hour being taken in doing so; the temperature is maintained at the boil for fully one and a half hours longer. During the boiling operation the mordant and dye-stuff combine together, and form the characteristic colour lake, and the boiling fixes this firmly on to the wool. The water used plays a very important part. If too hard in character, the lime it contains shows a tendency to combine with the (p. 118) dye-stuff and form a colour lake, which is deposited in a loose form on the wool or in the bath, tending to make the shades dull and loose to rubbing. This defect can be remedied by adding a little acetic acid to the dye-bath, say about 3 lb. to 100 gallons of the water. It combines with and neutralises the influence of the lime, in so far as the formation of a loose colour lake is concerned; still the lime does unite with the dye-stuff, but the combination is formed more slowly, and in or on the wool fibre so that it is fast. By working in the manner laid down above very fast shades can be dyed on wool with mordant dyes, and the following recipes will give the other details as to tints, shades, quantities, etc., not noted above. _Claret_.--Mordant, 2 lb. bichromate of potash and 2 lb. tartar; dye, 8 lb. Alizarine Claret R. _Fawn_.--Mordant, 3 lb. bichromate of potash and 1-1/2 lb. tartar; dye, 3 lb. Alizarine Orange N. _Maroon_.--Mordant, 3 lb. bichromate of potash and 2-1/2 lb. tartar; dye, 15 lb. Alizarine Orange N. _Deep Crimson_.--Mordant, 3 lb. bichromate of potash and 2-1/2 lb. tartar; dye, 8 lb. Alizarine Red 1 W S. _Lilac Rose_.--Mordant, 1-1/2 lb. bichromate of potash and 1-1/2 lb. tartar; dye, 1 lb. Alizarine Red 1 W S. _Crushed Strawberry Tint_.--Mordant, 2 lb. bichromate of potash and 1-1/2 lb. tartar; dye, 3 lb. Alizarine Red 2 W S. _Deep Claret_.--Mordant, 3 lb. bichromate of potash and 2-1/2 lb. tartar; dye, 5 lb. Alizarine Red 1 W S. _Bright Fawn Red_.--Mordant, 2 lb. bichromate of potash and 1-1/2 lb. tartar; dye, 1 lb. Alizarine Red 5 W S. _Scarlet_.--Mordant, 10 lb. alum and 6 lb. tartar; dye, 4 lb. Alizarine Red 5 W S. _Rose_.--Mordant, 6 lb. alum and 4 lb. tartar; dye, 1 lb. Alizarine Red 1 W S. _Deep Scarlet_.--Mordant, 10 lb. alum and 6 lb. tartar; dye, (p. 119) 4 lb. Alizarine Red 1 W S. _Deep Maroon_.--Mordant, 3 lb. bichromate of potash and 1 lb. sulphuric acid; dye, 5 lb. Alizarine Red 3 W S. _Bright Maroon_.--Mordant, 3 lb. bichromate of potash and 2 lb. tartar; dye, 5 lb. Alizarine Red S W, 10 lb. Mordant Yellow. _Deep Fawn Red_.--Mordant, 3 lb. bichromate of potash and 2-1/2 lb. tartar; dye, 10 lb. Alizarine Orange W and 1 lb. Mordant Yellow. These typical recipes are here given to show what tints may be obtained from the alizarine and the quantity of dye-stuffs required. By using other proportions of dye-stuffs than those given a variety of other tints may be dyed. The method of working described above is applicable to other mordant dyeing colours besides the alizarine reds, such as Alizarine Orange, Alizarine Blue, Anthracene Brown, Alizarine Cyanine, Galloflavine, Gambine, Chrome Violet, etc. It will therefore not be required to repeat this description of the process when the use of mordant colours for producing other colours, such as blues, navies, drabs, browns, etc., is dealt with. Although the shades dyed with the alizarines and allied colouring matters are lacking in the brilliance characteristic of the azo scarlets, yet they have the very great advantage of being quite fast to washing, acids and light. There is another method of using those alizarine reds that are sold in the form of powder, and which are distinguished by the letter S. They are of some value in dyeing heavy woollen cloths, and the method is indicated in the two recipes which follow:-- _Brilliant Scarlet_.--Prepare a dye-bath with 20 lb. Glauber's salt and 4 lb. Alizarine Red 1 W S, boil the wool in this for three-quarters of an hour; then lift, add to the same bath 4 lb. (p. 120) sulphuric acid, again work at the boil for three-quarters of an hour; then lift, add 10 lb. alum, re-enter the goods, and work three-quarters of an hour longer; then lift, wash and dry. _Claret_.--Prepare a bath with 20 lb. Glauber's salt and 4 lb. Alizarine Red 1 W S, boil for three-quarters of an hour; then lift, add 4 lb. sulphuric acid, re-enter the wool, boil for three-quarters of an hour; then lift, add 3 lb. bichromate of potash, re-enter the wool, and boil for three-quarters of an hour longer; then lift, wash and dry. _Bluish Red_.--Mordant, 2 lb. bichromate of potash and 2 lb. lactic acid; dye, 2 lb. Alizarine Red S. In this recipe there is used lactic acid as the assistant, and a very fine shade results. _Red_.--Mordant, 3 lb. lignorosine, 2 lb. bichromate of soda and 1 lb. sulphuric acid; dye with 12 lb. Alizarine Orange 2 G. _Dark Bordeaux Red_.--Mordant, 3 lb. lignorosine, 3 lb. bichromate of soda and 1-1/2 lb. sulphuric acid; dye, 12 lb. Alizarine S X. _Dark Red_.--Mordant, 3 lb. lignorosine, 2-1/2 lb. bichromate of soda and 1-1/4 lb. sulphuric acid; dye, 6 lb. Alizarine Orange 2 G and 4 lb. Alizarine S X. Lignorosine used as the assistant mordant in the above recipes works very well, and gives bright shades. _Fast Bordeaux_.--Prepare a bath with 4 lb. Chromogene I, 1-1/2 lb. Alizarine Red 1 W S, 1 lb. Alizarine Red 5 W S, 1/2 lb. Fast Acid Violet R, 10 lb. Glauber's salt and 3 lb. sulphuric acid. Work at the boil for one hour, then lift; add to the same bath 3 lb. bichromate of potash and 1-1/2 lb. sulphuric acid. Re-enter the goods and work to shade, then lift, wash and dry. _Terra Cotta_.--Make a dye-bath of 30 lb. Fustic, 8 lb. Turmeric, 30 lb. Sanders and 10 lb. Sumac. Boil the goods in this for one (p. 121) hour, then add 3 lb. sulphate of copper, previously dissolved in water, boil for one hour; cool, sadden with Copperas, using about 3-1/2 lb. or less if required; then rinse and dry. Another method is to mordant the goods at a boil for one and a half hours in 2 lb. bichromate of potash and 2 lb. tartar. Drain and wash. Dye in a fresh bath with 8 lb. sanders and 10 lb. fustic; afterwards sadden with 1/4 lb. copperas; allow to stand one hour; wash and dry. ORANGE SHADES ON WOOL. #With Direct Dyes.# Make a dye-bath with 2 lb. Titan Orange, 20 lb. Glauber's salt, and 1/2 lb. acetic acid. Work at the boil for one and a half hours, then lift, wash and dry. _Bright Orange_.--Dye with 1-1/2 lb. Benzo Orange R, 10 lb. salt, and 1 lb. acetic acid, working at the boil for one hour. _Orange_.--Dye with 2 lb. Chloramine Orange, 20 lb. salt, and a little acetic acid, working at the boil for one hour. _Orange_.--Dye with 2 lb. Diamine Orange G C, and 20 lb. Glauber's salt. _Pale Orange_.--Dye with 3 lb. Diamine Gold, 10 lb. Glauber's salt, and 5 lb. ammonium acetate. _Reddish Orange_.--Dye with 3 lb. Diamine Orange D C and 20 lb. Glauber's salt. _Orange_.--Dye with 2 lb. Diamine Scarlet B, 1 lb. Thioflavine S, and 20 lb. Glauber's salt. _Dark Orange_.--Dye with 1 lb. Diamine Red 5 B, 1 lb. Thioflavine S, and 20 lb. Glauber's salt. #With Acid Colours.# _Orange_.--Dye with 2 lb. Ponceau 3 G, 10 lb. Glauber's salt, and 2 lb. sulphuric acid. _Bright Orange_.--Dye with 2 lb. Mandarine G, 10 lb. Glauber's salt, and 2 lb. sulphuric acid. _Orange_.--Dye with 2 lb. Croceine Orange, 10 lb. Glauber's salt, and 2 lb. sulphuric acid. _Bright Orange_.--Use 3 lb. Orange G G, 10 lb. Glauber's salt, and (p. 122) 2 lb. sulphuric acid, boiling for one hour. _Orange_.--Use 3 lb. Orange R, 10 lb. Glauber's salt, and 2 lb. sulphuric acid. Work at the boil. Orange Extra will give a slightly less red tone of orange, Croceine orange gives a good bright shade of a yellowish tone. There are several brands of Orange dyes which can be used; they differ but little in shade from one another. In general they give fast colours. The Tropæolines also dye orange shades, but they are not so fast as the other dyes which have been named. _Gold Orange_.--Make a dye-bath with 1/2 lb. Diamine scarlet B, 2 lb. Anthracene Yellow C, 50 lb. Glauber's salt, 5 lb. acetate of ammonia. Enter the wool, work for half an hour, then add 3 lb. bisulphate of soda. Boil again for half an hour, then lift. Add 3 lb. fluoride of chrome, re-enter the wool, boil again for half an hour, then lift, wash and dry. This gives a very fast orange. #With Mordant Dyes.# _Old Gold_.--Mordant with 3 lb. bichromate of potash and 1 lb. sulphuric acid; dye with 6 lb. Alizarine Yellow R W. _Pale Orange_.--Mordant with 6 lb. alum and 4 lb. tartar; dye with 1 lb. Alizarine Orange G G. _Deep Orange_.--Mordant with 10 lb. alum and 6 lb. tartar; dye with 10 lb. Alizarine Orange N. This last dye-stuff gives a slightly redder shade of Orange than does the Alizarine Orange G. _Deep Orange_.--Dye in a bath with 1-3/4 lb. Azo Alizarine Orange R R, 10 lb. Glauber's salt, and 2 lb. sulphuric acid, and fix in the same bath with 1 lb. bichromate of potash. _Orange_.--Dye in a bath with 1 lb. Alizarine Red 1 W S, 2 lb. Mordant Yellow O, 10 lb. Glauber's salt, and 2 lb. sulphuric acid, then fix with 1-1/2 lb. bichromate of potash. _Orange_.--Dye in a bath with 1 lb. Anthracene Red, 2 lb. (p. 123) Alizarine Yellow, 10 lb. Glauber's salt and 2 lb. sulphuric acid. After dyeing fix with 2 lb. fluoride of chrome. _Gold Orange_. Mordant with 3 lb. bichromate of potash, and 2 lb. tartar, for one and a half hours at the boil; rinse. Then dye in a new bath with 1 lb. Alizarine Orange, 17 lb. Fustic extract. Work at 100° F. for half an hour, then heat gradually to the boil and dye for one and a half hours at that temperature; lift, rinse and wash. #Olive Yellow on Worsted Yarn.#--Mordant the yarn by boiling for one hour or one and a half hours in a bath of 3 lb. bichromate of potash; then dye in a bath of 1-1/2 lb. Gambine Yellow and 10 lb. of fustic chips. Red and orange form a kind of group of colours which shade off one into the other almost imperceptibly by using a range of dyes such as Croceine A Z, Brilliant Croceine 9 B, Brilliant Croceine 7 B, Brilliant Croceine 5 B, Brilliant Croceine 3 B, Brilliant Croceine M O O, Crystal Scarlet 6 R, Brilliant Cochineal 4 R, Brilliant Croceine B, Brilliant Cochineal 2 R, Orange E N Z, and Croceine Orange E N. It is possible to dye shades from a scarlet crimson to a bright orange. YELLOW SHADES ON WOOL. The number of yellow dye-stuffs is very great, and the variety of tints infinite. Yellow may be dyed with both natural and artificial dye-stuffs, and the recipes given will include examples showing the use of both kinds. Speaking generally, yellow dye-stuffs include amongst them some of the fastest colours known, and there is a larger proportion of fast yellow colouring matters than of any other class of dye-stuffs. #With Acid Yellows.# _Bright Yellow_.--Make the dye-bath with 1 lb. Fast Yellow F Y, 10 lb. Glauber's salt, and 2 lb. sulphuric acid, working at the boil to shade. _Olive Yellow_.--Prepare the dye-bath with 1 lb. Azo Carmine, (p. 124) 1-1/2 oz. indigo carmine, 1/2 lb. Fast Yellow, 10 lb. Glauber's salt, and 2 lb. sulphuric acid, working at the boil to shade. _Maize Yellow_.--Prepare a dye-bath with 5 lb. acetate of ammonia, 3 oz. Anthracene Yellow C, 1/4 oz. Diamine Fast Red F. Work for twenty minutes at the boil, then add 3 lb. bisulphate of soda; work half an hour longer, and then wash and dry. _Bright Canary_.--Prepare a dye-bath with 4 lb. bisulphate of soda, 1/2 lb. Nitrazine Yellow. Heat the bath to about 120° F., enter the goods and heat up to the boil, and work till the bath is exhausted, then lift; add to the dye-bath 3 lb. alum, 3 lb. tin spirits; re-enter the goods, and boil for twenty minutes longer; lift, wash and dry. _Bright Straw_.--Dye with 3 oz. Phenoflavine and 20 lb. bisulphate of soda. _Straw_.--Make the dye-bath with 1-1/4 oz. Azo Yellow, 1 dr. Cyanine B, 1 dr. Chromotrop 2 R, 10 lb. Glauber's salt, and 1 lb. sulphuric acid. _Greenish Straw_.--Dye with 1/4 oz. Cyanine B, 1 oz. Victoria Yellow, 1/4 oz. Chromotrop 2 B, 10 lb. Glauber's salt, and 1 lb. sulphuric acid. _Olive Yellow_.--Mordant with 3 lb. bichromate of potash and 1 lb. sulphuric acid; dye with 3 lb. Milling yellow O and 1 lb. acetic acid. _Bright Yellow_.--A good shade is dyed in a bath of 2 lb. Milling yellow O, 10 lb. Glauber's salt, and 2 lb. sulphuric acid, working at the boil. _Olive Yellow_.--Dye with 1-1/2 lb. Titan Yellow R, 10 lb. common salt, and 1 lb. acetic acid; after the colour has fully gone on to the wool, add to the bath 1-1/2 lb. fluoride of chrome and maintain at the boil for half an hour; then lift, wash and dry. _Deep Yellow_.--The dye-bath is made with 1-1/2 lb. Titan (p. 125) Yellow R, 10 lb. common salt, and 1 lb. acetic acid, working at the boil to shade. _Yellow_.--A good shade is dyed with 1-1/2 lb. Titan Yellow Y, 10 lb. common salt, and 1/2 lb. acetic acid, working at the boil to shade. _Golden Yellow_.--Mordant with 3 lb. bichromate of potash and 2 lb. tartar; dye with 1 lb. Anthracene Yellow C. _Deep Golden Yellow_.--Make the dye-bath with 3 lb. Anthracene Yellow C, and 3 lb. bisulphate of soda. Work at the boil for half an hour, then lift; add 3 lb. fluoride of chrome, re-enter the wool and work at the boil for another half-hour, then wash and dry. _Deep Olive Yellow_.--Mordant with 3 lb. bichromate of potash and 2 lb. tartar; dye with 20 lb. fustic extract. This gives a very deep shade of olive Yellow. _Bright Lemon Yellow_.--Make the dye-bath with 10 lb. Gambine Yellow, 7 lb. alum, and 2 lb. oxalic acid. Enter cold, then slowly heat to the boil and work to shade; then lift, wash and dry. _Leaf Yellow_.--Mordant with 3 lb. bichromate of potash and 1/2 lb. sulphuric acid; then dye with 2 lb. Gambine Y and 1 lb. Yellow N. _Deep Leaf Yellow_.--A somewhat deeper shade than the last is dyed by first mordanting with 2 lb. bichromate of potash and 1/2 lb. sulphuric acid, then dyeing with 2 lb. Gambine R and 1 lb. Yellow N. _Lemon Yellow_.--Prepare a bath with 40 lb. fustic, 6 lb. alum, 6 lb. tartar, and 3/4 lb. tin crystals; enter the wool and work at the boil for one and a half hours, then lift, wash and dry. _Olive Yellow_.--Mordant, 3 lb. bichromate of potash and 2 lb. tartar; dye, 3 lb. extract of fustic. _Deep Lemon_.--Mordant, 3 lb. bichromate of potash and 2 lb. tartar; dye, 1 lb. Alizarine Yellow G G W. _Golden Yellow_.--Mordant, 3 lb. bichromate of potash and 1 lb. (p. 126) sulphuric acid; dye, 10 lb. Alizarine Yellow G G W. _Light Straw_.--Make the dye-bath with 3 oz. Anthracene Yellow B N, 5 lb. acetate of ammonia, and 3 lb. bisulphate of soda; work at the boil to shade, then lift, wash and dry. _Old Gold_.--A very fine shade of old gold is obtained by dyeing in a bath of 3 lb. Anthracene Yellow C, 5 lb. acetate of ammonia, and 3 lb. bisulphate of soda. Work at the boil for three-quarters of an hour, then lift; add to the dye-bath 3 lb. fluoride of chrome, re-enter the wool, and work for one and a half hours longer at the boil; lift, wash and dry. _Deep Yellow_.--Mordant, 3 lb. bichromate of potash and 2-1/2 lb. tartar; dye, 2 lb. Mordant Yellow D. _Pale Olive Yellow_.--Dye with 3 lb. Anthracene Yellow G G, 10 lb. Glauber's salt, and 2 lb. acetic acid; after the dye-bath is exhausted of colour add 3 lb. fluoride of chrome, and work at the boil half an hour longer. _Gold Yellow_.--Dye with 3 lb. Anthracene Yellow B N, 10 lb. Glauber's salt, and 3 lb. acetic acid; after half an hour's boil, add 1-1/2 lb. bichromate of potash, work for half an hour longer. _Gold Yellow_.--Dye with 2 lb. Indian Yellow R, 10 lb. Glauber's salt, and 2 lb. sulphuric acid. GREEN SHADES ON WOOL. Of green shades there is an infinite variety, and these can be dyed in several ways. Either a simple green dye-stuff may be used or mixtures of blue and yellow dye-stuffs may be employed, this latter method being extremely common. It is somewhat interesting to notice that, notwithstanding the great prevalence of green in Nature, the dyer has at his command no natural green dye-stuff, but must, if he prefers to adopt natural dye-stuffs, use a mixture of blue and yellow dye-stuffs to produce green shades. There are but few green colouring (p. 127) matters derived from coal tar: Gambine, Dinitroso-resorcine, Alizarine Green, Brilliant Green, Malachite Green, Azo Green, Fast Green, Naphthol Green, Acid Green, Diamine Green, Benzo Green almost exhaust the list. Compared with the numerous red and blue dyes which are obtained from coal-tar products, green dyes are conspicuous by their fewness. On the other hand, the dyer has in the blue and yellow dyes from coal tar a means of producing any tint or shade of green he may require. Members of all the classes of basic, direct, acid, azo and mordant dyes, can be found among the dye-stuffs which can be used in dyeing green, and the methods and principles of their application have been fully described in previous pages. The following recipes contain all the practical information that is needed:-- #With Direct Dyes.# _Dark Green_.--The dye-bath is made with 1 lb. Titan Blue 3 B, 1 lb. Titan Yellow Y, 2 lb. salt, and 1/2 lb. acetic acid. _Bright Green_.--Prepare a dye-bath with 1 lb. Titan Yellow G, 1 lb. Titan Blue 3 B, 20 lb. salt, and 1/2 lb. acetic acid, working at the boil for one hour. _Dark Green_.--Make a dye-bath with 4 lb. Acid Blue 4 S, 2 lb. Titan Yellow Y, and 5 lb. acetate of ammonia, working at the boil to shade. _Blue Green_.--Make the dye-bath with 6 lb. Acid Blue 4 S, 2-1/2 lb. Titan Yellow Y, and 5 lb. acetate of ammonia, working at the boil to shade. _Bottle Green_.--The dye-bath is made with 5 lb. Acid Blue 4 S, 2-1/2 lb. Titan Yellow Y, and 5 lb. acetate of ammonia, working at the boil to shade. The greens shown in the last three recipes are of a very satisfactory character, and show how, by the use of acetate of ammonia in the dye-bath, the direct dyeing Titan colours can be combined with acid colours. _Green_.--Make the dye-bath with 5 lb. Glauber's salt, 5 lb. (p. 128) acetate of ammonia, 2 lb. Sulphon Cyanine, and 1-1/2 lb. Chrysophenine. _Dark Green_.--The dye-bath is made with 2 lb. Sulphon Cyanine, 3/4 lb. Chrysophenine, 5 lb. Glauber's salt, and 5 lb. acetate of ammonia. _Pale Russian Green_.--Make the dye-bath with 1/2 lb. Sulphon Cyanine, 2-1/2 oz. Chrysophenine, and 10 lb. Glauber's salt. The last three shades have the merit of being fast to milling, and fairly so to light. _Olive_.--Make a dye-bath with 1 lb. Nyanza Black B, 1 lb. Chrysamine, and 20 lb. Glauber's salt. Work at the boil to shade, lift, wash and dry. #With Acid Dyes.# _Blue Green_.--Make a dye-bath with 10 lb. Glauber's salt, 2 lb. sulphuric acid, 2 lb. Patent Blue N, and 1 lb. Azo Yellow, working at the boil. _Sage Green_.--The dye-bath is made with 10 lb. Glauber's salt, 2 lb. sulphuric acid, 2 lb. Azo Yellow, and 1 lb. Patent Blue N, working at the boil. _Olive Green_.--Make the dye-bath with 3 lb. Naphthol Green B, 10 lb. Glauber's salt, 15 lb. bisulphate of soda, and 1 lb. copperas, working at the boil to shade. _Bright Green_.--Make the dye-bath with 10 lb. Glauber's salt, 5 lb. bisulphate of soda, and 1-1/2 lb. Acid Green B, working at the boil to shade. _Emerald Green_.--The dye-bath is made with 1/2 lb. Acid Green B, 10 lb. Glauber's salt, and 2 lb. sulphuric acid. The wool might also be previously mordanted with 15 lb. hyposulphite of soda, and 5 lb. sulphuric acid at the boil for one and a half hours, when it will give a bright shade of emerald green. _Grass Green_.--Dye a medium indigo bottom on the wool from the vat, then dye in a bath with 1 lb. Milling Yellow O, 5 lb. Glauber's salt, and 5 lb. bisulphate of soda; lift, wash and dry. The last recipe shows the use of the indigo vat in giving the blue (p. 129) constituent in dyeing greens and other compound colours on wool. This, while being a very effective method of dyeing, yet necessitates two operations which add very materially to the cost of dyeing such shades, hence it is not used for dyeing low class woollen fabrics, but for better class goods it is frequently adopted, fast colours being thus obtained. In thus using the indigo vat as a bottom dye regard to the properties of indigo must be paid in carrying out any subsequent dyeing operation, so that the indigo on the fibre be not destroyed. As a rule, the indigo will resist any ordinary baths made with Glauber's salt, acetate of ammonia, sulphuric or acetic acids, but it will not resist mordanting operations with bichromate of potash, for the latter salt destroys the indigo. Fluoride of chrome, chrome acetate, or alum, may be used as mordants if necessary. _Pale Sea Green_.--The dye-bath contains 1 oz. Cyanine B, 1 oz. Azo Yellow, 5 lb. Glauber's salt, and 1 lb. sulphuric acid. _Moss Green_.--The dye-bath is made with 1/2 oz. Chromotrop 2 R, 2 oz. Cyanine B, 4 oz. Fast Acid Blue R, 3-1/4 oz. Azo Yellow, 5 lb. acetic acid, and 10 lb. Glauber's salt. _Deep Moss Green_.--Prepare the dye-bath with 4-1/2 oz. Cyanine B, 9 oz. Fast Acid Blue R, 4-1/2 oz. Azo yellow, 1/2 oz. Chromotrop 2 R, 5 lb. acetic acid, and 10 lb. Glauber's salt. _Blue Green_.--A very fine shade of blue green is dyed with 9-1/2 oz. Cyanine B, 1-1/4 lb. Fast Acid Blue R, 4 oz. Azo Yellow, 5 lb. acetic acid, and 10 lb. Glauber's salt. _Emerald Green_.--A pale, but brilliant shade of green is dyed with 1-1/4 oz. Patent Blue V, 4-1/4 oz. Azo Yellow, 10 lb. Glauber's salt, and 2 lb. sulphuric acid. _Bright Leaf Green_.--Dye in a bath with 13 oz. Victoria Yellow, (p. 130) 1/2 lb. Patent Blue V, 1/2 oz. Chromotrop 2 R, 10 lb. Glauber's salt, and 2 lb. sulphuric acid. _Deep Leaf Green_.--The dye-bath is made with 22 oz. Cyanine B, 1 lb. Azo Yellow, 2-1/2 oz. Chromotrop 2 R, 10 lb. Glauber's salt, and 2 lb. sulphuric acid. _Bright Peacock Green_.--The dye-bath is made with 5 oz. Chromotrop 6 B, 4 oz. Patent Blue V, 7 oz. Azo Yellow, 10 lb. Glauber's salt, and 2 lb. sulphuric acid. _Dark Beige Green_.--Make the dye-bath with 1/2 lb. Fast Green Bluish, 6 oz. Fast Yellow F Y, 4-1/2 oz. Azo Fuchsine G, 10 lb. Glauber's salt and 2 lb. sulphuric acid. _Invisible Green_.--Make the dye-bath with 1-1/2 lb. Fast Green Bluish, 1-1/4 lb. Fast Yellow F Y, 1 lb. Azo Fuchsine G, 10 lb. Glauber's salt and 2 lb. sulphuric acid. _Pale Sage Green_.--Make the dye-bath with 1 lb. Azo Acid Brown, 1/2 lb. Fast Acid Violet 10 B, 10 lb. Glauber's salt and 2 lb. sulphuric acid. _Bright Grass Green_.--Make a dye-bath with 10 lb. Glauber's salt, 2 lb. sulphuric acid, 3/4 lb. Phenoflavine, 3/4 lb. Azo Carmine B, and 5-3/4 lb. extract of indigo. _Moss Green_.--Prepare a dye-bath with 1 lb. Azo Acid Brown, 1/4 lb. Fast Acid Violet 10 B, 10 lb. Glauber's salt and 2 lb. sulphuric acid. _Dark Sage Green_.--Make the dye-bath with 3 lb. Azo Acid Brown, 1/2 lb. Fast Acid Violet 10 B, 10 lb. Glauber's salt and 2 lb. sulphuric acid. _Emerald Green_.--A fine shade of emerald green can be dyed in a bath which is made from 1/2 lb. Fast Green Bluish, 1 lb. Fast Yellow F Y, 1 lb. Acid Violet 6 B, 10 lb. Glauber's salt and 2 lb. sulphuric acid. _Bottle Green_.--Make a dye-bath with 1-1/2 lb. Victoria Violet 8 B S, 3/4 lb. Victoria Yellow, 2 oz. Naphthol Yellow S, 1 oz. Fast Acid Violet R, 1/2 oz. Cyanine B, 10 lb. Glauber's salt and 2 lb. sulphuric acid. Work for one hour at the boil, then lift; add 3 lb. fluoride (p. 131) of chrome, re-enter the wool, and work for half an hour at the boil. _Pale Pea Green_.--A fine bright shade is dyed in a bath containing 1-1/2 oz. Cyanole, 3/4 oz. Naphthol Yellow and 10 lb. bisulphate of soda. By increasing the quantity of dye-stuff in proportion to the material, fine deep shades of green can be dyed. _Deep Electric Green_.--Make the dye-bath with 2 lb. Cyanole, 1 lb. Indian Yellow G and 10 lb. bisulphate of soda, working at the boil for one hour; then lift, wash and dry. #With Mordant Dyes.# _Green_.--Mordant with 10 lb. alum, 1 lb. bichromate of potash and 16 lb. tartar. Dye with 10 lb. indigo extract, 2 lb. fustic extract and 3 lb. alum, working at the boil; lift, wash and dry. _Dark Green_.--Mordant with 3 lb. bichromate of potash, 8 lb. alum and 3 lb. tartar. Dye with 10 lb. extract of indigo, 2 lb. extract of fustic and 3 lb. alum, working at the boil. _Sea Green_.--Mordant with 3 lb. bichromate of potash and 2-1/2 lb. tartar at the boil for one and a half hours. Dye with 1-1/4 lb. Alizarine Blue D N W, 3-3/4 lb. Alizarine Yellow and 5 oz. Alizarine Brown, at the boil for two hours. _Bronze Green_.--Make a dye-bath with 2 lb. Cyanole extra, 2 lb. Tropeoline O, 1 lb. Archil Substitute N and 10 lb. bisulphate of soda, working at the boil to shade. _Green_.--A very fine shade of green is dyed as follows: Mordant with 3 lb. bichromate of potash and 2-1/2 lb. tartar. Dye with 4 lb. Alizarine Blue D N W, 1-1/2 lb. Patent Blue A and 2-3/4 lb. Alizarine Yellow. _Blue Green_.--Mordant as in the last recipe. Dye with 6 lb. Alizarine Blue D N W, 1-1/2 lb. Patent Blue A, and 1-1/4 lb. Alizarine Yellow G G W. _Bright Pale Sage Green_.--Mordant with 3 lb. bichromate of potash and 2 lb. sulphuric acid. Dye with 5 lb. Alizarine Yellow G G W, (p. 132) 3/4 lb. Alizarine Brown and 1-1/4 lb. Alizarine Blue D N W. _Deep Sage Green_.--Mordant with 3 lb. bichromate of potash and 2-1/2 lb. tartar. Dye with 4 lb. Alizarine Yellow G G W, 3-1/4 lb. Anthracene Brown and 2-1/4 lb. Alizarine Blue D N W. _Pale Sea Green_.--Mordant with 2 lb. bichromate of potash and 1-1/2 lb. tartar. Dye with 1 lb. Coeruleine B. _Bottle Green_.--Mordant with 3 lb. bichromate of potash and 2-1/2 lb. tartar. Dye with 20 lb. Coeruleine S W. _Slate Green_.--Mordant with 2 lb. bichromate of potash and 1-1/2 lb. tartar. Dye with 3 lb. Alizarine Green S. _Invisible Green_.--Mordant with 3 lb. bichromate of potash and 2-1/2 lb. tartar. Dye with 17-1/2 lb. Alizarine Green S. _Peacock Green_.--Mordant with 3 lb. bichromate of potash and 2-1/2 lb. tartar. Dye with 8 lb. Alizarine Green S. _Dark Bottle Green_.--Mordant with 4 lb. bichromate of potash and 3 lb. tartar. Dye with 15 lb. Anthracene Blue W G, and 1-1/2 lb. Mordant Yellow. _Invisible Green_.--Mordant with 3-1/2 lb. bichromate of potash and 2-1/2 lb. tartar, working at the boil for one and a half hours. Dye with 20 lb. Alizarine Green S W, and 1 lb. acetic acid. _Sage Green_.--Give a medium indigo ground to the wool in a vat, then dye for one hour at the boil in a vat containing 1/2 lb. Anthracite Black B, 2 lb. Anthracene Yellow C, 2 oz. Diamine Fast Red F, and 5 lb. acetate of ammonia; then lift, add 3 lb. fluoride of chrome, re-enter into the dye-bath and work half an hour longer at the boil; lift, wash and dry. _Peacock Green_.--Give a medium indigo bottom on the vat, then dye for one hour at the boil in a dye-bath made with 1/2 lb. Anthracene Yellow C, 2 oz. Diamine Fast Red F, and 5 lb. acetic acid; then lift, add 3 lb. fluoride of chrome, work for half an hour longer at the boil, then lift, wash and dry. _Bottle Green_.--Mordant by boiling in a bath of 3 lb. copperas (p. 133) and 1 lb. oxalic acid. Dye in a bath with 15 lb. Gambine R. _Light Green_.--Mordant with 3 lb. copperas and 1 lb. oxalic acid. Dye with 2-1/2 lb. Gambine Y. _Medium Green_.--Mordant as in the last dye with 10 lb. Gambine Y. _Deep Grass Green_.--Mordant with 3 lb. bichromate of potash and 2-1/2 lb. tartar. Dye with 9 lb. Coerulein and 1-3/4 lb. Galloflavine. _Bright Grass Green_.--Mordant with 4 lb. copperas and 1 lb. oxalic acid. Dye with 5 lb. Gambine Y, 1/2 lb. Yellow N, and 2 lb. bisulphate of soda. Shades dyed with Gambine are very fast to milling and light. _Pale Sage Green_.--Mordant with 3 lb. bichromate of potash and 1 lb. tartar. Dye with 1/2 lb. Milling Yellow O, 2 lb. Alizarine Black S W, and 2 lb. acetic acid. _Medium Green_.--Mordant with 2-1/2 lb. bichromate of potash and 1-1/2 lb. oxalic acid. Dye with 1-1/2 lb. Diamond Yellow B, 3-1/2 lb. Brilliant Alizarine Blue G, and 1 lb. acetic acid. _Invisible Bronze Green_.--Give a medium bottom on the indigo vat and then mordant with 3 lb. fluoride of chrome and 2 lb. tartar. Finally dye with 3 lb. Alizarine Bordeaux S, and 4 lb. Diamond Flavine, working at the boil for two hours. _Pale Slate Green_.--Mordant with 3 lb. bichromate of potash and 2-1/2 lb. tartar, and then dye with 1 lb. Alizarine Blue D N W, Alizarine Yellow and 5 oz. Alizarine Brown. _Light Green_.--Mordant in the usual way with 2-1/2 lb. bichromate of potash and 2 lb. tartar. Dye with 1 lb. Methylene Blue and 1 lb. fustic extract, working at the boil. _Fast Green_.--Mordant with 8 lb. alum, 2 lb. bichromate of potash, 2 lb. sulphuric acid and 3/4 lb. tin salt. Dye with 20 lb. indigo (p. 134) extract and 10 oz. fustic extract, working at the boil for one and a half hours. _Bottle Green_.--Mordant with 3 lb. bichromate of potash and 2-1/2 lb. tartar. Dye with 4 lb. extract of fustic, 1 lb. extract of logwood, and 2 oz. Anthracene Red. Work for one and a half hours, then add 3/4 lb. copperas, and work for half an hour longer. _Dark Green_.--Mordant with 3 lb. bichromate of potash and 2-1/2 lb. tartar. Dye with 1-1/2 lb. Methylene Blue, 1-1/2 lb. extract of logwood, and 4 lb. extract of fustic, working at the boil for two hours. _Olive_.--Prepare a dye-bath with 1-1/2 lb. Yellow N, 1/4 lb. Archil Substitute, 4 lb. extract of indigo, 10 lb. Glauber's salt, 2 lb. sulphuric acid, and 2 lb. alum, working at the boil to shade. _Bright Green_.--Prepare a dye-bath containing 8 oz. Acid Green Extra and 10 per cent. bisulphate of soda. Enter at 130° F., raise to the boil, boil for three-quarters of an hour, and rinse. _Bluish Green_.--Prepare a dye-bath containing 8 oz. Fast Acid Green B N and 10 lb. bisulphate of soda. Enter at 130° F., raise to the boil, boil for three-quarters of an hour, and rinse. _Bluish Green_.--Prepare a dye-bath containing 8 oz. Cyanole Green 6 G and 10 lb. bisulphate of soda. Enter at 130° F., raise to the boil, boil for three-quarters of an hour, and rinse. _Turquoise Green_.--Prepare a dye-bath containing 8 oz. Cyanole Green B and 10 lb. bisulphate of soda. Enter at 130° F., raise to the boil, boil for three-quarters of an hour, and rinse. _Slate Green_.--Mordant the wool by boiling for one and a half (p. 135) hours in a bath containing 3 lb. bichromate of potash, 1-1/4 lb. Copper sulphate and 2-1/4 lb. tartar; then rinse well, and dye in a bath containing 2-1/2 lb. Logwood Extract (dry), 1-1/4 lb. Fustic Extract (dry), and 3 lb. Sumac. Enter the goods in a warm bath, work for half an hour, then raise to the boil and work for three-quarters of an hour; lift, and sadden by adding 6 oz. Copperas. After re-entering the goods, work to shade. _Olive_.--Boil two hours in a bath consisting of 1-1/2 lb. tin salt, 2-1/2 lb. bichromate of potash, 10 lb. alum and 2-1/2 lb. sulphuric acid. Then enter in a boiling dye-bath containing 1-1/2 lb. alum, 4 lb. fustic extract and 3-1/2 lb. indigo extract. _Fulling Fast Olive_.--For one hour upon a bath containing 50 lb. Fustic, 5 lb. Bluestone, 2 lb. Tartar, 4 lb. Sumac, 1 lb. Copperas; lift and wash. _Fast Bright Olive_.--Boil for one hour upon a bath of 50 lb. Fustic, 3 lb. Bluestone, 2 lb. tartar, 1 lb. copperas, 2 oz. indigo extract. _Yellow Olive_.--Prepare a bath containing 10 lb. Glauber's salt, 1-1/2 lb. Anthracene Yellow B N, 2 lb. extract of indigo, 3 oz. Orange E N Z, 4 lb. sulphuric acid. Enter yarn at 160° F., give three turns, raise the temperature slowly to the boil, turn to shade; lift, and wash. _Olive Green_.--Mordant with 2 lb. potash bichromate, 1-1/2 lb. sulphate of copper, 1/2 lb. sulphuric acid. Boil for an hour and a half. Dye in a bath with 8 lb. Fustic extract, 5 lb. Sumac, 5 lb. Logwood, at the boil for an hour and a half. _Olive Bronze_.--Make the dye-bath with 10 oz. Fast Yellow S, 5 lb. Indigo extract, 5 oz. Orange E N Z, 4 lb. sulphuric acid, 10 lb. Glauber's salt. Enter yarn at 140° F., work for a few minutes, then bring slowly to the boil and work to shade. _Emerald Green_.--Prepare the dye-bath with 1 lb. Acid Green B N, (p. 136) 2 oz. Naphthol Yellow S, 10 lb. Glauber's salt, 2 lb. sulphuric acid. Enter cold, then raise to the boil and work for a quarter of an hour; wash and dry. _Invisible Green_.--First mordant the wool in a bath containing 3 lb. bichromate of potash, 1-1/2 lb. copper sulphate, 1 lb. sulphuric acid. Work at the boil for one and a half hours, then dye in a fresh bath containing 2 lb. Milling Yellow O, 2 lb. Logwood extract, 20 lb. Glauber's salt. Work at the boil for one and a half hours, then lift, wash and dry. _Sea Green_.--Prepare a dye-bath with 5 lb. Glauber's salt, 2 lb. sulphuric acid, 2 lb. indigo extract, 1/2 per cent. Acid Green blue shade. Dye as usual. Cyprus Green B, and Cyprus Blue B, belong to a new group of dyes that owe their value in wool dyeing to the fact that the dyeings after being treated with copper sulphate become very fast to light and washing. Three per cent. of each gives very full shades of bluish green or dark blue. The dyeing is done with Glauber's salt and acetic acid when reddish shades are got; these in a bath of copper sulphate turn green or blue. BLUE SHADES ON WOOL. There are a very large number of blue artificial dyes of every class, but only a few natural ones, indigo and logwood, and with these every imaginable tint and shade of blue from the palest sky tints to the darkest navy blue or blue black can be produced. While some of the blue colouring matters possess no great powers of resistance to light, air, washing, etc., the great majority are remarkable for their fastness to those destructive agencies. There are but two natural dye-stuffs, indigo and logwood, from which blue tints can be dyed. With the former, a great variety of shades can be dyed of a satisfactory character as regards fastness; with the (p. 137) latter, only dark blues can be dyed, these are fairly fast to milling, but only moderately so to light. The artificial blues derived from coal tar are very numerous, and representatives of all classes, direct, basic, acid and mordant of dye-stuffs may be found among them. The direct blue dyes do not work very well on wool. They are apt to dye very red, and somewhat dull shades, which are, however, fairly fast to washing and light. The basic blue dyes are fairly numerous, and may be used to dye from pale sky to deep navy tints. They are apt to work somewhat unevenly on to wool, owing to their great affinity for the fibre. They give shades possessing some degree of resistance to light, but which are not very fast to washing and milling, although, in this respect, there are very great differences among them. The acid dyeing blues are fairly numerous, but they dye a great variety of tints, usually fairly fast to washing, milling and light. The mordant blues are pretty numerous and of great value for dyeing wool, as they give shades which are remarkable for their fastness to light, acids and milling, hence they are most extensively used, especially for dyeing fabrics that are subject to very hard wear. #Indigo Dyeing.#--It will be most convenient to begin the description of the methods of dyeing blues by showing how, and in what manner, indigo is applied in wool dyeing. The dyeing of indigo on wool is effected in two ways, either in the usual way with acid baths, as with acid scarlets, when the so-called indigo extract is used, or in vats, when indigo itself forms the dye-stuff. Indigo is, as all dyers know, or should know, a natural dye-stuff, prepared from the leaves and twigs of the indigo plant by a species of fermentation which produces the indigo in a soluble form from the indigo substance in the plant, followed by oxidation which results in the separation of the indigo from this solution. It comes into this country in the form of lumps, which have a dark (p. 138) blue to bronze blue colour. The dye-stuff is insoluble in water, cold alcohol, alkalies or weak acids. When heated with strong and fuming sulphuric acid it dissolves, forming a blue liquor from which the colouring matter may be obtained on addition of soda in the form of a paste, which is used in wool and silk dyeing under the name of indigo extract. But dissolving in sulphuric acid materially affects the properties of indigo as a dye-stuff, as will be seen later on. By the action of reducing agents the insoluble blue indigo is converted into a soluble white indigo. This body is rather unstable, and on exposure to the air it rapidly becomes oxidised and converted back again into the blue indigo. Upon this principle is based the application of indigo in dyeing by means of the vat. Various methods may be adopted to cause the indigo to become dissolved. These may be divided into two groups: (1) Fermentation vats, in which the action of reducing agents is brought about through the influences of the fermentation of organic bodies, such as woad, bran, treacle, etc; (2) Chemical vats in which the reducing effect is brought about by the reaction of various agents on one another. Of such vats the copperas and lime and the hydrosulphite vats are examples. The fermentation vats, when in good order, work well and give good results, but they are most difficult to prepare or set. The chemical vats are the easiest to work, and (especially the hydrosulphite vats) are coming to the fore, and are gradually driving out the fermentation vats. The actual method of dyeing with the indigo vat is the same with all methods of preparation. The material to be dyed is well wetted or wrung out in water. It is then dipped into the vat, handled a few minutes to ensure its thorough impregnation, then lifted out, the surplus liquor wrung out, and the material exposed to the air, (p. 139) when the indigo white on it soon absorbs oxygen and turns into blue indigo. With these few preliminary remarks the methods of setting the various indigo vats will now be described in detail. #Woad Indigo Vats.#--This is one of the most difficult of the various methods of setting vats. There are so many opportunities for it to go wrong, and to be able to set a woad vat successfully will go far to make a man a successful indigo dyer. No two woad vat dyers use exactly the same recipe in setting a woad vat, and each considers he has a secret art by means of which he ensures the successful working of this vat, and this he jealously guards. All these differences in the manner of setting the vat are brought about not by any radical differences in the materials used, but by some unnoticed differences in other surroundings; differences in the mean temperature of the water used, in the general conditions of the atmosphere of the indigo shed and in other similar circumstances, all of which have a material influence on the development of the vat, but which are, in the majority of cases, overlooked by the indigo dyer, the result being that a method of working which is successful in one place would not be so in another. The fermentation processes depend upon the reducing action brought about by certain organisms of the nature of the yeast plant which grow and develop in such vats. To ensure the proper growth and development of these organisms every condition must be perfect, correct temperature, proper proportions of food for them to live on, and a certain degree of alkalinity or acidity of the vat, and these points are most difficult to regulate as they will vary very much from time to time. A successful vat maker is one who closely observes his vats, and the way in which they are working, and who, as the result of such (p. 140) observations, is able to tell in what way his vats are deficient, so that he may know how to supply that deficiency. The following method of setting a woad vat may be adopted. It is calculated for 100 gallons of liquor. The vat is filled with hot water, and 80 lb. of woad are allowed to steep overnight in it, having first been well stirred into the water, so as to ensure that every part is wetted out. The next morning there is added 8 lb. madder, 12 lb. bran, 5 lb. quick-lime (previously slaked with water), and 2-1/2 lb. soda. These are thoroughly stirred together, then from 5 to 7-1/2 lb. indigo is stirred in. The indigo should have been previously ground into a fine paste with water. The temperature of the vat should now be maintained at from 115° to 125° F. for two to three days, at the end of which time it ought to be in a state of quiet working. Should it be found that the fermentation is going on too rapidly, a little lime may be thrown in, which will retard it. On the other hand, if it should not be going on with sufficient energy, this may be remedied by adding a little bran, or better, a little treacle. When in perfect condition the vat should have a slight smell of ammonia. If this is not noticed it indicates that the vat is deficient in alkalinity, and a little more lime should be added. Soda may be used in the place of lime, but it is so much more energetic in character that any additions of it have to be made with great care, or the vat will become too alkaline in character, and the fermentation will go on too rapidly, the ammoniacal odour is lost, and a peculiar putrid smell takes its place. As soon as this is noticed, lime ought to be added to retard the fermentation and to develop the ammoniacal smell. The colour of a good well-set vat is olive brown. When all the indigo is dissolved and the colour of the vat is a (p. 141) clear olive yellow to brown the vat is then ready for dyeing, and may be used for a long time, until, in fact, the deposit gets too large and the wool becomes dirtied. But it must not be continually worked, or it will give bad shades and loose colours. When in a bad condition it will usually turn of a dark brown colour, and give dull greenish shades. To remedy this there should be added some bran, treacle, and a little madder, as well as indigo, and the vat should be left for a day, at a temperature of 130° F., to get up to full strength again. Every night when in work indigo ought to be added to the vat in proportion to that consumed during the day, with bran and lime, the latter in not too great amount, just sufficient to keep it of the necessary alkalinity. #Hydrosulphite Vat.#--This is one of the best vats to use in dyeing with indigo on wool, or, indeed, on any textile fabric. It is easy to prepare and cleanly to work. While depending solely on chemical action for its preparation and use, it is freer from those peculiar defects to which organic vats, like the woad vats, are liable. There is a further advantage about this vat, it is not necessary to prepare each individual vat separately, but a strong mother liquor or concentrated indigo solution may be prepared, and this only requires letting down with water to produce a vat of any required strength. In the preparation of this vat, which was devised by Schutzenberger and Lalande, bisulphite of soda and zinc dust are used with either quick-lime or caustic soda. The bisulphite of soda is allowed to act on the zinc as will be detailed when an acid solution of sodium hydrosulphite NaHSO_{2}, more strictly hydrogen sodium hydrosulphite, is obtained. The acid solution of hydrosulphite has the property of rapidly reducing and dissolving indigo, and this solution may be used in dyeing. To prepare the hydrosulphite a vessel which is fitted (p. 142) with an agitator and can be closed is filled with zinc, either in the form of dust, foils, or granules. Then bisulphite of soda of 50° to 60° Tw. strength is poured over the zinc in sufficient quantity to cover it. All access of air should be avoided as much as possible, as it leads to oxidation. In the case of using zinc powder the action is often so rapid as to lead to heating, which also should be avoided. The operation takes from an hour to two hours, when the liquor may be drawn off. It must be used immediately to dissolve the indigo; or otherwise, as it is a very unstable body, it is liable to decompose and become oxidised, when it loses its solvent properties. If more hydrosulphite is required, fresh bisulphite may be poured over the zinc which is left unused in the vessel; if no more is wanted the zinc which is left should be well rinsed in water and the vessel filled with water, so as to prevent any oxidation of the zinc, and so keep it ready for use when required. The liquor thus made will usually have a specific gravity of 62° Tw. The zinc which is used up in the preparation of the liquor is replaced by fresh zinc from time to time. The liquor so obtained is, as stated above, rather unstable, and contains acid sodium hydrosulphite. By mixing with milk of lime, the acidity is neutralised, zinc oxide and calcium sulphite are thrown down, and a solution of neutral sodium hydrosulphite is obtained which is more stable and can be kept longer without decomposition. To prepare this, take 10 gallons of the acid liquor, as prepared in the manner described above, and mix it with 48 lb. of milk of lime, which is made from 2 lb. good quick-lime. Stir well together, allow all sediment to settle, or better, filter-press the mass. A liquor of 36° Tw. strength will usually be obtained. Do not let it stand too long before use, make it alkaline by adding a little lime. To make the mother or stock indigo, the following method of (p. 143) procedure may be adopted. Indigo, say 10 lb., is ground into as fine a paste as possible with 13 lb. milk of lime, of such a strength that 1 gallon shall contain 30 oz. quick-lime. To this is then added so much of either the acid or the neutral sodium hydrosulphite as can be made from 90 lb. of bisulphite of soda, the mixture being kept at 150° F., until a comparatively clear, greenish yellow solution is obtained, this will contain about 1 lb. of indigo per gallon. This mother liquor may be used in setting the vat as follows. The vat is filled with water which is heated to 120° F., about 200 gallons being used. To this is then added 1 gallon of either hydrosulphite or bisulphite of soda to destroy the free oxygen it contains, and prevent it from oxidising the indigo solution, which is next added. The quantity of the latter is solely regulated by the depth of shade it is desired to dye, and as soon as the requisite quantity has been added the dyeing may be proceeded with at once, and the first portion of goods put through will soon show the dyer whether too much or too little of the mother indigo has been added. Continued use and the consequent agitation of the vat thereby generated causes it to become oxidised, and the vat acquires a greenish colour, and does not give fast colours. When this is noticed the use of the vat is stopped; it is heated to about 160° F., and a little lime and hydrosulphite added, when all the oxidised indigo in the vat will speedily be reduced, and the vat put into a workable condition again. By use this vat tends to become alkaline, and consequently will spoil the wool, making it harsh and brittle. This is remedied by adding a little hydrochloric acid. #Holliday's Patent Indigo Vat.#--Messrs. Read Holliday & Sons have patented an improved method of making an indigo solution and the method of using it. They supply the indigo in the form of solution in two strengths, ordinary and concentrated. Both are used in the same way, only of the latter less, about one-fourth to one-third, is (p. 144) required than of the former. For those who would wish to buy their indigo ready prepared for use these are very convenient forms. The best way of working the vat for wool is the following: 40 gallons of water heated to about 50° C., add 1/4 lb. of a mixture of 1-1/4 gallons bisulphite of soda, 52° Tw., and 1 lb. zinc dust, and, say, 1/2 gallon to 2 gallons, of the patent indigo solution, according to the depth of shade required. The boiled out wool is worked below the surface of the liquor for about three minutes, then taken out, and the excess of liquor squeezed back into the vat, the whole operation is repeated until the shade is arrived at. After dyeing, rinse in an acid bath of 1° to 2° Tw. The advantages of this new vat are that brighter shades are obtained and the darker shades with fewer dips, while the goods are dyed cleaner and the shades are more quickly obtained, and, we think, somewhat faster than by the other process. There is also the advantage that no lime or other alkali is used with this new indigo vat. The wool should be boiled out before dipping, if the best results and even shades are desired. #Potash-Indigo Vat.#--This is also a fermentation vat, and is set in the following manner: 5 lb. of madder and 4 lb. of bran are mixed with 50 gallons of water and heated for from three to four hours, until a temperature of from 180° to 212° F. is attained. Then 15 lb. of carbonate of potash are added and the liquor is allowed to cool down to about 120° F. Next 10 lb., more or less according to shade required, of finely ground indigo is added, and the whole is left for from forty-eight to sixty hours to ferment, being stirred up at intervals of twelve hours. This vat ferments in much the same way as the woad vat, and presents the same general appearances. It is not so liable to get out of order as the woad vat, and in consequence is (p. 145) much more easily managed. It does not, however, give such bright shades as either of the vats previously described, but it dyes a little quicker, and deeper shades can be produced. It is the best vat to use where indigo dyeing is carried on at irregular intervals, also for dyeing dark shades of navy blue and for giving an indigo bottom for dark blues, browns and greens. Such shades stand milling and alkalies very well. #Soda-Indigo Vat.#--The soda-indigo vat is set in the following manner: 100 lb. bran is boiled with 200 gallons of water for three hours, then the liquor is allowed to cool from 100° to 120° F. Then 20 lb. of soda crystals, 5 lb. slaked lime, and 10 to 15 lb. ground indigo are added, the mixture being left for two or three days to ferment, and stirred up at intervals. Sometimes a little more soda or a little lime is added, as may be judged from the appearance of the vat, these appearances being practically the same as those met with in the woad vat, which have already been described in detail. The soda vat closely resembles the potash vat, but is cheaper to produce. It keeps its dyeing power longer, but is somewhat more liable to get out of order. It is like the potash vat, easier to manage than the woad vat, as with all the woad vats it is necessary after working them for a day to replenish them with a little indigo, soda, or potash, as the case may be, and a little bran. Cleaner vats are obtained if treacle be substituted for the bran, but the latter ferments better, and gives better results in working. #Urine-Indigo Vat.#--This vat has almost, if not quite, gone out of use, being a rather unpleasant vat to work with, with few advantages over other vats. One advantage it possesses over the woad and potash vats is that it is the best for working on a small scale, but the modern zinc reduction vats run it very close in this respect. The vat is (p. 146) made as follows: To 50 gallons of stale urine 4 lb. of common salt are added, and the mixture heated to from 120° F. to 140° F. Then 1 lb. madder and 1 lb. ground indigo are added, and the mass is well stirred. Then the mixture is allowed to stand until the indigo is completely reduced, when the vat is ready for dyeing. #Indigo-Indophenol Vat.#--Messrs. Durand, Huguenin & Co. have introduced the use of Indophenol along with indigo in wool dyeing. Indophenol can be reduced in the same way as indigo, and fibres dipped in this reduced product on exposure to air turn blue in the same way as if dipped in an indigo vat. By itself indophenol has not met with much favour from dyers for a variety of reasons, but it has been found that, mixed with indigo, it can be used in dyeing with some advantage on the score of cheapness. The newly mixed vat is made in the following manner:-- In a convenient vessel 26 gallons of water, 15 lb. zinc dust, ground into a paste with 6 gallons of water, and 7 gallons bisulphite of soda of 55° Tw. strong are mixed. Then 8 pints caustic soda lye of 72° Tw., and 16 pints liquor ammonia are added, and the whole mass is well stirred up; 22 lb. good indigo of about 70 per cent. indigotine and 7-1/4 lb. Indophenol are thoroughly ground into a paste with 7 gallons of water and 2 pints caustic soda lye of 72° Tw. The paste is added to the previous mixture, and, after being well stirred in, sufficient water is added to make the total volume of liquor up to 100 gallons. The mass is stirred up from time to time during a period of from thirty-six to forty-eight hours, by which time, as a rule, the indigo and Indophenol will have been completely reduced, and the vat have acquired a canary-yellow colour; if it has not, add a little more zinc dust and bisulphite of soda. It is ready for use when it has a good yellow colour. This forms what may be called a "mother," or stock vat, from which (p. 147) the dyeing vat is made in the following manner: Take a sufficient quantity of water to make the dyeing vat, add some hydrosulphite of soda (see below) to destroy any oxidising action the vat liquor may have, then add sufficient of the stock vat to give the required shade, this point is one which must be determined by experience. The vat is now quite ready for use, and the wool is entered and treated in the usual manner. After dyeing each lot of wool it is advisable to add some of the stock vat to replace the indigo abstracted by the goods. When a number of dyeings have been done, it is possible that the vat may become charged with oxidised indigo and lose its clean, yellow colour. It may be restored to its former conditions by adding some hydrosulphite of soda. Of course, after considerable use this, like all other indigo vats, becomes too highly charged with sediment, etc., to give excellent results, in which case the only thing that can be done is to throw the old vat away and start a new one. The hydrosulphite of soda referred to above is made in the following way: 4-1/2 lb. zinc dust are ground into a paste with 5-1/2 gallons of water and then mixed with 4 gallons bisulphite of soda at 55° Tw., stirring well so as to keep the temperature down. Then add 3 pints caustic soda lye of 72° Tw., and 3-1/2 pints liquor ammonia. Finally, add sufficient water to make 13 gallons. After standing for two or three days the preparation is ready for use. It should be alkaline in property; if not, add a little ammonia to make it so. This vat gives very good bright shades, from sky blue to dark navy, which are equally as fast as pure indigo shades. Sometimes woollen goods dyed with indigo rub badly. The causes of this defect vary from time to time, and in many instances are often obscure in their origin. All goods intended for indigo dyeing, and more especially when shades fast to rubbing are desired, should be (p. 148) thoroughly cleansed, and before passing into the indigo vat should be thoroughly freed from any soap which may have been used in the boiling out. Then, after dyeing, they ought to be well rinsed in water and passed through a sour made with sulphuric acid (2 lb. in 10 gallons), and then washed again. Vats highly charged with sedimentary matter, or with zinc or lime, are often the cause of loose shades. The remedy is obvious, _viz_., the discarding of such vats and the preparation of new ones, in fact old vats are perhaps more fruitful sources of loose shades than any other cause. Soft water suits indigo dyeing better than hard water, and is to be preferred. It is not advisable to attempt to get full or deep shades of indigo at one dip, for such would necessitate the use of strong baths. Dyeings produced in this way are liable to rub badly, because the indigo lies mostly on the surface, to which it is more or less mechanically attached. Light shades of indigo are fast to rubbing, and by repeated dippings in a light vat or a medium shade vat deep shades of fair fastness to rubbing can be got. As repeatedly stated, no indigo vat can be worked continuously with good results; the continual agitation induced by the passage of the yarns or cloths into the liquor brings the liquor into contact with the air, and oxidation sets in, resulting in the indigo being thrown out of the liquor in its original form. When this happens the vat loses its original clear yellow or yellowish-brown colour and becomes greenish, a sure sign that the vat is getting out of condition to give good results. The remedy has been pointed out in dealing with each kind of vat, and consists essentially in adding to the vat more of the active reducing agent and allowing the vat to rest a while. The dye-vats may be either round tubs or square wooden tanks; for yarn in hanks, when cloths or warps are being dyed, these may be fitted (p. 149) with winces and guide rollers so as to draw materials through the liquor. The hawking machine shown in figure 22 is also very good for indigo cloth dyeing, and is largely used for this purpose. [Illustration: Fig. 23.--Indigo Dye-vat.] Figure 23 also shows an excellent machine for indigo dyeing on cloth. In this the vat has a frame carrying guide rollers, round which the cloth passes, so that it travels several times through the vat liquor in its passage from one end of the vat to the other, the amount of liquor in the vat being so arranged that the cloth is entirely immersed the whole time. After going through the liquor the cloth passes between a pair of squeezing rollers, in order to have any surplus liquor taken out, then it traverses the space between sets of guide rollers arranged over the vat, during which time the indigo becomes oxidised and the blue develops, while finally it is (p. 150) plaited down on a table. The illustration clearly shows the working of the machine. #Dyeing Wool with Indigo Extract.#--Sulphonated indigo, prepared by dissolving indigo in sulphuric acid, is sold under the name of "indigo extract," or "indigo carmine," in two forms--paste (containing, perhaps, 25 to 30 per cent. actual colour) and powder. Both forms are freely soluble in water, although some makes are more so than others. This quality of solubility is dependent upon the proportion of sulphuric acid which may have been used in the preparation of the extract. When this is small, what is termed indigo monosulphonic acid only is formed, which is but slightly soluble in water, and gives red shades. If a larger proportion of acid be used, then the indigo disulphonic acid is formed, which is fairly easily soluble in water, and gives bluer shades than the former. As all forms of indigo extract are regular articles of commerce, details for their preparation will not be given here. It will suffice to say that indigo is heated with strong sulphuric acid until test samples show that the indigo has been completely dissolved, and it is then diluted with water and filtered. Sometimes it is sold in this condition under the term "chemic," but if this be used in dyeing wool it gives rather unsatisfactory results. When "sour extract" is required, the liquor filtered out is next treated with salt until all the colour has been precipitated out, when it is filtered off, drained, pressed and sold. Should "neutral" or "sweet" extract be required, then the acid liquor is neutralised with soda, and the product is salted out as before, drained and pressed to a suitable consistence. It is then sold as "indigo extract," or dried, at 150° F., to a powder, which is known as "indigo carmine". All forms of indigo extract are dyed on wool from baths of (p. 151) Glauber's salt and sulphuric acid, and therefore they can be classed with the acid-dyeing coal-tar colours. Indigo extract is notable for its level dyeing and penetrative properties, but it is not fast to light or milling. Messrs. Read Holliday & Sons have a powder form of indigo extract which will be found very useful and to give better shades than the usual run of paste extract, while it only takes about one-fifth the quantity to give a similar shade. Working at the boil should be avoided with indigo extract, as tending to make the shades greenish in tone; from 170° to 180° F. will usually be found hot enough to dye good shades. Indigo extract is not much used by itself in dyeing blues on wool, but it is extensively employed along with other dye-stuffs to produce an immense variety of shades--drabs, greens, fawns, greys, lilacs, etc., of which some examples will be given later on. _Indigo Blue_.--Prepare a bath with 10 lb. indigo extract, 5 lb. sulphuric acid, and 10 lb. Glauber's salt. Work just under the boil to shade. _Sky Blue_.--The dye-bath contains 1 lb. indigo extract, 2 lb. sulphuric acid, and 10 lb. Glauber's salt. Work at about 160° F. to shade. #Dyeing Wool Blue with Logwood.#--This method of dyeing blue on wool has lost much of its importance since the introduction of the artificial dyes, but it is still employed when a blue fast to milling is wanted. Logwood gives dark navy blue shades. The process is as follows: The wool is first mordanted by boiling for one and a half hours in a bath of 3 lb. bichromate of potash and 2-1/2 lb. of tartar. The operation must be so carried out that the non-oxidising green chrome mordant is developed on the fibre, and therefore the boiling must be thorough. In place of tartar, argols and oxalic acid are frequently used, while lactic acid or lignorosine might be employed. The dyeing is done (p. 152) in a bath of 20 to 25 lb. logwood, or 5 to 8 lb. logwood extract; the bath is started cold, heated slowly to the boil, and kept at that heat for one to one and a half hours. Between the mordanting and dyeing the wool should be well rinsed. DYEING BLUE WITH COAL-TAR DYES. The blue dyes derived from coal tar are very numerous, direct, basic, acid and mordant blues being known. The direct and basic dyes are very little used, but the acid and mordant dyes are extensively employed, as is indicated in the following recipes. #Dyeing with Direct Dyes.# _Pale Blue_.--Prepare a dye-bath with 1/2 lb. Sulphon Cyanine and 10 lb. Glauber's salt. Enter the goods, and work at the boil for one hour, then lift, wash and dry. _Black Blue_.--Prepare a dye-bath with 3 lb. Sulphon Cyanine, 5 lb. Glauber's salt, and 5 lb. acetate of ammonia; work at the boil for one hour. Sulphon cyanine works well with other dye-stuffs, and gives shades which are fast to milling. #Dyeing with Acid Dyes.# _Bright Blue_.--Prepare a bath with 2 lb. borax and 1 lb. Alkali Blue B. Enter the wool at about 170° F., then heat to the boil, and work for half an hour; then lift, rinse lightly, and pass into a weak sour bath, with sulphuric acid to raise to the colour. Soda may be used in place of borax, but the latter salt maintains the softness of the wool fibre better. By using various brands of Alkali Blue (3 R to 7 B), various shades of blue from a reddish with the 3 R to a pure blue with the 6 B and 7 B brands may be dyed. The Alkali Blues are fairly fast to light. _Dark Blue_.--Prepare a dye-bath with 2 lb. Serge Blue, 10 lb. Glauber's salt, and 2 lb. sulphuric acid, working at the boil (p. 153) for one hour. This is a very common way of dyeing blues on serges, cashmeres and worsted goods. In place of serge blue, what are known as Blackley blues, or Dewsbury blues, may be employed. These have a similar composition, but vary a little in the tint of blue they give. _Navy Blue_.--Prepare a dye-bath with 2 lb. Induline A, 10 lb. Glauber's salt, and 2 lb. sulphuric acid, working at the boil for one hour. The Indulines are very useful colouring matters for dyeing navy or dark blues on wool. They have the defect of being liable to give uneven shades. This may be remedied by omitting the acid when first making up the bath, entering the wool, working for half an hour to thoroughly impregnate the material with the dye-liquor, then adding the acid, and continuing the working for another half-hour. Or the wool may be treated to a weak chlorine bath before it is dyed, by first passing it through a weak hydrochloric acid bath and then through a bath of bleaching powder. By using acetic acid in place of sulphuric acid more even shades are obtained. _Blue_.--Prepare a dye-bath with 1 lb. Acid Blue 1 V, 9 oz. Acid Violet 1 V, 10 lb. Glauber's salt and 2 lb. sulphuric acid, working at the boil for one hour. _Blue Black_.--For this the dye-bath is made with 8 lb. Acid Blue 1 V, 10 lb. Glauber's salt, and 2 lb. sulphuric acid, working at the boil for one hour. _Deep Navy Blue_.--A very good shade is dyed with 5 lb. Acid Blue 1 V, 3 lb. Acid violet 1 V, 10 lb. Glauber's salt, and 2 lb. sulphuric acid, working at the boil for one hour. _Deep Navy_.--Prepare a dye-bath with 1 lb. Fast acid Magenta B, 3 lb. Wool Blue B X, 4-3/4 oz. Orange I I, 5 lb. sulphuric acid, and 10 lb. Glauber's salt, working at the boil for one hour. The Patent Blues work exceedingly well on wool, giving good bright shades of a fair degree of fastness. The following recipes will (p. 154) give some idea of the nature of the shades which may be obtained from them, while later on their use in combination with other dyes for the production of compound shades will be shown. _Bright Blue_.--Prepare a dye-bath with 2 lb. Patent Blue N, or Patent Blue superior, 10 lb. Glauber's salt, and 2 lb. sulphuric acid, working at the boil for one hour. _Bright Greenish Blue_.--Use 2 lb. Patent Blue V, 10 lb. Glauber's salt, and 2 lb. sulphuric acid. _Royal Blue_.--Use 2 lb. Patent Blue B, or 2 lb. Patent Blue J (No. 3), 10 lb. Glauber's salt, and 2 lb. sulphuric acid. Patent Blue J (No. 3) gives slightly more violet shades than Patent Blue N, but there is not much difference between them. _Saxony Blue_.--Use 2 lb. Patent Blue J (No. 00), 2 lb. sulphuric acid, and 10 lb. Glauber's salt. Patent Blue J (No. 00) dyes shades very closely resembling those dyed with indigo extract, and where the latter is used in the dyeing of compound shades the former might be substituted. _Brilliant Royal Blue_.--Prepare a bath with 1-1/2 lb. New Victoria Blue B, and 10 lb. Glauber's salt. Enter at about 100° F., then raise to the boil and work for one hour. This gives a very brilliant shade of blue of a violet tone. _Sky Blue_.--Prepare a dye-bath with 1-1/2 oz. New Victoria Blue B and 2 lb. Glauber's salt, working in the manner described in the last recipe. _Dark Blue_.--Prepare a dye-bath with 1-1/2 oz. Acid Violet 5 B, and 1-1/2 lb. Fast Green Bluish, 10 lb. Glauber's salt, and 2 lb. sulphuric acid, working at the boil to shade; then lift, wash and dry. _Deep Blue_.--Make a dye-bath with 4 lb. Chromotrop 6 B, 10 lb. Glauber's salt, and 4 lb. acetic acid. Work for one hour at the boil; then lift, add 2 lb. bichromate of potash and 3 lb. acetic acid, re-enter the goods and work for one hour longer; lift, wash and dry. The blues produced from the Chromotrops according to the last (p. 155) recipe are full, solid-looking shades, and have a great degree of fastness to milling and light. Some other examples showing the production of blue shades from the Chromotrops will be given later on. _Violet Blue_.--Prepare a dye-bath with 2 lb. Victoria Violet 8 B S, 10 lb. Glauber's salt, and 2 lb. sulphuric acid, working at the boil to shade; then lift, wash and dry. _Deep Blue_.--A fine deep blue is dyed on wool from a bath containing 6 lb. Victoria Violet 8 B S, 10 lb. Glauber's salt, and 2 lb. sulphuric acid, working at the boil to shade. _Deep Sky Blue_.--A fine shade is dyed in a bath containing 4 oz. Cyanole extra, 10 lb. Glauber's salt and 2 lb. acetic acid. _Electric Blue_.--Make the dye-bath with 4 oz. Cyanole extra, 1 oz. Acid Green extra, and 10 lb. bisulphate of soda. _Bright Blue_.--A very fine shade of blue can be dyed in a bath containing 3 lb. Cyanole extra and 10 lb. bisulphate of soda. _Dark Navy Blue_.--Prepare the dye-bath with 4 lb. Cyanole extra, 9 oz. Archil Substitute N, and 10 lb. bisulphate of soda. _Dark Navy_.--Prepare the dye-bath with 5 lb. Black Blue O, 1-3/4 oz. Formyl Violet S 4 B, 4 oz. Patent Blue V, 25 lb. Glauber's salt, and 4 lb. bisulphate of soda, adding 1 lb. sulphuric acid when the dyeing is about half done. The navy blues given in the last few recipes possess the merit of considerable resistance to light, air and milling. _Pale Blue_.--Make the dye-bath with 1/2 oz. Chromotrop 2 R, 4 oz. Cyanine B, 7-1/2 oz. Fast Acid Blue R, 1/2 oz. Azo Yellow, 10 lb. acetic acid, and 15 lb. Glauber's salt. _Peacock Blue_.--A fine shade is dyed with 14 oz. Cyanine B, 1-1/2 lb. Fast Acid Blue R, 2 oz. Azo Yellow, 10 lb. acetic acid, and 15 lb. Glauber's salt. _Dark Invisible Blue_.--Make the dye-bath with 2 lb. Victoria (p. 156) Black Blue, 10 lb. Glauber's salt, and 3 lb. sulphuric acid. _Bright Blue_.--A very fine shade of blue, not, however, fast to light, is dyed from a bath containing 1/2 lb. Victoria Blue B, and 10 lb. Glauber's salt. _Bright Electric Blue_.--Prepare a dye-bath with 3/4 lb. Glacier Blue, 10 lb. Glauber's salt and 3 lb. sulphuric acid, working at the boil. This gives a very bright green shade of blue. _Dark Peacock Blue_.--Make the dye-bath with 1 lb. Naphthol Blue Black, 10 lb. Glauber's salt, and 3 lb. sulphuric acid. Peri Wool Blues B & G dye wool in very fast dark blue shades from baths of Glauber's salt and acetic acid. They are dye-stuffs which form with copper blue colour lakes of some fastness. The copper is amalgamated with the dye-stuffs as put on the market. _Pale Navy Blue_.--Mordant, 4 lb. bichromate of potash and 1-1/2 lb. oxalic acid. Dye, 2-1/2 lb. Alizarine Bordeaux B. _Navy Blue_.--Mordant, 4 lb. bichromate of potash and 2 lb. oxalic acid. Dye, 7 lb. Alizarine Bordeaux G. _Bright Violet Blue_.--Mordant, 3 lb. fluoride of chrome and 2 lb. oxalic acid. Dye, 3/4 lb. Celestine Blue B. _Navy Blue_.--A reddish shade of navy blue is dyed by mordanting with 3 lb. fluoride of chrome and 2 lb. oxalic acid, and dyeing with 3 lb. Celestine Blue B and 3/4 lb. Diamond Black. The Alizarine Cyanines are excellent dye-stuffs for giving dark blue and navy blue shades on wool. They dye fairly easily, and uniform shades are readily obtained, while they possess some considerable penetrative power, so that they are well adapted for dyeing heavy piece goods. The following recipes show their use and indicate the character of the shades the various brands yield. It may be added (p. 157) that the shades are fast to light and milling. _Red Navy Blue_.--Mordant, 4 lb. bichromate of potash, 2 lb. tartar, and 1-1/2 oz. sulphuric acid. Dye, 6 lb. Alizarine Cyanine R R R double. By using a mordant of 4 lb. fluoride of chrome and 2 lb. oxalic acid the shade is made brighter and not so red in tone. _Dark Blue_.--A red shade of blue almost approaching a navy is obtained by mordanting with bichromate of potash, as in the last recipe, and dyeing with 12 lb. Alizarine Cyanine R R, or with 13 lb. Alizarine Cyanine R. The shade with the latter dye-stuff is scarcely so red as with the former. _Dark Blue_.--Mordant with 4 lb. fluoride of chrome and 2 lb. oxalic acid and dye with 13 lb. Alizarine Cyanine R. _Dark Blue_.--A somewhat brighter and less red shade than is obtained by working as in the last recipe is given by mordanting with 3 lb. bichromate of potash, 2 lb. tartar, and 2-1/2 oz. sulphuric acid, and then dyeing with 17 lb. Alizarine Cyanine G extra. _Dark Blue_.--Mordant with 3-1/2 lb. bichromate of potash, 2 lb. tartar, and 3 oz. sulphuric acid. Dye with 18 lb. Alizarine Cyanine G G. _Peacock Blue_.--Mordant with 4 lb. fluoride of chrome and 2 lb. oxalic acid. Dye with 18 lb. Alizarine Cyanine G G. The addition of from 2 lb. to 5 lb. acetate of ammonia in working with the Alizarine Cyanines is a considerable advantage, by causing the dye-stuff to penetrate the fibre better and to give more uniform shades. _Medium Blue_.--Mordant with 3 lb. bichromate of potash and 2 lb. oxalic acid. Dye with 5 lb. Brilliant Alizarine Blue G, and 2 lb. acetic acid. _Black Blue_.--Mordant as in the last. Dye with 20 lb. Brilliant Alizarine Blue G and 2 lb. acetic acid. _Dark Navy_.--Mordant as in the last recipe and dye with 5 lb. (p. 158) Alizarine Cyanine 3 R double, 5 lb. Alizarine Blue G W, 2 lb. Brilliant Alizarine Blue G, and 2 lb. acetic acid. _Medium Blue_.--Mordant as in the last. Dye with 5 lb. Alizarine Blue G W, 2-1/2 lb. Brilliant Alizarine Blue G, and 2 lb. acetic acid. _Lavender Blue_.--Mordant with 3 lb. bichromate of potash and 2-1/4 lb. tartar. Dye with 2 lb. Alizarine Blue A. _Navy_.--Mordant as in the last recipe, and dye with 20 lb. Alizarine Blue A. _Deep Sky Blue_.--Mordant with 3 lb. bichromate of potash and 1 lb. oxalic acid, then dye with 2-1/2 lb. Chrome Blue. _Bright Blue_.--A very fine bright shade is obtained by mordanting as in the last, and then dyeing with 10 lb. Chrome Blue. _Lilac Blue_.--Mordant with 2 lb. bichromate of potash and 1-1/2 lb. tartar. Dye with 4 lb. Alizarine Blue D N W. Alizarine Blue R gives somewhat bluer shades than the D N W brand. _Slate Blue_.--Mordant with 3 lb. bichromate of potash and 2-1/2 lb. tartar. Dye with 2-1/2 lb. Alizarine Blue D N W, 4 oz. Alizarine Brown, and 1-2/3 oz. Alizarine Yellow. _Peacock Blue_.--Mordant with 3 lb. bichromate of potash and 2-1/2 lb. tartar. Dye with 6 lb. Alizarine Blue D N W, 3 lb. Alizarine Yellow, and 1-1/2 lb. Patent Blue A, adding a little acetic acid to the dye-bath. _Paris Blue_.--Mordant as in the last recipe. Dye with 3 lb. Galleine, 1 lb. Alizarine Blue D N W, and 1 lb. Patent Blue A, adding a little acetic acid. _Grey Blue_.--Mordant as above and dye with 4-1/2 lb. Alizarine Blue D N W, and 1 lb. Alizarine Brown. _Blue_.--Mordant with 10 lb. alum, 3 lb. tartar, and 2 lb. oxalic acid. Dye with 15 lb. Anthracene Blue W G, 3 lb. acetate of lime, and 1 lb. tannic acid. _Red Navy_.--Mordant as in the last recipe and dye with 15 lb. (p. 159) Anthracene Blue B W, 3 lb. acetate of lime, and 3/4 lb. tannic acid. _Dark Blue_.--Mordant with 1 lb. bichromate of potash and 2 lb. tartar. Then dye with 20 lb. Anthracene Blue W B. Anthracene Blue W G gives slightly greener shades than the W B brand, while the W R blue gives redder shades. Grounding wool with various tints of indigo is a favourite method of producing many useful shades on wool. In general it is a good plan, as the bottom so given is a fast and permanent one, and is not in any way affected (so far as the stability of the colour is concerned) by the subsequent dyeing operations, care of course being taken that these are the usual acid or mordanting baths. The only drawback against bottoming with indigo is the increased cost of dyeing necessitated by the extra labour, and materials required to dye the bottom. As to the methods and materials required, they are just those usually employed in indigo dyeing, and these have been described. The hydrosulphite vat, or Messrs. Holliday's patent indigo, is, perhaps, the most convenient method to adopt. _Dark Slate_.--Give a medium indigo bottom, then mordant with 3 lb. fluoride of chrome and 1 lb. oxalic acid, and dye with 1-1/2 lb. Anthracene Brown W, 1/2 lb. Alizarine Bordeaux G, and 1 oz. Diamond Flavine. _Dark Navy_.--Give a medium indigo bottom in the vat, then mordant with 3 lb. fluoride of chrome and 1-1/2 lb. tartar, finally dyeing with 6-1/2 lb. Alizarine Cyanine G, and 1-1/2 lb. Alizarine Bordeaux G. _Dark Blue_.--Give a medium indigo bottom, then mordant with 6 lb. fluoride of chrome and 2 lb. oxalic acid, finally dyeing with 14 lb. Alizarine Cyanine Black. _Blue Black_.--Give a deep indigo bottom in the vat, then mordant with 3 lb. bichromate of potash and 2 lb. tartar, finally dyeing with (p. 160) 6 lb. Alizarine Cyanine Black and 1-1/2 lb. Alizarine Cyanine 3 R double. VIOLET SHADES ON WOOL. Violet shades can only be obtained from the coal-tar colours, and of these there are not many. The recipes which are given below will serve to show what dye-stuffs are available, and will give some idea of the tints they dye. #With Direct Dyes.# _Pale Violet_.--Prepare the dye-bath with 1/2 lb. Sulphon Cyanine, 1/4 lb. Geranine B, 5 lb. Glauber's salt, and 5 lb. acetate of ammonia, working at the boil for one hour. #With Basic Dyes.# _Violet_.--The dye-bath is made with 1 lb. Methyl Violet 3 B, and 10 lb. Glauber's salt. A fine pure shade of violet is obtained. Methyl Violet is made in many brands, distinguished as B, B B, 2 B, 4 B, etc. By using either one or the other of these, a variety of tints of violet, from a red shade with Methyl Violet R through violet (B) to a violet blue with Methyl Violet 7 B, can be dyed. #Puce.#--A very bright shade of puce is dyed by using Methyl Violet R, and 10 lb. Glauber's salt. #With Acid Dyes.# _Violet_.--Make the dye-bath with 2 lb. Acid Violet 4 B S, 10 lb. Glauber's salt, and 2 lb. sulphuric acid. This gives a pure violet shade. If Acid Violet 6 B S be used a bluer shade is obtained. _Reddish Puce_.--A very bright red tint of puce is obtained by using 2 lb. Acid Violet 4 R S, 10 lb. Glauber's salt, and 2 lb. sulphuric acid. _Bluish Violet_.--Make the dye-bath with 3 lb. Acid Violet 5 B, 10 lb. Glauber's salt, and 2 lb. sulphuric acid, working at the boil for one hour. _Lavender_.--Use 4 oz. Acid Violet 5 B, 1 oz. Azo Fuchsine G, 1/16 oz. Fast Green bluish, 10 lb. Glauber's salt and 2 lb. sulphuric acid. _Deep Violet_.--A fine deep shade is obtained by using 2-3/4 lb. Chromotrop 6 R, 2-1/2 lb. Cyanine B, 10 lb. Glauber's salt, and (p. 161) 2 lb. sulphuric acid, working at the boil for one hour. _Mauve_.--Use 2 lb. Acid Mauve B, 10 lb. Glauber's salt, and 2 lb. sulphuric acid. _Bright Violet_.--Use 2 lb. Formyl Violet S 4 B, 10 lb. Glauber's salt, and 2 lb. sulphuric acid. _Bright Violet_.--Use 2 lb. Acid Violet 6 B N, 10 lb. Glauber's salt, and 2 lb. sulphuric acid. _Violet_.--Use 2 lb. Acid Violet N, 2 lb. sulphuric acid, and 10 lb. Glauber's salt. #With Mordant Dyes.# _Violet_.--Mordant the wool with 3 lb. bichromate of potash and 2 lb. tartar, and dye with 10 lb. Chrome Violet. _Dark Violet_.--Mordant as in the last recipe. Then dye with 3 lb. Chrome Bordeaux 6 B double and 2 lb. Brilliant Alizarine blue G. BROWN SHADES ON WOOL. Brown is a very important colour, of which there is an infinite variety of shades and it can be dyed in a great variety of ways and from a variety of dye-stuffs, as will be seen on looking through the recipes which follow, although these do not by any means exhaust the methods by which browns may be dyed on woollen goods, but they may be taken as representative and will serve to show by what combinations of dyes various tints of browns may be obtained. #With Direct Dyes.# _Brown_.--Make the dye-bath with 1 lb. Nyanza Black B, 2 lb. Congo Brown R, and 20 lb. Glauber's salt, working at the boil for one hour; then lift, wash and dry. #With Acid Dyes.# _Yellow Brown_.--Make the dye-bath with 1 lb. Azo Carmine, 1 lb. Fast Yellow, 1 lb. Indigo Carmine D, 10 lb. Glauber's salt, and 2 lb. sulphuric acid. A good shade is thus obtained. _Olive Brown_.--Use 3/4 lb. Azo Acid Violet 4 R, 2 lb. Fast (p. 162) Yellow, 3 oz. Fast Green bluish, 10 lb. Glauber's salt, and 2 lb. sulphuric acid, working at the boil for one hour; then lift, wash and dry. _Dark Chestnut_.--Dye in a bath containing 6-1/2 oz. Patent Blue V, 3-1/4 oz. Acid Violet V, 1 lb. Azo Yellow, 2 lb. Orange No. 2, 10 lb. Glauber's salt, and 2 lb. sulphuric acid, working at the boil for one hour; then lift, wash and dry. _Mouse_.--Make the dye-bath with 4 oz. Patent Blue V, 1-2/3 oz. Acid Violet N, 13 oz. Orange G, 10 lb. Glauber's salt, and 2 lb. sulphuric acid. _Deep Seal_.--Dye in a bath containing 1 lb. Orange G G, 1/2 lb. Patent Blue J 3, 1/2 lb. Azo Yellow, 3-1/4 oz. Acid Violet N, 10 lb. Glauber's salt, and 2 lb. sulphuric acid. _Deep Brown_.--Make the dye-bath with 1-3/4 lb. Chromotrop 2 R, 1-1/4 lb. Victoria Yellow, 4 lb. Keton Blue G, 2-1/2 oz. Acid Violet 5 B E, 25 lb. Glauber's salt, and 4 lb. sulphuric acid, working at the boil for one hour. _Walnut_.--A fine shade can be dyed with 1-3/4 lb. Azo Acid Magenta G, 14-1/2 oz. Patent Blue V, 3/4 lb. Victoria Yellow, 15 lb. Glauber's salt and 2 lb. sulphuric acid. _Olive Brown_.--Make a dye-bath with 2 lb. sulphuric acid, 10 lb. Glauber's salt, 1 lb. Azo Fuchsine G, 1/2 lb. Fast Yellow, and 1/2 lb. Fast Green extra bluish. _Dark Olive Brown_.--A very fine shade can be dyed with 1 lb. Fast Acid Violet 10 B, 1-1/2 lb. Orange 11, 1/2 lb. Fast Green bluish, 7 oz. Fast Yellow, 20 lb. Glauber's salt, and 3 lb. sulphuric acid. _Walnut_.--Use 1 lb. Cyanole, 1 lb. Orange extra, 1/2 lb. Archil Substitute N, 10 lb. Glauber's salt and 2 lb. sulphuric acid, working at the boil for one hour. _Dark Seal_.--Use 1 lb. Cyanole, 1 lb. Orange extra, 10 lb. Glauber's salt and 2 lb. sulphuric acid. _Golden Brown_.--A fine shade is dyed with 1-1/4 lb. Victoria (p. 163) Yellow, 9-1/2 oz. Chromotrop 2 R, 3-1/2 oz. Patent Blue V, 10 lb. Glauber's salt and 2 lb. sulphuric acid. #With Mordant Dyes.# _Golden Brown_.--Make the dye-bath with 1 lb. Diamine Fast Red F, 1-1/2 lb. Anthracene Yellow C, and 5 lb. acetate of ammonia. Work for half an hour; then add 5 lb. bisulphate of soda and work for half an hour longer, then add 3 lb. fluoride of chrome, and work for half an hour at the boil. _Bright Golden Brown_.--Use 3/4 lb. Diamine Fast Red F, 1-1/2 lb. Anthracene Yellow C, 5 lb. bisulphate of soda, as indicated in the last recipe. The shades so obtained are very fine, and have the merit of being fast to washing and light. _Chestnut_.--Give a medium indigo bottom in the vat, then dye in a bath containing 1-3/4 lb. Anthracene Yellow C, 1 lb. Diamine Fast Red F, and 5 lb. bisulphate of soda. Work again for half an hour, then add 3 lb. fluoride of chrome, and work again for another half hour; lift, wash and dry. _Dark Brown_.--Use a dye-bath containing 1-1/4 lb. Diamine Fast Red F, 3/4 lb. Anthracene Yellow C, 1-1/2 lb. Anthracite Black B, and 5 lb. acetate of ammonia. After half an hour's boiling, add 5 lb. bisulphate of soda, work half an hour longer, add 3 lb. fluoride of chrome, and work together another half hour; then lift, wash and dry. _Brown_.--A very fine shade can be dyed in the following way: First give a medium indigo bottom in the vat, then mordant in a bath containing 3 lb. bichromate of potash and 2-1/2 lb. tartar, and finally dye in a bath made from 1-1/2 lb. Alizarine Orange R, 4 lb. Diamond Flavine, and 2 lb. acetic acid. _Dark Seal_.--Give a medium indigo bottom in the vat, and Mordant with 3 lb. bichromate of potash and 2-1/2 lb. tartar, and finally dye in a bath containing 3-1/2 lb. Alizarine Orange R, 1 lb. Anthracene Brown R, 2 lb. Diamond Flavine, and 2 lb. acetic acid. _Brown_.--A full shade is dyed by first mordanting with 3 lb. (p. 164) bichromate of potash and 2 lb. tartar, and then dyeing with 10 lb. Anthracene Brown W, and 1 lb. Mordant Yellow. _Buff_.--Mordant as in the last, and dye with 5 lb. Anthracene Brown W, and 1/4 lb. Mordant Yellow O. _Nut_.--Mordant with 3 lb. bichromate of potash and 1 lb. oxalic acid, and dye with 20 lb. Diamond Brown. _Pale Old Gold Brown_.--Mordant as in the last, and dye with 5 lb. Diamond Brown. _Dark Violet Brown_.--Mordant as in the last recipes, and dye with 30 lb. Chrome Brown R. _Bright Chestnut_.--Mordant with 3 lb. bichromate of potash and 1 lb. sulphuric acid, and dye with 30 lb. Gambine R. _Pale Chestnut_.--Mordant as in the last recipes, and dye with 20 lb. Gambine Y. _Olive Brown_.--Mordant as in the last recipes, and dye with 10 lb. Gambine B. The browns dyed with Gambine have the merit of being fast to milling and light. _Dark Brown_.--Mordant with 3 lb. bichromate of potash and 2-1/2 lb. tartar; then dye with 15 lb. Alizarine Brown. _Bright Buff_.--Mordant as in the last recipe; then dye with 4-3/4 lb. Alizarine Brown, 4 lb. Alizarine Yellow, 1-3/4 oz. Alizarine Blue D N W, and 2 lb. acetic acid. _Dark Violet Brown_.--Mordant with 3 lb. bichromate of potash and 2-1/2 lb. tartar. Then dye with 18 lb. Alizarine Brown, 6 lb. Alizarine Orange H, and 2 lb. acetic acid. _Dark Walnut_.--Mordant with 3 lb. bichromate of potash and 1 lb. sulphuric acid; then dye with 8 lb. Alizarine Brown, 2 lb. Alizarine Red 3 W S, and 2 lb. Alizarine Yellow G G W. MODE COLOURS ON WOOL. Under the general designation of "mode colours" are included a great variety of tints or shades unusually described more specifically (p. 165) as drabs, buffs, greys, fawns, slates, etc. It is impossible here to do more than give a few recipes for their production. #With Direct Dyes.# _Drab_.--Make a dye-bath with 3 oz. Nyanza Black B, 1-1/2 oz. Chrysamine G, 2 oz. Congo orange R, and 20 lb. Glauber's salt, working at the boil for one hour; then lift, wash and dry. #With Acid Dyes.# _Bright Buff_.--Dye in a bath containing 3/4 oz. each Cyanole, Orange extra, and Indian Yellow R, 10 lb. Glauber's salt, and 2 lb. sulphuric acid. _Slate_.--Use a dye-bath containing 3 oz. Cyanole, 1/4 oz. Archil Substitute N, 1/2 oz. Orange extra, 10 lb. Glauber's salt, and 2 lb. sulphuric acid. _Silver Grey_.--Use 1-1/4 oz. Orange extra, 3/4 oz. Archil Substitute N, 10 lb. Glauber's salt and 2 lb. sulphuric acid. _Pale Drab_.--Make the dye-bath with 1/2 oz. Cyanine B, 3/4 oz. Azo Yellow, 1/4 oz. Chromotrop 2 R, 10 lb. Glauber's salt and 2 lb. sulphuric acid. _Grey_.--Make the dye-bath with 1 oz. Chromotrop 2 R, 1-1/4 oz. Cyanine B, 2-1/2 oz. Fast Acid Blue R, 2 oz. Azo Yellow, 10 lb. Glauber's salt and 5 lb. acetic acid. _Bright Fawn_.--The dye-bath is made with 2 oz. Chromotrop 2 R, 8 oz. Orange G, 2-1/4 oz. Fast Acid Blue R, 1-1/4 oz. Cyanine B, 10 lb. Glauber's salt and 5 lb. acetic acid. _Dark Buff_.--Use 2 oz. Cyanine B, 5 oz. Azo Yellow, 2-1/2 oz. Chromotrop 2 R, 10 lb. Glauber's salt and 2 lb. sulphuric acid. _Lilac Grey_.--Use 3 oz. each Fast Acid Violet 10 B, Fast Green bluish, and Fast Yellow, 10 lb. Glauber's salt and 2 lb. sulphuric acid. _Pale Fawn Drab_.--Use 1 oz. Patent Blue V, 1 oz. Rhodamine, 1-3/4 oz. Orange G, 10 lb. Glauber's salt and 2 lb. sulphuric acid. _Dark Grey_.--Use 1 lb. Wool Grey R, 10 lb. Glauber's salt and (p. 166) 2 lb. sulphuric acid. _Stone_.--Use 1 oz. Patent Blue J B, 1-3/4 oz. Orange G, 10 lb. Glauber's salt and 2 lb. sulphuric acid. _Pale Fawn Brown_.--Use 4 oz. Fast Acid Violet R, 2 oz. Patent Blue J O O, 3 oz. Orange G, 10 lb. Glauber's salt and 3 lb. sulphuric acid. _Drab_.--Use 3 oz. Azo Carmine, 1-1/2 oz. Fast Yellow, 1-1/4 oz. Indigo Carmine D, 10 lb. Glauber's salt and 2 lb. sulphuric acid. _Lilac_.--Use 1/2 lb. Azo carmine, 1/2 lb. Indigo Carmine D, 1-1/2 oz. Fast Yellow, 10 lb. Glauber's salt and 2 lb. sulphuric acid. #With Mordant Dyes.# _Pale Drab_.--Mordant with 2 lb. bichromate of potash and 1-1/2 lb. tartar. Dye with 1 lb. Alizarine Brown paste. _Violet Grey_.--Mordant as in the last recipe, and dye with 1 lb. Alizarine Grey B. _Pale Fawn_.--Mordant with 3 lb. bichromate of potash and 2-1/2 lb. tartar, and dye with 4-1/2 lb. Alizarine Yellow, 13 oz. Alizarine Brown, 11-1/2 oz. Alizarine Orange N, and 2 lb. acetic acid. _Pale Stone_.--Mordant with 2 lb. bichromate of potash and 1-1/2 lb. tartar. Dye with 13 oz. Alizarine Yellow and 1-1/4 lb. Alizarine Brown. _Dark Slate_.--Mordant with 3 lb. bichromate of potash and 2 lb. tartar. Dye with 2-1/2 lb. Alizarine Blue D N W, and 10 oz. Alizarine Yellow. _Lavender Grey_.--Mordant with 2 lb. bichromate of potash and 1-1/2 lb. tartar. Dye with 13 oz. Alizarine Blue D N W, and 2 oz. Galleine. _Drab_.--Mordant as in the last recipe; then dye with 4 oz. Alizarine Blue, 1-1/2 lb. Alizarine Yellow and 14 oz. Alizarine Brown. _Drab_.--Mordant with 3 lb. bichromate of potash and 1 lb. (p. 167) sulphuric acid, and dye with 1 lb. Gambine R. _Dark Grey_.--Give a light indigo bottom in the vat, and then dye in a bath containing 3/4 oz. Diamine Fast Red F, 3/4 oz. Anthracene Yellow C, and 5 lb. acetate of ammonia. Work at the boil for half an hour, then add 5 lb. bisulphate of soda, work half an hour longer, then add 1 lb. fluoride of chrome, and work for another half hour at the boil; then lift, wash and dry. CHAPTER V. (p. 168) DYEING UNION (MIXED COTTON AND WOOL) FABRICS. There is now produced a great variety of textile fabrics of every conceivable texture by combining the two fibres, cotton and wool, in a number of ways. The variety of these fabrics has of late years considerably increased, which increase may be largely ascribed to the introduction of the direct dyeing colouring matters--the Diamine dyes, the Benzo dyes, the Congo and the Zambesi dyes; for in the dyeing of wool-cotton fabrics they have made a revolution. The dyer of union fabrics, that is fabrics composed of wool and cotton, was formerly put to great straits to obtain uniform shades on the fabrics supplied to him owing to the difference in the affinity of the fibres for the dye-stuffs then known. Now the direct dyes afford him a means of easily dyeing a piece of cotton-wool cloth in any colour of a uniform shade, while the production of two-coloured effects is much more under his control, and has led to the increased production of figured dress fabrics with the ground in one fibre (wool) and colour, and the design in another fibre (cotton) and colour. The number of direct dyes issued by the various colour manufacturers is so great that it would take a fairly considerable space to discuss them all. To obtain good results it is needful that the dyer of union fabrics should be a man of keen observation and have a thorough knowledge of the dyes he is using, for each dye makes a rule to itself as regards its power of dyeing wool and cotton; some go better on to the (p. 169) cotton than on to the wool, and _vice versa_. Some dye wool best at the boil, others equally well below that heat; some go on the cotton at a moderate temperature, others require the dye-bath to be boiling; some will go to the cotton only and appear to ignore the wool. The presence or absence in the dye-bath of such bodies as carbonate of soda, Glauber's salt, etc., has a material influence on the degree of the affinity of the dye-stuff for the two fibres, as will perhaps be noted hereafter. Again, while some of the dyes produce equal colours on both fibres, there are others where the tone is different. With all these peculiarities of the Diamine and other direct dyes the union dyer must make himself familiar. These dyes are used in neutral baths, that is, along with the dye-stuff. It is often convenient to use along with the direct dyes some azo or acid dyes which have the property of dyeing the wool from neutral baths; many examples of such will be found in the practical recipes given below. The dyes now under consideration may be conveniently classed into five groups. (1) _Those dyes which dye the cotton and wool from the same bath to the same shade, or nearly so._--Among such are Thioflavine S, Diamine Fast Yellow B, Diamine Orange B, Diamine Rose B D, Diamine Reds 4 B, 5 B, 6 B and 10 B, Diamine Fast Red F, Diamine Bordeaux B, Diamine Brown N, Diamine Brown 3 G, B and G W, Diamine Blue R W, B X, Diamine Blue G, Diamine Greens G and B, Diamine Black H W, Diamine Dark Blue B, Union Black B and S, Oxydiamine Blacks B, M, D and A, Diamine Catechine G, Union Blue B B, Oxyphenine, Chloramine Yellow, Thioflavine S, Alkali Yellow R, Chromine G, Titan Scarlet S, Mimosa, Primuline, Auroline, Congo Corinth B, Thiazol Yellow, Columbia Yellow, Oxydiamine Yellow G G, Oxydiamine Oranges G and R, Diamine (p. 170) Orange O, Oxydiamine Red S. (2) _Dyes which dye the cotton a deeper shade than the wool._--The following belong to this group. Diamine Fast Yellow A, Diamine Orange G and D, Diamine Catechine G, Diamine Catechine B, Diamine sky Blue, Diamine Blues 2 B, Diamine Blue 3 B, Diamine Blue B G, Diamine Brilliant Blue G, Diamine New Blue R, Diamine Steel Blue L, Diamine Black R O, Diamine Black B O, Diamine Black B H, and Oxydiamine Black S O O O, Diamine Nitrazol Brown G, Diamine Catechine B, Diamine Sky Blue F F, Diamine Dark Blue B, Diamine Bordeaux B, Diamine Violet N, Oxydiamine Violet B, Columbia Black B and F B, Zambesi Black B, Congo Brown G, Direct Yellow G, Direct Orange R, Clayton Yellow, Cotton Yellow, Orange T A, Benzopurpurine B, Brilliant Congo R, Chicago Blues B, 4 B and 6 B. (3) _Dyes which dye wool a deeper shade than the cotton._--The dyes in this group are not numerous. They are Diamine Gold, Diamine Scarlet B, Diamine Scarlet 3 B, Diamine Bordeaux S, Diamine Blue R W, and Diamine Green G, Diamine Red N O and B, Chicago Blue G and R R W, Brilliant Purpurine R, Diamine Scarlet B, Deltapurpurine 5 B, Chrysamine, Titan Blue, Titan Pink, Congo Oranges G and R, Erie Blue 2 G, Congo R, Brilliant Congo R, Erika B N, Benzopurpurine 4 B and 10 B, Chrysophenine, Titan Yellow, Titan Brown Y, R and O, Congo Brown G, Sulphon Azurine B, Zambesi Black D. (4) _Dyes which produce different shades on the two fibres._--Diamine Brown G and Diamine Blue 3 R, Diamine Brown V, Diamine Brown S, Diamine Nitrazol Brown B, Diamine Blue B X and 3 R, Diamine Blue Black E, Benzo Blue Black G, Benzopurpurine 10 B, Benzo Azurine R G and 3 G, Columbia Red S B, Brilliant Azurine 5 G, Titan Marine (p. 171) Blue, Congo Corinths G and B, Azo Blue, Hessian Violet, Titan Blue, Azo Mauve, Congo Brown, Diamine Bronze G, Zambesi Browns G and 2 G, Zambesi Black F. (5) _Azo acid dyes which dye wool from neutral baths, and are therefore suitable for shading up the wool to the cotton in union fabric dyeing._--Among the dyes thus available may be enumerated Naphthol Blue G and E, Naphthol Blue Black, Formyl Violet 10 B, Lanacyl Blue B B, Lanacyl Blue R, Alkaline Blue, Formyl Violet S 4 B and 6 B, Rocceleine, Azo Red A, Croceine A Z, Brilliant Scarlet, Orange extra, Orange E N Z, Indian Yellow G, Indian Yellow R, Tropæoline O O, Naphthylamine Black 4 B, and Naphthol Blue Black, Brilliant Scarlet G, Lanacyl Violet B, Brilliant Milling Green B, Thiocarmine R, Formyl Blue B, Naphthylamine Blacks D, 4 B and 6 B, Azo Acid Yellow, Curcumine Extra, Mandarine G, Ponceau 3 R B, Acid Violet 6 B, Guinea Violet 4 B, Guinea Green B, Wool Black 6 B. Regarding the best methods of dyeing, that in neutral baths yields the most satisfactory results in practical working. It is done in a boiling hot or in a slightly boiling bath with the addition of 6-1/4 oz. crystallised Glauber's salt per gallon water for the first bath, and when the baths are kept standing 20 per cent. crystallised Glauber's salt reckoned upon the weight of the goods for each succeeding lot. In dyeing unions, the dye-baths must be as concentrated as possible and must not contain more than from 25 to 30 as much water as the goods weigh. In this respect it serve as a guide that concentrated baths are best used dyeing dark shades while light shades can be dyed in more dilute baths. The most important factor for producing uniform dyeings is the appropriate regulation of the temperature of the dye-bath. Concerning this the dyer must bear in mind that the direct colours possess a greater affinity for cotton if dyed below the boiling-point, and only go on the wool when the bath is boiling, (p. 172) especially so the longer and more intensely the goods are boiled. The following method of dyeing is perhaps the best one. Charge the dye-bath with the requisite dye-stuff and Glauber's salt, boil up, shut off the steam, enter the goods and let run for half an hour, without steam, then sample. If the shade of both cotton and wool is too light, add some more of the dye-stuffs used for both fibres, boil up once more, and boil for a quarter to half an hour. If the wool only is too light, or its shade different from that of the cotton, add some more of the dye-stuff used for shading the wool and bring them again to the boil. If, however, the cotton turns out too light or does not correspond in shade to the wool, add some more of the dye-stuffs used for dyeing the cotton, without, however, raising the temperature. Prolonged boiling is necessary only very rarely, and generally only if the goods to be dyed are difficult to penetrate or contain qualities of wool which only with difficulty take up the dye-stuff. In such cases, in making up the bath, dye-stuffs are to be selected some of which go only on the wool and others which go only on the cotton (those belonging to the second group). The goods can then be boiled for some time, and perfect penetration and level shades will result. If the wool takes up the dye-stuff easily (as is frequently the case with goods manufactured from shoddy) and are therefore dyed too dark a shade, then dye-stuffs have to be used which principally dye the cotton, and a too high temperature is to be avoided. In such cases it is advisable to diminish the affinity of the wool by the addition of one-fifth of the original quantity of Glauber's salt (about 3/8 oz. per gallon of water), and from three-quarters to four-fifths of the dye-stuff used for the first lot. Care has to be taken that not much of the dye-liquor is lost when taking out the dyed goods, otherwise the quantities of Glauber's salt and dye-stuff will have to be increased proportionately. Wooden (p. 173) vats such as are generally used for piece dyeing have proved the most suitable, they are heated with direct or still better with indirect steam. The method which has proved most advantageous is to let the steam run into a space separated from the vat by a perforated wall into which space the required dye-stuffs and salt are placed. The mode of working is influenced by the character of the goods, and the following notes will be found useful by the union dyer. Very little difficulty will be met with in dyeing such light fabrics as Italians, cashmeres, serges and similar thin textiles lightly woven from cotton warp and woollen weft. When deep shades (blacks, dark blues, browns and greens) are being dyed it is not advisable to make up the dye-bath with the whole of the dyes at once. It is much better to add these in quantities of about one-fourth at a time at intervals during the dyeing of the piece. It is found that the affinity of the wool for the dyes at the boil is so much greater than is that of the cotton that it would, if the whole of the dye were used, take up too much of the colour and then would come up too deep in shade. Never give a strong boil with such fabrics, but keep the bath just under the boil which results in the wool dyeing much more nearly like to cotton. #On Union Flannels.#--In this class of goods it is important that the soft open feel of the goods be retained as much as possible, and for this purpose no class of dyes offers so many advantages as the direct colours. Only one bath being required, there is not the same amount of manipulation needed in the dyeing operation, hence there is less risk that the soft feel and woolly structure will be affected. As no mordants are needed there is nothing to impart a harsh feel to the fabrics. #On Dress Goods, Suitings and Coatings.#--A large quantity of fabrics for gentlemen's suits, coats and cloths in general are now made (p. 174) from wool and cotton. Formerly the dyeing of these offered many difficulties before the application of the direct dyes was properly understood. Now, however the ease with which such dyes may be applied has given considerable impetus to this class of goods, and the trade has grown by leaps and bounds during recent years, and has been one cause of the great cheapening of clothes which has occurred in the same period. The dyeing of the goods with the direct colours offers very little difficulty, and only requires that a little attention be paid, particularly to goods in which the cotton either appears on the surface forming a design, or is spun or twisted together with the wool. A good deal of shoddy is used in making the cheaper class of these goods, and it is quite natural that such "artificial wool" behaves differently from pure wool, not only with regard to its shade resulting from mixing and working together differently dyed waste wools, but also on account of its possessing a greater affinity for all kinds of dye-stuff than raw wool; this in consequence of the carbonisation and washing processes it has undergone, and also of the mordants which the material may retain from previous processes. Therefore (and especially in dyeing light shades on goods manufactured of shoddy) only a small quantity of soda or borax is to be added to the dye-bath and severe boiling is to be avoided. Wherever it is possible goods which are to be dyed in light shades should be made from the palest materials, and the dark qualities only used for goods which are to be dyed in dark shades. This rule can, of course, not always be adhered to. Quite often a light and bright shade is to be dyed on comparatively dark material. This cannot be achieved by simply dyeing it, the goods must be stripped or bleached before dyeing. For this purpose either energetically reacting, oxidising reducing agents are applied. Of the former, bichromate of potassium is principally used. Boil the (p. 175) goods for half to three-quarters of an hour with 3 to 5 per cent. bichromate of potassium, 2 to 4 per cent. oxalic acid, and 3 to 5 per cent. sulphuric acid, wash in a fresh warm bath charged with soda in order to entirely neutralise the acid which has remained in the goods, or else the wool would be dyed too deep a shade. In some cases hydrosulphite has proved a useful reducing agent; it can be easily prepared from ordinary bisulphite of soda in the following manner. Add 10 oz. ammonia (0·9 specific gravity) to a gallon of bisulphite of soda, 32° Tw.; then add slowly under a brisk stirring 10 oz. zinc-dust, and let the entire mixture settle well, using only the clear solution. Treat the goods from fifteen to twenty minutes in a bath of 140° F., to which first add at the boil 3/4 oz. acetic acid, 10° Tw., per gallon water, and then 4 to 6 gallons clear hydrosulphite solution per 100 gallons liquor. Then rinse very well and dye in the usual manner; avoiding, however, too high a temperature. As on this class of goods dark shades are mostly dyed, the goods need only very rarely be stripped. _Bright Yellow_.--Use 2 lb. Thioflavine S in a bath which contains 4 lb. Glauber's salt per 10 gallons of dye-liquor. _Good Yellow_.--A very fine deep shade is dyed with 2-1/2 lb. Diamine Gold, and 24 lb. Diamine Fast Yellow A in the same way as the last. Here advantage is taken of the fact that while the Diamine Gold dyes the wool better than the cotton the Diamine Yellow dyes the cotton the deepest shade, and between the two a uniform shade of yellow is got. _Pale Gold Yellow_.--Use a dye-liquor containing 4 lb. Glauber's salt in every 10 gallons, 2-1/2 lb. Diamine Fast Yellow A, 2 oz. Indian Yellow G, and 3-1/2 oz. Indian Yellow R. In this recipe we use in the two last dyes purely wool yellows, which dye the wool the same tint as the Fast Yellow A dyes the cotton. _Bright Yellow_.--Use in the same way as the last 2-1/2 lb Diamine (p. 176) Fast Yellow B and 3 oz. Indian Yellow G. _Gold Orange_.--Use as above 2 lb. Diamine orange G, 3-1/2 oz. Indian Yellow R, and 1-1/2 oz. Orange E N Z. _Deep Orange_.--Use 2-1/2 lb. Diamine Orange D C, 6-1/2 oz. Orange E N Z, and 3-1/4 oz. Indian Yellow R. _Black_.--Use 4-1/2 lb. Union Black S, 2 oz. Diamine Fast Yellow A, 5 oz. Naphthol Blue Black, 3-1/4 oz. Formyl Violet S 4 B, and 4 lb. Glauber's salt in 10 gallons dye-liquor. The goods are treated at the boil in this bath for one hour, Italian cloths have frequently if not always to pass through a finishing process to give them lustre. This treatment, especially with blues and blacks, has a tendency to affect the shades, reddening them. With some dye the colour comes back on the goods becoming cold again, but with others this is not the case. If desired the goods may be subjected after dyeing to a treatment with alum or, better, bichromate of potash. The goods after being dyed are rinsed and then passed into a bath at a temperature of 140° F., containing 3 lb. bichromate of potash and 1-1/2 to 2 oz. sulphuric acid. After being chromed in this for about half an hour they are well washed. This chroming thoroughly fixes the colour on the cotton and it will not change while being finished, either by crabbing, steaming or hot pressing. _Gold Brown_.--Use 1-1/2 lb. Diamine Cutch, 6-1/2 oz. Diamine Fast Yellow B, 1 oz. each Union Black, Naphthol Blue Black and Azo Red A. _Walnut Brown_.--A fine shade is got with 1-1/4 lb. Union Black S, 1-1/4 lb. Diamine Brown M, 3-1/4 oz. Diamine Fast Yellow B, 13 oz. Indian Yellow G, and 1 oz. Naphthol Blue Black. After dyeing the goods should be chromed with 3 lb. bichromate of potash and 2 oz. sulphuric acid. _Dark Blue_.--A good full shade is got with 2-1/4 lb. Union Black S, 9-1/2 oz. Diamine Brilliant Blue G, 6-1/2 oz. Alkaline Violet (p. 177) C A, and 1/4 lb. Alkaline Blue F. Treatment in a bath of 1/2 lb. alum and 1/2 oz. soda at 130° F. will fix the colour against finishing. _Silver Grey_.--A fine grey can be got from 1-3/4 oz. Diamine Black B H, 1/2 oz. Diamine Orange B, 1/2 oz. Naphthol Blue Black, and 1/2 oz. Formyl Violet. _Navy Blue_.--Use 1-1/4 lb. Union Black S, 3 lb. Diamine Black B H, 1/2 oz. Naphthol Blue Black, 1/2 lb. Formyl Violet S 4 B, and 2-1/2 oz. Alkaline Blue B. _Red Plum_.--Use a dye-bath containing 2-1/2 lb. Oxydiamine Violet B and 3-1/4 oz. Formyl Violet S 4 B. _Dark Green_.--A fine shade can be dyed in a bath containing 3 lb. Diamine Green B and 1-1/2 lb. Diamine Black H W. _Dark Slate_.--Use 4 lb. Diamine Black H W, 2 oz. Naphthol Blue Black, and 3 oz. Azo Red A. _Sage_.--Use a dye-bath containing 4 lb. Diamine Bronze G and 1-1/4 oz. Naphthol Blue Black. _Dark Brown_.--A fine dark shade is got from 2-1/2 lb. Diamine Brown V, and 2 oz. Naphthol Blue Black. _Peacock Green_.--Use 3-3/4 lb. Diamine Steel Blue L, 13 oz. Diamine Fast Yellow B, 14-1/2 oz. Thiocarmine R, and 2-1/4 oz. Indian Yellow G in a bath of 4 lb. Glauber's salt per gallon of dye-liquor. _Dark Sea Green_.--Use 9 oz. Diamine Steel Blue L, 3-3/4 oz. Diamine Fast Yellow B, 1/2 oz. Diamine Orange G, 1-1/4 oz. Naphthol Blue Black, and 3/4 oz. Indian Yellow G. _Dark Brown_.--Use 1 lb. Diamine Orange B, 1 lb. Diamine Fast Yellow B, 13-3/4 oz. Union Black S, 1 lb. Diamine Brown M, and 1/2 lb. Indian Yellow G. Fix in an alum bath after dyeing. _Dark Stone_.--Use 1/2 lb. Diamine Orange B, 3-3/4 oz. Union Black, 1/4 oz. Diamine Bordeaux B, 1-1/2 oz. Azo Red A, and 3/4 oz. Naphthol Blue Black. _Black_.--A very fine black can be got from 3-1/2 lb. Oxydiamine Black R M, 2 lb. Union Black S, 9-1/2 oz. Naphthol Blue Black and (p. 178) 4 oz. Formyl Violet S 4 B, chroming after dyeing as described above. _Dark Grey_.--A fine bluish, shade of grey is got from 7 oz. Diamine Black B H, 2-1/4 oz. Diamine Orange G, 2-1/2 oz. Naphthol Blue Black, and 1 oz. Orange E N Z. _Dark Blue_.--A fine shade is got by using 2 lb. Diamine Black B H, 1/2 lb. Diamine Black H W and 3-1/2 oz. Alkaline Blue 6 B. _Drab_.--Use 3-1/2 oz. Diamine Orange B, 3/4 oz. Union Black, 1/8 oz. Diamine Bordeaux B, 3/4 oz. Azo Red A, and 1/4 oz. Naphthol Blue Black. _Plum_.--Use 2-1/2 lb. Diamine Violet N, 9-1/2 oz. Union Black, and 1 lb. Formyl Violet S 4 B. _Bright Yellow_.--Use a dye-bath containing 4 lb. Thioflavine S, 2 lb. Naphthol Yellow S, 10 lb. Glauber's salt, and 2 lb, acetic acid. _Pink_.--Use 1/6 oz. Diamine Rose B D, 1/4 oz. Diamine Scarlet B, 1/2 oz. Rhodamine B and 20 lb. Glauber's salt. _Scarlet_.--A fine shade is got from 1-1/2 lb. Diamine Scarlet B, 1/2 oz. Diamine Red 5 B and 20 lb. Glauber's salt. _Orange_.--Use a dye-bath containing 3-1/2 lb. Diamine Orange G, 14-1/2 oz. Tropæoline O O, and 2-3/4 oz. Orange extra. _Sky Blue_.--Use 1-1/2 oz. Diamine Sky Blue and 1-1/4 oz. Alkaline Blue B. _Bright Blue_.--A fine shade similar to that formerly known as Royal Blue is got by using 1-1/2 lb. Diamine Brilliant Blue G, and 9-1/4 oz. Alkaline Blue 6 B. _Maroon_.--Use 3 lb. Diamine Bordeaux B, 2 lb. Diamine Violet N, and 3-1/4 oz. Formyl Violet S 4 B. _Green_.--A fine green similar in shade to that used for billiard-table cloth is got from 2 lb. Diamine Fast Yellow B, 2 lb. Diamine Steel Blue L, 14-1/2 oz. Thiocarmine R and 7-1/4 oz. Indian Yellow G. _Gold Brown_.--A fine brown is got from 3 lb. Diamine Orange B, (p. 179) 1/2 lb. Union Black, 2-1/2 oz. Diamine Brown, 3/4 oz. Naphthol Blue Black, and 1/2 lb. Indian Yellow G. _Navy Blue_.--Use 3-1/4 lb. Diamine Black B H, 1-1/2 lb. Diamine Brilliant Blue G, and 1/2 lb. Alkaline Blue. _Fawn Drab_.--A fine shade is got by dyeing in a bath containing 6-3/4 oz. Diamine Orange B, 1-3/4 lb. Union Black, 1/4 oz. Naphthol Blue Black, 1/4 oz. Diamine Bordeaux B, and 1 oz. Azo Red A. In all these colours the dye-baths contain Glauber's salt at the rate of 4 lb. per 10 gallons. _Dark Brown_.--2-1/2 lb. Diamine Orange B, 13 oz. Diamine Bordeaux B, 1-1/2 lb. Diamine Fast Yellow B, 1-3/4 lb. Union Black, and 3-1/2 oz. Naphthol Black. _Drab_.--1-3/4 lb. Diamine Fast Yellow R, 3-1/4 oz. Diamine Bordeaux B, 2-1/2 oz. Union Black, 1/2 oz. Naphthol Blue Black, and 1-1/4 oz. Indian Yellow G. _Dark Blue_.--Use in the dye-bath 4-1/4 lb. Diamine Dark Blue B, 1-1/2 lb. Diamine Brilliant Blue G, 3/4 lb. Formyl Violet S 4 B, and 5 oz. Naphthol Blue Black. _Blue Black_.--Use 3-1/4 lb. Union Black S, 1-1/2 lb. Oxydiamine Black B M, 6-1/2 oz. Naphthol Blue Black, and 1/4 lb. Formyl violet S 4 B. _Dark Walnut_.--2-3/4 lb. Diamine Brown M, 1-1/2 lb. Union Black S, and 11-1/4 oz. Indian Yellow G. _Peacock Green_.--Use in the dye-bath 3-1/2 lb. Diamine Black H W, 5-1/6 oz. Diamine Fast Yellow B, 1-1/2 lb. Thiocarmine R, and 1-1/6 oz. Indian Yellow G. _Slate Blue_.--Use in the dye-bath 6-1/2 oz. Diamine Catechine B, 4-3/4 oz. Diamine Orange B, 2-1/2 oz. Union Black, 2-3/4 oz. Orange E N Z, and 1-3/4 oz. Naphthol Blue Black. _Dark Sage_.--A good shade is dyed with 1 lb. Diamine Orange B, 6-1/2 oz. Union Black, 1-3/4 oz. Diamine Brown M, 3-1/4 oz. Azo Red A, and 2-1/4 oz. Naphthol Blue Black. _Navy Blue_.--Use 2 lb. Diamine Dark Blue B, 1-1/4 lb. Lanacyl (p. 180) Violet B, and 7 oz. Naphthol Blue Black. _Bronze Green_.--A good shade is dyed with 2 lb. Diamine Orange B, 5 oz. Diamine Brown N, 3/4 lb. Union Black S, 1 lb. Indian Yellow G, and 2 oz. Naphthol Blue Black. _Black_.--Use 2-1/2 lb. Oxydiamine Black B M and 1-1/2 lb. Naphthylamine Black 6 B. Another recipe, 2-1/4 lb. Oxydiamine Black B M, 1 lb. Diamine Brown M, 1 lb. Orange E N Z, and 2 oz. Naphthol Blue Black. _Dark Brown_.--Use 1-1/2 lb. Oxydiamine Black B M, 15-1/2 oz. Diamine Brown M, 1-3/4 lb. Indian Yellow G, and 2-3/4 oz. Naphthol Blue Black. Another combination, 1-1/2 lb. Oxydiamine Black B M, 1-1/2 lb. Orange E N Z, 1 lb. Indian Yellow G, and 5 oz. Naphthol Blue Black. _Scarlet_.--3 lb. Benzopurpurine 4 B, 3/4 oz. Ponceau 3 R B, and 1/2 lb. Curcumine S. _Crimson_.--1/2 lb. Congo Corinth G, 2 lb. Benzopurpurine 10 B, and 1/2 lb. Curcumine S. _Bright Blue_.--2 lb. Chicago Blue 6 B, 3 oz. Alkali Blue 6 B, 1-1/2 oz. Zambesi Blue R X. After dyeing, rinse and develop in a bath of 8 oz. sulphuric acid in 10 gallons water, then rinse well. _Dark Blue_.--2-1/2 lb. Columbia Fast Blue 2 G, 3 oz. Sulphon Azurine D, 3 oz. Alkali Blue 6 B. After dyeing, rinse and develop in a bath of 8 oz. sulphuric acid in 20 gallons of water. _Orange_.--9 oz. Congo Brown G, 1-1/2 lb. Mikado Orange 4 R O, and 1-1/2 oz. Mandarine G. _Dark Green_.--2 lb. Columbia Green, 1/2 lb. Sulphon Azurine D, 1/2 lb. Zambesi Blue B X, 1-1/2 oz. Curcumine S. _Black_.--4 lb. Columbia Black F B, and 2 lb. Wool Black 6 B. _Pale Sage Green_.--5 oz. Zambesi Black D, 3/4 lb. Chrysophenine G, and 1-1/2 lb. Curcumine S. _Slate_.--1/2 lb. Zambesi Black D, 3/4 oz. Zambesi Blue R X, (p. 181) 1/2 oz. Mikado Orange 4 R O, and 1-1/2 oz. Acid Violet 6 B. _Dark Grey_.--1 lb. Columbia Black F B, 3 oz. Zambesi Black B, and 3/4 oz. Sulphon Azurine D. _Drab_.--1-1/2 oz. Zambesi Black D, 3/4 oz. Mandarine G extra, 1/4 oz. Curcumine extra, and 3 oz. Mikado Orange 4 R O. _Brown_.--5 oz. Zambesi Black D, 3/4 oz. Mandarine G extra, 1-1/2 oz. Orange T A, and 2 oz. Mikado Orange 4 R O. _Nut Brown_.--3/4 lb. Congo Brown G, 1/4 lb. Chicago Blue R W, and 3/4 lb. Mikado Orange 4 R O. _Dark Brown_.--1 lb. Congo Brown G, 1-1/2 lb. Benzopurpurine 4 B, 1-1/2 lb. Zambesi Black F, and 1/2 lb. Wool Black 6 B. _Stone_.--1 oz. Zambesi Black D, 1/4 oz. Mandarine G, 1/4 oz. Curcumine extra, and 1-1/4 oz. Mikado Orange 4 R O. _Slate Green_.--3 oz. Zambesi Black D, 1-1/2 oz. Guinea Green B. _Sage Brown_.--1/2 lb. Zambesi Black D, 1-1/2 oz. Mandarine G extra, 3 oz. Curcumine extra, 3 oz. Acid Violet 6 B, 6 oz. Mikado Orange 4 R O, and 4-1/2 oz. Curcumine S. _Cornflower Blue_.--3 oz. Chicago Blue 4 R, 1/4 lb. Zambesi Blue R X, 1/4 lb. Acid Violet 6 B, and 3/4 oz. Zambesi Brown G. _Dark Brown_.--1-1/2 lb. Brilliant Orange G, 1/2 lb. Orange T A, 1 lb. Columbia Black F B, and 1/4 lb. Wool Black 6 B. _Dark Blue_.--2 lb. Chicago Blue R W, 1 lb. Zambesi Blue R X, 1/2 lb. Columbia Black F B, 10 oz. Guinea Green B, and 1/2 lb. Guinea Violet 4 B. The Janus dyes may be used for the dyeing of half wool union fabrics. The best plan of working is to prepare a bath with 5 lb. of sulphate of zinc. In this the goods are worked at the boil for five minutes, then there is added the dyes (previously dissolved in water), and the working continued for a quarter of an hour; then there is added 20 lb. Glauber's salt and the working at the boil continued for one hour, (p. 182) at the end of which time the dye-bath will be fairly well exhausted of colour. The goods are now taken out and put into a fixing bath of sumac or tannin, in which they are treated for fifteen minutes. To this same bath there is next added tartar emetic and 1 lb. sulphuric acid, and the working continued for a quarter of an hour; then the bath is heated to 160° F., when the goods are lifted, rinsed and dried. In the recipes the quantities of dyes, sumac or tannin, and tartar emetic only are given, the other ingredients and processes are the same in all. _Dark Blue_.--2-1/4 lb. Janus Dark Blue B, and 1/2 lb. Janus Green B, in the dye-bath; 16 lb. sumac extract and 2 lb. tartar emetic in the fixing bath. _Blue Black_.--3-1/2 lb Janus Black I and 1/3 lb. Janus Black I I in the dye-bath, and 16 lb. sumac extract and 2 lb. tartar emetic in the fixing bath. _Dark Brown_.--2-1/2 lb. Janus Brown B, 1 lb. Janus Black I, 3-1/2 oz. Janus Yellow G, and 5 oz. Janus Red B in the dye-bath, with 16 lb. sumac extract and 2 lb. tartar emetic in the fixing bath. _Drab_.--1-1/2 oz. Janus Yellow R, 1/4 oz. Janus Red B, 1 oz. Janus Blue R, and 1/4 oz. Janus Grey B B, in the dye-bath, and 4 lb. sumac extract and 1 lb. tartar emetic in the fixing-bath. _Grey_.--5 oz. Janus Blue R, 3-1/4 oz. Janus Grey B, 1-1/2 oz. Janus Yellow R, and 1/4 oz. Janus Red B in the dye-bath, with 4 lb. sumac extract and 1 lb. tartar emetic in the fixing-bath. _Nut Brown_.--1 lb. Janus Brown R, 8 oz. Janus Yellow R, and 1-1/2 oz. Janus Blue B in the dye-bath, and 8 lb. sumac extract and 1 lb. tartar emetic in the fixing-bath. _Walnut Brown_.--3 lb. Janus Brown B, 1 lb. Janus Red B, 1 lb. Janus Yellow R, and 1-1/4 oz. Janus Green B in the dye-bath, with 8 lb. sumac extract and 1 lb. tartar emetic in the fixing-bath. _Crimson_.--2-1/2 lb. Janus Red B, and 8 oz. Janus Claret Red B (p. 183) in the dye-bath, with 8 lb. sumac extract and 1 lb. tartar emetic in the fixing-bath. _Dark Green_.--1-1/2 lb. Janus Green B, 1 lb. Janus Yellow R, and 8 oz. Janus Grey B in the dye-bath, with 4 lb. sumac extract and 1-1/4 lb. tartar emetic in the fixing-bath. _Chestnut Brown_.--1 lb. Janus Brown R and 1 lb. Janus Yellow R in the dye-bath, and 8 lb. sumac extract and 1 lb. tartar emetic in the fixing-bath. Before the introduction of the direct dyes the method usually followed, and indeed is now to a great extent, is that known as Cross-dyeing. The goods were woven with dyed cotton threads of the required shade and undyed woollen threads; after weaving and cleansing the woollen part of the fabric was dyed with acid dyes such as Acid Magenta, Scarlet R, Acid Yellow, etc. In such methods care has to be taken that the dyes used for dyeing the cotton are such as stand acids, a by no means easy condition to fulfil at one time. Many of the direct dyes are fast to acids and therefore lend themselves more or less readily to cross-dyeing. For details of the dyes for cotton reference may be made to the sections on dyeing with the direct colours in the companion volume to this book on _Dyeing of Cotton Fabrics_. #Shot Effects.#--A pleasing kind of textile fabric which is now made and is a great favourite for ladies' dress goods is where the cotton of a mixed fabric is thrown up to form a figured design. It is possible to dye the two fibres in different colours and so produce a variety of shot effects. These latter are so endless that it is impossible here to enumerate all that may be produced. It will have to suffice to lay down the lines which may be followed to the best advantage, and then give some recipes to illustrate the remarks that have been made. The best plan for the production of shot effects upon union fabrics is to take advantage of the property of certain acid dyes which dye only (p. 184) the wool in an acid bath and of many of the direct colours which will only dye the cotton in an alkaline bath. The process, working on these lines, becomes as follows: The wool is first dyed in an acid bath with the addition of Glauber's salt and bisulphate of soda or sulphuric acid, the goods are then washed with water containing a little ammonia to free them from the acid and afterwards dyed with the direct colour in an alkaline bath. Fancy or the mode shades are obtained by combining suitable dye-stuffs. If the cotton is to be dyed in light shades it is advantageous to dye on the liquor at 65° to 80° F., with the addition of 3-1/4 oz. Glauber's salt, and from 20 to 40 grains borax per gallon water. The addition of an alkali is advisable in order to neutralise slight quantities of acid which may have remained in the wool, and to prevent the dye-stuff from dyeing the cotton too deep a shade. Very light shades can also be done on the padding machine. The dye-stuffs of Group (2), which have been previously enumerated, do not stain the wool at all or only very slightly and are therefore the most suitable. Less bright effects can be produced by simply dyeing the goods in one bath. The wool is first dyed at the boil with the wool dye-stuff in a neutral bath, the steam is then shut off and the cotton dyed by adding the cotton dye-stuff to the bath and dyeing without again heating. By passing the goods through cold water to which some sulphuric or acetic acid is added the brightness of most effects is greatly increased. _Gold and Green_.--First bath, 1 lb. Cyanole extra, 7-1/4 oz. Acid Green, 1-1/2 oz. Orange G G, and 10 lb. bisulphate of soda; work at the boil for one hour, then lift and rinse well. Second bath, 4 lb. Diamine Orange G and 15 lb. Glauber's salt; work in the cold or at a lukewarm heat. Third bath at 120° F., 4 oz. Chrysoidine and 1/4 oz. Safranine. _Black and Blue_.--First bath, 3-1/2 lb. Naphthol Black 3 B and (p. 185) 10 lb. bisulphate of soda. Second bath, 2 lb. Diamine Sky Blue and 13 lb. Glauber's salt. Third bath, 6-1/2 oz. New Methylene Blue N; work as in the last recipe. _Green and Claret_.--First bath, 3-1/2 lb. Naphthol Red C and 10 lb. bisulphate of soda. Second bath, 2 lb. Diamine Sky Blue F F, 1-1/4 lb. Thioflavine S, and 15 lb. Glauber's salt. _Gold Brown and Blue_.--First bath, 2-1/2 oz. Orange E N Z, 1-1/2 oz. Orange G G, 1/4 oz. Cyanole extra, and 10 lb. bisulphate of soda. Second bath, 14 oz. Diamine Sky Blue F F and 15 lb. Glauber's salt. _Dark Brown and Blue_.--First bath, 1/2 lb. Orange G G, 1-1/2 oz. Orange E N Z, 1-1/2 oz. Cyanole extra and 10 lb. bisulphate of soda. Second bath, 12 oz. Diamine Sky Blue F F and 15 lb. Glauber's salt. _Black and Green Blue_.--First bath, 3 lb. Orange G G, 1 lb. Brilliant cochineal 4 R, 1 lb. Fast Acid Green B N, and 10 lb. Glauber's salt. Second bath, 1-3/4 lb. Diamine Sky Blue F F, 3-1/4 lb. Thioflavine S, and 15 lb. Glauber's salt. We may here note that in all the above recipes the second bath (for dyeing the cotton) should be used cold or at a lukewarm heat, and as strong as possible. It is not completely exhausted of colour, only about one-half going on the fibre. If kept as a standing bath this feature should be borne in mind and less dye-stuff used in the dyeing of the second and following lots of goods. _Blue and Gold Yellow_.--3 lb. Diamine Orange G, 13 oz. Naphthol Blue G, 14-1/2 oz. Formyl Violet S 4 B, and 15 lb. Glauber's salt; work at just under the boil. _Brown and Blue_.---1 lb. Diamine Steel Blue L, 9-1/2 oz. Diamine Sky Blue, 1 lb. Orange E N Z, 1 lb. Indian Yellow G, 1-3/4 oz. Naphthol Blue Black and 15 lb. Glauber's salt. Work at 170° to 180° F. In these two last recipes only one bath is used, all the dyes (p. 186) being added at once. This is possible if care be taken that dye-stuffs are used which will dye wool and not cotton from neutral baths and dyes which dye cotton better than wool. The temperature should also be kept below the boil and carefully regulated as the operation proceeds and the results begin to show themselves. _Grey and Orange_.--First bath, 3 oz. Orange extra, 1-1/4 lb. Cyanole extra, 11 lb. Azo Red A, and 10 lb. bisulphate of soda. Second bath, 5 oz. Diamine Orange D C and 3 oz. Diamine Fast Yellow B. _Green and Red_.--First bath, 2 lb. Croceine A Z and 10 lb. Glauber's salt. Second bath, 1 lb. Diamine Sky Blue F F, 1/2 lb. Thioflavine S, and 15 lb. Glauber's salt. _Brown and Violet_.--First bath, 3/4 lb. Orange extra, 3/4 lb. Cyanole extra, and 10 lb. bisulphate of soda. Second bath, 5 oz. Diamine Brilliant Blue G and 15 lb. Glauber's salt. _Black and Yellow_.--First bath, 7 lb. Naphthol Black B, 1/2 lb. Fast Yellow S, and 10 lb. bisulphate of soda. Second bath, 3 lb. Diamine Fast Yellow A and 15 lb. Glauber's salt. _Black and Pink_.--Black as above. Pink with Diamine Rose B D (see above). _Green and Buff_.--First bath, 1/4 lb. Orange extra, 3/4 oz. Fast Yellow S and 10 lb. bisulphate of soda. Second bath, 3/4 lb. Diamine Sky Blue F F, 1/2 lb. Thioflavine S, and 15 lb. Glauber's salt. _Orange and Violet_.--First bath, 9 oz. Orange extra and 10 lb. bisulphate of soda. Second bath, 3/4 lb. Diamine Violet N and 10 lb. Glauber's salt. _Black and Blue_.--First bath, Naphthol Black, as given above. Second bath, Diamine Sky Blue, as given above. _Black and Yellow_.--Add first 1 lb. Wool Black 6 B and 10 lb. Glauber's salt, then when the wool has been dyed add 2 lb. Curcumine S to dye the cotton in the same bath. _Green and Red_.--Dye the wool by using 3 lb. Guinea Green B, (p. 187) 1/4 lb. Curcumine extra, and 10 lb. Glauber's salt, then add to the bath 3/4 lb. Erika B N and 3/4 lb. Congo Corinth G. _Orange and Blue_.--Dye the wool first with 1-1/4 lb. Mandarine G, 2 oz. Wool Black 6 B, and 10 lb. Glauber's salt; then the cotton with 2 lb. Columbia Blue G. _Blue and Orange_.--Dye the wool first with 3/4 lb. Guinea Violet B, 3/4 lb. Guinea Green B, and 10 lb. Glauber's salt; then dye the cotton with 2 lb. Mikado Orange 4 R O. _Green and Orange_.--Dye the wool with 3 lb. Guinea Green B, 1/4 lb. Curcumine extra and 10 lb. Glauber's salt, then dye the cotton in the same bath with 1-1/2 lb. Mikado Orange 4 R O. CHAPTER VI. (p. 188) DYEING OF GLORIA. Gloria is a material which during the last few years has become of considerable importance as furnishing a fine lustrous fabric at a comparatively low price. The perfection to which the art of dyeing has attained and the facilities now available to the dyer, enable this to be produced more beautiful than ever, and naturally an increased demand for it as a dress fabric has developed. Gloria is woven from the two fibres, wool and silk, of a fine texture to enable it to be used in the place of a silk fabric. Formerly it was usually woven with the wool and silk yarns already dyed, especially when a "shot" effect was to be produced, this being done by a twill weave of the fabric and by the use of yarns of two very different colours in the case of "shot" fabrics. By the introduction of dye-stuffs derived from coal tar the cloth is now dyed after being woven, care being taken to choose those which will dye the two fibres equally well when self-shades are wanted, or those which will dye one fibre better than the other, and thus allow a woven piece of gloria to be dyed of two different colours. As most dyers know, the most brilliant effects are obtained when the finished woven piece can be dyed. Then all the grease and dirt which has become attached to it during the operations of spinning the yarns and weaving the pieces can be removed before dyeing, thus leaving the fabric in a perfectly clean condition. Thus no after cleansing is required, whereas when the (p. 189) fibres are dyed in the yarn the goods must be cleansed after weaving to free them from dirt, and such cleaning has a somewhat deleterious effect upon the brilliancy of the colour of the finished fabric, more especially in the case of light colours. Gloria may be in one colour only, a self-colour as it is called; this case is comparatively simple, the only care that is required being to select dyes which have an equal affinity for the two fibres or which give but slightly different shades. Still, some good effects are obtained when dyes are used which dye the silk and wool different colours but give the combined effect of a self-colour. Or the fibre may be purposely dyed in two different colours in some cases to give the "shot" effect. This is much more troublesome, but with a little care can be carried out with good results. The dyes available for dyeing gloria may be classified, according to their behaviour in regard to their dyeing of the two fibres, into three groups as follows:-- _Group A_.--Those which will dye the two fibres of equal shade. _Group B_.--Those which will dye the wool at boiling heat more readily than the silk. _Group C_.--Those which will dye the silk only in a cold bath. _Group A_ consists of those dyes which can be used in dyeing self-colours on gloria from acid baths. It includes Alkali Blue, Naphthylamine Blacks, Naphthol Green B, Indian Yellow, Croceine A Z, Croceine Orange, Orange R, Brilliant Croceine M, Rose Bengale, Thiocarmine R, Soluble Blue, Formyl Violet S 4 B, Acid Green, Croceine Orange G, Carmoisin, Acid Violet 5 B, Fast Acid Violet 10 B, Fast Green Bluish, Rhodamine, Silk Blue, Victoria Black, Archil, Turmeric, Safranine, Auramine, Quinoline Yellow, Azoflavine, Victoria Blue and Bismarck Brown. _Group B_ comprises those dye-stuffs which in a boiling acid (p. 190) bath dye the wool deeper than the silks, in other words have more affinity for the wool than the silk, Tropæoline O, Acid Magenta, Indigo Extract, Phloxine, Naphthol Yellow, Orange G G, Scarlet S, Azo Red A, Eosines, Thiocarmine R, Naphthol Black B B, New Victoria Black Blue, Erythrosine, and Roccelline. The silk becomes tinted to a more or less extent when in such a bath, but often the colour is readily removed either by subsequent passage through boiling water or through hot soap liquor. A very good clearing can be effected by the use of a bath of acetate of ammonia. Naphthol Yellow, for instance, only imparts a very faint shade of yellow when thus dyed, and this is easily removed by boiling-water treatment. _Group C_.--Those dye-stuffs which will dye the silk more readily in a cold bath than the wool. These comprise most of the basic dyes, such as Thioflavine T, Safranine, Brilliant Green, Methyl Violet, Magenta, New Methylene Blue, Bismarck Brown, Rose Bengale, Phloxine, Acid Greens, Formyl Violet S 4 B, Rhodamine, Solid Blue, etc. Gloria may be dyed either by a one-bath or two-bath process, and either one or two colours, as may be required. In both cases advantage may be taken of the different affinities of the two fibres for the dye-stuffs used, as, for instance, the silk may be dyed brown, the wool olive by using a mixture of Acid Yellow, Indigo extract and Orange G. Indigo extract, Cochineal, Acid Magenta, Picric acid, Naphthol Yellow, and Tartrazine dye the wool only at the boil. The following recipes will serve to illustrate the foregoing remarks and show how this important fabric may be dyed:-- _Deep Gold_.--The dye-bath is made from 2 lb. Indian Yellow, 10 lb. Glauber's salt, and 2 lb. sulphuric acid, dyed at the boil. In this and following recipes the quantities are for 100 lb. _Orange_.--The dye-bath is made with 2 lb. Indian Yellow, 19 lb. (p. 191) Glauber's salt, and 2 lb. sulphuric acid. _Scarlet_.--Make the dye-bath with 2 lb. Scarlet 3 R, 10 lb. Glauber's salt, and 2 lb. sulphuric acid. Another scarlet is got from 2 lb. sulphuric acid. Another scarlet is got from 2 lb. Croceine Scarlet 3 B, 2 lb. sulphuric acid, and 10 lb. Glauber's salt; by using the 5 B Scarlet a bluer shade can be dyed. Azo Cochineal also dyes a fine scarlet on gloria. _Crimson_.--Make the dye-bath with 1 lb. Carmoisin B, 10 lb. Glauber's salt, and 2 lb. sulphuric acid. The 7 B Croceine Scarlet also dyes a fine crimson of a more fiery tone than the last, while 2-1/2 lb. Azo Fuchsine G dyes a bluer shade of crimson. _Rose_.--A fine rose is obtained with 2 lb. Rhodamine B, 10 lb. Glauber's salt, and a little acetic acid. 1 lb. Phloxine dyes a fine deep rose; the silk comes out a paler colour than the wool, but the general effect is good. _Deep Maroon_.--Make the dye-bath from 1-1/2 lb. Croceine A Z, 1/2 lb. Indian Yellow, 1/4 lb. Formyl Violet S 4 B, 10 lb. bisulphate of soda. Enter the goods, work at the boil for an hour, then cool down to 120° F., enter an equal quantity of dye-stuff and work for an hour longer. _Pale Maroon_.--Make the dye-bath with 3 lb. Azo Bordeaux, 10 lb. Glauber's salt and 2 lb. sulphuric acid. _Black_.--Prepare the dye-bath with 5 lb. Naphthylamine Black D, 1 lb. Acid Green B, 10 lb. Glauber's salt, and 2 lb. sulphuric acid; work at the boil for twenty minutes, then allow to cool to 120° or 130° F., then work an hour longer. Another black can be dyed in a similar way from 5 lb. Victoria Black B, 10 lb. Glauber's salt, and 2 lb. sulphuric acid. _Violet_.--Use 2 lb. Acid Violet 5 B, or 2 lb. Formyl Violet S 4 B, 10 lb. Glauber's salt, and 2 lb. sulphuric acid. Fast Acid Violet 10 B gives a bluer shade than the above. _Green_.--Make the dye-bath with 2 lb. Acid Green G G, 10 lb. (p. 192) Glauber's salt, and 2 lb. sulphuric acid, working at the boil. This gives a bright yellow shade of green; a bluer shade can be got from Acid Green 6 B or Acid Green B, while Fast Green Bluish gives very blue greens. _Coeruleum Blue_.--Dye with 3/4 lb. Silk Blue B E S, 10 lb. Glauber's salt, and 2 lb. sulphuric acid; this gives a very fine bright blue. _Deep Indigo Blue_.--Dye with 4-1/2 lb. Solid Blue R, 2 lb. Thiocarmine R paste, 10 lb. Glauber's salt and 2 lb. sulphuric acid. _Deep Violet Brown_.--Dye with 3 lb. Croceine A Z, 1-1/4 lb. Indian Yellow, 1-3/4 lb. Formyl Violet S 4 B, 10 lb. Glauber's salt, and 2 lb. sulphuric acid for an hour at the boil, and for an hour at 120° F. _Blue Black_.--Make the dye-bath with 5 lb. New Victoria Blue Black, 10 lb. Glauber's salt, and 2 lb. sulphuric acid, working at the boil. Another plan is to use 5 lb. Naphthylamine Black 4 B and 10 lb. bisulphate of soda. _Dark Grey_.--Prepare a dye-bath with 3 lb. Naphthol Black 3 B, 4 lb. Naphthol Green B, 1 lb. Amaranth, 10 lb. Glauber's salt, 8 lb. copperas, and 3 lb. sulphuric acid, working at the boil for an hour and then rinsing in water to which a little acetate of ammonia has been added. The silk is dyed grey and the wool a black. _Brown_.--A fine yellow brown shot with lilac is obtained by first dyeing in a bath of 5 lb. Naphthol Yellow, 10 lb. Glauber's salt and 2 lb. sulphuric acid. Wash in hot water, then dye with 2-1/2 lb. Solid Blue P G, 1-1/2 oz. Methyl Violet B O, and 5 lb. acetic acid in the cold. _Wool, Orange; Silk, Pale Green._--Dye the wool with 1-1/2 lb. Orange G G, 6 oz. Naphthol Green B, 2-1/2 oz. Naphthol Red C, 10 lb. bisulphate of soda, and 2 lb. sulphuric acid; and the silk with 1/2 lb. Milling Yellow and 1/2 lb. Acid Green. _Wool, Black; Silk, Light Grey._--Dye in a bath with 5 lb. (p. 193) Anthracene Acid Black S T, 4-1/2 oz. Fast Yellow S, 10 lb. bisulphate of soda, and 2 lb. sulphuric acid. The silk is cleaned by boiling for ten minutes in a soap bath. _Wool, Bright Red; Silk, Blush Rose._--The gloria silk is dyed in a bath of 3 lb. Naphthol Red O, 10 lb. bisulphate of soda, and 2 lb. sulphuric acid. After dyeing, soap for ten minutes. _Wool, Black; Silk, Green._--Dye the wool in a bath containing 5 lb. Anthracene Acid Black S T, 5 oz. Fast Yellow S, 2 lb. oxalic acid, 10 lb. Glauber's salt, and 15 lb. acetic acid. Work the goods in this at the boil for an hour, then lift, add 3/4 lb. bichromate of potash, and boil for twenty minutes longer. Clean the silk by boiling in a bath of soap for twenty minutes, then dye in a cold bath containing 1 lb. Thioflavine T and 1 lb. Brilliant Green. _Wool, Dark Maroon; Silk, Pale Blue._--After the manner described in the first recipe, dye the wool with 1 lb. Orange G G, 3 lb. Naphthol Green B, 2 lb. Brilliant Cochineal 2 R, 10 lb. bisulphate of soda, and 2 lb. sulphuric acid. Dye the silk with 1-1/2 lb. Pure Blue O T. _Wool, Violet; Silk, Green._--Make the dye-bath with 1 lb. Acid Violet 4 B, 9 oz. Indigotine extra, 10 lb. bisulphate of soda, and 2 lb. sulphuric acid. The dyeing is carried on at the boil until the bath is exhausted of colour, whereupon the goods are well rinsed in water. They are next soaped at 160° F. for ten minutes in a liquor containing 1/2 oz. soap per gallon, then rinsed. Next a dye-bath is made with 1 lb. Acid Green, 8 oz. Milling Yellow O, and 1 lb. acetic acid, the goods being treated in this in the cold until the desired shade is obtained, then lifted, rinsed and dried. _Violet and Pink._--A fine effect of violet shot with pink is obtained by dyeing in a bath of 1-1/2 lb. Indigo extract, 1/2 lb. Rhodamine B, 10 lb. Glauber's salt, and 2 lb. sulphuric acid. _Brown Olive and Green_ is dyed in a bath made with 1 lb. (p. 194) Quinoline Yellow, 1 lb. Azo Fuchsine G, 1/4 lb. Fast Green Bluish, 10 lb. Glauber's salt, and 2 lb. sulphuric acid. By using about half the above quantities of dye-stuffs a drab effect shot with green can be obtained. _Crimson and Green._--The first bath is made from 4 lb. Azo Red A and 10 lb. bisulphate of soda, worked for an hour at the boil; then treat in a weak bath of acetate of ammonia; and dye the silk in a cold bath of 2 oz. Solid Green Crystals, 1/4 lb. Thioflavine T, and 5 lb. acetic acid. _Violet and Pink._--Dye in a bath of 1-1/4 lb. Indigo extract, 10 lb. Glauber's salt and 2 lb. sulphuric acid. _Brown and Pink._--This is dyed in a bath made from 1-1/4 lb. Fast Yellow, 5 oz. Rhodamine B, 1/4 lb. indigo extract, 10 lb. Glauber's salt, and 2 lb. sulphuric acid. The silk dyes a pale pink while the general effect is that of a fine fawn brown with a reddish shot effect. _Dark Green and Pale Crimson._--This is done in two baths, the first is made with 8 lb. Naphthol Green B, 10 lb. Glauber's salt, 3 lb. sulphuric acid, and 7 lb. copperas, working at the boil; then treat with hot water and dye in a fresh bath with 6 oz. Safranine Prima and 5 lb. acetic acid in the cold. The combined effect of the two is that of a brown shot with green. _Orange and Green._--This gives a splendid shot effect and is dyed as follows. Work for an hour at the boil, for thirty minutes in a bath of boiling water, then enter into a cold bath of 5 oz. Thioflavine T, 3 oz. Brilliant Green, and 3 lb. acetic acid; work for thirty minutes, or until shade is obtained. _Orange and Blue._--Use first dye-bath as in the last, then, after washing in hot water, dye in a bath of 2 oz. New Methylene Blue N, and 3 lb. acetic acid. _Silk, Sky Blue; Wool, Drab._--Make a dye-bath with 20 lb. acetic acid, 3/4 oz. Indigotine, 3 oz. Fast Yellow extra and 2 oz. Azo (p. 195) Fuchsine G. Work at the boil for one hour at 100° F., then pass into a bath of 3/4 oz. Turquoise Blue B B, and 2 lb. acetic acid, working for half an hour at 80°. _Silk, Pink; Wool, Pale Blue._--Make a dye-bath with 15 lb. acetic acid and 4-1/2 oz. Indigotine. Work at the boil for an hour, then pass into a bran bath as before; next enter into a dye-bath at 80° to 90° of 3/4 oz. Brilliant Rhoduline R B, 1-1/2 oz. Auramine I I, and 2 lb. acetic acid. _Silk, Green; Wool, Dark Crimson._--The first bath is made from 3 lb. Azo Fuchsine G, 1 lb. Indian Yellow G and 20 lb. acetic acid; then follows the bran and the final dye-bath, which is made from 1-1/2 oz. Imperial Green G I, and 2 lb. acetic acid. _Silk, Orange; Wool, Black._--A dye-bath is made from 2 lb. Indigotine, 2 lb. Indian Yellow G, 1/2 lb. Rhodamine G, and 20 lb. acetic acid. Work at the boil for one hour; then lift, wash and dry. _Silk, Light Green; Wool, Dark Blue._--Make a dye-bath from 1/2 lb. Azo Fuchsine G, 2 lb. Fast Light Green, and 20 lb. acetic acid. Work at the boil to shade; then lift, wash and dry. _Silk, Yellow; Wool, Terra Cotta._--A dye-bath is made from 1-1/2 oz. Indigotine, 3/4 lb. Azo Fuchsine G, 9 oz. Indian Yellow R, and 20 lb. acetic acid. Work at the boil for one hour; then lift, wash and dry. _Silk, Light Sea Green; Wool, Pale Sage._--Make the dye-bath with 1/2 lb. Fast Yellow extra, 3 oz. Azo Fuchsine G, 1-1/2 oz. Fast Green bluish, and 20 lb. acetic acid. Work as in the last recipe. _Silk, Light Green; Wool, Brown._--Make the dye-bath with 1 lb. Azo Fuchsine G, 2-1/2 lb. Fast Yellow extra, 1/2 lb. Fast Green bluish, and 20 lb. acetic acid. Work at the boil for one hour. _Silk, Pale Blue; Wool, Crimson._--Make a dye-bath with 2 lb. (p. 196) Azo Crimson L and 20 lb. acetic acid. Work at the boil for one hour, then pass into a bran bath for half an hour at 90° F., and into another bath containing 1/2 lb. Turquoise Blue G, and 2 lb. acetic acid, at 90° F., for half an hour; then wash and dry. _Silk, Light Drab; Wool, Lavender._--Make the first dye-bath from 3 oz. Indigotine, 2 oz. Azo Fuchsine G, and 20 lb. acetic acid. After working an hour at the boil, pass into a bran bath for half an hour, afterwards topping with 1-1/2 oz. Bismarck Brown R and 2 lb. acetic acid. CHAPTER VII. (p. 197) OPERATIONS FOLLOWING DYEING: WASHING, SOAPING, DRYING. After loose wool, or woollen yarns or piece goods of every description have been dyed, before they can be sent out for sale they have to pass through various operations of a purifying character. There are some operations through which cloths pass that have as their object the imparting of a certain appearance and texture to them, these are generally known as finishing processes, of these it is not intended here to speak, but only of those which precede them but follow on the dyeing operations. These processes are usually of a very simple character, and common to most colours which are dyed, and here will be noticed the appliances and manipulations necessary in the carrying out of these operations. #Squeezing or Wringing.#--It is advisable when the goods are taken out of the dye-bath to squeeze or wring them according to circumstances in order to express out all surplus dye-liquor, which can be returned to the dye-bath if needful to be used again. This is an economical proceeding in many cases, especially in working with many of the old tannin materials, like sumac, divi-divi, myrobalans, and the modern direct dyes, which during the dyeing operations are not completely extracted out of the bath, or in other words the dye-bath is not exhausted of colouring matter, and therefore it can be used again for another lot of goods simply by adding fresh material to make up for that absorbed by the first lot. Loose wool and loose cotton are somewhat difficult to deal with by (p. 198) squeezing or wringing, but the material may be passed through a pair of squeezing rollers such as are shown in figure 24, which will be more fully dealt with later on. #Yarns in Hanks.#--In the hand-dyeing process of hank-dyeing the hanks are wrung by placing one end of the hank on a wringing-horse placed over the dye-tub, and a dye-stick in the other end of the hank, giving two or three sharp pulls to straighten out the yarn and then twisting the stick round; the twisting of the yarns puts some pressure on the fibres thoroughly and uniformly squeezing out the surplus liquor from the yarn. #Hank-Wringing Machines.#--Several forms of hank-wringing machines have been devised. One machine consists of a pair of discs fitted on an axle, these discs carry strong hooks on which the hanks are placed. The operator places a hank on a pair of the hooks. The discs revolve and carry round the hank, during the revolution the hank is twisted and the surplus liquor wrung out, when the revolution of the discs carries the hank to the spot where it entered the machine, the hooks fly back to their original position, the hank unwinds, it is then removed and a new hank put in its place, and so the machine works on, hanks being put on and taken off as required. The capacity of such a machine is great and the efficiency of its working good. Mr. S. Spencer, of Whitefield, makes a hank-wringing machine which consists of a pair of hooks placed over a vat. One of the hooks is fixed, the other is made to rotate. A hank hung between the hooks is naturally twisted and all the surplus liquor wrung out, the liquor falling into the vat. #Roller Squeezing Machines for Yarn.#--Hanks may be passed through a pair of indiarubber squeezing rollers which may be so arranged that they can be fixed as required on the dye-bath. Such a pair of (p. 199) rollers is a familiar article and quite of common and general use in dye-houses. #Piece Goods.#--These are generally passed open through a pair of squeezing rollers, which are often attached to the dye-vat in which the pieces are dyed. [Illustration: Fig. 24.--Read Holliday's Yarn-squeezing Machine.] #Read Holiday's Squeezing Machine.#--In figure 24 is shown a squeezing machine very largely employed for squeezing all kinds of piece goods after dyeing or washing. It consists of a pair of heavy rollers on which, by means of the screws shown at the top, a very considerable pressure can be brought to bear. The piece is run through the eye shown on the left, by which it is made into a rope form, then over the guiding rollers and between the squeezing rollers and into (p. 200) waggons for conveyance to other machines. This machine is effective. Another plan on which roller, or rather in this case disc, squeezing machines are made is to make the bottom roller with a square groove in the centre, into this fits a disc, the cloth passing between them. The top disc can, by suitable screws, be made to press upon the cloth in the groove and thus squeeze the water out of it. WASHING. One of the most important operations following that of dyeing is the washing with water to free the goods, whether cotton or woollen, from all traces of loose dye, acids, mordanting materials, etc., which it is not desirable should be left in, as they might interfere with the subsequent finishing operations. For this purpose a plentiful supply of good clean water is required, this should be as soft as possible, free from any suspended matter which might settle upon the dyed goods and stain or speck them. Washing may be done by hand, as it frequently was in olden days, by simply immersing the dyed fabrics in a tub of water, shaking, then wringing out, again placing in fresh water to finish off. Or if the dye-works were on the banks of a running stream of clean water the dyed goods were simply hung in the stream to be washed in a very effectual manner. In these days it is best to resort to washing machines adapted to deal with the various kinds of fibrous materials and fabrics, in which they can be subjected to a current of water. #Loose Wool.#--If this has been dyed by hand then the washing may also be done in the same way by hand in a plain vat. If the dyeing has been done on a machine then the washing can be done on the same machine. [Illustration: Fig. 25.--Hank-washing Machine.] #Yarn in Hanks.#--A very common form of washing machine is shown (p. 202) in figure 25. As will be seen it consists of a wooden vat, over which are arranged a series of revolving reels on which the hanks are hung, the hanks are kept in motion through the water and so every part of the yarn is thoroughly washed. Guides keep the hanks of yarn separate and prevent any entanglement one with another. A pipe delivers constantly a current of clean water, while another pipe carries away the used water. Motion is given to the reels in this case by a donkey engine attached to the machine, but it may also be driven by a belt from the main driving shaft of the works. This machine is very effective. [Illustration: Fig. 26.--Cloth-washing Machine.] #Piece Goods.#--Piece goods are mostly washed in machines, of which two broad types may be recognised. First those where the pieces are dealt with in the form of ropes or in a twisted form, and second those where the pieces are washed while opened out full width. There are some machines in which the cloths may be treated either in the open or rope form as may be thought most desirable. Figure 26 represents a fairly well-known machine in which the (p. 203) pieces are treated in a rope-like form. It consists of a trough in which a constant current of water is maintained; at one end of this trough is a square beating roller, at the other a wood lattice roller, above the square beater and out of the trough are a pair of rollers whose purpose is to draw the cloth through the machine and also partly to act as squeezing rollers. As will be seen the cloth is threaded in rope form spirally round the rollers, passing in at one end and out at the other, pegs in a guide rail serving to keep the various portions separate. The square beater in its revolutions has a beating (p. 204) action on the cloth, tending to more effectual washing. The lattice roller is simply a guide roller. [Illustration: Fig. 27.--Cloth-washing Machine.] Figure 27 shows a washing machine very largely used in the wool-dyeing trade. The principal portion of this machine is of wood. The internal parts consist of a large wooden bowl, or oftener, as in the machine under notice, of a pair of wooden bowls which are pressed together by springs with some small degree of force. Between these bowls the cloth is placed, more or less loosely twisted up in a rope form, and the machines are made to take four, six or eight pieces or lengths at one time, the ends of the pieces being stitched together so as to make a continuous band. A pipe running along the front of the machine conveys a constant current of clean water, which is caused to impinge in the form of jets on the pieces of cloth as they run through the machine, while an overflow carries away the used water. The goods are run in this machine as long as is considered necessary for a sufficient wash, which may take half to one and a half hours. In figure 30 is shown a machine designed to wash pieces in the broad or open state. The machine contains a large number of guide rollers built more or less open, round which the pieces are guided, the ends of the pieces being stitched together, pipes carrying water are so arranged that jets of clean water impinge on and thoroughly wash cloth as it passes through, the construction of the guide rollers facilitating the efficient washing of the goods. SOAPING. Sometimes yarns or cloths have to be passed through a soap-bath after being dyed in order to brighten up the colours or develop them in some way. In the case of yarns this can be done on the reel washing (p. 205) machines such as are shown in figure 25. In the case of piece goods a continuous machine in which the washing, soaping, etc., can be carried on simultaneously is often employed. Such a machine is shown in figure 28. It consists of a number of compartments fitted with guide rollers, so that the cloth passes up and down several times through the liquors in the compartment; between one compartment and another is placed a pair of squeezing rollers. The cloth is threaded in a continuous manner, well shown in the drawing, through the machine; in one compartment it is treated with water, in another with soap liquor, and another with water, and so on, and these machines may be made with two, three or more compartments, as may be necessary for the particular work in hand. As seen in the drawing the cloth passes in at one end, and out at the other finished. It is usually arranged that a continuous current of the various liquors used flows through the various compartments, thus ensuring the most perfect treatment of the cloths. [Illustration: Fig. 28.--Soaping and Washing Machine.] DRYING. (p. 206) Following on the washing comes the final operation of the dyeing process, that of drying the dyed and washed goods. Now textile fabrics of all kinds after they have passed through dye-baths, washing machines, etc., contain a large amount of water, often exceeding in amount that of the fabric itself, and to take the goods direct from the preceding operations to the drying plant means that a considerable amount of fuel must be expended to drive off this large amount of water. It is therefore very desirable that the goods be freed from as much of this water as possible before they are sent into any drying chambers, and this may be done in three ways, by wringing, squeezing and hydro-extracting. The first two methods have already been described (pp. 198, 199) and need not again be alluded to, the last needs some account. [Illustration: Fig. 29.--Hydro-extractor.] Hydro-extractors are a most efficient means for extracting water (p. 207) out of textile fabrics. They are made in a variety of forms by several makers. Essentially they consist of a cylindrical vessel with perforated sides, so constructed that it can be revolved at a high speed. This vessel is enclosed in an outer cage. The goods are placed in the basket, as it is termed, and then this is caused to revolve; at the high speed at which it revolves centrifugal action comes into play and the water contained in the goods finds its way to the outside of the basket through the perforations and so away from the goods. Hydro-extractors are made in a variety of sizes and forms, in some the driving gear is above, in others below the basket, in some the driving is done by belt gearing, in others a steam engine is directly connected with the basket. Figures 29 and 30 show two forms which are much in use in the textile industry. They are very efficient and extract water from textile goods more completely than any other means, as will be obvious from a study of the table below. [Illustration: Fig. 30.--Hydro-extractor.] The relative efficiency of the three systems of extracting the moisture out of textile fabrics has been investigated by Grothe, who gives in his _Appretur der Gewebe_, published in 1882, the following table showing the percentage amount of water removed in fifteen minutes:-- Yarns. Wool. Silk. Cotton. Linen. (p. 208) Wringing 44·5 45·4 45·3 50·3 Squeezing 60·0 71·4 60·0 73·6 Hydro-extracting 83·5 77 81·2 82·8 Pieces. Wringing 33·4 44·5 44·5 54·6 Squeezing 64·0 69·7 72·2 83·0 Hydro-extracting 77·8 75·5 82·3 86·0 In the practical working of hydro-extractors it is of the utmost importance that the goods be carefully and regularly laid in the basket, not too much in one part and too little in another. Any unevenness in this respect at the speed at which they are driven leaves such a strain on the bearings as to seriously endanger the safety of the machine. [Illustration: Fig. 31.--Yarn-drying Machine.] After being wrung, squeezed or hydro-extracted the goods are ready to be dried. In the case of yarns this may be done in rooms heated by steam pipes placed on the floor, the hanks being hung on rods suspended from racks arranged for the purpose. [Illustration: Fig. 32.--Cloth-drying Machine.] Where large quantities of yarn have to be dried it is most economical to employ a yarn or drying machine, and one form of such is shown in figure 31. The appearance of the machine is that of one long room from the outside, internally it is divided into compartments, each of which is heated up by suitably arranged steam pipes, but the degree of heating in each compartment varies, at the entrance end it is (p. 209) high, at the exit end low. The yarn is fed in at one end, being hung on rods, and by suitable gearing it is carried directly through the various chambers or sections, and in its passage the heat to which it is subject drives off the water it contains. The yarn requires no attention from the time it passes in wet at the one end of the (p. 210) machine and comes out dry at the other end. The amount of labour required is slight, only that represented by filling the sticks with wet yarn and emptying the dried yarn. The machine works regularly and well. The drying is accomplished by circulating heated air through the yarns, this heating being effected by steam coils; fresh air continually enters the chambers while water-saturated air is as continually being taken out at the top of the chamber. One of the great secrets in all drying operations is to have a constant current of fresh hot air playing on the goods to be dried, this absorbs the moisture they contain, and the water-charged air thus produced must be taken away as quickly as possible. #Piece Goods.#--The most convenient manner of drying piece goods is to employ the steam cylinder drying machine such as is shown in figure 32. This consists of a number of hollow tin or copper cylinders which can be heated by steam passing in through the axles of the cylinders, which are made hollow on purpose. The cloth to be dried passes round these cylinders, which revolve while the cloth passes. They work very effectually. CHAPTER VIII. (p. 211) EXPERIMENTAL DYEING AND COMPARATIVE DYE TESTING. Every dyer ought to be able to make experiments in the mordanting and dyeing of textile fibres for the purpose of ascertaining the best methods of applying mordants or dye-stuffs, the best methods of obtaining any desired shade, and for the purpose of making comparative tests of dyes or mordanting materials with the object of determining their strength and value. This is not by any means difficult, nor does it involve the use of any expensive apparatus, so that a dyer need not hesitate to set up a small dyeing laboratory for fear of the expense which it might entail. In order to carry out the work indicated above there will be required several pieces of apparatus. First a small chemical balance; one that will carry 50 grammes in each pan is quite large enough, and such a one, quite accurate enough for this work, can be bought for 25s. to 30s., while if the dyer be too poor even for this a cheap pair of apothecaries' scales might be used. It is advisable to procure a set of gramme weights and to get accustomed to them, which is not by any means difficult. In using the balance always put the substance to be weighed on the left-hand pan and the weights on the right-hand pan. Never put chemicals of any kind direct on the pan, but weigh them in a watch-glass, small porcelain basin, or glass beaker (which has first been weighed), according to the nature of the material which is being weighed. The sets of weights are always fitted into a block or (p. 212) box, and every time they are used they should be put back into their proper place. The experimenter will find it convenient to provide himself with a few small porcelain basins, glass beakers, cubic centimetre measures, two or three 200 c.c. flasks with a mark on the neck, a few pipettes of various sizes, 10 c.c., 20 c.c., 25 c.c. The most important feature is the dyeing apparatus. Where only a single dye test is to be made a small copper or enamelled iron saucepan, such as can be bought at any ironmongers may be used; this may conveniently be heated by a gas-boiling burner, such as can also be bought at an ironmongers or plumbers for 2s. [Illustration: Fig. 33.--Experimental Dye-bath.] It is, however, advisable to have means whereby several dyeing experiments can be made at one time and under precisely the same conditions, and this cannot be done by using the simple means noted above. To be able to make perfectly comparative dyeing experiments it is best to use porcelain dye-pots (these may be bought from most dealers in chemical apparatus), and to heat these in a water-bath arrangement. The simplest arrangement is sketched in figure 33; it consists of a copper bath measuring 15 inches long by 10-1/2 inches broad and (p. 213) 6-1/2 inches deep; this is covered by a lid on which are six apertures to take the porcelain dye-baths. The bath is heated by two round gas-boiling burners of the type already referred to. The copper bath is filled with water which, on being heated to the boil by the gas burners, heat up the dye-liquors in the dye-pots. The temperature in the dye-pots under such conditions can never reach the boiling point; where it is desirable, as in some cases of wool mordanting and dyeing that it should be so high, then there should be added to the water in the copper bath a quantity of calcium chloride, which forms a solution that has a much higher boiling point than that of water, and so the dye-liquors in the dye-pots may be heated up to the boil. An objection might be raised that with such an apparatus the temperature in every part of the bath may not be uniform, and so the temperature of the dye-liquors in the pots might vary also, and differences of temperature often have a considerable influence on the shade of the colour which is being dyed. This is a minor objection, which is more academic in its origin than of practical importance. To obviate it Mr. William Marshall, of the Rochdale Technical School, has devised a circular form of dye-bath, in which the temperature in every part can be kept quite uniform. The dyeing laboratories of Technical Schools and Colleges are generally provided with a more elaborate set of dyeing appliances. These in the latest constructed consist of a copper bath supported on a hollow pair of trunnions, so that it can be turned over if needed. Into the bath are firmly fixed three earthenware or porcelain dye-pots; steam for heating can be sent through the trunnions. After the dyeing tests have been made the apparatus can be turned over and the contents of the dye-pots emptied into a sink which is provided for the purpose. Many other pieces of apparatus have been devised and made for the (p. 214) purpose of carrying on dyeing experiments on the small scale, but it will not be needful to describe these in detail. After all no more efficient apparatus can be desired than that described above. Dyeing experiments can be made with either yarns or pieces of cloth, swatches as they are commonly called; a very convenient size is a small skein of yarn or a piece of cloth weighing 5 grammes. These test skeins or pieces ought to be well washed in hot water before use, so that they are clean and free from any size or grease. A little soda or soap will facilitate the cleansing process. In carrying out a dyeing test the dye-pot should be filled with the water required, using as little as is consistent with the dye-swatch being handled comfortably therein, then there is added the required mordants, chemicals, dyes, etc., according to the character of the work which is being done. Of such chemicals as soda, caustic soda, sodium sulphate (Glauber's salt), tartar, bichromate of potash, it will be found convenient to prepare stock solutions of known strength, say 50 grammes per litre, and then by means of a pipette any required quantity can be conveniently added. The same might be followed in the case of dyes which are constantly in use, in this case 5 grammes per litre will be found strong enough. Supposing it is desired to make a test of a sample of Acid Red, using the following proportions, 2 per cent. dye-stuff, 3 per cent. sulphuric acid and 15 per cent. Glauber's salt, and the weight of the swatch which is being used is 5 grammes, the following calculations are to be made to give the quantities of the ingredients required:-- For the dye-stuff, 5 (weight of swatch) multiplied by 2 (per cent. of dye) and divided by 100 equals (5 x 2) / 100 = 0·1 gramme of dye. For the acid we have similarly (5 x 3) / 100 = 0·15 gramme of (p. 215) acid. For the Glauber's salt (5 x 15) / 100 = 0·75 gramme of Glauber's salt. These quantities may be weighed out and added to the dye-bath, or if solutions are kept a calculation can be made as to the number of cubic centimetres which contain the above quantities, and these measured out and added to the dye-bath. When all is ready the bath is heated up, the swatch put in and the work of the test entered upon. Students are recommended to make experiments on such points as:-- The shades obtained by using various proportions of dye-stuffs. The influence of various assistants: common salt, soda, Glauber's salt, borax, phosphate of soda in the bath. The influence of varying proportions of mordants on the shade of dyeing. The value of various assistants, tartar, oxalic acid, lactic acid, sulphuric acid, on the fixation of mordants. The relative value of tannin matters, etc. Each dyer should make himself a pattern book into which he should enter his tests, with full particulars as to how they have been produced at the side. It is important that a dyer should be able to make comparative dye-tests to ascertain the relative strength of any two or more samples of dyes which may be sent to him. This is not difficult but requires considerable care in carrying out the various operations involved. 0·5 gramme of each of the samples of dyes should be weighed out and dissolved in 100 c.c. of water, care being taken that every (p. 216) portion of the dye is dissolved before any of the solution is used in making up the dye-vats. Care should be taken that the skeins of yarn or swatches of cloth are exactly equal in weight, that the same volume of water is placed in each of the dye-pots, that the same amounts of sulphate of soda or other dye assistants are added, that the quantities of dye-stuffs and solutions used are equal, in fact that in all respects the conditions of dyeing are exactly the same, such in fact being the vital conditions in making comparative dye-tests of the actual dyeing strength of several samples of dyes. After the swatches have been dyed they are rinsed and then dried, when the depths of shade dyed on them may be compared one with another. To prevent any mistakes it is well to mark the swatches with one, two, three or more cuts as may be required. It is easier to ascertain if two dyes are different in strength of colour than to ascertain the relative difference between them. There are two plans available for this purpose; one is a dyeing test, the other is a colorimetric test made with the solutions of the dyes. #Dyeing Test.#--This method of ascertaining the relative value of two dyes as regards strength of colour is carried out as follows. A preliminary test will show which sample is stronger than the other; then there is prepared a series of dye-vats, one contains a swatch with the deepest of the two dyes, which is taken as the standard, the others with the other dye but containing 2, 5 and 10 per cent. more dye-stuff, and all these are dyed together, and after drying a comparison can be made between these and the standard swatch, and a judgment formed as to the relative strength of the two dyes; a little experience will soon enable the dyer to form a correct judgment of the difference in strength between two samples of dye-stuff. The colorimetric test is based on the principle that the colour (p. 217) of a solution of dye-stuff is proportionate to its strength. Two white glass tubes, equal in diameter, are taken; solutions of the dye-stuffs, 0·5 gramme in 100 c.c. of water, are prepared, care being taken that the solution is complete. 5 c.c. of one of these solutions is taken and placed in one of the glass tubes, and 5 c.c. of the other solution is placed in the other glass tube, 25 c.c. of water is now added to each tube and then the colour of the diluted liquids is compared by looking through in a good light. That sample which gives the deepest solution is the strongest in colouring power. By diluting the strongest solution with water until it is of the same depth of colour as the weakest, it may be assumed that the length of the columns of liquid in the two tubes is in proportion to the relative strength of the two samples. Thus if in one tube there are 30 centimetres of liquid and in the other 25 centimetres, then the relative strength is as 30 to 25, and if the first is taken as the standard at 100 a proportion sum may be worked out as follows:-- 30: 25 :: 100 : 83·3; that is, the weakest sample has only 83·3 per cent. of the strength of the strongest sample. CHAPTER IX. (p. 218) TESTING OF THE COLOUR OF DYED FABRICS. It is frequently desirable that dyers should be able to ascertain with some degree of accuracy what dyes have been used to dye any particular sample of dyed cloth that has been offered to them to match. In these days of the thousand-and-one different dyes that are known it is by no means an easy thing to do, and when, as is most often the case, two or three dye-stuffs have been used in the production of a shade, the difficulty is materially increased. The only available method is to try the effect of various acid and alkaline reagents on the sample, noting whether any change of colour occurs, and judging accordingly. It would be a good thing for dyers to accustom themselves to test the dyeings they do and so accumulate a fund of practical experience which will stand them in good stead whenever they have occasion to examine a dyed pattern of unknown origin. The limits of this book do not permit of there being given a series of elaborate tables showing the action of various chemical reagents on fabrics dyed with various colours, and such indeed serve very little purpose, for it is most difficult to describe the minor differences which often serve to distinguish one colour from another. Instead of doing so we will point out in some detail the methods of carrying out the various tests, and advise all dyers to carry these out for themselves on samples dyed with known colours, and when they have an unknown colour to test to make tests comparatively with known (p. 219) colours that they think are likely to have been used in the production of the dyed fabric they are testing. One very common method is to spot the fabric, that is to put a drop of the reagent on it, usually with the aid of the stopper of the reagent bottle, and to observe the colour changes, if any, which ensue. This is a very useful test and should not be omitted; and it is often employed in the testing of indigo dyed goods with nitric acid, those of logwood with hydrochloric acid, alizarine with caustic soda, and many others. It is simple and easy to carry out, and only takes a few minutes. To make a complete series of tests of dyed fabrics there should be provided the following reagents:-- 1. Strong sulphuric acid as bought. 2. Dilute sulphuric acid, being the strong acid diluted with 20 times its volume of water. 3. Concentrated hydrochloric acid as bought. 4. Dilute hydrochloric acid, 1 acid to 20 water. 5. Concentrated nitric acid as bought. 6. Dilute nitric acid, 1 acid to 20 water. 7. Acetic acid. 8. Caustic soda solution, 5 grammes in 100 c.c. water. 9. Ammonia (strong). 10. Dilute ammonia, 1 strong ammonia to 10 water. 11. Carbonate of soda solution, 5 grammes in 100 c.c. water. 12. Bleaching powder solution, 2° Tw. 13. Bisulphite of soda, 72° Tw. 14. Stannous chloride, 10 grammes crystals in 100 c.c. water, with a little hydrochloric acid. 15. Methylated spirit. Small swatches of the dyed goods are put in clean porcelain basins, and some of these solutions poured over them. Any change of colour (p. 220) of the fabric is noted as well as whether any colour is imparted to the solutions. After making observations of the effects in the cold, the liquids may be warmed, and the results again noted. After being treated with the acids the swatches should be well washed with water, when the original colour may be wholly or partially restored. To give tables showing the effects of these reagents on the numerous dyes now known would take up too much room and not serve a very useful purpose, as such tables if too much relied on leave the operator somewhat uncertain as to what he has before him. The reader will find in Hurst's _Dictionary of Coal-Tar Colours_ some useful notes as to the action of acids and alkalies on the various colours that may be of service to him. Alizarine and the series of dye-stuffs to which it has given its name, fustic, cochineal, logwood and other dyes of a similar class, require the fabric to be mordanted, and the presence of such mordant is occasionally an indirect proof of the presence of these dyes. To detect these mordants a piece of the swatch should be burnt in a porcelain or platinum crucible over a bunsen burner, care being taken that all carbonaceous matter be burnt off. A white ash will indicate the presence of alumina mordants, red ash that of iron mordants, and a greenish ash chrome mordants. To confirm these the following chemical tests may be applied. Boil the ash left in the crucible with a little strong hydrochloric acid and dilute with water. Pass a current of sulphuretted hydrogen gas through the solution, if there be any tin present a brown precipitate of tin sulphide will be obtained. This can be filtered off. The filtrate is boiled for a short time with nitric acid, and ammonia is added to the solution when alumina is thrown down as a white, gelatinous precipitate, iron is thrown down as a brown red, bulky precipitate, while (p. 221) chrome is thrown down as a greyish-looking, gelatinous precipitate. The precipitate obtained with the ammonia is filtered off and a drop of ammonium sulphide added, when any zinc present will be thrown down as white precipitate of zinc sulphide; to the filtrate from this ammonium oxalate may be added, when if lime is present a white precipitate of calcium oxalate is obtained. A test for iron is to dissolve some of the ash in a little hydrochloric acid and add a few drops of potassium ferrocyanide solution, when if any iron be present a blue precipitate will be obtained. To make more certain of the presence of chrome, heat a little of the ash of the cloth with caustic soda and chlorate of soda in a porcelain crucible until well fused, then dissolve in water, acidify with acetic acid and add lead acetate, a yellow precipitate indicates the presence of chrome. A book on qualitative chemical analysis should be referred to for further details and tests for metallic mordants. The fastness of colours to light, air, rubbing, washing, soaping, acids and alkalies is a feature of some considerable importance, there are indeed few colours that will resist all these influences, and such are fully entitled to be called fast. The degree of fastness varies very considerably, some colours will resist acids and alkalies well, but are not fast to light and air; some will resist washing and soaping, but are not fast to acids; some may be fast to light, but are not so to washing. The following notes will show how to test these features. #Fastness to Light and Air.#--This is simply tested by hanging a piece of the dyed cloth in the air, keeping a piece in a drawer to refer to, so that the influence on the original colour can be noted from time to time. If the piece is left out in the open one gets not only the effect of light but also that of climate on the colour, and there (p. 222) is no doubt rain, hail and snow have some influence on the fading of the colour. If the piece is exposed under glass the climatic influences do not come into play, and one gets the effect of light alone. In making tests of fastness the dyer will and does pay due regard to the character of the influences that the material will be subjected to in actual use, and these vary very considerably; thus the colour of underclothing need not be fast to light, for it is rarely subjected to that agent of destruction; on the other hand, it must be fast to washing, for that is an operation to which underclothing is subjected week by week. Window curtains are much exposed to light and air, and, therefore, the colours in which they are dyed should be fast to light and air. On the other hand, these curtains are rarely washed, and so the colour need not be quite fast to washing. And so with other kinds of fabrics; there are scarcely two kinds which are subjected to the same influences and require the colours to have the same degree of fastness. The fastness to rubbing is generally tested by rubbing the dyed cloth with a piece of white paper. #Fastness to Washing.#--This is generally tested by boiling a swatch of the cloth in a solution of soap containing 4 grammes of a good neutral curd soap per litre for ten minutes, and noting the effect whether the soap solution becomes coloured and to what degree, or whether it remains colourless, and also whether the colour of the swatch has changed at all. One very important point in connection with the soaping tests is whether a colour will run into a white fabric that may be soaped along with it. This is tested by twisting strands of the dyed yarn or cloth with white yarn or cloth and boiling them in the soap liquor for ten minutes and then noting the effect, particularly observing (p. 223) whether the white pieces have taken up any colour. Fastness to acids and fastness to alkalies is observed while carrying out the various acid and alkali tests given above. THE END. INDEX. (p. 225) #A.# Acetate of ammonia, 93, 94, 101, 102, 127, 128, 129, 132, 167, 192, 194. ------- of chrome, 115. ------- of lime, 158, 159. Acetic acid, 127. Acid black, 37, 89. ---- ----- B, 92, 99. ---- ----- B B, 99, 111, 112. ---- ----- S, 90, 99. ---- blue 4 S, 98, 127. ---- ---- 1 V, 153. ---- dyes for blue, 152. ---- ---- for brown, 161. ---- ---- for green, 128. ---- ---- for mode colours, 165. ---- ---- for violet, 160. ---- dye-stuffs, 61. ---- green, 53, 91, 92, 127, 184, 189, 190, 192, 193. ---- ----- B, 128, 191. ---- ----- blue shade, 136. ---- ----- B N, 136. ---- ----- extra, 155. ---- ----- G G, 192. ---- magenta, 73, 105, 111, 113, 183, 190. ---- mauve, 96. ---- ----- B, 161. ---- red, test for, 214. ---- violet, 105. ---- ------ 4 B, 193. ---- ------ 5 B, 154, 160, 189, 191. ---- ------ 5 B E, 162. ---- ------ 6 B, 130, 171, 181. ---- ------ 10 B, 191. ---- ------ N, 92, 99, 161, 162. ---- ------ 6 R N, 161. ---- ------ 4 R S, 160. ---- ------ V, 162. ---- ------ 1 V, 153. ---- yellow, 53, 99, 123, 183, 190. Acids, action on wool, 11. Acridine red, 102. -------- scarlet, 102. Adjective group of dye-stuffs, 68. Alizarine, 61, 69, 72, 73, 86, 114, 220. --------- black, 99. --------- ----- S W, 94, 113. --------- blue, 116, 119, 166. --------- ---- A, 158. --------- ---- D N W, 131, 132, 133, 158, 164, 166. --------- ---- S W, 108. --------- Bordeaux, 133. --------- -------- B, 98, 155. --------- -------- G, 155, 159. --------- brown, 131, 132, 133, 158, 164, 166. --------- claret R, 118. --------- colours, 77. --------- cyanine, 111, 119, 156. --------- ------- black, 93, 94, 159, 160. --------- ------- G, 159. --------- ------- G G, 98, 157. --------- ------- G extra, 157. --------- ------- R, 99, 157. --------- ------- R R, 157. --------- ------- R R R, 93, 157. --------- ------- 3 R double, 157, 160. --------- G, 122. --------- green, 127. --------- ----- S, 132. --------- ----- S W, 132. --------- grey B, 166. --------- orange, 119, 123. --------- ------ 2 G, 120. --------- ------ H, 164. --------- ------ N, 118, 122, 166. --------- ------ W, 119. --------- ------ R, 163. --------- ------ R R, 122. --------- red 1 W S, 118, 119, 120, 122. --------- --- 2 W S, 118. --------- --- 3 W S, 119, 164. --------- --- 5 W S, 118, 120. --------- S X, 120. --------- yellow, 70, 71, 115, 116, 123, 131, 133, 156, 164, 166. --------- ------ G G, 115, 122. --------- ------ G G W, 94, 125, 126, 131, 132, 164. --------- ------ R W, 122. Alkali blue, 152, 189. ------ ---- B, 152. ------ ---- 6 B, 180. ------ yellow R, 169. Alkalies, action on wool, 9. Alkaline blue 6 B, 178. -------- ---- 171, 177. Alpaca, 1, 83. Alum, 74, 77, 85, 86, 97, 115, 117, 129, 131. Alumina, 114. ------- sulphate, 115, 117. Aluminium salts, 8. Amaranth, 92, 108, 111, 192. Amido-benzoic acid, 114. Ammonia, 17, 27, 33, 78. ------- action on wool, 60. Angora goat, 1. Annotta, 13, 63. Anthracene acid black S T, 193. ---------- ---- browns, 115. ---------- blue W B, 159. ---------- ---- W G, 132, 158, 159. ---------- brown, 94, 119, 132. ---------- ----- R, 163. ---------- ----- W, 159, 164. ---------- chrome black, 96, 99. ---------- ------ ----- F, 95. ---------- ------ ----- F F, 92, 96. ---------- red, 122, 134. ---------- yellow, 69, 70, 115. ---------- ------ B N, 96, 126, 135. ---------- ------ C, 90, 98, 109, 122, 124, 125, 126, 132, 163, 167. ---------- ------ G G, 126. Anthracite black B, 90, 96, 132, 163. ---------- ----- R, 90, 98. Anthragallol, 114. Archil, 75, 189. ------ substitute N, 99, 107, 110, 131, 155, 162, 165. Argol, 86, 97, 115, 116, 117, 151. ----- lactic acid, 116. Artificial wool, 174. Auramine, 53, 64, 103, 189. -------- base, 64. -------- I I, 195. Auroline, 169. Azo acid brown, 130. --- ---- magenta G, 162. --- ---- rubine, 111. --- ---- violet 4 R, 109, 111, 161. --- ---- yellow, 171. --- black, 89. --- blue, 171. --- Bordeaux, 109, 191. --- carmine, 124, 161, 166. --- ------- B, 130. --- cochineal, 105, 112, 191. --- crimson L, 196. --- dye-stuffs, 61, 66. --- flavine, 189. --- ------- S, 210. --- fuchsine, 109, 115. --- -------- G, 108, 130, 160, 162, 191, 194, 195, 196. --- green, 70, 127. --- mauve, 171. --- red A, 108, 111, 171, 176, 177, 179, 190, 194. --- rubine, 92. --- scarlet, 53. --- yellow, 93, 124, 128, 129, 130, 155, 162, 165. #B.# Basic dyes for violet, 160. ----- dye-stuffs, 61. Batching of wool, 15, 25. Benzo azurine 3 G, 170. ----- ------- R G, 170. ----- blue black G, 170. ----- brown, 61. ----- dyes, 168. ----- fast red, 100, 102, 110. ----- ---- scarlet, 62. ----- ---- ------- B S, 102. ----- flavine, 64. ----- green, 127. ----- orange R, 121. Benzol, 16, 24. Benzoline, 25. Benzopurpurine, 61, 100. -------------- B, 170. -------------- 4 B, 111, 170, 180, 181. -------------- 10 B, 170, 180. Bichromate of potash, 16, 115, 131, 132, 133, 134, 135, 166, 167, 193. ---------- of potassium, 175. Bisulphate of soda, 33, 131, 141, 146, 167, 184, 192, 193, 194. Bismarck brown, 189, 190. -------- ----- R, 196. Black, 93, 95, 176, 177, 180, 191, 193, 195. ----- and blue, 185, 186. ----- and green blue, 185. ----- and pink, 186. ----- and yellow, 186. ----- blue, 152, 157. ----- ---- O, 155. ----- on wool, 83, 91. Bleaching wool, 29. Blue, 153, 158. ---- and gold yellow, 185. ---- and orange, 187. ---- black, 96, 153, 159, 179, 182, 192. ---- ----- on wool, 89, 90, 91, 92, 94. ---- green, 127, 128, 129, 130. ---- shades on wool, 136. Bluestone, 74, 86, 87, 88, 135. Bluish Bordeaux red, 110. ------ crimson, 108. ------ green, 134. ------ red, 106, 120. ------ pink, 111, 112. ------ purple, 109. ------ violet, 160. ------ rose, 193. Borax, 215. Bordeaux, 102. -------- B L, 110. -------- red, 109, 110, 113. Bottle green, 127, 130, 132, 134. Bran, 138, 144, 145. Brazil wood, 114. Bright blue, 152, 153, 155, 156, 158, 180. ------ Bordeaux red, 109, 110. ------ buff, 164, 165. ------ canary, 124. ------ cherry red, 109, 110. ------ chestnut, 164. ------ crimson, 108. ------ fawn, 165. ------ ---- red, 118. ------ electric blue. 156. ------ golden brown, 163. ------ grass green, 130, 133. ------ green, 127, 128, 134. ------ greenish blue, 154. ------ leaf green, 129. ------ lemon yellow, 125. ------ maroon, 119. ------ moss green, 129. ------ orange, 121, 122. ------ pale sage green, 131. ------ peacock green, 130. ------ red, 111, 193. ------ scarlet, 102, 112. ------ straw, 124. ------ violet, 161. ------ ---- blue, 156. ------ yellow, 123, 124, 175, 176, 178. Brilliant alizarine blue G, 133, 157, 158, 161. --------- azurine 5 G, 170. --------- cochineal 2 R, 112, 123, 193. --------- --------- 4 R, 123, 185. --------- Congo G, 102. --------- ----- R, 170. --------- croceine B, 106, 123. --------- -------- 3 B, 123. --------- -------- 5 B, 123. --------- -------- 7 B, 123. --------- -------- 9 B, 123. --------- -------- B B, 106. --------- -------- M, 106. --------- -------- M O O, 123. --------- -------- N, 189. --------- green, 53, 64, 127, 190, 193, 194. --------- milling green B, 171. --------- orange, 92. --------- orseille C, 107, 112. --------- pale bluish crimson, 108. --------- ponceau G, 106. --------- ------- 2 R, 106. --------- ------- 4 R, 112. --------- purpurine R, 170. --------- rhoduline R B, 195. --------- royal blue, 154. --------- scarlet, 119, 171. --------- ------- G, 171. --------- ------- 4 R, 105. Bronze green, 131, 180. Brown, 161, 163, 164, 181, 192, 195. ----- and violet, 186. ----- and pink, 194. ----- and blue, 185. ----- black, 94. ----- olive and green, 193. Brown shades on wool, 161. Buff, 164. #C.# Calcium salts, 8. Camel-hair, 83. Camwood, 76, 86. Carbohydrate, 7. Carbonate of soda, 27, 78, 169. Carbon disulphide, 16, 24. Carbonising of wool, 11. Carded wool, dyeing of, 44. Carmoisin, 189. --------- B, 191. Cashmere, 83, 173. -------- goat, 1. Caustic soda, 141. ------- lye, 147. Celestine blue B, 155. Chemical vats, 138. Chemic extract, 150. Cherry red, 109, 110. Chestnut, 163. -------- brown, 184. Chicago blue B, 170. ------- ---- 4 B, 170. ------- ---- 6 B, 170, 180. ------- ---- G, 170. ------- ---- R W, 181. ------- ---- R R W, 170. Chloramine orange, 121. ---------- yellow, 169. Chlorination of wool, 37. Chlorine, action on wool, 12. Cholesterine, 7, 23. Chrome, 114. ------ acetate, 129. ------ alum, 115. ------ blue, 158. ------ Bordeaux 6 B, 161. ------ brown R, 164. ------ fluoride, 77. ------ logwood black, 84, 85. ------ ------- jet black, 85. ------ mordant, 151. ------ patent black D G, 92. ------ violet, 115, 119. Chromine G, 169. Chromogene I, 120. Chromotrop, 115. ---------- 2 B, 125. ---------- 6 B, 108, 154. ---------- 10 B, 94, 109. ---------- R, 106. ---------- 2 R, 99, 107, 129, 130, 155, 162, 165. ---------- S, 93, 94. Chrysamine, 61, 128, 170. ---------- G, 165. Chrysoidine, 184. Chrysophenine, 61, 102, 128, 170. ------------- G, 180. Claret, 110, 111, 118, 120. ------ red, 110. Clayton yellow, 170. Cloth-drying machine, 209. ------------ red, 73. ------------ washing machine, 29, 30, 202, 203. Coal tar, 137. ---- --- colours, 114. ---- --- dyes, 63. ---- --- ---- for dyeing blue, 152. Coatings, 173. Cochineal, 97, 114, 190, 220. --------- scarlet, 77. Coerulein, 114, 133. --------- B, 132. --------- S W, 132. --------- blue, 192. Colour lakes, 113. ------ strength, test for, 216. ------ testing, 218. Columbia black B, 170. -------- ----- F B, 170, 181. -------- red 8 B, 170. -------- yellow, 169. Congo blue, 62. ----- brown G, 170, 180. ----- ----- R, 161, 171. ----- Corinth G, 171, 180, 187. ----- ------- B, 169, 171. ----- dyes, 168. ----- orange G, 170. ----- ------ R, 165, 170. ----- R, 170. ----- red, 62. Copperas, 74, 86, 87, 88, 97, 133, 134, 135. -------- vats, 138. Copper-cased dye beck, 56. Coral red, 112. Cornflower blue, 181. Corron's hank-dyeing machine, 49. Cotton yellow, 170. Cream of tartar, 116. Crimson, 103, 108, 113, 180, 183, 191, 194. Croceine A Z, 123, 171, 189, 191, 192. -------- orange, 121, 122, 189. -------- ------ E N, 123. -------- scarlet, 108. -------- ------- 3 B, 191. -------- ------- 3 R, 167. Cross dyeing, 183. Crushed strawberry, 105. ------- ---------- red, 107, 118. Crystal scarlet 6 R, 123. Cudbear, 97. Curcumine extra, 171, 181, 187. --------- S, 180, 186. Cutch, 76, 97. ----- brown, 76. Cyanine B, 107, 111, 124, 129, 130, 155, 165. ------- scarlet R, 111. Cyanole, 107, 111, 131, 165. ------- extra, 99, 108, 112, 113, 131, 155, 184, 185, 186. ------- green B, 134. ------- ----- 6 G, 134. Cyprus green B, 136. ------ ----- R, 136. #D.# Dark beige green, 130. ---- blue, 152, 154, 157, 159, 176, 178, 179, 180, 181, 182, 195. ---- Bordeaux red, 120. ---- bottle green, 131, 132. ---- brown and blue, 185. ---- ----- 163, 164, 177, 179, 180, 181, 182. ---- buff, 165. ---- chestnut, 162. ---- cherry red, 112. ---- crimson, 102, 195. ---- green, 127, 128, 131, 177, 180, 183. ---- ----- and pale crimson, 194. ---- grey, 98, 166, 167, 178, 181, 192. ---- invisible blue, 156. ---- maroon, 193. ---- navy, 157, 159. ---- ---- blue, 155. ---- olive brown, 162. ---- orange, 121. ---- peacock blue, 156. ---- red, 120. ---- sage, 179. ---- ---- green, 130. ---- sea green, 171. ---- seal, 162, 163. ---- slate, 159, 166, 177. ---- stone, 177. ---- violet, 161. ---- ------ brown, 164. ---- walnut, 164, 179. Dead black on wool, 90. Deep blue, 154, 155. ---- Bordeaux red, 109. ---- brown, 162. ---- crimson, 108, 112, 113, 118. ---- electric green, 131. ---- fawn, 107. ---- ---- red, 107, 119. ---- golden yellow, 125. ---- indigo blue, 192. ---- leaf green, 130. ---- ---- yellow, 125. ---- lemon, 125. ---- maroon, 111, 119, 191. ---- navy, 153. ---- ---- blue, 153. ---- olive yellow, 125. ---- orange, 122, 176. ---- red, 103. ---- sage green, 131, 132. ---- scarlet, 106, 112, 119. ---- seal, 162. ---- sky blue, 155. ---- violet, 160. ---- ------ brown, 192. ---- yellow, 124, 126. Delahunty's dyeing machine, 43, 44. Deltapurpurine 5 B, 130. Diamine black, 99, 155. ------- ----- B H, 170, 177, 178. ------- ----- B O, 170. ------- ----- H W, 169, 177, 178. ------- ----- R O, 170. ------- blue, 62. ------- ---- 2 B, 170. ------- ---- 3 B, 170. ------- ---- B G, 170. ------- ---- B X, 170. ------- ---- G, 169. ------- ---- R W, 169, 170. ------- ---- 3 R, 170. ------- ---- black E, 170. ------- Bordeaux, 102. ------- -------- B, 169, 170, 177, 179. ------- -------- S, 170. ------- brilliant blue G, 170, 176, 178, 179. ------- bronze G, 171, 177. ------- brown, 62, 179. ------- ----- B, 169. ------- ----- G, 170. ------- ----- 3 G, 169. ------- ----- G W, 169. ------- ----- N, 169, 177. ------- ----- S, 170. ------- ----- V, 170, 177. ------- catechine B, 170, 179. ------- --------- G, 169, 170. ------- cutch, 176. ------- dark blue B, 169, 170, 180. ------- dyes, 168. ------- fast yellow A, 170, 175, 186. ------- ---- ------ B, 169, 176, 177, 179. ------- ---- red F, 98, 100, 102, 109, 112, 124, 132, 163, 167, 169. ------- gold, 121, 170, 175. ------- green, 127. ------- ----- B, 169. ------- ----- G, 169, 170. ------- new blue R, 170. ------- nitrazol brown B, 170. ------- -------- G, 170. ------- orange B, 169, 177, 178, 179. ------- ------ D, 170. ------- ------ D C, 121. ------- ------ G, 170, 175, 178, 184, 185. ------- ------ G C, 121. ------- ------ O, 170. ------- red, 62, 169. ------- --- B, 170. ------- --- 5 B, 178. ------- --- N O, 170. ------- rose B D, 102, 169, 178, 186. ------- scarlet B, 112, 121, 122, 170, 178. ------- ------- 3 B, 170. ------- sky blue, 170, 185. ------- --- ---- F F, 170, 185, 186. ------- steel blue L, 170, 177, 185. ------- violet N, 170, 178, 186. Diamond black, 93, 99. ------- ----- F, 92. ------- ----- on wool, 93. ------- brown, 164. ------- flavine, 133, 163. ------- ------- G, 98. ------- green, 93. ------- yellow B, 133. Dihydroxynaphthalene, 88. --------- sulpho acid, 116. Dinitroso-resorcine, 127. Direct black, 88. ------ dyes, 197. ------ ---- for blue, 152. ------ ---- for brown, 161. ------ ---- for green, 127. ------ ---- for mode colours, 165. ------ ---- for orange, 121. ------ ---- for violet, 160. ------ orange R, 170. ------ red dyes, 100. ------ yellow G, 170. Divi-divi, 197. Drab, 165, 166, 167, 178, 179, 181, 182, 194. Dress goods, 173. Drying of goods, 205. Dyeing machinery, 40, 43. ------ test, 216. ------ tubs, 41. Dye-jiggers, 51, 52. ----------- tests, 211. ----------- vat with steam pipe, 42. #E.# Electric blue, 155. Emerald green, 128, 129, 130, 135. Emin red, 107, 110. Eosine, 190. ------ red, 104. Erie blue, 2 G, 170. Erika B N, 170, 187. Erythesine D, 112. Erythrosine, 104, 190. Experimental dye-bath, 212. ------------ dyeing, 211. #F.# Fast acid violet 10 B, 111, 130, 162, 165, 189. ---- ---- ------ R, 108, 110, 111, 112, 113, 120, 130, 166. ---- ---- blue R, 99, 107, 129, 155, 165. ---- ---- green B N, 96, 134, 185. ---- ---- magenta B, 105, 108, 109, 153. ---- black, 96. ---- blue, 37. ---- bright olive, 135. ---- chrome black, 92. ---- green, 127, 133. ---- green bluish, 111, 130, 154, 160, 162, 165, 189, 192, 194, 195. ---- ----- extra bluish, 162. ---- light green, 195. ---- red, 102, 111. ---- scarlet, 105. ---- yellow, 109, 124, 161, 162, 165, 166, 194. ---- ------ F Y, 90, 91, 105, 123, 130. ---- ------ S, 111, 113, 135, 186, 193. ---- ------ extra, 194, 195. Fastness to acid, test for, 223. -------- to alkalies, test for, 223. -------- to light and air, test for, 221. -------- to washing, test for, 222. Fawn, 118. ---- drab, 179. ---- red, 107, 113. Ferrous sulphate, 115, 117. Fermentation vats, 138. Flavazol, 70. Fluoride of chrome, 91, 98, 102, 110, 115, 117, 129, 132, 133, 167. Formyl blue B, 171. ------ violet, 53. ------ ------ 6 B, 171. ------ ------ 10 B, 171. ------ ------ S 4 B, 155, 161, 171, 175, 176, 178, 179, 180, 185, 189, 190, 191. Fulling fast olive, 135. Fustic, 66, 69, 70, 77, 83, 85, 86, 87, 97, 120, 220. ------ extract, 88, 123, 131, 133, 134, 135. #G.# Galleine, 166. Gallipoli oil, 26. Galloflavine, 70, 119, 133. Gambine, 61, 114, 119, 127. ------- B, 164. ------- R, 133, 164, 167. ------- V, 96, 125, 133, 164. ------- yellow, 93, 115, 125. Geranine B, 160. -------- G, 102. Glacier blue, 155. Glauber's salt, 81, 89, 91, 99, 127, 128, 129, 130, 135, 150, 151, 169, 171, 172, 184, 215. Gloria, dyeing of, 188. Gold and green, 184. ---- brown, 176, 179, 185. ---- orange, 122, 123, 176. ---- yellow, 126. Golden brown, 162, 163. ------ yellow, 125, 126. Good yellow, 175. Grass green, 128. Green, 127, 131, 178, 192, 193, 195. ----- and buff, 186. ----- and claret, 185. ----- and red, 186. ----- and orange, 187. Greenish, 98. -------- black on wool, 91. -------- straw, 124. Grey, 98, 165, 182. ---- and orange, 186. ---- blue, 158. ---- on wool, 96. Guinea green B, 171, 181, 187. ------ violet 4 B, 171, 181. #H.# Hæmatoxylin of logwood, 84. Hand dyeing, 40. ---- scouring of wool, 18. Hank-washing machine, 201. ---- wringing machines, 198. Hare fur, 83. Hessian violet, 102, 171. Holliday's patent indigo vat, 143. Hydrochloric acid, 88. Hydrochloride of rosaniline, 9. Hypochlorites, action on wool, 12. Hydro-extractor, 206, 207. Hydrosulphite of soda, 147. ------------- vats, 138, 141. Hydroxy-azo dyes, 114. #I.# Imperial green G 1, 195. Indian yellow, 90, 91, 189, 191, 192. ------ ------ G, 131, 171, 175, 176, 177, 179, 180, 185, 195. ------ ------ R, 126, 165, 171, 175, 176, 195. Indigo, 83, 85, 136, 141. ------ black, 86. ------ blue, 151. ------ carmine, 66, 150. ------ carmine D, 161, 166. ------ dyeing, 137. ------ dye-stuffs, 61. ------ dye-vat, 149. ------ extract, 73, 75, 97, 105, 131, 133, 134, 135, 151, 190, 194. ------ ------- for dyeing wool, 150. ------ indophenol vat, 146. Indigotine, 194. ---------- extra, 193, 195, 196. Indophenol, 146. Induline, 37. -------- A, 153. Invisible bronze green, 133. --------- green, 130, 132, 136. Iron logwood black, 86, 87. Italian cloths, 176. #J.# Janus black I, 182. ----- ----- I I, 182. ----- blue R, 182. ----- brown B, 182. ----- ----- R, 182, 183. ----- claret red B, 183. ----- dark blue B, 182. ----- dyes, 181. ----- green B, 182, 183. ----- grey B, 182, 183. ----- ---- B B, 182. ----- red B, 182, 183. ----- yellow G, 182. ----- ------ R, 182, 183. Jet black, 93, 94, 95, 96. --- ----- on wool, 90, 91, 93. Jig wince, 53. #K.# "Kempy" fibres, 3. Keratine, 8. Keton blue G, 111, 162. Klauder-Weldon hank-dyeing machine, 47, 48. #L.# Lactic acid, 115, 116, 117, 151, 215. Lanafuchsine 6 B, 113. ------------ S B, 111, 113. ------------ S G, 111, 112, 113. Lanacyl blue B B, 171. ------- ---- R, 171. ------- violet B, 171, 180. Lavender, 160, 196. -------- blue, 158. -------- grey, 166. Leaf yellow, 125. Lemon yellow, 125. Level dyeing, 77. Light drab, 196. ----- green, 133, 195. ----- grey, 97, 193. ----- sea green, 195. ----- straw, 126. Lignorosine, 115, 117, 151. Lilac, 166. ----- blue, 158. ----- grey, 165. Lime, 117, 140. ---- vats, 138. Liquor ammonia, 147. Llama, 1. Logwood, 66, 69, 70, 83, 85, 86, 87, 97, 136, 151, 220. ------- black, 87, 88. ------- ----- on wool, 86. ------- extract, 88, 133, 135, 136. Loose wool, dyeing of, 43. ----- ---- washing of, 200. #M.# Machine-scouring of wool, 20. Madder, 77, 144. Magenta, 53, 61, 64, 102, 103, 190. Maize yellow, 124. Malachite green, 127. Mandarine G, 121, 171, 180, 181, 187. Maroon, 111, 118, 178. ------ red, 111. Marseilles soap, 78. Mauve, 161. McNaught's wool-washing machine, 20. Metallic salts, action on wool, 12. Methylene blue, 133, 134. Methylrosaniline, 64. Methyl violet, 53, 64, 190. ------ ------ 3 B, 160. ------ ------ B O, 192. ------ ------ R, 160. Medulla, 4. Medium blue, 157, 158. ------ green, 133. Merino wool, 5. Mikado orange 4 R O, 180, 181, 187. Milling red B, 111. ------- --- R, 106, 110. ------- yellow, 192. ------- ------ O, 99, 125, 193. Mimosa, 169. Mode colours on wool, 164. Mordant dyes for brown, 163. ------- ---- for orange, 122. ------- dye-stuffs, 61, 68. ------- dyes for violet, 161. Mordanting, 115. ---------- of wool, 12. Mordant yellow, 119, 122, 132. ------- ------ D, 126. ------- ------ O, 164. Moss green, 129, 130. Mother vat, 147. Mouse, 162. Muriate of tin, 97. Myrobalan, 197. #N.# Naphthol black, 37, 89, 99, 186. -------- ----- B, 90. -------- ----- B B, 196. -------- ----- 3 B, 90, 91, 185, 192. -------- ----- 4 R, 111. -------- blue G, 171, 185. -------- ---- R, 171. -------- ---- black, 155, 171, 175, 177, 178, 179, 180, 185. -------- green B, 37, 90, 127, 128, 189, 192, 193, 194. -------- red C, 113, 185, 192. -------- --- O, 193. -------- yellow, 131, 136, 190. -------- ------ S, 113, 130, 178. Naphthyl blue black N, 92. Naphthylamine black, 89, 92, 189. ------------- ----- 4 B, 91, 171, 192. ------------- ----- 6 B, 171, 180. ------------- ----- D, 91, 99, 171, 191. ------------- ----- S, 96. Navy, 158. ---- blue, 153, 136, 177, 179, 180. Neutral dye-stuffs, 61. ------- extract, 150. ------- red, 162. New methylene blue, 190. --- --------- ---- N, 185, 194. --- Victoria black blue, 190. --- -------- blue B, 154. --- -------- ---- black, 192. Nigrosine, 37. Nitrate of iron, 98. Nitrazine yellow, 124. Nut, 164. --- brown, 181, 182. Nyanza black, 95. ------ ----- B, 99, 128, 161, 165. #O.# Obermaier dyeing machine, 44, 45, 46. Old gold, 122, 126. Oleic acid, 7, 26. Oleine, 26. Olive, 128, 134, 135. ----- brown, 162, 164. ----- bronze, 135. ----- green, 128, 135. ----- oil, 26. ----- yellow, 124, 125. Orange, 121, 122, 178, 180, 191, 192, 195. ------ No. 2, 162. ------ blue, 187, 194. ------ green, 194. ------ violet, 186. ------ croceine G, 189. ------ E N Z, 123, 135, 171, 176, 178, 179, 180, 185. ------ extra, 99, 107, 108, 111, 113, 122, 162, 163, 171, 178. ------ G, 99, 107, 110, 113, 162, 165, 166, 190. ------ G G, 112, 113, 122, 162, 184, 185, 190, 191, 193. ------ I I, 153, 162. ------ O, 111. ------ R, 122, 189. ------ shades on wool, 121. ------ T A, 170, 181. Oxalate of ammonia, 95. Oxalic acid, 85, 87, 88, 93, 115, 116, 133, 151, 215. Oxydiamine black A, 169. ---------- ----- B, 169. ---------- ----- B M, 180. ---------- ----- D, 169. ---------- ----- M, 169. ---------- ----- S O O O, 170. ---------- Orange G, 170, 178. ---------- ------ R, 170. ---------- red S, 170. ---------- violet B, 170. ---------- yellow G G, 170. Oxyphenine, 169. #P.# Pale blue, 152, 155, 193, 195. ---- bluish crimson, 108. ---- chestnut, 164. ---- crimson, 108. ---- drab, 165, 166. ---- fawn, 166. ---- ---- drab, 165. ---- ---- brown, 166. ---- gold yellow, 175. ---- green, 192. ---- lilac rose, 107. ---- maroon, 191. ---- navy blue, 156. ---- old gold brown, 164. ---- olive yellow, 126. ---- orange, 121, 122. ---- pea-green, 131. ---- Russian green, 128. ---- sage, 195. ---- ---- green, 130, 133, 180. ---- sea green, 129, 132. ---- slate green, 133. ---- ----- grey, 98. ---- stone, 166. ---- violet, 160. Pararosaniline, 64. Paris blue, 158. Patent blue, 92, 99. ------ ---- A, 131, 158. ------ ---- B, 95, 110, 154. ------ ---- J, 154, 162. ------ ---- J B, 166. ------ ---- J O O, 166. ------ ---- N, 128, 154. ------ ---- V, 111, 129, 130, 154, 155, 162, 168. ------ ---- superior, 154. Peach wood, 86. Peacock blue, 155, 157, 158. ------- green, 131, 132, 177, 179. Pearl ash, 17. ----- grey, 97, 98. Perchloride of tin, 97. Peri wool blue, 155. Peroxide of hydrogen for bleaching wool, 29, 34. -------- of soda for bleaching wool, 36. Persian berries, 69, 71. Petrie's wool-washing machine, 20. Petroleum spirit, 16, 24. Phenoflavine, 124, 130. Phenolic colours, 114. Phenyl rosaniline, 64. Phloxine, 104, 190, 191. Phosphate of soda, 218. Picric acid, 190. Piece-dyeing machines, 50. ----- goods, drying of, 210. ----- ---- washing of, 202. ----- ---- wringing of, 199. Pink, 102, 111, 112, 178, 195. Plum, 178. Plush fabric dyeing machine, 55. Ponceau, 105. ------- 3 G, 121. ------- R, 65. ------- 3 R B, 171, 180. Potash, 17. ------ indigo vat, 144. ------ salts, 7. Potassium salts, 8. Primuline, 169. Puce, 160. Pure blue O T, 193. Purple, 109. ------ red, 113. Purpuramine, 62. #Q.# Quick lime, 141. Quinoline yellow, 189, 194. #R.# Rabbit fur, 83. Raw merino wool, analysis of, 7. Read Holliday's hawking machine, 57. ---- -------- indigo extract, 151. ---- -------- squeezing machine, 199. ---- -------- yarn dyeing machine, 46, 47. Red, 106, 107, 120. --- navy, 158. --- ---- blue, 157. --- plum, 177. --- shades on wool, 100. Reddish black, 94. ------- grey, 97. ------- orange, 121. ------- puce, 160. Rhodamine, 165, 189, 190. --------- B, 113, 191, 193, 197. --------- G, 195. --------- red, 102. Rhoduline red, 102, 103. Rocceleine, 171, 190. Roller-squeezing machine, 198. Rose, 118. Rosaniline, 64. Rose bengale, 104, 112, 189, 190. ---- red, 113. Royal blue, 154. #S.# Saddening of wool, 74. Saffranine, 61, 64, 102, 103, 184, 189, 190. ---------- prima, 103, 194. Saffron, 13, 63. Saffrosine, 104. Sage, 177. ---- brown, 181. ---- green, 128. Salicylic acid, 114. Salmon, 113. ------ red, 113. Salt, 215. Sanders, 120, 121. Saxony blue, 154. Scarlet, 101, 102, 103, 105, 106, 107, 112, 118, 178, 180, 191. ------- F R, 106. ------- O O, 106. ------- R, 183. ------- 3 R, 191. ------- 2 R J, 105. ------- R S, 105. ------- S, 190. Schutzenberger and Lalande's vat, 141. Schweizer's reagent, 9. Scouring of wool, 15, 17. -------- of woollen piece goods, 28. Sea green, 131, 136. Serge, 173. Silicate of soda, 17. Silk blue, 189. ---- ---- B E S, 192. Silver grey, 98, 165, 177. Sheep, 1. Short-stapled wools, scouring of, 18. Shot effects, 183. Sky blue, 151, 154, 178, 194. Slaked lime, 145. Slate, 165, 181. ----- blue, 158, 179. ----- green, 131, 132, 181. ----- grey, 97, 98. Sliver, dyeing of, 44. Slubbing, dyeing of, 44. Smithson's dyeing machine, 88. Soap, 27. ---- action on wool, 10, 66. Soaping and washing machine, 205. ------- of goods, 204. Soda, 17, 215. ---- ash, 17. ---- crystals, 145. ---- indigo vat, 145. Sodium hydrosulphite, 143. Solid blue, 190. ----- ---- R, 192. ----- ---- P G, 192. ----- green crystals, 194. Soluble blue, 189. Sour extract, 150. Southdown wool, 5. Spencer's hank-wringing machine, 198. Squeezing of goods, 197. Stale urine, 17, 18. Stearic acid, 7. Stone, 166, 181. Straw, 124. Stuffing of wool, 74. Suint, 15. Suitings, 173. Sulphon azurine B, 170. ------- ------- D, 180. ------- cyanine, 128, 152, 160. Sulphur, 8. ------- bleach house, 31. ------- dioxide, 33. ------- bleaching, 29, 30. Sulphuric acid, 99, 115, 116, 215. Sumac, 86, 120, 121, 135, 197. ----- extract, 182, 183. Sweet extract, 150. #T.# Tannic acid, 98. Tannin materials, 197, 215. Tartar, 85, 86, 88, 93, 115, 116, 117, 131, 132, 133, 134, 135, 151, 166, 167, 215. ------ emetic, 182, 183. Tartaric acid, 85, 115. Tartrazine, 190. Terra-cotta, 195. ----- ----- red, 105, 120. Tin chloride, 115. --- crystals, 77. --- salt, 133. Thiazol yellow, 169. Thiocarmine R, 98, 171, 177, 179, 189, 190. Thioflavine S, 121, 169, 175, 178, 185, 186. ----------- T, 64, 190, 193, 194. Titan blue, 170, 171. ----- ---- 3 B, 127. ----- brown O, 110, 170. ----- ----- R, 98, 170. ----- ----- T, 170. ----- marine B, 171. ----- pink, 170. ----- red, 61, 98, 107. ----- scarlet, 100. ----- ------- C B, 101, 102. ----- ------- D, 110. ----- ------- S, 169. ----- yellow, 61, 99, 170. ----- ------ G, 127. ----- ------ R, 125. ----- ------ Y, 125, 127. Treacle, 138. Tropæoline, 122, 131. ---------- O, 190. ---------- O O, 171, 178. Turmeric, 13, 63, 120, 189. Turquoise blue B B, 195. --------- ---- G, 196. --------- green, 134. #U.# Union black B, 169. ----- ----- S, 169, 176, 178, 179, 180. ----- blue B B, 169. ----- fabrics, dyeing of, 168. ----- flannels, 173. Urine indigo vat, 145. #V.# Velvet, embossing of, 14. Victoria black, 89, 189. -------- black B, 91, 191. -------- ---- blue, 155. -------- blue, 189. -------- ---- B, 155. -------- ---- black, 91. -------- scarlet R, 107, 110, 111. -------- rubine O, 107, 111. -------- violet 8 B S, 130, 155. -------- yellow, 111, 124, 130, 162. Violet, 160, 192, 193. ------ and pink, 193, 194. ------ black on wool, 89, 90, 91, 93, 95. ------ blue, 155. ------ grey, 166. ------ shades on wool, 160. #W.# Walnut, 162. ------ brown, 176, 182. Washing of goods, 200. Water blue, 37. White indigo, 138. Wince dye beck, 53, 54. Woad, 138. ---- indigo vats, 139. ---- vat, 145. Woaded black, 86. Wool, 1. ---- action of acid on, 11. ---- alkalies, action of on, 9. ---- batching, 15. ---- black, 89. ---- ----- 6 B, 171, 180, 181, 186. ---- bleaching, 29. ---- --------- peroxide of hydrogen, 34. ---- --------- -------- of soda, 36. ---- --------- with sulphur, 30. ---- chemical composition of, 6. ---- chlorination of, 37. ---- blue B X, 153. ---- ---- dyeing with logwood, 161. ---- fibre under microscope, 2. ---- ----- unscoured, 10. ---- ----- chemical composition of, 7. ---- ----- scoured badly, 10. ---- ----- showing medullary centre, 4. ---- ----- heated with acid, 11. ---- grey R, 166. Woollen piece goods, scouring of, 28. ------- yarn, 2. Wool oil, 26. ---- physical properties of, 2. ---- -------- structure, variations in, 5. Wool scouring, 15, 17. ---- -------- by solvents, 23. Wool-washing machine, 20, 21. Worsted yarn, 2. Wringing of goods, 197. #Y.# Yarn-drying machine, 208. Yarn, washing of, in hanks, 202. Yarn wringing, 198. Yellow, 125, 195. ------ brown, 161. ------ N, 125, 133, 134. ------ olive, 135. ------ shades on wool, 123. Yolk, 7. Yorkshire grease, 26. #Z.# Zambesi black B, 170, 181. ------- ----- D, 170, 180, 181. ------- ----- F, 171. ------- blue R A, 180, 181. ------- brown G, 171, 181. ------- ----- 2 G, 171. ------- dyes, 168. Zinc dust, 141. The Aberdeen University Press Limited. CATALOGUE (p. c01) Of _Special Technical Books_ For Manufacturers, Technical Students And Workers, Schools, Colleges, Etc. By Expert Writers Index To Subjects. Page Agricultural Chemistry........... 10 Air, Industrial Use of........... 12 Alum and its Sulphates............ 9 Ammonia........................... 9 Aniline Colours................... 3 Animal Fats....................... 6 Anti-corrosive Paints............. 4 Architecture, Terms in........... 30 Architectural Pottery............ 15 Artificial Perfumes............... 7 Balsams.......................... 10 Bibliography..................... 32 Bleaching........................ 23 Bone Products..................... 8 Bookbinding...................... 31 Brick-making................. 15, 16 Burnishing Brass................. 28 Carpet Yarn Printing............. 21 Ceramic Books................ 14, 15 Charcoal.......................... 8 Chemical Essays................... 9 Chemistry of Pottery............. 16 Chemistry of Dye-stuffs.......... 23 Clay Analysis.................... 16 Coal-dust Firing................. 26 Colour Matching.................. 22 Colliery Recovery Work........... 25 Colour-mixing for Dyers.......... 22 Colour Theory.................... 22 Combing Machines................. 24 Compounding Oils.................. 6 Condensing Apparatus............. 26 Cosmetics......................... 8 Cotton Dyeing.................... 23 Cotton Spinning.................. 24 Damask Weaving................... 20 Dampness in Buildings............ 30 Decorators' Books................ 28 Decorative Textiles.............. 20 Dental Metallurgy................ 25 Dictionary of Paint Materials..... 2 Drying Oils....................... 5 Drying with Air.................. 12 Dyeing Marble.................... 31 Dyeing Woollen Fabrics........... 23 Dyers' Materials................. 22 Dye-stuffs....................... 23 Enamelling Metal................. 18 Enamels.......................... 18 Engraving........................ 31 Essential Oils.................... 7 Evaporating Apparatus............ 26 External Plumbing................ 27 Fats........................... 5, 6 Faults in Woollen Goods.......... 21 Gas Firing....................... 26 Glass-making Recipes............. 16 Glass Painting................... 17 Glue Making and Testing........... 8 Greases........................... 5 Hat Manufacturing................ 20 History of Staffs Potteries...... 16 Hops............................. 28 Hot-water Supply................. 28 How to make a Woollen Mill Pay... 21 India-rubber..................... 13 Industrial Alcohol............... 10 Inks.......................... 3, 11 Iron-corrosion.................... 4 Iron, Science of................. 26 Japanning........................ 28 Lace-Making...................... 20 Lacquering....................... 28 Lake Pigments..................... 2 Lead and its Compounds........... 11 Leather Industry................. 13 Leather-working Materials........ 14 Lithography...................... 31 Lubricants..................... 5, 6 Manures....................... 8, 10 Mineral Pigments.................. 3 Mine Ventilation................. 25 Mine Haulage..................... 25 Oil and Colour Recipes............ 3 Oil Boiling....................... 5 Oil Merchants' Manual............. 7 Oils.............................. 5 Ozone, Industrial Use of......... 12 Paint Manufacture................. 2 Paint Materials................... 3 Paint-material Testing............ 4 Paper-pulp Dyeing................ 17 Petroleum......................... 6 Pigments, Chemistry of............ 2 Plumbers' Work................... 27 Porcelain Painting............... 17 Pottery Clays.................... 16 Pottery Manufacture.............. 14 Power-loom Weaving............... 19 Preserved Foods.................. 30 Printers' Ready Reckoner......... 31 Printing Inks..................... 3 Recipes for Oilmen, etc........... 3 Resins........................... 10 Risks of Occupations............. 11 Riveting China, etc.............. 16 Sanitary Plumbing................ 27 Sealing Waxes.................... 11 Silk Dyeing...................... 22 Silk Throwing.................... 18 Smoke Prevention................. 26 Soaps............................. 7 Spinning......................... 21 Staining Marble, and Bone........ 31 Steam Drying..................... 12 Sugar Refining................... 32 Steel Hardening.................. 26 Sweetmeats....................... 30 Terra-cotta...................... 15 Testing Paint Materials........... 4 Testing Yarns.................... 20 Textile Fabrics.................. 20 Textile Materials............ 19, 20 Timber........................... 29 Varnishes......................... 5 Vegetable Fats.................... 7 Waste Utilisation................ 10 Water, Industrial Use............ 12 Waterproofing Fabrics............ 21 Weaving Calculations............. 21 Wood Waste Utilisation........... 29 Wood Dyeing...................... 31 Wool Dyeing.................. 22, 23 Writing Inks..................... 11 X-Ray Work....................... 13 Yarn Testing..................... 20 Published By Scott, Greenwood & Son, 8 Broadway, Ludgate Hill, London, E.c. Telegraphic Address, "Printeries, London". #PAINTS, COLOURS AND PRINTING INKS.# (p. c02) #THE CHEMISTRY OF PIGMENTS.# By Ernest J. PARRY, B.Sc. (Lond.), F.I.C., F.C.S., and J. H. COSTE, F.I.C., F.C.S. Demy 8vo. Five Illustrations. 285 pp. Price 10s. 6d. net. (Post free, 10s. 10d. home; 11s. 3d. abroad.) #Contents.# #Introductory.# Light -- White Light -- The Spectrum -- The Invisible Spectrum -- Normal Spectrum -- Simple Nature of Pure Spectral Colour -- The Recomposition of White Light -- Primary and Complementary Colours -- Coloured Bodies -- Absorption Spectra -- #The Application of Pigments.# Uses of Pigments: Artistic, Decorative, Protective -- Methods of Application of Pigments: Pastels and Crayons, Water Colour, Tempera Painting, Fresco, Encaustic Painting, Oil-colour Painting, Keramic Art, Enamel, Stained and Painted Glass, Mosaic -- #Inorganic Pigments.# White Lead -- Zinc White -- Enamel White -- Whitening -- Red Lead -- Litharge -- Vermilion -- Royal Scarle t-- The Chromium Greens -- Chromates of Lead, Zinc, Silver and Mercury -- Brunswick Green -- The Ochres -- Indian Red -- Venetian Red -- Siennas and Umbers -- Light Red -- Cappagh Brown -- Red Oxides -- Mars Colours -- Terre Verte -- Prussian Brown -- Cobalt Colours -- Coeruleum -- Smalt -- Copper Pigments -- Malachite -- Bremen Green -- Scheele's Green -- Emerald Green -- Verdigris -- Brunswick Green -- Non-arsenical Greens -- Copper Blues -- Ultramarine -- Carbon Pigments -- Ivory Black -- Lamp Black -- Bistre -- Naples Yellow -- Arsenic Sulphides: Orpiment, Realgar -- Cadmium Yellow -- Vandyck Brown -- #Organic Pigments.# Prussian Blue -- Natural Lakes -- Cochineal -- Carmine -- Crimson -- Lac Dye -- Scarlet -- Madder -- Alizarin -- Campeachy -- Quercitron -- Rhamnus -- Brazil Wood -- Alkanet -- Santal Wood -- Archil -- Coal-tar Lakes -- Red Lakes -- Alizarin Compounds -- Orange and Yellow Lakes -- Green and Blue Lakes -- Indigo -- Dragon's Blood -- Gamboge -- Sepia -- Indian Yellow, Puree -- Bitumen, Asphaltum, Mummy -- #Index.# #THE MANUFACTURE OF PAINT.# A Practical Handbook for Paint Manufacturers, Merchants and Painters. By J. CRUICKSHANK SMITH, B.Sc. Demy 8vo. 200 pp. Sixty Illustrations and One Large Diagram. Price 7s. 6d. net. (Post free, 7s. 10d. home; 8s. abroad.) #Contents.# Preparation of Raw Material -- Storing of Raw Material -- Testing and Valuation of Raw Material -- Paint Plant and Machinery -- The Grinding of White Lead -- Grinding of White Zinc -- Grinding of other White Pigments -- Grinding of Oxide Paints -- Grinding of Staining Colours -- Grinding of Black Paints -- Grinding of Chemical Colours -- Yellows -- Grinding of Chemical Colours -- Blues -- Grinding Greens -- Grinding Reds -- Grinding Lakes -- Grinding Colours in Water -- Grinding Colours in Turpentine -- The Uses of Paint -- Testing and Matching Paints -- Economic Considerations -- Index. #DICTIONARY OF CHEMICALS AND RAW PRODUCTS USED IN THE MANUFACTURE OF PAINTS, COLOURS, VARNISHES AND ALLIED PREPARATIONS.# By George H. HURST, F.C.S. Demy 8vo. 380 pp. Price 7s. 6d. net. (Post free, 8s. home; 8s. 6d. abroad.) #THE MANUFACTURE OF LAKE PIGMENTS FROM ARTIFICIAL COLOURS.# By Francis H. JENNISON, F.I.C., F.C.S. #Sixteen Coloured Plates, showing Specimens of Eighty-nine Colours, specially prepared from the Recipes given in the Book.# 136 pp. Demy 8vo. Price 7s. 6d. net. (Post free, 7s. 10d. home; 8s. abroad.) #Contents.# The Groups of the Artificial Colouring Matters -- The Nature and Manipulation of Artificial Colours -- Lake-forming Bodies for Acid Colours -- Lake-forming Bodies' Basic Colours -- Lake Bases -- The Principles of Lake Formation -- Red Lakes -- Orange, Yellow, Green, Blue, Violet and Black Lakes -- The Production of Insoluble Azo Colours in the Form of Pigments -- The General Properties of Lakes Produced from Artificial Colours -- Washing, Filtering and Finishing -- Matching and Testing Lake Pigments -- Index. #THE MANUFACTURE OF MINERAL AND LAKE PIGMENTS.# Containing (p. c03) Directions for the Manufacture of all Artificial, Artists and Painters' Colours, Enamel, Soot and Metallic Pigments. A Text-book for Manufacturers, Merchants, Artists and Painters. By Dr. Josef BERSCH. Translated by A. C. WRIGHT, M.A. (Oxon.), B.Sc. (Lond.). Forty-three Illustrations. 476 pp., demy 8vo. Price 12s. 6d. net. (Post free, 13s. home; 13s. 6d. abroad.) #Contents.# Introduction -- Physico-chemical Behaviour of Pigments -- Raw Materials Employed in the Manufacture of Pigments -- Assistant Materials -- Metallic Compounds -- The Manufacture of Mineral Pigments -- The Manufacture of White Lead -- Enamel White -- Washing Apparatus -- Zinc White -- Yellow Mineral Pigments -- Chrome Yellow -- Lead Oxide Pigments -- Other Yellow Pigments -- Mosaic Gold -- Red Mineral Pigments -- The Manufacture of Vermilion -- Antimony Vermilion -- Ferric Oxide Pigments -- Other Red Mineral Pigments -- Purple of Cassius -- Blue Mineral Pigments -- Ultramarine -- Manufacture of Ultramarine -- Blue Copper Pigments -- Blue Cobalt Pigments -- Smalts -- Green Mineral Pigments -- Emerald Green -- Verdigris -- Chromium Oxide -- Other Green Chromium Pigments -- Green Cobalt Pigments -- Green Manganese Pigments -- Compounded Green Pigments -- Violet Mineral Pigments -- Brown Mineral Pigments -- Brown Decomposition Products -- Black Pigments -- Manufacture of Soot Pigments -- Manufacture of Lamp Black -- The Manufacture of Soot Black without Chambers -- Indian Ink -- Enamel Colours -- Metallic Pigments -- Bronze Pigments -- Vegetable Bronze Pigments. PIGMENTS OF ORGANIC ORIGIN -- Lakes -- Yellow Lakes -- Red Lakes -- Manufacture of Carmine -- The Colouring Matter of Lac -- Safflower or Carthamine Red -- Madder and its Colouring Matters -- Madder Lakes -- Manjit (Indian Madder) -- Lichen Colouring Matters -- Red Wood Lakes -- The Colouring Matters of Sandal Wood and Other Dye Woods -- Blue Lakes -- Indigo Carmine -- The Colouring Matter of Log Wood -- Green Lakes -- Brown Organic Pigments -- Sap Colours -- Water Colours -- Crayons -- Confectionery Colours -- The Preparation of Pigments for Painting -- The Examination of Pigments -- Examination of Lakes -- The Testing of Dye-Woods -- The Design of a Colour Works -- Commercial Names of Pigments -- Appendix: Conversion of Metric to English Weights and Measures -- Centigrade and Fahrenheit Thermometer Scales -- Index. #RECIPES FOR THE COLOUR, PAINT, VARNISH, OIL, SOAP AND DRYSALTERY TRADES.# Compiled by AN ANALYTICAL CHEMIST. 350 pp. Demy 8vo. Price 7s. 6d. net. (Post free, 8s. home; 8s. 3d. abroad.) #Contents.# Pigments or Colours for Paints, Lithographic and Letterpress Printing Inks, etc. -- Mixed Paints and Preparations for Paint-making, Painting, Lime-washing, Paperhanging, etc. -- Varnishes for Coach-builders, Cabinetmakers, Wood-workers, Metal-workers, Photographers, etc. -- Soaps for Toilet, Cleansing, Polishing, etc. -- Perfumes -- Lubricating Greases, Oils, etc. -- Cements, Pastes, Glues and Other Adhesive Preparations -- Writing, Marking, Endorsing and Other Inks -- Sealing-wax and Office Requisites -- Preparations for the Laundry, Kitchen, Stable and General Household Uses -- Disinfectant Preparations -- Miscellaneous Preparations -- Index. #OIL COLOURS AND PRINTERS' INKS.# By Louis Edgar ANDÉS. Translated from the German. 215 pp. Crown 8vo. 56 Illustrations. Price 5s. net. (Post free, 5s. 4d. home; 5s. 6d. abroad.) #Contents.# Linseed Oil -- Poppy Oil -- Mechanical Purification of Linseed Oil -- Chemical Purification of Linseed Oil -- Bleaching Linseed Oil -- Oxidizing Agents for Boiling Linseed Oil -- Theory of Oil Boiling -- Manufacture of Boiled Oil -- Adulterations of Boiled Oil -- Chinese Drying Oil and Other Specialities -- Pigments for House and Artistic Painting and Inks -- Pigment for Printers' Black Inks -- Substitutes for Lampblack -- Machinery for Colour Grinding and Rubbing -- Machines for mixing Pigments with the Vehicle -- Paint Mills -- Manufacture of House Oil Paints -- Ship Paints -- Luminous Paint -- Artists' Colours -- Printers' Inks: -- VEHICLES -- Printers' Inks: -- PIGMENTS and MANUFACTURE -- Index. (_See also Writing Inks, p. 11._) #THREE HUNDRED SHADES FOR DECORATORS AND HOW TO MIX THEM.# (_See page 28._) #CASEIN.# By Robert SCHERER. Translated from the German by (p. c04) Chas. SALTER. Demy 8vo. Illustrated. 160 pp. Price 7s. 6d. net, (Post free, 7s. 10d. home; 8s. abroad.) #Contents.# #Casein: its Origin, Preparation and Properties. Various Methods of Preparing Casein. Composition and Properties of Casein. Casein Paints.# -- "Marble-Lime" Colour for Outside Work -- Casein Enamel Paint -- Casein Façade Paint -- Cold-Water Paint in Powder Form -- Kistory's Recipe for Casein Paint and Varnish -- Pure Casein Paints for Walls, etc. -- Casein Paints for Woodwork and Iron -- Casein-Silicate Paints -- Milk Paints -- Casein-Silicate Paint Recipes -- Trojel's Boiled Oil Substitute -- Calsomine Wash -- Quick-Drying Casein Paint -- Boiled Oil Substitute -- Ring's Cold-Water Paint -- Formo-lactin -- Waterproof Paint for Playing Cards -- Casein Colour Lake -- Casein-Cement Paint. #The Technics of Casein Painting. Casein Adhesives and Putties.# -- Casein Glue in Plates or Flakes -- Jeromin's Casein Adhesive -- Hall's Casein Glue -- Waterproof Glue -- Liquid Casein Glue -- Casein and Borax Glue -- Solid Casein Adhesive -- Casein Solution -- Glue Powder -- Casein Putties -- Washable Cement for Deal Boards -- Wenk's Casein Cement -- Casein and Lime Cement "Pitch Barm" -- Casein Stopping -- Casein Cement for Stone. #The Preparation of Plastic Masses from Casein.# -- Imitation Ivory -- Anti-Radiation and Anti-Corrosive Composition -- Dickmann's Covering for Floors and Walls -- Imitation Linoleum -- Imitation Leather -- Imitation Bone -- Plastic Mass of Keratin and Casein -- Insulating Mass -- Plastic Casein Masses -- Horny Casein Mass -- Plastic Mass from Celluloid -- Casein Cellulose Composition -- Fire-proof Cellulose Substitute -- Nitrocellulose and Casein Composition -- Franquet's Celluloid Substitute -- Galalith. #Uses of Casein in the Textile Industry, for Finishing Colour Printing, etc.# -- Caseogum -- "Glutin" -- Casein Dressing for Linen and Cotton Fabrics -- Printing Colour with Metallic Lustre -- Process for Softening, Sizing and Loading -- Fixing Casein and Other Albuminoids on the Fibre -- Fixing Insoluble Colouring Matters -- Waterproofing and Softening Dressing -- Casein for Mercerising Crèpe -- Fixing Zinc White on Cotton with Formaldehyde -- Casein-Magnesia -- Casein Medium for Calico Printing -- Loading Silk. #Casein Foodstuffs.# -- Casein Food -- Synthetic Milk -- Milk Food -- Emulsifiable Casein -- Casein Phosphate for Baking -- Making Bread, Low in Carbohydrates, from Flour and Curd -- Preparing Soluble Casein Compounds with Citrates -- Casein Food. #Sundry Applications of Casein.# -- Uses of Casein in the Paper Industry -- Metachromotype Paper -- Sizing Paper with Casein -- Waterproofing Paper -- Casein Solution for Coating Paper -- Horn's Clear Solution of Casein -- Water- and Fire-proof Asbestos Paper and Board -- Paper Flasks, etc., for Oils and Fats -- Washable Drawing and Writing Paper--Paper Wrappering for Food, Clothing, etc. -- Paint Remover -- Casein Photographic Plates -- Wood-Cement Roofing Pulp -- Cask Glaze of Casein and Formaldehyde -- Artists' Canvas -- Solidifying Mineral Oils -- Uses of Casein in Photography -- Casein Ointment -- Clarifying Glue with Casein -- Casein in Soap-making -- Casein-Albumose Soap -- Casein in Sheets, Blocks, etc. -- Waterproof Casein. #SIMPLE METHODS FOR TESTING PAINTERS' MATERIALS.# By A. C. WRIGHT, M.A. (Oxon.), B.Sc. (Lond.). Crown 8vo. 160 pp. #Price# 5s. net. (Post free, 5s. 3d. home; 5s. 6d. abroad.) #Contents.# Necessity for Testing -- Standards -- Arrangement -- The Apparatus -- The Reagents -- Practical Tests -- Dry Colours -- Stiff Paints -- Liquid and Enamel Paints -- Oil Varnishes -- Spirit Varnishes -- Driers -- Putty -- Linseed Oil -- Turpentine -- Water Stains -- The Chemical Examination -- Dry Colours and Paints -- White Pigments and Paints -- Yellow Pigments and Paints -- Blue Pigments and Paints -- Green Pigments and Paints -- Red Pigments and Paints -- Brown Pigments and Paints -- Black Pigments and Paints -- Oil Varnishes -- Linseed Oil -- Turpentine. #IRON-CORROSION, ANTI-FOULING AND ANTI-CORROSIVE PAINTS.# Translated from the German of Louis Edgar ANDÉS. Sixty-two Illustrations. 275 pp. Demy 8vo. Price 10s. 6d. net. (Post free, 10s. 10d. home; 11s. 3d. abroad.) #Contents.# Iron-rust and its Formation -- Protection from Rusting by Paint -- Grounding the Iron with Linseed Oil, etc. -- Testing Paints -- Use of Tar for Painting on Iron -- Anti-corrosive Paints -- Linseed Varnish -- Chinese Wood Oil -- Lead Pigments -- Iron Pigments -- Artificial Iron Oxides -- Carbon -- Preparation of Anti-corrosive Paints -- Results of Examination of Several Anti-corrosive Paints -- Paints for Ship's Bottoms -- Anti-fouling Compositions -- Various Anti-corrosive and Ship's Paints -- Official Standard Specifications for Ironwork Paints -- Index. #THE TESTING AND VALUATION OF RAW MATERIALS USED IN PAINT AND COLOUR MANUFACTURE.# By M. W. JONES, F.C.S. A Book for the Laboratories of Colour Works. 88 pp. Crown 8vo. Price 5s. net. (Post free, 5s. 3d. home and abroad.) #Contents.# (p. c05) Aluminium Compounds -- China Clay -- Iron Compounds -- Potassium Compounds -- Sodium Compounds -- Ammonium Hydrate -- Acids -- Chromium Compounds -- Tin Compounds -- Copper Compounds -- Lead Compounds -- Zinc Compounds -- Manganese Compounds -- Arsenic Compounds -- Antimony Compounds -- Calcium Compounds -- Barium Compounds -- Cadmium Compounds -- Mercury Compounds -- Ultramarine -- Cobalt and Carbon Compounds -- Oils -- Index. #STUDENTS' HANDBOOK OF PAINTS, COLOURS, OILS AND VARNISHES.# By John FURNELL. Crown 8vo. 12 Illustrations. 96 pp. Price 2s. 6d. net. (Post free, 2s. 9d. home and abroad.) #Contents.# Plant -- Chromes -- Blues -- Greens -- Earth Colours -- Blacks -- Reds -- Lakes -- Whites -- Painters' Oils -- Turpentine -- Oil Varnishes -- Spirit Varnishes -- Liquid Paints -- Enamel Paints. #VARNISHES AND DRYING OILS.# #OIL CRUSHING, REFINING AND BOILING, THE MANUFACTURE OF LINOLEUM, PRINTING AND LITHOGRAPHIC INKS, AND INDIA-RUBBER SUBSTITUTES.# By John GEDDES MCINTOSH. Being Volume I. of the Second, greatly enlarged, English Edition, in three Volumes, of "The Manufacture of Varnishes and Kindred Industries," based on and including the work of Ach. Livache. Demy 8vo. 150 pp. 29 Illustrations. Price 7s. 6d. net. (Post free, 7s. 10d. home; 8s. abroad.) #Contents.# Oil Crushing and Refining; Oil Boiling -- Theoretical and Practical; Linoleum Manufacture; Printing Ink Manufacture; Rubber Substitutes; The Manufacture of Driers; The Detection of Adulteration in Linseed and other Drying Oils by Chemical, Physical and Organoleptic Methods. #DRYING OILS, BOILED OIL AND SOLID AND LIQUID DRIERS.# By L. E. ANDÉS. Expressly Written for this Series of Special Technical Books, and the Publishers hold the Copyright for English and Foreign Editions. Forty-two Illustrations. 342 pp. Demy 8vo. Price 12s. 6d. net. (Post free, 13s. home; 13s. 3d. abroad.) #Contents.# Properties of the Drying Oils; Cause of the Drying Property; Absorption of Oxygen; Behaviour towards Metallic Oxides, etc. -- The Properties of and Methods for obtaining the Drying Oils -- Production of the Drying Oils by Expression and Extraction; Refining and Bleaching; Oil Cakes and Meal; The Refining and Bleaching of the Drying Oils; The Bleaching of Linseed Oil -- The Manufacture of Boiled Oil; The Preparation of Drying Oils for Use in the Grinding of Paints and Artists' Colours and in the Manufacture of Varnishes by Heating over a Fire or by Steam, by the Cold Process, by the Action of Air, and by Means of the Electric Current; The Driers used in Boiling Linseed Oil; The Manufacture of Boiled Oil and the Apparatus therefor; Livache's Process for Preparing a Good Drying Oil and its Practical Application -- The Preparation of Varnishes for Letterpress, Lithographic and Copperplate Printing, for Oilcloth and Waterproof Fabrics; The Manufacture of Thickened Linseed Oil, Burnt Oil, Stand Oil by Fire Heat, Superheated Steam, and by a Current of Air -- Behaviour of the Drying Oils and Boiled Oils towards Atmospheric Influences, Water, Acids and Alkalies -- Boiled Oil Substitutes -- The Manufacture of Solid and Liquid Driers from Linseed Oil and Rosin; Linolic Acid Compounds of the Driers -- The Adulteration and Examination of the Drying Oils and Boiled Oil. #OILS, FATS, GREASES, PETROLEUM.# #LUBRICATING OILS, FATS AND GREASES:# Their Origin, Preparation, Properties, Uses and Analyses. A Handbook for Oil Manufacturers, Refiners and Merchants, and the Oil and Fat Industry in General. By George H. HURST, F.C.S. Second Revised and Enlarged Edition. Sixty-five Illustrations. 317 pp. Demy 8vo. Price 10s. 6d. net. (Post free, 11s. home; 11s. 3d. abroad.) #Contents.# #Introductory -- Hydrocarbon Oils -- Scotch Shale Oils -- Petroleum -- Vegetable and Animal Oils -- Testing and Adulteration of Oils -- Lubricating Greases -- Lubrication -- Appendices -- Index.# #TECHNOLOGY OF PETROLEUM:# Oil Fields of the World -- Their (p. c06) History, Geography and Geology -- Annual Production and Development -- Oil-well Drilling -- Transport. By Henry NEUBERGER and Henry NOALHAT. Translated from the French by J. G. McINTOSH. 550 pp. 153 Illustrations. 26 Plates. Super Royal 8vo. Price 21s. net. (Post free, 21s. 9d. home; 23s. 6d. abroad.) #Contents.# #Study of the Petroliferous Strata.# #Excavations#--Hand Excavation or Hand Digging of Oil Wells. #Methods of Boring.# #Accidents# -- Boring Accidents -- Methods of preventing them -- Methods of remedying them -- Explosives and the use of the "Torpedo" Levigation -- Storing and Transport of Petroleum -- General Advice -- Prospecting, Management and carrying on of Petroleum Boring Operations. #General Data -- Customary Formulæ# -- Memento. Practical Part. General Data bearing on Petroleum -- Glossary of Technical Terms used in the Petroleum Industry -- Copious Index. #THE PRACTICAL COMPOUNDING OF OILS, TALLOW AND GREASE FOR LUBRICATION, ETC.# By AN EXPERT OIL REFINER. 100 pp. Demy 8vo. Price 7s. 6d. net. (Post free. 7s. 10d. home; 8s. abroad.) #Contents.# #Introductory Remarks# on the General Nomenclature of Oils, Tallow and Greases suitable for Lubrication -- #Hydrocarbon Oils -- Animal and Fish Oils -- Compound Oils -- Vegetable Oils -- Lamp Oils -- Engine Tallow, Solidified Oils and Petroleum Jelly -- Machinery Greases: Loco and Anti-friction -- Clarifying and Utilisation of Waste Fats, Oils, Tank Bottoms, Drainings of Barrels and Drums, Pickings Up, Dregs, etc. -- The Fixing and Cleaning of Oil Tanks, etc. -- Appendix and General Information.# #ANIMAL FATS AND OILS:# Their Practical Production, Purification and Uses for a great Variety of Purposes. Their Properties, Falsification and Examination. Translated from the German of Louis Edgar ANDÉS. Sixty-two Illustrations. 240 pp. Second Edition, Revised and Enlarged. Demy 8vo. Price 10s. 6d. net. (Post free, 10s. 10d. home; 11s. 3d. abroad.) #Contents.# Introduction -- Occurrence, Origin, Properties and Chemical Constitution of Animal Fats -- Preparation of Animal Fats and Oils -- Machinery -- Tallow-melting Plant -- Extraction Plant -- Presses -- Filtering Apparatus -- Butter: Raw Material and Preparation, Properties, Adulterations, Beef Lard or Remelted Butter, Testing -- Candle-fish Oil -- Mutton-Tallow -- Hare Fat -- Goose Fat -- Neatsfoot Oil -- Bone Fat: Bone Boiling, Steaming Bones, Extraction, Refining -- Bone Oil -- Artificial Butter: Oleomargarine, Margarine Manufacture in France, Grasso's Process, "Kaiser's Butter," Jahr & Münzberg's Method, Filbert's Process, Winter's Method -- Human Fat -- Horse Fat -- Beef Marrow -- Turtle Oil -- Hog's Lard: Raw Material -- Preparation, Properties, Adulterations, Examination -- Lard Oil -- Fish Oils -- Liver Oils -- Artificial Train Oil -- Wool Fat: Properties, Purified Wool Fat -- Spermaceti: Examination of Fats and Oils in General. #THE MANUFACTURE OF LUBRICANTS, SHOE POLISHES AND LEATHER DRESSINGS.# By Richard BRUNNER. Translated from the Sixth German Edition by Chas. SALTER. 10 Illustrations. Crown 8vo. 170 pp. Price 7s. 6d. net. (Post free, 7s. 10d. home; 8s. abroad.) #Contents.# The Manufacture of Lubricants and Greases -- Properties of the Bodies used as Lubricants -- Raw Materials for Lubricants -- Solid Lubricants -- Tallow Lubricants -- Palm Oil Greases -- Lead Soap Lubricants -- True Soap Greases -- Caoutchouc Lubricants -- Other Solid Lubricants -- Liquid Lubricants -- Lubricating Oils in General -- Refining Oils for Lubricating Purposes -- Cohesion Oils -- Resin Oils -- Lubricants of Fat and Resin Oil -- Neatsfoot Oil -- Bone Fat -- Lubricants for Special Purposes -- Mineral Lubricating Oils -- Clockmakers' and Sewing Machine Oils -- The Application of Lubricants to Machinery -- Removing Thickened Grease and Oil -- Cleaning Oil Rags and Cotton Waste -- The Use of Lubricants -- Shoe Polishes and Leather Softening Preparations -- The Manufacture of Shoe Polishes and Preparations for Varnishing and Softening Leather -- The Preparation of Bone Black -- Blacking and Shoe Polishes -- Leather Varnishes -- Leather Softening Preparations -- The Manufacture of Dégras. #THE OIL MERCHANTS' MANUAL AND OIL TRADE READY RECKONER.# (p. c07) Compiled by Frank P. SHERRIFF. Second Edition Revised and Enlarged. Demy 8vo. 214 pp. 1904. With Two Sheets of Tables. Price 7s. 6d. net. (Post free, 7s. 10d. home; 8s. 3d. abroad.) #Contents.# Trade Terms and Customs -- Tables to Ascertain Value of Oil sold per cwt. or ton -- Specific Gravity Tables -- Percentage Tare Tables -- Petroleum Tables -- Paraffine and Benzoline Calculations -- Customary Drafts -- Tables for Calculating Allowance for Dirt, Water, etc. -- Capacity of Circular Tanks Tables, etc., etc. #VEGETABLE FATS AND OILS:# Their Practical Preparation. Purification and Employment for Various Purposes, their Properties, Adulteration and Examination. Translated from the German of Louis Edgar ANDÉS. Ninety-four Illustrations. 340 pp. Second Edition. Demy 8vo. Price 10s. 6d. net. (Post free, 11s. home; 11s. 6d. abroad.) #Contents.# #General Properties# -- #Estimation of the Amount of Oil in Seeds# -- #The Preparation of Vegetable Fats and Oils# -- Apparatus for Grinding Oil Seeds and Fruits -- #Installation of Oil and Fat Works# -- Extraction Method of Obtaining Oils and Fats -- Oil Extraction Installations -- Press Moulds -- #Non-drying Vegetable Oils# -- #Vegetable drying Oils# -- #Solid Vegetable Fats# -- Fruits Yielding Oils and Fats -- Wool-softening Oils -- Soluble Oils -- Treatment of the Oil after Leaving the Press -- Improved Methods of Refining -- #Bleaching Fats and Oils# -- Practical Experiments on the Treatment of Oils with regard to Refining and Bleaching -- Testing Oils and Fats. #ESSENTIAL OILS AND PERFUMES.# #THE CHEMISTRY OF ESSENTIAL OILS AND ARTIFICIAL PERFUMES.# By Ernest J. PARRY, B.Sc. (Lond.), F.I.C., F.C.S. 411 pp. 20 Illustrations. Demy 8vo. Price 12s. 6d. net. (Post free, 13s. home; 13s. 6d. abroad.) #Contents.# #The General Properties of Essential Oils# -- Compounds #occurring in Essential Oils# -- #The Preparation of Essential Oils# -- #The Analysis of Essential Oils# -- #Systematic Study of the Essential Oils# -- #Terpeneless Oils# -- #The Chemistry of Artificial Perfumes# -- #Appendix:# Table of Constants -- #Index#. #SOAPS.# #SOAPS.# A Practical Manual of the Manufacture of Domestic, Toilet and other Soaps. By George H. HURST, F.C.S. 390 pp. 66 Illustrations. Price 12s. 6d. net. (Post free, 13s. home; 13s. 6d. abroad.) #Contents.# #Introductory -- Soap-maker's Alkalies -- Soap Fats and Oils -- Perfumes -- Water as a Soap Material -- Soap Machinery -- Technology of Soap-making -- Glycerine in Soap Lyes -- Laying out a Soap Factory -- Soap Analysis -- Appendices.# #TEXTILE SOAPS AND OILS.# Handbook on the Preparation, Properties and Analysis of the Soaps and Oils used in Textile Manufacturing, Dyeing and Printing. By George H. HURST, F.C.S. Crown 8vo. 195 pp. 1904. Price 5s. net. (Post free, 5s. 4d. home; 5s. 6d. abroad.) #Contents#. #Methods of Making Soaps# -- Hard Soap -- Soft Soap. #Special Textile Soaps# -- Wool Soaps -- Calico Printers' Soaps -- Dyers' Soaps. #Relation of Soap to Water for Industrial Purposes# -- Treating Waste Soap Liquors -- Boiled Off Liquor -- Calico Printers and Dyers' Soap Liquors -- #Soap Analysis# -- #Fat in Soap#. ANIMAL AND VEGETABLE OILS AND FATS -- Tallow -- Lard -- Bone Grease-Tallow Oil. #Vegetable Soap, Oils and Fats# -- Palm Oil -- Coco-nut Oil -- Olive Oil -- Cottonseed Oil -- Linseed Oil -- Castor Oil -- Corn Oil -- Whale Oil or Train Oil -- Repe Oil. GLYCERINE. TEXTILE OILS -- Oleic Acid -- Blended Wool Oils -- Oils for Cotton Dyeing, Printing and Finishing -- Turkey Red Oil -- Alizarine Oil -- Oleine -- Oxy Turkey Red Oils -- Soluble Oil-Analysis of Turkey Red Oil -- Finisher's Soluble Oil -- Finisher's Soap Softening -- Testing and Adulteration of Oils -- Index. COSMETICAL PREPARATIONS. (p. c08) #COSMETICS: MANUFACTURE, EMPLOYMENT AND TESTING OF ALL COSMETIC MATERIALS AND COSMETIC SPECIALITIES.# Translated from the German of Dr. Theodor KOLLER. Crown 8vo. 262 pp. Price 5s. net. (Post free, 5s. 4d. home; 5s. 6d. abroad.) #Contents.# Purposes and Uses of, and Ingredients used in the Preparation of Cosmetics -- Preparation of Perfumes by Pressure, Distillation, Maceration, Absorption or Enfleurage, and Extraction Methods -- Chemical and Animal Products used in the Preparation of Cosmetics -- Oils and Fats used in the Preparation of Cosmetics -- General Cosmetic Preparations -- Mouth Washes and Tooth Pastes -- Hair Dyes, Hair Restorers and Depilatories -- Cosmetic Adjuncts and Specialities -- Colouring Cosmetic Preparations -- Antiseptic Washes and Soaps -- Toilet and Hygienic Soaps -- Secret Preparations for Skin, Complexion, Teeth, Mouth, etc. -- Testing and Examining the Materials Employed in the Manufacture of Cosmetics -- Index. GLUE, BONE PRODUCTS AND MANURES. #GLUE AND GLUE TESTING.# By Samuel RIDEAL, D.Sc. (Lond.), F.I.C. Fourteen Engravings. 144 pp. Demy 8vo. Price 10s. 6d. net. (Post free, 10s. 10d. home; 11s. abroad.) #Contents.# #Constitution and Properties:# Definitions and Sources, Gelatine, Chondrin and Allied Bodies, Physical and Chemical Properties, Classification, Grades and Commercial Varieties -- #Raw Materials and Manufacture:# Glue Stock, Lining, Extraction, Washing and Clarifying, Filter Presses, Water Supply, Use of Alkalies, Action of Bacteria and of Antiseptics, Various Processes, Cleansing, Forming, Drying, Crushing, etc., Secondary Products -- #Uses of Glue:# Selection and Preparation for Use, Carpentry, Veneering, Paper-Making, Bookbinding, Printing Rollers, Hectographs, Match Manufacture, Sandpaper, etc., Substitutes for other Materials, Artificial Leather and Caoutchouc -- #Gelatine:# General Characters, Liquid Gelatine, Photographic Uses, Size, Tanno-, Chrome and Formo-Gelatine, Artificial Silk, Cements, Pneumatic Tyres, Culinary, Meat Extracts, Isinglass, Medicinal and other Uses, Bacteriology -- #Glue Testing:# Review of Processes, Chemical Examination, Adulteration, Physical Tests, Valuation of Raw Materials -- #Commercial Aspects#. #BONE PRODUCTS AND MANURES:# An Account of the most recent Improvements in the Manufacture of Fat, Glue, Animal Charcoal, Size, Gelatine and Manures. By Thomas LAMBERT, Technical and Consulting Chemist. Illustrated by Twenty-one Plans and Diagrams. 162 pp. Demy 8vo. Price 7s. 6d. net. (Post free, 7s. 10d. home; 8s. abroad.) #Contents.# Chemical Composition of Bones -- Arrangement of Factory -- Properties of Glue -- Glutin and Chondrin -- Skin Glue -- Liming of Skins -- Washing -- Boiling of Skins -- Clarification of Glue Liquors -- Glue-Boiling and Clarifying-House -- Specification of a Glue -- Size -- Uses and Preparation and Composition of Size -- Concentrated Size -- Properties of Gelatine -- Preparation of Skin Gelatine -- Drying -- Bone Gelatine -- Selecting Bones -- Crushing -- Dissolving -- Bleaching -- Boiling -- Properties of Glutin and Chondrin -- Testing of Glues and Gelatines -- The Uses of Glue, Gelatine and Size in Various Trades -- Soluble and Liquid Glues -- Steam and Waterproof Glues -- #Manures# -- Importation of Food Stuffs -- Soils -- Germination -- Plant Life -- #Natural Manures# -- Water and Nitrogen in Farmyard Manure -- Full Analysis of Farmyard Manure -- Action on Crops -- Water-Closet System -- Sewage Manure -- Green Manures -- #Artificial Manures# -- #Mineral Manures# -- Nitrogenous Matters -- Shoddy -- Hoofs and Horns -- Leather Waste -- Dried Meat -- Dried Blood -- Superphosphates -- Composition -- Manufacture -- Common Raw Bones -- Degreased Bones -- Crude Fat -- Refined Fat -- Degelatinised Bones -- Animal Charcoal -- Bone Superphosphates -- Guanos -- Dried Animal Products -- Potash Compounds -- Sulphate of Ammonia -- Extraction in Vacuo -- French and British Gelatines compared -- Index. CHEMICALS, WASTE PRODUCTS AND AGRICULTURAL CHEMISTRY. (p. c09) REISSUE OF #CHEMICAL ESSAYS OF C. W. SCHEELE#. First Published in English in 1786. Translated from the Academy of Sciences at Stockholm, with Additions. 300 pp. Demy 8vo, Price 5s. net. (Post free, 5s. 6d. home; 5s. 9d. abroad.) #Contents.# Memoir: C. W. Scheele and his work (written for this edition by J. G. McIntosh) -- On Fluor Mineral and its Acid -- On Fluor Mineral -- Chemical Investigation of Fluor Acid, with a View to the Earth which it Yields, by Mr. Wiegler -- Additional Information Concerning Fluor Minerals -- On Manganese, Magnesium, or Magnesia Vitrariorum -- On Arsenic and its Acid -- Remarks upon Salts of Benzoin--On Silex, Clay and Alum -- Analysis of the Calculus Vesical -- Method of Preparing Mercurius Dulcis Via Humida -- Cheaper and more Convenient Method of Preparing Pulvis Algarothi -- Experiments upon Molybdæna -- Experiments on Plumbago -- Method of Preparing a New Green Colour -- Of the Decomposition of Neutral Salts by Unslaked Lime and Iron -- On the Quantity of Pure Air which is Daily Present in our Atmosphere -- On Milk and its Acid -- On the Acid of Saccharum Lactis -- On the Constituent Parts of Lapis Ponderosus or Tungsten -- Experiments and Observations on Ether -- Index. #THE MANUFACTURE OF ALUM AND THE SULPHATES AND OTHER SALTS OF ALUMINA AND IRON.# Their Uses and Applications as Mordants in Dyeing and Calico Printing, and their other Applications in the Arts, Manufactures, Sanitary Engineering, Agriculture and Horticulture. Translated from the French of Lucien GESCHWIND. 195 Illustrations. 400 pp. Royal 8vo. Price 12s. 6d. net. (Post free, 13s. home; 13s. 6d. abroad.) #Contents.# #Theoretical Study of Aluminium, Iron, and Compounds of these Metals# -- Aluminium and its Compounds -- Iron and Iron Compounds. #Manufacture of Aluminium Sulphates and Sulphates of Iron# -- Manufacture of Aluminium Sulphate and the Alums -- Manufacture of Sulphates of Iron. #Uses of the Sulphates of Aluminium and Iron# -- Uses of Aluminium Sulphate and Alums -- Application to Wool and Silk -- Preparing and using Aluminium Acetates -- Employment of Aluminium Sulphate in Carbonising Wool -- The Manufacture of Lake Pigments -- Manufacture of Prussian Blue -- Hide and Leather Industry -- Paper Making -- Hardening Plaster -- Lime Washes -- Preparation of Non-inflammable Wood, etc. -- Purification of Waste Waters. -- #Uses and Applications of Ferrous Sulphate and Ferric Sulphates# -- Dyeing -- Manufacture of Pigments -- Writing Inks -- Purification of Lighting Gas -- Agriculture -- Cotton Dyeing -- Disinfectant -- Purifying Waste Liquors -- Manufacture of Nordhausen Sulphuric Acid -- Fertilising. #Chemical Characteristics of Iron and Aluminium# -- #Analysis of Various Aluminous or Ferruginous Products# -- Aluminium -- #Analysing Aluminium Products# --Alunite Alumina -- Sodium Aluminate -- Aluminium Sulphate -- #Iron# -- Analytical Characteristics of Iron Salts -- Analysis of Pyritic Lignite -- Ferrous and Ferric Sulphates -- Rouil Mordant -- Index. #AMMONIA AND ITS COMPOUNDS:# Their Manufacture and Uses. By Camille VINCENT, Professor at the Central School of Arts and Manufactures, Paris. Translated from the French by M. J. SALTER. Royal 8vo. 114 pp. Thirty-two Illustrations. Price 5s. net. (Post free, 5s. 4d. home; 5s. 6d. abroad.) #Contents.# #General Considerations#: Various Sources of Ammoniacal Products; Human Urine as a Source of Ammonia -- #Extraction of Ammoniacal Products from Sewage# -- #Extraction of Ammonia from Gas Liquor# -- #Manufacture of Ammoniacal Compounds from Bones, Nitrogenous Waste, Beetroot Wash and Peat# -- #Manufacture of Caustic Ammonia, and Ammonium Chloride, Phosphate and Carbonate# -- #Recovery of Ammonia from the Ammonia-Soda Mother Liquors# -- #Index#. #INDUSTRIAL ALCOHOL.# A Practical Manual on the Production and (p. c10) Use of Alcohol for Industrial Purposes and for Use as a Heating Agent, as an Illuminant and as a Source of Motive Power. By J. G. M'INTOSH, Lecturer on Manufacture and Applications of Industrial Alcohol at The Polytechnic, Regent Street, London. Demy 8vo. 1907. 250 pp. With 75 Illustrations and 25 Tables. Price 7s. 6d. net. (Post free, 7s. 9d. home; 8s. abroad.) #Contents.# #Alcohol and its Properties.# -- Ethylic Alcohol -- Absolute Alcohol -- Adulterations -- Properties of Alcohol -- Fractional Distillation -- Destructive Distillation -- Products of Combustion -- Alcoholometry -- Proof Spirit -- Analysis of Alcohol -- Table showing Correspondence between the Specific Gravity and Per Cents. of Alcohol over and under Proof -- Other Alcohol Tables. #Continuous Aseptic and Antiseptic Fermentation and Sterilisation in Industrial Alcohol Manufacture.# #The Manufacture of Industrial Alcohol from Beets.# -- Beet Slicing Machines -- Extraction of Beet Juice by Maceration, by Diffusion -- Fermentation in Beet Distilleries -- Plans of Modern Beet Distillery, #The Manufacture of Industrial Alcohol from Grain.# -- Plan of Modern Grain Distillery. #The Manufacture of Industrial Alcohol from Potatoes.# #The Manufacture of Industrial Alcohol from Surplus Stocks of Wine#, Spoilt Wine, Wine Marcs, and from Fruit in General. The Manufacture of Alcohol from the Sugar Cane and Sugar Cane Molasses -- Plans. #Plant, etc., for the Distillation and Rectification of Industrial Alcohol.# -- The Caffey and other "Patent" Stills -- Intermittent versus Continuous Rectification -- Continuous Distillation -- Rectification of Spent Wash. #The Manufacture and Uses of Various Alcohol Derivatives#, Ether, Haloid Ethers, Compound Ethers, Chloroform -- Methyl and Amyl Alcohols and their Ethereal Salts, Acetone -- Barbet's Ether, Methyl Alcohol and Acetone Rectifying Stills. #The Uses of Alcohol in Manufactures, etc.# -- List of Industries in which Alcohol is used, with Key to Function of Alcohol in each Industry. #The Uses of Alcohol for Lighting, Heating, and Motive Power.# #ANALYSIS OF RESINS AND BALSAMS.# Translated from the German of Dr. Karl DIETERICH. Demy 8vo. 340 pp. Price 7s. 6d. net. (Post free, 7s. 10d. home; 8s. 3d. abroad.) #MANUAL OF AGRICULTURAL CHEMISTRY.# By Herbert INGLE, F.I.C., Lecturer on Agricultural Chemistry, the Yorkshire College; Lecturer in the Victoria University. 388 pp. 11 Illustrations. Demy 8vo. Price 7s. 6d. net. (Post free, 8s. home; 8s. 6d. abroad.) #Contents.# Introduction -- The Atmosphere -- The Soil -- The Reactions occurring in Soils -- The Analysis of Soils -- Manures, Natural -- Manures (continued) -- The Analysis of Manures -- The Constituents of Plants -- The Plant -- Crops -- The Animal -- Foods and Feeding -- Milk and Milk Products -- The Analysis of Milk and Milk Products -- Miscellaneous Products used in Agriculture -- Appendix -- Index. #THE UTILISATION OF WASTE PRODUCTS.# A Treatise on the Rational Utilisation, Recovery and Treatment of Waste Products of all kinds. By Dr. Theodor KOLLER. Translated from the Second Revised German Edition. Twenty-two Illustrations. Demy 8vo. 280 pp. Price 7s. 6d. net. (Post free, 7s. 10d. home; 8s. 3d. abroad.) #Contents.# The Waste of Towns -- #Ammonia and Sal-Ammoniac# -- Rational Processes for Obtaining these Substances by Treating Residues and Waste -- Residues in the Manufacture of Aniline Dyes -- Amber Waste -- Brewers' Waste -- Blood and Slaughter-House Refuse -- Manufactured Fuels -- Waste Paper and Bookbinders' Waste -- Iron Slags -- Excrement -- Colouring Matters from Waste -- Dyers' Waste Waters -- Fat from Waste -- Fish Waste -- Calamine Sludge -- Tannery Waste -- Gold and Silver Waste -- India-rubber and Caoutchouc Waste -- Residues in the Manufacture of Rosin Oil -- Wood Waste -- Horn Waste -- Infusorial Earth -- Iridium from Goldsmiths' Sweepings -- Jute Waste -- Cork Waste -- Leather Waste -- Glue Makers' Waste -- Illuminating Gas from Waste and the By-Products of the Manufacture of Coal Gas -- Meerschum -- Molasses--Metal Waste -- By-Products in the Manufacture of Mineral Waters -- Fruit -- The By-Products of Paper and Paper Pulp Works -- By-Products in the Treatment of Coal Tar Oils -- Fur Waste -- The Waste Matter in the Manufacture of Parchment Paper -- Mother of Pearl Waste -- Petroleum Residues -- Platinum Residues -- Broken Porcelain, Earthenware and Glass -- Salt Waste -- Slate Waste -- Sulphur -- Burnt Pyrites -- Silk Waste -- Soap Makers' Waste -- Alkali Waste and the Recovery of Soda--Waste Produced in Grinding Mirrors -- Waste Products in the Manufacture of Starch -- Stearic Acid -- Vegetable Ivory Waste -- Turf -- Waste Waters of Cloth Factories -- Wine Residues -- Tinplate Waste -- Wool Waste -- Wool Sweat -- The Waste Liquids from Sugar Works -- Index. #WRITING INKS AND SEALING WAXES.# (p. c11) #INK MANUFACTURE:# Including Writing, Copying, Lithographic, Marking, Stamping, and Laundry Inks. By Sigmund LEHNER. Three Illustrations. Crown 8vo. 162 pp. Translated from the German of the Fifth Edition. Price 5s. net. (Post free, 5s. 3d. home; 5s. 6d. abroad.) #Contents.# Varieties of Ink -- Writing Inks -- Raw Materials of Tannin Inks -- The Chemical Constitution of the Tannin Inks -- Recipes for Tannin Inks -- Logwood Tannin Inks -- Ferric Inks -- Alizarine Inks--Extract Inks -- Logwood Inks -- Copying Inks -- Hektographs -- Hektograph Inks -- Safety Inks -- Ink Extracts and Powders -- Preserving Inks -- Changes in Ink and the Restoration of Faded Writing -- Coloured Inks -- Red Inks -- Blue Inks -- Violet Inks -- Yellow Inks -- Green Inks -- Metallic Inks -- Indian Ink -- Lithographic Inks and Pencils -- Ink Pencils -- Marking Inks -- Ink Specialities -- Sympathetic Inks -- Stamping Inks -- Laundry or Washing Blue -- Index. #SEALING-WAXES, WAFERS AND OTHER ADHESIVES FOR THE HOUSEHOLD, OFFICE, WORKSHOP AND FACTORY.# By H. C. STANDAGE. Crown 8vo. 96 pp. Price 5s. net. (Post free, 5s. 3d. home; 5s. 6d. abroad.) #Contents.# #Materials Used for Making Sealing=Waxes# -- The Manufacture of Sealing-Waxes -- Wafers -- Notes on the Nature of the Materials Used in Making Adhesive Compounds -- Cements for Use in the Household -- Office Gums, Pastes and Mucilages -- Adhesive Compounds for Factory and Workshop Use. #LEAD ORES AND COMPOUNDS.# #LEAD AND ITS COMPOUNDS.# By Thos. LAMBERT, Technical and Consulting Chemist. Demy 8vo. 226 pp. Forty Illustrations. Price 7s. 6d. net. (Post free, 7s. 10d. home; 8s. 3d. abroad.) #Contents.# History -- Ores of Lead -- Geographical Distribution of the Lead Industry -- Chemical and Physical Properties of Lead -- Alloys of Lead -- Compounds of Lead -- Dressing of Lead Ores -- Smelting of Lead Ores -- Smelting in the Scotch or American Ore-hearth -- Smelting in the Shaft or Blast Furnace -- Condensation of Lead Fume -- Desilverisation, or the Separation of Silver from Argentiferous Lead -- Cupellation -- The Manufacture of Lead Pipes and Sheets -- Protoxide of Lead -- Litharge and Massicot -- Red Lead or Minium -- Lead Poisoning -- Lead Substitutes -- Zinc and its Compounds -- Pumice Stone -- Drying Oils and Siccatives -- Oil of Turpentine Resin -- Classification of Mineral Pigments -- Analysis of Raw and Finished Products -- Tables -- Index. #NOTES ON LEAD ORES:# Their Distribution and Properties. By Jas. FAIRIE, F.G.S. Crown 8vo. 64 pages. Price 2s. 6d. net. (Post free, 2s. 9d. home; 3s. abroad.) #INDUSTRIAL HYGIENE.# #THE RISKS AND DANGERS TO HEALTH OF VARIOUS OCCUPATIONS AND THEIR PREVENTION.# By Leonard A. PARRY, M.D., B.Sc. (Lond.). 196 pp. Demy 8vo. Price 7s. 6d. net. (Post free, 7s. 10d. home; 8s. abroad.) #Contents.# Occupations which are Accompanied by the Generation and Scattering of Abnormal Quantities of Dust -- Trades in which there is Danger of Metallic Poisoning -- Certain Chemical Trades -- Some Miscellaneous Occupations --Trades in which Various Poisonous Vapours are Inhaled --General Hygienic Considerations -- Index. #INDUSTRIAL USES OF AIR, STEAM AND WATER.# (p. c12) #DRYING BY MEANS OF AIR AND STEAM.# Explanations, Formulæ, and Tables for Use in Practice. Translated from the German of E. HAUSRRAND. Two folding Diagrams and Thirteen Tables. Crown 8vo. 72 pp. Price 5s. net. (Post free, 5s. 3d. home; 5s. 6d. abroad.) #Contents.# British and Metric Systems Compared -- Centigrade and Fahr. Thermometers -- Estimation of the Maximum Weight of Saturated Aqueous Vapour which can be contained in 1 kilo. of Air at Different Pressure and Temperatures -- Calculation of the Necessary Weight and Volume of Air, and of the Least Expenditure of Heat, per Drying Apparatus with Heated Air, at the Atmospheric Pressure: _A_, With the Assumption that the Air is _Completely Saturated_ with Vapour both before Entry and after Exit from the Apparatus -- _B_, When the Atmospheric Air is Completely Saturated _before entry_, but at its _exit_ is _only_ 3/4, 1/2 or 1/4 Saturated -- _C_, When the Atmospheric Air is _not_ Saturated with Moisture before Entering the Drying Apparatus -- Drying Apparatus, in which, in the Drying Chamber, a Pressure is Artificially Created, Higher or Lower than that of the Atmosphere -- Drying by Means of Superheated Steam, without Air --Heating Surface, Velocity of the Air Current, Dimensions of the Drying Room, Surface of the Drying Material, Losses of Heat -- Index. (_See also "Evaporating, Condensing and Cooling Apparatus," p. 26._) #PURE AIR, OZONE AND WATER.# A Practical Treatise of their Utilisation and Value in Oil, Grease, Soap, Paint, Glue and other Industries, By W. B. COWELL. Twelve Illustrations. Crown 8vo. 85 pp. Price 5s. net. (Post free, 5s. 3d. home; 5s. 6d. abroad.) #Contents.# Atmospheric Air; Lifting of Liquids; Suction Process; Preparing Blown Oils; Preparing Siccative Drying Oils -- Compressed Air; Whitewash -- Liquid Air; Retrocession -- Purification of Water; Water Hardness -- Fleshings and Bones -- Ozonised Air in the Bleaching and Deodorising of Fats, Glues, etc.; Bleaching Textile Fibres -- Appendix: Air and Gases; Pressure of Air at Various Temperatures; Fuel; Table of Combustibles; Saving of Fuel by Heating Feed Water; Table of Solubilities of Scale Making Minerals; British Thermal Units Tables; Volume of the Flow of Steam into the Atmosphere; Temperature of Steam -- Index. #THE INDUSTRIAL USES OF WATER. COMPOSITION--EFFECTS--TROUBLES--REMEDIES--RESIDUARY WATERS--PURIFICATION--ANALYSIS.# By H. de la COUX. Royal 8vo. Translated from the French and Revised by Arthur MORRIS. 364 pp. 135 Illustrations. Price 10s. 6d. net. (Post free, 11s. home; 11s. 6d. abroad.) #Contents.# Chemical Action of Water in Nature and in Industrial Use -- Composition of Waters -- Solubility of Certain Salts in Water Considered from the Industrial Point of View -- Effects on the Boiling of Water -- Effects of Water in the Industries -- Difficulties with Water -- Feed Water for Boilers -- Water in Dye works, Print Works, and Bleach Works -- Water in the Textile Industries and in Conditioning -- Water in Soap Works -- Water in Laundries and Washhouses -- Water in Tanning -- Water in Preparing Tannin and Dyewood Extracts -- Water in Papermaking -- Water in Photography -- Water in Sugar Refining -- Water in Making Ices and Beverages -- Water in Cider Making -- Water in Brewing -- Water in Distilling -- Preliminary Treatment and Apparatus -- Substances Used for Preliminary Chemical Purification -- Commercial Specialities and their Employment -- Precipitation of Matters in Suspension in Water -- Apparatus for the Preliminary Chemical Purification of Water -- Industrial Filters -- Industrial Sterilisation of Water -- Residuary Waters and their Purification -- Soil Filtration -- Purification by Chemical Processes -- Analyses -- Index. (_See Books on Smoke Prevention, Engineering and Metallurgy, p. 26, etc._) #X RAYS.# (p. c13) #PRACTICAL X RAY WORK.# By Frank T. ADDYMAN, B.Sc. (Lond.), F.I.C., Member of the Roentgen Society of London; Radiographer to St. George's Hospital; Demonstrator of Physics and Chemistry, and Teacher of Radiography in St. George's Hospital Medical School. Demy 8vo. Twelve Plates from Photographs of X Ray Work. Fifty-two Illustrations. 200 pp. Price 10s. 6d. net. (Post free, 10s. 10d. home; 11s. 3d. abroad.) #Contents.# #Historical# -- Work leading up to the Discovery of the X Rays -- The Discovery--#Apparatus and its Management# -- Electrical Terms -- Sources of Electricity -- Induction Coils -- Electrostatic Machines -- Tubes -- Air Pumps -- Tube Holders and Stereoscopic Apparatus -- Fluorescent Screens -- #Practical X Ray Work# -- Installations -- Radioscopy -- Radiography -- X Rays in Dentistry -- X Rays in Chemistry -- X Rays in War -- Index. #List of Plates.# _Frontispiece_ -- Congenital Dislocation of Hip-Joint. -- I., Needle in Finger. -- II., Needle in Foot. -- III., Revolver Bullet in Calf and Leg. -- IV., A Method of Localisation. -- V., Stellate Fracture of Patella showing shadow of "Strapping". -- VI., Sarcoma. -- VII., Six-weeks-old Injury to Elbow showing new Growth of Bone. -- VIII., Old Fracture of Tibia and Fibula badly set. -- IX., Heart Shadow. -- X., Fractured Femur showing Grain of Splint. -- XI., Barrell's Method of Localisation. #INDIA-RUBBER AND GUTTA PERCHA.# #INDIA-RUBBER AND GUTTA-PERCHA.# Translated from the French of T. SEELIGMANN, G. LAMY TORVILHON and H. FALCONNET by John GEDDES McINTOSH. Royal 8vo. [_Out of print. Second Edition in preparation._] #Contents.# #India-Rubber# -- Botanical Origin -- Climatology -- Soil -- Rational Culture and Acclimation of the Different Species of India-Rubber Plants -- Methods of Obtaining the Latex -- Methods of Preparing Raw or Crude India-Rubber -- Classification of the Commercial Species of Raw Rubber -- Physical and Chemical Properties of the Latex and of India-Rubber -- Mechanical Transformation of Natural Caoutchouc into Washed or Normal Caoutchouc (Purification) and Normal Rubber into Masticated Rubber -- Softening, Cutting, Washing, Drying -- Preliminary Observations -- Vulcanisation of Normal Rubber -- Chemical and Physical Properties of Vulcanised Rubber -- General Considerations -- Hardened Rubber or Ebonite -- Considerations on Mineralisation and other Mixtures -- Coloration and Dyeing -- Analysis of Natural or Normal Rubber and Vulcanised Rubber -- Rubber Substitutes -- Imitation Rubber. #Gutta Percha# -- Botanical Origin -- Climatology -- Soil -- Rational Culture -- Methods of Collection -- Classification of the Different Species of Commercial Gutta Percha -- Physical and Chemical Properties -- Mechanical Transformation -- Methods of Analysing -- Gutta Percha Substitutes -- Index. #LEATHER TRADES.# #PRACTICAL TREATISE ON THE LEATHER INDUSTRY.# By A. M. VILLON. Translated by Frank T. ADDYMAN, B.Sc. (Lond.), F.I.C., F.C.S.; and Corrected by an Eminent Member of the Trade. 500 pp., royal 8vo. 123 Illustrations. Price 21s. net. (Post free, 21s. 6d. home; 22s. 6d. abroad.) #Contents.# Preface--Translator's Preface--List of Illustrations. Part I., #Materials used in Tanning# -- Skins: Skin and its Structure; Skins used in Tanning; Various Skins and their Uses -- Tannin and Tanning Substances: Tannin; Barks (Oak); Barks other than Oak; Tanning Woods; Tannin-bearing Leaves; Excrescences; Tan-bearing Fruits; Tan-bearing Roots and Bulbs; Tanning Juices; Tanning Substances used in Various Countries; Tannin Extracts; Estimation of Tannin and Tannin Principles. Part II., #Tanning# -- The Installation of a Tannery: Tan Furnaces; Chimneys, Boilers, etc.; Steam Engines -- Grinding and Trituration of Tanning Substances: Cutting up Bark; Grinding Bark; The Grinding of Tan Woods; Powdering Fruit, Galls and Grains; Notes on the Grinding of Bark -- Manufacture of Sole Leather: Soaking; Sweating and Unhairing; Plumping and Colouring; Handling; Tanning; Tanning Elephants' Hides; Drying; Striking or Pinning -- Manufacture of Dressing Leather: Soaking; Depilation; New Processes for the Depilation of Skins; Tanning; Cow Hides; Horse Hides; Goat Skins; Manufacture of (p. c14) Split Hides -- On Various Methods of Tanning: Mechanical Methods; Physical Methods; Chemical Methods; Tanning with Extracts -- Quantity and Quality; Quantity; Net Cost; Quality of Leather -- Various Manipulations of Tanned Leather: Second Tanning; Grease Stains; Bleaching Leather; Waterproofing Leather; Weighting Tanned Leather; Preservation of Leather -- Tanning Various Skins. Part III., #Currying# -- Waxed Calf: Preparation; Shaving; Stretching or Slicking; Oiling the Grain; Oiling the Flesh Side; Whitening and Graining; Waxing; Finishing; Dry Finishing; Finishing in Colour; Cost -- White Calf: Finishing in White -- Cow Hide for Upper Leathers: Black Cow Hide; White Cow Hide; Coloured Cow Hide -- Smooth Cow Hide -- Black Leather -- Miscellaneous Hides: Horse; Goat; Waxed Goat Skin; Matt Goat Skin -- Russia Leather: Russia Leather; Artificial Russia Leather. Part IV., #Enamelled, Hungary and Chamoy Leather, Morocco, Parchment, Furs and Artificial Leather# -- Enamelled Leather: Varnish Manufacture; Application of the Enamel; Enamelling in Colour -- Hungary Leather: Preliminary; Wet Work or Preparation; Aluming; Dressing or Loft Work; Tallowing; Hungary Leather from Various Hides -- Tawing: Preparatory Operations; Dressing; Dyeing Tawed Skins; Rugs -- Chamoy Leather -- Morocco: Preliminary Operations; Morocco Tanning: Mordants used in Morocco Manufacture; Natural Colours used in Morocco Dyeing; Artificial Colours; Different Methods of Dyeing; Dyeing with Natural Colours; Dyeing with Aniline Colours; Dyeing with Metallic Salts; Leather Printing; Finishing Morocco; Shagreen; Bronzed Leather -- Gilding and Silvering: Gilding; Silvering; Nickel and Cobalt -- Parchment -- Furs and Furriery: Preliminary Remarks; Indigenous Furs; Foreign Furs from Hot Countries; Foreign Furs from Cold Countries; Furs from Birds' Skins; Preparation of Furs; Dressing; Colouring; Preparation of Birds' Skins; Preservation of Furs -- Artificial Leather: Leather made from Scraps; Compressed Leather; American Cloth; Papier Mâché; Linoleum; Artificial Leather. Part V., #Leather Testing and the Theory of Tanning# -- Testing and Analysis of Leather: Physical Testing of Tanned Leather; Chemical Analysis -- The Theory of Tanning and the other Operations of the Leather and Skin Industry: Theory of Soaking; Theory of Unhairing; Theory of Swelling; Theory of Handling; Theory of Tanning; Theory of the Action of Tannin on the Skin; Theory of Hungary Leather Making; Theory of Tawing; Theory of Chamoy Leather Making; Theory of Mineral Tanning. Part VI., #Uses of Leather# -- Machine Belts: Manufacture of Belting; Leather Chain Belts; Various Belts; Use of Belts -- Boot and Shoe-making: Boots and Shoes; Laces -- Saddlery: Composition of a Saddle; Construction of a Saddle -- Harness: The Pack Saddle; Harness -- Military Equipment -- Glove Making -- Carriage Building -- Mechanical Uses. Appendix, #The World's Commerce in Leather# -- Europe; America; Asia; Africa; Australasia -- Index. #THE LEATHER WORKER'S MANUAL.# Being a Compendium of Practical Recipes and Working Formulæ for Curriers, Bootmakers, Leather Dressers, Blacking Manufacturers, Saddlers, Fancy Leather Workers. By H. C. STANDAGE. Demy 8vo. 165 pp. Price 7s. 6d. net. (Post free, 7s. 10d. home; 8s. abroad.) #Contents.# Blackings, Polishes, Glosses, Dressings, Renovators, etc., for Boot and Shoe Leather -- Harness Blackings, Dressings, Greases, Compositions, Soaps, and Boot-top Powders and Liquids, etc., etc. -- Leather Grinders' Sundries -- Currier's Seasonings, Blacking Compounds, Dressings, Finishes, Glosses, etc. -- Dyes and Stains for Leather --Miscellaneous Information -- Chrome Tannage -- Index. #BOOKS ON POTTERY, BRICKS, TILES, GLASS, ETC.# #THE MANUAL OF PRACTICAL POTTING.# Compiled by Experts, and Edited by Chas. F. BINNS. Revised Third Edition and Enlarged. 200 pp. Price 17s. 6d. net. (Post free, 17s. 10d. home; 18s. 3d. abroad.) #Contents.# #Introduction.# The Rise and Progress of the Potter's Art -- #Bodies#. China and Porcelain Bodies, Parian Bodies, Semi-porcelain and Vitreous Bodies, Mortar Bodies, Earthenwares Granite and C.C. Bodies, Miscellaneous Bodies, Sagger and Crucible Clays, Coloured Bodies, Jasper Bodies, Coloured Bodies for Mosaic Painting, Encaustic Tile Bodies, Body Stains, Coloured Dips -- #Glazes.# China Glazes, Ironstone Glazes, Earthenware Glazes, Glazes without Lead, Miscellaneous Glazes, Coloured Glazes, Majolica Colours -- #Gold and Gold Colours.# Gold, Purple of Cassius, Marone and Ruby, Enamel Coloured Bases, Enamel Colour Fluxes, Enamel Colours, Mixed Enamel Colours, Antique and Vellum Enamel Colours, Underglaze Colours, Underglaze Colour Fluxes, Mixed Underglaze Colours, Flow Powders, Oils and Varnishes -- #Means and Methods.# Reclamation of Waste Gold, The Use of Cobalt, Notes on Enamel Colours, Liquid or Bright Gold -- #Classification and Analysis.# Classification of Clay Ware, Lord Playfair's Analysis of Clays, The Markets of the World, Time and Scale of Firing, Weights of (p. c15) Potter's Material, Decorated Goods Count -- Comparative Loss of Weight of Clays -- Ground Felspar Calculations -- The Conversion of Slop Body Recipes into Dry Weight -- The Cost of Prepared Earthenware Clay -- #Forms and Tables.# Articles of Apprenticeship, Manufacturer's Guide to Stocktaking, Table of Relative Values of Potter's Materials, Hourly Wages Table, Workman's Settling Table, Comparative Guide for Earthenware and China Manufacturers in the use of Slop Flint and Slop Stone, Foreign Terms applied to Earthenware and China Goods, Table for the Conversion of Metrical Weights and Measures on the Continent and South America -- #Index.# #CERAMIC TECHNOLOGY:# Being some Aspects of Technical Science as Applied to Pottery Manufacture. Edited by Charles F. BINNS. 100 pp. Demy 8vo. Price 12s. 6d. net. (Post free, 12s. 10d. home; 13s. abroad.) #Contents.# Preface -- The Chemistry of Pottery -- Analysis and Synthesis -- Clays and their Components--The Biscuit Oven -- Pyrometry -- Glazes and their Composition -- Colours and Colour-making -- Index. #A TREATISE ON THE CERAMIC INDUSTRIES.# A Complete Manual for Pottery, Tile and Brick Works. By Emile BOURRY. Translated from the French by Wilton P. RIX, Examiner in Pottery and Porcelain to the City and Guilds of London Technical Institute, Pottery Instructor to the Hanley School Board. Royal 8vo. 760 pp. 323 Illustrations. Price 21s. net. (Post free, 22s. home; 24s. abroad.) #Contents.# Part I., #General Pottery Methods.# Definition and History. Definitions and Classification of Ceramic Products -- Historic Summary of the Ceramic Art -- Raw Materials of Bodies. Clays: Pure Clay and Natural Clays -- Various Raw Materials: Analogous to Clay -- Agglomerative and Agglutinative -- Opening -- Fusible -- Refractory -- Trials of Raw Materials -- Plastic Bodies. Properties and Composition -- Preparation of Raw Materials: Disaggregation -- Purification -- Preparation of Bodies: By Plastic Method -- By Dry Method -- By Liquid Method -- Formation, Processes of Formation: Throwing -- Expression -- Moulding by Hand, on the Jolley, by Compression, by Slip Casting -- Slapping -- Slipping -- Drying. Drying of Bodies -- Processes of Drying; By Evaporation -- By Aeration -- By Heating -- By Ventilation -- By Absorption -- Glazes. Composition and Properties -- Raw Materials -- Manufacture and Application -- Firing. Properties of the Bodies and Glazes during Firing -- Description of the Kilns -- Working of the Kilns -- Decoration. Colouring Materials -- Processes of Decoration. Part II., #Special Pottery Methods.# Terra Cottas. Classification: Plain Ordinary, Hollow, Ornamental, Vitrified, and Light Bricks -- Ordinary and Black Tiles -- Paving Tiles -- Pipes -- Architectural Terra Cottas -- Vases, Statues and Decorative Objects -- Common Pottery -- Pottery for Water and Filters -- Tobacco Pipes -- Lustre Ware -- Properties and Tests for Terra Cottas--Fireclay Goods. Classification: Argillaceous, Aluminous, Carboniferous, Silicious and Basic Fireclay Goods -- Fireclay Mortar (Pug) -- Tests for Fireclay Goods -- Faiences. Varnished Faiences -- Enamelled Faiences -- Silicious Faiences -- Pipeclay Faiences -- Pebble Work -- Feldspathic Faiences -- Composition, Processes of Manufacture and General Arrangements of Faience Potteries -- Stoneware. Stoneware Properly So-called: Paving Tiles -- Pipes -- Sanitary Ware -- Stoneware for Food Purposes and Chemical Productions -- Architectural Stoneware -- Vases, Statues and other Decorative Objects -- Fine Stoneware -- Porcelain. Hard Porcelain for Table Ware and Decoration, for the Fire, for Electrical Conduits, for Mechanical Purposes; Architectural Porcelain, and Dull or Biscuit Porcelain -- Soft Phosphated or English Porcelain -- Soft Vitreous Porcelain, French and New Sèvres -- Argillaceous Soft or Seger's Porcelain -- Dull Soft or Parian Porcelain -- Dull Feldspathic Soft Porcelain -- #Index.# #POTTERY DECORATING,# By R. HAINBACH. Translated from the German. Crown 8vo. 22 Illustrations. Deals with Glazes, Colours, etc. [_In the Press._] #ARCHITECTURAL POTTERY.# Bricks, Tiles, Pipes, Enamelled Terra-cottas, Ordinary and Incrusted Quarries, Stoneware Mosaics, Faïences and Architectural Stoneware. By Leon LEFÊVRE. With Five Plates. 950 Illustrations in the Text, and numerous estimates. 500 pp., royal 8vo. Translated from the French by K. H. BIRD, M.A., and W. Moore BINNS. Price 15s. net. (Post free, 15s. 6d. home; 16s. 6d. abroad.) #Contents.# Part I. #Plain Undecorated Pottery. -- Clays, Bricks, Tiles, Pipes, Chimney Flues, Terra-cotta.# Part II. #Made-up or Decorated Pottery.# #THE ART OF RIVETING GLASS, CHINA AND EARTHENWARE.# By J. HOWARTH. (p. c16) Second Edition. Paper Cover. Price 1s. net; by post, home or abroad, 1s. 1d. #NOTES ON POTTERY CLAYS.# Their Distribution, Properties, Uses and Analyses of Ball Clays, China Clays and China Stone. By Jas. FAIRIE, F.G.S. 132 pp. Crown 8vo. Price 3s. 6d. net. (Post free, 3s. 9d. home; 3s. 10d. abroad.) A Reissue of #THE HISTORY OF THE STAFFORDSHIRE POTTERIES; AND THE RISE AND PROGRESS OF THE MANUFACTURE OF POTTERY AND PORCELAIN.# With References to Genuine Specimens, and Notices of Eminent Potters. By Simeon SHAW. (Originally Published in 1829.) 265 pp. Demy 8vo. Price 7s. 6d. net. (Post free, 7s. 10d. home; 8s. 3d. abroad.) #Contents.# #Introductory Chapter# showing the position of the Pottery Trade at the present time (1899) -- #Preliminary Remarks# -- #The Potteries#, comprising Tunstall, Brownhills, Greenfield and New Field, Golden Hill, Latebrook, Green Lane, Burslem, Longport and Dale Hall, Hot Lane and Cobridge, Hanley and Shelton, Etruria, Stoke, Penkhull, Fenton, Lane Delph, Foley, Lane End -- #On the Origin of the Art#, and its Practice among the early Nations -- #Manufacture of Pottery#, prior to 1700 -- #The Introduction of Red Porcelain# by Messrs. Elers, of Bradwell, 1690 -- #Progress of the Manufacture# from 1700 to Mr. Wedgwood's commencement in 1760 -- #Introduction of Fluid Glaze# -- Extension of the Manufacture of Cream Colour -- Mr. Wedgwood's Queen's Ware -- Jasper, and Appointment of Potter to Her Majesty -- Black Printing -- #Introduction of Porcelain.# Mr. W. Littler's Porcelain -- Mr. Cookworthy's Discovery of Kaolin and Petuntse, and Patent -- Sold to Mr. Champion -- resold to the New Hall Com. -- Extension of Term -- #Blue Printed Pottery.# Mr. Turner, Mr. Spode (1), Mr. Baddeley, Mr. Spode (2), Messrs. Turner, Mr. Wood, Mr. Wilson, Mr. Minton -- Great Change in Patterns of Blue Printed -- #Introduction of Lustre Pottery.# Improvements in Pottery and Porcelain subsequent to 1800. A Reissue of #THE CHEMISTRY OF THE SEVERAL NATURAL AND ARTIFICIAL HETEROGENEOUS COMPOUNDS USED IN MANUFACTURING PORCELAIN, GLASS AND POTTERY#. By Simeon SHAW. (Originally published in 1837.) 750 pp. Royal 8vo. Price 14s. net. (Post free, 15s. home; 17s. abroad.) #GLASSWARE, GLASS STAINING AND PAINTING.# #RECIPES FOR FLINT GLASS MAKING.# By a British Glass Master and Mixer. Sixty Recipes. Being Leaves from the Mixing Book of several experts in the Flint Glass Trade, containing up-to-date recipes and valuable information as to Crystal, Demi-crystal and Coloured Glass in its many varieties. It contains the recipes for cheap metal suited to pressing, blowing, etc., as well as the most costly crystal and ruby. Crown 8vo. Price 10s. 6d. net. (Post free, 10s. 9d. home; 10s. 10d. abroad.) #Contents.# Ruby -- Ruby from Copper -- Flint for using with the Ruby for Coating -- A German Metal -- Cornelian, or Alabaster -- Sapphire Blue -- Crysophis -- Opal -- Turquoise Blue -- Gold Colour -- Dark Green -- Green (common) -- Green for Malachite -- Blue for Malachite -- Black for Malachite -- Black -- Common Canary Batch -- Canary -- White Opaque Glass -- Sealing-wax Red -- Flint -- Flint Glass (Crystal and Demi) -- Achromatic Glass -- Paste Glass -- White Enamel -- Firestone--Dead White (for moons) -- White Agate -- Canary -- Canary Enamel -- Index. #A TREATISE ON THE ART OF GLASS PAINTING.# Prefaced with a Review (p. c17) of Ancient Glass. By Ernest R. SUFFLING. With One Coloured Plate and Thirty-seven Illustrations. Demy 8vo. 140 pp. Price 7s. 6d. net. (Post free, 7s. 10d. home; 8s. abroad.) #Contents.# A Short History of Stained Glass -- Designing Scale Drawings --Cartoons and the Cut Line -- Various Kinds of Glass Cutting for Windows -- The Colours and Brushes used in Glass Painting -- Painting on Glass, Dispersed Patterns -- Diapered Patterns -- Aciding -- Firing -- Fret Lead Glazing -- Index. #PAINTING ON GLASS AND PORCELAIN AND ENAMEL PAINTING.# A Complete Introduction to the Preparation of all the Colours and Fluxes used for Painting on Porcelain, Enamel, Faïence and Stoneware, the Coloured Pastes and Coloured Glasses, together with a Minute Description of the Firing of Colours and Enamels. By Felix HERMANN, Technical Chemist. With Eighteen Illustrations. 300 pp. Translated from the German second and enlarged Edition. Price 10s. 6d. net. (Post free, 10s. 10d. home; 11s. abroad.) #PAPER MAKING, PAPER DYEING, AND TESTING.# #THE DYEING OF PAPER PULP.# A Practical Treatise for the use of Papermakers, Paperstainers, Students and others. By Julius ERFURT, Manager of a Paper Mill. Translated into English and Edited with Additions by Julius HÜBNER, F.C.S., Lecturer on Papermaking at the Manchester Municipal Technical School. With Illustrations and #157 patterns of paper dyed in the pulp#. Royal 8vo, 180 pp. Price 15s. net. (Post free, 15s. 6d. home; 16s. 6d. abroad.) #Contents.# #Behaviour of the Paper Fibres during the Process of Dyeing, Theory of the Mordant# -- #Colour Fixing Mediums# (#Mordants#) -- #Influence of the Quality of the Water Used# -- #Inorganic Colours# -- #Organic Colours# -- #Practical Application of the Coal Tar Colours according to their Properties and their Behaviour towards the Different Paper Fibres# -- #Dyed Patterns on Various Pulp Mixtures# -- #Dyeing to Shade# -- Index. #THE PAPER MILL CHEMIST.# By Henry P. STEVENS, M.A., Ph.D., F.I.C. Royal 12mo. 60 Illustrations. [_In the press._] #Contents.# #Introduction.# -- Dealing with the Apparatus required in Chemical Work and General Chemical Manipulation, introducing the subject of Qualitative and Quantitative Analysis. #Fuels.# -- Analysis of Coal, Coke and other Fuels -- Sampling and Testing for Moisture, Ash, Calorific Value, etc. -- Comparative Heating Value of different Fuels and Relative Efficiency. #Water.# -- Analysis for Steam Raising and for Paper Making Purposes generally -- Water Softening and Purification -- A List of the more important Water Softening Plant, giving Power required, Weight, Space Occupied, Out-put and Approximate Cost. #Raw Materials and Detection of Adulterants.# -- Analysis and Valuation of the more important Chemicals used in Paper Making, including Lime, Caustic Soda, Sodium Carbonate, Mineral Acids, Bleach Antichlor, Alum, Rosin and Rosin Size, Glue Gelatin and Casein, Starch, China Clay, Blanc Fixe, Satin White and other Loading Materials, Mineral Colours and Aniline Dyes. #Manufacturing Operations.# -- Rags and the Chemical Control of Rag Boiling -- Esparto Boiling -- Wood Boiling -- Testing Spent Liquors and Recovered Ash -- Experimental Tests with Raw Fibrous Materials -- Boiling in Autoclaves -- Bleaching and making up Hand Sheets -- Examination of Sulphite Liquors -- Estimation of Moisture in Pulp and Half-stuff -- Recommendations of the British Wood Pulp Association. #Finished Products.# -- Paper Testing, including Physical, Chemical and Microscopical Tests, Area, Weight, Thickness, Apparent Specific Gravity, Bulk or Air Space. Determination of Machine Direction, Thickness, Strength, Stretch, Resistance to Crumpling and Friction, Transparency, Absorbency and other qualities of Blotting Papers -- Determination of the Permeability of Filtering Papers -- Detection and Estimation of Animal and Vegetable Size in Paper -- Sizing Qualities of Paper -- Fibrous Constituents -- Microscopical Examination of Fibres -- The Effect of Beating on Fibres -- Staining Fibres -- Mineral Matter -- Ash -- Qualitative and Quantitative Examination of Mineral Matter -- Examination of Coated Papers and Colouring Matters in Paper. #Tables.# -- English and Metrical Weights and Measures with (p. c18) Equivalents -- Conversion of Grams to Grains and _vice versa_ -- Equivalent Costs per lb., cwt., and ton -- Decimal Equivalents of lbs., qrs., and cwts. -- Thermometric and Barometric Scales -- Atomic Weights and Molecular Weights -- Factors for Calculating the Percentage of Substance Sought from the Weight of Substance Found -- Table of Solubilities of Substances Treated of in Paper Making -- Specific Gravity Tables of such substances as are used in Paper Making, including Sulphuric Acid Hydrochloric Acid, Bleach, Milk of Lime, Caustic Soda, Carbonate of Soda, etc., giving Percentage Strength with Specific Gravity and Degrees Tw. -- Hardness Table for Soap Tests -- Dew Point -- Wet and Dry Bulb Tables -- Properties of Saturated Steam, giving Temperature, Pressure and Volume -- List of Different Machines used in the Paper Making Industry, giving Size, Weight, Space Occupied, Power to Drive, Out-put and Approximate Cost -- Calculation of Moisture in Pulp --Rag-Boiling Tables, giving Percentages of Lime Soda and Time required -- Loss in Weight in Rags and other Raw Materials during Boiling and Bleaching -- Conditions of Buying and Selling as laid down by the Paper Makers' Association -- Table of Names and Sizes of Papers --Table for ascertaining the Weight per Ream from the Weight per Sheet -- Calculations of Areas and Volumes -- Logarithms -- Blank pages for Notes. #THE TREATMENT OF PAPER FOR SPECIAL PURPOSES.# By L. E. ANDÉS. Translated from the German. Crown 8vo. 48 Illustrations. 250 pp. [_In the Press._] #Contents.# #I., Parchment Paper, Vegetable Parchment.# -- The Parchment Paper Machine -- Opaque Supple Parchment Paper -- Thick Parchment -- Krugler's Parchment Paper and Parchment Slates -- Double and Triple Osmotic Parchment -- Utilising Waste Parchment Paper -- Parchmented Linen and Cotton -- Parchment Millboard -- Imitation Horn and Ivory from Parchment Paper -- Imitation Parchment Paper -- Artificial Parchment -- Testing the Sulphuric Acid. II., Papers for Transfer Pictures. #III., Papers for Preservative and Packing Purposes.# -- Butter Paper -- Wax Paper -- Paraffin Paper -- Wrapping Paper for Silverware -- Waterproof Paper -- Anti-corrosive Paper. IV., Grained Transfer Papers. V., Fire-proof and Antifalsification Papers, #VI., Paper Articles.# -- Vulcanised Paper Maché -- Paper Bottles -- Plastic Articles of Paper -- Waterproof Coverings for Walls and Ceilings -- Paper Wheels, Roofing and Boats -- Paper Barrels -- Paper Boxes -- Paper Horseshoes. VII., Gummed Paper. VIII., Hectograph Papers. #IX., Insecticide Papers.# -- Fly Papers -- Moth Papers. #X., Chalk and Leather Papers.# -- Glacé Chalk Paper -- Leather Paper -- Imitation Leather. XI., Luminous Papers -- Blue-Print Papers -- Blotting Papers. XII., Metal Papers -- Medicated Papers. XIII., Marbled Papers. XIV., Tracing and Copying Papers -- Iridescent or Mother of Pearl Papers. XV., Photographic Papers -- Shellac Paper -- Fumigating Papers -- Test Papers. #XVI., Papers for Cleaning and Polishing Purposes -- Glass Paper# -- Pumice Paper -- Emery Paper. XVII., Lithographic Transfer Papers. #XIX., Sundry Special Papers# -- Satin Paper -- Enamel Paper -- Cork Paper -- Split Paper -- Electric Paper -- Paper Matches -- Magic Pictures -- Laundry Blue Papers -- Blue Paper for Bleachers. XX., Waterproof Papers -- Washable Drawing Papers -- Washable Card -- Washable Coloured Paper--Waterproof Millboard -- Sugar Paper. XXI., The Characteristics of Paper -- Paper Testing. ENAMELLING ON METAL. #ENAMELS AND ENAMELLING.# For Enamel Makers, Workers in Gold and Silver, and Manufacturers of Objects of Art. By Paul RANDAU. Translated from the German. With Sixteen Illustrations. Demy 8vo. 180 pp. Price 10s. 6d. net. (Post free, 10s. 10d. home; 11s. abroad.) #THE ART OF ENAMELLING ON METAL.# By W. Norman BROWN. Twenty-eight Illustrations. Crown 8vo. 60 pp. Price 2s. 6d. net. (Post free, 2s. 9d. home and abroad.) SILK MANUFACTURE. #SILK THROWING AND WASTE SILK SPINNING.# By Hollins RAYNER. Demy 8vo. 170 pp. 117 Illus. Price 5s. net. (Post free, 5s. 4d. home; 5s. 6d. abroad.) #Contents.# The Silkworm -- Cocoon Reeling and Qualities of Silk -- Silk Throwing -- Silk Wastes -- The Preparation of Silk Waste for Degumming -- Silk Waste Degumming, Schapping and Discharging -- The Opening and Dressing of Wastes -- Silk Waste "Drawing" or "Preparing" Machinery -- Long Spinning -- Short Spinning -- Spinning and Finishing Processes -- Utilisation of Waste Products -- Noil Spinning -- Exhaust Noil Spinning. BOOKS ON TEXTILE AND DYEING SUBJECTS. (p. c19) #THE CHEMICAL TECHNOLOGY OF TEXTILE FIBRES#: Their Origin, Structure, Preparation, Washing, Bleaching, Dyeing, Printing and Dressing. By Dr. Georg von GEORGIEVICS. Translated from the German by Charles SALTER. 320 pp. Forty-seven Illustrations. Royal 8vo. Price 10s. 6d. net. (Post free, 11s. home; 11s. 3d. abroad.) #Contents.# #The Textile Fibres# -- #Washing, Bleaching, Carbonising# -- #Mordants and Mordanting# -- #Dyeing# -- #Printing# -- #Dressing and Finishing.# #POWER-LOOM WEAVING AND YARN NUMBERING.# According to Various Systems, with Conversion Tables. Translated from the German of Anthon GRUNER. #With Twenty-Six Diagrams in Colours.# 150 pp. Crown 8vo. Price 7s. 6d. net. (Post free, 7s. 9d. home; 8s. abroad.) #Contents.# #Power-Loom Weaving in General.# Various Systems of Looms -- #Mounting and Starting the Power-Loom.# English Looms -- Tappet or Treadle Looms -- Dobbies -- #General Remarks on the Numbering, Reeling and Packing of Yarn# -- #Appendix# -- #Useful Hints.# Calculating Warps -- Weft Calculations -- Calculations of Cost Price in Hanks. #TEXTILE RAW MATERIALS AND THEIR CONVERSION INTO YARNS.# (The Study of the Raw Materials and the Technology of the Spinning Process.) By Julius ZIPSER. Translated from German by Charles SALTER. 302 Illustrations. 500 pp. Demy 8vo. Price 10s. 6d. net. (Post free, 11s. home; 11s. 6d. abroad.) #Contents.# #PART 1. -- The Raw Materials Used in the Textile Industry.# MINERAL RAW MATERIALS. VEGETABLE RAW MATERIALS. ANIMAL RAW MATERIALS. #PART II. -- The Technology of Spinning or the Conversion of Textile Raw Materials into Yarn.# SPINNING VEGETABLE RAW MATERIALS. Cotton Spinning -- Installation of a Cotton Mill -- Spinning Waste Cotton and Waste Cotton Yarns -- Flax Spinning -- Fine Spinning -- Tow Spinning -- Hemp Spinning -- Spinning Hemp Tow String -- Jute Spinning -- Spinning Jute Line Yarn -- Utilising Jute Waste. #PART III. -- Spinning Animal Raw Materials.# Spinning Carded Woollen Yarn -- Finishing Yarn -- Worsted Spinning -- Finishing Worsted Yarn -- Artificial Wool or Shoddy Spinning -- Shoddy and Mungo Manufacture -- Spinning Shoddy and other Wool Substitutes -- Spinning Waste Silk -- Chappe Silk -- Fine Spinning -- Index. #GRAMMAR OF TEXTILE DESIGN.# By H. NISBET, Weaving and Designing Master, Bolton Municipal Technical School. Demy 8vo. 280 pp. 490 Illustrations and Diagrams. Price 6s. net. (Post free, 6s. 10d. home; 7s. abroad.) #Contents.# Chapter I., INTRODUCTION. -- General Principle of Fabric Structure and the use of Design Paper. Chapter II., THE PLAIN WEAVE AND ITS MODIFICATIONS. -- #The Plain, Calico, or Tabby Weave#. -- Firmness of Texture -- Variety of Texture -- Variety of Form: Ribbed Fabrics -- Corded Fabrics -- Matt Weaves. Chapter III., TWILL AND KINDRED WEAVES. -- Classification of Twill Weaves. -- #1. Continuous Twills# -- (_a_) _Warp-face Twills_ -- (_b_) _Weft-face Twills_ -- (_c_) _Warp and Weft-face Twills_ -- The Angle of Twill -- Influences affecting the Prominence of Twills and Kindred Weaves (_a_) _Character of Weave_, (_b_) _Character of Yarn_, (_c_) _Number of Threads per Inch_, (_d_) _Direction of Twill in Relation to the Direction of Twist in Yarn_ -- #2. Zigzag or Wavy Twills# -- 3. #Rearranged Twills#: Satin Weaves -- Table of Intervals of Selection for the Construction of Satin Weaves -- Corkscrew Twills -- Rearrangement of Twill Weaves on Satin and other Bases -- #4. Combined Twills# -- #5. Broken Twills# -- #6. Figured or Ornamented Twills#. Chapter IV., DIAMOND AND KINDRED WEAVES, -- #Diamond Weaves.# -- Honeycomb and Kindred Weaves -- Brighton Weaves -- Sponge Weaves -- Huck-a-Back and Kindred Weaves -- Grecian Weaves -- Linear Zigzag Weaves. Chapter V., BEDFORD CORDS. -- Plain Calico-ribbed Bedford Cords (p. c20) -- Plain Twill-ribbed Bedford Cords -- Figured Bedford Cords -- Tabulated Data of Particulars relating to the Manufacture of Seventeen Varieties of Bedford Cord Fabrics described in this Chapter. Chapter VI., BACKED FABRICS. -- Weft-backed Fabrics -- Warp-backed Fabrics -- Reversible or Double-faced Fabrics. Chapter VII., FUSTIANS. -- #Varieties of Fustians.# -- Imperials or Swansdowns -- Cantoons or Diagonals -- Moleskins -- Beaverteens -- #Velveteens# and Velveteen Cutting -- Ribbed or Corded Velveteen -- Figured Velveteen -- #Corduroy# -- Figured Corduroy -- Corduroy Cutting Machines. Chapter VIII., TERRY PILE FABRICS. -- Methods of producing Terry Pile on Textile Fabrics -- Terry-forming Devices -- Varieties of Terry Fabrics -- Action of the Reed in Relation to Shedding -- Figured Terry Weaving -- Practical Details of Terry Weaving. Chapter IX., GAUZE AND LENO FABRICS. -- #Gauze, Net Leno, and Leno Brocade Varieties of Cross-Weaving.# -- Plain Gauze, and a Heald Gauze or Leno Harness -- Net Leno Fabrics -- Gauze and Net Leno Figuring by means of several Back Standard Healds to each Doup Heald -- #Leno Specialities produced by a System of Crossing Warp Ends in _front_ of the Reed# -- A Device for the Production of Special Leno Effects -- Full Cross Leno Fabrics -- Relative Merits of a Top and a Bottom Doup Harness -- Relative Merits of Different Types of Dobbies for Gauze and Leno Fabrics -- Shaking Devices for Leno Weaving -- Practical Details of Leno Weaving -- #Tempered Steel-wire Doup Harnesses for Cross-weaving# -- Mock or Imitation Leno Fabrics. Chapter X., TISSUE, LAPPET, AND SWIVEL FIGURING; ALSO ONDULÉ EFFECTS, AND LOOPED FABRICS. -- #Tissue Figuring# -- Madras Muslin Curtains -- #Lappet Figuring# -- Spot Lappet Figuring -- #Swivel Figuring# -- #Woven Ondulé Effects# -- Loom for Weaving Ondulé Effects -- Weft Ondulé Effects -- #Looped Fabrics.# -- INDEX. #NEEDLEWORK AND DESIGN.# By Miss M. E. WILKINSON. Quarto. 24 Plates and Text. 52 pp. [_In the Press._] #HOME LACE-MAKING.# A Handbook for Teachers and Pupils. By M. E. W. MILROY. Crown 8vo. 64 pp. With 3 Plates and 9 Diagrams. Price 1s. net. (Post free, 1s. 3d. home; 1s. 4d. abroad.) #THE CHEMISTRY OF HAT MANUFACTURING.# Lectures delivered before the Hat Manufacturers' Association. By Watson SMITH, F.C.S., F.I.C. Revised and Edited by Albert SHONK, Crown 8vo. 132 pp. 16 Illustrations. Price 7s. 6d. net. (Post free, 7s. 9d. home; 7s. 10d. abroad.) #Contents.# Textile Fibres, principally Wool, Fur, and Hair -- Water: its Chemistry and Properties; Impurities and their Action; Tests of Purity -- Acids and Alkalis -- Boric Acid, Borax, Soap -- Shellac, Wood Spirit, and the Stiffening and Proofing Process -- Mordants: their Nature and Use -- Dye-stuffs and Colours -- Dyeing of Wool and Fur; and Optical Properties of Colours-Index. #THE TECHNICAL TESTING OF YARNS AND TEXTILE FABRICS.# With Reference to Official Specifications. Translated from the German of Dr. J. HERZFELD. Second Edition. Sixty-nine Illustrations. 200 pp. Demy 8vo. Price 10s. 6d. net. (Post free, 10s. 10d. home; 11s. abroad.) #Contents.# #Yarn Testing. Determining the Yarn Number# -- #Testing the Length of Yarns# -- #Examination of the External Appearance of Yarn# -- #Determining the Twist of Yarn and Twist# -- #Determination of Tensile Strength and Elasticity# -- #Estimating the Percentage of Fat in Yarn# -- #Determination of Moisture# (Conditioning) -- #Appendix#. #DECORATIVE AND FANCY TEXTILE FABRICS.# By R. T. LORD. Manufacturers and Designers of Carpets, Damask, Dress and all Textile Fabrics. 200 pp. Demy 8vo. 132 Designs and Illustrations. Price 7s. 6d. net. (Post free, 7s. 10d. home; 8s. abroad.) #THEORY AND PRACTICE OF DAMASK WEAVING.# By H. KINZER and K. WALTER. Royal 8vo. Eighteen Folding Plates Six Illustrations. Translated from the German. 110 pp. Price 8s. 6d. net. (Post free, 9s. home; 9s. 6d. abroad.) #Contents.# (p. c21) #The Various Sorts of Damask Fabrics# -- Drill (Ticking, Handloom-made) -- Whole Damask for Tablecloths -- Damask with Ground- and Connecting-warp Threads -- Furniture Damask -- Lampas or Hangings -- Church Damasks -- #The Manufacture of Whole Damask# -- Damask Arrangement with and without Cross-Shedding -- The Altered Cone-arrangement -- The Principle of the Corner Lifting Cord -- The Roller Principle -- The Combination of the Jacquard with the so-called Damask Machine -- The Special Damask Machine -- The Combination of Two Tyings. #FAULTS IN THE MANUFACTURE OF WOOLLEN GOODS AND THEIR PREVENTION.# By Nicolas REISER. Translated from the Second German Edition. Crown 8vo. Sixty-three Illustrations. 170 pp. Price 5s. net. (Post free, 5s. 4d. home; 5s. 6d. abroad.) #Contents.# Improperly Chosen Raw Material or Improper Mixtures -- Wrong Treatment of the Material in Washing, Carbonisation, Drying, Dyeing and Spinning -- Improper Spacing of the Goods in the Loom -- Wrong Placing of Colours -- Wrong Weight or Width of the Goods -- Breaking of Warp and Weft Threads -- Presence of Doubles, Singles, Thick, Loose, and too Hard Twisted Threads as well as Tangles, Thick Knots and the Like -- Errors in Cross-weaving--Inequalities, _i.e._, Bands and Stripes -- Dirty Borders -- Defective Selvedges -- Holes and Buttons -- Rubbed Places -- Creases -- Spots -- Loose and Bad Colours -- Badly Dyed Selvedges -- Hard Goods -- Brittle Goods -- Uneven Goods -- Removal of Bands, Stripes, Creases and Spots. #SPINNING AND WEAVING CALCULATIONS,# especially relating to Woollens. From the German of N. REISER. Thirty-four Illustrations. Tables. 160 pp. Demy 8vo. 1904. Price 10s. 6d. net. (Post free, 10s. 10d. home; 11s. abroad.) #Contents.# Calculating the Raw Material -- Proportion of Different Grades of Wool to Furnish a Mixture at a Given Price -- Quantity to Produce a Given Length -- Yarn Calculations -- Yarn Number -- Working Calculations -- Calculating the Reed Count -- Cost of Weaving, etc. #WATERPROOFING OF FABRICS.# By Dr. S. MIERZINSKI. Crown 8vo, 104 pp. 29 Illus. Price 5s. net. (Post free, 5s. 3d. home; 5s. 4d. abroad.) #Contents.# Introduction -- Preliminary Treatment of the Fabric -- Waterproofing with Acetate of Alumina -- Impregnation of the Fabric -- Drying -- Waterproofing with Paraffin -- Waterproofing with Ammonium Cuprate -- Waterproofing with Metallic Oxides -- Coloured Waterproof Fabrics -- Waterproofing with Gelatine, Tannin, Caseinate of Lime and other Bodies -- Manufacture of Tarpaulin -- British Waterproofing Patents -- Index. #HOW TO MAKE A WOOLLEN MILL PAY.# By John MACKIE. Crown 8vo. 76 pp. Price 3s. 6d. net. (Post free, 3s. 9d. home; 3s. 10d. abroad.) #Contents.# Blends, Piles, or Mixtures of Clean Scoured Wools -- Dyed Wool Book -- The Order Book -- Pattern Duplicate Books -- Management and Oversight -- Constant Inspection of Hill Departments -- Importance of Delivering Goods to Time, Shade, Strength, etc. -- Plums. (_For "Textile Soaps and Oils" see p. 7._) #DYEING, COLOUR PRINTING, MATCHING AND DYE-STUFFS.# #THE COLOUR PRINTING OF CARPET YARNS.# Manual for Colour Chemists and Textile Printers. By David PATERSON, F.C.S. Seventeen Illustrations. 136 pp. Demy 8vo. Price 7s. 6d. net. (Post free, 7s. 10d, home; 8s. abroad.) #Contents.# Structure and Constitution of Wool Fibre -- Yarn Scouring -- Scouring Materials -- Water for Scouring -- Bleaching Carpet Yarns -- Colour Making for Yarn Printing -- Colour Printing Pastes -- Colour Recipes for Yarn Printing -- Science of Colour Mixing -- Matching of Colours -- "Hank" Printing -- Printing Tapestry Carpet Yarns -- Yarn Printing -- Steaming Printed Yarns -- Washing of Steamed Yarns -- Aniline Colours Suitable for Yarn Printing -- Glossary of Dyes and Dye-wares used in Wood Yarn Printing -- Appendix. #THE SCIENCE OF COLOUR MIXING.# A Manual intended for the use of (p. c22) Dyers, Calico Printers and Colour Chemists. By David PATERSON, F.C.S. Forty-one Illustrations, #Five Coloured Plates, and Four Plates showing Eleven Dyed Specimens of Fabrics#. 132 pp. Demy 8vo. Price 7s. 6d. net. (Post free, 7s. 10d. home; 8s. abroad.) #Contents.# Colour a Sensation; Colours of Illuminated Bodies; Colours of Opaque and Transparent Bodies; Surface Colour -- Analysis of Light; Spectrum; Homogeneous Colours; Ready Method of Obtaining a Spectrum -- Examination of Solar Spectrum; The Spectroscope and Its Construction; Colourists' Use of the Spectroscope -- Colour by Absorption: Solutions and Dyed Fabrics; Dichroic Coloured Fabrics in Gaslight -- Colour Primaries of the Scientist _versus_ the Dyer and Artist; Colour Mixing by Rotation and Lye Dyeing; Hue, Purity, Brightness; Tints; Shades, Scales, Tones, Sad and Sombre Colours -- Colour Mixing; Pure and Impure Greens, Orange and Violets; Large Variety of Shades from few Colours; Consideration of the Practical Primaries: Red, Yellow and Blue -- Secondary Colours; Nomenclature of Violet and Purple Group; Tints and Shades of Violet; Changes in Artificial Light -- Tertiary Shades; Broken Hues; Absorption Spectra of Tertiary Shades -- Appendix: Four Plates with Dyed Specimens Illustrating Text -- Index. #DYERS' MATERIALS#: An Introduction to the Examination, Evaluation and Application of the most important Substances used in Dyeing, Printing, Bleaching and Finishing. By Paul HEERMAN, Ph.D. Translated from the German by A. C. WRIGHT, M.A. (Oxon.), B.Sc. (Lond.). Twenty-four Illustrations. Crown 8vo. 150 pp. Price 5s. net. (Post free, 5s. 4d. home; 5s. 6d. abroad.) #COLOUR MATCHING ON TEXTILES.# A Manual intended for the use of Students of Colour Chemistry, Dyeing and Textile Printing. By David PATERSON, F.C.S. Coloured Frontispiece. Twenty-nine Illustrations and #Fourteen Specimens Of Dyed Fabrics#. Demy 8vo. 132 pp. Price 7s. 6d. net. (Post free, 7s. 10d. home; 8s. abroad.) #Contents.# Colour Vision and Structure of the Eye -- Perception of Colour -- Primary and Complementary Colour Sensations -- Daylight for Colour Matching -- Selection of a Good Pure Light -- Diffused Daylight, Direct Sunlight, Blue Skylight, Variability of Daylight, etc., etc. -- Matching of Hues -- Purity and Luminosity of Colours -- Matching Bright Hues -- Aid of Tinted Films -- Matching Difficulties Arising from Contrast -- Examination of Colours by Reflected and Transmitted Lights -- Effect of Lustre and Transparency of Fibres in Colour Matching -- Matching of Colours on Velvet Pile -- Optical Properties of Dye-stuffs, Dichroism, Fluorescence -- Use of Tinted Mediums -- Orange Film -- Defects of the Eye -- Yellowing of the Lens -- Colour Blindness, etc. -- Matching of Dyed Silk Trimmings and Linings and Bindings -- Its Difficulties -- Behaviour of Shades in Artificial Light -- Colour Matching of Old Fabrics, etc. -- Examination of Dyed Colours under the Artificial Lights -- Electric Arc, Magnesium and Dufton, Gardner Lights, Welsbach, Acetylene, etc. -- Testing Qualities of an Illuminant -- Influence of the Absorption Spectrum in Changes of Hue under the Artificial Lights -- Study of the Causes of Abnormal Modifications of Hue, etc. #COLOUR: A HANDBOOK OF THE THEORY OF COLOUR.# By George H. HURST, F.C.S. #With Ten Coloured Plates# and Seventy-two Illustrations. 160 pp. Demy 8vo. Price 7s. 6d. net. (Post free, 7s. 10d. home; 8s. abroad.) #Contents.# #Colour and Its Production -- Cause of Colour in Coloured Bodies -- Colour Phenomena and Theories -- The Physiology of Light -- Contrast -- Colour in Decoration and Design -- Measurement of Colour.# Reissue of #THE ART OF DYEING WOOL, SILK AND COTTON.# Translated from the French of M. HELLOT, M. MACQUER and M. le PILEUR D'APLIGNY. First Published in English in 1789. Six Plates. Demy 8vo. 446 pp. Price 5s. net. (Post free, 5s. 6d. home; 6s. abroad.) #Contents.# Part I., #The Art of Dyeing Wool and Woollen Cloth, Stuffs, Yarn, Worsted, etc.# Part II., #The Art of Dyeing Silk.# Part III., #The Art of Dyeing Cotton and Linen Thread, together with the Method of Stamping Silks, Cottons, etc.# #THE CHEMISTRY OF DYE-STUFFS.# By Dr. Georg Von GEORGIEVICS. (p. c23) Translated from the Second German Edition. 412 pp. Demy 8vo. Price 10s. 6d. net. (Post free, 11s. home; 11s. 6d. abroad.) #Contents.# Introduction -- Coal Tar -- Intermediate Products in the Manufacture of Dye-stuffs--The Artificial Dye-stuffs (Coal-tar Dyes) -- Nitroso Dye-stuffs -- Nitro Dye-stuffs -- Azo Dye-stuffs -- Substantive Cotton Dye-stuffs -- Azoxystilbene Dye-stuffs -- Hydrazones -- Ketoneimides -- Triphenylmethane Dye-stuffs -- Rosolic Acid Dye-stuffs -- Xanthene Dye-stuffs -- Xanthone Dye-stuffs -- Flavones -- Oxyketone Dye-stuffs -- Quinoline and Acridine Dye-stuffs -- Quinonimide or Diphenylamine Dye-stuffs -- The Azine Group: Eurhodines, Safranines and Indulines -- Eurhodines -- Safranines -- Quinoxalines -- Indigo -- Dye-stuffs of Unknown Constitution -- Sulphur or Sulphine Dye stuffs -- Development of the Artificial Dye-stuff Industry -- The Natural Dye-stuffs -- Mineral Colours -- Index. #THE DYEING OF COTTON FABRICS#: A Practical Handbook for the Dyer and Student. By Franklin BEECH, Practical Colourist and Chemist. 272 pp. Forty-four Illustrations of Bleaching and Dyeing Machinery. Demy 8vo. Price 7s. 6d. net. (Post free, 7s. 10d. home; 8s. abroad.) #Contents.# Structure and Chemistry of the Cotton Fibre -- Scouring and Bleaching of Cotton --Dyeing Machinery and Dyeing Manipulations -- Principles and Practice of Cotton Dyeing -- Direct Dyeing; Direct Dyeing followed by Fixation with Metallic Salts; Direct Dyeing followed by Fixation with Developers; Direct Dyeing followed by Fixation with Couplers; Dyeing on Tannic Mordant; Dyeing on Metallic Mordant; Production of Colour Direct upon Cotton Fibres; Dyeing Cotton by Impregnation with Dye-stuff Solution -- Dyeing Union (Mixed Cotton and Wool) Fabrics -- Dyeing Half Silk (Cotton-Silk, Satin) Fabrics -- Operations following Dyeing -- Washing, Soaping, Drying -- Testing of the Colour of Dyed Fabrics -- Experimental Dyeing and Comparative Dye Testing -- Index. The book contains numerous recipes for the production on Cotton Fabrics of all kinds of a great range of colours. #THE DYEING OF WOOLLEN FABRICS.# By Franklin BEECH, Practical Colourist and Chemist. Thirty-three Illustrations. Demy 8vo. 228 pp. Price 7s. 6d. net. (Post free, 7s. 10d. home; 8s. abroad.) #Contents.# The Wool Fibre -- Structure, Composition and Properties -- Processes Preparatory to Dyeing -- Scouring and Bleaching of Wool -- Dyeing Machinery and Dyeing Manipulations -- Loose Wool Dyeing, Yarn Dyeing and Piece Dyeing Machinery -- The Principles and Practice of Wool Dyeing -- Properties of Wool Dyeing -- Methods of Wool Dyeing -- Groups of Dyes -- Dyeing with the Direct Dyes -- Dyeing with Basic Dyes -- Dyeing with Acid Dyes -- Dyeing with Mordant Dyes -- Level Dyeing -- Blacks on Wool -- Reds on Wool -- Mordanting of Wool -- Orange Shades on Wool -- Yellow Shades on Wool -- Green Shades on Wool -- Blue Shades on Wool -- Violet Shades on Wool -- Brown Shades on Wool -- Mode Colours on Wool -- Dyeing Union (Mixed Cotton Wool) Fabrics -- Dyeing of Gloria -- Operations following Dyeing -- Washing, Soaping, Drying -- Experimental Dyeing and Comparative Dye Testing -- Testing of the Colour of Dyed Fabrics -- Index. #BLEACHING AND WASHING.# #A PRACTICAL TREATISE ON THE BLEACHING OF LINEN AND COTTON YARN AND FABRICS.# By L. TAILFER, Chemical and Mechanical Engineer. Translated from the French by John GEDDES McINTOSH. Demy 8vo. 303 pp. Twenty Illus. Price 12s. 6d. net. (Post free, 13s. home; 13s. 6d. abroad.) #COTTON SPINNING AND COMBING.# #COTTON SPINNING# (First Year). By Thomas THORNLEY, Spinning Master, Bolton Technical School. 160 pp. Eighty-four Illustrations. Crown 8vo. Second Impression. Price 3s. net. (Post free, 3s. 4d. home; 3s. 6d. abroad.) #Contents.# Syllabus and Examination Papers of the City and Guilds of London Institute -- Cultivation, Classification, Ginning, Baling and Mixing of the Raw Cotton -- Bale-Breakers, Mixing Lattices and Hopper Feeders -- Opening and Scutching -- Carding -- Indexes. #COTTON SPINNING# (Intermediate, or Second Year). By Thomas (p. c24) THORNLEY. 180 pp. Seventy Illustrations. Crown 8vo. Price 5s. net. (Post free, 5s. 4d. home; 5s. 6d. abroad.) #Contents.# Syllabuses and Examination Papers of the City and Guilds of London Institute -- The Combing Process -- The Drawing Frame -- Bobbin and Fly Frames -- Mule Spinning -- Ring Spinning -- General Indexes. #COTTON SPINNING# (Honours, or Third Year). By Thomas THORNLEY. 216 pp. Seventy-four Illustrations. Crown 8vo. Second Edition. Price 5s. net. (Post free, 5s. 4d. home; 5s. 6d. abroad.) #Contents.# Syllabuses and Examination Papers of the City and Guilds of London Institute -- Cotton--The Practical Manipulation of Cotton Spinning Machinery -- Doubling and Winding -- Reeling -- Warping -- Production and Costs -- Main Driving -- Arrangement of Machinery and Mill Planning -- Waste and Waste Spinning -- Indexes. #COTTON COMBING MACHINES.# By Thos. THORNLEY, Spinning Master, Technical School, Bolton. Demy 8vo. 117 Illustrations. 300 pp. Price 7s. 6d. net. (Post free, 8s. home; 8s. 6d. abroad.) #Contents.# The Sliver Lap Machine and the Ribbon Cap Machine -- General Description of the Heilmann Comber -- The Cam Shaft -- On the Detaching and Attaching Mechanism of the Comber -- Resetting of Combers -- The Erection of a Heilmann Comber -- Stop Motions: Various Calculations -- Various Notes and Discussions -- Cotton Combing Machines of Continental Make -- Index. #FLAX, HEMP AND JUTE SPINNING.# #MODERN FLAX, HEMP AND JUTE SPINNING AND TWISTING.# A Practical Handbook for the use of Flax, Hemp and Jute Spinners, Thread, Twine and Rope Makers. By Herbert R. CARTER, Mill Manager, Textile Expert and Engineer, Examiner in Flax Spinning to the City and Guilds of London Institute. Demy 8vo. 1907. With 92 Illustrations. 200 pp. Price 7s. 6d. net. (Post free, 7s. 9d. home; 8s. abroad.) #Contents.# #Raw Fibre.# -- Origin of Flax -- Hemp and Jute Fibre -- Description of the Plants -- Mode of Cultivation -- Suitable Climate and Soil -- Sowing -- Harvesting -- Rippling Flax and Hemp -- Water Retting -- Dew Retting -- Extraction of the Fibre -- Marketing the Fibre -- Bracquing -- Flax, Hemp and Jute Marks -- Comparative Prices -- Ports of Export -- Trade Centres -- Fibre Selling Conditions -- Duty on Fibre -- Fibre Exports. #Hackling.# -- Sorting and Storing the Raw Fibre -- Softening Hemp and Jute -- Jute Batching -- Cutting -- Piecing Out -- Roughing -- Hackling by Hand and Machine -- Tippling -- Sorting -- Ventilation of Hackling Rooms. #Sliver Formation.# -- Spreading Line -- Heavy Spreading System -- Good's Combined Hackle and Spreader -- Jute Breaking and Carding -- Flax and Hemp Tow Carding -- Bell Calculation -- Clock System -- Theory of Spreading. #Line and Tow Preparing.# -- Drawing and Doubling -- Draft Calculation -- Set Calculation -- Tow Combing -- Compound Systems -- Automatic Stop Motions and Independent Heads -- Details of Preparing Machinery -- Ventilation -- Humidification. #Gill Spinning.# -- Gill Spinning for Shoe Threads, Rope Yarns, Binder and Trawl Twines -- The Automatic Gill Spinner -- Rope and Reaper Yarn Numbering. #The Flax, Hemp and Jute Roving Frame.# -- Bobbin Winding -- Differential Motion -- Twist Calculation -- Practical Changing -- Rove Stock. #Dry and Half-Dry Spinning.# -- Flyer and Ring Frames -- Draft and Twist Calculation -- Bobbin Dragging -- Reaches -- Set of Breast Beam and Tin-rod. #Wet Spinning# of Flax, Hemp and Tow -- Hot and Cold Water Spinning -- Improvements in the Water Trough -- Turn off and Speed of Spindles -- Reaches -- Belting -- Band Tying -- Tape Driving -- Oiling -- Black Threads -- Cuts per Spindle -- Ventilation of the Wet Spinning Room. #Yarn Department.# -- Reeling -- Cop Winding -- Cheese and Spool Winding -- Balling Shoe Thread, Reaper Yarn, etc. -- Yarn Drying and Conditioning -- Yarn Bundling -- Yarn Baling -- Weight of Yarn -- Yarn Tables -- Duty on Yarn Imports. #Manufacture of Threads, Twines and Cords.# -- Hank Winding -- Wet and Dry Twisting -- Cabling -- Fancy Yarns -- Twine Laying -- Sizing and Polishing Threads and Twines -- Softening Threads -- Skeining Threads -- Balling Twines -- Leeson's Universal Winder -- Randing Twines -- Spooling Sewing Threads -- Comparative Prices of Flax and Hemp Cords, Lines and Threads. #Rope Making.# -- Construction of Hawsers and Cables -- Stranding -- Laying and Closing -- Compound Rope Machines -- Rules for Rope Makers -- Weight of Ropes -- Balling and Coiling Ropes. #Mechanical Department.# -- Boilers, Engines and Turbines -- Power Transmission by Belts and Ropes -- Electric Light and Power Transmission -- Fans -- Oils and Oiling -- Repairs -- Fluting. #Mill Construction.# -- Flax, Hemp and Jute Spinning Mills and Rope works -- Heating -- Roofs -- Chimneys, etc. #COLLIERIES AND MINES.# (p. c25) #RECOVERY WORK AFTER PIT FIRES.# By Robert LAMPRECHT, Mining Engineer and Manager. Translated from the German. Illustrated by Six large Plates, containing Seventy-six Illustrations. 175 pp., demy 8vo. Price 10s. 6d. net. (Post free, 10s. 10d. home; 11s. abroad.) #Contents.# #Causes of Pit Fires -- Preventive Regulations#: (1) The Outbreak and Rapid Extension of a Shaft Fire can be most reliably prevented by Employing little or no Combustible Material in the Construction of the Shaft; (2) Precautions for Rapidly Localising an Outbreak of Fire in the Shaft; (3) Precautions to be Adopted in case those under 1 and 2 Fail or Prove Inefficient. Precautions against Spontaneous Ignition of Coal. Precautions for Preventing Explosions of Fire-damp and Coal Dust. Employment of Electricity in Mining, particularly in Fiery Pits. Experiments on the Ignition of Fire-damp Mixtures and Clouds of Coal Dust by Electricity -- #Indications of an Existing or Incipient Fire -- Appliances for Working in Irrespirable Gases#: Respiratory Apparatus; Apparatus with Air Supply Pipes; Reservoir Apparatus; Oxygen Apparatus -- #Extinguishing Pit Fires#: (_a_) Chemical Means; (_b_) Extinction with Water. Dragging down the Burning Masses and Packing with Clay; (_c_) Insulating the Seat of the Fire by Dams. Dam Building. Analyses of Fire Gases. Isolating the Seat of a Fire with Dams: Working in Irrespirable Gases ("Gas-diving"): Air-Lock Work. Complete Isolation of the Pit. Flooding a Burning Section isolated by means of Dams. Wooden Dams: Masonry Dams. Examples of Cylindrical and Dome-shaped Dams. Dam Doors: Flooding the Whole Pit -- #Rescue Stations#: (_a_) Stations above Ground; (_b_) Underground Rescue Stations -- #Spontaneous Ignition of Coal in Bulk# -- Index. #VENTILATION IN MINES.# By Robert WABNER, Mining Engineer. Translated from the German. Royal 8vo. Thirty Plates and Twenty-two Illustrations. 240 pp. Price 10s. 6d. net. (Post free, 11s. home; 11s. 3d. abroad.) #Contents.# #The Causes of the Contamination of Pit Air -- The Means of Preventing the Dangers resulting from the Contamination of Pit Air -- Calculating the Volume of Ventilating Current necessary to free Pit Air from Contamination -- Determination of the Resistance Opposed to the Passage of Air through the Pit -- Laws of Resistance and Formulæ therefor -- Fluctuations in the Temperament or Specific Resistance of a Pit -- Means for Providing a Ventilating Current in the Pit -- Mechanical Ventilation -- Ventilators and Fans -- Determining the Theoretical, Initial, and True (Effective) Depression of the Centrifugal Fan -- New Types of Centrifugal Fan of Small Diameter and High Working Speed -- Utilising the Ventilating Current to the utmost Advantage and distributing the same through the Workings -- Artificially retarding the Ventilating Current -- Ventilating Preliminary Workings -- Blind Headings -- Separate Ventilation -- Supervision of Ventilation# -- INDEX. #HAULAGE AND WINDING APPLIANCES USED IN MINES.# By Carl VOLK. Translated from the German. Royal 8vo. With Six Plates and 148 Illustrations. 150 pp. Price 8s. 6d. net. (Post free, 9s. home; 9s. 3d. abroad.) #Contents.# Haulage Appliances -- Ropes -- Haulage Tubs and Tracks -- Cages and Winding Appliances -- Winding Engines for Vertical Shafts -- Winding without Ropes -- Haulage in Levels and Inclines -- The Working of Underground Engines -- Machinery for Downhill Haulage. #DENTAL METALLURGY.# #DENTAL METALLURGY: MANUAL FOR STUDENTS AND DENTISTS.# By A. B. GRIFFITHS, Ph.D. Demy 8vo. Thirty-six Illustrations. 200 pp. Price 7s. 6d. net. (Post free, 7s. 10d. home; 8s. abroad.) #Contents.# Introduction -- Physical Properties of the Metals -- Action of Certain Agents on Metals -- Alloys -- Action of Oral Bacteria on Alloys -- Theory and Varieties of Blowpipes -- Fluxes -- Furnaces and Appliances -- Heat and Temperature -- Gold -- Mercury -- Silver -- Iron -- Copper -- Zinc -- Magnesium -- Cadmium -- Tin -- Lead -- Aluminium -- Antimony -- Bismuth -- Palladium -- Platinum -- Iridium -- Nickel -- Practical Work -- Weights and Measures. #ENGINEERING, SMOKE PREVENTION AND METALLURGY.# (p. c26) #THE PREVENTION OF SMOKE.# Combined with the Economical Combustion of Fuel. By W. C. POPPLEWELL, M.Sc., A.M.Inst., C.E., Consulting Engineer. Forty-six Illustrations. 190 pp. Demy 8vo. Price 7s. 6d. net. (Post free, 7s. 10d. home; 8s. 3d. abroad.) #Contents#. Fuel and Combustion -- Hand Firing in Boiler Furnaces -- Stoking by Mechanical Means -- Powdered Fuel -- Gaseous Fuel -- Efficiency and Smoke Tests of Boilers -- Some Standard Smoke Trials -- The Legal Aspect of the Smoke Question -- The Best Means to be adopted for the Prevention of Smoke -- Index. #GAS AND COAL DUST FIRING.# A Critical Review of the Various Appliances Patented in Germany for this purpose since 1885. By Albert PÜTSCH. 130 pp. Demy 8vo. Translated from the German. With 103 Illustrations. Price 7s. 6d. net. (Post free, 7s. 10d. home; 8s. abroad.) #Contents#. Generators -- Generators Employing Steam -- Stirring and Feed Regulating Appliances -- Direct Generators -- Burners -- Regenerators and Recuperators -- Glass Smelting Furnaces -- Metallurgical Furnaces -- Pottery Furnace -- Coal Dust Firing -- Index. #THE HARDENING AND TEMPERING OF STEEL IN THEORY AND PRACTICE.# By Fridolin REISER. Translated from the German of the Third Edition. Crown 8vo. 120 pp. Price 5s. net. (Post free, 5s. 3d. home; 5s. 4d. abroad.) #Contents#. #Steel -- Chemical and Physical Properties of Steel, and their Casual Connection -- Classification of Steel according to Use -- Testing the Quality of Steel -- Steel-Hardening -- Investigation of the Causes of Failure in Hardening -- Regeneration of Steel Spoilt in the Furnace -- Welding Steel -- Index.# #SIDEROLOGY: THE SCIENCE OF IRON# (The Constitution of Iron Alloys and Slags). Translated from German of Hanns Freiherr v. JÜPTNER. 350 pp. Demy 8vo. Eleven Plates and Ten Illustrations. Price 10s. 6d. net. (Post free, 11s. home; 11s. 6d. abroad.) #Contents.# #The Theory of Solution.# -- Solutions -- Molten Alloys -- Varieties of Solutions -- Osmotic Pressure -- Relation between Osmotic Pressure and other Properties of Solutions -- Osmotic Pressure and Molecular Weight of the Dissolved Substance -- Solutions of Gases -- Solid Solutions -- Solubility -- Diffusion -- Electrical Conductivity -- Constitution of Electrolytes and Metals -- Thermal Expansion. #Micrography.# -- Microstructure -- The Micrographic Constituents of Iron -- Relation between Micrographical Composition, Carbon-Content, and Thermal Treatment of Iron Alloys -- The Microstructure of Slags. #Chemical Composition of the Alloys of Iron.# -- Constituents of Iron Alloys -- Carbon -- Constituents of the Iron Alloys, Carbon -- Opinions and Researches on Combined Carbon -- Applying the Curves of Solution deduced from the Curves of Recalescence to the Determination of the Chemical Composition of the Carbon present in Iron Alloys -- The Constituents of Iron -- Iron -- The Constituents of Iron Alloys -- Manganese -- Remaining Constituents of Iron Alloys -- A Silicon -- Gases. #The Chemical Composition of Slag.# -- Silicate Slags -- Calculating the Composition of Silicate Slags -- Phosphate Slags -- Oxide Slags -- Appendix -- Index. #EVAPORATING, CONDENSING AND COOLING APPARATUS.# Explanations, Formulæ and Tables for Use in Practice. By E. HAUSBRAND, Engineer. Translated by A. C. WRIGHT, M.A. (Oxon.), B.Sc. (Lond.). With Twenty-one Illustrations and Seventy-six Tables. 400 pp. Demy 8vo. Price 10s. 6d. net. (Post free, 11s. home; 11s. 6d. abroad.) #Contents.# (p. c27) _Re_Coefficient of Transmission of Heat, k/, and the Mean Temperature Difference, [Greek: theta]/m -- Parallel and Opposite Currents -- Apparatus for Heating with Direct Fire -- The Injection of Saturated Steam -- Superheated Steam -- Evaporation by Means of Hot Liquids -- The Transference of Heat in General, and Transference by means of Saturated Steam in Particular -- The Transference of Heat from Saturated Steam in Pipes (Coils) and Double Bottoms -- Evaporation in a Vacuum -- The Multiple-effect Evaporator -- Multiple-effect Evaporators from which Extra Steam is Taken -- The Weight of Water which must be Evaporated from 100 Kilos, of Liquor in order its Original Percentage of Dry Materials from 1-25 per cent. up to 20-70 per cent. -- The Relative Proportion of the Heating Surfaces in the Elements of the Multiple Evaporator and their Actual Dimensions -- The Pressure Exerted by Currents of Steam and Gas upon Floating Drops of Water -- The Motion of Floating Drops of Water upon which Press Currents of Steam -- The Splashing of Evaporating Liquids -- The Diameter of Pipes for Steam, Alcohol, Vapour and Air -- The Diameter of Water Pipes -- The Loss of Heat, from Apparatus and Pipes to the Surrounding Air, and Means for Preventing the Loss -- Condensers -- Heating Liquids by Means of Steam -- The Cooling of Liquids -- The Volumes to be Exhausted from Condensers by the Air-pumps -- A Few Remarks on Air-pumps and the Vacua they Produce -- The Volumetric Efficiency of Air-pumps -- The Volumes of Air which must be Exhausted from a Vessel in order to Reduce its Original Pressure to a Certain Lower Pressure -- Index. #SANITARY PLUMBING, METAL WORK, ETC., ETC.# #EXTERNAL PLUMBING WORK.# A Treatise on Lead Work for Roofs. By John W. HART, R.P.C. 180 Illustrations. 272 pp. Demy 8vo. Second Edition Revised. Price 7s. 6d. net. (Post free, 7s. 10d. home; 8s. abroad.) #Contents.# Cast Sheet Lead -- Milled Sheet Lead -- Roof Cesspools -- Socket Pipes -- Drips -- Gutters -- Gutters (continued) -- Breaks -- Circular Breaks -- Flats -- Flats (continued) -- Rolls on Flats -- Roll Ends -- Roll Intersections -- Seam Rolls -- Seam Rolls (continued) -- Tack Fixings -- Step Flashings -- Step Flashings (continued) -- Secret Gutters -- Soakers -- Hip and Valley Soakers -- Dormer Windows -- Dormer Windows (continued) -- Dormer Tops -- Internal Dormers -- Skylights -- Hips and Ridging -- Hips and Ridging (continued) -- Fixings for Hips and Ridging -- Ornamental Ridging -- Ornamental Curb Rolls -- Curb Rolls -- Cornices -- Towers and Finials -- Towers and Finials (continued) -- Towers and Finials (continued) -- Domes -- Domes (continued) -- Ornamental Lead Work -- Rain Water Heads -- Rain Water Heads (continued) -- Rain Water Heads (continued). #HINTS TO PLUMBERS ON JOINT WIPING, PIPE BENDING AND LEAD BURNING.# Third Edition, Revised and Corrected. By John W. HART, R.P.C. 184 Illustrations. 313 pp. Demy 8vo. Price 7s. 6d. net. (Post free, 8s. home; 8s. 6d. abroad.) #Contents.# Pipe Bending -- Pipe Bending (continued) -- Pipe Bending (continued) -- Square Pipe Bendings-- Half-circular Elbows -- Curved Bends on Square Pipe -- Bossed Bends -- Curved Plinth Bends -- Rain-water Shoes on Square Pipe -- Curved and Angle Bends -- Square Pipe Fixings -- Joint-wiping -- Substitutes for Wiped Joints -- Preparing Wiped Joints -- Joint Fixings -- Plumbing Irons -- Joint Fixings -- Use of "Touch" in Soldering -- Underhand Joints -- Blown and Copper Bit Joints -- Branch Joints -- Branch Joints (continued) -- Block Joints -- Block Joints (continued) -- Block Fixings -- Astragal Joints -- Pipe Fixings -- Large Branch Joints -- Large Underhand Joints -- Solders -- Autogenous Soldering or Lead Burning -- Index. #SANITARY PLUMBING AND DRAINAGE.# By John W. HART. Demy 8vo. With 208 Illustrations. 250 pp. 1904, Price 7s. 6d. net. (Post free, 7s. 10d. home; 8s. abroad.) #Contents.# Sanitary Surveys -- Drain Testing -- Drain Testing with Smoke -- Testing Drains with Water -- Drain Plugs for Testing -- Sanitary Defects -- Closets -- Baths and Lavatories -- House Drains--Manholes -- Iron Soil Pipes -- Lead Soil Pipes -- Ventilating Pipes -- Water-closets -- Flushing Cisterns -- Baths -- Bath Fittings -- Lavatories -- Lavatory Fittings -- Sinks -- Waste Pipes -- Water Supply -- Ball Valves -- Town House Sanitary Arrangements -- Drainage -- Jointing Pipes -- Accessible Drains -- Iron Drains -- Iron Junctions -- Index. #THE PRINCIPLES AND PRACTICE OF DIPPING, BURNISHING, LACQUERING (p. c28) AND BRONZING BRASS WARE.# By W. Norman BROWN. 35 pp. Crown 8vo. Price 2s. net. (Post free, 2s. 3d. home and abroad.) #A HANDBOOK ON JAPANNING AND ENAMELLING FOR CYCLES, BEDSTEADS, TINWARE, ETC.# By William Norman BROWN. 52 pp. and Illustrations. Crown 8vo. Price 2s. net. (Post free, 2s. 3d. home and abroad.) #THE PRINCIPLES OF HOT WATER SUPPLY.# By John W. HART, R.P.C. With 129 Illustrations. 177 pp., demy 8vo. Price 7s. 6d. net. (Post free, 7s. 10d. home; 8s. abroad.) #Contents.# Water Circulation -- The Tank System -- Pipes and Joints -- The Cylinder System -- Boilers for the Cylinder System -- The Cylinder System -- The Combined Tank and Cylinder System -- Combined Independent and Kitchen Boiler -- Combined Cylinder and Tank System with Duplicate Boilers -- Indirect Heating and Boiler Explosions -- Pipe Boilers -- Safety Valves -- Safety Valves -- The American System -- Heating Water by Steam -- Steam Kettles and Jets -- Heating Power of Steam -- Covering for Hot Water Pipes -- Index. #HOUSE DECORATING AND PAINTING.# #THREE HUNDRED SHADES FOR DECORATORS AND HOW TO MIX THEM.# By A. DESAINT. Quarto. The book will consist of a wide range of shades and tints suitable for decorators carefully numbered and mounted for easy reference, with full particulars as to the composition of each shade. [_In the press_.] #HOUSE DECORATING AND PAINTING.# By W. Norman BROWN. Eighty-eight Illustrations. 150 pp. Crown 8vo. Price 3s. 6d. net. (Post free, 3s. 9d, home and abroad.) #A HISTORY OF DECORATIVE ART.# By W. Norman BROWN. Thirty-nine Illustrations. 96 pp. Crown 8vo. Price 2s. 6d. net. (Post free, 2s. 9d. home and abroad.) #WORKSHOP WRINKLES# for Decorators, Painters, Paper-hangers and Others. By W. N. BROWN. Crown 8vo. 128 pp. Second Edition. Price 2s. 6d. net. (Post free, 2s. 9d. home; 2s. 10d. abroad.) #BREWING AND BOTANICAL.# #HOPS IN THEIR BOTANICAL, AGRICULTURAL AND TECHNICAL ASPECT, AND AS AN ARTICLE OF COMMERCE.# By Emmanuel GROSS, Professor at the Higher Agricultural College, Tetschen-Liebwerd. Translated from the German. Seventy-eight Illustrations. 340 pp. Demy 8vo. Price 12s. 6d. net. (Post free, 13s. home; 13s. 6d. abroad.) #Contents.# HISTORY OF THE HOP -- THE HOP PLANT -- Introductory -- The Roots -- The Stem -- and Leaves -- Inflorescence and Flower: Inflorescence and Flower of the Male Hop; Inflorescence and Flower of the Female Hop -- The Fruit and its Glandular Structure: The Fruit and Seed -- (p. c29) Propagation and Selection of the Hop -- Varieties of the Hop: (_a_) Red Hops; (_b_) Green Hops; (_c_) Pale Green Hops -- Classification according to the Period of Ripening: Early August Hops; Medium Early Hops; Late Hops -- Injuries to Growth -- Leaves Turning Yellow, Summer or Sunbrand, Cones Dropping Off, Honey Dew, Damage from Wind, Hail and Rain; Vegetable Enemies of the Hop: Animal Enemies of the Hop -- Beneficial Insects on Hops -- CULTIVATION -- The Requirements of the Hop in Respect of Climate, Soil and Situation: Climate; Soil; Situation -- Selection of Variety and Cuttings -- Planting a Hop Garden: Drainage; Preparing the Ground; Marking-out for Planting; Planting; Cultivation and Cropping of the Hop Garden in the First Year -- Work to be Performed Annually in the Hop Garden: Working the Ground; Cutting; The Non-cutting System; The Proper Performance of the Operation of Cutting: Method of Cutting: Close Cutting, Ordinary Cutting, The Long Cut, The Topping Cut; Proper Season for Cutting: Autumn Cutting, Spring Cutting; Manuring; Training the Hop Plant: Poled Gardens, Frame Training; Principal Types of Frames; Pruning, Cropping, Topping, and Leaf Stripping the Hop Plant; Picking, Drying and Bagging -- Principal and Subsidiary Utilisation of Hops and Hop Gardens -- Life of a Hop Garden; Subsequent Cropping -- Cost of Production, Yield and Selling Prices. #Preservation and Storage# -- Physical and Chemical Structure of the Hop Cone -- Judging the Value of Hops. #Statistics of Production# -- The Hop Trade -- Index. #TIMBER AND WOOD WASTE.# #TIMBER#: A Comprehensive Study of Wood in all its Aspects (Commercial and Botanical), showing the Different Applications and Uses of Timber in Various Trades, etc. Translated from the French of Paul CHARPENTIER. Royal 8vo. 437 pp. 178 Illustrations. Price 12s. 6d. net. (Post free, 13s. home; 14s. abroad.) #Contents.# #Physical and Chemical Properties of Timber# -- Composition of the Vegetable Bodies -- Chief Elements -- M. Fremy's Researches -- Elementary Organs of Plants and especially of Forests -- Different Parts of Wood Anatomically and Chemically Considered -- General Properties of Wood -- #Description of the Different Kinds of Wood# -- Principal Essences with Caducous Leaves -- Coniferous Resinous Trees -- #Division of the Useful Varieties of Timber in the Different Countries of the Globe# -- European Timber -- African Timber -- Asiatic Timber -- American Timber -- Timber of Oceania -- #Forests# -- General Notes as to Forests; their Influence -- Opinions as to Sylviculture -- Improvement of Forests -- Unwooding and Rewooding -- Preservation of Forests -- Exploitation of Forests -- Damage caused to Forests -- Different Alterations -- #The Preservation of Timber# -- Generalities -- Causes and Progress of Deterioration -- History of Different Proposed Processes -- Dessication -- Superficial Carbonisation of Timber -- Processes by Immersion -- Generalities as to Antiseptics Employed -- Injection Processes in Closed Vessels -- The Boucherie System, Based upon the Displacement of the Sap -- Processes for Making Timber Uninflammable -- #Applications of Timber# -- Generalities -- Working Timber -- Paving -- Timber for Mines -- Railway Traverses -- Accessory Products -- Gums -- Works of M. Fremy -- Resins -- Barks -- Tan -- Application of Cork -- The Application of Wood to Art and Dyeing -- Different Applications of Wood -- Hard Wood -- Distillation of Wood -- Pyroligneous Acid -- Oil of Wood -- Distillation of Resins -- Index. #THE UTILISATION OF WOOD WASTE.# Translated from the German of Ernst HUBBARD. Crown 8vo. 192 pp. Fifty Illustrations. Price 5s. net. (Post free, 5s. 4d. home; 5s. 6d. abroad.) #Contents.# General Remarks on the Utilisation of Sawdust -- Employment of Sawdust as Fuel, with and without Simultaneous Recovery of Charcoal and the Products of Distillation -- Manufacture of Oxalic Acid from Sawdust -- Process with Soda Lye; Thorn's Process; Bohlig's Process -- Manufacture of Spirit (Ethyl Alcohol) from Wood Waste -- Patent Dyes (Organic Sulphides, Sulphur Dyes, or Mercapto Dyes) -- Artificial Wood and Plastic Compositions from Sawdust -- Production of Artificial Wood Compositions for Moulded Decorations -- Employment of Sawdust for Blasting Powders and Gunpowders -- Employment of Sawdust for Briquettes -- Employment of Sawdust in the Ceramic Industry and as an Addition to Mortar -- Manufacture of Paper Pulp from Wood -- Casks -- Various Applications of Sawdust and Wood Refuse -- Calcium Carbide -- Manure -- Wood Mosaic Plaques -- Bottle Stoppers -- Parquetry -- Fire-lighters -- Carborundum -- The Production of Wood Wool -- Bark -- Index. #BUILDING AND ARCHITECTURE.# (p. c30) #THE PREVENTION OF DAMPNESS IN BUILDINGS#; with Remarks on the Causes, Nature and Effects of Saline, Efflorescences and Dry-rot, for Architects, Builders, Overseers, Plasterers Painters and House Owners. By Adolf Wilhelm KEIM. Translated from the German of the second revised Edition by M. J. SALTER, F.I.C. F.C.S. Eight Coloured Plates and Thirteen Illustrations. Crown 8vo. 115 pp. Price 5s. net. (Post free, 5s. 3d. home; 5s. 4d. abroad.) #Contents.# The Various Causes of Dampness and Decay of the Masonry of Buildings, and the Structural and Hygienic Evils of the Same -- Precautionary Measures during Building against Dampness and Efflorescence -- Methods of Remedying Dampness and Efflorescences in the Walls of Old Buildings -- The Artificial Drying of New Houses, as well as Old Damp Dwellings and the Theory of the Hardening of Mortar -- New, Certain and Permanently Efficient Methods for Drying Old Damp Walls and Dwellings -- The Cause and Origin of Dry-rot: its Injurious Effect on Health, its Destructive Action on Buildings, and its Successful Repression -- Methods of Preventing Dry-rot to be Adopted During Construction -- Old Methods of Preventing Dry-rot -- Recent and More Efficient Remedies for Dry-rot -- Index. #HANDBOOK OF TECHNICAL TERMS USED IN ARCHITECTURE AND BUILDING, AND THEIR ALLIED TRADES AND SUBJECTS.# By Augustine C. PASSMORE. Demy 8vo. 380 pp. Price 7s. 6d. net. (Post free, 8s. home; 8s. 6d, abroad.) #FOODS AND SWEETMEATS.# #THE MANUFACTURE OF PRESERVED FOODS AND SWEETMEATS.# By A. HAUSNER. With Twenty-eight Illustrations. Translated from the German of the third enlarged Edition. Crown 8vo. 225 pp. Price 7s. 6d. net. (Post free, 7s. 9d. home; 7s. 10d. abroad.) #Contents.# #The Manufacture of Conserves# -- Introduction -- The Causes of the Putrefaction of Food -- The Chemical Composition of Foods -- The Products of Decomposition -- The Causes of Fermentation and Putrefaction -- Preservative Bodies -- The Various Methods of Preserving Food -- The Preservation of Animal Food -- Preserving Meat by Means of Ice -- The Preservation of Meat by Charcoal -- Preservation of Meat by Drying -- The Preservation of Meat by the Exclusion of Air -- The Appert Method -- Preserving Flesh by Smoking -- Quick Smoking -- Preserving Meat with Salt -- Quick Salting by Air Pressure -- Quick Salting by Liquid Pressure -- Gamgee's Method of Preserving Meat -- The Preservation of Eggs -- Preservation of White and Yolk of Egg -- Milk Preservation -- Condensed Milk -- The Preservation of Fat -- Manufacture of Soup Tablets -- Meat Biscuits -- Extract of Beef -- The Preservation of Vegetable Foods in General -- Compressing Vegetables -- Preservation of Vegetables by Appert's Method -- The Preservation of Fruit -- Preservation of Fruit by Storage -- The Preservation of Fruit by Drying -- Drying Fruit by Artificial Heat -- Roasting Fruit -- The Preservation of Fruit with Sugar -- Boiled Preserved Fruit -- The Preservation of Fruit in Spirit, Acetic Acid or Glycerine -- Preservation of Fruit without Boiling -- Jam Manufacture -- The Manufacture of Fruit Jellies -- The Making of Gelatine Jellies -- The Manufacture of "Sulzen" -- The Preservation of Fermented Beverages -- #The Manufacture of Candies# -- Introduction -- The Manufacture of Candied Fruit -- The Manufacture of Boiled Sugar and Caramel -- The Candying of Fruit -- Caramelised Fruit -- The Manufacture of Sugar Sticks, or Barley Sugar -- Bonbon Making -- Fruit Drops -- The Manufacture of Dragées -- The Machinery and Appliances used in Candy Manufacture -- Dyeing Candies and Bonbons -- Essential Oils used in Candy Making -- Fruit Essences -- The Manufacture of Filled Bonbons, Liqueur Bonbons and Stamped Lozenges -- Recipes for Jams and Jellies -- Recipes for Bonbon Making -- Dragées -- Appendix -- Index. #DYEING FANCY GOODS.# (p. c31) #THE ART OF DYEING AND STAINING MARBLE, ARTIFICIAL STONE, BONE, HORN, IVORY AND WOOD, AND OF IMITATING ALL SORTS OF WOOD#. A Practical Handbook for the Use of Joiners, Turners, Manufacturers of Fancy Goods, Stick and Umbrella Makers, Comb Makers, etc. Translated from the German of D. H. SOXHLET, Technical Chemist. Crown 8vo. 168 pp. Price 5s. net. (Post free, 5s. 3d. home; 5s. 4d. abroad.) #Contents.# Mordants and Stains -- Natural Dyes -- Artificial Pigments -- Coal Tar Dyes -- Staining Marble and Artificial Stone -- Dyeing, Bleaching and Imitation of Bone, Horn and Ivory -- Imitation of Tortoiseshell for Combs: Yellows, Dyeing Nuts -- Ivory -- Wood Dyeing -- Imitation of Mahogany: Dark Walnut, Oak, Birch-Bark, Elder-Marquetry, Walnut, Walnut-Marquetry, Mahogany, Spanish Mahogany, Palisander and Rose Wood, Tortoiseshell, Oak, Ebony, Pear Tree -- Black Dyeing Processes with Penetrating Colours -- Varnishes and Polishes: English Furniture Polish, Vienna Furniture Polish, Amber Varnish, Copal Varnish, Composition for Preserving Furniture -- Index. #CELLULOID.# #CELLULOID#. 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8144	----	ACETYLENE THE PRINCIPLES OF ITS GENERATION AND USE A PRACTICAL HANDBOOK ON THE PRODUCTION, PURIFICATION, AND SUBSEQUENT TREATMENT OF ACETYLENE FOR THE DEVELOPMENT OF LIGHT, HEAT, AND POWER Second Edition REVISED AND ENLARGED BY F. H. LEEDS, F.I.C. FOR SOME YEARS TECHNICAL EDITOR OF THE JOURNAL "ACETYLENE" AND W. J. ATKINSON BUTTERFIELD, M.A. AUTHOR OF "THE CHEMISTRY OF GAS MANUFACTURE" PREFATORY NOTE TO THE FIRST EDITION In compiling this work on the uses and application of acetylene, the special aim of the authors has been to explain the various physical and chemical phenomena: (1) Accompanying the generation of acetylene from calcium carbide and water. (2) Accompanying the combustion of the gas in luminous or incandescent burners, and (3) Its employment for any purpose--(a) neat, (b) compressed into cylinders, (c) diluted, and (d) as an enriching material. They have essayed a comparison between the value of acetylene and other illuminants on the basis of "illuminating effect" instead of on the misleading basis of pure "illuminating power," a distinction which they hope and believe will do much to clear up the misconceptions existing on the subject. Tables are included, for the first time (it is believed) in English publications, of the proper sizes of mains and service-pipes for delivering acetylene at different effective pressures, which, it is hoped, will prove of use to those concerned in the installation of acetylene lighting systems. _June_ 1903 NOTE TO THE SECOND EDITION The revision of this work for a new edition was already far advanced when it was interrupted by the sudden death on April 30, 1908, of Mr. F. H. Leeds. The revision was thereafter continued single-handed, with the help of very full notes which Mr. Leeds had prepared, by the undersigned. It had been agreed prior to Mr. Leeds' death that it would add to the utility of the work if descriptions of a number of representative acetylene generators were given in an Appendix, such as that which now appears at the conclusion of this volume. Thanks are due to the numerous firms and individuals who have assisted by supplying information for use in this Appendix. W. J. ATKINSON BUTTERFIELD WESTMINSTER _August 1909_ CONTENTS CHAPTER I INTRODUCTORY--THE COST AND ADVANTAGES OF ACETYLENE LIGHTING Intrinsic advantages Hygienic advantages Acetylene and paraffin oil Blackened ceilings Cost of acetylene lighting Cost of acetylene and coal-gas Cost of acetylene and electric lighting Cost of acetylene and paraffin oil Cost of acetylene and air-gas Cost of acetylene and candles Tabular statement of costs (_to face_) Illuminating power and effect CHAPTER II THE PHYSICS AND CHEMISTRY OF THE REACTION BETWEEN CARBIDE AND WATER Nature of calcium carbide Storage of calcium carbide Fire risks of acetylene lighting Purchase of carbide Quality and sizes of carbide Treated and scented carbide Reaction between carbide and water chemical nature heat evolved difference between heat and temperature amount of heat evolved effect of heat on process of generation Reaction: effects of heat effect of heat on the chemical reaction effects of heat on the acetylene effects of heat on the carbide Colour of spent carbide Maximum attainable temperatures Soft solder in generators Reactions at low temperatures Reactions at high temperatures Pressure in generators CHAPTER III THE GENERAL PRINCIPLES OF ACETYLENE GENERATION ACETYLENE GENERATING APPARATUS Automatic and non-automatic generators Control of the chemical reaction Non-automatic carbide-to-water generators Non-automatic water-to-carbide generators Automatic devices Displacement gasholders Action of water-to-carbide generators Action of carbide-to-water generators Use of oil in generator Rising gasholder Deterioration of acetylene on storage Freezing and its avoidance Corrosion in apparatus Isolation of holder from generator Water-seals Vent pipes and safety valve Frothing in generator Dry process of generation Artificial lighting of generator sheds CHAPTER IV THE SELECTION OF AN ACETYLENE GENERATOR Points to be observed Recommendations of Home Office Committee British and Foreign regulations for the construction and installation of acetylene generating plant CHAPTER V THE TREATMENT OF ACETYLENE AFTER GENERATION Impurities in calcium carbide Impurities of acetylene Removal of moisture Generator impurities in acetylene Filters Carbide impurities in acetylene Washers Reasons for purification Necessary extent of purification Quantity of impurities in acetylene Purifying materials Bleaching powder Heratol, frankoline, acagine, and puratylene Efficiency of purifying material Minor reagent Method of a gas purifier Methods of determining exhaustion of purifying material Regulations for purification Drying Position of purifier Filtration General arrangement of plans Generator residues Disposal of residue CHAPTER VI THE CHEMICAL AND PHYSICAL PROPERTIES OF ACETYLENE Physical properties Leakage Heat of combustion Explosive limits Range of explosibility Solubility in liquids Toxicity Endothermic nature Polymerisation Heats of formation and combustion Colour of flame Radiant efficiency Chemical properties Reactions with copper CHAPTER VII MAINS AND SERVICE-PIPES--SUBSIDIARY APPARATUS Meters Governors Gasholder pressure Pressure-gauges Dimensions of mains and pipes Velocity of flow in pipes Service-pipes and mains Leakage Pipes and fittings Laying mains Expelling air from pipes Tables of pipes and mains CHAPTER VIII COMBUSTION OF ACETYLENE IN LUMINOUS BURNERS--THEIR DISPOSITION Nature of luminous flames Illuminating power Early burners Injector and twin-flame burners Illuminating power of self-luminous burners Glassware for burners CHAPTER IX INCANDESCENT BURNERS--HEATING APPARATUS--MOTORS--AUTOGENOUS SOLDERING Merits of incandescent lighting Conditions for incandescent lighting Illuminating power of incandescent burners Durability of mantles Typical incandescent burners Acetylene for heating and cooking Acetylene motors Blowpipes Autogenous soldering and welding CHAPTER X CARBURETTED ACETYLENE Carburetted acetylene Illuminating power of carburetted acetylene Carburetted acetylene for "power" CHAPTER XI COMPRESSED AND DISSOLVED ACETYLENE--MIXTURES WITH OTHER GASES Compression Dissolved acetylene Solution in acetone Liquefied acetylene Dilution with carbon dioxide Dilution with air Mixed carbides Dilution with, methane and hydrogen Self-inflammable acetylene Enrichment with acetylene Partial pressure Acetylene-oil-gas CHAPTER XII SUNDRY USES Destruction of noxious moths Destruction of phylloxera and mildew Manufacture of lampblack Production of tetrachlorethane Utilisation of residues Sundry uses for the gas CHAPTER XIII PORTABLE ACETYLENE LAMPS AND PLANT Table and vehicular lamps Flare lamps Cartridges of carbide Cycle-lamp burners Railway lighting CHAPTER XIV VALUATION AND ANALYSIS OF CARBIDE Regulations of British Acetylene Association Regulations o£ German Acetylene Association Regulations of Austrian Acetylene Association Sampling carbide Yield of gas from small carbide Correction of volumes for temperature and pressure Estimation of impurities Tabular numbers APPENDIX DESCRIPTIONS OP GENERATORS America: Canada America: United States Austria-Hungary Belgium France Germany Great Britain and Ireland INDEX INDEX TO APPENDIX ACETYLENE CHAPTER I INTRODUCTORY--THE COST AND ADVANTAGES OF ACETYLENE LIGHTING Acetylene is a gas [Footnote: For this reason the expression, "acetylene gas," which is frequently met with, would be objectionable on the ground of tautology, even if it were not grammatically and technically incorrect. "Acetylene-gas" is perhaps somewhat more permissible, but it is equally redundant and unnecessary.] of which the most important application at the present time is for illuminating purposes, for which its properties render it specially well adapted. No other gas which can be produced on a commercial scale is capable of giving, volume for volume, so great a yield of light as acetylene. Hence, apart from the advantages accruing to it from its mode of production and the nature of the raw material from which it is produced, it possesses an inherent advantage over other illuminating gases in the smaller storage accommodation and smaller mains and service-pipes requisite for the maintenance of a given supply of artificial light. For instance, if a gasholder is required to contain sufficient gas for the lighting of an establishment or district for twenty-four hours, its capacity need not be nearly so great if acetylene is employed as if oil-gas, coal-gas, or other illuminating gas is used. Consequently, for an acetylene supply the gasholder can be erected on a smaller area and for considerably less outlay than for other gas supplies. In this respect acetylene has an unquestionable economical advantage as a competitor with other varieties of illuminating gas for supplies which have generally been regarded as lying peculiarly within their preserves. The extent of this advantage will be referred to later. The advantages that accrue to acetylene from its mode of production, and the nature of the raw material from which it is obtained, are in reality of more importance. Acetylene is readily and quickly produced from a raw material--calcium carbide--which, relatively to the yield of light of the gaseous product, is less bulky than the raw materials of other gases. In comparison also with oils and candles, calcium carbide is capable of yielding, through the acetylene obtainable from it, more light per unit of space occupied by it. This higher light-yielding capacity of calcium carbide, ready to be developed through acetylene, gives the latter gas a great advantage over all other illuminants in respect of compactness for transport or storage. Hence, where facilities for transport or storage are bad or costly, acetylene may be the most convenient or cheapest illuminant, notwithstanding its relatively high cost in many other cases. For example, in a district to which coal and oil must be brought great distances, the freight on them may be so heavy that--regarding the question as simply one of obtaining light in the cheapest manner--it may be more economical to bring calcium carbide an equal or even greater distance and generate acetylene from it on the spot, than to use oil or make coal-gas for lighting purposes, notwithstanding that acetylene may not be able to compete on equal terms with oil--or coal-gas at the place from which the carbide is brought. Likewise where storage accommodation is limited, as in vehicles or in ships or lighthouses, calcium carbide may be preferable to oil or other illuminants as a source of light. Disregarding for the moment intrinsic advantages which the light obtainable from acetylene has over other lights, there are many cases where, owing to saving in cost of carriage, acetylene is the most economical illuminant; and many other cases where, owing to limited space for storage, acetylene far surpasses other illuminants in convenience, and is practically indispensable. The light of the acetylene flame has, however, some intrinsic advantages over the light of other artificial illuminants. In the first place, the light more closely resembles sunlight in composition or "colour." It is more nearly a pure "white" light than is any other flame or incandescent body in general use for illuminating purposes. The nature or composition of the light of the acetylene flame will be dealt with more exhaustively later, and compared with that afforded by other illuminants; but, speaking generally, it may be said that the self-luminous acetylene light is superior in tint, to all other artificial lights, for which reason it is invaluable for colour-judging and shade-matching. In the second place, when the gas issues from a suitable self-luminous burner under proper pressure, the acetylene flame is perfectly steady; and in this respect it in preferable to most types of electric light, to all self- luminous coal-gas flames and candles, and to many varieties of oil-lamp. In steadiness and freedom from flicker it is fully equal to incandescent coal-gas light, but it in distinctly superior to the latter by virtue of its complete freedom from noise. The incandescent acetylene flame emits a slight roaring, but usually not more than that coming from an atmospheric coal-gas burner. With the exception of the electric arc, self-luminous acetylene yields a flame of unsurpassed intensity, and yet its light is agreeably soft. In the third place, where electricity is absent, a brilliancy of illumination which can readily be obtained from self-luminous acetylene can otherwise only be procured by the employment of the incandescent system applied either to coal-gas or to oil; and there are numerous situations, such as factories, workshops, and the like, where the vibration of the machinery or the prevalence of dust renders the use of mantles troublesome if not impossible. Anticipating what will be said later, in cases like these, the cost of lighting by self-luminous acetylene may fairly be compared with self-luminous coal- gas or oil only; although in other positions the economy of the Welsbach mantle must be borne in mind. Acetylene lighting presents also certain important hygienic advantages over other forms of flame lighting, in that it exhausts, vitiates, and heats the air of a room to a less degree, for a given yield of light, than do either coal-gas, oils, or candles. This point in favour of acetylene is referred to here only in general terms; the evidence on which the foregoing statement is based will be recorded in a tabular comparison of the cost and qualities of different illuminants. Exhaustion of the air means, in this connexion, depletion of the oxygen normally present in it. One volume of acetylene requires 2-1/2 volumes of oxygen for its complete combustion, and since 21 volumes of oxygen are associated in atmospheric air with 79 volumes of inert gases--chiefly nitrogen--which do not actively participate in combustion, it follows that about 11.90 volumes of air are wholly exhausted, or deprived of oxygen, in the course of the combustion of one volume of acetylene. If the light which may be developed by the acetylene is brought into consideration, it will be found that, relatively to other illuminants, acetylene causes less exhaustion of the air than any other illuminating agent except electricity. For instance, coal-gas exhausts only about 6- 1/2 times its volume of air when it is burnt; but since, volume for volume, acetylene ordinarily yields from three to fifteen times as much light as coal-gas, it follows that the same illuminative value is obtainable from acetylene by considerably less exhaustion of the air than from coal-gas. The exact ratio depends on the degree of efficiency of the burners, or of the methods by which light is obtained from the gases, as will be realised by reference to the table which follows. Broadly speaking, however, no illuminant which evolves light by combustion (oxidation), and which therefore requires a supply of oxygen or air for its maintenance, affords light with so little exhaustion of the air as acetylene. Hence in confined, ill-ventilated, or crowded rooms, the air will suffer less exhaustion, and accordingly be better for breathing, if acetylene is chosen rather than any other illuminant, except electricity. Next, in regard to vitiation of the air, by which is meant the alteration in its composition resulting from the admixture of products of combustion with it. Electric lighting is as superior to other modes of lighting in respect of direct vitiation as of exhaustion of the air, because it does not depend on combustion. Putting it aside, however, light is obtainable by means of acetylene with less attendant vitiation of the air than by means of any other gas or of oil or candles. The principal vitiating factor in all cases is the carbonic acid produced by the combustion. Now one volume of acetylene on combustion yields two volumes of carbonic acid, whereas one volume of coal-gas yields about 0.6 volume of carbonic acid. But even assuming that the incandescent system of lighting is applied in the case of coal-gas and not of acetylene, the ratio of the consumption of the two gases for the development of a given illuminative effect will be such that no more carbonic acid will be produced by the acetylene; and if the incandescent system is applied either in both cases or in neither, the ratio will be greatly in favour of acetylene. The other factors which determine the vitiation of the air of a room in which the gas is burning are likewise under ordinary conditions more in favour of acetylene. They are not, however, constant, since the so-called "impurities," which on combustion cause vitiation of the air, vary greatly in amount according to the extent to which the gases have been purified. London coal-gas, which was formerly purified to the highest degree practically attainable, used to contain on the average only 10 to 12 grains of sulphur per 100 cubic feet, and virtually no other impurity. But now coal-gas, in London and most provincial towns, contains 40 to 50 grains of sulphur per 100 cubic foot. At least 5 grains of ammonia per 100 cubic foot in also present in coal-gas in some towns. Crude acetylene also contains sulphur and ammonia, that coming from good quality calcium carbide at the present day including about 31 grains of the former and 25 grains of the latter per 100 cubic feet. But crude acetylene is also accompanied by a third impurity, viz., phosphoretted hydrogen or phosphine, which in unknown in coal-gas, and which is considerably more objectionable than either ammonia or sulphur. The formation, behaviour, and removal of those various impurities will be discussed in Chapter V.; but here it may be said that there is no reason why, if calcium carbide of a fair degree of purity has been used, and if the gas has been generated from it in a properly designed and smoothly working apparatus-- this being quite as important as, or even more important than, the purity of the original carbide--the gas should not be freed from phosphorus, sulphur, and ammonia to the utmost necessary or desirable extent, by processes which are neither complicated nor expensive. And if this is done, as it always should be whenever the acetylene is required for domestic lighting, the vitiation of the air of a room due to the "impurities" in the gas will become much less in the case of acetylene than in that of even well-purified coal-gas; taking equal illuminating effect as the basis for comparison. Acetylene is similarly superior, speaking generally, to petroleum in respect of impurities, though the sulphur present in petroleum oils, such as are sold in this country for household use, though very variable, is often quite small in amount, and seldom is responsible for serious vitiation of the atmosphere. Regarding somewhat more closely the relative convenience and safety of acetylene and paraffin for the illumination of country residences, it may be remarked that an extraordinarily great amount of care must be bestowed upon each separate lamp if the whole house is to be kept free from an odour which is very offensive to the nostrils; and the time occupied in this process, which of itself is a disagreeable one, reaches several hours every day. Habit has taught the country dweller to accept as inevitable this waste of time, and largely to ignore the odour of petroleum in his abode; but the use of acetylene entirely does away with the daily cleaning of lamps, and, if the pipe-fitting work has been done properly, yields light absolutely unaccompanied by smell. Again, unless most carefully managed, the lamp-room of a large house, with its store of combustible oil, and its collection of greasy rags, must unavoidably prove a sensible addition to the risk of fire. The analogue of the lamp- room when acetylene is employed is the generator-house, and this is a separate building at some distance from the residence proper. There need be no appreciable odour in the generator-house, except during the times of charging the apparatus; but if there is, it passes into the open air instead of percolating into the occupied apartments. The amount of heat developed by the combustion of acetylene also is less for a given yield of light than that developed by most other illuminants. The gas, indeed, is a powerful heating gas, but owing to the amount consumed being so small in proportion to the light developed, the heat arising from acetylene lighting in a room is less than that from most other illuminating agents, if the latter are employed to the extent required to afford equally good illumination. The ratio of the heat developed in acetylene lighting to that developed in, _e.g._, lighting by ordinary coal-gas, varies considerably according to the degree of efficiency of the burners, or, in other words, of the methods by which light is obtained from the gases. Volume for volume, acetylene yields on combustion about three and a half times as much heat as coal- gas, yet, owing to its superior efficiency as an illuminant, any required light may be obtained through it with no greater evolution of heat than the best practicable (incandescent) burners for coal-gas produce. The heat evolved by acetylene burners adequate to yield a certain light is very much less than that evolved by ordinary flat-flame coal-gas burners or by oil-lamps giving the same light, and is not more than about three times as much as that from ordinary electric lamps used in numbers sufficient to give the same light. More exact figures for the ratio between the heat developed in acetylene lighting and that in other modes of lighting are given in the table already referred to. In connexion with the smaller amount of heat developed per unit of light when acetylene is the illuminant, the frequently exaggerated claim that acetylene does not blacken ceilings at all may be studied. Except it be a carelessly manipulated petroleum-lamp, no form of artificial illuminant employed nowadays ever emits black smoke, soot, or carbon, in spite of the fact that all luminous flames commercially capable of utilisation do contain free carbon in the elemental state. The black mark on a ceiling over a source of light is caused by a rising current of hot air and combustion products set up by the heat accompanying the light, which current of hot gas carries with it the dust and dirt always present in the atmosphere of an inhabited room. As this current of air and burnt gas travels in a fairly concentrated vertical stream, and as the ceiling is comparatively cool and exhibits a rough surface, that dust and dirt are deposited on the ceiling above the flame, but the stain is seldom or never composed of soot from the illuminant itself. Proof of this statement may be found in the circumstance that a black mark is eventually produced over an electric glow-lamp and above a pipe delivering hot water. Clearly, therefore, the depth and extent of the mark will depend on the volume and temperature of the hot gaseous current; and since per unit of light acetylene emits a far smaller quantity of combustion products and a far smaller amount of heat than any other flame illuminant except incandescent coal-gas, the inevitable black mark over its flame takes very much longer to appear. Quite roughly speaking, as may be deduced from what has already been said on this subject, the luminous flame of acetylene "blackens" a ceiling at about the same rate as a coal-gas burner of the best Welsbach type. There is one respect in which acetylene and other flame illuminants are superior to electric lighting, viz., that they sterilise a larger volume of air. All the air which is needed to support combustion, as well as the excess of air which actually passes through the burner tube and flame in incandescent burners, is obviously sterilised; but so also is the much larger volume of air which, by virtue of the up-current due to the heat of the flame, is brought into anything like close proximity with the light. The electric glow-lamp, and the most popular and economical modern enclosed electric arc-lamp, sterilise only the much smaller volume of air which is brought into direct contact with their glass bulbs. Moreover, when large numbers of persons are congregated in insufficiently ventilated buildings--and many public rooms are insufficiently ventilated--the air becomes nauseous to inspire and positively detrimental to the health of delicate people, by reason of the human effluvia which arise from soiled raiment and uncleansed or unhealthy bodies, long before the proportion of carbonic acid by itself is high enough to be objectionable. Thus a certain proportion of carbonic acid coming from human lungs and skin is more harmful than the same proportion of carbonic acid derived from the combustion of gas or oil. Hence acetylene and flame illuminants generally have the valuable hygienic advantages over electric lighting, not only of killing a far larger number of the micro-organisms that may be present in the air, but, by virtue of their naked flames, of burning up and destroying a considerable quantity of the aforesaid odoriferous matter, thus relieving the nose and materially assisting in the prevention of that lassitude and anæmia occasionally follow the constant inspiration of air rendered foul by human exhalations. The more important advantages of acetylene as an illuminant have now been indicated, and it remains to discuss the cost of acetylene lighting in comparison with other modes of procuring artificial light. At the outset it may be stated that a very much greater reduction in the price of calcium carbide--from which acetylene is produced--than is likely to ensue under the present methods and conditions of manufacture will be required to make acetylene lighting as cheap as ordinary gas lighting in towns in this country, provided incandescent burners are used for the gas. On the score of cheapness (and of convenience, unless the acetylene were delivered to the premises from some central generating station) acetylene cannot compete as an illuminant with coal-gas where the latter costs, say, not more than 5s. per 1000 cubic feet, if only reasonable attention is given to the gas-burners, and at least a quarter of them are on the incandescent system. If, on the other hand, coal-gas is misused and wasted through the employment only of interior or worn-out flat-flame burners, while the best types of burner are used for acetylene, the latter gas may prove as cheap for lighting as coal-gas at, say, 2s. 6d. per 1000 cubic feet (and be far better hygienically); whereas, contrariwise, if coal-gas is used only with good and properly maintained incandescent burners, it may cost over 10s. per 1000 cubic feet, and be cheaper than acetylene burned in good burners (and as good from the hygienic standpoint). More precise figures on the relative costs of coal-gas lighting and acetylene lighting are given in the tabular statement at the close of this chapter. With regard to electric lighting it is somewhat difficult to lay down a fair basis of comparison, owing to the wide variations in the cost of current, and in the efficiency of lamps, and to the undoubted hygienic and aesthetic claims of electric lighting to precedence. But in towns in this country where there is a public electricity supply, electric lighting will be used rather than acetylene for the same reasons that it is preferred to coal-gas. Cost is only a secondary consideration in such cases, and where coal-gas is reasonably cheap, and nevertheless gives place to electric lighting, acetylene clearly cannot hope to supplant the latter. [Footnote: Where, however, as is frequently the case with small public electricity-supply works, the voltage of the supply varies greatly, the fluctuations in the light of the lamps, and the frequent destruction of fuses and lamps, are such manifest inconveniences that acetylene is in fact now being generally preferred to electric lighting in such circumstances.] But where current cannot be had from an electricity-supply undertaking, and it is a question, in the event of electric lighting being adopted, of generating current by driving a dynamo, either by means of a gas-engine supplied from public gas-mains, by means of a special boiler installation, or by means of an oil-engine or of a power gas-plant and gas-engine, the claims of acetylene to preference are very strong. An important factor in the estimation of the relative advantages of electricity and acetylene in such cases is the cost of labour in looking after the generating plant. Where a gas-engine supplied from public gas-mains is used for driving the dynamo, electric lighting can be had at a relatively small expenditure for attendance on the generating plant. But the cost of the gas consumed will be high, and actually light could be obtained directly from the gas by means of incandescent mantles at far loss cost than by consuming the gas in a motor for the indirect production of light by means of electric current. Therefore electric lighting, if adopted under these conditions, must be preferred to gas lighting from considerations which are deemed to outweigh those of a much higher cost, and acetylene does not present so great advantages over coal-gas as to affect the choice of electric lighting. But in the cases where there is no public gas-supply, and current must be generated from coal or coke or oil consumed on the spot, the cost of the skilled labour required to look after either a boiler, steam-engine and dynamo, or a power gas-plant and gas-engine or oil- engine and dynamo, will be so heavy that unless the capacity of the installation is very great, acetylene will almost certainly prove a cheaper and more convenient method of obtaining light. The attention required by an acetylene installation, such as a country house of upwards of thirty rooms would want, is limited to one or two hours' labour per diem at any convenient time during daylight. Moreover, the attendant need not be highly paid, as he will not have required an engineman's training, as will the attendant on an electric lighting plant. The latter, too, must be present throughout the hours when light is wanted unless a heavy expenditure has been incurred on accumulators. Furthermore, the capital outlay on generating plant will be very much less for acetylene than for electric lighting. General considerations such as these lead to the conclusion that in almost all country districts in this country a house or institution could be lighted more cheaply by means of acetylene than by electricity. In the tabular statement of comparative costs of different modes of lighting, electric lighting has been included only on the basis of a fixed cost per unit, as owing to the very varied cost of generating current by small installations in different parts of the country it would be futile to attempt to give the cost of electric lighting on any other basis, such as the prime cost of coal or coke in a particular district. Where current is supplied by a public electricity- supply undertaking, the cost per unit is known, and the comparative costs of electric light and acetylene can be arrived at with tolerable precision. It has not been thought necessary to include in the tabular statement electric arc-lamps, as they are only suitable for the lighting of large spaces, where the steadiness and uniformity of the illumination are of secondary importance. Under such conditions, it may be stated parenthetically, the electric arc-light is much less costly than acetylene lighting would be, but it is now in many places being superseded by high-pressure gas or oil incandescent lights, which are steady and generally more economical than the arc light. The illuminant which acetylene is best fitted to supersede on the score of convenience, cleanliness, and hygienic advantages is oil. By oil is meant, in this connection, the ordinary burning petroleum, kerosene, or paraffin oil, obtained by distilling and refining various natural oils and shales, found in many countries, of which the United States (principally Pennsylvania), Russia (the Caucasus chiefly), and Scotland are practically the only ones which supply considerable quantities for use in Great Britain. Attempts are often made to claim superiority for particular grades of these oils, but it may be at once stated that so for as actual yield of light is concerned, the same weight of any of the commercial oils will give practically the same result. Hence in the comparative statement of the cost of different methods of lighting, oil will be taken at the cheapest rate at which it could ordinarily be obtained, including delivery charges, at a country house, when bought by the barrel. This rate at the present time is about ninepence per gallon. A higher price may be paid for grades of mineral oil reputed to be safer or to give a "brighter" or "clearer" light; but as the quantity of light depends mainly upon the care and attention bestowed on the burner and glass fittings of the lamp, and partly upon the employment of a suitable wick, while the safety of each lamp depends at least as much upon the design of that lamp, and the accuracy with which the wick fits the burner tube, as upon the temperature at which the oil "flashes," the extra expense involved in burning fancy-priced oils will not be considered here. The efficiency (_i.e._, the light yielded per pint or other unit volume consumed) of oil-lamps varies greatly, and, speaking broadly, increases with the power of the lamp. But as large or high-power lamps are not needed throughout a house, it is fairer to assume that the light obtainable from oil in ordinary household use is the mean of that afforded by large and that afforded by small lamps. A large oil-lamp as commonly used in country houses will give a light of about 20 candle- power, while a convenient small lamp will give a light of not more than about 5 candle-power. The large lamp will burn about 55 hours for every gallon of oil consumed, or give an illuminating duty of about 1100 candle-hours (_i.e._, the product of candle-power by burning-hours) per gallon. The small lamp, on the other hand, will burn about 140 hours for every gallon of oil consumed, or give an illuminating duty of about 700 candle-hours per gallon. Actually large lamps would in most country houses be used only in the entrance hall, living-rooms, and kitchen, while passages and minor rooms on the lower floors would be lighted by small lamps. Hence, making due allowance for the lower rate of consumption of the small lamps, it will be seen that, given equal numbers of large and small lamps in use, the mean illuminating duty of a gallon of oil as burnt in country houses will be 987, or, in round figures, 990 candle-hours. Usually candles are used in the bedrooms of country houses where the lower floors are lighted by means of petroleum lamps; but when acetylene is installed in such a house it will frequently be adopted in the principal bed- and dressing-rooms as well as in the living-rooms, as, unless candles are employed very lavishly, they are really totally inadequate to meet the reasonable demands for light of, _e.g._, a lady dressing for dinner. Where acetylene displaces candles as well as lamps in a country house, it is necessary, in comparing the cost of the new illuminant with that of the candles and oil, to bear in mind the superior degree of illumination which is secured in all rooms, at least where candles were formerly used. In regard to exhaustion and vitiation of the air, and to heat evolved, self-luminous petroleum lamps stand on much the same footing as coal-gas when the latter is burned in flat-flame burners, if the comparison is based on a given yield of light. A large lamp, owing to its higher illuminating efficiency, is better in this respect than a small one-- light for light, it is more hygienic than ordinary flat-flame coal-gas burners, while a small lamp is less hygienic. It will therefore be understood at once, from what has already been said about the superiority on hygienic grounds of acetylene to flat-flame coal-gas lighting, that acetylene is in this respect far superior to petroleum lamps. The degree of its superiority is indicated more precisely by the figures quoted in the tabular statement which concludes this chapter. Before giving the tabular statement, however, it is necessary to say a few words in regard to one method of lighting which, may possibly develop into a more serious competitor with acetylene for the lighting of the better class of country house than any of the illuminating agents and modes of lighting so far referred to. The method in question is lighting by so-called air-gas used for raising mantles to incandescence in upturned or inverted burners of the Welsbach-Kern type. "Air-gas" is ordinary atmospheric air, more or less completely saturated with the vapour of some highly volatile hydrocarbon. The hydrocarbons practically applied have so far been only "petroleum spirit" or "carburine," and "benzol." "Petroleum spirit" or "carburine" consists of the more highly volatile portion of petroleum, which is removed by distillation before the kerosene or burning oil is recovered from the crude oil. Several grades of this highly volatile petroleum distillate are distinguished in commerce; they differ in the temperature at which they begin to distil and the range of temperature covered by their distillation, and, speaking more generally, in their degree of volatility, uniformity, and density. If the petroleum distillate is sufficiently volatile and fairly uniform in character, good air-gas may be produced merely by allowing air to pass over an extended surface of the liquid. The vapour of the petroleum spirit is of greater density than air, and hence, if the course of the air-gas is downward from the apparatus at which it is produced, the flow of air into the apparatus and over the surface of the spirit will be automatically maintained by the "pull" of the descending air-gas when once the flow has been started until the outlet for the air-gas is stopped or the spirit in the apparatus is exhausted. Hence, if the apparatus for saturating air with the vapour of the light petroleum is placed well above all the points at which the air-gas is to be burnt-- _e.g._, on the roof of the house--the production of the air-gas may by simple devices become automatic, and the only attention the apparatus will require will be the replenishing of its reservoir from time to time with light petroleum. But a number of precautions are required to make this simple process operate without interruption or difficulty. For instance, the evaporation of the spirit must not be so rapid relatively to its total bulk as to lower its temperature, and thereby that of the overflowing air, too much; the reservoir must be protected from extreme cold and extreme heat; and the risk of fire from the presence of a highly volatile and highly inflammable liquid on or near the roof of the house must be met. This risk is one to which fire insurance companies take exception. More commonly, however, air-gas is made non-automatically, or more or less automatically by the employment of some mechanical means. The light petroleum, benzol, or other suitable volatile hydrocarbon is volatilised, where necessary, by the application of gentle heat, while air is driven over or through it by means of a small motor, which in some cases is a hot-air engine operated by heat supplied by a flame of the air-gas produced. These air-gas producers, or at least the reservoir of volatile hydrocarbon, may be placed in an outbuilding, so that the risk of fire in the house itself is minimised. They require, however, as much attention as an acetylene generator, usually more. It is difficult to give reliable data as to the cost of air-gas, inclusive of the expenses of production. It varies considerably with the description of hydrocarbon employed, and its market price. Air-gas is only slightly inferior hygienically to acetylene, and the colour of its light is that of the incandescent light as produced by coal-gas or acetylene. Air-gas of a certain grade may be used for lighting by flat-flame burners, but it has been available thus for very many years, and has failed to achieve even moderate success. But the advent of the incandescent burner has completely changed its position relatively to most other illuminants, and under certain conditions it seems likely to be the most formidable competitor with acetylene. Since air-gas, and the numerous chemically identical products offered under different proprietary names, is simply atmospheric air more or less loaded with the vapour of a volatile hydrocarbon which is normally liquid, it possesses no definite chemical constitution, but varies in composition according to the design of the generating plant, the atmospheric temperature at the time of preparation, the original degree of volatility of the hydrocarbon, the remaining degree of volatility after the more volatile portions have been vaporised, and the speed at which the air is passed through the carburettor. The illuminating power and the calorific value of air-gas, unless the manufacture is very precisely controlled, are apt to be variable, and the amount of light, emitted, either in self-luminous or in incandescent burners, is somewhat indeterminate. The generating plant must be so constructed that the air cannot at any time be mixed with as much hydrocarbon vapour as constitutes an explosive mixture with it, otherwise the pipes and apparatus will contain a gas which will forthwith explode if it is ignited, _i.e._, if an attempt is made to consume it otherwise than in burners with specially small orifices. The safely permissible mixtures are (1) air with less hydrocarbon vapour than constitutes an explosive mixture, and (2) air with more hydrocarbon vapour than constitutes an explosive mixture. The first of these two mixtures is available for illuminating purposes only with incandescent mantles, and to ensure a reasonable margin of safety the mixing apparatus must be so devised that the proportion of hydrocarbon vapour in the air-gas can never exceed 2 per cent. From Chapter VI. it will be evident that a little more than 2 per cent. of benzene, pentane or benzoline vapour in air forms an explosive mixture. What is the lowest proportion of such vapours in admixture with air which will serve on combustion to maintain a mantle in a state of incandescence, or even to afford a flame at all, does not appear to have been precisely determined, but it cannot be much below 1- 1/2 per cent. Hence the apparatus for producing air-gas of this first class must be provided with controlling or governing devices of such nicety that the proportion of hydrocarbon vapour in the air-gas is maintained between about 1-1/2 and 2 per cent. It is fair to say that in normal working conditions a number of devices appear to fulfil this requirement satisfactorily. The second of the two mixtures referred to above, viz., air with more hydrocarbon vapour than constitutes an explosive mixture, is primarily suitable for combustion in self-luminous burners, but may also be consumed in properly designed incandescent burners. But the generating apparatus for such air-gas must be equipped with some governing or controlling device which will ensure the proportion of hydrocarbon vapour in the mixture never falling below, say, 7 per cent. On the other hand, if saturation of the air with the vapour is practically attained, should the temperature of the gas fall before it arrives at the point of combustion, part of the spirit will condense out, and the product will thus lose part of its illuminating or calorific intensity, besides partially filling the pipes with liquid products of condensation. The loss of intensity in the gas during cold weather may or may not be inconvenient according to circumstances; but the removal of part of the combustible material brings the residual air-gas nearer to its limit of explosibility--for it is simply a mixture of combustible vapour with air, which, normally, is not explosive because the proportion of spirit is too high--and thus, when led into an atmospheric burner, the extra amount of air introduced at the injector jets may cause the mixture to be an explosive mixture of air and spirit, so that it will take fire within the burner tube instead of burning quietly at the proper orifice. This matter will be made clearer on studying what is said about explosive limits in Chapter VI., and what is stated about incandescent acetylene (carburetted or not) in Chapters IX. and X. Clearly, however, high-grade air-gas is only suitable for preparation at the immediate spot where it is to be consumed; it cannot be supplied to a complete district unless it is intentionally made of such lower intensity that the proportion of spirit is too small ever to allow of partial deposition in the mains during the winter. It is perhaps necessary to refer to the more extended use of candles for lighting in some few houses in which lamps are disliked on aesthetic, or, in some cases, ostensibly on hygienic grounds. Candle lighting, speaking broadly, is either very inadequate so far as ordinary living-rooms are concerned, or, if adequate, is very costly. Tests specially carried out by one of the authors to determine some of the figures required in the ensuing table show that ordinary paraffin or "wax" candles usually emit about 20 per cent. more light than that given by the standard spermaceti candle, whose luminosity is the unit by which the intensity of other lights is reckoned in Great Britain; and also that the light so emitted by domestic candles is practically unaffected by the sizes--"sixes," "eights," or "twelves"--burnt. In the sizes examined the light evolved has varied between 1.145 and 1.298 "candles," perhaps tending to increase slightly with the diameter of the candle tested. Hence, to obtain illumination in a room equal on the average to that afforded by 100 standard candles, or some other light or lights aggregating 100 candle- power, would require the use of only 80 to 85 ordinary paraffin, ozokerite, or wax candles. But actually the essential objects in a room could be equally well illuminated by, say, 30 candles well distributed, as by two or three incandescent gas-burners, or four or five large oil- lamps. Lights of high intensity, such as powerful gas-burners or oil- lamps, must give a higher degree of illumination in their immediate vicinity than is really necessary, if they are to illuminate adequately the more distant objects. The dissemination and diffusion of their light can be greatly aided by suitable colouring of ceilings, walls and drapings; but unless the illumination by means of lights of relatively high intensity is made almost wholly indirect, candles or other lights of low intensity, such as small electric glow-lamps, can, by proper distribution, be made to give more uniform or more suitably apportioned illumination. In this respect candles have an economical and, in some measure, a material advantage over acetylene also. (But when the method of lighting is by flames--candle or other--the multiplication of the number of units which is involved when they are of low intensity, seriously increases the risk of fire through accidental contact of inflammable material with any one of the flames. This risk is much greater with naked flames, such as candles, than with, say, inverted incandescent gas flames, which are to all intents and purposes fully protected by a closed glass globe.) Hence, in the tabular statement which follows of the comparative cost, &c., of different illuminants, it will be assumed that 30 good candles would in practice be equally efficient in regard to the illumination of a room as large oil-lamps, acetylene flames, or incandescent gas-burners aggregating 100 candle-power. For the same reason it will be assumed that electric glow-lamps of low intensity (nominally of 8 candle-power or less), aggregating 70-80 candle-power, will practically serve, if suitably distributed, equally as well as 100 candle-power obtained from more powerful sources of light. Electric glow-lamps of a nominal intensity of 16 candles or thereabouts, and good flat-flame gas-burners, aggregating 90-95 candle-power, will similarly be taken as equivalent, if suitably distributed, to 100 candle- power from more powerful sources of light. Of the latter it will be assumed that each source has an intensity between 20 and 30 candle-power, such as is afforded by a large oil-lamp, a No. 1 Welsbach-Kern upturned, or a "Bijou" inverted incandescent gas-burner, or a 0.70-cubic-foot-per- hour acetylene burner. Either of these sources of light, when used in sufficient numbers, so that with proper distribution they light a room adequately, will be taken in the tabular statement which follows as affording, per candle-power evolved, the standard illuminating effect required in that room. The same illuminating effect will be regarded as attainable by means of candles aggregating only 35 per cent., or small electric glow-lamps aggregating 77 per cent., or large electric glow- lamps and flat-flame gas-burners aggregating 90 to 95 per cent. of this candle-power; while if sources of light of higher intensity are used, such as Osram or Tantalum electric lamps, or the larger incandescent gas- burners (the Welsbach "C" or "York," or the Nos. 3 or 4 Welsbach-Kern upturned, or the No. 1 or larger size inverted burners) or incandescent acetylene burners, it will be assumed that their aggregate candle-power must be in excess by about 15 per cent., in order to compensate for the impossibility of obtaining equally well distributed illumination. These assumptions are based on general considerations and data as to the effect of sources of light of different intensities in giving practically the same degree of illumination in a room; it would occupy too much space here to discuss more fully the grounds on which they have been made. It must suffice to say that they have been adopted with the object of being perfectly fair to each means of illumination. COST PER HOUR AND HYGIENIC EFFECT OF LIGHTING BY DIFFERENT MEANS The data (except in the column headed "cost per 100 candle-hours") refer to the illumination afforded by medium-sized (0.5 to 0.7 cubic foot per hour) acetylene burners yielding together a light of about 100 candle- power, and to the approximately equivalent illumination as afforded by other means of illumination, when the lighting-units or sources of light are rationally distributed. Interest and depreciation charges on the outlay on piping or wiring a house, on brackets, fittings, lamps, candelabra, and storage accommodation (for carbide and oil) have been taken as equivalent for all modes of lighting, and omitted in computing the total cost. The cost of labour for attendance on acetylene plant, oil lamps, and candles is an uncertain and variable item--approximately equal for all these modes of lighting, but saved in coal-gas and electric lighting from public supply mains. ______________________________________________________________________ | | | | | | | | | |Candle- | Number |Aggregate| Cost | | | |Power of| of | Candle- | per | | | Description of | each |Lighting | Power | 100 | |Illuminant. | Burner or Lamp. |Lighting| Units |Afforded.|Candle-| | | | Unit. |Required.|(About.) |Hours. | | | |(About.)| | |Pence. | |____________|____________________|________|_________|_________|_______| | | | | | | | | |Self-luminous; 0.5 | | | | | | | cubic foot per hour| 18 | 5 | 90 | 1.11 | | |Self-luminous; 0.7 | | | | | | Acetylene | cubic foot per hour| 27 | 4 | 108 | 1.02 | | |Self-luminous; 1.0 | | | | | | | cubic foot per hour| 45.5 | 3 | 136 | 0.85 | | |Incandescent; 0.5 | | | | | | | cubic foot per hour| 50 | 3 | 150 | 0.49 | |____________|____________________|________|_________|_________|_______| | | | | | | | | Petroleum | Large lamp . . . . | 20 | 5 | 100 | 0.84 | | (paraffin | | | | | | | oil) | Small lamp . . . . | 5 | 14 | 70 | 1.31 | |____________|____________________|________|_________|_________|_______| | | | | | | | | |Flat flame (bad) 5 | | | | | | | cubic feet per hour| 8 | 10 | 80 | 3.75 | | |Flat flame (good) 6 | | | | | | Coal Gas | cubic feet per hour| 16 | 6 | 96 | 2.25 | | |Incandescent (No. 1 | | | | | | | Kern or Bijou In- | 25 | 4 | 100 | 0.38 | | | verted); 1-1/2 | | | | | | | cubic feet per hour| | | | | |____________|____________________|________|_________|_________|_______| | | | | | | | | Candles |"Wax" (so-called) . | 1.2 | 30 | 35 | 6.14 | |____________|____________________|________|_________|_________|_______| | | | | | | | | | Small glow . . . . | 7 | 11 | 77 | 2.81 | | | Large glow . . . . | 13 | 7 | 91 | 2.90 | | Electricity| | | | | | | | Tantalum . . . . . | 19 | 5 | 95 | 1.52 | | | Osram . . . . . . | 14 | 7 | 98 | 1.00 | |____________|____________________|________|_________|_________|_______| ___________________________________________________________________ | | | | | | | | | | | | | | Equivalent | | | Description of | Assumed Cost | Illumin- | |Illuminant. | Burner or Lamp. | of Illuminant. | ation. | | | | | Pence. | | | | | | |____________|____________________|____________________|____________| | | | | | | |Self-luminous; 0.5 | Calcium carbide | | | | cubic foot per hour| (yielding 5 | 1.00 | | |Self-luminous; 0.7 | cubic feet of | | | Acetylene | cubic foot per hour| acetylene per | 1.10 | | |Self-luminous; 1.0 | lb.) at 15s. | | | | cubic foot per hour| per cwt., inclu- | 1.16 | | |Incandescent; 0.5 | ding delivery | | | | cubic foot per hour| charges. | 0.74 | |____________|____________________|____________________|____________| | | | | | | Petroleum | Large lamp . . . . | Oil, 9d. per gal- | 0.84 | | (paraffin | | lon, including | | | oil) | Small lamp . . . . | delivery charges. | 0.92 | |____________|____________________|____________________|____________| | | | | | | |Flat flame (bad) 5 | | | | | cubic feet per hour| Public supply | 3.00 | | |Flat flame (good) 6 | from small | | | Coal Gas | cubic feet per hour| country works, | 2.16 | | |Incandescent (No. 1 | at 5s. per 1000 | | | | Kern or Bijou In- | cubic feet. | 0.38 | | | verted); 1-1/2 | | | | | cubic feet per hour| | | |____________|____________________|____________________|____________| | | | | | | Candles |"Wax" (so-called) . | 5d. per lb. | 2.60 | |____________|____________________|____________________|____________| | | | | | | | Small glow . . . . | Public supply | 2.16 | | | Large glow . . . . | from small | 2.64 | | Electricity| | town works | | | | Tantalum . . . . . | at 6d. per | 1.45 | | | Osram . . . . . . | B.O.T. unit. | 0.98 | |____________|____________________|____________________|____________| _______________________________________________________________________ | | | | | | | | | |Inci- | Exhaus- |Vitiation | Heat | | | | den- | tion of | of Air. |Produced.| | | Description of | tal |Air.Cubic|Cubic Feet|Number of| |Illuminant. | Burner or Lamp. |Expen-|Feet Dep-| of Car- |Units of | | | | ces. |rived of |bonic Acid| Heat. | | | | | Oxygen. | Formed. |Calories.| |____________|____________________|______|_________|__________|_________| | | | | | | | | |Self-luminous; 0.5 | | | | | | | cubic foot per hour| [1] | 29.8 | 5.0 | 900 | | |Self-luminous; 0.7 | | | | | | Acetylene | cubic foot per hour| | 33.3 | 5.6 | 1010 | | |Self-luminous; 1.0 | | | | | | | cubic foot per hour| | 35.7 | 6.0 | 1000 | | |Incandescent; 0.5 | | | | | | | cubic foot per hour| [2] | 17.9 | 3.0 | 545 | |____________|____________________|______|_________|__________|_________| | | | | | | | | Petroleum | Large lamp . . . . | | 140.0 | 19.6 | 3630 | | (paraffin | | [3] | | | | | oil) | Small lamp . . . . | | 154.0 | 21.6 | 4000 | |____________|____________________|______|_________|__________|_________| | | | | | | | | |Flat flame (bad) 5 | | | | | | | cubic feet per hour| Nil | 270.0 | 27.0 | 7750 | | |Flat flame (good) 6 | | | | | | Coal Gas | cubic feet per hour| Nil | 195.0 | 19.5 | 5580 | | |Incandescent (No. 1 | | | | | | | Kern or Bijou In- | [4] | 27.0 | 2.7 | 775 | | | verted); 1-1/2 | | | | | | | cubic feet per hour| | | | | |____________|____________________|______|_________|__________|_________| | | | | | | | | Candles |"Wax" (so-called) . | Nil | 100.5 | 13.7 | 2700 | |____________|____________________|______|_________|__________|_________| | | | | | | | | | Small glow . . . . |2s.6d.| Nil | Nil | 285 | | | Large glow . . . . |2s.6d.| " | " | 360 | | Electricity| | [5] | | | | | | Tantalum . . . . . |7s.6d.| " | " | 172 | | | Osram . . . . . . | 6s. | " | " | 96 | |____________|____________________|______|_________|__________|_________| [Footnote 1: Interest and depreciation charges on generating and purifying plant = 0.15 penny. Purifying material and burner renewals = 0.05 penny.] [Footnote 2: Mantle renewals as for coal-gas.] [Footnote 3: Renewals of wicks and chimneys = 0.02 penny.] [Footnote 4: Renewals and mantles (and chimneys) at contract rate of 3s. per burner per annum.] [Footnote 5: Renewals of lamps and fuses, at price indicated per lamp per annum.] The conventional method of making pecuniary comparisons between different sources of artificial light consists in simply calculating the cost of developing a certain number of candle-hours of light--_i.e._, a certain amount of standard candle-power for a given number of hours--on the assumption that as many separate sources of light are employed as may be required to bring the combined illuminating power up to the total amount wanted. In view of the facts as to dissemination and diffusion, or the difference between sheer illuminating power and useful illuminating effect, which have just been elaborated, and in view of the different intensities of the different unit sources of light (which range from the single candle to a powerful large incandescent gas-burner or a metallic filament electric lamp), such a method of calculation is wholly illusory. The plan adopted in the following table may also appear unnecessarily complicated; but it is not so to the reader if he remembers that the apparently various amount of illumination is corrected by the different numbers of illuminating units until the amount of simple candle-power developed, whatever illuminant be employed, suffices to light a room having an area of about 300 square feet (_i.e._, a room, 17-1/2 feet square, or one 20 feet long by 15 feet wide), so that ordinary print may be read comfortably in any part of the room, and the titles of books, engravings, &c., in any position on the walls up to a height of 8 feet from the ground may be distinguished with ease. The difference in cost, &c., of a greater or less degree of illumination, or of lighting a larger or smaller room by acetylene or any other of the illuminants named, will be almost directly proportional to the cost given for the stated conditions. Nevertheless, it should be recollected that when the conventional system is retained--useful illuminating effect being sacrificed to absolute illuminating power--acetylene is made to appear cheaper in comparison with all weaker unit sources of light, and dearer in comparison with all stronger unit sources of light than the accompanying table indicates it to be. In using the comparative figures given in the table, it should be borne in mind that they refer to more general and more brilliant illumination of a room than is commonly in vogue where the lighting is by means of electric light, candles, or oil- lamps. The standard of illumination adopted for the table is one which is only gaining general recognition where incandescent gas or acetylene lighting is available, though in exceptional cases it has doubtless been attained by means of oil-lamps or flat-flame gas-burners, but very rarely if ever by means of carbon-filament electric glow-lamps, or candles. It assumes that the occupants of a room do not wish to be troubled to bring work or book "to the light," but wish to be able to work or read wheresoever in the room they will, without consideration of the whereabouts of the light or lights. It should, perhaps, be added that so high a price as 5s. per 1000 cubic feet for coal-gas rarely prevails in Great Britain, except in small outlying towns, whereas the price of 6d. per Board of Trade unit for electricity is not uncommonly exceeded in the few similar country places in which there is a public electricity supply. CHAPTER II THE PHYSICS AND CHEMISTRY OF THE REACTION BETWEEN CARBIDE AND WATER THE NATURE OF CALCIUM CARBIDE.--The raw material from which, by interaction with water, acetylene is obtained, is a solid body called calcium carbide or carbide of calcium. Inasmuch as this substance can at present only be made on a commercial scale in the electric furnace--and so far as may be foreseen will never be made on a large scale except by means of electricity--inasmuch as an electric furnace can only be worked remuneratively in large factories supplied with cheap coal or water power; and inasmuch as there is no possibility of the ordinary consumer of acetylene ever being able to prepare his own carbide, all descriptions of this latter substance, all methods of winning it, and all its properties except those which concern the acetylene-generator builder or the gas consumer have been omitted from the present book. Hitherto calcium carbide has found but few applications beyond that of evolving acetylene on treatment with water or some aqueous liquid, hygroscopic solid, or salt containing water of crystallisation; but it has possibilities of further employment, should its price become suitable, and a few words will be devoted to this branch of the subject in Chapter XII. Setting these minor uses aside, calcium carbide has no intrinsic value except as a producer of acetylene, and therefore all its characteristics which interest the consumer of acetylene are developed incidentally throughout this volume as the necessity for dealing with them arises. It is desirable, however, now to discuss one point connected with solid carbide about which some misconception prevails. Calcium carbide is a body which evolves an inflammable, or on occasion an explosive, gas when treated with water; and therefore its presence in a building has been said to cause a sensible increase in the fire risk because attempts to extinguish a fire in the ordinary manner with water may cause evolution of acetylene which should determine a further production of flame and heat. In the absence of water, calcium carbide is absolutely inert as regards fire; and on several occasions drums of it have been recovered uninjured from the basement of a house which has been totally destroyed by fire. With the exception of small 1-lb. tins of carbide, used only by cyclists, &c., the material is always put into drums of stout sheet-iron with riveted or folded seams. Provided the original lid has not been removed, the drums are air- and water-tight, so that the fireman's hose may be directed upon them with impunity. When a drum has once been opened, and not all of its contents have been put into the generator, ordinary caution--not merely as regards fire, but as regards the deterioration of carbide when exposed to the atmosphere--suggests either that the lid must be made air-tight again (not by soldering it), [Footnote: Carbide drums are not uncommonly fitted with self-sealing or lever-top lids, which are readily replaced hermetically tight after opening and partial removal of the contents of the drum.] or preferably that the rest of the carbide shall be transferred to some convenient receptacle which can be perfectly closed. [Footnote: It would be a refinement of caution, though hardly necessary in practice, to fit such a receptacle with a safety-valve. If then the vessel were subjected to sudden or severe heating, the expansion of the air and acetylene in it could not possibly exert a disruptive effect upon the walls of the receptacle, which, in the absence of the safety-valve, is imaginable.] Now, assuming this done, the drums are not dependent upon soft solder to keep them sound, and so they cannot open with heat. Fire and water, accordingly, cannot affect them, and only two risks remain: if stored in the basement of a tall building, falling girders, beams or brickwork may burst them; or if stored on an upper floor, they may fall into the basement and be burst with the shock--in either event water then having free access to the contents. But drums of carbide would never be stored in such positions: a single one would be kept in the generator-house; several would be stored in a separate room therein, or in some similar isolated shed. The generator-house or shed would be of one story only; the drums could neither fall nor have heavy weights fall on them during a fire; and therefore there is no reason why, if a fire should occur, the firemen should not be permitted to use their hose in the ordinary fashion. Very similar remarks apply to an active acetylene generator. Well built, such plant will stand much heat and fire without failure; if it is non-automatic, and of combustible materials contains nothing but gas in the holder, the worst that could happen in times of fire would be the unsealing of the bell or its fracture, and this would be followed, not at all by any explosion, but by a fairly quiet burning of the escaping gas, which would be over in a very short time, and would not add to the severity of the conflagration unless the generator-house were so close to the residence that the large flame of burning gas could ignite part of the main building. Even if the heat were so great near the holder that the gas dissociated, it is scarcely conceivable that a dangerous explosion should arise. But it is well to remember, that if the generator-house is properly isolated from the residence, if it is constructed of non-inflammable materials, if the attendant obeys instructions and refrains from taking a naked light into the neighbourhood of the plant, and if the plant itself is properly designed and constructed, a fire at or near an acetylene generator is extremely unlikely to occur. At the same time, before the erection of plant to supply any insured premises is undertaken, the policy or the company should be consulted to ascertain whether the adoption of acetylene lighting is possibly still regarded by the insurers as adding an extra risk or even as vitiating the whole insurance. REGULATIONS FOR THE STORAGE OF CARBIDE: BRITISH.--There are also certain regulations imposed by many local authorities respecting the storage of carbide, and usually a licence for storage has to be obtained if more than 5 lb. is kept at a time. The idea of the rule is perfectly justifiable, and it is generally enforced in a sensible spirit. As the rules may vary in different localities, the intending consumer of acetylene must make the necessary inquiries, for failure to comply with the regulations may obviously be followed by unpleasantness. Having regard to the fact that, in virtue of an Order in Council dated July 7, 1897, carbide may be stored without a licence only in separate substantial hermetically closed metal vessels containing not more than 1 lb. apiece and in quantities not exceeding 5 lb. in the aggregate, and having regard also to the fact that regulations are issued by local authorities, the Fire Offices' Committee of the United Kingdom has not up to the present deemed it necessary to issue special rules with reference to the storage of carbide of calcium. The following is a copy of the rules issued by the National Board of Fire Underwriters of the UNITED STATES OF AMERICA for the storage of calcium carbide on insured premises: RULES FOR THE STORAGE OF CALCIUM CARBIDE. (_a_) Calcium carbide in quantities not to exceed six hundred (600) pounds may be stored, when contained in approved metal packages not to exceed one hundred (100) pounds each, inside insured property, provided that the place of storage be dry, waterproof and well ventilated, and also provided that all but one of the packages in any one building shall be sealed and the seals shall not be broken so long as there is carbide in excess of one (1) pound in any other unsealed package in the building. (_b_) Calcium carbide in quantities in excess of six hundred (600) pounds must be stored above ground in detached buildings, used exclusively for the storage of calcium carbide, in approved metal packages, and such buildings shall be constructed to be dry, waterproof and well ventilated. (_c_) Packages to be approved must be made of metal of sufficient strength to insure handling the package without rupture, and be provided with a screwed top or its equivalent. They must be constructed so as to be water- and air-tight without the use of solder, and conspicuously marked "CALCIUM CARBIDE--DANGEROUS IF NOT KEPT DRY." The following is a summary of the AUSTRIAN GOVERNMENT rules relating to the storage and handling of carbide: (1) It must be sold and stored only in closed water-tight vessels, which, if the contents exceed 10 kilos., must be marked in plain letters "CALCIUM CARBIDE--TO BE KEPT CLOSED AND DRY." They must not be of copper and if soldered must be opened by mechanical means and not by unsoldering. They must be stored out of the reach of water. (2) Quantities not exceeding 300 kilos. may be stored in occupied houses, provided the single drums do not exceed 100 kilos. nominal capacity. The storage-place must be dry and not underground. (3) The limits specified in Rule 2 apply also to generator-rooms, with the proviso also that in general the amount stored shall not exceed five days' consumption. (4) Quantities ranging from 300 to 1000 kilos. must be stored in special well-ventilated uninhabited non-basement rooms in which lights and smoking are not allowed. (5) Quantities exceeding 1000 kilos. must be stored in isolated fireproof magazines with light water-tight roofs. The floors must be at least 8 inches above ground-level. (6) Carbide in water-tight drums may be stored in the open in a fenced enclosure at least 30 feet from buildings, adjoining property, or inflammable materials. The drums must be protected from wet by a light roof. (7) The breaking of carbide must be done by men provided with respirators and goggles, and care taken to avoid the formation of dust. (8) Local or other authorities will issue from time to time special regulations in regard to carbide trade premises. The ITALIAN GOVERNMENT rules relating to the storage and transport of carbide follow in the main those of the Austrian Government, but for quantities between 300 and 2000 kilos sanction is required from the local authorities, and for larger quantities from superior authorities. The storage of quantities ranging from 300 to 2000 kilos is forbidden in dwelling-houses and above the latter quantity the storage-place must be isolated and specially selected. No special permit is required for the storage of quantities not exceeding 300 kilos. Workmen exposed to carbide dust arising from the breaking of carbide or otherwise must have their eyes and respiratory organs suitably protected. THE PURCHASE OF CARBIDE.--Since calcium carbide is only useful as a means of preparing acetylene, it should be bought under a guarantee (1) that it contains less impurities than suffice to render the crude gas dangerous in respect of spontaneous inflammability, or objectionable in a manner to be explained later on, when consumed; and (2) that it is capable of evolving a fixed minimum quantity of acetylene when decomposed by water. Such determination, however, cannot be carried out by the ordinary consumer for himself. A generator which is perfectly satisfactory in general behaviour, and which evolves a sufficient proportion of the possible total make of gas to be economical, does not of necessity decompose the carbide quantitatively; nor is it constructed in a fashion to render an exact measurement of the gas liberated at standard temperature and pressure easy to obtain. For obvious reasons the careful consumer of acetylene will keep a record of the carbide decomposed and of the acetylene generated--the latter perhaps only in terms of burner- hours, or the like; but in the event of serious dispute as to the gas- making capacity of his raw material, he must have a proper analysis made by a qualified chemist. Calcium carbide is crushed by the makers into several different sizes, in each of which all the lumps exceed a certain size and are smaller than another size. It is necessary to find out by experiment, or from the maker, what particular size suits the generator best, for different types of apparatus require different sizes of carbide. Carbide cannot well be crushed by the consumer of acetylene. It is a difficult operation, and fraught with the production of dust which is harmful to the eyes and throat, and if done in open vessels the carbide deteriorates in gas- making power by its exposure to the moisture of the atmosphere. True dust in carbide is objectionable, and practically useless for the generation of acetylene in any form of apparatus, but carbide exceeding 1 inch in mesh is usually sold to satisfy the suggestions of the British Acetylene Association, which prescribes 5 per cent, of dust as the maximum. Some grades of carbide are softer than others, and therefore tend to yield more dust if exposed to a long journey with frequent unloadings. There are certain varieties of ordinary carbide known as "treated carbide," the value of which is more particularly discussed in Chapter III. The treatment is of two kinds, or of a combination of both. In one process the lumps are coated with a strong solution of glucose, with the object of assisting in the removal of spent lime from their surface when the carbide is immersed in water. Lime is comparatively much more soluble in solutions of sugar (to which class of substances glucose belongs) than in plain water; so that carbide treated with glucose is not so likely to be covered with a closely adherent skin of spent lime when decomposed by the addition of water to it. In the other process, the carbide is coated with or immersed in some oil or grease to protect it from premature decomposition. The latter idea, at least, fulfils its promises, and does keep the carbide to a large extent unchanged if the lumps are exposed to damp air, while solving certain troubles otherwise met with in some generators (cf. Chapter III.); but both operations involve additional expense, and since ordinary carbide can be used satisfactorily in a good fixed generator, and can be preserved without serious deterioration by the exercise of reasonable care, treated carbide is only to be recommended for employment in holderless generators, of which table-lamps are the most conspicuous forms. A third variant of plain carbide is occasionally heard of, which is termed "scented" carbide. It is difficult to regard this material seriously. In all probability calcium carbide is odourless, but as it begins to evolve traces of gas immediately atmospheric moisture reaches it, a lump of carbide has always the unpleasant smell of crude acetylene. As the material is not to be stored in occupied rooms, and as all odour is lost to the senses directly the carbide is put into the generator, scented carbide may be said to be devoid of all utility. THE REACTION BETWEEN CARBIDE AND WATER.--The reaction which occurs when calcium carbide and water are brought into contact belongs to the class that chemists usually term double decompositions. Calcium carbide is a chemical compound of the metal calcium with carbon, containing one chemical "part," or atomic weight, of the former united to two chemical parts, or atomic weights, of the latter; its composition expressed in symbols being CaC_2. Similarly, water is a compound of two chemical parts of hydrogen with one of oxygen, its formula being H_2O. When those two substances are mixed together the hydrogen of the water leaves its original partner, oxygen, and the carbon of the calcium carbide leaves the calcium, uniting together to form that particular compound of hydrogen and carbon, or hydrocarbon, which is known as acetylene, whose formula is C_2H_2; while the residual calcium and oxygen join together to produce calcium oxide or lime, CaO. Put into the usual form of an equation, the reaction proceeds thus-- (1) CaC_2 + H_2O = C_2H_2 + CaO. This equation not only means that calcium carbide and water combine to yield acetylene and lime, it also means that one chemical part of carbide reacts with one chemical part of water to produce one chemical part of acetylene and one of lime. But these four chemical parts, or molecules, which are all equal chemically, are not equal in weight; although, according to a common law of chemistry, they each bear a fixed proportion to one another. Reference to the table of "Atomic Weights" contained in any text-book of chemistry will show that while the symbol Ca is used, for convenience, as a contraction or sign for the element calcium simply, it bears a more important quantitative significance, for to it will be found assigned the number 40. Against carbon will be seen the number 12; against oxygen, 16; and against hydrogen, 1. These numbers indicate that if the smallest weight of hydrogen ever found in a chemical compound is called 1 as a unit of comparison, the smallest weights of calcium, carbon, and oxygen, similarly taking part in chemical reactions are 40, 12, and 16 respectively. Thus the symbol CaC_2, comes to convoy three separate ideas: (_a_) that the substance referred to is a compound of calcium and carbon only, and that it is therefore a carbide of calcium; (_b_) that it is composed of one chemical part or atom of calcium and two atoms of carbon; and (_c_) that it contains 40 parts by weight of calcium combined with twice twelve, or 24, parts of carbon. It follows from (_c_) that the weight of one chemical part, now termed a molecule as the substance is a compound, of calcium carbide is (40 + 2 x 12) = 64. By identical methods of calculation it will be found that the weight of one molecule of water is 18; that of acetylene, 26; and that of lime, 56. The general equation (1) given above, therefore, states in chemical shorthand that 64 parts by weight of calcium carbide react with 18 parts of water to give 26 parts by weight of acetylene and 56 parts of lime; and it is very important to observe that just as there are the same number of chemical parts, viz., 2, on each side, so there are the same number of parts by weight, for 64 + 18 = 56 + 26 = 82. Put into other words equation (1) shows that if 64 grammes, lb., or cwts. of calcium carbide are treated with 18 grammes, lb., or cwts. of water, the whole mass will be converted into acetylene and lime, and the residue will not contain any unaltered calcium carbide or any water; whence it may be inferred, as is the fact, that if the weights of carbide and water originally taken do not stand to one another in the ratio 64 : 18, both substances cannot be entirely decomposed, but a certain quantity of the one which was in excess will be left unattacked, and that quantity will be in exact accordance with the amount of the said excess--indifferently whether the superabundant substance be carbide or water. Hitherto, for the sake of simplicity, the by-product in the preparation of acetylene has been described as calcium oxide or quicklime. It is, however, one of the leading characteristics of this body to be hygroscopic, or greedy of moisture; so that if it is brought into the presence of water, either in the form of liquid or as vapour, it immediately combines therewith to yield calcium hydroxide, or slaked lime, whose chemical formula is Ca(OH)_2. Accordingly, in actual practice, when calcium carbide is mixed with an excess of water, a secondary reaction takes place over and above that indicated by equation (1), the quicklime produced combining with one chemical part or molecule of water, thus-- CaO + H_2O = Ca(OH)_2. As these two actions occur simultaneously, it is more usual, and more in agreement with the phenomena of an acetylene generator, to represent the decomposition of calcium carbide by the combined equation-- (2) CaC_2 + 2H_2O = C_2H_2 + Ca(OH)_2. By the aid of calculations analogous to those employed in the preceding paragraph, it will be noticed that equation (2) states that 1 molecule of calcium carbide, or 64 parts by weight, combines with 2 molecules of water, or 36 parts by weight, to yield 1 molecule, or 26 parts by weight of acetylene, and 1 molecule, or 74 parts by weight of calcium hydroxide (slaked lime). Here again, if more than 36 parts of water are taken for every 64 parts of calcium carbide, the excess of water over those 36 parts is left undecomposed; and in the same fashion, if less than 36 parts of water are taken for every 64 parts of calcium carbide, some of the latter must remain unattacked, whilst, obviously, the amount of acetylene liberated cannot exceed that which corresponds with the quantity of substance suffering complete decomposition. If, for example, the quantity of water present in a generator is more than chemically sufficient to attack all the carbide added, however largo or small that excess may be, no more, and, theoretically speaking, no less, acetylene can ever be evolved than 26 parts by weight of gas for every 64 parts by weight of calcium carbide consumed. It is, however, not correct to invert the proposition, and to say that if the carbide is in excess of the water added, no more, and, theoretically speaking, no less, acetylene can ever be evolved than 26 parts by weight of gas for every 36 parts of water consumed, as might be gathered from equation (2); because equation (1) shows that 26 parts of acetylene may, on occasion, be produced by the decomposition of 18 parts by weight of water. From the purely chemical point of view this apparent anomaly is explained by the circumstance that of the 36 parts of water present on the left-hand aide of equation (2), only one-half, _i.e._, 18 parts by weight, are actually decomposed into hydrogen and oxygen, the other 18 parts remaining unattacked, and merely attaching themselves as "water of hydration" to the 56 parts of calcium oxide in equation (1) so as to produce the 74 parts of calcium hydroxide appearing on the right-hand side of equation (2). The matter is perhaps rendered more intelligible by employing the old name for calcium hydroxide or slaked lime, viz., hydrated oxide of calcium, and by writing its formula in the corresponding form, when equation (2) becomes CaC_2 + 2H_2O = C_2H_2 + CaO.H_2O. It is, therefore, absolutely correct to state that if the amount of calcium carbide present in an acetylene generator is more than chemically sufficient to decompose all the water introduced, no more, and theoretically speaking no less, acetylene can ever be liberated than 26 parts by weight of gas for every 18 parts by weight of water attacked. This, it must be distinctly understood, is the condition of affairs obtaining in the ideal acetylene generator only; since, for reasons which will be immediately explained, when the output of gas is measured in terms of the water decomposed, in no commercial apparatus, and indeed in no generator which can be imagined fit for actual employment, does that output of gas ever approach the quantitative amount; but the volume of water used, if not actually disappearing, is always vastly in excess of the requirements of equation (2). On the contrary, when the make of gas is measured in terms of the calcium carbide consumed, the said make may, and frequently does, reach 80, 90, or even 99 per cent. of what is theoretically possible. Inasmuch as calcium carbide is the one costly ingredient in the manufacture of acetylene, so long as it is not wasted-- so long, that is to say, as nearly the theoretical yield of gas is obtained from it--an acetylene generator is satisfactory or efficient in this particular; and except for the matter of solubility discussed in the following chapter, the quantity of water consumed is of no importance whatever. HEAT EVOLVED IN THE REACTION.--The chemical reaction between calcium carbide and water is accompanied by a large evolution of heat, which, unless due precautions are taken to prevent it, raises the temperature of the substances employed, and of the apparatus containing them, to a serious and often inconvenient extent. This phenomenon is the most important of all in connexion with acetylene manufacture; for upon a proper recognition of it, and upon the character of the precautions taken to avoid its numerous evil effects, depend the actual value and capacity for smooth working of any acetylene generator. Just as, by an immutable law of chemistry, a given weight of calcium carbide yields a given weight of acetylene, and by no amount of ingenuity can be made to produce either more or less; so, by an equally immutable law of physics, the decomposition of a given weight of calcium carbide by water, or the decomposition of a given weight of water by calcium carbide, yields a perfectly definite quantity of heat--a quantity of heat which cannot be reduced or increased by any artifice whatever. The result of a production of heat is usually to raise the temperature of the material in which it is produced; but this is not always the case, and indeed there is no necessary connexion or ratio between the quantity of heat liberated in any form of chemical reaction--of which ordinary combustion is the commonest type--and the temperature attained by the substances concerned. This matter has so weighty a bearing upon acetylene generation, and appears to be so frequently misunderstood, that a couple of illustrations may with advantage be studied. If a vessel full of cold water, and containing also a thermometer, is placed over a lighted gas-burner, at first the temperature of the liquid rises steadily, and there is clearly a ratio between the size of the flame and the speed at which the mercury mounts up the scale. Finally, however, the thermometer indicates a certain point, viz., 100° C, and the water begins to boil; yet although the burner is untouched, and consequently, although heat must be passing into the vessel at the same rate as before, the mercury refuses to move as long as any liquid water is left. By the use of a gas meter it might be shown that the same volume of gas is always consumed (_a_) in raising the temperature of a given quantity of cold water to the boiling- point, and another equally constant volume of gas is always consumed (_b_) in causing the boiling water to disappear as steam. Hence, as coal-gas is assumed for the present purpose to possess invariably the same heating power, it appears that the same quantity of heat is always needed to convert a given amount of cold water at a certain temperature into steam; but inasmuch as reference to the meter would show that about 5 times the volume of gas is consumed in changing the boiling water into steam as is used in heating the cold water to the boiling-point, it will be evident that the temperature of the mass is raised as high by the heat evolved during the combustion of one part of gas as it is by that liberated on the combustion of 6 times that amount. A further example of the difference between quantity of heat and sensible temperature may be seen in the combustion of coal, for (say) one hundredweight of that fuel might be consumed in a very few minutes in a furnace fitted with a powerful blast of air, the operation might be spread over a considerable number of hours in a domestic grate, or the coal might be allowed to oxidise by exposure to warm air for a year or more. In the last case the temperature might not attain that of boiling water, in the second it would be about that of dull redness, and in the first it would be that of dazzling whiteness; but in all three cases the total quantity of heat produced by the time the coal was entirely consumed would be absolutely identical. The former experiment with water and a gas-burner, too, might easily be modified to throw light upon another problem in acetylene generation, for it would be found that if almost any other liquid than water were taken, less gas (_i.e._, a smaller quantity of heat) would be required to raise a given weight of it from a certain low to a certain high temperature than in the case of water itself; while if it were possible similarly to treat the same weight of iron (of which acetylene generators are constructed), or of calcium carbide, the quantity of heat used to raise it through a given number of thermometric degrees would hardly exceed one-tenth or one- quarter of that needed by water itself. In technical language this difference is due to the different specific heats of the substances mentioned; the specific heat of a body being the relative quantity of heat consumed in raising a certain weight of it a certain number of degrees when the quantity of heat needed to produce the same effect on the same weight of water is called unity. Thus, the specific heat of water being termed 1.0, that of iron or steel is 0.1138, and that of calcium carbide 0.247, [Footnote: This is Carlson's figure. Morel has taken the value 0.103 in certain calculations.] both measured at temperatures where water is a liquid. Putting the foregoing facts in another shape, for a given rise in temperature that substance will absorb the most heat which has the highest specific heat, and therefore, in this respect, 1 part by weight of water will do the work of roughly 9 parts by weight of iron, and of about 4 parts by weight of calcium carbide. From the practical aspect what has been said amounts to this: During the operation of an acetylene generator a large amount of heat is produced, the quantity of which is beyond human control. It is desirable, for various reasons, that the temperature shall be kept as low as possible. There are three substances present to which the heat may be compelled to transfer itself until it has opportunity to pass into the surrounding atmosphere: the material of which the apparatus is constructed, the gas which is in process of evolution, and whichever of the two bodies-- calcium carbide or water--is in excess in the generator. Of these, the specific heat at constant pressure of acetylene has unfortunately not yet been determined, but its relative capacity for absorbing heat is undoubtedly small; moreover the gas could not be permitted to become sufficiently hot to carry off the heat without grave disadvantages. The specific heat of calcium carbide is also comparatively small, and there are similar disadvantages in allowing it to become hot; moreover it is deficient in heat-conducting power, so that heat communicated to one portion of the mass does not extend rapidly throughout, but remains concentrated in one spot, causing the temperature to rise objectionably. Steel has a sufficient amount of heat-conducting power to prevent undue concentration in one place; but, as has been stated, its specific heat is only one-ninth that of water. Water is clearly, therefore, the proper substance to employ for the dissipation of the heat generated, although it is strictly speaking almost devoid of heat-conducting power; for not only is the specific heat of water much greater than that of any other material present, but it possesses in a high degree the faculty of absorbing heat throughout its mass, by virtue of the action known as convection, provided that heat is communicated to it at or near the bottom, and not too near its upper surface. Moreover, water is a much more valuable substance for dissipating heat than appears from the foregoing explanation; for reference to the experiment with the gas- burner will show that six and a quarter times as much heat can be absorbed by a given weight of water if it is permitted to change into steam, as if it is merely raised to the boiling-point; and since by no urging of the gas-burner can the temperature be raised above 100° C. as long as any liquid water remains unevaporated, if an excess of water is employed in an acetylene generator, the temperature inside can never-- except quite locally--exceed 100° C., however fast the carbide be decomposed. An indefinitely large consumption of water by evaporation in a generator matters nothing, for the liquid may be considered of no pecuniary value, and it can all be recovered by condensation in a subsequent portion of the plant. It has been said that the quantity of heat liberated when a certain amount of carbide suffers decomposition is fixed; it remains now to consider what that quantity is. Quantities of heat are always measured in terms of the amount needed to raise a certain weight of water a certain number of degrees on the thermometric scale. There are several units in use, but the one which will be employed throughout this book is the "Large Calorie"; a large calorie being the amount of heat absorbed in raising 1 kilogramme of water 1° C. Referring for a moment to what has been said about specific heats, it will be apparent that if 1 large calorie is sufficient to heat 1 kilo, of water through 1° C. the same quantity will heat 1 kilo. of steel, whose specific heat is roughly 0.11, through (10/011) = 9° C., or, which comes to the same thing, will heat 9 kilos, of steel through 1° C.; and similarly, 1 large calorie will raise 4 kilos. of calcium carbide 1° C. in temperature, or 1 kilo. 4° C. The fact that a definite quantity of heat is manifested when a known weight of calcium carbide is decomposed by water is only typical; for in every chemical process some disturbance of heat, though not necessarily of sensible (or thermometric) character, occurs, heat being either absorbed or set free. Moreover, if when given weights of two or more substances unite to form a given weight of another substance, a certain quantity of heat is set free, precisely the same amount of heat is absorbed, or disappears, when the latter substance is decomposed to form the same quantities of the original substances; and, _per contra_, if the combination is attended by a disappearance of heat, exactly the same amount is liberated when the compound is broken up into its first constituents. Compounds are therefore of two kinds: those which absorb heat during their preparation, and consequently liberate heat when they are decomposed--such being termed endothermic; and those which evolve heat during their preparation, and consequently absorb heat when they are decomposed--such being called exothermic. If a substance absorbs heat during its formation, it cannot be produced unless that heat is supplied to it; and since heat, being a form of motion, is equally a form of energy, energy must be supplied, or work must be done, before that substance can be obtained. Conversely, if a substance evolves heat during its formation, its component parts evolve energy when the said substance is being produced; and therefore the mere act of combination is accompanied by a facility for doing work, which work may be applied in assisting some other reaction that requires heat, or may be usefully employed in any other fashion, or wasted if necessary. Seeing that there is a tendency in nature for the steady dissipation of energy, it follows that an exothermic substance is stable, for it tends to remain as it is unless heat is supplied to it, or work is done upon it; whereas, according to its degree of endothermicity, an endothermic substance is more or less unstable, for it is always ready to emit heat, or to do work, as soon as an opportunity is given to it to decompose. The theoretical and practical results of this circumstance will be elaborated in Chapter VI., when the endothermic nature of acetylene is more fully discussed. A very simple experiment will show that a notable quantity of heat is set free when calcium carbide is brought into contact with water, and by arranging the details of the apparatus in a suitable manner, the quantity of heat manifested may be measured with considerable accuracy. A lengthy description of the method of performing this operation, however, scarcely comes within the province of the present book, and it must be sufficient to say that the heat is estimated by decomposing a known weight of carbide by means of water in a small vessel surrounded on all sides by a carefully jacketed receptacle full of water and provided with a sensitive thermometer. The quantity of water contained in the outer vessel being known, and its temperature having been noted before the reaction commences, an observation of the thermometer after the decomposition is finished, and when the mercury has reached its highest point, gives data which show that the reaction between water and a known weight of calcium carbide produces heat sufficient in amount to raise a known weight of water through a known thermometric distance; and from these figures the corresponding number of large calories may easily be calculated. A determination of this quantity of heat has been made experimentally by several investigators, including Lewes, who has found that the heat evolved on decomposing 1 gramme of ordinary commercial carbide with water is 0.406 large calorie. [Footnote: Lewes returns his result as 406 calories, because he employs the "small calorie." The small calorie is the quantity of heat needed to raise 1 gramme of water 1° C.; but as there are 1000 grammes in 1 kilogramme, the large calorie is equal to 1000 small calories. In many respects the former unit is to be preferred.] As the material operated upon contained only 91.3 per cent. of true calcium carbide, he estimates the heat corresponding with the decomposition of 1 gramme of pure carbide to be 0.4446 large calorie. As, however, it is better, and more in accordance with modern practice, to quote such data in terms of the atomic or molecular weight of the substance concerned, and as the molecular weight of calcium carbide is 64, it is preferable to multiply these figures by 64, stating that, according to Lewes' researches, the heat of decomposition of "1 gramme- molecule" (_i.e._, 64 grammes) of a calcium carbide having a purity of 91.3 per cent. is just under 26 calories, or that of 1 gramme-molecule of pure carbide 28.454 calories. It is customary now to omit the phrase "one gramme-molecule" in giving similar figures, physicists saying simply that the heat of decomposition of calcium carbide by water when calcium hydroxide is the by-product, is 28.454 large calories. Assuming all the necessary data known, as happens to be the case in the present instance, it is also possible to calculate theoretically the heat which should be evolved on decomposing calcium carbide by means of water. Equation (2), given on page 24, shows that of the substances taking part in the reaction 1 molecular weight of calcium carbide is decomposed, and 1 molecular weight of acetylene is formed. Of the two molecules of water, only one is decomposed, the other passing to the calcium hydroxide unchanged; and the 1 molecule of calcium hydroxide is formed by the combination of 1 atom of free calcium, 1 atom of free oxygen, and 1 molecule of water already existing as such. Calcium hydroxide and water are both exothermic substances, absorbing heat when they are decomposed, liberating it when they are formed. Acetylene is endothermic, liberating heat when it is decomposed, absorbing it when it is produced. Unfortunately there is still some doubt about the heat of formation of calcium carbide, De Forcrand returning it as -0.65 calorie, and Gin as +3.9 calories. De Forcrand's figure means, as before explained, that 64 grammes of carbide should absorb 0.65 large calorie when they are produced by the combination of 40 grammes of calcium with 24 grammes of carbon; the minus sign calling attention to the belief that calcium carbide is endothermic, heat being liberated when it suffers decomposition. On the contrary, Gin's figure expresses the idea that calcium carbide is exothermic, liberating 3.9 calories when it is produced, and absorbing them when it is decomposed. In the absence of corroborative evidence one way or the other, Gin's determination will be accepted for the ensuing calculation. In equation (2), therefore, calcium carbide is decomposed and absorbs heat; water is decomposed and absorbs heat; acetylene is produced and absorbs heat; and calcium hydroxide is produced liberating heat. On consulting the tables of thermo-chemical data given in the various text-books on physical chemistry, all the other constants needed for the present purpose will be found; and it will appear that the heat of formation of water is +69 calories, that of acetylene -58.1 calories, and that of calcium hydroxide, when 1 atom of calcium, 1 atom of oxygen, and 1 molecule of water unite together, is +160.1 calories. [Footnote: When 1 atom of calcium, 2 atoms of oxygen, and 2 atoms of hydrogen unite to form solid calcium hydroxide, the heat of formation of the latter is 229.1 (cf. _infra_). This value is simply 160.1 + 69.0 = 229.1; 69.0 being the heat of formation of water.] Collecting the results into the form of a balance-sheet, the effect of decomposing calcium carbide with water is this: _Heat liberated._ | _Heat absorbed._ | Formation of Ca(OH)_2 16O.1 | Formation of acetylene 58.1 | Decomposition of water 69.0 | Decomposition of carbide 3.9 | Balance 29.1 _____ | _____ | Total 160.1 | Total 160.1 Therefore when 64 grammes of calcium carbide are decomposed by water, or when 18 grammes of water are decomposed by calcium carbide (the by- product in each case being calcium hydroxide or slaked lime, for the formation of which a further 18 grammes of water must be present in the second instance), 29.1 large calories are set free. It is not possible yet to determine thermo-chemical data with extreme accuracy, especially on such a material as calcium carbide, which is hardly to be procured in a state of chemical purity; and so the value 28.454 calories experimentally found by Lewes agrees very satisfactorily, considering all things, with the calculated value 29.1 calories. It is to be noticed, however, that the above calculated value has been deduced on the assumption that the calcium hydroxide is obtained as a dry powder; but as slaked lime is somewhat soluble in water, and as it evolves 3 calories in so dissolving, if sufficient water is present to take up the calcium hydroxide entirely into the liquid form (_i.e._, that of a solution), the amount of heat set free will be greater by those 3 calories, _i.e._, 32.1 large calories altogether. THE PROCESS OF GENERATION.--Taking 28 as the number of large calories developed when 64 grammes of ordinary commercial calcium carbide are decomposed with sufficient water to leave dry solid calcium hydroxide as the by-product in acetylene generation, this quantity of heat is capable of exerting any of the following effects. It is sufficient (1) to raise 1000 grammes of water through 28° C., say from 10° C. (50° F., which is roughly the temperature of ordinary cold water) to 38° C. It is sufficient (2) to raise 64 grammes of water (a weight equal to that of the carbide decomposed) through 438° C., if that were possible. It would raise (3) 311 grammes of water through 90° C., _i.e._, from 10° C. to the boiling-point. If, however, instead of remaining in the liquid state, the water were converted into vapour, the same quantity of heat would suffice (4) to change 44.7 grammes of water at 10° C. into steam at 100° C.; or (5) to change 46.7 grammes of water at 10° C. into vapour at the same temperature. It is an action of the last character which takes place in acetylene generators of the most modern and usual pattern, some of the surplus water being evaporated and carried away as vapour at a comparatively low temperature with the escaping gas; for it must be remembered that although steam, as such, condenses into liquid water immediately the surrounding temperature falls below 100° C., the vapour of water remains uncondensed, even at temperatures below the freezing- point, when that vapour is distributed among some permanent gas--the precise quantity of vapour so remaining being a function of the temperature and barometric height. Thus it appears that if the heat evolved during the decomposition of calcium carbide is not otherwise consumed, it is sufficient in amount to vaporise almost exactly 3 parts by weight of water for every 4 parts of carbide attacked; but if it were expended upon some substance such as acetylene, calcium carbide, or steel, which, unlike water, could not absorb an extra amount by changing its physical state (from solid to liquid, or from liquid to gas), the heat generated during the decomposition of a given weight of carbide would suffice to raise an equal weight of the particular substance under consideration to a temperature vastly exceeding 438° C. The temperature attained, indeed, measured in Centigrade degrees, would be 438 multiplied by the quotient obtained on dividing the specific heat of water by the specific heat of the substance considered: which quotient, obviously, is the "reciprocal" of the specific heat of the said substance. The analogy to the combustion of coal mentioned on a previous page shows that although the quantity of heat evolved during a certain chemical reaction is strictly fixed, the temperature attained is dependent on the time over which the reaction is spread, being higher as the process is more rapid. This is due to the fact that throughout the whole period of reaction heat is escaping from the mass, and passing into the atmosphere at a fairly constant speed; so that, clearly, the more slowly heat is produced, the better opportunity has it to pass away, and the less of it is left to collect in the material under consideration. During the action of an acetylene generator, there is a current of gas constantly travelling away from the carbide, there is vapour of water constantly escaping with the gas, there are the walls of the generator itself constantly exposed to the cooling action of the atmosphere, and there is either a mass of calcium carbide or of water within the generator. It is essential for good working that the temperature of both the acetylene and the carbide shall be prevented from rising to any noteworthy extent; while the amount of heat capable of being dissipated into the air through the walls of the apparatus in a given time is narrowly limited, depending upon the size and shape of the generator, and the temperature of the surrounding air. If, then, a small, suitably designed generator is working quite slowly, the loss of heat through the external walls of the apparatus may easily be rapid enough to prevent the internal temperature from rising objectionably high; but the larger the generator, and the more rapidly it is evolving gas, the less does this become possible. Since of the substances in or about a generator water is the one which has by far the largest capacity for absorbing heat, and since it is the only substance to which any necessary quantity of heat can be safely or conveniently transmitted, it follows that the larger in size an acetylene generator is, or the more rapidly that generator is made to deliver gas, the more desirable is it to use water as the means for dissipating the surplus heat, and the more necessary is it to employ an apparatus in which water is in large chemical excess at the actual place of decomposition. The argument is sometimes advanced that an acetylene generator containing carbide in excess will work satisfactorily without exhibiting an undesirable rise in internal temperature, if the vessel holding the carbide is merely surrounded by a large quantity of cold water. The idea is that the heat evolved in that particular portion of the charge which is suffering decomposition will be communicated with sufficient speed throughout the whole mass of calcium carbide present, whence it will pass through the walls of the containing vessel into the water all round. Provided the generator is quite small, provided the carbide container is so constructed as to possess the maximum of superficial area with the minimum of cubical capacity (a geometrical form to which the sphere, and in one direction the cylinder, are diametrically opposed), and provided the walls of the container do not become coated internally or externally with a coating of lime or water scale so as to diminish in heat- transmitting power, an apparatus designed in the manner indicated is undoubtedly free from grave objection; but immediately any of those provisions is neglected, trouble is likely to ensue, for the heat will not disappear from the place of actual reaction at the necessary speed. Apparent proof that heat is not accumulating unduly in a water-jacketed carbide container even when the generator is evolving gas at a fair speed is easy to obtain; for if, as usually happens, the end of the container through which the carbide is inserted is exposed to the air, the hand may be placed upon it, and it will be found to be only slightly warm to the touch. Such a test, however, is inconclusive, and frequently misleading, because if more than a pound or two of carbide is present as an undivided mass, and if water is allowed to attack one portion of it, that particular portion may attain a high temperature while the rest is comparatively cool: and if the bulk of the carbide is comparatively cool, naturally the walls of the containing vessel themselves remain practically unheated. Three causes work together to prevent this heat being dissipated through the walls of the carbide vessel with sufficient rapidity. In the first place, calcium carbide itself is a very bad conductor of heat. So deficient in heat-conducting power is it that a lump a few inches in diameter may be raised to redness in a gas flame at one spot, and kept hot for some minutes, while the rest of the mass remains sufficiently cool to be held comfortably in the fingers. In the second place, commercial carbide exists in masses of highly irregular shape, so that when they are packed into any vessel they only touch at their angles and edges; and accordingly, even if the material were a fairly good heat conductor of itself, the air or gas present between each lump would act as an insulator, protecting the second piece from the heat generated in the first. In the third place, the calcium hydroxide produced as the by-product when calcium carbide is decomposed by water occupies considerably more space than the original carbide--usually two or three times as much space, the exact figures depending upon the conditions in which it is formed--and therefore a carbide container cannot advisedly be charged with more than one-third the quantity of solid which it is apparently capable of holding. The remaining two-thirds of the space is naturally full of air when the container is first put into the generator, but the air is displaced by acetylene as soon as gas production begins. Whether that space, however, is occupied by air, by acetylene, or by a gradually growing loose mass of slaked lime, each separate lump of hot carbide is isolated from its neighbours by a material which is also a very bad heat conductor; and the heat has but little opportunity of distributing itself evenly. Moreover, although iron or steel is a notably better conductor of heat than any of the other substances present in the carbide vessel, it is, as a metal, only a poor conductor, being considerably inferior in this respect to copper. If heat dissipation were the only point to be studied in the construction of an acetylene apparatus, far better results might be obtained by the employment of copper for the walls of the carbide container; and possibly in that case a generator of considerable size, fitted with a water- jacketed decomposing vessel, might be free from the trouble of overheating. Nevertheless it will be seen in Chapter VI. that the use of copper is not permissible for such purposes, its advantages as a good conductor of heat being neutralised by its more important defects. When suitable precautions are not taken to remove the heat liberated in an acetylene apparatus, the temperature of the calcium carbide occasionally rises to a remarkable degree. Investigating this point, Caro has studied the phenomena of heat production in a "dipping" generator-- _i.e._, an apparatus in which a cage of carbide is alternately immersed in and lifted out of a vessel containing water. Using a generator designed to supply five burners, he has found a maximum recording thermometer placed in the gas space of the apparatus to give readings generally between 60° and 100° C.; but in two tests out of ten he obtained temperatures of about 160° C. To determine the actual temperature of the calcium carbide itself, he scattered amongst the carbide charge fragments of different fusible metallic alloys which were known to melt or soften at certain different temperatures. In all his ten tests the alloys melting at 120° C. were fused completely; in two tests other alloys melting at 216° and 240° C. showed signs of fusion; and in one test an alloy melting at 280° C. began to soften. Working with an experimental apparatus constructed on the "dripping" principle-- _i.e._, a generator in which water is allowed to fall in single drops or as a fine stream upon a mass of carbide--with the deliberate object of ascertaining the highest temperatures capable of production when calcium carbide is decomposed in this particular fashion, and employing for the measurement of the heat a Le Chatelier thermo-couple, with its sensitive wires lying among the carbide lumps, Lewes has observed a maximum temperature of 674° C. to be reached in 19 minutes when water was dripped upon 227 grammes of carbide at a speed of about 8 grammes per minute. In other experiments he used a laboratory apparatus designed upon the "dipping" principle, and found maximum temperatures, in four different trials, of 703°, 734°, 754°, and 807° C., which were reached in periods of time ranging from 12 to 17 minutes. Even allowing for the greater delicacy of the instrument adopted by Lewes for measuring the temperature in comparison with the device employed by Caro, there still remains an astonishing difference between Caro's maximum of 280° and Lewes' maximum of 807° C. The explanation of this discrepancy is to be inferred from what has just been said. The generator used by Caro was properly made of metal, was quite small in size, was properly designed with some skill to prevent overheating as much as possible, and was worked at the speed for which it was intended--in a word, it was as good an apparatus as could be made of this particular type. Lewes' generator was simply a piece of glass and metal, in which provisions to avoid overheating were absent; and therefore the wide difference between the temperatures noted does not suggest any inaccuracy of observation or experiment, but shows what can be done to assist in the dissipation of heat by careful arrangement of parts. The difference in temperature between the acetylene and the carbide in Caro's test accentuates the difficulty of gauging the heat in a carbide vessel by mere external touch, and supplies experimental proof of the previous assertions as to the low heat-conducting power of calcium carbide and of the gases of the decomposing vessel. It must not be supposed that temperatures such as Lewes has found ever occur in any commercial generator of reasonably good design and careful construction; they must be regarded rather as indications of what may happen in an acetylene apparatus when the phenomena accompanying the evolution of gas are not understood by the maker, and when all the precautions which can easily be taken to avoid excessive heating have been omitted, either by building a generator with carbide in excess too large in size, or by working it too rapidly, or more generally by adopting a system of construction unsuited to the ends in view. The fact, however, that Lewes has noted the production of a temperature of 807° C. is important; because this figure is appreciably above the point 780° C., at which acetylene decomposes into its elements in the absence of air. Nevertheless the production of a temperature somewhat exceeding 100° C. among the lumps of carbide actually undergoing decomposition can hardly be avoided in any practical generator. Based on a suggestion in the "Report of the Committee on Acetylene Generators" which was issued by the British Home Office in 1902, Fouché has proposed that 130° C., as measured with the aid of fusible metallic rods, [Footnote: An alloy made by melting together 55 parts by weight of commercial bismuth and 45 parts of lead fuses at 127° C., and should be useful in performing the tests.] should be considered the maximum permissible temperature in any part of a generator working at full speed for a prolonged period of time. Fouché adopts this figure on the ground that 130° C. sensibly corresponds with the temperature at which a yellow substance is formed in a generator by a process of polymerisation; and, referring to French conditions, states that few actual apparatus permit the development of so high a temperature. As a matter of fact, however, a fairly high temperature among the carbide is less important than in the gas, and perhaps it would be better to say that the temperature in any part of a generator occupied by acetylene should not exceed 100° C. Fraenkel has carried out some experiments upon the temperature of the acetylene immediately after evolution in a water-to-carbide apparatus containing the carbide in a subdivided receptacle, using an apparatus now frequently described as belonging to the "drawer" system of construction. When a quantity of about 7 lb. of carbide was distributed between 7 different cells of the receptacle, each cell of which had a capacity of 25 fluid oz., and the apparatus was caused to develop acetylene at the rate of 7 cubic feet per hour, maximum thermometers placed immediately over the carbide in the different cells gave readings of from 70° to 90° C., the average maximum temperature being about 80° C. Hence the Austrian code of rules issued in 1905 governing the construction of acetylene apparatus contains a clause to the effect that the temperature in the gas space of a generator must never exceed 80° C.; whereas the corresponding Italian code contains a similar stipulation, but quotes the maximum temperature as 100° C. (_vide_ Chapter IV.). It is now necessary to see why the production of an excessively high temperature in an acetylene generator has to be avoided. It must be avoided, because whenever the temperature in the immediate neighbourhood of a mass of calcium carbide which is evolving acetylene under the attack of water rises materially above the boiling-point of water, one or more of three several objectionable effects is produced--(_a_) upon the gas generated, (_b_) upon the carbide decomposed, and (_c_) upon the general chemical reaction taking place. It has been stated above that in moat generators when the action between the carbide and the water is proceeding smoothly, it occurs according to equation (2)-- (2) CaC_2 + 2H_2O = C_2H_2 + Ca(OH)_2 rather than in accordance with equation (1)-- (1) CaC_2 + H_2O = C_2H_2 + CaO. This is because calcium oxide, or quicklime, the by-product in (1), has considerable affinity for water, evolving a noteworthy quantity of heat when it combines with one molecule of water to form one molecule of calcium hydroxide, or slaked lime, the by-product in (2). If, then, a small amount of water is added to a large amount of calcium carbide, the corresponding quantity of acetylene may be liberated on the lines of equation (1), and there will remain behind a mixture of unaltered calcium carbide, together with a certain amount of calcium oxide. Inasmuch as both these substances possess an affinity for water (setting heat free when they combine with it), when a further limited amount of water is introduced into the mixture some of it will probably be attracted to the oxide instead of to the carbide present. It is well known that at ordinary temperatures quicklime absorbs moisture, or combines with water, to produce slaked lime; but it is equally well known that in a furnace, at about a red heat, slaked lime gives up water and changes into quicklime. The reaction, in fact, between calcium oxide and water is reversible, and whether those substances combine or dissociate is simply a question of temperature. In other words, as the temperature rises, the heat of hydration of calcium oxide diminishes, and calcium hydroxide becomes constantly a less stable material. If now it should happen that the affinity between calcium carbide and water should not diminish, or should diminish in a lower ratio than the affinity between calcium oxide and water as the temperature of the mass rises from one cause or other, it is conceivable that at a certain temperature calcium carbide might be capable of withdrawing the water of hydration from the molecule of slaked lime, converting the latter into quicklime, and liberating one molecule of acetylene, thus-- (3) CaC_2 + Ca_2(OH) = C_2H_2 + 2CaO. It has been proved that a reaction of this character does occur, the temperature necessary to determine it being given by Lewes as from 420° to 430° C., which is not much more than half that which he found in a generator having carbide in excess, albeit one of extremely bad design. Treating this reaction in the manner previously adopted, the thermo- chemical phenomena of equation (3) are: _Heat liberated._ | _Heat liberated._ | Formation of 2CaO 290.0 | Formation of acetylene 58.1 | Decomposition of Ca(OH)_2 [1] 229.1 | Decomposition of carbide 3.9 Balance 1.1 | ______ | _____ | 291.1 | 291.1 [1 Footnote: Into its elements, Ca, O_2, and H_2; _cf._ footnote, p: 31.] Or, since the calcium hydroxide is only dehydrated without being entirely decomposed, and only one molecule of water is broken up, it may be written: Formation of CaO 145.0 | Formation of acetylene 58.1 | Decomposition of Ca(OH)_2 15.1 | Decomposition of water 69.0 Balance 1.1 | Decomposition of carbide 3.9 _____ | _____ | 146.1 | 146.1 which comes to the same thing. Putting the matter in another shape, it may be said that the reaction between calcium carbide and water is exothermic, evolving either 14.0 or 29.1 calories according as the byproduct is calcium oxide or solid calcium hydroxide; and therefore either reaction proceeds without external assistance in the cold. The reaction between carbide and slaked lime, however, is endothermic, absorbing 1.1 calories; and therefore it requires external assistance (presence of an elevated temperature) to start it, or continuous introduction of heat (as from the reaction between the rest of the carbide present and the water) to cause it to proceed. Of itself, and were it not for the disadvantages attending the production of a temperature remotely approaching 400° C. in an acetylene generator, which disadvantages will be explained in the following paragraphs, there is no particular reason why reaction (3) should not be permitted to occur, for it involves (theoretically) no loss of acetylene, and no waste of calcium carbide. Only one specific feature of the reaction has to be remembered, and due practical allowance made for it. The reaction represented by equation (2) proceeds almost instantaneously when the calcium carbide is of ordinarily good quality, and the acetylene resulting therefrom is wholly generated within a very few minutes. Equation (3), on the contrary, consumes much time for its completion, and the gas corresponding with it is evolved at a gradually diminishing speed which may cause the reaction to continue for hours--a circumstance that may be highly inconvenient or quite immaterial according to the design of the apparatus. When, however, it is desired to construct an automatic acetylene generator, _i.e._, an apparatus in which the quantity of gas liberated has to be controlled to suit the requirements of any indefinite number of burners in use on different occasions, equation (3) becomes a very important factor in the case. To determine the normal reaction (No. 2) of an acetylene generator, 64 parts by weight of calcium carbide must react with 36 parts of water to yield 26 parts by weight of acetylene, and apparently both carbide and water are entirely consumed; but if opportunity is given for the occurrence of reaction (3), another 64 parts by weight of carbide may be attacked, without the addition of any more water, producing, inevitably, another 26 parts of acetylene. If, then, water is in chemical excess in the generator, all the calcium carbide present will be decomposed according to equation (2), and the action will take place without delay; after a few minutes' interval the whole of the acetylene capable of liberation will have been evolved, and nothing further can possibly happen until another charge of carbide is inserted in the apparatus. If, on the other hand, calcium carbide is in chemical excess in the generator, all the water run in will be consumed according to equation (2), and this action will again take place without delay; but unless the temperature of the residual carbide has been kept well below 400° C., a further evolution of gas will occur which will not cease for an indeterminate period of time, and which, by strict theory, given the necessary conditions, might continue until a second volume of acetylene equal to that liberated at first had been set free. In practice this phenomenon of a secondary production of gas, which is known as "after-generation," is regularly met with in all generators where the carbide is in excess of the water added; but the amount of acetylene so evolved rarely exceeds one-quarter or one-third of the main make. The actual amount evolved and the rate of evolution depend, not merely upon the quantity of undecomposed carbide still remaining in contact with the damp lime, but also upon the rapidity with which carbide naturally decomposes in presence of liquid water, and the size of the lumps. Where "after-generation" is caused by the ascent of water vapour round lumps of carbide, the volume of gas produced in a given interval of time is largely governed by the temperature prevailing and the shape of the apparatus. It is evident that even copious "after-generation" is a matter of no consequence in any generator provided with a holder to store the gas, assuming that by some trustworthy device the addition of water is stopped by the time that the holder is two-thirds or three-quarters full. In the absence of a holder, or if the holder fitted is too small to serve its proper purpose, "aftergeneration" is extremely troublesome and sometimes dangerous, but a full discussion of this subject must be postponed to the next chapter. EFFECT OF HEAT ON ACETYLENE.--The effect of excessive retention of heat in an acetylene generator upon the gas itself is very marked, as acetylene begins spontaneously to suffer change, and to be converted into other compounds at elevated temperatures. Being a purely chemical phenomenon, the behaviour of acetylene when exposed to heat will be fully discussed in Chapter VI. when the properties of the gas are being systematically dealt with. Here it will be sufficient to assume that the character of the changes taking place is understood, and only the practical results of those changes as affecting the various components of an acetylene installation have to be studied. According to Lewes, acetylene commences to "polymerise" at a temperature of about 600° C., when it is converted into other hydrocarbons having the same percentage composition, but containing more atoms of carbon and hydrogen in their molecules. The formula of acetylene is C_2H_2 which means that 2 atoms of carbon and 2 atoms of hydrogen unite to form 1 molecule of acetylene, a body evidently containing roughly 92.3 per cent. by weight of carbon and 7.7 per cent. by weight of hydrogen. One of the most noteworthy substances produced by the polymerisation of acetylene is benzene, the formula of which is C_6H_6, and this is formed in the manner indicated by the equation-- (4) 3C_2H_2 = C_6H_6. Now benzene also contains 92.3 per cent. of carbon and 7.7 per cent. by weight of hydrogen in its composition, but its molecule contains 6 atoms of each element. When the chemical formula representing a compound body indicates a substance which is, or can be obtained as, a gas or vapour, it convoys another idea over and above those mentioned on a previous page. The formula "C_2H_2," for example, means 1 molecule, or 26 parts by weight of acetylene, just as "H_2" means 1 molecule, or 2 parts by weight of hydrogen; but both formulæ also mean equal parts by volume of the respective substances, and since H_2 must mean 2 volumes, being twice H, which is manifestly 1, C_2H_2 must mean 2 volumes of acetylene as well. Thus equation (4) states that 6 volumes of acetylene, or 3 x 26 parts by weight, unite to form 2 volumes of benzene, or 78 parts by weight. If these hydrocarbons are burnt in air, both are indifferently converted into carbon dioxide (carbonic acid gas) and water vapour; and, neglecting for the sake of simplicity the nitrogen of the atmosphere, the processes may be shown thus: (5) 2C_2H_2 + 5O_2 = 4CO_2 + 2H_2O. (6) 2C_6H_6 + 15O_2 = 12CO_2 + 6H_2O. Equation (5) shows that 4 volumes of acetylene combine with 10 volumes of oxygen to produce 8 volumes of carbon dioxide and 4 of water vapour; while equation (6) indicates that 4 volumes of benzene combine with 30 volumes of oxygen to yield 24 volumes of carbon dioxide and 12 of water vapour. Two parts by volume of acetylene therefore require 5 parts by volume of oxygen for perfect combustion, whereas two parts by volume of benzene need 15--_i.e._, exactly three times as much. In order to work satisfactorily, and to develop the maximum of illuminating power from any kind of gas consumed, a gas-burner has to be designed with considerable skill so as to attract to the base of the flame precisely that volume of air which contains the quantity of oxygen necessary to insure complete combustion, for an excess of air in a flame is only less objectionable than a deficiency thereof. If, then, an acetylene burner is properly constructed, as most modern ones are, it draws into the flame air corresponding with two and a half volumes of oxygen for every one volume of acetylene passing from the jets; whereas if it were intended for the combustion of benzene vapour it would have to attract three times that quantity. Since any flame supplied with too little air tends to emit free carbon or soot, it follows that any well-made acetylene burner delivering a gas containing benzene vapour will yield a more or lens smoky flame according to the proportion of benzene in the acetylene. Moreover, at ordinary temperatures benzene is a liquid, for it boils at 81° C., and although, as was explained above in the case of water, it is capable of remaining in the state of vapour far below its boiling-point so long as it is suspended in a sufficiency of some permanent gas like acetylene, if the proportion of vapour in the gas at any given temperature exceeds a certain amount the excess will be precipitated in the liquid form; while as the temperature falls the proportion of vapour which can be retained in a given volume of gas also diminishes to a noteworthy extent. Should any liquid, be it water or benzene, or any other substance, separate from the acetylene under the influence of cold while the gas is passing through pipes, the liquid will run downwards to the lowest points in those pipes; and unless due precautions are taken, by the insertion of draw-off cocks, collecting wells, or the like, to withdraw the deposited water or other liquid, it will accumulate in all bends, angles, and dips till the pipes are partly or completely sealed against the passage of gas, and the lights will either "jump" or be extinguished altogether. In the specific case of an acetylene generator this trouble is very likely to arise, even when the gas is not heated sufficiently during evolution for polymerisation to occur and benzene or other liquid hydrocarbons to be formed, because any excess of water present in the decomposing vessel is liable to be vaporised by the heat of the reaction--as already stated it is desirable that water shall be so vaporised--and will remain safely vaporised as long as the pipes are kept warm inside or near the generator; but directly the pipes pass away from the hot generator the cooling action of the air begins, and some liquid water will be immediately produced. Like the phenomenon of after- generation, this equally inevitable phenomenon of water condensation will be either an inconvenience or source of positive danger, or will be a matter of no consequence whatever, simply as the whole acetylene installation, including the service-pipes, is ignorantly or intelligently built. As long as nothing but pure polymerisation happens to the acetylene, as long, that is to say, as it is merely converted into other hydrocarbons also having the general formula C_(2n)H_(2n), no harm will be done to the gas as regards illuminating power, for benzene burns with a still more luminous flame than acetylene itself; nor will any injury result to the gas if it is required for combustion in heating or cooking stoves beyond the fact that the burners, luminous or atmospheric, will be delivering a material for the consumption of which they are not properly designed. But if the temperature should rise much above the point at which benzene is the most conspicuous product of polymerisation, other far more complicated changes occur, and harmful effects may be produced in two separate ways. Some of the new hydrocarbons formed may interact to yield a mixture of one or more other hydrocarbons containing a higher proportion of carbon than that which is present in acetylene and benzene, together with a corresponding proportion of free hydrogen; the former will probably be either liquids or solids, while the latter burns with a perfectly non-luminous flame. Thus the quantity of gas evolved from the carbide and passed into the holder is less than it should be, owing to the condensation of its non-gaseous constituents. To quote an instance of this, Haber has found 15 litres of acetylene to be reduced in volume to 10 litres when the gas was heated to 638° C. By other changes, some "saturated hydrocarbons," _i.e._, bodies having the general formula C_nH_(2n+2), of which methane or marsh-gas, CH_4 is the best known, may be produced; and those all possess lower illuminating powers than acetylene. In two of those experiments already described, where Lewes observed maximum temperatures ranging from 703° to 807° C., samples of the gas which issued when the heat was greatest were submitted to chemical analysis, and their illuminating powers were determined. The figures he gives are as follows: I. II. Per Cent. Per Cent. Acetylene 70.0 69.7 Saturated hydrocarbons 11.3 11.4 Hydrogen 18.7 18.9 _____ _____ 100.0 100.0 The average illuminating power of these mixed gases is about 126 candles per 5 cubic feet, whereas that of pure acetylene burnt under good laboratory conditions is 240 candles per 5 cubic feet. The product, it will be seen, had lost almost exactly 50 per cent. of its value as an illuminant, owing to the excessive heating to which it had been, exposed. Some of the liquid hydrocarbons formed at the same time are not limpid fluids like benzene, which is less viscous than water, but are thick oily substances, or even tars. They therefore tend to block the tubes of the apparatus with great persistence, while the tar adheres to the calcium carbide and causes its further attack by water to be very irregular, or even altogether impossible. In some of the very badly designed generators of a few years back this tarry matter was distinctly visible when the apparatus was disconnected for recharging, for the spent carbide was exceptionally yellow, brown, or blackish in colour, [Footnote: As will be pointed out later, the colour of the spent lime cannot always be employed as a means for judging whether overheating has occurred in a generator.] and the odour of tar was as noticeable as that of crude acetylene. There is another effect of heat upon acetylene, more calculated to be dangerous than any of those just mentioned, which must not be lost sight of. Being an endothermic substance, acetylene is prone to decompose into its elements-- (7) C_2H_2 -> C_2 + H_2 whenever it has the opportunity; and the opportunity arrives if the temperature of the gas risen to 780° C., or if the pressure under which the gas is stored exceeds two atmospheres absolute (roughly 30 lb. per square inch). It decomposes, be it carefully understood, in the complete absence of air, directly the smallest spark of red-hot material or of electricity, or directly a gentle shock, such as that of a fall or blow on the vessel holding it, is applied to any volume of acetylene existing at a temperature exceeding 780° or at a gross pressure of 30 lb. per square inch; and however large that volume may be, unless it is contained in tubes of very small diameter, as will appear hereafter, the decomposition or dissociation into its elements will extend throughout the whole of the gas. Equation (7) states that 2 volumes of acetylene yield 2 volumes of hydrogen and a quantity of carbon which would measure 2 volumes were it obtained in the state of gas, but which, being a solid, occupies a space that may be neglected. Apparently, therefore, the dissociation of acetylene involves no alteration in volume, and should not exhibit explosive effects. This is erroneous, because 2 volumes of acetylene only yield exactly 2 volumes of hydrogen when both gases are measured at the same temperature, and all gases increase in volume as their temperature rises. As acetylene is endothermic and evolves much heat on decomposition, and as that heat must primarily be communicated to the hydrogen, it follows that the latter must be much hotter than the original acetylene; the hydrogen accordingly strives to fill a much larger space than that occupied by the undecomposed gas, and if that gas is contained in a closed vessel, considerable internal pressure will be set up, which may or may not cause the vessel to burst. What has been said in the preceding paragraph about the temperature at which acetylene decomposes is only true when the gas is free from any notable quantity of air. In presence of air, acetylene inflames at a much lower temperature, viz., 480° C. In a manner precisely similar to that of all other combustible gases, if a stream of acetylene issues into the atmosphere, as from the orifices of a burner, the gas catches fire and burns quietly directly any substance having a temperature of 480° C. or upwards is brought near it; but if acetylene in bulk is mixed with the necessary quantity of air to support combustion, and any object exceeding 480° C. in temperature comes in contact with it, the oxidation of the hydrocarbon proceeds at such a high rate of speed as to be termed an explosion. The proportion of air needed to support combustion varies with every combustible material within known limits (_cf._ Chapter VI.), and according to Eitner the smallest quantity of air required to make acetylene burn or explode, as the case may be, is 25 per cent. If, by ignorant design or by careless manipulation, the first batches of acetylene evolved from a freshly charged generator should contain more than 25 per cent. of air; or if in the inauguration of a new installation the air should not be swept out of the pipes, and the first makes of gas should become diluted with 25 to 50 per cent. of air, any glowing body whose temperature exceeds 480° C. will fire the gas; and, as in the former instance, the flame will extend all through the mass of acetylene with disastrous violence and at enormous speed unless the gas is stored in narrow pipes of extremely small diameter. Three practical lessons are to be learnt from this circumstance: first, tobacco-smoking must never be permitted in any building where an escape of raw acetylene is possible, because the temperature of a lighted cigar, &c., exceeds 480° C.; secondly, a light must never be applied to a pipe delivering acetylene until a proper acetylene burner has been screwed into the aperture; thirdly, if any appreciable amount of acetylene is present in the air, no operation should be performed upon any portion of an acetylene plant which involves such processes as scraping or chipping with the aid of a steel tool or shovel. If, for example, the iron or stoneware sludge-pipe is choked, or the interior of the dismantled generator is blocked, and attempts are made to remove the obstruction with a hard steel tool, a spark is very likely to be formed which, granting the existence of sufficient acetylene in the air, is perfectly able to fire the gas. For all such purposes wooden implements only are best employed; but the remark does not apply to the hand-charging of a carbide-to-water generator through its proper shoot. Before passing to another subject, it may be remarked that a quantity of air far less than that which causes acetylene to become dangerous is objectionable, as its presence is apt to reduce the illuminating power of the gas unduly. EFFECT OF HEAT ON CARBIDE.--Chemically speaking, no amount of heat possible of attainment in the worst acetylene generator can affect calcium carbide in the slightest degree, because that substance may be raised to almost any temperature short of those distinguishing the electric furnace, without suffering any change or deterioration. In the absence of water, calcium carbide is as inert a substance as can well be imagined: it cannot be made to catch fire, for it is absolutely incombustible, and it can be heated in any ordinary flame for reasonable periods of time, or thrown into any non-electrical furnace without suffering in the least. But in presence of water, or of any liquid containing water, matters are different. If the temperature of an acetylene generator rises to such an extent that part of the gas is polymerised into tar, that tar naturally tends to coat the residual carbide lumps, and, being greasy in character, more or less completely protects the interior from further attack. Action of this nature not only means that the acetylene is diminished in quantity and quality by partial decomposition, but it also means that the make is smaller owing to imperfect decomposition of the carbide: while over and above this is the liability to nuisance or danger when a mass of solid residue containing some unaltered calcium carbide is removed from the apparatus and thrown away. In fact, whenever the residue of a generator is not so saturated with excess of water as to be of a creamy consistency, it should be put into an uncovered vessel in the open air, and treated with some ten times its volume of water before being run into any drain or closed pipe where an accumulation of acetylene may occur. Even at temperatures far below those needed to determine a production of tar or an oily coating on the carbide, if water attacks an excess of calcium carbide somewhat rapidly, there is a marked tendency for the carbide to be "baked" by the heat produced; the slaked lime adhering to the lumps as a hard skin which greatly retards the penetration of more water to the interior. COLOUR OF SPENT CARBIDE.--In the early days of the industry, it was frequently taken for granted that any degradation in the colour of the spent lime left in an acetylene generator was proof that overheating had taken place during the decomposition of the carbide. Since both calcium oxide and hydroxide are white substances, it was thought that a brownish, greyish, or blackish residue must necessarily point to incipient polymerisation of the gas. This view would be correct if calcium carbide were prepared in a state of chemical purity, for it also is a white body. Commercial carbide, however, is not pure; it usually contains some foreign matter which tints the residue remaining after gasification. When a manufacturer strives to give his carbide the highest gas-making power possible he frequently increases the proportion of carbon in the charge submitted to electric smelting, until a small excess is reached, which remains in the free state amongst the finished carbide. After decomposition the fine particles of carbon stain the moist lime a bluish grey tint, the depth of shade manifestly depending upon the amount present. If such a sludge is copiously diluted with water, particles of carbon having the appearance and gritty or flaky nature of coke often rise to the surface or fall to the bottom of the liquid; whence they can easily be picked out and identified as pure or impure carbon by simple tests. Similarly the lime or carbon put into the electric furnace may contain small quantities of compounds which are naturally coloured; and which, reappearing in the sludge either in their original or in a different state of combination, confer upon the sludge their characteristic tinge. Spent lime of a yellowish brown colour is frequently to be met with in circumstances that are clearly no reproach to the generator. Doubtless the tint is due to the presence of some coloured metallic oxide or other compound which has escaped reduction in the electric furnace. The colour which the residual lime afterwards assumes may not be noticeable in the dry carbide before decomposition, either because some change in the colour-giving impurity takes place during the chemical reactions in the generator or because the tint is simply masked by the greyish white of the carbide and its free carbon. Hence it follows that a bad colour in the waste lime removed from a generator only points to overheating and polymerisation of the acetylene when corroborative evidence is obtained--such as a distinct tarry smell, the actual discovery of oily or tarry matters elsewhere, or a grave reduction in the illuminating power of the gas. MAXIMUM ATTAINABLE TEMPERATURES.--In order to discover the maximum temperature which can be reached in or about an acetylene generator when an apparatus belonging to one of the best types is fed at a proper rate with calcium carbide in lumps of the most suitable size, the following calculation may be made. In the first place, it will be assumed that no loss of heat by radiation occurs from the walls of the generator; secondly, the small quantity of heat taken up by the calcium hydroxide produced will be ignored; and, thirdly, the specific heat of acetylene will be assumed to be 0.25, which is about its most probable value. Now, a hand-fed carbide-to-water generator will work with half a gallon of water for every 1 lb. of carbide decomposed, quantities which correspond with 320 grammes of water per 64 grammes (1 molecular weight) of carbide. Of those 320 grammes of water, 18 are chemically destroyed, leaving 302. The decomposition of 64 grammes of commercial carbide evolves 28 large calories of heat. Assuming all the heat to be absorbed by the water, 28 calories would raise 302 grammes through (28 X 1000 / 302) = 93° C., _i.e._, from 44.6° F. to the boiling-point. Assuming all the heat to be communicated to the acetylene, those 28 calories would raise the 26 grammes of gas liberated through (28 X 1000 / 26 / 0.25) = 4308° C., if that were possible. But if, as would actually be the case, the heat were distributed uniformly amongst the 302 grammes of water and the 20 grammes of acetylene, both gas and water would be raised through the same number of degrees, viz., 90.8° C. [Footnote: Let x = the number of large calories absorbed by the water; then 28 - x = those taken up by the gas. Then-- 1000x / 302 = 1000 (28 - x) / (26 X 0.25) whence x = 27.41; and 28 - x = 0.59. Therefore, for water, the rise in temperature is-- 27.41 X 1000 / 302 = 90.8° C.; and for acetylene the rise is-- 0.59 X 1000 / 26 / 0.25 = 90.8° C.] If the generator were designed on lines to satisfy the United States Fire Underwriters, it would contain 8.33 lb. of water to every 1 lb. of carbide attacked; identical calculations then showing that the original temperature of the water and gas would be raised through 53.7° C. Provided the carbide is not charged into such an apparatus in lumps of too large a size, nor at too high a rate, there will be no appreciable amount of local overheating developed; and nowhere, therefore, will the rise in temperature exceed 91° in the first instance, or 54° C. in the second. Indeed it will be considerably smaller than this, because a large proportion of the heat evolved will be lost by radiation through the generator walls, while another portion will be converted from sensible into latent heat by causing part of the water to pass off as vapour with the acetylene. EFFECT OF HIGH TEMPERATURES ON GENERATORS.--As the temperature amongst the carbide in any generator in which water is not present in large excess may easily reach 200° C. or upwards, no material ought to be employed in the construction of such generators which is not competent to withstand a considerable amount of heat in perfect safety. The ordinary varieties of soft solder applied with the bitt in all kinds of light metal-work usually melt, according to their composition, at about 180° C.; and therefore this method of making joints is only suitable for objects that are never raised appreciably in temperature above the boiling-point of water. No joint in an acetylene generator, the partial or complete failure of which would radically affect the behaviour of the apparatus, by permitting the charges of carbide and of water to come into contact at an abnormal rate of speed, by allowing the acetylene to escape directly through the crack into the atmosphere, or by enabling the water to run out of the seal of any vessel containing gas so as to set up a free communication between that vessel and the air, ought ever to be made of soft solder--every joint of this character should be constructed either by riveting, by bolting, or by doubly folding the metal sheets. Apparently, a joint constantly immersed in water on one side cannot rise in temperature above the boiling-point of the liquid, even when its other side is heated strongly; but since, even if a generator is not charged with naturally hard water, its fluid contents soon become "hard" by dissolution of lime, there is always a liability to the deposition of water scale over the joint. Such water scale is a very bad heat conductor, as is seen in steam boilers, so that a seam coated with an exceedingly thin layer of scale, and heated sharply on one side, will rise above the boiling-point of water even if the liquid on its opposite side is ice-cold. For a while the film of scale may be quite water-tight, but after it has been heated by contact with the hot metal several times it becomes brittle and cracks without warning. But there is a more important reason for avoiding the use of plumbers' solder. It might seem that as the natural hard, protective skin of the metal is liable to be injured or removed by the bending or by the drilling or punching which precedes the insertion of the rivets or studs, an application of soft solder to such a joint should be advantageous. This is not true because of the influence of galvanic action. As all soft solders consist largely of lead, if a joint is soldered, a "galvanic couple" of lead and iron, or of lead and zinc (when the apparatus is built of galvanised steel), is exposed to the liquid bathing it; and since in both cases the lead is highly electro-negative to the iron or zinc, it is the iron or zinc which suffers attack, assuming the liquid to possess any corrosive properties whatever. Galvanised iron which has been injured during the joint-making presents a zinc-iron couple to the water, but the zinc protects the iron; if a lead solder is present, the iron will begin to corrode immediately the zinc has disappeared. In the absence of lead it is the less important metal, but in the presence of lead it is the more important (the foundation) metal which is the soluble element of the couple. Where practicable, joints in an acetylene generator may safely be made by welding or by autogenous soldering ("burning"), because no other metal is introduced into the system; any other process, except that of riveting or folding, only hastens destruction of the plant. The ideal method of making joints about an acetylene generator is manifestly that of autogenous soldering, because, as will appear in Chapter IX. of this book, the most convenient and efficient apparatus for performing the operation is the oxy-acetylene blow-pipe, which can be employed so as to convert two separate pieces of similar metal into one homogeneous whole. In less critical situations in an acetylene plant, such as the partitions of a carbide container, &c., where the collapse of the seam or joint would not be followed by any of the effects previously suggested, there is less cause for prohibiting the use of unfortified solder; but even here, two or three rivets, just sufficient to hold the metal in position if the solder should give way, are advisedly put into all apparatus. In other portions of an acetylene installation where a merely soldered joint is exposed to warm damp gas which is in process of cooling, instead of being bathed in hard water, an equal, though totally dissimilar, danger is courted. The main constituent of such solders that are capable of being applied with the bitt is lead; lead is distinctly soluble in soft or pure water; and the water which separates by condensation out of a warm damp gas is absolutely soft, for it has been distilled. If condensation takes place at or near a soldered joint in such a way that water trickles over the solder, by slow degrees the metallic lead will be dissolved and removed, and eventually a time will come when the joint is no longer tight to gas. In fact, if an acetylene installation is of more than very small dimensions, _e.g._, when it is intended to supply any building as large as, or larger than, the average country residence, if it is to give satisfaction to both constructor and purchaser by being quite trustworthy and, possessed of a due lease of life, say ten or fifteen years, it must be built of stouter materials than the light sheets which alone are suitable for manipulation with the soldering-iron or for bending in the ordinary type of metal press. Sound cast-iron, heavy sheet-metal, or light boiler-plate is the proper substance of which to construct all the important parts of a generator, and the joints in wrought metal must be riveted and caulked or soldered autogeneously as mentioned above. So built, the installation becomes much more costly to lay down than an apparatus composed of tinplate, zinc, or thin galvanised iron, but it will prove more economical in the long run. It is not too much to say that if ignorant and short-sighted makers in the earliest days of the acetylene industry had not recommended and supplied to their customers lightly built apparatus which has in many instances already begun to give trouble, to need repairs, and to fail by thorough corrosion--apparatus which frequently had nothing but cheapness in its favour--the use of the gas would have spread more rapidly than it has done, and the public would not now be hearing of partial or complete failures of acetylene installations. Each of these failures, whether accompanied by explosions and injury to persons or not, acts more powerfully to restrain a possible new customer from adopting the acetylene light, than several wholly successful plants urge him to take it up; for the average member of the public is not in a position to distinguish properly between the collapse of a certain generator owing to defective design or construction (which reflects no discredit upon the gas itself), and the failure of acetylene to show in practice those advantages that have been ascribed to it. One peculiar and noteworthy feature of acetylene, often overlooked, is that the apparatus is constructed by men who may have been accustomed to gas-making plant all their lives, and who may understand by mere habit how to superintend a chemical operation; but the same apparatus is used by persons who generally have no special acquaintance with such subjects, and who, very possibly, have not even burnt coal-gas at any period of their lives. Hence it happens that when some thoughtless action on the part of the country attendant of an acetylene apparatus is followed by an escape of gas from the generator, and by an accumulation of that gas in the house where the plant is situated, or when, in disregard of rules, he takes a naked light into the house and an explosion follows, the builder dismisses the episode as a piece of stupidity or wilful misbehaviour for which he can in nowise be held morally responsible; whereas the builder himself is to blame for designing an apparatus from which an escape of gas can be accompanied by sensible risks to property or life. However unpalatable this assertion may be, its truth cannot be controverted; because, short of criminal intention or insanity on the part of the attendant, it is in the first place a mere matter of knowledge and skill so to construct an acetylene plant that an escape of gas is extremely unlikely, even when the apparatus is opened for recharging, or when it is manipulated wrongly; and in the second place, it is easy so to arrange the plant that any disturbance of its functions which may occur shall be followed by an immediate removal of the surplus gas into a place of complete safety outside and above the generator-house. GENERATION AT LOW TEMPERATURES.--In all that has been said hitherto about the reaction between calcium carbide and water being instantaneous, it has been assumed that the two substances are brought together at or about the usual temperature of an occupied room, _i.e._, 15 degrees C. If, however, the temperature is materially lower than this, the speed of the reaction falls off, until at -5 degrees C., supposing the water still to remain liquid, evolution of acetylene practically ceases. Even at the freezing-point of pure water gas is produced but slowly; and if a lump of carbide is thrown on to a block of ice, decomposition proceeds so gently that the liberated acetylene may be ignited to form a kind of torch, while heat is generated with insufficient rapidity to cause the carbide to sink into the block. This fact has very important bearings upon the manipulation of an acetylene generator in winter time. It is evident that unless precautions are taken those portions of an apparatus which contain water are liable to freeze on a cold night; because, even if the generator has been at work producing gas (and consequently evolving heat) till late in the evening, the surplus heat stored in the plant may escape into the atmosphere long before more acetylene has to be made, and obviously while frost is still reigning in the neighbourhood. If the water freezes in the water store, in the pipes leading therefrom, in the holder seal, or in the actual decomposing chamber, a fresh batch of gas is either totally incapable of production, because the water cannot be brought into contact with the calcium carbide in the apparatus, or it can only be generated with excessive slowness because the carbide introduced falls on to solid ice. Theoretically, too, there is a possibility that some portion of the apparatus--a pipe in particular--may be burst by the freezing, owing to the irresistible force with which water expands when it changes into the solid condition. Probably this last contingency, clearly accompanied as it would be by grave risk, is somewhat remote, all the plant being constructed of elastic material; but in practice even a simple interference with the functions of a generator by freezing, ideally of no special moment, is highly dangerous, because of the great likelihood that hurried and wholly improper attempts to thaw it will be made by the attendant. As it has been well known for many years that the solidifying point of water can be lowered to almost any degree below normal freezing by dissolving in it certain salts in definite proportions, one of the first methods suggested for preventing the formation of ice in an acetylene generator was to employ such a salt, using, in fact, for the decomposition of the carbide some saline solution which remains liquid below the minimum night temperature of the winter season. Such a process, however, has proved unsuitable for the purpose in view; and the explanation of that fact is found in what has just been stated: the "water" of the generator may admittedly be safely maintained in the fluid state, but from so cold a liquid acetylene will not be generated smoothly, if at all. Moreover, were it not so, a process of this character is unnecessarily expensive, although suitable salts are very cheap, for the water of the generator is constantly being consumed, [Footnote: It has already been said that most generators "consume" a much larger volume of water than the amount corresponding with the chemical reaction involved: the excess of water passing into the sludge or by- product. Thus a considerable quantity of any anti-freezing agent must be thrown aside each time the apparatus is cleaned out or its fluid contents are run off.] and as constantly needs renewal; which means that a fresh batch of salt would be required every time the apparatus was recharged, so long as frost existed or might be expected. A somewhat different condition obtains in the holder of an acetylene installation. Here, whenever the holder is a separate item in the plant, not constituting a portion of the generating apparatus, the water which forms the seal of a rising holder, or which fills half the space of a displacement holder, lasts indefinitely; and it behaves equally well, whatever its temperature may be, so long as it retains a fluid state. This matter will be discussed with greater detail at the end of Chapter III. At present the point to be insisted on is that the temperature in any constituent of an acetylene installation which contains water must not be permitted to fall to the freezing-point; while the water actually used for decomposition must be kept well above that temperature. GENERATION AT HIGH TEMPERATURES.--At temperatures largely exceeding those of the atmosphere, the reaction between calcium carbide and water tends to become irregular; while at a red heat steam acts very slowly upon carbide, evolving a mixture of acetylene and hydrogen in place of pure acetylene. But since at pressures which do not materially exceed that of the atmosphere, water changes into vapour at 100° C., above that temperature there can be no question of a reaction between carbide and liquid water. Moreover, as has been pointed out, steam or water vapour will continue to exist as such at temperatures even as low as the freezing-point so long as the vapour is suspended among the particles of a permanent gas. Between calcium carbide and water vapour a double decomposition occurs chemically identical with that between carbide and liquid water; but the physical effect of the reaction and its practical bearings are considerably modified. The quantity of heat liberated when 30 parts by weight of steam react with 64 parts of calcium carbide should be essentially unaltered from that evolved when the reagent is in the liquid state; but the temperature likely to be attained when the speed of reaction remains the same as before will be considerably higher for two conspicuous reasons. In the first place, the specific heat of steam in is only 0.48, while that of liquid water is 1.0. Hence, the quantity of heat which is sufficient to raise the temperature of a given weight of liquid water through _n_ thermometric degrees, will raise the temperature of the same weight of water vapour through rather more than 2 _n_ degrees. In the second place, that relatively large quantity of heat which in the case of liquid water merely changes the liquid into a vapour, becoming "latent" or otherwise unrecognisable, and which, as already shown, forms roughly five-sixths of the total heat needed to convert cold water into steam, has no analogue if the water has previously been vaporised by other means; and therefore the whole of the heat supplied to water vapour raises its sensible temperature, as indicated by the thermometer. Thus it appears that, except for the sufficient amount of cooling that can be applied to a large vessel containing carbide by surrounding it with a water jacket, there is no way of governing its temperature satisfactorily if water vapour is allowed to act upon a mass of carbide--assuming, of course, that the reaction proceeds at any moderate speed, _e.g._, at a rate much above that required to supply one or two burners with gas. The decomposition which with perfect chemical accuracy has been stated to occur quantitatively between 36 parts by weight, of water and 64 parts of calcium carbide scarcely ever takes place in so simple a fashion in an actual generator. Owing to the heat developed when carbide is in excess, about half the water is converted into vapour; and so the reaction proceeds in two stages: half the water added reacting with the carbide as a liquid, the other half, in a state of vapour, afterwards reacting similarly, [Footnote: This secondary reaction is manifestly only another variety of the phenomenon known as "after-generation" (cf. _ante_). After-generation is possible between calcium carbide and mechanically damp slaked lime, between carbide and damp gas, or between carbide and calcium hydroxide, as opportunity shall serve. In all cases the carbide must be in excess.] or hardly reacting at all, as the case may be. Suppose a vessel, A B, somewhat cylindrical in shape, is charged with carbide, and that water is admitted at the end called A. Suppose now (1) that the exit for gas is at the opposite end, B. As the lumps near A are attacked by half the liquid introduced, while the other half is changed into steam, a current, of acetylene and water vapour travels over the charge lying between the decomposing spot and the end B. During its passage the second half of the water, as vapour, reacts with the excess of carbide, the first make of acetylene being dried, and more gas being produced. Thus a second quantity of heat is developed, equal by theory to that previously evolved; but a second elevation in temperature, far more serious, and far less under control, than the former also occurs; and this is easily sufficient to determine some of those undesirable effects already described. Digressing for a moment, it may be admitted that the desiccation of the acetylene produced in this manner is beneficial, even necessary; but the advantages of drying the gas at this period of its treatment are outweighed by the concomitant disadvantages and by the later inevitable remoistening thereof. Suppose now (2) that both the water inlet and the gas exit of the carbide cylinder are at the same end, A. Again half the added water, as liquid, reacts with the carbide it first encounters, but the hot stream of damp gas is not permitted to travel over the rest of the lumps extending towards B: it is forced to return upon its steps, leaving B practically untouched. The gas accordingly escapes from the cylinder at A still loaded with water vapour, and for a given weight of water introduced much less acetylene is evolved than in the former case. The gas, too, needs drying somewhere else in the plant; but these defects are preferable to the apparent superiority of the first process because overheating is, or can be, more thoroughly guarded against. PRESSURE IN GENERATORS.--Inasmuch as acetylene is prone to dissociate or decompose into its elements spontaneously whenever its pressure reaches 2 atmospheres or 30 lb. per square inch, as well as when its temperature at atmospheric pressure attains 780° C., no pressure approaching that of 2 atmospheres is permissible in the generator. A due observance of this rule, however, unlike a proper maintenance of a low temperature in an acetylene apparatus, is perfectly easy to arrange for. The only reason for having an appreciable positive pressure in any form of generating plant is that the gas may be compelled to travel through the pipes and to escape from the burner orifices; and since the plant is only installed to serve the burners, that pressure which best suits the burners must be thrown by the generator or its holder. Therefore the highest pressure it is ever requisite to employ in a generator is a pressure sufficient (_a_) to lift the gasholder bell, or to raise the water in a displacement holder, (_b_) to drive the gas through the various subsidiary items in the plant, such as washers and purifiers, (_c_) to overcome the friction in the service-pipes, [Footnote: This friction manifestly causes a loss of pressure, _i.e._, a fall in pressure, as a gas travels along a pipe; and, as will be shown in Chapter VII., it is the fall in pressure in a pipe rather than the initial pressure at which a gas enters a pipe that governs the volume of gas passing through that pipe. The proper behaviour and economic working of a burner (acetylene or other, luminous or incandescent) naturally depend upon the pressure in the pipe to which the burner is immediately attached being exactly suited to the design of that burner, and have nothing to do with the fall in pressure occurring in the delivery pipes. It is therefore necessary to keep entirely separate the ideas of proper burner pressure and of maximum desirable fall in pressure within the service due to friction.] and (d) to give at the points of combustion a pressure which is required by the particular burners adopted. In all except village or district installations, (_c_) may be virtually neglected. When the holder has a rising bell, (_a_) represents only an inch or so of water; but if a displacement holder is employed the pressure needed to work it is entirely indeterminate, being governed by the size and shape of the said holder. It will be argued in Chapter III. that a rising holder is always preferable to one constructed on the displacement principle. The pressure (d) at the burners may be taken at 4 inches of water as a maximum, the precise figure being dependent upon the kind of burners--luminous, incandescent, boiling, &c.--attached to the main. The pressure (_b_) also varies according to circumstances, but averages 2 or 3 inches. Thus a pressure in the generator exceeding that of the atmosphere by some 12 inches of water--_i.e._, by about 7 oz., or less than half a pound per square inch--is amply sufficient for every kind of installation, the less meritorious generators with displacement holders only excepted. This pressure, it should be noted, is the net or effective pressure, the pressure with which the gas raises the liquid in a water-gauge glass out of the level while the opposite end of the water column is exposed to the atmosphere. The absolute pressure in a vessel containing gas at an effective pressure of 12 inches of water is 7 oz. plus the normal, insensible pressure of the atmosphere itself--say 15-1/4 lb. per square inch. The liquid in a barometer which measures the pressure of the atmosphere stands at a height of 30 inches only, because that liquid is mercury, 13.6 times as heavy as water. Were it filled with water the barometer would stand at (30 X 13.6) = 408 inches, or 34 feet, approximately. Gas pressures are always measured in inches of water column, because expressed either as pounds per square inch or as inches of mercury, the figures would be so small as to give decimals of unwieldy length. It would of course be perfectly safe so to arrange an acetylene plant that the pressure in the generating chamber should reach the 100 inches of water first laid down by the Home Office authorities as the maximum allowable. There is, however, no appreciable advantage to be gained by so doing, or by exceeding that pressure which feeds the burners best. Any higher original pressure involves the use of a governor at the exit of the plant, and a governor is a costly and somewhat troublesome piece of apparatus that can be dispensed with in most single installations by a proper employment of a well-balanced rising holder. CHAPTER III THE GENERAL PRINCIPLES OF ACETYLENE GENERATION--ACETYLENE GENERATING APPARATUS Inasmuch as acetylene is produced by the mere interaction of calcium carbide and water, that is to say, by simply bringing those two substances in the cold into mutual contact within a suitable closed space, and inasmuch as calcium carbide can always be purchased by the consumer in a condition perfectly fit for immediate decomposition, the preparation of the gas, at least from the theoretical aspect, is characterised by extreme simplicity. A cylinder of glass or metal, closed at one end and open at the other, filled with water, and inverted in a larger vessel containing the same liquid, may be charged almost instantaneously with acetylene by dropping into the basin a lump of carbide, which sinks to the bottom, begins to decompose, and evolves a rapid current of gas, displacing the water originally held in the inverted cylinder or "bell." If a very minute hole is drilled in the top of the floating bell, acetylene at once escapes in a steady stream, being driven out by the pressure of the cylinder, the surplus weight of which causes it to descend into the water of the basin as rapidly as gas issues from the orifice. As a laboratory experiment, and provided the bell has been most carefully freed from atmospheric air in the first instance, this escaping gas may be set light to with a match, and will burn with a more or loss satisfactory flame of high illuminating power. Such is an acetylene generator stripped of all desirable or undesirable adjuncts, and reduced to its most elementary form; but it is needless to say that so simple an apparatus would not in any way fulfil the requirements of everyday practice. Owing to the inequality of the seasons, and to the irregular nature of the demand for artificial light and heat in all households, the capacity of the plant installed for the service of any institution or district must be amply sufficient to meet the consumption of the longest winter evening--for, as will be shown in the proper place, attempts to make an acetylene generator evolve gas more quickly than it is designed to do are fraught with many objections--while the operation of the plant, must be under such thorough control that not only can a sudden and unexpected demand for gas be met without delay, but also that a sudden and unexpected interruption or cessation of the demand shall not be followed by any disturbance in the working of the apparatus. Since, on the one hand, acetylene is produced in large volumes immediately calcium carbide is wetted with water, so that the gas may be burnt within a minute or two of its first evolution; and, on the other, that acetylene once prepared can be stored without trouble or appreciable waste for reasonable periods of time in a water-sealed gasholder closely resembling, in everything but size, the holders employed on coal-gas works; it follows that there are two ways of bringing the output of the plant into accord with the consumption of the burners. It is possible to make the gas only as and when it is required, or it is possible in the space of an hour or so, during the most convenient part of the day, to prepare sufficient to last an entire evening, storing it in a gasholder till the moment arrives for its combustion. It is clear that an apparatus needing human attention throughout the whole period of activity would be intolerable in the case of small installations, and would only be permissible in the case of larger ones if the district supplied with gas was populous enough to justify the regular employment of two men at least in or about the generating station. But with the conditions obtaining in such a country as Great Britain, and in other lands where coal is equally cheap and accessible, if a neighbourhood was as thickly populated as has been suggested, it would be preferable on various grounds to lay down a coal- gas or electricity works; for, as has been shown in the first chapter, unless a very material fall in the price of calcium carbide should take place--a fall which at present is not to be expected--acetylene can only be considered a suitable and economical illuminant and heating agent for such places as cannot be provided cheaply with coal-gas or electric current. To meet this objection, acetylene generators have been invented in which, broadly speaking, gas is only produced when it is required, control of the chemical reaction devolving upon some mechanical arrangement. There are, therefore, two radically different types of acetylene apparatus to be met with, known respectively as "automatic" and "non-automatic" generators. In a non-automatic generator the whole of the calcium carbide put into the apparatus is more or less rapidly decomposed, and the entire volume of gas evolved from it is collected in a holder, there to await the moment of consumption. In an automatic apparatus, by means of certain devices which will be discussed in their proper place, the act of turning on a burner-tap causes some acetylene to be produced, and the act of turning it off brings the reaction to an end, thus obviating the necessity for storage. That, at any rate, is the logical definition of the two fundamentally different kinds of generator: in automatic apparatus the decomposition of the carbide is periodically interrupted in such fashion as more or less accurately to synchronise with the consumption of gas; in the non-automatic variety decomposition proceeds without a break until the carbide vessels are empty. Unfortunately a somewhat different interpretation of these two words has found frequent acceptance, a generator being denominated non-automatic or automatic according as the holder attached to it is or is not large enough to store the whole of the acetylene which the charge of carbide is capable of producing if it is decomposed all at once. Apart from the fact that a holder, though desirable, is not an absolutely indispensable part of an acetylene plant, the definition just quoted was sufficiently free from objection in the earliest days of the industry; but now efficient commercial generators are to be met with which become either automatic or non-automatic according to the manner of working them, while some would be termed non-automatic which comprise mechanism of a conspicuously self- acting kind. AUTOMATIC AND NON-AUTOMATIC GENERATORS.--Before proceeding to a detailed description of the various devices which may be adopted to render an acetylene generator automatic in action, the relative advantages of automatic and non-automatic apparatus, irrespective of type, from the consumer's point of view may be discussed. The fundamental idea underlying the employment of a non-automatic generator is that the whole of the calcium carbide put into the apparatus shall be decomposed into acetylene as soon after the charge is inserted as is natural in the circumstances; so that after a very brief interval of time the generating chambers shall contain nothing but spent lime and water, and the holder be as full of gas as is ever desirable. In an automatic apparatus, the fundamental idea is that the generating chamber, or one at least of several generating chambers, shall always contain a considerable quantity of undecomposed carbide, and some receptacle always contain a store of water ready to attack that carbide, so that whenever a demand for gas shall arise everything may be ready to meet it. Inasmuch as acetylene is an inflammable gas, it possesses all the properties characteristic of inflammable gases in general; one of which is that it is always liable to take fire in presence of a spark or naked light, and another of which is that it is always liable to become highly explosive in presence of a naked light or spark if, accidentally or otherwise, it becomes mixed with more than a certain proportion of air. On the contrary, in the complete absence of liquid or vaporised water, calcium carbide is almost as inert a body as it is possible to imagine: for it will not take fire, and cannot in any circumstances be made to explode. Hence it may be urged that a non-automatic generator, with its holder always containing a large volume of the actually inflammable and potentially explosive acetylene, must invariably be more dangerous than an automatic apparatus which has less or practically no ready-made gas in it, and which simply contains water in one chamber and unaltered calcium carbide in another. But when the generating vessels and the holder of a non-automatic apparatus are properly designed and constructed, the gas in the latter is acetylene practically free from air, and therefore while being, as acetylene inevitably is, inflammable, is devoid of explosive properties, always assuming, as must be the case in a water-sealed holder, that the temperature of the gas is below 780° C.; and also assuming, as must always be the case in good plant, that the pressure under which the gas is stored remains less than two atmospheres absolute. It is perfectly true that calcium carbide is non-inflammable and non-explosive, that it is absolutely inert and incapable of change; but so comprehensive an assertion only applies to carbide in its original drum, or in some impervious vessel to which moisture and water have no access. Until it is exhausted, an automatic acetylene generator contains carbide in one place and water in another, dependence being put upon some mechanical arrangement to prevent the two substances coming into contact prematurely. Many of the devices adopted by builders of acetylene apparatus for keeping the carbide and water separate, and for mixing them in the requisite quantities when the proper time arrives, are as trustworthy, perhaps, as it is possible for any automatic gear to be; but some are objectionably complicated, and a few are positively inefficient. There are two difficulties which the designer of automatic mechanism has to contend with, and it is doubtful whether he always makes a sufficient allowance for them. The first is that not only must calcium carbide and liquid water be kept out of premature contact, but that moisture, or vapour of water, must not be allowed to reach the carbide; or alternatively, that if water vapour reaches the carbide too soon, the undesired reaction shall not determine overheating, and the liberated gas be not wasted or permitted to become a source of danger. The second difficulty encountered by the designer of automata is so to construct his apparatus that it shall behave well when attended to by completely unskilled labour, that it shall withstand gross neglect and resist positive ill-treatment or mismanagement. If the automatic principle is adopted in any part of an acetylene apparatus it must be adopted throughout, so that as far as possible--and with due knowledge and skill it is completely possible--nothing shall be left dependent upon the memory and common sense of the gasmaker. For instance, it must not be necessary to shut a certain tap, or to manipulate several cocks before opening the carbide vessel to recharge it; it must not be possible for gas to escape backwards out of the holder; and either the carbide-feed gear or the water-supply mechanism (as the case may be) must be automatically locked by the mere act of taking the cover off the carbide store, or of opening the sludge-cock at the bottom. It would be an advantage, even, if the purifiers and other subsidiary items of the plant were treated similarly, arranging them in such fashion that gas should be automatically prevented from escaping out of the rest of the apparatus when any lid was removed. In fact, the general notion of interlocking, which has proved so successful in railway signal-cabins and in carburetted water gas-plant for the prevention of accidents duo to carelessness or overnight, might be copied in principle throughout an acetylene installation whenever the automatic system is employed. It is no part of the present argument, to allege that automatic generators are, and must always be, inherently dangerous. Automatic devices of a suitable kind may be found in plenty which are remarkably simple and highly trustworthy; but it would be too bold a statement to say that any such arrangement is incapable of failure, especially when put into the hands of a person untrained in the superintendence of machinery. The more reliable a piece of automatic mechanism proves itself to be, the more likely is it to give trouble and inconvenience and utterly to destroy confidence when it does break down; because the better it has behaved in the past, and the longer it has lasted without requiring adjustment, the less likely is it that the attendant will be at hand when failure occurs. By suitable design and by an intelligent employment of safety-valves and blow-off pipes (which will be discussed in their proper place) it is quite easy to avoid the faintest possibility of danger arising from an increase of pressure or an improper accumulation of gas inside the plant or inside the building containing the plant; but every time such a safety-valve or blow-off pipe comes into action a waste of gas occurs, which means a sacrifice of economy, and shows that the generator is not working as it should. As glass is a fragile and brittle substance, and as it is not capable of bearing large, rapid, and oft-repeated alterations of temperature in perfect safety, it is not a suitable material for the construction of acetylene apparatus or of portions thereof. Hence it follows that a generator must be built of some non-transparent material which prevents the interior being visible when the apparatus is at work. Although it is comparatively easy, by the aid of a lamp placed outside the generator- shed in such a position as to throw its beams of light through a window upon the plant inside, to charge a generator after dark; and although it is possible, without such assistance, by methodical habits and a systematic arrangement of utensils inside the building to charge a generator even in perfect darkness, such an operation is to be deprecated, for it is apt to lead to mistakes, it prevents any slight derangement in the installation from being instantly noticed, and it offers a temptation to the attendant to break rules and to take a naked light with him. On all those grounds, therefore, it is highly desirable that every manipulation connected with a generator shall be effected during the daytime, and that the apparatus-house shall be locked up before nightfall. But owing to the irregular habits engendered by modern life it is often difficult to know, during any given day, how much gas will be required in the ensuing evening; and it therefore becomes necessary always to have, as ready-made acetylene, or as carbide in a proper position for instant decomposition, a patent or latent store of gas more than sufficient in quantity to meet all possible requirements. Now, as already stated, a non-automatic apparatus has its store of material in the form of gas in a holder; and since this is preferably constructed on the rising or telescopic principle, a mere inspection of the height of the bell--on which, if preferred, a scale indicating its contents in cubic feet or in burner-hours may be marked--suffices to show how near the plant is to the point of exhaustion. In many types of automatic apparatus the amount of carbide remaining undecomposed at any moment is quite unknown, or at best can only be deduced by a tedious and inexact calculation; although in some generators, where the store of carbide is subdivided into small quantities, or placed in several different receptacles, an inspection of certain levers or indicators gives an approximate idea as to the capacity of the apparatus for further gas production. In any case the position of a rising holder is the most obvious sign of the degree of exhaustion of a generator; and therefore, to render absolutely impossible a failure of the light during an evening, a non-automatic generator fitted with a rising holder is best. Since calcium carbide is a solid body having a specific gravity of 2.2, water being unity, and since 1 cubic foot of water weighs 62.4 lb., in round numbers 137 lb. of _compact_ carbide only occupy 1 cubic foot of space. Again, since acetylene is a gas having a specific gravity of 0.91, air being unity, and since the specific gravity of air, water being unity, is 0.0013, the specific gravity of acetylene, water being unity, is roughly O.00116. Hence 1 cubic foot of acetylene weighs roughly 0.07 lb. Furthermore, since 1 lb. of good carbide evolves 5 cubic feet of gas on decomposition with water, acetylene stored at atmospheric pressure occupies roundly 680 times as much space as the carbide from which it has been evolved. This figure by no means represents the actual state of affairs in a generator, because, as was explained in the previous chapter, a carbide vessel cannot be filled completely with solid; and, indeed, were it so "filled," in ordinary language, much of its space would be still occupied with air. Nevertheless it is incontrovertible that an acetylene plant calculated to supply so many burners for so long a period of time must be very much larger if it is constructed on the non-automatic principle, when the carbide is decomposed all at once, than if the automatic system is adopted, when the solid remains unattacked until a corresponding quantity of gas is required for combustion. Clearly it is the storage part of a non-automatic plant alone which must be so much larger; the actual decomposing chambers may be of the same size or even smaller, according to the system of generation to which the apparatus belongs. In practice this extra size of the non-automatic plant causes it to exhibit two disadvantages in comparison with automatic apparatus, disadvantages which are less serious than they appear, or than they may easily be represented to be. In the first place, the non- automatic generator requires more space for its erection. If acetylene were an illuminating agent suitable for adoption by dwellers in city or suburb, where the back premises and open-air part of the messuage are reduced to minute proportions or are even non-existent, this objection might well be fatal. But acetylene is for the inhabitant of a country village or the occupier of an isolated country house; and he has usually plenty of space behind his residence which he can readily spare. In the second place, the extra size of the non-automatic apparatus makes it more expensive to construct and more costly to instal. It is more cosily to construct and purchase because of its holder, which must be well built on a firm foundation and accurately balanced; it is more costly to instal because a situation must be found for the erection of the holder, and the apparatus-house may have to be made large enough to contain the holder as well as the generator itself. As regards the last point, it may be said at once that there is no necessity to place the holder under cover: it may stand out of doors, as coal-gas holders do in England, for the seal of the tank can easily be rendered frost-proof, and the gas itself is not affected by changes of atmospheric temperature beyond altering somewhat in volume. In respect of the other objections, it must be remembered that the extra expense is one of capital outlay alone, and therefore only increases the cost of the light by an inappreciable amount, representing interest and depreciation charges on the additional capital expenditure. The increased cost of a year's lighting due to these charges will amount to only 10 or 15 per cent, on the additional capital sunk. The extra capital sunk does not in any way increase the maintenance charges; and if, by having a large holder, additional security and trustworthiness are obtained, or if the holder leads to a definite, albeit illusive, sense of extra security and trustworthiness, the additional expenditure may well be permissible or even advantageous. The argument is sometimes advanced that inasmuch as for the same, or a smaller, capital outlay as is required to instal a non-automatic apparatus large enough to supply at one charging the maximum amount of light and heat that can ever be needed on the longest winter's night, an automatic plant adequate to make gas for two or three evenings can be laid down, the latter must be preferable, because the attendant, in the latter case, will only need to enter the generator-house two or three times a week. Such an argument is defective because it ignores the influence of habit upon the human being. A watch which must be wound every day, or a clock which must be wound every week, on a certain day of the week, is seldom permitted to run down; but a watch requiring to be re-wound every other day, or a fourteen-day clock (used as such), would rarely be kept going. Similarly, an acetylene generator might be charged once a week or once a day without likelihood of being forgotten; but the operation of charging at irregular intervals would certainly prove a nuisance. With a non-automatic apparatus containing all its gas in the holder, the attendant would note the position of the bell each morning, and would introduce sufficient carbide to fill the holder full, or partly full, as the case might be; with an automatic apparatus he would be tempted to trust that the carbide holders still contained sufficient material to last another night. The automatic system of generating acetylene has undoubtedly one advantage in those climates where frost tends to occur frequently, but only to prevail for a short period. As the apparatus is in operation during the evening hours, the heat evolved will, or can be made to, suffice to protect the apparatus from freezing until the danger has passed; whereas if the gas is generated of a morning in a non-automatic apparatus the temperature of the plant may fall to that of the atmosphere before evening, and some portion may freeze unless special precautions are taken to protect it. It was shown in Chapter II that overheating is one of the chief troubles to be guarded against in acetylene generators, and that the temperature attained is a function of the speed at which generation proceeds. Seeing that in an automatic apparatus the rate of decomposition depends on the rate at which gas is being burnt, while in a non-automatic generator it is, or may be, under no control, the critic may urge that the reaction must take place more slowly and regularly, and the maximum temperature therefore be lower, when the plant works automatically. This may be true if the non-automatic generator is unskilfully designed or improperly manipulated; but it is quite feasible to arrange an apparatus, especially one of the carbide-to-water or of the flooded-compartment type, in such fashion that overheating to an objectionable extent is rendered wholly impossible. In a non-automatic apparatus the holder is nothing but a holder and may be placed wherever convenient, even at a distance from the generating plant; in an automatic apparatus the holder, or a small similarly constructed holder placed before the main storage vessel, has to act as a water-supply governor, as the releasing gear for certain carbide-food mechanism, or indeed as the motive power of such mechanism; and accordingly it must be close to the water or carbide store, and more or less intimately connected by means of levers, or the like, with the receptacle in which decomposition occurs. Sometimes the holder surrounds, or is otherwise an integral part of, the decomposing chamber, the whole apparatus being made self-contained or a single structure with the object of gaining compactness. But it is evident that such methods of construction render additionally awkward, or even hazardous, any repair or petty operation to the generating portion of the plant; while the more completely the holder is isolated from the decomposing vessels the more easily can they be cleaned, recharged, or mended, without blowing off the stored gas and without interfering with the action of any burners that may be alight at the time. Owing to the ingenuity of inventors, and the experience they have acquired in the construction of automatic acetylene apparatus during the years that the gas has been in actual employment, it is going too far boldly to assert that non-automatic generators are invariably to be preferred before their rivals. Still in view of the nature of the labour which is likely to be bestowed on any domestic plant, of the difficulty in having repairs or adjustments done quickly in outlying country districts, and of the inconvenience, if not risk, attending upon any failure of the apparatus, the greater capital outlay, and the larger space required by non-automatic generators are in most instances less important than the economy in space and prime cost characteristic of automatic machines when the defects of each are weighed fairly in the balance. Indeed, prolonged experience tends to show that a selection between non-automatic and automatic apparatus may frequently be made on the basis of capacity. A small plant is undoubtedly much more convenient if automatic; a very large plant, such as that intended for a public supply, is certainly better if non-automatic, but between these two extremes choice may be exercised according to local conditions. CONTROL OF THE CHEMICAL REACTION.--Coming now to study the principles underlying the construction of an acetylene generator more closely it will be seen that as acetylene is produced by bringing calcium carbide into contact with water, the chemical reaction may be started either by adding the carbide to the water, or by adding the water to the carbide. Similarly, at least from the theoretical aspect, the reaction, may be caused to stop by ceasing to add carbide to water, or by ceasing to add water to carbide. Apparently if water is added by degrees to carbide, until the carbide is exhausted, the carbide must always be in excess; and manifestly, if carbide is added in small portions to water, the water must always be in excess, which, as was argued in Chapter II., is emphatically the more desirable position of affairs. But it in quite simple to have carbide present in large excess of the water introduced when the whole generator is contemplated, and yet to have the water always in chemical excess in the desired manner; because to realise the advantages of having water in excess, it is only necessary to subdivide the total charge of carbide into a number of separate charges which are each so small that more than sufficient water to decompose and flood one of them is permitted to enter every time the feed mechanism comes into play, or (in a non-automatic apparatus) every time the water-cock is opened; so arranging the charges that each one is protected from the water till its predecessor, or its predecessor, have been wholly decomposed. Thus it is possible to regard either the carbide or the water as the substance which has to be brought into contact with the other in specified quantity. It is perhaps permissible to repeat that in the construction of an automatic generator there is no advantage to be gained from regulating the supply of both carbide and water, because just as the mutual decomposition will begin immediately any quantity of the one meets any quantity of the other, so the reaction will cease (except in one case owing to "after-generation") directly the whole of that material which is not in chemical excess has been consumed-quite independently of the amount of the other material left unattacked. Being a liquid, and possessing as such no definite shape or form of its own irrespective of the vessel in which it is held, water is by far the more convenient of the two substances to move about or to deliver in predetermined volume to the decomposing chamber. A supply of water can be started instantaneously or cut oil as promptly by the movement of a cock or valve of the usual description; or it may be allowed to run down a depending pipe in obedience to the law of gravitation, and stopped from running down such a pipe by opposing to its passage a gas pressure superior to that gravitational force. In any one of several obvious ways the supply of water to a mass of carbide may be controlled with absolute certainty, and therefore it should apparently follow that the make of acetylene should be under perfect control by controlling the water current. On the other hand, unless made up into balls or cartridges of some symmetrical form, calcium carbide exists in angular masses of highly irregular shape and size. Its lumps alter in shape and size directly liquid water or moisture reaches them; a loose more or loss gritty powder, or a damp cohesive mud, being produced which is well calculated to choke any narrow aperture or to jam any moving valve. It is more difficult, therefore, by mechanical agency to add a supply of carbide to a mass of water than to introduce a supply of water to a stationary mass of carbide; and far more difficult still to bring the supply of carbide under perfect control with the certainty that the movement shall begin and stop immediately the proper time arrives. But assuming the mechanical difficulties to be satisfactorily overcome, the plan of adding carbide to a stationary mass of water has several chemical advantages, first, because, however the generator be constructed, water will be in excess throughout the whole time of gas production; and secondly, because the evolution of acetylene will actually cease completely at the moment when the supply of carbide is interrupted. There is, however, one particular type of generator in which as a matter of fact the carbide is the moving constituent, viz., the "dipping" apparatus (cf. _infra_), to which these remarks do not apply; but this machine, as will be seen directly, is, illogically perhaps, but for certain good reasons, classed among the water-to-carbide apparatus. All the mechanical advantages are in favour, as just indicated, of making water the moving substance; and accordingly, when classified in the present manner, a great majority of the generators now on the markets are termed water-to-carbide apparatus. Their disadvantages are twofold, though these may be avoided or circumvented: in all types save one the carbide is in excess at the immediate place and time of decomposition; and in all types without exception the carbide in the whole of the generator is in excess, so that the phenomenon of "after- generation" occurs with more or less severity. As explained in the last chapter, after-generation is the secondary production of acetylene which takes place more or less slowly after the primary reaction is finished, proceeding either between calcium hydroxide, merely damp lime, or damp gas and calcium carbide, with an evolution of more acetylene. As it is possible, and indeed usual, to fit a holder of some capacity even to an automatic generator, the simple fact that more acetylene is liberated after the main reaction is over does not matter, for the gas can be safely stored without waste and entirely without trouble or danger. The real objection to after-generation is the difficulty of controlling the temperature and of dissipating the heat with which the reaction is accompanied. It will be evident that the balance of advantage, weighing mechanical simplicity against chemical superiority, is somewhat even between carbide-to-water and water-to-carbide generators of the proper type; but the balance inclines towards the former distinctly in the ease of non-automatic apparatus, and points rather to the latter when automatism is desired. In the early days of the industry it would have been impossible to speak so favourably of automatic carbide-to-water generators, for they were at first constructed with absurdly complicated and unreliable mechanism; but now various carbide-feed gears have been devised which seem to be trustworthy even when carbide not in cartridge form is employed. NON-AUTOMATIC CARBIDE-TO-WATER GENERATORS.--There is little to be said in the present place about the principles underlying the construction of non-automatic generators. Such apparatus may either be of the carbide-to- water or the water-to-carbide type. In the former, lumps of carbide are dropped by hand down a vertical or sloping pipe or shoot, which opens at its lower end below the water-level of the generating chamber, and which is fitted below its mouth with a deflector to prevent the carbide from lodging immediately underneath that mouth. The carbide falls through the water which stands in the shoot itself almost instantaneously, but during its momentary descent a small quantity of gas is evolved, which produces an unpleasant odour unless a ventilating hood is fixed above the upper end of the tube. As the ratio of cubical contents to superficial area of a lump is greater as the lump itself is larger, and as only the outer surface of the lump can be attacked by the water in the shoot during its descent, carbide for a hand-fed carbide-to-water generator should be in fairly large masses--granulated material being wholly unsuitable--and this quite apart from the fact that large carbide is superior to small in gas-making capacity, inasmuch as it has not suffered the inevitable slight deterioration while being crushed and graded to size. If carbide is dropped too rapidly into such a generator which is not provided with a false bottom or grid for the lumps to rest upon, the solid is apt to descend among a mass of thick lime sludge produced at a former operation, which lies at the bottom of the decomposing chamber; and here it may be protected from the cooling action of fresh water to such an extent that its surface is baked or coated with a hard layer of lime, while overheating to a degree far exceeding the boiling-point of water may occur locally. When, however, it falls upon a grid placed some distance above the bottom of the water vessel, the various convection currents set up as parts of the liquid become warm, and the mechanical agitations produced by the upward current of gas rinse the spent lime from the carbide, and entirely prevent overheating, unless the lumps are excessively large in size. If the carbide charged into a hand-fed generator is in very large lumps there is always a possibility that overheating may occur in the centre of the masses, due to the baking of the exterior, even if the generator is fitted with a reaction grid. Manifestly, when carbide in lumps of reasonable size is dropped into excess of water which is not merely a thick viscid cream of lime, the temperature cannot possibly exceed the boiling-point--_i.e._, 100° C.--provided always the natural convection currents of the water are properly made use of. The defect which is, or rather which may be, characteristic of a hand-fed carbide-to-water generator is a deficiency of gas yield due to solubility. At atmospheric temperatures and pressure 10 volumes of water dissolve 11 volumes of acetylene, and were the whole of the water in a large generator run to waste often, a sensible loss of gas would ensue. If the carbide falls nearly to the bottom of the water column, the rising gas is forced to bubble through practically the whole of the liquid, so that every opportunity is given it to dissolve in the manner indicated till the liquid is completely saturated. The loss, however, is not nearly so serious as is sometimes alleged, because (1) the water becomes heated and so loses much of its solvent power; and (2) the generator is worked intermittently, with sufficiently long intervals to allow the spent lime to settle into a thick cream, and only that thick cream is run off, which represents but a small proportion of the total water present. Moreover, a hand-fed carbide-to-water generator will work satisfactorily with only half a gallon [Footnote: The United States National Board of Fire Underwriters stipulates for the presence of 1 (American) gallon of water for every 1 lb. of carbide before such an apparatus is "permitted." This quantity of liquid might retain nearly 4 per cent. of the total acetylene evolved. Even this is an exaggeration; for neither her, nor in the corresponding figure given in the text, is any allowance made for the diminution in solvent power of the water as it becomes heated by the reaction.] of liquid present for every 1 lb. of carbide decomposed, and were all this water run off and a fresh quantity admitted before each fresh introduction of carbide, the loss of acetylene by dissolution could not exceed 2 per cent. of the total make, assuming the carbide to be capable of yielding 5 cubic feet of gas per lb. Admitting, however, that some loss of gas does occur in this manner, the defect is partly, if not wholly, neutralised by the concomitant advantages of the system: (1) granted that the generator is efficiently constructed, decomposition of the carbide is absolutely complete, so that no loss of gas occurs in this fashion; (2) the gas is evolved at a low temperature, so that it is unaccompanied, by products of polymerisation, which may block the leading pipes and must reduce the illuminating power; (3) the acetylene is not mixed with air (as always happens at the first charging of a water-to- carbide apparatus), which also lowers the illuminating power; and (4) the gas is freed from two of its three chief impurities, viz., ammonia and sulphuretted hydrogen, in the generating chamber itself. To prevent the loss of acetylene by dissolution, carbide-to-water generators are occasionally fitted with a reaction grid placed only just below the water-level, so that the acetylene has no more than 1 inch or so of liquid to bubble through. The principle is wrong, because hot water being lighter than cold, the upper layers may be raised to the boiling-point, and even converted into steam, while the bulk of the liquid still remains cold; and if the water actually surrounding the carbide is changed into vapour, nearly all control over the temperature attending the reaction is lost. The hand-fed carbide-to-water generator is very simple and, as already indicated, has proved itself perhaps the best type of all for the construction of very large installations; but the very simplicity of the generator has caused it more than once to be built in a manner that has not given entire satisfaction. As shown at L in Fig. 6, p. 84, the generator essentially consists of a closed cylindrical vessel communicating at its top with a separate rising holder. At one side as drawn, or disposed concentrically if so preferred, is an open-mouthed pipe or shoot (American "shute") having its lower open extremity below the water-level. Into this shoot are dropped by hand or shovel lumps of carbide, which fall into the water and there suffer decomposition. As the bottom of the shoot is covered with water, which, owing to the small effective gas pressure in the generator given by the holder, stands a few inches higher in the shoot than in the generator, gas cannot escape from the shoot; because before it could do so the water in the generator would have to fall below the level of the point _a_, being either driven out through the shoot or otherwise. Since the point _b_ of the shoot extends further into the generator than _a_, the carbide drops centrally, and as the bubbles of gas rise vertically, they have no opportunity of ascending into the shoot. In practice, the generator is fitted with a conical bottom for the collection of the lime sludge and with a cock or other aperture at the apex of the cone for the removal of the waste product. As it is not desirable that the carbide should be allowed to fall directly from the shoot into the thicker portion of the sludge within the conical part of the generator, one or more grids is usually placed in the apparatus as shown by the dotted lines in the sketch. It does not seem that there is any particular reason for the employment of more than one grid, provided the size of the carbide decomposed is suited to the generator, and provided the mesh of the grid is suited to the size of the carbide. A great improvement, however, is made if the grid is carried on a horizontal spindle in such a way that it can be rocked periodically in order to assist in freeing the lumps of carbide from the adhering particles of lime. As an alternative to the movable grid, or even as an adjunct thereto, an agitator scraping the conical sides of the generator may be fitted which also assists in ensuring a reasonably complete absence of undecomposed carbide from the sludge drawn off at intervals. A further point deserves attention. If constructed in the ideal manner shown in Fig. 6 removal of some of the sludge in the generator would cause the level of the liquid to descend and, by carelessness, the level might fall below the point _a_ at the base of the shoot. In these circumstances, if gas were unable to return from the holder, a pressure below that of the atmosphere would be established in the gas space of the generator and air would be drawn in through the shoot. This air might well prove a source of danger when generation was started again. Any one of three plans may be adopted to prevent the introduction of air. A free path may be left on the gas-main passing from the generator to the holder so that gas may be free to return and so to maintain the usual positive pressure in the decomposing vessel; the sludge may be withdrawn into some vessel so small in capacity that the shoot cannot accidentally become unsealed; or the waterspace of the generator may be connected with a water-tank containing a ball-valve attached to a constant service of water be that liquid runs in as quickly as sludge is removed, and the level remains always at the same height. The first plan is only a palliative and has two defects. In the first place, the omission of any non-return valve between, the generator and the next item in the train of apparatus is objectionable of itself; in the second place, should a very careless attendant withdraw too much liquid, the shoot might become unsealed and the whole contents of the holder be passed into the air of the building containing the apparatus through the open mouth of the shoot. The second plan is perfectly sound, but has the practical defect of increasing the labour of cleaning the generator. The third plan is obviously the best. It can indeed be adopted where no real constant service of water is at hand by connecting the generator to a water reservoir of relatively large size and by making the latter of comparatively large transverse area, in proportion to its depth; so that the escape of even a largo volume of water from the reservoir may not involve a large reduction in the level at which it stands there. The dust that always clings to lumps of carbide naturally decomposes with extreme rapidity when the material is thrown into the shoot of a carbide- to-water generator, and the sudden evolution of gas so produced has on more than one occasion seriously alarmed the attendant on the plant. Moreover, to a trifling extent the actual superficial layers of the carbide suffer attack before the lumps reach the true interior of the generator, and a small loss of gas thereby occurs through the open mouth of the shoot. To remove these objections to the hand-fed generator it has become a common practice in large installations to cause the lower end of the shoot to dip under the level of some oil contained in an appropriate receptacle, the carbide falling into a basket carried upon a horizontal spindle. The basket and its support are so arranged that when a suitable charge of carbide has been dropped into it, a partial rotation of an external hand-wheel lifts the basket and carbide out of the oil into an air-tight portion of the generator where the surplus oil can drain away from the lumps. A further rotation of the hand-wheel then tips the basket over a partition inside the apparatus, allowing the carbide to fall into the actual decomposing chamber. This method of using oil has the advantage of making the evolution of acetylene on a large scale appear to proceed more quietly than usual, and also of removing the dust from the carbide before it reaches the water of the generator. The oil itself obviously does not enter the decomposing chamber to any appreciable extent and therefore does not contaminate the final sludge. The whole process accordingly lies to be favourably distinguished from those other methods of employing oil in generators or in the treatment of carbide which are referred to elsewhere in this book. NON-AUTOMATIC WATER-TO-CARBIDE GENERATORS.--The only principle underlying the satisfactory design of a non-automatic water-to-carbide generator is to ensure the presence of water in excess at the spot where decomposition is taking place. This may be effected by employing what is known as the "flooded-compartment" system of construction, _i.e._, by subdividing the total carbide charge into numerous compartments arranged either vertically or horizontally, and admitting the water in interrupted quantities, each more than sufficient thoroughly to decompose and saturate the contents of one compartment, rather than in a slow, steady stream. It would be quite easy to manage this without adopting any mechanism of a moving kind, for the water might be stored in a tank kept full by means of a ball-valve, and admitted to an intermediate reservoir in a slow, continuous current, the reservoir being fitted with an inverted syphon, on the "Tantalus-cup" principle, so that it should first fill itself up, and then suddenly empty into the pipe leading to the carbide container. Without this refinement, however, a water-to-carbide generator, with subdivided charge, behaves satisfactorily as long as each separate charge of carbide is so small that the heat evolved on its decomposition can be conducted away from the solid through the water- jacketed walls of the vessel, or as the latent heat of steam, with sufficient rapidity. Still it must be remembered that a water-to-carbide generator, with subdivided charge, does not belong to the flooded- compartment type if the water runs in slowly and continuously: it is then simply a "contact" apparatus, and may or may not exhibit overheating, as well as the inevitable after-generation. All generators of the water-to- carbide type, too, must yield a gas containing some air in the earlier portions of their make, because the carbide containers can only be filled one-third or one-half full of solid. Although the proportion of air so passed into the holder may be, and usually is, far too small in amount to render the gas explosive or dangerous in the least degree, it may well be sufficient to reduce the illuminating power appreciably until it is swept out of the service by the purer gas subsequently generated. Moreover, all water-to-carbide generators are liable, as just mentioned, to produce sufficient overheating to lower the illuminating power of the gas whenever they are wilfully driven too fast, or when they are reputed by their makers to be of a higher productive capacity than they actually should be; and all water-to-carbide generators, excepting those where the carbide is thoroughly soaked in water at some period of their operation, are liable to waste gas by imperfect decomposition. DEVICES TO SECURE AUTOMATIC ACTION,--The devices which are commonly employed to render a generator automatic in action, that is to say, to control the supply of one of the two substances required in the intermittent evolution of gas, may be divided into two broad classes: (A) those dependent upon the position of a rising-holder bell, and (B) those dependent upon the gas pressure inside the apparatus. As the bell of a rising holder descends in proportion as its gaseous contents are exhausted, it may (A^1) be fitted with some laterally projecting pin which, arrived at a certain position, actuates a series of rods or levers, and either opens a cock on the water-supply pipe or releases a mechanical carbide-feed gear, the said cock being closed again or the feed-gear thrown out of action when the pin, rising with the bell, once more passes a certain position, this time in its upward path. Secondly (A^2), the bell may be made to carry a perforated receptacle containing carbide, which is dipped into the water of the holder tank each time the bell falls, and is lifted out of the water when it rises again. Thirdly (A^3), by fitting inside the upper part of the bell a false interior, conical in shape, the descent of the bell may cause the level of the water in the holder tank to rise until it is above some lateral aperture through which the liquid may escape into a carbide container placed elsewhere. These three methods are represented in the annexed diagram (Fig. 1). In Al the water-levels in the tank and bell remain always at _l_, being higher in the tank than in the bell by a distance corresponding with the pressure produced by the bell itself. As the bell falls a pin _X_ moves the lever attached to the cock on the water- pipe, and starts, or shuts off, a current passing from a store-tank or reservoir to a decomposing vessel full of carbide. It is also possible to make _X_ work some releasing gear which permits carbide to fall into water--details of this arrangement are given later on. In A^1 the water in the tank serves as a holder seal only, a separate quantity being employed for the purposes of the chemical reaction. This arrangement has the advantage that the holder water lasts indefinitely, except for evaporation in hot weather, and therefore it may be prevented from freezing by dissolving in it some suitable saline body, or by mixing with it some suitable liquid which lowers its point of solidification. It will be observed, too, that in A^1 the pin _X_, which derives its motive power from the surplus weight of the falling bell, has always precisely the same amount of work to do, viz., to overcome the friction of the plug of the water-cock in its barrel. Hence at all times the pressure obtaining in the service-pipe is uniform, except for a slight jerk momentarily given each time the cock is opened or closed. When _X_ actuates a carbide-feed arrangement, the work it does may or may not vary on different occasions, as will appear hereafter. In A^2 the bell itself carries a perforated basket of carbide, which is submerged in the water when the bell falls, and lifted out again when it rises. As the carbide is thus wetted from below, the lower portion of the mass soon becomes a layer of damp slaked lime, for although the basket is raised completely above the water-level, much liquid adheres to the spent carbide by capillary attraction. Hence, even when the basket is out of the water, acetylene is being produced, and it is produced in circumstances which prevent any control over the temperature attained. The water clinging to the lower part of the basket is vaporised by the hot, half-spent carbide, and the steam attacks the upper part, so that polymerisation of the gas and baking of the carbide are inevitable. In the second place, the pressure in the service-pipe attached to A^2 depends as before upon the net weight of the holder bell; but here that net weight is made up of the weight of the bell itself, that of the basket, and that of the carbide it contains. Since the carbide is being gradually converted into damp slaked lime, it increases in weight to an indeterminate extent as the generator in exhausted; but since, on the other hand, some lime may be washed out of the basket each time it is submerged, and some of the smaller fragments of carbide may fall through the perforations, the basket tends to decrease in weight as the generator is exhausted. Thus it happens in A^2 that the combined weight of bell plus basket plus contents is wholly indefinite, and the pressure in the service becomes so irregular that a separate governor must be added to the installation before the burners can be expected to behave properly. In the third place, the water in the tank serves both for generation and for decomposition, and this involves the employment of some arrangement to keep its level fairly constant lest the bell should become unsealed, while protection from frost by saline or liquid additions is impossible. A^2 is known popularly as a "dipping" generator, and it will be seen to be defective mechanically and bad chemically. In both A^1 and A^2 the bell is constructed of thin sheet- metal, and it is cylindrical in shape; the mass of metal in it is therefore negligible in comparison with the mass of water in the tank, and so the level of the liquid is sensibly the same whether the bell be high or low. In A^3 the interior of the bell is fitted with a circular plate which cuts off its upper corners and leaves a circumferential space _S_ triangular in vertical section. This space is always full of air, or air and water, and has to be deducted from the available storage capacity of the bell. Supposing the bell transparent, and viewing it from above, its effective clear or internal diameter will be observed to be smaller towards the top than near the bottom; or since the space _S_ is closed both against the water and against the gas, the walls of the bell may be said to be thicker near its top. Thus it happens that as the bell descends into the water past the lower angle of _S_, it begins to require more space for itself in the tank, and so it displaces the water until the levels rise. When high, as shown in the sketch marked A^3(a), the water-level is at _l_, below the mouth of a pipe _P_; but when low, as in A^3(b), the water is raised to the point _l'_, which is above _P_. Water therefore flows into _P_, whence it reaches the carbide in an attached decomposing chamber. Here also the water in the tank is used for decomposition as well as for sealing purposes, and its normal level must be maintained exactly at _l_, lest the mouth of _P_ should not be covered whenever the bell falls. [Illustration: FIG. 1.--TYPICAL METHODS OF AUTOMATIC GENERATION CONTROLLED BY BELL GASHOLDER.] The devices employed to render a generator automatic which depend upon pressure (B) are of three main varieties: (B^1) the water-level in the decomposing chamber may be depressed by the pressure therein until its surface falls below a stationary mass of carbide; (B^2) the level in a water-store tank may be depressed until it falls below the mouth of a pipe leading to the carbide vessel; (B^3) the current of water passing down a pipe to the decomposing chamber may be interrupted by the action of a pressure superior to the force of gravitation. These arrangements are indicated roughly in Fig. 2. In B^1, D is a hollow cylinder closed at all points except at the cock G and the hole E, which are always below the level of the water in the annulus F, the latter being open to the air at its top. D is rigidly fastened to the outer vessel F so that it cannot move vertically, and the carbide cage is rigidly fastened to D. Normally the water-levels are at _l_, and the liquid has access to the carbide through perforations in the basket. Acetylene is thus produced; but if G is shut, the gas is unable to escape, and so it presses downwards upon the water until the liquid falls in D to the dotted line _l"_, rising in F to the dotted line _l'_. The carbide is then out of water, and except for after-generation, evolution of gas ceases. On opening G more or less fully, the water more or less quickly reaches its original position at _l_, and acetylene is again produced. Manifestly this arrangement is identical with that of A^2 as regards the periodical immersion of the carbide holder in the liquid; but it is even worse than the former mechanically because there is no rising holder in B^1, and the pressure in the service is never constant. B^2 represents the water store of an unshown generator which works by pressure. It consists of a vessel divided vertically by means of a partition having a submerged hole N. One-half, H, is cloned against the atmosphere, but communicates with the gas space of the generator through L; the other half, K, is open to the air. M is a pipe leading water to the carbide. When gas is being burnt as fast as, or faster than, it is being evolved, the pressure in the generator is small, the level of the water stands at _l_, and the mouth of M is below it. When the pressure rises by cessation of consumption, that pressure acts through L upon the water in H, driving it down in H and up in K till it takes the positions _l"_, and _l'_, the mouth of M being then above the surface. It should be observed that in the diagrams B^1 and B^3, the amount of pressure, and the consequent alteration in level, is grossly exaggerated to gain clearness; one inch or less in both cases may be sufficient to start or retard evolution of acetylene. Fig. B^3 is somewhat ideal, but indicates the principle of opposing gas pressure to a supply of water depending upon gravitation; a method often adopted in the construction of portable acetylene apparatus. The arrangement consists of an upper tank containing water open to the air, and a lower vessel holding carbide closed everywhere except at the pipe P, which leads to the burners, and at the pipe S, which introduces water from the store-tank. If the cock at T is closed, pressure begins to rise in the carbide holder until it is sufficient to counterbalance the weight of the column of water in the pipe S, when a further supply is prevented until the pressure sinks again. This idea is simply an application of the displacement-holder principle, and as such is defective (except for vehicular lamps) by reason of lack of uniformity in pressure. [Illustration: FIG. 2.--TYPICAL METHODS OF AUTOMATIC GENERATION CONTROLLED BY INTERNAL GAS PRESSURE.] DISPLACEMENT GASHOLDERS.--An excursion may here be made for the purpose of studying the action of a displacement holder, which in its most elementary form is shown at C. It consists of an upright vessel open at the top, and divided horizontally into two equal portions by a partition, through which a pipe descends to the bottom of the lower half. At the top of the closed lower compartment a tube is fixed, by means of which gas can be introduced below the partition. While the cock is open to the air, water is poured in at the open top till the lower compartment is completely full, and the level of the liquid is at _l_. If now, gas is driven in through the side tube, the water is forced downwards in the lower half, up through the depending pipe till it begins to fill the upper half of the holder, and finally the upper half is full of water and the lower half of gas an shown by the levels _l'_ and _l"_. But the force necessary to introduce gas into such an apparatus, which conversely is equal to the force with which the apparatus strives to expel its gaseous contents, measured in inches of water, is the distance at any moment between the levels _l'_ and _l"_; and as these are always varying, the effective pressure needed to fill the apparatus, or the effective pressure given by the apparatus, may range from zero to a few inches less than the total height of the whole holder. A displacement holder, accordingly, may be used either to store a varying quantity of gas, or to give a steady pressure just above or just below a certain desired figure; but it will not serve both purposes. If it is employed as a holder, it in useless as a governor or pressure regulator; if it is used as a pressure regulator, it can only hold a certain fixed volume of gas. The rising holder, which is shown at A^1 in Fig. 1 (neglecting the pin X, &c.) serves both purposes simultaneously; whether nearly full or nearly empty, it gives a constant pressure--a pressure solely dependent upon its effective weight, which may be increased by loading its crown or decreased by supporting it on counterpoises to any extent that may be required. As the bell of a rising holder moves, it must be provided with suitable guides to keep its path vertical; these guides being arranged symmetrically around its circumference and carried by the tank walls. A fixed control rod attached to the tank over which a tube fastened to the bell slides telescope-fashion is sometimes adopted; but such an arrangement is in many respects less admirable than the former. Two other devices intended to give automatic working, which are scarcely capable of classification among their peers, may be diagrammatically shown in Fig. 3. The first of these (D) depends upon the movements of a flexible diaphragm. A vessel (_a_) of any convenient size and shape is divided into two portions by a thin sheet of metal, leather, caoutchouc, or the like. At its centre the diaphragm is attached by some air-tight joint to the rod _c_, which, held in position by suitable guides, is free to move longitudinally in sympathy with the diaphragm, and is connected at its lower extremity with a water-supply cock or a carbide-feed gear. The tube _e_ opens at its base into the gas space of the generator, so that the pressure below the diaphragm in _a_ is the same as that elsewhere in the apparatus, while the pressure in _a_ above the diaphragm is that of the atmosphere. Being flexible and but slightly stretched, the diaphragm is normally depressed by the weight of _c_ until it occupies the position _b_; but if the pressure in the generator (_i.e._, in _e_) rises, it lifts the diaphragm to somewhat about the position _b'_--the extent of movement being, as usual, exaggerated in the sketch. The movement of the diaphragm is accompanied by a movement of the rod _c_, which can be employed in any desirable way. In E the bell of a rising holder of the ordinary typo is provided with a horizontal striker which, when the bell descends, presses against the top of a bag _g_ made of any flexible material, such as india-rubber, and previously filled with water. Liquid is thus ejected, and may be caused to act upon calcium carbide in some adjacent vessel. The sketch is given because such a method of obtaining an intermittent water-supply has at one time been seriously proposed; but it is clearly one which cannot be recommended. [Illustration: FIG. 3.--TYPICAL METHODS OF AUTOMATIC GENERATION CONTROLLED BY A FLEXIBLE DIAPHRAM OR BAG.] ACTION OF WATER-TO-CARBIDE GENERATORS.--Having by one or other of the means described obtained a supply of water intermittent in character, it remains to be considered how that supply may be made to approach the carbide in the generator. Actual acetylene apparatus are so various in kind, and merge from one type to another by such small differences, that it is somewhat difficult to classify them in a simple and intelligible fashion. However, it may be said that water-to-carbide generators, _i.e._, such as employ water as the moving material, may be divided into four categories: (F^1) water is allowed to fall as single drops or as a fine stream upon a mass of carbide--this being the "drip" generator; (F^2) a mass of water is made to rise round and then recede from a stationary vessel containing carbide--this being essentially identical in all respects save the mechanical one with the "dip" or "dipping" generator shown in A^2, Fig. 1; (F^3) a supply of water is permitted to rise round, or to flow upon, a stationary mass of carbide without ever receding from the position it has once assumed--this being the "contact" generator; and (F^4) a supply of water is admitted to a subdivided charge of carbide in such proportion that each quantity admitted is in chemical excess of the carbide it attacks. With the exception of F^2, which has already been illustrated as A^2 Fig. 1, or as B^1 in Fig. 2, these methods of decomposing carbide are represented in Figs. 4 and 5. It will be observed that whereas in both F^1 and F^3 the liberated acetylene passes off at the top of the apparatus, or rather from the top of the non-subdivided charge of carbide, in F^1 the water enters at the top, and in F^3 it enters at the bottom. Thus it happens that the mixture of acetylene and steam, which is produced at the spot where the primary chemical reaction is taking place, has to travel through the entire mass of carbide present in a generator belonging to type F^3, while in F^1 the damp gas flows directly to the exit pipe without having to penetrate the lumps of solid. Both F^1 and F^3 exhibit after-generation caused by a reaction between the liquid water mechanically clinging to the mass of spent lime and the excess of carbide to an approximately equal extent; but for the reason just mentioned, after-generation due to a reaction between the vaporised water accompanying the acetylene first evolved and the excess of carbide is more noticeable in F^3 than in F^1; and it is precisely this latter description of after-generation which leads to overheating of the most ungovernable kind. Naturally both F^1 and F^3 can be fitted with water jackets, as is indicated by the dotted lines in the second sketch; but unless the generating chamber in quite small and the evolution of gas quite slow, the cooling action of the jacket will not prove sufficient. As the water in F^1 and F^3 is not capable of backward motion, the decomposing chambers cannot be employed as displacement holders, as is the case in the dipping generator pictured at B^1, Fig. 2. They must be coupled, accordingly, to a separate holder of the displacement or, preferably, of the rising type; and, in order that the gas evolved by after-generation may not be wasted, the automatic mechanism must cut off the supply of water to the generator by the time that holder is two-thirds or three-quarters full. [Illustration: FIG. 4.--TYPICAL METHODS OF DECOMPOSING CARBIDE (WATER TO CARBIDE).] [Illustration: FIG. 5.--TYPICAL METHODS OF DECOMPOSING CARBIDE (WATER TO CARBIDE).] The diagrams G, H, and K in Figs. 4 and 5 represent three different methods of constructing a generator which belongs either to the contact type (F^3) if the supply of water is essentially continuous, _i.e._, if less is admitted at each movement of the feeding mechanism than is sufficient to submerge the carbide in each receptacle; or to the flooded- compartment type (F') if the water enters in large quantities at a time. In H the main carbide vessel is arranged horizontally, or nearly so, and each partition dividing it into compartments is taller than its predecessor, so that the whole of the solid in (1) must be decomposed, and the compartment entirely filled with liquid before it can overflow into (2), and so on. Since the carbide in all the later receptacles is exposed to the water vapour produced in that one in which decomposition is proceeding at any given moment, at least at its upper surface, some after-generation between vapour and carbide occurs in H; but a partial control over the temperature may be obtained by water-jacketing the container. In G the water enters at the base and gas escapes at the top, the carbide vessels being disposed vertically; hero, perhaps, more after- generation of the same description occurs, as the moist gas streams round and over the higher baskets. In K, the water enters at the top and must completely fill basket (1) before it can run down the depending pipe into (2); but since the gas also leaves the generator at the top, the later carbide receptacles do not come in contact with water vapour, but are left practically unattacked until their time arrives for decomposition by means of liquid water. K, therefore, is the best arrangement of parts to avoid after-generation, overheating, and polymerisation of the acetylene whether the generator be worked as a contact or as a flooded-compartment apparatus; but it may be freely admitted that the extent of the overheating due to reaction between water vapour and carbide may be kept almost negligible in either K, H, or G, provided the partitions in the carbide container be sufficient in number--provided, that is to say, that each compartment holds a sufficiently small quantity of carbide; and provided that the quantity of water ultimately required to fill each compartment is relatively so large that the temperature of the liquid never approaches the boiling-point where vaporisation is rapid. The type of generator indicated by K has not become very popular, but G is fairly common, whilst H undoubtedly represents the apparatus which is most generally adopted for use in domestic and other private installations in the United Kingdom and the Continent of Europe. The actual generators made according to the design shown by H usually have a carbide receptacle designed in the form of a semi-cylindrical or rectangular vessel of steel sliding fairly closely into an outside container, the latter being either built within the main water space of the entire apparatus or placed within a separate water-jacketed casing. Owing to its shape and the sliding motion with which the carbide receptacle is put into the container these generators are usually termed "drawer" generators. In comparison with type G, the drawer generator H certainly exhibits a lower rise in temperature when gas is evolved in it at a given speed and when the carbide receptacles are constructed of similar dimensions. It is very desirable that the whole receptacle should be subdivided into a sufficient number of compartments and that it should be effectively water-cooled from outside. It would also be advantageous if the water- supply were so arranged that the generator should be a true flooded- compartment apparatus, but experience has nevertheless shown that generators of type H do work very well when the water admitted to the carbide receptacle, each time the feed comes into action, is not enough to flood the carbide in one of the compartments. Above a certain size drawer generators are usually constructed with two or even more complete decomposing vessels, arrangements being such that one drawer can be taken out for cleaning, whilst the other is in operation. When this is the case a third carbide receptacle should always be employed so that it may be dry, lit to receive a charge of carbide, and ready to insert in the apparatus when one of the others is withdrawn. The water-feed should always be so disposed that the attendant can see at a glance which of the two (or more) carbide receptacles is in action at any moment, and it should be also so designed that the supply is automatically diverted to the second receptacle when the first is wholly exhausted and back again to the first (unless there are more than two) when the carbide in the second is entirely gasified. In the sketches G, H, and K, the total space occupied by the various carbide receptacles is represented as being considerably smaller than the capacity of the decomposing chamber. Were this method of construction copied in actual acetylene apparatus, the first makes of gas would be seriously (perhaps dangerously) contaminated with air. In practice the receptacles should fit so tightly into the outer vessel and into one another that when loaded to the utmost extent permissible--space being left for the swelling of the charge and for the passage of water and gas--but little room should be left for the retention of air in the chamber. ACTION OF CARBIDE-TO-WATER GENERATORS.--The methods which may be adopted to render a generator automatic when carbide is employed as the moving material are shown at M, N, and P, in Fig. 6; but the precise devices used in many actual apparatus are so various that it is difficult to portray them generically. Moreover it is desirable to subdivide automatic carbide-to-water generators, according to the size of the carbide they are constructed to take, into two or three classes, which are termed respectively "large carbide-feed," "small carbide-feed," and "granulated carbide-feed" apparatus. (The generator represented at L does not really belong to the present class, being non-automatic and fed by hand; but the sketch is given for completeness.) M is an automatic carbide-feed generator having its store of carbide in a hopper carried by the rising- holder bell. The hopper is narrowed at its mouth, where it is closed by a conical or mushroom valve _d_ supported on a rod held in suitable guides. When the bell falls by consumption of gas, it carries the valve and rod with it; but eventually the button at the base of _c_ strikes the bottom of the generator, or some fixed distributing plate, and the rod can descend no further. Then, when the bell falls lower, the mushroom _d_ rises from its seat, and carbide drops from the hopper into the water. This type of apparatus has the defect characteristic of A^2, Fig. 1; for the pressure in the service steadily diminishes as the effective weight of bell plus hopper decreases by consumption of carbide. But it has also two other defects--(1) that ordinary carbide is too irregular in shape to fall smoothly through the narrow annular space between the valve and its seat; (2) that water vapour penetrates into the hopper, and liberates some gas there, while it attacks the lumps of carbide at the orifice, producing dust or causing them to stick together, and thus rendering the action of the feed worse than ever. Most of these defects can be avoided by using granulated carbide, which is more uniform in size and shape, or by employing a granulated and "treated" carbide which has been dipped in some non-aqueous liquid to make it less susceptible to the action of moisture. Both these plans, however, are expensive to adopt; first, because of the actual cost of granulating or "treating" the carbide; secondly, because the carbide deteriorates in gas-making capacity by its inevitable exposure to air during the granulating or "treating" process. The defects of irregularity of pressure and possible waste of gas by evolution in the hopper may be overcome by disposing the parts somewhat differently; making the holder an annulus round the hopper, or making it cylindrical with the hopper inside. In this case the hopper is supported by the main portion of the apparatus, and does not move with the bell: the rod and valve being given their motion in some fashion similar to that figured. Apparatus designed in accordance with the sketch M, or with the modification just described, are usually referred to under the name of "hopper" generators. On several occasions trouble has arisen during their employment owing to the jamming of the valve, a fragment of carbide rather larger than the rest of the material lodging between the lips of the hopper and the edges of the mushroom valve. This has been followed by a sudden descent of all the carbide in the store into the water beneath, and the evolution of gas has sometimes been too rapid to pass away at the necessary speed into the holder. The trouble is rendered even more serious should the whole charge of carbide fall at a time when, by neglect or otherwise, the body of the generator contains much lime sludge, the decomposition then proceeding under exceptionally bad circumstances, which lead to the production of an excessively high temperature. Hopper generators are undoubtedly very convenient for certain purposes, chiefly, perhaps, for the construction of table-lamps and other small installations. Experience tends to show that they may be employed, first, provided they are designed to take granulated carbide--which in comparison with larger grades is much more uniform and cylindrical in shape--and secondly, provided the quantity of carbide in the hopper does not exceed a few pounds. The phenomenon of the sudden unexpected descent of the carbide, popularly known as "dumping," can hardly be avoided with carbide larger in size than the granulated variety; and since the results of such an accident must increase in severity with the size of the apparatus, a limit in their capacity is desirable. [Illustration: FIG. 6.--TYPICAL METHODS OF DECOMPOSING CARBIDE (CARBIDE TO WATER).] When it is required to construct a carbide-feed generator of large size or one belonging to the large carbide-feed pattern, it is preferable to arrange the store in a different manner. In N the carbide is held in a considerable number of small receptacles, two only of which are shown in the drawing, provided with detachable lids and hinged bottoms kept shut by suitable catches. At proper intervals of time those catches in succession are knocked on one side by a pin, and the contents of the vessel fall into the water. There are several methods available for operating the pins. The rising-holder bell may be made to actuate a train of wheels which terminate in a disc revolving horizontally on a vertical axis somewhere just below the catches; and this wheel may bear an eccentric pin which hits each catch as it rotates. Alternatively the carbide boxes may be made to revolve horizontally on a vertical axis by the movements of the bell communicated through a clutch; and thus each box in succession may arrive at a certain position where the catch is knocked aside by a fixed pin. The boxes, again, may revolve vertically on a horizontal axis somewhat like a water-wheel, each box having its bottom opened, or, by a different system of construction, being bodily upset, when it arrives at the bottom of its circular path. In no case, however, are the carbide receptacles carried by the bell, which is a totally distinct part of the apparatus; and therefore in comparison with M, the pressure given by the bell is much more uniform. Nevertheless, if the system of carbide boxes moves at all, it becomes easier to move by decrease in weight and consequent diminution in friction as the total charge is exhausted; and accordingly the bell has less work to do during the later stages of its operation. For this reason the plan actually shown at N is preferable, since the work done by the moving pin, _i.e._, by the descending bell, is always the same. P represents a carbide-feed effected by a spiral screw or conveyor, which, revolved periodically by a moving bell, draws carbide out of a hopper of any desired size and finally drops it into a shoot communicating with a generating chamber such as that shown in L. Here the work done by the bell is large, as the friction against the blades of the screw and the walls of the horizontal tube is heavy; but that amount of work must always be essentially identical. The carbide-feed may similarly be effected by means of some other type of conveyor instead of the spiral screw, such as an endless band, and the friction in these cases may be somewhat less than with the screw, but the work to be done by the bell will always remain large, whatever type of conveyor may be adopted. A further plan for securing a carbide-feed consists in employing some extraneous driving power to propel a charge of carbide out of a reservoir into the generator. Sometimes the propulsive effort is obtained from a train of clockwork, sometimes from a separate supply of water under high pressure. The clockwork or the water power is used either to drive a piston travelling through the vessel containing the carbide so that the proper quantity of material is dropped over the open mouth of a shoot, or to upset one after another a series of carbide receptacles, or to perform some analogous operation. In these cases the pin or other device fitted to the acetylene apparatus itself has nothing to do beyond releasing the mechanism in question, and therefore the work required from the bell is but small. The propriety of employing a generator belonging to these latter types must depend upon local conditions, _e.g._, whether the owner of the installation has hydraulic power on a small scale (a constant supply of water under sufficient pressure) at disposal, or whether he does not object to the extra labour involved in the periodical winding up of a train of clockwork. It must be clear that all these carbide-feed arrangements have the defect in a more or less serious degree of leaving the carbide in the main storage vessel exposed to the attack of water vapour rising from the decomposing chamber, for none of the valves or operating mechanism can be made quite air-tight. Evolution of gas produced in this way does not matter in the least, because it is easy to return the gas so liberated into the generator or into the holder; while the extent of the action, and the consequent production of overheating, will tend to be less than in generators such as those shown in G and H of Figs. 4 and 5, inasmuch as the large excess of water in the carbide-feed apparatus prevents the liquid arriving at a temperature at which it volatilises rapidly. The main objection to the evolution of gas in the carbide vessel of a carbide-to-water generator depends on the danger that the smooth working of the feed-gear may be interfered with by the formation of dust or by the aggregation of the carbide lumps. USE OF OIL IN GENERATORS.--Calcium carbide is a material which is only capable of attack for the purpose of evolving acetylene by a liquid that is essentially water, or by one that contains some water mixed with it. Oils and the like, or even such non-aqueous liquids as absolute alcohol, have no effect upon carbide, except that the former naturally make it greasy and somewhat more difficult to moisten. This last property has been found of service in acetylene generation, especially on the small scale; for if carbide is soaked in, or given a coating of, some oil, fat, or solid hydrocarbon like petroleum, cocoanut oil, or paraffin wax, the substance becomes comparatively indifferent towards water vapour or the moisture present in the air, while it still remains capable of complete, albeit slow, decomposition by liquid water when completely immersed therein. The fact that ordinary calcium carbide is attacked so quickly by water is really a defect of the substance; for it is to this extreme rapidity of reaction that the troubles of overheating are due. Now, if the basket in the generator B^1 of Fig. 2, or, indeed, the carbide store in any of the carbide-to-water apparatus, is filled with a carbide which has been treated with oil or wax, as long as the water-level stands at _l'_ and _l"_ or the carbide still remains in the hopper, it is essentially unattacked by the vapour arising from the liquid; but directly the basket is submerged, or the lumps fall into the water, acetylene is produced, and produced more slowly and regularly than otherwise. Again, oils do not mix with water, but usually float thereon, and a mass of water covered by a thick film or layer of oil does not evaporate appreciably. If, now, a certain quantity of oil, say lamp paraffin or mineral lubricating oil, is poured on to the water in B^1, Fig. 2, it moves upwards and downwards with the water. When the water takes the position _l_, the oil is driven upwards away from the basket of carbide, and acetylene is generated in the ordinary manner; but when the water falls to _l"_ the oil descends also, rinses off much of the adhering water from the carbide lumps, covers them with a greasy film, and almost entirely stops generation till it is in turn washed off by the next ascent of the water. Similarly, if the carbide in generators F, G, and H (also K) has been treated with a solid or semi-solid grease, it is practically unattacked by the stream of warm damp gas, and is only decomposed when the liquid itself arrives in the basket. For the same reason treated carbide can be kept for fairly long periods of time, even in a drum with badly fitting lid, without suffering much deterioration by the action of atmospheric moisture. The problem of acetylene generation is accordingly simplified to a considerable degree by the use of such treated carbide, and the advantage becomes more marked as the plant decreases in size till a portable apparatus is reached, because the smaller the installation the more relatively expensive or inconvenient is a large holder for surplus gas. The one defect of the method is the extra cost of such treated carbide; and in English conditions ordinary calcium carbide is too expensive to permit of any additional outlay upon the acetylene if it is to compete with petroleum or the product of a tiny coal-gas works. The extra cost of using treated carbide falls upon the revenue account, and is much more noticeable than that of a large holder, which is capital expenditure. When fluid oil is employed in a generator of type B^1, evolution of gas becomes so regular that any holder beyond the displacement one which the apparatus itself constitutes is actually unnecessary, though still desirable; but B^1, with or without oil, still remains a displacement apparatus, and as such gives no constant pressure. It must be admitted that the presence of oil so far governs the evolution of gas that the movement of the water, and the consequent variation of pressure, is rendered very small; still a governor or a rising holder would be required to give the best result at the burners. One point in connexion with the use of liquid oil must not be overlooked, viz., the extra trouble it may give in the disposal of the residues. This matter will be dealt with more fully in Chapter V.; here it is sufficient to say that as the oil does not mix with the water but floats on the surface, care has to be taken that it is not permitted to enter any open stream. The foregoing remarks about the use of oil manifestly only apply to those cases where it is used in quantity and where it ultimately becomes mixed with the sludge or floats on the water in the decomposing chamber. The employment of a limpid oil, such as paraffin, as an intermediate liquid into which carbide is introduced on its way to the water in the decomposing vessel of a hand-fed generator in the manner described on page 70 is something quite different, because, except for trifling losses, one charge of oil should last indefinitely. RISING GASHOLDERS.--Whichever description of holder is employed in an acetylene apparatus, the gas is always stored over, or in contact with, a liquid that is essentially water. This introduces three subjects for consideration: the heavy weight of a large body of liquid, the loss of gas by dissolution in that liquid, and the protection of that liquid from frost in the winter. The tanks of rising holders are constructed in two different ways. In one the tank is a plain cylindrical vessel somewhat larger in diameter than the bell which floats in it; and since there must be nearly enough water in the tank to fill the interior of the bell when the latter assumes its lowest position, the quantity of water is considerable, its capacity for dissolving acetylene is large, and the amount of any substance that may have to be added to it to lower its freezing-point becomes so great as to be scarcely economical. All these defects, including that of the necessity for very substantial foundations under the holder to support its enormous weight, may be overcome by adopting the second method of construction. It is clear that the water in the centre of the tank is of no use,--all that is needed being a narrow trough for the bell to work in. Large rising holders are therefore advantageously built with a tank formed in the shape of an annulus, the effective breadth of which is not more than 2 or 3 inches, the centre portion being roofed over so as to prevent escape of gas. The same principle may be retained with modified details by fitting inside a plain cylindrical tank a "dummy" or smaller cylinder, closed by a flat or curved top and fastened water- and air-tight to the bottom of the main vessel. The construction of annular tanks or the insertion of a "dummy" may be attended with difficulty if the tank is wholly or partly sunk below the ground level, owing to the lifting force of water in the surrounding soil. Where a steel tank is sunk, or a masonry tank is constructed, regard must be paid, both in the design of the tank and in the manner of construction, to the level of the underground water in the neighbourhood, as in certain cases special precautions will be needed to avoid trouble from the pressure of the water on the outside of the tank until it is balanced by the pressure of the water with which the tank is filled. So far as mere dissolution of gas is concerned, the loss may be reduced by having a circular disc of wood, &c., a little smaller in diameter than the boll, floating on the water of a plain tank. EFFECT OF STORAGE IN GASHOLDER ON ACETYLENE.--It is perfectly true, as has been stated elsewhere, that the gas coming from an acetylene generator loses some of its illuminating power if it is stored over water for any great length of time; such loss being given by Nichols as 94 per cent, in five months, and having been found by one of the authors as 0.63 per cent. per day--figures which stand in fair agreement with one another. This wastage is not due to any decomposition of the acetylene in contact with water, but depends on the various solubilities of the different gases which compose the product obtained from commercial calcium carbide. Inasmuch as an acetylene evolved in the best generator contains some foreign ingredients, and inasmuch as an inferior product contains more (_cf._ Chapter V.), the contents of a holder are never pure; but as those contents are principally made up of acetylene itself, that gas stands at a higher partial pressure in the holder than the impurities. Since acetylene is more soluble in water than any of its diluents or impurities, sulphuretted hydrogen and ammonia excepted, and since the solubility of all gases increases as the pressure at which they are stored rises, the true acetylene in an acetylene holder dissolves in the water more rapidly and comparatively more copiously than the impurities; and thus the acetylene tends to disappear and the impurities to become concentrated within the bell. Simultaneously at the outer part of the seal, air is dissolved in the water; and by processes of diffusion the air so dissolved passes through the liquid from the outside to the inside, where it escapes into the bell, while the dissolved acetylene similarly passes from the inside to the outside of the seal, and there mingles with the atmosphere. Thus, the longer a certain volume of acetylene is stored over water, the more does it become contaminated with the constituents of the atmosphere and with the impurities originally present in it; while as the acetylene is much more soluble than its impurities, more gas escapes from, than enters, the holder by diffusion, and so the bulk of stored gas gradually diminishes. However, the figures previously given show that this action is too slow to be noticeable in practice, for the gas is never stored for more than a few days at a time. The action cannot be accepted as a valid argument against the employment of a holder in acetylene plant. Such deterioration and wastage of gas may be reduced to some extent by the use of a film of some cheap and indifferent oil floating on the water inside an acetylene holder; the economy being caused by the lower solubility of acetylene in oils than in aqueous liquids not saturated with some saline material. Probably almost any oil would answer equally well, provided it was not volatile at the temperature of the holder, and that it did not dry or gum on standing, _e.g._, olive oil or its substitutes; but mineral lubricating oil is not so satisfactory. It is, however, not necessary to adopt this method in practice, because the solvent power of the liquid in the seal can be reduced by adding to it a saline body which simultaneously lowers its freezing-point and makes the apparatus more trustworthy in winter. FREEZING OF GASHOLDER SEAL.--The danger attendant upon the congelation of the seal in an acetylene holder is very real, not so much because of the fear that the apparatus may be burst, which is hardly to be expected, as because the bell will be firmly fixed in a certain position by the ice, and the whole establishment lighted by the gas will be left in darkness. In these circumstances, hurried and perhaps injudicious attempts may be made to thaw the seal by putting red-hot bars into it or by lighting fires under it, or the generator-house may be thoughtlessly entered with a naked light at a time when the apparatus is possibly in disorder through the loss of storage-room for the gas it is evolving. Should a seal ever freeze, it must be thawed only by the application of boiling water; and the plant-house must be entered, if daylight has passed, in perfect darkness or with the assistance of an outside lamp whining through a closed window. [Footnote: By "closed window" is to be understood one incapable of being opened, fitted with one or two thicknesses of stout glass well puttied in, and placed in a wall of the house as far as possible from the door.] There are two ways of preventing the seal from freezing. In all large installations the generator-house will be fitted with a warm-water heating apparatus to protect the portion of the plant where the carbide is decomposed, and if the holder is also inside the same building it will naturally be safe. If it is outside, one of the flow-pipes from the warming apparatus should be led into and round the lowest part of the seal, care being taken to watch for, or to provide automatic arrangements for making good, loss of water by evaporation. If the holder is at a distance from the generator-house, or if for any other reason it cannot easily be brought into the warming circuit, the seal can be protected in another way; for unlike the water in the generator, the water in the holder-seal will perform its functions equally well however much it be reduced in temperature, always providing it is maintained in the liquid condition. There are numerous substances which dissolve in, or mix with, water, and yield solutions or liquids that do not solidify until their temperature falls far below that of the natural freezing- point. Assuming that those substances in solution do not attack the acetylene, nor the metal of which the holder is built, and are not too expensive, choice may be made between them at will. Strictly speaking the cost of using them is small, because unless the tank is leaky they last indefinitely, not evaporating with the water as it is vaporised into the gas or into the air. The water-seal of a holder standing within the generator-house may eventually become so offensive to the nostrils that the liquid has to be renewed; but when this happens it is due to the accumulation in the water of the water-soluble impurities of the crude acetylene. If, as should be done, the gas is passed through a washer or condenser containing much water before it enters the holder the sulphuretted hydrogen and ammonia will be extracted, and the seal will not acquire an obnoxious odour for a very long time. Four principal substances have been proposed for lowering the freezing- point of the water in an acetylene-holder seal; common salt (sodium chloride), calcium chloride (not chloride of lime), alcohol (methylated spirit), and glycerin. A 10 per cent. solution of common salt has a specific gravity of 1.0734, and does not solidify above -6° C. or 21.2° F.; a 15 per cent. solution has a density of 1.111, and freezes at -10° C. or 14° F. Common salt, however, is not to be recommended, as its solutions always corrode iron and steel vessels more or less quickly. Alcohol, in its English denatured form of methylated spirit, is still somewhat expensive to use, but it has the advantage of not increasing the viscosity of the water; so that a frost-proof mixture of alcohol and water will flow as readily through minute tubes choked with needle- valves, or through felt and the like, or along wicks, as will plain water. For this reason, and for the practically identical one that it is quite free from dirt or insoluble matter, diluted spirit is specially suitable for the protection of the water in cyclists' acetylene lamps, [Footnote: As will appear in Chapter XIII., there is usually no holder in a vehicular acetylene lamp, all the water being employed eventually for the purpose of decomposing the carbide. This does not affect the present question. Dilute alcohol does not attack calcium carbide so energetically as pure water, because it stands midway between pure water and pure alcohol, which is inert. The attack, however, of the carbide is as complete as that of pure water, and the slower speed thereof is a manifest advantage in any holderless apparatus.] where strict economy is less important than smooth working. For domestic and larger installations it is not indicated. As between calcium chloride and glycerin there is little to choose; the former will be somewhat cheaper, but the latter will not be prohibitively expensive if the high-grade pure glycerins of the pharmacist are avoided. The following tables show the amount of each substance which must be dissolved in water to obtain a liquid of definite solidifying point. The data relating to alcohol were obtained by Pictet, and those for calcium chloride by Pickering. The latter are materially different from figures given by other investigators, and perhaps it would be safer to make due allowance for this difference. In Germany the Acetylene Association advocates a 17 per cent. solution of calcium chloride, to which Frank ascribes a specific gravity of 1.134, and a freezing-point of -8° C. or 17.6° F. _Freezing-Points of Dilute Alcohol._ _________________________________________________________ | | | | | Percentage of | Specific Gravity. | Freezing-point. | | Alcohol. | | | |_______________|___________________|_____________________| | | | | | | | | Degs. C. | Degs. F. | | 4.8 | 0.9916 | -2.0 | +28.4 | | 11.3 | 0.9824 | 5.0 | 23.0 | | 16.4 | 0.9761 | 7.5 | 18.5 | | 18.8 | 0.9732 | 9.4 | 15.1 | | 20.3 | 0.9712 | 10.6 | 12.9 | | 22.1 | 0.9689 | 12.2 | 10.0 | | 24.2 | 0.9662 | 14.0 | 6.8 | | 26.7 | 0.9627 | 16.0 | 3.2 | | 29.9 | 0.9578 | 18.9 | -2.0 | |_______________|___________________|__________|__________| _Freezing-Points of Dilute Glycerin._ _________________________________________________________ | | | | | Percentage of | Specific Gravity. | Freezing-point. | | Glycerin. | | | |_______________|___________________|_____________________| | | | | | | | | Degs. C. | Degs. F. | | 10 | 1.024 | -1.0 | +30.2 | | 20 | 1.051 | 2.5 | 27.5 | | 30 | 1.075 | 6.0 | 21.2 | | 40 | 1.105 | 17.5 | 0.5 | | 50 | 1.127 | 31.3 | -24.3 | |_______________|___________________|__________|__________| _Freezing-Points of Calcium Chloride Solutions._ _________________________________________________________ | | | | | Percentage of | Specific Gravity. | Freezing-point. | | CaCl_2. | | | |_______________|___________________|_____________________| | | | | | | | | Degs. C. | Degs. F. | | 6 | 1.05 | -3.0 | +26.6 | | 8 | 1.067 | 4.3 | 24.3 | | 10 | 1.985 | 5.9 | 21.4 | | 12 | 1.103 | 7.7 | 18.1 | | 14 | 1.121 | 9.8 | 14.4 | | 16 | 1.140 | 12.2 | 10.0 | | 18 | 1.159 | 15.2 | 4.6 | | 20 | 1.170 | 18.6 | -1.5 | |_______________|___________________|__________|__________| Calcium chloride will probably be procured in the solid state, but it can be purchased as a concentrated solution, being sold under the name of "calcidum" [Footnote: This proprietary German article is a liquid which begins to solidify at -42° C. (-43.6° F.), and is completely solid at -56° C. (-69)° F.). Diluted with one-third its volume of water, it freezes between -20° and -28° C. (-4° and-l8.4° F.). The makers recommend that it should be mixed with an equal volume of water. Another material known as "Gefrierschutzflüssigkeit" and made by the Flörsheim chemical works, freezes at -35° C. (-3° F.). Diluted with one-quarter its volume of water, it solidifies at -18° C. (-0.4° F.); with equal parts of water it freezes at -12° C. (10.4° F.). A third product, called "calcidum oxychlorid," has been found by Caro and Saulmann to be an impure 35 per cent. solution of calcium chloride. Not one of these is suitable for addition to the water used in the generating chamber of an acetylene apparatus, the reasons for this having already been mentioned.] for the protection of gasholder seals. Glycerin itself resembles a strong solution of calcium chloride in being a viscid, oily-looking liquid; and both are so much heavier than water that they will not mix with further quantities unless they are thoroughly agitated therewith. Either may be poured through water, or have water floated upon it, without any appreciable admixture taking place; and therefore in first adding them to the seal great care must be taken that they are uniformly distributed throughout the liquid. If the whole contents of the seal cannot conveniently be run into an open vessel in which the mixing can be performed, the sealing water must be drawn off a little at a time and a corresponding quantity of the protective reagent added to it. Care must be taken also that motives of economy do not lead to excessive dilution of the reagent; the seal must be competent to remain liquid under the prolonged influence of the most severe frost ever known to occur in the neighbourhood where the plant is situated. If the holder is placed out of doors in an exposed spot where heavy rains may fall on the top of the bell, or where snow may collect there and melt, the water is apt to run down into the seal, diluting the upper layers until they lose the frost- resisting power they originally had. This danger may be prevented by erecting a sloping roof over the bell crown, or by stirring up the seal and adding more preservative whenever it has been diluted with rain water. Quite small holders would probably always be placed inside the generator-house, where their seals may be protected by the same means as are applied to the generator itself. It need hardly be said that all remarks about the dangers incidental to the freezing of holder seals and the methods for obviating them refer equally to every item in the acetylene plant which contains water or is fitted with a water-sealed cover; only the water which is actually used for decomposing the calcium carbide cannot be protected from frost by the addition of calcium chloride or glycerin--that water must be kept from falling to its natural freezing-point. From Mauricheau-Beaupré's experiments, referred to on page 106, it would appear that a further reason for avoiding an addition of calcium chloride to the water used for decomposing carbide should lie in the danger of causing a troublesome production of froth within the generator. It will be convenient to digress here for the purpose of considering how the generators of an acetylene apparatus themselves should be protected from frost; but it may be said at the outset that it is impossible to lay down any fixed rules applicable to all cases, since local conditions, such as climate, available resources, dimensions, and exposed or protected position of the plant-house vary so largely in different situations. In all important installations every item of the plant, except the holder, will be collected in one or two rooms of a single building constructed of brick or other incombustible material. Assuming that long-continued frost reigns at times in the neighbourhood, the whole of such a building, with the exception of one apartment used as a carbide store only, is judiciously fitted with a heating arrangement like those employed in conservatories or hothouses; a system of pipes in which warm water is kept circulating being run round the walls of each chamber near the floor. The boiler, heated with coke, paraffin, or even acetylene, must naturally be placed in a separate room of the apparatus-house having no direct (indoor) communication with the rooms containing the generators, purifiers, &c. Instead of coils of pipe, "radiators" of the usual commercial patterns may be adopted; but the immediate source of heat should be steam, or preferably hot water, and not hot air or combustion products from the stove. In exposed situations, where the holder is out of doors, one branch of the flow-pipe should enter and travel round the seal as previously suggested. Most large country residences are already provided with suitable heating apparatus for warming the greenhouses, and part of the heat may be capable of diversion into the acetylene generator-shed if the latter is erected in a convenient spot. In fact, if any existing hot-water warming appliances are already at hand, and if they are powerful enough to do a little more work, it may be well to put the generator-building in such a position that it can be efficiently supplied with artificial warmth from those boilers; for any extra length of main necessary to lead the gas into the residence from a distant generator will cost less on the revenue account than the fuel required to feed a special heating arrangement. In smaller installations, especially such as are to be found in mild climates, it may be possible to render the apparatus-house sufficiently frost-proof without artificial heat by building it partly underground, fitting it with a double skylight in place of a window for the entrance of daylight, and banking up its walls all round with thick layers of earth. The house must have a door, however, which must open outwards and easily, so that no obstacle may prevent a hurried exit in emergencies. Such a door can hardly be made very thick or double without rendering it heavy and difficult to open; and the single door will be scarcely capable of protecting the interior if the frost is severe and prolonged. Ventilators, too, must be provided to allow of the escape of any gas that may accidentally issue from the plant during recharging, &c.; and some aperture in the roof will be required for the passage of the vent pipe or pipes, which, in certain types of apparatus, move upwards and downwards with the bell of the holder. These openings manifestly afford facilities for the entry of cold air, so that although this method of protecting generator-houses has proved efficient in many places, it can only be considered inferior to the plan of installing a proper heating arrangement. Occasionally, where local regulations do not forbid, the entire generator-house may be built as a "lean-to" against some brick wall which happens to be kept constantly warm, say by having a furnace or a large kitchen stove on its other side. In less complicated installations, where there are only two distinct items in the plant to be protected from frost--generator and holder--or where generator and holder are combined into one piece of apparatus, other methods of warming become possible. As the reaction between calcium carbide and water evolves much heat, the most obvious way of preventing the plant from freezing is to economise that heat, _i.e._, to retain as much of it as is necessary within the apparatus. Such a process, clearly, is only available if the plant is suitable in external form, is practically self-contained, and comprises no isolated vessels containing an aqueous liquid. It is indicated, therefore, rather for carbide-to- water generators, or for water-to-carbide apparatus in which the carbide chambers are situated inside the main water reservoir--any apparatus, in fact, where much water is present and where it is all together in one receptacle. Moreover, the method of heat economy is suited for application to automatic generators rather than to those belonging to the opposite system, because automatic apparatus will be generating gas, and consequently evolving heat, every evening till late at night--just at the time when frost begins to be severe. A non-automatic generator will usually be at work only in the mornings, and its store of heat will accordingly be much more difficult to retain till nightfall. With the object of storing up the heat evolved in the generator, it must be covered with some material possessed of the lowest heat-conducting power possible; and the proper positions for that material in order of decreasing importance are the top, sides, and bottom of the plant. The generator may either be covered with a thick layer of straw, carpet, flannel, or the like, as is done in the protection of exposed water- pipes; or it may be provided with a jacket filled with some liquid. In view of the advisability of not having any organic or combustible material near the generator, the solid substances just mentioned may preferably be replaced by one of those partially inorganic compositions sold for "lagging" steam-pipes and engine-cylinders, such as "Fossil meal." Indeed, the exact nature of the lagging matters comparatively little, because the active substance in retaining the heat in the acetylene generator or the steam-pipe is the air entangled in the pores of the lagging; and therefore the value of any particular material depends mainly on its exhibiting a high degree of porosity. The idea of fitting a water jacket round an acetylene generator is not altogether good, but it may be greatly improved upon by putting into the jacket a strong solution of some cheap saline body which has the property of separating from its aqueous solution in the form of crystals containing water of crystallisation, and of evolving much heat in so separating. This method of storing much heat in a small space where a fire cannot be lighted is in common use on some railways, where passengers' foot-warmers are filled with a strong solution of sodium acetate. When sodium acetate is dissolved in water it manifestly exists in the liquid state, and it is presumably present in its anhydrous condition (i.e., not combined with water of crystallisation). The common crystals are solid, and contain 3 molecules of water of crystallisation--also clearly in the solid state. Now, the reaction NaC_2H_3O_2 + 3H_2O = NaC_2H_3O_2.3H_2O (anhydrous acetate) (crystals) evolves 4.37 calories (Berthelot), or 1.46 calorie for each molecule of water; and whereas 1 kilo. of water only evolves 1 large calorie of heat as its temperature falls 1° C., 18 grammes of water (1 gramme-molecule) evolve l.46 large calorie when they enter into combination with anhydrous sodium acetate to assist in forming crystals--and this 1.46 calorie may either be permitted to warm the mass of crystals, or made to do useful work by raising the temperature of some adjacent substance. Sodium acetate crystals dissolve in 3.9 parts by weight of water at 6° C. (43° F.) or in 2.4 parts at 37° C. (99° F.). If, then, a jacket round an acetylene apparatus is filled with a warm solution of sodium acetate crystals in (say) 3 parts by weight of water, the liquid will crystallise when it reaches some temperature between 99° and 43° F.; but when the generator comes into action, the heat liberated will change the mass of crystals into a liquid without raising its sensible temperature to anything like the extent that would happen were the jacket full of simple water. Not being particularly warm to the touch, the liquefied product in the jacket will not lose much heat by radiation, &c., into the surrounding air; but when the water in the generator falls again (after evolution of acetylene ceases) the contents of the jacket will also cool, and finally will begin to crystallise once more, passing a large amount of low-temperature heat into the water of the generator, and safely maintaining it for long periods of time at a temperature suitable for the further evolution of gas. Like the liquid in the seal of an isolated gasholder, the liquid in such a jacket will last indefinitely; and therefore the cost of the sodium acetate in negligible. Another method of keeping warm the water in any part of an acetylene installation consists in piling round the apparatus a heap of fresh stable manure, which, as is well known, emits much heat as it rots. Where horses are kept, such a process may be said to cost nothing. It has the advantage over methods of lagging or jacketing that the manure can be thrown over any pipe, water-seal, washing apparatus, &c., even if the plant is constructed in several separate items. Unfortunately the ammonia and the volatile organic compounds which are produced during the natural decomposition of stable manure tend seriously to corrode iron and steel, and therefore this method of protecting an apparatus from frost should only be employed temporarily in times of emergency. CORROSION IN APPARATUS.--All natural water is a solution of oxygen and may be regarded also as a weak solution of the hypothetical carbonic acid. It therefore causes iron to rust more or less quickly; and since no paint is absolutely waterproof, especially if it has been applied to a surface already coated locally with spots of rust, iron and steel cannot be perfectly protected by its aid. More particularly at a few inches above and below the normal level of the water in a holder, therefore, the metal soon begins to exhibit symptoms of corrosion which may eventually proceed until the iron is eaten away or becomes porous. One method of prolonging the life of such apparatus is to give it fresh coats of paint periodically; but unless the old layers are removed where they have cracked or blistered, and the rust underneath is entirely scraped off (which is practically impossible), the new paint films will not last very long. Another more elegant process for preserving any metal like iron which is constantly exposed to the attack of a corrosive liquid, and which is readily applicable to acetylene holders and their tanks, depends on the principle of galvanic action. When two metals in good electrical contact are immersed in some liquid that is capable of attacking both, only that metal will be attacked which is the more electro-positive, or which (the same thing in other words) is the more readily attacked by the liquid, evolving the more heat during its dissolution. As long as this action is proceeding, as long, that is, as some of the more electro- positive material is present, the less electro-positive material will not suffer. All that has to be done, therefore, to protect the walls of an acetylene-holder tank and the sides of its bell is to hang in the seal, supported by a copper wire fastened to the tank walls by a trustworthy electrical joint (soldering or riveting it), a plate or rod of some more electro-positive metal, renewing that plate or rod before it is entirely eaten away. [Footnote: Contact between the bell and the rod may be established by means of a flexible metallic wire; or a separate rod might be used for the bell itself.] If the iron is bare or coated with lead (paint may be overlooked), the plate may be zinc; if the iron is galvanised, _i.e._, coated with zinc, the plate may be aluminium or an alloy of aluminium and zinc. The joint between the copper wire and the zinc or aluminium plate should naturally be above the water-level. The foregoing remarks should be read in conjunction with what was said in Chapter II., about the undesirability of employing a soft solder containing lead in the construction of an acetylene generator. Here it is proposed intentionally to set up a galvanic couple to prevent corrosion; there, with the same object in view, the avoidances of galvanic action is counselled. The reason for this difference is self-evident; here a foreign metal is brought into electrical contact with the apparatus in order that the latter may be made electro-negative; but when a joint is soldered with lead, the metal of the generator is unintentionally made electro-positive. Here the plant is protected by the preferential corrosion of a cheap and renewable rod; in the former case the plant is encouraged to rust by the unnecessary presence of an improperly selected metal. OTHER ITEMS IN GENERATING PLANT.--It has been explained in Chapter II. that the reaction between calcium carbide and water is very tumultuous in character, and that it occurs with great rapidity. Clearly, therefore, the gas comes away from the generator in rushes, passing into the next item of the plant at great speed for a time, and then ceasing altogether. The methods necessarily adopted for purifying the crude gas are treated of in Chapter V.; but it is manifest now that no purifying material can prove efficient unless the acetylene passes through it at a uniform rate, and at one which is as slow as other conditions permit. For this reason the proper position of the holder in an acetylene installation is before the purifier, and immediately after the condenser or washer which adjoins the generator. By this method of design the holder is filled up irregularly, the gas passing into it sometimes at full speed, sometimes at an imperceptible rate; but if the holder is well balanced and guided this is a matter of no consequence. Out of the holder, on the other hand, the gas issues at a rate which is dependent upon the number and capacity of the burners in operation at any moment; and in ordinary conditions this rate is so much more uniform during the whole of an evening than the rate at which the gas is evolved from the carbide, that a purifier placed after the holder is given a far better opportunity of extracting the impurities from the acetylene than it would have were it situated before the holder, as is invariably the case on coal-gas works. For many reasons, such as capacity for isolation when being recharged or repaired, it is highly desirable that each item in an acetylene plant shall be separated, or capable of separation, from its neighbours; and this observation applies with great force to the holder and the decomposing vessel of the generator. In all large plants each vessel should be fitted with a stopcock at its inlet and, if necessary, one at its outlet, being provided also with a by-pass so that it can be thrown out of action without interfering with the rest of the installation. In the best practice the more important vessels, such as the purifiers, will be in duplicate, so that unpurified gas need not be passed into the service while a solitary purifier is being charged afresh. In smaller plants, where less skilled labour will probably be bestowed on the apparatus, and where hand-worked cocks are likely to be neglected or misused, some more, automatic arrangement for isolating each item is desirable. There are two automatic devices which may be employed for the purposes in view, the non-return valve and the water-seal. The non-return valve is simply a mushroom or ball valve without handle, lifted off its seat by gas passing from underneath whenever the pressure of the gas exceeds the weight of the valve, but falling back on to its seat and closing the pipe when the pressure decreases or when pressure above is greater than that below. The apparatus works perfectly with a clean gas or liquid which is not corrosive; but having regard to the possible presence of tarry products, lime dust, or sludge, condensed water loaded with soluble impurities, &c., in the acetylene, a non-return valve is not the best device to adopt, for both it and the hand-worked cock or screw- down valve are liable to stick and give trouble. The best arrangement in all respects, especially between the generator and the holder, is a water-seal. A water-seal in made by leading the mouth of a pipe delivering gas under the level of water in a suitable receptacle, so that the issuing gas has to bubble through the liquid. Gas cannot pass backwards through the pipe until it has first driven so much liquid before it that the level in the seal has fallen below the pipe's mouth; and if the end of the pipe is vertical more pressure than can possibly be produced in the apparatus is necessary to effect this. Omitting the side tube _b_, one variety of water-seal is shown at D in Fig. 7 on page 103. The water being at the level _l_, gas enters at _a_ and bubbles through it, escaping from the apparatus at _c_. It cannot return from _c_ to _a_ without driving the water out of the vessel till its level falls from _f_ to _g_; and since the area of the vessel is much greater than that of the pipe, so great a fall in the vessel would involve a far greater rise in _a_. It is clear that such a device, besides acting as a non-return valve, also fulfils two other useful functions: it serves to collect and retain all the liquid matter that may be condensed in the pipe _a_ from the spot at which it was originally level or was given a fall to the seal, as well as that condensing in _c_ as far as the spot where _c_ dips again; and it equally acts as a washer to the gas, especially if the orifice _g_ of the gas-inlet pipe is not left with a plain mouth as represented in the figure, but terminates in a large number of small holes, the pipe being then preferably prolonged horizontally, with minute holes in it so as to distribute the gas throughout the entire vessel. Such an apparatus requires very little attention. It may with advantage be provided with the automatic arrangement for setting the water-level shown at _d_ and _e_. _d_ is a tunnel tube extending almost to the bottom of the vessel, and _e_ is a curved run-off pipe of the form shown. The lower part of the upper curve in _e_ is above the level _f_, being higher than _f_ by a distance equal to that of the gas pressure in the pipes; and therefore when water is poured into the funnel it fills the vessel till the internal level reaches _f_, when the surplus overflows of itself. The operation thus not only adjusts the quantity of water present to the desired level so that _a_ cannot become unsealed, but it also renews the liquid when it has become foul and nearly saturated with dissolved and condensed impurities from the acetylene. It would be a desirable refinement to give the bottom of the vessel a slope to the mouth of _e_, or to some other spot where a large-bore draw-off cock could be fitted for the purpose of extracting any sludge of lime, &c., that may collect. By having such a water-seal, or one simpler in construction, between the generator and the holder, the former may be safely opened at any time for repairs, inspection, or the insertion of a fresh charge of carbide while the holder is full of gas, and the delivery of acetylene to the burners at a specified pressure will not be interrupted. If a cock worked by hand were employed for the separation of the holder from the generator, and the attendant were to forget to close it, part or all of the acetylene in the holder would escape from the generator when it was opened or disconnected. Especially when a combined washer and non-return valve follows immediately after a generator belonging to the shoot type, and the mouth of the shoot is open to the air in the plant-house, it is highly desirable that the washer shall be fitted with some arrangement of an automatic kind for preventing the water level rising much above its proper position. The liquid in a closed washer tends to rise as the apparatus remains in use, water vapour being condensed within it and liquid water, or froth of lime, being mechanically carried forward by the stream of acetylene coming from the decomposing chamber. In course of time, therefore, the vertical depth to which the gas-inlet pipe in the washer is sealed by the liquid increases; and it may well be that eventually the depth in question, plus the pressure thrown by the holder bell, may become greater than the pressure which can be set up inside the generator without danger of gas slipping under the lower edge of the shoot. Should this state of things arise, the acetylene can no longer force its way through the washer into the holder bell, but will escape from the mouth of the shoot; filling the apparatus-house with gas, and offering every opportunity for an explosion if the attendant disobeys orders and takes a naked light with him to inspect the plant. It is indispensable that every acetylene apparatus shall be fitted with a safety-valve, or more correctly speaking a vent-pipe. The generator must have a vent-pipe in case the gas-main leading to the holder should become blocked at any time, and the acetylene which continues to be evolved in all water-to-carbide apparatus, even after the supply of water has been cut off be unable to pass away. Theoretically a non-automatic apparatus does not require a vent-pipe in its generator because all the gas enters the holder immediately, and is, or should be, unable to return through the intermediate water seal; practically such a safeguard is absolutely necessary for the reason given. The holder must have a safety-valve in case the cutting-off mechanism of the generator fails to act, and more gas passes into it than it can store. Manifestly the pressure of the gas in a water-sealed holder or in any generator fitted with a water-sealed lid cannot rise above that corresponding with the depth of water in the seal; for immediately the pressure, measured in inches of water, equals the depth of the sealing liquid, the seal will be blown out, and the gas will escape. Such an occurrence, however, as the blowing of a seal must never be possible in any item of an acetylene plant, more especially in those items that are under cover, for the danger that the issuing gas might be fired or might produce suffocation would be extremely great. Typical simple forms of vent-pipe suitable for acetylene apparatus are shown in Fig. 7. In each case the pipe marked "vent" is the so-called safety-valve; it is open at its base for the entry of gas, and open at its top for the escape of the acetylene into the atmosphere, such top being in all instances carried through the roof of the generator-house into the open air, and to a spot distant from any windows of that house or of the residence, where it can prove neither dangerous nor a nuisance by reason of its odour. At A is represented the vent-pipe of a displacement vessel, which may either be part of a displacement holder or of a generator working on the displacement principle. The vent-pipe is rigidly fixed to the apparatus. If gas is generated within the closed portion of the holder or passes through it, and if the pressure so set up remains less than that which is needed to move the water from the level _l_ to the levels _l'_ and _l"_, the mouth of the pipe is under water, and acetylene cannot enter it; but immediately such an amount of gas is collected, or such pressure is produced that the interior level sinks below _l"_, which is that of the mouth of the pipe, it becomes unsealed, and the surplus gas freely escapes. There are two minor points in connexion with this form of vent-pipe often overlooked. At the moment when the water arrives at _l"_ in the closed half of the apparatus, its level in the interior of the vent-pipe stands at _l'_, identical with that in the open hall of the apparatus (for the mouth of the vent-pipe and the water in the open hall of the apparatus are alike exposed to the pressure of the atmosphere only). When the water, then, descends just below _l"_ there is an amount of water inside the pipe equal in height to the distance between _l'_ and _l"_; and before the acetylene can escape, it must either force this water as a compact mass out of the upper mouth of the vent-pipe (which it is clearly not in a position to do), drive it out of the upper mouth a little at a time, or bubble through it till the water is gradually able to run downwards out of the pipe as its lower opening is more fully unsealed. In practice the acetylene partly bubbles through this water and partly drives it out of the mouth of the pipe; on some occasions temporarily yielding irregular pressures at the burners which cause them to jump, and always producing a gurgling noise in the vent- pipe which in calculated to alarm the attendant. If the pipe is too small in diameter, and especially if its lower orifice is cut off perfectly horizontal and constricted slightly, the water may refuse to escape from the bottom altogether, and the pipe will fail to perform its allotted task. It is better therefore to employ a wide tube, and to cut off its mouth obliquely, or to give its lower extremity the shape of an inverted funnel. At the half of the central divided drawing marked B (Fig. 7) is shown a precisely similar vent-pipe affixed to the bell of a rising holder, which behaves in an identical fashion when by the rising of the bell its lower end is lifted out of the water in the tank. The features described above as attendant, upon the act of unsealing of the displacement-holder vent-pipe occur here also, but to a less degree; for the water remaining in the pipe at the moment of unsealing is only that which corresponds with the vertical distance between _l'_ and _l"_, and in a rising holder this is only a height always equal to the pressure given by the bell. Nevertheless this form of vent-pipe produces a gurgling noise, and would be better for a trumpet-shaped mouth. A special feature of the pipe in B is that unless it is placed symmetrically about the centre of the bell its weight tends to throw the bell out of the vertical, and it may have to be supported at its upper part; conversely, if the pipe is arranged concentrically in the bell, it may be employed as part of the guiding arrangement of the bell itself. Manifestly, as the pipe must be long enough to extend through the roof of the generator-house, its weight materially increases the weight of the bell, and consequently the gas pressure in the service; this fact is not objectionable provided due allowance is made for it. So tall a vent-pipe, however, seriously raises the centre of gravity of the bell and may make it top-heavy. To work well the centre of gravity of a holder bell should be as low as possible, any necessary weighting being provided symmetrically about its circumference and close to its bottom edge. The whole length of an ascending vent-pipe need not be carried by the rising bell, because the lower portion, which must be supported by the bell, can be arranged to slide inside a wider length of pipe which is fixed to the roof of the generator-house at the point where it passes into the open air. [Illustration: FIG. 7.--TYPICAL FORMS OF VENT-PIPES OR SAFETY-VALVES.] A refinement upon this vent-pipe is represented at C, where it is rigidly fastened to the tank of the holder, and has its internal aperture always above the level of the water in the apparatus. Rigidly fixed to the crown of the bell is a tube of wider diameter, _h_, which is closed at its upper end. _h_ is always full of gas, and its mouth is normally beneath the level of the water in the seal; but when the bell rises to its highest permissible position, the mouth of _h_ comes above the water, and communication is opened between the holder and the outer atmosphere. No water enters the vent-pipe from the holder, and therefore no gurgling or irregular pressure is produced. Another excellent arrangement of a vent-pipe, suggested by Klinger of Gumpoldskirchen, is shown at D, a drawing which has already been partly considered as a washer and water-seal. For the present purpose the main vessel and its various pipes are so dimensioned that the vertical height _g_ to _f_ is always appreciably greater than the gas pressure in the service or in the generator or gasholder to which it is connected. In these circumstances the gas entering at _a_ depresses the water in the pipe below the level _f_ to an extent equal to the pressure at which it enters that pipe--an extent normally less than the distance _f_ to _g_; and therefore gas never passes into the body of the vessel, but travels away by the side tube _b_ (which in former references to this drawing was supposed to be absent). If, however, the pressure at _a_ exceeds that of the vertical height _f_ to _g_, gas escapes at _g_ through the water, and is then free to reach the atmosphere by means of the vent _c_. As before, _d_ serves to charge the apparatus with water, and _e_ to ensure a proper amount being added. Clearly no liquid can enter the vent-pipe in this device. Safety-valves such as are added to steam-boilers and the like, which consist of a weighted lever holding a conical valve down against its seat, are not required in acetylene apparatus, for the simpler hydraulic seals discussed above can always be fitted wherever they may be needed. It should be noticed that these vent-pipes only come into operation in emergencies, when they are required to act promptly. No economy is to be effected by making them small in diameter. For obvious reasons the vent-pipe of a holder should have a diameter equal to that of the gas-inlet tube, and the vent-pipe of a generator be equal in size to the gas-leading tube. FROTHING IN GENERATORS.--A very annoying trouble which crops up every now and then during the evolution of acetylene consists in the production of large masses of froth within the generator. In the ordinary way, decomposition of carbide is accompanied by a species of effervescence, but the bubbles should break smartly and leave the surface of the liquid reasonably free from foam. Sometimes, however, the bubbles do not break, but a persistent "head" of considerable height is formed. Further production of gas only increases the thickness of the froth until it rises so high that it is carried forward through the gas-main into the next item of the plant. The froth disappears gradually in the pipes, but leaves in them a deposit of lime which sooner or later causes obstructions by accumulating at the angles and dips; while during its presence in the main the steady passage of gas to the holder is interrupted and the burners may even be made to jump. Manifestly the defect is chiefly, if not always, to be noticed in the working of carbide-to-water generators. The phenomenon has been examined by Mauricheau-Beaupré, who finds that frothing is not characteristic of pure carbide and that it cannot be attributed to any of the impurities normally present in commercial carbide. If, however, the carbide contains calcium chloride, frothing is liable to occur. A 0.1 per cent. solution of calcium chloride appears to yield some foam when carbide is decomposed in it, and a 1 per cent. solution to foam in a pronounced manner. In the absence of calcium chloride, the main cause of frothing seems to be the presence in the generator of new paint or tar. If a generator is taken into use before the paint in any part of it which becomes moistened by warm lime-water has had opportunity of drying thoroughly hard, frothing is certain to occur; and even if the carbide has been stored for only a short time in a tin or drum which has been freshly painted, a production of froth will follow when it is decomposed in water. The products of the polymerisation of acetylene also tend to produce frothing, but not to such an extent as the turpentine in paint and the lighter constituents of coal-tar. Carbide stored even temporarily in a newly painted tin froths on decomposition because it has absorbed among its pores some of the volatile matter given off by the paint during the process of desiccation. THE "DRY" PROCESS OF GENERATION.--A process for generating acetylene, totally different in principle from those hitherto considered, has been introduced in this country. According to the original patents of G. J. Atkins, the process consisted in bringing small or powdered carbide into mechanical contact with some solid material containing water, the water being either mixed with the solid reagent or attached to it as water of crystallisation. Such reagents indeed were claimed as crude starch and the like, the idea being to recover a by-product of pecuniary value. Now the process seems to be known only in that particular form in which granulated carbide is treated with crystallised sodium carbonate, _i.e._, common washing soda. Assuming the carbide employed to be chemically pure and the reaction between it and the water of crystallisation contained in ordinary soda crystals to proceed quantitatively, the production of acetylene by the dry process should be represented by the following chemical equation: 5CaC_2 + Na_2CO_3.10H_2O = 5C_2H_2 + 5Ca(OH)_2 + Na_2CO_3. On calculating out the molecular weights, it will be seen that 286 parts of washing soda should suffice for the decomposition of 320 parts of pure calcium carbide, or in round numbers 9 parts of soda should decompose 10 parts of carbide. In practice, however, it seems to be found that from 1 to 1.5 parts of soda are needed for every part of carbide. The apparatus employed is a metal drum supported on a hollow horizontal spindle, one end of which is closed and carries a winch handle, and the other end of which serves to withdraw the gas generated in the plant. The drum is divided into three compartments by means of two vertical partitions so designed that when rotation proceeds in one particular direction portions of the two reagents stored in one end compartment pass into the centre compartment; whereas when rotation proceeds in the opposite direction, the material in the centre compartment is merely mixed together, partly by the revolution of the drum, partly with the assistance of a stationary agitator slung loosely from the central spindle. The other end compartment contains coke or sawdust or other dry material through which the gas passes for the removal of lime or other dust carried in suspension as it issues from the generating compartment. The gas then passes through perforations into the central spindle, one end of which is connected by a packed joint with a fixed pipe, which leads to a seal or washer containing petroleum. Approached from a theoretical standpoint, it will be seen that this method of generation entirely sacrifices the advantages otherwise accruing from the use of liquid water as a means for dissipating the heat of the chemical reaction, but on the other hand, inasmuch as the substances are both solid, the reaction presumably occurs more slowly than it would in the presence of liquid water; and moreover the fact that the water employed to act upon the carbide is in the solid state and also more or less combined with the rest of the sodium carbonate molecule, means that, per unit of weight, the water decomposed must render latent a larger amount of heat than it would were it liquid. Experiments made by one of the authors of this book tend to show that the gas evolved from carbide by the dry process contains rather less phosphorus than it might in other conditions of generation, and as a fact gas made by the dry process is ordinarily consumed without previous passage through any chemical purifying agent. It is obvious, however, that the use of the churn described above greatly increases the labour attached to the production of the gas; while it is not clear that the yield per unit weight of carbide decomposed should be as high as that obtained in wet generation. The inventor has claimed that his by-product should be valuable and saleable, apparently partly on the ground that it should contain caustic soda. Evidence, however, that a reaction between the calcium oxide or hydroxide and the sodium carbonate takes place in the prevailing conditions is not yet forthcoming, and the probabilities are that such decomposition would not occur unless the residue were largely diluted with water. [Footnote: The oldest process employed for manufacturing caustic soda consisted in mixing a solution of sodium carbonate with quick or slaked lime, and it has been well established that the causticisation of the soda will not proceed when the concentration of the liquid is greater than that corresponding with a specific gravity of about 1-10, _i.e._, when the liquid contains more than some 8 to 10 per cent, of sodium hydroxide.] Conversely there are some grounds for believing that the dry residue is less useful than an ordinary wet residue for horticultural purposes, and also for the production of whitewash. From a financial standpoint, the dry process suffers owing to the expense involved in the purchase of a second raw material, for which but little compensation can be discovered unless it is proved that the residue is intrinsically more valuable than common acetylene-lime and can be sold or used advantageously by the ordinary owner of an installation. The discarding of the chemical purifier at the present day is a move of which the advantage may well be overrated. ARTIFICIAL LIGHTING OF GENERATOR SHEDS.--It has already been argued that all normal or abnormal operations in connexion with an acetylene generating plant should be carried out, if possible, by daylight; and it has been shown that on no account must a naked light ever be taken inside the house containing such a plant. It will occasionally happen, however, that the installation must be recharged or inspected after nightfall. In order to do this in safety, a double window, incapable of being opened, should be fitted in one wall of the house, as far as possible from the door, and in such a position that the light may fall on to all the necessary places. Outside this window may be suspended an ordinary hand- lantern burning oil or paraffin; or, preferably, round this window may be built a closed lantern into which some source of artificial light may be brought. If the acetylene plant has an isolated holder of considerable size, there is no reason at all why a connexion should not be made with the service-pipes, and an acetylene flame be used inside this lantern; but with generators of the automatic variety, an acetylene light is not so suitable, because of the fear that gas may not be available precisely at the moment when it is necessary to have light in the shed. It would, however, be a simple matter to erect an acetylene burner inside the lantern in such a way that when needed an oil-lamp or candle could be used instead. Artificial internal light of any kind is best avoided; the only kind permissible being an electric glow-lamp. If this is employed, it should be surrounded by a second bulb or gas-tight glass jacket, and preferably by a wire cage as well; the wires leading to it must be carefully insulated, and all switches or cut-outs (which may produce a spark) must be out of doors. The well-known Davy safety or miner's lamp is not a trustworthy instrument for use with acetylene because of (_a_) the low igniting-point of acetylene; (_b_) the high temperature of its flame; and (_c_) the enormous speed at which the explosive wave travels through a mixture of acetylene and air. For these reasons the metallic gauze of the Davy lamp is not so efficient a protector of the flame as it is in cases of coal-gas, methane, &c. Moreover, in practice, the Davy lamp gives a poor light, and unless in constant use is liable to be found out of order when required. It should, however, be added that modern forms of the safety lamp, in which the light is surrounded by a stout glass chimney and only sufficient gauze is used for the admission of fresh air and for the escape of the combustion products, appear quite satisfactory when employed in an atmosphere containing some free acetylene. CHAPTER IV THE SELECTION OF AN ACETYLENE GENERATOR In Chapter II. an attempt has been made to explain the physical and chemical phenomena which accompany the interaction of calcium carbide and water, and to show what features in the reaction are useful and what inconvenient in the evolution of acetylene on a domestic or larger scale. Similarly in Chapter III. have been described the various typical devices which may be employed in the construction of different portions of acetylene plant, so that the gas may be generated and stored under the best conditions, whether it is evolved by the automatic or by the non- automatic system. This having been done, it seemed of doubtful utility to include in the first edition of this work a long series of illustrations of such generators as had been placed on the markets by British, French, German, and American makers. It would have been difficult within reasonable limits to have reproduced diagrams of all the generators that had been offered for sale, and absolutely impossible within the limits of a single hand-book to picture those which had been suggested or patented. Moreover, some generating apparatus appeared on the market ephemerally; some was constantly being modified in detail so as to alter parts which experience or greater knowledge had shown the makers to be in need of alteration, while other new apparatus was constantly being brought out. On these and other grounds it did not appear that much good purpose would have been served by describing the particular apparatus which at that time would have been offered to prospective purchasers. It seemed best that the latter should estimate the value and trustworthiness of apparatus by studying a section of it in the light of the general principles of construction of a satisfactory generator as enunciated in the book. While the position thus taken by the authors in 1903 would still not be incorrect, it has been represented to them that it would scarcely be inconsistent with it to give brief descriptions of some of the generators which are now being sold in Great Britain and a few other countries. Six more years' experience in the design and manufacture of acetylene plant has enabled the older firms of manufacturers to fix upon certain standard patterns for their apparatus, and it may confidently be anticipated that many of these will survive a longer period. Faulty devices and designs have been weeded out, and there are lessons of the past as well as theoretical considerations to guide the inventor of a new type of generator. On those grounds, therefore, an attempt has now been made to give brief descriptions, with sectional views, of a number of the generators now on the market in Great Britain. Moreover, as the first edition of this book found many readers in other countries, in several of which there is greater scope for the use of acetylene, it has been decided to describe also a few typical or widely used foreign generators. All the generators described must stand or fall on their merits, which cannot be affected by any opinion expressed by the authors. In the descriptions, which in the first instance have generally been furnished by the manufacturers of the apparatus, no attempt has therefore been made to appraise the particular generators, and comparisons and eulogistic comments have been excluded. The descriptions, however, would nevertheless have been somewhat out of place in the body of this book; they have therefore been relegated to a special Appendix. It has, of course, been impossible to include the generators of all even of the English manufacturers, and doubtless many trustworthy ones have remained unnoticed. Many firms also make other types of generators in addition to those described. It must not be assumed that because a particular make of generator is not mentioned it is necessarily faulty. The apparatus described may be regarded as typical or well known, and workable, but it is not by reason of its inclusion vouched for in any other respect by the authors. The Appendix is intended, not to bias or modify the judgment of the would-be purchaser of a generator, but merely to assist him in ascertaining what generators there are now on the market. The observations on the selection of a generator which follow, as well as any references in other chapters to the same matter, have been made without regard to particular apparatus of which a description may (or may not) appear in the Appendix. With this premise, it may be stated that the intending purchaser should regard the mechanism of a generator as shown in a sectional view or on inspection of the apparatus itself. If the generator is simple in construction, he should be able to understand its method of working at a glance, and by referring it to the type (_vide_ Chapter III.) to which it belongs, be able to appraise its utility from a chemical and physical aspect from what has already been said. If the generator is too complicated for ready understanding of its mode of working, it is not unlikely to prove too complicated to behave well in practice. Not less important than the mechanism of a generator is good construction from the mechanical point of view, _i.e._, whether stout metal has been employed, whether the seams and joints are well finished, and whether the whole apparatus has been built in the workman- like fashion which alone can give satisfaction in any kind of plant. Bearing these points in mind, the intending purchaser may find assistance in estimating the mechanical value of an apparatus by perusing the remainder of this chapter, which will be devoted to elaborating at length the so-called scientific principles underlying the construction of a satisfactory generator, and to giving information on the mechanical and practical points involved. It is perhaps desirable to remark that there is scarcely any feature in the generation of acetylene from calcium carbide and water--certainly no important feature--which introduces into practice principles not already known to chemists and engineers. Once the gas is set free it ranks simply as an inflammable, moisture-laden, somewhat impure, illuminating and heat-giving gas, which has to be dried, purified, stored, and led to the place of combustion; it is in this respect precisely analogous to coal- gas. Even the actual generation is only an exothermic, or heat-producing, reaction between a solid and a liquid, in which rise of temperature and pressure must be prevented as far as possible. Accordingly there is no fundamental or indispensable portion of an acetylene apparatus which lends itself to the protection of the patent laws; and even the details (it may be said truthfully, if somewhat cynically) stand in patentability in inverse ratio to their simplicity and utility. During the early part of 1901 a Committee appointed by the British Home Office, "to advise as to the conditions of safety to which acetylene generators should conform, and to carry out tests of generators in the market in order to ascertain how far those conform with such conditions," issued a circular to the trade suggesting that apparatus should be sent them for examination. In response, forty-six British generators were submitted for trial, and were examined in a fashion which somewhat exceeded the instructions given to the Committee, who finally reported to the Explosives Department of the Home Office in a Blue Book, No. Cd. 952, which can be purchased through any bookseller. This report comprises an appendix in which most of the apparatus are illustrated, and it includes the result of the particular test which the Committee decided to apply. Qualitatively the test was useful, as it was identical in all instances, and only lacks full utility inasmuch as the trustworthiness of the automatic mechanism applied to such generators as were intended to work on the automatic system was not estimated. Naturally, a complete valuation of the efficiency of automatic mechanism cannot be obtained from one or even several tests, it demands long-continued watching; but a general notion of reliability might have been obtained. Quantitatively, however, the test applied by the Committee is not so free from reproach, for, from the information given, it would appear to have been less fair to some makers of apparatus than to others. Nevertheless the report is valuable, and indicates the general character of the most important apparatus which were being offered for sale in the United Kingdom in 1900-1901. It is not possible to give a direct answer to the question as to which is the best type of acetylene generator. There are no generators made by responsible firms at the present time which are not safe. Some may be easier to charge and clean than others; some require more frequent attention than others; some have moving parts less likely to fail, when handled carelessly, than others; some have no moving mechanism to fail. For the illumination of a large institution or district where one man can be fully occupied in attending to the plant, cleaning, lighting, and extinguishing the lamps, or where other work can be found for him so as to leave him an hour or so every day to look after the apparatus, the hand-fed carbide-to-water generator L (Fig. 6) has many advantages, and is probably the best of all. In smaller installations choice must be made first between the automatic and the non-automatic principle--the advantages most frequently lying with the latter. If a non-automatic generator is decided upon, the hand carbide-feed or the flooded- compartment apparatus is almost equally good; and if automatism is desired, either a flooded-compartment machine or one of the most trustworthy types of carbide-feed apparatus may be taken. There are contact apparatus on the markets which appear never to have given trouble, and those are worthy of attention. Some builders advocate their own apparatus because the residue is solid and not a cream. If there is any advantage in this arising from greater ease in cleaning and recharging the generator and in disposing of the waste, that advantage is usually neutralised by the fear that the carbide may not have been wholly decomposed within the apparatus; and whereas any danger arising from imperfectly spent carbide being thrown into a closed drain may be prevented by flooding the residue with plenty of water in an open vessel, imperfect decomposition in the generator means a deficiency in the amount of gas evolved from a unit weight of solid taken or purchased. In fact, setting on one side apparatus which belong to a notoriously defective system and such as are constructed in large sizes on a system that is only free from overheating, &c., in small sizes; setting aside all generators which are provided with only one decomposing chamber when they are of a capacity to require two or more smaller ones that can more efficiently be cooled with water jackets; and setting aside any form of plant which on examination is likely to exhibit any of the more serious objections indicated in this and the previous chapters, there is comparatively little to choose, from the chemical and physical points of view, between the different types of generators now on the markets. A selection may rather be made on mechanical grounds. The generator must be well able to produce gas as rapidly as it will ever be required during the longest or coldest evening; it must be so large that several more brackets or burners can be added to the service after the installation is complete. It must be so strong that it will bear careless handling and the frequent rough manipulation of its parts. It must be built of stout enough material not to rust out in a few years. Each and all of its parts must be accessible and its exterior visible. Its pipes, both for gas and sludge, must be of large bore (say 1 inch), and fitted at every dip with an arrangement for withdrawing into some closed vessel the moisture, &c., that may condense. The number of cocks, valves, and moving parts must be reduced to a minimum; cocks which require to be shut by hand before recharging must give way to water-seals. It must be simple in all its parts, and its action intelligible at a glance. It must be easy to charge--preferably even by the sense of touch in darkness. It must be easy to clean. The waste lime must be easily removed. It must be so fitted with vent-pipes that the pressure can never rise above that at which it is supposed to work. Nevertheless, a generator in which these vent-pipes are often brought into use is badly constructed and wasteful, and must be avoided. The water of the holder seal should be distinct from that used for decomposing the carbide; and those apparatus where the holder is entirely separated from the generator are preferable to such as are built all in one, even if water-seals are fitted to prevent return of gas. Apparatus which is supposed to be automatic should be made perfectly automatic, the water or the carbide-feed being locked automatically before the carbide store, the decomposing chamber, or the sludge-cock can be opened. The generating chamber must always be in communication with the atmosphere through a water-sealed vent-pipe, the seal of which, if necessary, the gas can blow at any time. All apparatus should be fitted with rising holders, the larger the better. Duplicate copies of printed instructions should be demanded of the maker, one copy being kept in the generator-house, and the other elsewhere for reference in emergencies. These instructions must give simple and precise information as to what should be done in the event of a breakdown as well as in the normal manipulation of the plant. Technical expressions and descriptions of parts understood only by the maker must be absent from these rules. ADDENDUM. BRITISH AND FOREIGN REGULATIONS FOR THE CONSTRUCTION AND INSTALLATION OF ACETYLENE GENERATING PLANT Dealing with the "conditions which a generator should fulfil before it can be considered as being safe," the HOME OFFICE COMMITTEE of 1901 before mentioned write as follows: 1. The temperature in any part of the generator, when run at the maximum rate for which it is designed, for a prolonged period, should not exceed 130° C. This may be ascertained by placing short lengths of wire, drawn from fusible metal, in those parts of the apparatus in which heat is liable to be generated. 2. The generator should have an efficiency of not less than 90 per cent., which, with carbide yielding 5 cubic feet per pound, would imply a yield of 4.5 cubic feet for each pound of carbide used. 3. The size of the pipes carrying the gas should be proportioned to the maximum rate of generation, so that undue back pressure from throttling may not occur. 4. The carbide should be completely decomposed in the apparatus, so that lime sludge discharged from the generator shall not be capable of generating more gas. 5. The pressure in any part of the apparatus, on the generator side of the holder, should not exceed that of 20 inches of water, and on the service side of same, or where no gasholder is provided, should not exceed that of 5 inches of water. 6. The apparatus should give no tarry or other heavy condensation products from the decomposition of the carbide. 7. In the use of a generator regard should be had to the danger of stoppage of passage of the gas and resulting increase of pressure which may arise from the freezing of the water. Where freezing may be anticipated, steps should be taken to prevent it. 8. The apparatus should be so constructed that no lime sludge can gain access to any pipes intended for the passage of gas or circulation of water. 9. The use of glass gauges should be avoided as far as possible, and, where absolutely necessary, they should be effectively protected against breakage. 10. The air space in a generator before charging should be as small as possible. 11. The use of copper should be avoided in such parts of the apparatus as are liable to come in contact with acetylene. The BRITISH ACETYLENE ASSOCIATION has drawn up the following list of regulations which, it suggests, shall govern the construction of generators and the installation of piping and fittings: 1. Generators shall be so constructed that, when used in accordance with printed instructions, it shall not be possible for any undecomposed carbide to remain in the sludge removed therefrom. 2. The limit of pressure in any part of the generator shall not exceed that of 20 inches of water, subject to the exception that if it be shown to the satisfaction of the Executive of the Acetylene Association that higher pressures up to 50 inches of water are necessary in certain generators, and are without danger, the Executive may, with the approval of the Home Office, grant exemption for such generators, with or without conditions. 3. The limit of pressure in service-pipes, within the house, shall not exceed 10 inches of water. 4. Except when used for special industrial purposes, such as oxy- acetylene welding, factories, lighthouses, portable apparatus containing not more than four pounds of carbide, and other special conditions as approved by the Association, the acetylene plant, such as generators, storage-holders, purifiers, scrubbers, and for washers, shall be in a suitable and well-ventilated outhouse, in the open, or in a lean-to, having no direct communication with a dwelling-house. A blow-off pipe or safety outlet shall be arranged in such a manner as to carry off into the open air any overmake of gas and to open automatically if pressure be increased beyond 20 inches water column in the generating chamber or beyond 10 inches in the gasholder, or beyond the depth of any fluid seal on the apparatus. 5. Generators shall have sufficient storage capacity to make a serious blow-off impossible. 6. Generators and apparatus shall be made of sufficiently strong material and be of good workmanship, and shall not in any part be constructed of unalloyed copper. 7. It shall not be possible under any conditions, even by wrong manipulation of cocks, to seal the generating chamber hermetically. 8. It shall not be possible for the lime sludge to choke any of the gas- pipes in the apparatus, nor water-pipes if such be alternately used as safety-valves. 9. In the use of a generator, regard shall be had to the danger of stoppage of passage of the gas, and resulting increase of pressure, which may arise from the freezing of the water. Where freezing may be anticipated, steps shall be taken to prevent it. 10. The use of glass gauges shall be avoided as far as possible, and where absolutely necessary they shall be effectively protected against breakage. 11. The air space in the generator before charging shall be as small as possible, _i.e._, the gas in the generating chamber shall not contain more than 8 per cent. of air half a minute after commencement of generation. A sample of the contents, drawn from the holder any time after generation has commenced, shall not contain an explosive mixture, _i.e._, more than 18 per cent, of air. This shall not apply to the initial charges of the gasholder, when reasonable precautions are taken. 12. The apparatus shall produce no tarry or other heavy condensation products from the decomposition of the carbide. 13. The temperature of the gas, immediately on leaving the charge, shall not exceed 212° F. (100° C.) 14. No generator shall be sold without a card of instructions suitable for hanging up in some convenient place. Such instructions shall be of the most detailed nature, and shall not presuppose any expert knowledge whatever on the part of the operator. 15. Notice to be fixed on Generator House Door, "NO LIGHTS OR SMOKING ALLOWED." 16. Every generator shall have marked clearly upon the outside a statement of the maximum number of half cubic foot burners and the charge of carbide for which it is designed. 17. The Association strongly advise the use of an efficient purifier with generating plant for indoor lighting. 18. No composition piping shall be used in any part of a permanent installation. 19. Before being covered in, all pipe-work (main and branches) shall be tested in the following manner: A special acetylene generator, giving a pressure of at least 10 inches water column in a gauge fixed on the furthest point from the generator, shall be connected to the pipe-work. All points shall be opened until gas reaches them, when they shall be plugged and the main cock on the permanent generator turned off, but all intermediate main cocks shall be open in order to test underground main and all connexions. The gauge must not show a loss after generator has been turned off for at least two hours. 20. After the fittings (pendants, brackets, &c.) have been fixed and all burners lighted, the gas shall be turned off at the burners and the whole installation shall be re-tested, but a pressure of 5 inches shall be deemed sufficient, which shall not drop lower than to 4-1/2 inches on the gauge during one hour's test. 21. No repairs to, or alterations in, any part of a generator, purifier, or other vessel which has contained acetylene shall be commenced, nor, except for recharging, shall any such part or vessel be cleaned out until it has been completely filled with water, so as to expel any acetylene or mixture of acetylene and air which may remain in the vessel, and may cause a risk of explosion. _Recommendation_.--It being the general practice to store carbide in the generator-house, the Association recommend that the carbide shall be placed on a slightly raised platform above the floor level. THE BRITISH FIRE OFFICES COMMITTEE in the latest revision, dated July 15, 1907, of its Rules and Regulations _re_ artificial lighting on insured premises, includes the following stipulations applicable to acetylene: Any apparatus, except as below, for generating, purifying, enriching, compressing or storing gas, must be either in the open or in a building used for such purposes only, not communicating directly with any building otherwise occupied. An acetylene portable apparatus is allowed, provided it holds a charge of not more than 2 lb. of carbide. A cylinder containing not more than 20 cubic feet of acetylene compressed and (or) dissolved in accordance with an Order of Secretary of State under the Explosives Act, 1875, is allowed. The use of portable acetylene lamps containing charges of carbide exceeding the limit of 2 lb. allowed under these Rules (the average charge being about 18 lb.) is allowed in the open or in buildings in course of erection. Liquid acetylene must not be used or stored on the premises. The pipe, whether flexible or not, connecting an incandescent gas lamp to the gas-supply must be of metal with metal connexions. (The reference in these Rules to the storage of carbide has been quoted in Chapter II. (page 19).) These rules are liable to revision from time to time. The GERMAN ACETYLENE VEREIN has drawn up (December 1904) the following code of rules for the construction, erection, and manipulation of acetylene apparatus: I. _Rules for Construction._ 1. All apparatus for the generation, purification, and storage of acetylene must be constructed of sheet or cast iron. Holder tanks may be built of brick. 2. When bare, galvanised, or lead-coated sheet-iron is used, the sides of generators, purifiers, condensers, holder tanks, and (if present) washers and driers must be built with the following gauges as minima: Holder bells. All other apparatus. Up to 7 cubic feet capacity 0.75 mm. 1.00 mm. From 7 to 18 " 1.00 1.25 From 18 to 53 " 1.25 1.50 Above 53 " 1.50 2.00 When not constructed of cast-iron, the bottoms, covers, and "manhole" lids must be 0.5 mm. thicker in each respective size. In all circumstances, the thickness of the walls--especially in the case of apparatus not circular in horizontal section--must be such that alteration in shape appears impossible, unless deformation is guarded against in other ways. Generators must be so constructed that when they are being charged the carbide cannot fall into the residue which has already been gasified; and the residues must always be capable of easy, complete, and safe removal. 3. Generators, purifiers, and holders must be welded, riveted or folded at the seams; soft solder is only permissible as a tightening material. 4. Pipes delivering acetylene, or uniting the apparatus, must be cast- or wrought-iron. Unions, cocks, and valves must not be made of copper; but the use of brass and bronze is permitted. 5. When cast-iron is employed, the rules of the German Gas and Water Engineers are to be followed. 6. In generators where the whole amount of carbide introduced is not gasified at one time, it must be possible to add fresh water or carbide in safety, without interfering with the action of the apparatus. In such generators the size of the gasholder space is to be calculated according to the quantity of carbide which can be put into the generator. For every 1 kilogramme of carbide the available gasholder space must be: for the first 50 kilos., 20 litres; for the next 50 kilos., 15 litres; for amounts above 100 kilos., 10 litres per kilo. [One kilogramme may be taken as 2.2 lb., and 28 litres as 1 cubic foot.] The generator must be large enough to supply the full number of normal (10-litre) burners with gas for 5 hours; the yield of acetylene being taken at 290 litres per kilo. [4.65 cubic feet per lb.] The gasholder space of apparatus where carbide is not stored must be at least 30 litres for every normal (10-litre) flame. 7. The gasholder must be fitted with an appliance for removing any gas which may be generated (especially when the apparatus is first brought into action) after the available space is full. This vent must have a diameter at least equal to the inlet pipe of the holder. 8. Acetylene plant must be provided with purifying apparatus which contains a proper purifying material in a suitable condition. 9. The dimensions of subsidiary apparatus, such as washers, purifiers, condensers, pipes, and cocks must correspond with the capacity of the plant. 10. Purifiers and washers must be constructed of materials capable of resisting the attack of the substances in them. 11. Every generator must bear a plate giving the name of the maker, or the seller, and the maximum number of l0-litre lights it is intended to supply. If all the carbide put into the generator is not gasified at one time, the plate must also state the maximum weight of carbide in the charge. The gasholder must also bear a plate recording the maker's or seller's name, as well as its storage capacity. 12. Rules 1 to 11 do not apply to portable apparatus serving up to two lights, or to portable apparatus used only out of doors for the lighting of vehicles or open spaces. II. _Rules for Erection_ 1. Acetylene apparatus must not be erected in or under rooms occupied or frequented (passages, covered courts, &c.) by human beings. Generators and holders must only be erected in apartments covered with light roofs, and separated from occupied rooms, barns, and stables by a fire-proof wall, or by a distance of 15 feet. Any wall is to be considered fire- proof which is built of solid brick, without openings, and one side of which is "quite free." Apparatus may be erected in barns and stables, provided the space required is partitioned off from the remainder by a fire-proof wall. 2. The doors of apparatus sheds must open outwards, and must not communicate directly with rooms where fires and artificial lights are used. 3. Apparatus for the illumination of showmen's booths, "merry-go-rounds," shooting galleries, and the like must be erected outside the tents, and be inaccessible to the public. 4. Permanent apparatus erected in the open air must be at least 15 feet from an occupied building. 5. Apparatus sheds must be fitted at their highest points with outlet ventilators of sufficient size; the ventilators leading straight through the roof into the open air. They must be so arranged that the escaping gases and vapours cannot enter rooms or chimneys. 6. The contacts of any electrical warning devices must be outside the apparatus shed. 7. Acetylene plants must be prevented from freezing by erection in frost- free rooms, or by the employment of a heating apparatus or other suitable appliance. The heat must only be that of warm water or steam. Furnaces for the heating appliance must be outside the rooms containing generators, their subsidiary apparatus, or holders; and must be separated from such rooms by fire-proof walls. 8. In one of the walls of the apparatus shed--if possible not that having a door--a window must be fitted which cannot be opened; and outside that window an artificial light is to be placed. In the usual way acetylene lighting may be employed; but a lamp burning paraffin or oil, or a lantern enclosing a candle, must always be kept ready for use in emergencies. In all circumstances internal lighting is forbidden. 9. Every acetylene installation must be provided with a main cock, placed in a conveniently accessible position so that the whole of the service may be cut off from the plant. 10. The seller of an apparatus must provide his customer with a sectional drawing, a description of the apparatus, and a set of rules for attending to it. These are to be supplied in duplicate, and one set is to be kept hanging up in the apparatus shed. III. Rules for Working the Apparatus. 1. The apparatus must only be opened by daylight for addition of water. If the generator is one of those in which the entire charge of carbide is not gasified at once, addition of fresh carbide must only be made by daylight. 2. All work required by the plant, or by any portion of it, and all ordinary attendance needed must be performed by daylight. 3. All water-seals must be carefully kept full. 4. When any part of an acetylene apparatus or a gas-meter freezes, notwithstanding the precautions specified in II., 7, it must be thawed only by pouring hot water into or over it; flames, burning fuel, or red- hot iron bars must not be used. 5. Alterations to any part of an apparatus which involve the operations of soldering or riveting, &c., _i.e._, in which a fire must be used, or a spark may be produced by the impact of hammer on metal, must only be carried out by daylight in the open air after the apparatus has been taken to pieces. First of all the plant must be freed from gas. This is to be done by filling every part with water till the liquid overflows, leaving the water in it for at least five minutes before emptying it again. 6. The apparatus house must not be used for any other operation, nor employed for the storage of combustible articles. It must be efficiently ventilated, and always kept closed. A notice must be put upon the door that unauthorised persons are not permitted to enter. 7. It in forbidden to enter the house with a burning lantern or lamp, to strike matches, or to smoke therein. 8. A search for leaks in the pipes must not be made with the aid of a light. 9. Alterations to the service must not be made while the pipes are under pressure, but only after the main cock has been shut. 10. If portable apparatus, such as described in I., 12, are connected to the burners with rubber tube, the tube must be fortified with an internal or external spiral of wire. The tube must be fastened at both ends to the cocks with thread, copper wire, or with ring clamps. 11. The preparation, storage, and use of compressed or liquefied acetylene is forbidden. By compressed acetylene, however, is only to be understood gas compressed to a pressure exceeding one effective atmosphere. Acetylene compressed into porous matter, with or without acetone, is excepted from this prohibition. 12. In the case of plants serving 50 lights or less, not more than 100 kilos. of carbide in closed vessels may be kept in the apparatus house besides the drum actually in use. A fresh drum is not to be opened before the previous one has been two- thirds emptied. Opened drums must be closed with an iron watertight lid covering the entire top of the vessel. In the case of apparatus supplying over 500 lights, only one day's consumption of carbide must be kept in the generator house. In other respects the store of carbide for such installations is to be treated as a regular carbide store. 13. Carbide drums must not be opened with the aid of a flame or a red-hot iron instrument. 14. Acetylene apparatus must only be attended to by trustworthy and responsible persons. The rules issued by the AUSTRIAN GOVERNMENT in 1905 for the installation of acetylene plant and the use of acetylene are divided into general enactments relating to acetylene, and into special enactments in regard to the apparatus and installation. The general enactments state that: 1. The preparation and use of liquid acetylene is forbidden. 2. Gaseous acetylene, alone, in admixture, or in solution, must not be compressed above 2 atmospheres absolute except under special permission. 3. The storage of mixtures of acetylene with air or other gases containing or evolving free oxygen is forbidden. 4. A description of every private plant about to be installed must be submitted to the local authorities, who, according to its size and character, may give permission for it to be installed and brought into use either forthwith or after special inspection. Important alterations to existing plant must be similarly notified. 5. The firms and fitters undertaking the installation of acetylene plant must be licensed. The special enactments fall under four headings, viz., (_a_) apparatus; (_b_) plant houses; (_c_) pipes; (_d_) residues. In regard to apparatus it is enacted that: 1. The type of apparatus to be employed must be one which has been approved by one of certain public authorities in the country. 2. A drawing and description of the construction of the apparatus and a short explanation of the method of working it must be fixed in a conspicuous position under cover in the apparatus house. The notice must also contain approved general information as to the properties of calcium carbide and acetylene, precautions that must be observed to guard against possible danger, and a statement of how often the purifier will require to be recharged. 3. The apparatus must be marked with the name of the maker, the year of its construction, the available capacity of the gasholder, and the maximum generating capacity per hour. 4. Each constituent of the plant must be proportioned to the maximum hourly output of gas and in particular the available capacity of the holder must be 75 per cent. of the latter. The apparatus must not be driven above its nominal productive capacity. 5. The productive capacity of generators in which the gasholder has to be opened or the bell removed before recharging, or for the removal of sludge, must not exceed 50 litres per hour, nor may the charge of carbide exceed 1 kilo. 6. Generators exceeding 50 litres per hour productive capacity must be arranged so that they can be freed from air before use. 7. Generators exceeding 1500 litres per hour capacity must be arranged so that the acetylene, contained in the parts of the apparatus which have to be opened for recharging or for the removal of sludge, can be removed before they are opened. 8. Automatic generators of which the decomposing chambers are built inside the gasholder must not exceed 300 litres per hour productive capacity. 9. Generators must be arranged so that after-generation cannot produce objectionable results. 10. The holder of carbide-to-water generators must be large enough to take all the gas which may be produced by the introduction of one charge of carbide without undue pressure ensuing. 11. The maximum pressure permissible in any part of the apparatus is 1.1 atmosphere absolute. 12. The temperature in the gas space of a generator must never exceed 80° C. 13. Generating apparatus, &c., must be constructed in a workmanlike manner of metal capable of resisting rust and distortion, and, where the metal comes in contact with carbide or acetylene, it must not be one (copper in particular) which forms an explosive compound with the gas. Cocks and screw connexions, &c., of brass, bronze, &c., must always be kept clean. Joints exposed to acetylene under pressure must be made by riveting or welding except that in apparatus not exceeding 100 litres per hour productive capacity double bending may be used. 14. Every apparatus must be fitted with a safety-valve or vent-pipe terminating in a safe place in the open, and of adequate size. 15. Every apparatus must be provided with an efficient purifier so fitted that it may be isolated from the rest of the plant and with due consideration of the possible action of the purifying material upon the metal used. 16. Mercury pressure gauges are prohibited. Liquid gauges, if used must be double the length normally needed, and with a cock which in automatic apparatus must be kept shut while it is in action. 17. Proper steps must always be taken to prevent the apparatus freezing. In the absence of other precautions water-seals and pressure-gauges must be filled with liquid having a sufficiently low freezing-point and without action on acetylene or the containing vessel. 18. Signal devices to show the position of the gasholder bell must not be capable of producing sparks inside the apparatus house. 19. Leaks must not be sought for with an open flame and repairs requiring the use of a blow-pipe, &c., must only be carried out after the apparatus has been taken to pieces or freed from gas by flooding. 20. Apparatus must only be attended to by trustworthy and responsible adults. 21. Portable apparatus holding not more than 1 kilo. of carbide and of not more than 50 litres per hour productive capacity, and apparatus fixed and used out of doors are exempt from the foregoing regulations except Nos. 11 and 12, and the first part of 13. In regard to (_b_), plant houses, it is enacted that: 1. Rooms containing acetylene apparatus must be of ample size, used for no other purpose, have water-tight floors, be warmed without fireplaces or chimneys, be lighted from outside through an air-tight window by an independent artificial light, have doors opening outwards, efficient ventilation and a store of sand or like material for fire extinction. Strangers must be warned away. 2. Apparatus of not more than 300 litres per hour productive capacity may be erected in basements or annexes of dwelling houses, but if of over 50 litres per hour capacity must not be placed under rooms regularly frequented. Rooms regularly frequented and those under the same must not be used. 3. Apparatus of more than 300 litres per hour productive capacity must be erected in an independent building at least 15 feet distant from other property, which building, unless it is at least 30 feet distant, must be of fire-proof material externally. 4. Gasholders exceeding 280 cubic foot in capacity must be in a detached room or in the open and inaccessible to strangers, and at least 30 feet from other property and with lightning conductors. 5. In case of fire the main cock must not be shut until it is ascertained that no one remains in the room served with the gas. 6. All acetylene installations must be known to the local fire brigade. In regard to (_c_), pipes, it is enacted that: 1. Mains for acetylene must be separated from the generating apparatus by a cock, and under a five-minute test for pressure must not show a fall of over eight-tenths inch when the pressure is 13.8 inches, or three times the working pressure, whichever is greater. 2. The pipes must as a rule be of iron, though lead may be used where they are uncovered and not exposed to risk of injury. Rubber connexions may only be used for portable apparatus, and attached to a terminal on the metal pipes provided with a cock, and be fastened at both ends so that they will not slip off the nozzles. In regard to (_d_), residues, it is enacted that special open or well-ventilated pits must be provided for their reception when the apparatus exceeds 300 litres per hour productive capacity. With smaller apparatus they may be discharged into cesspools if sufficiently diluted. The ITALIAN GOVERNMENT regulations in regard to acetylene plant are divided into eight sections. The first of these relates to the production and use of liquid and compressed acetylene. The production and use of liquid acetylene is prohibited except under the provisions of the laws relating to explosives. Neat acetylene must not be compressed to more than l-1/2 atmospheres except that an absolute pressure of 10 atmospheres is allowed when the gas is dissolved in acetone or otherwise rendered free from risk. Mixtures of acetylene with air or oxygen are forbidden, irrespective of the pressure or proportions. Mixtures of acetylene with hydrocarbons, carbonic oxide, hydrogen and inert gases are permitted provided the proportion of acetylene does not exceed 50 per cent. nor the absolute pressure 10 atmospheres. The second section relates to acetylene installations, which are classified in four groups, viz., (_a_) fixed or portable apparatus supplying not more than thirty burners consuming 20 litres per hour; (_b_) private installations supplying between 30 and 200 such burners; (_c_) public or works installations supplying between 30 and 200 such burners; (_d_) installations supplying more than 200 such burners. The installations must comply with the following general conditions: 1. No part of the generator when working at its utmost capacity should attain a temperature of more than 100° C. 2. The carbide must be completely decomposed in the apparatus so that no acetylene can be evolved from the residue. The residues must be diluted with water before being discharged into drains or cesspools, and sludge storage-pits must be in the open. 3. The apparatus must preclude the escape of lime into the gas and water connexions. 4. Glass parts must be adequately protected. 5. Rubber connexions between the generator, gasholder, and main are absolutely prohibited with installations supplying more than 30 burners. 6. Cocks must be provided for cutting off the main and connexions from the generator and gasholder. 7. Each burner must have an independent tap. 8. Generators of groups (_b_), (_c_), and (_d_) must be constructed so that no after-generation of acetylene can take place automatically and that any surplus gas would in any case be carried out of the generator house by a vent-pipe. The third section deals with generator houses, which must be well ventilated and light; must not be used for any other purpose except to store one day's consumption of carbide, not exceeding 300 kilos.; must be fire-proof; must have doors opening outwards; and the vent-pipes must terminate at a safe place in the open. Apparatus of group (_b_) must not be placed in a dwelling-room and only in an adjoining room if the gasholder is of less than 600 litres capacity. Apparatus of group (_c_) must be in an independent building which must be at least 33 feet from occupied premises if the capacity of the gasholder is 6000 litres and upwards. Half this distance suffices for gasholders containing 600 to 6000 litres. These distances may be reduced at the discretion of the local authorities provided a substantial partition wall at least 1 foot thick is erected. Apparatus of group (_d_) must be at least 50 feet from occupied premises and the gasholder and generator must not be in the same building. The fourth section deals with the question of authorisation for the installation of acetylene plant. Apparatus of group (_a_) may be installed without obtaining permission from any authorities. In regard to apparatus of the other groups, permission for installation must be obtained from local or other authorities. The fifth section relates to the working of acetylene plant. It makes the concessionaires and owners of the plant responsible for the manipulation and supervision of the apparatus, and for the employment of suitable operators, who must not be less than 18 years of age. The sixth section relates to the inspection of acetylene plant from time to time by inspectors appointed by the local or other authorities. Apparatus of group (_a_) is not subject to these periodical inspections. The seventh section details the fees payable for the inspection of installations and carbide stores, and fixes the penalties for non- compliance with the regulations. The eighth section refers to the notification of the position and description of all carbide works, stores, and acetylene installations to the local authorities. The HUNGARIAN GOVERNMENT rules for the construction and examination of acetylene plant forbid the use of copper and of its alloys; cocks, however, may be made of a copper alloy. The temperature in the gas space of a fixed generator must not exceed 50° C., in that of a portable apparatus 80° C. The maximum effective pressure permissible is 0.15 atmosphere. The CONSEIL D'HYGIÈNE DE LA SEINE IN FRANCE allows a maximum pressure of 1.5 metres, i.e., 59 inches, of water column in generators used for the ordinary purposes of illumination; but apparatus intended to supply gas to the low-pressure oxy-acetylene blowpipe (see Chapter IX.) may develop up to 2.5 metres, or 98.5 inches of water pressure, provided copper and its alloys are entirely excluded from the plant and from the delivery- pipes. The NATIONAL BOARD OF FIRE UNDERWRITERS OF THE UNITED STATES OF AMERICA has issued a set of rules and requirements, of which those relating to acetylene generators and plant are reproduced below. The underwriters state that, "To secure the largest measure of safety to life and property, these rules for the installation of acetylene gas machines must be observed." RULES FOR THE INSTALLATION AND USE OF ACETYLENE GAS GENERATORS. [Footnote: The "gallon" of these rules is, of course, the American gallon, which is equal to 0.83 English standard gallon.] The use of liquid acetylene or gas generated therefrom is absolutely prohibited. Failure to observe these rules is as liable to endanger life as property. To secure the largest measure of safety to life and property, the following rules for the installation of acetylene gas machines must be observed. _Class A.--Stationary Automatic Apparatus._ 1. FOUNDATIONS.--(_a_) Must, where practicable, be of brick, stone, concrete or iron. If necessarily of wood they shall be extra heavy, located in a dry place and open to the circulation of air. The ordinary board platform is not satisfactory. Wooden foundations shall be of heavy planking, joists or timbers, arranged so that the air will circulate around them so as to form a firm base. (_b_) Must be so arranged that the machine will be level and unequal strain will not be placed on the generator or connexions. 2. LOCATION.--(_a_) Generators, especially in closely built up districts should preferably be placed outside of insured buildings in generator houses constructed and located in compliance with Rule 9. (_b_) Generators must be so placed that the operating mechanism will have room for free and full play and can be adjusted without artificial light. They must not be subject to interference by children or careless persons, and if for this purpose further enclosure is necessary, it must be furnished by means of slatted partitions permitting the free circulation of air. (_c_) Generators which from their construction are rendered inoperative during the process of recharging must be so located that they can be recharged without the aid of artificial light. (_d_) Generators must be placed where water will not freeze. 3. ESCAPES OR RELIEF-PIPES.--Each generator must be provided with an escape or relief-pipe of ample size; no such pipe to be less than 3/4- inch internal diameter. This pipe shall be substantially installed, without traps, and so that any condensation will drain back to the generator. It must be carried to a suitable point outside the building, and terminate in an approved hood located at least 12 feet above ground and remote from windows. The hood must be constructed in such a manner that it cannot be obstructed by rain, snow, ice, insects or birds. 4. CAPACITY.--(_a_) Must be sufficient to furnish gas continuously for the maximum lighting period to all lights installed. A lighting period of at least 5 hours shall be provided for in every case. (_b_) Generators for conditions of service requiring lighting period of more than 5 hours must be of sufficient capacity to avoid recharging at night. The following ratings will usually be found advisable. (i) For dwellings, and where machines are always used intermittently, the generator must have a rated capacity equal to the total number of burners installed. (ii) For stores, opera houses, theatres, day-run factories, and similar service, the generator must have a rated capacity of from 30 to 50 per cent, in excess of the total number of burners installed. (iii) For saloons and all night or continued service, the generator must have a rated capacity of from 100 to 200 per cent. in excess of the total number of burners installed. (_c_) A small generator must never be installed to supply a large number of lights, even though it seems probable that only a few lights will be used at a time. _An overworked generator adds to the cost of producing acetylene gas_. 5. CARBIDE CHARGES.--Must be sufficient to furnish gas continuously for the maximum lighting period to all burners installed. In determining charges lump carbide must be estimated as capable of producing 4-1/2 cubic foot of gas to the pound, commercial 1/4-inch carbide 4 cubic feet of gas to the pound, and burners must be considered as requiring at least 25 per cent. more than their rated consumption of gas. 6. BURNERS.--Burners consuming one-half of a cubic foot of gas per hour are considered standard in rating generators. Those having a greater or less capacity will decrease or increase the number of burners allowable in proportion. Burners usually consume from 25 to 100 per cent. more than their rated consumption of gas, depending largely on the working pressure. The so- called 1/2-foot burner when operated at pressures of from 20- to 25- tenths inches water column (2 to 2-1/2 inches) is usually used with best economy. 7. PIPING.--(_a_) Connexions from generators to service-pipes must be made with right and left thread nipples or long thread nipples with lock nuts. All forms of unions are prohibited. (_b_) Piping must, as far as possible, be arranged so that any moisture will drain back to the generator. If low points occur of necessity in any piping, they must be drained through tees into drip cups permanently closed with screw caps or plugs. No pet-cocks shall be used. (_c_) A valve and by-pass connexion must be provided from the service-pipe to the blow-off for removing the gas from the holder in case it should be necessary to do so. (_d_) The schedule of pipe sizes for piping from generators to burners should conform to that commonly used for ordinary gas, but in no case must the feeders be smaller than three-eighths inch. The following schedule is advocated: 3/8 inch pipe, 26 feet, three burners. 1/2 inch pipe, 30 feet, six burners. 3/4 inch pipe, 50 feet, twenty burners. 1 inch pipe, 70 feet, thirty-five burners. 1-1/4 inch pipe, 100 feet, sixty burners. 1-1/2 inch pipe, 150 feet, one hundred burners. 2 inch pipe, 200 feet, two hundred burners. 2-1/2 inch pipe, 300 feet, three hundred burners. 3 inch pipe, 450 feet, four hundred and fifty burners, 3-1/2 inch pipe, 500 feet, six hundred burners. 4 inch pipe, 600 feet, seven hundred and fifty burners. (_e_) Machines of the carbide-feed type must not be fitted with continuous drain connexions leading to sewers, but must discharge into suitable open receptacles which may have such connections. (_f_) Piping must be thoroughly tested both before and after the burners have been installed. It must not show loss in excess of 2 inches within twelve hours when subjected to a pressure equal to that of 15 inches of mercury. (_g_) Piping and connexions must be installed by persons experienced in the installation of acetylene apparatus. 8. CARE AND ATTENDANCE.--In the care of generators designed for a lighting period of more than five hours always clean and recharge the generating chambers at regular stated intervals, regardless of the number of burners actually used. Where generators are not used throughout the entire year always remove all water and gas and clean thoroughly at the end of the season during which they are in service. It is usually necessary to take the bell portion out and invert it so as to allow all gas to escape. This should never be done in the presence of artificial light or fire of any kind. Always observe a regular time, during daylight hours only, for attending to and charging the apparatus. In charging the generating chambers of water-feed machines clean all residuum carefully from the containers and remove it at once from the building. Separate from the mass any unslacked carbide remaining and return it to the containers, adding now carbide as required. Be careful never to fill the containers over the specified mark, as it is important to allow for the swelling of the carbide when it comes in contact with water. The proper action and economy of the machine are dependent on the arrangement and amount of carbide placed in the generator. Carefully guard against the escape of gas. Whenever recharging with carbide always replenish the water-supply. Never deposit residuum or exhausted material from water-feed machines in sewer-pipes or near inflammable material. Always keep water-tanks and water-seals filled with clean water. Never test the generator or piping for leaks with a flame, and never apply flame to an outlet from which the burner has been removed. Never use a lighted match, lamp, candle, lantern or any open light near the machine. Failure to observe the above cautions is as liable to endanger life as property. 9. OUTSIDE GENERATOR HOUSES.--(_a_) Outside generator houses should not be located within 5 feet of any opening into, nor shall they open toward any adjacent building, and must be kept under lock and key. (_b_) The dimensions must be no greater than the apparatus requires to allow convenient room for recharging and inspection of parts. The floor must be at least 12 inches above grade and the entire structure thoroughly weather-proof. (_c_) Generator houses must be thoroughly ventilated, and any artificial heating necessary to prevent freezing shall be done by steam or hot-water systems. (_d_) Generator houses must not be used for the storage of calcium carbide except in accordance with the rules relating to that subject (_vide_ Chapter II.). _Class B.--Stationary Non-Automatic Apparatus_. 10. FOUNDATIONS.--(_a_) Must be of brick, stone or concrete. (_b_) Must be so arranged that the machine will be level and so that strain will not be brought upon the connexions. 11. GAS-HOUSES.--(_a_) Must be constructed entirely of non- combustible material and must not be lighted by any system of illumination involving open flames. (_b_) Must be heated, where artificial heating is necessary to prevent freezing, by steam or hot-water systems, the heater to be located in a separate building, and no open flames to be permitted within generator enclosures. (_c_) Must be kept closed and locked excepting during daylight hours. (_d_) Must be provided with a permanent and effective system of ventilation which will be operative at all times, regardless of the periods of operation of the plant. 12. ESCAPE-PIPES.--Each generator must be provided with a vent-pipe of ample size, substantially installed, without traps. It must be carried to a suitable point outside the building and terminate in an approved hood located at least 12 feet above ground and remote from windows. The hood must be constructed in such a manner that it cannot be obstructed by rain, snow, ice, insects or birds. 13. CARE AND MAINTENANCE.--All charging and cleaning of apparatus, generation of gas and execution of repairs must be done during daylight hours only, and generators must not be manipulated or in any way tampered with in the presence of artificial light. This will require gasholders of a capacity sufficient to supply all lights installed for the maximum lighting period, without the necessity of generation of gas at night or by artificial light. In the operation of generators of the carbide-feed type it is important that only a limited amount of carbide be fed into a given body of water. An allowance of at least one gallon of generating water per pound of carbide must be made in every case, and when this limit has been reached the generator should be drained and flushed, and clean water introduced. These precautions are necessary to avoid over-heating during generation and accumulation of hard deposits of residuum in the generating chamber. (Rule 14, referring to the storage of carbide, has been quoted in Chapter II. (page 19)). RULES FOR THE CONSTRUCTION OF GENERATORS. The following Rules are intended to provide only against the more hazardous defects usually noted in apparatus of this kind. The Rules do not cover all details of construction nor the proper proportioning of parts, and devices which comply with these requirements alone are not necessarily suitable for listing as permissible for use. These points are often only developed in the examination required before permission is given for installation. _Class A.--Stationary Apparatus for Isolated Installations._ 15. GENERAL RULES. GENERATORS.--(_a_) Must be made of iron or steel, and in a manner and of material to insure stability and durability. (_b_) Must be automatically regulated and uniform in their action, producing gas only as immediate consumption demands, and so designed that gas is generated without producing sufficient heat to cause yellow discoloration of residuum (which will occur at about 500° F.) or abnormal pressure at any stage of the process when using carbide of any degree of fineness. The presence of excessive heat tends to change the chemical character of the gas and may even cause its ignition, while in machines of the carbide-feed type, finely divided carbide will produce excessive pressure unless provision is made to guard against it. (_c_) Must be so arranged that during recharging, back flow of gas from the gasholder will be automatically prevented, or so arranged that it will be impossible to charge the apparatus without first closing the supply-pipe to the gasholder, and to the other generating chambers if several are used. This is intended to prevent the dangerous escape of gas. (_d_) The water or carbide supply to the generating chamber must be so arranged that gas will be generated long enough in advance of the exhaustion of the supply already in the gasholder to allow the using of all lights without exhausting such supply. This provides for the continuous working of the apparatus under all conditions of water-feed and carbide charge, and it obviates the extinction of lights through intermittent action of the machine. (_e_) No valves or pet-cocks opening into the room from the gas- holding part or parts, the draining of which will allow an escape of gas, are permitted, and condensation from all parts of the apparatus must be automatically removed without the use of valves or mechanical working parts. Such valves and pet-cocks are not essential; their presence increases the possibility of leakage. The automatic removal of condensation from the apparatus is essential to the safe working of the machine. U-traps opening into the room from the gas-holding parts must not be used for removal of condensation. All sealed drip connexions must be so arranged as to discharge gas to the blow-off when blown out, and the seals must be self-restoring upon relief of abnormal pressure. (_f_) The apparatus must be capable of withstanding fire from outside causes. Sheet-metal joints must be double-seamed or riveted and thoroughly sweated with solder. Pipes must be attached to sheet-metal with lock-nuts or riveted flanges. This prohibits the use of wood or of joints relying entirely upon solder. (_g_) Gauge glasses, the breakage of which would allow the escape of gas, must not be used. (_h_) The use of mercury seals is prohibited. Mercury has been found unreliable as a seal in acetylene apparatus.(_i_) Combustible oils must not be used in connexion with the apparatus. (_j_) The construction must be such that liquid seals shall not become thickened by the deposit of lime or other foreign matter. (_k_) The apparatus must be constructed so that accidental siphoning of water will be impossible. (_l_) Flexible tubing, swing joints, unions, springs, mechanical check-valves, chains, pulleys, stuffing-boxes and lead or fusible piping must not be used on acetylene apparatus except where failure of such parts will not vitally affect the working or safety of the machine. Floats must not be used excepting in cases where failure will result only in rendering the machine inoperative. (_m_) Every machine must be plainly marked with the maximum number of lights it is designed to supply, the amount of carbide necessary for a single charge, the manufacturer's name and the name of the machine. 16. GENERATING CHAMBERS.--(_a_) Must be constructed of galvanised iron or steel not less than No. 24 U.S. Standard gauge in thickness for capacities up to and including 20 gallons, not less than No. 22 U.S. Standard gauge for capacities between 20 and 75 gallons, and not less than No. 20 U.S. Standard gauge for capacities in excess of 75 gallons. (_b_) Must each be connected with the gasholder in such a manner that they will, at all times, give open connexion either to the gasholder or to the blow-off pipe to the outer air. This prevents dangerous pressure within or the escape of gas from the generating chamber. (_c_) Must be so constructed that not more than 5 pounds of carbide can be acted upon at once, in machines which apply water in small quantities to the carbide. This tends to reduce the danger of overheating and excessive after- generation by providing for division of the carbide charges in machines of this type. (_d_) Must be provided with covers having secure fastenings to hold them properly in place and those relying on a water-seal must be submerged in at least 12 inches of water. Water-seal chambers for covers depending on a water-seal must be 1-1/2 inches wide and 15 inches deep, excepting those depending upon the filling of the seal chambers for the generation of gas, where 9 inches will be sufficient. (_e_) Must be so designed that the residuum will not clog or affect the working of the machine and can conveniently be handled and removed. (_f_) Must be provided with suitable vent connexions to the blow-off pipe so that residuum may be removed and the generating water replaced without causing siphoning or introducing air to the gasholder upon recharging. This applies to machines of the carbide-feed type. (_g_) Feed mechanism for machines of the carbide-feed type must be so designed that the direct fall of carbide from the carbide holder into the water of the generator is prevented at all positions of the feed mechanisms; or, when actuated by the rise and fall of a gas-bell, must be so arranged that the feed-valve will not remain open after the landing of the bell, and so that the feed valve remains inoperative as long as the filling opening on the carbide hopper remains open. Feed mechanisms must always be far enough above the water-level to prevent clogging from the accumulation of damp lime. For this purpose the distance should be not less than 10 inches. 17. CARBIDE CHAMBERS.--(_a_) Must be constructed of galvanised iron or steel not less than No. 24 U.S. Standard gauge in thickness for capacities up to and including 50 pounds and not less than No. 22 U.S. Standard gauge for capacities in excess of 50 pounds. (_b_) Must have sufficient carbide capacity to supply the full number of burners continuously and automatically during the maximum lighting period. This rule removes the necessity of recharging or attending to the machine at improper hours. Burners almost invariably require more than their rated consumption of gas, and carbide is not of staple purity, and there should therefore be an assurance of sufficient quantity to last as long as light is needed. Another important consideration is that in some establishments burners are called upon for a much longer period of lighting than in others, requiring a generator of greater gas-producing capacity. Machines having several generating chambers must automatically begin generation in each upon exhaustion of the preceding chamber. (_c_) Must be arranged so that the carbide holders or charges may be easily and entirely removed in case of necessity. 18. GASHOLDERS.--(_a_) Must be constructed of galvanised iron or steel not less than No. 24 U.S. Standard gauge in thickness for capacities up to and including 20 gallons, not less than No. 22 U.S. Standard gauge for capacities between 20 and 75 gallons, and not less than No. 20 U.S. Standard gauge for capacities in excess of 75 gallons. Gas-bells, if used, may be two gauges lighter than holders. Condensation chambers, if placed under holders, to be of same gauge as holders. (_b_) Must be of sufficient capacity to contain all gas generated after all lights have been extinguished. If the holder is too small and blows off frequently after the lights are extinguished there is a waste of gas. This may suggest improper working of the apparatus and encourage tampering. (_c_) Must, when constructed on the gasometer principle, be so arranged that when the gas-bell is filled to its maximum with gas at normal pressure its lip or lower edge will extend at least 9 inches below the inner water-level. (_d_) Must, when constructed on the gasometer principle, have the dimensions of the tank portion so related to those of the bell that a pressure of at least 11 inches will be necessary before gas can be forced from the holder. (_e_) The bell portion of a gasholder constructed on the gasometer principle must be provided with a substantial guide to its upward movement, preferably in the centre of the holder, carrying a stop acting to chock the bell 1 inch above the normal blow-off point. This tends to insure the proper action of the bell and decreases the liability of escaping gas. (_f_) A space of at least three-quarters of an inch must be allowed between the sides of the tank and the bell. (_g_) All water-seals must be so arranged that the water-level may be readily seen and maintained. 19. WATER-SUPPLY.--(_a_) The supply of water to the generator for generating purposes must not be taken from the water-seal of any gasholder constructed on the gasometer principle, unless the feed mechanism is so arranged that the water-seals provided for in Rules 18, (_c_), (_d_), and (_e_) may be retained under all conditions. This provides for the proper level of water in the gasholder. (_b_) In cases where machines of the carbide-feed type are supplied with water from city water-mains or house-pipes, the pipe connexion must discharge into the regularly provided filling trap on the generator and not through a separate continuous connexion leading into the generating chamber. This is to prevent the expulsion of explosive mixtures through the filling trap in refilling. 20. RELIEFS OR SAFETY BLOW-OFFS.--(_a_) Must in all cases be provided, and must afford free vent to the outer air for any over- production of gas, and also afford relief in case of abnormal pressure in the machine. Both the above-mentioned vents may be connected, with the same escape- pipe. (_b_) Must be of at least 3/4-inch internal diameter and be provided with suitable means for connecting to the pipe loading outside of the building. (_c_) Must be constructed without valves or other mechanical working parts. (_d_) Apparatus requiring pressure regulators must be provided with an additional approved safety blow-off attachment located between the pressure regulator and the service-pipes and discharging to the outer air. This is intended to prevent the possibility of undue pressure in the service-pipes due to failure of the pressure regulator. 21. PRESSURES.--(_a_) The working pressure at the generator must not vary more than ten-tenths (1) inch water column under all conditions of carbide charge and feed, and between the limits of no load and 50 per cent. overload. (_b_) Apparatus not requiring pressure regulators must be so arranged that the gas pressure cannot exceed sixty-tenths (6) inches water column. This requires the use of the pressure relief provided for in Rule No. 20 (_a_). (_c_) Apparatus requiring pressure regulators must be so arranged that the gas pressure cannot exceed three pounds to the square inch. The pressure limit of 3 pounds is taken since that is the pressure corresponding to a water column about 6 feet high, which is about, the limit in point of convenience for water-sealed reliefs. 22. AIR MIXTURES.--Generators must be so arranged as to contain the minimum amount of air when first started or recharged, and no device or attachment facilitating or permitting mixture of air with the gas prior to consumption, except at the burners, shall be allowed. Owing to the explosive properties of acetylene mixed with air, machines must be so designed that such mixtures are impossible. 23. PURIFIERS.--(_a_) Must be constructed of galvanised iron or steel not less than No. 24 U.S. Standard gauge in thickness. (_b_) Where installed, purifiers must conform to the general rules for the construction of other acetylene apparatus and allow the free passage of gas. (_c_) Purifiers must contain no carbide for drying purposes. (_d_) Purifiers must be located inside of gasholders, or, where necessarily outside, must have no hand-holes which can be opened without first shutting off the gas-supply. 24. PRESSURE REGULATORS.--(_a_) Must conform to the rules for the construction of other acetylene apparatus so far as they apply and must not be subject to sticking or clogging. (_b_) Must be capable of maintaining a uniform pressure, not varying more than four-tenths inch water column, at any load within their rating. (_c_) Must be installed between valves in such a manner as to facilitate inspection and repairs. _Class B.--Stationary Apparatus for Central Station Service._ Generators of over 300 lights capacity for central station service are not required to be automatic in operation. Generators of less than 300 lights capacity must be automatic in operation and must comply in every respect with the requirements of Class A. 25. GENERAL RULES. GENERATORS.--(_a_) Must be substantially constructed of iron or steel and be protected against depreciation by an effective and durable preventive of corrosion. Galvanising is strongly recommended as a protection against oxidation, and it may to advantage be reinforced by a thorough coating of asphaltum or similar material. (_b_) Must contain no copper or alloy of copper in contact with acetylene, excepting in valves. (_c_) Must be so arranged that generation will take place without overheating; temperatures in excess of 500° F. to be considered excessive. (_d_) Must be provided with means for automatic removal of condensation from gas passages. (_e_) Must be provided with suitable protection against freezing of any water contained in the apparatus. No salt or other corrosive chemical is permissible as a protection against freezing. (_f_) Must in general comply with the requirements governing the construction of apparatus for isolated installations so far as they are applicable. (_g_) Must be so arranged as to insure correct procedure in recharging and cleaning. (_h_) Generators of the carbide-feed type must be provided with some form of approved measuring device to enable the attendant to determine when the maximum allowable quantity of carbide has been fed into the generating chamber. In the operation of generators of this type an allowance of at least 1 gallon of clean generating water per pound of carbide should be made, and the generator should be cleaned after slaking of every full charge. Where lump carbide is used the lumps may become embedded in the residuum, if the latter is allowed to accumulate at the bottom of the generating chamber, causing overheating from slow and restricted generation, and rendering the mass more liable to form a hard deposit and bring severe stresses upon the walls of the generator by slow expansion. 26. GENERATING CHAMBERS.--(_a_) Must each be connected with the gasholder in such a manner that they will, at all times, give open connexion either to the gasholder or to the blow-off pipe into the outer air. (_b_) Must be so arranged as to guard against appreciable escape of gas to the room at any time during the introduction of the charges. (_c_) Must be so designed that the residuum will not clog or affect the operation of the machine and can conveniently be handled and removed. (_d_) Must be so arranged that during the process of cleaning and recharging the back-flow of gas from the gasholder or other generating chambers will be automatically prevented. 27. GASHOLDERS.--(_a_) Must be of sufficient capacity to contain at least 4 cubic feet of gas per 1/2-foot burner of the rating. This is to provide for the requisite lighting period without the necessity of making gas at night, allowance being made for the enlargement of burners caused by the use of cleaners. (_b_) Must be provided with suitable guides to direct the movement of the bell throughout its entire travel. 28. PRESSURE RELIEFS.--Must in all cases be provided, and must be so arranged as to prevent pressure in excess of 100-tenths (10) inches water column in the mains. 29. PRESSURES.--Gasholders must be adjusted to maintain a pressure of approximately 25-tenths (2.5) inches water column in the mains. CHAPTER V THE TREATMENT OF ACETYLENE AFTER GENERATION IMPURITIES IN CALCIUM CARBIDE.--The calcium carbide manufactured at the present time, even when of the best quality commercially obtainable, is by no means a chemically pure substance; it contains a large number of foreign bodies, some of which evolve gas on treatment with water. To a considerable extent this statement will probably always remain true in the future; for in order to make absolutely pure carbide it would be necessary for the manufacturer to obtain and employ perfectly pure lime, carbon, and electrodes in an electric furnace which did not suffer attack during the passage of a powerful current, or he would have to devise some process for simultaneously or subsequently removing from his carbide those impurities which were derived from his impure raw materials or from the walls of his furnace--and either of these processes would increase the cost of the finished article to a degree that could hardly be borne. Beside the impurities thus inevitably arising from the calcium carbide decomposed, however, other impurities may be added to acetylene by the action of a badly designed generator or one working on a wrong system of construction; and therefore it may be said at once that the crude gas coming from the generating plant is seldom fit for immediate consumption, while if it be required for the illumination of occupied rooms, it must invariably be submitted to a rigorous method of chemical purification. IMPURITIES OF ACETYLENE.--Combining together what may be termed the carbide impurities and the generator impurities in crude acetylene, the foreign bodies are partly gaseous, partly liquid, and partly solid. They may render the gas dangerous from the point of view of possible explosions; they, or the products derived from them on combustion, may be harmful to health if inspired, injurious to the fittings and decorations of rooms, objectionable at the burner orifices by determining, or assisting in, the formation of solid growths which distort the flame and so reduce its illuminating power; they may give trouble in the pipes by condensing from the state of vapour in bends and dips, or by depositing, if they are already solid, in angles, &c., and so causing stoppages; or they may be merely harmful economically by acting as diluents to the acetylene and, by having little or no illuminating value of themselves, causing the gas to emit less light than it should per unit of volume consumed, more particularly, of course, when the acetylene is not burnt under the mantle. Also, not being acetylene, or isomeric therewith, they require, even if they are combustible, a different proportion of oxygen for their perfect combustion; and a good acetylene jet is only calculated to attract precisely that quantity of air to the flame which a gas having the constitution C_2H_2 demands. It will be apparent without argument that a proper system of purification is one that is competent to remove the carbide impurities from acetylene, so far as that removal is desirable or necessary; it should not be called upon to extract the generator impurities, because the proper way of dealing with them is, to the utmost possible extent, to prevent their formation. The sole exception to this rule is that of water-vapour, which invariably accompanies the best acetylene, and must be partially removed as soon as convenient. Vapour of water almost always accompanies acetylene from the generator, even when the apparatus does not belong to those systems of working where liquid water is in excess, this being due to the fact that in a generator where the carbide is in excess the temperature tends to rise until part of the water is vapourised and carried out of the decomposing chamber before it has an opportunity of reacting with the excess of carbide. The issuing gas is therefore more or less hot, and it usually comes from the generating chamber saturated with vapour, the quantity needed so to saturate it rising as the temperature of the gas increases. Practically speaking, there is little objection to the presence of water-vapour in acetylene beyond the fear of deposition of liquid in the pipes, which may accumulate till they are partially or completely choked, and may even freeze and burst them in very severe weather. Where the chemical purifiers, too, contain a solid material which accidentally or intentionally acts as a drier by removing moisture from the acetylene, it is a waste of such comparatively expensive material to allow gas to enter the purifier wetter than need be. EXTRACTION OF MOISTURE.--In all large plants the extraction of the moisture may take place in two stages. Immediately after the generator, and before the washer if the generator requires such an apparatus to follow it, a condenser is placed. Here the gas is made to travel somewhat slowly through one or more pipes surrounded with cold air or water, or is made to travel through a space containing pipes in which cold water is circulating, the precise method of constructing the condenser being perfectly immaterial so long as the escaping gas has a temperature not appreciably exceeding that of the atmosphere. So cooled, however, the gas still contains much water-vapour, for it remains saturated therewith at the temperature to which it is reduced, and by the inevitable law of physics a further fall in temperature will be followed by a further deposition of liquid water from the acetylene. Manifestly, if the installation is so arranged that the gas can at no part of the service and on no occasion fall to a lower temperature than that at which it issues from the condenser, the removal of moisture as effected by such a condenser will be sufficient for all practical purposes; but at least in all large plants where a considerable length of main is exposed to the air, a more complete moisture extractor must be added to the plant, or water will be deposited in the pipes every cold night in the winter. It is, however, useless to put a chemical drier, or one more searching in its action than a water-cooled condenser, at so early a position in the acetylene plant, because the gas will be subsequently stored in a water- sealed holder, where it will most probably once again be saturated with moisture from the seal. When such generators are adopted as require to have a specific washer placed after them in order to remove the water- soluble impurities, _e.g._, those in which the gas does not actually bubble through a considerable quantity of liquid in the generating chamber itself, it is doubtful whether a separate condenser is altogether necessary, because, as the water in the washer can easily be kept at the atmospheric temperature (by means of water circulating in pipes or otherwise), the gas will be brought to the atmospheric temperature in the washer, and at that temperature it cannot carry with it more than a certain fixed proportion of moisture. The notion of partially drying a gas by causing it to pass through water may appear paradoxical, but a comprehension of physical laws will show that it is possible, and will prove efficient in practice, when due attention is given to the facts that the gas entering the washer is hot, and that it is subsequently to be stored over water in a holder. GENERATOR IMPURITIES.--The generator impurities present in the crudest acetylene consist of oxygen and nitrogen, _i.e._, the main constituents of air, the various gaseous, liquid, and semi-solid bodies described in Chapter II., which are produced by the polymerising and decomposing action of heat upon the carbide, water, and acetylene in the apparatus, and, whenever the carbide is in excess in the generator, some lime in the form of a very fine dust. In all types of water-to-carbide plant, and in some automatic carbide-feed apparatus, the carbide chamber must be disconnected and opened each time a fresh charge has to be inserted; and since only about one-third of the space in the container can be filled with carbide, the remaining two-thirds are left full of air. It is easy to imagine that the carbide container of a small generator might be so large, or loaded with so small a quantity of carbide, or that the apparatus might in other respects be so badly designed, that the gas evolved might contain a sufficient proportion of air to render it liable to explode in presence of a naked light, or of a temperature superior to its inflaming-point. Were a cock, however, which should have been shut, to be carelessly left open, an escape of gas from, rather than an introduction of air into, the apparatus would follow, because the pressure in the generator is above that of the atmosphere. As is well known, roughly four-fifths by volume of the air consist of nitrogen, which is non-inflammable and accordingly devoid of danger- conferring properties; but in all flames the presence of nitrogen is harmful by absorbing much of the heat liberated, thus lowering the temperature of that flame, and reducing its illuminating power far more seriously. On the other hand, a certain quantity of air in acetylene helps to prevent burner troubles by acting as a mere diluent (albeit an inferior one to methane or marsh-gas), and therefore it has been proposed intentionally to add air to the gas before consumption, such a process being in regular use on the large scale in some places abroad. As Eitner has shown (Chapter VI.) that in a 3/4-inch pipe acetylene ceases to be explosive when mixed with less than 47.7 per cent. of air, an amount of, say, 40 per cent. or less may in theory be safely added to acetylene; but in practice the amount of air added, if any, would have to be much smaller, because the upper limit of explosibility of acetylene-air mixtures is not rigidly fixed, varying from about 50 per cent. of air when the mixture is in a small vessel, and fired electrically to about 25 per cent. of air in a large vessel approached with a flame. Moreover, safely to prepare such mixtures, after the proportion of air had been decided upon, would require the employment of some additional perfectly trustworthy automatic mechanism to the plant to draw into the apparatus a quantity of air strictly in accordance with the volume of acetylene made --a pair of meters geared together, one for the gas, the other for the air--and this would introduce extra complexity and extra expense. On the whole the idea cannot be recommended, and the action of the British Home Office in prohibiting the use of all such mixtures except those unavoidably produced in otherwise good generators, or in burners of the ordinary injector type, is perfectly justifiable. The derivation and effect of the other gaseous and liquid generator impurities in acetylene were described in Chapter II. Besides these, very hot gas has been found to contain notable amounts of hydrogen and carbon monoxide, both of which burn with non-luminous flames. The most plausible explanation of their origin has been given by Lewes, who suggests that they may be formed by the action of water-vapour upon very hot carbide or upon carbon separated therefrom as the result of previous dissociation among the gases present; the steam and the carbon reacting together at a temperature of 500° C. or thereabouts in a manner resembling that of the production of water-gas. The last generator impurity is lime dust, which is calcium oxide or hydroxide carried forward by the stream of gas in a state of extremely fine subdivision, and is liable to be produced whenever water acts rapidly upon an excess of calcium carbide. This lime occasionally appears in the alternative form of a froth in the pipes leading directly from the generating chamber; for some types of carbide-to-water apparatus, decomposing certain kinds of carbide, foam persistently when the liquid in them becomes saturated with lime, and this foam or froth is remarkably difficult to break up. FILTERS.--It has just been stated that the purifying system added to an acetylene installation should not be called upon to remove these generator impurities; because their appearance in quantity indicates a faulty generator, which should be replaced by one of better action. On the contrary, with the exception of the gases which are permanent at atmospheric temperature--hydrogen, carbon monoxide, nitrogen, and oxygen-- and which, once produced, must remain in the acetylene (lowering its illuminating value, but giving no further trouble), extraction of these generator impurities is quite simple. The dust or froth of lime will be removed in the washer where the acetylene bubbles through water--the dust itself can be extracted by merely filtering the gas through cotton-wool, felt, or the like. The least volatile liquid impurities will be removed partly in the condenser, partly in the washer, and partly by the mechanical dry-scrubbing action of the solid purifying material in the chemical purifier. To some extent the more volatile liquid bodies will be removed similarly; but a complete extraction of them demands the employment of some special washing apparatus in which the crude acetylene is compelled to bubble (in finely divided streams) through a layer of some non-volatile oil, heavy mineral lubricating oil, &c.; for though soluble in such oil, the liquid impurities are not soluble in, nor do they mix with, water; and since they are held in the acetylene as vapours, a simple passage through water, or through water-cooled pipes, does not suffice for their recovery. It will be seen that a sufficient removal of these generator impurities need throw no appreciable extra labour upon the consumer of acetylene, for he can readily select a type of generator in which their production is reduced to a minimum; while a cotton-wool or coke filter for the gas, a water washer, which is always useful in the plant if only employed as a non-return valve between the generator and the holder, and the indispensable chemical purifiers, will take out of the acetylene all the remaining generator impurities which need, and can, be extracted. CARBIDE IMPURITIES.--Neglecting very minute amounts of carbon monoxide and hydrogen (which may perhaps come from cavities in the calcium carbide itself), as being utterly insignificant from the practical point of view, the carbide impurities of the gas fall into four main categories: those containing phosphorus, those containing sulphur, those containing silicon, and those containing gaseous ammonia. The phosphorus in the gas comes from calcium phosphide in the calcium carbide, which is attacked by water, and yields phosphoretted hydrogen (or phosphine, as it will be termed hereafter). The calcium phosphide, in its turn, is produced in the electric furnace by the action of the coke upon the phosphorus in phosphatic lime--all commercially procurable lime and some varieties of coke (or charcoal) containing phosphates to a larger or smaller extent. The sulphur in the gas comes from aluminium sulphide in the carbide, which is produced in the electric furnace by the interaction of impurities containing aluminium and sulphur (clay-like bodies, &c.) present in the lime and coke; this aluminium sulphide is attacked by water and yields sulphuretted hydrogen. Even in the absence of aluminium compounds, sulphuretted hydrogen may be found in the gases of an acetylene generator; here it probably arises from calcium sulphide, for although the latter is not decomposed by water, it gradually changes in water into calcium sulphydrate, which appears to suffer decomposition. When it exists in the gas the silicon is derived from certain silicides in the carbide; but this impurity will be dealt with by itself in a later paragraph. The ammonia arises from the action of the water upon magnesium, aluminium, or possibly calcium nitride in the calcium carbide, which are bodies also produced in the electric furnace or as the carbide is cooling. In the gas itself the ammonia exists as such; the phosphorus exists mainly as phosphine, partly as certain organic compounds containing phosphorus, the exact chemical nature of which has not yet been fully ascertained; the sulphur exists partly as sulphuretted hydrogen and partly as organic compounds analogous, in all probability, to those of phosphorus, among which Caro has found oil of mustard, and certain bodies that he regards as mercaptans. [Footnote: It will be convenient to borrow the phrase used in the coal-gas industry, calling the compounds of phosphorus other than phosphine "phosphorus compounds," and the compounds of sulphur other than sulphuretted hydrogen "sulphur compounds." The "sulphur compounds" of coal-gas, however, consist mainly of carbon bisulphide, which is certainly not the chief "sulphur compound" in acetylene, even if present to any appreciable extent.] The precise way in which these organic bodies are formed from the phosphides and sulphides of calcium carbide is not thoroughly understood; but the system of generation employed, and the temperature obtaining in the apparatus, have much to do with their production; for the proportion of the total phosphorus and sulphur found in the crude gas which exists as "compounds" tends to be greater as the generating plant yields a higher temperature. It should be noted that ammonia and sulphuretted hydrogen have one property in common which sharply distinguishes them from the sulphur "compounds," and from all the phosphorus compounds, including phosphine. Ammonia and sulphuretted hydrogen are both very soluble in water, the latter more particularly in the lime-water of an active acetylene generator; while all the other bodies referred to are completely insoluble. It follows, therefore, that a proper washing of the crude gas in water should suffice to remove all the ammonia and sulphuretted hydrogen from the acetylene; and as a matter of fact those generators in which the gas is evolved in presence of a large excess of water, and in which it has to bubble through such water, yield an acetylene practically free from ammonia, and containing nearly all the sulphur which it does contain in the state of "compounds." It must also be remembered that chemical processes which are perfectly suited to the extraction of sulphuretted hydrogen and phosphine are not necessarily adapted for the removal of the other phosphorus and sulphur compounds. WASHERS.--In designing a washer for the extraction of ammonia and sulphuretted hydrogen it is necessary to see that the gas is brought into most intimate contact with the liquid, while yet no more pressure than can possibly be avoided is lost. Subdivision of the gas stream may be effected by fitting the mouth of the inlet-pipe with a rose having a large number of very small holes some appreciable distance apart, or by bending the pipe to a horizontal position and drilling it on its upper surface with numbers of small holes. Another method is to force the gas to travel under a series of partitions extending just below the water- level, forming the lower edges of those partitions either perfectly horizontal or with small notches like the teeth of a saw. One volume of pure water only absorbs about three volumes of sulphuretted hydrogen at atmospheric temperatures, but takes up some 600 volumes of gaseous ammonia; and as ammonia always accompanies the sulphuretted hydrogen, the latter may be said to be absorbed in the washer by a solution of ammonia, a liquid in which sulphuretted hydrogen is much more soluble. Therefore, since water only dissolves about an equal volume of acetylene, the liquid in the washer will continue to extract ammonia and sulphuretted hydrogen long after it is saturated with the hydrocarbon. For this reason, _i.e._, to avoid waste of acetylene by dissolution in the clean water of the washer, the plan is sometimes adopted of introducing water to the generator through the washer, so that practically the carbide is always attacked by a liquid saturated with acetylene. Provided the liquid in the generator does not become seriously heated, there is no objection to this arrangement; but if the water is heated strongly in the generator it loses much or all of its solvent properties, and the impurities may be driven back again into the washer. Clearly if the waste lime of the generator occurs as a dry or damp powder, the plan mentioned is not to be recommended; but when the waste lime is a thin cream--water being in large excess--it may be adopted. If the generator produces lime dust among the gas, and if the acetylene enters the washer through minute holes, a mechanical filter to remove the dust must be inserted between the generator and the washer, or the orifices of the leading pipe will be choked. Whenever a water-cooled condenser is employed after the generator, in which the gas does not come in contact with the water, that liquid may always be used to charge the generator. For compactness and simplicity of parts the water of the holder seal is occasionally used as the washing liquid, but unless the liquid of the seal is constantly renewed it will thus become offensive, especially if the holder is under cover, and it will also act corrosively upon the metal of the tank and bell. The water-soluble impurities in acetylene will not be removed completely by merely standing over the holder seal for a short time, and it is not good practice to pass unnecessarily impure gas into a holder. [Footnote: This is not a contradiction of what has been said in Chapter III. about the relative position of holder and chemical purifiers, because reference is now being made to ammonia and sulphuretted hydrogen only.] HARMFULNESS OF IMPURITIES.--The reasons why the carbide impurities must be removed from acetylene before it is burned have now to be explained. From the strictly chemical point of view there are three compounds of phosphorus, all termed phosphoretted hydrogen or phosphine: a gas, PH_3; a liquid, P_2H_4; and a solid, P_4H_2. The liquid is spontaneously inflammable in presence of air; that is to say, it catches fire of itself without the assistance of spark or flame immediately it comes in contact with atmospheric oxygen; being very volatile, it is easily carried as vapour by any permanent gas. The gaseous phosphine is not actually spontaneously inflammable at temperatures below 100° C.; but it oxidises so rapidly in air, even when somewhat diluted, that the temperature may quickly rise to the point of inflammation. In the earliest days of the acetylene industry, directly it was recognised that phosphine always accompanies crude acetylene from the generator, it was believed that unless the proportion were strictly limited by decomposing only a carbide practically free from phosphides, the crude acetylene might exhibit spontaneously inflammable properties. Lewes, indeed, has found that a sample of carbide containing 1 per cent of calcium phosphide gave (probably by local decomposition--the bulk of the phosphide suffering attack first) a spontaneously inflammable gas; but when examining specimens of commercial carbide the highest amount of phosphine he discovered in the acetylene was 2.3 per cent, and this gas was not capable of self-inflammation. According to Bullier, however, acetylene must contain 80 per cent of phosphine to render it spontaneously inflammable. Berdenich has reported a case of a parcel of carbide which yielded on the average 5.1 cubic foot of acetylene per lb., producing gas which contained only 0.398 gramme of phosphorus in the form of phosphine per cubic metre (or 0.028 per cent. of phosphine) and was spontaneously inflammable. But on examination the carbide in question was found to be very irregular in composition, and some lumps produced acetylene containing a very high proportion of phosphorus and silicon compounds. No doubt the spontaneous inflammability was due to the exceptional richness of these lumps in phosphorus. As manufactured at the present day, calcium carbide ordinarily never contains an amount of phosphide sufficient to render the gas dangerous on the score of spontaneous inflammability; but should inferior material ever be put on the markets, this danger might have to be guarded against by submitting the gas evolved from it to chemical analysis. Another risk has been suggested as attending the use of acetylene contaminated with phosphine (and to a minor degree with sulphuretted hydrogen), viz., that being highly toxic, as they undoubtedly are, the gas containing them might be extremely dangerous to breathe if it escaped from the service, or from a portable lamp, unconsumed. Anticipating what will be said in a later paragraph, the worst kind of calcium carbide now manufactured will not yield a gas containing more than 0.1 per cent. by volume of sulphuretted hydrogen and 0.05 per cent. of phosphine. According to Haldane, air containing 0.07 per cent. of sulphuretted hydrogen produces fatal results on man if it is breathed for some hours, while an amount of 0.2 per cent. is fatal in 1- 1/2 minutes. Similar figures for phosphine cannot be given, because poisoning therewith is very rare or quite unknown: the cases of "phossy- jaw" in match factories being caused either by actual contact with yellow phosphorus or by inhalation of its vapour in the elemental state. However, assuming phosphine to be twice as toxic as sulphuretted hydrogen, its effect in crude acetylene of the above-mentioned composition will be equal to that of the sulphuretted hydrogen, so that in the present connexion the gas may be said to be equally toxic with a sample of air containing 0.2 per cent. of sulphuretted hydrogen, which kills in less than two minutes. But this refers only to crude acetylene undiluted with air; and being a hydrocarbon--being in fact neither oxygen nor common air--acetylene is irrespirable of itself though largely devoid of specific toxic action. Numerous investigations have been made of the amount of acetylene (apart from its impurities) which can be breathed in safety; but although these point to a probable recovery after a fairly long-continued respiration of an atmosphere charged with 30 per cent. of acetylene, the figure is not trustworthy, because toxicological experiments upon animals seldom agree with similar tests upon man. If crude acetylene were diluted with a sufficient proportion of air to remove its suffocating qualities, the percentage of specifically toxic ingredients would be reduced to a point where their action might be neglected; and short of such dilution the acetylene itself would in all probability determine pathological effects long before its impurities could set up symptoms of sulphur and phosphorus poisoning. Ammonia is objectionable in acetylene because it corrodes brass fittings and pipes, and because it is partially converted (to what extent is uncertain) into nitrous and nitric acids as it passes through the flame. Sulphur is objectionable in acetylene because it is converted into sulphurous and sulphuric anhydrides, or their respective acids, as it passes through the flame. Phosphorus is objectionable because in similar circumstances it produces phosphoric anhydride and phosphoric acid. Each of these acids is harmful in an occupied room because they injure the decorations, helping to rot book-bindings, [Footnote: It is only fair to state that the destruction of leather bindings is commonly due to traces of sulphuric acid remaining in the leather from the production employed in preparing it, and is but seldom caused directly by the products of combustion coming from gas or oil.] tarnishing "gold-leaf" ornaments, and spoiling the colours of dyed fabrics. Each is harmful to the human system, sulphuric and phosphoric anhydrides (SO_3, and P_4O_10) acting as specific irritants to the lungs of persons predisposed to affections of the bronchial organs. Phosphorus, however, has a further harmful action: sulphuric anhydride is an invisible gas, but phosphoric anhydride is a solid body, and is produced as an extremely fine, light, white voluminous dust which causes a haze, more or less opaque, in the apartment. [Footnote: Lewes suggests that ammonia in the gas burnt may assist in the production of this haze, owing to the formation of solid ammonium salts in the state of line dust.] Immediately it comes in contact with atmospheric moisture phosphoric anhydride is converted into phosphoric acid, but this also occurs at first as a solid substance. The solidity and visibility of the phosphoric anhydride and acid are beneficial in preventing highly impure acetylene being unwittingly burnt in a room; but, on the other hand, being merely solids in suspension in the air, the combustion products of phosphorus are not so easily carried away from the room by the means provided for ventilation as are the products of the combustion of sulphur. Phosphoric anhydride is also partly deposited in the solid state at the burner orifices, perhaps actually corroding the steatite jets, and always assisting in the deposition of carbon from any polymerised hydrocarbons in the acetylene; thus helping the carbon to block up or distort those orifices. Whenever the acetylene is to be burnt on the incandescent system under a mantle of the Welsbach or other type, phosphorus, and possibly sulphur, become additionally objectionable, and rigorous extraction is necessary. As is well known, the mantle is composed of the oxides of certain "rare earths" which owe their practical value to the fact that they are non-volatile at the temperature of the gas-flame. When a gas containing phosphorus is burnt beneath such a mantle, the phosphoric anhydride attacks those oxides, partially converting them into the respective phosphates, and these bodies are less refractory. A mantle exposed to the combustion products of crude acetylene soon becomes brittle and begins to fall to pieces, occasionally showing a yellowish colour when cold. The actual advantage of burning acetylene on the incandescent system is not yet thoroughly established-- in this country at all events; but it is clear that the process will not exhibit any economy (rather the reverse) unless the plant is provided with most capable chemical purifiers. Phosphorus, sulphur, and ammonia are not objectionable in crude acetylene because they confer upon the gas a nauseous odour. From a well-constructed installation no acetylene escapes unconsumed: the gas remains wholly within the pipes until it is burnt, and whatever odour it may have fails to reach the human nostrils. A house properly piped for acetylene will be no more conspicuous by its odour than a house properly piped for coal-gas. On the contrary, the fact that the carbide impurities of acetylene, which, in the absolutely pure state, is a gas of somewhat faint, hardly disagreeable, odour, do confer upon that gas a persistent and unpleasant smell, is distinctly advantageous; for, owing to that odour, a leak in the pipes, an unclosed tap, or a fault in the generating plant is instantly brought to the consumer's attention. A gas wholly devoid of odour would be extremely dangerous in a house, and would have to be scented, as is done in the case of non-carburetted water-gas when it is required for domestic purposes. AMOUNTS OF IMPURITIES AND SCOPE OF PURIFICATION.--Partly for the reason which has just been given, and partly on the ground of expense, a complete removal of the impurities from crude acetylene is not desirable. All that need be done is to extract sufficient to deprive the gas of its injurious effects upon lungs, decorations, and burners. As it stands, however, such a statement is not sufficiently precise to be useful either to consumers of acetylene or to manufacturers of plant, and some more or less arbitrary standard must be set up in order to define the composition of "commercially pure" acetylene, as well as to gauge the efficiency of any process of purification. In all probability such limit may be reasonably taken at 0.1 milligramme of either sulphur or phosphorus (calculated as elementary bodies) per 1 litre of acetylene, _i.e._, 0.0-1.1 grain per cubic foot; a quantity which happens to correspond almost exactly with a percentage by weight of 0.01. Owing to the atomic weights of these substances, and the very small quantities being considered, the same limit hardly differs from that of 0.01 per cent. by weight of sulphuretted hydrogen or of phosphine--it being always recollected that the sulphur and phosphorus do not necessarily exist in the gas as simple hydrides. Keppeler, however, has suggested the higher figure of 0.15 milligramme of either sulphur or phosphorus per litre of acetylene (=0.066 grain per cubic foot) for the maximum amount of these impurities permissible in purified acetylene. He adopts this standard on the basis of the results of observations of the amounts of sulphur and phosphorus present in the gas issuing from a purifier charged with heratol at the moment when the last layer of the heratol is beginning to change colour. No limit has been given for the removal of the ammonia, partly because that impurity can more easily, and without concomitant disadvantage, be extracted entirely; and partly because it is usually removed in the washer and not in the true chemical purifier. According to Lewes, the maximum amount of ammonia found in the acetylene coming from a dripping generator is 0.95 gramme per litre, while in carbide-to-water gas it is 0.16 gramme: 417 and 70.2 grains per cubic foot respectively. Rossel and Landriset have found 4 milligrammes (1.756 grains [Footnote: Milligrammes per litre; grains per cubic foot. It is convenient to remember that since 1 cubic foot of water weighs 62.321 x 16 - 997.14 avoirdupois ounces, grammes per litre are approximately equal to oz. per cubic foot; and grammes per cubic metre to oz. per 1000 cubic feet.]) to be the maximum in water-to-carbide gas, and none to occur in carbide-to-water acetylene. Rossel and Landriset return the minimum proportion of sulphur, calculated as H_2S, found in the gaseous state in acetylene when the carbide has not been completely flooded with water at 1.18 milligrammes per litre, or 0.52 grain per cubic foot; and the corresponding maxima at 1.9 milligrammes, or 0.84 grain. In carbide-to- water gas, the similar maxima are 0.23 milligramme or 0.1 grain. As already stated, the highest proportion of phosphine yet found in acetylene is 2.3 per cent. (Lewes), which is equal to 32.2 milligrammes of PH_3 per litre or 14.13 grains per cubic foot (Polis); but this sample dated from 1897. Eitner and Keppeler record the minimum proportion of phosphorus, calculated as PH_3, found in crude acetylene, as 0.45 milligramme per litre, and the maximum as 0.89 milligramme per litre; in English terms these figures are 0.2 and 0.4 grain per cubic foot. On an average, however, British and Continental carbide of the present day may be said to give a gas containing 0.61 milligramme of phosphorus calculated as PH_3 per litre and 0.75 milligramme of sulphur calculated as H_2S. In other units these figures are equal to 0.27 grain of PH_3 and 0.33 grain of H_2S per 1 cubic foot, or to 0.041 per cent. by volume of PH_3 and 0.052 per cent. of H_2S. Yields of phosphorus and sulphur much higher than these will be found in the journals and books, but such analytical data were usually obtained in the years 1896-99, before the manufacture of calcium carbide had reached its present degree of systematic control. A commercial specimen of carbide was seen by one of the authors as late as 1900 which gave an acetylene containing 1.12 milligramme of elementary sulphur per litre, i.e., 0.096 per cent, by volume, or 0.102 per cent, by volume of H_2S; but the phosphorus showed the low figure of 0.36 milligramme per litre (0.031 per cent, of P or 0.034 per cent, of PH_3 by volume). The British Acetylene Association's regulations relating to carbide of calcium (_vide_ Chap. XIV.) contain a clause to the effect that "carbide which, when properly decomposed, yields acetylene containing from all phosphorus compounds therein more than 0.05 per cent, by volume of phosphoretted hydrogen, may be refused by the buyer." This limit is equivalent to 0.74 milligramme of phosphorus calculated as PH_3 per litre. A latitude of 0.01 per cent, is, however, allowed for the analysis, so that the ultimate limit on which carbide could be rejected is: 0.06 volume per cent. of PH_3, or 0.89 milligramme of phosphorus per litre. The existence in appreciable quantity of combined silicon as a normal impurity in acetylene seems still open to doubt. Calcium carbide frequently contains notable quantities of iron and other silicides; but although these bodies are decomposed by acids, yielding hydrogen silicide, or siliciuretted hydrogen, they are not attacked by plain water. Nevertheless Wolff and Gerard have found hydrogen silicide in crude acetylene, and Lewes looks upon it as a common impurity in small amounts. When it occurs, it is probably derived, as Vigouroux has suggested, from "alloys" of silicon with calcium, magnesium, and aluminium in the carbide. The metallic constituents of these substances would naturally be attacked by water, evolving hydrogen; and the hydrogen, in its nascent state, would probably unite with the liberated silicon to form hydrogen silicide. Many authorities, including Keppeler, have virtually denied that silicon compounds exist in crude acetylene, while the proportion 0.01 per cent. has been given by other writers as the maximum. Caro, however, has stated that the crude gas almost invariably contains silicon, sometimes in very small quantities, but often up to the limit of 0.8 per cent.; the failure of previous investigators to discover it being due to faulty analytical methods. Caro has seen one specimen of (bad) carbide which gave a spontaneously inflammable gas although it contained only traces of phosphine; its inflammability being caused by 2.1 per cent. of hydrogen silicide. Practically speaking, all the foregoing remarks made about phosphine apply equally to hydrogen silicide: it burns to solid silicon oxide (silica) at the burners, is insoluble in water, and is spontaneously inflammable when alone or only slightly diluted, but never occurs in good carbide in sufficient proportion to render the acetylene itself inflammable. According to Caro the silicon may be present both as hydrogen silicide and as silicon "compounds." A high temperature in the generator will favour the production of the latter; an apparatus in which the gas is washed well in lime-water will remove the bulk of the former. Fraenkel has found that magnesium silicide is not decomposed by water or an alkaline solution, but that dilute hydrochloric acid acts upon it and spontaneously inflammable hydrogen silicide results. If it may be assumed that the other silicides in commercial calcium carbide also behave in this manner it is plain that hydrogen silicide cannot occur in crude acetylene unless the gas is supposed to be hurried out of the generator before the alkaline water therein has had time to decompose any traces of the hydrogen silicide which is produced in the favouring conditions of high temperature sometimes prevailing. Mauricheau-Beaupré has failed to find silica in the products of combustion of acetylene from carbide of varying degrees of purity. He found, however, that a mixture of strong nitric and hydrochloric acids (_aqua regia_), if contaminated with traces of phosphoric acid, dissolved silica from the glass of laboratory vessels. Consequently, since phosphoric acid results from the phosphine in crude acetylene when the gas is passed through aqua regia, silica may be found on subsequently evaporating the latter. But this, silica, he found, was derived from the glass and not through the oxidation of silicon compounds in the acetylene. It is possible that some of the earlier observers of the occurrence of silicon compounds in crude acetylene may have been misled by the solution of silica from the glass vessels used in their investigations. The improbability of recognisable quantities of silicon compounds occurring in acetylene in any ordinary conditions of generation is demonstrated by a recent study by Fraenkel of the composition of the deposit produced on reflectors exposed to the products of combustion of a sample of acetylene which afforded a haze when burnt. The deposit contained 51.07 per cent. of phosphoric acid, but no silica. The gas itself contained from 0.0672 to 0.0837 per cent. by volume of phosphine. PURIFYING MATERIALS.--When acetylene first began to be used as a domestic illuminant, most generator builders denied that there was any need for the removal of these carbide impurities from the gas, some going so far as to assert that their apparatus yielded so much purer an acetylene than other plant, where purification might be desirable, that an addition of a special purifier was wholly unnecessary. Later on the more responsible members of the trade took another view, but they attacked the problem of purification in a perfectly empirical way, either employing some purely mechanical scrubber filled with some moist or dry porous medium, or perhaps with coke or the like wetted with dilute acid, or they simply borrowed the processes adopted in the purification of coal-gas. At first sight it might appear that the more simple methods of treating coal-gas should be suitable for acetylene; since the former contains two of the impurities--sulphuretted hydrogen and ammonia--characteristic of crude acetylene. After removing the ammonia by washing with water, therefore, it was proposed to extract the sulphur by passing the acetylene through that variety of ferric hydroxide (hydrated oxide of iron) which is so serviceable in the case of coal-gas. The idea, however, was quite unsound: first, because it altogether ignores the phosphorus, which is the most objectionable impurity in acetylene, but is not present in coal- gas; secondly, because ferric hydroxide is used on gasworks to extract in a marketable form the sulphur which occurs as sulphuretted hydrogen, and true sulphuretted hydrogen need not exist in well-generated and well- washed acetylene to any appreciable extent; thirdly, because ferric hydroxide is not employed by gasmakers to remove sulphur compounds (this is done with lime), being quite incapable of extracting them, or the analogous sulphur compounds of crude acetylene. About the same time three other processes based on somewhat better chemical knowledge were put forward. Pictet proposed leading the gas through a strong solution of calcium chloride and then through strong sulphuric acid, both maintained at a temperature of -20° to -40° C., finally washing the gas in a solution of some lead salt. Proof that such treatment would remove phosphorus to a sufficient degree is not altogether satisfactory; but apart from this the necessity of maintaining such low temperatures, far below that of the coldest winter's night, renders the idea wholly inadmissible for all domestic installations. Willgerodt suggested removing sulphuretted hydrogen by means of potassium hydroxide (caustic potash), then absorbing the phosphine in bromine water. For many reasons this process is only practicable in the laboratory. Bergé and Reychler proposed extracting both sulphuretted hydrogen and phosphine in an acid solution of mercuric chloride (corrosive sublimate). The poisonousness of this latter salt, apart from all other objections, rules such a method out. BLEACHING POWDER.--The next idea, first patented by Smith of Aberdeen, but fully elaborated by Lunge and Cedercreutz, was to employ bleaching- powder [Footnote: Bleaching-powder is very usually called chloride of lime; but owing to the confusion which is constantly arising in the minds of persons imperfectly acquainted with chemistry between chloride of lime and chloride of calcium--two perfectly distinct bodies--the less ambiguous expression "bleaching-powder" will be adopted here.] either in the solid state or as a liquid extract. The essential constituent of bleaching-powder from the present aspect is calcium hypochlorite, which readily oxidises sulphuretted hydrogen, and more particularly phosphine, converting them into sulphuric and phosphoric acids, while the acetylene is practically unattacked. In simple purifying action the material proved satisfactory; but since high-grade commercial bleaching-powder contains some free chlorine, or some is set free from it in the purifier under the influence of the passing gas, the issuing acetylene was found to contain chlorine, free or combined; and this, burning eventually to hydrochloric acid, is hardly less harmful than the original sulphur compounds. Moreover, a mixture of acetylene, chlorine, and air is liable to catch fire of itself when exposed to bright sunlight; and therefore the use of a bleaching-powder purifier, or rather the recharging thereof, was not unattended by danger in the early days. To overcome these defects, the very natural process was adopted of diluting the bleaching-powder, such diluent also serving to increase the porosity of the material. A very unsuitable substance, however, was selected for the purpose, viz., sawdust, which is hygroscopic organic, and combustible. Owing to the exothermic chemical action between the impurities of the acetylene and the bleaching-powder, the purifying mass became heated; and thus not only were the phenomena found in a bad generator repeated in the purifying vessel, but in presence of air and light (as in emptying the purifier), the reaction proceeded so rapidly that the heat caused inflammation of the sawdust and the gas, at least on one occasion an actual fire taking place which created much alarm and did some little damage. For a time, naturally, bleaching-powder was regarded as too dangerous a material to be used for the purification of crude acetylene; but it was soon discovered that danger could be avoided by employing the substance in a proper way. HERATOL, FRANKOLINE, ACAGINE AND PURATYLENE.--Setting aside as unworthy of attention certain compositions offered as acetylene purifying materials whose constitution has not been divulged or whose action has not been certified by respectable authority, there are now three principal chemical reagents in regular use. Those are chromic acid, cuprous chloride (sub- or proto-chloride of copper), and bleaching- powder. Chromic acid is employed in the form of a solution acidified with acetic or hydrochloric acid, which, in order to obtain the advantages (_see_ below) attendant upon the use of a solid purifying material, is absorbed in that highly porous and inert description of silica known as infusorial earth or "kieselguhr." This substance was first recommended by Ullmann, and is termed commercially "heratol" As sold it contains somewhere about 136 grammes of chromic acid per kilo. Cuprous chloride is used as a solution in strong hydrochloric acid mixed with ferric chloride, and similarly absorbed in kieselguhr. From the name of its proposer, this composition is called "frankoline." It will be shown in Chapter VI. that the use of metallic copper in the construction of acetylene apparatus is not permissible or judicious, because the gas is liable to form therewith an explosive compound known as copper acetylide; it might seem, therefore, that the employment of a copper salt for purification courts accident. The objection is not sound, because the acetylide is not likely to be produced except in the presence of ammonia; and since frankoline is a highly acid product, the ammonia is converted into its chloride before any copper acetylide can be produced. As a special acetylene purifier, bleaching-powder exists in at least two chief modifications. In one, known as "acagine," it is mixed with 15 per cent. of lead chromate, and sometimes with about the same quantity of barium sulphate; the function of the latter being simply that of a diluent, while to the lead chromate is ascribed by its inventor (Wolff) the power of retaining any chlorine that may be set free from the bleaching-powder by the reduction of the chromic acid. The utility of the lead chromate in this direction has always appeared doubtful; and recently Keppeler has argued that it can have no effect upon the chlorine, inasmuch as in the spent purifying material the lead chromate may be found in its original condition unchanged. The second modification of bleaching-powder is designated "puratylene," and contains calcium chloride and quick or slaked lime. It is prepared by evaporating to dryness under diminished pressure solutions of its three ingredients, whereby the finished material is given a particularly porous nature. It will be observed that both heratol and frankoline are powerfully acid, whence it follows they are capable of extracting any ammonia that may enter the purifier; but for the same reason they are liable to act corrosively upon any metallic vessel in which they are placed, and they therefore require to be held in earthenware or enamelled receivers. But since they are not liquid, the casing of the purifier can be safely constructed of steel or cast iron. Puratylene also removes ammonia by virtue of the calcium chloride in it. Acagine would probably pass the ammonia; but this is no real objection, as the latter can be extracted by a preliminary washing in water. Heratol changes, somewhat obscurely, in colour as it becomes spent, its original orange tint, due to the chromic acid, altering to a dirty green, characteristic of the reduced salts of chromium oxide. Frankoline has been asserted to be capable of regeneration or revivification, _i.e._, that when spent it may be rendered fit for further service by being exposed to the air for a time, as is done with gas oxide; this, however, may be true to some extent with the essential constituents of frankoline, but the process is not available with the commercial solid product. Of all these materials, heratol is the most complete purifier of acetylene, removing phosphorus and sulphur most rapidly and thoroughly, and not appreciably diminishing in speed or efficiency until its chromic acid is practically quite used up. On the other hand, heratol does act upon pure acetylene to some extent; so that purifiers containing it should be small in size and frequently recharged. In one of his experiments Keppeler found that 13 per cent. of the chromic acid in heratol was wasted by reacting with acetylene. As this waste of chromic acid involves also a corresponding loss of gas, small purifiers are preferable, because at any moment they only contain a small quantity of material capable of attacking the acetylene itself. Frankoline is very efficacious as regards the phosphorus, but it does not wholly extract the sulphur, leaving, according to Keppeler, from 0.13 to 0.20 gramme of the latter in every cubic metre of the gas. It does not attack acetylene itself; and if, owing to its free hydrochloric acid, it adds any acid vapours to the purified gas, these vapours may be easily removed by a subsequent passage through a vessel containing lime or a carbide drier. Both being essentially bleaching-powder, acagine and puratylene are alike in removing phosphorus to a satisfactory degree; but they leave some sulphur behind. Acagine evidently attacks acetylene to a slight extent, as Keppeler has found 0.2 gramme of chlorine per cubic metre in the issuing gas. Although some of these materials attack acetylene slightly, and some leave sulphur in the purified gas, they may be all considered reasonably efficient from the practical point of view; for the loss of true acetylene is too small to be noticeable, and the quantity of sulphur not extracted too trifling to be harmful or inconvenient. They may be valued, accordingly, mainly by their price, proper allowance being made for the quantity of gas purified per unit weight of substance taken. This quantity of gas must naturally vary with the proportion of phosphorus and sulphur in the crude acetylene; but on an average the composition of unpurified gas is what has already been given above, and so the figures obtained by Keppeler in his investigation of the subject may be accepted. In the annexed table these are given in two forms: (1) the number of litres of gas purified by 1 kilogramme of the substance, (2) the number of cubic feet purified per lb. It should be noted that the volumes of gas refer to a laboratory degree of purification; in practice they may all be increased by 10 or possibly 20 per cent. _________________________________________________ | | | | | | Litres | Cubic Feet | | | per Kilogramme. | per Lb. | |______________|___________________|______________| | | | | | Heratol | 5,000 | 80 | | Frankoline | 9,000 | 144 | | Puratylene | 10,000 | 160 | | Acagine | 13,000 | 208 | |______________|___________________|______________| Another method of using dry bleaching-powder has been proposed by Pfeiffer. He suggests incorporating it with a solution of some lead salt, so that the latter may increase the capacity of the calcium hypochlorite to remove sulphur. Analytical details as to the efficiency of this process have not been given. During 1901 and 1902 Bullier and Maquenne patented a substance made by mixing bleaching-powder with sodium sulphate, whereby a double decomposition occurs, sodium hypochlorite, which is equally efficient with calcium hypochlorite as a purifying material, being produced together with calcium sulphate, which, being identical with plaster of Paris, sets into a solid mass with the excess of water present, and is claimed to render the whole more porous. This process seemed open to objection, because Blagden had shown that a solution of sodium hypochlorite was not a suitable purifying reagent in practice, since it was much more liable to add chlorine to the gas than calcium hypochlorite. The question how a solidified modification of sodium hypochlorite would behave in this respect has been investigated by Keppeler, who found that the Bullier and Maquenne material imparted more chlorine to the gas which had traversed it than other hypochlorite purifying agents, and that the partly foul material was liable to cause violent explosions. About the same time Rossel and Landriset pointed out that purification might be easily effected in all generators of the carbide-to-water pattern by adding to the water of the generator itself a quantity of bleaching-powder equivalent to 5 to 20 grammes for every 1 kilogramme of carbide decomposed, claiming that owing to the large amount of liquid present, which is usually some 4 litres per kilogramme of carbide (0.4 gallon per lb.), no nitrogen chloride could be produced, and that owing to the dissolved lime in the generator, chlorine could not be added to the gas. The process is characterised by extreme simplicity, no separate purifier being needed, but it has been found that an introduction of bleaching-powder in the solid condition is liable to cause an explosive combination of acetylene and chlorine, while the use of a solution is attended by certain disadvantages. Granjon has proposed impregnating a suitable variety of wood charcoal with chlorine, with or without an addition of bleaching-powder; then grinding the product to powder, and converting it into a solid porous mass by the aid of cement. The material is claimed to last longer than ordinary hypochlorite mixtures, and not to add chlorine to the acetylene. SUBSIDIARY PURIFYING MATERIALS.--Among minor reagents suggested as purifying substances for acetylene may be mentioned potassium permanganate, barium peroxide, potassium bichromate, sodium plumbate and arsenious oxide. According to Benz the first two do not remove the sulphuretted hydrogen completely, and oxidise the acetylene to some extent; while potassium bichromate leaves some sulphur and phosphorus behind in the gas. Sodium plumbate has been suggested by Morel, but it is a question whether its action on the impurities would not be too violent and whether it would be free from action on the acetylene itself. The use of arsenious oxide dissolved in a strong acid, and the solution absorbed in pumice or kieselguhr has been protected by G. F. Jaubert. The phosphine is said to combine with the arsenic to form an insoluble brownish compound. In 1902 Javal patented a mixture of 1 part of potassium permanganate, 5 of "sulphuric acid," and 1 of water absorbed in 4 parts of infusorial earth. The acid constantly neutralised by the ammonia of the crude gas is as constantly replaced by fresh acid formed by the oxidation of the sulphuretted hydrogen; and this free acid, acting upon the permanganate, liberates manganese peroxide, which is claimed to destroy the phosphorus and sulphur compounds present in the crude acetylene. ÉPURÈNE.--A purifying material to which the name of épurène has been given has been described, by Mauricheau-Beaupré, as consisting of a mixture of ferric chloride and ferric oxide in the proportion of 2 molecules, or 650 parts, of the former with one molecule, or 160 parts, of the latter, together with a suitable quantity of infusorial earth. In the course of preparation, however, 0.1 to 0.2 per cent. of mercuric chloride is introduced into the material. This mercuric chloride is said to form an additive compound with the phosphine of the crude acetylene, which compound is decomposed by the ferric chloride, and the mercuric chloride recovered. The latter therefore is supposed to act only as a carrier of the phosphine to the ferric chloride and oxide, by which it is oxidised according to the equation: 8Fe_2Cl_6 + 4Fe_2O_3 + 3PH_3 = 12Fe_2Cl_4 + 3H_3PO_4. Thus the ultimate products are phosphoric acid and ferrous chloride, which on exposure to air is oxidised to ferric chloride and oxide. It is said that this revivification of the fouled or spent épurène takes place in from 20 to 48 hours when it is spread in the open in thin layers, or it may be partially or wholly revivified _in situ_ by adding a small proportion of air to the crude acetylene as it enters the purifier. The addition of 1 to 2 per cent. of air, according to Mauricheau-Beaupré, suffices to double the purifying capacity of one charge of the material, while a larger proportion would achieve its continuous revivification. Épurène is said to purify 10,000 to 11,000 litres of crude acetylene per kilogramme, or, say, 160 to 176 cubic feet per pound, when the acetylene contains on the average 0.05 per cent, by volume of phosphine. For employment in all acetylene installations smaller than those which serve complete villages, a solid purifying material is preferable to a liquid one. This is partly due to the extreme difficulty of subdividing a stream of gas so that it shall pass through a single mass of liquid in small enough bubbles for the impurities to be removed by the time the gas arrives at the surface. This time cannot be prolonged without increasing the depth of liquid in the vessel, and the greater the depth of liquid, the more pressure is consumed in forcing the gas through it. Perfect purification by means of fluid reagents unattended by too great a consumption of pressure is only to be effected by a mechanical scrubber such as is used on coal-gas works, wherein, by the agency of external power, the gas comes in contact with large numbers of solid surfaces kept constantly wetted; or by the adoption of a tall tower filled with porous matter or hollow balls over which a continuous or intermittent stream of the liquid purifying reagent is made to trickle, and neither of these devices is exactly suited to the requirements of a domestic acetylene installation. When a solid material having a proper degree of porosity or aggregation is selected, the stream of gas passing through it is broken up most thoroughly, and by employing several separate layers of such material, every portion of the gas is exposed equally to the action of the chemical reagent by the time the gas emerges from the vessel. The amount of pressure so consumed is less than that in a liquid purifier where much fluid is present; but, on the other hand, the loss of pressure is absolutely constant at all times in a liquid purifier, provided the head of liquid is maintained at the same point. A badly chosen solid purifying agent may exhibit excessive pressure absorption as it becomes partly spent. A solid purifier, moreover, has the advantage that it may simultaneously act as a drier for the gas; a liquid purifier, in which the fluid is mainly water, obviously cannot behave in a similar fashion For thorough purification it is necessary that the gas shall actually stream through the solid material; a mere passage over its surface is neither efficient nor economical of material. DISPOSITION OF PURIFYING MATERIAL.--Although much has been written, and some exaggerated claims made, about the maximum, volume of acetylene a certain variety of purifying material will treat, little has been said about the method in which such a material should be employed to obtain the best results. If 1 lb. of a certain substance will purify 200 cubic feet of normal crude acetylene, that weight is sufficient to treat the gas evolved from 40 lb. of carbide; but it will only do so provided it is so disposed in the purifier that the gas does not pass through it at too high a speed, and that it is capable of complete exhaustion. In the coal- gas industry it is usually assumed that four layers of purifying material, each having a superficial area of 1 square foot, are the minimum necessary for the treatment of 100 cubic feet of gas per hour, irrespective of the nature of the purifying material and of the impurity it is intended to extract. If there is any sound basis for this generalization, it should apply equally to the purification of acetylene, because there is no particular reason to imagine that the removal of phosphine by a proper substance should occur at an appreciably different speed from the removal of carbon dioxide, sulphuretted hydrogen, and carbon bisulphide by lime, ferric oxide, and sulphided lime respectively, Using the coal gas figures, then, for every 10 cubic feet of acetylene generated per hour, a superficial area of (4 x 144 / 10) 57.6 square inches of purifying material is required. In the course of Keppeler's research upon different purifying materials it is shown that 400 grammes of heratol, 360 grammes of frankoline, 250 grammes of acagine, and 230 grammes of puratylene each occupy a space of 500 cubic centimetres when loosely loaded into a purifying vessel, and from these data, the following table has been calculated: __________________________________________________________ | | | | | | | Weight | Weight | Cubic Inches | | | per Gallon | per Cubic Foot | Occupied | | | in Lbs. | in Lbs. | per Lb. | |_____________|____________|________________|______________| | | | | | | Water | 10.0 | 62.321 | 27.73 | | Heratol | 8.0 | 49.86 | 31.63 | | Frankoline | 7.2 | 41.87 | 38.21 | | Acagine | 6.0 | 31.16 | 55.16 | | Puratylene | 4.6 | 28.67 | 60.28 | |_____________|____________|________________|______________| As regards the minimum weight of material required, data have been given by Pfleger for use with puratylene. He states that 1 Kilogramme of that substance should be present for every 100 litres of crude acetylene evolved per hour, 4 kilogrammes being the smallest quantity put into the purifier. In English units these figures are 1 lb. per 1.5 cubic feet per hour, with 9 lb. as a minimum, which is competent to treat 1.1 cubic feet of gas per hour. Thus it appears that for the purification of the gas coming from any generator evolving up to 14 cubic feet of acetylene per hour a weight of 9 lb of puratylene must be charged into the purifier, which will occupy (60.28 / 9) 542 cubic inches of space; and it must be so spread out as to present a total superficial area of (4 x 144 x 14 / 100) 80.6 square inches to the passing gas. It follows, therefore, that the material should be piled to a depth of (542 / 80.6) 6.7 inches on a support having an area of 80.6 square inches; but inasmuch as such a depth is somewhat large for a small vessel, and as several layers are better than one, it would be preferable to spread out these 540 cubic inches of substance on several supports in such a fashion that a total surface of 80.6 square inches or upwards should be exhibited. These figures may obviously be manipulated in a variety of ways for the design of a purifying vessel; but, to give an example, if the ordinary cylindrical shape be adopted with four circular grids, each having a clear diameter of 8 inches (_i.e._, an area of 50.3 square inches), and if the material is loaded to a depth of 3 inches on each, there would be a total volume of (50.3 x 3 x 4) = 604 cubic inches of puratylene in the vessel, and it would present a total area of (50.3 x 4) = 201 square inches to the acetylene. At Keppeler's estimation such an amount of puratylene should weigh roughly 10 lb., and should suffice for the purification of the gas obtained from 320 lb. of ordinary carbide; while, applying the coal-gas rule, the total area of 201 square inches should render such a vessel equal to the purification of acetylene passing through it at a speed not exceeding (201 / 5.76) = 35 cubic feet per hour. Remembering that it is minimum area in square inches of purifying material that must govern the speed at which acetylene may be passed through a purifier, irrespective probably of the composition of the material; while it is the weight of material which governs the ultimate capacity of the vessel in terms of cubic feet of acetylene or pounds of carbide capable of purification, these data, coupled with Keppeler's efficiency table, afford means for calculating the dimensions of the purifying vessel to be affixed to an installation of any desired number of burners. There is but little to say about the design of the vessel from the mechanical aspect. A circular horizontal section is more likely to make for thorough exhaustion of the material. The grids should be capable of being lifted out for cleaning. The lid may be made tight either by a clamp and rubber or leather washer, or by a liquid seal. If the purifying material is not hygroscopic, water, calcium chloride solution, or dilute glycerin may be used for sealing purposes; but if the material, or any part of it, does absorb water, the liquid in the seal should be some non-aqueous fluid like lubricating oil. Clamped lids are more suitable for small purifiers, sealed lids for large vessels. Care must be taken that condensation products cannot collect in the purifying vessel. If a separate drying material is employed in the same purifier the space it takes must be considered separately from that needed by the active chemical reagent. When emptying a foul purifier it should be recollected that the material may be corrosive, and being saturated with acetylene is likely to catch fire in presence of a light. Purifiers charged with heratol are stated, however, to admit of a more rapid flow of the gas through them than that stated above for puratylene. The ordinary allowance is 1 lb. of heratol for every cubic foot per hour of acetylene passing, with a minimum charge of 7 lb. of the material. As the quantity of material in the purifier is increased, however, the flow of gas per hour may be proportionately increased, _e.g._, a purifier charged with 132 lb. of heratol should purify 144 cubic feet of acetylene per hour. In the systematic purification of acetylene, the practical question arises as to how the attendant is to tell when his purifiers approach exhaustion and need recharging; for if it is undesirable to pass crude gas into the service, it is equally undesirable to waste so comparatively expensive a material as a purifying reagent. In Chapter XIV. it will be shown that there are chemical methods of testing for the presence, or determining the proportion, of phosphorus and sulphur in acetylene; but these are not suitable for employment by the ordinary gas-maker. Heil has stated that the purity of the gas may be judged by an inspection of its atmospheric flame as given by a Bunsen burner. Pure acetylene gives a perfectly transparent moderately dark blue flame, which has an inner cone of a pale yellowish green colour; while the impure gas yields a longer flame of an opaque orange-red tint with a bluish red inner zone. It should be noted, however, that particles of lime dust in the gas may cause the atmospheric flame to be reddish or yellowish (by presence of calcium or sodium) quite apart from ordinary impurities; and for various other reasons this appearance of the non-luminous flame is scarcely to be relied upon. The simplest means of ascertaining definitely whether a purifier is sufficiently active consists in the use of the test-papers prepared by E. Merck of Darmstadt according to G. Keppeler's prescription. These papers, cut to a convenient size, are put up in small books from which they may be torn one at a time. In order to test whether gas is sufficiently purified, one of the papers is moistened with hydrochloric acid of 10 per cent. strength, and the gas issuing from a pet-cock or burner orifice is allowed to impinge on the moistened part. The original black or dark grey colour of the paper is changed to white if the gas contains a notable amount of impurity, but remains unchanged if the gas is adequately purified. The paper consists of a specially prepared black porous paper which has been dipped in a solution of mercuric chloride (corrosive sublimate) and dried. Moistening the paper with hydrochloric acid provides in a convenient form for application Bergé's solution for the detection of phosphine (_vide_ Chapter XIV.). The Keppeler test-papers turn white when the gas contains either ammonia, phosphine, siliciuretted hydrogen, sulphuretted hydrogen or organic sulphur compounds, but with carbon disulphide the change is slow. Thus the paper serves as a test for all the impurities likely to occur in acetylene. The sensitiveness of the test is such that gas containing about 0.15 milligramme of sulphur, and the same amount of phosphorus, per litre (= 0.0655 grain per cubic foot) imparts in five minutes a distinct white mark to the moistened part of the paper, while gas containing 0.05 milligramme of sulphur per litre (= 0.022 grain per cubic foot) gives in two minutes a dull white mark visible only by careful inspection. If, therefore, a distinct white mark appears on moistened Keppeler paper when it is exposed for five minutes to a jet of acetylene, the latter is inadequately purified. If the gas has passed through a purifier, this test indicates that the material is not efficient, and that the purifier needs recharging. The moistening of the Keppeler paper with hydrochloric acid before use is essential, because if not acidified the paper is marked by acetylene itself. The books of Keppeler papers are put up in a case which also contains a bottle of acid for moistening them as required and are obtainable wholesale of E. Merek, 16 Jewry Street, London, E.C., and retail of the usual dealers in chemicals. If Keppeler's test-papers are not available, the purifier should be recharged as a matter of routine as soon as a given quantity of carbide--proportioned to the purifying capacity of the charge of purifying material--has been used since the last recharging. Thus the purifier may conveniently contain enough material to purify the gas evolved from two drums of carbide, in which case it would need recharging when every second drum of carbide is opened. REGULATIONS AS TO PURIFICATION.--The British Acetylene Association has issued the following set of regulations as to purifying material and purifiers for acetylene: Efficient purifying material and purifiers shall comply with the following requirements: (1) The purifying material shall remove phosphorus and sulphur compounds to a commercially satisfactory degree; _i.e._, not to a greater degree than will allow easy detection of escaping gas through its odour. (2) The purifying material shall not yield any products capable of corroding the gas-mains or fittings. (3) The purifying material shall, if possible, be efficient as a drying agent, but the Association does not consider this an absolute necessity. (4) The purifying material shall not, under working conditions, be capable of forming explosive compounds or mixtures. It is understood, naturally, that this condition does not apply to the unavoidable mixture of acetylene and air formed when recharging the purifier. (5) The apparatus containing the purifying material shall be simple in construction, and capable of being recharged by an inexperienced person without trouble. It shall be so designed as to bring the gas into proper contact with the material. (6) The containers in purifiers shall be made of such materials as are not dangerously affected by the respective purifying materials used. (7) No purifier shall be sold without a card of instructions suitable or hanging up in some convenient place. Such instructions shall be of the most detailed nature, and shall not presuppose any expert knowledge whatever on the part of the operator. Reference also to the abstracts of the official regulations as to acetylene installations in foreign countries given in Chapter IV. will show that they contain brief rules as to purifiers. DRYING.--It has been stated in Chapter III. that the proper position for the chemical purifiers of an acetylene plant is after the holder; and they therefore form the last items in the installation unless a "station" governor and meter are fitted. It is therefore possible to use them also to remove the moisture in the gas, if a material hygroscopic in nature is employed to charge them. This should be true more particularly with puratylene, which contains a notable proportion of the very hygroscopic body calcium chloride. If a separate drier is desirable, there are two methods of charging it. It may be filled either with some hygroscopic substance such as porous calcium chloride or quicklime in very coarse powder, which retains the water by combining with it; or the gas may be led through a vessel loaded with calcium carbide, which will manifestly hold all the moisture, replacing it by an equivalent quantity of (unpurified) acetylene. The objection is sometimes urged against this latter method, that it restores to the gas the nauseous odour and the otherwise harmful impurities it had more or less completely lost in the purifiers; but as regards the first point, a nauseous odour is not, as has previously been shown, objectionable in itself, and as regards the second, the amount of impurities added by a carbide drier, being strictly limited by the proportion of moisture in the damp gas, is too small to be noticeable at the burners or elsewhere. As is the case with purification, absolute removal of moisture is not called for; all that is needed is to extract so much that the gas shall never reach its saturation-point in the inaccessible parts of the service during the coldest winter's night. Any accessible length of main specially exposed to cold may be safeguarded by itself; being given a steady fall to a certain point (preferably in a frost-free situation), and there provided with a collecting-box from which the deposited liquid can be removed periodically with a pump or otherwise. FILTRATION.--The gas issuing from the purifier or drier is very liable to hold in suspension fine dust derived from the purifying or drying material used. It is essential that thin dust should be abstracted before the gas reaches the burners, otherwise it will choke the orifices and prevent them functioning properly. Consequently the gas should pass through a sufficient layer of filtering material after it has traversed the purifying material (and drier if one is used). This filtering material may be put either as a final layer in the purifier (or drier), or in a separate vessel known as a filter. Among filtering materials in common use may be named cotton-wool, fine canvas or gauze, felt and asbestos-wool. The gas must be fairly well dried before it enters the filter, otherwise the latter will become choked with deposited moisture, and obstruct the passage of the gas. Having now described the various items which go to form a well-designed acetylene installation, it may be useful to recapitulate briefly, with the object of showing the order in which they should be placed. From the generator the gas passes into a condenser to cool it and to remove any tarry products and large quantities of water. Next it enters a washing apparatus filled with water to extract water-soluble impurities. If the generator is of the carbide-to-water pattern, the condenser may be omitted, and the washer is only required to retain any lime froth and to act as a water-seal or non-return valve. If the generator does not wash the gas, the washer must be large enough to act efficiently as such, and between it and the condenser should be put a mechanical filter to extract any dust. From the washer the acetylene travels to the holder. From the holder it passes through one or two purifiers, and from there travels to the drier and filter. If the holder does not throw a constant pressure, or if the purifier and drier are liable to cause irregularities, a governor or pressure regulator must be added after the drier. The acetylene is then ready to enter the service; but a station meter (the last item in the plant) is useful as giving a means of detecting any leak in the delivery-pipes and in checking the make of gas from the amount of carbide consumed. If the gas is required for the supply of a district, a station meter becomes quite necessary, because the public lamps will be fed with gas at a contract rate, and without the meter there would be no control over the volume of acetylene they consume. Where the gas finally leaves the generating-house, or where it enters the residence, a full-way stopcock should be put on the main. GENERATOR RESIDUES.--According to the type of generator employed the waste product removed therefrom may vary from a dry or moist powder to a thin cream or milk of lime. Any waste product which is quite liquid in its consistency must be completely decomposed and free from particles of calcium carbide of sensible magnitude; in the case of more solid residues, the less fluid they are the greater is the improbability (or the less is the evidence) that the carbide has been wholly spent within the apparatus. Imperfect decomposition of the carbide inside the generator not only means an obvious loss of economy, but its presence among the residues makes a careful handling of them essential to avoid accident owing to a subsequent liberation of acetylene in some unsuitable, and perhaps closed, situation. A residue which is not conspicuously saturated with water must be taken out of the generator- house into the open air and there flooded with water, being left in some uncovered receptacle for a sufficient time to ensure all the acetylene being given off. A residue which is liquid enough to flow should be run directly from the draw-off cock of the generator through a closed pipe to the outside; where, if it does not discharge into an open conduit, the waste-pipe must be trapped, and a ventilating shaft provided so that no gas can blow back into the generator-house. DISPOSAL OF RESIDUES.--These residues have now to be disposed of. In some circumstances they can be put to a useful purpose, as will be explained in Chapter XII.; otherwise, and always perhaps on the small scale-- certainly always if the generator overheats the gas and yields tar among the spent lime--they must be thrown into a convenient place. It should be remembered that although methods of precipitating sewage by adding lime, or lime water, to it have frequently been used, they have not proved satisfactory, partly because the sludge so obtained is peculiarly objectionable in odour, and partly because an excess of lime yields an effluent containing dissolved lime, which among other disadvantages is harmful to fish. The plan of running the liquid residues of acetylene manufacture into any local sewerage system which may be found in the neighbourhood of the consumer's premises, therefore, is very convenient to the consumer; but is liable to produce complaints if the sewage is afterwards treated chemically, or if its effluent is passed untreated into a highly preserved river; and the same remark applies in a lesser degree if the residues are run into a private cesspool the liquid contents of which automatically flow away into a stream. If, however, the cesspool empties itself of liquid matter by filtration or percolation through earth, there can be no objection to using it to hold the lime sludge, except in so far as it will require more frequent emptying. On the whole, perhaps the best method of disposing of these residues is to run them into some open pit, allowing the liquid to disappear by evaporation and percolation, finally burying the solid in some spot where it will be out of the way. When a large carbide-to-water generator is worked systematically so as to avoid more loss of acetylene by solution in the excess of liquid than is absolutely necessary, the liquid residues coming from it will be collected in some ventilated closed tank where they can settle quietly. The clear lime-water will then be pumped back into the generator for further use, and the almost solid sludge will be ready to be carried to the pit where it is to be buried. Special care must be taken in disposing of the residues from a generator in which oil is used to control evolution of gas. Such oil floats on the aqueous liquid; and a very few drops spread for an incredible distance as an exceedingly thin film, causing those brilliant rainbow-like colours which are sometimes imagined to be a sign of decomposing organic matter. The liquid portions of these residues must be led through a pit fitted with a depending partition projecting below the level at which the water is constantly maintained; all the oil then collects on the first side of the partition, only water passing underneath, and the oil may be withdrawn and thrown away at intervals. CHAPTER VI THE CHEMICAL AND PHYSICAL PROPERTIES OF ACETYLENE It will only be necessary for the purpose of this book to indicate the more important chemical and physical properties of acetylene, and, in particular, those which have any bearing on the application of acetylene for lighting purposes. Moreover, it has been found convenient to discuss fully in other chapters certain properties of acetylene, and in regard to such properties the reader is referred to the chapters mentioned. PHYSICAL PROPERTIES.--Acetylene is a gas at ordinary temperatures, colourless, and, when pure, having a not unpleasant, so-called "ethereal" odour. Its density, or specific gravity, referred to air as unity, has been found experimentally by Leduc to be 0.9056. It is customary to adopt the value 0.91 for calculations into which the density of the gas enters (_vide_ Chapter VII.). The density of a gas is important not only for the determination of the size of mains needed to convey it at a given rate of flow under a given pressure, as explained in Chapter VII., but also because the volume of gas which will pass through small orifices in a given time depends on its density. According to Graham's well-known law of the effusion of gases, the velocity with which a gas effuses varies directly as the square root of the difference of pressure on the two sides of the opening, and inversely as the square root of the density of the gas. Hence it follows that the volume of gas which escapes through a porous pipe, an imperfect joint, or a burner orifice is, provided the pressure in the gas-pipe is the same, a function of the square root of the density of the gas. Hence this density has to be taken into consideration in the construction of burners, i.e., a burner required to pass a gas of high density must have a larger orifice than one for a gas of low density, if the rate of flow of gas is to be the same under the same pressure. This, however, is a question for the burner manufacturers, who already make special burners for gases of different densities, and it need not trouble the consumer of acetylene, who should always use burners devised for the consumption of that gas. But the Law of effusion indicates that the volume of acetylene which can escape from a leaky supply-pipe will be less than the volume of a gas of lower density, _e.g._, coal-gas, if the pressure in the pipe is the same for both. This implies that on an extensive distributing system, in which for practical reasons leakage is not wholly avoidable, the loss of gas through leakage will be less for acetylene than for coal-gas, given the same distributing pressure. If _v_ = the loss of acetylene from a distributing system and _v'_ = the loss of coal-gas from a similar system worked at the same pressure, both losses being expressed in volumes (cubic feet) per hour, and the coal-gas being assumed to have a density of 0.04, then (1) (_v_/_v'_) = (0.40 / 0.91)^(1/2) = 0.663 or, _v_ = 0.663_v'_, which signifies that the loss of acetylene by leakage under the same conditions of pressure, &c., will be only 0.663 times that of the loss of coal-gas. In practice, however, the pressures at which the gases are usually sent through mains are not identical, being greater in the case of acetylene than in that of coal-gas. Formula (1) therefore requires correction whenever the pressures are different, and calling the pressure at which the acetylene exists in the main _p_, and the corresponding pressure of the coal-gas _p'_, the relative losses by leakage are-- (2) (_v_/_v'_) = (0.40 / 0.91)^(1/2) x (_p_/_p'_)^(1/2) _v_ = 0.663_v'_ x (_p_/_p'_)^(1/2) It will be evident that whenever the value of the fraction (_p_/_p'_)^(1/2), is less than 1.5, _i.e._, whenever the pressure of the acetylene does not exceed double that of the coal-gas present in pipes of given porosity or unsoundness, the loss of acetylene will be less than that of coal-gas. This is important, especially in the case of large village acetylene installations, where after a time it would be impossible to avoid some imperfect joints, fractured pipes, &c., throughout the extensive distributing mains. The same loss of gas by leakage would represent a far higher pecuniary value with acetylene than with coal-gas, because the former must always be more costly per unit of volume than the latter. Hence it is important to recognise that the rate of leakage, _c�teris paribus_, is less with acetylene, and it is also important to observe the economical advantage, at least in terms of gas or calcium carbide, of sending the acetylene into the mains at as low a pressure as is compatible with the length of those mains and the character of the consumers' burners. As follows from what will be said in Chapter VII., a high initial pressure makes for economy in the prime cost of, and in the expense of laying, the mains, by enabling the diameter of those mains to be diminished; but the purchase and erection of the distributing system are capital expenses, while a constant expenditure upon carbide to meet loss by leakage falls upon revenue. The critical temperature of acetylene, _i.e._, the temperature below which an abrupt change from the gaseous to the liquid state takes place if the pressure is sufficiently high, is 37° C., and the critical pressure, _i.e._, the pressure under which that change takes place at that temperature, is nearly 68 atmospheres. Below the critical temperature, a lower pressure than this effects liquefaction of the gas, _i.e._, at 13.5° C. a pressure of 32.77 atmospheres, at 0° C., 21.53 atmospheres (Ansdell, _cf._ Chapter XI.). These data are of comparatively little practical importance, owing to the fact that, as explained in Chapter XI., liquefied acetylene cannot be safely utilised. The mean coefficient of expansion of gaseous acetylene between 0° C. and 100° C., is, under constant pressure, 0.003738; under constant volume, 0.003724. This means that, if the pressure is constant, 0.003738 represents the increase in volume of a given mass of gaseous acetylene when its temperature is raised one degree (C.), divided by the volume of the same mass at 0° C. The coefficients of expansion of air are: under constant pressure, 0.003671; under constant volume, 0.003665; and those of the simple gases (nitrogen, hydrogen, oxygen) are very nearly the same. Strictly speaking the table given in Chapter XIV., for facilitating the correction of the volume of gas measured over water, is not quite correct for acetylene, owing to the difference in the coefficients of expansion of acetylene and the simple gases for which the table was drawn up, but practically no appreciable error can ensue from its use. It is, however, for the correction of volumes of gases measured at different temperatures to one (normal) temperature, and, broadly, for determining the change of volume which a given mass of the gas will undergo with change of temperature, that the coefficient of expansion of a gas becomes an important factor industrially. Ansdell has found the density of liquid acetylene to range from 0.460 at -7° C. to 0.364 at +35.8° C., being 0.451 at 0° C. Taking the volume of the liquid at -7° as unity, it becomes 1.264 at 35.8°, and thence Ansdell infers that the mean coefficient of expansion per degree is 0.00489° for the total range of pressure." Assuming that the liquid was under the same pressure at the two temperatures, the coefficient of expansion per degree Centigrade would be 0.00605, which agrees more nearly with the figure 0.007 which is quoted, by Fouché As mentioned before, data referring to liquid (_i.e._, liquefied) acetylene are of no practical importance, because the substance is too dangerous to use. They are, however, interesting in so far as they indicate the differences in properties between acetylene converted into the liquid state by great pressure, and acetylene dissolved in acetone under less pressure; which differences make the solution fit for employment. It may be observed that as the solution of acetylene in acetone is a liquid, the acetylene must exist therein as a liquid; it is, in fact, liquid acetylene in a state of dilution, the diluent being an exothermic and comparatively stable body. The specific heat of acetylene is given by M. A. Morel at 0.310, though he has not stated by whom the value was determined. For the purpose of a calculation in Chapter III. the specific heat at constant pressure was assumed to be 0.25, which, in the absence of precise information, appears somewhat more probable as an approximation to the truth. The ratio (_k_ or C_p/C_v ) of the specific heat at constant pressure to that at constant volume has been found by Maneuvrier and Fournier to be 1.26; but they did not measure the specific heat itself. [Footnote: The ratio 1.26 _k_ or (C_p/C_v) has been given in many text-books as the value of the specific heat of acetylene, whereas this value should obviously be only about one-fourth or one-fifth of 1.26. By employing the ordinary gas laws it is possible approximately to calculate the specific heat of acetylene from Maneuvrier and Fournier's ratio. Taking the molecular weight of acetylene as 26, we have 26 C_p - 26 C_v = 2 cal., and C_p = 1.26 C_v. From this it follows that C_p, _i.e._, the specific heat at constant pressure of acetylene, should be 0.373.] It will be seen that this value for _k_ differs considerably from the corresponding ratio in the case of air and many common gases, where it is usually 1.41; the figure approaches more closely that given for nitrous oxide. For the specific heat of calcium carbide Carlson quotes the following figures: 0° 1000° 1500° 2000° 2500° 3000° 3500° 0.247 0.271 0.296 0.325 0.344 0.363 0.381 The molecular volume of acetylene is 0.8132 (oxygen = 1). According to the international atomic weights adopted in 1908, the molecular weight of acetylene is 26.016 if O = 16; in round numbers, as ordinarily used, it is 26. Employing the latest data for the weight of 1 litre of dry hydrogen and of dry normal air containing 0.04 per cent. of carbon dioxide at a temperature of 0° C. and a barometric pressure of 760 mm. in the latitude of London, viz., 0.089916 and 1.29395 grammes respectively (Castell-Evans), it now becomes possible to give the weight of a known volume of dry or moist acetylene as measured under stated conditions with some degree of accuracy. Using 26.016 as the molecular weight of the gas (O = 16), 1 litre of dry acetylene at 0° C. and 760 mm. weighs 1.16963 grammes, or 1 gramme measures 0.854973 litre. From this it follows that the theoretical specific gravity of the gas at 0°/0° C. is 0.9039 (air = 1), a figure which may be compared with Leduc's experimental value of 0.9056. Taking as the coefficient of expansion at constant pressure the figure already given, viz., 0.003738, the weights and measures of dry and moist acetylene observed under British conditions (60° F. and 30 inches of mercury) become approximately: Dry. Saturated. 1 litre . . . 1.108 grm. . . 1.102 grm. 1 gramme . . . 0.902 litre. . . 0.907 litre. 1000 cubic feet . 69.18 lb. . . . 68.83 lb. It should be remembered that unless the gas has been passed through a chemical drier, it is always saturated with aqueous vapour, the amount of water present being governed by the temperature and pressure. The 1 litre of moist acetylene which weighs 1.102 gramme at 60° F. and 30 inches of mercury, contains 0.013 gramme of water vapour; and therefore the weight of dry acetylene in the 1 litre of moist gas is 1.089 gramme. Similarly, the 68.83 pounds which constitute the weight of 1000 cubic feet of moist acetylene, as measured under British standard conditions, are composed of almost exactly 68 pounds of dry acetylene and 0.83 pound of water vapour. The data required in calculating the mass of vapour in a known volume of a saturated gas at any observed temperature and pressure, _i.e._, in reducing the figures to those which represent the dry gas at any other (standard) temperature and pressure, will be found in the text-books of physical chemistry. It is necessary to recollect that since coal-gas is measured wet, the factors given in the table quoted in Chapter XIV. from the "Notification of the Gas Referees" simply serve to convert the volume of a wet gas observed under stated conditions to the equivalent volume of the same wet gas at the standard conditions mentioned. HEAT OF COMBUSTION, &C--Based on Berthelot and Matignon's value for the heat of combustion which is given on a subsequent page, viz., 315.7 large calories per molecular weight of 26.016 grammes, the calorific power of acetylene under different conditions is shown in the following table: Dry. Dry. Saturated. 0° C. & 760 mm. 60° F & 30 ins. 60° F. & 30 ins. 1 gramme 12.14 cals. 12.14 cals. 12.0 cals. 1 litre 14.l9 " 13.45 " 13.22 " 1 cubic foot 40.19 " 380.8 " 374.4 " The figures in the last column refer to the dry acetylene in the gas, no correction having been made for the heat absorbed by the water vapour present. As will appear in Chapter X., the average of actual determinations of the calorific value of ordinary acetylene is 363 large calories or 1440 B.Th.U. per cubic foot. The temperature of ignition of acetylene has been generally stated to be about 480° C. V. Meyer and Münch in 1893 found that a mixture of acetylene and oxygen ignited between 509° and 515° C. Recent (1909) investigations by H. B. Dixon and H. F. Coward show, however, that the ignition temperature in neat oxygen is between 416° and 440° (mean 428° C.) and in air between 406° and 440°, with a mean of 429° C. The corresponding mean temperature of ignition found by the same investigators for other gases are: hydrogen, 585°; carbon monoxide, moist 664°, dry 692°; ethylene, in oxygen 510°, in air 543°; and methane, in oxygen between 550° and 700°, and in air, between 650° and 750° C. Numerous experiments have been performed to determine the temperature of the acetylene flame. According to an exhaustive research by L. Nichols, when the gas burns in air it attains a maximum temperature of 1900° C. ± 20°, which is 120° higher than the temperature he found by a similar method of observation for the coal-gas flame (fish-tail burner). Le Chatelier had previously assigned to the acetylene flame a temperature between 2100° and 2400°, while Lewes had found for the dark zone 459°, for the luminous zone 1410°, and for the tip 1517° C, Féry and Mahler have also made measurements of the temperatures afforded by acetylene and other fuels, some of their results being quoted below. Féry employed his optical method of estimating the temperature, Mahler a process devised by Mallard and Le Chatelier. Mahler's figures all relate to flames supplied with air at a temperature of 0° C. and a constant pressure of 760 mm. Hydrogen . . . . . . . . . . . 1900 1960 Carbon monoxide . . . . . . . . . -- 2100 Methane . . . . . . . . . . . -- _ 1850 Coal-gas (luminous) . . . . . . . . 1712 | " (atmospheric, with deficient supply of air) . 1812 | 1950 " (atmospheric, with full supply of air) . . 1871 _| Water-gas . . . . . . . . . . -- 2000 Oxy-coal-gas blowpipe . . . . . . . 2200 -- Oxy-hydrogen blowpipe . . . . . . . 2420 -- Acetylene . . . . . . . . . . 2548 2350 Alcohol . . . . . . . . . . . 1705 1700 Alcohol (in Denayrouze Bunsen) . . . . . 1862 -- Alcohol and petrol in equal parts . . . . 2053 -- Crude petroleum (American) . . . . . . -- 2000 Petroleum spirit " . . . . . . . -- 1920 Petroleum oil " . . . . . . . -- 1660 Catani has published the following determinations of the temperature yielded by acetylene when burnt with cold and hot air and also with oxygen: Acetylene and cold air . . . . . . 2568° C. " air at 500° C . . . . 2780° C. " air at 1000° C . . . . 3000° C. " oxygen . . . . . . 4160° C. EXPLOSIVE LIMITS.--The range of explosibility of mixtures of acetylene and air has been determined by various observers. Eitner's figures for the lower and upper explosive limits, when the mixture, at 62.6° F., is in a tube 19 mm. in diameter, and contains 1.9 per cent. of aqueous vapour, are 3.35 and 52.3 per cent. of acetylene (_cf._ Chapter X.). In this case the mixture was fired by electric spark. In wider vessels, the upper explosive limit, when the mixture was fired by a Bunsen flame, was found to be as high as 75 per cent. of acetylene. Eitner also found that when 13 of the 21 volumes of oxygen in air are displaced by carbon dioxide, a mixture of such "carbon dioxide air" with acetylene is inexplosive in all proportions. Also that when carbon dioxide is added to a mixture of acetylene and air, an explosion no longer occurs when the carbon dioxide amounts to 46 volumes or more to every 54 volumes of air, whatever may be the proportion of acetylene in the mixture. [Footnote: According to Caro, if acetylene is added to a mixture composed of 55 per cent. by volume of air and 45 per cent. of carbon dioxide, the whole is only explosive when the proportion of acetylene lies between 5.0 and 5.8 per cent. Caro has also quoted the effect of various inflammable vapours upon the explosive limits of acetylene, his results being referred to in Chapter X.] These figures are valuable in connexion with the prevention of the formation of explosive mixtures of air and acetylene when new mains or plant are being brought into operation (_cf._ Chapter VII.). Eitner has also shown, by direct investigation on mixtures of other combustible gases and air, that the range of explosibility is greatly reduced by increase in the proportion of aqueous vapour present. As the proportion of aqueous vapour in gas standing over water increases with the temperature the range of explosibility of mixtures of a combustible gas and air is naturally and automatically reduced when the temperature rises, provided the mixture is in contact with water. Thus at 17.0° C., mixtures of hydrogen, air, and aqueous vapour containing from 9.3 to 65.0 per cent, of hydrogen are explosive, whereas at 78.1° C., provided the mixture is saturated with aqueous vapour, explosion occurs only when the percentage of hydrogen in the mixture is between 11.2 and 21.9. The range of explosibility of mixtures of acetylene and air is similarly reduced by the addition of aqueous vapour (though the exact figures have not been experimentally ascertained); and hence it follows that when the temperature in an acetylene generator in which water is in excess, or in a gasholder, rises, the risk of explosion, if air is mixed with the gas, is automatically reduced with the rise in temperature by reason of the higher proportion of aqueous vapour which the gas will retain at the higher temperature. This fact is alluded to in Chapter II. Acetone vapour also acts similarly in lowering the upper explosive limit of acetylene (_cf._ Chapter XI.). It may perhaps be well to indicate briefly the practical significance of the range of explosibility of a mixture of air and a combustible gas, such as acetylene. The lower explosive limit is the lowest percentage of combustible gas in the mixture of it and air at which explosion will occur in the mixture if a light or spark is applied to it. If the combustible gas is present in the mixture with air in less than that percentage explosion is impossible. The upper explosive limit is the highest percentage of combustible gas in the mixture of it and air at which explosion will occur in the mixture if a light or spark is applied to it. If the combustible gas is present in the mixture with air in more than that percentage explosion is impossible. Mixtures, however, in which the percentage of combustible gas lies between these two limits will explode when a light or spark is applied to them; and the comprehensive term "range of explosibility" is used to cover all lying between the two explosive limits. If, then, a naked light is applied to a vessel containing a mixture of a combustible gas and air, in which mixture the proportion of combustible gas is below the lower limit of explosibility, the gas will not take fire, but the light will continue to burn, deriving its necessary oxygen from the excess of air present. On the other hand, if a light is applied to a vessel containing a mixture of a combustible gas and air, in which mixture the proportion of combustible gas is above the upper limit of explosibility, the light will be extinguished, and within the vessel the gaseous mixture will not burn; but it may burn at the open mouth of the vessel as it comes in contact with the surrounding air, until by diffusion, &c., sufficient air has entered the vessel to form, with the remaining gas, a mixture lying within the explosive limits, when an explosion will occur. Again, if a gaseous mixture containing less of its combustible constituent than is necessary to attain the lower explosive limit escapes from an open-ended pipe and a light is applied to it, the mixture will not burn as a useful compact flame (if, indeed, it fires at all); if the mixture contains more of its combustible constituent than is required to attain the upper explosive limit, that mixture will burn quietly at the mouth of the pipe and will be free from any tendency to fire back into the pipe--assuming, of course, that the gaseous mixture within the pipe is constantly travelling towards the open end. If, however, a gaseous mixture containing a proportion of its combustible constituent which lies between the lower and the upper explosive limit of that constituent escapes from an open- ended pipe and a light is applied, the mixture will fire and the flame will pass back into the pipe, there to produce an explosion, unless the orifice of the said pipe is so small as to prevent the explosive wave passing (as is the case with a proper acetylene burner), or unless the pipe itself is so narrow as appreciably to alter the range of explosibility by lowering the upper explosive limit from its normal value. By far the most potent factor in altering the range of explosibility of any gas when mixed with air is the diameter of the vessel containing or delivering such mixture. Le Chatelier has investigated this point in the case of acetylene, and his values are reproduced overleaf; they are comparable among themselves, although it will be observed that his absolute results differ somewhat from those obtained by Eitner which are quoted later: _Explosive Limits of Acetylene mixed with Air._--(Le Chatelier.) ___________________________________________________________ | | | | | | Explosive Limits. | | | Diameter of Tube |_______________________| Range of | | in Millimetres. | | | Explosibility. | | | Lower. | Upper. | | |__________________|___________|___________|________________| | | | | | | | Per Cent. | Per Cent. | Per Cent. | | 40 | 2.9 | 64 | 61.1 | | 30 | 3.1 | 62 | 58.9 | | 20 | 3.5 | 55 | 51.5 | | 6 | 4.0 | 40 | 36.0 | | 4 | 4.5 | 25 | 20.5 | | 2 | 5.0 | 15 | 10.0 | | 0.8 | 7.7 | 10 | 2.3 | | 0.5 | ... | ... | ... | |__________________|___________|___________|________________| Thus it appears that past an orifice or constriction 0.5 mm. in diameter no explosion of acetylene can proceed, whatever may be the proportions between the gas and the air in the mixture present. With every gas the explosive limits and the range of explosibility are also influenced by various circumstances, such as the manner of ignition, the pressure, and other minor conditions; but the following figures for mixtures of air and different combustible gases were obtained by Eitner under similar conditions, and are therefore strictly comparable one with another. The conditions were that the mixture was contained in a tube 19 mm. (3/4-inch) wide, was at about 60° to 65° F., was saturated with aqueous vapour, and was fired by electric spark. _Table giving the Percentage by volume of Combustible Gas in a Mixture of that Gas and Air corresponding with the Explosive Limits of such a Mixture._--(Eitner.) ____________________________________________________________________ | | | | | | Description of | Lower | Upper | Difference between the | | Combustible Gas. | Explosive | Explosive | Lower and Upper Limits, | | | Limit. | Limit. | showing the range | | | | | covered by the | | | | | Explosive Mixtures. | |__________________|___________|___________|_________________________| | | | | | | | Per Cent. | Per Cent. | Per Cent. | | Carbon monoxide | 16.50 | 74.95 | 58.45 | | Hydrogen | 9.45 | 66.40 | 57.95 | | Water-gas | | | | | (uncarburetted) | 12.40 | 66.75 | 54.35 | | ACETYLENE | 3.35 | 52.30 | 48.95 | | Coal-gas | 7.90 | 19.10 | 11.20 | | Ethylene | 4.10 | 14.60 | 10.50 | | Methane | 6.10 | 12.80 | 6.70 | | Benzene (vapour) | 2.65 | 6.50 | 3.85 | | Pentane " | 2.40 | 4.90 | 2.50 | | Benzoline " | 2.40 | 4.90 | 2.50 | |__________________|___________|___________|_________________________| These figures are of great practical significance. They indicate that a mixture of acetylene and air becomes explosive (_i.e._, will explode if a light is applied to it) when only 3.35 per cent. of the mixture is acetylene, while a similar mixture of coal-gas and air is not explosive until the coal-gas reaches 7.9 per cent. of the mixture. And again, air may be added to coal-gas, and it does not become explosive until the coal-gas is reduced to 19.1 per cent. of the mixture, while, on the contrary, if air is added to acetylene, the mixture becomes explosive as soon as the acetylene has fallen to 52.3 per cent. Hence the immense importance of taking precautions to avoid, on the one hand, the escape of acetylene into the air of a room, and, on the other hand, the admixture of air with the acetylene in any vessel containing it or any pipe through which it passes. These precautions are far more essential with acetylene than with coal-gas. The table shows further how great is the danger of explosion if benzene, benzoline, or other similar highly volatile hydrocarbons [Footnote: The nomenclature of the different volatile spirits is apt to be very confusing. "Benzene" is the proper name for the most volatile hydrocarbon derived from coal-tar, whose formula is C_6H_6. Commercially, benzene is often known as "benzol" or "benzole"; but it would be generally advantageous if those latter words were only used to mean imperfectly rectified benzene, _i.e._, mixtures of benzene with toluene, &c., such as are more explicitly understood by the terms "90.s benzol" and "50.s benzol." "Gasoline," "carburine," "petroleum ether," "benzine," "benzoline," "petrol," and "petroleum spirit" all refer to more or less volatile (the most volatile being mentioned first) and more or less thoroughly rectified products obtained from petroleum. They are mixtures of different hydrocarbons, the greater part of them having the general chemical formula C_nH_2n+2 where n = 5 or more. None of them is a definite chemical compound as is benzene; when n = 5 only the product is pentane. These hydrocarbons are known to chemists as "paraffins," "naphthenes" being occasionally met with; while a certain proportion of unsaturated hydrocarbons is also present in most petroleum spirits. The hydrocarbons of coal-tar are "aromatic hydrocarbons," their generic formula being C_nH_2^n-6, where n is never less than 6.] are allowed to vaporise in a room in which a light may be introduced. Less of the vapour of these hydrocarbons than of acetylene in the air of a room brings the mixture to the lower explosive limit, and therewith subjects it to the risk of explosion. This tact militates strongly against the use of such hydrocarbons within a house, or against the use of air-gas, which, as explained in Chapter I., is air more or less saturated with the vapour of volatile hydrocarbons. Conversely, a combustible gas, such as acetylene, may be safely "carburetted" by these hydrocarbons in a properly constructed apparatus set up outside the dwelling-house, as explained in Chapter X., because there would be no air (as in air-gas) in the pipes, &c., and a relatively large escape of carburetted acetylene would be required to produce an explosive atmosphere in a room. Moreover, the odour of the acetylene itself would render the detection of a leak far easier with carburetted acetylene than with air-gas. N. Teclu has investigated the explosive limits of mixtures of air with certain combustible gases somewhat in the same manner as Eitner, viz.: by firing the mixture in an eudiometer tube by means of an electric spark. He worked, however, with the mixture dry instead of saturated with aqueous vapour, which doubtless helps to account for the difference between his and Eitner's results. _Table giving the Percentages by volume of Combustible Gas in a Dehydrated Mixture of that Gas and Air between which the Explosive Limits of such a Mixture lie._--(Teclu). ____________________________________________________________________ | | | | | | Lower Explosive Limit. | Upper Explosive Limit. | | Description of |________________________|________________________| | Combustible Gas. | | | | | Per Cent. of Gas. | Per Cent. of Gas. | |__________________|________________________|________________________| | | | | | ACETYLENE | 1.53-1.77 | 57.95-58.65 | | Hydrogen | 9.73-9.96 | 62.75-63.58 | | Coal-gas | 4.36-4.82 | 23.35-23.63 | | Methane | 3.20-3.67 | 7.46- 7.88 | |__________________|________________________|________________________| Experiments have been made at Lechbruch in Bavaria to ascertain directly the smallest proportion of acetylene which renders the air of a room explosive. Ignition was effected by the flame resulting when a pad of cotton-wool impregnated with benzoline or potassium chlorate was fired by an electrically heated wire. The room in which most of the tests were made was 8 ft. 10 in. long, 6 ft. 7 in. wide, and 6 ft. 8 in. high, and had two windows. When acetylene was generated in this room in normal conditions of natural ventilation through the walls, the volume generated could amount to 3 per cent. of the air-space of the room without explosion ensuing on ignition of the wool, provided time elapsed for equable diffusion, which, moreover, was rapidly attained. Further, it was found that when the whole of the acetylene which 2 kilogrammes or 4.4 lb. of carbide (the maximum permissible charge in many countries for a portable lamp for indoor use) will yield was liberated in a room, a destructive explosion could not ensue on ignition provided the air-space exceeded 40 cubic metres or 1410 cubic feet, or, if the evolved gas were uniformly diffused, 24 cubic metres or 850 cubic feet. When the walls of the room were rendered impervious to air and gas, and acetylene was liberated, and allowed time for diffusion, in the air of the room, an explosion was observed with a proportion of only 2-1/2 per cent. of acetylene in the air. _Solubility of Acetylene in Various Liquids._ _____________________________________________________________________ | | | | | | | | Volumes of | | | | Tem- | Acetylene | | | Solvent. |perature.|dissolved by| Authority. | | | | 100 Vols. | | | | | of Solvent.| | |___________________________|_________|____________|__________________| | | | | | | | Degs. C | | | | Acetone . . . . | 15 | 2500 | Claude and Hess | | " . . . . | 50 | 1250 | " | | Acetic acid; alcohol . | 18 | 600 | Berthelot | | Benzoline; chloroform . | 18 | 400 | " | | Paraffin oil . . . | 0 | 103.3 | E. Muller | | " . . . | 18 | 150 | Berthelot | | Olive oil . . . . | -- | 48 | Fuchs and Schiff | | Carbon bisulphide . . | 18 | 100 | Berthelot | | " tetrachloride . | 0 | 25 | Nieuwland | | Water (at 4 65 atmospheres| | | | | pressure) . . | 0 | 160 | Villard | | " (at 755 mm. pressure)| 12 | 118 | Berthelot | | " (760 mm. pressure) . | 12 | 106.6 | E. Müller | | " " . | 15 | 110 | Lewes | | " " . | 18 | 100 | Berthelot | | " " . | -- | 100 | E. Davy (in 1836)| | " " . | 19.5 | 97.5 | E. Müller | | Milk of lime: about 10 | | | | | grammes of calcium hy- | 5 | 112 | Hammerschmidt | | droxide per 100 c.c. . | | | and Sandmann | | " " " | 10 | 95 | " | | " " " | 20 | 75 | " | | " " " | 50 | 38 | " | | " " " | 70 | 20 | " | | " " " | 90 | 6 | " | | Solution of common salt,5%| 19 | 67.9 | " | | (sodium chloride) " | 25 | 47.7 | " | | " 20%| 19 | 29.6 | " | | " " | 25 | 12.6 | " | | "(nearly saturated, | | | | | 26%) . . | 15 | 20.6 | " | | "(saturated, sp. gr.| | | | | 1-21) . . | 0 | 22.0 | E. Müller | | " " " | 12 | 21.0 | " | | " " " | 18 | 20.4 | " | | Solution of calcium | | | Hammerschmidt | | chloride (saturated) . | 15 | 6.0 | and Sandmann | | Bergé and Reychler's re- | | | | | agent . . . . | -- | 95 | Nieuwland | |___________________________|_________|____________|__________________| SOLUBILITY.--Acetylene is readily soluble in many liquids. It is desirable, on the one hand, as indicated in Chapter III., that the liquid in the seals of gasholders, &c., should be one in which acetylene is soluble to the smallest degree practically attainable; while, on the other hand, liquids in which acetylene is soluble in a very high degree are valuable agents for its storage in the liquid state. Hence it is important to know the extent of the solubility of acetylene in a number of liquids. The tabular statement (p. 179) gives the most trustworthy information in regard to the solubilities under the normal atmospheric pressure of 760 mm. or thereabouts. The strength of milk of lime quoted in the above table was obtained by carefully allowing 50 grammes of carbide to interact with 550 c.c. of water at 5° C. A higher degree of concentration of the milk of lime was found by Hammerschmidt and Sandmann to cause a slight decrease in the amount of acetylene held in solution by it. Hammerschmidt and Sandmann's figures, however, do not agree well with others obtained by Caro, who has also determined the solubility of acetylene in lime-water, using first, a clear saturated lime-water prepared at 20° C. and secondly, a milk of lime obtained by slaking 10 grammes of quicklime in 100 c.c. of water. As before, the figures relate to the volumes of acetylene dissolved at atmospheric pressure by 100 volumes of the stated liquid. _________________________________________________ | | | | | Temperature. | Lime-water. | Milk of Lime. | |_______________|_______________|_________________| | | | | | Degs C. | | | | 0 | 146.2 | 152.6 | | 5 | 138.5 | -- | | 15 | 122.8 | 134.8 | | 50 | 43.9 | 62.6 | | 90 | 6.2 | 9.2 | |_______________|_______________|_________________| Figures showing the solubility of acetylene in plain water at different temperatures have been published in Landolt-Börnstein's Physico- Chemical Tables. These are reproduced below. The "Coefficient of Absorption" is the volume of the gas, measured at 0° C. and a barometric height of 760 mm. taken up by one volume of water, at the stated temperature, when the gas pressure on the surface, apart from the vapour pressure of the water itself, is 760 mm. The "Solubility" is the weight of acetylene in grammes taken up by 100 grammes of water at the stated temperature, when the total pressure on the surface, including that of the vapour pressure of the water, is 760 mm. _____________________________________________ | | | | | Temperature. | Coefficient of | Solubility. | | | Absorption. | | |______________|________________|_____________| | | | | | Degs. C. | | | | 0 | 1.73 | 0.20 | | 1 | 1.68 | 0.19 | | 2 | 1.63 | 0.19 | | 3 | 1.58 | 0.18 | | 4 | 1.53 | 0.18 | | 5 | 1.49 | 0.17 | | 6 | 1.45 | 0.17 | | 7 | 1.41 | 0.16 | | 8 | 1.37 | 0.16 | | 9 | 1.34 | 0.15 | | 10 | 1.31 | 0.15 | | 11 | 1.27 | 0.15 | | 12 | 1.24 | 0.14 | | 13 | 1.21 | 0.14 | | 14 | 1.18 | 0.14 | | 15 | 1.15 | 0.13 | | 16 | 1.13 | 0.13 | | 17 | 1.10 | 0.13 | | 18 | 1.08 | 0.12 | | 19 | 1.05 | 0.12 | | 20 | 1.03 | 0.12 | | 21 | 1.01 | 0.12 | | 22 | 0.99 | 0.11 | | 23 | 0.97 | 0.11 | | 24 | 0.95 | 0.11 | | 25 | 0.93 | 0.11 | | 26 | 0.91 | 0.10 | | 27 | 0.89 | 0.10 | | 28 | 0.87 | 0.10 | | 29 | 0.85 | 0.10 | | 30 | 0.84 | 0.09 | |______________|________________|_____________| Advantage is taken, as explained in Chapter XI., of the high degree of solubility of acetylene in acetone, to employ a solution of the gas in that liquid when acetylene is wanted in a portable condition. The solubility increases very rapidly with the pressure, so that under a pressure of twelve atmospheres acetone dissolves about 300 times its original volume of the gas, while the solubility also increases greatly with a reduction in the temperature, until at -80° C. acetone takes up 2000 times its volume of acetylene under the ordinary atmospheric pressure. Further details of the valuable qualities of acetone as a solvent of acetylene are given in Chapter XI., but it may here be remarked that the successful utilisation of the solvent power of acetone depends to a very large extent on the absolute freedom from moisture of both the acetylene and the acetone, so that acetone of 99 per cent. strength is now used as the solvent. Turning to the other end of the scale of solubility, the most valuable liquids for serving as seals of gasholders, &c., are readily discernible. Far superior to all others is a saturated solution of calcium chloride, and this should be selected as the confining liquid whenever it is important to avoid dissolution of acetylene in the liquid as far as may be. Brine comes next in order of merit for this purpose, but it is objectionable on account of its corrosive action on metals. Olive oil should, according to Fuchs and Schiff, be of service where a saline liquid is undesirable; mineral oil seems useless. Were they concordant, the figures for milk of lime would be particularly useful, because this material is naturally the confining liquid in the generating chambers of carbide-to-water apparatus, and because the temperature of the liquid rises through the heat evolved during the generation of the gas (_vide_ Chapters II. and III.). It will be seen that these figures would afford a means of calculating the maximum possible loss of gas by dissolution when a known volume of sludge is run off from a carbide-to- water generator at about any possible temperature. According to Garelli and Falciola, the depression in the freezing-point of water caused by the saturation of that liquid with acetylene is 0.08° C., the corresponding figure for benzene in place of water being 1.40° C. These figures indicate that 100 parts by weight of water should dissolve 0.1118 part by weight of acetylene at 0° C., and that 100 parts of benzene should dissolve about 0.687 part of acetylene at 5° C. In other words, 100 volumes of water at the freezing-point should dissolve 95 volumes of acetylene, and 100 volumes of benzene dissolve some 653 volumes of the gas. The figure calculated for water in this way is lower than that which might be expected from the direct determinations at other temperatures already referred to; that for benzene may be compared with Berthelot's value of 400 volumes at 18° C. Other measurements of the solubility of acetylene in water at 0° C. have given the figure 0.1162 per cent. by weight. TOXICITY.--Many experiments have been made to determine to what extent acetylene exercises a toxic action on animals breathing air containing a large proportion of it; but they have given somewhat inconclusive results, owing probably to varying proportions of impurities in the samples of acetylene used. The sulphuretted hydrogen and phosphine which are found in acetylene as ordinarily prepared are such powerful toxic agents that they would always, in cases of "acetylene" poisoning, be largely instrumental in bringing about the effects observed. Acetylene _per se_ would appear to have but a small toxic action; for the principal toxic ingredient in coal-gas is carbon monoxide, which does not occur in sensible quantity in acetylene as obtained from calcium carbide. The colour of blood is changed by inhalation of acetylene to a bright cherry-red, just as in cases of poisoning by carbon monoxide; but this is due to a more dissolution of the gas in the haemoglobin of the blood, so that there is much more hope of recovery for a subject of acetylene poisoning than for one of coal-gas poisoning. Practically the risk of poisoning by acetylene, after it has been purified by one of the ordinary means, is _nil_. The toxic action of the impurities of crude acetylene is discussed in Chapter V. Acetylene is an "endothermic" compound, as has been mentioned in Chapter II., where the meaning of the expression endothermic is explained. It has there been indicated that by reason of its endothermic nature it is unsafe to have acetylene at either a temperature of 780° C. and upwards, or at a pressure of two atmospheres absolute, or higher. If that temperature or that pressure is exceeded, dissociation (_i.e._, decomposition into its elements), if initiated at any spot, will extend through the whole mass of acetylene. In this sense, acetylene at or above 780° C., or at two or more atmospheres pressure, is explosive in the absence of air or oxygen, and it is thereby distinguished from the majority of other combustible gases, such as the components of coal-gas. But if, by dilution with another gas, the partial pressure of the acetylene is reduced, then the mixture may be subjected to a higher pressure than that of two atmospheres without acquiring explosiveness, as is fully shown in Chapter XI. Thus it becomes possible safely to compress mixtures of acetylene and oil-gas or coal-gas, whereas unadmixed acetylene cannot be safely kept under a pressure of two atmospheres absolute or more. In a series of experiments carried out by Dupré on behalf of the British Home Office, and described in the Report on Explosives for 1897, samples of moist acetylene, free from air, but apparently not purified by any chemical process, were exposed to the influence of a bright red-hot wire. When the gas was held in the containing vessel at the atmospheric pressure then obtaining, viz., 30.34 inches (771 mm.) of mercury, no explosion occurred. When the pressure was raised to 45.34 inches (1150 mm.), no explosion occurred; but when the pressure was further raised to 59.34 inches (1505 mm., or very nearly two atmospheres absolute) the acetylene exploded, or dissociated into its elements. Acetylene readily polymerises when heated, as has been stated in Chapter II., where the meaning of the term "polymerisation" has been explained. The effects of the products of the polymerisation of acetylene on the flame produced when the gas is burnt at the ordinary acetylene burners have been stated in Chapter VIII., where the reasons therefor have been indicated. The chief primary product of the polymerisation of acetylene by heat appears to be benzene. But there are also produced, in some cases by secondary changes, ethylene, methane, naphthalene, styrolene, anthracene, and homologues of several of these hydrocarbons, while carbon and hydrogen are separated. The production of these bodies by the action of heat on acetylene is attended by a reduction of the illuminative value of the gas, while owing to the change in the proportion of air required for combustion (_see_ Chapter VIII.), the burners devised for the consumption of acetylene fail to consume properly the mixture of gases formed by polymerisation from the acetylene. It is difficult to compare the illuminative value of the several bodies, as they cannot all be consumed economically without admixture, but the following table indicates approximately the _maximum_ illuminative value obtainable from them either by combustion alone or in admixture with some non- illuminating or feebly-illuminating gas: ________________________________________________ | | | | | | | Candles per | | | | Cubic Foot | |______________|___________________|_____________| | | | | | | | (say) | | Acetylene | C_2H_2 | 50 | | Hydrogen | H_2 | 0 | | Methane | CH_4 | 1 | | Ethane | C_2H_6 | 7 | | Propane | C_3H_8 | 11 | | Pentane | C_5H_12 (vapour) | 35 | | Hexane | C_6H_14 " | 45 | | Ethylene | C_2H_4 | 20 | | Propylene | C_3H_6 | 25 | | Benzene | C_6H_6 (vapour) | 200 | | Toluene | C_7H_8 " | 250 | | Naphthalene | C_10H_8 " | 400 | |______________|___________________|_____________| It appears from this table that, with the exception of the three hydrocarbons last named, no substance likely to be formed by the action of heat on acetylene has nearly so high an illuminative value--volume for volume--as acetylene itself. The richly illuminating vapours of benzene and naphthalene (and homologues) cannot practically add to the illuminative value of acetylene, because of the difficulty of consuming them without smoke, unless they are diluted with a large proportion of feebly- or non-illuminating gas, such as methane or hydrogen. The practical effect of carburetting acetylene with hydrocarbon vapours will be shown in Chapter X. to be disastrous so far as the illuminating efficiency of the gas is concerned. Hence it appears that no conceivable products of the polymerisation of acetylene by heat can result in its illuminative value being improved--even presupposing that the burners could consume the polymers properly--while practically a considerable deterioration of its value must ensue. The heat of combustion of acetylene was found by J. Thomson to be 310.57 large calories per gramme-molecule, and by Berthelot to be 321.00 calories. The latest determination, however, made by Berthelot and Matignon shows it to be 315.7 calories at constant pressure. Taking the heat of formation of carbon dioxide from diamond carbon at constant pressure as 94.3 calories (Berthelot and Matignon), which is equal to 97.3 calories from amorphous carbon, and the heat of formation of liquid water as 69 calories; this value for the heat of combustion of acetylene makes its heat of formation to be 94.3 x 2 + 69 - 315.7 = -58.1 large calories per gramme-molecule (26 grammes) from diamond carbon, or -52.1 from amorphous carbon. It will be noticed that the heat of combustion of acetylene is greater than the combined heats of combustion of its constituents; which proves that heat has been absorbed in the union of the hydrogen and carbon in the molecule, or that acetylene is endothermic, as elsewhere explained. These calculations, and others given in Chapter IX., will perhaps be rendered more intelligible by the following table of thermochemical phenomena: _______________________________________________________________ | | | | | | Reaction. | Diamond | Amorphous | | | | Carbon. | Carbon. | | |________________________________|_________|___________|________| | | | | | | (1) C (solid) + O . . . | 26.1 | 29.1 | ... | | (2) C (solid) + O_2 . . . | 94.3 | 97.3 | ... | | (3) CO + O (2 - 1) . . . | ... | ... | 68.2 | | (4) Conversion of solid carbon | | | | | into gas (3 - 1) . . . | 42.1 | 39.1 | ... | | (5) C (gas) + O (1 + 4) . . | ... | ... | 68.2 | | (6) Conversion of amorphous | | | | | carbon to diamond . . | ... | ... | 3.0 | | (7) C_2 + H_2 . . . . | -58.1 | -52.1 | ... | | (8) C_2H_2 + 2-1/2O_2 . . | ... | ... | 315.7 | |________________________________|_________|___________|________| W. G. Mixter has determined the heat of combustion of acetylene to be 312.9 calories at constant volume, and 313.8 at constant pressure. Using Berthelot and Matignon's data given above for amorphous carbon, this represents the heat of formation to be -50.2 (Mixter himself calculates it as -51.4) calories. By causing compressed acetylene to dissociate under the influence of an electric spark, Mixter measured its heat of formation as -53.3 calories. His corresponding heats of combustion of ethylene are 344.6 calories (constant volume) and 345.8 (constant pressure); for its heat of formation he deduces a value -7.8, and experimentally found one of about -10.6 (constant pressure). THE ACETYLENE FLAME.--It has been stated in Chapter I. that acetylene burnt in self-luminous burners gives a whiter light than that afforded by any other artificial illuminant, because the proportion of the various spectrum colours in the light most nearly resembles the corresponding proportion found in the direct rays of the sun. Calling the amount of monochromatic light belonging to each of the five main spectrum colours present in the sun's rays unity in succession, and comparing the amount with that present in the light obtained from electricity, coal-gas, and acetylene, Münsterberg has given the following table for the composition of the several lights mentioned: ______________________________________________________________________ | | | | | | | | Electricity | Coal-Gas | Acetylene | | | |________________|__________________|_______________|_______| | Colour | | | | | | | | | in | | | | | | With | | | Spectrum.| Arc. | Incan- | Lumin- | Incan- | Alone.| 3 per | Sun- | | | | descent.| ous. | descent.| | Cent. | light.| | | | | | | | Air. | | |__________|______|_________|________|_________|_______|_______|_______| | | | | | | | | | | Red | 2.09 | 1.48 | 4.07 | 0.37 | 1.83 | 1.03 | 1 | | Yellow | 1.00 | 1.00 | 1.00 | 0.90 | 1.02 | 1.02 | 1 | | Green | 0.99 | 0.62 | 0.47 | 4.30 | 0.76 | 0.71 | 1 | | Blue | 0.87 | 0.91 | 1.27 | 0.74 | 1.94 | 1.46 | 1 | | Violet | 1.08 | 0.17 | 0.15 | 0.83 | 1.07 | 1.07 | 1 | | Ultra- | | | | | | | | | Violet | 1.21 | ... | ... | ... | ... | ... | 1 | |__________|______|_________|________|_________|_______|_______|_______| These figures lack something in explicitness; but they indicate the greater uniformity of the acetylene light in its proportion of rays of different wave-lengths. It does not possess the high proportion of green of the Welsbach flame, or the high proportion of red of the luminous gas- flame. It is interesting to note the large amount of blue and violet light in the acetylene flame, for these are the colours which are chiefly concerned in photography; and it is to their prominence that acetylene has been found to be so very actinic. It is also interesting to note that an addition of air to acetylene tends to make the light even more like that of the sun by reducing the proportion of red and blue rays to nearer the normal figure. H. Erdmann has made somewhat similar calculation, comparing the light of acetylene with that of the Hefner (amyl acetate) lamp, and with coal-gas consumed in an Argand and an incandescent burner. Consecutively taking the radiation of the acetylene flame as unity for each of the spectrum colours, his results are: __________________________________________________________________ | | | | | | | | | Coal-Gas | | Colour in | Wave-Lengths, | |_______________________| | Spectrum | uu | Hefner Light | | | | | | | Argand | Incandescent | |___________|_______________|______________|________|______________| | | | | | | | Red | 650 | 1.45 | 1.34 | 1.03 | | Orange | 610 | 1.22 | 1.13 | 1.00 | | Yellow | 590 | 1.00 | 1.00 | 1.00 | | Green | 550 | 0.87 | 0.93 | 0.86 | | Blue | 490 | 0.72 | 1.27 | 0.92 | | Violet | 470 | 0.77 | 1.35 | 1.73 | |___________|_______________|______________|________|______________| B. Heise has investigated the light of different flames, including acetylene, by a heterochromatic photometric method; but his results varied greatly according to the pressure at which the acetylene was supplied to the burner and the type of burner used. Petroleum affords light closely resembling in colour the Argand coal-gas flame; and electric glow-lamps, unless overrun and thereby quickly worn out, give very similar light, though with a somewhat greater preponderance of radiation in the red and yellow. ____________________________________________________________________ | | | | | | Percent of Total | | | Light. | Energy manifested | Observer. | | | as Light. | | |____________________________|___________________|___________________| | | | | | Candle, spermaceti . . | 2.1 | Thomsen | | " paraffin . . . | 1.53 | Rogers | | Moderator lamp . . . | 2.6 | Thomsen | | Coal-gas . . . . . | 1.97 | Thomsen | | " . . . . . | 2.40 | Langley | | " batswing . . . | 1.28 | Rogers | | " Argand . . . | 1.61 | Rogers | | " incandesce . . | 2 to 7 | Stebbins | | Electric glow-lamp . . | about 6 | Merritt | | " " . . | 5.5 | Abney and Festing | | Lime light (new) . . . | 14 | Orehore | | " (old) . . . | 8.4 | Orehore | | Electric arc . . . . | 10.4 | Tyndall; Nakano | | " . . . . | 8 to 13 | Marks | | Magnesium light . . . | 12.5 | Rogers | | Acetylene . . . . | 10.5 | Stewart and Hoxie | | " (No. 0 slit burner | 11.35 | Neuberg | | " (No. 00000 . . | | | | Bray fishtail) | 13.8 | Neuberg | | " (No. 3 duplex) . | 14.7 | Neuberg | | Geissler tube . . . | 32.0 | Staub | |____________________________|___________________|___________________| Violle and Féry, also Erdmann, have proposed the use of acetylene as a standard of light. As a standard burner Féry employed a piece of thermometer tube, cut off smoothly at the end and having a diameter of 0.5 millimetre, a variation in the diameter up to 10 per cent. being of no consequence. When the height of the flame ranged from 10 to 25 millimetres the burner passed from 2.02 to 4.28 litres per hour, and the illuminating power of the light remained sensibly proportional to the height of the jet, with maximum variations from the calculated value of ±0.008. It is clear that for such a purpose as this the acetylene must be prepared from very pure carbide and at the lowest possible temperature in the generator. Further investigations in this direction should be welcome, because it is now fairly easy to obtain a carbide of standard quality and to purify the gas until it is essentially pure acetylene from a chemical point of view. L. W. Hartmann has studied the flame of a mixture of acetylene with hydrogen. He finds that the flame of the mixture is richer in light of short wave-lengths than that of pure acetylene, but that the colour of the light does not appear to vary with the proportion of hydrogen present. Numerous investigators have studied the optical or radiant efficiency of artificial lights, _i.e._, the proportion of the total heat plus light energy emitted by the flame which is produced in the form of visible light. Some results are shown in the table on the previous page. Figures showing the ratio of the visible light emitted by various illuminants to the amount of energy expended in producing the light and also the energy equivalent of each spherical Hefner unit evolved have been published by H. Lux, whose results follow: _______________________________________________________________________ | | | | | | | | Ratio of | Ratio of | Mean | Energy | | | Light | Light | Spherical | Equiva- | | Light. | emitted to | emitted to | Illuminat- | lent to 1 | | | Total | Energy | ing Power. | Spherical | | | Radiation. | Impressed. | Hefners. | Hefner in | | | | | | Watts. | |____________________|____________|____________|____________|___________| | | | | | | | | Per Cent. | Per Cent. | | | | Hefner lamp | 0.89 | 0.103 | 0.825 | 0.108 | | Paraffin lamp, 14" | 1.23 | 0.25 | 12.0 | 0.105 | | ACETYLENE, 7.2 | | | | | | litre burner | 6.36 | 0.65 | 6.04 | 0.103 | | Coal-gas incandes- | | | | | | cent, upturned | 2.26-2.92 | 0.46 | 89.6 | 0.037 | | " incandes- | | | | | | cent, inverted | 2.03-2.97 | 0.51 | 82.3 | 0.035 | | Carbon filament | | | | | | glow-lamp | 3.2-2.7 | 2.07 | 24.5 | 0.085 | | Nernst lamp | 5.7 | 4.21-3.85 | 91.9 | 0.073 | | Tantalum lamp | 8.5 | 4.87 | 26.7 | 0.080 | | Osram lamp | 9.1 | 5.36 | 27.4 | 0.075 | | Direct-current arc | 8.1 | 5.60 | 524 | 0.047 | | " " enclosed | 2.0 | 1.16 | 295 | 0.021 | | Flame arc, yellow | 15.7 | 13.20 | 1145 | 0.041 | | " " white | 7.6 | 6.66 | 760 | 0.031 | | Alternating- | | | | | | current arc | 3.7 | 1.90 | 89 | 0.038 | | Uviol mercury | | | | | | vapour lamp | 5.8 | 2.24 | 344 | 0.015 | | Quartz lamp | 17.6 | 6.00 | 2960 | 0.014 | |____________________|____________|____________|____________|___________| CHEMICAL PROPERTIES.--It is unnecessary for the purpose of this work to give an exhaustive account of the general chemical reactions of acetylene with other bodies, but a few of the more important must be referred to. Since the gases are liable to unite spontaneously when brought into contact, the reactions between, acetylene and chlorine require attention, first, because of the accidents that have occurred when using bleaching- powder (_see_ Chapter V.) as a purifying material for the crude gas; secondly, because it has been proposed to manufacture one of the products of the combination, viz., acetylene tetrachloride, on a large scale, and to employ it as a detergent in place of carbon tetrachloride or carbon disulphide. Acetylene forms two addition products with chlorine, C_2H_2Cl_2, and C_2H_2Cl_4. These are known as acetylene dichloride and tetrachloride respectively, or more systematically as dichlorethylene and tetrachlorethane. One or both of the chlorides is apt to be produced when acetylene comes into contact with free chlorine, and the reaction sometimes proceeds with explosive violence. The earliest writers, such as E. Davy, Wöhler, and Berthelot, stated that an addition of chlorine to acetylene was invariably followed by an explosion, unless the mixture was protected from light; whilst later investigators thought the two gases could be safely mixed if they were both pure, or if air was absent. Owing to the conflicting nature of the statements made, Nieuwland determined in 1905 to study the problem afresh; and the annexed account is chiefly based on his experiments, which, however, still fail satisfactorily to elucidate all the phenomena observed. According to Nieuwland's results, the behaviour of mixtures of acetylene and chlorine appears capricious, for sometimes the gases unite quietly, although sometimes they explode. Acetylene and chlorine react quite quietly in the dark and at low temperatures; and neither a moderate increase in temperature, nor the admission of diffused daylight, nor the introduction of small volumes of air, is necessarily followed by an explosion. Doubtless the presence of either light, air, or warmth increases the probability of an explosive reaction, while it becomes more probable still in their joint presence; but in given conditions the reaction may suddenly change from a gentle formation of addition products to a violent formation of substitution products without any warning or manifest cause. When the gases merely unite quietly, tetrachlorethane, or acetylene tetrachloride, is produced thus: C_2H_2 + 2Cl_2 = C_2H_2Cl_4; but when the reaction is violent some hexachlorethane is formed, presumably thus: 2C_2H_2 + 5Cl_2 = 4HCl + C_2 + C_2Cl_6. The heat evolved by the decomposition of the acetylene by the formation of the hydrochloric acid in the last equation is then propagated amongst the rest of the gaseous mixture, accelerating the action, and causing the acetylene to react with the chlorine to form more hydrochloric acid and free carbon thus; C_2H_2 + Cl_2 = 2HCl + C_2. It is evident that these results do not altogether explain the mechanism of the reactions involved. Possibly the formation of substitution products and the consequent occurrence of an explosion is brought about by some foreign substance which acts as a catalytic agent. Such substance may conceivably be one of the impurities in crude acetylene, or the solid matter of a bleaching-powder purifying material. The experiments at least indicate the direction in which safety may be sought when bleaching- powder is employed to purify the crude gas, viz., dilution of the powder with an inert material, absence of air from the gas, and avoidance of bright sunlight in the place where a spent purifier is being emptied. Unfortunately Nieuwland did not investigate the action on acetylene of hypochlorites, which are presumably the active ingredients in bleaching- powder. As will appear in due course, processes have been devised and patented to eliminate all danger from the reaction between acetylene and chlorine for the purpose of making tetrachlorethane in quantity. Acetylene combines with hydrogen in the presence of platinum black, and ethylene and then ethane result. It was hoped at one time that this reaction would lead to the manufacture of alcohol from acetylene being achieved on a commercial basis; but it was found that it did not proceed with sufficient smoothness for the process to succeed, and a number of higher or condensation products were formed at the same time. It has been shown by Erdmann that the cost of production of alcohol from acetylene through this reaction must prove prohibitive, and he has indicated another reaction which he considered more promising. This is the conversion of acetylene by means of dilute sulphuric acid (3 volumes of concentrated acid to 7 volumes of water), preferably in the presence of mercuric oxide, to acetaldehyde. The yield, however, was not satisfactory, and the process does not appear to have passed beyond the laboratory stage. It has also been proposed to utilise the readiness with which acetylene polymerises on heating to form benzene, for the production of benzene commercially; but the relative prices of acetylene and benzene would have to be greatly changed from those now obtaining to make such a scheme successful. Acetylene also lends itself to the synthesis of phenol or carbolic acid. If the dry gas is passed slowly into fuming sulphuric acid, a sulpho-derivative results, of which the potash salt may be thrown down by means of alcohol. This salt has the formula C_2H_4O_2,S_2O_6K_2, and on heating it with caustic potash in an atmosphere of hydrogen, decomposing with excess of sulphuric acid, and distilling, phenol results and may be isolated. The product is, however, generally much contaminated with carbon, and the process, which was devised by Berthelot, does not appear to have been pursued commercially. Berthelot has also investigated the action of ordinary concentrated sulphuric acid on acetylene, and obtained various sulphonic derivatives. Schröter has made similar investigations on the action of strongly fuming sulphuric acid on acetylene. These investigations have not yet acquired any commercial significance. If a mixture of acetylene with either of the oxides of carbon is led through a red-hot tube, or if a similar mixture is submitted to the action of electric sparks when confined within a closed vessel at some pressure, a decomposition occurs, the whole of the carbon is liberated in the free state, while the hydrogen and oxygen combine to form water. Analogous reactions take place when either oxide of carbon is led over calcium carbide heated to a temperature of 200° or 250° C., the second product in this case being calcium oxide. The equations representing these actions are: C_2H_2 + CO = H_2O + 3C 2C_2H_2 + CO_2 = 2H_2O + 5C CaC_2 + CO = CaO + 3C 2CaC_2 + CO_2 = 2CaO + 5C By urging the temperature, or by increasing the pressure at which the gases are led over the carbide, the free carbon appears in the graphitic condition; at lower temperatures and pressures, it is separated in the amorphous state. These reactions are utilised in Frank's process for preparing a carbon pigment or an artificial graphite (_cf._ Chapter XII.). Parallel decompositions occur between carbon bisulphide and either acetylene or calcium carbide, all the carbon of both substances being eliminated, while the by-product is either sulphuretted hydrogen or calcium (penta) sulphide. Other organic bodies containing sulphur are decomposed in the same fashion, and it has been suggested by Ditz that if carbide could be obtained at a suitable price, the process might be made useful in removing sulphur (_i.e._, carbon bisulphide and thiophen) from crude benzol, in purifying the natural petroleum oil which contains sulphur, and possibly in removing "sulphur compounds" from coal-gas. COMPOUNDS WITH COPPER. By far the most important chemical reactions of acetylene in connexion with its use as an illuminant or fuel are those which it undergoes with certain metals, notably copper. It is known that if acetylene comes in contact with copper or with one of its salts, in certain conditions a compound is produced which, at least when dry, is highly explosive, and will detonate either when warmed or when struck or gently rubbed. The precise mechanism of the reaction, or reactions, between acetylene and copper (or its compounds), and also the character of the product, or products, obtained have been studied by numerous investigators; but their results have been inconclusive and sometimes rather contradictory, so that it can hardly be said that the conditions which determine or preclude the formation of an explosive compound and the composition of the explosive compound are yet known with certainty. Copper is a metal which yields two series of compounds, cuprous and cupric salts, the latter of which contain half the quantity of metal per unit of acid constituent that is found in the former. It should follow, therefore, that there are two compounds of copper with carbon, or copper carbides: cuprous carbide, Cu_2C_2, and cupric carbide, CuC_2. Acetylene reacts at ordinary temperatures with an ammoniacal solution of any cupric salt, forming a black cupric compound of uncertain constitution which explodes between 50° and 70° C. It is decomposed by dilute acids, yielding some polymerised substances. At more elevated temperatures other cupric compounds are produced which also give evidence of polymerisation. Cuprous carbide or acetylide is the reddish brown amorphous precipitate which is the ultimate product obtained when acetylene is led into an ammoniacal solution of cuprous chloride. This body is decomposed by hydrochloric acid, yielding acetylene; but of itself it is, in all probability, not explosive. Cuprous carbide, however, is very unstable and prone to oxidation; so that, given the opportunity, it combines with oxygen or hydrogen, or both, until it produces the copper acetylide, or acetylene-copper, which is explosive--a body to which Blochmann's formula C_2H_2Cu_2O is generally ascribed. Thus it should happen that the exact nature of the copper acetylene compound may vary according to the conditions in which it has been formed, from a substance that is not explosive at all at first, to one that is violently explosive; and the degree of explosiveness should depend on the greater exposure of the compound to air and moisture, or the larger amount of oxygen and moisture in the acetylene during its contact with the copper or copper salt. For instance, Mai has found that freshly made copper acetylide can be heated to 60° C. or higher without explosion; but that if the compound is exposed to air for a few hours it explodes on warming, while if warmed with oxygen it explodes on contact with acetylene. It is said by Mai and by Caro to absorb acetylene when both substances are dry, becoming so hot as to explode spontaneously. Freund and Mai have also observed that when copper acetylide which has been dried in contact with air for four or five hours at a temperature of 50° or 60° C. is allowed to explode in the presence of a current of acetylene, an explosion accompanied by light takes place; but it is always local and is not communicated to the gas, whether the latter is crude or pure. In contact with neutral or acid solutions of cuprous salts acetylene yields various double compounds differing in colour and crystallising power; but according to Chavastelon and to Caro they are all devoid of explosive properties. Sometimes a yellowish red precipitate is produced in solutions of copper salts containing free acid, but the deposit is not copper acetylide, and is more likely to be, at least in part, a copper phosphide--especially if the gas is crude. Hence acid solutions or preparations of copper salts may safely be used for the purification of acetylene, as is done in the case of frankoline, mentioned in Chapter V. It is clear that the amount of free acid in such a material is much more than sufficient to neutralise all the ammonia which may accompany the crude acetylene into the purifier until the material is exhausted in other respects; and moreover, in the best practice, the gas would have been washed quite or nearly free from ammonia before entering the purifier. From a practical aspect the possible interaction of acetylene and metallic copper has been investigated by Gerdes and by Grittner, whose results, again, are somewhat contradictory. Gerdes exposed neat acetylene and mixtures of acetylene with oil-gas and coal-gas to a pressure of nine or ten atmospheres for ten months at ordinary summer and winter temperatures in vessels made of copper and various alloys. Those metals and alloys which resisted oxidation in air resisted the attack of the gases, but the more corrodible substances were attacked superficially; although in no instance could an explosive body be detected, nor could an explosion be produced by heating or hammering. In further experiments the acetylene contained ammonia and moisture and Gerdes found that where corrosion took place it was due exclusively to the ammonia, no explosive compounds being produced even then. Grittner investigated the question by leading acetylene for months through pipes containing copper gauze. His conclusions are that a copper acetylide is always produced if impure acetylene is allowed to pass through neutral or ammoniacal solutions of copper; that dry acetylene containing all its natural impurities except ammonia acts to an equal extent on copper and its alloys, yielding the explosive compound; that pure and dry gas does not act upon copper or its alloys, although it is possible that an explosive compound may be produced after a great length of time. Grittner has asserted that an explosive compound may be produced when acetylene is brought into contact with such alloys of copper as ordinary brass containing 64.66 per cent. of copper, or red brass containing 74.46 per cent. of copper, 20.67 per cent. of zinc, and 4.64 per cent. of tin; whereas none is obtained when the metal is either "alpaca" containing 64.44 per cent. of copper, 18.79 per cent. of nickel, and 16.33 per cent. of zinc, or britannia metal composed of 91.7 per cent. of copper and 8.3 per cent. of tin. Caro has found that when pure dry acetylene is led for nine months over sheets or filings of copper, brass containing 63.2 per cent. of copper, red brass containing 73.8 per cent., so-called "alpaca-metal" containing 65.3 per cent., and britannia metal containing 90.2 per cent. of copper, no action whatever takes place at ordinary temperatures; if the gas is moist very small quantities of copper acetylide are produced in six months, whatever metal is tested, but the yield does not increase appreciably afterwards. At high temperatures condensation occurs between acetylene and copper or its alloys, but explosive bodies are not formed. Grittner's statement that crude acetylene, with or without ammonia, acts upon alloys of copper as well as upon copper itself, has thus been corroborated by Caro; but experience renders it tolerably certain that brass (and presumably gun-metal) is not appreciably attacked in practical conditions. Gerdes' failure to obtain an explosive compound in any circumstances may very possibly be explained by the entire absence of any oxygen from his cylinders and gases, so that any copper carbide produced remained unoxidised. Grittner's gas was derived, at least partially, from a public acetylene supply, and is quite likely to have been contaminated with air in sufficient quantity to oxidise the original copper compound, and to convert it into the explosive modification. For the foregoing reasons the use of unalloyed copper in the construction of acetylene generators or in the subsidiary items of the plant, as well as in burner fittings, is forbidden by statute or some quasi-legal enactment in most countries, and in others the metal has been abandoned for one of its alloys, or for iron or steel, as the case may be. Grittner's experiments mentioned above, however, probably explain why even alloys of copper are forbidden in Hungary. (_Cf._ Chapter IV., page 127.) When acetylene is passed over finely divided copper or iron (obtained by reduction of the oxide by hydrogen) heated to from 130° C. to 250° C., the gas is more or less completely decomposed, and various products, among which hydrogen predominates, result. Ethane and ethylene are undoubtedly formed, and certain homologues of them and of acetylene, as well as benzene and a high molecular hydrocarbon (C_7H_6)_n termed "cuprene," have been found by different investigators. Nearly the same hydrocarbons, and others constituting a mixture approximating in composition to some natural petroleums, are produced when acetylene is passed over heated nickel (or certain other metals) obtained by the reduction of the finely divided oxide. These observations are at present of no technical importance, but are interesting scientifically because they have led up to the promulgation of a new theory of the origin of petroleum, which, however, has not yet found universal acceptance. CHAPTER VII MAINS AND SERVICE-PIPES--SUBSIDIARY APPARATUS The process by which acetylene is produced, and the methods employed for purifying it and rendering it fit for consumption in dwelling-rooms, having been dealt with in the preceding pages, the present chapter will be devoted to a brief account of those items in the plant which lie between the purifier outlet and the actual burner, including the meter, governor, and pressure gauge; the proper sizes of pipe for acetylene; methods of laying it, joint-making, quality of fittings, &c.; while finally a few words will be said about the precautions necessary when bringing a new system of pipes into use for the first time. THE METER.--A meter is required either to control the working of a complete acetylene installation or to measure the volume of gas passing through one particular pipe, as when a number of consumers are supplied through separate services under agreement from a central supply plant. The control which may be afforded by the inclusion of a meter in the equipment of a domestic acetylene generating plant is valuable, but in practice will seldom be exercised. The meter records check the yield of gas from the carbide consumed in a simple and trustworthy manner, and also serve to indicate when the material in the purifier is likely to be approaching exhaustion. The meter may also be used experimentally to check the soundness of the service-pipes or the consumption of a particular burner or group of burners. Altogether it may be regarded as a useful adjunct to a domestic lighting plant, provided full advantage is taken of it. If, however, there is no intention to pay systematic attention to the records of the meter, it is best to omit it from such an installation, and so save its initial cost and the slight loss of pressure which its use involves on the gas passing through it. A domestic acetylene lighting plant can be managed quite satisfactorily without a meter, and as a multiplication of parts is undesirable in an apparatus which will usually be tended by someone not versed in technical operations, it is on the whole better to omit the meter in such an installation. Where the plant is supervised by a technical man, a meter may advisedly be included in the equipment. Its proper position in the train of apparatus is immediately after the purifier. A meter must not be used for unpurified or imperfectly purified acetylene, because the impurities attack the internal metallic parts and ultimately destroy them. The supply of acetylene to various consumers from a central generating station entails the fixing of a meter on each consumer's service-pipe, so that the quantity consumed by each may be charged for accordingly, just as in the case of public coal-gas supplies. There are two types of gas-meter in common use, either of which may, without essential alteration, be employed for measuring the volume of acetylene passing through a pipe. It is unnecessary to refer here at length to their internal mechanism, because their manufacture by other than firms of professed meter-makers is out of the question, and the user will be justified in accepting the mechanism as trustworthy and durable. Meters can always be had stamped with the seal of a local authority or other body having duly appointed inspectors under the Sales of Gas Act, and the presence of such a stamp on a meter implies that it has been officially examined and found to register quantities accurately, or not varying beyond 2 per cent. in favour of the seller, or 3 per cent, in favour of the consumer. [Footnote: It may be remarked that when a meter-- wet or dry--begins to register incorrectly by reason of old age or want of adjustment, its error is very often in the direction that benefits the customer, _i.e._, more gas passes through it than the dials record.] Hence a "stamped" meter may be regarded for practical purposes as affording a correct register of the quantities of gas passing through it. Except that the use of unalloyed copper in any part of the meter where it may come in contact with the gas must be wholly avoided, for the reason that copper is inadmissible in acetylene apparatus (_see_ Chapter VI.), the meters ordinarily employed for coal-gas serve quite well for acetylene. Obviously, however, since so very much less acetylene than coal-gas is consumed per burner, comparatively small meters only will be required even for large installations of acetylene lighting. This fact is now recognised by meter-makers, and meters of all suitable sizes can be obtained. It is desirable, if an ordinary coal-gas meter is being bought for use with acetylene, to have it subjected to a somewhat more rigorous test for soundness than is customary before "stamping" but the makers would readily be able to carry out this additional test. The two types of gas-meter are known as "wet" and "dry." The case of the wet meter is about hall-filled with water or other liquid, the level of which has to be maintained nearly constant. Several ingenious devices are in use for securing this constancy of level over a more or less extended period, but the necessity for occasional inspection and adjustment of the water-level, coupled with the stoppage of the passage of gas in the event of the water becoming frozen, are serious objections to the employment of the wet meter in many situations. The trouble of freezing may be avoided by substituting for the simple water an aqueous solution of glycerin, or mixture of glycerin with water, suitable strengths for which may be deduced from the table relating to the use of glycerin in holder seals given at the close of Chapter III. The dry meter, on the other hand, is very convenient, because it is not obstructed by the effects of frost, and because it acts for years without requiring attention. It is not susceptible of adjustment for measuring with so high a degree of accuracy as a good wet meter, but its indications are sufficiently correct to fall well within the legalised deviations already mentioned. Such errors, perhaps, are somewhat large for so costly and powerful a gas as acetylene, and they would be better reduced; but it is not so very often that a dry meter reaches its limit of inaccuracy. Whether wet or dry, the meter should be fixed in a place where the temperature is tolerably uniform, otherwise the volumes registered at different times will not bear the same ratio to the mass of gas (or volume at normal temperature), and the registrations will be misleading unless troublesome corrections to compensate for changes of temperature are applied. THE GOVERNOR, which can be dispensed with in most ordinary domestic acetylene lighting installations provided with a good gasholder of the rising-bell type, is designed to deliver the acetylene to a service-pipe at a uniform pressure, identical with that under which the burners develop their maximum illuminating efficiency. It must therefore both cheek the pressure anterior to it whenever that is above the determined limit to which it is set, and deliver to the efferent service-pipe acetylene at a constant pressure whether all or any number of the burners down to one only are in use. Moreover, when the pressure anterior to the governor falls to or below the determined limit, the governor should offer no resistance--entailing a loss of pressure to the passage of the acetylene. These conditions, which a perfect governor should fulfil, are not absolutely met by any simple apparatus at present in use, but so far as practical utility is concerned service governors which are readily obtainable are sufficiently good. They are broadly of two types, viz., those having a bell floating in a mercury seal, and those having a diaphragm of gas-tight leather or similar material, either the bell or the diaphragm being raised by the pressure of the gas. The action is essentially the same in both cases: the bell or the diaphragm is so weighted that when the pressure of the gas exceeds the predetermined limit the diaphragm or bell is lifted, and, through an attached rod and valve, brings about a partial closure of the orifice by which the gas flows into the bell or the diaphragm chamber. The valve of the governor, therefore, automatically throttles the gas-way more or less according to the difference in pressure before and after the apparatus, until at any moment the gas-way is just sufficient in area to pass the quantity of gas which any indefinite number of burners require at their fixed working pressure; passing it always at that fixed working pressure irrespective of the number of burners, and maintaining it constant irrespective of the amount of pressure anterior to the governor, or of any variations in that anterior pressure. In most patterns of service governor weights may be added when it is desired to increase the pressure of the effluent gas. It is necessary, in ordering a governor for an acetylene-supply, to state the maximum number of cubic feet per hour it will be required to pass, and approximately the pressure at which it will be required to deliver the gas to the service-pipe. This will usually be between 3 and 5 inches (instead of about 1 inch in the case of coal-gas), and if the anterior pressure is likely to exceed 10 inches, this fact should be stated also. The mercury-seal governors are usually the more trustworthy and durable, but they are more costly than those with leather diaphragms. The seal should have twice or thrice the depth it usually has for coal-gas. The governor should be placed where it is readily accessible to the man in charge of the installation, but where it will not be interfered with by irresponsible persons. In large installations, where a number of separate buildings receive service-pipes from one long main, each service-pipe should be provided with a governor. GASHOLDER PRESSURE.--In drawing up the specification or scheme of an acetylene installation, it is frequently necessary either to estimate the pressure which a bell gasholder of given diameter and weight will throw, or to determine what should be the weight of the bell of a gasholder of given diameter when the gas is required to be delivered from it at a particular pressure. The gasholder of an acetylene installation serves not only to store the gas, but also to give the necessary pressure for driving it through the posterior apparatus and distributing mains and service-pipes. In coal-gas works this office is generally given over wholly or in part to a special machine, known as the exhauster, but this machine could not be advantageously employed for pumping acetylene unless the installation were of very great magnitude. Since, therefore, acetylene is in practice always forced through mains and service-pipes in virtue of the pressure imparted to it by the gasholder and since, for reasons already given, only the rising-bell type of gasholder can be regarded as satisfactory, it becomes important to know the relations which subsist between the dimensions and weight of a gasholder bell and the pressure which it "throws" or imparts to the contained gas. The bell must obviously be a vessel of considerable weight if it is to withstand reasonable wear and tear, and this weight will give a certain hydrostatic pressure to the contained gas. If the weight of the bell is known, the pressure which it will give can be calculated according to the general law of hydrostatics, that the weight of the water displaced must be equal to the weight of the floating body. Supposing for the moment that there are no other elements which will have to enter into the calculation, then if _d_ is the diameter in inches of the (cylindrical) bell, the surface of the water displaced will have an area of _d^2_ x 0.7854. If the level of the water is depressed _p_ inches, then the water displaced amounts to _p_(_d^2_ x 0.7854) cubic inches, and its weight will be (at 62° F.): (0.7854_pd^2_ x 0.03604) = 0.028302_pd^2_ lb. Consequently a bell which is _d_ inches in diameter, and gives a pressure of _p_ inches of water, will weigh 0.028302_pd^2_ lb. Or, if W = the weight of the bell in lb., the pressure thrown by it will be W/0.028302_d^2_ or 35.333W/_d^2_. This is the fundamental formula, which is sometimes given as _p_ = 550W/_d^2_, in which W = the weight of the bell in tons, and _d_ the diameter in feet. This value of _p_, however, is actually higher than the holder would give in practice. Reductions have to be made for two influences, viz., the lifting power of the contained gas, which is lighter than air, and the diminution in the effective weight of so much of the bell as is immersed in water. The effect of these influences was studied by Pole, who in 1839 drew up some rules for calculating the pressure thrown by a gasholder of given dimensions and weight. These rules form the basis of the formula which is commonly used in the coal-gas industry, and they may be applied, _mutatis mutandis_, to acetylene holders. The corrections for both the influences mentioned vary with the height at which the top of the gasholder bell stands above the level of the water in the tank. Dealing first with the correction for the lifting power of the gas, this, according to Pole, is a deduction of _h_(1 - _d_)/828 where _d_ is the specific gravity of the gas and _h_ the height (in inches) of the top of the gasholder above the water level. This strictly applies only to a flat-topped bell, and hence if the bell has a crown with a rise equal to about 1/20 of the diameter of the bell, the value of _h_ here must be taken as equal to the height of the top of the sides above the water-level (= _h'_), plus the height of a cylinder having the same capacity as the crown, and the same diameter as the bell, that is to say, _h_=_h'_ + _d_/40 where _d_ = the diameter of the bell. The specific gravity of commercially made acetylene being constantly very nearly 0.91, the deduction for the lifting power of the gas becomes, for acetylene gasholders, 0.0001086_h_ + 0.0000027_d_, where _h_ is the height in inches of the top of the sides of the bell above the water- level, and _d_ is the diameter of the bell. Obviously this is a negligible quantity, and hence this correction may be disregarded for all acetylene gasholders, whereas it is of some importance with coal-gas and other gases of lower specific gravity. It is therefore wrong to apply to acetylene gasholders formulæ in which a correction for the lifting power of the gas has been included when such correction is based on the average specific gravity of coal-gas, as is the case with many abbreviated gasholder pressure formulæ. The correction for the immersion of the sides of the bell is of greater magnitude, and has an important practical significance. Let H be the total height in inches of the side of the gasholder, _h_ the height in inches of the top of the sides of the gasholder above the water-level, and _w_ = the weight of the sides of the gasholder in lb.; then, for any position of the bell, the proportion of the total height of the sides immersed (H - _h_)/H, and the buoyancy is (H - _h_)/H x _w_/S + pi/4_d^2_, in which S = the specific gravity of the material of which the bell is made. Assuming the material to be mild steel or wrought iron, having a specific gravity of 7.78, the buoyancy is (4_w_(H - _h_)) / (7.78Hpi_d^2_) lb. per square inch (_d_ being inches and _w_ lb.), which is equivalent to (4_w_(H - _h_)) / (0.03604 x 7.78Hpi_d^2_) = (4.54_w_(H - _h_)) / (H_d^2_) inches of water. Hence the complete formula for acetylene gasholders is: _p_ = 35.333W / _d^2_ - 4.54_w_(H - _h_) / H_d^2_ It follows that _p_ varies with the position of the bell, that is to say, with the extent to which it is filled with gas. It will be well to consider how great this variation is in the case of a typical acetylene holder, as, if the variation should be considerable, provision must be made, by the employment of a governor on the outlet main or otherwise, to prevent its effects being felt at the burners. Now, according to the rules of the "Acetylen-Verein" (_cf._ Chapter IV.), the bells of holders above 53 cubic feet in capacity should have sides 1.5 mm. thick, and crowns 0.5 mm. thicker. Hence for a holder from 150 to 160 cubic feet capacity, supposing it to be 4 feet in diameter and about 12 feet high, the weight of the sides (say of steel No. 16 S.W.G. = 2.66 lb. per square foot) will be not less than 12 x 4pi x 2.66 = 401 lb. The weight of the crown (say of steel No. 14 S.W.G. = 3.33 lb. per square foot) will be not less than about 12.7 x 3.33 = about 42 lb. Hence the total weight of holder = 401 + 42 = 443 lb. Then if the holder is full, _h_ is very nearly equal to H, and _p_ = (35.333 x 443) / 48^2 = 6.79 inches. If the holder stands only 1 foot above the water-level, then _p_ = 6.79 - (4.54 x 401 (144 - 12)) / (144 x 48^2) = 6.79 - 0.72 = 6.07 inches. The same result can be arrived at without the direct use of the second member of the formula: For instance, the weight of the sides immersed is 11 x 4pi x 2.66 = 368 lb., and taking the specific gravity of mild steel at 7.78, the weight of water displaced is 368 / 7.78 = 47.3 lb. Hence the total effective weight of the bell is 443 - 47.3 = 395.7 lb., and _p_ = (35.333 x 395.7) / 48^2 = 6.07 inches. [Footnote: If the sealing liquid in the gasholder tank is other than simple water, the correction for the immersion of the sides of the bell requires modification, because the weight of liquid displaced will be _s'_ times as great as when the liquid is water, if _s'_ is the specific gravity of the sealing liquid. For instance, in the example given, if the sealing liquid were a 16 per cent. solution of calcium chloride, specific gravity 1.14 (_vide_ p. 93) instead of water, the weight of liquid displaced would be 1.14 (368 / 7.78) = 53.9 lb., and the total effective weight of the bell = 443 - 53.9 = 389.1 lb. Therefore _p_ becomes = (35.333 x 389.1) / 48^2 = 5.97 inches, instead of 6.07 inches.] The value of _p_ for any position of the bell can thus be arrived at, and if the difference between its values for the highest and for the lowest positions of the bell exceeds 0.25 inch, [Footnote: This figure is given as an example merely. The maximum variation in pressure must be less than one capable of sensibly affecting the silence, steadiness, and economy of the burners and stoves, &c., connected with the installation.] a governor should be inserted in the main leading from the holder to the burners, or one of the more or less complicated devices for equalising the pressure thrown by a holder as it rises and falls should be added to the holder. Several such devices were at one time used in connexion with coal-gas holders, and it is unnecessary to describe them in this work, especially as the governor is practically the better means of securing uniform pressure at the burners. It is frequently necessary to add weight to the bell of a small gasholder in order to obtain a sufficiently high pressure for the distribution of acetylene. It is best, having regard to the steadiness of the bell, that any necessary weighting of it should be done near its bottom rim, which moreover is usually stiffened by riveting to it a flange or curb of heavier gauge metal. This flange may obviously be made sufficiently stout to give the requisite additional weighting. As the flange is constantly immersed, its weight must not be added to that of the sides in computing the value of _w_ for making the correction of pressure in respect of the immersion of the bell. Its effective weight in giving pressure to the contained gas is its actual weight less its actual weight divided by its specific gravity (say 7.2 for cast iron, 7.78 for wrought iron or mild steel, or 11.4 for lead). Thus if _x_ lb. of steel is added to the rim its weight in computing the value of W in the formula _p_ = 35.333W / _d_^2 should be taken as x - x / 7.78. If the actual weight is 7.78 lb., the weight taken for computing W is 7.78 - 1 = 6.78 lb. THE PRESSURE GAUGE.--The measurement of gas pressure is effected by means of a simple instrument known as a pressure gauge. It comprises a glass U- tube filled to about half its height with water. The vacant upper half of one limb is put in communication with the gas-supply of which the pressure is to be determined, while the other limb remains open to the atmosphere. The difference then observed, when the U-tube is held vertical, between the levels of the water in the two limbs of the tube indicates the difference between the pressure of the gas-supply and the atmospheric pressure. It is this _difference_ that is meant when the _pressure_ of a gas in a pipe or piece of apparatus is spoken of, and it must of necessity in the case of a gas-supply have a positive value. That is to say, the "pressure" of gas in a service-pipe expresses really by how much the pressure in the pipe _exceeds_ the atmospheric pressure. (Pressures less than the atmospheric pressure will not occur in connexion with an acetylene installation, unless the gasholder is intentionally manipulated to that end.) Gas pressures are expressed in terms of inches head or pressure of water, fractions of an inch being given in decimals or "tenths" of an inch. The expression "tenths" is often used alone, thus a pressure of "six-tenths" means a pressure equivalent to 0.6 inch head of water. The pressure gauge is for convenience provided with an attached scale on which the pressures may be directly read, and with a connexion by which the one limb is attached to the service-pipe or cock where the pressure is to be observed. A portable gauge of this description is very useful, as it can be attached by means of a short piece of flexible tubing to any tap or burner. Several authorities, including the British Acetylene Association, have recommended that pressure gauges should not be directly attached to generators, because of the danger that the glass might be fractured by a blow or by a sudden access of heat. Such breakage would be followed by an escape of gas, and might lead to an accident. Fixed pressure gauges, however, connected with every item of a plant are extremely useful, and should be employed in all large installations, as they afford great aid in observing and controlling the working, and in locating the exact position of any block. All danger attending their use can be obviated by having a stopcock between the gauge inlet and the portion of the plant to which it is attached; the said stopcock being kept closed except when it is momentarily opened to allow of a reading being taken. As an additional precaution against its being left open, the stopcock may be provided with a weight or spring which automatically closes the gas-way directly the observer's hand is removed from the tap. In the best practice all the gauges will be collected together on a board fastened in some convenient spot on the wall of the generator-house, each gauge being connected with its respective item of the plant by means of a permanent metallic tube. The gauges must be filled with pure water, or with a liquid which does not differ appreciably in specific gravity from pure water, or the readings will be incorrect. Greater legibility will be obtained by staining the water with a few drops of caramel solution, or of indigo sulphate (indigo carmine); or, in the absence of these dyes, with a drop or two of common blue-black writing ink. If they are not erected in perfectly frost-free situations, the gauges may be filled with a mixture of glycerin and pure alcohol (not methylated spirit), with or without a certain proportion of water, which will not freeze at any winter temperature. The necessary mixture, which must have a density of exactly 1.00, could be procured from any pharmacist. It is the pressure as indicated by the pressure gauge which is referred to in this book in all cases where the term "pressure of the gas" or the like is used. The quantity of acetylene which will flow in a given time from the open end of a pipe is a function of this pressure, while the quantity of acetylene escaping through a tiny hole or crack or a burner orifice also depends on this total pressure, though the ratio in this instance is not a simple one, owing to the varying influence of friction between the issuing gas and the sides of the orifice. Where, however, acetylene or other gas is flowing through pipes or apparatus there is a loss of energy, indicated by a falling off in the pressure due to friction, or to the performance of work, such as actuating a gas-meter. The extent of this loss of energy in a given length of pipe or in a meter is measured by the difference between the pressures of the gas at the two ends of the pipe or at the inlet and outlet of the meter. This difference is the "loss" or "fall" of pressure, due to friction or work performed, and is spoken of as the "actuating" pressure in regard to the passage of gas through the stretch of pipe or meter. It is a measure of the energy absorbed in actuating the meter or in overcoming the friction. (Cf. footnote, Chapter II., page 54.) DIMENSIONS OF MAINS.--The diameter of the mains and service-pipes for an acetylene installation must be such that the main or pipe will convey the maximum quantity of the gas likely to be required to feed all the burners properly which are connected to it, without an excessive actuating pressure being called for to drive the gas through the main or pipe. The flow of all gases through pipes is of course governed by the same general principles; and it is only necessary in applying these principles to a particular gas, such as acetylene, to know certain physical properties of the gas and to make due allowance for their influence. The general principles which govern the flow of a gas through pipes have been exhaustively studied on account of their importance in relation to the distribution of coal-gas and the supply of air for the ventilation of places where natural circulation is absent or deficient. It will be convenient to give a very brief reference to the way in which these principles have been ascertained and applied, and then to proceed to the particular case of the distribution of acetylene through mains and service-pipes. The subject of "The Motion of Fluids in Pipes" was treated in a lucid and comprehensive manner in an Essay by W. Pole in the _Journal of Gas Lighting_ during 1852, and his conclusions have been generally adopted by gas engineers ever since. He recapitulated the more important points of this essay in the course of some lectures delivered in 1872, and one or other of these two sources should be consulted for further information. Briefly, W. Pole treated the question in the following manner: The practical question in gas distribution is, what quantity of gas will a given actuating pressure cause to flow along a pipe of given length and given diameter? The solution of this question allows of the diameters of pipes being arranged so that they will carry a required quantity of gas a given distance under the actuating pressure that is most convenient or appropriate. There are five quantities to be dealt with, viz.: (1) The length of pipe = _l_ feet. (2) The internal diameter of the pipe = _d_ inches. (3) The actuating pressure = _h_ inches of head of water. (4) The specific gravity or density of the gas = _d_ times that of air. (5) The quantity of gas passing through the pipe--Q cubic feet per hour. This quantity is the product of the mean velocity of the gas in the pipe and the area of the pipe. The only work done in maintaining the flow of gas along a pipe is that required to overcome the friction of the gas on the walls of the pipe, or, rather, the consequential friction of the gas on itself, and the laws which regulate such friction have not been very exhaustively investigated. Pole pointed out, however, that the existing knowledge on the point at the time he wrote would serve for the purpose of determining the proper sizes of gas-mains. He stated that the friction (1) is proportional to the area of rubbing surface (viz., pi_ld_); (2) varies with the velocity, in some ratio greater than the first power, but usually taken as the square; and (3) is assumed to be proportional to the specific gravity of the fluid (viz., _s_). Thus the force (_f_) necessary to maintain the motion of the gas in the pipe is seen to vary (1) as pi_ld_, of which pi is a constant; (2) as _v^2_, where _v_ = the velocity in feet per hour; and (3) as _s_. Hence, combining these and deleting the constant pi, it appears that _f_ varies as _ldsv^2_. Now the actuating force is equal to _f_, and is represented by the difference of pressure at the two ends of the pipe, _i.e._, the initial pressure, viz., that at the place whence gas is distributed or issues from a larger pipe will be greater by the quantity _f_ than the terminal pressure, viz., that at the far end of the pipe where it branches or narrows to a pipe or pipes of smaller size, or terminates in a burner. The terminal pressure in the case of service-pipes must be settled, as mentioned in Chapter II., broadly according to the pressure at which the burners in use work best, and this is very different in the case of flat-flame burners for coal-gas and burners for acetylene. The most suitable pressure for acetylene burners will be referred to later, but may be taken as equal to p_0 inches head of water. Then, calling the initial pressure (_i.e._, at the inlet head of service-pipe) p_1, it follows that p_1 - p_0 = _f_. Now the cross-section of the pipe has an area (pi/4)_d^2_, and if _h_ represents the difference of pressure between the two ends of the pipe per square inch of its area, it follows that _f_ = _h(pi/4)d^2_. But since _f_ has been found above to vary as _ldsv^2_ , it is evident that _h(pi/4)d^2_ varies as _ldsv^2_. Hence _v^2_ varies as _hd/ls_, and putting in some constant M, the value of which must be determined by experiment, this becomes _v^2_ = M_hd/ls_. The value of M deduced from experiments on the friction of coal-gas in pipes was inserted in this equation, and then taking Q = pi/4_d^2v_, it was found that for coal-gas Q = 780(_hd/sl_)^(1/2) This formula, in its usual form, is Q = 1350_d^2_(_hd/sl_)^(1/2) in which _l_ = the length of main in yards instead of in feet. This is known as Pole's formula, and has been generally used for determining the sizes of mains for the supply of coal-gas. For the following reasons, among others, it becomes prudent to revise Pole's formula before employing it for calculations relating to acetylene. First, the friction of the two gases due to the sides of a pipe is very different, the coefficient for coal-gas being 0.003, whereas that of acetylene, according to Ortloff, is 0.0001319. Secondly, the mains and service-pipes required for acetylene are smaller, _cateria paribus_, than those needed for coal-gas. Thirdly, the observed specific gravity of acetylene is 0.91, that of air being unity, whereas the density of coal-gas is about 0.40; and therefore, in the absence of direct information, it would be better to base calculations respecting acetylene on data relating to the flow of air in pipes rather than upon such as are applicable to coal-gas. Bernat has endeavoured to take these and similar considerations into account, and has given the following formula for determining the sizes of pipes required for the distribution of acetylene: Q = 0.001253_d^2_(_hd/sl_)^(1/2) in which the symbols refer to the same quantities as before, but the constant is calculated on the basis of Q being stated in cubic metres, l in metres, and d and h in millimetres. It will be seen that the equation has precisely the same shape as Pole's formula for coal-gas, but that the constant is different. The difference is not only due to one formula referring to quantities stated on the metric and the other to the same quantities stated on the English system of measures, but depends partly on allowance having been made for the different physical properties of the two gases. Thus Bernat's formula, when merely transposed from the metric system of measures to the English (_i.e._, Q being cubic feet per hour, _l_ feet, and _d_ and _h_ inches) becomes Q = 1313.5_d^2_(_hd/sl_)^(1/2) or, more simply, Q = 1313.4(_hd^5/sl_)^(1/2) But since the density of commercially-made acetylene is practically the same in all cases, and not variable as is the density of coal-gas, its value, viz., 0.91, may be brought into the constant, and the formula then becomes Q = 1376.9(_hd^5/l_)^(1/2) Bernat's formula was for some time generally accepted as the most trustworthy for pipes supplying acetylene, and the last equation gives it in its simplest form, though a convenient transposition is d = 0.05552(Q^2_l/h_)^(1/5) Bernat's formula, however, has now been generally superseded by one given by Morel, which has been found to be more in accordance with the actual results observed in the practical distribution of acetylene. Morel's formula is D = 1.155(Q^2_l/h_)^(1/5) in which D = the diameter of the pipe in centimetres, Q = the number of cubic metres of gas passing per hour, _l_ = the length of pipe in metres, and _h_ = the loss of pressure between the two ends of the pipe in millimetres. On converting tins formula into terms of the English system of measures (_i.e._, _l_ feet, Q cubic feet, and _h_ and _d_ inches) it becomes (i) d = 0.045122(Q^2_l/h_)^(1/5) At first sight this formula does not appear to differ greatly from Bernat's, the only change being that the constant is 0.045122 instead of 0.05552, but the effect of this change is very great--for instance, other factors remaining unaltered, the value of Q by Morel's formula will be 1.68 times as much as by Bernat's formula. Transformations of Morel's formula which may sometimes be more convenient to apply than (i) are: (ii) Q = 2312.2(_hd^5/l_)^(1/2) (iii) _h_ = 0.000000187011(Q^2_l/d^5_) and (iv) _l_ = 5,346,340(_hd^5_/Q^2) In order to avoid as far as possible expenditure of time and labour in repeating calculations, tables have been drawn up by the authors from Morel's formulæ which will serve to give the requisite information as to the proper sizes of pipes to be used in those cases which are likely to be met with in ordinary practice. These tables are given at the end of this chapter. When dealing with coal-gas, it is highly important to bear in mind that the ordinary distributing formulæ apply directly only when the pipe or main is horizontal, and that a rise in the pipe will be attended by an increase of pressure at the upper end. But as the increase is greater the lower the density of the gas, the disturbing influence of a moderate rise in a pipe is comparatively small in the case of a gas of so high a density as acetylene. Hence in most instances it will be unnecessary to make any allowance for increase of pressure due to change of level. Where the change is very great, however, allowance may advisedly be made on the following basis: The pressure of acetylene in pipes increases by about one-tenth of an inch (head of water) for every 75 feet rise in the pipe. Hence where acetylene is supplied from a gasholder on the ground-level to all floors of a house 75 feet high, a burner at the top of the house will ordinarily receive its supply at a pressure greater by one-tenth of an inch than a burner in the basement. Such a difference, with the relatively high pressures used in acetylene supplies, is of no practical moment. In the case of an acetylene-supply from a central station to different parts of a mountainous district, the variations of pressure with level should be remembered. The distributing formulæ also assume that the pipe is virtually straight; bends and angles introduce disturbing influences. If the bend is sharp, or if there is a right-angle, an allowance should be made if it is desired to put in pipes of the smallest permissible dimensions. In the case of the most usual sizes of pipes employed for acetylene mains or services, it will suffice to reckon that each round or square elbow is equivalent in the resistance it offers to the flow of gas to a length of 5 feet of pipe of the same diameter. Hence if 5 feet is added to the actual length of pipe to be laid for every bond or elbow which will occur in it, and the figure so obtained is taken as the value of _l_ in formulæ (i), (ii), or (iii), the values then found for Q, _d_, or _h_ will be trustworthy for all practical purposes. It may now be useful to give an example of the manner of using the foregoing formulæ when the tables of sizes of pipes are not available. Let it be supposed that an institution is being equipped for acetylene lighting; that 50 burners consuming 0.70 cubic foot, and 50 consuming 1.00 cubic foot of acetylene per hour may be required in use simultaneously; that a pressure of at least 2-1/2 inches is required at all the burners; that for sufficient reasons it is considered undesirable to use a higher distributing pressure than 4 inches at the gasholder, outlet of the purifiers, or initial governor (whichever comes last in the train of apparatus); that the gasholder is located 100 feet from the main building of the institution, and that the trunk supply-pipe through the latter must be 250 feet in length, and the supplies to the burners, either singly or in groups, be taken from this trunk pipe through short lengths of tubing of ample size. What should be the diameter of the trunk pipe, in which it will be assumed that ten bonds or elbows are necessary? In the first instance, it is convenient to suppose that the trunk pipe may be of uniform diameter throughout. Then the value of _l_ will be 100 (from gasholder to main building) + 250 (within the building) + 50 (equivalent of 10 elbows) = 400. The maximum value of Q will be (50 x 0.7) + (50 x 1.0) = 85; and the value of _h_ will be 1 - 2.5 - 1.5. Then using formula (i), we have: d = 0.045122((85^2 x 400)/1.5)^(1/5) = 0.045122(1,926,667)^(1/5) = 0.045122 x 18.0713 = 0.8154. The formula, therefore, shows that the pipe should have an internal diameter of not less than 0.8154 inch, and consequently 1 inch (the next size above 0.8154 inch) barrel should be used. If the initial pressure (i.e., at outlet of purifiers) could be conveniently increased from 4 to 4.8 inches, 3/4 inch barrel could be employed for the service-pipe. But if connexions for burners were made immediately the pipe entered the building, these burners would then be supplied at a pressure of 4.2 inches, while those on the extremity of the pipe would, when all burners were in use, be supplied at a pressure of only 2.5 inches. Such a great difference of pressure is not permissible at the several burners, as no type of burner retains its proper efficiency over more than a very limited range of pressure. It is highly desirable in the case of the ordinary Naphey type of burner that all the burners in a house should be supplied at pressures which do not differ by more than half an inch; hence the pipes should, wherever practicable, be of such a size that they will pass the maximum quantity of gas required for all the burners which will ever be in use simultaneously, when the pressure at the first burner connected to the pipe after it enters the house is not more than half an inch above the pressure at the burner furthermost removed from the first one, all the burner-taps being turned on at the time the pressures are observed. If the acetylene generating plant is not many yards from the building to be supplied, it is a safe rule to calculate the size of pipes required on the basis of a fall of pressure of only half an inch from the outlet of the purifiers or initial governor to the farthermost burner. The extra cost of the larger size of pipe which the application of this rule may entail will be very slight in all ordinary house installations. VELOCITY OF FLOW IN PIPES.--For various purposes, it is often desirable to know the mean speed at which acetylene, or any other gas, is passing through a pipe. If the diameter of the pipe is _d_ inches, its cross-sectional area is _d^2_ x 0.7854 square inches; and since there are 1728 cubic inches in 1 cubic foot, that quantity of gas will occupy in a pipe whose diameter is _d_ inches a length of 1728/(_d^2_ x 0.7854) linear inches or 183/_d^2_^ linear feet. If the gas is in motion, and the pipe is delivering Q cubic feet per hour, since there are 3600 seconds of time in one hour, the mean speed of the gas becomes 183/_d^2_ x Q/3600 = Q/(19 x 7_d^2_) linear feet per second. This value is interesting in several ways. For instance, taking a rough average of Le Chatelier's results, the highest speed at which the explosive wave proceeds in a mixture of acetylene and air is 7 metres or 22 feet per second. Now, even if a pipe is filled with an acetylene-air mixture of utmost explosibility, an explosion cannot travel backwards from B to A in that pipe, if the gas is moving from A to B at a speed of over 22 feet per second. Hence it may be said that no explosion can occur in a pipe provided Q/(19.7_d^2_) = 22 or more; _i.e._, Q/_d^2_=433.4 In plain language, if the number of cubic feet passing through the pipe per hour divided by the square of the diameter of the pipe is at least 433.4, no explosion can take place within that pipe, even if the gas is highly explosive and a light is applied to its exit. In Chapter VI. are given the explosive limits of acetylene-air mixtures as influenced by the diameter of the tube containing them. If we possessed a similar table showing the speed of the explosive wave in mixtures of known composition, the foregoing formulæ would enable us to calculate the minimum speed which would insure absence of explosibility in a supply-pipe of any given diameter throughout its length, or at its narrowest part. It would not, however, be possible simply by increasing the forward speed of an explosive mixture of acetylene and air to a point exceeding that of its explosion velocity to prevent all danger of firing back in an atmospheric burner tube. A much higher pressure than is usually employed in gas-burners, other than blowpipes, would be needed to confer a sufficient degree of velocity upon the gas, a pressure which would probably fracture any incandescent mantle placed in the flame. SERVICE-PIPES AND MAINS.--The pipes used for the distribution of acetylene must be sound in themselves, and their joints perfectly tight. Higher pressures generally prevail in acetylene service-pipes within a house than in coal-gas service-pipes, while slight leaks are more offensive and entail a greater waste of resources. Therefore it is uneconomical, as well as otherwise objectionable, to employ service-pipes or fittings for acetylene which are in the least degree unsound. Unfortunately ordinary gas-barrel is none too sound, nor well-threaded, and the taps and joints of ordinary gas-fittings are commonly leaky. Hence something better should invariably be used for acetylene. What is known as "water" barrel, which is one gauge heavier than gas-barrel of the same size, may be adopted for the service-pipes, but it is better to incur a slight extra initial expense and to use "steam" barrel, which is of still heavier gauge and is sounder than either gas or water-pipe. All elbows, tees, &c., should be of the same quality. The fitters' work in making the joints should be done with the utmost care, and the sloppy work often passed in the case of coal-gas services must on no account be allowed. It is no exaggeration to say that the success of an acetylene installation, from the consumer's point of view, will largely, if not principally, depend on the tightness of the pipes in his house. The statement has been made that the "paint" used by gas-fitters, _i.e._, the mixture of red and white lead ground in "linseed" oil, is not suitable for employment with acetylene, and it has been proposed to adopt a similar material in which the vehicle is castor-oil. No good reason has been given for the preference for castor-oil, and the troubles which have arisen after using ordinary paint may be explained partly on the very probable assumption that the oil was not genuine linseed, and so did not dry, and partly on the fact that almost entire reliance was placed on the paint for keeping the joint sound. Joints for acetylene, like those for steam and high-pressure water, must be made tight by using well-threaded fittings, so as to secure metallic contact between pipe and socket, &c.; the paint or spun-yarn is only an additional safeguard. In making a faced joint, washers of (say, 7 lb) lead, or coils of lead-wire arc extremely convenient and quite trustworthy; the packing can be used repeatedly. LEAKAGE.--Broadly speaking, it may be said that the commercial success of any village acetylene-supply--if not that of all large installations-- depends upon the leakage being kept within moderate limits. It follows from what was stated in Chapter VI. about the diffusion of acetylene, that from pipes of equal porosity acetylene and coal-gas will escape at equal rates when the effective pressure in the pipe containing acetylene is double that in the pipe containing coal-gas. The loss of coal-gas by leakage is seldom less than 5 per cent. of the volume passed into the main at the works; and provided a village main delivering acetylene is not unduly long in proportion to the consumption of gas--or, in other words, provided the district through which an acetylene distributing main passes is not too sparsely populated--the loss of acetylene should not exceed the same figure. Caro holds that the loss of gas by leakage from a village installation should be quoted in absolute figures and not as a percentage of the total make as indicated by the works meter, because that total make varies so largely at different periods of the year, while the factors which determine the magnitude of the leakage are always identical; and therefore whereas the actual loss of gas remains the same, it is represented to be more serious in the summer than in the winter. Such argument is perfectly sound, but the method of returning leakage as a percentage of the make has been employed in the coal-gas industry for many years, and as it does not appear to have led to any misunderstanding or inconvenience, there is no particular reason for departing from the usual practice in the case of acetylene where the conditions as to uniform leakage and irregular make are strictly analogous. Caro has stated that a loss of 15 to 20 litres per kilometre per hour (_i.e._, of 0.85 to 1.14 cubic feet per mile per hour) from an acetylene distributing main is good practice; but it should be noted that much lower figures have been obtained when conditions are favourable and when due attention has been devoted to the fitters' work. In one of the German village acetylene installations where the matter has been carefully investigated (Döse, near Cuxhaven), leakage originally occurred at the rate of 7.3 litres per kilometre per hour in a main 8.5 kilometres, or 5.3 miles, long and 4 to 2 inches in diameter; but it was reduced to 5.2 litres, and then to 3.12 litres by tightening the plugs of the street lantern and other gas cocks. In British units, these figures are 0.415, 0.295, and 0.177 cubic foot per mile per hour. By calculation, the volume of acetylene generated in this village would appear to have been about 23,000 cubic feet per mile of main per year, and therefore it may be said that the proportion of gas lost was reduced by attending to the cocks from 15.7 per cent, to 11.3 per cent, and then to 6.8 per cent. At another village where the main was 2.5 kilometres long, tests extending over two months, when the public lamps were not in use, showed the leakage to be 4.4 litres per kilometre per hour, _i.e._, 1.25 cubic foot per mile per hour, when the annual make was roughly 46,000 cubic feet per mile of main. Here, the loss, calculated from the direct readings of the works motor, was 4.65 per cent. When all the fittings, burners excepted, have been connected, the whole system of pipes must be tested by putting it under a gas (or air) pressure of 9 or 12 inches of water, and observing on an attached pressure gauge whether any fall in pressure occurs within fifteen minutes after the main inlet tap has been shut. The pressure required for this purpose can be obtained by temporarily weighting the holder, or by the employment of a pump. If the gauge shows a fall of pressure of one quarter of an inch or more in these circumstances, the pipes must be examined until the leak is located. In the presence of a meter, the installation can conveniently be tested for soundness by throwing into it, through the meter, a pressure of 12 inches or so of water from the weighted holder, then leaving the inlet cock open, and observing whether the index hand on the lowest dial remains perfectly stationary for a quarter of an hour--movement of the linger again indicating a leak. The search for leaks must never be made with a light; if the pipes are full of air this is useless, if full of gas, criminal in its stupidity. While the whole installation is still under a pressure of 12 inches thrown from the loaded holder, whether it contains air or gas, first all the likely spots (joints, &c.), then the entire length of pipe is carefully brushed over with strong soapy water, which will produce a conspicuous "soap- bubble" wherever the smallest flaw occurs. The tightness of a system of pipes put under pressure from a loaded holder cannot be ascertained safely by observing the height of the bell, and noting if it falls on standing. Even if there is no issue of gas from the holder, the position of the bell will alter with every variation in temperature of the stored gas or surrounding air, and with every movement of the barometer, rising as the temperature rises and as the barometer falls, and _vice versâ_, while, unless the water in the seal is saturated with whatever gas the holder contains, the bell will steadily drop a little an part of its contents are lost by dissolution in the liquid. PIPES AND FITTINGS.--As a general rule it is unadvisable to use lead or composition pipe for permanent acetylene connexions. If exposed, it is liable to be damaged, and perhaps penetrated by a blow, and if set in the wall and covered with paper or panel it is liable to be pierced if nails or tacks should at any time be driven into the wall. There is also an increased risk in case of fire, owing to its ready fusibility. If used at all--and it has obvious advantages--lead or composition piping should be laid on the surface of the walls, &c., and protected from blows, &c., by a light wooden casing, outwardly resembling the wooden coverings for electric lighting wires. It has been a common practice, in laying the underground mains required for supplying the villages which are lighted by means of acetylene from a central works in different parts of France, to employ lead pipes. The plan is economical, but in view of the danger that the main might be flattened by the weight of heavy traction-engines passing over the roads, or that it might settle into local dips from the same cause or from the action of subterranean water, in which dips water would be constantly condensing in cold weather, the use of lead for this purpose cannot be recommended. Steam-barrel would be preferable to cast pipe, because permanently sound joints are easier to make in the former, and because it is not so brittle. The fittings used for acetylene must have perfectly sound joints and taps, for the same reasons that the service-pipes must be quite sound. Common gas-fittings will not do, the joints, taps, ball-sockets, &c., are not accurately enough ground to prevent leakage. They may in many cases be improved by regrinding, but often the plug and barrel are so shallow that it is almost impossible to ensure soundness. It is therefore better to procure fittings having good taps and joints in the first instance; the barrels should be long, fairly wide, and there should be no sensible "play" between plug and barrel when adjusted so that the plug turns easily when lightly lubricated. Fittings are now being specially made for acetylene, which is a step in the right direction, because, in addition to superior taps and joints being essential, smaller bore piping and smaller through-ways to the taps than are required for coal-gas serve for acetylene. It is perhaps advisable to add that wherever a rigid bracket or fitting will answer as well as a jointed one, the latter should on no account be used; also water-slide pendants should never be employed, as they are fruitful of accidents, and their apparent advantages are for the most part illusory. Ball-sockets also should be avoided if possible; if it is absolutely necessary to have a fitting with a ball-socket, the latter should have a sleeve made of a short length of sound rubber-tubing of a size to give a close fit, slipped over so as to join the ball portion to the socket portion. This sleeve should be inspected once a quarter at least, and renewed immediately it shows signs of cracking. Generally speaking all the fittings used should be characterised by structural simplicity; any ornamental or decorative effects desired may be secured by proper design without sacrifice of the simplicity which should always mark the essential and operative parts of the fitting. Flexible connexions between the fixed service-pipe and a semi-portable or temporary burner may at times be required. If the connexion is for permanent use, it must not be of rubber, but of the metallic flexible tubing which is now commonly employed for such connexions in the case of coal-gas. There should be a tap between the service-pipe and the flexible connexion, and this tap should be turned off whenever the burner is out of use, so that the connexion is not at other times under the pressure which is maintained in the service-pipes. Unless the connexion is very short--say 2 feet or less--there should also be a tap at the burner. These flexible connexions, though serviceable in the case of table-lamps, &c., of which the position may have to be altered, are undesirable, as they increase the risk attendant on gas (whether acetylene or other illuminating gas) lighting, and should, if possible, be avoided. Flexible connexions may also be required for temporary use, such as for conveying acetylene to an optical lantern, and if only occasionally called for, the cost of the metallic flexible tubing will usually preclude its use. It will generally be found, however, that the whole connexion in such a case can be of composition or lead gas-piping, connected up at its two ends by a few inches of flexible rubber tubing. It should be carried along the walls or over the heads of people who may use the room, rather than across the floor, or at a low level, and the acetylene should be turned on to it only when actually required for use, and turned off at the fixed service-pipe as soon as no longer required. Quite narrow composition tubing, say 1/4-inch, will carry all the acetylene required for two or three burners. The cost of a composition temporary connexion will usually be less than one of even common rubber tubing, and it will be safer. The composition tubing must not, of course, be sharply bent, but carried by easy curves to the desired point, and it should be carefully rolled in a roll of not less than 18 inches diameter when removed. If these precautions are observed it may be used very many times. Acetylene service-pipes should, wherever possible, be laid with a fall, which may be very slight, towards a small closed vessel adjoining the gasholder or purifier, in order that any water deposited from the gas owing to condensation of aqueous vapour may run out of the pipe into that apparatus. Where it is impossible to secure an uninterrupted fall in that direction, there should be inserted in the service-pipe, at the lowest point of each dip it makes, a short length of pipe turned downwards and terminating in a plug or sound tap. Water condensing in this section of the service-pipe will then run down and collect in this drainage-pipe, from which it can be withdrawn at intervals by opening the plug or tap for a moment. The condensed water is thus removed from the service-pipe, and does not obstruct its through-way. Similar drainage devices may be used at the lowest points of all dips in mains, though there are special seal-pots which take the place of the cock or plug used to seal the end of the drainage-pipe. Such seal-pots or "syphons" are commonly used on ordinary gas-distributing systems, and might be applied in the case of large acetylene installations, as they offer facilities for removing the condensed water from time to time in a convenient and expeditious manner. EXPULSION OF AIR FROM MAINS.--After a service-pipe system has been proved to be sound, it is necessary to expel the air from it before acetylene can be admitted to it with a view to consumption. Unless the system is a very large one, the expulsion of air is most conveniently effected by forcing from the gasholder preliminary batches of acetylene through the pipes, while lights are kept away from the vicinity. This precaution is necessary because, while the acetylene is displacing the air in the pipes, they will for some time contain a mixture of air and acetylene in proportions which fall within the explosive limits of such a mixture. If the escaping acetylene caught fire from any adjacent light under these conditions, a most disastrous explosion would ensue and extend through all the ramifications of the system of pipes. Therefore the first step when a new system of pipes has to be cleared of air is to see that there are no lights in or about the house--either fires, lamps, cigars or pipes, candles or other flames. Obviously this work must be done in the daytime and finished before nightfall. Burners are removed from two or more brackets at the farthest points in the system from the gasholder, and flexible connexions are temporarily attached to them, and led through a window or door into the open air well clear of the house. One of the brackets selected should as a rule be the lowest point supplied in the house. The gasholder having been previously filled with acetylene, the tap or taps on the pipe leading to the house are turned on, and the acetylene is passed under slight pressure into the system of pipes, and escapes through the aforesaid brackets, of which the taps have been turned on, into the open. The taps of all other brackets are kept closed. The gas should be allowed to flow thus through the pipes until about five times the maximum quantity which all the burners on the system would consume in an hour has escaped from the open brackets. The taps on these brackets are then closed, and the burners replaced. Flexible tubing is then connected in place of the burners to all the other brackets in the house, and acetylene is similarly allowed to escape into the open air from each for a quarter of an hour. All taps are then closed, and the burners replaced; all windows in the house are left open wide for half an hour to allow of the dissipation of any acetylene which may have accumulated in any part of it, and then, while full pressure from the gasholder is maintained, a tap is turned on and the gas lighted. If it burns with a good, fully luminous flame it may be concluded that the system of pipes is virtually free from air, and the installation may be used forthwith as required. If, however, the flame is very feebly luminous, or if the escaping gas does not light, lights must be extinguished, and the pipes again blown through with acetylene into the open air. The burner must invariably be in position when a light is applied, because, in the event of the pipes still containing an explosive mixture, ignition would not be communicated through the small orifices of the burner to the mixture in the pipes, and the application of the light would not entail any danger of an explosion. Gasfitters familiar with coal-gas should remember, when putting a system of acetylene pipes into use for the first time, that the range over which mixtures of acetylene and air are explosive is wider than that over which mixtures of coal-gas and air are explosive, and that greater care is therefore necessary in getting the pipes and rooms free from a dangerous mixture. The mains for very large installations of acetylene--_e.g._, for lighting a small town--may advisedly be freed from air by some other plan than simple expulsion of the air by acetylene, both from the point of view of economy and of safety. If the chimney gases from a neighbouring furnace are found on examination to contain not more than about 8 per cent of oxygen, they may be drawn into the gasholder and forced through the pipes before acetylene is admitted to them. The high proportion of carbon dioxide and the low proportion of oxygen in chimney gases makes a mixture of acetylene and chimney gases non-explosive in any proportions, and hence if the air is first wholly or to a large extent expelled from a pipe, main, or apparatus, by means of chimney gases, acetylene may be admitted, and a much shorter time allowed for the expulsion by it of the contents of the pipe, before a light is applied at the burners, &c. This plan, however, will usually only be adopted in the case of very large pipes, &c.; but on a smaller scale the air may be swept out of a distributing system by bringing it into connexion with a cylinder of compressed or liquefied carbon dioxide, the pressure in which will drive the gas to any spot where an outlet is provided. As these cylinders of "carbonic acid" are in common employment for preparing aerated waters and for "lifting" beer, &c., they are easy to hire and use. TABLE (B). Giving the Sizes of Pipe which should be used in practice for Acetylene when the fall of pressure in the Pipe is not to exceed 0.1 inch. (Based on Morel's formula.) _________________________________________________________ | | | | Cubic Feet of | Diameters of Pipe to be used up to | | Acetylene | the lengths indicated. | | which the Pipe |_______________________________________| | is required to | | | | | | | pass in | 1/4 | 3/8 | 1/2 | 3/4 | 1 | | One Hour. | inch. | inch. | inch. | inch. | inch. | |________________|_______|_______|_______|_______|_______| | | | | | | | | | Feet. | Feet. | Feet. | Feet. | Feet. | | 1 | 520 | 3960 | 16700 | ... | ... | | 2 | 130 | 990 | 4170 | ... | ... | | 3 | 58 | 440 | 1850 | ... | ... | | 4 | 32 | 240 | 1040 | ... | ... | | 5 | 21 | 150 | 660 | 5070 | ... | | 6 | 14 | 110 | 460 | 3520 | ... | | 7 | 10 | 80 | 340 | 2590 | ... | | 8 | ... | 62 | 260 | 1980 | ... | | 9 | ... | 49 | 200 | 1560 | ... | | 10 | ... | 39 | 160 | 1270 | 5340 | | 15 | ... | 17 | 74 | 560 | 2370 | | 20 | ... | 10 | 41 | 310 | 1330 | | 25 | ... | ... | 26 | 200 | 850 | | 30 | ... | ... | 18 | 140 | 590 | | 35 | ... | ... | 13 | 100 | 430 | | 40 | ... | ... | 10 | 79 | 330 | | 45 | ... | ... | ... | 62 | 260 | | 50 | ... | ... | ... | 50 | 210 | |________________|_______|_______|_______|_______|_______| TABLE (A). Showing the Quantities [Q] (in cubic feet) of Acetylene which will pass in One Hour through Pipes of various diameters (in inches) under different Falls of Pressure. (Based on Morel's formula.) ____________________________________________________________________ | | | | | | | | | | | | | | Diameter | | | | | | | | | | | | | of Pipe | 1/4| 3/8| 1/2| 3/4 | 1 | 1 | 1 | 1 | 2 | 2 | 3 | | [_d_] = | | | | | | 1/4 | 1/2| 3/4| | 1/2| | | inches | | | | | | | | | | | | |__________|____|____|____|_____|_____|_____|____|____|____|____|____| | | | | Length | | | of Pipe | | | [_l_] = | Fall of Pressure in the Pipe [_h_] = 0.10 inch. | | Feet | | |__________|_________________________________________________________| | | | | | | | | | | | | | | 10 | 7.2|19.9|40.8|112 |230 |405 | 635| 935|1305|2285|3600| | 25 | 4.5|12.6|25.8| 71.2|146 |255 | 400| 590| 825|1445|2280| | 50 | 3.2| 8.9|18.3| 50.3|103 |180 | 285| 420| 585|1020|1610| | 100 | 2.3| 6.3|12.9| 35.6| 73.1|127 | 200| 295| 410| 720|1140| | 200 | 1.6| 4.4| 9.1| 25.2| 51.7| 90.3| 142| 210| 290| 510| 805| | 300 | 1.3| 3.6| 7.4| 20.5| 42.2| 73.7| 116| 171| 240| 415| 655| | 400 | 1.1| 3.1| 6.4| 17.8| 36.5| 63.8| 100| 148| 205| 360| 570| | 500 | 1.0| 2.8| 5.8| 15.9| 32.7| 57.1| 90| 132| 185| 320| 510| |__________|____|____|____|_____|_____|_____|____|____|____|____|____| | | | | Length | | | of Pipe | | | [_l_] = | Fall of Pressure in the Pipe [_h_] = 0.25 inch. | | Feet | | |__________|_________________________________________________________| | | | | | | | | | | | | | | 25 | 7.2|19.9|40.8|112 |230 |405 | 635| 935|1305|2285|3600| | 50 | 5.1|14.1|28.9| 79.6|163 |285 | 450| 660| 925|1615|2550| | 100 | 3.6| 9.9|20.4| 56.3|115 |200 | 320| 470| 655|1140|1800| | 250 | 2.3| 6.3|12.9| 35.6| 73.1|127 | 200| 295| 410| 720|1140| | 500 | 1.6| 4.4| 9.1| 25.2| 51.7| 90.3| 142| 210| 290| 510| 805| | 1000 | 1.1| 3.1| 6.4| 17.8| 36.5| 63.8| 100| 148| 205| 360| 570| |__________|____|____|____|_____|_____|_____|____|____|____|____|____| | | | | Length | | | of Pipe | | | [_l_] = | Fall of Pressure in the Pipe [_h_] = 0.50 inch. | | Feet | | |__________|_________________________________________________________| | | | | | | | | | | | | | | 25 |10.2|28.1|57.8|159 |325 |570 | 900|1325|1850|3230|5095| | 50 | 7.2|19.9|40.8|112 |230 |405 | 635| 935|1305|2285|3600| | 100 | 5.1|14.1|28.9| 79.6|163 |285 | 450| 660| 925|1615|2550| | 250 | 3.2| 8.9|18.3| 50.3|103 |180 | 285| 420| 585|1020|1610| | 500 | 2.3| 6.3|12.9| 35.6| 73.1|127 | 200| 295| 410| 720|1140| | 1000 | 1.6| 4.4| 9.1| 25.2| 51.7| 90.3| 142| 210| 290| 510| 805| |__________|____|____|____|_____|_____|_____|____|____|____|____|____| | | | | Length | | | of Pipe | | | [_l_] = | Fall of Pressure in the Pipe [_h_] = 0.75 inch. | | Feet | | |__________|_________________________________________________________| | | | | | | | | | | | | | | 50 | 8.8|24.4|50.0|138 |280 |495 | 780|1145|1160|2800|4410| | 100 | 6.2|17.2|35.4| 97.5|200 |350 | 550| 810|1130|1980|3120| | 250 | 3.9|10.9|22.4| 61.7|126 |220 | 350| 510| 715|1250|1975| | 500 | 2.8| 7.7|15.8| 43.6| 89.5|156 | 245| 360| 505| 885|1395| | 1000 | 2.0| 5.4|11.2| 30.8| 63.3|110 | 174| 255| 360| 625| 985| | 2000 | 1.4| 3.8| 7.9| 21.8| 44.8| 78.2| 123| 181| 250| 440| 695| |__________|____|____|____|_____|_____|_____|____|____|____|____|____| | | | | Length | | | of Pipe | | | [_l_] = | Fall of Pressure in the Pipe [_h_] = 1.0 inch. | | Feet | | |__________|_________________________________________________________| | | | | | | | | | | | | | | 100 | 7.2|19.9|40.8|112 |230 |405 | 635| 935|1305|2285|3600| | 250 | 4.5|12.6|25.8| 71.2|146 |255 | 400| 590| 825|1445|2280| | 500 | 3.2| 8.9|18.3| 50.3|103 |180 | 285| 420| 585|1020|1610| | 1000 | 2.3| 6.3|12.9| 35.6| 73.1|127 | 200| 295| 410| 720|1140| | 2000 | 1.6| 4.4| 9.1| 25.2| 51.7| 90.3| 142| 210| 290| 510| 805| | 3000 | 1.3| 3.6| 7.4| 20.5| 42.2| 73.7| 116| 171| 240| 415| 655| |__________|_________________________________________________________| | | | | Length | | | of Pipe | | | [_l_] = | Fall of Pressure in the Pipe [_h_] = 1.5 inch. | | Feet | | |__________|_________________________________________________________| | | | | | | | | | | | | | | 250 | 5.6|15.4|31.6| 87.2|179 |310 | 495| 725|1010|1770|2790| | 500 | 3.9|10.9|22.4| 61.7|126 |220 | 350| 510| 715|1250|1975| | 1000 | 2.8| 7.7|15.8| 43.6| 89.5|156 | 245| 360| 505| 885|1395| | 2000 | 2.0| 5.4|11.2| 30.8| 63.3|110 | 174| 255| 360| 625| 985| | 3000 | 1.6| 4.4| 9.1| 25.2| 51.7| 90.3| 142| 210| 290| 510| 805| | 4000 | 1.4| 3.8| 7.9| 21.8| 44.8| 78.2| 123| 181| 250| 440| 695| |__________|____|____|____|_____|_____|_____|____|____|____|____|____| | | | | Length | | | of Pipe | | | [_l_] = | Fall of Pressure in the Pipe [_h_] = 2.0 inches. | | Feet | | |__________|_________________________________________________________| | | | | | | | | | | | | | | 500 | 4.5|12.6|25.8| 71.2|146 |255 | 400| 590| 825|1445|2280| | 1000 | 3.2| 8.9|18.3| 50.3|103 |180 | 285| 420| 585|1020|1610| | 2000 | 2.3| 6.3|12.9| 35.6| 73.1|127 | 200| 295| 410| 720|1140| | 3000 | 1.8| 5.1|10.5| 29.1| 59.7|104 | 164| 240| 335| 590| 930| | 4000 | 1.6| 4.4| 9.1| 25.2| 51.7| 90.3| 142| 210| 290| 510| 805| | 5000 | 1.4| 4.0| 8.1| 22.5| 46.2| 80.8| 127| 187| 260| 455| 720| | 6000 | 1.3| 3.6| 7.4| 20.5| 42.2| 73.7| 116| 171| 240| 415| 655| |__________|____|____|____|_____|_____|_____|____|____|____|____|____| NOTE.--In order not to impart to the above table the appearance of the quantities having been calculated to a degree of accuracy which has no practical significance, quantities of less than 5 cubic feet have been ignored when the total quantity exceeds 200 cubic feet, and fractions of a cubic foot have been included only when the total quantity is less than 100 cubic feet. TABLE (C). Giving the Sizes of Pipe which should be used in practice for Acetylene when the fall of pressure in the Pipe is not to exceed 0.25 inch. (Based on Morel's formula.) ____________________________________________________________________ | | | | Cubic feet | | | of | | | Acetylene | Diameters of Pipe to be used up to the lengths stated.| | which the | | | Pipe is | | | required |_______________________________________________________| | to pass | | | | | | | | | | in One | 1/4 | 1/2 | 3/4 | 1 | 1-1/4| 1-1/2| 1-3/4| 2 | | Hour | inch.| inch.| inch.| inch.| inch.| inch.| inch.| inch.| |____________|______|______|______|______|______|______|______|______| | | | | | | | | | | | | Feet.| Feet.| Feet.| Feet.| Feet.| Feet.| Feet.| Feet.| | 2-1/2 | 1580 | 6680 | 50750| ... | ... | ... | ... | ... | | 5 | 390 | 1670 | 12690| 53160| ... | ... | ... | ... | | 7-1/2 | 175 | 710 | 5610| 23760| ... | ... | ... | ... | | 10 | 99 | 410 | 3170| 13360| 40790| ... | ... | ... | | 15 | 41 | 185 | 1410| 5940| 18130| 45110| ... | ... | | 20 | 24 | 105 | 790| 3350| 10190| 25370| 54840| ... | | 25 | 26 | 67 | 500| 2130| 6520| 16240| 35100| ... | | 30 | 11 | 46 | 350| 1480| 4530| 11270| 24370| 47520| | 35 | ... | 34 | 260| 1090| 3330| 8280| 17900| 34910| | 40 | ... | 26 | 195| 830| 2550| 6340| 13710| 26730| | 45 | ... | 20 | 155| 660| 2010| 5010| 10830| 21120| | 50 | ... | 16 | 125| 530| 1630| 4060| 8770| 17110| | 60 | ... | 11 | 88| 370| 1130| 2880| 6090| 11880| | 70 | ... | ... | 61| 270| 830| 2070| 4470| 8730| | 80 | ... | ... | 49| 210| 630| 1580| 3420| 6680| | 90 | ... | ... | 39| 165| 500| 1250| 2700| 5280| | 100 | ... | ... | 31| 130| 400| 1010| 2190| 4270| | 150 | ... | ... | 14| 59| 180| 450| 970| 1900| | 200 | ... | ... | ... | 33| 100| 250| 540| 1070| | 250 | ... | ... | ... | 21| 65| 160| 350| 680| | 500 | ... | ... | ... | ... | 16| 40| 87| 170| | 1000 | ... | ... | ... | ... | ... | 10| 22| 42| |____________|______|______|______|______|______|______|______|______| TABLE (D). Giving the Sizes of Pipe which should be used in practice for Acetylene Mains when the fall of pressure in the Main is not to exceed 0.5 inch, (Based on Morel's formula.) ____________________________________________________________________ | | | | Cubic feet | | | of | | | Acetylene | Diameters of Pipe to be used up to the lengths stated.| | which the | | | Main is | | | required |_______________________________________________________| | to pass | | | | | | | | | | in One | 3/4 | 1 | 1-1/4| 1-1/2| 1-3/4| 2 | 2-1/2| 3 | | Hour | inch.| inch.| inch.| inch.| inch.| inch.| inch.| inch.| |____________|______|______|______|______|______|______|______|______| | | | | | | | | | | | |Miles.|Miles.|Miles.|Miles.|Miles.|Miles.|Miles.|Miles.| | 10 | 5.05 | ... | ... | ... | ... | ... | ... | ... | | 25 | 0.80 | 2.45 | 6.15 | ... | ... | ... | ... | ... | | 50 | 0.20 | 0.60 | 1.50 | 3.30 | 6.45 | ... | ... | ... | | 100 | 0.05 | 0.15 | 0.35 | 0.80 | 1.60 | 4.95 |12.30 | ... | | 200 | ... | 0.04 | 0.09 | 0.20 | 0.40 | 1.20 | 3.05 |12.95 | | 300 | ... | ... | 0.04 | 0.09 | 0.18 | 0.55 | 1.35 | 5.75 | | 400 | ... | ... | ... | 0.05 | 0.10 | 0.30 | 0.75 | 3.25 | | 500 | ... | .. | ... | 0.03 | 0.06 | 0.20 | 0.50 | 2.05 | | 750 | ... | ... | ... | ... | 0.03 | 0.08 | 0.20 | 0.80 | | 1100 | ... | ... | ... | ... | ... | 0.05 | 0.12 | 0.50 | | 1500 | ... | ... | ... | ... | ... | 0.02 | 0.05 | 0.23 | | 2000 | ... | ... | ... | ... | ... | ... | 0.03 | 0.13 | | 2500 | ... | ... | ... | ... | ... | ... | 0.02 | 0.08 | | 5000 | ... | ... | ... | ... | ... | ... | ... | 0.03 | |____________|______|______|______|______|______|______|______|______| TABLE (E). Giving the Sizes of Pipe which should be used in practice for Acetylene Mains when the fall of pressure in the Main is not to exceed 1.0 inch. (Based on Morel's formula.) __________________________________________________________________ | | | | Cubic feet | | | of | | | Acetylene |Diameters of Pipe to be used up to the lengths stated| | which the | | | Main is | | | required |_____________________________________________________| | to pass | | | | | | | | | | | in One | 3/4 | 1 |1-1/4|1-1/2|1-3/4| 2 |2-1/2| 3 | 4 | | Hour |inch.|inch.|inch.|inch.|inch.|inch.|inch.|inch.|inch.| |____________|_____|_____|_____|_____|_____|_____|_____|_____|_____| | | | | | | | | | | | | |Miles|Miles|Miles|Mile.|Miles|Miles|Miles|Miles|Miles| | 10 | 2.40|10.13|30.90| ... | ... | ... | ... | ... | ... | | 25 | 0.38| 1.62| 4.94|12.30| ... | ... | ... | ... | ... | | 50 | 0.09| 0.40| 1.23| 3.07| 6.65|12.96| ... | ... | ... | | 100 | 0.02| 0.10| 0.30| 0.77| 1.66| 3.24| 9.88| ... | ... | | 200 | ... | 0.02| 0.07| 0.19| 0.41| 0.81| 2.47| 6.15| ... | | 300 | ... | 0.01| 0.03| 0.08| 0.18| 0.36| 1.09| 2.73|11.52| | 400 | ... | ... | 0.0 | 0.05| 0.10| 0.20| 0.61| 1.53| 6.48| | 500 | ... | ... | 0.0 | 0.03| 0.06| 0.13| 0.39| 0.98| 4.14| | 750 | ... | ... | ... | 0.01| 0.03| 0.05| 0.17| 0.43| 1.84| | 1000 | ... | ... | ... | ... | 0.01| 0.03| 0.10| 0.24| 1.03| | 1500 | ... | ... | ... | ... | ... | 0.01| 0.01| 0.11| 0.46| | 2000 | ... | ... | ... | ... | ... | ... | 0.02| 0.06| 0.26| | 2500 | ... | ... | ... | ... | ... | ... | 0.01| 0.04| 0.16| | 5000 | ... | ... | ... | ... | ... | ... | ... | 0.01| 0.04| |____________|_____|_____|_____|_____|_____|_____|_____|_____|_____| CHAPTER VIII COMBUSTION OF ACETYLENE IN LUMINOUS BURNERS--THEIR DISPOSITION NATURE OF LUMINOUS FLAMES.--When referring to methods of obtaining artificial light by means of processes involving combustion or oxidation, the term "incandescence" is usually limited to those forms of burner in which some extraneous substance, such as a "mantle," is raised to a brilliant white heat. Though convenient, the phrase is a mere convention, for all artificial illuminants, even including the electric light, which exhibit a useful degree of intensity depend on the same principle of incandescence. Adopting the convention, however, an incandescent burner is one in which the fuel burns with a non-luminous or atmospheric flame, the light being produced by causing that flame to play upon some extraneous refractory body having the property of emitting much light when it is raised to a sufficiently high temperature; while a luminous burner is one in which the fuel is allowed to combine with atmospheric oxygen in such a way that one or more of the constituents in the gas evolves light as it suffers combustion. From the strictly chemical point of view the light-giving substance in the incandescent flame lasts indefinitely, for it experiences no change except in temperature; whereas the light-giving substance in a luminous flame lasts but for an instant, for it only evolves light during the act of its combination with the oxygen of the atmosphere. Any fluid combustible which burns with a flame can be made to give light on the incandescent system, for all such materials either burn naturally, or can be made to burn with a non- luminous flame, which can be employed to raise the temperature of some mantle; but only those fuels can be burnt on the self-luminous system which contain some ingredient that is liberated in the elemental state in the flame, the said ingredient being one which combines energetically with oxygen so as to liberate much local heat. In practice, just as there are only two or three substances which are suitable for the construction of an incandescent mantle, so there is only one which renders a flame usefully self-luminous, viz., carbon; and therefore only such fuels as contain carbon among their constituents can be burnt so as to produce light without the assistance of the mantle. But inasmuch as it is necessary for the evolution of light by the combustion of carbon that that carbon shall be in the free state, only those carbonaceous fuels yield light without the mantle in which the carbonaceous ingredient is dissociated into its elements before it is consumed. For instance, alcohol and carbon monoxide are both combustible, and both contain carbon; but they yield non-luminous flames, for the carbon burns to carbon dioxide in ordinary conditions without assuming the solid form; ether, petroleum, acetylene, and some of the hydrocarbons of coal-gas do emit light on combustion, for part of their carbon is so liberated. The quantity of light emitted by the glowing substance increases as the temperature of that substance rises: the gain in light being equal to the fifth or higher power of the gain in heat; [Footnote: Calculated from absolute zero.] therefore unnecessary dissipation of heat from a flame is one of the most important matters to be guarded against if that flame is to be an economical illuminant. But the amount of heat liberated when a certain weight (or volume) of a particular fuel combines with a sufficient quantity of oxygen to oxidise it wholly is absolutely fixed, and is exactly the same whether that fuel is made to give a luminous or a non-luminous flame. Nevertheless the atmospheric flame given by a certain fuel may be appreciably hotter than its luminous flame, because the former is usually smaller than the latter. Unless the luminous flame of a rich fuel is made to expose a wide surface to the air, part of its carbon may escape ultimate combustion; soot or smoke may be produced, and some of the most valuable heat-giving substance will be wasted. But if the flame is made to expose a large surface to the air, it becomes flat or hollow in shape instead of being cylindrical and solid, and therefore in proportion to its cubical capacity it presents to the cold air a larger superficies, from which loss of heat by radiation, &c., occurs. Being larger, too, the heat produced is less concentrated. It does not fall within the province of the present book to discuss the relative merits of luminous and incandescent lighting; but it may be remarked that acetylene ranks with petroleum against coal-gas, carburetted or non-carburetted water-gas, and semi-water-gas, in showing a comparatively small degree of increased efficiency when burnt under the mantle. Any gas which is essentially composed of carbon monoxide or hydrogen alone (or both together) burns with a non-luminous flame, and can therefore only be used for illuminating purposes on the incandescent system; but, broadly speaking, the higher is the latent illuminating power of the gas itself when burnt in a non-atmospheric burner, the less marked is the superiority, both from the economical and the hygienic aspect, of its incandescent flame. It must be remembered also that only a gas yields a flame when it is burnt; the flame of a paraffin lamp and of a candle is due to the combustion of the vaporised fuel. Methods of burning acetylene under the mantle are discussed in Chapter IX.; here only self-luminous flames are being considered, but the theoretical question of heat economy applies to both processes. Heat may be lost from a flame in three several ways: by direct radiation and conduction into the surrounding air, among the products of combustion, and by conduction into the body of the burner. Loss of heat by radiation and conduction to the air will be the greater as the flame exposes a larger surface, and as a more rapid current of cold air is brought into proximity with the flame. Loss of heat by conduction, into the burner will be the greater as the material of which the burner is constructed is a better conductor of heat, and as the mass of material in that burner is larger. Loss of heat by passage into the combustion products will also be greater as these products are more voluminous; but the volume of true combustion products from any particular gas is a fixed quantity, and since these products must leave the flame at the temperature of that flame--where the highest temperature possible is requisite--it would seem that no control can be had over the quantity of heat so lost. However, although it is not possible in practice to supply a flame with too little air, lest some of its carbon should escape consumption and prove a nuisance, it is very easy without conspicuous inconvenience to supply it with too much; and if the flame is supplied with too much, there is an unnecessary volume of air passing through it to dilute the true combustion products, which air absorbs its own proper proportion of heat. It is only the oxygen of the air which a flame needs, and this oxygen is mixed with approximately four times its volume of nitrogen; if, then, only a small excess of oxygen (too little to be noticeable of itself) is admitted to a flame, it is yet harmful, because it brings with it four times its volume of nitrogen, which has to be raised to the same temperature as the oxygen. Moreover, the nitrogen and the excess of oxygen occupy much space in the flame, making it larger, and distributing that fixed quantity of heat which it is capable of generating over an unnecessarily large area. It is for this reason that any gas gives so much brighter a light when burnt in pure oxygen than in air, (1) because the flame is smaller and its heat more concentrated, and (2) because part of its heat is not being wasted in raising the temperature of a large mass of inert nitrogen. Thus, if the flame of a gas which naturally gives a luminous flame is supplied with an excess of air, its illuminating value diminishes; and this is true whether that excess is introduced at the base of the actual flame, or is added to the gas prior to ignition. In fact the method of adding some air to a naturally luminous gas before it arrives at its place of combustion is the principle of the Bunsen burner, used for incandescent lighting and for most forms of warming and cooking stoves. A well-made modern atmospheric burner, however, does not add an excess of air to the flame, as might appear from what has been said; such a burner only adds part of the air before and the remainder of the necessary quantity after the point of first ignition--the function of the primary supply being merely to insure thorough admixture and to avoid the production of elemental carbon within the flame. ILLUMINATING POWER.--It is very necessary to observe that, as the combined losses of heat from a flame must be smaller in proportion to the total heat produced by the flame as the flame itself becomes larger, the more powerful and intense any single unit of artificial light is, the more economical does it become, because economy of heat spells economy of light. Conversely, the more powerful and intense any single unit of light is, the more is it liable to injure the eyesight, the deeper and, by contrast, the more impenetrable are the shadows it yields, and the less pleasant and artistic is its effect in an occupied room. For economical reasons, therefore, one large central source of light is best in an apartment, but for physiological and æsthetic reasons a considerable number of correspondingly smaller units are preferable. Even in the street the economical advantage of the single unit is outweighed by the inconvenience of its shadows, and by the superiority of a number of evenly distributed small sources to one central large source of light whenever the natural transmission of light rays through the atmosphere is interfered with by mist or fog. The illuminating power of acetylene is commonly stated to be "240 candles" (though on the same basis Wolff has found it to be about 280 candles). This statement means that when acetylene is consumed in the most advantageous self-luminous burner at the most advantageous rate, that rate (expressed in cubic feet per hour) is to 5 in the same ratio as the intensity of the light evolved (expressed in standard candles) is to the said "illuminating power." Thus, Wolff found that when acetylene was burnt in the "0000 Bray" fish- tail burner at the rate of 1.377 cubic feet per hour, a light of 77 candle-power was obtained. Hence, putting x to represent the illuminating power of the acetylene in standard candles, we have: 1.377 / 5 = 77 / x hence x = 280. Therefore acetylene is said to have, according to Wolff, an illuminating power of about 280 candles, or according to other observers, whose results have been commonly quoted, of 240 candles. The same method of calculating the nominal illuminating power of a gas is applied within the United Kingdom in the case of all gases which cannot be advantageously burnt at the rate of 5 cubic feet per hour in the standard burner (usually an Argand). The rate of 5 cubic feet per hour is specified in most Acts of Parliament relating to gas-supply as that at which coal-gas is to be burnt in testings of its illuminating power; and the illuminating power of the gas is defined as the intensity, expressed in standard candles, of the light afforded when the gas is burnt at that rate. In order to make the values found for the light evolved at more advantageous rates of consumption by other descriptions of gas--such as oil-gas or acetylene--comparable with the "illuminating power" of coal- gas as defined above, the values found are corrected in the ratio of the actual rate of consumption to 5 cubic feet per hour. In this way the illuminating power of 240 candles has been commonly assigned to acetylene, though it would be clearer to those unfamiliar with the definition of illuminating power in the Acts of Parliament which regulate the testing of coal-gas, if the same fact were conveyed by stating that acetylene affords a maximum illuminating power of 48 candles (_i.e._, 240 / 5) per cubic foot. Actually, by misunderstanding of the accepted though arbitrary nomenclature of gas photometry, it has not infrequently been assorted or implied that a cubic foot of acetylene yields a light of 240 candle-power instead of 48 candle-power. It should, moreover, be remembered that the ideal illuminating power of a gas is the highest realisable in any Argand or flat-flame burner, while the said burner may not be a practicable one for general use in house lighting. Thus, the burners recommended for general use in lighting by acetylene do not develop a light of 48 candles per cubic foot of gas consumed, but considerably less, as will appear from the data given later in this chapter. It has been stated that in order to avoid loss of heat from a flame through the burner, that burner should present only a small mass of material (_i.e._, be as light in weight as possible), and should be constructed of a bad heat-conductor. But if a small mass of a material very deficient in heat-conducting properties comes in contact with a flame, its temperature rises seriously and may approach that of the base of the flame itself. In the case of coal-gas this phenomenon is not objectionable, is even advantageous, and it explains why a burner made of steatite, which conducts heat badly, in always more economical (of heat and therefore of light) than an iron one. In the case of acetylene the same rule should, and undoubtedly does, apply also; but it is complicated, and its effect sometimes neutralised, by a peculiarity of the gas itself. It has been shown in Chapters II. and VI. that acetylene polymerises under the influence of heat, being converted into other bodies of lower illuminating power, together with some elemental carbon. If, now, acetylene is fed into a burner which, being composed of some material like steatite possessed of low heat-conducting and radiating powers, is very hot, and if the burner comprises a tube of sensible length, the gas that actually arrives at the orifice may no longer be pure acetylene, but acetylene diluted with inferior illuminating agents, and accompanied by a certain proportion of carbon. Neglecting the effect of this carbon, which will be considered in the following paragraph, it is manifest that the acetylene issuing from a hot burner--assuming its temperature to exceed the minimum capable of determining polymerisation-- may emit less light per unit of volume than the acetylene escaping from a cold burner. Proof of this statement is to be found in some experiments described by Bullier, who observed that when a small "Manchester" or fish-tail burner was allowed to become naturally hot, the quantity of gas needed to give the light of one candle (uncorrected) was 1.32 litres, but when the burner was kept cool by providing it with a jacket in which water was constantly circulating, only 1.13 litres of acetylene were necessary to obtain the same illuminating value, this being an economy of 16 per cent. EARLY BURNERS.--One of the chief difficulties encountered in the early days of the acetylene industry was the design of a satisfactory burner which should possess a life of reasonable length. The first burners tried were ordinary oil-gas jets, which resemble the fish-tails used with coal- gas, but made smaller in every part to allow for the higher illuminating power of the oil-gas or acetylene per unit of volume. Although the flames they gave were very brilliant, and indeed have never been surpassed, the light quickly fell off in intensity owing to the distortion of their orifices caused by the deposition of solid matter at the edges. Various explanations have been offered to account for the precipitation of solid matter at the jets. If the acetylene passes directly to the burner from a generator having carbide in excess without being washed or filtered in any way, the gas may carry with it particles of lime dust, which will collect in the pipes mainly at the points where they are constricted; and as the pipes will be of comparatively large bore until the actual burner is readied, it will be chiefly at the orifices where the deposition occurs. This cause, though trivial, is often overlooked. It will be obviated whenever the plant is intelligently designed. As the phosphoric anhydride, or pentoxide, which is produced when a gas containing phosphorus burns, is a solid body, it may be deposited at the burner jets. This cause may be removed, or at least minimised, by proper purification of the acetylene, which means the removal of phosphorus compounds. Should the gas contain hydrogen silicide siliciuretted hydrogen), solid silica will be produced similarly, and will play its part in causing obstruction. According to Lewes the main factor in the blocking of the burners is the presence of liquid polymerised products in the acetylene, benzene in particular; for he considers that these bodies will be absorbed by the porous steatite, and will be decomposed under the influence of heat in that substance, saturating the steatite with carbon which, by a "catalytic" action presumably, assists in the deposition of further quantities of carbon in the burner tube until distortion of the flame results. Some action of this character possibly occurs; but were it the sole cause of blockage, the trouble would disappear entirely if the gas were washed with some suitable heavy oil before entering the burners, or if the latter were constructed of a non-porous material. It is certainly true that the purer is the acetylene burnt, both as regards freedom from phosphorus and absence of products of polymerisation, the longer do the burners last; and it has been claimed that a burner constructed at its jets of some non-porous substance, e.g., "ruby," does not choke as quickly as do steatite ones. Nevertheless, stoppages at the burners cannot be wholly avoided by these refinements. Gaud has shown that when pure acetylene is burnt at the normal rate in 1-foot Bray jets, growths of carbon soon appear, but do not obstruct the orifices during 100 hours' use; if, however, the gas-supply is checked till the flame becomes thick, the growths appear more quickly, and become obstructive after some 60 hours' burning. On the assumption that acetylene begins to polymerise at a temperature of 100° C., Gaud calculates that polymerisation cannot cause blocking of the burners unless the speed of the passing gas is so far reduced that the burner is only delivering one- sixth of its proper volume. But during 1902 Javal demonstrated that on heating in a gas-flame one arm of a twin, non-injector burner which had been and still was behaving quite satisfactorily with highly purified acetylene, growths were formed at the jet of that arm almost instantaneously. There is thus little doubt that the principal cause of this phenomenon is the partial dissociation of the acetylene (i.e., decomposition into its elements) as it passes through the burner itself; and the extent of such dissociation will depend, not at all upon the purity of the gas, but upon the temperature of the burner, upon the readiness with which the heat of the burner is communicated to the gas, and upon the speed at which the acetylene travels through the burner. Some experiments reported by R. Granjon and P. Mauricheau-Beaupré in 1906 indicate, however, that phosphine in the gas is the primary cause of the growths upon non-injector burners. According to these investigators the combustion of the phosphine causes a deposit at the burner orifices of phosphoric acid, which is raised by the flame to a temperature higher than that of the burner. This hot deposit then decomposes some acetylene, and the carbon deposited therefrom is rendered incombustible by the phosphoric acid which continues to be produced from the combustion of the phosphine in the gas. The incombustible deposit of carbon and phosphoric acid thus produced ultimately chokes the burner. It will appear in Chapter XI. that some of the first endeavours to avoid burner troubles were based on the dilution of the acetylene with carbon dioxide or air before the gas reached the place of combustion; while the subsequent paragraphs will show that the same result is arrived at more satisfactorily by diluting the acetylene with air during its actual passage through the burner. It seems highly probable that the beneficial effect of the earliest methods was due simply or primarily to the dilution, the molecules of the acetylene being partially protected from the heat of the burner by the molecules of a gas which was not injured by the high temperature, and which attracted to itself part of the heat that would otherwise have been communicated to the hydrocarbon. The modern injector burner exhibits the same phenomenon of dilution, and is to the same extent efficacious in preventing polymerisation; but inasmuch as it permits a larger proportion of air to be introduced, and as the addition is made roughly half-way along the burner passage, the cold air is more effectual in keeping the former part of the tip cool, and in jacketing the acetylene during its travel through the latter part, the bore of which is larger than it otherwise would be. INJECTOR AND TWIN-FLAME BURNERS.--In practice it is neither possible to cool an acetylene burner systematically, nor is it desirable to construct it of such a large mass of some good heat conductor that its temperature always remains below the dissociation point of the gas. The earliest direct attempts to keep the burner cool were directed to an avoidance of contact between the flame of the burning acetylene and the body of the jet, this being effected by causing the current of acetylene to inject a small proportion of air through lateral apertures in the burner below the point of ignition. Such air naturally carries along with it some of the heat which, in spite of all precautions, still reaches the burner; but it also apparently forms a temporary annular jacket round the stream of gas, preventing it from catching fire until it has arrived at an appreciable distance from the jet. Other attempts were made by placing two non- injector jets in such mutual positions that the two streams of gas met at an angle, there to spread fan-fashion into a flat flame. This is really nothing but the old fish-tail coal-gas burner--which yields its flat flame by identical impingement of two gas streams--modified in detail so that the bulk of the flame should be at a considerable distance from the burner instead of resting directly upon it. In the fish-tail the two orifices are bored in the one piece of steatite, and virtually join at their external ends; in the acetylene burner, two separate pieces of steatite, three-quarters of an inch or more apart, carried by completely separate supports, are each drilled with one hole, and the flame stands vertically midway between them. The two streams of gas are in one vertical plane, to which the vertical plane of the flame is at right angles. Neither of these devices singly gave a solution of the difficulty; but by combining the two--the injector and the twin-flame principle--the modern flat-flame acetylene burner has been evolved, and is now met with in two slightly different forms known as the Billwiller and the Naphey respectively. The latter apparently ought to be called the Dolan. [Illustration: FIG. 8.--TYPICAL ACETYLENE BURNERS.] The essential feature of the Naphey burner is the tip, which is shown in longitudinal section at A in Fig. 8. It consists of a mushroom headed cylinder of steatite, drilled centrally with a gas passage, which at its point is of a diameter suited to pass half the quantity of acetylene that the entire burner is intended to consume. The cap is provided with four radial air passages, only two of which are represented in the drawing; these unite in the centre of the head, where they enter into the longitudinal channel, virtually a continuation of the gas-way, leading to the point of combustion by a tube wide enough to pass the introduced air as well as the gas. Being under some pressure, the acetylene issuing from the jet at the end of the cylindrical portion of the tip injects air through the four air passages, and the mixture is finally burnt at the top orifice. As pointed out in Chapter VII., the injector jet is so small in diameter that even if the service-pipes leading to the tip contain an explosive mixture of acetylene and air, the explosion produced locally if a light is applied to the burner cannot pass backwards through that jet, and all danger is obviated. One tip only of this description evidently produces a long, jet-like flame, or a "rat-tail," in which the latent illuminating power of the acetylene is not developed economically. In practice, therefore, two of these tips are employed in unison, one of the commonest methods of holding them being shown at B. From each tip issues a stream of acetylene mixed with air, and to some extent also surrounded by a jacket of air; and at a certain point, which forms the apex of an isosceles right-angled triangle having its other angles at the orifices of the tips, the gas streams impinge, yielding a flat flame, at right- angles, as mentioned before, to the plane of the triangle. If the two tips are three-quarters of an inch apart, and if the angle of impingement is exactly 90°, the distance of each tip from the base of the flame proper will be a trifle over half an inch; and although each stream of gas does take fire and burn somewhat before meeting its neighbour, comparatively little heat is generated near the body of the steatite. Nevertheless, sufficient heat is occasionally communicated to the metal stems of these burners to cause warping, followed by a want of alignment in the gas streams, and this produces distortion of the flame, and possibly smoking. Three methods of overcoming this defect have been used: in one the arms are constructed entirely of steatite, in another they are made of such soft metal as easily to be bent back again into position with the fingers or pliers, in the third each arm is in two portions, screwing the one into the other. The second type is represented by the original Phôs burner, in which the curved arms of B are replaced by a pair of straight divergent arms of thin, soft tubing, joined to a pair of convergent wider tubes carrying the two tips. The third type is met with in the Drake burner, where the divergent arms are wide and have an internal thread into which screws an external thread cut upon lateral prolongations of the convergent tubes. Thus both the Phôs and the Drake burner exhibit a pair of exposed elbows between the gas inlet and the two tips; and these elbows are utilised to carry a screwed wire fastened to an external milled head by means of which any deposit of carbon in the burner tubes can be pushed out. The present pattern of the Phôs burner is shown in Fig. 9, in which _A_ is the burner tip, _B_ the wire or needle, and _C_ the milled head by which the wire is screwed in and out of the burner tube. [Illustration: FIG. 9.--IMPROVED PHÔS BURNER.] [Illustration: FIG. 10.--"WONDER" SINGLE AND TWO-FLAME BURNERS.] [Illustration: FIG. 11.--"SUPREMA" NO. 266651, TWO-FLAME BURNER.] [Illustration: FIG. 12.--BRAY'S MODIFIED NAPHEY INJECTOR BURNER TIP.] [Illustration: FIG. 13.--BRAY'S "ELTA" BURNER.] [Illustration: FIG. 14.--BRAY'S "LUTA" BURNER.] [Illustration: FIG. 15.--BRAY'S "SANSAIR" BURNER.] [Illustration: FIG. 16.--ADJUSTABLE "KONA" BURNER.] In the original Billwiller burner, the injector gas orifice was brought centrally under a somewhat larger hole drilled in a separate sheet of platinum, the metal being so carried as to permit entry of air. In order to avoid the expense of the platinum, the same principle was afterwards used in the design of an all-steatite head, which is represented at D in Fig. 8. The two holes there visible are the orifices for the emission of the mixture of acetylene with indrawn air, the proper acetylene jets lying concentrically below these in the thicker portions of the heads. These two types of burner have been modified in a large number of ways, some of which are shown at C, E, and F; the air entering through saw- cuts, lateral holes, or an annular channel. Burners resembling F in outward form are made with a pair of injector jets and corresponding air orifices on each head, so as to produce a pair of names lying in the same plane, "end-on" to one another, and projecting at either side considerably beyond the body of the burner; these have the advantage of yielding no shadow directly underneath. A burner of this pattern, viz., the "Wonder," which is sold in this country by Hannam's, Ltd., is shown in Fig. 10, alongside the single-flame "Wonder" burner, which is largely used, especially in the United States. Another two-flame burner, made of steatite, by J. von Schwarz of Nuremberg, and sold by L. Wiener of London, is shown in Fig. 11. Burners of the Argand type have also been manufactured, but have been unsuccessful. There are, of course, endless modifications of flat-flame burners to be found on the markets, but only a few need be described. A device, which should prove useful where it may be convenient to be able to turn one or more burners up or down from the same common distant spot, has been patented by Forbes. It consists of the usual twin-injector burner fitted with a small central pinhole jet; and inside the casing is a receptacle containing a little mercury, the level of which is moved by the gas pressure by an adaptation of the displacement principle. When the main is carrying full pressure, both of the jets proper are alight, and the burner behaves normally, but if the pressure is reduced to a certain point, the movement of the mercury seals the tubes leading to the main jets, and opens that of the pilot flame, which alone remains alight till the pressure is increased again. Bray has patented a modification of the Naphey injector tip, which is shown in Fig. 12. It will be observed that the four air inlets are at right-angles to the gas-way; but the essential feature of the device is the conical orifice. By this arrangement it is claimed that firing back never occurs, and that the burner can be turned down and left to give a small flame for considerable periods of time without fear of the apertures becoming choked or distorted. As a rule burners of the ordinary type do not well bear being turned down; they should either be run at full power or extinguished completely. The "Elta" burner, made by Geo. Bray and Co., Ltd., which is shown in Fig. 13, is an injector or atmospheric burner which may be turned low without any deposition of carbon occurring on the tips. A burner of simple construction but which cannot be turned low is the "Luta," made by the same firm and shown in Fig. 14. Of the non- atmospheric type the "Sansair," also made by Geo. Bray and Co., Ltd., is extensively used. It is shown in Fig. 15. In order to avoid the warping, through the heat of the flame, of the arms of burners which sometimes occurs when they are made of metal, a number of burners are now made with the arms wholly of steatite. One of the best-known of these, of the injector type, is the "Kona," made by Falk, Stadelmann and Co., of London. It is shown in Fig. 16, fitted with a screw device for adjusting the flow of gas, so that when this adjuster has been set to give a flame of the proper size, no further adjustment by means of the gas-tap is necessary. This saves the trouble of manipulating the tap after the gas is lighted. The same adjusting device may also be had fitted to the Phôs burner (Fig. 9) or to the "Orka" burner (Fig. 17), which is a steatite- tip injector burner with metal arms made by Falk, Stadelmann and Co., Ltd. A burner with steatite arms, made by J. von Schwarz of Nuremberg, and sold in this country by L. Wiener of London, is shown in Fig. 18. [Illustration: FIG. 17.--"ORKA" BURNER.] [Illustration: FIG. 18.--"SUPREMA" NO. 216469 BURNER.] ILLUMINATING DUTY.--The illuminating value of ordinary self-luminous acetylene burners in different sizes has been examined by various photometrists. For burners of the Naphey type Lewes gives the following table: ___________________________________________________________ | | | | | | | | | Gas | | Candles | | Burner. | Pressure, | Consumed, | Light in | per | | | Inches | Cubic Feet | Candles. | Cubic Foot. | | | | per Hour. | | | |_________|___________|____________|__________|_____________| | | | | | | | No. 6 | 2.0 | 0.155 | 0.794 | 5.3 | | " 8 | 2.0 | 0.27 | 3.2 | 11.6 | | " 15 | 2.0 | 0.40 | 8.0 | 20.0 | | " 25 | 2.0 | 0.65 | 17.0 | 26.6 | | " 30 | 2.0 | 0.70 | 23.0 | 32.85 | | " 42 | 2.0 | 1.00 | 34.0 | 34.0 | |_________|___________|____________|__________|_____________| From burners of the Billwiller type Lewes obtained in 1899 the values: ___________________________________________________________ | | | | | | | | | Gas | | Candles | | Burner. | Pressure, | Consumed, | Light in | per | | | Inches | Cubic Feet | Candles. | Cubic Foot. | | | | per Hour. | | | |_________|___________|____________|__________|_____________| | | | | | | | No. 1 | 2.0 | 0.5 | 7.0 | 11.0 | | " 2 | 2.0 | 0.75 | 21.0 | 32.0 | | " 3 | 2.0 | 0.75 | 28.0 | 37.3 | | " 4 | 3.0 | 1.2 | 48.0 | 40.0 | | " 5 | 3.5 | 2.0 | 76.0 | 38.0 | |_________|___________|____________|__________|_____________| Neuberg gives these figures for different burners (1900) as supplied by Pintsch: ______________________________________________________________________ | | | | | | | | Gas | | Candles | |"w | Burner. | Pressure, | Consumed, | Light in | per | | | Inches | Cubic Feet | Candles. | Cubic Foot. | | | | per Hour. | | | |____________________|___________|____________|__________|_____________| | | | | | | | No. 0, slit burner | 3.9 | 1.59 | 59.2 | 37.3 | | " 00000 fishtail | 1.6 | 0.81 | 31.2 | 38.5 | | Twin burner No. 1 | 3.2 | 0.32 | 13.1 | 40.8 | | " " " 2 | 3.2 | 0.53 | 21.9 | 41.3 | | " " " 3 | 3.2 | 0.74 | 31.0 | 41.9 | | " " " 4 | 3.2 | 0.95 | 39.8 | 41.9 | |____________________|___________|____________|__________|_____________| The actual candle-power developed by each burner was not quoted by Neuberg, and has accordingly been calculated from his efficiency values. It is noteworthy, and in opposition to what has been found by other investigators as well as to strict theory, that Neuberg represents the efficiencies to be almost identical in all sizes of the same description of burner, irrespective of the rate at which it consumes gas. Writing in 1902, Capelle gave for Stadelmann's twin injector burners the following figures; but as he examined each burner at several different pressures, the values recorded in the second, third, and fourth columns are maxima, showing the highest candle-power which could be procured from each burner when the pressure was adjusted so as to cause consumption to proceed at the most economical rate. The efficiency values in the fifth column, however, are the mean values calculated so as to include all the data referring to each burner. Capelle's results have been reproduced from the original on the basis that 1 _bougie décimale_ equals 0.98 standard English candle, which is the value he himself ascribes to it (1 _bougie décimale_ equals 1.02 candles is the value now accepted). _____________________________________________________________________ | | | | | | | Nominal | Best | Actual Consumption | Maximum | Average | | Consumption,| Pressure| at Stated Pressure. | Light in | Candles per| | Litres. | Inches. | Cubic Feet per Hour.| Candles. | Cubic Foot.| |_____________|_________|_____________________|__________|____________| | | | | | | | 10 | 3.5 | 0.40 | 8.4 | 21.1 | | 15 | 2.8 | 0.46 | 16.6 | 33.3 | | 20 | 3.9 | 0.64 | 25.1 | 40.0 | | 25 | 3.5 | 0.84 | 37.8 | 46.1 | | 30 | 3.5 | 0.97 | 48.2 | 49.4 | |_____________|_________|_____________________|__________|____________| Some testings of various self-luminous burners of which the results were reported by R. Granjon in 1907, gave the following results for the duty of each burner, when the pressure was regulated for each burner to that which afforded the maximum illuminating duty. The duty in the original paper is given in litres per Carcel-hour. The candle has been taken as equal to 0.102 Carcel for the conversion to candles per cubic foot. ___________________________________________________________________ | | | | | | | Nominal | Best | Duty. Candles | | Burner. | Consumption.| Pressure. | per cubic foot. | |_______________________|_____________|__________ |_________________| | | | | | | | Litres. | Inches. | | | Twin . . . . | 10 | 2.76 | 21.2 | | " . . . . | 20 | 2.76 | 23.5 | | " . . . . | 25 | 3.94 | 30.2 | | " . . . . | 30 | 3.94-4.33 | 44.8 | | ", (pair of flames) | 35 | 3.55-3.94 | 45.6 | | Bray's "Manchester" | 6 | 1.97 | 18.8 | | " | 20 | 1.97 | 35.6 | | " | 40 | 2.36 | 42.1 | | Rat-tail . . . | 5 | 5.5 | 21.9 | | " . . . | 8 | 4.73 | 25.0 | | Slit or batswing . | 30 | 1.97-2.36 | 37.0 | |_______________________|_____________|___________|_________________| Granjon has concluded from his investigations that the Manchester or fish-tail burners are economical when they consume 0.7 cubic foot per hour and when the pressure is between 2 and 2.4 inches. When these burners are used at the pressure most suitable for twin burners their consumption is about one-third greater than that of the latter per candle-hour. The 25 to 35 litres-per-hour twin burners should be used at a pressure higher by about 1 inch than the 10 to 20 litres-per-hour twin burners. At the present time, when the average burner has a smaller hourly consumption than 1 foot per hour, it is customary in Germany to quote the mean illuminating value of acetylene in self-luminous burners as being 1 Hefner unit per 0.70 litre, which, taking 1 Hefner unit = 0.913 English candle 1 English candle = 1.095 Hefner units, works out to an efficiency of 37 candles per foot in burners probably consuming between 0.5 and 0.7 foot per hour. Even when allowance is made for the difficulties in determining illuminating power, especially when different photometers, different standards of light, and different observers are concerned, it will be seen that these results are too irregular to be altogether trustworthy, and that much more work must be done on this subject before the economy of the acetylene flame can be appraised with exactitude. However, as certain fixed data are necessary, the authors have studied those and other determinations, rejecting some extreme figures, and averaging the remainder; whence it appears that on an average twin-injector burners of different sizes should yield light somewhat as follows: _______________________________________________________ | | | | | Size of Burner in | Candle-power | Candles | | Cubic Feet per Hour. | Developed. | per Cubic Foot. | |______________________|______________|_________________| | | | | | 0.5 | 18.0 | 35.9 | | 0.7 | 27.0 | 38.5 | | 1.0 | 45.6 | 45.6 | |______________________|______________|_________________| In the tabular statement in Chapter I. the 0.7-foot burner was taken as the standard, because, considering all things, it seems the best, to adopt for domestic purposes. The 1-foot burner is more economical when in the best condition, but requires a higher gas pressure, and is rather too powerful a unit light for good illuminating effect; the 0.5 burner naturally gives a better illuminating effect, but its economy is surpassed by the 0.7-foot burner, which is not too powerful for the human eye. For convenience of comparison, the illuminating powers and duties of the 0.5- and 0.7-foot acetylene burners may be given in different ways: ILLUMINATING POWER OF SELF-LUMINOUS ACETYLENE. _0.7-foot Burner._ | _Half-foot Burner._ | 1 litre = 1.36 candles. | 1 litre = 1.27 candles. 1 cubic foot = 38.5 candles. | 1 cubic foot = 35.9 candles. 1 candle = 0.736 litre. | 1 candle = 0.79 litre. 1 candle = 0.026 cubic foot. | 1 candle = 0.028 cubic foot. If the two streams of gas impinge at an angle of 90°, twin-injector burners for acetylene appear to work best when the gas enters them at a pressure of 2 to 2.5 inches; for a higher pressure the angle should be made a little acute. Large burners require to have a wider distance between the jets, to be supplied with acetylene at a higher pressure, and to be constructed with a smaller angle of impingement. Every burner, of whatever construction and size, must always be supplied with gas at its proper pressure; a pressure varying from time to time is fatal. It is worth observing that although injector burners are satisfactory in practice, and are in fact almost the only jets yet found to give prolonged satisfaction, the method of injecting air below the point of combustion in a self-luminous burner is in some respects wrong in principle. If acetylene can be consumed without polymerisation in burners of the simple fish-tail or bat's-wing type, it should show a higher illuminating efficiency. In 1902 Javal stated that it was possible to burn thoroughly purified acetylene in twin non-injector burners, provided the two jets, made of steatite as usual, were arranged horizontally instead of obliquely, the two streams of gas then meeting at an angle of 180°, so as to yield an almost circular flame. According to Javal, whereas carbonaceous growths were always produced in non-injector acetylene burners with either oblique or horizontal jets, in the former case the growths eventually distorted the gas orifices, but in the latter the carbon was deposited in the form of a tube, and fell off from the burner by its own weight directly it had grown to a length of 1.2 or 1.5 millimetres, leaving the jets perfectly clear and smooth. Javal has had such a burner running for 10 or 12 hours per day for a total of 2071 hours; it did not need cleaning out on any occasion, and its consumption at the end of the period was the same as at first. He found that it was necessary that the tips should be of steatite, and not of metal or glass; that the orifices should be drilled in a flat surface rather than at the apex of a cone, and that the acetylene should be purified to the utmost possible extent. Subsequent experience has demonstrated the possibility of constructing non-injector burners such as that shown in Fig. 13, which behave satisfactorily even though the jets are oblique. But with such burners trouble will inevitably ensue unless the gas is always purified to a high degree and is tolerably dry and well filtered. Non-injector burners should not be used unless special care is taken to insure that the installation is consistently operated in an efficient manner in these respects. GLOBES, &C.--It does not fall within the province of the present volume to treat at length of chimneys, globes, or the various glassware which may be placed round a source of light to modify its appearance. It should be remarked, however, that obedience to two rules is necessary for complete satisfaction in all forms of artificial illumination. First, no light much stronger in intensity than a single candle ought ever to be placed in such a position in an occupied room that its direct rays can reach the eye, or the vision will be temporarily, and may be permanently, injured. Secondly, unless economy is to be wholly ignored, no coloured or tinted globe or shade should ever be put round a source of artificial light. The best material for the construction of globes is that which possesses the maximum of translucency coupled with non-transparency, _i.e._, a material which passes the highest proportion of the light falling upon it, and yet disperses that light in such different directions that the glowing body cannot be seen through the globe. Very roughly speaking, plain white glass, such as that of which the chimneys of oil-lamps and incandescent gas-burners are composed, is quite transparent, and therefore affords no protection to the eyesight; a protective globe should be rather of ground or opal glass, or of plain glass to which a dispersive effect has been given by forming small prisms on its inner or outer surface, or both. Such opal, ground, or dispersive shades waste much light in terms of illuminating power, but waste comparatively little in illuminating effect well designed, they may actually increase the illuminating effect in certain positions; a tinted globe, even if quite plain in figure, wastes both illuminating power and effect, and is only to be tolerated for so-believed aesthetic reasons. Naturally no globe must be of such figure, or so narrow at either orifice, as to distort the shape of the unshaded acetylene flame--it is hardly necessary to say this now, but some years ago coal-gas globes were constructed with an apparent total disregard of this fundamental point. CHAPTER IX INCANDESCENT BURNERS--HEATING APPARATUS--MOTORS--AUTOGENOUS SOLDERING MERITS OF LIGHTING BY INCANDESCENT MANTLES.--It has already been shown that acetylene bases its chief claim for adoption as an illuminant in country districts upon the fact that, when consumed in simple self- luminous burners, it gives a light comparable in all respects save that of cost to the light of incandescent coal-gas. The employment of a mantle is still accompanied by several objections which appear serious to the average householder, who is not always disposed either to devote sufficient attention to his burners to keep them in a high state of efficiency or to contract for their maintenance by the gas company or others. Coal-gas cannot be burnt satisfactorily on the incandescent system unless the glass chimneys and shades are kept clean, unless the mantles are renewed as soon as they show signs of deterioration, and, perhaps most important of all, unless the burners are frequently cleared of the dust which collects round the jets. For this reason luminous acetylene ranks with luminous coal-gas in convenience and simplicity, while ranking with incandescent coal-gas in hygienic value. Very similar remarks apply to paraffin, and, in certain countries, to denatured alcohol. Since those latter illuminants are also available in rural places where coal-gas is not laid on, luminous acetylene is a less advantageous means of procuring artificial light than paraffin (and on occasion than coal-gas and alcohol when the latter fuels are burnt under the mantle), if the pecuniary aspect of the question is the only one considered. Such a comparison, however, is by no means fair; for if coal- gas, paraffin, and alcohol can be consumed on the incandescent system, so can acetylene; and if acetylene is hygienically equal to incandescent coal-gas, it is superior thereto when also burnt under the mantle. Nevertheless there should be one minor but perfectly irremediable defect in incandescent acetylene, viz., a sacrifice of that characteristic property of the luminous gas to emit a light closely resembling that of the sun in tint, which was mentioned in Chapter 1. Self-luminous acetylene gives the whitest light hitherto procurable without special correction of the rays, because its light is derived from glowing particles of carbon which happen to be heated (because of the high flame temperature) to the best possible temperature for the emission of pure white light. The light of any combustible consumed on the "incandescent" system is derived from glowing particles of ceria, thoria, or similar metallic oxides; and the character or shade of the light they emit is a function, apart from the temperature to which they are raised, of their specific chemical nature. Still, the light of incandescent acetylene is sufficiently pleasant, and according to Caro is purer white than that of incandescent coal-gas; but lengthy tests carried out by one of the authors actually show it to be appreciably inferior to luminous acetylene for colour-matching, in which the latter is known almost to equal full daylight, and to excel every form of artificial light except that of the electric arc specially corrected by means of glass tinted with copper salts. CONDITIONS FOR INCANDESCENT ACETYLENE LIGHTING.--For success in the combustion of acetylene on the incandescent system, however, several points have to be observed. First, the gas must be delivered at a strictly constant pressure to the burner, and at one which exceeds a certain limit, ranging with different types and different sizes of burner from 2 to 4 or 5 inches of water. (The authors examined, as long ago as 1903, an incandescent burner of German construction claimed to work at a pressure of 1.5 inches, which it was almost impossible to induce to fire back to the jets however slowly the cock was manipulated, provided the pressure of the gas was maintained well above the point specified. But ordinarily a pressure of about 4 inches is used with incandescent acetylene burners.) Secondly, it is necessary that the acetylene shall at all times be free from appreciable admixture with air, even 0.5 per cent, being highly objectionable according to Caro; so that generators introducing any noteworthy amount of air into the holder each time their decomposing chambers are opened for recharging are not suitable for employment when incandescent burners are contemplated. The reason for this will be more apparent later on, but it depends on the obvious fact that if the acetylene already contains an appreciable proportion of air, when a further quantity is admitted at the burner inlets, the gaseous mixture contains a higher percentage of oxygen than is suited to the size and design of the burner, so that flashing back to the injector jets is imminent at any moment, and may be determined by the slightest fluctuation in pressure--if, indeed, the flame will remain at the proper spot for combustion at all. Thirdly, the fact that the acetylene which is to be consumed under the mantle must be most rigorously purified from phosphorus compounds has been mentioned in Chapter V. Impure acetylene will often destroy a mantle in two or three hours; but with highly purified gas the average life of a mantle may be taken, according to Giro, at 500 or 600 hours. It is safer, however, to assume a rather shorter average life, say 300 to 400 burning hours. Fourthly, owing to the higher pressure at which acetylene must be delivered to an incandescent burner and to the higher temperature of the acetylene flame in comparison with coal-gas, a mantle good enough to give satisfactory results with the latter does not of necessity answer with acetylene; in fact, the authors have found that English Welsbach coal-gas mantles of the small sizes required by incandescent acetylene burners are not competent to last for more than a very few hours, although, in identical conditions, mantles prepared specially for use with acetylene have proved durable. The atmospheric acetylene flame, too, differs in shape from an atmospheric flame of coal-gas, and it does not always happen that a coal- gas mantle contracts to fit the former; although it usually emits a better light (because it fits better) after some 20 hours use than at first. Caro has stated that to derive the best results a mantle needs to contain a larger proportion of ceria than the 1 per cent. present in mantles made according to the Welsbach formula, that it should be somewhat coarser in mesh, and have a large orifice at the head. Other authorities hold that mantles for acetylene, should contain other rare earths besides the thoria and ceria of which the coal-gas mantles almost wholly consist. It seems probable, however, that the composition of the ordinary impregnating fluid need not be varied for acetylene mantles provided it is of the proper strength and the mantles are raised to a higher temperature in manufacture than coal-gas mantles by the use of either coal-gas at very high pressure or an acetylene flame. The thickness of the substance of the mantle cannot be greatly increased with a view to attaining greater stability without causing a reduction in the light afforded. But the shape should be such that the mantle conforms as closely as possible to the acetylene Bunsen flame, which differs slightly with different patterns of incandescent burner heads. According to L. Cadenel, the acetylene mantle should be cylindrical for the lower two- thirds of its length, and slightly conical above, with an opening of moderate size at the top. The head of the mantle should be of slighter construction than that of coal-gas mantles. Fifthly, generators belonging to the automatic variety, which in most forms inevitably add more or less air to the acetylene every time they are cleaned or charged, appear to have achieved most popularity in Great Britain; and these frequently do not yield a gas fit for use with the mantle. This state of affairs, added to what has just been said, makes it difficult to speak in very favourable terms of the incandescent acetylene light for use in Great Britain. But as the advantages of an acetylene not contaminated with air are becoming more generally recognised, and mantles of several different makes are procurable more cheaply, incandescent acetylene is now more practicable than hitherto. Carburetted acetylene or "carburylene," which is discussed later, is especially suitable for use with mantle burners. ATMOSPHERIC ACETYLENE BURNERS.--The satisfactory employment of acetylene in incandescent burners, for boiling, warming, and cooking purposes, and also to some extent as a motive power in small engines, demands the production of a good atmospheric or non-luminous flame, _i.e._, the construction of a trustworthy burner of the Bunsen type. This has been exceedingly difficult to achieve for two reasons: first, the wide range over which mixtures of acetylene and air are explosive; secondly, the high speed at which the explosive wave travels through such a mixture. It has been pointed out in Chapter VIII. that a Bunsen burner is one in which a certain proportion of air is mixed with the gas before it arrives at the actual point of ignition; and as that proportion must be such that the mixture falls between the upper and lower limits of explosibility, there is a gaseous mixture in the burner tube between the air inlets and the outlet which, if the conditions are suitable, will burn with explosive force: that is to say, will fire back to the air jets when a light is applied to the proper place for combustion. Such an explosion, of course, is far too small in extent to constitute any danger to person or property; the objection to it is simply that the shock of the explosion is liable to fracture the fragile incandescent mantle, while the gas, continuing to burn within the burner tube (in the case of a warming or cooking stove), blocks up that tube with carbon, and exhibits the other well-known troubles of a coal-gas stove which has "fired back." It has been shown, however, in Chapter VI. that the range over which mixtures of acetylene and air are explosive depends on the size of the vessel, or more particularly on the diameter of the tube, in which they are stored; so that if the burner tube between the air inlets and the point of ignition can be made small enough in diameter, a normally explosive mixture will cease to exhibit explosive properties. Manifestly, if a tube is made very small in diameter, it will only pass a small volume of gas, and it may be useless for the supply of an atmospheric burner; but Le Chatelier's researches have proved that a tube may be narrowed at one spot only, in such fashion that the explosive wave refuses to pass the constriction, while the virtual diameter of the tube, as far as passage of gas is concerned, remains considerably larger than the size of the constriction itself. Moreover, inasmuch as the speed of propagation of the explosion is strictly fixed by the conditions prevailing, if the speed at which the mixture, of acetylene and air travels from the air inlets to the point of ignition is more rapid than the speed at which the explosion tends to travel from the point of ignition to the air inlets, the said mixture of acetylene and air will burn quietly at the orifice without attempting to fire backwards into the tube. By combining together these two devices: by delivering the acetylene to the injector jet at a pressure sufficient to drive the mixture of gas and air forward rapidly enough, and by narrowing the leading tube either wholly or at one spot to a diameter small enough, it is easy to make an atmospheric burner for acetylene which behaves perfectly as long as it is fairly alight, and the supply of gas is not checked; but further difficulties still remain, because at the instant of lighting and extinguishing, i.e., while the tap is being turned on or off, the pressure of the gas is too small to determine a flow of acetylene and air within the tube at a speed exceeding that of the explosive wave; and therefore the act of lighting or extinguishing is very likely to be accompanied by a smart explosion severe enough to split the mantle, or at least to cause the burner to fire back. Nevertheless, after several early attempts, which were comparative failures, atmospheric acetylene burners have been constructed that work quite satisfactorily, so that the gas has become readily available for use under the mantle, or in heating stoves. Sometimes success has been obtained by the employment of more than one small tube leading to a common place of ignition, sometimes by the use of two or more fine wire- gauze screens in the tube, sometimes by the addition of an enlarged head to the burner in which head alone thorough mixing of the gas and air occurs, and sometimes by the employment of a travelling sleeve which serves more or less completely to block the air inlets. DUTY OF INCANDESCENT ACETYLENE BURNERS.--Granting that the petty troubles and expenses incidental to incandescent lighting are not considered prohibitive--and in careful hands they are not really serious-- and that mantles suitable for acetylene are employed, the gas may be rendered considerably cheaper to use per unit of light evolved by consuming it in incandescent burners. In Chapter VIII. it was shown that the modern self-luminous, l/2-foot acetylene burner emits a light of about 1.27 standard English candles per litre-hour. A large number of incandescent burners, of German and French construction, consuming from 7.0 to 22.2 litres per hour at pressures ranging between 60 and 120 millimetres have been examined by Caro, who has found them to give lights of from 10.8 to 104.5 Hefner units, and efficiencies of from 2.40 to 5.50 units per litre-hour. Averaging his results, it may be said that incandescent burners consuming from 10 to 20 litres per hour at pressures of 80 or 100 millimetres yield a light of 4.0 Hefner units per litre- hour. Expressed in English terms, incandescent acetylene burners consuming 0.5 cubic foot per hour at a pressure of 3 or 4 inches give the duties shown in the following table, which may advantageously be compared with that printed in Chapter VIII., page 239, for the self-luminous gas: ILLUMINATING POWER OF INCANDESCENT ACETYLENE. HALF-FOOT BURNERS. 1 litre = 3.65 candles | 1 candle = 0.274 litre. 1 cubic foot = 103.40 candles. | 1 candle = 0.0097 cubic foot. A number of tests of the Güntner or Schimek incandescent burners of the 10 and 15 litres-per-hour sizes, made by one of the authors in 1906, gave the following average results when tested at a pressure of 4 inches: _________________________________________________________________ | | | | | | Nominal size | Rate of Consumption per | Light in | Duty | | of Burner. | Hour | Candles | Candles per | | | | | Cubic Foot | |______________|_________________________|__________|_____________| | | | | | | | Litres. | Cubic Foot | Litres | | | | 10 | 0.472 | 13.35 | 46.0 | 97.4 | | 15 | 0.663 | 18.80 | 70.0 | 105.5 | |______________|____________|____________|__________|_____________| These figures indicate that the duty increases slightly with the size of the burner. Other tests showed that the duty increased more considerably with an increase of pressure, so that mantles used, or which had been previously used, at a pressure of 5 inches gave duties of 115 to 125 candles per cubic foot. It should be noted that the burners so far considered are small, being intended for domestic purposes only; larger burners exhibit higher efficiencies. For instance, a set of French incandescent acetylene burners examined by Fouché showed: _________________________________________________________________ | | | | | | | Size of Burner | Pressure | Cubic Feet | Light in | Candles per | | in Litres. | Inches. | per Hour. | Candles. | Cubic Feet. | |________________|__________|____________|__________|_____________| | | | | | | | 20 | 5.9 | 0.71 | 70 | 98.6 | | 40 | 5.9 | 1.41 | 150 | 106.4 | | 70 | 5.9 | 2.47 | 280 | 113.4 | | 120 | 5.9 | 4.23 | 500 | 118.2 | |________________|__________|____________|__________|_____________| By increasing the pressure at which acetylene is introduced into burners of this type, still larger duties may be obtained from them: _________________________________________________________________ | | | | | | | Size of Burner | Pressure | Cubic Feet | Light in | Candles per | | in Litres. | Inches. | per Hour. | Candles. | Cubic Feet. | |________________|__________|____________|__________|_____________| | | | | | | | 55 | 39.4 | 1.94 | 220 | 113.4 | | 100 | 39.4 | 3.53 | 430 | 121.8 | | 180 | 39.4 | 6.35 | 820 | 129.1 | | 260 | 27.6 | 9.18 | 1300 | 141.6 | |________________|__________|____________|__________|_____________| High-power burners such as these are only fit for special purposes, such as lighthouse illumination, or optical lantern work, &c.; and they naturally require mantles of considerably greater tenacity than those intended for employment with coal-gas. Nevertheless, suitable mantles can be, and are being, made, and by their aid the illuminating duty of acetylene can be raised from the 30 odd candles per foot of the common 0.5-foot self-luminous jet to 140 candles or more per foot, which is a gain in efficiency of 367 per cent., or, neglecting upkeep and sundries and considering only the gas consumed, an economy of nearly 79 per cent. In 1902, working apparently with acetylene dissolved under pressure in acetone (_cf._ Chapter XI.), Lewes obtained the annexed results with the incandescent gas: ________________________________________________________ | | | | | | Pressure. | Cubic Feet | Candle Power | Candles per | | Inches. | per Hour. | Developed. | Cubic Foot. | |___________|_____________|______________|______________| | | | | | | 8 | 0.883 | 65 | 73.6 | | 9 | 0.94 | 72 | 76.0 | | 10 | 1.00 | 146 | 146.0 | | 12 | 1.06 | 150 | 141.2 | | 15 | 1.25 | 150 | 120.0 | | 20 | 1.33 | 166 | 124.8 | | 25 | 1.50 | 186 | 123.3 | | 40 | 2.12 | 257 | 121.2 | |___________|_____________|______________|______________| It will be seen that although the total candle-power developed increases with the pressure, the duty of the burner attained a maximum at a pressure of 10 inches. This is presumably due to the fact either that the same burner was used throughout the tests, and was only intended to work at a pressure of 10 inches or thereabouts, or that the larger burners were not so well constructed as the smaller ones. Other investigators have not given this maximum of duty with a medium-sized or medium-driven burner; but Lewes has observed a similar phenomenon in the case of 0.7 to 0.8 cubic foot self-luminous jets. Figures, however, which seem to show that the duty of incandescent acetylene does not always rise with the size of the burner or with the pressure at which the gas is delivered to it, have been published in connexion with the installation at the French lighthouse at Chassiron, the northern point of the Island of Oléron. Here the acetylene is generated in hand-fed carbide-to-water generators so constructed as to give any pressure up to nearly 200 inches of water column; purified by means of heratol, and finally delivered to a burner composed of thirty- seven small tubes, which raises to incandescence a mantle 55 millimetres in diameter at its base. At a pressure of 7.77 inches of water, the burner passes 3.9 cubic feet of acetylene per hour, and at a pressure of 49.2 inches (the head actually used) it consumes 20.06 cubic feet per hour. As shown by the following table, such increment of gas pressure raises the specific intensity of the light, _i.e._, the illuminating power per unit of incandescent surface, but it does not appreciably raise the duty or economy of the gas. Manifestly, in terms of duty alone, a pressure of 23.6 inches of water-column is as advantageous as the higher Chassiron figures; but since intensity of light is an important matter in a lighthouse, it is found better on the whole to work the generators at a pressure of 49.2 inches. In studying these figures referring to the French lighthouse, it is interesting to bear in mind that when ordinary six-wick petroleum oil burners wore used in the same place, the specific intensity of the light developed was 75 candle-power per square inch, and when that plant was abandoned in favour of an oil-gas apparatus, the incandescent burner yielded 161 candle-power per square inch; substitution of incandescent acetylene under pressure has doubled the brilliancy of the light. ___________________________________________________________ | | | | | | Duty. | Intensity. | | Pressure in Inches. | Candle-power per | Candle-power per | | | Cubic Foot. | Square Inch. | |_____________________|__________________|__________________| | | | | | 7.77 | 105.5 | 126.0 | | 23.60 | 106.0 | 226.0 | | 31.50 | 110.0 | 277.0 | | 39.40 | 110.0 | 301.0 | | 47.30 | 106.0 | 317.0 | | 49.20 | 104.0 | 324.9 | | 196.80 | 110.0 | 383.0 | |_____________________|__________________|__________________| When tested in modern burners consuming between 12 and 18 litres per hour at a pressure of 100 millimetres (4 inches), some special forms of incandescent mantles constructed of ramie fibre, which in certain respects appears to be better suited than cotton for use with acetylene, have shown the following degree of loss in illuminating power after prolonged employment (Caro): _Luminosity in Hefner Units._ ________________________________________________________ | | | | | | | Mantle. | New. | After | After | After | | | | 100 Hours. | 200 Hours. | 400 Hours. | |_________|_______|____________|____________|____________| | | | | | | | No. 1. | 53.2 | 51.8 | 50.6 | 49.8 | | No. 2. | 76.3 | 75.8 | 73.4 | 72.2 | | No. 3. | 73.1 | 72.5 | 70.1 | 68.6 | |_________|_______|____________|____________|____________| It will be seen that the maximum loss of illuminating power in 400 hours was 6.4 per cent., the average loss being 6.0 per cent. TYPICAL INCANDESCENT BURNERS.--Of the many burners for lighting by the use of incandescent mantles which have been devised, a few of the more widely used types may be briefly referred to. There is no doubt that finality in the design of these burners has not yet been reached, and that improvements in the direction of simplification of construction and in efficiency and durability will continue to be made. Among the early incandescent burners, one made by the Allgemeine Carbid und Acetylen Gesellschaft of Berlin in 1900 depended on the narrowness of the mixing tube and the proportioning of the gas nipple and air inlets to prevent lighting-back. There was a wider concentric tube round the upper part of the mixing tube, and the lower part of the mantle fitted round this. The mouth of the mixing tube of this 10-litres-per-hour burner was 0.11 inch in diameter, and the external diameter of the middle cylindrical part of the mixing tube was 0.28 inch. There was no gauze diaphragm or stuffing, and firing-back did not occur until the pressure was reduced to about 1.5 inches. The same company later introduced a burner differing in several important particulars from the one just described. The comparatively narrow stem of the mixing tube and the proportions of the gas nipple and air inlets were retained, but the mixing tube was surmounted by a wide chamber or burner head, in which naturally there was a considerable reduction in the rate of flow of the gas. Consequently it was found necessary to introduce a gauze screen into the burner head to prevent firing back. The alterations have resulted in the lighting duty of the burner being considerably improved. Among other burners designed about 1900 may be mentioned the Ackermann, the head of which consisted of a series of tubes from each of which a jet of flame was produced, the Fouché, the Weber, and the Trendel. Subsequently a tubular-headed burner known as the Sirius has been produced for the consumption of acetylene at high pressure (20 inches and upwards). The more recent burners which have been somewhat extensively used include the "Schimek," made by W. Güntner of Vienna, which is shown in Fig. 19. It consists of a tapering narrow injecting nozzle within a conical chamber C which is open below, and is surmounted by the mixing tube over which telescopes a tube which carries the enlarged burner head G, and the chimney gallery D. There are two diaphragms of gauze in the burner head to prevent firing back, and one in the nozzle portion of the burner. The conical chamber has a perforated base-plate below which is a circular plate B which rotates on a screw cut on the lower part of the nozzle portion A of the burner. This plate serves as a damper to control the amount of air admitted through the base of the conical chamber to the mixing tube. There are six small notches in the lower edge of the conical chamber to prevent the inflow of air being cut of entirely by the damper. The mixing tube in both the 10-litre and the 15-litre burner is about 0.24 inch in internal diameter but the burner head is nearly 0.42 inch in the 10-litre and 0.48 inch in the 15-litre burner. The opening in the head of the burner through which the mixture of gas and air escapes to the flame is 0.15 and 0.17 inch in diameter in these two sizes respectively. The results of some testings made with Schimek burners have been already given. [Illustration: FIG. 19.--"SCHIMEK" BURNER.] The "Knappich" burner, made by the firm of Keller and Knappich of Augsburg, somewhat resembles the later pattern of the Allgemeine Carbid und Acetylen Gesellschaft. It has a narrow mixing tube, viz., 0.2 inch in internal diameter, and a wide burner head, viz., 0.63 inch in internal diameter for the 25-litre size. The only gauze diaphragm is in the upper part of the burner head. The opening in the cap of the burner head, at which the gas burns, is 0.22 inch in diameter. The gas nipple extends into a domed chamber at the base of the mixing tube, and the internal air is supplied through four holes in the base-plate of that chamber. No means of regulating the effective area of the air inlet holes are provided. The "Zenith" burner, made by the firm of Gebrüder Jacob of Zwickau, more closely resembles the Schimek, but the air inlets are in the side of the lower widened portion of the mixing tube, and are more or less closed by means of an outside loose collar which may be screwed up and down on a thread on a collar fixed to the mixing tube. The mixing tube is 0.24 inch, and the burner head 0.475 inch in internal diameter. The opening in the cap of the burner is 0.16 inch in diameter. There is a diaphragm of double gauze in the cap, and this is the only gauze used in the burner. All the incandescent burners hitherto mentioned ordinarily have the gas nipple made in brass or other metal, which is liable to corrosion, and the orifice to distortion by heat or if it becomes necessary to remove any obstruction from it. The orifice in the nipple is extremely small-- usually less than 0.015 inch--and any slight obstruction or distortion would alter to a serious extent the rate of flow of gas through it, and so affect the working of the burner. In order to overcome this defect, inherent to metal nipples, burners are now constructed for acetylene in which the nipple is of hard incorrodible material. One of these burners has been made on behalf of the Office Central de l'Acétylène of Paris, and is commonly known as the "O.C.A." burner. In it the nipple is of steatite. On the inner mixing tube of this burner is mounted an elongated cone of wire wound spirally, which serves both to ensure proper admixture of the gas and air, and to prevent firing-back. There is no gauze in this burner, and the parts are readily detachable for cleaning when required. Another burner, in which metal is abolished for the nipple, is made by Geo. Bray and Co., Ltd., of Leeds, and is shown in Fig. 20. In this burner the injecting nipple is of porcelain. [Illustration: FIG. 20.--BRAY'S INCANDESCENT BURNER.] ACETYLENE FOR HEATING AND COOKING.--Since the problem of constructing a trustworthy atmospheric burner has been solved, acetylene is not only available for use in incandescent lighting, but it can also be employed for heating or cooking purposes, because all boiling, most warming, and some roasting stoves are simply arrangements for utilising the heat of a non-luminous flame in one particular way. With suitable alterations in the dimensions of the burners, apparatus for consuming coal-gas may be imitated and made fit to burn acetylene; and as a matter of fact several firms are now constructing such appliances, which leave little or nothing to be desired. It may perhaps be well to insist upon the elementary point which is so frequently ignored in practice, viz., that no stove, except perhaps a small portable boiling ring, ought ever to be used in an occupied room unless it is connected with a chimney, free from down- draughts, for the products of combustion to escape into the outer air; and also that no chimney, however tall, can cause an up-draught in all states of the weather unless there is free admission of fresh air into the room at the base of the chimney. Still, at the prices for coal, paraffin oil, and calcium carbide which exist in Great Britain, acetylene is not an economical means of providing artificial heat. If a 0.7 cubic foot luminous acetylene burner gives a light of 27 candles, and if ordinary country coal-gas gives light of 12 to 13 candles in a 5-foot burner, one volume of acetylene is equally valuable with 15 or 16 volumes of coal-gas when both are consumed in self-luminous jets; and if, with the mantle, acetylene develops 99 candles per cubic foot, while coal-gas gives in common practice 15 to 20 candles, one volume of acetylene is equally valuable with 5 to 6-1/2 volumes of coal-gas when both are consumed on the incandescent system; whereas, if the acetylene is burnt in a flat flame, and the coal-gas under the mantle, 1 volume of the former is equally efficient with 2 volumes of coal-gas as an artificial illuminant. This last method of comparison being manifestly unfair, acetylene may be said to be at least five times as efficient per unit of volume as coal-gas for the production of light. But from the table given on a later page it appears that as a source of artificial heat, acetylene is only equal to about 2-3 times its volume of ordinary coal-gas. Nevertheless, the domestic advantages of gas firing are very marked; and when a properly constructed stove is properly installed, the hygienic advantages of gas-firing are alone equally conspicuous--for the disfavor with which gas-firing is regarded by many physicians is due to experience gained with apparatus warming principally by convection [Footnote: Radiant heat is high-temperature heat, like the heat emitted by a mass of red-hot coke; convected heat is low-temperature heat, invisible to the eye. Radiant heat heats objects first, and leaves them to warm the air; convected heat is heat applied directly to air, and leaves the air to warm objects afterwards. On all hygienic grounds radiant heat is better than convected heat, but the latter is more economical. By an absurd and confusing custom, that particular warming apparatus (gas, steam, or hot water) which yields practically no radiant heat, and does all its work by convection, is known to the trade as a "radiator."] instead of radiation; or to acquaintance with intrinsically better stoves either not connected to any flues or connected to one deficient in exhausting power. In these circumstances, whenever an installation of acetylene has been laid down for the illumination of a house or district, the merit of convenience may outweigh the defect of extravagance, and the gas may be judiciously employed in a boiling ring, or for warming a bedroom; while, if pecuniary considerations are not paramount, the acetylene may be used for every purpose to which the townsman would apply his cheaper coal-gas. The difficulty of constructing atmospheric acetylene burners in which the flame would not be likely to strike back to the nipple has already been referred to in connexion with the construction atmospheric burners for incandescent lighting. Owing, however, to the large proportions of the atmospheric burners of boiling rings and stove and in particular to the larger bore of their mixing tube, the risk of the flame striking back is greater with them, than with incandescent lighting burners. The greatest trouble is presented at lighting, and when the pressure of the gas-supply is low. The risk of firing-back when the burner is lighted is avoided in some forms of boiling rings, &c., by providing a loose collar which can be slipped over the air inlets of the Bunsen tube before applying a light to the burner, and slipped clear of them as soon as the burner is alight. Thus at the moment of lighting, the burner is converted temporarily into one of the non-atmospheric type, and after the flame has thus been established at the head or ring of the burner, the internal air-supply is started by removing the loose collar from the air inlets, and the flame is thus made atmospheric. In these conditions it does not travel backwards to the nipple. In other heating burners it is generally necessary to turn on the gas tap a few seconds before applying a light to the burner or ring or stove; the gas streaming through the mixing tube then fills it with acetylene and air mixed in the proper working proportions, and when the light is applied, there is no explosion in the mixing tube, or striking-back of the flame to the nipple. Single or two-burner gas rings for boiling purposes, or for heating cooking ovens, known as the "La Belle," made by Falk Stadelmann and Co., Ltd., of London, may be used at as low a gas pressure as 2 inches, though they give better results at 3 inches, which is their normal working pressure. The gas-inlet nozzle or nipple of the burner is set within a spherical bulb in which are four air inlets. The mixing tube which is placed at a proper distance in front of the nipple, is proportioned to the rate of flow of the gas and air, and contains a mixing chamber with a baffling pillar to further their admixture. A fine wire gauze insertion serves to prevent striking-back of the flame. A "La Belle" boiling ring consumes at 3 inches pressure about 48 litres or 1.7 cubic feet of acetylene per hour. ACETYLENE MOTORS.--The question as to the feasibility of developing "power" from acetylene, _i.e._, of running an engine by means of the gas, may be answered in essentially identical terms. Specially designed gas-engines of 1, 3, 6, or even 10 h.p. work perfectly with acetylene, and such motors are in regular employment in numerous situations, more particularly for pumping water to feed the generators of a large village acetylene installation. Acetylene is not an economical source of power, partly for the theoretical reason that it is a richer fuel even than coal-gas, and gas-engines would appear usually to be more efficient as the fuel they burn is poorer in calorific intensity, _i.e._, in heating power (which is explosive power) per unit of volume. The richer, or more concentrated, any fuel in, the more rapidly does the explosion in a mixture of that fuel with air proceed, because a rich fuel contains a smaller proportion of non-inflammable gases which tend to retard explosion than a poor one; and, in reason, a gas-engine works better the more slowly the mixture of gas and air with which it is fed explodes. Still, by properly designing the ports of a gas-engine cylinder, so that the normal amount of compression of the charge and of expansion of the exploded mixture which best suit coal-gas are modified to suit acetylene, satisfactory engines can be constructed; and wherever an acetylene installation for light exists, it becomes a mere question of expediency whether the same fuel shall not be used to develop power, say, for pumping up the water required in a large country house, instead of employing hand labour, or the cheaper hot-air or petroleum motor. Taking the mean of the results obtained by numerous investigators, it appears that 1 h.p.-hour can be obtained for a consumption of 200 litres of acetylene; whence it may be calculated that that amount of energy costs about 3d. for gas only, neglecting upkeep, lubricating material (which would be relatively expensive) and interest, &c. Acetylene Blowpipes--The design of a satisfactory blowpipe for use with acetylene had at first proved a matter of some difficulty, since the jet, like that of an ordinary self-luminous burner, usually exhibited a tendency to become choked with carbonaceous growths. But when acetylene had become available for various purposes at considerable pressure, after compression into porous matter as described in Chapter XI, the troubles were soon overcome; and a new form of blowpipe was constructed in which acetylene was consumed under pressure in conjunction with oxygen. The temperature given by this apparatus exceeds that of the familiar oxy- hydrogen blowpipe, because the actual combustible material is carbon instead of hydrogen. When 2 atoms of hydrogen unite with 1 of oxygen to form 1 molecule of gaseous water, about 59 large calories are evolved, and when 1 atom of solid amorphous carbon unites with 2 atoms of oxygen to form 1 molecule of carbon dioxide, 97.3 calories are evolved. In both cases, however, the heat attainable is limited by the fact that at certain temperatures hydrogen and oxygen refuse to combine to form water, and carbon and oxygen refuse to form carbon dioxide--in other words, water vapour and carbon dioxide dissociate and absorb heat in the process at certain moderately elevated temperatures. But when 1 atom of solid amorphous carbon unites with 1 atom of oxygen to form carbon monoxide, 29.1 [Footnote: Cf. Chapter VI., page 185.] large calories are produced, and carbon monoxide is capable of existence at much higher temperatures than either carbon dioxide or water vapour. In any gaseous hydrocarbon, again, the carbon exists in the gaseous state, and when 1 atom of the hypothetical gaseous carbon combines with 1 atom of oxygen to produce 1 molecule of carbon monoxide, 68.2 large calories are evolved. Thus while solid amorphous carbon emits more heat than a chemically equivalent quantity of hydrogen provided it is enabled to combine with its higher proportion of oxygen, it emits less if only carbon monoxide is formed; but a higher temperature can be attained in the latter case, because the carbon monoxide is more permanent or stable. Gaseous carbon, on the other hand, emits more heat than an equivalent quantity of hydrogen, [Footnote: In a blowpipe flame hydrogen can only burn to gaseous, not liquid, water.] even when it is only converted into the monoxide. In other words, a gaseous fuel which consists of hydrogen alone can only yield that temperature as a maximum at which the speed of the dissociation of the water vapour reaches that of the oxidation of the hydrogen; and were carbon dioxide the only oxide of carbon, a similar state of affairs would be ultimately reached in the flame of a carbonaceous gas. But since in the latter case the carbon dioxide does not tend to dissociate completely, but only to lose one atom of oxygen, above the limiting temperature for the formation of carbon dioxide, carbon monoxide is still produced, because there is less dissociating force opposed to its formation. Thus at ordinary temperatures the heat of combustion of acetylene is 315.7 calories; but at temperatures where water vapour and carbon dioxide no longer exist, there is lost to that quantity of 315.7 calories the heat of combustion of hydrogen (69.0) and twice that of carbon monoxide (68.2 x 2 = 136.4); so that above those critical temperatures, the heat of combustion of acetylene is only 315.7 - (69.0 + 136.4) = 110.3. [Footnote: When the heat of combustion of acetylene is quoted as 315.7 calories, it is understood that the water formed is condensed into the liquid state. If the water remains gaseous, as it must do in a flame, the heat of formation is reduced by about 10 calories. This does not affect the above calculation, because the heat of combustion of hydrogen when the water remains gaseous is similarly 10 calories less than 69, _i.e._, 59, as mentioned above in the text. Deleting the heat of liquefaction of water, the calculation referred to becomes 305.7 - (59.0 + l36.4) = 110.3 as before.] This value of 110.3 calories is clearly made up of the heat of formation of acetylene itself, and twice the heat of conversion of carbon into carbon monoxide, _i.e._, for diamond carbon, 58.1 + 26.1 x 2 = 110.3; or for amorphous carbon, 52.1 + 29.1 x 2 = 110.3. From the foregoing considerations, it may be inferred that the acetylene-oxygen blowpipe can be regarded as a device for burning gaseous carbon in oxygen; but were it possible to obtain carbon in the state of gas and so to lead it into a blowpipe, the acetylene apparatus should still be more powerful, because in it the temperature would be raised, not only by the heat of formation of carbon monoxide, but also by the heat attendant upon the dissociation of the acetylene which yields the carbon. Acetylene requires 2.5 volumes of oxygen to burn it completely; but in the construction of an acetylene-oxygen blowpipe the proportion of oxygen is kept below this figure, viz., at 1.1 to 1.8 volumes, so that the deficiency is left to be made up from the surrounding air. Thus at the jet of the blowpipe the acetylene dissociates and its carbon is oxidised, at first no doubt to carbon monoxide only, but afterwards to carbon dioxide; and round the flame of the gaseous carbon is a comparatively cool, though absolutely very hot jacket of hydrogen burning to water vapour in a mixture of oxygen and air, which protects the inner zone from loss of heat. As just explained, theoretical grounds support the conclusions at which Fouché has arrived, viz., that the temperature of the acetylene-oxygen blowpipe flame is above that at which hydrogen will combine with oxygen to form water, and that it can only be exceeded by those found in a powerful electric furnace. As the hydrogen dissociated from the acetylene remains temporarily in the free state, the flame of the acetylene blowpipe, possesses strong reducing powers; and this, coupled probably with an intensity of heat which is practically otherwise unattainable, except by the aid of a high-tension electric current, should make the acetylene-oxygen blowpipe a most useful piece of apparatus for a large variety of metallurgical, chemical, and physical operations. In Fouché's earliest attempts to design an acetylene blowpipe, the gas was first saturated with a combustible vapour, such as that of petroleum spirit or ether, and the mixture was consumed with a blast of oxygen in an ordinary coal-gas blow-pipe. The apparatus worked fairly well, but gave a flame of varying character; it was capable of fusing iron, raised a pencil of lime to a more brilliant degree of incandescence than the eth-oxygen burner, and did not deposit carbon at the jet. The matter, however, was not pursued, as the blowpipe fed with undiluted acetylene took its place. The second apparatus constructed by Fouché was the high-pressure blowpipe, the theoretical aspect of which has already been studied. In this, acetylene passing through a water-seal from a cylinder where it is stored as a solution in acetone (_cf._ Chapter XI.), and oxygen coming from another cylinder, are each allowed to enter the blowpipe at a pressure of 118 to 157 inches of water column (_i.e._, 8.7 to 11.6 inches of mercury; 4.2 to 5.7 lb. per square inch, or 0.3 to 0.4 atmosphere). The gases mix in a chamber tightly packed with porous matter such as that which is employed in the original acetylene reservoir, and finally issue from a jet having a diameter of 1 millimetre at the necessary speed of 100 to 150 metres per second. Finding, however, that the need for having the acetylene under pressure somewhat limited the sphere of usefulness of his apparatus, Fouché finally designed a low-pressure blowpipe, in which only the oxygen requires to be in a state of compression, while the acetylene is drawn directly from any generator of the ordinary pattern that does not yield a gas contaminated with air. The oxygen passes through a reducing valve to lower the pressure under which it stands in the cylinder to that of 1 or 1.5 effective atmosphere, this amount being necessary to inject the acetylene and to give the previously mentioned speed of escape from the blowpipe orifice. The acetylene is led through a system of long narrow tubes to prevent it firing-back. AUTOGENOUS SOLDERING AND WELDING.--The blowpipe is suitable for the welding and for the autogenous soldering or "burning" of wrought or cast iron, steel, or copper. An apparatus consuming from 600 to 1000 litres of acetylene per hour yields a flame whose inner zone is 10 to 15 millimetres long, and 3 to 4 millimetres in diameter; it is sufficiently powerful to burn iron sheets 8 to 9 millimetres thick. By increasing the supply of acetylene in proportion to that of the oxygen, the tip of the inner zone becomes strongly luminous, and the flame then tends to carburise iron; when the gases are so adjusted that this tip just disappears, the flame is at its best for heating iron and steel. The consumption of acetylene is about 75 litres per hour for each millimetre of thickness in the sheet treated, and the normal consumption of oxygen is 1.7 times as much; a joint 6 metres long can be burnt in 1 millimetre plate per hour, and one of 1.5 metres in 10 millimetre plate. In certain cases it is found economical to raise the metal to dull redness by other means, say with a portable forge of the usual description, or with a blowpipe consuming coal-gas and air. There are other forms of low- pressure blowpipe besides the Fouché, in some of which the oxygen also is supplied at low pressure. Apart from the use of cylinders of dissolved acetylene, which are extremely convenient and practically indispensable when the blowpipe has to be applied in confined spaces (as in repairing propeller shafts on ships _in situ_), acetylene generators are now made by several firms in a convenient transportable form for providing the gas for use in welding or autogenous soldering. It is generally supposed that the metal used as solder in soldering iron or steel by this method must be iron containing only a trifling proportion of carbon (such as Swedish iron), because the carbon of the acetylene carburises the metal, which is heated in the oxy-acetylene flame, and would thereby make ordinary steel too rich in carbon. But the extent to which the metal used is carburised in the flame depends, as has already been indicated, on the proper adjustment of the proportion of oxygen to acetylene. Oxy-acetylene autogenous soldering or welding is applicable to a great variety of work, among which may be mentioned repairs to shafts, locomotive frames, cylinders, and to joints in ships' frames, pipes, boilers, and rails. The use of the process is rapidly extending in engineering works generally. Generators for acetylene soldering or welding must be of ample size to meet the quickly fluctuating demands on them and must be provided with water-seals, and a washer or scrubber and filter capable of arresting all impurities held mechanically in the crude gas, and with a safety vent- pipe terminating in the open at a distance from the work in hand. The generator must be of a type which affords as little after-generation as possible, and should not need recharging while the blowpipe is in use. There should be a main tap on the pipe between the generator and the blowpipe. It does not appear conclusively established that the gas consumed should have been chemically purified, but a purifier of ample size and charged with efficient material is undoubtedly beneficial. The blowpipe must be designed so that it remains sufficiently cool to prevent polymerisation of the acetylene and deposition of the resultant particles of carbon or soot within it. It is important to remember that if a diluent gas, such as nitrogen, is present, the superior calorific power of acetylene over nearly all gases should avail to keep the temperature of the flame more nearly up to the temperature at which hydrogen and oxygen cease to combine. Hence a blowpipe fed with air and acetylene would give a higher temperature than any ordinary (atmospheric) coal-gas blowpipe, just as, as has been explained in Chapter VI., an ordinary acetylene flame has a higher temperature than a coal-gas flame. It is likely that a blowpipe fed with "Lindé-air" (oxygen diluted with less nitrogen than in the atmosphere) and acetylene would give as high a limelight effect as the oxy-hydrogen or oxy-coal-gas blowpipe. CHAPTER X CARBURETTED ACETYLENE Now that atmospheric or Bunsen burners for the consumption of acetylene for use in lighting by the incandescent system and in heating have been so much improved that they seem to be within measurable reach of a state of perfection, there appears to be but little use at the present time for a modified or diluted acetylene which formerly seemed likely to be valuable for heating and certain other purposes. Nevertheless, the facts relating to this so-called carburetted acetylene are in no way traversed by its failure to establish itself as an active competitor with simple acetylene for heating purposes, and since it is conceivable that the advantages which from the theoretical standpoint the carburetted gas undoubtedly possesses in certain directions may ultimately lead to its practical utilisation for special purposes, it has been deemed expedient to continue to give in this work an account of the principles underlying the production and application of carburetted acetylene. It has already been explained that acetylene is comparatively a less efficient heating agent than it is an illuminating material, because, per unit of volume, its calorific power is not so much greater than that of coal-gas as is its illuminating capacity. It has also been shown that the high upper explosive limit of mixtures of acetylene and air--a limit so much higher than the corresponding figure with coal-gas and other gaseous fuels--renders its employment in atmospheric burners (either for lighting or for heating) somewhat troublesome, or dependent upon considerable skill in the design of the apparatus. If, therefore, either the upper explosive limit of acetylene could be reduced, or its calorific value increased (or both), by mixing with it some other gas or vapour which should not seriously affect its price and convenience as a self-luminous illuminant, acetylene would compare more favourably with coal-gas in its ready applicability to the most various purposes. Such a method has been suggested by Heil, and has been found successful on the Continent. It consists in adding to the acetylene a certain proportion of the vapour of a volatile hydrocarbon, so as to prepare what is called "carburetted acetylene." In all respects the method of making carburetted acetylene is identical with that of making "air-gas," which was outlined in Chapter I., viz., the acetylene coming from an ordinary generating plant is led over or through a mass of petroleum spirit, or other similar product, in a vessel which exposes the proper amount of superficial area to the passing gas. In all respects save one the character of the product is similar to that of air-gas, _i.e._, it is a mixture of a permanent gas with a vapour; the vapour may possibly condense in part within the mains if they are exposed to a falling temperature, and if the product is to be led any considerable distance, deposition of liquid may occur (conceivably followed by blockage of the mains) unless the proportion of vapour added to the gas is kept below a point governed by local climatic and similar conditions. But in one most important respect carburetted acetylene is totally different from air-gas: partial precipitation of spirit from air-gas removes more or less of the solitary useful constituent of the material, reducing its practical value, and causing the residue to approach or overpass its lower explosive limit (_cf._ Chapter I.); partial removal of spirit from carburetted acetylene only means a partial reconversion of the material into ordinary acetylene, increasing its natural illuminating power, lowering its calorific intensity somewhat, and causing the residue to have almost its primary high upper explosive limit, but essentially leaving its lower explosive limit unchanged. Thus while air-gas may conceivably become inefficient for every purpose if supplied from any distance in very cold weather, and may even pass into a dangerous explosive within the mains; carburetted acetylene can never become explosive, can only lose part of its special heating value, and will actually increase in illuminating power. It is manifest that, like air-gas, carburetted acetylene is of somewhat indefinite composition, for the proportion of vapour, and the chemical nature of that vapour, may vary. 100 litres of acetylene will take up 40 grammes of petroleum spirit to yield 110 litres of carburetted acetylene evidently containing 9 per cent. of vapour, or 100 litres of acetylene may be made to absorb as much as 250 grammes of spirit yielding 200 litres of carburetted acetylene containing 50 per cent. of vapour; while the petroleum spirit may be replaced, if prices are suitable, by benzol or denatured alcohol. The illuminating power of acetylene carburetted with petroleum spirit has been examined by Caro, whose average figures, worked out in British units, are: ILLUMINATING POWER OF CARBURETTED ACETYLENE. HALF-FOOT BURNERS. _Self-luminous._ | _Incandescent_ 1 litre = 1.00 candle. | 1 litre = 3.04 candles. 1 cubic foot = 28.4 candles. | 1 cubic foot = 86.2 candles. 1 candle = 1.00 litre. | 1 candle = 0.33 litre. 1 candle = 0.035 cubic foot. | 1 candle = 0.012 cubic foot. Those results may be compared with those referring to air-gas, which emits in incandescent burners from 3.0 to 12.4 candles per cubic foot according to the amount of spirit added to the air and the temperature to which the gas is exposed. The calorific values of carburetted acetylene (Caro), and those of other gaseous fuels are: Large Calories per _ Cubic Foot. | (Lewes) . 320 | (Gand) . 403 Ordinary acetylene . . | (Heil) . 365 | ___ |_Mean . . 363 | Maximum . 680 Carburetted acetylene . . | Minimum . 467 (petroleum spirit) | ___ |_Mean . . 573 Carburetted acetylene (50 per cent. benzol by volume) 685 Carburetted acetylene (50 per cent. alcohol by volume) 364 Coal-gas (common, unenriched) . . . . . 150 _ | Maximum . 178 Air-gas, self-luminous flame | Minimum . 57 | ___ |_Mean . . . 114 _ | Maximum . 26 Air-gas, non-luminous flame | Minimum . 18 | ___ |_Mean . . . 22 Water-gas (Strache) from coke . . . . . 71 Mond gas (from bituminous coal) . . . . . 38 Semi-water-gas from coke or anthracite . . . 36 Generator (producer) gas . . . . . . 29 Besides its relatively low upper explosive limit, carburetted acetylene exhibits a higher temperature of ignition than ordinary acetylene, which makes it appreciably safer in presence of a naked light. It also possesses a somewhat lower flame temperature and a slower speed of propagation of the explosive wave when mixed with air. These data are: ______________________________________________________________________ | | | | | | | Explosive | Temperature. | | | | Limits. | Degrees C. | Explosive | | |19 mm. Tube. | | Explosive | | |_____________|__________________| Wave. | | | | | | | Metres per | | | | |Of Igni-| | Second. | | |Lower.|Upper.| tion. |Of Flame.| | |________________________|______|______|________|_________|____________| | | | | | | | | Acetylene (theoretical)| --- | --- | --- |1850-2420| --- | | " (observed) | 3.35 | 52.3 | 480 |1630-2020| 0.18-100 | | Carburetted \ from | 2.5 | 10.2 | 582 | 1620 | 3.2 | | acetylene / . . to | 5.4 | 30.0 | 720 | 1730 | 5.3 | | Carburetted acetylene\ | 3.4 | 22.0 | --- | 1820 | 1.3 | | (benzol) . . . / | | | | | | | Carburetted acetylene\ | 3.1 | 12.0 | --- | 1610 | 1.1 | | (alcohol) . . . / | | | | | | | Air-gas, self-luminous\|15.0 | 50.0 | --- |1510-1520| --- | | flame . . . . /| | | | | | | Coal-gas . . . | 7.9 | 19.1 | 600 | --- | --- | |________________________|______|______|________|_________|____________| In making carburetted acetylene, the pressure given by the ordinary acetylene generator will be sufficient to drive the gas through the carburettor, and therefore there will be no expense involved beyond the cost of the spirit vaporised. Thus comparisons may fairly be made between ordinary and carburetted acetylene on the basis of material only, the expense of generating the original acetylene being also ignored. In Great Britain the prices of calcium carbide, petroleum spirit, and 90s benzol delivered in bulk in country places may be taken at 15£ per ton, and 1s. per gallon respectively, petroleum spirit having a specific gravity of 0.700 and benzol of 0.88. On this basis, a unit volume (100 cubic metres) of plain acetylene costs 1135d., of "petrolised" acetylene containing 66 per cent. of acetylene costs 1277d., and of "benzolised" acetylene costs 1180d. In other words, 100 volumes of plain acetylene, 90 volumes of petrolised acetylene, and 96 volumes of benzolised acetylene are of equal pecuniary value. Employing the data given in previous tables, it appears that 38.5 candles can be won from plain acetylene in a self-luminous burner, and 103 candles therefrom in an incandescent burner at the same price as 25.5-29.1 and 78-87 candles can be obtained from carburetted acetylene; whence it follows that at English prices petrolised acetylene is more expensive as an illuminant in either system of combustion than the simple gas, while benzolised acetylene, burnt under the mantle only, is more nearly equal to the simple gas from a pecuniary aspect. But considering the calorific value, it appears that for a given sum of money only 363 calories can be obtained from plain acetylene, while petrolised acetylene yields 516, and benzolised acetylene 658; so that for all heating or cooking purposes (and also for driving small motors) carburetted acetylene exhibits a notable economy. Inasmuch as the partial saturation of acetylene with any combustible vapour is an operation of extreme simplicity, requiring no power or supervision beyond the occasional recharging of the carburettor, it is manifest that the original main coming from the generator supplying any large establishment where much warming, cooking (or motor driving) might conveniently be done with the gas could be divided within the plant-house, one branch supplying all, or nearly all, the lighting burners with plain acetylene, and the other branch communicating with a carburettor, so that all, or nearly all, the warming and cooking stoves (and the motor) should be supplied with the more economical carburetted acetylene. Since any water pump or similar apparatus would be in an outhouse or basement, and the most important heating stove (the cooker) be in the kitchen, such an arrangement would be neither complicated nor involve a costly duplication of pipes. It follows from the fact that even a trifling proportion of vapour reduces the upper limit of explosibility of mixtures of acetylene with air, that the gas may be so lightly carburetted as not appreciably to suffer in illuminating power when consumed in self-luminous jets, and yet to burn satisfactorily in incandescent burners, even if it has been generated in an apparatus which introduces some air every time the operation of recharging is performed. To carry out this idea, Caro has suggested that 5 kilos. of petroleum spirit should be added to the generator water for every 50 cubic metres of gas evolved, _i.e._, 1 lb. per 160 cubic feet, or, say, 1 gallon per 1000 cubic feet, or per 200 lb. of carbide decomposed. Caro proposed this addition in the case of central installations supplying a district where the majority of the consumers burnt the gas in self-luminous jets, but where a few preferred the incandescent system; but it is clearly equally suitable for employment in all private plants of sufficient magnitude. A lowering of the upper limit of explosibility is also produced by the presence of the acetone which remains in acetylene when obtained from a cylinder holding the compressed gas (_cf._ Chapter XI.). According to Wolff and Caro such gas usually carries with it from 30 to 60 grammes of acetone vapour per cubic metre, _i.e._, 1.27 grammes per cubic foot on an average; and this amount reduces the upper limit of explosibility by about 16 per cent., so that to this extent the gas behaves more smoothly in an incandescent burner of imperfect design. Lépinay has described some experiments on the comparative technical value of ordinary acetylene, carburetted acetylene, denatured alcohol and petroleum spirit as fuels for small explosion engines. One particular motor of 3 (French) h.p. consumed 1150 grammes of petroleum spirit per hour at full load; but when it was supplied with carburetted acetylene its consumption fell to 150 litres of acetylene and 700 grammes of spirit (specific gravity 0.680). A 1-1/4 h.p. engine running light required 48 grammes of 90 per cent. alcohol per horse-power-hour and 66 litres of acetylene; at full load it took 220 grammes of alcohol and 110 litres of acetylene. A 6 h.p. engine at full load required 62 litres of acetylene carburetted with 197 grammes of petroleum spirit per horse-power-hour (uncorrected); while a similar motor fed with low-grade Taylor fuel-gas took 1260 litres per horse-power-hour, but on an average developed the same amount of power from 73 litres when 10 per cent. of acetylene was added to the gas. Lépinay found that with pure acetylene ignition of the charge was apt to be premature; and that while the consumption of carburetted acetylene in small motors still materially exceeded the theoretical, further economics could be attained, which, coupled with the smooth and regular running of an engine fed with the carburetted gas, made carburetted acetylene distinctly the better power-gas of the two. CHAPTER XI COMPRESSED AND DISSOLVED ACETYLENE--MIXTURES WITH OTHER GASES In all that was said in Chapters II., III., IV., and V. respecting the generation and employment of acetylene, it was assumed that the gas would be produced by the interaction of calcium carbide and water, either by the consumer himself, or in some central station delivering the acetylene throughout a neighbourhood in mains. But there are other methods of using the gas, which have now to be considered. COMPRESSED ACETYLENE.--In the first place, like all other gases, acetylene is capable of compression, or even of conversion into the liquid state; for as a gas, the volume occupied by any given weight of it is not fixed, but varies inversely with the pressure under which it is stored. A steel cylinder, for instance, which is of such size as to hold a cubic foot of water, also holds a cubic foot of acetylene at atmospheric pressure, but holds 2 cubic feet if the gas is pumped into it to a pressure of 2 atmospheres, or 30 lb. per square inch; while by increasing the pressure to 21.53 atmospheres at 0° C. (Ansdell, Willson and Suckert) the gas is liquefied, and the vessel may then contain 1 cubic foot of liquid acetylene, which is equal to some 400 cubic feet of gaseous acetylene at normal pressure. It is clear that for many purposes acetylene so compressed or liquefied would be convenient, for if the cylinders could be procured ready charged, all troubles incidental to generation would be avoided. The method, however, is not practically permissible; because, as pointed out in Chapters II. and VI., acetylene does not safely bear compression to a point exceeding 2 atmospheres; and the liability to spontaneous dissociation or explosion in presence of spark or severe blow, which is characteristic of compressed gaseous acetylene, is greatly enhanced if compression has been pushed to the point of liquefaction. However, two methods of retaining the portability and convenience of compressed acetylene with complete safety have been discovered. In one, due to the researches of Claude and Hess, the gas is pumped under pressure into acetone, a combustible organic liquid of high solvent power, which boils at 56° C. As the solvent capacity of most liquids for most gases rises with the pressure, a bottle partly filled with acetone may be charged with acetylene at considerable effective pressure until the vessel contains much more than its normal quantity of gas; and when the valve is opened the surplus escapes, ready for employment, leaving the acetone practically unaltered in composition or quantity, and fit to receive a fresh charge of gas. In comparison with liquefied acetylene, its solution in acetone under pressure is much safer; but since the acetone expands during absorption of gas, the bottle cannot be entirely filled with liquid, and therefore either at first, or during consumption (or both), above the level of the relatively safe solution, the cylinder contains a certain quantity of gaseous acetylene, which is compressed above its limit of safety. The other method consists in pumping acetylene under pressure into a cylinder apparently quite full of some highly porous solid matter, like charcoal, kieselguhr, unglazed brick, &c. This has the practical result that the gas is held under a high state of compression, or possibly as a liquid, in the minute crevices of the material, which are almost of insensible magnitude; or it may be regarded as stored in vessels whose diameter is less than that in which an explosive wave can be propagated (_cf._ Chapter VI.). DISSOLVED ACETYLENE.--According to Fouché, the simple solution of acetylene in acetone has the same coefficient of expansion by heat as that of pure acetone, viz., 0.0015; the corresponding coefficient of liquefied acetylene is 0.007 (Fouché), or 0.00489 (Ansdell) _i.e._, three or five times as much. The specific gravity of liquid acetylene is 0.420 at 16.4° C. (Ansdell), or 0.528 at 20.6° C. (Willson and Suckert); while the density of acetylene dissolved in acetone is 0.71 at 15° C. (Claude). The tension of liquefied acetylene is 21.53 atmospheres at 0° C., and 39.76 atmospheres at 20.15° C. (Ansdell); 21.53 at 0° C., and 39.76 at 19.5° C. (Willson and Suckert); or 26.5 at 0° C., and 42.8 at 20.0° C. (Villard). Averaging those results, it may be said that the tension rises from 23.2 atmospheres at 0° C. to 40.77 at 20° C., which is an increment of 1/26 or 0.88 atmosphere, per 1° Centigrade; while, of course, liquefied acetylene cannot be kept at all at a temperature of 0° unless the pressure is 21 atmospheres or upwards. The solution of acetylene in acetone can be stored at any pressure above or below that of the atmosphere, and the extent to which the pressure will rise as the temperature increases depends on the original pressure. Berthelot and Vieille have shown that when (_a_) 301 grammes of acetone are charged with 69 grammes of acetylene, a pressure of 6.74 atmospheres at 14.0° C. rises to 10.55 atmospheres at 35.7° C.; (_b_) 315 grammes of acetone are charged with 118 grammes of acetylene, a pressure of 12.25 atmospheres at 14.0° C. rises to 19.46 at 36.0° C.; (_c_) 315 grammes of acetone are charged with 203 grammes of acetylene, a pressure of 19.98 atmospheres at 13.0° C. rises to 30.49 at 36.0° C. Therefore in (_a_) the increase in pressure is 0.18 atmosphere, in (_b_) O.33 atmosphere, and in (_c_) 0.46 atmosphere per 1° Centigrade within the temperature limits quoted. Taking case (_b_) as the normal, it follows that the increment in pressure per 1° C. is 1/37 (usually quoted as 1/30); so that, measured as a proportion of the existing pressure, the pressure in a closed vessel containing a solution of acetylene in acetone increases nearly as much (though distinctly less) for a given rise in temperature as does the pressure in a similar vessel filled with liquefied acetylene, but the absolute increase is roughly only one-third with the solution as with the liquid, because the initial pressure under which the solution is stored is only one-half, or less, that at which the liquefied gas must exist. Supposing, now, that acetylene contained in a closed vessel, either as compressed gas, as a solution in acetone, or as a liquid, were brought to explosion by spark or shock, the effects capable of production have to be considered. Berthelot and Vieille have shown that if gaseous acetylene is stored at a pressure of 11.23 kilogrammes per square centimetre, [Footnote: 1 kilo. per sq. cm. is almost identical with 1 atmosphere, or 15 lb. per sq. inch.] the pressure after explosion reaches 92.33 atmospheres on an average, which is an increase of 8.37 times the original figure; if the gas is stored at 21.13 atmospheres, the mean pressure after explosion is 213.15 atmospheres, or 10.13 times the original amount. If liquid acetylene is tested similarly, the original pressure, which must clearly be more than 21.53 atmospheres (Ansdell) at 0° C., may rise to 5564 kilos, per square centimetre, as Berthelot and Vieille observed when a steel bomb having a capacity of 49 c.c. was charged with 18 grammes of liquefied acetylene. In the case of the solution in acetone, the magnitudes of the pressures set up are of two entirely different orders according as the original pressure 20 atmospheres or somewhat less; but apart from this, they vary considerably with the extent to which the vessel is filled with the liquid, and they also depend on whether the explosion is produced in the solution or in the gas space above. Taking the lower original pressure first, viz., 10 atmospheres, when a vessel was filled with solution to 33 per cent. of its capacity, the pressure after explosion reached about 95 atmospheres if the spark was applied to the gas space; but attained 117.4 atmospheres when the spark was applied to the acetone. When the vessel was filled 56 per cent. full, the pressures after explosion reached about 89, or 155 atmospheres, according as the gas or the liquid was treated with the spark. But when the original pressure was 20 atmospheres, and the vessel was filled to 35 per cent. of its actual capacity with solution, the final pressures ranged from 303 to 568 atmospheres when the gas was fired, and from 2000 to 5100 when the spark was applied to the acetone. Examining these figures carefully, it will be seen that the phenomena accompanying the explosion of a solution of acetylene in acetone resemble those of the explosion of compressed gaseous acetylene when the original pressure under which the solution is stored is about 10 atmospheres; but resemble those of the explosion of liquefied acetylene when the original pressure of the solution reaches 20 atmospheres, this being due to the fact that at an original pressure of 10 atmospheres the acetone itself does not explode, but, being exothermic, rather tends to decrease the severity of the explosion; whereas at an original pressure of 20 atmospheres the acetone does explode (or burn), and adds its heat of combustion to the heat evolved by the acetylene. Thus at 10 atmospheres the presence of the acetone is a source of safety; but at 20 atmospheres it becomes an extra danger. Since sound steel cylinders may easily be constructed to boar a pressure of 250 atmospheres, but would be burst by a pressure considerably less than 5000 atmospheres, it appears that liquefied acetylene and its solution in acetone at a pressure of 20 atmospheres are quite unsafe; and it might also seem that both the solution at a pressure of 10 atmospheres and the simple gas compressed to the same limit should be safe. But there is an important difference here, in degree if not in kind, because, given a cylinder of known capacity containing (1) gaseous acetylene compressed to 10 atmospheres, or (2) containing the solution at the same pressure, if an explosion were to occur, in case (1) the whole contents would participate in the decomposition, whereas in case (2), as mentioned already, only the small quantity of gaseous acetylene above the solution would be dissociated. It is manifest that of the three varieties of compressed acetylene now under consideration, the solution in acetone is the only one fit for general employment; but it exhibits the grave defects (_a_) that the pressure under which it is prepared must be so small that the pressure in the cylinders can never approach 20 atmospheres in the hottest weather or in the hottest situation to which they may be exposed, (_b_) that the gas does not escape smoothly enough to be convenient from large vessels unless those vessels are agitated, and (_c_) that the cylinders must always be used in a certain position with the valve at the top, lest part of the liquid should run out into the pipes. For these reasons the simple solution of acetylene in acetone has not become of industrial importance; but the processes of absorbing either the gas, or better still its solution in acetone, in porous matter have already achieved considerable success. Both methods have proved perfectly safe and trustworthy; but the combination of the acetone process with the porous matter makes the cylinders smaller per unit volume of acetylene they contain. Several varieties of solid matter appear to work satisfactorily, the only essential feature in their composition being that they shall possess a proper amount of porosity and be perfectly free from action upon the acetylene or the acetone (if present). Lime does attack acetone in time, and therefore it is not a suitable ingredient of the solid substance whenever acetylene is to be compressed in conjunction with the solvent; so that at present either a light brick earth which has a specific gravity of 0.5 is employed, or a mixture of charcoal with certain inorganic salts which has a density of 0.3, and can be introduced through a small aperture into the cylinder in a semi-fluid condition. Both materials possess a porosity of 80 per cent., that is to say, when a cylinder is apparently filled quite full, only 20 per cent, of the space is really occupied by the solid body, the remaining 80 per cent, being available for holding the liquid or the compressed gas. If all comparisons as to degree of explosibility and effects of explosion are omitted, an analogy may be drawn between liquefied acetylene or its compressed solution in acetone and nitroglycerin, while the gas or solution of the gas absorbed in porous matter resembles dynamite. Nitroglycerin is almost too treacherous a material to handle, but as an explosive (which in reason absorbed or dissolved acetylene is not) dynamite is safe, and even requires special arrangements to explode it. In Paris, where the acetone process first found employment on a large scale, the company supplying portable cylinders to consumers uses large storage vessels filled, as above mentioned, apparently full of porous solid matter, and also charged to about 43 per cent, of their capacity with acetone, thus leaving about 37 per cent. of the apace for the expansion which occurs as the liquid takes up the gas. Acetylene is generated, purified, and thoroughly dried according to the usual methods; and it is then run through a double-action pump which compresses it first to a pressure of 3.5 kilos., next to a pressure of 3.5 x 3.5 = 12 kilos, per square centimetre, and finally drives it into the storage vessels. Compression is effected in two stages, because the process is accompanied by an evolution of much heat, which might cause the gas to explode during the operation; but since the pump is fitted with two cylinders, the acetylene can be cooled after the first compression. The storage vessels then contain 100 times their apparent volume of acetylene; for as the solubility of acetylene in acetone at ordinary temperature and pressure is about 25 volumes of gas in 1 of liquid, a vessel holding 100 volumes when empty takes up 25 x 43 = 1000 volumes of acetylene roughly at atmospheric pressure; which, as the pressure is approximately 10 atmospheres, becomes 1000 x 10 = 10,000 volumes per 100 normal capacity, or 100 times the capacity of the vessel in terms of water. From these large vessels, portable cylinders of various useful dimensions, similarly loaded with porous matter and acetone, are charged simply by placing them in mutual contact, thus allowing the pressure and the surplus gas to enter the small one; a process which has the advantage of renewing the small quantity of acetone vaporised from the consumers' cylinders as the acetylene is burnt (for acetone is somewhat volatile, cf. Chapter X.), so that only the storage vessels ever need to have fresh solvent introduced. Where it is procurable, the use of acetylene compressed in this fashion is simplicity itself; for the cylinders have only to be connected with the house service-pipes through a reducing valve of ordinary construction, set to give the pressure which the burners require. When exhausted, the bottle is simply replaced by another. Manifestly, however, the cost of compression, the interest on the value of the cylinders, and the carriage, &c., make the compressed gas more expensive per unit of volume (or light) than acetylene locally generated from carbide and water; and indeed the value of the process does not lie so much in the direction of domestic illumination as in that of the lighting, and possibly driving, of vehicles and motor-cars--more especially in the illumination of such vehicles as travel constantly, or for business purposes, over rough road surfaces and perform mostly out-and-home journeys. Nevertheless, absorbed acetylene may claim close attention for one department of household illumination, viz., the portable table-lamp; for the base of such an apparatus might easily be constructed to imitate the acetone cylinder, and it could be charged by simple connexion with a larger one at intervals. In this way the size of the lamp for a given number of candle-hours would be reduced below that of any type of actual generator, and the troubles of after-generation, always more or less experienced in holderless generators, would be entirely done away with. Dissolved acetylene is also very useful for acetylene welding or autogenous soldering. The advantages of compressed and absorbed acetylene depend on the small bulk and weight of the apparatus per unit of light, on the fact that no amount of agitation can affect the evolution of gas (as may happen with an ordinary acetylene generator), on the absence of any liquid which may freeze in winter, and on there being no need for skilled attention except when the cylinders are being changed. These vessels weigh between 2.5 and 3 kilos, per 1 litre capacity (normal) and since they are charged with 100 times their apparent volume of acetylene, they may be said to weigh 1 kilo, per 33 litres of available acetylene, or roughly 2 lb. per cubic foot, or, again, if half-foot burners are used, 2 lb. per 36 candle- hours. According to Fouché, if electricity obtained from lead accumulators is compared with acetylene on the basis of the weight of apparatus needed to evolve a certain quantify of light, 1 kilo, of acetylene cylinder is equal to 1.33 kilos, of lead accumulator with arc lamps, or to 4 kilos. of accumulator with glow lamps; and moreover the acetylene cylinder can be charged and discharged, broadly speaking, as quickly or as slowly as may be desired; while, it may be added, the same cylinder will serve one or more self-luminous jets, one or more incandescent burners, any number and variety of heating apparatus, simultaneously or consecutively, at any pressure which may be required. From the aspect of space occupied, dissolved acetylene is not so concentrated a source of artificial light as calcium carbide; for 1 volume of granulated carbide is capable of omitting as much light as 4 volumes of compressed gas; although, in practice, to the 1 volume of carbide must be added that of the apparatus in which it is decomposed. LIQUEFIED ACETYLENE.--In most civilised countries the importation, manufacture, storage, and use of liquefied acetylene, or of the gas compressed to more than a fraction of one effective atmosphere, is quite properly prohibited by law. In Great Britain this has been done by an Order in Council dated November 26, 1897, which specifies 100 inches of water column as the maximum to which compression may be pushed. Power being retained, however, to exempt from the order any method of compressing acetylene that might be proved safe, the Home Secretary issued a subsequent Order on March 28, 1898, permitting oil-gas containing not more than 20 per cent, by volume of acetylene (see below) to be compressed to a degree not exceeding 150 lb. per square inch, _i.e._, to about 10 atmospheres, provided the gases are mixed together before compression; while a third Order, dated April 10, 1901, allows the compression of acetylene into cylinders filled as completely as possible with porous matter, with or without the presence of acetone, to a pressure not exceeding 150 lb. per square inch provided the cylinders themselves have been tested by hydraulic pressure for at least ten minutes to a pressure not less than double [Footnote: In France the cylinders are tested to six times and in Russia to five times their working pressure.] that which it is intended to use, provided the solid substance is similar in every respect to the samples deposited at the Home Office, provided its porosity does not exceed 80 per cent., provided air is excluded from every part of the apparatus before the gas is compressed, provided the quantity of acetone used (if used at all) is not sufficient to fill the porosity of the solid, provided the temperature is not permitted to rise during compression, and provided compression only takes place in premises approved by H.M.'s Inspectors of Explosives. DILUTED ACETYLENE.--Acetylene is naturally capable of admixture or dilution with any other gas or vapour; and the operation may be regarded in either of two ways; (1) as a, means of improving the burning qualities of the acetylene itself, or (2) as a means of conferring upon some other gas increased luminosity. In the early days of the acetylene industry, generation was performed in so haphazard a fashion, purification so generally omitted, and the burners were so inefficient, that it was proposed to add to the gas a comparatively small proportion of some other gaseous fluid which should be capable of making it burn without deposition of carbon while not seriously impairing its latent illuminating power. One of the first diluents suggested was carbon dioxide (carbonic acid gas), because this gas is very easy and cheap to prepare; and because it was stated that acetylene would bear an addition of 5 or even 8 per cent, of carbon dioxide and yet develop its full degree of luminosity. This last assertion requires substantiation; for it is at least a grave theoretical error to add a non-inflammable gas to a combustible one, as is seen in the lower efficiency of all flames when burning in common air in comparison with that which they exhibit in oxygen; while from the practical aspect, so harmful is carbon dioxide in an illuminating gas, that coal-gas and carburetted water-gas are frequently most rigorously freed from it, because a certain gain in illuminating power may often thus be achieved more cheaply than by direct enrichment of the gas by addition of hydrocarbons. Being prepared from chalk and any cheap mineral acid, hydrochloric by preference, in the cold, carbon dioxide is so cheap that its price in comparison with that of acetylene is almost _nil_; and therefore, on the above assumption, 105 volumes of diluted acetylene might be made essentially for the same price as 100 volumes of neat acetylene, and according to supposition emit 5 per cent. more light per unit of volume. It is reported that several railway trains in Austria are regularly lighted with acetylene containing 0.4 to 1.0 per cent. of carbon dioxide in order to prevent deposition of carbon at the burners. The gas is prepared according to a patent process which consists in adding a certain proportion of a "carbonate" to the generator water. In the United Kingdom, also, there are several installations supplying an acetylene diluted with carbon dioxide, the gas being produced by putting into that portion of a water-to-carbide generator which lies nearest to the water- supply some solid carbonate like chalk, and using a dilute acid to attack the material. Other inventors have proposed placing a solid acid, like oxalic, in the former part of a generator and decomposing it with a carbonate solution; or they have suggested putting into the generator a mixture of a solid acid and a solid soluble carbonate, and decomposing it with plain water. Clearly, unless the apparatus in which such mixtures as these are intended to be prepared is designed with considerable care, the amount of carbon dioxide in the gas will be liable to vary, and may fall to zero. If any quantity of carbide present has been decomposed in the ordinary way, there will be free calcium hydroxide in the generator; and if the carbon dioxide comes into contact with this, it will be absorbed, unless sufficient acid is employed to convert the calcium carbonate (or hydroxide) into the corresponding normal salt of calcium. Similarly, during purification, a material containing any free lime would tend to remove the carbon dioxide, as would any substance which became alkaline by retaining the ammonia of the crude gas. It cannot altogether be granted that the value of a process for diluting acetylene with carbon dioxide has been established, except in so far as the mere presence of the diluent may somewhat diminish the tendency of the acetylene to polymerise as it passes through a hot burner (_cf._ Chapter VIII.). Certainly as a fuel-gas the mixture would be less efficient, and the extra amount of carbon dioxide produced by each flame is not wholly to be ignored. Moreover, since properly generated and purified acetylene can be consumed in proper burners without trouble, all reason for introducing carbon dioxide has disappeared. MIXTURES OF ACETYLENE AND AIR.--A further proposal for diluting acetylene was the addition to it of air. Apart from questions of explosibility, this method has the advantage over that of adding carbon dioxide that the air, though not inflammable, is, in virtue of its contained oxygen, a supporter of combustion, and is required in a flame; whereas carbon dioxide is not only not a supporter of combustion, but is actually a product thereof, and correspondingly more objectionable. According to some experiments carried out by Dufour, neat acetylene burnt under certain conditions evolved between 1.0 and 1.8 candle-power per litre- hour; a mixture of 1 volume of acetylene with 1 volume of air evolved 1.4 candle-power; a mixture of 1 volume of acetylene with 1.2 volumes of air, 2.25 candle-power; and a mixture of 1 volume of acetylene with 1.3 volumes of air, 2.70 candle-power per litre-hour of acetylene in the several mixtures. Averaging the figures, and calculating into terms of acetylene (only) burnt, Dufour found neat acetylene to develop 1.29 candle-power per litre-hour, and acetylene diluted with air to develop 1.51 candle-power. When, however, allowance is made for the cost and trouble of preparing such mixtures the advantage of the process disappears; and moreover it is accompanied by too grave risks, unless conducted on a largo scale and under most highly skilled supervision, to be fit for general employment. Fouché, however, has since found the duty, per cubic foot of neat acetylene consumed in a twin injector burner at the most advantageous rate of 3.2 inches, to be as follows for mixtures with air in the proportions stated: Percentage of air 0 17 27 33.5 Candles per cubic feet 38.4 36.0 32.8 26.0 At lower pressures, the duty of the acetylene when diluted appears to be relatively somewhat higher. Figures which have been published in regard to a mixture of 30 volumes of air and 70 volumes of acetylene obtained by a particular system of producing such a mixture, known as the "Molet- Boistelle," indicate that the admixture of air causes a slight increase in the illuminating duty obtained from the acetylene in burners of various sizes. The type of burner and the pressure employed in these experiments were not, however, stated. This system has been used at certain stations on the "Midi" railway in France. Nevertheless even where the admixture of air to acetylene is legally permissible, the risk of obtaining a really dangerous product and the nebulous character of the advantages attainable should preclude its adoption. In Great Britain the manufacture, importation, storage, and use of acetylene mixed with air or oxygen, in all proportions and at all pressures, with or without the presence of other substances, is prohibited by an Order in Council dated July 1900; to which prohibition the mixture of acetylene and air that takes place in a burner or contrivance in which the mixture is intended to be burnt, and the admixture of air with acetylene that may unavoidably occur in the first use or recharging of an apparatus (usually a water-to-carbide generator), properly designed and constructed with a view to the production of pure acetylene, are the solitary exceptions. MIXED CARBIDES.--In fact the only processes for diluting acetylene which possess real utility are that of adding vaporised petroleum spirit or benzene to the gas, as was described in Chapter X. under the name of carburetted acetylene, and one other possible method of obtaining a diluted acetylene directly from the gas-generator, to which a few words will now be devoted. [Footnote: Mixtures of acetylene with relatively large proportions of other illuminating gases, such as are referred to on subsequent pages, are also, from one aspect, forms of diluted acetylene.] Calcium carbide is only one particular specimen of a large number of similar metallic compounds, which can be prepared in the electric furnace, or otherwise. Some of those carbides yield acetylene when treated with water, some are not attacked, some give liquid products, and some yield methane, or mixtures of methane and hydrogen. Among the latter is manganese carbide. If, then, a mixture of manganese carbide and calcium carbide is put into an ordinary acetylene generator, the gas evolved will be a mixture of acetylene with methane and hydrogen in proportions depending upon the composition of the carbide mixture. It is clear that a suitable mixture of the carbides might be made by preparing them separately and bulking the whole in the desired proportions; while since manganese carbide can be won in the electric furnace, it might be feasible to charge into such a furnace a mixture of lime, coke, and manganese oxide calculated to yield a simple mixture of the carbides or a kind of double carbide. Following the lines which have been adopted in writing the present book, it is not proposed to discuss the possibility of making mixed carbides; but it may be said in brief that Brame and Lewes have carried out several experiments in this direction, using charges of lime and coke containing (_a_) up to 20 per cent. of manganese oxide, and (_b_) more than 60 per cent. of manganese oxide. In neither case did they succeed in obtaining a material which gave a mixture of acetylene and methane when treated with water; in case (_a_) they found the gas to be practically pure acetylene, so that the carbide must have been calcium carbide only; in case (_b_) the gas was mainly methane and hydrogen, so that the carbide must have been essentially that of manganese alone. Mixed charges containing between 20 and 60 per cent. of manganese oxide remain to be studied; but whether they would give mixed carbides or no, it would be perfectly simple to mix ready-made carbides of calcium and manganese together, if any demand for a diluted acetylene should arise on a sufficiently large scale. It is, however, somewhat difficult to appreciate the benefits to be obtained from forms of diluted acetylene other than those to which reference is made later in this chapter. There is, nevertheless, one modification of calcium carbide which, in a small but important sphere, finds a useful _rôle_. It has been pointed out that a carbide containing much calcium phosphide is usually objectionable, because the gas evolved from it requires extra purification, and because there is the (somewhat unlikely) possibility that the acetylene obtained from such material before purification may be spontaneously inflammable. If, now, to the usual furnace charge of lime and coke a sufficient quantity of calcium phosphate is purposely added, it is possible to win a mixture of calcium phosphide and carbide, or, as Bradley, Read, and Jacobs call it, a "carbophosphide of calcium," having the formula Ca_5C_6P_2, which yields a spontaneously inflammable mixture of acetylene, gaseous phosphine, and liquid phosphine when treated with water, and which, therefore, automatically gives a flame when brought into contact with the liquid. The value of this material will be described in Chapter XIII. GAS-ENRICHING.--Other methods of diluting acetylene consist in adding a comparatively small proportion of it to some other gas, and may be considered rather as processes for enriching that other gas with acetylene. Provided the second gas is well chosen, such mixtures exhibit properties which render them peculiarly valuable for special purposes. They have, usually, a far lower upper limit of explosibility than that of neat acetylene, and they admit of safe compression to an extent greatly exceeding that of acetylene itself, while they do not lose illuminating power on compression. The second characteristic is most important, and depends on the phenomena of "partial pressure," which have been referred to in Chapter VI. When a single gas is stored at atmospheric pressure, it is insensibly withstanding on all sides and in all directions a pressure of roughly 15 lb. per square inch, which is the weight of the atmosphere at sea-level; and when a mixture of two gases, X and Y, in equal volumes is similarly stored it, regarded as an entity, is also supporting a pressure of 15 lb. per square inch. But in every 1 volume of that mixture there is only half a volume of X and Y each; and, ignoring the presence of its partner, each half-volume is evenly distributed throughout a space of 1 volume. But since the volume of a gas stands in inverse ratio to the pressure under which it is stored, the half-volume of X in the 1 volume of X + Y apparently stands at a pressure of half an atmosphere, for it has expanded till it fills, from a chemical and physical aspect, the space of 1 volume: suitable tests proving that it exhibits the properties which a gas stored at a pressure of half an atmosphere should do. Therefore, in the mixture under consideration, X and Y are both said to be at a "partial pressure" of half an atmosphere, which is manifestly 7.5 lb. per square inch. Clearly, when a gas is an entity (either an element or one single chemical compound) partial and total pressure are identical. Now, it has been shown that acetylene ceases to be a safe gas to handle when it is stored at a pressure of 2 atmospheres; but the limit of safety really occurs when the gas is stored at a _partial_ pressure of 2 atmospheres. Neat acetylene, accordingly, cannot be compressed above the mark 30 lb. shown on a pressure gauge; but diluted acetylene (if the diluent is suitable) may be compressed in safety till the partial pressure of the acetylene itself reaches 2 atmospheres. For instance, a mixture of equal volumes of X and Y (X being acetylene) contains X at a partial pressure of half the total pressure, and may therefore be compressed to (2 / 1/2 =) 4 atmospheres before X reaches the partial pressure of 2 atmospheres; and therewith the mixture is brought just to the limit of safety, any effect of Y one way or the other being neglected. Similarly, a mixture of 1 volume of acetylene with 4 volumes of Y may be safely compressed to a pressure of (2 / 1/5 =) 10 atmospheres, or, broadly, a mixture in which the percentage of acetylene is _x_ may be safely compressed to a pressure not exceeding (2 / _x_/100) atmospheres. This fact permits acetylene after proper dilution to be compressed in the same fashion as is allowable in the case of the dissolved and absorbed gas described above. If the latent illuminating power of acetylene is not to be wasted, the diluent must not be selected without thought. Acetylene burns with a very hot flame, the luminosity of which is seriously decreased if the temperature is lowered. As mentioned in Chapter VIII., this may be done by allowing too much air to enter the flame; but it may also be effected to a certain extent by mixing with the acetylene before combustion some combustible gas or vapour which burns at a lower temperature than acetylene itself. Manifestly, therefore, the ideal diluent for acetylene is a substance which possesses as high a flame temperature as acetylene and a certain degree of intrinsic illuminating power, while the lower the flame temperature of the diluent and the less its intrinsic illuminating power, the less efficiently will the acetylene act as an enriching material. According to Love, Hempel, Wedding, and others, if acetylene is mixed with coal-gas in amounts up to 8 per cent. or thereabouts, the illuminating power of the mixture increases about 1 candle for every 1 per cent. of acetylene present: a fact which is usually expressed by saying that with coal-gas the enrichment value of acetylene is 1 candle per 1 per cent. Above 8 per cent., the enrichment value of acetylene rises, Love having found an increase in illuminating power, for each 1 per cent. of acetylene in the mixture, of 1.42 candles with 11.28 per cent. of acetylene; and of 1.54 candles with 17.62 per cent. of acetylene. Theoretically, if the illuminating power of acetylene is taken at 240 candles, its enrichment value should be (240 / 100 =) 2.4 candles per 1 per cent.; and since, in the case of coal-gas, its actual enrichment value falls seriously below this figure, it is clear that coal-gas is not an economical diluent for it. Moreover, coal-gas can be enriched by other methods much more cheaply than with acetylene. Simple ("blue") water-gas, according to Love, requires more than 10 per cent. of acetylene to be added to it before a luminous flame is produced; while a mixture of 20.3 per cent. of acetylene and 79.7 per cent. of water-gas had an illuminating power of 15.47 candles. Every addition to the proportion of acetylene when it amounted to 20 per cent. and upwards of the mixture had a very appreciable effect on the illuminating power of the latter. Thus with 27.84 per cent. of acetylene, the illuminating power of the mixture was 40.87 candles; with 38.00 per cent. of acetylene it was 73.96 candles. Acetylene would not be an economical agent to employ in order to render water-gas an illuminating gas of about the quality of coal-gas, but the economy of enrichment of water-gas by acetylene increases rapidly with the degree of enrichment demanded of it. Carburetted water-gas which, after compression under 16 atmospheres pressure, had an illuminating power of about 17.5 candles, was enriched by additions of acetylene. 4.5 per cent. of acetylene in the mixture gave an illuminating power of 22.69 candles; 8.4 per cent., 29.54 candles; 11.21 per cent., 35.05 candles; 15.06 per cent., 42.19 candles; and 21.44 per cent., 52.61 candles. It is therefore evident that the effect of additions of acetylene on the illuminating power of carburetted water-gas is of the same order as its effect on coal-gas. The enrichment value of the acetylene increases with its proportion in the mixture; but only when the proportion becomes quite considerable, and, therefore, the gas of high illuminating power, does enrichment by acetylene become economical. Methane (marsh-gas), owing to its comparatively high flame temperature, and to the fact that it has an intrinsic, if small, illuminating power, is a better diluent of acetylene than carbon monoxide or hydrogen, in that it preserves to a greater extent the illuminative value of the acetylene. Actually comparisons of the effect of additions of various proportions of a richly illuminating gas, such as acetylene, on the illuminative value of a gas which has little or no inherent illuminating power, are largely vitiated by the want of any systematic method for arriving at the representative illuminative value of any illuminating gas. A statement that the illuminating power of a gas is _x_ candles is, strictly speaking, incomplete, unless it is supplemented by the information that the gas during testing was burnt (1) in a specified type of burner, and (2) either at a specified fixed rate of consumption or so as to afford a light of a certain specified intensity. There is no general agreement, even in respect of the statutory testing of the illuminating power of coal-gas supplies, as to the observance of uniform conditions of burning of the gas under test, and in regard to more highly illuminating gases there is even greater diversity of conditions. Hence figures such as those quoted above for the enrichment value of acetylene inevitably show a certain want of harmony which is in reality due to the imperfection or incompleteness of the modes of testing employed. Relatively to another, one gas appears advantageously merely in virtue of the conditions of assessing illuminating power having been more favourable to it. Therefore enrichment values, such as those given, must always be regarded as only approximately trustworthy in instituting comparisons between either different diluent gases or different enriching agents. ACETYLENE MIXTURES FOR RAILWAY-CARRIAGE LIGHTING.--In modern practice, the gases which are most commonly employed for diluents of acetylene, under the conditions now being considered, are cannel-coal gas (in France) and oil-gas (elsewhere). Fowler has made a series of observations on the illuminating value of mixtures of oil-gas and acetylene. 13.41 per cent. of acetylene improved the illuminating power of oil-gas from 43 to 49 candles. Thirty-nine-candle-power oil-gas had its illuminating power raised to about 60 candles by an admixture of 20 per cent. of acetylene, to about 80 candles by 40 per cent. of acetylene, and to about 110 candles by 60 per cent. of acetylene. The difficulty of employing mixtures fairly rich in acetylene, or pure acetylene, for railway- carriage lighting, lies in the poor efficiency of the small burners which yield from such rich gas a light of 15 to 20 candle-power, such as is suitable for the purpose. For the lighting of railway carriages it is seldom deemed necessary to have a flame of more than 20 candle-power, and it is somewhat difficult to obtain such a flame from oil-gas mixtures rich in acetylene, unless the illuminative value of the gas is wasted to a considerable extent. According to Bunte, 15 volumes of coal-gas, 8 volumes of German oil-gas, and 1.5 volumes of acetylene all yield an equal amount of light; from which it follows that 1 volume of acetylene is equivalent to 5.3 volumes of German oil-gas. A lengthy series of experiments upon the illuminating power of mixtures of oil-gas and acetylene in proportions ranging between 10 and 50 per cent. of the latter, consumed in different burners and at different pressures, has been carried out by Borck, of the German State Railway Department. The figures show that per unit of volume such mixtures may give anything up to 6.75 times the light evolved by pure oil-gas; but that the latent illuminating power of the acetylene is less advantageously developed if too much of it is employed. As 20 per cent. of acetylene is the highest proportion which may be legally added to oil- gas in this country, Borck's results for that mixture may be studied: ______________________________________________________________________ | | | | | | | | | | | | | | | Propor- | | | | | Consump- | | Consump- | tionate | | Kind of | No. of | Pres- | tion per | Candle- | tion per | Illum- | | Burner. | Burner | sure. | Hour. | Power. | Candle- | inating | | | | mm. | Litres. | | Hour. | Power | | | | | | | Litres. | to Pure | | | | | | | | Oil-Gas.| |___________|________|_______|__________|_________|__________|_________| | | | | | | | | | Bray | 00 | 42 | 82 | 56.2 | 1.15 | 3.38 | | " | 000 | 35 | 54 | 28.3 | 1.91 | 4.92 | | " | 0000 | 35 | 43.3 | 16 | 2.71 | 4.90 | | Oil-gas | | | | | | | | burner | 15 | 24 | 21 | 7.25 | 2.89 | 4.53 | | " " | 30 | 15 | 22 | 10.5 | 2.09 | 3.57 | | " " | 40 | 16 | 33.5 | 20.2 | 1.65 | 3.01 | | " " | 60 | 33 | 73 | 45.2 | 1.62 | 3.37 | | | | The oil-gas from which this mixture was prepared showing: | | | | Bray | 00 | 34 | 73.5 | 16.6 | 4.42 | ... | | " | 000 | 30 | 48 | 6.89 | 6.96 | ... | | " | 0000 | 28 | 39 | 3.26 | 11.6 | ... | | Oil-gas | | | | | | | | burner | 15 | 21 | 19 | 1.6 | 11.8 | ... | | " " | 30 | 14 | 21.5 | 2.94 | 7.31 | ... | | " " | 40 | 15 | 33 | 6.7 | 4.92 | ... | | " " | 60 | 25 | 60 | 13.4 | 4.40 | ... | |___________|________|_______|__________|_________|__________|_________| It will be seen that the original oil-gas, when compressed to 10 atmospheres, gave a light of 1 candle-hour for an average consumption of 7.66 litres in the Bray burners, and for a consumption of 7.11 litres in the ordinary German oil-gas jets; while the mixture containing 20 per cent. of acetylene evolved the same amount of light for a consumption of 2.02 litres in Bray burners, or of 2.06 litres in the oil-gas jets. Again, taking No. 40 as the most popular and useful size of burner, 1 volume of acetylene oil-gas may be said to be equal to 3 volumes of simple oil-gas, which is the value assigned to the mixture by the German Government officials, who, at the prices ruling there, hold the mixture to be twice as expensive as plain oil-gas per unit of volume, which means that for a given outlay 50 per cent. more light may be obtained from acetylene oil-gas than from oil-gas alone. This comparison of cost is not applicable, as it stands, to compressed oil-gas, with and without enrichment by acetylene, in this country, owing to the oils from which oil-gas is made being much cheaper and of better quality here than in Germany, where a heavy duty is imposed on imported petroleum. Oil-gas as made from Scotch and other good quality gas-oil in this country, usually has, after compression, an illuminating duty of about 8 candles per cubic foot, which is about double that of the compressed German oil-gas as examined by Borck. Hence the following table, containing a summary of results obtained by H. Fowler with compressed oil-gas, as used on English railways, must be accepted rather than the foregoing, in so far as conditions prevailing in this country are concerned. It likewise refers to a mixture of oil-gas and acetylene containing 20 per cent. of acetylene. ______________________________________________________________________ | | | | | | | | | | | | | Ratio of | | | |Consumption| |Candles per| Illuminating | | Burner. |Pressure.| per Hour. |Candle| Cubic Foot| Power to that | | | Inches. |Cubic Feet.|Power.| per Hour. |of Oil-gas [1] | | | | | | | in the same | | | | | | | Burner. | |_____________|_________|___________|______|___________|_______________| | | | | | | | | Oil-gas . . | 0.7 | 0.98 | 12.5 | 12.72 | 1.65 | | Bray 000 . | 0.7 | 1.17 | 14.4 | 12.30 | 1.57 | | " 0000 . | 0.7 | 0.97 | 10.4 | 10.74 | 1.41 | | " 00000 | 0.7 | 0.78 | 5.6 | 7.16 | 1.08 | | " 000000 | 0.7 | 0.55 | 1.9 | 3.52 | 1.14 | |_____________|_________|___________|______|___________|_______________| [Footnote 1: Data relating to the relative pecuniary values of acetylene (carburetted or not), coal-gas, paraffin, and electricity as heating or illuminating agents, are frequently presented to British readers after simple recalculation into English equivalents of the figures which obtain in France and Germany. Such a method of procedure is utterly incorrect, as it ignores the higher prices of coal, coal-gas, and especially petroleum products on the Continent of Europe, which arise partly from geographical, but mainly from political causes.] The mixture was tried also at higher pressures in the same burners, but with less favourable results in regard to the duty realised. The oil-gas was also tried at various pressures, and the most favourable result is taken for computing the ratio in the last column. It is evident from this table that 1 volume of this acetylene-oil-gas mixture is equal at the most to 1.65 volume of the simple oil-gas. Whether the mixture will prove cheaper under particular conditions must depend on the relative prices of gas-oil and calcium carbide at the works where the gas is made and compressed. At the prevailing prices in most parts of Britain, simple oil-gas is slightly cheaper, but an appreciable rise in the price of gas- oil would render the mixture with acetylene the cheaper illuminant. The fact remains, however, that per unit weight or volume of cylinder into which the gas is compressed, acetylene oil-gas evolves a higher candle- power, or the same candle-power for a longer period, than simple, unenriched British oil-gas. Latterly, however, the incandescent mantle has found application for railway-carriage lighting, and poorer compressed gases have thereby been rendered available. Thus coal-gas, to which a small proportion of acetylene has been added, may advantageously displace the richer oil-gas and acetylene mixtures. Patents have been taken out by Schwander for the preparation of a mixture of acetylene, air, and vaporised petroleum spirit. A current of naturally damp, or artificially moistened, air is led over or through a mass of calcium carbide, whereby the moisture is replaced by an equivalent quantity of acetylene; and this mixture of acetylene and air is carburetted by passing it through a vessel of petroleum spirit in the manner adopted with air-gas. No details as to the composition, illuminating power, and calorific values of the gas so made have been published. It would clearly tend to be of highly indefinite constitution and might range between what would be virtually inferior carburetted acetylene, and a low-grade air-gas. It is also doubtful whether the combustion of such gas would not be accompanied by too grave risks to render the process useful. CHAPTER XII SUNDRY USES There are sundry uses for acetylene, and to some extent for carbide, which are not included in what has been said in previous chapters of this book; and to them a few words may be devoted. In orchards and market gardens enormous damage is frequently done to the crops by the ravages of caterpillars of numerous species. These caterpillars cannot be caught by hand, and hitherto it has proved exceedingly difficult to cope with them. However, when they have changed into the perfect state, the corresponding butterflies and moths, like most other winged insects, are strongly attracted by a bright light. As acetylene can easily be burnt in a portable apparatus, and as the burners can be supplied with gas at such comparatively high pressure that the flames are capable of withstanding sharp gusts of wind even when not protected by glass, the brilliant light given by acetylene forms an excellent method of destroying the insects before they have had time to lay their eggs. Two methods of using the light have been tried with astonishing success: in one a naked flame is supported within some receptacle, such as a barrel with one end knocked out, the interior of which is painted heavily with treacle; in the other the flame is supported over an open dish filled with some cheap heavy oil (or perhaps treacle would do equally well). In the first case the insects are attracted by the light and are caught by the adhesive surfaces; in the second they are attracted and singed, and then drowned in, or caught by, the liquid. Either a well-made, powerful, vehicular lamp with its bull's- eye (if any) removed could be used for this purpose, or a portable generator of any kind might be connected with the burner through a flexible tube. It is necessary that the lights should be lit just before dusk when the weather is fine and the nights dark, and for some twenty evenings in June or July, exactly at the period of the year when the perfect insects are coming into existence. In some of the vineyards of Beaujolais, in France, where great havoc has been wrought by the pyralid, a set of 10-candle-power lamps were put up during July 1901, at distances of 150 yards apart, using generators containing 6 oz. of carbide, and dishes filled with water and petroleum 18 or 20 inches in diameter. In eighteen nights, some twenty lamps being employed, the total catch of insects was 170,000, or an average of 3200 per lamp per night. At French prices, the cost is reported to have been 8 centimes per night, or 32 centimes per hectare (2.5 acres). In Germany, where school children are occasionally paid for destroying noxious moths, two acetylene lamps burning for twelve evenings succeeded in catching twice as many insects as the whole juvenile population of a village during August 1902. A similar process has been recommended for the destruction of the malarial mosquito, and should prove of great service to mankind in infected districts. The superiority of acetylene in respect of brilliancy and portability will at once suggest its employment as the illuminant in the "light" moth-traps which entomologists use for entrapping moths. In these traps, the insects, attracted by the light, flutter down panes of glass, so inclined that ultimate escape is improbable; while they are protected from injury through contact with the flame by moans of an intervening sheet of glass. Methods of spraying with carbide dust have been found useful in treating mildew in vines; while a process of burying small quantities of carbide at the roots has proved highly efficacious in exterminating phylloxera in the French and Spanish vineyards. It was originally believed that the impurities of the slowly formed acetylene, the phosphine in particular, acted as toxic agents upon the phylloxera; and therefore carbide containing an extra amount of decomposable phosphides was specially manufactured for the vine-growers. But more recently it has been argued, with some show of reason, that the acetylene itself plays a part in the process, the effects produced being said to be too great to be ascribed wholly to the phosphine. It is well known that many hydrocarbon vapours, such as the vapour of benzene or of naphthalene, have a highly toxic action on low organisms, and the destructive effect of acetylene on phylloxera may be akin to this action. As gaseous acetylene will bear a certain amount of pressure in safety--a pressure falling somewhat short of one effective atmosphere--and as pressure naturally rises in a generating apparatus where calcium carbide reacts with water, it becomes possible to use this pressure as a source of energy for several purposes. The pressure of the gas may, in fact, be employed either to force a stream of liquid through a pipe, or to propel certain mechanism. An apparatus has been constructed in France on the lines of some portable fire-extinguishing appliances in which the pressure set up by the evolution of acetylene in a closed space produces a spray of water charged with lime and gas under the pressure obtaining; the liquid being thrown over growing vines or other plants in order to destroy parasitic and other forms of life. The apparatus consists of a metal cylinder fitted with straps so that it can be carried by man or beast. At one end it has an attachment for a flexible pipe, at the other end a perforated basket for carbide introduced and withdrawn through a "man-hole" that can be tightly closed. The cylinder is filled with water to a point just below the bottom of the basket when the basket is uppermost; the carbide charge is then inserted, and the cover fastened down. As long as the cylinder is carried in the same position, no reaction between the carbide and the water occurs, and consequently no pressure arises; but on inverting the vessel, the carbide is wetted, and acetylene is liberated in the interior. On opening the cock on the outlet pipe, a stream of liquid issues and may be directed as required. By charging the cylinder in the first place with a solution of copper sulphate, the liquid ejected becomes a solution and suspension of copper and calcium salts and hydroxides, resembling "Bordeaux mixture," and may be employed as such. In addition, it is saturated with acetylene which adds to its value as a germicide. The effective gas pressure set up in a closed generator has also been employed in Italy to drive a gas-turbine, and so to produce motion. The plant has been designed for use in lighthouses where acetylene is burnt, and where a revolving or flashing light is required. The gas outlet from a suitably arranged generator communicates with the inlet of a gas- turbine, and the outlet of the turbine is connected to a pipe leading to the acetylene burners. The motion of the turbine is employed to rotate screens, coloured glasses, or any desired optical arrangements round the flames; or, in other situations, periodically to open and close a cock on the gas-main leading to the burners. In the latter case, a pilot flame fed separately is always alight, and serves to ignite the gas issuing from the main burners when the cock is opened. Another use for acetylene, which is only dependent upon a suitably lowered price for carbide to become of some importance, consists in the preparation of a black pigment to replace ordinary lampblack. One method for this purpose has been elaborated by Hubou. Acetylene is prepared from carbide smalls or good carbide, according to price, and the gas is pumped into small steel cylinders to a pressure of 2 atmospheres. An electric spark is then passed, and the gas, standing at its limit of safety, immediately dissociates, yielding a quantitative amount of hydrogen and free carbon. The hydrogen is drawn off, collected in holders, and used for any convenient purpose; the carbon is withdrawn from the vessel, and is ready for sale. At present the pigment is much too expensive, at least in British conditions, to be available in the manufacture of black paint; but its price would justify its employment in the preparation of the best grades of printers' ink. One of the authors has examined an average sample and has found it fully equal in every way to blacks, such as those termed "spirit blacks," which fetch a price considerably above their real value. It has a pure black cast of tint, is free from greasy matter, and can therefore easily be ground into water, or into linseed oil without interfering with the drying properties of the latter. Acetylene black has also been tried in calico printing, and has given far better results in tone and strength than other blacks per unit weight of pigment. It may be added that the actual yield of pigment from creosote oils, the commonest raw material for the preparation of lampblack ("vegetable black"), seldom exceeds 20 or 25 per cent., although the oil itself contains some 80 per cent, of carbon. The yield from acetylene is clearly about 90 per cent., or from calcium carbide nearly 37.5 per cent, of the original weight. An objection urged against the Hubou process is that only small quantities of the gas can be treated with the spark at one time; if the cylinders are too large, it is stated, tarry by-products are formed. A second method of preparing lampblack (or graphite) from acetylene is that devised by Frank, and depends on utilising the reactions between carbon monoxide or dioxide and acetylene or calcium carbide, which have already been sketched in Chapter VI. When acetylene is employed, the yield is pure carbon, for the only by-product is water vapour; but if the carbide process is adopted, the carbon remains mixed with calcium oxide. Possibly such a material as Frank's carbide process would give, viz., 36 parts by weight of carbon mixed with 56 parts of quicklime or 60 parts of carbon mixed with 112 parts of quicklime, might answer the purpose of a pigment in some black paints where the amount of ash left on ignition is not subject to specification. Naturally, however, the lime might be washed away from the carbon by treatment with hydrochloric acid; but the cost of such a purifying operation would probably render the residual pigment too expensive to be of much service except (conceivably) in the manufacture of certain grades of printers' ink, for which purpose it might compete with the carbon obtainable by the Hubou process already referred to. Acetylene tetrachloride, or tetrachlorethane, C_2H_2Cl_4, is now produced for sale as a solvent for chlorine, sulphur, phosphorus, and organic substances such as fats. It may be obtained by the direct combination of acetylene and chlorine as explained in Chapter VI., but the liability of the reaction to take place with explosive violence would preclude the direct application of it on a commercial scale. Processes free from such risk have now, however, been devised for the production of tetrachlorethane. One patented by the Salzbergwerk Neu-Stassfurt consists in passing acetylene into a mixture of finely divided iron and chloride of sulphur. The iron acts as a catalytic. The liquid is kept cool, and as soon as the acetylene passes through unabsorbed, its introduction is stopped and chlorine is passed in. Acetylene and chlorine are then passed in alternately until the liquid finally is saturated with acetylene. The tetrachlorethane, boiling at 147° C., is then distilled off, and the residual sulphur is reconverted to the chloride for use again in the process. A similar process in which the chlorine is used in excess is applicable also to the production of hexachlorethane. Dependent upon price, again, are several uses for calcium carbide as a metallurgical or reducing reagent; but as those are uses for carbide only as distinguished from acetylene, they do not fall within the purview of the present book. When discussing, in Chapter III., methods for disposing of the lime sludge coming from an acetylene generator, it was stated that on occasion a use could be found for this material. If the carbide has been entirely decomposed in an apparatus free from overheating, the waste lime is recovered as a solid mass or as a cream of lime practically pure white in colour. Sometimes, however, as explained in Chapter II., the lime sludge is of a bluish grey tint, even in cases where the carbide decomposed was of good quality and there was no overheating in the generator. Such discoloration is of little moment for most of the uses to which the sludge may be put. The residue withdrawn from a carbide-to-water generator is usually quite fluid; but when allowed to rest in a suitable pit or tank, it settles down to a semi-solid or pasty mass which contains on a rough average 47 per cent. of water and 53 per cent. of solid matter, the amount of lime present, calculated as calcium oxide, being about 40 per cent. Since 64 parts by weight of pure calcium carbide yield 74 parts of dry calcium hydroxide, it may be said that 1 part of ordinary commercial carbide should yield approximately 1.1 parts of dry residue, or 2.1 parts of a sludge containing 47 per cent. of moisture; and sludge of this character has been stated by Vogel to weigh about 22.5 cwt. per cubic yard. Experience has shown that those pasty carbide residues can be employed very satisfactorily, and to the best advantage from the maker's point of view, by builders and decorators for the preparation of ordinary mortar or lime-wash. The mortar made from acetylene lime has been found equal in strength and other properties to mortar compounded from fresh slaked lime; while the distemper prepared by diluting the sludge has been used most successfully in all places where a lime-wash is required, _e.g._, on fruit-trees, on cattle-pens, farm-buildings, factories, and the "offices" of a residence. Many of the village installations abroad sell their sludge to builders for the above-mentioned purposes at such a price that their revenue accounts are materially benefited by the additional income. The sludge is also found serviceable for softening the feed-water of steam boilers by the common liming process; although it has been stated that the material contains certain impurities--notably "fatty matter"--which becomes hydrolysed by the steam, yielding fatty acids that act corrosively upon the boiler-plates. This assertion would appear to require substantiation, but a patent has been taken out for a process of drying the sludge at a temperature of 150° to 200° C. in order to remove the harmful matter by the action of the steam evolved. So purified, it is claimed, the lime becomes fit for treating any hard potable or boiler- feed water. It is very doubtful, however, whether the intrinsic value of acetylene lime is such in comparison with the price of fresh lime that, with whatever object in view, it would bear the cost of any method of artificial drying if obtained from the generators in a pasty state. When, on the other hand, the residue is naturally dry, or nearly so, it is exactly equal to an equivalent quantity of quick or slaked lime as a dressing for soil. In this last connexion, however, it must be remembered that only certain soils are improved by an addition of lime in any shape, and therefore carbide residues must not be used blindly; but if analysis indicates that a particular plot of ground would derive benefit from an application of lime, acetylene lime is precisely as good as any other description. Naturally a residue containing unspent carbide, or contaminated with tarry matter, is essentially valueless (except as mentioned below); while it must not be forgotten that a solid residue if it is exposed to air, or a pasty residue if not kept under water, will lose many of its useful properties, because it will be partially converted into calcium carbonate or chalk. Nevertheless, in some respects, the residue from a good acetylene generator is a more valuable material, agriculturally speaking, than pure lime. It contains a certain amount of sulphur, &c., and it therefore somewhat resembles the spent or gas lime of the coal-gas industry. This sulphur, together, no doubt, with the traces of acetylene clinging to it, renders the residue a valuable material for killing the worms and vermin which tend to infest heavily manured and under-cultivated soil. Acetylene lime has been found efficacious in exterminating the "finger-and-toe" of carrots, the "peach-curl" of peach-trees, and in preventing cabbages from being "clubbed." It may be applied to the ground alone, or after admixture with some soil or stable manure. The residue may also be employed, either alone or mixed with some agglomerate, in the construction of garden paths and the like. If the residues are suitably diluted with water and boiled with (say) twice their original weight of flowers of sulphur, the product consists of a mixture of various compounds of calcium and sulphur, or calcium sulphides--which remain partly in solution and partly in the solid state. This material, used either as a liquid spray or as a moist dressing, has been said to prove a useful garden insecticide and weed-killer. There are also numerous applications of the acetylene light, each of much value, but involving no new principle which need be noticed. The light is so actinic, or rich in rays acting upon silver salts, that it is peculiarly useful to the photographer, either for portraiture or for his various positive printing operations. Acetylene is very convenient for optical lantern work on the small scale, or where the oxy-hydrogen or oxy-coal-gas light cannot be used. Its intensity and small size make its self-luminous flame preferable on optical grounds to the oil-lamp or the coal-gas mantle; but the illuminating surface is nevertheless too large to give the best results behind such condensers as have been carefully worked to suit a source of light scarcely exceeding the dimensions of a point. For lantern displays on very large screens, or for the projection of a powerful beam of light to great distances in one direction (as in night signalling, &c.), the acetylene blowpipe fed with pure oxygen, or with air containing more than its normal proportion of oxygen, which is discussed in Chapter IX., is specially valuable, more particularly if the ordinary cylinder of lime is replaced by one of magnesia, zirconia, or other highly refractory oxide. CHAPTER XIII PORTABLE ACETYLENE LAMPS AND PLANT It will be apparent from what has been said in past chapters that the construction of a satisfactory generator for portable purposes must be a problem of considerable complexity. A fixed acetylene installation tends to work the more smoothly, and the gas evolved therefrom to burn the more pleasantly, the more technically perfect the various subsidiary items of the plant are; that is to say, the more thoroughly the acetylene is purified, dried, and delivered at a strictly constant pressure to the burners and stoves. Moreover, the efficient behaviour of the generator itself will depend more upon the mechanical excellence and solidity of its construction than (with one or two exceptions) upon the precise system to which it belongs. And, lastly, the installation will, broadly speaking, work the better, the larger the holder is in proportion to the demands ever made upon it; while that holder will perform the whole duty of a gasholder more effectually if it belongs to the rising variety than if it is a displacement holder. All these requirements of a good acetylene apparatus have to be sacrificed to a greater or less extent in portable generators; and since the sacrifice becomes more serious as the generator is made smaller and lighter in weight, it may be said in general terms that the smaller a portable (or, indeed, other) acetylene apparatus is, the less complete or permanent satisfaction will it give its user. Again, small portable apparatus are only needed to develop intensities of light insignificant in comparison with those which may easily be won from acetylene on a larger scale; they are therefore fitted with smaller burners, and those burners are not merely small in terms of consumption and illuminating power, but not infrequently are very badly constructed, and are relatively deficient in economy or duty. Thus any comparisons which may be made on lines similar to those adopted in Chapter I., or between unit weights, volumes, or monetary equivalents of calcium carbide, paraffin, candles, and colza oil, become utterly incorrect if the carbide is only decomposed in a small portable generator fitted with an inefficient jet; first, because the latent illuminating power of the acetylene evolved is largely wasted; secondly, because any gas produced over and above that capable of instant combustion must be blown off from a vent-pipe; and thirdly, because the carbide itself tends to be imperfectly decomposed, either through a defect in the construction of the lamp, or through the brief and interrupted requirements of the consumer. In several important respects portable acetylene apparatus may be divided into two classes from a practical point of view. There is the portable table or stand lamp intended for use in an occupied room, and there is the hand or supported lamp intended for the illumination of vehicles or open-air spaces. Economy apart, no difficulty arises from imperfect combustion or escape of unburnt gas from an outdoor lamp, but in a room the presence of unburnt acetylene must always be offensive even if it is not dangerous; while the combustion products of the impurities--and in a portable generator acetylene cannot be chemically purified--are highly objectionable. It is simply a matter of good design to render any form of portable apparatus safe against explosion (employment of proper carbide being assumed), for one or more vent-pipes can always be inserted in the proper places; but from an indoor lamp those vent-pipes cannot be made to discharge into a place of safety, while, as stated before, a generator in which the vent-pipes come into action with any frequency is but an extravagant piece of apparatus for the decomposition of so costly a material as calcium carbide. Looked at from one aspect the holder of a fixed apparatus is merely an economical substitute for the wasteful vent- pipe, because it is a place in which acetylene can be held in reserve whenever the make exceeds the consumption in speed. It is perhaps possible to conceive of a large table acetylene lamp fitted with a water- sealed rising holder; but for vehicular purposes the displacement holder is practically the only one available, and in small apparatus it becomes too minute in size to be of much service as a store for the gas produced by after-generation. Other forms of holder have been suggested by inventors, such as a collapsible bag of india-rubber or the like; but rubber is too porous, weak, and perishable a material to be altogether suitable. If it is possible, by bringing carbide and water into mutual contact in predetermined quantities, to produce gas at a uniform rate, and at one which corresponds with the requirements of the burner, in a small apparatus--and experience has shown it to be possible within moderately satisfactory limits--it is manifest that the holder is only needed to take up the gas of after-generation; and in Chapters II. and III. it was pointed out that after-generation only occurs when water is brought into contact with an excess of carbide. If, then, the opposite system of construction is adopted, and carbide is fed into water mechanically, no after-generation can take place; and provided the make of gas can be controlled in a small carbide-feed generator as accurately as is possible in a small water-to-carbide generator, the carbide-feed principle will exhibit even greater advantages in portable apparatus than it does in plant of domestic size. Naturally almost every variety of carbide-feeding gear, especially when small, requires or prefers granulated (or granulated and "treated") carbide; and granulated carbide must inevitably be considerably more expensive per unit of light evolved than the large material, but probably in the application to which the average portable acetylene apparatus is likely to be put, strict economy is not of first consequence. In portable acetylene generators of the carbide-feed type, the supply is generally governed by the movements of a mushroom-headed or conical valve at the mouth of a conical carbide vessel; such movements occurring in sympathy with the alterations in level of the water in the decomposing chamber, which is essentially a small displacement holder also, or being produced by the contraction of a flexible chamber through which the gas passes on its way to the burner. So far as it is safe to speak definitely on a matter of this kind, the carbide-feed device appears to work satisfactorily in a stationary (_e.g._, table) lamp; but it is highly questionable whether it could be applied to a vehicular apparatus exposed to any sensible amount of vibration. The device is satisfactory on the table of an occupied room so far, be it understood, as any small portable generators can be: it has no holder, but since no after-generation occurs, no holder is needed; still the combustion products contaminate the room with all the sulphur and phosphorus of the crude acetylene. For vehicular lamps, and probably for hand lanterns, the water-to-carbide system has practically no alternative (among actual generators), and safety and convenience have to be gained at the expense of the carbide. In such apparatus the supply of water is usually controlled ultimately by pressure, though a hand-operated needle-valve is frequently put on the water tube. The water actually reaches the carbide either by dropping from a jet, by passing along, upwards or downwards, a "wick" such as is used in oil-lamps, or by percolating through a mass of porous material like felt. The carbide is held in a chamber closed except at the gas exit to the burner and at the inlet from the water reservoir: so that if gas is produced more rapidly than the burner takes it, more water is prevented from entering, or the water already present is driven backwards out of the decomposing chamber into some adjoining receptacle. It is impossible to describe in detail all the lamps which have been constructed or proposed for vehicular use; and therefore the subject must be approached in general terms, discussing simply the principles involved in the design of a safe portable generator. In all portable apparatus, and indeed in generators of larger dimensions, the decomposing chamber must be so constructed that it can never, even by wrong manipulation, be sealed hermetically against the atmosphere. If there is a cock on the water inlet tube which is capable of being completely shut, there must be no cock between the decomposing chamber and the burner. If there is a cock between the carbide vessel and the burner, the water inlet tube must only be closed by the water, being water-sealed, in fact, so that if pressure rises among the carbide the surplus gas may blow the seal or bubble through the water in the reservoir. If the water-supply is mainly controlled by a needle-valve, it is useful to connect the burner with the carbide vessel through a short length of rubber tube; and if this plan is adopted, a cock can, if desired, be put close to the burner. The rubber should not be allowed to form a bend hanging down, or water vapour, &c., may condense and extinguish the flame. In any case there should be a steady fall from the burner to the decomposing chamber, or to some separate catch-pit for the products of condensation. Much of the success attainable with small generators will depend on the water used. If it is contaminated with undissolved matter, the dirt will eventually block the fine orifices, especially the needle-valve, or will choke the pores of the wick or the felt pad. If the water contains an appreciable amount of "temporary hardness," and if it becomes heated much in the lamp, fur will be deposited sooner or later, and will obviously give trouble. Where the water reservoir is at the upper part of the lamp, and the liquid is exposed to the heat of the flame, fur will appear quickly if the water is hard. Considerable benefit would accrue to the user of a portable lamp by the employment of rain water filtered, if necessary, through fabric or paper. The danger of freezing in very severe weather may be prevented by the use of calcium chloride, or preferably, perhaps, methylated spirit in the water (_cf._ Chapter III., p. 92). The disfavour with which cycle and motor acetylene lamps are frequently regarded by nocturnal travellers, other than the users thereof, is due to thoughtless design in the optical part of such lamps, and is no argument against the employment of acetylene. By proper shading or deflection of the rays, the eyes of human beings and horses can be sufficiently protected from the glare, and the whole of the illumination concentrated more perfectly on the road surface and the lower part of approaching objects--a beam of light never reaching a height of 5 feet above the ground is all that is needed to satisfy all parties. As the size of the generator rises, conditions naturally become more suited to the construction of a satisfactory apparatus; until generators intended to supply light to the whole of (say) a railway carriage, or the head and cab lamps of a locomotive, or for the outside and inside lighting of an omnibus are essentially generators of domestic dimensions somewhat altered in internal construction to withstand vibration and agitation. As a rule there is plenty of space at the side of a locomotive to carry a generator fitted with a displacement holder of sufficient size, which is made tall rather than wide, to prevent the water moving about more than necessary. From the boiler, too, steam can be supplied to a coil to keep the liquid from freezing in severe weather. Such apparatus need not be described at length, for they can be, and are, made on lines resembling those of domestic generators, though more compactly, and having always a governor to give a constant pressure. For carriage lighting any ordinary type of generator, preferably, perhaps, fitted with a displacement holder, can be erected either in each corridor carriage, or in a brake van at the end of the train. Purifiers may be added, if desired, to save the burners from corrosion; but the consumption of unpurified gas will seldom be attended by hygienic disadvantages, because the burners will be contained in closed lamps, ventilating into the outside air. The generator, also, may conveniently be so constructed that it is fed with carbide from above the roof, and emptied of lime sludge from below the floor of the vehicle. It can hardly be said that the use of acetylene generated on board adds a sensible risk in case of collision. In the event of a subsequent fire, the gas in the generator would burn, but not explode; but in view of the greater illuminating power per unit volume of carbide than per equal volume of compressed oil- gas, a portable acetylene generator should be somewhat less objectionable than broken cylinders of oil-gas if a fire should follow a railway accident of the usual kind. More particularly by the use of "cartridges" of carbide, a railway carriage generator can be constructed of sufficient capacity to afford light for a long journey, or even a double journey, so that attention would be only required (in the ordinary way) at one end of the line. Passing on from the generators used for the lighting of vehicles and for portable lamps for indoor lighting to the considerably larger portable generators now constructed for the supply of acetylene for welding purposes and for "flare" lamps, it will be evident that they may embody most or all of the points which are essential to the proper working of a fixed generator for the supply of a small establishment. The holder will generally be of the displacement type, but some of these larger portable generators are equipped with a rising holder. The generators are, naturally, automatic in action, but may be either of the water-to-carbide or carbide-to-water type--the latter being preferable in the larger sizes intended for use with the oxy-acetylene blow-pipe for welding, &c., for which use a relatively large though intermittent supply of acetylene is called for. The apparatus is either carried by means of handles or poles attached to it, or is mounted on a wheelbarrow or truck for convenience of transport to the place where it is to be used. The so called "flare" lamps, which are high power burners mounted, with or without a reflector, above a portable generator, are extremely useful for lighting open spaces where work has to be carried on temporarily after nightfall, and are rapidly displacing oil-flares of the Lucigen type for such purposes. The use of "cartridges" of calcium carbide has already been briefly referred to in Chapters II. and III. These cartridges are usually either receptacles of thin sheet-metal, say tin plate, or packages of carbide wrapped up in grease proof paper or the like. If of metal, they may have a lid which is detached or perforated before they are put into the generator, or the generator (when automatic and of domestic size) may be so arranged that a cartridge is punctured in one or more places whenever more gas is required. If wrapped in paper, the cartridges may be dropped into water by an automatic generator at the proper times, the liquid then loosening the gum and so gaining access to the interior; or one spot may be covered by a drape of porous material (felt) only, through which the water penetrates slowly. The substance inside the cartridge may be ordinary, granulated, or "treated" carbide. Cartridges or "sticks" of carbide are also made without wrappings, either by moistening powdered carbide with oil and compressing the whole into moulds, or by compressing dry carbide dust and immersing the sticks in oil or molten grease. The former process is said to cause the carbide to take up too much oil, so that sticks made by the second method are reputed preferable. All these cartridges have the advantage over common carbide of being more permanent in damp air, of being symmetrical in shape, of decomposing at a known speed, and of liberating acetylene in known quantity; but evidently they are more expensive, owing to the cost of preparing them, &c. They may be made more cheaply from the dust produced in the braking of carbide, but in that case the yield of gas will be relatively low. It is manifest that, where space is to spare, purifiers containing the materials mentioned in Chapter V. can be added to any portable acetylene apparatus, provided also that the extra weight is not prohibitive. Cycle lamps and motor lamps must burn an unpurified gas unpurified from phosphorus and sulphur; but it is always good and advisable to filter the acetylene from dust by a plug of cotton wool or the like, in order to keep the burners as clear as may be. A burner with a screwed needle for cleaning is always advantageous. Formerly the burners used on portable acetylene lamps were usually of the single jet or rat-tail, or the union jet or fish tail type, and exhibited in an intensified form, on account of their small orifices, all the faults of these types of burners for the consumption of acetylene (see Chapter VIII.). Now, however, there are numerous special burners adapted for use in acetylene cycle and motor lamps, &c., and many of these are of the impinging jet type, and some have steatite heads to prevent distortion by the heat. One such cycle- lamp burner, as sold in England by L. Wiener, of Fore Street, London, is shown in Fig. 21. A burner constructed like the "Kona" (Chapter VIII.) is made in small sizes (6, 8 and 10 litres per hour) for use in vehicular lamps, under the name of the "Konette," by Falk, Stadelmann and Co., Ltd., of London, who also make a number of other small impinging jet burners. A single jet injector burner on the "Phôs" principle is made in small sizes by the Phôs Co., of London, specially for use in lamps on vehicles. [Illustration: FIG. 21.--CYCLE-LAMP BURNER NO. 96042A.] Nevertheless, although satisfactory medium-sized vehicular lamps for the generation of acetylene have been constructed, the best way of using acetylene for all such employments as these is to carry it ready made in a state of compression. For railway purposes, where an oil-gas plant is in existence, and where it is merely desired to obtain a somewhat brighter light, the oil-gas may be enriched with 20 per cent. of acetylene, and the mixed gas pumped into the same cylinders to a pressure of 10 atmospheres, as mentioned in Chapter XI.; the only alteration necessary being the substitution of suitable small burners for the common oil-gas jets. As far as the plant is concerned, all that is required is a good acetylene generator, purifier, and holder from which the acetylene can be drawn or forced through a meter into a larger storage holder, the meter being connected by gearing with another meter on the pipe leading from the oil-gas holder to the common holder, so that the necessary proportions of the two gases shall be introduced into the common holder simultaneously. From this final holder the enriched gas will be pumped into the cylinders or into a storage cylinder, by means of a thoroughly cooled pump, so that the heat set free by the compression may be safely dissipated. Whenever still better light is required in railway carriages, as also for the illumination of large, constantly used vehicles, such as omnibuses, the acetone process (_cf._ Chapter XI.) exhibits notable advantages. The light so obtained is the light of neat acetylene, but the gas is acetylene having an upper limit of explosibility much lower than usual because of the vapour of acetone in it. In all other respects the presence of the acetone will be unnoticeable, for it is a fairly pure organic chemical body, which burns in the flame completely to carbon dioxide and water, exactly as acetylene itself does. If the acetylene is merely compressed into porous matter without acetone, the gas burnt is acetylene simply; but per unit of volume or weight the cylinders will not be capable of developing so much light. In the United States, at least one railway system (The Great Northern) has a number of its passenger coaches lighted by means of plain acetylene carried in a state of compression in cylinders without porous matter. The gas is generated, filtered from dust, and stored in an ordinary rising holder at a factory alongside the line; being drawn from this holder through a drier to extract moisture, and through a safety device, by a pump which, in three stages, compresses the acetylene into large storage reservoirs. The safety device consists of a heavy steel cylinder filled with some porous substance which, like the similar material of the acetone cylinders, prevents any danger of the acetylene contained in the water-sealed holder being implicated in an explosion starting backwards from the compression, by extinguishing any spark which might be produced there. The plant on the trains comprises a suitable number of cylinders, filled by contact with the large stores of gas to a pressure of 10 atmospheres, pipes of fusible metal communicating with the lamps, and ordinary half-foot acetylene burners. The cylinders are provided with fusible plugs, so that, in the event of a fire, they and the service- pipes would melt, allowing the gas to escape freely and burn in the air, instead of exploding or dissociating explosively within the cylinders should the latter be heated by any burning woodwork or the like. It is stated that this plan of using acetylene enables a quantity of gas to be carried under each coach which is sufficient for a run of from 53 to 70 hours' duration, or of over 3600 miles; that is to say, enables the train, in the conditions obtaining on the line in question, to make a complete "round trip" without exhaustion of its store of artificial light. The system has been in operation for some years, and appears to have been so carefully managed that no accident has arisen; but it is clear that elements of danger are present which are eliminated when the cylinders are loaded with porous matter and acetone. The use of a similar system of compressed acetylene train lighting in South America has been attended with a disastrous explosion, involving loss of life. It may safely be said that the acetone system, or less conveniently perhaps the mere compression into porous matter, is the best to adopt for the table-lamp which is to be used in occupied rooms Small cylinders of such shapes as to form an elegant base for a table-lamp on more or less conventional lines would be easy to make. They would be perfectly safe to handle. If accidentally or wilfully upset, no harm would arise. By deliberate ill-treatment they might be burst, or the gas-pipe fractured below the reducing valve, so that gas would escape under pressure for a time; but short of this they would be as devoid of extra clangor in times of fire as the candle or the coal-gas burner. Moreover, they would only contaminate the air with carbon dioxide and water vapour, for the gas is purified before compression; and modern investigations have conclusively demonstrated that the ill effects produced in the air of an imperfectly ventilated room by the extravagant consumption of coal-gas depend on the accumulation of the combustion products of the sulphur in the gas rather than upon the carbon dioxide set free. One particular application of the portable acetylene apparatus is of special interest. As calcium carbide evolves an inflammable gas when it merely comes into contact with water, it becomes possible to throw into the sea or river, by hand or by ejection from a mortar, a species of bomb or portable generator which is capable of emitting a powerful beam of light if only facilities are present for inflaming the acetylene generated; and it is quite easy so to arrange the interior of such apparatus that they can be kept ready for instant use for long periods of time without sensible deterioration, and that they can be recharged after employment. Three methods of firing the gas have been proposed. In one the shock or contact with the water brings a small electric battery into play which produces a spark between two terminals projecting across the burner orifice; in the second, a cap at the head of the generator contains a small quantity of metallic potassium, which decomposes water with such energy that the hydrogen liberated catches fire; and in the third a similar cap is filled with the necessary quantity of calcium phosphide, or the "carbophosphide of calcium" mentioned in Chapter XI., which yields a flame by the immediate ignition of the liquid phosphine produced on the attack of water. During the two or three seconds consumed in the production of the spark or pilot flame, the water is penetrating the main charge of calcium carbide in the interior of the apparatus, until the whole is ready to give a bright light for a time limited only by the capacity of the generator. It is obvious that such apparatus may be of much service at sea: they may be thrown overboard to illuminate separate lifebuoys in case of accident, or be attached to the lifebuoys they are required to illuminate, or be used as lifebuoys themselves if fitted with suitable chains or ropes; they may be shot ahead to illuminate a difficult channel, or to render an enemy visible in time of war. Several such apparatus have already been constructed and severely tested; they appear to give every satisfaction. They are, of course, so weighted that the burner floats vertically, while buoyancy is obtained partly by the gas evolved, and partly by a hollow portion of the structure containing air. Cartridges of carbide and caps yielding a self- inflammable gas can be carried on board ship, by means of which the torches or lifebuoys may be renewed after service in a few minutes' time. CHAPTER XIV VALUATION AND ANALYSIS OF CARBIDE The sale and purchase of calcium carbide in this country will, under existing conditions, usually be conducted in conformity with the set of regulations issued by the British Acetylene Association, of which a copy, revised to date, is given below: "REGULATIONS AS TO CARBIDE OF CALCIUM." 1. The carbide shall be guaranteed by the seller to yield, when broken to standard size, _i.e._, in lumps varying from 1 to 2-1/2 inches or larger, not less than 4.8 cubic feet per lb., at a barometric pressure of 30 inches and temperature of 60° Fahr. (15.55° Centigrade). The actual gas yield shall be deemed to be the gas yield ascertained by the analyst, plus 5 per cent. "Carbide yielding less than 4.8 cubic feet in the sizes given above shall be paid for in proportion to the gas yield, _i.e._, the price to be paid shall bear the same relation to the contract price as the gas yield bears to 4.8 cubic feet per lb. "2. The customer shall have the right to refuse to take carbide yielding in the sizes mentioned above less than 4.2 cubic foot, per lb., and it shall lie, in case of refusal and as from the date of the result, of the analysis being made known to either party, at the risk and expense of the seller. "3. The carbide shall not contain higher figures of impurities than shall from time to time be fixed by the Association. "4. No guarantee shall be given for lots of less than 3 cwt., or for carbide crushed to smaller than the above sizes. "5. In case of dispute as to quality, either the buyer or the seller shall have the right to have one unopened drum per ton of carbide, or part of a ton, sent for examination to one of the analysts appointed by the Association, and the result of the examination shall be held to apply to the whole of the consignment to which the drum belonged. "6. A latitude of 5 per cent, shall be allowed for analysis; consequently differences of 5 per cent. above or below the yields mentioned in 1 and 2 shall not be taken into consideration. "7. Should the yield of gas be less than 4.8 cubic feet less 5 per cent., the carriage of the carbide to and from the place of analysis and the cost of the analysis shall be paid for by the seller. Should the yield be more than 4.8 cubic feet less 5 per cent., the carriage and costs of analysis shall be borne by the buyer, who, in addition, shall pay an increase of price for the carbide proportionate to the gas yield above 4.8 cubic feet plus 5 per cent. "8. Carbide of 1 inch mesh and above shall not contain more than 5 per cent. of dust, such dust to be defined as carbide capable of passing through a mesh of one-sixteenth of an inch. "9. The seller shall not be responsible for deterioration of quality caused by railway carriage in the United Kingdom, unless he has sold including carriage to the destination indicated by the buyer. "10. Carbide destined for export shall, in case the buyer desires to have it tested, be sampled at the port of shipment, and the guarantee shall cease after shipment. "11. The analyst shall take a sample of not less than 1 lb. each from the top, centre, and bottom of the drum. The carbide shall be carefully broken up into small pieces, due care being taken to avoid exposure to the air as much as possible, carefully screened and tested for gas yield by decomposing it in water, previously thoroughly saturated by exposure to acetylene for a period of not less than 48 hours. "12. Carbide which, when properly decomposed, yields acetylene containing from all phosphorus compounds therein more than .05 per cent. by volume of phosphoretted hydrogen, may be refused by the buyer, and any carbide found to contain more than this figure, with a latitude of .01 per cent. for the analysis, shall lie at the risk and expense of the seller in the manner described in paragraph 2. "The rules mentioned in paragraph 7 shall apply as regards the carriage and costs of analysis; in other words, the buyer shall pay these costs if the figure is below 0.05 per cent. plus 0.01 per cent., and the seller if the figure is above 0.05 per cent. plus 0.01 per cent. "The sampling shall take place in the manner prescribed in paragraphs 5 and 11, and the analytical examination shall be effected in the manner prescribed by the Association and obtainable upon application to the Secretary." * * * * * The following is a translation of the corresponding rules issued by the German Acetylene Association (_Der Deutsche Acetylenverein_) in regard to business dealings in calcium carbide, as put into force on April 1, 1909: "REGULATIONS OF THE GERMAN ACETYLENE ASSOCIATION FOR TRADE IN CARBIDE. "_Price_. "The price is to be fixed per 100 kilogrammes (= 220 lb.) net weight of carbide in packages containing about 100 kilogrammes. "By packages containing about 100 kilogrammes are meant packages containing within 10 per cent. above or below that weight. "The carbide shall be packed in gas- and water-tight vessels of sheet- iron of the strength indicated in the prescriptions of the carrying companies. "The prices for other descriptions of packing must be specially stated. "_Place of Delivery_. "For consignment for export, the last European shipping port shall be taken as the place of delivery. "_Quality_. "Commercial carbide shall be of such quality that in the usual lumps of 15 to 80 mm. (about 3/5 to 3 inches) diameter it shall afford a yield of at least 300 litres at 15° C. and 760 mm. pressure of crude acetylene per kilogramme for each consignment (= 4.81 cubic feet at 60° F. and 30 inches per lb.). A margin of 2 per cent. shall be allowed for the analysis. Carbide which yields less than 300 litres per kilogramme, but not less than 270 litres (= 4.33 cubic feet) of crude acetylene per kilogramme (with the above-stated 2 per cent. margin for analysis) must be accepted by the buyer. The latter, however, is entitled to make a proportionate deduction from the price and also to deduct the increased freight charges to the destination or, if the latter is not settled at the time when the transaction is completed, to the place of delivery. Carbide which yields less than 270 litres of crude acetylene per kilogramme need not be accepted. "Carbide must not contain more than 5 per cent. of dust. By dust is to be understood all which passes through a screen of 1 mm. (0.04 inch) square, clear size of holes. "Small carbide of from 4 to 15 mm. (= 1/6 to 3/5 inch) in size (and intermediate sizes) must yield on the average for each delivery at least 270 litres at 15° C. and 760 mm. pressure of crude acetylene per kilogramme (= 4.33 cubic feet at 60° F. and 30 inches per lb.) A margin of 2 per cent. shall be allowed for the analysis. Small carbide of from 4 to 15 mm. in size (and intermediate sizes) which yields less than 270 litres but not less than 250 litres (= 4.01 cubic feet per lb.) of crude acetylene per kilogramme (with the above-stated 2 per cent. margin for analysis) must be accepted by the buyer. The latter, however, is entitled to make a proportionate deduction from the price and also to deduct the increased freight charges to the destination or, if the latter is not settled at the time when the transaction is completed, to the place of delivery. Small carbide of from 4 to 15 mm. in size (and intermediate sizes) which yields less than 250 litres per kilogramme need not be accepted. "Carbide shall only be considered fit for delivery if the proportion of phosphoretted hydrogen in the crude acetylene does not amount to more than 0.04 volume per cent. A margin of 0.01 volume per cent. shall be allowed for the analysis for phosphoretted hydrogen. The whole of the phosphorus compounds contained in the gas are to be calculated as phosphoretted hydrogen. "_Period for Complaints._ "An interval of four weeks from delivery shall be allowed for complaints for consignments of 5000 kilogrammes (= 5 tons) and over, and an interval of two weeks for smaller consignments. A complaint shall refer only to a quantity of carbide remaining at the time of taking the sample. "_Determination of Quality._ "1. In case the parties do not agree that the consignee is to send to the analyst for the determination of the quality one unopened and undamaged drum when the consignment is less than 5000 kilogrammes, and two such drums when it is over 5000 kilogrammes, a sample for the purpose of testing the quality is to be taken in the following manner: "A sample having a total weight of at least 2 kilogrammes (= 4.4 lb.) is to be taken. If the delivery to be tested does not comprise more than ten drums, the sample is to be taken from an unopened and undamaged drum selected at random. With deliveries of more than ten drums, the sample is to be drawn from not fewer than 10 per cent, of the lot, and from each of the unopened and undamaged drums drawn for the purpose not less than 1 kilogramme (= 2.2 lb.) is to be taken. "The sampling is to be carried out by a trustworthy person appointed by the two parties, or by one of the experts regularly recognised by the German Acetylene Association, thus: Each selected drum, before opening, is to be turned over twice (to got rid of any local accumulation of dust) and the requisite quantity is to be withdrawn with a shovel (not with the hand) from any part of it. These samples are immediately shot into one or more vessels which are closed air- and water-tight. The lid is secured by a seal. No other description of package, such as cardboard cases, boxes, &c., is permissible. "If there is disagreement as to the choice of a trustworthy person, each of the two parties is to take the required quantity, as specified above. "2. The yield of gas and the proportion of phosphoretted hydrogen contained in it are to be determined by the methods prescribed by the German Acetylene Association. If there are different analyses giving non- concordant results, an analysis is to be made by the German Acetylene Association, which shall be accepted as final and binding. "In cases, however, where the first analysis has been made in the Laboratory of the German Acetylene Association and arbitration is required, the decisive analysis shall be made by the Austrian Acetylene Association. If one of the parties prevents the arbitrator's analysis being carried out, the analysis of the other party shall be absolutely binding on him. "3. The whole of the cost of sampling and analysis is to be borne by the party in the wrong." * * * * * The corresponding regulations issued by the Austrian Acetylene Association (_Der Oesterreichische Acetylenverein_) are almost identical with those of the German Association. They contain, however, provisions that the price is to include packing, that the carbide must not be delivered in lumps larger than the fist, that the sample may be sealed in a glass vessel with well-ground glass stopper, that the sample is to be transmitted to the testing laboratory with particulars of the size of the lots and the number of drums drawn for sampling, and that the whole of it is to be gasified in lots of upwards of 1 kilogramme (= 2.2 lb.) apiece. In Italy, it is enacted by the Board of Agriculture, Commerce and Industry that by calcium carbide is to be understood for legal purposes also any other carbide, or carbide-containing mixture, which evolves acetylene by interaction with water. Also that only calcium carbide, which on admixture with water yields acetylene containing less than 1 per cent. of its volume of sulphuretted hydrogen and phosphoretted hydrogen taken together, may be put on the market. It is evident from the regulations quoted that the determination of the volume of gas which a particular sample of calcium carbide is capable of yielding, when a given weight of it is decomposed under the most favourable conditions, is a matter of the utmost practical importance to all interested in the trafficking of carbide, _i.e._, to the makers, vendors, brokers, and purchasers of that material, as well as to all makers and users of acetylene generating plant. The regulations of the British Association do not, however, give details of the method which the analyst should pursue in determining the yield of acetylene; and while this may to a certain extent be advantageously left to the discretion of the competent analyst, it is desirable that the results of the experience already won by those who have had special opportunities for practising this branch of analytical work should be embodied in a set of directions for the analysis of carbide, which may be followed in all ordinary analyses of that material. By the adoption of such a set of directions as a provisional standard method, disputes as to the quantity of carbide will be avoided, while it will still be open to the competent analyst to modify the method of procedure to meet the requirements of special cases. It would certainly be unadvisable in the present state of our analytical methods to accept any hard and fast of rules for analysis for determining the quality of carbide, but it is nevertheless well to have the best of existing methods codified for the guidance of analysts. The substance of the directions issued by the German Association (_Der Deutsche Acetylenverein_) is reproduced below. "METHODS FOR THE DETERMINATION OF TILE YIELD OF GAS FROM CALCIUM CARBIDE. "The greatest precision is attained when the whole of the sample submitted to the analyst is gasified in a carbide-to-water apparatus, and the gas evolved is measured in an accurately graduated gasholder. "The apparatus used for this analysis must not only admit of all the precautionary rules of gas-analytical work being observed, but must also fulfil certain other experimental conditions incidental to the nature of the analysis. "(_a_) The apparatus must be provided with an accurate thermometer to show the temperature of the confining water, and with a pressure gauge, which is in communication with the gasholder. "(_b_) The generator must either be provided with a gasholder which is capable of receiving the quantity of gas evolved from the whole amount of carbide, or the apparatus must be so constructed that it becomes possible with a gasholder which in not too large (up to 200 litres = say 7 cubic feet capacity) to gasify a larger amount of carbide. "(_c_) The generator must be constructed so that escape of the evolved gas from it to the outer air is completely avoided. "(_d_) The gasholder must be graduated in parts up to 1/4 per cent. of its capacity, must travel easily, and be kept, as far as may be in suspension by counterweighting. "(_e_) The water used for decomposing the carbide and the confining water must be saturated, before use, with acetylene, and, further, the generator must, before the analysis proper, be put under the pressure of the confining (or sealing) liquid." The following is a description of a typical form of apparatus corresponding with the foregoing requirements: "The apparatus, shown in the annexed figure, consists of the generator A, the washer B, and the gasholder C. [Illustration: FIG. 22.--LARGE-SCALE APPARATUS FOR DETERMINING YIELD OF GAS FROM CARBIDE.] "The generator A consists of a cylindrical vessel with sloping bottom, provided with a sludge outlet _a_, a gas exit-pipe _b_, and a lid _b'_ fastened by screws. In the upper part ten boxes _c_ are installed for the purpose of receiving the carbide. The bottoms of those boxes are flaps which rest through their wire projections on a revolvable disc _d_, which is mounted on a shaft _l_. This shaft passes through a stuffing-box to the outside of the generator and can be rotated by moans of the chains _f_, the pulleys _g_ and _h_, and the winch _i_. Its rotation causes rotation of the disc _d_. The disc _d_, on which the bottoms of the carbide- holders are supported, is provided with a slot _e_. On rotating the disc, on which the supporting wires of the bottoms of the carbide-holders rest, the slot is brought beneath these wires in succession; and the bottoms, being thus deprived of their support, drop down. It is possible in this way to effect the discharge of the several carbide-holders by gradual turning of the winch _i_. "The washer B is provided with a thermometer _m_ passing through a sound stuffing-box and extending into the water. "The gasholder C is provided with a scale and pointer, which indicate how much gas there is in it. It is connected with the pressure-gauge _n_, and is further provided with a control thermometer _o_. The gas exit-pipe _q_ can be shut off by a cock. There is a cock between the gasholder and the washer for isolating one from the other. "The dimensions of the apparatus are such that each carbide-holder can contain readily about half a kilogramme (say l lb.) of carbide. The gasholder is of about 200 litres (say 7 cubic feet) capacity; and if the bell is 850 mm. (= 33-1/2 inches) high, and 550 mm. (= 21-1/2 inches) in diameter it will admit of the position being read off to within half a litre (say 0.02 cubic foot)." The directions of the German Association for sampling a consignment of carbide packed in drums each containing 100 kilogrammes (say 2 cwt.) have already been given in the rules of that body. They differ somewhat from those issued by the British Association (_vide ante_), and have evidently been compiled with a view to the systematic and rapid sampling of larger consignments than are commonly dealt with in this country. Drawing a portion of the whole sample from every tenth drum is substantially the same as the British Association's regulations for cases of dispute, viz., to have one unopened drum (_i.e._, one or two cwt.) per ton of carbide placed at the analyst's disposal for sampling. Actually the mode of drawing a portion of the whole sample from every tenth vessel, or lot, where a large number is concerned, is one which would naturally be adopted by analysts accustomed to sampling any other products so packed or stored, and there in no reason why it should be departed from in the case of large consignments of carbide. For lots of less than ten drums, unless there is reason to suspect want of uniformity, it should usually suffice to draw the sample from one drum selected at random by the sampler. The analyst, or person who undertakes the sampling, must, however, exercise discretion as to the scheme of sampling to be followed, especially if want of uniformity of the several lots constituting the consignment in suspected. The size of the lumps constituting a sample will be referred to later. The British Association's regulations lead to a sample weighing about 3 lb. being obtained from each drum. If only one drum is sampled, the quantity taken from each position may be increased with advantage so as to give a sample weighing about 10 lb., while if a large number of drums is sampled, the several samples should be well mixed, and the ordinary method of quartering and re-mixing followed until a representative portion weighing about 10 lb. remains. A sample representative of the bulk of the consignment having been obtained, and hermetically sealed, the procedure of testing by means of the apparatus already described may be given from the German Association's directions: "The first carbide receptacle is filled with 300 to 400 grammes (say 3/4 lb.) of any readily decomposable carbide, and is hung up in the apparatus in such a position with regard to the slot _e_ on the disc _d_ that it will be the first receptacle to be discharged when the winch _i_ is turned. The tin or bottle containing the sample for analysis is then opened and weighed on a balance capable of weighing exactly to 1/2 gramme (say 10 grains). The carbide in it is then distributed quickly, and as far as may be equally, into the nine remaining carbide receptacles, which are then shut and hung up quickly in the generator. The lid _b'_ is then screwed on the generator to close it, and the empty tin or bottle, from which the sample of carbide has been removed, is weighed. "The contents of the first carbide receptacle are then discharged by turning the winch _i_. Their decomposition ensures on the one hand that the sealing water and the generating water are saturated with acetylene, and on the other hand that the dead space in the generator is brought under the pressure of the seal, so that troublesome corrections which would otherwise be entailed are avoided. After the carbide is completely decomposed, but not before two hours at least have elapsed, the cock _p_ is shut, and the gasholder is run down to the zero mark by opening the cock _q_. The cock _q_ is then shut, _p_ is opened, and the analytical examination proper is begun by discharging the several carbide receptacles by turning the winch _i_. After the first receptacle has been discharged, five or ten minutes are allowed to elapse for the main evolution of gas to occur, and the cock _p_ is then shut. Weights are added to the gasholder until the manometer _n_ gives the zero reading; the position of the gasholder C is then read off, and readings of the barometer and of the thermometer _o_ are made. The gasholder is then emptied down to the zero mark by closing the cock _p_ and opening _q_. When this is done _q_ is closed and _p_ is opened, and the winch _i_ is turned until the contents of the next carbide receptacle are discharged. This procedure is followed until the carbide from the last receptacle has been gasified; then, after waiting until all the carbide has been decomposed, but in any case not less than two hours, the position of the gasholder is read, and readings of the barometer and thermometer are again taken. The total of the values obtained represents the yield of gas from the sample examined." The following example is quoted: Weight of the tin received, with its contained | carbide . . . . . ._| = 6325 grammes. Weight of the empty tin . . . . = 1485 " _______ Carbide used . . . = 4840 " = 10670 lb. The carbide in question was distributed among the nine receptacles and gasified. The readings were: ________________________________________________ | | | | | | No. | Litres. | Degrees C. | Millimetres. | |______|__________|______________|_______________| | | | | | | 1 | 152.5 | 13 | 762 | | 2 | 136.6 | " | " | | 3 | 138.5 | " | " | | 4 | 161.0 | " | " | | 5 | 131.0 | " | " | | 6 | 182.5 | 13.5 | " | | 7 | 146.0 | " | " | | 8 | 163.0 | 14.0 | " | | 9 | 178.5 | " | " | |______|__________|______________|_______________| After two hours, the total of the readings was 1395.0 litres at 13.5° C. and 762 mm., which is equivalent to 1403.7 litres (= 49.57 cubic feet) at 15° C. and 760 mm. (or 60° F. and 30 inches; there is no appreciable change of volume of a gas when the conditions under which it is measured are altered from 15° C. and 760 mm. to 60° F. and 30 inches, or _vice versâ_). The yield of gas from this sample is therefore 1403.7/4.840 = 290 litres at 15° C. and 760 mm. per kilogramme, or 49.57/10.67 = 4.65 cubic feet at 60° F. and 30 inches per pound of carbide. The apparatus described can, of course, be used when smaller samples of carbide only are available for gasification, but the results will be less trustworthy if much smaller quantities than those named are taken for the test. Other forms of carbide-to-water apparatus may of course be devised, which will equally well fulfil the requisite conditions for the test, viz., complete decomposition of the whole of the carbide without excessive rise of temperature, and no loss of gas by solution or otherwise. An experimental wet gas-motor, of which the water-line has been accurately set (by means of the Gas Referees' 1/12 cubic foot measure, or a similar meter-proving apparatus), may be used in place of the graduated gasholder for measuring the volume of the gas evolved, provided the rate of flow of the gas does not exceed 1/6 cubic foot, or say 5 litres per minute. If the generation of gas is irregular, as when an apparatus of the type described above is used, it is advisable to insert a small gasholder or large bell-governor between the washer and the meter. The meter must be provided with a thermometer, according to the indications of which the observed volumes must be corrected to the corresponding volume at normal temperature. If apparatus such as that described above is not available, fairly trustworthy results for practical purposes may be obtained by the decomposition of smaller samples in the manner described below, provided these samples are representative of the average composition of the larger sample or bulk, and a number of tests are made in succession and the results of individual tests do not differ by more than 10 litres of gas per kilogramme (or 0.16 cubic foot per pound) of carbide. It is necessary at the outset to reduce large lumps of carbide in the sample to small pieces, and this must be done with as little exposure as possible to the (moist) air. Failing a good pulverising machine of the coffee-mill or similar type, which does its work quickly, the lumps must be broken as rapidly as possible in a dry iron mortar, which may with advantage be fitted with a leather or india-rubber cover, through a hole in which the pestle passes. As little actual dust as possible should be made during pulverisation. The decomposition of the carbide is best effected by dropping it into water and measuring the volume of gas evolved with the precautions usually practised in gas analysis. An example of one of the methods of procedure described by the German Association will show how this test can be satisfactorily carried out: "A Woulff's bottle, _a_ in the annexed figure, of blown glass and holding about 1/4 litre is used as the generating vessel. One neck, about 15 mm. in internal diameter, is connected by flexible tubing with a globular vessel _b_, having two tubulures, and this vessel is further connected with a conical flask _c_, holding about 100 c.c. The other neck is provided with tubing _d_, serving to convey the gas to the inlet-tube, with tap _e_, of the 20-litre measuring vessel _f_, which is filled with water saturated with acetylene, and communicates through its lower tubulure with a similar large vessel _g_. The generating vessel _a_ is charged with about 150 c.c. of water saturated with acetylene. The vessel _f_ is filled up to the zero mark by raising the vessel _g_; the tap _e_ is then shut, and connexion is made with the tube _d_. Fifty grammes (or say 2 oz.) of the pulverised carbide are then weighed into the flask _c_ and this is connected by the flexible tubing with the vessel _b_. The carbide is then decomposed by bringing it in small portions at a time into the bulb _b_ by raising the flask _c_, and letting it drop from _b_ into the generating vessel _a_, after having opened the cock _e_ and slightly raised the vessel _f_. After the last of the carbide has been introduced two hours are allowed to elapse, and the volume of gas in _f_ is then read while the water stands at the same level in _f_ and _g_, the temperature and pressure being noted simultaneously." A second, but less commendable method of decomposing the carbide is by putting it in a dry two-necked bottle, one neck of which is connected with _e_, and dropping water very slowly from a tap-funnel, which enters the other neck, on to the carbide. The generating bottle should be stood in water, in order to keep it cool, and the water should be dropped in at the rate of about 50 c.c. in one hour. It will take about three hours completely to gasify the 50 grammes of carbide under these conditions. The gas is measured as before. [Illustration: FIG. 23.--SMALL-SCALE APPARATUS FOR DETERMINING YIELD OF GAS FROM CARBIDE.] Cedercreutz has carried out trials to show the difference between the yields found from large and small carbide taken from the same drum. One sample consisted of the dust and smalls up to about 3/5 inch in size, while the other contained large carbide as well as the small. The latter sample was broken to the same size as the former for the analysis. Tests were made both with a large testing apparatus, such as that shown in Fig. 22, and with a small laboratory apparatus, such as that shown in Fig. 23. The dust was screened off for the tests made in the large apparatus. Two sets of testings were made on different lots of carbide, distinguished below as "A" and "B," and about 80 grammes wore taken for each determination in the laboratory apparatus, and 500 grammes in the large apparatus. The results are stated in litres (at normal temperature and pressure) per kilogramme of carbide. ___________________________________________________________________ | | | | | | "A" | "B" | |_____________________________________________________|______|______| | | | | | Lot |Litres|Litres| | Small carbide, unscreened, in laboratory \ (1) | 276 | 267 | | apparatus . . . . . / (2) | 273 | 270 | | Average sample of carbide, unscreened, in \ (1) | 318 | 321 | | laboratory apparatus . . . / (2) | 320 | 321 | | Small carbide, dust freed, in large apparatus (1) | 288 | 274 | | Average sample of carbide, dust freed, in \ (2) | 320 | 322 | | large apparatus . . . . / | | | |_____________________________________________________|______|______| As the result of the foregoing researches Cedercreutz has recommended that in order to sample the contents of a drum, they should be tipped out, and about a kilogramme (say 2 to 3 lb.) taken at once from them with a shovel, put on an iron base and broken with a hammer to pieces of about 2/5 inch, mixed, and the 500 grammes required for the analysis in the form of testing plant which he employs taken from this sample. Obviously a larger sample can be taken in the same manner. On the other hand the British and German Associations' directions for sampling the contents of a drum, which have already been quoted, differ somewhat from the above, and must generally be followed in cases of dispute. Cedercreutz's figures, given in the above table, show that it would be very unfair to determine the gas-making capacity of a given parcel of carbide in which the lumps happened to vary considerably in size by analysing only the smalls, results so obtained being possibly 15 per cent. too low. This is due to two causes: first, however carefully it be stored, carbide deteriorates somewhat by the attack of atmospheric moisture; and since the superficies of a lump (where the attack occurs) is larger in proportion to the weight of the lump as the lump itself is smaller, small lumps deteriorate more on keeping than large ones. The second reason, however, is more important. Not being a pure chemical substance, the commercial material calcium carbide varies in hardness; and when it is merely crushed (not reduced altogether to powder) the softer portions tend to fall into smaller fragments than the hard portions. As the hard portions are different in composition from the soft portions, if a parcel is sampled by taking only the smalls, practically that sample contains an excess of the softer part of the original material, and as such is not representative. Originally the German Acetylene Association did not lay down any rules as to the crushing of samples by the analyst, but subsequently they specified that the material should be tested in the size (or sizes) in which it was received. The British Association, on the contrary, requires the sample to be broken in small pieces. If the original sample is taken in such fashion as to include large and small lumps as accurately as possible in the same proportion as that in which they occur in the main parcel, no error will be introduced if that sample is crushed to a uniform size, and then subdivided again; but a small deficiency in gas yield will be produced, which will be in the consumer's favour. It is not altogether easy to see the advantage of the British idea of crushing the sample over the German plan of leaving it alone; because the analytical generator will easily take, or its parts could be modified to take, the largest lumps met with. If the sample is in very large masses, and is decomposed too quickly, polymerisation of gas may be set up; but on the other hand, the crushing and re-sampling will cause wastage, especially in damp weather, or when the sampling has to be done in inconvenient places. The British Association requires the test to be made on carbide parcels ranging between 1 and 2-1/2 inches or larger, because that is the "standard" size for this country, and because no guarantee is to be had or expected from the makers as to the gas-producing capacity of smaller material. Manifestly, if a consumer employs such a form of generator that he is obliged to use carbide below "standard" size, analyses may be made on his behalf in the ordinary way; but he will have no redress if the yield of acetylene is less than the normal. This may appear a defect or grievance; but since in many ways the use of small carbide (except in portable lamps) is not advantageous--either technically or pecuniarily--the rule simply amounts to an additional judicious incentive to the adoption of apparatus capable of decomposing standard-sized lumps. The German and Austrian Associations' regulations, however, provide a standard for the quality of granulated carbide. It has been pointed out that the German Association's direction that the water used in the testing should be saturated with acetylene by a preliminary decomposition of 1/2 kilogramme of carbide is not wholly adequate, and it has been suggested that the preliminary decomposition should be carried out twice with charges of carbide, each weighing not less than 1 per cent. of the weight of water used. A further possible source of error lies in the fact that the generating water is saturated at the prevailing temperature of the room, and liberates some of its dissolved acetylene when the temperature rises during the subsequent generation of gas. This error, of course, makes the yield from the sample appear higher than it actually is. Its effects may be compensated by allowing time for the water in the generator or gasholder to cool to its original temperature before the final reading is made. With regard to the measurement of the temperature of the evolved gas in the bell gasholder, it is usual to assume that the reading of a thermometer which passes through the crown of the gasholder suffices. If the thermometer has a very long stem, so that the bulb is at about the mid-height of the filled bell, this plan is satisfactory, but if an ordinary thermometer is used, it is better to take, as the average temperature of the gas in the holder, the mean of the readings of the thermometer in the crown, and of one dipping into the water of the holder seal. The following table gives factors for correcting volumes of gas observed at any temperature and pressure falling within its range to the normal temperature (60° F.) and normal barometric height (30 inches). The normal volume thus found is, as already stated, not appreciably different from the volume at 15° C. and 760 mm. (the normal conditions adopted by Continental gas chemists). To use the table, find the observed temperature and the observed reading of the barometer in the border of the table, and in the space where these vertical and horizontal columns meet will be found a number by which the observed volume of gas is to be multiplied in order to find the corresponding volume under normal conditions. For intermediate temperatures, &c., the factors may be readily inferred from the table by inspection. This table must only be applied when the gas is saturated with aqueous vapour, as is ordinarily the case, and therefore a drier must not be applied to the gas before measurement. Hammerschmidt has calculated a similar table for the correction of volumes of gas measured at temperatures ranging from 0° to 30° C., and under pressures from 660 to 780 mm., to 15° C. and 760 mm. It is based on the coefficient of expansion of acetylene given in Chapter VI., but, as was there pointed out, this coefficient differs by so little from that of the permanent gases for which the annexed table was compiled, that no appreciable error results from the use of the latter for acetylene also. A table similar to the annexed but of more extended range is given in the "Notification of the Gas Referees," and in the text-book on "Gas Manufacture" by one of the authors. The determination of the amounts of other gases in crude or purified acetylene is for the most part carried out by the methods in vogue for the analysis of coal-gas and other illuminating gases, or by slight modifications of them. For an account of these methods the textbook on "Gas Manufacture" by one of the authors may be consulted. For instance, two of the three principal impurities in acetylene, viz., ammonia and sulphuretted hydrogen, may be detected and estimated in that gas in the same manner as in coal gas. The detection and estimation of phosphine are, however, analytical operations peculiar to acetylene among common illuminating gases, and they must therefore be referred to. _Table to facilitate the Correction of the Volume of Gas at different Temperatures and under different Atmospheric Pressures._ _____________________________________________________ | | | | | THERMOMETER. | | BAR.|_______________________________________________| | | | | | | | | | | 46° | 48° | 50° | 52° | 54° | 56° | |_____|_______|_______|_______|_______|_______|_______| | | | | | | | | |28.4 | 0.979 | 0.974 | 0.970 | 0.965 | 0.960 | 0.955 | |28.5 | 0.983 | 0.978 | 0.973 | 0.968 | 0.964 | 0.959 | |28.6 | 0.986 | 0.981 | 0.977 | 0.972 | 0.967 | 0.962 | |28.7 | 0.990 | 0.985 | 0.980 | 0.975 | 0.970 | 0.966 | |28.8 | 0.993 | 0.988 | 0.984 | 0.979 | 0.974 | 0.969 | |28.9 | 0.997 | 0.992 | 0.987 | 0.982 | 0.977 | 0.973 | |29.0 | 1.000 | 0.995 | 0.990 | 0.986 | 0.981 | 0.976 | |29.1 | 1.004 | 0.999 | 0.994 | 0.989 | 0.984 | 0.979 | |29.2 | 1.007 | 1.002 | 0.997 | 0.992 | 0.988 | 0.982 | |29.3 | 1.011 | 1.005 | 1.001 | 0.996 | 0.991 | 0.986 | |29.4 | 1.014 | 1.009 | 1.004 | 0.999 | 0.995 | 0.990 | |29.5 | 1.018 | 1.013 | 1.008 | 1.003 | 0.998 | 0.993 | |29.6 | 1.021 | 1.016 | 1.011 | 1.006 | 1.001 | 0.996 | |29.7 | 1.025 | 1.019 | 1.015 | 1.010 | 1.005 | 1.000 | |29.8 | 1.028 | 1.023 | 1.018 | 1.013 | 1.008 | 1.003 | |29.9 | 1.031 | 1.026 | 1.022 | 1.017 | 1.012 | 1.007 | |30.0 | 1.035 | 1.030 | 1.025 | 1.020 | 1.015 | 1.010 | |30.1 | 1.038 | 1.033 | 1.029 | 1.024 | 1.019 | 1.014 | |30.2 | 1.042 | 1.037 | 1.032 | 1.027 | 1.022 | 1.017 | |30.3 | 1.045 | 1.040 | 1.036 | 1.030 | 1.025 | 1.020 | |30.4 | 1.049 | 1.044 | 1.039 | 1.034 | 1.029 | 1.024 | |30.5 | 1.052 | 1.047 | 1.042 | 1.037 | 1.032 | 1.027 | |_____|_______|_______|_______|_______|_______|_______| _____________________________________________________ | | | | | THERMOMETER. | | BAR.|_______________________________________________| | | | | | | | | | | 58° | 60° | 62° | 64° | 66° | 68° | |_____|_______|_______|_______|_______|_______|_______| | | | | | | | | |28.5 | 0.954 | 0.949 | 0.944 | 0.939 | 0.934 | 0.929 | |28.6 | 0.958 | 0.953 | 0.947 | 0.943 | 0.938 | 0.932 | |28.7 | 0.961 | 0.956 | 0.951 | 0.946 | 0.941 | 0.936 | |28.8 | 0.964 | 0.959 | 0.954 | 0.949 | 0.944 | 0.939 | |28.9 | 0.968 | 0.963 | 0.958 | 0.953 | 0.948 | 0.942 | |29.0 | 0.971 | 0.966 | 0.961 | 0.956 | 0.951 | 0.946 | |29.1 | 0.975 | 0.969 | 0.964 | 0.959 | 0.954 | 0.949 | |29.2 | 0.978 | 0.973 | 0.968 | 0.963 | 0.958 | 0.952 | |29.3 | 0.981 | 0.976 | 0.971 | 0.966 | 0.961 | 0.956 | |29.4 | 0.985 | 0.980 | 0.975 | 0.969 | 0.964 | 0.959 | |29.5 | 0.988 | 0.983 | 0.978 | 0.973 | 0.968 | 0.962 | |29.6 | 0.992 | 0.986 | 0.981 | 0.976 | 0.971 | 0.966 | |29.7 | 0.995 | 0.990 | 0.985 | 0.980 | 0.974 | 0.969 | |29.8 | 0.998 | 0.993 | 0.988 | 0.983 | 0.978 | 0.972 | |29.9 | 1.002 | 0.997 | 0.991 | 0.986 | 0.981 | 0.976 | |30.0 | 1.005 | 1.000 | 0.995 | 0.990 | 0.985 | 0.979 | |30.1 | 1.009 | 1.003 | 0.998 | 0.993 | 0.988 | 0.983 | |30.2 | 1.012 | 1.007 | 1.002 | 0.996 | 0.991 | 0.986 | |30.3 | 1.015 | 1.010 | 1.005 | 1.000 | 0.995 | 0.989 | |30.4 | 1.019 | 1.014 | 1.008 | 1.003 | 0.998 | 0.993 | |30.5 | 1.022 | 1.017 | 1.012 | 1.006 | 1.001 | 0.996 | |_____|_______|_______|_______|_______|_______|_______| _____________________________________________ | | | | | THERMOMETER. | | BAR.|_______________________________________| | | | | | | | | | 70° | 72° | 74° | 76° | 78° | |_____|_______|_______|_______|_______|_______| | | | | | | | |28.4 | 0.921 | 0.915 | 0.910 | 0.905 | 0.900 | |28.5 | 0.924 | 0.919 | 0.914 | 0.908 | 0.903 | |28.6 | 0.927 | 0.922 | 0.917 | 0.912 | 0.906 | |28.7 | 0.931 | 0.925 | 0.920 | 0.915 | 0.909 | |28.8 | 0.934 | 0.929 | 0.924 | 0.918 | 0.913 | |28.9 | 0.937 | 0.932 | 0.927 | 0.921 | 0.916 | |29.0 | 0.941 | 0.935 | 0.930 | 0.925 | 0.919 | |29.1 | 0.944 | 0.939 | 0.933 | 0.928 | 0.923 | |29.2 | 0.947 | 0.942 | 0.937 | 0.931 | 0.926 | |29.3 | 0.950 | 0.945 | 0.940 | 0.935 | 0.929 | |29.4 | 0.954 | 0.949 | 0.943 | 0.938 | 0.932 | |29.5 | 0.957 | 0.952 | 0.947 | 0.941 | 0.936 | |29.6 | 0.960 | 0.955 | 0.950 | 0.944 | 0.939 | |29.7 | 0.964 | 0.959 | 0.953 | 0.948 | 0.942 | |29.8 | 0.967 | 0.962 | 0.957 | 0.951 | 0.946 | |29.9 | 0.970 | 0.965 | 0.960 | 0.954 | 0.949 | |30.0 | 0.974 | 0.968 | 0.963 | 0.958 | 0.952 | |30.1 | 0.977 | 0.972 | 0.966 | 0.961 | 0.955 | |30.2 | 0.980 | 0.975 | 0.970 | 0.964 | 0.959 | |30.3 | 0.984 | 0.978 | 0.973 | 0.968 | 0.962 | |30.4 | 0.987 | 0.982 | 0.976 | 0.971 | 0.965 | |30.5 | 0.990 | 0.985 | 0.980 | 0.974 | 0.969 | |_____|_______|_______|_______|_______|_______| For the detection of phosphine, Bergé's solution may be used. It is a "solution of 8 to 10 parts of corrosive sublimate in 80 parts of water and 20 parts of 30 per cent. hydrochloric acid." It becomes cloudy when gas containing phosphine is passed into it. It is, however, applied most conveniently in the form of Keppeler's test-papers, which have been described in Chapter V. Test-papers for phosphine, the active body in which has not yet been divulged, have recently been produced for sale by F. B. Gatehouse. The estimation of phosphine will usually require to be carried out either (1) on gas directly evolved from carbide in order to ascertain if the carbide in question yields an excessive proportion of phosphine, or (2) upon acetylene which is presumably purified, drawn either from the outlet of the purifier or from the service-pipes, with the object of ascertaining whether an adequate purification in regard to phosphine has been accomplished. In either case, the method of estimation is the same, but in the first, acetylene should be specially generated from a small representative sample of the carbide and led directly into the apparatus for the absorption of the phosphine. If the acetylene passes into the ordinary gasholder, the amount of phosphine in gas drawn off from the holder will vary from time to time according to the temperature and the degree of saturation of the water in the holder-tank with phosphine, as well as according to the amount of phosphine in the gas generated at the time. A method frequently employed for the determination of phosphine in acetylene is one devised by Lunge and Cedercreutz. If the acetylene is to be evolved from a sample of carbide in order to ascertain how much phosphine the latter yields to the gas, about 50 to 70 grammes of the carbide, of the size of peas, are brought into a half-litre flask, and a tap-funnel, with the mouth of its stem contracted, is passed through a rubber plug fitting the mouth of the flask. A glass tube passing through the plug serves to convey the gas evolved to an absorption apparatus, which is charged with about 75 c.c. of a 2 to 3 per cent. solution of sodium hypochlorite. The absorption apparatus may be a ten-bulbed absorption tube or any convenient form of absorption bulbs which subject the gas to intimate contact with the solution. If acetylene from a service-pipe is to be tested, it is led direct from the nozzle of a gas- tap to the absorption tube, the outlet of which is connected with an aspirator or the inlet of an experimental meter, by which the volume of gas passed through the solution is measured. But if the generating flask is employed, water is allowed to drop from the tap-funnel on to the carbide in the flask at the rate of 6 to 7 drops a minute (the tap-funnel being filled up from time to time), and all the carbide will thus be decomposed in 3 to 4 hours. The flask is then filled to the neck with water, and disconnected from the absorption apparatus, through which a little air is then drawn. The absorbing liquid is then poured, and washed out, into a beaker; hydrochloric acid is added to it, and it is boiled in order to expel the liberated chlorine. It is then usual to precipitate the sulphuric acid by adding solution of barium chloride to the boiling liquid, allowing it to cool and settle, and then filtering. The weight of barium sulphate obtained by ignition of the filter and its contents, multiplied by 0.137, gives the amount of sulphur present in the acetylene in the form of sulphuretted hydrogen. The filtrate and washings from this precipitate are rendered slightly ammoniacal, and a small excess of "magnesia mixture" is added; the whole is stirred, left to stand for 12 hours, filtered, the precipitate washed with water rendered slightly ammoniacal, dried, ignited, and weighed. The weight so found multiplied by 0.278 gives the weight of phosphorus in the form of phosphine in the volume of gas passed through the absorbent liquid. Objection may rightly be raised to the Lunge and Cedercreutz method of estimating the phosphine in crude acetylene on the ground that explosions are apt to occur when the gas is being passed into the hypochlorite solution. Also it must be borne in mind that it aims at estimating only the phosphorus which is contained in the gas in the form of phosphine, and that there may also be present in the gas organic compounds of phosphorus which are not decomposed by the hypochlorite. But when the acetylene is evolved from the carbide in proper conditions for the avoidance of appreciable heating it appears fairly well established that phosphorus compounds other than phosphine exist in the gas only in practically negligible amount, unless the carbide decomposed is of an abnormal character. Various methods of burning the acetylene and estimating the phosphorus in the products of combustion have, however been proposed for the purpose of determining the total amount of phosphorus in acetylene. Some of them are applicable to the simultaneous determination of the total sulphur in the acetylene, and in this respect become akin to the Gas Referees' method for the determination of the sulphur compounds in coal-gas. Eitner and Keppeler have proposed to burn the acetylene on which the estimation is to be made in a current of neat oxygen. But this procedure is rather inconvenient, and by no means essential. Lidholm liberated acetylene slowly from 10 grammes of carbide by immersing the carbide in absolute alcohol and gradually adding water, while the gas mixed with a stream of hydrogen leading to a burner within a flask. The flow of hydrogen was reduced or cut off entirely while the acetylene was coming off freely, but hydrogen was kept burning for ten minutes after the flame had ceased to be luminous in order to ensure the burning of the last traces of acetylene. The products of combustion were aspirated through a condenser and a washing bottle, which at the close were rinsed out with warm solution of ammonia. The whole of the liquid so obtained was concentrated by evaporation, filtered in order to remove particles of soot or other extraneous matter, and acidified with nitric acid. The phosphoric acid was then precipitated by addition of ammonium molybdate. J. W. Gatehouse burns the acetylene in an ordinary acetylene burner of from 10 to 30 litres per hour capacity, and passes the products of combustion through a spiral condensing tube through which water is dropped at the rate of about 75 c.c. per hour, and collected in a beaker. The burner is placed in a glass bell-shaped combustion chamber connected at the top through a right-angled tube with the condenser, and closed below by a metal base through which the burner is passed. The amount of gas burnt for one determination is from 50 to 100 litres. When the gas is extinguished, the volume consumed is noted, and after cooling, the combustion chamber and condenser are washed out with the liquid collected in the beaker and finally with distilled water, and the whole, amounting to about 400 c.c., is neutralised with solution of caustic alkali (if decinormal alkali is used, the total acidity of the liquid thus ascertained may be taken as a convenient expression of the aggregate amount of the sulphuric, phosphoric and silicic acids resulting from the combustion of the total corresponding impurities in the gas), acidified with hydrochloric acid, and evaporated to dryness with the addition towards the end of a few drops of nitric acid. The residue is taken up in dilute hydrochloric acid; and silica filtered off and estimated if desired. To the filtrate, ammonia and magnesia mixture are added, and the magnesium pyrophosphate separated and weighed with the usual precautions. Sulphuric acid may, if desired, be estimated in the filtrate, but in that case care must be taken that the magnesia mixture used was free from it. Mauricheau-Beaupré has elaborated a volumetric method for the estimation of the phosphine in crude acetylene depending on its decomposition by a known volume of excess of centinormal solution of iodine, addition of excess of standard solution of sodium thiosulphate, and titrating back with decinormal solution of iodine with a few drops of starch solution as an indicator. One c.c. of centinormal solution of iodine is equivalent to 0.0035 c.c. of phosphine. This method of estimation is quickly carried out and is sufficiently accurate for most technical purposes. In carrying out these analytical operations many precautions have to be taken with which the competent analyst is familiar, and they cannot be given in detail in this work, which is primarily intended for ordinary users of acetylene, and not for the guidance of analysts. It may, however, be pointed out that many useful tests in connexion with acetylene supply can be conducted by a trained analyst, which are not of a character to be serviceable to the untrained experimentalist. Among such may be named the detection of traces of phosphine in acetylene which has passed through a purifier with a view to ascertaining if the purifying material is exhausted, and the estimation of the amount of air or other diluents in stored acetylene or acetylene generated in a particular manner. Advice on these points should be sought from competent analysts, who will already have the requisite information for the carrying out of any such tests, or know where it is to be found. The analyses in question are not such as can be undertaken by untrained persons. The text-book on "Gas Manufacture" by one of the authors gives much information on the operations of gas analysis, and may be consulted, along with Hempel's "Gas Analysis" and Winkler and Lunge's "Technical Gas Analysis." APPENDIX DESCRIPTIONS OF A NUMBER OF ACETYLENE GENERATORS AS MADE IN THE YEAR 1909 (_The purpose of this Appendix is explained in Chapter IV., page 111, and a special index to it follows the general index at the end of this book._) AMERICA--CANADA. _Maker_: SICHE GAS CO., LTD., GEORGETOWN, ONTARIO. _Type_: Automatic; carbide-to-water. The "Siche" generator made by this firm consists of a water-tank _A_, having at the bottom a sludge agitator _N_ and draw-off faucet _O_, and rigidly secured within it a bell-shaped generating chamber _B_, above which rises a barrel containing the feed chamber _C_, surmounted by the carbide chamber _D_. The carbide used is granulated or of uniform size. In the generating chamber _B_ is an annular float _E_, nearly filling the area of the chamber, and connected, by two rods passing, with some lateral play, through apertures in the conical bottom of the feed chamber _C_, to the T-shaped tubular valve _F_. Consequently when the float shifts vertically or laterally the rods and valves at once move with it. The angle of the cone of the feed chamber and the curve of the tubular valve are based on the angle of rest of the size of carbide used, with the object of securing sensitiveness of the feed. The feed is thus operated by a very small movement of the float, and consequently there is but very slight rise and fall of the water in the generating chamber. Owing to the lateral play, the feed valve rarely becomes concentric with its seat. There is a cover _G_ over the feed valve _F_, designed to distribute the carbide evenly about the feed aperture and to prevent it passing down the hollow of the valve and the holes through which the connecting-rods pass. It also directs the course of the evolved gas on its way to the service-pipe through the carbide in the feed chamber _C_, whereby the gas is dried. The carbide chamber _D_ has at its bottom a conical valve, normally open, but closed by means of the spindle _H_, which is engaged at its upper end by the closing screw-cap _J_, which is furnished with a safelocking device to prevent its removal until the conical valve is closed and the hopper chamber _D_ thereby cut off from the gas-supply. The cap _J_, in addition to a leather washer to make a gas-tight joint when down, has a lower part fitting to make an almost gas-tight joint. Thus when the cap is off; the conical valve fits gas-tight; when it is on and screwed down it is gas-tight; and when on but not screwed down, it is almost gas-tight. Escape of gas is thus avoided. A special charging funnel _K_, shown in half-scale, is provided for inserting in place of the screw cap. The carbide falls from the funnel into the chamber _D_ when the chain is pulled. A fresh charge of carbide may be put in while the apparatus is in action. The evolved gas goes into the chamber _C_ through a pipe, with cock, to a dust-arrester _L_, which contains a knitted stocking lightly filled with raw sheep's wool through which the gas passes to the service- pipe. The dust-arrester needs its contents renewing once in one, two, or three years, according to the make of gas. The pressure of the gas is varied as desired by altering the height of water in the tank _A_. When cleaning the machine, the water must never be run below the top of the generating chamber. [Illustration: FIG. 24.--"SICHE" GENERATOR.] AMERICA--UNITED STATES. _Maker:_ J. B. COLT CO., 21 BARCLAY STREET, NEW YORK. _Type:_ Automatic; carbide-to-water. The "Colt" generator made by this firm comprises a carbide hopper mounted above a generating tank containing water, and an equalising bell gasholder mounted above a seal-pot having a vent-pipe _C_ communicating with the outer air. The carbide hopper is charged with 1/4 x 1/12 inch carbide, which is delivered from it into the water in the generating tank in small portions at a time through a double valve, which is actuated through levers connected to the crown of the equalising gasholder. As the bell of the gasholder falls the lever rotates a rock shaft, which enters the carbide hopper, and through a rigidly attached lever raises the inner plunger of the feed-valve. The inner plunger in turn raises the concentric outer stopper, thereby leaving an annular space at the base of the carbide hopper, through which a small delivery of carbide to the water in the generating tank then ensues. The gas evolved follows the course shown by the arrows in the figure into the gasholder, and raises the bell, thereby reversing the action of the levers and allowing the valve to fall of its own weight and so cut off the delivery of carbide. The outer stopper of the valve descends before the inner plunger and so leaves the conical delivery mouth of the hopper free from carbide. The inner plunger, which is capped at its lower end with rubber, then falls and seats itself moisture-tight on the clear delivery mouth of the hopper. The weight of the carbide in the hopper is taken by its sides and a projecting flange of the valve casing, so that the pressure of the carbide at the delivery point is slight and uniform. The outside of the delivery mouth is finished by a drip collar with double lip to prevent condensed moisture creeping upwards to the carbide in the hopper. A float in the generating tank, by its descent when the water falls below a certain level, automatically draws a cut off across the delivery mouth of the carbide hopper and so prevents the delivery of carbide either automatically or by hand until the water in the generating tank has been restored to its proper level. Interlocking levers, (11) and (12) in the figure, prevent the opening of the feed valve while the cap (10) of the carbide hopper is open for recharging the hopper. There is a stirrer actuated by a handle (9) for preventing the sludge choking the sludge cock. The gas passes into the gasholder through a floating seal, which serves the dual purpose of washing it in the water of the gasholder tank and of preventing the return of gas from the holder to the generating tank. From the gasholder the gas passes to the filter (6) where it traverses a strainer of closely woven cotton felt for the purpose of the removal of any lime. [Illustration: FIG. 25.--"COLT" GENERATING PLANT.] Drip pipes (30) and (31) connected to the inlet- and outlet-pipes of the gasholder are sealed in water to a depth of 6 inches, so that in the event of the pressure in the generator or gasholder rising above that limit the surplus gas blows through the seal and escapes through the vent-pipe _C_. There is also a telescopic blow-off (32) and (33), which automatically comes into play if the gasholder bell rises above a certain height. _Maker:_ DAVIS ACETYLENE CO., ELKHARDT, INDIANA. _Type:_ Automatic; carbide-to-water. The "Davis" generator made by this firm comprises an equalising bell gasholder with double walls, the inner wall surrounding a central tube rising from the top of the generating chamber, in which is placed a water-sealed carbide chamber with a rotatory feeding mechanism which is driven by a weight motor. The carbide falls from the chamber on to a wide disc from which it is pushed off a lump at a time by a swinging displacer, so arranged that it will yield in every direction and prevent clogging of the feeding mechanism. Carbide falls from the disk into the water of the generating chamber, and the evolved gas raises the bell and so allows a weighted lever to interrupt the action of the clockwork, until the bell again descends. The gas passes through a washer in the gasholder tank, and then through an outside scrubber to the service-pipe. There is an outside chamber connected by a pipe with the generating chamber, which automatically prevents over-filling with water, and also acts as a drainage chamber for the service- and blow-off-pipes. There is an agitator for the residuum and a sludge-cock through which to remove same. The feeding mechanism permits the discharge of lump carbide, and the weight motor affords independent power for feeding the carbide, at the same time indicating the amount of unconsumed carbide and securing uniform gas pressure. [Illustration: FIG. 26.--"DAVIS" GENERATOR.] _Maker:_ SUNLIGHT GAS MACHINE CO., 49 WARREN STREET, NEW YORK. _Type:_ Automatic; carbide-to-water. The "Omega" apparatus made by this firm consists of a generating tank containing water, and surmounted by a hopper which is filled with carbide of 1/4-inch size. The carbide is fed from the hopper into the generating tank through a mechanism consisting of a double oscillating cup so weighted that normally the feed is closed. The fall of the bell of the equalising gasholder, into which the gas evolved passes, operates a lever _B_, which rotates the weighted cup in the neck of the hopper and so causes a portion of carbide to fall into the water in the generating tank. The feed-cup consists of an upper cup into which the carbide is first delivered. It is then tipped from the upper cup into the lower cup while, at the same time, further delivery from the hopper is prevented. Thus only the portion of carbide which has been delivered into the lower cup is emptied at one discharge into the generator. There is a safety lock to the hopper cap which prevents the feeding mechanism coming into operation until the hopper cap is screwed down tightly. Provision is made for a limited hand-feed of carbide to start the apparatus. The gasholder is fitted with a telescoping vent-pipe, by which gas escapes to the open in the event of the bell being raised above a certain height. There is also an automatic cut-off of the carbide feed, which comes into operation it the gas is withdrawn too rapidly whether through leakage in the pipes or generating plant, or through the consumption being increased above the normal generating capacity of the apparatus. The gas evolved passes into a condensing or washing chamber placed beneath the gasholder tank and thence it travels to the gasholder. From the gasholder it goes through a purifier containing "chemically treated coke and cotton" to the supply-pipe. [Illustration: FIG. 27.--"OMEGA" GENERATOR.] 1 Vent-cock handle. 2 Residuum-cock handle. 3 Agitator handle. 4 Filling funnel. 5 Water overflow. 6 Hopper cap and lever. 7 Starting feed. 8 Rocker arm. 9 Feed connecting-rod. A Pawl. B Lever for working feed mechanism. C Guide frame. D Residuum draw-off cock. G Chain from hopper cap to feed mechanism. H Blow-off and vent-pipe connexion. I Gas outlet from generator. J Gas service-cock. K Filling funnel for gasholder tank. L Funnel for condensing chamber. M Gas outlet at top of purifier. N Guides on gas-bell. O Crosshead on swinging pawl. P Crane carrying pawl. Q Shaft connecting feed mechanism. R Plug in gas outlet-pipe. S Guide-frame supports. U Removable plate to clean purifier. Z Removable plate to expose feed-cups for cleaning same. AUSTRIA-HUNGARY _Maker:_ RICH. KLINGER, GUMPOLDSKIRCHEN, NEAR VIENNA. _Type:_ Non-automatic; carbide-to-water. The generating plant made by this firm consists of the generator _A_ which is supported in a concrete water and sludge tank _B_, a storage gasholder _J_, and purifiers _K_. In the top of the generator are guide-ways _F_, through each of which is passed a plunger _C_ containing a perforated cage charged with about 8 lb. of lump carbide. The plungers are supported by ropes passing over pulleys _D_, and when charged they are lowered through the guide-ways _F_ into the water in the tank _B_. The charge of carbide is thus plunged at once into the large body of water in the tank, and the gas evolved passes through perforations in the washer _G_ to the condenser _H_ and thence to the storage gasholder _J_. After exhaustion of the charge the plungers are withdrawn and a freshly charged cage of carbide inserted ready for lowering into the generating tank. There is a relief seal _f_ through which gas will blow and escape by a pipe _g_ to the open should the pressure within the apparatus exceed the depth of the seal, viz., about 9 inches. There is a syphon pot _N_ for the collection and withdrawal of condensed water. The sludge is allowed to accumulate in the bottom of the concrete tank _B_ until it becomes necessary to remove it at intervals of about three months. Water is added to the tank daily to replace that used up in the generation of the gas. The gas passes from the storage holder through one of the pair of purifiers _K_, with water-sealed lids, which are charged with a chemical preparation for the removal of phosphoretted hydrogen. This purifying material also acts as a desiccating agent. From the purifiers the gas passes through the meter _L_ to the service- pipes. [Illustration: FIG. 28.--KLINGER'S GENERATING PLANT.] BELGIUM. _Maker_: SOC. AN. DE L'ACÉTYLITHE, 65 RUE DU MARCHE, BRUSSELS. _Type_: Automatic; contact. The generating apparatus made by this firm uses, instead of ordinary carbide, a preparation known as "acétylithe," which is carbide treated specially with mineral oil, glucose and sugar. The object of using this treated carbide is to avoid the effects of the attack of atmospheric humidity or water vapour, which, with ordinary carbide, give rise to the phenomena of after-generation. The generator comprises a water-tank _A_ with conical base, a basket _C_ containing the treated carbide inserted within a cylindrical case _B_ which is open at the bottom and is surmounted by a cylindrical filter _D_. At starting, the tank _A_ is filled with water to the level _N N'_. The water rises within the cylindrical case until it comes in contact with the treated carbide, which thereupon begins to evolve gas. The gas passes through the filter _D_, which is packed with dry cotton-wool, and escapes through the tap _M_. As soon as the contained air has been displaced by gas the outlet of the tap _M_ is connected by a flexible tube to the pipe leading to a purifier and the service-pipe. When the tap _M_ is closed, or when the rate of evolution of the gas exceeds the rate of consumption, the evolved gas accumulates within the cylindrical case _B_ and begins to displace the water, the level of which within the case is lowered from _S S'_, first to _S1 S'1_ and ultimately to, say, _S2 S'2_. The evolution of gas is thereby gradually curtailed or stopped until more is required for consumption. The water displacement causes the water-level in the outer tank to rise to _N1 N'1_ and ultimately to, say _N2 N'2_. The lime formed by the decomposition of the carbide is loosened from the unattacked portion and taken more or less into solution as sucrate of lime, which is a soluble salt which the glucose or sugar in the treated carbide forms with lime. The solution is eventually run off through the cock _R_. The cover _T_ of the filter is screwed down on rubber packing until gas- tight. The purifier is charged with puratylene or other purifying material. [Illustration: FIG. 29.--ACÉTYLITHE GENERATOR.] _Maker_: L. DEBRUYNE, 22 PLACE MASUI, BRUSSELS. _Type_: (1) Automatic; carbide-to-water. The generating plant made by this firm, using granulated carbide, comprises an equalising gasholder _E_ alongside a generating tank _B_, which is surmounted by a closed carbide receptacle _A_ and a distributing appliance. The carbide receptacle is filled with granulated carbide and the lid _N_ screwed down; the carbide is then withdrawn from the base of the receptacle by the distributing appliance and discharged in measured quantities as required into the water in the generating tank. The distributing appliance is actuated by a weighted cord _H_ attached to the bell _I_ of the gasholder and discharges at each time a quantity of carbide only sufficient nearly to fill the gasholder with acetylene. The gas passes from the generator through the pipe _J_ and seal-pot _D_, or bypass _F_, to the gasholder. The generating tank is provided with a funnel _G_ for replacing the water consumed, a sludge-stirrer and a draw-off cock _L_, and a water-level cock _C_. The gas passes from the gasholder through a purifier _K_, charged with heratol, to the service-pipe. [Illustration: FIG. 30.--L. DEBRUYNE'S GENERATING PLANT FOR GRANULATED CARBIDE.] (2) Automatic; carbide-to-water. The "Debruyne" generator comprises an equalising bell gasholder _A_ placed alongside a generating tank _B_ containing water into which lump carbide is discharged as necessary from each in turn of a series of chambers mounted in a ring above the generating tank. The chambers are removable for refilling, and when charged are hermetically sealed until opened in turn above the shoot _C_, through which their contents are discharged into the generating tank. The carbide contained in each chamber yields sufficient gas nearly to fill the gasholder. The discharging mechanism is operated through an arm _E_ attached to the bell _G_ of the gasholder, which sets the mechanism in motion when the bell has fallen nearly to its lowest position. The lip _L_ serves for renewing the water in the generator, and the gas evolved goes through the pipe _K_ with tap _F_ to the gasholder. There is an eccentric stirrer for the sludge and a large-bore cock for discharging it. The gas passes from the gasholder through the pipe _J_ to the purifier _H_, charged with heratol, and thence to the service-pipe. [Illustration: FIG. 3l.--THE "DEBRUYNE" GENERATING PLANT FOR LUMP CARBIDE.] _Maker_: DE SMET VAN OVERBERGE, ALOST. _Type_: (1) Automatic; carbide-to-water. This generating apparatus comprises an equalising gasholder _A_ placed alongside a generating tank _B_, above which is mounted on a rotating spindle a series of chambers _C_, arranged in a circle, which are filled with carbide. The generating tank is closed at the top, but on one side there is a shoot _D_ through which the carbide is discharged from the chambers in turn into the water in the tank. The series of chambers are rotated by means of a cord passing round a pulley _E_ and having a weight _F_ at one end, and being attached to the bell of the gasholder at the other. When the bell falls, owing to the consumption of gas, to a certain low position, the carbide chamber, which has been brought by the rotation of the pulley over the shoot, is opened at the bottom by the automatic liberation of a catch, and its contents are discharged into the generating tank. The contents of one carbide chamber suffice to fill the gasholder to two-thirds of its total capacity. The carbide chambers after filling remain hermetically closed until the bottom is opened for the discharge of the carbide. There is a sludge-cock _G_ at the bottom of the generating tank. The gas passes from the gasholder through a purifier _H_, which is ordinarily charged with puratylene. [Illustration: FIG. 32.--AUTOMATIC GENERATING PLANT OF DE SMET VAN OVERBERGE.] (2) Non-automatic; carbide-to-water. This apparatus comprises a storage bell gasholder _J_ placed alongside a generating tank in the top of which is a funnel _E_ with a counter-weighted lever pivoted on the arm _B_. The base of the funnel is closed by a flap valve _C_ hinged at _D_. When it is desired to generate gas the counter-weight _A_ of the lever is raised and the valve at the bottom of the funnel is thereby opened. A charge of carbide is then tipped into the funnel and drops into the water in the generating tank. The valve is then closed and the gas evolved goes through the pipe _G_ to the gasholder, whence it passes through a purifier to the service-pipe. There is a sludge-cock on the generating tank. [Illustration: FIG. 33.--NON-AUTOMATIC GENERATING PLANT OF DE SMET VAN OVERBERGE.] _Maker_: SOC. AN. BELGE DE LA PHOTOLITHE, 2 RUE DE HUY, LIÉGE. _Type_: Automatic; carbide-to-water. The "Photolithe" generating plant made by this firm comprises an equalising bell gasholder _A_ in the tank _O_, alongside a generating tank _B_ which is surmounted by a carbide storage receptacle divided into a number of compartments. These compartments are fitted with flap bottoms secured by catches, and are charged with carbide. Through the middle of the storage receptacle passes a spindle, to the upper end of which is attached a pulley _b_. Round the pulley passes a chain, one end of which carries a weight _n_, while in the other direction it traverses guide pulleys and is attached to a loop on the crown of the gasholder bell. When the bell falls below a certain point owing to the consumption of gas, it pulls the chain and rotates the pulley _b_ and therewith an arm _d_, which liberates the catch supporting the flap-bottom of the next in order of the carbide compartments. The contents of this compartment are thereby discharged through the shoot _C_ into the generating tank _B_. The gas evolved passes through the cock _R_ and the pipe _T_ into the gasholder, the rise of the bell of which takes the pull off the chain and allows the weight at its other end to draw it up until it is arrested by the stop _f_. The arm _d_ is thereby brought into position to liberate the catch of the next carbide receptacle. The generating tank is enlarged at its base to form a sludge receptacle _E_, which is provided with a sludge draw-off cock _S_ and a hand-hole _P_. Between the generating tank proper and the sludge receptacle is a grid, which is cleaned by means of a rake with handle _L_. The gas passes from the gasholder through a purifier _H_ charged with puratylene, to the service-pipe. [Illustration: FIG. 34.--"PHOTOLITHE" GENERATING PLANT.] The same firm also makes a portable generating apparatus in which the carbide is placed in a basket in the crown of the bell of the gasholder. This apparatus is supplied on a trolley for use in autogenous soldering or welding. FRANCE. _Maker_: LA SOC. DES APPLICATIONS DE L'ACÉTYLÈNE, 26 RUE CADET, PARIS. _Type_: Automatic; carbide-to-water. The "Javal" generating plant made by this firm consists of an equalising bell gasholder _A_ in the tank _B_ with a series of buckets _D_, with removable bottoms _h_, mounted on a frame _F_ round the guide framing of the holder. Alongside the gasholder stands the generating tank _H_ with shoot _K_, into which the carbide discharged from the buckets falls. On top of the generator is a tipping water-bucket _I_ supplied with water through a ball cock. The bell of the gasholder is connected by chains _a_ and _c_, and levers _b_ and _d_ with an arm which, when the bell descends to a certain point, comes in contact with the catch by which the bottom of the carbide bucket is held in place, and, liberating the same, allows the carbide to fall into the shoot. When the bell rises, in consequence of the evolved gas, the ring of carbide buckets is rotated sufficiently to bring the next bucket over the shoot. Thus the buckets are discharged in turn as required through the rise and fall of the gasholder bell. [Illustration: FIG. 35.--"JAVAL" GENERATOR.] The carbide falling from the opened bucket strikes the end _i_ of the lever _k_, and thereby tips the water-bucket _I_ and discharges its contents into the shoot of the generator. The rise in the level of the water in the generator, due to the discharge of the water from the bucket _I_, lifts the float _L_ and therewith, through the attached rod and chain _u_, the ball _s_ of the valve _t_. The sludge, which has accumulated in the base _N_ of the generator from the decomposition of the previous portion of carbide, is thereby discharged automatically into a special drain. The discharge- valve closes automatically when the float _L_ has sunk to its original level. The gas evolved passes from the generator through the seal-pot _M_ and the pipe _r_ with cock _q_ into the gasholder, from which it passes through the pipe _x_; with condensation chamber and discharge tap _y_ into the purifier _R_, which is charged with heratol. _Maker_: L'HERMITE, LOUVIERS, EURE. _Type_: (1) Automatic; carbide-to-water. The generating plant known as "L'Éclair," by this firm comprises an equalising bell gasholder _A_ floating in an annular water-seal _N_, formed in the upper part of a generating tank _B_ into which carbide enters through the shoot _K_. Mounted at the side of the tank is the carbide delivery device, which consists of the carbide containers _J_ supported on an axis beneath the water-sealed cover _H_. The containers are filled with ordinary lump carbide when the cover _H_ is removed. The tappet _O_ attached to the bell of the gasholder come in contact with a pawl when the gasholder bell descends to a certain level and thereby rotates a pinion on the protruding end of the axis which carries the carbide containers _J_. Each time the bell falls and the tappet strikes the pawl, one compartment of the carbide containers discharges its contents down the shoot _K_ into the generating tank _B_. The gas evolved passes upwards and causes the bell _A_ to rise. The gas is prevented from rising into the shoot by the deflecting plates _G_. The natural level of the water in the generating tank, when the apparatus is in use, is shown by the dotted lines _L_. The lime sludge is discharged from time to time through the cock _E_, being stirred up by means of the agitator _C_ with handle _D_. When the sludge is discharged water is added through _M_ to the proper level. The gas evolved passes from the holder through the pipe with tap _F_ to the service-pipe. A purifier is supplied if desired. [Illustration: FIG. 36.--"L'ÉCLAIR," GENERATOR.] _References_ A Gasholder. B Generator. C Agitator. D Handle of agitator. E Sludge-cock. F Gas outlet. G Deflecting plates. H Cover. I Carbide. J Automatic distributor. K Shoot. L Water-level. M Water-inlet. N Water-seal. O Tappet. (2) Automatic; water-to-carbide; contact. A generating plant known as "L'Étoile" made by this firm. A tappet on the bell of an equalising gasholder depresses a lever which causes water to flow into a funnel, the outlet of which leads to a generating chamber containing carbide. _Maker_: MAISON SIRIUS, FR. MANGIAMELI & CO., 34 RUE DES PETITS- HÔTELS, PARIS. _Type_: (1) Automatic; carbide-to-water. The generating plant made by this firm comprises a drum-shaped carbide holder mounted above a generating tank, a condenser, a washer, an equalising gasholder, and a purifier. The drum _A_ is divided into eight chambers _a_ each closed by a fastening on the periphery of the drum. These chambers are packed with lump carbide, which is discharged from them in turn through the funnel _B_ into the generating tank, which is filled with water to the level of the overflow cock _b_. A deflecting plate _d_ in the tank distributes the carbide and prevents the evolved gas passing out by way of the funnel _B_. The gas evolved passes through the pipe _O_ into the condenser, which is packed with coke, through which the gas goes to the pipe _E_ and so to the washer _P_ through the water, in which it bubbles and issues by the pipe _G_ into the gasholder. The bell _L_ of the gasholder is connected by a chain _C_ to the axis of the drum _A_, on which is a pinion with pawl so arranged that the pull on the chain caused by the fall of the bell of the gasholder rotates the drum by 1/8 of a turn. The catch on the outside of the carbide chamber, which has thereby been brought to the lowest position, is at the same time freed, so that the contents of the chamber are discharged through the funnel _B_. The evolved gas causes the bell to rise and the drum remains at rest until, owing to the consumption of gas, the bell again falls and rotates the drum by another 1/8 of a turn. Each chamber of the drum holds sufficient carbide to make a volume of gas nearly equal to the capacity of the gasholder. Thus each discharge of carbide very nearly fills the gasholder, but cannot over-fill it. The bell is provided with a vent-pipe _i_, which comes into operation should the bell rise so high that it is on the point of becoming unsealed. From the gasholder the gas passes through the pipe _J_, with cock _e_, to the purifier, which is charged with frankoline, puratylene, or other purifying material, whence it passes to the pipe _N_ leading to the place of combustion. The generating tank is provided with a sludge-cock _g_, and a cleaning opening with lid _f_. This generating plant has been primarily designed for the use of acetylene for autogenous welding, and is made also mounted on a suitable trolley for transport for this purpose. [Illustration: FIG. 37.--"SIRIUS" GENERATOR.] (2) Automatic; carbide-to-water. A later design of generating plant, known as the Type G, also primarily intended for the supply of acetylene for welding, has the carbide store mounted in the crown of the bell of the equalising gasholder, to the framing of the tank of which are attached a purifier, charged with frankoline, and a safety water-seal or valve. The whole plant is mounted on a four-legged stand, and is provided with handles for carrying as a whole without dismounting. It is made in two sizes, for charges of 5-1/2 and 11 lb. of carbide respectively. GERMANY. _Maker_: KELLER AND KNAPPICH, G.m.b.H., AUGSBURG. _Type_: Non-automatic; carbide-to-water. The "Knappich" generating plant made by this firm embodies a generating tank, one-half of which is closed, and the other half of which is open at the top, containing water. A small drum containing carbide is attached by a clamp to the end of a lever which projects above the open half of the tank. The lever is fastened to a horizontal spindle which is turned through 180° by means of a counter-weighted lever handle. The carbide container is thus carried into the water within the closed half of the tank, and is opened automatically in transit. The carbide is thus exposed to the water and the evolved gas passes through a pipe from the top of the generating tank to a washer acting on the Livesey principle, and thence to a storage gasholder. The use of closed carbide containers in charging is intended to preclude the introduction of air into the generator, and the evolution and escape of gas to the air while the carbide is being introduced. Natural circulation of the water in the generating tank is encouraged with a view to the dissipation of heat and washing of the evolved gas. From the gasholder the gas passes in a downward direction through two purifiers arranged in series, charged with a material supplied under the proprietary name of "Carburylen." This material is stated to act as a desiccating as well as a purifying agent. The general arrangement of the plant is shown in the illustration. (Fig. 38). [Illustration: FIG. 38.--"KNAPPICH" GENERATING PLANT.] _Maker_: NORDISCHE AZETYLEN-INDUSTRIE; ALTONA-OTTENSEN. _Type_: Automatic; water-to-carbide; "drawer." The apparatus made by this firm consists of an equalising gasholder with bell _D_ and tank _E_, a water-tank _O_, and two drawer generators _C_ situated in the base of the gasholder tank. The water-supply from the tank _O_ through the pipe _P_ with valve _Q_ is controlled by the rise and fall of the bell through the medium of the weight _J_ attached to the bell. When the bell descends this weight rests on _K_ and so moves a counter-weighted lever, which opens the valve _Q_. The water then flows through the nozzle _B_ into one division of the funnel _A_ and down the corresponding pipe to one of the generators. The generators contain trays with compartments intended to be half filled with carbide. The gas evolved passes up the pipe _T_ and through the seal _U_ into the bell of the gasholder. There is a safety pipe _F_, the upper end of which is carried outside the generator house. From the gasholder the gas is delivered through the cock _M_ to a purifier charged with a special purifying material mixed with cork waste and covered with wadding. There is a drainage cock _N_ at the base of the purifier. The nozzle _B_ of the water-supply pipe is shifted to discharge into either compartment of the funnel _A_, according to which of the two generators is required to be in action. The other generator may then be recharged without interfering with the continuous working of the plant. [Illustration: FIG. 39.--GENERATING PLANT OF THE NORDISCHE AZETYLEN- INDUSTRIE.] GREAT BRITAIN AND IRELAND. _Maker:_ THE ACETYLENE CORPORATION OF GREAT BRITAIN LTD., 49 VICTORIA STREET, LONDON, S.W. _Type:_ (1) Automatic; water-to-carbide; contact, superposed pans. The "A1" generating plant made by this firm comprises a bell gasholder, with central guide, standing alongside the generator. The generator consists of a rectangular tank in which is a generating chamber having a water-sealed lid with pressure test-cock _I_. Into the generating chamber fit a number of pans _J_, which are charged with carbide. Water is supplied to the generating chamber from an overhead tank _B_ through the starting tap _D_ and the funnel _E_. It flows out of the supply-pipe near the top of the generating chamber through a slot in the side of the pipe facing the corner of the chamber, so that it runs down the latter without splashing the carbide in the upper pans. It enters first the lowest carbide pan through the perforations, which are at different levels in the side of the pan. It thus attacks the carbide from the bottom upwards. The evolved gas passes from the generating chamber through a pipe opening near the top of the same to the washer _A_, which forms the base of the generating tank. It bubbles through the water in the washer, which therefore also serves as a water-seal, and passes thence to the gasholder. On the bell of the gasholder is an arm _C_ which, when the holder descends nearly to its lowest point, depresses the rod _C_, which is connected by a chain to a piston in the outlet-pipe from the water-tank _B_. The fall of the gasholder thereby raises the piston and allows water to flow out of the tank _B_ through the tap _D_ to the funnel _E_. The generating tank is connected by a pipe, with tap _G_, with the washer _A_, and the water in the generating tank is run off through this pipe each time the generating chamber is opened for recharging, thereby flushing out the washer _A_ and renewing the water in the same. There is a sludge discharging tap _F_. With a view to the ready dissipation of the heat of generation the generating chamber is made rectangular and is placed in a water-tank as described. Some of the heat of generation is also communicated to the underlying washer and warms the water in it, so that the washing of the gas is effected by warm water. Water condensing in the gasholder inlet-pipe falls downwards to the washer. There is a water lip _H_ by which the level of the water in the washer is automatically kept constant. The gasholder is provided with a safety-pipe _K_, which allows gas to escape through it to the open before the sides of the holder become unsealed, should the holder for any reason become over-filled. The holder is of a capacity to take the whole of the gas evolved from the carbide in one pan, and the water- tank _B_ holds just sufficient water for the decomposition of one charge of the generator. From the gasholder the gas passes through a purifier, which is ordinarily charged with "Klenzal," and a baffle-box for abstraction of dust, to the service-pipe. With plants intended to supply more than forty lights for six hours, two or more generating chambers are employed, placed in separate compartments of one rectangular generating tank. The water delivery from the water-tank _B_ then takes place into a trough with outlets at different levels for each generating chamber. By inspection of this trough it may be seen at once whether the charge in any generating chamber is unattacked, in course of attack, or exhausted. [Illustration: FIG. 40.--THE "A1" GENERATING PLANT OF THE ACETYLENE CORPORATION OF GREAT BRITAIN, LTD.] (2) Automatic; water-to-carbide; contact. The same firm also makes the "Corporation Flexible-Tube Generator," which is less costly than the "A1" (_vide supra_). The supply of water to the generating vessels takes place from the tank of the equalising bell gasholder and is controlled by a projection on the bell which depresses a flexible tube delivering into the generating vessels below the level of the water inlet to the tube. (3) Automatic; water-to-carbide; "drawer." The same firm also makes a generator known as the "A-to-Z," which is less costly than either of the above. In it water is supplied from the tank of a bell gasholder to a drawer type of generator placed in the base of the gasholder tank. The supply of water is controlled by an external piston- valve actuated through the rise and fall of the bell of the gasholder. The flow of water to the generator is visible. _Maker_: THE ACETYLENE GAS AND CARBIDE OF CALCIUM CO., PONTARDAWE, R.S.O., GLAM. _Type_: Automatic; water-to-carbide; flooded compartment. The "Owens" generator made by this firm comprises an equalising bell gasholder alongside which are placed two or more inclined generating cylinders. The front lower end of each cylinder is fitted with a lid which is closed by a screw clamp. There is inserted in each cylinder a cylindrical trough, divided into ten compartments, each of which contains carbide. Water is supplied to the upper ends of the cylinders from a high-level tank placed at the back of the gasholder. In the larger sizes the tank is automatically refilled from a water service through a ball-cock. The outlet-valve of this tank is operated through a counter- weighted lever, the unweighted end of which is depressed by a loop, attached to the crown of the gasholder bell, when the bell has nearly reached its lowest position. This action of the bell on the lever opens the outlet-valve of the tank and allows water to flow thence into one of the generating cylinders. It is discharged into the uppermost of the compartments of the carbide trough, and when the carbide in that compartment is exhausted it flows over the partition into the next compartment, and so on until the whole trough is flooded. The gas passes from the generating cylinders through a water-seal and a baffle plate condenser placed within the water link of the gasholder to the bell of the latter. There is a water seal on the water supply-pipe from the tank to the generators, which would be forced should the pressure within the generators for any reason become excessive. There is also a sealed vent- pipe which allows of the escape of gas from the holder to the open should the holder for any reason be over filled. The gas passes from the holder through a purifier charged with "Owens" purifying material to the service pipe. The plant is shown in Fig 41. [Illustration: FIG. 41.--"OWENS" GENERATOR.] _Maker_ ACETYLENE ILLUMINATING CO, LTD, 268-270 SOUTH LAMBETH ROAD, LONDON, SW _Type_ (1) Non automatic, carbide to water The generator _A_ of this type made by this firm is provided with a loading box _B_, with gas tight lid, into which the carbide is put. It is then discharged by moving a lever which tilts the hinged bottom _D_ of the box _B_, and so tips the carbide through the shoot _E_ on to the conical distributor _F_ and into the water in the generating chamber. There is a sludge cock _G_ at the base of the generator. Gas passes as usual from the generator to a washer and storage gasholder. Heratol is the purifying material supplied. [Illustration: FIG. 42.--CARBIDE-TO-WATER GENERATOR OF THE ACETYLENE ILLUMINATING CO., LTD.] (2) Non-automatic; water-to-carbide; contact. The generator _A_ is provided with a carbide container with perforated base, and water is supplied to it from a delivery-pipe through a scaled overflow. The gas evolved passes through the pipe _E_ to the washer _B_, which contains a distributor, and thence to the storage gasholder _G_. There is a sludge-cock _F_ at the base of the generator. From the gasholder the gas passes through the purifier _D_, charged with heratol, to the service-pipe. [Illustration: FIG. 43.--WATER-TO-CARBIDE GENERATING PLANT OF THE ACETYLENE ILLUMINATING CO., LTD.] _Maker_: THE ALLEN CO., 106 VICTORIA STREET, LONDON, S.W. _Type_: Automatic; water-to-carbide; contact, superposed trays. The generating plant made by this firm comprises an equalising bell gasholder, from the tank of which water is supplied through a flexible tube to the top of a water-scaled generating chamber in which is a vertical cylinder containing a cage packed with carbide. The open end of the flexible tube is supported by a projection from the bell of the gasholder, so that as the bell rises it is raised above the level of the water in the tank and so ceases to deliver water to the generator until the bell again falls. The water supplied flows by way of the water-seal of the cover of the generating chamber to the cylinder containing the carbide cage. Larger sizes have two generating chambers, and the nozzle of the water delivery-pipe may be switched over from one to the other. There is an overflow connexion which brings the second chamber automatically into action when the first is exhausted. One chamber may be recharged while the other is in action. Spare cylinders and cages are provided for use when recharging. There is a cock for drawing off water condensing in the outlet-pipe from the gasholder. The gas passes from the holder to the lower part of a purifier with water-scaled cover, through the purifying material in which it rises to the outlet leading to the service-pipe. Purifying material under the proprietary name of the "Allen" compound is supplied. The plant is shown in Fig. 44. [Illustration: FIG. 44.--"ALLEN" FLEXIBLE-TUBE GENERATOR.] Maker: THE BON-ACCORD ACETYLENE GAS CO., 285 KING STREET, ABERDEEN. Type: Automatic; water-to-carbide; contact, superposed trays. The "Bon Accord" generating plant made by this firm comprises an equalising displacement gasholder _B_ immersed in a water-tank _A_. Alongside the tank are placed two water-jacketed generating chambers _G1_ and _G2_ containing cages _K_ charged with carbide. Water passes from within the gasholder through the water inlet- pipes _L1 L2_, the cock _H_, and the pipes _F1 F2_ to the generating chambers, from which the gas evolved travels to the holder _B_, in which it displaces water until the water-level falls below the mouths of the pipes _L1_ and _L2_, and so cuts off the supply of water to the generating chambers. The gas passes from the holder _B_ through the pipe with outlet-cock _T_ to a washer containing an acid solution for the neutralisation of ammonia, then through a purifier containing a "special mixture of chloride of lime." After that through a tower packed with lime, and finally through a pressure regulator, the outlet of which is connected to the service-pipe. There is an indicator _I_ to show the amount of gas in the holder. One generator may be charged while the other is in action. [Illustration: FIG. 45.--"BON-ACCORD" GENERATOR.] _Maker_: FREDK. BRABY AND CO., LTD., ASHTON GATE WORKS, BRISTOL; AND 352-364 EUSTON ROAD, LONDON. _Type:_ (I) Automatic; carbide-to-water. The "A" type of generator made by this firm comprises an equalising bell gasholder, round the bell of which are arranged a series of buckets which are charged with carbide. Those buckets are discharged in turn as the bell falls from time to time through a mechanism operated by a weight suspended from a wire cord on a revolving spindle. The carbide is discharged on to a different spot in the generating tank from each bucket. There is a cock for the periodical removal of sludge. Gas passes through a purifier charged with puratylene to the service-pipe. The disposition of the parts of the plant and the operating mechanism arc shown in the accompanying figure, which represents the generating apparatus partly in elevation and partly in section. The carbide buckets (1) are loosely hooked on the flat ring (2) bolted to the gasholder tank (3). The buckets discharge through the annular water-space (4) between the tank and the generator (5). The rollers (6), fitted on the generator, support a ring (7) carrying radial pins (8) projecting outwards, one pin for each bucket. The ring can travel round on the rollers. Superposed on the ring is a tray (9) closed at the bottom except for an aperture beneath the throat (11), on which is mounted an inclined striker (12), which strikes the projecting tongues (1_a_) of the lids of the buckets in turn. There is fixed to the sides of the generator a funnel (13) with open bottom (13_a_) to direct the carbide, on to the rocking grid (14) which is farther below the funnel than appears from the figure. Gas passing up behind the funnel escapes through a duct (15) to the gasholder. The ring (7) is rotated through the action of the weight (16) suspended by the chain or rope (17) which passes round the shaft (18), which is supported by the bracket (19) and has a handle for winding up. An escapement, with upper limb (20_a_) and lower limb (20_b_), is pivotally centred at (21) in the bracket (19) and normally restrains the turning of the shaft by the weight. There is a fixed spindle (24) supported on the bracket (23)--which is fixed to the tank or one of the guide-rods--having centred on it a curved bar or quadrant (25) running loose on the spindle (24) and having a crank arm (26) to which is connected one end of a rod (27) which, at the other end, is connected to the arm (28) of the escapement. The quadrant bears at both extremities against the flat bar (29) when the bell (22) is sufficiently raised. The bar (29) extends above the bell and carries an arm (30) on which is a finger (30_a_). There is fixed on the shaft (18) a wheel (31), with diagonal divisions or ways extending from side to side of its rim, and stop-pins (32) on one side at each division. A clutch prevents the rotation of the wheel during winding up. [Illustration: FIG. 46.--THE "A" GENERATOR OF FRED K. BRABY AND CO., LTD.] (2) Automatic; water-to-carbide; contact, superposed trays. The type "B" generator made by this firm comprises an equalising bell gasholder, a crescent-shaped feed water-tank placed on one side of the gasholder, and mechanism for controlling a tap on the pipe by which the feed water passes to a washer whence it overflows through a seal into a horizontal generating chamber containing cells packed with carbide. The mechanism controlling the water feed embodies the curved bar (25), connecting-rod (27) and flat guide-bar (29) as used for controlling the carbide feed in the "A" type of generator (Fig. 46). When the bell descends water is fed into the washer, and the water-level of the seal is thus automatically maintained. The gas evolved passes through a pipe, connecting the seal on the top of the generating chamber with the washer, into the gasholder. Plants of large size have two generating chambers with connexions to a single washer. _Maker:_ THE DARGUE ACETYLENE GAS CO., 57 GREY STREET, NEWCASTLE-ON- TYNE. _Type:_ Automatic; water-to-carbide; "drawer." The "Dargue" acetylene generator made by this firm comprises an equalising bell gasholder _B_ floating in a water-tank _A_, which is deeper than is necessary to submerge the bell of the gasholder. In the lower part of this tank are placed two or more horizontal generating chambers which receive carbide-containing trays divided by partitions into a number of compartments which are half filled with carbide. Water is supplied from the gasholder tank through the tap _E_ and pipe _F_ to the generating chambers in turn. It rises in the latter and floods the first compartment containing carbide before gaining access to the second, and so on throughout the series of compartments. As soon as the carbide in the first generating chamber is exhausted, the water overflows from it through the pipe with by-pass tap _J_ to the second generating chamber. The taps _G_ and _H_ serve to disconnect one of the generating chambers from the water-supply during recharging or while another chamber is in action. The gas evolved passes from each generating chamber through a pipe _L_, terminating in the dip-pipe _M_, which is provided with a baffle-plate having very small perforations by which the stream of gas is broken up, thereby subjecting it to thorough washing by the upper layers of water in the gasholder tank. The washed gas, which thus enters the gasholder, passes from it through the pipe _N_ with main cock _R_ to the service- pipes. The water-supply to the generator is controlled through the tap _E_, which is operated by a chain connected to an arm attached to the bell of the gasholder. The water in the gasholder tank is accordingly made to serve for the supply of the generating chambers, for the washing of the gas, and as a jacket to the generating chambers. The heat evolved by the decomposition of the carbide in the latter creates a circulation of the water, ensuring thereby thorough mixing of the fresh water, which is added from time to time to replace that removed for the decomposition of the carbide, with the water already in the tank. Thus the impurities acquired by the water from the washing of the gas do not accumulate in it to such an extent as to render it necessary to run off the whole of the water and refill, except at long intervals. A purifier, ordinarily charged with puratylene, is inserted in many cases after the main cock _R_. The same firm makes an automatic generator on somewhat similar lines, specially designed for use in autogenous welding, the smaller sizes of which are readily portable. [Illustration: FIG. 47.--"DARGUE" GENERATOR.] _Maker_: J. AND J. DRUMMOND, 162 MARKET STREET, ABERDEEN. _Type_: Automatic; water-to-carbide; contact. The generating plant made by this firm comprises two or more generating vessels _B_ in which carbide is contained in removable cases perforated at different levels. Water is supplied to these generating vessels, entering them at the bottom, from an elevated tank _A_ through a pipe _C_, in which is a tap _F_ connected by a lever and chain _L_ with the bell _G_ of the equalising gasholder _H_, into which the evolved gas passes. The lever of the tap _F_ is counter-weighted so that when the bell _G_ descends the tap is opened, and when the bell rises the tap is closed. The gas passes from the generating chambers _B_ through the pipe _D_ to the washer-cooler _E_ and thence to the gasholder. From the latter it passes through the dry purifier _J_ to the service-pipe. The gasholder bell is sealed in oil contained in an annular tank instead of in the usual single-walled tank containing water. The purifying material ordinarily supplied is puratylene. The apparatus is also made to a large extent in a compact form specially for use on board ships. [Illustration: FIG. 48.--J. AND J. DRUMMOND'S GENERATING PLANT.] _Agents_: FITTINGS, LTD., 112 VICTORIA STREET, S.W. _Type_: Automatic; carbide-to-water. The "Westminster" generator supplied by this firm is the "Davis" generator described in the section of the United States. The rights for the sale of this generator in Great Britain are held by this firm. _Maker_: LOCKERBIE AND WILKINSON, TIPTON, STAFFS. _Type_: (1) Automatic; water-to-carbide; contact, superposed trays. The "Thorscar" generator of this firm comprises an equalising gasholder, the gas-space of the bell _B_ of which is reduced by conical upper walls. When the bell descends and this lining enters the water in the tank _A_ the displacement of water is increased and its level raised until it comes above the mouths of the pipes _E_, through which a portion then flows to the generators _D_. The evolution of the gas in the latter causes the bell to rise and the conical lining to be lifted out of the water, the level of which thereupon falls below the mouths of the pipes _E_ in consequence of the reduced displacement of the bell. The supply of water to the generators is thus cut off until the bell again falls and the level of the water in the tank is raised above the mouths of the pipes _E_. The generating chambers _D_ are provided with movable cages _F_ in which the carbide is arranged on trays. The gas evolved travels through a scrubbing-box _G_ containing charcoal, and the pipe _J_ with drainage-pipe _P_ to the water-seal or washer _K_ inside the holder, into which it then passes. The outlet-pipe for gas from the holder leads through the condensing coil _L_ immersed in the water in the tank to the condensed water-trap _N_, and thence by the tap _Q_ to the supply-pipe. The generating chambers are water-jacketed and provided with gauge-glasses _H_ to indicate when recharging is necessary, and also with sludge-cocks _M_. The object of the displacement cone in the upper part of the bell is to obtain automatic feed of water to the carbide without the use of cocks or movable parts. There is a funnel- shaped indicator in front of the tank for regulating the height of water to a fixed level, and also an independent purifier, the purifying material or which is supplied under the proprietary name of "Thorlite." [Illustration: FIG. 49.--"THORSCAR" GENERATOR.] (2) Non-automatic; water-to-carbide; "drawer." This generating plant, the "Thorlite," comprises a water-tank _A_ from which water is admitted to the drawer generating chambers _B_, one of which may be recharged while the other is in operation. The gas evolved passes through a seal _C_ to the gasholder _D_, whence it issues as required for use through the purifier _E_ to the supply-pipe. For the larger sixes a vertical generating chamber is used. The purifier and purifying material are the same as for the automatic plant of the same firm. [Illustration: FIG. 50.--"THORLITE" GENERATING PLANT.] _Maker_: THE MANCHESTER ACETYLENE GAS CO., LTD., ACRE WORKS, CLAYTON, MANCHESTER. _Type_: Automatic; water-to-carbide; "drawer." The plant made by this firm comprises an equalising gasholder _A_ from the tank of which water is supplied to generating cylinders _B_ placed at the side of the tank, the number of which varies with the capacity of the plant. The cylinders receive tray carbide-containers divided into compartments perforated at different levels so that they are flooded in turn by the inflowing water. A weight _C_ carried by a chain _D_ from one end of a lever _E_ pivoted to the framing of the gasholder is supported by the bell of the gasholder when the latter rises; but when the holder falls the weight _C_, coming upon the lever _E_, raises the rod _F_, which thereupon opens the valve _G_, which then allows water to flow from the gasholder tank through the pipe _H_ to one of the generating cylinders. When the carbide in the first cylinder is exhausted, the water passes on to a second. One generating cylinder may be recharged while another is in action. The rising of the holder, due to the evolved gas, causes the bell to support the weight _C_ and thus closes the water supply-valve _G_. The gas evolved passes through vertical condensers _J_ into washing- boxes _K_, which are placed within the tank. The gas issues from the washing-boxes into the gasholder bell, whence it is withdrawn through the pipe _L_ which leads to the purifier. Puratylene is the purifying material ordinarily supplied by this firm. [Illustration: FIG. 51.--GENERATING PLANT OF THE MANCHESTER ACETYLENE GAS CO., LTD.] _Maker:_ R,. J. MOSS AND SONS, 98 SNOW HILL, BIRMINGHAM. _Type:_ (1) Automatic; water-to-carbide; superposed trays. The "Moss" generator, "Type A," made by this firm comprises an equalising gasholder, four, three, or two generating chambers, and an intermediate water-controlling chamber. Each generating chamber consists of a frame in which are arranged about a central tube trays half filled with carbide, having water inlet-holes at several different levels, and each divided into two compartments. Over this frame is put a bell-shaped cover or cap, and the whole is placed in an outer tank or bucket, in the upper part of which is a water inlet-orifice. The water entering by this orifice passes down the outside of the bell, forming a water-seal, and rises within the bell to the perforations in the carbide trays from the lowest upwards, and so reaches the carbide in successive layers until the whole has been exhausted. The gas evolved passes through the central tube to a water- seal and condensing tank, through which it escapes to the controlling chamber, which consists of a small water displacement chamber, the gas outlet of which is connected to the equalising gasholder. The bell of the equalising gasholder is weighted or balanced so that when it rises to a certain point the pressure is increased to a slight extent and consequently the level of the water in the displacement controlling chamber is lowered. In this chamber is a pipe perforated at about the water-level, so that when the level is lowered through the increased pressure thrown by the rising gasholder the water is below the perforations and cannot enter the pipe. The pipe leads to the water inlet-orifices of the generating tanks and when the equalising gasholder falls, and so reduces the pressure within the controlling chamber, the water in the latter rises and flows through the pipe to the generating tanks. The water supplied to the carbide is thus under the dual control of the controlling chamber and of the differential pressure within the generating tank. The four generators are coupled so that they come into action in succession automatically, and their order of operation is naturally reversed after each recharging. An air-cock is provided in the crown of the bell of each generator and, in case there should be need of examination when charged, cocks are provided in other parts of the apparatus for withdrawing water. There is a sludge-cock on each generator. The gas passes from the equalising gasholder through a purifier, for which the material ordinarily supplied is puratylene. [Illustration: FIG. 52.--"MOSS TYPE A" GENERATOR.] The "Moss Type B" generator is smaller and more compact than "Type A." It has ordinarily only two generating chambers, and the displacement water controlling chamber is replaced by a bell governor, the bell of which is balanced through a lever and chains by a weight suspended over the bell of the equalising gasholder, which on rising supports this counter-weight and so allows the governor bell to fall, thereby cutting off the flow of water to the generating chambers. [Illustration: FIG 53.--"MOSS TYPE B" GENERATOR.] The "Moss Type C" generator is smaller than either "Type A" or "B," and contains only one generating chamber, which is suspended in a pocket in the crown of the equalising gasholder. Water enters through a hole near the top of the bucket of the generating chamber, when it descends with the holder through the withdrawal of gas from the latter. [Illustration: FIG 54.--"MOSS TYPE C" GENERATOR.] (2) Semi-automatic; water-to-carbide; superposed trays. The "Moss Semi-Non-Auto" generating plant resembles the automatic plant described above, but a storage gasholder capable of holding the gas evolved from one charging of the whole of the generating chambers is provided in place of the equalising gasholder, and the generation of gas proceeds continuously at a slow rate. The original form of the "Acetylite" generator (_vide infra_) adapted for lantern use is also obtainable of R. J. Moss and Sons. _Maker:_ WM. MOYES AND SONS, 115 BOTHWELL STREET, GLASGOW. _Type:_ Automatic; carbide-to-water. The "Acetylite" generator made by this firm consists of an equalising gasholder and one or more generating tanks placed alongside it. On the top of each generating tank is mounted a chamber, with conical base, charged with granulated carbide 1/8 to 1/2 inch in size. There is an opening at the bottom of the conical base through which passes a rod with conical head, which, when the rod is lowered, closes the opening. The rod is raised and lowered through levers by the rise and fall of the bell of the equalising gasholder, which, when it has risen above a certain point, supports a counter-weight, the pull of which on the lever keeps the conical feed-valve open. The gas evolved in the generating tanks passes through a condensing chamber situated at the base of the tank into the equalising gasholder and so automatically controls the feed of carbide and the evolution of gas according to the rate of withdrawal of the gas from the holder to the service-pipes. The water in the gasholder tank acts as a scrubbing medium to the gas. The generating tanks are provided with sludge-cocks and a tap for drawing off condensed water. The gas passes from the equalising gasholder, through a purifier and dryer charged with heratol or other purifying material to the service-pipes. The original form of the "Acetylite" generator is shown in elevation and vertical section in Fig. 55. Wm. Moyes and Sons now make it also with a detached equalising gasholder connected with the generator by a pipe in which is inserted a lever cock actuated automatically through a lever and cords by a weight above the bell of the gasholder. Some other changes have been made with a view to securing constancy of action over long periods and uniformity of pressure. In this form the apparatus is also made provided with a clock-work mechanism for the supply of lighthouses, in which the light is flashed on periodically. The flasher is operated through a pilot jet, which serves to ignite the gas at the burners when the supply is turned on to them at the prescribed intervals by the clock- work mechanism. [Illustration: FIG. 55.--"ACETYLITE" GENERATOR.] _Maker_: THE PHÔS CO., 205 AND 207 BALLS POND ROAD, LONDON, N. _Type_: Non-automatic; water-to-carbide; drip. The type "E" generator made by this firm consists of a generating chamber placed below a water chamber having an opening with cap _E_ for refilling. The generating chamber in closed by a door _B_, with rubber washer _C_, held in position by the rod _A_, the ends of which pass into slots, and the screw _A'_. The movable carbide chamber _D_ has its upper perforated part half filled with carbide, which is pressed upwards by a spring _D'_. The carbide chamber when filled is placed in the generating chamber, which is closed, and the lever _F_ of one of the taps _F'_ is turned from "off" to "on," whereupon water drips from the tank on to the carbide. The evolution of gas is stopped by reversing the lever of the tap. The second tap is provided for use when the evolution of gas, through the water-supply from the first tap, has been stopped and it is desired to start the apparatus without waiting for water from the first tap to soak through a layer of spent carbide. The two taps are not intended for concurrent use. The evolved gas passes through a purifier containing any suitable purifying material to the pipes leading to the burners. [Illustration: FIG. 56.--"PHÔS TYPE E" GENERATOR.] _Maker:_ ROSCO ACETYLENE COMPANY, BELFAST. _Type:_ Non-automatic; carbide-to-water The "Rosco" generating plant made by this firm comprises a generating tank _A_ which is filled with water to a given level by means of the funnel-mouthed pipe _B_ and the overflow _O_. On the top of the water-sealed lid of the generating tank is mounted the carbide feed-valve _L_, which consists of a hollow plug-tap with handle _M_. When the handle _M_ is turned upwards the hollow of the tap can be filled from the top of the barrel with carbide. On giving the tap a third of a turn the hollow of the plug is cut off from the outer air and is opened to the generating tank so that the carbide contained in it is discharged over a distributor _E_ on to the tray _N_ in the water in the generating tank. The gas evolved passes through the scrubber and seal-pot _J_ to the storage gasholder _Q_. From the latter the gas passes through the dry purifier _T_ to the service-pipe. A sludge- cock _P_ is provided at the bottom of the generating tank and is stated to be available for use while generation of gas is proceeding. The purifying material ordinarily supplied is "Roscoline." [Illustration: FIG. 57.--"ROSCO" GENERATING PLANT.] _Maker_: THE RURAL DISTRICTS GAS LIGHT CO., 28 VICTORIA STREET, S.W. _Type_: Automatic; water-to-carbide; contact, superposed trays. The "Signal-Arm" generating apparatus made by this firm comprises a bell gasholder _A_, from the tank _B_ of which water is supplied through a swivelled pipe _C_ to a generating chamber _D_. One end of the swivelled pipe is provided with a delivery nozzle, the other end is closed and counter-weighted, so that normally the open end of the pipe is raised above the level of the water in the tank. A tappet _E_ on the bell of the gasholder comes into contact with, and depresses, the open end of the swivelled pipe when the bell falls below a certain point. As soon as the open end of the swivelled pipe has thus been lowered below the level of the water in the tank, water flows through it into the funnel-shaped mouth _F_ of a pipe leading to the bottom of the generating chamber. The latter is filled with cages containing carbide, which is attacked by the water rising in the chamber. The gas evolved passing into and raising the bell of the gasholder causes the open end of the swivelled pipe to rise, through the weight of the counterpoise _G_, above the level of the water in the tank and so cuts off the supply of water to the generating chamber until the bell again descends and depresses the swivelled pipe. The tappet on the bell also displaces a cap _H_ which covers the funnel-shaped mouth of the pipe leading to the generating chamber, which cap, except when the swivelled supply-pipe is being brought into play, prevents any extraneous moisture or other matter entering the mouth of the funnel. Between the generating chamber and the gasholder is a three-way cock _J_ in the gas connexion, which, when the gasholder is shut off from the generator, brings the latter into communication with a vent-pipe _K_ leading to the open. The gas passes from the holder to a chamber _L_ under grids packed with purifying material, through which it passes to the outlet of the purifier and thence to the service-pipe. Either heratol or chloride of lime is used in the purifier, the lid of which, like the cover of the generator, is water-sealed. [Illustration: FIG. 58.--"SIGNAL-ARM" GENERATING PLANT.] _Maker_: ST. JAMES' ILLUMINATING CO., LTD., 3 VICTORIA STREET, LONDON, S.W. _Type_: (1) Automatic; water-to-carbide; contact, superposed trays. This plant consists of the generators _A_, the washer _B_, the equalising gasholder _C_, the purifier _D_, and the water-tank _E_. The carbide is arranged in baskets in the generators to which water is supplied from the cistern _E_ through the pipe _F_. The supply is controlled by means of the valve _H_, which is actuated through the rod _G_ by the rise and fall of the gasholder _C_. Gas travels from the gasholder through the purifier _D_ to the service-pipe. The purifier is packed with heratol resting on a layer of pumice. The washer _B_ contains a grid, the object of which is to distribute the stream of gas through the water. There is a syphon-pot _J_ for the reception of condensed moisture. Taps _K_ are provided for shutting off the supply of water from the generators during; recharging, and there is an overflow connexion _L_ for conveying the water to the second generator as soon as the first is exhausted. There is a sludge-cock _M_ at the base of each generator. (2) Non-automatic; water-to-carbide; contact, superposed trays. This resembles the preceding plant except that the supply of water from the cistern to the generators takes place directly through the pipe _N_ (shown in dotted lines in the diagram) and is controlled by hand through the taps _K_. The automatic control-valve _H_ and the rod _G_ are omitted. The gasholder _C_ is increased in size so that it becomes a storage holder capable of containing the whole of the gas evolved from one charging. [Illustration: FIG. 59.--GENERATING PLANT OF THE ST. JAMES' ILLUMINATING CO., LTD. (SECTIONAL ELEVATION AND PLAN.)] _Maker_: THE STANDARD ACETYLENE CO., 123 VICTORIA STREET, LONDON, S.W. _Type_: (1) Non-automatic; carbide-to-water. This plant comprises the generator _A_, the washer _B_, the storage gasholder _C_, and the purifier _D_. The generator is first filled with water to the crown of the cover, and carbide is then thrown into the water by hand through the gas-tight lock, which is opened and closed as required by the horizontal handle _P_. A cast-iron grid prevents the lumps of carbide falling into the sludge in the conical base of the generator. At the base of the cone is a sludge-valve _G_. The gas passes from the generator through the pipe _H_ into the washer _B_, and after bubbling through the water therein goes by way of the pipe _K_ into the gasholder _C_. The syphon- pot _E_ is provided for the reception of condensed moisture, which is removed from time to time by the pump _M_. From the gasholder the gas flows through the valve _R_ to the purifier _D_, whence it passes to the service-pipes. The purifier is charged with material supplied under the proprietary name of "Standard." [Illustration: FIG. 60.--CARBIDE-TO-WATER GENERATING PLANT OF THE STANDARD ACETYLENE CO.] (2) Automatic; water-to-carbide; contact, superposed trays. This plant comprises the generators _A_, the washer _B_, the equalising gasholder _C_, the purifier _D_, and the water-tank _E_. The carbide is arranged on a series of wire trays in each generator, to which water is supplied from the water-tank _E_ through the pipe _Y_ and the control-tap _U_. The gas passes through the pipes _H_ to the washer _B_ and thence to the holder _C_. The supply of water to the generators is controlled by the tap _U_ which is actuated by the rise and fall of the gasholder bell through the rod _F_. The gas passes, as in the non-automatic plant, through a purifier _D_ to the service-pipes. Taps _W_ are provided for cutting off the flow of water to either of the generators during recharging and an overflow pipe _h_ serves to convey the water to the second generator as soon as the carbide in the first is exhausted. A sludge-cook _G_ is put at the base of each generator. [Illustration: FIG. 61.--AUTOMATIC, WATER-TO-CARBIDE GENERATING PLANT OF THE STANDARD ACETYLENE CO.] (3) Non-automatic; water-to-carbide; contact, superposed-trays. This apparatus resembles the preceding except that the supply of water to the generators is controlled by hand through the taps _W_, the control valve _U_ being omitted, and the gasholder _C_ being a storage holder of sufficient dimensions to contain the whole of the acetylene evolved from one charging. _Maker_: THORN AND HODDLE ACETYLENE CO., 151 VICTORIA STREET, S.W. _Type_: Automatic; water-to-carbide; "drawer." The "Incanto" generating plant made by this firm consists of a rising bell gasholder which acts mainly on an equaliser. The fall of the bell depresses a ball valve immersed in the tank, and so allows water to flow from the tank past an outside tap, which is closed only during recharging, to a generating chamber. The generating chamber is horizontal and is fixed in the base of the tank, so that its outer case is surrounded by the water in the tank, with the object of keeping it cool. The charge of carbide is placed in a partitioned container, and is gradually attacked on the flooding principle by the water which enters from the gasholder tank when the ball valve is depressed. The gas evolved passes from the generating chamber by a pipe which extends above the level of the water in the tank, and is then bent down so that its end dips several inches below the level of the water. The gas issuing from the end of the pipe is thus washed by the water in the gasholder tank. From the gasholder the gas is taken off as required for use by a pipe, the mouth of which is just below the crown of the holder. There is a lip in the upper edge of the gasholder tank into which water is poured from time to time to replace that consumed in the generation of the gas. There are from one to three generating chambers in each apparatus according to its size. The purifier is independent, and a purifying mixture under the proprietary name of "Curazo" is supplied for use in it. [Illustration: FIG. 62.--"INCANTO" GENERATOR.] _Maker:_ WELDREN AND BLERIOT, 54 LONG ACRE, LONDON, W.C. _Type:_ Automatic; contact. This firm supplies the "Acétylithe" apparatus (_see_ Belgium). INDEX Absorbed acetylene, Acagine, Accidents, responsibility for, Acetone, effect of, on acetylene, solution of acetylene in, Acetylene-copper, Acetylene-oil-gas, Acetylene Association (Austrian)--regulations as to carbide, Acetylene Association (British)--analysis of carbide, generator rules, pressure gauges, purification rules, Acetylene Association (German)--analysis of carbide, holders, generator rules, standard carbide, Acetylene tetrachloride, production of, Ackermann burner, Advantages of acetylene, general, hygienic, intrinsic, pecuniary, "After generation," Air, admission of, to burners, and acetylene, ignition temperature of, composition of, dilution of acetylene with, before combustion, effect of acetylene lighting on, coal-gas lighting on, on illuminating power of acetylene, paraffin lighting on, in acetylene, in flames, effect of, in generators, danger of, objections to, in incandescent acetylene, in service-pipes, proportion of, rendering acetylene explosive, removing, from pipes, specific gravity of, sterilised by flames, Air-gas, and acetylene, comparison between, and carburetted acetylene, comparison between, effect of cold on, illuminating power of, Alcohol, action of, on carbide, for carburetting acetylene, holder seals, from acetylene, production of, Allgemeine Carbid und Acetylen Gesellschaft burner, Alloys, fusible, for testing generators, Alloys of copper. See _Copper (alloyed)_ Aluminium sulphide, in carbide America (U.S.), regulations of the National Board of Fire Underwriters, American gallon, value of, Ammonia, in acetylene, in coal-gas, removal of, solubility of, in water, Analysis of carbide, Ansdell, compressed and liquid acetylene, Anthracene, formation of, from acetylene, Anti-freezing agents, Area of purifiers, Argand burners, Aromatic hydrocarbons, Arrangement of generating plant, Arsenious oxide purifier, Atkins, dry process of generation, Atmospheric moisture and carbide, Atomic weights, Attention needed by generators, Austrian Acetylene Association, regulations as to carbide, Austrian Government Regulations, Autogenous soldering and welding, Automatic generators. See _Generators (automatic)_ B Baking of carbide Ball-sockets for acetylene, Barium peroxide purifier, sulphate in bleaching-powder, Barrel, gas, for acetylene, quality of Bell gasholders. See _Holders (rising)_ Benz purifying material, Benzene, for carburetting acetylene, production of, from acetylene, Benzine. See _Petroleum spirit_ Bergé, detection of phosphorus, and Reychler, purification of acetylene, and Reychler's reagent, solubility of acetylene in, Bernat, formula for mains and pipes, Berthelot, addition of chlorine to acetylene, sodium acetate, sulphuric acid and acetylene, Berthelot and Matignon, thermochemical data, and Vieille, dissolved acetylene, Billwiller burners, Black, acetylene, Blagden, sodium hypochlorite, Bleaching-powder purifier (simple), Blochmann, copper acetylide, Blow-off pipes. See _Vent-pipes_ Blowpipe, acetylene, Boiling-ring, Boistelle. See _Molet_ Borek, enrichment of oil-gas, _Bougie décimale_, Brackets for acetylene, Bradley, Read, and Jacobs, calcium carbophosphide, Brame and Lewes, manganese carbide, Bray burners, British Acetylene Association. See _Acetylene Association (British)_, Fire Offices Committee Regulations, regulations. See _Acetylene Association (British); Home Office; Orders in Council_ Bromine-water purifier, Bullier, effect of heat on burners, phosphorus in acetylene, and Maquenne purifier, Bunsen burner, principle of, Bunte, enrichment of oil-gas, Burner orifices and gas density, Burners, atmospheric, principle of, design of, glassware for, heating, incandescent, Ackermann, Allgemeine Carbid und Acetylen Gesellschaft, Bray, firing back in, Fouché, Günther's, illuminating power of, Jacob, Gebrüder, Keller and Knappich, Knappich, O.C.A., pressure for, principles of construction of, Schimek, Sirius, Trendel, typical, Weber, Zenith, self-luminous, Argand, as standard of light, Billwiller, Bray, choking of, corrosion of, cycle, Falk, Stadelmann and Co.'s, Konette, Phôs, Wiener's, Dolan, Drake, effect of heat on, Elta, Falk, Stadelmann and Co.'s, firing back in, fish-tail, Forbes, Hannam's, illuminating power of, self-luminous injector, Javal, Kona, Luta, Naphey, Orka, Phôs, Pintsch, pressure for, rat-tail, Sansair, Schwarz's, Stadelmann, Suprema, twin, angle of impingement in, injector, non-injector, warping of, Wiener's, Wonder, By-products, See also _Residues_ C Cadenel, shape of incandescent acetylene mantle, "Calcidum," Calcium carbide, action of heat on, action of non-aqueous liquids on, analysis of, and carbon bisulphide, reaction between, and hydroxide, reaction between, and ice, reaction between, and steam, reaction between, and water, reaction between, as drying material, baking of, balls and cartridges. See _Cartridges_ bulk of, chemical properties of, crushing of, decomposition of, by solids containing water, heat evolved during, imperfect, speed of, temperature attained during, deterioration of, on storage, drums of, dust in, explosibility of, fire, risk of, formula for, granulated, heat-conducting power of, of formation of, impurities in, inertness of, in residues, physical properties of, purity of, quality, regulations as to, sale and purchase of, regulations as to, scented, shape of lumps of, sizes of, small, yield of gas from, specific gravity of, heat of, standard, British, German, "sticks," storage regulations for, subdivided charges of, sundry uses of, swelling of, during decomposition, "treated," yield of acetylene from, Calcium carbophosphide, Calcium chloride, cause of frothing in generators, for seals, purifier, solubility of acetylene in, Calcium hydroxide, adhesion of, to carbide, and carbide, reaction between, milk of, solubility of acetylene in, physical properties of, space occupied by, Calcium hypochlorite, Calcium oxide, and water, reaction between, hydration of, hygroscopic nature of, physical properties of, Calcium phosphide, Calcium sulphide, Calorie, definition of, Calorific power of acetylene, various gases, Candle-power. See _Illuminating power_ Capelle, illuminating power of acetylene, Carbide. See _Calcium carbide_ Carbide-containers, air in, filling of, partitions in, water-jacketing, Carbide-feed generators. See _Generators (carbide-to-water)_ Carbide impurities in acetylene, Carbide-to-water generators. See _Generators (carbide-to-water)_ Carbides, mixed, Carbolic acid, production of, from acetylene, Carbon, combustion of, in flames, deposition of, in burners, gaseous, heat of combustion of, heat of combustion of, vaporisation of, pigment, production of, Carbon bisulphide and acetylene, reaction between, and calcium carbide, reaction between, in coal-gas, Carbon dioxide, addition of, to acetylene, dissociation of, effect of, on explosibility of acetylene, for removing air from pipes, heat of formation of, produced by respiration, benzene, coal-gas, in flame of acetylene, Carbon monoxide, in acetylene, heat of combustion of, formation of, temperature of ignition of, Carbonic acid. See _Carbon dioxide_ Carburetted acetylene, composition of, effect of cold on, illuminating power of, manufacture of, pecuniary value of, Carburetted water-gas, enrichment of, Carburine. See _Petroleum spirit_ Carlson, specific heat of carbide, Caro, acetone vapour in acetylene, addition of petroleum spirit to generator water, air in incandescent acetylene, calorific power of gases, colour of incandescent acetylene, composition of mantles, durability of mantles, heat production in generators, illuminating power of carburetted acetylene, of incandescent acetylene, oil of mustard, silicon in crude acetylene, Caro and Saulmann, "Calcidum," Carriage, cost of, and artificial lighting, Cartridges of carbide, Cast-iron pipe for acetylene, Castor oil for acetylene joints, Catani, temperature of acetylene flame, Caustic potash purifier, Cedercreutz, yield of gas from carbide, and Lunge, purification, Ceilings, blackening of, Ceria, proportion of, in mantles, Cesspools for residues, Chandeliers, hydraulic, for acetylene, Charcoal and chlorine purifier, Charging generators after dark, at irregular intervals, Chassiron lighthouse, Chemical formulæ, meaning of, Chemical reactions and heat, of acetylene, Chimneys for stoves, &c., glass, for burners, Chloride of lime. See _Bleaching-powder_ Chlorine and acetylene, compounds of, and charcoal purifier, in acetylene, Chromic acid purifier, Cigars, lighted, danger of, Claude and Hess, dissolved acetylene, Coal-gas, enrichment of, with acetylene, illuminating power of, impurities in, vitiation of air by, Cocks, hand-worked, in generators, Coefficient of expansion of acetone, air, dissolved acetylene, gaseous acetylene, liquid acetylene, simple gases, Coefficient of friction of acetylene, of coal-gas, Coke filters for acetylene, Cold, effect of, on acetylene, on air-gas, on carburetted acetylene, on generation, Colour judging by acetylene, of acetylene flame, of air-gas flame, Colour of atmospheric acetylene flame, of coal-gas flame, of electric light, of incandescent acetylene flame, of spent carbide, Combustion of acetylene, deposit from, Composition pipe for acetylene, Compounds, endo- and exo-thermic, explosive, of acetylene and copper, "Compounds," of phosphorus and sulphur, silicon, Compressed acetylene, Condensed matter in pipes, removal of, Condensers, Connexions, flexible, for acetylene, Construction of generators, principles of, regulations as to, Contact generators, Convection of heat, Cooking-stoves, Copper acetylide, (alloyed) in acetylene apparatus, (unalloyed) in acetylene apparatus, and acetylene, reactions between, carbides, chloride purifier Corrosion in apparatus, avoidance of, Corrosive sublimate purifier, as test for phosphorus Cost of acetylene lighting, Cotton-wool filters for acetylene, Council, Orders in. See _Orders in Council_ Counterpoises for rising holders, Couples, galvanic, Coward. See _Dixon_ Critical pressure and temperature of acetylene, Crushing of carbide, "Cuprene," Cuprous chloride purifier, Cycle lamps, burners for, dilute alcohol for, Cylinders for absorbed acetylene, D Davy, addition of chlorine to acetylene, Davy's lamp for generator sheds, Decomposing vessels. See _Carbide containers_ Decomposition of acetylene, of carbide, See _Calcium carbide (decomposition of)_ De Forcrand, heat of formation of carbide, Density. See _Specific gravity_ Deposit at burner orifices, on reflectors from combustion of acetylene, Deterioration of carbide in air, Diameter of pipes and explosive limits, Diaphragms, flexible, in generators, Diffusion through gasholder seals, Diluted acetylene, Dimensions of mains and pipes, Dipping generators, Displacement gasholders. See _Holders (displacement)_ Dissociation of acetylene, carbon dioxide, water vapour, Dissolution of acetylene, depression of freezing-point by, of gas in generators, Dissolved acetylene, Dixon and Coward, ignition temperature of acetylene, of various gases, Dolan burners, Doors of generator sheds, Drainage of mains, Drake burners, Driers, chemical, Dripping generators, Drums of carbide, Dry process of generation, Dufour, addition of air to acetylene, "Dummies" in gasholder tanks, Dust and incandescent lighting, in acetylene, carbide, E Effusion of gases, Eitner, explosive limits of acetylene, and Keppeler, estimation of phosphine, phosphorus in crude acetylene, Electric lamps in generator sheds, lighting, cost, and efficiency of, Elta burner, Endothermic compounds, nature of acetylene, Engines, use of acetylene in, Enrichment, value of acetylene for, with acetylene, épurène purifying material, Equations, chemical, meaning of, Erdmann, acetylene as a standard of light, colour of acetylene flame, production of alcohol, Ethylene, formation of from acetylene, heats of formation and combustion of, ignition temperature of, Exhaustion of air by flames, Exothermic compounds, Expansion of gaseous acetylene, coefficient of, of liquid acetylene coefficient of, various coefficients of, Explosibility of carbide, Explosion of chlorine and acetylene, of compressed acetylene, Explosive compounds of acetylene and copper, effects of acetylene dissociation, limits, meaning of term, of acetylene, of various gases, nature of acetylene, wave, speed of, in gases, Expulsion of air from mains, F Faced joints for acetylene, Falk, Stadelmann and Co., boiling-ring, burners, cycle-lamp burner, Ferric hydroxide purifier, Fery, temperature of flames, and Violle, acetylene as standard of light, Filters for acetylene, Filtration, Fire Offices Committee Regulations (British), risks of acetylene apparatus, carbide, flame illuminants, Underwriters, United States, Regulations, "Firing back" in incandescent burners, self-luminous burners, Fish, action of lime on, Fittings for acetylene, quality of, Flame, colour of, air-gas, atmospheric acetylene, coal-gas, incandescent, acetylene, self-luminous acetylene, Flame illuminants, risk of fire with, of acetylene containing air, steadiness of acetylene, Flame temperature of acetylene, temperature of various gases, Flames, distortion of, by solid matter, effect of air on, nitrogen on, evolution of heat in, light in, jumping of, liberation of carbon from, loss of heat from, shading of acetylene, size of, Flare lamps, Flash-point of paraffin, Flexible connexions for acetylene, Floats in holder seals, Flooded-compartment generators, Flow of gases in pipes, Flues for heating burners, Fog, transmission of light through, Forbes burner, Foreign regulations, Formulæ, meaning of chemical, Fouché, absorbed acetylene, burner, dissolved acetylene, illuminating power of acetylene air mixtures, incandescent acetylene, liquid acetylene, oxy-acetylene blowpipe, Fournier. See _Maneuvrier_ Fowler, enrichment of oil-gas, Fraenkel, deposit on reflectors from combustion of acetylene, silicon in acetylene, France, regulations of the Conseil d'Hygiène de la Seine, village acetylene mains in, Frank, freezing-point of calcium chloride solutions, preparation of black pigment, purifier, Frankoline, Freezing of generators, of holder seals, Freezing of portable lamps, of pressure-gauges, Freezing-point, depression of by dissolution of acetylene, of calcium chloride solutions, of dilute alcohol, of dilute glycerin, Freund and Mai, copper acetylide, Friction of acetylene, coefficient of, coal-gas, coefficient of, gas in pipes, Frost, effect of, on air-gas, on carburetted acetylene, Froth, lime, in acetylene, Frothing in generators, Fuchs and Schiff, olive oil, Furnace gases for removing air from pipes, G Gallon, American, value of, Galvanic action, Garelli and Falciola, depression of freezing-point by dissolution of acetylene, Gas barrel for acetylene, objection to, drying of, engines, acetylene for, escape of, from generators, firing, effects of, volumes, correction of, for temperature and pressure, yield of, from carbide, determining, standard, Gases, calorific value of, effusion of, explosive limits of, flame temperature of, illuminating power of, inflammable properties of, speed of explosive wave in, temperature of ignition of, Gasfitters' paint, Gasholders. See _Holders_ Gatehouse, F. B., test-papers, J. W., estimation of phosphine, Gaud, blocking of burners, polymerisation of acetylene, Generation, dry process of, Generating plant, regulations as to construction of, Generator impurities in acetylene, pressure, utilisation of, sheds, lighting of, smoking in, water, addition of bleaching-powder to, of petroleum spirit to, Generators and holders, isolation of, attention needed by, Generators, charging after dark, chemical reactions in, construction of, copper in, corrosion in, dissolution of gas in, effect of tarry matter in, escape of gas from, failure of, for analytical purposes, for welding, frothing in, frozen, thawing of, gauge of sheet-metal for, heat dissipation in, economy in, produced in, high temperatures and impurities in, instructions for using, joints in, making, "lagging" for, lead solder in, materials for construction of, maximum pressure in, output of gas from, overheating in, polymerisation in, pressure in, protection of, from frost, purchase of, regulations as to, American (National Board of Fire Underwriters), Austrian Government, British Acetylene Association, Fire Offices Committee, Home Office Committee(1901), French (Council d' Hygiene de la Seine), German Acetylene Association, Hungarian Government, Italian Government, responsibility for accidents with, selection of, temperatures in, typical, vent-pipes for, waste-pipes for, water-jackets for, water-scale in, Generators (automatic), advantages of, carbide-to-water, definition of, flexible diaphragms for, holders of, interlocking in, mechanism for, pressure thrown by, speed of reaction in, store of gas in, supply of water to, use of oil in, water-to-carbide, worked by holder bell, by pressure, Generators (carbide-to-water), advantages of, frothing of, grids for, loss of gas in, maximum temperature in, pressure in, quantity of water required by, Generators (contact), (dipping), temperatures in, (dripping), temperatures in, (flooded compartment), (non-automatic), advantages of, carbide-to-water, hand-charging of, water required for, definition of, speed of reaction in, water-to-carbide, (portable), (shoot), (water-to-carbide), overheating in, with carbide in excess, with water in excess, Gerard, silicon in crude acetylene, Gerdes, acetylene copper, German Acetylene Association. (See _Acetylene Association, German_) Gin, heat of formation of carbide, Glassware, for burners, Glow-lamps, electric, in generator sheds, Glucose for treatment of carbide, Glycerin for holder-seals, for wet meters, Governor, displacement holder as, Governors, Graham, effusion of gases, Gramme-molecules, Granjon, illuminating power of self-luminous burners, phosphine in acetylene, pressure, purifier, Granulated carbide. See _Calcium carbide, (granulated)_ Graphite, artificial, production of, Grease for treatment of carbide, Grids for carbide-to-water generators, in purifiers, Grittner, acetylene, and copper, Guides for rising holders, Güntner burner, H Haber, effect of heat on acetylene, Haldane, toxicity of sulphuretted hydrogen, Hammcrschmidt, correction of gas volumes, and Sandmann, milk of lime, Hannam's Ltd., burners, Hartmann, acetylene flame, Haze, on combustion of acetylene, Heat absorbed during change of physical state, action on acetylene. See _Overheating_ carbide, and temperature, difference between, conducting power of carbide iron and steel, water, convected, developed by acetylene lighting, coal-gas lighting, electric lighting, paraffin lighting, dissipation of, in generators, economy in generators, effect of, on acetylene. (See _Overheating_) on burners, evolution of, in flames, expansion of gaseous acetylene by, liquid acetylene by, from acetylene, production of, latent. See _Latent heat_ loss of, from flames, of chemical reactions, of combustion of acetylene, carbon, carbon monoxide, ethylene, of formation of acetylene, calcium carbide, hydroxide, oxide, carbon dioxide, monoxide, ethylene, water, of hydration of calcium oxide, of reaction between carbide and calcium hydroxide, between carbide and water, of solution of calcium hydroxide, of vaporisation of carbon, water, radiant, specific. See _Specific heat_ Heating apparatus for generator sheds, Hefner unit, Heil, atmospheric acetylene flame, carburetted acetylene, Heise, acetylene flame, Hempel, enrichment of coal-gas, Heratol, Hess. See _Claude_ Hexachlorethane, production of, High houses, supply of acetylene to, Holder-bells, for testing mains, supplying water to automatic generators, weighting of, Holder-seals, freezing of, level of liquid in, liquids in, and pressure, solubility of acetylene in, use of floats in, liquids in, for decomposing carbide, oil in, water in, for washing the gas, Holders (gas) and generators, isolation of, and pressure, relationship between, and purifiers, relative position of, exposed, roofs over, false interiors for, freezing of, gauge of sheet-metal for, loss of pressure in, moistening of gas in, of automatic generators, preservation of, from corrosion, situation of, size of, vent-pipes for, value of, Holders (displacement), action of, pressure given by, (rising), guides and counterpoises for, pressure thrown by, equalisation of, tanks for, Home Office, maximum pressure permitted by, prohibition of air in acetylene by, Committee, 1901, recommendations, report, Home Secretary's Orders. See _Orders in Council_ Hoxie. See _Stewart_, Hubou, acetylene black, Hungarian rules for apparatus, Hydraulic pendants for acetylene, Hydrocarbons formed by polymerisation, illuminating power of, volatile, names of, Hydrochloric acid in purified acetylene, Hydrogen and acetylene, reactions between, effect of, on acetylene flame, ignition temperature of, in acetylene, liberated by heat from acetylene, silicide in crude acetylene, Hygienic advantages of acetylene, I Ice, reaction between carbide and, Ignition temperature of acetylene, various gases, Illuminating power and illuminating effect, definition of, of acetylene, after storage, carburetted, effect of air on, incandescent, nominal, self-luminous, of acetylene-oil-gas, of air-gas, of polymerised acetylene, of candles, of coal-gas, of electric lamps, of hydrocarbons, various, of paraffin, Illumination, amount of, required in rooms, of lighthouses, of optical lanterns, Impurities in acetylene, carbide, detection and estimation of, effect of, on air, generator, harmfullness of, water soluble, See also _Ammonia_ and _Sulphuretted hydrogen_ in coal-gas, in purified acetylene, maximum limits of, Incandescent acetylene, burners. See _Burners (incandescent)_ mantles, Inertness of carbide, Inflaming-point of acetylene, Inflammability, spontaneous, Installations, new, removal of air from, Interlocking of automatic generators, Iron and acetylene, reactions between, and steel, heat-conducting power of, silicide in carbide, Insecticide, carbide residues as, Isolation of apparatus parts, Intensity, specific, of acetylene light, of oil light, Italian Government rules, J Jackets for generators, Jacob, Gebrüder, burner, Jacobs. See _Bradley_ Jaubert, arsenious oxide purifier, Javal burners, blocking of, purifier, Jet photometer of acetylene, Joint-making in generators, pipes, K Keller and Knappich burner, Keppeler, lead chromate in acagine, Keppeler, purification, silicon in acetylene, test-papers, See also _Eitner_ Kerosene. See _Paraffin oil_ Klinger, vent-pipes, Knappich burner, Kona burner, Konette cycle-lamp burner, L La Belle boiling ring, Labour required in acetylene lighting, Lagging for generators, Lamps for generator sheds paraffin, portable, acetone process for, Landolt-Börnstein, solubility of acetylene in water, Landriset. See _Rossel_ Lantern, optical, illumination of, Latent heat, Lead chromate in bleaching-powder, objection to, in generators, pipes for acetylene, salts in bleaching-powder, wire, &c., for faced joints, Leakage of acetylene, Leaks, search for, Le Chatelier, explosive limits, temperature of acetylene flame, thermo-couple Leduc, specific gravity of acetylene, Lépinay, acetylene for engines, Level alteration and pressure in mains, Lewes, ammonia in crude acetylene, blocking of burners, haze, heat of decomposition of carbide, production in generators, illuminating power of acetylene, phosphorus in crude acetylene, polymerisation of acetylene, presence of hydrogen and carbon monoxide in acetylene, reaction between carbide and calcium hydroxide, silicon in crude acetylene, temperature of acetylene flame, Lewes and Brame, manganese carbide, Lidholm, estimation of phosphine, Lifebuoys, acetylene for, Lifetime of burners, mantles, Lifting power of acetylene in holders, Light, acetylene as a standard of, colour of acetylene, incandescent, self-luminous, evolution of, in flames, from acetylene, production of, transmission of through fog, Lights, single, disadvantages of, strong and weak, comparison between, Lighthouse illumination, Lighting by acetylene, scope of, of generator sheds, Lime dust in acetylene, reaction with sodium carbonate, sludge. See _Residues_ solubility of, in sugar solutions, water, solubility of gas in, Lime-light, acetylene for the, Limits, explosive, of acetylene, Lindé-air, Linseed oil for acetylene joints, Liquid acetylene, properties of, condensation in pipes, in holder-seals and pressure, in pressure-gauge, Liquids, corrosive action of, on metals, for seals, purification by, solubility of acetylene in, Locomotive lighting, Loss of gas in generators, of pressure in holders, in mains, in purifiers, on distribution, Love, enrichment by acetylene, Lubricating oil for seals, Luminous burners. See _Burners, self-luminous_ Lunge and Cedercreutz, determination of phosphorus in acetylene, purification, Luta burner, Lutes for holders. See _Seals_ M Mahler, temperature of flames, Mai and Freund, copper acetylide, Mains, deposition of liquid in, diameter of, and explosive limits, dimensions of, escapes from, friction in, laying of, lead, quality of, removing air from, testing of, Make of acetylene from carbide, in generators, Manchester burners, Maneuvrier and Fournier, specific heat of acetylene, Manganese carbide, Mantles for acetylene, Manure for generator protection, Manurial value of generator residue, Maquenne. See _Bullier_ Marsh gas, enrichment with acetylene, formed from acetylene, Matignon. See _Berthelot_, Mauricheau-Beaupré, épurène, estimation of phosphine, frothing in generators, phosphine in acetylene, silicon in acetylene, Mechanism for automatic generators, Mercaptans in acetylene, Mercuric chloride purifier, test for phosphorus, Merck test-papers, Metals for generators, gauge of, Meters for acetylene, Methane, enrichment with acetylene, formed from acetylene, ignition temperature of, Methylated spirit for generators, for holder seals, Meyer and Münch, ignition temperatures, Mildew in vines, use of acetylene in, Milk of lime, solubility of acetylene in, Mineral oil for lighting. (See _Paraffin oil_) for seals, Miner's lamp for generator sheds, Mist, transmission of light through, Mixter, thermo-chemical data, Mixtures of acetylene and air, illuminating duty of, Moisture, effect of, on carbide, in acetylene, Molecular volume of acetylene, weight of acetylene, weights, various, Molet-Boistelle acetylene-air mixture, Morel, formula for acetylene pipes, sodium plumbate purifier, specific heat of acetylene, of carbide, Mosquitoes, destruction of, Moths, catching of, Motion of fluids in pipes, Motors, acetylene for, Münch. See _Meyer_ Münsterberg, acetylene flame, Mustard, oil of, N Naphey burners, Naphthalene, formation of, from acetylene, Neuberg, illuminating power of acetylene, radiant efficiency of acetylene, Nieuwland, mixtures of acetylene and chlorine, Nichols, illuminating power of acetylene after storage, temperature of acetylene flame, Nickel and acetylene, reactions between, Nipples, burner, materials for, Nitrides in carbide, Nitrogen in flames, effect of, Non-automatic generators. See _Generators (non-automatic)_ Non-luminous acetylene flame, appearance of, burners. See _Burners (atmospheric)_ Non-return valves, O O. C. A. burner, Odour of acetylene, Oil, action of, on carbide, castor, for acetylene joints, in generators, in residues, in seals, linseed, for acetylene joints, mustard, olive, for seals, (See also _Paraffin oil_) Olive oil for seals, Oil-gas, enrichment of, Optical efficiency of acetylene, Orders in Council, air in acetylene, compression of absorbed acetylene, acetylene-oil-gas, neat acetylene, Origin of petroleum, Orka burner, Ortloff, friction of acetylene, Overheating in generators, See also _Polymerisation_ Oxide of iron purifier, Oxy-acetylene blowpipe, Oxygen required for combustion of acetylene, of benzene, combustion of acetylene with, flames burning in, P Paint, cause of frothing in generators, gas-fitters', Paraffin oil, action of, on carbide, flash-point of, illuminating power of, in residues, lamps, lighting, effect of on air, heat developed by, quality of different grades of, use of in automatic generators, seals, Paraffin wax, treatment of carbide with, Partial pressure, Pendants, water-slide for acetylene, Petroleum oil. See _Paraffin oil_ spirit, addition of, to generator water, composition of, for carburetted acetylene, spirits, nomenclature of, theory of origin of, Pfeiffer, purifier, Pfleger, puratylene, Phenol, production of, from acetylene, Phôs burners, Phosphine, cause of deposit at burner orifices, composition of, in crude acetylene, amount of, toxicity of, Phosphoretted hydrogen. See _Phosphine_ Phosphorus and incandescent mantles, "compounds," in crude acetylene, in purified acetylene, detection and determination of, removal of, "Phossy-jaw," Photometer, jet of acetylene, Phylloxera, use of acetylene for, Physical properties of acetylene, Pickering, freezing-points of calcium chloride solutions, Pictet, freezing-points of dilute alcohol, purification of acetylene, Pintsch burners, Pipes, blow-off. See _Vent-pipes_ diameter of, and explosive limits, vent. See _Vent-pipes_ (See also _Mains_) Plant, acetylene, fire risks of, order of items in, Platinum in burners, Poisonous nature of acetylene, Pole, motion of fluids in pipes, pressure thrown by holders, Polymerisation, definition of, of acetylene, See also _Overheating_ Porous matter, absorption of acetylene in, Portable lamps, acetone process for, temperature in, Potassium bichromate purifier, hydroxide purifier, permanganate purifier, Power from acetylene, production of, Precautions with generators, with new installations, Presence of moisture in acetylene, Pressure and leakage, after explosions of acetylene, atmospheric, automatic generators working by, correction of gas volumes for, critical, of acetylene, definition of (gas), for incandescent burners, self-luminous burners, gauge, liquid for, given by displacement holders, rising holders, in generators, utilisation of, in mains and pipes, in purifiers, loss of, irregular, caused by vent-pipes, maximum safe, for acetylene, necessity for regular, partial, regulators. See _Governors_ Protection of generators from frost, holders from frost, Puratylene, Purchase of a generator, carbide, regulations as to, Purification by liquids and solids, in portable lamps, necessary extent of, reasons for, regulations as to, speed of, Purified acetylene, chlorine in, hydrochloric acid in, phosphorus in, sulphur in, Purifiers and holder, relative positions of, construction of, duplication of, exhaustion of, foul, emptying of, loss of pressure in, mechanical, for acetylene, Purifying materials, density of, efficiency of, quantity required, Pyralid, destruction of the, Q Quality of carbide, regulations as to, Quicklime. See _Calcium oxide_ R Radiant efficiency of acetylene, heat, Railway lighting by acetylene, Ramie mantles for acetylene, Range of explosibility, meaning of term, of acetylene, Rat-tail burner, Reactions between copper and acetylene, chemical, of acetylene, physical, of acetylene, Reaction grids in generators, Read and Jacobs. See _Bradley_ Rod lead for acetylene joints, Regulations, American (National Board of Fire Underwriters of U.S.A.), Austrian Acetylene Association, Government, British Acetylene Association, Fire Offices Committee, Home Office Committee (1901), for analysis of carbide, for construction of generating plant, for generators, for purification, for sale and purchase of carbide, for sampling carbide, for storing carbide, French (Conseil d'Hygiène de la Seine), German Acetylene Association, Hungarian Government, Italian Government, Residue from dry process of generation, Residues, carbide in, colour of, composition of, consistency of, disposal of, containing oil, manurial value of, utilisation of, Respiration of acetylene, Reversibility of reaction between calcium oxide and water, Reychler. See _Bergé_ Rising holders. See _Holders (rising)_ Rossel and Landriset, ammonia in crude acetylene, purifier, sulphur in crude acetylene, Roofs over exposed holders, Rooms, amount of illumination required in, Rubber tubes for acetylene, Ruby for burners, Rules. See _Regulations_ S Safety lamp, Davy's, for generator sheds, valves. See _Vent-pipes_ Sale of carbide, regulations as to, Salt, common, in holder-seals, Salzbergwerk Neu Stassfurt, production of tetrachlorethane, Sampling carbide, Sandmann. See _Hammerschmidt_ Sansair burner, Saulmann. See _Caro_ Sawdust in bleaching-powder, Scale, water, in generators, Scented carbide, Schiff. See _Fuchs_ Schimek burner, Schwander, carburetted acetylene, Schwarz burners, Seal-pots, Seals (holder). See _Holder-seals_ Seams in generator-making, Self-luminous burners. See _Burners (self-luminous)_ Sensible heat, Separation of holder from generator, Service-pipes. See _Mains_ Shoot generators, Silicon compounds, in acetylene, in carbide, Sirius burner, Slaked lime. See _Calcium hydroxide_ Sludge. See _Residues_ Sludge-cocks, automatic locking of, Sludge-pipes, blocked, clearance of, Smell of crude and purified acetylene, Smith, purification, Smoke, production of, by flames, Smoking, danger of, in generator sheds, Soap, use of, in testing pipes, Soda, washing, for decomposing carbide, Sodium acetate solution for generator jackets, Sodium carbonate and lime, reaction between, crystallised, for decomposing carbide, chloride for holder-seals, solubility of acetylene in, hypochlorite purifier, plumbate purifier, sulphate in bleaching-powder, Soil, carbide residues as dressing for, Solder in generators, Soldering, autogenous, Solids containing water, decomposition of carbide by, purification by, Solubility of acetylene, in generators, in holders, in liquids, Soot, production by, of flames, Space occupied by purifying materials, Sparks from steel tools, danger of, Specific gravity and holder pressure, leakage, of acetylene, dissolved, gaseous, liquid, of air, of carbide, of gases, and burner construction, of water, heat of acetylene, of carbide, heats, various, intensity. See _Intensity, specific_ Speed of reactions between carbide, water, and calcium hydroxide, of purification, Spent lime. See _Residues_ Spontaneous inflammability, Spraying apparatus, Stable manure for warming generators, Stadelmann burners, Standard of illumination in rooms, of light, acetylene as, Steam, latent heat of, use of, specific heat of, reaction between carbide and, Steam-barrel for acetylene mains, Steatite for burners, Steel, heat-conducting power of, tools, danger of Sterilisation of air by flames, Stewart and Hoxie, radiant efficiency of acetylene, Storage regulations for carbide, vessels for carbide, temporary, Styrolene. formation of, from acetylene, Suckert. See _Willson_ Suffocation by acetylene, Sugar solutions, solubility of lime in, Sulphur "compounds," in coal-gas, in crude acetylene, in purified acetylene, removal of, Sulphuretted hydrogen, solubility of, in water, toxicity of, Sulphuric acid and acetylene, reactions between as purifying material, Superficial area in purifiers, Supply of water to automatic generators, Suprenia burners, Swelling of carbide during decomposition, Symbols, chemical, meaning of, Syphons for removing water, T Table-lamps, acetone process for, Tabular numbers, Tanks for rising holders, construction of, "Tantalus Cup," Taps for acetylene pipes, Tar, cause of frothing in generators, Tarry matter in generators, Telescopic gasholders. _See Holder (rising)_ Temperature and heat, difference between, correction of volumes for, critical, of acetylene, high, effect of, on acetylene. See _Polymerization_ of acetylene blowpipe, flame, of dissociation of acetylene, of ignition of acetylene, various gases, of reaction between carbide and calcium hydroxide, between carbide and water, Temperatures in generators, calculation of, determination of, Tension of liquid acetylene, Test-papers, Tetrachlorethane, production of, Tetrachloride, acetylene, production of, Thawing of frozen apparatus, Thermo-chemical data, Thermo-couple, Le Chatelier's, Thomson, radiant efficiency of acetylene, thermo-chemical data, Tools, steel or iron, danger of, Town supplies, Toxicity of acetylene, of sulphur and phosphorus compounds, Train-lighting by acetylene, Treated carbide. See _Calcium carbide (treated)_ Trondol burner, Tubes, diameter of, and explosive limits, Tubes for acetylene. See _Mains_ Tubing, flexible, for acetylene, Typical generators, U Ullmax purifier, Unaccounted-for gas, Underwriters, United States Fire, United States. See _America_ Uses, sundry, for acetylene, V Valuation of carbide, Value of acetylene, hygienic, enriching, pecuniary, of purifying materials, Valves, screw-down, for generators, Vapour, water, in acetylene, objections to, removal of, value of, Vehicular lamps, Ventilation of generator sheds, Vent-pipes, economy of, for carbide vessels, generators, holders, noise in, position of mouths of, size of, Vibration and incandescent lighting, Vieille, dissolved acetylene, Vigouroux, silicon in acetylene, Village installations, mains for, leakage in, supplies, Villard, liquid acetylene, Vines, treatment by acetylene of, for mildew and phylloxera, Violle and Féry, acetylene as standard of light, Vitiation of air by flames, Volume, alteration of, on dissociation, and weight of acetylene, molecular, of acetylene, Volume of acetylene passing through pipes, Volumes, gas, correction for temperature and pressure, W Washers, oil, water, Waste-pipes of generators, Water and calcium oxide, reaction between, and carbide, heat of reaction between, boiling-point, evolution of gas at, condensation of, in pipes, consumption of, in generators, convection currents in, freezing-point, evolution of gas at, heat absorbed in warming, conducting power of, of formation of, in excess, generators with, in holders, freezing of, use for decomposition, use for washing, jackets for generators, quality of, for portable generators, quantity required in carbide-to-water generators, scale in generators, solubility of acetylene in, of impurities in, of load in, specific gravity of, supply for automatic generators, non-automatic generators, yield of gas per unit of, Water-gas, enrichment with acetylene, Water-seals, as not-return valves, setting water-level in, Water-slide pendants for acetylene, Water-soluble impurities in acetylene, See also _Ammonia and Sulphuretted hydrogen_ Water-to-carbide generators. See _Generators (water-to-carbide)_ Water-vapour, dissociation of, existence of, at low temperatures, in acetylene, objections to, removal of, value of, reaction between carbide and, Weber burner, Wedding, enrichment of coal-gas, Weed-killer, carbide residues as, Weight and volume of acetylene, Weights, atomic, molecular, Welding, acetylene, White lead, for acetylene joints, Wiener burners, Willgerodt, purification, Willson and Suckert, liquid acetylene, Windows in generator sheds, Winter, manipulation of generators during, Wöhler, addition of chlorine to acetylene, Wolff, acetone in acetylene, illuminating power of acetylene, purifier, silicon in acetylene, Wonder burner, Work done in actuating automatic generators, Y Yield of gas, deficient, cause of, from carbide, determining, (British standard), (German standard), from water, Z Zenith burner, INDEX TO APPENDIX A "A" Generator (of Braby and Co., Ltd.), "A1" generator (of Acetylene Corporation of Great Britain), "A-to-Z" generator (of Acetylene Corporation of Great Britain), Acetylene Corporation of Great Britain, Acetylene Gas and Carbide of Calcium Co., Acetylene Illuminating Co., Ltd., "Acetylite" generator, "Acétylithe" generator, Acétylithe, Soc. An. de l', Allen Co., "Allen" Flexible-tube generator, "Allen" purifying material, American generators, Applications de l'Acétylène, La Soc. des., Austrian generator, Automatic generators, B "B" generator (of Braby and Co., Ltd.), Belgian generators, Bon Accord Acetylene Gas Co., "Bon Accord" generator, Braby, Frederick and Co., Ltd., British generators, C Canadian generators, Carbide-to-water generators, "Carburlen" purifying material, Chloride of lime purifying material, Colt Co., J. G., "Colt" generator, Compartment, flooded, generator, Contact generators, Cork waste and wadding purifying material, "Corporation Flexible Tube Generator," "Curaze" purifying material, D "Dargue" generator, Dargue Acetylene Gas Co., Davis Acetylene Co., "Davis" generator, Debruyne, L., Debruyne's generators, Drawer generators, Drip generator, Drummond, J. and J., E English generators, F Flooded compartment generator, Fittings, Ltd., Frankoline purifying material, French generators, G German generators, H Heratol, purifying material, I "Incanto" generator, Irish generator, J "Javal" generator, K Keller and Knappich, G.m.b.H., "Klenzal" purifying material, Klinger, Rich., Klinger's generator, "Knappich" generator, L "L'Éclair" generator, "L'Étoile" generator, L'Hermite, Lockerbie and Wilkinson, M Manchester Acetylene Gas Col., Ltd., Mangiameli, Fr. and Co., Moss, R. J. and Sons, "Semi-Non-Auto" generator, "Type A" generator, "Type B" generator, "Type C" generator, Moyes Wm., and Sons, N Non-automatic generators, Nordische Azetylen Industrie, O "Omega" generator, Overberge, De Smet van, "Owens" generator, "Owens" purifying material, P Phôs Co., "Phôs Type E" generator, "Photolithe" generator, Photolithe, Soc. An. Belg de la, Pumice purifying material, Puratylene purifying material, Purifying material, "Allen," "Carburylen," chloride of lime, coke and cotton, chemically treated, cork waste and wadding, "Curaze," frankoline, heratol, "Klenzal," "Owens," pumice, puratylene, "Roscoline," "Standard," "Thorlite," R Rosco Acetylene Co., "Rosco" generator, "Roscoline" purifying material, Rural Districts Gas Light Co., S St. James' Illuminating Co., Ltd., Scotch generators, Semi-automatic generator, Siche Gas Co., Ltd., "Siche" generator, "Signal-Arm" generator, "Sirius" generator, Sirius, Maison, Standard Acetylene Co., "Standard" purifying material, Sunlight Gas Machine Co., Superposed pans or trays, T "Thorlite" generator, purifying material, Thorn and Hoddle Co., "Thorscar" generator, Trays, superposed, U United States generators, W Wadding and cork waste purifying material, Water-to-carbide generators, Weldhen and Bleriot, Welsh generator, "Westminster" generator,